ipsec_output.c revision 264520
1/*- 2 * Copyright (c) 2002, 2003 Sam Leffler, Errno Consulting 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD: head/sys/netipsec/ipsec_output.c 264520 2014-04-16 05:31:54Z ae $ 27 */ 28 29/* 30 * IPsec output processing. 31 */ 32#include "opt_inet.h" 33#include "opt_inet6.h" 34#include "opt_ipsec.h" 35#include "opt_enc.h" 36 37#include <sys/param.h> 38#include <sys/systm.h> 39#include <sys/mbuf.h> 40#include <sys/domain.h> 41#include <sys/protosw.h> 42#include <sys/socket.h> 43#include <sys/errno.h> 44#include <sys/syslog.h> 45 46#include <net/if.h> 47#include <net/if_var.h> 48#include <net/pfil.h> 49#include <net/route.h> 50#include <net/vnet.h> 51 52#include <netinet/in.h> 53#include <netinet/in_systm.h> 54#include <netinet/ip.h> 55#include <netinet/ip_var.h> 56#include <netinet/in_var.h> 57#include <netinet/ip_ecn.h> 58#ifdef INET6 59#include <netinet6/ip6_ecn.h> 60#endif 61 62#include <netinet/ip6.h> 63#ifdef INET6 64#include <netinet6/ip6_var.h> 65#endif 66#include <netinet/in_pcb.h> 67#ifdef INET6 68#include <netinet/icmp6.h> 69#endif 70 71#include <netipsec/ipsec.h> 72#ifdef INET6 73#include <netipsec/ipsec6.h> 74#endif 75#include <netipsec/ah_var.h> 76#include <netipsec/esp_var.h> 77#include <netipsec/ipcomp_var.h> 78 79#include <netipsec/xform.h> 80 81#include <netipsec/key.h> 82#include <netipsec/keydb.h> 83#include <netipsec/key_debug.h> 84 85#include <machine/in_cksum.h> 86 87#ifdef IPSEC_NAT_T 88#include <netinet/udp.h> 89#endif 90 91#ifdef DEV_ENC 92#include <net/if_enc.h> 93#endif 94 95 96int 97ipsec_process_done(struct mbuf *m, struct ipsecrequest *isr) 98{ 99 struct tdb_ident *tdbi; 100 struct m_tag *mtag; 101 struct secasvar *sav; 102 struct secasindex *saidx; 103 int error; 104 105 IPSEC_ASSERT(m != NULL, ("null mbuf")); 106 IPSEC_ASSERT(isr != NULL, ("null ISR")); 107 sav = isr->sav; 108 IPSEC_ASSERT(sav != NULL, ("null SA")); 109 IPSEC_ASSERT(sav->sah != NULL, ("null SAH")); 110 111 saidx = &sav->sah->saidx; 112 switch (saidx->dst.sa.sa_family) { 113#ifdef INET 114 case AF_INET: 115 /* Fix the header length, for AH processing. */ 116 mtod(m, struct ip *)->ip_len = htons(m->m_pkthdr.len); 117 break; 118#endif /* INET */ 119#ifdef INET6 120 case AF_INET6: 121 /* Fix the header length, for AH processing. */ 122 if (m->m_pkthdr.len < sizeof (struct ip6_hdr)) { 123 error = ENXIO; 124 goto bad; 125 } 126 if (m->m_pkthdr.len - sizeof (struct ip6_hdr) > IPV6_MAXPACKET) { 127 /* No jumbogram support. */ 128 error = ENXIO; /*?*/ 129 goto bad; 130 } 131 mtod(m, struct ip6_hdr *)->ip6_plen = 132 htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 133 break; 134#endif /* INET6 */ 135 default: 136 DPRINTF(("%s: unknown protocol family %u\n", __func__, 137 saidx->dst.sa.sa_family)); 138 error = ENXIO; 139 goto bad; 140 } 141 142 /* 143 * Add a record of what we've done or what needs to be done to the 144 * packet. 145 */ 146 mtag = m_tag_get(PACKET_TAG_IPSEC_OUT_DONE, 147 sizeof(struct tdb_ident), M_NOWAIT); 148 if (mtag == NULL) { 149 DPRINTF(("%s: could not get packet tag\n", __func__)); 150 error = ENOMEM; 151 goto bad; 152 } 153 154 tdbi = (struct tdb_ident *)(mtag + 1); 155 tdbi->dst = saidx->dst; 156 tdbi->proto = saidx->proto; 157 tdbi->spi = sav->spi; 158 m_tag_prepend(m, mtag); 159 160 /* 161 * If there's another (bundled) SA to apply, do so. 162 * Note that this puts a burden on the kernel stack size. 163 * If this is a problem we'll need to introduce a queue 164 * to set the packet on so we can unwind the stack before 165 * doing further processing. 166 */ 167 if (isr->next) { 168 IPSECSTAT_INC(ips_out_bundlesa); 169 /* XXX-BZ currently only support same AF bundles. */ 170 switch (saidx->dst.sa.sa_family) { 171#ifdef INET 172 case AF_INET: 173 return ipsec4_process_packet(m, isr->next, 0, 0); 174 /* NOTREACHED */ 175#endif 176#ifdef notyet 177#ifdef INET6 178 case AF_INET6: 179 /* XXX */ 180 ipsec6_output_trans() 181 ipsec6_output_tunnel() 182 /* NOTREACHED */ 183#endif /* INET6 */ 184#endif 185 default: 186 DPRINTF(("%s: unknown protocol family %u\n", __func__, 187 saidx->dst.sa.sa_family)); 188 error = ENXIO; 189 goto bad; 190 } 191 } 192 key_sa_recordxfer(sav, m); /* record data transfer */ 193 194 /* 195 * We're done with IPsec processing, transmit the packet using the 196 * appropriate network protocol (IP or IPv6). SPD lookup will be 197 * performed again there. 198 */ 199 switch (saidx->dst.sa.sa_family) { 200#ifdef INET 201 case AF_INET: 202#ifdef IPSEC_NAT_T 203 /* 204 * If NAT-T is enabled, now that all IPsec processing is done 205 * insert UDP encapsulation header after IP header. 206 */ 207 if (sav->natt_type) { 208 struct ip *ip = mtod(m, struct ip *); 209 const int hlen = (ip->ip_hl << 2); 210 int size, off; 211 struct mbuf *mi; 212 struct udphdr *udp; 213 214 size = sizeof(struct udphdr); 215 if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE) { 216 /* 217 * draft-ietf-ipsec-nat-t-ike-0[01].txt and 218 * draft-ietf-ipsec-udp-encaps-(00/)01.txt, 219 * ignoring possible AH mode 220 * non-IKE marker + non-ESP marker 221 * from draft-ietf-ipsec-udp-encaps-00.txt. 222 */ 223 size += sizeof(u_int64_t); 224 } 225 mi = m_makespace(m, hlen, size, &off); 226 if (mi == NULL) { 227 DPRINTF(("%s: m_makespace for udphdr failed\n", 228 __func__)); 229 error = ENOBUFS; 230 goto bad; 231 } 232 233 udp = (struct udphdr *)(mtod(mi, caddr_t) + off); 234 if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE) 235 udp->uh_sport = htons(UDP_ENCAP_ESPINUDP_PORT); 236 else 237 udp->uh_sport = 238 KEY_PORTFROMSADDR(&sav->sah->saidx.src); 239 udp->uh_dport = KEY_PORTFROMSADDR(&sav->sah->saidx.dst); 240 udp->uh_sum = 0; 241 udp->uh_ulen = htons(m->m_pkthdr.len - hlen); 242 ip->ip_len = htons(m->m_pkthdr.len); 243 ip->ip_p = IPPROTO_UDP; 244 245 if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE) 246 *(u_int64_t *)(udp + 1) = 0; 247 } 248#endif /* IPSEC_NAT_T */ 249 250 return ip_output(m, NULL, NULL, IP_RAWOUTPUT, NULL, NULL); 251#endif /* INET */ 252#ifdef INET6 253 case AF_INET6: 254 /* 255 * We don't need massage, IPv6 header fields are always in 256 * net endian. 257 */ 258 return ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL); 259#endif /* INET6 */ 260 } 261 panic("ipsec_process_done"); 262bad: 263 m_freem(m); 264 return (error); 265} 266 267static struct ipsecrequest * 268ipsec_nextisr( 269 struct mbuf *m, 270 struct ipsecrequest *isr, 271 int af, 272 struct secasindex *saidx, 273 int *error 274) 275{ 276#define IPSEC_OSTAT(name) do { \ 277 if (isr->saidx.proto == IPPROTO_ESP) \ 278 ESPSTAT_INC(esps_##name); \ 279 else if (isr->saidx.proto == IPPROTO_AH)\ 280 AHSTAT_INC(ahs_##name); \ 281 else \ 282 IPCOMPSTAT_INC(ipcomps_##name); \ 283} while (0) 284 struct secasvar *sav; 285 286 IPSECREQUEST_LOCK_ASSERT(isr); 287 288 IPSEC_ASSERT(af == AF_INET || af == AF_INET6, 289 ("invalid address family %u", af)); 290again: 291 /* 292 * Craft SA index to search for proper SA. Note that 293 * we only fillin unspecified SA peers for transport 294 * mode; for tunnel mode they must already be filled in. 295 */ 296 *saidx = isr->saidx; 297 if (isr->saidx.mode == IPSEC_MODE_TRANSPORT) { 298 /* Fillin unspecified SA peers only for transport mode */ 299 if (af == AF_INET) { 300 struct sockaddr_in *sin; 301 struct ip *ip = mtod(m, struct ip *); 302 303 if (saidx->src.sa.sa_len == 0) { 304 sin = &saidx->src.sin; 305 sin->sin_len = sizeof(*sin); 306 sin->sin_family = AF_INET; 307 sin->sin_port = IPSEC_PORT_ANY; 308 sin->sin_addr = ip->ip_src; 309 } 310 if (saidx->dst.sa.sa_len == 0) { 311 sin = &saidx->dst.sin; 312 sin->sin_len = sizeof(*sin); 313 sin->sin_family = AF_INET; 314 sin->sin_port = IPSEC_PORT_ANY; 315 sin->sin_addr = ip->ip_dst; 316 } 317 } else { 318 struct sockaddr_in6 *sin6; 319 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 320 321 if (saidx->src.sin6.sin6_len == 0) { 322 sin6 = (struct sockaddr_in6 *)&saidx->src; 323 sin6->sin6_len = sizeof(*sin6); 324 sin6->sin6_family = AF_INET6; 325 sin6->sin6_port = IPSEC_PORT_ANY; 326 sin6->sin6_addr = ip6->ip6_src; 327 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) { 328 /* fix scope id for comparing SPD */ 329 sin6->sin6_addr.s6_addr16[1] = 0; 330 sin6->sin6_scope_id = 331 ntohs(ip6->ip6_src.s6_addr16[1]); 332 } 333 } 334 if (saidx->dst.sin6.sin6_len == 0) { 335 sin6 = (struct sockaddr_in6 *)&saidx->dst; 336 sin6->sin6_len = sizeof(*sin6); 337 sin6->sin6_family = AF_INET6; 338 sin6->sin6_port = IPSEC_PORT_ANY; 339 sin6->sin6_addr = ip6->ip6_dst; 340 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) { 341 /* fix scope id for comparing SPD */ 342 sin6->sin6_addr.s6_addr16[1] = 0; 343 sin6->sin6_scope_id = 344 ntohs(ip6->ip6_dst.s6_addr16[1]); 345 } 346 } 347 } 348 } 349 350 /* 351 * Lookup SA and validate it. 352 */ 353 *error = key_checkrequest(isr, saidx); 354 if (*error != 0) { 355 /* 356 * IPsec processing is required, but no SA found. 357 * I assume that key_acquire() had been called 358 * to get/establish the SA. Here I discard 359 * this packet because it is responsibility for 360 * upper layer to retransmit the packet. 361 */ 362 IPSECSTAT_INC(ips_out_nosa); 363 goto bad; 364 } 365 sav = isr->sav; 366 if (sav == NULL) { 367 IPSEC_ASSERT(ipsec_get_reqlevel(isr) == IPSEC_LEVEL_USE, 368 ("no SA found, but required; level %u", 369 ipsec_get_reqlevel(isr))); 370 IPSECREQUEST_UNLOCK(isr); 371 isr = isr->next; 372 /* 373 * If isr is NULL, we found a 'use' policy w/o SA. 374 * Return w/o error and w/o isr so we can drop out 375 * and continue w/o IPsec processing. 376 */ 377 if (isr == NULL) 378 return isr; 379 IPSECREQUEST_LOCK(isr); 380 goto again; 381 } 382 383 /* 384 * Check system global policy controls. 385 */ 386 if ((isr->saidx.proto == IPPROTO_ESP && !V_esp_enable) || 387 (isr->saidx.proto == IPPROTO_AH && !V_ah_enable) || 388 (isr->saidx.proto == IPPROTO_IPCOMP && !V_ipcomp_enable)) { 389 DPRINTF(("%s: IPsec outbound packet dropped due" 390 " to policy (check your sysctls)\n", __func__)); 391 IPSEC_OSTAT(pdrops); 392 *error = EHOSTUNREACH; 393 goto bad; 394 } 395 396 /* 397 * Sanity check the SA contents for the caller 398 * before they invoke the xform output method. 399 */ 400 if (sav->tdb_xform == NULL) { 401 DPRINTF(("%s: no transform for SA\n", __func__)); 402 IPSEC_OSTAT(noxform); 403 *error = EHOSTUNREACH; 404 goto bad; 405 } 406 return isr; 407bad: 408 IPSEC_ASSERT(*error != 0, ("error return w/ no error code")); 409 IPSECREQUEST_UNLOCK(isr); 410 return NULL; 411#undef IPSEC_OSTAT 412} 413 414#ifdef INET 415/* 416 * IPsec output logic for IPv4. 417 */ 418int 419ipsec4_process_packet( 420 struct mbuf *m, 421 struct ipsecrequest *isr, 422 int flags, 423 int tunalready) 424{ 425 struct secasindex saidx; 426 struct secasvar *sav; 427 struct ip *ip; 428 int error, i, off; 429 430 IPSEC_ASSERT(m != NULL, ("null mbuf")); 431 IPSEC_ASSERT(isr != NULL, ("null isr")); 432 433 IPSECREQUEST_LOCK(isr); /* insure SA contents don't change */ 434 435 isr = ipsec_nextisr(m, isr, AF_INET, &saidx, &error); 436 if (isr == NULL) { 437 if (error != 0) 438 goto bad; 439 return EJUSTRETURN; 440 } 441 442 sav = isr->sav; 443 444#ifdef DEV_ENC 445 encif->if_opackets++; 446 encif->if_obytes += m->m_pkthdr.len; 447 448 /* pass the mbuf to enc0 for bpf processing */ 449 ipsec_bpf(m, sav, AF_INET, ENC_OUT|ENC_BEFORE); 450 /* pass the mbuf to enc0 for packet filtering */ 451 if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_BEFORE)) != 0) 452 goto bad; 453#endif 454 455 if (!tunalready) { 456 union sockaddr_union *dst = &sav->sah->saidx.dst; 457 int setdf; 458 459 /* 460 * Collect IP_DF state from the outer header. 461 */ 462 if (dst->sa.sa_family == AF_INET) { 463 if (m->m_len < sizeof (struct ip) && 464 (m = m_pullup(m, sizeof (struct ip))) == NULL) { 465 error = ENOBUFS; 466 goto bad; 467 } 468 ip = mtod(m, struct ip *); 469 /* Honor system-wide control of how to handle IP_DF */ 470 switch (V_ip4_ipsec_dfbit) { 471 case 0: /* clear in outer header */ 472 case 1: /* set in outer header */ 473 setdf = V_ip4_ipsec_dfbit; 474 break; 475 default: /* propagate to outer header */ 476 setdf = ntohs(ip->ip_off & IP_DF); 477 break; 478 } 479 } else { 480 ip = NULL; /* keep compiler happy */ 481 setdf = 0; 482 } 483 /* Do the appropriate encapsulation, if necessary */ 484 if (isr->saidx.mode == IPSEC_MODE_TUNNEL || /* Tunnel requ'd */ 485 dst->sa.sa_family != AF_INET || /* PF mismatch */ 486#if 0 487 (sav->flags & SADB_X_SAFLAGS_TUNNEL) || /* Tunnel requ'd */ 488 sav->tdb_xform->xf_type == XF_IP4 || /* ditto */ 489#endif 490 (dst->sa.sa_family == AF_INET && /* Proxy */ 491 dst->sin.sin_addr.s_addr != INADDR_ANY && 492 dst->sin.sin_addr.s_addr != ip->ip_dst.s_addr)) { 493 struct mbuf *mp; 494 495 /* Fix IPv4 header checksum and length */ 496 if (m->m_len < sizeof (struct ip) && 497 (m = m_pullup(m, sizeof (struct ip))) == NULL) { 498 error = ENOBUFS; 499 goto bad; 500 } 501 ip = mtod(m, struct ip *); 502 ip->ip_len = htons(m->m_pkthdr.len); 503 ip->ip_sum = 0; 504 ip->ip_sum = in_cksum(m, ip->ip_hl << 2); 505 506 /* Encapsulate the packet */ 507 error = ipip_output(m, isr, &mp, 0, 0); 508 if (mp == NULL && !error) { 509 /* Should never happen. */ 510 DPRINTF(("%s: ipip_output returns no mbuf and " 511 "no error!", __func__)); 512 error = EFAULT; 513 } 514 if (error) { 515 if (mp) { 516 /* XXX: Should never happen! */ 517 m_freem(mp); 518 } 519 m = NULL; /* ipip_output() already freed it */ 520 goto bad; 521 } 522 m = mp, mp = NULL; 523 /* 524 * ipip_output clears IP_DF in the new header. If 525 * we need to propagate IP_DF from the outer header, 526 * then we have to do it here. 527 * 528 * XXX shouldn't assume what ipip_output does. 529 */ 530 if (dst->sa.sa_family == AF_INET && setdf) { 531 if (m->m_len < sizeof (struct ip) && 532 (m = m_pullup(m, sizeof (struct ip))) == NULL) { 533 error = ENOBUFS; 534 goto bad; 535 } 536 ip = mtod(m, struct ip *); 537 ip->ip_off = ntohs(ip->ip_off); 538 ip->ip_off |= IP_DF; 539 ip->ip_off = htons(ip->ip_off); 540 } 541 } 542 } 543 544#ifdef DEV_ENC 545 /* pass the mbuf to enc0 for bpf processing */ 546 ipsec_bpf(m, sav, AF_INET, ENC_OUT|ENC_AFTER); 547 /* pass the mbuf to enc0 for packet filtering */ 548 if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_AFTER)) != 0) 549 goto bad; 550#endif 551 552 /* 553 * Dispatch to the appropriate IPsec transform logic. The 554 * packet will be returned for transmission after crypto 555 * processing, etc. are completed. For encapsulation we 556 * bypass this call because of the explicit call done above 557 * (necessary to deal with IP_DF handling for IPv4). 558 * 559 * NB: m & sav are ``passed to caller'' who's reponsible for 560 * for reclaiming their resources. 561 */ 562 if (sav->tdb_xform->xf_type != XF_IP4) { 563 ip = mtod(m, struct ip *); 564 i = ip->ip_hl << 2; 565 off = offsetof(struct ip, ip_p); 566 error = (*sav->tdb_xform->xf_output)(m, isr, NULL, i, off); 567 } else { 568 error = ipsec_process_done(m, isr); 569 } 570 IPSECREQUEST_UNLOCK(isr); 571 return error; 572bad: 573 if (isr) 574 IPSECREQUEST_UNLOCK(isr); 575 if (m) 576 m_freem(m); 577 return error; 578} 579#endif 580 581#ifdef INET6 582/* 583 * Chop IP6 header from the payload. 584 */ 585static struct mbuf * 586ipsec6_splithdr(struct mbuf *m) 587{ 588 struct mbuf *mh; 589 struct ip6_hdr *ip6; 590 int hlen; 591 592 IPSEC_ASSERT(m->m_len >= sizeof (struct ip6_hdr), 593 ("first mbuf too short, len %u", m->m_len)); 594 ip6 = mtod(m, struct ip6_hdr *); 595 hlen = sizeof(struct ip6_hdr); 596 if (m->m_len > hlen) { 597 MGETHDR(mh, M_NOWAIT, MT_DATA); 598 if (!mh) { 599 m_freem(m); 600 return NULL; 601 } 602 M_MOVE_PKTHDR(mh, m); 603 MH_ALIGN(mh, hlen); 604 m->m_len -= hlen; 605 m->m_data += hlen; 606 mh->m_next = m; 607 m = mh; 608 m->m_len = hlen; 609 bcopy((caddr_t)ip6, mtod(m, caddr_t), hlen); 610 } else if (m->m_len < hlen) { 611 m = m_pullup(m, hlen); 612 if (!m) 613 return NULL; 614 } 615 return m; 616} 617 618/* 619 * IPsec output logic for IPv6, transport mode. 620 */ 621int 622ipsec6_output_trans( 623 struct ipsec_output_state *state, 624 u_char *nexthdrp, 625 struct mbuf *mprev, 626 struct secpolicy *sp, 627 int flags, 628 int *tun) 629{ 630 struct ipsecrequest *isr; 631 struct secasindex saidx; 632 int error = 0; 633 struct mbuf *m; 634 635 IPSEC_ASSERT(state != NULL, ("null state")); 636 IPSEC_ASSERT(state->m != NULL, ("null m")); 637 IPSEC_ASSERT(nexthdrp != NULL, ("null nexthdrp")); 638 IPSEC_ASSERT(mprev != NULL, ("null mprev")); 639 IPSEC_ASSERT(sp != NULL, ("null sp")); 640 IPSEC_ASSERT(tun != NULL, ("null tun")); 641 642 KEYDEBUG(KEYDEBUG_IPSEC_DATA, 643 printf("%s: applied SP\n", __func__); 644 kdebug_secpolicy(sp)); 645 646 isr = sp->req; 647 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) { 648 /* the rest will be handled by ipsec6_output_tunnel() */ 649 *tun = 1; /* need tunnel-mode processing */ 650 return 0; 651 } 652 653 *tun = 0; 654 m = state->m; 655 656 IPSECREQUEST_LOCK(isr); /* insure SA contents don't change */ 657 isr = ipsec_nextisr(m, isr, AF_INET6, &saidx, &error); 658 if (isr == NULL) { 659 if (error != 0) { 660#ifdef notdef 661 /* XXX should notification be done for all errors ? */ 662 /* 663 * Notify the fact that the packet is discarded 664 * to ourselves. I believe this is better than 665 * just silently discarding. (jinmei@kame.net) 666 * XXX: should we restrict the error to TCP packets? 667 * XXX: should we directly notify sockets via 668 * pfctlinputs? 669 */ 670 icmp6_error(m, ICMP6_DST_UNREACH, 671 ICMP6_DST_UNREACH_ADMIN, 0); 672 m = NULL; /* NB: icmp6_error frees mbuf */ 673#endif 674 goto bad; 675 } 676 return EJUSTRETURN; 677 } 678 679 error = (*isr->sav->tdb_xform->xf_output)(m, isr, NULL, 680 sizeof (struct ip6_hdr), 681 offsetof(struct ip6_hdr, 682 ip6_nxt)); 683 IPSECREQUEST_UNLOCK(isr); 684 return error; 685bad: 686 if (isr) 687 IPSECREQUEST_UNLOCK(isr); 688 if (m) 689 m_freem(m); 690 state->m = NULL; 691 return error; 692} 693 694static int 695ipsec6_encapsulate(struct mbuf *m, struct secasvar *sav) 696{ 697 struct ip6_hdr *oip6; 698 struct ip6_hdr *ip6; 699 size_t plen; 700 701 /* can't tunnel between different AFs */ 702 if (sav->sah->saidx.src.sa.sa_family != AF_INET6 || 703 sav->sah->saidx.dst.sa.sa_family != AF_INET6) { 704 m_freem(m); 705 return EINVAL; 706 } 707 IPSEC_ASSERT(m->m_len == sizeof (struct ip6_hdr), 708 ("mbuf wrong size; len %u", m->m_len)); 709 710 711 /* 712 * grow the mbuf to accomodate the new IPv6 header. 713 */ 714 plen = m->m_pkthdr.len; 715 if (M_LEADINGSPACE(m->m_next) < sizeof(struct ip6_hdr)) { 716 struct mbuf *n; 717 MGET(n, M_NOWAIT, MT_DATA); 718 if (!n) { 719 m_freem(m); 720 return ENOBUFS; 721 } 722 n->m_len = sizeof(struct ip6_hdr); 723 n->m_next = m->m_next; 724 m->m_next = n; 725 m->m_pkthdr.len += sizeof(struct ip6_hdr); 726 oip6 = mtod(n, struct ip6_hdr *); 727 } else { 728 m->m_next->m_len += sizeof(struct ip6_hdr); 729 m->m_next->m_data -= sizeof(struct ip6_hdr); 730 m->m_pkthdr.len += sizeof(struct ip6_hdr); 731 oip6 = mtod(m->m_next, struct ip6_hdr *); 732 } 733 ip6 = mtod(m, struct ip6_hdr *); 734 bcopy((caddr_t)ip6, (caddr_t)oip6, sizeof(struct ip6_hdr)); 735 736 /* Fake link-local scope-class addresses */ 737 if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_src)) 738 oip6->ip6_src.s6_addr16[1] = 0; 739 if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_dst)) 740 oip6->ip6_dst.s6_addr16[1] = 0; 741 742 /* construct new IPv6 header. see RFC 2401 5.1.2.2 */ 743 /* ECN consideration. */ 744 ip6_ecn_ingress(V_ip6_ipsec_ecn, &ip6->ip6_flow, &oip6->ip6_flow); 745 if (plen < IPV6_MAXPACKET - sizeof(struct ip6_hdr)) 746 ip6->ip6_plen = htons(plen); 747 else { 748 /* ip6->ip6_plen will be updated in ip6_output() */ 749 } 750 ip6->ip6_nxt = IPPROTO_IPV6; 751 ip6->ip6_src = sav->sah->saidx.src.sin6.sin6_addr; 752 ip6->ip6_dst = sav->sah->saidx.dst.sin6.sin6_addr; 753 ip6->ip6_hlim = IPV6_DEFHLIM; 754 755 /* XXX Should ip6_src be updated later ? */ 756 757 return 0; 758} 759 760/* 761 * IPsec output logic for IPv6, tunnel mode. 762 */ 763int 764ipsec6_output_tunnel(struct ipsec_output_state *state, struct secpolicy *sp, int flags) 765{ 766 struct ip6_hdr *ip6; 767 struct ipsecrequest *isr; 768 struct secasindex saidx; 769 int error; 770 struct sockaddr_in6 *dst6; 771 struct mbuf *m; 772 773 IPSEC_ASSERT(state != NULL, ("null state")); 774 IPSEC_ASSERT(state->m != NULL, ("null m")); 775 IPSEC_ASSERT(sp != NULL, ("null sp")); 776 777 KEYDEBUG(KEYDEBUG_IPSEC_DATA, 778 printf("%s: applied SP\n", __func__); 779 kdebug_secpolicy(sp)); 780 781 m = state->m; 782 /* 783 * transport mode ipsec (before the 1st tunnel mode) is already 784 * processed by ipsec6_output_trans(). 785 */ 786 for (isr = sp->req; isr; isr = isr->next) { 787 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) 788 break; 789 } 790 791 IPSECREQUEST_LOCK(isr); /* insure SA contents don't change */ 792 isr = ipsec_nextisr(m, isr, AF_INET6, &saidx, &error); 793 if (isr == NULL) { 794 if (error != 0) 795 goto bad; 796 return EJUSTRETURN; 797 } 798 799#ifdef DEV_ENC 800 encif->if_opackets++; 801 encif->if_obytes += m->m_pkthdr.len; 802 803 /* pass the mbuf to enc0 for bpf processing */ 804 ipsec_bpf(m, isr->sav, AF_INET6, ENC_OUT|ENC_BEFORE); 805 /* pass the mbuf to enc0 for packet filtering */ 806 if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_BEFORE)) != 0) 807 goto bad; 808#endif 809 810 /* 811 * There may be the case that SA status will be changed when 812 * we are refering to one. So calling splsoftnet(). 813 */ 814 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) { 815 /* 816 * build IPsec tunnel. 817 */ 818 /* XXX should be processed with other familiy */ 819 if (isr->sav->sah->saidx.src.sa.sa_family != AF_INET6) { 820 ipseclog((LOG_ERR, "%s: family mismatched between " 821 "inner and outer, spi=%u\n", __func__, 822 ntohl(isr->sav->spi))); 823 IPSEC6STAT_INC(ips_out_inval); 824 error = EAFNOSUPPORT; 825 goto bad; 826 } 827 828 m = ipsec6_splithdr(m); 829 if (!m) { 830 IPSEC6STAT_INC(ips_out_nomem); 831 error = ENOMEM; 832 goto bad; 833 } 834 error = ipsec6_encapsulate(m, isr->sav); 835 if (error) { 836 m = NULL; 837 goto bad; 838 } 839 ip6 = mtod(m, struct ip6_hdr *); 840 841 state->ro = 842 (struct route *)&isr->sav->sah->route_cache.sin6_route; 843 state->dst = (struct sockaddr *)&state->ro->ro_dst; 844 dst6 = (struct sockaddr_in6 *)state->dst; 845 if (state->ro->ro_rt 846 && ((state->ro->ro_rt->rt_flags & RTF_UP) == 0 847 || !IN6_ARE_ADDR_EQUAL(&dst6->sin6_addr, &ip6->ip6_dst))) { 848 RTFREE(state->ro->ro_rt); 849 state->ro->ro_rt = NULL; 850 } 851 if (state->ro->ro_rt == NULL) { 852 bzero(dst6, sizeof(*dst6)); 853 dst6->sin6_family = AF_INET6; 854 dst6->sin6_len = sizeof(*dst6); 855 dst6->sin6_addr = ip6->ip6_dst; 856 rtalloc_ign_fib(state->ro, 0UL, M_GETFIB(m)); 857 } 858 if (state->ro->ro_rt == NULL) { 859 IP6STAT_INC(ip6s_noroute); 860 IPSEC6STAT_INC(ips_out_noroute); 861 error = EHOSTUNREACH; 862 goto bad; 863 } 864 865 /* adjust state->dst if tunnel endpoint is offlink */ 866 if (state->ro->ro_rt->rt_flags & RTF_GATEWAY) 867 state->dst = (struct sockaddr *)state->ro->ro_rt->rt_gateway; 868 } 869 870 m = ipsec6_splithdr(m); 871 if (!m) { 872 IPSEC6STAT_INC(ips_out_nomem); 873 error = ENOMEM; 874 goto bad; 875 } 876 ip6 = mtod(m, struct ip6_hdr *); 877 878#ifdef DEV_ENC 879 /* pass the mbuf to enc0 for bpf processing */ 880 ipsec_bpf(m, isr->sav, AF_INET6, ENC_OUT|ENC_AFTER); 881 /* pass the mbuf to enc0 for packet filtering */ 882 if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_AFTER)) != 0) 883 goto bad; 884#endif 885 886 error = (*isr->sav->tdb_xform->xf_output)(m, isr, NULL, 887 sizeof (struct ip6_hdr), 888 offsetof(struct ip6_hdr, ip6_nxt)); 889 IPSECREQUEST_UNLOCK(isr); 890 return error; 891bad: 892 if (isr) 893 IPSECREQUEST_UNLOCK(isr); 894 if (m) 895 m_freem(m); 896 state->m = NULL; 897 return error; 898} 899#endif /*INET6*/ 900