text: /*
   * Copyright (c) 2012, 2013, 2014, 2015, 2016 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 <errno.h>
  #include "byte-order.h"
  #include "openflow/openflow.h"
  #include "openflow/nicira-ext.h"
  #include "openvswitch/dynamic-string.h"
  #include "openvswitch/ofp-errors.h"
  #include "openvswitch/ofp-msgs.h"
  #include "openvswitch/ofp-print.h"
  #include "openvswitch/ofpbuf.h"
  #include "openvswitch/vlog.h"
  #include "util.h"
  
  VLOG_DEFINE_THIS_MODULE(ofp_errors);
  
  struct triplet {
      uint32_t vendor;
      int type, code;
  };
  
  #include "ofp-errors.inc"
  
  /* Returns an ofperr_domain that corresponds to the OpenFlow version number
   * 'version' (one of the possible values of struct ofp_header's 'version'
   * member).  Returns NULL if the version isn't defined or isn't understood by
   * OVS. */
  static const struct ofperr_domain *
  ofperr_domain_from_version(enum ofp_version version)
  {
      switch (version) {
      case OFP10_VERSION:
          return &ofperr_of10;
      case OFP11_VERSION:
          return &ofperr_of11;
      case OFP12_VERSION:
          return &ofperr_of12;
      case OFP13_VERSION:
          return &ofperr_of13;
      case OFP14_VERSION:
          return &ofperr_of14;
      case OFP15_VERSION:
          return &ofperr_of15;
      default:
          return NULL;
      }
  }
  
  /* Returns the name (e.g. "OpenFlow 1.0") of OpenFlow version 'version'. */
  const char *
  ofperr_domain_get_name(enum ofp_version version)
  {
      const struct ofperr_domain *domain = ofperr_domain_from_version(version);
      return domain ? domain->name : NULL;
  }
  
  /* Returns true if 'error' is a valid OFPERR_* value, false otherwise. */
  bool
  ofperr_is_valid(enum ofperr error)
  {
      return error >= OFPERR_OFS && error < OFPERR_OFS + OFPERR_N_ERRORS;
  }
  
  /* Returns the OFPERR_* value that corresponds to 'type' and 'code' within
   * 'version', or 0 if either no such OFPERR_* value exists or 'version' is
   * unknown. */
  static enum ofperr
  ofperr_decode(enum ofp_version version,
                uint32_t vendor, uint16_t type, uint16_t code)
  {
      const struct ofperr_domain *domain = ofperr_domain_from_version(version);
      return domain ? domain->decode(vendor, type, code) : 0;
  }
  
  /* Returns the name of 'error', e.g. "OFPBRC_BAD_TYPE" if 'error' is
   * OFPBRC_BAD_TYPE, or "<invalid>" if 'error' is not a valid OFPERR_* value.
   *
   * Consider ofperr_to_string() instead, if the error code might be an errno
   * value. */
  const char *
  ofperr_get_name(enum ofperr error)
  {
      return (ofperr_is_valid(error)
              ? error_names[error - OFPERR_OFS]
              : "<invalid>");
  }
  
  /* Returns the OFPERR_* value that corresponds for 'name', 0 if none exists.
   * For example, returns OFPERR_OFPHFC_INCOMPATIBLE if 'name' is
   * "OFPHFC_INCOMPATIBLE".
   *
   * This is probably useful only for debugging and testing. */
  enum ofperr
  ofperr_from_name(const char *name)
  {
      int i;
  
      for (i = 0; i < OFPERR_N_ERRORS; i++) {
          if (!strcmp(name, error_names[i])) {
              return i + OFPERR_OFS;
          }
      }
      return 0;
  }
  
  /* Returns an extended description name of 'error', e.g. "ofp_header.type not
   * supported." if 'error' is OFPBRC_BAD_TYPE, or "<invalid>" if 'error' is not
   * a valid OFPERR_* value. */
  const char *
  ofperr_get_description(enum ofperr error)
  {
      return (ofperr_is_valid(error)
              ? error_comments[error - OFPERR_OFS]
              : "<invalid>");
  }
  
  static const struct triplet *
  ofperr_get_triplet__(enum ofperr error, const struct ofperr_domain *domain)
  {
      size_t ofs = error - OFPERR_OFS;
  
      ovs_assert(ofperr_is_valid(error));
      return &domain->errors[ofs];
  }
  
  static struct ofpbuf *
  ofperr_encode_msg__(enum ofperr error, enum ofp_version ofp_version,
                      ovs_be32 xid, const void *data, size_t data_len)
  {
      static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
      const struct ofperr_domain *domain;
      const struct triplet *triplet;
      struct ofp_error_msg *oem;
      struct ofpbuf *buf;
  
      /* Get the error domain for 'ofp_version', or fall back to OF1.0. */
      domain = ofperr_domain_from_version(ofp_version);
      if (!domain) {
          VLOG_ERR_RL(&rl, "cannot encode error for unknown OpenFlow "
                      "version 0x%02x", ofp_version);
          domain = &ofperr_of10;
      }
  
      /* Make sure 'error' is valid in 'domain', or use a fallback error. */
      if (!ofperr_is_valid(error)) {
          /* 'error' seems likely to be a system errno value. */
          VLOG_ERR_RL(&rl, "invalid OpenFlow error code %d (%s)",
                      error, ovs_strerror(error));
          error = OFPERR_NXBRC_UNENCODABLE_ERROR;
      } else if (domain->errors[error - OFPERR_OFS].code < 0) {
          VLOG_ERR_RL(&rl, "cannot encode %s for %s",
                      ofperr_get_name(error), domain->name);
          error = OFPERR_NXBRC_UNENCODABLE_ERROR;
      }
  
      triplet = ofperr_get_triplet__(error, domain);
      if (!triplet->vendor) {
          buf = ofpraw_alloc_xid(OFPRAW_OFPT_ERROR, domain->version, xid,
                                 sizeof *oem + data_len);
  
          oem = ofpbuf_put_uninit(buf, sizeof *oem);
          oem->type = htons(triplet->type);
          oem->code = htons(triplet->code);
      } else if (ofp_version <= OFP11_VERSION) {
          struct nx_vendor_error *nve;
  
          buf = ofpraw_alloc_xid(OFPRAW_OFPT_ERROR, domain->version, xid,
                                 sizeof *oem + sizeof *nve + data_len);
  
          oem = ofpbuf_put_uninit(buf, sizeof *oem);
          oem->type = htons(NXET_VENDOR);
          oem->code = htons(NXVC_VENDOR_ERROR);
  
          nve = ofpbuf_put_uninit(buf, sizeof *nve);
          nve->vendor = htonl(triplet->vendor);
          nve->type = htons(triplet->type);
          nve->code = htons(triplet->code);
      } else {
          ovs_be32 vendor = htonl(triplet->vendor);
  
          buf = ofpraw_alloc_xid(OFPRAW_OFPT_ERROR, domain->version, xid,
                                 sizeof *oem + sizeof(uint32_t) + data_len);
  
          oem = ofpbuf_put_uninit(buf, sizeof *oem);
          oem->type = htons(OFPET12_EXPERIMENTER);
          oem->code = htons(triplet->type);
          ofpbuf_put(buf, &vendor, sizeof vendor);
      }
  
      ofpbuf_put(buf, data, MIN(data_len, UINT16_MAX - buf->size));
      ofpmsg_update_length(buf);
  
      return buf;
  }
  
  /* Creates and returns an OpenFlow message of type OFPT_ERROR that conveys the
   * given 'error'.
   *
   * 'oh->version' determines the OpenFlow version of the error reply.
   * 'oh->xid' determines the xid of the error reply.
   * The error reply will contain an initial subsequence of 'oh', up to
   * 'oh->length' (or however much fits).
   *
   * This function isn't appropriate for encoding OFPET_HELLO_FAILED error
   * messages.  Use ofperr_encode_hello() instead. */
  struct ofpbuf *
  ofperr_encode_reply(enum ofperr error, const struct ofp_header *oh)
  {
      return ofperr_encode_msg__(error, oh->version, oh->xid,
                                 oh, ntohs(oh->length));
  }
  
  /* Creates and returns an OpenFlow message of type OFPT_ERROR that conveys the
   * given 'error', in the error domain 'domain'.  The error message will include
   * the additional null-terminated text string 's'.
   *
   * If 'version' is an unknown version then OFP10_VERSION is used.
   * OFPET_HELLO_FAILED error messages are supposed to be backward-compatible,
   * so in theory this should work. */
  struct ofpbuf *
  ofperr_encode_hello(enum ofperr error, enum ofp_version ofp_version,
                      const char *s)
  {
      return ofperr_encode_msg__(error, ofp_version, htonl(0), s, strlen(s));
  }
  
  void
  ofperr_msg_format(struct ds *string, enum ofperr error,
                    const struct ofpbuf *payload,
                    const struct ofputil_port_map *port_map,
                    const struct ofputil_table_map *table_map)
  {
      ds_put_format(string, " %s\n", ofperr_get_name(error));
  
      if (error == OFPERR_OFPHFC_INCOMPATIBLE || error == OFPERR_OFPHFC_EPERM) {
          ds_put_printable(string, payload->data, payload->size);
      } else {
          char *s = ofp_to_string(payload->data, payload->size,
                                  port_map, table_map, 1);
          ds_put_cstr(string, s);
          free(s);
      }
  }
  
  int
  ofperr_get_vendor(enum ofperr error, enum ofp_version version)
  {
      const struct ofperr_domain *domain = ofperr_domain_from_version(version);
      return domain ? ofperr_get_triplet__(error, domain)->vendor : -1;
  }
  
  /* Returns the value that would go into an OFPT_ERROR message's 'type' for
   * encoding 'error' in 'domain'.  Returns -1 if 'error' is not encodable in
   * 'version' or 'version' is unknown.
   *
   * 'error' must be a valid OFPERR_* code, as checked by ofperr_is_valid(). */
  int
  ofperr_get_type(enum ofperr error, enum ofp_version version)
  {
      const struct ofperr_domain *domain = ofperr_domain_from_version(version);
      return domain ? ofperr_get_triplet__(error, domain)->type : -1;
  }
  
  /* Returns the value that would go into an OFPT_ERROR message's 'code' for
   * encoding 'error' in 'domain'.  Returns -1 if 'error' is not encodable in
   * 'version', 'version' is unknown or if 'error' represents a category
   * rather than a specific error.
   *
   *
   * 'error' must be a valid OFPERR_* code, as checked by ofperr_is_valid(). */
  int
  ofperr_get_code(enum ofperr error, enum ofp_version version)
  {
      const struct ofperr_domain *domain = ofperr_domain_from_version(version);
      return domain ? ofperr_get_triplet__(error, domain)->code : -1;
  }
  
  /* Tries to decode 'oh', which should be an OpenFlow OFPT_ERROR message.
   * Returns an OFPERR_* constant on success, 0 on failure.
   *
   * If 'payload' is nonnull, on success '*payload' is initialized with a copy of
   * the error's payload (copying is required because the payload is not properly
   * aligned).  The caller must free the payload (with ofpbuf_uninit()) when it
   * is no longer needed.  On failure, '*payload' is cleared. */
  enum ofperr
  ofperr_decode_msg(const struct ofp_header *oh, struct ofpbuf *payload)
  {
      const struct ofp_error_msg *oem;
      enum ofpraw raw;
      uint16_t type, code;
      uint32_t vendor;
  
      if (payload) {
          memset(payload, 0, sizeof *payload);
      }
  
      /* Pull off the error message. */
      struct ofpbuf b = ofpbuf_const_initializer(oh, ntohs(oh->length));
      enum ofperr error = ofpraw_pull(&raw, &b);
      if (error) {
          return 0;
      }
      oem = ofpbuf_pull(&b, sizeof *oem);
  
      /* Get the error type and code. */
      vendor = 0;
      type = ntohs(oem->type);
      code = ntohs(oem->code);
      if (type == NXET_VENDOR && code == NXVC_VENDOR_ERROR) {
          const struct nx_vendor_error *nve = ofpbuf_try_pull(&b, sizeof *nve);
          if (!nve) {
              return 0;
          }
  
          vendor = ntohl(nve->vendor);
          type = ntohs(nve->type);
          code = ntohs(nve->code);
      } else if (type == OFPET12_EXPERIMENTER) {
          const ovs_be32 *vendorp = ofpbuf_try_pull(&b, sizeof *vendorp);
          if (!vendorp) {
              return 0;
          }
  
          vendor = ntohl(*vendorp);
          type = code;
          code = 0;
      }
  
      /* Translate the error type and code into an ofperr. */
      error = ofperr_decode(oh->version, vendor, type, code);
      if (error && payload) {
          ofpbuf_init(payload, b.size);
          ofpbuf_push(payload, b.data, b.size);
      }
      return error;
  }
  
  /* If 'error' is a valid OFPERR_* value, returns its name
   * (e.g. "OFPBRC_BAD_TYPE" for OFPBRC_BAD_TYPE).  Otherwise, assumes that
   * 'error' is a positive errno value and returns what ovs_strerror() produces
   * for 'error'.  */
  const char *
  ofperr_to_string(enum ofperr error)
  {
      return (ofperr_is_valid(error)
              ? ofperr_get_name(error)
              : ovs_strerror(error));
  }
  