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 #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 63 #include <netinet/in.h> 64 #include <netinet/in_systm.h> 65 #include <netinet/ip.h> 66 #include <netinet/ip_var.h> 67 #include <netinet/in_var.h> 68 69 #include <netinet/ip6.h> 70 #ifdef INET6 71 #include <netinet6/ip6_var.h> 72 #endif 73 #include <netinet/in_pcb.h> 74 #ifdef INET6 75 #include <netinet/icmp6.h> 76 #endif 77 78 #include <netipsec/ipsec.h> 79 #ifdef INET6 80 #include <netipsec/ipsec6.h> 81 #endif 82 #include <netipsec/ah_var.h> 83 #include <netipsec/esp.h> 84 #include <netipsec/esp_var.h> 85 #include <netipsec/ipcomp_var.h> 86 87 #include <netipsec/key.h> 88 #include <netipsec/keydb.h> 89 90 #include <netipsec/xform.h> 91 #include <netinet6/ip6protosw.h> 92 93 #include <machine/in_cksum.h> 94 #include <machine/stdarg.h> 95 96 #define IPSEC_ISTAT(p,x,y,z) ((p) == IPPROTO_ESP ? (x)++ : \ 97 (p) == IPPROTO_AH ? (y)++ : (z)++) 98 99 static void ipsec4_common_ctlinput(int, struct sockaddr *, void *, int); 100 101 /* 102 * ipsec_common_input gets called when an IPsec-protected packet 103 * is received by IPv4 or IPv6. It's job is to find the right SA 104 * and call the appropriate transform. The transform callback 105 * takes care of further processing (like ingress filtering). 106 */ 107 static int 108 ipsec_common_input(struct mbuf *m, int skip, int protoff, int af, int sproto) 109 { 110 union sockaddr_union dst_address; 111 struct secasvar *sav; 112 u_int32_t spi; 113 int error; 114 115 IPSEC_ISTAT(sproto, espstat.esps_input, ahstat.ahs_input, 116 ipcompstat.ipcomps_input); 117 118 IPSEC_ASSERT(m != NULL, ("null packet")); 119 120 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH || 121 sproto == IPPROTO_IPCOMP, 122 ("unexpected security protocol %u", sproto)); 123 124 if ((sproto == IPPROTO_ESP && !esp_enable) || 125 (sproto == IPPROTO_AH && !ah_enable) || 126 (sproto == IPPROTO_IPCOMP && !ipcomp_enable)) { 127 m_freem(m); 128 IPSEC_ISTAT(sproto, espstat.esps_pdrops, ahstat.ahs_pdrops, 129 ipcompstat.ipcomps_pdrops); 130 return EOPNOTSUPP; 131 } 132 133 if (m->m_pkthdr.len - skip < 2 * sizeof (u_int32_t)) { 134 m_freem(m); 135 IPSEC_ISTAT(sproto, espstat.esps_hdrops, ahstat.ahs_hdrops, 136 ipcompstat.ipcomps_hdrops); 137 DPRINTF(("%s: packet too small\n", __func__)); 138 return EINVAL; 139 } 140 141 /* Retrieve the SPI from the relevant IPsec header */ 142 if (sproto == IPPROTO_ESP) 143 m_copydata(m, skip, sizeof(u_int32_t), (caddr_t) &spi); 144 else if (sproto == IPPROTO_AH) 145 m_copydata(m, skip + sizeof(u_int32_t), sizeof(u_int32_t), 146 (caddr_t) &spi); 147 else if (sproto == IPPROTO_IPCOMP) { 148 u_int16_t cpi; 149 m_copydata(m, skip + sizeof(u_int16_t), sizeof(u_int16_t), 150 (caddr_t) &cpi); 151 spi = ntohl(htons(cpi)); 152 } 153 154 /* 155 * Find the SA and (indirectly) call the appropriate 156 * kernel crypto routine. The resulting mbuf chain is a valid 157 * IP packet ready to go through input processing. 158 */ 159 bzero(&dst_address, sizeof (dst_address)); 160 dst_address.sa.sa_family = af; 161 switch (af) { 162 #ifdef INET 163 case AF_INET: 164 dst_address.sin.sin_len = sizeof(struct sockaddr_in); 165 m_copydata(m, offsetof(struct ip, ip_dst), 166 sizeof(struct in_addr), 167 (caddr_t) &dst_address.sin.sin_addr); 168 break; 169 #endif /* INET */ 170 #ifdef INET6 171 case AF_INET6: 172 dst_address.sin6.sin6_len = sizeof(struct sockaddr_in6); 173 m_copydata(m, offsetof(struct ip6_hdr, ip6_dst), 174 sizeof(struct in6_addr), 175 (caddr_t) &dst_address.sin6.sin6_addr); 176 break; 177 #endif /* INET6 */ 178 default: 179 DPRINTF(("%s: unsupported protocol family %u\n", __func__, af)); 180 m_freem(m); 181 IPSEC_ISTAT(sproto, espstat.esps_nopf, ahstat.ahs_nopf, 182 ipcompstat.ipcomps_nopf); 183 return EPFNOSUPPORT; 184 } 185 186 /* NB: only pass dst since key_allocsa follows RFC2401 */ 187 sav = KEY_ALLOCSA(&dst_address, sproto, spi); 188 if (sav == NULL) { 189 DPRINTF(("%s: no key association found for SA %s/%08lx/%u\n", 190 __func__, ipsec_address(&dst_address), 191 (u_long) ntohl(spi), sproto)); 192 IPSEC_ISTAT(sproto, espstat.esps_notdb, ahstat.ahs_notdb, 193 ipcompstat.ipcomps_notdb); 194 m_freem(m); 195 return ENOENT; 196 } 197 198 if (sav->tdb_xform == NULL) { 199 DPRINTF(("%s: attempted to use uninitialized SA %s/%08lx/%u\n", 200 __func__, ipsec_address(&dst_address), 201 (u_long) ntohl(spi), sproto)); 202 IPSEC_ISTAT(sproto, espstat.esps_noxform, ahstat.ahs_noxform, 203 ipcompstat.ipcomps_noxform); 204 KEY_FREESAV(&sav); 205 m_freem(m); 206 return ENXIO; 207 } 208 209 /* 210 * Call appropriate transform and return -- callback takes care of 211 * everything else. 212 */ 213 error = (*sav->tdb_xform->xf_input)(m, sav, skip, protoff); 214 KEY_FREESAV(&sav); 215 return error; 216 } 217 218 #ifdef INET 219 /* 220 * Common input handler for IPv4 AH, ESP, and IPCOMP. 221 */ 222 int 223 ipsec4_common_input(struct mbuf *m, ...) 224 { 225 va_list ap; 226 int off, nxt; 227 228 va_start(ap, m); 229 off = va_arg(ap, int); 230 nxt = va_arg(ap, int); 231 va_end(ap); 232 233 return ipsec_common_input(m, off, offsetof(struct ip, ip_p), 234 AF_INET, nxt); 235 } 236 237 void 238 ah4_input(struct mbuf *m, int off) 239 { 240 ipsec4_common_input(m, off, IPPROTO_AH); 241 } 242 void 243 ah4_ctlinput(int cmd, struct sockaddr *sa, void *v) 244 { 245 if (sa->sa_family == AF_INET && 246 sa->sa_len == sizeof(struct sockaddr_in)) 247 ipsec4_common_ctlinput(cmd, sa, v, IPPROTO_AH); 248 } 249 250 void 251 esp4_input(struct mbuf *m, int off) 252 { 253 ipsec4_common_input(m, off, IPPROTO_ESP); 254 } 255 void 256 esp4_ctlinput(int cmd, struct sockaddr *sa, void *v) 257 { 258 if (sa->sa_family == AF_INET && 259 sa->sa_len == sizeof(struct sockaddr_in)) 260 ipsec4_common_ctlinput(cmd, sa, v, IPPROTO_ESP); 261 } 262 263 void 264 ipcomp4_input(struct mbuf *m, int off) 265 { 266 ipsec4_common_input(m, off, IPPROTO_IPCOMP); 267 } 268 269 /* 270 * IPsec input callback for INET protocols. 271 * This routine is called as the transform callback. 272 * Takes care of filtering and other sanity checks on 273 * the processed packet. 274 */ 275 int 276 ipsec4_common_input_cb(struct mbuf *m, struct secasvar *sav, 277 int skip, int protoff, struct m_tag *mt) 278 { 279 int prot, af, sproto; 280 struct ip *ip; 281 struct m_tag *mtag; 282 struct tdb_ident *tdbi; 283 struct secasindex *saidx; 284 int error; 285 #ifdef INET6 286 #ifdef notyet 287 char ip6buf[INET6_ADDRSTRLEN]; 288 #endif 289 #endif 290 291 IPSEC_ASSERT(m != NULL, ("null mbuf")); 292 IPSEC_ASSERT(sav != NULL, ("null SA")); 293 IPSEC_ASSERT(sav->sah != NULL, ("null SAH")); 294 saidx = &sav->sah->saidx; 295 af = saidx->dst.sa.sa_family; 296 IPSEC_ASSERT(af == AF_INET, ("unexpected af %u", af)); 297 sproto = saidx->proto; 298 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH || 299 sproto == IPPROTO_IPCOMP, 300 ("unexpected security protocol %u", sproto)); 301 302 /* Sanity check */ 303 if (m == NULL) { 304 DPRINTF(("%s: null mbuf", __func__)); 305 IPSEC_ISTAT(sproto, espstat.esps_badkcr, ahstat.ahs_badkcr, 306 ipcompstat.ipcomps_badkcr); 307 KEY_FREESAV(&sav); 308 return EINVAL; 309 } 310 311 if (skip != 0) { 312 /* Fix IPv4 header */ 313 if (m->m_len < skip && (m = m_pullup(m, skip)) == NULL) { 314 DPRINTF(("%s: processing failed for SA %s/%08lx\n", 315 __func__, ipsec_address(&sav->sah->saidx.dst), 316 (u_long) ntohl(sav->spi))); 317 IPSEC_ISTAT(sproto, espstat.esps_hdrops, ahstat.ahs_hdrops, 318 ipcompstat.ipcomps_hdrops); 319 error = ENOBUFS; 320 goto bad; 321 } 322 323 ip = mtod(m, struct ip *); 324 ip->ip_len = htons(m->m_pkthdr.len); 325 ip->ip_off = htons(ip->ip_off); 326 ip->ip_sum = 0; 327 ip->ip_sum = in_cksum(m, ip->ip_hl << 2); 328 } else { 329 ip = mtod(m, struct ip *); 330 } 331 prot = ip->ip_p; 332 333 #ifdef notyet 334 /* IP-in-IP encapsulation */ 335 if (prot == IPPROTO_IPIP) { 336 struct ip ipn; 337 338 if (m->m_pkthdr.len - skip < sizeof(struct ip)) { 339 IPSEC_ISTAT(sproto, espstat.esps_hdrops, 340 ahstat.ahs_hdrops, 341 ipcompstat.ipcomps_hdrops); 342 error = EINVAL; 343 goto bad; 344 } 345 /* ipn will now contain the inner IPv4 header */ 346 m_copydata(m, ip->ip_hl << 2, sizeof(struct ip), 347 (caddr_t) &ipn); 348 349 /* XXX PROXY address isn't recorded in SAH */ 350 /* 351 * Check that the inner source address is the same as 352 * the proxy address, if available. 353 */ 354 if ((saidx->proxy.sa.sa_family == AF_INET && 355 saidx->proxy.sin.sin_addr.s_addr != 356 INADDR_ANY && 357 ipn.ip_src.s_addr != 358 saidx->proxy.sin.sin_addr.s_addr) || 359 (saidx->proxy.sa.sa_family != AF_INET && 360 saidx->proxy.sa.sa_family != 0)) { 361 362 DPRINTF(("%s: inner source address %s doesn't " 363 "correspond to expected proxy source %s, " 364 "SA %s/%08lx\n", __func__, 365 inet_ntoa4(ipn.ip_src), 366 ipsp_address(saidx->proxy), 367 ipsp_address(saidx->dst), 368 (u_long) ntohl(sav->spi))); 369 370 IPSEC_ISTAT(sproto, espstat.esps_pdrops, 371 ahstat.ahs_pdrops, 372 ipcompstat.ipcomps_pdrops); 373 error = EACCES; 374 goto bad; 375 } 376 } 377 #ifdef INET6 378 /* IPv6-in-IP encapsulation. */ 379 if (prot == IPPROTO_IPV6) { 380 struct ip6_hdr ip6n; 381 382 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) { 383 IPSEC_ISTAT(sproto, espstat.esps_hdrops, 384 ahstat.ahs_hdrops, 385 ipcompstat.ipcomps_hdrops); 386 error = EINVAL; 387 goto bad; 388 } 389 /* ip6n will now contain the inner IPv6 header. */ 390 m_copydata(m, ip->ip_hl << 2, sizeof(struct ip6_hdr), 391 (caddr_t) &ip6n); 392 393 /* 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(("%s: inner source address %s doesn't " 405 "correspond to expected proxy source %s, " 406 "SA %s/%08lx\n", __func__, 407 ip6_sprintf(ip6buf, &ip6n.ip6_src), 408 ipsec_address(&saidx->proxy), 409 ipsec_address(&saidx->dst), 410 (u_long) ntohl(sav->spi))); 411 412 IPSEC_ISTAT(sproto, espstat.esps_pdrops, 413 ahstat.ahs_pdrops, 414 ipcompstat.ipcomps_pdrops); 415 error = EACCES; 416 goto bad; 417 } 418 } 419 #endif /* INET6 */ 420 #endif /*XXX*/ 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(("%s: failed to get tag\n", __func__)); 435 IPSEC_ISTAT(sproto, espstat.esps_hdrops, 436 ahstat.ahs_hdrops, ipcompstat.ipcomps_hdrops); 437 error = ENOMEM; 438 goto bad; 439 } 440 441 tdbi = (struct tdb_ident *)(mtag + 1); 442 bcopy(&saidx->dst, &tdbi->dst, saidx->dst.sa.sa_len); 443 tdbi->proto = sproto; 444 tdbi->spi = sav->spi; 445 /* Cache those two for enc(4) in xform_ipip. */ 446 tdbi->alg_auth = sav->alg_auth; 447 tdbi->alg_enc = sav->alg_enc; 448 449 m_tag_prepend(m, mtag); 450 } else if (mt != NULL) { 451 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE; 452 /* XXX do we need to mark m_flags??? */ 453 } 454 455 key_sa_recordxfer(sav, m); /* record data transfer */ 456 457 #ifdef DEV_ENC 458 /* 459 * Pass the mbuf to enc0 for bpf and pfil. We will filter the IPIP 460 * packet later after it has been decapsulated. 461 */ 462 ipsec_bpf(m, sav, AF_INET, ENC_IN|ENC_BEFORE); 463 464 if (prot != IPPROTO_IPIP) 465 if ((error = ipsec_filter(&m, PFIL_IN, ENC_IN|ENC_BEFORE)) != 0) 466 return (error); 467 #endif 468 469 /* 470 * Re-dispatch via software interrupt. 471 */ 472 if ((error = netisr_queue(NETISR_IP, m))) { 473 IPSEC_ISTAT(sproto, espstat.esps_qfull, ahstat.ahs_qfull, 474 ipcompstat.ipcomps_qfull); 475 476 DPRINTF(("%s: queue full; proto %u packet dropped\n", 477 __func__, sproto)); 478 return error; 479 } 480 return 0; 481 bad: 482 m_freem(m); 483 return error; 484 } 485 486 void 487 ipsec4_common_ctlinput(int cmd, struct sockaddr *sa, void *v, int proto) 488 { 489 /* XXX nothing just yet */ 490 } 491 #endif /* INET */ 492 493 #ifdef INET6 494 /* IPv6 AH wrapper. */ 495 int 496 ipsec6_common_input(struct mbuf **mp, int *offp, int proto) 497 { 498 int l = 0; 499 int protoff; 500 struct ip6_ext ip6e; 501 502 if (*offp < sizeof(struct ip6_hdr)) { 503 DPRINTF(("%s: bad offset %u\n", __func__, *offp)); 504 return IPPROTO_DONE; 505 } else if (*offp == sizeof(struct ip6_hdr)) { 506 protoff = offsetof(struct ip6_hdr, ip6_nxt); 507 } else { 508 /* Chase down the header chain... */ 509 protoff = sizeof(struct ip6_hdr); 510 511 do { 512 protoff += l; 513 m_copydata(*mp, protoff, sizeof(ip6e), 514 (caddr_t) &ip6e); 515 516 if (ip6e.ip6e_nxt == IPPROTO_AH) 517 l = (ip6e.ip6e_len + 2) << 2; 518 else 519 l = (ip6e.ip6e_len + 1) << 3; 520 IPSEC_ASSERT(l > 0, ("l went zero or negative")); 521 } while (protoff + l < *offp); 522 523 /* Malformed packet check */ 524 if (protoff + l != *offp) { 525 DPRINTF(("%s: bad packet header chain, protoff %u, " 526 "l %u, off %u\n", __func__, protoff, l, *offp)); 527 IPSEC_ISTAT(proto, espstat.esps_hdrops, 528 ahstat.ahs_hdrops, 529 ipcompstat.ipcomps_hdrops); 530 m_freem(*mp); 531 *mp = NULL; 532 return IPPROTO_DONE; 533 } 534 protoff += offsetof(struct ip6_ext, ip6e_nxt); 535 } 536 (void) ipsec_common_input(*mp, *offp, protoff, AF_INET6, proto); 537 return IPPROTO_DONE; 538 } 539 540 /* 541 * IPsec input callback, called by the transform callback. Takes care of 542 * filtering and other sanity checks on the processed packet. 543 */ 544 int 545 ipsec6_common_input_cb(struct mbuf *m, struct secasvar *sav, int skip, int protoff, 546 struct m_tag *mt) 547 { 548 int prot, af, sproto; 549 struct ip6_hdr *ip6; 550 struct m_tag *mtag; 551 struct tdb_ident *tdbi; 552 struct secasindex *saidx; 553 int nxt; 554 u_int8_t nxt8; 555 int error, nest; 556 #ifdef notyet 557 char ip6buf[INET6_ADDRSTRLEN]; 558 #endif 559 560 IPSEC_ASSERT(m != NULL, ("null mbuf")); 561 IPSEC_ASSERT(sav != NULL, ("null SA")); 562 IPSEC_ASSERT(sav->sah != NULL, ("null SAH")); 563 saidx = &sav->sah->saidx; 564 af = saidx->dst.sa.sa_family; 565 IPSEC_ASSERT(af == AF_INET6, ("unexpected af %u", af)); 566 sproto = saidx->proto; 567 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH || 568 sproto == IPPROTO_IPCOMP, 569 ("unexpected security protocol %u", sproto)); 570 571 /* Sanity check */ 572 if (m == NULL) { 573 DPRINTF(("%s: null mbuf", __func__)); 574 IPSEC_ISTAT(sproto, espstat.esps_badkcr, ahstat.ahs_badkcr, 575 ipcompstat.ipcomps_badkcr); 576 error = EINVAL; 577 goto bad; 578 } 579 580 /* Fix IPv6 header */ 581 if (m->m_len < sizeof(struct ip6_hdr) && 582 (m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 583 584 DPRINTF(("%s: processing failed for SA %s/%08lx\n", 585 __func__, ipsec_address(&sav->sah->saidx.dst), 586 (u_long) ntohl(sav->spi))); 587 588 IPSEC_ISTAT(sproto, espstat.esps_hdrops, ahstat.ahs_hdrops, 589 ipcompstat.ipcomps_hdrops); 590 error = EACCES; 591 goto bad; 592 } 593 594 ip6 = mtod(m, struct ip6_hdr *); 595 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 596 597 /* Save protocol */ 598 m_copydata(m, protoff, 1, (unsigned char *) &prot); 599 600 #ifdef notyet 601 #ifdef INET 602 /* IP-in-IP encapsulation */ 603 if (prot == IPPROTO_IPIP) { 604 struct ip ipn; 605 606 if (m->m_pkthdr.len - skip < sizeof(struct ip)) { 607 IPSEC_ISTAT(sproto, espstat.esps_hdrops, 608 ahstat.ahs_hdrops, 609 ipcompstat.ipcomps_hdrops); 610 error = EINVAL; 611 goto bad; 612 } 613 /* ipn will now contain the inner IPv4 header */ 614 m_copydata(m, skip, sizeof(struct ip), (caddr_t) &ipn); 615 616 /* 617 * Check that the inner source address is the same as 618 * the proxy address, if available. 619 */ 620 if ((saidx->proxy.sa.sa_family == AF_INET && 621 saidx->proxy.sin.sin_addr.s_addr != INADDR_ANY && 622 ipn.ip_src.s_addr != saidx->proxy.sin.sin_addr.s_addr) || 623 (saidx->proxy.sa.sa_family != AF_INET && 624 saidx->proxy.sa.sa_family != 0)) { 625 626 DPRINTF(("%s: inner source address %s doesn't " 627 "correspond to expected proxy source %s, " 628 "SA %s/%08lx\n", __func__, 629 inet_ntoa4(ipn.ip_src), 630 ipsec_address(&saidx->proxy), 631 ipsec_address(&saidx->dst), 632 (u_long) ntohl(sav->spi))); 633 634 IPSEC_ISTATsproto, (espstat.esps_pdrops, 635 ahstat.ahs_pdrops, ipcompstat.ipcomps_pdrops); 636 error = EACCES; 637 goto bad; 638 } 639 } 640 #endif /* INET */ 641 642 /* IPv6-in-IP encapsulation */ 643 if (prot == IPPROTO_IPV6) { 644 struct ip6_hdr ip6n; 645 646 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) { 647 IPSEC_ISTAT(sproto, espstat.esps_hdrops, 648 ahstat.ahs_hdrops, 649 ipcompstat.ipcomps_hdrops); 650 error = EINVAL; 651 goto bad; 652 } 653 /* ip6n will now contain the inner IPv6 header. */ 654 m_copydata(m, skip, sizeof(struct ip6_hdr), 655 (caddr_t) &ip6n); 656 657 /* 658 * Check that the inner source address is the same as 659 * the proxy address, if available. 660 */ 661 if ((saidx->proxy.sa.sa_family == AF_INET6 && 662 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) && 663 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src, 664 &saidx->proxy.sin6.sin6_addr)) || 665 (saidx->proxy.sa.sa_family != AF_INET6 && 666 saidx->proxy.sa.sa_family != 0)) { 667 668 DPRINTF(("%s: inner source address %s doesn't " 669 "correspond to expected proxy source %s, " 670 "SA %s/%08lx\n", __func__, 671 ip6_sprintf(ip6buf, &ip6n.ip6_src), 672 ipsec_address(&saidx->proxy), 673 ipsec_address(&saidx->dst), 674 (u_long) ntohl(sav->spi))); 675 676 IPSEC_ISTAT(sproto, espstat.esps_pdrops, 677 ahstat.ahs_pdrops, ipcompstat.ipcomps_pdrops); 678 error = EACCES; 679 goto bad; 680 } 681 } 682 #endif /*XXX*/ 683 684 /* 685 * Record what we've done to the packet (under what SA it was 686 * processed). If we've been passed an mtag, it means the packet 687 * was already processed by an ethernet/crypto combo card and 688 * thus has a tag attached with all the right information, but 689 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to 690 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type. 691 */ 692 if (mt == NULL && sproto != IPPROTO_IPCOMP) { 693 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE, 694 sizeof(struct tdb_ident), M_NOWAIT); 695 if (mtag == NULL) { 696 DPRINTF(("%s: failed to get tag\n", __func__)); 697 IPSEC_ISTAT(sproto, espstat.esps_hdrops, 698 ahstat.ahs_hdrops, ipcompstat.ipcomps_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 /* 722 * Pass the mbuf to enc0 for bpf and pfil. We will filter the IPIP 723 * packet later after it has been decapsulated. 724 */ 725 ipsec_bpf(m, sav, AF_INET6, ENC_IN|ENC_BEFORE); 726 727 /* XXX-BZ does not make sense. */ 728 if (prot != IPPROTO_IPIP) 729 if ((error = ipsec_filter(&m, PFIL_IN, ENC_IN|ENC_BEFORE)) != 0) 730 return (error); 731 #endif 732 733 /* Retrieve new protocol */ 734 m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &nxt8); 735 736 /* 737 * See the end of ip6_input for this logic. 738 * IPPROTO_IPV[46] case will be processed just like other ones 739 */ 740 nest = 0; 741 nxt = nxt8; 742 while (nxt != IPPROTO_DONE) { 743 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 744 ip6stat.ip6s_toomanyhdr++; 745 error = EINVAL; 746 goto bad; 747 } 748 749 /* 750 * Protection against faulty packet - there should be 751 * more sanity checks in header chain processing. 752 */ 753 if (m->m_pkthdr.len < skip) { 754 ip6stat.ip6s_tooshort++; 755 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 756 error = EINVAL; 757 goto bad; 758 } 759 /* 760 * Enforce IPsec policy checking if we are seeing last header. 761 * note that we do not visit this with protocols with pcb layer 762 * code - like udp/tcp/raw ip. 763 */ 764 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 765 ipsec6_in_reject(m, NULL)) { 766 error = EINVAL; 767 goto bad; 768 } 769 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &skip, nxt); 770 } 771 return 0; 772 bad: 773 if (m) 774 m_freem(m); 775 return error; 776 } 777 778 void 779 esp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 780 { 781 struct ip6ctlparam *ip6cp = NULL; 782 struct mbuf *m = NULL; 783 struct ip6_hdr *ip6; 784 int off; 785 786 if (sa->sa_family != AF_INET6 || 787 sa->sa_len != sizeof(struct sockaddr_in6)) 788 return; 789 if ((unsigned)cmd >= PRC_NCMDS) 790 return; 791 792 /* if the parameter is from icmp6, decode it. */ 793 if (d != NULL) { 794 ip6cp = (struct ip6ctlparam *)d; 795 m = ip6cp->ip6c_m; 796 ip6 = ip6cp->ip6c_ip6; 797 off = ip6cp->ip6c_off; 798 } else { 799 m = NULL; 800 ip6 = NULL; 801 off = 0; /* calm gcc */ 802 } 803 804 if (ip6 != NULL) { 805 806 struct ip6ctlparam ip6cp1; 807 808 /* 809 * Notify the error to all possible sockets via pfctlinput2. 810 * Since the upper layer information (such as protocol type, 811 * source and destination ports) is embedded in the encrypted 812 * data and might have been cut, we can't directly call 813 * an upper layer ctlinput function. However, the pcbnotify 814 * function will consider source and destination addresses 815 * as well as the flow info value, and may be able to find 816 * some PCB that should be notified. 817 * Although pfctlinput2 will call esp6_ctlinput(), there is 818 * no possibility of an infinite loop of function calls, 819 * because we don't pass the inner IPv6 header. 820 */ 821 bzero(&ip6cp1, sizeof(ip6cp1)); 822 ip6cp1.ip6c_src = ip6cp->ip6c_src; 823 pfctlinput2(cmd, sa, (void *)&ip6cp1); 824 825 /* 826 * Then go to special cases that need ESP header information. 827 * XXX: We assume that when ip6 is non NULL, 828 * M and OFF are valid. 829 */ 830 831 if (cmd == PRC_MSGSIZE) { 832 struct secasvar *sav; 833 u_int32_t spi; 834 int valid; 835 836 /* check header length before using m_copydata */ 837 if (m->m_pkthdr.len < off + sizeof (struct esp)) 838 return; 839 m_copydata(m, off + offsetof(struct esp, esp_spi), 840 sizeof(u_int32_t), (caddr_t) &spi); 841 /* 842 * Check to see if we have a valid SA corresponding to 843 * the address in the ICMP message payload. 844 */ 845 sav = KEY_ALLOCSA((union sockaddr_union *)sa, 846 IPPROTO_ESP, spi); 847 valid = (sav != NULL); 848 if (sav) 849 KEY_FREESAV(&sav); 850 851 /* XXX Further validation? */ 852 853 /* 854 * Depending on whether the SA is "valid" and 855 * routing table size (mtudisc_{hi,lo}wat), we will: 856 * - recalcurate the new MTU and create the 857 * corresponding routing entry, or 858 * - ignore the MTU change notification. 859 */ 860 icmp6_mtudisc_update(ip6cp, valid); 861 } 862 } else { 863 /* we normally notify any pcb here */ 864 } 865 } 866 #endif /* INET6 */ 867