ip/iptunnel.c

   1 /*
   2  * iptunnel.c          "ip tunnel"
   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 <string.h>
  16 #include <unistd.h>
  17 #include <sys/types.h>
  18 #include <sys/socket.h>
  19 #include <arpa/inet.h>
  20 #include <sys/ioctl.h>
  21 #include <net/if.h>
  22 #include <net/if_arp.h>
  23 #include <linux/ip.h>
  24 #include <linux/if_tunnel.h>
  25
  26 #include "rt_names.h"
  27 #include "utils.h"
  28 #include "ip_common.h"
  29 #include "tunnel.h"
  30
  31 static void usage(void) __attribute__((noreturn));
  32
  33 static void usage(void)
  34 {
  35         fprintf(stderr, "Usage: ip tunnel { add | change | del | show | prl | 6rd } [ NAME ]\n");
  36         fprintf(stderr, "          [ mode { ipip | gre | sit | isatap | vti } ] [ remote ADDR ] [ local ADDR ]\n");
  37         fprintf(stderr, "          [ [i|o]seq ] [ [i|o]key KEY ] [ [i|o]csum ]\n");
  38         fprintf(stderr, "          [ prl-default ADDR ] [ prl-nodefault ADDR ] [ prl-delete ADDR ]\n");
  39         fprintf(stderr, "          [ 6rd-prefix ADDR ] [ 6rd-relay_prefix ADDR ] [ 6rd-reset ]\n");
  40         fprintf(stderr, "          [ ttl TTL ] [ tos TOS ] [ [no]pmtudisc ] [ dev PHYS_DEV ]\n");
  41         fprintf(stderr, "\n");
  42         fprintf(stderr, "Where: NAME := STRING\n");
  43         fprintf(stderr, "       ADDR := { IP_ADDRESS | any }\n");
  44         fprintf(stderr, "       TOS  := { STRING | 00..ff | inherit | inherit/STRING | inherit/00..ff }\n");
  45         fprintf(stderr, "       TTL  := { 1..255 | inherit }\n");
  46         fprintf(stderr, "       KEY  := { DOTTED_QUAD | NUMBER }\n");
  47         exit(-1);
  48 }
  49
  50 static void set_tunnel_proto(struct ip_tunnel_parm *p, int proto)
  51 {
  52         if (p->iph.protocol && p->iph.protocol != proto) {
  53                 fprintf(stderr,"You managed to ask for more than one tunnel mode.\n");
  54                 exit(-1);
  55         }
  56         p->iph.protocol = proto;
  57 }
  58
  59 static int parse_args(int argc, char **argv, int cmd, struct ip_tunnel_parm *p)
  60 {
  61         int count = 0;
  62         char medium[IFNAMSIZ];
  63         int isatap = 0;
  64
  65         memset(p, 0, sizeof(*p));
  66         memset(&medium, 0, sizeof(medium));
  67
  68         p->iph.version = 4;
  69         p->iph.ihl = 5;
  70 #ifndef IP_DF
  71 #define IP_DF           0x4000          /* Flag: "Don't Fragment"       */
  72 #endif
  73         p->iph.frag_off = htons(IP_DF);
  74
  75         while (argc > 0) {
  76                 if (strcmp(*argv, "mode") == 0) {
  77                         NEXT_ARG();
  78                         if (strcmp(*argv, "ipip") == 0 ||
  79                             strcmp(*argv, "ip/ip") == 0) {
  80                                 set_tunnel_proto(p, IPPROTO_IPIP);
  81                         } else if (strcmp(*argv, "gre") == 0 ||
  82                                    strcmp(*argv, "gre/ip") == 0) {
  83                                 set_tunnel_proto(p, IPPROTO_GRE);
  84                         } else if (strcmp(*argv, "sit") == 0 ||
  85                                    strcmp(*argv, "ipv6/ip") == 0) {
  86                                 set_tunnel_proto(p, IPPROTO_IPV6);
  87                         } else if (strcmp(*argv, "isatap") == 0) {
  88                                 set_tunnel_proto(p, IPPROTO_IPV6);
  89                                 isatap++;
  90                         } else if (strcmp(*argv, "vti") == 0) {
  91                                 set_tunnel_proto(p, IPPROTO_IPIP);
  92                                 p->i_flags |= VTI_ISVTI;
  93                         } else {
  94                                 fprintf(stderr,"Unknown tunnel mode \"%s\"\n", *argv);
  95                                 exit(-1);
  96                         }
  97                 } else if (strcmp(*argv, "key") == 0) {
  98                         NEXT_ARG();
  99                         p->i_flags |= GRE_KEY;
 100                         p->o_flags |= GRE_KEY;
 101                         p->i_key = p->o_key = tnl_parse_key("key", *argv);
 102                 } else if (strcmp(*argv, "ikey") == 0) {
 103                         NEXT_ARG();
 104                         p->i_flags |= GRE_KEY;
 105                         p->i_key = tnl_parse_key("ikey", *argv);
 106                 } else if (strcmp(*argv, "okey") == 0) {
 107                         NEXT_ARG();
 108                         p->o_flags |= GRE_KEY;
 109                         p->o_key = tnl_parse_key("okey", *argv);
 110                 } else if (strcmp(*argv, "seq") == 0) {
 111                         p->i_flags |= GRE_SEQ;
 112                         p->o_flags |= GRE_SEQ;
 113                 } else if (strcmp(*argv, "iseq") == 0) {
 114                         p->i_flags |= GRE_SEQ;
 115                 } else if (strcmp(*argv, "oseq") == 0) {
 116                         p->o_flags |= GRE_SEQ;
 117                 } else if (strcmp(*argv, "csum") == 0) {
 118                         p->i_flags |= GRE_CSUM;
 119                         p->o_flags |= GRE_CSUM;
 120                 } else if (strcmp(*argv, "icsum") == 0) {
 121                         p->i_flags |= GRE_CSUM;
 122                 } else if (strcmp(*argv, "ocsum") == 0) {
 123                         p->o_flags |= GRE_CSUM;
 124                 } else if (strcmp(*argv, "nopmtudisc") == 0) {
 125                         p->iph.frag_off = 0;
 126                 } else if (strcmp(*argv, "pmtudisc") == 0) {
 127                         p->iph.frag_off = htons(IP_DF);
 128                 } else if (strcmp(*argv, "remote") == 0) {
 129                         NEXT_ARG();
 130                         if (strcmp(*argv, "any"))
 131                                 p->iph.daddr = get_addr32(*argv);
 132                         else
 133                                 p->iph.daddr = htonl(INADDR_ANY);
 134                 } else if (strcmp(*argv, "local") == 0) {
 135                         NEXT_ARG();
 136                         if (strcmp(*argv, "any"))
 137                                 p->iph.saddr = get_addr32(*argv);
 138                         else
 139                                 p->iph.saddr = htonl(INADDR_ANY);
 140                 } else if (strcmp(*argv, "dev") == 0) {
 141                         NEXT_ARG();
 142                         strncpy(medium, *argv, IFNAMSIZ - 1);
 143                 } else if (strcmp(*argv, "ttl") == 0 ||
 144                            strcmp(*argv, "hoplimit") == 0 ||
 145                            strcmp(*argv, "hlim") == 0) {
 146                         __u8 uval;
 147                         NEXT_ARG();
 148                         if (strcmp(*argv, "inherit") != 0) {
 149                                 if (get_u8(&uval, *argv, 0))
 150                                         invarg("invalid TTL\n", *argv);
 151                                 p->iph.ttl = uval;
 152                         }
 153                 } else if (strcmp(*argv, "tos") == 0 ||
 154                            strcmp(*argv, "tclass") == 0 ||
 155                            matches(*argv, "dsfield") == 0) {
 156                         char *dsfield;
 157                         __u32 uval;
 158                         NEXT_ARG();
 159                         dsfield = *argv;
 160                         strsep(&dsfield, "/");
 161                         if (strcmp(*argv, "inherit") != 0) {
 162                                 dsfield = *argv;
 163                                 p->iph.tos = 0;
 164                         } else
 165                                 p->iph.tos = 1;
 166                         if (dsfield) {
 167                                 if (rtnl_dsfield_a2n(&uval, dsfield))
 168                                         invarg("bad TOS value", *argv);
 169                                 p->iph.tos |= uval;
 170                         }
 171                 } else {
 172                         if (strcmp(*argv, "name") == 0) {
 173                                 NEXT_ARG();
 174                         } else if (matches(*argv, "help") == 0)
 175                                 usage();
 176                         if (p->name[0])
 177                                 duparg2("name", *argv);
 178                         strncpy(p->name, *argv, IFNAMSIZ - 1);
 179                         if (cmd == SIOCCHGTUNNEL && count == 0) {
 180                                 struct ip_tunnel_parm old_p;
 181                                 memset(&old_p, 0, sizeof(old_p));
 182                                 if (tnl_get_ioctl(*argv, &old_p))
 183                                         return -1;
 184                                 *p = old_p;
 185                         }
 186                 }
 187                 count++;
 188                 argc--; argv++;
 189         }
 190
 191
 192         if (p->iph.protocol == 0) {
 193                 if (memcmp(p->name, "gre", 3) == 0)
 194                         p->iph.protocol = IPPROTO_GRE;
 195                 else if (memcmp(p->name, "ipip", 4) == 0)
 196                         p->iph.protocol = IPPROTO_IPIP;
 197                 else if (memcmp(p->name, "sit", 3) == 0)
 198                         p->iph.protocol = IPPROTO_IPV6;
 199                 else if (memcmp(p->name, "isatap", 6) == 0) {
 200                         p->iph.protocol = IPPROTO_IPV6;
 201                         isatap++;
 202                 } else if (memcmp(p->name, "vti", 3) == 0) {
 203                         p->iph.protocol = IPPROTO_IPIP;
 204                         p->i_flags |= VTI_ISVTI;
 205                 }
 206         }
 207
 208         if ((p->i_flags & GRE_KEY) || (p->o_flags & GRE_KEY)) {
 209                 if (!(p->i_flags & VTI_ISVTI) &&
 210                     (p->iph.protocol != IPPROTO_GRE)) {
 211                         fprintf(stderr, "Keys are not allowed with ipip and sit tunnels\n");
 212                         return -1;
 213                 }
 214         }
 215
 216         if (medium[0]) {
 217                 p->link = ll_name_to_index(medium);
 218                 if (p->link == 0) {
 219                         fprintf(stderr, "Cannot find device \"%s\"\n", medium);
 220                         return -1;
 221                 }
 222         }
 223
 224         if (p->i_key == 0 && IN_MULTICAST(ntohl(p->iph.daddr))) {
 225                 p->i_key = p->iph.daddr;
 226                 p->i_flags |= GRE_KEY;
 227         }
 228         if (p->o_key == 0 && IN_MULTICAST(ntohl(p->iph.daddr))) {
 229                 p->o_key = p->iph.daddr;
 230                 p->o_flags |= GRE_KEY;
 231         }
 232         if (IN_MULTICAST(ntohl(p->iph.daddr)) && !p->iph.saddr) {
 233                 fprintf(stderr, "A broadcast tunnel requires a source address\n");
 234                 return -1;
 235         }
 236         if (isatap)
 237                 p->i_flags |= SIT_ISATAP;
 238
 239         return 0;
 240 }
 241
 242 static const char *tnl_defname(const struct ip_tunnel_parm *p)
 243 {
 244         switch (p->iph.protocol) {
 245         case IPPROTO_IPIP:
 246                 if (p->i_flags & VTI_ISVTI)
 247                         return "ip_vti0";
 248                 else
 249                         return "tunl0";
 250         case IPPROTO_GRE:
 251                 return "gre0";
 252         case IPPROTO_IPV6:
 253                 return "sit0";
 254         }
 255         return NULL;
 256 }
 257
 258 static int do_add(int cmd, int argc, char **argv)
 259 {
 260         struct ip_tunnel_parm p;
 261         const char *basedev;
 262
 263         if (parse_args(argc, argv, cmd, &p) < 0)
 264                 return -1;
 265
 266         if (p.iph.ttl && p.iph.frag_off == 0) {
 267                 fprintf(stderr, "ttl != 0 and nopmtudisc are incompatible\n");
 268                 return -1;
 269         }
 270
 271         if (!(basedev = tnl_defname(&p))) {
 272                 fprintf(stderr, "cannot determine tunnel mode (ipip, gre, vti or sit)\n");
 273                 return -1;
 274         }
 275
 276         return tnl_add_ioctl(cmd, basedev, p.name, &p);
 277 }
 278
 279 static int do_del(int argc, char **argv)
 280 {
 281         struct ip_tunnel_parm p;
 282
 283         if (parse_args(argc, argv, SIOCDELTUNNEL, &p) < 0)
 284                 return -1;
 285
 286         return tnl_del_ioctl(tnl_defname(&p) ? : p.name, p.name, &p);
 287 }
 288
 289 static void print_tunnel(struct ip_tunnel_parm *p)
 290 {
 291         struct ip_tunnel_6rd ip6rd;
 292         char s1[1024];
 293         char s2[1024];
 294
 295         memset(&ip6rd, 0, sizeof(ip6rd));
 296
 297         /* Do not use format_host() for local addr,
 298          * symbolic name will not be useful.
 299          */
 300         printf("%s: %s/ip remote %s local %s",
 301                p->name,
 302                tnl_strproto(p->iph.protocol),
 303                p->iph.daddr ? format_host(AF_INET, 4, &p->iph.daddr, s1, sizeof(s1)) : "any",
 304                p->iph.saddr ? rt_addr_n2a(AF_INET, 4, &p->iph.saddr, s2, sizeof(s2)) : "any");
 305
 306         if (p->iph.protocol == IPPROTO_IPV6 && (p->i_flags & SIT_ISATAP)) {
 307                 struct ip_tunnel_prl prl[16];
 308                 int i;
 309
 310                 memset(prl, 0, sizeof(prl));
 311                 prl[0].datalen = sizeof(prl) - sizeof(prl[0]);
 312                 prl[0].addr = htonl(INADDR_ANY);
 313
 314                 if (!tnl_prl_ioctl(SIOCGETPRL, p->name, prl))
 315                         for (i = 1; i < sizeof(prl) / sizeof(prl[0]); i++)
 316                 {
 317                         if (prl[i].addr != htonl(INADDR_ANY)) {
 318                                 printf(" %s %s ",
 319                                         (prl[i].flags & PRL_DEFAULT) ? "pdr" : "pr",
 320                                         format_host(AF_INET, 4, &prl[i].addr, s1, sizeof(s1)));
 321                         }
 322                 }
 323         }
 324
 325         if (p->link) {
 326                 const char *n = ll_index_to_name(p->link);
 327                 if (n)
 328                         printf(" dev %s", n);
 329         }
 330
 331         if (p->iph.ttl)
 332                 printf(" ttl %d", p->iph.ttl);
 333         else
 334                 printf(" ttl inherit");
 335
 336         if (p->iph.tos) {
 337                 SPRINT_BUF(b1);
 338                 printf(" tos");
 339                 if (p->iph.tos & 1)
 340                         printf(" inherit");
 341                 if (p->iph.tos & ~1)
 342                         printf("%c%s ", p->iph.tos & 1 ? '/' : ' ',
 343                                rtnl_dsfield_n2a(p->iph.tos & ~1, b1, sizeof(b1)));
 344         }
 345
 346         if (!(p->iph.frag_off & htons(IP_DF)))
 347                 printf(" nopmtudisc");
 348
 349         if (p->iph.protocol == IPPROTO_IPV6 && !tnl_ioctl_get_6rd(p->name, &ip6rd) && ip6rd.prefixlen) {
 350                 printf(" 6rd-prefix %s/%u",
 351                        inet_ntop(AF_INET6, &ip6rd.prefix, s1, sizeof(s1)),
 352                        ip6rd.prefixlen);
 353                 if (ip6rd.relay_prefix) {
 354                         printf(" 6rd-relay_prefix %s/%u",
 355                                format_host(AF_INET, 4, &ip6rd.relay_prefix, s1, sizeof(s1)),
 356                                ip6rd.relay_prefixlen);
 357                 }
 358         }
 359
 360         if ((p->i_flags & GRE_KEY) && (p->o_flags & GRE_KEY) && p->o_key == p->i_key)
 361                 printf(" key %u", ntohl(p->i_key));
 362         else if ((p->i_flags | p->o_flags) & GRE_KEY) {
 363                 if (p->i_flags & GRE_KEY)
 364                         printf(" ikey %u", ntohl(p->i_key));
 365                 if (p->o_flags & GRE_KEY)
 366                         printf(" okey %u", ntohl(p->o_key));
 367         }
 368
 369         if (p->i_flags & GRE_SEQ)
 370                 printf("%s  Drop packets out of sequence.", _SL_);
 371         if (p->i_flags & GRE_CSUM)
 372                 printf("%s  Checksum in received packet is required.", _SL_);
 373         if (p->o_flags & GRE_SEQ)
 374                 printf("%s  Sequence packets on output.", _SL_);
 375         if (p->o_flags & GRE_CSUM)
 376                 printf("%s  Checksum output packets.", _SL_);
 377 }
 378
 379 static int do_tunnels_list(struct ip_tunnel_parm *p)
 380 {
 381         char buf[512];
 382         int err = -1;
 383         FILE *fp = fopen("/proc/net/dev", "r");
 384         if (fp == NULL) {
 385                 perror("fopen");
 386                 return -1;
 387         }
 388
 389         /* skip header lines */
 390         if (!fgets(buf, sizeof(buf), fp) ||
 391             !fgets(buf, sizeof(buf), fp)) {
 392                 fprintf(stderr, "/proc/net/dev read error\n");
 393                 goto end;
 394         }
 395
 396         while (fgets(buf, sizeof(buf), fp) != NULL) {
 397                 char name[IFNAMSIZ];
 398                 int index, type;
 399                 unsigned long rx_bytes, rx_packets, rx_errs, rx_drops,
 400                         rx_fifo, rx_frame,
 401                         tx_bytes, tx_packets, tx_errs, tx_drops,
 402                         tx_fifo, tx_colls, tx_carrier, rx_multi;
 403                 struct ip_tunnel_parm p1;
 404                 char *ptr;
 405
 406                 buf[sizeof(buf) - 1] = 0;
 407                 if ((ptr = strchr(buf, ':')) == NULL ||
 408                     (*ptr++ = 0, sscanf(buf, "%s", name) != 1)) {
 409                         fprintf(stderr, "Wrong format for /proc/net/dev. Giving up.\n");
 410                         goto end;
 411                 }
 412                 if (sscanf(ptr, "%ld%ld%ld%ld%ld%ld%ld%*d%ld%ld%ld%ld%ld%ld%ld",
 413                            &rx_bytes, &rx_packets, &rx_errs, &rx_drops,
 414                            &rx_fifo, &rx_frame, &rx_multi,
 415                            &tx_bytes, &tx_packets, &tx_errs, &tx_drops,
 416                            &tx_fifo, &tx_colls, &tx_carrier) != 14)
 417                         continue;
 418                 if (p->name[0] && strcmp(p->name, name))
 419                         continue;
 420                 index = ll_name_to_index(name);
 421                 if (index == 0)
 422                         continue;
 423                 type = ll_index_to_type(index);
 424                 if (type == -1) {
 425                         fprintf(stderr, "Failed to get type of \"%s\"\n", name);
 426                         continue;
 427                 }
 428                 if (type != ARPHRD_TUNNEL && type != ARPHRD_IPGRE && type != ARPHRD_SIT)
 429                         continue;
 430                 memset(&p1, 0, sizeof(p1));
 431                 if (tnl_get_ioctl(name, &p1))
 432                         continue;
 433                 if ((p->link && p1.link != p->link) ||
 434                     (p->name[0] && strcmp(p1.name, p->name)) ||
 435                     (p->iph.daddr && p1.iph.daddr != p->iph.daddr) ||
 436                     (p->iph.saddr && p1.iph.saddr != p->iph.saddr) ||
 437                     (p->i_key && p1.i_key != p->i_key))
 438                         continue;
 439                 print_tunnel(&p1);
 440                 if (show_stats) {
 441                         printf("%s", _SL_);
 442                         printf("RX: Packets    Bytes        Errors CsumErrs OutOfSeq Mcasts%s", _SL_);
 443                         printf("    %-10ld %-12ld %-6ld %-8ld %-8ld %-8ld%s",
 444                                rx_packets, rx_bytes, rx_errs, rx_frame, rx_fifo, rx_multi, _SL_);
 445                         printf("TX: Packets    Bytes        Errors DeadLoop NoRoute  NoBufs%s", _SL_);
 446                         printf("    %-10ld %-12ld %-6ld %-8ld %-8ld %-6ld",
 447                                tx_packets, tx_bytes, tx_errs, tx_colls, tx_carrier, tx_drops);
 448                 }
 449                 printf("\n");
 450         }
 451         err = 0;
 452  end:
 453         fclose(fp);
 454         return err;
 455 }
 456
 457 static int do_show(int argc, char **argv)
 458 {
 459         struct ip_tunnel_parm p;
 460         const char *basedev;
 461
 462         ll_init_map(&rth);
 463         if (parse_args(argc, argv, SIOCGETTUNNEL, &p) < 0)
 464                 return -1;
 465
 466         if (!(basedev = tnl_defname(&p)))
 467                 return do_tunnels_list(&p);
 468
 469         if (tnl_get_ioctl(p.name[0] ? p.name : basedev, &p))
 470                 return -1;
 471
 472         print_tunnel(&p);
 473         printf("\n");
 474         return 0;
 475 }
 476
 477 static int do_prl(int argc, char **argv)
 478 {
 479         struct ip_tunnel_prl p;
 480         int count = 0;
 481         int devname = 0;
 482         int cmd = 0;
 483         char medium[IFNAMSIZ];
 484
 485         memset(&p, 0, sizeof(p));
 486         memset(&medium, 0, sizeof(medium));
 487
 488         while (argc > 0) {
 489                 if (strcmp(*argv, "prl-default") == 0) {
 490                         NEXT_ARG();
 491                         cmd = SIOCADDPRL;
 492                         p.addr = get_addr32(*argv);
 493                         p.flags |= PRL_DEFAULT;
 494                         count++;
 495                 } else if (strcmp(*argv, "prl-nodefault") == 0) {
 496                         NEXT_ARG();
 497                         cmd = SIOCADDPRL;
 498                         p.addr = get_addr32(*argv);
 499                         count++;
 500                 } else if (strcmp(*argv, "prl-delete") == 0) {
 501                         NEXT_ARG();
 502                         cmd = SIOCDELPRL;
 503                         p.addr = get_addr32(*argv);
 504                         count++;
 505                 } else if (strcmp(*argv, "dev") == 0) {
 506                         NEXT_ARG();
 507                         strncpy(medium, *argv, IFNAMSIZ-1);
 508                         devname++;
 509                 } else {
 510                         fprintf(stderr,"Invalid PRL parameter \"%s\"\n", *argv);
 511                         exit(-1);
 512                 }
 513                 if (count > 1) {
 514                         fprintf(stderr,"One PRL entry at a time\n");
 515                         exit(-1);
 516                 }
 517                 argc--; argv++;
 518         }
 519         if (devname == 0) {
 520                 fprintf(stderr, "Must specify device\n");
 521                 exit(-1);
 522         }
 523
 524         return tnl_prl_ioctl(cmd, medium, &p);
 525 }
 526
 527 static int do_6rd(int argc, char **argv)
 528 {
 529         struct ip_tunnel_6rd ip6rd;
 530         int devname = 0;
 531         int cmd = 0;
 532         char medium[IFNAMSIZ];
 533         inet_prefix prefix;
 534
 535         memset(&ip6rd, 0, sizeof(ip6rd));
 536         memset(&medium, 0, sizeof(medium));
 537
 538         while (argc > 0) {
 539                 if (strcmp(*argv, "6rd-prefix") == 0) {
 540                         NEXT_ARG();
 541                         if (get_prefix(&prefix, *argv, AF_INET6))
 542                                 invarg("invalid 6rd_prefix\n", *argv);
 543                         cmd = SIOCADD6RD;
 544                         memcpy(&ip6rd.prefix, prefix.data, 16);
 545                         ip6rd.prefixlen = prefix.bitlen;
 546                 } else if (strcmp(*argv, "6rd-relay_prefix") == 0) {
 547                         NEXT_ARG();
 548                         if (get_prefix(&prefix, *argv, AF_INET))
 549                                 invarg("invalid 6rd-relay_prefix\n", *argv);
 550                         cmd = SIOCADD6RD;
 551                         memcpy(&ip6rd.relay_prefix, prefix.data, 4);
 552                         ip6rd.relay_prefixlen = prefix.bitlen;
 553                 } else if (strcmp(*argv, "6rd-reset") == 0) {
 554                         cmd = SIOCDEL6RD;
 555                 } else if (strcmp(*argv, "dev") == 0) {
 556                         NEXT_ARG();
 557                         strncpy(medium, *argv, IFNAMSIZ-1);
 558                         devname++;
 559                 } else {
 560                         fprintf(stderr,"Invalid 6RD parameter \"%s\"\n", *argv);
 561                         exit(-1);
 562                 }
 563                 argc--; argv++;
 564         }
 565         if (devname == 0) {
 566                 fprintf(stderr, "Must specify device\n");
 567                 exit(-1);
 568         }
 569
 570         return tnl_6rd_ioctl(cmd, medium, &ip6rd);
 571 }
 572
 573 int do_iptunnel(int argc, char **argv)
 574 {
 575         switch (preferred_family) {
 576         case AF_UNSPEC:
 577                 preferred_family = AF_INET;
 578                 break;
 579         case AF_INET:
 580                 break;
 581         /*
 582          * This is silly enough but we have no easy way to make it
 583          * protocol-independent because of unarranged structure between
 584          * IPv4 and IPv6.
 585          */
 586         case AF_INET6:
 587                 return do_ip6tunnel(argc, argv);
 588         default:
 589                 fprintf(stderr, "Unsupported protocol family: %d\n", preferred_family);
 590                 exit(-1);
 591         }
 592
 593         if (argc > 0) {
 594                 if (matches(*argv, "add") == 0)
 595                         return do_add(SIOCADDTUNNEL, argc - 1, argv + 1);
 596                 if (matches(*argv, "change") == 0)
 597                         return do_add(SIOCCHGTUNNEL, argc - 1, argv + 1);
 598                 if (matches(*argv, "delete") == 0)
 599                         return do_del(argc - 1, argv + 1);
 600                 if (matches(*argv, "show") == 0 ||
 601                     matches(*argv, "lst") == 0 ||
 602                     matches(*argv, "list") == 0)
 603                         return do_show(argc - 1, argv + 1);
 604                 if (matches(*argv, "prl") == 0)
 605                         return do_prl(argc - 1, argv + 1);
 606                 if (matches(*argv, "6rd") == 0)
 607                         return do_6rd(argc - 1, argv + 1);
 608                 if (matches(*argv, "help") == 0)
 609                         usage();
 610         } else
 611                 return do_show(0, NULL);
 612
 613         fprintf(stderr, "Command \"%s\" is unknown, try \"ip tunnel help\"\n", *argv);
 614         exit(-1);
 615 }