1 /* $NetBSD: ipsec_input.c,v 1.17 2007/06/27 20:38:33 degroote 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 1.17 2007/06/27 20:38:33 degroote 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 #include <net/netisr.h> 67 68 #include <netinet/in.h> 69 #include <netinet/in_systm.h> 70 #include <netinet/ip.h> 71 #include <netinet/ip_var.h> 72 #include <netinet/in_var.h> 73 74 #include <netinet/ip6.h> 75 #ifdef INET6 76 #include <netinet6/ip6_var.h> 77 #endif 78 #include <netinet/in_pcb.h> 79 #ifdef INET6 80 #include <netinet/icmp6.h> 81 #endif 82 83 #include <netipsec/ipsec.h> 84 #ifdef INET6 85 #include <netipsec/ipsec6.h> 86 #endif 87 #include <netipsec/ah_var.h> 88 #include <netipsec/esp.h> 89 #include <netipsec/esp_var.h> 90 #include <netipsec/ipcomp_var.h> 91 92 #include <netipsec/key.h> 93 #include <netipsec/keydb.h> 94 95 #include <netipsec/xform.h> 96 #include <netinet6/ip6protosw.h> 97 98 #include <netipsec/ipsec_osdep.h> 99 100 #include <machine/stdarg.h> 101 102 #include <net/net_osdep.h> 103 104 #define IPSEC_ISTAT(p,x,y,z) ((p) == IPPROTO_ESP ? (x)++ : \ 105 (p) == IPPROTO_AH ? (y)++ : (z)++) 106 107 /* 108 * ipsec_common_input gets called when an IPsec-protected packet 109 * is received by IPv4 or IPv6. It's job is to find the right SA 110 # and call the appropriate transform. The transform callback 111 * takes care of further processing (like ingress filtering). 112 */ 113 static int 114 ipsec_common_input(struct mbuf *m, int skip, int protoff, int af, int sproto) 115 { 116 union sockaddr_union dst_address; 117 struct secasvar *sav; 118 u_int32_t spi; 119 u_int16_t sport = 0; 120 u_int16_t dport = 0; 121 int s, error; 122 #ifdef IPSEC_NAT_T 123 struct m_tag * tag = NULL; 124 #endif 125 126 IPSEC_ISTAT(sproto, espstat.esps_input, ahstat.ahs_input, 127 ipcompstat.ipcomps_input); 128 129 IPSEC_ASSERT(m != NULL, ("ipsec_common_input: null packet")); 130 131 if ((sproto == IPPROTO_ESP && !esp_enable) || 132 (sproto == IPPROTO_AH && !ah_enable) || 133 (sproto == IPPROTO_IPCOMP && !ipcomp_enable)) { 134 m_freem(m); 135 IPSEC_ISTAT(sproto, espstat.esps_pdrops, ahstat.ahs_pdrops, 136 ipcompstat.ipcomps_pdrops); 137 return EOPNOTSUPP; 138 } 139 140 if (m->m_pkthdr.len - skip < 2 * sizeof (u_int32_t)) { 141 m_freem(m); 142 IPSEC_ISTAT(sproto, espstat.esps_hdrops, ahstat.ahs_hdrops, 143 ipcompstat.ipcomps_hdrops); 144 DPRINTF(("ipsec_common_input: packet too small\n")); 145 return EINVAL; 146 } 147 148 /* Retrieve the SPI from the relevant IPsec header */ 149 if (sproto == IPPROTO_ESP) 150 m_copydata(m, skip, sizeof(u_int32_t), &spi); 151 else if (sproto == IPPROTO_AH) 152 m_copydata(m, skip + sizeof(u_int32_t), sizeof(u_int32_t), &spi); 153 else if (sproto == IPPROTO_IPCOMP) { 154 u_int16_t cpi; 155 m_copydata(m, skip + sizeof(u_int16_t), sizeof(u_int16_t), &cpi); 156 spi = ntohl(htons(cpi)); 157 } else { 158 panic("ipsec_common_input called with bad protocol number :" 159 "%d\n", sproto); 160 } 161 162 163 #ifdef IPSEC_NAT_T 164 /* find the source port for NAT-T */ 165 if ((tag = m_tag_find(m, PACKET_TAG_IPSEC_NAT_T_PORTS, NULL))) { 166 sport = ((u_int16_t *)(tag + 1))[0]; 167 dport = ((u_int16_t *)(tag + 1))[1]; 168 } 169 #endif 170 171 /* 172 * Find the SA and (indirectly) call the appropriate 173 * kernel crypto routine. The resulting mbuf chain is a valid 174 * IP packet ready to go through input processing. 175 */ 176 bzero(&dst_address, sizeof (dst_address)); 177 dst_address.sa.sa_family = af; 178 switch (af) { 179 #ifdef INET 180 case AF_INET: 181 dst_address.sin.sin_len = sizeof(struct sockaddr_in); 182 m_copydata(m, offsetof(struct ip, ip_dst), 183 sizeof(struct in_addr), 184 &dst_address.sin.sin_addr); 185 break; 186 #endif /* INET */ 187 #ifdef INET6 188 case AF_INET6: 189 dst_address.sin6.sin6_len = sizeof(struct sockaddr_in6); 190 m_copydata(m, offsetof(struct ip6_hdr, ip6_dst), 191 sizeof(struct in6_addr), 192 &dst_address.sin6.sin6_addr); 193 break; 194 #endif /* INET6 */ 195 default: 196 DPRINTF(("ipsec_common_input: unsupported protocol " 197 "family %u\n", af)); 198 m_freem(m); 199 IPSEC_ISTAT(sproto, espstat.esps_nopf, ahstat.ahs_nopf, 200 ipcompstat.ipcomps_nopf); 201 return EPFNOSUPPORT; 202 } 203 204 s = splsoftnet(); 205 206 /* NB: only pass dst since key_allocsa follows RFC2401 */ 207 sav = KEY_ALLOCSA(&dst_address, sproto, spi, sport, dport); 208 if (sav == NULL) { 209 DPRINTF(("ipsec_common_input: no key association found for" 210 " SA %s/%08lx/%u/%u\n", 211 ipsec_address(&dst_address), 212 (u_long) ntohl(spi), sproto, ntohs(dport))); 213 IPSEC_ISTAT(sproto, espstat.esps_notdb, ahstat.ahs_notdb, 214 ipcompstat.ipcomps_notdb); 215 splx(s); 216 m_freem(m); 217 return ENOENT; 218 } 219 220 if (sav->tdb_xform == NULL) { 221 DPRINTF(("ipsec_common_input: attempted to use uninitialized" 222 " SA %s/%08lx/%u\n", 223 ipsec_address(&dst_address), 224 (u_long) ntohl(spi), sproto)); 225 IPSEC_ISTAT(sproto, espstat.esps_noxform, ahstat.ahs_noxform, 226 ipcompstat.ipcomps_noxform); 227 KEY_FREESAV(&sav); 228 splx(s); 229 m_freem(m); 230 return ENXIO; 231 } 232 233 /* 234 * Call appropriate transform and return -- callback takes care of 235 * everything else. 236 */ 237 error = (*sav->tdb_xform->xf_input)(m, sav, skip, protoff); 238 KEY_FREESAV(&sav); 239 splx(s); 240 return error; 241 } 242 243 #ifdef INET 244 /* 245 * Common input handler for IPv4 AH, ESP, and IPCOMP. 246 */ 247 void 248 ipsec4_common_input(struct mbuf *m, ...) 249 { 250 va_list ap; 251 int off, nxt; 252 253 va_start(ap, m); 254 off = va_arg(ap, int); 255 nxt = va_arg(ap, int); 256 va_end(ap); 257 258 (void) ipsec_common_input(m, off, offsetof(struct ip, ip_p), 259 AF_INET, nxt); 260 } 261 262 /* 263 * IPsec input callback for INET protocols. 264 * This routine is called as the transform callback. 265 * Takes care of filtering and other sanity checks on 266 * the processed packet. 267 */ 268 int 269 ipsec4_common_input_cb(struct mbuf *m, struct secasvar *sav, 270 int skip, int protoff, struct m_tag *mt) 271 { 272 int prot, af, sproto; 273 struct ip *ip; 274 struct m_tag *mtag; 275 struct tdb_ident *tdbi; 276 struct secasindex *saidx; 277 int error; 278 279 IPSEC_SPLASSERT_SOFTNET("ipsec4_common_input_cb"); 280 281 IPSEC_ASSERT(m != NULL, ("ipsec4_common_input_cb: null mbuf")); 282 IPSEC_ASSERT(sav != NULL, ("ipsec4_common_input_cb: null SA")); 283 IPSEC_ASSERT(sav->sah != NULL, ("ipsec4_common_input_cb: null SAH")); 284 saidx = &sav->sah->saidx; 285 af = saidx->dst.sa.sa_family; 286 IPSEC_ASSERT(af == AF_INET, ("ipsec4_common_input_cb: unexpected af %u",af)); 287 sproto = saidx->proto; 288 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH || 289 sproto == IPPROTO_IPCOMP, 290 ("ipsec4_common_input_cb: unexpected security protocol %u", 291 sproto)); 292 293 /* Sanity check */ 294 if (m == NULL) { 295 DPRINTF(("ipsec4_common_input_cb: null mbuf")); 296 IPSEC_ISTAT(sproto, espstat.esps_badkcr, ahstat.ahs_badkcr, 297 ipcompstat.ipcomps_badkcr); 298 KEY_FREESAV(&sav); 299 return EINVAL; 300 } 301 302 if (skip != 0) { 303 /* Fix IPv4 header */ 304 if (m->m_len < skip && (m = m_pullup(m, skip)) == NULL) { 305 DPRINTF(("ipsec4_common_input_cb: processing failed " 306 "for SA %s/%08lx\n", 307 ipsec_address(&sav->sah->saidx.dst), 308 (u_long) ntohl(sav->spi))); 309 IPSEC_ISTAT(sproto, espstat.esps_hdrops, ahstat.ahs_hdrops, 310 ipcompstat.ipcomps_hdrops); 311 error = ENOBUFS; 312 goto bad; 313 } 314 315 ip = mtod(m, struct ip *); 316 ip->ip_len = htons(m->m_pkthdr.len); 317 #ifdef __FreeBSD__ 318 /* On FreeBSD, ip_off and ip_len assumed in host endian. */ 319 ip->ip_off = htons(ip->ip_off); 320 #endif 321 ip->ip_sum = 0; 322 ip->ip_sum = in_cksum(m, ip->ip_hl << 2); 323 } else { 324 ip = mtod(m, struct ip *); 325 } 326 prot = ip->ip_p; 327 328 /* IP-in-IP encapsulation */ 329 if (prot == IPPROTO_IPIP) { 330 struct ip ipn; 331 332 /* ipn will now contain the inner IPv4 header */ 333 m_copydata(m, ip->ip_hl << 2, sizeof(struct ip), &ipn); 334 335 #ifdef notyet 336 /* XXX PROXY address isn't recorded in SAH */ 337 /* 338 * Check that the inner source address is the same as 339 * the proxy address, if available. 340 */ 341 if ((saidx->proxy.sa.sa_family == AF_INET && 342 saidx->proxy.sin.sin_addr.s_addr != 343 INADDR_ANY && 344 ipn.ip_src.s_addr != 345 saidx->proxy.sin.sin_addr.s_addr) || 346 (saidx->proxy.sa.sa_family != AF_INET && 347 saidx->proxy.sa.sa_family != 0)) { 348 349 DPRINTF(("ipsec4_common_input_cb: inner " 350 "source address %s doesn't correspond to " 351 "expected proxy source %s, SA %s/%08lx\n", 352 inet_ntoa4(ipn.ip_src), 353 ipsp_address(saidx->proxy), 354 ipsp_address(saidx->dst), 355 (u_long) ntohl(sav->spi))); 356 357 IPSEC_ISTAT(sproto, espstat.esps_pdrops, 358 ahstat.ahs_pdrops, 359 ipcompstat.ipcomps_pdrops); 360 error = EACCES; 361 goto bad; 362 } 363 #endif /*XXX*/ 364 } 365 #if INET6 366 /* IPv6-in-IP encapsulation. */ 367 if (prot == IPPROTO_IPV6) { 368 struct ip6_hdr ip6n; 369 370 /* ip6n will now contain the inner IPv6 header. */ 371 m_copydata(m, ip->ip_hl << 2, sizeof(struct ip6_hdr), &ip6n); 372 373 #ifdef notyet 374 /* 375 * Check that the inner source address is the same as 376 * the proxy address, if available. 377 */ 378 if ((saidx->proxy.sa.sa_family == AF_INET6 && 379 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) && 380 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src, 381 &saidx->proxy.sin6.sin6_addr)) || 382 (saidx->proxy.sa.sa_family != AF_INET6 && 383 saidx->proxy.sa.sa_family != 0)) { 384 385 DPRINTF(("ipsec4_common_input_cb: inner " 386 "source address %s doesn't correspond to " 387 "expected proxy source %s, SA %s/%08lx\n", 388 ip6_sprintf(&ip6n.ip6_src), 389 ipsec_address(&saidx->proxy), 390 ipsec_address(&saidx->dst), 391 (u_long) ntohl(sav->spi))); 392 393 IPSEC_ISTAT(sproto, espstat.esps_pdrops, 394 ahstat.ahs_pdrops, 395 ipcompstat.ipcomps_pdrops); 396 error = EACCES; 397 goto bad; 398 } 399 #endif /*XXX*/ 400 } 401 #endif /* INET6 */ 402 403 /* 404 * Record what we've done to the packet (under what SA it was 405 * processed). If we've been passed an mtag, it means the packet 406 * was already processed by an ethernet/crypto combo card and 407 * thus has a tag attached with all the right information, but 408 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to 409 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type. 410 */ 411 if (mt == NULL && sproto != IPPROTO_IPCOMP) { 412 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE, 413 sizeof(struct tdb_ident), M_NOWAIT); 414 if (mtag == NULL) { 415 DPRINTF(("ipsec4_common_input_cb: failed to get tag\n")); 416 IPSEC_ISTAT(sproto, espstat.esps_hdrops, 417 ahstat.ahs_hdrops, ipcompstat.ipcomps_hdrops); 418 error = ENOMEM; 419 goto bad; 420 } 421 422 tdbi = (struct tdb_ident *)(mtag + 1); 423 bcopy(&saidx->dst, &tdbi->dst, saidx->dst.sa.sa_len); 424 tdbi->proto = sproto; 425 tdbi->spi = sav->spi; 426 427 m_tag_prepend(m, mtag); 428 } else { 429 if (mt != NULL) 430 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE; 431 /* XXX do we need to mark m_flags??? */ 432 } 433 434 key_sa_recordxfer(sav, m); /* record data transfer */ 435 436 /* 437 * Re-dispatch via software interrupt. 438 */ 439 if (!IF_HANDOFF(&ipintrq, m, NULL)) { 440 IPSEC_ISTAT(sproto, espstat.esps_qfull, ahstat.ahs_qfull, 441 ipcompstat.ipcomps_qfull); 442 443 DPRINTF(("ipsec4_common_input_cb: queue full; " 444 "proto %u packet dropped\n", sproto)); 445 return ENOBUFS; 446 } 447 schednetisr(NETISR_IP); 448 return 0; 449 bad: 450 m_freem(m); 451 return error; 452 } 453 #endif /* INET */ 454 455 #ifdef INET6 456 /* IPv6 AH wrapper. */ 457 int 458 ipsec6_common_input(struct mbuf **mp, int *offp, int proto) 459 { 460 int l = 0; 461 int protoff; 462 struct ip6_ext ip6e; 463 464 if (*offp < sizeof(struct ip6_hdr)) { 465 DPRINTF(("ipsec6_common_input: bad offset %u\n", *offp)); 466 return IPPROTO_DONE; 467 } else if (*offp == sizeof(struct ip6_hdr)) { 468 protoff = offsetof(struct ip6_hdr, ip6_nxt); 469 } else { 470 /* Chase down the header chain... */ 471 protoff = sizeof(struct ip6_hdr); 472 473 do { 474 protoff += l; 475 m_copydata(*mp, protoff, sizeof(ip6e), &ip6e); 476 477 if (ip6e.ip6e_nxt == IPPROTO_AH) 478 l = (ip6e.ip6e_len + 2) << 2; 479 else 480 l = (ip6e.ip6e_len + 1) << 3; 481 IPSEC_ASSERT(l > 0, ("ah6_input: l went zero or negative")); 482 } while (protoff + l < *offp); 483 484 /* Malformed packet check */ 485 if (protoff + l != *offp) { 486 DPRINTF(("ipsec6_common_input: bad packet header chain, " 487 "protoff %u, l %u, off %u\n", protoff, l, *offp)); 488 IPSEC_ISTAT(proto, espstat.esps_hdrops, 489 ahstat.ahs_hdrops, 490 ipcompstat.ipcomps_hdrops); 491 m_freem(*mp); 492 *mp = NULL; 493 return IPPROTO_DONE; 494 } 495 protoff += offsetof(struct ip6_ext, ip6e_nxt); 496 } 497 (void) ipsec_common_input(*mp, *offp, protoff, AF_INET6, proto); 498 return IPPROTO_DONE; 499 } 500 501 /* 502 * NB: ipsec_netbsd.c has a duplicate definition of esp6_ctlinput(), 503 * with slightly ore recent multicast tests. These should be merged. 504 * For now, ifdef accordingly. 505 */ 506 #ifdef __FreeBSD__ 507 void 508 esp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 509 { 510 if (sa->sa_family != AF_INET6 || 511 sa->sa_len != sizeof(struct sockaddr_in6)) 512 return; 513 if ((unsigned)cmd >= PRC_NCMDS) 514 return; 515 516 /* if the parameter is from icmp6, decode it. */ 517 if (d != NULL) { 518 struct ip6ctlparam *ip6cp = (struct ip6ctlparam *)d; 519 struct mbuf *m = ip6cp->ip6c_m; 520 int off = ip6cp->ip6c_off; 521 522 struct ip6ctlparam ip6cp1; 523 524 /* 525 * Notify the error to all possible sockets via pfctlinput2. 526 * Since the upper layer information (such as protocol type, 527 * source and destination ports) is embedded in the encrypted 528 * data and might have been cut, we can't directly call 529 * an upper layer ctlinput function. However, the pcbnotify 530 * function will consider source and destination addresses 531 * as well as the flow info value, and may be able to find 532 * some PCB that should be notified. 533 * Although pfctlinput2 will call esp6_ctlinput(), there is 534 * no possibility of an infinite loop of function calls, 535 * because we don't pass the inner IPv6 header. 536 */ 537 bzero(&ip6cp1, sizeof(ip6cp1)); 538 ip6cp1.ip6c_src = ip6cp->ip6c_src; 539 pfctlinput2(cmd, sa, &ip6cp1); 540 541 /* 542 * Then go to special cases that need ESP header information. 543 * XXX: We assume that when ip6 is non NULL, 544 * M and OFF are valid. 545 */ 546 547 if (cmd == PRC_MSGSIZE) { 548 struct secasvar *sav; 549 u_int32_t spi; 550 int valid; 551 552 /* check header length before using m_copydata */ 553 if (m->m_pkthdr.len < off + sizeof (struct esp)) 554 return; 555 m_copydata(m, off + offsetof(struct esp, esp_spi), 556 sizeof(u_int32_t), &spi); 557 /* 558 * Check to see if we have a valid SA corresponding to 559 * the address in the ICMP message payload. 560 */ 561 sav = KEY_ALLOCSA((union sockaddr_union *)sa, 562 IPPROTO_ESP, spi); 563 valid = (sav != NULL); 564 if (sav) 565 KEY_FREESAV(&sav); 566 567 /* XXX Further validation? */ 568 569 /* 570 * Depending on whether the SA is "valid" and 571 * routing table size (mtudisc_{hi,lo}wat), we will: 572 * - recalcurate the new MTU and create the 573 * corresponding routing entry, or 574 * - ignore the MTU change notification. 575 */ 576 icmp6_mtudisc_update(ip6cp, valid); 577 } 578 } else { 579 /* we normally notify any pcb here */ 580 } 581 } 582 #endif /* __FreeBSD__ */ 583 584 extern const struct ip6protosw inet6sw[]; 585 extern u_char ip6_protox[]; 586 587 /* 588 * IPsec input callback, called by the transform callback. Takes care of 589 * filtering and other sanity checks on the processed packet. 590 */ 591 int 592 ipsec6_common_input_cb(struct mbuf *m, struct secasvar *sav, int skip, int protoff, 593 struct m_tag *mt) 594 { 595 int prot, af, sproto; 596 struct ip6_hdr *ip6; 597 struct m_tag *mtag; 598 struct tdb_ident *tdbi; 599 struct secasindex *saidx; 600 int nxt; 601 u_int8_t nxt8; 602 int error, nest; 603 604 IPSEC_ASSERT(m != NULL, ("ipsec6_common_input_cb: null mbuf")); 605 IPSEC_ASSERT(sav != NULL, ("ipsec6_common_input_cb: null SA")); 606 IPSEC_ASSERT(sav->sah != NULL, ("ipsec6_common_input_cb: null SAH")); 607 saidx = &sav->sah->saidx; 608 af = saidx->dst.sa.sa_family; 609 IPSEC_ASSERT(af == AF_INET6, 610 ("ipsec6_common_input_cb: unexpected af %u", af)); 611 sproto = saidx->proto; 612 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH || 613 sproto == IPPROTO_IPCOMP, 614 ("ipsec6_common_input_cb: unexpected security protocol %u", 615 sproto)); 616 617 /* Sanity check */ 618 if (m == NULL) { 619 DPRINTF(("ipsec6_common_input_cb: null mbuf")); 620 IPSEC_ISTAT(sproto, espstat.esps_badkcr, ahstat.ahs_badkcr, 621 ipcompstat.ipcomps_badkcr); 622 error = EINVAL; 623 goto bad; 624 } 625 626 /* Fix IPv6 header */ 627 if (m->m_len < sizeof(struct ip6_hdr) && 628 (m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 629 630 DPRINTF(("ipsec6_common_input_cb: processing failed " 631 "for SA %s/%08lx\n", ipsec_address(&sav->sah->saidx.dst), 632 (u_long) ntohl(sav->spi))); 633 634 IPSEC_ISTAT(sproto, espstat.esps_hdrops, ahstat.ahs_hdrops, 635 ipcompstat.ipcomps_hdrops); 636 error = EACCES; 637 goto bad; 638 } 639 640 ip6 = mtod(m, struct ip6_hdr *); 641 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 642 643 /* Save protocol */ 644 m_copydata(m, protoff, 1, (unsigned char *) &prot); 645 646 #ifdef INET 647 /* IP-in-IP encapsulation */ 648 if (prot == IPPROTO_IPIP) { 649 struct ip ipn; 650 651 /* ipn will now contain the inner IPv4 header */ 652 m_copydata(m, skip, sizeof(struct ip), &ipn); 653 654 #ifdef notyet 655 /* 656 * Check that the inner source address is the same as 657 * the proxy address, if available. 658 */ 659 if ((saidx->proxy.sa.sa_family == AF_INET && 660 saidx->proxy.sin.sin_addr.s_addr != INADDR_ANY && 661 ipn.ip_src.s_addr != saidx->proxy.sin.sin_addr.s_addr) || 662 (saidx->proxy.sa.sa_family != AF_INET && 663 saidx->proxy.sa.sa_family != 0)) { 664 665 DPRINTF(("ipsec6_common_input_cb: inner " 666 "source address %s doesn't correspond to " 667 "expected proxy source %s, SA %s/%08lx\n", 668 inet_ntoa4(ipn.ip_src), 669 ipsec_address(&saidx->proxy), 670 ipsec_address(&saidx->dst), 671 (u_long) ntohl(sav->spi))); 672 673 IPSEC_ISTAT(sproto, espstat.esps_pdrops, 674 ahstat.ahs_pdrops, ipcompstat.ipcomps_pdrops); 675 error = EACCES; 676 goto bad; 677 } 678 #endif /*XXX*/ 679 } 680 #endif /* INET */ 681 682 /* IPv6-in-IP encapsulation */ 683 if (prot == IPPROTO_IPV6) { 684 struct ip6_hdr ip6n; 685 686 /* ip6n will now contain the inner IPv6 header. */ 687 m_copydata(m, skip, sizeof(struct ip6_hdr), &ip6n); 688 689 #ifdef notyet 690 /* 691 * Check that the inner source address is the same as 692 * the proxy address, if available. 693 */ 694 if ((saidx->proxy.sa.sa_family == AF_INET6 && 695 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) && 696 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src, 697 &saidx->proxy.sin6.sin6_addr)) || 698 (saidx->proxy.sa.sa_family != AF_INET6 && 699 saidx->proxy.sa.sa_family != 0)) { 700 701 DPRINTF(("ipsec6_common_input_cb: inner " 702 "source address %s doesn't correspond to " 703 "expected proxy source %s, SA %s/%08lx\n", 704 ip6_sprintf(&ip6n.ip6_src), 705 ipsec_address(&saidx->proxy), 706 ipsec_address(&saidx->dst), 707 (u_long) ntohl(sav->spi))); 708 709 IPSEC_ISTAT(sproto, espstat.esps_pdrops, 710 ahstat.ahs_pdrops, ipcompstat.ipcomps_pdrops); 711 error = EACCES; 712 goto bad; 713 } 714 #endif /*XXX*/ 715 } 716 717 /* 718 * Record what we've done to the packet (under what SA it was 719 * processed). If we've been passed an mtag, it means the packet 720 * was already processed by an ethernet/crypto combo card and 721 * thus has a tag attached with all the right information, but 722 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to 723 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type. 724 */ 725 if (mt == NULL && sproto != IPPROTO_IPCOMP) { 726 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE, 727 sizeof(struct tdb_ident), M_NOWAIT); 728 if (mtag == NULL) { 729 DPRINTF(("ipsec_common_input_cb: failed to " 730 "get tag\n")); 731 IPSEC_ISTAT(sproto, espstat.esps_hdrops, 732 ahstat.ahs_hdrops, ipcompstat.ipcomps_hdrops); 733 error = ENOMEM; 734 goto bad; 735 } 736 737 tdbi = (struct tdb_ident *)(mtag + 1); 738 bcopy(&saidx->dst, &tdbi->dst, sizeof(union sockaddr_union)); 739 tdbi->proto = sproto; 740 tdbi->spi = sav->spi; 741 742 m_tag_prepend(m, mtag); 743 } else { 744 if (mt != NULL) 745 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE; 746 /* XXX do we need to mark m_flags??? */ 747 } 748 749 key_sa_recordxfer(sav, m); 750 751 /* Retrieve new protocol */ 752 m_copydata(m, protoff, sizeof(u_int8_t), &nxt8); 753 754 /* 755 * See the end of ip6_input for this logic. 756 * IPPROTO_IPV[46] case will be processed just like other ones 757 */ 758 nest = 0; 759 nxt = nxt8; 760 while (nxt != IPPROTO_DONE) { 761 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 762 ip6stat.ip6s_toomanyhdr++; 763 error = EINVAL; 764 goto bad; 765 } 766 767 /* 768 * Protection against faulty packet - there should be 769 * more sanity checks in header chain processing. 770 */ 771 if (m->m_pkthdr.len < skip) { 772 ip6stat.ip6s_tooshort++; 773 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 774 error = EINVAL; 775 goto bad; 776 } 777 /* 778 * Enforce IPsec policy checking if we are seeing last header. 779 * note that we do not visit this with protocols with pcb layer 780 * code - like udp/tcp/raw ip. 781 */ 782 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 783 ipsec6_in_reject(m, NULL)) { 784 error = EINVAL; 785 goto bad; 786 } 787 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &skip, nxt); 788 } 789 return 0; 790 bad: 791 if (m) 792 m_freem(m); 793 return error; 794 } 795 #endif /* INET6 */ 796