1 /* $OpenBSD: ipsec_input.c,v 1.180 2021/09/29 22:08:13 bluhm Exp $ */ 2 /* 3 * The authors of this code are John Ioannidis (ji@tla.org), 4 * Angelos D. Keromytis (kermit@csd.uch.gr) and 5 * Niels Provos (provos@physnet.uni-hamburg.de). 6 * 7 * This code was written by John Ioannidis for BSD/OS in Athens, Greece, 8 * in November 1995. 9 * 10 * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996, 11 * by Angelos D. Keromytis. 12 * 13 * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis 14 * and Niels Provos. 15 * 16 * Additional features in 1999 by Angelos D. Keromytis. 17 * 18 * Copyright (C) 1995, 1996, 1997, 1998, 1999 by John Ioannidis, 19 * Angelos D. Keromytis and Niels Provos. 20 * Copyright (c) 2001, Angelos D. Keromytis. 21 * 22 * Permission to use, copy, and modify this software with or without fee 23 * is hereby granted, provided that this entire notice is included in 24 * all copies of any software which is or includes a copy or 25 * modification of this software. 26 * You may use this code under the GNU public license if you so wish. Please 27 * contribute changes back to the authors under this freer than GPL license 28 * so that we may further the use of strong encryption without limitations to 29 * all. 30 * 31 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR 32 * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY 33 * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE 34 * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR 35 * PURPOSE. 36 */ 37 38 #include "pf.h" 39 40 #include <sys/param.h> 41 #include <sys/systm.h> 42 #include <sys/protosw.h> 43 #include <sys/mbuf.h> 44 #include <sys/socket.h> 45 #include <sys/sysctl.h> 46 #include <sys/kernel.h> 47 #include <sys/timeout.h> 48 49 #include <net/if.h> 50 #include <net/if_var.h> 51 #include <net/netisr.h> 52 #include <net/bpf.h> 53 #include <net/route.h> 54 55 #include <netinet/in.h> 56 #include <netinet/ip.h> 57 #include <netinet/ip_var.h> 58 #include <netinet/ip_icmp.h> 59 #include <netinet/tcp.h> 60 #include <netinet/udp.h> 61 62 #if NPF > 0 63 #include <net/pfvar.h> 64 #endif 65 66 #ifdef INET6 67 #include <netinet6/in6_var.h> 68 #include <netinet/ip6.h> 69 #include <netinet6/ip6_var.h> 70 #include <netinet6/ip6protosw.h> 71 #endif /* INET6 */ 72 73 #include <netinet/ip_ipsp.h> 74 #include <netinet/ip_esp.h> 75 #include <netinet/ip_ah.h> 76 #include <netinet/ip_ipcomp.h> 77 78 #include <net/if_enc.h> 79 80 #include <crypto/cryptodev.h> 81 #include <crypto/xform.h> 82 83 #include "bpfilter.h" 84 85 void ipsec_common_ctlinput(u_int, int, struct sockaddr *, void *, int); 86 87 #ifdef ENCDEBUG 88 #define DPRINTF(fmt, args...) \ 89 do { \ 90 if (encdebug) \ 91 printf("%s: " fmt "\n", __func__, ## args); \ 92 } while (0) 93 #else 94 #define DPRINTF(fmt, args...) \ 95 do { } while (0) 96 #endif 97 98 /* sysctl variables */ 99 int encdebug = 0; 100 int ipsec_keep_invalid = IPSEC_DEFAULT_EMBRYONIC_SA_TIMEOUT; 101 int ipsec_require_pfs = IPSEC_DEFAULT_PFS; 102 int ipsec_soft_allocations = IPSEC_DEFAULT_SOFT_ALLOCATIONS; 103 int ipsec_exp_allocations = IPSEC_DEFAULT_EXP_ALLOCATIONS; 104 int ipsec_soft_bytes = IPSEC_DEFAULT_SOFT_BYTES; 105 int ipsec_exp_bytes = IPSEC_DEFAULT_EXP_BYTES; 106 int ipsec_soft_timeout = IPSEC_DEFAULT_SOFT_TIMEOUT; 107 int ipsec_exp_timeout = IPSEC_DEFAULT_EXP_TIMEOUT; 108 int ipsec_soft_first_use = IPSEC_DEFAULT_SOFT_FIRST_USE; 109 int ipsec_exp_first_use = IPSEC_DEFAULT_EXP_FIRST_USE; 110 int ipsec_expire_acquire = IPSEC_DEFAULT_EXPIRE_ACQUIRE; 111 112 int esp_enable = 1; 113 int ah_enable = 1; 114 int ipcomp_enable = 0; 115 116 const struct sysctl_bounded_args espctl_vars[] = { 117 {ESPCTL_ENABLE, &esp_enable, 0, 1}, 118 {ESPCTL_UDPENCAP_ENABLE, &udpencap_enable, 0, 1}, 119 {ESPCTL_UDPENCAP_PORT, &udpencap_port, 0, 65535}, 120 }; 121 const struct sysctl_bounded_args ahctl_vars[] = { 122 {AHCTL_ENABLE, &ah_enable, 0, 1}, 123 }; 124 const struct sysctl_bounded_args ipcompctl_vars[] = { 125 {IPCOMPCTL_ENABLE, &ipcomp_enable, 0, 1}, 126 }; 127 128 struct cpumem *espcounters; 129 struct cpumem *ahcounters; 130 struct cpumem *ipcompcounters; 131 struct cpumem *ipseccounters; 132 133 char ipsec_def_enc[20]; 134 char ipsec_def_auth[20]; 135 char ipsec_def_comp[20]; 136 137 const struct sysctl_bounded_args ipsecctl_vars[] = { 138 { IPSEC_ENCDEBUG, &encdebug, 0, 1 }, 139 { IPSEC_EXPIRE_ACQUIRE, &ipsec_expire_acquire, 0, INT_MAX }, 140 { IPSEC_EMBRYONIC_SA_TIMEOUT, &ipsec_keep_invalid, 0, INT_MAX }, 141 { IPSEC_REQUIRE_PFS, &ipsec_require_pfs, 0, 1 }, 142 { IPSEC_SOFT_ALLOCATIONS, &ipsec_soft_allocations, 0, INT_MAX }, 143 { IPSEC_ALLOCATIONS, &ipsec_exp_allocations, 0, INT_MAX }, 144 { IPSEC_SOFT_BYTES, &ipsec_soft_bytes, 0, INT_MAX }, 145 { IPSEC_BYTES, &ipsec_exp_bytes, 0, INT_MAX }, 146 { IPSEC_TIMEOUT, &ipsec_exp_timeout, 0, INT_MAX }, 147 { IPSEC_SOFT_TIMEOUT, &ipsec_soft_timeout,0, INT_MAX }, 148 { IPSEC_SOFT_FIRSTUSE, &ipsec_soft_first_use, 0, INT_MAX }, 149 { IPSEC_FIRSTUSE, &ipsec_exp_first_use, 0, INT_MAX }, 150 }; 151 152 int esp_sysctl_espstat(void *, size_t *, void *); 153 int ah_sysctl_ahstat(void *, size_t *, void *); 154 int ipcomp_sysctl_ipcompstat(void *, size_t *, void *); 155 int ipsec_sysctl_ipsecstat(void *, size_t *, void *); 156 157 void 158 ipsec_init(void) 159 { 160 espcounters = counters_alloc(esps_ncounters); 161 ahcounters = counters_alloc(ahs_ncounters); 162 ipcompcounters = counters_alloc(ipcomps_ncounters); 163 ipseccounters = counters_alloc(ipsec_ncounters); 164 165 strlcpy(ipsec_def_enc, IPSEC_DEFAULT_DEF_ENC, sizeof(ipsec_def_enc)); 166 strlcpy(ipsec_def_auth, IPSEC_DEFAULT_DEF_AUTH, sizeof(ipsec_def_auth)); 167 strlcpy(ipsec_def_comp, IPSEC_DEFAULT_DEF_COMP, sizeof(ipsec_def_comp)); 168 169 ipsp_init(); 170 } 171 172 /* 173 * ipsec_common_input() gets called when we receive an IPsec-protected packet 174 * in IPv4 or IPv6. All it does is find the right TDB and call the appropriate 175 * transform. The callback takes care of further processing (like ingress 176 * filtering). 177 */ 178 int 179 ipsec_common_input(struct mbuf *m, int skip, int protoff, int af, int sproto, 180 int udpencap) 181 { 182 #define IPSEC_ISTAT(x,y,z) do { \ 183 if (sproto == IPPROTO_ESP) \ 184 espstat_inc(x); \ 185 else if (sproto == IPPROTO_AH) \ 186 ahstat_inc(y); \ 187 else \ 188 ipcompstat_inc(z); \ 189 } while (0) 190 191 union sockaddr_union dst_address; 192 struct tdb *tdbp = NULL; 193 struct ifnet *encif; 194 u_int32_t spi; 195 u_int16_t cpi; 196 int error; 197 #ifdef ENCDEBUG 198 char buf[INET6_ADDRSTRLEN]; 199 #endif 200 201 NET_ASSERT_LOCKED(); 202 203 ipsecstat_inc(ipsec_ipackets); 204 ipsecstat_add(ipsec_ibytes, m->m_pkthdr.len); 205 IPSEC_ISTAT(esps_input, ahs_input, ipcomps_input); 206 207 if (m == NULL) { 208 DPRINTF("NULL packet received"); 209 IPSEC_ISTAT(esps_hdrops, ahs_hdrops, ipcomps_hdrops); 210 return EINVAL; 211 } 212 213 if ((sproto == IPPROTO_IPCOMP) && (m->m_flags & M_COMP)) { 214 DPRINTF("repeated decompression"); 215 ipcompstat_inc(ipcomps_pdrops); 216 error = EINVAL; 217 goto drop; 218 } 219 220 if (m->m_pkthdr.len - skip < 2 * sizeof(u_int32_t)) { 221 DPRINTF("packet too small"); 222 IPSEC_ISTAT(esps_hdrops, ahs_hdrops, ipcomps_hdrops); 223 error = EINVAL; 224 goto drop; 225 } 226 227 /* Retrieve the SPI from the relevant IPsec header */ 228 switch (sproto) { 229 case IPPROTO_ESP: 230 m_copydata(m, skip, sizeof(u_int32_t), (caddr_t) &spi); 231 break; 232 case IPPROTO_AH: 233 m_copydata(m, skip + sizeof(u_int32_t), sizeof(u_int32_t), 234 (caddr_t) &spi); 235 break; 236 case IPPROTO_IPCOMP: 237 m_copydata(m, skip + sizeof(u_int16_t), sizeof(u_int16_t), 238 (caddr_t) &cpi); 239 spi = ntohl(htons(cpi)); 240 break; 241 default: 242 panic("%s: unknown/unsupported security protocol %d", 243 __func__, sproto); 244 } 245 246 /* 247 * Find tunnel control block and (indirectly) call the appropriate 248 * kernel crypto routine. The resulting mbuf chain is a valid 249 * IP packet ready to go through input processing. 250 */ 251 252 memset(&dst_address, 0, sizeof(dst_address)); 253 dst_address.sa.sa_family = af; 254 255 switch (af) { 256 case AF_INET: 257 dst_address.sin.sin_len = sizeof(struct sockaddr_in); 258 m_copydata(m, offsetof(struct ip, ip_dst), 259 sizeof(struct in_addr), 260 (caddr_t) &(dst_address.sin.sin_addr)); 261 break; 262 263 #ifdef INET6 264 case AF_INET6: 265 dst_address.sin6.sin6_len = sizeof(struct sockaddr_in6); 266 m_copydata(m, offsetof(struct ip6_hdr, ip6_dst), 267 sizeof(struct in6_addr), 268 (caddr_t) &(dst_address.sin6.sin6_addr)); 269 in6_recoverscope(&dst_address.sin6, 270 &dst_address.sin6.sin6_addr); 271 break; 272 #endif /* INET6 */ 273 274 default: 275 DPRINTF("unsupported protocol family %d", af); 276 IPSEC_ISTAT(esps_nopf, ahs_nopf, ipcomps_nopf); 277 error = EPFNOSUPPORT; 278 goto drop; 279 } 280 281 tdbp = gettdb(rtable_l2(m->m_pkthdr.ph_rtableid), 282 spi, &dst_address, sproto); 283 if (tdbp == NULL) { 284 DPRINTF("could not find SA for packet to %s, spi %08x", 285 ipsp_address(&dst_address, buf, sizeof(buf)), ntohl(spi)); 286 IPSEC_ISTAT(esps_notdb, ahs_notdb, ipcomps_notdb); 287 error = ENOENT; 288 goto drop; 289 } 290 291 if (tdbp->tdb_flags & TDBF_INVALID) { 292 DPRINTF("attempted to use invalid SA %s/%08x/%u", 293 ipsp_address(&dst_address, buf, sizeof(buf)), 294 ntohl(spi), tdbp->tdb_sproto); 295 IPSEC_ISTAT(esps_invalid, ahs_invalid, ipcomps_invalid); 296 error = EINVAL; 297 goto drop; 298 } 299 300 if (udpencap && !(tdbp->tdb_flags & TDBF_UDPENCAP)) { 301 DPRINTF("attempted to use non-udpencap SA %s/%08x/%u", 302 ipsp_address(&dst_address, buf, sizeof(buf)), 303 ntohl(spi), tdbp->tdb_sproto); 304 espstat_inc(esps_udpinval); 305 error = EINVAL; 306 goto drop; 307 } 308 309 if (!udpencap && (tdbp->tdb_flags & TDBF_UDPENCAP)) { 310 DPRINTF("attempted to use udpencap SA %s/%08x/%u", 311 ipsp_address(&dst_address, buf, sizeof(buf)), 312 ntohl(spi), tdbp->tdb_sproto); 313 espstat_inc(esps_udpneeded); 314 error = EINVAL; 315 goto drop; 316 } 317 318 if (tdbp->tdb_xform == NULL) { 319 DPRINTF("attempted to use uninitialized SA %s/%08x/%u", 320 ipsp_address(&dst_address, buf, sizeof(buf)), 321 ntohl(spi), tdbp->tdb_sproto); 322 IPSEC_ISTAT(esps_noxform, ahs_noxform, ipcomps_noxform); 323 error = ENXIO; 324 goto drop; 325 } 326 327 if (sproto != IPPROTO_IPCOMP) { 328 if ((encif = enc_getif(tdbp->tdb_rdomain_post, 329 tdbp->tdb_tap)) == NULL) { 330 DPRINTF("no enc%u interface for SA %s/%08x/%u", 331 tdbp->tdb_tap, 332 ipsp_address(&dst_address, buf, sizeof(buf)), 333 ntohl(spi), tdbp->tdb_sproto); 334 IPSEC_ISTAT(esps_pdrops, ahs_pdrops, ipcomps_pdrops); 335 error = EACCES; 336 goto drop; 337 } 338 339 /* XXX This conflicts with the scoped nature of IPv6 */ 340 m->m_pkthdr.ph_ifidx = encif->if_index; 341 } 342 343 /* Register first use, setup expiration timer. */ 344 if (tdbp->tdb_first_use == 0) { 345 tdbp->tdb_first_use = gettime(); 346 if (tdbp->tdb_flags & TDBF_FIRSTUSE) 347 timeout_add_sec(&tdbp->tdb_first_tmo, 348 tdbp->tdb_exp_first_use); 349 if (tdbp->tdb_flags & TDBF_SOFT_FIRSTUSE) 350 timeout_add_sec(&tdbp->tdb_sfirst_tmo, 351 tdbp->tdb_soft_first_use); 352 } 353 354 tdbp->tdb_ipackets++; 355 tdbp->tdb_ibytes += m->m_pkthdr.len; 356 357 /* 358 * Call appropriate transform and return -- callback takes care of 359 * everything else. 360 */ 361 error = (*(tdbp->tdb_xform->xf_input))(m, tdbp, skip, protoff); 362 if (error) { 363 ipsecstat_inc(ipsec_idrops); 364 tdbp->tdb_idrops++; 365 } 366 return error; 367 368 drop: 369 ipsecstat_inc(ipsec_idrops); 370 if (tdbp != NULL) 371 tdbp->tdb_idrops++; 372 m_freem(m); 373 return error; 374 } 375 376 void 377 ipsec_input_cb(struct cryptop *crp) 378 { 379 struct tdb_crypto *tc = (struct tdb_crypto *) crp->crp_opaque; 380 struct mbuf *m = (struct mbuf *) crp->crp_buf; 381 struct tdb *tdb = NULL; 382 int clen, error; 383 384 NET_ASSERT_LOCKED(); 385 386 if (m == NULL) { 387 DPRINTF("bogus returned buffer from crypto"); 388 ipsecstat_inc(ipsec_crypto); 389 goto drop; 390 } 391 392 tdb = gettdb(tc->tc_rdomain, tc->tc_spi, &tc->tc_dst, tc->tc_proto); 393 if (tdb == NULL) { 394 DPRINTF("TDB is expired while in crypto"); 395 ipsecstat_inc(ipsec_notdb); 396 goto drop; 397 } 398 399 /* Check for crypto errors */ 400 if (crp->crp_etype) { 401 if (crp->crp_etype == EAGAIN) { 402 /* Reset the session ID */ 403 if (tdb->tdb_cryptoid != 0) 404 tdb->tdb_cryptoid = crp->crp_sid; 405 error = crypto_dispatch(crp); 406 if (error) { 407 DPRINTF("crypto dispatch error %d", error); 408 goto drop; 409 } 410 return; 411 } 412 DPRINTF("crypto error %d", crp->crp_etype); 413 ipsecstat_inc(ipsec_noxform); 414 goto drop; 415 } 416 417 /* Length of data after processing */ 418 clen = crp->crp_olen; 419 420 /* Release the crypto descriptors */ 421 crypto_freereq(crp); 422 423 switch (tdb->tdb_sproto) { 424 case IPPROTO_ESP: 425 error = esp_input_cb(tdb, tc, m, clen); 426 break; 427 case IPPROTO_AH: 428 error = ah_input_cb(tdb, tc, m, clen); 429 break; 430 case IPPROTO_IPCOMP: 431 error = ipcomp_input_cb(tdb, tc, m, clen); 432 break; 433 default: 434 panic("%s: unknown/unsupported security protocol %d", 435 __func__, tdb->tdb_sproto); 436 } 437 438 if (error) { 439 ipsecstat_inc(ipsec_idrops); 440 tdb->tdb_idrops++; 441 } 442 return; 443 444 drop: 445 ipsecstat_inc(ipsec_idrops); 446 if (tdb != NULL) 447 tdb->tdb_idrops++; 448 free(tc, M_XDATA, 0); 449 m_freem(m); 450 crypto_freereq(crp); 451 } 452 453 /* 454 * IPsec input callback, called by the transform callback. Takes care of 455 * filtering and other sanity checks on the processed packet. 456 */ 457 int 458 ipsec_common_input_cb(struct mbuf *m, struct tdb *tdbp, int skip, int protoff) 459 { 460 int af, sproto; 461 u_int8_t prot; 462 463 #if NBPFILTER > 0 464 struct ifnet *encif; 465 #endif 466 467 struct ip *ip, ipn; 468 469 #ifdef INET6 470 struct ip6_hdr *ip6, ip6n; 471 #endif /* INET6 */ 472 struct m_tag *mtag; 473 struct tdb_ident *tdbi; 474 475 #ifdef ENCDEBUG 476 char buf[INET6_ADDRSTRLEN]; 477 #endif 478 479 af = tdbp->tdb_dst.sa.sa_family; 480 sproto = tdbp->tdb_sproto; 481 482 tdbp->tdb_last_used = gettime(); 483 484 /* Sanity check */ 485 if (m == NULL) { 486 /* The called routine will print a message if necessary */ 487 IPSEC_ISTAT(esps_badkcr, ahs_badkcr, ipcomps_badkcr); 488 return -1; 489 } 490 491 /* Fix IPv4 header */ 492 if (af == AF_INET) { 493 if ((m->m_len < skip) && ((m = m_pullup(m, skip)) == NULL)) { 494 DPRINTF("processing failed for SA %s/%08x", 495 ipsp_address(&tdbp->tdb_dst, buf, sizeof(buf)), 496 ntohl(tdbp->tdb_spi)); 497 IPSEC_ISTAT(esps_hdrops, ahs_hdrops, ipcomps_hdrops); 498 return -1; 499 } 500 501 ip = mtod(m, struct ip *); 502 ip->ip_len = htons(m->m_pkthdr.len); 503 ip->ip_sum = 0; 504 ip->ip_sum = in_cksum(m, ip->ip_hl << 2); 505 prot = ip->ip_p; 506 507 /* IP-in-IP encapsulation */ 508 if (prot == IPPROTO_IPIP) { 509 if (m->m_pkthdr.len - skip < sizeof(struct ip)) { 510 m_freem(m); 511 IPSEC_ISTAT(esps_hdrops, ahs_hdrops, 512 ipcomps_hdrops); 513 return -1; 514 } 515 /* ipn will now contain the inner IPv4 header */ 516 m_copydata(m, skip, sizeof(struct ip), 517 (caddr_t) &ipn); 518 } 519 520 #ifdef INET6 521 /* IPv6-in-IP encapsulation. */ 522 if (prot == IPPROTO_IPV6) { 523 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) { 524 m_freem(m); 525 IPSEC_ISTAT(esps_hdrops, ahs_hdrops, 526 ipcomps_hdrops); 527 return -1; 528 } 529 /* ip6n will now contain the inner IPv6 header. */ 530 m_copydata(m, skip, sizeof(struct ip6_hdr), 531 (caddr_t) &ip6n); 532 } 533 #endif /* INET6 */ 534 } 535 536 #ifdef INET6 537 /* Fix IPv6 header */ 538 if (af == AF_INET6) 539 { 540 if (m->m_len < sizeof(struct ip6_hdr) && 541 (m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 542 543 DPRINTF("processing failed for SA %s/%08x", 544 ipsp_address(&tdbp->tdb_dst, buf, sizeof(buf)), 545 ntohl(tdbp->tdb_spi)); 546 IPSEC_ISTAT(esps_hdrops, ahs_hdrops, ipcomps_hdrops); 547 return -1; 548 } 549 550 ip6 = mtod(m, struct ip6_hdr *); 551 ip6->ip6_plen = htons(m->m_pkthdr.len - skip); 552 553 /* Save protocol */ 554 m_copydata(m, protoff, 1, (caddr_t) &prot); 555 556 /* IP-in-IP encapsulation */ 557 if (prot == IPPROTO_IPIP) { 558 if (m->m_pkthdr.len - skip < sizeof(struct ip)) { 559 m_freem(m); 560 IPSEC_ISTAT(esps_hdrops, ahs_hdrops, 561 ipcomps_hdrops); 562 return -1; 563 } 564 /* ipn will now contain the inner IPv4 header */ 565 m_copydata(m, skip, sizeof(struct ip), (caddr_t) &ipn); 566 } 567 568 /* IPv6-in-IP encapsulation */ 569 if (prot == IPPROTO_IPV6) { 570 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) { 571 m_freem(m); 572 IPSEC_ISTAT(esps_hdrops, ahs_hdrops, 573 ipcomps_hdrops); 574 return -1; 575 } 576 /* ip6n will now contain the inner IPv6 header. */ 577 m_copydata(m, skip, sizeof(struct ip6_hdr), 578 (caddr_t) &ip6n); 579 } 580 } 581 #endif /* INET6 */ 582 583 /* 584 * Fix TCP/UDP checksum of UDP encapsulated transport mode ESP packet. 585 * (RFC3948 3.1.2) 586 */ 587 if ((af == AF_INET || af == AF_INET6) && 588 (tdbp->tdb_flags & TDBF_UDPENCAP) && 589 (tdbp->tdb_flags & TDBF_TUNNELING) == 0) { 590 u_int16_t cksum; 591 592 switch (prot) { 593 case IPPROTO_UDP: 594 if (m->m_pkthdr.len < skip + sizeof(struct udphdr)) { 595 m_freem(m); 596 IPSEC_ISTAT(esps_hdrops, ahs_hdrops, 597 ipcomps_hdrops); 598 return -1; 599 } 600 cksum = 0; 601 m_copyback(m, skip + offsetof(struct udphdr, uh_sum), 602 sizeof(cksum), &cksum, M_NOWAIT); 603 #ifdef INET6 604 if (af == AF_INET6) { 605 cksum = in6_cksum(m, IPPROTO_UDP, skip, 606 m->m_pkthdr.len - skip); 607 m_copyback(m, skip + offsetof(struct udphdr, 608 uh_sum), sizeof(cksum), &cksum, M_NOWAIT); 609 } 610 #endif 611 break; 612 case IPPROTO_TCP: 613 if (m->m_pkthdr.len < skip + sizeof(struct tcphdr)) { 614 m_freem(m); 615 IPSEC_ISTAT(esps_hdrops, ahs_hdrops, 616 ipcomps_hdrops); 617 return -1; 618 } 619 cksum = 0; 620 m_copyback(m, skip + offsetof(struct tcphdr, th_sum), 621 sizeof(cksum), &cksum, M_NOWAIT); 622 if (af == AF_INET) 623 cksum = in4_cksum(m, IPPROTO_TCP, skip, 624 m->m_pkthdr.len - skip); 625 #ifdef INET6 626 else if (af == AF_INET6) 627 cksum = in6_cksum(m, IPPROTO_TCP, skip, 628 m->m_pkthdr.len - skip); 629 #endif 630 m_copyback(m, skip + offsetof(struct tcphdr, th_sum), 631 sizeof(cksum), &cksum, M_NOWAIT); 632 break; 633 } 634 } 635 636 /* 637 * Record what we've done to the packet (under what SA it was 638 * processed). 639 */ 640 if (tdbp->tdb_sproto != IPPROTO_IPCOMP) { 641 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE, 642 sizeof(struct tdb_ident), M_NOWAIT); 643 if (mtag == NULL) { 644 m_freem(m); 645 DPRINTF("failed to get tag"); 646 IPSEC_ISTAT(esps_hdrops, ahs_hdrops, ipcomps_hdrops); 647 return -1; 648 } 649 650 tdbi = (struct tdb_ident *)(mtag + 1); 651 tdbi->dst = tdbp->tdb_dst; 652 tdbi->proto = tdbp->tdb_sproto; 653 tdbi->spi = tdbp->tdb_spi; 654 tdbi->rdomain = tdbp->tdb_rdomain; 655 656 m_tag_prepend(m, mtag); 657 } 658 659 switch (sproto) { 660 case IPPROTO_ESP: 661 /* Packet is confidential ? */ 662 if (tdbp->tdb_encalgxform) 663 m->m_flags |= M_CONF; 664 665 /* Check if we had authenticated ESP. */ 666 if (tdbp->tdb_authalgxform) 667 m->m_flags |= M_AUTH; 668 break; 669 case IPPROTO_AH: 670 m->m_flags |= M_AUTH; 671 break; 672 case IPPROTO_IPCOMP: 673 m->m_flags |= M_COMP; 674 break; 675 default: 676 panic("%s: unknown/unsupported security protocol %d", 677 __func__, sproto); 678 } 679 680 #if NPF > 0 681 /* Add pf tag if requested. */ 682 pf_tag_packet(m, tdbp->tdb_tag, -1); 683 pf_pkt_addr_changed(m); 684 #endif 685 if (tdbp->tdb_rdomain != tdbp->tdb_rdomain_post) 686 m->m_pkthdr.ph_rtableid = tdbp->tdb_rdomain_post; 687 688 if (tdbp->tdb_flags & TDBF_TUNNELING) 689 m->m_flags |= M_TUNNEL; 690 691 ipsecstat_add(ipsec_idecompbytes, m->m_pkthdr.len); 692 tdbp->tdb_idecompbytes += m->m_pkthdr.len; 693 694 #if NBPFILTER > 0 695 if ((encif = enc_getif(tdbp->tdb_rdomain_post, tdbp->tdb_tap)) != NULL) { 696 encif->if_ipackets++; 697 encif->if_ibytes += m->m_pkthdr.len; 698 699 if (encif->if_bpf) { 700 struct enchdr hdr; 701 702 hdr.af = af; 703 hdr.spi = tdbp->tdb_spi; 704 hdr.flags = m->m_flags & (M_AUTH|M_CONF); 705 706 bpf_mtap_hdr(encif->if_bpf, (char *)&hdr, 707 ENC_HDRLEN, m, BPF_DIRECTION_IN); 708 } 709 } 710 #endif 711 712 #if NPF > 0 713 /* 714 * The ip_deliver() shortcut avoids running through ip_input() with the 715 * same IP header twice. Packets in transport mode have to be be 716 * passed to pf explicitly. In tunnel mode the inner IP header will 717 * run through ip_input() and pf anyway. 718 */ 719 if ((tdbp->tdb_flags & TDBF_TUNNELING) == 0) { 720 struct ifnet *ifp; 721 722 /* This is the enc0 interface unless for ipcomp. */ 723 if ((ifp = if_get(m->m_pkthdr.ph_ifidx)) == NULL) { 724 m_freem(m); 725 return -1; 726 } 727 if (pf_test(af, PF_IN, ifp, &m) != PF_PASS) { 728 if_put(ifp); 729 m_freem(m); 730 return -1; 731 } 732 if_put(ifp); 733 if (m == NULL) 734 return -1; 735 } 736 #endif 737 /* Call the appropriate IPsec transform callback. */ 738 ip_deliver(&m, &skip, prot, af); 739 return 0; 740 #undef IPSEC_ISTAT 741 } 742 743 int 744 ipsec_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp, 745 size_t newlen) 746 { 747 int error; 748 749 switch (name[0]) { 750 case IPCTL_IPSEC_ENC_ALGORITHM: 751 NET_LOCK(); 752 error = sysctl_tstring(oldp, oldlenp, newp, newlen, 753 ipsec_def_enc, sizeof(ipsec_def_enc)); 754 NET_UNLOCK(); 755 return (error); 756 case IPCTL_IPSEC_AUTH_ALGORITHM: 757 NET_LOCK(); 758 error = sysctl_tstring(oldp, oldlenp, newp, newlen, 759 ipsec_def_auth, sizeof(ipsec_def_auth)); 760 NET_UNLOCK(); 761 return (error); 762 case IPCTL_IPSEC_IPCOMP_ALGORITHM: 763 NET_LOCK(); 764 error = sysctl_tstring(oldp, oldlenp, newp, newlen, 765 ipsec_def_comp, sizeof(ipsec_def_comp)); 766 NET_UNLOCK(); 767 return (error); 768 case IPCTL_IPSEC_STATS: 769 return (ipsec_sysctl_ipsecstat(oldp, oldlenp, newp)); 770 default: 771 NET_LOCK(); 772 error = sysctl_bounded_arr(ipsecctl_vars, nitems(ipsecctl_vars), 773 name, namelen, oldp, oldlenp, newp, newlen); 774 NET_UNLOCK(); 775 return (error); 776 } 777 } 778 779 int 780 esp_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp, 781 size_t newlen) 782 { 783 int error; 784 785 /* All sysctl names at this level are terminal. */ 786 if (namelen != 1) 787 return (ENOTDIR); 788 789 switch (name[0]) { 790 case ESPCTL_STATS: 791 return (esp_sysctl_espstat(oldp, oldlenp, newp)); 792 default: 793 NET_LOCK(); 794 error = sysctl_bounded_arr(espctl_vars, nitems(espctl_vars), 795 name, namelen, oldp, oldlenp, newp, newlen); 796 NET_UNLOCK(); 797 return (error); 798 } 799 } 800 801 int 802 esp_sysctl_espstat(void *oldp, size_t *oldlenp, void *newp) 803 { 804 struct espstat espstat; 805 806 CTASSERT(sizeof(espstat) == (esps_ncounters * sizeof(uint64_t))); 807 memset(&espstat, 0, sizeof espstat); 808 counters_read(espcounters, (uint64_t *)&espstat, esps_ncounters); 809 return (sysctl_rdstruct(oldp, oldlenp, newp, &espstat, 810 sizeof(espstat))); 811 } 812 813 int 814 ah_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp, 815 size_t newlen) 816 { 817 int error; 818 819 /* All sysctl names at this level are terminal. */ 820 if (namelen != 1) 821 return (ENOTDIR); 822 823 switch (name[0]) { 824 case AHCTL_STATS: 825 return ah_sysctl_ahstat(oldp, oldlenp, newp); 826 default: 827 NET_LOCK(); 828 error = sysctl_bounded_arr(ahctl_vars, nitems(ahctl_vars), name, 829 namelen, oldp, oldlenp, newp, newlen); 830 NET_UNLOCK(); 831 return (error); 832 } 833 } 834 835 int 836 ah_sysctl_ahstat(void *oldp, size_t *oldlenp, void *newp) 837 { 838 struct ahstat ahstat; 839 840 CTASSERT(sizeof(ahstat) == (ahs_ncounters * sizeof(uint64_t))); 841 memset(&ahstat, 0, sizeof ahstat); 842 counters_read(ahcounters, (uint64_t *)&ahstat, ahs_ncounters); 843 return (sysctl_rdstruct(oldp, oldlenp, newp, &ahstat, sizeof(ahstat))); 844 } 845 846 int 847 ipcomp_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp, 848 size_t newlen) 849 { 850 int error; 851 852 /* All sysctl names at this level are terminal. */ 853 if (namelen != 1) 854 return (ENOTDIR); 855 856 switch (name[0]) { 857 case IPCOMPCTL_STATS: 858 return ipcomp_sysctl_ipcompstat(oldp, oldlenp, newp); 859 default: 860 NET_LOCK(); 861 error = sysctl_bounded_arr(ipcompctl_vars, 862 nitems(ipcompctl_vars), name, namelen, oldp, oldlenp, 863 newp, newlen); 864 NET_UNLOCK(); 865 return (error); 866 } 867 } 868 869 int 870 ipcomp_sysctl_ipcompstat(void *oldp, size_t *oldlenp, void *newp) 871 { 872 struct ipcompstat ipcompstat; 873 874 CTASSERT(sizeof(ipcompstat) == (ipcomps_ncounters * sizeof(uint64_t))); 875 memset(&ipcompstat, 0, sizeof ipcompstat); 876 counters_read(ipcompcounters, (uint64_t *)&ipcompstat, 877 ipcomps_ncounters); 878 return (sysctl_rdstruct(oldp, oldlenp, newp, &ipcompstat, 879 sizeof(ipcompstat))); 880 } 881 882 int 883 ipsec_sysctl_ipsecstat(void *oldp, size_t *oldlenp, void *newp) 884 { 885 struct ipsecstat ipsecstat; 886 887 CTASSERT(sizeof(ipsecstat) == (ipsec_ncounters * sizeof(uint64_t))); 888 memset(&ipsecstat, 0, sizeof ipsecstat); 889 counters_read(ipseccounters, (uint64_t *)&ipsecstat, ipsec_ncounters); 890 return (sysctl_rdstruct(oldp, oldlenp, newp, &ipsecstat, 891 sizeof(ipsecstat))); 892 } 893 894 /* IPv4 AH wrapper. */ 895 int 896 ah4_input(struct mbuf **mp, int *offp, int proto, int af) 897 { 898 if ( 899 #if NPF > 0 900 ((*mp)->m_pkthdr.pf.flags & PF_TAG_DIVERTED) || 901 #endif 902 !ah_enable) 903 return rip_input(mp, offp, proto, af); 904 905 ipsec_common_input(*mp, *offp, offsetof(struct ip, ip_p), AF_INET, 906 proto, 0); 907 return IPPROTO_DONE; 908 } 909 910 void 911 ah4_ctlinput(int cmd, struct sockaddr *sa, u_int rdomain, void *v) 912 { 913 if (sa->sa_family != AF_INET || 914 sa->sa_len != sizeof(struct sockaddr_in)) 915 return; 916 917 ipsec_common_ctlinput(rdomain, cmd, sa, v, IPPROTO_AH); 918 } 919 920 /* IPv4 ESP wrapper. */ 921 int 922 esp4_input(struct mbuf **mp, int *offp, int proto, int af) 923 { 924 if ( 925 #if NPF > 0 926 ((*mp)->m_pkthdr.pf.flags & PF_TAG_DIVERTED) || 927 #endif 928 !esp_enable) 929 return rip_input(mp, offp, proto, af); 930 931 ipsec_common_input(*mp, *offp, offsetof(struct ip, ip_p), AF_INET, 932 proto, 0); 933 return IPPROTO_DONE; 934 } 935 936 /* IPv4 IPCOMP wrapper */ 937 int 938 ipcomp4_input(struct mbuf **mp, int *offp, int proto, int af) 939 { 940 if ( 941 #if NPF > 0 942 ((*mp)->m_pkthdr.pf.flags & PF_TAG_DIVERTED) || 943 #endif 944 !ipcomp_enable) 945 return rip_input(mp, offp, proto, af); 946 947 ipsec_common_input(*mp, *offp, offsetof(struct ip, ip_p), AF_INET, 948 proto, 0); 949 return IPPROTO_DONE; 950 } 951 952 void 953 ipsec_common_ctlinput(u_int rdomain, int cmd, struct sockaddr *sa, 954 void *v, int proto) 955 { 956 struct ip *ip = v; 957 958 if (cmd == PRC_MSGSIZE && ip && ip_mtudisc && ip->ip_v == 4) { 959 struct tdb *tdbp; 960 struct sockaddr_in dst; 961 struct icmp *icp; 962 int hlen = ip->ip_hl << 2; 963 u_int32_t spi, mtu; 964 ssize_t adjust; 965 966 /* Find the right MTU. */ 967 icp = (struct icmp *)((caddr_t) ip - 968 offsetof(struct icmp, icmp_ip)); 969 mtu = ntohs(icp->icmp_nextmtu); 970 971 /* 972 * Ignore the packet, if we do not receive a MTU 973 * or the MTU is too small to be acceptable. 974 */ 975 if (mtu < 296) 976 return; 977 978 memset(&dst, 0, sizeof(struct sockaddr_in)); 979 dst.sin_family = AF_INET; 980 dst.sin_len = sizeof(struct sockaddr_in); 981 dst.sin_addr.s_addr = ip->ip_dst.s_addr; 982 983 memcpy(&spi, (caddr_t)ip + hlen, sizeof(u_int32_t)); 984 985 tdbp = gettdb_rev(rdomain, spi, (union sockaddr_union *)&dst, 986 proto); 987 if (tdbp == NULL || tdbp->tdb_flags & TDBF_INVALID) 988 return; 989 990 /* Walk the chain backwards to the first tdb */ 991 NET_ASSERT_LOCKED(); 992 for (; tdbp; tdbp = tdbp->tdb_inext) { 993 if (tdbp->tdb_flags & TDBF_INVALID || 994 (adjust = ipsec_hdrsz(tdbp)) == -1) 995 return; 996 997 mtu -= adjust; 998 999 /* Store adjusted MTU in tdb */ 1000 tdbp->tdb_mtu = mtu; 1001 tdbp->tdb_mtutimeout = gettime() + 1002 ip_mtudisc_timeout; 1003 DPRINTF("spi %08x mtu %d adjust %ld", 1004 ntohl(tdbp->tdb_spi), tdbp->tdb_mtu, adjust); 1005 } 1006 } 1007 } 1008 1009 void 1010 udpencap_ctlinput(int cmd, struct sockaddr *sa, u_int rdomain, void *v) 1011 { 1012 struct ip *ip = v; 1013 struct tdb *tdbp; 1014 struct icmp *icp; 1015 u_int32_t mtu; 1016 ssize_t adjust; 1017 struct sockaddr_in dst, src; 1018 union sockaddr_union *su_dst, *su_src; 1019 1020 NET_ASSERT_LOCKED(); 1021 1022 icp = (struct icmp *)((caddr_t) ip - offsetof(struct icmp, icmp_ip)); 1023 mtu = ntohs(icp->icmp_nextmtu); 1024 1025 /* 1026 * Ignore the packet, if we do not receive a MTU 1027 * or the MTU is too small to be acceptable. 1028 */ 1029 if (mtu < 296) 1030 return; 1031 1032 memset(&dst, 0, sizeof(dst)); 1033 dst.sin_family = AF_INET; 1034 dst.sin_len = sizeof(struct sockaddr_in); 1035 dst.sin_addr.s_addr = ip->ip_dst.s_addr; 1036 su_dst = (union sockaddr_union *)&dst; 1037 memset(&src, 0, sizeof(src)); 1038 src.sin_family = AF_INET; 1039 src.sin_len = sizeof(struct sockaddr_in); 1040 src.sin_addr.s_addr = ip->ip_src.s_addr; 1041 su_src = (union sockaddr_union *)&src; 1042 1043 tdbp = gettdbbysrcdst_rev(rdomain, 0, su_src, su_dst, 1044 IPPROTO_ESP); 1045 1046 for (; tdbp != NULL; tdbp = tdbp->tdb_snext) { 1047 if (tdbp->tdb_sproto == IPPROTO_ESP && 1048 ((tdbp->tdb_flags & (TDBF_INVALID|TDBF_UDPENCAP)) == 1049 TDBF_UDPENCAP) && 1050 !memcmp(&tdbp->tdb_dst, &dst, su_dst->sa.sa_len) && 1051 !memcmp(&tdbp->tdb_src, &src, su_src->sa.sa_len)) { 1052 if ((adjust = ipsec_hdrsz(tdbp)) != -1) { 1053 /* Store adjusted MTU in tdb */ 1054 tdbp->tdb_mtu = mtu - adjust; 1055 tdbp->tdb_mtutimeout = gettime() + 1056 ip_mtudisc_timeout; 1057 DPRINTF("spi %08x mtu %d adjust %ld", 1058 ntohl(tdbp->tdb_spi), tdbp->tdb_mtu, 1059 adjust); 1060 } 1061 } 1062 } 1063 } 1064 1065 void 1066 esp4_ctlinput(int cmd, struct sockaddr *sa, u_int rdomain, void *v) 1067 { 1068 if (sa->sa_family != AF_INET || 1069 sa->sa_len != sizeof(struct sockaddr_in)) 1070 return; 1071 1072 ipsec_common_ctlinput(rdomain, cmd, sa, v, IPPROTO_ESP); 1073 } 1074 1075 #ifdef INET6 1076 /* IPv6 AH wrapper. */ 1077 int 1078 ah6_input(struct mbuf **mp, int *offp, int proto, int af) 1079 { 1080 int l = 0; 1081 int protoff, nxt; 1082 struct ip6_ext ip6e; 1083 1084 if ( 1085 #if NPF > 0 1086 ((*mp)->m_pkthdr.pf.flags & PF_TAG_DIVERTED) || 1087 #endif 1088 !ah_enable) 1089 return rip6_input(mp, offp, proto, af); 1090 1091 if (*offp < sizeof(struct ip6_hdr)) { 1092 DPRINTF("bad offset"); 1093 ahstat_inc(ahs_hdrops); 1094 m_freemp(mp); 1095 return IPPROTO_DONE; 1096 } else if (*offp == sizeof(struct ip6_hdr)) { 1097 protoff = offsetof(struct ip6_hdr, ip6_nxt); 1098 } else { 1099 /* Chase down the header chain... */ 1100 protoff = sizeof(struct ip6_hdr); 1101 nxt = (mtod(*mp, struct ip6_hdr *))->ip6_nxt; 1102 1103 do { 1104 protoff += l; 1105 m_copydata(*mp, protoff, sizeof(ip6e), 1106 (caddr_t) &ip6e); 1107 1108 if (nxt == IPPROTO_AH) 1109 l = (ip6e.ip6e_len + 2) << 2; 1110 else 1111 l = (ip6e.ip6e_len + 1) << 3; 1112 #ifdef DIAGNOSTIC 1113 if (l <= 0) 1114 panic("ah6_input: l went zero or negative"); 1115 #endif 1116 1117 nxt = ip6e.ip6e_nxt; 1118 } while (protoff + l < *offp); 1119 1120 /* Malformed packet check */ 1121 if (protoff + l != *offp) { 1122 DPRINTF("bad packet header chain"); 1123 ahstat_inc(ahs_hdrops); 1124 m_freemp(mp); 1125 return IPPROTO_DONE; 1126 } 1127 protoff += offsetof(struct ip6_ext, ip6e_nxt); 1128 } 1129 ipsec_common_input(*mp, *offp, protoff, AF_INET6, proto, 0); 1130 return IPPROTO_DONE; 1131 } 1132 1133 /* IPv6 ESP wrapper. */ 1134 int 1135 esp6_input(struct mbuf **mp, int *offp, int proto, int af) 1136 { 1137 int l = 0; 1138 int protoff, nxt; 1139 struct ip6_ext ip6e; 1140 1141 if ( 1142 #if NPF > 0 1143 ((*mp)->m_pkthdr.pf.flags & PF_TAG_DIVERTED) || 1144 #endif 1145 !esp_enable) 1146 return rip6_input(mp, offp, proto, af); 1147 1148 if (*offp < sizeof(struct ip6_hdr)) { 1149 DPRINTF("bad offset"); 1150 espstat_inc(esps_hdrops); 1151 m_freemp(mp); 1152 return IPPROTO_DONE; 1153 } else if (*offp == sizeof(struct ip6_hdr)) { 1154 protoff = offsetof(struct ip6_hdr, ip6_nxt); 1155 } else { 1156 /* Chase down the header chain... */ 1157 protoff = sizeof(struct ip6_hdr); 1158 nxt = (mtod(*mp, struct ip6_hdr *))->ip6_nxt; 1159 1160 do { 1161 protoff += l; 1162 m_copydata(*mp, protoff, sizeof(ip6e), 1163 (caddr_t) &ip6e); 1164 1165 if (nxt == IPPROTO_AH) 1166 l = (ip6e.ip6e_len + 2) << 2; 1167 else 1168 l = (ip6e.ip6e_len + 1) << 3; 1169 #ifdef DIAGNOSTIC 1170 if (l <= 0) 1171 panic("esp6_input: l went zero or negative"); 1172 #endif 1173 1174 nxt = ip6e.ip6e_nxt; 1175 } while (protoff + l < *offp); 1176 1177 /* Malformed packet check */ 1178 if (protoff + l != *offp) { 1179 DPRINTF("bad packet header chain"); 1180 espstat_inc(esps_hdrops); 1181 m_freemp(mp); 1182 return IPPROTO_DONE; 1183 } 1184 protoff += offsetof(struct ip6_ext, ip6e_nxt); 1185 } 1186 ipsec_common_input(*mp, *offp, protoff, AF_INET6, proto, 0); 1187 return IPPROTO_DONE; 1188 1189 } 1190 1191 /* IPv6 IPcomp wrapper */ 1192 int 1193 ipcomp6_input(struct mbuf **mp, int *offp, int proto, int af) 1194 { 1195 int l = 0; 1196 int protoff, nxt; 1197 struct ip6_ext ip6e; 1198 1199 if ( 1200 #if NPF > 0 1201 ((*mp)->m_pkthdr.pf.flags & PF_TAG_DIVERTED) || 1202 #endif 1203 !ipcomp_enable) 1204 return rip6_input(mp, offp, proto, af); 1205 1206 if (*offp < sizeof(struct ip6_hdr)) { 1207 DPRINTF("bad offset"); 1208 ipcompstat_inc(ipcomps_hdrops); 1209 m_freemp(mp); 1210 return IPPROTO_DONE; 1211 } else if (*offp == sizeof(struct ip6_hdr)) { 1212 protoff = offsetof(struct ip6_hdr, ip6_nxt); 1213 } else { 1214 /* Chase down the header chain... */ 1215 protoff = sizeof(struct ip6_hdr); 1216 nxt = (mtod(*mp, struct ip6_hdr *))->ip6_nxt; 1217 1218 do { 1219 protoff += l; 1220 m_copydata(*mp, protoff, sizeof(ip6e), 1221 (caddr_t) &ip6e); 1222 if (nxt == IPPROTO_AH) 1223 l = (ip6e.ip6e_len + 2) << 2; 1224 else 1225 l = (ip6e.ip6e_len + 1) << 3; 1226 #ifdef DIAGNOSTIC 1227 if (l <= 0) 1228 panic("l went zero or negative"); 1229 #endif 1230 1231 nxt = ip6e.ip6e_nxt; 1232 } while (protoff + l < *offp); 1233 1234 /* Malformed packet check */ 1235 if (protoff + l != *offp) { 1236 DPRINTF("bad packet header chain"); 1237 ipcompstat_inc(ipcomps_hdrops); 1238 m_freemp(mp); 1239 return IPPROTO_DONE; 1240 } 1241 1242 protoff += offsetof(struct ip6_ext, ip6e_nxt); 1243 } 1244 ipsec_common_input(*mp, *offp, protoff, AF_INET6, proto, 0); 1245 return IPPROTO_DONE; 1246 } 1247 #endif /* INET6 */ 1248 1249 int 1250 ipsec_forward_check(struct mbuf *m, int hlen, int af) 1251 { 1252 struct tdb *tdb; 1253 struct tdb_ident *tdbi; 1254 struct m_tag *mtag; 1255 int error = 0; 1256 1257 /* 1258 * IPsec policy check for forwarded packets. Look at 1259 * inner-most IPsec SA used. 1260 */ 1261 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL); 1262 if (mtag != NULL) { 1263 tdbi = (struct tdb_ident *)(mtag + 1); 1264 tdb = gettdb(tdbi->rdomain, tdbi->spi, &tdbi->dst, tdbi->proto); 1265 } else 1266 tdb = NULL; 1267 ipsp_spd_lookup(m, af, hlen, &error, IPSP_DIRECTION_IN, tdb, NULL, 0); 1268 1269 return error; 1270 } 1271 1272 int 1273 ipsec_local_check(struct mbuf *m, int hlen, int proto, int af) 1274 { 1275 struct tdb *tdb; 1276 struct tdb_ident *tdbi; 1277 struct m_tag *mtag; 1278 int error = 0; 1279 1280 /* 1281 * If it's a protected packet for us, skip the policy check. 1282 * That's because we really only care about the properties of 1283 * the protected packet, and not the intermediate versions. 1284 * While this is not the most paranoid setting, it allows 1285 * some flexibility in handling nested tunnels (in setting up 1286 * the policies). 1287 */ 1288 if ((proto == IPPROTO_ESP) || (proto == IPPROTO_AH) || 1289 (proto == IPPROTO_IPCOMP)) 1290 return 0; 1291 1292 /* 1293 * If the protected packet was tunneled, then we need to 1294 * verify the protected packet's information, not the 1295 * external headers. Thus, skip the policy lookup for the 1296 * external packet, and keep the IPsec information linked on 1297 * the packet header (the encapsulation routines know how 1298 * to deal with that). 1299 */ 1300 if ((proto == IPPROTO_IPV4) || (proto == IPPROTO_IPV6)) 1301 return 0; 1302 1303 /* 1304 * When processing IPv6 header chains, do not look at the 1305 * outer header. The inner protocol is relevant and will 1306 * be checked by the local delivery loop later. 1307 */ 1308 if ((af == AF_INET6) && ((proto == IPPROTO_DSTOPTS) || 1309 (proto == IPPROTO_ROUTING) || (proto == IPPROTO_FRAGMENT))) 1310 return 0; 1311 1312 /* 1313 * If the protected packet is TCP or UDP, we'll do the 1314 * policy check in the respective input routine, so we can 1315 * check for bypass sockets. 1316 */ 1317 if ((proto == IPPROTO_TCP) || (proto == IPPROTO_UDP)) 1318 return 0; 1319 1320 /* 1321 * IPsec policy check for local-delivery packets. Look at the 1322 * inner-most SA that protected the packet. This is in fact 1323 * a bit too restrictive (it could end up causing packets to 1324 * be dropped that semantically follow the policy, e.g., in 1325 * certain SA-bundle configurations); but the alternative is 1326 * very complicated (and requires keeping track of what 1327 * kinds of tunneling headers have been seen in-between the 1328 * IPsec headers), and I don't think we lose much functionality 1329 * that's needed in the real world (who uses bundles anyway ?). 1330 */ 1331 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL); 1332 if (mtag) { 1333 tdbi = (struct tdb_ident *)(mtag + 1); 1334 tdb = gettdb(tdbi->rdomain, tdbi->spi, &tdbi->dst, 1335 tdbi->proto); 1336 } else 1337 tdb = NULL; 1338 ipsp_spd_lookup(m, af, hlen, &error, IPSP_DIRECTION_IN, 1339 tdb, NULL, 0); 1340 1341 return error; 1342 } 1343