1/*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2002, 2003 Sam Leffler, Errno Consulting 5 * Copyright (c) 2016 Andrey V. Elsukov <ae@FreeBSD.org> 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * $FreeBSD$ 30 */ 31 32/* 33 * IPsec output processing. 34 */ 35#include "opt_inet.h" 36#include "opt_inet6.h" 37#include "opt_ipsec.h" 38#include "opt_sctp.h" 39 40#include <sys/param.h> 41#include <sys/systm.h> 42#include <sys/mbuf.h> 43#include <sys/domain.h> 44#include <sys/protosw.h> 45#include <sys/socket.h> 46#include <sys/errno.h> 47#include <sys/hhook.h> 48#include <sys/syslog.h> 49 50#include <net/if.h> 51#include <net/if_enc.h> 52#include <net/if_var.h> 53#include <net/vnet.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#include <netinet6/ip6_ecn.h> 63#endif 64 65#include <netinet/ip6.h> 66#ifdef INET6 67#include <netinet6/ip6_var.h> 68#include <netinet6/scope6_var.h> 69#endif 70#include <netinet/in_pcb.h> 71#ifdef INET6 72#include <netinet/icmp6.h> 73#endif 74#if defined(SCTP) || defined(SCTP_SUPPORT) 75#include <netinet/sctp_crc32.h> 76#endif 77 78#include <netinet/udp.h> 79#include <netipsec/ah.h> 80#include <netipsec/esp.h> 81#include <netipsec/ipsec.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 95#include <machine/in_cksum.h> 96 97#define IPSEC_OSTAT_INC(proto, name) do { \ 98 if ((proto) == IPPROTO_ESP) \ 99 ESPSTAT_INC(esps_##name); \ 100 else if ((proto) == IPPROTO_AH)\ 101 AHSTAT_INC(ahs_##name); \ 102 else \ 103 IPCOMPSTAT_INC(ipcomps_##name); \ 104} while (0) 105 106static int ipsec_encap(struct mbuf **mp, struct secasindex *saidx); 107 108#ifdef INET 109static struct secasvar * 110ipsec4_allocsa(struct mbuf *m, struct secpolicy *sp, u_int *pidx, int *error) 111{ 112 struct secasindex *saidx, tmpsaidx; 113 struct ipsecrequest *isr; 114 struct sockaddr_in *sin; 115 struct secasvar *sav; 116 struct ip *ip; 117 118 /* 119 * Check system global policy controls. 120 */ 121next: 122 isr = sp->req[*pidx]; 123 if ((isr->saidx.proto == IPPROTO_ESP && !V_esp_enable) || 124 (isr->saidx.proto == IPPROTO_AH && !V_ah_enable) || 125 (isr->saidx.proto == IPPROTO_IPCOMP && !V_ipcomp_enable)) { 126 DPRINTF(("%s: IPsec outbound packet dropped due" 127 " to policy (check your sysctls)\n", __func__)); 128 IPSEC_OSTAT_INC(isr->saidx.proto, pdrops); 129 *error = EHOSTUNREACH; 130 return (NULL); 131 } 132 /* 133 * Craft SA index to search for proper SA. Note that 134 * we only initialize unspecified SA peers for transport 135 * mode; for tunnel mode they must already be filled in. 136 */ 137 if (isr->saidx.mode == IPSEC_MODE_TRANSPORT) { 138 saidx = &tmpsaidx; 139 *saidx = isr->saidx; 140 ip = mtod(m, struct ip *); 141 if (saidx->src.sa.sa_len == 0) { 142 sin = &saidx->src.sin; 143 sin->sin_len = sizeof(*sin); 144 sin->sin_family = AF_INET; 145 sin->sin_port = IPSEC_PORT_ANY; 146 sin->sin_addr = ip->ip_src; 147 } 148 if (saidx->dst.sa.sa_len == 0) { 149 sin = &saidx->dst.sin; 150 sin->sin_len = sizeof(*sin); 151 sin->sin_family = AF_INET; 152 sin->sin_port = IPSEC_PORT_ANY; 153 sin->sin_addr = ip->ip_dst; 154 } 155 } else 156 saidx = &sp->req[*pidx]->saidx; 157 /* 158 * Lookup SA and validate it. 159 */ 160 sav = key_allocsa_policy(sp, saidx, error); 161 if (sav == NULL) { 162 IPSECSTAT_INC(ips_out_nosa); 163 if (*error != 0) 164 return (NULL); 165 if (ipsec_get_reqlevel(sp, *pidx) != IPSEC_LEVEL_REQUIRE) { 166 /* 167 * We have no SA and policy that doesn't require 168 * this IPsec transform, thus we can continue w/o 169 * IPsec processing, i.e. return EJUSTRETURN. 170 * But first check if there is some bundled transform. 171 */ 172 if (sp->tcount > ++(*pidx)) 173 goto next; 174 *error = EJUSTRETURN; 175 } 176 return (NULL); 177 } 178 IPSEC_ASSERT(sav->tdb_xform != NULL, ("SA with NULL tdb_xform")); 179 return (sav); 180} 181 182/* 183 * IPsec output logic for IPv4. 184 */ 185static int 186ipsec4_perform_request(struct mbuf *m, struct secpolicy *sp, 187 struct inpcb *inp, u_int idx) 188{ 189 struct ipsec_ctx_data ctx; 190 union sockaddr_union *dst; 191 struct secasvar *sav; 192 struct ip *ip; 193 int error, i, off; 194 195 IPSEC_ASSERT(idx < sp->tcount, ("Wrong IPsec request index %d", idx)); 196 197 /* 198 * We hold the reference to SP. Content of SP couldn't be changed. 199 * Craft secasindex and do lookup for suitable SA. 200 * Then do encapsulation if needed and call xform's output. 201 * We need to store SP in the xform callback parameters. 202 * In xform callback we will extract SP and it can be used to 203 * determine next transform. At the end of transform we can 204 * release reference to SP. 205 */ 206 sav = ipsec4_allocsa(m, sp, &idx, &error); 207 if (sav == NULL) { 208 if (error == EJUSTRETURN) { /* No IPsec required */ 209 key_freesp(&sp); 210 return (error); 211 } 212 goto bad; 213 } 214 /* 215 * XXXAE: most likely ip_sum at this point is wrong. 216 */ 217 IPSEC_INIT_CTX(&ctx, &m, inp, sav, AF_INET, IPSEC_ENC_BEFORE); 218 if ((error = ipsec_run_hhooks(&ctx, HHOOK_TYPE_IPSEC_OUT)) != 0) 219 goto bad; 220 221 ip = mtod(m, struct ip *); 222 dst = &sav->sah->saidx.dst; 223 /* Do the appropriate encapsulation, if necessary */ 224 if (sp->req[idx]->saidx.mode == IPSEC_MODE_TUNNEL || /* Tunnel requ'd */ 225 dst->sa.sa_family != AF_INET || /* PF mismatch */ 226 (dst->sa.sa_family == AF_INET && /* Proxy */ 227 dst->sin.sin_addr.s_addr != INADDR_ANY && 228 dst->sin.sin_addr.s_addr != ip->ip_dst.s_addr)) { 229 /* Fix IPv4 header checksum and length */ 230 ip->ip_len = htons(m->m_pkthdr.len); 231 ip->ip_sum = 0; 232 ip->ip_sum = in_cksum(m, ip->ip_hl << 2); 233 error = ipsec_encap(&m, &sav->sah->saidx); 234 if (error != 0) { 235 DPRINTF(("%s: encapsulation for SPI 0x%08x failed " 236 "with error %d\n", __func__, ntohl(sav->spi), 237 error)); 238 /* XXXAE: IPSEC_OSTAT_INC(tunnel); */ 239 goto bad; 240 } 241 inp = NULL; 242 } 243 244 IPSEC_INIT_CTX(&ctx, &m, inp, sav, dst->sa.sa_family, IPSEC_ENC_AFTER); 245 if ((error = ipsec_run_hhooks(&ctx, HHOOK_TYPE_IPSEC_OUT)) != 0) 246 goto bad; 247 248 /* 249 * Dispatch to the appropriate IPsec transform logic. The 250 * packet will be returned for transmission after crypto 251 * processing, etc. are completed. 252 * 253 * NB: m & sav are ``passed to caller'' who's responsible for 254 * reclaiming their resources. 255 */ 256 switch(dst->sa.sa_family) { 257 case AF_INET: 258 ip = mtod(m, struct ip *); 259 i = ip->ip_hl << 2; 260 off = offsetof(struct ip, ip_p); 261 break; 262#ifdef INET6 263 case AF_INET6: 264 i = sizeof(struct ip6_hdr); 265 off = offsetof(struct ip6_hdr, ip6_nxt); 266 break; 267#endif /* INET6 */ 268 default: 269 DPRINTF(("%s: unsupported protocol family %u\n", 270 __func__, dst->sa.sa_family)); 271 error = EPFNOSUPPORT; 272 IPSEC_OSTAT_INC(sav->sah->saidx.proto, nopf); 273 goto bad; 274 } 275 error = (*sav->tdb_xform->xf_output)(m, sp, sav, idx, i, off); 276 return (error); 277bad: 278 IPSECSTAT_INC(ips_out_inval); 279 if (m != NULL) 280 m_freem(m); 281 if (sav != NULL) 282 key_freesav(&sav); 283 key_freesp(&sp); 284 return (error); 285} 286 287int 288ipsec4_process_packet(struct mbuf *m, struct secpolicy *sp, 289 struct inpcb *inp) 290{ 291 292 return (ipsec4_perform_request(m, sp, inp, 0)); 293} 294 295static int 296ipsec4_common_output(struct mbuf *m, struct inpcb *inp, int forwarding) 297{ 298 struct secpolicy *sp; 299 int error; 300 301 /* Lookup for the corresponding outbound security policy */ 302 sp = ipsec4_checkpolicy(m, inp, &error, !forwarding); 303 if (sp == NULL) { 304 if (error == -EINVAL) { 305 /* Discarded by policy. */ 306 m_freem(m); 307 return (EACCES); 308 } 309 return (0); /* No IPsec required. */ 310 } 311 312 /* 313 * Usually we have to have tunnel mode IPsec security policy 314 * when we are forwarding a packet. Otherwise we could not handle 315 * encrypted replies, because they are not destined for us. But 316 * some users are doing source address translation for forwarded 317 * packets, and thus, even if they are forwarded, the replies will 318 * return back to us. 319 */ 320 if (!forwarding) { 321 /* 322 * Do delayed checksums now because we send before 323 * this is done in the normal processing path. 324 */ 325 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 326 m = mb_unmapped_to_ext(m); 327 if (m == NULL) { 328 IPSECSTAT_INC(ips_out_nomem); 329 key_freesp(&sp); 330 return (ENOBUFS); 331 } 332 in_delayed_cksum(m); 333 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 334 } 335#if defined(SCTP) || defined(SCTP_SUPPORT) 336 if (m->m_pkthdr.csum_flags & CSUM_SCTP) { 337 struct ip *ip; 338 339 m = mb_unmapped_to_ext(m); 340 if (m == NULL) { 341 IPSECSTAT_INC(ips_out_nomem); 342 key_freesp(&sp); 343 return (ENOBUFS); 344 } 345 ip = mtod(m, struct ip *); 346 sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2)); 347 m->m_pkthdr.csum_flags &= ~CSUM_SCTP; 348 } 349#endif 350 } 351 /* NB: callee frees mbuf and releases reference to SP */ 352 error = ipsec4_process_packet(m, sp, inp); 353 if (error == EJUSTRETURN) { 354 /* 355 * We had a SP with a level of 'use' and no SA. We 356 * will just continue to process the packet without 357 * IPsec processing and return without error. 358 */ 359 return (0); 360 } 361 if (error == 0) 362 return (EINPROGRESS); /* consumed by IPsec */ 363 return (error); 364} 365 366/* 367 * IPSEC_OUTPUT() method implementation for IPv4. 368 * 0 - no IPsec handling needed 369 * other values - mbuf consumed by IPsec. 370 */ 371int 372ipsec4_output(struct mbuf *m, struct inpcb *inp) 373{ 374 375 /* 376 * If the packet is resubmitted to ip_output (e.g. after 377 * AH, ESP, etc. processing), there will be a tag to bypass 378 * the lookup and related policy checking. 379 */ 380 if (m_tag_find(m, PACKET_TAG_IPSEC_OUT_DONE, NULL) != NULL) 381 return (0); 382 383 return (ipsec4_common_output(m, inp, 0)); 384} 385 386/* 387 * IPSEC_FORWARD() method implementation for IPv4. 388 * 0 - no IPsec handling needed 389 * other values - mbuf consumed by IPsec. 390 */ 391int 392ipsec4_forward(struct mbuf *m) 393{ 394 395 /* 396 * Check if this packet has an active inbound SP and needs to be 397 * dropped instead of forwarded. 398 */ 399 if (ipsec4_in_reject(m, NULL) != 0) { 400 m_freem(m); 401 return (EACCES); 402 } 403 return (ipsec4_common_output(m, NULL, 1)); 404} 405#endif 406 407#ifdef INET6 408static int 409in6_sa_equal_addrwithscope(const struct sockaddr_in6 *sa, 410 const struct in6_addr *ia) 411{ 412 struct in6_addr ia2; 413 414 if (IN6_IS_SCOPE_LINKLOCAL(&sa->sin6_addr)) { 415 memcpy(&ia2, &sa->sin6_addr, sizeof(ia2)); 416 ia2.s6_addr16[1] = htons(sa->sin6_scope_id); 417 return (IN6_ARE_ADDR_EQUAL(ia, &ia2)); 418 } 419 return (IN6_ARE_ADDR_EQUAL(&sa->sin6_addr, ia)); 420} 421 422static struct secasvar * 423ipsec6_allocsa(struct mbuf *m, struct secpolicy *sp, u_int *pidx, int *error) 424{ 425 struct secasindex *saidx, tmpsaidx; 426 struct ipsecrequest *isr; 427 struct sockaddr_in6 *sin6; 428 struct secasvar *sav; 429 struct ip6_hdr *ip6; 430 431 /* 432 * Check system global policy controls. 433 */ 434next: 435 isr = sp->req[*pidx]; 436 if ((isr->saidx.proto == IPPROTO_ESP && !V_esp_enable) || 437 (isr->saidx.proto == IPPROTO_AH && !V_ah_enable) || 438 (isr->saidx.proto == IPPROTO_IPCOMP && !V_ipcomp_enable)) { 439 DPRINTF(("%s: IPsec outbound packet dropped due" 440 " to policy (check your sysctls)\n", __func__)); 441 IPSEC_OSTAT_INC(isr->saidx.proto, pdrops); 442 *error = EHOSTUNREACH; 443 return (NULL); 444 } 445 /* 446 * Craft SA index to search for proper SA. Note that 447 * we only fillin unspecified SA peers for transport 448 * mode; for tunnel mode they must already be filled in. 449 */ 450 if (isr->saidx.mode == IPSEC_MODE_TRANSPORT) { 451 saidx = &tmpsaidx; 452 *saidx = isr->saidx; 453 ip6 = mtod(m, struct ip6_hdr *); 454 if (saidx->src.sin6.sin6_len == 0) { 455 sin6 = (struct sockaddr_in6 *)&saidx->src; 456 sin6->sin6_len = sizeof(*sin6); 457 sin6->sin6_family = AF_INET6; 458 sin6->sin6_port = IPSEC_PORT_ANY; 459 sin6->sin6_addr = ip6->ip6_src; 460 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) { 461 /* fix scope id for comparing SPD */ 462 sin6->sin6_addr.s6_addr16[1] = 0; 463 sin6->sin6_scope_id = 464 ntohs(ip6->ip6_src.s6_addr16[1]); 465 } 466 } 467 if (saidx->dst.sin6.sin6_len == 0) { 468 sin6 = (struct sockaddr_in6 *)&saidx->dst; 469 sin6->sin6_len = sizeof(*sin6); 470 sin6->sin6_family = AF_INET6; 471 sin6->sin6_port = IPSEC_PORT_ANY; 472 sin6->sin6_addr = ip6->ip6_dst; 473 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) { 474 /* fix scope id for comparing SPD */ 475 sin6->sin6_addr.s6_addr16[1] = 0; 476 sin6->sin6_scope_id = 477 ntohs(ip6->ip6_dst.s6_addr16[1]); 478 } 479 } 480 } else 481 saidx = &sp->req[*pidx]->saidx; 482 /* 483 * Lookup SA and validate it. 484 */ 485 sav = key_allocsa_policy(sp, saidx, error); 486 if (sav == NULL) { 487 IPSEC6STAT_INC(ips_out_nosa); 488 if (*error != 0) 489 return (NULL); 490 if (ipsec_get_reqlevel(sp, *pidx) != IPSEC_LEVEL_REQUIRE) { 491 /* 492 * We have no SA and policy that doesn't require 493 * this IPsec transform, thus we can continue w/o 494 * IPsec processing, i.e. return EJUSTRETURN. 495 * But first check if there is some bundled transform. 496 */ 497 if (sp->tcount > ++(*pidx)) 498 goto next; 499 *error = EJUSTRETURN; 500 } 501 return (NULL); 502 } 503 IPSEC_ASSERT(sav->tdb_xform != NULL, ("SA with NULL tdb_xform")); 504 return (sav); 505} 506 507/* 508 * IPsec output logic for IPv6. 509 */ 510static int 511ipsec6_perform_request(struct mbuf *m, struct secpolicy *sp, 512 struct inpcb *inp, u_int idx) 513{ 514 struct ipsec_ctx_data ctx; 515 union sockaddr_union *dst; 516 struct secasvar *sav; 517 struct ip6_hdr *ip6; 518 int error, i, off; 519 520 IPSEC_ASSERT(idx < sp->tcount, ("Wrong IPsec request index %d", idx)); 521 522 sav = ipsec6_allocsa(m, sp, &idx, &error); 523 if (sav == NULL) { 524 if (error == EJUSTRETURN) { /* No IPsec required */ 525 key_freesp(&sp); 526 return (error); 527 } 528 goto bad; 529 } 530 531 /* Fix IP length in case if it is not set yet. */ 532 ip6 = mtod(m, struct ip6_hdr *); 533 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6)); 534 535 IPSEC_INIT_CTX(&ctx, &m, inp, sav, AF_INET6, IPSEC_ENC_BEFORE); 536 if ((error = ipsec_run_hhooks(&ctx, HHOOK_TYPE_IPSEC_OUT)) != 0) 537 goto bad; 538 539 ip6 = mtod(m, struct ip6_hdr *); /* pfil can change mbuf */ 540 dst = &sav->sah->saidx.dst; 541 542 /* Do the appropriate encapsulation, if necessary */ 543 if (sp->req[idx]->saidx.mode == IPSEC_MODE_TUNNEL || /* Tunnel requ'd */ 544 dst->sa.sa_family != AF_INET6 || /* PF mismatch */ 545 ((dst->sa.sa_family == AF_INET6) && 546 (!IN6_IS_ADDR_UNSPECIFIED(&dst->sin6.sin6_addr)) && 547 (!in6_sa_equal_addrwithscope(&dst->sin6, &ip6->ip6_dst)))) { 548 if (m->m_pkthdr.len - sizeof(*ip6) > IPV6_MAXPACKET) { 549 /* No jumbogram support. */ 550 error = ENXIO; /*XXX*/ 551 goto bad; 552 } 553 error = ipsec_encap(&m, &sav->sah->saidx); 554 if (error != 0) { 555 DPRINTF(("%s: encapsulation for SPI 0x%08x failed " 556 "with error %d\n", __func__, ntohl(sav->spi), 557 error)); 558 /* XXXAE: IPSEC_OSTAT_INC(tunnel); */ 559 goto bad; 560 } 561 inp = NULL; 562 } 563 564 IPSEC_INIT_CTX(&ctx, &m, inp, sav, dst->sa.sa_family, IPSEC_ENC_AFTER); 565 if ((error = ipsec_run_hhooks(&ctx, HHOOK_TYPE_IPSEC_OUT)) != 0) 566 goto bad; 567 568 switch(dst->sa.sa_family) { 569#ifdef INET 570 case AF_INET: 571 { 572 struct ip *ip; 573 ip = mtod(m, struct ip *); 574 i = ip->ip_hl << 2; 575 off = offsetof(struct ip, ip_p); 576 } 577 break; 578#endif /* AF_INET */ 579 case AF_INET6: 580 i = sizeof(struct ip6_hdr); 581 off = offsetof(struct ip6_hdr, ip6_nxt); 582 break; 583 default: 584 DPRINTF(("%s: unsupported protocol family %u\n", 585 __func__, dst->sa.sa_family)); 586 error = EPFNOSUPPORT; 587 IPSEC_OSTAT_INC(sav->sah->saidx.proto, nopf); 588 goto bad; 589 } 590 error = (*sav->tdb_xform->xf_output)(m, sp, sav, idx, i, off); 591 return (error); 592bad: 593 IPSEC6STAT_INC(ips_out_inval); 594 if (m != NULL) 595 m_freem(m); 596 if (sav != NULL) 597 key_freesav(&sav); 598 key_freesp(&sp); 599 return (error); 600} 601 602int 603ipsec6_process_packet(struct mbuf *m, struct secpolicy *sp, 604 struct inpcb *inp) 605{ 606 607 return (ipsec6_perform_request(m, sp, inp, 0)); 608} 609 610static int 611ipsec6_common_output(struct mbuf *m, struct inpcb *inp, int forwarding) 612{ 613 struct secpolicy *sp; 614 int error; 615 616 /* Lookup for the corresponding outbound security policy */ 617 sp = ipsec6_checkpolicy(m, inp, &error, !forwarding); 618 if (sp == NULL) { 619 if (error == -EINVAL) { 620 /* Discarded by policy. */ 621 m_freem(m); 622 return (EACCES); 623 } 624 return (0); /* No IPsec required. */ 625 } 626 627 if (!forwarding) { 628 /* 629 * Do delayed checksums now because we send before 630 * this is done in the normal processing path. 631 */ 632 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) { 633 m = mb_unmapped_to_ext(m); 634 if (m == NULL) { 635 IPSEC6STAT_INC(ips_out_nomem); 636 key_freesp(&sp); 637 return (ENOBUFS); 638 } 639 in6_delayed_cksum(m, m->m_pkthdr.len - 640 sizeof(struct ip6_hdr), sizeof(struct ip6_hdr)); 641 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA_IPV6; 642 } 643#if defined(SCTP) || defined(SCTP_SUPPORT) 644 if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6) { 645 m = mb_unmapped_to_ext(m); 646 if (m == NULL) { 647 IPSEC6STAT_INC(ips_out_nomem); 648 key_freesp(&sp); 649 return (ENOBUFS); 650 } 651 sctp_delayed_cksum(m, sizeof(struct ip6_hdr)); 652 m->m_pkthdr.csum_flags &= ~CSUM_SCTP_IPV6; 653 } 654#endif 655 } 656 /* NB: callee frees mbuf and releases reference to SP */ 657 error = ipsec6_process_packet(m, sp, inp); 658 if (error == EJUSTRETURN) { 659 /* 660 * We had a SP with a level of 'use' and no SA. We 661 * will just continue to process the packet without 662 * IPsec processing and return without error. 663 */ 664 return (0); 665 } 666 if (error == 0) 667 return (EINPROGRESS); /* consumed by IPsec */ 668 return (error); 669} 670 671/* 672 * IPSEC_OUTPUT() method implementation for IPv6. 673 * 0 - no IPsec handling needed 674 * other values - mbuf consumed by IPsec. 675 */ 676int 677ipsec6_output(struct mbuf *m, struct inpcb *inp) 678{ 679 680 /* 681 * If the packet is resubmitted to ip_output (e.g. after 682 * AH, ESP, etc. processing), there will be a tag to bypass 683 * the lookup and related policy checking. 684 */ 685 if (m_tag_find(m, PACKET_TAG_IPSEC_OUT_DONE, NULL) != NULL) 686 return (0); 687 688 return (ipsec6_common_output(m, inp, 0)); 689} 690 691/* 692 * IPSEC_FORWARD() method implementation for IPv6. 693 * 0 - no IPsec handling needed 694 * other values - mbuf consumed by IPsec. 695 */ 696int 697ipsec6_forward(struct mbuf *m) 698{ 699 700 /* 701 * Check if this packet has an active inbound SP and needs to be 702 * dropped instead of forwarded. 703 */ 704 if (ipsec6_in_reject(m, NULL) != 0) { 705 m_freem(m); 706 return (EACCES); 707 } 708 return (ipsec6_common_output(m, NULL, 1)); 709} 710#endif /* INET6 */ 711 712int 713ipsec_process_done(struct mbuf *m, struct secpolicy *sp, struct secasvar *sav, 714 u_int idx) 715{ 716 struct epoch_tracker et; 717 struct xform_history *xh; 718 struct secasindex *saidx; 719 struct m_tag *mtag; 720 int error; 721 722 saidx = &sav->sah->saidx; 723 switch (saidx->dst.sa.sa_family) { 724#ifdef INET 725 case AF_INET: 726 /* Fix the header length, for AH processing. */ 727 mtod(m, struct ip *)->ip_len = htons(m->m_pkthdr.len); 728 break; 729#endif /* INET */ 730#ifdef INET6 731 case AF_INET6: 732 /* Fix the header length, for AH processing. */ 733 if (m->m_pkthdr.len < sizeof (struct ip6_hdr)) { 734 error = ENXIO; 735 goto bad; 736 } 737 if (m->m_pkthdr.len - sizeof (struct ip6_hdr) > IPV6_MAXPACKET) { 738 /* No jumbogram support. */ 739 error = ENXIO; /*?*/ 740 goto bad; 741 } 742 mtod(m, struct ip6_hdr *)->ip6_plen = 743 htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 744 break; 745#endif /* INET6 */ 746 default: 747 DPRINTF(("%s: unknown protocol family %u\n", __func__, 748 saidx->dst.sa.sa_family)); 749 error = ENXIO; 750 goto bad; 751 } 752 753 /* 754 * Add a record of what we've done to the packet. 755 */ 756 mtag = m_tag_get(PACKET_TAG_IPSEC_OUT_DONE, sizeof(*xh), M_NOWAIT); 757 if (mtag == NULL) { 758 DPRINTF(("%s: could not get packet tag\n", __func__)); 759 error = ENOMEM; 760 goto bad; 761 } 762 763 xh = (struct xform_history *)(mtag + 1); 764 xh->dst = saidx->dst; 765 xh->proto = saidx->proto; 766 xh->mode = saidx->mode; 767 xh->spi = sav->spi; 768 m_tag_prepend(m, mtag); 769 770 key_sa_recordxfer(sav, m); /* record data transfer */ 771 772 /* 773 * If there's another (bundled) SA to apply, do so. 774 * Note that this puts a burden on the kernel stack size. 775 * If this is a problem we'll need to introduce a queue 776 * to set the packet on so we can unwind the stack before 777 * doing further processing. 778 */ 779 if (++idx < sp->tcount) { 780 switch (saidx->dst.sa.sa_family) { 781#ifdef INET 782 case AF_INET: 783 key_freesav(&sav); 784 IPSECSTAT_INC(ips_out_bundlesa); 785 return (ipsec4_perform_request(m, sp, NULL, idx)); 786 /* NOTREACHED */ 787#endif 788#ifdef INET6 789 case AF_INET6: 790 key_freesav(&sav); 791 IPSEC6STAT_INC(ips_out_bundlesa); 792 return (ipsec6_perform_request(m, sp, NULL, idx)); 793 /* NOTREACHED */ 794#endif /* INET6 */ 795 default: 796 DPRINTF(("%s: unknown protocol family %u\n", __func__, 797 saidx->dst.sa.sa_family)); 798 error = EPFNOSUPPORT; 799 goto bad; 800 } 801 } 802 803 key_freesp(&sp), sp = NULL; /* Release reference to SP */ 804#ifdef INET 805 /* 806 * Do UDP encapsulation if SA requires it. 807 */ 808 if (sav->natt != NULL) { 809 error = udp_ipsec_output(m, sav); 810 if (error != 0) 811 goto bad; 812 } 813#endif /* INET */ 814 /* 815 * We're done with IPsec processing, transmit the packet using the 816 * appropriate network protocol (IP or IPv6). 817 */ 818 NET_EPOCH_ENTER(et); 819 switch (saidx->dst.sa.sa_family) { 820#ifdef INET 821 case AF_INET: 822 key_freesav(&sav); 823 error = ip_output(m, NULL, NULL, IP_RAWOUTPUT, NULL, NULL); 824 break; 825#endif /* INET */ 826#ifdef INET6 827 case AF_INET6: 828 key_freesav(&sav); 829 error = ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL); 830 break; 831#endif /* INET6 */ 832 default: 833 panic("ipsec_process_done"); 834 } 835 NET_EPOCH_EXIT(et); 836 return (error); 837bad: 838 m_freem(m); 839 key_freesav(&sav); 840 if (sp != NULL) 841 key_freesp(&sp); 842 return (error); 843} 844 845/* 846 * ipsec_prepend() is optimized version of M_PREPEND(). 847 * ipsec_encap() is called by IPsec output routine for tunnel mode SA. 848 * It is expected that after IP encapsulation some IPsec transform will 849 * be performed. Each IPsec transform inserts its variable length header 850 * just after outer IP header using m_makespace(). If given mbuf has not 851 * enough free space at the beginning, we allocate new mbuf and reserve 852 * some space at the beginning and at the end. 853 * This helps avoid allocating of new mbuf and data copying in m_makespace(), 854 * we place outer header in the middle of mbuf's data with reserved leading 855 * and trailing space: 856 * [ LEADINGSPACE ][ Outer IP header ][ TRAILINGSPACE ] 857 * LEADINGSPACE will be used to add ethernet header, TRAILINGSPACE will 858 * be used to inject AH/ESP/IPCOMP header. 859 */ 860#define IPSEC_TRAILINGSPACE (sizeof(struct udphdr) +/* NAT-T */ \ 861 max(sizeof(struct newesp) + EALG_MAX_BLOCK_LEN, /* ESP + IV */ \ 862 sizeof(struct newah) + HASH_MAX_LEN /* AH + ICV */)) 863static struct mbuf * 864ipsec_prepend(struct mbuf *m, int len, int how) 865{ 866 struct mbuf *n; 867 868 M_ASSERTPKTHDR(m); 869 IPSEC_ASSERT(len < MHLEN, ("wrong length")); 870 if (M_LEADINGSPACE(m) >= len) { 871 /* No need to allocate new mbuf. */ 872 m->m_data -= len; 873 m->m_len += len; 874 m->m_pkthdr.len += len; 875 return (m); 876 } 877 n = m_gethdr(how, m->m_type); 878 if (n == NULL) { 879 m_freem(m); 880 return (NULL); 881 } 882 m_move_pkthdr(n, m); 883 n->m_next = m; 884 if (len + IPSEC_TRAILINGSPACE < M_SIZE(n)) 885 m_align(n, len + IPSEC_TRAILINGSPACE); 886 n->m_len = len; 887 n->m_pkthdr.len += len; 888 return (n); 889} 890 891static int 892ipsec_encap(struct mbuf **mp, struct secasindex *saidx) 893{ 894#ifdef INET6 895 struct ip6_hdr *ip6; 896#endif 897 struct ip *ip; 898 int setdf; 899 uint8_t itos, proto; 900 901 ip = mtod(*mp, struct ip *); 902 switch (ip->ip_v) { 903#ifdef INET 904 case IPVERSION: 905 proto = IPPROTO_IPIP; 906 /* 907 * Collect IP_DF state from the inner header 908 * and honor system-wide control of how to handle it. 909 */ 910 switch (V_ip4_ipsec_dfbit) { 911 case 0: /* clear in outer header */ 912 case 1: /* set in outer header */ 913 setdf = V_ip4_ipsec_dfbit; 914 break; 915 default:/* propagate to outer header */ 916 setdf = (ip->ip_off & htons(IP_DF)) != 0; 917 } 918 itos = ip->ip_tos; 919 break; 920#endif 921#ifdef INET6 922 case (IPV6_VERSION >> 4): 923 proto = IPPROTO_IPV6; 924 ip6 = mtod(*mp, struct ip6_hdr *); 925 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 926 setdf = V_ip4_ipsec_dfbit ? 1: 0; 927 /* scoped address handling */ 928 in6_clearscope(&ip6->ip6_src); 929 in6_clearscope(&ip6->ip6_dst); 930 break; 931#endif 932 default: 933 return (EAFNOSUPPORT); 934 } 935 switch (saidx->dst.sa.sa_family) { 936#ifdef INET 937 case AF_INET: 938 if (saidx->src.sa.sa_family != AF_INET || 939 saidx->src.sin.sin_addr.s_addr == INADDR_ANY || 940 saidx->dst.sin.sin_addr.s_addr == INADDR_ANY) 941 return (EINVAL); 942 *mp = ipsec_prepend(*mp, sizeof(struct ip), M_NOWAIT); 943 if (*mp == NULL) 944 return (ENOBUFS); 945 ip = mtod(*mp, struct ip *); 946 ip->ip_v = IPVERSION; 947 ip->ip_hl = sizeof(struct ip) >> 2; 948 ip->ip_p = proto; 949 ip->ip_len = htons((*mp)->m_pkthdr.len); 950 ip->ip_ttl = V_ip_defttl; 951 ip->ip_sum = 0; 952 ip->ip_off = setdf ? htons(IP_DF): 0; 953 ip->ip_src = saidx->src.sin.sin_addr; 954 ip->ip_dst = saidx->dst.sin.sin_addr; 955 ip_ecn_ingress(V_ip4_ipsec_ecn, &ip->ip_tos, &itos); 956 ip_fillid(ip); 957 break; 958#endif /* INET */ 959#ifdef INET6 960 case AF_INET6: 961 if (saidx->src.sa.sa_family != AF_INET6 || 962 IN6_IS_ADDR_UNSPECIFIED(&saidx->src.sin6.sin6_addr) || 963 IN6_IS_ADDR_UNSPECIFIED(&saidx->dst.sin6.sin6_addr)) 964 return (EINVAL); 965 *mp = ipsec_prepend(*mp, sizeof(struct ip6_hdr), M_NOWAIT); 966 if (*mp == NULL) 967 return (ENOBUFS); 968 ip6 = mtod(*mp, struct ip6_hdr *); 969 ip6->ip6_flow = 0; 970 ip6->ip6_vfc = IPV6_VERSION; 971 ip6->ip6_hlim = V_ip6_defhlim; 972 ip6->ip6_nxt = proto; 973 ip6->ip6_dst = saidx->dst.sin6.sin6_addr; 974 /* For link-local address embed scope zone id */ 975 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) 976 ip6->ip6_dst.s6_addr16[1] = 977 htons(saidx->dst.sin6.sin6_scope_id & 0xffff); 978 ip6->ip6_src = saidx->src.sin6.sin6_addr; 979 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) 980 ip6->ip6_src.s6_addr16[1] = 981 htons(saidx->src.sin6.sin6_scope_id & 0xffff); 982 ip6->ip6_plen = htons((*mp)->m_pkthdr.len - sizeof(*ip6)); 983 ip_ecn_ingress(V_ip6_ipsec_ecn, &proto, &itos); 984 ip6->ip6_flow |= htonl((uint32_t)proto << 20); 985 break; 986#endif /* INET6 */ 987 default: 988 return (EAFNOSUPPORT); 989 } 990 (*mp)->m_flags &= ~(M_BCAST | M_MCAST); 991 return (0); 992} 993