1 /* $OpenBSD: ipsec_input.c,v 1.63 2003/02/20 18:35:43 deraadt Exp $ */ 2 /*- 3 * The authors of this code are John Ioannidis (ji@tla.org), 4 * Angelos D. Keromytis (kermit@csd.uch.gr) and 5 * Niels Provos (provos@physnet.uni-hamburg.de). 6 * 7 * This code was written by John Ioannidis for BSD/OS in Athens, Greece, 8 * in November 1995. 9 * 10 * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996, 11 * by Angelos D. Keromytis. 12 * 13 * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis 14 * and Niels Provos. 15 * 16 * Additional features in 1999 by Angelos D. Keromytis. 17 * 18 * Copyright (C) 1995, 1996, 1997, 1998, 1999 by John Ioannidis, 19 * Angelos D. Keromytis and Niels Provos. 20 * Copyright (c) 2001, Angelos D. Keromytis. 21 * Copyright (c) 2016 Andrey V. Elsukov <ae@FreeBSD.org> 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 <sys/cdefs.h> 44 __FBSDID("$FreeBSD$"); 45 46 #include "opt_inet.h" 47 #include "opt_inet6.h" 48 #include "opt_ipsec.h" 49 50 #include <sys/param.h> 51 #include <sys/systm.h> 52 #include <sys/malloc.h> 53 #include <sys/mbuf.h> 54 #include <sys/domain.h> 55 #include <sys/protosw.h> 56 #include <sys/socket.h> 57 #include <sys/errno.h> 58 #include <sys/hhook.h> 59 #include <sys/syslog.h> 60 61 #include <net/if.h> 62 #include <net/if_var.h> 63 #include <net/if_enc.h> 64 #include <net/netisr.h> 65 #include <net/vnet.h> 66 67 #include <netinet/in.h> 68 #include <netinet/in_pcb.h> 69 #include <netinet/in_systm.h> 70 #include <netinet/ip.h> 71 #include <netinet/ip_var.h> 72 #include <netinet/ip_icmp.h> 73 #include <netinet/in_var.h> 74 #include <netinet/tcp_var.h> 75 76 #include <netinet/ip6.h> 77 #ifdef INET6 78 #include <netinet6/ip6_var.h> 79 #endif 80 #include <netinet/in_pcb.h> 81 #ifdef INET6 82 #include <netinet/icmp6.h> 83 #endif 84 85 #include <netipsec/ipsec.h> 86 #ifdef INET6 87 #include <netipsec/ipsec6.h> 88 #endif 89 #include <netipsec/ipsec_support.h> 90 #include <netipsec/ah_var.h> 91 #include <netipsec/esp.h> 92 #include <netipsec/esp_var.h> 93 #include <netipsec/ipcomp_var.h> 94 95 #include <netipsec/key.h> 96 #include <netipsec/keydb.h> 97 #include <netipsec/key_debug.h> 98 99 #include <netipsec/xform.h> 100 101 #include <machine/in_cksum.h> 102 #include <machine/stdarg.h> 103 104 #define IPSEC_ISTAT(proto, name) do { \ 105 if ((proto) == IPPROTO_ESP) \ 106 ESPSTAT_INC(esps_##name); \ 107 else if ((proto) == IPPROTO_AH) \ 108 AHSTAT_INC(ahs_##name); \ 109 else \ 110 IPCOMPSTAT_INC(ipcomps_##name); \ 111 } while (0) 112 113 /* 114 * ipsec_common_input gets called when an IPsec-protected packet 115 * is received by IPv4 or IPv6. Its job is to find the right SA 116 * and call the appropriate transform. The transform callback 117 * takes care of further processing (like ingress filtering). 118 */ 119 static int 120 ipsec_common_input(struct mbuf *m, int skip, int protoff, int af, int sproto) 121 { 122 IPSEC_DEBUG_DECLARE(char buf[IPSEC_ADDRSTRLEN]); 123 union sockaddr_union dst_address; 124 struct secasvar *sav; 125 uint32_t spi; 126 int error; 127 128 IPSEC_ISTAT(sproto, input); 129 130 IPSEC_ASSERT(m != NULL, ("null packet")); 131 132 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH || 133 sproto == IPPROTO_IPCOMP, 134 ("unexpected security protocol %u", sproto)); 135 136 if ((sproto == IPPROTO_ESP && !V_esp_enable) || 137 (sproto == IPPROTO_AH && !V_ah_enable) || 138 (sproto == IPPROTO_IPCOMP && !V_ipcomp_enable)) { 139 m_freem(m); 140 IPSEC_ISTAT(sproto, pdrops); 141 return EOPNOTSUPP; 142 } 143 144 if (m->m_pkthdr.len - skip < 2 * sizeof (u_int32_t)) { 145 m_freem(m); 146 IPSEC_ISTAT(sproto, hdrops); 147 DPRINTF(("%s: packet too small\n", __func__)); 148 return EINVAL; 149 } 150 151 /* Retrieve the SPI from the relevant IPsec header */ 152 if (sproto == IPPROTO_ESP) 153 m_copydata(m, skip, sizeof(u_int32_t), (caddr_t) &spi); 154 else if (sproto == IPPROTO_AH) 155 m_copydata(m, skip + sizeof(u_int32_t), sizeof(u_int32_t), 156 (caddr_t) &spi); 157 else if (sproto == IPPROTO_IPCOMP) { 158 u_int16_t cpi; 159 m_copydata(m, skip + sizeof(u_int16_t), sizeof(u_int16_t), 160 (caddr_t) &cpi); 161 spi = ntohl(htons(cpi)); 162 } 163 164 /* 165 * Find the SA and (indirectly) call the appropriate 166 * kernel crypto routine. The resulting mbuf chain is a valid 167 * IP packet ready to go through input processing. 168 */ 169 bzero(&dst_address, sizeof (dst_address)); 170 dst_address.sa.sa_family = af; 171 switch (af) { 172 #ifdef INET 173 case AF_INET: 174 dst_address.sin.sin_len = sizeof(struct sockaddr_in); 175 m_copydata(m, offsetof(struct ip, ip_dst), 176 sizeof(struct in_addr), 177 (caddr_t) &dst_address.sin.sin_addr); 178 break; 179 #endif /* INET */ 180 #ifdef INET6 181 case AF_INET6: 182 dst_address.sin6.sin6_len = sizeof(struct sockaddr_in6); 183 m_copydata(m, offsetof(struct ip6_hdr, ip6_dst), 184 sizeof(struct in6_addr), 185 (caddr_t) &dst_address.sin6.sin6_addr); 186 /* We keep addresses in SADB without embedded scope id */ 187 if (IN6_IS_SCOPE_LINKLOCAL(&dst_address.sin6.sin6_addr)) { 188 /* XXX: sa6_recoverscope() */ 189 dst_address.sin6.sin6_scope_id = 190 ntohs(dst_address.sin6.sin6_addr.s6_addr16[1]); 191 dst_address.sin6.sin6_addr.s6_addr16[1] = 0; 192 } 193 break; 194 #endif /* INET6 */ 195 default: 196 DPRINTF(("%s: unsupported protocol family %u\n", __func__, af)); 197 m_freem(m); 198 IPSEC_ISTAT(sproto, nopf); 199 return EPFNOSUPPORT; 200 } 201 202 /* NB: only pass dst since key_allocsa follows RFC2401 */ 203 sav = key_allocsa(&dst_address, sproto, spi); 204 if (sav == NULL) { 205 DPRINTF(("%s: no key association found for SA %s/%08lx/%u\n", 206 __func__, ipsec_address(&dst_address, buf, sizeof(buf)), 207 (u_long) ntohl(spi), sproto)); 208 IPSEC_ISTAT(sproto, notdb); 209 m_freem(m); 210 return ENOENT; 211 } 212 213 if (sav->tdb_xform == NULL) { 214 DPRINTF(("%s: attempted to use uninitialized SA %s/%08lx/%u\n", 215 __func__, ipsec_address(&dst_address, buf, sizeof(buf)), 216 (u_long) ntohl(spi), sproto)); 217 IPSEC_ISTAT(sproto, noxform); 218 key_freesav(&sav); 219 m_freem(m); 220 return ENXIO; 221 } 222 223 /* 224 * Call appropriate transform and return -- callback takes care of 225 * everything else. 226 */ 227 error = (*sav->tdb_xform->xf_input)(m, sav, skip, protoff); 228 return (error); 229 } 230 231 #ifdef INET 232 /* 233 * IPSEC_INPUT() method implementation for IPv4. 234 * 0 - Permitted by inbound security policy for further processing. 235 * EACCES - Forbidden by inbound security policy. 236 * EINPROGRESS - consumed by IPsec. 237 */ 238 int 239 ipsec4_input(struct mbuf *m, int offset, int proto) 240 { 241 242 switch (proto) { 243 case IPPROTO_AH: 244 case IPPROTO_ESP: 245 case IPPROTO_IPCOMP: 246 /* Do inbound IPsec processing for AH/ESP/IPCOMP */ 247 ipsec_common_input(m, offset, 248 offsetof(struct ip, ip_p), AF_INET, proto); 249 return (EINPROGRESS); /* mbuf consumed by IPsec */ 250 default: 251 /* 252 * Protocols with further headers get their IPsec treatment 253 * within the protocol specific processing. 254 */ 255 switch (proto) { 256 case IPPROTO_ICMP: 257 case IPPROTO_IGMP: 258 case IPPROTO_IPV4: 259 case IPPROTO_IPV6: 260 case IPPROTO_RSVP: 261 case IPPROTO_GRE: 262 case IPPROTO_MOBILE: 263 case IPPROTO_ETHERIP: 264 case IPPROTO_PIM: 265 case IPPROTO_SCTP: 266 break; 267 default: 268 return (0); 269 } 270 }; 271 /* 272 * Enforce IPsec policy checking if we are seeing last header. 273 */ 274 if (ipsec4_in_reject(m, NULL) != 0) { 275 /* Forbidden by inbound security policy */ 276 m_freem(m); 277 return (EACCES); 278 } 279 return (0); 280 } 281 282 int 283 ipsec4_ctlinput(ipsec_ctlinput_param_t param) 284 { 285 struct icmp *icp = param.icmp; 286 struct ip *ip = &icp->icmp_ip; 287 struct sockaddr_in icmpsrc = { 288 .sin_len = sizeof(struct sockaddr_in), 289 .sin_family = AF_INET, 290 .sin_addr = ip->ip_dst, 291 }; 292 struct in_conninfo inc; 293 struct secasvar *sav; 294 uint32_t pmtu, spi; 295 uint32_t max_pmtu; 296 uint8_t proto; 297 298 pmtu = ntohs(icp->icmp_nextmtu); 299 300 if (pmtu < V_ip4_ipsec_min_pmtu) 301 return (EINVAL); 302 303 proto = ip->ip_p; 304 if (proto != IPPROTO_ESP && proto != IPPROTO_AH && 305 proto != IPPROTO_IPCOMP) 306 return (EINVAL); 307 308 memcpy(&spi, (caddr_t)ip + (ip->ip_hl << 2), sizeof(spi)); 309 sav = key_allocsa((union sockaddr_union *)&icmpsrc, proto, spi); 310 if (sav == NULL) 311 return (ENOENT); 312 313 key_freesav(&sav); 314 315 memset(&inc, 0, sizeof(inc)); 316 inc.inc_faddr = ip->ip_dst; 317 318 /* Update pmtu only if its smaller than the current one. */ 319 max_pmtu = tcp_hc_getmtu(&inc); 320 if (max_pmtu == 0) 321 max_pmtu = tcp_maxmtu(&inc, NULL); 322 323 if (pmtu < max_pmtu) 324 tcp_hc_updatemtu(&inc, pmtu); 325 326 return (0); 327 } 328 329 /* 330 * IPsec input callback for INET protocols. 331 * This routine is called as the transform callback. 332 * Takes care of filtering and other sanity checks on 333 * the processed packet. 334 */ 335 int 336 ipsec4_common_input_cb(struct mbuf *m, struct secasvar *sav, int skip, 337 int protoff) 338 { 339 IPSEC_DEBUG_DECLARE(char buf[IPSEC_ADDRSTRLEN]); 340 struct epoch_tracker et; 341 struct ipsec_ctx_data ctx; 342 struct xform_history *xh; 343 struct secasindex *saidx; 344 struct m_tag *mtag; 345 struct ip *ip; 346 int error, prot, af, sproto, isr_prot; 347 348 IPSEC_ASSERT(sav != NULL, ("null SA")); 349 IPSEC_ASSERT(sav->sah != NULL, ("null SAH")); 350 saidx = &sav->sah->saidx; 351 af = saidx->dst.sa.sa_family; 352 IPSEC_ASSERT(af == AF_INET, ("unexpected af %u", af)); 353 sproto = saidx->proto; 354 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH || 355 sproto == IPPROTO_IPCOMP, 356 ("unexpected security protocol %u", sproto)); 357 358 if (skip != 0) { 359 /* 360 * Fix IPv4 header 361 */ 362 if (m->m_len < skip && (m = m_pullup(m, skip)) == NULL) { 363 DPRINTF(("%s: processing failed for SA %s/%08lx\n", 364 __func__, ipsec_address(&sav->sah->saidx.dst, 365 buf, sizeof(buf)), (u_long) ntohl(sav->spi))); 366 IPSEC_ISTAT(sproto, hdrops); 367 error = ENOBUFS; 368 goto bad_noepoch; 369 } 370 371 ip = mtod(m, struct ip *); 372 ip->ip_len = htons(m->m_pkthdr.len); 373 ip->ip_sum = 0; 374 ip->ip_sum = in_cksum(m, ip->ip_hl << 2); 375 } else { 376 ip = mtod(m, struct ip *); 377 } 378 prot = ip->ip_p; 379 /* 380 * Check that we have NAT-T enabled and apply transport mode 381 * decapsulation NAT procedure (RFC3948). 382 * Do this before invoking into the PFIL. 383 */ 384 if (sav->natt != NULL && 385 (prot == IPPROTO_UDP || prot == IPPROTO_TCP)) 386 udp_ipsec_adjust_cksum(m, sav, prot, skip); 387 388 /* 389 * Needed for ipsec_run_hooks and netisr_queue_src 390 */ 391 NET_EPOCH_ENTER(et); 392 393 IPSEC_INIT_CTX(&ctx, &m, NULL, sav, AF_INET, IPSEC_ENC_BEFORE); 394 if ((error = ipsec_run_hhooks(&ctx, HHOOK_TYPE_IPSEC_IN)) != 0) 395 goto bad; 396 ip = mtod(m, struct ip *); /* update pointer */ 397 398 /* IP-in-IP encapsulation */ 399 if (prot == IPPROTO_IPIP && 400 saidx->mode != IPSEC_MODE_TRANSPORT) { 401 if (m->m_pkthdr.len - skip < sizeof(struct ip)) { 402 IPSEC_ISTAT(sproto, hdrops); 403 error = EINVAL; 404 goto bad; 405 } 406 /* enc0: strip outer IPv4 header */ 407 m_striphdr(m, 0, ip->ip_hl << 2); 408 } 409 #ifdef INET6 410 /* IPv6-in-IP encapsulation. */ 411 else if (prot == IPPROTO_IPV6 && 412 saidx->mode != IPSEC_MODE_TRANSPORT) { 413 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) { 414 IPSEC_ISTAT(sproto, hdrops); 415 error = EINVAL; 416 goto bad; 417 } 418 /* enc0: strip IPv4 header, keep IPv6 header only */ 419 m_striphdr(m, 0, ip->ip_hl << 2); 420 } 421 #endif /* INET6 */ 422 else if (prot != IPPROTO_IPV6 && saidx->mode == IPSEC_MODE_ANY) { 423 /* 424 * When mode is wildcard, inner protocol is IPv6 and 425 * we have no INET6 support - drop this packet a bit later. 426 * In other cases we assume transport mode. Set prot to 427 * correctly choose netisr. 428 */ 429 prot = IPPROTO_IPIP; 430 } 431 432 /* 433 * Record what we've done to the packet (under what SA it was 434 * processed). 435 */ 436 if (sproto != IPPROTO_IPCOMP) { 437 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE, 438 sizeof(struct xform_history), M_NOWAIT); 439 if (mtag == NULL) { 440 DPRINTF(("%s: failed to get tag\n", __func__)); 441 IPSEC_ISTAT(sproto, hdrops); 442 error = ENOMEM; 443 goto bad; 444 } 445 446 xh = (struct xform_history *)(mtag + 1); 447 bcopy(&saidx->dst, &xh->dst, saidx->dst.sa.sa_len); 448 xh->spi = sav->spi; 449 xh->proto = sproto; 450 xh->mode = saidx->mode; 451 m_tag_prepend(m, mtag); 452 } 453 454 key_sa_recordxfer(sav, m); /* record data transfer */ 455 456 /* 457 * In transport mode requeue decrypted mbuf back to IPv4 protocol 458 * handler. This is necessary to correctly expose rcvif. 459 */ 460 if (saidx->mode == IPSEC_MODE_TRANSPORT) 461 prot = IPPROTO_IPIP; 462 /* 463 * Re-dispatch via software interrupt. 464 */ 465 switch (prot) { 466 case IPPROTO_IPIP: 467 isr_prot = NETISR_IP; 468 af = AF_INET; 469 break; 470 #ifdef INET6 471 case IPPROTO_IPV6: 472 isr_prot = NETISR_IPV6; 473 af = AF_INET6; 474 break; 475 #endif 476 default: 477 DPRINTF(("%s: cannot handle inner ip proto %d\n", 478 __func__, prot)); 479 IPSEC_ISTAT(sproto, nopf); 480 error = EPFNOSUPPORT; 481 goto bad; 482 } 483 484 IPSEC_INIT_CTX(&ctx, &m, NULL, sav, af, IPSEC_ENC_AFTER); 485 if ((error = ipsec_run_hhooks(&ctx, HHOOK_TYPE_IPSEC_IN)) != 0) 486 goto bad; 487 488 /* Handle virtual tunneling interfaces */ 489 if (saidx->mode == IPSEC_MODE_TUNNEL) 490 error = ipsec_if_input(m, sav, af); 491 if (error == 0) { 492 error = netisr_queue_src(isr_prot, (uintptr_t)sav->spi, m); 493 if (error) { 494 IPSEC_ISTAT(sproto, qfull); 495 DPRINTF(("%s: queue full; proto %u packet dropped\n", 496 __func__, sproto)); 497 } 498 } 499 NET_EPOCH_EXIT(et); 500 key_freesav(&sav); 501 return (error); 502 bad: 503 NET_EPOCH_EXIT(et); 504 bad_noepoch: 505 key_freesav(&sav); 506 if (m != NULL) 507 m_freem(m); 508 return (error); 509 } 510 #endif /* INET */ 511 512 #ifdef INET6 513 static bool 514 ipsec6_lasthdr(int proto) 515 { 516 517 switch (proto) { 518 case IPPROTO_IPV4: 519 case IPPROTO_IPV6: 520 case IPPROTO_GRE: 521 case IPPROTO_ICMPV6: 522 case IPPROTO_ETHERIP: 523 case IPPROTO_PIM: 524 case IPPROTO_SCTP: 525 return (true); 526 default: 527 return (false); 528 }; 529 } 530 531 /* 532 * IPSEC_INPUT() method implementation for IPv6. 533 * 0 - Permitted by inbound security policy for further processing. 534 * EACCES - Forbidden by inbound security policy. 535 * EINPROGRESS - consumed by IPsec. 536 */ 537 int 538 ipsec6_input(struct mbuf *m, int offset, int proto) 539 { 540 541 switch (proto) { 542 case IPPROTO_AH: 543 case IPPROTO_ESP: 544 case IPPROTO_IPCOMP: 545 /* Do inbound IPsec processing for AH/ESP/IPCOMP */ 546 ipsec_common_input(m, offset, 547 offsetof(struct ip6_hdr, ip6_nxt), AF_INET6, proto); 548 return (EINPROGRESS); /* mbuf consumed by IPsec */ 549 default: 550 /* 551 * Protocols with further headers get their IPsec treatment 552 * within the protocol specific processing. 553 */ 554 if (!ipsec6_lasthdr(proto)) 555 return (0); 556 /* FALLTHROUGH */ 557 }; 558 /* 559 * Enforce IPsec policy checking if we are seeing last header. 560 */ 561 if (ipsec6_in_reject(m, NULL) != 0) { 562 /* Forbidden by inbound security policy */ 563 m_freem(m); 564 return (EACCES); 565 } 566 return (0); 567 } 568 569 int 570 ipsec6_ctlinput(ipsec_ctlinput_param_t param) 571 { 572 return (0); 573 } 574 575 extern ipproto_input_t *ip6_protox[]; 576 577 /* 578 * IPsec input callback, called by the transform callback. Takes care of 579 * filtering and other sanity checks on the processed packet. 580 */ 581 int 582 ipsec6_common_input_cb(struct mbuf *m, struct secasvar *sav, int skip, 583 int protoff) 584 { 585 IPSEC_DEBUG_DECLARE(char buf[IPSEC_ADDRSTRLEN]); 586 struct epoch_tracker et; 587 struct ipsec_ctx_data ctx; 588 struct xform_history *xh; 589 struct secasindex *saidx; 590 struct ip6_hdr *ip6; 591 struct m_tag *mtag; 592 int prot, af, sproto; 593 int nxt, isr_prot; 594 int error, nest; 595 uint8_t nxt8; 596 597 IPSEC_ASSERT(sav != NULL, ("null SA")); 598 IPSEC_ASSERT(sav->sah != NULL, ("null SAH")); 599 saidx = &sav->sah->saidx; 600 af = saidx->dst.sa.sa_family; 601 IPSEC_ASSERT(af == AF_INET6, ("unexpected af %u", af)); 602 sproto = saidx->proto; 603 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH || 604 sproto == IPPROTO_IPCOMP, 605 ("unexpected security protocol %u", sproto)); 606 607 NET_EPOCH_ENTER(et); 608 609 /* Fix IPv6 header */ 610 if (m->m_len < sizeof(struct ip6_hdr) && 611 (m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 612 DPRINTF(("%s: processing failed for SA %s/%08lx\n", 613 __func__, ipsec_address(&sav->sah->saidx.dst, buf, 614 sizeof(buf)), (u_long) ntohl(sav->spi))); 615 616 IPSEC_ISTAT(sproto, hdrops); 617 error = EACCES; 618 goto bad; 619 } 620 621 IPSEC_INIT_CTX(&ctx, &m, NULL, sav, af, IPSEC_ENC_BEFORE); 622 if ((error = ipsec_run_hhooks(&ctx, HHOOK_TYPE_IPSEC_IN)) != 0) 623 goto bad; 624 625 ip6 = mtod(m, struct ip6_hdr *); 626 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 627 628 /* Save protocol */ 629 m_copydata(m, protoff, 1, &nxt8); 630 prot = nxt8; 631 632 /* IPv6-in-IP encapsulation */ 633 if (prot == IPPROTO_IPV6 && 634 saidx->mode != IPSEC_MODE_TRANSPORT) { 635 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) { 636 IPSEC_ISTAT(sproto, hdrops); 637 error = EINVAL; 638 goto bad; 639 } 640 /* ip6n will now contain the inner IPv6 header. */ 641 m_striphdr(m, 0, skip); 642 skip = 0; 643 } 644 #ifdef INET 645 /* IP-in-IP encapsulation */ 646 else if (prot == IPPROTO_IPIP && 647 saidx->mode != IPSEC_MODE_TRANSPORT) { 648 if (m->m_pkthdr.len - skip < sizeof(struct ip)) { 649 IPSEC_ISTAT(sproto, hdrops); 650 error = EINVAL; 651 goto bad; 652 } 653 /* ipn will now contain the inner IPv4 header */ 654 m_striphdr(m, 0, skip); 655 skip = 0; 656 } 657 #endif /* INET */ 658 else { 659 prot = IPPROTO_IPV6; /* for correct BPF processing */ 660 } 661 662 /* 663 * Record what we've done to the packet (under what SA it was 664 * processed). 665 */ 666 if (sproto != IPPROTO_IPCOMP) { 667 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE, 668 sizeof(struct xform_history), M_NOWAIT); 669 if (mtag == NULL) { 670 DPRINTF(("%s: failed to get tag\n", __func__)); 671 IPSEC_ISTAT(sproto, hdrops); 672 error = ENOMEM; 673 goto bad; 674 } 675 676 xh = (struct xform_history *)(mtag + 1); 677 bcopy(&saidx->dst, &xh->dst, saidx->dst.sa.sa_len); 678 xh->spi = sav->spi; 679 xh->proto = sproto; 680 xh->mode = saidx->mode; 681 m_tag_prepend(m, mtag); 682 } 683 684 key_sa_recordxfer(sav, m); 685 686 #ifdef INET 687 if (prot == IPPROTO_IPIP) 688 af = AF_INET; 689 else 690 #endif 691 af = AF_INET6; 692 IPSEC_INIT_CTX(&ctx, &m, NULL, sav, af, IPSEC_ENC_AFTER); 693 if ((error = ipsec_run_hhooks(&ctx, HHOOK_TYPE_IPSEC_IN)) != 0) 694 goto bad; 695 if (skip == 0) { 696 /* 697 * We stripped outer IPv6 header. 698 * Now we should requeue decrypted packet via netisr. 699 */ 700 switch (prot) { 701 #ifdef INET 702 case IPPROTO_IPIP: 703 isr_prot = NETISR_IP; 704 break; 705 #endif 706 case IPPROTO_IPV6: 707 isr_prot = NETISR_IPV6; 708 break; 709 default: 710 DPRINTF(("%s: cannot handle inner ip proto %d\n", 711 __func__, prot)); 712 IPSEC_ISTAT(sproto, nopf); 713 error = EPFNOSUPPORT; 714 goto bad; 715 } 716 /* Handle virtual tunneling interfaces */ 717 if (saidx->mode == IPSEC_MODE_TUNNEL) 718 error = ipsec_if_input(m, sav, af); 719 if (error == 0) { 720 error = netisr_queue_src(isr_prot, 721 (uintptr_t)sav->spi, m); 722 if (error) { 723 IPSEC_ISTAT(sproto, qfull); 724 DPRINTF(("%s: queue full; proto %u packet" 725 " dropped\n", __func__, sproto)); 726 } 727 } 728 NET_EPOCH_EXIT(et); 729 key_freesav(&sav); 730 return (error); 731 } 732 /* 733 * See the end of ip6_input for this logic. 734 * IPPROTO_IPV[46] case will be processed just like other ones 735 */ 736 nest = 0; 737 nxt = nxt8; 738 while (nxt != IPPROTO_DONE) { 739 if (V_ip6_hdrnestlimit && (++nest > V_ip6_hdrnestlimit)) { 740 IP6STAT_INC(ip6s_toomanyhdr); 741 error = EINVAL; 742 goto bad; 743 } 744 745 /* 746 * Protection against faulty packet - there should be 747 * more sanity checks in header chain processing. 748 */ 749 if (m->m_pkthdr.len < skip) { 750 IP6STAT_INC(ip6s_tooshort); 751 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 752 error = EINVAL; 753 goto bad; 754 } 755 /* 756 * Enforce IPsec policy checking if we are seeing last header. 757 * note that we do not visit this with protocols with pcb layer 758 * code - like udp/tcp/raw ip. 759 */ 760 if (ipsec6_lasthdr(nxt) && ipsec6_in_reject(m, NULL)) { 761 error = EINVAL; 762 goto bad; 763 } 764 nxt = ip6_protox[nxt](&m, &skip, nxt); 765 } 766 NET_EPOCH_EXIT(et); 767 key_freesav(&sav); 768 return (0); 769 bad: 770 NET_EPOCH_EXIT(et); 771 key_freesav(&sav); 772 if (m) 773 m_freem(m); 774 return (error); 775 } 776 #endif /* INET6 */ 777