static void dissect_HEARTBEAT_FRAG(tvbuff_t *tvb, packet_info *pinfo, gint offset, guint8 flags,
                const guint encoding, int octets_to_next_header, proto_tree *tree, endpoint_guid *guid) {
  /*
   * 0...2...........7...............15.............23...............31
   * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   * |HEARTBEAT_FRAG |X|X|X|X|X|X|X|E|      octetsToNextHeader       |
   * +---------------+---------------+---------------+---------------+
   * | EntityId readerEntityId                                       |
   * +---------------+---------------+---------------+---------------+
   * | EntityId writerEntityId                                       |
   * +---------------+---------------+---------------+---------------+
   * |                                                               |
   * + SequenceNumber writerSeqNumber                                +
   * |                                                               |
   * +---------------+---------------+---------------+---------------+
   * | FragmentNumber lastFragmentNum                                |
   * +---------------+---------------+---------------+---------------+
   * | Counter count                                                 |
   * +---------------+---------------+---------------+---------------+
   */
  proto_item *octet_item;
  guint32 wid;
  proto_tree_add_bitmask_value(tree, tvb, offset + 1, hf_rtps_sm_flags, ett_rtps_flags, HEARTBEAT_FRAG_FLAGS, flags);

  octet_item = proto_tree_add_item(tree, hf_rtps_sm_octets_to_next_header, tvb,
                        offset + 2, 2, encoding);

  if (octets_to_next_header < 24) {
    expert_add_info_format(pinfo, octet_item, &ei_rtps_sm_octets_to_next_header_error, "(Error: should be >= 24)");
    return;
  }

  /* Skip decoding the entire packet if (tree == NULL) */
  if (tree == NULL) {
    return;
  }

  offset += 4;

  /* readerEntityId */
  rtps_util_add_entity_id(tree, tvb, offset, hf_rtps_sm_rdentity_id, hf_rtps_sm_rdentity_id_key,
                        hf_rtps_sm_rdentity_id_kind, ett_rtps_rdentity, "readerEntityId", NULL);
  offset += 4;

  /* writerEntityId */
  rtps_util_add_entity_id(tree, tvb, offset, hf_rtps_sm_wrentity_id, hf_rtps_sm_wrentity_id_key,
                        hf_rtps_sm_wrentity_id_kind, ett_rtps_wrentity, "writerEntityId", &wid);
  offset += 4;
  guid->entity_id = wid;
  guid->fields_present |= GUID_HAS_ENTITY_ID;
  rtps_util_topic_info_add_tree(tree, tvb, offset, guid);

  /* First available Sequence Number */
  rtps_util_add_seq_number(tree, tvb, offset, encoding, "writerSeqNumber");
  offset += 8;

  /* Fragment number */
  proto_tree_add_item(tree, hf_rtps_heartbeat_frag_number, tvb, offset, 4, encoding);
  offset += 4;

  /* Counter */
  proto_tree_add_item(tree, hf_rtps_heartbeat_frag_count, tvb, offset, 4, encoding);
}
static void dissect_HEARTBEAT_FRAG(tvbuff_t *tvb, packet_info *pinfo, gint offset, guint8 flags,
                const guint encoding, int octets_to_next_header, proto_tree *tree, endpoint_guid *guid) {
   
  proto_item *octet_item;
  guint32 wid;
  proto_tree_add_bitmask_value(tree, tvb, offset + 1, hf_rtps_sm_flags, ett_rtps_flags, HEARTBEAT_FRAG_FLAGS, flags);

  octet_item = proto_tree_add_item(tree, hf_rtps_sm_octets_to_next_header, tvb,
                        offset + 2, 2, encoding);

  if (octets_to_next_header < 24) {
    expert_add_info_format(pinfo, octet_item, &ei_rtps_sm_octets_to_next_header_error, "(Error: should be >= 24)");
    return;
  }

   
  if (tree == NULL) {
    return;
  }

  offset += 4;

   
  rtps_util_add_entity_id(tree, tvb, offset, hf_rtps_sm_rdentity_id, hf_rtps_sm_rdentity_id_key,
                        hf_rtps_sm_rdentity_id_kind, ett_rtps_rdentity, "readerEntityId", NULL);
  offset += 4;

   
  rtps_util_add_entity_id(tree, tvb, offset, hf_rtps_sm_wrentity_id, hf_rtps_sm_wrentity_id_key,
                        hf_rtps_sm_wrentity_id_kind, ett_rtps_wrentity, "writerEntityId", &wid);
  offset += 4;
  guid->entity_id = wid;
  guid->fields_present |= GUID_HAS_ENTITY_ID;
  rtps_util_topic_info_add_tree(tree, tvb, offset, guid);

   
  rtps_util_add_seq_number(tree, tvb, offset, encoding, "writerSeqNumber");
  offset += 8;

   
  proto_tree_add_item(tree, hf_rtps_heartbeat_frag_number, tvb, offset, 4, encoding);
  offset += 4;

   
  proto_tree_add_item(tree, hf_rtps_heartbeat_frag_count, tvb, offset, 4, encoding);
}