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
  29 #include <linux/if_arp.h>
  30 #include <linux/if_tunnel.h>
  31
  32 #include "rt_names.h"
  33 #include "utils.h"
  34
  35 #include "libbb.h"
  36
  37 static int do_ioctl_get_ifindex(char *dev)
  38 {
  39         struct ifreq ifr;
  40         int fd;
  41
  42         strcpy(ifr.ifr_name, dev);
  43         fd = socket(AF_INET, SOCK_DGRAM, 0);
  44         if (ioctl(fd, SIOCGIFINDEX, &ifr)) {
  45                 perror_msg("ioctl");
  46                 return 0;
  47         }
  48         close(fd);
  49         return ifr.ifr_ifindex;
  50 }
  51
  52 static int do_ioctl_get_iftype(char *dev)
  53 {
  54         struct ifreq ifr;
  55         int fd;
  56
  57         strcpy(ifr.ifr_name, dev);
  58         fd = socket(AF_INET, SOCK_DGRAM, 0);
  59         if (ioctl(fd, SIOCGIFHWADDR, &ifr)) {
  60                 perror_msg("ioctl");
  61                 return -1;
  62         }
  63         close(fd);
  64         return ifr.ifr_addr.sa_family;
  65 }
  66
  67
  68 static char *do_ioctl_get_ifname(int idx)
  69 {
  70         static struct ifreq ifr;
  71         int fd;
  72
  73         ifr.ifr_ifindex = idx;
  74         fd = socket(AF_INET, SOCK_DGRAM, 0);
  75         if (ioctl(fd, SIOCGIFNAME, &ifr)) {
  76                 perror_msg("ioctl");
  77                 return NULL;
  78         }
  79         close(fd);
  80         return ifr.ifr_name;
  81 }
  82
  83
  84
  85 static int do_get_ioctl(char *basedev, struct ip_tunnel_parm *p)
  86 {
  87         struct ifreq ifr;
  88         int fd;
  89         int err;
  90
  91         strcpy(ifr.ifr_name, basedev);
  92         ifr.ifr_ifru.ifru_data = (void*)p;
  93         fd = socket(AF_INET, SOCK_DGRAM, 0);
  94         err = ioctl(fd, SIOCGETTUNNEL, &ifr);
  95         if (err) {
  96                 perror_msg("ioctl");
  97         }
  98         close(fd);
  99         return err;
 100 }
 101
 102 static int do_add_ioctl(int cmd, char *basedev, struct ip_tunnel_parm *p)
 103 {
 104         struct ifreq ifr;
 105         int fd;
 106         int err;
 107
 108         if (cmd == SIOCCHGTUNNEL && p->name[0]) {
 109                 strcpy(ifr.ifr_name, p->name);
 110         } else {
 111                 strcpy(ifr.ifr_name, basedev);
 112         }
 113         ifr.ifr_ifru.ifru_data = (void*)p;
 114         fd = socket(AF_INET, SOCK_DGRAM, 0);
 115         err = ioctl(fd, cmd, &ifr);
 116         if (err) {
 117                 perror_msg("ioctl");
 118         }
 119         close(fd);
 120         return err;
 121 }
 122
 123 static int do_del_ioctl(char *basedev, struct ip_tunnel_parm *p)
 124 {
 125         struct ifreq ifr;
 126         int fd;
 127         int err;
 128
 129         if (p->name[0]) {
 130                 strcpy(ifr.ifr_name, p->name);
 131         } else {
 132                 strcpy(ifr.ifr_name, basedev);
 133         }
 134         ifr.ifr_ifru.ifru_data = (void*)p;
 135         fd = socket(AF_INET, SOCK_DGRAM, 0);
 136         err = ioctl(fd, SIOCDELTUNNEL, &ifr);
 137         if (err) {
 138                 perror_msg("ioctl");
 139         }
 140         close(fd);
 141         return err;
 142 }
 143
 144 static int parse_args(int argc, char **argv, int cmd, struct ip_tunnel_parm *p)
 145 {
 146         int count = 0;
 147         char medium[IFNAMSIZ];
 148         memset(p, 0, sizeof(*p));
 149         memset(&medium, 0, sizeof(medium));
 150
 151         p->iph.version = 4;
 152         p->iph.ihl = 5;
 153 #ifndef IP_DF
 154 #define IP_DF           0x4000          /* Flag: "Don't Fragment"       */
 155 #endif
 156         p->iph.frag_off = htons(IP_DF);
 157
 158         while (argc > 0) {
 159                 if (strcmp(*argv, "mode") == 0) {
 160                         NEXT_ARG();
 161                         if (strcmp(*argv, "ipip") == 0 ||
 162                             strcmp(*argv, "ip/ip") == 0) {
 163                                 if (p->iph.protocol && p->iph.protocol != IPPROTO_IPIP) {
 164                                         error_msg("You managed to ask for more than one tunnel mode.");
 165                                         exit(-1);
 166                                 }
 167                                 p->iph.protocol = IPPROTO_IPIP;
 168                         } else if (strcmp(*argv, "gre") == 0 ||
 169                                    strcmp(*argv, "gre/ip") == 0) {
 170                                 if (p->iph.protocol && p->iph.protocol != IPPROTO_GRE) {
 171                                         error_msg("You managed to ask for more than one tunnel mode.");
 172                                         exit(-1);
 173                                 }
 174                                 p->iph.protocol = IPPROTO_GRE;
 175                         } else if (strcmp(*argv, "sit") == 0 ||
 176                                    strcmp(*argv, "ipv6/ip") == 0) {
 177                                 if (p->iph.protocol && p->iph.protocol != IPPROTO_IPV6) {
 178                                         error_msg("You managed to ask for more than one tunnel mode.");
 179                                         exit(-1);
 180                                 }
 181                                 p->iph.protocol = IPPROTO_IPV6;
 182                         } else {
 183                                 error_msg("Cannot guess tunnel mode.");
 184                                 exit(-1);
 185                         }
 186                 } else if (strcmp(*argv, "key") == 0) {
 187                         unsigned uval;
 188                         NEXT_ARG();
 189                         p->i_flags |= GRE_KEY;
 190                         p->o_flags |= GRE_KEY;
 191                         if (strchr(*argv, '.'))
 192                                 p->i_key = p->o_key = get_addr32(*argv);
 193                         else {
 194                                 if (get_unsigned(&uval, *argv, 0)<0) {
 195                                         error_msg("invalid value of \"key\"");
 196                                         exit(-1);
 197                                 }
 198                                 p->i_key = p->o_key = htonl(uval);
 199                         }
 200                 } else if (strcmp(*argv, "ikey") == 0) {
 201                         unsigned uval;
 202                         NEXT_ARG();
 203                         p->i_flags |= GRE_KEY;
 204                         if (strchr(*argv, '.'))
 205                                 p->o_key = get_addr32(*argv);
 206                         else {
 207                                 if (get_unsigned(&uval, *argv, 0)<0) {
 208                                         error_msg("invalid value of \"ikey\"");
 209                                         exit(-1);
 210                                 }
 211                                 p->i_key = htonl(uval);
 212                         }
 213                 } else if (strcmp(*argv, "okey") == 0) {
 214                         unsigned uval;
 215                         NEXT_ARG();
 216                         p->o_flags |= GRE_KEY;
 217                         if (strchr(*argv, '.'))
 218                                 p->o_key = get_addr32(*argv);
 219                         else {
 220                                 if (get_unsigned(&uval, *argv, 0)<0) {
 221                                         error_msg("invalid value of \"okey\"");
 222                                         exit(-1);
 223                                 }
 224                                 p->o_key = htonl(uval);
 225                         }
 226                 } else if (strcmp(*argv, "seq") == 0) {
 227                         p->i_flags |= GRE_SEQ;
 228                         p->o_flags |= GRE_SEQ;
 229                 } else if (strcmp(*argv, "iseq") == 0) {
 230                         p->i_flags |= GRE_SEQ;
 231                 } else if (strcmp(*argv, "oseq") == 0) {
 232                         p->o_flags |= GRE_SEQ;
 233                 } else if (strcmp(*argv, "csum") == 0) {
 234                         p->i_flags |= GRE_CSUM;
 235                         p->o_flags |= GRE_CSUM;
 236                 } else if (strcmp(*argv, "icsum") == 0) {
 237                         p->i_flags |= GRE_CSUM;
 238                 } else if (strcmp(*argv, "ocsum") == 0) {
 239                         p->o_flags |= GRE_CSUM;
 240                 } else if (strcmp(*argv, "nopmtudisc") == 0) {
 241                         p->iph.frag_off = 0;
 242                 } else if (strcmp(*argv, "pmtudisc") == 0) {
 243                         p->iph.frag_off = htons(IP_DF);
 244                 } else if (strcmp(*argv, "remote") == 0) {
 245                         NEXT_ARG();
 246                         if (strcmp(*argv, "any"))
 247                                 p->iph.daddr = get_addr32(*argv);
 248                 } else if (strcmp(*argv, "local") == 0) {
 249                         NEXT_ARG();
 250                         if (strcmp(*argv, "any"))
 251                                 p->iph.saddr = get_addr32(*argv);
 252                 } else if (strcmp(*argv, "dev") == 0) {
 253                         NEXT_ARG();
 254                         strncpy(medium, *argv, IFNAMSIZ-1);
 255                 } else if (strcmp(*argv, "ttl") == 0) {
 256                         unsigned uval;
 257                         NEXT_ARG();
 258                         if (strcmp(*argv, "inherit") != 0) {
 259                                 if (get_unsigned(&uval, *argv, 0))
 260                                         invarg("invalid TTL\n", *argv);
 261                                 if (uval > 255)
 262                                         invarg("TTL must be <=255\n", *argv);
 263                                 p->iph.ttl = uval;
 264                         }
 265                 } else if (strcmp(*argv, "tos") == 0 ||
 266                            matches(*argv, "dsfield") == 0) {
 267                         __u32 uval;
 268                         NEXT_ARG();
 269                         if (strcmp(*argv, "inherit") != 0) {
 270                                 if (rtnl_dsfield_a2n(&uval, *argv))
 271                                         invarg("bad TOS value", *argv);
 272                                 p->iph.tos = uval;
 273                         } else
 274                                 p->iph.tos = 1;
 275                 } else {
 276                         if (strcmp(*argv, "name") == 0) {
 277                                 NEXT_ARG();
 278                         }
 279                         if (p->name[0])
 280                                 duparg2("name", *argv);
 281                         strncpy(p->name, *argv, IFNAMSIZ);
 282                         if (cmd == SIOCCHGTUNNEL && count == 0) {
 283                                 struct ip_tunnel_parm old_p;
 284                                 memset(&old_p, 0, sizeof(old_p));
 285                                 if (do_get_ioctl(*argv, &old_p))
 286                                         return -1;
 287                                 *p = old_p;
 288                         }
 289                 }
 290                 count++;
 291                 argc--; argv++;
 292         }
 293
 294
 295         if (p->iph.protocol == 0) {
 296                 if (memcmp(p->name, "gre", 3) == 0)
 297                         p->iph.protocol = IPPROTO_GRE;
 298                 else if (memcmp(p->name, "ipip", 4) == 0)
 299                         p->iph.protocol = IPPROTO_IPIP;
 300                 else if (memcmp(p->name, "sit", 3) == 0)
 301                         p->iph.protocol = IPPROTO_IPV6;
 302         }
 303
 304         if (p->iph.protocol == IPPROTO_IPIP || p->iph.protocol == IPPROTO_IPV6) {
 305                 if ((p->i_flags & GRE_KEY) || (p->o_flags & GRE_KEY)) {
 306                         error_msg("Keys are not allowed with ipip and sit.");
 307                         return -1;
 308                 }
 309         }
 310
 311         if (medium[0]) {
 312                 p->link = do_ioctl_get_ifindex(medium);
 313                 if (p->link == 0)
 314                         return -1;
 315         }
 316
 317         if (p->i_key == 0 && IN_MULTICAST(ntohl(p->iph.daddr))) {
 318                 p->i_key = p->iph.daddr;
 319                 p->i_flags |= GRE_KEY;
 320         }
 321         if (p->o_key == 0 && IN_MULTICAST(ntohl(p->iph.daddr))) {
 322                 p->o_key = p->iph.daddr;
 323                 p->o_flags |= GRE_KEY;
 324         }
 325         if (IN_MULTICAST(ntohl(p->iph.daddr)) && !p->iph.saddr) {
 326                 error_msg("Broadcast tunnel requires a source address.");
 327                 return -1;
 328         }
 329         return 0;
 330 }
 331
 332
 333 static int do_add(int cmd, int argc, char **argv)
 334 {
 335         struct ip_tunnel_parm p;
 336
 337         if (parse_args(argc, argv, cmd, &p) < 0)
 338                 return -1;
 339
 340         if (p.iph.ttl && p.iph.frag_off == 0) {
 341                 error_msg("ttl != 0 and noptmudisc are incompatible");
 342                 return -1;
 343         }
 344
 345         switch (p.iph.protocol) {
 346         case IPPROTO_IPIP:
 347                 return do_add_ioctl(cmd, "tunl0", &p);
 348         case IPPROTO_GRE:
 349                 return do_add_ioctl(cmd, "gre0", &p);
 350         case IPPROTO_IPV6:
 351                 return do_add_ioctl(cmd, "sit0", &p);
 352         default:
 353                 error_msg("cannot determine tunnel mode (ipip, gre or sit)");
 354                 return -1;
 355         }
 356         return -1;
 357 }
 358
 359 int do_del(int argc, char **argv)
 360 {
 361         struct ip_tunnel_parm p;
 362
 363         if (parse_args(argc, argv, SIOCDELTUNNEL, &p) < 0)
 364                 return -1;
 365
 366         switch (p.iph.protocol) {
 367         case IPPROTO_IPIP:
 368                 return do_del_ioctl("tunl0", &p);
 369         case IPPROTO_GRE:
 370                 return do_del_ioctl("gre0", &p);
 371         case IPPROTO_IPV6:
 372                 return do_del_ioctl("sit0", &p);
 373         default:
 374                 return do_del_ioctl(p.name, &p);
 375         }
 376         return -1;
 377 }
 378
 379 void print_tunnel(struct ip_tunnel_parm *p)
 380 {
 381         char s1[256];
 382         char s2[256];
 383         char s3[64];
 384         char s4[64];
 385
 386         format_host(AF_INET, 4, &p->iph.daddr, s1, sizeof(s1));
 387         format_host(AF_INET, 4, &p->iph.saddr, s2, sizeof(s2));
 388         inet_ntop(AF_INET, &p->i_key, s3, sizeof(s3));
 389         inet_ntop(AF_INET, &p->o_key, s4, sizeof(s4));
 390
 391         printf("%s: %s/ip  remote %s  local %s ",
 392                p->name,
 393                p->iph.protocol == IPPROTO_IPIP ? "ip" :
 394                (p->iph.protocol == IPPROTO_GRE ? "gre" :
 395                 (p->iph.protocol == IPPROTO_IPV6 ? "ipv6" : "unknown")),
 396                p->iph.daddr ? s1 : "any", p->iph.saddr ? s2 : "any");
 397         if (p->link) {
 398                 char *n = do_ioctl_get_ifname(p->link);
 399                 if (n)
 400                         printf(" dev %s ", n);
 401         }
 402         if (p->iph.ttl)
 403                 printf(" ttl %d ", p->iph.ttl);
 404         else
 405                 printf(" ttl inherit ");
 406         if (p->iph.tos) {
 407                 SPRINT_BUF(b1);
 408                 printf(" tos");
 409                 if (p->iph.tos&1)
 410                         printf(" inherit");
 411                 if (p->iph.tos&~1)
 412                         printf("%c%s ", p->iph.tos&1 ? '/' : ' ',
 413                                rtnl_dsfield_n2a(p->iph.tos&~1, b1, sizeof(b1)));
 414         }
 415         if (!(p->iph.frag_off&htons(IP_DF)))
 416                 printf(" nopmtudisc");
 417
 418         if ((p->i_flags&GRE_KEY) && (p->o_flags&GRE_KEY) && p->o_key == p->i_key)
 419                 printf(" key %s", s3);
 420         else if ((p->i_flags|p->o_flags)&GRE_KEY) {
 421                 if (p->i_flags&GRE_KEY)
 422                         printf(" ikey %s ", s3);
 423                 if (p->o_flags&GRE_KEY)
 424                         printf(" okey %s ", s4);
 425         }
 426
 427         if (p->i_flags&GRE_SEQ)
 428                 printf("%s  Drop packets out of sequence.\n", _SL_);
 429         if (p->i_flags&GRE_CSUM)
 430                 printf("%s  Checksum in received packet is required.", _SL_);
 431         if (p->o_flags&GRE_SEQ)
 432                 printf("%s  Sequence packets on output.", _SL_);
 433         if (p->o_flags&GRE_CSUM)
 434                 printf("%s  Checksum output packets.", _SL_);
 435 }
 436
 437 static int do_tunnels_list(struct ip_tunnel_parm *p)
 438 {
 439         char name[IFNAMSIZ];
 440         unsigned long  rx_bytes, rx_packets, rx_errs, rx_drops,
 441         rx_fifo, rx_frame,
 442         tx_bytes, tx_packets, tx_errs, tx_drops,
 443         tx_fifo, tx_colls, tx_carrier, rx_multi;
 444         int type;
 445         struct ip_tunnel_parm p1;
 446
 447         char buf[512];
 448         FILE *fp = fopen("/proc/net/dev", "r");
 449         if (fp == NULL) {
 450                 perror("fopen");
 451                 return -1;
 452         }
 453
 454         fgets(buf, sizeof(buf), fp);
 455         fgets(buf, sizeof(buf), fp);
 456
 457         while (fgets(buf, sizeof(buf), fp) != NULL) {
 458                 char *ptr;
 459                 buf[sizeof(buf) - 1] = 0;
 460                 if ((ptr = strchr(buf, ':')) == NULL ||
 461                     (*ptr++ = 0, sscanf(buf, "%s", name) != 1)) {
 462                         error_msg("Wrong format of /proc/net/dev. Sorry.");
 463                         return -1;
 464                 }
 465                 if (sscanf(ptr, "%ld%ld%ld%ld%ld%ld%ld%*d%ld%ld%ld%ld%ld%ld%ld",
 466                            &rx_bytes, &rx_packets, &rx_errs, &rx_drops,
 467                            &rx_fifo, &rx_frame, &rx_multi,
 468                            &tx_bytes, &tx_packets, &tx_errs, &tx_drops,
 469                            &tx_fifo, &tx_colls, &tx_carrier) != 14)
 470                         continue;
 471                 if (p->name[0] && strcmp(p->name, name))
 472                         continue;
 473                 type = do_ioctl_get_iftype(name);
 474                 if (type == -1) {
 475                         error_msg("Failed to get type of [%s]", name);
 476                         continue;
 477                 }
 478                 if (type != ARPHRD_TUNNEL && type != ARPHRD_IPGRE && type != ARPHRD_SIT)
 479                         continue;
 480                 memset(&p1, 0, sizeof(p1));
 481                 if (do_get_ioctl(name, &p1))
 482                         continue;
 483                 if ((p->link && p1.link != p->link) ||
 484                     (p->name[0] && strcmp(p1.name, p->name)) ||
 485                     (p->iph.daddr && p1.iph.daddr != p->iph.daddr) ||
 486                     (p->iph.saddr && p1.iph.saddr != p->iph.saddr) ||
 487                     (p->i_key && p1.i_key != p->i_key))
 488                         continue;
 489                 print_tunnel(&p1);
 490                 printf("\n");
 491         }
 492         return 0;
 493 }
 494
 495 static int do_show(int argc, char **argv)
 496 {
 497         int err;
 498         struct ip_tunnel_parm p;
 499
 500         if (parse_args(argc, argv, SIOCGETTUNNEL, &p) < 0)
 501                 return -1;
 502
 503         switch (p.iph.protocol) {
 504         case IPPROTO_IPIP:
 505                 err = do_get_ioctl(p.name[0] ? p.name : "tunl0", &p);
 506                 break;
 507         case IPPROTO_GRE:
 508                 err = do_get_ioctl(p.name[0] ? p.name : "gre0", &p);
 509                 break;
 510         case IPPROTO_IPV6:
 511                 err = do_get_ioctl(p.name[0] ? p.name : "sit0", &p);
 512                 break;
 513         default:
 514                 do_tunnels_list(&p);
 515                 return 0;
 516         }
 517         if (err)
 518                 return -1;
 519
 520         print_tunnel(&p);
 521         printf("\n");
 522         return 0;
 523 }
 524
 525 int do_iptunnel(int argc, char **argv)
 526 {
 527         if (argc > 0) {
 528                 if (matches(*argv, "add") == 0)
 529                         return do_add(SIOCADDTUNNEL, argc-1, argv+1);
 530                 if (matches(*argv, "change") == 0)
 531                         return do_add(SIOCCHGTUNNEL, argc-1, argv+1);
 532                 if (matches(*argv, "del") == 0)
 533                         return do_del(argc-1, argv+1);
 534                 if (matches(*argv, "show") == 0 ||
 535                     matches(*argv, "lst") == 0 ||
 536                     matches(*argv, "list") == 0)
 537                         return do_show(argc-1, argv+1);
 538         } else
 539                 return do_show(0, NULL);
 540
 541         error_msg("Command \"%s\" is unknown, try \"ip tunnel help\".", *argv);
 542         exit(-1);
 543 }