1 /* $NetBSD: ipsec_output.c,v 1.38 2012/01/10 20:01:57 drochner Exp $ */ 2 3 /*- 4 * Copyright (c) 2002, 2003 Sam Leffler, Errno Consulting 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 * $FreeBSD: /repoman/r/ncvs/src/sys/netipsec/ipsec_output.c,v 1.3.2.2 2003/03/28 20:32:53 sam Exp $ 29 */ 30 31 #include <sys/cdefs.h> 32 __KERNEL_RCSID(0, "$NetBSD: ipsec_output.c,v 1.38 2012/01/10 20:01:57 drochner Exp $"); 33 34 /* 35 * IPsec output processing. 36 */ 37 #include "opt_inet.h" 38 #ifdef __FreeBSD__ 39 #include "opt_inet6.h" 40 #endif 41 #include "opt_ipsec.h" 42 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/mbuf.h> 46 #include <sys/domain.h> 47 #include <sys/protosw.h> 48 #include <sys/socket.h> 49 #include <sys/errno.h> 50 #include <sys/syslog.h> 51 52 #include <net/if.h> 53 #include <net/route.h> 54 55 #include <netinet/in.h> 56 #include <netinet/in_systm.h> 57 #include <netinet/ip.h> 58 #include <netinet/ip_var.h> 59 #include <netinet/in_var.h> 60 #include <netinet/ip_ecn.h> 61 #ifdef INET6 62 # ifdef __FreeBSD__ 63 # include <netinet6/ip6_ecn.h> 64 # endif 65 #endif 66 67 #include <netinet/ip6.h> 68 #ifdef INET6 69 #include <netinet6/ip6_var.h> 70 #endif 71 #include <netinet/in_pcb.h> 72 #ifdef INET6 73 #include <netinet/icmp6.h> 74 #endif 75 #ifdef IPSEC_NAT_T 76 #include <netinet/udp.h> 77 #endif 78 79 #include <netipsec/ipsec.h> 80 #include <netipsec/ipsec_var.h> 81 #include <netipsec/ipsec_private.h> 82 #ifdef INET6 83 #include <netipsec/ipsec6.h> 84 #endif 85 #include <netipsec/ah_var.h> 86 #include <netipsec/esp_var.h> 87 #include <netipsec/ipcomp_var.h> 88 89 #include <netipsec/xform.h> 90 91 #include <netipsec/key.h> 92 #include <netipsec/keydb.h> 93 #include <netipsec/key_debug.h> 94 #include <netipsec/ipsec_osdep.h> 95 96 #include <net/net_osdep.h> /* ovbcopy() in ipsec6_encapsulate() */ 97 98 99 /* 100 * Add a IPSEC_OUT_DONE tag to mark that we have finished the ipsec processing 101 * It will be used by ip{,6}_output to check if we have already or not 102 * processed this packet. 103 */ 104 static int 105 ipsec_register_done(struct mbuf *m, int * error) 106 { 107 struct m_tag *mtag; 108 109 mtag = m_tag_get(PACKET_TAG_IPSEC_OUT_DONE, 0, M_NOWAIT); 110 if (mtag == NULL) { 111 DPRINTF(("ipsec_register_done: could not get packet tag\n")); 112 *error = ENOMEM; 113 return -1; 114 } 115 116 m_tag_prepend(m, mtag); 117 return 0; 118 } 119 120 static int 121 ipsec_reinject_ipstack(struct mbuf *m, int af) 122 { 123 #ifdef INET 124 struct ip * ip; 125 #endif /* INET */ 126 #if defined(INET) || defined(INET6) 127 int rv; 128 #endif 129 130 switch (af) { 131 #ifdef INET 132 case AF_INET: 133 ip = mtod(m, struct ip *); 134 #ifdef __FreeBSD__ 135 /* FreeBSD ip_output() expects ip_len, ip_off in host endian */ 136 ip->ip_len = ntohs(ip->ip_len); 137 ip->ip_off = ntohs(ip->ip_off); 138 #endif /* __FreeBSD_ */ 139 KERNEL_LOCK(1, NULL); 140 rv = ip_output(m, NULL, NULL, IP_RAWOUTPUT|IP_NOIPNEWID, 141 NULL, NULL); 142 KERNEL_UNLOCK_ONE(NULL); 143 return rv; 144 145 #endif /* INET */ 146 #ifdef INET6 147 case AF_INET6: 148 /* 149 * We don't need massage, IPv6 header fields are always in 150 * net endian. 151 */ 152 KERNEL_LOCK(1, NULL); 153 rv = ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL); 154 KERNEL_UNLOCK_ONE(NULL); 155 return rv; 156 #endif /* INET6 */ 157 } 158 159 panic("ipsec_reinject_ipstack : iunknown protocol family %u\n", af); 160 return -1; /* NOTREACHED */ 161 } 162 163 int 164 ipsec_process_done(struct mbuf *m, struct ipsecrequest *isr) 165 { 166 struct secasvar *sav; 167 struct secasindex *saidx; 168 int error; 169 #ifdef INET 170 struct ip * ip; 171 #endif /* INET */ 172 #ifdef INET6 173 struct ip6_hdr * ip6; 174 #endif /* INET6 */ 175 #ifdef IPSEC_NAT_T 176 struct mbuf * mo; 177 struct udphdr *udp = NULL; 178 uint64_t * data = NULL; 179 int hlen, roff; 180 #endif /* IPSEC_NAT_T */ 181 182 IPSEC_SPLASSERT_SOFTNET("ipsec_process_done"); 183 184 IPSEC_ASSERT(m != NULL, ("ipsec_process_done: null mbuf")); 185 IPSEC_ASSERT(isr != NULL, ("ipsec_process_done: null ISR")); 186 sav = isr->sav; 187 IPSEC_ASSERT(sav != NULL, ("ipsec_process_done: null SA")); 188 IPSEC_ASSERT(sav->sah != NULL, ("ipsec_process_done: null SAH")); 189 190 saidx = &sav->sah->saidx; 191 192 #ifdef IPSEC_NAT_T 193 if(sav->natt_type != 0) { 194 ip = mtod(m, struct ip *); 195 196 hlen = sizeof(struct udphdr); 197 if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE) 198 hlen += sizeof(uint64_t); 199 200 mo = m_makespace(m, sizeof(struct ip), hlen, &roff); 201 if (mo == NULL) { 202 DPRINTF(("ipsec_process_done : failed to inject" 203 "%u byte UDP for SA %s/%08lx\n", 204 hlen, ipsec_address(&saidx->dst), 205 (u_long) ntohl(sav->spi))); 206 error = ENOBUFS; 207 goto bad; 208 } 209 210 udp = (struct udphdr*) (mtod(mo, char*) + roff); 211 data = (uint64_t*) (udp + 1); 212 213 if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE) 214 *data = 0; /* NON-IKE Marker */ 215 216 if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE) 217 udp->uh_sport = htons(UDP_ENCAP_ESPINUDP_PORT); 218 else 219 udp->uh_sport = key_portfromsaddr(&saidx->src); 220 221 udp->uh_dport = key_portfromsaddr(&saidx->dst); 222 udp->uh_sum = 0; 223 udp->uh_ulen = htons(m->m_pkthdr.len - (ip->ip_hl << 2)); 224 } 225 #endif /* IPSEC_NAT_T */ 226 227 switch (saidx->dst.sa.sa_family) { 228 #ifdef INET 229 case AF_INET: 230 /* Fix the header length, for AH processing. */ 231 ip = mtod(m, struct ip *); 232 ip->ip_len = htons(m->m_pkthdr.len); 233 #ifdef IPSEC_NAT_T 234 if (sav->natt_type != 0) 235 ip->ip_p = IPPROTO_UDP; 236 #endif /* IPSEC_NAT_T */ 237 break; 238 #endif /* INET */ 239 #ifdef INET6 240 case AF_INET6: 241 /* Fix the header length, for AH processing. */ 242 if (m->m_pkthdr.len < sizeof (struct ip6_hdr)) { 243 error = ENXIO; 244 goto bad; 245 } 246 if (m->m_pkthdr.len - sizeof (struct ip6_hdr) > IPV6_MAXPACKET) { 247 /* No jumbogram support. */ 248 error = ENXIO; /*?*/ 249 goto bad; 250 } 251 ip6 = mtod(m, struct ip6_hdr *); 252 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 253 #ifdef IPSEC_NAT_T 254 if (sav->natt_type != 0) 255 ip6->ip6_nxt = IPPROTO_UDP; 256 #endif /* IPSEC_NAT_T */ 257 break; 258 #endif /* INET6 */ 259 default: 260 DPRINTF(("ipsec_process_done: unknown protocol family %u\n", 261 saidx->dst.sa.sa_family)); 262 error = ENXIO; 263 goto bad; 264 } 265 266 key_sa_recordxfer(sav, m); 267 268 /* 269 * If there's another (bundled) SA to apply, do so. 270 * Note that this puts a burden on the kernel stack size. 271 * If this is a problem we'll need to introduce a queue 272 * to set the packet on so we can unwind the stack before 273 * doing further processing. 274 */ 275 if (isr->next) { 276 IPSEC_STATINC(IPSEC_STAT_OUT_BUNDLESA); 277 switch ( saidx->dst.sa.sa_family ) { 278 #ifdef INET 279 case AF_INET: 280 return ipsec4_process_packet(m, isr->next, 0,0); 281 #endif /* INET */ 282 #ifdef INET6 283 case AF_INET6: 284 return ipsec6_process_packet(m,isr->next); 285 #endif /* INET6 */ 286 default : 287 DPRINTF(("ipsec_process_done: unknown protocol family %u\n", 288 saidx->dst.sa.sa_family)); 289 error = ENXIO; 290 goto bad; 291 } 292 } 293 294 /* 295 * We're done with IPsec processing, 296 * mark that we have already processed the packet 297 * transmit it packet using the appropriate network protocol (IP or IPv6). 298 */ 299 300 if (ipsec_register_done(m, &error) < 0) 301 goto bad; 302 303 return ipsec_reinject_ipstack(m, saidx->dst.sa.sa_family); 304 bad: 305 m_freem(m); 306 KEY_FREESAV(&sav); 307 return (error); 308 } 309 310 /* 311 * ipsec_nextisr can return : 312 * - isr == NULL and error != 0 => something is bad : the packet must be 313 * discarded 314 * - isr == NULL and error == 0 => no more rules to apply, ipsec processing 315 * is done, reinject it in ip stack 316 * - isr != NULL (error == 0) => we need to apply one rule to the packet 317 */ 318 static struct ipsecrequest * 319 ipsec_nextisr( 320 struct mbuf *m, 321 struct ipsecrequest *isr, 322 int af, 323 struct secasindex *saidx, 324 int *error 325 ) 326 { 327 #define IPSEC_OSTAT(x, y, z) \ 328 do { \ 329 switch (isr->saidx.proto) { \ 330 case IPPROTO_ESP: \ 331 ESP_STATINC(x); \ 332 break; \ 333 case IPPROTO_AH: \ 334 AH_STATINC(y); \ 335 break; \ 336 default: \ 337 IPCOMP_STATINC(z); \ 338 break; \ 339 } \ 340 } while (/*CONSTCOND*/0) 341 342 struct secasvar *sav; 343 344 IPSEC_SPLASSERT_SOFTNET("ipsec_nextisr"); 345 IPSEC_ASSERT(af == AF_INET || af == AF_INET6, 346 ("ipsec_nextisr: invalid address family %u", af)); 347 again: 348 /* 349 * Craft SA index to search for proper SA. Note that 350 * we only fillin unspecified SA peers for transport 351 * mode; for tunnel mode they must already be filled in. 352 */ 353 *saidx = isr->saidx; 354 if (isr->saidx.mode == IPSEC_MODE_TRANSPORT) { 355 /* Fillin unspecified SA peers only for transport mode */ 356 if (af == AF_INET) { 357 struct sockaddr_in *sin; 358 struct ip *ip = mtod(m, struct ip *); 359 360 if (saidx->src.sa.sa_len == 0) { 361 sin = &saidx->src.sin; 362 sin->sin_len = sizeof(*sin); 363 sin->sin_family = AF_INET; 364 sin->sin_port = IPSEC_PORT_ANY; 365 sin->sin_addr = ip->ip_src; 366 } 367 if (saidx->dst.sa.sa_len == 0) { 368 sin = &saidx->dst.sin; 369 sin->sin_len = sizeof(*sin); 370 sin->sin_family = AF_INET; 371 sin->sin_port = IPSEC_PORT_ANY; 372 sin->sin_addr = ip->ip_dst; 373 } 374 } else { 375 struct sockaddr_in6 *sin6; 376 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 377 378 if (saidx->src.sin6.sin6_len == 0) { 379 sin6 = (struct sockaddr_in6 *)&saidx->src; 380 sin6->sin6_len = sizeof(*sin6); 381 sin6->sin6_family = AF_INET6; 382 sin6->sin6_port = IPSEC_PORT_ANY; 383 sin6->sin6_addr = ip6->ip6_src; 384 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) { 385 /* fix scope id for comparing SPD */ 386 sin6->sin6_addr.s6_addr16[1] = 0; 387 sin6->sin6_scope_id = 388 ntohs(ip6->ip6_src.s6_addr16[1]); 389 } 390 } 391 if (saidx->dst.sin6.sin6_len == 0) { 392 sin6 = (struct sockaddr_in6 *)&saidx->dst; 393 sin6->sin6_len = sizeof(*sin6); 394 sin6->sin6_family = AF_INET6; 395 sin6->sin6_port = IPSEC_PORT_ANY; 396 sin6->sin6_addr = ip6->ip6_dst; 397 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) { 398 /* fix scope id for comparing SPD */ 399 sin6->sin6_addr.s6_addr16[1] = 0; 400 sin6->sin6_scope_id = 401 ntohs(ip6->ip6_dst.s6_addr16[1]); 402 } 403 } 404 } 405 } 406 407 /* 408 * Lookup SA and validate it. 409 */ 410 *error = key_checkrequest(isr, saidx); 411 if (*error != 0) { 412 /* 413 * IPsec processing is required, but no SA found. 414 * I assume that key_acquire() had been called 415 * to get/establish the SA. Here I discard 416 * this packet because it is responsibility for 417 * upper layer to retransmit the packet. 418 */ 419 IPSEC_STATINC(IPSEC_STAT_OUT_NOSA); 420 goto bad; 421 } 422 sav = isr->sav; 423 /* sav may be NULL here if we have an USE rule */ 424 if (sav == NULL) { 425 IPSEC_ASSERT(ipsec_get_reqlevel(isr) == IPSEC_LEVEL_USE, 426 ("ipsec_nextisr: no SA found, but required; level %u", 427 ipsec_get_reqlevel(isr))); 428 isr = isr->next; 429 /* 430 * No more rules to apply, return NULL isr and no error 431 * It can happen when the last rules are USE rules 432 * */ 433 if (isr == NULL) { 434 *error = 0; 435 return isr; 436 } 437 goto again; 438 } 439 440 /* 441 * Check system global policy controls. 442 */ 443 if ((isr->saidx.proto == IPPROTO_ESP && !esp_enable) || 444 (isr->saidx.proto == IPPROTO_AH && !ah_enable) || 445 (isr->saidx.proto == IPPROTO_IPCOMP && !ipcomp_enable)) { 446 DPRINTF(("ipsec_nextisr: IPsec outbound packet dropped due" 447 " to policy (check your sysctls)\n")); 448 IPSEC_OSTAT(ESP_STAT_PDROPS, AH_STAT_PDROPS, 449 IPCOMP_STAT_PDROPS); 450 *error = EHOSTUNREACH; 451 goto bad; 452 } 453 454 /* 455 * Sanity check the SA contents for the caller 456 * before they invoke the xform output method. 457 */ 458 if (sav->tdb_xform == NULL) { 459 DPRINTF(("ipsec_nextisr: no transform for SA\n")); 460 IPSEC_OSTAT(ESP_STAT_NOXFORM, AH_STAT_NOXFORM, 461 IPCOMP_STAT_NOXFORM); 462 *error = EHOSTUNREACH; 463 goto bad; 464 } 465 return isr; 466 bad: 467 IPSEC_ASSERT(*error != 0, ("ipsec_nextisr: error return w/ no error code")); 468 return NULL; 469 #undef IPSEC_OSTAT 470 } 471 472 #ifdef INET 473 /* 474 * IPsec output logic for IPv4. 475 */ 476 int 477 ipsec4_process_packet( 478 struct mbuf *m, 479 struct ipsecrequest *isr, 480 int flags, 481 int tunalready 482 ) 483 { 484 struct secasindex saidx; 485 struct secasvar *sav; 486 struct ip *ip; 487 int s, error, i, off; 488 489 IPSEC_ASSERT(m != NULL, ("ipsec4_process_packet: null mbuf")); 490 IPSEC_ASSERT(isr != NULL, ("ipsec4_process_packet: null isr")); 491 492 s = splsoftnet(); /* insure SA contents don't change */ 493 494 isr = ipsec_nextisr(m, isr, AF_INET, &saidx, &error); 495 if (isr == NULL) { 496 if (error != 0) { 497 goto bad; 498 } else { 499 if (ipsec_register_done(m, &error) < 0) 500 goto bad; 501 502 splx(s); 503 return ipsec_reinject_ipstack(m, AF_INET); 504 } 505 } 506 507 sav = isr->sav; 508 if (!tunalready) { 509 union sockaddr_union *dst = &sav->sah->saidx.dst; 510 int setdf; 511 512 /* 513 * Collect IP_DF state from the outer header. 514 */ 515 if (dst->sa.sa_family == AF_INET) { 516 if (m->m_len < sizeof (struct ip) && 517 (m = m_pullup(m, sizeof (struct ip))) == NULL) { 518 error = ENOBUFS; 519 goto bad; 520 } 521 ip = mtod(m, struct ip *); 522 /* Honor system-wide control of how to handle IP_DF */ 523 switch (ip4_ipsec_dfbit) { 524 case 0: /* clear in outer header */ 525 case 1: /* set in outer header */ 526 setdf = ip4_ipsec_dfbit; 527 break; 528 default: /* propagate to outer header */ 529 setdf = ip->ip_off; 530 #ifndef __FreeBSD__ 531 /* On FreeBSD, ip_off and ip_len assumed in host endian. */ 532 setdf = ntohs(setdf); 533 #endif 534 setdf = htons(setdf & IP_DF); 535 break; 536 } 537 } else { 538 ip = NULL; /* keep compiler happy */ 539 setdf = 0; 540 } 541 /* Do the appropriate encapsulation, if necessary */ 542 if (isr->saidx.mode == IPSEC_MODE_TUNNEL || /* Tunnel requ'd */ 543 dst->sa.sa_family != AF_INET || /* PF mismatch */ 544 #if 0 545 (sav->flags & SADB_X_SAFLAGS_TUNNEL) || /* Tunnel requ'd */ 546 sav->tdb_xform->xf_type == XF_IP4 || /* ditto */ 547 #endif 548 (dst->sa.sa_family == AF_INET && /* Proxy */ 549 dst->sin.sin_addr.s_addr != INADDR_ANY && 550 dst->sin.sin_addr.s_addr != ip->ip_dst.s_addr)) { 551 struct mbuf *mp; 552 553 /* Fix IPv4 header checksum and length */ 554 if (m->m_len < sizeof (struct ip) && 555 (m = m_pullup(m, sizeof (struct ip))) == NULL) { 556 error = ENOBUFS; 557 goto bad; 558 } 559 ip = mtod(m, struct ip *); 560 ip->ip_len = htons(m->m_pkthdr.len); 561 ip->ip_sum = 0; 562 ip->ip_sum = in_cksum(m, ip->ip_hl << 2); 563 564 /* Encapsulate the packet */ 565 error = ipip_output(m, isr, &mp, 0, 0); 566 if (mp == NULL && !error) { 567 /* Should never happen. */ 568 DPRINTF(("ipsec4_process_packet: ipip_output " 569 "returns no mbuf and no error!")); 570 error = EFAULT; 571 } 572 if (error) { 573 if (mp) { 574 /* XXX: Should never happen! */ 575 m_freem(mp); 576 } 577 m = NULL; /* ipip_output() already freed it */ 578 goto bad; 579 } 580 m = mp, mp = NULL; 581 /* 582 * ipip_output clears IP_DF in the new header. If 583 * we need to propagate IP_DF from the outer header, 584 * then we have to do it here. 585 * 586 * XXX shouldn't assume what ipip_output does. 587 */ 588 if (dst->sa.sa_family == AF_INET && setdf) { 589 if (m->m_len < sizeof (struct ip) && 590 (m = m_pullup(m, sizeof (struct ip))) == NULL) { 591 error = ENOBUFS; 592 goto bad; 593 } 594 ip = mtod(m, struct ip *); 595 ip->ip_off |= IP_OFF_CONVERT(IP_DF); 596 } 597 } 598 } 599 600 /* 601 * Dispatch to the appropriate IPsec transform logic. The 602 * packet will be returned for transmission after crypto 603 * processing, etc. are completed. For encapsulation we 604 * bypass this call because of the explicit call done above 605 * (necessary to deal with IP_DF handling for IPv4). 606 * 607 * NB: m & sav are ``passed to caller'' who's reponsible for 608 * for reclaiming their resources. 609 */ 610 if (sav->tdb_xform->xf_type != XF_IP4) { 611 union sockaddr_union *dst = &sav->sah->saidx.dst; 612 if (dst->sa.sa_family == AF_INET) { 613 ip = mtod(m, struct ip *); 614 i = ip->ip_hl << 2; 615 off = offsetof(struct ip, ip_p); 616 } else { 617 i = sizeof(struct ip6_hdr); 618 off = offsetof(struct ip6_hdr, ip6_nxt); 619 } 620 error = (*sav->tdb_xform->xf_output)(m, isr, NULL, i, off); 621 } else { 622 error = ipsec_process_done(m, isr); 623 } 624 splx(s); 625 return error; 626 bad: 627 splx(s); 628 if (m) 629 m_freem(m); 630 return error; 631 } 632 #endif 633 634 #ifdef INET6 635 static void 636 compute_ipsec_pos(struct mbuf *m, int *i, int *off) 637 { 638 int nxt; 639 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr*); 640 struct ip6_ext ip6e; 641 int dstopt = 0; 642 643 *i = sizeof(struct ip6_hdr); 644 *off = offsetof(struct ip6_hdr, ip6_nxt); 645 nxt = ip6->ip6_nxt; 646 647 /* 648 * chase mbuf chain to find the appropriate place to 649 * put AH/ESP/IPcomp header. 650 * IPv6 hbh dest1 rthdr ah* [esp* dest2 payload] 651 */ 652 do { 653 switch (nxt) { 654 case IPPROTO_AH: 655 case IPPROTO_ESP: 656 case IPPROTO_IPCOMP: 657 /* 658 * we should not skip security header added 659 * beforehand. 660 */ 661 return; 662 663 case IPPROTO_HOPOPTS: 664 case IPPROTO_DSTOPTS: 665 case IPPROTO_ROUTING: 666 /* 667 * if we see 2nd destination option header, 668 * we should stop there. 669 */ 670 if (nxt == IPPROTO_DSTOPTS && dstopt) 671 return; 672 673 if (nxt == IPPROTO_DSTOPTS) { 674 /* 675 * seen 1st or 2nd destination option. 676 * next time we see one, it must be 2nd. 677 */ 678 dstopt = 1; 679 } else if (nxt == IPPROTO_ROUTING) { 680 /* 681 * if we see destionation option next 682 * time, it must be dest2. 683 */ 684 dstopt = 2; 685 } 686 687 /* skip this header */ 688 m_copydata(m, *i, sizeof(ip6e), &ip6e); 689 nxt = ip6e.ip6e_nxt; 690 *off = *i + offsetof(struct ip6_ext, ip6e_nxt); 691 /* 692 * we will never see nxt == IPPROTO_AH 693 * so it is safe to omit AH case. 694 */ 695 *i += (ip6e.ip6e_len + 1) << 3; 696 break; 697 default: 698 return; 699 } 700 } while (*i < m->m_pkthdr.len); 701 } 702 703 static int 704 in6_sa_equal_addrwithscope(const struct sockaddr_in6 *sa, const struct in6_addr *ia) 705 { 706 struct in6_addr ia2; 707 708 memcpy(&ia2, &sa->sin6_addr, sizeof(ia2)); 709 if (IN6_IS_SCOPE_LINKLOCAL(&sa->sin6_addr)) 710 ia2.s6_addr16[1] = htons(sa->sin6_scope_id); 711 712 return IN6_ARE_ADDR_EQUAL(ia, &ia2); 713 } 714 715 int 716 ipsec6_process_packet( 717 struct mbuf *m, 718 struct ipsecrequest *isr 719 ) 720 { 721 struct secasindex saidx; 722 struct secasvar *sav; 723 struct ip6_hdr *ip6; 724 int s, error, i, off; 725 union sockaddr_union *dst; 726 727 IPSEC_ASSERT(m != NULL, ("ipsec6_process_packet: null mbuf")); 728 IPSEC_ASSERT(isr != NULL, ("ipsec6_process_packet: null isr")); 729 730 s = splsoftnet(); /* insure SA contents don't change */ 731 732 isr = ipsec_nextisr(m, isr, AF_INET6, &saidx, &error); 733 if (isr == NULL) { 734 if (error != 0) { 735 /* XXX Should we send a notification ? */ 736 goto bad; 737 } else { 738 if (ipsec_register_done(m, &error) < 0) 739 goto bad; 740 741 splx(s); 742 return ipsec_reinject_ipstack(m, AF_INET6); 743 } 744 } 745 746 sav = isr->sav; 747 dst = &sav->sah->saidx.dst; 748 749 ip6 = mtod(m, struct ip6_hdr *); /* XXX */ 750 751 /* Do the appropriate encapsulation, if necessary */ 752 if (isr->saidx.mode == IPSEC_MODE_TUNNEL || /* Tunnel requ'd */ 753 dst->sa.sa_family != AF_INET6 || /* PF mismatch */ 754 ((dst->sa.sa_family == AF_INET6) && 755 (!IN6_IS_ADDR_UNSPECIFIED(&dst->sin6.sin6_addr)) && 756 (!in6_sa_equal_addrwithscope(&dst->sin6, 757 &ip6->ip6_dst)))) { 758 struct mbuf *mp; 759 760 /* Fix IPv6 header payload length. */ 761 if (m->m_len < sizeof(struct ip6_hdr)) 762 if ((m = m_pullup(m,sizeof(struct ip6_hdr))) == NULL) 763 return ENOBUFS; 764 765 if (m->m_pkthdr.len - sizeof(*ip6) > IPV6_MAXPACKET) { 766 /* No jumbogram support. */ 767 m_freem(m); 768 return ENXIO; /*XXX*/ 769 } 770 771 ip6 = mtod(m, struct ip6_hdr *); 772 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6)); 773 774 /* Encapsulate the packet */ 775 error = ipip_output(m, isr, &mp, 0, 0); 776 if (mp == NULL && !error) { 777 /* Should never happen. */ 778 DPRINTF(("ipsec6_process_packet: ipip_output " 779 "returns no mbuf and no error!")); 780 error = EFAULT; 781 } 782 783 if (error) { 784 if (mp) { 785 /* XXX: Should never happen! */ 786 m_freem(mp); 787 } 788 m = NULL; /* ipip_output() already freed it */ 789 goto bad; 790 } 791 792 m = mp; 793 mp = NULL; 794 } 795 796 if (dst->sa.sa_family == AF_INET) { 797 struct ip *ip; 798 ip = mtod(m, struct ip *); 799 i = ip->ip_hl << 2; 800 off = offsetof(struct ip, ip_p); 801 } else { 802 compute_ipsec_pos(m, &i, &off); 803 } 804 error = (*sav->tdb_xform->xf_output)(m, isr, NULL, i, off); 805 splx(s); 806 return error; 807 bad: 808 splx(s); 809 if (m) 810 m_freem(m); 811 return error; 812 } 813 #endif /*INET6*/ 814