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 <syslog.h>
  24 #include <fcntl.h>
  25 #include <sys/socket.h>
  26 #include <sys/ioctl.h>
  27 #include <linux/if.h>
  28 #include <linux/if_arp.h>
  29 #include <netinet/in.h>
  30 #include <netinet/ip.h>
  31 #include <arpa/inet.h>
  32 #include <linux/if_tunnel.h>
  33
  34 #include "rt_names.h"
  35 #include "utils.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 } ] [ 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 do_ioctl_get_ifindex(char *dev)
  55 {
  56         struct ifreq ifr;
  57         int fd;
  58         int err;
  59
  60         strcpy(ifr.ifr_name, dev);
  61         fd = socket(AF_INET, SOCK_DGRAM, 0);
  62         err = ioctl(fd, SIOCGIFINDEX, &ifr);
  63         if (err) {
  64                 perror("ioctl");
  65                 return 0;
  66         }
  67         close(fd);
  68         return ifr.ifr_ifindex;
  69 }
  70
  71 static int do_ioctl_get_iftype(char *dev)
  72 {
  73         struct ifreq ifr;
  74         int fd;
  75         int err;
  76
  77         strcpy(ifr.ifr_name, dev);
  78         fd = socket(AF_INET, SOCK_DGRAM, 0);
  79         err = ioctl(fd, SIOCGIFHWADDR, &ifr);
  80         if (err) {
  81                 perror("ioctl");
  82                 return -1;
  83         }
  84         close(fd);
  85         return ifr.ifr_addr.sa_family;
  86 }
  87
  88
  89 static char * do_ioctl_get_ifname(int idx)
  90 {
  91         static struct ifreq ifr;
  92         int fd;
  93         int err;
  94
  95         ifr.ifr_ifindex = idx;
  96         fd = socket(AF_INET, SOCK_DGRAM, 0);
  97         err = ioctl(fd, SIOCGIFNAME, &ifr);
  98         if (err) {
  99                 perror("ioctl");
 100                 return NULL;
 101         }
 102         close(fd);
 103         return ifr.ifr_name;
 104 }
 105
 106
 107
 108 static int do_get_ioctl(char *basedev, struct ip_tunnel_parm *p)
 109 {
 110         struct ifreq ifr;
 111         int fd;
 112         int err;
 113
 114         strcpy(ifr.ifr_name, basedev);
 115         ifr.ifr_ifru.ifru_data = (void*)p;
 116         fd = socket(AF_INET, SOCK_DGRAM, 0);
 117         err = ioctl(fd, SIOCGETTUNNEL, &ifr);
 118         if (err)
 119                 perror("ioctl");
 120         close(fd);
 121         return err;
 122 }
 123
 124 static int do_add_ioctl(int cmd, char *basedev, struct ip_tunnel_parm *p)
 125 {
 126         struct ifreq ifr;
 127         int fd;
 128         int err;
 129
 130         if (cmd == SIOCCHGTUNNEL && p->name[0])
 131                 strcpy(ifr.ifr_name, p->name);
 132         else
 133                 strcpy(ifr.ifr_name, basedev);
 134         ifr.ifr_ifru.ifru_data = (void*)p;
 135         fd = socket(AF_INET, SOCK_DGRAM, 0);
 136         err = ioctl(fd, cmd, &ifr);
 137         if (err)
 138                 perror("ioctl");
 139         close(fd);
 140         return err;
 141 }
 142
 143 static int do_del_ioctl(char *basedev, struct ip_tunnel_parm *p)
 144 {
 145         struct ifreq ifr;
 146         int fd;
 147         int err;
 148
 149         if (p->name[0])
 150                 strcpy(ifr.ifr_name, p->name);
 151         else
 152                 strcpy(ifr.ifr_name, basedev);
 153         ifr.ifr_ifru.ifru_data = (void*)p;
 154         fd = socket(AF_INET, SOCK_DGRAM, 0);
 155         err = ioctl(fd, SIOCDELTUNNEL, &ifr);
 156         if (err)
 157                 perror("ioctl");
 158         close(fd);
 159         return err;
 160 }
 161
 162 static int parse_args(int argc, char **argv, int cmd, struct ip_tunnel_parm *p)
 163 {
 164         int count = 0;
 165         char medium[IFNAMSIZ];
 166
 167         memset(p, 0, sizeof(*p));
 168         memset(&medium, 0, sizeof(medium));
 169
 170         p->iph.version = 4;
 171         p->iph.ihl = 5;
 172 #ifndef IP_DF
 173 #define IP_DF           0x4000          /* Flag: "Don't Fragment"       */
 174 #endif
 175         p->iph.frag_off = htons(IP_DF);
 176
 177         while (argc > 0) {
 178                 if (strcmp(*argv, "mode") == 0) {
 179                         NEXT_ARG();
 180                         if (strcmp(*argv, "ipip") == 0 ||
 181                             strcmp(*argv, "ip/ip") == 0) {
 182                                 if (p->iph.protocol && p->iph.protocol != IPPROTO_IPIP) {
 183                                         fprintf(stderr,"You managed to ask for more than one tunnel mode.\n");
 184                                         exit(-1);
 185                                 }
 186                                 p->iph.protocol = IPPROTO_IPIP;
 187                         } else if (strcmp(*argv, "gre") == 0 ||
 188                                    strcmp(*argv, "gre/ip") == 0) {
 189                                 if (p->iph.protocol && p->iph.protocol != IPPROTO_GRE) {
 190                                         fprintf(stderr,"You managed to ask for more than one tunnel mode.\n");
 191                                         exit(-1);
 192                                 }
 193                                 p->iph.protocol = IPPROTO_GRE;
 194                         } else if (strcmp(*argv, "sit") == 0 ||
 195                                    strcmp(*argv, "ipv6/ip") == 0) {
 196                                 if (p->iph.protocol && p->iph.protocol != IPPROTO_IPV6) {
 197                                         fprintf(stderr,"You managed to ask for more than one tunnel mode.\n");
 198                                         exit(-1);
 199                                 }
 200                                 p->iph.protocol = IPPROTO_IPV6;
 201                         } else {
 202                                 fprintf(stderr,"Cannot guess tunnel mode.\n");
 203                                 exit(-1);
 204                         }
 205                 } else if (strcmp(*argv, "key") == 0) {
 206                         unsigned uval;
 207                         NEXT_ARG();
 208                         p->i_flags |= GRE_KEY;
 209                         p->o_flags |= GRE_KEY;
 210                         if (strchr(*argv, '.'))
 211                                 p->i_key = p->o_key = get_addr32(*argv);
 212                         else {
 213                                 if (get_unsigned(&uval, *argv, 0)<0) {
 214                                         fprintf(stderr, "invalid value of \"key\"\n");
 215                                         exit(-1);
 216                                 }
 217                                 p->i_key = p->o_key = htonl(uval);
 218                         }
 219                 } else if (strcmp(*argv, "ikey") == 0) {
 220                         unsigned uval;
 221                         NEXT_ARG();
 222                         p->i_flags |= GRE_KEY;
 223                         if (strchr(*argv, '.'))
 224                                 p->o_key = get_addr32(*argv);
 225                         else {
 226                                 if (get_unsigned(&uval, *argv, 0)<0) {
 227                                         fprintf(stderr, "invalid value of \"ikey\"\n");
 228                                         exit(-1);
 229                                 }
 230                                 p->i_key = htonl(uval);
 231                         }
 232                 } else if (strcmp(*argv, "okey") == 0) {
 233                         unsigned uval;
 234                         NEXT_ARG();
 235                         p->o_flags |= GRE_KEY;
 236                         if (strchr(*argv, '.'))
 237                                 p->o_key = get_addr32(*argv);
 238                         else {
 239                                 if (get_unsigned(&uval, *argv, 0)<0) {
 240                                         fprintf(stderr, "invalid value of \"okey\"\n");
 241                                         exit(-1);
 242                                 }
 243                                 p->o_key = htonl(uval);
 244                         }
 245                 } else if (strcmp(*argv, "seq") == 0) {
 246                         p->i_flags |= GRE_SEQ;
 247                         p->o_flags |= GRE_SEQ;
 248                 } else if (strcmp(*argv, "iseq") == 0) {
 249                         p->i_flags |= GRE_SEQ;
 250                 } else if (strcmp(*argv, "oseq") == 0) {
 251                         p->o_flags |= GRE_SEQ;
 252                 } else if (strcmp(*argv, "csum") == 0) {
 253                         p->i_flags |= GRE_CSUM;
 254                         p->o_flags |= GRE_CSUM;
 255                 } else if (strcmp(*argv, "icsum") == 0) {
 256                         p->i_flags |= GRE_CSUM;
 257                 } else if (strcmp(*argv, "ocsum") == 0) {
 258                         p->o_flags |= GRE_CSUM;
 259                 } else if (strcmp(*argv, "nopmtudisc") == 0) {
 260                         p->iph.frag_off = 0;
 261                 } else if (strcmp(*argv, "pmtudisc") == 0) {
 262                         p->iph.frag_off = htons(IP_DF);
 263                 } else if (strcmp(*argv, "remote") == 0) {
 264                         NEXT_ARG();
 265                         if (strcmp(*argv, "any"))
 266                                 p->iph.daddr = get_addr32(*argv);
 267                 } else if (strcmp(*argv, "local") == 0) {
 268                         NEXT_ARG();
 269                         if (strcmp(*argv, "any"))
 270                                 p->iph.saddr = get_addr32(*argv);
 271                 } else if (strcmp(*argv, "dev") == 0) {
 272                         NEXT_ARG();
 273                         strncpy(medium, *argv, IFNAMSIZ-1);
 274                 } else if (strcmp(*argv, "ttl") == 0) {
 275                         unsigned uval;
 276                         NEXT_ARG();
 277                         if (strcmp(*argv, "inherit") != 0) {
 278                                 if (get_unsigned(&uval, *argv, 0))
 279                                         invarg("invalid TTL\n", *argv);
 280                                 if (uval > 255)
 281                                         invarg("TTL must be <=255\n", *argv);
 282                                 p->iph.ttl = uval;
 283                         }
 284                 } else if (strcmp(*argv, "tos") == 0 ||
 285                            matches(*argv, "dsfield") == 0) {
 286                         __u32 uval;
 287                         NEXT_ARG();
 288                         if (strcmp(*argv, "inherit") != 0) {
 289                                 if (rtnl_dsfield_a2n(&uval, *argv))
 290                                         invarg("bad TOS value", *argv);
 291                                 p->iph.tos = uval;
 292                         } else
 293                                 p->iph.tos = 1;
 294                 } else {
 295                         if (strcmp(*argv, "name") == 0) {
 296                                 NEXT_ARG();
 297                         }
 298                         if (matches(*argv, "help") == 0)
 299                                 usage();
 300                         if (p->name[0])
 301                                 duparg2("name", *argv);
 302                         strncpy(p->name, *argv, IFNAMSIZ);
 303                         if (cmd == SIOCCHGTUNNEL && count == 0) {
 304                                 struct ip_tunnel_parm old_p;
 305                                 memset(&old_p, 0, sizeof(old_p));
 306                                 if (do_get_ioctl(*argv, &old_p))
 307                                         return -1;
 308                                 *p = old_p;
 309                         }
 310                 }
 311                 count++;
 312                 argc--; argv++;
 313         }
 314
 315
 316         if (p->iph.protocol == 0) {
 317                 if (memcmp(p->name, "gre", 3) == 0)
 318                         p->iph.protocol = IPPROTO_GRE;
 319                 else if (memcmp(p->name, "ipip", 4) == 0)
 320                         p->iph.protocol = IPPROTO_IPIP;
 321                 else if (memcmp(p->name, "sit", 3) == 0)
 322                         p->iph.protocol = IPPROTO_IPV6;
 323         }
 324
 325         if (p->iph.protocol == IPPROTO_IPIP || p->iph.protocol == IPPROTO_IPV6) {
 326                 if ((p->i_flags & GRE_KEY) || (p->o_flags & GRE_KEY)) {
 327                         fprintf(stderr, "Keys are not allowed with ipip and sit.\n");
 328                         return -1;
 329                 }
 330         }
 331
 332         if (medium[0]) {
 333                 p->link = do_ioctl_get_ifindex(medium);
 334                 if (p->link == 0)
 335                         return -1;
 336         }
 337
 338         if (p->i_key == 0 && IN_MULTICAST(ntohl(p->iph.daddr))) {
 339                 p->i_key = p->iph.daddr;
 340                 p->i_flags |= GRE_KEY;
 341         }
 342         if (p->o_key == 0 && IN_MULTICAST(ntohl(p->iph.daddr))) {
 343                 p->o_key = p->iph.daddr;
 344                 p->o_flags |= GRE_KEY;
 345         }
 346         if (IN_MULTICAST(ntohl(p->iph.daddr)) && !p->iph.saddr) {
 347                 fprintf(stderr, "Broadcast tunnel requires a source address.\n");
 348                 return -1;
 349         }
 350         return 0;
 351 }
 352
 353
 354 static int do_add(int cmd, int argc, char **argv)
 355 {
 356         struct ip_tunnel_parm p;
 357
 358         if (parse_args(argc, argv, cmd, &p) < 0)
 359                 return -1;
 360
 361         if (p.iph.ttl && p.iph.frag_off == 0) {
 362                 fprintf(stderr, "ttl != 0 and noptmudisc are incompatible\n");
 363                 return -1;
 364         }
 365
 366         switch (p.iph.protocol) {
 367         case IPPROTO_IPIP:
 368                 return do_add_ioctl(cmd, "tunl0", &p);
 369         case IPPROTO_GRE:
 370                 return do_add_ioctl(cmd, "gre0", &p);
 371         case IPPROTO_IPV6:
 372                 return do_add_ioctl(cmd, "sit0", &p);
 373         default:
 374                 fprintf(stderr, "cannot determine tunnel mode (ipip, gre or sit)\n");
 375                 return -1;
 376         }
 377         return -1;
 378 }
 379
 380 int do_del(int argc, char **argv)
 381 {
 382         struct ip_tunnel_parm p;
 383
 384         if (parse_args(argc, argv, SIOCDELTUNNEL, &p) < 0)
 385                 return -1;
 386
 387         switch (p.iph.protocol) {
 388         case IPPROTO_IPIP:
 389                 return do_del_ioctl("tunl0", &p);
 390         case IPPROTO_GRE:
 391                 return do_del_ioctl("gre0", &p);
 392         case IPPROTO_IPV6:
 393                 return do_del_ioctl("sit0", &p);
 394         default:
 395                 return do_del_ioctl(p.name, &p);
 396         }
 397         return -1;
 398 }
 399
 400 void print_tunnel(struct ip_tunnel_parm *p)
 401 {
 402         char s1[1024];
 403         char s2[1024];
 404         char s3[64];
 405         char s4[64];
 406
 407         inet_ntop(AF_INET, &p->i_key, s3, sizeof(s3));
 408         inet_ntop(AF_INET, &p->o_key, s4, sizeof(s4));
 409
 410         /* Do not use format_host() for local addr,
 411          * symbolic name will not be useful.
 412          */
 413         printf("%s: %s/ip  remote %s  local %s ",
 414                p->name,
 415                p->iph.protocol == IPPROTO_IPIP ? "ip" :
 416                (p->iph.protocol == IPPROTO_GRE ? "gre" :
 417                 (p->iph.protocol == IPPROTO_IPV6 ? "ipv6" : "unknown")),
 418                p->iph.daddr ? format_host(AF_INET, 4, &p->iph.daddr, s1, sizeof(s1))  : "any",
 419                p->iph.saddr ? rt_addr_n2a(AF_INET, 4, &p->iph.saddr, s2, sizeof(s2)) : "any");
 420
 421         if (p->link) {
 422                 char *n = do_ioctl_get_ifname(p->link);
 423                 if (n)
 424                         printf(" dev %s ", n);
 425         }
 426
 427         if (p->iph.ttl)
 428                 printf(" ttl %d ", p->iph.ttl);
 429         else
 430                 printf(" ttl inherit ");
 431
 432         if (p->iph.tos) {
 433                 SPRINT_BUF(b1);
 434                 printf(" tos");
 435                 if (p->iph.tos&1)
 436                         printf(" inherit");
 437                 if (p->iph.tos&~1)
 438                         printf("%c%s ", p->iph.tos&1 ? '/' : ' ',
 439                                rtnl_dsfield_n2a(p->iph.tos&~1, b1, sizeof(b1)));
 440         }
 441
 442         if (!(p->iph.frag_off&htons(IP_DF)))
 443                 printf(" nopmtudisc");
 444
 445         if ((p->i_flags&GRE_KEY) && (p->o_flags&GRE_KEY) && p->o_key == p->i_key)
 446                 printf(" key %s", s3);
 447         else if ((p->i_flags|p->o_flags)&GRE_KEY) {
 448                 if (p->i_flags&GRE_KEY)
 449                         printf(" ikey %s ", s3);
 450                 if (p->o_flags&GRE_KEY)
 451                         printf(" okey %s ", s4);
 452         }
 453
 454         if (p->i_flags&GRE_SEQ)
 455                 printf("%s  Drop packets out of sequence.\n", _SL_);
 456         if (p->i_flags&GRE_CSUM)
 457                 printf("%s  Checksum in received packet is required.", _SL_);
 458         if (p->o_flags&GRE_SEQ)
 459                 printf("%s  Sequence packets on output.", _SL_);
 460         if (p->o_flags&GRE_CSUM)
 461                 printf("%s  Checksum output packets.", _SL_);
 462 }
 463
 464 static int do_tunnels_list(struct ip_tunnel_parm *p)
 465 {
 466         char name[IFNAMSIZ];
 467         unsigned long  rx_bytes, rx_packets, rx_errs, rx_drops,
 468         rx_fifo, rx_frame,
 469         tx_bytes, tx_packets, tx_errs, tx_drops,
 470         tx_fifo, tx_colls, tx_carrier, rx_multi;
 471         int type;
 472         struct ip_tunnel_parm p1;
 473
 474         char buf[512];
 475         FILE *fp = fopen("/proc/net/dev", "r");
 476         if (fp == NULL) {
 477                 perror("fopen");
 478                 return -1;
 479         }
 480
 481         fgets(buf, sizeof(buf), fp);
 482         fgets(buf, sizeof(buf), fp);
 483
 484         while (fgets(buf, sizeof(buf), fp) != NULL) {
 485                 char *ptr;
 486                 buf[sizeof(buf) - 1] = 0;
 487                 if ((ptr = strchr(buf, ':')) == NULL ||
 488                     (*ptr++ = 0, sscanf(buf, "%s", name) != 1)) {
 489                         fprintf(stderr, "Wrong format of /proc/net/dev. Sorry.\n");
 490                         return -1;
 491                 }
 492                 if (sscanf(ptr, "%ld%ld%ld%ld%ld%ld%ld%*d%ld%ld%ld%ld%ld%ld%ld",
 493                            &rx_bytes, &rx_packets, &rx_errs, &rx_drops,
 494                            &rx_fifo, &rx_frame, &rx_multi,
 495                            &tx_bytes, &tx_packets, &tx_errs, &tx_drops,
 496                            &tx_fifo, &tx_colls, &tx_carrier) != 14)
 497                         continue;
 498                 if (p->name[0] && strcmp(p->name, name))
 499                         continue;
 500                 type = do_ioctl_get_iftype(name);
 501                 if (type == -1) {
 502                         fprintf(stderr, "Failed to get type of [%s]\n", name);
 503                         continue;
 504                 }
 505                 if (type != ARPHRD_TUNNEL && type != ARPHRD_IPGRE && type != ARPHRD_SIT)
 506                         continue;
 507                 memset(&p1, 0, sizeof(p1));
 508                 if (do_get_ioctl(name, &p1))
 509                         continue;
 510                 if ((p->link && p1.link != p->link) ||
 511                     (p->name[0] && strcmp(p1.name, p->name)) ||
 512                     (p->iph.daddr && p1.iph.daddr != p->iph.daddr) ||
 513                     (p->iph.saddr && p1.iph.saddr != p->iph.saddr) ||
 514                     (p->i_key && p1.i_key != p->i_key))
 515                         continue;
 516                 print_tunnel(&p1);
 517                 if (show_stats) {
 518                         printf("%s", _SL_);
 519                         printf("RX: Packets    Bytes        Errors CsumErrs OutOfSeq Mcasts%s", _SL_);
 520                         printf("    %-10ld %-12ld %-6ld %-8ld %-8ld %-8ld%s",
 521                                rx_packets, rx_bytes, rx_errs, rx_frame, rx_fifo, rx_multi, _SL_);
 522                         printf("TX: Packets    Bytes        Errors DeadLoop NoRoute  NoBufs%s", _SL_);
 523                         printf("    %-10ld %-12ld %-6ld %-8ld %-8ld %-6ld",
 524                                tx_packets, tx_bytes, tx_errs, tx_colls, tx_carrier, tx_drops);
 525                 }
 526                 printf("\n");
 527         }
 528         return 0;
 529 }
 530
 531 static int do_show(int argc, char **argv)
 532 {
 533         int err;
 534         struct ip_tunnel_parm p;
 535
 536         if (parse_args(argc, argv, SIOCGETTUNNEL, &p) < 0)
 537                 return -1;
 538
 539         switch (p.iph.protocol) {
 540         case IPPROTO_IPIP:
 541                 err = do_get_ioctl(p.name[0] ? p.name : "tunl0", &p);
 542                 break;
 543         case IPPROTO_GRE:
 544                 err = do_get_ioctl(p.name[0] ? p.name : "gre0", &p);
 545                 break;
 546         case IPPROTO_IPV6:
 547                 err = do_get_ioctl(p.name[0] ? p.name : "sit0", &p);
 548                 break;
 549         default:
 550                 do_tunnels_list(&p);
 551                 return 0;
 552         }
 553         if (err)
 554                 return -1;
 555
 556         print_tunnel(&p);
 557         printf("\n");
 558         return 0;
 559 }
 560
 561 int do_iptunnel(int argc, char **argv)
 562 {
 563         if (argc > 0) {
 564                 if (matches(*argv, "add") == 0)
 565                         return do_add(SIOCADDTUNNEL, argc-1, argv+1);
 566                 if (matches(*argv, "change") == 0)
 567                         return do_add(SIOCCHGTUNNEL, argc-1, argv+1);
 568                 if (matches(*argv, "del") == 0)
 569                         return do_del(argc-1, argv+1);
 570                 if (matches(*argv, "show") == 0 ||
 571                     matches(*argv, "lst") == 0 ||
 572                     matches(*argv, "list") == 0)
 573                         return do_show(argc-1, argv+1);
 574                 if (matches(*argv, "help") == 0)
 575                         usage();
 576         } else
 577                 return do_show(0, NULL);
 578
 579         fprintf(stderr, "Command \"%s\" is unknown, try \"ip tunnel help\".\n", *argv);
 580         exit(-1);
 581 }