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/if_var.h> 60 #include <net/pfil.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 int 122 ipsec_common_input(struct mbuf *m, int skip, int protoff, int af, int sproto) 123 { 124 char buf[INET6_ADDRSTRLEN]; 125 union sockaddr_union dst_address; 126 struct secasvar *sav; 127 u_int32_t spi; 128 int error; 129 #ifdef INET 130 #ifdef IPSEC_NAT_T 131 struct m_tag *tag; 132 #endif 133 #endif 134 135 IPSEC_ISTAT(sproto, input); 136 137 IPSEC_ASSERT(m != NULL, ("null packet")); 138 139 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH || 140 sproto == IPPROTO_IPCOMP, 141 ("unexpected security protocol %u", sproto)); 142 143 if ((sproto == IPPROTO_ESP && !V_esp_enable) || 144 (sproto == IPPROTO_AH && !V_ah_enable) || 145 (sproto == IPPROTO_IPCOMP && !V_ipcomp_enable)) { 146 m_freem(m); 147 IPSEC_ISTAT(sproto, pdrops); 148 return EOPNOTSUPP; 149 } 150 151 if (m->m_pkthdr.len - skip < 2 * sizeof (u_int32_t)) { 152 m_freem(m); 153 IPSEC_ISTAT(sproto, hdrops); 154 DPRINTF(("%s: packet too small\n", __func__)); 155 return EINVAL; 156 } 157 158 /* Retrieve the SPI from the relevant IPsec header */ 159 if (sproto == IPPROTO_ESP) 160 m_copydata(m, skip, sizeof(u_int32_t), (caddr_t) &spi); 161 else if (sproto == IPPROTO_AH) 162 m_copydata(m, skip + sizeof(u_int32_t), sizeof(u_int32_t), 163 (caddr_t) &spi); 164 else if (sproto == IPPROTO_IPCOMP) { 165 u_int16_t cpi; 166 m_copydata(m, skip + sizeof(u_int16_t), sizeof(u_int16_t), 167 (caddr_t) &cpi); 168 spi = ntohl(htons(cpi)); 169 } 170 171 /* 172 * Find the SA and (indirectly) call the appropriate 173 * kernel crypto routine. The resulting mbuf chain is a valid 174 * IP packet ready to go through input processing. 175 */ 176 bzero(&dst_address, sizeof (dst_address)); 177 dst_address.sa.sa_family = af; 178 switch (af) { 179 #ifdef INET 180 case AF_INET: 181 dst_address.sin.sin_len = sizeof(struct sockaddr_in); 182 m_copydata(m, offsetof(struct ip, ip_dst), 183 sizeof(struct in_addr), 184 (caddr_t) &dst_address.sin.sin_addr); 185 #ifdef IPSEC_NAT_T 186 /* Find the source port for NAT-T; see udp*_espdecap. */ 187 tag = m_tag_find(m, PACKET_TAG_IPSEC_NAT_T_PORTS, NULL); 188 if (tag != NULL) 189 dst_address.sin.sin_port = ((u_int16_t *)(tag + 1))[1]; 190 #endif /* IPSEC_NAT_T */ 191 break; 192 #endif /* INET */ 193 #ifdef INET6 194 case AF_INET6: 195 dst_address.sin6.sin6_len = sizeof(struct sockaddr_in6); 196 m_copydata(m, offsetof(struct ip6_hdr, ip6_dst), 197 sizeof(struct in6_addr), 198 (caddr_t) &dst_address.sin6.sin6_addr); 199 /* We keep addresses in SADB without embedded scope id */ 200 if (IN6_IS_SCOPE_LINKLOCAL(&dst_address.sin6.sin6_addr)) { 201 /* XXX: sa6_recoverscope() */ 202 dst_address.sin6.sin6_scope_id = 203 ntohs(dst_address.sin6.sin6_addr.s6_addr16[1]); 204 dst_address.sin6.sin6_addr.s6_addr16[1] = 0; 205 } 206 break; 207 #endif /* INET6 */ 208 default: 209 DPRINTF(("%s: unsupported protocol family %u\n", __func__, af)); 210 m_freem(m); 211 IPSEC_ISTAT(sproto, nopf); 212 return EPFNOSUPPORT; 213 } 214 215 /* NB: only pass dst since key_allocsa follows RFC2401 */ 216 sav = KEY_ALLOCSA(&dst_address, sproto, spi); 217 if (sav == NULL) { 218 DPRINTF(("%s: no key association found for SA %s/%08lx/%u\n", 219 __func__, ipsec_address(&dst_address, buf, sizeof(buf)), 220 (u_long) ntohl(spi), sproto)); 221 IPSEC_ISTAT(sproto, notdb); 222 m_freem(m); 223 return ENOENT; 224 } 225 226 if (sav->tdb_xform == NULL) { 227 DPRINTF(("%s: attempted to use uninitialized SA %s/%08lx/%u\n", 228 __func__, ipsec_address(&dst_address, buf, sizeof(buf)), 229 (u_long) ntohl(spi), sproto)); 230 IPSEC_ISTAT(sproto, noxform); 231 KEY_FREESAV(&sav); 232 m_freem(m); 233 return ENXIO; 234 } 235 236 /* 237 * Call appropriate transform and return -- callback takes care of 238 * everything else. 239 */ 240 error = (*sav->tdb_xform->xf_input)(m, sav, skip, protoff); 241 KEY_FREESAV(&sav); 242 return error; 243 } 244 245 #ifdef INET 246 int 247 ah4_input(struct mbuf **mp, int *offp, int proto) 248 { 249 struct mbuf *m; 250 int off; 251 252 m = *mp; 253 off = *offp; 254 *mp = NULL; 255 256 ipsec_common_input(m, off, offsetof(struct ip, ip_p), 257 AF_INET, IPPROTO_AH); 258 return (IPPROTO_DONE); 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 int 269 esp4_input(struct mbuf **mp, int *offp, int proto) 270 { 271 struct mbuf *m; 272 int off; 273 274 m = *mp; 275 off = *offp; 276 mp = NULL; 277 278 ipsec_common_input(m, off, offsetof(struct ip, ip_p), 279 AF_INET, IPPROTO_ESP); 280 return (IPPROTO_DONE); 281 } 282 283 void 284 esp4_ctlinput(int cmd, struct sockaddr *sa, void *v) 285 { 286 if (sa->sa_family == AF_INET && 287 sa->sa_len == sizeof(struct sockaddr_in)) 288 ipsec4_common_ctlinput(cmd, sa, v, IPPROTO_ESP); 289 } 290 291 int 292 ipcomp4_input(struct mbuf **mp, int *offp, int proto) 293 { 294 struct mbuf *m; 295 int off; 296 297 m = *mp; 298 off = *offp; 299 mp = NULL; 300 301 ipsec_common_input(m, off, offsetof(struct ip, ip_p), 302 AF_INET, IPPROTO_IPCOMP); 303 return (IPPROTO_DONE); 304 } 305 306 /* 307 * IPsec input callback for INET protocols. 308 * This routine is called as the transform callback. 309 * Takes care of filtering and other sanity checks on 310 * the processed packet. 311 */ 312 int 313 ipsec4_common_input_cb(struct mbuf *m, struct secasvar *sav, int skip, 314 int protoff) 315 { 316 char buf[INET6_ADDRSTRLEN]; 317 int prot, af, sproto, isr_prot; 318 struct ip *ip; 319 struct m_tag *mtag; 320 struct tdb_ident *tdbi; 321 struct secasindex *saidx; 322 int error; 323 #ifdef INET6 324 #ifdef notyet 325 char ip6buf[INET6_ADDRSTRLEN]; 326 #endif 327 #endif 328 329 IPSEC_ASSERT(m != NULL, ("null mbuf")); 330 IPSEC_ASSERT(sav != NULL, ("null SA")); 331 IPSEC_ASSERT(sav->sah != NULL, ("null SAH")); 332 saidx = &sav->sah->saidx; 333 af = saidx->dst.sa.sa_family; 334 IPSEC_ASSERT(af == AF_INET, ("unexpected af %u", af)); 335 sproto = saidx->proto; 336 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH || 337 sproto == IPPROTO_IPCOMP, 338 ("unexpected security protocol %u", sproto)); 339 340 /* Sanity check */ 341 if (m == NULL) { 342 DPRINTF(("%s: null mbuf", __func__)); 343 IPSEC_ISTAT(sproto, badkcr); 344 KEY_FREESAV(&sav); 345 return EINVAL; 346 } 347 348 if (skip != 0) { 349 /* 350 * Fix IPv4 header 351 * XXXGL: do we need this entire block? 352 */ 353 if (m->m_len < skip && (m = m_pullup(m, skip)) == NULL) { 354 DPRINTF(("%s: processing failed for SA %s/%08lx\n", 355 __func__, ipsec_address(&sav->sah->saidx.dst, 356 buf, sizeof(buf)), (u_long) ntohl(sav->spi))); 357 IPSEC_ISTAT(sproto, hdrops); 358 error = ENOBUFS; 359 goto bad; 360 } 361 362 ip = mtod(m, struct ip *); 363 ip->ip_len = htons(m->m_pkthdr.len); 364 ip->ip_sum = 0; 365 ip->ip_sum = in_cksum(m, ip->ip_hl << 2); 366 } else { 367 ip = mtod(m, struct ip *); 368 } 369 prot = ip->ip_p; 370 371 #ifdef DEV_ENC 372 if_inc_counter(encif, IFCOUNTER_IPACKETS, 1); 373 if_inc_counter(encif, IFCOUNTER_IBYTES, m->m_pkthdr.len); 374 375 /* Pass the mbuf to enc0 for bpf and pfil. */ 376 ipsec_bpf(m, sav, AF_INET, ENC_IN|ENC_BEFORE); 377 if ((error = ipsec_filter(&m, PFIL_IN, ENC_IN|ENC_BEFORE)) != 0) 378 return (error); 379 ip = mtod(m, struct ip *); 380 #endif /* DEV_ENC */ 381 382 /* IP-in-IP encapsulation */ 383 if (prot == IPPROTO_IPIP && 384 saidx->mode != IPSEC_MODE_TRANSPORT) { 385 386 if (m->m_pkthdr.len - skip < sizeof(struct ip)) { 387 IPSEC_ISTAT(sproto, hdrops); 388 error = EINVAL; 389 goto bad; 390 } 391 /* enc0: strip outer IPv4 header */ 392 m_striphdr(m, 0, ip->ip_hl << 2); 393 394 #ifdef notyet 395 /* XXX PROXY address isn't recorded in SAH */ 396 /* 397 * Check that the inner source address is the same as 398 * the proxy address, if available. 399 */ 400 if ((saidx->proxy.sa.sa_family == AF_INET && 401 saidx->proxy.sin.sin_addr.s_addr != 402 INADDR_ANY && 403 ipn.ip_src.s_addr != 404 saidx->proxy.sin.sin_addr.s_addr) || 405 (saidx->proxy.sa.sa_family != AF_INET && 406 saidx->proxy.sa.sa_family != 0)) { 407 408 DPRINTF(("%s: inner source address %s doesn't " 409 "correspond to expected proxy source %s, " 410 "SA %s/%08lx\n", __func__, 411 inet_ntoa4(ipn.ip_src), 412 ipsp_address(saidx->proxy), 413 ipsp_address(saidx->dst), 414 (u_long) ntohl(sav->spi))); 415 416 IPSEC_ISTAT(sproto, pdrops); 417 error = EACCES; 418 goto bad; 419 } 420 #endif /* notyet */ 421 } 422 #ifdef INET6 423 /* IPv6-in-IP encapsulation. */ 424 else if (prot == IPPROTO_IPV6 && 425 saidx->mode != IPSEC_MODE_TRANSPORT) { 426 427 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) { 428 IPSEC_ISTAT(sproto, hdrops); 429 error = EINVAL; 430 goto bad; 431 } 432 /* enc0: strip IPv4 header, keep IPv6 header only */ 433 m_striphdr(m, 0, ip->ip_hl << 2); 434 #ifdef notyet 435 /* 436 * Check that the inner source address is the same as 437 * the proxy address, if available. 438 */ 439 if ((saidx->proxy.sa.sa_family == AF_INET6 && 440 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) && 441 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src, 442 &saidx->proxy.sin6.sin6_addr)) || 443 (saidx->proxy.sa.sa_family != AF_INET6 && 444 saidx->proxy.sa.sa_family != 0)) { 445 446 DPRINTF(("%s: inner source address %s doesn't " 447 "correspond to expected proxy source %s, " 448 "SA %s/%08lx\n", __func__, 449 ip6_sprintf(ip6buf, &ip6n.ip6_src), 450 ipsec_address(&saidx->proxy), 451 ipsec_address(&saidx->dst), 452 (u_long) ntohl(sav->spi))); 453 454 IPSEC_ISTAT(sproto, pdrops); 455 error = EACCES; 456 goto bad; 457 } 458 #endif /* notyet */ 459 } 460 #endif /* INET6 */ 461 else if (prot != IPPROTO_IPV6 && saidx->mode == IPSEC_MODE_ANY) { 462 /* 463 * When mode is wildcard, inner protocol is IPv6 and 464 * we have no INET6 support - drop this packet a bit later. 465 * In other cases we assume transport mode and outer 466 * header was already stripped in xform_xxx_cb. 467 */ 468 prot = IPPROTO_IPIP; 469 } 470 471 /* 472 * Record what we've done to the packet (under what SA it was 473 * processed). 474 */ 475 if (sproto != IPPROTO_IPCOMP) { 476 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE, 477 sizeof(struct tdb_ident), M_NOWAIT); 478 if (mtag == NULL) { 479 DPRINTF(("%s: failed to get tag\n", __func__)); 480 IPSEC_ISTAT(sproto, hdrops); 481 error = ENOMEM; 482 goto bad; 483 } 484 485 tdbi = (struct tdb_ident *)(mtag + 1); 486 bcopy(&saidx->dst, &tdbi->dst, saidx->dst.sa.sa_len); 487 tdbi->proto = sproto; 488 tdbi->spi = sav->spi; 489 /* Cache those two for enc(4) in xform_ipip. */ 490 tdbi->alg_auth = sav->alg_auth; 491 tdbi->alg_enc = sav->alg_enc; 492 493 m_tag_prepend(m, mtag); 494 } 495 496 key_sa_recordxfer(sav, m); /* record data transfer */ 497 498 /* 499 * In transport mode requeue decrypted mbuf back to IPv4 protocol 500 * handler. This is necessary to correctly expose rcvif. 501 */ 502 if (saidx->mode == IPSEC_MODE_TRANSPORT) 503 prot = IPPROTO_IPIP; 504 #ifdef DEV_ENC 505 /* 506 * Pass the mbuf to enc0 for bpf and pfil. 507 */ 508 if (prot == IPPROTO_IPIP) 509 ipsec_bpf(m, sav, AF_INET, ENC_IN|ENC_AFTER); 510 #ifdef INET6 511 if (prot == IPPROTO_IPV6) 512 ipsec_bpf(m, sav, AF_INET6, ENC_IN|ENC_AFTER); 513 #endif 514 515 if ((error = ipsec_filter(&m, PFIL_IN, ENC_IN|ENC_AFTER)) != 0) 516 return (error); 517 #endif /* DEV_ENC */ 518 519 /* 520 * Re-dispatch via software interrupt. 521 */ 522 523 switch (prot) { 524 case IPPROTO_IPIP: 525 isr_prot = NETISR_IP; 526 break; 527 #ifdef INET6 528 case IPPROTO_IPV6: 529 isr_prot = NETISR_IPV6; 530 break; 531 #endif 532 default: 533 DPRINTF(("%s: cannot handle inner ip proto %d\n", 534 __func__, prot)); 535 IPSEC_ISTAT(sproto, nopf); 536 error = EPFNOSUPPORT; 537 goto bad; 538 } 539 540 error = netisr_queue_src(isr_prot, (uintptr_t)sav->spi, m); 541 if (error) { 542 IPSEC_ISTAT(sproto, qfull); 543 DPRINTF(("%s: queue full; proto %u packet dropped\n", 544 __func__, sproto)); 545 return error; 546 } 547 return 0; 548 bad: 549 m_freem(m); 550 return error; 551 } 552 553 void 554 ipsec4_common_ctlinput(int cmd, struct sockaddr *sa, void *v, int proto) 555 { 556 /* XXX nothing just yet */ 557 } 558 #endif /* INET */ 559 560 #ifdef INET6 561 /* IPv6 AH wrapper. */ 562 int 563 ipsec6_common_input(struct mbuf **mp, int *offp, int proto) 564 { 565 int l = 0; 566 int protoff; 567 struct ip6_ext ip6e; 568 569 if (*offp < sizeof(struct ip6_hdr)) { 570 DPRINTF(("%s: bad offset %u\n", __func__, *offp)); 571 return IPPROTO_DONE; 572 } else if (*offp == sizeof(struct ip6_hdr)) { 573 protoff = offsetof(struct ip6_hdr, ip6_nxt); 574 } else { 575 /* Chase down the header chain... */ 576 protoff = sizeof(struct ip6_hdr); 577 578 do { 579 protoff += l; 580 m_copydata(*mp, protoff, sizeof(ip6e), 581 (caddr_t) &ip6e); 582 583 if (ip6e.ip6e_nxt == IPPROTO_AH) 584 l = (ip6e.ip6e_len + 2) << 2; 585 else 586 l = (ip6e.ip6e_len + 1) << 3; 587 IPSEC_ASSERT(l > 0, ("l went zero or negative")); 588 } while (protoff + l < *offp); 589 590 /* Malformed packet check */ 591 if (protoff + l != *offp) { 592 DPRINTF(("%s: bad packet header chain, protoff %u, " 593 "l %u, off %u\n", __func__, protoff, l, *offp)); 594 IPSEC_ISTAT(proto, hdrops); 595 m_freem(*mp); 596 *mp = NULL; 597 return IPPROTO_DONE; 598 } 599 protoff += offsetof(struct ip6_ext, ip6e_nxt); 600 } 601 (void) ipsec_common_input(*mp, *offp, protoff, AF_INET6, proto); 602 return IPPROTO_DONE; 603 } 604 605 /* 606 * IPsec input callback, called by the transform callback. Takes care of 607 * filtering and other sanity checks on the processed packet. 608 */ 609 int 610 ipsec6_common_input_cb(struct mbuf *m, struct secasvar *sav, int skip, 611 int protoff) 612 { 613 char buf[INET6_ADDRSTRLEN]; 614 int prot, af, sproto; 615 struct ip6_hdr *ip6; 616 struct m_tag *mtag; 617 struct tdb_ident *tdbi; 618 struct secasindex *saidx; 619 int nxt, isr_prot; 620 u_int8_t nxt8; 621 int error, nest; 622 #ifdef notyet 623 char ip6buf[INET6_ADDRSTRLEN]; 624 #endif 625 626 IPSEC_ASSERT(m != NULL, ("null mbuf")); 627 IPSEC_ASSERT(sav != NULL, ("null SA")); 628 IPSEC_ASSERT(sav->sah != NULL, ("null SAH")); 629 saidx = &sav->sah->saidx; 630 af = saidx->dst.sa.sa_family; 631 IPSEC_ASSERT(af == AF_INET6, ("unexpected af %u", af)); 632 sproto = saidx->proto; 633 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH || 634 sproto == IPPROTO_IPCOMP, 635 ("unexpected security protocol %u", sproto)); 636 637 /* Sanity check */ 638 if (m == NULL) { 639 DPRINTF(("%s: null mbuf", __func__)); 640 IPSEC_ISTAT(sproto, badkcr); 641 error = EINVAL; 642 goto bad; 643 } 644 645 /* Fix IPv6 header */ 646 if (m->m_len < sizeof(struct ip6_hdr) && 647 (m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 648 649 DPRINTF(("%s: processing failed for SA %s/%08lx\n", 650 __func__, ipsec_address(&sav->sah->saidx.dst, buf, 651 sizeof(buf)), (u_long) ntohl(sav->spi))); 652 653 IPSEC_ISTAT(sproto, hdrops); 654 error = EACCES; 655 goto bad; 656 } 657 658 ip6 = mtod(m, struct ip6_hdr *); 659 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 660 661 /* Save protocol */ 662 m_copydata(m, protoff, 1, &nxt8); 663 prot = nxt8; 664 665 #ifdef DEV_ENC 666 if_inc_counter(encif, IFCOUNTER_IPACKETS, 1); 667 if_inc_counter(encif, IFCOUNTER_IBYTES, m->m_pkthdr.len); 668 669 /* Pass the mbuf to enc0 for bpf and pfil. */ 670 ipsec_bpf(m, sav, AF_INET6, ENC_IN|ENC_BEFORE); 671 if ((error = ipsec_filter(&m, PFIL_IN, ENC_IN|ENC_BEFORE)) != 0) 672 return (error); 673 #endif /* DEV_ENC */ 674 675 /* IPv6-in-IP encapsulation */ 676 if (prot == IPPROTO_IPV6 && 677 saidx->mode != IPSEC_MODE_TRANSPORT) { 678 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) { 679 IPSEC_ISTAT(sproto, hdrops); 680 error = EINVAL; 681 goto bad; 682 } 683 /* ip6n will now contain the inner IPv6 header. */ 684 m_striphdr(m, 0, skip); 685 skip = 0; 686 #ifdef notyet 687 /* 688 * Check that the inner source address is the same as 689 * the proxy address, if available. 690 */ 691 if ((saidx->proxy.sa.sa_family == AF_INET6 && 692 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) && 693 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src, 694 &saidx->proxy.sin6.sin6_addr)) || 695 (saidx->proxy.sa.sa_family != AF_INET6 && 696 saidx->proxy.sa.sa_family != 0)) { 697 698 DPRINTF(("%s: inner source address %s doesn't " 699 "correspond to expected proxy source %s, " 700 "SA %s/%08lx\n", __func__, 701 ip6_sprintf(ip6buf, &ip6n.ip6_src), 702 ipsec_address(&saidx->proxy), 703 ipsec_address(&saidx->dst), 704 (u_long) ntohl(sav->spi))); 705 706 IPSEC_ISTAT(sproto, pdrops); 707 error = EACCES; 708 goto bad; 709 } 710 #endif /* notyet */ 711 } 712 #ifdef INET 713 /* IP-in-IP encapsulation */ 714 else if (prot == IPPROTO_IPIP && 715 saidx->mode != IPSEC_MODE_TRANSPORT) { 716 if (m->m_pkthdr.len - skip < sizeof(struct ip)) { 717 IPSEC_ISTAT(sproto, hdrops); 718 error = EINVAL; 719 goto bad; 720 } 721 /* ipn will now contain the inner IPv4 header */ 722 m_striphdr(m, 0, skip); 723 skip = 0; 724 #ifdef notyet 725 /* 726 * Check that the inner source address is the same as 727 * the proxy address, if available. 728 */ 729 if ((saidx->proxy.sa.sa_family == AF_INET && 730 saidx->proxy.sin.sin_addr.s_addr != INADDR_ANY && 731 ipn.ip_src.s_addr != saidx->proxy.sin.sin_addr.s_addr) || 732 (saidx->proxy.sa.sa_family != AF_INET && 733 saidx->proxy.sa.sa_family != 0)) { 734 735 DPRINTF(("%s: inner source address %s doesn't " 736 "correspond to expected proxy source %s, " 737 "SA %s/%08lx\n", __func__, 738 inet_ntoa4(ipn.ip_src), 739 ipsec_address(&saidx->proxy), 740 ipsec_address(&saidx->dst), 741 (u_long) ntohl(sav->spi))); 742 743 IPSEC_ISTAT(sproto, pdrops); 744 error = EACCES; 745 goto bad; 746 } 747 #endif /* notyet */ 748 } 749 #endif /* INET */ 750 else { 751 prot = IPPROTO_IPV6; /* for correct BPF processing */ 752 } 753 754 /* 755 * Record what we've done to the packet (under what SA it was 756 * processed). 757 */ 758 if (sproto != IPPROTO_IPCOMP) { 759 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE, 760 sizeof(struct tdb_ident), M_NOWAIT); 761 if (mtag == NULL) { 762 DPRINTF(("%s: failed to get tag\n", __func__)); 763 IPSEC_ISTAT(sproto, hdrops); 764 error = ENOMEM; 765 goto bad; 766 } 767 768 tdbi = (struct tdb_ident *)(mtag + 1); 769 bcopy(&saidx->dst, &tdbi->dst, sizeof(union sockaddr_union)); 770 tdbi->proto = sproto; 771 tdbi->spi = sav->spi; 772 /* Cache those two for enc(4) in xform_ipip. */ 773 tdbi->alg_auth = sav->alg_auth; 774 tdbi->alg_enc = sav->alg_enc; 775 776 m_tag_prepend(m, mtag); 777 } 778 779 key_sa_recordxfer(sav, m); 780 781 #ifdef DEV_ENC 782 /* 783 * Pass the mbuf to enc0 for bpf and pfil. 784 */ 785 #ifdef INET 786 if (prot == IPPROTO_IPIP) 787 ipsec_bpf(m, sav, AF_INET, ENC_IN|ENC_AFTER); 788 #endif 789 if (prot == IPPROTO_IPV6) 790 ipsec_bpf(m, sav, AF_INET6, ENC_IN|ENC_AFTER); 791 792 if ((error = ipsec_filter(&m, PFIL_IN, ENC_IN|ENC_AFTER)) != 0) 793 return (error); 794 #endif /* DEV_ENC */ 795 if (skip == 0) { 796 /* 797 * We stripped outer IPv6 header. 798 * Now we should requeue decrypted packet via netisr. 799 */ 800 switch (prot) { 801 #ifdef INET 802 case IPPROTO_IPIP: 803 isr_prot = NETISR_IP; 804 break; 805 #endif 806 case IPPROTO_IPV6: 807 isr_prot = NETISR_IPV6; 808 break; 809 default: 810 DPRINTF(("%s: cannot handle inner ip proto %d\n", 811 __func__, prot)); 812 IPSEC_ISTAT(sproto, nopf); 813 error = EPFNOSUPPORT; 814 goto bad; 815 } 816 error = netisr_queue_src(isr_prot, (uintptr_t)sav->spi, m); 817 if (error) { 818 IPSEC_ISTAT(sproto, qfull); 819 DPRINTF(("%s: queue full; proto %u packet dropped\n", 820 __func__, sproto)); 821 } 822 return (error); 823 } 824 /* 825 * See the end of ip6_input for this logic. 826 * IPPROTO_IPV[46] case will be processed just like other ones 827 */ 828 nest = 0; 829 nxt = nxt8; 830 while (nxt != IPPROTO_DONE) { 831 if (V_ip6_hdrnestlimit && (++nest > V_ip6_hdrnestlimit)) { 832 IP6STAT_INC(ip6s_toomanyhdr); 833 error = EINVAL; 834 goto bad; 835 } 836 837 /* 838 * Protection against faulty packet - there should be 839 * more sanity checks in header chain processing. 840 */ 841 if (m->m_pkthdr.len < skip) { 842 IP6STAT_INC(ip6s_tooshort); 843 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 844 error = EINVAL; 845 goto bad; 846 } 847 /* 848 * Enforce IPsec policy checking if we are seeing last header. 849 * note that we do not visit this with protocols with pcb layer 850 * code - like udp/tcp/raw ip. 851 */ 852 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 853 ipsec6_in_reject(m, NULL)) { 854 error = EINVAL; 855 goto bad; 856 } 857 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &skip, nxt); 858 } 859 return 0; 860 bad: 861 if (m) 862 m_freem(m); 863 return error; 864 } 865 866 void 867 esp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 868 { 869 struct ip6ctlparam *ip6cp = NULL; 870 struct mbuf *m = NULL; 871 struct ip6_hdr *ip6; 872 int off; 873 874 if (sa->sa_family != AF_INET6 || 875 sa->sa_len != sizeof(struct sockaddr_in6)) 876 return; 877 if ((unsigned)cmd >= PRC_NCMDS) 878 return; 879 880 /* if the parameter is from icmp6, decode it. */ 881 if (d != NULL) { 882 ip6cp = (struct ip6ctlparam *)d; 883 m = ip6cp->ip6c_m; 884 ip6 = ip6cp->ip6c_ip6; 885 off = ip6cp->ip6c_off; 886 } else { 887 m = NULL; 888 ip6 = NULL; 889 off = 0; /* calm gcc */ 890 } 891 892 if (ip6 != NULL) { 893 894 struct ip6ctlparam ip6cp1; 895 896 /* 897 * Notify the error to all possible sockets via pfctlinput2. 898 * Since the upper layer information (such as protocol type, 899 * source and destination ports) is embedded in the encrypted 900 * data and might have been cut, we can't directly call 901 * an upper layer ctlinput function. However, the pcbnotify 902 * function will consider source and destination addresses 903 * as well as the flow info value, and may be able to find 904 * some PCB that should be notified. 905 * Although pfctlinput2 will call esp6_ctlinput(), there is 906 * no possibility of an infinite loop of function calls, 907 * because we don't pass the inner IPv6 header. 908 */ 909 bzero(&ip6cp1, sizeof(ip6cp1)); 910 ip6cp1.ip6c_src = ip6cp->ip6c_src; 911 pfctlinput2(cmd, sa, (void *)&ip6cp1); 912 913 /* 914 * Then go to special cases that need ESP header information. 915 * XXX: We assume that when ip6 is non NULL, 916 * M and OFF are valid. 917 */ 918 919 if (cmd == PRC_MSGSIZE) { 920 struct secasvar *sav; 921 u_int32_t spi; 922 int valid; 923 924 /* check header length before using m_copydata */ 925 if (m->m_pkthdr.len < off + sizeof (struct esp)) 926 return; 927 m_copydata(m, off + offsetof(struct esp, esp_spi), 928 sizeof(u_int32_t), (caddr_t) &spi); 929 /* 930 * Check to see if we have a valid SA corresponding to 931 * the address in the ICMP message payload. 932 */ 933 sav = KEY_ALLOCSA((union sockaddr_union *)sa, 934 IPPROTO_ESP, spi); 935 valid = (sav != NULL); 936 if (sav) 937 KEY_FREESAV(&sav); 938 939 /* XXX Further validation? */ 940 941 /* 942 * Depending on whether the SA is "valid" and 943 * routing table size (mtudisc_{hi,lo}wat), we will: 944 * - recalcurate the new MTU and create the 945 * corresponding routing entry, or 946 * - ignore the MTU change notification. 947 */ 948 icmp6_mtudisc_update(ip6cp, valid); 949 } 950 } else { 951 /* we normally notify any pcb here */ 952 } 953 } 954 #endif /* INET6 */ 955