ipsec_input.c revision 274755
1/* $FreeBSD: stable/10/sys/netipsec/ipsec_input.c 274755 2014-11-20 18:49:11Z 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 else 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 else if (prot != IPPROTO_IPV6 && saidx->mode == IPSEC_MODE_ANY) { 447 /* 448 * When mode is wildcard, inner protocol is IPv6 and 449 * we have no INET6 support - drop this packet a bit later. 450 * In other cases we assume transport mode and outer 451 * header was already stripped in xform_xxx_cb. 452 */ 453 prot = IPPROTO_IPIP; 454 } 455 456 /* 457 * Record what we've done to the packet (under what SA it was 458 * processed). If we've been passed an mtag, it means the packet 459 * was already processed by an ethernet/crypto combo card and 460 * thus has a tag attached with all the right information, but 461 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to 462 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type. 463 */ 464 if (mt == NULL && sproto != IPPROTO_IPCOMP) { 465 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE, 466 sizeof(struct tdb_ident), M_NOWAIT); 467 if (mtag == NULL) { 468 DPRINTF(("%s: failed to get tag\n", __func__)); 469 IPSEC_ISTAT(sproto, hdrops); 470 error = ENOMEM; 471 goto bad; 472 } 473 474 tdbi = (struct tdb_ident *)(mtag + 1); 475 bcopy(&saidx->dst, &tdbi->dst, saidx->dst.sa.sa_len); 476 tdbi->proto = sproto; 477 tdbi->spi = sav->spi; 478 /* Cache those two for enc(4) in xform_ipip. */ 479 tdbi->alg_auth = sav->alg_auth; 480 tdbi->alg_enc = sav->alg_enc; 481 482 m_tag_prepend(m, mtag); 483 } else if (mt != NULL) { 484 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE; 485 /* XXX do we need to mark m_flags??? */ 486 } 487 488 key_sa_recordxfer(sav, m); /* record data transfer */ 489 490 /* 491 * In transport mode requeue decrypted mbuf back to IPv4 protocol 492 * handler. This is necessary to correctly expose rcvif. 493 */ 494 if (saidx->mode == IPSEC_MODE_TRANSPORT) 495 prot = IPPROTO_IPIP; 496#ifdef DEV_ENC 497 /* 498 * Pass the mbuf to enc0 for bpf and pfil. 499 */ 500 if (prot == IPPROTO_IPIP) 501 ipsec_bpf(m, sav, AF_INET, ENC_IN|ENC_AFTER); 502#ifdef INET6 503 if (prot == IPPROTO_IPV6) 504 ipsec_bpf(m, sav, AF_INET6, ENC_IN|ENC_AFTER); 505#endif 506 507 if ((error = ipsec_filter(&m, PFIL_IN, ENC_IN|ENC_AFTER)) != 0) 508 return (error); 509#endif /* DEV_ENC */ 510 511 /* 512 * Re-dispatch via software interrupt. 513 */ 514 515 switch (prot) { 516 case IPPROTO_IPIP: 517 isr_prot = NETISR_IP; 518 break; 519#ifdef INET6 520 case IPPROTO_IPV6: 521 isr_prot = NETISR_IPV6; 522 break; 523#endif 524 default: 525 DPRINTF(("%s: cannot handle inner ip proto %d\n", 526 __func__, prot)); 527 IPSEC_ISTAT(sproto, nopf); 528 error = EPFNOSUPPORT; 529 goto bad; 530 } 531 532 error = netisr_queue_src(isr_prot, (uintptr_t)sav->spi, m); 533 if (error) { 534 IPSEC_ISTAT(sproto, qfull); 535 DPRINTF(("%s: queue full; proto %u packet dropped\n", 536 __func__, sproto)); 537 return error; 538 } 539 return 0; 540bad: 541 m_freem(m); 542 return error; 543} 544 545void 546ipsec4_common_ctlinput(int cmd, struct sockaddr *sa, void *v, int proto) 547{ 548 /* XXX nothing just yet */ 549} 550#endif /* INET */ 551 552#ifdef INET6 553/* IPv6 AH wrapper. */ 554int 555ipsec6_common_input(struct mbuf **mp, int *offp, int proto) 556{ 557 int l = 0; 558 int protoff; 559 struct ip6_ext ip6e; 560 561 if (*offp < sizeof(struct ip6_hdr)) { 562 DPRINTF(("%s: bad offset %u\n", __func__, *offp)); 563 return IPPROTO_DONE; 564 } else if (*offp == sizeof(struct ip6_hdr)) { 565 protoff = offsetof(struct ip6_hdr, ip6_nxt); 566 } else { 567 /* Chase down the header chain... */ 568 protoff = sizeof(struct ip6_hdr); 569 570 do { 571 protoff += l; 572 m_copydata(*mp, protoff, sizeof(ip6e), 573 (caddr_t) &ip6e); 574 575 if (ip6e.ip6e_nxt == IPPROTO_AH) 576 l = (ip6e.ip6e_len + 2) << 2; 577 else 578 l = (ip6e.ip6e_len + 1) << 3; 579 IPSEC_ASSERT(l > 0, ("l went zero or negative")); 580 } while (protoff + l < *offp); 581 582 /* Malformed packet check */ 583 if (protoff + l != *offp) { 584 DPRINTF(("%s: bad packet header chain, protoff %u, " 585 "l %u, off %u\n", __func__, protoff, l, *offp)); 586 IPSEC_ISTAT(proto, hdrops); 587 m_freem(*mp); 588 *mp = NULL; 589 return IPPROTO_DONE; 590 } 591 protoff += offsetof(struct ip6_ext, ip6e_nxt); 592 } 593 (void) ipsec_common_input(*mp, *offp, protoff, AF_INET6, proto); 594 return IPPROTO_DONE; 595} 596 597/* 598 * IPsec input callback, called by the transform callback. Takes care of 599 * filtering and other sanity checks on the processed packet. 600 */ 601int 602ipsec6_common_input_cb(struct mbuf *m, struct secasvar *sav, int skip, int protoff, 603 struct m_tag *mt) 604{ 605 int prot, af, sproto; 606 struct ip6_hdr *ip6; 607 struct m_tag *mtag; 608 struct tdb_ident *tdbi; 609 struct secasindex *saidx; 610 int nxt; 611 u_int8_t nxt8; 612 int error, nest; 613#ifdef notyet 614 char ip6buf[INET6_ADDRSTRLEN]; 615#endif 616 617 IPSEC_ASSERT(m != NULL, ("null mbuf")); 618 IPSEC_ASSERT(sav != NULL, ("null SA")); 619 IPSEC_ASSERT(sav->sah != NULL, ("null SAH")); 620 saidx = &sav->sah->saidx; 621 af = saidx->dst.sa.sa_family; 622 IPSEC_ASSERT(af == AF_INET6, ("unexpected af %u", af)); 623 sproto = saidx->proto; 624 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH || 625 sproto == IPPROTO_IPCOMP, 626 ("unexpected security protocol %u", sproto)); 627 628 /* Sanity check */ 629 if (m == NULL) { 630 DPRINTF(("%s: null mbuf", __func__)); 631 IPSEC_ISTAT(sproto, badkcr); 632 error = EINVAL; 633 goto bad; 634 } 635 636 /* Fix IPv6 header */ 637 if (m->m_len < sizeof(struct ip6_hdr) && 638 (m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 639 640 DPRINTF(("%s: processing failed for SA %s/%08lx\n", 641 __func__, ipsec_address(&sav->sah->saidx.dst), 642 (u_long) ntohl(sav->spi))); 643 644 IPSEC_ISTAT(sproto, hdrops); 645 error = EACCES; 646 goto bad; 647 } 648 649 ip6 = mtod(m, struct ip6_hdr *); 650 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 651 652 /* Save protocol */ 653 m_copydata(m, protoff, 1, &nxt8); 654 prot = nxt8; 655 656#ifdef DEV_ENC 657 encif->if_ipackets++; 658 encif->if_ibytes += m->m_pkthdr.len; 659 660 /* 661 * Pass the mbuf to enc0 for bpf and pfil. We will filter the IPIP 662 * packet later after it has been decapsulated. 663 */ 664 ipsec_bpf(m, sav, AF_INET6, ENC_IN|ENC_BEFORE); 665 666 /* XXX-BZ does not make sense. */ 667 if (prot != IPPROTO_IPIP) 668 if ((error = ipsec_filter(&m, PFIL_IN, ENC_IN|ENC_BEFORE)) != 0) 669 return (error); 670#endif /* DEV_ENC */ 671 672 /* IPv6-in-IP encapsulation */ 673 if (prot == IPPROTO_IPV6 && 674 saidx->mode != IPSEC_MODE_TRANSPORT) { 675 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) { 676 IPSEC_ISTAT(sproto, hdrops); 677 error = EINVAL; 678 goto bad; 679 } 680 /* ip6n will now contain the inner IPv6 header. */ 681 m_striphdr(m, 0, skip); 682 skip = 0; 683#ifdef notyet 684 /* 685 * Check that the inner source address is the same as 686 * the proxy address, if available. 687 */ 688 if ((saidx->proxy.sa.sa_family == AF_INET6 && 689 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) && 690 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src, 691 &saidx->proxy.sin6.sin6_addr)) || 692 (saidx->proxy.sa.sa_family != AF_INET6 && 693 saidx->proxy.sa.sa_family != 0)) { 694 695 DPRINTF(("%s: inner source address %s doesn't " 696 "correspond to expected proxy source %s, " 697 "SA %s/%08lx\n", __func__, 698 ip6_sprintf(ip6buf, &ip6n.ip6_src), 699 ipsec_address(&saidx->proxy), 700 ipsec_address(&saidx->dst), 701 (u_long) ntohl(sav->spi))); 702 703 IPSEC_ISTAT(sproto, pdrops); 704 error = EACCES; 705 goto bad; 706 } 707#endif /* notyet */ 708 } 709#ifdef INET 710 /* IP-in-IP encapsulation */ 711 else if (prot == IPPROTO_IPIP && 712 saidx->mode != IPSEC_MODE_TRANSPORT) { 713 if (m->m_pkthdr.len - skip < sizeof(struct ip)) { 714 IPSEC_ISTAT(sproto, hdrops); 715 error = EINVAL; 716 goto bad; 717 } 718 /* ipn will now contain the inner IPv4 header */ 719 m_striphdr(m, 0, skip); 720 skip = 0; 721#ifdef notyet 722 /* 723 * Check that the inner source address is the same as 724 * the proxy address, if available. 725 */ 726 if ((saidx->proxy.sa.sa_family == AF_INET && 727 saidx->proxy.sin.sin_addr.s_addr != INADDR_ANY && 728 ipn.ip_src.s_addr != saidx->proxy.sin.sin_addr.s_addr) || 729 (saidx->proxy.sa.sa_family != AF_INET && 730 saidx->proxy.sa.sa_family != 0)) { 731 732 DPRINTF(("%s: inner source address %s doesn't " 733 "correspond to expected proxy source %s, " 734 "SA %s/%08lx\n", __func__, 735 inet_ntoa4(ipn.ip_src), 736 ipsec_address(&saidx->proxy), 737 ipsec_address(&saidx->dst), 738 (u_long) ntohl(sav->spi))); 739 740 IPSEC_ISTAT(sproto, pdrops); 741 error = EACCES; 742 goto bad; 743 } 744#endif /* notyet */ 745 } 746#endif /* INET */ 747 else { 748 prot = IPPROTO_IPV6; /* for correct BPF processing */ 749 } 750 751 /* 752 * Record what we've done to the packet (under what SA it was 753 * processed). If we've been passed an mtag, it means the packet 754 * was already processed by an ethernet/crypto combo card and 755 * thus has a tag attached with all the right information, but 756 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to 757 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type. 758 */ 759 if (mt == NULL && sproto != IPPROTO_IPCOMP) { 760 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE, 761 sizeof(struct tdb_ident), M_NOWAIT); 762 if (mtag == NULL) { 763 DPRINTF(("%s: failed to get tag\n", __func__)); 764 IPSEC_ISTAT(sproto, hdrops); 765 error = ENOMEM; 766 goto bad; 767 } 768 769 tdbi = (struct tdb_ident *)(mtag + 1); 770 bcopy(&saidx->dst, &tdbi->dst, sizeof(union sockaddr_union)); 771 tdbi->proto = sproto; 772 tdbi->spi = sav->spi; 773 /* Cache those two for enc(4) in xform_ipip. */ 774 tdbi->alg_auth = sav->alg_auth; 775 tdbi->alg_enc = sav->alg_enc; 776 777 m_tag_prepend(m, mtag); 778 } else { 779 if (mt != NULL) 780 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE; 781 /* XXX do we need to mark m_flags??? */ 782 } 783 784 key_sa_recordxfer(sav, m); 785 786#ifdef DEV_ENC 787 /* 788 * Pass the mbuf to enc0 for bpf and pfil. 789 */ 790#ifdef INET 791 if (prot == IPPROTO_IPIP) 792 ipsec_bpf(m, sav, AF_INET, ENC_IN|ENC_AFTER); 793#endif 794 if (prot == IPPROTO_IPV6) 795 ipsec_bpf(m, sav, AF_INET6, ENC_IN|ENC_AFTER); 796 797 if ((error = ipsec_filter(&m, PFIL_IN, ENC_IN|ENC_AFTER)) != 0) 798 return (error); 799#endif /* DEV_ENC */ 800 /* 801 * See the end of ip6_input for this logic. 802 * IPPROTO_IPV[46] case will be processed just like other ones 803 */ 804 nest = 0; 805 nxt = nxt8; 806 while (nxt != IPPROTO_DONE) { 807 if (V_ip6_hdrnestlimit && (++nest > V_ip6_hdrnestlimit)) { 808 IP6STAT_INC(ip6s_toomanyhdr); 809 error = EINVAL; 810 goto bad; 811 } 812 813 /* 814 * Protection against faulty packet - there should be 815 * more sanity checks in header chain processing. 816 */ 817 if (m->m_pkthdr.len < skip) { 818 IP6STAT_INC(ip6s_tooshort); 819 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 820 error = EINVAL; 821 goto bad; 822 } 823 /* 824 * Enforce IPsec policy checking if we are seeing last header. 825 * note that we do not visit this with protocols with pcb layer 826 * code - like udp/tcp/raw ip. 827 */ 828 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 829 ipsec6_in_reject(m, NULL)) { 830 error = EINVAL; 831 goto bad; 832 } 833 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &skip, nxt); 834 } 835 return 0; 836bad: 837 if (m) 838 m_freem(m); 839 return error; 840} 841 842void 843esp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 844{ 845 struct ip6ctlparam *ip6cp = NULL; 846 struct mbuf *m = NULL; 847 struct ip6_hdr *ip6; 848 int off; 849 850 if (sa->sa_family != AF_INET6 || 851 sa->sa_len != sizeof(struct sockaddr_in6)) 852 return; 853 if ((unsigned)cmd >= PRC_NCMDS) 854 return; 855 856 /* if the parameter is from icmp6, decode it. */ 857 if (d != NULL) { 858 ip6cp = (struct ip6ctlparam *)d; 859 m = ip6cp->ip6c_m; 860 ip6 = ip6cp->ip6c_ip6; 861 off = ip6cp->ip6c_off; 862 } else { 863 m = NULL; 864 ip6 = NULL; 865 off = 0; /* calm gcc */ 866 } 867 868 if (ip6 != NULL) { 869 870 struct ip6ctlparam ip6cp1; 871 872 /* 873 * Notify the error to all possible sockets via pfctlinput2. 874 * Since the upper layer information (such as protocol type, 875 * source and destination ports) is embedded in the encrypted 876 * data and might have been cut, we can't directly call 877 * an upper layer ctlinput function. However, the pcbnotify 878 * function will consider source and destination addresses 879 * as well as the flow info value, and may be able to find 880 * some PCB that should be notified. 881 * Although pfctlinput2 will call esp6_ctlinput(), there is 882 * no possibility of an infinite loop of function calls, 883 * because we don't pass the inner IPv6 header. 884 */ 885 bzero(&ip6cp1, sizeof(ip6cp1)); 886 ip6cp1.ip6c_src = ip6cp->ip6c_src; 887 pfctlinput2(cmd, sa, (void *)&ip6cp1); 888 889 /* 890 * Then go to special cases that need ESP header information. 891 * XXX: We assume that when ip6 is non NULL, 892 * M and OFF are valid. 893 */ 894 895 if (cmd == PRC_MSGSIZE) { 896 struct secasvar *sav; 897 u_int32_t spi; 898 int valid; 899 900 /* check header length before using m_copydata */ 901 if (m->m_pkthdr.len < off + sizeof (struct esp)) 902 return; 903 m_copydata(m, off + offsetof(struct esp, esp_spi), 904 sizeof(u_int32_t), (caddr_t) &spi); 905 /* 906 * Check to see if we have a valid SA corresponding to 907 * the address in the ICMP message payload. 908 */ 909 sav = KEY_ALLOCSA((union sockaddr_union *)sa, 910 IPPROTO_ESP, spi); 911 valid = (sav != NULL); 912 if (sav) 913 KEY_FREESAV(&sav); 914 915 /* XXX Further validation? */ 916 917 /* 918 * Depending on whether the SA is "valid" and 919 * routing table size (mtudisc_{hi,lo}wat), we will: 920 * - recalcurate the new MTU and create the 921 * corresponding routing entry, or 922 * - ignore the MTU change notification. 923 */ 924 icmp6_mtudisc_update(ip6cp, valid); 925 } 926 } else { 927 /* we normally notify any pcb here */ 928 } 929} 930#endif /* INET6 */ 931