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sys/netipsec/ipsec_output.c
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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: releng/12.0/sys/netipsec/ipsec_output.c 326272 2017-11-27 15:23:17Z pfg $ 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 #ifdef SCTP 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) 105 106 static int ipsec_encap(struct mbuf **mp, struct secasindex *saidx); 107 108 #ifdef INET 109 static struct secasvar * 110 ipsec4_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 */ 121 next: 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 */ 185 static int 186 ipsec4_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); 277 bad: 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 } 286 287 int 288 ipsec4_process_packet(struct mbuf *m, struct secpolicy *sp, 289 struct inpcb *inp) 290 { 291 292 return (ipsec4_perform_request(m, sp, inp, 0)); 293 } 294 295 static int 296 ipsec4_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 in_delayed_cksum(m); 327 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 328 } 329 #ifdef SCTP 330 if (m->m_pkthdr.csum_flags & CSUM_SCTP) { 331 struct ip *ip = mtod(m, struct ip *); 332 333 sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2)); 334 m->m_pkthdr.csum_flags &= ~CSUM_SCTP; 335 } 336 #endif 337 } 338 /* NB: callee frees mbuf and releases reference to SP */ 339 error = ipsec4_process_packet(m, sp, inp); 340 if (error == EJUSTRETURN) { 341 /* 342 * We had a SP with a level of 'use' and no SA. We 343 * will just continue to process the packet without 344 * IPsec processing and return without error. 345 */ 346 return (0); 347 } 348 if (error == 0) 349 return (EINPROGRESS); /* consumed by IPsec */ 350 return (error); 351 } 352 353 /* 354 * IPSEC_OUTPUT() method implementation for IPv4. 355 * 0 - no IPsec handling needed 356 * other values - mbuf consumed by IPsec. 357 */ 358 int 359 ipsec4_output(struct mbuf *m, struct inpcb *inp) 360 { 361 362 /* 363 * If the packet is resubmitted to ip_output (e.g. after 364 * AH, ESP, etc. processing), there will be a tag to bypass 365 * the lookup and related policy checking. 366 */ 367 if (m_tag_find(m, PACKET_TAG_IPSEC_OUT_DONE, NULL) != NULL) 368 return (0); 369 370 return (ipsec4_common_output(m, inp, 0)); 371 } 372 373 /* 374 * IPSEC_FORWARD() method implementation for IPv4. 375 * 0 - no IPsec handling needed 376 * other values - mbuf consumed by IPsec. 377 */ 378 int 379 ipsec4_forward(struct mbuf *m) 380 { 381 382 /* 383 * Check if this packet has an active inbound SP and needs to be 384 * dropped instead of forwarded. 385 */ 386 if (ipsec4_in_reject(m, NULL) != 0) { 387 m_freem(m); 388 return (EACCES); 389 } 390 return (ipsec4_common_output(m, NULL, 1)); 391 } 392 #endif 393 394 #ifdef INET6 395 static int 396 in6_sa_equal_addrwithscope(const struct sockaddr_in6 *sa, 397 const struct in6_addr *ia) 398 { 399 struct in6_addr ia2; 400 401 if (IN6_IS_SCOPE_LINKLOCAL(&sa->sin6_addr)) { 402 memcpy(&ia2, &sa->sin6_addr, sizeof(ia2)); 403 ia2.s6_addr16[1] = htons(sa->sin6_scope_id); 404 return (IN6_ARE_ADDR_EQUAL(ia, &ia2)); 405 } 406 return (IN6_ARE_ADDR_EQUAL(&sa->sin6_addr, ia)); 407 } 408 409 static struct secasvar * 410 ipsec6_allocsa(struct mbuf *m, struct secpolicy *sp, u_int *pidx, int *error) 411 { 412 struct secasindex *saidx, tmpsaidx; 413 struct ipsecrequest *isr; 414 struct sockaddr_in6 *sin6; 415 struct secasvar *sav; 416 struct ip6_hdr *ip6; 417 418 /* 419 * Check system global policy controls. 420 */ 421 next: 422 isr = sp->req[*pidx]; 423 if ((isr->saidx.proto == IPPROTO_ESP && !V_esp_enable) || 424 (isr->saidx.proto == IPPROTO_AH && !V_ah_enable) || 425 (isr->saidx.proto == IPPROTO_IPCOMP && !V_ipcomp_enable)) { 426 DPRINTF(("%s: IPsec outbound packet dropped due" 427 " to policy (check your sysctls)\n", __func__)); 428 IPSEC_OSTAT_INC(isr->saidx.proto, pdrops); 429 *error = EHOSTUNREACH; 430 return (NULL); 431 } 432 /* 433 * Craft SA index to search for proper SA. Note that 434 * we only fillin unspecified SA peers for transport 435 * mode; for tunnel mode they must already be filled in. 436 */ 437 if (isr->saidx.mode == IPSEC_MODE_TRANSPORT) { 438 saidx = &tmpsaidx; 439 *saidx = isr->saidx; 440 ip6 = mtod(m, struct ip6_hdr *); 441 if (saidx->src.sin6.sin6_len == 0) { 442 sin6 = (struct sockaddr_in6 *)&saidx->src; 443 sin6->sin6_len = sizeof(*sin6); 444 sin6->sin6_family = AF_INET6; 445 sin6->sin6_port = IPSEC_PORT_ANY; 446 sin6->sin6_addr = ip6->ip6_src; 447 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) { 448 /* fix scope id for comparing SPD */ 449 sin6->sin6_addr.s6_addr16[1] = 0; 450 sin6->sin6_scope_id = 451 ntohs(ip6->ip6_src.s6_addr16[1]); 452 } 453 } 454 if (saidx->dst.sin6.sin6_len == 0) { 455 sin6 = (struct sockaddr_in6 *)&saidx->dst; 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_dst; 460 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) { 461 /* fix scope id for comparing SPD */ 462 sin6->sin6_addr.s6_addr16[1] = 0; 463 sin6->sin6_scope_id = 464 ntohs(ip6->ip6_dst.s6_addr16[1]); 465 } 466 } 467 } else 468 saidx = &sp->req[*pidx]->saidx; 469 /* 470 * Lookup SA and validate it. 471 */ 472 sav = key_allocsa_policy(sp, saidx, error); 473 if (sav == NULL) { 474 IPSEC6STAT_INC(ips_out_nosa); 475 if (*error != 0) 476 return (NULL); 477 if (ipsec_get_reqlevel(sp, *pidx) != IPSEC_LEVEL_REQUIRE) { 478 /* 479 * We have no SA and policy that doesn't require 480 * this IPsec transform, thus we can continue w/o 481 * IPsec processing, i.e. return EJUSTRETURN. 482 * But first check if there is some bundled transform. 483 */ 484 if (sp->tcount > ++(*pidx)) 485 goto next; 486 *error = EJUSTRETURN; 487 } 488 return (NULL); 489 } 490 IPSEC_ASSERT(sav->tdb_xform != NULL, ("SA with NULL tdb_xform")); 491 return (sav); 492 } 493 494 /* 495 * IPsec output logic for IPv6. 496 */ 497 static int 498 ipsec6_perform_request(struct mbuf *m, struct secpolicy *sp, 499 struct inpcb *inp, u_int idx) 500 { 501 struct ipsec_ctx_data ctx; 502 union sockaddr_union *dst; 503 struct secasvar *sav; 504 struct ip6_hdr *ip6; 505 int error, i, off; 506 507 IPSEC_ASSERT(idx < sp->tcount, ("Wrong IPsec request index %d", idx)); 508 509 sav = ipsec6_allocsa(m, sp, &idx, &error); 510 if (sav == NULL) { 511 if (error == EJUSTRETURN) { /* No IPsec required */ 512 key_freesp(&sp); 513 return (error); 514 } 515 goto bad; 516 } 517 518 /* Fix IP length in case if it is not set yet. */ 519 ip6 = mtod(m, struct ip6_hdr *); 520 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6)); 521 522 IPSEC_INIT_CTX(&ctx, &m, inp, sav, AF_INET6, IPSEC_ENC_BEFORE); 523 if ((error = ipsec_run_hhooks(&ctx, HHOOK_TYPE_IPSEC_OUT)) != 0) 524 goto bad; 525 526 ip6 = mtod(m, struct ip6_hdr *); /* pfil can change mbuf */ 527 dst = &sav->sah->saidx.dst; 528 529 /* Do the appropriate encapsulation, if necessary */ 530 if (sp->req[idx]->saidx.mode == IPSEC_MODE_TUNNEL || /* Tunnel requ'd */ 531 dst->sa.sa_family != AF_INET6 || /* PF mismatch */ 532 ((dst->sa.sa_family == AF_INET6) && 533 (!IN6_IS_ADDR_UNSPECIFIED(&dst->sin6.sin6_addr)) && 534 (!in6_sa_equal_addrwithscope(&dst->sin6, &ip6->ip6_dst)))) { 535 if (m->m_pkthdr.len - sizeof(*ip6) > IPV6_MAXPACKET) { 536 /* No jumbogram support. */ 537 error = ENXIO; /*XXX*/ 538 goto bad; 539 } 540 error = ipsec_encap(&m, &sav->sah->saidx); 541 if (error != 0) { 542 DPRINTF(("%s: encapsulation for SPI 0x%08x failed " 543 "with error %d\n", __func__, ntohl(sav->spi), 544 error)); 545 /* XXXAE: IPSEC_OSTAT_INC(tunnel); */ 546 goto bad; 547 } 548 inp = NULL; 549 } 550 551 IPSEC_INIT_CTX(&ctx, &m, inp, sav, dst->sa.sa_family, IPSEC_ENC_AFTER); 552 if ((error = ipsec_run_hhooks(&ctx, HHOOK_TYPE_IPSEC_OUT)) != 0) 553 goto bad; 554 555 switch(dst->sa.sa_family) { 556 #ifdef INET 557 case AF_INET: 558 { 559 struct ip *ip; 560 ip = mtod(m, struct ip *); 561 i = ip->ip_hl << 2; 562 off = offsetof(struct ip, ip_p); 563 } 564 break; 565 #endif /* AF_INET */ 566 case AF_INET6: 567 i = sizeof(struct ip6_hdr); 568 off = offsetof(struct ip6_hdr, ip6_nxt); 569 break; 570 default: 571 DPRINTF(("%s: unsupported protocol family %u\n", 572 __func__, dst->sa.sa_family)); 573 error = EPFNOSUPPORT; 574 IPSEC_OSTAT_INC(sav->sah->saidx.proto, nopf); 575 goto bad; 576 } 577 error = (*sav->tdb_xform->xf_output)(m, sp, sav, idx, i, off); 578 return (error); 579 bad: 580 IPSEC6STAT_INC(ips_out_inval); 581 if (m != NULL) 582 m_freem(m); 583 if (sav != NULL) 584 key_freesav(&sav); 585 key_freesp(&sp); 586 return (error); 587 } 588 589 int 590 ipsec6_process_packet(struct mbuf *m, struct secpolicy *sp, 591 struct inpcb *inp) 592 { 593 594 return (ipsec6_perform_request(m, sp, inp, 0)); 595 } 596 597 static int 598 ipsec6_common_output(struct mbuf *m, struct inpcb *inp, int forwarding) 599 { 600 struct secpolicy *sp; 601 int error; 602 603 /* Lookup for the corresponding outbound security policy */ 604 sp = ipsec6_checkpolicy(m, inp, &error, !forwarding); 605 if (sp == NULL) { 606 if (error == -EINVAL) { 607 /* Discarded by policy. */ 608 m_freem(m); 609 return (EACCES); 610 } 611 return (0); /* No IPsec required. */ 612 } 613 614 if (!forwarding) { 615 /* 616 * Do delayed checksums now because we send before 617 * this is done in the normal processing path. 618 */ 619 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) { 620 in6_delayed_cksum(m, m->m_pkthdr.len - 621 sizeof(struct ip6_hdr), sizeof(struct ip6_hdr)); 622 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA_IPV6; 623 } 624 #ifdef SCTP 625 if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6) { 626 sctp_delayed_cksum(m, sizeof(struct ip6_hdr)); 627 m->m_pkthdr.csum_flags &= ~CSUM_SCTP_IPV6; 628 } 629 #endif 630 } 631 /* NB: callee frees mbuf and releases reference to SP */ 632 error = ipsec6_process_packet(m, sp, inp); 633 if (error == EJUSTRETURN) { 634 /* 635 * We had a SP with a level of 'use' and no SA. We 636 * will just continue to process the packet without 637 * IPsec processing and return without error. 638 */ 639 return (0); 640 } 641 if (error == 0) 642 return (EINPROGRESS); /* consumed by IPsec */ 643 return (error); 644 } 645 646 /* 647 * IPSEC_OUTPUT() method implementation for IPv6. 648 * 0 - no IPsec handling needed 649 * other values - mbuf consumed by IPsec. 650 */ 651 int 652 ipsec6_output(struct mbuf *m, struct inpcb *inp) 653 { 654 655 /* 656 * If the packet is resubmitted to ip_output (e.g. after 657 * AH, ESP, etc. processing), there will be a tag to bypass 658 * the lookup and related policy checking. 659 */ 660 if (m_tag_find(m, PACKET_TAG_IPSEC_OUT_DONE, NULL) != NULL) 661 return (0); 662 663 return (ipsec6_common_output(m, inp, 0)); 664 } 665 666 /* 667 * IPSEC_FORWARD() method implementation for IPv6. 668 * 0 - no IPsec handling needed 669 * other values - mbuf consumed by IPsec. 670 */ 671 int 672 ipsec6_forward(struct mbuf *m) 673 { 674 675 /* 676 * Check if this packet has an active inbound SP and needs to be 677 * dropped instead of forwarded. 678 */ 679 if (ipsec6_in_reject(m, NULL) != 0) { 680 m_freem(m); 681 return (EACCES); 682 } 683 return (ipsec6_common_output(m, NULL, 1)); 684 } 685 #endif /* INET6 */ 686 687 int 688 ipsec_process_done(struct mbuf *m, struct secpolicy *sp, struct secasvar *sav, 689 u_int idx) 690 { 691 struct xform_history *xh; 692 struct secasindex *saidx; 693 struct m_tag *mtag; 694 int error; 695 696 saidx = &sav->sah->saidx; 697 switch (saidx->dst.sa.sa_family) { 698 #ifdef INET 699 case AF_INET: 700 /* Fix the header length, for AH processing. */ 701 mtod(m, struct ip *)->ip_len = htons(m->m_pkthdr.len); 702 break; 703 #endif /* INET */ 704 #ifdef INET6 705 case AF_INET6: 706 /* Fix the header length, for AH processing. */ 707 if (m->m_pkthdr.len < sizeof (struct ip6_hdr)) { 708 error = ENXIO; 709 goto bad; 710 } 711 if (m->m_pkthdr.len - sizeof (struct ip6_hdr) > IPV6_MAXPACKET) { 712 /* No jumbogram support. */ 713 error = ENXIO; /*?*/ 714 goto bad; 715 } 716 mtod(m, struct ip6_hdr *)->ip6_plen = 717 htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); 718 break; 719 #endif /* INET6 */ 720 default: 721 DPRINTF(("%s: unknown protocol family %u\n", __func__, 722 saidx->dst.sa.sa_family)); 723 error = ENXIO; 724 goto bad; 725 } 726 727 /* 728 * Add a record of what we've done to the packet. 729 */ 730 mtag = m_tag_get(PACKET_TAG_IPSEC_OUT_DONE, sizeof(*xh), M_NOWAIT); 731 if (mtag == NULL) { 732 DPRINTF(("%s: could not get packet tag\n", __func__)); 733 error = ENOMEM; 734 goto bad; 735 } 736 737 xh = (struct xform_history *)(mtag + 1); 738 xh->dst = saidx->dst; 739 xh->proto = saidx->proto; 740 xh->mode = saidx->mode; 741 xh->spi = sav->spi; 742 m_tag_prepend(m, mtag); 743 744 key_sa_recordxfer(sav, m); /* record data transfer */ 745 746 /* 747 * If there's another (bundled) SA to apply, do so. 748 * Note that this puts a burden on the kernel stack size. 749 * If this is a problem we'll need to introduce a queue 750 * to set the packet on so we can unwind the stack before 751 * doing further processing. 752 */ 753 if (++idx < sp->tcount) { 754 switch (saidx->dst.sa.sa_family) { 755 #ifdef INET 756 case AF_INET: 757 key_freesav(&sav); 758 IPSECSTAT_INC(ips_out_bundlesa); 759 return (ipsec4_perform_request(m, sp, NULL, idx)); 760 /* NOTREACHED */ 761 #endif 762 #ifdef INET6 763 case AF_INET6: 764 key_freesav(&sav); 765 IPSEC6STAT_INC(ips_out_bundlesa); 766 return (ipsec6_perform_request(m, sp, NULL, idx)); 767 /* NOTREACHED */ 768 #endif /* INET6 */ 769 default: 770 DPRINTF(("%s: unknown protocol family %u\n", __func__, 771 saidx->dst.sa.sa_family)); 772 error = EPFNOSUPPORT; 773 goto bad; 774 } 775 } 776 777 key_freesp(&sp), sp = NULL; /* Release reference to SP */ 778 #ifdef INET 779 /* 780 * Do UDP encapsulation if SA requires it. 781 */ 782 if (sav->natt != NULL) { 783 error = udp_ipsec_output(m, sav); 784 if (error != 0) 785 goto bad; 786 } 787 #endif /* INET */ 788 /* 789 * We're done with IPsec processing, transmit the packet using the 790 * appropriate network protocol (IP or IPv6). 791 */ 792 switch (saidx->dst.sa.sa_family) { 793 #ifdef INET 794 case AF_INET: 795 key_freesav(&sav); 796 return ip_output(m, NULL, NULL, IP_RAWOUTPUT, NULL, NULL); 797 #endif /* INET */ 798 #ifdef INET6 799 case AF_INET6: 800 key_freesav(&sav); 801 return ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL); 802 #endif /* INET6 */ 803 } 804 panic("ipsec_process_done"); 805 bad: 806 m_freem(m); 807 key_freesav(&sav); 808 if (sp != NULL) 809 key_freesp(&sp); 810 return (error); 811 } 812 813 /* 814 * ipsec_prepend() is optimized version of M_PREPEND(). 815 * ipsec_encap() is called by IPsec output routine for tunnel mode SA. 816 * It is expected that after IP encapsulation some IPsec transform will 817 * be performed. Each IPsec transform inserts its variable length header 818 * just after outer IP header using m_makespace(). If given mbuf has not 819 * enough free space at the beginning, we allocate new mbuf and reserve 820 * some space at the beginning and at the end. 821 * This helps avoid allocating of new mbuf and data copying in m_makespace(), 822 * we place outer header in the middle of mbuf's data with reserved leading 823 * and trailing space: 824 * [ LEADINGSPACE ][ Outer IP header ][ TRAILINGSPACE ] 825 * LEADINGSPACE will be used to add ethernet header, TRAILINGSPACE will 826 * be used to inject AH/ESP/IPCOMP header. 827 */ 828 #define IPSEC_TRAILINGSPACE (sizeof(struct udphdr) +/* NAT-T */ \ 829 max(sizeof(struct newesp) + EALG_MAX_BLOCK_LEN, /* ESP + IV */ \ 830 sizeof(struct newah) + HASH_MAX_LEN /* AH + ICV */)) 831 static struct mbuf * 832 ipsec_prepend(struct mbuf *m, int len, int how) 833 { 834 struct mbuf *n; 835 836 M_ASSERTPKTHDR(m); 837 IPSEC_ASSERT(len < MHLEN, ("wrong length")); 838 if (M_LEADINGSPACE(m) >= len) { 839 /* No need to allocate new mbuf. */ 840 m->m_data -= len; 841 m->m_len += len; 842 m->m_pkthdr.len += len; 843 return (m); 844 } 845 n = m_gethdr(how, m->m_type); 846 if (n == NULL) { 847 m_freem(m); 848 return (NULL); 849 } 850 m_move_pkthdr(n, m); 851 n->m_next = m; 852 if (len + IPSEC_TRAILINGSPACE < M_SIZE(n)) 853 m_align(n, len + IPSEC_TRAILINGSPACE); 854 n->m_len = len; 855 n->m_pkthdr.len += len; 856 return (n); 857 } 858 859 static int 860 ipsec_encap(struct mbuf **mp, struct secasindex *saidx) 861 { 862 #ifdef INET6 863 struct ip6_hdr *ip6; 864 #endif 865 struct ip *ip; 866 int setdf; 867 uint8_t itos, proto; 868 869 ip = mtod(*mp, struct ip *); 870 switch (ip->ip_v) { 871 #ifdef INET 872 case IPVERSION: 873 proto = IPPROTO_IPIP; 874 /* 875 * Collect IP_DF state from the inner header 876 * and honor system-wide control of how to handle it. 877 */ 878 switch (V_ip4_ipsec_dfbit) { 879 case 0: /* clear in outer header */ 880 case 1: /* set in outer header */ 881 setdf = V_ip4_ipsec_dfbit; 882 break; 883 default:/* propagate to outer header */ 884 setdf = (ip->ip_off & htons(IP_DF)) != 0; 885 } 886 itos = ip->ip_tos; 887 break; 888 #endif 889 #ifdef INET6 890 case (IPV6_VERSION >> 4): 891 proto = IPPROTO_IPV6; 892 ip6 = mtod(*mp, struct ip6_hdr *); 893 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 894 setdf = V_ip4_ipsec_dfbit ? 1: 0; 895 /* scoped address handling */ 896 in6_clearscope(&ip6->ip6_src); 897 in6_clearscope(&ip6->ip6_dst); 898 break; 899 #endif 900 default: 901 return (EAFNOSUPPORT); 902 } 903 switch (saidx->dst.sa.sa_family) { 904 #ifdef INET 905 case AF_INET: 906 if (saidx->src.sa.sa_family != AF_INET || 907 saidx->src.sin.sin_addr.s_addr == INADDR_ANY || 908 saidx->dst.sin.sin_addr.s_addr == INADDR_ANY) 909 return (EINVAL); 910 *mp = ipsec_prepend(*mp, sizeof(struct ip), M_NOWAIT); 911 if (*mp == NULL) 912 return (ENOBUFS); 913 ip = mtod(*mp, struct ip *); 914 ip->ip_v = IPVERSION; 915 ip->ip_hl = sizeof(struct ip) >> 2; 916 ip->ip_p = proto; 917 ip->ip_len = htons((*mp)->m_pkthdr.len); 918 ip->ip_ttl = V_ip_defttl; 919 ip->ip_sum = 0; 920 ip->ip_off = setdf ? htons(IP_DF): 0; 921 ip->ip_src = saidx->src.sin.sin_addr; 922 ip->ip_dst = saidx->dst.sin.sin_addr; 923 ip_ecn_ingress(V_ip4_ipsec_ecn, &ip->ip_tos, &itos); 924 ip_fillid(ip); 925 break; 926 #endif /* INET */ 927 #ifdef INET6 928 case AF_INET6: 929 if (saidx->src.sa.sa_family != AF_INET6 || 930 IN6_IS_ADDR_UNSPECIFIED(&saidx->src.sin6.sin6_addr) || 931 IN6_IS_ADDR_UNSPECIFIED(&saidx->dst.sin6.sin6_addr)) 932 return (EINVAL); 933 *mp = ipsec_prepend(*mp, sizeof(struct ip6_hdr), M_NOWAIT); 934 if (*mp == NULL) 935 return (ENOBUFS); 936 ip6 = mtod(*mp, struct ip6_hdr *); 937 ip6->ip6_flow = 0; 938 ip6->ip6_vfc = IPV6_VERSION; 939 ip6->ip6_hlim = V_ip6_defhlim; 940 ip6->ip6_nxt = proto; 941 ip6->ip6_dst = saidx->dst.sin6.sin6_addr; 942 /* For link-local address embed scope zone id */ 943 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) 944 ip6->ip6_dst.s6_addr16[1] = 945 htons(saidx->dst.sin6.sin6_scope_id & 0xffff); 946 ip6->ip6_src = saidx->src.sin6.sin6_addr; 947 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) 948 ip6->ip6_src.s6_addr16[1] = 949 htons(saidx->src.sin6.sin6_scope_id & 0xffff); 950 ip6->ip6_plen = htons((*mp)->m_pkthdr.len - sizeof(*ip6)); 951 ip_ecn_ingress(V_ip6_ipsec_ecn, &proto, &itos); 952 ip6->ip6_flow |= htonl((uint32_t)proto << 20); 953 break; 954 #endif /* INET6 */ 955 default: 956 return (EAFNOSUPPORT); 957 } 958 (*mp)->m_flags &= ~(M_BCAST | M_MCAST); 959 return (0); 960 } 961
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