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  * Changes:
  13  *
  14  * Rani Assaf <rani@magic.metawire.com> 980929: resolve addresses
  15  * Rani Assaf <rani@magic.metawire.com> 980930: do not allow key for ipip/sit
  16  * Phil Karn <karn@ka9q.ampr.org>       990408: "pmtudisc" flag
  17  */
  18
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <string.h>
  22 #include <unistd.h>
  23 #include <sys/types.h>
  24 #include <sys/socket.h>
  25 #include <arpa/inet.h>
  26 #include <sys/ioctl.h>
  27 #include <linux/if.h>
  28 #include <linux/if_arp.h>
  29 #include <linux/ip.h>
  30 #include <linux/if_tunnel.h>
  31
  32 #include "rt_names.h"
  33 #include "utils.h"
  34 #include "ip_common.h"
  35 #include "tunnel.h"
  36
  37 static void usage(void) __attribute__((noreturn));
  38
  39 static void usage(void)
  40 {
  41         fprintf(stderr, "Usage: ip tunnel { add | change | del | show } [ NAME ]\n");
  42         fprintf(stderr, "          [ mode { ipip | gre | sit | isatap } ] [ remote ADDR ] [ local ADDR ]\n");
  43         fprintf(stderr, "          [ [i|o]seq ] [ [i|o]key KEY ] [ [i|o]csum ]\n");
  44         fprintf(stderr, "          [ ttl TTL ] [ tos TOS ] [ [no]pmtudisc ] [ dev PHYS_DEV ]\n");
  45         fprintf(stderr, "\n");
  46         fprintf(stderr, "Where: NAME := STRING\n");
  47         fprintf(stderr, "       ADDR := { IP_ADDRESS | any }\n");
  48         fprintf(stderr, "       TOS  := { NUMBER | inherit }\n");
  49         fprintf(stderr, "       TTL  := { 1..255 | inherit }\n");
  50         fprintf(stderr, "       KEY  := { DOTTED_QUAD | NUMBER }\n");
  51         exit(-1);
  52 }
  53
  54 static int parse_args(int argc, char **argv, int cmd, struct ip_tunnel_parm *p)
  55 {
  56         int count = 0;
  57         char medium[IFNAMSIZ];
  58         int isatap = 0;
  59
  60         memset(p, 0, sizeof(*p));
  61         memset(&medium, 0, sizeof(medium));
  62
  63         p->iph.version = 4;
  64         p->iph.ihl = 5;
  65 #ifndef IP_DF
  66 #define IP_DF           0x4000          /* Flag: "Don't Fragment"       */
  67 #endif
  68         p->iph.frag_off = htons(IP_DF);
  69
  70         while (argc > 0) {
  71                 if (strcmp(*argv, "mode") == 0) {
  72                         NEXT_ARG();
  73                         if (strcmp(*argv, "ipip") == 0 ||
  74                             strcmp(*argv, "ip/ip") == 0) {
  75                                 if (p->iph.protocol && p->iph.protocol != IPPROTO_IPIP) {
  76                                         fprintf(stderr,"You managed to ask for more than one tunnel mode.\n");
  77                                         exit(-1);
  78                                 }
  79                                 p->iph.protocol = IPPROTO_IPIP;
  80                         } else if (strcmp(*argv, "gre") == 0 ||
  81                                    strcmp(*argv, "gre/ip") == 0) {
  82                                 if (p->iph.protocol && p->iph.protocol != IPPROTO_GRE) {
  83                                         fprintf(stderr,"You managed to ask for more than one tunnel mode.\n");
  84                                         exit(-1);
  85                                 }
  86                                 p->iph.protocol = IPPROTO_GRE;
  87                         } else if (strcmp(*argv, "sit") == 0 ||
  88                                    strcmp(*argv, "ipv6/ip") == 0) {
  89                                 if (p->iph.protocol && p->iph.protocol != IPPROTO_IPV6) {
  90                                         fprintf(stderr,"You managed to ask for more than one tunnel mode.\n");
  91                                         exit(-1);
  92                                 }
  93                                 p->iph.protocol = IPPROTO_IPV6;
  94                         } else if (strcmp(*argv, "isatap") == 0) {
  95                                 if (p->iph.protocol && p->iph.protocol != IPPROTO_IPV6) {
  96                                         fprintf(stderr, "You managed to ask for more than one tunnel mode.\n");
  97                                         exit(-1);
  98                                 }
  99                                 p->iph.protocol = IPPROTO_IPV6;
 100                                 isatap++;
 101                         } else {
 102                                 fprintf(stderr,"Cannot guess tunnel mode.\n");
 103                                 exit(-1);
 104                         }
 105                 } else if (strcmp(*argv, "key") == 0) {
 106                         unsigned uval;
 107                         NEXT_ARG();
 108                         p->i_flags |= GRE_KEY;
 109                         p->o_flags |= GRE_KEY;
 110                         if (strchr(*argv, '.'))
 111                                 p->i_key = p->o_key = get_addr32(*argv);
 112                         else {
 113                                 if (get_unsigned(&uval, *argv, 0)<0) {
 114                                         fprintf(stderr, "invalid value of \"key\"\n");
 115                                         exit(-1);
 116                                 }
 117                                 p->i_key = p->o_key = htonl(uval);
 118                         }
 119                 } else if (strcmp(*argv, "ikey") == 0) {
 120                         unsigned uval;
 121                         NEXT_ARG();
 122                         p->i_flags |= GRE_KEY;
 123                         if (strchr(*argv, '.'))
 124                                 p->i_key = get_addr32(*argv);
 125                         else {
 126                                 if (get_unsigned(&uval, *argv, 0)<0) {
 127                                         fprintf(stderr, "invalid value of \"ikey\"\n");
 128                                         exit(-1);
 129                                 }
 130                                 p->i_key = htonl(uval);
 131                         }
 132                 } else if (strcmp(*argv, "okey") == 0) {
 133                         unsigned uval;
 134                         NEXT_ARG();
 135                         p->o_flags |= GRE_KEY;
 136                         if (strchr(*argv, '.'))
 137                                 p->o_key = get_addr32(*argv);
 138                         else {
 139                                 if (get_unsigned(&uval, *argv, 0)<0) {
 140                                         fprintf(stderr, "invalid value of \"okey\"\n");
 141                                         exit(-1);
 142                                 }
 143                                 p->o_key = htonl(uval);
 144                         }
 145                 } else if (strcmp(*argv, "seq") == 0) {
 146                         p->i_flags |= GRE_SEQ;
 147                         p->o_flags |= GRE_SEQ;
 148                 } else if (strcmp(*argv, "iseq") == 0) {
 149                         p->i_flags |= GRE_SEQ;
 150                 } else if (strcmp(*argv, "oseq") == 0) {
 151                         p->o_flags |= GRE_SEQ;
 152                 } else if (strcmp(*argv, "csum") == 0) {
 153                         p->i_flags |= GRE_CSUM;
 154                         p->o_flags |= GRE_CSUM;
 155                 } else if (strcmp(*argv, "icsum") == 0) {
 156                         p->i_flags |= GRE_CSUM;
 157                 } else if (strcmp(*argv, "ocsum") == 0) {
 158                         p->o_flags |= GRE_CSUM;
 159                 } else if (strcmp(*argv, "nopmtudisc") == 0) {
 160                         p->iph.frag_off = 0;
 161                 } else if (strcmp(*argv, "pmtudisc") == 0) {
 162                         p->iph.frag_off = htons(IP_DF);
 163                 } else if (strcmp(*argv, "remote") == 0) {
 164                         NEXT_ARG();
 165                         if (strcmp(*argv, "any"))
 166                                 p->iph.daddr = get_addr32(*argv);
 167                 } else if (strcmp(*argv, "local") == 0) {
 168                         NEXT_ARG();
 169                         if (strcmp(*argv, "any"))
 170                                 p->iph.saddr = get_addr32(*argv);
 171                 } else if (strcmp(*argv, "dev") == 0) {
 172                         NEXT_ARG();
 173                         strncpy(medium, *argv, IFNAMSIZ-1);
 174                 } else if (strcmp(*argv, "ttl") == 0 ||
 175                            strcmp(*argv, "hoplimit") == 0) {
 176                         unsigned uval;
 177                         NEXT_ARG();
 178                         if (strcmp(*argv, "inherit") != 0) {
 179                                 if (get_unsigned(&uval, *argv, 0))
 180                                         invarg("invalid TTL\n", *argv);
 181                                 if (uval > 255)
 182                                         invarg("TTL must be <=255\n", *argv);
 183                                 p->iph.ttl = uval;
 184                         }
 185                 } else if (strcmp(*argv, "tos") == 0 ||
 186                            strcmp(*argv, "tclass") == 0 ||
 187                            matches(*argv, "dsfield") == 0) {
 188                         __u32 uval;
 189                         NEXT_ARG();
 190                         if (strcmp(*argv, "inherit") != 0) {
 191                                 if (rtnl_dsfield_a2n(&uval, *argv))
 192                                         invarg("bad TOS value", *argv);
 193                                 p->iph.tos = uval;
 194                         } else
 195                                 p->iph.tos = 1;
 196                 } else {
 197                         if (strcmp(*argv, "name") == 0) {
 198                                 NEXT_ARG();
 199                         } else if (matches(*argv, "help") == 0)
 200                                 usage();
 201                         if (p->name[0])
 202                                 duparg2("name", *argv);
 203                         strncpy(p->name, *argv, IFNAMSIZ);
 204                         if (cmd == SIOCCHGTUNNEL && count == 0) {
 205                                 struct ip_tunnel_parm old_p;
 206                                 memset(&old_p, 0, sizeof(old_p));
 207                                 if (tnl_get_ioctl(*argv, &old_p))
 208                                         return -1;
 209                                 *p = old_p;
 210                         }
 211                 }
 212                 count++;
 213                 argc--; argv++;
 214         }
 215
 216
 217         if (p->iph.protocol == 0) {
 218                 if (memcmp(p->name, "gre", 3) == 0)
 219                         p->iph.protocol = IPPROTO_GRE;
 220                 else if (memcmp(p->name, "ipip", 4) == 0)
 221                         p->iph.protocol = IPPROTO_IPIP;
 222                 else if (memcmp(p->name, "sit", 3) == 0)
 223                         p->iph.protocol = IPPROTO_IPV6;
 224                 else if (memcmp(p->name, "isatap", 6) == 0) {
 225                         p->iph.protocol = IPPROTO_IPV6;
 226                         isatap++;
 227                 }
 228         }
 229
 230         if (p->iph.protocol == IPPROTO_IPIP || p->iph.protocol == IPPROTO_IPV6) {
 231                 if ((p->i_flags & GRE_KEY) || (p->o_flags & GRE_KEY)) {
 232                         fprintf(stderr, "Keys are not allowed with ipip and sit.\n");
 233                         return -1;
 234                 }
 235         }
 236
 237         if (medium[0]) {
 238                 p->link = tnl_ioctl_get_ifindex(medium);
 239                 if (p->link == 0)
 240                         return -1;
 241         }
 242
 243         if (p->i_key == 0 && IN_MULTICAST(ntohl(p->iph.daddr))) {
 244                 p->i_key = p->iph.daddr;
 245                 p->i_flags |= GRE_KEY;
 246         }
 247         if (p->o_key == 0 && IN_MULTICAST(ntohl(p->iph.daddr))) {
 248                 p->o_key = p->iph.daddr;
 249                 p->o_flags |= GRE_KEY;
 250         }
 251         if (IN_MULTICAST(ntohl(p->iph.daddr)) && !p->iph.saddr) {
 252                 fprintf(stderr, "Broadcast tunnel requires a source address.\n");
 253                 return -1;
 254         }
 255         if (isatap) {
 256                 if (p->iph.daddr) {
 257                         fprintf(stderr, "no remote with isatap.\n");
 258                         return -1;
 259                 }
 260                 p->i_flags |= SIT_ISATAP;
 261         }
 262
 263         return 0;
 264 }
 265
 266
 267 static int do_add(int cmd, int argc, char **argv)
 268 {
 269         struct ip_tunnel_parm p;
 270
 271         if (parse_args(argc, argv, cmd, &p) < 0)
 272                 return -1;
 273
 274         if (p.iph.ttl && p.iph.frag_off == 0) {
 275                 fprintf(stderr, "ttl != 0 and noptmudisc are incompatible\n");
 276                 return -1;
 277         }
 278
 279         switch (p.iph.protocol) {
 280         case IPPROTO_IPIP:
 281                 return tnl_add_ioctl(cmd, "tunl0", p.name, &p);
 282         case IPPROTO_GRE:
 283                 return tnl_add_ioctl(cmd, "gre0", p.name, &p);
 284         case IPPROTO_IPV6:
 285                 return tnl_add_ioctl(cmd, "sit0", p.name, &p);
 286         default:
 287                 fprintf(stderr, "cannot determine tunnel mode (ipip, gre or sit)\n");
 288                 return -1;
 289         }
 290         return -1;
 291 }
 292
 293 static int do_del(int argc, char **argv)
 294 {
 295         struct ip_tunnel_parm p;
 296
 297         if (parse_args(argc, argv, SIOCDELTUNNEL, &p) < 0)
 298                 return -1;
 299
 300         switch (p.iph.protocol) {
 301         case IPPROTO_IPIP:
 302                 return tnl_del_ioctl("tunl0", p.name, &p);
 303         case IPPROTO_GRE:
 304                 return tnl_del_ioctl("gre0", p.name, &p);
 305         case IPPROTO_IPV6:
 306                 return tnl_del_ioctl("sit0", p.name, &p);
 307         default:
 308                 return tnl_del_ioctl(p.name, p.name, &p);
 309         }
 310         return -1;
 311 }
 312
 313 static void print_tunnel(struct ip_tunnel_parm *p)
 314 {
 315         char s1[1024];
 316         char s2[1024];
 317         char s3[64];
 318         char s4[64];
 319
 320         inet_ntop(AF_INET, &p->i_key, s3, sizeof(s3));
 321         inet_ntop(AF_INET, &p->o_key, s4, sizeof(s4));
 322
 323         /* Do not use format_host() for local addr,
 324          * symbolic name will not be useful.
 325          */
 326         printf("%s: %s/ip  remote %s  local %s ",
 327                p->name,
 328                tnl_strproto(p->iph.protocol),
 329                p->iph.daddr ? format_host(AF_INET, 4, &p->iph.daddr, s1, sizeof(s1))  : "any",
 330                p->iph.saddr ? rt_addr_n2a(AF_INET, 4, &p->iph.saddr, s2, sizeof(s2)) : "any");
 331
 332         if (p->link) {
 333                 char *n = tnl_ioctl_get_ifname(p->link);
 334                 if (n)
 335                         printf(" dev %s ", n);
 336         }
 337
 338         if (p->iph.ttl)
 339                 printf(" ttl %d ", p->iph.ttl);
 340         else
 341                 printf(" ttl inherit ");
 342
 343         if (p->iph.tos) {
 344                 SPRINT_BUF(b1);
 345                 printf(" tos");
 346                 if (p->iph.tos&1)
 347                         printf(" inherit");
 348                 if (p->iph.tos&~1)
 349                         printf("%c%s ", p->iph.tos&1 ? '/' : ' ',
 350                                rtnl_dsfield_n2a(p->iph.tos&~1, b1, sizeof(b1)));
 351         }
 352
 353         if (!(p->iph.frag_off&htons(IP_DF)))
 354                 printf(" nopmtudisc");
 355
 356         if ((p->i_flags&GRE_KEY) && (p->o_flags&GRE_KEY) && p->o_key == p->i_key)
 357                 printf(" key %s", s3);
 358         else if ((p->i_flags|p->o_flags)&GRE_KEY) {
 359                 if (p->i_flags&GRE_KEY)
 360                         printf(" ikey %s ", s3);
 361                 if (p->o_flags&GRE_KEY)
 362                         printf(" okey %s ", s4);
 363         }
 364
 365         if (p->i_flags&GRE_SEQ)
 366                 printf("%s  Drop packets out of sequence.\n", _SL_);
 367         if (p->i_flags&GRE_CSUM)
 368                 printf("%s  Checksum in received packet is required.", _SL_);
 369         if (p->o_flags&GRE_SEQ)
 370                 printf("%s  Sequence packets on output.", _SL_);
 371         if (p->o_flags&GRE_CSUM)
 372                 printf("%s  Checksum output packets.", _SL_);
 373 }
 374
 375 static int do_tunnels_list(struct ip_tunnel_parm *p)
 376 {
 377         char name[IFNAMSIZ];
 378         unsigned long  rx_bytes, rx_packets, rx_errs, rx_drops,
 379         rx_fifo, rx_frame,
 380         tx_bytes, tx_packets, tx_errs, tx_drops,
 381         tx_fifo, tx_colls, tx_carrier, rx_multi;
 382         int type;
 383         struct ip_tunnel_parm p1;
 384
 385         char buf[512];
 386         FILE *fp = fopen("/proc/net/dev", "r");
 387         if (fp == NULL) {
 388                 perror("fopen");
 389                 return -1;
 390         }
 391
 392         fgets(buf, sizeof(buf), fp);
 393         fgets(buf, sizeof(buf), fp);
 394
 395         while (fgets(buf, sizeof(buf), fp) != NULL) {
 396                 char *ptr;
 397                 buf[sizeof(buf) - 1] = 0;
 398                 if ((ptr = strchr(buf, ':')) == NULL ||
 399                     (*ptr++ = 0, sscanf(buf, "%s", name) != 1)) {
 400                         fprintf(stderr, "Wrong format of /proc/net/dev. Sorry.\n");
 401                         return -1;
 402                 }
 403                 if (sscanf(ptr, "%ld%ld%ld%ld%ld%ld%ld%*d%ld%ld%ld%ld%ld%ld%ld",
 404                            &rx_bytes, &rx_packets, &rx_errs, &rx_drops,
 405                            &rx_fifo, &rx_frame, &rx_multi,
 406                            &tx_bytes, &tx_packets, &tx_errs, &tx_drops,
 407                            &tx_fifo, &tx_colls, &tx_carrier) != 14)
 408                         continue;
 409                 if (p->name[0] && strcmp(p->name, name))
 410                         continue;
 411                 type = tnl_ioctl_get_iftype(name);
 412                 if (type == -1) {
 413                         fprintf(stderr, "Failed to get type of [%s]\n", name);
 414                         continue;
 415                 }
 416                 if (type != ARPHRD_TUNNEL && type != ARPHRD_IPGRE && type != ARPHRD_SIT)
 417                         continue;
 418                 memset(&p1, 0, sizeof(p1));
 419                 if (tnl_get_ioctl(name, &p1))
 420                         continue;
 421                 if ((p->link && p1.link != p->link) ||
 422                     (p->name[0] && strcmp(p1.name, p->name)) ||
 423                     (p->iph.daddr && p1.iph.daddr != p->iph.daddr) ||
 424                     (p->iph.saddr && p1.iph.saddr != p->iph.saddr) ||
 425                     (p->i_key && p1.i_key != p->i_key))
 426                         continue;
 427                 print_tunnel(&p1);
 428                 if (show_stats) {
 429                         printf("%s", _SL_);
 430                         printf("RX: Packets    Bytes        Errors CsumErrs OutOfSeq Mcasts%s", _SL_);
 431                         printf("    %-10ld %-12ld %-6ld %-8ld %-8ld %-8ld%s",
 432                                rx_packets, rx_bytes, rx_errs, rx_frame, rx_fifo, rx_multi, _SL_);
 433                         printf("TX: Packets    Bytes        Errors DeadLoop NoRoute  NoBufs%s", _SL_);
 434                         printf("    %-10ld %-12ld %-6ld %-8ld %-8ld %-6ld",
 435                                tx_packets, tx_bytes, tx_errs, tx_colls, tx_carrier, tx_drops);
 436                 }
 437                 printf("\n");
 438         }
 439         return 0;
 440 }
 441
 442 static int do_show(int argc, char **argv)
 443 {
 444         int err;
 445         struct ip_tunnel_parm p;
 446
 447         if (parse_args(argc, argv, SIOCGETTUNNEL, &p) < 0)
 448                 return -1;
 449
 450         switch (p.iph.protocol) {
 451         case IPPROTO_IPIP:
 452                 err = tnl_get_ioctl(p.name[0] ? p.name : "tunl0", &p);
 453                 break;
 454         case IPPROTO_GRE:
 455                 err = tnl_get_ioctl(p.name[0] ? p.name : "gre0", &p);
 456                 break;
 457         case IPPROTO_IPV6:
 458                 err = tnl_get_ioctl(p.name[0] ? p.name : "sit0", &p);
 459                 break;
 460         default:
 461                 do_tunnels_list(&p);
 462                 return 0;
 463         }
 464         if (err)
 465                 return -1;
 466
 467         print_tunnel(&p);
 468         printf("\n");
 469         return 0;
 470 }
 471
 472 int do_iptunnel(int argc, char **argv)
 473 {
 474         switch (preferred_family) {
 475         case AF_UNSPEC:
 476                 preferred_family = AF_INET;
 477                 break;
 478         case AF_INET:
 479                 break;
 480         /*
 481          * This is silly enough but we have no easy way to make it
 482          * protocol-independent because of unarranged structure between
 483          * IPv4 and IPv6.
 484          */
 485         case AF_INET6:
 486                 return do_ip6tunnel(argc, argv);
 487         default:
 488                 fprintf(stderr, "Unsupported family:%d\n", preferred_family);
 489                 exit(-1);
 490         }
 491
 492         if (argc > 0) {
 493                 if (matches(*argv, "add") == 0)
 494                         return do_add(SIOCADDTUNNEL, argc-1, argv+1);
 495                 if (matches(*argv, "change") == 0)
 496                         return do_add(SIOCCHGTUNNEL, argc-1, argv+1);
 497                 if (matches(*argv, "del") == 0)
 498                         return do_del(argc-1, argv+1);
 499                 if (matches(*argv, "show") == 0 ||
 500                     matches(*argv, "lst") == 0 ||
 501                     matches(*argv, "list") == 0)
 502                         return do_show(argc-1, argv+1);
 503                 if (matches(*argv, "help") == 0)
 504                         usage();
 505         } else
 506                 return do_show(0, NULL);
 507
 508         fprintf(stderr, "Command \"%s\" is unknown, try \"ip tunnel help\".\n", *argv);
 509         exit(-1);
 510 }