text: /*
   * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2014 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 <ctype.h>
  #include <errno.h>
  #include <getopt.h>
  #include <inttypes.h>
  #include <sys/socket.h>
  #include <net/if.h>
  #include <signal.h>
  #include <stdlib.h>
  #include <string.h>
  #include <unistd.h>
  #include <fcntl.h>
  #include <sys/stat.h>
  #include <sys/time.h>
  
  #include "byte-order.h"
  #include "classifier.h"
  #include "command-line.h"
  #include "daemon.h"
  #include "compiler.h"
  #include "dirs.h"
  #include "dynamic-string.h"
  #include "fatal-signal.h"
  #include "nx-match.h"
  #include "odp-util.h"
  #include "ofp-actions.h"
  #include "ofp-errors.h"
  #include "ofp-msgs.h"
  #include "ofp-parse.h"
  #include "ofp-print.h"
  #include "ofp-util.h"
  #include "ofp-version-opt.h"
  #include "ofpbuf.h"
  #include "ofproto/ofproto.h"
  #include "openflow/nicira-ext.h"
  #include "openflow/openflow.h"
  #include "packets.h"
  #include "pcap-file.h"
  #include "poll-loop.h"
  #include "random.h"
  #include "stream-ssl.h"
  #include "socket-util.h"
  #include "timeval.h"
  #include "unixctl.h"
  #include "util.h"
  #include "openvswitch/vconn.h"
  #include "openvswitch/vlog.h"
  #include "meta-flow.h"
  #include "sort.h"
  
  VLOG_DEFINE_THIS_MODULE(ofctl);
  
  /* --strict: Use strict matching for flow mod commands?  Additionally governs
   * use of nx_pull_match() instead of nx_pull_match_loose() in parse-nx-match.
   */
  static bool strict;
  
  /* --readd: If true, on replace-flows, re-add even flows that have not changed
   * (to reset flow counters). */
  static bool readd;
  
  /* -F, --flow-format: Allowed protocols.  By default, any protocol is
   * allowed. */
  static enum ofputil_protocol allowed_protocols = OFPUTIL_P_ANY;
  
  /* -P, --packet-in-format: Packet IN format to use in monitor and snoop
   * commands.  Either one of NXPIF_* to force a particular packet_in format, or
   * -1 to let ovs-ofctl choose the default. */
  static int preferred_packet_in_format = -1;
  
  /* -m, --more: Additional verbosity for ofp-print functions. */
  static int verbosity;
  
  /* --timestamp: Print a timestamp before each received packet on "monitor" and
   * "snoop" command? */
  static bool timestamp;
  
  /* --unixctl-path: Path to use for unixctl server, for "monitor" and "snoop"
       commands. */
  static char *unixctl_path;
  
  /* --sort, --rsort: Sort order. */
  enum sort_order { SORT_ASC, SORT_DESC };
  struct sort_criterion {
      const struct mf_field *field; /* NULL means to sort by priority. */
      enum sort_order order;
  };
  static struct sort_criterion *criteria;
  static size_t n_criteria, allocated_criteria;
  
  static const struct command *get_all_commands(void);
  
  OVS_NO_RETURN static void usage(void);
  static void parse_options(int argc, char *argv[]);
  
  static bool recv_flow_stats_reply(struct vconn *, ovs_be32 send_xid,
                                    struct ofpbuf **replyp,
                                    struct ofputil_flow_stats *,
                                    struct ofpbuf *ofpacts);
  int
  main(int argc, char *argv[])
  {
      set_program_name(argv[0]);
      service_start(&argc, &argv);
      parse_options(argc, argv);
      fatal_ignore_sigpipe();
      run_command(argc - optind, argv + optind, get_all_commands());
      return 0;
  }
  
  static void
  add_sort_criterion(enum sort_order order, const char *field)
  {
      struct sort_criterion *sc;
  
      if (n_criteria >= allocated_criteria) {
          criteria = x2nrealloc(criteria, &allocated_criteria, sizeof *criteria);
      }
  
      sc = &criteria[n_criteria++];
      if (!field || !strcasecmp(field, "priority")) {
          sc->field = NULL;
      } else {
          sc->field = mf_from_name(field);
          if (!sc->field) {
              ovs_fatal(0, "%s: unknown field name", field);
          }
      }
      sc->order = order;
  }
  
  static void
  parse_options(int argc, char *argv[])
  {
      enum {
          OPT_STRICT = UCHAR_MAX + 1,
          OPT_READD,
          OPT_TIMESTAMP,
          OPT_SORT,
          OPT_RSORT,
          OPT_UNIXCTL,
          DAEMON_OPTION_ENUMS,
          OFP_VERSION_OPTION_ENUMS,
          VLOG_OPTION_ENUMS
      };
      static const struct option long_options[] = {
          {"timeout", required_argument, NULL, 't'},
          {"strict", no_argument, NULL, OPT_STRICT},
          {"readd", no_argument, NULL, OPT_READD},
          {"flow-format", required_argument, NULL, 'F'},
          {"packet-in-format", required_argument, NULL, 'P'},
          {"more", no_argument, NULL, 'm'},
          {"timestamp", no_argument, NULL, OPT_TIMESTAMP},
          {"sort", optional_argument, NULL, OPT_SORT},
          {"rsort", optional_argument, NULL, OPT_RSORT},
          {"unixctl",     required_argument, NULL, OPT_UNIXCTL},
          {"help", no_argument, NULL, 'h'},
          {"option", no_argument, NULL, 'o'},
          DAEMON_LONG_OPTIONS,
          OFP_VERSION_LONG_OPTIONS,
          VLOG_LONG_OPTIONS,
          STREAM_SSL_LONG_OPTIONS,
          {NULL, 0, NULL, 0},
      };
      char *short_options = long_options_to_short_options(long_options);
      uint32_t versions;
      enum ofputil_protocol version_protocols;
  
      /* For now, ovs-ofctl only enables OpenFlow 1.0 by default.  This is
       * because ovs-ofctl implements command such as "add-flow" as raw OpenFlow
       * requests, but those requests have subtly different semantics in
       * different OpenFlow versions.  For example:
       *
       *     - In OpenFlow 1.0, a "mod-flow" operation that does not find any
       *       existing flow to modify adds a new flow.
       *
       *     - In OpenFlow 1.1, a "mod-flow" operation that does not find any
       *       existing flow to modify adds a new flow, but only if the mod-flow
       *       did not match on the flow cookie.
       *
       *     - In OpenFlow 1.2 and a later, a "mod-flow" operation never adds a
       *       new flow.
       */
      set_allowed_ofp_versions("OpenFlow10");
  
      for (;;) {
          unsigned long int timeout;
          int c;
  
          c = getopt_long(argc, argv, short_options, long_options, NULL);
          if (c == -1) {
              break;
          }
  
          switch (c) {
          case 't':
              timeout = strtoul(optarg, NULL, 10);
              if (timeout <= 0) {
                  ovs_fatal(0, "value %s on -t or --timeout is not at least 1",
                            optarg);
              } else {
                  time_alarm(timeout);
              }
              break;
  
          case 'F':
              allowed_protocols = ofputil_protocols_from_string(optarg);
              if (!allowed_protocols) {
                  ovs_fatal(0, "%s: invalid flow format(s)", optarg);
              }
              break;
  
          case 'P':
              preferred_packet_in_format =
                  ofputil_packet_in_format_from_string(optarg);
              if (preferred_packet_in_format < 0) {
                  ovs_fatal(0, "unknown packet-in format `%s'", optarg);
              }
              break;
  
          case 'm':
              verbosity++;
              break;
  
          case 'h':
              usage();
  
          case 'o':
              print_options(long_options);
              exit(EXIT_SUCCESS);
  
          case OPT_STRICT:
              strict = true;
              break;
  
          case OPT_READD:
              readd = true;
              break;
  
          case OPT_TIMESTAMP:
              timestamp = true;
              break;
  
          case OPT_SORT:
              add_sort_criterion(SORT_ASC, optarg);
              break;
  
          case OPT_RSORT:
              add_sort_criterion(SORT_DESC, optarg);
              break;
  
          case OPT_UNIXCTL:
              unixctl_path = optarg;
              break;
  
          DAEMON_OPTION_HANDLERS
          OFP_VERSION_OPTION_HANDLERS
          VLOG_OPTION_HANDLERS
          STREAM_SSL_OPTION_HANDLERS
  
          case '?':
              exit(EXIT_FAILURE);
  
          default:
              abort();
          }
      }
  
      if (n_criteria) {
          /* Always do a final sort pass based on priority. */
          add_sort_criterion(SORT_DESC, "priority");
      }
  
      free(short_options);
  
      versions = get_allowed_ofp_versions();
      version_protocols = ofputil_protocols_from_version_bitmap(versions);
      if (!(allowed_protocols & version_protocols)) {
          char *protocols = ofputil_protocols_to_string(allowed_protocols);
          struct ds version_s = DS_EMPTY_INITIALIZER;
  
          ofputil_format_version_bitmap_names(&version_s, versions);
          ovs_fatal(0, "None of the enabled OpenFlow versions (%s) supports "
                    "any of the enabled flow formats (%s).  (Use -O to enable "
                    "additional OpenFlow versions or -F to enable additional "
                    "flow formats.)", ds_cstr(&version_s), protocols);
      }
      allowed_protocols &= version_protocols;
      mask_allowed_ofp_versions(ofputil_protocols_to_version_bitmap(
                                    allowed_protocols));
  }
  
  static void
  usage(void)
  {
      printf("%s: OpenFlow switch management utility\n"
             "usage: %s [OPTIONS] COMMAND [ARG...]\n"
             "\nFor OpenFlow switches:\n"
             "  show SWITCH                 show OpenFlow information\n"
             "  dump-desc SWITCH            print switch description\n"
             "  dump-tables SWITCH          print table stats\n"
             "  dump-table-features SWITCH  print table features\n"
             "  mod-port SWITCH IFACE ACT   modify port behavior\n"
             "  mod-table SWITCH MOD        modify flow table behavior\n"
             "  get-frags SWITCH            print fragment handling behavior\n"
             "  set-frags SWITCH FRAG_MODE  set fragment handling behavior\n"
             "  dump-ports SWITCH [PORT]    print port statistics\n"
             "  dump-ports-desc SWITCH [PORT]  print port descriptions\n"
             "  dump-flows SWITCH           print all flow entries\n"
             "  dump-flows SWITCH FLOW      print matching FLOWs\n"
             "  dump-aggregate SWITCH       print aggregate flow statistics\n"
             "  dump-aggregate SWITCH FLOW  print aggregate stats for FLOWs\n"
             "  queue-stats SWITCH [PORT [QUEUE]]  dump queue stats\n"
             "  add-flow SWITCH FLOW        add flow described by FLOW\n"
             "  add-flows SWITCH FILE       add flows from FILE\n"
             "  mod-flows SWITCH FLOW       modify actions of matching FLOWs\n"
             "  del-flows SWITCH [FLOW]     delete matching FLOWs\n"
             "  replace-flows SWITCH FILE   replace flows with those in FILE\n"
             "  diff-flows SOURCE1 SOURCE2  compare flows from two sources\n"
             "  packet-out SWITCH IN_PORT ACTIONS PACKET...\n"
             "                              execute ACTIONS on PACKET\n"
             "  monitor SWITCH [MISSLEN] [invalid_ttl] [watch:[...]]\n"
             "                              print packets received from SWITCH\n"
             "  snoop SWITCH                snoop on SWITCH and its controller\n"
             "  add-group SWITCH GROUP      add group described by GROUP\n"
             "  add-groups SWITCH FILE      add group from FILE\n"
             "  mod-group SWITCH GROUP      modify specific group\n"
             "  del-groups SWITCH [GROUP]   delete matching GROUPs\n"
             "  insert-buckets SWITCH [GROUP] add buckets to GROUP\n"
             "  remove-buckets SWITCH [GROUP] remove buckets from GROUP\n"
             "  dump-group-features SWITCH  print group features\n"
             "  dump-groups SWITCH [GROUP]  print group description\n"
             "  dump-group-stats SWITCH [GROUP]  print group statistics\n"
             "  queue-get-config SWITCH PORT  print queue information for port\n"
             "  add-meter SWITCH METER      add meter described by METER\n"
             "  mod-meter SWITCH METER      modify specific METER\n"
             "  del-meter SWITCH METER      delete METER\n"
             "  del-meters SWITCH           delete all meters\n"
             "  dump-meter SWITCH METER     print METER configuration\n"
             "  dump-meters SWITCH          print all meter configuration\n"
             "  meter-stats SWITCH [METER]  print meter statistics\n"
             "  meter-features SWITCH       print meter features\n"
             "\nFor OpenFlow switches and controllers:\n"
             "  probe TARGET                probe whether TARGET is up\n"
             "  ping TARGET [N]             latency of N-byte echos\n"
             "  benchmark TARGET N COUNT    bandwidth of COUNT N-byte echos\n"
             "SWITCH or TARGET is an active OpenFlow connection method.\n"
             "\nOther commands:\n"
             "  ofp-parse FILE              print messages read from FILE\n"
             "  ofp-parse-pcap PCAP         print OpenFlow read from PCAP\n",
             program_name, program_name);
      vconn_usage(true, false, false);
      daemon_usage();
      ofp_version_usage();
      vlog_usage();
      printf("\nOther options:\n"
             "  --strict                    use strict match for flow commands\n"
             "  --readd                     replace flows that haven't changed\n"
             "  -F, --flow-format=FORMAT    force particular flow format\n"
             "  -P, --packet-in-format=FRMT force particular packet in format\n"
             "  -m, --more                  be more verbose printing OpenFlow\n"
             "  --timestamp                 (monitor, snoop) print timestamps\n"
             "  -t, --timeout=SECS          give up after SECS seconds\n"
             "  --sort[=field]              sort in ascending order\n"
             "  --rsort[=field]             sort in descending order\n"
             "  --unixctl=SOCKET            set control socket name\n"
             "  -h, --help                  display this help message\n"
             "  -V, --version               display version information\n");
      exit(EXIT_SUCCESS);
  }
  
  static void
  ofctl_exit(struct unixctl_conn *conn, int argc OVS_UNUSED,
             const char *argv[] OVS_UNUSED, void *exiting_)
  {
      bool *exiting = exiting_;
      *exiting = true;
      unixctl_command_reply(conn, NULL);
  }
  
  static void run(int retval, const char *message, ...)
      OVS_PRINTF_FORMAT(2, 3);
  
  static void
  run(int retval, const char *message, ...)
  {
      if (retval) {
          va_list args;
  
          va_start(args, message);
          ovs_fatal_valist(retval, message, args);
      }
  }
  
  /* Generic commands. */
  
  static int
  open_vconn_socket(const char *name, struct vconn **vconnp)
  {
      char *vconn_name = xasprintf("unix:%s", name);
      int error;
  
      error = vconn_open(vconn_name, get_allowed_ofp_versions(), DSCP_DEFAULT,
                         vconnp);
      if (error && error != ENOENT) {
          ovs_fatal(0, "%s: failed to open socket (%s)", name,
                    ovs_strerror(error));
      }
      free(vconn_name);
  
      return error;
  }
  
  enum open_target { MGMT, SNOOP };
  
  static enum ofputil_protocol
  open_vconn__(const char *name, enum open_target target,
               struct vconn **vconnp)
  {
      const char *suffix = target == MGMT ? "mgmt" : "snoop";
      char *datapath_name, *datapath_type, *socket_name;
      enum ofputil_protocol protocol;
      char *bridge_path;
      int ofp_version;
      int error;
  
      bridge_path = xasprintf("%s/%s.%s", ovs_rundir(), name, suffix);
  
      ofproto_parse_name(name, &datapath_name, &datapath_type);
      socket_name = xasprintf("%s/%s.%s", ovs_rundir(), datapath_name, suffix);
      free(datapath_name);
      free(datapath_type);
  
      if (strchr(name, ':')) {
          run(vconn_open(name, get_allowed_ofp_versions(), DSCP_DEFAULT, vconnp),
              "connecting to %s", name);
      } else if (!open_vconn_socket(name, vconnp)) {
          /* Fall Through. */
      } else if (!open_vconn_socket(bridge_path, vconnp)) {
          /* Fall Through. */
      } else if (!open_vconn_socket(socket_name, vconnp)) {
          /* Fall Through. */
      } else {
          ovs_fatal(0, "%s is not a bridge or a socket", name);
      }
  
      if (target == SNOOP) {
          vconn_set_recv_any_version(*vconnp);
      }
  
      free(bridge_path);
      free(socket_name);
  
      VLOG_DBG("connecting to %s", vconn_get_name(*vconnp));
      error = vconn_connect_block(*vconnp);
      if (error) {
          ovs_fatal(0, "%s: failed to connect to socket (%s)", name,
                    ovs_strerror(error));
      }
  
      ofp_version = vconn_get_version(*vconnp);
      protocol = ofputil_protocol_from_ofp_version(ofp_version);
      if (!protocol) {
          ovs_fatal(0, "%s: unsupported OpenFlow version 0x%02x",
                    name, ofp_version);
      }
      return protocol;
  }
  
  static enum ofputil_protocol
  open_vconn(const char *name, struct vconn **vconnp)
  {
      return open_vconn__(name, MGMT, vconnp);
  }
  
  static void
  send_openflow_buffer(struct vconn *vconn, struct ofpbuf *buffer)
  {
      ofpmsg_update_length(buffer);
      run(vconn_send_block(vconn, buffer), "failed to send packet to switch");
  }
  
  static void
  dump_transaction(struct vconn *vconn, struct ofpbuf *request)
  {
      struct ofpbuf *reply;
  
      ofpmsg_update_length(request);
      run(vconn_transact(vconn, request, &reply), "talking to %s",
          vconn_get_name(vconn));
      ofp_print(stdout, ofpbuf_data(reply), ofpbuf_size(reply), verbosity + 1);
      ofpbuf_delete(reply);
  }
  
  static void
  dump_trivial_transaction(const char *vconn_name, enum ofpraw raw)
  {
      struct ofpbuf *request;
      struct vconn *vconn;
  
      open_vconn(vconn_name, &vconn);
      request = ofpraw_alloc(raw, vconn_get_version(vconn), 0);
      dump_transaction(vconn, request);
      vconn_close(vconn);
  }
  
  static void
  dump_stats_transaction(struct vconn *vconn, struct ofpbuf *request)
  {
      const struct ofp_header *request_oh = ofpbuf_data(request);
      ovs_be32 send_xid = request_oh->xid;
      enum ofpraw request_raw;
      enum ofpraw reply_raw;
      bool done = false;
  
      ofpraw_decode_partial(&request_raw, ofpbuf_data(request), ofpbuf_size(request));
      reply_raw = ofpraw_stats_request_to_reply(request_raw,
                                                request_oh->version);
  
      send_openflow_buffer(vconn, request);
      while (!done) {
          ovs_be32 recv_xid;
          struct ofpbuf *reply;
  
          run(vconn_recv_block(vconn, &reply), "OpenFlow packet receive failed");
          recv_xid = ((struct ofp_header *) ofpbuf_data(reply))->xid;
          if (send_xid == recv_xid) {
              enum ofpraw raw;
  
              ofp_print(stdout, ofpbuf_data(reply), ofpbuf_size(reply), verbosity + 1);
  
              ofpraw_decode(&raw, ofpbuf_data(reply));
              if (ofptype_from_ofpraw(raw) == OFPTYPE_ERROR) {
                  done = true;
              } else if (raw == reply_raw) {
                  done = !ofpmp_more(ofpbuf_data(reply));
              } else {
                  ovs_fatal(0, "received bad reply: %s",
                            ofp_to_string(ofpbuf_data(reply), ofpbuf_size(reply),
                                          verbosity + 1));
              }
          } else {
              VLOG_DBG("received reply with xid %08"PRIx32" "
                       "!= expected %08"PRIx32, recv_xid, send_xid);
          }
          ofpbuf_delete(reply);
      }
  }
  
  static void
  dump_trivial_stats_transaction(const char *vconn_name, enum ofpraw raw)
  {
      struct ofpbuf *request;
      struct vconn *vconn;
  
      open_vconn(vconn_name, &vconn);
      request = ofpraw_alloc(raw, vconn_get_version(vconn), 0);
      dump_stats_transaction(vconn, request);
      vconn_close(vconn);
  }
  
  /* Sends all of the 'requests', which should be requests that only have replies
   * if an error occurs, and waits for them to succeed or fail.  If an error does
   * occur, prints it and exits with an error.
   *
   * Destroys all of the 'requests'. */
  static void
  transact_multiple_noreply(struct vconn *vconn, struct ovs_list *requests)
  {
      struct ofpbuf *request, *reply;
  
      LIST_FOR_EACH (request, list_node, requests) {
          ofpmsg_update_length(request);
      }
  
      run(vconn_transact_multiple_noreply(vconn, requests, &reply),
          "talking to %s", vconn_get_name(vconn));
      if (reply) {
          ofp_print(stderr, ofpbuf_data(reply), ofpbuf_size(reply), verbosity + 2);
          exit(1);
      }
      ofpbuf_delete(reply);
  }
  
  /* Sends 'request', which should be a request that only has a reply if an error
   * occurs, and waits for it to succeed or fail.  If an error does occur, prints
   * it and exits with an error.
   *
   * Destroys 'request'. */
  static void
  transact_noreply(struct vconn *vconn, struct ofpbuf *request)
  {
      struct ovs_list requests;
  
      list_init(&requests);
      list_push_back(&requests, &request->list_node);
      transact_multiple_noreply(vconn, &requests);
  }
  
  static void
  fetch_switch_config(struct vconn *vconn, struct ofp_switch_config *config_)
  {
      struct ofp_switch_config *config;
      struct ofpbuf *request;
      struct ofpbuf *reply;
      enum ofptype type;
  
      request = ofpraw_alloc(OFPRAW_OFPT_GET_CONFIG_REQUEST,
                             vconn_get_version(vconn), 0);
      run(vconn_transact(vconn, request, &reply),
          "talking to %s", vconn_get_name(vconn));
  
      if (ofptype_pull(&type, reply) || type != OFPTYPE_GET_CONFIG_REPLY) {
          ovs_fatal(0, "%s: bad reply to config request", vconn_get_name(vconn));
      }
  
      config = ofpbuf_pull(reply, sizeof *config);
      *config_ = *config;
  
      ofpbuf_delete(reply);
  }
  
  static void
  set_switch_config(struct vconn *vconn, const struct ofp_switch_config *config)
  {
      struct ofpbuf *request;
  
      request = ofpraw_alloc(OFPRAW_OFPT_SET_CONFIG, vconn_get_version(vconn), 0);
      ofpbuf_put(request, config, sizeof *config);
  
      transact_noreply(vconn, request);
  }
  
  static void
  ofctl_show(int argc OVS_UNUSED, char *argv[])
  {
      const char *vconn_name = argv[1];
      enum ofp_version version;
      struct vconn *vconn;
      struct ofpbuf *request;
      struct ofpbuf *reply;
      bool has_ports;
  
      open_vconn(vconn_name, &vconn);
      version = vconn_get_version(vconn);
      request = ofpraw_alloc(OFPRAW_OFPT_FEATURES_REQUEST, version, 0);
      run(vconn_transact(vconn, request, &reply), "talking to %s", vconn_name);
  
      has_ports = ofputil_switch_features_has_ports(reply);
      ofp_print(stdout, ofpbuf_data(reply), ofpbuf_size(reply), verbosity + 1);
      ofpbuf_delete(reply);
  
      if (!has_ports) {
          request = ofputil_encode_port_desc_stats_request(version, OFPP_ANY);
          dump_stats_transaction(vconn, request);
      }
      dump_trivial_transaction(vconn_name, OFPRAW_OFPT_GET_CONFIG_REQUEST);
      vconn_close(vconn);
  }
  
  static void
  ofctl_dump_desc(int argc OVS_UNUSED, char *argv[])
  {
      dump_trivial_stats_transaction(argv[1], OFPRAW_OFPST_DESC_REQUEST);
  }
  
  static void
  ofctl_dump_tables(int argc OVS_UNUSED, char *argv[])
  {
      dump_trivial_stats_transaction(argv[1], OFPRAW_OFPST_TABLE_REQUEST);
  }
  
  static void
  ofctl_dump_table_features(int argc OVS_UNUSED, char *argv[])
  {
      struct ofpbuf *request;
      struct vconn *vconn;
  
      open_vconn(argv[1], &vconn);
      request = ofputil_encode_table_features_request(vconn_get_version(vconn));
      if (request) {
          dump_stats_transaction(vconn, request);
      }
  
      vconn_close(vconn);
  }
  
  static bool fetch_port_by_stats(struct vconn *,
                                  const char *port_name, ofp_port_t port_no,
                                  struct ofputil_phy_port *);
  
  /* Uses OFPT_FEATURES_REQUEST to attempt to fetch information about the port
   * named 'port_name' or numbered 'port_no' into '*pp'.  Returns true if
   * successful, false on failure.
   *
   * This is only appropriate for OpenFlow 1.0, 1.1, and 1.2, which include a
   * list of ports in OFPT_FEATURES_REPLY. */
  static bool
  fetch_port_by_features(struct vconn *vconn,
                         const char *port_name, ofp_port_t port_no,
                         struct ofputil_phy_port *pp)
  {
      struct ofputil_switch_features features;
      const struct ofp_header *oh;
      struct ofpbuf *request, *reply;
      enum ofperr error;
      enum ofptype type;
      struct ofpbuf b;
      bool found = false;
  
      /* Fetch the switch's ofp_switch_features. */
      request = ofpraw_alloc(OFPRAW_OFPT_FEATURES_REQUEST,
                             vconn_get_version(vconn), 0);
      run(vconn_transact(vconn, request, &reply),
          "talking to %s", vconn_get_name(vconn));
  
      oh = ofpbuf_data(reply);
      if (ofptype_decode(&type, ofpbuf_data(reply))
          || type != OFPTYPE_FEATURES_REPLY) {
          ovs_fatal(0, "%s: received bad features reply", vconn_get_name(vconn));
      }
      if (!ofputil_switch_features_has_ports(reply)) {
          /* The switch features reply does not contain a complete list of ports.
           * Probably, there are more ports than will fit into a single 64 kB
           * OpenFlow message.  Use OFPST_PORT_DESC to get a complete list of
           * ports. */
          ofpbuf_delete(reply);
          return fetch_port_by_stats(vconn, port_name, port_no, pp);
      }
  
      error = ofputil_decode_switch_features(oh, &features, &b);
      if (error) {
          ovs_fatal(0, "%s: failed to decode features reply (%s)",
                    vconn_get_name(vconn), ofperr_to_string(error));
      }
  
      while (!ofputil_pull_phy_port(oh->version, &b, pp)) {
          if (port_no != OFPP_NONE
              ? port_no == pp->port_no
              : !strcmp(pp->name, port_name)) {
              found = true;
              break;
          }
      }
      ofpbuf_delete(reply);
      return found;
  }
  
  /* Uses a OFPST_PORT_DESC request to attempt to fetch information about the
   * port named 'port_name' or numbered 'port_no' into '*pp'.  Returns true if
   * successful, false on failure.
   *
   * This is most appropriate for OpenFlow 1.3 and later.  Open vSwitch 1.7 and
   * later also implements OFPST_PORT_DESC, as an extension, for OpenFlow 1.0,
   * 1.1, and 1.2, so this can be used as a fallback in those versions when there
   * are too many ports than fit in an OFPT_FEATURES_REPLY. */
  static bool
  fetch_port_by_stats(struct vconn *vconn,
                      const char *port_name, ofp_port_t port_no,
                      struct ofputil_phy_port *pp)
  {
      struct ofpbuf *request;
      ovs_be32 send_xid;
      bool done = false;
      bool found = false;
  
      request = ofputil_encode_port_desc_stats_request(vconn_get_version(vconn),
                                                       port_no);
      send_xid = ((struct ofp_header *) ofpbuf_data(request))->xid;
  
      send_openflow_buffer(vconn, request);
      while (!done) {
          ovs_be32 recv_xid;
          struct ofpbuf *reply;
  
          run(vconn_recv_block(vconn, &reply), "OpenFlow packet receive failed");
          recv_xid = ((struct ofp_header *) ofpbuf_data(reply))->xid;
          if (send_xid == recv_xid) {
              struct ofp_header *oh = ofpbuf_data(reply);
              enum ofptype type;
              struct ofpbuf b;
              uint16_t flags;
  
              ofpbuf_use_const(&b, oh, ntohs(oh->length));
              if (ofptype_pull(&type, &b)
                  || type != OFPTYPE_PORT_DESC_STATS_REPLY) {
                  ovs_fatal(0, "received bad reply: %s",
                            ofp_to_string(ofpbuf_data(reply), ofpbuf_size(reply),
                                          verbosity + 1));
              }
  
              flags = ofpmp_flags(oh);
              done = !(flags & OFPSF_REPLY_MORE);
  
              if (found) {
                  /* We've already found the port, but we need to drain
                   * the queue of any other replies for this request. */
                  continue;
              }
  
              while (!ofputil_pull_phy_port(oh->version, &b, pp)) {
                  if (port_no != OFPP_NONE ? port_no == pp->port_no
                                           : !strcmp(pp->name, port_name)) {
                      found = true;
                      break;
                  }
              }
          } else {
              VLOG_DBG("received reply with xid %08"PRIx32" "
                       "!= expected %08"PRIx32, recv_xid, send_xid);
          }
          ofpbuf_delete(reply);
      }
  
      return found;
  }
  
  static bool
  str_to_ofp(const char *s, ofp_port_t *ofp_port)
  {
      bool ret;
      uint32_t port_;
  
      ret = str_to_uint(s, 10, &port_);
      *ofp_port = u16_to_ofp(port_);
      return ret;
  }
  
  /* Opens a connection to 'vconn_name', fetches the port structure for
   * 'port_name' (which may be a port name or number), and copies it into
   * '*pp'. */
  static void
  fetch_ofputil_phy_port(const char *vconn_name, const char *port_name,
                         struct ofputil_phy_port *pp)
  {
      struct vconn *vconn;
      ofp_port_t port_no;
      bool found;
  
      /* Try to interpret the argument as a port number. */
      if (!str_to_ofp(port_name, &port_no)) {
          port_no = OFPP_NONE;
      }
  
      /* OpenFlow 1.0, 1.1, and 1.2 put the list of ports in the
       * OFPT_FEATURES_REPLY message.  OpenFlow 1.3 and later versions put it
       * into the OFPST_PORT_DESC reply.  Try it the correct way. */
      open_vconn(vconn_name, &vconn);
      found = (vconn_get_version(vconn) < OFP13_VERSION
               ? fetch_port_by_features(vconn, port_name, port_no, pp)
               : fetch_port_by_stats(vconn, port_name, port_no, pp));
      vconn_close(vconn);
  
      if (!found) {
          ovs_fatal(0, "%s: couldn't find port `%s'", vconn_name, port_name);
      }
  }
  
  /* Returns the port number corresponding to 'port_name' (which may be a port
   * name or number) within the switch 'vconn_name'. */
  static ofp_port_t
  str_to_port_no(const char *vconn_name, const char *port_name)
  {
      ofp_port_t port_no;
  
      if (ofputil_port_from_string(port_name, &port_no)) {
          return port_no;
      } else {
          struct ofputil_phy_port pp;
  
          fetch_ofputil_phy_port(vconn_name, port_name, &pp);
          return pp.port_no;
      }
  }
  
  static bool
  try_set_protocol(struct vconn *vconn, enum ofputil_protocol want,
                   enum ofputil_protocol *cur)
  {
      for (;;) {
          struct ofpbuf *request, *reply;
          enum ofputil_protocol next;
  
          request = ofputil_encode_set_protocol(*cur, want, &next);
          if (!request) {
              return *cur == want;
          }
  
          run(vconn_transact_noreply(vconn, request, &reply),
              "talking to %s", vconn_get_name(vconn));
          if (reply) {
              char *s = ofp_to_string(ofpbuf_data(reply), ofpbuf_size(reply), 2);
              VLOG_DBG("%s: failed to set protocol, switch replied: %s",
                       vconn_get_name(vconn), s);
              free(s);
              ofpbuf_delete(reply);
              return false;
          }
  
          *cur = next;
      }
  }
  
  static enum ofputil_protocol
  set_protocol_for_flow_dump(struct vconn *vconn,
                             enum ofputil_protocol cur_protocol,
                             enum ofputil_protocol usable_protocols)
  {
      char *usable_s;
      int i;
  
      for (i = 0; i < ofputil_n_flow_dump_protocols; i++) {
          enum ofputil_protocol f = ofputil_flow_dump_protocols[i];
          if (f & usable_protocols & allowed_protocols
              && try_set_protocol(vconn, f, &cur_protocol)) {
              return f;
          }
      }
  
      usable_s = ofputil_protocols_to_string(usable_protocols);
      if (usable_protocols & allowed_protocols) {
          ovs_fatal(0, "switch does not support any of the usable flow "
                    "formats (%s)", usable_s);
      } else {
          char *allowed_s = ofputil_protocols_to_string(allowed_protocols);
          ovs_fatal(0, "none of the usable flow formats (%s) is among the "
                    "allowed flow formats (%s)", usable_s, allowed_s);
      }
  }
  
  static struct vconn *
  prepare_dump_flows(int argc, char *argv[], bool aggregate,
                     struct ofpbuf **requestp)
  {
      enum ofputil_protocol usable_protocols, protocol;
      struct ofputil_flow_stats_request fsr;
      struct vconn *vconn;
      char *error;
  
      error = parse_ofp_flow_stats_request_str(&fsr, aggregate,
                                               argc > 2 ? argv[2] : "",
                                               &usable_protocols);
      if (error) {
          ovs_fatal(0, "%s", error);
      }
  
      protocol = open_vconn(argv[1], &vconn);
      protocol = set_protocol_for_flow_dump(vconn, protocol, usable_protocols);
      *requestp = ofputil_encode_flow_stats_request(&fsr, protocol);
      return vconn;
  }
  
  static void
  ofctl_dump_flows__(int argc, char *argv[], bool aggregate)
  {
      struct ofpbuf *request;
      struct vconn *vconn;
  
      vconn = prepare_dump_flows(argc, argv, aggregate, &request);
      dump_stats_transaction(vconn, request);
      vconn_close(vconn);
  }
  
  static int
  compare_flows(const void *afs_, const void *bfs_)
  {
      const struct ofputil_flow_stats *afs = afs_;
      const struct ofputil_flow_stats *bfs = bfs_;
      const struct match *a = &afs->match;
      const struct match *b = &bfs->match;
      const struct sort_criterion *sc;
  
      for (sc = criteria; sc < &criteria[n_criteria]; sc++) {
          const struct mf_field *f = sc->field;
          int ret;
  
          if (!f) {
              int a_pri = afs->priority;
              int b_pri = bfs->priority;
              ret = a_pri < b_pri ? -1 : a_pri > b_pri;
          } else {
              bool ina, inb;
  
              ina = mf_are_prereqs_ok(f, &a->flow) && !mf_is_all_wild(f, &a->wc);
              inb = mf_are_prereqs_ok(f, &b->flow) && !mf_is_all_wild(f, &b->wc);
              if (ina != inb) {
                  /* Skip the test for sc->order, so that missing fields always
                   * sort to the end whether we're sorting in ascending or
                   * descending order. */
                  return ina ? -1 : 1;
              } else {
                  union mf_value aval, bval;
  
                  mf_get_value(f, &a->flow, &aval);
                  mf_get_value(f, &b->flow, &bval);
                  ret = memcmp(&aval, &bval, f->n_bytes);
              }
          }
  
          if (ret) {
              return sc->order == SORT_ASC ? ret : -ret;
          }
      }
  
      return 0;
  }
  
  static void
  ofctl_dump_flows(int argc, char *argv[])
  {
      if (!n_criteria) {
          ofctl_dump_flows__(argc, argv, false);
          return;
      } else {
          struct ofputil_flow_stats *fses;
          size_t n_fses, allocated_fses;
          struct ofpbuf *request;
          struct ofpbuf ofpacts;
          struct ofpbuf *reply;
          struct vconn *vconn;
          ovs_be32 send_xid;
          struct ds s;
          size_t i;
  
          vconn = prepare_dump_flows(argc, argv, false, &request);
          send_xid = ((struct ofp_header *) ofpbuf_data(request))->xid;
          send_openflow_buffer(vconn, request);
  
          fses = NULL;
          n_fses = allocated_fses = 0;
          reply = NULL;
          ofpbuf_init(&ofpacts, 0);
          for (;;) {
              struct ofputil_flow_stats *fs;
  
              if (n_fses >= allocated_fses) {
                  fses = x2nrealloc(fses, &allocated_fses, sizeof *fses);
              }
  
              fs = &fses[n_fses];
              if (!recv_flow_stats_reply(vconn, send_xid, &reply, fs,
                                         &ofpacts)) {
                  break;
              }
              fs->ofpacts = xmemdup(fs->ofpacts, fs->ofpacts_len);
              n_fses++;
          }
          ofpbuf_uninit(&ofpacts);
  
          qsort(fses, n_fses, sizeof *fses, compare_flows);
  
          ds_init(&s);
          for (i = 0; i < n_fses; i++) {
              ds_clear(&s);
              ofp_print_flow_stats(&s, &fses[i]);
              puts(ds_cstr(&s));
          }
          ds_destroy(&s);
  
          for (i = 0; i < n_fses; i++) {
              free(CONST_CAST(struct ofpact *, fses[i].ofpacts));
          }
          free(fses);
  
          vconn_close(vconn);
      }
  }
  
  static void
  ofctl_dump_aggregate(int argc, char *argv[])
  {
      ofctl_dump_flows__(argc, argv, true);
  }
  
  static void
  ofctl_queue_stats(int argc, char *argv[])
  {
      struct ofpbuf *request;
      struct vconn *vconn;
      struct ofputil_queue_stats_request oqs;
  
      open_vconn(argv[1], &vconn);
  
      if (argc > 2 && argv[2][0] && strcasecmp(argv[2], "all")) {
          oqs.port_no = str_to_port_no(argv[1], argv[2]);
      } else {
          oqs.port_no = OFPP_ANY;
      }
      if (argc > 3 && argv[3][0] && strcasecmp(argv[3], "all")) {
          oqs.queue_id = atoi(argv[3]);
      } else {
          oqs.queue_id = OFPQ_ALL;
      }
  
      request = ofputil_encode_queue_stats_request(vconn_get_version(vconn), &oqs);
      dump_stats_transaction(vconn, request);
      vconn_close(vconn);
  }
  
  static void
  ofctl_queue_get_config(int argc OVS_UNUSED, char *argv[])
  {
      const char *vconn_name = argv[1];
      const char *port_name = argv[2];
      enum ofputil_protocol protocol;
      enum ofp_version version;
      struct ofpbuf *request;
      struct vconn *vconn;
      ofp_port_t port;
  
      port = str_to_port_no(vconn_name, port_name);
  
      protocol = open_vconn(vconn_name, &vconn);
      version = ofputil_protocol_to_ofp_version(protocol);
      request = ofputil_encode_queue_get_config_request(version, port);
      dump_transaction(vconn, request);
      vconn_close(vconn);
  }
  
  static enum ofputil_protocol
  open_vconn_for_flow_mod(const char *remote, struct vconn **vconnp,
                          enum ofputil_protocol usable_protocols)
  {
      enum ofputil_protocol cur_protocol;
      char *usable_s;
      int i;
  
      if (!(usable_protocols & allowed_protocols)) {
          char *allowed_s = ofputil_protocols_to_string(allowed_protocols);
          usable_s = ofputil_protocols_to_string(usable_protocols);
          ovs_fatal(0, "none of the usable flow formats (%s) is among the "
                    "allowed flow formats (%s)", usable_s, allowed_s);
      }
  
      /* If the initial flow format is allowed and usable, keep it. */
      cur_protocol = open_vconn(remote, vconnp);
      if (usable_protocols & allowed_protocols & cur_protocol) {
          return cur_protocol;
      }
  
      /* Otherwise try each flow format in turn. */
      for (i = 0; i < sizeof(enum ofputil_protocol) * CHAR_BIT; i++) {
          enum ofputil_protocol f = 1 << i;
  
          if (f != cur_protocol
              && f & usable_protocols & allowed_protocols
              && try_set_protocol(*vconnp, f, &cur_protocol)) {
              return f;
          }
      }
  
      usable_s = ofputil_protocols_to_string(usable_protocols);
      ovs_fatal(0, "switch does not support any of the usable flow "
                "formats (%s)", usable_s);
  }
  
  static void
  ofctl_flow_mod__(const char *remote, struct ofputil_flow_mod *fms,
                   size_t n_fms, enum ofputil_protocol usable_protocols)
  {
      enum ofputil_protocol protocol;
      struct vconn *vconn;
      size_t i;
  
      protocol = open_vconn_for_flow_mod(remote, &vconn, usable_protocols);
  
      for (i = 0; i < n_fms; i++) {
          struct ofputil_flow_mod *fm = &fms[i];
  
          transact_noreply(vconn, ofputil_encode_flow_mod(fm, protocol));
          free(CONST_CAST(struct ofpact *, fm->ofpacts));
      }
      vconn_close(vconn);
  }
  
  static void
  ofctl_flow_mod_file(int argc OVS_UNUSED, char *argv[], uint16_t command)
  {
      enum ofputil_protocol usable_protocols;
      struct ofputil_flow_mod *fms = NULL;
      size_t n_fms = 0;
      char *error;
  
      error = parse_ofp_flow_mod_file(argv[2], command, &fms, &n_fms,
                                      &usable_protocols);
      if (error) {
          ovs_fatal(0, "%s", error);
      }
      ofctl_flow_mod__(argv[1], fms, n_fms, usable_protocols);
      free(fms);
  }
  
  static void
  ofctl_flow_mod(int argc, char *argv[], uint16_t command)
  {
      if (argc > 2 && !strcmp(argv[2], "-")) {
          ofctl_flow_mod_file(argc, argv, command);
      } else {
          struct ofputil_flow_mod fm;
          char *error;
          enum ofputil_protocol usable_protocols;
  
          error = parse_ofp_flow_mod_str(&fm, argc > 2 ? argv[2] : "", command,
                                         &usable_protocols);
          if (error) {
              ovs_fatal(0, "%s", error);
          }
          ofctl_flow_mod__(argv[1], &fm, 1, usable_protocols);
      }
  }
  
  static void
  ofctl_add_flow(int argc, char *argv[])
  {
      ofctl_flow_mod(argc, argv, OFPFC_ADD);
  }
  
  static void
  ofctl_add_flows(int argc, char *argv[])
  {
      ofctl_flow_mod_file(argc, argv, OFPFC_ADD);
  }
  
  static void
  ofctl_mod_flows(int argc, char *argv[])
  {
      ofctl_flow_mod(argc, argv, strict ? OFPFC_MODIFY_STRICT : OFPFC_MODIFY);
  }
  
  static void
  ofctl_del_flows(int argc, char *argv[])
  {
      ofctl_flow_mod(argc, argv, strict ? OFPFC_DELETE_STRICT : OFPFC_DELETE);
  }
  
  static void
  set_packet_in_format(struct vconn *vconn,
                       enum nx_packet_in_format packet_in_format)
  {
      struct ofpbuf *spif;
  
      spif = ofputil_make_set_packet_in_format(vconn_get_version(vconn),
                                               packet_in_format);
      transact_noreply(vconn, spif);
      VLOG_DBG("%s: using user-specified packet in format %s",
               vconn_get_name(vconn),
               ofputil_packet_in_format_to_string(packet_in_format));
  }
  
  static int
  monitor_set_invalid_ttl_to_controller(struct vconn *vconn)
  {
      struct ofp_switch_config config;
      enum ofp_config_flags flags;
  
      fetch_switch_config(vconn, &config);
      flags = ntohs(config.flags);
      if (!(flags & OFPC_INVALID_TTL_TO_CONTROLLER)) {
          /* Set the invalid ttl config. */
          flags |= OFPC_INVALID_TTL_TO_CONTROLLER;
  
          config.flags = htons(flags);
          set_switch_config(vconn, &config);
  
          /* Then retrieve the configuration to see if it really took.  OpenFlow
           * doesn't define error reporting for bad modes, so this is all we can
           * do. */
          fetch_switch_config(vconn, &config);
          flags = ntohs(config.flags);
          if (!(flags & OFPC_INVALID_TTL_TO_CONTROLLER)) {
              ovs_fatal(0, "setting invalid_ttl_to_controller failed (this "
                        "switch probably doesn't support mode)");
              return -EOPNOTSUPP;
          }
      }
      return 0;
  }
  
  /* Converts hex digits in 'hex' to an OpenFlow message in '*msgp'.  The
   * caller must free '*msgp'.  On success, returns NULL.  On failure, returns
   * an error message and stores NULL in '*msgp'. */
  static const char *
  openflow_from_hex(const char *hex, struct ofpbuf **msgp)
  {
      struct ofp_header *oh;
      struct ofpbuf *msg;
  
      msg = ofpbuf_new(strlen(hex) / 2);
      *msgp = NULL;
  
      if (ofpbuf_put_hex(msg, hex, NULL)[0] != '\0') {
          ofpbuf_delete(msg);
          return "Trailing garbage in hex data";
      }
  
      if (ofpbuf_size(msg) < sizeof(struct ofp_header)) {
          ofpbuf_delete(msg);
          return "Message too short for OpenFlow";
      }
  
      oh = ofpbuf_data(msg);
      if (ofpbuf_size(msg) != ntohs(oh->length)) {
          ofpbuf_delete(msg);
          return "Message size does not match length in OpenFlow header";
      }
  
      *msgp = msg;
      return NULL;
  }
  
  static void
  ofctl_send(struct unixctl_conn *conn, int argc,
             const char *argv[], void *vconn_)
  {
      struct vconn *vconn = vconn_;
      struct ds reply;
      bool ok;
      int i;
  
      ok = true;
      ds_init(&reply);
      for (i = 1; i < argc; i++) {
          const char *error_msg;
          struct ofpbuf *msg;
          int error;
  
          error_msg = openflow_from_hex(argv[i], &msg);
          if (error_msg) {
              ds_put_format(&reply, "%s\n", error_msg);
              ok = false;
              continue;
          }
  
          fprintf(stderr, "send: ");
          ofp_print(stderr, ofpbuf_data(msg), ofpbuf_size(msg), verbosity);
  
          error = vconn_send_block(vconn, msg);
          if (error) {
              ofpbuf_delete(msg);
              ds_put_format(&reply, "%s\n", ovs_strerror(error));
              ok = false;
          } else {
              ds_put_cstr(&reply, "sent\n");
          }
      }
  
      if (ok) {
          unixctl_command_reply(conn, ds_cstr(&reply));
      } else {
          unixctl_command_reply_error(conn, ds_cstr(&reply));
      }
      ds_destroy(&reply);
  }
  
  struct barrier_aux {
      struct vconn *vconn;        /* OpenFlow connection for sending barrier. */
      struct unixctl_conn *conn;  /* Connection waiting for barrier response. */
  };
  
  static void
  ofctl_barrier(struct unixctl_conn *conn, int argc OVS_UNUSED,
                const char *argv[] OVS_UNUSED, void *aux_)
  {
      struct barrier_aux *aux = aux_;
      struct ofpbuf *msg;
      int error;
  
      if (aux->conn) {
          unixctl_command_reply_error(conn, "already waiting for barrier reply");
          return;
      }
  
      msg = ofputil_encode_barrier_request(vconn_get_version(aux->vconn));
      error = vconn_send_block(aux->vconn, msg);
      if (error) {
          ofpbuf_delete(msg);
          unixctl_command_reply_error(conn, ovs_strerror(error));
      } else {
          aux->conn = conn;
      }
  }
  
  static void
  ofctl_set_output_file(struct unixctl_conn *conn, int argc OVS_UNUSED,
                        const char *argv[], void *aux OVS_UNUSED)
  {
      int fd;
  
      fd = open(argv[1], O_CREAT | O_TRUNC | O_WRONLY, 0666);
      if (fd < 0) {
          unixctl_command_reply_error(conn, ovs_strerror(errno));
          return;
      }
  
      fflush(stderr);
      dup2(fd, STDERR_FILENO);
      close(fd);
      unixctl_command_reply(conn, NULL);
  }
  
  static void
  ofctl_block(struct unixctl_conn *conn, int argc OVS_UNUSED,
              const char *argv[] OVS_UNUSED, void *blocked_)
  {
      bool *blocked = blocked_;
  
      if (!*blocked) {
          *blocked = true;
          unixctl_command_reply(conn, NULL);
      } else {
          unixctl_command_reply(conn, "already blocking");
      }
  }
  
  static void
  ofctl_unblock(struct unixctl_conn *conn, int argc OVS_UNUSED,
                const char *argv[] OVS_UNUSED, void *blocked_)
  {
      bool *blocked = blocked_;
  
      if (*blocked) {
          *blocked = false;
          unixctl_command_reply(conn, NULL);
      } else {
          unixctl_command_reply(conn, "already unblocked");
      }
  }
  
  /* Prints to stdout all of the messages received on 'vconn'.
   *
   * Iff 'reply_to_echo_requests' is true, sends a reply to any echo request
   * received on 'vconn'. */
  static void
  monitor_vconn(struct vconn *vconn, bool reply_to_echo_requests)
  {
      struct barrier_aux barrier_aux = { vconn, NULL };
      struct unixctl_server *server;
      bool exiting = false;
      bool blocked = false;
      int error;
  
      daemon_save_fd(STDERR_FILENO);
      daemonize_start();
      error = unixctl_server_create(unixctl_path, &server);
      if (error) {
          ovs_fatal(error, "failed to create unixctl server");
      }
      unixctl_command_register("exit", "", 0, 0, ofctl_exit, &exiting);
      unixctl_command_register("ofctl/send", "OFMSG...", 1, INT_MAX,
                               ofctl_send, vconn);
      unixctl_command_register("ofctl/barrier", "", 0, 0,
                               ofctl_barrier, &barrier_aux);
      unixctl_command_register("ofctl/set-output-file", "FILE", 1, 1,
                               ofctl_set_output_file, NULL);
  
      unixctl_command_register("ofctl/block", "", 0, 0, ofctl_block, &blocked);
      unixctl_command_register("ofctl/unblock", "", 0, 0, ofctl_unblock,
                               &blocked);
  
      daemonize_complete();
  
      for (;;) {
          struct ofpbuf *b;
          int retval;
  
          unixctl_server_run(server);
  
          while (!blocked) {
              enum ofptype type;
  
              retval = vconn_recv(vconn, &b);
              if (retval == EAGAIN) {
                  break;
              }
              run(retval, "vconn_recv");
  
              if (timestamp) {
                  char *s = xastrftime_msec("%Y-%m-%d %H:%M:%S.###: ",
                                            time_wall_msec(), true);
                  fputs(s, stderr);
                  free(s);
              }
  
              ofptype_decode(&type, ofpbuf_data(b));
              ofp_print(stderr, ofpbuf_data(b), ofpbuf_size(b), verbosity + 2);
              fflush(stderr);
  
              switch ((int) type) {
              case OFPTYPE_BARRIER_REPLY:
                  if (barrier_aux.conn) {
                      unixctl_command_reply(barrier_aux.conn, NULL);
                      barrier_aux.conn = NULL;
                  }
                  break;
  
              case OFPTYPE_ECHO_REQUEST:
                  if (reply_to_echo_requests) {
                      struct ofpbuf *reply;
  
                      reply = make_echo_reply(ofpbuf_data(b));
                      retval = vconn_send_block(vconn, reply);
                      if (retval) {
                          ovs_fatal(retval, "failed to send echo reply");
                      }
                  }
                  break;
              }
              ofpbuf_delete(b);
          }
  
          if (exiting) {
              break;
          }
  
          vconn_run(vconn);
          vconn_run_wait(vconn);
          if (!blocked) {
              vconn_recv_wait(vconn);
          }
          unixctl_server_wait(server);
          poll_block();
      }
      vconn_close(vconn);
      unixctl_server_destroy(server);
  }
  
  static void
  ofctl_monitor(int argc, char *argv[])
  {
      struct vconn *vconn;
      int i;
      enum ofputil_protocol usable_protocols;
  
      open_vconn(argv[1], &vconn);
      for (i = 2; i < argc; i++) {
          const char *arg = argv[i];
  
          if (isdigit((unsigned char) *arg)) {
              struct ofp_switch_config config;
  
              fetch_switch_config(vconn, &config);
              config.miss_send_len = htons(atoi(arg));
              set_switch_config(vconn, &config);
          } else if (!strcmp(arg, "invalid_ttl")) {
              monitor_set_invalid_ttl_to_controller(vconn);
          } else if (!strncmp(arg, "watch:", 6)) {
              struct ofputil_flow_monitor_request fmr;
              struct ofpbuf *msg;
              char *error;
  
              error = parse_flow_monitor_request(&fmr, arg + 6,
                                                 &usable_protocols);
              if (error) {
                  ovs_fatal(0, "%s", error);
              }
  
              msg = ofpbuf_new(0);
              ofputil_append_flow_monitor_request(&fmr, msg);
              dump_stats_transaction(vconn, msg);
              fflush(stdout);
          } else {
              ovs_fatal(0, "%s: unsupported \"monitor\" argument", arg);
          }
      }
  
      if (preferred_packet_in_format >= 0) {
          set_packet_in_format(vconn, preferred_packet_in_format);
      } else {
          enum ofp_version version = vconn_get_version(vconn);
  
          switch (version) {
          case OFP10_VERSION: {
              struct ofpbuf *spif, *reply;
  
              spif = ofputil_make_set_packet_in_format(vconn_get_version(vconn),
                                                       NXPIF_NXM);
              run(vconn_transact_noreply(vconn, spif, &reply),
                  "talking to %s", vconn_get_name(vconn));
              if (reply) {
                  char *s = ofp_to_string(ofpbuf_data(reply), ofpbuf_size(reply), 2);
                  VLOG_DBG("%s: failed to set packet in format to nxm, controller"
                          " replied: %s. Falling back to the switch default.",
                          vconn_get_name(vconn), s);
                  free(s);
                  ofpbuf_delete(reply);
              }
              break;
          }
          case OFP11_VERSION:
          case OFP12_VERSION:
          case OFP13_VERSION:
          case OFP14_VERSION:
          case OFP15_VERSION:
              break;
          default:
              OVS_NOT_REACHED();
          }
      }
  
      monitor_vconn(vconn, true);
  }
  
  static void
  ofctl_snoop(int argc OVS_UNUSED, char *argv[])
  {
      struct vconn *vconn;
  
      open_vconn__(argv[1], SNOOP, &vconn);
      monitor_vconn(vconn, false);
  }
  
  static void
  ofctl_dump_ports(int argc, char *argv[])
  {
      struct ofpbuf *request;
      struct vconn *vconn;
      ofp_port_t port;
  
      open_vconn(argv[1], &vconn);
      port = argc > 2 ? str_to_port_no(argv[1], argv[2]) : OFPP_ANY;
      request = ofputil_encode_dump_ports_request(vconn_get_version(vconn), port);
      dump_stats_transaction(vconn, request);
      vconn_close(vconn);
  }
  
  static void
  ofctl_dump_ports_desc(int argc OVS_UNUSED, char *argv[])
  {
      struct ofpbuf *request;
      struct vconn *vconn;
      ofp_port_t port;
  
      open_vconn(argv[1], &vconn);
      port = argc > 2 ? str_to_port_no(argv[1], argv[2]) : OFPP_ANY;
      request = ofputil_encode_port_desc_stats_request(vconn_get_version(vconn),
                                                       port);
      dump_stats_transaction(vconn, request);
      vconn_close(vconn);
  }
  
  static void
  ofctl_probe(int argc OVS_UNUSED, char *argv[])
  {
      struct ofpbuf *request;
      struct vconn *vconn;
      struct ofpbuf *reply;
  
      open_vconn(argv[1], &vconn);
      request = make_echo_request(vconn_get_version(vconn));
      run(vconn_transact(vconn, request, &reply), "talking to %s", argv[1]);
      if (ofpbuf_size(reply) != sizeof(struct ofp_header)) {
          ovs_fatal(0, "reply does not match request");
      }
      ofpbuf_delete(reply);
      vconn_close(vconn);
  }
  
  static void
  ofctl_packet_out(int argc, char *argv[])
  {
      enum ofputil_protocol protocol;
      struct ofputil_packet_out po;
      struct ofpbuf ofpacts;
      struct vconn *vconn;
      char *error;
      int i;
      enum ofputil_protocol usable_protocols; /* XXX: Use in proto selection */
  
      ofpbuf_init(&ofpacts, 64);
      error = ofpacts_parse_actions(argv[3], &ofpacts, &usable_protocols);
      if (error) {
          ovs_fatal(0, "%s", error);
      }
  
      po.buffer_id = UINT32_MAX;
      po.in_port = str_to_port_no(argv[1], argv[2]);
      po.ofpacts = ofpbuf_data(&ofpacts);
      po.ofpacts_len = ofpbuf_size(&ofpacts);
  
      protocol = open_vconn(argv[1], &vconn);
      for (i = 4; i < argc; i++) {
          struct ofpbuf *packet, *opo;
          const char *error_msg;
  
          error_msg = eth_from_hex(argv[i], &packet);
          if (error_msg) {
              ovs_fatal(0, "%s", error_msg);
          }
  
          po.packet = ofpbuf_data(packet);
          po.packet_len = ofpbuf_size(packet);
          opo = ofputil_encode_packet_out(&po, protocol);
          transact_noreply(vconn, opo);
          ofpbuf_delete(packet);
      }
      vconn_close(vconn);
      ofpbuf_uninit(&ofpacts);
  }
  
  static void
  ofctl_mod_port(int argc OVS_UNUSED, char *argv[])
  {
      struct ofp_config_flag {
          const char *name;             /* The flag's name. */
          enum ofputil_port_config bit; /* Bit to turn on or off. */
          bool on;                      /* Value to set the bit to. */
      };
      static const struct ofp_config_flag flags[] = {
          { "up",          OFPUTIL_PC_PORT_DOWN,    false },
          { "down",        OFPUTIL_PC_PORT_DOWN,    true  },
          { "stp",         OFPUTIL_PC_NO_STP,       false },
          { "receive",     OFPUTIL_PC_NO_RECV,      false },
          { "receive-stp", OFPUTIL_PC_NO_RECV_STP,  false },
          { "flood",       OFPUTIL_PC_NO_FLOOD,     false },
          { "forward",     OFPUTIL_PC_NO_FWD,       false },
          { "packet-in",   OFPUTIL_PC_NO_PACKET_IN, false },
      };
  
      const struct ofp_config_flag *flag;
      enum ofputil_protocol protocol;
      struct ofputil_port_mod pm;
      struct ofputil_phy_port pp;
      struct vconn *vconn;
      const char *command;
      bool not;
  
      fetch_ofputil_phy_port(argv[1], argv[2], &pp);
  
      pm.port_no = pp.port_no;
      memcpy(pm.hw_addr, pp.hw_addr, ETH_ADDR_LEN);
      pm.config = 0;
      pm.mask = 0;
      pm.advertise = 0;
  
      if (!strncasecmp(argv[3], "no-", 3)) {
          command = argv[3] + 3;
          not = true;
      } else if (!strncasecmp(argv[3], "no", 2)) {
          command = argv[3] + 2;
          not = true;
      } else {
          command = argv[3];
          not = false;
      }
      for (flag = flags; flag < &flags[ARRAY_SIZE(flags)]; flag++) {
          if (!strcasecmp(command, flag->name)) {
              pm.mask = flag->bit;
              pm.config = flag->on ^ not ? flag->bit : 0;
              goto found;
          }
      }
      ovs_fatal(0, "unknown mod-port command '%s'", argv[3]);
  
  found:
      protocol = open_vconn(argv[1], &vconn);
      transact_noreply(vconn, ofputil_encode_port_mod(&pm, protocol));
      vconn_close(vconn);
  }
  
  static void
  ofctl_mod_table(int argc OVS_UNUSED, char *argv[])
  {
      enum ofputil_protocol protocol, usable_protocols;
      struct ofputil_table_mod tm;
      struct vconn *vconn;
      char *error;
      int i;
  
      error = parse_ofp_table_mod(&tm, argv[2], argv[3], &usable_protocols);
      if (error) {
          ovs_fatal(0, "%s", error);
      }
  
      protocol = open_vconn(argv[1], &vconn);
      if (!(protocol & usable_protocols)) {
          for (i = 0; i < sizeof(enum ofputil_protocol) * CHAR_BIT; i++) {
              enum ofputil_protocol f = 1 << i;
              if (f != protocol
                  && f & usable_protocols
                  && try_set_protocol(vconn, f, &protocol)) {
                  protocol = f;
                  break;
              }
          }
      }
  
      if (!(protocol & usable_protocols)) {
          char *usable_s = ofputil_protocols_to_string(usable_protocols);
          ovs_fatal(0, "Switch does not support table mod message(%s)", usable_s);
      }
  
      transact_noreply(vconn, ofputil_encode_table_mod(&tm, protocol));
      vconn_close(vconn);
  }
  
  static void
  ofctl_get_frags(int argc OVS_UNUSED, char *argv[])
  {
      struct ofp_switch_config config;
      struct vconn *vconn;
  
      open_vconn(argv[1], &vconn);
      fetch_switch_config(vconn, &config);
      puts(ofputil_frag_handling_to_string(ntohs(config.flags)));
      vconn_close(vconn);
  }
  
  static void
  ofctl_set_frags(int argc OVS_UNUSED, char *argv[])
  {
      struct ofp_switch_config config;
      enum ofp_config_flags mode;
      struct vconn *vconn;
      ovs_be16 flags;
  
      if (!ofputil_frag_handling_from_string(argv[2], &mode)) {
          ovs_fatal(0, "%s: unknown fragment handling mode", argv[2]);
      }
  
      open_vconn(argv[1], &vconn);
      fetch_switch_config(vconn, &config);
      flags = htons(mode) | (config.flags & htons(~OFPC_FRAG_MASK));
      if (flags != config.flags) {
          /* Set the configuration. */
          config.flags = flags;
          set_switch_config(vconn, &config);
  
          /* Then retrieve the configuration to see if it really took.  OpenFlow
           * doesn't define error reporting for bad modes, so this is all we can
           * do. */
          fetch_switch_config(vconn, &config);
          if (flags != config.flags) {
              ovs_fatal(0, "%s: setting fragment handling mode failed (this "
                        "switch probably doesn't support mode \"%s\")",
                        argv[1], ofputil_frag_handling_to_string(mode));
          }
      }
      vconn_close(vconn);
  }
  
  static void
  ofctl_ofp_parse(int argc OVS_UNUSED, char *argv[])
  {
      const char *filename = argv[1];
      struct ofpbuf b;
      FILE *file;
  
      file = !strcmp(filename, "-") ? stdin : fopen(filename, "r");
      if (file == NULL) {
          ovs_fatal(errno, "%s: open", filename);
      }
  
      ofpbuf_init(&b, 65536);
      for (;;) {
          struct ofp_header *oh;
          size_t length, tail_len;
          void *tail;
          size_t n;
  
          ofpbuf_clear(&b);
          oh = ofpbuf_put_uninit(&b, sizeof *oh);
          n = fread(oh, 1, sizeof *oh, file);
          if (n == 0) {
              break;
          } else if (n < sizeof *oh) {
              ovs_fatal(0, "%s: unexpected end of file mid-message", filename);
          }
  
          length = ntohs(oh->length);
          if (length < sizeof *oh) {
              ovs_fatal(0, "%s: %"PRIuSIZE"-byte message is too short for OpenFlow",
                        filename, length);
          }
  
          tail_len = length - sizeof *oh;
          tail = ofpbuf_put_uninit(&b, tail_len);
          n = fread(tail, 1, tail_len, file);
          if (n < tail_len) {
              ovs_fatal(0, "%s: unexpected end of file mid-message", filename);
          }
  
          ofp_print(stdout, ofpbuf_data(&b), ofpbuf_size(&b), verbosity + 2);
      }
      ofpbuf_uninit(&b);
  
      if (file != stdin) {
          fclose(file);
      }
  }
  
  static bool
  is_openflow_port(ovs_be16 port_, char *ports[])
  {
      uint16_t port = ntohs(port_);
      if (ports[0]) {
          int i;
  
          for (i = 0; ports[i]; i++) {
              if (port == atoi(ports[i])) {
                  return true;
              }
          }
          return false;
      } else {
          return port == OFP_PORT || port == OFP_OLD_PORT;
      }
  }
  
  static void
  ofctl_ofp_parse_pcap(int argc OVS_UNUSED, char *argv[])
  {
      struct tcp_reader *reader;
      FILE *file;
      int error;
      bool first;
  
      file = ovs_pcap_open(argv[1], "rb");
      if (!file) {
          ovs_fatal(errno, "%s: open failed", argv[1]);
      }
  
      reader = tcp_reader_open();
      first = true;
      for (;;) {
          struct ofpbuf *packet;
          long long int when;
          struct flow flow;
          const struct pkt_metadata md = PKT_METADATA_INITIALIZER(ODPP_NONE);
  
          error = ovs_pcap_read(file, &packet, &when);
          if (error) {
              break;
          }
          flow_extract(packet, &md, &flow);
          if (flow.dl_type == htons(ETH_TYPE_IP)
              && flow.nw_proto == IPPROTO_TCP
              && (is_openflow_port(flow.tp_src, argv + 2) ||
                  is_openflow_port(flow.tp_dst, argv + 2))) {
              struct ofpbuf *payload = tcp_reader_run(reader, &flow, packet);
              if (payload) {
                  while (ofpbuf_size(payload) >= sizeof(struct ofp_header)) {
                      const struct ofp_header *oh;
                      void *data = ofpbuf_data(payload);
                      int length;
  
                      /* Align OpenFlow on 8-byte boundary for safe access. */
                      ofpbuf_shift(payload, -((intptr_t) data & 7));
  
                      oh = ofpbuf_data(payload);
                      length = ntohs(oh->length);
                      if (ofpbuf_size(payload) < length) {
                          break;
                      }
  
                      if (!first) {
                          putchar('\n');
                      }
                      first = false;
  
                      if (timestamp) {
                          char *s = xastrftime_msec("%H:%M:%S.### ", when, true);
                          fputs(s, stdout);
                          free(s);
                      }
  
                      printf(IP_FMT".%"PRIu16" > "IP_FMT".%"PRIu16":\n",
                             IP_ARGS(flow.nw_src), ntohs(flow.tp_src),
                             IP_ARGS(flow.nw_dst), ntohs(flow.tp_dst));
                      ofp_print(stdout, ofpbuf_data(payload), length, verbosity + 1);
                      ofpbuf_pull(payload, length);
                  }
              }
          }
          ofpbuf_delete(packet);
      }
      tcp_reader_close(reader);
  }
  
  static void
  ofctl_ping(int argc, char *argv[])
  {
      size_t max_payload = 65535 - sizeof(struct ofp_header);
      unsigned int payload;
      struct vconn *vconn;
      int i;
  
      payload = argc > 2 ? atoi(argv[2]) : 64;
      if (payload > max_payload) {
          ovs_fatal(0, "payload must be between 0 and %"PRIuSIZE" bytes", max_payload);
      }
  
      open_vconn(argv[1], &vconn);
      for (i = 0; i < 10; i++) {
          struct timeval start, end;
          struct ofpbuf *request, *reply;
          const struct ofp_header *rpy_hdr;
          enum ofptype type;
  
          request = ofpraw_alloc(OFPRAW_OFPT_ECHO_REQUEST,
                                 vconn_get_version(vconn), payload);
          random_bytes(ofpbuf_put_uninit(request, payload), payload);
  
          xgettimeofday(&start);
          run(vconn_transact(vconn, ofpbuf_clone(request), &reply), "transact");
          xgettimeofday(&end);
  
          rpy_hdr = ofpbuf_data(reply);
          if (ofptype_pull(&type, reply)
              || type != OFPTYPE_ECHO_REPLY
              || ofpbuf_size(reply) != payload
              || memcmp(ofpbuf_l3(request), ofpbuf_l3(reply), payload)) {
              printf("Reply does not match request.  Request:\n");
              ofp_print(stdout, request, ofpbuf_size(request), verbosity + 2);
              printf("Reply:\n");
              ofp_print(stdout, reply, ofpbuf_size(reply), verbosity + 2);
          }
          printf("%"PRIu32" bytes from %s: xid=%08"PRIx32" time=%.1f ms\n",
                 ofpbuf_size(reply), argv[1], ntohl(rpy_hdr->xid),
                     (1000*(double)(end.tv_sec - start.tv_sec))
                     + (.001*(end.tv_usec - start.tv_usec)));
          ofpbuf_delete(request);
          ofpbuf_delete(reply);
      }
      vconn_close(vconn);
  }
  
  static void
  ofctl_benchmark(int argc OVS_UNUSED, char *argv[])
  {
      size_t max_payload = 65535 - sizeof(struct ofp_header);
      struct timeval start, end;
      unsigned int payload_size, message_size;
      struct vconn *vconn;
      double duration;
      int count;
      int i;
  
      payload_size = atoi(argv[2]);
      if (payload_size > max_payload) {
          ovs_fatal(0, "payload must be between 0 and %"PRIuSIZE" bytes", max_payload);
      }
      message_size = sizeof(struct ofp_header) + payload_size;
  
      count = atoi(argv[3]);
  
      printf("Sending %d packets * %u bytes (with header) = %u bytes total\n",
             count, message_size, count * message_size);
  
      open_vconn(argv[1], &vconn);
      xgettimeofday(&start);
      for (i = 0; i < count; i++) {
          struct ofpbuf *request, *reply;
  
          request = ofpraw_alloc(OFPRAW_OFPT_ECHO_REQUEST,
                                 vconn_get_version(vconn), payload_size);
          ofpbuf_put_zeros(request, payload_size);
          run(vconn_transact(vconn, request, &reply), "transact");
          ofpbuf_delete(reply);
      }
      xgettimeofday(&end);
      vconn_close(vconn);
  
      duration = ((1000*(double)(end.tv_sec - start.tv_sec))
                  + (.001*(end.tv_usec - start.tv_usec)));
      printf("Finished in %.1f ms (%.0f packets/s) (%.0f bytes/s)\n",
             duration, count / (duration / 1000.0),
             count * message_size / (duration / 1000.0));
  }
  
  static void
  ofctl_group_mod__(const char *remote, struct ofputil_group_mod *gms,
                    size_t n_gms, enum ofputil_protocol usable_protocols)
  {
      enum ofputil_protocol protocol;
      struct ofputil_group_mod *gm;
      enum ofp_version version;
      struct ofpbuf *request;
  
      struct vconn *vconn;
      size_t i;
  
      protocol = open_vconn_for_flow_mod(remote, &vconn, usable_protocols);
      version = ofputil_protocol_to_ofp_version(protocol);
  
      for (i = 0; i < n_gms; i++) {
          gm = &gms[i];
          request = ofputil_encode_group_mod(version, gm);
          if (request) {
              transact_noreply(vconn, request);
          }
      }
  
      vconn_close(vconn);
  
  }
  
  
  static void
  ofctl_group_mod_file(int argc OVS_UNUSED, char *argv[], uint16_t command)
  {
      struct ofputil_group_mod *gms = NULL;
      enum ofputil_protocol usable_protocols;
      size_t n_gms = 0;
      char *error;
      int i;
  
      error = parse_ofp_group_mod_file(argv[2], command, &gms, &n_gms,
                                       &usable_protocols);
      if (error) {
          ovs_fatal(0, "%s", error);
      }
      ofctl_group_mod__(argv[1], gms, n_gms, usable_protocols);
      for (i = 0; i < n_gms; i++) {
          ofputil_bucket_list_destroy(&gms[i].buckets);
      }
      free(gms);
  }
  
  static void
  ofctl_group_mod(int argc, char *argv[], uint16_t command)
  {
      if (argc > 2 && !strcmp(argv[2], "-")) {
          ofctl_group_mod_file(argc, argv, command);
      } else {
          enum ofputil_protocol usable_protocols;
          struct ofputil_group_mod gm;
          char *error;
  
          error = parse_ofp_group_mod_str(&gm, command, argc > 2 ? argv[2] : "",
                                          &usable_protocols);
          if (error) {
              ovs_fatal(0, "%s", error);
          }
          ofctl_group_mod__(argv[1], &gm, 1, usable_protocols);
          ofputil_bucket_list_destroy(&gm.buckets);
      }
  }
  
  static void
  ofctl_add_group(int argc, char *argv[])
  {
      ofctl_group_mod(argc, argv, OFPGC11_ADD);
  }
  
  static void
  ofctl_add_groups(int argc, char *argv[])
  {
      ofctl_group_mod_file(argc, argv, OFPGC11_ADD);
  }
  
  static void
  ofctl_mod_group(int argc, char *argv[])
  {
      ofctl_group_mod(argc, argv, OFPGC11_MODIFY);
  }
  
  static void
  ofctl_del_groups(int argc, char *argv[])
  {
      ofctl_group_mod(argc, argv, OFPGC11_DELETE);
  }
  
  static void
  ofctl_insert_bucket(int argc, char *argv[])
  {
      ofctl_group_mod(argc, argv, OFPGC15_INSERT_BUCKET);
  }
  
  static void
  ofctl_remove_bucket(int argc, char *argv[])
  {
      ofctl_group_mod(argc, argv, OFPGC15_REMOVE_BUCKET);
  }
  
  static void
  ofctl_dump_group_stats(int argc, char *argv[])
  {
      enum ofputil_protocol usable_protocols;
      struct ofputil_group_mod gm;
      struct ofpbuf *request;
      struct vconn *vconn;
      uint32_t group_id;
      char *error;
  
      memset(&gm, 0, sizeof gm);
  
      error = parse_ofp_group_mod_str(&gm, OFPGC11_DELETE,
                                      argc > 2 ? argv[2] : "",
                                      &usable_protocols);
      if (error) {
          ovs_fatal(0, "%s", error);
      }
  
      group_id = gm.group_id;
  
      open_vconn(argv[1], &vconn);
      request = ofputil_encode_group_stats_request(vconn_get_version(vconn),
                                                   group_id);
      if (request) {
          dump_stats_transaction(vconn, request);
      }
  
      vconn_close(vconn);
  }
  
  static void
  ofctl_dump_group_desc(int argc OVS_UNUSED, char *argv[])
  {
      struct ofpbuf *request;
      struct vconn *vconn;
      uint32_t group_id;
  
      open_vconn(argv[1], &vconn);
  
      if (argc < 3 || !ofputil_group_from_string(argv[2], &group_id)) {
          group_id = OFPG11_ALL;
      }
  
      request = ofputil_encode_group_desc_request(vconn_get_version(vconn),
                                                  group_id);
      if (request) {
          dump_stats_transaction(vconn, request);
      }
  
      vconn_close(vconn);
  }
  
  static void
  ofctl_dump_group_features(int argc OVS_UNUSED, char *argv[])
  {
      struct ofpbuf *request;
      struct vconn *vconn;
  
      open_vconn(argv[1], &vconn);
      request = ofputil_encode_group_features_request(vconn_get_version(vconn));
      if (request) {
          dump_stats_transaction(vconn, request);
      }
  
      vconn_close(vconn);
  }
  
  static void
  ofctl_help(int argc OVS_UNUSED, char *argv[] OVS_UNUSED)
  {
      usage();
  }
  
  static void
  ofctl_list_commands(int argc OVS_UNUSED, char *argv[] OVS_UNUSED)
  {
      print_commands(get_all_commands());
  }
  
  /* replace-flows and diff-flows commands. */
  
  /* A flow table entry, possibly with two different versions. */
  struct fte {
      struct cls_rule rule;       /* Within a "struct classifier". */
      struct fte_version *versions[2];
  };
  
  /* One version of a Flow Table Entry. */
  struct fte_version {
      ovs_be64 cookie;
      uint16_t idle_timeout;
      uint16_t hard_timeout;
      uint16_t importance;
      uint16_t flags;
      struct ofpact *ofpacts;
      size_t ofpacts_len;
  };
  
  /* Frees 'version' and the data that it owns. */
  static void
  fte_version_free(struct fte_version *version)
  {
      if (version) {
          free(CONST_CAST(struct ofpact *, version->ofpacts));
          free(version);
      }
  }
  
  /* Returns true if 'a' and 'b' are the same, false if they differ.
   *
   * Ignores differences in 'flags' because there's no way to retrieve flags from
   * an OpenFlow switch.  We have to assume that they are the same. */
  static bool
  fte_version_equals(const struct fte_version *a, const struct fte_version *b)
  {
      return (a->cookie == b->cookie
              && a->idle_timeout == b->idle_timeout
              && a->hard_timeout == b->hard_timeout
              && a->importance == b->importance
              && ofpacts_equal(a->ofpacts, a->ofpacts_len,
                               b->ofpacts, b->ofpacts_len));
  }
  
  /* Clears 's', then if 's' has a version 'index', formats 'fte' and version
   * 'index' into 's', followed by a new-line. */
  static void
  fte_version_format(const struct fte *fte, int index, struct ds *s)
  {
      const struct fte_version *version = fte->versions[index];
  
      ds_clear(s);
      if (!version) {
          return;
      }
  
      cls_rule_format(&fte->rule, s);
      if (version->cookie != htonll(0)) {
          ds_put_format(s, " cookie=0x%"PRIx64, ntohll(version->cookie));
      }
      if (version->idle_timeout != OFP_FLOW_PERMANENT) {
          ds_put_format(s, " idle_timeout=%"PRIu16, version->idle_timeout);
      }
      if (version->hard_timeout != OFP_FLOW_PERMANENT) {
          ds_put_format(s, " hard_timeout=%"PRIu16, version->hard_timeout);
      }
      if (version->importance != 0) {
          ds_put_format(s, " importance=%"PRIu16, version->importance);
      }
  
      ds_put_cstr(s, " actions=");
      ofpacts_format(version->ofpacts, version->ofpacts_len, s);
  
      ds_put_char(s, '\n');
  }
  
  static struct fte *
  fte_from_cls_rule(const struct cls_rule *cls_rule)
  {
      return cls_rule ? CONTAINER_OF(cls_rule, struct fte, rule) : NULL;
  }
  
  /* Frees 'fte' and its versions. */
  static void
  fte_free(struct fte *fte)
  {
      if (fte) {
          fte_version_free(fte->versions[0]);
          fte_version_free(fte->versions[1]);
          cls_rule_destroy(&fte->rule);
          free(fte);
      }
  }
  
  /* Frees all of the FTEs within 'cls'. */
  static void
  fte_free_all(struct classifier *cls)
  {
      struct fte *fte;
  
      classifier_defer(cls);
      CLS_FOR_EACH (fte, rule, cls) {
          classifier_remove(cls, &fte->rule);
          ovsrcu_postpone(fte_free, fte);
      }
      classifier_destroy(cls);
  }
  
  /* Searches 'cls' for an FTE matching 'rule', inserting a new one if
   * necessary.  Sets 'version' as the version of that rule with the given
   * 'index', replacing any existing version, if any.
   *
   * Takes ownership of 'version'. */
  static void
  fte_insert(struct classifier *cls, const struct match *match,
             int priority, struct fte_version *version, int index)
  {
      struct fte *old, *fte;
  
      fte = xzalloc(sizeof *fte);
      cls_rule_init(&fte->rule, match, priority);
      fte->versions[index] = version;
  
      old = fte_from_cls_rule(classifier_replace(cls, &fte->rule));
      if (old) {
          fte->versions[!index] = old->versions[!index];
          old->versions[!index] = NULL;
  
          ovsrcu_postpone(fte_free, old);
      }
  }
  
  /* Reads the flows in 'filename' as flow table entries in 'cls' for the version
   * with the specified 'index'.  Returns the flow formats able to represent the
   * flows that were read. */
  static enum ofputil_protocol
  read_flows_from_file(const char *filename, struct classifier *cls, int index)
  {
      enum ofputil_protocol usable_protocols;
      int line_number;
      struct ds s;
      FILE *file;
  
      file = !strcmp(filename, "-") ? stdin : fopen(filename, "r");
      if (file == NULL) {
          ovs_fatal(errno, "%s: open", filename);
      }
  
      ds_init(&s);
      usable_protocols = OFPUTIL_P_ANY;
      line_number = 0;
      classifier_defer(cls);
      while (!ds_get_preprocessed_line(&s, file, &line_number)) {
          struct fte_version *version;
          struct ofputil_flow_mod fm;
          char *error;
          enum ofputil_protocol usable;
  
          error = parse_ofp_str(&fm, OFPFC_ADD, ds_cstr(&s), &usable);
          if (error) {
              ovs_fatal(0, "%s:%d: %s", filename, line_number, error);
          }
          usable_protocols &= usable;
  
          version = xmalloc(sizeof *version);
          version->cookie = fm.new_cookie;
          version->idle_timeout = fm.idle_timeout;
          version->hard_timeout = fm.hard_timeout;
          version->importance = fm.importance;
          version->flags = fm.flags & (OFPUTIL_FF_SEND_FLOW_REM
                                       | OFPUTIL_FF_EMERG);
          version->ofpacts = fm.ofpacts;
          version->ofpacts_len = fm.ofpacts_len;
  
          fte_insert(cls, &fm.match, fm.priority, version, index);
      }
      classifier_publish(cls);
      ds_destroy(&s);
  
      if (file != stdin) {
          fclose(file);
      }
  
      return usable_protocols;
  }
  
  static bool
  recv_flow_stats_reply(struct vconn *vconn, ovs_be32 send_xid,
                        struct ofpbuf **replyp,
                        struct ofputil_flow_stats *fs, struct ofpbuf *ofpacts)
  {
      struct ofpbuf *reply = *replyp;
  
      for (;;) {
          int retval;
          bool more;
  
          /* Get a flow stats reply message, if we don't already have one. */
          if (!reply) {
              enum ofptype type;
              enum ofperr error;
  
              do {
                  run(vconn_recv_block(vconn, &reply),
                      "OpenFlow packet receive failed");
              } while (((struct ofp_header *) ofpbuf_data(reply))->xid != send_xid);
  
              error = ofptype_decode(&type, ofpbuf_data(reply));
              if (error || type != OFPTYPE_FLOW_STATS_REPLY) {
                  ovs_fatal(0, "received bad reply: %s",
                            ofp_to_string(ofpbuf_data(reply), ofpbuf_size(reply),
                                          verbosity + 1));
              }
          }
  
          /* Pull an individual flow stats reply out of the message. */
          retval = ofputil_decode_flow_stats_reply(fs, reply, false, ofpacts);
          switch (retval) {
          case 0:
              *replyp = reply;
              return true;
  
          case EOF:
              more = ofpmp_more(reply->frame);
              ofpbuf_delete(reply);
              reply = NULL;
              if (!more) {
                  *replyp = NULL;
                  return false;
              }
              break;
  
          default:
              ovs_fatal(0, "parse error in reply (%s)",
                        ofperr_to_string(retval));
          }
      }
  }
  
  /* Reads the OpenFlow flow table from 'vconn', which has currently active flow
   * format 'protocol', and adds them as flow table entries in 'cls' for the
   * version with the specified 'index'. */
  static void
  read_flows_from_switch(struct vconn *vconn,
                         enum ofputil_protocol protocol,
                         struct classifier *cls, int index)
  {
      struct ofputil_flow_stats_request fsr;
      struct ofputil_flow_stats fs;
      struct ofpbuf *request;
      struct ofpbuf ofpacts;
      struct ofpbuf *reply;
      ovs_be32 send_xid;
  
      fsr.aggregate = false;
      match_init_catchall(&fsr.match);
      fsr.out_port = OFPP_ANY;
      fsr.table_id = 0xff;
      fsr.cookie = fsr.cookie_mask = htonll(0);
      request = ofputil_encode_flow_stats_request(&fsr, protocol);
      send_xid = ((struct ofp_header *) ofpbuf_data(request))->xid;
      send_openflow_buffer(vconn, request);
  
      reply = NULL;
      ofpbuf_init(&ofpacts, 0);
      classifier_defer(cls);
      while (recv_flow_stats_reply(vconn, send_xid, &reply, &fs, &ofpacts)) {
          struct fte_version *version;
  
          version = xmalloc(sizeof *version);
          version->cookie = fs.cookie;
          version->idle_timeout = fs.idle_timeout;
          version->hard_timeout = fs.hard_timeout;
          version->importance = fs.importance;
          version->flags = 0;
          version->ofpacts_len = fs.ofpacts_len;
          version->ofpacts = xmemdup(fs.ofpacts, fs.ofpacts_len);
  
          fte_insert(cls, &fs.match, fs.priority, version, index);
      }
      classifier_publish(cls);
      ofpbuf_uninit(&ofpacts);
  }
  
  static void
  fte_make_flow_mod(const struct fte *fte, int index, uint16_t command,
                    enum ofputil_protocol protocol, struct ovs_list *packets)
  {
      const struct fte_version *version = fte->versions[index];
      struct ofputil_flow_mod fm;
      struct ofpbuf *ofm;
  
      minimatch_expand(&fte->rule.match, &fm.match);
      fm.priority = fte->rule.priority;
      fm.cookie = htonll(0);
      fm.cookie_mask = htonll(0);
      fm.new_cookie = version->cookie;
      fm.modify_cookie = true;
      fm.table_id = 0xff;
      fm.command = command;
      fm.idle_timeout = version->idle_timeout;
      fm.hard_timeout = version->hard_timeout;
      fm.importance = version->importance;
      fm.buffer_id = UINT32_MAX;
      fm.out_port = OFPP_ANY;
      fm.flags = version->flags;
      if (command == OFPFC_ADD || command == OFPFC_MODIFY ||
          command == OFPFC_MODIFY_STRICT) {
          fm.ofpacts = version->ofpacts;
          fm.ofpacts_len = version->ofpacts_len;
      } else {
          fm.ofpacts = NULL;
          fm.ofpacts_len = 0;
      }
      fm.delete_reason = OFPRR_DELETE;
  
      ofm = ofputil_encode_flow_mod(&fm, protocol);
      list_push_back(packets, &ofm->list_node);
  }
  
  static void
  ofctl_replace_flows(int argc OVS_UNUSED, char *argv[])
  {
      enum { FILE_IDX = 0, SWITCH_IDX = 1 };
      enum ofputil_protocol usable_protocols, protocol;
      struct classifier cls;
      struct ovs_list requests;
      struct vconn *vconn;
      struct fte *fte;
  
      classifier_init(&cls, NULL);
      usable_protocols = read_flows_from_file(argv[2], &cls, FILE_IDX);
  
      protocol = open_vconn(argv[1], &vconn);
      protocol = set_protocol_for_flow_dump(vconn, protocol, usable_protocols);
  
      read_flows_from_switch(vconn, protocol, &cls, SWITCH_IDX);
  
      list_init(&requests);
  
      /* Delete flows that exist on the switch but not in the file. */
      CLS_FOR_EACH (fte, rule, &cls) {
          struct fte_version *file_ver = fte->versions[FILE_IDX];
          struct fte_version *sw_ver = fte->versions[SWITCH_IDX];
  
          if (sw_ver && !file_ver) {
              fte_make_flow_mod(fte, SWITCH_IDX, OFPFC_DELETE_STRICT,
                                protocol, &requests);
          }
      }
  
      /* Add flows that exist in the file but not on the switch.
       * Update flows that exist in both places but differ. */
      CLS_FOR_EACH (fte, rule, &cls) {
          struct fte_version *file_ver = fte->versions[FILE_IDX];
          struct fte_version *sw_ver = fte->versions[SWITCH_IDX];
  
          if (file_ver
              && (readd || !sw_ver || !fte_version_equals(sw_ver, file_ver))) {
              fte_make_flow_mod(fte, FILE_IDX, OFPFC_ADD, protocol, &requests);
          }
      }
      transact_multiple_noreply(vconn, &requests);
      vconn_close(vconn);
  
      fte_free_all(&cls);
  }
  
  static void
  read_flows_from_source(const char *source, struct classifier *cls, int index)
  {
      struct stat s;
  
      if (source[0] == '/' || source[0] == '.'
          || (!strchr(source, ':') && !stat(source, &s))) {
          read_flows_from_file(source, cls, index);
      } else {
          enum ofputil_protocol protocol;
          struct vconn *vconn;
  
          protocol = open_vconn(source, &vconn);
          protocol = set_protocol_for_flow_dump(vconn, protocol, OFPUTIL_P_ANY);
          read_flows_from_switch(vconn, protocol, cls, index);
          vconn_close(vconn);
      }
  }
  
  static void
  ofctl_diff_flows(int argc OVS_UNUSED, char *argv[])
  {
      bool differences = false;
      struct classifier cls;
      struct ds a_s, b_s;
      struct fte *fte;
  
      classifier_init(&cls, NULL);
      read_flows_from_source(argv[1], &cls, 0);
      read_flows_from_source(argv[2], &cls, 1);
  
      ds_init(&a_s);
      ds_init(&b_s);
  
      CLS_FOR_EACH (fte, rule, &cls) {
          struct fte_version *a = fte->versions[0];
          struct fte_version *b = fte->versions[1];
  
          if (!a || !b || !fte_version_equals(a, b)) {
              fte_version_format(fte, 0, &a_s);
              fte_version_format(fte, 1, &b_s);
              if (strcmp(ds_cstr(&a_s), ds_cstr(&b_s))) {
                  if (a_s.length) {
                      printf("-%s", ds_cstr(&a_s));
                  }
                  if (b_s.length) {
                      printf("+%s", ds_cstr(&b_s));
                  }
                  differences = true;
              }
          }
      }
  
      ds_destroy(&a_s);
      ds_destroy(&b_s);
  
      fte_free_all(&cls);
  
      if (differences) {
          exit(2);
      }
  }
  
  static void
  ofctl_meter_mod__(const char *bridge, const char *str, int command)
  {
      struct ofputil_meter_mod mm;
      struct vconn *vconn;
      enum ofputil_protocol protocol;
      enum ofputil_protocol usable_protocols;
      enum ofp_version version;
  
      if (str) {
          char *error;
          error = parse_ofp_meter_mod_str(&mm, str, command, &usable_protocols);
          if (error) {
              ovs_fatal(0, "%s", error);
          }
      } else {
          usable_protocols = OFPUTIL_P_OF13_UP;
          mm.command = command;
          mm.meter.meter_id = OFPM13_ALL;
      }
  
      protocol = open_vconn_for_flow_mod(bridge, &vconn, usable_protocols);
      version = ofputil_protocol_to_ofp_version(protocol);
      transact_noreply(vconn, ofputil_encode_meter_mod(version, &mm));
      vconn_close(vconn);
  }
  
  static void
  ofctl_meter_request__(const char *bridge, const char *str,
                        enum ofputil_meter_request_type type)
  {
      struct ofputil_meter_mod mm;
      struct vconn *vconn;
      enum ofputil_protocol usable_protocols;
      enum ofputil_protocol protocol;
      enum ofp_version version;
  
      if (str) {
          char *error;
          error = parse_ofp_meter_mod_str(&mm, str, -1, &usable_protocols);
          if (error) {
              ovs_fatal(0, "%s", error);
          }
      } else {
          usable_protocols = OFPUTIL_P_OF13_UP;
          mm.meter.meter_id = OFPM13_ALL;
      }
  
      protocol = open_vconn_for_flow_mod(bridge, &vconn, usable_protocols);
      version = ofputil_protocol_to_ofp_version(protocol);
      transact_noreply(vconn, ofputil_encode_meter_request(version,
                                                           type,
                                                           mm.meter.meter_id));
      vconn_close(vconn);
  }
  
  
  static void
  ofctl_add_meter(int argc OVS_UNUSED, char *argv[])
  {
      ofctl_meter_mod__(argv[1], argv[2], OFPMC13_ADD);
  }
  
  static void
  ofctl_mod_meter(int argc OVS_UNUSED, char *argv[])
  {
      ofctl_meter_mod__(argv[1], argv[2], OFPMC13_MODIFY);
  }
  
  static void
  ofctl_del_meters(int argc, char *argv[])
  {
      ofctl_meter_mod__(argv[1], argc > 2 ? argv[2] : NULL, OFPMC13_DELETE);
  }
  
  static void
  ofctl_dump_meters(int argc, char *argv[])
  {
      ofctl_meter_request__(argv[1], argc > 2 ? argv[2] : NULL,
                            OFPUTIL_METER_CONFIG);
  }
  
  static void
  ofctl_meter_stats(int argc, char *argv[])
  {
      ofctl_meter_request__(argv[1], argc > 2 ? argv[2] : NULL,
                            OFPUTIL_METER_STATS);
  }
  
  static void
  ofctl_meter_features(int argc OVS_UNUSED, char *argv[])
  {
      ofctl_meter_request__(argv[1], NULL, OFPUTIL_METER_FEATURES);
  }
  
  
  /* Undocumented commands for unit testing. */
  
  static void
  ofctl_parse_flows__(struct ofputil_flow_mod *fms, size_t n_fms,
                      enum ofputil_protocol usable_protocols)
  {
      enum ofputil_protocol protocol = 0;
      char *usable_s;
      size_t i;
  
      usable_s = ofputil_protocols_to_string(usable_protocols);
      printf("usable protocols: %s\n", usable_s);
      free(usable_s);
  
      if (!(usable_protocols & allowed_protocols)) {
          ovs_fatal(0, "no usable protocol");
      }
      for (i = 0; i < sizeof(enum ofputil_protocol) * CHAR_BIT; i++) {
          protocol = 1 << i;
          if (protocol & usable_protocols & allowed_protocols) {
              break;
          }
      }
      ovs_assert(is_pow2(protocol));
  
      printf("chosen protocol: %s\n", ofputil_protocol_to_string(protocol));
  
      for (i = 0; i < n_fms; i++) {
          struct ofputil_flow_mod *fm = &fms[i];
          struct ofpbuf *msg;
  
          msg = ofputil_encode_flow_mod(fm, protocol);
          ofp_print(stdout, ofpbuf_data(msg), ofpbuf_size(msg), verbosity);
          ofpbuf_delete(msg);
  
          free(CONST_CAST(struct ofpact *, fm->ofpacts));
      }
  }
  
  /* "parse-flow FLOW": parses the argument as a flow (like add-flow) and prints
   * it back to stdout.  */
  static void
  ofctl_parse_flow(int argc OVS_UNUSED, char *argv[])
  {
      enum ofputil_protocol usable_protocols;
      struct ofputil_flow_mod fm;
      char *error;
  
      error = parse_ofp_flow_mod_str(&fm, argv[1], OFPFC_ADD, &usable_protocols);
      if (error) {
          ovs_fatal(0, "%s", error);
      }
      ofctl_parse_flows__(&fm, 1, usable_protocols);
  }
  
  /* "parse-flows FILENAME": reads the named file as a sequence of flows (like
   * add-flows) and prints each of the flows back to stdout.  */
  static void
  ofctl_parse_flows(int argc OVS_UNUSED, char *argv[])
  {
      enum ofputil_protocol usable_protocols;
      struct ofputil_flow_mod *fms = NULL;
      size_t n_fms = 0;
      char *error;
  
      error = parse_ofp_flow_mod_file(argv[1], OFPFC_ADD, &fms, &n_fms,
                                      &usable_protocols);
      if (error) {
          ovs_fatal(0, "%s", error);
      }
      ofctl_parse_flows__(fms, n_fms, usable_protocols);
      free(fms);
  }
  
  static void
  ofctl_parse_nxm__(bool oxm, enum ofp_version version)
  {
      struct ds in;
  
      ds_init(&in);
      while (!ds_get_test_line(&in, stdin)) {
          struct ofpbuf nx_match;
          struct match match;
          ovs_be64 cookie, cookie_mask;
          enum ofperr error;
          int match_len;
  
          /* Convert string to nx_match. */
          ofpbuf_init(&nx_match, 0);
          if (oxm) {
              match_len = oxm_match_from_string(ds_cstr(&in), &nx_match);
          } else {
              match_len = nx_match_from_string(ds_cstr(&in), &nx_match);
          }
  
          /* Convert nx_match to match. */
          if (strict) {
              if (oxm) {
                  error = oxm_pull_match(&nx_match, &match);
              } else {
                  error = nx_pull_match(&nx_match, match_len, &match,
                                        &cookie, &cookie_mask);
              }
          } else {
              if (oxm) {
                  error = oxm_pull_match_loose(&nx_match, &match);
              } else {
                  error = nx_pull_match_loose(&nx_match, match_len, &match,
                                              &cookie, &cookie_mask);
              }
          }
  
  
          if (!error) {
              char *out;
  
              /* Convert match back to nx_match. */
              ofpbuf_uninit(&nx_match);
              ofpbuf_init(&nx_match, 0);
              if (oxm) {
                  match_len = oxm_put_match(&nx_match, &match, version);
                  out = oxm_match_to_string(&nx_match, match_len);
              } else {
                  match_len = nx_put_match(&nx_match, &match,
                                           cookie, cookie_mask);
                  out = nx_match_to_string(ofpbuf_data(&nx_match), match_len);
              }
  
              puts(out);
              free(out);
  
              if (verbosity > 0) {
                  ovs_hex_dump(stdout, ofpbuf_data(&nx_match),
                               ofpbuf_size(&nx_match), 0, false);
              }
          } else {
              printf("nx_pull_match() returned error %s\n",
                     ofperr_get_name(error));
          }
  
          ofpbuf_uninit(&nx_match);
      }
      ds_destroy(&in);
  }
  
  /* "parse-nxm": reads a series of NXM nx_match specifications as strings from
   * stdin, does some internal fussing with them, and then prints them back as
   * strings on stdout. */
  static void
  ofctl_parse_nxm(int argc OVS_UNUSED, char *argv[] OVS_UNUSED)
  {
      ofctl_parse_nxm__(false, 0);
  }
  
  /* "parse-oxm VERSION": reads a series of OXM nx_match specifications as
   * strings from stdin, does some internal fussing with them, and then prints
   * them back as strings on stdout.  VERSION must specify an OpenFlow version,
   * e.g. "OpenFlow12". */
  static void
  ofctl_parse_oxm(int argc OVS_UNUSED, char *argv[])
  {
      enum ofp_version version = ofputil_version_from_string(argv[1]);
      if (version < OFP12_VERSION) {
          ovs_fatal(0, "%s: not a valid version for OXM", argv[1]);
      }
  
      ofctl_parse_nxm__(true, version);
  }
  
  static void
  print_differences(const char *prefix,
                    const void *a_, size_t a_len,
                    const void *b_, size_t b_len)
  {
      const uint8_t *a = a_;
      const uint8_t *b = b_;
      size_t i;
  
      for (i = 0; i < MIN(a_len, b_len); i++) {
          if (a[i] != b[i]) {
              printf("%s%2"PRIuSIZE": %02"PRIx8" -> %02"PRIx8"\n",
                     prefix, i, a[i], b[i]);
          }
      }
      for (i = a_len; i < b_len; i++) {
          printf("%s%2"PRIuSIZE": (none) -> %02"PRIx8"\n", prefix, i, b[i]);
      }
      for (i = b_len; i < a_len; i++) {
          printf("%s%2"PRIuSIZE": %02"PRIx8" -> (none)\n", prefix, i, a[i]);
      }
  }
  
  static void
  ofctl_parse_actions__(const char *version_s, bool instructions)
  {
      enum ofp_version version;
      struct ds in;
  
      version = ofputil_version_from_string(version_s);
      if (!version) {
          ovs_fatal(0, "%s: not a valid OpenFlow version", version_s);
      }
  
      ds_init(&in);
      while (!ds_get_preprocessed_line(&in, stdin, NULL)) {
          struct ofpbuf of_out;
          struct ofpbuf of_in;
          struct ofpbuf ofpacts;
          const char *table_id;
          char *actions;
          enum ofperr error;
          size_t size;
          struct ds s;
  
          /* Parse table_id separated with the follow-up actions by ",", if
           * any. */
          actions = ds_cstr(&in);
          table_id = NULL;
          if (strstr(actions, ",")) {
              table_id = strsep(&actions, ",");
          }
  
          /* Parse hex bytes. */
          ofpbuf_init(&of_in, 0);
          if (ofpbuf_put_hex(&of_in, actions, NULL)[0] != '\0') {
              ovs_fatal(0, "Trailing garbage in hex data");
          }
  
          /* Convert to ofpacts. */
          ofpbuf_init(&ofpacts, 0);
          size = ofpbuf_size(&of_in);
          error = (instructions
                   ? ofpacts_pull_openflow_instructions
                   : ofpacts_pull_openflow_actions)(
                       &of_in, ofpbuf_size(&of_in), version, &ofpacts);
          if (!error && instructions) {
              /* Verify actions, enforce consistency. */
              enum ofputil_protocol protocol;
              struct flow flow;
  
              memset(&flow, 0, sizeof flow);
              protocol = ofputil_protocols_from_ofp_version(version);
              error = ofpacts_check_consistency(ofpbuf_data(&ofpacts),
                                                ofpbuf_size(&ofpacts),
                                                &flow, OFPP_MAX,
                                                table_id ? atoi(table_id) : 0,
                                                255, protocol);
          }
          if (error) {
              printf("bad %s %s: %s\n\n",
                     version_s, instructions ? "instructions" : "actions",
                     ofperr_get_name(error));
              ofpbuf_uninit(&ofpacts);
              ofpbuf_uninit(&of_in);
              continue;
          }
          ofpbuf_push_uninit(&of_in, size);
  
          /* Print cls_rule. */
          ds_init(&s);
          ds_put_cstr(&s, "actions=");
          ofpacts_format(ofpbuf_data(&ofpacts), ofpbuf_size(&ofpacts), &s);
          puts(ds_cstr(&s));
          ds_destroy(&s);
  
          /* Convert back to ofp10 actions and print differences from input. */
          ofpbuf_init(&of_out, 0);
          if (instructions) {
             ofpacts_put_openflow_instructions( ofpbuf_data(&ofpacts),
                                                ofpbuf_size(&ofpacts),
                                                &of_out, version);
          } else {
             ofpacts_put_openflow_actions( ofpbuf_data(&ofpacts),
                                           ofpbuf_size(&ofpacts),
                                           &of_out, version);
          }
  
          print_differences("", ofpbuf_data(&of_in), ofpbuf_size(&of_in),
                            ofpbuf_data(&of_out), ofpbuf_size(&of_out));
          putchar('\n');
  
          ofpbuf_uninit(&ofpacts);
          ofpbuf_uninit(&of_in);
          ofpbuf_uninit(&of_out);
      }
      ds_destroy(&in);
  }
  
  /* "parse-actions VERSION": reads a series of action specifications for the
   * given OpenFlow VERSION as hex bytes from stdin, converts them to ofpacts,
   * prints them as strings on stdout, and then converts them back to hex bytes
   * and prints any differences from the input. */
  static void
  ofctl_parse_actions(int argc OVS_UNUSED, char *argv[] OVS_UNUSED)
  {
      ofctl_parse_actions__(argv[1], false);
  }
  
  /* "parse-actions VERSION": reads a series of instruction specifications for
   * the given OpenFlow VERSION as hex bytes from stdin, converts them to
   * ofpacts, prints them as strings on stdout, and then converts them back to
   * hex bytes and prints any differences from the input. */
  static void
  ofctl_parse_instructions(int argc OVS_UNUSED, char *argv[] OVS_UNUSED)
  {
      ofctl_parse_actions__(argv[1], true);
  }
  
  /* "parse-ofp10-match": reads a series of ofp10_match specifications as hex
   * bytes from stdin, converts them to cls_rules, prints them as strings on
   * stdout, and then converts them back to hex bytes and prints any differences
   * from the input.
   *
   * The input hex bytes may contain "x"s to represent "don't-cares", bytes whose
   * values are ignored in the input and will be set to zero when OVS converts
   * them back to hex bytes.  ovs-ofctl actually sets "x"s to random bits when
   * it does the conversion to hex, to ensure that in fact they are ignored. */
  static void
  ofctl_parse_ofp10_match(int argc OVS_UNUSED, char *argv[] OVS_UNUSED)
  {
      struct ds expout;
      struct ds in;
  
      ds_init(&in);
      ds_init(&expout);
      while (!ds_get_preprocessed_line(&in, stdin, NULL)) {
          struct ofpbuf match_in, match_expout;
          struct ofp10_match match_out;
          struct ofp10_match match_normal;
          struct match match;
          char *p;
  
          /* Parse hex bytes to use for expected output. */
          ds_clear(&expout);
          ds_put_cstr(&expout, ds_cstr(&in));
          for (p = ds_cstr(&expout); *p; p++) {
              if (*p == 'x') {
                  *p = '0';
              }
          }
          ofpbuf_init(&match_expout, 0);
          if (ofpbuf_put_hex(&match_expout, ds_cstr(&expout), NULL)[0] != '\0') {
              ovs_fatal(0, "Trailing garbage in hex data");
          }
          if (ofpbuf_size(&match_expout) != sizeof(struct ofp10_match)) {
              ovs_fatal(0, "Input is %"PRIu32" bytes, expected %"PRIuSIZE,
                        ofpbuf_size(&match_expout), sizeof(struct ofp10_match));
          }
  
          /* Parse hex bytes for input. */
          for (p = ds_cstr(&in); *p; p++) {
              if (*p == 'x') {
                  *p = "0123456789abcdef"[random_uint32() & 0xf];
              }
          }
          ofpbuf_init(&match_in, 0);
          if (ofpbuf_put_hex(&match_in, ds_cstr(&in), NULL)[0] != '\0') {
              ovs_fatal(0, "Trailing garbage in hex data");
          }
          if (ofpbuf_size(&match_in) != sizeof(struct ofp10_match)) {
              ovs_fatal(0, "Input is %"PRIu32" bytes, expected %"PRIuSIZE,
                        ofpbuf_size(&match_in), sizeof(struct ofp10_match));
          }
  
          /* Convert to cls_rule and print. */
          ofputil_match_from_ofp10_match(ofpbuf_data(&match_in), &match);
          match_print(&match);
  
          /* Convert back to ofp10_match and print differences from input. */
          ofputil_match_to_ofp10_match(&match, &match_out);
          print_differences("", ofpbuf_data(&match_expout), ofpbuf_size(&match_expout),
                            &match_out, sizeof match_out);
  
          /* Normalize, then convert and compare again. */
          ofputil_normalize_match(&match);
          ofputil_match_to_ofp10_match(&match, &match_normal);
          print_differences("normal: ", &match_out, sizeof match_out,
                            &match_normal, sizeof match_normal);
          putchar('\n');
  
          ofpbuf_uninit(&match_in);
          ofpbuf_uninit(&match_expout);
      }
      ds_destroy(&in);
      ds_destroy(&expout);
  }
  
  /* "parse-ofp11-match": reads a series of ofp11_match specifications as hex
   * bytes from stdin, converts them to "struct match"es, prints them as strings
   * on stdout, and then converts them back to hex bytes and prints any
   * differences from the input. */
  static void
  ofctl_parse_ofp11_match(int argc OVS_UNUSED, char *argv[] OVS_UNUSED)
  {
      struct ds in;
  
      ds_init(&in);
      while (!ds_get_preprocessed_line(&in, stdin, NULL)) {
          struct ofpbuf match_in;
          struct ofp11_match match_out;
          struct match match;
          enum ofperr error;
  
          /* Parse hex bytes. */
          ofpbuf_init(&match_in, 0);
          if (ofpbuf_put_hex(&match_in, ds_cstr(&in), NULL)[0] != '\0') {
              ovs_fatal(0, "Trailing garbage in hex data");
          }
          if (ofpbuf_size(&match_in) != sizeof(struct ofp11_match)) {
              ovs_fatal(0, "Input is %"PRIu32" bytes, expected %"PRIuSIZE,
                        ofpbuf_size(&match_in), sizeof(struct ofp11_match));
          }
  
          /* Convert to match. */
          error = ofputil_match_from_ofp11_match(ofpbuf_data(&match_in), &match);
          if (error) {
              printf("bad ofp11_match: %s\n\n", ofperr_get_name(error));
              ofpbuf_uninit(&match_in);
              continue;
          }
  
          /* Print match. */
          match_print(&match);
  
          /* Convert back to ofp11_match and print differences from input. */
          ofputil_match_to_ofp11_match(&match, &match_out);
  
          print_differences("", ofpbuf_data(&match_in), ofpbuf_size(&match_in),
                            &match_out, sizeof match_out);
          putchar('\n');
  
          ofpbuf_uninit(&match_in);
      }
      ds_destroy(&in);
  }
  
  /* "parse-pcap PCAP": read packets from PCAP and print their flows. */
  static void
  ofctl_parse_pcap(int argc OVS_UNUSED, char *argv[])
  {
      FILE *pcap;
  
      pcap = ovs_pcap_open(argv[1], "rb");
      if (!pcap) {
          ovs_fatal(errno, "%s: open failed", argv[1]);
      }
  
      for (;;) {
          struct ofpbuf *packet;
          struct flow flow;
          const struct pkt_metadata md = PKT_METADATA_INITIALIZER(ODPP_NONE);
          int error;
  
          error = ovs_pcap_read(pcap, &packet, NULL);
          if (error == EOF) {
              break;
          } else if (error) {
              ovs_fatal(error, "%s: read failed", argv[1]);
          }
  
          flow_extract(packet, &md, &flow);
          flow_print(stdout, &flow);
          putchar('\n');
          ofpbuf_delete(packet);
      }
  }
  
  /* "check-vlan VLAN_TCI VLAN_TCI_MASK": converts the specified vlan_tci and
   * mask values to and from various formats and prints the results. */
  static void
  ofctl_check_vlan(int argc OVS_UNUSED, char *argv[])
  {
      struct match match;
  
      char *string_s;
      struct ofputil_flow_mod fm;
  
      struct ofpbuf nxm;
      struct match nxm_match;
      int nxm_match_len;
      char *nxm_s;
  
      struct ofp10_match of10_raw;
      struct match of10_match;
  
      struct ofp11_match of11_raw;
      struct match of11_match;
  
      enum ofperr error;
      char *error_s;
  
      enum ofputil_protocol usable_protocols; /* Unused for now. */
  
      match_init_catchall(&match);
      match.flow.vlan_tci = htons(strtoul(argv[1], NULL, 16));
      match.wc.masks.vlan_tci = htons(strtoul(argv[2], NULL, 16));
  
      /* Convert to and from string. */
      string_s = match_to_string(&match, OFP_DEFAULT_PRIORITY);
      printf("%s -> ", string_s);
      fflush(stdout);
      error_s = parse_ofp_str(&fm, -1, string_s, &usable_protocols);
      if (error_s) {
          ovs_fatal(0, "%s", error_s);
      }
      printf("%04"PRIx16"/%04"PRIx16"\n",
             ntohs(fm.match.flow.vlan_tci),
             ntohs(fm.match.wc.masks.vlan_tci));
      free(string_s);
  
      /* Convert to and from NXM. */
      ofpbuf_init(&nxm, 0);
      nxm_match_len = nx_put_match(&nxm, &match, htonll(0), htonll(0));
      nxm_s = nx_match_to_string(ofpbuf_data(&nxm), nxm_match_len);
      error = nx_pull_match(&nxm, nxm_match_len, &nxm_match, NULL, NULL);
      printf("NXM: %s -> ", nxm_s);
      if (error) {
          printf("%s\n", ofperr_to_string(error));
      } else {
          printf("%04"PRIx16"/%04"PRIx16"\n",
                 ntohs(nxm_match.flow.vlan_tci),
                 ntohs(nxm_match.wc.masks.vlan_tci));
      }
      free(nxm_s);
      ofpbuf_uninit(&nxm);
  
      /* Convert to and from OXM. */
      ofpbuf_init(&nxm, 0);
      nxm_match_len = oxm_put_match(&nxm, &match, OFP12_VERSION);
      nxm_s = oxm_match_to_string(&nxm, nxm_match_len);
      error = oxm_pull_match(&nxm, &nxm_match);
      printf("OXM: %s -> ", nxm_s);
      if (error) {
          printf("%s\n", ofperr_to_string(error));
      } else {
          uint16_t vid = ntohs(nxm_match.flow.vlan_tci) &
              (VLAN_VID_MASK | VLAN_CFI);
          uint16_t mask = ntohs(nxm_match.wc.masks.vlan_tci) &
              (VLAN_VID_MASK | VLAN_CFI);
  
          printf("%04"PRIx16"/%04"PRIx16",", vid, mask);
          if (vid && vlan_tci_to_pcp(nxm_match.wc.masks.vlan_tci)) {
              printf("%02"PRIx8"\n", vlan_tci_to_pcp(nxm_match.flow.vlan_tci));
          } else {
              printf("--\n");
          }
      }
      free(nxm_s);
      ofpbuf_uninit(&nxm);
  
      /* Convert to and from OpenFlow 1.0. */
      ofputil_match_to_ofp10_match(&match, &of10_raw);
      ofputil_match_from_ofp10_match(&of10_raw, &of10_match);
      printf("OF1.0: %04"PRIx16"/%d,%02"PRIx8"/%d -> %04"PRIx16"/%04"PRIx16"\n",
             ntohs(of10_raw.dl_vlan),
             (of10_raw.wildcards & htonl(OFPFW10_DL_VLAN)) != 0,
             of10_raw.dl_vlan_pcp,
             (of10_raw.wildcards & htonl(OFPFW10_DL_VLAN_PCP)) != 0,
             ntohs(of10_match.flow.vlan_tci),
             ntohs(of10_match.wc.masks.vlan_tci));
  
      /* Convert to and from OpenFlow 1.1. */
      ofputil_match_to_ofp11_match(&match, &of11_raw);
      ofputil_match_from_ofp11_match(&of11_raw, &of11_match);
      printf("OF1.1: %04"PRIx16"/%d,%02"PRIx8"/%d -> %04"PRIx16"/%04"PRIx16"\n",
             ntohs(of11_raw.dl_vlan),
             (of11_raw.wildcards & htonl(OFPFW11_DL_VLAN)) != 0,
             of11_raw.dl_vlan_pcp,
             (of11_raw.wildcards & htonl(OFPFW11_DL_VLAN_PCP)) != 0,
             ntohs(of11_match.flow.vlan_tci),
             ntohs(of11_match.wc.masks.vlan_tci));
  }
  
  /* "print-error ENUM": Prints the type and code of ENUM for every OpenFlow
   * version. */
  static void
  ofctl_print_error(int argc OVS_UNUSED, char *argv[])
  {
      enum ofperr error;
      int version;
  
      error = ofperr_from_name(argv[1]);
      if (!error) {
          ovs_fatal(0, "unknown error \"%s\"", argv[1]);
      }
  
      for (version = 0; version <= UINT8_MAX; version++) {
          const char *name = ofperr_domain_get_name(version);
          if (name) {
              int vendor = ofperr_get_vendor(error, version);
              int type = ofperr_get_type(error, version);
              int code = ofperr_get_code(error, version);
  
              if (vendor != -1 || type != -1 || code != -1) {
                  printf("%s: vendor %#x, type %d, code %d\n",
                         name, vendor, type, code);
              }
          }
      }
  }
  
  /* "encode-error-reply ENUM REQUEST": Encodes an error reply to REQUEST for the
   * error named ENUM and prints the error reply in hex. */
  static void
  ofctl_encode_error_reply(int argc OVS_UNUSED, char *argv[])
  {
      const struct ofp_header *oh;
      struct ofpbuf request, *reply;
      enum ofperr error;
  
      error = ofperr_from_name(argv[1]);
      if (!error) {
          ovs_fatal(0, "unknown error \"%s\"", argv[1]);
      }
  
      ofpbuf_init(&request, 0);
      if (ofpbuf_put_hex(&request, argv[2], NULL)[0] != '\0') {
          ovs_fatal(0, "Trailing garbage in hex data");
      }
      if (ofpbuf_size(&request) < sizeof(struct ofp_header)) {
          ovs_fatal(0, "Request too short");
      }
  
      oh = ofpbuf_data(&request);
      if (ofpbuf_size(&request) != ntohs(oh->length)) {
          ovs_fatal(0, "Request size inconsistent");
      }
  
      reply = ofperr_encode_reply(error, ofpbuf_data(&request));
      ofpbuf_uninit(&request);
  
      ovs_hex_dump(stdout, ofpbuf_data(reply), ofpbuf_size(reply), 0, false);
      ofpbuf_delete(reply);
  }
  
  /* "ofp-print HEXSTRING [VERBOSITY]": Converts the hex digits in HEXSTRING into
   * binary data, interpreting them as an OpenFlow message, and prints the
   * OpenFlow message on stdout, at VERBOSITY (level 2 by default).
   *
   * Alternative usage: "ofp-print [VERBOSITY] - < HEXSTRING_FILE", where
   * HEXSTRING_FILE contains the HEXSTRING. */
  static void
  ofctl_ofp_print(int argc, char *argv[])
  {
      struct ofpbuf packet;
      char *buffer;
      int verbosity = 2;
      struct ds line;
  
      ds_init(&line);
  
      if (!strcmp(argv[argc-1], "-")) {
          if (ds_get_line(&line, stdin)) {
             VLOG_FATAL("Failed to read stdin");
          }
  
          buffer = line.string;
          verbosity = argc > 2 ? atoi(argv[1]) : verbosity;
      } else if (argc > 2) {
          buffer = argv[1];
          verbosity = atoi(argv[2]);
      } else {
          buffer = argv[1];
      }
  
      ofpbuf_init(&packet, strlen(buffer) / 2);
      if (ofpbuf_put_hex(&packet, buffer, NULL)[0] != '\0') {
          ovs_fatal(0, "trailing garbage following hex bytes");
      }
      ofp_print(stdout, ofpbuf_data(&packet), ofpbuf_size(&packet), verbosity);
      ofpbuf_uninit(&packet);
      ds_destroy(&line);
  }
  
  /* "encode-hello BITMAP...": Encodes each BITMAP as an OpenFlow hello message
   * and dumps each message in hex.  */
  static void
  ofctl_encode_hello(int argc OVS_UNUSED, char *argv[])
  {
      uint32_t bitmap = strtol(argv[1], NULL, 0);
      struct ofpbuf *hello;
  
      hello = ofputil_encode_hello(bitmap);
      ovs_hex_dump(stdout, ofpbuf_data(hello), ofpbuf_size(hello), 0, false);
      ofp_print(stdout, ofpbuf_data(hello), ofpbuf_size(hello), verbosity);
      ofpbuf_delete(hello);
  }
  
  static const struct command all_commands[] = {
      { "show", "switch",
        1, 1, ofctl_show },
      { "monitor", "switch [misslen] [invalid_ttl] [watch:[...]]",
        1, 3, ofctl_monitor },
      { "snoop", "switch",
        1, 1, ofctl_snoop },
      { "dump-desc", "switch",
        1, 1, ofctl_dump_desc },
      { "dump-tables", "switch",
        1, 1, ofctl_dump_tables },
      { "dump-table-features", "switch",
        1, 1, ofctl_dump_table_features },
      { "dump-flows", "switch",
        1, 2, ofctl_dump_flows },
      { "dump-aggregate", "switch",
        1, 2, ofctl_dump_aggregate },
      { "queue-stats", "switch [port [queue]]",
        1, 3, ofctl_queue_stats },
      { "queue-get-config", "switch port",
        2, 2, ofctl_queue_get_config },
      { "add-flow", "switch flow",
        2, 2, ofctl_add_flow },
      { "add-flows", "switch file",
        2, 2, ofctl_add_flows },
      { "mod-flows", "switch flow",
        2, 2, ofctl_mod_flows },
      { "del-flows", "switch [flow]",
        1, 2, ofctl_del_flows },
      { "replace-flows", "switch file",
        2, 2, ofctl_replace_flows },
      { "diff-flows", "source1 source2",
        2, 2, ofctl_diff_flows },
      { "add-meter", "switch meter",
        2, 2, ofctl_add_meter },
      { "mod-meter", "switch meter",
        2, 2, ofctl_mod_meter },
      { "del-meter", "switch meter",
        2, 2, ofctl_del_meters },
      { "del-meters", "switch",
        1, 1, ofctl_del_meters },
      { "dump-meter", "switch meter",
        2, 2, ofctl_dump_meters },
      { "dump-meters", "switch",
        1, 1, ofctl_dump_meters },
      { "meter-stats", "switch [meter]",
        1, 2, ofctl_meter_stats },
      { "meter-features", "switch",
        1, 1, ofctl_meter_features },
      { "packet-out", "switch in_port actions packet...",
        4, INT_MAX, ofctl_packet_out },
      { "dump-ports", "switch [port]",
        1, 2, ofctl_dump_ports },
      { "dump-ports-desc", "switch [port]",
        1, 2, ofctl_dump_ports_desc },
      { "mod-port", "switch iface act",
        3, 3, ofctl_mod_port },
      { "mod-table", "switch mod",
        3, 3, ofctl_mod_table },
      { "get-frags", "switch",
        1, 1, ofctl_get_frags },
      { "set-frags", "switch frag_mode",
        2, 2, ofctl_set_frags },
      { "probe", "target",
        1, 1, ofctl_probe },
      { "ping", "target [n]",
        1, 2, ofctl_ping },
      { "benchmark", "target n count",
        3, 3, ofctl_benchmark },
  
      { "ofp-parse", "file",
        1, 1, ofctl_ofp_parse },
      { "ofp-parse-pcap", "pcap",
        1, INT_MAX, ofctl_ofp_parse_pcap },
  
      { "add-group", "switch group",
        1, 2, ofctl_add_group },
      { "add-groups", "switch file",
        1, 2, ofctl_add_groups },
      { "mod-group", "switch group",
        1, 2, ofctl_mod_group },
      { "del-groups", "switch [group]",
        1, 2, ofctl_del_groups },
      { "insert-buckets", "switch [group]",
        1, 2, ofctl_insert_bucket },
      { "remove-buckets", "switch [group]",
        1, 2, ofctl_remove_bucket },
      { "dump-groups", "switch [group]",
        1, 2, ofctl_dump_group_desc },
      { "dump-group-stats", "switch [group]",
        1, 2, ofctl_dump_group_stats },
      { "dump-group-features", "switch",
        1, 1, ofctl_dump_group_features },
      { "help", NULL, 0, INT_MAX, ofctl_help },
      { "list-commands", NULL, 0, INT_MAX, ofctl_list_commands },
  
      /* Undocumented commands for testing. */
      { "parse-flow", NULL, 1, 1, ofctl_parse_flow },
      { "parse-flows", NULL, 1, 1, ofctl_parse_flows },
      { "parse-nx-match", NULL, 0, 0, ofctl_parse_nxm },
      { "parse-nxm", NULL, 0, 0, ofctl_parse_nxm },
      { "parse-oxm", NULL, 1, 1, ofctl_parse_oxm },
      { "parse-actions", NULL, 1, 1, ofctl_parse_actions },
      { "parse-instructions", NULL, 1, 1, ofctl_parse_instructions },
      { "parse-ofp10-match", NULL, 0, 0, ofctl_parse_ofp10_match },
      { "parse-ofp11-match", NULL, 0, 0, ofctl_parse_ofp11_match },
      { "parse-pcap", NULL, 1, 1, ofctl_parse_pcap },
      { "check-vlan", NULL, 2, 2, ofctl_check_vlan },
      { "print-error", NULL, 1, 1, ofctl_print_error },
      { "encode-error-reply", NULL, 2, 2, ofctl_encode_error_reply },
      { "ofp-print", NULL, 1, 2, ofctl_ofp_print },
      { "encode-hello", NULL, 1, 1, ofctl_encode_hello },
  
      { NULL, NULL, 0, 0, NULL },
  };
  
  static const struct command *get_all_commands(void)
  {
      return all_commands;
  }
  