1 /* $OpenBSD: if_gif.c,v 1.57 2012/05/12 12:58:16 mpf Exp $ */ 2 /* $KAME: if_gif.c,v 1.43 2001/02/20 08:51:07 itojun Exp $ */ 3 4 /* 5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the project nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 #include <sys/param.h> 34 #include <sys/systm.h> 35 #include <sys/kernel.h> 36 #include <sys/mbuf.h> 37 #include <sys/socket.h> 38 #include <sys/sockio.h> 39 #include <sys/syslog.h> 40 41 #include <net/if.h> 42 #include <net/if_types.h> 43 #include <net/route.h> 44 #include <net/bpf.h> 45 46 #ifdef INET 47 #include <netinet/in.h> 48 #include <netinet/in_systm.h> 49 #include <netinet/in_var.h> 50 #include <netinet/in_gif.h> 51 #include <netinet/ip.h> 52 #include <netinet/ip_ether.h> 53 #include <netinet/ip_var.h> 54 #endif /* INET */ 55 56 #ifdef INET6 57 #ifndef INET 58 #include <netinet/in.h> 59 #endif 60 #include <netinet/ip6.h> 61 #include <netinet6/ip6_var.h> 62 #include <netinet6/in6_gif.h> 63 #endif /* INET6 */ 64 65 #include <net/if_gif.h> 66 67 #include "bpfilter.h" 68 #include "bridge.h" 69 70 void gifattach(int); 71 int gif_clone_create(struct if_clone *, int); 72 int gif_clone_destroy(struct ifnet *); 73 int gif_checkloop(struct ifnet *, struct mbuf *); 74 75 /* 76 * gif global variable definitions 77 */ 78 struct gif_softc_head gif_softc_list; 79 struct if_clone gif_cloner = 80 IF_CLONE_INITIALIZER("gif", gif_clone_create, gif_clone_destroy); 81 82 /* ARGSUSED */ 83 void 84 gifattach(int count) 85 { 86 LIST_INIT(&gif_softc_list); 87 if_clone_attach(&gif_cloner); 88 } 89 90 int 91 gif_clone_create(struct if_clone *ifc, int unit) 92 { 93 struct gif_softc *sc; 94 int s; 95 96 sc = malloc(sizeof(*sc), M_DEVBUF, M_NOWAIT|M_ZERO); 97 if (!sc) 98 return (ENOMEM); 99 100 snprintf(sc->gif_if.if_xname, sizeof sc->gif_if.if_xname, 101 "%s%d", ifc->ifc_name, unit); 102 sc->gif_if.if_mtu = GIF_MTU; 103 sc->gif_if.if_flags = IFF_POINTOPOINT | IFF_MULTICAST; 104 sc->gif_if.if_ioctl = gif_ioctl; 105 sc->gif_if.if_start = gif_start; 106 sc->gif_if.if_output = gif_output; 107 sc->gif_if.if_type = IFT_GIF; 108 IFQ_SET_MAXLEN(&sc->gif_if.if_snd, ifqmaxlen); 109 IFQ_SET_READY(&sc->gif_if.if_snd); 110 sc->gif_if.if_softc = sc; 111 if_attach(&sc->gif_if); 112 if_alloc_sadl(&sc->gif_if); 113 114 #if NBPFILTER > 0 115 bpfattach(&sc->gif_if.if_bpf, &sc->gif_if, DLT_LOOP, sizeof(u_int32_t)); 116 #endif 117 s = splnet(); 118 LIST_INSERT_HEAD(&gif_softc_list, sc, gif_list); 119 splx(s); 120 121 return (0); 122 } 123 124 int 125 gif_clone_destroy(struct ifnet *ifp) 126 { 127 struct gif_softc *sc = ifp->if_softc; 128 int s; 129 130 s = splnet(); 131 LIST_REMOVE(sc, gif_list); 132 splx(s); 133 134 if_detach(ifp); 135 136 if (sc->gif_psrc) 137 free((caddr_t)sc->gif_psrc, M_IFADDR); 138 sc->gif_psrc = NULL; 139 if (sc->gif_pdst) 140 free((caddr_t)sc->gif_pdst, M_IFADDR); 141 sc->gif_pdst = NULL; 142 free(sc, M_DEVBUF); 143 return (0); 144 } 145 146 void 147 gif_start(struct ifnet *ifp) 148 { 149 struct gif_softc *sc = (struct gif_softc*)ifp; 150 struct mbuf *m; 151 int s; 152 sa_family_t family; 153 154 while (1) { 155 s = splnet(); 156 IFQ_DEQUEUE(&ifp->if_snd, m); 157 splx(s); 158 159 if (m == NULL) 160 break; 161 162 /* is interface up and usable? */ 163 if ((ifp->if_flags & (IFF_OACTIVE | IFF_UP)) != IFF_UP || 164 sc->gif_psrc == NULL || sc->gif_pdst == NULL || 165 sc->gif_psrc->sa_family != sc->gif_pdst->sa_family) { 166 m_freem(m); 167 continue; 168 } 169 170 /* get tunnel address family */ 171 family = sc->gif_psrc->sa_family; 172 173 /* 174 * Check if the packet is comming via bridge and needs 175 * etherip encapsulation or not. bridge(4) directly calls 176 * the start function and bypasses the if_output function 177 * so we need to do the encap here. 178 */ 179 if (ifp->if_bridge && (m->m_flags & M_PROTO1)) { 180 int error = 0; 181 /* 182 * Remove multicast and broadcast flags or encapsulated 183 * packet ends up as multicast or broadcast packet. 184 */ 185 m->m_flags &= ~(M_BCAST|M_MCAST); 186 switch (sc->gif_psrc->sa_family) { 187 #ifdef INET 188 case AF_INET: 189 error = in_gif_output(ifp, AF_LINK, &m); 190 break; 191 #endif 192 #ifdef INET6 193 case AF_INET6: 194 error = in6_gif_output(ifp, AF_LINK, &m); 195 break; 196 #endif 197 default: 198 error = EAFNOSUPPORT; 199 m_freem(m); 200 break; 201 } 202 if (error) 203 continue; 204 if (gif_checkloop(ifp, m)) 205 continue; 206 } 207 208 #if NBPFILTER > 0 209 if (ifp->if_bpf) { 210 int offset; 211 sa_family_t family; 212 u_int8_t proto; 213 214 /* must decapsulate outer header for bpf */ 215 switch (sc->gif_psrc->sa_family) { 216 #ifdef INET 217 case AF_INET: 218 offset = sizeof(struct ip); 219 proto = mtod(m, struct ip *)->ip_p; 220 break; 221 #endif 222 #ifdef INET6 223 case AF_INET6: 224 offset = sizeof(struct ip6_hdr); 225 proto = mtod(m, struct ip6_hdr *)->ip6_nxt; 226 break; 227 #endif 228 default: 229 proto = 0; 230 break; 231 } 232 switch (proto) { 233 case IPPROTO_IPV4: 234 family = AF_INET; 235 break; 236 case IPPROTO_IPV6: 237 family = AF_INET6; 238 break; 239 case IPPROTO_ETHERIP: 240 family = AF_LINK; 241 offset += sizeof(struct etherip_header); 242 break; 243 case IPPROTO_MPLS: 244 family = AF_MPLS; 245 break; 246 default: 247 offset = 0; 248 family = sc->gif_psrc->sa_family; 249 break; 250 } 251 m->m_data += offset; 252 m->m_len -= offset; 253 m->m_pkthdr.len -= offset; 254 bpf_mtap_af(ifp->if_bpf, family, m, BPF_DIRECTION_OUT); 255 m->m_data -= offset; 256 m->m_len += offset; 257 m->m_pkthdr.len += offset; 258 } 259 #endif 260 ifp->if_opackets++; 261 262 /* XXX we should cache the outgoing route */ 263 264 switch (sc->gif_psrc->sa_family) { 265 #ifdef INET 266 case AF_INET: 267 ip_output(m, (void *)NULL, (void *)NULL, 0, 268 (void *)NULL, (void *)NULL); 269 break; 270 #endif 271 #ifdef INET6 272 case AF_INET6: 273 /* 274 * force fragmentation to minimum MTU, to avoid path 275 * MTU discovery. It is too painful to ask for resend 276 * of inner packet, to achieve path MTU discovery for 277 * encapsulated packets. 278 */ 279 ip6_output(m, 0, NULL, IPV6_MINMTU, 0, NULL, 280 NULL); 281 break; 282 #endif 283 default: 284 m_freem(m); 285 break; 286 } 287 } 288 } 289 290 int 291 gif_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 292 struct rtentry *rt) 293 { 294 struct gif_softc *sc = (struct gif_softc*)ifp; 295 int error = 0; 296 int s; 297 sa_family_t family = dst->sa_family; 298 299 if (!(ifp->if_flags & IFF_UP) || 300 sc->gif_psrc == NULL || sc->gif_pdst == NULL || 301 sc->gif_psrc->sa_family != sc->gif_pdst->sa_family) { 302 m_freem(m); 303 error = ENETDOWN; 304 goto end; 305 } 306 307 /* 308 * Remove multicast and broadcast flags or encapsulated packet 309 * ends up as multicast or broadcast packet. 310 */ 311 m->m_flags &= ~(M_BCAST|M_MCAST); 312 313 /* 314 * Encapsulate packet. Add IP or IP6 header depending on tunnel AF. 315 */ 316 switch (sc->gif_psrc->sa_family) { 317 #ifdef INET 318 case AF_INET: 319 error = in_gif_output(ifp, family, &m); 320 break; 321 #endif 322 #ifdef INET6 323 case AF_INET6: 324 error = in6_gif_output(ifp, family, &m); 325 break; 326 #endif 327 default: 328 m_freem(m); 329 error = EAFNOSUPPORT; 330 break; 331 } 332 333 if (error) 334 goto end; 335 336 if ((error = gif_checkloop(ifp, m))) 337 goto end; 338 339 /* 340 * Queue message on interface, and start output. 341 */ 342 s = splnet(); 343 IFQ_ENQUEUE(&ifp->if_snd, m, NULL, error); 344 if (error) { 345 /* mbuf is already freed */ 346 splx(s); 347 goto end; 348 } 349 ifp->if_obytes += m->m_pkthdr.len; 350 if_start(ifp); 351 splx(s); 352 353 end: 354 if (error) 355 ifp->if_oerrors++; 356 return (error); 357 } 358 359 int 360 gif_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 361 { 362 struct gif_softc *sc = (struct gif_softc*)ifp; 363 struct ifreq *ifr = (struct ifreq*)data; 364 int error = 0, size; 365 struct sockaddr *dst, *src; 366 struct sockaddr *sa; 367 int s; 368 struct gif_softc *sc2; 369 370 switch (cmd) { 371 case SIOCSIFADDR: 372 break; 373 374 case SIOCSIFDSTADDR: 375 break; 376 377 case SIOCADDMULTI: 378 case SIOCDELMULTI: 379 switch (ifr->ifr_addr.sa_family) { 380 #ifdef INET 381 case AF_INET: /* IP supports Multicast */ 382 break; 383 #endif /* INET */ 384 #ifdef INET6 385 case AF_INET6: /* IP6 supports Multicast */ 386 break; 387 #endif /* INET6 */ 388 default: /* Other protocols doesn't support Multicast */ 389 error = EAFNOSUPPORT; 390 break; 391 } 392 break; 393 394 case SIOCSIFPHYADDR: 395 #ifdef INET6 396 case SIOCSIFPHYADDR_IN6: 397 #endif /* INET6 */ 398 case SIOCSLIFPHYADDR: 399 switch (cmd) { 400 #ifdef INET 401 case SIOCSIFPHYADDR: 402 src = (struct sockaddr *) 403 &(((struct in_aliasreq *)data)->ifra_addr); 404 dst = (struct sockaddr *) 405 &(((struct in_aliasreq *)data)->ifra_dstaddr); 406 break; 407 #endif 408 #ifdef INET6 409 case SIOCSIFPHYADDR_IN6: 410 src = (struct sockaddr *) 411 &(((struct in6_aliasreq *)data)->ifra_addr); 412 dst = (struct sockaddr *) 413 &(((struct in6_aliasreq *)data)->ifra_dstaddr); 414 break; 415 #endif 416 case SIOCSLIFPHYADDR: 417 src = (struct sockaddr *) 418 &(((struct if_laddrreq *)data)->addr); 419 dst = (struct sockaddr *) 420 &(((struct if_laddrreq *)data)->dstaddr); 421 break; 422 default: 423 return (EINVAL); 424 } 425 426 /* sa_family must be equal */ 427 if (src->sa_family != dst->sa_family) 428 return (EINVAL); 429 430 /* validate sa_len */ 431 switch (src->sa_family) { 432 #ifdef INET 433 case AF_INET: 434 if (src->sa_len != sizeof(struct sockaddr_in)) 435 return (EINVAL); 436 break; 437 #endif 438 #ifdef INET6 439 case AF_INET6: 440 if (src->sa_len != sizeof(struct sockaddr_in6)) 441 return (EINVAL); 442 break; 443 #endif 444 default: 445 return (EAFNOSUPPORT); 446 } 447 switch (dst->sa_family) { 448 #ifdef INET 449 case AF_INET: 450 if (dst->sa_len != sizeof(struct sockaddr_in)) 451 return (EINVAL); 452 break; 453 #endif 454 #ifdef INET6 455 case AF_INET6: 456 if (dst->sa_len != sizeof(struct sockaddr_in6)) 457 return (EINVAL); 458 break; 459 #endif 460 default: 461 return (EAFNOSUPPORT); 462 } 463 464 /* check sa_family looks sane for the cmd */ 465 switch (cmd) { 466 case SIOCSIFPHYADDR: 467 if (src->sa_family == AF_INET) 468 break; 469 return (EAFNOSUPPORT); 470 #ifdef INET6 471 case SIOCSIFPHYADDR_IN6: 472 if (src->sa_family == AF_INET6) 473 break; 474 return (EAFNOSUPPORT); 475 #endif /* INET6 */ 476 case SIOCSLIFPHYADDR: 477 /* checks done in the above */ 478 break; 479 } 480 481 LIST_FOREACH(sc2, &gif_softc_list, gif_list) { 482 if (sc2 == sc) 483 continue; 484 if (!sc2->gif_pdst || !sc2->gif_psrc) 485 continue; 486 if (sc2->gif_pdst->sa_family != dst->sa_family || 487 sc2->gif_pdst->sa_len != dst->sa_len || 488 sc2->gif_psrc->sa_family != src->sa_family || 489 sc2->gif_psrc->sa_len != src->sa_len) 490 continue; 491 /* can't configure same pair of address onto two gifs */ 492 if (bcmp(sc2->gif_pdst, dst, dst->sa_len) == 0 && 493 bcmp(sc2->gif_psrc, src, src->sa_len) == 0) { 494 error = EADDRNOTAVAIL; 495 goto bad; 496 } 497 498 /* can't configure multiple multi-dest interfaces */ 499 #define multidest(x) \ 500 (((struct sockaddr_in *)(x))->sin_addr.s_addr == INADDR_ANY) 501 #ifdef INET6 502 #define multidest6(x) \ 503 (IN6_IS_ADDR_UNSPECIFIED(&((struct sockaddr_in6 *)(x))->sin6_addr)) 504 #endif 505 if (dst->sa_family == AF_INET && 506 multidest(dst) && multidest(sc2->gif_pdst)) { 507 error = EADDRNOTAVAIL; 508 goto bad; 509 } 510 #ifdef INET6 511 if (dst->sa_family == AF_INET6 && 512 multidest6(dst) && multidest6(sc2->gif_pdst)) { 513 error = EADDRNOTAVAIL; 514 goto bad; 515 } 516 #endif 517 } 518 519 if (sc->gif_psrc) 520 free((caddr_t)sc->gif_psrc, M_IFADDR); 521 sa = malloc(src->sa_len, M_IFADDR, M_WAITOK); 522 bcopy((caddr_t)src, (caddr_t)sa, src->sa_len); 523 sc->gif_psrc = sa; 524 525 if (sc->gif_pdst) 526 free((caddr_t)sc->gif_pdst, M_IFADDR); 527 sa = malloc(dst->sa_len, M_IFADDR, M_WAITOK); 528 bcopy((caddr_t)dst, (caddr_t)sa, dst->sa_len); 529 sc->gif_pdst = sa; 530 531 s = splnet(); 532 ifp->if_flags |= IFF_RUNNING; 533 if_up(ifp); /* send up RTM_IFINFO */ 534 splx(s); 535 536 error = 0; 537 break; 538 539 #ifdef SIOCDIFPHYADDR 540 case SIOCDIFPHYADDR: 541 if (sc->gif_psrc) { 542 free((caddr_t)sc->gif_psrc, M_IFADDR); 543 sc->gif_psrc = NULL; 544 } 545 if (sc->gif_pdst) { 546 free((caddr_t)sc->gif_pdst, M_IFADDR); 547 sc->gif_pdst = NULL; 548 } 549 /* change the IFF_{UP, RUNNING} flag as well? */ 550 break; 551 #endif 552 553 case SIOCGIFPSRCADDR: 554 #ifdef INET6 555 case SIOCGIFPSRCADDR_IN6: 556 #endif /* INET6 */ 557 if (sc->gif_psrc == NULL) { 558 error = EADDRNOTAVAIL; 559 goto bad; 560 } 561 src = sc->gif_psrc; 562 switch (cmd) { 563 #ifdef INET 564 case SIOCGIFPSRCADDR: 565 dst = &ifr->ifr_addr; 566 size = sizeof(ifr->ifr_addr); 567 break; 568 #endif /* INET */ 569 #ifdef INET6 570 case SIOCGIFPSRCADDR_IN6: 571 dst = (struct sockaddr *) 572 &(((struct in6_ifreq *)data)->ifr_addr); 573 size = sizeof(((struct in6_ifreq *)data)->ifr_addr); 574 break; 575 #endif /* INET6 */ 576 default: 577 error = EADDRNOTAVAIL; 578 goto bad; 579 } 580 if (src->sa_len > size) 581 return (EINVAL); 582 bcopy((caddr_t)src, (caddr_t)dst, src->sa_len); 583 break; 584 585 case SIOCGIFPDSTADDR: 586 #ifdef INET6 587 case SIOCGIFPDSTADDR_IN6: 588 #endif /* INET6 */ 589 if (sc->gif_pdst == NULL) { 590 error = EADDRNOTAVAIL; 591 goto bad; 592 } 593 src = sc->gif_pdst; 594 switch (cmd) { 595 #ifdef INET 596 case SIOCGIFPDSTADDR: 597 dst = &ifr->ifr_addr; 598 size = sizeof(ifr->ifr_addr); 599 break; 600 #endif /* INET */ 601 #ifdef INET6 602 case SIOCGIFPDSTADDR_IN6: 603 dst = (struct sockaddr *) 604 &(((struct in6_ifreq *)data)->ifr_addr); 605 size = sizeof(((struct in6_ifreq *)data)->ifr_addr); 606 break; 607 #endif /* INET6 */ 608 default: 609 error = EADDRNOTAVAIL; 610 goto bad; 611 } 612 if (src->sa_len > size) 613 return (EINVAL); 614 bcopy((caddr_t)src, (caddr_t)dst, src->sa_len); 615 break; 616 617 case SIOCGLIFPHYADDR: 618 if (sc->gif_psrc == NULL || sc->gif_pdst == NULL) { 619 error = EADDRNOTAVAIL; 620 goto bad; 621 } 622 623 /* copy src */ 624 src = sc->gif_psrc; 625 dst = (struct sockaddr *) 626 &(((struct if_laddrreq *)data)->addr); 627 size = sizeof(((struct if_laddrreq *)data)->addr); 628 if (src->sa_len > size) 629 return (EINVAL); 630 bcopy((caddr_t)src, (caddr_t)dst, src->sa_len); 631 632 /* copy dst */ 633 src = sc->gif_pdst; 634 dst = (struct sockaddr *) 635 &(((struct if_laddrreq *)data)->dstaddr); 636 size = sizeof(((struct if_laddrreq *)data)->dstaddr); 637 if (src->sa_len > size) 638 return (EINVAL); 639 bcopy((caddr_t)src, (caddr_t)dst, src->sa_len); 640 break; 641 642 case SIOCSIFFLAGS: 643 /* if_ioctl() takes care of it */ 644 break; 645 646 case SIOCSIFMTU: 647 if (ifr->ifr_mtu < GIF_MTU_MIN || ifr->ifr_mtu > GIF_MTU_MAX) 648 error = EINVAL; 649 else 650 ifp->if_mtu = ifr->ifr_mtu; 651 break; 652 653 case SIOCSLIFPHYRTABLE: 654 if (ifr->ifr_rdomainid < 0 || 655 ifr->ifr_rdomainid > RT_TABLEID_MAX || 656 !rtable_exists(ifr->ifr_rdomainid)) { 657 error = EINVAL; 658 break; 659 } 660 sc->gif_rtableid = ifr->ifr_rdomainid; 661 break; 662 case SIOCGLIFPHYRTABLE: 663 ifr->ifr_rdomainid = sc->gif_rtableid; 664 break; 665 default: 666 error = ENOTTY; 667 break; 668 } 669 bad: 670 return (error); 671 } 672 673 int 674 gif_checkloop(struct ifnet *ifp, struct mbuf *m) 675 { 676 struct m_tag *mtag; 677 678 /* 679 * gif may cause infinite recursion calls when misconfigured. 680 * We'll prevent this by detecting loops. 681 */ 682 for (mtag = m_tag_find(m, PACKET_TAG_GIF, NULL); mtag; 683 mtag = m_tag_find(m, PACKET_TAG_GIF, mtag)) { 684 if (!bcmp((caddr_t)(mtag + 1), &ifp, 685 sizeof(struct ifnet *))) { 686 log(LOG_NOTICE, "gif_output: " 687 "recursively called too many times\n"); 688 m_freem(m); 689 return ENETUNREACH; 690 } 691 } 692 693 mtag = m_tag_get(PACKET_TAG_GIF, sizeof(caddr_t), M_NOWAIT); 694 if (mtag == NULL) { 695 m_freem(m); 696 return ENOMEM; 697 } 698 bcopy(&ifp, mtag + 1, sizeof(caddr_t)); 699 m_tag_prepend(m, mtag); 700 return 0; 701 } 702