bridge/link.c

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2
   3 #include <stdio.h>
   4 #include <stdlib.h>
   5 #include <unistd.h>
   6 #include <time.h>
   7 #include <sys/socket.h>
   8 #include <sys/time.h>
   9 #include <netinet/in.h>
  10 #include <linux/if.h>
  11 #include <linux/if_bridge.h>
  12 #include <string.h>
  13 #include <stdbool.h>
  14
  15 #include "json_print.h"
  16 #include "libnetlink.h"
  17 #include "utils.h"
  18 #include "br_common.h"
  19
  20 static unsigned int filter_index;
  21
  22 static const char *port_states[] = {
  23         [BR_STATE_DISABLED] = "disabled",
  24         [BR_STATE_LISTENING] = "listening",
  25         [BR_STATE_LEARNING] = "learning",
  26         [BR_STATE_FORWARDING] = "forwarding",
  27         [BR_STATE_BLOCKING] = "blocking",
  28 };
  29
  30 static const char *hw_mode[] = {
  31         "VEB", "VEPA"
  32 };
  33
  34 static void print_link_flags(FILE *fp, unsigned int flags, unsigned int mdown)
  35 {
  36         open_json_array(PRINT_ANY, is_json_context() ? "flags" : "<");
  37         if (flags & IFF_UP && !(flags & IFF_RUNNING))
  38                 print_string(PRINT_ANY, NULL,
  39                              flags ? "%s," : "%s", "NO-CARRIER");
  40         flags &= ~IFF_RUNNING;
  41
  42 #define _PF(f) if (flags&IFF_##f) {                                     \
  43                 flags &= ~IFF_##f ;                                     \
  44                 print_string(PRINT_ANY, NULL, flags ? "%s," : "%s", #f); }
  45         _PF(LOOPBACK);
  46         _PF(BROADCAST);
  47         _PF(POINTOPOINT);
  48         _PF(MULTICAST);
  49         _PF(NOARP);
  50         _PF(ALLMULTI);
  51         _PF(PROMISC);
  52         _PF(MASTER);
  53         _PF(SLAVE);
  54         _PF(DEBUG);
  55         _PF(DYNAMIC);
  56         _PF(AUTOMEDIA);
  57         _PF(PORTSEL);
  58         _PF(NOTRAILERS);
  59         _PF(UP);
  60         _PF(LOWER_UP);
  61         _PF(DORMANT);
  62         _PF(ECHO);
  63 #undef _PF
  64         if (flags)
  65                 print_hex(PRINT_ANY, NULL, "%x", flags);
  66         if (mdown)
  67                 print_string(PRINT_ANY, NULL, ",%s", "M-DOWN");
  68         close_json_array(PRINT_ANY, "> ");
  69 }
  70
  71 static void print_portstate(__u8 state)
  72 {
  73         if (state <= BR_STATE_BLOCKING)
  74                 print_string(PRINT_ANY, "state",
  75                              "state %s ", port_states[state]);
  76         else
  77                 print_uint(PRINT_ANY, "state",
  78                              "state (%d) ", state);
  79 }
  80
  81 static void print_onoff(FILE *fp, const char *flag, __u8 val)
  82 {
  83         if (is_json_context())
  84                 print_bool(PRINT_JSON, flag, NULL, val);
  85         else
  86                 fprintf(fp, "%s %s ", flag, val ? "on" : "off");
  87 }
  88
  89 static void print_hwmode(__u16 mode)
  90 {
  91         if (mode >= ARRAY_SIZE(hw_mode))
  92                 print_0xhex(PRINT_ANY, "hwmode",
  93                             "hwmode %#llx ", mode);
  94         else
  95                 print_string(PRINT_ANY, "hwmode",
  96                              "hwmode %s ", hw_mode[mode]);
  97 }
  98
  99 static void print_protinfo(FILE *fp, struct rtattr *attr)
 100 {
 101         if (attr->rta_type & NLA_F_NESTED) {
 102                 struct rtattr *prtb[IFLA_BRPORT_MAX + 1];
 103
 104                 parse_rtattr_nested(prtb, IFLA_BRPORT_MAX, attr);
 105
 106                 if (prtb[IFLA_BRPORT_STATE])
 107                         print_portstate(rta_getattr_u8(prtb[IFLA_BRPORT_STATE]));
 108
 109                 if (prtb[IFLA_BRPORT_PRIORITY])
 110                         print_uint(PRINT_ANY, "priority",
 111                                    "priority %u ",
 112                                    rta_getattr_u16(prtb[IFLA_BRPORT_PRIORITY]));
 113
 114                 if (prtb[IFLA_BRPORT_COST])
 115                         print_uint(PRINT_ANY, "cost",
 116                                    "cost %u ",
 117                                    rta_getattr_u32(prtb[IFLA_BRPORT_COST]));
 118
 119                 if (!show_details)
 120                         return;
 121
 122                 if (!is_json_context())
 123                         fprintf(fp, "%s    ", _SL_);
 124
 125                 if (prtb[IFLA_BRPORT_MODE])
 126                         print_onoff(fp, "hairpin",
 127                                     rta_getattr_u8(prtb[IFLA_BRPORT_MODE]));
 128                 if (prtb[IFLA_BRPORT_GUARD])
 129                         print_onoff(fp, "guard",
 130                                     rta_getattr_u8(prtb[IFLA_BRPORT_GUARD]));
 131                 if (prtb[IFLA_BRPORT_PROTECT])
 132                         print_onoff(fp, "root_block",
 133                                     rta_getattr_u8(prtb[IFLA_BRPORT_PROTECT]));
 134                 if (prtb[IFLA_BRPORT_FAST_LEAVE])
 135                         print_onoff(fp, "fastleave",
 136                                     rta_getattr_u8(prtb[IFLA_BRPORT_FAST_LEAVE]));
 137                 if (prtb[IFLA_BRPORT_LEARNING])
 138                         print_onoff(fp, "learning",
 139                                     rta_getattr_u8(prtb[IFLA_BRPORT_LEARNING]));
 140                 if (prtb[IFLA_BRPORT_LEARNING_SYNC])
 141                         print_onoff(fp, "learning_sync",
 142                                     rta_getattr_u8(prtb[IFLA_BRPORT_LEARNING_SYNC]));
 143                 if (prtb[IFLA_BRPORT_UNICAST_FLOOD])
 144                         print_onoff(fp, "flood",
 145                                     rta_getattr_u8(prtb[IFLA_BRPORT_UNICAST_FLOOD]));
 146                 if (prtb[IFLA_BRPORT_MCAST_FLOOD])
 147                         print_onoff(fp, "mcast_flood",
 148                                     rta_getattr_u8(prtb[IFLA_BRPORT_MCAST_FLOOD]));
 149                 if (prtb[IFLA_BRPORT_NEIGH_SUPPRESS])
 150                         print_onoff(fp, "neigh_suppress",
 151                                     rta_getattr_u8(prtb[IFLA_BRPORT_NEIGH_SUPPRESS]));
 152                 if (prtb[IFLA_BRPORT_VLAN_TUNNEL])
 153                         print_onoff(fp, "vlan_tunnel",
 154                                     rta_getattr_u8(prtb[IFLA_BRPORT_VLAN_TUNNEL]));
 155
 156                 if (prtb[IFLA_BRPORT_BACKUP_PORT]) {
 157                         int ifidx;
 158
 159                         ifidx = rta_getattr_u32(prtb[IFLA_BRPORT_BACKUP_PORT]);
 160                         print_string(PRINT_ANY,
 161                                      "backup_port", "backup_port %s ",
 162                                      ll_index_to_name(ifidx));
 163                 }
 164
 165                 if (prtb[IFLA_BRPORT_ISOLATED])
 166                         print_onoff(fp, "isolated",
 167                                     rta_getattr_u8(prtb[IFLA_BRPORT_ISOLATED]));
 168         } else
 169                 print_portstate(rta_getattr_u8(attr));
 170 }
 171
 172
 173 /*
 174  * This is reported by HW devices that have some bridging
 175  * capabilities.
 176  */
 177 static void print_af_spec(struct rtattr *attr, int ifindex)
 178 {
 179         struct rtattr *aftb[IFLA_BRIDGE_MAX+1];
 180
 181         parse_rtattr_nested(aftb, IFLA_BRIDGE_MAX, attr);
 182
 183         if (aftb[IFLA_BRIDGE_MODE])
 184                 print_hwmode(rta_getattr_u16(aftb[IFLA_BRIDGE_MODE]));
 185
 186         if (!show_details)
 187                 return;
 188
 189         if (aftb[IFLA_BRIDGE_VLAN_INFO])
 190                 print_vlan_info(aftb[IFLA_BRIDGE_VLAN_INFO], ifindex);
 191 }
 192
 193 int print_linkinfo(struct nlmsghdr *n, void *arg)
 194 {
 195         FILE *fp = arg;
 196         struct ifinfomsg *ifi = NLMSG_DATA(n);
 197         struct rtattr *tb[IFLA_MAX+1];
 198         unsigned int m_flag = 0;
 199         int len = n->nlmsg_len;
 200         const char *name;
 201
 202         len -= NLMSG_LENGTH(sizeof(*ifi));
 203         if (len < 0) {
 204                 fprintf(stderr, "Message too short!\n");
 205                 return -1;
 206         }
 207
 208         if (!(ifi->ifi_family == AF_BRIDGE || ifi->ifi_family == AF_UNSPEC))
 209                 return 0;
 210
 211         if (filter_index && filter_index != ifi->ifi_index)
 212                 return 0;
 213
 214         parse_rtattr_flags(tb, IFLA_MAX, IFLA_RTA(ifi), len, NLA_F_NESTED);
 215
 216         name = get_ifname_rta(ifi->ifi_index, tb[IFLA_IFNAME]);
 217         if (!name)
 218                 return -1;
 219
 220         open_json_object(NULL);
 221         if (n->nlmsg_type == RTM_DELLINK)
 222                 print_bool(PRINT_ANY, "deleted", "Deleted ", true);
 223
 224         print_int(PRINT_ANY, "ifindex", "%d: ", ifi->ifi_index);
 225         m_flag = print_name_and_link("%s: ", name, tb);
 226         print_link_flags(fp, ifi->ifi_flags, m_flag);
 227
 228         if (tb[IFLA_MTU])
 229                 print_int(PRINT_ANY,
 230                           "mtu", "mtu %u ",
 231                           rta_getattr_u32(tb[IFLA_MTU]));
 232
 233         if (tb[IFLA_MASTER]) {
 234                 int master = rta_getattr_u32(tb[IFLA_MASTER]);
 235
 236                 print_string(PRINT_ANY, "master", "master %s ",
 237                              ll_index_to_name(master));
 238         }
 239
 240         if (tb[IFLA_PROTINFO])
 241                 print_protinfo(fp, tb[IFLA_PROTINFO]);
 242
 243         if (tb[IFLA_AF_SPEC])
 244                 print_af_spec(tb[IFLA_AF_SPEC], ifi->ifi_index);
 245
 246         print_string(PRINT_FP, NULL, "%s", "\n");
 247         close_json_object();
 248         fflush(fp);
 249         return 0;
 250 }
 251
 252 static void usage(void)
 253 {
 254         fprintf(stderr, "Usage: bridge link set dev DEV [ cost COST ] [ priority PRIO ] [ state STATE ]\n");
 255         fprintf(stderr, "                               [ guard {on | off} ]\n");
 256         fprintf(stderr, "                               [ hairpin {on | off} ]\n");
 257         fprintf(stderr, "                               [ fastleave {on | off} ]\n");
 258         fprintf(stderr, "                               [ root_block {on | off} ]\n");
 259         fprintf(stderr, "                               [ learning {on | off} ]\n");
 260         fprintf(stderr, "                               [ learning_sync {on | off} ]\n");
 261         fprintf(stderr, "                               [ flood {on | off} ]\n");
 262         fprintf(stderr, "                               [ mcast_flood {on | off} ]\n");
 263         fprintf(stderr, "                               [ neigh_suppress {on | off} ]\n");
 264         fprintf(stderr, "                               [ vlan_tunnel {on | off} ]\n");
 265         fprintf(stderr, "                               [ isolated {on | off} ]\n");
 266         fprintf(stderr, "                               [ hwmode {vepa | veb} ]\n");
 267         fprintf(stderr, "                               [ backup_port DEVICE ] [ nobackup_port ]\n");
 268         fprintf(stderr, "                               [ self ] [ master ]\n");
 269         fprintf(stderr, "       bridge link show [dev DEV]\n");
 270         exit(-1);
 271 }
 272
 273 static bool on_off(char *arg, __s8 *attr, char *val)
 274 {
 275         if (strcmp(val, "on") == 0)
 276                 *attr = 1;
 277         else if (strcmp(val, "off") == 0)
 278                 *attr = 0;
 279         else {
 280                 fprintf(stderr,
 281                         "Error: argument of \"%s\" must be \"on\" or \"off\"\n",
 282                         arg);
 283                 return false;
 284         }
 285
 286         return true;
 287 }
 288
 289 static int brlink_modify(int argc, char **argv)
 290 {
 291         struct {
 292                 struct nlmsghdr  n;
 293                 struct ifinfomsg ifm;
 294                 char             buf[512];
 295         } req = {
 296                 .n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
 297                 .n.nlmsg_flags = NLM_F_REQUEST,
 298                 .n.nlmsg_type = RTM_SETLINK,
 299                 .ifm.ifi_family = PF_BRIDGE,
 300         };
 301         char *d = NULL;
 302         int backup_port_idx = -1;
 303         __s8 neigh_suppress = -1;
 304         __s8 learning = -1;
 305         __s8 learning_sync = -1;
 306         __s8 flood = -1;
 307         __s8 vlan_tunnel = -1;
 308         __s8 mcast_flood = -1;
 309         __s8 isolated = -1;
 310         __s8 hairpin = -1;
 311         __s8 bpdu_guard = -1;
 312         __s8 fast_leave = -1;
 313         __s8 root_block = -1;
 314         __u32 cost = 0;
 315         __s16 priority = -1;
 316         __s8 state = -1;
 317         __s16 mode = -1;
 318         __u16 flags = 0;
 319         struct rtattr *nest;
 320
 321         while (argc > 0) {
 322                 if (strcmp(*argv, "dev") == 0) {
 323                         NEXT_ARG();
 324                         d = *argv;
 325                 } else if (strcmp(*argv, "guard") == 0) {
 326                         NEXT_ARG();
 327                         if (!on_off("guard", &bpdu_guard, *argv))
 328                                 return -1;
 329                 } else if (strcmp(*argv, "hairpin") == 0) {
 330                         NEXT_ARG();
 331                         if (!on_off("hairpin", &hairpin, *argv))
 332                                 return -1;
 333                 } else if (strcmp(*argv, "fastleave") == 0) {
 334                         NEXT_ARG();
 335                         if (!on_off("fastleave", &fast_leave, *argv))
 336                                 return -1;
 337                 } else if (strcmp(*argv, "root_block") == 0) {
 338                         NEXT_ARG();
 339                         if (!on_off("root_block", &root_block, *argv))
 340                                 return -1;
 341                 } else if (strcmp(*argv, "learning") == 0) {
 342                         NEXT_ARG();
 343                         if (!on_off("learning", &learning, *argv))
 344                                 return -1;
 345                 } else if (strcmp(*argv, "learning_sync") == 0) {
 346                         NEXT_ARG();
 347                         if (!on_off("learning_sync", &learning_sync, *argv))
 348                                 return -1;
 349                 } else if (strcmp(*argv, "flood") == 0) {
 350                         NEXT_ARG();
 351                         if (!on_off("flood", &flood, *argv))
 352                                 return -1;
 353                 } else if (strcmp(*argv, "mcast_flood") == 0) {
 354                         NEXT_ARG();
 355                         if (!on_off("mcast_flood", &mcast_flood, *argv))
 356                                 return -1;
 357                 } else if (strcmp(*argv, "cost") == 0) {
 358                         NEXT_ARG();
 359                         cost = atoi(*argv);
 360                 } else if (strcmp(*argv, "priority") == 0) {
 361                         NEXT_ARG();
 362                         priority = atoi(*argv);
 363                 } else if (strcmp(*argv, "state") == 0) {
 364                         NEXT_ARG();
 365                         char *endptr;
 366                         size_t nstates = ARRAY_SIZE(port_states);
 367
 368                         state = strtol(*argv, &endptr, 10);
 369                         if (!(**argv != '\0' && *endptr == '\0')) {
 370                                 for (state = 0; state < nstates; state++)
 371                                         if (strcmp(port_states[state], *argv) == 0)
 372                                                 break;
 373                                 if (state == nstates) {
 374                                         fprintf(stderr,
 375                                                 "Error: invalid STP port state\n");
 376                                         return -1;
 377                                 }
 378                         }
 379                 } else if (strcmp(*argv, "hwmode") == 0) {
 380                         NEXT_ARG();
 381                         flags = BRIDGE_FLAGS_SELF;
 382                         if (strcmp(*argv, "vepa") == 0)
 383                                 mode = BRIDGE_MODE_VEPA;
 384                         else if (strcmp(*argv, "veb") == 0)
 385                                 mode = BRIDGE_MODE_VEB;
 386                         else {
 387                                 fprintf(stderr,
 388                                         "Mode argument must be \"vepa\" or \"veb\".\n");
 389                                 return -1;
 390                         }
 391                 } else if (strcmp(*argv, "self") == 0) {
 392                         flags |= BRIDGE_FLAGS_SELF;
 393                 } else if (strcmp(*argv, "master") == 0) {
 394                         flags |= BRIDGE_FLAGS_MASTER;
 395                 } else if (strcmp(*argv, "neigh_suppress") == 0) {
 396                         NEXT_ARG();
 397                         if (!on_off("neigh_suppress", &neigh_suppress,
 398                                     *argv))
 399                                 return -1;
 400                 } else if (strcmp(*argv, "vlan_tunnel") == 0) {
 401                         NEXT_ARG();
 402                         if (!on_off("vlan_tunnel", &vlan_tunnel,
 403                                     *argv))
 404                                 return -1;
 405                 } else if (strcmp(*argv, "isolated") == 0) {
 406                         NEXT_ARG();
 407                         if (!on_off("isolated", &isolated, *argv))
 408                                 return -1;
 409                 } else if (strcmp(*argv, "backup_port") == 0) {
 410                         NEXT_ARG();
 411                         backup_port_idx = ll_name_to_index(*argv);
 412                         if (!backup_port_idx) {
 413                                 fprintf(stderr, "Error: device %s does not exist\n",
 414                                         *argv);
 415                                 return -1;
 416                         }
 417                 } else if (strcmp(*argv, "nobackup_port") == 0) {
 418                         backup_port_idx = 0;
 419                 } else {
 420                         usage();
 421                 }
 422                 argc--; argv++;
 423         }
 424         if (d == NULL) {
 425                 fprintf(stderr, "Device is a required argument.\n");
 426                 return -1;
 427         }
 428
 429
 430         req.ifm.ifi_index = ll_name_to_index(d);
 431         if (req.ifm.ifi_index == 0) {
 432                 fprintf(stderr, "Cannot find bridge device \"%s\"\n", d);
 433                 return -1;
 434         }
 435
 436         /* Nested PROTINFO attribute.  Contains: port flags, cost, priority and
 437          * state.
 438          */
 439         nest = addattr_nest(&req.n, sizeof(req),
 440                             IFLA_PROTINFO | NLA_F_NESTED);
 441         /* Flags first */
 442         if (bpdu_guard >= 0)
 443                 addattr8(&req.n, sizeof(req), IFLA_BRPORT_GUARD, bpdu_guard);
 444         if (hairpin >= 0)
 445                 addattr8(&req.n, sizeof(req), IFLA_BRPORT_MODE, hairpin);
 446         if (fast_leave >= 0)
 447                 addattr8(&req.n, sizeof(req), IFLA_BRPORT_FAST_LEAVE,
 448                          fast_leave);
 449         if (root_block >= 0)
 450                 addattr8(&req.n, sizeof(req), IFLA_BRPORT_PROTECT, root_block);
 451         if (flood >= 0)
 452                 addattr8(&req.n, sizeof(req), IFLA_BRPORT_UNICAST_FLOOD, flood);
 453         if (mcast_flood >= 0)
 454                 addattr8(&req.n, sizeof(req), IFLA_BRPORT_MCAST_FLOOD,
 455                          mcast_flood);
 456         if (learning >= 0)
 457                 addattr8(&req.n, sizeof(req), IFLA_BRPORT_LEARNING, learning);
 458         if (learning_sync >= 0)
 459                 addattr8(&req.n, sizeof(req), IFLA_BRPORT_LEARNING_SYNC,
 460                          learning_sync);
 461
 462         if (cost > 0)
 463                 addattr32(&req.n, sizeof(req), IFLA_BRPORT_COST, cost);
 464
 465         if (priority >= 0)
 466                 addattr16(&req.n, sizeof(req), IFLA_BRPORT_PRIORITY, priority);
 467
 468         if (state >= 0)
 469                 addattr8(&req.n, sizeof(req), IFLA_BRPORT_STATE, state);
 470
 471         if (neigh_suppress != -1)
 472                 addattr8(&req.n, sizeof(req), IFLA_BRPORT_NEIGH_SUPPRESS,
 473                          neigh_suppress);
 474         if (vlan_tunnel != -1)
 475                 addattr8(&req.n, sizeof(req), IFLA_BRPORT_VLAN_TUNNEL,
 476                          vlan_tunnel);
 477         if (isolated != -1)
 478                 addattr8(&req.n, sizeof(req), IFLA_BRPORT_ISOLATED, isolated);
 479
 480         if (backup_port_idx != -1)
 481                 addattr32(&req.n, sizeof(req), IFLA_BRPORT_BACKUP_PORT,
 482                           backup_port_idx);
 483
 484         addattr_nest_end(&req.n, nest);
 485
 486         /* IFLA_AF_SPEC nested attribute. Contains IFLA_BRIDGE_FLAGS that
 487          * designates master or self operation and IFLA_BRIDGE_MODE
 488          * for hw 'vepa' or 'veb' operation modes. The hwmodes are
 489          * only valid in 'self' mode on some devices so far.
 490          */
 491         if (mode >= 0 || flags > 0) {
 492                 nest = addattr_nest(&req.n, sizeof(req), IFLA_AF_SPEC);
 493
 494                 if (flags > 0)
 495                         addattr16(&req.n, sizeof(req), IFLA_BRIDGE_FLAGS, flags);
 496
 497                 if (mode >= 0)
 498                         addattr16(&req.n, sizeof(req), IFLA_BRIDGE_MODE, mode);
 499
 500                 addattr_nest_end(&req.n, nest);
 501         }
 502
 503         if (rtnl_talk(&rth, &req.n, NULL) < 0)
 504                 return -1;
 505
 506         return 0;
 507 }
 508
 509 static int brlink_show(int argc, char **argv)
 510 {
 511         char *filter_dev = NULL;
 512
 513         while (argc > 0) {
 514                 if (strcmp(*argv, "dev") == 0) {
 515                         NEXT_ARG();
 516                         if (filter_dev)
 517                                 duparg("dev", *argv);
 518                         filter_dev = *argv;
 519                 }
 520                 argc--; argv++;
 521         }
 522
 523         if (filter_dev) {
 524                 filter_index = ll_name_to_index(filter_dev);
 525                 if (!filter_index)
 526                         return nodev(filter_dev);
 527         }
 528
 529         if (show_details) {
 530                 if (rtnl_linkdump_req_filter(&rth, PF_BRIDGE,
 531                                              (compress_vlans ?
 532                                               RTEXT_FILTER_BRVLAN_COMPRESSED :
 533                                               RTEXT_FILTER_BRVLAN)) < 0) {
 534                         perror("Cannon send dump request");
 535                         exit(1);
 536                 }
 537         } else {
 538                 if (rtnl_linkdump_req(&rth, PF_BRIDGE) < 0) {
 539                         perror("Cannon send dump request");
 540                         exit(1);
 541                 }
 542         }
 543
 544         new_json_obj(json);
 545         if (rtnl_dump_filter(&rth, print_linkinfo, stdout) < 0) {
 546                 fprintf(stderr, "Dump terminated\n");
 547                 exit(1);
 548         }
 549
 550         delete_json_obj();
 551         fflush(stdout);
 552         return 0;
 553 }
 554
 555 int do_link(int argc, char **argv)
 556 {
 557         ll_init_map(&rth);
 558         if (argc > 0) {
 559                 if (matches(*argv, "set") == 0 ||
 560                     matches(*argv, "change") == 0)
 561                         return brlink_modify(argc-1, argv+1);
 562                 if (matches(*argv, "show") == 0 ||
 563                     matches(*argv, "lst") == 0 ||
 564                     matches(*argv, "list") == 0)
 565                         return brlink_show(argc-1, argv+1);
 566                 if (matches(*argv, "help") == 0)
 567                         usage();
 568         } else
 569                 return brlink_show(0, NULL);
 570
 571         fprintf(stderr, "Command \"%s\" is unknown, try \"bridge link help\".\n", *argv);
 572         exit(-1);
 573 }