1 /* $NetBSD: ipsec_input.c,v 1.28 2011/07/17 20:54:54 joerg 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 1.28 2011/07/17 20:54:54 joerg 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 #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 if (skip != 0) { 320 /* Fix IPv4 header */ 321 if (m->m_len < skip && (m = m_pullup(m, skip)) == NULL) { 322 DPRINTF(("ipsec4_common_input_cb: processing failed " 323 "for SA %s/%08lx\n", 324 ipsec_address(&sav->sah->saidx.dst), 325 (u_long) ntohl(sav->spi))); 326 IPSEC_ISTAT(sproto, ESP_STAT_HDROPS, AH_STAT_HDROPS, 327 IPCOMP_STAT_HDROPS); 328 error = ENOBUFS; 329 goto bad; 330 } 331 332 ip = mtod(m, struct ip *); 333 ip->ip_len = htons(m->m_pkthdr.len); 334 #ifdef __FreeBSD__ 335 /* On FreeBSD, ip_off and ip_len assumed in host endian. */ 336 ip->ip_off = htons(ip->ip_off); 337 #endif 338 ip->ip_sum = 0; 339 ip->ip_sum = in_cksum(m, ip->ip_hl << 2); 340 } else { 341 ip = mtod(m, struct ip *); 342 } 343 prot = ip->ip_p; 344 345 /* IP-in-IP encapsulation */ 346 if (prot == IPPROTO_IPIP) { 347 struct ip ipn; 348 349 /* ipn will now contain the inner IPv4 header */ 350 m_copydata(m, ip->ip_hl << 2, sizeof(struct ip), &ipn); 351 352 #ifdef notyet 353 /* XXX PROXY address isn't recorded in SAH */ 354 /* 355 * Check that the inner source address is the same as 356 * the proxy address, if available. 357 */ 358 if ((saidx->proxy.sa.sa_family == AF_INET && 359 saidx->proxy.sin.sin_addr.s_addr != 360 INADDR_ANY && 361 ipn.ip_src.s_addr != 362 saidx->proxy.sin.sin_addr.s_addr) || 363 (saidx->proxy.sa.sa_family != AF_INET && 364 saidx->proxy.sa.sa_family != 0)) { 365 366 DPRINTF(("ipsec4_common_input_cb: inner " 367 "source address %s doesn't correspond to " 368 "expected proxy source %s, SA %s/%08lx\n", 369 inet_ntoa4(ipn.ip_src), 370 ipsp_address(saidx->proxy), 371 ipsp_address(saidx->dst), 372 (u_long) ntohl(sav->spi))); 373 374 IPSEC_ISTAT(sproto, ESP_STAT_PDROPS, 375 AH_STAT_PDROPS, 376 IPCOMP_STAT_PDROPS); 377 error = EACCES; 378 goto bad; 379 } 380 #endif /*XXX*/ 381 } 382 #if INET6 383 /* IPv6-in-IP encapsulation. */ 384 if (prot == IPPROTO_IPV6) { 385 struct ip6_hdr ip6n; 386 387 /* ip6n will now contain the inner IPv6 header. */ 388 m_copydata(m, ip->ip_hl << 2, sizeof(struct ip6_hdr), &ip6n); 389 390 #ifdef notyet 391 /* 392 * Check that the inner source address is the same as 393 * the proxy address, if available. 394 */ 395 if ((saidx->proxy.sa.sa_family == AF_INET6 && 396 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) && 397 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src, 398 &saidx->proxy.sin6.sin6_addr)) || 399 (saidx->proxy.sa.sa_family != AF_INET6 && 400 saidx->proxy.sa.sa_family != 0)) { 401 402 DPRINTF(("ipsec4_common_input_cb: inner " 403 "source address %s doesn't correspond to " 404 "expected proxy source %s, SA %s/%08lx\n", 405 ip6_sprintf(&ip6n.ip6_src), 406 ipsec_address(&saidx->proxy), 407 ipsec_address(&saidx->dst), 408 (u_long) ntohl(sav->spi))); 409 410 IPSEC_ISTAT(sproto, ESP_STAT_PDROPS, 411 AH_STAT_PDROPS, 412 IPCOMP_STAT_PDROPS); 413 error = EACCES; 414 goto bad; 415 } 416 #endif /*XXX*/ 417 } 418 #endif /* INET6 */ 419 420 /* 421 * Record what we've done to the packet (under what SA it was 422 * processed). If we've been passed an mtag, it means the packet 423 * was already processed by an ethernet/crypto combo card and 424 * thus has a tag attached with all the right information, but 425 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to 426 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type. 427 */ 428 if (mt == NULL && sproto != IPPROTO_IPCOMP) { 429 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE, 430 sizeof(struct tdb_ident), M_NOWAIT); 431 if (mtag == NULL) { 432 DPRINTF(("ipsec4_common_input_cb: failed to get tag\n")); 433 IPSEC_ISTAT(sproto, ESP_STAT_HDROPS, 434 AH_STAT_HDROPS, IPCOMP_STAT_HDROPS); 435 error = ENOMEM; 436 goto bad; 437 } 438 439 tdbi = (struct tdb_ident *)(mtag + 1); 440 memcpy(&tdbi->dst, &saidx->dst, saidx->dst.sa.sa_len); 441 tdbi->proto = sproto; 442 tdbi->spi = sav->spi; 443 444 m_tag_prepend(m, mtag); 445 } else { 446 if (mt != NULL) 447 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE; 448 /* XXX do we need to mark m_flags??? */ 449 } 450 451 key_sa_recordxfer(sav, m); /* record data transfer */ 452 453 /* 454 * Re-dispatch via software interrupt. 455 */ 456 if (!IF_HANDOFF(&ipintrq, m, NULL)) { 457 IPSEC_ISTAT(sproto, ESP_STAT_QFULL, AH_STAT_QFULL, 458 IPCOMP_STAT_QFULL); 459 460 DPRINTF(("ipsec4_common_input_cb: queue full; " 461 "proto %u packet dropped\n", sproto)); 462 return ENOBUFS; 463 } 464 schednetisr(NETISR_IP); 465 return 0; 466 bad: 467 m_freem(m); 468 return error; 469 } 470 #endif /* INET */ 471 472 #ifdef INET6 473 /* IPv6 AH wrapper. */ 474 int 475 ipsec6_common_input(struct mbuf **mp, int *offp, int proto) 476 { 477 int l = 0; 478 int protoff, nxt; 479 struct ip6_ext ip6e; 480 481 if (*offp < sizeof(struct ip6_hdr)) { 482 DPRINTF(("ipsec6_common_input: bad offset %u\n", *offp)); 483 IPSEC_ISTAT(proto, ESP_STAT_HDROPS, AH_STAT_HDROPS, 484 IPCOMP_STAT_HDROPS); 485 m_freem(*mp); 486 return IPPROTO_DONE; 487 } else if (*offp == sizeof(struct ip6_hdr)) { 488 protoff = offsetof(struct ip6_hdr, ip6_nxt); 489 } else { 490 /* Chase down the header chain... */ 491 protoff = sizeof(struct ip6_hdr); 492 nxt = (mtod(*mp, struct ip6_hdr *))->ip6_nxt; 493 494 do { 495 protoff += l; 496 m_copydata(*mp, protoff, sizeof(ip6e), &ip6e); 497 498 if (nxt == IPPROTO_AH) 499 l = (ip6e.ip6e_len + 2) << 2; 500 else 501 l = (ip6e.ip6e_len + 1) << 3; 502 IPSEC_ASSERT(l > 0, 503 ("ipsec6_common_input: l went zero or negative")); 504 505 nxt = ip6e.ip6e_nxt; 506 } while (protoff + l < *offp); 507 508 /* Malformed packet check */ 509 if (protoff + l != *offp) { 510 DPRINTF(("ipsec6_common_input: bad packet header chain, " 511 "protoff %u, l %u, off %u\n", protoff, l, *offp)); 512 IPSEC_ISTAT(proto, ESP_STAT_HDROPS, 513 AH_STAT_HDROPS, 514 IPCOMP_STAT_HDROPS); 515 m_freem(*mp); 516 *mp = NULL; 517 return IPPROTO_DONE; 518 } 519 protoff += offsetof(struct ip6_ext, ip6e_nxt); 520 } 521 (void) ipsec_common_input(*mp, *offp, protoff, AF_INET6, proto); 522 return IPPROTO_DONE; 523 } 524 525 /* 526 * NB: ipsec_netbsd.c has a duplicate definition of esp6_ctlinput(), 527 * with slightly ore recent multicast tests. These should be merged. 528 * For now, ifdef accordingly. 529 */ 530 #ifdef __FreeBSD__ 531 void 532 esp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 533 { 534 if (sa->sa_family != AF_INET6 || 535 sa->sa_len != sizeof(struct sockaddr_in6)) 536 return; 537 if ((unsigned)cmd >= PRC_NCMDS) 538 return; 539 540 /* if the parameter is from icmp6, decode it. */ 541 if (d != NULL) { 542 struct ip6ctlparam *ip6cp = (struct ip6ctlparam *)d; 543 struct mbuf *m = ip6cp->ip6c_m; 544 int off = ip6cp->ip6c_off; 545 546 struct ip6ctlparam ip6cp1; 547 548 /* 549 * Notify the error to all possible sockets via pfctlinput2. 550 * Since the upper layer information (such as protocol type, 551 * source and destination ports) is embedded in the encrypted 552 * data and might have been cut, we can't directly call 553 * an upper layer ctlinput function. However, the pcbnotify 554 * function will consider source and destination addresses 555 * as well as the flow info value, and may be able to find 556 * some PCB that should be notified. 557 * Although pfctlinput2 will call esp6_ctlinput(), there is 558 * no possibility of an infinite loop of function calls, 559 * because we don't pass the inner IPv6 header. 560 */ 561 memset(&ip6cp1, 0, sizeof(ip6cp1)); 562 ip6cp1.ip6c_src = ip6cp->ip6c_src; 563 pfctlinput2(cmd, sa, &ip6cp1); 564 565 /* 566 * Then go to special cases that need ESP header information. 567 * XXX: We assume that when ip6 is non NULL, 568 * M and OFF are valid. 569 */ 570 571 if (cmd == PRC_MSGSIZE) { 572 struct secasvar *sav; 573 u_int32_t spi; 574 int valid; 575 576 /* check header length before using m_copydata */ 577 if (m->m_pkthdr.len < off + sizeof (struct esp)) 578 return; 579 m_copydata(m, off + offsetof(struct esp, esp_spi), 580 sizeof(u_int32_t), &spi); 581 /* 582 * Check to see if we have a valid SA corresponding to 583 * the address in the ICMP message payload. 584 */ 585 sav = KEY_ALLOCSA((union sockaddr_union *)sa, 586 IPPROTO_ESP, spi); 587 valid = (sav != NULL); 588 if (sav) 589 KEY_FREESAV(&sav); 590 591 /* XXX Further validation? */ 592 593 /* 594 * Depending on whether the SA is "valid" and 595 * routing table size (mtudisc_{hi,lo}wat), we will: 596 * - recalcurate the new MTU and create the 597 * corresponding routing entry, or 598 * - ignore the MTU change notification. 599 */ 600 icmp6_mtudisc_update(ip6cp, valid); 601 } 602 } else { 603 /* we normally notify any pcb here */ 604 } 605 } 606 #endif /* __FreeBSD__ */ 607 608 extern const struct ip6protosw inet6sw[]; 609 extern u_char ip6_protox[]; 610 611 /* 612 * IPsec input callback, called by the transform callback. Takes care of 613 * filtering and other sanity checks on the processed packet. 614 */ 615 int 616 ipsec6_common_input_cb(struct mbuf *m, struct secasvar *sav, int skip, int protoff, 617 struct m_tag *mt) 618 { 619 int af, sproto; 620 struct ip6_hdr *ip6; 621 struct m_tag *mtag; 622 struct tdb_ident *tdbi; 623 struct secasindex *saidx; 624 int nxt; 625 u_int8_t prot, nxt8; 626 int error, nest; 627 628 IPSEC_ASSERT(m != NULL, ("ipsec6_common_input_cb: null mbuf")); 629 IPSEC_ASSERT(sav != NULL, ("ipsec6_common_input_cb: null SA")); 630 IPSEC_ASSERT(sav->sah != NULL, ("ipsec6_common_input_cb: null SAH")); 631 saidx = &sav->sah->saidx; 632 af = saidx->dst.sa.sa_family; 633 IPSEC_ASSERT(af == AF_INET6, 634 ("ipsec6_common_input_cb: unexpected af %u", af)); 635 sproto = saidx->proto; 636 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH || 637 sproto == IPPROTO_IPCOMP, 638 ("ipsec6_common_input_cb: unexpected security protocol %u", 639 sproto)); 640 641 /* Sanity check */ 642 if (m == NULL) { 643 DPRINTF(("ipsec6_common_input_cb: null mbuf")); 644 IPSEC_ISTAT(sproto, ESP_STAT_BADKCR, AH_STAT_BADKCR, 645 IPCOMP_STAT_BADKCR); 646 error = EINVAL; 647 goto bad; 648 } 649 650 /* Fix IPv6 header */ 651 if (m->m_len < sizeof(struct ip6_hdr) && 652 (m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 653 654 DPRINTF(("ipsec6_common_input_cb: processing failed " 655 "for SA %s/%08lx\n", ipsec_address(&sav->sah->saidx.dst), 656 (u_long) ntohl(sav->spi))); 657 658 IPSEC_ISTAT(sproto, ESP_STAT_HDROPS, AH_STAT_HDROPS, 659 IPCOMP_STAT_HDROPS); 660 error = EACCES; 661 goto bad; 662 } 663 664 ip6 = mtod(m, struct ip6_hdr *); 665 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 666 667 /* Save protocol */ 668 m_copydata(m, protoff, 1, &prot); 669 670 #ifdef INET 671 /* IP-in-IP encapsulation */ 672 if (prot == IPPROTO_IPIP) { 673 struct ip ipn; 674 675 /* ipn will now contain the inner IPv4 header */ 676 m_copydata(m, skip, sizeof(struct ip), &ipn); 677 678 #ifdef notyet 679 /* 680 * Check that the inner source address is the same as 681 * the proxy address, if available. 682 */ 683 if ((saidx->proxy.sa.sa_family == AF_INET && 684 saidx->proxy.sin.sin_addr.s_addr != INADDR_ANY && 685 ipn.ip_src.s_addr != saidx->proxy.sin.sin_addr.s_addr) || 686 (saidx->proxy.sa.sa_family != AF_INET && 687 saidx->proxy.sa.sa_family != 0)) { 688 689 DPRINTF(("ipsec6_common_input_cb: inner " 690 "source address %s doesn't correspond to " 691 "expected proxy source %s, SA %s/%08lx\n", 692 inet_ntoa4(ipn.ip_src), 693 ipsec_address(&saidx->proxy), 694 ipsec_address(&saidx->dst), 695 (u_long) ntohl(sav->spi))); 696 697 IPSEC_ISTAT(sproto, ESP_STAT_PDROPS, 698 AH_STAT_PDROPS, IPCOMP_STAT_PDROPS); 699 error = EACCES; 700 goto bad; 701 } 702 #endif /*XXX*/ 703 } 704 #endif /* INET */ 705 706 /* IPv6-in-IP encapsulation */ 707 if (prot == IPPROTO_IPV6) { 708 struct ip6_hdr ip6n; 709 710 /* ip6n will now contain the inner IPv6 header. */ 711 m_copydata(m, skip, sizeof(struct ip6_hdr), &ip6n); 712 713 #ifdef notyet 714 /* 715 * Check that the inner source address is the same as 716 * the proxy address, if available. 717 */ 718 if ((saidx->proxy.sa.sa_family == AF_INET6 && 719 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) && 720 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src, 721 &saidx->proxy.sin6.sin6_addr)) || 722 (saidx->proxy.sa.sa_family != AF_INET6 && 723 saidx->proxy.sa.sa_family != 0)) { 724 725 DPRINTF(("ipsec6_common_input_cb: inner " 726 "source address %s doesn't correspond to " 727 "expected proxy source %s, SA %s/%08lx\n", 728 ip6_sprintf(&ip6n.ip6_src), 729 ipsec_address(&saidx->proxy), 730 ipsec_address(&saidx->dst), 731 (u_long) ntohl(sav->spi))); 732 733 IPSEC_ISTAT(sproto, ESP_STAT_PDROPS, 734 AH_STAT_PDROPS, IPCOMP_STAT_PDROPS); 735 error = EACCES; 736 goto bad; 737 } 738 #endif /*XXX*/ 739 } 740 741 /* 742 * Record what we've done to the packet (under what SA it was 743 * processed). If we've been passed an mtag, it means the packet 744 * was already processed by an ethernet/crypto combo card and 745 * thus has a tag attached with all the right information, but 746 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to 747 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type. 748 */ 749 if (mt == NULL && sproto != IPPROTO_IPCOMP) { 750 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE, 751 sizeof(struct tdb_ident), M_NOWAIT); 752 if (mtag == NULL) { 753 DPRINTF(("ipsec_common_input_cb: failed to " 754 "get tag\n")); 755 IPSEC_ISTAT(sproto, ESP_STAT_HDROPS, 756 AH_STAT_HDROPS, IPCOMP_STAT_HDROPS); 757 error = ENOMEM; 758 goto bad; 759 } 760 761 tdbi = (struct tdb_ident *)(mtag + 1); 762 memcpy(&tdbi->dst, &saidx->dst, sizeof(union sockaddr_union)); 763 tdbi->proto = sproto; 764 tdbi->spi = sav->spi; 765 766 m_tag_prepend(m, mtag); 767 } else { 768 if (mt != NULL) 769 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE; 770 /* XXX do we need to mark m_flags??? */ 771 } 772 773 key_sa_recordxfer(sav, m); 774 775 /* Retrieve new protocol */ 776 m_copydata(m, protoff, sizeof(u_int8_t), &nxt8); 777 778 /* 779 * See the end of ip6_input for this logic. 780 * IPPROTO_IPV[46] case will be processed just like other ones 781 */ 782 nest = 0; 783 nxt = nxt8; 784 while (nxt != IPPROTO_DONE) { 785 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 786 IP6_STATINC(IP6_STAT_TOOMANYHDR); 787 error = EINVAL; 788 goto bad; 789 } 790 791 /* 792 * Protection against faulty packet - there should be 793 * more sanity checks in header chain processing. 794 */ 795 if (m->m_pkthdr.len < skip) { 796 IP6_STATINC(IP6_STAT_TOOSHORT); 797 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 798 error = EINVAL; 799 goto bad; 800 } 801 /* 802 * Enforce IPsec policy checking if we are seeing last header. 803 * note that we do not visit this with protocols with pcb layer 804 * code - like udp/tcp/raw ip. 805 */ 806 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 807 ipsec6_in_reject(m, NULL)) { 808 error = EINVAL; 809 goto bad; 810 } 811 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &skip, nxt); 812 } 813 return 0; 814 bad: 815 if (m) 816 m_freem(m); 817 return error; 818 } 819 #endif /* INET6 */ 820