1 /* $OpenBSD: ipsec_input.c,v 1.154 2017/05/28 09:25:51 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 "bpfilter.h" 81 82 void ipsec_common_ctlinput(u_int, int, struct sockaddr *, void *, int); 83 84 #ifdef ENCDEBUG 85 #define DPRINTF(x) if (encdebug) printf x 86 #else 87 #define DPRINTF(x) 88 #endif 89 90 /* sysctl variables */ 91 int esp_enable = 1; 92 int ah_enable = 1; 93 int ipcomp_enable = 0; 94 95 int *espctl_vars[ESPCTL_MAXID] = ESPCTL_VARS; 96 int *ahctl_vars[AHCTL_MAXID] = AHCTL_VARS; 97 int *ipcompctl_vars[IPCOMPCTL_MAXID] = IPCOMPCTL_VARS; 98 99 /* 100 * ipsec_common_input() gets called when we receive an IPsec-protected packet 101 * in IPv4 or IPv6. All it does is find the right TDB and call the appropriate 102 * transform. The callback takes care of further processing (like ingress 103 * filtering). 104 */ 105 int 106 ipsec_common_input(struct mbuf *m, int skip, int protoff, int af, int sproto, 107 int udpencap) 108 { 109 #define IPSEC_ISTAT(x,y,z) (sproto == IPPROTO_ESP ? (x)++ : \ 110 sproto == IPPROTO_AH ? (y)++ : (z)++) 111 112 union sockaddr_union dst_address; 113 struct tdb *tdbp; 114 struct ifnet *encif; 115 u_int32_t spi; 116 u_int16_t cpi; 117 int error; 118 #ifdef ENCDEBUG 119 char buf[INET6_ADDRSTRLEN]; 120 #endif 121 122 NET_ASSERT_LOCKED(); 123 124 IPSEC_ISTAT(espstat.esps_input, ahstat.ahs_input, 125 ipcompstat.ipcomps_input); 126 127 if (m == NULL) { 128 DPRINTF(("ipsec_common_input(): NULL packet received\n")); 129 IPSEC_ISTAT(espstat.esps_hdrops, ahstat.ahs_hdrops, 130 ipcompstat.ipcomps_hdrops); 131 return EINVAL; 132 } 133 134 if ((sproto == IPPROTO_ESP && !esp_enable) || 135 (sproto == IPPROTO_AH && !ah_enable) || 136 #if NPF > 0 137 (m->m_pkthdr.pf.flags & PF_TAG_DIVERTED) || 138 #endif 139 (sproto == IPPROTO_IPCOMP && !ipcomp_enable)) { 140 switch (af) { 141 case AF_INET: 142 rip_input(&m, &skip, sproto, af); 143 break; 144 #ifdef INET6 145 case AF_INET6: 146 rip6_input(&m, &skip, sproto, af); 147 break; 148 #endif /* INET6 */ 149 default: 150 DPRINTF(("ipsec_common_input(): unsupported protocol " 151 "family %d\n", af)); 152 m_freem(m); 153 IPSEC_ISTAT(espstat.esps_nopf, ahstat.ahs_nopf, 154 ipcompstat.ipcomps_nopf); 155 return EPFNOSUPPORT; 156 } 157 return 0; 158 } 159 if ((sproto == IPPROTO_IPCOMP) && (m->m_flags & M_COMP)) { 160 m_freem(m); 161 ipcompstat.ipcomps_pdrops++; 162 DPRINTF(("ipsec_common_input(): repeated decompression\n")); 163 return EINVAL; 164 } 165 166 if (m->m_pkthdr.len - skip < 2 * sizeof(u_int32_t)) { 167 m_freem(m); 168 IPSEC_ISTAT(espstat.esps_hdrops, ahstat.ahs_hdrops, 169 ipcompstat.ipcomps_hdrops); 170 DPRINTF(("ipsec_common_input(): packet too small\n")); 171 return EINVAL; 172 } 173 174 /* Retrieve the SPI from the relevant IPsec header */ 175 switch (sproto) { 176 case IPPROTO_ESP: 177 m_copydata(m, skip, sizeof(u_int32_t), (caddr_t) &spi); 178 break; 179 case IPPROTO_AH: 180 m_copydata(m, skip + sizeof(u_int32_t), sizeof(u_int32_t), 181 (caddr_t) &spi); 182 break; 183 case IPPROTO_IPCOMP: 184 m_copydata(m, skip + sizeof(u_int16_t), sizeof(u_int16_t), 185 (caddr_t) &cpi); 186 spi = ntohl(htons(cpi)); 187 break; 188 default: 189 panic("%s: unknown/unsupported security protocol %d", 190 __func__, sproto); 191 } 192 193 /* 194 * Find tunnel control block and (indirectly) call the appropriate 195 * kernel crypto routine. The resulting mbuf chain is a valid 196 * IP packet ready to go through input processing. 197 */ 198 199 memset(&dst_address, 0, sizeof(dst_address)); 200 dst_address.sa.sa_family = af; 201 202 switch (af) { 203 case AF_INET: 204 dst_address.sin.sin_len = sizeof(struct sockaddr_in); 205 m_copydata(m, offsetof(struct ip, ip_dst), 206 sizeof(struct in_addr), 207 (caddr_t) &(dst_address.sin.sin_addr)); 208 break; 209 210 #ifdef INET6 211 case AF_INET6: 212 dst_address.sin6.sin6_len = sizeof(struct sockaddr_in6); 213 m_copydata(m, offsetof(struct ip6_hdr, ip6_dst), 214 sizeof(struct in6_addr), 215 (caddr_t) &(dst_address.sin6.sin6_addr)); 216 in6_recoverscope(&dst_address.sin6, 217 &dst_address.sin6.sin6_addr); 218 break; 219 #endif /* INET6 */ 220 221 default: 222 DPRINTF(("ipsec_common_input(): unsupported protocol " 223 "family %d\n", af)); 224 m_freem(m); 225 IPSEC_ISTAT(espstat.esps_nopf, ahstat.ahs_nopf, 226 ipcompstat.ipcomps_nopf); 227 return EPFNOSUPPORT; 228 } 229 230 tdbp = gettdb(rtable_l2(m->m_pkthdr.ph_rtableid), 231 spi, &dst_address, sproto); 232 if (tdbp == NULL) { 233 DPRINTF(("ipsec_common_input(): could not find SA for " 234 "packet to %s, spi %08x\n", 235 ipsp_address(&dst_address, buf, sizeof(buf)), ntohl(spi))); 236 m_freem(m); 237 IPSEC_ISTAT(espstat.esps_notdb, ahstat.ahs_notdb, 238 ipcompstat.ipcomps_notdb); 239 return ENOENT; 240 } 241 242 if (tdbp->tdb_flags & TDBF_INVALID) { 243 DPRINTF(("ipsec_common_input(): attempted to use invalid " 244 "SA %s/%08x/%u\n", ipsp_address(&dst_address, buf, 245 sizeof(buf)), ntohl(spi), tdbp->tdb_sproto)); 246 m_freem(m); 247 IPSEC_ISTAT(espstat.esps_invalid, ahstat.ahs_invalid, 248 ipcompstat.ipcomps_invalid); 249 return EINVAL; 250 } 251 252 if (udpencap && !(tdbp->tdb_flags & TDBF_UDPENCAP)) { 253 DPRINTF(("ipsec_common_input(): attempted to use non-udpencap " 254 "SA %s/%08x/%u\n", ipsp_address(&dst_address, buf, 255 sizeof(buf)), ntohl(spi), tdbp->tdb_sproto)); 256 m_freem(m); 257 espstat.esps_udpinval++; 258 return EINVAL; 259 } 260 261 if (!udpencap && (tdbp->tdb_flags & TDBF_UDPENCAP)) { 262 DPRINTF(("ipsec_common_input(): attempted to use udpencap " 263 "SA %s/%08x/%u\n", ipsp_address(&dst_address, buf, 264 sizeof(buf)), ntohl(spi), tdbp->tdb_sproto)); 265 m_freem(m); 266 espstat.esps_udpneeded++; 267 return EINVAL; 268 } 269 270 if (tdbp->tdb_xform == NULL) { 271 DPRINTF(("ipsec_common_input(): attempted to use uninitialized " 272 "SA %s/%08x/%u\n", ipsp_address(&dst_address, buf, 273 sizeof(buf)), ntohl(spi), tdbp->tdb_sproto)); 274 m_freem(m); 275 IPSEC_ISTAT(espstat.esps_noxform, ahstat.ahs_noxform, 276 ipcompstat.ipcomps_noxform); 277 return ENXIO; 278 } 279 280 if (sproto != IPPROTO_IPCOMP) { 281 if ((encif = enc_getif(tdbp->tdb_rdomain, 282 tdbp->tdb_tap)) == NULL) { 283 DPRINTF(("ipsec_common_input(): " 284 "no enc%u interface for SA %s/%08x/%u\n", 285 tdbp->tdb_tap, ipsp_address(&dst_address, buf, 286 sizeof(buf)), ntohl(spi), tdbp->tdb_sproto)); 287 m_freem(m); 288 289 IPSEC_ISTAT(espstat.esps_pdrops, 290 ahstat.ahs_pdrops, 291 ipcompstat.ipcomps_pdrops); 292 return EACCES; 293 } 294 295 /* XXX This conflicts with the scoped nature of IPv6 */ 296 m->m_pkthdr.ph_ifidx = encif->if_index; 297 } 298 299 /* Register first use, setup expiration timer. */ 300 if (tdbp->tdb_first_use == 0) { 301 tdbp->tdb_first_use = time_second; 302 if (tdbp->tdb_flags & TDBF_FIRSTUSE) 303 timeout_add_sec(&tdbp->tdb_first_tmo, 304 tdbp->tdb_exp_first_use); 305 if (tdbp->tdb_flags & TDBF_SOFT_FIRSTUSE) 306 timeout_add_sec(&tdbp->tdb_sfirst_tmo, 307 tdbp->tdb_soft_first_use); 308 } 309 310 /* 311 * Call appropriate transform and return -- callback takes care of 312 * everything else. 313 */ 314 error = (*(tdbp->tdb_xform->xf_input))(m, tdbp, skip, protoff); 315 return error; 316 } 317 318 /* 319 * IPsec input callback, called by the transform callback. Takes care of 320 * filtering and other sanity checks on the processed packet. 321 */ 322 void 323 ipsec_common_input_cb(struct mbuf *m, struct tdb *tdbp, int skip, int protoff) 324 { 325 int af, sproto; 326 u_int8_t prot; 327 328 #if NBPFILTER > 0 329 struct ifnet *encif; 330 #endif 331 332 struct ip *ip, ipn; 333 334 #ifdef INET6 335 struct ip6_hdr *ip6, ip6n; 336 #endif /* INET6 */ 337 struct m_tag *mtag; 338 struct tdb_ident *tdbi; 339 340 #ifdef ENCDEBUG 341 char buf[INET6_ADDRSTRLEN]; 342 #endif 343 344 af = tdbp->tdb_dst.sa.sa_family; 345 sproto = tdbp->tdb_sproto; 346 347 tdbp->tdb_last_used = time_second; 348 349 /* Sanity check */ 350 if (m == NULL) { 351 /* The called routine will print a message if necessary */ 352 IPSEC_ISTAT(espstat.esps_badkcr, ahstat.ahs_badkcr, 353 ipcompstat.ipcomps_badkcr); 354 return; 355 } 356 357 /* Fix IPv4 header */ 358 if (af == AF_INET) { 359 if ((m->m_len < skip) && ((m = m_pullup(m, skip)) == NULL)) { 360 DPRINTF(("ipsec_common_input_cb(): processing failed " 361 "for SA %s/%08x\n", ipsp_address(&tdbp->tdb_dst, 362 buf, sizeof(buf)), ntohl(tdbp->tdb_spi))); 363 IPSEC_ISTAT(espstat.esps_hdrops, ahstat.ahs_hdrops, 364 ipcompstat.ipcomps_hdrops); 365 return; 366 } 367 368 ip = mtod(m, struct ip *); 369 ip->ip_len = htons(m->m_pkthdr.len); 370 ip->ip_sum = 0; 371 ip->ip_sum = in_cksum(m, ip->ip_hl << 2); 372 prot = ip->ip_p; 373 374 /* IP-in-IP encapsulation */ 375 if (prot == IPPROTO_IPIP) { 376 if (m->m_pkthdr.len - skip < sizeof(struct ip)) { 377 m_freem(m); 378 IPSEC_ISTAT(espstat.esps_hdrops, 379 ahstat.ahs_hdrops, 380 ipcompstat.ipcomps_hdrops); 381 return; 382 } 383 /* ipn will now contain the inner IPv4 header */ 384 m_copydata(m, skip, sizeof(struct ip), 385 (caddr_t) &ipn); 386 } 387 388 #ifdef INET6 389 /* IPv6-in-IP encapsulation. */ 390 if (prot == IPPROTO_IPV6) { 391 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) { 392 m_freem(m); 393 IPSEC_ISTAT(espstat.esps_hdrops, 394 ahstat.ahs_hdrops, 395 ipcompstat.ipcomps_hdrops); 396 return; 397 } 398 /* ip6n will now contain the inner IPv6 header. */ 399 m_copydata(m, skip, sizeof(struct ip6_hdr), 400 (caddr_t) &ip6n); 401 } 402 #endif /* INET6 */ 403 } 404 405 #ifdef INET6 406 /* Fix IPv6 header */ 407 if (af == AF_INET6) 408 { 409 if (m->m_len < sizeof(struct ip6_hdr) && 410 (m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 411 412 DPRINTF(("ipsec_common_input_cb(): processing failed " 413 "for SA %s/%08x\n", ipsp_address(&tdbp->tdb_dst, 414 buf, sizeof(buf)), ntohl(tdbp->tdb_spi))); 415 416 IPSEC_ISTAT(espstat.esps_hdrops, ahstat.ahs_hdrops, 417 ipcompstat.ipcomps_hdrops); 418 return; 419 } 420 421 ip6 = mtod(m, struct ip6_hdr *); 422 ip6->ip6_plen = htons(m->m_pkthdr.len - skip); 423 424 /* Save protocol */ 425 m_copydata(m, protoff, 1, (caddr_t) &prot); 426 427 /* IP-in-IP encapsulation */ 428 if (prot == IPPROTO_IPIP) { 429 if (m->m_pkthdr.len - skip < sizeof(struct ip)) { 430 m_freem(m); 431 IPSEC_ISTAT(espstat.esps_hdrops, 432 ahstat.ahs_hdrops, 433 ipcompstat.ipcomps_hdrops); 434 return; 435 } 436 /* ipn will now contain the inner IPv4 header */ 437 m_copydata(m, skip, sizeof(struct ip), (caddr_t) &ipn); 438 } 439 440 /* IPv6-in-IP encapsulation */ 441 if (prot == IPPROTO_IPV6) { 442 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) { 443 m_freem(m); 444 IPSEC_ISTAT(espstat.esps_hdrops, 445 ahstat.ahs_hdrops, 446 ipcompstat.ipcomps_hdrops); 447 return; 448 } 449 /* ip6n will now contain the inner IPv6 header. */ 450 m_copydata(m, skip, sizeof(struct ip6_hdr), 451 (caddr_t) &ip6n); 452 } 453 } 454 #endif /* INET6 */ 455 456 /* 457 * Fix TCP/UDP checksum of UDP encapsulated transport mode ESP packet. 458 * (RFC3948 3.1.2) 459 */ 460 if ((af == AF_INET || af == AF_INET6) && 461 (tdbp->tdb_flags & TDBF_UDPENCAP) && 462 (tdbp->tdb_flags & TDBF_TUNNELING) == 0) { 463 u_int16_t cksum; 464 465 switch (prot) { 466 case IPPROTO_UDP: 467 if (m->m_pkthdr.len < skip + sizeof(struct udphdr)) { 468 m_freem(m); 469 IPSEC_ISTAT(espstat.esps_hdrops, 470 ahstat.ahs_hdrops, 471 ipcompstat.ipcomps_hdrops); 472 return; 473 } 474 cksum = 0; 475 m_copyback(m, skip + offsetof(struct udphdr, uh_sum), 476 sizeof(cksum), &cksum, M_NOWAIT); 477 #ifdef INET6 478 if (af == AF_INET6) { 479 cksum = in6_cksum(m, IPPROTO_UDP, skip, 480 m->m_pkthdr.len - skip); 481 m_copyback(m, skip + offsetof(struct udphdr, 482 uh_sum), sizeof(cksum), &cksum, M_NOWAIT); 483 } 484 #endif 485 break; 486 case IPPROTO_TCP: 487 if (m->m_pkthdr.len < skip + sizeof(struct tcphdr)) { 488 m_freem(m); 489 IPSEC_ISTAT(espstat.esps_hdrops, 490 ahstat.ahs_hdrops, 491 ipcompstat.ipcomps_hdrops); 492 return; 493 } 494 cksum = 0; 495 m_copyback(m, skip + offsetof(struct tcphdr, th_sum), 496 sizeof(cksum), &cksum, M_NOWAIT); 497 if (af == AF_INET) 498 cksum = in4_cksum(m, IPPROTO_TCP, skip, 499 m->m_pkthdr.len - skip); 500 #ifdef INET6 501 else if (af == AF_INET6) 502 cksum = in6_cksum(m, IPPROTO_TCP, skip, 503 m->m_pkthdr.len - skip); 504 #endif 505 m_copyback(m, skip + offsetof(struct tcphdr, th_sum), 506 sizeof(cksum), &cksum, M_NOWAIT); 507 break; 508 } 509 } 510 511 /* 512 * Record what we've done to the packet (under what SA it was 513 * processed). 514 */ 515 if (tdbp->tdb_sproto != IPPROTO_IPCOMP) { 516 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE, 517 sizeof(struct tdb_ident), M_NOWAIT); 518 if (mtag == NULL) { 519 m_freem(m); 520 DPRINTF(("ipsec_common_input_cb(): failed to " 521 "get tag\n")); 522 IPSEC_ISTAT(espstat.esps_hdrops, ahstat.ahs_hdrops, 523 ipcompstat.ipcomps_hdrops); 524 return; 525 } 526 527 tdbi = (struct tdb_ident *)(mtag + 1); 528 tdbi->dst = tdbp->tdb_dst; 529 tdbi->proto = tdbp->tdb_sproto; 530 tdbi->spi = tdbp->tdb_spi; 531 tdbi->rdomain = tdbp->tdb_rdomain; 532 533 m_tag_prepend(m, mtag); 534 } 535 536 switch (sproto) { 537 case IPPROTO_ESP: 538 /* Packet is confidential ? */ 539 if (tdbp->tdb_encalgxform) 540 m->m_flags |= M_CONF; 541 542 /* Check if we had authenticated ESP. */ 543 if (tdbp->tdb_authalgxform) 544 m->m_flags |= M_AUTH; 545 break; 546 case IPPROTO_AH: 547 m->m_flags |= M_AUTH; 548 break; 549 case IPPROTO_IPCOMP: 550 m->m_flags |= M_COMP; 551 break; 552 default: 553 panic("%s: unknown/unsupported security protocol %d", 554 __func__, sproto); 555 } 556 557 #if NPF > 0 558 /* Add pf tag if requested. */ 559 pf_tag_packet(m, tdbp->tdb_tag, -1); 560 pf_pkt_addr_changed(m); 561 #endif 562 563 if (tdbp->tdb_flags & TDBF_TUNNELING) 564 m->m_flags |= M_TUNNEL; 565 566 #if NBPFILTER > 0 567 if ((encif = enc_getif(tdbp->tdb_rdomain, tdbp->tdb_tap)) != NULL) { 568 encif->if_ipackets++; 569 encif->if_ibytes += m->m_pkthdr.len; 570 571 if (encif->if_bpf) { 572 struct enchdr hdr; 573 574 hdr.af = af; 575 hdr.spi = tdbp->tdb_spi; 576 hdr.flags = m->m_flags & (M_AUTH|M_CONF); 577 578 bpf_mtap_hdr(encif->if_bpf, (char *)&hdr, 579 ENC_HDRLEN, m, BPF_DIRECTION_IN, NULL); 580 } 581 } 582 #endif 583 584 #if NPF > 0 585 /* 586 * The ip_deliver() shortcut avoids running through ip_input() with the 587 * same IP header twice. Packets in transport mode have to be be 588 * passed to pf explicitly. In tunnel mode the inner IP header will 589 * run through ip_input() and pf anyway. 590 */ 591 if ((tdbp->tdb_flags & TDBF_TUNNELING) == 0) { 592 struct ifnet *ifp; 593 594 /* This is the enc0 interface unless for ipcomp. */ 595 if ((ifp = if_get(m->m_pkthdr.ph_ifidx)) == NULL) { 596 m_freem(m); 597 return; 598 } 599 if (pf_test(af, PF_IN, ifp, &m) != PF_PASS) { 600 if_put(ifp); 601 m_freem(m); 602 return; 603 } 604 if_put(ifp); 605 if (m == NULL) 606 return; 607 } 608 #endif 609 /* Call the appropriate IPsec transform callback. */ 610 switch (af) { 611 case AF_INET: 612 ip_deliver(&m, &skip, prot, af); 613 return; 614 #ifdef INET6 615 case AF_INET6: 616 ip6_deliver(&m, &skip, prot, af); 617 return; 618 #endif /* INET6 */ 619 default: 620 DPRINTF(("ipsec_common_input_cb(): unknown/unsupported " 621 "protocol family %d\n", af)); 622 m_freem(m); 623 return; 624 } 625 #undef IPSEC_ISTAT 626 } 627 628 int 629 esp_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp, 630 size_t newlen) 631 { 632 /* All sysctl names at this level are terminal. */ 633 if (namelen != 1) 634 return (ENOTDIR); 635 636 switch (name[0]) { 637 case ESPCTL_STATS: 638 if (newp != NULL) 639 return (EPERM); 640 return (sysctl_struct(oldp, oldlenp, newp, newlen, 641 &espstat, sizeof(espstat))); 642 default: 643 if (name[0] < ESPCTL_MAXID) 644 return (sysctl_int_arr(espctl_vars, name, namelen, 645 oldp, oldlenp, newp, newlen)); 646 return (ENOPROTOOPT); 647 } 648 } 649 650 int 651 ah_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp, 652 size_t newlen) 653 { 654 /* All sysctl names at this level are terminal. */ 655 if (namelen != 1) 656 return (ENOTDIR); 657 658 switch (name[0]) { 659 case AHCTL_STATS: 660 if (newp != NULL) 661 return (EPERM); 662 return (sysctl_struct(oldp, oldlenp, newp, newlen, 663 &ahstat, sizeof(ahstat))); 664 default: 665 if (name[0] < AHCTL_MAXID) 666 return (sysctl_int_arr(ahctl_vars, name, namelen, 667 oldp, oldlenp, newp, newlen)); 668 return (ENOPROTOOPT); 669 } 670 } 671 672 int 673 ipcomp_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp, 674 size_t newlen) 675 { 676 /* All sysctl names at this level are terminal. */ 677 if (namelen != 1) 678 return (ENOTDIR); 679 680 switch (name[0]) { 681 case IPCOMPCTL_STATS: 682 if (newp != NULL) 683 return (EPERM); 684 return (sysctl_struct(oldp, oldlenp, newp, newlen, 685 &ipcompstat, sizeof(ipcompstat))); 686 default: 687 if (name[0] < IPCOMPCTL_MAXID) 688 return (sysctl_int_arr(ipcompctl_vars, name, namelen, 689 oldp, oldlenp, newp, newlen)); 690 return (ENOPROTOOPT); 691 } 692 } 693 694 /* IPv4 AH wrapper. */ 695 int 696 ah4_input(struct mbuf **mp, int *offp, int proto, int af) 697 { 698 ipsec_common_input(*mp, *offp, offsetof(struct ip, ip_p), AF_INET, 699 proto, 0); 700 return IPPROTO_DONE; 701 } 702 703 /* XXX rdomain */ 704 void 705 ah4_ctlinput(int cmd, struct sockaddr *sa, u_int rdomain, void *v) 706 { 707 if (sa->sa_family != AF_INET || 708 sa->sa_len != sizeof(struct sockaddr_in)) 709 return; 710 711 ipsec_common_ctlinput(rdomain, cmd, sa, v, IPPROTO_AH); 712 } 713 714 /* IPv4 ESP wrapper. */ 715 int 716 esp4_input(struct mbuf **mp, int *offp, int proto, int af) 717 { 718 ipsec_common_input(*mp, *offp, offsetof(struct ip, ip_p), AF_INET, 719 proto, 0); 720 return IPPROTO_DONE; 721 } 722 723 /* IPv4 IPCOMP wrapper */ 724 int 725 ipcomp4_input(struct mbuf **mp, int *offp, int proto, int af) 726 { 727 ipsec_common_input(*mp, *offp, offsetof(struct ip, ip_p), AF_INET, 728 proto, 0); 729 return IPPROTO_DONE; 730 } 731 732 void 733 ipsec_common_ctlinput(u_int rdomain, int cmd, struct sockaddr *sa, 734 void *v, int proto) 735 { 736 struct ip *ip = v; 737 738 if (cmd == PRC_MSGSIZE && ip && ip_mtudisc && ip->ip_v == 4) { 739 struct tdb *tdbp; 740 struct sockaddr_in dst; 741 struct icmp *icp; 742 int hlen = ip->ip_hl << 2; 743 u_int32_t spi, mtu; 744 ssize_t adjust; 745 746 /* Find the right MTU. */ 747 icp = (struct icmp *)((caddr_t) ip - 748 offsetof(struct icmp, icmp_ip)); 749 mtu = ntohs(icp->icmp_nextmtu); 750 751 /* 752 * Ignore the packet, if we do not receive a MTU 753 * or the MTU is too small to be acceptable. 754 */ 755 if (mtu < 296) 756 return; 757 758 memset(&dst, 0, sizeof(struct sockaddr_in)); 759 dst.sin_family = AF_INET; 760 dst.sin_len = sizeof(struct sockaddr_in); 761 dst.sin_addr.s_addr = ip->ip_dst.s_addr; 762 763 memcpy(&spi, (caddr_t)ip + hlen, sizeof(u_int32_t)); 764 765 tdbp = gettdb(rdomain, spi, (union sockaddr_union *)&dst, 766 proto); 767 if (tdbp == NULL || tdbp->tdb_flags & TDBF_INVALID) 768 return; 769 770 /* Walk the chain backwards to the first tdb */ 771 for (; tdbp; tdbp = tdbp->tdb_inext) { 772 if (tdbp->tdb_flags & TDBF_INVALID || 773 (adjust = ipsec_hdrsz(tdbp)) == -1) 774 return; 775 776 mtu -= adjust; 777 778 /* Store adjusted MTU in tdb */ 779 tdbp->tdb_mtu = mtu; 780 tdbp->tdb_mtutimeout = time_second + 781 ip_mtudisc_timeout; 782 DPRINTF(("ipsec_common_ctlinput: " 783 "spi %08x mtu %d adjust %ld\n", 784 ntohl(tdbp->tdb_spi), tdbp->tdb_mtu, 785 adjust)); 786 } 787 } 788 } 789 790 /* XXX rdomain */ 791 void 792 udpencap_ctlinput(int cmd, struct sockaddr *sa, u_int rdomain, void *v) 793 { 794 struct ip *ip = v; 795 struct tdb *tdbp; 796 struct icmp *icp; 797 u_int32_t mtu; 798 ssize_t adjust; 799 struct sockaddr_in dst, src; 800 union sockaddr_union *su_dst, *su_src; 801 802 NET_ASSERT_LOCKED(); 803 804 icp = (struct icmp *)((caddr_t) ip - offsetof(struct icmp, icmp_ip)); 805 mtu = ntohs(icp->icmp_nextmtu); 806 807 /* 808 * Ignore the packet, if we do not receive a MTU 809 * or the MTU is too small to be acceptable. 810 */ 811 if (mtu < 296) 812 return; 813 814 memset(&dst, 0, sizeof(dst)); 815 dst.sin_family = AF_INET; 816 dst.sin_len = sizeof(struct sockaddr_in); 817 dst.sin_addr.s_addr = ip->ip_dst.s_addr; 818 su_dst = (union sockaddr_union *)&dst; 819 memset(&src, 0, sizeof(src)); 820 src.sin_family = AF_INET; 821 src.sin_len = sizeof(struct sockaddr_in); 822 src.sin_addr.s_addr = ip->ip_src.s_addr; 823 su_src = (union sockaddr_union *)&src; 824 825 tdbp = gettdbbysrcdst(rdomain, 0, su_src, su_dst, IPPROTO_ESP); 826 827 for (; tdbp != NULL; tdbp = tdbp->tdb_snext) { 828 if (tdbp->tdb_sproto == IPPROTO_ESP && 829 ((tdbp->tdb_flags & (TDBF_INVALID|TDBF_UDPENCAP)) == 830 TDBF_UDPENCAP) && 831 !memcmp(&tdbp->tdb_dst, &dst, su_dst->sa.sa_len) && 832 !memcmp(&tdbp->tdb_src, &src, su_src->sa.sa_len)) { 833 if ((adjust = ipsec_hdrsz(tdbp)) != -1) { 834 /* Store adjusted MTU in tdb */ 835 tdbp->tdb_mtu = mtu - adjust; 836 tdbp->tdb_mtutimeout = time_second + 837 ip_mtudisc_timeout; 838 DPRINTF(("udpencap_ctlinput: " 839 "spi %08x mtu %d adjust %ld\n", 840 ntohl(tdbp->tdb_spi), tdbp->tdb_mtu, 841 adjust)); 842 } 843 } 844 } 845 } 846 847 /* XXX rdomain */ 848 void 849 esp4_ctlinput(int cmd, struct sockaddr *sa, u_int rdomain, void *v) 850 { 851 if (sa->sa_family != AF_INET || 852 sa->sa_len != sizeof(struct sockaddr_in)) 853 return; 854 855 ipsec_common_ctlinput(rdomain, cmd, sa, v, IPPROTO_ESP); 856 } 857 858 #ifdef INET6 859 /* IPv6 AH wrapper. */ 860 int 861 ah6_input(struct mbuf **mp, int *offp, int proto, int af) 862 { 863 int l = 0; 864 int protoff, nxt; 865 struct ip6_ext ip6e; 866 867 if (*offp < sizeof(struct ip6_hdr)) { 868 DPRINTF(("ah6_input(): bad offset\n")); 869 ahstat.ahs_hdrops++; 870 m_freem(*mp); 871 *mp = NULL; 872 return IPPROTO_DONE; 873 } else if (*offp == sizeof(struct ip6_hdr)) { 874 protoff = offsetof(struct ip6_hdr, ip6_nxt); 875 } else { 876 /* Chase down the header chain... */ 877 protoff = sizeof(struct ip6_hdr); 878 nxt = (mtod(*mp, struct ip6_hdr *))->ip6_nxt; 879 880 do { 881 protoff += l; 882 m_copydata(*mp, protoff, sizeof(ip6e), 883 (caddr_t) &ip6e); 884 885 if (nxt == IPPROTO_AH) 886 l = (ip6e.ip6e_len + 2) << 2; 887 else 888 l = (ip6e.ip6e_len + 1) << 3; 889 #ifdef DIAGNOSTIC 890 if (l <= 0) 891 panic("ah6_input: l went zero or negative"); 892 #endif 893 894 nxt = ip6e.ip6e_nxt; 895 } while (protoff + l < *offp); 896 897 /* Malformed packet check */ 898 if (protoff + l != *offp) { 899 DPRINTF(("ah6_input(): bad packet header chain\n")); 900 ahstat.ahs_hdrops++; 901 m_freem(*mp); 902 *mp = NULL; 903 return IPPROTO_DONE; 904 } 905 protoff += offsetof(struct ip6_ext, ip6e_nxt); 906 } 907 ipsec_common_input(*mp, *offp, protoff, AF_INET6, proto, 0); 908 return IPPROTO_DONE; 909 } 910 911 /* IPv6 ESP wrapper. */ 912 int 913 esp6_input(struct mbuf **mp, int *offp, int proto, int af) 914 { 915 int l = 0; 916 int protoff, nxt; 917 struct ip6_ext ip6e; 918 919 if (*offp < sizeof(struct ip6_hdr)) { 920 DPRINTF(("esp6_input(): bad offset\n")); 921 espstat.esps_hdrops++; 922 m_freem(*mp); 923 *mp = NULL; 924 return IPPROTO_DONE; 925 } else if (*offp == sizeof(struct ip6_hdr)) { 926 protoff = offsetof(struct ip6_hdr, ip6_nxt); 927 } else { 928 /* Chase down the header chain... */ 929 protoff = sizeof(struct ip6_hdr); 930 nxt = (mtod(*mp, struct ip6_hdr *))->ip6_nxt; 931 932 do { 933 protoff += l; 934 m_copydata(*mp, protoff, sizeof(ip6e), 935 (caddr_t) &ip6e); 936 937 if (nxt == IPPROTO_AH) 938 l = (ip6e.ip6e_len + 2) << 2; 939 else 940 l = (ip6e.ip6e_len + 1) << 3; 941 #ifdef DIAGNOSTIC 942 if (l <= 0) 943 panic("esp6_input: l went zero or negative"); 944 #endif 945 946 nxt = ip6e.ip6e_nxt; 947 } while (protoff + l < *offp); 948 949 /* Malformed packet check */ 950 if (protoff + l != *offp) { 951 DPRINTF(("esp6_input(): bad packet header chain\n")); 952 espstat.esps_hdrops++; 953 m_freem(*mp); 954 *mp = NULL; 955 return IPPROTO_DONE; 956 } 957 protoff += offsetof(struct ip6_ext, ip6e_nxt); 958 } 959 ipsec_common_input(*mp, *offp, protoff, AF_INET6, proto, 0); 960 return IPPROTO_DONE; 961 962 } 963 964 /* IPv6 IPcomp wrapper */ 965 int 966 ipcomp6_input(struct mbuf **mp, int *offp, int proto, int af) 967 { 968 int l = 0; 969 int protoff, nxt; 970 struct ip6_ext ip6e; 971 972 if (*offp < sizeof(struct ip6_hdr)) { 973 DPRINTF(("ipcomp6_input(): bad offset\n")); 974 ipcompstat.ipcomps_hdrops++; 975 m_freem(*mp); 976 *mp = NULL; 977 return IPPROTO_DONE; 978 } else if (*offp == sizeof(struct ip6_hdr)) { 979 protoff = offsetof(struct ip6_hdr, ip6_nxt); 980 } else { 981 /* Chase down the header chain... */ 982 protoff = sizeof(struct ip6_hdr); 983 nxt = (mtod(*mp, struct ip6_hdr *))->ip6_nxt; 984 985 do { 986 protoff += l; 987 m_copydata(*mp, protoff, sizeof(ip6e), 988 (caddr_t) &ip6e); 989 if (nxt == IPPROTO_AH) 990 l = (ip6e.ip6e_len + 2) << 2; 991 else 992 l = (ip6e.ip6e_len + 1) << 3; 993 #ifdef DIAGNOSTIC 994 if (l <= 0) 995 panic("ipcomp6_input: l went zero or negative"); 996 #endif 997 998 nxt = ip6e.ip6e_nxt; 999 } while (protoff + l < *offp); 1000 1001 /* Malformed packet check */ 1002 if (protoff + l != *offp) { 1003 DPRINTF(("ipcomp6_input(): bad packet header chain\n")); 1004 ipcompstat.ipcomps_hdrops++; 1005 m_freem(*mp); 1006 *mp = NULL; 1007 return IPPROTO_DONE; 1008 } 1009 1010 protoff += offsetof(struct ip6_ext, ip6e_nxt); 1011 } 1012 ipsec_common_input(*mp, *offp, protoff, AF_INET6, proto, 0); 1013 return IPPROTO_DONE; 1014 } 1015 #endif /* INET6 */ 1016 1017 int 1018 ipsec_forward_check(struct mbuf *m, int hlen, int af) 1019 { 1020 struct tdb *tdb; 1021 struct tdb_ident *tdbi; 1022 struct m_tag *mtag; 1023 int error = 0; 1024 1025 /* 1026 * IPsec policy check for forwarded packets. Look at 1027 * inner-most IPsec SA used. 1028 */ 1029 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL); 1030 if (mtag != NULL) { 1031 tdbi = (struct tdb_ident *)(mtag + 1); 1032 tdb = gettdb(tdbi->rdomain, tdbi->spi, &tdbi->dst, tdbi->proto); 1033 } else 1034 tdb = NULL; 1035 ipsp_spd_lookup(m, af, hlen, &error, IPSP_DIRECTION_IN, tdb, NULL, 0); 1036 1037 return error; 1038 } 1039 1040 int 1041 ipsec_local_check(struct mbuf *m, int hlen, int proto, int af) 1042 { 1043 struct tdb *tdb; 1044 struct tdb_ident *tdbi; 1045 struct m_tag *mtag; 1046 int error = 0; 1047 1048 /* 1049 * If it's a protected packet for us, skip the policy check. 1050 * That's because we really only care about the properties of 1051 * the protected packet, and not the intermediate versions. 1052 * While this is not the most paranoid setting, it allows 1053 * some flexibility in handling nested tunnels (in setting up 1054 * the policies). 1055 */ 1056 if ((proto == IPPROTO_ESP) || (proto == IPPROTO_AH) || 1057 (proto == IPPROTO_IPCOMP)) 1058 return 0; 1059 1060 /* 1061 * If the protected packet was tunneled, then we need to 1062 * verify the protected packet's information, not the 1063 * external headers. Thus, skip the policy lookup for the 1064 * external packet, and keep the IPsec information linked on 1065 * the packet header (the encapsulation routines know how 1066 * to deal with that). 1067 */ 1068 if ((proto == IPPROTO_IPV4) || (proto == IPPROTO_IPV6)) 1069 return 0; 1070 1071 /* 1072 * When processing IPv6 header chains, do not look at the 1073 * outer header. The inner protocol is relevant and will 1074 * be checked by the local delivery loop later. 1075 */ 1076 if ((af == AF_INET6) && ((proto == IPPROTO_DSTOPTS) || 1077 (proto == IPPROTO_ROUTING) || (proto == IPPROTO_FRAGMENT))) 1078 return 0; 1079 1080 /* 1081 * If the protected packet is TCP or UDP, we'll do the 1082 * policy check in the respective input routine, so we can 1083 * check for bypass sockets. 1084 */ 1085 if ((proto == IPPROTO_TCP) || (proto == IPPROTO_UDP)) 1086 return 0; 1087 1088 /* 1089 * IPsec policy check for local-delivery packets. Look at the 1090 * inner-most SA that protected the packet. This is in fact 1091 * a bit too restrictive (it could end up causing packets to 1092 * be dropped that semantically follow the policy, e.g., in 1093 * certain SA-bundle configurations); but the alternative is 1094 * very complicated (and requires keeping track of what 1095 * kinds of tunneling headers have been seen in-between the 1096 * IPsec headers), and I don't think we lose much functionality 1097 * that's needed in the real world (who uses bundles anyway ?). 1098 */ 1099 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL); 1100 if (mtag) { 1101 tdbi = (struct tdb_ident *)(mtag + 1); 1102 tdb = gettdb(tdbi->rdomain, tdbi->spi, &tdbi->dst, 1103 tdbi->proto); 1104 } else 1105 tdb = NULL; 1106 ipsp_spd_lookup(m, af, hlen, &error, IPSP_DIRECTION_IN, 1107 tdb, NULL, 0); 1108 1109 return error; 1110 } 1111