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 * $FreeBSD$ 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/pfil.h> 48 #include <net/route.h> 49 #include <net/vnet.h> 50 51 #include <netinet/in.h> 52 #include <netinet/in_systm.h> 53 #include <netinet/ip.h> 54 #include <netinet/ip_var.h> 55 #include <netinet/in_var.h> 56 #include <netinet/ip_ecn.h> 57 #ifdef INET6 58 #include <netinet6/ip6_ecn.h> 59 #endif 60 61 #include <netinet/ip6.h> 62 #ifdef INET6 63 #include <netinet6/ip6_var.h> 64 #endif 65 #include <netinet/in_pcb.h> 66 #ifdef INET6 67 #include <netinet/icmp6.h> 68 #endif 69 70 #include <netipsec/ipsec.h> 71 #ifdef INET6 72 #include <netipsec/ipsec6.h> 73 #endif 74 #include <netipsec/ah_var.h> 75 #include <netipsec/esp_var.h> 76 #include <netipsec/ipcomp_var.h> 77 78 #include <netipsec/xform.h> 79 80 #include <netipsec/key.h> 81 #include <netipsec/keydb.h> 82 #include <netipsec/key_debug.h> 83 84 #include <machine/in_cksum.h> 85 86 #ifdef IPSEC_NAT_T 87 #include <netinet/udp.h> 88 #endif 89 90 #ifdef DEV_ENC 91 #include <net/if_enc.h> 92 #endif 93 94 95 int 96 ipsec_process_done(struct mbuf *m, struct ipsecrequest *isr) 97 { 98 struct tdb_ident *tdbi; 99 struct m_tag *mtag; 100 struct secasvar *sav; 101 struct secasindex *saidx; 102 int error; 103 104 IPSEC_ASSERT(m != NULL, ("null mbuf")); 105 IPSEC_ASSERT(isr != NULL, ("null ISR")); 106 sav = isr->sav; 107 IPSEC_ASSERT(sav != NULL, ("null SA")); 108 IPSEC_ASSERT(sav->sah != NULL, ("null SAH")); 109 110 saidx = &sav->sah->saidx; 111 switch (saidx->dst.sa.sa_family) { 112 #ifdef INET 113 case AF_INET: 114 /* Fix the header length, for AH processing. */ 115 mtod(m, struct ip *)->ip_len = htons(m->m_pkthdr.len); 116 break; 117 #endif /* INET */ 118 #ifdef INET6 119 case AF_INET6: 120 /* Fix the header length, for AH processing. */ 121 if (m->m_pkthdr.len < sizeof (struct ip6_hdr)) { 122 error = ENXIO; 123 goto bad; 124 } 125 if (m->m_pkthdr.len - sizeof (struct ip6_hdr) > IPV6_MAXPACKET) { 126 /* No jumbogram support. */ 127 error = ENXIO; /*?*/ 128 goto bad; 129 } 130 mtod(m, struct ip6_hdr *)->ip6_plen = 131 htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 132 break; 133 #endif /* INET6 */ 134 default: 135 DPRINTF(("%s: unknown protocol family %u\n", __func__, 136 saidx->dst.sa.sa_family)); 137 error = ENXIO; 138 goto bad; 139 } 140 141 /* 142 * Add a record of what we've done or what needs to be done to the 143 * packet. 144 */ 145 mtag = m_tag_get(PACKET_TAG_IPSEC_OUT_DONE, 146 sizeof(struct tdb_ident), M_NOWAIT); 147 if (mtag == NULL) { 148 DPRINTF(("%s: could not get packet tag\n", __func__)); 149 error = ENOMEM; 150 goto bad; 151 } 152 153 tdbi = (struct tdb_ident *)(mtag + 1); 154 tdbi->dst = saidx->dst; 155 tdbi->proto = saidx->proto; 156 tdbi->spi = sav->spi; 157 m_tag_prepend(m, mtag); 158 159 /* 160 * If there's another (bundled) SA to apply, do so. 161 * Note that this puts a burden on the kernel stack size. 162 * If this is a problem we'll need to introduce a queue 163 * to set the packet on so we can unwind the stack before 164 * doing further processing. 165 */ 166 if (isr->next) { 167 V_ipsec4stat.ips_out_bundlesa++; 168 return ipsec4_process_packet(m, isr->next, 0, 0); 169 } 170 key_sa_recordxfer(sav, m); /* record data transfer */ 171 172 /* 173 * We're done with IPsec processing, transmit the packet using the 174 * appropriate network protocol (IP or IPv6). SPD lookup will be 175 * performed again there. 176 */ 177 switch (saidx->dst.sa.sa_family) { 178 #ifdef INET 179 struct ip *ip; 180 case AF_INET: 181 ip = mtod(m, struct ip *); 182 ip->ip_len = ntohs(ip->ip_len); 183 ip->ip_off = ntohs(ip->ip_off); 184 185 #ifdef IPSEC_NAT_T 186 /* 187 * If NAT-T is enabled, now that all IPsec processing is done 188 * insert UDP encapsulation header after IP header. 189 */ 190 if (sav->natt_type) { 191 #ifdef _IP_VHL 192 const int hlen = IP_VHL_HL(ip->ip_vhl); 193 #else 194 const int hlen = (ip->ip_hl << 2); 195 #endif 196 int size, off; 197 struct mbuf *mi; 198 struct udphdr *udp; 199 200 size = sizeof(struct udphdr); 201 if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE) { 202 /* 203 * draft-ietf-ipsec-nat-t-ike-0[01].txt and 204 * draft-ietf-ipsec-udp-encaps-(00/)01.txt, 205 * ignoring possible AH mode 206 * non-IKE marker + non-ESP marker 207 * from draft-ietf-ipsec-udp-encaps-00.txt. 208 */ 209 size += sizeof(u_int64_t); 210 } 211 mi = m_makespace(m, hlen, size, &off); 212 if (mi == NULL) { 213 DPRINTF(("%s: m_makespace for udphdr failed\n", 214 __func__)); 215 error = ENOBUFS; 216 goto bad; 217 } 218 219 udp = (struct udphdr *)(mtod(mi, caddr_t) + off); 220 if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE) 221 udp->uh_sport = htons(UDP_ENCAP_ESPINUDP_PORT); 222 else 223 udp->uh_sport = 224 KEY_PORTFROMSADDR(&sav->sah->saidx.src); 225 udp->uh_dport = KEY_PORTFROMSADDR(&sav->sah->saidx.dst); 226 udp->uh_sum = 0; 227 udp->uh_ulen = htons(m->m_pkthdr.len - hlen); 228 ip->ip_len = m->m_pkthdr.len; 229 ip->ip_p = IPPROTO_UDP; 230 231 if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE) 232 *(u_int64_t *)(udp + 1) = 0; 233 } 234 #endif /* IPSEC_NAT_T */ 235 236 return ip_output(m, NULL, NULL, IP_RAWOUTPUT, NULL, NULL); 237 #endif /* INET */ 238 #ifdef INET6 239 case AF_INET6: 240 /* 241 * We don't need massage, IPv6 header fields are always in 242 * net endian. 243 */ 244 return ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL); 245 #endif /* INET6 */ 246 } 247 panic("ipsec_process_done"); 248 bad: 249 m_freem(m); 250 return (error); 251 } 252 253 static struct ipsecrequest * 254 ipsec_nextisr( 255 struct mbuf *m, 256 struct ipsecrequest *isr, 257 int af, 258 struct secasindex *saidx, 259 int *error 260 ) 261 { 262 #define IPSEC_OSTAT(x,y,z) (isr->saidx.proto == IPPROTO_ESP ? (x)++ : \ 263 isr->saidx.proto == IPPROTO_AH ? (y)++ : (z)++) 264 struct secasvar *sav; 265 266 IPSECREQUEST_LOCK_ASSERT(isr); 267 268 IPSEC_ASSERT(af == AF_INET || af == AF_INET6, 269 ("invalid address family %u", af)); 270 again: 271 /* 272 * Craft SA index to search for proper SA. Note that 273 * we only fillin unspecified SA peers for transport 274 * mode; for tunnel mode they must already be filled in. 275 */ 276 *saidx = isr->saidx; 277 if (isr->saidx.mode == IPSEC_MODE_TRANSPORT) { 278 /* Fillin unspecified SA peers only for transport mode */ 279 if (af == AF_INET) { 280 struct sockaddr_in *sin; 281 struct ip *ip = mtod(m, struct ip *); 282 283 if (saidx->src.sa.sa_len == 0) { 284 sin = &saidx->src.sin; 285 sin->sin_len = sizeof(*sin); 286 sin->sin_family = AF_INET; 287 sin->sin_port = IPSEC_PORT_ANY; 288 sin->sin_addr = ip->ip_src; 289 } 290 if (saidx->dst.sa.sa_len == 0) { 291 sin = &saidx->dst.sin; 292 sin->sin_len = sizeof(*sin); 293 sin->sin_family = AF_INET; 294 sin->sin_port = IPSEC_PORT_ANY; 295 sin->sin_addr = ip->ip_dst; 296 } 297 } else { 298 struct sockaddr_in6 *sin6; 299 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 300 301 if (saidx->src.sin6.sin6_len == 0) { 302 sin6 = (struct sockaddr_in6 *)&saidx->src; 303 sin6->sin6_len = sizeof(*sin6); 304 sin6->sin6_family = AF_INET6; 305 sin6->sin6_port = IPSEC_PORT_ANY; 306 sin6->sin6_addr = ip6->ip6_src; 307 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) { 308 /* fix scope id for comparing SPD */ 309 sin6->sin6_addr.s6_addr16[1] = 0; 310 sin6->sin6_scope_id = 311 ntohs(ip6->ip6_src.s6_addr16[1]); 312 } 313 } 314 if (saidx->dst.sin6.sin6_len == 0) { 315 sin6 = (struct sockaddr_in6 *)&saidx->dst; 316 sin6->sin6_len = sizeof(*sin6); 317 sin6->sin6_family = AF_INET6; 318 sin6->sin6_port = IPSEC_PORT_ANY; 319 sin6->sin6_addr = ip6->ip6_dst; 320 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) { 321 /* fix scope id for comparing SPD */ 322 sin6->sin6_addr.s6_addr16[1] = 0; 323 sin6->sin6_scope_id = 324 ntohs(ip6->ip6_dst.s6_addr16[1]); 325 } 326 } 327 } 328 } 329 330 /* 331 * Lookup SA and validate it. 332 */ 333 *error = key_checkrequest(isr, saidx); 334 if (*error != 0) { 335 /* 336 * IPsec processing is required, but no SA found. 337 * I assume that key_acquire() had been called 338 * to get/establish the SA. Here I discard 339 * this packet because it is responsibility for 340 * upper layer to retransmit the packet. 341 */ 342 V_ipsec4stat.ips_out_nosa++; 343 goto bad; 344 } 345 sav = isr->sav; 346 if (sav == NULL) { 347 IPSEC_ASSERT(ipsec_get_reqlevel(isr) == IPSEC_LEVEL_USE, 348 ("no SA found, but required; level %u", 349 ipsec_get_reqlevel(isr))); 350 IPSECREQUEST_UNLOCK(isr); 351 isr = isr->next; 352 /* 353 * If isr is NULL, we found a 'use' policy w/o SA. 354 * Return w/o error and w/o isr so we can drop out 355 * and continue w/o IPsec processing. 356 */ 357 if (isr == NULL) 358 return isr; 359 IPSECREQUEST_LOCK(isr); 360 goto again; 361 } 362 363 /* 364 * Check system global policy controls. 365 */ 366 if ((isr->saidx.proto == IPPROTO_ESP && !V_esp_enable) || 367 (isr->saidx.proto == IPPROTO_AH && !V_ah_enable) || 368 (isr->saidx.proto == IPPROTO_IPCOMP && !V_ipcomp_enable)) { 369 DPRINTF(("%s: IPsec outbound packet dropped due" 370 " to policy (check your sysctls)\n", __func__)); 371 IPSEC_OSTAT(V_espstat.esps_pdrops, V_ahstat.ahs_pdrops, 372 V_ipcompstat.ipcomps_pdrops); 373 *error = EHOSTUNREACH; 374 goto bad; 375 } 376 377 /* 378 * Sanity check the SA contents for the caller 379 * before they invoke the xform output method. 380 */ 381 if (sav->tdb_xform == NULL) { 382 DPRINTF(("%s: no transform for SA\n", __func__)); 383 IPSEC_OSTAT(V_espstat.esps_noxform, V_ahstat.ahs_noxform, 384 V_ipcompstat.ipcomps_noxform); 385 *error = EHOSTUNREACH; 386 goto bad; 387 } 388 return isr; 389 bad: 390 IPSEC_ASSERT(*error != 0, ("error return w/ no error code")); 391 IPSECREQUEST_UNLOCK(isr); 392 return NULL; 393 #undef IPSEC_OSTAT 394 } 395 396 #ifdef INET 397 /* 398 * IPsec output logic for IPv4. 399 */ 400 int 401 ipsec4_process_packet( 402 struct mbuf *m, 403 struct ipsecrequest *isr, 404 int flags, 405 int tunalready) 406 { 407 struct secasindex saidx; 408 struct secasvar *sav; 409 struct ip *ip; 410 int error, i, off; 411 412 IPSEC_ASSERT(m != NULL, ("null mbuf")); 413 IPSEC_ASSERT(isr != NULL, ("null isr")); 414 415 IPSECREQUEST_LOCK(isr); /* insure SA contents don't change */ 416 417 isr = ipsec_nextisr(m, isr, AF_INET, &saidx, &error); 418 if (isr == NULL) { 419 if (error != 0) 420 goto bad; 421 return EJUSTRETURN; 422 } 423 424 sav = isr->sav; 425 426 #ifdef DEV_ENC 427 encif->if_opackets++; 428 encif->if_obytes += m->m_pkthdr.len; 429 430 /* pass the mbuf to enc0 for bpf processing */ 431 ipsec_bpf(m, sav, AF_INET, ENC_OUT|ENC_BEFORE); 432 /* pass the mbuf to enc0 for packet filtering */ 433 if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_BEFORE)) != 0) 434 goto bad; 435 #endif 436 437 if (!tunalready) { 438 union sockaddr_union *dst = &sav->sah->saidx.dst; 439 int setdf; 440 441 /* 442 * Collect IP_DF state from the outer header. 443 */ 444 if (dst->sa.sa_family == AF_INET) { 445 if (m->m_len < sizeof (struct ip) && 446 (m = m_pullup(m, sizeof (struct ip))) == NULL) { 447 error = ENOBUFS; 448 goto bad; 449 } 450 ip = mtod(m, struct ip *); 451 /* Honor system-wide control of how to handle IP_DF */ 452 switch (V_ip4_ipsec_dfbit) { 453 case 0: /* clear in outer header */ 454 case 1: /* set in outer header */ 455 setdf = V_ip4_ipsec_dfbit; 456 break; 457 default: /* propagate to outer header */ 458 setdf = ntohs(ip->ip_off & IP_DF); 459 break; 460 } 461 } else { 462 ip = NULL; /* keep compiler happy */ 463 setdf = 0; 464 } 465 /* Do the appropriate encapsulation, if necessary */ 466 if (isr->saidx.mode == IPSEC_MODE_TUNNEL || /* Tunnel requ'd */ 467 dst->sa.sa_family != AF_INET || /* PF mismatch */ 468 #if 0 469 (sav->flags & SADB_X_SAFLAGS_TUNNEL) || /* Tunnel requ'd */ 470 sav->tdb_xform->xf_type == XF_IP4 || /* ditto */ 471 #endif 472 (dst->sa.sa_family == AF_INET && /* Proxy */ 473 dst->sin.sin_addr.s_addr != INADDR_ANY && 474 dst->sin.sin_addr.s_addr != ip->ip_dst.s_addr)) { 475 struct mbuf *mp; 476 477 /* Fix IPv4 header checksum and length */ 478 if (m->m_len < sizeof (struct ip) && 479 (m = m_pullup(m, sizeof (struct ip))) == NULL) { 480 error = ENOBUFS; 481 goto bad; 482 } 483 ip = mtod(m, struct ip *); 484 ip->ip_len = htons(m->m_pkthdr.len); 485 ip->ip_sum = 0; 486 #ifdef _IP_VHL 487 if (ip->ip_vhl == IP_VHL_BORING) 488 ip->ip_sum = in_cksum_hdr(ip); 489 else 490 ip->ip_sum = in_cksum(m, 491 _IP_VHL_HL(ip->ip_vhl) << 2); 492 #else 493 ip->ip_sum = in_cksum(m, ip->ip_hl << 2); 494 #endif 495 496 /* Encapsulate the packet */ 497 error = ipip_output(m, isr, &mp, 0, 0); 498 if (mp == NULL && !error) { 499 /* Should never happen. */ 500 DPRINTF(("%s: ipip_output returns no mbuf and " 501 "no error!", __func__)); 502 error = EFAULT; 503 } 504 if (error) { 505 if (mp) { 506 /* XXX: Should never happen! */ 507 m_freem(mp); 508 } 509 m = NULL; /* ipip_output() already freed it */ 510 goto bad; 511 } 512 m = mp, mp = NULL; 513 /* 514 * ipip_output clears IP_DF in the new header. If 515 * we need to propagate IP_DF from the outer header, 516 * then we have to do it here. 517 * 518 * XXX shouldn't assume what ipip_output does. 519 */ 520 if (dst->sa.sa_family == AF_INET && setdf) { 521 if (m->m_len < sizeof (struct ip) && 522 (m = m_pullup(m, sizeof (struct ip))) == NULL) { 523 error = ENOBUFS; 524 goto bad; 525 } 526 ip = mtod(m, struct ip *); 527 ip->ip_off = ntohs(ip->ip_off); 528 ip->ip_off |= IP_DF; 529 ip->ip_off = htons(ip->ip_off); 530 } 531 } 532 } 533 534 #ifdef DEV_ENC 535 /* pass the mbuf to enc0 for bpf processing */ 536 ipsec_bpf(m, sav, AF_INET, ENC_OUT|ENC_AFTER); 537 /* pass the mbuf to enc0 for packet filtering */ 538 if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_AFTER)) != 0) 539 goto bad; 540 #endif 541 542 /* 543 * Dispatch to the appropriate IPsec transform logic. The 544 * packet will be returned for transmission after crypto 545 * processing, etc. are completed. For encapsulation we 546 * bypass this call because of the explicit call done above 547 * (necessary to deal with IP_DF handling for IPv4). 548 * 549 * NB: m & sav are ``passed to caller'' who's reponsible for 550 * for reclaiming their resources. 551 */ 552 if (sav->tdb_xform->xf_type != XF_IP4) { 553 ip = mtod(m, struct ip *); 554 i = ip->ip_hl << 2; 555 off = offsetof(struct ip, ip_p); 556 error = (*sav->tdb_xform->xf_output)(m, isr, NULL, i, off); 557 } else { 558 error = ipsec_process_done(m, isr); 559 } 560 IPSECREQUEST_UNLOCK(isr); 561 return error; 562 bad: 563 if (isr) 564 IPSECREQUEST_UNLOCK(isr); 565 if (m) 566 m_freem(m); 567 return error; 568 } 569 #endif 570 571 #ifdef INET6 572 /* 573 * Chop IP6 header from the payload. 574 */ 575 static struct mbuf * 576 ipsec6_splithdr(struct mbuf *m) 577 { 578 struct mbuf *mh; 579 struct ip6_hdr *ip6; 580 int hlen; 581 582 IPSEC_ASSERT(m->m_len >= sizeof (struct ip6_hdr), 583 ("first mbuf too short, len %u", m->m_len)); 584 ip6 = mtod(m, struct ip6_hdr *); 585 hlen = sizeof(struct ip6_hdr); 586 if (m->m_len > hlen) { 587 MGETHDR(mh, M_DONTWAIT, MT_DATA); 588 if (!mh) { 589 m_freem(m); 590 return NULL; 591 } 592 M_MOVE_PKTHDR(mh, m); 593 MH_ALIGN(mh, hlen); 594 m->m_len -= hlen; 595 m->m_data += hlen; 596 mh->m_next = m; 597 m = mh; 598 m->m_len = hlen; 599 bcopy((caddr_t)ip6, mtod(m, caddr_t), hlen); 600 } else if (m->m_len < hlen) { 601 m = m_pullup(m, hlen); 602 if (!m) 603 return NULL; 604 } 605 return m; 606 } 607 608 /* 609 * IPsec output logic for IPv6, transport mode. 610 */ 611 int 612 ipsec6_output_trans( 613 struct ipsec_output_state *state, 614 u_char *nexthdrp, 615 struct mbuf *mprev, 616 struct secpolicy *sp, 617 int flags, 618 int *tun) 619 { 620 struct ipsecrequest *isr; 621 struct secasindex saidx; 622 int error = 0; 623 struct mbuf *m; 624 625 IPSEC_ASSERT(state != NULL, ("null state")); 626 IPSEC_ASSERT(state->m != NULL, ("null m")); 627 IPSEC_ASSERT(nexthdrp != NULL, ("null nexthdrp")); 628 IPSEC_ASSERT(mprev != NULL, ("null mprev")); 629 IPSEC_ASSERT(sp != NULL, ("null sp")); 630 IPSEC_ASSERT(tun != NULL, ("null tun")); 631 632 KEYDEBUG(KEYDEBUG_IPSEC_DATA, 633 printf("%s: applied SP\n", __func__); 634 kdebug_secpolicy(sp)); 635 636 isr = sp->req; 637 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) { 638 /* the rest will be handled by ipsec6_output_tunnel() */ 639 *tun = 1; /* need tunnel-mode processing */ 640 return 0; 641 } 642 643 *tun = 0; 644 m = state->m; 645 646 IPSECREQUEST_LOCK(isr); /* insure SA contents don't change */ 647 isr = ipsec_nextisr(m, isr, AF_INET6, &saidx, &error); 648 if (isr == NULL) { 649 if (error != 0) { 650 #ifdef notdef 651 /* XXX should notification be done for all errors ? */ 652 /* 653 * Notify the fact that the packet is discarded 654 * to ourselves. I believe this is better than 655 * just silently discarding. (jinmei@kame.net) 656 * XXX: should we restrict the error to TCP packets? 657 * XXX: should we directly notify sockets via 658 * pfctlinputs? 659 */ 660 icmp6_error(m, ICMP6_DST_UNREACH, 661 ICMP6_DST_UNREACH_ADMIN, 0); 662 m = NULL; /* NB: icmp6_error frees mbuf */ 663 #endif 664 goto bad; 665 } 666 return EJUSTRETURN; 667 } 668 669 error = (*isr->sav->tdb_xform->xf_output)(m, isr, NULL, 670 sizeof (struct ip6_hdr), 671 offsetof(struct ip6_hdr, 672 ip6_nxt)); 673 IPSECREQUEST_UNLOCK(isr); 674 return error; 675 bad: 676 if (isr) 677 IPSECREQUEST_UNLOCK(isr); 678 if (m) 679 m_freem(m); 680 state->m = NULL; 681 return error; 682 } 683 684 static int 685 ipsec6_encapsulate(struct mbuf *m, struct secasvar *sav) 686 { 687 struct ip6_hdr *oip6; 688 struct ip6_hdr *ip6; 689 size_t plen; 690 691 /* can't tunnel between different AFs */ 692 if (sav->sah->saidx.src.sa.sa_family != AF_INET6 || 693 sav->sah->saidx.dst.sa.sa_family != AF_INET6) { 694 m_freem(m); 695 return EINVAL; 696 } 697 IPSEC_ASSERT(m->m_len == sizeof (struct ip6_hdr), 698 ("mbuf wrong size; len %u", m->m_len)); 699 700 701 /* 702 * grow the mbuf to accomodate the new IPv6 header. 703 */ 704 plen = m->m_pkthdr.len; 705 if (M_LEADINGSPACE(m->m_next) < sizeof(struct ip6_hdr)) { 706 struct mbuf *n; 707 MGET(n, M_DONTWAIT, MT_DATA); 708 if (!n) { 709 m_freem(m); 710 return ENOBUFS; 711 } 712 n->m_len = sizeof(struct ip6_hdr); 713 n->m_next = m->m_next; 714 m->m_next = n; 715 m->m_pkthdr.len += sizeof(struct ip6_hdr); 716 oip6 = mtod(n, struct ip6_hdr *); 717 } else { 718 m->m_next->m_len += sizeof(struct ip6_hdr); 719 m->m_next->m_data -= sizeof(struct ip6_hdr); 720 m->m_pkthdr.len += sizeof(struct ip6_hdr); 721 oip6 = mtod(m->m_next, struct ip6_hdr *); 722 } 723 ip6 = mtod(m, struct ip6_hdr *); 724 bcopy((caddr_t)ip6, (caddr_t)oip6, sizeof(struct ip6_hdr)); 725 726 /* Fake link-local scope-class addresses */ 727 if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_src)) 728 oip6->ip6_src.s6_addr16[1] = 0; 729 if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_dst)) 730 oip6->ip6_dst.s6_addr16[1] = 0; 731 732 /* construct new IPv6 header. see RFC 2401 5.1.2.2 */ 733 /* ECN consideration. */ 734 ip6_ecn_ingress(V_ip6_ipsec_ecn, &ip6->ip6_flow, &oip6->ip6_flow); 735 if (plen < IPV6_MAXPACKET - sizeof(struct ip6_hdr)) 736 ip6->ip6_plen = htons(plen); 737 else { 738 /* ip6->ip6_plen will be updated in ip6_output() */ 739 } 740 ip6->ip6_nxt = IPPROTO_IPV6; 741 ip6->ip6_src = sav->sah->saidx.src.sin6.sin6_addr; 742 ip6->ip6_dst = sav->sah->saidx.dst.sin6.sin6_addr; 743 ip6->ip6_hlim = IPV6_DEFHLIM; 744 745 /* XXX Should ip6_src be updated later ? */ 746 747 return 0; 748 } 749 750 /* 751 * IPsec output logic for IPv6, tunnel mode. 752 */ 753 int 754 ipsec6_output_tunnel(struct ipsec_output_state *state, struct secpolicy *sp, int flags) 755 { 756 struct ip6_hdr *ip6; 757 struct ipsecrequest *isr; 758 struct secasindex saidx; 759 int error; 760 struct sockaddr_in6 *dst6; 761 struct mbuf *m; 762 763 IPSEC_ASSERT(state != NULL, ("null state")); 764 IPSEC_ASSERT(state->m != NULL, ("null m")); 765 IPSEC_ASSERT(sp != NULL, ("null sp")); 766 767 KEYDEBUG(KEYDEBUG_IPSEC_DATA, 768 printf("%s: applied SP\n", __func__); 769 kdebug_secpolicy(sp)); 770 771 m = state->m; 772 /* 773 * transport mode ipsec (before the 1st tunnel mode) is already 774 * processed by ipsec6_output_trans(). 775 */ 776 for (isr = sp->req; isr; isr = isr->next) { 777 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) 778 break; 779 } 780 781 IPSECREQUEST_LOCK(isr); /* insure SA contents don't change */ 782 isr = ipsec_nextisr(m, isr, AF_INET6, &saidx, &error); 783 if (isr == NULL) { 784 if (error != 0) 785 goto bad; 786 return EJUSTRETURN; 787 } 788 789 #ifdef DEV_ENC 790 encif->if_opackets++; 791 encif->if_obytes += m->m_pkthdr.len; 792 793 /* pass the mbuf to enc0 for bpf processing */ 794 ipsec_bpf(m, isr->sav, AF_INET6, ENC_OUT|ENC_BEFORE); 795 /* pass the mbuf to enc0 for packet filtering */ 796 if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_BEFORE)) != 0) 797 goto bad; 798 #endif 799 800 /* 801 * There may be the case that SA status will be changed when 802 * we are refering to one. So calling splsoftnet(). 803 */ 804 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) { 805 /* 806 * build IPsec tunnel. 807 */ 808 /* XXX should be processed with other familiy */ 809 if (isr->sav->sah->saidx.src.sa.sa_family != AF_INET6) { 810 ipseclog((LOG_ERR, "%s: family mismatched between " 811 "inner and outer, spi=%u\n", __func__, 812 ntohl(isr->sav->spi))); 813 V_ipsec6stat.ips_out_inval++; 814 error = EAFNOSUPPORT; 815 goto bad; 816 } 817 818 m = ipsec6_splithdr(m); 819 if (!m) { 820 V_ipsec6stat.ips_out_nomem++; 821 error = ENOMEM; 822 goto bad; 823 } 824 error = ipsec6_encapsulate(m, isr->sav); 825 if (error) { 826 m = NULL; 827 goto bad; 828 } 829 ip6 = mtod(m, struct ip6_hdr *); 830 831 state->ro = 832 (struct route *)&isr->sav->sah->route_cache.sin6_route; 833 state->dst = (struct sockaddr *)&state->ro->ro_dst; 834 dst6 = (struct sockaddr_in6 *)state->dst; 835 if (state->ro->ro_rt 836 && ((state->ro->ro_rt->rt_flags & RTF_UP) == 0 837 || !IN6_ARE_ADDR_EQUAL(&dst6->sin6_addr, &ip6->ip6_dst))) { 838 RTFREE(state->ro->ro_rt); 839 state->ro->ro_rt = NULL; 840 } 841 if (state->ro->ro_rt == NULL) { 842 bzero(dst6, sizeof(*dst6)); 843 dst6->sin6_family = AF_INET6; 844 dst6->sin6_len = sizeof(*dst6); 845 dst6->sin6_addr = ip6->ip6_dst; 846 rtalloc(state->ro); 847 } 848 if (state->ro->ro_rt == NULL) { 849 V_ip6stat.ip6s_noroute++; 850 V_ipsec6stat.ips_out_noroute++; 851 error = EHOSTUNREACH; 852 goto bad; 853 } 854 855 /* adjust state->dst if tunnel endpoint is offlink */ 856 if (state->ro->ro_rt->rt_flags & RTF_GATEWAY) 857 state->dst = (struct sockaddr *)state->ro->ro_rt->rt_gateway; 858 } 859 860 m = ipsec6_splithdr(m); 861 if (!m) { 862 V_ipsec6stat.ips_out_nomem++; 863 error = ENOMEM; 864 goto bad; 865 } 866 ip6 = mtod(m, struct ip6_hdr *); 867 868 #ifdef DEV_ENC 869 /* pass the mbuf to enc0 for bpf processing */ 870 ipsec_bpf(m, isr->sav, AF_INET6, ENC_OUT|ENC_AFTER); 871 /* pass the mbuf to enc0 for packet filtering */ 872 if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_AFTER)) != 0) 873 goto bad; 874 #endif 875 876 error = (*isr->sav->tdb_xform->xf_output)(m, isr, NULL, 877 sizeof (struct ip6_hdr), 878 offsetof(struct ip6_hdr, ip6_nxt)); 879 IPSECREQUEST_UNLOCK(isr); 880 return error; 881 bad: 882 if (isr) 883 IPSECREQUEST_UNLOCK(isr); 884 if (m) 885 m_freem(m); 886 state->m = NULL; 887 return error; 888 } 889 #endif /*INET6*/ 890