1/* vi: set sw=4 ts=4: */ 2/* 3 * iptunnel.c "ip tunnel" 4 * 5 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball. 6 * 7 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 8 * 9 * Changes: 10 * 11 * Rani Assaf <rani@magic.metawire.com> 980929: resolve addresses 12 * Rani Assaf <rani@magic.metawire.com> 980930: do not allow key for ipip/sit 13 * Phil Karn <karn@ka9q.ampr.org> 990408: "pmtudisc" flag 14 */ 15 16#include <netinet/ip.h> 17#include <net/if.h> 18#include <net/if_arp.h> 19#include <asm/types.h> 20 21#ifndef __constant_htons 22#define __constant_htons htons 23#endif 24 25// FYI: #define SIOCDEVPRIVATE 0x89F0 26 27/* From linux/if_tunnel.h. #including it proved troublesome 28 * (redefiniton errors due to name collisions in linux/ and net[inet]/) */ 29#define SIOCGETTUNNEL (SIOCDEVPRIVATE + 0) 30#define SIOCADDTUNNEL (SIOCDEVPRIVATE + 1) 31#define SIOCDELTUNNEL (SIOCDEVPRIVATE + 2) 32#define SIOCCHGTUNNEL (SIOCDEVPRIVATE + 3) 33//#define SIOCGETPRL (SIOCDEVPRIVATE + 4) 34//#define SIOCADDPRL (SIOCDEVPRIVATE + 5) 35//#define SIOCDELPRL (SIOCDEVPRIVATE + 6) 36//#define SIOCCHGPRL (SIOCDEVPRIVATE + 7) 37#define GRE_CSUM __constant_htons(0x8000) 38//#define GRE_ROUTING __constant_htons(0x4000) 39#define GRE_KEY __constant_htons(0x2000) 40#define GRE_SEQ __constant_htons(0x1000) 41//#define GRE_STRICT __constant_htons(0x0800) 42//#define GRE_REC __constant_htons(0x0700) 43//#define GRE_FLAGS __constant_htons(0x00F8) 44//#define GRE_VERSION __constant_htons(0x0007) 45struct ip_tunnel_parm { 46 char name[IFNAMSIZ]; 47 int link; 48 uint16_t i_flags; 49 uint16_t o_flags; 50 uint32_t i_key; 51 uint32_t o_key; 52 struct iphdr iph; 53}; 54/* SIT-mode i_flags */ 55//#define SIT_ISATAP 0x0001 56//struct ip_tunnel_prl { 57// uint32_t addr; 58// uint16_t flags; 59// uint16_t __reserved; 60// uint32_t datalen; 61// uint32_t __reserved2; 62// /* data follows */ 63//}; 64///* PRL flags */ 65//#define PRL_DEFAULT 0x0001 66 67#include "ip_common.h" /* #include "libbb.h" is inside */ 68#include "rt_names.h" 69#include "utils.h" 70 71 72/* Dies on error */ 73static int do_ioctl_get_ifindex(char *dev) 74{ 75 struct ifreq ifr; 76 int fd; 77 78 strncpy_IFNAMSIZ(ifr.ifr_name, dev); 79 fd = xsocket(AF_INET, SOCK_DGRAM, 0); 80 xioctl(fd, SIOCGIFINDEX, &ifr); 81 close(fd); 82 return ifr.ifr_ifindex; 83} 84 85static int do_ioctl_get_iftype(char *dev) 86{ 87 struct ifreq ifr; 88 int fd; 89 int err; 90 91 strncpy_IFNAMSIZ(ifr.ifr_name, dev); 92 fd = xsocket(AF_INET, SOCK_DGRAM, 0); 93 err = ioctl_or_warn(fd, SIOCGIFHWADDR, &ifr); 94 close(fd); 95 return err ? -1 : ifr.ifr_addr.sa_family; 96} 97 98static char *do_ioctl_get_ifname(int idx) 99{ 100 struct ifreq ifr; 101 int fd; 102 int err; 103 104 ifr.ifr_ifindex = idx; 105 fd = xsocket(AF_INET, SOCK_DGRAM, 0); 106 err = ioctl_or_warn(fd, SIOCGIFNAME, &ifr); 107 close(fd); 108 return err ? NULL : xstrndup(ifr.ifr_name, sizeof(ifr.ifr_name)); 109} 110 111static int do_get_ioctl(const char *basedev, struct ip_tunnel_parm *p) 112{ 113 struct ifreq ifr; 114 int fd; 115 int err; 116 117 strncpy_IFNAMSIZ(ifr.ifr_name, basedev); 118 ifr.ifr_ifru.ifru_data = (void*)p; 119 fd = xsocket(AF_INET, SOCK_DGRAM, 0); 120 err = ioctl_or_warn(fd, SIOCGETTUNNEL, &ifr); 121 close(fd); 122 return err; 123} 124 125/* Dies on error, otherwise returns 0 */ 126static int do_add_ioctl(int cmd, const char *basedev, struct ip_tunnel_parm *p) 127{ 128 struct ifreq ifr; 129 int fd; 130 131 if (cmd == SIOCCHGTUNNEL && p->name[0]) { 132 strncpy_IFNAMSIZ(ifr.ifr_name, p->name); 133 } else { 134 strncpy_IFNAMSIZ(ifr.ifr_name, basedev); 135 } 136 ifr.ifr_ifru.ifru_data = (void*)p; 137 fd = xsocket(AF_INET, SOCK_DGRAM, 0); 138#if ENABLE_IOCTL_HEX2STR_ERROR 139 /* #define magic will turn ioctl# into string */ 140 if (cmd == SIOCCHGTUNNEL) 141 xioctl(fd, SIOCCHGTUNNEL, &ifr); 142 else 143 xioctl(fd, SIOCADDTUNNEL, &ifr); 144#else 145 xioctl(fd, cmd, &ifr); 146#endif 147 close(fd); 148 return 0; 149} 150 151/* Dies on error, otherwise returns 0 */ 152static int do_del_ioctl(const char *basedev, struct ip_tunnel_parm *p) 153{ 154 struct ifreq ifr; 155 int fd; 156 157 if (p->name[0]) { 158 strncpy_IFNAMSIZ(ifr.ifr_name, p->name); 159 } else { 160 strncpy_IFNAMSIZ(ifr.ifr_name, basedev); 161 } 162 ifr.ifr_ifru.ifru_data = (void*)p; 163 fd = xsocket(AF_INET, SOCK_DGRAM, 0); 164 xioctl(fd, SIOCDELTUNNEL, &ifr); 165 close(fd); 166 return 0; 167} 168 169/* Dies on error */ 170static void parse_args(char **argv, int cmd, struct ip_tunnel_parm *p) 171{ 172 static const char keywords[] ALIGN1 = 173 "mode\0""ipip\0""ip/ip\0""gre\0""gre/ip\0""sit\0""ipv6/ip\0" 174 "key\0""ikey\0""okey\0""seq\0""iseq\0""oseq\0" 175 "csum\0""icsum\0""ocsum\0""nopmtudisc\0""pmtudisc\0" 176 "remote\0""any\0""local\0""dev\0" 177 "ttl\0""inherit\0""tos\0""dsfield\0" 178 "name\0"; 179 enum { 180 ARG_mode, ARG_ipip, ARG_ip_ip, ARG_gre, ARG_gre_ip, ARG_sit, ARG_ip6_ip, 181 ARG_key, ARG_ikey, ARG_okey, ARG_seq, ARG_iseq, ARG_oseq, 182 ARG_csum, ARG_icsum, ARG_ocsum, ARG_nopmtudisc, ARG_pmtudisc, 183 ARG_remote, ARG_any, ARG_local, ARG_dev, 184 ARG_ttl, ARG_inherit, ARG_tos, ARG_dsfield, 185 ARG_name 186 }; 187 int count = 0; 188 char medium[IFNAMSIZ]; 189 int key; 190 191 memset(p, 0, sizeof(*p)); 192 medium[0] = '\0'; 193 194 p->iph.version = 4; 195 p->iph.ihl = 5; 196#ifndef IP_DF 197#define IP_DF 0x4000 /* Flag: "Don't Fragment" */ 198#endif 199 p->iph.frag_off = htons(IP_DF); 200 201 while (*argv) { 202 key = index_in_strings(keywords, *argv); 203 if (key == ARG_mode) { 204 NEXT_ARG(); 205 key = index_in_strings(keywords, *argv); 206 if (key == ARG_ipip || 207 key == ARG_ip_ip 208 ) { 209 if (p->iph.protocol && p->iph.protocol != IPPROTO_IPIP) { 210 bb_error_msg_and_die("%s tunnel mode", "you managed to ask for more than one"); 211 } 212 p->iph.protocol = IPPROTO_IPIP; 213 } else if (key == ARG_gre || 214 key == ARG_gre_ip 215 ) { 216 if (p->iph.protocol && p->iph.protocol != IPPROTO_GRE) { 217 bb_error_msg_and_die("%s tunnel mode", "you managed to ask for more than one"); 218 } 219 p->iph.protocol = IPPROTO_GRE; 220 } else if (key == ARG_sit || 221 key == ARG_ip6_ip 222 ) { 223 if (p->iph.protocol && p->iph.protocol != IPPROTO_IPV6) { 224 bb_error_msg_and_die("%s tunnel mode", "you managed to ask for more than one"); 225 } 226 p->iph.protocol = IPPROTO_IPV6; 227 } else { 228 bb_error_msg_and_die("%s tunnel mode", "can't guess"); 229 } 230 } else if (key == ARG_key) { 231 unsigned uval; 232 NEXT_ARG(); 233 p->i_flags |= GRE_KEY; 234 p->o_flags |= GRE_KEY; 235 if (strchr(*argv, '.')) 236 p->i_key = p->o_key = get_addr32(*argv); 237 else { 238 uval = get_unsigned(*argv, "key"); 239 p->i_key = p->o_key = htonl(uval); 240 } 241 } else if (key == ARG_ikey) { 242 unsigned uval; 243 NEXT_ARG(); 244 p->i_flags |= GRE_KEY; 245 if (strchr(*argv, '.')) 246 p->o_key = get_addr32(*argv); 247 else { 248 uval = get_unsigned(*argv, "ikey"); 249 p->i_key = htonl(uval); 250 } 251 } else if (key == ARG_okey) { 252 unsigned uval; 253 NEXT_ARG(); 254 p->o_flags |= GRE_KEY; 255 if (strchr(*argv, '.')) 256 p->o_key = get_addr32(*argv); 257 else { 258 uval = get_unsigned(*argv, "okey"); 259 p->o_key = htonl(uval); 260 } 261 } else if (key == ARG_seq) { 262 p->i_flags |= GRE_SEQ; 263 p->o_flags |= GRE_SEQ; 264 } else if (key == ARG_iseq) { 265 p->i_flags |= GRE_SEQ; 266 } else if (key == ARG_oseq) { 267 p->o_flags |= GRE_SEQ; 268 } else if (key == ARG_csum) { 269 p->i_flags |= GRE_CSUM; 270 p->o_flags |= GRE_CSUM; 271 } else if (key == ARG_icsum) { 272 p->i_flags |= GRE_CSUM; 273 } else if (key == ARG_ocsum) { 274 p->o_flags |= GRE_CSUM; 275 } else if (key == ARG_nopmtudisc) { 276 p->iph.frag_off = 0; 277 } else if (key == ARG_pmtudisc) { 278 p->iph.frag_off = htons(IP_DF); 279 } else if (key == ARG_remote) { 280 NEXT_ARG(); 281 key = index_in_strings(keywords, *argv); 282 if (key != ARG_any) 283 p->iph.daddr = get_addr32(*argv); 284 } else if (key == ARG_local) { 285 NEXT_ARG(); 286 key = index_in_strings(keywords, *argv); 287 if (key != ARG_any) 288 p->iph.saddr = get_addr32(*argv); 289 } else if (key == ARG_dev) { 290 NEXT_ARG(); 291 strncpy_IFNAMSIZ(medium, *argv); 292 } else if (key == ARG_ttl) { 293 unsigned uval; 294 NEXT_ARG(); 295 key = index_in_strings(keywords, *argv); 296 if (key != ARG_inherit) { 297 uval = get_unsigned(*argv, "TTL"); 298 if (uval > 255) 299 invarg(*argv, "TTL must be <=255"); 300 p->iph.ttl = uval; 301 } 302 } else if (key == ARG_tos || 303 key == ARG_dsfield 304 ) { 305 uint32_t uval; 306 NEXT_ARG(); 307 key = index_in_strings(keywords, *argv); 308 if (key != ARG_inherit) { 309 if (rtnl_dsfield_a2n(&uval, *argv)) 310 invarg(*argv, "TOS"); 311 p->iph.tos = uval; 312 } else 313 p->iph.tos = 1; 314 } else { 315 if (key == ARG_name) { 316 NEXT_ARG(); 317 } 318 if (p->name[0]) 319 duparg2("name", *argv); 320 strncpy_IFNAMSIZ(p->name, *argv); 321 if (cmd == SIOCCHGTUNNEL && count == 0) { 322 struct ip_tunnel_parm old_p; 323 memset(&old_p, 0, sizeof(old_p)); 324 if (do_get_ioctl(*argv, &old_p)) 325 exit(EXIT_FAILURE); 326 *p = old_p; 327 } 328 } 329 count++; 330 argv++; 331 } 332 333 if (p->iph.protocol == 0) { 334 if (memcmp(p->name, "gre", 3) == 0) 335 p->iph.protocol = IPPROTO_GRE; 336 else if (memcmp(p->name, "ipip", 4) == 0) 337 p->iph.protocol = IPPROTO_IPIP; 338 else if (memcmp(p->name, "sit", 3) == 0) 339 p->iph.protocol = IPPROTO_IPV6; 340 } 341 342 if (p->iph.protocol == IPPROTO_IPIP || p->iph.protocol == IPPROTO_IPV6) { 343 if ((p->i_flags & GRE_KEY) || (p->o_flags & GRE_KEY)) { 344 bb_error_msg_and_die("keys are not allowed with ipip and sit"); 345 } 346 } 347 348 if (medium[0]) { 349 p->link = do_ioctl_get_ifindex(medium); 350 } 351 352 if (p->i_key == 0 && IN_MULTICAST(ntohl(p->iph.daddr))) { 353 p->i_key = p->iph.daddr; 354 p->i_flags |= GRE_KEY; 355 } 356 if (p->o_key == 0 && IN_MULTICAST(ntohl(p->iph.daddr))) { 357 p->o_key = p->iph.daddr; 358 p->o_flags |= GRE_KEY; 359 } 360 if (IN_MULTICAST(ntohl(p->iph.daddr)) && !p->iph.saddr) { 361 bb_error_msg_and_die("broadcast tunnel requires a source address"); 362 } 363} 364 365/* Return value becomes exitcode. It's okay to not return at all */ 366static int do_add(int cmd, char **argv) 367{ 368 struct ip_tunnel_parm p; 369 370 parse_args(argv, cmd, &p); 371 372 if (p.iph.ttl && p.iph.frag_off == 0) { 373 bb_error_msg_and_die("ttl != 0 and noptmudisc are incompatible"); 374 } 375 376 switch (p.iph.protocol) { 377 case IPPROTO_IPIP: 378 return do_add_ioctl(cmd, "tunl0", &p); 379 case IPPROTO_GRE: 380 return do_add_ioctl(cmd, "gre0", &p); 381 case IPPROTO_IPV6: 382 return do_add_ioctl(cmd, "sit0", &p); 383 default: 384 bb_error_msg_and_die("can't determine tunnel mode (ipip, gre or sit)"); 385 } 386} 387 388/* Return value becomes exitcode. It's okay to not return at all */ 389static int do_del(char **argv) 390{ 391 struct ip_tunnel_parm p; 392 393 parse_args(argv, SIOCDELTUNNEL, &p); 394 395 switch (p.iph.protocol) { 396 case IPPROTO_IPIP: 397 return do_del_ioctl("tunl0", &p); 398 case IPPROTO_GRE: 399 return do_del_ioctl("gre0", &p); 400 case IPPROTO_IPV6: 401 return do_del_ioctl("sit0", &p); 402 default: 403 return do_del_ioctl(p.name, &p); 404 } 405} 406 407static void print_tunnel(struct ip_tunnel_parm *p) 408{ 409 char s1[256]; 410 char s2[256]; 411 char s3[64]; 412 char s4[64]; 413 414 format_host(AF_INET, 4, &p->iph.daddr, s1, sizeof(s1)); 415 format_host(AF_INET, 4, &p->iph.saddr, s2, sizeof(s2)); 416 inet_ntop(AF_INET, &p->i_key, s3, sizeof(s3)); 417 inet_ntop(AF_INET, &p->o_key, s4, sizeof(s4)); 418 419 printf("%s: %s/ip remote %s local %s ", 420 p->name, 421 p->iph.protocol == IPPROTO_IPIP ? "ip" : 422 (p->iph.protocol == IPPROTO_GRE ? "gre" : 423 (p->iph.protocol == IPPROTO_IPV6 ? "ipv6" : "unknown")), 424 p->iph.daddr ? s1 : "any", p->iph.saddr ? s2 : "any"); 425 if (p->link) { 426 char *n = do_ioctl_get_ifname(p->link); 427 if (n) { 428 printf(" dev %s ", n); 429 free(n); 430 } 431 } 432 if (p->iph.ttl) 433 printf(" ttl %d ", p->iph.ttl); 434 else 435 printf(" ttl inherit "); 436 if (p->iph.tos) { 437 SPRINT_BUF(b1); 438 printf(" tos"); 439 if (p->iph.tos & 1) 440 printf(" inherit"); 441 if (p->iph.tos & ~1) 442 printf("%c%s ", p->iph.tos & 1 ? '/' : ' ', 443 rtnl_dsfield_n2a(p->iph.tos & ~1, b1)); 444 } 445 if (!(p->iph.frag_off & htons(IP_DF))) 446 printf(" nopmtudisc"); 447 448 if ((p->i_flags & GRE_KEY) && (p->o_flags & GRE_KEY) && p->o_key == p->i_key) 449 printf(" key %s", s3); 450 else if ((p->i_flags | p->o_flags) & GRE_KEY) { 451 if (p->i_flags & GRE_KEY) 452 printf(" ikey %s ", s3); 453 if (p->o_flags & GRE_KEY) 454 printf(" okey %s ", s4); 455 } 456 457 if (p->i_flags & GRE_SEQ) 458 printf("%c Drop packets out of sequence.\n", _SL_); 459 if (p->i_flags & GRE_CSUM) 460 printf("%c Checksum in received packet is required.", _SL_); 461 if (p->o_flags & GRE_SEQ) 462 printf("%c Sequence packets on output.", _SL_); 463 if (p->o_flags & GRE_CSUM) 464 printf("%c Checksum output packets.", _SL_); 465} 466 467static void do_tunnels_list(struct ip_tunnel_parm *p) 468{ 469 char name[IFNAMSIZ]; 470 unsigned long rx_bytes, rx_packets, rx_errs, rx_drops, 471 rx_fifo, rx_frame, 472 tx_bytes, tx_packets, tx_errs, tx_drops, 473 tx_fifo, tx_colls, tx_carrier, rx_multi; 474 int type; 475 struct ip_tunnel_parm p1; 476 char buf[512]; 477 FILE *fp = fopen_or_warn("/proc/net/dev", "r"); 478 479 if (fp == NULL) { 480 return; 481 } 482 /* skip headers */ 483 fgets(buf, sizeof(buf), fp); 484 fgets(buf, sizeof(buf), fp); 485 486 while (fgets(buf, sizeof(buf), fp) != NULL) { 487 char *ptr; 488 489 /*buf[sizeof(buf) - 1] = 0; - fgets is safe anyway */ 490 ptr = strchr(buf, ':'); 491 if (ptr == NULL || 492 (*ptr++ = 0, sscanf(buf, "%s", name) != 1) 493 ) { 494 bb_error_msg("wrong format of /proc/net/dev"); 495 return; 496 } 497 if (sscanf(ptr, "%lu%lu%lu%lu%lu%lu%lu%*d%lu%lu%lu%lu%lu%lu%lu", 498 &rx_bytes, &rx_packets, &rx_errs, &rx_drops, 499 &rx_fifo, &rx_frame, &rx_multi, 500 &tx_bytes, &tx_packets, &tx_errs, &tx_drops, 501 &tx_fifo, &tx_colls, &tx_carrier) != 14) 502 continue; 503 if (p->name[0] && strcmp(p->name, name)) 504 continue; 505 type = do_ioctl_get_iftype(name); 506 if (type == -1) { 507 bb_error_msg("can't get type of [%s]", name); 508 continue; 509 } 510 if (type != ARPHRD_TUNNEL && type != ARPHRD_IPGRE && type != ARPHRD_SIT) 511 continue; 512 memset(&p1, 0, sizeof(p1)); 513 if (do_get_ioctl(name, &p1)) 514 continue; 515 if ((p->link && p1.link != p->link) || 516 (p->name[0] && strcmp(p1.name, p->name)) || 517 (p->iph.daddr && p1.iph.daddr != p->iph.daddr) || 518 (p->iph.saddr && p1.iph.saddr != p->iph.saddr) || 519 (p->i_key && p1.i_key != p->i_key) 520 ) { 521 continue; 522 } 523 print_tunnel(&p1); 524 bb_putchar('\n'); 525 } 526} 527 528/* Return value becomes exitcode. It's okay to not return at all */ 529static int do_show(char **argv) 530{ 531 int err; 532 struct ip_tunnel_parm p; 533 534 parse_args(argv, SIOCGETTUNNEL, &p); 535 536 switch (p.iph.protocol) { 537 case IPPROTO_IPIP: 538 err = do_get_ioctl(p.name[0] ? p.name : "tunl0", &p); 539 break; 540 case IPPROTO_GRE: 541 err = do_get_ioctl(p.name[0] ? p.name : "gre0", &p); 542 break; 543 case IPPROTO_IPV6: 544 err = do_get_ioctl(p.name[0] ? p.name : "sit0", &p); 545 break; 546 default: 547 do_tunnels_list(&p); 548 return 0; 549 } 550 if (err) 551 return -1; 552 553 print_tunnel(&p); 554 bb_putchar('\n'); 555 return 0; 556} 557 558/* Return value becomes exitcode. It's okay to not return at all */ 559int do_iptunnel(char **argv) 560{ 561 static const char keywords[] ALIGN1 = 562 "add\0""change\0""delete\0""show\0""list\0""lst\0"; 563 enum { ARG_add = 0, ARG_change, ARG_del, ARG_show, ARG_list, ARG_lst }; 564 565 if (*argv) { 566 smalluint key = index_in_substrings(keywords, *argv); 567 if (key > 5) 568 bb_error_msg_and_die(bb_msg_invalid_arg, *argv, applet_name); 569 argv++; 570 if (key == ARG_add) 571 return do_add(SIOCADDTUNNEL, argv); 572 if (key == ARG_change) 573 return do_add(SIOCCHGTUNNEL, argv); 574 if (key == ARG_del) 575 return do_del(argv); 576 } 577 return do_show(argv); 578} 579