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_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 */ 117 static int 118 ipsec_common_input(struct mbuf *m, int skip, int protoff, int af, int sproto) 119 { 120 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 if (error != 0) 227 key_freesav(&sav); 228 return (error); 229 } 230 231 #ifdef INET 232 extern struct protosw inetsw[]; 233 234 /* 235 * IPSEC_INPUT() method implementation for IPv4. 236 * 0 - Permitted by inbound security policy for further processing. 237 * EACCES - Forbidden by inbound security policy. 238 * EINPROGRESS - consumed by IPsec. 239 */ 240 int 241 ipsec4_input(struct mbuf *m, int offset, int proto) 242 { 243 244 switch (proto) { 245 case IPPROTO_AH: 246 case IPPROTO_ESP: 247 case IPPROTO_IPCOMP: 248 /* Do inbound IPsec processing for AH/ESP/IPCOMP */ 249 ipsec_common_input(m, offset, 250 offsetof(struct ip, ip_p), AF_INET, proto); 251 return (EINPROGRESS); /* mbuf consumed by IPsec */ 252 default: 253 /* 254 * Protocols with further headers get their IPsec treatment 255 * within the protocol specific processing. 256 */ 257 if ((inetsw[ip_protox[proto]].pr_flags & PR_LASTHDR) == 0) 258 return (0); 259 /* FALLTHROUGH */ 260 }; 261 /* 262 * Enforce IPsec policy checking if we are seeing last header. 263 */ 264 if (ipsec4_in_reject(m, NULL) != 0) { 265 /* Forbidden by inbound security policy */ 266 m_freem(m); 267 return (EACCES); 268 } 269 return (0); 270 } 271 272 /* 273 * IPsec input callback for INET protocols. 274 * This routine is called as the transform callback. 275 * Takes care of filtering and other sanity checks on 276 * the processed packet. 277 */ 278 int 279 ipsec4_common_input_cb(struct mbuf *m, struct secasvar *sav, int skip, 280 int protoff) 281 { 282 char buf[IPSEC_ADDRSTRLEN]; 283 struct ipsec_ctx_data ctx; 284 struct xform_history *xh; 285 struct secasindex *saidx; 286 struct m_tag *mtag; 287 struct ip *ip; 288 int error, prot, af, sproto, isr_prot; 289 290 IPSEC_ASSERT(sav != NULL, ("null SA")); 291 IPSEC_ASSERT(sav->sah != NULL, ("null SAH")); 292 saidx = &sav->sah->saidx; 293 af = saidx->dst.sa.sa_family; 294 IPSEC_ASSERT(af == AF_INET, ("unexpected af %u", af)); 295 sproto = saidx->proto; 296 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH || 297 sproto == IPPROTO_IPCOMP, 298 ("unexpected security protocol %u", sproto)); 299 300 if (skip != 0) { 301 /* 302 * Fix IPv4 header 303 */ 304 if (m->m_len < skip && (m = m_pullup(m, skip)) == NULL) { 305 DPRINTF(("%s: processing failed for SA %s/%08lx\n", 306 __func__, ipsec_address(&sav->sah->saidx.dst, 307 buf, sizeof(buf)), (u_long) ntohl(sav->spi))); 308 IPSEC_ISTAT(sproto, hdrops); 309 error = ENOBUFS; 310 goto bad; 311 } 312 313 ip = mtod(m, struct ip *); 314 ip->ip_len = htons(m->m_pkthdr.len); 315 ip->ip_sum = 0; 316 ip->ip_sum = in_cksum(m, ip->ip_hl << 2); 317 } else { 318 ip = mtod(m, struct ip *); 319 } 320 prot = ip->ip_p; 321 /* 322 * Check that we have NAT-T enabled and apply transport mode 323 * decapsulation NAT procedure (RFC3948). 324 * Do this before invoking into the PFIL. 325 */ 326 if (sav->natt != NULL && 327 (prot == IPPROTO_UDP || prot == IPPROTO_TCP)) 328 udp_ipsec_adjust_cksum(m, sav, prot, skip); 329 330 IPSEC_INIT_CTX(&ctx, &m, sav, AF_INET, IPSEC_ENC_BEFORE); 331 if ((error = ipsec_run_hhooks(&ctx, HHOOK_TYPE_IPSEC_IN)) != 0) 332 goto bad; 333 ip = mtod(m, struct ip *); /* update pointer */ 334 335 /* IP-in-IP encapsulation */ 336 if (prot == IPPROTO_IPIP && 337 saidx->mode != IPSEC_MODE_TRANSPORT) { 338 if (m->m_pkthdr.len - skip < sizeof(struct ip)) { 339 IPSEC_ISTAT(sproto, hdrops); 340 error = EINVAL; 341 goto bad; 342 } 343 /* enc0: strip outer IPv4 header */ 344 m_striphdr(m, 0, ip->ip_hl << 2); 345 } 346 #ifdef INET6 347 /* IPv6-in-IP encapsulation. */ 348 else if (prot == IPPROTO_IPV6 && 349 saidx->mode != IPSEC_MODE_TRANSPORT) { 350 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) { 351 IPSEC_ISTAT(sproto, hdrops); 352 error = EINVAL; 353 goto bad; 354 } 355 /* enc0: strip IPv4 header, keep IPv6 header only */ 356 m_striphdr(m, 0, ip->ip_hl << 2); 357 } 358 #endif /* INET6 */ 359 else if (prot != IPPROTO_IPV6 && saidx->mode == IPSEC_MODE_ANY) { 360 /* 361 * When mode is wildcard, inner protocol is IPv6 and 362 * we have no INET6 support - drop this packet a bit later. 363 * In other cases we assume transport mode. Set prot to 364 * correctly choose netisr. 365 */ 366 prot = IPPROTO_IPIP; 367 } 368 369 /* 370 * Record what we've done to the packet (under what SA it was 371 * processed). 372 */ 373 if (sproto != IPPROTO_IPCOMP) { 374 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE, 375 sizeof(struct xform_history), M_NOWAIT); 376 if (mtag == NULL) { 377 DPRINTF(("%s: failed to get tag\n", __func__)); 378 IPSEC_ISTAT(sproto, hdrops); 379 error = ENOMEM; 380 goto bad; 381 } 382 383 xh = (struct xform_history *)(mtag + 1); 384 bcopy(&saidx->dst, &xh->dst, saidx->dst.sa.sa_len); 385 xh->spi = sav->spi; 386 xh->proto = sproto; 387 xh->mode = saidx->mode; 388 m_tag_prepend(m, mtag); 389 } 390 391 key_sa_recordxfer(sav, m); /* record data transfer */ 392 393 /* 394 * In transport mode requeue decrypted mbuf back to IPv4 protocol 395 * handler. This is necessary to correctly expose rcvif. 396 */ 397 if (saidx->mode == IPSEC_MODE_TRANSPORT) 398 prot = IPPROTO_IPIP; 399 /* 400 * Re-dispatch via software interrupt. 401 */ 402 switch (prot) { 403 case IPPROTO_IPIP: 404 isr_prot = NETISR_IP; 405 af = AF_INET; 406 break; 407 #ifdef INET6 408 case IPPROTO_IPV6: 409 isr_prot = NETISR_IPV6; 410 af = AF_INET6; 411 break; 412 #endif 413 default: 414 DPRINTF(("%s: cannot handle inner ip proto %d\n", 415 __func__, prot)); 416 IPSEC_ISTAT(sproto, nopf); 417 error = EPFNOSUPPORT; 418 goto bad; 419 } 420 421 IPSEC_INIT_CTX(&ctx, &m, sav, af, IPSEC_ENC_AFTER); 422 if ((error = ipsec_run_hhooks(&ctx, HHOOK_TYPE_IPSEC_IN)) != 0) 423 goto bad; 424 425 /* Handle virtual tunneling interfaces */ 426 if (saidx->mode == IPSEC_MODE_TUNNEL) 427 error = ipsec_if_input(m, sav, af); 428 if (error == 0) { 429 error = netisr_queue_src(isr_prot, (uintptr_t)sav->spi, m); 430 if (error) { 431 IPSEC_ISTAT(sproto, qfull); 432 DPRINTF(("%s: queue full; proto %u packet dropped\n", 433 __func__, sproto)); 434 } 435 } 436 key_freesav(&sav); 437 return (error); 438 bad: 439 key_freesav(&sav); 440 if (m != NULL) 441 m_freem(m); 442 return (error); 443 } 444 #endif /* INET */ 445 446 #ifdef INET6 447 /* 448 * IPSEC_INPUT() method implementation for IPv6. 449 * 0 - Permitted by inbound security policy for further processing. 450 * EACCES - Forbidden by inbound security policy. 451 * EINPROGRESS - consumed by IPsec. 452 */ 453 int 454 ipsec6_input(struct mbuf *m, int offset, int proto) 455 { 456 457 switch (proto) { 458 case IPPROTO_AH: 459 case IPPROTO_ESP: 460 case IPPROTO_IPCOMP: 461 /* Do inbound IPsec processing for AH/ESP/IPCOMP */ 462 ipsec_common_input(m, offset, 463 offsetof(struct ip6_hdr, ip6_nxt), AF_INET6, proto); 464 return (EINPROGRESS); /* mbuf consumed by IPsec */ 465 default: 466 /* 467 * Protocols with further headers get their IPsec treatment 468 * within the protocol specific processing. 469 */ 470 if ((inet6sw[ip6_protox[proto]].pr_flags & PR_LASTHDR) == 0) 471 return (0); 472 /* FALLTHROUGH */ 473 }; 474 /* 475 * Enforce IPsec policy checking if we are seeing last header. 476 */ 477 if (ipsec6_in_reject(m, NULL) != 0) { 478 /* Forbidden by inbound security policy */ 479 m_freem(m); 480 return (EACCES); 481 } 482 return (0); 483 } 484 485 /* 486 * IPsec input callback, called by the transform callback. Takes care of 487 * filtering and other sanity checks on the processed packet. 488 */ 489 int 490 ipsec6_common_input_cb(struct mbuf *m, struct secasvar *sav, int skip, 491 int protoff) 492 { 493 char buf[IPSEC_ADDRSTRLEN]; 494 struct ipsec_ctx_data ctx; 495 struct xform_history *xh; 496 struct secasindex *saidx; 497 struct ip6_hdr *ip6; 498 struct m_tag *mtag; 499 int prot, af, sproto; 500 int nxt, isr_prot; 501 int error, nest; 502 uint8_t nxt8; 503 504 IPSEC_ASSERT(sav != NULL, ("null SA")); 505 IPSEC_ASSERT(sav->sah != NULL, ("null SAH")); 506 saidx = &sav->sah->saidx; 507 af = saidx->dst.sa.sa_family; 508 IPSEC_ASSERT(af == AF_INET6, ("unexpected af %u", af)); 509 sproto = saidx->proto; 510 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH || 511 sproto == IPPROTO_IPCOMP, 512 ("unexpected security protocol %u", sproto)); 513 514 /* Fix IPv6 header */ 515 if (m->m_len < sizeof(struct ip6_hdr) && 516 (m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 517 518 DPRINTF(("%s: processing failed for SA %s/%08lx\n", 519 __func__, ipsec_address(&sav->sah->saidx.dst, buf, 520 sizeof(buf)), (u_long) ntohl(sav->spi))); 521 522 IPSEC_ISTAT(sproto, hdrops); 523 error = EACCES; 524 goto bad; 525 } 526 527 IPSEC_INIT_CTX(&ctx, &m, sav, af, IPSEC_ENC_BEFORE); 528 if ((error = ipsec_run_hhooks(&ctx, HHOOK_TYPE_IPSEC_IN)) != 0) 529 goto bad; 530 531 ip6 = mtod(m, struct ip6_hdr *); 532 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 533 534 /* Save protocol */ 535 m_copydata(m, protoff, 1, &nxt8); 536 prot = nxt8; 537 538 /* IPv6-in-IP encapsulation */ 539 if (prot == IPPROTO_IPV6 && 540 saidx->mode != IPSEC_MODE_TRANSPORT) { 541 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) { 542 IPSEC_ISTAT(sproto, hdrops); 543 error = EINVAL; 544 goto bad; 545 } 546 /* ip6n will now contain the inner IPv6 header. */ 547 m_striphdr(m, 0, skip); 548 skip = 0; 549 } 550 #ifdef INET 551 /* IP-in-IP encapsulation */ 552 else if (prot == IPPROTO_IPIP && 553 saidx->mode != IPSEC_MODE_TRANSPORT) { 554 if (m->m_pkthdr.len - skip < sizeof(struct ip)) { 555 IPSEC_ISTAT(sproto, hdrops); 556 error = EINVAL; 557 goto bad; 558 } 559 /* ipn will now contain the inner IPv4 header */ 560 m_striphdr(m, 0, skip); 561 skip = 0; 562 } 563 #endif /* INET */ 564 else { 565 prot = IPPROTO_IPV6; /* for correct BPF processing */ 566 } 567 568 /* 569 * Record what we've done to the packet (under what SA it was 570 * processed). 571 */ 572 if (sproto != IPPROTO_IPCOMP) { 573 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE, 574 sizeof(struct xform_history), M_NOWAIT); 575 if (mtag == NULL) { 576 DPRINTF(("%s: failed to get tag\n", __func__)); 577 IPSEC_ISTAT(sproto, hdrops); 578 error = ENOMEM; 579 goto bad; 580 } 581 582 xh = (struct xform_history *)(mtag + 1); 583 bcopy(&saidx->dst, &xh->dst, saidx->dst.sa.sa_len); 584 xh->spi = sav->spi; 585 xh->proto = sproto; 586 xh->mode = saidx->mode; 587 m_tag_prepend(m, mtag); 588 } 589 590 key_sa_recordxfer(sav, m); 591 592 #ifdef INET 593 if (prot == IPPROTO_IPIP) 594 af = AF_INET; 595 else 596 #endif 597 af = AF_INET6; 598 IPSEC_INIT_CTX(&ctx, &m, sav, af, IPSEC_ENC_AFTER); 599 if ((error = ipsec_run_hhooks(&ctx, HHOOK_TYPE_IPSEC_IN)) != 0) 600 goto bad; 601 if (skip == 0) { 602 /* 603 * We stripped outer IPv6 header. 604 * Now we should requeue decrypted packet via netisr. 605 */ 606 switch (prot) { 607 #ifdef INET 608 case IPPROTO_IPIP: 609 isr_prot = NETISR_IP; 610 break; 611 #endif 612 case IPPROTO_IPV6: 613 isr_prot = NETISR_IPV6; 614 break; 615 default: 616 DPRINTF(("%s: cannot handle inner ip proto %d\n", 617 __func__, prot)); 618 IPSEC_ISTAT(sproto, nopf); 619 error = EPFNOSUPPORT; 620 goto bad; 621 } 622 /* Handle virtual tunneling interfaces */ 623 if (saidx->mode == IPSEC_MODE_TUNNEL) 624 error = ipsec_if_input(m, sav, af); 625 if (error == 0) { 626 error = netisr_queue_src(isr_prot, 627 (uintptr_t)sav->spi, m); 628 if (error) { 629 IPSEC_ISTAT(sproto, qfull); 630 DPRINTF(("%s: queue full; proto %u packet" 631 " dropped\n", __func__, sproto)); 632 } 633 } 634 key_freesav(&sav); 635 return (error); 636 } 637 /* 638 * See the end of ip6_input for this logic. 639 * IPPROTO_IPV[46] case will be processed just like other ones 640 */ 641 nest = 0; 642 nxt = nxt8; 643 while (nxt != IPPROTO_DONE) { 644 if (V_ip6_hdrnestlimit && (++nest > V_ip6_hdrnestlimit)) { 645 IP6STAT_INC(ip6s_toomanyhdr); 646 error = EINVAL; 647 goto bad; 648 } 649 650 /* 651 * Protection against faulty packet - there should be 652 * more sanity checks in header chain processing. 653 */ 654 if (m->m_pkthdr.len < skip) { 655 IP6STAT_INC(ip6s_tooshort); 656 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 657 error = EINVAL; 658 goto bad; 659 } 660 /* 661 * Enforce IPsec policy checking if we are seeing last header. 662 * note that we do not visit this with protocols with pcb layer 663 * code - like udp/tcp/raw ip. 664 */ 665 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 666 ipsec6_in_reject(m, NULL)) { 667 error = EINVAL; 668 goto bad; 669 } 670 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &skip, nxt); 671 } 672 key_freesav(&sav); 673 return (0); 674 bad: 675 key_freesav(&sav); 676 if (m) 677 m_freem(m); 678 return (error); 679 } 680 #endif /* INET6 */ 681