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_MCAST_TO_UCAST])
 150                         print_onoff(fp, "mcast_to_unicast",
 151                                     rta_getattr_u8(prtb[IFLA_BRPORT_MCAST_TO_UCAST]));
 152                 if (prtb[IFLA_BRPORT_NEIGH_SUPPRESS])
 153                         print_onoff(fp, "neigh_suppress",
 154                                     rta_getattr_u8(prtb[IFLA_BRPORT_NEIGH_SUPPRESS]));
 155                 if (prtb[IFLA_BRPORT_VLAN_TUNNEL])
 156                         print_onoff(fp, "vlan_tunnel",
 157                                     rta_getattr_u8(prtb[IFLA_BRPORT_VLAN_TUNNEL]));
 158
 159                 if (prtb[IFLA_BRPORT_BACKUP_PORT]) {
 160                         int ifidx;
 161
 162                         ifidx = rta_getattr_u32(prtb[IFLA_BRPORT_BACKUP_PORT]);
 163                         print_string(PRINT_ANY,
 164                                      "backup_port", "backup_port %s ",
 165                                      ll_index_to_name(ifidx));
 166                 }
 167
 168                 if (prtb[IFLA_BRPORT_ISOLATED])
 169                         print_onoff(fp, "isolated",
 170                                     rta_getattr_u8(prtb[IFLA_BRPORT_ISOLATED]));
 171         } else
 172                 print_portstate(rta_getattr_u8(attr));
 173 }
 174
 175
 176 /*
 177  * This is reported by HW devices that have some bridging
 178  * capabilities.
 179  */
 180 static void print_af_spec(struct rtattr *attr, int ifindex)
 181 {
 182         struct rtattr *aftb[IFLA_BRIDGE_MAX+1];
 183
 184         parse_rtattr_nested(aftb, IFLA_BRIDGE_MAX, attr);
 185
 186         if (aftb[IFLA_BRIDGE_MODE])
 187                 print_hwmode(rta_getattr_u16(aftb[IFLA_BRIDGE_MODE]));
 188
 189         if (!show_details)
 190                 return;
 191
 192         if (aftb[IFLA_BRIDGE_VLAN_INFO])
 193                 print_vlan_info(aftb[IFLA_BRIDGE_VLAN_INFO], ifindex);
 194 }
 195
 196 int print_linkinfo(struct nlmsghdr *n, void *arg)
 197 {
 198         FILE *fp = arg;
 199         struct ifinfomsg *ifi = NLMSG_DATA(n);
 200         struct rtattr *tb[IFLA_MAX+1];
 201         unsigned int m_flag = 0;
 202         int len = n->nlmsg_len;
 203         const char *name;
 204
 205         len -= NLMSG_LENGTH(sizeof(*ifi));
 206         if (len < 0) {
 207                 fprintf(stderr, "Message too short!\n");
 208                 return -1;
 209         }
 210
 211         if (!(ifi->ifi_family == AF_BRIDGE || ifi->ifi_family == AF_UNSPEC))
 212                 return 0;
 213
 214         if (filter_index && filter_index != ifi->ifi_index)
 215                 return 0;
 216
 217         parse_rtattr_flags(tb, IFLA_MAX, IFLA_RTA(ifi), len, NLA_F_NESTED);
 218
 219         name = get_ifname_rta(ifi->ifi_index, tb[IFLA_IFNAME]);
 220         if (!name)
 221                 return -1;
 222
 223         open_json_object(NULL);
 224         if (n->nlmsg_type == RTM_DELLINK)
 225                 print_bool(PRINT_ANY, "deleted", "Deleted ", true);
 226
 227         print_int(PRINT_ANY, "ifindex", "%d: ", ifi->ifi_index);
 228         m_flag = print_name_and_link("%s: ", name, tb);
 229         print_link_flags(fp, ifi->ifi_flags, m_flag);
 230
 231         if (tb[IFLA_MTU])
 232                 print_int(PRINT_ANY,
 233                           "mtu", "mtu %u ",
 234                           rta_getattr_u32(tb[IFLA_MTU]));
 235
 236         if (tb[IFLA_MASTER]) {
 237                 int master = rta_getattr_u32(tb[IFLA_MASTER]);
 238
 239                 print_string(PRINT_ANY, "master", "master %s ",
 240                              ll_index_to_name(master));
 241         }
 242
 243         if (tb[IFLA_PROTINFO])
 244                 print_protinfo(fp, tb[IFLA_PROTINFO]);
 245
 246         if (tb[IFLA_AF_SPEC])
 247                 print_af_spec(tb[IFLA_AF_SPEC], ifi->ifi_index);
 248
 249         print_string(PRINT_FP, NULL, "%s", "\n");
 250         close_json_object();
 251         fflush(fp);
 252         return 0;
 253 }
 254
 255 static void usage(void)
 256 {
 257         fprintf(stderr,
 258                 "Usage: bridge link set dev DEV [ cost COST ] [ priority PRIO ] [ state STATE ]\n"
 259                 "                               [ guard {on | off} ]\n"
 260                 "                               [ hairpin {on | off} ]\n"
 261                 "                               [ fastleave {on | off} ]\n"
 262                 "                               [ root_block {on | off} ]\n"
 263                 "                               [ learning {on | off} ]\n"
 264                 "                               [ learning_sync {on | off} ]\n"
 265                 "                               [ flood {on | off} ]\n"
 266                 "                               [ mcast_flood {on | off} ]\n"
 267                 "                               [ mcast_to_unicast {on | off} ]\n"
 268                 "                               [ neigh_suppress {on | off} ]\n"
 269                 "                               [ vlan_tunnel {on | off} ]\n"
 270                 "                               [ isolated {on | off} ]\n"
 271                 "                               [ hwmode {vepa | veb} ]\n"
 272                 "                               [ backup_port DEVICE ] [ nobackup_port ]\n"
 273                 "                               [ self ] [ master ]\n"
 274                 "       bridge link show [dev DEV]\n");
 275         exit(-1);
 276 }
 277
 278 static bool on_off(char *arg, __s8 *attr, char *val)
 279 {
 280         if (strcmp(val, "on") == 0)
 281                 *attr = 1;
 282         else if (strcmp(val, "off") == 0)
 283                 *attr = 0;
 284         else {
 285                 fprintf(stderr,
 286                         "Error: argument of \"%s\" must be \"on\" or \"off\"\n",
 287                         arg);
 288                 return false;
 289         }
 290
 291         return true;
 292 }
 293
 294 static int brlink_modify(int argc, char **argv)
 295 {
 296         struct {
 297                 struct nlmsghdr  n;
 298                 struct ifinfomsg ifm;
 299                 char             buf[512];
 300         } req = {
 301                 .n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
 302                 .n.nlmsg_flags = NLM_F_REQUEST,
 303                 .n.nlmsg_type = RTM_SETLINK,
 304                 .ifm.ifi_family = PF_BRIDGE,
 305         };
 306         char *d = NULL;
 307         int backup_port_idx = -1;
 308         __s8 neigh_suppress = -1;
 309         __s8 learning = -1;
 310         __s8 learning_sync = -1;
 311         __s8 flood = -1;
 312         __s8 vlan_tunnel = -1;
 313         __s8 mcast_flood = -1;
 314         __s8 mcast_to_unicast = -1;
 315         __s8 isolated = -1;
 316         __s8 hairpin = -1;
 317         __s8 bpdu_guard = -1;
 318         __s8 fast_leave = -1;
 319         __s8 root_block = -1;
 320         __u32 cost = 0;
 321         __s16 priority = -1;
 322         __s8 state = -1;
 323         __s16 mode = -1;
 324         __u16 flags = 0;
 325         struct rtattr *nest;
 326
 327         while (argc > 0) {
 328                 if (strcmp(*argv, "dev") == 0) {
 329                         NEXT_ARG();
 330                         d = *argv;
 331                 } else if (strcmp(*argv, "guard") == 0) {
 332                         NEXT_ARG();
 333                         if (!on_off("guard", &bpdu_guard, *argv))
 334                                 return -1;
 335                 } else if (strcmp(*argv, "hairpin") == 0) {
 336                         NEXT_ARG();
 337                         if (!on_off("hairpin", &hairpin, *argv))
 338                                 return -1;
 339                 } else if (strcmp(*argv, "fastleave") == 0) {
 340                         NEXT_ARG();
 341                         if (!on_off("fastleave", &fast_leave, *argv))
 342                                 return -1;
 343                 } else if (strcmp(*argv, "root_block") == 0) {
 344                         NEXT_ARG();
 345                         if (!on_off("root_block", &root_block, *argv))
 346                                 return -1;
 347                 } else if (strcmp(*argv, "learning") == 0) {
 348                         NEXT_ARG();
 349                         if (!on_off("learning", &learning, *argv))
 350                                 return -1;
 351                 } else if (strcmp(*argv, "learning_sync") == 0) {
 352                         NEXT_ARG();
 353                         if (!on_off("learning_sync", &learning_sync, *argv))
 354                                 return -1;
 355                 } else if (strcmp(*argv, "flood") == 0) {
 356                         NEXT_ARG();
 357                         if (!on_off("flood", &flood, *argv))
 358                                 return -1;
 359                 } else if (strcmp(*argv, "mcast_flood") == 0) {
 360                         NEXT_ARG();
 361                         if (!on_off("mcast_flood", &mcast_flood, *argv))
 362                                 return -1;
 363                 } else if (strcmp(*argv, "mcast_to_unicast") == 0) {
 364                         NEXT_ARG();
 365                         if (!on_off("mcast_to_unicast", &mcast_to_unicast, *argv))
 366                                 return -1;
 367                 } else if (strcmp(*argv, "cost") == 0) {
 368                         NEXT_ARG();
 369                         cost = atoi(*argv);
 370                 } else if (strcmp(*argv, "priority") == 0) {
 371                         NEXT_ARG();
 372                         priority = atoi(*argv);
 373                 } else if (strcmp(*argv, "state") == 0) {
 374                         NEXT_ARG();
 375                         char *endptr;
 376                         size_t nstates = ARRAY_SIZE(port_states);
 377
 378                         state = strtol(*argv, &endptr, 10);
 379                         if (!(**argv != '\0' && *endptr == '\0')) {
 380                                 for (state = 0; state < nstates; state++)
 381                                         if (strcmp(port_states[state], *argv) == 0)
 382                                                 break;
 383                                 if (state == nstates) {
 384                                         fprintf(stderr,
 385                                                 "Error: invalid STP port state\n");
 386                                         return -1;
 387                                 }
 388                         }
 389                 } else if (strcmp(*argv, "hwmode") == 0) {
 390                         NEXT_ARG();
 391                         flags = BRIDGE_FLAGS_SELF;
 392                         if (strcmp(*argv, "vepa") == 0)
 393                                 mode = BRIDGE_MODE_VEPA;
 394                         else if (strcmp(*argv, "veb") == 0)
 395                                 mode = BRIDGE_MODE_VEB;
 396                         else {
 397                                 fprintf(stderr,
 398                                         "Mode argument must be \"vepa\" or \"veb\".\n");
 399                                 return -1;
 400                         }
 401                 } else if (strcmp(*argv, "self") == 0) {
 402                         flags |= BRIDGE_FLAGS_SELF;
 403                 } else if (strcmp(*argv, "master") == 0) {
 404                         flags |= BRIDGE_FLAGS_MASTER;
 405                 } else if (strcmp(*argv, "neigh_suppress") == 0) {
 406                         NEXT_ARG();
 407                         if (!on_off("neigh_suppress", &neigh_suppress,
 408                                     *argv))
 409                                 return -1;
 410                 } else if (strcmp(*argv, "vlan_tunnel") == 0) {
 411                         NEXT_ARG();
 412                         if (!on_off("vlan_tunnel", &vlan_tunnel,
 413                                     *argv))
 414                                 return -1;
 415                 } else if (strcmp(*argv, "isolated") == 0) {
 416                         NEXT_ARG();
 417                         if (!on_off("isolated", &isolated, *argv))
 418                                 return -1;
 419                 } else if (strcmp(*argv, "backup_port") == 0) {
 420                         NEXT_ARG();
 421                         backup_port_idx = ll_name_to_index(*argv);
 422                         if (!backup_port_idx) {
 423                                 fprintf(stderr, "Error: device %s does not exist\n",
 424                                         *argv);
 425                                 return -1;
 426                         }
 427                 } else if (strcmp(*argv, "nobackup_port") == 0) {
 428                         backup_port_idx = 0;
 429                 } else {
 430                         usage();
 431                 }
 432                 argc--; argv++;
 433         }
 434         if (d == NULL) {
 435                 fprintf(stderr, "Device is a required argument.\n");
 436                 return -1;
 437         }
 438
 439
 440         req.ifm.ifi_index = ll_name_to_index(d);
 441         if (req.ifm.ifi_index == 0) {
 442                 fprintf(stderr, "Cannot find bridge device \"%s\"\n", d);
 443                 return -1;
 444         }
 445
 446         /* Nested PROTINFO attribute.  Contains: port flags, cost, priority and
 447          * state.
 448          */
 449         nest = addattr_nest(&req.n, sizeof(req),
 450                             IFLA_PROTINFO | NLA_F_NESTED);
 451         /* Flags first */
 452         if (bpdu_guard >= 0)
 453                 addattr8(&req.n, sizeof(req), IFLA_BRPORT_GUARD, bpdu_guard);
 454         if (hairpin >= 0)
 455                 addattr8(&req.n, sizeof(req), IFLA_BRPORT_MODE, hairpin);
 456         if (fast_leave >= 0)
 457                 addattr8(&req.n, sizeof(req), IFLA_BRPORT_FAST_LEAVE,
 458                          fast_leave);
 459         if (root_block >= 0)
 460                 addattr8(&req.n, sizeof(req), IFLA_BRPORT_PROTECT, root_block);
 461         if (flood >= 0)
 462                 addattr8(&req.n, sizeof(req), IFLA_BRPORT_UNICAST_FLOOD, flood);
 463         if (mcast_flood >= 0)
 464                 addattr8(&req.n, sizeof(req), IFLA_BRPORT_MCAST_FLOOD,
 465                          mcast_flood);
 466         if (mcast_to_unicast >= 0)
 467                 addattr8(&req.n, sizeof(req), IFLA_BRPORT_MCAST_TO_UCAST,
 468                          mcast_to_unicast);
 469         if (learning >= 0)
 470                 addattr8(&req.n, sizeof(req), IFLA_BRPORT_LEARNING, learning);
 471         if (learning_sync >= 0)
 472                 addattr8(&req.n, sizeof(req), IFLA_BRPORT_LEARNING_SYNC,
 473                          learning_sync);
 474
 475         if (cost > 0)
 476                 addattr32(&req.n, sizeof(req), IFLA_BRPORT_COST, cost);
 477
 478         if (priority >= 0)
 479                 addattr16(&req.n, sizeof(req), IFLA_BRPORT_PRIORITY, priority);
 480
 481         if (state >= 0)
 482                 addattr8(&req.n, sizeof(req), IFLA_BRPORT_STATE, state);
 483
 484         if (neigh_suppress != -1)
 485                 addattr8(&req.n, sizeof(req), IFLA_BRPORT_NEIGH_SUPPRESS,
 486                          neigh_suppress);
 487         if (vlan_tunnel != -1)
 488                 addattr8(&req.n, sizeof(req), IFLA_BRPORT_VLAN_TUNNEL,
 489                          vlan_tunnel);
 490         if (isolated != -1)
 491                 addattr8(&req.n, sizeof(req), IFLA_BRPORT_ISOLATED, isolated);
 492
 493         if (backup_port_idx != -1)
 494                 addattr32(&req.n, sizeof(req), IFLA_BRPORT_BACKUP_PORT,
 495                           backup_port_idx);
 496
 497         addattr_nest_end(&req.n, nest);
 498
 499         /* IFLA_AF_SPEC nested attribute. Contains IFLA_BRIDGE_FLAGS that
 500          * designates master or self operation and IFLA_BRIDGE_MODE
 501          * for hw 'vepa' or 'veb' operation modes. The hwmodes are
 502          * only valid in 'self' mode on some devices so far.
 503          */
 504         if (mode >= 0 || flags > 0) {
 505                 nest = addattr_nest(&req.n, sizeof(req), IFLA_AF_SPEC);
 506
 507                 if (flags > 0)
 508                         addattr16(&req.n, sizeof(req), IFLA_BRIDGE_FLAGS, flags);
 509
 510                 if (mode >= 0)
 511                         addattr16(&req.n, sizeof(req), IFLA_BRIDGE_MODE, mode);
 512
 513                 addattr_nest_end(&req.n, nest);
 514         }
 515
 516         if (rtnl_talk(&rth, &req.n, NULL) < 0)
 517                 return -1;
 518
 519         return 0;
 520 }
 521
 522 static int brlink_show(int argc, char **argv)
 523 {
 524         char *filter_dev = NULL;
 525
 526         while (argc > 0) {
 527                 if (strcmp(*argv, "dev") == 0) {
 528                         NEXT_ARG();
 529                         if (filter_dev)
 530                                 duparg("dev", *argv);
 531                         filter_dev = *argv;
 532                 }
 533                 argc--; argv++;
 534         }
 535
 536         if (filter_dev) {
 537                 filter_index = ll_name_to_index(filter_dev);
 538                 if (!filter_index)
 539                         return nodev(filter_dev);
 540         }
 541
 542         if (show_details) {
 543                 if (rtnl_linkdump_req_filter(&rth, PF_BRIDGE,
 544                                              (compress_vlans ?
 545                                               RTEXT_FILTER_BRVLAN_COMPRESSED :
 546                                               RTEXT_FILTER_BRVLAN)) < 0) {
 547                         perror("Cannon send dump request");
 548                         exit(1);
 549                 }
 550         } else {
 551                 if (rtnl_linkdump_req(&rth, PF_BRIDGE) < 0) {
 552                         perror("Cannon send dump request");
 553                         exit(1);
 554                 }
 555         }
 556
 557         new_json_obj(json);
 558         if (rtnl_dump_filter(&rth, print_linkinfo, stdout) < 0) {
 559                 fprintf(stderr, "Dump terminated\n");
 560                 exit(1);
 561         }
 562
 563         delete_json_obj();
 564         fflush(stdout);
 565         return 0;
 566 }
 567
 568 int do_link(int argc, char **argv)
 569 {
 570         ll_init_map(&rth);
 571         if (argc > 0) {
 572                 if (matches(*argv, "set") == 0 ||
 573                     matches(*argv, "change") == 0)
 574                         return brlink_modify(argc-1, argv+1);
 575                 if (matches(*argv, "show") == 0 ||
 576                     matches(*argv, "lst") == 0 ||
 577                     matches(*argv, "list") == 0)
 578                         return brlink_show(argc-1, argv+1);
 579                 if (matches(*argv, "help") == 0)
 580                         usage();
 581         } else
 582                 return brlink_show(0, NULL);
 583
 584         fprintf(stderr, "Command \"%s\" is unknown, try \"bridge link help\".\n", *argv);
 585         exit(-1);
 586 }