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         char s1[1024];
 293         char s2[1024];
 294
 295         /* Do not use format_host() for local addr,
 296          * symbolic name will not be useful.
 297          */
 298         printf("%s: %s/ip remote %s local %s",
 299                p->name,
 300                tnl_strproto(p->iph.protocol),
 301                p->iph.daddr ? format_host_r(AF_INET, 4, &p->iph.daddr, s1, sizeof(s1)) : "any",
 302                p->iph.saddr ? rt_addr_n2a_r(AF_INET, 4, &p->iph.saddr, s2, sizeof(s2)) : "any");
 303
 304         if (p->iph.protocol == IPPROTO_IPV6 && (p->i_flags & SIT_ISATAP)) {
 305                 struct ip_tunnel_prl prl[16] = {};
 306                 int i;
 307
 308                 prl[0].datalen = sizeof(prl) - sizeof(prl[0]);
 309                 prl[0].addr = htonl(INADDR_ANY);
 310
 311                 if (!tnl_prl_ioctl(SIOCGETPRL, p->name, prl))
 312                         for (i = 1; i < ARRAY_SIZE(prl); i++) {
 313                                 if (prl[i].addr != htonl(INADDR_ANY)) {
 314                                         printf(" %s %s ",
 315                                                (prl[i].flags & PRL_DEFAULT) ? "pdr" : "pr",
 316                                                format_host(AF_INET, 4, &prl[i].addr));
 317                                 }
 318                         }
 319         }
 320
 321         if (p->link) {
 322                 const char *n = ll_index_to_name(p->link);
 323
 324                 if (n)
 325                         printf(" dev %s", n);
 326         }
 327
 328         if (p->iph.ttl)
 329                 printf(" ttl %u", p->iph.ttl);
 330         else
 331                 printf(" ttl inherit");
 332
 333         if (p->iph.tos) {
 334                 SPRINT_BUF(b1);
 335                 printf(" tos");
 336                 if (p->iph.tos & 1)
 337                         printf(" inherit");
 338                 if (p->iph.tos & ~1)
 339                         printf("%c%s ", p->iph.tos & 1 ? '/' : ' ',
 340                                rtnl_dsfield_n2a(p->iph.tos & ~1, b1, sizeof(b1)));
 341         }
 342
 343         if (!(p->iph.frag_off & htons(IP_DF)))
 344                 printf(" nopmtudisc");
 345
 346         if (p->iph.protocol == IPPROTO_IPV6 && !tnl_ioctl_get_6rd(p->name, &ip6rd) && ip6rd.prefixlen) {
 347                 printf(" 6rd-prefix %s/%u",
 348                        inet_ntop(AF_INET6, &ip6rd.prefix, s1, sizeof(s1)),
 349                        ip6rd.prefixlen);
 350                 if (ip6rd.relay_prefix) {
 351                         printf(" 6rd-relay_prefix %s/%u",
 352                                format_host(AF_INET, 4, &ip6rd.relay_prefix),
 353                                ip6rd.relay_prefixlen);
 354                 }
 355         }
 356
 357         if ((p->i_flags & GRE_KEY) && (p->o_flags & GRE_KEY) && p->o_key == p->i_key)
 358                 printf(" key %u", ntohl(p->i_key));
 359         else if ((p->i_flags | p->o_flags) & GRE_KEY) {
 360                 if (p->i_flags & GRE_KEY)
 361                         printf(" ikey %u", ntohl(p->i_key));
 362                 if (p->o_flags & GRE_KEY)
 363                         printf(" okey %u", ntohl(p->o_key));
 364         }
 365
 366         if (p->i_flags & GRE_SEQ)
 367                 printf("%s  Drop packets out of sequence.", _SL_);
 368         if (p->i_flags & GRE_CSUM)
 369                 printf("%s  Checksum in received packet is required.", _SL_);
 370         if (p->o_flags & GRE_SEQ)
 371                 printf("%s  Sequence packets on output.", _SL_);
 372         if (p->o_flags & GRE_CSUM)
 373                 printf("%s  Checksum output packets.", _SL_);
 374 }
 375
 376
 377 static void ip_tunnel_parm_initialize(const struct tnl_print_nlmsg_info *info)
 378 {
 379         struct ip_tunnel_parm *p2 = info->p2;
 380
 381         memset(p2, 0, sizeof(*p2));
 382 }
 383
 384 static bool ip_tunnel_parm_match(const struct tnl_print_nlmsg_info *info)
 385 {
 386         const struct ip_tunnel_parm *p1 = info->p1;
 387         const struct ip_tunnel_parm *p2 = info->p2;
 388
 389         return ((!p1->link || p1->link == p2->link) &&
 390                 (!p1->name[0] || strcmp(p1->name, p2->name) == 0) &&
 391                 (!p1->iph.daddr || p1->iph.daddr == p2->iph.daddr) &&
 392                 (!p1->iph.saddr || p1->iph.saddr == p2->iph.saddr) &&
 393                 (!p1->i_key || p1->i_key == p2->i_key));
 394 }
 395
 396 static int do_show(int argc, char **argv)
 397 {
 398         struct ip_tunnel_parm p, p1;
 399         const char *basedev;
 400
 401         if (parse_args(argc, argv, SIOCGETTUNNEL, &p) < 0)
 402                 return -1;
 403
 404         basedev = tnl_defname(&p);
 405         if (!basedev) {
 406                 struct tnl_print_nlmsg_info info = {
 407                         .p1    = &p,
 408                         .p2    = &p1,
 409                         .init  = ip_tunnel_parm_initialize,
 410                         .match = ip_tunnel_parm_match,
 411                         .print = print_tunnel,
 412                 };
 413
 414                 return do_tunnels_list(&info);
 415         }
 416
 417         if (tnl_get_ioctl(p.name[0] ? p.name : basedev, &p))
 418                 return -1;
 419
 420         print_tunnel(&p);
 421         fputc('\n', stdout);
 422         return 0;
 423 }
 424
 425 static int do_prl(int argc, char **argv)
 426 {
 427         struct ip_tunnel_prl p = {};
 428         int count = 0;
 429         int cmd = 0;
 430         const char *medium = NULL;
 431
 432         while (argc > 0) {
 433                 if (strcmp(*argv, "prl-default") == 0) {
 434                         NEXT_ARG();
 435                         cmd = SIOCADDPRL;
 436                         p.addr = get_addr32(*argv);
 437                         p.flags |= PRL_DEFAULT;
 438                         count++;
 439                 } else if (strcmp(*argv, "prl-nodefault") == 0) {
 440                         NEXT_ARG();
 441                         cmd = SIOCADDPRL;
 442                         p.addr = get_addr32(*argv);
 443                         count++;
 444                 } else if (strcmp(*argv, "prl-delete") == 0) {
 445                         NEXT_ARG();
 446                         cmd = SIOCDELPRL;
 447                         p.addr = get_addr32(*argv);
 448                         count++;
 449                 } else if (strcmp(*argv, "dev") == 0) {
 450                         NEXT_ARG();
 451                         if (check_ifname(*argv))
 452                                 invarg("\"dev\" not a valid ifname", *argv);
 453                         medium = *argv;
 454                 } else {
 455                         fprintf(stderr,
 456                                 "Invalid PRL parameter \"%s\"\n", *argv);
 457                         exit(-1);
 458                 }
 459                 if (count > 1) {
 460                         fprintf(stderr,
 461                                 "One PRL entry at a time\n");
 462                         exit(-1);
 463                 }
 464                 argc--; argv++;
 465         }
 466         if (!medium) {
 467                 fprintf(stderr, "Must specify device\n");
 468                 exit(-1);
 469         }
 470
 471         return tnl_prl_ioctl(cmd, medium, &p);
 472 }
 473
 474 static int do_6rd(int argc, char **argv)
 475 {
 476         struct ip_tunnel_6rd ip6rd = {};
 477         int cmd = 0;
 478         const char *medium = NULL;
 479         inet_prefix prefix;
 480
 481         while (argc > 0) {
 482                 if (strcmp(*argv, "6rd-prefix") == 0) {
 483                         NEXT_ARG();
 484                         if (get_prefix(&prefix, *argv, AF_INET6))
 485                                 invarg("invalid 6rd_prefix\n", *argv);
 486                         cmd = SIOCADD6RD;
 487                         memcpy(&ip6rd.prefix, prefix.data, 16);
 488                         ip6rd.prefixlen = prefix.bitlen;
 489                 } else if (strcmp(*argv, "6rd-relay_prefix") == 0) {
 490                         NEXT_ARG();
 491                         if (get_prefix(&prefix, *argv, AF_INET))
 492                                 invarg("invalid 6rd-relay_prefix\n", *argv);
 493                         cmd = SIOCADD6RD;
 494                         memcpy(&ip6rd.relay_prefix, prefix.data, 4);
 495                         ip6rd.relay_prefixlen = prefix.bitlen;
 496                 } else if (strcmp(*argv, "6rd-reset") == 0) {
 497                         cmd = SIOCDEL6RD;
 498                 } else if (strcmp(*argv, "dev") == 0) {
 499                         NEXT_ARG();
 500                         if (check_ifname(*argv))
 501                                 invarg("\"dev\" not a valid ifname", *argv);
 502                         medium = *argv;
 503                 } else {
 504                         fprintf(stderr,
 505                                 "Invalid 6RD parameter \"%s\"\n", *argv);
 506                         exit(-1);
 507                 }
 508                 argc--; argv++;
 509         }
 510         if (!medium) {
 511                 fprintf(stderr, "Must specify device\n");
 512                 exit(-1);
 513         }
 514
 515         return tnl_6rd_ioctl(cmd, medium, &ip6rd);
 516 }
 517
 518 static int tunnel_mode_is_ipv6(char *tunnel_mode)
 519 {
 520         static const char * const ipv6_modes[] = {
 521                 "ipv6/ipv6", "ip6ip6",
 522                 "vti6",
 523                 "ip/ipv6", "ipv4/ipv6", "ipip6", "ip4ip6",
 524                 "ip6gre", "gre/ipv6",
 525                 "any/ipv6", "any"
 526         };
 527         int i;
 528
 529         for (i = 0; i < ARRAY_SIZE(ipv6_modes); i++) {
 530                 if (strcmp(ipv6_modes[i], tunnel_mode) == 0)
 531                         return 1;
 532         }
 533         return 0;
 534 }
 535
 536 int do_iptunnel(int argc, char **argv)
 537 {
 538         int i;
 539
 540         for (i = 0; i < argc - 1; i++) {
 541                 if (strcmp(argv[i], "mode") == 0) {
 542                         if (tunnel_mode_is_ipv6(argv[i + 1]))
 543                                 preferred_family = AF_INET6;
 544                         break;
 545                 }
 546         }
 547         switch (preferred_family) {
 548         case AF_UNSPEC:
 549                 preferred_family = AF_INET;
 550                 break;
 551         case AF_INET:
 552                 break;
 553         /*
 554          * This is silly enough but we have no easy way to make it
 555          * protocol-independent because of unarranged structure between
 556          * IPv4 and IPv6.
 557          */
 558         case AF_INET6:
 559                 return do_ip6tunnel(argc, argv);
 560         default:
 561                 fprintf(stderr, "Unsupported protocol family: %d\n", preferred_family);
 562                 exit(-1);
 563         }
 564
 565         if (argc > 0) {
 566                 if (matches(*argv, "add") == 0)
 567                         return do_add(SIOCADDTUNNEL, argc - 1, argv + 1);
 568                 if (matches(*argv, "change") == 0)
 569                         return do_add(SIOCCHGTUNNEL, argc - 1, argv + 1);
 570                 if (matches(*argv, "delete") == 0)
 571                         return do_del(argc - 1, argv + 1);
 572                 if (matches(*argv, "show") == 0 ||
 573                     matches(*argv, "lst") == 0 ||
 574                     matches(*argv, "list") == 0)
 575                         return do_show(argc - 1, argv + 1);
 576                 if (matches(*argv, "prl") == 0)
 577                         return do_prl(argc - 1, argv + 1);
 578                 if (matches(*argv, "6rd") == 0)
 579                         return do_6rd(argc - 1, argv + 1);
 580                 if (matches(*argv, "help") == 0)
 581                         usage();
 582         } else
 583                 return do_show(0, NULL);
 584
 585         fprintf(stderr, "Command \"%s\" is unknown, try \"ip tunnel help\"\n", *argv);
 586         exit(-1);
 587 }