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_SPLASSERT_SOFTNET(__func__); 292 293 IPSEC_ASSERT(m != NULL, ("null mbuf")); 294 IPSEC_ASSERT(sav != NULL, ("null SA")); 295 IPSEC_ASSERT(sav->sah != NULL, ("null SAH")); 296 saidx = &sav->sah->saidx; 297 af = saidx->dst.sa.sa_family; 298 IPSEC_ASSERT(af == AF_INET, ("unexpected af %u", af)); 299 sproto = saidx->proto; 300 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH || 301 sproto == IPPROTO_IPCOMP, 302 ("unexpected security protocol %u", sproto)); 303 304 /* Sanity check */ 305 if (m == NULL) { 306 DPRINTF(("%s: null mbuf", __func__)); 307 IPSEC_ISTAT(sproto, espstat.esps_badkcr, ahstat.ahs_badkcr, 308 ipcompstat.ipcomps_badkcr); 309 KEY_FREESAV(&sav); 310 return EINVAL; 311 } 312 313 if (skip != 0) { 314 /* Fix IPv4 header */ 315 if (m->m_len < skip && (m = m_pullup(m, skip)) == NULL) { 316 DPRINTF(("%s: processing failed for SA %s/%08lx\n", 317 __func__, ipsec_address(&sav->sah->saidx.dst), 318 (u_long) ntohl(sav->spi))); 319 IPSEC_ISTAT(sproto, espstat.esps_hdrops, ahstat.ahs_hdrops, 320 ipcompstat.ipcomps_hdrops); 321 error = ENOBUFS; 322 goto bad; 323 } 324 325 ip = mtod(m, struct ip *); 326 ip->ip_len = htons(m->m_pkthdr.len); 327 ip->ip_off = htons(ip->ip_off); 328 ip->ip_sum = 0; 329 ip->ip_sum = in_cksum(m, ip->ip_hl << 2); 330 } else { 331 ip = mtod(m, struct ip *); 332 } 333 prot = ip->ip_p; 334 335 #ifdef notyet 336 /* IP-in-IP encapsulation */ 337 if (prot == IPPROTO_IPIP) { 338 struct ip ipn; 339 340 if (m->m_pkthdr.len - skip < sizeof(struct ip)) { 341 IPSEC_ISTAT(sproto, espstat.esps_hdrops, 342 ahstat.ahs_hdrops, 343 ipcompstat.ipcomps_hdrops); 344 error = EINVAL; 345 goto bad; 346 } 347 /* ipn will now contain the inner IPv4 header */ 348 m_copydata(m, ip->ip_hl << 2, sizeof(struct ip), 349 (caddr_t) &ipn); 350 351 /* XXX PROXY address isn't recorded in SAH */ 352 /* 353 * Check that the inner source address is the same as 354 * the proxy address, if available. 355 */ 356 if ((saidx->proxy.sa.sa_family == AF_INET && 357 saidx->proxy.sin.sin_addr.s_addr != 358 INADDR_ANY && 359 ipn.ip_src.s_addr != 360 saidx->proxy.sin.sin_addr.s_addr) || 361 (saidx->proxy.sa.sa_family != AF_INET && 362 saidx->proxy.sa.sa_family != 0)) { 363 364 DPRINTF(("%s: inner source address %s doesn't " 365 "correspond to expected proxy source %s, " 366 "SA %s/%08lx\n", __func__, 367 inet_ntoa4(ipn.ip_src), 368 ipsp_address(saidx->proxy), 369 ipsp_address(saidx->dst), 370 (u_long) ntohl(sav->spi))); 371 372 IPSEC_ISTAT(sproto, espstat.esps_pdrops, 373 ahstat.ahs_pdrops, 374 ipcompstat.ipcomps_pdrops); 375 error = EACCES; 376 goto bad; 377 } 378 } 379 #ifdef INET6 380 /* IPv6-in-IP encapsulation. */ 381 if (prot == IPPROTO_IPV6) { 382 struct ip6_hdr ip6n; 383 384 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) { 385 IPSEC_ISTAT(sproto, espstat.esps_hdrops, 386 ahstat.ahs_hdrops, 387 ipcompstat.ipcomps_hdrops); 388 error = EINVAL; 389 goto bad; 390 } 391 /* ip6n will now contain the inner IPv6 header. */ 392 m_copydata(m, ip->ip_hl << 2, sizeof(struct ip6_hdr), 393 (caddr_t) &ip6n); 394 395 /* 396 * Check that the inner source address is the same as 397 * the proxy address, if available. 398 */ 399 if ((saidx->proxy.sa.sa_family == AF_INET6 && 400 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) && 401 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src, 402 &saidx->proxy.sin6.sin6_addr)) || 403 (saidx->proxy.sa.sa_family != AF_INET6 && 404 saidx->proxy.sa.sa_family != 0)) { 405 406 DPRINTF(("%s: inner source address %s doesn't " 407 "correspond to expected proxy source %s, " 408 "SA %s/%08lx\n", __func__, 409 ip6_sprintf(ip6buf, &ip6n.ip6_src), 410 ipsec_address(&saidx->proxy), 411 ipsec_address(&saidx->dst), 412 (u_long) ntohl(sav->spi))); 413 414 IPSEC_ISTAT(sproto, espstat.esps_pdrops, 415 ahstat.ahs_pdrops, 416 ipcompstat.ipcomps_pdrops); 417 error = EACCES; 418 goto bad; 419 } 420 } 421 #endif /* INET6 */ 422 #endif /*XXX*/ 423 424 /* 425 * Record what we've done to the packet (under what SA it was 426 * processed). If we've been passed an mtag, it means the packet 427 * was already processed by an ethernet/crypto combo card and 428 * thus has a tag attached with all the right information, but 429 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to 430 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type. 431 */ 432 if (mt == NULL && sproto != IPPROTO_IPCOMP) { 433 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE, 434 sizeof(struct tdb_ident), M_NOWAIT); 435 if (mtag == NULL) { 436 DPRINTF(("%s: failed to get tag\n", __func__)); 437 IPSEC_ISTAT(sproto, espstat.esps_hdrops, 438 ahstat.ahs_hdrops, ipcompstat.ipcomps_hdrops); 439 error = ENOMEM; 440 goto bad; 441 } 442 443 tdbi = (struct tdb_ident *)(mtag + 1); 444 bcopy(&saidx->dst, &tdbi->dst, saidx->dst.sa.sa_len); 445 tdbi->proto = sproto; 446 tdbi->spi = sav->spi; 447 /* Cache those two for enc(4) in xform_ipip. */ 448 tdbi->alg_auth = sav->alg_auth; 449 tdbi->alg_enc = sav->alg_enc; 450 451 m_tag_prepend(m, mtag); 452 } else if (mt != NULL) { 453 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE; 454 /* XXX do we need to mark m_flags??? */ 455 } 456 457 key_sa_recordxfer(sav, m); /* record data transfer */ 458 459 #ifdef DEV_ENC 460 /* 461 * Pass the mbuf to enc0 for bpf and pfil. We will filter the IPIP 462 * packet later after it has been decapsulated. 463 */ 464 ipsec_bpf(m, sav, AF_INET, ENC_IN|ENC_BEFORE); 465 466 if (prot != IPPROTO_IPIP) 467 if ((error = ipsec_filter(&m, PFIL_IN, ENC_IN|ENC_BEFORE)) != 0) 468 return (error); 469 #endif 470 471 /* 472 * Re-dispatch via software interrupt. 473 */ 474 if ((error = netisr_queue(NETISR_IP, m))) { 475 IPSEC_ISTAT(sproto, espstat.esps_qfull, ahstat.ahs_qfull, 476 ipcompstat.ipcomps_qfull); 477 478 DPRINTF(("%s: queue full; proto %u packet dropped\n", 479 __func__, sproto)); 480 return error; 481 } 482 return 0; 483 bad: 484 m_freem(m); 485 return error; 486 } 487 488 void 489 ipsec4_common_ctlinput(int cmd, struct sockaddr *sa, void *v, int proto) 490 { 491 /* XXX nothing just yet */ 492 } 493 #endif /* INET */ 494 495 #ifdef INET6 496 /* IPv6 AH wrapper. */ 497 int 498 ipsec6_common_input(struct mbuf **mp, int *offp, int proto) 499 { 500 int l = 0; 501 int protoff; 502 struct ip6_ext ip6e; 503 504 if (*offp < sizeof(struct ip6_hdr)) { 505 DPRINTF(("%s: bad offset %u\n", __func__, *offp)); 506 return IPPROTO_DONE; 507 } else if (*offp == sizeof(struct ip6_hdr)) { 508 protoff = offsetof(struct ip6_hdr, ip6_nxt); 509 } else { 510 /* Chase down the header chain... */ 511 protoff = sizeof(struct ip6_hdr); 512 513 do { 514 protoff += l; 515 m_copydata(*mp, protoff, sizeof(ip6e), 516 (caddr_t) &ip6e); 517 518 if (ip6e.ip6e_nxt == IPPROTO_AH) 519 l = (ip6e.ip6e_len + 2) << 2; 520 else 521 l = (ip6e.ip6e_len + 1) << 3; 522 IPSEC_ASSERT(l > 0, ("l went zero or negative")); 523 } while (protoff + l < *offp); 524 525 /* Malformed packet check */ 526 if (protoff + l != *offp) { 527 DPRINTF(("%s: bad packet header chain, protoff %u, " 528 "l %u, off %u\n", __func__, protoff, l, *offp)); 529 IPSEC_ISTAT(proto, espstat.esps_hdrops, 530 ahstat.ahs_hdrops, 531 ipcompstat.ipcomps_hdrops); 532 m_freem(*mp); 533 *mp = NULL; 534 return IPPROTO_DONE; 535 } 536 protoff += offsetof(struct ip6_ext, ip6e_nxt); 537 } 538 (void) ipsec_common_input(*mp, *offp, protoff, AF_INET6, proto); 539 return IPPROTO_DONE; 540 } 541 542 /* 543 * IPsec input callback, called by the transform callback. Takes care of 544 * filtering and other sanity checks on the processed packet. 545 */ 546 int 547 ipsec6_common_input_cb(struct mbuf *m, struct secasvar *sav, int skip, int protoff, 548 struct m_tag *mt) 549 { 550 int prot, af, sproto; 551 struct ip6_hdr *ip6; 552 struct m_tag *mtag; 553 struct tdb_ident *tdbi; 554 struct secasindex *saidx; 555 int nxt; 556 u_int8_t nxt8; 557 int error, nest; 558 #ifdef notyet 559 char ip6buf[INET6_ADDRSTRLEN]; 560 #endif 561 562 IPSEC_ASSERT(m != NULL, ("null mbuf")); 563 IPSEC_ASSERT(sav != NULL, ("null SA")); 564 IPSEC_ASSERT(sav->sah != NULL, ("null SAH")); 565 saidx = &sav->sah->saidx; 566 af = saidx->dst.sa.sa_family; 567 IPSEC_ASSERT(af == AF_INET6, ("unexpected af %u", af)); 568 sproto = saidx->proto; 569 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH || 570 sproto == IPPROTO_IPCOMP, 571 ("unexpected security protocol %u", sproto)); 572 573 /* Sanity check */ 574 if (m == NULL) { 575 DPRINTF(("%s: null mbuf", __func__)); 576 IPSEC_ISTAT(sproto, espstat.esps_badkcr, ahstat.ahs_badkcr, 577 ipcompstat.ipcomps_badkcr); 578 error = EINVAL; 579 goto bad; 580 } 581 582 /* Fix IPv6 header */ 583 if (m->m_len < sizeof(struct ip6_hdr) && 584 (m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 585 586 DPRINTF(("%s: processing failed for SA %s/%08lx\n", 587 __func__, ipsec_address(&sav->sah->saidx.dst), 588 (u_long) ntohl(sav->spi))); 589 590 IPSEC_ISTAT(sproto, espstat.esps_hdrops, ahstat.ahs_hdrops, 591 ipcompstat.ipcomps_hdrops); 592 error = EACCES; 593 goto bad; 594 } 595 596 ip6 = mtod(m, struct ip6_hdr *); 597 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 598 599 /* Save protocol */ 600 m_copydata(m, protoff, 1, (unsigned char *) &prot); 601 602 #ifdef notyet 603 #ifdef INET 604 /* IP-in-IP encapsulation */ 605 if (prot == IPPROTO_IPIP) { 606 struct ip ipn; 607 608 if (m->m_pkthdr.len - skip < sizeof(struct ip)) { 609 IPSEC_ISTAT(sproto, espstat.esps_hdrops, 610 ahstat.ahs_hdrops, 611 ipcompstat.ipcomps_hdrops); 612 error = EINVAL; 613 goto bad; 614 } 615 /* ipn will now contain the inner IPv4 header */ 616 m_copydata(m, skip, sizeof(struct ip), (caddr_t) &ipn); 617 618 /* 619 * Check that the inner source address is the same as 620 * the proxy address, if available. 621 */ 622 if ((saidx->proxy.sa.sa_family == AF_INET && 623 saidx->proxy.sin.sin_addr.s_addr != INADDR_ANY && 624 ipn.ip_src.s_addr != saidx->proxy.sin.sin_addr.s_addr) || 625 (saidx->proxy.sa.sa_family != AF_INET && 626 saidx->proxy.sa.sa_family != 0)) { 627 628 DPRINTF(("%s: inner source address %s doesn't " 629 "correspond to expected proxy source %s, " 630 "SA %s/%08lx\n", __func__, 631 inet_ntoa4(ipn.ip_src), 632 ipsec_address(&saidx->proxy), 633 ipsec_address(&saidx->dst), 634 (u_long) ntohl(sav->spi))); 635 636 IPSEC_ISTATsproto, (espstat.esps_pdrops, 637 ahstat.ahs_pdrops, ipcompstat.ipcomps_pdrops); 638 error = EACCES; 639 goto bad; 640 } 641 } 642 #endif /* INET */ 643 644 /* IPv6-in-IP encapsulation */ 645 if (prot == IPPROTO_IPV6) { 646 struct ip6_hdr ip6n; 647 648 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) { 649 IPSEC_ISTAT(sproto, espstat.esps_hdrops, 650 ahstat.ahs_hdrops, 651 ipcompstat.ipcomps_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, espstat.esps_pdrops, 679 ahstat.ahs_pdrops, ipcompstat.ipcomps_pdrops); 680 error = EACCES; 681 goto bad; 682 } 683 } 684 #endif /*XXX*/ 685 686 /* 687 * Record what we've done to the packet (under what SA it was 688 * processed). If we've been passed an mtag, it means the packet 689 * was already processed by an ethernet/crypto combo card and 690 * thus has a tag attached with all the right information, but 691 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to 692 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type. 693 */ 694 if (mt == NULL && sproto != IPPROTO_IPCOMP) { 695 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE, 696 sizeof(struct tdb_ident), M_NOWAIT); 697 if (mtag == NULL) { 698 DPRINTF(("%s: failed to get tag\n", __func__)); 699 IPSEC_ISTAT(sproto, espstat.esps_hdrops, 700 ahstat.ahs_hdrops, ipcompstat.ipcomps_hdrops); 701 error = ENOMEM; 702 goto bad; 703 } 704 705 tdbi = (struct tdb_ident *)(mtag + 1); 706 bcopy(&saidx->dst, &tdbi->dst, sizeof(union sockaddr_union)); 707 tdbi->proto = sproto; 708 tdbi->spi = sav->spi; 709 /* Cache those two for enc(4) in xform_ipip. */ 710 tdbi->alg_auth = sav->alg_auth; 711 tdbi->alg_enc = sav->alg_enc; 712 713 m_tag_prepend(m, mtag); 714 } else { 715 if (mt != NULL) 716 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE; 717 /* XXX do we need to mark m_flags??? */ 718 } 719 720 key_sa_recordxfer(sav, m); 721 722 #ifdef DEV_ENC 723 /* 724 * Pass the mbuf to enc0 for bpf and pfil. We will filter the IPIP 725 * packet later after it has been decapsulated. 726 */ 727 ipsec_bpf(m, sav, AF_INET6, ENC_IN|ENC_BEFORE); 728 729 /* XXX-BZ does not make sense. */ 730 if (prot != IPPROTO_IPIP) 731 if ((error = ipsec_filter(&m, PFIL_IN, ENC_IN|ENC_BEFORE)) != 0) 732 return (error); 733 #endif 734 735 /* Retrieve new protocol */ 736 m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &nxt8); 737 738 /* 739 * See the end of ip6_input for this logic. 740 * IPPROTO_IPV[46] case will be processed just like other ones 741 */ 742 nest = 0; 743 nxt = nxt8; 744 while (nxt != IPPROTO_DONE) { 745 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 746 ip6stat.ip6s_toomanyhdr++; 747 error = EINVAL; 748 goto bad; 749 } 750 751 /* 752 * Protection against faulty packet - there should be 753 * more sanity checks in header chain processing. 754 */ 755 if (m->m_pkthdr.len < skip) { 756 ip6stat.ip6s_tooshort++; 757 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 758 error = EINVAL; 759 goto bad; 760 } 761 /* 762 * Enforce IPsec policy checking if we are seeing last header. 763 * note that we do not visit this with protocols with pcb layer 764 * code - like udp/tcp/raw ip. 765 */ 766 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 767 ipsec6_in_reject(m, NULL)) { 768 error = EINVAL; 769 goto bad; 770 } 771 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &skip, nxt); 772 } 773 return 0; 774 bad: 775 if (m) 776 m_freem(m); 777 return error; 778 } 779 780 void 781 esp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 782 { 783 struct ip6ctlparam *ip6cp = NULL; 784 struct mbuf *m = NULL; 785 struct ip6_hdr *ip6; 786 int off; 787 788 if (sa->sa_family != AF_INET6 || 789 sa->sa_len != sizeof(struct sockaddr_in6)) 790 return; 791 if ((unsigned)cmd >= PRC_NCMDS) 792 return; 793 794 /* if the parameter is from icmp6, decode it. */ 795 if (d != NULL) { 796 ip6cp = (struct ip6ctlparam *)d; 797 m = ip6cp->ip6c_m; 798 ip6 = ip6cp->ip6c_ip6; 799 off = ip6cp->ip6c_off; 800 } else { 801 m = NULL; 802 ip6 = NULL; 803 off = 0; /* calm gcc */ 804 } 805 806 if (ip6 != NULL) { 807 808 struct ip6ctlparam ip6cp1; 809 810 /* 811 * Notify the error to all possible sockets via pfctlinput2. 812 * Since the upper layer information (such as protocol type, 813 * source and destination ports) is embedded in the encrypted 814 * data and might have been cut, we can't directly call 815 * an upper layer ctlinput function. However, the pcbnotify 816 * function will consider source and destination addresses 817 * as well as the flow info value, and may be able to find 818 * some PCB that should be notified. 819 * Although pfctlinput2 will call esp6_ctlinput(), there is 820 * no possibility of an infinite loop of function calls, 821 * because we don't pass the inner IPv6 header. 822 */ 823 bzero(&ip6cp1, sizeof(ip6cp1)); 824 ip6cp1.ip6c_src = ip6cp->ip6c_src; 825 pfctlinput2(cmd, sa, (void *)&ip6cp1); 826 827 /* 828 * Then go to special cases that need ESP header information. 829 * XXX: We assume that when ip6 is non NULL, 830 * M and OFF are valid. 831 */ 832 833 if (cmd == PRC_MSGSIZE) { 834 struct secasvar *sav; 835 u_int32_t spi; 836 int valid; 837 838 /* check header length before using m_copydata */ 839 if (m->m_pkthdr.len < off + sizeof (struct esp)) 840 return; 841 m_copydata(m, off + offsetof(struct esp, esp_spi), 842 sizeof(u_int32_t), (caddr_t) &spi); 843 /* 844 * Check to see if we have a valid SA corresponding to 845 * the address in the ICMP message payload. 846 */ 847 sav = KEY_ALLOCSA((union sockaddr_union *)sa, 848 IPPROTO_ESP, spi); 849 valid = (sav != NULL); 850 if (sav) 851 KEY_FREESAV(&sav); 852 853 /* XXX Further validation? */ 854 855 /* 856 * Depending on whether the SA is "valid" and 857 * routing table size (mtudisc_{hi,lo}wat), we will: 858 * - recalcurate the new MTU and create the 859 * corresponding routing entry, or 860 * - ignore the MTU change notification. 861 */ 862 icmp6_mtudisc_update(ip6cp, valid); 863 } 864 } else { 865 /* we normally notify any pcb here */ 866 } 867 } 868 #endif /* INET6 */ 869