ipsec_input.c revision 274132
1/* $FreeBSD: stable/10/sys/netipsec/ipsec_input.c 274132 2014-11-05 09:23:29Z ae $ */ 2/* $OpenBSD: ipsec_input.c,v 1.63 2003/02/20 18:35:43 deraadt Exp $ */ 3/*- 4 * The authors of this code are John Ioannidis (ji@tla.org), 5 * Angelos D. Keromytis (kermit@csd.uch.gr) and 6 * Niels Provos (provos@physnet.uni-hamburg.de). 7 * 8 * This code was written by John Ioannidis for BSD/OS in Athens, Greece, 9 * in November 1995. 10 * 11 * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996, 12 * by Angelos D. Keromytis. 13 * 14 * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis 15 * and Niels Provos. 16 * 17 * Additional features in 1999 by Angelos D. Keromytis. 18 * 19 * Copyright (C) 1995, 1996, 1997, 1998, 1999 by John Ioannidis, 20 * Angelos D. Keromytis and Niels Provos. 21 * Copyright (c) 2001, Angelos D. Keromytis. 22 * 23 * Permission to use, copy, and modify this software with or without fee 24 * is hereby granted, provided that this entire notice is included in 25 * all copies of any software which is or includes a copy or 26 * modification of this software. 27 * You may use this code under the GNU public license if you so wish. Please 28 * contribute changes back to the authors under this freer than GPL license 29 * so that we may further the use of strong encryption without limitations to 30 * all. 31 * 32 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR 33 * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY 34 * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE 35 * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR 36 * PURPOSE. 37 */ 38 39/* 40 * IPsec input processing. 41 */ 42 43#include "opt_inet.h" 44#include "opt_inet6.h" 45#include "opt_ipsec.h" 46#include "opt_enc.h" 47 48#include <sys/param.h> 49#include <sys/systm.h> 50#include <sys/malloc.h> 51#include <sys/mbuf.h> 52#include <sys/domain.h> 53#include <sys/protosw.h> 54#include <sys/socket.h> 55#include <sys/errno.h> 56#include <sys/syslog.h> 57 58#include <net/if.h> 59#include <net/pfil.h> 60#include <net/route.h> 61#include <net/netisr.h> 62#include <net/vnet.h> 63 64#include <netinet/in.h> 65#include <netinet/in_systm.h> 66#include <netinet/ip.h> 67#include <netinet/ip_var.h> 68#include <netinet/in_var.h> 69 70#include <netinet/ip6.h> 71#ifdef INET6 72#include <netinet6/ip6_var.h> 73#endif 74#include <netinet/in_pcb.h> 75#ifdef INET6 76#include <netinet/icmp6.h> 77#endif 78 79#include <netipsec/ipsec.h> 80#ifdef INET6 81#include <netipsec/ipsec6.h> 82#endif 83#include <netipsec/ah_var.h> 84#include <netipsec/esp.h> 85#include <netipsec/esp_var.h> 86#include <netipsec/ipcomp_var.h> 87 88#include <netipsec/key.h> 89#include <netipsec/keydb.h> 90 91#include <netipsec/xform.h> 92#include <netinet6/ip6protosw.h> 93 94#include <machine/in_cksum.h> 95#include <machine/stdarg.h> 96 97#ifdef DEV_ENC 98#include <net/if_enc.h> 99#endif 100 101 102#define IPSEC_ISTAT(proto, name) do { \ 103 if ((proto) == IPPROTO_ESP) \ 104 ESPSTAT_INC(esps_##name); \ 105 else if ((proto) == IPPROTO_AH) \ 106 AHSTAT_INC(ahs_##name); \ 107 else \ 108 IPCOMPSTAT_INC(ipcomps_##name); \ 109} while (0) 110 111#ifdef INET 112static void ipsec4_common_ctlinput(int, struct sockaddr *, void *, int); 113#endif 114 115/* 116 * ipsec_common_input gets called when an IPsec-protected packet 117 * is received by IPv4 or IPv6. Its job is to find the right SA 118 * and call the appropriate transform. The transform callback 119 * takes care of further processing (like ingress filtering). 120 */ 121static int 122ipsec_common_input(struct mbuf *m, int skip, int protoff, int af, int sproto) 123{ 124 union sockaddr_union dst_address; 125 struct secasvar *sav; 126 u_int32_t spi; 127 int error; 128#ifdef INET 129#ifdef IPSEC_NAT_T 130 struct m_tag *tag; 131#endif 132#endif 133 134 IPSEC_ISTAT(sproto, input); 135 136 IPSEC_ASSERT(m != NULL, ("null packet")); 137 138 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH || 139 sproto == IPPROTO_IPCOMP, 140 ("unexpected security protocol %u", sproto)); 141 142 if ((sproto == IPPROTO_ESP && !V_esp_enable) || 143 (sproto == IPPROTO_AH && !V_ah_enable) || 144 (sproto == IPPROTO_IPCOMP && !V_ipcomp_enable)) { 145 m_freem(m); 146 IPSEC_ISTAT(sproto, pdrops); 147 return EOPNOTSUPP; 148 } 149 150 if (m->m_pkthdr.len - skip < 2 * sizeof (u_int32_t)) { 151 m_freem(m); 152 IPSEC_ISTAT(sproto, hdrops); 153 DPRINTF(("%s: packet too small\n", __func__)); 154 return EINVAL; 155 } 156 157 /* Retrieve the SPI from the relevant IPsec header */ 158 if (sproto == IPPROTO_ESP) 159 m_copydata(m, skip, sizeof(u_int32_t), (caddr_t) &spi); 160 else if (sproto == IPPROTO_AH) 161 m_copydata(m, skip + sizeof(u_int32_t), sizeof(u_int32_t), 162 (caddr_t) &spi); 163 else if (sproto == IPPROTO_IPCOMP) { 164 u_int16_t cpi; 165 m_copydata(m, skip + sizeof(u_int16_t), sizeof(u_int16_t), 166 (caddr_t) &cpi); 167 spi = ntohl(htons(cpi)); 168 } 169 170 /* 171 * Find the SA and (indirectly) call the appropriate 172 * kernel crypto routine. The resulting mbuf chain is a valid 173 * IP packet ready to go through input processing. 174 */ 175 bzero(&dst_address, sizeof (dst_address)); 176 dst_address.sa.sa_family = af; 177 switch (af) { 178#ifdef INET 179 case AF_INET: 180 dst_address.sin.sin_len = sizeof(struct sockaddr_in); 181 m_copydata(m, offsetof(struct ip, ip_dst), 182 sizeof(struct in_addr), 183 (caddr_t) &dst_address.sin.sin_addr); 184#ifdef IPSEC_NAT_T 185 /* Find the source port for NAT-T; see udp*_espdecap. */ 186 tag = m_tag_find(m, PACKET_TAG_IPSEC_NAT_T_PORTS, NULL); 187 if (tag != NULL) 188 dst_address.sin.sin_port = ((u_int16_t *)(tag + 1))[1]; 189#endif /* IPSEC_NAT_T */ 190 break; 191#endif /* INET */ 192#ifdef INET6 193 case AF_INET6: 194 dst_address.sin6.sin6_len = sizeof(struct sockaddr_in6); 195 m_copydata(m, offsetof(struct ip6_hdr, ip6_dst), 196 sizeof(struct in6_addr), 197 (caddr_t) &dst_address.sin6.sin6_addr); 198 break; 199#endif /* INET6 */ 200 default: 201 DPRINTF(("%s: unsupported protocol family %u\n", __func__, af)); 202 m_freem(m); 203 IPSEC_ISTAT(sproto, nopf); 204 return EPFNOSUPPORT; 205 } 206 207 /* NB: only pass dst since key_allocsa follows RFC2401 */ 208 sav = KEY_ALLOCSA(&dst_address, sproto, spi); 209 if (sav == NULL) { 210 DPRINTF(("%s: no key association found for SA %s/%08lx/%u\n", 211 __func__, ipsec_address(&dst_address), 212 (u_long) ntohl(spi), sproto)); 213 IPSEC_ISTAT(sproto, notdb); 214 m_freem(m); 215 return ENOENT; 216 } 217 218 if (sav->tdb_xform == NULL) { 219 DPRINTF(("%s: attempted to use uninitialized SA %s/%08lx/%u\n", 220 __func__, ipsec_address(&dst_address), 221 (u_long) ntohl(spi), sproto)); 222 IPSEC_ISTAT(sproto, noxform); 223 KEY_FREESAV(&sav); 224 m_freem(m); 225 return ENXIO; 226 } 227 228 /* 229 * Call appropriate transform and return -- callback takes care of 230 * everything else. 231 */ 232 error = (*sav->tdb_xform->xf_input)(m, sav, skip, protoff); 233 KEY_FREESAV(&sav); 234 return error; 235} 236 237#ifdef INET 238/* 239 * Common input handler for IPv4 AH, ESP, and IPCOMP. 240 */ 241int 242ipsec4_common_input(struct mbuf *m, ...) 243{ 244 va_list ap; 245 int off, nxt; 246 247 va_start(ap, m); 248 off = va_arg(ap, int); 249 nxt = va_arg(ap, int); 250 va_end(ap); 251 252 return ipsec_common_input(m, off, offsetof(struct ip, ip_p), 253 AF_INET, nxt); 254} 255 256void 257ah4_input(struct mbuf *m, int off) 258{ 259 ipsec4_common_input(m, off, IPPROTO_AH); 260} 261void 262ah4_ctlinput(int cmd, struct sockaddr *sa, void *v) 263{ 264 if (sa->sa_family == AF_INET && 265 sa->sa_len == sizeof(struct sockaddr_in)) 266 ipsec4_common_ctlinput(cmd, sa, v, IPPROTO_AH); 267} 268 269void 270esp4_input(struct mbuf *m, int off) 271{ 272 ipsec4_common_input(m, off, IPPROTO_ESP); 273} 274void 275esp4_ctlinput(int cmd, struct sockaddr *sa, void *v) 276{ 277 if (sa->sa_family == AF_INET && 278 sa->sa_len == sizeof(struct sockaddr_in)) 279 ipsec4_common_ctlinput(cmd, sa, v, IPPROTO_ESP); 280} 281 282void 283ipcomp4_input(struct mbuf *m, int off) 284{ 285 ipsec4_common_input(m, off, IPPROTO_IPCOMP); 286} 287 288/* 289 * IPsec input callback for INET protocols. 290 * This routine is called as the transform callback. 291 * Takes care of filtering and other sanity checks on 292 * the processed packet. 293 */ 294int 295ipsec4_common_input_cb(struct mbuf *m, struct secasvar *sav, 296 int skip, int protoff, struct m_tag *mt) 297{ 298 int prot, af, sproto, isr_prot; 299 struct ip *ip; 300 struct m_tag *mtag; 301 struct tdb_ident *tdbi; 302 struct secasindex *saidx; 303 int error; 304#ifdef INET6 305#ifdef notyet 306 char ip6buf[INET6_ADDRSTRLEN]; 307#endif 308#endif 309 310 IPSEC_ASSERT(m != NULL, ("null mbuf")); 311 IPSEC_ASSERT(sav != NULL, ("null SA")); 312 IPSEC_ASSERT(sav->sah != NULL, ("null SAH")); 313 saidx = &sav->sah->saidx; 314 af = saidx->dst.sa.sa_family; 315 IPSEC_ASSERT(af == AF_INET, ("unexpected af %u", af)); 316 sproto = saidx->proto; 317 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH || 318 sproto == IPPROTO_IPCOMP, 319 ("unexpected security protocol %u", sproto)); 320 321 /* Sanity check */ 322 if (m == NULL) { 323 DPRINTF(("%s: null mbuf", __func__)); 324 IPSEC_ISTAT(sproto, badkcr); 325 KEY_FREESAV(&sav); 326 return EINVAL; 327 } 328 329 if (skip != 0) { 330 /* 331 * Fix IPv4 header 332 * XXXGL: do we need this entire block? 333 */ 334 if (m->m_len < skip && (m = m_pullup(m, skip)) == NULL) { 335 DPRINTF(("%s: processing failed for SA %s/%08lx\n", 336 __func__, ipsec_address(&sav->sah->saidx.dst), 337 (u_long) ntohl(sav->spi))); 338 IPSEC_ISTAT(sproto, hdrops); 339 error = ENOBUFS; 340 goto bad; 341 } 342 343 ip = mtod(m, struct ip *); 344 ip->ip_len = htons(m->m_pkthdr.len); 345 ip->ip_sum = 0; 346 ip->ip_sum = in_cksum(m, ip->ip_hl << 2); 347 } else { 348 ip = mtod(m, struct ip *); 349 } 350 prot = ip->ip_p; 351 352#ifdef DEV_ENC 353 encif->if_ipackets++; 354 encif->if_ibytes += m->m_pkthdr.len; 355 356 /* 357 * Pass the mbuf to enc0 for bpf and pfil. We will filter the IPIP 358 * packet later after it has been decapsulated. 359 */ 360 ipsec_bpf(m, sav, AF_INET, ENC_IN|ENC_BEFORE); 361 362 if (prot != IPPROTO_IPIP) 363 if ((error = ipsec_filter(&m, PFIL_IN, ENC_IN|ENC_BEFORE)) != 0) 364 return (error); 365#endif /* DEV_ENC */ 366 367 /* IP-in-IP encapsulation */ 368 if (prot == IPPROTO_IPIP && 369 saidx->mode != IPSEC_MODE_TRANSPORT) { 370 371 if (m->m_pkthdr.len - skip < sizeof(struct ip)) { 372 IPSEC_ISTAT(sproto, hdrops); 373 error = EINVAL; 374 goto bad; 375 } 376 /* enc0: strip outer IPv4 header */ 377 m_striphdr(m, 0, ip->ip_hl << 2); 378 379#ifdef notyet 380 /* XXX PROXY address isn't recorded in SAH */ 381 /* 382 * Check that the inner source address is the same as 383 * the proxy address, if available. 384 */ 385 if ((saidx->proxy.sa.sa_family == AF_INET && 386 saidx->proxy.sin.sin_addr.s_addr != 387 INADDR_ANY && 388 ipn.ip_src.s_addr != 389 saidx->proxy.sin.sin_addr.s_addr) || 390 (saidx->proxy.sa.sa_family != AF_INET && 391 saidx->proxy.sa.sa_family != 0)) { 392 393 DPRINTF(("%s: inner source address %s doesn't " 394 "correspond to expected proxy source %s, " 395 "SA %s/%08lx\n", __func__, 396 inet_ntoa4(ipn.ip_src), 397 ipsp_address(saidx->proxy), 398 ipsp_address(saidx->dst), 399 (u_long) ntohl(sav->spi))); 400 401 IPSEC_ISTAT(sproto, pdrops); 402 error = EACCES; 403 goto bad; 404 } 405#endif /* notyet */ 406 } 407#ifdef INET6 408 /* IPv6-in-IP encapsulation. */ 409 if (prot == IPPROTO_IPV6 && 410 saidx->mode != IPSEC_MODE_TRANSPORT) { 411 412 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) { 413 IPSEC_ISTAT(sproto, hdrops); 414 error = EINVAL; 415 goto bad; 416 } 417 /* enc0: strip IPv4 header, keep IPv6 header only */ 418 m_striphdr(m, 0, ip->ip_hl << 2); 419#ifdef notyet 420 /* 421 * Check that the inner source address is the same as 422 * the proxy address, if available. 423 */ 424 if ((saidx->proxy.sa.sa_family == AF_INET6 && 425 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) && 426 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src, 427 &saidx->proxy.sin6.sin6_addr)) || 428 (saidx->proxy.sa.sa_family != AF_INET6 && 429 saidx->proxy.sa.sa_family != 0)) { 430 431 DPRINTF(("%s: inner source address %s doesn't " 432 "correspond to expected proxy source %s, " 433 "SA %s/%08lx\n", __func__, 434 ip6_sprintf(ip6buf, &ip6n.ip6_src), 435 ipsec_address(&saidx->proxy), 436 ipsec_address(&saidx->dst), 437 (u_long) ntohl(sav->spi))); 438 439 IPSEC_ISTAT(sproto, pdrops); 440 error = EACCES; 441 goto bad; 442 } 443#endif /* notyet */ 444 } 445#endif /* INET6 */ 446 447 /* 448 * Record what we've done to the packet (under what SA it was 449 * processed). If we've been passed an mtag, it means the packet 450 * was already processed by an ethernet/crypto combo card and 451 * thus has a tag attached with all the right information, but 452 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to 453 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type. 454 */ 455 if (mt == NULL && sproto != IPPROTO_IPCOMP) { 456 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE, 457 sizeof(struct tdb_ident), M_NOWAIT); 458 if (mtag == NULL) { 459 DPRINTF(("%s: failed to get tag\n", __func__)); 460 IPSEC_ISTAT(sproto, hdrops); 461 error = ENOMEM; 462 goto bad; 463 } 464 465 tdbi = (struct tdb_ident *)(mtag + 1); 466 bcopy(&saidx->dst, &tdbi->dst, saidx->dst.sa.sa_len); 467 tdbi->proto = sproto; 468 tdbi->spi = sav->spi; 469 /* Cache those two for enc(4) in xform_ipip. */ 470 tdbi->alg_auth = sav->alg_auth; 471 tdbi->alg_enc = sav->alg_enc; 472 473 m_tag_prepend(m, mtag); 474 } else if (mt != NULL) { 475 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE; 476 /* XXX do we need to mark m_flags??? */ 477 } 478 479 key_sa_recordxfer(sav, m); /* record data transfer */ 480 481 /* 482 * In transport mode requeue decrypted mbuf back to IPv4 protocol 483 * handler. This is necessary to correctly expose rcvif. 484 */ 485 if (saidx->mode == IPSEC_MODE_TRANSPORT) 486 prot = IPPROTO_IPIP; 487#ifdef DEV_ENC 488 /* 489 * Pass the mbuf to enc0 for bpf and pfil. 490 */ 491 if (prot == IPPROTO_IPIP) 492 ipsec_bpf(m, sav, AF_INET, ENC_IN|ENC_AFTER); 493#ifdef INET6 494 if (prot == IPPROTO_IPV6) 495 ipsec_bpf(m, sav, AF_INET6, ENC_IN|ENC_AFTER); 496#endif 497 498 if ((error = ipsec_filter(&m, PFIL_IN, ENC_IN|ENC_AFTER)) != 0) 499 return (error); 500#endif /* DEV_ENC */ 501 502 /* 503 * Re-dispatch via software interrupt. 504 */ 505 506 switch (prot) { 507 case IPPROTO_IPIP: 508 isr_prot = NETISR_IP; 509 break; 510#ifdef INET6 511 case IPPROTO_IPV6: 512 isr_prot = NETISR_IPV6; 513 break; 514#endif 515 default: 516 DPRINTF(("%s: cannot handle inner ip proto %d\n", 517 __func__, prot)); 518 IPSEC_ISTAT(sproto, nopf); 519 error = EPFNOSUPPORT; 520 goto bad; 521 } 522 523 error = netisr_queue_src(isr_prot, (uintptr_t)sav->spi, m); 524 if (error) { 525 IPSEC_ISTAT(sproto, qfull); 526 DPRINTF(("%s: queue full; proto %u packet dropped\n", 527 __func__, sproto)); 528 return error; 529 } 530 return 0; 531bad: 532 m_freem(m); 533 return error; 534} 535 536void 537ipsec4_common_ctlinput(int cmd, struct sockaddr *sa, void *v, int proto) 538{ 539 /* XXX nothing just yet */ 540} 541#endif /* INET */ 542 543#ifdef INET6 544/* IPv6 AH wrapper. */ 545int 546ipsec6_common_input(struct mbuf **mp, int *offp, int proto) 547{ 548 int l = 0; 549 int protoff; 550 struct ip6_ext ip6e; 551 552 if (*offp < sizeof(struct ip6_hdr)) { 553 DPRINTF(("%s: bad offset %u\n", __func__, *offp)); 554 return IPPROTO_DONE; 555 } else if (*offp == sizeof(struct ip6_hdr)) { 556 protoff = offsetof(struct ip6_hdr, ip6_nxt); 557 } else { 558 /* Chase down the header chain... */ 559 protoff = sizeof(struct ip6_hdr); 560 561 do { 562 protoff += l; 563 m_copydata(*mp, protoff, sizeof(ip6e), 564 (caddr_t) &ip6e); 565 566 if (ip6e.ip6e_nxt == IPPROTO_AH) 567 l = (ip6e.ip6e_len + 2) << 2; 568 else 569 l = (ip6e.ip6e_len + 1) << 3; 570 IPSEC_ASSERT(l > 0, ("l went zero or negative")); 571 } while (protoff + l < *offp); 572 573 /* Malformed packet check */ 574 if (protoff + l != *offp) { 575 DPRINTF(("%s: bad packet header chain, protoff %u, " 576 "l %u, off %u\n", __func__, protoff, l, *offp)); 577 IPSEC_ISTAT(proto, hdrops); 578 m_freem(*mp); 579 *mp = NULL; 580 return IPPROTO_DONE; 581 } 582 protoff += offsetof(struct ip6_ext, ip6e_nxt); 583 } 584 (void) ipsec_common_input(*mp, *offp, protoff, AF_INET6, proto); 585 return IPPROTO_DONE; 586} 587 588/* 589 * IPsec input callback, called by the transform callback. Takes care of 590 * filtering and other sanity checks on the processed packet. 591 */ 592int 593ipsec6_common_input_cb(struct mbuf *m, struct secasvar *sav, int skip, int protoff, 594 struct m_tag *mt) 595{ 596 int prot, af, sproto; 597 struct ip6_hdr *ip6; 598 struct m_tag *mtag; 599 struct tdb_ident *tdbi; 600 struct secasindex *saidx; 601 int nxt; 602 u_int8_t nxt8; 603 int error, nest; 604#ifdef notyet 605 char ip6buf[INET6_ADDRSTRLEN]; 606#endif 607 608 IPSEC_ASSERT(m != NULL, ("null mbuf")); 609 IPSEC_ASSERT(sav != NULL, ("null SA")); 610 IPSEC_ASSERT(sav->sah != NULL, ("null SAH")); 611 saidx = &sav->sah->saidx; 612 af = saidx->dst.sa.sa_family; 613 IPSEC_ASSERT(af == AF_INET6, ("unexpected af %u", af)); 614 sproto = saidx->proto; 615 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH || 616 sproto == IPPROTO_IPCOMP, 617 ("unexpected security protocol %u", sproto)); 618 619 /* Sanity check */ 620 if (m == NULL) { 621 DPRINTF(("%s: null mbuf", __func__)); 622 IPSEC_ISTAT(sproto, badkcr); 623 error = EINVAL; 624 goto bad; 625 } 626 627 /* Fix IPv6 header */ 628 if (m->m_len < sizeof(struct ip6_hdr) && 629 (m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 630 631 DPRINTF(("%s: processing failed for SA %s/%08lx\n", 632 __func__, ipsec_address(&sav->sah->saidx.dst), 633 (u_long) ntohl(sav->spi))); 634 635 IPSEC_ISTAT(sproto, hdrops); 636 error = EACCES; 637 goto bad; 638 } 639 640 ip6 = mtod(m, struct ip6_hdr *); 641 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 642 643 /* Save protocol */ 644 prot = 0; 645 m_copydata(m, protoff, 1, (unsigned char *) &prot); 646 647#ifdef DEV_ENC 648 encif->if_ipackets++; 649 encif->if_ibytes += m->m_pkthdr.len; 650 651 /* 652 * Pass the mbuf to enc0 for bpf and pfil. We will filter the IPIP 653 * packet later after it has been decapsulated. 654 */ 655 ipsec_bpf(m, sav, AF_INET6, ENC_IN|ENC_BEFORE); 656 657 /* XXX-BZ does not make sense. */ 658 if (prot != IPPROTO_IPIP) 659 if ((error = ipsec_filter(&m, PFIL_IN, ENC_IN|ENC_BEFORE)) != 0) 660 return (error); 661#endif /* DEV_ENC */ 662 663#ifdef INET 664 /* IP-in-IP encapsulation */ 665 if (prot == IPPROTO_IPIP) { 666 if (m->m_pkthdr.len - skip < sizeof(struct ip)) { 667 IPSEC_ISTAT(sproto, hdrops); 668 error = EINVAL; 669 goto bad; 670 } 671 /* ipn will now contain the inner IPv4 header */ 672 m_striphdr(m, 0, skip); 673 skip = 0; 674#ifdef notyet 675 /* 676 * Check that the inner source address is the same as 677 * the proxy address, if available. 678 */ 679 if ((saidx->proxy.sa.sa_family == AF_INET && 680 saidx->proxy.sin.sin_addr.s_addr != INADDR_ANY && 681 ipn.ip_src.s_addr != saidx->proxy.sin.sin_addr.s_addr) || 682 (saidx->proxy.sa.sa_family != AF_INET && 683 saidx->proxy.sa.sa_family != 0)) { 684 685 DPRINTF(("%s: inner source address %s doesn't " 686 "correspond to expected proxy source %s, " 687 "SA %s/%08lx\n", __func__, 688 inet_ntoa4(ipn.ip_src), 689 ipsec_address(&saidx->proxy), 690 ipsec_address(&saidx->dst), 691 (u_long) ntohl(sav->spi))); 692 693 IPSEC_ISTAT(sproto, pdrops); 694 error = EACCES; 695 goto bad; 696 } 697#endif /* notyet */ 698 } 699#endif /* INET */ 700 /* IPv6-in-IP encapsulation */ 701 if (prot == IPPROTO_IPV6) { 702 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) { 703 IPSEC_ISTAT(sproto, hdrops); 704 error = EINVAL; 705 goto bad; 706 } 707 /* ip6n will now contain the inner IPv6 header. */ 708 m_striphdr(m, 0, skip); 709 skip = 0; 710#ifdef notyet 711 /* 712 * Check that the inner source address is the same as 713 * the proxy address, if available. 714 */ 715 if ((saidx->proxy.sa.sa_family == AF_INET6 && 716 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) && 717 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src, 718 &saidx->proxy.sin6.sin6_addr)) || 719 (saidx->proxy.sa.sa_family != AF_INET6 && 720 saidx->proxy.sa.sa_family != 0)) { 721 722 DPRINTF(("%s: inner source address %s doesn't " 723 "correspond to expected proxy source %s, " 724 "SA %s/%08lx\n", __func__, 725 ip6_sprintf(ip6buf, &ip6n.ip6_src), 726 ipsec_address(&saidx->proxy), 727 ipsec_address(&saidx->dst), 728 (u_long) ntohl(sav->spi))); 729 730 IPSEC_ISTAT(sproto, pdrops); 731 error = EACCES; 732 goto bad; 733 } 734#endif /* notyet */ 735 } 736 737 /* 738 * Record what we've done to the packet (under what SA it was 739 * processed). If we've been passed an mtag, it means the packet 740 * was already processed by an ethernet/crypto combo card and 741 * thus has a tag attached with all the right information, but 742 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to 743 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type. 744 */ 745 if (mt == NULL && sproto != IPPROTO_IPCOMP) { 746 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE, 747 sizeof(struct tdb_ident), M_NOWAIT); 748 if (mtag == NULL) { 749 DPRINTF(("%s: failed to get tag\n", __func__)); 750 IPSEC_ISTAT(sproto, hdrops); 751 error = ENOMEM; 752 goto bad; 753 } 754 755 tdbi = (struct tdb_ident *)(mtag + 1); 756 bcopy(&saidx->dst, &tdbi->dst, sizeof(union sockaddr_union)); 757 tdbi->proto = sproto; 758 tdbi->spi = sav->spi; 759 /* Cache those two for enc(4) in xform_ipip. */ 760 tdbi->alg_auth = sav->alg_auth; 761 tdbi->alg_enc = sav->alg_enc; 762 763 m_tag_prepend(m, mtag); 764 } else { 765 if (mt != NULL) 766 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE; 767 /* XXX do we need to mark m_flags??? */ 768 } 769 770 key_sa_recordxfer(sav, m); 771 772#ifdef DEV_ENC 773 /* 774 * Pass the mbuf to enc0 for bpf and pfil. 775 */ 776#ifdef INET 777 if (prot == IPPROTO_IPIP) 778 ipsec_bpf(m, sav, AF_INET, ENC_IN|ENC_AFTER); 779#endif 780 if (prot == IPPROTO_IPV6) 781 ipsec_bpf(m, sav, AF_INET6, ENC_IN|ENC_AFTER); 782 783 if ((error = ipsec_filter(&m, PFIL_IN, ENC_IN|ENC_AFTER)) != 0) 784 return (error); 785#endif /* DEV_ENC */ 786 /* Retrieve new protocol */ 787 /* We have stripped the IP6 header from the mbuf, we have to use the backuped proto value instead */ 788 nxt8 = prot; 789 790 /* 791 * See the end of ip6_input for this logic. 792 * IPPROTO_IPV[46] case will be processed just like other ones 793 */ 794 nest = 0; 795 nxt = nxt8; 796 while (nxt != IPPROTO_DONE) { 797 if (V_ip6_hdrnestlimit && (++nest > V_ip6_hdrnestlimit)) { 798 IP6STAT_INC(ip6s_toomanyhdr); 799 error = EINVAL; 800 goto bad; 801 } 802 803 /* 804 * Protection against faulty packet - there should be 805 * more sanity checks in header chain processing. 806 */ 807 if (m->m_pkthdr.len < skip) { 808 IP6STAT_INC(ip6s_tooshort); 809 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 810 error = EINVAL; 811 goto bad; 812 } 813 /* 814 * Enforce IPsec policy checking if we are seeing last header. 815 * note that we do not visit this with protocols with pcb layer 816 * code - like udp/tcp/raw ip. 817 */ 818 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 819 ipsec6_in_reject(m, NULL)) { 820 error = EINVAL; 821 goto bad; 822 } 823 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &skip, nxt); 824 } 825 return 0; 826bad: 827 if (m) 828 m_freem(m); 829 return error; 830} 831 832void 833esp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 834{ 835 struct ip6ctlparam *ip6cp = NULL; 836 struct mbuf *m = NULL; 837 struct ip6_hdr *ip6; 838 int off; 839 840 if (sa->sa_family != AF_INET6 || 841 sa->sa_len != sizeof(struct sockaddr_in6)) 842 return; 843 if ((unsigned)cmd >= PRC_NCMDS) 844 return; 845 846 /* if the parameter is from icmp6, decode it. */ 847 if (d != NULL) { 848 ip6cp = (struct ip6ctlparam *)d; 849 m = ip6cp->ip6c_m; 850 ip6 = ip6cp->ip6c_ip6; 851 off = ip6cp->ip6c_off; 852 } else { 853 m = NULL; 854 ip6 = NULL; 855 off = 0; /* calm gcc */ 856 } 857 858 if (ip6 != NULL) { 859 860 struct ip6ctlparam ip6cp1; 861 862 /* 863 * Notify the error to all possible sockets via pfctlinput2. 864 * Since the upper layer information (such as protocol type, 865 * source and destination ports) is embedded in the encrypted 866 * data and might have been cut, we can't directly call 867 * an upper layer ctlinput function. However, the pcbnotify 868 * function will consider source and destination addresses 869 * as well as the flow info value, and may be able to find 870 * some PCB that should be notified. 871 * Although pfctlinput2 will call esp6_ctlinput(), there is 872 * no possibility of an infinite loop of function calls, 873 * because we don't pass the inner IPv6 header. 874 */ 875 bzero(&ip6cp1, sizeof(ip6cp1)); 876 ip6cp1.ip6c_src = ip6cp->ip6c_src; 877 pfctlinput2(cmd, sa, (void *)&ip6cp1); 878 879 /* 880 * Then go to special cases that need ESP header information. 881 * XXX: We assume that when ip6 is non NULL, 882 * M and OFF are valid. 883 */ 884 885 if (cmd == PRC_MSGSIZE) { 886 struct secasvar *sav; 887 u_int32_t spi; 888 int valid; 889 890 /* check header length before using m_copydata */ 891 if (m->m_pkthdr.len < off + sizeof (struct esp)) 892 return; 893 m_copydata(m, off + offsetof(struct esp, esp_spi), 894 sizeof(u_int32_t), (caddr_t) &spi); 895 /* 896 * Check to see if we have a valid SA corresponding to 897 * the address in the ICMP message payload. 898 */ 899 sav = KEY_ALLOCSA((union sockaddr_union *)sa, 900 IPPROTO_ESP, spi); 901 valid = (sav != NULL); 902 if (sav) 903 KEY_FREESAV(&sav); 904 905 /* XXX Further validation? */ 906 907 /* 908 * Depending on whether the SA is "valid" and 909 * routing table size (mtudisc_{hi,lo}wat), we will: 910 * - recalcurate the new MTU and create the 911 * corresponding routing entry, or 912 * - ignore the MTU change notification. 913 */ 914 icmp6_mtudisc_update(ip6cp, valid); 915 } 916 } else { 917 /* we normally notify any pcb here */ 918 } 919} 920#endif /* INET6 */ 921