text: /*
   * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015 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 "ofp-print.h"
  #include <ctype.h>
  #include <errno.h>
  #include <inttypes.h>
  #include <sys/types.h>
  #include <netinet/in.h>
  #include <netinet/icmp6.h>
  #include <stdlib.h>
  #include "bundle.h"
  #include "byte-order.h"
  #include "classifier.h"
  #include "dynamic-string.h"
  #include "learn.h"
  #include "meta-flow.h"
  #include "multipath.h"
  #include "netdev.h"
  #include "nx-match.h"
  #include "id-pool.h"
  #include "ofp-actions.h"
  #include "ofp-errors.h"
  #include "ofp-msgs.h"
  #include "ofp-util.h"
  #include "ofpbuf.h"
  #include "openflow/netronome-ext.h"
  #include "packets.h"
  #include "random.h"
  #include "tun-metadata.h"
  #include "unaligned.h"
  #include "type-props.h"
  #include "openvswitch/vlog.h"
  #include "bitmap.h"
  
  VLOG_DEFINE_THIS_MODULE(ofp_util);
  
  /* Rate limit for OpenFlow message parse errors.  These always indicate a bug
   * in the peer and so there's not much point in showing a lot of them. */
  static struct vlog_rate_limit bad_ofmsg_rl = VLOG_RATE_LIMIT_INIT(1, 5);
  
  static enum ofputil_table_eviction ofputil_decode_table_eviction(
      ovs_be32 config, enum ofp_version);
  static ovs_be32 ofputil_encode_table_config(enum ofputil_table_miss,
                                              enum ofputil_table_eviction,
                                              enum ofp_version);
  
  struct ofp_prop_header {
      ovs_be16 type;
      ovs_be16 len;
  };
  
  struct ofp_prop_experimenter {
      ovs_be16 type;          /* OFP*_EXPERIMENTER. */
      ovs_be16 length;        /* Length in bytes of this property. */
      ovs_be32 experimenter;  /* Experimenter ID which takes the same form as
                               * in struct ofp_experimenter_header. */
      ovs_be32 exp_type;      /* Experimenter defined. */
  };
  
  /* Pulls a property, beginning with struct ofp_prop_header, from the beginning
   * of 'msg'.  Stores the type of the property in '*typep' and, if 'property' is
   * nonnull, the entire property, including the header, in '*property'.  Returns
   * 0 if successful, otherwise an error code.
   *
   * This function pulls the property's stated size padded out to a multiple of
   * 'alignment' bytes.  The common case in OpenFlow is an 'alignment' of 8, so
   * you can use ofputil_pull_property() for that case. */
  static enum ofperr
  ofputil_pull_property__(struct ofpbuf *msg, struct ofpbuf *property,
                          unsigned int alignment, uint16_t *typep)
  {
      struct ofp_prop_header *oph;
      unsigned int padded_len;
      unsigned int len;
  
      if (msg->size < sizeof *oph) {
          return OFPERR_OFPBPC_BAD_LEN;
      }
  
      oph = msg->data;
      len = ntohs(oph->len);
      padded_len = ROUND_UP(len, alignment);
      if (len < sizeof *oph || padded_len > msg->size) {
          return OFPERR_OFPBPC_BAD_LEN;
      }
  
      *typep = ntohs(oph->type);
      if (property) {
          ofpbuf_use_const(property, msg->data, len);
      }
      ofpbuf_pull(msg, padded_len);
      return 0;
  }
  
  /* Pulls a property, beginning with struct ofp_prop_header, from the beginning
   * of 'msg'.  Stores the type of the property in '*typep' and, if 'property' is
   * nonnull, the entire property, including the header, in '*property'.  Returns
   * 0 if successful, otherwise an error code.
   *
   * This function pulls the property's stated size padded out to a multiple of
   * 8 bytes, which is the common case for OpenFlow properties. */
  static enum ofperr
  ofputil_pull_property(struct ofpbuf *msg, struct ofpbuf *property,
                        uint16_t *typep)
  {
      return ofputil_pull_property__(msg, property, 8, typep);
  }
  
  static void OVS_PRINTF_FORMAT(2, 3)
  log_property(bool loose, const char *message, ...)
  {
      enum vlog_level level = loose ? VLL_DBG : VLL_WARN;
      if (!vlog_should_drop(THIS_MODULE, level, &bad_ofmsg_rl)) {
          va_list args;
  
          va_start(args, message);
          vlog_valist(THIS_MODULE, level, message, args);
          va_end(args);
      }
  }
  
  static size_t
  start_property(struct ofpbuf *msg, uint16_t type)
  {
      size_t start_ofs = msg->size;
      struct ofp_prop_header *oph;
  
      oph = ofpbuf_put_uninit(msg, sizeof *oph);
      oph->type = htons(type);
      oph->len = htons(4);        /* May be updated later by end_property(). */
      return start_ofs;
  }
  
  static void
  end_property(struct ofpbuf *msg, size_t start_ofs)
  {
      struct ofp_prop_header *oph;
  
      oph = ofpbuf_at_assert(msg, start_ofs, sizeof *oph);
      oph->len = htons(msg->size - start_ofs);
      ofpbuf_padto(msg, ROUND_UP(msg->size, 8));
  }
  
  static void
  put_bitmap_properties(struct ofpbuf *msg, uint64_t bitmap)
  {
      for (; bitmap; bitmap = zero_rightmost_1bit(bitmap)) {
          start_property(msg, rightmost_1bit_idx(bitmap));
      }
  }
  
  /* Given the wildcard bit count in the least-significant 6 of 'wcbits', returns
   * an IP netmask with a 1 in each bit that must match and a 0 in each bit that
   * is wildcarded.
   *
   * The bits in 'wcbits' are in the format used in enum ofp_flow_wildcards: 0
   * is exact match, 1 ignores the LSB, 2 ignores the 2 least-significant bits,
   * ..., 32 and higher wildcard the entire field.  This is the *opposite* of the
   * usual convention where e.g. /24 indicates that 8 bits (not 24 bits) are
   * wildcarded. */
  ovs_be32
  ofputil_wcbits_to_netmask(int wcbits)
  {
      wcbits &= 0x3f;
      return wcbits < 32 ? htonl(~((1u << wcbits) - 1)) : 0;
  }
  
  /* Given the IP netmask 'netmask', returns the number of bits of the IP address
   * that it wildcards, that is, the number of 0-bits in 'netmask', a number
   * between 0 and 32 inclusive.
   *
   * If 'netmask' is not a CIDR netmask (see ip_is_cidr()), the return value will
   * still be in the valid range but isn't otherwise meaningful. */
  int
  ofputil_netmask_to_wcbits(ovs_be32 netmask)
  {
      return 32 - ip_count_cidr_bits(netmask);
  }
  
  /* Converts the OpenFlow 1.0 wildcards in 'ofpfw' (OFPFW10_*) into a
   * flow_wildcards in 'wc' for use in struct match.  It is the caller's
   * responsibility to handle the special case where the flow match's dl_vlan is
   * set to OFP_VLAN_NONE. */
  void
  ofputil_wildcard_from_ofpfw10(uint32_t ofpfw, struct flow_wildcards *wc)
  {
      BUILD_ASSERT_DECL(FLOW_WC_SEQ == 33);
  
      /* Initialize most of wc. */
      flow_wildcards_init_catchall(wc);
  
      if (!(ofpfw & OFPFW10_IN_PORT)) {
          wc->masks.in_port.ofp_port = u16_to_ofp(UINT16_MAX);
      }
  
      if (!(ofpfw & OFPFW10_NW_TOS)) {
          wc->masks.nw_tos |= IP_DSCP_MASK;
      }
  
      if (!(ofpfw & OFPFW10_NW_PROTO)) {
          wc->masks.nw_proto = UINT8_MAX;
      }
      wc->masks.nw_src = ofputil_wcbits_to_netmask(ofpfw
                                                   >> OFPFW10_NW_SRC_SHIFT);
      wc->masks.nw_dst = ofputil_wcbits_to_netmask(ofpfw
                                                   >> OFPFW10_NW_DST_SHIFT);
  
      if (!(ofpfw & OFPFW10_TP_SRC)) {
          wc->masks.tp_src = OVS_BE16_MAX;
      }
      if (!(ofpfw & OFPFW10_TP_DST)) {
          wc->masks.tp_dst = OVS_BE16_MAX;
      }
  
      if (!(ofpfw & OFPFW10_DL_SRC)) {
          memset(wc->masks.dl_src, 0xff, ETH_ADDR_LEN);
      }
      if (!(ofpfw & OFPFW10_DL_DST)) {
          memset(wc->masks.dl_dst, 0xff, ETH_ADDR_LEN);
      }
      if (!(ofpfw & OFPFW10_DL_TYPE)) {
          wc->masks.dl_type = OVS_BE16_MAX;
      }
  
      /* VLAN TCI mask. */
      if (!(ofpfw & OFPFW10_DL_VLAN_PCP)) {
          wc->masks.vlan_tci |= htons(VLAN_PCP_MASK | VLAN_CFI);
      }
      if (!(ofpfw & OFPFW10_DL_VLAN)) {
          wc->masks.vlan_tci |= htons(VLAN_VID_MASK | VLAN_CFI);
      }
  }
  
  /* Converts the ofp10_match in 'ofmatch' into a struct match in 'match'. */
  void
  ofputil_match_from_ofp10_match(const struct ofp10_match *ofmatch,
                                 struct match *match)
  {
      uint32_t ofpfw = ntohl(ofmatch->wildcards) & OFPFW10_ALL;
  
      /* Initialize match->wc. */
      memset(&match->flow, 0, sizeof match->flow);
      ofputil_wildcard_from_ofpfw10(ofpfw, &match->wc);
  
      /* Initialize most of match->flow. */
      match->flow.nw_src = ofmatch->nw_src;
      match->flow.nw_dst = ofmatch->nw_dst;
      match->flow.in_port.ofp_port = u16_to_ofp(ntohs(ofmatch->in_port));
      match->flow.dl_type = ofputil_dl_type_from_openflow(ofmatch->dl_type);
      match->flow.tp_src = ofmatch->tp_src;
      match->flow.tp_dst = ofmatch->tp_dst;
      memcpy(match->flow.dl_src, ofmatch->dl_src, ETH_ADDR_LEN);
      memcpy(match->flow.dl_dst, ofmatch->dl_dst, ETH_ADDR_LEN);
      match->flow.nw_tos = ofmatch->nw_tos & IP_DSCP_MASK;
      match->flow.nw_proto = ofmatch->nw_proto;
  
      /* Translate VLANs. */
      if (!(ofpfw & OFPFW10_DL_VLAN) &&
          ofmatch->dl_vlan == htons(OFP10_VLAN_NONE)) {
          /* Match only packets without 802.1Q header.
           *
           * When OFPFW10_DL_VLAN_PCP is wildcarded, this is obviously correct.
           *
           * If OFPFW10_DL_VLAN_PCP is matched, the flow match is contradictory,
           * because we can't have a specific PCP without an 802.1Q header.
           * However, older versions of OVS treated this as matching packets
           * withut an 802.1Q header, so we do here too. */
          match->flow.vlan_tci = htons(0);
          match->wc.masks.vlan_tci = htons(0xffff);
      } else {
          ovs_be16 vid, pcp, tci;
          uint16_t hpcp;
  
          vid = ofmatch->dl_vlan & htons(VLAN_VID_MASK);
          hpcp = (ofmatch->dl_vlan_pcp << VLAN_PCP_SHIFT) & VLAN_PCP_MASK;
          pcp = htons(hpcp);
          tci = vid | pcp | htons(VLAN_CFI);
          match->flow.vlan_tci = tci & match->wc.masks.vlan_tci;
      }
  
      /* Clean up. */
      match_zero_wildcarded_fields(match);
  }
  
  /* Convert 'match' into the OpenFlow 1.0 match structure 'ofmatch'. */
  void
  ofputil_match_to_ofp10_match(const struct match *match,
                               struct ofp10_match *ofmatch)
  {
      const struct flow_wildcards *wc = &match->wc;
      uint32_t ofpfw;
  
      /* Figure out most OpenFlow wildcards. */
      ofpfw = 0;
      if (!wc->masks.in_port.ofp_port) {
          ofpfw |= OFPFW10_IN_PORT;
      }
      if (!wc->masks.dl_type) {
          ofpfw |= OFPFW10_DL_TYPE;
      }
      if (!wc->masks.nw_proto) {
          ofpfw |= OFPFW10_NW_PROTO;
      }
      ofpfw |= (ofputil_netmask_to_wcbits(wc->masks.nw_src)
                << OFPFW10_NW_SRC_SHIFT);
      ofpfw |= (ofputil_netmask_to_wcbits(wc->masks.nw_dst)
                << OFPFW10_NW_DST_SHIFT);
      if (!(wc->masks.nw_tos & IP_DSCP_MASK)) {
          ofpfw |= OFPFW10_NW_TOS;
      }
      if (!wc->masks.tp_src) {
          ofpfw |= OFPFW10_TP_SRC;
      }
      if (!wc->masks.tp_dst) {
          ofpfw |= OFPFW10_TP_DST;
      }
      if (eth_addr_is_zero(wc->masks.dl_src)) {
          ofpfw |= OFPFW10_DL_SRC;
      }
      if (eth_addr_is_zero(wc->masks.dl_dst)) {
          ofpfw |= OFPFW10_DL_DST;
      }
  
      /* Translate VLANs. */
      ofmatch->dl_vlan = htons(0);
      ofmatch->dl_vlan_pcp = 0;
      if (match->wc.masks.vlan_tci == htons(0)) {
          ofpfw |= OFPFW10_DL_VLAN | OFPFW10_DL_VLAN_PCP;
      } else if (match->wc.masks.vlan_tci & htons(VLAN_CFI)
                 && !(match->flow.vlan_tci & htons(VLAN_CFI))) {
          ofmatch->dl_vlan = htons(OFP10_VLAN_NONE);
          ofpfw |= OFPFW10_DL_VLAN_PCP;
      } else {
          if (!(match->wc.masks.vlan_tci & htons(VLAN_VID_MASK))) {
              ofpfw |= OFPFW10_DL_VLAN;
          } else {
              ofmatch->dl_vlan = htons(vlan_tci_to_vid(match->flow.vlan_tci));
          }
  
          if (!(match->wc.masks.vlan_tci & htons(VLAN_PCP_MASK))) {
              ofpfw |= OFPFW10_DL_VLAN_PCP;
          } else {
              ofmatch->dl_vlan_pcp = vlan_tci_to_pcp(match->flow.vlan_tci);
          }
      }
  
      /* Compose most of the match structure. */
      ofmatch->wildcards = htonl(ofpfw);
      ofmatch->in_port = htons(ofp_to_u16(match->flow.in_port.ofp_port));
      memcpy(ofmatch->dl_src, match->flow.dl_src, ETH_ADDR_LEN);
      memcpy(ofmatch->dl_dst, match->flow.dl_dst, ETH_ADDR_LEN);
      ofmatch->dl_type = ofputil_dl_type_to_openflow(match->flow.dl_type);
      ofmatch->nw_src = match->flow.nw_src;
      ofmatch->nw_dst = match->flow.nw_dst;
      ofmatch->nw_tos = match->flow.nw_tos & IP_DSCP_MASK;
      ofmatch->nw_proto = match->flow.nw_proto;
      ofmatch->tp_src = match->flow.tp_src;
      ofmatch->tp_dst = match->flow.tp_dst;
      memset(ofmatch->pad1, '\0', sizeof ofmatch->pad1);
      memset(ofmatch->pad2, '\0', sizeof ofmatch->pad2);
  }
  
  enum ofperr
  ofputil_pull_ofp11_match(struct ofpbuf *buf, struct match *match,
                           uint16_t *padded_match_len)
  {
      struct ofp11_match_header *omh = buf->data;
      uint16_t match_len;
  
      if (buf->size < sizeof *omh) {
          return OFPERR_OFPBMC_BAD_LEN;
      }
  
      match_len = ntohs(omh->length);
  
      switch (ntohs(omh->type)) {
      case OFPMT_STANDARD: {
          struct ofp11_match *om;
  
          if (match_len != sizeof *om || buf->size < sizeof *om) {
              return OFPERR_OFPBMC_BAD_LEN;
          }
          om = ofpbuf_pull(buf, sizeof *om);
          if (padded_match_len) {
              *padded_match_len = match_len;
          }
          return ofputil_match_from_ofp11_match(om, match);
      }
  
      case OFPMT_OXM:
          if (padded_match_len) {
              *padded_match_len = ROUND_UP(match_len, 8);
          }
          return oxm_pull_match(buf, match);
  
      default:
          return OFPERR_OFPBMC_BAD_TYPE;
      }
  }
  
  /* Converts the ofp11_match in 'ofmatch' into a struct match in 'match'.
   * Returns 0 if successful, otherwise an OFPERR_* value. */
  enum ofperr
  ofputil_match_from_ofp11_match(const struct ofp11_match *ofmatch,
                                 struct match *match)
  {
      uint16_t wc = ntohl(ofmatch->wildcards);
      uint8_t dl_src_mask[ETH_ADDR_LEN];
      uint8_t dl_dst_mask[ETH_ADDR_LEN];
      bool ipv4, arp, rarp;
      int i;
  
      match_init_catchall(match);
  
      if (!(wc & OFPFW11_IN_PORT)) {
          ofp_port_t ofp_port;
          enum ofperr error;
  
          error = ofputil_port_from_ofp11(ofmatch->in_port, &ofp_port);
          if (error) {
              return OFPERR_OFPBMC_BAD_VALUE;
          }
          match_set_in_port(match, ofp_port);
      }
  
      for (i = 0; i < ETH_ADDR_LEN; i++) {
          dl_src_mask[i] = ~ofmatch->dl_src_mask[i];
      }
      match_set_dl_src_masked(match, ofmatch->dl_src, dl_src_mask);
  
      for (i = 0; i < ETH_ADDR_LEN; i++) {
          dl_dst_mask[i] = ~ofmatch->dl_dst_mask[i];
      }
      match_set_dl_dst_masked(match, ofmatch->dl_dst, dl_dst_mask);
  
      if (!(wc & OFPFW11_DL_VLAN)) {
          if (ofmatch->dl_vlan == htons(OFPVID11_NONE)) {
              /* Match only packets without a VLAN tag. */
              match->flow.vlan_tci = htons(0);
              match->wc.masks.vlan_tci = OVS_BE16_MAX;
          } else {
              if (ofmatch->dl_vlan == htons(OFPVID11_ANY)) {
                  /* Match any packet with a VLAN tag regardless of VID. */
                  match->flow.vlan_tci = htons(VLAN_CFI);
                  match->wc.masks.vlan_tci = htons(VLAN_CFI);
              } else if (ntohs(ofmatch->dl_vlan) < 4096) {
                  /* Match only packets with the specified VLAN VID. */
                  match->flow.vlan_tci = htons(VLAN_CFI) | ofmatch->dl_vlan;
                  match->wc.masks.vlan_tci = htons(VLAN_CFI | VLAN_VID_MASK);
              } else {
                  /* Invalid VID. */
                  return OFPERR_OFPBMC_BAD_VALUE;
              }
  
              if (!(wc & OFPFW11_DL_VLAN_PCP)) {
                  if (ofmatch->dl_vlan_pcp <= 7) {
                      match->flow.vlan_tci |= htons(ofmatch->dl_vlan_pcp
                                                    << VLAN_PCP_SHIFT);
                      match->wc.masks.vlan_tci |= htons(VLAN_PCP_MASK);
                  } else {
                      /* Invalid PCP. */
                      return OFPERR_OFPBMC_BAD_VALUE;
                  }
              }
          }
      }
  
      if (!(wc & OFPFW11_DL_TYPE)) {
          match_set_dl_type(match,
                            ofputil_dl_type_from_openflow(ofmatch->dl_type));
      }
  
      ipv4 = match->flow.dl_type == htons(ETH_TYPE_IP);
      arp = match->flow.dl_type == htons(ETH_TYPE_ARP);
      rarp = match->flow.dl_type == htons(ETH_TYPE_RARP);
  
      if (ipv4 && !(wc & OFPFW11_NW_TOS)) {
          if (ofmatch->nw_tos & ~IP_DSCP_MASK) {
              /* Invalid TOS. */
              return OFPERR_OFPBMC_BAD_VALUE;
          }
  
          match_set_nw_dscp(match, ofmatch->nw_tos);
      }
  
      if (ipv4 || arp || rarp) {
          if (!(wc & OFPFW11_NW_PROTO)) {
              match_set_nw_proto(match, ofmatch->nw_proto);
          }
          match_set_nw_src_masked(match, ofmatch->nw_src, ~ofmatch->nw_src_mask);
          match_set_nw_dst_masked(match, ofmatch->nw_dst, ~ofmatch->nw_dst_mask);
      }
  
  #define OFPFW11_TP_ALL (OFPFW11_TP_SRC | OFPFW11_TP_DST)
      if (ipv4 && (wc & OFPFW11_TP_ALL) != OFPFW11_TP_ALL) {
          switch (match->flow.nw_proto) {
          case IPPROTO_ICMP:
              /* "A.2.3 Flow Match Structures" in OF1.1 says:
               *
               *    The tp_src and tp_dst fields will be ignored unless the
               *    network protocol specified is as TCP, UDP or SCTP.
               *
               * but I'm pretty sure we should support ICMP too, otherwise
               * that's a regression from OF1.0. */
              if (!(wc & OFPFW11_TP_SRC)) {
                  uint16_t icmp_type = ntohs(ofmatch->tp_src);
                  if (icmp_type < 0x100) {
                      match_set_icmp_type(match, icmp_type);
                  } else {
                      return OFPERR_OFPBMC_BAD_FIELD;
                  }
              }
              if (!(wc & OFPFW11_TP_DST)) {
                  uint16_t icmp_code = ntohs(ofmatch->tp_dst);
                  if (icmp_code < 0x100) {
                      match_set_icmp_code(match, icmp_code);
                  } else {
                      return OFPERR_OFPBMC_BAD_FIELD;
                  }
              }
              break;
  
          case IPPROTO_TCP:
          case IPPROTO_UDP:
          case IPPROTO_SCTP:
              if (!(wc & (OFPFW11_TP_SRC))) {
                  match_set_tp_src(match, ofmatch->tp_src);
              }
              if (!(wc & (OFPFW11_TP_DST))) {
                  match_set_tp_dst(match, ofmatch->tp_dst);
              }
              break;
  
          default:
              /* OF1.1 says explicitly to ignore this. */
              break;
          }
      }
  
      if (eth_type_mpls(match->flow.dl_type)) {
          if (!(wc & OFPFW11_MPLS_LABEL)) {
              match_set_mpls_label(match, 0, ofmatch->mpls_label);
          }
          if (!(wc & OFPFW11_MPLS_TC)) {
              match_set_mpls_tc(match, 0, ofmatch->mpls_tc);
          }
      }
  
      match_set_metadata_masked(match, ofmatch->metadata,
                                ~ofmatch->metadata_mask);
  
      return 0;
  }
  
  /* Convert 'match' into the OpenFlow 1.1 match structure 'ofmatch'. */
  void
  ofputil_match_to_ofp11_match(const struct match *match,
                               struct ofp11_match *ofmatch)
  {
      uint32_t wc = 0;
      int i;
  
      memset(ofmatch, 0, sizeof *ofmatch);
      ofmatch->omh.type = htons(OFPMT_STANDARD);
      ofmatch->omh.length = htons(OFPMT11_STANDARD_LENGTH);
  
      if (!match->wc.masks.in_port.ofp_port) {
          wc |= OFPFW11_IN_PORT;
      } else {
          ofmatch->in_port = ofputil_port_to_ofp11(match->flow.in_port.ofp_port);
      }
  
      memcpy(ofmatch->dl_src, match->flow.dl_src, ETH_ADDR_LEN);
      for (i = 0; i < ETH_ADDR_LEN; i++) {
          ofmatch->dl_src_mask[i] = ~match->wc.masks.dl_src[i];
      }
  
      memcpy(ofmatch->dl_dst, match->flow.dl_dst, ETH_ADDR_LEN);
      for (i = 0; i < ETH_ADDR_LEN; i++) {
          ofmatch->dl_dst_mask[i] = ~match->wc.masks.dl_dst[i];
      }
  
      if (match->wc.masks.vlan_tci == htons(0)) {
          wc |= OFPFW11_DL_VLAN | OFPFW11_DL_VLAN_PCP;
      } else if (match->wc.masks.vlan_tci & htons(VLAN_CFI)
                 && !(match->flow.vlan_tci & htons(VLAN_CFI))) {
          ofmatch->dl_vlan = htons(OFPVID11_NONE);
          wc |= OFPFW11_DL_VLAN_PCP;
      } else {
          if (!(match->wc.masks.vlan_tci & htons(VLAN_VID_MASK))) {
              ofmatch->dl_vlan = htons(OFPVID11_ANY);
          } else {
              ofmatch->dl_vlan = htons(vlan_tci_to_vid(match->flow.vlan_tci));
          }
  
          if (!(match->wc.masks.vlan_tci & htons(VLAN_PCP_MASK))) {
              wc |= OFPFW11_DL_VLAN_PCP;
          } else {
              ofmatch->dl_vlan_pcp = vlan_tci_to_pcp(match->flow.vlan_tci);
          }
      }
  
      if (!match->wc.masks.dl_type) {
          wc |= OFPFW11_DL_TYPE;
      } else {
          ofmatch->dl_type = ofputil_dl_type_to_openflow(match->flow.dl_type);
      }
  
      if (!(match->wc.masks.nw_tos & IP_DSCP_MASK)) {
          wc |= OFPFW11_NW_TOS;
      } else {
          ofmatch->nw_tos = match->flow.nw_tos & IP_DSCP_MASK;
      }
  
      if (!match->wc.masks.nw_proto) {
          wc |= OFPFW11_NW_PROTO;
      } else {
          ofmatch->nw_proto = match->flow.nw_proto;
      }
  
      ofmatch->nw_src = match->flow.nw_src;
      ofmatch->nw_src_mask = ~match->wc.masks.nw_src;
      ofmatch->nw_dst = match->flow.nw_dst;
      ofmatch->nw_dst_mask = ~match->wc.masks.nw_dst;
  
      if (!match->wc.masks.tp_src) {
          wc |= OFPFW11_TP_SRC;
      } else {
          ofmatch->tp_src = match->flow.tp_src;
      }
  
      if (!match->wc.masks.tp_dst) {
          wc |= OFPFW11_TP_DST;
      } else {
          ofmatch->tp_dst = match->flow.tp_dst;
      }
  
      if (!(match->wc.masks.mpls_lse[0] & htonl(MPLS_LABEL_MASK))) {
          wc |= OFPFW11_MPLS_LABEL;
      } else {
          ofmatch->mpls_label = htonl(mpls_lse_to_label(
                                          match->flow.mpls_lse[0]));
      }
  
      if (!(match->wc.masks.mpls_lse[0] & htonl(MPLS_TC_MASK))) {
          wc |= OFPFW11_MPLS_TC;
      } else {
          ofmatch->mpls_tc = mpls_lse_to_tc(match->flow.mpls_lse[0]);
      }
  
      ofmatch->metadata = match->flow.metadata;
      ofmatch->metadata_mask = ~match->wc.masks.metadata;
  
      ofmatch->wildcards = htonl(wc);
  }
  
  /* Returns the "typical" length of a match for 'protocol', for use in
   * estimating space to preallocate. */
  int
  ofputil_match_typical_len(enum ofputil_protocol protocol)
  {
      switch (protocol) {
      case OFPUTIL_P_OF10_STD:
      case OFPUTIL_P_OF10_STD_TID:
          return sizeof(struct ofp10_match);
  
      case OFPUTIL_P_OF10_NXM:
      case OFPUTIL_P_OF10_NXM_TID:
          return NXM_TYPICAL_LEN;
  
      case OFPUTIL_P_OF11_STD:
          return sizeof(struct ofp11_match);
  
      case OFPUTIL_P_OF12_OXM:
      case OFPUTIL_P_OF13_OXM:
      case OFPUTIL_P_OF14_OXM:
      case OFPUTIL_P_OF15_OXM:
          return NXM_TYPICAL_LEN;
  
      default:
          OVS_NOT_REACHED();
      }
  }
  
  /* Appends to 'b' an struct ofp11_match_header followed by a match that
   * expresses 'match' properly for 'protocol', plus enough zero bytes to pad the
   * data appended out to a multiple of 8.  'protocol' must be one that is usable
   * in OpenFlow 1.1 or later.
   *
   * This function can cause 'b''s data to be reallocated.
   *
   * Returns the number of bytes appended to 'b', excluding the padding.  Never
   * returns zero. */
  int
  ofputil_put_ofp11_match(struct ofpbuf *b, const struct match *match,
                          enum ofputil_protocol protocol)
  {
      switch (protocol) {
      case OFPUTIL_P_OF10_STD:
      case OFPUTIL_P_OF10_STD_TID:
      case OFPUTIL_P_OF10_NXM:
      case OFPUTIL_P_OF10_NXM_TID:
          OVS_NOT_REACHED();
  
      case OFPUTIL_P_OF11_STD: {
          struct ofp11_match *om;
  
          /* Make sure that no padding is needed. */
          BUILD_ASSERT_DECL(sizeof *om % 8 == 0);
  
          om = ofpbuf_put_uninit(b, sizeof *om);
          ofputil_match_to_ofp11_match(match, om);
          return sizeof *om;
      }
  
      case OFPUTIL_P_OF12_OXM:
      case OFPUTIL_P_OF13_OXM:
      case OFPUTIL_P_OF14_OXM:
      case OFPUTIL_P_OF15_OXM:
          return oxm_put_match(b, match,
                               ofputil_protocol_to_ofp_version(protocol));
      }
  
      OVS_NOT_REACHED();
  }
  
  /* Given a 'dl_type' value in the format used in struct flow, returns the
   * corresponding 'dl_type' value for use in an ofp10_match or ofp11_match
   * structure. */
  ovs_be16
  ofputil_dl_type_to_openflow(ovs_be16 flow_dl_type)
  {
      return (flow_dl_type == htons(FLOW_DL_TYPE_NONE)
              ? htons(OFP_DL_TYPE_NOT_ETH_TYPE)
              : flow_dl_type);
  }
  
  /* Given a 'dl_type' value in the format used in an ofp10_match or ofp11_match
   * structure, returns the corresponding 'dl_type' value for use in struct
   * flow. */
  ovs_be16
  ofputil_dl_type_from_openflow(ovs_be16 ofp_dl_type)
  {
      return (ofp_dl_type == htons(OFP_DL_TYPE_NOT_ETH_TYPE)
              ? htons(FLOW_DL_TYPE_NONE)
              : ofp_dl_type);
  }
  
  /* Protocols. */
  
  struct proto_abbrev {
      enum ofputil_protocol protocol;
      const char *name;
  };
  
  /* Most users really don't care about some of the differences between
   * protocols.  These abbreviations help with that. */
  static const struct proto_abbrev proto_abbrevs[] = {
      { OFPUTIL_P_ANY,          "any" },
      { OFPUTIL_P_OF10_STD_ANY, "OpenFlow10" },
      { OFPUTIL_P_OF10_NXM_ANY, "NXM" },
      { OFPUTIL_P_ANY_OXM,      "OXM" },
  };
  #define N_PROTO_ABBREVS ARRAY_SIZE(proto_abbrevs)
  
  enum ofputil_protocol ofputil_flow_dump_protocols[] = {
      OFPUTIL_P_OF15_OXM,
      OFPUTIL_P_OF14_OXM,
      OFPUTIL_P_OF13_OXM,
      OFPUTIL_P_OF12_OXM,
      OFPUTIL_P_OF11_STD,
      OFPUTIL_P_OF10_NXM,
      OFPUTIL_P_OF10_STD,
  };
  size_t ofputil_n_flow_dump_protocols = ARRAY_SIZE(ofputil_flow_dump_protocols);
  
  /* Returns the set of ofputil_protocols that are supported with the given
   * OpenFlow 'version'.  'version' should normally be an 8-bit OpenFlow version
   * identifier (e.g. 0x01 for OpenFlow 1.0, 0x02 for OpenFlow 1.1).  Returns 0
   * if 'version' is not supported or outside the valid range.  */
  enum ofputil_protocol
  ofputil_protocols_from_ofp_version(enum ofp_version version)
  {
      switch (version) {
      case OFP10_VERSION:
          return OFPUTIL_P_OF10_STD_ANY | OFPUTIL_P_OF10_NXM_ANY;
      case OFP11_VERSION:
          return OFPUTIL_P_OF11_STD;
      case OFP12_VERSION:
          return OFPUTIL_P_OF12_OXM;
      case OFP13_VERSION:
          return OFPUTIL_P_OF13_OXM;
      case OFP14_VERSION:
          return OFPUTIL_P_OF14_OXM;
      case OFP15_VERSION:
          return OFPUTIL_P_OF15_OXM;
      default:
          return 0;
      }
  }
  
  /* Returns the ofputil_protocol that is initially in effect on an OpenFlow
   * connection that has negotiated the given 'version'.  'version' should
   * normally be an 8-bit OpenFlow version identifier (e.g. 0x01 for OpenFlow
   * 1.0, 0x02 for OpenFlow 1.1).  Returns 0 if 'version' is not supported or
   * outside the valid range.  */
  enum ofputil_protocol
  ofputil_protocol_from_ofp_version(enum ofp_version version)
  {
      return rightmost_1bit(ofputil_protocols_from_ofp_version(version));
  }
  
  /* Returns the OpenFlow protocol version number (e.g. OFP10_VERSION,
   * etc.) that corresponds to 'protocol'. */
  enum ofp_version
  ofputil_protocol_to_ofp_version(enum ofputil_protocol protocol)
  {
      switch (protocol) {
      case OFPUTIL_P_OF10_STD:
      case OFPUTIL_P_OF10_STD_TID:
      case OFPUTIL_P_OF10_NXM:
      case OFPUTIL_P_OF10_NXM_TID:
          return OFP10_VERSION;
      case OFPUTIL_P_OF11_STD:
          return OFP11_VERSION;
      case OFPUTIL_P_OF12_OXM:
          return OFP12_VERSION;
      case OFPUTIL_P_OF13_OXM:
          return OFP13_VERSION;
      case OFPUTIL_P_OF14_OXM:
          return OFP14_VERSION;
      case OFPUTIL_P_OF15_OXM:
          return OFP15_VERSION;
      }
  
      OVS_NOT_REACHED();
  }
  
  /* Returns a bitmap of OpenFlow versions that are supported by at
   * least one of the 'protocols'. */
  uint32_t
  ofputil_protocols_to_version_bitmap(enum ofputil_protocol protocols)
  {
      uint32_t bitmap = 0;
  
      for (; protocols; protocols = zero_rightmost_1bit(protocols)) {
          enum ofputil_protocol protocol = rightmost_1bit(protocols);
  
          bitmap |= 1u << ofputil_protocol_to_ofp_version(protocol);
      }
  
      return bitmap;
  }
  
  /* Returns the set of protocols that are supported on top of the
   * OpenFlow versions included in 'bitmap'. */
  enum ofputil_protocol
  ofputil_protocols_from_version_bitmap(uint32_t bitmap)
  {
      enum ofputil_protocol protocols = 0;
  
      for (; bitmap; bitmap = zero_rightmost_1bit(bitmap)) {
          enum ofp_version version = rightmost_1bit_idx(bitmap);
  
          protocols |= ofputil_protocols_from_ofp_version(version);
      }
  
      return protocols;
  }
  
  /* Returns true if 'protocol' is a single OFPUTIL_P_* value, false
   * otherwise. */
  bool
  ofputil_protocol_is_valid(enum ofputil_protocol protocol)
  {
      return protocol & OFPUTIL_P_ANY && is_pow2(protocol);
  }
  
  /* Returns the equivalent of 'protocol' with the Nicira flow_mod_table_id
   * extension turned on or off if 'enable' is true or false, respectively.
   *
   * This extension is only useful for protocols whose "standard" version does
   * not allow specific tables to be modified.  In particular, this is true of
   * OpenFlow 1.0.  In later versions of OpenFlow, a flow_mod request always
   * specifies a table ID and so there is no need for such an extension.  When
   * 'protocol' is such a protocol that doesn't need a flow_mod_table_id
   * extension, this function just returns its 'protocol' argument unchanged
   * regardless of the value of 'enable'.  */
  enum ofputil_protocol
  ofputil_protocol_set_tid(enum ofputil_protocol protocol, bool enable)
  {
      switch (protocol) {
      case OFPUTIL_P_OF10_STD:
      case OFPUTIL_P_OF10_STD_TID:
          return enable ? OFPUTIL_P_OF10_STD_TID : OFPUTIL_P_OF10_STD;
  
      case OFPUTIL_P_OF10_NXM:
      case OFPUTIL_P_OF10_NXM_TID:
          return enable ? OFPUTIL_P_OF10_NXM_TID : OFPUTIL_P_OF10_NXM;
  
      case OFPUTIL_P_OF11_STD:
          return OFPUTIL_P_OF11_STD;
  
      case OFPUTIL_P_OF12_OXM:
          return OFPUTIL_P_OF12_OXM;
  
      case OFPUTIL_P_OF13_OXM:
          return OFPUTIL_P_OF13_OXM;
  
      case OFPUTIL_P_OF14_OXM:
          return OFPUTIL_P_OF14_OXM;
  
      case OFPUTIL_P_OF15_OXM:
          return OFPUTIL_P_OF15_OXM;
  
      default:
          OVS_NOT_REACHED();
      }
  }
  
  /* Returns the "base" version of 'protocol'.  That is, if 'protocol' includes
   * some extension to a standard protocol version, the return value is the
   * standard version of that protocol without any extension.  If 'protocol' is a
   * standard protocol version, returns 'protocol' unchanged. */
  enum ofputil_protocol
  ofputil_protocol_to_base(enum ofputil_protocol protocol)
  {
      return ofputil_protocol_set_tid(protocol, false);
  }
  
  /* Returns 'new_base' with any extensions taken from 'cur'. */
  enum ofputil_protocol
  ofputil_protocol_set_base(enum ofputil_protocol cur,
                            enum ofputil_protocol new_base)
  {
      bool tid = (cur & OFPUTIL_P_TID) != 0;
  
      switch (new_base) {
      case OFPUTIL_P_OF10_STD:
      case OFPUTIL_P_OF10_STD_TID:
          return ofputil_protocol_set_tid(OFPUTIL_P_OF10_STD, tid);
  
      case OFPUTIL_P_OF10_NXM:
      case OFPUTIL_P_OF10_NXM_TID:
          return ofputil_protocol_set_tid(OFPUTIL_P_OF10_NXM, tid);
  
      case OFPUTIL_P_OF11_STD:
          return ofputil_protocol_set_tid(OFPUTIL_P_OF11_STD, tid);
  
      case OFPUTIL_P_OF12_OXM:
          return ofputil_protocol_set_tid(OFPUTIL_P_OF12_OXM, tid);
  
      case OFPUTIL_P_OF13_OXM:
          return ofputil_protocol_set_tid(OFPUTIL_P_OF13_OXM, tid);
  
      case OFPUTIL_P_OF14_OXM:
          return ofputil_protocol_set_tid(OFPUTIL_P_OF14_OXM, tid);
  
      case OFPUTIL_P_OF15_OXM:
          return ofputil_protocol_set_tid(OFPUTIL_P_OF15_OXM, tid);
  
      default:
          OVS_NOT_REACHED();
      }
  }
  
  /* Returns a string form of 'protocol', if a simple form exists (that is, if
   * 'protocol' is either a single protocol or it is a combination of protocols
   * that have a single abbreviation).  Otherwise, returns NULL. */
  const char *
  ofputil_protocol_to_string(enum ofputil_protocol protocol)
  {
      const struct proto_abbrev *p;
  
      /* Use a "switch" statement for single-bit names so that we get a compiler
       * warning if we forget any. */
      switch (protocol) {
      case OFPUTIL_P_OF10_NXM:
          return "NXM-table_id";
  
      case OFPUTIL_P_OF10_NXM_TID:
          return "NXM+table_id";
  
      case OFPUTIL_P_OF10_STD:
          return "OpenFlow10-table_id";
  
      case OFPUTIL_P_OF10_STD_TID:
          return "OpenFlow10+table_id";
  
      case OFPUTIL_P_OF11_STD:
          return "OpenFlow11";
  
      case OFPUTIL_P_OF12_OXM:
          return "OXM-OpenFlow12";
  
      case OFPUTIL_P_OF13_OXM:
          return "OXM-OpenFlow13";
  
      case OFPUTIL_P_OF14_OXM:
          return "OXM-OpenFlow14";
  
      case OFPUTIL_P_OF15_OXM:
          return "OXM-OpenFlow15";
      }
  
      /* Check abbreviations. */
      for (p = proto_abbrevs; p < &proto_abbrevs[N_PROTO_ABBREVS]; p++) {
          if (protocol == p->protocol) {
              return p->name;
          }
      }
  
      return NULL;
  }
  
  /* Returns a string that represents 'protocols'.  The return value might be a
   * comma-separated list if 'protocols' doesn't have a simple name.  The return
   * value is "none" if 'protocols' is 0.
   *
   * The caller must free the returned string (with free()). */
  char *
  ofputil_protocols_to_string(enum ofputil_protocol protocols)
  {
      struct ds s;
  
      ovs_assert(!(protocols & ~OFPUTIL_P_ANY));
      if (protocols == 0) {
          return xstrdup("none");
      }
  
      ds_init(&s);
      while (protocols) {
          const struct proto_abbrev *p;
          int i;
  
          if (s.length) {
              ds_put_char(&s, ',');
          }
  
          for (p = proto_abbrevs; p < &proto_abbrevs[N_PROTO_ABBREVS]; p++) {
              if ((protocols & p->protocol) == p->protocol) {
                  ds_put_cstr(&s, p->name);
                  protocols &= ~p->protocol;
                  goto match;
              }
          }
  
          for (i = 0; i < CHAR_BIT * sizeof(enum ofputil_protocol); i++) {
              enum ofputil_protocol bit = 1u << i;
  
              if (protocols & bit) {
                  ds_put_cstr(&s, ofputil_protocol_to_string(bit));
                  protocols &= ~bit;
                  goto match;
              }
          }
          OVS_NOT_REACHED();
  
      match: ;
      }
      return ds_steal_cstr(&s);
  }
  
  static enum ofputil_protocol
  ofputil_protocol_from_string__(const char *s, size_t n)
  {
      const struct proto_abbrev *p;
      int i;
  
      for (i = 0; i < CHAR_BIT * sizeof(enum ofputil_protocol); i++) {
          enum ofputil_protocol bit = 1u << i;
          const char *name = ofputil_protocol_to_string(bit);
  
          if (name && n == strlen(name) && !strncasecmp(s, name, n)) {
              return bit;
          }
      }
  
      for (p = proto_abbrevs; p < &proto_abbrevs[N_PROTO_ABBREVS]; p++) {
          if (n == strlen(p->name) && !strncasecmp(s, p->name, n)) {
              return p->protocol;
          }
      }
  
      return 0;
  }
  
  /* Returns the nonempty set of protocols represented by 's', which can be a
   * single protocol name or abbreviation or a comma-separated list of them.
   *
   * Aborts the program with an error message if 's' is invalid. */
  enum ofputil_protocol
  ofputil_protocols_from_string(const char *s)
  {
      const char *orig_s = s;
      enum ofputil_protocol protocols;
  
      protocols = 0;
      while (*s) {
          enum ofputil_protocol p;
          size_t n;
  
          n = strcspn(s, ",");
          if (n == 0) {
              s++;
              continue;
          }
  
          p = ofputil_protocol_from_string__(s, n);
          if (!p) {
              ovs_fatal(0, "%.*s: unknown flow protocol", (int) n, s);
          }
          protocols |= p;
  
          s += n;
      }
  
      if (!protocols) {
          ovs_fatal(0, "%s: no flow protocol specified", orig_s);
      }
      return protocols;
  }
  
  enum ofp_version
  ofputil_version_from_string(const char *s)
  {
      if (!strcasecmp(s, "OpenFlow10")) {
          return OFP10_VERSION;
      }
      if (!strcasecmp(s, "OpenFlow11")) {
          return OFP11_VERSION;
      }
      if (!strcasecmp(s, "OpenFlow12")) {
          return OFP12_VERSION;
      }
      if (!strcasecmp(s, "OpenFlow13")) {
          return OFP13_VERSION;
      }
      if (!strcasecmp(s, "OpenFlow14")) {
          return OFP14_VERSION;
      }
      if (!strcasecmp(s, "OpenFlow15")) {
          return OFP15_VERSION;
      }
      return 0;
  }
  
  static bool
  is_delimiter(unsigned char c)
  {
      return isspace(c) || c == ',';
  }
  
  uint32_t
  ofputil_versions_from_string(const char *s)
  {
      size_t i = 0;
      uint32_t bitmap = 0;
  
      while (s[i]) {
          size_t j;
          int version;
          char *key;
  
          if (is_delimiter(s[i])) {
              i++;
              continue;
          }
          j = 0;
          while (s[i + j] && !is_delimiter(s[i + j])) {
              j++;
          }
          key = xmemdup0(s + i, j);
          version = ofputil_version_from_string(key);
          if (!version) {
              VLOG_FATAL("Unknown OpenFlow version: \"%s\"", key);
          }
          free(key);
          bitmap |= 1u << version;
          i += j;
      }
  
      return bitmap;
  }
  
  uint32_t
  ofputil_versions_from_strings(char ** const s, size_t count)
  {
      uint32_t bitmap = 0;
  
      while (count--) {
          int version = ofputil_version_from_string(s[count]);
          if (!version) {
              VLOG_WARN("Unknown OpenFlow version: \"%s\"", s[count]);
          } else {
              bitmap |= 1u << version;
          }
      }
  
      return bitmap;
  }
  
  const char *
  ofputil_version_to_string(enum ofp_version ofp_version)
  {
      switch (ofp_version) {
      case OFP10_VERSION:
          return "OpenFlow10";
      case OFP11_VERSION:
          return "OpenFlow11";
      case OFP12_VERSION:
          return "OpenFlow12";
      case OFP13_VERSION:
          return "OpenFlow13";
      case OFP14_VERSION:
          return "OpenFlow14";
      case OFP15_VERSION:
          return "OpenFlow15";
      default:
          OVS_NOT_REACHED();
      }
  }
  
  bool
  ofputil_packet_in_format_is_valid(enum nx_packet_in_format packet_in_format)
  {
      switch (packet_in_format) {
      case NXPIF_OPENFLOW10:
      case NXPIF_NXM:
          return true;
      }
  
      return false;
  }
  
  const char *
  ofputil_packet_in_format_to_string(enum nx_packet_in_format packet_in_format)
  {
      switch (packet_in_format) {
      case NXPIF_OPENFLOW10:
          return "openflow10";
      case NXPIF_NXM:
          return "nxm";
      default:
          OVS_NOT_REACHED();
      }
  }
  
  int
  ofputil_packet_in_format_from_string(const char *s)
  {
      return (!strcmp(s, "openflow10") ? NXPIF_OPENFLOW10
              : !strcmp(s, "nxm") ? NXPIF_NXM
              : -1);
  }
  
  void
  ofputil_format_version(struct ds *msg, enum ofp_version version)
  {
      ds_put_format(msg, "0x%02x", version);
  }
  
  void
  ofputil_format_version_name(struct ds *msg, enum ofp_version version)
  {
      ds_put_cstr(msg, ofputil_version_to_string(version));
  }
  
  static void
  ofputil_format_version_bitmap__(struct ds *msg, uint32_t bitmap,
                                  void (*format_version)(struct ds *msg,
                                                         enum ofp_version))
  {
      while (bitmap) {
          format_version(msg, raw_ctz(bitmap));
          bitmap = zero_rightmost_1bit(bitmap);
          if (bitmap) {
              ds_put_cstr(msg, ", ");
          }
      }
  }
  
  void
  ofputil_format_version_bitmap(struct ds *msg, uint32_t bitmap)
  {
      ofputil_format_version_bitmap__(msg, bitmap, ofputil_format_version);
  }
  
  void
  ofputil_format_version_bitmap_names(struct ds *msg, uint32_t bitmap)
  {
      ofputil_format_version_bitmap__(msg, bitmap, ofputil_format_version_name);
  }
  
  static bool
  ofputil_decode_hello_bitmap(const struct ofp_hello_elem_header *oheh,
                              uint32_t *allowed_versionsp)
  {
      uint16_t bitmap_len = ntohs(oheh->length) - sizeof *oheh;
      const ovs_be32 *bitmap = ALIGNED_CAST(const ovs_be32 *, oheh + 1);
      uint32_t allowed_versions;
  
      if (!bitmap_len || bitmap_len % sizeof *bitmap) {
          return false;
      }
  
      /* Only use the first 32-bit element of the bitmap as that is all the
       * current implementation supports.  Subsequent elements are ignored which
       * should have no effect on session negotiation until Open vSwitch supports
       * wire-protocol versions greater than 31.
       */
      allowed_versions = ntohl(bitmap[0]);
  
      if (allowed_versions & 1) {
          /* There's no OpenFlow version 0. */
          VLOG_WARN_RL(&bad_ofmsg_rl, "peer claims to support invalid OpenFlow "
                       "version 0x00");
          allowed_versions &= ~1u;
      }
  
      if (!allowed_versions) {
          VLOG_WARN_RL(&bad_ofmsg_rl, "peer does not support any OpenFlow "
                       "version (between 0x01 and 0x1f)");
          return false;
      }
  
      *allowed_versionsp = allowed_versions;
      return true;
  }
  
  static uint32_t
  version_bitmap_from_version(uint8_t ofp_version)
  {
      return ((ofp_version < 32 ? 1u << ofp_version : 0) - 1) << 1;
  }
  
  /* Decodes OpenFlow OFPT_HELLO message 'oh', storing into '*allowed_versions'
   * the set of OpenFlow versions for which 'oh' announces support.
   *
   * Because of how OpenFlow defines OFPT_HELLO messages, this function is always
   * successful, and thus '*allowed_versions' is always initialized.  However, it
   * returns false if 'oh' contains some data that could not be fully understood,
   * true if 'oh' was completely parsed. */
  bool
  ofputil_decode_hello(const struct ofp_header *oh, uint32_t *allowed_versions)
  {
      struct ofpbuf msg;
      bool ok = true;
  
      ofpbuf_use_const(&msg, oh, ntohs(oh->length));
      ofpbuf_pull(&msg, sizeof *oh);
  
      *allowed_versions = version_bitmap_from_version(oh->version);
      while (msg.size) {
          const struct ofp_hello_elem_header *oheh;
          unsigned int len;
  
          if (msg.size < sizeof *oheh) {
              return false;
          }
  
          oheh = msg.data;
          len = ntohs(oheh->length);
          if (len < sizeof *oheh || !ofpbuf_try_pull(&msg, ROUND_UP(len, 8))) {
              return false;
          }
  
          if (oheh->type != htons(OFPHET_VERSIONBITMAP)
              || !ofputil_decode_hello_bitmap(oheh, allowed_versions)) {
              ok = false;
          }
      }
  
      return ok;
  }
  
  /* Returns true if 'allowed_versions' needs to be accompanied by a version
   * bitmap to be correctly expressed in an OFPT_HELLO message. */
  static bool
  should_send_version_bitmap(uint32_t allowed_versions)
  {
      return !is_pow2((allowed_versions >> 1) + 1);
  }
  
  /* Create an OFPT_HELLO message that expresses support for the OpenFlow
   * versions in the 'allowed_versions' bitmaps and returns the message. */
  struct ofpbuf *
  ofputil_encode_hello(uint32_t allowed_versions)
  {
      enum ofp_version ofp_version;
      struct ofpbuf *msg;
  
      ofp_version = leftmost_1bit_idx(allowed_versions);
      msg = ofpraw_alloc(OFPRAW_OFPT_HELLO, ofp_version, 0);
  
      if (should_send_version_bitmap(allowed_versions)) {
          struct ofp_hello_elem_header *oheh;
          uint16_t map_len;
  
          map_len = sizeof allowed_versions;
          oheh = ofpbuf_put_zeros(msg, ROUND_UP(map_len + sizeof *oheh, 8));
          oheh->type = htons(OFPHET_VERSIONBITMAP);
          oheh->length = htons(map_len + sizeof *oheh);
          *ALIGNED_CAST(ovs_be32 *, oheh + 1) = htonl(allowed_versions);
  
          ofpmsg_update_length(msg);
      }
  
      return msg;
  }
  
  /* Returns an OpenFlow message that, sent on an OpenFlow connection whose
   * protocol is 'current', at least partly transitions the protocol to 'want'.
   * Stores in '*next' the protocol that will be in effect on the OpenFlow
   * connection if the switch processes the returned message correctly.  (If
   * '*next != want' then the caller will have to iterate.)
   *
   * If 'current == want', or if it is not possible to transition from 'current'
   * to 'want' (because, for example, 'current' and 'want' use different OpenFlow
   * protocol versions), returns NULL and stores 'current' in '*next'. */
  struct ofpbuf *
  ofputil_encode_set_protocol(enum ofputil_protocol current,
                              enum ofputil_protocol want,
                              enum ofputil_protocol *next)
  {
      enum ofp_version cur_version, want_version;
      enum ofputil_protocol cur_base, want_base;
      bool cur_tid, want_tid;
  
      cur_version = ofputil_protocol_to_ofp_version(current);
      want_version = ofputil_protocol_to_ofp_version(want);
      if (cur_version != want_version) {
          *next = current;
          return NULL;
      }
  
      cur_base = ofputil_protocol_to_base(current);
      want_base = ofputil_protocol_to_base(want);
      if (cur_base != want_base) {
          *next = ofputil_protocol_set_base(current, want_base);
  
          switch (want_base) {
          case OFPUTIL_P_OF10_NXM:
              return ofputil_encode_nx_set_flow_format(NXFF_NXM);
  
          case OFPUTIL_P_OF10_STD:
              return ofputil_encode_nx_set_flow_format(NXFF_OPENFLOW10);
  
          case OFPUTIL_P_OF11_STD:
          case OFPUTIL_P_OF12_OXM:
          case OFPUTIL_P_OF13_OXM:
          case OFPUTIL_P_OF14_OXM:
          case OFPUTIL_P_OF15_OXM:
              /* There is only one variant of each OpenFlow 1.1+ protocol, and we
               * verified above that we're not trying to change versions. */
              OVS_NOT_REACHED();
  
          case OFPUTIL_P_OF10_STD_TID:
          case OFPUTIL_P_OF10_NXM_TID:
              OVS_NOT_REACHED();
          }
      }
  
      cur_tid = (current & OFPUTIL_P_TID) != 0;
      want_tid = (want & OFPUTIL_P_TID) != 0;
      if (cur_tid != want_tid) {
          *next = ofputil_protocol_set_tid(current, want_tid);
          return ofputil_make_flow_mod_table_id(want_tid);
      }
  
      ovs_assert(current == want);
  
      *next = current;
      return NULL;
  }
  
  /* Returns an NXT_SET_FLOW_FORMAT message that can be used to set the flow
   * format to 'nxff'.  */
  struct ofpbuf *
  ofputil_encode_nx_set_flow_format(enum nx_flow_format nxff)
  {
      struct nx_set_flow_format *sff;
      struct ofpbuf *msg;
  
      ovs_assert(ofputil_nx_flow_format_is_valid(nxff));
  
      msg = ofpraw_alloc(OFPRAW_NXT_SET_FLOW_FORMAT, OFP10_VERSION, 0);
      sff = ofpbuf_put_zeros(msg, sizeof *sff);
      sff->format = htonl(nxff);
  
      return msg;
  }
  
  /* Returns the base protocol if 'flow_format' is a valid NXFF_* value, false
   * otherwise. */
  enum ofputil_protocol
  ofputil_nx_flow_format_to_protocol(enum nx_flow_format flow_format)
  {
      switch (flow_format) {
      case NXFF_OPENFLOW10:
          return OFPUTIL_P_OF10_STD;
  
      case NXFF_NXM:
          return OFPUTIL_P_OF10_NXM;
  
      default:
          return 0;
      }
  }
  
  /* Returns true if 'flow_format' is a valid NXFF_* value, false otherwise. */
  bool
  ofputil_nx_flow_format_is_valid(enum nx_flow_format flow_format)
  {
      return ofputil_nx_flow_format_to_protocol(flow_format) != 0;
  }
  
  /* Returns a string version of 'flow_format', which must be a valid NXFF_*
   * value. */
  const char *
  ofputil_nx_flow_format_to_string(enum nx_flow_format flow_format)
  {
      switch (flow_format) {
      case NXFF_OPENFLOW10:
          return "openflow10";
      case NXFF_NXM:
          return "nxm";
      default:
          OVS_NOT_REACHED();
      }
  }
  
  struct ofpbuf *
  ofputil_make_set_packet_in_format(enum ofp_version ofp_version,
                                    enum nx_packet_in_format packet_in_format)
  {
      struct nx_set_packet_in_format *spif;
      struct ofpbuf *msg;
  
      msg = ofpraw_alloc(OFPRAW_NXT_SET_PACKET_IN_FORMAT, ofp_version, 0);
      spif = ofpbuf_put_zeros(msg, sizeof *spif);
      spif->format = htonl(packet_in_format);
  
      return msg;
  }
  
  /* Returns an OpenFlow message that can be used to turn the flow_mod_table_id
   * extension on or off (according to 'flow_mod_table_id'). */
  struct ofpbuf *
  ofputil_make_flow_mod_table_id(bool flow_mod_table_id)
  {
      struct nx_flow_mod_table_id *nfmti;
      struct ofpbuf *msg;
  
      msg = ofpraw_alloc(OFPRAW_NXT_FLOW_MOD_TABLE_ID, OFP10_VERSION, 0);
      nfmti = ofpbuf_put_zeros(msg, sizeof *nfmti);
      nfmti->set = flow_mod_table_id;
      return msg;
  }
  
  struct ofputil_flow_mod_flag {
      uint16_t raw_flag;
      enum ofp_version min_version, max_version;
      enum ofputil_flow_mod_flags flag;
  };
  
  static const struct ofputil_flow_mod_flag ofputil_flow_mod_flags[] = {
      { OFPFF_SEND_FLOW_REM,   OFP10_VERSION, 0, OFPUTIL_FF_SEND_FLOW_REM },
      { OFPFF_CHECK_OVERLAP,   OFP10_VERSION, 0, OFPUTIL_FF_CHECK_OVERLAP },
      { OFPFF10_EMERG,         OFP10_VERSION, OFP10_VERSION,
        OFPUTIL_FF_EMERG },
      { OFPFF12_RESET_COUNTS,  OFP12_VERSION, 0, OFPUTIL_FF_RESET_COUNTS },
      { OFPFF13_NO_PKT_COUNTS, OFP13_VERSION, 0, OFPUTIL_FF_NO_PKT_COUNTS },
      { OFPFF13_NO_BYT_COUNTS, OFP13_VERSION, 0, OFPUTIL_FF_NO_BYT_COUNTS },
      { 0, 0, 0, 0 },
  };
  
  static enum ofperr
  ofputil_decode_flow_mod_flags(ovs_be16 raw_flags_,
                                enum ofp_flow_mod_command command,
                                enum ofp_version version,
                                enum ofputil_flow_mod_flags *flagsp)
  {
      uint16_t raw_flags = ntohs(raw_flags_);
      const struct ofputil_flow_mod_flag *f;
  
      *flagsp = 0;
      for (f = ofputil_flow_mod_flags; f->raw_flag; f++) {
          if (raw_flags & f->raw_flag
              && version >= f->min_version
              && (!f->max_version || version <= f->max_version)) {
              raw_flags &= ~f->raw_flag;
              *flagsp |= f->flag;
          }
      }
  
      /* In OF1.0 and OF1.1, "add" always resets counters, and other commands
       * never do.
       *
       * In OF1.2 and later, OFPFF12_RESET_COUNTS controls whether each command
       * resets counters. */
      if ((version == OFP10_VERSION || version == OFP11_VERSION)
          && command == OFPFC_ADD) {
          *flagsp |= OFPUTIL_FF_RESET_COUNTS;
      }
  
      return raw_flags ? OFPERR_OFPFMFC_BAD_FLAGS : 0;
  }
  
  static ovs_be16
  ofputil_encode_flow_mod_flags(enum ofputil_flow_mod_flags flags,
                                enum ofp_version version)
  {
      const struct ofputil_flow_mod_flag *f;
      uint16_t raw_flags;
  
      raw_flags = 0;
      for (f = ofputil_flow_mod_flags; f->raw_flag; f++) {
          if (f->flag & flags
              && version >= f->min_version
              && (!f->max_version || version <= f->max_version)) {
              raw_flags |= f->raw_flag;
          }
      }
  
      return htons(raw_flags);
  }
  
  /* Converts an OFPT_FLOW_MOD or NXT_FLOW_MOD message 'oh' into an abstract
   * flow_mod in 'fm'.  Returns 0 if successful, otherwise an OpenFlow error
   * code.
   *
   * Uses 'ofpacts' to store the abstract OFPACT_* version of 'oh''s actions.
   * The caller must initialize 'ofpacts' and retains ownership of it.
   * 'fm->ofpacts' will point into the 'ofpacts' buffer.
   *
   * Does not validate the flow_mod actions.  The caller should do that, with
   * ofpacts_check(). */
  enum ofperr
  ofputil_decode_flow_mod(struct ofputil_flow_mod *fm,
                          const struct ofp_header *oh,
                          enum ofputil_protocol protocol,
                          struct ofpbuf *ofpacts,
                          ofp_port_t max_port, uint8_t max_table)
  {
      ovs_be16 raw_flags;
      enum ofperr error;
      struct ofpbuf b;
      enum ofpraw raw;
  
      /* Ignored for non-delete actions */
      fm->delete_reason = OFPRR_DELETE;
  
      ofpbuf_use_const(&b, oh, ntohs(oh->length));
      raw = ofpraw_pull_assert(&b);
      if (raw == OFPRAW_OFPT11_FLOW_MOD) {
          /* Standard OpenFlow 1.1+ flow_mod. */
          const struct ofp11_flow_mod *ofm;
  
          ofm = ofpbuf_pull(&b, sizeof *ofm);
  
          error = ofputil_pull_ofp11_match(&b, &fm->match, NULL);
          if (error) {
              return error;
          }
  
          /* Translate the message. */
          fm->priority = ntohs(ofm->priority);
          if (ofm->command == OFPFC_ADD
              || (oh->version == OFP11_VERSION
                  && (ofm->command == OFPFC_MODIFY ||
                      ofm->command == OFPFC_MODIFY_STRICT)
                  && ofm->cookie_mask == htonll(0))) {
              /* In OpenFlow 1.1 only, a "modify" or "modify-strict" that does
               * not match on the cookie is treated as an "add" if there is no
               * match. */
              fm->cookie = htonll(0);
              fm->cookie_mask = htonll(0);
              fm->new_cookie = ofm->cookie;
          } else {
              fm->cookie = ofm->cookie;
              fm->cookie_mask = ofm->cookie_mask;
              fm->new_cookie = OVS_BE64_MAX;
          }
          fm->modify_cookie = false;
          fm->command = ofm->command;
  
          /* Get table ID.
           *
           * OF1.1 entirely forbids table_id == OFPTT_ALL.
           * OF1.2+ allows table_id == OFPTT_ALL only for deletes. */
          fm->table_id = ofm->table_id;
          if (fm->table_id == OFPTT_ALL
              && (oh->version == OFP11_VERSION
                  || (ofm->command != OFPFC_DELETE &&
                      ofm->command != OFPFC_DELETE_STRICT))) {
              return OFPERR_OFPFMFC_BAD_TABLE_ID;
          }
  
          fm->idle_timeout = ntohs(ofm->idle_timeout);
          fm->hard_timeout = ntohs(ofm->hard_timeout);
          if (oh->version >= OFP14_VERSION && ofm->command == OFPFC_ADD) {
              fm->importance = ntohs(ofm->importance);
          } else {
              fm->importance = 0;
          }
          fm->buffer_id = ntohl(ofm->buffer_id);
          error = ofputil_port_from_ofp11(ofm->out_port, &fm->out_port);
          if (error) {
              return error;
          }
  
          fm->out_group = (ofm->command == OFPFC_DELETE ||
                           ofm->command == OFPFC_DELETE_STRICT
                           ? ntohl(ofm->out_group)
                           : OFPG11_ANY);
          raw_flags = ofm->flags;
      } else {
          uint16_t command;
  
          if (raw == OFPRAW_OFPT10_FLOW_MOD) {
              /* Standard OpenFlow 1.0 flow_mod. */
              const struct ofp10_flow_mod *ofm;
  
              /* Get the ofp10_flow_mod. */
              ofm = ofpbuf_pull(&b, sizeof *ofm);
  
              /* Translate the rule. */
              ofputil_match_from_ofp10_match(&ofm->match, &fm->match);
              ofputil_normalize_match(&fm->match);
  
              /* OpenFlow 1.0 says that exact-match rules have to have the
               * highest possible priority. */
              fm->priority = (ofm->match.wildcards & htonl(OFPFW10_ALL)
                              ? ntohs(ofm->priority)
                              : UINT16_MAX);
  
              /* Translate the message. */
              command = ntohs(ofm->command);
              fm->cookie = htonll(0);
              fm->cookie_mask = htonll(0);
              fm->new_cookie = ofm->cookie;
              fm->idle_timeout = ntohs(ofm->idle_timeout);
              fm->hard_timeout = ntohs(ofm->hard_timeout);
              fm->importance = 0;
              fm->buffer_id = ntohl(ofm->buffer_id);
              fm->out_port = u16_to_ofp(ntohs(ofm->out_port));
              fm->out_group = OFPG11_ANY;
              raw_flags = ofm->flags;
          } else if (raw == OFPRAW_NXT_FLOW_MOD) {
              /* Nicira extended flow_mod. */
              const struct nx_flow_mod *nfm;
  
              /* Dissect the message. */
              nfm = ofpbuf_pull(&b, sizeof *nfm);
              error = nx_pull_match(&b, ntohs(nfm->match_len),
                                    &fm->match, &fm->cookie, &fm->cookie_mask);
              if (error) {
                  return error;
              }
  
              /* Translate the message. */
              command = ntohs(nfm->command);
              if ((command & 0xff) == OFPFC_ADD && fm->cookie_mask) {
                  /* Flow additions may only set a new cookie, not match an
                   * existing cookie. */
                  return OFPERR_NXBRC_NXM_INVALID;
              }
              fm->priority = ntohs(nfm->priority);
              fm->new_cookie = nfm->cookie;
              fm->idle_timeout = ntohs(nfm->idle_timeout);
              fm->hard_timeout = ntohs(nfm->hard_timeout);
              fm->importance = 0;
              fm->buffer_id = ntohl(nfm->buffer_id);
              fm->out_port = u16_to_ofp(ntohs(nfm->out_port));
              fm->out_group = OFPG11_ANY;
              raw_flags = nfm->flags;
          } else {
              OVS_NOT_REACHED();
          }
  
          fm->modify_cookie = fm->new_cookie != OVS_BE64_MAX;
          if (protocol & OFPUTIL_P_TID) {
              fm->command = command & 0xff;
              fm->table_id = command >> 8;
          } else {
              if (command > 0xff) {
                  VLOG_WARN_RL(&bad_ofmsg_rl, "flow_mod has explicit table_id "
                               "but flow_mod_table_id extension is not enabled");
              }
              fm->command = command;
              fm->table_id = 0xff;
          }
      }
  
      if (fm->command > OFPFC_DELETE_STRICT) {
          return OFPERR_OFPFMFC_BAD_COMMAND;
      }
  
      error = ofpacts_pull_openflow_instructions(&b, b.size,
                                                 oh->version, ofpacts);
      if (error) {
          return error;
      }
      fm->ofpacts = ofpacts->data;
      fm->ofpacts_len = ofpacts->size;
  
      error = ofputil_decode_flow_mod_flags(raw_flags, fm->command,
                                            oh->version, &fm->flags);
      if (error) {
          return error;
      }
  
      if (fm->flags & OFPUTIL_FF_EMERG) {
          /* We do not support the OpenFlow 1.0 emergency flow cache, which
           * is not required in OpenFlow 1.0.1 and removed from OpenFlow 1.1.
           *
           * OpenFlow 1.0 specifies the error code to use when idle_timeout
           * or hard_timeout is nonzero.  Otherwise, there is no good error
           * code, so just state that the flow table is full. */
          return (fm->hard_timeout || fm->idle_timeout
                  ? OFPERR_OFPFMFC_BAD_EMERG_TIMEOUT
                  : OFPERR_OFPFMFC_TABLE_FULL);
      }
  
      return ofpacts_check_consistency(fm->ofpacts, fm->ofpacts_len,
                                       &fm->match.flow, max_port,
                                       fm->table_id, max_table, protocol);
  }
  
  static enum ofperr
  ofputil_pull_bands(struct ofpbuf *msg, size_t len, uint16_t *n_bands,
                     struct ofpbuf *bands)
  {
      const struct ofp13_meter_band_header *ombh;
      struct ofputil_meter_band *mb;
      uint16_t n = 0;
  
      ombh = ofpbuf_try_pull(msg, len);
      if (!ombh) {
          return OFPERR_OFPBRC_BAD_LEN;
      }
  
      while (len >= sizeof (struct ofp13_meter_band_drop)) {
          size_t ombh_len = ntohs(ombh->len);
          /* All supported band types have the same length. */
          if (ombh_len != sizeof (struct ofp13_meter_band_drop)) {
              return OFPERR_OFPBRC_BAD_LEN;
          }
          mb = ofpbuf_put_uninit(bands, sizeof *mb);
          mb->type = ntohs(ombh->type);
          if (mb->type != OFPMBT13_DROP && mb->type != OFPMBT13_DSCP_REMARK) {
              return OFPERR_OFPMMFC_BAD_BAND;
          }
          mb->rate = ntohl(ombh->rate);
          mb->burst_size = ntohl(ombh->burst_size);
          mb->prec_level = (mb->type == OFPMBT13_DSCP_REMARK) ?
              ((struct ofp13_meter_band_dscp_remark *)ombh)->prec_level : 0;
          n++;
          len -= ombh_len;
          ombh = ALIGNED_CAST(struct ofp13_meter_band_header *,
                              (char *) ombh + ombh_len);
      }
      if (len) {
          return OFPERR_OFPBRC_BAD_LEN;
      }
      *n_bands = n;
      return 0;
  }
  
  enum ofperr
  ofputil_decode_meter_mod(const struct ofp_header *oh,
                           struct ofputil_meter_mod *mm,
                           struct ofpbuf *bands)
  {
      const struct ofp13_meter_mod *omm;
      struct ofpbuf b;
  
      ofpbuf_use_const(&b, oh, ntohs(oh->length));
      ofpraw_pull_assert(&b);
      omm = ofpbuf_pull(&b, sizeof *omm);
  
      /* Translate the message. */
      mm->command = ntohs(omm->command);
      if (mm->command != OFPMC13_ADD &&
          mm->command != OFPMC13_MODIFY &&
          mm->command != OFPMC13_DELETE) {
          return OFPERR_OFPMMFC_BAD_COMMAND;
      }
      mm->meter.meter_id = ntohl(omm->meter_id);
  
      if (mm->command == OFPMC13_DELETE) {
          mm->meter.flags = 0;
          mm->meter.n_bands = 0;
          mm->meter.bands = NULL;
      } else {
          enum ofperr error;
  
          mm->meter.flags = ntohs(omm->flags);
          if (mm->meter.flags & OFPMF13_KBPS &&
              mm->meter.flags & OFPMF13_PKTPS) {
              return OFPERR_OFPMMFC_BAD_FLAGS;
          }
          mm->meter.bands = bands->data;
  
          error = ofputil_pull_bands(&b, b.size, &mm->meter.n_bands, bands);
          if (error) {
              return error;
          }
      }
      return 0;
  }
  
  void
  ofputil_decode_meter_request(const struct ofp_header *oh, uint32_t *meter_id)
  {
      const struct ofp13_meter_multipart_request *omr = ofpmsg_body(oh);
      *meter_id = ntohl(omr->meter_id);
  }
  
  struct ofpbuf *
  ofputil_encode_meter_request(enum ofp_version ofp_version,
                               enum ofputil_meter_request_type type,
                               uint32_t meter_id)
  {
      struct ofpbuf *msg;
  
      enum ofpraw raw;
  
      switch (type) {
      case OFPUTIL_METER_CONFIG:
          raw = OFPRAW_OFPST13_METER_CONFIG_REQUEST;
          break;
      case OFPUTIL_METER_STATS:
          raw = OFPRAW_OFPST13_METER_REQUEST;
          break;
      default:
      case OFPUTIL_METER_FEATURES:
          raw = OFPRAW_OFPST13_METER_FEATURES_REQUEST;
          break;
      }
  
      msg = ofpraw_alloc(raw, ofp_version, 0);
  
      if (type != OFPUTIL_METER_FEATURES) {
          struct ofp13_meter_multipart_request *omr;
          omr = ofpbuf_put_zeros(msg, sizeof *omr);
          omr->meter_id = htonl(meter_id);
      }
      return msg;
  }
  
  static void
  ofputil_put_bands(uint16_t n_bands, const struct ofputil_meter_band *mb,
                    struct ofpbuf *msg)
  {
      uint16_t n = 0;
  
      for (n = 0; n < n_bands; ++n) {
          /* Currently all band types have same size. */
          struct ofp13_meter_band_dscp_remark *ombh;
          size_t ombh_len = sizeof *ombh;
  
          ombh = ofpbuf_put_zeros(msg, ombh_len);
  
          ombh->type = htons(mb->type);
          ombh->len = htons(ombh_len);
          ombh->rate = htonl(mb->rate);
          ombh->burst_size = htonl(mb->burst_size);
          ombh->prec_level = mb->prec_level;
  
          mb++;
      }
  }
  
  /* Encode a meter stat for 'mc' and append it to 'replies'. */
  void
  ofputil_append_meter_config(struct ovs_list *replies,
                              const struct ofputil_meter_config *mc)
  {
      struct ofpbuf *msg = ofpbuf_from_list(list_back(replies));
      size_t start_ofs = msg->size;
      struct ofp13_meter_config *reply = ofpbuf_put_uninit(msg, sizeof *reply);
      reply->flags = htons(mc->flags);
      reply->meter_id = htonl(mc->meter_id);
  
      ofputil_put_bands(mc->n_bands, mc->bands, msg);
  
      reply->length = htons(msg->size - start_ofs);
  
      ofpmp_postappend(replies, start_ofs);
  }
  
  /* Encode a meter stat for 'ms' and append it to 'replies'. */
  void
  ofputil_append_meter_stats(struct ovs_list *replies,
                             const struct ofputil_meter_stats *ms)
  {
      struct ofp13_meter_stats *reply;
      uint16_t n = 0;
      uint16_t len;
  
      len = sizeof *reply + ms->n_bands * sizeof(struct ofp13_meter_band_stats);
      reply = ofpmp_append(replies, len);
  
      reply->meter_id = htonl(ms->meter_id);
      reply->len = htons(len);
      memset(reply->pad, 0, sizeof reply->pad);
      reply->flow_count = htonl(ms->flow_count);
      reply->packet_in_count = htonll(ms->packet_in_count);
      reply->byte_in_count = htonll(ms->byte_in_count);
      reply->duration_sec = htonl(ms->duration_sec);
      reply->duration_nsec = htonl(ms->duration_nsec);
  
      for (n = 0; n < ms->n_bands; ++n) {
          const struct ofputil_meter_band_stats *src = &ms->bands[n];
          struct ofp13_meter_band_stats *dst = &reply->band_stats[n];
  
          dst->packet_band_count = htonll(src->packet_count);
          dst->byte_band_count = htonll(src->byte_count);
      }
  }
  
  /* Converts an OFPMP_METER_CONFIG reply in 'msg' into an abstract
   * ofputil_meter_config in 'mc', with mc->bands pointing to bands decoded into
   * 'bands'.  The caller must have initialized 'bands' and retains ownership of
   * it across the call.
   *
   * Multiple OFPST13_METER_CONFIG replies can be packed into a single OpenFlow
   * message.  Calling this function multiple times for a single 'msg' iterates
   * through the replies.  'bands' is cleared for each reply.
   *
   * Returns 0 if successful, EOF if no replies were left in this 'msg',
   * otherwise a positive errno value. */
  int
  ofputil_decode_meter_config(struct ofpbuf *msg,
                              struct ofputil_meter_config *mc,
                              struct ofpbuf *bands)
  {
      const struct ofp13_meter_config *omc;
      enum ofperr err;
  
      /* Pull OpenFlow headers for the first call. */
      if (!msg->header) {
          ofpraw_pull_assert(msg);
      }
  
      if (!msg->size) {
          return EOF;
      }
  
      omc = ofpbuf_try_pull(msg, sizeof *omc);
      if (!omc) {
          VLOG_WARN_RL(&bad_ofmsg_rl,
                       "OFPMP_METER_CONFIG reply has %"PRIu32" leftover bytes at end",
                       msg->size);
          return OFPERR_OFPBRC_BAD_LEN;
      }
  
      ofpbuf_clear(bands);
      err = ofputil_pull_bands(msg, ntohs(omc->length) - sizeof *omc,
                               &mc->n_bands, bands);
      if (err) {
          return err;
      }
      mc->meter_id = ntohl(omc->meter_id);
      mc->flags = ntohs(omc->flags);
      mc->bands = bands->data;
  
      return 0;
  }
  
  static enum ofperr
  ofputil_pull_band_stats(struct ofpbuf *msg, size_t len, uint16_t *n_bands,
                          struct ofpbuf *bands)
  {
      const struct ofp13_meter_band_stats *ombs;
      struct ofputil_meter_band_stats *mbs;
      uint16_t n, i;
  
      ombs = ofpbuf_try_pull(msg, len);
      if (!ombs) {
          return OFPERR_OFPBRC_BAD_LEN;
      }
  
      n = len / sizeof *ombs;
      if (len != n * sizeof *ombs) {
          return OFPERR_OFPBRC_BAD_LEN;
      }
  
      mbs = ofpbuf_put_uninit(bands, len);
  
      for (i = 0; i < n; ++i) {
          mbs[i].packet_count = ntohll(ombs[i].packet_band_count);
          mbs[i].byte_count = ntohll(ombs[i].byte_band_count);
      }
      *n_bands = n;
      return 0;
  }
  
  /* Converts an OFPMP_METER reply in 'msg' into an abstract
   * ofputil_meter_stats in 'ms', with ms->bands pointing to band stats
   * decoded into 'bands'.
   *
   * Multiple OFPMP_METER replies can be packed into a single OpenFlow
   * message.  Calling this function multiple times for a single 'msg' iterates
   * through the replies.  'bands' is cleared for each reply.
   *
   * Returns 0 if successful, EOF if no replies were left in this 'msg',
   * otherwise a positive errno value. */
  int
  ofputil_decode_meter_stats(struct ofpbuf *msg,
                             struct ofputil_meter_stats *ms,
                             struct ofpbuf *bands)
  {
      const struct ofp13_meter_stats *oms;
      enum ofperr err;
  
      /* Pull OpenFlow headers for the first call. */
      if (!msg->header) {
          ofpraw_pull_assert(msg);
      }
  
      if (!msg->size) {
          return EOF;
      }
  
      oms = ofpbuf_try_pull(msg, sizeof *oms);
      if (!oms) {
          VLOG_WARN_RL(&bad_ofmsg_rl,
                       "OFPMP_METER reply has %"PRIu32" leftover bytes at end",
                       msg->size);
          return OFPERR_OFPBRC_BAD_LEN;
      }
  
      ofpbuf_clear(bands);
      err = ofputil_pull_band_stats(msg, ntohs(oms->len) - sizeof *oms,
                                    &ms->n_bands, bands);
      if (err) {
          return err;
      }
      ms->meter_id = ntohl(oms->meter_id);
      ms->flow_count = ntohl(oms->flow_count);
      ms->packet_in_count = ntohll(oms->packet_in_count);
      ms->byte_in_count = ntohll(oms->byte_in_count);
      ms->duration_sec = ntohl(oms->duration_sec);
      ms->duration_nsec = ntohl(oms->duration_nsec);
      ms->bands = bands->data;
  
      return 0;
  }
  
  void
  ofputil_decode_meter_features(const struct ofp_header *oh,
                                struct ofputil_meter_features *mf)
  {
      const struct ofp13_meter_features *omf = ofpmsg_body(oh);
  
      mf->max_meters = ntohl(omf->max_meter);
      mf->band_types = ntohl(omf->band_types);
      mf->capabilities = ntohl(omf->capabilities);
      mf->max_bands = omf->max_bands;
      mf->max_color = omf->max_color;
  }
  
  struct ofpbuf *
  ofputil_encode_meter_features_reply(const struct ofputil_meter_features *mf,
                                      const struct ofp_header *request)
  {
      struct ofpbuf *reply;
      struct ofp13_meter_features *omf;
  
      reply = ofpraw_alloc_stats_reply(request, 0);
      omf = ofpbuf_put_zeros(reply, sizeof *omf);
  
      omf->max_meter = htonl(mf->max_meters);
      omf->band_types = htonl(mf->band_types);
      omf->capabilities = htonl(mf->capabilities);
      omf->max_bands = mf->max_bands;
      omf->max_color = mf->max_color;
  
      return reply;
  }
  
  struct ofpbuf *
  ofputil_encode_meter_mod(enum ofp_version ofp_version,
                           const struct ofputil_meter_mod *mm)
  {
      struct ofpbuf *msg;
  
      struct ofp13_meter_mod *omm;
  
      msg = ofpraw_alloc(OFPRAW_OFPT13_METER_MOD, ofp_version,
                         NXM_TYPICAL_LEN + mm->meter.n_bands * 16);
      omm = ofpbuf_put_zeros(msg, sizeof *omm);
      omm->command = htons(mm->command);
      if (mm->command != OFPMC13_DELETE) {
          omm->flags = htons(mm->meter.flags);
      }
      omm->meter_id = htonl(mm->meter.meter_id);
  
      ofputil_put_bands(mm->meter.n_bands, mm->meter.bands, msg);
  
      ofpmsg_update_length(msg);
      return msg;
  }
  
  static ovs_be16
  ofputil_tid_command(const struct ofputil_flow_mod *fm,
                      enum ofputil_protocol protocol)
  {
      return htons(protocol & OFPUTIL_P_TID
                   ? (fm->command & 0xff) | (fm->table_id << 8)
                   : fm->command);
  }
  
  /* Converts 'fm' into an OFPT_FLOW_MOD or NXT_FLOW_MOD message according to
   * 'protocol' and returns the message. */
  struct ofpbuf *
  ofputil_encode_flow_mod(const struct ofputil_flow_mod *fm,
                          enum ofputil_protocol protocol)
  {
      enum ofp_version version = ofputil_protocol_to_ofp_version(protocol);
      ovs_be16 raw_flags = ofputil_encode_flow_mod_flags(fm->flags, version);
      struct ofpbuf *msg;
  
      switch (protocol) {
      case OFPUTIL_P_OF11_STD:
      case OFPUTIL_P_OF12_OXM:
      case OFPUTIL_P_OF13_OXM:
      case OFPUTIL_P_OF14_OXM:
      case OFPUTIL_P_OF15_OXM: {
          struct ofp11_flow_mod *ofm;
          int tailroom;
  
          tailroom = ofputil_match_typical_len(protocol) + fm->ofpacts_len;
          msg = ofpraw_alloc(OFPRAW_OFPT11_FLOW_MOD, version, tailroom);
          ofm = ofpbuf_put_zeros(msg, sizeof *ofm);
          if ((protocol == OFPUTIL_P_OF11_STD
               && (fm->command == OFPFC_MODIFY ||
                   fm->command == OFPFC_MODIFY_STRICT)
               && fm->cookie_mask == htonll(0))
              || fm->command == OFPFC_ADD) {
              ofm->cookie = fm->new_cookie;
          } else {
              ofm->cookie = fm->cookie & fm->cookie_mask;
          }
          ofm->cookie_mask = fm->cookie_mask;
          if (fm->table_id != OFPTT_ALL
              || (protocol != OFPUTIL_P_OF11_STD
                  && (fm->command == OFPFC_DELETE ||
                      fm->command == OFPFC_DELETE_STRICT))) {
              ofm->table_id = fm->table_id;
          } else {
              ofm->table_id = 0;
          }
          ofm->command = fm->command;
          ofm->idle_timeout = htons(fm->idle_timeout);
          ofm->hard_timeout = htons(fm->hard_timeout);
          ofm->priority = htons(fm->priority);
          ofm->buffer_id = htonl(fm->buffer_id);
          ofm->out_port = ofputil_port_to_ofp11(fm->out_port);
          ofm->out_group = htonl(fm->out_group);
          ofm->flags = raw_flags;
          if (version >= OFP14_VERSION && fm->command == OFPFC_ADD) {
              ofm->importance = htons(fm->importance);
          } else {
              ofm->importance = 0;
          }
          ofputil_put_ofp11_match(msg, &fm->match, protocol);
          ofpacts_put_openflow_instructions(fm->ofpacts, fm->ofpacts_len, msg,
                                            version);
          break;
      }
  
      case OFPUTIL_P_OF10_STD:
      case OFPUTIL_P_OF10_STD_TID: {
          struct ofp10_flow_mod *ofm;
  
          msg = ofpraw_alloc(OFPRAW_OFPT10_FLOW_MOD, OFP10_VERSION,
                             fm->ofpacts_len);
          ofm = ofpbuf_put_zeros(msg, sizeof *ofm);
          ofputil_match_to_ofp10_match(&fm->match, &ofm->match);
          ofm->cookie = fm->new_cookie;
          ofm->command = ofputil_tid_command(fm, protocol);
          ofm->idle_timeout = htons(fm->idle_timeout);
          ofm->hard_timeout = htons(fm->hard_timeout);
          ofm->priority = htons(fm->priority);
          ofm->buffer_id = htonl(fm->buffer_id);
          ofm->out_port = htons(ofp_to_u16(fm->out_port));
          ofm->flags = raw_flags;
          ofpacts_put_openflow_actions(fm->ofpacts, fm->ofpacts_len, msg,
                                       version);
          break;
      }
  
      case OFPUTIL_P_OF10_NXM:
      case OFPUTIL_P_OF10_NXM_TID: {
          struct nx_flow_mod *nfm;
          int match_len;
  
          msg = ofpraw_alloc(OFPRAW_NXT_FLOW_MOD, OFP10_VERSION,
                             NXM_TYPICAL_LEN + fm->ofpacts_len);
          nfm = ofpbuf_put_zeros(msg, sizeof *nfm);
          nfm->command = ofputil_tid_command(fm, protocol);
          nfm->cookie = fm->new_cookie;
          match_len = nx_put_match(msg, &fm->match, fm->cookie, fm->cookie_mask);
          nfm = msg->msg;
          nfm->idle_timeout = htons(fm->idle_timeout);
          nfm->hard_timeout = htons(fm->hard_timeout);
          nfm->priority = htons(fm->priority);
          nfm->buffer_id = htonl(fm->buffer_id);
          nfm->out_port = htons(ofp_to_u16(fm->out_port));
          nfm->flags = raw_flags;
          nfm->match_len = htons(match_len);
          ofpacts_put_openflow_actions(fm->ofpacts, fm->ofpacts_len, msg,
                                       version);
          break;
      }
  
      default:
          OVS_NOT_REACHED();
      }
  
      ofpmsg_update_length(msg);
      return msg;
  }
  
  static enum ofperr
  ofputil_decode_ofpst10_flow_request(struct ofputil_flow_stats_request *fsr,
                                      const struct ofp10_flow_stats_request *ofsr,
                                      bool aggregate)
  {
      fsr->aggregate = aggregate;
      ofputil_match_from_ofp10_match(&ofsr->match, &fsr->match);
      fsr->out_port = u16_to_ofp(ntohs(ofsr->out_port));
      fsr->out_group = OFPG11_ANY;
      fsr->table_id = ofsr->table_id;
      fsr->cookie = fsr->cookie_mask = htonll(0);
  
      return 0;
  }
  
  static enum ofperr
  ofputil_decode_ofpst11_flow_request(struct ofputil_flow_stats_request *fsr,
                                      struct ofpbuf *b, bool aggregate)
  {
      const struct ofp11_flow_stats_request *ofsr;
      enum ofperr error;
  
      ofsr = ofpbuf_pull(b, sizeof *ofsr);
      fsr->aggregate = aggregate;
      fsr->table_id = ofsr->table_id;
      error = ofputil_port_from_ofp11(ofsr->out_port, &fsr->out_port);
      if (error) {
          return error;
      }
      fsr->out_group = ntohl(ofsr->out_group);
      fsr->cookie = ofsr->cookie;
      fsr->cookie_mask = ofsr->cookie_mask;
      error = ofputil_pull_ofp11_match(b, &fsr->match, NULL);
      if (error) {
          return error;
      }
  
      return 0;
  }
  
  static enum ofperr
  ofputil_decode_nxst_flow_request(struct ofputil_flow_stats_request *fsr,
                                   struct ofpbuf *b, bool aggregate)
  {
      const struct nx_flow_stats_request *nfsr;
      enum ofperr error;
  
      nfsr = ofpbuf_pull(b, sizeof *nfsr);
      error = nx_pull_match(b, ntohs(nfsr->match_len), &fsr->match,
                            &fsr->cookie, &fsr->cookie_mask);
      if (error) {
          return error;
      }
      if (b->size) {
          return OFPERR_OFPBRC_BAD_LEN;
      }
  
      fsr->aggregate = aggregate;
      fsr->out_port = u16_to_ofp(ntohs(nfsr->out_port));
      fsr->out_group = OFPG11_ANY;
      fsr->table_id = nfsr->table_id;
  
      return 0;
  }
  
  /* Constructs and returns an OFPT_QUEUE_GET_CONFIG request for the specified
   * 'port', suitable for OpenFlow version 'version'. */
  struct ofpbuf *
  ofputil_encode_queue_get_config_request(enum ofp_version version,
                                          ofp_port_t port)
  {
      struct ofpbuf *request;
  
      if (version == OFP10_VERSION) {
          struct ofp10_queue_get_config_request *qgcr10;
  
          request = ofpraw_alloc(OFPRAW_OFPT10_QUEUE_GET_CONFIG_REQUEST,
                                 version, 0);
          qgcr10 = ofpbuf_put_zeros(request, sizeof *qgcr10);
          qgcr10->port = htons(ofp_to_u16(port));
      } else {
          struct ofp11_queue_get_config_request *qgcr11;
  
          request = ofpraw_alloc(OFPRAW_OFPT11_QUEUE_GET_CONFIG_REQUEST,
                                 version, 0);
          qgcr11 = ofpbuf_put_zeros(request, sizeof *qgcr11);
          qgcr11->port = ofputil_port_to_ofp11(port);
      }
  
      return request;
  }
  
  /* Parses OFPT_QUEUE_GET_CONFIG request 'oh', storing the port specified by the
   * request into '*port'.  Returns 0 if successful, otherwise an OpenFlow error
   * code. */
  enum ofperr
  ofputil_decode_queue_get_config_request(const struct ofp_header *oh,
                                          ofp_port_t *port)
  {
      const struct ofp10_queue_get_config_request *qgcr10;
      const struct ofp11_queue_get_config_request *qgcr11;
      enum ofpraw raw;
      struct ofpbuf b;
  
      ofpbuf_use_const(&b, oh, ntohs(oh->length));
      raw = ofpraw_pull_assert(&b);
  
      switch ((int) raw) {
      case OFPRAW_OFPT10_QUEUE_GET_CONFIG_REQUEST:
          qgcr10 = b.data;
          *port = u16_to_ofp(ntohs(qgcr10->port));
          return 0;
  
      case OFPRAW_OFPT11_QUEUE_GET_CONFIG_REQUEST:
          qgcr11 = b.data;
          return ofputil_port_from_ofp11(qgcr11->port, port);
      }
  
      OVS_NOT_REACHED();
  }
  
  /* Constructs and returns the beginning of a reply to
   * OFPT_QUEUE_GET_CONFIG_REQUEST 'oh'.  The caller may append information about
   * individual queues with ofputil_append_queue_get_config_reply(). */
  struct ofpbuf *
  ofputil_encode_queue_get_config_reply(const struct ofp_header *oh)
  {
      struct ofp10_queue_get_config_reply *qgcr10;
      struct ofp11_queue_get_config_reply *qgcr11;
      struct ofpbuf *reply;
      enum ofperr error;
      struct ofpbuf b;
      enum ofpraw raw;
      ofp_port_t port;
  
      error = ofputil_decode_queue_get_config_request(oh, &port);
      ovs_assert(!error);
  
      ofpbuf_use_const(&b, oh, ntohs(oh->length));
      raw = ofpraw_pull_assert(&b);
  
      switch ((int) raw) {
      case OFPRAW_OFPT10_QUEUE_GET_CONFIG_REQUEST:
          reply = ofpraw_alloc_reply(OFPRAW_OFPT10_QUEUE_GET_CONFIG_REPLY,
                                     oh, 0);
          qgcr10 = ofpbuf_put_zeros(reply, sizeof *qgcr10);
          qgcr10->port = htons(ofp_to_u16(port));
          break;
  
      case OFPRAW_OFPT11_QUEUE_GET_CONFIG_REQUEST:
          reply = ofpraw_alloc_reply(OFPRAW_OFPT11_QUEUE_GET_CONFIG_REPLY,
                                     oh, 0);
          qgcr11 = ofpbuf_put_zeros(reply, sizeof *qgcr11);
          qgcr11->port = ofputil_port_to_ofp11(port);
          break;
  
      default:
          OVS_NOT_REACHED();
      }
  
      return reply;
  }
  
  static void
  put_queue_rate(struct ofpbuf *reply, enum ofp_queue_properties property,
                 uint16_t rate)
  {
      if (rate != UINT16_MAX) {
          struct ofp_queue_prop_rate *oqpr;
  
          oqpr = ofpbuf_put_zeros(reply, sizeof *oqpr);
          oqpr->prop_header.property = htons(property);
          oqpr->prop_header.len = htons(sizeof *oqpr);
          oqpr->rate = htons(rate);
      }
  }
  
  /* Appends a queue description for 'queue_id' to the
   * OFPT_QUEUE_GET_CONFIG_REPLY already in 'oh'. */
  void
  ofputil_append_queue_get_config_reply(struct ofpbuf *reply,
                                        const struct ofputil_queue_config *oqc)
  {
      const struct ofp_header *oh = reply->data;
      size_t start_ofs, len_ofs;
      ovs_be16 *len;
  
      start_ofs = reply->size;
      if (oh->version < OFP12_VERSION) {
          struct ofp10_packet_queue *opq10;
  
          opq10 = ofpbuf_put_zeros(reply, sizeof *opq10);
          opq10->queue_id = htonl(oqc->queue_id);
          len_ofs = (char *) &opq10->len - (char *) reply->data;
      } else {
          struct ofp11_queue_get_config_reply *qgcr11;
          struct ofp12_packet_queue *opq12;
          ovs_be32 port;
  
          qgcr11 = reply->msg;
          port = qgcr11->port;
  
          opq12 = ofpbuf_put_zeros(reply, sizeof *opq12);
          opq12->port = port;
          opq12->queue_id = htonl(oqc->queue_id);
          len_ofs = (char *) &opq12->len - (char *) reply->data;
      }
  
      put_queue_rate(reply, OFPQT_MIN_RATE, oqc->min_rate);
      put_queue_rate(reply, OFPQT_MAX_RATE, oqc->max_rate);
  
      len = ofpbuf_at(reply, len_ofs, sizeof *len);
      *len = htons(reply->size - start_ofs);
  }
  
  /* Decodes the initial part of an OFPT_QUEUE_GET_CONFIG_REPLY from 'reply' and
   * stores in '*port' the port that the reply is about.  The caller may call
   * ofputil_pull_queue_get_config_reply() to obtain information about individual
   * queues included in the reply.  Returns 0 if successful, otherwise an
   * ofperr.*/
  enum ofperr
  ofputil_decode_queue_get_config_reply(struct ofpbuf *reply, ofp_port_t *port)
  {
      const struct ofp10_queue_get_config_reply *qgcr10;
      const struct ofp11_queue_get_config_reply *qgcr11;
      enum ofpraw raw;
  
      raw = ofpraw_pull_assert(reply);
      switch ((int) raw) {
      case OFPRAW_OFPT10_QUEUE_GET_CONFIG_REPLY:
          qgcr10 = ofpbuf_pull(reply, sizeof *qgcr10);
          *port = u16_to_ofp(ntohs(qgcr10->port));
          return 0;
  
      case OFPRAW_OFPT11_QUEUE_GET_CONFIG_REPLY:
          qgcr11 = ofpbuf_pull(reply, sizeof *qgcr11);
          return ofputil_port_from_ofp11(qgcr11->port, port);
      }
  
      OVS_NOT_REACHED();
  }
  
  static enum ofperr
  parse_queue_rate(const struct ofp_queue_prop_header *hdr, uint16_t *rate)
  {
      const struct ofp_queue_prop_rate *oqpr;
  
      if (hdr->len == htons(sizeof *oqpr)) {
          oqpr = (const struct ofp_queue_prop_rate *) hdr;
          *rate = ntohs(oqpr->rate);
          return 0;
      } else {
          return OFPERR_OFPBRC_BAD_LEN;
      }
  }
  
  /* Decodes information about a queue from the OFPT_QUEUE_GET_CONFIG_REPLY in
   * 'reply' and stores it in '*queue'.  ofputil_decode_queue_get_config_reply()
   * must already have pulled off the main header.
   *
   * This function returns EOF if the last queue has already been decoded, 0 if a
   * queue was successfully decoded into '*queue', or an ofperr if there was a
   * problem decoding 'reply'. */
  int
  ofputil_pull_queue_get_config_reply(struct ofpbuf *reply,
                                      struct ofputil_queue_config *queue)
  {
      const struct ofp_header *oh;
      unsigned int opq_len;
      unsigned int len;
  
      if (!reply->size) {
          return EOF;
      }
  
      queue->min_rate = UINT16_MAX;
      queue->max_rate = UINT16_MAX;
  
      oh = reply->header;
      if (oh->version < OFP12_VERSION) {
          const struct ofp10_packet_queue *opq10;
  
          opq10 = ofpbuf_try_pull(reply, sizeof *opq10);
          if (!opq10) {
              return OFPERR_OFPBRC_BAD_LEN;
          }
          queue->queue_id = ntohl(opq10->queue_id);
          len = ntohs(opq10->len);
          opq_len = sizeof *opq10;
      } else {
          const struct ofp12_packet_queue *opq12;
  
          opq12 = ofpbuf_try_pull(reply, sizeof *opq12);
          if (!opq12) {
              return OFPERR_OFPBRC_BAD_LEN;
          }
          queue->queue_id = ntohl(opq12->queue_id);
          len = ntohs(opq12->len);
          opq_len = sizeof *opq12;
      }
  
      if (len < opq_len || len > reply->size + opq_len || len % 8) {
          return OFPERR_OFPBRC_BAD_LEN;
      }
      len -= opq_len;
  
      while (len > 0) {
          const struct ofp_queue_prop_header *hdr;
          unsigned int property;
          unsigned int prop_len;
          enum ofperr error = 0;
  
          hdr = ofpbuf_at_assert(reply, 0, sizeof *hdr);
          prop_len = ntohs(hdr->len);
          if (prop_len < sizeof *hdr || prop_len > reply->size || prop_len % 8) {
              return OFPERR_OFPBRC_BAD_LEN;
          }
  
          property = ntohs(hdr->property);
          switch (property) {
          case OFPQT_MIN_RATE:
              error = parse_queue_rate(hdr, &queue->min_rate);
              break;
  
          case OFPQT_MAX_RATE:
              error = parse_queue_rate(hdr, &queue->max_rate);
              break;
  
          default:
              VLOG_INFO_RL(&bad_ofmsg_rl, "unknown queue property %u", property);
              break;
          }
          if (error) {
              return error;
          }
  
          ofpbuf_pull(reply, prop_len);
          len -= prop_len;
      }
      return 0;
  }
  
  /* Converts an OFPST_FLOW, OFPST_AGGREGATE, NXST_FLOW, or NXST_AGGREGATE
   * request 'oh', into an abstract flow_stats_request in 'fsr'.  Returns 0 if
   * successful, otherwise an OpenFlow error code. */
  enum ofperr
  ofputil_decode_flow_stats_request(struct ofputil_flow_stats_request *fsr,
                                    const struct ofp_header *oh)
  {
      enum ofpraw raw;
      struct ofpbuf b;
  
      ofpbuf_use_const(&b, oh, ntohs(oh->length));
      raw = ofpraw_pull_assert(&b);
      switch ((int) raw) {
      case OFPRAW_OFPST10_FLOW_REQUEST:
          return ofputil_decode_ofpst10_flow_request(fsr, b.data, false);
  
      case OFPRAW_OFPST10_AGGREGATE_REQUEST:
          return ofputil_decode_ofpst10_flow_request(fsr, b.data, true);
  
      case OFPRAW_OFPST11_FLOW_REQUEST:
          return ofputil_decode_ofpst11_flow_request(fsr, &b, false);
  
      case OFPRAW_OFPST11_AGGREGATE_REQUEST:
          return ofputil_decode_ofpst11_flow_request(fsr, &b, true);
  
      case OFPRAW_NXST_FLOW_REQUEST:
          return ofputil_decode_nxst_flow_request(fsr, &b, false);
  
      case OFPRAW_NXST_AGGREGATE_REQUEST:
          return ofputil_decode_nxst_flow_request(fsr, &b, true);
  
      default:
          /* Hey, the caller lied. */
          OVS_NOT_REACHED();
      }
  }
  
  /* Converts abstract flow_stats_request 'fsr' into an OFPST_FLOW,
   * OFPST_AGGREGATE, NXST_FLOW, or NXST_AGGREGATE request 'oh' according to
   * 'protocol', and returns the message. */
  struct ofpbuf *
  ofputil_encode_flow_stats_request(const struct ofputil_flow_stats_request *fsr,
                                    enum ofputil_protocol protocol)
  {
      struct ofpbuf *msg;
      enum ofpraw raw;
  
      switch (protocol) {
      case OFPUTIL_P_OF11_STD:
      case OFPUTIL_P_OF12_OXM:
      case OFPUTIL_P_OF13_OXM:
      case OFPUTIL_P_OF14_OXM:
      case OFPUTIL_P_OF15_OXM: {
          struct ofp11_flow_stats_request *ofsr;
  
          raw = (fsr->aggregate
                 ? OFPRAW_OFPST11_AGGREGATE_REQUEST
                 : OFPRAW_OFPST11_FLOW_REQUEST);
          msg = ofpraw_alloc(raw, ofputil_protocol_to_ofp_version(protocol),
                             ofputil_match_typical_len(protocol));
          ofsr = ofpbuf_put_zeros(msg, sizeof *ofsr);
          ofsr->table_id = fsr->table_id;
          ofsr->out_port = ofputil_port_to_ofp11(fsr->out_port);
          ofsr->out_group = htonl(fsr->out_group);
          ofsr->cookie = fsr->cookie;
          ofsr->cookie_mask = fsr->cookie_mask;
          ofputil_put_ofp11_match(msg, &fsr->match, protocol);
          break;
      }
  
      case OFPUTIL_P_OF10_STD:
      case OFPUTIL_P_OF10_STD_TID: {
          struct ofp10_flow_stats_request *ofsr;
  
          raw = (fsr->aggregate
                 ? OFPRAW_OFPST10_AGGREGATE_REQUEST
                 : OFPRAW_OFPST10_FLOW_REQUEST);
          msg = ofpraw_alloc(raw, OFP10_VERSION, 0);
          ofsr = ofpbuf_put_zeros(msg, sizeof *ofsr);
          ofputil_match_to_ofp10_match(&fsr->match, &ofsr->match);
          ofsr->table_id = fsr->table_id;
          ofsr->out_port = htons(ofp_to_u16(fsr->out_port));
          break;
      }
  
      case OFPUTIL_P_OF10_NXM:
      case OFPUTIL_P_OF10_NXM_TID: {
          struct nx_flow_stats_request *nfsr;
          int match_len;
  
          raw = (fsr->aggregate
                 ? OFPRAW_NXST_AGGREGATE_REQUEST
                 : OFPRAW_NXST_FLOW_REQUEST);
          msg = ofpraw_alloc(raw, OFP10_VERSION, NXM_TYPICAL_LEN);
          ofpbuf_put_zeros(msg, sizeof *nfsr);
          match_len = nx_put_match(msg, &fsr->match,
                                   fsr->cookie, fsr->cookie_mask);
  
          nfsr = msg->msg;
          nfsr->out_port = htons(ofp_to_u16(fsr->out_port));
          nfsr->match_len = htons(match_len);
          nfsr->table_id = fsr->table_id;
          break;
      }
  
      default:
          OVS_NOT_REACHED();
      }
  
      return msg;
  }
  
  /* Converts an OFPST_FLOW or NXST_FLOW reply in 'msg' into an abstract
   * ofputil_flow_stats in 'fs'.
   *
   * Multiple OFPST_FLOW or NXST_FLOW replies can be packed into a single
   * OpenFlow message.  Calling this function multiple times for a single 'msg'
   * iterates through the replies.  The caller must initially leave 'msg''s layer
   * pointers null and not modify them between calls.
   *
   * Most switches don't send the values needed to populate fs->idle_age and
   * fs->hard_age, so those members will usually be set to 0.  If the switch from
   * which 'msg' originated is known to implement NXT_FLOW_AGE, then pass
   * 'flow_age_extension' as true so that the contents of 'msg' determine the
   * 'idle_age' and 'hard_age' members in 'fs'.
   *
   * Uses 'ofpacts' to store the abstract OFPACT_* version of the flow stats
   * reply's actions.  The caller must initialize 'ofpacts' and retains ownership
   * of it.  'fs->ofpacts' will point into the 'ofpacts' buffer.
   *
   * Returns 0 if successful, EOF if no replies were left in this 'msg',
   * otherwise a positive errno value. */
  int
  ofputil_decode_flow_stats_reply(struct ofputil_flow_stats *fs,
                                  struct ofpbuf *msg,
                                  bool flow_age_extension,
                                  struct ofpbuf *ofpacts)
  {
      const struct ofp_header *oh;
      size_t instructions_len;
      enum ofperr error;
      enum ofpraw raw;
  
      error = (msg->header ? ofpraw_decode(&raw, msg->header)
               : ofpraw_pull(&raw, msg));
      if (error) {
          return error;
      }
      oh = msg->header;
  
      if (!msg->size) {
          return EOF;
      } else if (raw == OFPRAW_OFPST11_FLOW_REPLY
                 || raw == OFPRAW_OFPST13_FLOW_REPLY) {
          const struct ofp11_flow_stats *ofs;
          size_t length;
          uint16_t padded_match_len;
  
          ofs = ofpbuf_try_pull(msg, sizeof *ofs);
          if (!ofs) {
              VLOG_WARN_RL(&bad_ofmsg_rl, "OFPST_FLOW reply has %"PRIu32" leftover "
                           "bytes at end", msg->size);
              return EINVAL;
          }
  
          length = ntohs(ofs->length);
          if (length < sizeof *ofs) {
              VLOG_WARN_RL(&bad_ofmsg_rl, "OFPST_FLOW reply claims invalid "
                           "length %"PRIuSIZE, length);
              return EINVAL;
          }
  
          if (ofputil_pull_ofp11_match(msg, &fs->match, &padded_match_len)) {
              VLOG_WARN_RL(&bad_ofmsg_rl, "OFPST_FLOW reply bad match");
              return EINVAL;
          }
          instructions_len = length - sizeof *ofs - padded_match_len;
  
          fs->priority = ntohs(ofs->priority);
          fs->table_id = ofs->table_id;
          fs->duration_sec = ntohl(ofs->duration_sec);
          fs->duration_nsec = ntohl(ofs->duration_nsec);
          fs->idle_timeout = ntohs(ofs->idle_timeout);
          fs->hard_timeout = ntohs(ofs->hard_timeout);
          if (oh->version >= OFP14_VERSION) {
              fs->importance = ntohs(ofs->importance);
          } else {
              fs->importance = 0;
          }
          if (raw == OFPRAW_OFPST13_FLOW_REPLY) {
              error = ofputil_decode_flow_mod_flags(ofs->flags, -1, oh->version,
                                                    &fs->flags);
              if (error) {
                  return error;
              }
          } else {
              fs->flags = 0;
          }
          fs->idle_age = -1;
          fs->hard_age = -1;
          fs->cookie = ofs->cookie;
          fs->packet_count = ntohll(ofs->packet_count);
          fs->byte_count = ntohll(ofs->byte_count);
      } else if (raw == OFPRAW_OFPST10_FLOW_REPLY) {
          const struct ofp10_flow_stats *ofs;
          size_t length;
  
          ofs = ofpbuf_try_pull(msg, sizeof *ofs);
          if (!ofs) {
              VLOG_WARN_RL(&bad_ofmsg_rl, "OFPST_FLOW reply has %"PRIu32" leftover "
                           "bytes at end", msg->size);
              return EINVAL;
          }
  
          length = ntohs(ofs->length);
          if (length < sizeof *ofs) {
              VLOG_WARN_RL(&bad_ofmsg_rl, "OFPST_FLOW reply claims invalid "
                           "length %"PRIuSIZE, length);
              return EINVAL;
          }
          instructions_len = length - sizeof *ofs;
  
          fs->cookie = get_32aligned_be64(&ofs->cookie);
          ofputil_match_from_ofp10_match(&ofs->match, &fs->match);
          fs->priority = ntohs(ofs->priority);
          fs->table_id = ofs->table_id;
          fs->duration_sec = ntohl(ofs->duration_sec);
          fs->duration_nsec = ntohl(ofs->duration_nsec);
          fs->idle_timeout = ntohs(ofs->idle_timeout);
          fs->hard_timeout = ntohs(ofs->hard_timeout);
          fs->importance = 0;
          fs->idle_age = -1;
          fs->hard_age = -1;
          fs->packet_count = ntohll(get_32aligned_be64(&ofs->packet_count));
          fs->byte_count = ntohll(get_32aligned_be64(&ofs->byte_count));
          fs->flags = 0;
      } else if (raw == OFPRAW_NXST_FLOW_REPLY) {
          const struct nx_flow_stats *nfs;
          size_t match_len, length;
  
          nfs = ofpbuf_try_pull(msg, sizeof *nfs);
          if (!nfs) {
              VLOG_WARN_RL(&bad_ofmsg_rl, "NXST_FLOW reply has %"PRIu32" leftover "
                           "bytes at end", msg->size);
              return EINVAL;
          }
  
          length = ntohs(nfs->length);
          match_len = ntohs(nfs->match_len);
          if (length < sizeof *nfs + ROUND_UP(match_len, 8)) {
              VLOG_WARN_RL(&bad_ofmsg_rl, "NXST_FLOW reply with match_len=%"PRIuSIZE" "
                           "claims invalid length %"PRIuSIZE, match_len, length);
              return EINVAL;
          }
          if (nx_pull_match(msg, match_len, &fs->match, NULL, NULL)) {
              return EINVAL;
          }
          instructions_len = length - sizeof *nfs - ROUND_UP(match_len, 8);
  
          fs->cookie = nfs->cookie;
          fs->table_id = nfs->table_id;
          fs->duration_sec = ntohl(nfs->duration_sec);
          fs->duration_nsec = ntohl(nfs->duration_nsec);
          fs->priority = ntohs(nfs->priority);
          fs->idle_timeout = ntohs(nfs->idle_timeout);
          fs->hard_timeout = ntohs(nfs->hard_timeout);
          fs->importance = 0;
          fs->idle_age = -1;
          fs->hard_age = -1;
          if (flow_age_extension) {
              if (nfs->idle_age) {
                  fs->idle_age = ntohs(nfs->idle_age) - 1;
              }
              if (nfs->hard_age) {
                  fs->hard_age = ntohs(nfs->hard_age) - 1;
              }
          }
          fs->packet_count = ntohll(nfs->packet_count);
          fs->byte_count = ntohll(nfs->byte_count);
          fs->flags = 0;
      } else {
          OVS_NOT_REACHED();
      }
  
      if (ofpacts_pull_openflow_instructions(msg, instructions_len, oh->version,
                                             ofpacts)) {
          VLOG_WARN_RL(&bad_ofmsg_rl, "OFPST_FLOW reply bad instructions");
          return EINVAL;
      }
      fs->ofpacts = ofpacts->data;
      fs->ofpacts_len = ofpacts->size;
  
      return 0;
  }
  
  /* Returns 'count' unchanged except that UINT64_MAX becomes 0.
   *
   * We use this in situations where OVS internally uses UINT64_MAX to mean
   * "value unknown" but OpenFlow 1.0 does not define any unknown value. */
  static uint64_t
  unknown_to_zero(uint64_t count)
  {
      return count != UINT64_MAX ? count : 0;
  }
  
  /* Appends an OFPST_FLOW or NXST_FLOW reply that contains the data in 'fs' to
   * those already present in the list of ofpbufs in 'replies'.  'replies' should
   * have been initialized with ofpmp_init(). */
  void
  ofputil_append_flow_stats_reply(const struct ofputil_flow_stats *fs,
                                  struct ovs_list *replies)
  {
      struct ofpbuf *reply = ofpbuf_from_list(list_back(replies));
      size_t start_ofs = reply->size;
      enum ofp_version version = ofpmp_version(replies);
      enum ofpraw raw = ofpmp_decode_raw(replies);
  
      if (raw == OFPRAW_OFPST11_FLOW_REPLY || raw == OFPRAW_OFPST13_FLOW_REPLY) {
          struct ofp11_flow_stats *ofs;
  
          ofpbuf_put_uninit(reply, sizeof *ofs);
          oxm_put_match(reply, &fs->match, version);
          ofpacts_put_openflow_instructions(fs->ofpacts, fs->ofpacts_len, reply,
                                            version);
  
          ofs = ofpbuf_at_assert(reply, start_ofs, sizeof *ofs);
          ofs->length = htons(reply->size - start_ofs);
          ofs->table_id = fs->table_id;
          ofs->pad = 0;
          ofs->duration_sec = htonl(fs->duration_sec);
          ofs->duration_nsec = htonl(fs->duration_nsec);
          ofs->priority = htons(fs->priority);
          ofs->idle_timeout = htons(fs->idle_timeout);
          ofs->hard_timeout = htons(fs->hard_timeout);
          if (version >= OFP14_VERSION) {
              ofs->importance = htons(fs->importance);
          } else {
              ofs->importance = 0;
          }
          if (raw == OFPRAW_OFPST13_FLOW_REPLY) {
              ofs->flags = ofputil_encode_flow_mod_flags(fs->flags, version);
          } else {
              ofs->flags = 0;
          }
          memset(ofs->pad2, 0, sizeof ofs->pad2);
          ofs->cookie = fs->cookie;
          ofs->packet_count = htonll(unknown_to_zero(fs->packet_count));
          ofs->byte_count = htonll(unknown_to_zero(fs->byte_count));
      } else if (raw == OFPRAW_OFPST10_FLOW_REPLY) {
          struct ofp10_flow_stats *ofs;
  
          ofpbuf_put_uninit(reply, sizeof *ofs);
          ofpacts_put_openflow_actions(fs->ofpacts, fs->ofpacts_len, reply,
                                       version);
          ofs = ofpbuf_at_assert(reply, start_ofs, sizeof *ofs);
          ofs->length = htons(reply->size - start_ofs);
          ofs->table_id = fs->table_id;
          ofs->pad = 0;
          ofputil_match_to_ofp10_match(&fs->match, &ofs->match);
          ofs->duration_sec = htonl(fs->duration_sec);
          ofs->duration_nsec = htonl(fs->duration_nsec);
          ofs->priority = htons(fs->priority);
          ofs->idle_timeout = htons(fs->idle_timeout);
          ofs->hard_timeout = htons(fs->hard_timeout);
          memset(ofs->pad2, 0, sizeof ofs->pad2);
          put_32aligned_be64(&ofs->cookie, fs->cookie);
          put_32aligned_be64(&ofs->packet_count,
                             htonll(unknown_to_zero(fs->packet_count)));
          put_32aligned_be64(&ofs->byte_count,
                             htonll(unknown_to_zero(fs->byte_count)));
      } else if (raw == OFPRAW_NXST_FLOW_REPLY) {
          struct nx_flow_stats *nfs;
          int match_len;
  
          ofpbuf_put_uninit(reply, sizeof *nfs);
          match_len = nx_put_match(reply, &fs->match, 0, 0);
          ofpacts_put_openflow_actions(fs->ofpacts, fs->ofpacts_len, reply,
                                       version);
          nfs = ofpbuf_at_assert(reply, start_ofs, sizeof *nfs);
          nfs->length = htons(reply->size - start_ofs);
          nfs->table_id = fs->table_id;
          nfs->pad = 0;
          nfs->duration_sec = htonl(fs->duration_sec);
          nfs->duration_nsec = htonl(fs->duration_nsec);
          nfs->priority = htons(fs->priority);
          nfs->idle_timeout = htons(fs->idle_timeout);
          nfs->hard_timeout = htons(fs->hard_timeout);
          nfs->idle_age = htons(fs->idle_age < 0 ? 0
                                : fs->idle_age < UINT16_MAX ? fs->idle_age + 1
                                : UINT16_MAX);
          nfs->hard_age = htons(fs->hard_age < 0 ? 0
                                : fs->hard_age < UINT16_MAX ? fs->hard_age + 1
                                : UINT16_MAX);
          nfs->match_len = htons(match_len);
          nfs->cookie = fs->cookie;
          nfs->packet_count = htonll(fs->packet_count);
          nfs->byte_count = htonll(fs->byte_count);
      } else {
          OVS_NOT_REACHED();
      }
  
      ofpmp_postappend(replies, start_ofs);
  }
  
  /* Converts abstract ofputil_aggregate_stats 'stats' into an OFPST_AGGREGATE or
   * NXST_AGGREGATE reply matching 'request', and returns the message. */
  struct ofpbuf *
  ofputil_encode_aggregate_stats_reply(
      const struct ofputil_aggregate_stats *stats,
      const struct ofp_header *request)
  {
      struct ofp_aggregate_stats_reply *asr;
      uint64_t packet_count;
      uint64_t byte_count;
      struct ofpbuf *msg;
      enum ofpraw raw;
  
      ofpraw_decode(&raw, request);
      if (raw == OFPRAW_OFPST10_AGGREGATE_REQUEST) {
          packet_count = unknown_to_zero(stats->packet_count);
          byte_count = unknown_to_zero(stats->byte_count);
      } else {
          packet_count = stats->packet_count;
          byte_count = stats->byte_count;
      }
  
      msg = ofpraw_alloc_stats_reply(request, 0);
      asr = ofpbuf_put_zeros(msg, sizeof *asr);
      put_32aligned_be64(&asr->packet_count, htonll(packet_count));
      put_32aligned_be64(&asr->byte_count, htonll(byte_count));
      asr->flow_count = htonl(stats->flow_count);
  
      return msg;
  }
  
  enum ofperr
  ofputil_decode_aggregate_stats_reply(struct ofputil_aggregate_stats *stats,
                                       const struct ofp_header *reply)
  {
      struct ofp_aggregate_stats_reply *asr;
      struct ofpbuf msg;
  
      ofpbuf_use_const(&msg, reply, ntohs(reply->length));
      ofpraw_pull_assert(&msg);
  
      asr = msg.msg;
      stats->packet_count = ntohll(get_32aligned_be64(&asr->packet_count));
      stats->byte_count = ntohll(get_32aligned_be64(&asr->byte_count));
      stats->flow_count = ntohl(asr->flow_count);
  
      return 0;
  }
  
  /* Converts an OFPT_FLOW_REMOVED or NXT_FLOW_REMOVED message 'oh' into an
   * abstract ofputil_flow_removed in 'fr'.  Returns 0 if successful, otherwise
   * an OpenFlow error code. */
  enum ofperr
  ofputil_decode_flow_removed(struct ofputil_flow_removed *fr,
                              const struct ofp_header *oh)
  {
      enum ofpraw raw;
      struct ofpbuf b;
  
      ofpbuf_use_const(&b, oh, ntohs(oh->length));
      raw = ofpraw_pull_assert(&b);
      if (raw == OFPRAW_OFPT11_FLOW_REMOVED) {
          const struct ofp12_flow_removed *ofr;
          enum ofperr error;
  
          ofr = ofpbuf_pull(&b, sizeof *ofr);
  
          error = ofputil_pull_ofp11_match(&b, &fr->match, NULL);
          if (error) {
              return error;
          }
  
          fr->priority = ntohs(ofr->priority);
          fr->cookie = ofr->cookie;
          fr->reason = ofr->reason;
          fr->table_id = ofr->table_id;
          fr->duration_sec = ntohl(ofr->duration_sec);
          fr->duration_nsec = ntohl(ofr->duration_nsec);
          fr->idle_timeout = ntohs(ofr->idle_timeout);
          fr->hard_timeout = ntohs(ofr->hard_timeout);
          fr->packet_count = ntohll(ofr->packet_count);
          fr->byte_count = ntohll(ofr->byte_count);
      } else if (raw == OFPRAW_OFPT10_FLOW_REMOVED) {
          const struct ofp10_flow_removed *ofr;
  
          ofr = ofpbuf_pull(&b, sizeof *ofr);
  
          ofputil_match_from_ofp10_match(&ofr->match, &fr->match);
          fr->priority = ntohs(ofr->priority);
          fr->cookie = ofr->cookie;
          fr->reason = ofr->reason;
          fr->table_id = 255;
          fr->duration_sec = ntohl(ofr->duration_sec);
          fr->duration_nsec = ntohl(ofr->duration_nsec);
          fr->idle_timeout = ntohs(ofr->idle_timeout);
          fr->hard_timeout = 0;
          fr->packet_count = ntohll(ofr->packet_count);
          fr->byte_count = ntohll(ofr->byte_count);
      } else if (raw == OFPRAW_NXT_FLOW_REMOVED) {
          struct nx_flow_removed *nfr;
          enum ofperr error;
  
          nfr = ofpbuf_pull(&b, sizeof *nfr);
          error = nx_pull_match(&b, ntohs(nfr->match_len), &fr->match,
                                NULL, NULL);
          if (error) {
              return error;
          }
          if (b.size) {
              return OFPERR_OFPBRC_BAD_LEN;
          }
  
          fr->priority = ntohs(nfr->priority);
          fr->cookie = nfr->cookie;
          fr->reason = nfr->reason;
          fr->table_id = nfr->table_id ? nfr->table_id - 1 : 255;
          fr->duration_sec = ntohl(nfr->duration_sec);
          fr->duration_nsec = ntohl(nfr->duration_nsec);
          fr->idle_timeout = ntohs(nfr->idle_timeout);
          fr->hard_timeout = 0;
          fr->packet_count = ntohll(nfr->packet_count);
          fr->byte_count = ntohll(nfr->byte_count);
      } else {
          OVS_NOT_REACHED();
      }
  
      return 0;
  }
  
  /* Converts abstract ofputil_flow_removed 'fr' into an OFPT_FLOW_REMOVED or
   * NXT_FLOW_REMOVED message 'oh' according to 'protocol', and returns the
   * message. */
  struct ofpbuf *
  ofputil_encode_flow_removed(const struct ofputil_flow_removed *fr,
                              enum ofputil_protocol protocol)
  {
      struct ofpbuf *msg;
      enum ofp_flow_removed_reason reason = fr->reason;
  
      if (reason == OFPRR_METER_DELETE && !(protocol & OFPUTIL_P_OF14_UP)) {
          reason = OFPRR_DELETE;
      }
  
      switch (protocol) {
      case OFPUTIL_P_OF11_STD:
      case OFPUTIL_P_OF12_OXM:
      case OFPUTIL_P_OF13_OXM:
      case OFPUTIL_P_OF14_OXM:
      case OFPUTIL_P_OF15_OXM: {
          struct ofp12_flow_removed *ofr;
  
          msg = ofpraw_alloc_xid(OFPRAW_OFPT11_FLOW_REMOVED,
                                 ofputil_protocol_to_ofp_version(protocol),
                                 htonl(0),
                                 ofputil_match_typical_len(protocol));
          ofr = ofpbuf_put_zeros(msg, sizeof *ofr);
          ofr->cookie = fr->cookie;
          ofr->priority = htons(fr->priority);
          ofr->reason = reason;
          ofr->table_id = fr->table_id;
          ofr->duration_sec = htonl(fr->duration_sec);
          ofr->duration_nsec = htonl(fr->duration_nsec);
          ofr->idle_timeout = htons(fr->idle_timeout);
          ofr->hard_timeout = htons(fr->hard_timeout);
          ofr->packet_count = htonll(fr->packet_count);
          ofr->byte_count = htonll(fr->byte_count);
          ofputil_put_ofp11_match(msg, &fr->match, protocol);
          break;
      }
  
      case OFPUTIL_P_OF10_STD:
      case OFPUTIL_P_OF10_STD_TID: {
          struct ofp10_flow_removed *ofr;
  
          msg = ofpraw_alloc_xid(OFPRAW_OFPT10_FLOW_REMOVED, OFP10_VERSION,
                                 htonl(0), 0);
          ofr = ofpbuf_put_zeros(msg, sizeof *ofr);
          ofputil_match_to_ofp10_match(&fr->match, &ofr->match);
          ofr->cookie = fr->cookie;
          ofr->priority = htons(fr->priority);
          ofr->reason = reason;
          ofr->duration_sec = htonl(fr->duration_sec);
          ofr->duration_nsec = htonl(fr->duration_nsec);
          ofr->idle_timeout = htons(fr->idle_timeout);
          ofr->packet_count = htonll(unknown_to_zero(fr->packet_count));
          ofr->byte_count = htonll(unknown_to_zero(fr->byte_count));
          break;
      }
  
      case OFPUTIL_P_OF10_NXM:
      case OFPUTIL_P_OF10_NXM_TID: {
          struct nx_flow_removed *nfr;
          int match_len;
  
          msg = ofpraw_alloc_xid(OFPRAW_NXT_FLOW_REMOVED, OFP10_VERSION,
                                 htonl(0), NXM_TYPICAL_LEN);
          ofpbuf_put_zeros(msg, sizeof *nfr);
          match_len = nx_put_match(msg, &fr->match, 0, 0);
  
          nfr = msg->msg;
          nfr->cookie = fr->cookie;
          nfr->priority = htons(fr->priority);
          nfr->reason = reason;
          nfr->table_id = fr->table_id + 1;
          nfr->duration_sec = htonl(fr->duration_sec);
          nfr->duration_nsec = htonl(fr->duration_nsec);
          nfr->idle_timeout = htons(fr->idle_timeout);
          nfr->match_len = htons(match_len);
          nfr->packet_count = htonll(fr->packet_count);
          nfr->byte_count = htonll(fr->byte_count);
          break;
      }
  
      default:
          OVS_NOT_REACHED();
      }
  
      return msg;
  }
  
  enum ofperr
  ofputil_decode_packet_in(struct ofputil_packet_in *pin,
                           const struct ofp_header *oh)
  {
      enum ofpraw raw;
      struct ofpbuf b;
  
      memset(pin, 0, sizeof *pin);
      pin->cookie = OVS_BE64_MAX;
  
      ofpbuf_use_const(&b, oh, ntohs(oh->length));
      raw = ofpraw_pull_assert(&b);
      if (raw == OFPRAW_OFPT13_PACKET_IN || raw == OFPRAW_OFPT12_PACKET_IN) {
          const struct ofp13_packet_in *opi;
          int error;
          size_t packet_in_size;
  
          if (raw == OFPRAW_OFPT12_PACKET_IN) {
              packet_in_size = sizeof (struct ofp12_packet_in);
          } else {
              packet_in_size = sizeof (struct ofp13_packet_in);
          }
  
          opi = ofpbuf_pull(&b, packet_in_size);
          error = oxm_pull_match_loose(&b, &pin->flow_metadata);
          if (error) {
              return error;
          }
  
          if (!ofpbuf_try_pull(&b, 2)) {
              return OFPERR_OFPBRC_BAD_LEN;
          }
  
          pin->reason = opi->pi.reason;
          pin->table_id = opi->pi.table_id;
          pin->buffer_id = ntohl(opi->pi.buffer_id);
          pin->total_len = ntohs(opi->pi.total_len);
  
          if (raw == OFPRAW_OFPT13_PACKET_IN) {
              pin->cookie = opi->cookie;
          }
  
          pin->packet = b.data;
          pin->packet_len = b.size;
      } else if (raw == OFPRAW_OFPT10_PACKET_IN) {
          const struct ofp10_packet_in *opi;
  
          opi = ofpbuf_pull(&b, offsetof(struct ofp10_packet_in, data));
  
          pin->packet = opi->data;
          pin->packet_len = b.size;
  
          match_init_catchall(&pin->flow_metadata);
          match_set_in_port(&pin->flow_metadata, u16_to_ofp(ntohs(opi->in_port)));
          pin->reason = opi->reason;
          pin->buffer_id = ntohl(opi->buffer_id);
          pin->total_len = ntohs(opi->total_len);
      } else if (raw == OFPRAW_OFPT11_PACKET_IN) {
          const struct ofp11_packet_in *opi;
          ofp_port_t in_port;
          enum ofperr error;
  
          opi = ofpbuf_pull(&b, sizeof *opi);
  
          pin->packet = b.data;
          pin->packet_len = b.size;
  
          pin->buffer_id = ntohl(opi->buffer_id);
          error = ofputil_port_from_ofp11(opi->in_port, &in_port);
          if (error) {
              return error;
          }
          match_init_catchall(&pin->flow_metadata);
          match_set_in_port(&pin->flow_metadata, in_port);
          pin->total_len = ntohs(opi->total_len);
          pin->reason = opi->reason;
          pin->table_id = opi->table_id;
      } else if (raw == OFPRAW_NXT_PACKET_IN) {
          const struct nx_packet_in *npi;
          int error;
  
          npi = ofpbuf_pull(&b, sizeof *npi);
          error = nx_pull_match_loose(&b, ntohs(npi->match_len),
                                      &pin->flow_metadata, NULL, NULL);
          if (error) {
              return error;
          }
  
          if (!ofpbuf_try_pull(&b, 2)) {
              return OFPERR_OFPBRC_BAD_LEN;
          }
  
          pin->reason = npi->reason;
          pin->table_id = npi->table_id;
          pin->cookie = npi->cookie;
  
          pin->buffer_id = ntohl(npi->buffer_id);
          pin->total_len = ntohs(npi->total_len);
  
          pin->packet = b.data;
          pin->packet_len = b.size;
      } else {
          OVS_NOT_REACHED();
      }
  
      return 0;
  }
  
  static struct ofpbuf *
  ofputil_encode_ofp10_packet_in(const struct ofputil_packet_in *pin)
  {
      struct ofp10_packet_in *opi;
      struct ofpbuf *packet;
  
      packet = ofpraw_alloc_xid(OFPRAW_OFPT10_PACKET_IN, OFP10_VERSION,
                                htonl(0), pin->packet_len);
      opi = ofpbuf_put_zeros(packet, offsetof(struct ofp10_packet_in, data));
      opi->total_len = htons(pin->total_len);
      opi->in_port = htons(ofp_to_u16(pin->flow_metadata.flow.in_port.ofp_port));
      opi->reason = pin->reason;
      opi->buffer_id = htonl(pin->buffer_id);
  
      ofpbuf_put(packet, pin->packet, pin->packet_len);
  
      return packet;
  }
  
  static struct ofpbuf *
  ofputil_encode_nx_packet_in(const struct ofputil_packet_in *pin)
  {
      struct nx_packet_in *npi;
      struct ofpbuf *packet;
      size_t match_len;
  
      /* The final argument is just an estimate of the space required. */
      packet = ofpraw_alloc_xid(OFPRAW_NXT_PACKET_IN, OFP10_VERSION,
                                htonl(0), NXM_TYPICAL_LEN + 2 + pin->packet_len);
      ofpbuf_put_zeros(packet, sizeof *npi);
      match_len = nx_put_match(packet, &pin->flow_metadata, 0, 0);
      ofpbuf_put_zeros(packet, 2);
      ofpbuf_put(packet, pin->packet, pin->packet_len);
  
      npi = packet->msg;
      npi->buffer_id = htonl(pin->buffer_id);
      npi->total_len = htons(pin->total_len);
      npi->reason = pin->reason;
      npi->table_id = pin->table_id;
      npi->cookie = pin->cookie;
      npi->match_len = htons(match_len);
  
      return packet;
  }
  
  static struct ofpbuf *
  ofputil_encode_ofp11_packet_in(const struct ofputil_packet_in *pin)
  {
      struct ofp11_packet_in *opi;
      struct ofpbuf *packet;
  
      packet = ofpraw_alloc_xid(OFPRAW_OFPT11_PACKET_IN, OFP11_VERSION,
                                htonl(0), pin->packet_len);
      opi = ofpbuf_put_zeros(packet, sizeof *opi);
      opi->buffer_id = htonl(pin->buffer_id);
      opi->in_port = ofputil_port_to_ofp11(pin->flow_metadata.flow.in_port.ofp_port);
      opi->in_phy_port = opi->in_port;
      opi->total_len = htons(pin->total_len);
      opi->reason = pin->reason;
      opi->table_id = pin->table_id;
  
      ofpbuf_put(packet, pin->packet, pin->packet_len);
  
      return packet;
  }
  
  static struct ofpbuf *
  ofputil_encode_ofp12_packet_in(const struct ofputil_packet_in *pin,
                                 enum ofputil_protocol protocol)
  {
      struct ofp13_packet_in *opi;
      enum ofpraw packet_in_raw;
      enum ofp_version packet_in_version;
      size_t packet_in_size;
      struct ofpbuf *packet;
  
      if (protocol == OFPUTIL_P_OF12_OXM) {
          packet_in_raw = OFPRAW_OFPT12_PACKET_IN;
          packet_in_version = OFP12_VERSION;
          packet_in_size = sizeof (struct ofp12_packet_in);
      } else {
          packet_in_raw = OFPRAW_OFPT13_PACKET_IN;
          packet_in_version = ofputil_protocol_to_ofp_version(protocol);
          packet_in_size = sizeof (struct ofp13_packet_in);
      }
  
      /* The final argument is just an estimate of the space required. */
      packet = ofpraw_alloc_xid(packet_in_raw, packet_in_version,
                                htonl(0), NXM_TYPICAL_LEN + 2 + pin->packet_len);
      ofpbuf_put_zeros(packet, packet_in_size);
      oxm_put_match(packet, &pin->flow_metadata,
                    ofputil_protocol_to_ofp_version(protocol));
      ofpbuf_put_zeros(packet, 2);
      ofpbuf_put(packet, pin->packet, pin->packet_len);
  
      opi = packet->msg;
      opi->pi.buffer_id = htonl(pin->buffer_id);
      opi->pi.total_len = htons(pin->total_len);
      opi->pi.reason = pin->reason;
      opi->pi.table_id = pin->table_id;
      if (protocol != OFPUTIL_P_OF12_OXM) {
          opi->cookie = pin->cookie;
      }
  
      return packet;
  }
  
  /* Converts abstract ofputil_packet_in 'pin' into a PACKET_IN message
   * in the format specified by 'packet_in_format'.  */
  struct ofpbuf *
  ofputil_encode_packet_in(const struct ofputil_packet_in *pin,
                           enum ofputil_protocol protocol,
                           enum nx_packet_in_format packet_in_format)
  {
      struct ofpbuf *packet;
  
      switch (protocol) {
      case OFPUTIL_P_OF10_STD:
      case OFPUTIL_P_OF10_STD_TID:
      case OFPUTIL_P_OF10_NXM:
      case OFPUTIL_P_OF10_NXM_TID:
          packet = (packet_in_format == NXPIF_NXM
                    ? ofputil_encode_nx_packet_in(pin)
                    : ofputil_encode_ofp10_packet_in(pin));
          break;
  
      case OFPUTIL_P_OF11_STD:
          packet = ofputil_encode_ofp11_packet_in(pin);
          break;
  
      case OFPUTIL_P_OF12_OXM:
      case OFPUTIL_P_OF13_OXM:
      case OFPUTIL_P_OF14_OXM:
      case OFPUTIL_P_OF15_OXM:
          packet = ofputil_encode_ofp12_packet_in(pin, protocol);
          break;
  
      default:
          OVS_NOT_REACHED();
      }
  
      ofpmsg_update_length(packet);
      return packet;
  }
  
  /* Returns a string form of 'reason'.  The return value is either a statically
   * allocated constant string or the 'bufsize'-byte buffer 'reasonbuf'.
   * 'bufsize' should be at least OFPUTIL_PACKET_IN_REASON_BUFSIZE. */
  const char *
  ofputil_packet_in_reason_to_string(enum ofp_packet_in_reason reason,
                                     char *reasonbuf, size_t bufsize)
  {
      switch (reason) {
      case OFPR_NO_MATCH:
          return "no_match";
      case OFPR_ACTION:
          return "action";
      case OFPR_INVALID_TTL:
          return "invalid_ttl";
      case OFPR_ACTION_SET:
          return "action_set";
      case OFPR_GROUP:
          return "group";
      case OFPR_PACKET_OUT:
          return "packet_out";
  
      case OFPR_N_REASONS:
      default:
          snprintf(reasonbuf, bufsize, "%d", (int) reason);
          return reasonbuf;
      }
  }
  
  bool
  ofputil_packet_in_reason_from_string(const char *s,
                                       enum ofp_packet_in_reason *reason)
  {
      int i;
  
      for (i = 0; i < OFPR_N_REASONS; i++) {
          char reasonbuf[OFPUTIL_PACKET_IN_REASON_BUFSIZE];
          const char *reason_s;
  
          reason_s = ofputil_packet_in_reason_to_string(i, reasonbuf,
                                                        sizeof reasonbuf);
          if (!strcasecmp(s, reason_s)) {
              *reason = i;
              return true;
          }
      }
      return false;
  }
  
  /* Converts an OFPT_PACKET_OUT in 'opo' into an abstract ofputil_packet_out in
   * 'po'.
   *
   * Uses 'ofpacts' to store the abstract OFPACT_* version of the packet out
   * message's actions.  The caller must initialize 'ofpacts' and retains
   * ownership of it.  'po->ofpacts' will point into the 'ofpacts' buffer.
   *
   * Returns 0 if successful, otherwise an OFPERR_* value. */
  enum ofperr
  ofputil_decode_packet_out(struct ofputil_packet_out *po,
                            const struct ofp_header *oh,
                            struct ofpbuf *ofpacts)
  {
      enum ofpraw raw;
      struct ofpbuf b;
  
      ofpbuf_use_const(&b, oh, ntohs(oh->length));
      raw = ofpraw_pull_assert(&b);
  
      if (raw == OFPRAW_OFPT11_PACKET_OUT) {
          enum ofperr error;
          const struct ofp11_packet_out *opo = ofpbuf_pull(&b, sizeof *opo);
  
          po->buffer_id = ntohl(opo->buffer_id);
          error = ofputil_port_from_ofp11(opo->in_port, &po->in_port);
          if (error) {
              return error;
          }
  
          error = ofpacts_pull_openflow_actions(&b, ntohs(opo->actions_len),
                                                oh->version, ofpacts);
          if (error) {
              return error;
          }
      } else if (raw == OFPRAW_OFPT10_PACKET_OUT) {
          enum ofperr error;
          const struct ofp10_packet_out *opo = ofpbuf_pull(&b, sizeof *opo);
  
          po->buffer_id = ntohl(opo->buffer_id);
          po->in_port = u16_to_ofp(ntohs(opo->in_port));
  
          error = ofpacts_pull_openflow_actions(&b, ntohs(opo->actions_len),
                                                oh->version, ofpacts);
          if (error) {
              return error;
          }
      } else {
          OVS_NOT_REACHED();
      }
  
      if (ofp_to_u16(po->in_port) >= ofp_to_u16(OFPP_MAX)
          && po->in_port != OFPP_LOCAL
          && po->in_port != OFPP_NONE && po->in_port != OFPP_CONTROLLER) {
          VLOG_WARN_RL(&bad_ofmsg_rl, "packet-out has bad input port %#"PRIx16,
                       po->in_port);
          return OFPERR_OFPBRC_BAD_PORT;
      }
  
      po->ofpacts = ofpacts->data;
      po->ofpacts_len = ofpacts->size;
  
      if (po->buffer_id == UINT32_MAX) {
          po->packet = b.data;
          po->packet_len = b.size;
      } else {
          po->packet = NULL;
          po->packet_len = 0;
      }
  
      return 0;
  }
  
  /* ofputil_phy_port */
  
  /* NETDEV_F_* to and from OFPPF_* and OFPPF10_*. */
  BUILD_ASSERT_DECL((int) NETDEV_F_10MB_HD    == OFPPF_10MB_HD);  /* bit 0 */
  BUILD_ASSERT_DECL((int) NETDEV_F_10MB_FD    == OFPPF_10MB_FD);  /* bit 1 */
  BUILD_ASSERT_DECL((int) NETDEV_F_100MB_HD   == OFPPF_100MB_HD); /* bit 2 */
  BUILD_ASSERT_DECL((int) NETDEV_F_100MB_FD   == OFPPF_100MB_FD); /* bit 3 */
  BUILD_ASSERT_DECL((int) NETDEV_F_1GB_HD     == OFPPF_1GB_HD);   /* bit 4 */
  BUILD_ASSERT_DECL((int) NETDEV_F_1GB_FD     == OFPPF_1GB_FD);   /* bit 5 */
  BUILD_ASSERT_DECL((int) NETDEV_F_10GB_FD    == OFPPF_10GB_FD);  /* bit 6 */
  
  /* NETDEV_F_ bits 11...15 are OFPPF10_ bits 7...11: */
  BUILD_ASSERT_DECL((int) NETDEV_F_COPPER == (OFPPF10_COPPER << 4));
  BUILD_ASSERT_DECL((int) NETDEV_F_FIBER == (OFPPF10_FIBER << 4));
  BUILD_ASSERT_DECL((int) NETDEV_F_AUTONEG == (OFPPF10_AUTONEG << 4));
  BUILD_ASSERT_DECL((int) NETDEV_F_PAUSE == (OFPPF10_PAUSE << 4));
  BUILD_ASSERT_DECL((int) NETDEV_F_PAUSE_ASYM == (OFPPF10_PAUSE_ASYM << 4));
  
  static enum netdev_features
  netdev_port_features_from_ofp10(ovs_be32 ofp10_)
  {
      uint32_t ofp10 = ntohl(ofp10_);
      return (ofp10 & 0x7f) | ((ofp10 & 0xf80) << 4);
  }
  
  static ovs_be32
  netdev_port_features_to_ofp10(enum netdev_features features)
  {
      return htonl((features & 0x7f) | ((features & 0xf800) >> 4));
  }
  
  BUILD_ASSERT_DECL((int) NETDEV_F_10MB_HD    == OFPPF_10MB_HD);     /* bit 0 */
  BUILD_ASSERT_DECL((int) NETDEV_F_10MB_FD    == OFPPF_10MB_FD);     /* bit 1 */
  BUILD_ASSERT_DECL((int) NETDEV_F_100MB_HD   == OFPPF_100MB_HD);    /* bit 2 */
  BUILD_ASSERT_DECL((int) NETDEV_F_100MB_FD   == OFPPF_100MB_FD);    /* bit 3 */
  BUILD_ASSERT_DECL((int) NETDEV_F_1GB_HD     == OFPPF_1GB_HD);      /* bit 4 */
  BUILD_ASSERT_DECL((int) NETDEV_F_1GB_FD     == OFPPF_1GB_FD);      /* bit 5 */
  BUILD_ASSERT_DECL((int) NETDEV_F_10GB_FD    == OFPPF_10GB_FD);     /* bit 6 */
  BUILD_ASSERT_DECL((int) NETDEV_F_40GB_FD    == OFPPF11_40GB_FD);   /* bit 7 */
  BUILD_ASSERT_DECL((int) NETDEV_F_100GB_FD   == OFPPF11_100GB_FD);  /* bit 8 */
  BUILD_ASSERT_DECL((int) NETDEV_F_1TB_FD     == OFPPF11_1TB_FD);    /* bit 9 */
  BUILD_ASSERT_DECL((int) NETDEV_F_OTHER      == OFPPF11_OTHER);     /* bit 10 */
  BUILD_ASSERT_DECL((int) NETDEV_F_COPPER     == OFPPF11_COPPER);    /* bit 11 */
  BUILD_ASSERT_DECL((int) NETDEV_F_FIBER      == OFPPF11_FIBER);     /* bit 12 */
  BUILD_ASSERT_DECL((int) NETDEV_F_AUTONEG    == OFPPF11_AUTONEG);   /* bit 13 */
  BUILD_ASSERT_DECL((int) NETDEV_F_PAUSE      == OFPPF11_PAUSE);     /* bit 14 */
  BUILD_ASSERT_DECL((int) NETDEV_F_PAUSE_ASYM == OFPPF11_PAUSE_ASYM);/* bit 15 */
  
  static enum netdev_features
  netdev_port_features_from_ofp11(ovs_be32 ofp11)
  {
      return ntohl(ofp11) & 0xffff;
  }
  
  static ovs_be32
  netdev_port_features_to_ofp11(enum netdev_features features)
  {
      return htonl(features & 0xffff);
  }
  
  static enum ofperr
  ofputil_decode_ofp10_phy_port(struct ofputil_phy_port *pp,
                                const struct ofp10_phy_port *opp)
  {
      pp->port_no = u16_to_ofp(ntohs(opp->port_no));
      memcpy(pp->hw_addr, opp->hw_addr, OFP_ETH_ALEN);
      ovs_strlcpy(pp->name, opp->name, OFP_MAX_PORT_NAME_LEN);
  
      pp->config = ntohl(opp->config) & OFPPC10_ALL;
      pp->state = ntohl(opp->state) & OFPPS10_ALL;
  
      pp->curr = netdev_port_features_from_ofp10(opp->curr);
      pp->advertised = netdev_port_features_from_ofp10(opp->advertised);
      pp->supported = netdev_port_features_from_ofp10(opp->supported);
      pp->peer = netdev_port_features_from_ofp10(opp->peer);
  
      pp->curr_speed = netdev_features_to_bps(pp->curr, 0) / 1000;
      pp->max_speed = netdev_features_to_bps(pp->supported, 0) / 1000;
  
      return 0;
  }
  
  static enum ofperr
  ofputil_decode_ofp11_port(struct ofputil_phy_port *pp,
                            const struct ofp11_port *op)
  {
      enum ofperr error;
  
      error = ofputil_port_from_ofp11(op->port_no, &pp->port_no);
      if (error) {
          return error;
      }
      memcpy(pp->hw_addr, op->hw_addr, OFP_ETH_ALEN);
      ovs_strlcpy(pp->name, op->name, OFP_MAX_PORT_NAME_LEN);
  
      pp->config = ntohl(op->config) & OFPPC11_ALL;
      pp->state = ntohl(op->state) & OFPPS11_ALL;
  
      pp->curr = netdev_port_features_from_ofp11(op->curr);
      pp->advertised = netdev_port_features_from_ofp11(op->advertised);
      pp->supported = netdev_port_features_from_ofp11(op->supported);
      pp->peer = netdev_port_features_from_ofp11(op->peer);
  
      pp->curr_speed = ntohl(op->curr_speed);
      pp->max_speed = ntohl(op->max_speed);
  
      return 0;
  }
  
  static enum ofperr
  parse_ofp14_port_ethernet_property(const struct ofpbuf *payload,
                                     struct ofputil_phy_port *pp)
  {
      struct ofp14_port_desc_prop_ethernet *eth = payload->data;
  
      if (payload->size != sizeof *eth) {
          return OFPERR_OFPBPC_BAD_LEN;
      }
  
      pp->curr = netdev_port_features_from_ofp11(eth->curr);
      pp->advertised = netdev_port_features_from_ofp11(eth->advertised);
      pp->supported = netdev_port_features_from_ofp11(eth->supported);
      pp->peer = netdev_port_features_from_ofp11(eth->peer);
  
      pp->curr_speed = ntohl(eth->curr_speed);
      pp->max_speed = ntohl(eth->max_speed);
  
      return 0;
  }
  
  static enum ofperr
  ofputil_pull_ofp14_port(struct ofputil_phy_port *pp, struct ofpbuf *msg)
  {
      struct ofpbuf properties;
      struct ofp14_port *op;
      enum ofperr error;
      size_t len;
  
      op = ofpbuf_try_pull(msg, sizeof *op);
      if (!op) {
          return OFPERR_OFPBRC_BAD_LEN;
      }
  
      len = ntohs(op->length);
      if (len < sizeof *op || len - sizeof *op > msg->size) {
          return OFPERR_OFPBRC_BAD_LEN;
      }
      len -= sizeof *op;
      ofpbuf_use_const(&properties, ofpbuf_pull(msg, len), len);
  
      error = ofputil_port_from_ofp11(op->port_no, &pp->port_no);
      if (error) {
          return error;
      }
      memcpy(pp->hw_addr, op->hw_addr, OFP_ETH_ALEN);
      ovs_strlcpy(pp->name, op->name, OFP_MAX_PORT_NAME_LEN);
  
      pp->config = ntohl(op->config) & OFPPC11_ALL;
      pp->state = ntohl(op->state) & OFPPS11_ALL;
  
      while (properties.size > 0) {
          struct ofpbuf payload;
          enum ofperr error;
          uint16_t type;
  
          error = ofputil_pull_property(&properties, &payload, &type);
          if (error) {
              return error;
          }
  
          switch (type) {
          case OFPPDPT14_ETHERNET:
              error = parse_ofp14_port_ethernet_property(&payload, pp);
              break;
  
          default:
              log_property(true, "unknown port property %"PRIu16, type);
              error = 0;
              break;
          }
  
          if (error) {
              return error;
          }
      }
  
      return 0;
  }
  
  static void
  ofputil_encode_ofp10_phy_port(const struct ofputil_phy_port *pp,
                                struct ofp10_phy_port *opp)
  {
      memset(opp, 0, sizeof *opp);
  
      opp->port_no = htons(ofp_to_u16(pp->port_no));
      memcpy(opp->hw_addr, pp->hw_addr, ETH_ADDR_LEN);
      ovs_strlcpy(opp->name, pp->name, OFP_MAX_PORT_NAME_LEN);
  
      opp->config = htonl(pp->config & OFPPC10_ALL);
      opp->state = htonl(pp->state & OFPPS10_ALL);
  
      opp->curr = netdev_port_features_to_ofp10(pp->curr);
      opp->advertised = netdev_port_features_to_ofp10(pp->advertised);
      opp->supported = netdev_port_features_to_ofp10(pp->supported);
      opp->peer = netdev_port_features_to_ofp10(pp->peer);
  }
  
  static void
  ofputil_encode_ofp11_port(const struct ofputil_phy_port *pp,
                            struct ofp11_port *op)
  {
      memset(op, 0, sizeof *op);
  
      op->port_no = ofputil_port_to_ofp11(pp->port_no);
      memcpy(op->hw_addr, pp->hw_addr, ETH_ADDR_LEN);
      ovs_strlcpy(op->name, pp->name, OFP_MAX_PORT_NAME_LEN);
  
      op->config = htonl(pp->config & OFPPC11_ALL);
      op->state = htonl(pp->state & OFPPS11_ALL);
  
      op->curr = netdev_port_features_to_ofp11(pp->curr);
      op->advertised = netdev_port_features_to_ofp11(pp->advertised);
      op->supported = netdev_port_features_to_ofp11(pp->supported);
      op->peer = netdev_port_features_to_ofp11(pp->peer);
  
      op->curr_speed = htonl(pp->curr_speed);
      op->max_speed = htonl(pp->max_speed);
  }
  
  static void
  ofputil_put_ofp14_port(const struct ofputil_phy_port *pp,
                         struct ofpbuf *b)
  {
      struct ofp14_port *op;
      struct ofp14_port_desc_prop_ethernet *eth;
  
      ofpbuf_prealloc_tailroom(b, sizeof *op + sizeof *eth);
  
      op = ofpbuf_put_zeros(b, sizeof *op);
      op->port_no = ofputil_port_to_ofp11(pp->port_no);
      op->length = htons(sizeof *op + sizeof *eth);
      memcpy(op->hw_addr, pp->hw_addr, ETH_ADDR_LEN);
      ovs_strlcpy(op->name, pp->name, sizeof op->name);
      op->config = htonl(pp->config & OFPPC11_ALL);
      op->state = htonl(pp->state & OFPPS11_ALL);
  
      eth = ofpbuf_put_zeros(b, sizeof *eth);
      eth->type = htons(OFPPDPT14_ETHERNET);
      eth->length = htons(sizeof *eth);
      eth->curr = netdev_port_features_to_ofp11(pp->curr);
      eth->advertised = netdev_port_features_to_ofp11(pp->advertised);
      eth->supported = netdev_port_features_to_ofp11(pp->supported);
      eth->peer = netdev_port_features_to_ofp11(pp->peer);
      eth->curr_speed = htonl(pp->curr_speed);
      eth->max_speed = htonl(pp->max_speed);
  }
  
  static void
  ofputil_put_phy_port(enum ofp_version ofp_version,
                       const struct ofputil_phy_port *pp, struct ofpbuf *b)
  {
      switch (ofp_version) {
      case OFP10_VERSION: {
          struct ofp10_phy_port *opp = ofpbuf_put_uninit(b, sizeof *opp);
          ofputil_encode_ofp10_phy_port(pp, opp);
          break;
      }
  
      case OFP11_VERSION:
      case OFP12_VERSION:
      case OFP13_VERSION: {
          struct ofp11_port *op = ofpbuf_put_uninit(b, sizeof *op);
          ofputil_encode_ofp11_port(pp, op);
          break;
      }
  
      case OFP14_VERSION:
      case OFP15_VERSION:
          ofputil_put_ofp14_port(pp, b);
          break;
  
      default:
          OVS_NOT_REACHED();
      }
  }
  
  enum ofperr
  ofputil_decode_port_desc_stats_request(const struct ofp_header *request,
                                         ofp_port_t *port)
  {
      struct ofpbuf b;
      enum ofpraw raw;
  
      ofpbuf_use_const(&b, request, ntohs(request->length));
      raw = ofpraw_pull_assert(&b);
      if (raw == OFPRAW_OFPST10_PORT_DESC_REQUEST) {
          *port = OFPP_ANY;
          return 0;
      } else if (raw == OFPRAW_OFPST15_PORT_DESC_REQUEST) {
          ovs_be32 *ofp11_port;
  
          ofp11_port = ofpbuf_pull(&b, sizeof *ofp11_port);
          return ofputil_port_from_ofp11(*ofp11_port, port);
      } else {
          OVS_NOT_REACHED();
      }
  }
  
  struct ofpbuf *
  ofputil_encode_port_desc_stats_request(enum ofp_version ofp_version,
                                         ofp_port_t port)
  {
      struct ofpbuf *request;
      ovs_be32 ofp11_port;
  
      switch (ofp_version) {
      case OFP10_VERSION:
      case OFP11_VERSION:
      case OFP12_VERSION:
      case OFP13_VERSION:
      case OFP14_VERSION:
          request = ofpraw_alloc(OFPRAW_OFPST10_PORT_DESC_REQUEST,
                                 ofp_version, 0);
          break;
  
      case OFP15_VERSION:
          request = ofpraw_alloc(OFPRAW_OFPST15_PORT_DESC_REQUEST,
                                 ofp_version, 0);
          ofp11_port = ofputil_port_to_ofp11(port);
          ofpbuf_put(request, &ofp11_port, sizeof ofp11_port);
          break;
  
      default:
          OVS_NOT_REACHED();
      }
  
      return request;
  }
  
  void
  ofputil_append_port_desc_stats_reply(const struct ofputil_phy_port *pp,
                                       struct ovs_list *replies)
  {
      struct ofpbuf *reply = ofpbuf_from_list(list_back(replies));
      size_t start_ofs = reply->size;
  
      ofputil_put_phy_port(ofpmp_version(replies), pp, reply);
      ofpmp_postappend(replies, start_ofs);
  }
  
  /* ofputil_switch_features */
  
  #define OFPC_COMMON (OFPC_FLOW_STATS | OFPC_TABLE_STATS | OFPC_PORT_STATS | \
                       OFPC_IP_REASM | OFPC_QUEUE_STATS)
  BUILD_ASSERT_DECL((int) OFPUTIL_C_FLOW_STATS == OFPC_FLOW_STATS);
  BUILD_ASSERT_DECL((int) OFPUTIL_C_TABLE_STATS == OFPC_TABLE_STATS);
  BUILD_ASSERT_DECL((int) OFPUTIL_C_PORT_STATS == OFPC_PORT_STATS);
  BUILD_ASSERT_DECL((int) OFPUTIL_C_IP_REASM == OFPC_IP_REASM);
  BUILD_ASSERT_DECL((int) OFPUTIL_C_QUEUE_STATS == OFPC_QUEUE_STATS);
  BUILD_ASSERT_DECL((int) OFPUTIL_C_ARP_MATCH_IP == OFPC_ARP_MATCH_IP);
  
  static uint32_t
  ofputil_capabilities_mask(enum ofp_version ofp_version)
  {
      /* Handle capabilities whose bit is unique for all OpenFlow versions */
      switch (ofp_version) {
      case OFP10_VERSION:
      case OFP11_VERSION:
          return OFPC_COMMON | OFPC_ARP_MATCH_IP;
      case OFP12_VERSION:
      case OFP13_VERSION:
      case OFP14_VERSION:
      case OFP15_VERSION:
          return OFPC_COMMON | OFPC12_PORT_BLOCKED;
      default:
          /* Caller needs to check osf->header.version itself */
          return 0;
      }
  }
  
  /* Decodes an OpenFlow 1.0 or 1.1 "switch_features" structure 'osf' into an
   * abstract representation in '*features'.  Initializes '*b' to iterate over
   * the OpenFlow port structures following 'osf' with later calls to
   * ofputil_pull_phy_port().  Returns 0 if successful, otherwise an
   * OFPERR_* value.  */
  enum ofperr
  ofputil_decode_switch_features(const struct ofp_header *oh,
                                 struct ofputil_switch_features *features,
                                 struct ofpbuf *b)
  {
      const struct ofp_switch_features *osf;
      enum ofpraw raw;
  
      ofpbuf_use_const(b, oh, ntohs(oh->length));
      raw = ofpraw_pull_assert(b);
  
      osf = ofpbuf_pull(b, sizeof *osf);
      features->datapath_id = ntohll(osf->datapath_id);
      features->n_buffers = ntohl(osf->n_buffers);
      features->n_tables = osf->n_tables;
      features->auxiliary_id = 0;
  
      features->capabilities = ntohl(osf->capabilities) &
          ofputil_capabilities_mask(oh->version);
  
      if (raw == OFPRAW_OFPT10_FEATURES_REPLY) {
          if (osf->capabilities & htonl(OFPC10_STP)) {
              features->capabilities |= OFPUTIL_C_STP;
          }
          features->ofpacts = ofpact_bitmap_from_openflow(osf->actions,
                                                          OFP10_VERSION);
      } else if (raw == OFPRAW_OFPT11_FEATURES_REPLY
                 || raw == OFPRAW_OFPT13_FEATURES_REPLY) {
          if (osf->capabilities & htonl(OFPC11_GROUP_STATS)) {
              features->capabilities |= OFPUTIL_C_GROUP_STATS;
          }
          features->ofpacts = 0;
          if (raw == OFPRAW_OFPT13_FEATURES_REPLY) {
              features->auxiliary_id = osf->auxiliary_id;
          }
      } else {
          return OFPERR_OFPBRC_BAD_VERSION;
      }
  
      return 0;
  }
  
  /* In OpenFlow 1.0, 1.1, and 1.2, an OFPT_FEATURES_REPLY message lists all the
   * switch's ports, unless there are too many to fit.  In OpenFlow 1.3 and
   * later, an OFPT_FEATURES_REPLY does not list ports at all.
   *
   * Given a buffer 'b' that contains a Features Reply message, this message
   * checks if it contains a complete list of the switch's ports.  Returns true,
   * if so.  Returns false if the list is missing (OF1.3+) or incomplete
   * (OF1.0/1.1/1.2), and in the latter case removes all of the ports from the
   * message.
   *
   * When this function returns false, the caller should send an OFPST_PORT_DESC
   * stats request to get the ports. */
  bool
  ofputil_switch_features_has_ports(struct ofpbuf *b)
  {
      struct ofp_header *oh = b->data;
      size_t phy_port_size;
  
      if (oh->version >= OFP13_VERSION) {
          /* OpenFlow 1.3+ never has ports in the feature reply. */
          return false;
      }
  
      phy_port_size = (oh->version == OFP10_VERSION
                       ? sizeof(struct ofp10_phy_port)
                       : sizeof(struct ofp11_port));
      if (ntohs(oh->length) + phy_port_size <= UINT16_MAX) {
          /* There's room for additional ports in the feature reply.
           * Assume that the list is complete. */
          return true;
      }
  
      /* The feature reply has no room for more ports.  Probably the list is
       * truncated.  Drop the ports and tell the caller to retrieve them with
       * OFPST_PORT_DESC. */
      b->size = sizeof *oh + sizeof(struct ofp_switch_features);
      ofpmsg_update_length(b);
      return false;
  }
  
  /* Returns a buffer owned by the caller that encodes 'features' in the format
   * required by 'protocol' with the given 'xid'.  The caller should append port
   * information to the buffer with subsequent calls to
   * ofputil_put_switch_features_port(). */
  struct ofpbuf *
  ofputil_encode_switch_features(const struct ofputil_switch_features *features,
                                 enum ofputil_protocol protocol, ovs_be32 xid)
  {
      struct ofp_switch_features *osf;
      struct ofpbuf *b;
      enum ofp_version version;
      enum ofpraw raw;
  
      version = ofputil_protocol_to_ofp_version(protocol);
      switch (version) {
      case OFP10_VERSION:
          raw = OFPRAW_OFPT10_FEATURES_REPLY;
          break;
      case OFP11_VERSION:
      case OFP12_VERSION:
          raw = OFPRAW_OFPT11_FEATURES_REPLY;
          break;
      case OFP13_VERSION:
      case OFP14_VERSION:
      case OFP15_VERSION:
          raw = OFPRAW_OFPT13_FEATURES_REPLY;
          break;
      default:
          OVS_NOT_REACHED();
      }
      b = ofpraw_alloc_xid(raw, version, xid, 0);
      osf = ofpbuf_put_zeros(b, sizeof *osf);
      osf->datapath_id = htonll(features->datapath_id);
      osf->n_buffers = htonl(features->n_buffers);
      osf->n_tables = features->n_tables;
  
      osf->capabilities = htonl(features->capabilities & OFPC_COMMON);
      osf->capabilities = htonl(features->capabilities &
                                ofputil_capabilities_mask(version));
      switch (version) {
      case OFP10_VERSION:
          if (features->capabilities & OFPUTIL_C_STP) {
              osf->capabilities |= htonl(OFPC10_STP);
          }
          osf->actions = ofpact_bitmap_to_openflow(features->ofpacts,
                                                   OFP10_VERSION);
          break;
      case OFP13_VERSION:
      case OFP14_VERSION:
      case OFP15_VERSION:
          osf->auxiliary_id = features->auxiliary_id;
          /* fall through */
      case OFP11_VERSION:
      case OFP12_VERSION:
          if (features->capabilities & OFPUTIL_C_GROUP_STATS) {
              osf->capabilities |= htonl(OFPC11_GROUP_STATS);
          }
          break;
      default:
          OVS_NOT_REACHED();
      }
  
      return b;
  }
  
  /* Encodes 'pp' into the format required by the switch_features message already
   * in 'b', which should have been returned by ofputil_encode_switch_features(),
   * and appends the encoded version to 'b'. */
  void
  ofputil_put_switch_features_port(const struct ofputil_phy_port *pp,
                                   struct ofpbuf *b)
  {
      const struct ofp_header *oh = b->data;
  
      if (oh->version < OFP13_VERSION) {
          /* Try adding a port description to the message, but drop it again if
           * the buffer overflows.  (This possibility for overflow is why
           * OpenFlow 1.3+ moved port descriptions into a multipart message.)  */
          size_t start_ofs = b->size;
          ofputil_put_phy_port(oh->version, pp, b);
          if (b->size > UINT16_MAX) {
              b->size = start_ofs;
          }
      }
  }
  
  /* ofputil_port_status */
  
  /* Decodes the OpenFlow "port status" message in '*ops' into an abstract form
   * in '*ps'.  Returns 0 if successful, otherwise an OFPERR_* value. */
  enum ofperr
  ofputil_decode_port_status(const struct ofp_header *oh,
                             struct ofputil_port_status *ps)
  {
      const struct ofp_port_status *ops;
      struct ofpbuf b;
      int retval;
  
      ofpbuf_use_const(&b, oh, ntohs(oh->length));
      ofpraw_pull_assert(&b);
      ops = ofpbuf_pull(&b, sizeof *ops);
  
      if (ops->reason != OFPPR_ADD &&
          ops->reason != OFPPR_DELETE &&
          ops->reason != OFPPR_MODIFY) {
          return OFPERR_NXBRC_BAD_REASON;
      }
      ps->reason = ops->reason;
  
      retval = ofputil_pull_phy_port(oh->version, &b, &ps->desc);
      ovs_assert(retval != EOF);
      return retval;
  }
  
  /* Converts the abstract form of a "port status" message in '*ps' into an
   * OpenFlow message suitable for 'protocol', and returns that encoded form in
   * a buffer owned by the caller. */
  struct ofpbuf *
  ofputil_encode_port_status(const struct ofputil_port_status *ps,
                             enum ofputil_protocol protocol)
  {
      struct ofp_port_status *ops;
      struct ofpbuf *b;
      enum ofp_version version;
      enum ofpraw raw;
  
      version = ofputil_protocol_to_ofp_version(protocol);
      switch (version) {
      case OFP10_VERSION:
          raw = OFPRAW_OFPT10_PORT_STATUS;
          break;
  
      case OFP11_VERSION:
      case OFP12_VERSION:
      case OFP13_VERSION:
          raw = OFPRAW_OFPT11_PORT_STATUS;
          break;
  
      case OFP14_VERSION:
      case OFP15_VERSION:
          raw = OFPRAW_OFPT14_PORT_STATUS;
          break;
  
      default:
          OVS_NOT_REACHED();
      }
  
      b = ofpraw_alloc_xid(raw, version, htonl(0), 0);
      ops = ofpbuf_put_zeros(b, sizeof *ops);
      ops->reason = ps->reason;
      ofputil_put_phy_port(version, &ps->desc, b);
      ofpmsg_update_length(b);
      return b;
  }
  
  /* ofputil_port_mod */
  
  static enum ofperr
  parse_port_mod_ethernet_property(struct ofpbuf *property,
                                   struct ofputil_port_mod *pm)
  {
      struct ofp14_port_mod_prop_ethernet *eth = property->data;
  
      if (property->size != sizeof *eth) {
          return OFPERR_OFPBRC_BAD_LEN;
      }
  
      pm->advertise = netdev_port_features_from_ofp11(eth->advertise);
      return 0;
  }
  
  /* Decodes the OpenFlow "port mod" message in '*oh' into an abstract form in
   * '*pm'.  Returns 0 if successful, otherwise an OFPERR_* value. */
  enum ofperr
  ofputil_decode_port_mod(const struct ofp_header *oh,
                          struct ofputil_port_mod *pm, bool loose)
  {
      enum ofpraw raw;
      struct ofpbuf b;
  
      ofpbuf_use_const(&b, oh, ntohs(oh->length));
      raw = ofpraw_pull_assert(&b);
  
      if (raw == OFPRAW_OFPT10_PORT_MOD) {
          const struct ofp10_port_mod *opm = b.data;
  
          pm->port_no = u16_to_ofp(ntohs(opm->port_no));
          memcpy(pm->hw_addr, opm->hw_addr, ETH_ADDR_LEN);
          pm->config = ntohl(opm->config) & OFPPC10_ALL;
          pm->mask = ntohl(opm->mask) & OFPPC10_ALL;
          pm->advertise = netdev_port_features_from_ofp10(opm->advertise);
      } else if (raw == OFPRAW_OFPT11_PORT_MOD) {
          const struct ofp11_port_mod *opm = b.data;
          enum ofperr error;
  
          error = ofputil_port_from_ofp11(opm->port_no, &pm->port_no);
          if (error) {
              return error;
          }
  
          memcpy(pm->hw_addr, opm->hw_addr, ETH_ADDR_LEN);
          pm->config = ntohl(opm->config) & OFPPC11_ALL;
          pm->mask = ntohl(opm->mask) & OFPPC11_ALL;
          pm->advertise = netdev_port_features_from_ofp11(opm->advertise);
      } else if (raw == OFPRAW_OFPT14_PORT_MOD) {
          const struct ofp14_port_mod *opm = ofpbuf_pull(&b, sizeof *opm);
          enum ofperr error;
  
          memset(pm, 0, sizeof *pm);
  
          error = ofputil_port_from_ofp11(opm->port_no, &pm->port_no);
          if (error) {
              return error;
          }
  
          memcpy(pm->hw_addr, opm->hw_addr, ETH_ADDR_LEN);
          pm->config = ntohl(opm->config) & OFPPC11_ALL;
          pm->mask = ntohl(opm->mask) & OFPPC11_ALL;
  
          while (b.size > 0) {
              struct ofpbuf property;
              enum ofperr error;
              uint16_t type;
  
              error = ofputil_pull_property(&b, &property, &type);
              if (error) {
                  return error;
              }
  
              switch (type) {
              case OFPPMPT14_ETHERNET:
                  error = parse_port_mod_ethernet_property(&property, pm);
                  break;
  
              default:
                  log_property(loose, "unknown port_mod property %"PRIu16, type);
                  if (loose) {
                      error = 0;
                  } else if (type == OFPPMPT14_EXPERIMENTER) {
                      error = OFPERR_OFPBPC_BAD_EXPERIMENTER;
                  } else {
                      error = OFPERR_OFPBRC_BAD_TYPE;
                  }
                  break;
              }
  
              if (error) {
                  return error;
              }
          }
      } else {
          return OFPERR_OFPBRC_BAD_TYPE;
      }
  
      pm->config &= pm->mask;
      return 0;
  }
  
  /* Converts the abstract form of a "port mod" message in '*pm' into an OpenFlow
   * message suitable for 'protocol', and returns that encoded form in a buffer
   * owned by the caller. */
  struct ofpbuf *
  ofputil_encode_port_mod(const struct ofputil_port_mod *pm,
                          enum ofputil_protocol protocol)
  {
      enum ofp_version ofp_version = ofputil_protocol_to_ofp_version(protocol);
      struct ofpbuf *b;
  
      switch (ofp_version) {
      case OFP10_VERSION: {
          struct ofp10_port_mod *opm;
  
          b = ofpraw_alloc(OFPRAW_OFPT10_PORT_MOD, ofp_version, 0);
          opm = ofpbuf_put_zeros(b, sizeof *opm);
          opm->port_no = htons(ofp_to_u16(pm->port_no));
          memcpy(opm->hw_addr, pm->hw_addr, ETH_ADDR_LEN);
          opm->config = htonl(pm->config & OFPPC10_ALL);
          opm->mask = htonl(pm->mask & OFPPC10_ALL);
          opm->advertise = netdev_port_features_to_ofp10(pm->advertise);
          break;
      }
  
      case OFP11_VERSION:
      case OFP12_VERSION:
      case OFP13_VERSION: {
          struct ofp11_port_mod *opm;
  
          b = ofpraw_alloc(OFPRAW_OFPT11_PORT_MOD, ofp_version, 0);
          opm = ofpbuf_put_zeros(b, sizeof *opm);
          opm->port_no = ofputil_port_to_ofp11(pm->port_no);
          memcpy(opm->hw_addr, pm->hw_addr, ETH_ADDR_LEN);
          opm->config = htonl(pm->config & OFPPC11_ALL);
          opm->mask = htonl(pm->mask & OFPPC11_ALL);
          opm->advertise = netdev_port_features_to_ofp11(pm->advertise);
          break;
      }
      case OFP14_VERSION:
      case OFP15_VERSION: {
          struct ofp14_port_mod_prop_ethernet *eth;
          struct ofp14_port_mod *opm;
  
          b = ofpraw_alloc(OFPRAW_OFPT14_PORT_MOD, ofp_version, sizeof *eth);
          opm = ofpbuf_put_zeros(b, sizeof *opm);
          opm->port_no = ofputil_port_to_ofp11(pm->port_no);
          memcpy(opm->hw_addr, pm->hw_addr, ETH_ADDR_LEN);
          opm->config = htonl(pm->config & OFPPC11_ALL);
          opm->mask = htonl(pm->mask & OFPPC11_ALL);
  
          if (pm->advertise) {
              eth = ofpbuf_put_zeros(b, sizeof *eth);
              eth->type = htons(OFPPMPT14_ETHERNET);
              eth->length = htons(sizeof *eth);
              eth->advertise = netdev_port_features_to_ofp11(pm->advertise);
          }
          break;
      }
      default:
          OVS_NOT_REACHED();
      }
  
      return b;
  }
  
  /* Table features. */
  
  static enum ofperr
  pull_table_feature_property(struct ofpbuf *msg, struct ofpbuf *payload,
                              uint16_t *typep)
  {
      enum ofperr error;
  
      error = ofputil_pull_property(msg, payload, typep);
      if (payload && !error) {
          ofpbuf_pull(payload, sizeof(struct ofp_prop_header));
      }
      return error;
  }
  
  static enum ofperr
  parse_action_bitmap(struct ofpbuf *payload, enum ofp_version ofp_version,
                      uint64_t *ofpacts)
  {
      uint32_t types = 0;
  
      while (payload->size > 0) {
          uint16_t type;
          enum ofperr error;
  
          error = ofputil_pull_property__(payload, NULL, 1, &type);
          if (error) {
              return error;
          }
          if (type < CHAR_BIT * sizeof types) {
              types |= 1u << type;
          }
      }
  
      *ofpacts = ofpact_bitmap_from_openflow(htonl(types), ofp_version);
      return 0;
  }
  
  static enum ofperr
  parse_instruction_ids(struct ofpbuf *payload, bool loose, uint32_t *insts)
  {
      *insts = 0;
      while (payload->size > 0) {
          enum ovs_instruction_type inst;
          enum ofperr error;
          uint16_t ofpit;
  
          /* OF1.3 and OF1.4 aren't clear about padding in the instruction IDs.
           * It seems clear that they aren't padded to 8 bytes, though, because
           * both standards say that "non-experimenter instructions are 4 bytes"
           * and do not mention any padding before the first instruction ID.
           * (There wouldn't be any point in padding to 8 bytes if the IDs were
           * aligned on an odd 4-byte boundary.)
           *
           * Anyway, we just assume they're all glommed together on byte
           * boundaries. */
          error = ofputil_pull_property__(payload, NULL, 1, &ofpit);
          if (error) {
              return error;
          }
  
          error = ovs_instruction_type_from_inst_type(&inst, ofpit);
          if (!error) {
              *insts |= 1u << inst;
          } else if (!loose) {
              return error;
          }
      }
      return 0;
  }
  
  static enum ofperr
  parse_table_features_next_table(struct ofpbuf *payload,
                                  unsigned long int *next_tables)
  {
      size_t i;
  
      memset(next_tables, 0, bitmap_n_bytes(255));
      for (i = 0; i < payload->size; i++) {
          uint8_t id = ((const uint8_t *) payload->data)[i];
          if (id >= 255) {
              return OFPERR_OFPBPC_BAD_VALUE;
          }
          bitmap_set1(next_tables, id);
      }
      return 0;
  }
  
  static enum ofperr
  parse_oxms(struct ofpbuf *payload, bool loose,
             struct mf_bitmap *exactp, struct mf_bitmap *maskedp)
  {
      struct mf_bitmap exact = MF_BITMAP_INITIALIZER;
      struct mf_bitmap masked = MF_BITMAP_INITIALIZER;
  
      while (payload->size > 0) {
          const struct mf_field *field;
          enum ofperr error;
          bool hasmask;
  
          error = nx_pull_header(payload, &field, &hasmask);
          if (!error) {
              bitmap_set1(hasmask ? masked.bm : exact.bm, field->id);
          } else if (error != OFPERR_OFPBMC_BAD_FIELD || !loose) {
              return error;
          }
      }
      if (exactp) {
          *exactp = exact;
      } else if (!bitmap_is_all_zeros(exact.bm, MFF_N_IDS)) {
          return OFPERR_OFPBMC_BAD_MASK;
      }
      if (maskedp) {
          *maskedp = masked;
      } else if (!bitmap_is_all_zeros(masked.bm, MFF_N_IDS)) {
          return OFPERR_OFPBMC_BAD_MASK;
      }
      return 0;
  }
  
  /* Converts an OFPMP_TABLE_FEATURES request or reply in 'msg' into an abstract
   * ofputil_table_features in 'tf'.
   *
   * If 'loose' is true, this function ignores properties and values that it does
   * not understand, as a controller would want to do when interpreting
   * capabilities provided by a switch.  If 'loose' is false, this function
   * treats unknown properties and values as an error, as a switch would want to
   * do when interpreting a configuration request made by a controller.
   *
   * A single OpenFlow message can specify features for multiple tables.  Calling
   * this function multiple times for a single 'msg' iterates through the tables
   * in the message.  The caller must initially leave 'msg''s layer pointers null
   * and not modify them between calls.
   *
   * Returns 0 if successful, EOF if no tables were left in this 'msg', otherwise
   * a positive "enum ofperr" value. */
  int
  ofputil_decode_table_features(struct ofpbuf *msg,
                                struct ofputil_table_features *tf, bool loose)
  {
      const struct ofp_header *oh;
      struct ofp13_table_features *otf;
      struct ofpbuf properties;
      unsigned int len;
  
      memset(tf, 0, sizeof *tf);
  
      if (!msg->header) {
          ofpraw_pull_assert(msg);
      }
      oh = msg->header;
  
      if (!msg->size) {
          return EOF;
      }
  
      if (msg->size < sizeof *otf) {
          return OFPERR_OFPBPC_BAD_LEN;
      }
  
      otf = msg->data;
      len = ntohs(otf->length);
      if (len < sizeof *otf || len % 8 || len > msg->size) {
          return OFPERR_OFPBPC_BAD_LEN;
      }
      ofpbuf_use_const(&properties, ofpbuf_pull(msg, len), len);
      ofpbuf_pull(&properties, sizeof *otf);
  
      tf->table_id = otf->table_id;
      if (tf->table_id == OFPTT_ALL) {
          return OFPERR_OFPTFFC_BAD_TABLE;
      }
  
      ovs_strlcpy(tf->name, otf->name, OFP_MAX_TABLE_NAME_LEN);
      tf->metadata_match = otf->metadata_match;
      tf->metadata_write = otf->metadata_write;
      tf->miss_config = OFPUTIL_TABLE_MISS_DEFAULT;
      if (oh->version >= OFP14_VERSION) {
          uint32_t caps = ntohl(otf->capabilities);
          tf->supports_eviction = (caps & OFPTC14_EVICTION) != 0;
          tf->supports_vacancy_events = (caps & OFPTC14_VACANCY_EVENTS) != 0;
      } else {
          tf->supports_eviction = -1;
          tf->supports_vacancy_events = -1;
      }
      tf->max_entries = ntohl(otf->max_entries);
  
      while (properties.size > 0) {
          struct ofpbuf payload;
          enum ofperr error;
          uint16_t type;
  
          error = pull_table_feature_property(&properties, &payload, &type);
          if (error) {
              return error;
          }
  
          switch ((enum ofp13_table_feature_prop_type) type) {
          case OFPTFPT13_INSTRUCTIONS:
              error = parse_instruction_ids(&payload, loose,
                                            &tf->nonmiss.instructions);
              break;
          case OFPTFPT13_INSTRUCTIONS_MISS:
              error = parse_instruction_ids(&payload, loose,
                                            &tf->miss.instructions);
              break;
  
          case OFPTFPT13_NEXT_TABLES:
              error = parse_table_features_next_table(&payload,
                                                      tf->nonmiss.next);
              break;
          case OFPTFPT13_NEXT_TABLES_MISS:
              error = parse_table_features_next_table(&payload, tf->miss.next);
              break;
  
          case OFPTFPT13_WRITE_ACTIONS:
              error = parse_action_bitmap(&payload, oh->version,
                                          &tf->nonmiss.write.ofpacts);
              break;
          case OFPTFPT13_WRITE_ACTIONS_MISS:
              error = parse_action_bitmap(&payload, oh->version,
                                          &tf->miss.write.ofpacts);
              break;
  
          case OFPTFPT13_APPLY_ACTIONS:
              error = parse_action_bitmap(&payload, oh->version,
                                          &tf->nonmiss.apply.ofpacts);
              break;
          case OFPTFPT13_APPLY_ACTIONS_MISS:
              error = parse_action_bitmap(&payload, oh->version,
                                          &tf->miss.apply.ofpacts);
              break;
  
          case OFPTFPT13_MATCH:
              error = parse_oxms(&payload, loose, &tf->match, &tf->mask);
              break;
          case OFPTFPT13_WILDCARDS:
              error = parse_oxms(&payload, loose, &tf->wildcard, NULL);
              break;
  
          case OFPTFPT13_WRITE_SETFIELD:
              error = parse_oxms(&payload, loose,
                                 &tf->nonmiss.write.set_fields, NULL);
              break;
          case OFPTFPT13_WRITE_SETFIELD_MISS:
              error = parse_oxms(&payload, loose,
                                 &tf->miss.write.set_fields, NULL);
              break;
          case OFPTFPT13_APPLY_SETFIELD:
              error = parse_oxms(&payload, loose,
                                 &tf->nonmiss.apply.set_fields, NULL);
              break;
          case OFPTFPT13_APPLY_SETFIELD_MISS:
              error = parse_oxms(&payload, loose,
                                 &tf->miss.apply.set_fields, NULL);
              break;
  
          case OFPTFPT13_EXPERIMENTER:
          case OFPTFPT13_EXPERIMENTER_MISS:
          default:
              log_property(loose, "unknown table features property %"PRIu16,
                           type);
              error = loose ? 0 : OFPERR_OFPBPC_BAD_TYPE;
              break;
          }
          if (error) {
              return error;
          }
      }
  
      /* Fix inconsistencies:
       *
       *     - Turn on 'match' bits that are set in 'mask', because maskable
       *       fields are matchable.
       *
       *     - Turn on 'wildcard' bits that are set in 'mask', because a field
       *       that is arbitrarily maskable can be wildcarded entirely.
       *
       *     - Turn off 'wildcard' bits that are not in 'match', because a field
       *       must be matchable for it to be meaningfully wildcarded. */
      bitmap_or(tf->match.bm, tf->mask.bm, MFF_N_IDS);
      bitmap_or(tf->wildcard.bm, tf->mask.bm, MFF_N_IDS);
      bitmap_and(tf->wildcard.bm, tf->match.bm, MFF_N_IDS);
  
      return 0;
  }
  
  /* Encodes and returns a request to obtain the table features of a switch.
   * The message is encoded for OpenFlow version 'ofp_version'. */
  struct ofpbuf *
  ofputil_encode_table_features_request(enum ofp_version ofp_version)
  {
      struct ofpbuf *request = NULL;
  
      switch (ofp_version) {
      case OFP10_VERSION:
      case OFP11_VERSION:
      case OFP12_VERSION:
          ovs_fatal(0, "dump-table-features needs OpenFlow 1.3 or later "
                       "(\'-O OpenFlow13\')");
      case OFP13_VERSION:
      case OFP14_VERSION:
      case OFP15_VERSION:
          request = ofpraw_alloc(OFPRAW_OFPST13_TABLE_FEATURES_REQUEST,
                                 ofp_version, 0);
          break;
      default:
          OVS_NOT_REACHED();
      }
  
      return request;
  }
  
  static void
  put_fields_property(struct ofpbuf *reply,
                      const struct mf_bitmap *fields,
                      const struct mf_bitmap *masks,
                      enum ofp13_table_feature_prop_type property,
                      enum ofp_version version)
  {
      size_t start_ofs;
      int field;
  
      start_ofs = start_property(reply, property);
      BITMAP_FOR_EACH_1 (field, MFF_N_IDS, fields->bm) {
          nx_put_header(reply, field, version,
                        masks && bitmap_is_set(masks->bm, field));
      }
      end_property(reply, start_ofs);
  }
  
  static void
  put_table_action_features(struct ofpbuf *reply,
                            const struct ofputil_table_action_features *taf,
                            enum ofp13_table_feature_prop_type actions_type,
                            enum ofp13_table_feature_prop_type set_fields_type,
                            int miss_offset, enum ofp_version version)
  {
      size_t start_ofs;
  
      start_ofs = start_property(reply, actions_type + miss_offset);
      put_bitmap_properties(reply,
                            ntohl(ofpact_bitmap_to_openflow(taf->ofpacts,
                                                            version)));
      end_property(reply, start_ofs);
  
      put_fields_property(reply, &taf->set_fields, NULL,
                          set_fields_type + miss_offset, version);
  }
  
  static void
  put_table_instruction_features(
      struct ofpbuf *reply, const struct ofputil_table_instruction_features *tif,
      int miss_offset, enum ofp_version version)
  {
      size_t start_ofs;
      uint8_t table_id;
  
      start_ofs = start_property(reply, OFPTFPT13_INSTRUCTIONS + miss_offset);
      put_bitmap_properties(reply,
                            ntohl(ovsinst_bitmap_to_openflow(tif->instructions,
                                                             version)));
      end_property(reply, start_ofs);
  
      start_ofs = start_property(reply, OFPTFPT13_NEXT_TABLES + miss_offset);
      BITMAP_FOR_EACH_1 (table_id, 255, tif->next) {
          ofpbuf_put(reply, &table_id, 1);
      }
      end_property(reply, start_ofs);
  
      put_table_action_features(reply, &tif->write,
                                OFPTFPT13_WRITE_ACTIONS,
                                OFPTFPT13_WRITE_SETFIELD, miss_offset, version);
      put_table_action_features(reply, &tif->apply,
                                OFPTFPT13_APPLY_ACTIONS,
                                OFPTFPT13_APPLY_SETFIELD, miss_offset, version);
  }
  
  void
  ofputil_append_table_features_reply(const struct ofputil_table_features *tf,
                                      struct ovs_list *replies)
  {
      struct ofpbuf *reply = ofpbuf_from_list(list_back(replies));
      enum ofp_version version = ofpmp_version(replies);
      size_t start_ofs = reply->size;
      struct ofp13_table_features *otf;
  
      otf = ofpbuf_put_zeros(reply, sizeof *otf);
      otf->table_id = tf->table_id;
      ovs_strlcpy(otf->name, tf->name, sizeof otf->name);
      otf->metadata_match = tf->metadata_match;
      otf->metadata_write = tf->metadata_write;
      if (version >= OFP14_VERSION) {
          if (tf->supports_eviction) {
              otf->capabilities |= htonl(OFPTC14_EVICTION);
          }
          if (tf->supports_vacancy_events) {
              otf->capabilities |= htonl(OFPTC14_VACANCY_EVENTS);
          }
      }
      otf->max_entries = htonl(tf->max_entries);
  
      put_table_instruction_features(reply, &tf->nonmiss, 0, version);
      put_table_instruction_features(reply, &tf->miss, 1, version);
  
      put_fields_property(reply, &tf->match, &tf->mask,
                          OFPTFPT13_MATCH, version);
      put_fields_property(reply, &tf->wildcard, NULL,
                          OFPTFPT13_WILDCARDS, version);
  
      otf = ofpbuf_at_assert(reply, start_ofs, sizeof *otf);
      otf->length = htons(reply->size - start_ofs);
      ofpmp_postappend(replies, start_ofs);
  }
  
  static enum ofperr
  parse_table_desc_eviction_property(struct ofpbuf *property,
                                     struct ofputil_table_desc *td)
  {
      struct ofp14_table_mod_prop_eviction *ote = property->data;
  
      if (property->size != sizeof *ote) {
          return OFPERR_OFPBPC_BAD_LEN;
      }
  
      td->eviction_flags = ntohl(ote->flags);
      return 0;
  }
  
  /* Decodes the next OpenFlow "table desc" message (of possibly several) from
   * 'msg' into an abstract form in '*td'.  Returns 0 if successful, EOF if the
   * last "table desc" in 'msg' was already decoded, otherwise an OFPERR_*
   * value. */
  int
  ofputil_decode_table_desc(struct ofpbuf *msg,
                            struct ofputil_table_desc *td,
                            enum ofp_version version)
  {
      struct ofp14_table_desc *otd;
      struct ofpbuf properties;
      size_t length;
  
      memset(td, 0, sizeof *td);
  
      if (!msg->header) {
          ofpraw_pull_assert(msg);
      }
  
      if (!msg->size) {
          return EOF;
      }
  
      otd = ofpbuf_try_pull(msg, sizeof *otd);
      if (!otd) {
          VLOG_WARN_RL(&bad_ofmsg_rl, "OFP14_TABLE_DESC reply has %"PRIu32" "
                       "leftover bytes at end", msg->size);
          return OFPERR_OFPBRC_BAD_LEN;
      }
  
      td->table_id = otd->table_id;
      length = ntohs(otd->length);
      if (length < sizeof *otd || length - sizeof *otd > msg->size) {
          VLOG_WARN_RL(&bad_ofmsg_rl, "OFP14_TABLE_DESC reply claims invalid "
                       "length %"PRIuSIZE, length);
          return OFPERR_OFPBRC_BAD_LEN;
      }
      length -= sizeof *otd;
      ofpbuf_use_const(&properties, ofpbuf_pull(msg, length), length);
  
      td->eviction = ofputil_decode_table_eviction(otd->config, version);
      td->eviction_flags = UINT32_MAX;
  
      while (properties.size > 0) {
          struct ofpbuf payload;
          enum ofperr error;
          uint16_t type;
  
          error = ofputil_pull_property(&properties, &payload, &type);
          if (error) {
              return error;
          }
  
          switch (type) {
          case OFPTMPT14_EVICTION:
              error = parse_table_desc_eviction_property(&payload, td);
              break;
  
          default:
              log_property(true, "unknown table_desc property %"PRIu16, type);
              error = 0;
              break;
          }
  
          if (error) {
              return error;
          }
      }
  
      return 0;
  }
  
  /* Encodes and returns a request to obtain description of tables of a switch.
   * The message is encoded for OpenFlow version 'ofp_version'. */
  struct ofpbuf *
  ofputil_encode_table_desc_request(enum ofp_version ofp_version)
  {
      struct ofpbuf *request = NULL;
  
      if (ofp_version >= OFP14_VERSION) {
          request = ofpraw_alloc(OFPRAW_OFPST14_TABLE_DESC_REQUEST,
                                 ofp_version, 0);
      } else {
          ovs_fatal(0, "dump-table-desc needs OpenFlow 1.4 or later "
                    "(\'-O OpenFlow14\')");
      }
  
      return request;
  }
  
  /* Function to append Table desc information in a reply list. */
  void
  ofputil_append_table_desc_reply(const struct ofputil_table_desc *td,
                                  struct ovs_list *replies,
                                  enum ofp_version version)
  {
      struct ofpbuf *reply = ofpbuf_from_list(list_back(replies));
      size_t start_otd;
      struct ofp14_table_desc *otd;
  
      start_otd = reply->size;
      ofpbuf_put_zeros(reply, sizeof *otd);
      if (td->eviction_flags != UINT32_MAX) {
          struct ofp14_table_mod_prop_eviction *ote;
  
          ote = ofpbuf_put_zeros(reply, sizeof *ote);
          ote->type = htons(OFPTMPT14_EVICTION);
          ote->length = htons(sizeof *ote);
          ote->flags = htonl(td->eviction_flags);
      }
  
      otd = ofpbuf_at_assert(reply, start_otd, sizeof *otd);
      otd->length = htons(reply->size - start_otd);
      otd->table_id = td->table_id;
      otd->config = ofputil_encode_table_config(OFPUTIL_TABLE_MISS_DEFAULT,
                                                td->eviction, version);
      ofpmp_postappend(replies, start_otd);
  }
  
  static enum ofperr
  parse_table_mod_eviction_property(struct ofpbuf *property,
                                    struct ofputil_table_mod *tm)
  {
      struct ofp14_table_mod_prop_eviction *ote = property->data;
  
      if (property->size != sizeof *ote) {
          return OFPERR_OFPBPC_BAD_LEN;
      }
  
      tm->eviction_flags = ntohl(ote->flags);
      return 0;
  }
  
  /* Given 'config', taken from an OpenFlow 'version' message that specifies
   * table configuration (a table mod, table stats, or table features message),
   * returns the table eviction configuration that it specifies.
   *
   * Only OpenFlow 1.4 and later specify table eviction configuration this way,
   * so for other 'version' values this function always returns
   * OFPUTIL_TABLE_EVICTION_DEFAULT. */
  static enum ofputil_table_eviction
  ofputil_decode_table_eviction(ovs_be32 config, enum ofp_version version)
  {
      return (version < OFP14_VERSION ? OFPUTIL_TABLE_EVICTION_DEFAULT
              : config & htonl(OFPTC14_EVICTION) ? OFPUTIL_TABLE_EVICTION_ON
              : OFPUTIL_TABLE_EVICTION_OFF);
  }
  
  /* Returns a bitmap of OFPTC* values suitable for 'config' fields in various
   * OpenFlow messages of the given 'version', based on the provided 'miss' and
   * 'eviction' values. */
  static ovs_be32
  ofputil_encode_table_config(enum ofputil_table_miss miss,
                              enum ofputil_table_eviction eviction,
                              enum ofp_version version)
  {
      /* See the section "OFPTC_* Table Configuration" in DESIGN.md for more
       * information on the crazy evolution of this field. */
      switch (version) {
      case OFP10_VERSION:
          /* OpenFlow 1.0 didn't have such a field, any value ought to do. */
          return htonl(0);
  
      case OFP11_VERSION:
      case OFP12_VERSION:
          /* OpenFlow 1.1 and 1.2 define only OFPTC11_TABLE_MISS_*. */
          switch (miss) {
          case OFPUTIL_TABLE_MISS_DEFAULT:
              /* Really this shouldn't be used for encoding (the caller should
               * provide a specific value) but I can't imagine that defaulting to
               * the fall-through case here will hurt. */
          case OFPUTIL_TABLE_MISS_CONTROLLER:
          default:
              return htonl(OFPTC11_TABLE_MISS_CONTROLLER);
          case OFPUTIL_TABLE_MISS_CONTINUE:
              return htonl(OFPTC11_TABLE_MISS_CONTINUE);
          case OFPUTIL_TABLE_MISS_DROP:
              return htonl(OFPTC11_TABLE_MISS_DROP);
          }
          OVS_NOT_REACHED();
  
      case OFP13_VERSION:
          /* OpenFlow 1.3 removed OFPTC11_TABLE_MISS_* and didn't define any new
           * flags, so this is correct. */
          return htonl(0);
  
      case OFP14_VERSION:
      case OFP15_VERSION:
          /* OpenFlow 1.4 introduced OFPTC14_EVICTION and OFPTC14_VACANCY_EVENTS
           * and we don't support the latter yet. */
          return htonl(eviction == OFPUTIL_TABLE_EVICTION_ON
                       ? OFPTC14_EVICTION : 0);
      }
  
      OVS_NOT_REACHED();
  }
  
  /* Given 'config', taken from an OpenFlow 'version' message that specifies
   * table configuration (a table mod, table stats, or table features message),
   * returns the table miss configuration that it specifies.
   *
   * Only OpenFlow 1.1 and 1.2 specify table miss configurations this way, so for
   * other 'version' values this function always returns
   * OFPUTIL_TABLE_MISS_DEFAULT. */
  static enum ofputil_table_miss
  ofputil_decode_table_miss(ovs_be32 config_, enum ofp_version version)
  {
      uint32_t config = ntohl(config_);
  
      if (version == OFP11_VERSION || version == OFP12_VERSION) {
          switch (config & OFPTC11_TABLE_MISS_MASK) {
          case OFPTC11_TABLE_MISS_CONTROLLER:
              return OFPUTIL_TABLE_MISS_CONTROLLER;
  
          case OFPTC11_TABLE_MISS_CONTINUE:
              return OFPUTIL_TABLE_MISS_CONTINUE;
  
          case OFPTC11_TABLE_MISS_DROP:
              return OFPUTIL_TABLE_MISS_DROP;
  
          default:
              VLOG_WARN_RL(&bad_ofmsg_rl, "bad table miss config %d", config);
              return OFPUTIL_TABLE_MISS_CONTROLLER;
          }
      } else {
          return OFPUTIL_TABLE_MISS_DEFAULT;
      }
  }
  
  /* Decodes the OpenFlow "table mod" message in '*oh' into an abstract form in
   * '*pm'.  Returns 0 if successful, otherwise an OFPERR_* value. */
  enum ofperr
  ofputil_decode_table_mod(const struct ofp_header *oh,
                           struct ofputil_table_mod *pm)
  {
      enum ofpraw raw;
      struct ofpbuf b;
  
      memset(pm, 0, sizeof *pm);
      pm->miss = OFPUTIL_TABLE_MISS_DEFAULT;
      pm->eviction = OFPUTIL_TABLE_EVICTION_DEFAULT;
      pm->eviction_flags = UINT32_MAX;
      ofpbuf_use_const(&b, oh, ntohs(oh->length));
      raw = ofpraw_pull_assert(&b);
  
      if (raw == OFPRAW_OFPT11_TABLE_MOD) {
          const struct ofp11_table_mod *otm = b.data;
  
          pm->table_id = otm->table_id;
          pm->miss = ofputil_decode_table_miss(otm->config, oh->version);
      } else if (raw == OFPRAW_OFPT14_TABLE_MOD) {
          const struct ofp14_table_mod *otm = ofpbuf_pull(&b, sizeof *otm);
  
          pm->table_id = otm->table_id;
          pm->miss = ofputil_decode_table_miss(otm->config, oh->version);
          pm->eviction = ofputil_decode_table_eviction(otm->config, oh->version);
          while (b.size > 0) {
              struct ofpbuf property;
              enum ofperr error;
              uint16_t type;
  
              error = ofputil_pull_property(&b, &property, &type);
              if (error) {
                  return error;
              }
  
              switch (type) {
              case OFPTMPT14_EVICTION:
                  error = parse_table_mod_eviction_property(&property, pm);
                  break;
  
              default:
                  error = OFPERR_OFPBRC_BAD_TYPE;
                  break;
              }
  
              if (error) {
                  return error;
              }
          }
      } else {
          return OFPERR_OFPBRC_BAD_TYPE;
      }
  
      return 0;
  }
  
  /* Converts the abstract form of a "table mod" message in '*tm' into an
   * OpenFlow message suitable for 'protocol', and returns that encoded form in a
   * buffer owned by the caller. */
  struct ofpbuf *
  ofputil_encode_table_mod(const struct ofputil_table_mod *tm,
                          enum ofputil_protocol protocol)
  {
      enum ofp_version ofp_version = ofputil_protocol_to_ofp_version(protocol);
      struct ofpbuf *b;
  
      switch (ofp_version) {
      case OFP10_VERSION: {
          ovs_fatal(0, "table mod needs OpenFlow 1.1 or later "
                       "(\'-O OpenFlow11\')");
          break;
      }
      case OFP11_VERSION:
      case OFP12_VERSION:
      case OFP13_VERSION: {
          struct ofp11_table_mod *otm;
  
          b = ofpraw_alloc(OFPRAW_OFPT11_TABLE_MOD, ofp_version, 0);
          otm = ofpbuf_put_zeros(b, sizeof *otm);
          otm->table_id = tm->table_id;
          otm->config = ofputil_encode_table_config(tm->miss, tm->eviction,
                                                    ofp_version);
          break;
      }
      case OFP14_VERSION:
      case OFP15_VERSION: {
          struct ofp14_table_mod *otm;
          struct ofp14_table_mod_prop_eviction *ote;
  
          b = ofpraw_alloc(OFPRAW_OFPT14_TABLE_MOD, ofp_version, 0);
          otm = ofpbuf_put_zeros(b, sizeof *otm);
          otm->table_id = tm->table_id;
          otm->config = ofputil_encode_table_config(tm->miss, tm->eviction,
                                                    ofp_version);
  
          if (tm->eviction_flags != UINT32_MAX) {
              ote = ofpbuf_put_zeros(b, sizeof *ote);
              ote->type = htons(OFPTMPT14_EVICTION);
              ote->length = htons(sizeof *ote);
              ote->flags = htonl(tm->eviction_flags);
          }
          break;
      }
      default:
          OVS_NOT_REACHED();
      }
  
      return b;
  }
  
  /* ofputil_role_request */
  
  /* Decodes the OpenFlow "role request" or "role reply" message in '*oh' into
   * an abstract form in '*rr'.  Returns 0 if successful, otherwise an
   * OFPERR_* value. */
  enum ofperr
  ofputil_decode_role_message(const struct ofp_header *oh,
                              struct ofputil_role_request *rr)
  {
      struct ofpbuf b;
      enum ofpraw raw;
  
      ofpbuf_use_const(&b, oh, ntohs(oh->length));
      raw = ofpraw_pull_assert(&b);
  
      if (raw == OFPRAW_OFPT12_ROLE_REQUEST ||
          raw == OFPRAW_OFPT12_ROLE_REPLY) {
          const struct ofp12_role_request *orr = b.msg;
  
          if (orr->role != htonl(OFPCR12_ROLE_NOCHANGE) &&
              orr->role != htonl(OFPCR12_ROLE_EQUAL) &&
              orr->role != htonl(OFPCR12_ROLE_MASTER) &&
              orr->role != htonl(OFPCR12_ROLE_SLAVE)) {
              return OFPERR_OFPRRFC_BAD_ROLE;
          }
  
          rr->role = ntohl(orr->role);
          if (raw == OFPRAW_OFPT12_ROLE_REQUEST
              ? orr->role == htonl(OFPCR12_ROLE_NOCHANGE)
              : orr->generation_id == OVS_BE64_MAX) {
              rr->have_generation_id = false;
              rr->generation_id = 0;
          } else {
              rr->have_generation_id = true;
              rr->generation_id = ntohll(orr->generation_id);
          }
      } else if (raw == OFPRAW_NXT_ROLE_REQUEST ||
                 raw == OFPRAW_NXT_ROLE_REPLY) {
          const struct nx_role_request *nrr = b.msg;
  
          BUILD_ASSERT(NX_ROLE_OTHER + 1 == OFPCR12_ROLE_EQUAL);
          BUILD_ASSERT(NX_ROLE_MASTER + 1 == OFPCR12_ROLE_MASTER);
          BUILD_ASSERT(NX_ROLE_SLAVE + 1 == OFPCR12_ROLE_SLAVE);
  
          if (nrr->role != htonl(NX_ROLE_OTHER) &&
              nrr->role != htonl(NX_ROLE_MASTER) &&
              nrr->role != htonl(NX_ROLE_SLAVE)) {
              return OFPERR_OFPRRFC_BAD_ROLE;
          }
  
          rr->role = ntohl(nrr->role) + 1;
          rr->have_generation_id = false;
          rr->generation_id = 0;
      } else {
          OVS_NOT_REACHED();
      }
  
      return 0;
  }
  
  /* Returns an encoded form of a role reply suitable for the "request" in a
   * buffer owned by the caller. */
  struct ofpbuf *
  ofputil_encode_role_reply(const struct ofp_header *request,
                            const struct ofputil_role_request *rr)
  {
      struct ofpbuf *buf;
      enum ofpraw raw;
  
      raw = ofpraw_decode_assert(request);
      if (raw == OFPRAW_OFPT12_ROLE_REQUEST) {
          struct ofp12_role_request *orr;
  
          buf = ofpraw_alloc_reply(OFPRAW_OFPT12_ROLE_REPLY, request, 0);
          orr = ofpbuf_put_zeros(buf, sizeof *orr);
  
          orr->role = htonl(rr->role);
          orr->generation_id = htonll(rr->have_generation_id
                                      ? rr->generation_id
                                      : UINT64_MAX);
      } else if (raw == OFPRAW_NXT_ROLE_REQUEST) {
          struct nx_role_request *nrr;
  
          BUILD_ASSERT(NX_ROLE_OTHER == OFPCR12_ROLE_EQUAL - 1);
          BUILD_ASSERT(NX_ROLE_MASTER == OFPCR12_ROLE_MASTER - 1);
          BUILD_ASSERT(NX_ROLE_SLAVE == OFPCR12_ROLE_SLAVE - 1);
  
          buf = ofpraw_alloc_reply(OFPRAW_NXT_ROLE_REPLY, request, 0);
          nrr = ofpbuf_put_zeros(buf, sizeof *nrr);
          nrr->role = htonl(rr->role - 1);
      } else {
          OVS_NOT_REACHED();
      }
  
      return buf;
  }
  
  /* Encodes "role status" message 'status' for sending in the given
   * 'protocol'.  Returns the role status message, if 'protocol' supports them,
   * otherwise a null pointer. */
  struct ofpbuf *
  ofputil_encode_role_status(const struct ofputil_role_status *status,
                             enum ofputil_protocol protocol)
  {
      enum ofp_version version;
  
      version = ofputil_protocol_to_ofp_version(protocol);
      if (version >= OFP14_VERSION) {
          struct ofp14_role_status *rstatus;
          struct ofpbuf *buf;
  
          buf = ofpraw_alloc_xid(OFPRAW_OFPT14_ROLE_STATUS, version, htonl(0),
                                 0);
          rstatus = ofpbuf_put_zeros(buf, sizeof *rstatus);
          rstatus->role = htonl(status->role);
          rstatus->reason = status->reason;
          rstatus->generation_id = htonll(status->generation_id);
  
          return buf;
      } else {
          return NULL;
      }
  }
  
  enum ofperr
  ofputil_decode_role_status(const struct ofp_header *oh,
                             struct ofputil_role_status *rs)
  {
      struct ofpbuf b;
      enum ofpraw raw;
      const struct ofp14_role_status *r;
  
      ofpbuf_use_const(&b, oh, ntohs(oh->length));
      raw = ofpraw_pull_assert(&b);
      ovs_assert(raw == OFPRAW_OFPT14_ROLE_STATUS);
  
      r = b.msg;
      if (r->role != htonl(OFPCR12_ROLE_NOCHANGE) &&
          r->role != htonl(OFPCR12_ROLE_EQUAL) &&
          r->role != htonl(OFPCR12_ROLE_MASTER) &&
          r->role != htonl(OFPCR12_ROLE_SLAVE)) {
          return OFPERR_OFPRRFC_BAD_ROLE;
      }
  
      rs->role = ntohl(r->role);
      rs->generation_id = ntohll(r->generation_id);
      rs->reason = r->reason;
  
      return 0;
  }
  
  /* Table stats. */
  
  /* OpenFlow 1.0 and 1.1 don't distinguish between a field that cannot be
   * matched and a field that must be wildcarded.  This function returns a bitmap
   * that contains both kinds of fields. */
  static struct mf_bitmap
  wild_or_nonmatchable_fields(const struct ofputil_table_features *features)
  {
      struct mf_bitmap wc = features->match;
      bitmap_not(wc.bm, MFF_N_IDS);
      bitmap_or(wc.bm, features->wildcard.bm, MFF_N_IDS);
      return wc;
  }
  
  struct ofp10_wc_map {
      enum ofp10_flow_wildcards wc10;
      enum mf_field_id mf;
  };
  
  static const struct ofp10_wc_map ofp10_wc_map[] = {
      { OFPFW10_IN_PORT,     MFF_IN_PORT },
      { OFPFW10_DL_VLAN,     MFF_VLAN_VID },
      { OFPFW10_DL_SRC,      MFF_ETH_SRC },
      { OFPFW10_DL_DST,      MFF_ETH_DST},
      { OFPFW10_DL_TYPE,     MFF_ETH_TYPE },
      { OFPFW10_NW_PROTO,    MFF_IP_PROTO },
      { OFPFW10_TP_SRC,      MFF_TCP_SRC },
      { OFPFW10_TP_DST,      MFF_TCP_DST },
      { OFPFW10_NW_SRC_MASK, MFF_IPV4_SRC },
      { OFPFW10_NW_DST_MASK, MFF_IPV4_DST },
      { OFPFW10_DL_VLAN_PCP, MFF_VLAN_PCP },
      { OFPFW10_NW_TOS,      MFF_IP_DSCP },
  };
  
  static ovs_be32
  mf_bitmap_to_of10(const struct mf_bitmap *fields)
  {
      const struct ofp10_wc_map *p;
      uint32_t wc10 = 0;
  
      for (p = ofp10_wc_map; p < &ofp10_wc_map[ARRAY_SIZE(ofp10_wc_map)]; p++) {
          if (bitmap_is_set(fields->bm, p->mf)) {
              wc10 |= p->wc10;
          }
      }
      return htonl(wc10);
  }
  
  static struct mf_bitmap
  mf_bitmap_from_of10(ovs_be32 wc10_)
  {
      struct mf_bitmap fields = MF_BITMAP_INITIALIZER;
      const struct ofp10_wc_map *p;
      uint32_t wc10 = ntohl(wc10_);
  
      for (p = ofp10_wc_map; p < &ofp10_wc_map[ARRAY_SIZE(ofp10_wc_map)]; p++) {
          if (wc10 & p->wc10) {
              bitmap_set1(fields.bm, p->mf);
          }
      }
      return fields;
  }
  
  static void
  ofputil_put_ofp10_table_stats(const struct ofputil_table_stats *stats,
                                const struct ofputil_table_features *features,
                                struct ofpbuf *buf)
  {
      struct mf_bitmap wc = wild_or_nonmatchable_fields(features);
      struct ofp10_table_stats *out;
  
      out = ofpbuf_put_zeros(buf, sizeof *out);
      out->table_id = features->table_id;
      ovs_strlcpy(out->name, features->name, sizeof out->name);
      out->wildcards = mf_bitmap_to_of10(&wc);
      out->max_entries = htonl(features->max_entries);
      out->active_count = htonl(stats->active_count);
      put_32aligned_be64(&out->lookup_count, htonll(stats->lookup_count));
      put_32aligned_be64(&out->matched_count, htonll(stats->matched_count));
  }
  
  struct ofp11_wc_map {
      enum ofp11_flow_match_fields wc11;
      enum mf_field_id mf;
  };
  
  static const struct ofp11_wc_map ofp11_wc_map[] = {
      { OFPFMF11_IN_PORT,     MFF_IN_PORT },
      { OFPFMF11_DL_VLAN,     MFF_VLAN_VID },
      { OFPFMF11_DL_VLAN_PCP, MFF_VLAN_PCP },
      { OFPFMF11_DL_TYPE,     MFF_ETH_TYPE },
      { OFPFMF11_NW_TOS,      MFF_IP_DSCP },
      { OFPFMF11_NW_PROTO,    MFF_IP_PROTO },
      { OFPFMF11_TP_SRC,      MFF_TCP_SRC },
      { OFPFMF11_TP_DST,      MFF_TCP_DST },
      { OFPFMF11_MPLS_LABEL,  MFF_MPLS_LABEL },
      { OFPFMF11_MPLS_TC,     MFF_MPLS_TC },
      /* I don't know what OFPFMF11_TYPE means. */
      { OFPFMF11_DL_SRC,      MFF_ETH_SRC },
      { OFPFMF11_DL_DST,      MFF_ETH_DST },
      { OFPFMF11_NW_SRC,      MFF_IPV4_SRC },
      { OFPFMF11_NW_DST,      MFF_IPV4_DST },
      { OFPFMF11_METADATA,    MFF_METADATA },
  };
  
  static ovs_be32
  mf_bitmap_to_of11(const struct mf_bitmap *fields)
  {
      const struct ofp11_wc_map *p;
      uint32_t wc11 = 0;
  
      for (p = ofp11_wc_map; p < &ofp11_wc_map[ARRAY_SIZE(ofp11_wc_map)]; p++) {
          if (bitmap_is_set(fields->bm, p->mf)) {
              wc11 |= p->wc11;
          }
      }
      return htonl(wc11);
  }
  
  static struct mf_bitmap
  mf_bitmap_from_of11(ovs_be32 wc11_)
  {
      struct mf_bitmap fields = MF_BITMAP_INITIALIZER;
      const struct ofp11_wc_map *p;
      uint32_t wc11 = ntohl(wc11_);
  
      for (p = ofp11_wc_map; p < &ofp11_wc_map[ARRAY_SIZE(ofp11_wc_map)]; p++) {
          if (wc11 & p->wc11) {
              bitmap_set1(fields.bm, p->mf);
          }
      }
      return fields;
  }
  
  static void
  ofputil_put_ofp11_table_stats(const struct ofputil_table_stats *stats,
                                const struct ofputil_table_features *features,
                                struct ofpbuf *buf)
  {
      struct mf_bitmap wc = wild_or_nonmatchable_fields(features);
      struct ofp11_table_stats *out;
  
      out = ofpbuf_put_zeros(buf, sizeof *out);
      out->table_id = features->table_id;
      ovs_strlcpy(out->name, features->name, sizeof out->name);
      out->wildcards = mf_bitmap_to_of11(&wc);
      out->match = mf_bitmap_to_of11(&features->match);
      out->instructions = ovsinst_bitmap_to_openflow(
          features->nonmiss.instructions, OFP11_VERSION);
      out->write_actions = ofpact_bitmap_to_openflow(
          features->nonmiss.write.ofpacts, OFP11_VERSION);
      out->apply_actions = ofpact_bitmap_to_openflow(
          features->nonmiss.apply.ofpacts, OFP11_VERSION);
      out->config = htonl(features->miss_config);
      out->max_entries = htonl(features->max_entries);
      out->active_count = htonl(stats->active_count);
      out->lookup_count = htonll(stats->lookup_count);
      out->matched_count = htonll(stats->matched_count);
  }
  
  static void
  ofputil_put_ofp12_table_stats(const struct ofputil_table_stats *stats,
                                const struct ofputil_table_features *features,
                                struct ofpbuf *buf)
  {
      struct ofp12_table_stats *out;
  
      out = ofpbuf_put_zeros(buf, sizeof *out);
      out->table_id = features->table_id;
      ovs_strlcpy(out->name, features->name, sizeof out->name);
      out->match = oxm_bitmap_from_mf_bitmap(&features->match, OFP12_VERSION);
      out->wildcards = oxm_bitmap_from_mf_bitmap(&features->wildcard,
                                               OFP12_VERSION);
      out->write_actions = ofpact_bitmap_to_openflow(
          features->nonmiss.write.ofpacts, OFP12_VERSION);
      out->apply_actions = ofpact_bitmap_to_openflow(
          features->nonmiss.apply.ofpacts, OFP12_VERSION);
      out->write_setfields = oxm_bitmap_from_mf_bitmap(
          &features->nonmiss.write.set_fields, OFP12_VERSION);
      out->apply_setfields = oxm_bitmap_from_mf_bitmap(
          &features->nonmiss.apply.set_fields, OFP12_VERSION);
      out->metadata_match = features->metadata_match;
      out->metadata_write = features->metadata_write;
      out->instructions = ovsinst_bitmap_to_openflow(
          features->nonmiss.instructions, OFP12_VERSION);
      out->config = ofputil_encode_table_config(features->miss_config,
                                                OFPUTIL_TABLE_EVICTION_DEFAULT,
                                                OFP12_VERSION);
      out->max_entries = htonl(features->max_entries);
      out->active_count = htonl(stats->active_count);
      out->lookup_count = htonll(stats->lookup_count);
      out->matched_count = htonll(stats->matched_count);
  }
  
  static void
  ofputil_put_ofp13_table_stats(const struct ofputil_table_stats *stats,
                                struct ofpbuf *buf)
  {
      struct ofp13_table_stats *out;
  
      out = ofpbuf_put_zeros(buf, sizeof *out);
      out->table_id = stats->table_id;
      out->active_count = htonl(stats->active_count);
      out->lookup_count = htonll(stats->lookup_count);
      out->matched_count = htonll(stats->matched_count);
  }
  
  struct ofpbuf *
  ofputil_encode_table_stats_reply(const struct ofp_header *request)
  {
      return ofpraw_alloc_stats_reply(request, 0);
  }
  
  void
  ofputil_append_table_stats_reply(struct ofpbuf *reply,
                                   const struct ofputil_table_stats *stats,
                                   const struct ofputil_table_features *features)
  {
      struct ofp_header *oh = reply->header;
  
      ovs_assert(stats->table_id == features->table_id);
  
      switch ((enum ofp_version) oh->version) {
      case OFP10_VERSION:
          ofputil_put_ofp10_table_stats(stats, features, reply);
          break;
  
      case OFP11_VERSION:
          ofputil_put_ofp11_table_stats(stats, features, reply);
          break;
  
      case OFP12_VERSION:
          ofputil_put_ofp12_table_stats(stats, features, reply);
          break;
  
      case OFP13_VERSION:
      case OFP14_VERSION:
      case OFP15_VERSION:
          ofputil_put_ofp13_table_stats(stats, reply);
          break;
  
      default:
          OVS_NOT_REACHED();
      }
  }
  
  static int
  ofputil_decode_ofp10_table_stats(struct ofpbuf *msg,
                                   struct ofputil_table_stats *stats,
                                   struct ofputil_table_features *features)
  {
      struct ofp10_table_stats *ots;
  
      ots = ofpbuf_try_pull(msg, sizeof *ots);
      if (!ots) {
          return OFPERR_OFPBRC_BAD_LEN;
      }
  
      features->table_id = ots->table_id;
      ovs_strlcpy(features->name, ots->name, sizeof features->name);
      features->max_entries = ntohl(ots->max_entries);
      features->match = features->wildcard = mf_bitmap_from_of10(ots->wildcards);
  
      stats->table_id = ots->table_id;
      stats->active_count = ntohl(ots->active_count);
      stats->lookup_count = ntohll(get_32aligned_be64(&ots->lookup_count));
      stats->matched_count = ntohll(get_32aligned_be64(&ots->matched_count));
  
      return 0;
  }
  
  static int
  ofputil_decode_ofp11_table_stats(struct ofpbuf *msg,
                                   struct ofputil_table_stats *stats,
                                   struct ofputil_table_features *features)
  {
      struct ofp11_table_stats *ots;
  
      ots = ofpbuf_try_pull(msg, sizeof *ots);
      if (!ots) {
          return OFPERR_OFPBRC_BAD_LEN;
      }
  
      features->table_id = ots->table_id;
      ovs_strlcpy(features->name, ots->name, sizeof features->name);
      features->max_entries = ntohl(ots->max_entries);
      features->nonmiss.instructions = ovsinst_bitmap_from_openflow(
          ots->instructions, OFP11_VERSION);
      features->nonmiss.write.ofpacts = ofpact_bitmap_from_openflow(
          ots->write_actions, OFP11_VERSION);
      features->nonmiss.apply.ofpacts = ofpact_bitmap_from_openflow(
          ots->write_actions, OFP11_VERSION);
      features->miss = features->nonmiss;
      features->miss_config = ofputil_decode_table_miss(ots->config,
                                                        OFP11_VERSION);
      features->match = mf_bitmap_from_of11(ots->match);
      features->wildcard = mf_bitmap_from_of11(ots->wildcards);
      bitmap_or(features->match.bm, features->wildcard.bm, MFF_N_IDS);
  
      stats->table_id = ots->table_id;
      stats->active_count = ntohl(ots->active_count);
      stats->lookup_count = ntohll(ots->lookup_count);
      stats->matched_count = ntohll(ots->matched_count);
  
      return 0;
  }
  
  static int
  ofputil_decode_ofp12_table_stats(struct ofpbuf *msg,
                                   struct ofputil_table_stats *stats,
                                   struct ofputil_table_features *features)
  {
      struct ofp12_table_stats *ots;
  
      ots = ofpbuf_try_pull(msg, sizeof *ots);
      if (!ots) {
          return OFPERR_OFPBRC_BAD_LEN;
      }
  
      features->table_id = ots->table_id;
      ovs_strlcpy(features->name, ots->name, sizeof features->name);
      features->metadata_match = ots->metadata_match;
      features->metadata_write = ots->metadata_write;
      features->miss_config = ofputil_decode_table_miss(ots->config,
                                                        OFP12_VERSION);
      features->max_entries = ntohl(ots->max_entries);
  
      features->nonmiss.instructions = ovsinst_bitmap_from_openflow(
          ots->instructions, OFP12_VERSION);
      features->nonmiss.write.ofpacts = ofpact_bitmap_from_openflow(
          ots->write_actions, OFP12_VERSION);
      features->nonmiss.apply.ofpacts = ofpact_bitmap_from_openflow(
          ots->apply_actions, OFP12_VERSION);
      features->nonmiss.write.set_fields = oxm_bitmap_to_mf_bitmap(
          ots->write_setfields, OFP12_VERSION);
      features->nonmiss.apply.set_fields = oxm_bitmap_to_mf_bitmap(
          ots->apply_setfields, OFP12_VERSION);
      features->miss = features->nonmiss;
  
      features->match = oxm_bitmap_to_mf_bitmap(ots->match, OFP12_VERSION);
      features->wildcard = oxm_bitmap_to_mf_bitmap(ots->wildcards,
                                                   OFP12_VERSION);
      bitmap_or(features->match.bm, features->wildcard.bm, MFF_N_IDS);
  
      stats->table_id = ots->table_id;
      stats->active_count = ntohl(ots->active_count);
      stats->lookup_count = ntohll(ots->lookup_count);
      stats->matched_count = ntohll(ots->matched_count);
  
      return 0;
  }
  
  static int
  ofputil_decode_ofp13_table_stats(struct ofpbuf *msg,
                                   struct ofputil_table_stats *stats,
                                   struct ofputil_table_features *features)
  {
      struct ofp13_table_stats *ots;
  
      ots = ofpbuf_try_pull(msg, sizeof *ots);
      if (!ots) {
          return OFPERR_OFPBRC_BAD_LEN;
      }
  
      features->table_id = ots->table_id;
  
      stats->table_id = ots->table_id;
      stats->active_count = ntohl(ots->active_count);
      stats->lookup_count = ntohll(ots->lookup_count);
      stats->matched_count = ntohll(ots->matched_count);
  
      return 0;
  }
  
  int
  ofputil_decode_table_stats_reply(struct ofpbuf *msg,
                                   struct ofputil_table_stats *stats,
                                   struct ofputil_table_features *features)
  {
      const struct ofp_header *oh;
  
      if (!msg->header) {
          ofpraw_pull_assert(msg);
      }
      oh = msg->header;
  
      if (!msg->size) {
          return EOF;
      }
  
      memset(stats, 0, sizeof *stats);
      memset(features, 0, sizeof *features);
      features->supports_eviction = -1;
      features->supports_vacancy_events = -1;
  
      switch ((enum ofp_version) oh->version) {
      case OFP10_VERSION:
          return ofputil_decode_ofp10_table_stats(msg, stats, features);
  
      case OFP11_VERSION:
          return ofputil_decode_ofp11_table_stats(msg, stats, features);
  
      case OFP12_VERSION:
          return ofputil_decode_ofp12_table_stats(msg, stats, features);
  
      case OFP13_VERSION:
      case OFP14_VERSION:
      case OFP15_VERSION:
          return ofputil_decode_ofp13_table_stats(msg, stats, features);
  
      default:
          OVS_NOT_REACHED();
      }
  }
  
  /* ofputil_flow_monitor_request */
  
  /* Converts an NXST_FLOW_MONITOR request in 'msg' into an abstract
   * ofputil_flow_monitor_request in 'rq'.
   *
   * Multiple NXST_FLOW_MONITOR requests can be packed into a single OpenFlow
   * message.  Calling this function multiple times for a single 'msg' iterates
   * through the requests.  The caller must initially leave 'msg''s layer
   * pointers null and not modify them between calls.
   *
   * Returns 0 if successful, EOF if no requests were left in this 'msg',
   * otherwise an OFPERR_* value. */
  int
  ofputil_decode_flow_monitor_request(struct ofputil_flow_monitor_request *rq,
                                      struct ofpbuf *msg)
  {
      struct nx_flow_monitor_request *nfmr;
      uint16_t flags;
  
      if (!msg->header) {
          ofpraw_pull_assert(msg);
      }
  
      if (!msg->size) {
          return EOF;
      }
  
      nfmr = ofpbuf_try_pull(msg, sizeof *nfmr);
      if (!nfmr) {
          VLOG_WARN_RL(&bad_ofmsg_rl, "NXST_FLOW_MONITOR request has %"PRIu32" "
                       "leftover bytes at end", msg->size);
          return OFPERR_OFPBRC_BAD_LEN;
      }
  
      flags = ntohs(nfmr->flags);
      if (!(flags & (NXFMF_ADD | NXFMF_DELETE | NXFMF_MODIFY))
          || flags & ~(NXFMF_INITIAL | NXFMF_ADD | NXFMF_DELETE
                       | NXFMF_MODIFY | NXFMF_ACTIONS | NXFMF_OWN)) {
          VLOG_WARN_RL(&bad_ofmsg_rl, "NXST_FLOW_MONITOR has bad flags %#"PRIx16,
                       flags);
          return OFPERR_OFPMOFC_BAD_FLAGS;
      }
  
      if (!is_all_zeros(nfmr->zeros, sizeof nfmr->zeros)) {
          return OFPERR_NXBRC_MUST_BE_ZERO;
      }
  
      rq->id = ntohl(nfmr->id);
      rq->flags = flags;
      rq->out_port = u16_to_ofp(ntohs(nfmr->out_port));
      rq->table_id = nfmr->table_id;
  
      return nx_pull_match(msg, ntohs(nfmr->match_len), &rq->match, NULL, NULL);
  }
  
  void
  ofputil_append_flow_monitor_request(
      const struct ofputil_flow_monitor_request *rq, struct ofpbuf *msg)
  {
      struct nx_flow_monitor_request *nfmr;
      size_t start_ofs;
      int match_len;
  
      if (!msg->size) {
          ofpraw_put(OFPRAW_NXST_FLOW_MONITOR_REQUEST, OFP10_VERSION, msg);
      }
  
      start_ofs = msg->size;
      ofpbuf_put_zeros(msg, sizeof *nfmr);
      match_len = nx_put_match(msg, &rq->match, htonll(0), htonll(0));
  
      nfmr = ofpbuf_at_assert(msg, start_ofs, sizeof *nfmr);
      nfmr->id = htonl(rq->id);
      nfmr->flags = htons(rq->flags);
      nfmr->out_port = htons(ofp_to_u16(rq->out_port));
      nfmr->match_len = htons(match_len);
      nfmr->table_id = rq->table_id;
  }
  
  /* Converts an NXST_FLOW_MONITOR reply (also known as a flow update) in 'msg'
   * into an abstract ofputil_flow_update in 'update'.  The caller must have
   * initialized update->match to point to space allocated for a match.
   *
   * Uses 'ofpacts' to store the abstract OFPACT_* version of the update's
   * actions (except for NXFME_ABBREV, which never includes actions).  The caller
   * must initialize 'ofpacts' and retains ownership of it.  'update->ofpacts'
   * will point into the 'ofpacts' buffer.
   *
   * Multiple flow updates can be packed into a single OpenFlow message.  Calling
   * this function multiple times for a single 'msg' iterates through the
   * updates.  The caller must initially leave 'msg''s layer pointers null and
   * not modify them between calls.
   *
   * Returns 0 if successful, EOF if no updates were left in this 'msg',
   * otherwise an OFPERR_* value. */
  int
  ofputil_decode_flow_update(struct ofputil_flow_update *update,
                             struct ofpbuf *msg, struct ofpbuf *ofpacts)
  {
      struct nx_flow_update_header *nfuh;
      unsigned int length;
      struct ofp_header *oh;
  
      if (!msg->header) {
          ofpraw_pull_assert(msg);
      }
  
      if (!msg->size) {
          return EOF;
      }
  
      if (msg->size < sizeof(struct nx_flow_update_header)) {
          goto bad_len;
      }
  
      oh = msg->header;
  
      nfuh = msg->data;
      update->event = ntohs(nfuh->event);
      length = ntohs(nfuh->length);
      if (length > msg->size || length % 8) {
          goto bad_len;
      }
  
      if (update->event == NXFME_ABBREV) {
          struct nx_flow_update_abbrev *nfua;
  
          if (length != sizeof *nfua) {
              goto bad_len;
          }
  
          nfua = ofpbuf_pull(msg, sizeof *nfua);
          update->xid = nfua->xid;
          return 0;
      } else if (update->event == NXFME_ADDED
                 || update->event == NXFME_DELETED
                 || update->event == NXFME_MODIFIED) {
          struct nx_flow_update_full *nfuf;
          unsigned int actions_len;
          unsigned int match_len;
          enum ofperr error;
  
          if (length < sizeof *nfuf) {
              goto bad_len;
          }
  
          nfuf = ofpbuf_pull(msg, sizeof *nfuf);
          match_len = ntohs(nfuf->match_len);
          if (sizeof *nfuf + match_len > length) {
              goto bad_len;
          }
  
          update->reason = ntohs(nfuf->reason);
          update->idle_timeout = ntohs(nfuf->idle_timeout);
          update->hard_timeout = ntohs(nfuf->hard_timeout);
          update->table_id = nfuf->table_id;
          update->cookie = nfuf->cookie;
          update->priority = ntohs(nfuf->priority);
  
          error = nx_pull_match(msg, match_len, update->match, NULL, NULL);
          if (error) {
              return error;
          }
  
          actions_len = length - sizeof *nfuf - ROUND_UP(match_len, 8);
          error = ofpacts_pull_openflow_actions(msg, actions_len, oh->version,
                                                ofpacts);
          if (error) {
              return error;
          }
  
          update->ofpacts = ofpacts->data;
          update->ofpacts_len = ofpacts->size;
          return 0;
      } else {
          VLOG_WARN_RL(&bad_ofmsg_rl,
                       "NXST_FLOW_MONITOR reply has bad event %"PRIu16,
                       ntohs(nfuh->event));
          return OFPERR_NXBRC_FM_BAD_EVENT;
      }
  
  bad_len:
      VLOG_WARN_RL(&bad_ofmsg_rl, "NXST_FLOW_MONITOR reply has %"PRIu32" "
                   "leftover bytes at end", msg->size);
      return OFPERR_OFPBRC_BAD_LEN;
  }
  
  uint32_t
  ofputil_decode_flow_monitor_cancel(const struct ofp_header *oh)
  {
      const struct nx_flow_monitor_cancel *cancel = ofpmsg_body(oh);
  
      return ntohl(cancel->id);
  }
  
  struct ofpbuf *
  ofputil_encode_flow_monitor_cancel(uint32_t id)
  {
      struct nx_flow_monitor_cancel *nfmc;
      struct ofpbuf *msg;
  
      msg = ofpraw_alloc(OFPRAW_NXT_FLOW_MONITOR_CANCEL, OFP10_VERSION, 0);
      nfmc = ofpbuf_put_uninit(msg, sizeof *nfmc);
      nfmc->id = htonl(id);
      return msg;
  }
  
  void
  ofputil_start_flow_update(struct ovs_list *replies)
  {
      struct ofpbuf *msg;
  
      msg = ofpraw_alloc_xid(OFPRAW_NXST_FLOW_MONITOR_REPLY, OFP10_VERSION,
                             htonl(0), 1024);
  
      list_init(replies);
      list_push_back(replies, &msg->list_node);
  }
  
  void
  ofputil_append_flow_update(const struct ofputil_flow_update *update,
                             struct ovs_list *replies)
  {
      enum ofp_version version = ofpmp_version(replies);
      struct nx_flow_update_header *nfuh;
      struct ofpbuf *msg;
      size_t start_ofs;
  
      msg = ofpbuf_from_list(list_back(replies));
      start_ofs = msg->size;
  
      if (update->event == NXFME_ABBREV) {
          struct nx_flow_update_abbrev *nfua;
  
          nfua = ofpbuf_put_zeros(msg, sizeof *nfua);
          nfua->xid = update->xid;
      } else {
          struct nx_flow_update_full *nfuf;
          int match_len;
  
          ofpbuf_put_zeros(msg, sizeof *nfuf);
          match_len = nx_put_match(msg, update->match, htonll(0), htonll(0));
          ofpacts_put_openflow_actions(update->ofpacts, update->ofpacts_len, msg,
                                       version);
          nfuf = ofpbuf_at_assert(msg, start_ofs, sizeof *nfuf);
          nfuf->reason = htons(update->reason);
          nfuf->priority = htons(update->priority);
          nfuf->idle_timeout = htons(update->idle_timeout);
          nfuf->hard_timeout = htons(update->hard_timeout);
          nfuf->match_len = htons(match_len);
          nfuf->table_id = update->table_id;
          nfuf->cookie = update->cookie;
      }
  
      nfuh = ofpbuf_at_assert(msg, start_ofs, sizeof *nfuh);
      nfuh->length = htons(msg->size - start_ofs);
      nfuh->event = htons(update->event);
  
      ofpmp_postappend(replies, start_ofs);
  }
  
  struct ofpbuf *
  ofputil_encode_packet_out(const struct ofputil_packet_out *po,
                            enum ofputil_protocol protocol)
  {
      enum ofp_version ofp_version = ofputil_protocol_to_ofp_version(protocol);
      struct ofpbuf *msg;
      size_t size;
  
      size = po->ofpacts_len;
      if (po->buffer_id == UINT32_MAX) {
          size += po->packet_len;
      }
  
      switch (ofp_version) {
      case OFP10_VERSION: {
          struct ofp10_packet_out *opo;
          size_t actions_ofs;
  
          msg = ofpraw_alloc(OFPRAW_OFPT10_PACKET_OUT, OFP10_VERSION, size);
          ofpbuf_put_zeros(msg, sizeof *opo);
          actions_ofs = msg->size;
          ofpacts_put_openflow_actions(po->ofpacts, po->ofpacts_len, msg,
                                       ofp_version);
  
          opo = msg->msg;
          opo->buffer_id = htonl(po->buffer_id);
          opo->in_port = htons(ofp_to_u16(po->in_port));
          opo->actions_len = htons(msg->size - actions_ofs);
          break;
      }
  
      case OFP11_VERSION:
      case OFP12_VERSION:
      case OFP13_VERSION:
      case OFP14_VERSION:
      case OFP15_VERSION: {
          struct ofp11_packet_out *opo;
          size_t len;
  
          msg = ofpraw_alloc(OFPRAW_OFPT11_PACKET_OUT, ofp_version, size);
          ofpbuf_put_zeros(msg, sizeof *opo);
          len = ofpacts_put_openflow_actions(po->ofpacts, po->ofpacts_len, msg,
                                             ofp_version);
          opo = msg->msg;
          opo->buffer_id = htonl(po->buffer_id);
          opo->in_port = ofputil_port_to_ofp11(po->in_port);
          opo->actions_len = htons(len);
          break;
      }
  
      default:
          OVS_NOT_REACHED();
      }
  
      if (po->buffer_id == UINT32_MAX) {
          ofpbuf_put(msg, po->packet, po->packet_len);
      }
  
      ofpmsg_update_length(msg);
  
      return msg;
  }
  
  /* Creates and returns an OFPT_ECHO_REQUEST message with an empty payload. */
  struct ofpbuf *
  make_echo_request(enum ofp_version ofp_version)
  {
      return ofpraw_alloc_xid(OFPRAW_OFPT_ECHO_REQUEST, ofp_version,
                              htonl(0), 0);
  }
  
  /* Creates and returns an OFPT_ECHO_REPLY message matching the
   * OFPT_ECHO_REQUEST message in 'rq'. */
  struct ofpbuf *
  make_echo_reply(const struct ofp_header *rq)
  {
      struct ofpbuf rq_buf;
      struct ofpbuf *reply;
  
      ofpbuf_use_const(&rq_buf, rq, ntohs(rq->length));
      ofpraw_pull_assert(&rq_buf);
  
      reply = ofpraw_alloc_reply(OFPRAW_OFPT_ECHO_REPLY, rq, rq_buf.size);
      ofpbuf_put(reply, rq_buf.data, rq_buf.size);
      return reply;
  }
  
  struct ofpbuf *
  ofputil_encode_barrier_request(enum ofp_version ofp_version)
  {
      enum ofpraw type;
  
      switch (ofp_version) {
      case OFP15_VERSION:
      case OFP14_VERSION:
      case OFP13_VERSION:
      case OFP12_VERSION:
      case OFP11_VERSION:
          type = OFPRAW_OFPT11_BARRIER_REQUEST;
          break;
  
      case OFP10_VERSION:
          type = OFPRAW_OFPT10_BARRIER_REQUEST;
          break;
  
      default:
          OVS_NOT_REACHED();
      }
  
      return ofpraw_alloc(type, ofp_version, 0);
  }
  
  const char *
  ofputil_frag_handling_to_string(enum ofp_config_flags flags)
  {
      switch (flags & OFPC_FRAG_MASK) {
      case OFPC_FRAG_NORMAL:   return "normal";
      case OFPC_FRAG_DROP:     return "drop";
      case OFPC_FRAG_REASM:    return "reassemble";
      case OFPC_FRAG_NX_MATCH: return "nx-match";
      }
  
      OVS_NOT_REACHED();
  }
  
  bool
  ofputil_frag_handling_from_string(const char *s, enum ofp_config_flags *flags)
  {
      if (!strcasecmp(s, "normal")) {
          *flags = OFPC_FRAG_NORMAL;
      } else if (!strcasecmp(s, "drop")) {
          *flags = OFPC_FRAG_DROP;
      } else if (!strcasecmp(s, "reassemble")) {
          *flags = OFPC_FRAG_REASM;
      } else if (!strcasecmp(s, "nx-match")) {
          *flags = OFPC_FRAG_NX_MATCH;
      } else {
          return false;
      }
      return true;
  }
  
  /* Converts the OpenFlow 1.1+ port number 'ofp11_port' into an OpenFlow 1.0
   * port number and stores the latter in '*ofp10_port', for the purpose of
   * decoding OpenFlow 1.1+ protocol messages.  Returns 0 if successful,
   * otherwise an OFPERR_* number.  On error, stores OFPP_NONE in '*ofp10_port'.
   *
   * See the definition of OFP11_MAX for an explanation of the mapping. */
  enum ofperr
  ofputil_port_from_ofp11(ovs_be32 ofp11_port, ofp_port_t *ofp10_port)
  {
      uint32_t ofp11_port_h = ntohl(ofp11_port);
  
      if (ofp11_port_h < ofp_to_u16(OFPP_MAX)) {
          *ofp10_port = u16_to_ofp(ofp11_port_h);
          return 0;
      } else if (ofp11_port_h >= ofp11_to_u32(OFPP11_MAX)) {
          *ofp10_port = u16_to_ofp(ofp11_port_h - OFPP11_OFFSET);
          return 0;
      } else {
          *ofp10_port = OFPP_NONE;
          VLOG_WARN_RL(&bad_ofmsg_rl, "port %"PRIu32" is outside the supported "
                       "range 0 through %d or 0x%"PRIx32" through 0x%"PRIx32,
                       ofp11_port_h, ofp_to_u16(OFPP_MAX) - 1,
                       ofp11_to_u32(OFPP11_MAX), UINT32_MAX);
          return OFPERR_OFPBAC_BAD_OUT_PORT;
      }
  }
  
  /* Returns the OpenFlow 1.1+ port number equivalent to the OpenFlow 1.0 port
   * number 'ofp10_port', for encoding OpenFlow 1.1+ protocol messages.
   *
   * See the definition of OFP11_MAX for an explanation of the mapping. */
  ovs_be32
  ofputil_port_to_ofp11(ofp_port_t ofp10_port)
  {
      return htonl(ofp_to_u16(ofp10_port) < ofp_to_u16(OFPP_MAX)
                   ? ofp_to_u16(ofp10_port)
                   : ofp_to_u16(ofp10_port) + OFPP11_OFFSET);
  }
  
  #define OFPUTIL_NAMED_PORTS                     \
          OFPUTIL_NAMED_PORT(IN_PORT)             \
          OFPUTIL_NAMED_PORT(TABLE)               \
          OFPUTIL_NAMED_PORT(NORMAL)              \
          OFPUTIL_NAMED_PORT(FLOOD)               \
          OFPUTIL_NAMED_PORT(ALL)                 \
          OFPUTIL_NAMED_PORT(CONTROLLER)          \
          OFPUTIL_NAMED_PORT(LOCAL)               \
          OFPUTIL_NAMED_PORT(ANY)                 \
          OFPUTIL_NAMED_PORT(UNSET)
  
  /* For backwards compatibility, so that "none" is recognized as OFPP_ANY */
  #define OFPUTIL_NAMED_PORTS_WITH_NONE           \
          OFPUTIL_NAMED_PORTS                     \
          OFPUTIL_NAMED_PORT(NONE)
  
  /* Stores the port number represented by 's' into '*portp'.  's' may be an
   * integer or, for reserved ports, the standard OpenFlow name for the port
   * (e.g. "LOCAL").
   *
   * Returns true if successful, false if 's' is not a valid OpenFlow port number
   * or name.  The caller should issue an error message in this case, because
   * this function usually does not.  (This gives the caller an opportunity to
   * look up the port name another way, e.g. by contacting the switch and listing
   * the names of all its ports).
   *
   * This function accepts OpenFlow 1.0 port numbers.  It also accepts a subset
   * of OpenFlow 1.1+ port numbers, mapping those port numbers into the 16-bit
   * range as described in include/openflow/openflow-1.1.h. */
  bool
  ofputil_port_from_string(const char *s, ofp_port_t *portp)
  {
      unsigned int port32; /* int is at least 32 bits wide. */
  
      if (*s == '-') {
          VLOG_WARN("Negative value %s is not a valid port number.", s);
          return false;
      }
      *portp = 0;
      if (str_to_uint(s, 10, &port32)) {
          if (port32 < ofp_to_u16(OFPP_MAX)) {
              /* Pass. */
          } else if (port32 < ofp_to_u16(OFPP_FIRST_RESV)) {
              VLOG_WARN("port %u is a reserved OF1.0 port number that will "
                        "be translated to %u when talking to an OF1.1 or "
                        "later controller", port32, port32 + OFPP11_OFFSET);
          } else if (port32 <= ofp_to_u16(OFPP_LAST_RESV)) {
              char name[OFP_MAX_PORT_NAME_LEN];
  
              ofputil_port_to_string(u16_to_ofp(port32), name, sizeof name);
              VLOG_WARN_ONCE("referring to port %s as %"PRIu32" is deprecated "
                             "for compatibility with OpenFlow 1.1 and later",
                             name, port32);
          } else if (port32 < ofp11_to_u32(OFPP11_MAX)) {
              VLOG_WARN("port %u is outside the supported range 0 through "
                        "%"PRIx16" or 0x%x through 0x%"PRIx32, port32,
                        UINT16_MAX, ofp11_to_u32(OFPP11_MAX), UINT32_MAX);
              return false;
          } else {
              port32 -= OFPP11_OFFSET;
          }
  
          *portp = u16_to_ofp(port32);
          return true;
      } else {
          struct pair {
              const char *name;
              ofp_port_t value;
          };
          static const struct pair pairs[] = {
  #define OFPUTIL_NAMED_PORT(NAME) {#NAME, OFPP_##NAME},
              OFPUTIL_NAMED_PORTS_WITH_NONE
  #undef OFPUTIL_NAMED_PORT
          };
          const struct pair *p;
  
          for (p = pairs; p < &pairs[ARRAY_SIZE(pairs)]; p++) {
              if (!strcasecmp(s, p->name)) {
                  *portp = p->value;
                  return true;
              }
          }
          return false;
      }
  }
  
  /* Appends to 's' a string representation of the OpenFlow port number 'port'.
   * Most ports' string representation is just the port number, but for special
   * ports, e.g. OFPP_LOCAL, it is the name, e.g. "LOCAL". */
  void
  ofputil_format_port(ofp_port_t port, struct ds *s)
  {
      char name[OFP_MAX_PORT_NAME_LEN];
  
      ofputil_port_to_string(port, name, sizeof name);
      ds_put_cstr(s, name);
  }
  
  /* Puts in the 'bufsize' byte in 'namebuf' a null-terminated string
   * representation of OpenFlow port number 'port'.  Most ports are represented
   * as just the port number, but special ports, e.g. OFPP_LOCAL, are represented
   * by name, e.g. "LOCAL". */
  void
  ofputil_port_to_string(ofp_port_t port,
                         char namebuf[OFP_MAX_PORT_NAME_LEN], size_t bufsize)
  {
      switch (port) {
  #define OFPUTIL_NAMED_PORT(NAME)                        \
          case OFPP_##NAME:                               \
              ovs_strlcpy(namebuf, #NAME, bufsize);       \
              break;
          OFPUTIL_NAMED_PORTS
  #undef OFPUTIL_NAMED_PORT
  
      default:
          snprintf(namebuf, bufsize, "%"PRIu16, port);
          break;
      }
  }
  
  /* Stores the group id represented by 's' into '*group_idp'.  's' may be an
   * integer or, for reserved group IDs, the standard OpenFlow name for the group
   * (either "ANY" or "ALL").
   *
   * Returns true if successful, false if 's' is not a valid OpenFlow group ID or
   * name. */
  bool
  ofputil_group_from_string(const char *s, uint32_t *group_idp)
  {
      if (!strcasecmp(s, "any")) {
          *group_idp = OFPG11_ANY;
      } else if (!strcasecmp(s, "all")) {
          *group_idp = OFPG11_ALL;
      } else if (!str_to_uint(s, 10, group_idp)) {
          VLOG_WARN("%s is not a valid group ID.  (Valid group IDs are "
                    "32-bit nonnegative integers or the keywords ANY or "
                    "ALL.)", s);
          return false;
      }
  
      return true;
  }
  
  /* Appends to 's' a string representation of the OpenFlow group ID 'group_id'.
   * Most groups' string representation is just the number, but for special
   * groups, e.g. OFPG11_ALL, it is the name, e.g. "ALL". */
  void
  ofputil_format_group(uint32_t group_id, struct ds *s)
  {
      char name[MAX_GROUP_NAME_LEN];
  
      ofputil_group_to_string(group_id, name, sizeof name);
      ds_put_cstr(s, name);
  }
  
  
  /* Puts in the 'bufsize' byte in 'namebuf' a null-terminated string
   * representation of OpenFlow group ID 'group_id'.  Most group are represented
   * as just their number, but special groups, e.g. OFPG11_ALL, are represented
   * by name, e.g. "ALL". */
  void
  ofputil_group_to_string(uint32_t group_id,
                          char namebuf[MAX_GROUP_NAME_LEN + 1], size_t bufsize)
  {
      switch (group_id) {
      case OFPG11_ALL:
          ovs_strlcpy(namebuf, "ALL", bufsize);
          break;
  
      case OFPG11_ANY:
          ovs_strlcpy(namebuf, "ANY", bufsize);
          break;
  
      default:
          snprintf(namebuf, bufsize, "%"PRIu32, group_id);
          break;
      }
  }
  
  /* Given a buffer 'b' that contains an array of OpenFlow ports of type
   * 'ofp_version', tries to pull the first element from the array.  If
   * successful, initializes '*pp' with an abstract representation of the
   * port and returns 0.  If no ports remain to be decoded, returns EOF.
   * On an error, returns a positive OFPERR_* value. */
  int
  ofputil_pull_phy_port(enum ofp_version ofp_version, struct ofpbuf *b,
                        struct ofputil_phy_port *pp)
  {
      memset(pp, 0, sizeof *pp);
  
      switch (ofp_version) {
      case OFP10_VERSION: {
          const struct ofp10_phy_port *opp = ofpbuf_try_pull(b, sizeof *opp);
          return opp ? ofputil_decode_ofp10_phy_port(pp, opp) : EOF;
      }
      case OFP11_VERSION:
      case OFP12_VERSION:
      case OFP13_VERSION: {
          const struct ofp11_port *op = ofpbuf_try_pull(b, sizeof *op);
          return op ? ofputil_decode_ofp11_port(pp, op) : EOF;
      }
      case OFP14_VERSION:
      case OFP15_VERSION:
          return b->size ? ofputil_pull_ofp14_port(pp, b) : EOF;
      default:
          OVS_NOT_REACHED();
      }
  }
  
  static void
  ofputil_normalize_match__(struct match *match, bool may_log)
  {
      enum {
          MAY_NW_ADDR     = 1 << 0, /* nw_src, nw_dst */
          MAY_TP_ADDR     = 1 << 1, /* tp_src, tp_dst */
          MAY_NW_PROTO    = 1 << 2, /* nw_proto */
          MAY_IPVx        = 1 << 3, /* tos, frag, ttl */
          MAY_ARP_SHA     = 1 << 4, /* arp_sha */
          MAY_ARP_THA     = 1 << 5, /* arp_tha */
          MAY_IPV6        = 1 << 6, /* ipv6_src, ipv6_dst, ipv6_label */
          MAY_ND_TARGET   = 1 << 7, /* nd_target */
          MAY_MPLS        = 1 << 8, /* mpls label and tc */
      } may_match;
  
      struct flow_wildcards wc;
  
      /* Figure out what fields may be matched. */
      if (match->flow.dl_type == htons(ETH_TYPE_IP)) {
          may_match = MAY_NW_PROTO | MAY_IPVx | MAY_NW_ADDR;
          if (match->flow.nw_proto == IPPROTO_TCP ||
              match->flow.nw_proto == IPPROTO_UDP ||
              match->flow.nw_proto == IPPROTO_SCTP ||
              match->flow.nw_proto == IPPROTO_ICMP) {
              may_match |= MAY_TP_ADDR;
          }
      } else if (match->flow.dl_type == htons(ETH_TYPE_IPV6)) {
          may_match = MAY_NW_PROTO | MAY_IPVx | MAY_IPV6;
          if (match->flow.nw_proto == IPPROTO_TCP ||
              match->flow.nw_proto == IPPROTO_UDP ||
              match->flow.nw_proto == IPPROTO_SCTP) {
              may_match |= MAY_TP_ADDR;
          } else if (match->flow.nw_proto == IPPROTO_ICMPV6) {
              may_match |= MAY_TP_ADDR;
              if (match->flow.tp_src == htons(ND_NEIGHBOR_SOLICIT)) {
                  may_match |= MAY_ND_TARGET | MAY_ARP_SHA;
              } else if (match->flow.tp_src == htons(ND_NEIGHBOR_ADVERT)) {
                  may_match |= MAY_ND_TARGET | MAY_ARP_THA;
              }
          }
      } else if (match->flow.dl_type == htons(ETH_TYPE_ARP) ||
                 match->flow.dl_type == htons(ETH_TYPE_RARP)) {
          may_match = MAY_NW_PROTO | MAY_NW_ADDR | MAY_ARP_SHA | MAY_ARP_THA;
      } else if (eth_type_mpls(match->flow.dl_type)) {
          may_match = MAY_MPLS;
      } else {
          may_match = 0;
      }
  
      /* Clear the fields that may not be matched. */
      wc = match->wc;
      if (!(may_match & MAY_NW_ADDR)) {
          wc.masks.nw_src = wc.masks.nw_dst = htonl(0);
      }
      if (!(may_match & MAY_TP_ADDR)) {
          wc.masks.tp_src = wc.masks.tp_dst = htons(0);
      }
      if (!(may_match & MAY_NW_PROTO)) {
          wc.masks.nw_proto = 0;
      }
      if (!(may_match & MAY_IPVx)) {
          wc.masks.nw_tos = 0;
          wc.masks.nw_ttl = 0;
      }
      if (!(may_match & MAY_ARP_SHA)) {
          memset(wc.masks.arp_sha, 0, ETH_ADDR_LEN);
      }
      if (!(may_match & MAY_ARP_THA)) {
          memset(wc.masks.arp_tha, 0, ETH_ADDR_LEN);
      }
      if (!(may_match & MAY_IPV6)) {
          wc.masks.ipv6_src = wc.masks.ipv6_dst = in6addr_any;
          wc.masks.ipv6_label = htonl(0);
      }
      if (!(may_match & MAY_ND_TARGET)) {
          wc.masks.nd_target = in6addr_any;
      }
      if (!(may_match & MAY_MPLS)) {
          memset(wc.masks.mpls_lse, 0, sizeof wc.masks.mpls_lse);
      }
  
      /* Log any changes. */
      if (!flow_wildcards_equal(&wc, &match->wc)) {
          bool log = may_log && !VLOG_DROP_INFO(&bad_ofmsg_rl);
          char *pre = log ? match_to_string(match, OFP_DEFAULT_PRIORITY) : NULL;
  
          match->wc = wc;
          match_zero_wildcarded_fields(match);
  
          if (log) {
              char *post = match_to_string(match, OFP_DEFAULT_PRIORITY);
              VLOG_INFO("normalization changed ofp_match, details:");
              VLOG_INFO(" pre: %s", pre);
              VLOG_INFO("post: %s", post);
              free(pre);
              free(post);
          }
      }
  }
  
  /* "Normalizes" the wildcards in 'match'.  That means:
   *
   *    1. If the type of level N is known, then only the valid fields for that
   *       level may be specified.  For example, ARP does not have a TOS field,
   *       so nw_tos must be wildcarded if 'match' specifies an ARP flow.
   *       Similarly, IPv4 does not have any IPv6 addresses, so ipv6_src and
   *       ipv6_dst (and other fields) must be wildcarded if 'match' specifies an
   *       IPv4 flow.
   *
   *    2. If the type of level N is not known (or not understood by Open
   *       vSwitch), then no fields at all for that level may be specified.  For
   *       example, Open vSwitch does not understand SCTP, an L4 protocol, so the
   *       L4 fields tp_src and tp_dst must be wildcarded if 'match' specifies an
   *       SCTP flow.
   *
   * If this function changes 'match', it logs a rate-limited informational
   * message. */
  void
  ofputil_normalize_match(struct match *match)
  {
      ofputil_normalize_match__(match, true);
  }
  
  /* Same as ofputil_normalize_match() without the logging.  Thus, this function
   * is suitable for a program's internal use, whereas ofputil_normalize_match()
   * sense for use on flows received from elsewhere (so that a bug in the program
   * that sent them can be reported and corrected). */
  void
  ofputil_normalize_match_quiet(struct match *match)
  {
      ofputil_normalize_match__(match, false);
  }
  
  /* Parses a key or a key-value pair from '*stringp'.
   *
   * On success: Stores the key into '*keyp'.  Stores the value, if present, into
   * '*valuep', otherwise an empty string.  Advances '*stringp' past the end of
   * the key-value pair, preparing it for another call.  '*keyp' and '*valuep'
   * are substrings of '*stringp' created by replacing some of its bytes by null
   * terminators.  Returns true.
   *
   * If '*stringp' is just white space or commas, sets '*keyp' and '*valuep' to
   * NULL and returns false. */
  bool
  ofputil_parse_key_value(char **stringp, char **keyp, char **valuep)
  {
      char *pos, *key, *value;
      size_t key_len;
  
      pos = *stringp;
      pos += strspn(pos, ", \t\r\n");
      if (*pos == '\0') {
          *keyp = *valuep = NULL;
          return false;
      }
  
      key = pos;
      key_len = strcspn(pos, ":=(, \t\r\n");
      if (key[key_len] == ':' || key[key_len] == '=') {
          /* The value can be separated by a colon. */
          size_t value_len;
  
          value = key + key_len + 1;
          value_len = strcspn(value, ", \t\r\n");
          pos = value + value_len + (value[value_len] != '\0');
          value[value_len] = '\0';
      } else if (key[key_len] == '(') {
          /* The value can be surrounded by balanced parentheses.  The outermost
           * set of parentheses is removed. */
          int level = 1;
          size_t value_len;
  
          value = key + key_len + 1;
          for (value_len = 0; level > 0; value_len++) {
              switch (value[value_len]) {
              case '\0':
                  level = 0;
                  break;
  
              case '(':
                  level++;
                  break;
  
              case ')':
                  level--;
                  break;
              }
          }
          value[value_len - 1] = '\0';
          pos = value + value_len;
      } else {
          /* There might be no value at all. */
          value = key + key_len;  /* Will become the empty string below. */
          pos = key + key_len + (key[key_len] != '\0');
      }
      key[key_len] = '\0';
  
      *stringp = pos;
      *keyp = key;
      *valuep = value;
      return true;
  }
  
  /* Encode a dump ports request for 'port', the encoded message
   * will be for OpenFlow version 'ofp_version'. Returns message
   * as a struct ofpbuf. Returns encoded message on success, NULL on error */
  struct ofpbuf *
  ofputil_encode_dump_ports_request(enum ofp_version ofp_version, ofp_port_t port)
  {
      struct ofpbuf *request;
  
      switch (ofp_version) {
      case OFP10_VERSION: {
          struct ofp10_port_stats_request *req;
          request = ofpraw_alloc(OFPRAW_OFPST10_PORT_REQUEST, ofp_version, 0);
          req = ofpbuf_put_zeros(request, sizeof *req);
          req->port_no = htons(ofp_to_u16(port));
          break;
      }
      case OFP11_VERSION:
      case OFP12_VERSION:
      case OFP13_VERSION:
      case OFP14_VERSION:
      case OFP15_VERSION: {
          struct ofp11_port_stats_request *req;
          request = ofpraw_alloc(OFPRAW_OFPST11_PORT_REQUEST, ofp_version, 0);
          req = ofpbuf_put_zeros(request, sizeof *req);
          req->port_no = ofputil_port_to_ofp11(port);
          break;
      }
      default:
          OVS_NOT_REACHED();
      }
  
      return request;
  }
  
  static void
  ofputil_port_stats_to_ofp10(const struct ofputil_port_stats *ops,
                              struct ofp10_port_stats *ps10)
  {
      ps10->port_no = htons(ofp_to_u16(ops->port_no));
      memset(ps10->pad, 0, sizeof ps10->pad);
      put_32aligned_be64(&ps10->rx_packets, htonll(ops->stats.rx_packets));
      put_32aligned_be64(&ps10->tx_packets, htonll(ops->stats.tx_packets));
      put_32aligned_be64(&ps10->rx_bytes, htonll(ops->stats.rx_bytes));
      put_32aligned_be64(&ps10->tx_bytes, htonll(ops->stats.tx_bytes));
      put_32aligned_be64(&ps10->rx_dropped, htonll(ops->stats.rx_dropped));
      put_32aligned_be64(&ps10->tx_dropped, htonll(ops->stats.tx_dropped));
      put_32aligned_be64(&ps10->rx_errors, htonll(ops->stats.rx_errors));
      put_32aligned_be64(&ps10->tx_errors, htonll(ops->stats.tx_errors));
      put_32aligned_be64(&ps10->rx_frame_err, htonll(ops->stats.rx_frame_errors));
      put_32aligned_be64(&ps10->rx_over_err, htonll(ops->stats.rx_over_errors));
      put_32aligned_be64(&ps10->rx_crc_err, htonll(ops->stats.rx_crc_errors));
      put_32aligned_be64(&ps10->collisions, htonll(ops->stats.collisions));
  }
  
  static void
  ofputil_port_stats_to_ofp11(const struct ofputil_port_stats *ops,
                              struct ofp11_port_stats *ps11)
  {
      ps11->port_no = ofputil_port_to_ofp11(ops->port_no);
      memset(ps11->pad, 0, sizeof ps11->pad);
      ps11->rx_packets = htonll(ops->stats.rx_packets);
      ps11->tx_packets = htonll(ops->stats.tx_packets);
      ps11->rx_bytes = htonll(ops->stats.rx_bytes);
      ps11->tx_bytes = htonll(ops->stats.tx_bytes);
      ps11->rx_dropped = htonll(ops->stats.rx_dropped);
      ps11->tx_dropped = htonll(ops->stats.tx_dropped);
      ps11->rx_errors = htonll(ops->stats.rx_errors);
      ps11->tx_errors = htonll(ops->stats.tx_errors);
      ps11->rx_frame_err = htonll(ops->stats.rx_frame_errors);
      ps11->rx_over_err = htonll(ops->stats.rx_over_errors);
      ps11->rx_crc_err = htonll(ops->stats.rx_crc_errors);
      ps11->collisions = htonll(ops->stats.collisions);
  }
  
  static void
  ofputil_port_stats_to_ofp13(const struct ofputil_port_stats *ops,
                              struct ofp13_port_stats *ps13)
  {
      ofputil_port_stats_to_ofp11(ops, &ps13->ps);
      ps13->duration_sec = htonl(ops->duration_sec);
      ps13->duration_nsec = htonl(ops->duration_nsec);
  }
  
  static void
  ofputil_append_ofp14_port_stats(const struct ofputil_port_stats *ops,
                                  struct ovs_list *replies)
  {
      struct ofp14_port_stats_prop_ethernet *eth;
      struct ofp14_port_stats *ps14;
      struct ofpbuf *reply;
  
      reply = ofpmp_reserve(replies, sizeof *ps14 + sizeof *eth);
  
      ps14 = ofpbuf_put_uninit(reply, sizeof *ps14);
      ps14->length = htons(sizeof *ps14 + sizeof *eth);
      memset(ps14->pad, 0, sizeof ps14->pad);
      ps14->port_no = ofputil_port_to_ofp11(ops->port_no);
      ps14->duration_sec = htonl(ops->duration_sec);
      ps14->duration_nsec = htonl(ops->duration_nsec);
      ps14->rx_packets = htonll(ops->stats.rx_packets);
      ps14->tx_packets = htonll(ops->stats.tx_packets);
      ps14->rx_bytes = htonll(ops->stats.rx_bytes);
      ps14->tx_bytes = htonll(ops->stats.tx_bytes);
      ps14->rx_dropped = htonll(ops->stats.rx_dropped);
      ps14->tx_dropped = htonll(ops->stats.tx_dropped);
      ps14->rx_errors = htonll(ops->stats.rx_errors);
      ps14->tx_errors = htonll(ops->stats.tx_errors);
  
      eth = ofpbuf_put_uninit(reply, sizeof *eth);
      eth->type = htons(OFPPSPT14_ETHERNET);
      eth->length = htons(sizeof *eth);
      memset(eth->pad, 0, sizeof eth->pad);
      eth->rx_frame_err = htonll(ops->stats.rx_frame_errors);
      eth->rx_over_err = htonll(ops->stats.rx_over_errors);
      eth->rx_crc_err = htonll(ops->stats.rx_crc_errors);
      eth->collisions = htonll(ops->stats.collisions);
  }
  
  /* Encode a ports stat for 'ops' and append it to 'replies'. */
  void
  ofputil_append_port_stat(struct ovs_list *replies,
                           const struct ofputil_port_stats *ops)
  {
      switch (ofpmp_version(replies)) {
      case OFP13_VERSION: {
          struct ofp13_port_stats *reply = ofpmp_append(replies, sizeof *reply);
          ofputil_port_stats_to_ofp13(ops, reply);
          break;
      }
      case OFP12_VERSION:
      case OFP11_VERSION: {
          struct ofp11_port_stats *reply = ofpmp_append(replies, sizeof *reply);
          ofputil_port_stats_to_ofp11(ops, reply);
          break;
      }
  
      case OFP10_VERSION: {
          struct ofp10_port_stats *reply = ofpmp_append(replies, sizeof *reply);
          ofputil_port_stats_to_ofp10(ops, reply);
          break;
      }
  
      case OFP14_VERSION:
      case OFP15_VERSION:
          ofputil_append_ofp14_port_stats(ops, replies);
          break;
  
      default:
          OVS_NOT_REACHED();
      }
  }
  
  static enum ofperr
  ofputil_port_stats_from_ofp10(struct ofputil_port_stats *ops,
                                const struct ofp10_port_stats *ps10)
  {
      memset(ops, 0, sizeof *ops);
  
      ops->port_no = u16_to_ofp(ntohs(ps10->port_no));
      ops->stats.rx_packets = ntohll(get_32aligned_be64(&ps10->rx_packets));
      ops->stats.tx_packets = ntohll(get_32aligned_be64(&ps10->tx_packets));
      ops->stats.rx_bytes = ntohll(get_32aligned_be64(&ps10->rx_bytes));
      ops->stats.tx_bytes = ntohll(get_32aligned_be64(&ps10->tx_bytes));
      ops->stats.rx_dropped = ntohll(get_32aligned_be64(&ps10->rx_dropped));
      ops->stats.tx_dropped = ntohll(get_32aligned_be64(&ps10->tx_dropped));
      ops->stats.rx_errors = ntohll(get_32aligned_be64(&ps10->rx_errors));
      ops->stats.tx_errors = ntohll(get_32aligned_be64(&ps10->tx_errors));
      ops->stats.rx_frame_errors =
          ntohll(get_32aligned_be64(&ps10->rx_frame_err));
      ops->stats.rx_over_errors = ntohll(get_32aligned_be64(&ps10->rx_over_err));
      ops->stats.rx_crc_errors = ntohll(get_32aligned_be64(&ps10->rx_crc_err));
      ops->stats.collisions = ntohll(get_32aligned_be64(&ps10->collisions));
      ops->duration_sec = ops->duration_nsec = UINT32_MAX;
  
      return 0;
  }
  
  static enum ofperr
  ofputil_port_stats_from_ofp11(struct ofputil_port_stats *ops,
                                const struct ofp11_port_stats *ps11)
  {
      enum ofperr error;
  
      memset(ops, 0, sizeof *ops);
      error = ofputil_port_from_ofp11(ps11->port_no, &ops->port_no);
      if (error) {
          return error;
      }
  
      ops->stats.rx_packets = ntohll(ps11->rx_packets);
      ops->stats.tx_packets = ntohll(ps11->tx_packets);
      ops->stats.rx_bytes = ntohll(ps11->rx_bytes);
      ops->stats.tx_bytes = ntohll(ps11->tx_bytes);
      ops->stats.rx_dropped = ntohll(ps11->rx_dropped);
      ops->stats.tx_dropped = ntohll(ps11->tx_dropped);
      ops->stats.rx_errors = ntohll(ps11->rx_errors);
      ops->stats.tx_errors = ntohll(ps11->tx_errors);
      ops->stats.rx_frame_errors = ntohll(ps11->rx_frame_err);
      ops->stats.rx_over_errors = ntohll(ps11->rx_over_err);
      ops->stats.rx_crc_errors = ntohll(ps11->rx_crc_err);
      ops->stats.collisions = ntohll(ps11->collisions);
      ops->duration_sec = ops->duration_nsec = UINT32_MAX;
  
      return 0;
  }
  
  static enum ofperr
  ofputil_port_stats_from_ofp13(struct ofputil_port_stats *ops,
                                const struct ofp13_port_stats *ps13)
  {
      enum ofperr error = ofputil_port_stats_from_ofp11(ops, &ps13->ps);
      if (!error) {
          ops->duration_sec = ntohl(ps13->duration_sec);
          ops->duration_nsec = ntohl(ps13->duration_nsec);
      }
      return error;
  }
  
  static enum ofperr
  parse_ofp14_port_stats_ethernet_property(const struct ofpbuf *payload,
                                           struct ofputil_port_stats *ops)
  {
      const struct ofp14_port_stats_prop_ethernet *eth = payload->data;
  
      if (payload->size != sizeof *eth) {
          return OFPERR_OFPBPC_BAD_LEN;
      }
  
      ops->stats.rx_frame_errors = ntohll(eth->rx_frame_err);
      ops->stats.rx_over_errors = ntohll(eth->rx_over_err);
      ops->stats.rx_crc_errors = ntohll(eth->rx_crc_err);
      ops->stats.collisions = ntohll(eth->collisions);
  
      return 0;
  }
  
  static enum ofperr
  ofputil_pull_ofp14_port_stats(struct ofputil_port_stats *ops,
                                struct ofpbuf *msg)
  {
      const struct ofp14_port_stats *ps14;
      struct ofpbuf properties;
      enum ofperr error;
      size_t len;
  
      ps14 = ofpbuf_try_pull(msg, sizeof *ps14);
      if (!ps14) {
          return OFPERR_OFPBRC_BAD_LEN;
      }
  
      len = ntohs(ps14->length);
      if (len < sizeof *ps14 || len - sizeof *ps14 > msg->size) {
          return OFPERR_OFPBRC_BAD_LEN;
      }
      len -= sizeof *ps14;
      ofpbuf_use_const(&properties, ofpbuf_pull(msg, len), len);
  
      error = ofputil_port_from_ofp11(ps14->port_no, &ops->port_no);
      if (error) {
          return error;
      }
  
      ops->duration_sec = ntohl(ps14->duration_sec);
      ops->duration_nsec = ntohl(ps14->duration_nsec);
      ops->stats.rx_packets = ntohll(ps14->rx_packets);
      ops->stats.tx_packets = ntohll(ps14->tx_packets);
      ops->stats.rx_bytes = ntohll(ps14->rx_bytes);
      ops->stats.tx_bytes = ntohll(ps14->tx_bytes);
      ops->stats.rx_dropped = ntohll(ps14->rx_dropped);
      ops->stats.tx_dropped = ntohll(ps14->tx_dropped);
      ops->stats.rx_errors = ntohll(ps14->rx_errors);
      ops->stats.tx_errors = ntohll(ps14->tx_errors);
      ops->stats.rx_frame_errors = UINT64_MAX;
      ops->stats.rx_over_errors = UINT64_MAX;
      ops->stats.rx_crc_errors = UINT64_MAX;
      ops->stats.collisions = UINT64_MAX;
  
      while (properties.size > 0) {
          struct ofpbuf payload;
          enum ofperr error;
          uint16_t type;
  
          error = ofputil_pull_property(&properties, &payload, &type);
          if (error) {
              return error;
          }
  
          switch (type) {
          case OFPPSPT14_ETHERNET:
              error = parse_ofp14_port_stats_ethernet_property(&payload, ops);
              break;
  
          default:
              log_property(true, "unknown port stats property %"PRIu16, type);
              error = 0;
              break;
          }
  
          if (error) {
              return error;
          }
      }
  
      return 0;
  }
  
  /* Returns the number of port stats elements in OFPTYPE_PORT_STATS_REPLY
   * message 'oh'. */
  size_t
  ofputil_count_port_stats(const struct ofp_header *oh)
  {
      struct ofputil_port_stats ps;
      struct ofpbuf b;
      size_t n = 0;
  
      ofpbuf_use_const(&b, oh, ntohs(oh->length));
      ofpraw_pull_assert(&b);
      while (!ofputil_decode_port_stats(&ps, &b)) {
          n++;
      }
      return n;
  }
  
  /* Converts an OFPST_PORT_STATS reply in 'msg' into an abstract
   * ofputil_port_stats in 'ps'.
   *
   * Multiple OFPST_PORT_STATS replies can be packed into a single OpenFlow
   * message.  Calling this function multiple times for a single 'msg' iterates
   * through the replies.  The caller must initially leave 'msg''s layer pointers
   * null and not modify them between calls.
   *
   * Returns 0 if successful, EOF if no replies were left in this 'msg',
   * otherwise a positive errno value. */
  int
  ofputil_decode_port_stats(struct ofputil_port_stats *ps, struct ofpbuf *msg)
  {
      enum ofperr error;
      enum ofpraw raw;
  
      error = (msg->header ? ofpraw_decode(&raw, msg->header)
               : ofpraw_pull(&raw, msg));
      if (error) {
          return error;
      }
  
      if (!msg->size) {
          return EOF;
      } else if (raw == OFPRAW_OFPST14_PORT_REPLY) {
          return ofputil_pull_ofp14_port_stats(ps, msg);
      } else if (raw == OFPRAW_OFPST13_PORT_REPLY) {
          const struct ofp13_port_stats *ps13;
  
          ps13 = ofpbuf_try_pull(msg, sizeof *ps13);
          if (!ps13) {
              goto bad_len;
          }
          return ofputil_port_stats_from_ofp13(ps, ps13);
      } else if (raw == OFPRAW_OFPST11_PORT_REPLY) {
          const struct ofp11_port_stats *ps11;
  
          ps11 = ofpbuf_try_pull(msg, sizeof *ps11);
          if (!ps11) {
              goto bad_len;
          }
          return ofputil_port_stats_from_ofp11(ps, ps11);
      } else if (raw == OFPRAW_OFPST10_PORT_REPLY) {
          const struct ofp10_port_stats *ps10;
  
          ps10 = ofpbuf_try_pull(msg, sizeof *ps10);
          if (!ps10) {
              goto bad_len;
          }
          return ofputil_port_stats_from_ofp10(ps, ps10);
      } else {
          OVS_NOT_REACHED();
      }
  
   bad_len:
      VLOG_WARN_RL(&bad_ofmsg_rl, "OFPST_PORT reply has %"PRIu32" leftover "
                   "bytes at end", msg->size);
      return OFPERR_OFPBRC_BAD_LEN;
  }
  
  /* Parse a port status request message into a 16 bit OpenFlow 1.0
   * port number and stores the latter in '*ofp10_port'.
   * Returns 0 if successful, otherwise an OFPERR_* number. */
  enum ofperr
  ofputil_decode_port_stats_request(const struct ofp_header *request,
                                    ofp_port_t *ofp10_port)
  {
      switch ((enum ofp_version)request->version) {
      case OFP15_VERSION:
      case OFP14_VERSION:
      case OFP13_VERSION:
      case OFP12_VERSION:
      case OFP11_VERSION: {
          const struct ofp11_port_stats_request *psr11 = ofpmsg_body(request);
          return ofputil_port_from_ofp11(psr11->port_no, ofp10_port);
      }
  
      case OFP10_VERSION: {
          const struct ofp10_port_stats_request *psr10 = ofpmsg_body(request);
          *ofp10_port = u16_to_ofp(ntohs(psr10->port_no));
          return 0;
      }
  
      default:
          OVS_NOT_REACHED();
      }
  }
  
  /* Frees all of the "struct ofputil_bucket"s in the 'buckets' list. */
  void
  ofputil_bucket_list_destroy(struct ovs_list *buckets)
  {
      struct ofputil_bucket *bucket;
  
      LIST_FOR_EACH_POP (bucket, list_node, buckets) {
          free(bucket->ofpacts);
          free(bucket);
      }
  }
  
  /* Clones 'bucket' and its ofpacts data */
  static struct ofputil_bucket *
  ofputil_bucket_clone_data(const struct ofputil_bucket *bucket)
  {
      struct ofputil_bucket *new;
  
      new = xmemdup(bucket, sizeof *bucket);
      new->ofpacts = xmemdup(bucket->ofpacts, bucket->ofpacts_len);
  
      return new;
  }
  
  /* Clones each of the buckets in the list 'src' appending them
   * in turn to 'dest' which should be an initialised list.
   * An exception is that if the pointer value of a bucket in 'src'
   * matches 'skip' then it is not cloned or appended to 'dest'.
   * This allows all of 'src' or 'all of 'src' except 'skip' to
   * be cloned and appended to 'dest'. */
  void
  ofputil_bucket_clone_list(struct ovs_list *dest, const struct ovs_list *src,
                            const struct ofputil_bucket *skip)
  {
      struct ofputil_bucket *bucket;
  
      LIST_FOR_EACH (bucket, list_node, src) {
          struct ofputil_bucket *new_bucket;
  
          if (bucket == skip) {
              continue;
          }
  
          new_bucket = ofputil_bucket_clone_data(bucket);
          list_push_back(dest, &new_bucket->list_node);
      }
  }
  
  /* Find a bucket in the list 'buckets' whose bucket id is 'bucket_id'
   * Returns the first bucket found or NULL if no buckets are found. */
  struct ofputil_bucket *
  ofputil_bucket_find(const struct ovs_list *buckets, uint32_t bucket_id)
  {
      struct ofputil_bucket *bucket;
  
      if (bucket_id > OFPG15_BUCKET_MAX) {
          return NULL;
      }
  
      LIST_FOR_EACH (bucket, list_node, buckets) {
          if (bucket->bucket_id == bucket_id) {
              return bucket;
          }
      }
  
      return NULL;
  }
  
  /* Returns true if more than one bucket in the list 'buckets'
   * have the same bucket id. Returns false otherwise. */
  bool
  ofputil_bucket_check_duplicate_id(const struct ovs_list *buckets)
  {
      struct ofputil_bucket *i, *j;
  
      LIST_FOR_EACH (i, list_node, buckets) {
          LIST_FOR_EACH_REVERSE (j, list_node, buckets) {
              if (i == j) {
                  break;
              }
              if (i->bucket_id == j->bucket_id) {
                  return true;
              }
          }
      }
  
      return false;
  }
  
  /* Returns the bucket at the front of the list 'buckets'.
   * Undefined if 'buckets is empty. */
  struct ofputil_bucket *
  ofputil_bucket_list_front(const struct ovs_list *buckets)
  {
      static struct ofputil_bucket *bucket;
  
      ASSIGN_CONTAINER(bucket, list_front(buckets), list_node);
  
      return bucket;
  }
  
  /* Returns the bucket at the back of the list 'buckets'.
   * Undefined if 'buckets is empty. */
  struct ofputil_bucket *
  ofputil_bucket_list_back(const struct ovs_list *buckets)
  {
      static struct ofputil_bucket *bucket;
  
      ASSIGN_CONTAINER(bucket, list_back(buckets), list_node);
  
      return bucket;
  }
  
  /* Returns an OpenFlow group stats request for OpenFlow version 'ofp_version',
   * that requests stats for group 'group_id'.  (Use OFPG_ALL to request stats
   * for all groups.)
   *
   * Group statistics include packet and byte counts for each group. */
  struct ofpbuf *
  ofputil_encode_group_stats_request(enum ofp_version ofp_version,
                                     uint32_t group_id)
  {
      struct ofpbuf *request;
  
      switch (ofp_version) {
      case OFP10_VERSION:
          ovs_fatal(0, "dump-group-stats needs OpenFlow 1.1 or later "
                       "(\'-O OpenFlow11\')");
      case OFP11_VERSION:
      case OFP12_VERSION:
      case OFP13_VERSION:
      case OFP14_VERSION:
      case OFP15_VERSION: {
          struct ofp11_group_stats_request *req;
          request = ofpraw_alloc(OFPRAW_OFPST11_GROUP_REQUEST, ofp_version, 0);
          req = ofpbuf_put_zeros(request, sizeof *req);
          req->group_id = htonl(group_id);
          break;
      }
      default:
          OVS_NOT_REACHED();
      }
  
      return request;
  }
  
  void
  ofputil_uninit_group_desc(struct ofputil_group_desc *gd)
  {
      ofputil_bucket_list_destroy(&gd->buckets);
      free(&gd->props.fields);
  }
  
  /* Decodes the OpenFlow group description request in 'oh', returning the group
   * whose description is requested, or OFPG_ALL if stats for all groups was
   * requested. */
  uint32_t
  ofputil_decode_group_desc_request(const struct ofp_header *oh)
  {
      struct ofpbuf request;
      enum ofpraw raw;
  
      ofpbuf_use_const(&request, oh, ntohs(oh->length));
      raw = ofpraw_pull_assert(&request);
      if (raw == OFPRAW_OFPST11_GROUP_DESC_REQUEST) {
          return OFPG_ALL;
      } else if (raw == OFPRAW_OFPST15_GROUP_DESC_REQUEST) {
          ovs_be32 *group_id = ofpbuf_pull(&request, sizeof *group_id);
          return ntohl(*group_id);
      } else {
          OVS_NOT_REACHED();
      }
  }
  
  /* Returns an OpenFlow group description request for OpenFlow version
   * 'ofp_version', that requests stats for group 'group_id'.  Use OFPG_ALL to
   * request stats for all groups (OpenFlow 1.4 and earlier always request all
   * groups).
   *
   * Group descriptions include the bucket and action configuration for each
   * group. */
  struct ofpbuf *
  ofputil_encode_group_desc_request(enum ofp_version ofp_version,
                                    uint32_t group_id)
  {
      struct ofpbuf *request;
      ovs_be32 gid;
  
      switch (ofp_version) {
      case OFP10_VERSION:
          ovs_fatal(0, "dump-groups needs OpenFlow 1.1 or later "
                       "(\'-O OpenFlow11\')");
      case OFP11_VERSION:
      case OFP12_VERSION:
      case OFP13_VERSION:
      case OFP14_VERSION:
          request = ofpraw_alloc(OFPRAW_OFPST11_GROUP_DESC_REQUEST,
                                 ofp_version, 0);
          break;
      case OFP15_VERSION:
          request = ofpraw_alloc(OFPRAW_OFPST15_GROUP_DESC_REQUEST,
                                 ofp_version, 0);
          gid = htonl(group_id);
          ofpbuf_put(request, &gid, sizeof gid);
          break;
      default:
          OVS_NOT_REACHED();
      }
  
      return request;
  }
  
  static void
  ofputil_group_bucket_counters_to_ofp11(const struct ofputil_group_stats *gs,
                                      struct ofp11_bucket_counter bucket_cnts[])
  {
      int i;
  
      for (i = 0; i < gs->n_buckets; i++) {
         bucket_cnts[i].packet_count = htonll(gs->bucket_stats[i].packet_count);
         bucket_cnts[i].byte_count = htonll(gs->bucket_stats[i].byte_count);
      }
  }
  
  static void
  ofputil_group_stats_to_ofp11(const struct ofputil_group_stats *gs,
                               struct ofp11_group_stats *gs11, size_t length,
                               struct ofp11_bucket_counter bucket_cnts[])
  {
      memset(gs11, 0, sizeof *gs11);
      gs11->length = htons(length);
      gs11->group_id = htonl(gs->group_id);
      gs11->ref_count = htonl(gs->ref_count);
      gs11->packet_count = htonll(gs->packet_count);
      gs11->byte_count = htonll(gs->byte_count);
      ofputil_group_bucket_counters_to_ofp11(gs, bucket_cnts);
  }
  
  static void
  ofputil_group_stats_to_ofp13(const struct ofputil_group_stats *gs,
                               struct ofp13_group_stats *gs13, size_t length,
                               struct ofp11_bucket_counter bucket_cnts[])
  {
      ofputil_group_stats_to_ofp11(gs, &gs13->gs, length, bucket_cnts);
      gs13->duration_sec = htonl(gs->duration_sec);
      gs13->duration_nsec = htonl(gs->duration_nsec);
  
  }
  
  /* Encodes 'gs' properly for the format of the list of group statistics
   * replies already begun in 'replies' and appends it to the list.  'replies'
   * must have originally been initialized with ofpmp_init(). */
  void
  ofputil_append_group_stats(struct ovs_list *replies,
                             const struct ofputil_group_stats *gs)
  {
      size_t bucket_counter_size;
      struct ofp11_bucket_counter *bucket_counters;
      size_t length;
  
      bucket_counter_size = gs->n_buckets * sizeof(struct ofp11_bucket_counter);
  
      switch (ofpmp_version(replies)) {
      case OFP11_VERSION:
      case OFP12_VERSION:{
              struct ofp11_group_stats *gs11;
  
              length = sizeof *gs11 + bucket_counter_size;
              gs11 = ofpmp_append(replies, length);
              bucket_counters = (struct ofp11_bucket_counter *)(gs11 + 1);
              ofputil_group_stats_to_ofp11(gs, gs11, length, bucket_counters);
              break;
          }
  
      case OFP13_VERSION:
      case OFP14_VERSION:
      case OFP15_VERSION: {
              struct ofp13_group_stats *gs13;
  
              length = sizeof *gs13 + bucket_counter_size;
              gs13 = ofpmp_append(replies, length);
              bucket_counters = (struct ofp11_bucket_counter *)(gs13 + 1);
              ofputil_group_stats_to_ofp13(gs, gs13, length, bucket_counters);
              break;
          }
  
      case OFP10_VERSION:
      default:
          OVS_NOT_REACHED();
      }
  }
  /* Returns an OpenFlow group features request for OpenFlow version
   * 'ofp_version'. */
  struct ofpbuf *
  ofputil_encode_group_features_request(enum ofp_version ofp_version)
  {
      struct ofpbuf *request = NULL;
  
      switch (ofp_version) {
      case OFP10_VERSION:
      case OFP11_VERSION:
          ovs_fatal(0, "dump-group-features needs OpenFlow 1.2 or later "
                       "(\'-O OpenFlow12\')");
      case OFP12_VERSION:
      case OFP13_VERSION:
      case OFP14_VERSION:
      case OFP15_VERSION:
          request = ofpraw_alloc(OFPRAW_OFPST12_GROUP_FEATURES_REQUEST,
                                 ofp_version, 0);
          break;
      default:
          OVS_NOT_REACHED();
      }
  
      return request;
  }
  
  /* Returns a OpenFlow message that encodes 'features' properly as a reply to
   * group features request 'request'. */
  struct ofpbuf *
  ofputil_encode_group_features_reply(
      const struct ofputil_group_features *features,
      const struct ofp_header *request)
  {
      struct ofp12_group_features_stats *ogf;
      struct ofpbuf *reply;
      int i;
  
      reply = ofpraw_alloc_xid(OFPRAW_OFPST12_GROUP_FEATURES_REPLY,
                               request->version, request->xid, 0);
      ogf = ofpbuf_put_zeros(reply, sizeof *ogf);
      ogf->types = htonl(features->types);
      ogf->capabilities = htonl(features->capabilities);
      for (i = 0; i < OFPGT12_N_TYPES; i++) {
          ogf->max_groups[i] = htonl(features->max_groups[i]);
          ogf->actions[i] = ofpact_bitmap_to_openflow(features->ofpacts[i],
                                                      request->version);
      }
  
      return reply;
  }
  
  /* Decodes group features reply 'oh' into 'features'. */
  void
  ofputil_decode_group_features_reply(const struct ofp_header *oh,
                                      struct ofputil_group_features *features)
  {
      const struct ofp12_group_features_stats *ogf = ofpmsg_body(oh);
      int i;
  
      features->types = ntohl(ogf->types);
      features->capabilities = ntohl(ogf->capabilities);
      for (i = 0; i < OFPGT12_N_TYPES; i++) {
          features->max_groups[i] = ntohl(ogf->max_groups[i]);
          features->ofpacts[i] = ofpact_bitmap_from_openflow(
              ogf->actions[i], oh->version);
      }
  }
  
  /* Parse a group status request message into a 32 bit OpenFlow 1.1
   * group ID and stores the latter in '*group_id'.
   * Returns 0 if successful, otherwise an OFPERR_* number. */
  enum ofperr
  ofputil_decode_group_stats_request(const struct ofp_header *request,
                                     uint32_t *group_id)
  {
      const struct ofp11_group_stats_request *gsr11 = ofpmsg_body(request);
      *group_id = ntohl(gsr11->group_id);
      return 0;
  }
  
  /* Converts a group stats reply in 'msg' into an abstract ofputil_group_stats
   * in 'gs'.  Assigns freshly allocated memory to gs->bucket_stats for the
   * caller to eventually free.
   *
   * Multiple group stats replies can be packed into a single OpenFlow message.
   * Calling this function multiple times for a single 'msg' iterates through the
   * replies.  The caller must initially leave 'msg''s layer pointers null and
   * not modify them between calls.
   *
   * Returns 0 if successful, EOF if no replies were left in this 'msg',
   * otherwise a positive errno value. */
  int
  ofputil_decode_group_stats_reply(struct ofpbuf *msg,
                                   struct ofputil_group_stats *gs)
  {
      struct ofp11_bucket_counter *obc;
      struct ofp11_group_stats *ogs11;
      enum ofpraw raw;
      enum ofperr error;
      size_t base_len;
      size_t length;
      size_t i;
  
      gs->bucket_stats = NULL;
      error = (msg->header ? ofpraw_decode(&raw, msg->header)
               : ofpraw_pull(&raw, msg));
      if (error) {
          return error;
      }
  
      if (!msg->size) {
          return EOF;
      }
  
      if (raw == OFPRAW_OFPST11_GROUP_REPLY) {
          base_len = sizeof *ogs11;
          ogs11 = ofpbuf_try_pull(msg, sizeof *ogs11);
          gs->duration_sec = gs->duration_nsec = UINT32_MAX;
      } else if (raw == OFPRAW_OFPST13_GROUP_REPLY) {
          struct ofp13_group_stats *ogs13;
  
          base_len = sizeof *ogs13;
          ogs13 = ofpbuf_try_pull(msg, sizeof *ogs13);
          if (ogs13) {
              ogs11 = &ogs13->gs;
              gs->duration_sec = ntohl(ogs13->duration_sec);
              gs->duration_nsec = ntohl(ogs13->duration_nsec);
          } else {
              ogs11 = NULL;
          }
      } else {
          OVS_NOT_REACHED();
      }
  
      if (!ogs11) {
          VLOG_WARN_RL(&bad_ofmsg_rl, "%s reply has %"PRIu32" leftover bytes at end",
                       ofpraw_get_name(raw), msg->size);
          return OFPERR_OFPBRC_BAD_LEN;
      }
      length = ntohs(ogs11->length);
      if (length < sizeof base_len) {
          VLOG_WARN_RL(&bad_ofmsg_rl, "%s reply claims invalid length %"PRIuSIZE,
                       ofpraw_get_name(raw), length);
          return OFPERR_OFPBRC_BAD_LEN;
      }
  
      gs->group_id = ntohl(ogs11->group_id);
      gs->ref_count = ntohl(ogs11->ref_count);
      gs->packet_count = ntohll(ogs11->packet_count);
      gs->byte_count = ntohll(ogs11->byte_count);
  
      gs->n_buckets = (length - base_len) / sizeof *obc;
      obc = ofpbuf_try_pull(msg, gs->n_buckets * sizeof *obc);
      if (!obc) {
          VLOG_WARN_RL(&bad_ofmsg_rl, "%s reply has %"PRIu32" leftover bytes at end",
                       ofpraw_get_name(raw), msg->size);
          return OFPERR_OFPBRC_BAD_LEN;
      }
  
      gs->bucket_stats = xmalloc(gs->n_buckets * sizeof *gs->bucket_stats);
      for (i = 0; i < gs->n_buckets; i++) {
          gs->bucket_stats[i].packet_count = ntohll(obc[i].packet_count);
          gs->bucket_stats[i].byte_count = ntohll(obc[i].byte_count);
      }
  
      return 0;
  }
  
  static void
  ofputil_put_ofp11_bucket(const struct ofputil_bucket *bucket,
                           struct ofpbuf *openflow, enum ofp_version ofp_version)
  {
      struct ofp11_bucket *ob;
      size_t start;
  
      start = openflow->size;
      ofpbuf_put_zeros(openflow, sizeof *ob);
      ofpacts_put_openflow_actions(bucket->ofpacts, bucket->ofpacts_len,
                                  openflow, ofp_version);
      ob = ofpbuf_at_assert(openflow, start, sizeof *ob);
      ob->len = htons(openflow->size - start);
      ob->weight = htons(bucket->weight);
      ob->watch_port = ofputil_port_to_ofp11(bucket->watch_port);
      ob->watch_group = htonl(bucket->watch_group);
  }
  
  static void
  ofputil_put_ofp15_group_bucket_prop_weight(ovs_be16 weight,
                                             struct ofpbuf *openflow)
  {
      size_t start_ofs;
      struct ofp15_group_bucket_prop_weight *prop;
  
      start_ofs = start_property(openflow, OFPGBPT15_WEIGHT);
      ofpbuf_put_zeros(openflow, sizeof *prop - sizeof(struct ofp_prop_header));
      prop = ofpbuf_at_assert(openflow, start_ofs, sizeof *prop);
      prop->weight = weight;
      end_property(openflow, start_ofs);
  }
  
  static void
  ofputil_put_ofp15_group_bucket_prop_watch(ovs_be32 watch, uint16_t type,
                                            struct ofpbuf *openflow)
  {
      size_t start_ofs;
      struct ofp15_group_bucket_prop_watch *prop;
  
      start_ofs = start_property(openflow, type);
      ofpbuf_put_zeros(openflow, sizeof *prop - sizeof(struct ofp_prop_header));
      prop = ofpbuf_at_assert(openflow, start_ofs, sizeof *prop);
      prop->watch = watch;
      end_property(openflow, start_ofs);
  }
  
  static void
  ofputil_put_ofp15_bucket(const struct ofputil_bucket *bucket,
                           uint32_t bucket_id, enum ofp11_group_type group_type,
                           struct ofpbuf *openflow, enum ofp_version ofp_version)
  {
      struct ofp15_bucket *ob;
      size_t start, actions_start, actions_len;
  
      start = openflow->size;
      ofpbuf_put_zeros(openflow, sizeof *ob);
  
      actions_start = openflow->size;
      ofpacts_put_openflow_actions(bucket->ofpacts, bucket->ofpacts_len,
                                   openflow, ofp_version);
      actions_len = openflow->size - actions_start;
  
      if (group_type == OFPGT11_SELECT) {
          ofputil_put_ofp15_group_bucket_prop_weight(htons(bucket->weight),
                                                     openflow);
      }
      if (bucket->watch_port != OFPP_ANY) {
          ovs_be32 port = ofputil_port_to_ofp11(bucket->watch_port);
          ofputil_put_ofp15_group_bucket_prop_watch(port,
                                                    OFPGBPT15_WATCH_PORT,
                                                    openflow);
      }
      if (bucket->watch_group != OFPG_ANY) {
          ovs_be32 group = htonl(bucket->watch_group);
          ofputil_put_ofp15_group_bucket_prop_watch(group,
                                                    OFPGBPT15_WATCH_GROUP,
                                                    openflow);
      }
  
      ob = ofpbuf_at_assert(openflow, start, sizeof *ob);
      ob->len = htons(openflow->size - start);
      ob->action_array_len = htons(actions_len);
      ob->bucket_id = htonl(bucket_id);
  }
  
  static void
  ofputil_put_group_prop_ntr_selection_method(enum ofp_version ofp_version,
                                              const struct ofputil_group_props *gp,
                                              struct ofpbuf *openflow)
  {
      struct ntr_group_prop_selection_method *prop;
      size_t start;
  
      start = openflow->size;
      ofpbuf_put_zeros(openflow, sizeof *prop);
      oxm_put_field_array(openflow, &gp->fields, ofp_version);
      prop = ofpbuf_at_assert(openflow, start, sizeof *prop);
      prop->type = htons(OFPGPT15_EXPERIMENTER);
      prop->experimenter = htonl(NTR_VENDOR_ID);
      prop->exp_type = htonl(NTRT_SELECTION_METHOD);
      strcpy(prop->selection_method, gp->selection_method);
      prop->selection_method_param = htonll(gp->selection_method_param);
      end_property(openflow, start);
  }
  
  static void
  ofputil_append_ofp11_group_desc_reply(const struct ofputil_group_desc *gds,
                                        const struct ovs_list *buckets,
                                        struct ovs_list *replies,
                                        enum ofp_version version)
  {
      struct ofpbuf *reply = ofpbuf_from_list(list_back(replies));
      struct ofp11_group_desc_stats *ogds;
      struct ofputil_bucket *bucket;
      size_t start_ogds;
  
      start_ogds = reply->size;
      ofpbuf_put_zeros(reply, sizeof *ogds);
      LIST_FOR_EACH (bucket, list_node, buckets) {
          ofputil_put_ofp11_bucket(bucket, reply, version);
      }
      ogds = ofpbuf_at_assert(reply, start_ogds, sizeof *ogds);
      ogds->length = htons(reply->size - start_ogds);
      ogds->type = gds->type;
      ogds->group_id = htonl(gds->group_id);
  
      ofpmp_postappend(replies, start_ogds);
  }
  
  static void
  ofputil_append_ofp15_group_desc_reply(const struct ofputil_group_desc *gds,
                                        const struct ovs_list *buckets,
                                        struct ovs_list *replies,
                                        enum ofp_version version)
  {
      struct ofpbuf *reply = ofpbuf_from_list(list_back(replies));
      struct ofp15_group_desc_stats *ogds;
      struct ofputil_bucket *bucket;
      size_t start_ogds, start_buckets;
  
      start_ogds = reply->size;
      ofpbuf_put_zeros(reply, sizeof *ogds);
      start_buckets = reply->size;
      LIST_FOR_EACH (bucket, list_node, buckets) {
          ofputil_put_ofp15_bucket(bucket, bucket->bucket_id,
                                   gds->type, reply, version);
      }
      ogds = ofpbuf_at_assert(reply, start_ogds, sizeof *ogds);
      ogds->length = htons(reply->size - start_ogds);
      ogds->type = gds->type;
      ogds->group_id = htonl(gds->group_id);
      ogds->bucket_list_len =  htons(reply->size - start_buckets);
  
      /* Add group properties */
      if (gds->props.selection_method[0]) {
          ofputil_put_group_prop_ntr_selection_method(version, &gds->props,
                                                      reply);
      }
  
      ofpmp_postappend(replies, start_ogds);
  }
  
  /* Appends a group stats reply that contains the data in 'gds' to those already
   * present in the list of ofpbufs in 'replies'.  'replies' should have been
   * initialized with ofpmp_init(). */
  void
  ofputil_append_group_desc_reply(const struct ofputil_group_desc *gds,
                                  const struct ovs_list *buckets,
                                  struct ovs_list *replies)
  {
      enum ofp_version version = ofpmp_version(replies);
  
      switch (version)
      {
      case OFP11_VERSION:
      case OFP12_VERSION:
      case OFP13_VERSION:
      case OFP14_VERSION:
          ofputil_append_ofp11_group_desc_reply(gds, buckets, replies, version);
          break;
  
      case OFP15_VERSION:
          ofputil_append_ofp15_group_desc_reply(gds, buckets, replies, version);
          break;
  
      case OFP10_VERSION:
      default:
          OVS_NOT_REACHED();
      }
  }
  
  static enum ofperr
  ofputil_pull_ofp11_buckets(struct ofpbuf *msg, size_t buckets_length,
                             enum ofp_version version, struct ovs_list *buckets)
  {
      struct ofp11_bucket *ob;
      uint32_t bucket_id = 0;
  
      list_init(buckets);
      while (buckets_length > 0) {
          struct ofputil_bucket *bucket;
          struct ofpbuf ofpacts;
          enum ofperr error;
          size_t ob_len;
  
          ob = (buckets_length >= sizeof *ob
                ? ofpbuf_try_pull(msg, sizeof *ob)
                : NULL);
          if (!ob) {
              VLOG_WARN_RL(&bad_ofmsg_rl, "buckets end with %"PRIuSIZE" leftover bytes",
                           buckets_length);
              return OFPERR_OFPGMFC_BAD_BUCKET;
          }
  
          ob_len = ntohs(ob->len);
          if (ob_len < sizeof *ob) {
              VLOG_WARN_RL(&bad_ofmsg_rl, "OpenFlow message bucket length "
                           "%"PRIuSIZE" is not valid", ob_len);
              return OFPERR_OFPGMFC_BAD_BUCKET;
          } else if (ob_len > buckets_length) {
              VLOG_WARN_RL(&bad_ofmsg_rl, "OpenFlow message bucket length "
                           "%"PRIuSIZE" exceeds remaining buckets data size %"PRIuSIZE,
                           ob_len, buckets_length);
              return OFPERR_OFPGMFC_BAD_BUCKET;
          }
          buckets_length -= ob_len;
  
          ofpbuf_init(&ofpacts, 0);
          error = ofpacts_pull_openflow_actions(msg, ob_len - sizeof *ob,
                                                version, &ofpacts);
          if (error) {
              ofpbuf_uninit(&ofpacts);
              ofputil_bucket_list_destroy(buckets);
              return error;
          }
  
          bucket = xzalloc(sizeof *bucket);
          bucket->weight = ntohs(ob->weight);
          error = ofputil_port_from_ofp11(ob->watch_port, &bucket->watch_port);
          if (error) {
              ofpbuf_uninit(&ofpacts);
              ofputil_bucket_list_destroy(buckets);
              return OFPERR_OFPGMFC_BAD_WATCH;
          }
          bucket->watch_group = ntohl(ob->watch_group);
          bucket->bucket_id = bucket_id++;
  
          bucket->ofpacts = ofpbuf_steal_data(&ofpacts);
          bucket->ofpacts_len = ofpacts.size;
          list_push_back(buckets, &bucket->list_node);
      }
  
      return 0;
  }
  
  static enum ofperr
  parse_ofp15_group_bucket_prop_weight(const struct ofpbuf *payload,
                                       ovs_be16 *weight)
  {
      struct ofp15_group_bucket_prop_weight *prop = payload->data;
  
      if (payload->size != sizeof *prop) {
          log_property(false, "OpenFlow bucket weight property length "
                       "%u is not valid", payload->size);
          return OFPERR_OFPBPC_BAD_LEN;
      }
  
      *weight = prop->weight;
  
      return 0;
  }
  
  static enum ofperr
  parse_ofp15_group_bucket_prop_watch(const struct ofpbuf *payload,
                                      ovs_be32 *watch)
  {
      struct ofp15_group_bucket_prop_watch *prop = payload->data;
  
      if (payload->size != sizeof *prop) {
          log_property(false, "OpenFlow bucket watch port or group "
                       "property length %u is not valid", payload->size);
          return OFPERR_OFPBPC_BAD_LEN;
      }
  
      *watch = prop->watch;
  
      return 0;
  }
  
  static enum ofperr
  ofputil_pull_ofp15_buckets(struct ofpbuf *msg, size_t buckets_length,
                             enum ofp_version version, struct ovs_list *buckets)
  {
      struct ofp15_bucket *ob;
  
      list_init(buckets);
      while (buckets_length > 0) {
          struct ofputil_bucket *bucket = NULL;
          struct ofpbuf ofpacts;
          enum ofperr err = OFPERR_OFPGMFC_BAD_BUCKET;
          struct ofpbuf properties;
          size_t ob_len, actions_len, properties_len;
          ovs_be32 watch_port = ofputil_port_to_ofp11(OFPP_ANY);
          ovs_be32 watch_group = htonl(OFPG_ANY);
          ovs_be16 weight = htons(1);
  
          ofpbuf_init(&ofpacts, 0);
  
          ob = ofpbuf_try_pull(msg, sizeof *ob);
          if (!ob) {
              VLOG_WARN_RL(&bad_ofmsg_rl, "buckets end with %"PRIuSIZE
                           " leftover bytes", buckets_length);
              goto err;
          }
  
          ob_len = ntohs(ob->len);
          actions_len = ntohs(ob->action_array_len);
  
          if (ob_len < sizeof *ob) {
              VLOG_WARN_RL(&bad_ofmsg_rl, "OpenFlow message bucket length "
                           "%"PRIuSIZE" is not valid", ob_len);
              goto err;
          } else if (ob_len > buckets_length) {
              VLOG_WARN_RL(&bad_ofmsg_rl, "OpenFlow message bucket length "
                           "%"PRIuSIZE" exceeds remaining buckets data size %"
                           PRIuSIZE, ob_len, buckets_length);
              goto err;
          } else if (actions_len > ob_len - sizeof *ob) {
              VLOG_WARN_RL(&bad_ofmsg_rl, "OpenFlow message bucket actions "
                           "length %"PRIuSIZE" exceeds remaining bucket "
                           "data size %"PRIuSIZE, actions_len,
                           ob_len - sizeof *ob);
              goto err;
          }
          buckets_length -= ob_len;
  
          err = ofpacts_pull_openflow_actions(msg, actions_len, version,
                                              &ofpacts);
          if (err) {
              goto err;
          }
  
          properties_len = ob_len - sizeof *ob - actions_len;
          ofpbuf_use_const(&properties, ofpbuf_pull(msg, properties_len),
                           properties_len);
  
          while (properties.size > 0) {
              struct ofpbuf payload;
              uint16_t type;
  
              err = ofputil_pull_property(&properties, &payload, &type);
              if (err) {
                  goto err;
              }
  
              switch (type) {
              case OFPGBPT15_WEIGHT:
                  err = parse_ofp15_group_bucket_prop_weight(&payload, &weight);
                  break;
  
              case OFPGBPT15_WATCH_PORT:
                  err = parse_ofp15_group_bucket_prop_watch(&payload,
                                                            &watch_port);
                  break;
  
              case OFPGBPT15_WATCH_GROUP:
                  err = parse_ofp15_group_bucket_prop_watch(&payload,
                                                            &watch_group);
                  break;
  
              default:
                  log_property(false, "unknown group bucket property %"PRIu16,
                               type);
                  err = OFPERR_OFPBPC_BAD_TYPE;
                  break;
              }
  
              if (err) {
                  goto err;
              }
          }
  
          bucket = xzalloc(sizeof *bucket);
  
          bucket->weight = ntohs(weight);
          err = ofputil_port_from_ofp11(watch_port, &bucket->watch_port);
          if (err) {
              err = OFPERR_OFPGMFC_BAD_WATCH;
              goto err;
          }
          bucket->watch_group = ntohl(watch_group);
          bucket->bucket_id = ntohl(ob->bucket_id);
          if (bucket->bucket_id > OFPG15_BUCKET_MAX) {
              VLOG_WARN_RL(&bad_ofmsg_rl, "bucket id (%u) is out of range",
                           bucket->bucket_id);
              err = OFPERR_OFPGMFC_BAD_BUCKET;
              goto err;
          }
  
          bucket->ofpacts = ofpbuf_steal_data(&ofpacts);
          bucket->ofpacts_len = ofpacts.size;
          list_push_back(buckets, &bucket->list_node);
  
          continue;
  
      err:
          free(bucket);
          ofpbuf_uninit(&ofpacts);
          ofputil_bucket_list_destroy(buckets);
          return err;
      }
  
      if (ofputil_bucket_check_duplicate_id(buckets)) {
          VLOG_WARN_RL(&bad_ofmsg_rl, "Duplicate bucket id");
          ofputil_bucket_list_destroy(buckets);
          return OFPERR_OFPGMFC_BAD_BUCKET;
      }
  
      return 0;
  }
  
  static void
  ofputil_init_group_properties(struct ofputil_group_props *gp)
  {
      memset(gp, 0, sizeof *gp);
  }
  
  static enum ofperr
  parse_group_prop_ntr_selection_method(struct ofpbuf *payload,
                                        enum ofp11_group_type group_type,
                                        enum ofp15_group_mod_command group_cmd,
                                        struct ofputil_group_props *gp)
  {
      struct ntr_group_prop_selection_method *prop = payload->data;
      size_t fields_len, method_len;
      enum ofperr error;
  
      switch (group_type) {
      case OFPGT11_SELECT:
          break;
      case OFPGT11_ALL:
      case OFPGT11_INDIRECT:
      case OFPGT11_FF:
          log_property(false, "ntr selection method property is only allowed "
                       "for select groups");
          return OFPERR_OFPBPC_BAD_VALUE;
      default:
          OVS_NOT_REACHED();
      }
  
      switch (group_cmd) {
      case OFPGC15_ADD:
      case OFPGC15_MODIFY:
          break;
      case OFPGC15_DELETE:
      case OFPGC15_INSERT_BUCKET:
      case OFPGC15_REMOVE_BUCKET:
          log_property(false, "ntr selection method property is only allowed "
                       "for add and delete group modifications");
          return OFPERR_OFPBPC_BAD_VALUE;
      default:
          OVS_NOT_REACHED();
      }
  
      if (payload->size < sizeof *prop) {
          log_property(false, "ntr selection method property length "
                       "%u is not valid", payload->size);
          return OFPERR_OFPBPC_BAD_LEN;
      }
  
      method_len = strnlen(prop->selection_method, NTR_MAX_SELECTION_METHOD_LEN);
  
      if (method_len == NTR_MAX_SELECTION_METHOD_LEN) {
          log_property(false, "ntr selection method is not null terminated");
          return OFPERR_OFPBPC_BAD_VALUE;
      }
  
      if (strcmp("hash", prop->selection_method)) {
          log_property(false, "ntr selection method '%s' is not supported",
                       prop->selection_method);
          return OFPERR_OFPBPC_BAD_VALUE;
      }
  
      strcpy(gp->selection_method, prop->selection_method);
      gp->selection_method_param = ntohll(prop->selection_method_param);
  
      if (!method_len && gp->selection_method_param) {
          log_property(false, "ntr selection method parameter is non-zero but "
                       "selection method is empty");
          return OFPERR_OFPBPC_BAD_VALUE;
      }
  
      ofpbuf_pull(payload, sizeof *prop);
  
      fields_len = ntohs(prop->length) - sizeof *prop;
      if (!method_len && fields_len) {
          log_property(false, "ntr selection method parameter is zero "
                       "but fields are provided");
          return OFPERR_OFPBPC_BAD_VALUE;
      }
  
      error = oxm_pull_field_array(payload->data, fields_len,
                                   &gp->fields);
      if (error) {
          log_property(false, "ntr selection method fields are invalid");
          return error;
      }
  
      return 0;
  }
  
  static enum ofperr
  parse_group_prop_ntr(struct ofpbuf *payload, uint32_t exp_type,
                       enum ofp11_group_type group_type,
                       enum ofp15_group_mod_command group_cmd,
                       struct ofputil_group_props *gp)
  {
      enum ofperr error;
  
      switch (exp_type) {
      case NTRT_SELECTION_METHOD:
          error = parse_group_prop_ntr_selection_method(payload, group_type,
                                                        group_cmd, gp);
          break;
  
      default:
          log_property(false, "unknown group property ntr experimenter type "
                       "%"PRIu32, exp_type);
          error = OFPERR_OFPBPC_BAD_TYPE;
          break;
      }
  
      return error;
  }
  
  static enum ofperr
  parse_ofp15_group_prop_exp(struct ofpbuf *payload,
                             enum ofp11_group_type group_type,
                             enum ofp15_group_mod_command group_cmd,
                             struct ofputil_group_props *gp)
  {
      struct ofp_prop_experimenter *prop = payload->data;
      uint16_t experimenter;
      uint32_t exp_type;
      enum ofperr error;
  
      if (payload->size < sizeof *prop) {
          return OFPERR_OFPBPC_BAD_LEN;
      }
  
      experimenter = ntohl(prop->experimenter);
      exp_type = ntohl(prop->exp_type);
  
      switch (experimenter) {
      case NTR_VENDOR_ID:
          error = parse_group_prop_ntr(payload, exp_type, group_type,
                                       group_cmd, gp);
          break;
  
      default:
          log_property(false, "unknown group property experimenter %"PRIu16,
                       experimenter);
          error = OFPERR_OFPBPC_BAD_EXPERIMENTER;
          break;
      }
  
      return error;
  }
  
  static enum ofperr
  parse_ofp15_group_properties(struct ofpbuf *msg,
                               enum ofp11_group_type group_type,
                               enum ofp15_group_mod_command group_cmd,
                               struct ofputil_group_props *gp,
                               size_t properties_len)
  {
      struct ofpbuf properties;
  
      ofpbuf_use_const(&properties, ofpbuf_pull(msg, properties_len),
                       properties_len);
  
      while (properties.size > 0) {
          struct ofpbuf payload;
          enum ofperr error;
          uint16_t type;
  
          error = ofputil_pull_property(&properties, &payload, &type);
          if (error) {
              return error;
          }
  
          switch (type) {
          case OFPGPT15_EXPERIMENTER:
              error = parse_ofp15_group_prop_exp(&payload, group_type,
                                                 group_cmd, gp);
              break;
  
          default:
              log_property(false, "unknown group property %"PRIu16, type);
              error = OFPERR_OFPBPC_BAD_TYPE;
              break;
          }
  
          if (error) {
              return error;
          }
      }
  
      return 0;
  }
  
  static int
  ofputil_decode_ofp11_group_desc_reply(struct ofputil_group_desc *gd,
                                        struct ofpbuf *msg,
                                        enum ofp_version version)
  {
      struct ofp11_group_desc_stats *ogds;
      size_t length;
  
      if (!msg->header) {
          ofpraw_pull_assert(msg);
      }
  
      if (!msg->size) {
          return EOF;
      }
  
      ogds = ofpbuf_try_pull(msg, sizeof *ogds);
      if (!ogds) {
          VLOG_WARN_RL(&bad_ofmsg_rl, "OFPST11_GROUP_DESC reply has %"PRIu32" "
                       "leftover bytes at end", msg->size);
          return OFPERR_OFPBRC_BAD_LEN;
      }
      gd->type = ogds->type;
      gd->group_id = ntohl(ogds->group_id);
  
      length = ntohs(ogds->length);
      if (length < sizeof *ogds || length - sizeof *ogds > msg->size) {
          VLOG_WARN_RL(&bad_ofmsg_rl, "OFPST11_GROUP_DESC reply claims invalid "
                       "length %"PRIuSIZE, length);
          return OFPERR_OFPBRC_BAD_LEN;
      }
  
      return ofputil_pull_ofp11_buckets(msg, length - sizeof *ogds, version,
                                        &gd->buckets);
  }
  
  static int
  ofputil_decode_ofp15_group_desc_reply(struct ofputil_group_desc *gd,
                                        struct ofpbuf *msg,
                                        enum ofp_version version)
  {
      struct ofp15_group_desc_stats *ogds;
      uint16_t length, bucket_list_len;
      int error;
  
      if (!msg->header) {
          ofpraw_pull_assert(msg);
      }
  
      if (!msg->size) {
          return EOF;
      }
  
      ogds = ofpbuf_try_pull(msg, sizeof *ogds);
      if (!ogds) {
          VLOG_WARN_RL(&bad_ofmsg_rl, "OFPST11_GROUP_DESC reply has %"PRIu32" "
                       "leftover bytes at end", msg->size);
          return OFPERR_OFPBRC_BAD_LEN;
      }
      gd->type = ogds->type;
      gd->group_id = ntohl(ogds->group_id);
  
      length = ntohs(ogds->length);
      if (length < sizeof *ogds || length - sizeof *ogds > msg->size) {
          VLOG_WARN_RL(&bad_ofmsg_rl, "OFPST11_GROUP_DESC reply claims invalid "
                       "length %u", length);
          return OFPERR_OFPBRC_BAD_LEN;
      }
  
      bucket_list_len = ntohs(ogds->bucket_list_len);
      if (length < bucket_list_len + sizeof *ogds) {
          VLOG_WARN_RL(&bad_ofmsg_rl, "OFPST11_GROUP_DESC reply claims invalid "
                       "bucket list length %u", bucket_list_len);
          return OFPERR_OFPBRC_BAD_LEN;
      }
      error = ofputil_pull_ofp15_buckets(msg, bucket_list_len, version,
                                         &gd->buckets);
      if (error) {
          return error;
      }
  
      /* By definition group desc messages don't have a group mod command.
       * However, parse_group_prop_ntr_selection_method() checks to make sure
       * that the command is OFPGC15_ADD or OFPGC15_DELETE to guard
       * against group mod messages with other commands supplying
       * a NTR selection method group experimenter property.
       * Such properties are valid for group desc replies so
       * claim that the group mod command is OFPGC15_ADD to
       * satisfy the check in parse_group_prop_ntr_selection_method() */
      return parse_ofp15_group_properties(msg, gd->type, OFPGC15_ADD, &gd->props,
                                          msg->size);
  }
  
  /* Converts a group description reply in 'msg' into an abstract
   * ofputil_group_desc in 'gd'.
   *
   * Multiple group description replies can be packed into a single OpenFlow
   * message.  Calling this function multiple times for a single 'msg' iterates
   * through the replies.  The caller must initially leave 'msg''s layer pointers
   * null and not modify them between calls.
   *
   * Returns 0 if successful, EOF if no replies were left in this 'msg',
   * otherwise a positive errno value. */
  int
  ofputil_decode_group_desc_reply(struct ofputil_group_desc *gd,
                                  struct ofpbuf *msg, enum ofp_version version)
  {
      ofputil_init_group_properties(&gd->props);
  
      switch (version)
      {
      case OFP11_VERSION:
      case OFP12_VERSION:
      case OFP13_VERSION:
      case OFP14_VERSION:
          return ofputil_decode_ofp11_group_desc_reply(gd, msg, version);
  
      case OFP15_VERSION:
          return ofputil_decode_ofp15_group_desc_reply(gd, msg, version);
  
      case OFP10_VERSION:
      default:
          OVS_NOT_REACHED();
      }
  }
  
  void
  ofputil_uninit_group_mod(struct ofputil_group_mod *gm)
  {
      ofputil_bucket_list_destroy(&gm->buckets);
  }
  
  static struct ofpbuf *
  ofputil_encode_ofp11_group_mod(enum ofp_version ofp_version,
                                 const struct ofputil_group_mod *gm)
  {
      struct ofpbuf *b;
      struct ofp11_group_mod *ogm;
      size_t start_ogm;
      struct ofputil_bucket *bucket;
  
      b = ofpraw_alloc(OFPRAW_OFPT11_GROUP_MOD, ofp_version, 0);
      start_ogm = b->size;
      ofpbuf_put_zeros(b, sizeof *ogm);
  
      LIST_FOR_EACH (bucket, list_node, &gm->buckets) {
          ofputil_put_ofp11_bucket(bucket, b, ofp_version);
      }
      ogm = ofpbuf_at_assert(b, start_ogm, sizeof *ogm);
      ogm->command = htons(gm->command);
      ogm->type = gm->type;
      ogm->group_id = htonl(gm->group_id);
  
      return b;
  }
  
  static struct ofpbuf *
  ofputil_encode_ofp15_group_mod(enum ofp_version ofp_version,
                                 const struct ofputil_group_mod *gm)
  {
      struct ofpbuf *b;
      struct ofp15_group_mod *ogm;
      size_t start_ogm;
      struct ofputil_bucket *bucket;
      struct id_pool *bucket_ids = NULL;
  
      b = ofpraw_alloc(OFPRAW_OFPT15_GROUP_MOD, ofp_version, 0);
      start_ogm = b->size;
      ofpbuf_put_zeros(b, sizeof *ogm);
  
      LIST_FOR_EACH (bucket, list_node, &gm->buckets) {
          uint32_t bucket_id;
  
          /* Generate a bucket id if none was supplied */
          if (bucket->bucket_id > OFPG15_BUCKET_MAX) {
              if (!bucket_ids) {
                  const struct ofputil_bucket *bkt;
  
                  bucket_ids = id_pool_create(0, OFPG15_BUCKET_MAX + 1);
  
                  /* Mark all bucket_ids that are present in gm
                   * as used in the pool. */
                  LIST_FOR_EACH_REVERSE (bkt, list_node, &gm->buckets) {
                      if (bkt == bucket) {
                          break;
                      }
                      if (bkt->bucket_id <= OFPG15_BUCKET_MAX) {
                          id_pool_add(bucket_ids, bkt->bucket_id);
                      }
                  }
              }
  
              if (!id_pool_alloc_id(bucket_ids, &bucket_id)) {
                  OVS_NOT_REACHED();
              }
          } else {
              bucket_id = bucket->bucket_id;
          }
  
          ofputil_put_ofp15_bucket(bucket, bucket_id, gm->type, b, ofp_version);
      }
      ogm = ofpbuf_at_assert(b, start_ogm, sizeof *ogm);
      ogm->command = htons(gm->command);
      ogm->type = gm->type;
      ogm->group_id = htonl(gm->group_id);
      ogm->command_bucket_id = htonl(gm->command_bucket_id);
      ogm->bucket_array_len = htons(b->size - start_ogm - sizeof *ogm);
  
      /* Add group properties */
      if (gm->props.selection_method[0]) {
          ofputil_put_group_prop_ntr_selection_method(ofp_version, &gm->props, b);
      }
  
      id_pool_destroy(bucket_ids);
      return b;
  }
  
  static void
  bad_group_cmd(enum ofp15_group_mod_command cmd)
  {
      const char *opt_version;
      const char *version;
      const char *cmd_str;
  
      switch (cmd) {
      case OFPGC15_ADD:
      case OFPGC15_MODIFY:
      case OFPGC15_DELETE:
          version = "1.1";
          opt_version = "11";
          break;
  
      case OFPGC15_INSERT_BUCKET:
      case OFPGC15_REMOVE_BUCKET:
          version = "1.5";
          opt_version = "15";
          break;
  
      default:
          OVS_NOT_REACHED();
      }
  
      switch (cmd) {
      case OFPGC15_ADD:
          cmd_str = "add-group";
          break;
  
      case OFPGC15_MODIFY:
          cmd_str = "mod-group";
          break;
  
      case OFPGC15_DELETE:
          cmd_str = "del-group";
          break;
  
      case OFPGC15_INSERT_BUCKET:
          cmd_str = "insert-bucket";
          break;
  
      case OFPGC15_REMOVE_BUCKET:
          cmd_str = "remove-bucket";
          break;
  
      default:
          OVS_NOT_REACHED();
      }
  
      ovs_fatal(0, "%s needs OpenFlow %s or later (\'-O OpenFlow%s\')",
                cmd_str, version, opt_version);
  
  }
  
  /* Converts abstract group mod 'gm' into a message for OpenFlow version
   * 'ofp_version' and returns the message. */
  struct ofpbuf *
  ofputil_encode_group_mod(enum ofp_version ofp_version,
                           const struct ofputil_group_mod *gm)
  {
  
      switch (ofp_version) {
      case OFP10_VERSION:
          bad_group_cmd(gm->command);
  
      case OFP11_VERSION:
      case OFP12_VERSION:
      case OFP13_VERSION:
      case OFP14_VERSION:
          if (gm->command > OFPGC11_DELETE) {
              bad_group_cmd(gm->command);
          }
          return ofputil_encode_ofp11_group_mod(ofp_version, gm);
  
      case OFP15_VERSION:
          return ofputil_encode_ofp15_group_mod(ofp_version, gm);
  
      default:
          OVS_NOT_REACHED();
      }
  }
  
  static enum ofperr
  ofputil_pull_ofp11_group_mod(struct ofpbuf *msg, enum ofp_version ofp_version,
                               struct ofputil_group_mod *gm)
  {
      const struct ofp11_group_mod *ogm;
      enum ofperr error;
  
      ogm = ofpbuf_pull(msg, sizeof *ogm);
      gm->command = ntohs(ogm->command);
      gm->type = ogm->type;
      gm->group_id = ntohl(ogm->group_id);
      gm->command_bucket_id = OFPG15_BUCKET_ALL;
  
      error = ofputil_pull_ofp11_buckets(msg, msg->size, ofp_version,
                                         &gm->buckets);
  
      /* OF1.3.5+ prescribes an error when an OFPGC_DELETE includes buckets. */
      if (!error
          && ofp_version >= OFP13_VERSION
          && gm->command == OFPGC11_DELETE
          && !list_is_empty(&gm->buckets)) {
          error = OFPERR_OFPGMFC_INVALID_GROUP;
      }
  
      return error;
  }
  
  static enum ofperr
  ofputil_pull_ofp15_group_mod(struct ofpbuf *msg, enum ofp_version ofp_version,
                               struct ofputil_group_mod *gm)
  {
      const struct ofp15_group_mod *ogm;
      uint16_t bucket_list_len;
      enum ofperr error = OFPERR_OFPGMFC_BAD_BUCKET;
  
      ogm = ofpbuf_pull(msg, sizeof *ogm);
      gm->command = ntohs(ogm->command);
      gm->type = ogm->type;
      gm->group_id = ntohl(ogm->group_id);
  
      gm->command_bucket_id = ntohl(ogm->command_bucket_id);
      switch (gm->command) {
      case OFPGC15_REMOVE_BUCKET:
          if (gm->command_bucket_id == OFPG15_BUCKET_ALL) {
              error = 0;
          }
          /* Fall through */
      case OFPGC15_INSERT_BUCKET:
          if (gm->command_bucket_id <= OFPG15_BUCKET_MAX ||
              gm->command_bucket_id == OFPG15_BUCKET_FIRST
              || gm->command_bucket_id == OFPG15_BUCKET_LAST) {
              error = 0;
          }
          break;
  
      case OFPGC11_ADD:
      case OFPGC11_MODIFY:
      case OFPGC11_DELETE:
      default:
          if (gm->command_bucket_id == OFPG15_BUCKET_ALL) {
              error = 0;
          }
          break;
      }
      if (error) {
          VLOG_WARN_RL(&bad_ofmsg_rl,
                       "group command bucket id (%u) is out of range",
                       gm->command_bucket_id);
          return OFPERR_OFPGMFC_BAD_BUCKET;
      }
  
      bucket_list_len = ntohs(ogm->bucket_array_len);
      error = ofputil_pull_ofp15_buckets(msg, bucket_list_len, ofp_version,
                                         &gm->buckets);
      if (error) {
          return error;
      }
  
      return parse_ofp15_group_properties(msg, gm->type, gm->command, &gm->props,
                                          msg->size);
  }
  
  /* Converts OpenFlow group mod message 'oh' into an abstract group mod in
   * 'gm'.  Returns 0 if successful, otherwise an OpenFlow error code. */
  enum ofperr
  ofputil_decode_group_mod(const struct ofp_header *oh,
                           struct ofputil_group_mod *gm)
  {
      enum ofp_version ofp_version = oh->version;
      struct ofpbuf msg;
      struct ofputil_bucket *bucket;
      enum ofperr err;
  
      ofpbuf_use_const(&msg, oh, ntohs(oh->length));
      ofpraw_pull_assert(&msg);
  
      ofputil_init_group_properties(&gm->props);
  
      switch (ofp_version)
      {
      case OFP11_VERSION:
      case OFP12_VERSION:
      case OFP13_VERSION:
      case OFP14_VERSION:
          err = ofputil_pull_ofp11_group_mod(&msg, ofp_version, gm);
          break;
  
      case OFP15_VERSION:
          err = ofputil_pull_ofp15_group_mod(&msg, ofp_version, gm);
          break;
  
      case OFP10_VERSION:
      default:
          OVS_NOT_REACHED();
      }
  
      if (err) {
          return err;
      }
  
      switch (gm->type) {
      case OFPGT11_INDIRECT:
          if (!list_is_singleton(&gm->buckets)) {
              return OFPERR_OFPGMFC_OUT_OF_BUCKETS;
          }
          break;
      case OFPGT11_ALL:
      case OFPGT11_SELECT:
      case OFPGT11_FF:
          break;
      default:
          OVS_NOT_REACHED();
      }
  
      switch (gm->command) {
      case OFPGC11_ADD:
      case OFPGC11_MODIFY:
      case OFPGC11_DELETE:
      case OFPGC15_INSERT_BUCKET:
          break;
      case OFPGC15_REMOVE_BUCKET:
          if (!list_is_empty(&gm->buckets)) {
              return OFPERR_OFPGMFC_BAD_BUCKET;
          }
          break;
      default:
          OVS_NOT_REACHED();
      }
  
      LIST_FOR_EACH (bucket, list_node, &gm->buckets) {
          switch (gm->type) {
          case OFPGT11_ALL:
          case OFPGT11_INDIRECT:
              if (ofputil_bucket_has_liveness(bucket)) {
                  return OFPERR_OFPGMFC_WATCH_UNSUPPORTED;
              }
              break;
          case OFPGT11_SELECT:
              break;
          case OFPGT11_FF:
              if (!ofputil_bucket_has_liveness(bucket)) {
                  return OFPERR_OFPGMFC_INVALID_GROUP;
              }
              break;
          default:
              OVS_NOT_REACHED();
          }
      }
  
      return 0;
  }
  
  /* Parse a queue status request message into 'oqsr'.
   * Returns 0 if successful, otherwise an OFPERR_* number. */
  enum ofperr
  ofputil_decode_queue_stats_request(const struct ofp_header *request,
                                     struct ofputil_queue_stats_request *oqsr)
  {
      switch ((enum ofp_version)request->version) {
      case OFP15_VERSION:
      case OFP14_VERSION:
      case OFP13_VERSION:
      case OFP12_VERSION:
      case OFP11_VERSION: {
          const struct ofp11_queue_stats_request *qsr11 = ofpmsg_body(request);
          oqsr->queue_id = ntohl(qsr11->queue_id);
          return ofputil_port_from_ofp11(qsr11->port_no, &oqsr->port_no);
      }
  
      case OFP10_VERSION: {
          const struct ofp10_queue_stats_request *qsr10 = ofpmsg_body(request);
          oqsr->queue_id = ntohl(qsr10->queue_id);
          oqsr->port_no = u16_to_ofp(ntohs(qsr10->port_no));
          /* OF 1.0 uses OFPP_ALL for OFPP_ANY */
          if (oqsr->port_no == OFPP_ALL) {
              oqsr->port_no = OFPP_ANY;
          }
          return 0;
      }
  
      default:
          OVS_NOT_REACHED();
      }
  }
  
  /* Encode a queue stats request for 'oqsr', the encoded message
   * will be for OpenFlow version 'ofp_version'. Returns message
   * as a struct ofpbuf. Returns encoded message on success, NULL on error. */
  struct ofpbuf *
  ofputil_encode_queue_stats_request(enum ofp_version ofp_version,
                                     const struct ofputil_queue_stats_request *oqsr)
  {
      struct ofpbuf *request;
  
      switch (ofp_version) {
      case OFP11_VERSION:
      case OFP12_VERSION:
      case OFP13_VERSION:
      case OFP14_VERSION:
      case OFP15_VERSION: {
          struct ofp11_queue_stats_request *req;
          request = ofpraw_alloc(OFPRAW_OFPST11_QUEUE_REQUEST, ofp_version, 0);
          req = ofpbuf_put_zeros(request, sizeof *req);
          req->port_no = ofputil_port_to_ofp11(oqsr->port_no);
          req->queue_id = htonl(oqsr->queue_id);
          break;
      }
      case OFP10_VERSION: {
          struct ofp10_queue_stats_request *req;
          request = ofpraw_alloc(OFPRAW_OFPST10_QUEUE_REQUEST, ofp_version, 0);
          req = ofpbuf_put_zeros(request, sizeof *req);
          /* OpenFlow 1.0 needs OFPP_ALL instead of OFPP_ANY */
          req->port_no = htons(ofp_to_u16(oqsr->port_no == OFPP_ANY
                                          ? OFPP_ALL : oqsr->port_no));
          req->queue_id = htonl(oqsr->queue_id);
          break;
      }
      default:
          OVS_NOT_REACHED();
      }
  
      return request;
  }
  
  /* Returns the number of queue stats elements in OFPTYPE_QUEUE_STATS_REPLY
   * message 'oh'. */
  size_t
  ofputil_count_queue_stats(const struct ofp_header *oh)
  {
      struct ofputil_queue_stats qs;
      struct ofpbuf b;
      size_t n = 0;
  
      ofpbuf_use_const(&b, oh, ntohs(oh->length));
      ofpraw_pull_assert(&b);
      while (!ofputil_decode_queue_stats(&qs, &b)) {
          n++;
      }
      return n;
  }
  
  static enum ofperr
  ofputil_queue_stats_from_ofp10(struct ofputil_queue_stats *oqs,
                                 const struct ofp10_queue_stats *qs10)
  {
      oqs->port_no = u16_to_ofp(ntohs(qs10->port_no));
      oqs->queue_id = ntohl(qs10->queue_id);
      oqs->tx_bytes = ntohll(get_32aligned_be64(&qs10->tx_bytes));
      oqs->tx_packets = ntohll(get_32aligned_be64(&qs10->tx_packets));
      oqs->tx_errors = ntohll(get_32aligned_be64(&qs10->tx_errors));
      oqs->duration_sec = oqs->duration_nsec = UINT32_MAX;
  
      return 0;
  }
  
  static enum ofperr
  ofputil_queue_stats_from_ofp11(struct ofputil_queue_stats *oqs,
                                 const struct ofp11_queue_stats *qs11)
  {
      enum ofperr error;
  
      error = ofputil_port_from_ofp11(qs11->port_no, &oqs->port_no);
      if (error) {
          return error;
      }
  
      oqs->queue_id = ntohl(qs11->queue_id);
      oqs->tx_bytes = ntohll(qs11->tx_bytes);
      oqs->tx_packets = ntohll(qs11->tx_packets);
      oqs->tx_errors = ntohll(qs11->tx_errors);
      oqs->duration_sec = oqs->duration_nsec = UINT32_MAX;
  
      return 0;
  }
  
  static enum ofperr
  ofputil_queue_stats_from_ofp13(struct ofputil_queue_stats *oqs,
                                 const struct ofp13_queue_stats *qs13)
  {
      enum ofperr error = ofputil_queue_stats_from_ofp11(oqs, &qs13->qs);
      if (!error) {
          oqs->duration_sec = ntohl(qs13->duration_sec);
          oqs->duration_nsec = ntohl(qs13->duration_nsec);
      }
  
      return error;
  }
  
  static enum ofperr
  ofputil_pull_ofp14_queue_stats(struct ofputil_queue_stats *oqs,
                                 struct ofpbuf *msg)
  {
      const struct ofp14_queue_stats *qs14;
      size_t len;
  
      qs14 = ofpbuf_try_pull(msg, sizeof *qs14);
      if (!qs14) {
          return OFPERR_OFPBRC_BAD_LEN;
      }
  
      len = ntohs(qs14->length);
      if (len < sizeof *qs14 || len - sizeof *qs14 > msg->size) {
          return OFPERR_OFPBRC_BAD_LEN;
      }
      ofpbuf_pull(msg, len - sizeof *qs14);
  
      /* No properties yet defined, so ignore them for now. */
  
      return ofputil_queue_stats_from_ofp13(oqs, &qs14->qs);
  }
  
  /* Converts an OFPST_QUEUE_STATS reply in 'msg' into an abstract
   * ofputil_queue_stats in 'qs'.
   *
   * Multiple OFPST_QUEUE_STATS replies can be packed into a single OpenFlow
   * message.  Calling this function multiple times for a single 'msg' iterates
   * through the replies.  The caller must initially leave 'msg''s layer pointers
   * null and not modify them between calls.
   *
   * Returns 0 if successful, EOF if no replies were left in this 'msg',
   * otherwise a positive errno value. */
  int
  ofputil_decode_queue_stats(struct ofputil_queue_stats *qs, struct ofpbuf *msg)
  {
      enum ofperr error;
      enum ofpraw raw;
  
      error = (msg->header ? ofpraw_decode(&raw, msg->header)
               : ofpraw_pull(&raw, msg));
      if (error) {
          return error;
      }
  
      if (!msg->size) {
          return EOF;
      } else if (raw == OFPRAW_OFPST14_QUEUE_REPLY) {
          return ofputil_pull_ofp14_queue_stats(qs, msg);
      } else if (raw == OFPRAW_OFPST13_QUEUE_REPLY) {
          const struct ofp13_queue_stats *qs13;
  
          qs13 = ofpbuf_try_pull(msg, sizeof *qs13);
          if (!qs13) {
              goto bad_len;
          }
          return ofputil_queue_stats_from_ofp13(qs, qs13);
      } else if (raw == OFPRAW_OFPST11_QUEUE_REPLY) {
          const struct ofp11_queue_stats *qs11;
  
          qs11 = ofpbuf_try_pull(msg, sizeof *qs11);
          if (!qs11) {
              goto bad_len;
          }
          return ofputil_queue_stats_from_ofp11(qs, qs11);
      } else if (raw == OFPRAW_OFPST10_QUEUE_REPLY) {
          const struct ofp10_queue_stats *qs10;
  
          qs10 = ofpbuf_try_pull(msg, sizeof *qs10);
          if (!qs10) {
              goto bad_len;
          }
          return ofputil_queue_stats_from_ofp10(qs, qs10);
      } else {
          OVS_NOT_REACHED();
      }
  
   bad_len:
      VLOG_WARN_RL(&bad_ofmsg_rl, "OFPST_QUEUE reply has %"PRIu32" leftover "
                   "bytes at end", msg->size);
      return OFPERR_OFPBRC_BAD_LEN;
  }
  
  static void
  ofputil_queue_stats_to_ofp10(const struct ofputil_queue_stats *oqs,
                               struct ofp10_queue_stats *qs10)
  {
      qs10->port_no = htons(ofp_to_u16(oqs->port_no));
      memset(qs10->pad, 0, sizeof qs10->pad);
      qs10->queue_id = htonl(oqs->queue_id);
      put_32aligned_be64(&qs10->tx_bytes, htonll(oqs->tx_bytes));
      put_32aligned_be64(&qs10->tx_packets, htonll(oqs->tx_packets));
      put_32aligned_be64(&qs10->tx_errors, htonll(oqs->tx_errors));
  }
  
  static void
  ofputil_queue_stats_to_ofp11(const struct ofputil_queue_stats *oqs,
                               struct ofp11_queue_stats *qs11)
  {
      qs11->port_no = ofputil_port_to_ofp11(oqs->port_no);
      qs11->queue_id = htonl(oqs->queue_id);
      qs11->tx_bytes = htonll(oqs->tx_bytes);
      qs11->tx_packets = htonll(oqs->tx_packets);
      qs11->tx_errors = htonll(oqs->tx_errors);
  }
  
  static void
  ofputil_queue_stats_to_ofp13(const struct ofputil_queue_stats *oqs,
                               struct ofp13_queue_stats *qs13)
  {
      ofputil_queue_stats_to_ofp11(oqs, &qs13->qs);
      if (oqs->duration_sec != UINT32_MAX) {
          qs13->duration_sec = htonl(oqs->duration_sec);
          qs13->duration_nsec = htonl(oqs->duration_nsec);
      } else {
          qs13->duration_sec = OVS_BE32_MAX;
          qs13->duration_nsec = OVS_BE32_MAX;
      }
  }
  
  static void
  ofputil_queue_stats_to_ofp14(const struct ofputil_queue_stats *oqs,
                               struct ofp14_queue_stats *qs14)
  {
      qs14->length = htons(sizeof *qs14);
      memset(qs14->pad, 0, sizeof qs14->pad);
      ofputil_queue_stats_to_ofp13(oqs, &qs14->qs);
  }
  
  
  /* Encode a queue stat for 'oqs' and append it to 'replies'. */
  void
  ofputil_append_queue_stat(struct ovs_list *replies,
                            const struct ofputil_queue_stats *oqs)
  {
      switch (ofpmp_version(replies)) {
      case OFP13_VERSION: {
          struct ofp13_queue_stats *reply = ofpmp_append(replies, sizeof *reply);
          ofputil_queue_stats_to_ofp13(oqs, reply);
          break;
      }
  
      case OFP12_VERSION:
      case OFP11_VERSION: {
          struct ofp11_queue_stats *reply = ofpmp_append(replies, sizeof *reply);
          ofputil_queue_stats_to_ofp11(oqs, reply);
          break;
      }
  
      case OFP10_VERSION: {
          struct ofp10_queue_stats *reply = ofpmp_append(replies, sizeof *reply);
          ofputil_queue_stats_to_ofp10(oqs, reply);
          break;
      }
  
      case OFP14_VERSION:
      case OFP15_VERSION: {
          struct ofp14_queue_stats *reply = ofpmp_append(replies, sizeof *reply);
          ofputil_queue_stats_to_ofp14(oqs, reply);
          break;
      }
  
      default:
          OVS_NOT_REACHED();
      }
  }
  
  enum ofperr
  ofputil_decode_bundle_ctrl(const struct ofp_header *oh,
                             struct ofputil_bundle_ctrl_msg *msg)
  {
      struct ofpbuf b;
      enum ofpraw raw;
      const struct ofp14_bundle_ctrl_msg *m;
  
      ofpbuf_use_const(&b, oh, ntohs(oh->length));
      raw = ofpraw_pull_assert(&b);
      ovs_assert(raw == OFPRAW_OFPT14_BUNDLE_CONTROL);
  
      m = b.msg;
      msg->bundle_id = ntohl(m->bundle_id);
      msg->type = ntohs(m->type);
      msg->flags = ntohs(m->flags);
  
      return 0;
  }
  
  struct ofpbuf *
  ofputil_encode_bundle_ctrl_request(enum ofp_version ofp_version,
                                     struct ofputil_bundle_ctrl_msg *bc)
  {
      struct ofpbuf *request;
      struct ofp14_bundle_ctrl_msg *m;
  
      switch (ofp_version) {
      case OFP10_VERSION:
      case OFP11_VERSION:
      case OFP12_VERSION:
      case OFP13_VERSION:
          ovs_fatal(0, "bundles need OpenFlow 1.4 or later "
                       "(\'-O OpenFlow14\')");
      case OFP14_VERSION:
      case OFP15_VERSION:
          request = ofpraw_alloc(OFPRAW_OFPT14_BUNDLE_CONTROL, ofp_version, 0);
          m = ofpbuf_put_zeros(request, sizeof *m);
  
          m->bundle_id = htonl(bc->bundle_id);
          m->type = htons(bc->type);
          m->flags = htons(bc->flags);
          break;
      default:
          OVS_NOT_REACHED();
      }
  
      return request;
  }
  
  struct ofpbuf *
  ofputil_encode_bundle_ctrl_reply(const struct ofp_header *oh,
                                   struct ofputil_bundle_ctrl_msg *msg)
  {
      struct ofpbuf *buf;
      struct ofp14_bundle_ctrl_msg *m;
  
      buf = ofpraw_alloc_reply(OFPRAW_OFPT14_BUNDLE_CONTROL, oh, 0);
      m = ofpbuf_put_zeros(buf, sizeof *m);
  
      m->bundle_id = htonl(msg->bundle_id);
      m->type = htons(msg->type);
      m->flags = htons(msg->flags);
  
      return buf;
  }
  
  /* Return true for bundlable state change requests, false for other messages.
   */
  static bool
  ofputil_is_bundlable(enum ofptype type)
  {
      switch (type) {
          /* Minimum required by OpenFlow 1.4. */
      case OFPTYPE_PORT_MOD:
      case OFPTYPE_FLOW_MOD:
          return true;
  
          /* Nice to have later. */
      case OFPTYPE_FLOW_MOD_TABLE_ID:
      case OFPTYPE_GROUP_MOD:
      case OFPTYPE_TABLE_MOD:
      case OFPTYPE_METER_MOD:
      case OFPTYPE_PACKET_OUT:
      case OFPTYPE_NXT_GENEVE_TABLE_MOD:
  
          /* Not to be bundlable. */
      case OFPTYPE_ECHO_REQUEST:
      case OFPTYPE_FEATURES_REQUEST:
      case OFPTYPE_GET_CONFIG_REQUEST:
      case OFPTYPE_SET_CONFIG:
      case OFPTYPE_BARRIER_REQUEST:
      case OFPTYPE_ROLE_REQUEST:
      case OFPTYPE_ECHO_REPLY:
      case OFPTYPE_SET_FLOW_FORMAT:
      case OFPTYPE_SET_PACKET_IN_FORMAT:
      case OFPTYPE_SET_CONTROLLER_ID:
      case OFPTYPE_FLOW_AGE:
      case OFPTYPE_FLOW_MONITOR_CANCEL:
      case OFPTYPE_SET_ASYNC_CONFIG:
      case OFPTYPE_GET_ASYNC_REQUEST:
      case OFPTYPE_DESC_STATS_REQUEST:
      case OFPTYPE_FLOW_STATS_REQUEST:
      case OFPTYPE_AGGREGATE_STATS_REQUEST:
      case OFPTYPE_TABLE_STATS_REQUEST:
      case OFPTYPE_TABLE_FEATURES_STATS_REQUEST:
      case OFPTYPE_TABLE_DESC_REQUEST:
      case OFPTYPE_PORT_STATS_REQUEST:
      case OFPTYPE_QUEUE_STATS_REQUEST:
      case OFPTYPE_PORT_DESC_STATS_REQUEST:
      case OFPTYPE_FLOW_MONITOR_STATS_REQUEST:
      case OFPTYPE_METER_STATS_REQUEST:
      case OFPTYPE_METER_CONFIG_STATS_REQUEST:
      case OFPTYPE_METER_FEATURES_STATS_REQUEST:
      case OFPTYPE_GROUP_STATS_REQUEST:
      case OFPTYPE_GROUP_DESC_STATS_REQUEST:
      case OFPTYPE_GROUP_FEATURES_STATS_REQUEST:
      case OFPTYPE_QUEUE_GET_CONFIG_REQUEST:
      case OFPTYPE_BUNDLE_CONTROL:
      case OFPTYPE_BUNDLE_ADD_MESSAGE:
      case OFPTYPE_HELLO:
      case OFPTYPE_ERROR:
      case OFPTYPE_FEATURES_REPLY:
      case OFPTYPE_GET_CONFIG_REPLY:
      case OFPTYPE_PACKET_IN:
      case OFPTYPE_FLOW_REMOVED:
      case OFPTYPE_PORT_STATUS:
      case OFPTYPE_BARRIER_REPLY:
      case OFPTYPE_QUEUE_GET_CONFIG_REPLY:
      case OFPTYPE_DESC_STATS_REPLY:
      case OFPTYPE_FLOW_STATS_REPLY:
      case OFPTYPE_QUEUE_STATS_REPLY:
      case OFPTYPE_PORT_STATS_REPLY:
      case OFPTYPE_TABLE_STATS_REPLY:
      case OFPTYPE_AGGREGATE_STATS_REPLY:
      case OFPTYPE_PORT_DESC_STATS_REPLY:
      case OFPTYPE_ROLE_REPLY:
      case OFPTYPE_FLOW_MONITOR_PAUSED:
      case OFPTYPE_FLOW_MONITOR_RESUMED:
      case OFPTYPE_FLOW_MONITOR_STATS_REPLY:
      case OFPTYPE_GET_ASYNC_REPLY:
      case OFPTYPE_GROUP_STATS_REPLY:
      case OFPTYPE_GROUP_DESC_STATS_REPLY:
      case OFPTYPE_GROUP_FEATURES_STATS_REPLY:
      case OFPTYPE_METER_STATS_REPLY:
      case OFPTYPE_METER_CONFIG_STATS_REPLY:
      case OFPTYPE_METER_FEATURES_STATS_REPLY:
      case OFPTYPE_TABLE_FEATURES_STATS_REPLY:
      case OFPTYPE_TABLE_DESC_REPLY:
      case OFPTYPE_ROLE_STATUS:
      case OFPTYPE_NXT_GENEVE_TABLE_REQUEST:
      case OFPTYPE_NXT_GENEVE_TABLE_REPLY:
          break;
      }
  
      return false;
  }
  
  enum ofperr
  ofputil_decode_bundle_add(const struct ofp_header *oh,
                            struct ofputil_bundle_add_msg *msg,
                            enum ofptype *type_ptr)
  {
      const struct ofp14_bundle_ctrl_msg *m;
      struct ofpbuf b;
      enum ofpraw raw;
      size_t inner_len;
      enum ofperr error;
      enum ofptype type;
  
      ofpbuf_use_const(&b, oh, ntohs(oh->length));
      raw = ofpraw_pull_assert(&b);
      ovs_assert(raw == OFPRAW_OFPT14_BUNDLE_ADD_MESSAGE);
  
      m = ofpbuf_pull(&b, sizeof *m);
      msg->bundle_id = ntohl(m->bundle_id);
      msg->flags = ntohs(m->flags);
  
      msg->msg = b.data;
      if (msg->msg->version != oh->version) {
          return OFPERR_NXBFC_BAD_VERSION;
      }
      inner_len = ntohs(msg->msg->length);
      if (inner_len < sizeof(struct ofp_header) || inner_len > b.size) {
          return OFPERR_OFPBFC_MSG_BAD_LEN;
      }
      if (msg->msg->xid != oh->xid) {
          return OFPERR_OFPBFC_MSG_BAD_XID;
      }
  
      /* Reject unbundlable messages. */
      if (!type_ptr) {
          type_ptr = &type;
      }
      error = ofptype_decode(type_ptr, msg->msg);
      if (error) {
          VLOG_WARN_RL(&bad_ofmsg_rl, "OFPT14_BUNDLE_ADD_MESSAGE contained "
                       "message is unparsable (%s)", ofperr_get_name(error));
          return OFPERR_OFPBFC_MSG_UNSUP; /* 'error' would be confusing. */
      }
  
      if (!ofputil_is_bundlable(*type_ptr)) {
          VLOG_WARN_RL(&bad_ofmsg_rl, "%s message not allowed inside "
                       "OFPT14_BUNDLE_ADD_MESSAGE", ofptype_get_name(*type_ptr));
          return OFPERR_OFPBFC_MSG_UNSUP;
      }
  
      return 0;
  }
  
  struct ofpbuf *
  ofputil_encode_bundle_add(enum ofp_version ofp_version,
                            struct ofputil_bundle_add_msg *msg)
  {
      struct ofpbuf *request;
      struct ofp14_bundle_ctrl_msg *m;
  
      /* Must use the same xid as the embedded message. */
      request = ofpraw_alloc_xid(OFPRAW_OFPT14_BUNDLE_ADD_MESSAGE, ofp_version,
                                 msg->msg->xid, 0);
      m = ofpbuf_put_zeros(request, sizeof *m);
  
      m->bundle_id = htonl(msg->bundle_id);
      m->flags = htons(msg->flags);
      ofpbuf_put(request, msg->msg, ntohs(msg->msg->length));
  
      return request;
  }
  
  static void
  encode_geneve_table_mappings(struct ofpbuf *b, struct ovs_list *mappings)
  {
      struct ofputil_geneve_map *map;
  
      LIST_FOR_EACH (map, list_node, mappings) {
          struct nx_geneve_map *nx_map;
  
          nx_map = ofpbuf_put_zeros(b, sizeof *nx_map);
          nx_map->option_class = htons(map->option_class);
          nx_map->option_type = map->option_type;
          nx_map->option_len = map->option_len;
          nx_map->index = htons(map->index);
      }
  }
  
  struct ofpbuf *
  ofputil_encode_geneve_table_mod(enum ofp_version ofp_version,
                                  struct ofputil_geneve_table_mod *gtm)
  {
      struct ofpbuf *b;
      struct nx_geneve_table_mod *nx_gtm;
  
      b = ofpraw_alloc(OFPRAW_NXT_GENEVE_TABLE_MOD, ofp_version, 0);
      nx_gtm = ofpbuf_put_zeros(b, sizeof *nx_gtm);
      nx_gtm->command = htons(gtm->command);
      encode_geneve_table_mappings(b, &gtm->mappings);
  
      return b;
  }
  
  static enum ofperr
  decode_geneve_table_mappings(struct ofpbuf *msg, unsigned int max_fields,
                               struct ovs_list *mappings)
  {
      list_init(mappings);
  
      while (msg->size) {
          struct nx_geneve_map *nx_map;
          struct ofputil_geneve_map *map;
  
          nx_map = ofpbuf_pull(msg, sizeof *nx_map);
          map = xmalloc(sizeof *map);
          list_push_back(mappings, &map->list_node);
  
          map->option_class = ntohs(nx_map->option_class);
          map->option_type = nx_map->option_type;
  
          map->option_len = nx_map->option_len;
          if (map->option_len == 0 || map->option_len % 4 ||
              map->option_len > GENEVE_MAX_OPT_SIZE) {
              VLOG_WARN_RL(&bad_ofmsg_rl,
                           "geneve table option length (%u) is not a valid option size",
                           map->option_len);
              ofputil_uninit_geneve_table(mappings);
              return OFPERR_NXGTMFC_BAD_OPT_LEN;
          }
  
          map->index = ntohs(nx_map->index);
          if (map->index >= max_fields) {
              VLOG_WARN_RL(&bad_ofmsg_rl,
                           "geneve table field index (%u) is too large (max %u)",
                           map->index, max_fields - 1);
              ofputil_uninit_geneve_table(mappings);
              return OFPERR_NXGTMFC_BAD_FIELD_IDX;
          }
      }
  
      return 0;
  }
  
  enum ofperr
  ofputil_decode_geneve_table_mod(const struct ofp_header *oh,
                                  struct ofputil_geneve_table_mod *gtm)
  {
      struct ofpbuf msg;
      struct nx_geneve_table_mod *nx_gtm;
  
      ofpbuf_use_const(&msg, oh, ntohs(oh->length));
      ofpraw_pull_assert(&msg);
  
      nx_gtm = ofpbuf_pull(&msg, sizeof *nx_gtm);
      gtm->command = ntohs(nx_gtm->command);
      if (gtm->command > NXGTMC_CLEAR) {
          VLOG_WARN_RL(&bad_ofmsg_rl,
                       "geneve table mod command (%u) is out of range",
                       gtm->command);
          return OFPERR_NXGTMFC_BAD_COMMAND;
      }
  
      return decode_geneve_table_mappings(&msg, TUN_METADATA_NUM_OPTS,
                                          &gtm->mappings);
  }
  
  struct ofpbuf *
  ofputil_encode_geneve_table_reply(const struct ofp_header *oh,
                                    struct ofputil_geneve_table_reply *gtr)
  {
      struct ofpbuf *b;
      struct nx_geneve_table_reply *nx_gtr;
  
      b = ofpraw_alloc_reply(OFPRAW_NXT_GENEVE_TABLE_REPLY, oh, 0);
      nx_gtr = ofpbuf_put_zeros(b, sizeof *nx_gtr);
      nx_gtr->max_option_space = htonl(gtr->max_option_space);
      nx_gtr->max_fields = htons(gtr->max_fields);
  
      encode_geneve_table_mappings(b, &gtr->mappings);
  
      return b;
  }
  
  /* Decodes the NXT_GENEVE_TABLE_REPLY message in 'oh' into '*gtr'.  Returns 0
   * if successful, otherwise an ofperr.
   *
   * The decoder verifies that the indexes in 'gtr->mappings' are less than
   * 'gtr->max_fields', but the caller must ensure, if necessary, that they are
   * less than TUN_METADATA_NUM_OPTS. */
  enum ofperr
  ofputil_decode_geneve_table_reply(const struct ofp_header *oh,
                                    struct ofputil_geneve_table_reply *gtr)
  {
      struct ofpbuf msg;
      struct nx_geneve_table_reply *nx_gtr;
  
      ofpbuf_use_const(&msg, oh, ntohs(oh->length));
      ofpraw_pull_assert(&msg);
  
      nx_gtr = ofpbuf_pull(&msg, sizeof *nx_gtr);
      gtr->max_option_space = ntohl(nx_gtr->max_option_space);
      gtr->max_fields = ntohs(nx_gtr->max_fields);
  
      return decode_geneve_table_mappings(&msg, gtr->max_fields, &gtr->mappings);
  }
  
  void
  ofputil_uninit_geneve_table(struct ovs_list *mappings)
  {
      struct ofputil_geneve_map *map;
  
      LIST_FOR_EACH_POP (map, list_node, mappings) {
          free(map);
      }
  }
  