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