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: stable/11/sys/netipsec/ipsec_input.c 322741 2017-08-21 09:03:20Z ae $"); 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_systm.h> 69#include <netinet/ip.h> 70#include <netinet/ip_var.h> 71#include <netinet/in_var.h> 72 73#include <netinet/ip6.h> 74#ifdef INET6 75#include <netinet6/ip6_var.h> 76#endif 77#include <netinet/in_pcb.h> 78#ifdef INET6 79#include <netinet/icmp6.h> 80#endif 81 82#include <netipsec/ipsec.h> 83#ifdef INET6 84#include <netipsec/ipsec6.h> 85#endif 86#include <netipsec/ah_var.h> 87#include <netipsec/esp.h> 88#include <netipsec/esp_var.h> 89#include <netipsec/ipcomp_var.h> 90 91#include <netipsec/key.h> 92#include <netipsec/keydb.h> 93#include <netipsec/key_debug.h> 94 95#include <netipsec/xform.h> 96#include <netinet6/ip6protosw.h> 97 98#include <machine/in_cksum.h> 99#include <machine/stdarg.h> 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/* 112 * ipsec_common_input gets called when an IPsec-protected packet 113 * is received by IPv4 or IPv6. Its job is to find the right SA 114 * and call the appropriate transform. The transform callback 115 * takes care of further processing (like ingress filtering). 116 */ 117static int 118ipsec_common_input(struct mbuf *m, int skip, int protoff, int af, int sproto) 119{ 120 IPSEC_DEBUG_DECLARE(char buf[IPSEC_ADDRSTRLEN]); 121 union sockaddr_union dst_address; 122 struct secasvar *sav; 123 uint32_t spi; 124 int error; 125 126 IPSEC_ISTAT(sproto, input); 127 128 IPSEC_ASSERT(m != NULL, ("null packet")); 129 130 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH || 131 sproto == IPPROTO_IPCOMP, 132 ("unexpected security protocol %u", sproto)); 133 134 if ((sproto == IPPROTO_ESP && !V_esp_enable) || 135 (sproto == IPPROTO_AH && !V_ah_enable) || 136 (sproto == IPPROTO_IPCOMP && !V_ipcomp_enable)) { 137 m_freem(m); 138 IPSEC_ISTAT(sproto, pdrops); 139 return EOPNOTSUPP; 140 } 141 142 if (m->m_pkthdr.len - skip < 2 * sizeof (u_int32_t)) { 143 m_freem(m); 144 IPSEC_ISTAT(sproto, hdrops); 145 DPRINTF(("%s: packet too small\n", __func__)); 146 return EINVAL; 147 } 148 149 /* Retrieve the SPI from the relevant IPsec header */ 150 if (sproto == IPPROTO_ESP) 151 m_copydata(m, skip, sizeof(u_int32_t), (caddr_t) &spi); 152 else if (sproto == IPPROTO_AH) 153 m_copydata(m, skip + sizeof(u_int32_t), sizeof(u_int32_t), 154 (caddr_t) &spi); 155 else if (sproto == IPPROTO_IPCOMP) { 156 u_int16_t cpi; 157 m_copydata(m, skip + sizeof(u_int16_t), sizeof(u_int16_t), 158 (caddr_t) &cpi); 159 spi = ntohl(htons(cpi)); 160 } 161 162 /* 163 * Find the SA and (indirectly) call the appropriate 164 * kernel crypto routine. The resulting mbuf chain is a valid 165 * IP packet ready to go through input processing. 166 */ 167 bzero(&dst_address, sizeof (dst_address)); 168 dst_address.sa.sa_family = af; 169 switch (af) { 170#ifdef INET 171 case AF_INET: 172 dst_address.sin.sin_len = sizeof(struct sockaddr_in); 173 m_copydata(m, offsetof(struct ip, ip_dst), 174 sizeof(struct in_addr), 175 (caddr_t) &dst_address.sin.sin_addr); 176 break; 177#endif /* INET */ 178#ifdef INET6 179 case AF_INET6: 180 dst_address.sin6.sin6_len = sizeof(struct sockaddr_in6); 181 m_copydata(m, offsetof(struct ip6_hdr, ip6_dst), 182 sizeof(struct in6_addr), 183 (caddr_t) &dst_address.sin6.sin6_addr); 184 /* We keep addresses in SADB without embedded scope id */ 185 if (IN6_IS_SCOPE_LINKLOCAL(&dst_address.sin6.sin6_addr)) { 186 /* XXX: sa6_recoverscope() */ 187 dst_address.sin6.sin6_scope_id = 188 ntohs(dst_address.sin6.sin6_addr.s6_addr16[1]); 189 dst_address.sin6.sin6_addr.s6_addr16[1] = 0; 190 } 191 break; 192#endif /* INET6 */ 193 default: 194 DPRINTF(("%s: unsupported protocol family %u\n", __func__, af)); 195 m_freem(m); 196 IPSEC_ISTAT(sproto, nopf); 197 return EPFNOSUPPORT; 198 } 199 200 /* NB: only pass dst since key_allocsa follows RFC2401 */ 201 sav = key_allocsa(&dst_address, sproto, spi); 202 if (sav == NULL) { 203 DPRINTF(("%s: no key association found for SA %s/%08lx/%u\n", 204 __func__, ipsec_address(&dst_address, buf, sizeof(buf)), 205 (u_long) ntohl(spi), sproto)); 206 IPSEC_ISTAT(sproto, notdb); 207 m_freem(m); 208 return ENOENT; 209 } 210 211 if (sav->tdb_xform == NULL) { 212 DPRINTF(("%s: attempted to use uninitialized SA %s/%08lx/%u\n", 213 __func__, ipsec_address(&dst_address, buf, sizeof(buf)), 214 (u_long) ntohl(spi), sproto)); 215 IPSEC_ISTAT(sproto, noxform); 216 key_freesav(&sav); 217 m_freem(m); 218 return ENXIO; 219 } 220 221 /* 222 * Call appropriate transform and return -- callback takes care of 223 * everything else. 224 */ 225 error = (*sav->tdb_xform->xf_input)(m, sav, skip, protoff); 226 return (error); 227} 228 229#ifdef INET 230extern struct protosw inetsw[]; 231 232/* 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 */ 238int 239ipsec4_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 if ((inetsw[ip_protox[proto]].pr_flags & PR_LASTHDR) == 0) 256 return (0); 257 /* FALLTHROUGH */ 258 }; 259 /* 260 * Enforce IPsec policy checking if we are seeing last header. 261 */ 262 if (ipsec4_in_reject(m, NULL) != 0) { 263 /* Forbidden by inbound security policy */ 264 m_freem(m); 265 return (EACCES); 266 } 267 return (0); 268} 269 270/* 271 * IPsec input callback for INET protocols. 272 * This routine is called as the transform callback. 273 * Takes care of filtering and other sanity checks on 274 * the processed packet. 275 */ 276int 277ipsec4_common_input_cb(struct mbuf *m, struct secasvar *sav, int skip, 278 int protoff) 279{ 280 IPSEC_DEBUG_DECLARE(char buf[IPSEC_ADDRSTRLEN]); 281 struct ipsec_ctx_data ctx; 282 struct xform_history *xh; 283 struct secasindex *saidx; 284 struct m_tag *mtag; 285 struct ip *ip; 286 int error, prot, af, sproto, isr_prot; 287 288 IPSEC_ASSERT(sav != NULL, ("null SA")); 289 IPSEC_ASSERT(sav->sah != NULL, ("null SAH")); 290 saidx = &sav->sah->saidx; 291 af = saidx->dst.sa.sa_family; 292 IPSEC_ASSERT(af == AF_INET, ("unexpected af %u", af)); 293 sproto = saidx->proto; 294 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH || 295 sproto == IPPROTO_IPCOMP, 296 ("unexpected security protocol %u", sproto)); 297 298 if (skip != 0) { 299 /* 300 * Fix IPv4 header 301 */ 302 if (m->m_len < skip && (m = m_pullup(m, skip)) == NULL) { 303 DPRINTF(("%s: processing failed for SA %s/%08lx\n", 304 __func__, ipsec_address(&sav->sah->saidx.dst, 305 buf, sizeof(buf)), (u_long) ntohl(sav->spi))); 306 IPSEC_ISTAT(sproto, hdrops); 307 error = ENOBUFS; 308 goto bad; 309 } 310 311 ip = mtod(m, struct ip *); 312 ip->ip_len = htons(m->m_pkthdr.len); 313 ip->ip_sum = 0; 314 ip->ip_sum = in_cksum(m, ip->ip_hl << 2); 315 } else { 316 ip = mtod(m, struct ip *); 317 } 318 prot = ip->ip_p; 319 /* 320 * Check that we have NAT-T enabled and apply transport mode 321 * decapsulation NAT procedure (RFC3948). 322 * Do this before invoking into the PFIL. 323 */ 324 if (sav->natt != NULL && 325 (prot == IPPROTO_UDP || prot == IPPROTO_TCP)) 326 udp_ipsec_adjust_cksum(m, sav, prot, skip); 327 328 IPSEC_INIT_CTX(&ctx, &m, NULL, sav, AF_INET, IPSEC_ENC_BEFORE); 329 if ((error = ipsec_run_hhooks(&ctx, HHOOK_TYPE_IPSEC_IN)) != 0) 330 goto bad; 331 ip = mtod(m, struct ip *); /* update pointer */ 332 333 /* IP-in-IP encapsulation */ 334 if (prot == IPPROTO_IPIP && 335 saidx->mode != IPSEC_MODE_TRANSPORT) { 336 if (m->m_pkthdr.len - skip < sizeof(struct ip)) { 337 IPSEC_ISTAT(sproto, hdrops); 338 error = EINVAL; 339 goto bad; 340 } 341 /* enc0: strip outer IPv4 header */ 342 m_striphdr(m, 0, ip->ip_hl << 2); 343 } 344#ifdef INET6 345 /* IPv6-in-IP encapsulation. */ 346 else if (prot == IPPROTO_IPV6 && 347 saidx->mode != IPSEC_MODE_TRANSPORT) { 348 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) { 349 IPSEC_ISTAT(sproto, hdrops); 350 error = EINVAL; 351 goto bad; 352 } 353 /* enc0: strip IPv4 header, keep IPv6 header only */ 354 m_striphdr(m, 0, ip->ip_hl << 2); 355 } 356#endif /* INET6 */ 357 else if (prot != IPPROTO_IPV6 && saidx->mode == IPSEC_MODE_ANY) { 358 /* 359 * When mode is wildcard, inner protocol is IPv6 and 360 * we have no INET6 support - drop this packet a bit later. 361 * In other cases we assume transport mode. Set prot to 362 * correctly choose netisr. 363 */ 364 prot = IPPROTO_IPIP; 365 } 366 367 /* 368 * Record what we've done to the packet (under what SA it was 369 * processed). 370 */ 371 if (sproto != IPPROTO_IPCOMP) { 372 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE, 373 sizeof(struct xform_history), M_NOWAIT); 374 if (mtag == NULL) { 375 DPRINTF(("%s: failed to get tag\n", __func__)); 376 IPSEC_ISTAT(sproto, hdrops); 377 error = ENOMEM; 378 goto bad; 379 } 380 381 xh = (struct xform_history *)(mtag + 1); 382 bcopy(&saidx->dst, &xh->dst, saidx->dst.sa.sa_len); 383 xh->spi = sav->spi; 384 xh->proto = sproto; 385 xh->mode = saidx->mode; 386 m_tag_prepend(m, mtag); 387 } 388 389 key_sa_recordxfer(sav, m); /* record data transfer */ 390 391 /* 392 * In transport mode requeue decrypted mbuf back to IPv4 protocol 393 * handler. This is necessary to correctly expose rcvif. 394 */ 395 if (saidx->mode == IPSEC_MODE_TRANSPORT) 396 prot = IPPROTO_IPIP; 397 /* 398 * Re-dispatch via software interrupt. 399 */ 400 switch (prot) { 401 case IPPROTO_IPIP: 402 isr_prot = NETISR_IP; 403 af = AF_INET; 404 break; 405#ifdef INET6 406 case IPPROTO_IPV6: 407 isr_prot = NETISR_IPV6; 408 af = AF_INET6; 409 break; 410#endif 411 default: 412 DPRINTF(("%s: cannot handle inner ip proto %d\n", 413 __func__, prot)); 414 IPSEC_ISTAT(sproto, nopf); 415 error = EPFNOSUPPORT; 416 goto bad; 417 } 418 419 IPSEC_INIT_CTX(&ctx, &m, NULL, sav, af, IPSEC_ENC_AFTER); 420 if ((error = ipsec_run_hhooks(&ctx, HHOOK_TYPE_IPSEC_IN)) != 0) 421 goto bad; 422 423 /* Handle virtual tunneling interfaces */ 424 if (saidx->mode == IPSEC_MODE_TUNNEL) 425 error = ipsec_if_input(m, sav, af); 426 if (error == 0) { 427 error = netisr_queue_src(isr_prot, (uintptr_t)sav->spi, m); 428 if (error) { 429 IPSEC_ISTAT(sproto, qfull); 430 DPRINTF(("%s: queue full; proto %u packet dropped\n", 431 __func__, sproto)); 432 } 433 } 434 key_freesav(&sav); 435 return (error); 436bad: 437 key_freesav(&sav); 438 if (m != NULL) 439 m_freem(m); 440 return (error); 441} 442#endif /* INET */ 443 444#ifdef INET6 445/* 446 * IPSEC_INPUT() method implementation for IPv6. 447 * 0 - Permitted by inbound security policy for further processing. 448 * EACCES - Forbidden by inbound security policy. 449 * EINPROGRESS - consumed by IPsec. 450 */ 451int 452ipsec6_input(struct mbuf *m, int offset, int proto) 453{ 454 455 switch (proto) { 456 case IPPROTO_AH: 457 case IPPROTO_ESP: 458 case IPPROTO_IPCOMP: 459 /* Do inbound IPsec processing for AH/ESP/IPCOMP */ 460 ipsec_common_input(m, offset, 461 offsetof(struct ip6_hdr, ip6_nxt), AF_INET6, proto); 462 return (EINPROGRESS); /* mbuf consumed by IPsec */ 463 default: 464 /* 465 * Protocols with further headers get their IPsec treatment 466 * within the protocol specific processing. 467 */ 468 if ((inet6sw[ip6_protox[proto]].pr_flags & PR_LASTHDR) == 0) 469 return (0); 470 /* FALLTHROUGH */ 471 }; 472 /* 473 * Enforce IPsec policy checking if we are seeing last header. 474 */ 475 if (ipsec6_in_reject(m, NULL) != 0) { 476 /* Forbidden by inbound security policy */ 477 m_freem(m); 478 return (EACCES); 479 } 480 return (0); 481} 482 483/* 484 * IPsec input callback, called by the transform callback. Takes care of 485 * filtering and other sanity checks on the processed packet. 486 */ 487int 488ipsec6_common_input_cb(struct mbuf *m, struct secasvar *sav, int skip, 489 int protoff) 490{ 491 IPSEC_DEBUG_DECLARE(char buf[IPSEC_ADDRSTRLEN]); 492 struct ipsec_ctx_data ctx; 493 struct xform_history *xh; 494 struct secasindex *saidx; 495 struct ip6_hdr *ip6; 496 struct m_tag *mtag; 497 int prot, af, sproto; 498 int nxt, isr_prot; 499 int error, nest; 500 uint8_t nxt8; 501 502 IPSEC_ASSERT(sav != NULL, ("null SA")); 503 IPSEC_ASSERT(sav->sah != NULL, ("null SAH")); 504 saidx = &sav->sah->saidx; 505 af = saidx->dst.sa.sa_family; 506 IPSEC_ASSERT(af == AF_INET6, ("unexpected af %u", af)); 507 sproto = saidx->proto; 508 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH || 509 sproto == IPPROTO_IPCOMP, 510 ("unexpected security protocol %u", sproto)); 511 512 /* Fix IPv6 header */ 513 if (m->m_len < sizeof(struct ip6_hdr) && 514 (m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 515 516 DPRINTF(("%s: processing failed for SA %s/%08lx\n", 517 __func__, ipsec_address(&sav->sah->saidx.dst, buf, 518 sizeof(buf)), (u_long) ntohl(sav->spi))); 519 520 IPSEC_ISTAT(sproto, hdrops); 521 error = EACCES; 522 goto bad; 523 } 524 525 IPSEC_INIT_CTX(&ctx, &m, NULL, sav, af, IPSEC_ENC_BEFORE); 526 if ((error = ipsec_run_hhooks(&ctx, HHOOK_TYPE_IPSEC_IN)) != 0) 527 goto bad; 528 529 ip6 = mtod(m, struct ip6_hdr *); 530 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 531 532 /* Save protocol */ 533 m_copydata(m, protoff, 1, &nxt8); 534 prot = nxt8; 535 536 /* IPv6-in-IP encapsulation */ 537 if (prot == IPPROTO_IPV6 && 538 saidx->mode != IPSEC_MODE_TRANSPORT) { 539 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) { 540 IPSEC_ISTAT(sproto, hdrops); 541 error = EINVAL; 542 goto bad; 543 } 544 /* ip6n will now contain the inner IPv6 header. */ 545 m_striphdr(m, 0, skip); 546 skip = 0; 547 } 548#ifdef INET 549 /* IP-in-IP encapsulation */ 550 else if (prot == IPPROTO_IPIP && 551 saidx->mode != IPSEC_MODE_TRANSPORT) { 552 if (m->m_pkthdr.len - skip < sizeof(struct ip)) { 553 IPSEC_ISTAT(sproto, hdrops); 554 error = EINVAL; 555 goto bad; 556 } 557 /* ipn will now contain the inner IPv4 header */ 558 m_striphdr(m, 0, skip); 559 skip = 0; 560 } 561#endif /* INET */ 562 else { 563 prot = IPPROTO_IPV6; /* for correct BPF processing */ 564 } 565 566 /* 567 * Record what we've done to the packet (under what SA it was 568 * processed). 569 */ 570 if (sproto != IPPROTO_IPCOMP) { 571 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE, 572 sizeof(struct xform_history), M_NOWAIT); 573 if (mtag == NULL) { 574 DPRINTF(("%s: failed to get tag\n", __func__)); 575 IPSEC_ISTAT(sproto, hdrops); 576 error = ENOMEM; 577 goto bad; 578 } 579 580 xh = (struct xform_history *)(mtag + 1); 581 bcopy(&saidx->dst, &xh->dst, saidx->dst.sa.sa_len); 582 xh->spi = sav->spi; 583 xh->proto = sproto; 584 xh->mode = saidx->mode; 585 m_tag_prepend(m, mtag); 586 } 587 588 key_sa_recordxfer(sav, m); 589 590#ifdef INET 591 if (prot == IPPROTO_IPIP) 592 af = AF_INET; 593 else 594#endif 595 af = AF_INET6; 596 IPSEC_INIT_CTX(&ctx, &m, NULL, sav, af, IPSEC_ENC_AFTER); 597 if ((error = ipsec_run_hhooks(&ctx, HHOOK_TYPE_IPSEC_IN)) != 0) 598 goto bad; 599 if (skip == 0) { 600 /* 601 * We stripped outer IPv6 header. 602 * Now we should requeue decrypted packet via netisr. 603 */ 604 switch (prot) { 605#ifdef INET 606 case IPPROTO_IPIP: 607 isr_prot = NETISR_IP; 608 break; 609#endif 610 case IPPROTO_IPV6: 611 isr_prot = NETISR_IPV6; 612 break; 613 default: 614 DPRINTF(("%s: cannot handle inner ip proto %d\n", 615 __func__, prot)); 616 IPSEC_ISTAT(sproto, nopf); 617 error = EPFNOSUPPORT; 618 goto bad; 619 } 620 /* Handle virtual tunneling interfaces */ 621 if (saidx->mode == IPSEC_MODE_TUNNEL) 622 error = ipsec_if_input(m, sav, af); 623 if (error == 0) { 624 error = netisr_queue_src(isr_prot, 625 (uintptr_t)sav->spi, m); 626 if (error) { 627 IPSEC_ISTAT(sproto, qfull); 628 DPRINTF(("%s: queue full; proto %u packet" 629 " dropped\n", __func__, sproto)); 630 } 631 } 632 key_freesav(&sav); 633 return (error); 634 } 635 /* 636 * See the end of ip6_input for this logic. 637 * IPPROTO_IPV[46] case will be processed just like other ones 638 */ 639 nest = 0; 640 nxt = nxt8; 641 while (nxt != IPPROTO_DONE) { 642 if (V_ip6_hdrnestlimit && (++nest > V_ip6_hdrnestlimit)) { 643 IP6STAT_INC(ip6s_toomanyhdr); 644 error = EINVAL; 645 goto bad; 646 } 647 648 /* 649 * Protection against faulty packet - there should be 650 * more sanity checks in header chain processing. 651 */ 652 if (m->m_pkthdr.len < skip) { 653 IP6STAT_INC(ip6s_tooshort); 654 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 655 error = EINVAL; 656 goto bad; 657 } 658 /* 659 * Enforce IPsec policy checking if we are seeing last header. 660 * note that we do not visit this with protocols with pcb layer 661 * code - like udp/tcp/raw ip. 662 */ 663 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 664 ipsec6_in_reject(m, NULL)) { 665 error = EINVAL; 666 goto bad; 667 } 668 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &skip, nxt); 669 } 670 key_freesav(&sav); 671 return (0); 672bad: 673 key_freesav(&sav); 674 if (m) 675 m_freem(m); 676 return (error); 677} 678#endif /* INET6 */ 679