ip/iplink.c

   1 /*
   2  * iplink.c             "ip link".
   3  *
   4  *              This program is free software; you can redistribute it and/or
   5  *              modify it under the terms of the GNU General Public License
   6  *              as published by the Free Software Foundation; either version
   7  *              2 of the License, or (at your option) any later version.
   8  *
   9  * Authors:     Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
  10  *
  11  */
  12
  13 #include <stdio.h>
  14 #include <stdlib.h>
  15 #include <unistd.h>
  16 #include <syslog.h>
  17 #include <fcntl.h>
  18 #include <dlfcn.h>
  19 #include <errno.h>
  20 #include <sys/socket.h>
  21 #include <linux/if.h>
  22 #include <linux/if_packet.h>
  23 #include <linux/if_ether.h>
  24 #include <linux/sockios.h>
  25 #include <netinet/in.h>
  26 #include <arpa/inet.h>
  27 #include <string.h>
  28 #include <sys/ioctl.h>
  29 #include <linux/sockios.h>
  30
  31 #include "rt_names.h"
  32 #include "utils.h"
  33 #include "ip_common.h"
  34
  35 #define IPLINK_IOCTL_COMPAT     1
  36
  37 static void usage(void) __attribute__((noreturn));
  38
  39 void iplink_usage(void)
  40 {
  41         fprintf(stderr, "Usage: ip link set DEVICE { up | down |\n");
  42         fprintf(stderr, "                            arp { on | off } |\n");
  43         fprintf(stderr, "                            dynamic { on | off } |\n");
  44         fprintf(stderr, "                            multicast { on | off } |\n");
  45         fprintf(stderr, "                            allmulticast { on | off } |\n");
  46         fprintf(stderr, "                            promisc { on | off } |\n");
  47         fprintf(stderr, "                            trailers { on | off } |\n");
  48         fprintf(stderr, "                            txqueuelen PACKETS |\n");
  49         fprintf(stderr, "                            name NEWNAME |\n");
  50         fprintf(stderr, "                            address LLADDR | broadcast LLADDR |\n");
  51         fprintf(stderr, "                            mtu MTU }\n");
  52         fprintf(stderr, "       ip link show [ DEVICE ]\n");
  53         exit(-1);
  54 }
  55
  56 static void usage(void)
  57 {
  58         iplink_usage();
  59 }
  60
  61 static int on_off(char *msg)
  62 {
  63         fprintf(stderr, "Error: argument of \"%s\" must be \"on\" or \"off\"\n", msg);
  64         return -1;
  65 }
  66
  67 static void *BODY;              /* cached dlopen(NULL) handle */
  68 static struct link_util *linkutil_list;
  69
  70 struct link_util *get_link_kind(const char *id)
  71 {
  72         void *dlh;
  73         char buf[256];
  74         struct link_util *l;
  75
  76         for (l = linkutil_list; l; l = l->next)
  77                 if (strcmp(l->id, id) == 0)
  78                         return l;
  79
  80         snprintf(buf, sizeof(buf), "/usr/lib/ip/link_%s.so", id);
  81         dlh = dlopen(buf, RTLD_LAZY);
  82         if (dlh == NULL) {
  83                 /* look in current binary, only open once */
  84                 dlh = BODY;
  85                 if (dlh == NULL) {
  86                         dlh = BODY = dlopen(NULL, RTLD_LAZY);
  87                         if (dlh == NULL)
  88                                 return NULL;
  89                 }
  90         }
  91
  92         snprintf(buf, sizeof(buf), "%s_link_util", id);
  93         l = dlsym(dlh, buf);
  94         if (l == NULL)
  95                 return NULL;
  96
  97         l->next = linkutil_list;
  98         linkutil_list = l;
  99         return l;
 100 }
 101
 102 #if IPLINK_IOCTL_COMPAT
 103 static int have_rtnl_newlink = -1;
 104
 105 static int accept_msg(const struct sockaddr_nl *who,
 106                       struct nlmsghdr *n, void *arg)
 107 {
 108         struct nlmsgerr *err = (struct nlmsgerr *)NLMSG_DATA(n);
 109
 110         if (n->nlmsg_type == NLMSG_ERROR &&
 111             (err->error == -EOPNOTSUPP || err->error == -EINVAL))
 112                 have_rtnl_newlink = 0;
 113         else
 114                 have_rtnl_newlink = 1;
 115         return -1;
 116 }
 117
 118 static int iplink_have_newlink(void)
 119 {
 120         struct {
 121                 struct nlmsghdr         n;
 122                 struct ifinfomsg        i;
 123                 char                    buf[1024];
 124         } req;
 125
 126         if (have_rtnl_newlink < 0) {
 127                 memset(&req, 0, sizeof(req));
 128
 129                 req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
 130                 req.n.nlmsg_flags = NLM_F_REQUEST|NLM_F_ACK;
 131                 req.n.nlmsg_type = RTM_NEWLINK;
 132                 req.i.ifi_family = AF_UNSPEC;
 133
 134                 rtnl_send(&rth, (char *)&req.n, req.n.nlmsg_len);
 135                 rtnl_listen(&rth, accept_msg, NULL);
 136         }
 137         return have_rtnl_newlink;
 138 }
 139 #else /* IPLINK_IOCTL_COMPAT */
 140 static int iplink_have_newlink(void)
 141 {
 142         return 1;
 143 }
 144 #endif /* ! IPLINK_IOCTL_COMPAT */
 145
 146 struct iplink_req {
 147         struct nlmsghdr         n;
 148         struct ifinfomsg        i;
 149         char                    buf[1024];
 150 };
 151
 152 int iplink_parse(int argc, char **argv, struct iplink_req *req,
 153                 char **name, char **type, char **link, char **dev)
 154 {
 155         int ret, len;
 156         char abuf[32];
 157         int qlen = -1;
 158         int mtu = -1;
 159
 160         ret = argc;
 161
 162         while (argc > 0) {
 163                 if (strcmp(*argv, "up") == 0) {
 164                         req->i.ifi_change |= IFF_UP;
 165                         req->i.ifi_flags |= IFF_UP;
 166                 } else if (strcmp(*argv, "down") == 0) {
 167                         req->i.ifi_change |= IFF_UP;
 168                         req->i.ifi_flags &= ~IFF_UP;
 169                 } else if (strcmp(*argv, "name") == 0) {
 170                         NEXT_ARG();
 171                         *name = *argv;
 172                 } else if (matches(*argv, "link") == 0) {
 173                         NEXT_ARG();
 174                         *link = *argv;
 175                 } else if (matches(*argv, "address") == 0) {
 176                         NEXT_ARG();
 177                         len = ll_addr_a2n(abuf, sizeof(abuf), *argv);
 178                         addattr_l(&req->n, sizeof(*req), IFLA_ADDRESS, abuf, len);
 179                 } else if (matches(*argv, "broadcast") == 0 ||
 180                                 strcmp(*argv, "brd") == 0) {
 181                         NEXT_ARG();
 182                         len = ll_addr_a2n(abuf, sizeof(abuf), *argv);
 183                         addattr_l(&req->n, sizeof(*req), IFLA_BROADCAST, abuf, len);
 184                 } else if (matches(*argv, "txqueuelen") == 0 ||
 185                                 strcmp(*argv, "qlen") == 0 ||
 186                                 matches(*argv, "txqlen") == 0) {
 187                         NEXT_ARG();
 188                         if (qlen != -1)
 189                                 duparg("txqueuelen", *argv);
 190                         if (get_integer(&qlen,  *argv, 0))
 191                                 invarg("Invalid \"txqueuelen\" value\n", *argv);
 192                         addattr_l(&req->n, sizeof(*req), IFLA_TXQLEN, &qlen, 4);
 193                 } else if (strcmp(*argv, "mtu") == 0) {
 194                         NEXT_ARG();
 195                         if (mtu != -1)
 196                                 duparg("mtu", *argv);
 197                         if (get_integer(&mtu, *argv, 0))
 198                                 invarg("Invalid \"mtu\" value\n", *argv);
 199                         addattr_l(&req->n, sizeof(*req), IFLA_MTU, &mtu, 4);
 200                 } else if (strcmp(*argv, "multicast") == 0) {
 201                         NEXT_ARG();
 202                         req->i.ifi_change |= IFF_MULTICAST;
 203                         if (strcmp(*argv, "on") == 0) {
 204                                 req->i.ifi_flags |= IFF_MULTICAST;
 205                         } else if (strcmp(*argv, "off") == 0) {
 206                                 req->i.ifi_flags &= ~IFF_MULTICAST;
 207                         } else
 208                                 return on_off("multicast");
 209                 } else if (strcmp(*argv, "allmulticast") == 0) {
 210                         NEXT_ARG();
 211                         req->i.ifi_change |= IFF_ALLMULTI;
 212                         if (strcmp(*argv, "on") == 0) {
 213                                 req->i.ifi_flags |= IFF_ALLMULTI;
 214                         } else if (strcmp(*argv, "off") == 0) {
 215                                 req->i.ifi_flags &= ~IFF_ALLMULTI;
 216                         } else
 217                                 return on_off("allmulticast");
 218                 } else if (strcmp(*argv, "promisc") == 0) {
 219                         NEXT_ARG();
 220                         req->i.ifi_change |= IFF_PROMISC;
 221                         if (strcmp(*argv, "on") == 0) {
 222                                 req->i.ifi_flags |= IFF_PROMISC;
 223                         } else if (strcmp(*argv, "off") == 0) {
 224                                 req->i.ifi_flags &= ~IFF_PROMISC;
 225                         } else
 226                                 return on_off("promisc");
 227                 } else if (strcmp(*argv, "trailers") == 0) {
 228                         NEXT_ARG();
 229                         req->i.ifi_change |= IFF_NOTRAILERS;
 230                         if (strcmp(*argv, "off") == 0) {
 231                                 req->i.ifi_flags |= IFF_NOTRAILERS;
 232                         } else if (strcmp(*argv, "on") == 0) {
 233                                 req->i.ifi_flags &= ~IFF_NOTRAILERS;
 234                         } else
 235                                 return on_off("trailers");
 236                 } else if (strcmp(*argv, "arp") == 0) {
 237                         NEXT_ARG();
 238                         req->i.ifi_change |= IFF_NOARP;
 239                         if (strcmp(*argv, "on") == 0) {
 240                                 req->i.ifi_flags &= ~IFF_NOARP;
 241                         } else if (strcmp(*argv, "off") == 0) {
 242                                 req->i.ifi_flags |= IFF_NOARP;
 243                         } else
 244                                 return on_off("noarp");
 245 #ifdef IFF_DYNAMIC
 246                 } else if (matches(*argv, "dynamic") == 0) {
 247                         NEXT_ARG();
 248                         req->i.ifi_change |= IFF_DYNAMIC;
 249                         if (strcmp(*argv, "on") == 0) {
 250                                 req->i.ifi_flags |= IFF_DYNAMIC;
 251                         } else if (strcmp(*argv, "off") == 0) {
 252                                 req->i.ifi_flags &= ~IFF_DYNAMIC;
 253                         } else
 254                                 return on_off("dynamic");
 255 #endif
 256                 } else if (matches(*argv, "type") == 0) {
 257                         NEXT_ARG();
 258                         *type = *argv;
 259                         argc--; argv++;
 260                         break;
 261                 } else {
 262                         if (strcmp(*argv, "dev") == 0) {
 263                                 NEXT_ARG();
 264                         }
 265                         if (*dev)
 266                                 duparg2("dev", *argv);
 267                         *dev = *argv;
 268                 }
 269                 argc--; argv++;
 270         }
 271
 272         return ret - argc;
 273 }
 274
 275 static int iplink_modify(int cmd, unsigned int flags, int argc, char **argv)
 276 {
 277         int len;
 278         char *dev = NULL;
 279         char *name = NULL;
 280         char *link = NULL;
 281         char *type = NULL;
 282         struct link_util *lu = NULL;
 283         struct iplink_req req;
 284         int ret;
 285
 286         memset(&req, 0, sizeof(req));
 287
 288         req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
 289         req.n.nlmsg_flags = NLM_F_REQUEST|flags;
 290         req.n.nlmsg_type = cmd;
 291         req.i.ifi_family = preferred_family;
 292
 293         ret = iplink_parse(argc, argv, &req, &name, &type, &link, &dev);
 294         if (ret < 0)
 295                 return ret;
 296
 297         argc -= ret;
 298         argv += ret;
 299         ll_init_map(&rth);
 300
 301         if (type) {
 302                 struct rtattr *linkinfo = NLMSG_TAIL(&req.n);
 303                 addattr_l(&req.n, sizeof(req), IFLA_LINKINFO, NULL, 0);
 304                 addattr_l(&req.n, sizeof(req), IFLA_INFO_KIND, type,
 305                          strlen(type));
 306
 307                 lu = get_link_kind(type);
 308                 if (lu && argc) {
 309                         struct rtattr * data = NLMSG_TAIL(&req.n);
 310                         addattr_l(&req.n, sizeof(req), IFLA_INFO_DATA, NULL, 0);
 311
 312                         if (lu->parse_opt &&
 313                             lu->parse_opt(lu, argc, argv, &req.n))
 314                                 return -1;
 315
 316                         data->rta_len = (void *)NLMSG_TAIL(&req.n) - (void *)data;
 317                 } else if (argc) {
 318                         if (matches(*argv, "help") == 0)
 319                                 usage();
 320                         fprintf(stderr, "Garbage instead of arguments \"%s ...\". "
 321                                         "Try \"ip link help\".\n", *argv);
 322                         return -1;
 323                 }
 324                 linkinfo->rta_len = (void *)NLMSG_TAIL(&req.n) - (void *)linkinfo;
 325         }
 326
 327         if (!(flags & NLM_F_CREATE)) {
 328                 if (!dev) {
 329                         fprintf(stderr, "Not enough information: \"dev\" "
 330                                         "argument is required.\n");
 331                         exit(-1);
 332                 }
 333
 334                 req.i.ifi_index = ll_name_to_index(dev);
 335                 if (req.i.ifi_index == 0) {
 336                         fprintf(stderr, "Cannot find device \"%s\"\n", dev);
 337                         return -1;
 338                 }
 339         } else {
 340                 /* Allow "ip link add dev" and "ip link add name" */
 341                 if (!name)
 342                         name = dev;
 343
 344                 if (link) {
 345                         int ifindex;
 346
 347                         ifindex = ll_name_to_index(link);
 348                         if (ifindex == 0) {
 349                                 fprintf(stderr, "Cannot find device \"%s\"\n",
 350                                         link);
 351                                 return -1;
 352                         }
 353                         addattr_l(&req.n, sizeof(req), IFLA_LINK, &ifindex, 4);
 354                 }
 355         }
 356
 357         if (name) {
 358                 len = strlen(name) + 1;
 359                 if (len == 1)
 360                         invarg("\"\" is not a valid device identifier\n", "name");
 361                 if (len > IFNAMSIZ)
 362                         invarg("\"name\" too long\n", name);
 363                 addattr_l(&req.n, sizeof(req), IFLA_IFNAME, name, len);
 364         }
 365
 366         if (rtnl_talk(&rth, &req.n, 0, 0, NULL, NULL, NULL) < 0)
 367                 exit(2);
 368
 369         return 0;
 370 }
 371
 372 #if IPLINK_IOCTL_COMPAT
 373 static int get_ctl_fd(void)
 374 {
 375         int s_errno;
 376         int fd;
 377
 378         fd = socket(PF_INET, SOCK_DGRAM, 0);
 379         if (fd >= 0)
 380                 return fd;
 381         s_errno = errno;
 382         fd = socket(PF_PACKET, SOCK_DGRAM, 0);
 383         if (fd >= 0)
 384                 return fd;
 385         fd = socket(PF_INET6, SOCK_DGRAM, 0);
 386         if (fd >= 0)
 387                 return fd;
 388         errno = s_errno;
 389         perror("Cannot create control socket");
 390         return -1;
 391 }
 392
 393 static int do_chflags(const char *dev, __u32 flags, __u32 mask)
 394 {
 395         struct ifreq ifr;
 396         int fd;
 397         int err;
 398
 399         strncpy(ifr.ifr_name, dev, IFNAMSIZ);
 400         fd = get_ctl_fd();
 401         if (fd < 0)
 402                 return -1;
 403         err = ioctl(fd, SIOCGIFFLAGS, &ifr);
 404         if (err) {
 405                 perror("SIOCGIFFLAGS");
 406                 close(fd);
 407                 return -1;
 408         }
 409         if ((ifr.ifr_flags^flags)&mask) {
 410                 ifr.ifr_flags &= ~mask;
 411                 ifr.ifr_flags |= mask&flags;
 412                 err = ioctl(fd, SIOCSIFFLAGS, &ifr);
 413                 if (err)
 414                         perror("SIOCSIFFLAGS");
 415         }
 416         close(fd);
 417         return err;
 418 }
 419
 420 static int do_changename(const char *dev, const char *newdev)
 421 {
 422         struct ifreq ifr;
 423         int fd;
 424         int err;
 425
 426         strncpy(ifr.ifr_name, dev, IFNAMSIZ);
 427         strncpy(ifr.ifr_newname, newdev, IFNAMSIZ);
 428         fd = get_ctl_fd();
 429         if (fd < 0)
 430                 return -1;
 431         err = ioctl(fd, SIOCSIFNAME, &ifr);
 432         if (err) {
 433                 perror("SIOCSIFNAME");
 434                 close(fd);
 435                 return -1;
 436         }
 437         close(fd);
 438         return err;
 439 }
 440
 441 static int set_qlen(const char *dev, int qlen)
 442 {
 443         struct ifreq ifr;
 444         int s;
 445
 446         s = get_ctl_fd();
 447         if (s < 0)
 448                 return -1;
 449
 450         memset(&ifr, 0, sizeof(ifr));
 451         strncpy(ifr.ifr_name, dev, IFNAMSIZ);
 452         ifr.ifr_qlen = qlen;
 453         if (ioctl(s, SIOCSIFTXQLEN, &ifr) < 0) {
 454                 perror("SIOCSIFXQLEN");
 455                 close(s);
 456                 return -1;
 457         }
 458         close(s);
 459
 460         return 0;
 461 }
 462
 463 static int set_mtu(const char *dev, int mtu)
 464 {
 465         struct ifreq ifr;
 466         int s;
 467
 468         s = get_ctl_fd();
 469         if (s < 0)
 470                 return -1;
 471
 472         memset(&ifr, 0, sizeof(ifr));
 473         strncpy(ifr.ifr_name, dev, IFNAMSIZ);
 474         ifr.ifr_mtu = mtu;
 475         if (ioctl(s, SIOCSIFMTU, &ifr) < 0) {
 476                 perror("SIOCSIFMTU");
 477                 close(s);
 478                 return -1;
 479         }
 480         close(s);
 481
 482         return 0;
 483 }
 484
 485 static int get_address(const char *dev, int *htype)
 486 {
 487         struct ifreq ifr;
 488         struct sockaddr_ll me;
 489         socklen_t alen;
 490         int s;
 491
 492         s = socket(PF_PACKET, SOCK_DGRAM, 0);
 493         if (s < 0) {
 494                 perror("socket(PF_PACKET)");
 495                 return -1;
 496         }
 497
 498         memset(&ifr, 0, sizeof(ifr));
 499         strncpy(ifr.ifr_name, dev, IFNAMSIZ);
 500         if (ioctl(s, SIOCGIFINDEX, &ifr) < 0) {
 501                 perror("SIOCGIFINDEX");
 502                 close(s);
 503                 return -1;
 504         }
 505
 506         memset(&me, 0, sizeof(me));
 507         me.sll_family = AF_PACKET;
 508         me.sll_ifindex = ifr.ifr_ifindex;
 509         me.sll_protocol = htons(ETH_P_LOOP);
 510         if (bind(s, (struct sockaddr*)&me, sizeof(me)) == -1) {
 511                 perror("bind");
 512                 close(s);
 513                 return -1;
 514         }
 515
 516         alen = sizeof(me);
 517         if (getsockname(s, (struct sockaddr*)&me, &alen) == -1) {
 518                 perror("getsockname");
 519                 close(s);
 520                 return -1;
 521         }
 522         close(s);
 523         *htype = me.sll_hatype;
 524         return me.sll_halen;
 525 }
 526
 527 static int parse_address(const char *dev, int hatype, int halen,
 528                 char *lla, struct ifreq *ifr)
 529 {
 530         int alen;
 531
 532         memset(ifr, 0, sizeof(*ifr));
 533         strncpy(ifr->ifr_name, dev, IFNAMSIZ);
 534         ifr->ifr_hwaddr.sa_family = hatype;
 535         alen = ll_addr_a2n(ifr->ifr_hwaddr.sa_data, 14, lla);
 536         if (alen < 0)
 537                 return -1;
 538         if (alen != halen) {
 539                 fprintf(stderr, "Wrong address (%s) length: expected %d bytes\n", lla, halen);
 540                 return -1;
 541         }
 542         return 0;
 543 }
 544
 545 static int set_address(struct ifreq *ifr, int brd)
 546 {
 547         int s;
 548
 549         s = get_ctl_fd();
 550         if (s < 0)
 551                 return -1;
 552         if (ioctl(s, brd?SIOCSIFHWBROADCAST:SIOCSIFHWADDR, ifr) < 0) {
 553                 perror(brd?"SIOCSIFHWBROADCAST":"SIOCSIFHWADDR");
 554                 close(s);
 555                 return -1;
 556         }
 557         close(s);
 558         return 0;
 559 }
 560
 561
 562 static int do_set(int argc, char **argv)
 563 {
 564         char *dev = NULL;
 565         __u32 mask = 0;
 566         __u32 flags = 0;
 567         int qlen = -1;
 568         int mtu = -1;
 569         char *newaddr = NULL;
 570         char *newbrd = NULL;
 571         struct ifreq ifr0, ifr1;
 572         char *newname = NULL;
 573         int htype, halen;
 574
 575         while (argc > 0) {
 576                 if (strcmp(*argv, "up") == 0) {
 577                         mask |= IFF_UP;
 578                         flags |= IFF_UP;
 579                 } else if (strcmp(*argv, "down") == 0) {
 580                         mask |= IFF_UP;
 581                         flags &= ~IFF_UP;
 582                 } else if (strcmp(*argv, "name") == 0) {
 583                         NEXT_ARG();
 584                         newname = *argv;
 585                 } else if (matches(*argv, "address") == 0) {
 586                         NEXT_ARG();
 587                         newaddr = *argv;
 588                 } else if (matches(*argv, "broadcast") == 0 ||
 589                            strcmp(*argv, "brd") == 0) {
 590                         NEXT_ARG();
 591                         newbrd = *argv;
 592                 } else if (matches(*argv, "txqueuelen") == 0 ||
 593                            strcmp(*argv, "qlen") == 0 ||
 594                            matches(*argv, "txqlen") == 0) {
 595                         NEXT_ARG();
 596                         if (qlen != -1)
 597                                 duparg("txqueuelen", *argv);
 598                         if (get_integer(&qlen,  *argv, 0))
 599                                 invarg("Invalid \"txqueuelen\" value\n", *argv);
 600                 } else if (strcmp(*argv, "mtu") == 0) {
 601                         NEXT_ARG();
 602                         if (mtu != -1)
 603                                 duparg("mtu", *argv);
 604                         if (get_integer(&mtu, *argv, 0))
 605                                 invarg("Invalid \"mtu\" value\n", *argv);
 606                 } else if (strcmp(*argv, "multicast") == 0) {
 607                         NEXT_ARG();
 608                         mask |= IFF_MULTICAST;
 609                         if (strcmp(*argv, "on") == 0) {
 610                                 flags |= IFF_MULTICAST;
 611                         } else if (strcmp(*argv, "off") == 0) {
 612                                 flags &= ~IFF_MULTICAST;
 613                         } else
 614                                 return on_off("multicast");
 615                 } else if (strcmp(*argv, "allmulticast") == 0) {
 616                         NEXT_ARG();
 617                         mask |= IFF_ALLMULTI;
 618                         if (strcmp(*argv, "on") == 0) {
 619                                 flags |= IFF_ALLMULTI;
 620                         } else if (strcmp(*argv, "off") == 0) {
 621                                 flags &= ~IFF_ALLMULTI;
 622                         } else
 623                                 return on_off("allmulticast");
 624                 } else if (strcmp(*argv, "promisc") == 0) {
 625                         NEXT_ARG();
 626                         mask |= IFF_PROMISC;
 627                         if (strcmp(*argv, "on") == 0) {
 628                                 flags |= IFF_PROMISC;
 629                         } else if (strcmp(*argv, "off") == 0) {
 630                                 flags &= ~IFF_PROMISC;
 631                         } else
 632                                 return on_off("promisc");
 633                 } else if (strcmp(*argv, "trailers") == 0) {
 634                         NEXT_ARG();
 635                         mask |= IFF_NOTRAILERS;
 636                         if (strcmp(*argv, "off") == 0) {
 637                                 flags |= IFF_NOTRAILERS;
 638                         } else if (strcmp(*argv, "on") == 0) {
 639                                 flags &= ~IFF_NOTRAILERS;
 640                         } else
 641                                 return on_off("trailers");
 642                 } else if (strcmp(*argv, "arp") == 0) {
 643                         NEXT_ARG();
 644                         mask |= IFF_NOARP;
 645                         if (strcmp(*argv, "on") == 0) {
 646                                 flags &= ~IFF_NOARP;
 647                         } else if (strcmp(*argv, "off") == 0) {
 648                                 flags |= IFF_NOARP;
 649                         } else
 650                                 return on_off("noarp");
 651 #ifdef IFF_DYNAMIC
 652                 } else if (matches(*argv, "dynamic") == 0) {
 653                         NEXT_ARG();
 654                         mask |= IFF_DYNAMIC;
 655                         if (strcmp(*argv, "on") == 0) {
 656                                 flags |= IFF_DYNAMIC;
 657                         } else if (strcmp(*argv, "off") == 0) {
 658                                 flags &= ~IFF_DYNAMIC;
 659                         } else
 660                                 return on_off("dynamic");
 661 #endif
 662                 } else {
 663                         if (strcmp(*argv, "dev") == 0) {
 664                                 NEXT_ARG();
 665                         }
 666                         if (matches(*argv, "help") == 0)
 667                                 usage();
 668                         if (dev)
 669                                 duparg2("dev", *argv);
 670                         dev = *argv;
 671                 }
 672                 argc--; argv++;
 673         }
 674
 675         if (!dev) {
 676                 fprintf(stderr, "Not enough of information: \"dev\" argument is required.\n");
 677                 exit(-1);
 678         }
 679
 680         if (newaddr || newbrd) {
 681                 halen = get_address(dev, &htype);
 682                 if (halen < 0)
 683                         return -1;
 684                 if (newaddr) {
 685                         if (parse_address(dev, htype, halen, newaddr, &ifr0) < 0)
 686                                 return -1;
 687                 }
 688                 if (newbrd) {
 689                         if (parse_address(dev, htype, halen, newbrd, &ifr1) < 0)
 690                                 return -1;
 691                 }
 692         }
 693
 694         if (newname && strcmp(dev, newname)) {
 695                 if (strlen(newname) == 0)
 696                         invarg("\"\" is not a valid device identifier\n", "name");
 697                 if (do_changename(dev, newname) < 0)
 698                         return -1;
 699                 dev = newname;
 700         }
 701         if (qlen != -1) {
 702                 if (set_qlen(dev, qlen) < 0)
 703                         return -1;
 704         }
 705         if (mtu != -1) {
 706                 if (set_mtu(dev, mtu) < 0)
 707                         return -1;
 708         }
 709         if (newaddr || newbrd) {
 710                 if (newbrd) {
 711                         if (set_address(&ifr1, 1) < 0)
 712                                 return -1;
 713                 }
 714                 if (newaddr) {
 715                         if (set_address(&ifr0, 0) < 0)
 716                                 return -1;
 717                 }
 718         }
 719         if (mask)
 720                 return do_chflags(dev, flags, mask);
 721         return 0;
 722 }
 723 #endif /* IPLINK_IOCTL_COMPAT */
 724
 725 int do_iplink(int argc, char **argv)
 726 {
 727         if (argc > 0) {
 728                 if (iplink_have_newlink()) {
 729                         if (matches(*argv, "add") == 0)
 730                                 return iplink_modify(RTM_NEWLINK,
 731                                                      NLM_F_CREATE|NLM_F_EXCL,
 732                                                      argc-1, argv+1);
 733                         if (matches(*argv, "set") == 0 ||
 734                             matches(*argv, "change") == 0)
 735                                 return iplink_modify(RTM_NEWLINK, 0,
 736                                                      argc-1, argv+1);
 737                         if (matches(*argv, "replace") == 0)
 738                                 return iplink_modify(RTM_NEWLINK,
 739                                                      NLM_F_CREATE|NLM_F_REPLACE,
 740                                                      argc-1, argv+1);
 741                         if (matches(*argv, "delete") == 0)
 742                                 return iplink_modify(RTM_DELLINK, 0,
 743                                                      argc-1, argv+1);
 744                 } else {
 745 #if IPLINK_IOCTL_COMPAT
 746                         if (matches(*argv, "set") == 0)
 747                                 return do_set(argc-1, argv+1);
 748 #endif
 749                 }
 750                 if (matches(*argv, "show") == 0 ||
 751                     matches(*argv, "lst") == 0 ||
 752                     matches(*argv, "list") == 0)
 753                         return ipaddr_list_link(argc-1, argv+1);
 754                 if (matches(*argv, "help") == 0)
 755                         usage();
 756         } else
 757                 return ipaddr_list_link(0, NULL);
 758
 759         fprintf(stderr, "Command \"%s\" is unknown, try \"ip link help\".\n", *argv);
 760         exit(-1);
 761 }