1 /* $NetBSD: ipsec_input.c,v 1.29 2012/01/25 21:58:10 drochner Exp $ */ 2 /* $FreeBSD: /usr/local/www/cvsroot/FreeBSD/src/sys/netipsec/ipsec_input.c,v 1.2.4.2 2003/03/28 20:32:53 sam Exp $ */ 3 /* $OpenBSD: ipsec_input.c,v 1.63 2003/02/20 18:35:43 deraadt Exp $ */ 4 5 /* 6 * The authors of this code are John Ioannidis (ji@tla.org), 7 * Angelos D. Keromytis (kermit@csd.uch.gr) and 8 * Niels Provos (provos@physnet.uni-hamburg.de). 9 * 10 * This code was written by John Ioannidis for BSD/OS in Athens, Greece, 11 * in November 1995. 12 * 13 * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996, 14 * by Angelos D. Keromytis. 15 * 16 * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis 17 * and Niels Provos. 18 * 19 * Additional features in 1999 by Angelos D. Keromytis. 20 * 21 * Copyright (C) 1995, 1996, 1997, 1998, 1999 by John Ioannidis, 22 * Angelos D. Keromytis and Niels Provos. 23 * Copyright (c) 2001, Angelos D. Keromytis. 24 * 25 * Permission to use, copy, and modify this software with or without fee 26 * is hereby granted, provided that this entire notice is included in 27 * all copies of any software which is or includes a copy or 28 * modification of this software. 29 * You may use this code under the GNU public license if you so wish. Please 30 * contribute changes back to the authors under this freer than GPL license 31 * so that we may further the use of strong encryption without limitations to 32 * all. 33 * 34 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR 35 * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY 36 * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE 37 * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR 38 * PURPOSE. 39 */ 40 41 #include <sys/cdefs.h> 42 __KERNEL_RCSID(0, "$NetBSD: ipsec_input.c,v 1.29 2012/01/25 21:58:10 drochner Exp $"); 43 44 /* 45 * IPsec input processing. 46 */ 47 48 #include "opt_inet.h" 49 #ifdef __FreeBSD__ 50 #include "opt_inet6.h" 51 #endif 52 #include "opt_ipsec.h" 53 54 #include <sys/param.h> 55 #include <sys/systm.h> 56 #include <sys/malloc.h> 57 #include <sys/mbuf.h> 58 #include <sys/domain.h> 59 #include <sys/protosw.h> 60 #include <sys/socket.h> 61 #include <sys/errno.h> 62 #include <sys/syslog.h> 63 64 #include <net/if.h> 65 #include <net/route.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 #include <netinet/in_proto.h> 73 74 #include <netinet/ip6.h> 75 #ifdef INET6 76 #include <netinet6/ip6_var.h> 77 #include <netinet6/ip6_private.h> 78 #include <netinet6/scope6_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 #include <netipsec/ipsec_private.h> 87 #ifdef INET6 88 #include <netipsec/ipsec6.h> 89 #endif 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 98 #include <netipsec/xform.h> 99 #include <netinet6/ip6protosw.h> 100 101 #include <netipsec/ipsec_osdep.h> 102 103 #include <net/net_osdep.h> 104 105 #define IPSEC_ISTAT(p, x, y, z) \ 106 do { \ 107 switch (p) { \ 108 case IPPROTO_ESP: \ 109 ESP_STATINC(x); \ 110 break; \ 111 case IPPROTO_AH: \ 112 AH_STATINC(y); \ 113 break; \ 114 default: \ 115 IPCOMP_STATINC(z); \ 116 break; \ 117 } \ 118 } while (/*CONSTCOND*/0) 119 120 /* 121 * ipsec_common_input gets called when an IPsec-protected packet 122 * is received by IPv4 or IPv6. It's job is to find the right SA 123 # and call the appropriate transform. The transform callback 124 * takes care of further processing (like ingress filtering). 125 */ 126 static int 127 ipsec_common_input(struct mbuf *m, int skip, int protoff, int af, int sproto) 128 { 129 union sockaddr_union dst_address; 130 struct secasvar *sav; 131 u_int32_t spi; 132 u_int16_t sport = 0; 133 u_int16_t dport = 0; 134 int s, error; 135 #ifdef IPSEC_NAT_T 136 struct m_tag * tag = NULL; 137 #endif 138 139 IPSEC_ISTAT(sproto, ESP_STAT_INPUT, AH_STAT_INPUT, 140 IPCOMP_STAT_INPUT); 141 142 IPSEC_ASSERT(m != NULL, ("ipsec_common_input: null packet")); 143 144 if ((sproto == IPPROTO_ESP && !esp_enable) || 145 (sproto == IPPROTO_AH && !ah_enable) || 146 (sproto == IPPROTO_IPCOMP && !ipcomp_enable)) { 147 m_freem(m); 148 IPSEC_ISTAT(sproto, ESP_STAT_PDROPS, AH_STAT_PDROPS, 149 IPCOMP_STAT_PDROPS); 150 return EOPNOTSUPP; 151 } 152 153 if (m->m_pkthdr.len - skip < 2 * sizeof (u_int32_t)) { 154 m_freem(m); 155 IPSEC_ISTAT(sproto, ESP_STAT_HDROPS, AH_STAT_HDROPS, 156 IPCOMP_STAT_HDROPS); 157 DPRINTF(("ipsec_common_input: packet too small\n")); 158 return EINVAL; 159 } 160 161 /* Retrieve the SPI from the relevant IPsec header */ 162 if (sproto == IPPROTO_ESP) 163 m_copydata(m, skip, sizeof(u_int32_t), &spi); 164 else if (sproto == IPPROTO_AH) 165 m_copydata(m, skip + sizeof(u_int32_t), sizeof(u_int32_t), &spi); 166 else if (sproto == IPPROTO_IPCOMP) { 167 u_int16_t cpi; 168 m_copydata(m, skip + sizeof(u_int16_t), sizeof(u_int16_t), &cpi); 169 spi = ntohl(htons(cpi)); 170 } else { 171 panic("ipsec_common_input called with bad protocol number :" 172 "%d\n", sproto); 173 } 174 175 176 #ifdef IPSEC_NAT_T 177 /* find the source port for NAT-T */ 178 if ((tag = m_tag_find(m, PACKET_TAG_IPSEC_NAT_T_PORTS, NULL))) { 179 sport = ((u_int16_t *)(tag + 1))[0]; 180 dport = ((u_int16_t *)(tag + 1))[1]; 181 } 182 #endif 183 184 /* 185 * Find the SA and (indirectly) call the appropriate 186 * kernel crypto routine. The resulting mbuf chain is a valid 187 * IP packet ready to go through input processing. 188 */ 189 memset(&dst_address, 0, sizeof (dst_address)); 190 dst_address.sa.sa_family = af; 191 switch (af) { 192 #ifdef INET 193 case AF_INET: 194 dst_address.sin.sin_len = sizeof(struct sockaddr_in); 195 m_copydata(m, offsetof(struct ip, ip_dst), 196 sizeof(struct in_addr), 197 &dst_address.sin.sin_addr); 198 break; 199 #endif /* INET */ 200 #ifdef INET6 201 case AF_INET6: 202 dst_address.sin6.sin6_len = sizeof(struct sockaddr_in6); 203 m_copydata(m, offsetof(struct ip6_hdr, ip6_dst), 204 sizeof(struct in6_addr), 205 &dst_address.sin6.sin6_addr); 206 if (sa6_recoverscope(&dst_address.sin6)) { 207 m_freem(m); 208 return EINVAL; 209 } 210 break; 211 #endif /* INET6 */ 212 default: 213 DPRINTF(("ipsec_common_input: unsupported protocol " 214 "family %u\n", af)); 215 m_freem(m); 216 IPSEC_ISTAT(sproto, ESP_STAT_NOPF, AH_STAT_NOPF, 217 IPCOMP_STAT_NOPF); 218 return EPFNOSUPPORT; 219 } 220 221 s = splsoftnet(); 222 223 /* NB: only pass dst since key_allocsa follows RFC2401 */ 224 sav = KEY_ALLOCSA(&dst_address, sproto, spi, sport, dport); 225 if (sav == NULL) { 226 DPRINTF(("ipsec_common_input: no key association found for" 227 " SA %s/%08lx/%u/%u\n", 228 ipsec_address(&dst_address), 229 (u_long) ntohl(spi), sproto, ntohs(dport))); 230 IPSEC_ISTAT(sproto, ESP_STAT_NOTDB, AH_STAT_NOTDB, 231 IPCOMP_STAT_NOTDB); 232 splx(s); 233 m_freem(m); 234 return ENOENT; 235 } 236 237 if (sav->tdb_xform == NULL) { 238 DPRINTF(("ipsec_common_input: attempted to use uninitialized" 239 " SA %s/%08lx/%u\n", 240 ipsec_address(&dst_address), 241 (u_long) ntohl(spi), sproto)); 242 IPSEC_ISTAT(sproto, ESP_STAT_NOXFORM, AH_STAT_NOXFORM, 243 IPCOMP_STAT_NOXFORM); 244 KEY_FREESAV(&sav); 245 splx(s); 246 m_freem(m); 247 return ENXIO; 248 } 249 250 /* 251 * Call appropriate transform and return -- callback takes care of 252 * everything else. 253 */ 254 error = (*sav->tdb_xform->xf_input)(m, sav, skip, protoff); 255 KEY_FREESAV(&sav); 256 splx(s); 257 return error; 258 } 259 260 #ifdef INET 261 /* 262 * Common input handler for IPv4 AH, ESP, and IPCOMP. 263 */ 264 void 265 ipsec4_common_input(struct mbuf *m, ...) 266 { 267 va_list ap; 268 int off, nxt; 269 270 va_start(ap, m); 271 off = va_arg(ap, int); 272 nxt = va_arg(ap, int); 273 va_end(ap); 274 275 (void) ipsec_common_input(m, off, offsetof(struct ip, ip_p), 276 AF_INET, nxt); 277 } 278 279 /* 280 * IPsec input callback for INET protocols. 281 * This routine is called as the transform callback. 282 * Takes care of filtering and other sanity checks on 283 * the processed packet. 284 */ 285 int 286 ipsec4_common_input_cb(struct mbuf *m, struct secasvar *sav, 287 int skip, int protoff, struct m_tag *mt) 288 { 289 int prot, af, sproto; 290 struct ip *ip; 291 struct m_tag *mtag; 292 struct tdb_ident *tdbi; 293 struct secasindex *saidx; 294 int error; 295 296 IPSEC_SPLASSERT_SOFTNET("ipsec4_common_input_cb"); 297 298 IPSEC_ASSERT(m != NULL, ("ipsec4_common_input_cb: null mbuf")); 299 IPSEC_ASSERT(sav != NULL, ("ipsec4_common_input_cb: null SA")); 300 IPSEC_ASSERT(sav->sah != NULL, ("ipsec4_common_input_cb: null SAH")); 301 saidx = &sav->sah->saidx; 302 af = saidx->dst.sa.sa_family; 303 IPSEC_ASSERT(af == AF_INET, ("ipsec4_common_input_cb: unexpected af %u",af)); 304 sproto = saidx->proto; 305 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH || 306 sproto == IPPROTO_IPCOMP, 307 ("ipsec4_common_input_cb: unexpected security protocol %u", 308 sproto)); 309 310 /* Sanity check */ 311 if (m == NULL) { 312 DPRINTF(("ipsec4_common_input_cb: null mbuf")); 313 IPSEC_ISTAT(sproto, ESP_STAT_BADKCR, AH_STAT_BADKCR, 314 IPCOMP_STAT_BADKCR); 315 KEY_FREESAV(&sav); 316 return EINVAL; 317 } 318 319 /* Fix IPv4 header */ 320 if (m->m_len < skip && (m = m_pullup(m, skip)) == NULL) { 321 DPRINTF(("ipsec4_common_input_cb: processing failed " 322 "for SA %s/%08lx\n", 323 ipsec_address(&sav->sah->saidx.dst), 324 (u_long) ntohl(sav->spi))); 325 IPSEC_ISTAT(sproto, ESP_STAT_HDROPS, AH_STAT_HDROPS, 326 IPCOMP_STAT_HDROPS); 327 error = ENOBUFS; 328 goto bad; 329 } 330 331 ip = mtod(m, struct ip *); 332 ip->ip_len = htons(m->m_pkthdr.len); 333 prot = ip->ip_p; 334 335 /* IP-in-IP encapsulation */ 336 if (prot == IPPROTO_IPIP) { 337 struct ip ipn; 338 339 /* ipn will now contain the inner IPv4 header */ 340 m_copydata(m, ip->ip_hl << 2, sizeof(struct ip), &ipn); 341 342 #ifdef notyet 343 /* XXX PROXY address isn't recorded in SAH */ 344 /* 345 * Check that the inner source address is the same as 346 * the proxy address, if available. 347 */ 348 if ((saidx->proxy.sa.sa_family == AF_INET && 349 saidx->proxy.sin.sin_addr.s_addr != 350 INADDR_ANY && 351 ipn.ip_src.s_addr != 352 saidx->proxy.sin.sin_addr.s_addr) || 353 (saidx->proxy.sa.sa_family != AF_INET && 354 saidx->proxy.sa.sa_family != 0)) { 355 356 DPRINTF(("ipsec4_common_input_cb: inner " 357 "source address %s doesn't correspond to " 358 "expected proxy source %s, SA %s/%08lx\n", 359 inet_ntoa4(ipn.ip_src), 360 ipsp_address(saidx->proxy), 361 ipsp_address(saidx->dst), 362 (u_long) ntohl(sav->spi))); 363 364 IPSEC_ISTAT(sproto, ESP_STAT_PDROPS, 365 AH_STAT_PDROPS, 366 IPCOMP_STAT_PDROPS); 367 error = EACCES; 368 goto bad; 369 } 370 #endif /*XXX*/ 371 } 372 #if INET6 373 /* IPv6-in-IP encapsulation. */ 374 if (prot == IPPROTO_IPV6) { 375 struct ip6_hdr ip6n; 376 377 /* ip6n will now contain the inner IPv6 header. */ 378 m_copydata(m, ip->ip_hl << 2, sizeof(struct ip6_hdr), &ip6n); 379 380 #ifdef notyet 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_INET6 && 386 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) && 387 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src, 388 &saidx->proxy.sin6.sin6_addr)) || 389 (saidx->proxy.sa.sa_family != AF_INET6 && 390 saidx->proxy.sa.sa_family != 0)) { 391 392 DPRINTF(("ipsec4_common_input_cb: inner " 393 "source address %s doesn't correspond to " 394 "expected proxy source %s, SA %s/%08lx\n", 395 ip6_sprintf(&ip6n.ip6_src), 396 ipsec_address(&saidx->proxy), 397 ipsec_address(&saidx->dst), 398 (u_long) ntohl(sav->spi))); 399 400 IPSEC_ISTAT(sproto, ESP_STAT_PDROPS, 401 AH_STAT_PDROPS, 402 IPCOMP_STAT_PDROPS); 403 error = EACCES; 404 goto bad; 405 } 406 #endif /*XXX*/ 407 } 408 #endif /* INET6 */ 409 410 /* 411 * Record what we've done to the packet (under what SA it was 412 * processed). If we've been passed an mtag, it means the packet 413 * was already processed by an ethernet/crypto combo card and 414 * thus has a tag attached with all the right information, but 415 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to 416 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type. 417 */ 418 if (mt == NULL && sproto != IPPROTO_IPCOMP) { 419 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE, 420 sizeof(struct tdb_ident), M_NOWAIT); 421 if (mtag == NULL) { 422 DPRINTF(("ipsec4_common_input_cb: failed to get tag\n")); 423 IPSEC_ISTAT(sproto, ESP_STAT_HDROPS, 424 AH_STAT_HDROPS, IPCOMP_STAT_HDROPS); 425 error = ENOMEM; 426 goto bad; 427 } 428 429 tdbi = (struct tdb_ident *)(mtag + 1); 430 memcpy(&tdbi->dst, &saidx->dst, saidx->dst.sa.sa_len); 431 tdbi->proto = sproto; 432 tdbi->spi = sav->spi; 433 434 m_tag_prepend(m, mtag); 435 } else { 436 if (mt != NULL) 437 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE; 438 /* XXX do we need to mark m_flags??? */ 439 } 440 441 key_sa_recordxfer(sav, m); /* record data transfer */ 442 443 if ((inetsw[ip_protox[prot]].pr_flags & PR_LASTHDR) != 0 && 444 ipsec4_in_reject(m, NULL)) { 445 error = EINVAL; 446 goto bad; 447 } 448 (*inetsw[ip_protox[prot]].pr_input)(m, skip, prot); 449 return 0; 450 bad: 451 m_freem(m); 452 return error; 453 } 454 #endif /* INET */ 455 456 #ifdef INET6 457 /* IPv6 AH wrapper. */ 458 int 459 ipsec6_common_input(struct mbuf **mp, int *offp, int proto) 460 { 461 int l = 0; 462 int protoff, nxt; 463 struct ip6_ext ip6e; 464 465 if (*offp < sizeof(struct ip6_hdr)) { 466 DPRINTF(("ipsec6_common_input: bad offset %u\n", *offp)); 467 IPSEC_ISTAT(proto, ESP_STAT_HDROPS, AH_STAT_HDROPS, 468 IPCOMP_STAT_HDROPS); 469 m_freem(*mp); 470 return IPPROTO_DONE; 471 } else if (*offp == sizeof(struct ip6_hdr)) { 472 protoff = offsetof(struct ip6_hdr, ip6_nxt); 473 } else { 474 /* Chase down the header chain... */ 475 protoff = sizeof(struct ip6_hdr); 476 nxt = (mtod(*mp, struct ip6_hdr *))->ip6_nxt; 477 478 do { 479 protoff += l; 480 m_copydata(*mp, protoff, sizeof(ip6e), &ip6e); 481 482 if (nxt == IPPROTO_AH) 483 l = (ip6e.ip6e_len + 2) << 2; 484 else 485 l = (ip6e.ip6e_len + 1) << 3; 486 IPSEC_ASSERT(l > 0, 487 ("ipsec6_common_input: l went zero or negative")); 488 489 nxt = ip6e.ip6e_nxt; 490 } while (protoff + l < *offp); 491 492 /* Malformed packet check */ 493 if (protoff + l != *offp) { 494 DPRINTF(("ipsec6_common_input: bad packet header chain, " 495 "protoff %u, l %u, off %u\n", protoff, l, *offp)); 496 IPSEC_ISTAT(proto, ESP_STAT_HDROPS, 497 AH_STAT_HDROPS, 498 IPCOMP_STAT_HDROPS); 499 m_freem(*mp); 500 *mp = NULL; 501 return IPPROTO_DONE; 502 } 503 protoff += offsetof(struct ip6_ext, ip6e_nxt); 504 } 505 (void) ipsec_common_input(*mp, *offp, protoff, AF_INET6, proto); 506 return IPPROTO_DONE; 507 } 508 509 /* 510 * NB: ipsec_netbsd.c has a duplicate definition of esp6_ctlinput(), 511 * with slightly ore recent multicast tests. These should be merged. 512 * For now, ifdef accordingly. 513 */ 514 #ifdef __FreeBSD__ 515 void 516 esp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 517 { 518 if (sa->sa_family != AF_INET6 || 519 sa->sa_len != sizeof(struct sockaddr_in6)) 520 return; 521 if ((unsigned)cmd >= PRC_NCMDS) 522 return; 523 524 /* if the parameter is from icmp6, decode it. */ 525 if (d != NULL) { 526 struct ip6ctlparam *ip6cp = (struct ip6ctlparam *)d; 527 struct mbuf *m = ip6cp->ip6c_m; 528 int off = ip6cp->ip6c_off; 529 530 struct ip6ctlparam ip6cp1; 531 532 /* 533 * Notify the error to all possible sockets via pfctlinput2. 534 * Since the upper layer information (such as protocol type, 535 * source and destination ports) is embedded in the encrypted 536 * data and might have been cut, we can't directly call 537 * an upper layer ctlinput function. However, the pcbnotify 538 * function will consider source and destination addresses 539 * as well as the flow info value, and may be able to find 540 * some PCB that should be notified. 541 * Although pfctlinput2 will call esp6_ctlinput(), there is 542 * no possibility of an infinite loop of function calls, 543 * because we don't pass the inner IPv6 header. 544 */ 545 memset(&ip6cp1, 0, sizeof(ip6cp1)); 546 ip6cp1.ip6c_src = ip6cp->ip6c_src; 547 pfctlinput2(cmd, sa, &ip6cp1); 548 549 /* 550 * Then go to special cases that need ESP header information. 551 * XXX: We assume that when ip6 is non NULL, 552 * M and OFF are valid. 553 */ 554 555 if (cmd == PRC_MSGSIZE) { 556 struct secasvar *sav; 557 u_int32_t spi; 558 int valid; 559 560 /* check header length before using m_copydata */ 561 if (m->m_pkthdr.len < off + sizeof (struct esp)) 562 return; 563 m_copydata(m, off + offsetof(struct esp, esp_spi), 564 sizeof(u_int32_t), &spi); 565 /* 566 * Check to see if we have a valid SA corresponding to 567 * the address in the ICMP message payload. 568 */ 569 sav = KEY_ALLOCSA((union sockaddr_union *)sa, 570 IPPROTO_ESP, spi); 571 valid = (sav != NULL); 572 if (sav) 573 KEY_FREESAV(&sav); 574 575 /* XXX Further validation? */ 576 577 /* 578 * Depending on whether the SA is "valid" and 579 * routing table size (mtudisc_{hi,lo}wat), we will: 580 * - recalcurate the new MTU and create the 581 * corresponding routing entry, or 582 * - ignore the MTU change notification. 583 */ 584 icmp6_mtudisc_update(ip6cp, valid); 585 } 586 } else { 587 /* we normally notify any pcb here */ 588 } 589 } 590 #endif /* __FreeBSD__ */ 591 592 extern const struct ip6protosw inet6sw[]; 593 extern u_char ip6_protox[]; 594 595 /* 596 * IPsec input callback, called by the transform callback. Takes care of 597 * filtering and other sanity checks on the processed packet. 598 */ 599 int 600 ipsec6_common_input_cb(struct mbuf *m, struct secasvar *sav, int skip, int protoff, 601 struct m_tag *mt) 602 { 603 int af, sproto; 604 struct ip6_hdr *ip6; 605 struct m_tag *mtag; 606 struct tdb_ident *tdbi; 607 struct secasindex *saidx; 608 int nxt; 609 u_int8_t prot, nxt8; 610 int error, nest; 611 612 IPSEC_ASSERT(m != NULL, ("ipsec6_common_input_cb: null mbuf")); 613 IPSEC_ASSERT(sav != NULL, ("ipsec6_common_input_cb: null SA")); 614 IPSEC_ASSERT(sav->sah != NULL, ("ipsec6_common_input_cb: null SAH")); 615 saidx = &sav->sah->saidx; 616 af = saidx->dst.sa.sa_family; 617 IPSEC_ASSERT(af == AF_INET6, 618 ("ipsec6_common_input_cb: unexpected af %u", af)); 619 sproto = saidx->proto; 620 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH || 621 sproto == IPPROTO_IPCOMP, 622 ("ipsec6_common_input_cb: unexpected security protocol %u", 623 sproto)); 624 625 /* Sanity check */ 626 if (m == NULL) { 627 DPRINTF(("ipsec6_common_input_cb: null mbuf")); 628 IPSEC_ISTAT(sproto, ESP_STAT_BADKCR, AH_STAT_BADKCR, 629 IPCOMP_STAT_BADKCR); 630 error = EINVAL; 631 goto bad; 632 } 633 634 /* Fix IPv6 header */ 635 if (m->m_len < sizeof(struct ip6_hdr) && 636 (m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 637 638 DPRINTF(("ipsec6_common_input_cb: processing failed " 639 "for SA %s/%08lx\n", ipsec_address(&sav->sah->saidx.dst), 640 (u_long) ntohl(sav->spi))); 641 642 IPSEC_ISTAT(sproto, ESP_STAT_HDROPS, AH_STAT_HDROPS, 643 IPCOMP_STAT_HDROPS); 644 error = EACCES; 645 goto bad; 646 } 647 648 ip6 = mtod(m, struct ip6_hdr *); 649 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 650 651 /* Save protocol */ 652 m_copydata(m, protoff, 1, &prot); 653 654 #ifdef INET 655 /* IP-in-IP encapsulation */ 656 if (prot == IPPROTO_IPIP) { 657 struct ip ipn; 658 659 /* ipn will now contain the inner IPv4 header */ 660 m_copydata(m, skip, sizeof(struct ip), &ipn); 661 662 #ifdef notyet 663 /* 664 * Check that the inner source address is the same as 665 * the proxy address, if available. 666 */ 667 if ((saidx->proxy.sa.sa_family == AF_INET && 668 saidx->proxy.sin.sin_addr.s_addr != INADDR_ANY && 669 ipn.ip_src.s_addr != saidx->proxy.sin.sin_addr.s_addr) || 670 (saidx->proxy.sa.sa_family != AF_INET && 671 saidx->proxy.sa.sa_family != 0)) { 672 673 DPRINTF(("ipsec6_common_input_cb: inner " 674 "source address %s doesn't correspond to " 675 "expected proxy source %s, SA %s/%08lx\n", 676 inet_ntoa4(ipn.ip_src), 677 ipsec_address(&saidx->proxy), 678 ipsec_address(&saidx->dst), 679 (u_long) ntohl(sav->spi))); 680 681 IPSEC_ISTAT(sproto, ESP_STAT_PDROPS, 682 AH_STAT_PDROPS, IPCOMP_STAT_PDROPS); 683 error = EACCES; 684 goto bad; 685 } 686 #endif /*XXX*/ 687 } 688 #endif /* INET */ 689 690 /* IPv6-in-IP encapsulation */ 691 if (prot == IPPROTO_IPV6) { 692 struct ip6_hdr ip6n; 693 694 /* ip6n will now contain the inner IPv6 header. */ 695 m_copydata(m, skip, sizeof(struct ip6_hdr), &ip6n); 696 697 #ifdef notyet 698 /* 699 * Check that the inner source address is the same as 700 * the proxy address, if available. 701 */ 702 if ((saidx->proxy.sa.sa_family == AF_INET6 && 703 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) && 704 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src, 705 &saidx->proxy.sin6.sin6_addr)) || 706 (saidx->proxy.sa.sa_family != AF_INET6 && 707 saidx->proxy.sa.sa_family != 0)) { 708 709 DPRINTF(("ipsec6_common_input_cb: inner " 710 "source address %s doesn't correspond to " 711 "expected proxy source %s, SA %s/%08lx\n", 712 ip6_sprintf(&ip6n.ip6_src), 713 ipsec_address(&saidx->proxy), 714 ipsec_address(&saidx->dst), 715 (u_long) ntohl(sav->spi))); 716 717 IPSEC_ISTAT(sproto, ESP_STAT_PDROPS, 718 AH_STAT_PDROPS, IPCOMP_STAT_PDROPS); 719 error = EACCES; 720 goto bad; 721 } 722 #endif /*XXX*/ 723 } 724 725 /* 726 * Record what we've done to the packet (under what SA it was 727 * processed). If we've been passed an mtag, it means the packet 728 * was already processed by an ethernet/crypto combo card and 729 * thus has a tag attached with all the right information, but 730 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to 731 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type. 732 */ 733 if (mt == NULL && sproto != IPPROTO_IPCOMP) { 734 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE, 735 sizeof(struct tdb_ident), M_NOWAIT); 736 if (mtag == NULL) { 737 DPRINTF(("ipsec_common_input_cb: failed to " 738 "get tag\n")); 739 IPSEC_ISTAT(sproto, ESP_STAT_HDROPS, 740 AH_STAT_HDROPS, IPCOMP_STAT_HDROPS); 741 error = ENOMEM; 742 goto bad; 743 } 744 745 tdbi = (struct tdb_ident *)(mtag + 1); 746 memcpy(&tdbi->dst, &saidx->dst, sizeof(union sockaddr_union)); 747 tdbi->proto = sproto; 748 tdbi->spi = sav->spi; 749 750 m_tag_prepend(m, mtag); 751 } else { 752 if (mt != NULL) 753 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE; 754 /* XXX do we need to mark m_flags??? */ 755 } 756 757 key_sa_recordxfer(sav, m); 758 759 /* Retrieve new protocol */ 760 m_copydata(m, protoff, sizeof(u_int8_t), &nxt8); 761 762 /* 763 * See the end of ip6_input for this logic. 764 * IPPROTO_IPV[46] case will be processed just like other ones 765 */ 766 nest = 0; 767 nxt = nxt8; 768 while (nxt != IPPROTO_DONE) { 769 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 770 IP6_STATINC(IP6_STAT_TOOMANYHDR); 771 error = EINVAL; 772 goto bad; 773 } 774 775 /* 776 * Protection against faulty packet - there should be 777 * more sanity checks in header chain processing. 778 */ 779 if (m->m_pkthdr.len < skip) { 780 IP6_STATINC(IP6_STAT_TOOSHORT); 781 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 782 error = EINVAL; 783 goto bad; 784 } 785 /* 786 * Enforce IPsec policy checking if we are seeing last header. 787 * note that we do not visit this with protocols with pcb layer 788 * code - like udp/tcp/raw ip. 789 */ 790 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 791 ipsec6_in_reject(m, NULL)) { 792 error = EINVAL; 793 goto bad; 794 } 795 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &skip, nxt); 796 } 797 return 0; 798 bad: 799 if (m) 800 m_freem(m); 801 return error; 802 } 803 #endif /* INET6 */ 804