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,
  36                 "Usage: ip tunnel { add | change | del | show | prl | 6rd } [ NAME ]\n"
  37                 "        [ mode { ipip | gre | sit | isatap | vti } ] [ remote ADDR ] [ local ADDR ]\n"
  38                 "        [ [i|o]seq ] [ [i|o]key KEY ] [ [i|o]csum ]\n"
  39                 "        [ prl-default ADDR ] [ prl-nodefault ADDR ] [ prl-delete ADDR ]\n"
  40                 "        [ 6rd-prefix ADDR ] [ 6rd-relay_prefix ADDR ] [ 6rd-reset ]\n"
  41                 "        [ ttl TTL ] [ tos TOS ] [ [no]pmtudisc ] [ dev PHYS_DEV ]\n"
  42                 "\n"
  43                 "Where: NAME := STRING\n"
  44                 "       ADDR := { IP_ADDRESS | any }\n"
  45                 "       TOS  := { STRING | 00..ff | inherit | inherit/STRING | inherit/00..ff }\n"
  46                 "       TTL  := { 1..255 | inherit }\n"
  47                 "       KEY  := { DOTTED_QUAD | NUMBER }\n");
  48         exit(-1);
  49 }
  50
  51 static void set_tunnel_proto(struct ip_tunnel_parm *p, int proto)
  52 {
  53         if (p->iph.protocol && p->iph.protocol != proto) {
  54                 fprintf(stderr,
  55                         "You managed to ask for more than one tunnel mode.\n");
  56                 exit(-1);
  57         }
  58         p->iph.protocol = proto;
  59 }
  60
  61 static int parse_args(int argc, char **argv, int cmd, struct ip_tunnel_parm *p)
  62 {
  63         int count = 0;
  64         const char *medium = NULL;
  65         int isatap = 0;
  66
  67         memset(p, 0, sizeof(*p));
  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,
  95                                         "Unknown tunnel mode \"%s\"\n", *argv);
  96                                 exit(-1);
  97                         }
  98                 } else if (strcmp(*argv, "key") == 0) {
  99                         NEXT_ARG();
 100                         p->i_flags |= GRE_KEY;
 101                         p->o_flags |= GRE_KEY;
 102                         p->i_key = p->o_key = tnl_parse_key("key", *argv);
 103                 } else if (strcmp(*argv, "ikey") == 0) {
 104                         NEXT_ARG();
 105                         p->i_flags |= GRE_KEY;
 106                         p->i_key = tnl_parse_key("ikey", *argv);
 107                 } else if (strcmp(*argv, "okey") == 0) {
 108                         NEXT_ARG();
 109                         p->o_flags |= GRE_KEY;
 110                         p->o_key = tnl_parse_key("okey", *argv);
 111                 } else if (strcmp(*argv, "seq") == 0) {
 112                         p->i_flags |= GRE_SEQ;
 113                         p->o_flags |= GRE_SEQ;
 114                 } else if (strcmp(*argv, "iseq") == 0) {
 115                         p->i_flags |= GRE_SEQ;
 116                 } else if (strcmp(*argv, "oseq") == 0) {
 117                         p->o_flags |= GRE_SEQ;
 118                 } else if (strcmp(*argv, "csum") == 0) {
 119                         p->i_flags |= GRE_CSUM;
 120                         p->o_flags |= GRE_CSUM;
 121                 } else if (strcmp(*argv, "icsum") == 0) {
 122                         p->i_flags |= GRE_CSUM;
 123                 } else if (strcmp(*argv, "ocsum") == 0) {
 124                         p->o_flags |= GRE_CSUM;
 125                 } else if (strcmp(*argv, "nopmtudisc") == 0) {
 126                         p->iph.frag_off = 0;
 127                 } else if (strcmp(*argv, "pmtudisc") == 0) {
 128                         p->iph.frag_off = htons(IP_DF);
 129                 } else if (strcmp(*argv, "remote") == 0) {
 130                         NEXT_ARG();
 131                         p->iph.daddr = get_addr32(*argv);
 132                 } else if (strcmp(*argv, "local") == 0) {
 133                         NEXT_ARG();
 134                         p->iph.saddr = get_addr32(*argv);
 135                 } else if (strcmp(*argv, "dev") == 0) {
 136                         NEXT_ARG();
 137                         medium = *argv;
 138                 } else if (strcmp(*argv, "ttl") == 0 ||
 139                            strcmp(*argv, "hoplimit") == 0 ||
 140                            strcmp(*argv, "hlim") == 0) {
 141                         __u8 uval;
 142
 143                         NEXT_ARG();
 144                         if (strcmp(*argv, "inherit") != 0) {
 145                                 if (get_u8(&uval, *argv, 0))
 146                                         invarg("invalid TTL\n", *argv);
 147                                 p->iph.ttl = uval;
 148                         }
 149                 } else if (strcmp(*argv, "tos") == 0 ||
 150                            strcmp(*argv, "tclass") == 0 ||
 151                            matches(*argv, "dsfield") == 0) {
 152                         char *dsfield;
 153                         __u32 uval;
 154
 155                         NEXT_ARG();
 156                         dsfield = *argv;
 157                         strsep(&dsfield, "/");
 158                         if (strcmp(*argv, "inherit") != 0) {
 159                                 dsfield = *argv;
 160                                 p->iph.tos = 0;
 161                         } else
 162                                 p->iph.tos = 1;
 163                         if (dsfield) {
 164                                 if (rtnl_dsfield_a2n(&uval, dsfield))
 165                                         invarg("bad TOS value", *argv);
 166                                 p->iph.tos |= uval;
 167                         }
 168                 } else {
 169                         if (strcmp(*argv, "name") == 0)
 170                                 NEXT_ARG();
 171                         else if (matches(*argv, "help") == 0)
 172                                 usage();
 173
 174                         if (p->name[0])
 175                                 duparg2("name", *argv);
 176                         if (get_ifname(p->name, *argv))
 177                                 invarg("\"name\" not a valid ifname", *argv);
 178                         if (cmd == SIOCCHGTUNNEL && count == 0) {
 179                                 struct ip_tunnel_parm old_p = {};
 180
 181                                 if (tnl_get_ioctl(*argv, &old_p))
 182                                         return -1;
 183                                 *p = old_p;
 184                         }
 185                 }
 186                 count++;
 187                 argc--; argv++;
 188         }
 189
 190
 191         if (p->iph.protocol == 0) {
 192                 if (memcmp(p->name, "gre", 3) == 0)
 193                         p->iph.protocol = IPPROTO_GRE;
 194                 else if (memcmp(p->name, "ipip", 4) == 0)
 195                         p->iph.protocol = IPPROTO_IPIP;
 196                 else if (memcmp(p->name, "sit", 3) == 0)
 197                         p->iph.protocol = IPPROTO_IPV6;
 198                 else if (memcmp(p->name, "isatap", 6) == 0) {
 199                         p->iph.protocol = IPPROTO_IPV6;
 200                         isatap++;
 201                 } else if (memcmp(p->name, "vti", 3) == 0) {
 202                         p->iph.protocol = IPPROTO_IPIP;
 203                         p->i_flags |= VTI_ISVTI;
 204                 }
 205         }
 206
 207         if ((p->i_flags & GRE_KEY) || (p->o_flags & GRE_KEY)) {
 208                 if (!(p->i_flags & VTI_ISVTI) &&
 209                     (p->iph.protocol != IPPROTO_GRE)) {
 210                         fprintf(stderr, "Keys are not allowed with ipip and sit tunnels\n");
 211                         return -1;
 212                 }
 213         }
 214
 215         if (medium) {
 216                 p->link = ll_name_to_index(medium);
 217                 if (!p->link)
 218                         return nodev(medium);
 219         }
 220
 221         if (p->i_key == 0 && IN_MULTICAST(ntohl(p->iph.daddr))) {
 222                 p->i_key = p->iph.daddr;
 223                 p->i_flags |= GRE_KEY;
 224         }
 225         if (p->o_key == 0 && IN_MULTICAST(ntohl(p->iph.daddr))) {
 226                 p->o_key = p->iph.daddr;
 227                 p->o_flags |= GRE_KEY;
 228         }
 229         if (IN_MULTICAST(ntohl(p->iph.daddr)) && !p->iph.saddr) {
 230                 fprintf(stderr, "A broadcast tunnel requires a source address\n");
 231                 return -1;
 232         }
 233         if (isatap)
 234                 p->i_flags |= SIT_ISATAP;
 235
 236         return 0;
 237 }
 238
 239 static const char *tnl_defname(const struct ip_tunnel_parm *p)
 240 {
 241         switch (p->iph.protocol) {
 242         case IPPROTO_IPIP:
 243                 if (p->i_flags & VTI_ISVTI)
 244                         return "ip_vti0";
 245                 else
 246                         return "tunl0";
 247         case IPPROTO_GRE:
 248                 return "gre0";
 249         case IPPROTO_IPV6:
 250                 return "sit0";
 251         }
 252         return NULL;
 253 }
 254
 255 static int do_add(int cmd, int argc, char **argv)
 256 {
 257         struct ip_tunnel_parm p;
 258         const char *basedev;
 259
 260         if (parse_args(argc, argv, cmd, &p) < 0)
 261                 return -1;
 262
 263         if (p.iph.ttl && p.iph.frag_off == 0) {
 264                 fprintf(stderr, "ttl != 0 and nopmtudisc are incompatible\n");
 265                 return -1;
 266         }
 267
 268         basedev = tnl_defname(&p);
 269         if (!basedev) {
 270                 fprintf(stderr,
 271                         "cannot determine tunnel mode (ipip, gre, vti or sit)\n");
 272                 return -1;
 273         }
 274
 275         return tnl_add_ioctl(cmd, basedev, p.name, &p);
 276 }
 277
 278 static int do_del(int argc, char **argv)
 279 {
 280         struct ip_tunnel_parm p;
 281
 282         if (parse_args(argc, argv, SIOCDELTUNNEL, &p) < 0)
 283                 return -1;
 284
 285         return tnl_del_ioctl(tnl_defname(&p) ? : p.name, p.name, &p);
 286 }
 287
 288 static void print_tunnel(const void *t)
 289 {
 290         const struct ip_tunnel_parm *p = t;
 291         struct ip_tunnel_6rd ip6rd = {};
 292         SPRINT_BUF(b1);
 293
 294         /* Do not use format_host() for local addr,
 295          * symbolic name will not be useful.
 296          */
 297         open_json_object(NULL);
 298         print_color_string(PRINT_ANY, COLOR_IFNAME, "ifname", "%s: ", p->name);
 299         snprintf(b1, sizeof(b1), "%s/ip", tnl_strproto(p->iph.protocol));
 300         print_string(PRINT_ANY, "mode", "%s ", b1);
 301         print_null(PRINT_FP, NULL, "remote ", NULL);
 302         print_color_string(PRINT_ANY, COLOR_INET, "remote", "%s ",
 303                            p->iph.daddr || is_json_context()
 304                                 ? format_host_r(AF_INET, 4, &p->iph.daddr, b1, sizeof(b1))
 305                                 : "any");
 306         print_null(PRINT_FP, NULL, "local ", NULL);
 307         print_color_string(PRINT_ANY, COLOR_INET, "local", "%s",
 308                            p->iph.saddr || is_json_context()
 309                                 ? rt_addr_n2a_r(AF_INET, 4, &p->iph.saddr, b1, sizeof(b1))
 310                                 : "any");
 311
 312         if (p->iph.protocol == IPPROTO_IPV6 && (p->i_flags & SIT_ISATAP)) {
 313                 struct ip_tunnel_prl prl[16] = {};
 314                 int i;
 315
 316                 prl[0].datalen = sizeof(prl) - sizeof(prl[0]);
 317                 prl[0].addr = htonl(INADDR_ANY);
 318
 319                 if (!tnl_prl_ioctl(SIOCGETPRL, p->name, prl)) {
 320                         for (i = 1; i < ARRAY_SIZE(prl); i++) {
 321                                 if (prl[i].addr == htonl(INADDR_ANY))
 322                                         continue;
 323                                 if (prl[i].flags & PRL_DEFAULT)
 324                                         print_string(PRINT_ANY, "pdr",
 325                                                      " pdr %s",
 326                                                      format_host(AF_INET, 4, &prl[i].addr));
 327                                 else
 328                                         print_string(PRINT_ANY, "pr", " pr %s",
 329                                                      format_host(AF_INET, 4, &prl[i].addr));
 330                         }
 331                 }
 332         }
 333
 334         if (p->link) {
 335                 const char *n = ll_index_to_name(p->link);
 336
 337                 if (n)
 338                         print_string(PRINT_ANY, "dev", " dev %s", n);
 339         }
 340
 341         if (p->iph.ttl)
 342                 print_uint(PRINT_ANY, "ttl", " ttl %u", p->iph.ttl);
 343         else
 344                 print_string(PRINT_FP, "ttl", " ttl %s", "inherit");
 345
 346         if (p->iph.tos) {
 347                 SPRINT_BUF(b2);
 348
 349                 if (p->iph.tos != 1) {
 350                         if (!is_json_context() && p->iph.tos & 1)
 351                                 snprintf(b2, sizeof(b2), "%s%s",
 352                                          p->iph.tos & 1 ? "inherit/" : "",
 353                                          rtnl_dsfield_n2a(p->iph.tos & ~1, b1, sizeof(b1)));
 354                         else
 355                                 snprintf(b2, sizeof(b2), "%s",
 356                                          rtnl_dsfield_n2a(p->iph.tos, b1, sizeof(b1)));
 357                         print_string(PRINT_ANY, "tos", " tos %s", b2);
 358                 } else {
 359                         print_string(PRINT_FP, NULL, " tos %s", "inherit");
 360                 }
 361         }
 362
 363         if (!(p->iph.frag_off & htons(IP_DF)))
 364                 print_null(PRINT_ANY, "nopmtudisc", " nopmtudisc", NULL);
 365
 366         if (p->iph.protocol == IPPROTO_IPV6 && !tnl_ioctl_get_6rd(p->name, &ip6rd) && ip6rd.prefixlen) {
 367                 print_string(PRINT_ANY, "6rd-prefix", " 6rd-prefix %s",
 368                              inet_ntop(AF_INET6, &ip6rd.prefix, b1, sizeof(b1)));
 369                 print_uint(PRINT_ANY, "6rd-prefixlen", "/%u", ip6rd.prefixlen);
 370                 if (ip6rd.relay_prefix) {
 371                         print_string(PRINT_ANY, "6rd-relay_prefix",
 372                                      " 6rd-relay_prefix %s",
 373                                      format_host(AF_INET, 4, &ip6rd.relay_prefix));
 374                         print_uint(PRINT_ANY, "6rd-relay_prefixlen", "/%u",
 375                                    ip6rd.relay_prefixlen);
 376                 }
 377         }
 378
 379         tnl_print_gre_flags(p->iph.protocol, p->i_flags, p->o_flags,
 380                             p->i_key, p->o_key);
 381
 382         close_json_object();
 383 }
 384
 385
 386 static void ip_tunnel_parm_initialize(const struct tnl_print_nlmsg_info *info)
 387 {
 388         struct ip_tunnel_parm *p2 = info->p2;
 389
 390         memset(p2, 0, sizeof(*p2));
 391 }
 392
 393 static bool ip_tunnel_parm_match(const struct tnl_print_nlmsg_info *info)
 394 {
 395         const struct ip_tunnel_parm *p1 = info->p1;
 396         const struct ip_tunnel_parm *p2 = info->p2;
 397
 398         return ((!p1->link || p1->link == p2->link) &&
 399                 (!p1->name[0] || strcmp(p1->name, p2->name) == 0) &&
 400                 (!p1->iph.daddr || p1->iph.daddr == p2->iph.daddr) &&
 401                 (!p1->iph.saddr || p1->iph.saddr == p2->iph.saddr) &&
 402                 (!p1->i_key || p1->i_key == p2->i_key));
 403 }
 404
 405 static int do_show(int argc, char **argv)
 406 {
 407         struct ip_tunnel_parm p, p1;
 408         const char *basedev;
 409
 410         if (parse_args(argc, argv, SIOCGETTUNNEL, &p) < 0)
 411                 return -1;
 412
 413         basedev = tnl_defname(&p);
 414         if (!basedev) {
 415                 struct tnl_print_nlmsg_info info = {
 416                         .p1    = &p,
 417                         .p2    = &p1,
 418                         .init  = ip_tunnel_parm_initialize,
 419                         .match = ip_tunnel_parm_match,
 420                         .print = print_tunnel,
 421                 };
 422
 423                 return do_tunnels_list(&info);
 424         }
 425
 426         if (tnl_get_ioctl(p.name[0] ? p.name : basedev, &p))
 427                 return -1;
 428
 429         print_tunnel(&p);
 430         fputc('\n', stdout);
 431         return 0;
 432 }
 433
 434 static int do_prl(int argc, char **argv)
 435 {
 436         struct ip_tunnel_prl p = {};
 437         int count = 0;
 438         int cmd = 0;
 439         const char *medium = NULL;
 440
 441         while (argc > 0) {
 442                 if (strcmp(*argv, "prl-default") == 0) {
 443                         NEXT_ARG();
 444                         cmd = SIOCADDPRL;
 445                         p.addr = get_addr32(*argv);
 446                         p.flags |= PRL_DEFAULT;
 447                         count++;
 448                 } else if (strcmp(*argv, "prl-nodefault") == 0) {
 449                         NEXT_ARG();
 450                         cmd = SIOCADDPRL;
 451                         p.addr = get_addr32(*argv);
 452                         count++;
 453                 } else if (strcmp(*argv, "prl-delete") == 0) {
 454                         NEXT_ARG();
 455                         cmd = SIOCDELPRL;
 456                         p.addr = get_addr32(*argv);
 457                         count++;
 458                 } else if (strcmp(*argv, "dev") == 0) {
 459                         NEXT_ARG();
 460                         if (check_ifname(*argv))
 461                                 invarg("\"dev\" not a valid ifname", *argv);
 462                         medium = *argv;
 463                 } else {
 464                         fprintf(stderr,
 465                                 "Invalid PRL parameter \"%s\"\n", *argv);
 466                         exit(-1);
 467                 }
 468                 if (count > 1) {
 469                         fprintf(stderr,
 470                                 "One PRL entry at a time\n");
 471                         exit(-1);
 472                 }
 473                 argc--; argv++;
 474         }
 475         if (!medium) {
 476                 fprintf(stderr, "Must specify device\n");
 477                 exit(-1);
 478         }
 479
 480         return tnl_prl_ioctl(cmd, medium, &p);
 481 }
 482
 483 static int do_6rd(int argc, char **argv)
 484 {
 485         struct ip_tunnel_6rd ip6rd = {};
 486         int cmd = 0;
 487         const char *medium = NULL;
 488         inet_prefix prefix;
 489
 490         while (argc > 0) {
 491                 if (strcmp(*argv, "6rd-prefix") == 0) {
 492                         NEXT_ARG();
 493                         if (get_prefix(&prefix, *argv, AF_INET6))
 494                                 invarg("invalid 6rd_prefix\n", *argv);
 495                         cmd = SIOCADD6RD;
 496                         memcpy(&ip6rd.prefix, prefix.data, 16);
 497                         ip6rd.prefixlen = prefix.bitlen;
 498                 } else if (strcmp(*argv, "6rd-relay_prefix") == 0) {
 499                         NEXT_ARG();
 500                         if (get_prefix(&prefix, *argv, AF_INET))
 501                                 invarg("invalid 6rd-relay_prefix\n", *argv);
 502                         cmd = SIOCADD6RD;
 503                         memcpy(&ip6rd.relay_prefix, prefix.data, 4);
 504                         ip6rd.relay_prefixlen = prefix.bitlen;
 505                 } else if (strcmp(*argv, "6rd-reset") == 0) {
 506                         cmd = SIOCDEL6RD;
 507                 } else if (strcmp(*argv, "dev") == 0) {
 508                         NEXT_ARG();
 509                         if (check_ifname(*argv))
 510                                 invarg("\"dev\" not a valid ifname", *argv);
 511                         medium = *argv;
 512                 } else {
 513                         fprintf(stderr,
 514                                 "Invalid 6RD parameter \"%s\"\n", *argv);
 515                         exit(-1);
 516                 }
 517                 argc--; argv++;
 518         }
 519         if (!medium) {
 520                 fprintf(stderr, "Must specify device\n");
 521                 exit(-1);
 522         }
 523
 524         return tnl_6rd_ioctl(cmd, medium, &ip6rd);
 525 }
 526
 527 static int tunnel_mode_is_ipv6(char *tunnel_mode)
 528 {
 529         static const char * const ipv6_modes[] = {
 530                 "ipv6/ipv6", "ip6ip6",
 531                 "vti6",
 532                 "ip/ipv6", "ipv4/ipv6", "ipip6", "ip4ip6",
 533                 "ip6gre", "gre/ipv6",
 534                 "any/ipv6", "any"
 535         };
 536         int i;
 537
 538         for (i = 0; i < ARRAY_SIZE(ipv6_modes); i++) {
 539                 if (strcmp(ipv6_modes[i], tunnel_mode) == 0)
 540                         return 1;
 541         }
 542         return 0;
 543 }
 544
 545 int do_iptunnel(int argc, char **argv)
 546 {
 547         int i;
 548
 549         for (i = 0; i < argc - 1; i++) {
 550                 if (strcmp(argv[i], "mode") == 0) {
 551                         if (tunnel_mode_is_ipv6(argv[i + 1]))
 552                                 preferred_family = AF_INET6;
 553                         break;
 554                 }
 555         }
 556         switch (preferred_family) {
 557         case AF_UNSPEC:
 558                 preferred_family = AF_INET;
 559                 break;
 560         case AF_INET:
 561                 break;
 562         /*
 563          * This is silly enough but we have no easy way to make it
 564          * protocol-independent because of unarranged structure between
 565          * IPv4 and IPv6.
 566          */
 567         case AF_INET6:
 568                 return do_ip6tunnel(argc, argv);
 569         default:
 570                 fprintf(stderr, "Unsupported protocol family: %d\n", preferred_family);
 571                 exit(-1);
 572         }
 573
 574         if (argc > 0) {
 575                 if (matches(*argv, "add") == 0)
 576                         return do_add(SIOCADDTUNNEL, argc - 1, argv + 1);
 577                 if (matches(*argv, "change") == 0)
 578                         return do_add(SIOCCHGTUNNEL, argc - 1, argv + 1);
 579                 if (matches(*argv, "delete") == 0)
 580                         return do_del(argc - 1, argv + 1);
 581                 if (matches(*argv, "show") == 0 ||
 582                     matches(*argv, "lst") == 0 ||
 583                     matches(*argv, "list") == 0)
 584                         return do_show(argc - 1, argv + 1);
 585                 if (matches(*argv, "prl") == 0)
 586                         return do_prl(argc - 1, argv + 1);
 587                 if (matches(*argv, "6rd") == 0)
 588                         return do_6rd(argc - 1, argv + 1);
 589                 if (matches(*argv, "help") == 0)
 590                         usage();
 591         } else
 592                 return do_show(0, NULL);
 593
 594         fprintf(stderr, "Command \"%s\" is unknown, try \"ip tunnel help\"\n", *argv);
 595         exit(-1);
 596 }