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