ipsec_input.c revision 171497
1157184Sache/* $FreeBSD: head/sys/netipsec/ipsec_input.c 171497 2007-07-19 09:57:54Z bz $ */ 2157184Sache/* $OpenBSD: ipsec_input.c,v 1.63 2003/02/20 18:35:43 deraadt Exp $ */ 3157184Sache/*- 4157184Sache * The authors of this code are John Ioannidis (ji@tla.org), 5157184Sache * Angelos D. Keromytis (kermit@csd.uch.gr) and 6157184Sache * Niels Provos (provos@physnet.uni-hamburg.de). 7157184Sache * 8157184Sache * This code was written by John Ioannidis for BSD/OS in Athens, Greece, 9157184Sache * in November 1995. 10157184Sache * 11157184Sache * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996, 12157184Sache * by Angelos D. Keromytis. 13157184Sache * 14157184Sache * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis 15157184Sache * and Niels Provos. 16157184Sache * 17157184Sache * Additional features in 1999 by Angelos D. Keromytis. 18157184Sache * 19157184Sache * Copyright (C) 1995, 1996, 1997, 1998, 1999 by John Ioannidis, 20157184Sache * Angelos D. Keromytis and Niels Provos. 21157184Sache * Copyright (c) 2001, Angelos D. Keromytis. 22157184Sache * 23157184Sache * Permission to use, copy, and modify this software with or without fee 24157184Sache * is hereby granted, provided that this entire notice is included in 25157184Sache * all copies of any software which is or includes a copy or 26157184Sache * modification of this software. 27157184Sache * You may use this code under the GNU public license if you so wish. Please 28157184Sache * contribute changes back to the authors under this freer than GPL license 29157184Sache * so that we may further the use of strong encryption without limitations to 30157184Sache * all. 31157184Sache * 32157184Sache * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR 33157184Sache * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY 34157184Sache * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE 35157184Sache * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR 36157184Sache * PURPOSE. 37157184Sache */ 38157184Sache 39157184Sache/* 40157184Sache * IPsec input processing. 41157184Sache */ 42157184Sache 43157184Sache#include "opt_inet.h" 44157184Sache#include "opt_inet6.h" 45157184Sache#include "opt_ipsec.h" 46157184Sache#include "opt_enc.h" 47157184Sache 48157184Sache#include <sys/param.h> 49157184Sache#include <sys/systm.h> 50157184Sache#include <sys/malloc.h> 51157184Sache#include <sys/mbuf.h> 52157184Sache#include <sys/domain.h> 53157184Sache#include <sys/protosw.h> 54157184Sache#include <sys/socket.h> 55157184Sache#include <sys/errno.h> 56157184Sache#include <sys/syslog.h> 57157184Sache 58157184Sache#include <net/if.h> 59157184Sache#include <net/pfil.h> 60157184Sache#include <net/route.h> 61157184Sache#include <net/netisr.h> 62157184Sache 63157184Sache#include <netinet/in.h> 64157184Sache#include <netinet/in_systm.h> 65157184Sache#include <netinet/ip.h> 66157184Sache#include <netinet/ip_var.h> 67157184Sache#include <netinet/in_var.h> 68157184Sache 69157184Sache#include <netinet/ip6.h> 70157184Sache#ifdef INET6 71157184Sache#include <netinet6/ip6_var.h> 72157184Sache#endif 73157184Sache#include <netinet/in_pcb.h> 74157184Sache#ifdef INET6 75157184Sache#include <netinet/icmp6.h> 76157184Sache#endif 77157184Sache 78157184Sache#include <netipsec/ipsec.h> 79157184Sache#ifdef INET6 80157184Sache#include <netipsec/ipsec6.h> 81157184Sache#endif 82157184Sache#include <netipsec/ah_var.h> 83157184Sache#include <netipsec/esp.h> 84157184Sache#include <netipsec/esp_var.h> 85157184Sache#include <netipsec/ipcomp_var.h> 86157184Sache 87157184Sache#include <netipsec/key.h> 88157184Sache#include <netipsec/keydb.h> 89157184Sache 90157184Sache#include <netipsec/xform.h> 91157184Sache#include <netinet6/ip6protosw.h> 92157184Sache 93157184Sache#include <machine/in_cksum.h> 94157184Sache#include <machine/stdarg.h> 95157184Sache 96157184Sache#define IPSEC_ISTAT(p,x,y,z) ((p) == IPPROTO_ESP ? (x)++ : \ 97157184Sache (p) == IPPROTO_AH ? (y)++ : (z)++) 98157184Sache 99157184Sachestatic void ipsec4_common_ctlinput(int, struct sockaddr *, void *, int); 100157184Sache 101157184Sache/* 102157184Sache * ipsec_common_input gets called when an IPsec-protected packet 103157184Sache * is received by IPv4 or IPv6. It's job is to find the right SA 104157184Sache * and call the appropriate transform. The transform callback 105157184Sache * takes care of further processing (like ingress filtering). 106157184Sache */ 107157184Sachestatic int 108157184Sacheipsec_common_input(struct mbuf *m, int skip, int protoff, int af, int sproto) 109157184Sache{ 110157184Sache union sockaddr_union dst_address; 111157184Sache struct secasvar *sav; 112157184Sache u_int32_t spi; 113157184Sache int error; 114157184Sache 115157184Sache IPSEC_ISTAT(sproto, espstat.esps_input, ahstat.ahs_input, 116157184Sache ipcompstat.ipcomps_input); 117157184Sache 118157184Sache IPSEC_ASSERT(m != NULL, ("null packet")); 119157184Sache 120157184Sache IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH || 121157184Sache sproto == IPPROTO_IPCOMP, 122157184Sache ("unexpected security protocol %u", sproto)); 123157184Sache 124157184Sache if ((sproto == IPPROTO_ESP && !esp_enable) || 125157184Sache (sproto == IPPROTO_AH && !ah_enable) || 126157184Sache (sproto == IPPROTO_IPCOMP && !ipcomp_enable)) { 127157184Sache m_freem(m); 128157184Sache IPSEC_ISTAT(sproto, espstat.esps_pdrops, ahstat.ahs_pdrops, 129157184Sache ipcompstat.ipcomps_pdrops); 130157184Sache return EOPNOTSUPP; 131157184Sache } 132157184Sache 133157184Sache if (m->m_pkthdr.len - skip < 2 * sizeof (u_int32_t)) { 134157184Sache m_freem(m); 135157184Sache IPSEC_ISTAT(sproto, espstat.esps_hdrops, ahstat.ahs_hdrops, 136157184Sache ipcompstat.ipcomps_hdrops); 137157184Sache DPRINTF(("%s: packet too small\n", __func__)); 138157184Sache return EINVAL; 139157184Sache } 140157184Sache 141157184Sache /* Retrieve the SPI from the relevant IPsec header */ 142157184Sache if (sproto == IPPROTO_ESP) 143157184Sache m_copydata(m, skip, sizeof(u_int32_t), (caddr_t) &spi); 144157184Sache else if (sproto == IPPROTO_AH) 145157184Sache m_copydata(m, skip + sizeof(u_int32_t), sizeof(u_int32_t), 146157184Sache (caddr_t) &spi); 147157184Sache else if (sproto == IPPROTO_IPCOMP) { 148157184Sache u_int16_t cpi; 149157184Sache m_copydata(m, skip + sizeof(u_int16_t), sizeof(u_int16_t), 150157184Sache (caddr_t) &cpi); 151157184Sache spi = ntohl(htons(cpi)); 152157184Sache } 153157184Sache 154157184Sache /* 155157184Sache * Find the SA and (indirectly) call the appropriate 156157184Sache * kernel crypto routine. The resulting mbuf chain is a valid 157157184Sache * IP packet ready to go through input processing. 158157184Sache */ 159157184Sache bzero(&dst_address, sizeof (dst_address)); 160157184Sache dst_address.sa.sa_family = af; 161157184Sache switch (af) { 162157184Sache#ifdef INET 163157184Sache case AF_INET: 164157184Sache dst_address.sin.sin_len = sizeof(struct sockaddr_in); 165157184Sache m_copydata(m, offsetof(struct ip, ip_dst), 166157184Sache sizeof(struct in_addr), 167157184Sache (caddr_t) &dst_address.sin.sin_addr); 168157184Sache break; 169157184Sache#endif /* INET */ 170157184Sache#ifdef INET6 171157184Sache case AF_INET6: 172157184Sache dst_address.sin6.sin6_len = sizeof(struct sockaddr_in6); 173157184Sache m_copydata(m, offsetof(struct ip6_hdr, ip6_dst), 174157184Sache sizeof(struct in6_addr), 175157184Sache (caddr_t) &dst_address.sin6.sin6_addr); 176157184Sache break; 177157184Sache#endif /* INET6 */ 178157184Sache default: 179157184Sache DPRINTF(("%s: unsupported protocol family %u\n", __func__, af)); 180157184Sache m_freem(m); 181157184Sache IPSEC_ISTAT(sproto, espstat.esps_nopf, ahstat.ahs_nopf, 182157184Sache ipcompstat.ipcomps_nopf); 183157184Sache return EPFNOSUPPORT; 184157184Sache } 185157184Sache 186157184Sache /* NB: only pass dst since key_allocsa follows RFC2401 */ 187157184Sache sav = KEY_ALLOCSA(&dst_address, sproto, spi); 188157184Sache if (sav == NULL) { 189157184Sache DPRINTF(("%s: no key association found for SA %s/%08lx/%u\n", 190157184Sache __func__, ipsec_address(&dst_address), 191157184Sache (u_long) ntohl(spi), sproto)); 192157184Sache IPSEC_ISTAT(sproto, espstat.esps_notdb, ahstat.ahs_notdb, 193157184Sache ipcompstat.ipcomps_notdb); 194157184Sache m_freem(m); 195157184Sache return ENOENT; 196157184Sache } 197157184Sache 198157184Sache if (sav->tdb_xform == NULL) { 199157184Sache DPRINTF(("%s: attempted to use uninitialized SA %s/%08lx/%u\n", 200157184Sache __func__, ipsec_address(&dst_address), 201157184Sache (u_long) ntohl(spi), sproto)); 202157184Sache IPSEC_ISTAT(sproto, espstat.esps_noxform, ahstat.ahs_noxform, 203157184Sache ipcompstat.ipcomps_noxform); 204157184Sache KEY_FREESAV(&sav); 205157184Sache m_freem(m); 206157184Sache return ENXIO; 207157184Sache } 208157184Sache 209157184Sache /* 210157184Sache * Call appropriate transform and return -- callback takes care of 211157184Sache * everything else. 212157184Sache */ 213157184Sache error = (*sav->tdb_xform->xf_input)(m, sav, skip, protoff); 214157184Sache KEY_FREESAV(&sav); 215157184Sache return error; 216157184Sache} 217157184Sache 218157184Sache#ifdef INET 219157184Sache/* 220157184Sache * Common input handler for IPv4 AH, ESP, and IPCOMP. 221157184Sache */ 222157184Sacheint 223157184Sacheipsec4_common_input(struct mbuf *m, ...) 224157184Sache{ 225157184Sache va_list ap; 226157184Sache int off, nxt; 227157184Sache 228157184Sache va_start(ap, m); 229157184Sache off = va_arg(ap, int); 230157184Sache nxt = va_arg(ap, int); 231157184Sache va_end(ap); 232157184Sache 233157184Sache return ipsec_common_input(m, off, offsetof(struct ip, ip_p), 234157184Sache AF_INET, nxt); 235157184Sache} 236157184Sache 237157184Sachevoid 238157184Sacheah4_input(struct mbuf *m, int off) 239157184Sache{ 240157184Sache ipsec4_common_input(m, off, IPPROTO_AH); 241157184Sache} 242157184Sachevoid 243157184Sacheah4_ctlinput(int cmd, struct sockaddr *sa, void *v) 244157184Sache{ 245157184Sache if (sa->sa_family == AF_INET && 246157184Sache sa->sa_len == sizeof(struct sockaddr_in)) 247157184Sache ipsec4_common_ctlinput(cmd, sa, v, IPPROTO_AH); 248157184Sache} 249157184Sache 250157184Sachevoid 251157184Sacheesp4_input(struct mbuf *m, int off) 252157184Sache{ 253157184Sache ipsec4_common_input(m, off, IPPROTO_ESP); 254157184Sache} 255157184Sachevoid 256157184Sacheesp4_ctlinput(int cmd, struct sockaddr *sa, void *v) 257157184Sache{ 258157184Sache if (sa->sa_family == AF_INET && 259157184Sache sa->sa_len == sizeof(struct sockaddr_in)) 260157184Sache ipsec4_common_ctlinput(cmd, sa, v, IPPROTO_ESP); 261157184Sache} 262157184Sache 263157184Sachevoid 264157184Sacheipcomp4_input(struct mbuf *m, int off) 265157184Sache{ 266157184Sache ipsec4_common_input(m, off, IPPROTO_IPCOMP); 267157184Sache} 268157184Sache 269157184Sache/* 270157184Sache * IPsec input callback for INET protocols. 271157184Sache * This routine is called as the transform callback. 272157184Sache * Takes care of filtering and other sanity checks on 273157184Sache * the processed packet. 274157184Sache */ 275157184Sacheint 276157184Sacheipsec4_common_input_cb(struct mbuf *m, struct secasvar *sav, 277157184Sache int skip, int protoff, struct m_tag *mt) 278157184Sache{ 279157184Sache int prot, af, sproto; 280157184Sache struct ip *ip; 281157184Sache struct m_tag *mtag; 282157184Sache struct tdb_ident *tdbi; 283157184Sache struct secasindex *saidx; 284157184Sache int error; 285157184Sache#ifdef INET6 286157184Sache#ifdef notyet 287157184Sache char ip6buf[INET6_ADDRSTRLEN]; 288157184Sache#endif 289157184Sache#endif 290157184Sache 291157184Sache IPSEC_SPLASSERT_SOFTNET(__func__); 292157184Sache 293157184Sache IPSEC_ASSERT(m != NULL, ("null mbuf")); 294157184Sache IPSEC_ASSERT(sav != NULL, ("null SA")); 295157184Sache IPSEC_ASSERT(sav->sah != NULL, ("null SAH")); 296157184Sache saidx = &sav->sah->saidx; 297157184Sache af = saidx->dst.sa.sa_family; 298157184Sache IPSEC_ASSERT(af == AF_INET, ("unexpected af %u", af)); 299157184Sache sproto = saidx->proto; 300157184Sache IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH || 301157184Sache sproto == IPPROTO_IPCOMP, 302157184Sache ("unexpected security protocol %u", sproto)); 303157184Sache 304157184Sache /* Sanity check */ 305157184Sache if (m == NULL) { 306157184Sache DPRINTF(("%s: null mbuf", __func__)); 307157184Sache IPSEC_ISTAT(sproto, espstat.esps_badkcr, ahstat.ahs_badkcr, 308157184Sache ipcompstat.ipcomps_badkcr); 309157184Sache KEY_FREESAV(&sav); 310157184Sache return EINVAL; 311157184Sache } 312157184Sache 313157184Sache if (skip != 0) { 314157184Sache /* Fix IPv4 header */ 315157184Sache if (m->m_len < skip && (m = m_pullup(m, skip)) == NULL) { 316157184Sache DPRINTF(("%s: processing failed for SA %s/%08lx\n", 317157184Sache __func__, ipsec_address(&sav->sah->saidx.dst), 318157184Sache (u_long) ntohl(sav->spi))); 319157184Sache IPSEC_ISTAT(sproto, espstat.esps_hdrops, ahstat.ahs_hdrops, 320157184Sache ipcompstat.ipcomps_hdrops); 321157184Sache error = ENOBUFS; 322157184Sache goto bad; 323157184Sache } 324157184Sache 325157184Sache ip = mtod(m, struct ip *); 326157184Sache ip->ip_len = htons(m->m_pkthdr.len); 327157184Sache ip->ip_off = htons(ip->ip_off); 328157184Sache ip->ip_sum = 0; 329157184Sache ip->ip_sum = in_cksum(m, ip->ip_hl << 2); 330157184Sache } else { 331157184Sache ip = mtod(m, struct ip *); 332157184Sache } 333157184Sache prot = ip->ip_p; 334157184Sache 335157184Sache#ifdef notyet 336157184Sache /* IP-in-IP encapsulation */ 337157184Sache if (prot == IPPROTO_IPIP) { 338157184Sache struct ip ipn; 339157184Sache 340157184Sache if (m->m_pkthdr.len - skip < sizeof(struct ip)) { 341157184Sache IPSEC_ISTAT(sproto, espstat.esps_hdrops, 342157184Sache ahstat.ahs_hdrops, 343157184Sache ipcompstat.ipcomps_hdrops); 344157184Sache error = EINVAL; 345157184Sache goto bad; 346157184Sache } 347157184Sache /* ipn will now contain the inner IPv4 header */ 348157184Sache m_copydata(m, ip->ip_hl << 2, sizeof(struct ip), 349157184Sache (caddr_t) &ipn); 350157184Sache 351157184Sache /* XXX PROXY address isn't recorded in SAH */ 352157184Sache /* 353157184Sache * Check that the inner source address is the same as 354157184Sache * the proxy address, if available. 355157184Sache */ 356157184Sache if ((saidx->proxy.sa.sa_family == AF_INET && 357157184Sache saidx->proxy.sin.sin_addr.s_addr != 358157184Sache INADDR_ANY && 359157184Sache ipn.ip_src.s_addr != 360157184Sache saidx->proxy.sin.sin_addr.s_addr) || 361157184Sache (saidx->proxy.sa.sa_family != AF_INET && 362157184Sache saidx->proxy.sa.sa_family != 0)) { 363157184Sache 364157184Sache DPRINTF(("%s: inner source address %s doesn't " 365157184Sache "correspond to expected proxy source %s, " 366157184Sache "SA %s/%08lx\n", __func__, 367157184Sache inet_ntoa4(ipn.ip_src), 368157184Sache ipsp_address(saidx->proxy), 369157184Sache ipsp_address(saidx->dst), 370157184Sache (u_long) ntohl(sav->spi))); 371157184Sache 372157184Sache IPSEC_ISTAT(sproto, espstat.esps_pdrops, 373157184Sache ahstat.ahs_pdrops, 374157184Sache ipcompstat.ipcomps_pdrops); 375157184Sache error = EACCES; 376157184Sache goto bad; 377157184Sache } 378157184Sache } 379157184Sache#ifdef INET6 380157184Sache /* IPv6-in-IP encapsulation. */ 381157184Sache if (prot == IPPROTO_IPV6) { 382157184Sache struct ip6_hdr ip6n; 383157184Sache 384157184Sache if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) { 385157184Sache IPSEC_ISTAT(sproto, espstat.esps_hdrops, 386157184Sache ahstat.ahs_hdrops, 387157184Sache ipcompstat.ipcomps_hdrops); 388 error = EINVAL; 389 goto bad; 390 } 391 /* ip6n will now contain the inner IPv6 header. */ 392 m_copydata(m, ip->ip_hl << 2, sizeof(struct ip6_hdr), 393 (caddr_t) &ip6n); 394 395 /* 396 * Check that the inner source address is the same as 397 * the proxy address, if available. 398 */ 399 if ((saidx->proxy.sa.sa_family == AF_INET6 && 400 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) && 401 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src, 402 &saidx->proxy.sin6.sin6_addr)) || 403 (saidx->proxy.sa.sa_family != AF_INET6 && 404 saidx->proxy.sa.sa_family != 0)) { 405 406 DPRINTF(("%s: inner source address %s doesn't " 407 "correspond to expected proxy source %s, " 408 "SA %s/%08lx\n", __func__, 409 ip6_sprintf(ip6buf, &ip6n.ip6_src), 410 ipsec_address(&saidx->proxy), 411 ipsec_address(&saidx->dst), 412 (u_long) ntohl(sav->spi))); 413 414 IPSEC_ISTAT(sproto, espstat.esps_pdrops, 415 ahstat.ahs_pdrops, 416 ipcompstat.ipcomps_pdrops); 417 error = EACCES; 418 goto bad; 419 } 420 } 421#endif /* INET6 */ 422#endif /*XXX*/ 423 424 /* 425 * Record what we've done to the packet (under what SA it was 426 * processed). If we've been passed an mtag, it means the packet 427 * was already processed by an ethernet/crypto combo card and 428 * thus has a tag attached with all the right information, but 429 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to 430 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type. 431 */ 432 if (mt == NULL && sproto != IPPROTO_IPCOMP) { 433 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE, 434 sizeof(struct tdb_ident), M_NOWAIT); 435 if (mtag == NULL) { 436 DPRINTF(("%s: failed to get tag\n", __func__)); 437 IPSEC_ISTAT(sproto, espstat.esps_hdrops, 438 ahstat.ahs_hdrops, ipcompstat.ipcomps_hdrops); 439 error = ENOMEM; 440 goto bad; 441 } 442 443 tdbi = (struct tdb_ident *)(mtag + 1); 444 bcopy(&saidx->dst, &tdbi->dst, saidx->dst.sa.sa_len); 445 tdbi->proto = sproto; 446 tdbi->spi = sav->spi; 447 448 m_tag_prepend(m, mtag); 449 } else if (mt != NULL) { 450 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE; 451 /* XXX do we need to mark m_flags??? */ 452 } 453 454 key_sa_recordxfer(sav, m); /* record data transfer */ 455 456#ifdef DEV_ENC 457 /* 458 * Pass the mbuf to enc0 for bpf and pfil. We will filter the IPIP 459 * packet later after it has been decapsulated. 460 */ 461 ipsec_bpf(m, sav, AF_INET); 462 463 if (prot != IPPROTO_IPIP) 464 if ((error = ipsec_filter(&m, PFIL_IN)) != 0) 465 return (error); 466#endif 467 468 /* 469 * Re-dispatch via software interrupt. 470 */ 471 if ((error = netisr_queue(NETISR_IP, m))) { 472 IPSEC_ISTAT(sproto, espstat.esps_qfull, ahstat.ahs_qfull, 473 ipcompstat.ipcomps_qfull); 474 475 DPRINTF(("%s: queue full; proto %u packet dropped\n", 476 __func__, sproto)); 477 return error; 478 } 479 return 0; 480bad: 481 m_freem(m); 482 return error; 483} 484 485void 486ipsec4_common_ctlinput(int cmd, struct sockaddr *sa, void *v, int proto) 487{ 488 /* XXX nothing just yet */ 489} 490#endif /* INET */ 491 492#ifdef INET6 493/* IPv6 AH wrapper. */ 494int 495ipsec6_common_input(struct mbuf **mp, int *offp, int proto) 496{ 497 int l = 0; 498 int protoff; 499 struct ip6_ext ip6e; 500 501 if (*offp < sizeof(struct ip6_hdr)) { 502 DPRINTF(("%s: bad offset %u\n", __func__, *offp)); 503 return IPPROTO_DONE; 504 } else if (*offp == sizeof(struct ip6_hdr)) { 505 protoff = offsetof(struct ip6_hdr, ip6_nxt); 506 } else { 507 /* Chase down the header chain... */ 508 protoff = sizeof(struct ip6_hdr); 509 510 do { 511 protoff += l; 512 m_copydata(*mp, protoff, sizeof(ip6e), 513 (caddr_t) &ip6e); 514 515 if (ip6e.ip6e_nxt == IPPROTO_AH) 516 l = (ip6e.ip6e_len + 2) << 2; 517 else 518 l = (ip6e.ip6e_len + 1) << 3; 519 IPSEC_ASSERT(l > 0, ("l went zero or negative")); 520 } while (protoff + l < *offp); 521 522 /* Malformed packet check */ 523 if (protoff + l != *offp) { 524 DPRINTF(("%s: bad packet header chain, protoff %u, " 525 "l %u, off %u\n", __func__, protoff, l, *offp)); 526 IPSEC_ISTAT(proto, espstat.esps_hdrops, 527 ahstat.ahs_hdrops, 528 ipcompstat.ipcomps_hdrops); 529 m_freem(*mp); 530 *mp = NULL; 531 return IPPROTO_DONE; 532 } 533 protoff += offsetof(struct ip6_ext, ip6e_nxt); 534 } 535 (void) ipsec_common_input(*mp, *offp, protoff, AF_INET6, proto); 536 return IPPROTO_DONE; 537} 538 539/* 540 * IPsec input callback, called by the transform callback. Takes care of 541 * filtering and other sanity checks on the processed packet. 542 */ 543int 544ipsec6_common_input_cb(struct mbuf *m, struct secasvar *sav, int skip, int protoff, 545 struct m_tag *mt) 546{ 547 int prot, af, sproto; 548 struct ip6_hdr *ip6; 549 struct m_tag *mtag; 550 struct tdb_ident *tdbi; 551 struct secasindex *saidx; 552 int nxt; 553 u_int8_t nxt8; 554 int error, nest; 555#ifdef notyet 556 char ip6buf[INET6_ADDRSTRLEN]; 557#endif 558 559 IPSEC_ASSERT(m != NULL, ("null mbuf")); 560 IPSEC_ASSERT(sav != NULL, ("null SA")); 561 IPSEC_ASSERT(sav->sah != NULL, ("null SAH")); 562 saidx = &sav->sah->saidx; 563 af = saidx->dst.sa.sa_family; 564 IPSEC_ASSERT(af == AF_INET6, ("unexpected af %u", af)); 565 sproto = saidx->proto; 566 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH || 567 sproto == IPPROTO_IPCOMP, 568 ("unexpected security protocol %u", sproto)); 569 570 /* Sanity check */ 571 if (m == NULL) { 572 DPRINTF(("%s: null mbuf", __func__)); 573 IPSEC_ISTAT(sproto, espstat.esps_badkcr, ahstat.ahs_badkcr, 574 ipcompstat.ipcomps_badkcr); 575 error = EINVAL; 576 goto bad; 577 } 578 579 /* Fix IPv6 header */ 580 if (m->m_len < sizeof(struct ip6_hdr) && 581 (m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 582 583 DPRINTF(("%s: processing failed for SA %s/%08lx\n", 584 __func__, ipsec_address(&sav->sah->saidx.dst), 585 (u_long) ntohl(sav->spi))); 586 587 IPSEC_ISTAT(sproto, espstat.esps_hdrops, ahstat.ahs_hdrops, 588 ipcompstat.ipcomps_hdrops); 589 error = EACCES; 590 goto bad; 591 } 592 593 ip6 = mtod(m, struct ip6_hdr *); 594 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 595 596 /* Save protocol */ 597 m_copydata(m, protoff, 1, (unsigned char *) &prot); 598 599#ifdef notyet 600#ifdef INET 601 /* IP-in-IP encapsulation */ 602 if (prot == IPPROTO_IPIP) { 603 struct ip ipn; 604 605 if (m->m_pkthdr.len - skip < sizeof(struct ip)) { 606 IPSEC_ISTAT(sproto, espstat.esps_hdrops, 607 ahstat.ahs_hdrops, 608 ipcompstat.ipcomps_hdrops); 609 error = EINVAL; 610 goto bad; 611 } 612 /* ipn will now contain the inner IPv4 header */ 613 m_copydata(m, skip, sizeof(struct ip), (caddr_t) &ipn); 614 615 /* 616 * Check that the inner source address is the same as 617 * the proxy address, if available. 618 */ 619 if ((saidx->proxy.sa.sa_family == AF_INET && 620 saidx->proxy.sin.sin_addr.s_addr != INADDR_ANY && 621 ipn.ip_src.s_addr != saidx->proxy.sin.sin_addr.s_addr) || 622 (saidx->proxy.sa.sa_family != AF_INET && 623 saidx->proxy.sa.sa_family != 0)) { 624 625 DPRINTF(("%s: inner source address %s doesn't " 626 "correspond to expected proxy source %s, " 627 "SA %s/%08lx\n", __func__, 628 inet_ntoa4(ipn.ip_src), 629 ipsec_address(&saidx->proxy), 630 ipsec_address(&saidx->dst), 631 (u_long) ntohl(sav->spi))); 632 633 IPSEC_ISTATsproto, (espstat.esps_pdrops, 634 ahstat.ahs_pdrops, ipcompstat.ipcomps_pdrops); 635 error = EACCES; 636 goto bad; 637 } 638 } 639#endif /* INET */ 640 641 /* IPv6-in-IP encapsulation */ 642 if (prot == IPPROTO_IPV6) { 643 struct ip6_hdr ip6n; 644 645 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) { 646 IPSEC_ISTAT(sproto, espstat.esps_hdrops, 647 ahstat.ahs_hdrops, 648 ipcompstat.ipcomps_hdrops); 649 error = EINVAL; 650 goto bad; 651 } 652 /* ip6n will now contain the inner IPv6 header. */ 653 m_copydata(m, skip, sizeof(struct ip6_hdr), 654 (caddr_t) &ip6n); 655 656 /* 657 * Check that the inner source address is the same as 658 * the proxy address, if available. 659 */ 660 if ((saidx->proxy.sa.sa_family == AF_INET6 && 661 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) && 662 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src, 663 &saidx->proxy.sin6.sin6_addr)) || 664 (saidx->proxy.sa.sa_family != AF_INET6 && 665 saidx->proxy.sa.sa_family != 0)) { 666 667 DPRINTF(("%s: inner source address %s doesn't " 668 "correspond to expected proxy source %s, " 669 "SA %s/%08lx\n", __func__, 670 ip6_sprintf(ip6buf, &ip6n.ip6_src), 671 ipsec_address(&saidx->proxy), 672 ipsec_address(&saidx->dst), 673 (u_long) ntohl(sav->spi))); 674 675 IPSEC_ISTAT(sproto, espstat.esps_pdrops, 676 ahstat.ahs_pdrops, ipcompstat.ipcomps_pdrops); 677 error = EACCES; 678 goto bad; 679 } 680 } 681#endif /*XXX*/ 682 683 /* 684 * Record what we've done to the packet (under what SA it was 685 * processed). If we've been passed an mtag, it means the packet 686 * was already processed by an ethernet/crypto combo card and 687 * thus has a tag attached with all the right information, but 688 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to 689 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type. 690 */ 691 if (mt == NULL && sproto != IPPROTO_IPCOMP) { 692 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE, 693 sizeof(struct tdb_ident), M_NOWAIT); 694 if (mtag == NULL) { 695 DPRINTF(("%s: failed to get tag\n", __func__)); 696 IPSEC_ISTAT(sproto, espstat.esps_hdrops, 697 ahstat.ahs_hdrops, ipcompstat.ipcomps_hdrops); 698 error = ENOMEM; 699 goto bad; 700 } 701 702 tdbi = (struct tdb_ident *)(mtag + 1); 703 bcopy(&saidx->dst, &tdbi->dst, sizeof(union sockaddr_union)); 704 tdbi->proto = sproto; 705 tdbi->spi = sav->spi; 706 707 m_tag_prepend(m, mtag); 708 } else { 709 if (mt != NULL) 710 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE; 711 /* XXX do we need to mark m_flags??? */ 712 } 713 714 key_sa_recordxfer(sav, m); 715 716 /* Retrieve new protocol */ 717 m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &nxt8); 718 719 /* 720 * See the end of ip6_input for this logic. 721 * IPPROTO_IPV[46] case will be processed just like other ones 722 */ 723 nest = 0; 724 nxt = nxt8; 725 while (nxt != IPPROTO_DONE) { 726 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 727 ip6stat.ip6s_toomanyhdr++; 728 error = EINVAL; 729 goto bad; 730 } 731 732 /* 733 * Protection against faulty packet - there should be 734 * more sanity checks in header chain processing. 735 */ 736 if (m->m_pkthdr.len < skip) { 737 ip6stat.ip6s_tooshort++; 738 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 739 error = EINVAL; 740 goto bad; 741 } 742 /* 743 * Enforce IPsec policy checking if we are seeing last header. 744 * note that we do not visit this with protocols with pcb layer 745 * code - like udp/tcp/raw ip. 746 */ 747 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 748 ipsec6_in_reject(m, NULL)) { 749 error = EINVAL; 750 goto bad; 751 } 752 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &skip, nxt); 753 } 754 return 0; 755bad: 756 if (m) 757 m_freem(m); 758 return error; 759} 760 761void 762esp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 763{ 764 if (sa->sa_family != AF_INET6 || 765 sa->sa_len != sizeof(struct sockaddr_in6)) 766 return; 767 if ((unsigned)cmd >= PRC_NCMDS) 768 return; 769 770 /* if the parameter is from icmp6, decode it. */ 771 if (d != NULL) { 772 struct ip6ctlparam *ip6cp = (struct ip6ctlparam *)d; 773 struct mbuf *m = ip6cp->ip6c_m; 774 int off = ip6cp->ip6c_off; 775 776 struct ip6ctlparam ip6cp1; 777 778 /* 779 * Notify the error to all possible sockets via pfctlinput2. 780 * Since the upper layer information (such as protocol type, 781 * source and destination ports) is embedded in the encrypted 782 * data and might have been cut, we can't directly call 783 * an upper layer ctlinput function. However, the pcbnotify 784 * function will consider source and destination addresses 785 * as well as the flow info value, and may be able to find 786 * some PCB that should be notified. 787 * Although pfctlinput2 will call esp6_ctlinput(), there is 788 * no possibility of an infinite loop of function calls, 789 * because we don't pass the inner IPv6 header. 790 */ 791 bzero(&ip6cp1, sizeof(ip6cp1)); 792 ip6cp1.ip6c_src = ip6cp->ip6c_src; 793 pfctlinput2(cmd, sa, (void *)&ip6cp1); 794 795 /* 796 * Then go to special cases that need ESP header information. 797 * XXX: We assume that when ip6 is non NULL, 798 * M and OFF are valid. 799 */ 800 801 if (cmd == PRC_MSGSIZE) { 802 struct secasvar *sav; 803 u_int32_t spi; 804 int valid; 805 806 /* check header length before using m_copydata */ 807 if (m->m_pkthdr.len < off + sizeof (struct esp)) 808 return; 809 m_copydata(m, off + offsetof(struct esp, esp_spi), 810 sizeof(u_int32_t), (caddr_t) &spi); 811 /* 812 * Check to see if we have a valid SA corresponding to 813 * the address in the ICMP message payload. 814 */ 815 sav = KEY_ALLOCSA((union sockaddr_union *)sa, 816 IPPROTO_ESP, spi); 817 valid = (sav != NULL); 818 if (sav) 819 KEY_FREESAV(&sav); 820 821 /* XXX Further validation? */ 822 823 /* 824 * Depending on whether the SA is "valid" and 825 * routing table size (mtudisc_{hi,lo}wat), we will: 826 * - recalcurate the new MTU and create the 827 * corresponding routing entry, or 828 * - ignore the MTU change notification. 829 */ 830 icmp6_mtudisc_update(ip6cp, valid); 831 } 832 } else { 833 /* we normally notify any pcb here */ 834 } 835} 836#endif /* INET6 */ 837