1 /* $FreeBSD$ */ 2 /* $OpenBSD: ipsec_input.c,v 1.63 2003/02/20 18:35:43 deraadt Exp $ */ 3 /* 4 * The authors of this code are John Ioannidis (ji@tla.org), 5 * Angelos D. Keromytis (kermit@csd.uch.gr) and 6 * Niels Provos (provos@physnet.uni-hamburg.de). 7 * 8 * This code was written by John Ioannidis for BSD/OS in Athens, Greece, 9 * in November 1995. 10 * 11 * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996, 12 * by Angelos D. Keromytis. 13 * 14 * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis 15 * and Niels Provos. 16 * 17 * Additional features in 1999 by Angelos D. Keromytis. 18 * 19 * Copyright (C) 1995, 1996, 1997, 1998, 1999 by John Ioannidis, 20 * Angelos D. Keromytis and Niels Provos. 21 * Copyright (c) 2001, Angelos D. Keromytis. 22 * 23 * Permission to use, copy, and modify this software with or without fee 24 * is hereby granted, provided that this entire notice is included in 25 * all copies of any software which is or includes a copy or 26 * modification of this software. 27 * You may use this code under the GNU public license if you so wish. Please 28 * contribute changes back to the authors under this freer than GPL license 29 * so that we may further the use of strong encryption without limitations to 30 * all. 31 * 32 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR 33 * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY 34 * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE 35 * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR 36 * PURPOSE. 37 */ 38 39 /* 40 * IPsec input processing. 41 */ 42 43 #include "opt_inet.h" 44 #include "opt_inet6.h" 45 #include "opt_ipsec.h" 46 47 #include <sys/param.h> 48 #include <sys/systm.h> 49 #include <sys/malloc.h> 50 #include <sys/mbuf.h> 51 #include <sys/domain.h> 52 #include <sys/protosw.h> 53 #include <sys/socket.h> 54 #include <sys/errno.h> 55 #include <sys/syslog.h> 56 57 #include <net/if.h> 58 #include <net/route.h> 59 #include <net/netisr.h> 60 61 #include <netinet/in.h> 62 #include <netinet/in_systm.h> 63 #include <netinet/ip.h> 64 #include <netinet/ip_var.h> 65 #include <netinet/in_var.h> 66 67 #include <netinet/ip6.h> 68 #ifdef INET6 69 #include <netinet6/ip6_var.h> 70 #endif 71 #include <netinet/in_pcb.h> 72 #ifdef INET6 73 #include <netinet/icmp6.h> 74 #endif 75 76 #include <netipsec/ipsec.h> 77 #ifdef INET6 78 #include <netipsec/ipsec6.h> 79 #endif 80 #include <netipsec/ah_var.h> 81 #include <netipsec/esp.h> 82 #include <netipsec/esp_var.h> 83 #include <netipsec/ipcomp_var.h> 84 85 #include <netipsec/key.h> 86 #include <netipsec/keydb.h> 87 88 #include <netipsec/xform.h> 89 #include <netinet6/ip6protosw.h> 90 91 #include <machine/in_cksum.h> 92 #include <machine/stdarg.h> 93 94 #define IPSEC_ISTAT(p,x,y,z) ((p) == IPPROTO_ESP ? (x)++ : \ 95 (p) == IPPROTO_AH ? (y)++ : (z)++) 96 97 static void ipsec4_common_ctlinput(int, struct sockaddr *, void *, int); 98 99 /* 100 * ipsec_common_input gets called when an IPsec-protected packet 101 * is received by IPv4 or IPv6. It's job is to find the right SA 102 # and call the appropriate transform. The transform callback 103 * takes care of further processing (like ingress filtering). 104 */ 105 static int 106 ipsec_common_input(struct mbuf *m, int skip, int protoff, int af, int sproto) 107 { 108 union sockaddr_union dst_address; 109 struct secasvar *sav; 110 u_int32_t spi; 111 int error; 112 113 IPSEC_ISTAT(sproto, espstat.esps_input, ahstat.ahs_input, 114 ipcompstat.ipcomps_input); 115 116 IPSEC_ASSERT(m != NULL, ("null packet")); 117 118 if ((sproto == IPPROTO_ESP && !esp_enable) || 119 (sproto == IPPROTO_AH && !ah_enable) || 120 (sproto == IPPROTO_IPCOMP && !ipcomp_enable)) { 121 m_freem(m); 122 IPSEC_ISTAT(sproto, espstat.esps_pdrops, ahstat.ahs_pdrops, 123 ipcompstat.ipcomps_pdrops); 124 return EOPNOTSUPP; 125 } 126 127 if (m->m_pkthdr.len - skip < 2 * sizeof (u_int32_t)) { 128 m_freem(m); 129 IPSEC_ISTAT(sproto, espstat.esps_hdrops, ahstat.ahs_hdrops, 130 ipcompstat.ipcomps_hdrops); 131 DPRINTF(("%s: packet too small\n", __func__)); 132 return EINVAL; 133 } 134 135 /* Retrieve the SPI from the relevant IPsec header */ 136 if (sproto == IPPROTO_ESP) 137 m_copydata(m, skip, sizeof(u_int32_t), (caddr_t) &spi); 138 else if (sproto == IPPROTO_AH) 139 m_copydata(m, skip + sizeof(u_int32_t), sizeof(u_int32_t), 140 (caddr_t) &spi); 141 else if (sproto == IPPROTO_IPCOMP) { 142 u_int16_t cpi; 143 m_copydata(m, skip + sizeof(u_int16_t), sizeof(u_int16_t), 144 (caddr_t) &cpi); 145 spi = ntohl(htons(cpi)); 146 } 147 148 /* 149 * Find the SA and (indirectly) call the appropriate 150 * kernel crypto routine. The resulting mbuf chain is a valid 151 * IP packet ready to go through input processing. 152 */ 153 bzero(&dst_address, sizeof (dst_address)); 154 dst_address.sa.sa_family = af; 155 switch (af) { 156 #ifdef INET 157 case AF_INET: 158 dst_address.sin.sin_len = sizeof(struct sockaddr_in); 159 m_copydata(m, offsetof(struct ip, ip_dst), 160 sizeof(struct in_addr), 161 (caddr_t) &dst_address.sin.sin_addr); 162 break; 163 #endif /* INET */ 164 #ifdef INET6 165 case AF_INET6: 166 dst_address.sin6.sin6_len = sizeof(struct sockaddr_in6); 167 m_copydata(m, offsetof(struct ip6_hdr, ip6_dst), 168 sizeof(struct in6_addr), 169 (caddr_t) &dst_address.sin6.sin6_addr); 170 break; 171 #endif /* INET6 */ 172 default: 173 DPRINTF(("%s: unsupported protocol family %u\n", __func__, af)); 174 m_freem(m); 175 IPSEC_ISTAT(sproto, espstat.esps_nopf, ahstat.ahs_nopf, 176 ipcompstat.ipcomps_nopf); 177 return EPFNOSUPPORT; 178 } 179 180 /* NB: only pass dst since key_allocsa follows RFC2401 */ 181 sav = KEY_ALLOCSA(&dst_address, sproto, spi); 182 if (sav == NULL) { 183 DPRINTF(("%s: no key association found for SA %s/%08lx/%u\n", 184 __func__, ipsec_address(&dst_address), 185 (u_long) ntohl(spi), sproto)); 186 IPSEC_ISTAT(sproto, espstat.esps_notdb, ahstat.ahs_notdb, 187 ipcompstat.ipcomps_notdb); 188 m_freem(m); 189 return ENOENT; 190 } 191 192 if (sav->tdb_xform == NULL) { 193 DPRINTF(("%s: attempted to use uninitialized SA %s/%08lx/%u\n", 194 __func__, ipsec_address(&dst_address), 195 (u_long) ntohl(spi), sproto)); 196 IPSEC_ISTAT(sproto, espstat.esps_noxform, ahstat.ahs_noxform, 197 ipcompstat.ipcomps_noxform); 198 KEY_FREESAV(&sav); 199 m_freem(m); 200 return ENXIO; 201 } 202 203 /* 204 * Call appropriate transform and return -- callback takes care of 205 * everything else. 206 */ 207 error = (*sav->tdb_xform->xf_input)(m, sav, skip, protoff); 208 KEY_FREESAV(&sav); 209 return error; 210 } 211 212 #ifdef INET 213 /* 214 * Common input handler for IPv4 AH, ESP, and IPCOMP. 215 */ 216 int 217 ipsec4_common_input(struct mbuf *m, ...) 218 { 219 va_list ap; 220 int off, nxt; 221 222 va_start(ap, m); 223 off = va_arg(ap, int); 224 nxt = va_arg(ap, int); 225 va_end(ap); 226 227 return ipsec_common_input(m, off, offsetof(struct ip, ip_p), 228 AF_INET, nxt); 229 } 230 231 void 232 ah4_input(struct mbuf *m, int off) 233 { 234 ipsec4_common_input(m, off, IPPROTO_AH); 235 } 236 void 237 ah4_ctlinput(int cmd, struct sockaddr *sa, void *v) 238 { 239 if (sa->sa_family == AF_INET && 240 sa->sa_len == sizeof(struct sockaddr_in)) 241 ipsec4_common_ctlinput(cmd, sa, v, IPPROTO_AH); 242 } 243 244 void 245 esp4_input(struct mbuf *m, int off) 246 { 247 ipsec4_common_input(m, off, IPPROTO_ESP); 248 } 249 void 250 esp4_ctlinput(int cmd, struct sockaddr *sa, void *v) 251 { 252 if (sa->sa_family == AF_INET && 253 sa->sa_len == sizeof(struct sockaddr_in)) 254 ipsec4_common_ctlinput(cmd, sa, v, IPPROTO_ESP); 255 } 256 257 void 258 ipcomp4_input(struct mbuf *m, int off) 259 { 260 ipsec4_common_input(m, off, IPPROTO_IPCOMP); 261 } 262 263 /* 264 * IPsec input callback for INET protocols. 265 * This routine is called as the transform callback. 266 * Takes care of filtering and other sanity checks on 267 * the processed packet. 268 */ 269 int 270 ipsec4_common_input_cb(struct mbuf *m, struct secasvar *sav, 271 int skip, int protoff, struct m_tag *mt) 272 { 273 int prot, af, sproto; 274 struct ip *ip; 275 struct m_tag *mtag; 276 struct tdb_ident *tdbi; 277 struct secasindex *saidx; 278 int error; 279 280 IPSEC_SPLASSERT_SOFTNET(__func__); 281 282 IPSEC_ASSERT(m != NULL, ("null mbuf")); 283 IPSEC_ASSERT(sav != NULL, ("null SA")); 284 IPSEC_ASSERT(sav->sah != NULL, ("null SAH")); 285 saidx = &sav->sah->saidx; 286 af = saidx->dst.sa.sa_family; 287 IPSEC_ASSERT(af == AF_INET, ("unexpected af %u", af)); 288 sproto = saidx->proto; 289 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH || 290 sproto == IPPROTO_IPCOMP, 291 ("unexpected security protocol %u", sproto)); 292 293 /* Sanity check */ 294 if (m == NULL) { 295 DPRINTF(("%s: null mbuf", __func__)); 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(("%s: processing failed for SA %s/%08lx\n", 306 __func__, ipsec_address(&sav->sah->saidx.dst), 307 (u_long) ntohl(sav->spi))); 308 IPSEC_ISTAT(sproto, espstat.esps_hdrops, ahstat.ahs_hdrops, 309 ipcompstat.ipcomps_hdrops); 310 error = ENOBUFS; 311 goto bad; 312 } 313 314 ip = mtod(m, struct ip *); 315 ip->ip_len = htons(m->m_pkthdr.len); 316 ip->ip_off = htons(ip->ip_off); 317 ip->ip_sum = 0; 318 ip->ip_sum = in_cksum(m, ip->ip_hl << 2); 319 } else { 320 ip = mtod(m, struct ip *); 321 } 322 prot = ip->ip_p; 323 324 /* IP-in-IP encapsulation */ 325 if (prot == IPPROTO_IPIP) { 326 struct ip ipn; 327 328 if (m->m_pkthdr.len - skip < sizeof(struct ip)) { 329 IPSEC_ISTAT(sproto, espstat.esps_hdrops, 330 ahstat.ahs_hdrops, 331 ipcompstat.ipcomps_hdrops); 332 error = EINVAL; 333 goto bad; 334 } 335 /* ipn will now contain the inner IPv4 header */ 336 m_copydata(m, ip->ip_hl << 2, sizeof(struct ip), 337 (caddr_t) &ipn); 338 339 #ifdef notyet 340 /* XXX PROXY address isn't recorded in SAH */ 341 /* 342 * Check that the inner source address is the same as 343 * the proxy address, if available. 344 */ 345 if ((saidx->proxy.sa.sa_family == AF_INET && 346 saidx->proxy.sin.sin_addr.s_addr != 347 INADDR_ANY && 348 ipn.ip_src.s_addr != 349 saidx->proxy.sin.sin_addr.s_addr) || 350 (saidx->proxy.sa.sa_family != AF_INET && 351 saidx->proxy.sa.sa_family != 0)) { 352 353 DPRINTF(("%s: inner source address %s doesn't " 354 "correspond to expected proxy source %s, " 355 "SA %s/%08lx\n", __func__, 356 inet_ntoa4(ipn.ip_src), 357 ipsp_address(saidx->proxy), 358 ipsp_address(saidx->dst), 359 (u_long) ntohl(sav->spi))); 360 361 IPSEC_ISTAT(sproto, espstat.esps_pdrops, 362 ahstat.ahs_pdrops, 363 ipcompstat.ipcomps_pdrops); 364 error = EACCES; 365 goto bad; 366 } 367 #endif /*XXX*/ 368 } 369 #if INET6 370 /* IPv6-in-IP encapsulation. */ 371 if (prot == IPPROTO_IPV6) { 372 struct ip6_hdr ip6n; 373 374 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) { 375 IPSEC_ISTAT(sproto, espstat.esps_hdrops, 376 ahstat.ahs_hdrops, 377 ipcompstat.ipcomps_hdrops); 378 error = EINVAL; 379 goto bad; 380 } 381 /* ip6n will now contain the inner IPv6 header. */ 382 m_copydata(m, ip->ip_hl << 2, sizeof(struct ip6_hdr), 383 (caddr_t) &ip6n); 384 385 #ifdef notyet 386 /* 387 * Check that the inner source address is the same as 388 * the proxy address, if available. 389 */ 390 if ((saidx->proxy.sa.sa_family == AF_INET6 && 391 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) && 392 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src, 393 &saidx->proxy.sin6.sin6_addr)) || 394 (saidx->proxy.sa.sa_family != AF_INET6 && 395 saidx->proxy.sa.sa_family != 0)) { 396 397 DPRINTF(("%s: inner source address %s doesn't " 398 "correspond to expected proxy source %s, " 399 "SA %s/%08lx\n", __func__, 400 ip6_sprintf(&ip6n.ip6_src), 401 ipsec_address(&saidx->proxy), 402 ipsec_address(&saidx->dst), 403 (u_long) ntohl(sav->spi))); 404 405 IPSEC_ISTAT(sproto, espstat.esps_pdrops, 406 ahstat.ahs_pdrops, 407 ipcompstat.ipcomps_pdrops); 408 error = EACCES; 409 goto bad; 410 } 411 #endif /*XXX*/ 412 } 413 #endif /* INET6 */ 414 415 /* 416 * Record what we've done to the packet (under what SA it was 417 * processed). If we've been passed an mtag, it means the packet 418 * was already processed by an ethernet/crypto combo card and 419 * thus has a tag attached with all the right information, but 420 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to 421 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type. 422 */ 423 if (mt == NULL && sproto != IPPROTO_IPCOMP) { 424 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE, 425 sizeof(struct tdb_ident), M_NOWAIT); 426 if (mtag == NULL) { 427 DPRINTF(("%s: failed to get tag\n", __func__)); 428 IPSEC_ISTAT(sproto, espstat.esps_hdrops, 429 ahstat.ahs_hdrops, ipcompstat.ipcomps_hdrops); 430 error = ENOMEM; 431 goto bad; 432 } 433 434 tdbi = (struct tdb_ident *)(mtag + 1); 435 bcopy(&saidx->dst, &tdbi->dst, saidx->dst.sa.sa_len); 436 tdbi->proto = sproto; 437 tdbi->spi = sav->spi; 438 439 m_tag_prepend(m, mtag); 440 } else { 441 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE; 442 /* XXX do we need to mark m_flags??? */ 443 } 444 445 key_sa_recordxfer(sav, m); /* record data transfer */ 446 447 /* 448 * Re-dispatch via software interrupt. 449 */ 450 if ((error = netisr_queue(NETISR_IP, m))) { 451 IPSEC_ISTAT(sproto, espstat.esps_qfull, ahstat.ahs_qfull, 452 ipcompstat.ipcomps_qfull); 453 454 DPRINTF(("%s: queue full; proto %u packet dropped\n", 455 __func__, sproto)); 456 return error; 457 } 458 return 0; 459 bad: 460 m_freem(m); 461 return error; 462 } 463 464 void 465 ipsec4_common_ctlinput(int cmd, struct sockaddr *sa, void *v, int proto) 466 { 467 /* XXX nothing just yet */ 468 } 469 #endif /* INET */ 470 471 #ifdef INET6 472 /* IPv6 AH wrapper. */ 473 int 474 ipsec6_common_input(struct mbuf **mp, int *offp, int proto) 475 { 476 int l = 0; 477 int protoff; 478 struct ip6_ext ip6e; 479 480 if (*offp < sizeof(struct ip6_hdr)) { 481 DPRINTF(("%s: bad offset %u\n", __func__, *offp)); 482 return IPPROTO_DONE; 483 } else if (*offp == sizeof(struct ip6_hdr)) { 484 protoff = offsetof(struct ip6_hdr, ip6_nxt); 485 } else { 486 /* Chase down the header chain... */ 487 protoff = sizeof(struct ip6_hdr); 488 489 do { 490 protoff += l; 491 m_copydata(*mp, protoff, sizeof(ip6e), 492 (caddr_t) &ip6e); 493 494 if (ip6e.ip6e_nxt == IPPROTO_AH) 495 l = (ip6e.ip6e_len + 2) << 2; 496 else 497 l = (ip6e.ip6e_len + 1) << 3; 498 IPSEC_ASSERT(l > 0, ("l went zero or negative")); 499 } while (protoff + l < *offp); 500 501 /* Malformed packet check */ 502 if (protoff + l != *offp) { 503 DPRINTF(("%s: bad packet header chain, protoff %u, " 504 "l %u, off %u\n", __func__, protoff, l, *offp)); 505 IPSEC_ISTAT(proto, espstat.esps_hdrops, 506 ahstat.ahs_hdrops, 507 ipcompstat.ipcomps_hdrops); 508 m_freem(*mp); 509 *mp = NULL; 510 return IPPROTO_DONE; 511 } 512 protoff += offsetof(struct ip6_ext, ip6e_nxt); 513 } 514 (void) ipsec_common_input(*mp, *offp, protoff, AF_INET6, proto); 515 return IPPROTO_DONE; 516 } 517 518 /* 519 * IPsec input callback, called by the transform callback. Takes care of 520 * filtering and other sanity checks on the processed packet. 521 */ 522 int 523 ipsec6_common_input_cb(struct mbuf *m, struct secasvar *sav, int skip, int protoff, 524 struct m_tag *mt) 525 { 526 int prot, af, sproto; 527 struct ip6_hdr *ip6; 528 struct m_tag *mtag; 529 struct tdb_ident *tdbi; 530 struct secasindex *saidx; 531 int nxt; 532 u_int8_t nxt8; 533 int error, nest; 534 535 IPSEC_ASSERT(m != NULL, ("null mbuf")); 536 IPSEC_ASSERT(sav != NULL, ("null SA")); 537 IPSEC_ASSERT(sav->sah != NULL, ("null SAH")); 538 saidx = &sav->sah->saidx; 539 af = saidx->dst.sa.sa_family; 540 IPSEC_ASSERT(af == AF_INET6, ("unexpected af %u", af)); 541 sproto = saidx->proto; 542 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH || 543 sproto == IPPROTO_IPCOMP, 544 ("unexpected security protocol %u", sproto)); 545 546 /* Sanity check */ 547 if (m == NULL) { 548 DPRINTF(("%s: null mbuf", __func__)); 549 IPSEC_ISTAT(sproto, espstat.esps_badkcr, ahstat.ahs_badkcr, 550 ipcompstat.ipcomps_badkcr); 551 error = EINVAL; 552 goto bad; 553 } 554 555 /* Fix IPv6 header */ 556 if (m->m_len < sizeof(struct ip6_hdr) && 557 (m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 558 559 DPRINTF(("%s: processing failed for SA %s/%08lx\n", 560 __func__, ipsec_address(&sav->sah->saidx.dst), 561 (u_long) ntohl(sav->spi))); 562 563 IPSEC_ISTAT(sproto, espstat.esps_hdrops, ahstat.ahs_hdrops, 564 ipcompstat.ipcomps_hdrops); 565 error = EACCES; 566 goto bad; 567 } 568 569 ip6 = mtod(m, struct ip6_hdr *); 570 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 571 572 /* Save protocol */ 573 m_copydata(m, protoff, 1, (unsigned char *) &prot); 574 575 #ifdef INET 576 /* IP-in-IP encapsulation */ 577 if (prot == IPPROTO_IPIP) { 578 struct ip ipn; 579 580 if (m->m_pkthdr.len - skip < sizeof(struct ip)) { 581 IPSEC_ISTAT(sproto, espstat.esps_hdrops, 582 ahstat.ahs_hdrops, 583 ipcompstat.ipcomps_hdrops); 584 error = EINVAL; 585 goto bad; 586 } 587 /* ipn will now contain the inner IPv4 header */ 588 m_copydata(m, skip, sizeof(struct ip), (caddr_t) &ipn); 589 590 #ifdef notyet 591 /* 592 * Check that the inner source address is the same as 593 * the proxy address, if available. 594 */ 595 if ((saidx->proxy.sa.sa_family == AF_INET && 596 saidx->proxy.sin.sin_addr.s_addr != INADDR_ANY && 597 ipn.ip_src.s_addr != saidx->proxy.sin.sin_addr.s_addr) || 598 (saidx->proxy.sa.sa_family != AF_INET && 599 saidx->proxy.sa.sa_family != 0)) { 600 601 DPRINTF(("%s: inner source address %s doesn't " 602 "correspond to expected proxy source %s, " 603 "SA %s/%08lx\n", __func__, 604 inet_ntoa4(ipn.ip_src), 605 ipsec_address(&saidx->proxy), 606 ipsec_address(&saidx->dst), 607 (u_long) ntohl(sav->spi))); 608 609 IPSEC_ISTATsproto, (espstat.esps_pdrops, 610 ahstat.ahs_pdrops, ipcompstat.ipcomps_pdrops); 611 error = EACCES; 612 goto bad; 613 } 614 #endif /*XXX*/ 615 } 616 #endif /* INET */ 617 618 /* IPv6-in-IP encapsulation */ 619 if (prot == IPPROTO_IPV6) { 620 struct ip6_hdr ip6n; 621 622 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) { 623 IPSEC_ISTAT(sproto, espstat.esps_hdrops, 624 ahstat.ahs_hdrops, 625 ipcompstat.ipcomps_hdrops); 626 error = EINVAL; 627 goto bad; 628 } 629 /* ip6n will now contain the inner IPv6 header. */ 630 m_copydata(m, skip, sizeof(struct ip6_hdr), 631 (caddr_t) &ip6n); 632 633 #ifdef notyet 634 /* 635 * Check that the inner source address is the same as 636 * the proxy address, if available. 637 */ 638 if ((saidx->proxy.sa.sa_family == AF_INET6 && 639 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) && 640 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src, 641 &saidx->proxy.sin6.sin6_addr)) || 642 (saidx->proxy.sa.sa_family != AF_INET6 && 643 saidx->proxy.sa.sa_family != 0)) { 644 645 DPRINTF(("%s: inner source address %s doesn't " 646 "correspond to expected proxy source %s, " 647 "SA %s/%08lx\n", __func__, 648 ip6_sprintf(&ip6n.ip6_src), 649 ipsec_address(&saidx->proxy), 650 ipsec_address(&saidx->dst), 651 (u_long) ntohl(sav->spi))); 652 653 IPSEC_ISTAT(sproto, espstat.esps_pdrops, 654 ahstat.ahs_pdrops, ipcompstat.ipcomps_pdrops); 655 error = EACCES; 656 goto bad; 657 } 658 #endif /*XXX*/ 659 } 660 661 /* 662 * Record what we've done to the packet (under what SA it was 663 * processed). If we've been passed an mtag, it means the packet 664 * was already processed by an ethernet/crypto combo card and 665 * thus has a tag attached with all the right information, but 666 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to 667 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type. 668 */ 669 if (mt == NULL && sproto != IPPROTO_IPCOMP) { 670 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE, 671 sizeof(struct tdb_ident), M_NOWAIT); 672 if (mtag == NULL) { 673 DPRINTF(("%s: failed to get tag\n", __func__)); 674 IPSEC_ISTAT(sproto, espstat.esps_hdrops, 675 ahstat.ahs_hdrops, ipcompstat.ipcomps_hdrops); 676 error = ENOMEM; 677 goto bad; 678 } 679 680 tdbi = (struct tdb_ident *)(mtag + 1); 681 bcopy(&saidx->dst, &tdbi->dst, sizeof(union sockaddr_union)); 682 tdbi->proto = sproto; 683 tdbi->spi = sav->spi; 684 685 m_tag_prepend(m, mtag); 686 } else { 687 if (mt != NULL) 688 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE; 689 /* XXX do we need to mark m_flags??? */ 690 } 691 692 key_sa_recordxfer(sav, m); 693 694 /* Retrieve new protocol */ 695 m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &nxt8); 696 697 /* 698 * See the end of ip6_input for this logic. 699 * IPPROTO_IPV[46] case will be processed just like other ones 700 */ 701 nest = 0; 702 nxt = nxt8; 703 while (nxt != IPPROTO_DONE) { 704 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 705 ip6stat.ip6s_toomanyhdr++; 706 error = EINVAL; 707 goto bad; 708 } 709 710 /* 711 * Protection against faulty packet - there should be 712 * more sanity checks in header chain processing. 713 */ 714 if (m->m_pkthdr.len < skip) { 715 ip6stat.ip6s_tooshort++; 716 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 717 error = EINVAL; 718 goto bad; 719 } 720 /* 721 * Enforce IPsec policy checking if we are seeing last header. 722 * note that we do not visit this with protocols with pcb layer 723 * code - like udp/tcp/raw ip. 724 */ 725 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 726 ipsec6_in_reject(m, NULL)) { 727 error = EINVAL; 728 goto bad; 729 } 730 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &skip, nxt); 731 } 732 return 0; 733 bad: 734 if (m) 735 m_freem(m); 736 return error; 737 } 738 739 void 740 esp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 741 { 742 if (sa->sa_family != AF_INET6 || 743 sa->sa_len != sizeof(struct sockaddr_in6)) 744 return; 745 if ((unsigned)cmd >= PRC_NCMDS) 746 return; 747 748 /* if the parameter is from icmp6, decode it. */ 749 if (d != NULL) { 750 struct ip6ctlparam *ip6cp = (struct ip6ctlparam *)d; 751 struct mbuf *m = ip6cp->ip6c_m; 752 int off = ip6cp->ip6c_off; 753 754 struct ip6ctlparam ip6cp1; 755 756 /* 757 * Notify the error to all possible sockets via pfctlinput2. 758 * Since the upper layer information (such as protocol type, 759 * source and destination ports) is embedded in the encrypted 760 * data and might have been cut, we can't directly call 761 * an upper layer ctlinput function. However, the pcbnotify 762 * function will consider source and destination addresses 763 * as well as the flow info value, and may be able to find 764 * some PCB that should be notified. 765 * Although pfctlinput2 will call esp6_ctlinput(), there is 766 * no possibility of an infinite loop of function calls, 767 * because we don't pass the inner IPv6 header. 768 */ 769 bzero(&ip6cp1, sizeof(ip6cp1)); 770 ip6cp1.ip6c_src = ip6cp->ip6c_src; 771 pfctlinput2(cmd, sa, (void *)&ip6cp1); 772 773 /* 774 * Then go to special cases that need ESP header information. 775 * XXX: We assume that when ip6 is non NULL, 776 * M and OFF are valid. 777 */ 778 779 if (cmd == PRC_MSGSIZE) { 780 struct secasvar *sav; 781 u_int32_t spi; 782 int valid; 783 784 /* check header length before using m_copydata */ 785 if (m->m_pkthdr.len < off + sizeof (struct esp)) 786 return; 787 m_copydata(m, off + offsetof(struct esp, esp_spi), 788 sizeof(u_int32_t), (caddr_t) &spi); 789 /* 790 * Check to see if we have a valid SA corresponding to 791 * the address in the ICMP message payload. 792 */ 793 sav = KEY_ALLOCSA((union sockaddr_union *)sa, 794 IPPROTO_ESP, spi); 795 valid = (sav != NULL); 796 if (sav) 797 KEY_FREESAV(&sav); 798 799 /* XXX Further validation? */ 800 801 /* 802 * Depending on whether the SA is "valid" and 803 * routing table size (mtudisc_{hi,lo}wat), we will: 804 * - recalcurate the new MTU and create the 805 * corresponding routing entry, or 806 * - ignore the MTU change notification. 807 */ 808 icmp6_mtudisc_update(ip6cp, valid); 809 } 810 } else { 811 /* we normally notify any pcb here */ 812 } 813 } 814 #endif /* INET6 */ 815