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sys/netipsec/ipsec_input.c
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1 /* $FreeBSD: releng/10.0/sys/netipsec/ipsec_input.c 252028 2013-06-20 11:44:16Z ae $ */ 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 #include "opt_enc.h" 47 48 #include <sys/param.h> 49 #include <sys/systm.h> 50 #include <sys/malloc.h> 51 #include <sys/mbuf.h> 52 #include <sys/domain.h> 53 #include <sys/protosw.h> 54 #include <sys/socket.h> 55 #include <sys/errno.h> 56 #include <sys/syslog.h> 57 58 #include <net/if.h> 59 #include <net/pfil.h> 60 #include <net/route.h> 61 #include <net/netisr.h> 62 #include <net/vnet.h> 63 64 #include <netinet/in.h> 65 #include <netinet/in_systm.h> 66 #include <netinet/ip.h> 67 #include <netinet/ip_var.h> 68 #include <netinet/in_var.h> 69 70 #include <netinet/ip6.h> 71 #ifdef INET6 72 #include <netinet6/ip6_var.h> 73 #endif 74 #include <netinet/in_pcb.h> 75 #ifdef INET6 76 #include <netinet/icmp6.h> 77 #endif 78 79 #include <netipsec/ipsec.h> 80 #ifdef INET6 81 #include <netipsec/ipsec6.h> 82 #endif 83 #include <netipsec/ah_var.h> 84 #include <netipsec/esp.h> 85 #include <netipsec/esp_var.h> 86 #include <netipsec/ipcomp_var.h> 87 88 #include <netipsec/key.h> 89 #include <netipsec/keydb.h> 90 91 #include <netipsec/xform.h> 92 #include <netinet6/ip6protosw.h> 93 94 #include <machine/in_cksum.h> 95 #include <machine/stdarg.h> 96 97 #ifdef DEV_ENC 98 #include <net/if_enc.h> 99 #endif 100 101 102 #define IPSEC_ISTAT(proto, name) do { \ 103 if ((proto) == IPPROTO_ESP) \ 104 ESPSTAT_INC(esps_##name); \ 105 else if ((proto) == IPPROTO_AH) \ 106 AHSTAT_INC(ahs_##name); \ 107 else \ 108 IPCOMPSTAT_INC(ipcomps_##name); \ 109 } while (0) 110 111 #ifdef INET 112 static void ipsec4_common_ctlinput(int, struct sockaddr *, void *, int); 113 #endif 114 115 /* 116 * ipsec_common_input gets called when an IPsec-protected packet 117 * is received by IPv4 or IPv6. Its job is to find the right SA 118 * and call the appropriate transform. The transform callback 119 * takes care of further processing (like ingress filtering). 120 */ 121 static int 122 ipsec_common_input(struct mbuf *m, int skip, int protoff, int af, int sproto) 123 { 124 union sockaddr_union dst_address; 125 struct secasvar *sav; 126 u_int32_t spi; 127 int error; 128 #ifdef INET 129 #ifdef IPSEC_NAT_T 130 struct m_tag *tag; 131 #endif 132 #endif 133 134 IPSEC_ISTAT(sproto, input); 135 136 IPSEC_ASSERT(m != NULL, ("null packet")); 137 138 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH || 139 sproto == IPPROTO_IPCOMP, 140 ("unexpected security protocol %u", sproto)); 141 142 if ((sproto == IPPROTO_ESP && !V_esp_enable) || 143 (sproto == IPPROTO_AH && !V_ah_enable) || 144 (sproto == IPPROTO_IPCOMP && !V_ipcomp_enable)) { 145 m_freem(m); 146 IPSEC_ISTAT(sproto, pdrops); 147 return EOPNOTSUPP; 148 } 149 150 if (m->m_pkthdr.len - skip < 2 * sizeof (u_int32_t)) { 151 m_freem(m); 152 IPSEC_ISTAT(sproto, hdrops); 153 DPRINTF(("%s: packet too small\n", __func__)); 154 return EINVAL; 155 } 156 157 /* Retrieve the SPI from the relevant IPsec header */ 158 if (sproto == IPPROTO_ESP) 159 m_copydata(m, skip, sizeof(u_int32_t), (caddr_t) &spi); 160 else if (sproto == IPPROTO_AH) 161 m_copydata(m, skip + sizeof(u_int32_t), sizeof(u_int32_t), 162 (caddr_t) &spi); 163 else if (sproto == IPPROTO_IPCOMP) { 164 u_int16_t cpi; 165 m_copydata(m, skip + sizeof(u_int16_t), sizeof(u_int16_t), 166 (caddr_t) &cpi); 167 spi = ntohl(htons(cpi)); 168 } 169 170 /* 171 * Find the SA and (indirectly) call the appropriate 172 * kernel crypto routine. The resulting mbuf chain is a valid 173 * IP packet ready to go through input processing. 174 */ 175 bzero(&dst_address, sizeof (dst_address)); 176 dst_address.sa.sa_family = af; 177 switch (af) { 178 #ifdef INET 179 case AF_INET: 180 dst_address.sin.sin_len = sizeof(struct sockaddr_in); 181 m_copydata(m, offsetof(struct ip, ip_dst), 182 sizeof(struct in_addr), 183 (caddr_t) &dst_address.sin.sin_addr); 184 #ifdef IPSEC_NAT_T 185 /* Find the source port for NAT-T; see udp*_espdecap. */ 186 tag = m_tag_find(m, PACKET_TAG_IPSEC_NAT_T_PORTS, NULL); 187 if (tag != NULL) 188 dst_address.sin.sin_port = ((u_int16_t *)(tag + 1))[1]; 189 #endif /* IPSEC_NAT_T */ 190 break; 191 #endif /* INET */ 192 #ifdef INET6 193 case AF_INET6: 194 dst_address.sin6.sin6_len = sizeof(struct sockaddr_in6); 195 m_copydata(m, offsetof(struct ip6_hdr, ip6_dst), 196 sizeof(struct in6_addr), 197 (caddr_t) &dst_address.sin6.sin6_addr); 198 break; 199 #endif /* INET6 */ 200 default: 201 DPRINTF(("%s: unsupported protocol family %u\n", __func__, af)); 202 m_freem(m); 203 IPSEC_ISTAT(sproto, nopf); 204 return EPFNOSUPPORT; 205 } 206 207 /* NB: only pass dst since key_allocsa follows RFC2401 */ 208 sav = KEY_ALLOCSA(&dst_address, sproto, spi); 209 if (sav == NULL) { 210 DPRINTF(("%s: no key association found for SA %s/%08lx/%u\n", 211 __func__, ipsec_address(&dst_address), 212 (u_long) ntohl(spi), sproto)); 213 IPSEC_ISTAT(sproto, notdb); 214 m_freem(m); 215 return ENOENT; 216 } 217 218 if (sav->tdb_xform == NULL) { 219 DPRINTF(("%s: attempted to use uninitialized SA %s/%08lx/%u\n", 220 __func__, ipsec_address(&dst_address), 221 (u_long) ntohl(spi), sproto)); 222 IPSEC_ISTAT(sproto, noxform); 223 KEY_FREESAV(&sav); 224 m_freem(m); 225 return ENXIO; 226 } 227 228 /* 229 * Call appropriate transform and return -- callback takes care of 230 * everything else. 231 */ 232 error = (*sav->tdb_xform->xf_input)(m, sav, skip, protoff); 233 KEY_FREESAV(&sav); 234 return error; 235 } 236 237 #ifdef INET 238 /* 239 * Common input handler for IPv4 AH, ESP, and IPCOMP. 240 */ 241 int 242 ipsec4_common_input(struct mbuf *m, ...) 243 { 244 va_list ap; 245 int off, nxt; 246 247 va_start(ap, m); 248 off = va_arg(ap, int); 249 nxt = va_arg(ap, int); 250 va_end(ap); 251 252 return ipsec_common_input(m, off, offsetof(struct ip, ip_p), 253 AF_INET, nxt); 254 } 255 256 void 257 ah4_input(struct mbuf *m, int off) 258 { 259 ipsec4_common_input(m, off, IPPROTO_AH); 260 } 261 void 262 ah4_ctlinput(int cmd, struct sockaddr *sa, void *v) 263 { 264 if (sa->sa_family == AF_INET && 265 sa->sa_len == sizeof(struct sockaddr_in)) 266 ipsec4_common_ctlinput(cmd, sa, v, IPPROTO_AH); 267 } 268 269 void 270 esp4_input(struct mbuf *m, int off) 271 { 272 ipsec4_common_input(m, off, IPPROTO_ESP); 273 } 274 void 275 esp4_ctlinput(int cmd, struct sockaddr *sa, void *v) 276 { 277 if (sa->sa_family == AF_INET && 278 sa->sa_len == sizeof(struct sockaddr_in)) 279 ipsec4_common_ctlinput(cmd, sa, v, IPPROTO_ESP); 280 } 281 282 void 283 ipcomp4_input(struct mbuf *m, int off) 284 { 285 ipsec4_common_input(m, off, IPPROTO_IPCOMP); 286 } 287 288 /* 289 * IPsec input callback for INET protocols. 290 * This routine is called as the transform callback. 291 * Takes care of filtering and other sanity checks on 292 * the processed packet. 293 */ 294 int 295 ipsec4_common_input_cb(struct mbuf *m, struct secasvar *sav, 296 int skip, int protoff, struct m_tag *mt) 297 { 298 int prot, af, sproto; 299 struct ip *ip; 300 struct m_tag *mtag; 301 struct tdb_ident *tdbi; 302 struct secasindex *saidx; 303 int error; 304 #ifdef INET6 305 #ifdef notyet 306 char ip6buf[INET6_ADDRSTRLEN]; 307 #endif 308 #endif 309 310 IPSEC_ASSERT(m != NULL, ("null mbuf")); 311 IPSEC_ASSERT(sav != NULL, ("null SA")); 312 IPSEC_ASSERT(sav->sah != NULL, ("null SAH")); 313 saidx = &sav->sah->saidx; 314 af = saidx->dst.sa.sa_family; 315 IPSEC_ASSERT(af == AF_INET, ("unexpected af %u", af)); 316 sproto = saidx->proto; 317 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH || 318 sproto == IPPROTO_IPCOMP, 319 ("unexpected security protocol %u", sproto)); 320 321 /* Sanity check */ 322 if (m == NULL) { 323 DPRINTF(("%s: null mbuf", __func__)); 324 IPSEC_ISTAT(sproto, badkcr); 325 KEY_FREESAV(&sav); 326 return EINVAL; 327 } 328 329 if (skip != 0) { 330 /* 331 * Fix IPv4 header 332 * XXXGL: do we need this entire block? 333 */ 334 if (m->m_len < skip && (m = m_pullup(m, skip)) == NULL) { 335 DPRINTF(("%s: processing failed for SA %s/%08lx\n", 336 __func__, ipsec_address(&sav->sah->saidx.dst), 337 (u_long) ntohl(sav->spi))); 338 IPSEC_ISTAT(sproto, hdrops); 339 error = ENOBUFS; 340 goto bad; 341 } 342 343 ip = mtod(m, struct ip *); 344 ip->ip_len = htons(m->m_pkthdr.len); 345 ip->ip_sum = 0; 346 ip->ip_sum = in_cksum(m, ip->ip_hl << 2); 347 } else { 348 ip = mtod(m, struct ip *); 349 } 350 prot = ip->ip_p; 351 352 #ifdef notyet 353 /* IP-in-IP encapsulation */ 354 if (prot == IPPROTO_IPIP) { 355 struct ip ipn; 356 357 if (m->m_pkthdr.len - skip < sizeof(struct ip)) { 358 IPSEC_ISTAT(sproto, hdrops); 359 error = EINVAL; 360 goto bad; 361 } 362 /* ipn will now contain the inner IPv4 header */ 363 m_copydata(m, ip->ip_hl << 2, sizeof(struct ip), 364 (caddr_t) &ipn); 365 366 /* XXX PROXY address isn't recorded in SAH */ 367 /* 368 * Check that the inner source address is the same as 369 * the proxy address, if available. 370 */ 371 if ((saidx->proxy.sa.sa_family == AF_INET && 372 saidx->proxy.sin.sin_addr.s_addr != 373 INADDR_ANY && 374 ipn.ip_src.s_addr != 375 saidx->proxy.sin.sin_addr.s_addr) || 376 (saidx->proxy.sa.sa_family != AF_INET && 377 saidx->proxy.sa.sa_family != 0)) { 378 379 DPRINTF(("%s: inner source address %s doesn't " 380 "correspond to expected proxy source %s, " 381 "SA %s/%08lx\n", __func__, 382 inet_ntoa4(ipn.ip_src), 383 ipsp_address(saidx->proxy), 384 ipsp_address(saidx->dst), 385 (u_long) ntohl(sav->spi))); 386 387 IPSEC_ISTAT(sproto, pdrops); 388 error = EACCES; 389 goto bad; 390 } 391 } 392 #ifdef INET6 393 /* IPv6-in-IP encapsulation. */ 394 if (prot == IPPROTO_IPV6) { 395 struct ip6_hdr ip6n; 396 397 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) { 398 IPSEC_ISTAT(sproto, hdrops); 399 error = EINVAL; 400 goto bad; 401 } 402 /* ip6n will now contain the inner IPv6 header. */ 403 m_copydata(m, ip->ip_hl << 2, sizeof(struct ip6_hdr), 404 (caddr_t) &ip6n); 405 406 /* 407 * Check that the inner source address is the same as 408 * the proxy address, if available. 409 */ 410 if ((saidx->proxy.sa.sa_family == AF_INET6 && 411 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) && 412 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src, 413 &saidx->proxy.sin6.sin6_addr)) || 414 (saidx->proxy.sa.sa_family != AF_INET6 && 415 saidx->proxy.sa.sa_family != 0)) { 416 417 DPRINTF(("%s: inner source address %s doesn't " 418 "correspond to expected proxy source %s, " 419 "SA %s/%08lx\n", __func__, 420 ip6_sprintf(ip6buf, &ip6n.ip6_src), 421 ipsec_address(&saidx->proxy), 422 ipsec_address(&saidx->dst), 423 (u_long) ntohl(sav->spi))); 424 425 IPSEC_ISTAT(sproto, pdrops); 426 error = EACCES; 427 goto bad; 428 } 429 } 430 #endif /* INET6 */ 431 #endif /*XXX*/ 432 433 /* 434 * Record what we've done to the packet (under what SA it was 435 * processed). If we've been passed an mtag, it means the packet 436 * was already processed by an ethernet/crypto combo card and 437 * thus has a tag attached with all the right information, but 438 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to 439 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type. 440 */ 441 if (mt == NULL && sproto != IPPROTO_IPCOMP) { 442 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE, 443 sizeof(struct tdb_ident), M_NOWAIT); 444 if (mtag == NULL) { 445 DPRINTF(("%s: failed to get tag\n", __func__)); 446 IPSEC_ISTAT(sproto, hdrops); 447 error = ENOMEM; 448 goto bad; 449 } 450 451 tdbi = (struct tdb_ident *)(mtag + 1); 452 bcopy(&saidx->dst, &tdbi->dst, saidx->dst.sa.sa_len); 453 tdbi->proto = sproto; 454 tdbi->spi = sav->spi; 455 /* Cache those two for enc(4) in xform_ipip. */ 456 tdbi->alg_auth = sav->alg_auth; 457 tdbi->alg_enc = sav->alg_enc; 458 459 m_tag_prepend(m, mtag); 460 } else if (mt != NULL) { 461 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE; 462 /* XXX do we need to mark m_flags??? */ 463 } 464 465 key_sa_recordxfer(sav, m); /* record data transfer */ 466 467 #ifdef DEV_ENC 468 encif->if_ipackets++; 469 encif->if_ibytes += m->m_pkthdr.len; 470 471 /* 472 * Pass the mbuf to enc0 for bpf and pfil. We will filter the IPIP 473 * packet later after it has been decapsulated. 474 */ 475 ipsec_bpf(m, sav, AF_INET, ENC_IN|ENC_BEFORE); 476 477 if (prot != IPPROTO_IPIP) 478 if ((error = ipsec_filter(&m, PFIL_IN, ENC_IN|ENC_BEFORE)) != 0) 479 return (error); 480 #endif 481 482 /* 483 * Re-dispatch via software interrupt. 484 */ 485 if ((error = netisr_queue_src(NETISR_IP, (uintptr_t)sav->spi, m))) { 486 IPSEC_ISTAT(sproto, qfull); 487 DPRINTF(("%s: queue full; proto %u packet dropped\n", 488 __func__, sproto)); 489 return error; 490 } 491 return 0; 492 bad: 493 m_freem(m); 494 return error; 495 } 496 497 void 498 ipsec4_common_ctlinput(int cmd, struct sockaddr *sa, void *v, int proto) 499 { 500 /* XXX nothing just yet */ 501 } 502 #endif /* INET */ 503 504 #ifdef INET6 505 /* IPv6 AH wrapper. */ 506 int 507 ipsec6_common_input(struct mbuf **mp, int *offp, int proto) 508 { 509 int l = 0; 510 int protoff; 511 struct ip6_ext ip6e; 512 513 if (*offp < sizeof(struct ip6_hdr)) { 514 DPRINTF(("%s: bad offset %u\n", __func__, *offp)); 515 return IPPROTO_DONE; 516 } else if (*offp == sizeof(struct ip6_hdr)) { 517 protoff = offsetof(struct ip6_hdr, ip6_nxt); 518 } else { 519 /* Chase down the header chain... */ 520 protoff = sizeof(struct ip6_hdr); 521 522 do { 523 protoff += l; 524 m_copydata(*mp, protoff, sizeof(ip6e), 525 (caddr_t) &ip6e); 526 527 if (ip6e.ip6e_nxt == IPPROTO_AH) 528 l = (ip6e.ip6e_len + 2) << 2; 529 else 530 l = (ip6e.ip6e_len + 1) << 3; 531 IPSEC_ASSERT(l > 0, ("l went zero or negative")); 532 } while (protoff + l < *offp); 533 534 /* Malformed packet check */ 535 if (protoff + l != *offp) { 536 DPRINTF(("%s: bad packet header chain, protoff %u, " 537 "l %u, off %u\n", __func__, protoff, l, *offp)); 538 IPSEC_ISTAT(proto, hdrops); 539 m_freem(*mp); 540 *mp = NULL; 541 return IPPROTO_DONE; 542 } 543 protoff += offsetof(struct ip6_ext, ip6e_nxt); 544 } 545 (void) ipsec_common_input(*mp, *offp, protoff, AF_INET6, proto); 546 return IPPROTO_DONE; 547 } 548 549 /* 550 * IPsec input callback, called by the transform callback. Takes care of 551 * filtering and other sanity checks on the processed packet. 552 */ 553 int 554 ipsec6_common_input_cb(struct mbuf *m, struct secasvar *sav, int skip, int protoff, 555 struct m_tag *mt) 556 { 557 int prot, af, sproto; 558 struct ip6_hdr *ip6; 559 struct m_tag *mtag; 560 struct tdb_ident *tdbi; 561 struct secasindex *saidx; 562 int nxt; 563 u_int8_t nxt8; 564 int error, nest; 565 #ifdef notyet 566 char ip6buf[INET6_ADDRSTRLEN]; 567 #endif 568 569 IPSEC_ASSERT(m != NULL, ("null mbuf")); 570 IPSEC_ASSERT(sav != NULL, ("null SA")); 571 IPSEC_ASSERT(sav->sah != NULL, ("null SAH")); 572 saidx = &sav->sah->saidx; 573 af = saidx->dst.sa.sa_family; 574 IPSEC_ASSERT(af == AF_INET6, ("unexpected af %u", af)); 575 sproto = saidx->proto; 576 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH || 577 sproto == IPPROTO_IPCOMP, 578 ("unexpected security protocol %u", sproto)); 579 580 /* Sanity check */ 581 if (m == NULL) { 582 DPRINTF(("%s: null mbuf", __func__)); 583 IPSEC_ISTAT(sproto, badkcr); 584 error = EINVAL; 585 goto bad; 586 } 587 588 /* Fix IPv6 header */ 589 if (m->m_len < sizeof(struct ip6_hdr) && 590 (m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 591 592 DPRINTF(("%s: processing failed for SA %s/%08lx\n", 593 __func__, ipsec_address(&sav->sah->saidx.dst), 594 (u_long) ntohl(sav->spi))); 595 596 IPSEC_ISTAT(sproto, hdrops); 597 error = EACCES; 598 goto bad; 599 } 600 601 ip6 = mtod(m, struct ip6_hdr *); 602 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 603 604 /* Save protocol */ 605 m_copydata(m, protoff, 1, (unsigned char *) &prot); 606 607 #ifdef notyet 608 #ifdef INET 609 /* IP-in-IP encapsulation */ 610 if (prot == IPPROTO_IPIP) { 611 struct ip ipn; 612 613 if (m->m_pkthdr.len - skip < sizeof(struct ip)) { 614 IPSEC_ISTAT(sproto, hdrops); 615 error = EINVAL; 616 goto bad; 617 } 618 /* ipn will now contain the inner IPv4 header */ 619 m_copydata(m, skip, sizeof(struct ip), (caddr_t) &ipn); 620 621 /* 622 * Check that the inner source address is the same as 623 * the proxy address, if available. 624 */ 625 if ((saidx->proxy.sa.sa_family == AF_INET && 626 saidx->proxy.sin.sin_addr.s_addr != INADDR_ANY && 627 ipn.ip_src.s_addr != saidx->proxy.sin.sin_addr.s_addr) || 628 (saidx->proxy.sa.sa_family != AF_INET && 629 saidx->proxy.sa.sa_family != 0)) { 630 631 DPRINTF(("%s: inner source address %s doesn't " 632 "correspond to expected proxy source %s, " 633 "SA %s/%08lx\n", __func__, 634 inet_ntoa4(ipn.ip_src), 635 ipsec_address(&saidx->proxy), 636 ipsec_address(&saidx->dst), 637 (u_long) ntohl(sav->spi))); 638 639 IPSEC_ISTAT(sproto, pdrops); 640 error = EACCES; 641 goto bad; 642 } 643 } 644 #endif /* INET */ 645 646 /* IPv6-in-IP encapsulation */ 647 if (prot == IPPROTO_IPV6) { 648 struct ip6_hdr ip6n; 649 650 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) { 651 IPSEC_ISTAT(sproto, hdrops); 652 error = EINVAL; 653 goto bad; 654 } 655 /* ip6n will now contain the inner IPv6 header. */ 656 m_copydata(m, skip, sizeof(struct ip6_hdr), 657 (caddr_t) &ip6n); 658 659 /* 660 * Check that the inner source address is the same as 661 * the proxy address, if available. 662 */ 663 if ((saidx->proxy.sa.sa_family == AF_INET6 && 664 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) && 665 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src, 666 &saidx->proxy.sin6.sin6_addr)) || 667 (saidx->proxy.sa.sa_family != AF_INET6 && 668 saidx->proxy.sa.sa_family != 0)) { 669 670 DPRINTF(("%s: inner source address %s doesn't " 671 "correspond to expected proxy source %s, " 672 "SA %s/%08lx\n", __func__, 673 ip6_sprintf(ip6buf, &ip6n.ip6_src), 674 ipsec_address(&saidx->proxy), 675 ipsec_address(&saidx->dst), 676 (u_long) ntohl(sav->spi))); 677 678 IPSEC_ISTAT(sproto, pdrops); 679 error = EACCES; 680 goto bad; 681 } 682 } 683 #endif /*XXX*/ 684 685 /* 686 * Record what we've done to the packet (under what SA it was 687 * processed). If we've been passed an mtag, it means the packet 688 * was already processed by an ethernet/crypto combo card and 689 * thus has a tag attached with all the right information, but 690 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to 691 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type. 692 */ 693 if (mt == NULL && sproto != IPPROTO_IPCOMP) { 694 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE, 695 sizeof(struct tdb_ident), M_NOWAIT); 696 if (mtag == NULL) { 697 DPRINTF(("%s: failed to get tag\n", __func__)); 698 IPSEC_ISTAT(sproto, hdrops); 699 error = ENOMEM; 700 goto bad; 701 } 702 703 tdbi = (struct tdb_ident *)(mtag + 1); 704 bcopy(&saidx->dst, &tdbi->dst, sizeof(union sockaddr_union)); 705 tdbi->proto = sproto; 706 tdbi->spi = sav->spi; 707 /* Cache those two for enc(4) in xform_ipip. */ 708 tdbi->alg_auth = sav->alg_auth; 709 tdbi->alg_enc = sav->alg_enc; 710 711 m_tag_prepend(m, mtag); 712 } else { 713 if (mt != NULL) 714 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE; 715 /* XXX do we need to mark m_flags??? */ 716 } 717 718 key_sa_recordxfer(sav, m); 719 720 #ifdef DEV_ENC 721 encif->if_ipackets++; 722 encif->if_ibytes += m->m_pkthdr.len; 723 724 /* 725 * Pass the mbuf to enc0 for bpf and pfil. We will filter the IPIP 726 * packet later after it has been decapsulated. 727 */ 728 ipsec_bpf(m, sav, AF_INET6, ENC_IN|ENC_BEFORE); 729 730 /* XXX-BZ does not make sense. */ 731 if (prot != IPPROTO_IPIP) 732 if ((error = ipsec_filter(&m, PFIL_IN, ENC_IN|ENC_BEFORE)) != 0) 733 return (error); 734 #endif 735 736 /* Retrieve new protocol */ 737 m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &nxt8); 738 739 /* 740 * See the end of ip6_input for this logic. 741 * IPPROTO_IPV[46] case will be processed just like other ones 742 */ 743 nest = 0; 744 nxt = nxt8; 745 while (nxt != IPPROTO_DONE) { 746 if (V_ip6_hdrnestlimit && (++nest > V_ip6_hdrnestlimit)) { 747 IP6STAT_INC(ip6s_toomanyhdr); 748 error = EINVAL; 749 goto bad; 750 } 751 752 /* 753 * Protection against faulty packet - there should be 754 * more sanity checks in header chain processing. 755 */ 756 if (m->m_pkthdr.len < skip) { 757 IP6STAT_INC(ip6s_tooshort); 758 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 759 error = EINVAL; 760 goto bad; 761 } 762 /* 763 * Enforce IPsec policy checking if we are seeing last header. 764 * note that we do not visit this with protocols with pcb layer 765 * code - like udp/tcp/raw ip. 766 */ 767 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 768 ipsec6_in_reject(m, NULL)) { 769 error = EINVAL; 770 goto bad; 771 } 772 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &skip, nxt); 773 } 774 return 0; 775 bad: 776 if (m) 777 m_freem(m); 778 return error; 779 } 780 781 void 782 esp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 783 { 784 struct ip6ctlparam *ip6cp = NULL; 785 struct mbuf *m = NULL; 786 struct ip6_hdr *ip6; 787 int off; 788 789 if (sa->sa_family != AF_INET6 || 790 sa->sa_len != sizeof(struct sockaddr_in6)) 791 return; 792 if ((unsigned)cmd >= PRC_NCMDS) 793 return; 794 795 /* if the parameter is from icmp6, decode it. */ 796 if (d != NULL) { 797 ip6cp = (struct ip6ctlparam *)d; 798 m = ip6cp->ip6c_m; 799 ip6 = ip6cp->ip6c_ip6; 800 off = ip6cp->ip6c_off; 801 } else { 802 m = NULL; 803 ip6 = NULL; 804 off = 0; /* calm gcc */ 805 } 806 807 if (ip6 != NULL) { 808 809 struct ip6ctlparam ip6cp1; 810 811 /* 812 * Notify the error to all possible sockets via pfctlinput2. 813 * Since the upper layer information (such as protocol type, 814 * source and destination ports) is embedded in the encrypted 815 * data and might have been cut, we can't directly call 816 * an upper layer ctlinput function. However, the pcbnotify 817 * function will consider source and destination addresses 818 * as well as the flow info value, and may be able to find 819 * some PCB that should be notified. 820 * Although pfctlinput2 will call esp6_ctlinput(), there is 821 * no possibility of an infinite loop of function calls, 822 * because we don't pass the inner IPv6 header. 823 */ 824 bzero(&ip6cp1, sizeof(ip6cp1)); 825 ip6cp1.ip6c_src = ip6cp->ip6c_src; 826 pfctlinput2(cmd, sa, (void *)&ip6cp1); 827 828 /* 829 * Then go to special cases that need ESP header information. 830 * XXX: We assume that when ip6 is non NULL, 831 * M and OFF are valid. 832 */ 833 834 if (cmd == PRC_MSGSIZE) { 835 struct secasvar *sav; 836 u_int32_t spi; 837 int valid; 838 839 /* check header length before using m_copydata */ 840 if (m->m_pkthdr.len < off + sizeof (struct esp)) 841 return; 842 m_copydata(m, off + offsetof(struct esp, esp_spi), 843 sizeof(u_int32_t), (caddr_t) &spi); 844 /* 845 * Check to see if we have a valid SA corresponding to 846 * the address in the ICMP message payload. 847 */ 848 sav = KEY_ALLOCSA((union sockaddr_union *)sa, 849 IPPROTO_ESP, spi); 850 valid = (sav != NULL); 851 if (sav) 852 KEY_FREESAV(&sav); 853 854 /* XXX Further validation? */ 855 856 /* 857 * Depending on whether the SA is "valid" and 858 * routing table size (mtudisc_{hi,lo}wat), we will: 859 * - recalcurate the new MTU and create the 860 * corresponding routing entry, or 861 * - ignore the MTU change notification. 862 */ 863 icmp6_mtudisc_update(ip6cp, valid); 864 } 865 } else { 866 /* we normally notify any pcb here */ 867 } 868 } 869 #endif /* INET6 */
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