text: /*
   * Copyright (c) 2008-2017 Nicira, Inc.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at:
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  #include <config.h>
  
  #include <sys/types.h>
  #include <netinet/in.h>
  
  #include "bundle.h"
  #include "byte-order.h"
  #include "colors.h"
  #include "compiler.h"
  #include "dummy.h"
  #include "openvswitch/hmap.h"
  #include "learn.h"
  #include "multipath.h"
  #include "nx-match.h"
  #include "odp-netlink.h"
  #include "openvswitch/dynamic-string.h"
  #include "openvswitch/meta-flow.h"
  #include "openvswitch/ofp-actions.h"
  #include "openvswitch/ofp-packet.h"
  #include "openvswitch/ofp-parse.h"
  #include "openvswitch/ofp-port.h"
  #include "openvswitch/ofp-prop.h"
  #include "openvswitch/ofp-table.h"
  #include "openvswitch/ofpbuf.h"
  #include "openvswitch/vlog.h"
  #include "unaligned.h"
  #include "util.h"
  #include "vl-mff-map.h"
  
  VLOG_DEFINE_THIS_MODULE(ofp_actions);
  
  static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
  
  struct ofp_action_header;
  
  /* Header for Open vSwitch and ONF vendor extension actions.
   *
   * This is the entire header for a few Open vSwitch vendor extension actions,
   * the ones that either have no arguments or for which variable-length
   * arguments follow the header.
   *
   * This cannot be used as an entirely generic vendor extension action header,
   * because OpenFlow does not specify the location or size of the action
   * subtype; it just happens that ONF extensions and Nicira extensions share
   * this format. */
  struct ext_action_header {
      ovs_be16 type;                  /* OFPAT_VENDOR. */
      ovs_be16 len;                   /* At least 16. */
      ovs_be32 vendor;                /* NX_VENDOR_ID or ONF_VENDOR_ID. */
      ovs_be16 subtype;               /* See enum ofp_raw_action_type. */
      uint8_t pad[6];
  };
  OFP_ASSERT(sizeof(struct ext_action_header) == 16);
  
  /* Raw identifiers for OpenFlow actions.
   *
   * Decoding and encoding OpenFlow actions across multiple versions is difficult
   * to do in a clean, consistent way.  This enumeration lays out all of the
   * forms of actions that Open vSwitch supports.
   *
   * The comments here must follow a stylized form because the
   * "extract-ofp-actions" program parses them at build time to generate data
   * tables.
   *
   *   - The first part of each comment specifies the vendor, OpenFlow versions,
   *     and type for each protocol that supports the action:
   *
   *         # The vendor is OF for standard OpenFlow actions, NX for Nicira
   *           extension actions.  (Support for other vendors can be added, but
   *           it can't be done just based on a vendor ID definition alone
   *           because OpenFlow doesn't define a standard way to specify a
   *           subtype for vendor actions, so other vendors might do it different
   *           from Nicira.)
   *
   *         # The version can specify a specific OpenFlow version, a version
   *           range delimited by "-", or an open-ended range with "+".
   *
   *         # The type, in parentheses, is the action type number (for standard
   *           OpenFlow actions) or subtype (for vendor extension actions).
   *
   *         # Optionally one may add "is deprecated" followed by a
   *           human-readable reason in parentheses (which will be used in log
   *           messages), if a particular action should no longer be used.
   *
   *     Multiple such specifications may be separated by commas.
   *
   *   - The second part describes the action's wire format.  It may be:
   *
   *         # "struct <name>": The struct fully specifies the wire format.  The
   *           action is exactly the size of the struct.  (Thus, the struct must
   *           be an exact multiple of 8 bytes in size.)
   *
   *         # "struct <name>, ...": The struct specifies the beginning of the
   *           wire format.  An instance of the action is either the struct's
   *           exact size, or a multiple of 8 bytes longer.
   *
   *         # "uint<N>_t" or "ovs_be<N>": The action consists of a (standard or
   *           vendor extension) header, followed by 0 or more pad bytes to align
   *           to a multiple of <N> bits, followed by an argument of the given
   *           type, followed by 0 or more pad bytes to bring the total action up
   *           to a multiple of 8 bytes.
   *
   *         # "void": The action is just a (standard or vendor extension)
   *           header.
   *
   *         # Optionally, one may add "VLMFF" in the end of the second part if
   *           the Openflow action may use a variable length meta-flow field
   *           (i.e. tun_metadata). Adding "VLMFF" will pass the per-switch based
   *           variable length meta-flow field mapping map (struct vl_mff_map) to
   *           the corresponding action decoding function.
   *
   *   - Optional additional text enclosed in square brackets is commentary for
   *     the human reader.
   */
  enum ofp_raw_action_type {
  /* ## ----------------- ## */
  /* ## Standard actions. ## */
  /* ## ----------------- ## */
  
      /* OF1.0(0): struct ofp10_action_output. */
      OFPAT_RAW10_OUTPUT,
      /* OF1.1+(0): struct ofp11_action_output. */
      OFPAT_RAW11_OUTPUT,
  
      /* OF1.0(1): uint16_t. */
      OFPAT_RAW10_SET_VLAN_VID,
      /* OF1.0(2): uint8_t. */
      OFPAT_RAW10_SET_VLAN_PCP,
  
      /* OF1.1(1), OF1.2+(1) is deprecated (use Set-Field): uint16_t.
       *
       * [Semantics differ slightly between the 1.0 and 1.1 versions of the VLAN
       * modification actions: the 1.0 versions push a VLAN header if none is
       * present, but the 1.1 versions do not.  That is the only reason that we
       * distinguish their raw action types.] */
      OFPAT_RAW11_SET_VLAN_VID,
      /* OF1.1(2), OF1.2+(2) is deprecated (use Set-Field): uint8_t. */
      OFPAT_RAW11_SET_VLAN_PCP,
  
      /* OF1.1+(17): ovs_be16.
       *
       * [The argument is the Ethertype, e.g. ETH_TYPE_VLAN_8021Q, not the VID or
       * TCI.] */
      OFPAT_RAW11_PUSH_VLAN,
  
      /* OF1.0(3): void. */
      OFPAT_RAW10_STRIP_VLAN,
      /* OF1.1+(18): void. */
      OFPAT_RAW11_POP_VLAN,
  
      /* OF1.0(4), OF1.1(3), OF1.2+(3) is deprecated (use Set-Field): struct
       * ofp_action_dl_addr. */
      OFPAT_RAW_SET_DL_SRC,
  
      /* OF1.0(5), OF1.1(4), OF1.2+(4) is deprecated (use Set-Field): struct
       * ofp_action_dl_addr. */
      OFPAT_RAW_SET_DL_DST,
  
      /* OF1.0(6), OF1.1(5), OF1.2+(5) is deprecated (use Set-Field):
       * ovs_be32. */
      OFPAT_RAW_SET_NW_SRC,
  
      /* OF1.0(7), OF1.1(6), OF1.2+(6) is deprecated (use Set-Field):
       * ovs_be32. */
      OFPAT_RAW_SET_NW_DST,
  
      /* OF1.0(8), OF1.1(7), OF1.2+(7) is deprecated (use Set-Field): uint8_t. */
      OFPAT_RAW_SET_NW_TOS,
  
      /* OF1.1(8), OF1.2+(8) is deprecated (use Set-Field): uint8_t. */
      OFPAT_RAW11_SET_NW_ECN,
  
      /* OF1.0(9), OF1.1(9), OF1.2+(9) is deprecated (use Set-Field):
       * ovs_be16. */
      OFPAT_RAW_SET_TP_SRC,
  
      /* OF1.0(10), OF1.1(10), OF1.2+(10) is deprecated (use Set-Field):
       * ovs_be16. */
      OFPAT_RAW_SET_TP_DST,
  
      /* OF1.0(11): struct ofp10_action_enqueue. */
      OFPAT_RAW10_ENQUEUE,
  
      /* NX1.0(30), OF1.1(13), OF1.2+(13) is deprecated (use Set-Field):
       * ovs_be32. */
      OFPAT_RAW_SET_MPLS_LABEL,
  
      /* NX1.0(31), OF1.1(14), OF1.2+(14) is deprecated (use Set-Field):
       * uint8_t. */
      OFPAT_RAW_SET_MPLS_TC,
  
      /* NX1.0(25), OF1.1(15), OF1.2+(15) is deprecated (use Set-Field):
       * uint8_t. */
      OFPAT_RAW_SET_MPLS_TTL,
  
      /* NX1.0(26), OF1.1+(16): void. */
      OFPAT_RAW_DEC_MPLS_TTL,
  
      /* NX1.0(23), OF1.1+(19): ovs_be16.
       *
       * [The argument is the Ethertype, e.g. ETH_TYPE_MPLS, not the label.] */
      OFPAT_RAW_PUSH_MPLS,
  
      /* NX1.0(24), OF1.1+(20): ovs_be16.
       *
       * [The argument is the Ethertype, e.g. ETH_TYPE_IPV4 if at BoS or
       * ETH_TYPE_MPLS otherwise, not the label.] */
      OFPAT_RAW_POP_MPLS,
  
      /* NX1.0(4), OF1.1+(21): uint32_t. */
      OFPAT_RAW_SET_QUEUE,
  
      /* NX1.0(40), OF1.1+(22): uint32_t. */
      OFPAT_RAW_GROUP,
  
      /* OF1.1+(23): uint8_t. */
      OFPAT_RAW11_SET_NW_TTL,
  
      /* NX1.0(18), OF1.1+(24): void. */
      OFPAT_RAW_DEC_NW_TTL,
      /* NX1.0+(21): struct nx_action_cnt_ids, ... */
      NXAST_RAW_DEC_TTL_CNT_IDS,
  
      /* OF1.2-1.4(25): struct ofp12_action_set_field, ... VLMFF */
      OFPAT_RAW12_SET_FIELD,
      /* OF1.5+(25): struct ofp12_action_set_field, ... VLMFF */
      OFPAT_RAW15_SET_FIELD,
      /* NX1.0-1.4(7): struct nx_action_reg_load. VLMFF
       *
       * [In OpenFlow 1.5, set_field is a superset of reg_load functionality, so
       * we drop reg_load.] */
      NXAST_RAW_REG_LOAD,
      /* NX1.0-1.4(33): struct ext_action_header, ... VLMFF
       *
       * [In OpenFlow 1.5, set_field is a superset of reg_load2 functionality, so
       * we drop reg_load2.] */
      NXAST_RAW_REG_LOAD2,
  
      /* OF1.5+(28): struct ofp15_action_copy_field, ... VLMFF */
      OFPAT_RAW15_COPY_FIELD,
      /* ONF1.3-1.4(3200): struct onf_action_copy_field, ... VLMFF */
      ONFACT_RAW13_COPY_FIELD,
      /* NX1.0-1.4(6): struct nx_action_reg_move, ... VLMFF */
      NXAST_RAW_REG_MOVE,
  
  /* ## ------------------------- ## */
  /* ## Nicira extension actions. ## */
  /* ## ------------------------- ## */
  
  /* Actions similar to standard actions are listed with the standard actions. */
  
      /* NX1.0+(1): uint16_t. */
      NXAST_RAW_RESUBMIT,
      /* NX1.0+(14): struct nx_action_resubmit. */
      NXAST_RAW_RESUBMIT_TABLE,
      /* NX1.0+(44): struct nx_action_resubmit. */
      NXAST_RAW_RESUBMIT_TABLE_CT,
  
      /* NX1.0+(2): uint32_t. */
      NXAST_RAW_SET_TUNNEL,
      /* NX1.0+(9): uint64_t. */
      NXAST_RAW_SET_TUNNEL64,
  
      /* NX1.0+(5): void. */
      NXAST_RAW_POP_QUEUE,
  
      /* NX1.0+(8): struct nx_action_note, ... */
      NXAST_RAW_NOTE,
  
      /* NX1.0+(10): struct nx_action_multipath. VLMFF */
      NXAST_RAW_MULTIPATH,
  
      /* NX1.0+(12): struct nx_action_bundle, ... */
      NXAST_RAW_BUNDLE,
      /* NX1.0+(13): struct nx_action_bundle, ... VLMFF */
      NXAST_RAW_BUNDLE_LOAD,
  
      /* NX1.0+(15): struct nx_action_output_reg. VLMFF */
      NXAST_RAW_OUTPUT_REG,
      /* NX1.0+(32): struct nx_action_output_reg2. VLMFF */
      NXAST_RAW_OUTPUT_REG2,
  
      /* NX1.0+(16): struct nx_action_learn, ... VLMFF */
      NXAST_RAW_LEARN,
      /* NX1.0+(45): struct nx_action_learn2, ... VLMFF */
      NXAST_RAW_LEARN2,
  
      /* NX1.0+(17): void. */
      NXAST_RAW_EXIT,
  
      /* NX1.0+(19): struct nx_action_fin_timeout. */
      NXAST_RAW_FIN_TIMEOUT,
  
      /* NX1.0+(20): struct nx_action_controller. */
      NXAST_RAW_CONTROLLER,
      /* NX1.0+(37): struct ext_action_header, ... */
      NXAST_RAW_CONTROLLER2,
  
      /* NX1.0+(22): struct nx_action_write_metadata. */
      NXAST_RAW_WRITE_METADATA,
  
      /* NX1.0+(27): struct nx_action_stack. VLMFF */
      NXAST_RAW_STACK_PUSH,
  
      /* NX1.0+(28): struct nx_action_stack. VLMFF */
      NXAST_RAW_STACK_POP,
  
      /* NX1.0+(29): struct nx_action_sample. */
      NXAST_RAW_SAMPLE,
      /* NX1.0+(38): struct nx_action_sample2. */
      NXAST_RAW_SAMPLE2,
      /* NX1.0+(41): struct nx_action_sample2. */
      NXAST_RAW_SAMPLE3,
  
      /* NX1.0+(34): struct nx_action_conjunction. */
      NXAST_RAW_CONJUNCTION,
  
      /* NX1.0+(35): struct nx_action_conntrack, ... VLMFF */
      NXAST_RAW_CT,
  
      /* NX1.0+(36): struct nx_action_nat, ... */
      NXAST_RAW_NAT,
  
      /* NX1.0+(39): struct nx_action_output_trunc. */
      NXAST_RAW_OUTPUT_TRUNC,
  
      /* NX1.0+(42): struct ext_action_header, ... VLMFF */
      NXAST_RAW_CLONE,
  
      /* NX1.0+(43): void. */
      NXAST_RAW_CT_CLEAR,
  
      /* NX1.3+(46): struct nx_action_encap, ... */
      NXAST_RAW_ENCAP,
  
      /* NX1.3+(47): struct nx_action_decap, ... */
      NXAST_RAW_DECAP,
  
      /* NX1.3+(48): void. */
      NXAST_RAW_DEC_NSH_TTL,
  
  /* ## ------------------ ## */
  /* ## Debugging actions. ## */
  /* ## ------------------ ## */
  
  /* These are intentionally undocumented, subject to change, and ovs-vswitchd */
  /* accepts them only if started with --enable-dummy. */
  
      /* NX1.0+(254): void. */
      NXAST_RAW_DEBUG_SLOW,
  
      /* NX1.0+(255): void. */
      NXAST_RAW_DEBUG_RECIRC,
  };
  
  /* OpenFlow actions are always a multiple of 8 bytes in length. */
  #define OFP_ACTION_ALIGN 8
  
  /* Define a few functions for working with instructions. */
  #define DEFINE_INST(ENUM, STRUCT, EXTENSIBLE, NAME)             \
      static inline const struct STRUCT * OVS_UNUSED              \
      instruction_get_##ENUM(const struct ofp11_instruction *inst)\
      {                                                           \
          ovs_assert(inst->type == htons(ENUM));                  \
          return ALIGNED_CAST(struct STRUCT *, inst);             \
      }                                                           \
                                                                  \
      static inline void OVS_UNUSED                               \
      instruction_init_##ENUM(struct STRUCT *s)                   \
      {                                                           \
          memset(s, 0, sizeof *s);                                \
          s->type = htons(ENUM);                                  \
          s->len = htons(sizeof *s);                              \
      }                                                           \
                                                                  \
      static inline struct STRUCT * OVS_UNUSED                    \
      instruction_put_##ENUM(struct ofpbuf *buf)                  \
      {                                                           \
          struct STRUCT *s = ofpbuf_put_uninit(buf, sizeof *s);   \
          instruction_init_##ENUM(s);                             \
          return s;                                               \
      }
  OVS_INSTRUCTIONS
  #undef DEFINE_INST
  
  static void ofpacts_update_instruction_actions(struct ofpbuf *openflow,
                                                 size_t ofs);
  static void pad_ofpat(struct ofpbuf *openflow, size_t start_ofs);
  
  static enum ofperr ofpacts_verify(const struct ofpact[], size_t ofpacts_len,
                                    uint32_t allowed_ovsinsts,
                                    enum ofpact_type outer_action);
  
  static void put_set_field(struct ofpbuf *openflow, enum ofp_version,
                            enum mf_field_id, uint64_t value);
  
  static void put_reg_load(struct ofpbuf *openflow,
                           const struct mf_subfield *, uint64_t value);
  
  static enum ofperr ofpact_pull_raw(struct ofpbuf *, enum ofp_version,
                                     enum ofp_raw_action_type *, uint64_t *arg);
  static void *ofpact_put_raw(struct ofpbuf *, enum ofp_version,
                              enum ofp_raw_action_type, uint64_t arg);
  
  static char *OVS_WARN_UNUSED_RESULT ofpacts_parse(
      char *str, const struct ofpact_parse_params *pp,
      bool allow_instructions, enum ofpact_type outer_action);
  static enum ofperr ofpacts_pull_openflow_actions__(
      struct ofpbuf *openflow, unsigned int actions_len,
      enum ofp_version version, uint32_t allowed_ovsinsts,
      struct ofpbuf *ofpacts, enum ofpact_type outer_action,
      const struct vl_mff_map *vl_mff_map, uint64_t *ofpacts_tlv_bitmap);
  static char * OVS_WARN_UNUSED_RESULT ofpacts_parse_copy(
      const char *s_, const struct ofpact_parse_params *pp,
      bool allow_instructions, enum ofpact_type outer_action);
  
  static void inconsistent_match(enum ofputil_protocol *usable_protocols);
  
  /* Returns the ofpact following 'ofpact', except that if 'ofpact' contains
   * nested ofpacts it returns the first one. */
  struct ofpact *
  ofpact_next_flattened(const struct ofpact *ofpact)
  {
      switch (ofpact->type) {
      case OFPACT_OUTPUT:
      case OFPACT_GROUP:
      case OFPACT_CONTROLLER:
      case OFPACT_ENQUEUE:
      case OFPACT_OUTPUT_REG:
      case OFPACT_OUTPUT_TRUNC:
      case OFPACT_BUNDLE:
      case OFPACT_SET_FIELD:
      case OFPACT_SET_VLAN_VID:
      case OFPACT_SET_VLAN_PCP:
      case OFPACT_STRIP_VLAN:
      case OFPACT_PUSH_VLAN:
      case OFPACT_SET_ETH_SRC:
      case OFPACT_SET_ETH_DST:
      case OFPACT_SET_IPV4_SRC:
      case OFPACT_SET_IPV4_DST:
      case OFPACT_SET_IP_DSCP:
      case OFPACT_SET_IP_ECN:
      case OFPACT_SET_IP_TTL:
      case OFPACT_SET_L4_SRC_PORT:
      case OFPACT_SET_L4_DST_PORT:
      case OFPACT_REG_MOVE:
      case OFPACT_STACK_PUSH:
      case OFPACT_STACK_POP:
      case OFPACT_DEC_TTL:
      case OFPACT_SET_MPLS_LABEL:
      case OFPACT_SET_MPLS_TC:
      case OFPACT_SET_MPLS_TTL:
      case OFPACT_DEC_MPLS_TTL:
      case OFPACT_PUSH_MPLS:
      case OFPACT_POP_MPLS:
      case OFPACT_SET_TUNNEL:
      case OFPACT_SET_QUEUE:
      case OFPACT_POP_QUEUE:
      case OFPACT_FIN_TIMEOUT:
      case OFPACT_RESUBMIT:
      case OFPACT_LEARN:
      case OFPACT_CONJUNCTION:
      case OFPACT_MULTIPATH:
      case OFPACT_NOTE:
      case OFPACT_EXIT:
      case OFPACT_SAMPLE:
      case OFPACT_UNROLL_XLATE:
      case OFPACT_CT_CLEAR:
      case OFPACT_DEBUG_RECIRC:
      case OFPACT_DEBUG_SLOW:
      case OFPACT_METER:
      case OFPACT_CLEAR_ACTIONS:
      case OFPACT_WRITE_METADATA:
      case OFPACT_GOTO_TABLE:
      case OFPACT_NAT:
      case OFPACT_ENCAP:
      case OFPACT_DECAP:
      case OFPACT_DEC_NSH_TTL:
          return ofpact_next(ofpact);
  
      case OFPACT_CLONE:
          return ofpact_get_CLONE(ofpact)->actions;
  
      case OFPACT_CT:
          return ofpact_get_CT(ofpact)->actions;
  
      case OFPACT_WRITE_ACTIONS:
          return ofpact_get_WRITE_ACTIONS(ofpact)->actions;
      }
  
      OVS_NOT_REACHED();
  }
  
  /* Pull off existing actions or instructions. Used by nesting actions to keep
   * ofpacts_parse() oblivious of actions nesting.
   *
   * Push the actions back on after nested parsing, e.g.:
   *
   *     size_t ofs = ofpacts_pull(ofpacts);
   *     ...nested parsing...
   *     ofpbuf_push_uninit(ofpacts, ofs);
   */
  static size_t
  ofpacts_pull(struct ofpbuf *ofpacts)
  {
      size_t ofs;
  
      ofs = ofpacts->size;
      ofpbuf_pull(ofpacts, ofs);
  
      return ofs;
  }
  
  #include "ofp-actions.inc1"
  
  /* Output actions. */
  
  /* Action structure for OFPAT10_OUTPUT, which sends packets out 'port'.
   * When the 'port' is the OFPP_CONTROLLER, 'max_len' indicates the max
   * number of bytes to send.  A 'max_len' of zero means no bytes of the
   * packet should be sent. */
  struct ofp10_action_output {
      ovs_be16 type;                  /* OFPAT10_OUTPUT. */
      ovs_be16 len;                   /* Length is 8. */
      ovs_be16 port;                  /* Output port. */
      ovs_be16 max_len;               /* Max length to send to controller. */
  };
  OFP_ASSERT(sizeof(struct ofp10_action_output) == 8);
  
  /* Action structure for OFPAT_OUTPUT, which sends packets out 'port'.
     * When the 'port' is the OFPP_CONTROLLER, 'max_len' indicates the max
     * number of bytes to send. A 'max_len' of zero means no bytes of the
     * packet should be sent.*/
  struct ofp11_action_output {
      ovs_be16 type;                    /* OFPAT11_OUTPUT. */
      ovs_be16 len;                     /* Length is 16. */
      ovs_be32 port;                    /* Output port. */
      ovs_be16 max_len;                 /* Max length to send to controller. */
      uint8_t pad[6];                   /* Pad to 64 bits. */
  };
  OFP_ASSERT(sizeof(struct ofp11_action_output) == 16);
  
  static enum ofperr
  decode_OFPAT_RAW10_OUTPUT(const struct ofp10_action_output *oao,
                            enum ofp_version ofp_version OVS_UNUSED,
                            struct ofpbuf *out)
  {
      struct ofpact_output *output;
  
      output = ofpact_put_OUTPUT(out);
      output->port = u16_to_ofp(ntohs(oao->port));
      output->max_len = ntohs(oao->max_len);
  
      return ofpact_check_output_port(output->port, OFPP_MAX);
  }
  
  static enum ofperr
  decode_OFPAT_RAW11_OUTPUT(const struct ofp11_action_output *oao,
                            enum ofp_version ofp_version OVS_UNUSED,
                            struct ofpbuf *out)
  {
      struct ofpact_output *output;
      enum ofperr error;
  
      output = ofpact_put_OUTPUT(out);
      output->max_len = ntohs(oao->max_len);
  
      error = ofputil_port_from_ofp11(oao->port, &output->port);
      if (error) {
          return error;
      }
  
      return ofpact_check_output_port(output->port, OFPP_MAX);
  }
  
  static void
  encode_OUTPUT(const struct ofpact_output *output,
                enum ofp_version ofp_version, struct ofpbuf *out)
  {
      if (ofp_version == OFP10_VERSION) {
          struct ofp10_action_output *oao;
  
          oao = put_OFPAT10_OUTPUT(out);
          oao->port = htons(ofp_to_u16(output->port));
          oao->max_len = htons(output->max_len);
      } else {
          struct ofp11_action_output *oao;
  
          oao = put_OFPAT11_OUTPUT(out);
          oao->port = ofputil_port_to_ofp11(output->port);
          oao->max_len = htons(output->max_len);
      }
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_truncate_subfield(const char *arg_,
                          const struct ofpact_parse_params *pp,
                          struct ofpact_output_trunc *output_trunc)
  {
      char *key, *value;
      char *arg = CONST_CAST(char *, arg_);
  
      while (ofputil_parse_key_value(&arg, &key, &value)) {
          if (!strcmp(key, "port")) {
              if (!ofputil_port_from_string(value, pp->port_map,
                                            &output_trunc->port)) {
                  return xasprintf("output to unknown truncate port: %s",
                                    value);
              }
              if (ofp_to_u16(output_trunc->port) > ofp_to_u16(OFPP_MAX)) {
                  if (output_trunc->port != OFPP_LOCAL &&
                      output_trunc->port != OFPP_IN_PORT)
                  return xasprintf("output to unsupported truncate port: %s",
                                   value);
              }
          } else if (!strcmp(key, "max_len")) {
              char *err;
  
              err = str_to_u32(value, &output_trunc->max_len);
              if (err) {
                  return err;
              }
          } else {
              return xasprintf("invalid key '%s' in output_trunc argument",
                                  key);
          }
      }
      return NULL;
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_OUTPUT(const char *arg, const struct ofpact_parse_params *pp)
  {
      if (strstr(arg, "port") && strstr(arg, "max_len")) {
          struct ofpact_output_trunc *output_trunc;
  
          output_trunc = ofpact_put_OUTPUT_TRUNC(pp->ofpacts);
          return parse_truncate_subfield(arg, pp, output_trunc);
      }
  
      ofp_port_t port;
      if (ofputil_port_from_string(arg, pp->port_map, &port)) {
          struct ofpact_output *output = ofpact_put_OUTPUT(pp->ofpacts);
          output->port = port;
          output->max_len = output->port == OFPP_CONTROLLER ? UINT16_MAX : 0;
          return NULL;
      }
  
      struct mf_subfield src;
      char *error = mf_parse_subfield(&src, arg);
      if (!error) {
          struct ofpact_output_reg *output_reg;
  
          output_reg = ofpact_put_OUTPUT_REG(pp->ofpacts);
          output_reg->max_len = UINT16_MAX;
          output_reg->src = src;
          return NULL;
      }
      free(error);
  
      return xasprintf("%s: output to unknown port", arg);
  }
  
  static void
  format_OUTPUT(const struct ofpact_output *a,
                const struct ofpact_format_params *fp)
  {
      if (ofp_to_u16(a->port) < ofp_to_u16(OFPP_MAX)) {
          ds_put_format(fp->s, "%soutput:%s", colors.special, colors.end);
      }
      ofputil_format_port(a->port, fp->port_map, fp->s);
      if (a->port == OFPP_CONTROLLER) {
          ds_put_format(fp->s, ":%"PRIu16, a->max_len);
      }
  }
  
  static enum ofperr
  check_OUTPUT(const struct ofpact_output *a,
               const struct ofpact_check_params *cp)
  {
      return ofpact_check_output_port(a->port, cp->max_ports);
  }
  
  /* Group actions. */
  
  static enum ofperr
  decode_OFPAT_RAW_GROUP(uint32_t group_id,
                           enum ofp_version ofp_version OVS_UNUSED,
                           struct ofpbuf *out)
  {
      ofpact_put_GROUP(out)->group_id = group_id;
      return 0;
  }
  
  static void
  encode_GROUP(const struct ofpact_group *group,
               enum ofp_version ofp_version, struct ofpbuf *out)
  {
      put_OFPAT_GROUP(out, ofp_version, group->group_id);
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_GROUP(char *arg, const struct ofpact_parse_params *pp)
  {
      return str_to_u32(arg, &ofpact_put_GROUP(pp->ofpacts)->group_id);
  }
  
  static void
  format_GROUP(const struct ofpact_group *a,
               const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%sgroup:%s%"PRIu32,
                    colors.special, colors.end, a->group_id);
  }
  
  static enum ofperr
  check_GROUP(const struct ofpact_group *a OVS_UNUSED,
              const struct ofpact_check_params *cp OVS_UNUSED)
  {
      return 0;
  }
  
  /* Action structure for NXAST_CONTROLLER.
   *
   * This generalizes using OFPAT_OUTPUT to send a packet to OFPP_CONTROLLER.  In
   * addition to the 'max_len' that OFPAT_OUTPUT supports, it also allows
   * specifying:
   *
   *    - 'reason': The reason code to use in the ofp_packet_in or nx_packet_in.
   *
   *    - 'controller_id': The ID of the controller connection to which the
   *      ofp_packet_in should be sent.  The ofp_packet_in or nx_packet_in is
   *      sent only to controllers that have the specified controller connection
   *      ID.  See "struct nx_controller_id" for more information. */
  struct nx_action_controller {
      ovs_be16 type;                  /* OFPAT_VENDOR. */
      ovs_be16 len;                   /* Length is 16. */
      ovs_be32 vendor;                /* NX_VENDOR_ID. */
      ovs_be16 subtype;               /* NXAST_CONTROLLER. */
      ovs_be16 max_len;               /* Maximum length to send to controller. */
      ovs_be16 controller_id;         /* Controller ID to send packet-in. */
      uint8_t reason;                 /* enum ofp_packet_in_reason (OFPR_*). */
      uint8_t zero;                   /* Must be zero. */
  };
  OFP_ASSERT(sizeof(struct nx_action_controller) == 16);
  
  /* Properties for NXAST_CONTROLLER2.
   *
   * For more information on the effect of NXAC2PT_PAUSE, see the large comment
   * on NXT_PACKET_IN2 in nicira-ext.h */
  enum nx_action_controller2_prop_type {
      NXAC2PT_MAX_LEN,            /* ovs_be16 max bytes to send (default all). */
      NXAC2PT_CONTROLLER_ID,      /* ovs_be16 dest controller ID (default 0). */
      NXAC2PT_REASON,             /* uint8_t reason (OFPR_*), default 0. */
      NXAC2PT_USERDATA,           /* Data to copy into NXPINT_USERDATA. */
      NXAC2PT_PAUSE,              /* Flag to pause pipeline to resume later. */
      NXAC2PT_METER_ID,           /* ovs_b32 meter (default NX_CTLR_NO_METER). */
  };
  
  /* The action structure for NXAST_CONTROLLER2 is "struct ext_action_header",
   * followed by NXAC2PT_* properties. */
  
  static enum ofperr
  decode_NXAST_RAW_CONTROLLER(const struct nx_action_controller *nac,
                              enum ofp_version ofp_version OVS_UNUSED,
                              struct ofpbuf *out)
  {
      struct ofpact_controller *oc;
  
      oc = ofpact_put_CONTROLLER(out);
      oc->ofpact.raw = NXAST_RAW_CONTROLLER;
      oc->max_len = ntohs(nac->max_len);
      oc->controller_id = ntohs(nac->controller_id);
      oc->reason = nac->reason;
      oc->meter_id = NX_CTLR_NO_METER;
      ofpact_finish_CONTROLLER(out, &oc);
  
      return 0;
  }
  
  static enum ofperr
  decode_NXAST_RAW_CONTROLLER2(const struct ext_action_header *eah,
                               enum ofp_version ofp_version OVS_UNUSED,
                               struct ofpbuf *out)
  {
      if (!is_all_zeros(eah->pad, sizeof eah->pad)) {
          return OFPERR_NXBRC_MUST_BE_ZERO;
      }
  
      size_t start_ofs = out->size;
      struct ofpact_controller *oc = ofpact_put_CONTROLLER(out);
      oc->ofpact.raw = NXAST_RAW_CONTROLLER2;
      oc->max_len = UINT16_MAX;
      oc->reason = OFPR_ACTION;
      oc->meter_id = NX_CTLR_NO_METER;
  
      struct ofpbuf properties;
      ofpbuf_use_const(&properties, eah, ntohs(eah->len));
      ofpbuf_pull(&properties, sizeof *eah);
  
      while (properties.size > 0) {
          struct ofpbuf payload;
          uint64_t type;
  
          enum ofperr error = ofpprop_pull(&properties, &payload, &type);
          if (error) {
              return error;
          }
  
          switch (type) {
          case NXAC2PT_MAX_LEN:
              error = ofpprop_parse_u16(&payload, &oc->max_len);
              break;
  
          case NXAC2PT_CONTROLLER_ID:
              error = ofpprop_parse_u16(&payload, &oc->controller_id);
              break;
  
          case NXAC2PT_REASON: {
              uint8_t u8;
              error = ofpprop_parse_u8(&payload, &u8);
              oc->reason = u8;
              break;
          }
  
          case NXAC2PT_USERDATA:
              out->size = start_ofs + OFPACT_CONTROLLER_SIZE;
              ofpbuf_put(out, payload.msg, ofpbuf_msgsize(&payload));
              oc = ofpbuf_at_assert(out, start_ofs, sizeof *oc);
              oc->userdata_len = ofpbuf_msgsize(&payload);
              break;
  
          case NXAC2PT_PAUSE:
              oc->pause = true;
              break;
  
          case NXAC2PT_METER_ID:
              error = ofpprop_parse_u32(&payload, &oc->meter_id);
              break;
  
          default:
              error = OFPPROP_UNKNOWN(false, "NXAST_RAW_CONTROLLER2", type);
              break;
          }
          if (error) {
              return error;
          }
      }
  
      ofpact_finish_CONTROLLER(out, &oc);
  
      return 0;
  }
  
  static void
  encode_CONTROLLER(const struct ofpact_controller *controller,
                    enum ofp_version ofp_version OVS_UNUSED,
                    struct ofpbuf *out)
  {
      if (controller->userdata_len
          || controller->pause
          || controller->meter_id != NX_CTLR_NO_METER
          || controller->ofpact.raw == NXAST_RAW_CONTROLLER2) {
          size_t start_ofs = out->size;
          put_NXAST_CONTROLLER2(out);
          if (controller->max_len != UINT16_MAX) {
              ofpprop_put_u16(out, NXAC2PT_MAX_LEN, controller->max_len);
          }
          if (controller->controller_id != 0) {
              ofpprop_put_u16(out, NXAC2PT_CONTROLLER_ID,
                              controller->controller_id);
          }
          if (controller->reason != OFPR_ACTION) {
              ofpprop_put_u8(out, NXAC2PT_REASON, controller->reason);
          }
          if (controller->userdata_len != 0) {
              ofpprop_put(out, NXAC2PT_USERDATA, controller->userdata,
                          controller->userdata_len);
          }
          if (controller->pause) {
              ofpprop_put_flag(out, NXAC2PT_PAUSE);
          }
          if (controller->meter_id != NX_CTLR_NO_METER) {
              ofpprop_put_u32(out, NXAC2PT_METER_ID, controller->meter_id);
          }
          pad_ofpat(out, start_ofs);
      } else {
          struct nx_action_controller *nac;
  
          nac = put_NXAST_CONTROLLER(out);
          nac->max_len = htons(controller->max_len);
          nac->controller_id = htons(controller->controller_id);
          nac->reason = controller->reason;
      }
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_CONTROLLER(char *arg, const struct ofpact_parse_params *pp)
  {
      enum ofp_packet_in_reason reason = OFPR_ACTION;
      uint16_t controller_id = 0;
      uint16_t max_len = UINT16_MAX;
      uint32_t meter_id = NX_CTLR_NO_METER;
      const char *userdata = NULL;
      bool pause = false;
  
      if (!arg[0]) {
          /* Use defaults. */
      } else if (strspn(arg, "0123456789") == strlen(arg)) {
          char *error = str_to_u16(arg, "max_len", &max_len);
          if (error) {
              return error;
          }
      } else {
          char *name, *value;
  
          while (ofputil_parse_key_value(&arg, &name, &value)) {
              if (!strcmp(name, "reason")) {
                  if (!ofputil_packet_in_reason_from_string(value, &reason)) {
                      return xasprintf("unknown reason \"%s\"", value);
                  }
              } else if (!strcmp(name, "max_len")) {
                  char *error = str_to_u16(value, "max_len", &max_len);
                  if (error) {
                      return error;
                  }
              } else if (!strcmp(name, "id")) {
                  char *error = str_to_u16(value, "id", &controller_id);
                  if (error) {
                      return error;
                  }
              } else if (!strcmp(name, "userdata")) {
                  userdata = value;
              } else if (!strcmp(name, "pause")) {
                  pause = true;
              } else if (!strcmp(name, "meter_id")) {
                  char *error = str_to_u32(value, &meter_id);
                  if (error) {
                      return error;
                  }
              } else {
                  return xasprintf("unknown key \"%s\" parsing controller "
                                   "action", name);
              }
          }
      }
  
      if (reason == OFPR_ACTION && controller_id == 0 && !userdata && !pause
          && meter_id == NX_CTLR_NO_METER) {
          struct ofpact_output *output;
  
          output = ofpact_put_OUTPUT(pp->ofpacts);
          output->port = OFPP_CONTROLLER;
          output->max_len = max_len;
      } else {
          struct ofpact_controller *controller;
  
          controller = ofpact_put_CONTROLLER(pp->ofpacts);
          controller->max_len = max_len;
          controller->reason = reason;
          controller->controller_id = controller_id;
          controller->pause = pause;
          controller->meter_id = meter_id;
  
          if (userdata) {
              size_t start_ofs = pp->ofpacts->size;
              const char *end = ofpbuf_put_hex(pp->ofpacts, userdata, NULL);
              if (*end) {
                  return xstrdup("bad hex digit in `controller' "
                                 "action `userdata'");
              }
              size_t userdata_len = pp->ofpacts->size - start_ofs;
              controller = pp->ofpacts->header;
              controller->userdata_len = userdata_len;
          }
          ofpact_finish_CONTROLLER(pp->ofpacts, &controller);
      }
  
      return NULL;
  }
  
  static void
  format_hex_arg(struct ds *s, const uint8_t *data, size_t len)
  {
      for (size_t i = 0; i < len; i++) {
          if (i) {
              ds_put_char(s, '.');
          }
          ds_put_format(s, "%02"PRIx8, data[i]);
      }
  }
  
  static void
  format_CONTROLLER(const struct ofpact_controller *a,
                    const struct ofpact_format_params *fp)
  {
      if (a->reason == OFPR_ACTION && !a->controller_id && !a->userdata_len
          && !a->pause && a->meter_id == NX_CTLR_NO_METER) {
          ds_put_format(fp->s, "%sCONTROLLER:%s%"PRIu16,
                        colors.special, colors.end, a->max_len);
      } else {
          enum ofp_packet_in_reason reason = a->reason;
  
          ds_put_format(fp->s, "%scontroller(%s", colors.paren, colors.end);
          if (reason != OFPR_ACTION) {
              char reasonbuf[OFPUTIL_PACKET_IN_REASON_BUFSIZE];
  
              ds_put_format(fp->s, "%sreason=%s%s,", colors.param, colors.end,
                            ofputil_packet_in_reason_to_string(
                                reason, reasonbuf, sizeof reasonbuf));
          }
          if (a->max_len != UINT16_MAX) {
              ds_put_format(fp->s, "%smax_len=%s%"PRIu16",",
                            colors.param, colors.end, a->max_len);
          }
          if (a->controller_id != 0) {
              ds_put_format(fp->s, "%sid=%s%"PRIu16",",
                            colors.param, colors.end, a->controller_id);
          }
          if (a->userdata_len) {
              ds_put_format(fp->s, "%suserdata=%s", colors.param, colors.end);
              format_hex_arg(fp->s, a->userdata, a->userdata_len);
              ds_put_char(fp->s, ',');
          }
          if (a->pause) {
              ds_put_format(fp->s, "%spause%s,", colors.value, colors.end);
          }
          if (a->meter_id != NX_CTLR_NO_METER) {
              ds_put_format(fp->s, "%smeter_id=%s%"PRIu32",",
                            colors.param, colors.end, a->meter_id);
          }
          ds_chomp(fp->s, ',');
          ds_put_format(fp->s, "%s)%s", colors.paren, colors.end);
      }
  }
  
  static enum ofperr
  check_CONTROLLER(const struct ofpact_controller *a OVS_UNUSED,
                   const struct ofpact_check_params *cp OVS_UNUSED)
  {
      return 0;
  }
  
  /* Enqueue action. */
  struct ofp10_action_enqueue {
      ovs_be16 type;            /* OFPAT10_ENQUEUE. */
      ovs_be16 len;             /* Len is 16. */
      ovs_be16 port;            /* Port that queue belongs. Should
                                   refer to a valid physical port
                                   (i.e. < OFPP_MAX) or OFPP_IN_PORT. */
      uint8_t pad[6];           /* Pad for 64-bit alignment. */
      ovs_be32 queue_id;        /* Where to enqueue the packets. */
  };
  OFP_ASSERT(sizeof(struct ofp10_action_enqueue) == 16);
  
  static enum ofperr
  decode_OFPAT_RAW10_ENQUEUE(const struct ofp10_action_enqueue *oae,
                             enum ofp_version ofp_version OVS_UNUSED,
                             struct ofpbuf *out)
  {
      struct ofpact_enqueue *enqueue;
  
      enqueue = ofpact_put_ENQUEUE(out);
      enqueue->port = u16_to_ofp(ntohs(oae->port));
      enqueue->queue = ntohl(oae->queue_id);
      if (ofp_to_u16(enqueue->port) >= ofp_to_u16(OFPP_MAX)
          && enqueue->port != OFPP_IN_PORT
          && enqueue->port != OFPP_LOCAL) {
          return OFPERR_OFPBAC_BAD_OUT_PORT;
      }
      return 0;
  }
  
  static void
  encode_ENQUEUE(const struct ofpact_enqueue *enqueue,
                 enum ofp_version ofp_version, struct ofpbuf *out)
  {
      if (ofp_version == OFP10_VERSION) {
          struct ofp10_action_enqueue *oae;
  
          oae = put_OFPAT10_ENQUEUE(out);
          oae->port = htons(ofp_to_u16(enqueue->port));
          oae->queue_id = htonl(enqueue->queue);
      } else {
          put_OFPAT_SET_QUEUE(out, ofp_version, enqueue->queue);
  
          struct ofp11_action_output *oao = put_OFPAT11_OUTPUT(out);
          oao->port = ofputil_port_to_ofp11(enqueue->port);
          oao->max_len = OVS_BE16_MAX;
  
          put_NXAST_POP_QUEUE(out);
      }
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_ENQUEUE(char *arg, const struct ofpact_parse_params *pp)
  {
      char *sp = NULL;
      char *port = strtok_r(arg, ":q,", &sp);
      char *queue = strtok_r(NULL, "", &sp);
      struct ofpact_enqueue *enqueue;
  
      if (port == NULL || queue == NULL) {
          return xstrdup("\"enqueue\" syntax is \"enqueue:PORT:QUEUE\" or "
                         "\"enqueue(PORT,QUEUE)\"");
      }
  
      enqueue = ofpact_put_ENQUEUE(pp->ofpacts);
      if (!ofputil_port_from_string(port, pp->port_map, &enqueue->port)) {
          return xasprintf("%s: enqueue to unknown port", port);
      }
      return str_to_u32(queue, &enqueue->queue);
  }
  
  static void
  format_ENQUEUE(const struct ofpact_enqueue *a,
                 const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%senqueue:%s", colors.param, colors.end);
      ofputil_format_port(a->port, fp->port_map, fp->s);
      ds_put_format(fp->s, ":%"PRIu32, a->queue);
  }
  
  static enum ofperr
  check_ENQUEUE(const struct ofpact_enqueue *a,
                const struct ofpact_check_params *cp)
  {
      if (ofp_to_u16(a->port) >= ofp_to_u16(cp->max_ports)
          && a->port != OFPP_IN_PORT
          && a->port != OFPP_LOCAL) {
          return OFPERR_OFPBAC_BAD_OUT_PORT;
      }
      return 0;
  }
  
  /* Action structure for NXAST_OUTPUT_REG.
   *
   * Outputs to the OpenFlow port number written to src[ofs:ofs+nbits].
   *
   * The format and semantics of 'src' and 'ofs_nbits' are similar to those for
   * the NXAST_REG_LOAD action.
   *
   * The acceptable nxm_header values for 'src' are the same as the acceptable
   * nxm_header values for the 'src' field of NXAST_REG_MOVE.
   *
   * The 'max_len' field indicates the number of bytes to send when the chosen
   * port is OFPP_CONTROLLER.  Its semantics are equivalent to the 'max_len'
   * field of OFPAT_OUTPUT.
   *
   * The 'zero' field is required to be zeroed for forward compatibility. */
  struct nx_action_output_reg {
      ovs_be16 type;              /* OFPAT_VENDOR. */
      ovs_be16 len;               /* 24. */
      ovs_be32 vendor;            /* NX_VENDOR_ID. */
      ovs_be16 subtype;           /* NXAST_OUTPUT_REG. */
  
      ovs_be16 ofs_nbits;         /* (ofs << 6) | (n_bits - 1). */
      ovs_be32 src;               /* Source. */
  
      ovs_be16 max_len;           /* Max length to send to controller. */
  
      uint8_t zero[6];            /* Reserved, must be zero. */
  };
  OFP_ASSERT(sizeof(struct nx_action_output_reg) == 24);
  
  /* Action structure for NXAST_OUTPUT_REG2.
   *
   * Like the NXAST_OUTPUT_REG but organized so that there is room for a 64-bit
   * experimenter OXM as 'src'.
   */
  struct nx_action_output_reg2 {
      ovs_be16 type;              /* OFPAT_VENDOR. */
      ovs_be16 len;               /* 24. */
      ovs_be32 vendor;            /* NX_VENDOR_ID. */
      ovs_be16 subtype;           /* NXAST_OUTPUT_REG2. */
  
      ovs_be16 ofs_nbits;         /* (ofs << 6) | (n_bits - 1). */
      ovs_be16 max_len;           /* Max length to send to controller. */
  
      /* Followed by:
       * - 'src', as an OXM/NXM header (either 4 or 8 bytes).
       * - Enough 0-bytes to pad the action out to 24 bytes. */
      uint8_t pad[10];
  };
  OFP_ASSERT(sizeof(struct nx_action_output_reg2) == 24);
  
  static enum ofperr
  decode_NXAST_RAW_OUTPUT_REG(const struct nx_action_output_reg *naor,
                              enum ofp_version ofp_version OVS_UNUSED,
                              const struct vl_mff_map *vl_mff_map,
                              uint64_t *tlv_bitmap, struct ofpbuf *out)
  {
      struct ofpact_output_reg *output_reg;
      enum ofperr error;
  
      if (!is_all_zeros(naor->zero, sizeof naor->zero)) {
          return OFPERR_OFPBAC_BAD_ARGUMENT;
      }
  
      output_reg = ofpact_put_OUTPUT_REG(out);
      output_reg->ofpact.raw = NXAST_RAW_OUTPUT_REG;
      output_reg->src.ofs = nxm_decode_ofs(naor->ofs_nbits);
      output_reg->src.n_bits = nxm_decode_n_bits(naor->ofs_nbits);
      output_reg->max_len = ntohs(naor->max_len);
      error = mf_vl_mff_mf_from_nxm_header(ntohl(naor->src), vl_mff_map,
                                           &output_reg->src.field, tlv_bitmap);
      if (error) {
          return error;
      }
  
      return mf_check_src(&output_reg->src, NULL);
  }
  
  static enum ofperr
  decode_NXAST_RAW_OUTPUT_REG2(const struct nx_action_output_reg2 *naor,
                               enum ofp_version ofp_version OVS_UNUSED,
                               const struct vl_mff_map *vl_mff_map,
                               uint64_t *tlv_bitmap, struct ofpbuf *out)
  {
      struct ofpact_output_reg *output_reg;
      enum ofperr error;
  
      output_reg = ofpact_put_OUTPUT_REG(out);
      output_reg->ofpact.raw = NXAST_RAW_OUTPUT_REG2;
      output_reg->src.ofs = nxm_decode_ofs(naor->ofs_nbits);
      output_reg->src.n_bits = nxm_decode_n_bits(naor->ofs_nbits);
      output_reg->max_len = ntohs(naor->max_len);
  
      struct ofpbuf b = ofpbuf_const_initializer(naor, ntohs(naor->len));
      ofpbuf_pull(&b, OBJECT_OFFSETOF(naor, pad));
  
      error = mf_vl_mff_nx_pull_header(&b, vl_mff_map, &output_reg->src.field,
                                       NULL, tlv_bitmap);
      if (error) {
          return error;
      }
  
      if (!is_all_zeros(b.data, b.size)) {
          return OFPERR_NXBRC_MUST_BE_ZERO;
      }
  
      return mf_check_src(&output_reg->src, NULL);
  }
  
  static void
  encode_OUTPUT_REG(const struct ofpact_output_reg *output_reg,
                    enum ofp_version ofp_version OVS_UNUSED,
                    struct ofpbuf *out)
  {
      /* If 'output_reg' came in as an NXAST_RAW_OUTPUT_REG2 action, or if it
       * cannot be encoded in the older form, encode it as
       * NXAST_RAW_OUTPUT_REG2. */
      if (output_reg->ofpact.raw == NXAST_RAW_OUTPUT_REG2
          || !mf_nxm_header(output_reg->src.field->id)) {
          struct nx_action_output_reg2 *naor = put_NXAST_OUTPUT_REG2(out);
          size_t size = out->size;
  
          naor->ofs_nbits = nxm_encode_ofs_nbits(output_reg->src.ofs,
                                                 output_reg->src.n_bits);
          naor->max_len = htons(output_reg->max_len);
  
          out->size = size - sizeof naor->pad;
          nx_put_mff_header(out, output_reg->src.field, 0, false);
          out->size = size;
      } else {
          struct nx_action_output_reg *naor = put_NXAST_OUTPUT_REG(out);
  
          naor->ofs_nbits = nxm_encode_ofs_nbits(output_reg->src.ofs,
                                                 output_reg->src.n_bits);
          naor->src = htonl(nxm_header_from_mff(output_reg->src.field));
          naor->max_len = htons(output_reg->max_len);
      }
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_OUTPUT_REG(const char *arg, const struct ofpact_parse_params *pp)
  {
      return parse_OUTPUT(arg, pp);
  }
  
  static void
  format_OUTPUT_REG(const struct ofpact_output_reg *a,
                    const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%soutput:%s", colors.special, colors.end);
      mf_format_subfield(&a->src, fp->s);
  }
  
  static enum ofperr
  check_OUTPUT_REG(const struct ofpact_output_reg *a,
                   const struct ofpact_check_params *cp)
  {
      return mf_check_src(&a->src, cp->match);
  }
  
  /* Action structure for NXAST_BUNDLE and NXAST_BUNDLE_LOAD.
   *
   * The bundle actions choose a slave from a supplied list of options.
   * NXAST_BUNDLE outputs to its selection.  NXAST_BUNDLE_LOAD writes its
   * selection to a register.
   *
   * The list of possible slaves follows the nx_action_bundle structure. The size
   * of each slave is governed by its type as indicated by the 'slave_type'
   * parameter. The list of slaves should be padded at its end with zeros to make
   * the total length of the action a multiple of 8.
   *
   * Switches infer from the 'slave_type' parameter the size of each slave.  All
   * implementations must support the NXM_OF_IN_PORT 'slave_type' which indicates
   * that the slaves are OpenFlow port numbers with NXM_LENGTH(NXM_OF_IN_PORT) ==
   * 2 byte width.  Switches should reject actions which indicate unknown or
   * unsupported slave types.
   *
   * Switches use a strategy dictated by the 'algorithm' parameter to choose a
   * slave.  If the switch does not support the specified 'algorithm' parameter,
   * it should reject the action.
   *
   * Several algorithms take into account liveness when selecting slaves.  The
   * liveness of a slave is implementation defined (with one exception), but will
   * generally take into account things like its carrier status and the results
   * of any link monitoring protocols which happen to be running on it.  In order
   * to give controllers a place-holder value, the OFPP_NONE port is always
   * considered live, that is, NXAST_BUNDLE_LOAD stores OFPP_NONE in the output
   * register if no slave is live.
   *
   * Some slave selection strategies require the use of a hash function, in which
   * case the 'fields' and 'basis' parameters should be populated.  The 'fields'
   * parameter (one of NX_HASH_FIELDS_*) designates which parts of the flow to
   * hash.  Refer to the definition of "enum nx_hash_fields" for details.  The
   * 'basis' parameter is used as a universal hash parameter.  Different values
   * of 'basis' yield different hash results.
   *
   * The 'zero' parameter at the end of the action structure is reserved for
   * future use.  Switches are required to reject actions which have nonzero
   * bytes in the 'zero' field.
   *
   * NXAST_BUNDLE actions should have 'ofs_nbits' and 'dst' zeroed.  Switches
   * should reject actions which have nonzero bytes in either of these fields.
   *
   * NXAST_BUNDLE_LOAD stores the OpenFlow port number of the selected slave in
   * dst[ofs:ofs+n_bits].  The format and semantics of 'dst' and 'ofs_nbits' are
   * similar to those for the NXAST_REG_LOAD action. */
  struct nx_action_bundle {
      ovs_be16 type;              /* OFPAT_VENDOR. */
      ovs_be16 len;               /* Length including slaves. */
      ovs_be32 vendor;            /* NX_VENDOR_ID. */
      ovs_be16 subtype;           /* NXAST_BUNDLE or NXAST_BUNDLE_LOAD. */
  
      /* Slave choice algorithm to apply to hash value. */
      ovs_be16 algorithm;         /* One of NX_BD_ALG_*. */
  
      /* What fields to hash and how. */
      ovs_be16 fields;            /* One of NX_HASH_FIELDS_*. */
      ovs_be16 basis;             /* Universal hash parameter. */
  
      ovs_be32 slave_type;        /* NXM_OF_IN_PORT. */
      ovs_be16 n_slaves;          /* Number of slaves. */
  
      ovs_be16 ofs_nbits;         /* (ofs << 6) | (n_bits - 1). */
      ovs_be32 dst;               /* Destination. */
  
      uint8_t zero[4];            /* Reserved. Must be zero. */
  };
  OFP_ASSERT(sizeof(struct nx_action_bundle) == 32);
  
  static enum ofperr
  decode_bundle(bool load, const struct nx_action_bundle *nab,
                const struct vl_mff_map *vl_mff_map, uint64_t *tlv_bitmap,
                struct ofpbuf *ofpacts)
  {
      static struct vlog_rate_limit rll = VLOG_RATE_LIMIT_INIT(1, 5);
      struct ofpact_bundle *bundle;
      uint32_t slave_type;
      size_t slaves_size, i;
      enum ofperr error;
  
      bundle = ofpact_put_BUNDLE(ofpacts);
  
      bundle->n_slaves = ntohs(nab->n_slaves);
      bundle->basis = ntohs(nab->basis);
      bundle->fields = ntohs(nab->fields);
      bundle->algorithm = ntohs(nab->algorithm);
      slave_type = ntohl(nab->slave_type);
      slaves_size = ntohs(nab->len) - sizeof *nab;
  
      error = OFPERR_OFPBAC_BAD_ARGUMENT;
      if (!flow_hash_fields_valid(bundle->fields)) {
          VLOG_WARN_RL(&rll, "unsupported fields %d", (int) bundle->fields);
      } else if (bundle->n_slaves > BUNDLE_MAX_SLAVES) {
          VLOG_WARN_RL(&rll, "too many slaves");
      } else if (bundle->algorithm != NX_BD_ALG_HRW
                 && bundle->algorithm != NX_BD_ALG_ACTIVE_BACKUP) {
          VLOG_WARN_RL(&rll, "unsupported algorithm %d", (int) bundle->algorithm);
      } else if (slave_type != mf_nxm_header(MFF_IN_PORT)) {
          VLOG_WARN_RL(&rll, "unsupported slave type %"PRIu32, slave_type);
      } else {
          error = 0;
      }
  
      if (!is_all_zeros(nab->zero, sizeof nab->zero)) {
          VLOG_WARN_RL(&rll, "reserved field is nonzero");
          error = OFPERR_OFPBAC_BAD_ARGUMENT;
      }
  
      if (load) {
          bundle->dst.ofs = nxm_decode_ofs(nab->ofs_nbits);
          bundle->dst.n_bits = nxm_decode_n_bits(nab->ofs_nbits);
          error = mf_vl_mff_mf_from_nxm_header(ntohl(nab->dst), vl_mff_map,
                                               &bundle->dst.field, tlv_bitmap);
          if (error) {
              return error;
          }
  
          if (bundle->dst.n_bits < 16) {
              VLOG_WARN_RL(&rll, "bundle_load action requires at least 16 bit "
                           "destination.");
              error = OFPERR_OFPBAC_BAD_ARGUMENT;
          }
      } else {
          if (nab->ofs_nbits || nab->dst) {
              VLOG_WARN_RL(&rll, "bundle action has nonzero reserved fields");
              error = OFPERR_OFPBAC_BAD_ARGUMENT;
          }
      }
  
      if (slaves_size < bundle->n_slaves * sizeof(ovs_be16)) {
          VLOG_WARN_RL(&rll, "Nicira action %s only has %"PRIuSIZE" bytes "
                       "allocated for slaves.  %"PRIuSIZE" bytes are required "
                       "for %u slaves.",
                       load ? "bundle_load" : "bundle", slaves_size,
                       bundle->n_slaves * sizeof(ovs_be16), bundle->n_slaves);
          error = OFPERR_OFPBAC_BAD_LEN;
      } else {
          for (i = 0; i < bundle->n_slaves; i++) {
              ofp_port_t ofp_port
                  = u16_to_ofp(ntohs(((ovs_be16 *)(nab + 1))[i]));
              ofpbuf_put(ofpacts, &ofp_port, sizeof ofp_port);
              bundle = ofpacts->header;
          }
      }
  
      ofpact_finish_BUNDLE(ofpacts, &bundle);
      if (!error) {
          error = bundle_check(bundle, OFPP_MAX, NULL);
      }
      return error;
  }
  
  static enum ofperr
  decode_NXAST_RAW_BUNDLE(const struct nx_action_bundle *nab,
                          enum ofp_version ofp_version OVS_UNUSED,
                          struct ofpbuf *out)
  {
      return decode_bundle(false, nab, NULL, NULL, out);
  }
  
  static enum ofperr
  decode_NXAST_RAW_BUNDLE_LOAD(const struct nx_action_bundle *nab,
                               enum ofp_version ofp_version OVS_UNUSED,
                               const struct vl_mff_map *vl_mff_map,
                               uint64_t *tlv_bitmap, struct ofpbuf *out)
  {
      return decode_bundle(true, nab, vl_mff_map, tlv_bitmap, out);
  }
  
  static void
  encode_BUNDLE(const struct ofpact_bundle *bundle,
                enum ofp_version ofp_version OVS_UNUSED,
                struct ofpbuf *out)
  {
      int slaves_len = ROUND_UP(2 * bundle->n_slaves, OFP_ACTION_ALIGN);
      struct nx_action_bundle *nab;
      ovs_be16 *slaves;
      size_t i;
  
      nab = (bundle->dst.field
             ? put_NXAST_BUNDLE_LOAD(out)
             : put_NXAST_BUNDLE(out));
      nab->len = htons(ntohs(nab->len) + slaves_len);
      nab->algorithm = htons(bundle->algorithm);
      nab->fields = htons(bundle->fields);
      nab->basis = htons(bundle->basis);
      nab->slave_type = htonl(mf_nxm_header(MFF_IN_PORT));
      nab->n_slaves = htons(bundle->n_slaves);
      if (bundle->dst.field) {
          nab->ofs_nbits = nxm_encode_ofs_nbits(bundle->dst.ofs,
                                                bundle->dst.n_bits);
          nab->dst = htonl(nxm_header_from_mff(bundle->dst.field));
      }
  
      slaves = ofpbuf_put_zeros(out, slaves_len);
      for (i = 0; i < bundle->n_slaves; i++) {
          slaves[i] = htons(ofp_to_u16(bundle->slaves[i]));
      }
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_BUNDLE(const char *arg, const struct ofpact_parse_params *pp)
  {
      return bundle_parse(arg, pp->port_map, pp->ofpacts);
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_bundle_load(const char *arg, const struct ofpact_parse_params *pp)
  {
      return bundle_parse_load(arg, pp->port_map, pp->ofpacts);
  }
  
  static void
  format_BUNDLE(const struct ofpact_bundle *a,
                const struct ofpact_format_params *fp)
  {
      bundle_format(a, fp->port_map, fp->s);
  }
  
  static enum ofperr
  check_BUNDLE(const struct ofpact_bundle *a,
               const struct ofpact_check_params *cp)
  {
      return bundle_check(a, cp->max_ports, cp->match);
  }
  
  /* Set VLAN actions. */
  
  static enum ofperr
  decode_set_vlan_vid(uint16_t vid, bool push_vlan_if_needed, struct ofpbuf *out)
  {
      if (vid & ~0xfff) {
          return OFPERR_OFPBAC_BAD_ARGUMENT;
      } else {
          struct ofpact_vlan_vid *vlan_vid = ofpact_put_SET_VLAN_VID(out);
          vlan_vid->vlan_vid = vid;
          vlan_vid->push_vlan_if_needed = push_vlan_if_needed;
          return 0;
      }
  }
  
  static enum ofperr
  decode_OFPAT_RAW10_SET_VLAN_VID(uint16_t vid,
                                  enum ofp_version ofp_version OVS_UNUSED,
                                  struct ofpbuf *out)
  {
      return decode_set_vlan_vid(vid, true, out);
  }
  
  static enum ofperr
  decode_OFPAT_RAW11_SET_VLAN_VID(uint16_t vid,
                                  enum ofp_version ofp_version OVS_UNUSED,
                                  struct ofpbuf *out)
  {
      return decode_set_vlan_vid(vid, false, out);
  }
  
  static void
  encode_SET_VLAN_VID(const struct ofpact_vlan_vid *vlan_vid,
                      enum ofp_version ofp_version, struct ofpbuf *out)
  {
      uint16_t vid = vlan_vid->vlan_vid;
  
      /* Push a VLAN tag, if none is present and this form of the action calls
       * for such a feature. */
      if (ofp_version > OFP10_VERSION
          && vlan_vid->push_vlan_if_needed
          && !vlan_vid->flow_has_vlan) {
          put_OFPAT11_PUSH_VLAN(out, htons(ETH_TYPE_VLAN_8021Q));
      }
  
      if (ofp_version == OFP10_VERSION) {
          put_OFPAT10_SET_VLAN_VID(out, vid);
      } else if (ofp_version == OFP11_VERSION) {
          put_OFPAT11_SET_VLAN_VID(out, vid);
      } else {
          put_set_field(out, ofp_version, MFF_VLAN_VID, vid | OFPVID12_PRESENT);
      }
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_set_vlan_vid(char *arg, bool push_vlan_if_needed,
                     const struct ofpact_parse_params *pp)
  {
      struct ofpact_vlan_vid *vlan_vid;
      uint16_t vid;
      char *error;
  
      error = str_to_u16(arg, "VLAN VID", &vid);
      if (error) {
          return error;
      }
  
      if (vid & ~VLAN_VID_MASK) {
          return xasprintf("%s: not a valid VLAN VID", arg);
      }
      vlan_vid = ofpact_put_SET_VLAN_VID(pp->ofpacts);
      vlan_vid->vlan_vid = vid;
      vlan_vid->push_vlan_if_needed = push_vlan_if_needed;
      return NULL;
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_SET_VLAN_VID(char *arg, const struct ofpact_parse_params *pp)
  {
      return parse_set_vlan_vid(arg, false, pp);
  }
  
  static void
  format_SET_VLAN_VID(const struct ofpact_vlan_vid *a,
                      const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%s%s:%s%"PRIu16, colors.param,
                    a->push_vlan_if_needed ? "mod_vlan_vid" : "set_vlan_vid",
                    colors.end, a->vlan_vid);
  }
  
  static enum ofperr
  check_SET_VLAN_VID(struct ofpact_vlan_vid *a, struct ofpact_check_params *cp)
  {
      /* Remember if we saw a vlan tag in the flow to aid translating to OpenFlow
       * 1.1+ if need be. */
      ovs_be16 *tci = &cp->match->flow.vlans[0].tci;
      a->flow_has_vlan = (*tci & htons(VLAN_CFI)) != 0;
      if (!a->flow_has_vlan && !a->push_vlan_if_needed) {
          inconsistent_match(&cp->usable_protocols);
      }
  
      /* Temporarily mark that we have a vlan tag. */
      *tci |= htons(VLAN_CFI);
  
      return 0;
  }
  
  /* Set PCP actions. */
  
  static enum ofperr
  decode_set_vlan_pcp(uint8_t pcp, bool push_vlan_if_needed, struct ofpbuf *out)
  {
      if (pcp & ~7) {
          return OFPERR_OFPBAC_BAD_ARGUMENT;
      } else {
          struct ofpact_vlan_pcp *vlan_pcp = ofpact_put_SET_VLAN_PCP(out);
          vlan_pcp->vlan_pcp = pcp;
          vlan_pcp->push_vlan_if_needed = push_vlan_if_needed;
          return 0;
      }
  }
  
  static enum ofperr
  decode_OFPAT_RAW10_SET_VLAN_PCP(uint8_t pcp,
                                  enum ofp_version ofp_version OVS_UNUSED,
                                  struct ofpbuf *out)
  {
      return decode_set_vlan_pcp(pcp, true, out);
  }
  
  static enum ofperr
  decode_OFPAT_RAW11_SET_VLAN_PCP(uint8_t pcp,
                                  enum ofp_version ofp_version OVS_UNUSED,
                                  struct ofpbuf *out)
  {
      return decode_set_vlan_pcp(pcp, false, out);
  }
  
  static void
  encode_SET_VLAN_PCP(const struct ofpact_vlan_pcp *vlan_pcp,
                      enum ofp_version ofp_version, struct ofpbuf *out)
  {
      uint8_t pcp = vlan_pcp->vlan_pcp;
  
      /* Push a VLAN tag, if none is present and this form of the action calls
       * for such a feature. */
      if (ofp_version > OFP10_VERSION
          && vlan_pcp->push_vlan_if_needed
          && !vlan_pcp->flow_has_vlan) {
          put_OFPAT11_PUSH_VLAN(out, htons(ETH_TYPE_VLAN_8021Q));
      }
  
      if (ofp_version == OFP10_VERSION) {
          put_OFPAT10_SET_VLAN_PCP(out, pcp);
      } else if (ofp_version == OFP11_VERSION) {
          put_OFPAT11_SET_VLAN_PCP(out, pcp);
      } else {
          put_set_field(out, ofp_version, MFF_VLAN_PCP, pcp);
      }
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_set_vlan_pcp(char *arg, bool push_vlan_if_needed,
                     const struct ofpact_parse_params *pp)
  {
      struct ofpact_vlan_pcp *vlan_pcp;
      uint8_t pcp;
      char *error;
  
      error = str_to_u8(arg, "VLAN PCP", &pcp);
      if (error) {
          return error;
      }
  
      if (pcp & ~7) {
          return xasprintf("%s: not a valid VLAN PCP", arg);
      }
      vlan_pcp = ofpact_put_SET_VLAN_PCP(pp->ofpacts);
      vlan_pcp->vlan_pcp = pcp;
      vlan_pcp->push_vlan_if_needed = push_vlan_if_needed;
      return NULL;
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_SET_VLAN_PCP(char *arg, const struct ofpact_parse_params *pp)
  {
      return parse_set_vlan_pcp(arg, false, pp);
  }
  
  static void
  format_SET_VLAN_PCP(const struct ofpact_vlan_pcp *a,
                      const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%s%s:%s%"PRIu8, colors.param,
                    a->push_vlan_if_needed ? "mod_vlan_pcp" : "set_vlan_pcp",
                    colors.end, a->vlan_pcp);
  }
  
  static enum ofperr
  check_SET_VLAN_PCP(struct ofpact_vlan_pcp *a, struct ofpact_check_params *cp)
  {
      /* Remember if we saw a vlan tag in the flow to aid translating to OpenFlow
       * 1.1+ if need be. */
      ovs_be16 *tci = &cp->match->flow.vlans[0].tci;
      a->flow_has_vlan = (*tci & htons(VLAN_CFI)) != 0;
      if (!a->flow_has_vlan && !a->push_vlan_if_needed) {
          inconsistent_match(&cp->usable_protocols);
      }
  
      /* Temporarily mark that we have a vlan tag. */
      *tci |= htons(VLAN_CFI);
  
      return 0;
  }
  
  /* Strip VLAN actions. */
  
  static enum ofperr
  decode_OFPAT_RAW10_STRIP_VLAN(struct ofpbuf *out)
  {
      ofpact_put_STRIP_VLAN(out)->ofpact.raw = OFPAT_RAW10_STRIP_VLAN;
      return 0;
  }
  
  static enum ofperr
  decode_OFPAT_RAW11_POP_VLAN(struct ofpbuf *out)
  {
      ofpact_put_STRIP_VLAN(out)->ofpact.raw = OFPAT_RAW11_POP_VLAN;
      return 0;
  }
  
  static void
  encode_STRIP_VLAN(const struct ofpact_null *null OVS_UNUSED,
                    enum ofp_version ofp_version, struct ofpbuf *out)
  {
      if (ofp_version == OFP10_VERSION) {
          put_OFPAT10_STRIP_VLAN(out);
      } else {
          put_OFPAT11_POP_VLAN(out);
      }
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_STRIP_VLAN(char *arg OVS_UNUSED, const struct ofpact_parse_params *pp)
  {
      ofpact_put_STRIP_VLAN(pp->ofpacts)->ofpact.raw = OFPAT_RAW10_STRIP_VLAN;
      return NULL;
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_pop_vlan(const struct ofpact_parse_params *pp)
  {
      ofpact_put_STRIP_VLAN(pp->ofpacts)->ofpact.raw = OFPAT_RAW11_POP_VLAN;
      return NULL;
  }
  
  static void
  format_STRIP_VLAN(const struct ofpact_null *a,
                    const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, (a->ofpact.raw == OFPAT_RAW11_POP_VLAN
                      ? "%spop_vlan%s"
                      : "%sstrip_vlan%s"),
                    colors.value, colors.end);
  }
  
  static enum ofperr
  check_STRIP_VLAN(const struct ofpact_null *a OVS_UNUSED,
                   struct ofpact_check_params *cp)
  {
      if (!(cp->match->flow.vlans[0].tci & htons(VLAN_CFI))) {
          inconsistent_match(&cp->usable_protocols);
      }
      flow_pop_vlan(&cp->match->flow, NULL);
      return 0;
  }
  
  /* Push VLAN action. */
  
  static enum ofperr
  decode_OFPAT_RAW11_PUSH_VLAN(ovs_be16 eth_type,
                               enum ofp_version ofp_version OVS_UNUSED,
                               struct ofpbuf *out)
  {
      struct ofpact_push_vlan *push_vlan;
      if (!eth_type_vlan(eth_type)) {
          return OFPERR_OFPBAC_BAD_ARGUMENT;
      }
      push_vlan = ofpact_put_PUSH_VLAN(out);
      push_vlan->ethertype = eth_type;
      return 0;
  }
  
  static void
  encode_PUSH_VLAN(const struct ofpact_push_vlan *push_vlan,
                   enum ofp_version ofp_version, struct ofpbuf *out)
  {
      if (ofp_version == OFP10_VERSION) {
          /* PUSH is a side effect of a SET_VLAN_VID/PCP, which should
           * follow this action. */
      } else {
          put_OFPAT11_PUSH_VLAN(out, push_vlan->ethertype);
      }
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_PUSH_VLAN(char *arg, const struct ofpact_parse_params *pp)
  {
      struct ofpact_push_vlan *push_vlan;
      uint16_t ethertype;
      char *error;
  
      *pp->usable_protocols &= OFPUTIL_P_OF11_UP;
      error = str_to_u16(arg, "ethertype", &ethertype);
      if (error) {
          return error;
      }
  
      if (!eth_type_vlan(htons(ethertype))) {
          return xasprintf("%s: not a valid VLAN ethertype", arg);
      }
      push_vlan = ofpact_put_PUSH_VLAN(pp->ofpacts);
      push_vlan->ethertype = htons(ethertype);
      return NULL;
  }
  
  static void
  format_PUSH_VLAN(const struct ofpact_push_vlan *push_vlan,
                   const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%spush_vlan:%s%#"PRIx16,
                    colors.param, colors.end, ntohs(push_vlan->ethertype));
  }
  
  static enum ofperr
  check_PUSH_VLAN(const struct ofpact_push_vlan *a OVS_UNUSED,
                  struct ofpact_check_params *cp)
  {
      struct flow *flow = &cp->match->flow;
      if (flow->vlans[FLOW_MAX_VLAN_HEADERS - 1].tci & htons(VLAN_CFI)) {
          /* Support maximum (FLOW_MAX_VLAN_HEADERS) VLAN headers. */
          return OFPERR_OFPBAC_BAD_TAG;
      }
      /* Temporary mark that we have a vlan tag. */
      flow_push_vlan_uninit(flow, NULL);
      flow->vlans[0].tci |= htons(VLAN_CFI);
      return 0;
  }
  
  /* Action structure for OFPAT10_SET_DL_SRC/DST and OFPAT11_SET_DL_SRC/DST. */
  struct ofp_action_dl_addr {
      ovs_be16 type;                  /* Type. */
      ovs_be16 len;                   /* Length is 16. */
      struct eth_addr dl_addr;        /* Ethernet address. */
      uint8_t pad[6];
  };
  OFP_ASSERT(sizeof(struct ofp_action_dl_addr) == 16);
  
  static enum ofperr
  decode_OFPAT_RAW_SET_DL_SRC(const struct ofp_action_dl_addr *a,
                              enum ofp_version ofp_version OVS_UNUSED,
                              struct ofpbuf *out)
  {
      ofpact_put_SET_ETH_SRC(out)->mac = a->dl_addr;
      return 0;
  }
  
  static enum ofperr
  decode_OFPAT_RAW_SET_DL_DST(const struct ofp_action_dl_addr *a,
                              enum ofp_version ofp_version OVS_UNUSED,
                              struct ofpbuf *out)
  {
      ofpact_put_SET_ETH_DST(out)->mac = a->dl_addr;
      return 0;
  }
  
  static void
  encode_SET_ETH_addr(const struct ofpact_mac *mac, enum ofp_version ofp_version,
                      enum ofp_raw_action_type raw, enum mf_field_id field,
                      struct ofpbuf *out)
  {
      if (ofp_version < OFP12_VERSION) {
          struct ofp_action_dl_addr *oada;
  
          oada = ofpact_put_raw(out, ofp_version, raw, 0);
          oada->dl_addr = mac->mac;
      } else {
          put_set_field(out, ofp_version, field, eth_addr_to_uint64(mac->mac));
      }
  }
  
  static void
  encode_SET_ETH_SRC(const struct ofpact_mac *mac, enum ofp_version ofp_version,
                     struct ofpbuf *out)
  {
      encode_SET_ETH_addr(mac, ofp_version, OFPAT_RAW_SET_DL_SRC, MFF_ETH_SRC,
                          out);
  
  }
  
  static void
  encode_SET_ETH_DST(const struct ofpact_mac *mac,
                                 enum ofp_version ofp_version,
                                 struct ofpbuf *out)
  {
      encode_SET_ETH_addr(mac, ofp_version, OFPAT_RAW_SET_DL_DST, MFF_ETH_DST,
                          out);
  
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_SET_ETH_SRC(char *arg, const struct ofpact_parse_params *pp)
  {
      return str_to_mac(arg, &ofpact_put_SET_ETH_SRC(pp->ofpacts)->mac);
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_SET_ETH_DST(char *arg, const struct ofpact_parse_params *pp)
  {
      return str_to_mac(arg, &ofpact_put_SET_ETH_DST(pp->ofpacts)->mac);
  }
  
  static void
  format_SET_ETH_SRC(const struct ofpact_mac *a,
                     const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%smod_dl_src:%s"ETH_ADDR_FMT,
                    colors.param, colors.end, ETH_ADDR_ARGS(a->mac));
  }
  
  static void
  format_SET_ETH_DST(const struct ofpact_mac *a,
                     const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%smod_dl_dst:%s"ETH_ADDR_FMT,
                    colors.param, colors.end, ETH_ADDR_ARGS(a->mac));
  }
  
  static enum ofperr
  check_SET_ETH_SRC(const struct ofpact_mac *a OVS_UNUSED,
                    const struct ofpact_check_params *cp OVS_UNUSED)
  {
      return 0;
  }
  
  static enum ofperr
  check_SET_ETH_DST(const struct ofpact_mac *a OVS_UNUSED,
                    const struct ofpact_check_params *cp OVS_UNUSED)
  {
      return 0;
  }
  
  /* Set IPv4 address actions. */
  
  static enum ofperr
  decode_OFPAT_RAW_SET_NW_SRC(ovs_be32 ipv4,
                              enum ofp_version ofp_version OVS_UNUSED,
                              struct ofpbuf *out)
  {
      ofpact_put_SET_IPV4_SRC(out)->ipv4 = ipv4;
      return 0;
  }
  
  static enum ofperr
  decode_OFPAT_RAW_SET_NW_DST(ovs_be32 ipv4,
                              enum ofp_version ofp_version OVS_UNUSED,
                              struct ofpbuf *out)
  {
      ofpact_put_SET_IPV4_DST(out)->ipv4 = ipv4;
      return 0;
  }
  
  static void
  encode_SET_IPV4_addr(const struct ofpact_ipv4 *ipv4,
                       enum ofp_version ofp_version,
                       enum ofp_raw_action_type raw, enum mf_field_id field,
                       struct ofpbuf *out)
  {
      ovs_be32 addr = ipv4->ipv4;
      if (ofp_version < OFP12_VERSION) {
          ofpact_put_raw(out, ofp_version, raw, ntohl(addr));
      } else {
          put_set_field(out, ofp_version, field, ntohl(addr));
      }
  }
  
  static void
  encode_SET_IPV4_SRC(const struct ofpact_ipv4 *ipv4,
                      enum ofp_version ofp_version, struct ofpbuf *out)
  {
      encode_SET_IPV4_addr(ipv4, ofp_version, OFPAT_RAW_SET_NW_SRC, MFF_IPV4_SRC,
                           out);
  }
  
  static void
  encode_SET_IPV4_DST(const struct ofpact_ipv4 *ipv4,
                      enum ofp_version ofp_version, struct ofpbuf *out)
  {
      encode_SET_IPV4_addr(ipv4, ofp_version, OFPAT_RAW_SET_NW_DST, MFF_IPV4_DST,
                           out);
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_SET_IPV4_SRC(char *arg, const struct ofpact_parse_params *pp)
  {
      return str_to_ip(arg, &ofpact_put_SET_IPV4_SRC(pp->ofpacts)->ipv4);
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_SET_IPV4_DST(char *arg, const struct ofpact_parse_params *pp)
  {
      return str_to_ip(arg, &ofpact_put_SET_IPV4_DST(pp->ofpacts)->ipv4);
  }
  
  static void
  format_SET_IPV4_SRC(const struct ofpact_ipv4 *a,
                      const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%smod_nw_src:%s"IP_FMT,
                    colors.param, colors.end, IP_ARGS(a->ipv4));
  }
  
  static void
  format_SET_IPV4_DST(const struct ofpact_ipv4 *a,
                      const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%smod_nw_dst:%s"IP_FMT,
                    colors.param, colors.end, IP_ARGS(a->ipv4));
  }
  
  static enum ofperr
  check_set_ipv4(struct ofpact_check_params *cp)
  {
      ovs_be16 dl_type = get_dl_type(&cp->match->flow);
      if (dl_type != htons(ETH_TYPE_IP)) {
          inconsistent_match(&cp->usable_protocols);
      }
      return 0;
  }
  
  static enum ofperr
  check_SET_IPV4_SRC(const struct ofpact_ipv4 *a OVS_UNUSED,
                     struct ofpact_check_params *cp)
  {
      return check_set_ipv4(cp);
  }
  
  static enum ofperr
  check_SET_IPV4_DST(const struct ofpact_ipv4 *a OVS_UNUSED,
                     struct ofpact_check_params *cp)
  {
      return check_set_ipv4(cp);
  }
  
  /* Set IPv4/v6 TOS actions. */
  
  static enum ofperr
  decode_OFPAT_RAW_SET_NW_TOS(uint8_t dscp,
                              enum ofp_version ofp_version OVS_UNUSED,
                              struct ofpbuf *out)
  {
      if (dscp & ~IP_DSCP_MASK) {
          return OFPERR_OFPBAC_BAD_ARGUMENT;
      } else {
          ofpact_put_SET_IP_DSCP(out)->dscp = dscp;
          return 0;
      }
  }
  
  static void
  encode_SET_IP_DSCP(const struct ofpact_dscp *dscp,
                     enum ofp_version ofp_version, struct ofpbuf *out)
  {
      if (ofp_version < OFP12_VERSION) {
          put_OFPAT_SET_NW_TOS(out, ofp_version, dscp->dscp);
      } else {
          put_set_field(out, ofp_version, MFF_IP_DSCP_SHIFTED, dscp->dscp >> 2);
      }
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_SET_IP_DSCP(char *arg, const struct ofpact_parse_params *pp)
  
  {
      uint8_t tos;
      char *error;
  
      error = str_to_u8(arg, "TOS", &tos);
      if (error) {
          return error;
      }
  
      if (tos & ~IP_DSCP_MASK) {
          return xasprintf("%s: not a valid TOS", arg);
      }
      ofpact_put_SET_IP_DSCP(pp->ofpacts)->dscp = tos;
      return NULL;
  }
  
  static void
  format_SET_IP_DSCP(const struct ofpact_dscp *a,
                     const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%smod_nw_tos:%s%d",
                    colors.param, colors.end, a->dscp);
  }
  
  static enum ofperr
  check_set_ip(struct ofpact_check_params *cp)
  {
      if (!is_ip_any(&cp->match->flow)) {
          inconsistent_match(&cp->usable_protocols);
      }
      return 0;
  }
  
  static enum ofperr
  check_SET_IP_DSCP(const struct ofpact_dscp *a OVS_UNUSED,
                    struct ofpact_check_params *cp)
  {
      return check_set_ip(cp);
  }
  
  /* Set IPv4/v6 ECN actions. */
  
  static enum ofperr
  decode_OFPAT_RAW11_SET_NW_ECN(uint8_t ecn,
                                enum ofp_version ofp_version OVS_UNUSED,
                                struct ofpbuf *out)
  {
      if (ecn & ~IP_ECN_MASK) {
          return OFPERR_OFPBAC_BAD_ARGUMENT;
      } else {
          ofpact_put_SET_IP_ECN(out)->ecn = ecn;
          return 0;
      }
  }
  
  static void
  encode_SET_IP_ECN(const struct ofpact_ecn *ip_ecn,
                    enum ofp_version ofp_version, struct ofpbuf *out)
  {
      uint8_t ecn = ip_ecn->ecn;
      if (ofp_version == OFP10_VERSION) {
          struct mf_subfield dst = { .field = mf_from_id(MFF_IP_ECN),
                                     .ofs = 0, .n_bits = 2 };
          put_reg_load(out, &dst, ecn);
      } else if (ofp_version == OFP11_VERSION) {
          put_OFPAT11_SET_NW_ECN(out, ecn);
      } else {
          put_set_field(out, ofp_version, MFF_IP_ECN, ecn);
      }
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_SET_IP_ECN(char *arg, const struct ofpact_parse_params *pp)
  {
      uint8_t ecn;
      char *error;
  
      error = str_to_u8(arg, "ECN", &ecn);
      if (error) {
          return error;
      }
  
      if (ecn & ~IP_ECN_MASK) {
          return xasprintf("%s: not a valid ECN", arg);
      }
      ofpact_put_SET_IP_ECN(pp->ofpacts)->ecn = ecn;
      return NULL;
  }
  
  static void
  format_SET_IP_ECN(const struct ofpact_ecn *a,
                    const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%smod_nw_ecn:%s%d",
                    colors.param, colors.end, a->ecn);
  }
  
  static enum ofperr
  check_SET_IP_ECN(const struct ofpact_ecn *a OVS_UNUSED,
                   struct ofpact_check_params *cp)
  {
      return check_set_ip(cp);
  }
  
  /* Set IPv4/v6 TTL actions. */
  
  static enum ofperr
  decode_OFPAT_RAW11_SET_NW_TTL(uint8_t ttl,
                                enum ofp_version ofp_version OVS_UNUSED,
                                struct ofpbuf *out)
  {
      ofpact_put_SET_IP_TTL(out)->ttl = ttl;
      return 0;
  }
  
  static void
  encode_SET_IP_TTL(const struct ofpact_ip_ttl *ttl,
                    enum ofp_version ofp_version, struct ofpbuf *out)
  {
      if (ofp_version >= OFP11_VERSION) {
          put_OFPAT11_SET_NW_TTL(out, ttl->ttl);
      } else {
          struct mf_subfield dst = { .field = mf_from_id(MFF_IP_TTL),
                                     .ofs = 0, .n_bits = 8 };
          put_reg_load(out, &dst, ttl->ttl);
      }
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_SET_IP_TTL(char *arg, const struct ofpact_parse_params *pp)
  
  {
      uint8_t ttl;
      char *error;
  
      error = str_to_u8(arg, "TTL", &ttl);
      if (error) {
          return error;
      }
  
      ofpact_put_SET_IP_TTL(pp->ofpacts)->ttl = ttl;
      return NULL;
  }
  
  static void
  format_SET_IP_TTL(const struct ofpact_ip_ttl *a,
                    const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%smod_nw_ttl:%s%d",
                    colors.param, colors.end, a->ttl);
  }
  
  static enum ofperr
  check_SET_IP_TTL(const struct ofpact_ip_ttl *a OVS_UNUSED,
                   struct ofpact_check_params *cp)
  {
      return check_set_ip(cp);
  }
  
  /* Set TCP/UDP/SCTP port actions. */
  
  static enum ofperr
  decode_OFPAT_RAW_SET_TP_SRC(ovs_be16 port,
                              enum ofp_version ofp_version OVS_UNUSED,
                              struct ofpbuf *out)
  {
      ofpact_put_SET_L4_SRC_PORT(out)->port = ntohs(port);
      return 0;
  }
  
  static enum ofperr
  decode_OFPAT_RAW_SET_TP_DST(ovs_be16 port,
                              enum ofp_version ofp_version OVS_UNUSED,
                              struct ofpbuf *out)
  {
      ofpact_put_SET_L4_DST_PORT(out)->port = ntohs(port);
      return 0;
  }
  
  static void
  encode_SET_L4_port(const struct ofpact_l4_port *l4_port,
                     enum ofp_version ofp_version, enum ofp_raw_action_type raw,
                     enum mf_field_id field, struct ofpbuf *out)
  {
      uint16_t port = l4_port->port;
  
      if (ofp_version >= OFP12_VERSION && field != MFF_N_IDS) {
          put_set_field(out, ofp_version, field, port);
      } else {
          ofpact_put_raw(out, ofp_version, raw, port);
      }
  }
  
  static void
  encode_SET_L4_SRC_PORT(const struct ofpact_l4_port *l4_port,
                         enum ofp_version ofp_version, struct ofpbuf *out)
  {
      uint8_t proto = l4_port->flow_ip_proto;
      enum mf_field_id field = (proto == IPPROTO_TCP ? MFF_TCP_SRC
                                : proto == IPPROTO_UDP ? MFF_UDP_SRC
                                : proto == IPPROTO_SCTP ? MFF_SCTP_SRC
                                : MFF_N_IDS);
  
      encode_SET_L4_port(l4_port, ofp_version, OFPAT_RAW_SET_TP_SRC, field, out);
  }
  
  static void
  encode_SET_L4_DST_PORT(const struct ofpact_l4_port *l4_port,
                         enum ofp_version ofp_version,
                         struct ofpbuf *out)
  {
      uint8_t proto = l4_port->flow_ip_proto;
      enum mf_field_id field = (proto == IPPROTO_TCP ? MFF_TCP_DST
                                : proto == IPPROTO_UDP ? MFF_UDP_DST
                                : proto == IPPROTO_SCTP ? MFF_SCTP_DST
                                : MFF_N_IDS);
  
      encode_SET_L4_port(l4_port, ofp_version, OFPAT_RAW_SET_TP_DST, field, out);
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_SET_L4_SRC_PORT(char *arg, const struct ofpact_parse_params *pp)
  {
      return str_to_u16(arg, "source port",
                        &ofpact_put_SET_L4_SRC_PORT(pp->ofpacts)->port);
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_SET_L4_DST_PORT(char *arg, const struct ofpact_parse_params *pp)
  {
      return str_to_u16(arg, "destination port",
                        &ofpact_put_SET_L4_DST_PORT(pp->ofpacts)->port);
  }
  
  static void
  format_SET_L4_SRC_PORT(const struct ofpact_l4_port *a,
                         const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%smod_tp_src:%s%d",
                    colors.param, colors.end, a->port);
  }
  
  static void
  format_SET_L4_DST_PORT(const struct ofpact_l4_port *a,
                         const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%smod_tp_dst:%s%d",
                    colors.param, colors.end, a->port);
  }
  
  static enum ofperr
  check_set_l4_port(struct ofpact_l4_port *a, struct ofpact_check_params *cp)
  {
      const struct flow *flow = &cp->match->flow;
      if (!is_ip_any(flow)
          || flow->nw_frag & FLOW_NW_FRAG_LATER
          || (flow->nw_proto != IPPROTO_TCP &&
              flow->nw_proto != IPPROTO_UDP &&
              flow->nw_proto != IPPROTO_SCTP)) {
          inconsistent_match(&cp->usable_protocols);
      }
  
      /* Note the transport protocol in use, to allow this action to be converted
       * to an OF1.2 set_field action later if necessary. */
      a->flow_ip_proto = flow->nw_proto;
  
      return 0;
  }
  
  static enum ofperr
  check_SET_L4_SRC_PORT(struct ofpact_l4_port *a, struct ofpact_check_params *cp)
  {
      return check_set_l4_port(a, cp);
  }
  
  static enum ofperr
  check_SET_L4_DST_PORT(struct ofpact_l4_port *a, struct ofpact_check_params *cp)
  {
      return check_set_l4_port(a, cp);
  }
  
  /* Action structure for OFPAT_COPY_FIELD. */
  struct ofp15_action_copy_field {
      ovs_be16 type;              /* OFPAT_COPY_FIELD. */
      ovs_be16 len;               /* Length is padded to 64 bits. */
      ovs_be16 n_bits;            /* Number of bits to copy. */
      ovs_be16 src_offset;        /* Starting bit offset in source. */
      ovs_be16 dst_offset;        /* Starting bit offset in destination. */
      uint8_t pad[2];
      /* Followed by:
       * - OXM header for source field.
       * - OXM header for destination field.
       * - Padding with 0-bytes to a multiple of 8 bytes.
       * The "pad2" member is the beginning of the above. */
      uint8_t pad2[4];
  };
  OFP_ASSERT(sizeof(struct ofp15_action_copy_field) == 16);
  
  /* Action structure for OpenFlow 1.3 extension copy-field action.. */
  struct onf_action_copy_field {
      ovs_be16 type;              /* OFPAT_EXPERIMENTER. */
      ovs_be16 len;               /* Length is padded to 64 bits. */
      ovs_be32 experimenter;      /* ONF_VENDOR_ID. */
      ovs_be16 exp_type;          /* 3200. */
      uint8_t pad[2];             /* Not used. */
      ovs_be16 n_bits;            /* Number of bits to copy. */
      ovs_be16 src_offset;        /* Starting bit offset in source. */
      ovs_be16 dst_offset;        /* Starting bit offset in destination. */
      uint8_t pad2[2];            /* Not used. */
      /* Followed by:
       * - OXM header for source field.
       * - OXM header for destination field.
       * - Padding with 0-bytes (either 0 or 4 of them) to a multiple of 8 bytes.
       * The "pad3" member is the beginning of the above. */
      uint8_t pad3[4];            /* Not used. */
  };
  OFP_ASSERT(sizeof(struct onf_action_copy_field) == 24);
  
  /* Action structure for NXAST_REG_MOVE.
   *
   * Copies src[src_ofs:src_ofs+n_bits] to dst[dst_ofs:dst_ofs+n_bits], where
   * a[b:c] denotes the bits within 'a' numbered 'b' through 'c' (not including
   * bit 'c').  Bit numbering starts at 0 for the least-significant bit, 1 for
   * the next most significant bit, and so on.
   *
   * 'src' and 'dst' are nxm_header values with nxm_hasmask=0.  (It doesn't make
   * sense to use nxm_hasmask=1 because the action does not do any kind of
   * matching; it uses the actual value of a field.)
   *
   * The following nxm_header values are potentially acceptable as 'src':
   *
   *   - NXM_OF_IN_PORT
   *   - NXM_OF_ETH_DST
   *   - NXM_OF_ETH_SRC
   *   - NXM_OF_ETH_TYPE
   *   - NXM_OF_VLAN_TCI
   *   - NXM_OF_IP_TOS
   *   - NXM_OF_IP_PROTO
   *   - NXM_OF_IP_SRC
   *   - NXM_OF_IP_DST
   *   - NXM_OF_TCP_SRC
   *   - NXM_OF_TCP_DST
   *   - NXM_OF_UDP_SRC
   *   - NXM_OF_UDP_DST
   *   - NXM_OF_ICMP_TYPE
   *   - NXM_OF_ICMP_CODE
   *   - NXM_OF_ARP_OP
   *   - NXM_OF_ARP_SPA
   *   - NXM_OF_ARP_TPA
   *   - NXM_NX_TUN_ID
   *   - NXM_NX_ARP_SHA
   *   - NXM_NX_ARP_THA
   *   - NXM_NX_ICMPV6_TYPE
   *   - NXM_NX_ICMPV6_CODE
   *   - NXM_NX_ND_SLL
   *   - NXM_NX_ND_TLL
   *   - NXM_NX_REG(idx) for idx in the switch's accepted range.
   *   - NXM_NX_PKT_MARK
   *   - NXM_NX_TUN_IPV4_SRC
   *   - NXM_NX_TUN_IPV4_DST
   *
   * The following nxm_header values are potentially acceptable as 'dst':
   *
   *   - NXM_OF_ETH_DST
   *   - NXM_OF_ETH_SRC
   *   - NXM_OF_IP_TOS
   *   - NXM_OF_IP_SRC
   *   - NXM_OF_IP_DST
   *   - NXM_OF_TCP_SRC
   *   - NXM_OF_TCP_DST
   *   - NXM_OF_UDP_SRC
   *   - NXM_OF_UDP_DST
   *   - NXM_OF_ICMP_TYPE
   *   - NXM_OF_ICMP_CODE
   *   - NXM_NX_ICMPV6_TYPE
   *   - NXM_NX_ICMPV6_CODE
   *   - NXM_NX_ARP_SHA
   *   - NXM_NX_ARP_THA
   *   - NXM_OF_ARP_OP
   *   - NXM_OF_ARP_SPA
   *   - NXM_OF_ARP_TPA
   *     Modifying any of the above fields changes the corresponding packet
   *     header.
   *
   *   - NXM_OF_IN_PORT
   *
   *   - NXM_NX_REG(idx) for idx in the switch's accepted range.
   *
   *   - NXM_NX_PKT_MARK
   *
   *   - NXM_OF_VLAN_TCI.  Modifying this field's value has side effects on the
   *     packet's 802.1Q header.  Setting a value with CFI=0 removes the 802.1Q
   *     header (if any), ignoring the other bits.  Setting a value with CFI=1
   *     adds or modifies the 802.1Q header appropriately, setting the TCI field
   *     to the field's new value (with the CFI bit masked out).
   *
   *   - NXM_NX_TUN_ID, NXM_NX_TUN_IPV4_SRC, NXM_NX_TUN_IPV4_DST.  Modifying
   *     any of these values modifies the corresponding tunnel header field used
   *     for the packet's next tunnel encapsulation, if allowed by the
   *     configuration of the output tunnel port.
   *
   * A given nxm_header value may be used as 'src' or 'dst' only on a flow whose
   * nx_match satisfies its prerequisites.  For example, NXM_OF_IP_TOS may be
   * used only if the flow's nx_match includes an nxm_entry that specifies
   * nxm_type=NXM_OF_ETH_TYPE, nxm_hasmask=0, and nxm_value=0x0800.
   *
   * The switch will reject actions for which src_ofs+n_bits is greater than the
   * width of 'src' or dst_ofs+n_bits is greater than the width of 'dst' with
   * error type OFPET_BAD_ACTION, code OFPBAC_BAD_ARGUMENT.
   *
   * This action behaves properly when 'src' overlaps with 'dst', that is, it
   * behaves as if 'src' were copied out to a temporary buffer, then the
   * temporary buffer copied to 'dst'.
   */
  struct nx_action_reg_move {
      ovs_be16 type;                  /* OFPAT_VENDOR. */
      ovs_be16 len;                   /* Length is 24. */
      ovs_be32 vendor;                /* NX_VENDOR_ID. */
      ovs_be16 subtype;               /* NXAST_REG_MOVE. */
      ovs_be16 n_bits;                /* Number of bits. */
      ovs_be16 src_ofs;               /* Starting bit offset in source. */
      ovs_be16 dst_ofs;               /* Starting bit offset in destination. */
      /* Followed by:
       * - OXM/NXM header for source field (4 or 8 bytes).
       * - OXM/NXM header for destination field (4 or 8 bytes).
       * - Padding with 0-bytes to a multiple of 8 bytes, if necessary. */
  };
  OFP_ASSERT(sizeof(struct nx_action_reg_move) == 16);
  
  static enum ofperr
  decode_copy_field__(ovs_be16 src_offset, ovs_be16 dst_offset, ovs_be16 n_bits,
                      const void *action, ovs_be16 action_len, size_t oxm_offset,
                      const struct vl_mff_map *vl_mff_map,
                      uint64_t *tlv_bitmap, struct ofpbuf *ofpacts)
  {
      struct ofpact_reg_move *move = ofpact_put_REG_MOVE(ofpacts);
      enum ofperr error;
  
      move->ofpact.raw = ONFACT_RAW13_COPY_FIELD;
      move->src.ofs = ntohs(src_offset);
      move->src.n_bits = ntohs(n_bits);
      move->dst.ofs = ntohs(dst_offset);
      move->dst.n_bits = ntohs(n_bits);
  
      struct ofpbuf b = ofpbuf_const_initializer(action, ntohs(action_len));
      ofpbuf_pull(&b, oxm_offset);
  
      error = mf_vl_mff_nx_pull_header(&b, vl_mff_map, &move->src.field, NULL,
                                       tlv_bitmap);
      if (error) {
          return error;
      }
      error = mf_vl_mff_nx_pull_header(&b, vl_mff_map, &move->dst.field, NULL,
                                       tlv_bitmap);
      if (error) {
          return error;
      }
  
      if (!is_all_zeros(b.data, b.size)) {
          return OFPERR_NXBRC_MUST_BE_ZERO;
      }
  
      return nxm_reg_move_check(move, NULL);
  }
  
  static enum ofperr
  decode_OFPAT_RAW15_COPY_FIELD(const struct ofp15_action_copy_field *oacf,
                                enum ofp_version ofp_version OVS_UNUSED,
                                const struct vl_mff_map *vl_mff_map,
                                uint64_t *tlv_bitmap, struct ofpbuf *ofpacts)
  {
      return decode_copy_field__(oacf->src_offset, oacf->dst_offset,
                                 oacf->n_bits, oacf, oacf->len,
                                 OBJECT_OFFSETOF(oacf, pad2), vl_mff_map,
                                 tlv_bitmap, ofpacts);
  }
  
  static enum ofperr
  decode_ONFACT_RAW13_COPY_FIELD(const struct onf_action_copy_field *oacf,
                                 enum ofp_version ofp_version OVS_UNUSED,
                                 const struct vl_mff_map *vl_mff_map,
                                 uint64_t *tlv_bitmap, struct ofpbuf *ofpacts)
  {
      return decode_copy_field__(oacf->src_offset, oacf->dst_offset,
                                 oacf->n_bits, oacf, oacf->len,
                                 OBJECT_OFFSETOF(oacf, pad3), vl_mff_map,
                                 tlv_bitmap, ofpacts);
  }
  
  static enum ofperr
  decode_NXAST_RAW_REG_MOVE(const struct nx_action_reg_move *narm,
                            enum ofp_version ofp_version OVS_UNUSED,
                            const struct vl_mff_map *vl_mff_map,
                            uint64_t *tlv_bitmap, struct ofpbuf *ofpacts)
  {
      struct ofpact_reg_move *move = ofpact_put_REG_MOVE(ofpacts);
      enum ofperr error;
  
      move->ofpact.raw = NXAST_RAW_REG_MOVE;
      move->src.ofs = ntohs(narm->src_ofs);
      move->src.n_bits = ntohs(narm->n_bits);
      move->dst.ofs = ntohs(narm->dst_ofs);
      move->dst.n_bits = ntohs(narm->n_bits);
  
      struct ofpbuf b = ofpbuf_const_initializer(narm, ntohs(narm->len));
      ofpbuf_pull(&b, sizeof *narm);
  
      error = mf_vl_mff_nx_pull_header(&b, vl_mff_map, &move->src.field, NULL,
                                       tlv_bitmap);
      if (error) {
          return error;
      }
  
      error = mf_vl_mff_nx_pull_header(&b, vl_mff_map, &move->dst.field, NULL,
                                       tlv_bitmap);
      if (error) {
          return error;
      }
  
      if (!is_all_zeros(b.data, b.size)) {
          return OFPERR_NXBRC_MUST_BE_ZERO;
      }
  
      return nxm_reg_move_check(move, NULL);
  }
  
  static void
  encode_REG_MOVE(const struct ofpact_reg_move *move,
                  enum ofp_version ofp_version, struct ofpbuf *out)
  {
      /* For OpenFlow 1.3, the choice of ONFACT_RAW13_COPY_FIELD versus
       * NXAST_RAW_REG_MOVE is somewhat difficult.  Neither one is guaranteed to
       * be supported by every OpenFlow 1.3 implementation.  It would be ideal to
       * probe for support.  Until we have that ability, we currently prefer
       * NXAST_RAW_REG_MOVE for backward compatibility with older Open vSwitch
       * versions.  */
      size_t start_ofs = out->size;
      if (ofp_version >= OFP15_VERSION) {
          struct ofp15_action_copy_field *copy = put_OFPAT15_COPY_FIELD(out);
          copy->n_bits = htons(move->dst.n_bits);
          copy->src_offset = htons(move->src.ofs);
          copy->dst_offset = htons(move->dst.ofs);
          out->size = out->size - sizeof copy->pad2;
          nx_put_mff_header(out, move->src.field, ofp_version, false);
          nx_put_mff_header(out, move->dst.field, ofp_version, false);
      } else if (ofp_version == OFP13_VERSION
                 && move->ofpact.raw == ONFACT_RAW13_COPY_FIELD) {
          struct onf_action_copy_field *copy = put_ONFACT13_COPY_FIELD(out);
          copy->n_bits = htons(move->dst.n_bits);
          copy->src_offset = htons(move->src.ofs);
          copy->dst_offset = htons(move->dst.ofs);
          out->size = out->size - sizeof copy->pad3;
          nx_put_mff_header(out, move->src.field, ofp_version, false);
          nx_put_mff_header(out, move->dst.field, ofp_version, false);
      } else {
          struct nx_action_reg_move *narm = put_NXAST_REG_MOVE(out);
          narm->n_bits = htons(move->dst.n_bits);
          narm->src_ofs = htons(move->src.ofs);
          narm->dst_ofs = htons(move->dst.ofs);
          nx_put_mff_header(out, move->src.field, 0, false);
          nx_put_mff_header(out, move->dst.field, 0, false);
      }
      pad_ofpat(out, start_ofs);
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_REG_MOVE(const char *arg, const struct ofpact_parse_params *pp)
  {
      struct ofpact_reg_move *move = ofpact_put_REG_MOVE(pp->ofpacts);
      return nxm_parse_reg_move(move, arg);
  }
  
  static void
  format_REG_MOVE(const struct ofpact_reg_move *a,
                  const struct ofpact_format_params *fp)
  {
      nxm_format_reg_move(a, fp->s);
  }
  
  static enum ofperr
  check_REG_MOVE(const struct ofpact_reg_move *a,
                 const struct ofpact_check_params *cp)
  {
      return nxm_reg_move_check(a, cp->match);
  }
  
  /* Action structure for OFPAT12_SET_FIELD. */
  struct ofp12_action_set_field {
      ovs_be16 type;                  /* OFPAT12_SET_FIELD. */
      ovs_be16 len;                   /* Length is padded to 64 bits. */
  
      /* Followed by:
       * - An OXM header, value, and (in OpenFlow 1.5+) optionally a mask.
       * - Enough 0-bytes to pad out to a multiple of 64 bits.
       *
       * The "pad" member is the beginning of the above. */
      uint8_t pad[4];
  };
  OFP_ASSERT(sizeof(struct ofp12_action_set_field) == 8);
  
  /* Action structure for NXAST_REG_LOAD.
   *
   * Copies value[0:n_bits] to dst[ofs:ofs+n_bits], where a[b:c] denotes the bits
   * within 'a' numbered 'b' through 'c' (not including bit 'c').  Bit numbering
   * starts at 0 for the least-significant bit, 1 for the next most significant
   * bit, and so on.
   *
   * 'dst' is an nxm_header with nxm_hasmask=0.  See the documentation for
   * NXAST_REG_MOVE, above, for the permitted fields and for the side effects of
   * loading them.
   *
   * The 'ofs' and 'n_bits' fields are combined into a single 'ofs_nbits' field
   * to avoid enlarging the structure by another 8 bytes.  To allow 'n_bits' to
   * take a value between 1 and 64 (inclusive) while taking up only 6 bits, it is
   * also stored as one less than its true value:
   *
   *  15                           6 5                0
   * +------------------------------+------------------+
   * |              ofs             |    n_bits - 1    |
   * +------------------------------+------------------+
   *
   * The switch will reject actions for which ofs+n_bits is greater than the
   * width of 'dst', or in which any bits in 'value' with value 2**n_bits or
   * greater are set to 1, with error type OFPET_BAD_ACTION, code
   * OFPBAC_BAD_ARGUMENT.
   */
  struct nx_action_reg_load {
      ovs_be16 type;                  /* OFPAT_VENDOR. */
      ovs_be16 len;                   /* Length is 24. */
      ovs_be32 vendor;                /* NX_VENDOR_ID. */
      ovs_be16 subtype;               /* NXAST_REG_LOAD. */
      ovs_be16 ofs_nbits;             /* (ofs << 6) | (n_bits - 1). */
      ovs_be32 dst;                   /* Destination register. */
      ovs_be64 value;                 /* Immediate value. */
  };
  OFP_ASSERT(sizeof(struct nx_action_reg_load) == 24);
  
  /* The NXAST_REG_LOAD2 action structure is "struct ext_action_header",
   * followed by:
   *
   * - An NXM/OXM header, value, and optionally a mask.
   * - Enough 0-bytes to pad out to a multiple of 64 bits.
   *
   * The "pad" member is the beginning of the above. */
  
  static enum ofperr
  decode_ofpat_set_field(const struct ofp12_action_set_field *oasf,
                         bool may_mask, const struct vl_mff_map *vl_mff_map,
                         uint64_t *tlv_bitmap, struct ofpbuf *ofpacts)
  {
      struct ofpbuf b = ofpbuf_const_initializer(oasf, ntohs(oasf->len));
      ofpbuf_pull(&b, OBJECT_OFFSETOF(oasf, pad));
  
      union mf_value value, mask;
      const struct mf_field *field;
      enum ofperr error;
      error  = mf_vl_mff_nx_pull_entry(&b, vl_mff_map, &field, &value,
                                       may_mask ? &mask : NULL, tlv_bitmap);
      if (error) {
          return (error == OFPERR_OFPBMC_BAD_MASK
                  ? OFPERR_OFPBAC_BAD_SET_MASK
                  : error);
      }
  
      if (!may_mask) {
          memset(&mask, 0xff, field->n_bytes);
      }
  
      if (!is_all_zeros(b.data, b.size)) {
          return OFPERR_OFPBAC_BAD_SET_ARGUMENT;
      }
  
      /* OpenFlow says specifically that one may not set OXM_OF_IN_PORT via
       * Set-Field. */
      if (field->id == MFF_IN_PORT_OXM) {
          return OFPERR_OFPBAC_BAD_SET_ARGUMENT;
      }
  
      /* oxm_length is now validated to be compatible with mf_value. */
      if (!field->writable) {
          VLOG_WARN_RL(&rl, "destination field %s is not writable",
                       field->name);
          return OFPERR_OFPBAC_BAD_SET_ARGUMENT;
      }
  
      /* The value must be valid for match.  OpenFlow 1.5 also says,
       * "In an OXM_OF_VLAN_VID set-field action, the OFPVID_PRESENT bit must be
       * a 1-bit in oxm_value and in oxm_mask." */
      if (!mf_is_value_valid(field, &value)
          || (field->id == MFF_VLAN_VID
              && (!(mask.be16 & htons(OFPVID12_PRESENT))
                  || !(value.be16 & htons(OFPVID12_PRESENT))))) {
          struct ds ds = DS_EMPTY_INITIALIZER;
          mf_format(field, &value, NULL, NULL, &ds);
          VLOG_WARN_RL(&rl, "Invalid value for set field %s: %s",
                       field->name, ds_cstr(&ds));
          ds_destroy(&ds);
  
          return OFPERR_OFPBAC_BAD_SET_ARGUMENT;
      }
  
      ofpact_put_set_field(ofpacts, field, &value, &mask);
      return 0;
  }
  
  static enum ofperr
  decode_OFPAT_RAW12_SET_FIELD(const struct ofp12_action_set_field *oasf,
                               enum ofp_version ofp_version OVS_UNUSED,
                               const struct vl_mff_map *vl_mff_map,
                               uint64_t *tlv_bitmap, struct ofpbuf *ofpacts)
  {
      return decode_ofpat_set_field(oasf, false, vl_mff_map, tlv_bitmap,
                                    ofpacts);
  }
  
  static enum ofperr
  decode_OFPAT_RAW15_SET_FIELD(const struct ofp12_action_set_field *oasf,
                               enum ofp_version ofp_version OVS_UNUSED,
                               const struct vl_mff_map *vl_mff_map,
                               uint64_t *tlv_bitmap, struct ofpbuf *ofpacts)
  {
      return decode_ofpat_set_field(oasf, true, vl_mff_map, tlv_bitmap, ofpacts);
  }
  
  static enum ofperr
  decode_NXAST_RAW_REG_LOAD(const struct nx_action_reg_load *narl,
                            enum ofp_version ofp_version OVS_UNUSED,
                            const struct vl_mff_map *vl_mff_map,
                            uint64_t *tlv_bitmap, struct ofpbuf *out)
  {
      struct mf_subfield dst;
      enum ofperr error;
  
      dst.ofs = nxm_decode_ofs(narl->ofs_nbits);
      dst.n_bits = nxm_decode_n_bits(narl->ofs_nbits);
      error = mf_vl_mff_mf_from_nxm_header(ntohl(narl->dst), vl_mff_map,
                                           &dst.field, tlv_bitmap);
      if (error) {
          return error;
      }
  
      error = mf_check_dst(&dst, NULL);
      if (error) {
          return error;
      }
  
      /* Reject 'narl' if a bit numbered 'n_bits' or higher is set to 1 in
       * narl->value. */
      if (dst.n_bits < 64 && ntohll(narl->value) >> dst.n_bits) {
          return OFPERR_OFPBAC_BAD_ARGUMENT;
      }
  
      struct ofpact_set_field *sf = ofpact_put_reg_load(out, dst.field, NULL,
                                                        NULL);
      bitwise_put(ntohll(narl->value),
                  sf->value, dst.field->n_bytes, dst.ofs,
                  dst.n_bits);
      bitwise_put(UINT64_MAX,
                  ofpact_set_field_mask(sf), dst.field->n_bytes, dst.ofs,
                  dst.n_bits);
      return 0;
  }
  
  static enum ofperr
  decode_NXAST_RAW_REG_LOAD2(const struct ext_action_header *eah,
                             enum ofp_version ofp_version OVS_UNUSED,
                             const struct vl_mff_map *vl_mff_map,
                             uint64_t *tlv_bitmap, struct ofpbuf *out)
  {
      struct ofpbuf b = ofpbuf_const_initializer(eah, ntohs(eah->len));
      ofpbuf_pull(&b, OBJECT_OFFSETOF(eah, pad));
  
      union mf_value value, mask;
      const struct mf_field *field;
      enum ofperr error;
      error = mf_vl_mff_nx_pull_entry(&b, vl_mff_map, &field, &value, &mask,
                                      tlv_bitmap);
      if (error) {
          return error;
      }
  
      if (!is_all_zeros(b.data, b.size)) {
          return OFPERR_OFPBAC_BAD_SET_ARGUMENT;
      }
  
      if (!field->writable) {
          VLOG_WARN_RL(&rl, "destination field %s is not writable", field->name);
          return OFPERR_OFPBAC_BAD_SET_ARGUMENT;
      }
  
      /* Put value and mask. */
      ofpact_put_reg_load2(out, field, &value, &mask);
      return 0;
  }
  
  static void
  put_set_field(struct ofpbuf *openflow, enum ofp_version ofp_version,
                enum mf_field_id field, uint64_t value_)
  {
      struct ofp12_action_set_field *oasf OVS_UNUSED;
      int n_bytes = mf_from_id(field)->n_bytes;
      size_t start_ofs = openflow->size;
      union mf_value value;
  
      value.be64 = htonll(value_ << (8 * (8 - n_bytes)));
  
      oasf = put_OFPAT12_SET_FIELD(openflow);
      openflow->size = openflow->size - sizeof oasf->pad;
      nx_put_entry(openflow, mf_from_id(field), ofp_version, &value, NULL);
      pad_ofpat(openflow, start_ofs);
  }
  
  static void
  put_reg_load(struct ofpbuf *openflow,
               const struct mf_subfield *dst, uint64_t value)
  {
      ovs_assert(dst->n_bits <= 64);
  
      struct nx_action_reg_load *narl = put_NXAST_REG_LOAD(openflow);
      narl->ofs_nbits = nxm_encode_ofs_nbits(dst->ofs, dst->n_bits);
      narl->dst = htonl(nxm_header_from_mff(dst->field));
      narl->value = htonll(value);
  }
  
  static bool
  next_load_segment(const struct ofpact_set_field *sf,
                    struct mf_subfield *dst, uint64_t *value)
  {
      int n_bits = sf->field->n_bits;
      int n_bytes = sf->field->n_bytes;
      int start = dst->ofs + dst->n_bits;
  
      if (start < n_bits) {
          dst->field = sf->field;
          dst->ofs = bitwise_scan(ofpact_set_field_mask(sf), n_bytes, 1, start,
                                  n_bits);
          if (dst->ofs < n_bits) {
              dst->n_bits = bitwise_scan(ofpact_set_field_mask(sf), n_bytes, 0,
                                         dst->ofs + 1,
                                         MIN(dst->ofs + 64, n_bits)) - dst->ofs;
              *value = bitwise_get(sf->value, n_bytes, dst->ofs, dst->n_bits);
              return true;
          }
      }
      return false;
  }
  
  /* Convert 'sf' to a series of REG_LOADs. */
  static void
  set_field_to_nxast(const struct ofpact_set_field *sf, struct ofpbuf *openflow)
  {
      /* If 'sf' cannot be encoded as NXAST_REG_LOAD because it requires an
       * experimenter OXM or is variable length (or if it came in as
       * NXAST_REG_LOAD2), encode as NXAST_REG_LOAD2.  Otherwise use
       * NXAST_REG_LOAD, which is backward compatible. */
      if (sf->ofpact.raw == NXAST_RAW_REG_LOAD2
          || !mf_nxm_header(sf->field->id) || sf->field->variable_len) {
          struct ext_action_header *eah OVS_UNUSED;
          size_t start_ofs = openflow->size;
  
          eah = put_NXAST_REG_LOAD2(openflow);
          openflow->size = openflow->size - sizeof eah->pad;
          nx_put_entry(openflow, sf->field, 0, sf->value,
                       ofpact_set_field_mask(sf));
          pad_ofpat(openflow, start_ofs);
      } else {
          struct mf_subfield dst;
          uint64_t value;
  
          dst.ofs = dst.n_bits = 0;
          while (next_load_segment(sf, &dst, &value)) {
              put_reg_load(openflow, &dst, value);
          }
      }
  }
  
  /* Convert 'sf', which must set an entire field, to standard OpenFlow 1.0/1.1
   * actions, if we can, falling back to Nicira extensions if we must.
   *
   * We check only meta-flow types that can appear within set field actions and
   * that have a mapping to compatible action types.  These struct mf_field
   * definitions have a defined OXM or NXM header value and specify the field as
   * writable. */
  static void
  set_field_to_legacy_openflow(const struct ofpact_set_field *sf,
                               enum ofp_version ofp_version,
                               struct ofpbuf *out)
  {
      switch ((int) sf->field->id) {
      case MFF_VLAN_TCI: {
          ovs_be16 tci = sf->value->be16;
          bool cfi = (tci & htons(VLAN_CFI)) != 0;
          uint16_t vid = vlan_tci_to_vid(tci);
          uint8_t pcp = vlan_tci_to_pcp(tci);
  
          if (ofp_version < OFP11_VERSION) {
              /* NXM_OF_VLAN_TCI to OpenFlow 1.0 mapping:
               *
               * If CFI=1, Add or modify VLAN VID & PCP.
               * If CFI=0, strip VLAN header, if any.
               */
              if (cfi) {
                  put_OFPAT10_SET_VLAN_VID(out, vid);
                  put_OFPAT10_SET_VLAN_PCP(out, pcp);
              } else {
                  put_OFPAT10_STRIP_VLAN(out);
              }
          } else {
              /* NXM_OF_VLAN_TCI to OpenFlow 1.1 mapping:
               *
               * If CFI=1, Add or modify VLAN VID & PCP.
               *    OpenFlow 1.1 set actions only apply if the packet
               *    already has VLAN tags.  To be sure that is the case
               *    we have to push a VLAN header.  As we do not support
               *    multiple layers of VLANs, this is a no-op, if a VLAN
               *    header already exists.  This may backfire, however,
               *    when we start supporting multiple layers of VLANs.
               * If CFI=0, strip VLAN header, if any.
               */
              if (cfi) {
                  /* Push a VLAN tag, if one was not seen at action validation
                   * time. */
                  if (!sf->flow_has_vlan) {
                      put_OFPAT11_PUSH_VLAN(out, htons(ETH_TYPE_VLAN_8021Q));
                  }
                  put_OFPAT11_SET_VLAN_VID(out, vid);
                  put_OFPAT11_SET_VLAN_PCP(out, pcp);
              } else {
                  /* If the flow did not match on vlan, we have no way of
                   * knowing if the vlan tag exists, so we must POP just to be
                   * sure. */
                  put_OFPAT11_POP_VLAN(out);
              }
          }
          break;
      }
  
      case MFF_VLAN_VID: {
          uint16_t vid = ntohs(sf->value->be16) & VLAN_VID_MASK;
          if (ofp_version == OFP10_VERSION) {
              put_OFPAT10_SET_VLAN_VID(out, vid);
          } else {
              put_OFPAT11_SET_VLAN_VID(out, vid);
          }
          break;
      }
  
      case MFF_VLAN_PCP:
          if (ofp_version == OFP10_VERSION) {
              put_OFPAT10_SET_VLAN_PCP(out, sf->value->u8);
          } else {
              put_OFPAT11_SET_VLAN_PCP(out, sf->value->u8);
          }
          break;
  
      case MFF_ETH_SRC:
          put_OFPAT_SET_DL_SRC(out, ofp_version)->dl_addr = sf->value->mac;
          break;
  
      case MFF_ETH_DST:
          put_OFPAT_SET_DL_DST(out, ofp_version)->dl_addr = sf->value->mac;
          break;
  
      case MFF_IPV4_SRC:
          put_OFPAT_SET_NW_SRC(out, ofp_version, sf->value->be32);
          break;
  
      case MFF_IPV4_DST:
          put_OFPAT_SET_NW_DST(out, ofp_version, sf->value->be32);
          break;
  
      case MFF_IP_DSCP:
          put_OFPAT_SET_NW_TOS(out, ofp_version, sf->value->u8);
          break;
  
      case MFF_IP_DSCP_SHIFTED:
          put_OFPAT_SET_NW_TOS(out, ofp_version, sf->value->u8 << 2);
          break;
  
      case MFF_IP_ECN: {
          struct ofpact_ecn ip_ecn = { .ecn = sf->value->u8 };
          encode_SET_IP_ECN(&ip_ecn, ofp_version, out);
          break;
      }
  
      case MFF_TCP_SRC:
      case MFF_UDP_SRC:
          put_OFPAT_SET_TP_SRC(out, sf->value->be16);
          break;
  
      case MFF_TCP_DST:
      case MFF_UDP_DST:
          put_OFPAT_SET_TP_DST(out, sf->value->be16);
          break;
  
      default:
          set_field_to_nxast(sf, out);
          break;
      }
  }
  
  static void
  set_field_to_set_field(const struct ofpact_set_field *sf,
                         enum ofp_version ofp_version, struct ofpbuf *out)
  {
      struct ofp12_action_set_field *oasf OVS_UNUSED;
      size_t start_ofs = out->size;
  
      oasf = put_OFPAT12_SET_FIELD(out);
      out->size = out->size - sizeof oasf->pad;
      nx_put_entry(out, sf->field, ofp_version, sf->value,
                   ofpact_set_field_mask(sf));
      pad_ofpat(out, start_ofs);
  }
  
  static void
  encode_SET_FIELD(const struct ofpact_set_field *sf,
                   enum ofp_version ofp_version, struct ofpbuf *out)
  {
      if (ofp_version >= OFP15_VERSION) {
          /* OF1.5+ only has Set-Field (reg_load is redundant so we drop it
           * entirely). */
          set_field_to_set_field(sf, ofp_version, out);
      } else if (sf->ofpact.raw == NXAST_RAW_REG_LOAD ||
                 sf->ofpact.raw == NXAST_RAW_REG_LOAD2) {
          /* It came in as reg_load, send it out the same way. */
          set_field_to_nxast(sf, out);
      } else if (ofp_version < OFP12_VERSION) {
          /* OpenFlow 1.0 and 1.1 don't have Set-Field. */
          set_field_to_legacy_openflow(sf, ofp_version, out);
      } else if (is_all_ones(ofpact_set_field_mask(sf), sf->field->n_bytes)) {
          /* We're encoding to OpenFlow 1.2, 1.3, or 1.4.  The action sets an
           * entire field, so encode it as OFPAT_SET_FIELD. */
          set_field_to_set_field(sf, ofp_version, out);
      } else {
          /* We're encoding to OpenFlow 1.2, 1.3, or 1.4.  The action cannot be
           * encoded as OFPAT_SET_FIELD because it does not set an entire field,
           * so encode it as reg_load. */
          set_field_to_nxast(sf, out);
      }
  }
  
  /* Parses the input argument 'arg' into the key, value, and delimiter
   * components that are common across the reg_load and set_field action format.
   *
   * With an argument like "1->metadata", sets the following pointers to
   * point within 'arg':
   * key: "metadata"
   * value: "1"
   * delim: "->"
   *
   * Returns NULL if successful, otherwise a malloc()'d string describing the
   * error.  The caller is responsible for freeing the returned string. */
  static char * OVS_WARN_UNUSED_RESULT
  set_field_split_str(char *arg, char **key, char **value, char **delim)
  {
      char *value_end;
  
      *value = arg;
      value_end = strstr(arg, "->");
      *key = value_end + strlen("->");
      if (delim) {
          *delim = value_end;
      }
  
      if (!value_end) {
          return xasprintf("%s: missing `->'", arg);
      }
      if (strlen(value_end) <= strlen("->")) {
          return xasprintf("%s: missing field name following `->'", arg);
      }
  
      return NULL;
  }
  
  /* Parses a "set_field" action with argument 'arg', appending the parsed
   * action to 'pp->ofpacts'.
   *
   * Returns NULL if successful, otherwise a malloc()'d string describing the
   * error.  The caller is responsible for freeing the returned string. */
  static char * OVS_WARN_UNUSED_RESULT
  set_field_parse__(char *arg, const struct ofpact_parse_params *pp)
  {
      char *value;
      char *delim;
      char *key;
      const struct mf_field *mf;
      union mf_value sf_value, sf_mask;
      char *error;
  
      error = set_field_split_str(arg, &key, &value, &delim);
      if (error) {
          return error;
      }
  
      mf = mf_from_name(key);
      if (!mf) {
          return xasprintf("%s is not a valid OXM field name", key);
      }
      if (!mf->writable) {
          return xasprintf("%s is read-only", key);
      }
  
      delim[0] = '\0';
      error = mf_parse(mf, value, pp->port_map, &sf_value, &sf_mask);
      if (error) {
          return error;
      }
  
      if (!mf_is_value_valid(mf, &sf_value)) {
          return xasprintf("%s is not a valid value for field %s", value, key);
      }
  
      *pp->usable_protocols &= mf->usable_protocols_exact;
  
      ofpact_put_set_field(pp->ofpacts, mf, &sf_value, &sf_mask);
      return NULL;
  }
  
  /* Parses 'arg' as the argument to a "set_field" action, and appends such an
   * action to 'pp->ofpacts'.
   *
   * Returns NULL if successful, otherwise a malloc()'d string describing the
   * error.  The caller is responsible for freeing the returned string. */
  static char * OVS_WARN_UNUSED_RESULT
  parse_SET_FIELD(const char *arg, const struct ofpact_parse_params *pp)
  {
      char *copy = xstrdup(arg);
      char *error = set_field_parse__(copy, pp);
      free(copy);
      return error;
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_reg_load(char *arg, const struct ofpact_parse_params *pp)
  {
      struct mf_subfield dst;
      char *key, *value_str;
      union mf_value value;
      char *error;
  
      error = set_field_split_str(arg, &key, &value_str, NULL);
      if (error) {
          return error;
      }
  
      error = mf_parse_subfield(&dst, key);
      if (error) {
          return error;
      }
  
      if (parse_int_string(value_str, (uint8_t *)&value, dst.field->n_bytes,
                           &key)) {
          return xasprintf("%s: cannot parse integer value", arg);
      }
  
      if (!bitwise_is_all_zeros(&value, dst.field->n_bytes, dst.n_bits,
                                dst.field->n_bytes * 8 - dst.n_bits)) {
          struct ds ds;
  
          ds_init(&ds);
          mf_format(dst.field, &value, NULL, NULL, &ds);
          error = xasprintf("%s: value %s does not fit into %d bits",
                            arg, ds_cstr(&ds), dst.n_bits);
          ds_destroy(&ds);
          return error;
      }
  
      struct ofpact_set_field *sf = ofpact_put_reg_load(pp->ofpacts, dst.field,
                                                        NULL, NULL);
  
      bitwise_copy(&value, dst.field->n_bytes, 0, sf->value,
                   dst.field->n_bytes, dst.ofs, dst.n_bits);
      bitwise_one(ofpact_set_field_mask(sf), dst.field->n_bytes, dst.ofs,
                  dst.n_bits);
      return NULL;
  }
  
  static void
  format_SET_FIELD(const struct ofpact_set_field *a,
                   const struct ofpact_format_params *fp)
  {
      if (a->ofpact.raw == NXAST_RAW_REG_LOAD) {
          struct mf_subfield dst;
          uint64_t value;
  
          dst.ofs = dst.n_bits = 0;
          while (next_load_segment(a, &dst, &value)) {
              ds_put_format(fp->s, "%sload:%s%#"PRIx64"%s->%s",
                            colors.special, colors.end, value,
                            colors.special, colors.end);
              mf_format_subfield(&dst, fp->s);
              ds_put_char(fp->s, ',');
          }
          ds_chomp(fp->s, ',');
      } else {
          ds_put_format(fp->s, "%sset_field:%s", colors.special, colors.end);
          mf_format(a->field, a->value, ofpact_set_field_mask(a),
                    fp->port_map, fp->s);
          ds_put_format(fp->s, "%s->%s%s",
                        colors.special, colors.end, a->field->name);
      }
  }
  
  static enum ofperr
  check_SET_FIELD(struct ofpact_set_field *a,
                  const struct ofpact_check_params *cp)
  {
      const struct mf_field *mf = a->field;
      struct flow *flow = &cp->match->flow;
      ovs_be16 *tci = &flow->vlans[0].tci;
  
      /* Require OXM_OF_VLAN_VID to have an existing VLAN header. */
      if (!mf_are_prereqs_ok(mf, flow, NULL)
          || (mf->id == MFF_VLAN_VID && !(*tci & htons(VLAN_CFI)))) {
          VLOG_WARN_RL(&rl, "set_field %s lacks correct prerequisites",
                       mf->name);
          return OFPERR_OFPBAC_MATCH_INCONSISTENT;
      }
  
      /* Remember if we saw a VLAN tag in the flow, to aid translating to
       * OpenFlow 1.1 if need be. */
      a->flow_has_vlan = (*tci & htons(VLAN_CFI)) != 0;
      if (mf->id == MFF_VLAN_TCI) {
          /* The set field may add or remove the VLAN tag,
           * Mark the status temporarily. */
          *tci = a->value->be16;
      }
  
      return 0;
  }
  
  /* Appends an OFPACT_SET_FIELD ofpact with enough space for the value and mask
   * for the 'field' to 'ofpacts' and returns it.  Fills in the value from
   * 'value', if non-NULL, and mask from 'mask' if non-NULL.  If 'value' is
   * non-NULL and 'mask' is NULL, an all-ones mask will be filled in. */
  struct ofpact_set_field *
  ofpact_put_set_field(struct ofpbuf *ofpacts, const struct mf_field *field,
                       const void *value, const void *mask)
  {
      struct ofpact_set_field *sf = ofpact_put_SET_FIELD(ofpacts);
      sf->field = field;
  
      /* Fill in the value and mask if given, otherwise put zeroes so that the
       * caller may fill in the value and mask itself. */
      if (value) {
          ofpbuf_put_uninit(ofpacts, 2 * field->n_bytes);
          sf = ofpacts->header;
          memcpy(sf->value, value, field->n_bytes);
          if (mask) {
              memcpy(ofpact_set_field_mask(sf), mask, field->n_bytes);
          } else {
              memset(ofpact_set_field_mask(sf), 0xff, field->n_bytes);
          }
      } else {
          ofpbuf_put_zeros(ofpacts, 2 * field->n_bytes);
          sf = ofpacts->header;
      }
      /* Update length. */
      ofpact_finish_SET_FIELD(ofpacts, &sf);
  
      return sf;
  }
  
  /* Appends an OFPACT_SET_FIELD ofpact to 'ofpacts' and returns it.  The ofpact
   * is marked such that, if possible, it will be translated to OpenFlow as
   * NXAST_REG_LOAD extension actions rather than OFPAT_SET_FIELD, either because
   * that was the way that the action was expressed when it came into OVS or for
   * backward compatibility. */
  struct ofpact_set_field *
  ofpact_put_reg_load(struct ofpbuf *ofpacts, const struct mf_field *field,
                      const void *value, const void *mask)
  {
      struct ofpact_set_field *sf = ofpact_put_set_field(ofpacts, field, value,
                                                         mask);
      sf->ofpact.raw = NXAST_RAW_REG_LOAD;
  
      return sf;
  }
  
  struct ofpact_set_field *
  ofpact_put_reg_load2(struct ofpbuf *ofpacts, const struct mf_field *field,
                       const void *value, const void *mask)
  {
      struct ofpact_set_field *sf = ofpact_put_set_field(ofpacts, field, value,
                                                         mask);
      sf->ofpact.raw = NXAST_RAW_REG_LOAD2;
  
      return sf;
  }
  
  
  /* Action structure for NXAST_STACK_PUSH and NXAST_STACK_POP.
   *
   * Pushes (or pops) field[offset: offset + n_bits] to (or from)
   * top of the stack.
   */
  struct nx_action_stack {
      ovs_be16 type;                  /* OFPAT_VENDOR. */
      ovs_be16 len;                   /* Length is 16. */
      ovs_be32 vendor;                /* NX_VENDOR_ID. */
      ovs_be16 subtype;               /* NXAST_STACK_PUSH or NXAST_STACK_POP. */
      ovs_be16 offset;                /* Bit offset into the field. */
      /* Followed by:
       * - OXM/NXM header for field to push or pop (4 or 8 bytes).
       * - ovs_be16 'n_bits', the number of bits to extract from the field.
       * - Enough 0-bytes to pad out the action to 24 bytes. */
      uint8_t pad[12];                /* See above. */
  };
  OFP_ASSERT(sizeof(struct nx_action_stack) == 24);
  
  static enum ofperr
  decode_stack_action(const struct nx_action_stack *nasp,
                      const struct vl_mff_map *vl_mff_map, uint64_t *tlv_bitmap,
                      struct ofpact_stack *stack_action)
  {
      enum ofperr error;
      stack_action->subfield.ofs = ntohs(nasp->offset);
  
      struct ofpbuf b = ofpbuf_const_initializer(nasp, sizeof *nasp);
      ofpbuf_pull(&b, OBJECT_OFFSETOF(nasp, pad));
      error  = mf_vl_mff_nx_pull_header(&b, vl_mff_map,
                                        &stack_action->subfield.field, NULL,
                                        tlv_bitmap);
      if (error) {
          return error;
      }
  
      stack_action->subfield.n_bits = ntohs(*(const ovs_be16 *) b.data);
      ofpbuf_pull(&b, 2);
      if (!is_all_zeros(b.data, b.size)) {
          return OFPERR_NXBRC_MUST_BE_ZERO;
      }
  
      return 0;
  }
  
  static enum ofperr
  decode_NXAST_RAW_STACK_PUSH(const struct nx_action_stack *nasp,
                              enum ofp_version ofp_version OVS_UNUSED,
                              const struct vl_mff_map *vl_mff_map,
                              uint64_t *tlv_bitmap, struct ofpbuf *ofpacts)
  {
      struct ofpact_stack *push = ofpact_put_STACK_PUSH(ofpacts);
      enum ofperr error = decode_stack_action(nasp, vl_mff_map, tlv_bitmap,
                                              push);
      return error ? error : nxm_stack_push_check(push, NULL);
  }
  
  static enum ofperr
  decode_NXAST_RAW_STACK_POP(const struct nx_action_stack *nasp,
                             enum ofp_version ofp_version OVS_UNUSED,
                             const struct vl_mff_map *vl_mff_map,
                             uint64_t *tlv_bitmap, struct ofpbuf *ofpacts)
  {
      struct ofpact_stack *pop = ofpact_put_STACK_POP(ofpacts);
      enum ofperr error = decode_stack_action(nasp, vl_mff_map, tlv_bitmap,
                                              pop);
      return error ? error : nxm_stack_pop_check(pop, NULL);
  }
  
  static void
  encode_STACK_op(const struct ofpact_stack *stack_action,
                  struct nx_action_stack *nasp)
  {
      struct ofpbuf b;
      ovs_be16 n_bits;
  
      nasp->offset = htons(stack_action->subfield.ofs);
  
      ofpbuf_use_stack(&b, nasp, ntohs(nasp->len));
      ofpbuf_put_uninit(&b, OBJECT_OFFSETOF(nasp, pad));
      nx_put_mff_header(&b, stack_action->subfield.field, 0, false);
      n_bits = htons(stack_action->subfield.n_bits);
      ofpbuf_put(&b, &n_bits, sizeof n_bits);
  }
  
  static void
  encode_STACK_PUSH(const struct ofpact_stack *stack,
                    enum ofp_version ofp_version OVS_UNUSED, struct ofpbuf *out)
  {
      encode_STACK_op(stack, put_NXAST_STACK_PUSH(out));
  }
  
  static void
  encode_STACK_POP(const struct ofpact_stack *stack,
                   enum ofp_version ofp_version OVS_UNUSED, struct ofpbuf *out)
  {
      encode_STACK_op(stack, put_NXAST_STACK_POP(out));
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_STACK_PUSH(char *arg, const struct ofpact_parse_params *pp)
  {
      return nxm_parse_stack_action(ofpact_put_STACK_PUSH(pp->ofpacts), arg);
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_STACK_POP(char *arg, const struct ofpact_parse_params *pp)
  {
      return nxm_parse_stack_action(ofpact_put_STACK_POP(pp->ofpacts), arg);
  }
  
  static void
  format_STACK_PUSH(const struct ofpact_stack *a,
                    const struct ofpact_format_params *fp)
  {
      nxm_format_stack_push(a, fp->s);
  }
  
  static void
  format_STACK_POP(const struct ofpact_stack *a,
                   const struct ofpact_format_params *fp)
  {
      nxm_format_stack_pop(a, fp->s);
  }
  
  static enum ofperr
  check_STACK_PUSH(const struct ofpact_stack *a,
                   const struct ofpact_check_params *cp)
  {
      return nxm_stack_push_check(a, cp->match);
  }
  
  static enum ofperr
  check_STACK_POP(const struct ofpact_stack *a,
                  const struct ofpact_check_params *cp)
  {
      return nxm_stack_pop_check(a, cp->match);
  }
  
  /* Action structure for NXAST_DEC_TTL_CNT_IDS.
   *
   * If the packet is not IPv4 or IPv6, does nothing.  For IPv4 or IPv6, if the
   * TTL or hop limit is at least 2, decrements it by 1.  Otherwise, if TTL or
   * hop limit is 0 or 1, sends a packet-in to the controllers with each of the
   * 'n_controllers' controller IDs specified in 'cnt_ids'.
   *
   * (This differs from NXAST_DEC_TTL in that for NXAST_DEC_TTL the packet-in is
   * sent only to controllers with id 0.)
   */
  struct nx_action_cnt_ids {
      ovs_be16 type;              /* OFPAT_VENDOR. */
      ovs_be16 len;               /* Length including slaves. */
      ovs_be32 vendor;            /* NX_VENDOR_ID. */
      ovs_be16 subtype;           /* NXAST_DEC_TTL_CNT_IDS. */
  
      ovs_be16 n_controllers;     /* Number of controllers. */
      uint8_t zeros[4];           /* Must be zero. */
  
      /* Followed by 1 or more controller ids.
       *
       * uint16_t cnt_ids[];        // Controller ids.
       * uint8_t pad[];           // Must be 0 to 8-byte align cnt_ids[].
       */
  };
  OFP_ASSERT(sizeof(struct nx_action_cnt_ids) == 16);
  
  static enum ofperr
  decode_OFPAT_RAW_DEC_NW_TTL(struct ofpbuf *out)
  {
      uint16_t id = 0;
      struct ofpact_cnt_ids *ids;
      enum ofperr error = 0;
  
      ids = ofpact_put_DEC_TTL(out);
      ids->n_controllers = 1;
      ofpbuf_put(out, &id, sizeof id);
      ids = out->header;
      ofpact_finish_DEC_TTL(out, &ids);
      return error;
  }
  
  static enum ofperr
  decode_NXAST_RAW_DEC_TTL_CNT_IDS(const struct nx_action_cnt_ids *nac_ids,
                                   enum ofp_version ofp_version OVS_UNUSED,
                                   struct ofpbuf *out)
  {
      struct ofpact_cnt_ids *ids;
      size_t ids_size;
      int i;
  
      ids = ofpact_put_DEC_TTL(out);
      ids->ofpact.raw = NXAST_RAW_DEC_TTL_CNT_IDS;
      ids->n_controllers = ntohs(nac_ids->n_controllers);
      ids_size = ntohs(nac_ids->len) - sizeof *nac_ids;
  
      if (!is_all_zeros(nac_ids->zeros, sizeof nac_ids->zeros)) {
          return OFPERR_NXBRC_MUST_BE_ZERO;
      }
  
      if (ids_size < ids->n_controllers * sizeof(ovs_be16)) {
          VLOG_WARN_RL(&rl, "Nicira action dec_ttl_cnt_ids only has %"PRIuSIZE" "
                       "bytes allocated for controller ids.  %"PRIuSIZE" bytes "
                       "are required for %u controllers.",
                       ids_size, ids->n_controllers * sizeof(ovs_be16),
                       ids->n_controllers);
          return OFPERR_OFPBAC_BAD_LEN;
      }
  
      for (i = 0; i < ids->n_controllers; i++) {
          uint16_t id = ntohs(((ovs_be16 *)(nac_ids + 1))[i]);
          ofpbuf_put(out, &id, sizeof id);
          ids = out->header;
      }
  
      ofpact_finish_DEC_TTL(out, &ids);
  
      return 0;
  }
  
  static void
  encode_DEC_TTL(const struct ofpact_cnt_ids *dec_ttl,
                 enum ofp_version ofp_version, struct ofpbuf *out)
  {
      if (dec_ttl->ofpact.raw == NXAST_RAW_DEC_TTL_CNT_IDS
          || dec_ttl->n_controllers != 1
          || dec_ttl->cnt_ids[0] != 0) {
          struct nx_action_cnt_ids *nac_ids = put_NXAST_DEC_TTL_CNT_IDS(out);
          int ids_len = ROUND_UP(2 * dec_ttl->n_controllers, OFP_ACTION_ALIGN);
          ovs_be16 *ids;
          size_t i;
  
          nac_ids->len = htons(ntohs(nac_ids->len) + ids_len);
          nac_ids->n_controllers = htons(dec_ttl->n_controllers);
  
          ids = ofpbuf_put_zeros(out, ids_len);
          for (i = 0; i < dec_ttl->n_controllers; i++) {
              ids[i] = htons(dec_ttl->cnt_ids[i]);
          }
      } else {
          put_OFPAT_DEC_NW_TTL(out, ofp_version);
      }
  }
  
  static void
  parse_noargs_dec_ttl(const struct ofpact_parse_params *pp)
  {
      struct ofpact_cnt_ids *ids;
      uint16_t id = 0;
  
      ofpact_put_DEC_TTL(pp->ofpacts);
      ofpbuf_put(pp->ofpacts, &id, sizeof id);
      ids = pp->ofpacts->header;
      ids->n_controllers++;
      ofpact_finish_DEC_TTL(pp->ofpacts, &ids);
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_DEC_TTL(char *arg, const struct ofpact_parse_params *pp)
  {
      if (*arg == '\0') {
          parse_noargs_dec_ttl(pp);
      } else {
          struct ofpact_cnt_ids *ids;
          char *cntr;
  
          ids = ofpact_put_DEC_TTL(pp->ofpacts);
          ids->ofpact.raw = NXAST_RAW_DEC_TTL_CNT_IDS;
          for (cntr = strtok_r(arg, ", ", &arg); cntr != NULL;
               cntr = strtok_r(NULL, ", ", &arg)) {
              uint16_t id = atoi(cntr);
  
              ofpbuf_put(pp->ofpacts, &id, sizeof id);
              ids = pp->ofpacts->header;
              ids->n_controllers++;
          }
          if (!ids->n_controllers) {
              return xstrdup("dec_ttl_cnt_ids: expected at least one controller "
                             "id.");
          }
          ofpact_finish_DEC_TTL(pp->ofpacts, &ids);
      }
      return NULL;
  }
  
  static void
  format_DEC_TTL(const struct ofpact_cnt_ids *a,
                 const struct ofpact_format_params *fp)
  {
      size_t i;
  
      ds_put_format(fp->s, "%sdec_ttl%s", colors.paren, colors.end);
      if (a->ofpact.raw == NXAST_RAW_DEC_TTL_CNT_IDS) {
          ds_put_format(fp->s, "%s(%s", colors.paren, colors.end);
          for (i = 0; i < a->n_controllers; i++) {
              if (i) {
                  ds_put_cstr(fp->s, ",");
              }
              ds_put_format(fp->s, "%"PRIu16, a->cnt_ids[i]);
          }
          ds_put_format(fp->s, "%s)%s", colors.paren, colors.end);
      }
  }
  
  static enum ofperr
  check_DEC_TTL(const struct ofpact_cnt_ids *a OVS_UNUSED,
                struct ofpact_check_params *cp)
  {
      return check_set_ip(cp);
  }
  
  /* Set MPLS label actions. */
  
  static enum ofperr
  decode_OFPAT_RAW_SET_MPLS_LABEL(ovs_be32 label,
                                  enum ofp_version ofp_version OVS_UNUSED,
                                  struct ofpbuf *out)
  {
      ofpact_put_SET_MPLS_LABEL(out)->label = label;
      return 0;
  }
  
  static void
  encode_SET_MPLS_LABEL(const struct ofpact_mpls_label *label,
                        enum ofp_version ofp_version,
                                    struct ofpbuf *out)
  {
      if (ofp_version < OFP12_VERSION) {
          put_OFPAT_SET_MPLS_LABEL(out, ofp_version, label->label);
      } else {
          put_set_field(out, ofp_version, MFF_MPLS_LABEL, ntohl(label->label));
      }
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_SET_MPLS_LABEL(char *arg, const struct ofpact_parse_params *pp)
  {
      struct ofpact_mpls_label *mpls_label
          = ofpact_put_SET_MPLS_LABEL(pp->ofpacts);
      if (*arg == '\0') {
          return xstrdup("set_mpls_label: expected label.");
      }
  
      mpls_label->label = htonl(atoi(arg));
      return NULL;
  }
  
  static void
  format_SET_MPLS_LABEL(const struct ofpact_mpls_label *a,
                        const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%sset_mpls_label(%s%"PRIu32"%s)%s",
                    colors.paren, colors.end, ntohl(a->label),
                    colors.paren, colors.end);
  }
  
  static enum ofperr
  check_set_mpls(struct ofpact_check_params *cp)
  {
      ovs_be16 dl_type = get_dl_type(&cp->match->flow);
      if (!eth_type_mpls(dl_type)) {
          inconsistent_match(&cp->usable_protocols);
      }
      return 0;
  }
  
  static enum ofperr
  check_SET_MPLS_LABEL(const struct ofpact_mpls_label *a OVS_UNUSED,
                       struct ofpact_check_params *cp)
  {
      return check_set_mpls(cp);
  }
  
  /* Set MPLS TC actions. */
  
  static enum ofperr
  decode_OFPAT_RAW_SET_MPLS_TC(uint8_t tc,
                               enum ofp_version ofp_version OVS_UNUSED,
                               struct ofpbuf *out)
  {
      ofpact_put_SET_MPLS_TC(out)->tc = tc;
      return 0;
  }
  
  static void
  encode_SET_MPLS_TC(const struct ofpact_mpls_tc *tc,
                     enum ofp_version ofp_version, struct ofpbuf *out)
  {
      if (ofp_version < OFP12_VERSION) {
          put_OFPAT_SET_MPLS_TC(out, ofp_version, tc->tc);
      } else {
          put_set_field(out, ofp_version, MFF_MPLS_TC, tc->tc);
      }
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_SET_MPLS_TC(char *arg, const struct ofpact_parse_params *pp)
  {
      struct ofpact_mpls_tc *mpls_tc = ofpact_put_SET_MPLS_TC(pp->ofpacts);
  
      if (*arg == '\0') {
          return xstrdup("set_mpls_tc: expected tc.");
      }
  
      mpls_tc->tc = atoi(arg);
      return NULL;
  }
  
  static void
  format_SET_MPLS_TC(const struct ofpact_mpls_tc *a,
                     const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%sset_mpls_ttl(%s%"PRIu8"%s)%s",
                    colors.paren, colors.end, a->tc,
                    colors.paren, colors.end);
  }
  
  static enum ofperr
  check_SET_MPLS_TC(const struct ofpact_mpls_tc *a OVS_UNUSED,
                    struct ofpact_check_params *cp)
  {
      return check_set_mpls(cp);
  }
  
  /* Set MPLS TTL actions. */
  
  static enum ofperr
  decode_OFPAT_RAW_SET_MPLS_TTL(uint8_t ttl,
                                enum ofp_version ofp_version OVS_UNUSED,
                                struct ofpbuf *out)
  {
      ofpact_put_SET_MPLS_TTL(out)->ttl = ttl;
      return 0;
  }
  
  static void
  encode_SET_MPLS_TTL(const struct ofpact_mpls_ttl *ttl,
                      enum ofp_version ofp_version, struct ofpbuf *out)
  {
      put_OFPAT_SET_MPLS_TTL(out, ofp_version, ttl->ttl);
  }
  
  /* Parses 'arg' as the argument to a "set_mpls_ttl" action, and appends such an
   * action to 'pp->ofpacts'.
   *
   * Returns NULL if successful, otherwise a malloc()'d string describing the
   * error.  The caller is responsible for freeing the returned string. */
  static char * OVS_WARN_UNUSED_RESULT
  parse_SET_MPLS_TTL(char *arg, const struct ofpact_parse_params *pp)
  {
      struct ofpact_mpls_ttl *mpls_ttl = ofpact_put_SET_MPLS_TTL(pp->ofpacts);
  
      if (*arg == '\0') {
          return xstrdup("set_mpls_ttl: expected ttl.");
      }
  
      mpls_ttl->ttl = atoi(arg);
      return NULL;
  }
  
  static void
  format_SET_MPLS_TTL(const struct ofpact_mpls_ttl *a,
                      const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%sset_mpls_ttl(%s%"PRIu8"%s)%s",
                    colors.paren, colors.end, a->ttl,
                    colors.paren, colors.end);
  }
  
  static enum ofperr
  check_SET_MPLS_TTL(const struct ofpact_mpls_ttl *a OVS_UNUSED,
                     struct ofpact_check_params *cp)
  {
      return check_set_mpls(cp);
  }
  
  /* Decrement MPLS TTL actions. */
  
  static enum ofperr
  decode_OFPAT_RAW_DEC_MPLS_TTL(struct ofpbuf *out)
  {
      ofpact_put_DEC_MPLS_TTL(out);
      return 0;
  }
  
  static void
  encode_DEC_MPLS_TTL(const struct ofpact_null *null OVS_UNUSED,
                      enum ofp_version ofp_version, struct ofpbuf *out)
  {
      put_OFPAT_DEC_MPLS_TTL(out, ofp_version);
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_DEC_MPLS_TTL(char *arg OVS_UNUSED, const struct ofpact_parse_params *pp)
  {
      ofpact_put_DEC_MPLS_TTL(pp->ofpacts);
      return NULL;
  }
  
  static void
  format_DEC_MPLS_TTL(const struct ofpact_null *a OVS_UNUSED,
                      const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%sdec_mpls_ttl%s", colors.value, colors.end);
  }
  
  static enum ofperr
  check_DEC_MPLS_TTL(const struct ofpact_null *a OVS_UNUSED,
                     struct ofpact_check_params *cp)
  {
      return check_set_mpls(cp);
  }
  
  /* Push MPLS label action. */
  
  static enum ofperr
  decode_OFPAT_RAW_PUSH_MPLS(ovs_be16 ethertype,
                             enum ofp_version ofp_version OVS_UNUSED,
                             struct ofpbuf *out)
  {
      struct ofpact_push_mpls *oam;
  
      if (!eth_type_mpls(ethertype)) {
          return OFPERR_OFPBAC_BAD_ARGUMENT;
      }
      oam = ofpact_put_PUSH_MPLS(out);
      oam->ethertype = ethertype;
  
      return 0;
  }
  
  static void
  encode_PUSH_MPLS(const struct ofpact_push_mpls *push_mpls,
                   enum ofp_version ofp_version, struct ofpbuf *out)
  {
      put_OFPAT_PUSH_MPLS(out, ofp_version, push_mpls->ethertype);
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_PUSH_MPLS(char *arg, const struct ofpact_parse_params *pp)
  {
      uint16_t ethertype;
      char *error;
  
      error = str_to_u16(arg, "push_mpls", &ethertype);
      if (!error) {
          ofpact_put_PUSH_MPLS(pp->ofpacts)->ethertype = htons(ethertype);
      }
      return error;
  }
  
  static void
  format_PUSH_MPLS(const struct ofpact_push_mpls *a,
                   const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%spush_mpls:%s0x%04"PRIx16,
                    colors.param, colors.end, ntohs(a->ethertype));
  }
  
  static enum ofperr
  check_PUSH_MPLS(const struct ofpact_push_mpls *a,
                  struct ofpact_check_params *cp)
  {
      struct flow *flow = &cp->match->flow;
  
      if (flow->packet_type != htonl(PT_ETH)) {
          inconsistent_match(&cp->usable_protocols);
      }
      flow->dl_type = a->ethertype;
  
      /* The packet is now MPLS and the MPLS payload is opaque.
       * Thus nothing can be assumed about the network protocol.
       * Temporarily mark that we have no nw_proto. */
      flow->nw_proto = 0;
  
      return 0;
  }
  
  /* Pop MPLS label action. */
  
  static enum ofperr
  decode_OFPAT_RAW_POP_MPLS(ovs_be16 ethertype,
                            enum ofp_version ofp_version OVS_UNUSED,
                            struct ofpbuf *out)
  {
      ofpact_put_POP_MPLS(out)->ethertype = ethertype;
      return 0;
  }
  
  static void
  encode_POP_MPLS(const struct ofpact_pop_mpls *pop_mpls,
                  enum ofp_version ofp_version, struct ofpbuf *out)
  {
      put_OFPAT_POP_MPLS(out, ofp_version, pop_mpls->ethertype);
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_POP_MPLS(char *arg, const struct ofpact_parse_params *pp)
  {
      uint16_t ethertype;
      char *error;
  
      error = str_to_u16(arg, "pop_mpls", &ethertype);
      if (!error) {
          ofpact_put_POP_MPLS(pp->ofpacts)->ethertype = htons(ethertype);
      }
      return error;
  }
  
  static void
  format_POP_MPLS(const struct ofpact_pop_mpls *a,
                  const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%spop_mpls:%s0x%04"PRIx16,
                    colors.param, colors.end, ntohs(a->ethertype));
  }
  
  static enum ofperr
  check_POP_MPLS(const struct ofpact_pop_mpls *a, struct ofpact_check_params *cp)
  {
      struct flow *flow = &cp->match->flow;
      ovs_be16 dl_type = get_dl_type(flow);
  
      if (flow->packet_type != htonl(PT_ETH) || !eth_type_mpls(dl_type)) {
          inconsistent_match(&cp->usable_protocols);
      }
      flow->dl_type = a->ethertype;
      return 0;
  }
  
  /* Set tunnel ID actions. */
  
  static enum ofperr
  decode_NXAST_RAW_SET_TUNNEL(uint32_t tun_id,
                              enum ofp_version ofp_version OVS_UNUSED,
                              struct ofpbuf *out)
  {
      struct ofpact_tunnel *tunnel = ofpact_put_SET_TUNNEL(out);
      tunnel->ofpact.raw = NXAST_RAW_SET_TUNNEL;
      tunnel->tun_id = tun_id;
      return 0;
  }
  
  static enum ofperr
  decode_NXAST_RAW_SET_TUNNEL64(uint64_t tun_id,
                                enum ofp_version ofp_version OVS_UNUSED,
                                struct ofpbuf *out)
  {
      struct ofpact_tunnel *tunnel = ofpact_put_SET_TUNNEL(out);
      tunnel->ofpact.raw = NXAST_RAW_SET_TUNNEL64;
      tunnel->tun_id = tun_id;
      return 0;
  }
  
  static void
  encode_SET_TUNNEL(const struct ofpact_tunnel *tunnel,
                    enum ofp_version ofp_version, struct ofpbuf *out)
  {
      uint64_t tun_id = tunnel->tun_id;
  
      if (ofp_version < OFP12_VERSION) {
          if (tun_id <= UINT32_MAX
              && tunnel->ofpact.raw != NXAST_RAW_SET_TUNNEL64) {
              put_NXAST_SET_TUNNEL(out, tun_id);
          } else {
              put_NXAST_SET_TUNNEL64(out, tun_id);
          }
      } else {
          put_set_field(out, ofp_version, MFF_TUN_ID, tun_id);
      }
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_set_tunnel(char *arg, enum ofp_raw_action_type raw,
                   const struct ofpact_parse_params *pp)
  {
      struct ofpact_tunnel *tunnel;
  
      tunnel = ofpact_put_SET_TUNNEL(pp->ofpacts);
      tunnel->ofpact.raw = raw;
      return str_to_u64(arg, &tunnel->tun_id);
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_SET_TUNNEL(char *arg, const struct ofpact_parse_params *pp)
  {
      return parse_set_tunnel(arg, NXAST_RAW_SET_TUNNEL, pp);
  }
  
  static void
  format_SET_TUNNEL(const struct ofpact_tunnel *a,
                    const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%sset_tunnel%s:%s%#"PRIx64, colors.param,
                    (a->tun_id > UINT32_MAX
                     || a->ofpact.raw == NXAST_RAW_SET_TUNNEL64 ? "64" : ""),
                    colors.end, a->tun_id);
  }
  
  static enum ofperr
  check_SET_TUNNEL(const struct ofpact_tunnel *a OVS_UNUSED,
                   const struct ofpact_check_params *cp OVS_UNUSED)
  {
      return 0;
  }
  
  /* Set queue action. */
  
  static enum ofperr
  decode_OFPAT_RAW_SET_QUEUE(uint32_t queue_id,
                             enum ofp_version ofp_version OVS_UNUSED,
                             struct ofpbuf *out)
  {
      ofpact_put_SET_QUEUE(out)->queue_id = queue_id;
      return 0;
  }
  
  static void
  encode_SET_QUEUE(const struct ofpact_queue *queue,
                   enum ofp_version ofp_version, struct ofpbuf *out)
  {
      put_OFPAT_SET_QUEUE(out, ofp_version, queue->queue_id);
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_SET_QUEUE(char *arg, const struct ofpact_parse_params *pp)
  {
      return str_to_u32(arg, &ofpact_put_SET_QUEUE(pp->ofpacts)->queue_id);
  }
  
  static void
  format_SET_QUEUE(const struct ofpact_queue *a,
                   const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%sset_queue:%s%"PRIu32,
                    colors.param, colors.end, a->queue_id);
  }
  
  static enum ofperr
  check_SET_QUEUE(const struct ofpact_queue *a OVS_UNUSED,
                  const struct ofpact_check_params *cp OVS_UNUSED)
  {
      return 0;
  }
  
  /* Pop queue action. */
  
  static enum ofperr
  decode_NXAST_RAW_POP_QUEUE(struct ofpbuf *out)
  {
      ofpact_put_POP_QUEUE(out);
      return 0;
  }
  
  static void
  encode_POP_QUEUE(const struct ofpact_null *null OVS_UNUSED,
                   enum ofp_version ofp_version OVS_UNUSED, struct ofpbuf *out)
  {
      put_NXAST_POP_QUEUE(out);
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_POP_QUEUE(const char *arg OVS_UNUSED,
                  const struct ofpact_parse_params *pp)
  {
      ofpact_put_POP_QUEUE(pp->ofpacts);
      return NULL;
  }
  
  static void
  format_POP_QUEUE(const struct ofpact_null *a OVS_UNUSED,
                   const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%spop_queue%s", colors.value, colors.end);
  }
  
  static enum ofperr
  check_POP_QUEUE(const struct ofpact_null *a OVS_UNUSED,
                  const struct ofpact_check_params *cp OVS_UNUSED)
  {
      return 0;
  }
  
  /* Action structure for NXAST_FIN_TIMEOUT.
   *
   * This action changes the idle timeout or hard timeout, or both, of this
   * OpenFlow rule when the rule matches a TCP packet with the FIN or RST flag.
   * When such a packet is observed, the action reduces the rule's idle timeout
   * to 'fin_idle_timeout' and its hard timeout to 'fin_hard_timeout'.  This
   * action has no effect on an existing timeout that is already shorter than the
   * one that the action specifies.  A 'fin_idle_timeout' or 'fin_hard_timeout'
   * of zero has no effect on the respective timeout.
   *
   * 'fin_idle_timeout' and 'fin_hard_timeout' are measured in seconds.
   * 'fin_hard_timeout' specifies time since the flow's creation, not since the
   * receipt of the FIN or RST.
   *
   * This is useful for quickly discarding learned TCP flows that otherwise will
   * take a long time to expire.
   *
   * This action is intended for use with an OpenFlow rule that matches only a
   * single TCP flow.  If the rule matches multiple TCP flows (e.g. it wildcards
   * all TCP traffic, or all TCP traffic to a particular port), then any FIN or
   * RST in any of those flows will cause the entire OpenFlow rule to expire
   * early, which is not normally desirable.
   */
  struct nx_action_fin_timeout {
      ovs_be16 type;              /* OFPAT_VENDOR. */
      ovs_be16 len;               /* 16. */
      ovs_be32 vendor;            /* NX_VENDOR_ID. */
      ovs_be16 subtype;           /* NXAST_FIN_TIMEOUT. */
      ovs_be16 fin_idle_timeout;  /* New idle timeout, if nonzero. */
      ovs_be16 fin_hard_timeout;  /* New hard timeout, if nonzero. */
      ovs_be16 pad;               /* Must be zero. */
  };
  OFP_ASSERT(sizeof(struct nx_action_fin_timeout) == 16);
  
  static enum ofperr
  decode_NXAST_RAW_FIN_TIMEOUT(const struct nx_action_fin_timeout *naft,
                               enum ofp_version ofp_version OVS_UNUSED,
                               struct ofpbuf *out)
  {
      struct ofpact_fin_timeout *oft;
  
      oft = ofpact_put_FIN_TIMEOUT(out);
      oft->fin_idle_timeout = ntohs(naft->fin_idle_timeout);
      oft->fin_hard_timeout = ntohs(naft->fin_hard_timeout);
      return 0;
  }
  
  static void
  encode_FIN_TIMEOUT(const struct ofpact_fin_timeout *fin_timeout,
                     enum ofp_version ofp_version OVS_UNUSED,
                     struct ofpbuf *out)
  {
      struct nx_action_fin_timeout *naft = put_NXAST_FIN_TIMEOUT(out);
      naft->fin_idle_timeout = htons(fin_timeout->fin_idle_timeout);
      naft->fin_hard_timeout = htons(fin_timeout->fin_hard_timeout);
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_FIN_TIMEOUT(char *arg, const struct ofpact_parse_params *pp)
  {
      struct ofpact_fin_timeout *oft = ofpact_put_FIN_TIMEOUT(pp->ofpacts);
      char *key, *value;
  
      while (ofputil_parse_key_value(&arg, &key, &value)) {
          char *error;
  
          if (!strcmp(key, "idle_timeout")) {
              error =  str_to_u16(value, key, &oft->fin_idle_timeout);
          } else if (!strcmp(key, "hard_timeout")) {
              error = str_to_u16(value, key, &oft->fin_hard_timeout);
          } else {
              error = xasprintf("invalid key '%s' in 'fin_timeout' argument",
                                key);
          }
  
          if (error) {
              return error;
          }
      }
      return NULL;
  }
  
  static void
  format_FIN_TIMEOUT(const struct ofpact_fin_timeout *a,
                     const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%sfin_timeout(%s", colors.paren, colors.end);
      if (a->fin_idle_timeout) {
          ds_put_format(fp->s, "%sidle_timeout=%s%"PRIu16",",
                        colors.param, colors.end, a->fin_idle_timeout);
      }
      if (a->fin_hard_timeout) {
          ds_put_format(fp->s, "%shard_timeout=%s%"PRIu16",",
                        colors.param, colors.end, a->fin_hard_timeout);
      }
      ds_chomp(fp->s, ',');
      ds_put_format(fp->s, "%s)%s", colors.paren, colors.end);
  }
  
  
  static enum ofperr
  check_FIN_TIMEOUT(const struct ofpact_fin_timeout *a OVS_UNUSED,
                    struct ofpact_check_params *cp)
  {
      if (cp->match->flow.nw_proto != IPPROTO_TCP) {
          inconsistent_match(&cp->usable_protocols);
      }
      return 0;
  }
  
  /* Action structure for NXAST_ENCAP */
  struct nx_action_encap {
      ovs_be16 type;         /* OFPAT_VENDOR. */
      ovs_be16 len;          /* Total size including any property TLVs. */
      ovs_be32 vendor;       /* NX_VENDOR_ID. */
      ovs_be16 subtype;      /* NXAST_ENCAP. */
      ovs_be16 hdr_size;     /* Header size in bytes, 0 = 'not specified'.*/
      ovs_be32 new_pkt_type; /* Header type to add and PACKET_TYPE of result. */
      struct ofp_ed_prop_header props[];  /* Encap TLV properties. */
  };
  OFP_ASSERT(sizeof(struct nx_action_encap) == 16);
  
  static enum ofperr
  decode_NXAST_RAW_ENCAP(const struct nx_action_encap *nae,
                         enum ofp_version ofp_version OVS_UNUSED,
                         struct ofpbuf *out)
  {
      struct ofpact_encap *encap;
      const struct ofp_ed_prop_header *ofp_prop;
      size_t props_len;
      uint16_t n_props = 0;
      int err;
  
      encap = ofpact_put_ENCAP(out);
      encap->ofpact.raw = NXAST_RAW_ENCAP;
      switch (ntohl(nae->new_pkt_type)) {
      case PT_ETH:
      case PT_NSH:
          /* Add supported encap header types here. */
          break;
      default:
          return OFPERR_NXBAC_BAD_HEADER_TYPE;
      }
      encap->new_pkt_type = nae->new_pkt_type;
      encap->hdr_size = ntohs(nae->hdr_size);
  
      ofp_prop = nae->props;
      props_len = ntohs(nae->len) - offsetof(struct nx_action_encap, props);
      n_props = 0;
      while (props_len > 0) {
          err = decode_ed_prop(&ofp_prop, out, &props_len);
          if (err) {
              return err;
          }
          n_props++;
      }
      encap->n_props = n_props;
      out->header = &encap->ofpact;
      ofpact_finish_ENCAP(out, &encap);
  
      return 0;
  }
  
  static void
  encode_ENCAP(const struct ofpact_encap *encap,
               enum ofp_version ofp_version OVS_UNUSED,
               struct ofpbuf *out)
  {
      size_t start_ofs = out->size;
      struct nx_action_encap *nae = put_NXAST_ENCAP(out);
      int i;
  
      nae->new_pkt_type = encap->new_pkt_type;
      nae->hdr_size = htons(encap->hdr_size);
      const struct ofpact_ed_prop *prop = encap->props;
      for (i = 0; i < encap->n_props; i++) {
          encode_ed_prop(&prop, out);
      }
      pad_ofpat(out, start_ofs);
  }
  
  static bool
  parse_encap_header(const char *hdr, ovs_be32 *packet_type)
  {
      if (strcmp(hdr, "ethernet") == 0) {
          *packet_type = htonl(PT_ETH);
      } else if (strcmp(hdr, "nsh") == 0) {
          *packet_type = htonl(PT_NSH);
      } else {
          return false;
      }
      return true;
  }
  
  static char *
  parse_ed_props(const uint16_t prop_class, char **arg, int *n_props, struct ofpbuf *out)
  {
      char *key, *value, *err;
      uint8_t prop_type;
  
      while (ofputil_parse_key_value(arg, &key, &value)) {
          if (!parse_ed_prop_type(prop_class, key, &prop_type)) {
              return xasprintf("Invalid property: %s", key);
          }
          if (value == NULL) {
              return xasprintf("Missing the value for property: %s", key);
          }
          err = parse_ed_prop_value(prop_class, prop_type, value, out);
          if (err != NULL) {
              return err;
          }
          (*n_props)++;
      }
      return NULL;
  }
  
  /* The string representation of the encap action is
   * encap(header_type(prop=<value>,tlv(<class>,<type>,<value>),...))
   */
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_ENCAP(char *arg, const struct ofpact_parse_params *pp)
  {
      struct ofpact_encap *encap;
      char *key, *value, *str;
      char *error = NULL;
      uint16_t prop_class;
      int n_props = 0;
  
      encap = ofpact_put_ENCAP(pp->ofpacts);
      encap->hdr_size = 0;
      /* Parse encap header type. */
      str = arg;
      if (!ofputil_parse_key_value(&arg, &key, &value)) {
          return xasprintf("Missing encap hdr: %s", str);
      }
      if (!parse_encap_header(key, &encap->new_pkt_type)) {
          return xasprintf("Encap hdr not supported: %s", value);
      }
      if (!parse_ed_prop_class(key, &prop_class)) {
          return xasprintf("Invalid encap prop class: %s", key);
      }
      /* Parse encap properties. */
      error = parse_ed_props(prop_class, &value, &n_props, pp->ofpacts);
      if (error != NULL) {
          return error;
      }
      /* ofpbuf may have been re-allocated. */
      encap = pp->ofpacts->header;
      encap->n_props = n_props;
      ofpact_finish_ENCAP(pp->ofpacts, &encap);
      return NULL;
  }
  
  static char *
  format_encap_pkt_type(const ovs_be32 pkt_type)
  {
      switch (ntohl(pkt_type)) {
      case PT_ETH:
          return "ethernet";
      case PT_NSH:
          return "nsh";
      default:
          return "UNKNOWN";
      }
  }
  
  static void
  format_ed_props(struct ds *s, uint16_t n_props,
                  const struct ofpact_ed_prop *prop)
  {
      const uint8_t *p = (uint8_t *) prop;
      int i;
  
      if (n_props == 0) {
          return;
      }
      for (i = 0; i < n_props; i++) {
          format_ed_prop(s, prop);
          ds_put_char(s, ',');
          p += ROUND_UP(prop->len, 8);
          prop = ALIGNED_CAST(const struct ofpact_ed_prop *, p);
      }
      if (n_props > 0) {
          ds_chomp(s, ',');
      }
  }
  
  static void
  format_ENCAP(const struct ofpact_encap *a,
               const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%sencap(%s", colors.paren, colors.end);
      ds_put_format(fp->s, "%s", format_encap_pkt_type(a->new_pkt_type));
      if (a->n_props > 0) {
          ds_put_format(fp->s, "%s(%s", colors.paren, colors.end);
          format_ed_props(fp->s, a->n_props, a->props);
          ds_put_format(fp->s, "%s)%s", colors.paren, colors.end);
      }
      ds_put_format(fp->s, "%s)%s", colors.paren, colors.end);
  }
  
  static enum ofperr
  check_ENCAP(const struct ofpact_encap *a, struct ofpact_check_params *cp)
  {
      struct flow *flow = &cp->match->flow;
      flow->packet_type = a->new_pkt_type;
      if (pt_ns(flow->packet_type) == OFPHTN_ETHERTYPE) {
          flow->dl_type = htons(pt_ns_type(flow->packet_type));
      }
      if (!is_ip_any(flow)) {
          flow->nw_proto = 0;
      }
      return 0;
  }
  
  /* Action structure for NXAST_DECAP */
  struct nx_action_decap {
      ovs_be16 type;         /* OFPAT_VENDOR. */
      ovs_be16 len;          /* Total size including any property TLVs. */
      ovs_be32 vendor;       /* NX_VENDOR_ID. */
      ovs_be16 subtype;      /* NXAST_DECAP. */
      uint8_t pad[2];        /* 2 bytes padding */
  
      /* Packet type or result.
       *
       * The special value (0,0xFFFE) "Use next proto"
       * is used to request OVS to automatically set the new packet type based
       * on the decap'ed header's next protocol.
       */
      ovs_be32 new_pkt_type;
  };
  OFP_ASSERT(sizeof(struct nx_action_decap) == 16);
  
  static enum ofperr
  decode_NXAST_RAW_DECAP(const struct nx_action_decap *nad,
                         enum ofp_version ofp_version OVS_UNUSED,
                         struct ofpbuf *ofpacts)
  {
      struct ofpact_decap * decap;
  
      if (ntohs(nad->len) > sizeof *nad) {
          /* No properties supported yet. */
          return OFPERR_NXBAC_UNKNOWN_ED_PROP;
      }
  
      decap = ofpact_put_DECAP(ofpacts);
      decap->ofpact.raw = NXAST_RAW_DECAP;
      decap->new_pkt_type = nad->new_pkt_type;
      return 0;
  }
  
  static void
  encode_DECAP(const struct ofpact_decap *decap,
                  enum ofp_version ofp_version OVS_UNUSED, struct ofpbuf *out)
  {
      struct nx_action_decap *nad = put_NXAST_DECAP(out);
  
      nad->len = htons(sizeof(struct nx_action_decap));
      nad->new_pkt_type = decap->new_pkt_type;
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_DECAP(char *arg, const struct ofpact_parse_params *pp)
  {
      struct ofpact_decap *decap;
      char *key, *value, *pos;
      char *error = NULL;
      uint16_t ns, type;
  
      decap = ofpact_put_DECAP(pp->ofpacts);
      /* Default next packet_type is PT_USE_NEXT_PROTO. */
      decap->new_pkt_type = htonl(PT_USE_NEXT_PROTO);
  
      /* Parse decap packet_type if given. */
      if (ofputil_parse_key_value(&arg, &key, &value)) {
          if (strcmp(key, "packet_type") == 0) {
              pos = value;
              if (!ofputil_parse_key_value(&pos, &key, &value)
                  || strcmp(key, "ns") != 0) {
                  return xstrdup("Missing packet_type attribute ns");
              }
              error = str_to_u16(value, "ns", &ns);
              if (error) {
                  return error;
              }
              if (ns >= OFPHTN_N_TYPES) {
                  return xasprintf("Unsupported ns value: %"PRIu16, ns);
              }
              if (!ofputil_parse_key_value(&pos, &key, &value)
                  || strcmp(key, "type") != 0) {
                  return xstrdup("Missing packet_type attribute type");
              }
              error = str_to_u16(value, "type", &type);
              if (error) {
                  return error;
              }
              decap->new_pkt_type = htonl(PACKET_TYPE(ns, type));
          } else {
              return xasprintf("Invalid decap argument: %s", key);
          }
      }
      return NULL;
  }
  
  static void
  format_DECAP(const struct ofpact_decap *a,
               const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%sdecap(%s", colors.paren, colors.end);
      if (a->new_pkt_type != htonl(PT_USE_NEXT_PROTO)) {
          ds_put_format(fp->s, "packet_type(ns=%"PRIu16",id=%#"PRIx16")",
                        pt_ns(a->new_pkt_type),
                        pt_ns_type(a->new_pkt_type));
      }
      ds_put_format(fp->s, "%s)%s", colors.paren, colors.end);
  }
  
  static enum ofperr
  check_DECAP(const struct ofpact_decap *a OVS_UNUSED,
              struct ofpact_check_params *cp)
  {
      struct flow *flow = &cp->match->flow;
      if (flow->packet_type == htonl(PT_ETH)) {
          /* Adjust the packet_type to allow subsequent actions. */
          flow->packet_type = PACKET_TYPE_BE(OFPHTN_ETHERTYPE,
                                             ntohs(flow->dl_type));
      } else {
          /* The actual packet_type is only known after decapsulation.
           * Do not allow subsequent actions that depend on packet headers. */
          flow->packet_type = htonl(PT_UNKNOWN);
          flow->dl_type = OVS_BE16_MAX;
      }
      return 0;
  }
  
  /* Action dec_nsh_ttl */
  
  static enum ofperr
  decode_NXAST_RAW_DEC_NSH_TTL(struct ofpbuf *out)
  {
      ofpact_put_DEC_NSH_TTL(out);
      return 0;
  }
  
  static void
  encode_DEC_NSH_TTL(const struct ofpact_null *null OVS_UNUSED,
              enum ofp_version ofp_version OVS_UNUSED, struct ofpbuf *out)
  {
      put_NXAST_DEC_NSH_TTL(out);
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_DEC_NSH_TTL(char *arg OVS_UNUSED, const struct ofpact_parse_params *pp)
  {
      ofpact_put_DEC_NSH_TTL(pp->ofpacts);
      return NULL;
  }
  
  static void
  format_DEC_NSH_TTL(const struct ofpact_null *a OVS_UNUSED,
                     const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%sdec_nsh_ttl%s", colors.special, colors.end);
  }
  
  static enum ofperr
  check_DEC_NSH_TTL(const struct ofpact_null *a OVS_UNUSED,
                    struct ofpact_check_params *cp)
  {
      struct flow *flow = &cp->match->flow;
      if (flow->packet_type != htonl(PT_NSH) &&
          flow->dl_type != htons(ETH_TYPE_NSH)) {
          inconsistent_match(&cp->usable_protocols);
      }
      return 0;
  }
  
  /* Action structures for NXAST_RESUBMIT, NXAST_RESUBMIT_TABLE, and
   * NXAST_RESUBMIT_TABLE_CT.
   *
   * These actions search one of the switch's flow tables:
   *
   *    - For NXAST_RESUBMIT_TABLE and NXAST_RESUBMIT_TABLE_CT, if the
   *      'table' member is not 255, then it specifies the table to search.
   *
   *    - Otherwise (for NXAST_RESUBMIT_TABLE or NXAST_RESUBMIT_TABLE_CT with a
   *      'table' of 255, or for NXAST_RESUBMIT regardless of 'table'), it
   *      searches the current flow table, that is, the OpenFlow flow table that
   *      contains the flow from which this action was obtained.  If this action
   *      did not come from a flow table (e.g. it came from an OFPT_PACKET_OUT
   *      message), then table 0 is the current table.
   *
   * The flow table lookup uses a flow that may be slightly modified from the
   * original lookup:
   *
   *    - For NXAST_RESUBMIT, the 'in_port' member of struct nx_action_resubmit
   *      is used as the flow's in_port.
   *
   *    - For NXAST_RESUBMIT_TABLE and NXAST_RESUBMIT_TABLE_CT, if the 'in_port'
   *      member is not OFPP_IN_PORT, then its value is used as the flow's
   *      in_port.  Otherwise, the original in_port is used.
   *
   *    - For NXAST_RESUBMIT_TABLE_CT the Conntrack 5-tuple fields are used as
   *      the packets IP header fields during the lookup.
   *
   *    - If actions that modify the flow (e.g. OFPAT_SET_VLAN_VID) precede the
   *      resubmit action, then the flow is updated with the new values.
   *
   * Following the lookup, the original in_port is restored.
   *
   * If the modified flow matched in the flow table, then the corresponding
   * actions are executed.  Afterward, actions following the resubmit in the
   * original set of actions, if any, are executed; any changes made to the
   * packet (e.g. changes to VLAN) by secondary actions persist when those
   * actions are executed, although the original in_port is restored.
   *
   * Resubmit actions may be used any number of times within a set of actions.
   *
   * Resubmit actions may nest.  To prevent infinite loops and excessive resource
   * use, the implementation may limit nesting depth and the total number of
   * resubmits:
   *
   *    - Open vSwitch 1.0.1 and earlier did not support recursion.
   *
   *    - Open vSwitch 1.0.2 and 1.0.3 limited recursion to 8 levels.
   *
   *    - Open vSwitch 1.1 and 1.2 limited recursion to 16 levels.
   *
   *    - Open vSwitch 1.2 through 1.8 limited recursion to 32 levels.
   *
   *    - Open vSwitch 1.9 through 2.0 limited recursion to 64 levels.
   *
   *    - Open vSwitch 2.1 through 2.5 limited recursion to 64 levels and impose
   *      a total limit of 4,096 resubmits per flow translation (earlier versions
   *      did not impose any total limit).
   *
   * NXAST_RESUBMIT ignores 'table' and 'pad'.  NXAST_RESUBMIT_TABLE and
   * NXAST_RESUBMIT_TABLE_CT require 'pad' to be all-bits-zero.
   *
   * Open vSwitch 1.0.1 and earlier did not support recursion.  Open vSwitch
   * before 1.2.90 did not support NXAST_RESUBMIT_TABLE.  Open vSwitch before
   * 2.8.0 did not support NXAST_RESUBMIT_TABLE_CT.
   */
  struct nx_action_resubmit {
      ovs_be16 type;                  /* OFPAT_VENDOR. */
      ovs_be16 len;                   /* Length is 16. */
      ovs_be32 vendor;                /* NX_VENDOR_ID. */
      ovs_be16 subtype;               /* NXAST_RESUBMIT. */
      ovs_be16 in_port;               /* New in_port for checking flow table. */
      uint8_t table;                  /* NXAST_RESUBMIT_TABLE: table to use. */
      uint8_t pad[3];
  };
  OFP_ASSERT(sizeof(struct nx_action_resubmit) == 16);
  
  static enum ofperr
  decode_NXAST_RAW_RESUBMIT(uint16_t port,
                            enum ofp_version ofp_version OVS_UNUSED,
                            struct ofpbuf *out)
  {
      struct ofpact_resubmit *resubmit;
  
      resubmit = ofpact_put_RESUBMIT(out);
      resubmit->ofpact.raw = NXAST_RAW_RESUBMIT;
      resubmit->in_port = u16_to_ofp(port);
      resubmit->table_id = 0xff;
      return 0;
  }
  
  static enum ofperr
  decode_NXAST_RAW_RESUBMIT_TABLE(const struct nx_action_resubmit *nar,
                                  enum ofp_version ofp_version OVS_UNUSED,
                                  struct ofpbuf *out)
  {
      struct ofpact_resubmit *resubmit;
  
      if (nar->pad[0] || nar->pad[1] || nar->pad[2]) {
          return OFPERR_OFPBAC_BAD_ARGUMENT;
      }
  
      resubmit = ofpact_put_RESUBMIT(out);
      resubmit->ofpact.raw = NXAST_RAW_RESUBMIT_TABLE;
      resubmit->in_port = u16_to_ofp(ntohs(nar->in_port));
      resubmit->table_id = nar->table;
      return 0;
  }
  
  static enum ofperr
  decode_NXAST_RAW_RESUBMIT_TABLE_CT(const struct nx_action_resubmit *nar,
                                     enum ofp_version ofp_version OVS_UNUSED,
                                     struct ofpbuf *out)
  {
      enum ofperr error = decode_NXAST_RAW_RESUBMIT_TABLE(nar, ofp_version, out);
      if (error) {
          return error;
      }
      struct ofpact_resubmit *resubmit = out->header;
      resubmit->ofpact.raw = NXAST_RAW_RESUBMIT_TABLE_CT;
      resubmit->with_ct_orig = true;
      return 0;
  }
  
  static void
  encode_RESUBMIT(const struct ofpact_resubmit *resubmit,
                  enum ofp_version ofp_version OVS_UNUSED, struct ofpbuf *out)
  {
      uint16_t in_port = ofp_to_u16(resubmit->in_port);
  
      if (resubmit->table_id == 0xff
          && resubmit->ofpact.raw == NXAST_RAW_RESUBMIT) {
          put_NXAST_RESUBMIT(out, in_port);
      } else {
          struct nx_action_resubmit *nar;
          nar = resubmit->with_ct_orig
              ? put_NXAST_RESUBMIT_TABLE_CT(out) : put_NXAST_RESUBMIT_TABLE(out);
          nar->table = resubmit->table_id;
          nar->in_port = htons(in_port);
      }
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_RESUBMIT(char *arg, const struct ofpact_parse_params *pp)
  {
      struct ofpact_resubmit *resubmit;
      char *in_port_s, *table_s, *ct_s;
  
      resubmit = ofpact_put_RESUBMIT(pp->ofpacts);
  
      in_port_s = strsep(&arg, ",");
      if (in_port_s && in_port_s[0]) {
          if (!ofputil_port_from_string(in_port_s, pp->port_map,
                                        &resubmit->in_port)) {
              return xasprintf("%s: resubmit to unknown port", in_port_s);
          }
      } else {
          resubmit->in_port = OFPP_IN_PORT;
      }
  
      table_s = strsep(&arg, ",");
      if (table_s && table_s[0]) {
          if (!ofputil_table_from_string(table_s, pp->table_map,
                                         &resubmit->table_id)) {
              return xasprintf("%s: resubmit to unknown table", table_s);
          }
      } else {
          resubmit->table_id = 255;
      }
  
      ct_s = strsep(&arg, ",");
      if (ct_s && ct_s[0]) {
          if (strcmp(ct_s, "ct")) {
              return xasprintf("%s: unknown parameter", ct_s);
          }
          resubmit->with_ct_orig = true;
      } else {
          resubmit->with_ct_orig = false;
      }
  
      if (resubmit->in_port == OFPP_IN_PORT && resubmit->table_id == 255) {
          return xstrdup("at least one \"in_port\" or \"table\" must be "
                         "specified  on resubmit");
      }
      return NULL;
  }
  
  static void
  format_RESUBMIT(const struct ofpact_resubmit *a,
                  const struct ofpact_format_params *fp)
  {
      if (a->in_port != OFPP_IN_PORT && a->table_id == 255) {
          ds_put_format(fp->s, "%sresubmit:%s", colors.special, colors.end);
          ofputil_format_port(a->in_port, fp->port_map, fp->s);
      } else {
          ds_put_format(fp->s, "%sresubmit(%s", colors.paren, colors.end);
          if (a->in_port != OFPP_IN_PORT) {
              ofputil_format_port(a->in_port, fp->port_map, fp->s);
          }
          ds_put_char(fp->s, ',');
          if (a->table_id != 255) {
              ofputil_format_table(a->table_id, fp->table_map, fp->s);
          }
          if (a->with_ct_orig) {
              ds_put_cstr(fp->s, ",ct");
          }
          ds_put_format(fp->s, "%s)%s", colors.paren, colors.end);
      }
  }
  
  static enum ofperr
  check_RESUBMIT(const struct ofpact_resubmit *a,
                 const struct ofpact_check_params *cp)
  {
      if (a->with_ct_orig && !is_ct_valid(&cp->match->flow, &cp->match->wc,
                                          NULL)) {
          return OFPERR_OFPBAC_MATCH_INCONSISTENT;
      }
      return 0;
  }
  
  /* Action structure for NXAST_LEARN and NXAST_LEARN2.
   *
   * This action adds or modifies a flow in an OpenFlow table, similar to
   * OFPT_FLOW_MOD with OFPFC_MODIFY_STRICT as 'command'.  The new flow has the
   * specified idle timeout, hard timeout, priority, cookie, and flags.  The new
   * flow's match criteria and actions are built by applying each of the series
   * of flow_mod_spec elements included as part of the action.
   *
   * A flow_mod_spec starts with a 16-bit header.  A header that is all-bits-0 is
   * a no-op used for padding the action as a whole to a multiple of 8 bytes in
   * length.  Otherwise, the flow_mod_spec can be thought of as copying 'n_bits'
   * bits from a source to a destination.  In this case, the header contains
   * multiple fields:
   *
   *  15  14  13 12  11 10                              0
   * +------+---+------+---------------------------------+
   * |   0  |src|  dst |             n_bits              |
   * +------+---+------+---------------------------------+
   *
   * The meaning and format of a flow_mod_spec depends on 'src' and 'dst'.  The
   * following table summarizes the meaning of each possible combination.
   * Details follow the table:
   *
   *   src dst  meaning
   *   --- ---  ----------------------------------------------------------
   *    0   0   Add match criteria based on value in a field.
   *    1   0   Add match criteria based on an immediate value.
   *    0   1   Add NXAST_REG_LOAD action to copy field into a different field.
   *    1   1   Add NXAST_REG_LOAD action to load immediate value into a field.
   *    0   2   Add OFPAT_OUTPUT action to output to port from specified field.
   *   All other combinations are undefined and not allowed.
   *
   * The flow_mod_spec header is followed by a source specification and a
   * destination specification.  The format and meaning of the source
   * specification depends on 'src':
   *
   *   - If 'src' is 0, the source bits are taken from a field in the flow to
   *     which this action is attached.  (This should be a wildcarded field.  If
   *     its value is fully specified then the source bits being copied have
   *     constant values.)
   *
   *     The source specification is an ovs_be32 'field' and an ovs_be16 'ofs'.
   *     'field' is an nxm_header with nxm_hasmask=0, and 'ofs' the starting bit
   *     offset within that field.  The source bits are field[ofs:ofs+n_bits-1].
   *     'field' and 'ofs' are subject to the same restrictions as the source
   *     field in NXAST_REG_MOVE.
   *
   *   - If 'src' is 1, the source bits are a constant value.  The source
   *     specification is (n_bits+15)/16*2 bytes long.  Taking those bytes as a
   *     number in network order, the source bits are the 'n_bits'
   *     least-significant bits.  The switch will report an error if other bits
   *     in the constant are nonzero.
   *
   * The flow_mod_spec destination specification, for 'dst' of 0 or 1, is an
   * ovs_be32 'field' and an ovs_be16 'ofs'.  'field' is an nxm_header with
   * nxm_hasmask=0 and 'ofs' is a starting bit offset within that field.  The
   * meaning of the flow_mod_spec depends on 'dst':
   *
   *   - If 'dst' is 0, the flow_mod_spec specifies match criteria for the new
   *     flow.  The new flow matches only if bits field[ofs:ofs+n_bits-1] in a
   *     packet equal the source bits.  'field' may be any nxm_header with
   *     nxm_hasmask=0 that is allowed in NXT_FLOW_MOD.
   *
   *     Order is significant.  Earlier flow_mod_specs must satisfy any
   *     prerequisites for matching fields specified later, by copying constant
   *     values into prerequisite fields.
   *
   *     The switch will reject flow_mod_specs that do not satisfy NXM masking
   *     restrictions.
   *
   *   - If 'dst' is 1, the flow_mod_spec specifies an NXAST_REG_LOAD action for
   *     the new flow.  The new flow copies the source bits into
   *     field[ofs:ofs+n_bits-1].  Actions are executed in the same order as the
   *     flow_mod_specs.
   *
   *     A single NXAST_REG_LOAD action writes no more than 64 bits, so n_bits
   *     greater than 64 yields multiple NXAST_REG_LOAD actions.
   *
   * The flow_mod_spec destination spec for 'dst' of 2 (when 'src' is 0) is
   * empty.  It has the following meaning:
   *
   *   - The flow_mod_spec specifies an OFPAT_OUTPUT action for the new flow.
   *     The new flow outputs to the OpenFlow port specified by the source field.
   *     Of the special output ports with value OFPP_MAX or larger, OFPP_IN_PORT,
   *     OFPP_FLOOD, OFPP_LOCAL, and OFPP_ALL are supported.  Other special ports
   *     may not be used.
   *
   * Resource Management
   * -------------------
   *
   * A switch has a finite amount of flow table space available for learning.
   * When this space is exhausted, no new learning table entries will be learned
   * until some existing flow table entries expire.  The controller should be
   * prepared to handle this by flooding (which can be implemented as a
   * low-priority flow).
   *
   * If a learned flow matches a single TCP stream with a relatively long
   * timeout, one may make the best of resource constraints by setting
   * 'fin_idle_timeout' or 'fin_hard_timeout' (both measured in seconds), or
   * both, to shorter timeouts.  When either of these is specified as a nonzero
   * value, OVS adds a NXAST_FIN_TIMEOUT action, with the specified timeouts, to
   * the learned flow.
   *
   * Examples
   * --------
   *
   * The following examples give a prose description of the flow_mod_specs along
   * with informal notation for how those would be represented and a hex dump of
   * the bytes that would be required.
   *
   * These examples could work with various nx_action_learn parameters.  Typical
   * values would be idle_timeout=OFP_FLOW_PERMANENT, hard_timeout=60,
   * priority=OFP_DEFAULT_PRIORITY, flags=0, table_id=10.
   *
   * 1. Learn input port based on the source MAC, with lookup into
   *    NXM_NX_REG1[16:31] by resubmit to in_port=99:
   *
   *    Match on in_port=99:
   *       ovs_be16(src=1, dst=0, n_bits=16),               20 10
   *       ovs_be16(99),                                    00 63
   *       ovs_be32(NXM_OF_IN_PORT), ovs_be16(0)            00 00 00 02 00 00
   *
   *    Match Ethernet destination on Ethernet source from packet:
   *       ovs_be16(src=0, dst=0, n_bits=48),               00 30
   *       ovs_be32(NXM_OF_ETH_SRC), ovs_be16(0)            00 00 04 06 00 00
   *       ovs_be32(NXM_OF_ETH_DST), ovs_be16(0)            00 00 02 06 00 00
   *
   *    Set NXM_NX_REG1[16:31] to the packet's input port:
   *       ovs_be16(src=0, dst=1, n_bits=16),               08 10
   *       ovs_be32(NXM_OF_IN_PORT), ovs_be16(0)            00 00 00 02 00 00
   *       ovs_be32(NXM_NX_REG1), ovs_be16(16)              00 01 02 04 00 10
   *
   *    Given a packet that arrived on port A with Ethernet source address B,
   *    this would set up the flow "in_port=99, dl_dst=B,
   *    actions=load:A->NXM_NX_REG1[16..31]".
   *
   *    In syntax accepted by ovs-ofctl, this action is: learn(in_port=99,
   *    NXM_OF_ETH_DST[]=NXM_OF_ETH_SRC[],
   *    load:NXM_OF_IN_PORT[]->NXM_NX_REG1[16..31])
   *
   * 2. Output to input port based on the source MAC and VLAN VID, with lookup
   *    into NXM_NX_REG1[16:31]:
   *
   *    Match on same VLAN ID as packet:
   *       ovs_be16(src=0, dst=0, n_bits=12),               00 0c
   *       ovs_be32(NXM_OF_VLAN_TCI), ovs_be16(0)           00 00 08 02 00 00
   *       ovs_be32(NXM_OF_VLAN_TCI), ovs_be16(0)           00 00 08 02 00 00
   *
   *    Match Ethernet destination on Ethernet source from packet:
   *       ovs_be16(src=0, dst=0, n_bits=48),               00 30
   *       ovs_be32(NXM_OF_ETH_SRC), ovs_be16(0)            00 00 04 06 00 00
   *       ovs_be32(NXM_OF_ETH_DST), ovs_be16(0)            00 00 02 06 00 00
   *
   *    Output to the packet's input port:
   *       ovs_be16(src=0, dst=2, n_bits=16),               10 10
   *       ovs_be32(NXM_OF_IN_PORT), ovs_be16(0)            00 00 00 02 00 00
   *
   *    Given a packet that arrived on port A with Ethernet source address B in
   *    VLAN C, this would set up the flow "dl_dst=B, vlan_vid=C,
   *    actions=output:A".
   *
   *    In syntax accepted by ovs-ofctl, this action is:
   *    learn(NXM_OF_VLAN_TCI[0..11], NXM_OF_ETH_DST[]=NXM_OF_ETH_SRC[],
   *    output:NXM_OF_IN_PORT[])
   *
   * 3. Here's a recipe for a very simple-minded MAC learning switch.  It uses a
   *    10-second MAC expiration time to make it easier to see what's going on
   *
   *      ovs-vsctl del-controller br0
   *      ovs-ofctl del-flows br0
   *      ovs-ofctl add-flow br0 "table=0 actions=learn(table=1, \
            hard_timeout=10, NXM_OF_VLAN_TCI[0..11],             \
            NXM_OF_ETH_DST[]=NXM_OF_ETH_SRC[],                   \
            output:NXM_OF_IN_PORT[]), resubmit(,1)"
   *      ovs-ofctl add-flow br0 "table=1 priority=0 actions=flood"
   *
   *    You can then dump the MAC learning table with:
   *
   *      ovs-ofctl dump-flows br0 table=1
   *
   * Usage Advice
   * ------------
   *
   * For best performance, segregate learned flows into a table that is not used
   * for any other flows except possibly for a lowest-priority "catch-all" flow
   * (a flow with no match criteria).  If different learning actions specify
   * different match criteria, use different tables for the learned flows.
   *
   * The meaning of 'hard_timeout' and 'idle_timeout' can be counterintuitive.
   * These timeouts apply to the flow that is added, which means that a flow with
   * an idle timeout will expire when no traffic has been sent *to* the learned
   * address.  This is not usually the intent in MAC learning; instead, we want
   * the MAC learn entry to expire when no traffic has been sent *from* the
   * learned address.  Use a hard timeout for that.
   *
   *
   * Visibility of Changes
   * ---------------------
   *
   * Prior to Open vSwitch 2.4, any changes made by a "learn" action in a given
   * flow translation are visible to flow table lookups made later in the flow
   * translation.  This means that, in the example above, a MAC learned by the
   * learn action in table 0 would be found in table 1 (if the packet being
   * processed had the same source and destination MAC address).
   *
   * In Open vSwitch 2.4 and later, changes to a flow table (whether to add or
   * modify a flow) by a "learn" action are visible only for later flow
   * translations, not for later lookups within the same flow translation.  In
   * the MAC learning example, a MAC learned by the learn action in table 0 would
   * not be found in table 1 if the flow translation would resubmit to table 1
   * after the processing of the learn action, meaning that if this MAC had not
   * been learned before then the packet would be flooded. */
  struct nx_action_learn {
      ovs_be16 type;              /* OFPAT_VENDOR. */
      ovs_be16 len;               /* At least 24. */
      ovs_be32 vendor;            /* NX_VENDOR_ID. */
      ovs_be16 subtype;           /* NXAST_LEARN. */
      ovs_be16 idle_timeout;      /* Idle time before discarding (seconds). */
      ovs_be16 hard_timeout;      /* Max time before discarding (seconds). */
      ovs_be16 priority;          /* Priority level of flow entry. */
      ovs_be64 cookie;            /* Cookie for new flow. */
      ovs_be16 flags;             /* NX_LEARN_F_*. */
      uint8_t table_id;           /* Table to insert flow entry. */
      uint8_t pad;                /* Must be zero. */
      ovs_be16 fin_idle_timeout;  /* Idle timeout after FIN, if nonzero. */
      ovs_be16 fin_hard_timeout;  /* Hard timeout after FIN, if nonzero. */
      /* Followed by a sequence of flow_mod_spec elements, as described above,
       * until the end of the action is reached. */
  };
  OFP_ASSERT(sizeof(struct nx_action_learn) == 32);
  
  struct nx_action_learn2 {
      struct nx_action_learn up;  /* The wire format includes nx_action_learn. */
      ovs_be32 limit;             /* Maximum number of learned flows.
                                   * 0 indicates unlimited. */
  
      /* Where to store the result. */
      ovs_be16 result_dst_ofs;    /* Starting bit offset in destination. */
  
      ovs_be16 pad2;              /* Must be zero. */
      /* Followed by:
       * - OXM/NXM header for destination field (4 or 8 bytes),
       *   if NX_LEARN_F_WRITE_RESULT is set in 'flags'
       * - a sequence of flow_mod_spec elements, as described above,
       *   until the end of the action is reached. */
  };
  OFP_ASSERT(sizeof(struct nx_action_learn2) == 40);
  
  static ovs_be16
  get_be16(const void **pp)
  {
      const ovs_be16 *p = *pp;
      ovs_be16 value = *p;
      *pp = p + 1;
      return value;
  }
  
  static ovs_be32
  get_be32(const void **pp)
  {
      const ovs_be32 *p = *pp;
      ovs_be32 value = get_unaligned_be32(p);
      *pp = p + 1;
      return value;
  }
  
  static enum ofperr
  get_subfield(int n_bits, const void **p, struct mf_subfield *sf,
               const struct vl_mff_map *vl_mff_map, uint64_t *tlv_bitmap)
  {
      enum ofperr error;
  
      error = mf_vl_mff_mf_from_nxm_header(ntohl(get_be32(p)), vl_mff_map,
                                           &sf->field, tlv_bitmap);
      sf->ofs = ntohs(get_be16(p));
      sf->n_bits = n_bits;
      return error;
  }
  
  static unsigned int
  learn_min_len(uint16_t header)
  {
      int n_bits = header & NX_LEARN_N_BITS_MASK;
      int src_type = header & NX_LEARN_SRC_MASK;
      int dst_type = header & NX_LEARN_DST_MASK;
      unsigned int min_len;
  
      min_len = 0;
      if (src_type == NX_LEARN_SRC_FIELD) {
          min_len += sizeof(ovs_be32); /* src_field */
          min_len += sizeof(ovs_be16); /* src_ofs */
      } else {
          min_len += 2 * DIV_ROUND_UP(n_bits, 16);
      }
      if (dst_type == NX_LEARN_DST_MATCH ||
          dst_type == NX_LEARN_DST_LOAD) {
          min_len += sizeof(ovs_be32); /* dst_field */
          min_len += sizeof(ovs_be16); /* dst_ofs */
      }
      return min_len;
  }
  
  static enum ofperr
  decode_LEARN_common(const struct nx_action_learn *nal,
                      enum ofp_raw_action_type raw,
                      struct ofpact_learn *learn)
  {
      if (nal->pad) {
          return OFPERR_OFPBAC_BAD_ARGUMENT;
      }
  
      learn->ofpact.raw = raw;
      learn->idle_timeout = ntohs(nal->idle_timeout);
      learn->hard_timeout = ntohs(nal->hard_timeout);
      learn->priority = ntohs(nal->priority);
      learn->cookie = nal->cookie;
      learn->table_id = nal->table_id;
      learn->fin_idle_timeout = ntohs(nal->fin_idle_timeout);
      learn->fin_hard_timeout = ntohs(nal->fin_hard_timeout);
      learn->flags = ntohs(nal->flags);
  
      if (learn->table_id == 0xff) {
          return OFPERR_OFPBAC_BAD_ARGUMENT;
      }
  
      return 0;
  }
  
  static enum ofperr
  decode_LEARN_specs(const void *p, const void *end,
                     const struct vl_mff_map *vl_mff_map, uint64_t *tlv_bitmap,
                     struct ofpbuf *ofpacts)
  {
      struct ofpact_learn *learn = ofpacts->header;
  
      while (p != end) {
          struct ofpact_learn_spec *spec;
          uint16_t header = ntohs(get_be16(&p));
  
          if (!header) {
              break;
          }
  
          spec = ofpbuf_put_zeros(ofpacts, sizeof *spec);
          learn = ofpacts->header;
  
          spec->src_type = header & NX_LEARN_SRC_MASK;
          spec->dst_type = header & NX_LEARN_DST_MASK;
          spec->n_bits = header & NX_LEARN_N_BITS_MASK;
  
          /* Check for valid src and dst type combination. */
          if (spec->dst_type == NX_LEARN_DST_MATCH ||
              spec->dst_type == NX_LEARN_DST_LOAD ||
              (spec->dst_type == NX_LEARN_DST_OUTPUT &&
               spec->src_type == NX_LEARN_SRC_FIELD)) {
              /* OK. */
          } else {
              return OFPERR_OFPBAC_BAD_ARGUMENT;
          }
  
          /* Check that the arguments don't overrun the end of the action. */
          if ((char *) end - (char *) p < learn_min_len(header)) {
              return OFPERR_OFPBAC_BAD_LEN;
          }
  
          /* Get the source. */
          const uint8_t *imm = NULL;
          unsigned int imm_bytes = 0;
          enum ofperr error;
          if (spec->src_type == NX_LEARN_SRC_FIELD) {
              error = get_subfield(spec->n_bits, &p, &spec->src, vl_mff_map,
                                   tlv_bitmap);
              if (error) {
                  return error;
              }
          } else {
              int p_bytes = 2 * DIV_ROUND_UP(spec->n_bits, 16);
              p = (const uint8_t *) p + p_bytes;
  
              imm_bytes = DIV_ROUND_UP(spec->n_bits, 8);
              imm = (const uint8_t *) p - imm_bytes;
          }
  
          /* Get the destination. */
          if (spec->dst_type == NX_LEARN_DST_MATCH ||
              spec->dst_type == NX_LEARN_DST_LOAD) {
              error = get_subfield(spec->n_bits, &p, &spec->dst, vl_mff_map,
                                   tlv_bitmap);
              if (error) {
                  return error;
              }
          }
  
          if (imm) {
              uint8_t *src_imm = ofpbuf_put_zeros(ofpacts,
                                                  OFPACT_ALIGN(imm_bytes));
              memcpy(src_imm, imm, imm_bytes);
  
              learn = ofpacts->header;
          }
      }
      ofpact_finish_LEARN(ofpacts, &learn);
  
      if (!is_all_zeros(p, (char *) end - (char *) p)) {
          return OFPERR_OFPBAC_BAD_ARGUMENT;
      }
  
      return 0;
  }
  
  /* Converts 'nal' into a "struct ofpact_learn" and appends that struct to
   * 'ofpacts'.  Returns 0 if successful, otherwise an OFPERR_*. */
  static enum ofperr
  decode_NXAST_RAW_LEARN(const struct nx_action_learn *nal,
                         enum ofp_version ofp_version OVS_UNUSED,
                         const struct vl_mff_map *vl_mff_map,
                         uint64_t *tlv_bitmap, struct ofpbuf *ofpacts)
  {
      struct ofpact_learn *learn;
      enum ofperr error;
  
      learn = ofpact_put_LEARN(ofpacts);
  
      error = decode_LEARN_common(nal, NXAST_RAW_LEARN, learn);
      if (error) {
          return error;
      }
  
      if (learn->flags & ~(NX_LEARN_F_SEND_FLOW_REM |
                           NX_LEARN_F_DELETE_LEARNED)) {
          return OFPERR_OFPBAC_BAD_ARGUMENT;
      }
  
      return decode_LEARN_specs(nal + 1, (char *) nal + ntohs(nal->len),
                                vl_mff_map, tlv_bitmap, ofpacts);
  }
  
  /* Converts 'nal' into a "struct ofpact_learn" and appends that struct to
   * 'ofpacts'.  Returns 0 if successful, otherwise an OFPERR_*. */
  static enum ofperr
  decode_NXAST_RAW_LEARN2(const struct nx_action_learn2 *nal,
                          enum ofp_version ofp_version OVS_UNUSED,
                          const struct vl_mff_map *vl_mff_map,
                          uint64_t *tlv_bitmap, struct ofpbuf *ofpacts)
  {
      struct ofpbuf b = ofpbuf_const_initializer(nal, ntohs(nal->up.len));
      struct ofpact_learn *learn;
      enum ofperr error;
  
      if (nal->pad2) {
          return OFPERR_NXBAC_MUST_BE_ZERO;
      }
  
      learn = ofpact_put_LEARN(ofpacts);
      error = decode_LEARN_common(&nal->up, NXAST_RAW_LEARN2, learn);
      if (error) {
          return error;
      }
  
      learn->limit = ntohl(nal->limit);
  
      if (learn->flags & ~(NX_LEARN_F_SEND_FLOW_REM |
                           NX_LEARN_F_DELETE_LEARNED |
                           NX_LEARN_F_WRITE_RESULT)) {
          return OFPERR_OFPBAC_BAD_ARGUMENT;
      }
  
      ofpbuf_pull(&b, sizeof *nal);
  
      if (learn->flags & NX_LEARN_F_WRITE_RESULT) {
          error = nx_pull_header(&b, vl_mff_map, &learn->result_dst.field, NULL);
          if (error) {
              return error;
          }
          if (!learn->result_dst.field->writable) {
              return OFPERR_OFPBAC_BAD_SET_ARGUMENT;
          }
          learn->result_dst.ofs = ntohs(nal->result_dst_ofs);
          learn->result_dst.n_bits = 1;
      } else if (nal->result_dst_ofs) {
          return OFPERR_OFPBAC_BAD_ARGUMENT;
      }
  
      return decode_LEARN_specs(b.data, (char *) nal + ntohs(nal->up.len),
                                vl_mff_map, tlv_bitmap, ofpacts);
  }
  
  static void
  put_be16(struct ofpbuf *b, ovs_be16 x)
  {
      ofpbuf_put(b, &x, sizeof x);
  }
  
  static void
  put_be32(struct ofpbuf *b, ovs_be32 x)
  {
      ofpbuf_put(b, &x, sizeof x);
  }
  
  static void
  put_u16(struct ofpbuf *b, uint16_t x)
  {
      put_be16(b, htons(x));
  }
  
  static void
  put_u32(struct ofpbuf *b, uint32_t x)
  {
      put_be32(b, htonl(x));
  }
  
  static void
  encode_LEARN(const struct ofpact_learn *learn,
               enum ofp_version ofp_version OVS_UNUSED, struct ofpbuf *out)
  {
      const struct ofpact_learn_spec *spec;
      struct nx_action_learn *nal;
      size_t start_ofs;
  
      start_ofs = out->size;
  
      if (learn->ofpact.raw == NXAST_RAW_LEARN2
          || learn->limit != 0
          || learn->flags & NX_LEARN_F_WRITE_RESULT) {
          struct nx_action_learn2 *nal2;
  
          nal2 = put_NXAST_LEARN2(out);
          nal2->limit = htonl(learn->limit);
          nal2->result_dst_ofs = htons(learn->result_dst.ofs);
          nal = &nal2->up;
      } else {
          nal = put_NXAST_LEARN(out);
      }
      nal->idle_timeout = htons(learn->idle_timeout);
      nal->hard_timeout = htons(learn->hard_timeout);
      nal->fin_idle_timeout = htons(learn->fin_idle_timeout);
      nal->fin_hard_timeout = htons(learn->fin_hard_timeout);
      nal->priority = htons(learn->priority);
      nal->cookie = learn->cookie;
      nal->flags = htons(learn->flags);
      nal->table_id = learn->table_id;
  
      if (learn->flags & NX_LEARN_F_WRITE_RESULT) {
          nx_put_header(out, learn->result_dst.field->id, 0, false);
      }
  
      OFPACT_LEARN_SPEC_FOR_EACH (spec, learn) {
          put_u16(out, spec->n_bits | spec->dst_type | spec->src_type);
  
          if (spec->src_type == NX_LEARN_SRC_FIELD) {
              put_u32(out, nxm_header_from_mff(spec->src.field));
              put_u16(out, spec->src.ofs);
          } else {
              size_t n_dst_bytes = 2 * DIV_ROUND_UP(spec->n_bits, 16);
              uint8_t *bits = ofpbuf_put_zeros(out, n_dst_bytes);
              unsigned int n_bytes = DIV_ROUND_UP(spec->n_bits, 8);
  
              memcpy(bits + n_dst_bytes - n_bytes, ofpact_learn_spec_imm(spec),
                     n_bytes);
          }
  
          if (spec->dst_type == NX_LEARN_DST_MATCH ||
              spec->dst_type == NX_LEARN_DST_LOAD) {
              put_u32(out, nxm_header_from_mff(spec->dst.field));
              put_u16(out, spec->dst.ofs);
          }
      }
  
      pad_ofpat(out, start_ofs);
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_LEARN(char *arg, const struct ofpact_parse_params *pp)
  {
      return learn_parse(arg, pp->port_map, pp->table_map, pp->ofpacts);
  }
  
  static void
  format_LEARN(const struct ofpact_learn *a,
               const struct ofpact_format_params *fp)
  {
      learn_format(a, fp->port_map, fp->table_map, fp->s);
  }
  
  static enum ofperr
  check_LEARN(const struct ofpact_learn *a,
              const struct ofpact_check_params *cp)
  {
      return learn_check(a, cp->match);
  }
  
  /* Action structure for NXAST_CONJUNCTION. */
  struct nx_action_conjunction {
      ovs_be16 type;                  /* OFPAT_VENDOR. */
      ovs_be16 len;                   /* At least 16. */
      ovs_be32 vendor;                /* NX_VENDOR_ID. */
      ovs_be16 subtype;               /* See enum ofp_raw_action_type. */
      uint8_t clause;
      uint8_t n_clauses;
      ovs_be32 id;
  };
  OFP_ASSERT(sizeof(struct nx_action_conjunction) == 16);
  
  static void
  add_conjunction(struct ofpbuf *out,
                  uint32_t id, uint8_t clause, uint8_t n_clauses)
  {
      struct ofpact_conjunction *oc;
  
      oc = ofpact_put_CONJUNCTION(out);
      oc->id = id;
      oc->clause = clause;
      oc->n_clauses = n_clauses;
  }
  
  static enum ofperr
  decode_NXAST_RAW_CONJUNCTION(const struct nx_action_conjunction *nac,
                               enum ofp_version ofp_version OVS_UNUSED,
                               struct ofpbuf *out)
  {
      if (nac->n_clauses < 2 || nac->n_clauses > 64
          || nac->clause >= nac->n_clauses) {
          return OFPERR_NXBAC_BAD_CONJUNCTION;
      } else {
          add_conjunction(out, ntohl(nac->id), nac->clause, nac->n_clauses);
          return 0;
      }
  }
  
  static void
  encode_CONJUNCTION(const struct ofpact_conjunction *oc,
                     enum ofp_version ofp_version OVS_UNUSED, struct ofpbuf *out)
  {
      struct nx_action_conjunction *nac = put_NXAST_CONJUNCTION(out);
      nac->clause = oc->clause;
      nac->n_clauses = oc->n_clauses;
      nac->id = htonl(oc->id);
  }
  
  static void
  format_CONJUNCTION(const struct ofpact_conjunction *oc,
                     const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%sconjunction(%s%"PRIu32",%d/%"PRIu8"%s)%s",
                    colors.paren, colors.end,
                    oc->id, oc->clause + 1, oc->n_clauses,
                    colors.paren, colors.end);
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_CONJUNCTION(const char *arg, const struct ofpact_parse_params *pp)
  {
      uint8_t n_clauses;
      uint8_t clause;
      uint32_t id;
      int n;
  
      if (!ovs_scan(arg, "%"SCNi32" , %"SCNu8" / %"SCNu8" %n",
                    &id, &clause, &n_clauses, &n) || n != strlen(arg)) {
          return xstrdup("\"conjunction\" syntax is \"conjunction(id,i/n)\"");
      }
  
      if (n_clauses < 2) {
          return xstrdup("conjunction must have at least 2 clauses");
      } else if (n_clauses > 64) {
          return xstrdup("conjunction must have at most 64 clauses");
      } else if (clause < 1) {
          return xstrdup("clause index must be positive");
      } else if (clause > n_clauses) {
          return xstrdup("clause index must be less than or equal to "
                         "number of clauses");
      }
  
      add_conjunction(pp->ofpacts, id, clause - 1, n_clauses);
      return NULL;
  }
  
  static enum ofperr
  check_CONJUNCTION(const struct ofpact_conjunction *a OVS_UNUSED,
                    const struct ofpact_check_params *cp OVS_UNUSED)
  {
      return 0;
  }
  
  /* Action structure for NXAST_MULTIPATH.
   *
   * This action performs the following steps in sequence:
   *
   *    1. Hashes the fields designated by 'fields', one of NX_HASH_FIELDS_*.
   *       Refer to the definition of "enum nx_mp_fields" for details.
   *
   *       The 'basis' value is used as a universal hash parameter, that is,
   *       different values of 'basis' yield different hash functions.  The
   *       particular universal hash function used is implementation-defined.
   *
   *       The hashed fields' values are drawn from the current state of the
   *       flow, including all modifications that have been made by actions up to
   *       this point.
   *
   *    2. Applies the multipath link choice algorithm specified by 'algorithm',
   *       one of NX_MP_ALG_*.  Refer to the definition of "enum nx_mp_algorithm"
   *       for details.
   *
   *       The output of the algorithm is 'link', an unsigned integer less than
   *       or equal to 'max_link'.
   *
   *       Some algorithms use 'arg' as an additional argument.
   *
   *    3. Stores 'link' in dst[ofs:ofs+n_bits].  The format and semantics of
   *       'dst' and 'ofs_nbits' are similar to those for the NXAST_REG_LOAD
   *       action.
   *
   * The switch will reject actions that have an unknown 'fields', or an unknown
   * 'algorithm', or in which ofs+n_bits is greater than the width of 'dst', or
   * in which 'max_link' is greater than or equal to 2**n_bits, with error type
   * OFPET_BAD_ACTION, code OFPBAC_BAD_ARGUMENT.
   */
  struct nx_action_multipath {
      ovs_be16 type;              /* OFPAT_VENDOR. */
      ovs_be16 len;               /* Length is 32. */
      ovs_be32 vendor;            /* NX_VENDOR_ID. */
      ovs_be16 subtype;           /* NXAST_MULTIPATH. */
  
      /* What fields to hash and how. */
      ovs_be16 fields;            /* One of NX_HASH_FIELDS_*. */
      ovs_be16 basis;             /* Universal hash parameter. */
      ovs_be16 pad0;
  
      /* Multipath link choice algorithm to apply to hash value. */
      ovs_be16 algorithm;         /* One of NX_MP_ALG_*. */
      ovs_be16 max_link;          /* Number of output links, minus 1. */
      ovs_be32 arg;               /* Algorithm-specific argument. */
      ovs_be16 pad1;
  
      /* Where to store the result. */
      ovs_be16 ofs_nbits;         /* (ofs << 6) | (n_bits - 1). */
      ovs_be32 dst;               /* Destination. */
  };
  OFP_ASSERT(sizeof(struct nx_action_multipath) == 32);
  
  static enum ofperr
  decode_NXAST_RAW_MULTIPATH(const struct nx_action_multipath *nam,
                             enum ofp_version ofp_version OVS_UNUSED,
                             const struct vl_mff_map *vl_mff_map,
                             uint64_t *tlv_bitmap, struct ofpbuf *out)
  {
      uint32_t n_links = ntohs(nam->max_link) + 1;
      size_t min_n_bits = log_2_ceil(n_links);
      struct ofpact_multipath *mp;
      enum ofperr error;
  
      mp = ofpact_put_MULTIPATH(out);
      mp->fields = ntohs(nam->fields);
      mp->basis = ntohs(nam->basis);
      mp->algorithm = ntohs(nam->algorithm);
      mp->max_link = ntohs(nam->max_link);
      mp->arg = ntohl(nam->arg);
      mp->dst.ofs = nxm_decode_ofs(nam->ofs_nbits);
      mp->dst.n_bits = nxm_decode_n_bits(nam->ofs_nbits);
      error = mf_vl_mff_mf_from_nxm_header(ntohl(nam->dst), vl_mff_map,
                                           &mp->dst.field, tlv_bitmap);
      if (error) {
          return error;
      }
  
      if (!flow_hash_fields_valid(mp->fields)) {
          VLOG_WARN_RL(&rl, "unsupported fields %d", (int) mp->fields);
          return OFPERR_OFPBAC_BAD_ARGUMENT;
      } else if (mp->algorithm != NX_MP_ALG_MODULO_N
                 && mp->algorithm != NX_MP_ALG_HASH_THRESHOLD
                 && mp->algorithm != NX_MP_ALG_HRW
                 && mp->algorithm != NX_MP_ALG_ITER_HASH) {
          VLOG_WARN_RL(&rl, "unsupported algorithm %d", (int) mp->algorithm);
          return OFPERR_OFPBAC_BAD_ARGUMENT;
      } else if (mp->dst.n_bits < min_n_bits) {
          VLOG_WARN_RL(&rl, "multipath action requires at least %"PRIuSIZE" bits for "
                       "%"PRIu32" links", min_n_bits, n_links);
          return OFPERR_OFPBAC_BAD_ARGUMENT;
      }
  
      return multipath_check(mp, NULL);
  }
  
  static void
  encode_MULTIPATH(const struct ofpact_multipath *mp,
                   enum ofp_version ofp_version OVS_UNUSED, struct ofpbuf *out)
  {
      struct nx_action_multipath *nam = put_NXAST_MULTIPATH(out);
  
      nam->fields = htons(mp->fields);
      nam->basis = htons(mp->basis);
      nam->algorithm = htons(mp->algorithm);
      nam->max_link = htons(mp->max_link);
      nam->arg = htonl(mp->arg);
      nam->ofs_nbits = nxm_encode_ofs_nbits(mp->dst.ofs, mp->dst.n_bits);
      nam->dst = htonl(nxm_header_from_mff(mp->dst.field));
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_MULTIPATH(const char *arg, const struct ofpact_parse_params *pp)
  {
      return multipath_parse(ofpact_put_MULTIPATH(pp->ofpacts), arg);
  }
  
  static void
  format_MULTIPATH(const struct ofpact_multipath *a,
                   const struct ofpact_format_params *fp)
  {
      multipath_format(a, fp->s);
  }
  
  static enum ofperr
  check_MULTIPATH(const struct ofpact_multipath *a,
                  const struct ofpact_check_params *cp)
  {
      return multipath_check(a, cp->match);
  }
  
  /* Action structure for NXAST_NOTE.
   *
   * This action has no effect.  It is variable length.  The switch does not
   * attempt to interpret the user-defined 'note' data in any way.  A controller
   * can use this action to attach arbitrary metadata to a flow.
   *
   * This action might go away in the future.
   */
  struct nx_action_note {
      ovs_be16 type;                  /* OFPAT_VENDOR. */
      ovs_be16 len;                   /* A multiple of 8, but at least 16. */
      ovs_be32 vendor;                /* NX_VENDOR_ID. */
      ovs_be16 subtype;               /* NXAST_NOTE. */
      uint8_t note[6];                /* Start of user-defined data. */
      /* Possibly followed by additional user-defined data. */
  };
  OFP_ASSERT(sizeof(struct nx_action_note) == 16);
  
  static enum ofperr
  decode_NXAST_RAW_NOTE(const struct nx_action_note *nan,
                        enum ofp_version ofp_version OVS_UNUSED,
                        struct ofpbuf *out)
  {
      struct ofpact_note *note;
      unsigned int length;
  
      length = ntohs(nan->len) - offsetof(struct nx_action_note, note);
      note = ofpact_put_NOTE(out);
      note->length = length;
      ofpbuf_put(out, nan->note, length);
      note = out->header;
      ofpact_finish_NOTE(out, &note);
  
      return 0;
  }
  
  static void
  encode_NOTE(const struct ofpact_note *note,
              enum ofp_version ofp_version OVS_UNUSED, struct ofpbuf *out)
  {
      size_t start_ofs = out->size;
      struct nx_action_note *nan;
  
      put_NXAST_NOTE(out);
      out->size = out->size - sizeof nan->note;
  
      ofpbuf_put(out, note->data, note->length);
      pad_ofpat(out, start_ofs);
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_NOTE(const char *arg, const struct ofpact_parse_params *pp)
  {
      size_t start_ofs = pp->ofpacts->size;
      ofpact_put_NOTE(pp->ofpacts);
      arg = ofpbuf_put_hex(pp->ofpacts, arg, NULL);
      if (arg[0]) {
          return xstrdup("bad hex digit in `note' argument");
      }
      struct ofpact_note *note = ofpbuf_at_assert(pp->ofpacts, start_ofs,
                                                  sizeof *note);
      note->length = pp->ofpacts->size - (start_ofs + sizeof *note);
      ofpact_finish_NOTE(pp->ofpacts, &note);
      return NULL;
  }
  
  static void
  format_NOTE(const struct ofpact_note *a,
              const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%snote:%s", colors.param, colors.end);
      format_hex_arg(fp->s, a->data, a->length);
  }
  
  static enum ofperr
  check_NOTE(const struct ofpact_note *a OVS_UNUSED,
             const struct ofpact_check_params *cp OVS_UNUSED)
  {
      return 0;
  }
  
  /* Exit action. */
  
  static enum ofperr
  decode_NXAST_RAW_EXIT(struct ofpbuf *out)
  {
      ofpact_put_EXIT(out);
      return 0;
  }
  
  static void
  encode_EXIT(const struct ofpact_null *null OVS_UNUSED,
              enum ofp_version ofp_version OVS_UNUSED, struct ofpbuf *out)
  {
      put_NXAST_EXIT(out);
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_EXIT(char *arg OVS_UNUSED, const struct ofpact_parse_params *pp)
  {
      ofpact_put_EXIT(pp->ofpacts);
      return NULL;
  }
  
  static void
  format_EXIT(const struct ofpact_null *a OVS_UNUSED,
              const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%sexit%s", colors.special, colors.end);
  }
  
  static enum ofperr
  check_EXIT(const struct ofpact_null *a OVS_UNUSED,
             const struct ofpact_check_params *cp OVS_UNUSED)
  {
      return 0;
  }
  
  /* Unroll xlate action. */
  
  static void
  encode_UNROLL_XLATE(const struct ofpact_unroll_xlate *unroll OVS_UNUSED,
                      enum ofp_version ofp_version OVS_UNUSED,
                      struct ofpbuf *out OVS_UNUSED)
  {
      OVS_NOT_REACHED();
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_UNROLL_XLATE(char *arg OVS_UNUSED,
                     const struct ofpact_parse_params *pp OVS_UNUSED)
  {
      OVS_NOT_REACHED();
  }
  
  static void
  format_UNROLL_XLATE(const struct ofpact_unroll_xlate *a,
                      const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%sunroll_xlate(%s%stable=%s",
                    colors.paren,   colors.end,
                    colors.special, colors.end);
      ofputil_format_table(a->rule_table_id, fp->table_map, fp->s);
      ds_put_format(fp->s, ", %scookie=%s%"PRIu64"%s)%s",
                    colors.param,   colors.end, ntohll(a->rule_cookie),
                    colors.paren,   colors.end);
  }
  
  static enum ofperr
  check_UNROLL_XLATE(const struct ofpact_unroll_xlate *a OVS_UNUSED,
                     const struct ofpact_check_params *cp OVS_UNUSED)
  {
      /* UNROLL is an internal action that should never be seen via OpenFlow. */
      return OFPERR_OFPBAC_BAD_TYPE;
  }
  
  /* The NXAST_CLONE action is "struct ext_action_header", followed by zero or
   * more embedded OpenFlow actions. */
  
  static enum ofperr
  decode_NXAST_RAW_CLONE(const struct ext_action_header *eah,
                         enum ofp_version ofp_version,
                         const struct vl_mff_map *vl_mff_map,
                         uint64_t *tlv_bitmap, struct ofpbuf *out)
  {
      int error;
      struct ofpbuf openflow;
      const size_t clone_offset = ofpacts_pull(out);
      struct ofpact_nest *clone = ofpact_put_CLONE(out);
  
      /* decode action list */
      ofpbuf_pull(out, sizeof(*clone));
      openflow = ofpbuf_const_initializer(
                      eah + 1, ntohs(eah->len) - sizeof *eah);
      error = ofpacts_pull_openflow_actions__(&openflow, openflow.size,
                                              ofp_version,
                                              1u << OVSINST_OFPIT11_APPLY_ACTIONS,
                                              out, 0, vl_mff_map, tlv_bitmap);
      if (error) {
          return error;
      }
      clone = ofpbuf_push_uninit(out, sizeof *clone);
      out->header = &clone->ofpact;
      ofpact_finish_CLONE(out, &clone);
      ofpbuf_push_uninit(out, clone_offset);
      return error;
  }
  
  static void
  encode_CLONE(const struct ofpact_nest *clone,
                enum ofp_version ofp_version, struct ofpbuf *out)
  {
      size_t len;
      const size_t ofs = out->size;
      struct ext_action_header *eah;
  
      put_NXAST_CLONE(out);
      len = ofpacts_put_openflow_actions(clone->actions,
                                         ofpact_nest_get_action_len(clone),
                                         out, ofp_version);
      len += sizeof *eah;
      eah = ofpbuf_at(out, ofs, sizeof *eah);
      eah->len = htons(len);
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_CLONE(char *arg, const struct ofpact_parse_params *pp)
  {
      const size_t clone_offset = ofpacts_pull(pp->ofpacts);
      struct ofpact_nest *clone = ofpact_put_CLONE(pp->ofpacts);
      char *error;
  
      ofpbuf_pull(pp->ofpacts, sizeof *clone);
      error = ofpacts_parse_copy(arg, pp, false, 0);
      /* header points to the action list */
      pp->ofpacts->header = ofpbuf_push_uninit(pp->ofpacts, sizeof *clone);
      clone = pp->ofpacts->header;
  
      ofpact_finish_CLONE(pp->ofpacts, &clone);
      ofpbuf_push_uninit(pp->ofpacts, clone_offset);
      return error;
  }
  
  static void
  format_CLONE(const struct ofpact_nest *a,
               const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%sclone(%s", colors.paren, colors.end);
      ofpacts_format(a->actions, ofpact_nest_get_action_len(a), fp);
      ds_put_format(fp->s, "%s)%s", colors.paren, colors.end);
  }
  
  static enum ofperr
  check_subactions(struct ofpact *ofpacts, size_t ofpacts_len,
                   struct ofpact_check_params *cp)
  {
      struct ofpact_check_params sub = *cp;
      enum ofperr error = ofpacts_check(ofpacts, ofpacts_len, &sub);
      cp->usable_protocols &= sub.usable_protocols;
      return error;
  }
  
  static enum ofperr
  check_CLONE(struct ofpact_nest *a, struct ofpact_check_params *cp)
  {
      return check_subactions(a->actions, ofpact_nest_get_action_len(a), cp);
  }
  
  /* Action structure for NXAST_SAMPLE.
   *
   * Samples matching packets with the given probability and sends them
   * each to the set of collectors identified with the given ID.  The
   * probability is expressed as a number of packets to be sampled out
   * of USHRT_MAX packets, and must be >0.
   *
   * When sending packet samples to IPFIX collectors, the IPFIX flow
   * record sent for each sampled packet is associated with the given
   * observation domain ID and observation point ID.  Each IPFIX flow
   * record contain the sampled packet's headers when executing this
   * rule.  If a sampled packet's headers are modified by previous
   * actions in the flow, those modified headers are sent. */
  struct nx_action_sample {
      ovs_be16 type;                  /* OFPAT_VENDOR. */
      ovs_be16 len;                   /* Length is 24. */
      ovs_be32 vendor;                /* NX_VENDOR_ID. */
      ovs_be16 subtype;               /* NXAST_SAMPLE. */
      ovs_be16 probability;           /* Fraction of packets to sample. */
      ovs_be32 collector_set_id;      /* ID of collector set in OVSDB. */
      ovs_be32 obs_domain_id;         /* ID of sampling observation domain. */
      ovs_be32 obs_point_id;          /* ID of sampling observation point. */
  };
  OFP_ASSERT(sizeof(struct nx_action_sample) == 24);
  
  /* Action structure for NXAST_SAMPLE2 and NXAST_SAMPLE3.
   *
   * NXAST_SAMPLE2 was added in Open vSwitch 2.5.90.  Compared to NXAST_SAMPLE,
   * it adds support for exporting egress tunnel information.
   *
   * NXAST_SAMPLE3 was added in Open vSwitch 2.6.90.  Compared to NXAST_SAMPLE2,
   * it adds support for the 'direction' field. */
  struct nx_action_sample2 {
      ovs_be16 type;                  /* OFPAT_VENDOR. */
      ovs_be16 len;                   /* Length is 32. */
      ovs_be32 vendor;                /* NX_VENDOR_ID. */
      ovs_be16 subtype;               /* NXAST_SAMPLE. */
      ovs_be16 probability;           /* Fraction of packets to sample. */
      ovs_be32 collector_set_id;      /* ID of collector set in OVSDB. */
      ovs_be32 obs_domain_id;         /* ID of sampling observation domain. */
      ovs_be32 obs_point_id;          /* ID of sampling observation point. */
      ovs_be16 sampling_port;         /* Sampling port. */
      uint8_t  direction;             /* NXAST_SAMPLE3 only. */
      uint8_t  zeros[5];              /* Pad to a multiple of 8 bytes */
   };
   OFP_ASSERT(sizeof(struct nx_action_sample2) == 32);
  
  static enum ofperr
  decode_NXAST_RAW_SAMPLE(const struct nx_action_sample *nas,
                          enum ofp_version ofp_version OVS_UNUSED,
                          struct ofpbuf *out)
  {
      struct ofpact_sample *sample;
  
      sample = ofpact_put_SAMPLE(out);
      sample->ofpact.raw = NXAST_RAW_SAMPLE;
      sample->probability = ntohs(nas->probability);
      sample->collector_set_id = ntohl(nas->collector_set_id);
      sample->obs_domain_id = ntohl(nas->obs_domain_id);
      sample->obs_point_id = ntohl(nas->obs_point_id);
      sample->sampling_port = OFPP_NONE;
      sample->direction = NX_ACTION_SAMPLE_DEFAULT;
  
      if (sample->probability == 0) {
          return OFPERR_OFPBAC_BAD_ARGUMENT;
      }
  
      return 0;
  }
  
  static enum ofperr
  decode_SAMPLE2(const struct nx_action_sample2 *nas,
                 enum ofp_raw_action_type raw,
                 enum nx_action_sample_direction direction,
                 struct ofpact_sample *sample)
  {
      sample->ofpact.raw = raw;
      sample->probability = ntohs(nas->probability);
      sample->collector_set_id = ntohl(nas->collector_set_id);
      sample->obs_domain_id = ntohl(nas->obs_domain_id);
      sample->obs_point_id = ntohl(nas->obs_point_id);
      sample->sampling_port = u16_to_ofp(ntohs(nas->sampling_port));
      sample->direction = direction;
  
      if (sample->probability == 0) {
          return OFPERR_OFPBAC_BAD_ARGUMENT;
      }
  
      return 0;
  }
  
  static enum ofperr
  decode_NXAST_RAW_SAMPLE2(const struct nx_action_sample2 *nas,
                           enum ofp_version ofp_version OVS_UNUSED,
                           struct ofpbuf *out)
  {
      return decode_SAMPLE2(nas, NXAST_RAW_SAMPLE2, NX_ACTION_SAMPLE_DEFAULT,
                            ofpact_put_SAMPLE(out));
  }
  
  static enum ofperr
  decode_NXAST_RAW_SAMPLE3(const struct nx_action_sample2 *nas,
                           enum ofp_version ofp_version OVS_UNUSED,
                           struct ofpbuf *out)
  {
      struct ofpact_sample *sample = ofpact_put_SAMPLE(out);
      if (!is_all_zeros(nas->zeros, sizeof nas->zeros)) {
          return OFPERR_NXBRC_MUST_BE_ZERO;
      }
      if (nas->direction != NX_ACTION_SAMPLE_DEFAULT &&
          nas->direction != NX_ACTION_SAMPLE_INGRESS &&
          nas->direction != NX_ACTION_SAMPLE_EGRESS) {
          VLOG_WARN_RL(&rl, "invalid sample direction %"PRIu8, nas->direction);
          return OFPERR_OFPBAC_BAD_ARGUMENT;
      }
      return decode_SAMPLE2(nas, NXAST_RAW_SAMPLE3, nas->direction, sample);
  }
  
  static void
  encode_SAMPLE2(const struct ofpact_sample *sample,
                 struct nx_action_sample2 *nas)
  {
      nas->probability = htons(sample->probability);
      nas->collector_set_id = htonl(sample->collector_set_id);
      nas->obs_domain_id = htonl(sample->obs_domain_id);
      nas->obs_point_id = htonl(sample->obs_point_id);
      nas->sampling_port = htons(ofp_to_u16(sample->sampling_port));
      nas->direction = sample->direction;
  }
  
  static void
  encode_SAMPLE(const struct ofpact_sample *sample,
                enum ofp_version ofp_version OVS_UNUSED, struct ofpbuf *out)
  {
      if (sample->ofpact.raw == NXAST_RAW_SAMPLE3
          || sample->direction != NX_ACTION_SAMPLE_DEFAULT) {
          encode_SAMPLE2(sample, put_NXAST_SAMPLE3(out));
      } else if (sample->ofpact.raw == NXAST_RAW_SAMPLE2
                 || sample->sampling_port != OFPP_NONE) {
          encode_SAMPLE2(sample, put_NXAST_SAMPLE2(out));
      } else {
          struct nx_action_sample *nas = put_NXAST_SAMPLE(out);
          nas->probability = htons(sample->probability);
          nas->collector_set_id = htonl(sample->collector_set_id);
          nas->obs_domain_id = htonl(sample->obs_domain_id);
          nas->obs_point_id = htonl(sample->obs_point_id);
      }
  }
  
  /* Parses 'arg' as the argument to a "sample" action, and appends such an
   * action to 'pp->ofpacts'.
   *
   * Returns NULL if successful, otherwise a malloc()'d string describing the
   * error.  The caller is responsible for freeing the returned string. */
  static char * OVS_WARN_UNUSED_RESULT
  parse_SAMPLE(char *arg, const struct ofpact_parse_params *pp)
  {
      struct ofpact_sample *os = ofpact_put_SAMPLE(pp->ofpacts);
      os->sampling_port = OFPP_NONE;
      os->direction = NX_ACTION_SAMPLE_DEFAULT;
  
      char *key, *value;
      while (ofputil_parse_key_value(&arg, &key, &value)) {
          char *error = NULL;
  
          if (!strcmp(key, "probability")) {
              error = str_to_u16(value, "probability", &os->probability);
              if (!error && os->probability == 0) {
                  error = xasprintf("invalid probability value \"%s\"", value);
              }
          } else if (!strcmp(key, "collector_set_id")) {
              error = str_to_u32(value, &os->collector_set_id);
          } else if (!strcmp(key, "obs_domain_id")) {
              error = str_to_u32(value, &os->obs_domain_id);
          } else if (!strcmp(key, "obs_point_id")) {
              error = str_to_u32(value, &os->obs_point_id);
          } else if (!strcmp(key, "sampling_port")) {
              if (!ofputil_port_from_string(value, pp->port_map,
                                            &os->sampling_port)) {
                  error = xasprintf("%s: unknown port", value);
              }
          } else if (!strcmp(key, "ingress")) {
              os->direction = NX_ACTION_SAMPLE_INGRESS;
          } else if (!strcmp(key, "egress")) {
              os->direction = NX_ACTION_SAMPLE_EGRESS;
          } else {
              error = xasprintf("invalid key \"%s\" in \"sample\" argument",
                                key);
          }
          if (error) {
              return error;
          }
      }
      if (os->probability == 0) {
          return xstrdup("non-zero \"probability\" must be specified on sample");
      }
  
      return NULL;
  }
  
  static void
  format_SAMPLE(const struct ofpact_sample *a,
                const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%ssample(%s%sprobability=%s%"PRIu16
                    ",%scollector_set_id=%s%"PRIu32
                    ",%sobs_domain_id=%s%"PRIu32
                    ",%sobs_point_id=%s%"PRIu32,
                    colors.paren, colors.end,
                    colors.param, colors.end, a->probability,
                    colors.param, colors.end, a->collector_set_id,
                    colors.param, colors.end, a->obs_domain_id,
                    colors.param, colors.end, a->obs_point_id);
      if (a->sampling_port != OFPP_NONE) {
          ds_put_format(fp->s, ",%ssampling_port=%s", colors.param, colors.end);
          ofputil_format_port(a->sampling_port, fp->port_map, fp->s);
      }
      if (a->direction == NX_ACTION_SAMPLE_INGRESS) {
          ds_put_format(fp->s, ",%singress%s", colors.param, colors.end);
      } else if (a->direction == NX_ACTION_SAMPLE_EGRESS) {
          ds_put_format(fp->s, ",%segress%s", colors.param, colors.end);
      }
      ds_put_format(fp->s, "%s)%s", colors.paren, colors.end);
  }
  
  static enum ofperr
  check_SAMPLE(const struct ofpact_sample *a OVS_UNUSED,
               const struct ofpact_check_params *cp OVS_UNUSED)
  {
      return 0;
  }
  
  /* debug instructions. */
  
  static bool enable_debug;
  
  void
  ofpact_dummy_enable(void)
  {
      enable_debug = true;
  }
  
  static enum ofperr
  decode_NXAST_RAW_DEBUG_RECIRC(struct ofpbuf *out)
  {
      if (!enable_debug) {
          return OFPERR_OFPBAC_BAD_VENDOR_TYPE;
      }
  
      ofpact_put_DEBUG_RECIRC(out);
      return 0;
  }
  
  static void
  encode_DEBUG_RECIRC(const struct ofpact_null *n OVS_UNUSED,
                      enum ofp_version ofp_version OVS_UNUSED,
                      struct ofpbuf *out)
  {
      put_NXAST_DEBUG_RECIRC(out);
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_DEBUG_RECIRC(char *arg OVS_UNUSED, const struct ofpact_parse_params *pp)
  {
      ofpact_put_DEBUG_RECIRC(pp->ofpacts);
      return NULL;
  }
  
  static void
  format_DEBUG_RECIRC(const struct ofpact_null *a OVS_UNUSED,
                      const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%sdebug_recirc%s", colors.value, colors.end);
  }
  
  static enum ofperr
  check_DEBUG_RECIRC(const struct ofpact_null *a OVS_UNUSED,
                     const struct ofpact_check_params *cp OVS_UNUSED)
  {
      return 0;
  }
  
  static enum ofperr
  decode_NXAST_RAW_DEBUG_SLOW(struct ofpbuf *out)
  {
      if (!enable_debug) {
          return OFPERR_OFPBAC_BAD_VENDOR_TYPE;
      }
  
      ofpact_put_DEBUG_SLOW(out);
      return 0;
  }
  
  static void
  encode_DEBUG_SLOW(const struct ofpact_null *n OVS_UNUSED,
                    enum ofp_version ofp_version OVS_UNUSED,
                    struct ofpbuf *out)
  {
      put_NXAST_DEBUG_SLOW(out);
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_DEBUG_SLOW(char *arg OVS_UNUSED, const struct ofpact_parse_params *pp)
  {
      ofpact_put_DEBUG_SLOW(pp->ofpacts);
      return NULL;
  }
  
  static void
  format_DEBUG_SLOW(const struct ofpact_null *a OVS_UNUSED,
                    const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%sdebug_slow%s", colors.value, colors.end);
  }
  
  static enum ofperr
  check_DEBUG_SLOW(const struct ofpact_null *a OVS_UNUSED,
                   const struct ofpact_check_params *cp OVS_UNUSED)
  {
      return 0;
  }
  
  /* Action structure for NXAST_CT.
   *
   * Pass traffic to the connection tracker.
   *
   * There are two important concepts to understanding the connection tracking
   * interface: Packet state and Connection state. Packets may be "Untracked" or
   * "Tracked". Connections may be "Uncommitted" or "Committed".
   *
   *   - Packet State:
   *
   *      Untracked packets have an unknown connection state.  In most
   *      cases, packets entering the OpenFlow pipeline will initially be
   *      in the untracked state. Untracked packets may become tracked by
   *      executing NXAST_CT with a "recirc_table" specified. This makes
   *      various aspects about the connection available, in particular
   *      the connection state.
   *
   *      An NXAST_CT action always puts the packet into an untracked
   *      state for the current processing path.  If "recirc_table" is
   *      set, execution is forked and the packet passes through the
   *      connection tracker.  The specified table's processing path is
   *      able to match on Connection state until the end of the OpenFlow
   *      pipeline or NXAST_CT is called again.
   *
   *   - Connection State:
   *
   *      Multiple packets may be associated with a single connection. Initially,
   *      all connections are uncommitted. The connection state corresponding to
   *      a packet is available in the NXM_NX_CT_STATE field for tracked packets.
   *
   *      Uncommitted connections have no state stored about them. Uncommitted
   *      connections may transition into the committed state by executing
   *      NXAST_CT with the NX_CT_F_COMMIT flag.
   *
   *      Once a connection becomes committed, information may be gathered about
   *      the connection by passing subsequent packets through the connection
   *      tracker, and the state of the connection will be stored beyond the
   *      lifetime of packet processing.
   *
   *      A committed connection always has the directionality of the packet that
   *      caused the connection to be committed in the first place.  This is the
   *      "original direction" of the connection, and the opposite direction is
   *      the "reply direction".  If a connection is already committed, but it is
   *      then decided that the original direction should be the opposite of the
   *      existing connection, NX_CT_F_FORCE flag may be used in addition to
   *      NX_CT_F_COMMIT flag to in effect terminate the existing connection and
   *      start a new one in the current direction.
   *
   *      Connections may transition back into the uncommitted state due to
   *      external timers, or due to the contents of packets that are sent to the
   *      connection tracker. This behaviour is outside of the scope of the
   *      OpenFlow interface.
   *
   * The "zone" specifies a context within which the tracking is done:
   *
   *      The connection tracking zone is a 16-bit number. Each zone is an
   *      independent connection tracking context. The connection state for each
   *      connection is completely separate for each zone, so if a connection
   *      is committed to zone A, then it will remain uncommitted in zone B.
   *      If NXAST_CT is executed with the same zone multiple times, later
   *      executions have no effect.
   *
   *      If 'zone_src' is nonzero, this specifies that the zone should be
   *      sourced from a field zone_src[ofs:ofs+nbits]. The format and semantics
   *      of 'zone_src' and 'zone_ofs_nbits' are similar to those for the
   *      NXAST_REG_LOAD action. The acceptable nxm_header values for 'zone_src'
   *      are the same as the acceptable nxm_header values for the 'src' field of
   *      NXAST_REG_MOVE.
   *
   *      If 'zone_src' is zero, then the value of 'zone_imm' will be used as the
   *      connection tracking zone.
   *
   * The "recirc_table" allows NXM_NX_CT_* fields to become available:
   *
   *      If "recirc_table" has a value other than NX_CT_RECIRC_NONE, then the
   *      packet will be logically cloned prior to executing this action. One
   *      copy will be sent to the connection tracker, then will be re-injected
   *      into the OpenFlow pipeline beginning at the OpenFlow table specified in
   *      this field. When the packet re-enters the pipeline, the NXM_NX_CT_*
   *      fields will be populated. The original instance of the packet will
   *      continue the current actions list. This can be thought of as similar to
   *      the effect of the "output" action: One copy is sent out (in this case,
   *      to the connection tracker), but the current copy continues processing.
   *
   *      It is strongly recommended that this table is later than the current
   *      table, to prevent loops.
   *
   * The "alg" attaches protocol-specific behaviour to this action:
   *
   *      The ALG is a 16-bit number which specifies that additional
   *      processing should be applied to this traffic.
   *
   *      Protocol | Value | Meaning
   *      --------------------------------------------------------------------
   *      None     |     0 | No protocol-specific behaviour.
   *      FTP      |    21 | Parse FTP control connections and observe the
   *               |       | negotiation of related data connections.
   *      Other    | Other | Unsupported protocols.
   *
   *      By way of example, if FTP control connections have this action applied
   *      with the ALG set to FTP (21), then the connection tracker will observe
   *      the negotiation of data connections. This allows the connection
   *      tracker to identify subsequent data connections as "related" to this
   *      existing connection. The "related" flag will be populated in the
   *      NXM_NX_CT_STATE field for such connections if the 'recirc_table' is
   *      specified.
   *
   * Zero or more actions may immediately follow this action. These actions will
   * be executed within the context of the connection tracker, and they require
   * NX_CT_F_COMMIT flag be set.
   */
  struct nx_action_conntrack {
      ovs_be16 type;              /* OFPAT_VENDOR. */
      ovs_be16 len;               /* At least 24. */
      ovs_be32 vendor;            /* NX_VENDOR_ID. */
      ovs_be16 subtype;           /* NXAST_CT. */
      ovs_be16 flags;             /* Zero or more NX_CT_F_* flags.
                                   * Unspecified flag bits must be zero. */
      ovs_be32 zone_src;          /* Connection tracking context. */
      union {
          ovs_be16 zone_ofs_nbits;/* Range to use from source field. */
          ovs_be16 zone_imm;      /* Immediate value for zone. */
      };
      uint8_t recirc_table;       /* Recirculate to a specific table, or
                                     NX_CT_RECIRC_NONE for no recirculation. */
      uint8_t pad[3];             /* Zeroes */
      ovs_be16 alg;               /* Well-known port number for the protocol.
                                   * 0 indicates no ALG is required. */
      /* Followed by a sequence of zero or more OpenFlow actions. The length of
       * these is included in 'len'. */
  };
  OFP_ASSERT(sizeof(struct nx_action_conntrack) == 24);
  
  static enum ofperr
  decode_ct_zone(const struct nx_action_conntrack *nac,
                 struct ofpact_conntrack *out,
                 const struct vl_mff_map *vl_mff_map, uint64_t *tlv_bitmap)
  {
      if (nac->zone_src) {
          enum ofperr error;
  
          out->zone_src.ofs = nxm_decode_ofs(nac->zone_ofs_nbits);
          out->zone_src.n_bits = nxm_decode_n_bits(nac->zone_ofs_nbits);
          error = mf_vl_mff_mf_from_nxm_header(ntohl(nac->zone_src),
                                               vl_mff_map, &out->zone_src.field,
                                               tlv_bitmap);
          if (error) {
              return error;
          }
  
          error = mf_check_src(&out->zone_src, NULL);
          if (error) {
              return error;
          }
  
          if (out->zone_src.n_bits != 16) {
              VLOG_WARN_RL(&rl, "zone n_bits %d not within valid range [16..16]",
                           out->zone_src.n_bits);
              return OFPERR_OFPBAC_BAD_SET_LEN;
          }
      } else {
          out->zone_src.field = NULL;
          out->zone_imm = ntohs(nac->zone_imm);
      }
  
      return 0;
  }
  
  static enum ofperr
  decode_NXAST_RAW_CT(const struct nx_action_conntrack *nac,
                      enum ofp_version ofp_version,
                      const struct vl_mff_map *vl_mff_map, uint64_t *tlv_bitmap,
                      struct ofpbuf *out)
  {
      const size_t ct_offset = ofpacts_pull(out);
      struct ofpact_conntrack *conntrack = ofpact_put_CT(out);
      int error;
  
      conntrack->flags = ntohs(nac->flags);
      if (conntrack->flags & NX_CT_F_FORCE &&
          !(conntrack->flags & NX_CT_F_COMMIT)) {
          error = OFPERR_OFPBAC_BAD_ARGUMENT;
          goto out;
      }
  
      error = decode_ct_zone(nac, conntrack, vl_mff_map, tlv_bitmap);
      if (error) {
          goto out;
      }
      conntrack->recirc_table = nac->recirc_table;
      conntrack->alg = ntohs(nac->alg);
  
      ofpbuf_pull(out, sizeof(*conntrack));
  
      struct ofpbuf openflow = ofpbuf_const_initializer(
          nac + 1, ntohs(nac->len) - sizeof(*nac));
      error = ofpacts_pull_openflow_actions__(&openflow, openflow.size,
                                              ofp_version,
                                              1u << OVSINST_OFPIT11_APPLY_ACTIONS,
                                              out, OFPACT_CT, vl_mff_map,
                                              tlv_bitmap);
      if (error) {
          return error;
      }
  
      conntrack = ofpbuf_push_uninit(out, sizeof(*conntrack));
      out->header = &conntrack->ofpact;
      ofpact_finish_CT(out, &conntrack);
  
      if (conntrack->ofpact.len > sizeof(*conntrack)
          && !(conntrack->flags & NX_CT_F_COMMIT)) {
          const struct ofpact *a;
          size_t ofpacts_len = conntrack->ofpact.len - sizeof(*conntrack);
  
          OFPACT_FOR_EACH (a, conntrack->actions, ofpacts_len) {
              if (a->type != OFPACT_NAT || ofpact_get_NAT(a)->flags
                  || ofpact_get_NAT(a)->range_af != AF_UNSPEC) {
                  VLOG_WARN_RL(&rl, "CT action requires commit flag if actions "
                               "other than NAT without arguments are specified.");
                  error = OFPERR_OFPBAC_BAD_ARGUMENT;
                  goto out;
              }
          }
      }
  
  out:
      ofpbuf_push_uninit(out, ct_offset);
      return error;
  }
  
  static void
  encode_CT(const struct ofpact_conntrack *conntrack,
            enum ofp_version ofp_version, struct ofpbuf *out)
  {
      struct nx_action_conntrack *nac;
      const size_t ofs = out->size;
      size_t len;
  
      nac = put_NXAST_CT(out);
      nac->flags = htons(conntrack->flags);
      if (conntrack->zone_src.field) {
          nac->zone_src = htonl(nxm_header_from_mff(conntrack->zone_src.field));
          nac->zone_ofs_nbits = nxm_encode_ofs_nbits(conntrack->zone_src.ofs,
                                                     conntrack->zone_src.n_bits);
      } else {
          nac->zone_src = htonl(0);
          nac->zone_imm = htons(conntrack->zone_imm);
      }
      nac->recirc_table = conntrack->recirc_table;
      nac->alg = htons(conntrack->alg);
  
      len = ofpacts_put_openflow_actions(conntrack->actions,
                                         ofpact_ct_get_action_len(conntrack),
                                         out, ofp_version);
      len += sizeof(*nac);
      nac = ofpbuf_at(out, ofs, sizeof(*nac));
      nac->len = htons(len);
  }
  
  static char *OVS_WARN_UNUSED_RESULT
  parse_NAT(char *arg, const struct ofpact_parse_params *pp);
  
  /* Parses 'arg' as the argument to a "ct" action, and appends such an
   * action to 'pp->ofpacts'.
   *
   * Returns NULL if successful, otherwise a malloc()'d string describing the
   * error.  The caller is responsible for freeing the returned string. */
  static char * OVS_WARN_UNUSED_RESULT
  parse_CT(char *arg, const struct ofpact_parse_params *pp)
  {
      const size_t ct_offset = ofpacts_pull(pp->ofpacts);
      struct ofpact_conntrack *oc;
      char *error = NULL;
      char *key, *value;
  
      oc = ofpact_put_CT(pp->ofpacts);
      oc->flags = 0;
      oc->recirc_table = NX_CT_RECIRC_NONE;
      while (ofputil_parse_key_value(&arg, &key, &value)) {
          if (!strcmp(key, "commit")) {
              oc->flags |= NX_CT_F_COMMIT;
          } else if (!strcmp(key, "force")) {
              oc->flags |= NX_CT_F_FORCE;
          } else if (!strcmp(key, "table")) {
              if (!ofputil_table_from_string(value, pp->table_map,
                                             &oc->recirc_table)) {
                  error = xasprintf("unknown table %s", value);
              } else if (oc->recirc_table == NX_CT_RECIRC_NONE) {
                  error = xasprintf("invalid table %#"PRIx8, oc->recirc_table);
              }
          } else if (!strcmp(key, "zone")) {
              error = str_to_u16(value, "zone", &oc->zone_imm);
  
              if (error) {
                  free(error);
                  error = mf_parse_subfield(&oc->zone_src, value);
                  if (error) {
                      return error;
                  }
              }
          } else if (!strcmp(key, "alg")) {
              error = str_to_connhelper(value, &oc->alg);
          } else if (!strcmp(key, "nat")) {
              const size_t nat_offset = ofpacts_pull(pp->ofpacts);
  
              error = parse_NAT(value, pp);
              /* Update CT action pointer and length. */
              pp->ofpacts->header = ofpbuf_push_uninit(pp->ofpacts, nat_offset);
              oc = pp->ofpacts->header;
          } else if (!strcmp(key, "exec")) {
              /* Hide existing actions from ofpacts_parse_copy(), so the
               * nesting can be handled transparently. */
              enum ofputil_protocol usable_protocols2;
              const size_t exec_offset = ofpacts_pull(pp->ofpacts);
  
              /* Initializes 'usable_protocol2', fold it back to
               * '*usable_protocols' afterwards, so that we do not lose
               * restrictions already in there. */
              struct ofpact_parse_params pp2 = *pp;
              pp2.usable_protocols = &usable_protocols2;
              error = ofpacts_parse_copy(value, &pp2, false, OFPACT_CT);
              *pp->usable_protocols &= usable_protocols2;
              pp->ofpacts->header = ofpbuf_push_uninit(pp->ofpacts, exec_offset);
              oc = pp->ofpacts->header;
          } else {
              error = xasprintf("invalid argument to \"ct\" action: `%s'", key);
          }
          if (error) {
              break;
          }
      }
      if (!error && oc->flags & NX_CT_F_FORCE && !(oc->flags & NX_CT_F_COMMIT)) {
          error = xasprintf("\"force\" flag requires \"commit\" flag.");
      }
      ofpact_finish_CT(pp->ofpacts, &oc);
      ofpbuf_push_uninit(pp->ofpacts, ct_offset);
      return error;
  }
  
  static void
  format_alg(int port, struct ds *s)
  {
      switch(port) {
      case IPPORT_FTP:
          ds_put_format(s, "%salg=%sftp,", colors.param, colors.end);
          break;
      case IPPORT_TFTP:
          ds_put_format(s, "%salg=%stftp,", colors.param, colors.end);
          break;
      case 0:
          /* Don't print. */
          break;
      default:
          ds_put_format(s, "%salg=%s%d,", colors.param, colors.end, port);
          break;
      }
  }
  
  static void format_NAT(const struct ofpact_nat *,
                         const struct ofpact_format_params *fp);
  
  static void
  format_CT(const struct ofpact_conntrack *a,
            const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%sct(%s", colors.paren, colors.end);
      if (a->flags & NX_CT_F_COMMIT) {
          ds_put_format(fp->s, "%scommit%s,", colors.value, colors.end);
      }
      if (a->flags & NX_CT_F_FORCE) {
          ds_put_format(fp->s, "%sforce%s,", colors.value, colors.end);
      }
      if (a->recirc_table != NX_CT_RECIRC_NONE) {
          ds_put_format(fp->s, "%stable=%s", colors.special, colors.end);
          ofputil_format_table(a->recirc_table, fp->table_map, fp->s);
          ds_put_char(fp->s, ',');
      }
      if (a->zone_src.field) {
          ds_put_format(fp->s, "%szone=%s", colors.param, colors.end);
          mf_format_subfield(&a->zone_src, fp->s);
          ds_put_char(fp->s, ',');
      } else if (a->zone_imm) {
          ds_put_format(fp->s, "%szone=%s%"PRIu16",",
                        colors.param, colors.end, a->zone_imm);
      }
      /* If the first action is a NAT action, format it outside of the 'exec'
       * envelope. */
      const struct ofpact *action = a->actions;
      size_t actions_len = ofpact_ct_get_action_len(a);
      if (actions_len && action->type == OFPACT_NAT) {
          format_NAT(ofpact_get_NAT(action), fp);
          ds_put_char(fp->s, ',');
          actions_len -= OFPACT_ALIGN(action->len);
          action = ofpact_next(action);
      }
      if (actions_len) {
          ds_put_format(fp->s, "%sexec(%s", colors.paren, colors.end);
          ofpacts_format(action, actions_len, fp);
          ds_put_format(fp->s, "%s),%s", colors.paren, colors.end);
      }
      format_alg(a->alg, fp->s);
      ds_chomp(fp->s, ',');
      ds_put_format(fp->s, "%s)%s", colors.paren, colors.end);
  }
  
  static enum ofperr
  check_CT(struct ofpact_conntrack *a, struct ofpact_check_params *cp)
  {
      struct flow *flow = &cp->match->flow;
  
      if (!dl_type_is_ip_any(get_dl_type(flow))
          || (flow->ct_state & CS_INVALID && a->flags & NX_CT_F_COMMIT)
          || (a->alg == IPPORT_FTP && flow->nw_proto != IPPROTO_TCP)
          || (a->alg == IPPORT_TFTP && flow->nw_proto != IPPROTO_UDP)) {
          /* We can't downgrade to OF1.0 and expect inconsistent CT actions
           * be silently discarded.  Instead, datapath flow install fails, so
           * it is better to flag inconsistent CT actions as hard errors. */
          return OFPERR_OFPBAC_MATCH_INCONSISTENT;
      }
  
      if (a->zone_src.field) {
          return mf_check_src(&a->zone_src, cp->match);
      }
  
      return check_subactions(a->actions, ofpact_ct_get_action_len(a), cp);
  }
  
  /* ct_clear action. */
  
  static enum ofperr
  decode_NXAST_RAW_CT_CLEAR(struct ofpbuf *out)
  {
      ofpact_put_CT_CLEAR(out);
      return 0;
  }
  
  static void
  encode_CT_CLEAR(const struct ofpact_null *null OVS_UNUSED,
                  enum ofp_version ofp_version OVS_UNUSED,
                  struct ofpbuf *out)
  {
      put_NXAST_CT_CLEAR(out);
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_CT_CLEAR(char *arg OVS_UNUSED, const struct ofpact_parse_params *pp)
  {
      ofpact_put_CT_CLEAR(pp->ofpacts);
      return NULL;
  }
  
  static void
  format_CT_CLEAR(const struct ofpact_null *a OVS_UNUSED,
                  const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%sct_clear%s", colors.value, colors.end);
  }
  
  static enum ofperr
  check_CT_CLEAR(const struct ofpact_null *a OVS_UNUSED,
                 const struct ofpact_check_params *cp OVS_UNUSED)
  {
      return 0;
  }
  
  /* NAT action. */
  
  /* Which optional fields are present? */
  enum nx_nat_range {
      NX_NAT_RANGE_IPV4_MIN  = 1 << 0, /* ovs_be32 */
      NX_NAT_RANGE_IPV4_MAX  = 1 << 1, /* ovs_be32 */
      NX_NAT_RANGE_IPV6_MIN  = 1 << 2, /* struct in6_addr */
      NX_NAT_RANGE_IPV6_MAX  = 1 << 3, /* struct in6_addr */
      NX_NAT_RANGE_PROTO_MIN = 1 << 4, /* ovs_be16 */
      NX_NAT_RANGE_PROTO_MAX = 1 << 5, /* ovs_be16 */
  };
  
  /* Action structure for NXAST_NAT. */
  struct nx_action_nat {
      ovs_be16 type;              /* OFPAT_VENDOR. */
      ovs_be16 len;               /* At least 16. */
      ovs_be32 vendor;            /* NX_VENDOR_ID. */
      ovs_be16 subtype;           /* NXAST_NAT. */
      uint8_t  pad[2];            /* Must be zero. */
      ovs_be16 flags;             /* Zero or more NX_NAT_F_* flags.
                                   * Unspecified flag bits must be zero. */
      ovs_be16 range_present;     /* NX_NAT_RANGE_* */
      /* Followed by optional parameters as specified by 'range_present' */
  };
  OFP_ASSERT(sizeof(struct nx_action_nat) == 16);
  
  static void
  encode_NAT(const struct ofpact_nat *nat,
             enum ofp_version ofp_version OVS_UNUSED,
             struct ofpbuf *out)
  {
      struct nx_action_nat *nan;
      const size_t ofs = out->size;
      uint16_t range_present = 0;
  
      nan = put_NXAST_NAT(out);
      nan->flags = htons(nat->flags);
      if (nat->range_af == AF_INET) {
          if (nat->range.addr.ipv4.min) {
              ovs_be32 *min = ofpbuf_put_uninit(out, sizeof *min);
              *min = nat->range.addr.ipv4.min;
              range_present |= NX_NAT_RANGE_IPV4_MIN;
          }
          if (nat->range.addr.ipv4.max) {
              ovs_be32 *max = ofpbuf_put_uninit(out, sizeof *max);
              *max = nat->range.addr.ipv4.max;
              range_present |= NX_NAT_RANGE_IPV4_MAX;
          }
      } else if (nat->range_af == AF_INET6) {
          if (!ipv6_mask_is_any(&nat->range.addr.ipv6.min)) {
              struct in6_addr *min = ofpbuf_put_uninit(out, sizeof *min);
              *min = nat->range.addr.ipv6.min;
              range_present |= NX_NAT_RANGE_IPV6_MIN;
          }
          if (!ipv6_mask_is_any(&nat->range.addr.ipv6.max)) {
              struct in6_addr *max = ofpbuf_put_uninit(out, sizeof *max);
              *max = nat->range.addr.ipv6.max;
              range_present |= NX_NAT_RANGE_IPV6_MAX;
          }
      }
      if (nat->range_af != AF_UNSPEC) {
          if (nat->range.proto.min) {
              ovs_be16 *min = ofpbuf_put_uninit(out, sizeof *min);
              *min = htons(nat->range.proto.min);
              range_present |= NX_NAT_RANGE_PROTO_MIN;
          }
          if (nat->range.proto.max) {
              ovs_be16 *max = ofpbuf_put_uninit(out, sizeof *max);
              *max = htons(nat->range.proto.max);
              range_present |= NX_NAT_RANGE_PROTO_MAX;
          }
      }
      pad_ofpat(out, ofs);
      nan = ofpbuf_at(out, ofs, sizeof *nan);
      nan->range_present = htons(range_present);
  }
  
  static enum ofperr
  decode_NXAST_RAW_NAT(const struct nx_action_nat *nan,
                       enum ofp_version ofp_version OVS_UNUSED,
                       struct ofpbuf *out)
  {
      struct ofpact_nat *nat;
      uint16_t range_present = ntohs(nan->range_present);
      const char *opts = (char *)(nan + 1);
      uint16_t len = ntohs(nan->len) - sizeof *nan;
  
      nat = ofpact_put_NAT(out);
      nat->flags = ntohs(nan->flags);
  
      /* Check for unknown or mutually exclusive flags. */
      if ((nat->flags & ~NX_NAT_F_MASK)
          || (nat->flags & NX_NAT_F_SRC && nat->flags & NX_NAT_F_DST)
          || (nat->flags & NX_NAT_F_PROTO_HASH
              && nat->flags & NX_NAT_F_PROTO_RANDOM)) {
          return OFPERR_OFPBAC_BAD_ARGUMENT;
      }
  
  #define NX_NAT_GET_OPT(DST, SRC, LEN, TYPE)                     \
      (LEN >= sizeof(TYPE)                                        \
       ? (memcpy(DST, SRC, sizeof(TYPE)), LEN -= sizeof(TYPE),    \
          SRC += sizeof(TYPE))                                    \
       : NULL)
  
      nat->range_af = AF_UNSPEC;
      if (range_present & NX_NAT_RANGE_IPV4_MIN) {
          if (range_present & (NX_NAT_RANGE_IPV6_MIN | NX_NAT_RANGE_IPV6_MAX)) {
              return OFPERR_OFPBAC_BAD_ARGUMENT;
          }
  
          if (!NX_NAT_GET_OPT(&nat->range.addr.ipv4.min, opts, len, ovs_be32)
              || !nat->range.addr.ipv4.min) {
              return OFPERR_OFPBAC_BAD_ARGUMENT;
          }
  
          nat->range_af = AF_INET;
  
          if (range_present & NX_NAT_RANGE_IPV4_MAX) {
              if (!NX_NAT_GET_OPT(&nat->range.addr.ipv4.max, opts, len,
                                  ovs_be32)) {
                  return OFPERR_OFPBAC_BAD_ARGUMENT;
              }
              if (ntohl(nat->range.addr.ipv4.max)
                  < ntohl(nat->range.addr.ipv4.min)) {
                  return OFPERR_OFPBAC_BAD_ARGUMENT;
              }
          }
      } else if (range_present & NX_NAT_RANGE_IPV4_MAX) {
          return OFPERR_OFPBAC_BAD_ARGUMENT;
      } else if (range_present & NX_NAT_RANGE_IPV6_MIN) {
          if (!NX_NAT_GET_OPT(&nat->range.addr.ipv6.min, opts, len,
                              struct in6_addr)
              || ipv6_mask_is_any(&nat->range.addr.ipv6.min)) {
              return OFPERR_OFPBAC_BAD_ARGUMENT;
          }
  
          nat->range_af = AF_INET6;
  
          if (range_present & NX_NAT_RANGE_IPV6_MAX) {
              if (!NX_NAT_GET_OPT(&nat->range.addr.ipv6.max, opts, len,
                                  struct in6_addr)) {
                  return OFPERR_OFPBAC_BAD_ARGUMENT;
              }
              if (memcmp(&nat->range.addr.ipv6.max, &nat->range.addr.ipv6.min,
                         sizeof(struct in6_addr)) < 0) {
                  return OFPERR_OFPBAC_BAD_ARGUMENT;
              }
          }
      } else if (range_present & NX_NAT_RANGE_IPV6_MAX) {
          return OFPERR_OFPBAC_BAD_ARGUMENT;
      }
  
      if (range_present & NX_NAT_RANGE_PROTO_MIN) {
          ovs_be16 proto;
  
          if (nat->range_af == AF_UNSPEC) {
              return OFPERR_OFPBAC_BAD_ARGUMENT;
          }
          if (!NX_NAT_GET_OPT(&proto, opts, len, ovs_be16) || proto == 0) {
              return OFPERR_OFPBAC_BAD_ARGUMENT;
          }
          nat->range.proto.min = ntohs(proto);
          if (range_present & NX_NAT_RANGE_PROTO_MAX) {
              if (!NX_NAT_GET_OPT(&proto, opts, len, ovs_be16)) {
                  return OFPERR_OFPBAC_BAD_ARGUMENT;
              }
              nat->range.proto.max = ntohs(proto);
              if (nat->range.proto.max < nat->range.proto.min) {
                  return OFPERR_OFPBAC_BAD_ARGUMENT;
              }
          }
      } else if (range_present & NX_NAT_RANGE_PROTO_MAX) {
          return OFPERR_OFPBAC_BAD_ARGUMENT;
      }
  
      return 0;
  }
  
  static void
  format_NAT(const struct ofpact_nat *a, const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%snat%s", colors.paren, colors.end);
  
      if (a->flags & (NX_NAT_F_SRC | NX_NAT_F_DST)) {
          ds_put_format(fp->s, "%s(%s", colors.paren, colors.end);
          ds_put_format(fp->s, a->flags & NX_NAT_F_SRC ? "%ssrc%s" : "%sdst%s",
                        colors.param, colors.end);
  
          if (a->range_af != AF_UNSPEC) {
              ds_put_format(fp->s, "%s=%s", colors.param, colors.end);
  
              if (a->range_af == AF_INET) {
                  ds_put_format(fp->s, IP_FMT, IP_ARGS(a->range.addr.ipv4.min));
  
                  if (a->range.addr.ipv4.max
                      && a->range.addr.ipv4.max != a->range.addr.ipv4.min) {
                      ds_put_format(fp->s, "-"IP_FMT,
                                    IP_ARGS(a->range.addr.ipv4.max));
                  }
              } else if (a->range_af == AF_INET6) {
                  ipv6_format_addr_bracket(&a->range.addr.ipv6.min, fp->s,
                                          a->range.proto.min);
  
                  if (!ipv6_mask_is_any(&a->range.addr.ipv6.max)
                      && memcmp(&a->range.addr.ipv6.max, &a->range.addr.ipv6.min,
                                sizeof(struct in6_addr)) != 0) {
                      ds_put_char(fp->s, '-');
                      ipv6_format_addr_bracket(&a->range.addr.ipv6.max, fp->s,
                                              a->range.proto.min);
                  }
              }
              if (a->range.proto.min) {
                  ds_put_char(fp->s, ':');
                  ds_put_format(fp->s, "%"PRIu16, a->range.proto.min);
  
                  if (a->range.proto.max
                      && a->range.proto.max != a->range.proto.min) {
                      ds_put_format(fp->s, "-%"PRIu16, a->range.proto.max);
                  }
              }
              ds_put_char(fp->s, ',');
  
              if (a->flags & NX_NAT_F_PERSISTENT) {
                  ds_put_format(fp->s, "%spersistent%s,",
                                colors.value, colors.end);
              }
              if (a->flags & NX_NAT_F_PROTO_HASH) {
                  ds_put_format(fp->s, "%shash%s,", colors.value, colors.end);
              }
              if (a->flags & NX_NAT_F_PROTO_RANDOM) {
                  ds_put_format(fp->s, "%srandom%s,", colors.value, colors.end);
              }
          }
          ds_chomp(fp->s, ',');
          ds_put_format(fp->s, "%s)%s", colors.paren, colors.end);
      }
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  str_to_nat_range(const char *s, struct ofpact_nat *on)
  {
      char ipv6_s[IPV6_SCAN_LEN + 1];
      int n = 0;
  
      on->range_af = AF_UNSPEC;
      if (ovs_scan_len(s, &n, IP_SCAN_FMT,
                       IP_SCAN_ARGS(&on->range.addr.ipv4.min))) {
          on->range_af = AF_INET;
  
          if (s[n] == '-') {
              n++;
              if (!ovs_scan_len(s, &n, IP_SCAN_FMT,
                                IP_SCAN_ARGS(&on->range.addr.ipv4.max))
                  || (ntohl(on->range.addr.ipv4.max)
                      < ntohl(on->range.addr.ipv4.min))) {
                  goto error;
              }
          }
      } else if ((ovs_scan_len(s, &n, IPV6_SCAN_FMT, ipv6_s)
                  || ovs_scan_len(s, &n, "["IPV6_SCAN_FMT"]", ipv6_s))
                 && inet_pton(AF_INET6, ipv6_s, &on->range.addr.ipv6.min) == 1) {
          on->range_af = AF_INET6;
  
          if (s[n] == '-') {
              n++;
              if (!(ovs_scan_len(s, &n, IPV6_SCAN_FMT, ipv6_s)
                    || ovs_scan_len(s, &n, "["IPV6_SCAN_FMT"]", ipv6_s))
                  || inet_pton(AF_INET6, ipv6_s, &on->range.addr.ipv6.max) != 1
                  || memcmp(&on->range.addr.ipv6.max, &on->range.addr.ipv6.min,
                            sizeof on->range.addr.ipv6.max) < 0) {
                  goto error;
              }
          }
      }
      if (on->range_af != AF_UNSPEC && s[n] == ':') {
          n++;
          if (!ovs_scan_len(s, &n, "%"SCNu16, &on->range.proto.min)) {
              goto error;
          }
          if (s[n] == '-') {
              n++;
              if (!ovs_scan_len(s, &n, "%"SCNu16, &on->range.proto.max)
                  || on->range.proto.max < on->range.proto.min) {
                  goto error;
              }
          }
      }
      if (strlen(s) != n) {
          return xasprintf("garbage (%s) after nat range \"%s\" (pos: %d)",
                           &s[n], s, n);
      }
      return NULL;
  error:
      return xasprintf("invalid nat range \"%s\"", s);
  }
  
  
  /* Parses 'arg' as the argument to a "nat" action, and appends such an
   * action to 'pp->ofpacts'.
   *
   * Returns NULL if successful, otherwise a malloc()'d string describing the
   * error.  The caller is responsible for freeing the returned string. */
  static char * OVS_WARN_UNUSED_RESULT
  parse_NAT(char *arg, const struct ofpact_parse_params *pp)
  {
      struct ofpact_nat *on = ofpact_put_NAT(pp->ofpacts);
      char *key, *value;
  
      on->flags = 0;
      on->range_af = AF_UNSPEC;
  
      while (ofputil_parse_key_value(&arg, &key, &value)) {
          char *error = NULL;
  
          if (!strcmp(key, "src")) {
              on->flags |= NX_NAT_F_SRC;
              error = str_to_nat_range(value, on);
          } else if (!strcmp(key, "dst")) {
              on->flags |= NX_NAT_F_DST;
              error = str_to_nat_range(value, on);
          } else if (!strcmp(key, "persistent")) {
              on->flags |= NX_NAT_F_PERSISTENT;
          } else if (!strcmp(key, "hash")) {
              on->flags |= NX_NAT_F_PROTO_HASH;
          } else if (!strcmp(key, "random")) {
              on->flags |= NX_NAT_F_PROTO_RANDOM;
          } else {
              error = xasprintf("invalid key \"%s\" in \"nat\" argument",
                                key);
          }
          if (error) {
              return error;
          }
      }
      if (on->flags & NX_NAT_F_SRC && on->flags & NX_NAT_F_DST) {
          return xasprintf("May only specify one of \"src\" or \"dst\".");
      }
      if (!(on->flags & NX_NAT_F_SRC || on->flags & NX_NAT_F_DST)) {
          if (on->flags) {
              return xasprintf("Flags allowed only with \"src\" or \"dst\".");
          }
          if (on->range_af != AF_UNSPEC) {
              return xasprintf("Range allowed only with \"src\" or \"dst\".");
          }
      }
      if (on->flags & NX_NAT_F_PROTO_HASH && on->flags & NX_NAT_F_PROTO_RANDOM) {
          return xasprintf("Both \"hash\" and \"random\" are not allowed.");
      }
  
      return NULL;
  }
  
  static enum ofperr
  check_NAT(const struct ofpact_nat *a, const struct ofpact_check_params *cp)
  {
      ovs_be16 dl_type = get_dl_type(&cp->match->flow);
      if (!dl_type_is_ip_any(dl_type) ||
          (a->range_af == AF_INET && dl_type != htons(ETH_TYPE_IP)) ||
          (a->range_af == AF_INET6 && dl_type != htons(ETH_TYPE_IPV6))) {
          return OFPERR_OFPBAC_MATCH_INCONSISTENT;
      }
      return 0;
  }
  
  /* Truncate output action. */
  struct nx_action_output_trunc {
      ovs_be16 type;              /* OFPAT_VENDOR. */
      ovs_be16 len;               /* At least 16. */
      ovs_be32 vendor;            /* NX_VENDOR_ID. */
      ovs_be16 subtype;           /* NXAST_OUTPUT_TRUNC. */
      ovs_be16 port;              /* Output port */
      ovs_be32 max_len;           /* Truncate packet to size bytes */
  };
  OFP_ASSERT(sizeof(struct nx_action_output_trunc) == 16);
  
  static enum ofperr
  decode_NXAST_RAW_OUTPUT_TRUNC(const struct nx_action_output_trunc *natrc,
                              enum ofp_version ofp_version OVS_UNUSED,
                              struct ofpbuf *out)
  {
      struct ofpact_output_trunc *output_trunc;
  
      output_trunc = ofpact_put_OUTPUT_TRUNC(out);
      output_trunc->max_len = ntohl(natrc->max_len);
      output_trunc->port = u16_to_ofp(ntohs(natrc->port));
  
      if (output_trunc->max_len < ETH_HEADER_LEN) {
          return OFPERR_OFPBAC_BAD_ARGUMENT;
      }
      return 0;
  }
  
  static void
  encode_OUTPUT_TRUNC(const struct ofpact_output_trunc *output_trunc,
                    enum ofp_version ofp_version OVS_UNUSED,
                    struct ofpbuf *out)
  {
      struct nx_action_output_trunc *natrc = put_NXAST_OUTPUT_TRUNC(out);
  
      natrc->max_len = htonl(output_trunc->max_len);
      natrc->port = htons(ofp_to_u16(output_trunc->port));
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_OUTPUT_TRUNC(const char *arg,
                     const struct ofpact_parse_params *pp OVS_UNUSED)
  {
      /* Disable output_trunc parsing.  Expose as output(port=N,max_len=M) and
       * reuse parse_OUTPUT to parse output_trunc action. */
      return xasprintf("unknown action %s", arg);
  }
  
  static void
  format_OUTPUT_TRUNC(const struct ofpact_output_trunc *a,
                      const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%soutput%s(port=", colors.special, colors.end);
      ofputil_format_port(a->port, fp->port_map, fp->s);
      ds_put_format(fp->s, ",max_len=%"PRIu32")", a->max_len);
  }
  
  static enum ofperr
  check_OUTPUT_TRUNC(const struct ofpact_output_trunc *a,
                     const struct ofpact_check_params *cp)
  {
      return ofpact_check_output_port(a->port, cp->max_ports);
  }
  
  /* Meter instruction. */
  
  static void
  encode_METER(const struct ofpact_meter *meter,
               enum ofp_version ofp_version, struct ofpbuf *out)
  {
      if (ofp_version >= OFP13_VERSION) {
          instruction_put_OFPIT13_METER(out)->meter_id = htonl(meter->meter_id);
      }
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_METER(char *arg, const struct ofpact_parse_params *pp)
  {
      *pp->usable_protocols &= OFPUTIL_P_OF13_UP;
      return str_to_u32(arg, &ofpact_put_METER(pp->ofpacts)->meter_id);
  }
  
  static void
  format_METER(const struct ofpact_meter *a,
               const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%smeter:%s%"PRIu32,
                    colors.param, colors.end, a->meter_id);
  }
  
  static enum ofperr
  check_METER(const struct ofpact_meter *a,
              const struct ofpact_check_params *cp OVS_UNUSED)
  {
      uint32_t mid = a->meter_id;
      return mid == 0 || mid > OFPM13_MAX ? OFPERR_OFPMMFC_INVALID_METER : 0;
  }
  
  /* Clear-Actions instruction. */
  
  static void
  encode_CLEAR_ACTIONS(const struct ofpact_null *null OVS_UNUSED,
                       enum ofp_version ofp_version OVS_UNUSED,
                       struct ofpbuf *out OVS_UNUSED)
  {
      if (ofp_version > OFP10_VERSION) {
          instruction_put_OFPIT11_CLEAR_ACTIONS(out);
      }
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_CLEAR_ACTIONS(char *arg OVS_UNUSED, const struct ofpact_parse_params *pp)
  {
      ofpact_put_CLEAR_ACTIONS(pp->ofpacts);
      return NULL;
  }
  
  static void
  format_CLEAR_ACTIONS(const struct ofpact_null *a OVS_UNUSED,
                       const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%sclear_actions%s", colors.value, colors.end);
  }
  
  static enum ofperr
  check_CLEAR_ACTIONS(const struct ofpact_null *a OVS_UNUSED,
                      const struct ofpact_check_params *cp OVS_UNUSED)
  {
      return 0;
  }
  
  /* Write-Actions instruction. */
  
  static void
  encode_WRITE_ACTIONS(const struct ofpact_nest *actions,
                       enum ofp_version ofp_version, struct ofpbuf *out)
  {
      if (ofp_version > OFP10_VERSION) {
          const size_t ofs = out->size;
  
          instruction_put_OFPIT11_WRITE_ACTIONS(out);
          ofpacts_put_openflow_actions(actions->actions,
                                       ofpact_nest_get_action_len(actions),
                                       out, ofp_version);
          ofpacts_update_instruction_actions(out, ofs);
      }
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_WRITE_ACTIONS(char *arg, const struct ofpact_parse_params *pp)
  {
      size_t ofs = ofpacts_pull(pp->ofpacts);
      struct ofpact_nest *on;
      char *error;
  
      /* Add a Write-Actions instruction and then pull it off. */
      ofpact_put(pp->ofpacts, OFPACT_WRITE_ACTIONS, sizeof *on);
      ofpbuf_pull(pp->ofpacts, sizeof *on);
  
      /* Parse nested actions.
       *
       * We pulled off "write-actions" and the previous actions because the
       * OFPACT_WRITE_ACTIONS is only partially constructed: its length is such
       * that it doesn't actually include the nested actions.  That means that
       * ofpacts_parse() would reject them as being part of an Apply-Actions that
       * follows a Write-Actions, which is an invalid order.  */
      error = ofpacts_parse(arg, pp, false, OFPACT_WRITE_ACTIONS);
  
      /* Put the Write-Actions back on and update its length. */
      on = ofpbuf_push_uninit(pp->ofpacts, sizeof *on);
      on->ofpact.len = pp->ofpacts->size;
  
      /* Put any previous actions or instructions back on. */
      ofpbuf_push_uninit(pp->ofpacts, ofs);
  
      return error;
  }
  
  static void
  format_WRITE_ACTIONS(const struct ofpact_nest *a,
                       const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%swrite_actions(%s", colors.paren, colors.end);
      ofpacts_format(a->actions, ofpact_nest_get_action_len(a), fp);
      ds_put_format(fp->s, "%s)%s", colors.paren, colors.end);
  }
  
  static enum ofperr
  check_WRITE_ACTIONS(struct ofpact_nest *a,
                      const struct ofpact_check_params *cp)
  {
      /* Use a temporary copy of 'cp' to avoid updating 'cp->usable_protocols',
       * since we can't check consistency of an action set. */
      struct ofpact_check_params tmp = *cp;
      return ofpacts_check(a->actions, ofpact_nest_get_action_len(a), &tmp);
  }
  
  /* Action structure for NXAST_WRITE_METADATA.
   *
   * Modifies the 'mask' bits of the metadata value. */
  struct nx_action_write_metadata {
      ovs_be16 type;                  /* OFPAT_VENDOR. */
      ovs_be16 len;                   /* Length is 32. */
      ovs_be32 vendor;                /* NX_VENDOR_ID. */
      ovs_be16 subtype;               /* NXAST_WRITE_METADATA. */
      uint8_t zeros[6];               /* Must be zero. */
      ovs_be64 metadata;              /* Metadata register. */
      ovs_be64 mask;                  /* Metadata mask. */
  };
  OFP_ASSERT(sizeof(struct nx_action_write_metadata) == 32);
  
  static enum ofperr
  decode_NXAST_RAW_WRITE_METADATA(const struct nx_action_write_metadata *nawm,
                                  enum ofp_version ofp_version OVS_UNUSED,
                                  struct ofpbuf *out)
  {
      struct ofpact_metadata *om;
  
      if (!is_all_zeros(nawm->zeros, sizeof nawm->zeros)) {
          return OFPERR_NXBRC_MUST_BE_ZERO;
      }
  
      om = ofpact_put_WRITE_METADATA(out);
      om->metadata = nawm->metadata;
      om->mask = nawm->mask;
  
      return 0;
  }
  
  static void
  encode_WRITE_METADATA(const struct ofpact_metadata *metadata,
                        enum ofp_version ofp_version, struct ofpbuf *out)
  {
      if (ofp_version == OFP10_VERSION) {
          struct nx_action_write_metadata *nawm;
  
          nawm = put_NXAST_WRITE_METADATA(out);
          nawm->metadata = metadata->metadata;
          nawm->mask = metadata->mask;
      } else {
          struct ofp11_instruction_write_metadata *oiwm;
  
          oiwm = instruction_put_OFPIT11_WRITE_METADATA(out);
          oiwm->metadata = metadata->metadata;
          oiwm->metadata_mask = metadata->mask;
      }
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_WRITE_METADATA(char *arg, const struct ofpact_parse_params *pp)
  {
      struct ofpact_metadata *om;
      char *mask = strchr(arg, '/');
  
      *pp->usable_protocols &= OFPUTIL_P_NXM_OF11_UP;
  
      om = ofpact_put_WRITE_METADATA(pp->ofpacts);
      if (mask) {
          char *error;
  
          *mask = '\0';
          error = str_to_be64(mask + 1, &om->mask);
          if (error) {
              return error;
          }
      } else {
          om->mask = OVS_BE64_MAX;
      }
  
      return str_to_be64(arg, &om->metadata);
  }
  
  static void
  format_WRITE_METADATA(const struct ofpact_metadata *a,
                        const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%swrite_metadata:%s%#"PRIx64,
                    colors.param, colors.end, ntohll(a->metadata));
      if (a->mask != OVS_BE64_MAX) {
          ds_put_format(fp->s, "/%#"PRIx64, ntohll(a->mask));
      }
  }
  
  static enum ofperr
  check_WRITE_METADATA(const struct ofpact_metadata *a OVS_UNUSED,
                       const struct ofpact_check_params *cp OVS_UNUSED)
  {
      return 0;
  }
  
  /* Goto-Table instruction. */
  
  static void
  encode_GOTO_TABLE(const struct ofpact_goto_table *goto_table,
                    enum ofp_version ofp_version, struct ofpbuf *out)
  {
      if (ofp_version == OFP10_VERSION) {
          struct nx_action_resubmit *nar;
  
          nar = put_NXAST_RESUBMIT_TABLE(out);
          nar->table = goto_table->table_id;
          nar->in_port = htons(ofp_to_u16(OFPP_IN_PORT));
      } else {
          struct ofp11_instruction_goto_table *oigt;
  
          oigt = instruction_put_OFPIT11_GOTO_TABLE(out);
          oigt->table_id = goto_table->table_id;
          memset(oigt->pad, 0, sizeof oigt->pad);
      }
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  parse_GOTO_TABLE(char *arg, const struct ofpact_parse_params *pp)
  {
      struct ofpact_goto_table *ogt = ofpact_put_GOTO_TABLE(pp->ofpacts);
      if (!ofputil_table_from_string(arg, pp->table_map, &ogt->table_id)) {
          return xasprintf("unknown table \"%s\"", arg);
      }
      return NULL;
  }
  
  static void
  format_GOTO_TABLE(const struct ofpact_goto_table *a,
                    const struct ofpact_format_params *fp)
  {
      ds_put_format(fp->s, "%sgoto_table:%s", colors.param, colors.end);
      ofputil_format_table(a->table_id, fp->table_map, fp->s);
  }
  
  static enum ofperr
  check_GOTO_TABLE(const struct ofpact_goto_table *a,
                   const struct ofpact_check_params *cp)
  {
      if ((cp->table_id != 255 && a->table_id <= cp->table_id)
          || (cp->n_tables != 255 && a->table_id >= cp->n_tables)) {
          return OFPERR_OFPBIC_BAD_TABLE_ID;
      }
      return 0;
  }
  
  static void
  log_bad_action(const struct ofp_action_header *actions, size_t actions_len,
                 const struct ofp_action_header *bad_action, enum ofperr error)
  {
      if (!VLOG_DROP_WARN(&rl)) {
          struct ds s;
  
          ds_init(&s);
          ds_put_hex_dump(&s, actions, actions_len, 0, false);
          VLOG_WARN("bad action at offset %#"PRIxPTR" (%s):\n%s",
                    (char *)bad_action - (char *)actions,
                    ofperr_get_name(error), ds_cstr(&s));
          ds_destroy(&s);
      }
  }
  
  static enum ofperr
  ofpacts_decode(const void *actions, size_t actions_len,
                 enum ofp_version ofp_version,
                 const struct vl_mff_map *vl_mff_map,
                 uint64_t *ofpacts_tlv_bitmap, struct ofpbuf *ofpacts)
  {
      struct ofpbuf openflow = ofpbuf_const_initializer(actions, actions_len);
      while (openflow.size) {
          const struct ofp_action_header *action = openflow.data;
          enum ofp_raw_action_type raw;
          enum ofperr error;
          uint64_t arg;
  
          error = ofpact_pull_raw(&openflow, ofp_version, &raw, &arg);
          if (!error) {
              error = ofpact_decode(action, raw, ofp_version, arg, vl_mff_map,
                                    ofpacts_tlv_bitmap, ofpacts);
          }
  
          if (error) {
              log_bad_action(actions, actions_len, action, error);
              return error;
          }
      }
      return 0;
  }
  
  static enum ofperr
  ofpacts_pull_openflow_actions__(struct ofpbuf *openflow,
                                  unsigned int actions_len,
                                  enum ofp_version version,
                                  uint32_t allowed_ovsinsts,
                                  struct ofpbuf *ofpacts,
                                  enum ofpact_type outer_action,
                                  const struct vl_mff_map *vl_mff_map,
                                  uint64_t *ofpacts_tlv_bitmap)
  {
      const struct ofp_action_header *actions;
      enum ofperr error;
  
      if (actions_len % OFP_ACTION_ALIGN != 0) {
          VLOG_WARN_RL(&rl, "OpenFlow message actions length %u is not a "
                       "multiple of %d", actions_len, OFP_ACTION_ALIGN);
          return OFPERR_OFPBRC_BAD_LEN;
      }
  
      actions = ofpbuf_try_pull(openflow, actions_len);
      if (actions == NULL) {
          VLOG_WARN_RL(&rl, "OpenFlow message actions length %u exceeds "
                       "remaining message length (%"PRIu32")",
                       actions_len, openflow->size);
          return OFPERR_OFPBRC_BAD_LEN;
      }
  
      error = ofpacts_decode(actions, actions_len, version, vl_mff_map,
                             ofpacts_tlv_bitmap, ofpacts);
      if (!error) {
          error = ofpacts_verify(ofpacts->data, ofpacts->size, allowed_ovsinsts,
                                 outer_action);
      }
      if (error) {
          ofpbuf_clear(ofpacts);
      }
      return error;
  }
  
  /* Attempts to convert 'actions_len' bytes of OpenFlow actions from the front
   * of 'openflow' into ofpacts.  On success, appends the converted actions to
   * 'ofpacts'; on failure, clears 'ofpacts'.  Returns 0 if successful, otherwise
   * an OpenFlow error.
   *
   * Actions are processed according to their OpenFlow version which
   * is provided in the 'version' parameter.
   *
   * In most places in OpenFlow, actions appear encapsulated in instructions, so
   * you should call ofpacts_pull_openflow_instructions() instead of this
   * function.
   *
   * 'vl_mff_map' and 'ofpacts_tlv_bitmap' are optional. If 'vl_mff_map' is
   * provided, it is used to get variable length mf_fields with configured
   * length in the actions. If an action uses a variable length mf_field,
   * 'ofpacts_tlv_bitmap' is updated accordingly for ref counting. If
   * 'vl_mff_map' is not provided, the default mf_fields with maximum length
   * will be used.
   *
   * The parsed actions are valid generically, but they may not be valid in a
   * specific context.  For example, port numbers up to OFPP_MAX are valid
   * generically, but specific datapaths may only support port numbers in a
   * smaller range.  Use ofpacts_check() to additional check whether actions are
   * valid in a specific context. */
  enum ofperr
  ofpacts_pull_openflow_actions(struct ofpbuf *openflow,
                                unsigned int actions_len,
                                enum ofp_version version,
                                const struct vl_mff_map *vl_mff_map,
                                uint64_t *ofpacts_tlv_bitmap,
                                struct ofpbuf *ofpacts)
  {
      return ofpacts_pull_openflow_actions__(openflow, actions_len, version,
                                             1u << OVSINST_OFPIT11_APPLY_ACTIONS,
                                             ofpacts, 0, vl_mff_map,
                                             ofpacts_tlv_bitmap);
  }
  
  /* OpenFlow 1.1 action sets. */
  
  /* Append ofpact 'a' onto the tail of 'out' */
  static void
  ofpact_copy(struct ofpbuf *out, const struct ofpact *a)
  {
      ofpbuf_put(out, a, OFPACT_ALIGN(a->len));
  }
  
  /* The order in which actions in an action set get executed.  This is only for
   * the actions where only the last instance added is used. */
  #define ACTION_SET_ORDER                        \
      SLOT(OFPACT_STRIP_VLAN)                     \
      SLOT(OFPACT_POP_MPLS)                       \
      SLOT(OFPACT_DECAP)                          \
      SLOT(OFPACT_ENCAP)                          \
      SLOT(OFPACT_PUSH_MPLS)                      \
      SLOT(OFPACT_PUSH_VLAN)                      \
      SLOT(OFPACT_DEC_TTL)                        \
      SLOT(OFPACT_DEC_MPLS_TTL)                   \
      SLOT(OFPACT_DEC_NSH_TTL)
  
  /* Priority for "final actions" in an action set.  An action set only gets
   * executed at all if at least one of these actions is present.  If more than
   * one is present, then only the one later in this list is executed (and if
   * more than one of a given type, the one later in the action set). */
  #define ACTION_SET_FINAL_PRIORITY               \
      FINAL(OFPACT_CT)                            \
      FINAL(OFPACT_CT_CLEAR)                      \
      FINAL(OFPACT_RESUBMIT)                      \
      FINAL(OFPACT_OUTPUT)                        \
      FINAL(OFPACT_GROUP)
  
  enum action_set_class {
      /* Actions that individually can usefully appear only once in an action
       * set.  If they do appear more than once, then only the last instance is
       * honored. */
  #define SLOT(OFPACT) ACTION_SLOT_##OFPACT,
      ACTION_SET_ORDER
  #undef SLOT
  
      /* Final actions. */
  #define FINAL(OFPACT) ACTION_SLOT_##OFPACT,
      ACTION_SET_FINAL_PRIORITY
  #undef FINAL
  
      /* Actions that can appear in an action set more than once and are executed
       * in order. */
      ACTION_SLOT_SET_OR_MOVE,
  
      /* Actions that shouldn't appear in the action set at all. */
      ACTION_SLOT_INVALID
  };
  
  /* Count the action set slots. */
  #define SLOT(OFPACT) +1
  enum { N_ACTION_SLOTS = ACTION_SET_ORDER };
  #undef SLOT
  
  static enum action_set_class
  action_set_classify(const struct ofpact *a)
  {
      switch (a->type) {
  #define SLOT(OFPACT) case OFPACT: return ACTION_SLOT_##OFPACT;
          ACTION_SET_ORDER
  #undef SLOT
  
  #define FINAL(OFPACT) case OFPACT: return ACTION_SLOT_##OFPACT;
          ACTION_SET_FINAL_PRIORITY
  #undef FINAL
  
      case OFPACT_SET_FIELD:
      case OFPACT_REG_MOVE:
      case OFPACT_SET_ETH_DST:
      case OFPACT_SET_ETH_SRC:
      case OFPACT_SET_IP_DSCP:
      case OFPACT_SET_IP_ECN:
      case OFPACT_SET_IP_TTL:
      case OFPACT_SET_IPV4_DST:
      case OFPACT_SET_IPV4_SRC:
      case OFPACT_SET_L4_DST_PORT:
      case OFPACT_SET_L4_SRC_PORT:
      case OFPACT_SET_MPLS_LABEL:
      case OFPACT_SET_MPLS_TC:
      case OFPACT_SET_MPLS_TTL:
      case OFPACT_SET_QUEUE:
      case OFPACT_SET_TUNNEL:
      case OFPACT_SET_VLAN_PCP:
      case OFPACT_SET_VLAN_VID:
          return ACTION_SLOT_SET_OR_MOVE;
  
      case OFPACT_BUNDLE:
      case OFPACT_CLEAR_ACTIONS:
      case OFPACT_CLONE:
      case OFPACT_NAT:
      case OFPACT_CONTROLLER:
      case OFPACT_ENQUEUE:
      case OFPACT_EXIT:
      case OFPACT_UNROLL_XLATE:
      case OFPACT_FIN_TIMEOUT:
      case OFPACT_GOTO_TABLE:
      case OFPACT_LEARN:
      case OFPACT_CONJUNCTION:
      case OFPACT_METER:
      case OFPACT_MULTIPATH:
      case OFPACT_NOTE:
      case OFPACT_OUTPUT_REG:
      case OFPACT_OUTPUT_TRUNC:
      case OFPACT_POP_QUEUE:
      case OFPACT_SAMPLE:
      case OFPACT_STACK_POP:
      case OFPACT_STACK_PUSH:
      case OFPACT_WRITE_ACTIONS:
      case OFPACT_WRITE_METADATA:
      case OFPACT_DEBUG_RECIRC:
      case OFPACT_DEBUG_SLOW:
          return ACTION_SLOT_INVALID;
  
      default:
          OVS_NOT_REACHED();
      }
  }
  
  /* True if an action is allowed in the action set.
   * False otherwise. */
  static bool
  ofpact_is_allowed_in_actions_set(const struct ofpact *a)
  {
      return action_set_classify(a) != ACTION_SLOT_INVALID;
  }
  
  /* Reads 'action_set', which contains ofpacts accumulated by
   * OFPACT_WRITE_ACTIONS instructions, and writes equivalent actions to be
   * executed directly into 'action_list'.  (These names correspond to the
   * "Action Set" and "Action List" terms used in OpenFlow 1.1+.)
   *
   * In general this involves appending the last instance of each action that is
   * admissible in the action set in the order described in the OpenFlow
   * specification.
   *
   * Exceptions:
   * + output action is only appended if no group action was present in 'in'.
   * + As a simplification all set actions are copied in the order the are
   *   provided in 'in' as many set actions applied to a field has the same
   *   affect as only applying the last action that sets a field and
   *   duplicates are removed by do_xlate_actions().
   *   This has an unwanted side-effect of compsoting multiple
   *   LOAD_REG actions that touch different regions of the same field. */
  void
  ofpacts_execute_action_set(struct ofpbuf *action_list,
                             const struct ofpbuf *action_set)
  {
      const struct ofpact *slots[N_ACTION_SLOTS] = {NULL, };
  
      struct ofpbuf set_or_move;
      ofpbuf_init(&set_or_move, 0);
  
      const struct ofpact *final_action = NULL;
      enum action_set_class final_class = 0;
  
      const struct ofpact *cursor;
      OFPACT_FOR_EACH (cursor, action_set->data, action_set->size) {
          int class = action_set_classify(cursor);
          if (class < N_ACTION_SLOTS) {
              slots[class] = cursor;
          } else if (class < ACTION_SLOT_SET_OR_MOVE) {
              if (class >= final_class) {
                  final_action = cursor;
                  final_class = class;
              }
          } else if (class == ACTION_SLOT_SET_OR_MOVE) {
              ofpact_copy(&set_or_move, cursor);
          } else {
              ovs_assert(class == ACTION_SLOT_INVALID);
          }
      }
  
      if (final_action) {
          for (int i = 0; i < N_ACTION_SLOTS; i++) {
              if (slots[i]) {
                  ofpact_copy(action_list, slots[i]);
              }
          }
          ofpbuf_put(action_list, set_or_move.data, set_or_move.size);
          ofpact_copy(action_list, final_action);
      }
      ofpbuf_uninit(&set_or_move);
  }
  
  
  static enum ofperr
  ofpacts_decode_for_action_set(const struct ofp_action_header *in,
                                size_t n_in, enum ofp_version version,
                                const struct vl_mff_map *vl_mff_map,
                                uint64_t *ofpacts_tlv_bitmap,
                                struct ofpbuf *out)
  {
      enum ofperr error;
      struct ofpact *a;
      size_t start = out->size;
  
      error = ofpacts_decode(in, n_in, version, vl_mff_map, ofpacts_tlv_bitmap,
                             out);
  
      if (error) {
          return error;
      }
  
      OFPACT_FOR_EACH (a, ofpact_end(out->data, start), out->size - start) {
          if (!ofpact_is_allowed_in_actions_set(a)) {
              VLOG_WARN_RL(&rl, "disallowed action in action set");
              return OFPERR_OFPBAC_BAD_TYPE;
          }
      }
  
      return 0;
  }
  
  /* OpenFlow 1.1 instructions. */
  
  struct instruction_type_info {
      enum ovs_instruction_type type;
      const char *name;
  };
  
  static const struct instruction_type_info inst_info[] = {
  #define DEFINE_INST(ENUM, STRUCT, EXTENSIBLE, NAME)    {OVSINST_##ENUM, NAME},
  OVS_INSTRUCTIONS
  #undef DEFINE_INST
  };
  
  const char *
  ovs_instruction_name_from_type(enum ovs_instruction_type type)
  {
      return type < ARRAY_SIZE(inst_info) ? inst_info[type].name : NULL;
  }
  
  int
  ovs_instruction_type_from_name(const char *name)
  {
      const struct instruction_type_info *p;
      for (p = inst_info; p < &inst_info[ARRAY_SIZE(inst_info)]; p++) {
          if (!strcasecmp(name, p->name)) {
              return p->type;
          }
      }
      return -1;
  }
  
  enum ovs_instruction_type
  ovs_instruction_type_from_ofpact_type(enum ofpact_type type)
  {
      switch (type) {
      case OFPACT_METER:
          return OVSINST_OFPIT13_METER;
      case OFPACT_CLEAR_ACTIONS:
          return OVSINST_OFPIT11_CLEAR_ACTIONS;
      case OFPACT_WRITE_ACTIONS:
          return OVSINST_OFPIT11_WRITE_ACTIONS;
      case OFPACT_WRITE_METADATA:
          return OVSINST_OFPIT11_WRITE_METADATA;
      case OFPACT_GOTO_TABLE:
          return OVSINST_OFPIT11_GOTO_TABLE;
      case OFPACT_OUTPUT:
      case OFPACT_GROUP:
      case OFPACT_CLONE:
      case OFPACT_CONTROLLER:
      case OFPACT_ENQUEUE:
      case OFPACT_OUTPUT_REG:
      case OFPACT_OUTPUT_TRUNC:
      case OFPACT_BUNDLE:
      case OFPACT_SET_VLAN_VID:
      case OFPACT_SET_VLAN_PCP:
      case OFPACT_STRIP_VLAN:
      case OFPACT_PUSH_VLAN:
      case OFPACT_SET_ETH_SRC:
      case OFPACT_SET_ETH_DST:
      case OFPACT_SET_IPV4_SRC:
      case OFPACT_SET_IPV4_DST:
      case OFPACT_SET_IP_DSCP:
      case OFPACT_SET_IP_ECN:
      case OFPACT_SET_IP_TTL:
      case OFPACT_SET_L4_SRC_PORT:
      case OFPACT_SET_L4_DST_PORT:
      case OFPACT_REG_MOVE:
      case OFPACT_SET_FIELD:
      case OFPACT_STACK_PUSH:
      case OFPACT_STACK_POP:
      case OFPACT_DEC_TTL:
      case OFPACT_SET_MPLS_LABEL:
      case OFPACT_SET_MPLS_TC:
      case OFPACT_SET_MPLS_TTL:
      case OFPACT_DEC_MPLS_TTL:
      case OFPACT_PUSH_MPLS:
      case OFPACT_POP_MPLS:
      case OFPACT_SET_TUNNEL:
      case OFPACT_SET_QUEUE:
      case OFPACT_POP_QUEUE:
      case OFPACT_FIN_TIMEOUT:
      case OFPACT_RESUBMIT:
      case OFPACT_LEARN:
      case OFPACT_CONJUNCTION:
      case OFPACT_MULTIPATH:
      case OFPACT_NOTE:
      case OFPACT_EXIT:
      case OFPACT_UNROLL_XLATE:
      case OFPACT_SAMPLE:
      case OFPACT_DEBUG_RECIRC:
      case OFPACT_DEBUG_SLOW:
      case OFPACT_CT:
      case OFPACT_CT_CLEAR:
      case OFPACT_NAT:
      case OFPACT_ENCAP:
      case OFPACT_DECAP:
      case OFPACT_DEC_NSH_TTL:
      default:
          return OVSINST_OFPIT11_APPLY_ACTIONS;
      }
  }
  
  enum ofperr
  ovs_instruction_type_from_inst_type(enum ovs_instruction_type *instruction_type,
                                      const uint16_t inst_type)
  {
      switch (inst_type) {
  
  #define DEFINE_INST(ENUM, STRUCT, EXTENSIBLE, NAME) \
      case ENUM:                                      \
          *instruction_type = OVSINST_##ENUM;         \
          return 0;
  OVS_INSTRUCTIONS
  #undef DEFINE_INST
  
      default:
          return OFPERR_OFPBIC_UNKNOWN_INST;
      }
  }
  
  /* Two-way translation between OVS's internal "OVSINST_*" representation of
   * instructions and the "OFPIT_*" representation used in OpenFlow. */
  struct ovsinst_map {
      enum ovs_instruction_type ovsinst; /* Internal name for instruction. */
      int ofpit;                         /* OFPIT_* number from OpenFlow spec. */
  };
  
  static const struct ovsinst_map *
  get_ovsinst_map(enum ofp_version version)
  {
      /* OpenFlow 1.1 and 1.2 instructions. */
      static const struct ovsinst_map of11[] = {
          { OVSINST_OFPIT11_GOTO_TABLE, 1 },
          { OVSINST_OFPIT11_WRITE_METADATA, 2 },
          { OVSINST_OFPIT11_WRITE_ACTIONS, 3 },
          { OVSINST_OFPIT11_APPLY_ACTIONS, 4 },
          { OVSINST_OFPIT11_CLEAR_ACTIONS, 5 },
          { 0, -1 },
      };
  
      /* OpenFlow 1.3+ instructions. */
      static const struct ovsinst_map of13[] = {
          { OVSINST_OFPIT11_GOTO_TABLE, 1 },
          { OVSINST_OFPIT11_WRITE_METADATA, 2 },
          { OVSINST_OFPIT11_WRITE_ACTIONS, 3 },
          { OVSINST_OFPIT11_APPLY_ACTIONS, 4 },
          { OVSINST_OFPIT11_CLEAR_ACTIONS, 5 },
          { OVSINST_OFPIT13_METER, 6 },
          { 0, -1 },
      };
  
      return version < OFP13_VERSION ? of11 : of13;
  }
  
  /* Converts 'ovsinst_bitmap', a bitmap whose bits correspond to OVSINST_*
   * values, into a bitmap of instructions suitable for OpenFlow 'version'
   * (OFP11_VERSION or later), and returns the result. */
  ovs_be32
  ovsinst_bitmap_to_openflow(uint32_t ovsinst_bitmap, enum ofp_version version)
  {
      uint32_t ofpit_bitmap = 0;
      const struct ovsinst_map *x;
  
      for (x = get_ovsinst_map(version); x->ofpit >= 0; x++) {
          if (ovsinst_bitmap & (1u << x->ovsinst)) {
              ofpit_bitmap |= 1u << x->ofpit;
          }
      }
      return htonl(ofpit_bitmap);
  }
  
  /* Converts 'ofpit_bitmap', a bitmap of instructions from an OpenFlow message
   * with the given 'version' (OFP11_VERSION or later) into a bitmap whose bits
   * correspond to OVSINST_* values, and returns the result. */
  uint32_t
  ovsinst_bitmap_from_openflow(ovs_be32 ofpit_bitmap, enum ofp_version version)
  {
      uint32_t ovsinst_bitmap = 0;
      const struct ovsinst_map *x;
  
      for (x = get_ovsinst_map(version); x->ofpit >= 0; x++) {
          if (ofpit_bitmap & htonl(1u << x->ofpit)) {
              ovsinst_bitmap |= 1u << x->ovsinst;
          }
      }
      return ovsinst_bitmap;
  }
  
  static inline struct ofp11_instruction *
  instruction_next(const struct ofp11_instruction *inst)
  {
      return ((struct ofp11_instruction *) (void *)
              ((uint8_t *) inst + ntohs(inst->len)));
  }
  
  static inline bool
  instruction_is_valid(const struct ofp11_instruction *inst,
                       size_t n_instructions)
  {
      uint16_t len = ntohs(inst->len);
      return (!(len % OFP11_INSTRUCTION_ALIGN)
              && len >= sizeof *inst
              && len / sizeof *inst <= n_instructions);
  }
  
  /* This macro is careful to check for instructions with bad lengths. */
  #define INSTRUCTION_FOR_EACH(ITER, LEFT, INSTRUCTIONS, N_INSTRUCTIONS)  \
      for ((ITER) = (INSTRUCTIONS), (LEFT) = (N_INSTRUCTIONS);            \
           (LEFT) > 0 && instruction_is_valid(ITER, LEFT);                \
           ((LEFT) -= (ntohs((ITER)->len)                                 \
                       / sizeof(struct ofp11_instruction)),               \
            (ITER) = instruction_next(ITER)))
  
  static enum ofperr
  decode_openflow11_instruction(const struct ofp11_instruction *inst,
                                enum ovs_instruction_type *type)
  {
      uint16_t len = ntohs(inst->len);
  
      switch (inst->type) {
      case CONSTANT_HTONS(OFPIT11_EXPERIMENTER):
          return OFPERR_OFPBIC_BAD_EXPERIMENTER;
  
  #define DEFINE_INST(ENUM, STRUCT, EXTENSIBLE, NAME)     \
          case CONSTANT_HTONS(ENUM):                      \
              if (EXTENSIBLE                              \
                  ? len >= sizeof(struct STRUCT)          \
                  : len == sizeof(struct STRUCT)) {       \
                  *type = OVSINST_##ENUM;                 \
                  return 0;                               \
              } else {                                    \
                  return OFPERR_OFPBIC_BAD_LEN;           \
              }
  OVS_INSTRUCTIONS
  #undef DEFINE_INST
  
      default:
          return OFPERR_OFPBIC_UNKNOWN_INST;
      }
  }
  
  static enum ofperr
  decode_openflow11_instructions(const struct ofp11_instruction insts[],
                                 size_t n_insts,
                                 const struct ofp11_instruction *out[])
  {
      const struct ofp11_instruction *inst;
      size_t left;
  
      memset(out, 0, N_OVS_INSTRUCTIONS * sizeof *out);
      INSTRUCTION_FOR_EACH (inst, left, insts, n_insts) {
          enum ovs_instruction_type type;
          enum ofperr error;
  
          error = decode_openflow11_instruction(inst, &type);
          if (error) {
              return error;
          }
  
          if (out[type]) {
              return OFPERR_OFPBIC_DUP_INST;
          }
          out[type] = inst;
      }
  
      if (left) {
          VLOG_WARN_RL(&rl, "bad instruction format at offset %"PRIuSIZE,
                       (n_insts - left) * sizeof *inst);
          return OFPERR_OFPBIC_BAD_LEN;
      }
      return 0;
  }
  
  static void
  get_actions_from_instruction(const struct ofp11_instruction *inst,
                               const struct ofp_action_header **actions,
                               size_t *actions_len)
  {
      *actions = ALIGNED_CAST(const struct ofp_action_header *, inst + 1);
      *actions_len = ntohs(inst->len) - sizeof *inst;
  }
  
  enum ofperr
  ofpacts_pull_openflow_instructions(struct ofpbuf *openflow,
                                     unsigned int instructions_len,
                                     enum ofp_version version,
                                     const struct vl_mff_map *vl_mff_map,
                                     uint64_t *ofpacts_tlv_bitmap,
                                     struct ofpbuf *ofpacts)
  {
      const struct ofp11_instruction *instructions;
      const struct ofp11_instruction *insts[N_OVS_INSTRUCTIONS];
      enum ofperr error;
  
      ofpbuf_clear(ofpacts);
      if (version == OFP10_VERSION) {
          return ofpacts_pull_openflow_actions__(openflow, instructions_len,
                                                 version,
                                                 (1u << N_OVS_INSTRUCTIONS) - 1,
                                                 ofpacts, 0, vl_mff_map,
                                                 ofpacts_tlv_bitmap);
      }
  
      if (instructions_len % OFP11_INSTRUCTION_ALIGN != 0) {
          VLOG_WARN_RL(&rl, "OpenFlow message instructions length %u is not a "
                       "multiple of %d",
                       instructions_len, OFP11_INSTRUCTION_ALIGN);
          error = OFPERR_OFPBIC_BAD_LEN;
          goto exit;
      }
  
      instructions = ofpbuf_try_pull(openflow, instructions_len);
      if (instructions == NULL) {
          VLOG_WARN_RL(&rl, "OpenFlow message instructions length %u exceeds "
                       "remaining message length (%"PRIu32")",
                       instructions_len, openflow->size);
          error = OFPERR_OFPBIC_BAD_LEN;
          goto exit;
      }
  
      error = decode_openflow11_instructions(
          instructions, instructions_len / OFP11_INSTRUCTION_ALIGN,
          insts);
      if (error) {
          goto exit;
      }
  
      if (insts[OVSINST_OFPIT13_METER]) {
          const struct ofp13_instruction_meter *oim;
          struct ofpact_meter *om;
  
          oim = ALIGNED_CAST(const struct ofp13_instruction_meter *,
                             insts[OVSINST_OFPIT13_METER]);
  
          om = ofpact_put_METER(ofpacts);
          om->meter_id = ntohl(oim->meter_id);
          om->provider_meter_id = UINT32_MAX; /* No provider meter ID. */
      }
      if (insts[OVSINST_OFPIT11_APPLY_ACTIONS]) {
          const struct ofp_action_header *actions;
          size_t actions_len;
  
          get_actions_from_instruction(insts[OVSINST_OFPIT11_APPLY_ACTIONS],
                                       &actions, &actions_len);
          error = ofpacts_decode(actions, actions_len, version, vl_mff_map,
                                 ofpacts_tlv_bitmap, ofpacts);
          if (error) {
              goto exit;
          }
      }
      if (insts[OVSINST_OFPIT11_CLEAR_ACTIONS]) {
          instruction_get_OFPIT11_CLEAR_ACTIONS(
              insts[OVSINST_OFPIT11_CLEAR_ACTIONS]);
          ofpact_put_CLEAR_ACTIONS(ofpacts);
      }
      if (insts[OVSINST_OFPIT11_WRITE_ACTIONS]) {
          struct ofpact_nest *on;
          const struct ofp_action_header *actions;
          size_t actions_len;
          size_t start = ofpacts->size;
          ofpact_put(ofpacts, OFPACT_WRITE_ACTIONS,
                     offsetof(struct ofpact_nest, actions));
          get_actions_from_instruction(insts[OVSINST_OFPIT11_WRITE_ACTIONS],
                                       &actions, &actions_len);
          error = ofpacts_decode_for_action_set(actions, actions_len,
                                                version, vl_mff_map,
                                                ofpacts_tlv_bitmap, ofpacts);
          if (error) {
              goto exit;
          }
          on = ofpbuf_at_assert(ofpacts, start, sizeof *on);
          on->ofpact.len = ofpacts->size - start;
      }
      if (insts[OVSINST_OFPIT11_WRITE_METADATA]) {
          const struct ofp11_instruction_write_metadata *oiwm;
          struct ofpact_metadata *om;
  
          oiwm = ALIGNED_CAST(const struct ofp11_instruction_write_metadata *,
                              insts[OVSINST_OFPIT11_WRITE_METADATA]);
  
          om = ofpact_put_WRITE_METADATA(ofpacts);
          om->metadata = oiwm->metadata;
          om->mask = oiwm->metadata_mask;
      }
      if (insts[OVSINST_OFPIT11_GOTO_TABLE]) {
          const struct ofp11_instruction_goto_table *oigt;
          struct ofpact_goto_table *ogt;
  
          oigt = instruction_get_OFPIT11_GOTO_TABLE(
              insts[OVSINST_OFPIT11_GOTO_TABLE]);
          ogt = ofpact_put_GOTO_TABLE(ofpacts);
          ogt->table_id = oigt->table_id;
      }
  
      error = ofpacts_verify(ofpacts->data, ofpacts->size,
                             (1u << N_OVS_INSTRUCTIONS) - 1, 0);
  exit:
      if (error) {
          ofpbuf_clear(ofpacts);
      }
      return error;
  }
  
  /* Update the length of the instruction that begins at offset 'ofs' within
   * 'openflow' and contains nested actions that extend to the end of 'openflow'.
   * If the instruction contains no nested actions, deletes it entirely. */
  static void
  ofpacts_update_instruction_actions(struct ofpbuf *openflow, size_t ofs)
  {
      struct ofp11_instruction_actions *oia;
  
      oia = ofpbuf_at_assert(openflow, ofs, sizeof *oia);
      if (openflow->size > ofs + sizeof *oia) {
          oia->len = htons(openflow->size - ofs);
      } else {
          openflow->size = ofs;
      }
  }
  
  /* Checks that 'port' is a valid output port for OFPACT_OUTPUT, given that the
   * switch will never have more than 'max_ports' ports.  Returns 0 if 'port' is
   * valid, otherwise an OpenFlow error code. */
  enum ofperr
  ofpact_check_output_port(ofp_port_t port, ofp_port_t max_ports)
  {
      switch (port) {
      case OFPP_IN_PORT:
      case OFPP_TABLE:
      case OFPP_NORMAL:
      case OFPP_FLOOD:
      case OFPP_ALL:
      case OFPP_CONTROLLER:
      case OFPP_LOCAL:
          return 0;
  
      case OFPP_NONE:
          return OFPERR_OFPBAC_BAD_OUT_PORT;
  
      default:
          if (ofp_to_u16(port) < ofp_to_u16(max_ports)) {
              return 0;
          }
          return OFPERR_OFPBAC_BAD_OUT_PORT;
      }
  }
  
  /* Removes the protocols that require consistency between match and actions
   * (that's everything but OpenFlow 1.0) from '*usable_protocols'.
   *
   * (An example of an inconsistency between match and actions is a flow that
   * does not match on an MPLS Ethertype but has an action that pops an MPLS
   * label.) */
  static void
  inconsistent_match(enum ofputil_protocol *usable_protocols)
  {
      *usable_protocols &= OFPUTIL_P_OF10_ANY;
  }
  
  /* May modify flow->packet_type, flow->dl_type, flow->nw_proto and
   * flow->vlan_tci, caller must restore them.
   *
   * Modifies some actions, filling in fields that could not be properly set
   * without context. */
  static enum ofperr
  ofpact_check__(struct ofpact *a, struct ofpact_check_params *cp)
  {
      switch (a->type) {
  #define OFPACT(ENUM, STRUCT, MEMBER, NAME)                  \
          case OFPACT_##ENUM:                                 \
              return check_##ENUM(ofpact_get_##ENUM(a), cp);
          OFPACTS
  #undef OFPACT
      default:
          OVS_NOT_REACHED();
      }
  }
  
  /* Checks that the 'ofpacts_len' bytes of actions in 'ofpacts' are
   * appropriate for a packet with the prerequisites satisfied by 'flow' in a
   * switch with no more than 'max_ports' ports.
   *
   * If 'ofpacts' and 'flow' are inconsistent with one another, un-sets in
   * '*usable_protocols' the protocols that forbid the inconsistency.  (An
   * example of an inconsistency between match and actions is a flow that does
   * not match on an MPLS Ethertype but has an action that pops an MPLS label.)
   *
   * May annotate ofpacts with information gathered from the 'match'.
   *
   * May temporarily modify 'match', but restores the changes before
   * returning. */
  enum ofperr
  ofpacts_check(struct ofpact ofpacts[], size_t ofpacts_len,
                struct ofpact_check_params *cp)
  {
      /* Save fields that might temporarily be modified. */
      struct flow *flow = &cp->match->flow;
      ovs_be32 packet_type = flow->packet_type;
      ovs_be16 dl_type = flow->dl_type;
      uint8_t nw_proto = flow->nw_proto;
      union flow_vlan_hdr vlans[FLOW_MAX_VLAN_HEADERS];
      memcpy(vlans, flow->vlans, sizeof vlans);
  
      /* Check all the actions. */
      cp->usable_protocols = OFPUTIL_P_ANY;
      enum ofperr error = 0;
      struct ofpact *a;
      OFPACT_FOR_EACH (a, ofpacts, ofpacts_len) {
          error = ofpact_check__(a, cp);
          if (error) {
              break;
          }
      }
  
      /* Restore fields that may have been modified. */
      flow->packet_type = packet_type;
      flow->dl_type = dl_type;
      memcpy(flow->vlans, vlans, sizeof vlans);
      flow->nw_proto = nw_proto;
  
      return error;
  }
  
  /* Like ofpacts_check(), but reports inconsistencies as
   * OFPERR_OFPBAC_MATCH_INCONSISTENT rather than clearing bits. */
  enum ofperr
  ofpacts_check_consistency(struct ofpact ofpacts[], size_t ofpacts_len,
                            enum ofputil_protocol needed_protocols,
                            struct ofpact_check_params *cp)
  {
      enum ofperr error = ofpacts_check(ofpacts, ofpacts_len, cp);
      if (!error && needed_protocols & ~cp->usable_protocols) {
          return OFPERR_OFPBAC_MATCH_INCONSISTENT;
      }
      return error;
  }
  
  /* Returns the destination field that 'ofpact' would write to, or NULL
   * if the action would not write to an mf_field. */
  const struct mf_field *
  ofpact_get_mf_dst(const struct ofpact *ofpact)
  {
      if (ofpact->type == OFPACT_SET_FIELD) {
          const struct ofpact_set_field *orl;
  
          orl = CONTAINER_OF(ofpact, struct ofpact_set_field, ofpact);
          return orl->field;
      } else if (ofpact->type == OFPACT_REG_MOVE) {
          const struct ofpact_reg_move *orm;
  
          orm = CONTAINER_OF(ofpact, struct ofpact_reg_move, ofpact);
          return orm->dst.field;
      }
  
      return NULL;
  }
  
  static enum ofperr
  unsupported_nesting(enum ofpact_type action, enum ofpact_type outer_action)
  {
      VLOG_WARN("%s action doesn't support nested action %s",
                ofpact_name(outer_action), ofpact_name(action));
      return OFPERR_OFPBAC_BAD_ARGUMENT;
  }
  
  static bool
  field_requires_ct(enum mf_field_id field)
  {
      return field == MFF_CT_MARK || field == MFF_CT_LABEL;
  }
  
  /* Apply nesting constraints for actions */
  static enum ofperr
  ofpacts_verify_nested(const struct ofpact *a, enum ofpact_type outer_action)
  {
      const struct mf_field *field = ofpact_get_mf_dst(a);
  
      if (field && field_requires_ct(field->id) && outer_action != OFPACT_CT) {
          VLOG_WARN("cannot set CT fields outside of ct action");
          return OFPERR_OFPBAC_BAD_SET_ARGUMENT;
      }
      if (a->type == OFPACT_NAT) {
          if (outer_action != OFPACT_CT) {
              VLOG_WARN("Cannot have NAT action outside of \"ct\" action");
              return OFPERR_OFPBAC_BAD_SET_ARGUMENT;
          }
          return 0;
      }
  
      if (outer_action) {
          ovs_assert(outer_action == OFPACT_WRITE_ACTIONS
                     || outer_action == OFPACT_CT);
  
          if (outer_action == OFPACT_CT) {
              if (!field) {
                  return unsupported_nesting(a->type, outer_action);
              } else if (!field_requires_ct(field->id)) {
                  VLOG_WARN("%s action doesn't support nested modification "
                            "of %s", ofpact_name(outer_action), field->name);
                  return OFPERR_OFPBAC_BAD_ARGUMENT;
              }
          }
      }
  
      return 0;
  }
  
  /* Verifies that the 'ofpacts_len' bytes of actions in 'ofpacts' are in the
   * appropriate order as defined by the OpenFlow spec and as required by Open
   * vSwitch.
   *
   * 'allowed_ovsinsts' is a bitmap of OVSINST_* values, in which 1-bits indicate
   * instructions that are allowed within 'ofpacts[]'.
   *
   * If 'outer_action' is not zero, it specifies that the actions are nested
   * within another action of type 'outer_action'. */
  static enum ofperr
  ofpacts_verify(const struct ofpact ofpacts[], size_t ofpacts_len,
                 uint32_t allowed_ovsinsts, enum ofpact_type outer_action)
  {
      const struct ofpact *a;
      enum ovs_instruction_type inst;
  
      inst = OVSINST_OFPIT13_METER;
      OFPACT_FOR_EACH (a, ofpacts, ofpacts_len) {
          enum ovs_instruction_type next;
          enum ofperr error;
  
          if (a->type == OFPACT_CONJUNCTION) {
              OFPACT_FOR_EACH (a, ofpacts, ofpacts_len) {
                  if (a->type != OFPACT_CONJUNCTION && a->type != OFPACT_NOTE) {
                      VLOG_WARN("\"conjunction\" actions may be used along with "
                                "\"note\" but not any other kind of action "
                                "(such as the \"%s\" action used here)",
                                ofpact_name(a->type));
                      return OFPERR_NXBAC_BAD_CONJUNCTION;
                  }
              }
              return 0;
          }
  
          error = ofpacts_verify_nested(a, outer_action);
          if (error) {
              return error;
          }
  
          next = ovs_instruction_type_from_ofpact_type(a->type);
          if (a > ofpacts
              && (inst == OVSINST_OFPIT11_APPLY_ACTIONS
                  ? next < inst
                  : next <= inst)) {
              const char *name = ovs_instruction_name_from_type(inst);
              const char *next_name = ovs_instruction_name_from_type(next);
  
              if (next == inst) {
                  VLOG_WARN("duplicate %s instruction not allowed, for OpenFlow "
                            "1.1+ compatibility", name);
              } else {
                  VLOG_WARN("invalid instruction ordering: %s must appear "
                            "before %s, for OpenFlow 1.1+ compatibility",
                            next_name, name);
              }
              return OFPERR_OFPBAC_UNSUPPORTED_ORDER;
          }
          if (!((1u << next) & allowed_ovsinsts)) {
              const char *name = ovs_instruction_name_from_type(next);
  
              VLOG_WARN("%s instruction not allowed here", name);
              return OFPERR_OFPBIC_UNSUP_INST;
          }
  
          inst = next;
      }
  
      return 0;
  }
  
  /* Converting ofpacts to OpenFlow. */
  
  static void
  encode_ofpact(const struct ofpact *a, enum ofp_version ofp_version,
                struct ofpbuf *out)
  {
      switch (a->type) {
  #define OFPACT(ENUM, STRUCT, MEMBER, NAME)                              \
          case OFPACT_##ENUM:                                             \
              encode_##ENUM(ofpact_get_##ENUM(a), ofp_version, out);      \
              return;
          OFPACTS
  #undef OFPACT
      default:
          OVS_NOT_REACHED();
      }
  }
  
  /* Converts the 'ofpacts_len' bytes of ofpacts in 'ofpacts' into OpenFlow
   * actions in 'openflow', appending the actions to any existing data in
   * 'openflow'. */
  size_t
  ofpacts_put_openflow_actions(const struct ofpact ofpacts[], size_t ofpacts_len,
                               struct ofpbuf *openflow,
                               enum ofp_version ofp_version)
  {
      const struct ofpact *a;
      size_t start_size = openflow->size;
  
      OFPACT_FOR_EACH (a, ofpacts, ofpacts_len) {
          encode_ofpact(a, ofp_version, openflow);
      }
      return openflow->size - start_size;
  }
  
  static enum ovs_instruction_type
  ofpact_is_apply_actions(const struct ofpact *a)
  {
      return (ovs_instruction_type_from_ofpact_type(a->type)
              == OVSINST_OFPIT11_APPLY_ACTIONS);
  }
  
  void
  ofpacts_put_openflow_instructions(const struct ofpact ofpacts[],
                                    size_t ofpacts_len,
                                    struct ofpbuf *openflow,
                                    enum ofp_version ofp_version)
  {
      const struct ofpact *end = ofpact_end(ofpacts, ofpacts_len);
      const struct ofpact *a;
  
      if (ofp_version == OFP10_VERSION) {
          ofpacts_put_openflow_actions(ofpacts, ofpacts_len, openflow,
                                       ofp_version);
          return;
      }
  
      a = ofpacts;
      while (a < end) {
          if (ofpact_is_apply_actions(a)) {
              size_t ofs = openflow->size;
  
              instruction_put_OFPIT11_APPLY_ACTIONS(openflow);
              do {
                  encode_ofpact(a, ofp_version, openflow);
                  a = ofpact_next(a);
              } while (a < end && ofpact_is_apply_actions(a));
              ofpacts_update_instruction_actions(openflow, ofs);
          } else {
              encode_ofpact(a, ofp_version, openflow);
              a = ofpact_next(a);
          }
      }
  }
  
  /* Sets of supported actions. */
  
  /* Two-way translation between OVS's internal "OFPACT_*" representation of
   * actions and the "OFPAT_*" representation used in some OpenFlow version.
   * (OFPAT_* numbering varies from one OpenFlow version to another, so a given
   * instance is specific to one OpenFlow version.) */
  struct ofpact_map {
      enum ofpact_type ofpact;    /* Internal name for action type. */
      int ofpat;                  /* OFPAT_* number from OpenFlow spec. */
  };
  
  static const struct ofpact_map *
  get_ofpact_map(enum ofp_version version)
  {
      /* OpenFlow 1.0 actions. */
      static const struct ofpact_map of10[] = {
          { OFPACT_OUTPUT, 0 },
          { OFPACT_SET_VLAN_VID, 1 },
          { OFPACT_SET_VLAN_PCP, 2 },
          { OFPACT_STRIP_VLAN, 3 },
          { OFPACT_SET_ETH_SRC, 4 },
          { OFPACT_SET_ETH_DST, 5 },
          { OFPACT_SET_IPV4_SRC, 6 },
          { OFPACT_SET_IPV4_DST, 7 },
          { OFPACT_SET_IP_DSCP, 8 },
          { OFPACT_SET_L4_SRC_PORT, 9 },
          { OFPACT_SET_L4_DST_PORT, 10 },
          { OFPACT_ENQUEUE, 11 },
          { 0, -1 },
      };
  
      /* OpenFlow 1.1 actions. */
      static const struct ofpact_map of11[] = {
          { OFPACT_OUTPUT, 0 },
          { OFPACT_SET_VLAN_VID, 1 },
          { OFPACT_SET_VLAN_PCP, 2 },
          { OFPACT_SET_ETH_SRC, 3 },
          { OFPACT_SET_ETH_DST, 4 },
          { OFPACT_SET_IPV4_SRC, 5 },
          { OFPACT_SET_IPV4_DST, 6 },
          { OFPACT_SET_IP_DSCP, 7 },
          { OFPACT_SET_IP_ECN, 8 },
          { OFPACT_SET_L4_SRC_PORT, 9 },
          { OFPACT_SET_L4_DST_PORT, 10 },
          /* OFPAT_COPY_TTL_OUT (11) not supported. */
          /* OFPAT_COPY_TTL_IN (12) not supported. */
          { OFPACT_SET_MPLS_LABEL, 13 },
          { OFPACT_SET_MPLS_TC, 14 },
          { OFPACT_SET_MPLS_TTL, 15 },
          { OFPACT_DEC_MPLS_TTL, 16 },
          { OFPACT_PUSH_VLAN, 17 },
          { OFPACT_STRIP_VLAN, 18 },
          { OFPACT_PUSH_MPLS, 19 },
          { OFPACT_POP_MPLS, 20 },
          { OFPACT_SET_QUEUE, 21 },
          { OFPACT_GROUP, 22 },
          { OFPACT_SET_IP_TTL, 23 },
          { OFPACT_DEC_TTL, 24 },
          { 0, -1 },
      };
  
      /* OpenFlow 1.2, 1.3, and 1.4 actions. */
      static const struct ofpact_map of12[] = {
          { OFPACT_OUTPUT, 0 },
          /* OFPAT_COPY_TTL_OUT (11) not supported. */
          /* OFPAT_COPY_TTL_IN (12) not supported. */
          { OFPACT_SET_MPLS_TTL, 15 },
          { OFPACT_DEC_MPLS_TTL, 16 },
          { OFPACT_PUSH_VLAN, 17 },
          { OFPACT_STRIP_VLAN, 18 },
          { OFPACT_PUSH_MPLS, 19 },
          { OFPACT_POP_MPLS, 20 },
          { OFPACT_SET_QUEUE, 21 },
          { OFPACT_GROUP, 22 },
          { OFPACT_SET_IP_TTL, 23 },
          { OFPACT_DEC_TTL, 24 },
          { OFPACT_SET_FIELD, 25 },
          /* OF1.3+ OFPAT_PUSH_PBB (26) not supported. */
          /* OF1.3+ OFPAT_POP_PBB (27) not supported. */
          { 0, -1 },
      };
  
      switch (version) {
      case OFP10_VERSION:
          return of10;
  
      case OFP11_VERSION:
          return of11;
  
      case OFP12_VERSION:
      case OFP13_VERSION:
      case OFP14_VERSION:
      case OFP15_VERSION:
      case OFP16_VERSION:
      default:
          return of12;
      }
  }
  
  /* Converts 'ofpacts_bitmap', a bitmap whose bits correspond to OFPACT_*
   * values, into a bitmap of actions suitable for OpenFlow 'version', and
   * returns the result. */
  ovs_be32
  ofpact_bitmap_to_openflow(uint64_t ofpacts_bitmap, enum ofp_version version)
  {
      uint32_t openflow_bitmap = 0;
      const struct ofpact_map *x;
  
      for (x = get_ofpact_map(version); x->ofpat >= 0; x++) {
          if (ofpacts_bitmap & (UINT64_C(1) << x->ofpact)) {
              openflow_bitmap |= 1u << x->ofpat;
          }
      }
      return htonl(openflow_bitmap);
  }
  
  /* Converts 'ofpat_bitmap', a bitmap of actions from an OpenFlow message with
   * the given 'version' into a bitmap whose bits correspond to OFPACT_* values,
   * and returns the result. */
  uint64_t
  ofpact_bitmap_from_openflow(ovs_be32 ofpat_bitmap, enum ofp_version version)
  {
      uint64_t ofpact_bitmap = 0;
      const struct ofpact_map *x;
  
      for (x = get_ofpact_map(version); x->ofpat >= 0; x++) {
          if (ofpat_bitmap & htonl(1u << x->ofpat)) {
              ofpact_bitmap |= UINT64_C(1) << x->ofpact;
          }
      }
      return ofpact_bitmap;
  }
  
  /* Appends to 's' a string representation of the set of OFPACT_* represented
   * by 'ofpacts_bitmap'. */
  void
  ofpact_bitmap_format(uint64_t ofpacts_bitmap, struct ds *s)
  {
      if (!ofpacts_bitmap) {
          ds_put_cstr(s, "<none>");
      } else {
          while (ofpacts_bitmap) {
              ds_put_format(s, "%s ",
                            ofpact_name(rightmost_1bit_idx(ofpacts_bitmap)));
              ofpacts_bitmap = zero_rightmost_1bit(ofpacts_bitmap);
          }
          ds_chomp(s, ' ');
      }
  }
  
  /* Returns true if 'action' outputs to 'port', false otherwise. */
  static bool
  ofpact_outputs_to_port(const struct ofpact *ofpact, ofp_port_t port)
  {
      switch (ofpact->type) {
      case OFPACT_OUTPUT:
          return ofpact_get_OUTPUT(ofpact)->port == port;
      case OFPACT_ENQUEUE:
          return ofpact_get_ENQUEUE(ofpact)->port == port;
      case OFPACT_CONTROLLER:
          return port == OFPP_CONTROLLER;
  
      case OFPACT_OUTPUT_REG:
      case OFPACT_OUTPUT_TRUNC:
      case OFPACT_BUNDLE:
      case OFPACT_SET_VLAN_VID:
      case OFPACT_SET_VLAN_PCP:
      case OFPACT_STRIP_VLAN:
      case OFPACT_PUSH_VLAN:
      case OFPACT_SET_ETH_SRC:
      case OFPACT_SET_ETH_DST:
      case OFPACT_SET_IPV4_SRC:
      case OFPACT_SET_IPV4_DST:
      case OFPACT_SET_IP_DSCP:
      case OFPACT_SET_IP_ECN:
      case OFPACT_SET_IP_TTL:
      case OFPACT_SET_L4_SRC_PORT:
      case OFPACT_SET_L4_DST_PORT:
      case OFPACT_REG_MOVE:
      case OFPACT_SET_FIELD:
      case OFPACT_STACK_PUSH:
      case OFPACT_STACK_POP:
      case OFPACT_DEC_TTL:
      case OFPACT_SET_MPLS_LABEL:
      case OFPACT_SET_MPLS_TC:
      case OFPACT_SET_MPLS_TTL:
      case OFPACT_DEC_MPLS_TTL:
      case OFPACT_SET_TUNNEL:
      case OFPACT_WRITE_METADATA:
      case OFPACT_SET_QUEUE:
      case OFPACT_POP_QUEUE:
      case OFPACT_FIN_TIMEOUT:
      case OFPACT_RESUBMIT:
      case OFPACT_LEARN:
      case OFPACT_CONJUNCTION:
      case OFPACT_MULTIPATH:
      case OFPACT_NOTE:
      case OFPACT_EXIT:
      case OFPACT_UNROLL_XLATE:
      case OFPACT_PUSH_MPLS:
      case OFPACT_POP_MPLS:
      case OFPACT_SAMPLE:
      case OFPACT_CLEAR_ACTIONS:
      case OFPACT_CLONE:
      case OFPACT_WRITE_ACTIONS:
      case OFPACT_GOTO_TABLE:
      case OFPACT_METER:
      case OFPACT_GROUP:
      case OFPACT_DEBUG_RECIRC:
      case OFPACT_DEBUG_SLOW:
      case OFPACT_CT:
      case OFPACT_CT_CLEAR:
      case OFPACT_NAT:
      case OFPACT_ENCAP:
      case OFPACT_DECAP:
      case OFPACT_DEC_NSH_TTL:
      default:
          return false;
      }
  }
  
  /* Returns true if any action in the 'ofpacts_len' bytes of 'ofpacts' outputs
   * to 'port', false otherwise. */
  bool
  ofpacts_output_to_port(const struct ofpact *ofpacts, size_t ofpacts_len,
                         ofp_port_t port)
  {
      const struct ofpact *a;
  
      OFPACT_FOR_EACH_FLATTENED (a, ofpacts, ofpacts_len) {
          if (ofpact_outputs_to_port(a, port)) {
              return true;
          }
      }
  
      return false;
  }
  
  /* Returns true if any action in the 'ofpacts_len' bytes of 'ofpacts' outputs
   * to 'group', false otherwise. */
  bool
  ofpacts_output_to_group(const struct ofpact *ofpacts, size_t ofpacts_len,
                          uint32_t group_id)
  {
      const struct ofpact *a;
  
      OFPACT_FOR_EACH_FLATTENED (a, ofpacts, ofpacts_len) {
          if (a->type == OFPACT_GROUP
              && ofpact_get_GROUP(a)->group_id == group_id) {
              return true;
          }
      }
  
      return false;
  }
  
  /* Returns true if the 'a_len' bytes of actions in 'a' and the 'b_len' bytes of
   * actions in 'b' are bytewise identical. */
  bool
  ofpacts_equal(const struct ofpact *a, size_t a_len,
                const struct ofpact *b, size_t b_len)
  {
      return a_len == b_len && !memcmp(a, b, a_len);
  }
  
  /* Returns true if the 'a_len' bytes of actions in 'a' and the 'b_len' bytes of
   * actions in 'b' are identical when formatted as strings.  (Converting actions
   * to string form suppresses some rarely meaningful differences, such as the
   * 'compat' member of actions.) */
  bool
  ofpacts_equal_stringwise(const struct ofpact *a, size_t a_len,
                           const struct ofpact *b, size_t b_len)
  {
      struct ds a_s = DS_EMPTY_INITIALIZER;
      struct ofpact_format_params a_fp = { .s = &a_s };
      ofpacts_format(a, a_len, &a_fp);
  
      struct ds b_s = DS_EMPTY_INITIALIZER;
      struct ofpact_format_params b_fp = { .s = &b_s };
      ofpacts_format(b, b_len, &b_fp);
  
      bool equal = !strcmp(ds_cstr(&a_s), ds_cstr(&b_s));
  
      ds_destroy(&a_s);
      ds_destroy(&b_s);
  
      return equal;
  }
  
  /* Finds the OFPACT_METER action, if any, in the 'ofpacts_len' bytes of
   * 'ofpacts'.  If found, returns its meter ID; if not, returns 0.
   *
   * This function relies on the order of 'ofpacts' being correct (as checked by
   * ofpacts_verify()). */
  uint32_t
  ofpacts_get_meter(const struct ofpact ofpacts[], size_t ofpacts_len)
  {
      const struct ofpact *a;
  
      OFPACT_FOR_EACH (a, ofpacts, ofpacts_len) {
          enum ovs_instruction_type inst;
  
          inst = ovs_instruction_type_from_ofpact_type(a->type);
          if (a->type == OFPACT_METER) {
              return ofpact_get_METER(a)->meter_id;
          } else if (inst > OVSINST_OFPIT13_METER) {
              break;
          }
      }
  
      return 0;
  }
  
  /* Formatting ofpacts. */
  
  static void
  ofpact_format(const struct ofpact *a,
                const struct ofpact_format_params *fp)
  {
      switch (a->type) {
  #define OFPACT(ENUM, STRUCT, MEMBER, NAME)                              \
          case OFPACT_##ENUM:                                             \
              format_##ENUM(ALIGNED_CAST(const struct STRUCT *, a), fp);  \
              break;
          OFPACTS
  #undef OFPACT
      default:
          OVS_NOT_REACHED();
      }
  }
  
  /* Appends a string representing the 'ofpacts_len' bytes of ofpacts in
   * 'ofpacts' to 'fp->s'.  If 'port_map' is nonnull, uses it to translate port
   * numbers to names in output. */
  void
  ofpacts_format(const struct ofpact *ofpacts, size_t ofpacts_len,
                 const struct ofpact_format_params *fp)
  {
      if (!ofpacts_len) {
          ds_put_format(fp->s, "%sdrop%s", colors.drop, colors.end);
      } else {
          const struct ofpact *a;
  
          OFPACT_FOR_EACH (a, ofpacts, ofpacts_len) {
              if (a != ofpacts) {
                  ds_put_char(fp->s, ',');
              }
  
              ofpact_format(a, fp);
          }
      }
  }
  
  /* Internal use by helpers. */
  
  /* Implementation of ofpact_put_<ENUM>(). */
  void *
  ofpact_put(struct ofpbuf *ofpacts, enum ofpact_type type, size_t len)
  {
      struct ofpact *ofpact;
  
      ofpacts->header = ofpbuf_put_uninit(ofpacts, len);
      ofpact = ofpacts->header;
      ofpact_init(ofpact, type, len);
      return ofpact;
  }
  
  /* Implementation of ofpact_init_<ENUM>(). */
  void
  ofpact_init(struct ofpact *ofpact, enum ofpact_type type, size_t len)
  {
      memset(ofpact, 0, len);
      ofpact->type = type;
      ofpact->raw = -1;
      ofpact->len = len;
  }
  
  /* Implementation of ofpact_finish_<ENUM>().
   *
   * Finishes composing a variable-length action (begun using
   * ofpact_put_<NAME>()), by padding the action to a multiple of OFPACT_ALIGNTO
   * bytes and updating its embedded length field.  See the large comment near
   * the end of ofp-actions.h for more information.
   *
   * May reallocate 'ofpacts'. Callers should consider updating their 'ofpact'
   * pointer to the return value of this function. */
  void *
  ofpact_finish(struct ofpbuf *ofpacts, struct ofpact *ofpact)
  {
      ptrdiff_t len;
  
      ovs_assert(ofpact == ofpacts->header);
      len = (char *) ofpbuf_tail(ofpacts) - (char *) ofpact;
      ovs_assert(len > 0 && len <= UINT16_MAX);
      ofpact->len = len;
      ofpbuf_padto(ofpacts, OFPACT_ALIGN(ofpacts->size));
  
      return ofpacts->header;
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  ofpact_parse(enum ofpact_type type, char *value,
               const struct ofpact_parse_params *pp)
  {
      switch (type) {
  #define OFPACT(ENUM, STRUCT, MEMBER, NAME)                              \
          case OFPACT_##ENUM:                                             \
              return parse_##ENUM(value, pp);
          OFPACTS
  #undef OFPACT
      default:
          OVS_NOT_REACHED();
      }
  }
  
  static bool
  ofpact_type_from_name(const char *name, enum ofpact_type *type)
  {
  #define OFPACT(ENUM, STRUCT, MEMBER, NAME)                            \
      if (!strcasecmp(name, NAME)) {                                    \
          *type = OFPACT_##ENUM;                                          \
          return true;                                                    \
      }
      OFPACTS
  #undef OFPACT
  
      return false;
  }
  
  /* Parses 'str' as a series of instructions, and appends them to 'ofpacts'.
   *
   * Returns NULL if successful, otherwise a malloc()'d string describing the
   * error.  The caller is responsible for freeing the returned string.
   *
   * If 'outer_action' is specified, indicates that the actions being parsed
   * are nested within another action of the type specified in 'outer_action'. */
  static char * OVS_WARN_UNUSED_RESULT
  ofpacts_parse__(char *str, const struct ofpact_parse_params *pp,
                  bool allow_instructions, enum ofpact_type outer_action)
  {
      int prev_inst = -1;
      enum ofperr retval;
      char *key, *value;
      bool drop = false;
      char *pos;
  
      pos = str;
      while (ofputil_parse_key_value(&pos, &key, &value)) {
          enum ovs_instruction_type inst = OVSINST_OFPIT11_APPLY_ACTIONS;
          enum ofpact_type type;
          char *error = NULL;
          ofp_port_t port;
  
          if (ofpact_type_from_name(key, &type)) {
              error = ofpact_parse(type, value, pp);
              inst = ovs_instruction_type_from_ofpact_type(type);
          } else if (!strcasecmp(key, "mod_vlan_vid")) {
              error = parse_set_vlan_vid(value, true, pp);
          } else if (!strcasecmp(key, "mod_vlan_pcp")) {
              error = parse_set_vlan_pcp(value, true, pp);
          } else if (!strcasecmp(key, "set_nw_ttl")) {
              error = parse_SET_IP_TTL(value, pp);
          } else if (!strcasecmp(key, "pop_vlan")) {
              error = parse_pop_vlan(pp);
          } else if (!strcasecmp(key, "set_tunnel64")) {
              error = parse_set_tunnel(value, NXAST_RAW_SET_TUNNEL64, pp);
          } else if (!strcasecmp(key, "load")) {
              error = parse_reg_load(value, pp);
          } else if (!strcasecmp(key, "bundle_load")) {
              error = parse_bundle_load(value, pp);
          } else if (!strcasecmp(key, "drop")) {
              drop = true;
          } else if (!strcasecmp(key, "apply_actions")) {
              return xstrdup("apply_actions is the default instruction");
          } else if (ofputil_port_from_string(key, pp->port_map, &port)) {
              ofpact_put_OUTPUT(pp->ofpacts)->port = port;
          } else {
              return xasprintf("unknown action %s", key);
          }
          if (error) {
              return error;
          }
  
          if (inst != OVSINST_OFPIT11_APPLY_ACTIONS) {
              if (!allow_instructions) {
                  return xasprintf("only actions are allowed here (not "
                                   "instruction %s)",
                                   ovs_instruction_name_from_type(inst));
              }
              if (inst == prev_inst) {
                  return xasprintf("instruction %s may be specified only once",
                                   ovs_instruction_name_from_type(inst));
              }
          }
          if (prev_inst != -1 && inst < prev_inst) {
              return xasprintf("instruction %s must be specified before %s",
                               ovs_instruction_name_from_type(inst),
                               ovs_instruction_name_from_type(prev_inst));
          }
          prev_inst = inst;
      }
  
      if (drop && pp->ofpacts->size) {
          return xstrdup("\"drop\" must not be accompanied by any other action "
                         "or instruction");
      }
  
      retval = ofpacts_verify(pp->ofpacts->data, pp->ofpacts->size,
                              (allow_instructions
                               ? (1u << N_OVS_INSTRUCTIONS) - 1
                               : 1u << OVSINST_OFPIT11_APPLY_ACTIONS),
                              outer_action);
      if (retval) {
          return xstrdup("Incorrect instruction ordering");
      }
  
      return NULL;
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  ofpacts_parse(char *str, const struct ofpact_parse_params *pp,
                bool allow_instructions, enum ofpact_type outer_action)
  {
      uint32_t orig_size = pp->ofpacts->size;
      char *error = ofpacts_parse__(str, pp, allow_instructions, outer_action);
      if (error) {
          pp->ofpacts->size = orig_size;
      }
      return error;
  }
  
  static char * OVS_WARN_UNUSED_RESULT
  ofpacts_parse_copy(const char *s_, const struct ofpact_parse_params *pp,
                     bool allow_instructions, enum ofpact_type outer_action)
  {
      char *error, *s;
  
      *pp->usable_protocols = OFPUTIL_P_ANY;
  
      s = xstrdup(s_);
      error = ofpacts_parse(s, pp, allow_instructions, outer_action);
      free(s);
  
      return error;
  }
  
  /* Parses 's' as a set of OpenFlow actions and appends the actions to
   * 'ofpacts'. 'outer_action', if nonzero, specifies that 's' contains actions
   * that are nested within the action of type 'outer_action'.
   *
   * Returns NULL if successful, otherwise a malloc()'d string describing the
   * error.  The caller is responsible for freeing the returned string. */
  char * OVS_WARN_UNUSED_RESULT
  ofpacts_parse_actions(const char *s, const struct ofpact_parse_params *pp)
  {
      return ofpacts_parse_copy(s, pp, false, 0);
  }
  
  /* Parses 's' as a set of OpenFlow instructions and appends the instructions to
   * 'ofpacts'.
   *
   * Returns NULL if successful, otherwise a malloc()'d string describing the
   * error.  The caller is responsible for freeing the returned string. */
  char * OVS_WARN_UNUSED_RESULT
  ofpacts_parse_instructions(const char *s, const struct ofpact_parse_params *pp)
  {
      return ofpacts_parse_copy(s, pp, true, 0);
  }
  
  const char *
  ofpact_name(enum ofpact_type type)
  {
      switch (type) {
  #define OFPACT(ENUM, STRUCT, MEMBER, NAME) case OFPACT_##ENUM: return NAME;
          OFPACTS
  #undef OFPACT
      }
      return "<unknown>";
  }
  
  /* Low-level action decoding and encoding functions. */
  
  /* Everything needed to identify a particular OpenFlow action. */
  struct ofpact_hdrs {
      uint32_t vendor;              /* 0 if standard, otherwise a vendor code. */
      uint16_t type;                /* Type if standard, otherwise subtype. */
      uint8_t ofp_version;          /* From ofp_header. */
  };
  
  /* Information about a particular OpenFlow action. */
  struct ofpact_raw_instance {
      /* The action's identity. */
      struct ofpact_hdrs hdrs;
      enum ofp_raw_action_type raw;
  
      /* Looking up the action. */
      struct hmap_node decode_node; /* Based on 'hdrs'. */
      struct hmap_node encode_node; /* Based on 'raw' + 'hdrs.ofp_version'. */
  
      /* The action's encoded size.
       *
       * If this action is fixed-length, 'min_length' == 'max_length'.
       * If it is variable length, then 'max_length' is ROUND_DOWN(UINT16_MAX,
       * OFP_ACTION_ALIGN) == 65528. */
      unsigned short int min_length;
      unsigned short int max_length;
  
      /* For actions with a simple integer numeric argument, 'arg_ofs' is the
       * offset of that argument from the beginning of the action and 'arg_len'
       * its length, both in bytes.
       *
       * For actions that take other forms, these are both zero. */
      unsigned short int arg_ofs;
      unsigned short int arg_len;
  
      /* The name of the action, e.g. "OFPAT_OUTPUT" or "NXAST_RESUBMIT". */
      const char *name;
  
      /* If this action is deprecated, a human-readable string with a brief
       * explanation. */
      const char *deprecation;
  };
  
  /* Action header. */
  struct ofp_action_header {
      /* The meaning of other values of 'type' generally depends on the OpenFlow
       * version (see enum ofp_raw_action_type).
       *
       * Across all OpenFlow versions, OFPAT_VENDOR indicates that 'vendor'
       * designates an OpenFlow vendor ID and that the remainder of the action
       * structure has a vendor-defined meaning.
       */
  #define OFPAT_VENDOR 0xffff
      ovs_be16 type;
  
      /* Always a multiple of 8. */
      ovs_be16 len;
  
      /* For type == OFPAT_VENDOR only, this is a vendor ID, e.g. NX_VENDOR_ID or
       * ONF_VENDOR_ID.  Other 'type's use this space for some other purpose. */
      ovs_be32 vendor;
  };
  OFP_ASSERT(sizeof(struct ofp_action_header) == 8);
  
  static bool
  ofpact_hdrs_equal(const struct ofpact_hdrs *a,
                    const struct ofpact_hdrs *b)
  {
      return (a->vendor == b->vendor
              && a->type == b->type
              && a->ofp_version == b->ofp_version);
  }
  
  static uint32_t
  ofpact_hdrs_hash(const struct ofpact_hdrs *hdrs)
  {
      return hash_2words(hdrs->vendor,
                         ((uint32_t) hdrs->type << 16) | hdrs->ofp_version);
  }
  
  #include "ofp-actions.inc2"
  
  static struct hmap *
  ofpact_decode_hmap(void)
  {
      static struct ovsthread_once once = OVSTHREAD_ONCE_INITIALIZER;
      static struct hmap hmap;
  
      if (ovsthread_once_start(&once)) {
          struct ofpact_raw_instance *inst;
  
          hmap_init(&hmap);
          for (inst = all_raw_instances;
               inst < &all_raw_instances[ARRAY_SIZE(all_raw_instances)];
               inst++) {
              hmap_insert(&hmap, &inst->decode_node,
                          ofpact_hdrs_hash(&inst->hdrs));
          }
          ovsthread_once_done(&once);
      }
      return &hmap;
  }
  
  static struct hmap *
  ofpact_encode_hmap(void)
  {
      static struct ovsthread_once once = OVSTHREAD_ONCE_INITIALIZER;
      static struct hmap hmap;
  
      if (ovsthread_once_start(&once)) {
          struct ofpact_raw_instance *inst;
  
          hmap_init(&hmap);
          for (inst = all_raw_instances;
               inst < &all_raw_instances[ARRAY_SIZE(all_raw_instances)];
               inst++) {
              hmap_insert(&hmap, &inst->encode_node,
                          hash_2words(inst->raw, inst->hdrs.ofp_version));
          }
          ovsthread_once_done(&once);
      }
      return &hmap;
  }
  
  static enum ofperr
  ofpact_decode_raw(enum ofp_version ofp_version,
                    const struct ofp_action_header *oah, size_t length,
                    const struct ofpact_raw_instance **instp)
  {
      const struct ofpact_raw_instance *inst;
      struct ofpact_hdrs hdrs;
  
      *instp = NULL;
      if (length < sizeof *oah) {
          return OFPERR_OFPBAC_BAD_LEN;
      }
  
      /* Get base action type. */
      if (oah->type == htons(OFPAT_VENDOR)) {
          /* Get vendor. */
          hdrs.vendor = ntohl(oah->vendor);
          if (hdrs.vendor == NX_VENDOR_ID || hdrs.vendor == ONF_VENDOR_ID) {
              /* Get extension subtype. */
              const struct ext_action_header *nah;
  
              nah = ALIGNED_CAST(const struct ext_action_header *, oah);
              if (length < sizeof *nah) {
                  return OFPERR_OFPBAC_BAD_LEN;
              }
              hdrs.type = ntohs(nah->subtype);
          } else {
              VLOG_WARN_RL(&rl, "OpenFlow action has unknown vendor %#"PRIx32,
                           hdrs.vendor);
              return OFPERR_OFPBAC_BAD_VENDOR;
          }
      } else {
          hdrs.vendor = 0;
          hdrs.type = ntohs(oah->type);
      }
  
      hdrs.ofp_version = ofp_version;
      HMAP_FOR_EACH_WITH_HASH (inst, decode_node, ofpact_hdrs_hash(&hdrs),
                               ofpact_decode_hmap()) {
          if (ofpact_hdrs_equal(&hdrs, &inst->hdrs)) {
              *instp = inst;
              return 0;
          }
      }
  
      VLOG_WARN_RL(&rl, "unknown %s action for vendor %#"PRIx32" and "
                   "type %"PRIu16, ofputil_version_to_string(ofp_version),
                   hdrs.vendor, hdrs.type);
      return (hdrs.vendor
              ? OFPERR_OFPBAC_BAD_VENDOR_TYPE
              : OFPERR_OFPBAC_BAD_TYPE);
  }
  
  static enum ofperr
  ofpact_pull_raw(struct ofpbuf *buf, enum ofp_version ofp_version,
                  enum ofp_raw_action_type *raw, uint64_t *arg)
  {
      const struct ofp_action_header *oah = buf->data;
      const struct ofpact_raw_instance *action;
      unsigned int length;
      enum ofperr error;
  
      *raw = *arg = 0;
      error = ofpact_decode_raw(ofp_version, oah, buf->size, &action);
      if (error) {
          return error;
      }
  
      if (action->deprecation) {
          VLOG_INFO_RL(&rl, "%s is deprecated in %s (%s)",
                       action->name, ofputil_version_to_string(ofp_version),
                       action->deprecation);
      }
  
      length = ntohs(oah->len);
      if (length > buf->size) {
          VLOG_WARN_RL(&rl, "OpenFlow action %s length %u exceeds action buffer "
                       "length %"PRIu32, action->name, length, buf->size);
          return OFPERR_OFPBAC_BAD_LEN;
      }
      if (length < action->min_length || length > action->max_length) {
          VLOG_WARN_RL(&rl, "OpenFlow action %s length %u not in valid range "
                       "[%hu,%hu]", action->name, length,
                       action->min_length, action->max_length);
          return OFPERR_OFPBAC_BAD_LEN;
      }
      if (length % 8) {
          VLOG_WARN_RL(&rl, "OpenFlow action %s length %u is not a multiple "
                       "of 8", action->name, length);
          return OFPERR_OFPBAC_BAD_LEN;
      }
  
      *raw = action->raw;
      *arg = 0;
      if (action->arg_len) {
          const uint8_t *p;
          int i;
  
          p = ofpbuf_at_assert(buf, action->arg_ofs, action->arg_len);
          for (i = 0; i < action->arg_len; i++) {
              *arg = (*arg << 8) | p[i];
          }
      }
  
      ofpbuf_pull(buf, length);
  
      return 0;
  }
  
  static const struct ofpact_raw_instance *
  ofpact_raw_lookup(enum ofp_version ofp_version, enum ofp_raw_action_type raw)
  {
      const struct ofpact_raw_instance *inst;
  
      HMAP_FOR_EACH_WITH_HASH (inst, encode_node, hash_2words(raw, ofp_version),
                               ofpact_encode_hmap()) {
          if (inst->raw == raw && inst->hdrs.ofp_version == ofp_version) {
              return inst;
          }
      }
      OVS_NOT_REACHED();
  }
  
  static void *
  ofpact_put_raw(struct ofpbuf *buf, enum ofp_version ofp_version,
                 enum ofp_raw_action_type raw, uint64_t arg)
  {
      const struct ofpact_raw_instance *inst;
      struct ofp_action_header *oah;
      const struct ofpact_hdrs *hdrs;
  
      inst = ofpact_raw_lookup(ofp_version, raw);
      hdrs = &inst->hdrs;
  
      oah = ofpbuf_put_zeros(buf, inst->min_length);
      oah->type = htons(hdrs->vendor ? OFPAT_VENDOR : hdrs->type);
      oah->len = htons(inst->min_length);
      oah->vendor = htonl(hdrs->vendor);
  
      switch (hdrs->vendor) {
      case 0:
          break;
  
      case NX_VENDOR_ID:
      case ONF_VENDOR_ID: {
          struct ext_action_header *nah = (struct ext_action_header *) oah;
          nah->subtype = htons(hdrs->type);
          break;
      }
  
      default:
          OVS_NOT_REACHED();
      }
  
      if (inst->arg_len) {
          uint8_t *p = (uint8_t *) oah + inst->arg_ofs + inst->arg_len;
          int i;
  
          for (i = 0; i < inst->arg_len; i++) {
              *--p = arg;
              arg >>= 8;
          }
      } else {
          ovs_assert(!arg);
      }
  
      return oah;
  }
  
  static void
  pad_ofpat(struct ofpbuf *openflow, size_t start_ofs)
  {
      struct ofp_action_header *oah;
  
      ofpbuf_put_zeros(openflow, PAD_SIZE(openflow->size - start_ofs,
                                          OFP_ACTION_ALIGN));
  
      oah = ofpbuf_at_assert(openflow, start_ofs, sizeof *oah);
      oah->len = htons(openflow->size - start_ofs);
  }
  
  