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sys/netipsec/ipsec_input.c
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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/netisr.h> 61 #include <net/vnet.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 #ifdef DEV_ENC 97 #include <net/if_enc.h> 98 #endif 99 100 101 #define IPSEC_ISTAT(proto, name) do { \ 102 if ((proto) == IPPROTO_ESP) \ 103 ESPSTAT_INC(esps_##name); \ 104 else if ((proto) == IPPROTO_AH) \ 105 AHSTAT_INC(ahs_##name); \ 106 else \ 107 IPCOMPSTAT_INC(ipcomps_##name); \ 108 } while (0) 109 110 #ifdef INET 111 static void ipsec4_common_ctlinput(int, struct sockaddr *, void *, int); 112 #endif 113 114 /* 115 * ipsec_common_input gets called when an IPsec-protected packet 116 * is received by IPv4 or IPv6. Its job is to find the right SA 117 * and call the appropriate transform. The transform callback 118 * takes care of further processing (like ingress filtering). 119 */ 120 static int 121 ipsec_common_input(struct mbuf *m, int skip, int protoff, int af, int sproto) 122 { 123 union sockaddr_union dst_address; 124 struct secasvar *sav; 125 u_int32_t spi; 126 int error; 127 #ifdef INET 128 #ifdef IPSEC_NAT_T 129 struct m_tag *tag; 130 #endif 131 #endif 132 133 IPSEC_ISTAT(sproto, input); 134 135 IPSEC_ASSERT(m != NULL, ("null packet")); 136 137 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH || 138 sproto == IPPROTO_IPCOMP, 139 ("unexpected security protocol %u", sproto)); 140 141 if ((sproto == IPPROTO_ESP && !V_esp_enable) || 142 (sproto == IPPROTO_AH && !V_ah_enable) || 143 (sproto == IPPROTO_IPCOMP && !V_ipcomp_enable)) { 144 m_freem(m); 145 IPSEC_ISTAT(sproto, pdrops); 146 return EOPNOTSUPP; 147 } 148 149 if (m->m_pkthdr.len - skip < 2 * sizeof (u_int32_t)) { 150 m_freem(m); 151 IPSEC_ISTAT(sproto, hdrops); 152 DPRINTF(("%s: packet too small\n", __func__)); 153 return EINVAL; 154 } 155 156 /* Retrieve the SPI from the relevant IPsec header */ 157 if (sproto == IPPROTO_ESP) 158 m_copydata(m, skip, sizeof(u_int32_t), (caddr_t) &spi); 159 else if (sproto == IPPROTO_AH) 160 m_copydata(m, skip + sizeof(u_int32_t), sizeof(u_int32_t), 161 (caddr_t) &spi); 162 else if (sproto == IPPROTO_IPCOMP) { 163 u_int16_t cpi; 164 m_copydata(m, skip + sizeof(u_int16_t), sizeof(u_int16_t), 165 (caddr_t) &cpi); 166 spi = ntohl(htons(cpi)); 167 } 168 169 /* 170 * Find the SA and (indirectly) call the appropriate 171 * kernel crypto routine. The resulting mbuf chain is a valid 172 * IP packet ready to go through input processing. 173 */ 174 bzero(&dst_address, sizeof (dst_address)); 175 dst_address.sa.sa_family = af; 176 switch (af) { 177 #ifdef INET 178 case AF_INET: 179 dst_address.sin.sin_len = sizeof(struct sockaddr_in); 180 m_copydata(m, offsetof(struct ip, ip_dst), 181 sizeof(struct in_addr), 182 (caddr_t) &dst_address.sin.sin_addr); 183 #ifdef IPSEC_NAT_T 184 /* Find the source port for NAT-T; see udp*_espdecap. */ 185 tag = m_tag_find(m, PACKET_TAG_IPSEC_NAT_T_PORTS, NULL); 186 if (tag != NULL) 187 dst_address.sin.sin_port = ((u_int16_t *)(tag + 1))[1]; 188 #endif /* IPSEC_NAT_T */ 189 break; 190 #endif /* INET */ 191 #ifdef INET6 192 case AF_INET6: 193 dst_address.sin6.sin6_len = sizeof(struct sockaddr_in6); 194 m_copydata(m, offsetof(struct ip6_hdr, ip6_dst), 195 sizeof(struct in6_addr), 196 (caddr_t) &dst_address.sin6.sin6_addr); 197 break; 198 #endif /* INET6 */ 199 default: 200 DPRINTF(("%s: unsupported protocol family %u\n", __func__, af)); 201 m_freem(m); 202 IPSEC_ISTAT(sproto, nopf); 203 return EPFNOSUPPORT; 204 } 205 206 /* NB: only pass dst since key_allocsa follows RFC2401 */ 207 sav = KEY_ALLOCSA(&dst_address, sproto, spi); 208 if (sav == NULL) { 209 DPRINTF(("%s: no key association found for SA %s/%08lx/%u\n", 210 __func__, ipsec_address(&dst_address), 211 (u_long) ntohl(spi), sproto)); 212 IPSEC_ISTAT(sproto, notdb); 213 m_freem(m); 214 return ENOENT; 215 } 216 217 if (sav->tdb_xform == NULL) { 218 DPRINTF(("%s: attempted to use uninitialized SA %s/%08lx/%u\n", 219 __func__, ipsec_address(&dst_address), 220 (u_long) ntohl(spi), sproto)); 221 IPSEC_ISTAT(sproto, noxform); 222 KEY_FREESAV(&sav); 223 m_freem(m); 224 return ENXIO; 225 } 226 227 /* 228 * Call appropriate transform and return -- callback takes care of 229 * everything else. 230 */ 231 error = (*sav->tdb_xform->xf_input)(m, sav, skip, protoff); 232 KEY_FREESAV(&sav); 233 return error; 234 } 235 236 #ifdef INET 237 /* 238 * Common input handler for IPv4 AH, ESP, and IPCOMP. 239 */ 240 int 241 ipsec4_common_input(struct mbuf *m, ...) 242 { 243 va_list ap; 244 int off, nxt; 245 246 va_start(ap, m); 247 off = va_arg(ap, int); 248 nxt = va_arg(ap, int); 249 va_end(ap); 250 251 return ipsec_common_input(m, off, offsetof(struct ip, ip_p), 252 AF_INET, nxt); 253 } 254 255 void 256 ah4_input(struct mbuf *m, int off) 257 { 258 ipsec4_common_input(m, off, IPPROTO_AH); 259 } 260 void 261 ah4_ctlinput(int cmd, struct sockaddr *sa, void *v) 262 { 263 if (sa->sa_family == AF_INET && 264 sa->sa_len == sizeof(struct sockaddr_in)) 265 ipsec4_common_ctlinput(cmd, sa, v, IPPROTO_AH); 266 } 267 268 void 269 esp4_input(struct mbuf *m, int off) 270 { 271 ipsec4_common_input(m, off, IPPROTO_ESP); 272 } 273 void 274 esp4_ctlinput(int cmd, struct sockaddr *sa, void *v) 275 { 276 if (sa->sa_family == AF_INET && 277 sa->sa_len == sizeof(struct sockaddr_in)) 278 ipsec4_common_ctlinput(cmd, sa, v, IPPROTO_ESP); 279 } 280 281 void 282 ipcomp4_input(struct mbuf *m, int off) 283 { 284 ipsec4_common_input(m, off, IPPROTO_IPCOMP); 285 } 286 287 /* 288 * IPsec input callback for INET protocols. 289 * This routine is called as the transform callback. 290 * Takes care of filtering and other sanity checks on 291 * the processed packet. 292 */ 293 int 294 ipsec4_common_input_cb(struct mbuf *m, struct secasvar *sav, 295 int skip, int protoff, struct m_tag *mt) 296 { 297 int prot, af, sproto, isr_prot; 298 struct ip *ip; 299 struct m_tag *mtag; 300 struct tdb_ident *tdbi; 301 struct secasindex *saidx; 302 int error; 303 #ifdef INET6 304 #ifdef notyet 305 char ip6buf[INET6_ADDRSTRLEN]; 306 #endif 307 #endif 308 309 IPSEC_ASSERT(m != NULL, ("null mbuf")); 310 IPSEC_ASSERT(sav != NULL, ("null SA")); 311 IPSEC_ASSERT(sav->sah != NULL, ("null SAH")); 312 saidx = &sav->sah->saidx; 313 af = saidx->dst.sa.sa_family; 314 IPSEC_ASSERT(af == AF_INET, ("unexpected af %u", af)); 315 sproto = saidx->proto; 316 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH || 317 sproto == IPPROTO_IPCOMP, 318 ("unexpected security protocol %u", sproto)); 319 320 /* Sanity check */ 321 if (m == NULL) { 322 DPRINTF(("%s: null mbuf", __func__)); 323 IPSEC_ISTAT(sproto, badkcr); 324 KEY_FREESAV(&sav); 325 return EINVAL; 326 } 327 328 if (skip != 0) { 329 /* 330 * Fix IPv4 header 331 * XXXGL: do we need this entire block? 332 */ 333 if (m->m_len < skip && (m = m_pullup(m, skip)) == NULL) { 334 DPRINTF(("%s: processing failed for SA %s/%08lx\n", 335 __func__, ipsec_address(&sav->sah->saidx.dst), 336 (u_long) ntohl(sav->spi))); 337 IPSEC_ISTAT(sproto, hdrops); 338 error = ENOBUFS; 339 goto bad; 340 } 341 342 ip = mtod(m, struct ip *); 343 ip->ip_len = htons(m->m_pkthdr.len); 344 ip->ip_sum = 0; 345 ip->ip_sum = in_cksum(m, ip->ip_hl << 2); 346 } else { 347 ip = mtod(m, struct ip *); 348 } 349 prot = ip->ip_p; 350 351 #ifdef DEV_ENC 352 encif->if_ipackets++; 353 encif->if_ibytes += m->m_pkthdr.len; 354 355 /* Pass the mbuf to enc0 for bpf and pfil. */ 356 ipsec_bpf(m, sav, AF_INET, ENC_IN|ENC_BEFORE); 357 if ((error = ipsec_filter(&m, PFIL_IN, ENC_IN|ENC_BEFORE)) != 0) 358 return (error); 359 #endif /* DEV_ENC */ 360 361 /* IP-in-IP encapsulation */ 362 if (prot == IPPROTO_IPIP && 363 saidx->mode != IPSEC_MODE_TRANSPORT) { 364 365 if (m->m_pkthdr.len - skip < sizeof(struct ip)) { 366 IPSEC_ISTAT(sproto, hdrops); 367 error = EINVAL; 368 goto bad; 369 } 370 /* enc0: strip outer IPv4 header */ 371 m_striphdr(m, 0, ip->ip_hl << 2); 372 373 #ifdef notyet 374 /* XXX PROXY address isn't recorded in SAH */ 375 /* 376 * Check that the inner source address is the same as 377 * the proxy address, if available. 378 */ 379 if ((saidx->proxy.sa.sa_family == AF_INET && 380 saidx->proxy.sin.sin_addr.s_addr != 381 INADDR_ANY && 382 ipn.ip_src.s_addr != 383 saidx->proxy.sin.sin_addr.s_addr) || 384 (saidx->proxy.sa.sa_family != AF_INET && 385 saidx->proxy.sa.sa_family != 0)) { 386 387 DPRINTF(("%s: inner source address %s doesn't " 388 "correspond to expected proxy source %s, " 389 "SA %s/%08lx\n", __func__, 390 inet_ntoa4(ipn.ip_src), 391 ipsp_address(saidx->proxy), 392 ipsp_address(saidx->dst), 393 (u_long) ntohl(sav->spi))); 394 395 IPSEC_ISTAT(sproto, pdrops); 396 error = EACCES; 397 goto bad; 398 } 399 #endif /* notyet */ 400 } 401 #ifdef INET6 402 /* IPv6-in-IP encapsulation. */ 403 else if (prot == IPPROTO_IPV6 && 404 saidx->mode != IPSEC_MODE_TRANSPORT) { 405 406 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) { 407 IPSEC_ISTAT(sproto, hdrops); 408 error = EINVAL; 409 goto bad; 410 } 411 /* enc0: strip IPv4 header, keep IPv6 header only */ 412 m_striphdr(m, 0, ip->ip_hl << 2); 413 #ifdef notyet 414 /* 415 * Check that the inner source address is the same as 416 * the proxy address, if available. 417 */ 418 if ((saidx->proxy.sa.sa_family == AF_INET6 && 419 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) && 420 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src, 421 &saidx->proxy.sin6.sin6_addr)) || 422 (saidx->proxy.sa.sa_family != AF_INET6 && 423 saidx->proxy.sa.sa_family != 0)) { 424 425 DPRINTF(("%s: inner source address %s doesn't " 426 "correspond to expected proxy source %s, " 427 "SA %s/%08lx\n", __func__, 428 ip6_sprintf(ip6buf, &ip6n.ip6_src), 429 ipsec_address(&saidx->proxy), 430 ipsec_address(&saidx->dst), 431 (u_long) ntohl(sav->spi))); 432 433 IPSEC_ISTAT(sproto, pdrops); 434 error = EACCES; 435 goto bad; 436 } 437 #endif /* notyet */ 438 } 439 #endif /* INET6 */ 440 else if (prot != IPPROTO_IPV6 && saidx->mode == IPSEC_MODE_ANY) { 441 /* 442 * When mode is wildcard, inner protocol is IPv6 and 443 * we have no INET6 support - drop this packet a bit later. 444 * In other cases we assume transport mode and outer 445 * header was already stripped in xform_xxx_cb. 446 */ 447 prot = IPPROTO_IPIP; 448 } 449 450 /* 451 * Record what we've done to the packet (under what SA it was 452 * processed). If we've been passed an mtag, it means the packet 453 * was already processed by an ethernet/crypto combo card and 454 * thus has a tag attached with all the right information, but 455 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to 456 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type. 457 */ 458 if (mt == NULL && sproto != IPPROTO_IPCOMP) { 459 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE, 460 sizeof(struct tdb_ident), M_NOWAIT); 461 if (mtag == NULL) { 462 DPRINTF(("%s: failed to get tag\n", __func__)); 463 IPSEC_ISTAT(sproto, hdrops); 464 error = ENOMEM; 465 goto bad; 466 } 467 468 tdbi = (struct tdb_ident *)(mtag + 1); 469 bcopy(&saidx->dst, &tdbi->dst, saidx->dst.sa.sa_len); 470 tdbi->proto = sproto; 471 tdbi->spi = sav->spi; 472 /* Cache those two for enc(4) in xform_ipip. */ 473 tdbi->alg_auth = sav->alg_auth; 474 tdbi->alg_enc = sav->alg_enc; 475 476 m_tag_prepend(m, mtag); 477 } else if (mt != NULL) { 478 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE; 479 /* XXX do we need to mark m_flags??? */ 480 } 481 482 key_sa_recordxfer(sav, m); /* record data transfer */ 483 484 /* 485 * In transport mode requeue decrypted mbuf back to IPv4 protocol 486 * handler. This is necessary to correctly expose rcvif. 487 */ 488 if (saidx->mode == IPSEC_MODE_TRANSPORT) 489 prot = IPPROTO_IPIP; 490 #ifdef DEV_ENC 491 /* 492 * Pass the mbuf to enc0 for bpf and pfil. 493 */ 494 if (prot == IPPROTO_IPIP) 495 ipsec_bpf(m, sav, AF_INET, ENC_IN|ENC_AFTER); 496 #ifdef INET6 497 if (prot == IPPROTO_IPV6) 498 ipsec_bpf(m, sav, AF_INET6, ENC_IN|ENC_AFTER); 499 #endif 500 501 if ((error = ipsec_filter(&m, PFIL_IN, ENC_IN|ENC_AFTER)) != 0) 502 return (error); 503 #endif /* DEV_ENC */ 504 505 /* 506 * Re-dispatch via software interrupt. 507 */ 508 509 switch (prot) { 510 case IPPROTO_IPIP: 511 isr_prot = NETISR_IP; 512 break; 513 #ifdef INET6 514 case IPPROTO_IPV6: 515 isr_prot = NETISR_IPV6; 516 break; 517 #endif 518 default: 519 DPRINTF(("%s: cannot handle inner ip proto %d\n", 520 __func__, prot)); 521 IPSEC_ISTAT(sproto, nopf); 522 error = EPFNOSUPPORT; 523 goto bad; 524 } 525 526 error = netisr_queue_src(isr_prot, (uintptr_t)sav->spi, m); 527 if (error) { 528 IPSEC_ISTAT(sproto, qfull); 529 DPRINTF(("%s: queue full; proto %u packet dropped\n", 530 __func__, sproto)); 531 return error; 532 } 533 return 0; 534 bad: 535 m_freem(m); 536 return error; 537 } 538 539 void 540 ipsec4_common_ctlinput(int cmd, struct sockaddr *sa, void *v, int proto) 541 { 542 /* XXX nothing just yet */ 543 } 544 #endif /* INET */ 545 546 #ifdef INET6 547 /* IPv6 AH wrapper. */ 548 int 549 ipsec6_common_input(struct mbuf **mp, int *offp, int proto) 550 { 551 int l = 0; 552 int protoff; 553 struct ip6_ext ip6e; 554 555 if (*offp < sizeof(struct ip6_hdr)) { 556 DPRINTF(("%s: bad offset %u\n", __func__, *offp)); 557 return IPPROTO_DONE; 558 } else if (*offp == sizeof(struct ip6_hdr)) { 559 protoff = offsetof(struct ip6_hdr, ip6_nxt); 560 } else { 561 /* Chase down the header chain... */ 562 protoff = sizeof(struct ip6_hdr); 563 564 do { 565 protoff += l; 566 m_copydata(*mp, protoff, sizeof(ip6e), 567 (caddr_t) &ip6e); 568 569 if (ip6e.ip6e_nxt == IPPROTO_AH) 570 l = (ip6e.ip6e_len + 2) << 2; 571 else 572 l = (ip6e.ip6e_len + 1) << 3; 573 IPSEC_ASSERT(l > 0, ("l went zero or negative")); 574 } while (protoff + l < *offp); 575 576 /* Malformed packet check */ 577 if (protoff + l != *offp) { 578 DPRINTF(("%s: bad packet header chain, protoff %u, " 579 "l %u, off %u\n", __func__, protoff, l, *offp)); 580 IPSEC_ISTAT(proto, hdrops); 581 m_freem(*mp); 582 *mp = NULL; 583 return IPPROTO_DONE; 584 } 585 protoff += offsetof(struct ip6_ext, ip6e_nxt); 586 } 587 (void) ipsec_common_input(*mp, *offp, protoff, AF_INET6, proto); 588 return IPPROTO_DONE; 589 } 590 591 /* 592 * IPsec input callback, called by the transform callback. Takes care of 593 * filtering and other sanity checks on the processed packet. 594 */ 595 int 596 ipsec6_common_input_cb(struct mbuf *m, struct secasvar *sav, int skip, int protoff, 597 struct m_tag *mt) 598 { 599 int prot, af, sproto; 600 struct ip6_hdr *ip6; 601 struct m_tag *mtag; 602 struct tdb_ident *tdbi; 603 struct secasindex *saidx; 604 int nxt; 605 u_int8_t nxt8; 606 int error, nest; 607 #ifdef notyet 608 char ip6buf[INET6_ADDRSTRLEN]; 609 #endif 610 611 IPSEC_ASSERT(m != NULL, ("null mbuf")); 612 IPSEC_ASSERT(sav != NULL, ("null SA")); 613 IPSEC_ASSERT(sav->sah != NULL, ("null SAH")); 614 saidx = &sav->sah->saidx; 615 af = saidx->dst.sa.sa_family; 616 IPSEC_ASSERT(af == AF_INET6, ("unexpected af %u", af)); 617 sproto = saidx->proto; 618 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH || 619 sproto == IPPROTO_IPCOMP, 620 ("unexpected security protocol %u", sproto)); 621 622 /* Sanity check */ 623 if (m == NULL) { 624 DPRINTF(("%s: null mbuf", __func__)); 625 IPSEC_ISTAT(sproto, badkcr); 626 error = EINVAL; 627 goto bad; 628 } 629 630 /* Fix IPv6 header */ 631 if (m->m_len < sizeof(struct ip6_hdr) && 632 (m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 633 634 DPRINTF(("%s: processing failed for SA %s/%08lx\n", 635 __func__, ipsec_address(&sav->sah->saidx.dst), 636 (u_long) ntohl(sav->spi))); 637 638 IPSEC_ISTAT(sproto, hdrops); 639 error = EACCES; 640 goto bad; 641 } 642 643 ip6 = mtod(m, struct ip6_hdr *); 644 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 645 646 /* Save protocol */ 647 m_copydata(m, protoff, 1, &nxt8); 648 prot = nxt8; 649 650 #ifdef DEV_ENC 651 encif->if_ipackets++; 652 encif->if_ibytes += m->m_pkthdr.len; 653 654 /* Pass the mbuf to enc0 for bpf and pfil. */ 655 ipsec_bpf(m, sav, AF_INET6, ENC_IN|ENC_BEFORE); 656 if ((error = ipsec_filter(&m, PFIL_IN, ENC_IN|ENC_BEFORE)) != 0) 657 return (error); 658 #endif /* DEV_ENC */ 659 660 /* IPv6-in-IP encapsulation */ 661 if (prot == IPPROTO_IPV6 && 662 saidx->mode != IPSEC_MODE_TRANSPORT) { 663 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) { 664 IPSEC_ISTAT(sproto, hdrops); 665 error = EINVAL; 666 goto bad; 667 } 668 /* ip6n will now contain the inner IPv6 header. */ 669 m_striphdr(m, 0, skip); 670 skip = 0; 671 #ifdef notyet 672 /* 673 * Check that the inner source address is the same as 674 * the proxy address, if available. 675 */ 676 if ((saidx->proxy.sa.sa_family == AF_INET6 && 677 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) && 678 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src, 679 &saidx->proxy.sin6.sin6_addr)) || 680 (saidx->proxy.sa.sa_family != AF_INET6 && 681 saidx->proxy.sa.sa_family != 0)) { 682 683 DPRINTF(("%s: inner source address %s doesn't " 684 "correspond to expected proxy source %s, " 685 "SA %s/%08lx\n", __func__, 686 ip6_sprintf(ip6buf, &ip6n.ip6_src), 687 ipsec_address(&saidx->proxy), 688 ipsec_address(&saidx->dst), 689 (u_long) ntohl(sav->spi))); 690 691 IPSEC_ISTAT(sproto, pdrops); 692 error = EACCES; 693 goto bad; 694 } 695 #endif /* notyet */ 696 } 697 #ifdef INET 698 /* IP-in-IP encapsulation */ 699 else if (prot == IPPROTO_IPIP && 700 saidx->mode != IPSEC_MODE_TRANSPORT) { 701 if (m->m_pkthdr.len - skip < sizeof(struct ip)) { 702 IPSEC_ISTAT(sproto, hdrops); 703 error = EINVAL; 704 goto bad; 705 } 706 /* ipn will now contain the inner IPv4 header */ 707 m_striphdr(m, 0, skip); 708 skip = 0; 709 #ifdef notyet 710 /* 711 * Check that the inner source address is the same as 712 * the proxy address, if available. 713 */ 714 if ((saidx->proxy.sa.sa_family == AF_INET && 715 saidx->proxy.sin.sin_addr.s_addr != INADDR_ANY && 716 ipn.ip_src.s_addr != saidx->proxy.sin.sin_addr.s_addr) || 717 (saidx->proxy.sa.sa_family != AF_INET && 718 saidx->proxy.sa.sa_family != 0)) { 719 720 DPRINTF(("%s: inner source address %s doesn't " 721 "correspond to expected proxy source %s, " 722 "SA %s/%08lx\n", __func__, 723 inet_ntoa4(ipn.ip_src), 724 ipsec_address(&saidx->proxy), 725 ipsec_address(&saidx->dst), 726 (u_long) ntohl(sav->spi))); 727 728 IPSEC_ISTAT(sproto, pdrops); 729 error = EACCES; 730 goto bad; 731 } 732 #endif /* notyet */ 733 } 734 #endif /* INET */ 735 else { 736 prot = IPPROTO_IPV6; /* for correct BPF processing */ 737 } 738 739 /* 740 * Record what we've done to the packet (under what SA it was 741 * processed). If we've been passed an mtag, it means the packet 742 * was already processed by an ethernet/crypto combo card and 743 * thus has a tag attached with all the right information, but 744 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to 745 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type. 746 */ 747 if (mt == NULL && sproto != IPPROTO_IPCOMP) { 748 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE, 749 sizeof(struct tdb_ident), M_NOWAIT); 750 if (mtag == NULL) { 751 DPRINTF(("%s: failed to get tag\n", __func__)); 752 IPSEC_ISTAT(sproto, hdrops); 753 error = ENOMEM; 754 goto bad; 755 } 756 757 tdbi = (struct tdb_ident *)(mtag + 1); 758 bcopy(&saidx->dst, &tdbi->dst, sizeof(union sockaddr_union)); 759 tdbi->proto = sproto; 760 tdbi->spi = sav->spi; 761 /* Cache those two for enc(4) in xform_ipip. */ 762 tdbi->alg_auth = sav->alg_auth; 763 tdbi->alg_enc = sav->alg_enc; 764 765 m_tag_prepend(m, mtag); 766 } else { 767 if (mt != NULL) 768 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE; 769 /* XXX do we need to mark m_flags??? */ 770 } 771 772 key_sa_recordxfer(sav, m); 773 774 #ifdef DEV_ENC 775 /* 776 * Pass the mbuf to enc0 for bpf and pfil. 777 */ 778 #ifdef INET 779 if (prot == IPPROTO_IPIP) 780 ipsec_bpf(m, sav, AF_INET, ENC_IN|ENC_AFTER); 781 #endif 782 if (prot == IPPROTO_IPV6) 783 ipsec_bpf(m, sav, AF_INET6, ENC_IN|ENC_AFTER); 784 785 if ((error = ipsec_filter(&m, PFIL_IN, ENC_IN|ENC_AFTER)) != 0) 786 return (error); 787 #endif /* DEV_ENC */ 788 /* 789 * See the end of ip6_input for this logic. 790 * IPPROTO_IPV[46] case will be processed just like other ones 791 */ 792 nest = 0; 793 nxt = nxt8; 794 while (nxt != IPPROTO_DONE) { 795 if (V_ip6_hdrnestlimit && (++nest > V_ip6_hdrnestlimit)) { 796 IP6STAT_INC(ip6s_toomanyhdr); 797 error = EINVAL; 798 goto bad; 799 } 800 801 /* 802 * Protection against faulty packet - there should be 803 * more sanity checks in header chain processing. 804 */ 805 if (m->m_pkthdr.len < skip) { 806 IP6STAT_INC(ip6s_tooshort); 807 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 808 error = EINVAL; 809 goto bad; 810 } 811 /* 812 * Enforce IPsec policy checking if we are seeing last header. 813 * note that we do not visit this with protocols with pcb layer 814 * code - like udp/tcp/raw ip. 815 */ 816 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 817 ipsec6_in_reject(m, NULL)) { 818 error = EINVAL; 819 goto bad; 820 } 821 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &skip, nxt); 822 } 823 return 0; 824 bad: 825 if (m) 826 m_freem(m); 827 return error; 828 } 829 830 void 831 esp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 832 { 833 struct ip6ctlparam *ip6cp = NULL; 834 struct mbuf *m = NULL; 835 struct ip6_hdr *ip6; 836 int off; 837 838 if (sa->sa_family != AF_INET6 || 839 sa->sa_len != sizeof(struct sockaddr_in6)) 840 return; 841 if ((unsigned)cmd >= PRC_NCMDS) 842 return; 843 844 /* if the parameter is from icmp6, decode it. */ 845 if (d != NULL) { 846 ip6cp = (struct ip6ctlparam *)d; 847 m = ip6cp->ip6c_m; 848 ip6 = ip6cp->ip6c_ip6; 849 off = ip6cp->ip6c_off; 850 } else { 851 m = NULL; 852 ip6 = NULL; 853 off = 0; /* calm gcc */ 854 } 855 856 if (ip6 != NULL) { 857 858 struct ip6ctlparam ip6cp1; 859 860 /* 861 * Notify the error to all possible sockets via pfctlinput2. 862 * Since the upper layer information (such as protocol type, 863 * source and destination ports) is embedded in the encrypted 864 * data and might have been cut, we can't directly call 865 * an upper layer ctlinput function. However, the pcbnotify 866 * function will consider source and destination addresses 867 * as well as the flow info value, and may be able to find 868 * some PCB that should be notified. 869 * Although pfctlinput2 will call esp6_ctlinput(), there is 870 * no possibility of an infinite loop of function calls, 871 * because we don't pass the inner IPv6 header. 872 */ 873 bzero(&ip6cp1, sizeof(ip6cp1)); 874 ip6cp1.ip6c_src = ip6cp->ip6c_src; 875 pfctlinput2(cmd, sa, (void *)&ip6cp1); 876 877 /* 878 * Then go to special cases that need ESP header information. 879 * XXX: We assume that when ip6 is non NULL, 880 * M and OFF are valid. 881 */ 882 883 if (cmd == PRC_MSGSIZE) { 884 struct secasvar *sav; 885 u_int32_t spi; 886 int valid; 887 888 /* check header length before using m_copydata */ 889 if (m->m_pkthdr.len < off + sizeof (struct esp)) 890 return; 891 m_copydata(m, off + offsetof(struct esp, esp_spi), 892 sizeof(u_int32_t), (caddr_t) &spi); 893 /* 894 * Check to see if we have a valid SA corresponding to 895 * the address in the ICMP message payload. 896 */ 897 sav = KEY_ALLOCSA((union sockaddr_union *)sa, 898 IPPROTO_ESP, spi); 899 valid = (sav != NULL); 900 if (sav) 901 KEY_FREESAV(&sav); 902 903 /* XXX Further validation? */ 904 905 /* 906 * Depending on whether the SA is "valid" and 907 * routing table size (mtudisc_{hi,lo}wat), we will: 908 * - recalcurate the new MTU and create the 909 * corresponding routing entry, or 910 * - ignore the MTU change notification. 911 */ 912 icmp6_mtudisc_update(ip6cp, valid); 913 } 914 } else { 915 /* we normally notify any pcb here */ 916 } 917 } 918 #endif /* INET6 */
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