networking/libiproute/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 <sys/socket.h>
  20 #include <sys/ioctl.h>
  21
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <unistd.h>
  25
  26 #include <arpa/inet.h>
  27 #include <netinet/ip.h>
  28 #include <netinet/in.h>
  29
  30 #include <net/if.h>
  31 #include <net/if_arp.h>
  32
  33 #include <asm/types.h>
  34 #define __constant_htons htons
  35 #include <linux/if_tunnel.h>
  36
  37 #include "rt_names.h"
  38 #include "utils.h"
  39 #include "ip_common.h"
  40
  41 #include "libbb.h"
  42
  43 static int do_ioctl_get_ifindex(char *dev)
  44 {
  45         struct ifreq ifr;
  46         int fd;
  47
  48         strcpy(ifr.ifr_name, dev);
  49         fd = socket(AF_INET, SOCK_DGRAM, 0);
  50         if (ioctl(fd, SIOCGIFINDEX, &ifr)) {
  51                 bb_perror_msg("ioctl");
  52                 return 0;
  53         }
  54         close(fd);
  55         return ifr.ifr_ifindex;
  56 }
  57
  58 static int do_ioctl_get_iftype(char *dev)
  59 {
  60         struct ifreq ifr;
  61         int fd;
  62
  63         strcpy(ifr.ifr_name, dev);
  64         fd = socket(AF_INET, SOCK_DGRAM, 0);
  65         if (ioctl(fd, SIOCGIFHWADDR, &ifr)) {
  66                 bb_perror_msg("ioctl");
  67                 return -1;
  68         }
  69         close(fd);
  70         return ifr.ifr_addr.sa_family;
  71 }
  72
  73
  74 static char *do_ioctl_get_ifname(int idx)
  75 {
  76         static struct ifreq ifr;
  77         int fd;
  78
  79         ifr.ifr_ifindex = idx;
  80         fd = socket(AF_INET, SOCK_DGRAM, 0);
  81         if (ioctl(fd, SIOCGIFNAME, &ifr)) {
  82                 bb_perror_msg("ioctl");
  83                 return NULL;
  84         }
  85         close(fd);
  86         return ifr.ifr_name;
  87 }
  88
  89
  90
  91 static int do_get_ioctl(char *basedev, struct ip_tunnel_parm *p)
  92 {
  93         struct ifreq ifr;
  94         int fd;
  95         int err;
  96
  97         strcpy(ifr.ifr_name, basedev);
  98         ifr.ifr_ifru.ifru_data = (void*)p;
  99         fd = socket(AF_INET, SOCK_DGRAM, 0);
 100         err = ioctl(fd, SIOCGETTUNNEL, &ifr);
 101         if (err) {
 102                 bb_perror_msg("ioctl");
 103         }
 104         close(fd);
 105         return err;
 106 }
 107
 108 static int do_add_ioctl(int cmd, char *basedev, struct ip_tunnel_parm *p)
 109 {
 110         struct ifreq ifr;
 111         int fd;
 112         int err;
 113
 114         if (cmd == SIOCCHGTUNNEL && p->name[0]) {
 115                 strcpy(ifr.ifr_name, p->name);
 116         } else {
 117                 strcpy(ifr.ifr_name, basedev);
 118         }
 119         ifr.ifr_ifru.ifru_data = (void*)p;
 120         fd = socket(AF_INET, SOCK_DGRAM, 0);
 121         err = ioctl(fd, cmd, &ifr);
 122         if (err) {
 123                 bb_perror_msg("ioctl");
 124         }
 125         close(fd);
 126         return err;
 127 }
 128
 129 static int do_del_ioctl(char *basedev, struct ip_tunnel_parm *p)
 130 {
 131         struct ifreq ifr;
 132         int fd;
 133         int err;
 134
 135         if (p->name[0]) {
 136                 strcpy(ifr.ifr_name, p->name);
 137         } else {
 138                 strcpy(ifr.ifr_name, basedev);
 139         }
 140         ifr.ifr_ifru.ifru_data = (void*)p;
 141         fd = socket(AF_INET, SOCK_DGRAM, 0);
 142         err = ioctl(fd, SIOCDELTUNNEL, &ifr);
 143         if (err) {
 144                 bb_perror_msg("ioctl");
 145         }
 146         close(fd);
 147         return err;
 148 }
 149
 150 static int parse_args(int argc, char **argv, int cmd, struct ip_tunnel_parm *p)
 151 {
 152         int count = 0;
 153         char medium[IFNAMSIZ];
 154         memset(p, 0, sizeof(*p));
 155         memset(&medium, 0, sizeof(medium));
 156
 157         p->iph.version = 4;
 158         p->iph.ihl = 5;
 159 #ifndef IP_DF
 160 #define IP_DF           0x4000          /* Flag: "Don't Fragment"       */
 161 #endif
 162         p->iph.frag_off = htons(IP_DF);
 163
 164         while (argc > 0) {
 165                 if (strcmp(*argv, "mode") == 0) {
 166                         NEXT_ARG();
 167                         if (strcmp(*argv, "ipip") == 0 ||
 168                             strcmp(*argv, "ip/ip") == 0) {
 169                                 if (p->iph.protocol && p->iph.protocol != IPPROTO_IPIP) {
 170                                         bb_error_msg("You managed to ask for more than one tunnel mode.");
 171                                         exit(-1);
 172                                 }
 173                                 p->iph.protocol = IPPROTO_IPIP;
 174                         } else if (strcmp(*argv, "gre") == 0 ||
 175                                    strcmp(*argv, "gre/ip") == 0) {
 176                                 if (p->iph.protocol && p->iph.protocol != IPPROTO_GRE) {
 177                                         bb_error_msg("You managed to ask for more than one tunnel mode.");
 178                                         exit(-1);
 179                                 }
 180                                 p->iph.protocol = IPPROTO_GRE;
 181                         } else if (strcmp(*argv, "sit") == 0 ||
 182                                    strcmp(*argv, "ipv6/ip") == 0) {
 183                                 if (p->iph.protocol && p->iph.protocol != IPPROTO_IPV6) {
 184                                         bb_error_msg("You managed to ask for more than one tunnel mode.");
 185                                         exit(-1);
 186                                 }
 187                                 p->iph.protocol = IPPROTO_IPV6;
 188                         } else {
 189                                 bb_error_msg("Cannot guess tunnel mode.");
 190                                 exit(-1);
 191                         }
 192                 } else if (strcmp(*argv, "key") == 0) {
 193                         unsigned uval;
 194                         NEXT_ARG();
 195                         p->i_flags |= GRE_KEY;
 196                         p->o_flags |= GRE_KEY;
 197                         if (strchr(*argv, '.'))
 198                                 p->i_key = p->o_key = get_addr32(*argv);
 199                         else {
 200                                 if (get_unsigned(&uval, *argv, 0)<0) {
 201                                         bb_error_msg("invalid value of \"key\"");
 202                                         exit(-1);
 203                                 }
 204                                 p->i_key = p->o_key = htonl(uval);
 205                         }
 206                 } else if (strcmp(*argv, "ikey") == 0) {
 207                         unsigned uval;
 208                         NEXT_ARG();
 209                         p->i_flags |= GRE_KEY;
 210                         if (strchr(*argv, '.'))
 211                                 p->o_key = get_addr32(*argv);
 212                         else {
 213                                 if (get_unsigned(&uval, *argv, 0)<0) {
 214                                         bb_error_msg("invalid value of \"ikey\"");
 215                                         exit(-1);
 216                                 }
 217                                 p->i_key = htonl(uval);
 218                         }
 219                 } else if (strcmp(*argv, "okey") == 0) {
 220                         unsigned uval;
 221                         NEXT_ARG();
 222                         p->o_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                                         bb_error_msg("invalid value of \"okey\"");
 228                                         exit(-1);
 229                                 }
 230                                 p->o_key = htonl(uval);
 231                         }
 232                 } else if (strcmp(*argv, "seq") == 0) {
 233                         p->i_flags |= GRE_SEQ;
 234                         p->o_flags |= GRE_SEQ;
 235                 } else if (strcmp(*argv, "iseq") == 0) {
 236                         p->i_flags |= GRE_SEQ;
 237                 } else if (strcmp(*argv, "oseq") == 0) {
 238                         p->o_flags |= GRE_SEQ;
 239                 } else if (strcmp(*argv, "csum") == 0) {
 240                         p->i_flags |= GRE_CSUM;
 241                         p->o_flags |= GRE_CSUM;
 242                 } else if (strcmp(*argv, "icsum") == 0) {
 243                         p->i_flags |= GRE_CSUM;
 244                 } else if (strcmp(*argv, "ocsum") == 0) {
 245                         p->o_flags |= GRE_CSUM;
 246                 } else if (strcmp(*argv, "nopmtudisc") == 0) {
 247                         p->iph.frag_off = 0;
 248                 } else if (strcmp(*argv, "pmtudisc") == 0) {
 249                         p->iph.frag_off = htons(IP_DF);
 250                 } else if (strcmp(*argv, "remote") == 0) {
 251                         NEXT_ARG();
 252                         if (strcmp(*argv, "any"))
 253                                 p->iph.daddr = get_addr32(*argv);
 254                 } else if (strcmp(*argv, "local") == 0) {
 255                         NEXT_ARG();
 256                         if (strcmp(*argv, "any"))
 257                                 p->iph.saddr = get_addr32(*argv);
 258                 } else if (strcmp(*argv, "dev") == 0) {
 259                         NEXT_ARG();
 260                         strncpy(medium, *argv, IFNAMSIZ-1);
 261                 } else if (strcmp(*argv, "ttl") == 0) {
 262                         unsigned uval;
 263                         NEXT_ARG();
 264                         if (strcmp(*argv, "inherit") != 0) {
 265                                 if (get_unsigned(&uval, *argv, 0))
 266                                         invarg("invalid TTL\n", *argv);
 267                                 if (uval > 255)
 268                                         invarg("TTL must be <=255\n", *argv);
 269                                 p->iph.ttl = uval;
 270                         }
 271                 } else if (strcmp(*argv, "tos") == 0 ||
 272                            matches(*argv, "dsfield") == 0) {
 273                         __u32 uval;
 274                         NEXT_ARG();
 275                         if (strcmp(*argv, "inherit") != 0) {
 276                                 if (rtnl_dsfield_a2n(&uval, *argv))
 277                                         invarg("bad TOS value", *argv);
 278                                 p->iph.tos = uval;
 279                         } else
 280                                 p->iph.tos = 1;
 281                 } else {
 282                         if (strcmp(*argv, "name") == 0) {
 283                                 NEXT_ARG();
 284                         }
 285                         if (p->name[0])
 286                                 duparg2("name", *argv);
 287                         strncpy(p->name, *argv, IFNAMSIZ);
 288                         if (cmd == SIOCCHGTUNNEL && count == 0) {
 289                                 struct ip_tunnel_parm old_p;
 290                                 memset(&old_p, 0, sizeof(old_p));
 291                                 if (do_get_ioctl(*argv, &old_p))
 292                                         return -1;
 293                                 *p = old_p;
 294                         }
 295                 }
 296                 count++;
 297                 argc--; argv++;
 298         }
 299
 300
 301         if (p->iph.protocol == 0) {
 302                 if (memcmp(p->name, "gre", 3) == 0)
 303                         p->iph.protocol = IPPROTO_GRE;
 304                 else if (memcmp(p->name, "ipip", 4) == 0)
 305                         p->iph.protocol = IPPROTO_IPIP;
 306                 else if (memcmp(p->name, "sit", 3) == 0)
 307                         p->iph.protocol = IPPROTO_IPV6;
 308         }
 309
 310         if (p->iph.protocol == IPPROTO_IPIP || p->iph.protocol == IPPROTO_IPV6) {
 311                 if ((p->i_flags & GRE_KEY) || (p->o_flags & GRE_KEY)) {
 312                         bb_error_msg("Keys are not allowed with ipip and sit.");
 313                         return -1;
 314                 }
 315         }
 316
 317         if (medium[0]) {
 318                 p->link = do_ioctl_get_ifindex(medium);
 319                 if (p->link == 0)
 320                         return -1;
 321         }
 322
 323         if (p->i_key == 0 && IN_MULTICAST(ntohl(p->iph.daddr))) {
 324                 p->i_key = p->iph.daddr;
 325                 p->i_flags |= GRE_KEY;
 326         }
 327         if (p->o_key == 0 && IN_MULTICAST(ntohl(p->iph.daddr))) {
 328                 p->o_key = p->iph.daddr;
 329                 p->o_flags |= GRE_KEY;
 330         }
 331         if (IN_MULTICAST(ntohl(p->iph.daddr)) && !p->iph.saddr) {
 332                 bb_error_msg("Broadcast tunnel requires a source address.");
 333                 return -1;
 334         }
 335         return 0;
 336 }
 337
 338
 339 static int do_add(int cmd, int argc, char **argv)
 340 {
 341         struct ip_tunnel_parm p;
 342
 343         if (parse_args(argc, argv, cmd, &p) < 0)
 344                 return -1;
 345
 346         if (p.iph.ttl && p.iph.frag_off == 0) {
 347                 bb_error_msg("ttl != 0 and noptmudisc are incompatible");
 348                 return -1;
 349         }
 350
 351         switch (p.iph.protocol) {
 352         case IPPROTO_IPIP:
 353                 return do_add_ioctl(cmd, "tunl0", &p);
 354         case IPPROTO_GRE:
 355                 return do_add_ioctl(cmd, "gre0", &p);
 356         case IPPROTO_IPV6:
 357                 return do_add_ioctl(cmd, "sit0", &p);
 358         default:
 359                 bb_error_msg("cannot determine tunnel mode (ipip, gre or sit)");
 360                 return -1;
 361         }
 362         return -1;
 363 }
 364
 365 static int do_del(int argc, char **argv)
 366 {
 367         struct ip_tunnel_parm p;
 368
 369         if (parse_args(argc, argv, SIOCDELTUNNEL, &p) < 0)
 370                 return -1;
 371
 372         switch (p.iph.protocol) {
 373         case IPPROTO_IPIP:
 374                 return do_del_ioctl("tunl0", &p);
 375         case IPPROTO_GRE:
 376                 return do_del_ioctl("gre0", &p);
 377         case IPPROTO_IPV6:
 378                 return do_del_ioctl("sit0", &p);
 379         default:
 380                 return do_del_ioctl(p.name, &p);
 381         }
 382         return -1;
 383 }
 384
 385 static void print_tunnel(struct ip_tunnel_parm *p)
 386 {
 387         char s1[256];
 388         char s2[256];
 389         char s3[64];
 390         char s4[64];
 391
 392         format_host(AF_INET, 4, &p->iph.daddr, s1, sizeof(s1));
 393         format_host(AF_INET, 4, &p->iph.saddr, s2, sizeof(s2));
 394         inet_ntop(AF_INET, &p->i_key, s3, sizeof(s3));
 395         inet_ntop(AF_INET, &p->o_key, s4, sizeof(s4));
 396
 397         printf("%s: %s/ip  remote %s  local %s ",
 398                p->name,
 399                p->iph.protocol == IPPROTO_IPIP ? "ip" :
 400                (p->iph.protocol == IPPROTO_GRE ? "gre" :
 401                 (p->iph.protocol == IPPROTO_IPV6 ? "ipv6" : "unknown")),
 402                p->iph.daddr ? s1 : "any", p->iph.saddr ? s2 : "any");
 403         if (p->link) {
 404                 char *n = do_ioctl_get_ifname(p->link);
 405                 if (n)
 406                         printf(" dev %s ", n);
 407         }
 408         if (p->iph.ttl)
 409                 printf(" ttl %d ", p->iph.ttl);
 410         else
 411                 printf(" ttl inherit ");
 412         if (p->iph.tos) {
 413                 SPRINT_BUF(b1);
 414                 printf(" tos");
 415                 if (p->iph.tos&1)
 416                         printf(" inherit");
 417                 if (p->iph.tos&~1)
 418                         printf("%c%s ", p->iph.tos&1 ? '/' : ' ',
 419                                rtnl_dsfield_n2a(p->iph.tos&~1, b1, sizeof(b1)));
 420         }
 421         if (!(p->iph.frag_off&htons(IP_DF)))
 422                 printf(" nopmtudisc");
 423
 424         if ((p->i_flags&GRE_KEY) && (p->o_flags&GRE_KEY) && p->o_key == p->i_key)
 425                 printf(" key %s", s3);
 426         else if ((p->i_flags|p->o_flags)&GRE_KEY) {
 427                 if (p->i_flags&GRE_KEY)
 428                         printf(" ikey %s ", s3);
 429                 if (p->o_flags&GRE_KEY)
 430                         printf(" okey %s ", s4);
 431         }
 432
 433         if (p->i_flags&GRE_SEQ)
 434                 printf("%s  Drop packets out of sequence.\n", _SL_);
 435         if (p->i_flags&GRE_CSUM)
 436                 printf("%s  Checksum in received packet is required.", _SL_);
 437         if (p->o_flags&GRE_SEQ)
 438                 printf("%s  Sequence packets on output.", _SL_);
 439         if (p->o_flags&GRE_CSUM)
 440                 printf("%s  Checksum output packets.", _SL_);
 441 }
 442
 443 static int do_tunnels_list(struct ip_tunnel_parm *p)
 444 {
 445         char name[IFNAMSIZ];
 446         unsigned long  rx_bytes, rx_packets, rx_errs, rx_drops,
 447         rx_fifo, rx_frame,
 448         tx_bytes, tx_packets, tx_errs, tx_drops,
 449         tx_fifo, tx_colls, tx_carrier, rx_multi;
 450         int type;
 451         struct ip_tunnel_parm p1;
 452
 453         char buf[512];
 454         FILE *fp = fopen("/proc/net/dev", "r");
 455         if (fp == NULL) {
 456                 perror("fopen");
 457                 return -1;
 458         }
 459
 460         fgets(buf, sizeof(buf), fp);
 461         fgets(buf, sizeof(buf), fp);
 462
 463         while (fgets(buf, sizeof(buf), fp) != NULL) {
 464                 char *ptr;
 465                 buf[sizeof(buf) - 1] = 0;
 466                 if ((ptr = strchr(buf, ':')) == NULL ||
 467                     (*ptr++ = 0, sscanf(buf, "%s", name) != 1)) {
 468                         bb_error_msg("Wrong format of /proc/net/dev. Sorry.");
 469                         return -1;
 470                 }
 471                 if (sscanf(ptr, "%ld%ld%ld%ld%ld%ld%ld%*d%ld%ld%ld%ld%ld%ld%ld",
 472                            &rx_bytes, &rx_packets, &rx_errs, &rx_drops,
 473                            &rx_fifo, &rx_frame, &rx_multi,
 474                            &tx_bytes, &tx_packets, &tx_errs, &tx_drops,
 475                            &tx_fifo, &tx_colls, &tx_carrier) != 14)
 476                         continue;
 477                 if (p->name[0] && strcmp(p->name, name))
 478                         continue;
 479                 type = do_ioctl_get_iftype(name);
 480                 if (type == -1) {
 481                         bb_error_msg("Failed to get type of [%s]", name);
 482                         continue;
 483                 }
 484                 if (type != ARPHRD_TUNNEL && type != ARPHRD_IPGRE && type != ARPHRD_SIT)
 485                         continue;
 486                 memset(&p1, 0, sizeof(p1));
 487                 if (do_get_ioctl(name, &p1))
 488                         continue;
 489                 if ((p->link && p1.link != p->link) ||
 490                     (p->name[0] && strcmp(p1.name, p->name)) ||
 491                     (p->iph.daddr && p1.iph.daddr != p->iph.daddr) ||
 492                     (p->iph.saddr && p1.iph.saddr != p->iph.saddr) ||
 493                     (p->i_key && p1.i_key != p->i_key))
 494                         continue;
 495                 print_tunnel(&p1);
 496                 printf("\n");
 497         }
 498         return 0;
 499 }
 500
 501 static int do_show(int argc, char **argv)
 502 {
 503         int err;
 504         struct ip_tunnel_parm p;
 505
 506         if (parse_args(argc, argv, SIOCGETTUNNEL, &p) < 0)
 507                 return -1;
 508
 509         switch (p.iph.protocol) {
 510         case IPPROTO_IPIP:
 511                 err = do_get_ioctl(p.name[0] ? p.name : "tunl0", &p);
 512                 break;
 513         case IPPROTO_GRE:
 514                 err = do_get_ioctl(p.name[0] ? p.name : "gre0", &p);
 515                 break;
 516         case IPPROTO_IPV6:
 517                 err = do_get_ioctl(p.name[0] ? p.name : "sit0", &p);
 518                 break;
 519         default:
 520                 do_tunnels_list(&p);
 521                 return 0;
 522         }
 523         if (err)
 524                 return -1;
 525
 526         print_tunnel(&p);
 527         printf("\n");
 528         return 0;
 529 }
 530
 531 int do_iptunnel(int argc, char **argv)
 532 {
 533         if (argc > 0) {
 534                 if (matches(*argv, "add") == 0)
 535                         return do_add(SIOCADDTUNNEL, argc-1, argv+1);
 536                 if (matches(*argv, "change") == 0)
 537                         return do_add(SIOCCHGTUNNEL, argc-1, argv+1);
 538                 if (matches(*argv, "del") == 0)
 539                         return do_del(argc-1, argv+1);
 540                 if (matches(*argv, "show") == 0 ||
 541                     matches(*argv, "lst") == 0 ||
 542                     matches(*argv, "list") == 0)
 543                         return do_show(argc-1, argv+1);
 544         } else
 545                 return do_show(0, NULL);
 546
 547         bb_error_msg("Command \"%s\" is unknown.", *argv);
 548         exit(-1);
 549 }