1 /* $OpenBSD: ipsec_input.c,v 1.197 2021/12/08 14:24:18 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 **mp, 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 struct mbuf *m = *mp; 192 union sockaddr_union dst_address; 193 struct tdb *tdbp = NULL; 194 struct ifnet *encif; 195 u_int32_t spi; 196 u_int16_t cpi; 197 int prot; 198 #ifdef ENCDEBUG 199 char buf[INET6_ADDRSTRLEN]; 200 #endif 201 202 NET_ASSERT_LOCKED(); 203 204 ipsecstat_pkt(ipsec_ipackets, ipsec_ibytes, m->m_pkthdr.len); 205 IPSEC_ISTAT(esps_input, ahs_input, ipcomps_input); 206 207 if ((sproto == IPPROTO_IPCOMP) && (m->m_flags & M_COMP)) { 208 DPRINTF("repeated decompression"); 209 ipcompstat_inc(ipcomps_pdrops); 210 goto drop; 211 } 212 213 if (m->m_pkthdr.len - skip < 2 * sizeof(u_int32_t)) { 214 DPRINTF("packet too small"); 215 IPSEC_ISTAT(esps_hdrops, ahs_hdrops, ipcomps_hdrops); 216 goto drop; 217 } 218 219 /* Retrieve the SPI from the relevant IPsec header */ 220 switch (sproto) { 221 case IPPROTO_ESP: 222 m_copydata(m, skip, sizeof(u_int32_t), (caddr_t) &spi); 223 break; 224 case IPPROTO_AH: 225 m_copydata(m, skip + sizeof(u_int32_t), sizeof(u_int32_t), 226 (caddr_t) &spi); 227 break; 228 case IPPROTO_IPCOMP: 229 m_copydata(m, skip + sizeof(u_int16_t), sizeof(u_int16_t), 230 (caddr_t) &cpi); 231 spi = ntohl(htons(cpi)); 232 break; 233 default: 234 panic("%s: unknown/unsupported security protocol %d", 235 __func__, sproto); 236 } 237 238 /* 239 * Find tunnel control block and (indirectly) call the appropriate 240 * kernel crypto routine. The resulting mbuf chain is a valid 241 * IP packet ready to go through input processing. 242 */ 243 244 memset(&dst_address, 0, sizeof(dst_address)); 245 dst_address.sa.sa_family = af; 246 247 switch (af) { 248 case AF_INET: 249 dst_address.sin.sin_len = sizeof(struct sockaddr_in); 250 m_copydata(m, offsetof(struct ip, ip_dst), 251 sizeof(struct in_addr), 252 (caddr_t) &(dst_address.sin.sin_addr)); 253 break; 254 255 #ifdef INET6 256 case AF_INET6: 257 dst_address.sin6.sin6_len = sizeof(struct sockaddr_in6); 258 m_copydata(m, offsetof(struct ip6_hdr, ip6_dst), 259 sizeof(struct in6_addr), 260 (caddr_t) &(dst_address.sin6.sin6_addr)); 261 in6_recoverscope(&dst_address.sin6, 262 &dst_address.sin6.sin6_addr); 263 break; 264 #endif /* INET6 */ 265 266 default: 267 DPRINTF("unsupported protocol family %d", af); 268 IPSEC_ISTAT(esps_nopf, ahs_nopf, ipcomps_nopf); 269 goto drop; 270 } 271 272 tdbp = gettdb(rtable_l2(m->m_pkthdr.ph_rtableid), 273 spi, &dst_address, sproto); 274 if (tdbp == NULL) { 275 DPRINTF("could not find SA for packet to %s, spi %08x", 276 ipsp_address(&dst_address, buf, sizeof(buf)), ntohl(spi)); 277 IPSEC_ISTAT(esps_notdb, ahs_notdb, ipcomps_notdb); 278 goto drop; 279 } 280 281 if (tdbp->tdb_flags & TDBF_INVALID) { 282 DPRINTF("attempted to use invalid SA %s/%08x/%u", 283 ipsp_address(&dst_address, buf, sizeof(buf)), 284 ntohl(spi), tdbp->tdb_sproto); 285 IPSEC_ISTAT(esps_invalid, ahs_invalid, ipcomps_invalid); 286 goto drop; 287 } 288 289 if (udpencap && !(tdbp->tdb_flags & TDBF_UDPENCAP)) { 290 DPRINTF("attempted to use non-udpencap SA %s/%08x/%u", 291 ipsp_address(&dst_address, buf, sizeof(buf)), 292 ntohl(spi), tdbp->tdb_sproto); 293 espstat_inc(esps_udpinval); 294 goto drop; 295 } 296 297 if (!udpencap && (tdbp->tdb_flags & TDBF_UDPENCAP)) { 298 DPRINTF("attempted to use udpencap SA %s/%08x/%u", 299 ipsp_address(&dst_address, buf, sizeof(buf)), 300 ntohl(spi), tdbp->tdb_sproto); 301 espstat_inc(esps_udpneeded); 302 goto drop; 303 } 304 305 if (tdbp->tdb_xform == NULL) { 306 DPRINTF("attempted to use uninitialized SA %s/%08x/%u", 307 ipsp_address(&dst_address, buf, sizeof(buf)), 308 ntohl(spi), tdbp->tdb_sproto); 309 IPSEC_ISTAT(esps_noxform, ahs_noxform, ipcomps_noxform); 310 goto drop; 311 } 312 313 if (sproto != IPPROTO_IPCOMP) { 314 encif = enc_getif(tdbp->tdb_rdomain_post, tdbp->tdb_tap); 315 if (encif == NULL) { 316 DPRINTF("no enc%u interface for SA %s/%08x/%u", 317 tdbp->tdb_tap, 318 ipsp_address(&dst_address, buf, sizeof(buf)), 319 ntohl(spi), tdbp->tdb_sproto); 320 IPSEC_ISTAT(esps_pdrops, ahs_pdrops, ipcomps_pdrops); 321 goto drop; 322 } 323 324 /* XXX This conflicts with the scoped nature of IPv6 */ 325 m->m_pkthdr.ph_ifidx = encif->if_index; 326 } 327 328 /* Register first use, setup expiration timer. */ 329 if (tdbp->tdb_first_use == 0) { 330 tdbp->tdb_first_use = gettime(); 331 if (tdbp->tdb_flags & TDBF_FIRSTUSE) { 332 if (timeout_add_sec(&tdbp->tdb_first_tmo, 333 tdbp->tdb_exp_first_use)) 334 tdb_ref(tdbp); 335 } 336 if (tdbp->tdb_flags & TDBF_SOFT_FIRSTUSE) { 337 if (timeout_add_sec(&tdbp->tdb_sfirst_tmo, 338 tdbp->tdb_soft_first_use)) 339 tdb_ref(tdbp); 340 } 341 } 342 343 tdbp->tdb_ipackets++; 344 tdbp->tdb_ibytes += m->m_pkthdr.len; 345 346 /* 347 * Call appropriate transform and return -- callback takes care of 348 * everything else. 349 */ 350 prot = (*(tdbp->tdb_xform->xf_input))(mp, tdbp, skip, protoff); 351 if (prot == IPPROTO_DONE) { 352 ipsecstat_inc(ipsec_idrops); 353 tdbp->tdb_idrops++; 354 } 355 tdb_unref(tdbp); 356 return prot; 357 358 drop: 359 m_freemp(mp); 360 ipsecstat_inc(ipsec_idrops); 361 if (tdbp != NULL) 362 tdbp->tdb_idrops++; 363 tdb_unref(tdbp); 364 return IPPROTO_DONE; 365 } 366 367 /* 368 * IPsec input callback, called by the transform callback. Takes care of 369 * filtering and other sanity checks on the processed packet. 370 */ 371 int 372 ipsec_common_input_cb(struct mbuf **mp, struct tdb *tdbp, int skip, int protoff) 373 { 374 struct mbuf *m = *mp; 375 int af, sproto; 376 u_int8_t prot; 377 #if NBPFILTER > 0 378 struct ifnet *encif; 379 #endif 380 struct ip *ip; 381 #ifdef INET6 382 struct ip6_hdr *ip6; 383 #endif /* INET6 */ 384 struct m_tag *mtag; 385 struct tdb_ident *tdbi; 386 #ifdef ENCDEBUG 387 char buf[INET6_ADDRSTRLEN]; 388 #endif 389 390 af = tdbp->tdb_dst.sa.sa_family; 391 sproto = tdbp->tdb_sproto; 392 393 tdbp->tdb_last_used = gettime(); 394 395 /* Fix IPv4 header */ 396 if (af == AF_INET) { 397 if (m->m_len < skip && 398 (m = *mp = m_pullup(m, skip)) == NULL) { 399 DPRINTF("processing failed for SA %s/%08x", 400 ipsp_address(&tdbp->tdb_dst, buf, sizeof(buf)), 401 ntohl(tdbp->tdb_spi)); 402 IPSEC_ISTAT(esps_hdrops, ahs_hdrops, ipcomps_hdrops); 403 goto baddone; 404 } 405 406 ip = mtod(m, struct ip *); 407 ip->ip_len = htons(m->m_pkthdr.len); 408 ip->ip_sum = 0; 409 ip->ip_sum = in_cksum(m, ip->ip_hl << 2); 410 prot = ip->ip_p; 411 } 412 413 #ifdef INET6 414 /* Fix IPv6 header */ 415 if (af == AF_INET6) { 416 if (m->m_len < sizeof(struct ip6_hdr) && 417 (m = *mp = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 418 419 DPRINTF("processing failed for SA %s/%08x", 420 ipsp_address(&tdbp->tdb_dst, buf, sizeof(buf)), 421 ntohl(tdbp->tdb_spi)); 422 IPSEC_ISTAT(esps_hdrops, ahs_hdrops, ipcomps_hdrops); 423 goto baddone; 424 } 425 426 ip6 = mtod(m, struct ip6_hdr *); 427 ip6->ip6_plen = htons(m->m_pkthdr.len - skip); 428 429 /* Save protocol */ 430 m_copydata(m, protoff, 1, (caddr_t) &prot); 431 } 432 #endif /* INET6 */ 433 434 /* 435 * Fix TCP/UDP checksum of UDP encapsulated transport mode ESP packet. 436 * (RFC3948 3.1.2) 437 */ 438 if ((af == AF_INET || af == AF_INET6) && 439 (tdbp->tdb_flags & TDBF_UDPENCAP) && 440 (tdbp->tdb_flags & TDBF_TUNNELING) == 0) { 441 u_int16_t cksum; 442 443 switch (prot) { 444 case IPPROTO_UDP: 445 if (m->m_pkthdr.len < skip + sizeof(struct udphdr)) { 446 IPSEC_ISTAT(esps_hdrops, ahs_hdrops, 447 ipcomps_hdrops); 448 goto baddone; 449 } 450 cksum = 0; 451 m_copyback(m, skip + offsetof(struct udphdr, uh_sum), 452 sizeof(cksum), &cksum, M_NOWAIT); 453 #ifdef INET6 454 if (af == AF_INET6) { 455 cksum = in6_cksum(m, IPPROTO_UDP, skip, 456 m->m_pkthdr.len - skip); 457 m_copyback(m, skip + offsetof(struct udphdr, 458 uh_sum), sizeof(cksum), &cksum, M_NOWAIT); 459 } 460 #endif 461 break; 462 case IPPROTO_TCP: 463 if (m->m_pkthdr.len < skip + sizeof(struct tcphdr)) { 464 IPSEC_ISTAT(esps_hdrops, ahs_hdrops, 465 ipcomps_hdrops); 466 goto baddone; 467 } 468 cksum = 0; 469 m_copyback(m, skip + offsetof(struct tcphdr, th_sum), 470 sizeof(cksum), &cksum, M_NOWAIT); 471 if (af == AF_INET) 472 cksum = in4_cksum(m, IPPROTO_TCP, skip, 473 m->m_pkthdr.len - skip); 474 #ifdef INET6 475 else if (af == AF_INET6) 476 cksum = in6_cksum(m, IPPROTO_TCP, skip, 477 m->m_pkthdr.len - skip); 478 #endif 479 m_copyback(m, skip + offsetof(struct tcphdr, th_sum), 480 sizeof(cksum), &cksum, M_NOWAIT); 481 break; 482 } 483 } 484 485 /* 486 * Record what we've done to the packet (under what SA it was 487 * processed). 488 */ 489 if (tdbp->tdb_sproto != IPPROTO_IPCOMP) { 490 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE, 491 sizeof(struct tdb_ident), M_NOWAIT); 492 if (mtag == NULL) { 493 DPRINTF("failed to get tag"); 494 IPSEC_ISTAT(esps_hdrops, ahs_hdrops, ipcomps_hdrops); 495 goto baddone; 496 } 497 498 tdbi = (struct tdb_ident *)(mtag + 1); 499 tdbi->dst = tdbp->tdb_dst; 500 tdbi->proto = tdbp->tdb_sproto; 501 tdbi->spi = tdbp->tdb_spi; 502 tdbi->rdomain = tdbp->tdb_rdomain; 503 504 m_tag_prepend(m, mtag); 505 } 506 507 switch (sproto) { 508 case IPPROTO_ESP: 509 /* Packet is confidential ? */ 510 if (tdbp->tdb_encalgxform) 511 m->m_flags |= M_CONF; 512 513 /* Check if we had authenticated ESP. */ 514 if (tdbp->tdb_authalgxform) 515 m->m_flags |= M_AUTH; 516 break; 517 case IPPROTO_AH: 518 m->m_flags |= M_AUTH; 519 break; 520 case IPPROTO_IPCOMP: 521 m->m_flags |= M_COMP; 522 break; 523 default: 524 panic("%s: unknown/unsupported security protocol %d", 525 __func__, sproto); 526 } 527 528 #if NPF > 0 529 /* Add pf tag if requested. */ 530 pf_tag_packet(m, tdbp->tdb_tag, -1); 531 pf_pkt_addr_changed(m); 532 #endif 533 if (tdbp->tdb_rdomain != tdbp->tdb_rdomain_post) 534 m->m_pkthdr.ph_rtableid = tdbp->tdb_rdomain_post; 535 536 if (tdbp->tdb_flags & TDBF_TUNNELING) 537 m->m_flags |= M_TUNNEL; 538 539 ipsecstat_add(ipsec_idecompbytes, m->m_pkthdr.len); 540 tdbp->tdb_idecompbytes += m->m_pkthdr.len; 541 542 #if NBPFILTER > 0 543 encif = enc_getif(tdbp->tdb_rdomain_post, tdbp->tdb_tap); 544 if (encif != NULL) { 545 encif->if_ipackets++; 546 encif->if_ibytes += m->m_pkthdr.len; 547 548 if (encif->if_bpf) { 549 struct enchdr hdr; 550 551 hdr.af = af; 552 hdr.spi = tdbp->tdb_spi; 553 hdr.flags = m->m_flags & (M_AUTH|M_CONF); 554 555 bpf_mtap_hdr(encif->if_bpf, (char *)&hdr, 556 ENC_HDRLEN, m, BPF_DIRECTION_IN); 557 } 558 } 559 #endif 560 561 #if NPF > 0 562 /* 563 * The ip_deliver() shortcut avoids running through ip_input() with the 564 * same IP header twice. Packets in transport mode have to be be 565 * passed to pf explicitly. In tunnel mode the inner IP header will 566 * run through ip_input() and pf anyway. 567 */ 568 if ((tdbp->tdb_flags & TDBF_TUNNELING) == 0) { 569 struct ifnet *ifp; 570 571 /* This is the enc0 interface unless for ipcomp. */ 572 if ((ifp = if_get(m->m_pkthdr.ph_ifidx)) == NULL) { 573 goto baddone; 574 } 575 if (pf_test(af, PF_IN, ifp, mp) != PF_PASS) { 576 if_put(ifp); 577 goto baddone; 578 } 579 m = *mp; 580 if_put(ifp); 581 if (m == NULL) 582 return IPPROTO_DONE; 583 } 584 #endif 585 /* Return to the appropriate protocol handler in deliver loop. */ 586 return prot; 587 588 baddone: 589 m_freemp(mp); 590 return IPPROTO_DONE; 591 #undef IPSEC_ISTAT 592 } 593 594 int 595 ipsec_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp, 596 size_t newlen) 597 { 598 int error; 599 600 switch (name[0]) { 601 case IPCTL_IPSEC_ENC_ALGORITHM: 602 NET_LOCK(); 603 error = sysctl_tstring(oldp, oldlenp, newp, newlen, 604 ipsec_def_enc, sizeof(ipsec_def_enc)); 605 NET_UNLOCK(); 606 return (error); 607 case IPCTL_IPSEC_AUTH_ALGORITHM: 608 NET_LOCK(); 609 error = sysctl_tstring(oldp, oldlenp, newp, newlen, 610 ipsec_def_auth, sizeof(ipsec_def_auth)); 611 NET_UNLOCK(); 612 return (error); 613 case IPCTL_IPSEC_IPCOMP_ALGORITHM: 614 NET_LOCK(); 615 error = sysctl_tstring(oldp, oldlenp, newp, newlen, 616 ipsec_def_comp, sizeof(ipsec_def_comp)); 617 NET_UNLOCK(); 618 return (error); 619 case IPCTL_IPSEC_STATS: 620 return (ipsec_sysctl_ipsecstat(oldp, oldlenp, newp)); 621 default: 622 NET_LOCK(); 623 error = sysctl_bounded_arr(ipsecctl_vars, nitems(ipsecctl_vars), 624 name, namelen, oldp, oldlenp, newp, newlen); 625 NET_UNLOCK(); 626 return (error); 627 } 628 } 629 630 int 631 esp_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp, 632 size_t newlen) 633 { 634 int error; 635 636 /* All sysctl names at this level are terminal. */ 637 if (namelen != 1) 638 return (ENOTDIR); 639 640 switch (name[0]) { 641 case ESPCTL_STATS: 642 return (esp_sysctl_espstat(oldp, oldlenp, newp)); 643 default: 644 NET_LOCK(); 645 error = sysctl_bounded_arr(espctl_vars, nitems(espctl_vars), 646 name, namelen, oldp, oldlenp, newp, newlen); 647 NET_UNLOCK(); 648 return (error); 649 } 650 } 651 652 int 653 esp_sysctl_espstat(void *oldp, size_t *oldlenp, void *newp) 654 { 655 struct espstat espstat; 656 657 CTASSERT(sizeof(espstat) == (esps_ncounters * sizeof(uint64_t))); 658 memset(&espstat, 0, sizeof espstat); 659 counters_read(espcounters, (uint64_t *)&espstat, esps_ncounters); 660 return (sysctl_rdstruct(oldp, oldlenp, newp, &espstat, 661 sizeof(espstat))); 662 } 663 664 int 665 ah_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp, 666 size_t newlen) 667 { 668 int error; 669 670 /* All sysctl names at this level are terminal. */ 671 if (namelen != 1) 672 return (ENOTDIR); 673 674 switch (name[0]) { 675 case AHCTL_STATS: 676 return ah_sysctl_ahstat(oldp, oldlenp, newp); 677 default: 678 NET_LOCK(); 679 error = sysctl_bounded_arr(ahctl_vars, nitems(ahctl_vars), name, 680 namelen, oldp, oldlenp, newp, newlen); 681 NET_UNLOCK(); 682 return (error); 683 } 684 } 685 686 int 687 ah_sysctl_ahstat(void *oldp, size_t *oldlenp, void *newp) 688 { 689 struct ahstat ahstat; 690 691 CTASSERT(sizeof(ahstat) == (ahs_ncounters * sizeof(uint64_t))); 692 memset(&ahstat, 0, sizeof ahstat); 693 counters_read(ahcounters, (uint64_t *)&ahstat, ahs_ncounters); 694 return (sysctl_rdstruct(oldp, oldlenp, newp, &ahstat, sizeof(ahstat))); 695 } 696 697 int 698 ipcomp_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp, 699 size_t newlen) 700 { 701 int error; 702 703 /* All sysctl names at this level are terminal. */ 704 if (namelen != 1) 705 return (ENOTDIR); 706 707 switch (name[0]) { 708 case IPCOMPCTL_STATS: 709 return ipcomp_sysctl_ipcompstat(oldp, oldlenp, newp); 710 default: 711 NET_LOCK(); 712 error = sysctl_bounded_arr(ipcompctl_vars, 713 nitems(ipcompctl_vars), name, namelen, oldp, oldlenp, 714 newp, newlen); 715 NET_UNLOCK(); 716 return (error); 717 } 718 } 719 720 int 721 ipcomp_sysctl_ipcompstat(void *oldp, size_t *oldlenp, void *newp) 722 { 723 struct ipcompstat ipcompstat; 724 725 CTASSERT(sizeof(ipcompstat) == (ipcomps_ncounters * sizeof(uint64_t))); 726 memset(&ipcompstat, 0, sizeof ipcompstat); 727 counters_read(ipcompcounters, (uint64_t *)&ipcompstat, 728 ipcomps_ncounters); 729 return (sysctl_rdstruct(oldp, oldlenp, newp, &ipcompstat, 730 sizeof(ipcompstat))); 731 } 732 733 int 734 ipsec_sysctl_ipsecstat(void *oldp, size_t *oldlenp, void *newp) 735 { 736 struct ipsecstat ipsecstat; 737 738 CTASSERT(sizeof(ipsecstat) == (ipsec_ncounters * sizeof(uint64_t))); 739 memset(&ipsecstat, 0, sizeof ipsecstat); 740 counters_read(ipseccounters, (uint64_t *)&ipsecstat, ipsec_ncounters); 741 return (sysctl_rdstruct(oldp, oldlenp, newp, &ipsecstat, 742 sizeof(ipsecstat))); 743 } 744 745 int 746 ipsec_input_disabled(struct mbuf **mp, int *offp, int proto, int af) 747 { 748 switch (af) { 749 case AF_INET: 750 return rip_input(mp, offp, proto, af); 751 #ifdef INET6 752 case AF_INET6: 753 return rip6_input(mp, offp, proto, af); 754 #endif 755 default: 756 unhandled_af(af); 757 } 758 } 759 760 int 761 ah46_input(struct mbuf **mp, int *offp, int proto, int af) 762 { 763 int protoff; 764 765 if ( 766 #if NPF > 0 767 ((*mp)->m_pkthdr.pf.flags & PF_TAG_DIVERTED) || 768 #endif 769 !ah_enable) 770 return ipsec_input_disabled(mp, offp, proto, af); 771 772 protoff = ipsec_protoff(*mp, *offp, af); 773 if (protoff < 0) { 774 DPRINTF("bad packet header chain"); 775 ahstat_inc(ahs_hdrops); 776 m_freemp(mp); 777 return IPPROTO_DONE; 778 } 779 780 return ipsec_common_input(mp, *offp, protoff, af, proto, 0); 781 } 782 783 void 784 ah4_ctlinput(int cmd, struct sockaddr *sa, u_int rdomain, void *v) 785 { 786 if (sa->sa_family != AF_INET || 787 sa->sa_len != sizeof(struct sockaddr_in)) 788 return; 789 790 ipsec_common_ctlinput(rdomain, cmd, sa, v, IPPROTO_AH); 791 } 792 793 int 794 esp46_input(struct mbuf **mp, int *offp, int proto, int af) 795 { 796 int protoff; 797 798 if ( 799 #if NPF > 0 800 ((*mp)->m_pkthdr.pf.flags & PF_TAG_DIVERTED) || 801 #endif 802 !esp_enable) 803 return ipsec_input_disabled(mp, offp, proto, af); 804 805 protoff = ipsec_protoff(*mp, *offp, af); 806 if (protoff < 0) { 807 DPRINTF("bad packet header chain"); 808 espstat_inc(esps_hdrops); 809 m_freemp(mp); 810 return IPPROTO_DONE; 811 } 812 813 return ipsec_common_input(mp, *offp, protoff, af, proto, 0); 814 } 815 816 /* IPv4 IPCOMP wrapper */ 817 int 818 ipcomp46_input(struct mbuf **mp, int *offp, int proto, int af) 819 { 820 int protoff; 821 822 if ( 823 #if NPF > 0 824 ((*mp)->m_pkthdr.pf.flags & PF_TAG_DIVERTED) || 825 #endif 826 !ipcomp_enable) 827 return ipsec_input_disabled(mp, offp, proto, af); 828 829 protoff = ipsec_protoff(*mp, *offp, af); 830 if (protoff < 0) { 831 DPRINTF("bad packet header chain"); 832 ipcompstat_inc(ipcomps_hdrops); 833 m_freemp(mp); 834 return IPPROTO_DONE; 835 } 836 837 return ipsec_common_input(mp, *offp, protoff, af, proto, 0); 838 } 839 840 void 841 ipsec_set_mtu(struct tdb *tdbp, u_int32_t mtu) 842 { 843 ssize_t adjust; 844 845 NET_ASSERT_LOCKED(); 846 847 /* Walk the chain backwards to the first tdb */ 848 for (; tdbp != NULL; tdbp = tdbp->tdb_inext) { 849 if (tdbp->tdb_flags & TDBF_INVALID || 850 (adjust = ipsec_hdrsz(tdbp)) == -1) 851 return; 852 853 mtu -= adjust; 854 855 /* Store adjusted MTU in tdb */ 856 tdbp->tdb_mtu = mtu; 857 tdbp->tdb_mtutimeout = gettime() + ip_mtudisc_timeout; 858 DPRINTF("spi %08x mtu %d adjust %ld", 859 ntohl(tdbp->tdb_spi), tdbp->tdb_mtu, adjust); 860 } 861 } 862 863 void 864 ipsec_common_ctlinput(u_int rdomain, int cmd, struct sockaddr *sa, 865 void *v, int proto) 866 { 867 struct ip *ip = v; 868 869 if (cmd == PRC_MSGSIZE && ip && ip_mtudisc && ip->ip_v == 4) { 870 struct tdb *tdbp; 871 struct sockaddr_in dst; 872 struct icmp *icp; 873 int hlen = ip->ip_hl << 2; 874 u_int32_t spi, mtu; 875 876 /* Find the right MTU. */ 877 icp = (struct icmp *)((caddr_t) ip - 878 offsetof(struct icmp, icmp_ip)); 879 mtu = ntohs(icp->icmp_nextmtu); 880 881 /* 882 * Ignore the packet, if we do not receive a MTU 883 * or the MTU is too small to be acceptable. 884 */ 885 if (mtu < 296) 886 return; 887 888 memset(&dst, 0, sizeof(struct sockaddr_in)); 889 dst.sin_family = AF_INET; 890 dst.sin_len = sizeof(struct sockaddr_in); 891 dst.sin_addr.s_addr = ip->ip_dst.s_addr; 892 893 memcpy(&spi, (caddr_t)ip + hlen, sizeof(u_int32_t)); 894 895 tdbp = gettdb_rev(rdomain, spi, (union sockaddr_union *)&dst, 896 proto); 897 ipsec_set_mtu(tdbp, mtu); 898 tdb_unref(tdbp); 899 } 900 } 901 902 void 903 udpencap_ctlinput(int cmd, struct sockaddr *sa, u_int rdomain, void *v) 904 { 905 struct ip *ip = v; 906 struct tdb *tdbp, *first; 907 struct icmp *icp; 908 u_int32_t mtu; 909 struct sockaddr_in dst, src; 910 union sockaddr_union *su_dst, *su_src; 911 912 NET_ASSERT_LOCKED(); 913 914 icp = (struct icmp *)((caddr_t) ip - offsetof(struct icmp, icmp_ip)); 915 mtu = ntohs(icp->icmp_nextmtu); 916 917 /* 918 * Ignore the packet, if we do not receive a MTU 919 * or the MTU is too small to be acceptable. 920 */ 921 if (mtu < 296) 922 return; 923 924 memset(&dst, 0, sizeof(dst)); 925 dst.sin_family = AF_INET; 926 dst.sin_len = sizeof(struct sockaddr_in); 927 dst.sin_addr.s_addr = ip->ip_dst.s_addr; 928 su_dst = (union sockaddr_union *)&dst; 929 memset(&src, 0, sizeof(src)); 930 src.sin_family = AF_INET; 931 src.sin_len = sizeof(struct sockaddr_in); 932 src.sin_addr.s_addr = ip->ip_src.s_addr; 933 su_src = (union sockaddr_union *)&src; 934 935 first = gettdbbysrcdst_rev(rdomain, 0, su_src, su_dst, IPPROTO_ESP); 936 937 mtx_enter(&tdb_sadb_mtx); 938 for (tdbp = first; tdbp != NULL; tdbp = tdbp->tdb_snext) { 939 if (tdbp->tdb_sproto == IPPROTO_ESP && 940 ((tdbp->tdb_flags & (TDBF_INVALID|TDBF_UDPENCAP)) == 941 TDBF_UDPENCAP) && 942 !memcmp(&tdbp->tdb_dst, &dst, su_dst->sa.sa_len) && 943 !memcmp(&tdbp->tdb_src, &src, su_src->sa.sa_len)) 944 ipsec_set_mtu(tdbp, mtu); 945 } 946 mtx_leave(&tdb_sadb_mtx); 947 tdb_unref(first); 948 } 949 950 void 951 esp4_ctlinput(int cmd, struct sockaddr *sa, u_int rdomain, void *v) 952 { 953 if (sa->sa_family != AF_INET || 954 sa->sa_len != sizeof(struct sockaddr_in)) 955 return; 956 957 ipsec_common_ctlinput(rdomain, cmd, sa, v, IPPROTO_ESP); 958 } 959 960 /* Find the offset of the next protocol field in the previous header. */ 961 int 962 ipsec_protoff(struct mbuf *m, int off, int af) 963 { 964 #ifdef INET6 965 struct ip6_ext ip6e; 966 int protoff, nxt, l; 967 #endif /* INET6 */ 968 969 switch (af) { 970 case AF_INET: 971 return offsetof(struct ip, ip_p); 972 #ifdef INET6 973 case AF_INET6: 974 break; 975 #endif /* INET6 */ 976 default: 977 unhandled_af(af); 978 } 979 980 #ifdef INET6 981 if (off < sizeof(struct ip6_hdr)) 982 return -1; 983 984 if (off == sizeof(struct ip6_hdr)) 985 return offsetof(struct ip6_hdr, ip6_nxt); 986 987 /* Chase down the header chain... */ 988 protoff = sizeof(struct ip6_hdr); 989 nxt = (mtod(m, struct ip6_hdr *))->ip6_nxt; 990 l = 0; 991 992 do { 993 protoff += l; 994 m_copydata(m, protoff, sizeof(ip6e), 995 (caddr_t) &ip6e); 996 997 if (nxt == IPPROTO_AH) 998 l = (ip6e.ip6e_len + 2) << 2; 999 else 1000 l = (ip6e.ip6e_len + 1) << 3; 1001 #ifdef DIAGNOSTIC 1002 if (l <= 0) 1003 panic("ah6_input: l went zero or negative"); 1004 #endif 1005 1006 nxt = ip6e.ip6e_nxt; 1007 } while (protoff + l < off); 1008 1009 /* Malformed packet check */ 1010 if (protoff + l != off) 1011 return -1; 1012 1013 protoff += offsetof(struct ip6_ext, ip6e_nxt); 1014 return protoff; 1015 #endif /* INET6 */ 1016 } 1017 1018 int 1019 ipsec_forward_check(struct mbuf *m, int hlen, int af) 1020 { 1021 struct tdb *tdb; 1022 struct tdb_ident *tdbi; 1023 struct m_tag *mtag; 1024 int error = 0; 1025 1026 /* 1027 * IPsec policy check for forwarded packets. Look at 1028 * inner-most IPsec SA used. 1029 */ 1030 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL); 1031 if (mtag != NULL) { 1032 tdbi = (struct tdb_ident *)(mtag + 1); 1033 tdb = gettdb(tdbi->rdomain, tdbi->spi, &tdbi->dst, tdbi->proto); 1034 } else 1035 tdb = NULL; 1036 error = ipsp_spd_lookup(m, af, hlen, IPSP_DIRECTION_IN, 1037 tdb, NULL, NULL, 0); 1038 tdb_unref(tdb); 1039 1040 return error; 1041 } 1042 1043 int 1044 ipsec_local_check(struct mbuf *m, int hlen, int proto, int af) 1045 { 1046 struct tdb *tdb; 1047 struct tdb_ident *tdbi; 1048 struct m_tag *mtag; 1049 int error = 0; 1050 1051 /* 1052 * If it's a protected packet for us, skip the policy check. 1053 * That's because we really only care about the properties of 1054 * the protected packet, and not the intermediate versions. 1055 * While this is not the most paranoid setting, it allows 1056 * some flexibility in handling nested tunnels (in setting up 1057 * the policies). 1058 */ 1059 if ((proto == IPPROTO_ESP) || (proto == IPPROTO_AH) || 1060 (proto == IPPROTO_IPCOMP)) 1061 return 0; 1062 1063 /* 1064 * If the protected packet was tunneled, then we need to 1065 * verify the protected packet's information, not the 1066 * external headers. Thus, skip the policy lookup for the 1067 * external packet, and keep the IPsec information linked on 1068 * the packet header (the encapsulation routines know how 1069 * to deal with that). 1070 */ 1071 if ((proto == IPPROTO_IPV4) || (proto == IPPROTO_IPV6)) 1072 return 0; 1073 1074 /* 1075 * When processing IPv6 header chains, do not look at the 1076 * outer header. The inner protocol is relevant and will 1077 * be checked by the local delivery loop later. 1078 */ 1079 if ((af == AF_INET6) && ((proto == IPPROTO_DSTOPTS) || 1080 (proto == IPPROTO_ROUTING) || (proto == IPPROTO_FRAGMENT))) 1081 return 0; 1082 1083 /* 1084 * If the protected packet is TCP or UDP, we'll do the 1085 * policy check in the respective input routine, so we can 1086 * check for bypass sockets. 1087 */ 1088 if ((proto == IPPROTO_TCP) || (proto == IPPROTO_UDP)) 1089 return 0; 1090 1091 /* 1092 * IPsec policy check for local-delivery packets. Look at the 1093 * inner-most SA that protected the packet. This is in fact 1094 * a bit too restrictive (it could end up causing packets to 1095 * be dropped that semantically follow the policy, e.g., in 1096 * certain SA-bundle configurations); but the alternative is 1097 * very complicated (and requires keeping track of what 1098 * kinds of tunneling headers have been seen in-between the 1099 * IPsec headers), and I don't think we lose much functionality 1100 * that's needed in the real world (who uses bundles anyway ?). 1101 */ 1102 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL); 1103 if (mtag) { 1104 tdbi = (struct tdb_ident *)(mtag + 1); 1105 tdb = gettdb(tdbi->rdomain, tdbi->spi, &tdbi->dst, 1106 tdbi->proto); 1107 } else 1108 tdb = NULL; 1109 error = ipsp_spd_lookup(m, af, hlen, IPSP_DIRECTION_IN, 1110 tdb, NULL, NULL, 0); 1111 tdb_unref(tdb); 1112 1113 return error; 1114 } 1115