1 /* $NetBSD: ipsec_input.c,v 1.27 2011/02/21 22:54:45 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 1.27 2011/02/21 22:54:45 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 #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 <machine/stdarg.h> 104 105 #include <net/net_osdep.h> 106 107 #define IPSEC_ISTAT(p, x, y, z) \ 108 do { \ 109 switch (p) { \ 110 case IPPROTO_ESP: \ 111 ESP_STATINC(x); \ 112 break; \ 113 case IPPROTO_AH: \ 114 AH_STATINC(y); \ 115 break; \ 116 default: \ 117 IPCOMP_STATINC(z); \ 118 break; \ 119 } \ 120 } while (/*CONSTCOND*/0) 121 122 /* 123 * ipsec_common_input gets called when an IPsec-protected packet 124 * is received by IPv4 or IPv6. It's job is to find the right SA 125 # and call the appropriate transform. The transform callback 126 * takes care of further processing (like ingress filtering). 127 */ 128 static int 129 ipsec_common_input(struct mbuf *m, int skip, int protoff, int af, int sproto) 130 { 131 union sockaddr_union dst_address; 132 struct secasvar *sav; 133 u_int32_t spi; 134 u_int16_t sport = 0; 135 u_int16_t dport = 0; 136 int s, error; 137 #ifdef IPSEC_NAT_T 138 struct m_tag * tag = NULL; 139 #endif 140 141 IPSEC_ISTAT(sproto, ESP_STAT_INPUT, AH_STAT_INPUT, 142 IPCOMP_STAT_INPUT); 143 144 IPSEC_ASSERT(m != NULL, ("ipsec_common_input: null packet")); 145 146 if ((sproto == IPPROTO_ESP && !esp_enable) || 147 (sproto == IPPROTO_AH && !ah_enable) || 148 (sproto == IPPROTO_IPCOMP && !ipcomp_enable)) { 149 m_freem(m); 150 IPSEC_ISTAT(sproto, ESP_STAT_PDROPS, AH_STAT_PDROPS, 151 IPCOMP_STAT_PDROPS); 152 return EOPNOTSUPP; 153 } 154 155 if (m->m_pkthdr.len - skip < 2 * sizeof (u_int32_t)) { 156 m_freem(m); 157 IPSEC_ISTAT(sproto, ESP_STAT_HDROPS, AH_STAT_HDROPS, 158 IPCOMP_STAT_HDROPS); 159 DPRINTF(("ipsec_common_input: packet too small\n")); 160 return EINVAL; 161 } 162 163 /* Retrieve the SPI from the relevant IPsec header */ 164 if (sproto == IPPROTO_ESP) 165 m_copydata(m, skip, sizeof(u_int32_t), &spi); 166 else if (sproto == IPPROTO_AH) 167 m_copydata(m, skip + sizeof(u_int32_t), sizeof(u_int32_t), &spi); 168 else if (sproto == IPPROTO_IPCOMP) { 169 u_int16_t cpi; 170 m_copydata(m, skip + sizeof(u_int16_t), sizeof(u_int16_t), &cpi); 171 spi = ntohl(htons(cpi)); 172 } else { 173 panic("ipsec_common_input called with bad protocol number :" 174 "%d\n", sproto); 175 } 176 177 178 #ifdef IPSEC_NAT_T 179 /* find the source port for NAT-T */ 180 if ((tag = m_tag_find(m, PACKET_TAG_IPSEC_NAT_T_PORTS, NULL))) { 181 sport = ((u_int16_t *)(tag + 1))[0]; 182 dport = ((u_int16_t *)(tag + 1))[1]; 183 } 184 #endif 185 186 /* 187 * Find the SA and (indirectly) call the appropriate 188 * kernel crypto routine. The resulting mbuf chain is a valid 189 * IP packet ready to go through input processing. 190 */ 191 memset(&dst_address, 0, sizeof (dst_address)); 192 dst_address.sa.sa_family = af; 193 switch (af) { 194 #ifdef INET 195 case AF_INET: 196 dst_address.sin.sin_len = sizeof(struct sockaddr_in); 197 m_copydata(m, offsetof(struct ip, ip_dst), 198 sizeof(struct in_addr), 199 &dst_address.sin.sin_addr); 200 break; 201 #endif /* INET */ 202 #ifdef INET6 203 case AF_INET6: 204 dst_address.sin6.sin6_len = sizeof(struct sockaddr_in6); 205 m_copydata(m, offsetof(struct ip6_hdr, ip6_dst), 206 sizeof(struct in6_addr), 207 &dst_address.sin6.sin6_addr); 208 if (sa6_recoverscope(&dst_address.sin6)) { 209 m_freem(m); 210 return EINVAL; 211 } 212 break; 213 #endif /* INET6 */ 214 default: 215 DPRINTF(("ipsec_common_input: unsupported protocol " 216 "family %u\n", af)); 217 m_freem(m); 218 IPSEC_ISTAT(sproto, ESP_STAT_NOPF, AH_STAT_NOPF, 219 IPCOMP_STAT_NOPF); 220 return EPFNOSUPPORT; 221 } 222 223 s = splsoftnet(); 224 225 /* NB: only pass dst since key_allocsa follows RFC2401 */ 226 sav = KEY_ALLOCSA(&dst_address, sproto, spi, sport, dport); 227 if (sav == NULL) { 228 DPRINTF(("ipsec_common_input: no key association found for" 229 " SA %s/%08lx/%u/%u\n", 230 ipsec_address(&dst_address), 231 (u_long) ntohl(spi), sproto, ntohs(dport))); 232 IPSEC_ISTAT(sproto, ESP_STAT_NOTDB, AH_STAT_NOTDB, 233 IPCOMP_STAT_NOTDB); 234 splx(s); 235 m_freem(m); 236 return ENOENT; 237 } 238 239 if (sav->tdb_xform == NULL) { 240 DPRINTF(("ipsec_common_input: attempted to use uninitialized" 241 " SA %s/%08lx/%u\n", 242 ipsec_address(&dst_address), 243 (u_long) ntohl(spi), sproto)); 244 IPSEC_ISTAT(sproto, ESP_STAT_NOXFORM, AH_STAT_NOXFORM, 245 IPCOMP_STAT_NOXFORM); 246 KEY_FREESAV(&sav); 247 splx(s); 248 m_freem(m); 249 return ENXIO; 250 } 251 252 /* 253 * Call appropriate transform and return -- callback takes care of 254 * everything else. 255 */ 256 error = (*sav->tdb_xform->xf_input)(m, sav, skip, protoff); 257 KEY_FREESAV(&sav); 258 splx(s); 259 return error; 260 } 261 262 #ifdef INET 263 /* 264 * Common input handler for IPv4 AH, ESP, and IPCOMP. 265 */ 266 void 267 ipsec4_common_input(struct mbuf *m, ...) 268 { 269 va_list ap; 270 int off, nxt; 271 272 va_start(ap, m); 273 off = va_arg(ap, int); 274 nxt = va_arg(ap, int); 275 va_end(ap); 276 277 (void) ipsec_common_input(m, off, offsetof(struct ip, ip_p), 278 AF_INET, nxt); 279 } 280 281 /* 282 * IPsec input callback for INET protocols. 283 * This routine is called as the transform callback. 284 * Takes care of filtering and other sanity checks on 285 * the processed packet. 286 */ 287 int 288 ipsec4_common_input_cb(struct mbuf *m, struct secasvar *sav, 289 int skip, int protoff, struct m_tag *mt) 290 { 291 int prot, af, sproto; 292 struct ip *ip; 293 struct m_tag *mtag; 294 struct tdb_ident *tdbi; 295 struct secasindex *saidx; 296 int error; 297 298 IPSEC_SPLASSERT_SOFTNET("ipsec4_common_input_cb"); 299 300 IPSEC_ASSERT(m != NULL, ("ipsec4_common_input_cb: null mbuf")); 301 IPSEC_ASSERT(sav != NULL, ("ipsec4_common_input_cb: null SA")); 302 IPSEC_ASSERT(sav->sah != NULL, ("ipsec4_common_input_cb: null SAH")); 303 saidx = &sav->sah->saidx; 304 af = saidx->dst.sa.sa_family; 305 IPSEC_ASSERT(af == AF_INET, ("ipsec4_common_input_cb: unexpected af %u",af)); 306 sproto = saidx->proto; 307 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH || 308 sproto == IPPROTO_IPCOMP, 309 ("ipsec4_common_input_cb: unexpected security protocol %u", 310 sproto)); 311 312 /* Sanity check */ 313 if (m == NULL) { 314 DPRINTF(("ipsec4_common_input_cb: null mbuf")); 315 IPSEC_ISTAT(sproto, ESP_STAT_BADKCR, AH_STAT_BADKCR, 316 IPCOMP_STAT_BADKCR); 317 KEY_FREESAV(&sav); 318 return EINVAL; 319 } 320 321 if (skip != 0) { 322 /* Fix IPv4 header */ 323 if (m->m_len < skip && (m = m_pullup(m, skip)) == NULL) { 324 DPRINTF(("ipsec4_common_input_cb: processing failed " 325 "for SA %s/%08lx\n", 326 ipsec_address(&sav->sah->saidx.dst), 327 (u_long) ntohl(sav->spi))); 328 IPSEC_ISTAT(sproto, ESP_STAT_HDROPS, AH_STAT_HDROPS, 329 IPCOMP_STAT_HDROPS); 330 error = ENOBUFS; 331 goto bad; 332 } 333 334 ip = mtod(m, struct ip *); 335 ip->ip_len = htons(m->m_pkthdr.len); 336 #ifdef __FreeBSD__ 337 /* On FreeBSD, ip_off and ip_len assumed in host endian. */ 338 ip->ip_off = htons(ip->ip_off); 339 #endif 340 ip->ip_sum = 0; 341 ip->ip_sum = in_cksum(m, ip->ip_hl << 2); 342 } else { 343 ip = mtod(m, struct ip *); 344 } 345 prot = ip->ip_p; 346 347 /* IP-in-IP encapsulation */ 348 if (prot == IPPROTO_IPIP) { 349 struct ip ipn; 350 351 /* ipn will now contain the inner IPv4 header */ 352 m_copydata(m, ip->ip_hl << 2, sizeof(struct ip), &ipn); 353 354 #ifdef notyet 355 /* XXX PROXY address isn't recorded in SAH */ 356 /* 357 * Check that the inner source address is the same as 358 * the proxy address, if available. 359 */ 360 if ((saidx->proxy.sa.sa_family == AF_INET && 361 saidx->proxy.sin.sin_addr.s_addr != 362 INADDR_ANY && 363 ipn.ip_src.s_addr != 364 saidx->proxy.sin.sin_addr.s_addr) || 365 (saidx->proxy.sa.sa_family != AF_INET && 366 saidx->proxy.sa.sa_family != 0)) { 367 368 DPRINTF(("ipsec4_common_input_cb: inner " 369 "source address %s doesn't correspond to " 370 "expected proxy source %s, SA %s/%08lx\n", 371 inet_ntoa4(ipn.ip_src), 372 ipsp_address(saidx->proxy), 373 ipsp_address(saidx->dst), 374 (u_long) ntohl(sav->spi))); 375 376 IPSEC_ISTAT(sproto, ESP_STAT_PDROPS, 377 AH_STAT_PDROPS, 378 IPCOMP_STAT_PDROPS); 379 error = EACCES; 380 goto bad; 381 } 382 #endif /*XXX*/ 383 } 384 #if INET6 385 /* IPv6-in-IP encapsulation. */ 386 if (prot == IPPROTO_IPV6) { 387 struct ip6_hdr ip6n; 388 389 /* ip6n will now contain the inner IPv6 header. */ 390 m_copydata(m, ip->ip_hl << 2, sizeof(struct ip6_hdr), &ip6n); 391 392 #ifdef notyet 393 /* 394 * Check that the inner source address is the same as 395 * the proxy address, if available. 396 */ 397 if ((saidx->proxy.sa.sa_family == AF_INET6 && 398 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) && 399 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src, 400 &saidx->proxy.sin6.sin6_addr)) || 401 (saidx->proxy.sa.sa_family != AF_INET6 && 402 saidx->proxy.sa.sa_family != 0)) { 403 404 DPRINTF(("ipsec4_common_input_cb: inner " 405 "source address %s doesn't correspond to " 406 "expected proxy source %s, SA %s/%08lx\n", 407 ip6_sprintf(&ip6n.ip6_src), 408 ipsec_address(&saidx->proxy), 409 ipsec_address(&saidx->dst), 410 (u_long) ntohl(sav->spi))); 411 412 IPSEC_ISTAT(sproto, ESP_STAT_PDROPS, 413 AH_STAT_PDROPS, 414 IPCOMP_STAT_PDROPS); 415 error = EACCES; 416 goto bad; 417 } 418 #endif /*XXX*/ 419 } 420 #endif /* INET6 */ 421 422 /* 423 * Record what we've done to the packet (under what SA it was 424 * processed). If we've been passed an mtag, it means the packet 425 * was already processed by an ethernet/crypto combo card and 426 * thus has a tag attached with all the right information, but 427 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to 428 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type. 429 */ 430 if (mt == NULL && sproto != IPPROTO_IPCOMP) { 431 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE, 432 sizeof(struct tdb_ident), M_NOWAIT); 433 if (mtag == NULL) { 434 DPRINTF(("ipsec4_common_input_cb: failed to get tag\n")); 435 IPSEC_ISTAT(sproto, ESP_STAT_HDROPS, 436 AH_STAT_HDROPS, IPCOMP_STAT_HDROPS); 437 error = ENOMEM; 438 goto bad; 439 } 440 441 tdbi = (struct tdb_ident *)(mtag + 1); 442 memcpy(&tdbi->dst, &saidx->dst, saidx->dst.sa.sa_len); 443 tdbi->proto = sproto; 444 tdbi->spi = sav->spi; 445 446 m_tag_prepend(m, mtag); 447 } else { 448 if (mt != NULL) 449 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE; 450 /* XXX do we need to mark m_flags??? */ 451 } 452 453 key_sa_recordxfer(sav, m); /* record data transfer */ 454 455 /* 456 * Re-dispatch via software interrupt. 457 */ 458 if (!IF_HANDOFF(&ipintrq, m, NULL)) { 459 IPSEC_ISTAT(sproto, ESP_STAT_QFULL, AH_STAT_QFULL, 460 IPCOMP_STAT_QFULL); 461 462 DPRINTF(("ipsec4_common_input_cb: queue full; " 463 "proto %u packet dropped\n", sproto)); 464 return ENOBUFS; 465 } 466 schednetisr(NETISR_IP); 467 return 0; 468 bad: 469 m_freem(m); 470 return error; 471 } 472 #endif /* INET */ 473 474 #ifdef INET6 475 /* IPv6 AH wrapper. */ 476 int 477 ipsec6_common_input(struct mbuf **mp, int *offp, int proto) 478 { 479 int l = 0; 480 int protoff, nxt; 481 struct ip6_ext ip6e; 482 483 if (*offp < sizeof(struct ip6_hdr)) { 484 DPRINTF(("ipsec6_common_input: bad offset %u\n", *offp)); 485 IPSEC_ISTAT(proto, ESP_STAT_HDROPS, AH_STAT_HDROPS, 486 IPCOMP_STAT_HDROPS); 487 m_freem(*mp); 488 return IPPROTO_DONE; 489 } else if (*offp == sizeof(struct ip6_hdr)) { 490 protoff = offsetof(struct ip6_hdr, ip6_nxt); 491 } else { 492 /* Chase down the header chain... */ 493 protoff = sizeof(struct ip6_hdr); 494 nxt = (mtod(*mp, struct ip6_hdr *))->ip6_nxt; 495 496 do { 497 protoff += l; 498 m_copydata(*mp, protoff, sizeof(ip6e), &ip6e); 499 500 if (nxt == IPPROTO_AH) 501 l = (ip6e.ip6e_len + 2) << 2; 502 else 503 l = (ip6e.ip6e_len + 1) << 3; 504 IPSEC_ASSERT(l > 0, 505 ("ipsec6_common_input: l went zero or negative")); 506 507 nxt = ip6e.ip6e_nxt; 508 } while (protoff + l < *offp); 509 510 /* Malformed packet check */ 511 if (protoff + l != *offp) { 512 DPRINTF(("ipsec6_common_input: bad packet header chain, " 513 "protoff %u, l %u, off %u\n", protoff, l, *offp)); 514 IPSEC_ISTAT(proto, ESP_STAT_HDROPS, 515 AH_STAT_HDROPS, 516 IPCOMP_STAT_HDROPS); 517 m_freem(*mp); 518 *mp = NULL; 519 return IPPROTO_DONE; 520 } 521 protoff += offsetof(struct ip6_ext, ip6e_nxt); 522 } 523 (void) ipsec_common_input(*mp, *offp, protoff, AF_INET6, proto); 524 return IPPROTO_DONE; 525 } 526 527 /* 528 * NB: ipsec_netbsd.c has a duplicate definition of esp6_ctlinput(), 529 * with slightly ore recent multicast tests. These should be merged. 530 * For now, ifdef accordingly. 531 */ 532 #ifdef __FreeBSD__ 533 void 534 esp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 535 { 536 if (sa->sa_family != AF_INET6 || 537 sa->sa_len != sizeof(struct sockaddr_in6)) 538 return; 539 if ((unsigned)cmd >= PRC_NCMDS) 540 return; 541 542 /* if the parameter is from icmp6, decode it. */ 543 if (d != NULL) { 544 struct ip6ctlparam *ip6cp = (struct ip6ctlparam *)d; 545 struct mbuf *m = ip6cp->ip6c_m; 546 int off = ip6cp->ip6c_off; 547 548 struct ip6ctlparam ip6cp1; 549 550 /* 551 * Notify the error to all possible sockets via pfctlinput2. 552 * Since the upper layer information (such as protocol type, 553 * source and destination ports) is embedded in the encrypted 554 * data and might have been cut, we can't directly call 555 * an upper layer ctlinput function. However, the pcbnotify 556 * function will consider source and destination addresses 557 * as well as the flow info value, and may be able to find 558 * some PCB that should be notified. 559 * Although pfctlinput2 will call esp6_ctlinput(), there is 560 * no possibility of an infinite loop of function calls, 561 * because we don't pass the inner IPv6 header. 562 */ 563 memset(&ip6cp1, 0, sizeof(ip6cp1)); 564 ip6cp1.ip6c_src = ip6cp->ip6c_src; 565 pfctlinput2(cmd, sa, &ip6cp1); 566 567 /* 568 * Then go to special cases that need ESP header information. 569 * XXX: We assume that when ip6 is non NULL, 570 * M and OFF are valid. 571 */ 572 573 if (cmd == PRC_MSGSIZE) { 574 struct secasvar *sav; 575 u_int32_t spi; 576 int valid; 577 578 /* check header length before using m_copydata */ 579 if (m->m_pkthdr.len < off + sizeof (struct esp)) 580 return; 581 m_copydata(m, off + offsetof(struct esp, esp_spi), 582 sizeof(u_int32_t), &spi); 583 /* 584 * Check to see if we have a valid SA corresponding to 585 * the address in the ICMP message payload. 586 */ 587 sav = KEY_ALLOCSA((union sockaddr_union *)sa, 588 IPPROTO_ESP, spi); 589 valid = (sav != NULL); 590 if (sav) 591 KEY_FREESAV(&sav); 592 593 /* XXX Further validation? */ 594 595 /* 596 * Depending on whether the SA is "valid" and 597 * routing table size (mtudisc_{hi,lo}wat), we will: 598 * - recalcurate the new MTU and create the 599 * corresponding routing entry, or 600 * - ignore the MTU change notification. 601 */ 602 icmp6_mtudisc_update(ip6cp, valid); 603 } 604 } else { 605 /* we normally notify any pcb here */ 606 } 607 } 608 #endif /* __FreeBSD__ */ 609 610 extern const struct ip6protosw inet6sw[]; 611 extern u_char ip6_protox[]; 612 613 /* 614 * IPsec input callback, called by the transform callback. Takes care of 615 * filtering and other sanity checks on the processed packet. 616 */ 617 int 618 ipsec6_common_input_cb(struct mbuf *m, struct secasvar *sav, int skip, int protoff, 619 struct m_tag *mt) 620 { 621 int af, sproto; 622 struct ip6_hdr *ip6; 623 struct m_tag *mtag; 624 struct tdb_ident *tdbi; 625 struct secasindex *saidx; 626 int nxt; 627 u_int8_t prot, nxt8; 628 int error, nest; 629 630 IPSEC_ASSERT(m != NULL, ("ipsec6_common_input_cb: null mbuf")); 631 IPSEC_ASSERT(sav != NULL, ("ipsec6_common_input_cb: null SA")); 632 IPSEC_ASSERT(sav->sah != NULL, ("ipsec6_common_input_cb: null SAH")); 633 saidx = &sav->sah->saidx; 634 af = saidx->dst.sa.sa_family; 635 IPSEC_ASSERT(af == AF_INET6, 636 ("ipsec6_common_input_cb: unexpected af %u", af)); 637 sproto = saidx->proto; 638 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH || 639 sproto == IPPROTO_IPCOMP, 640 ("ipsec6_common_input_cb: unexpected security protocol %u", 641 sproto)); 642 643 /* Sanity check */ 644 if (m == NULL) { 645 DPRINTF(("ipsec6_common_input_cb: null mbuf")); 646 IPSEC_ISTAT(sproto, ESP_STAT_BADKCR, AH_STAT_BADKCR, 647 IPCOMP_STAT_BADKCR); 648 error = EINVAL; 649 goto bad; 650 } 651 652 /* Fix IPv6 header */ 653 if (m->m_len < sizeof(struct ip6_hdr) && 654 (m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 655 656 DPRINTF(("ipsec6_common_input_cb: processing failed " 657 "for SA %s/%08lx\n", ipsec_address(&sav->sah->saidx.dst), 658 (u_long) ntohl(sav->spi))); 659 660 IPSEC_ISTAT(sproto, ESP_STAT_HDROPS, AH_STAT_HDROPS, 661 IPCOMP_STAT_HDROPS); 662 error = EACCES; 663 goto bad; 664 } 665 666 ip6 = mtod(m, struct ip6_hdr *); 667 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 668 669 /* Save protocol */ 670 m_copydata(m, protoff, 1, &prot); 671 672 #ifdef INET 673 /* IP-in-IP encapsulation */ 674 if (prot == IPPROTO_IPIP) { 675 struct ip ipn; 676 677 /* ipn will now contain the inner IPv4 header */ 678 m_copydata(m, skip, sizeof(struct ip), &ipn); 679 680 #ifdef notyet 681 /* 682 * Check that the inner source address is the same as 683 * the proxy address, if available. 684 */ 685 if ((saidx->proxy.sa.sa_family == AF_INET && 686 saidx->proxy.sin.sin_addr.s_addr != INADDR_ANY && 687 ipn.ip_src.s_addr != saidx->proxy.sin.sin_addr.s_addr) || 688 (saidx->proxy.sa.sa_family != AF_INET && 689 saidx->proxy.sa.sa_family != 0)) { 690 691 DPRINTF(("ipsec6_common_input_cb: inner " 692 "source address %s doesn't correspond to " 693 "expected proxy source %s, SA %s/%08lx\n", 694 inet_ntoa4(ipn.ip_src), 695 ipsec_address(&saidx->proxy), 696 ipsec_address(&saidx->dst), 697 (u_long) ntohl(sav->spi))); 698 699 IPSEC_ISTAT(sproto, ESP_STAT_PDROPS, 700 AH_STAT_PDROPS, IPCOMP_STAT_PDROPS); 701 error = EACCES; 702 goto bad; 703 } 704 #endif /*XXX*/ 705 } 706 #endif /* INET */ 707 708 /* IPv6-in-IP encapsulation */ 709 if (prot == IPPROTO_IPV6) { 710 struct ip6_hdr ip6n; 711 712 /* ip6n will now contain the inner IPv6 header. */ 713 m_copydata(m, skip, sizeof(struct ip6_hdr), &ip6n); 714 715 #ifdef notyet 716 /* 717 * Check that the inner source address is the same as 718 * the proxy address, if available. 719 */ 720 if ((saidx->proxy.sa.sa_family == AF_INET6 && 721 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) && 722 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src, 723 &saidx->proxy.sin6.sin6_addr)) || 724 (saidx->proxy.sa.sa_family != AF_INET6 && 725 saidx->proxy.sa.sa_family != 0)) { 726 727 DPRINTF(("ipsec6_common_input_cb: inner " 728 "source address %s doesn't correspond to " 729 "expected proxy source %s, SA %s/%08lx\n", 730 ip6_sprintf(&ip6n.ip6_src), 731 ipsec_address(&saidx->proxy), 732 ipsec_address(&saidx->dst), 733 (u_long) ntohl(sav->spi))); 734 735 IPSEC_ISTAT(sproto, ESP_STAT_PDROPS, 736 AH_STAT_PDROPS, IPCOMP_STAT_PDROPS); 737 error = EACCES; 738 goto bad; 739 } 740 #endif /*XXX*/ 741 } 742 743 /* 744 * Record what we've done to the packet (under what SA it was 745 * processed). If we've been passed an mtag, it means the packet 746 * was already processed by an ethernet/crypto combo card and 747 * thus has a tag attached with all the right information, but 748 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to 749 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type. 750 */ 751 if (mt == NULL && sproto != IPPROTO_IPCOMP) { 752 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE, 753 sizeof(struct tdb_ident), M_NOWAIT); 754 if (mtag == NULL) { 755 DPRINTF(("ipsec_common_input_cb: failed to " 756 "get tag\n")); 757 IPSEC_ISTAT(sproto, ESP_STAT_HDROPS, 758 AH_STAT_HDROPS, IPCOMP_STAT_HDROPS); 759 error = ENOMEM; 760 goto bad; 761 } 762 763 tdbi = (struct tdb_ident *)(mtag + 1); 764 memcpy(&tdbi->dst, &saidx->dst, sizeof(union sockaddr_union)); 765 tdbi->proto = sproto; 766 tdbi->spi = sav->spi; 767 768 m_tag_prepend(m, mtag); 769 } else { 770 if (mt != NULL) 771 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE; 772 /* XXX do we need to mark m_flags??? */ 773 } 774 775 key_sa_recordxfer(sav, m); 776 777 /* Retrieve new protocol */ 778 m_copydata(m, protoff, sizeof(u_int8_t), &nxt8); 779 780 /* 781 * See the end of ip6_input for this logic. 782 * IPPROTO_IPV[46] case will be processed just like other ones 783 */ 784 nest = 0; 785 nxt = nxt8; 786 while (nxt != IPPROTO_DONE) { 787 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 788 IP6_STATINC(IP6_STAT_TOOMANYHDR); 789 error = EINVAL; 790 goto bad; 791 } 792 793 /* 794 * Protection against faulty packet - there should be 795 * more sanity checks in header chain processing. 796 */ 797 if (m->m_pkthdr.len < skip) { 798 IP6_STATINC(IP6_STAT_TOOSHORT); 799 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 800 error = EINVAL; 801 goto bad; 802 } 803 /* 804 * Enforce IPsec policy checking if we are seeing last header. 805 * note that we do not visit this with protocols with pcb layer 806 * code - like udp/tcp/raw ip. 807 */ 808 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 809 ipsec6_in_reject(m, NULL)) { 810 error = EINVAL; 811 goto bad; 812 } 813 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &skip, nxt); 814 } 815 return 0; 816 bad: 817 if (m) 818 m_freem(m); 819 return error; 820 } 821 #endif /* INET6 */ 822