ipsec.c revision 1.159
1 /* $NetBSD: ipsec.c,v 1.159 2018/04/28 14:21:03 maxv Exp $ */ 2 /* $FreeBSD: ipsec.c,v 1.2.2.2 2003/07/01 01:38:13 sam Exp $ */ 3 /* $KAME: ipsec.c,v 1.103 2001/05/24 07:14:18 sakane Exp $ */ 4 5 /* 6 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. Neither the name of the project nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #include <sys/cdefs.h> 35 __KERNEL_RCSID(0, "$NetBSD: ipsec.c,v 1.159 2018/04/28 14:21:03 maxv Exp $"); 36 37 /* 38 * IPsec controller part. 39 */ 40 41 #if defined(_KERNEL_OPT) 42 #include "opt_inet.h" 43 #include "opt_ipsec.h" 44 #endif 45 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 #include <sys/mbuf.h> 49 #include <sys/domain.h> 50 #include <sys/protosw.h> 51 #include <sys/socket.h> 52 #include <sys/socketvar.h> 53 #include <sys/errno.h> 54 #include <sys/time.h> 55 #include <sys/kernel.h> 56 #include <sys/syslog.h> 57 #include <sys/sysctl.h> 58 #include <sys/proc.h> 59 #include <sys/kauth.h> 60 #include <sys/cpu.h> 61 #include <sys/kmem.h> 62 #include <sys/pserialize.h> 63 64 #include <net/if.h> 65 #include <net/route.h> 66 67 #include <netinet/in.h> 68 #include <netinet/in_systm.h> 69 #include <netinet/ip.h> 70 #include <netinet/ip_var.h> 71 #include <netinet/in_var.h> 72 #include <netinet/udp.h> 73 #include <netinet/udp_var.h> 74 #include <netinet/tcp.h> 75 #include <netinet/udp.h> 76 #include <netinet/ip_icmp.h> 77 #include <netinet/ip_private.h> 78 79 #include <netinet/ip6.h> 80 #ifdef INET6 81 #include <netinet6/ip6_var.h> 82 #endif 83 #include <netinet/in_pcb.h> 84 #ifdef INET6 85 #include <netinet6/in6_pcb.h> 86 #include <netinet/icmp6.h> 87 #endif 88 89 #include <netipsec/ipsec.h> 90 #include <netipsec/ipsec_var.h> 91 #include <netipsec/ipsec_private.h> 92 #ifdef INET6 93 #include <netipsec/ipsec6.h> 94 #endif 95 #include <netipsec/ah_var.h> 96 #include <netipsec/esp_var.h> 97 #include <netipsec/ipcomp.h> /*XXX*/ 98 #include <netipsec/ipcomp_var.h> 99 100 #include <netipsec/key.h> 101 #include <netipsec/keydb.h> 102 #include <netipsec/key_debug.h> 103 104 #include <netipsec/xform.h> 105 106 int ipsec_used = 0; 107 int ipsec_enabled = 1; 108 109 #ifdef IPSEC_DEBUG 110 int ipsec_debug = 1; 111 112 /* 113 * When set to 1, IPsec will send packets with the same sequence number. 114 * This allows to verify if the other side has proper replay attacks detection. 115 */ 116 int ipsec_replay = 0; 117 118 /* 119 * When set 1, IPsec will send packets with corrupted HMAC. 120 * This allows to verify if the other side properly detects modified packets. 121 */ 122 int ipsec_integrity = 0; 123 #else 124 int ipsec_debug = 0; 125 #endif 126 127 percpu_t *ipsecstat_percpu; 128 129 int ip4_ah_offsetmask = 0; /* maybe IP_DF? */ 130 int ip4_ipsec_dfbit = 2; /* DF bit on encap. 0: clear 1: set 2: copy */ 131 int ip4_esp_trans_deflev = IPSEC_LEVEL_USE; 132 int ip4_esp_net_deflev = IPSEC_LEVEL_USE; 133 int ip4_ah_trans_deflev = IPSEC_LEVEL_USE; 134 int ip4_ah_net_deflev = IPSEC_LEVEL_USE; 135 struct secpolicy ip4_def_policy; 136 int ip4_ipsec_ecn = 0; /* ECN ignore(-1)/forbidden(0)/allowed(1) */ 137 138 u_int ipsec_spdgen = 1; /* SPD generation # */ 139 140 static struct secpolicy ipsec_dummy_sp __read_mostly = { 141 .state = IPSEC_SPSTATE_ALIVE, 142 /* If ENTRUST, the dummy SP never be used. See ipsec_getpolicybysock. */ 143 .policy = IPSEC_POLICY_ENTRUST, 144 }; 145 146 static struct secpolicy *ipsec_checkpcbcache(struct mbuf *, 147 struct inpcbpolicy *, int); 148 static int ipsec_fillpcbcache(struct inpcbpolicy *, struct mbuf *, 149 struct secpolicy *, int); 150 static int ipsec_invalpcbcache(struct inpcbpolicy *, int); 151 152 /* 153 * Crypto support requirements: 154 * 155 * 1 require hardware support 156 * -1 require software support 157 * 0 take anything 158 */ 159 int crypto_support = 0; 160 161 static struct secpolicy *ipsec_getpolicybysock(struct mbuf *, u_int, 162 struct inpcb_hdr *, int *); 163 164 #ifdef INET6 165 int ip6_esp_trans_deflev = IPSEC_LEVEL_USE; 166 int ip6_esp_net_deflev = IPSEC_LEVEL_USE; 167 int ip6_ah_trans_deflev = IPSEC_LEVEL_USE; 168 int ip6_ah_net_deflev = IPSEC_LEVEL_USE; 169 struct secpolicy ip6_def_policy; 170 int ip6_ipsec_ecn = 0; /* ECN ignore(-1)/forbidden(0)/allowed(1) */ 171 #endif 172 173 static int ipsec_setspidx_inpcb(struct mbuf *, void *); 174 static int ipsec_setspidx(struct mbuf *, struct secpolicyindex *, int); 175 static void ipsec4_get_ulp(struct mbuf *m, struct secpolicyindex *, int); 176 static int ipsec4_setspidx_ipaddr(struct mbuf *, struct secpolicyindex *); 177 #ifdef INET6 178 static void ipsec6_get_ulp(struct mbuf *m, struct secpolicyindex *, int); 179 static int ipsec6_setspidx_ipaddr(struct mbuf *, struct secpolicyindex *); 180 #endif 181 static void ipsec_delpcbpolicy(struct inpcbpolicy *); 182 static void ipsec_destroy_policy(struct secpolicy *); 183 static int ipsec_sp_reject(const struct secpolicy *, const struct mbuf *); 184 static void vshiftl(unsigned char *, int, int); 185 static size_t ipsec_sp_hdrsiz(const struct secpolicy *, const struct mbuf *); 186 187 /* 188 * Try to validate and use cached policy on a PCB. 189 */ 190 static struct secpolicy * 191 ipsec_checkpcbcache(struct mbuf *m, struct inpcbpolicy *pcbsp, int dir) 192 { 193 struct secpolicyindex spidx; 194 struct secpolicy *sp = NULL; 195 int s; 196 197 KASSERT(IPSEC_DIR_IS_VALID(dir)); 198 KASSERT(pcbsp != NULL); 199 KASSERT(dir < __arraycount(pcbsp->sp_cache)); 200 KASSERT(inph_locked(pcbsp->sp_inph)); 201 202 /* 203 * Checking the generation and sp->state and taking a reference to an SP 204 * must be in a critical section of pserialize. See key_unlink_sp. 205 */ 206 s = pserialize_read_enter(); 207 /* SPD table change invalidate all the caches. */ 208 if (ipsec_spdgen != pcbsp->sp_cache[dir].cachegen) { 209 ipsec_invalpcbcache(pcbsp, dir); 210 goto out; 211 } 212 sp = pcbsp->sp_cache[dir].cachesp; 213 if (sp == NULL) 214 goto out; 215 if (sp->state != IPSEC_SPSTATE_ALIVE) { 216 sp = NULL; 217 ipsec_invalpcbcache(pcbsp, dir); 218 goto out; 219 } 220 if ((pcbsp->sp_cacheflags & IPSEC_PCBSP_CONNECTED) == 0) { 221 /* NB: assume ipsec_setspidx never sleep */ 222 if (ipsec_setspidx(m, &spidx, 1) != 0) { 223 sp = NULL; 224 goto out; 225 } 226 227 /* 228 * We have to make an exact match here since the cached rule 229 * might have lower priority than a rule that would otherwise 230 * have matched the packet. 231 */ 232 if (memcmp(&pcbsp->sp_cache[dir].cacheidx, &spidx, 233 sizeof(spidx))) { 234 sp = NULL; 235 goto out; 236 } 237 } else { 238 /* 239 * The pcb is connected, and the L4 code is sure that: 240 * - outgoing side uses inp_[lf]addr 241 * - incoming side looks up policy after inpcb lookup 242 * and address pair is know to be stable. We do not need 243 * to generate spidx again, nor check the address match again. 244 * 245 * For IPv4/v6 SOCK_STREAM sockets, this assumptions holds 246 * and there are calls to ipsec_pcbconn() from in_pcbconnect(). 247 */ 248 } 249 250 sp->lastused = time_second; 251 KEY_SP_REF(sp); 252 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_STAMP, 253 "DP cause refcnt++:%d SP:%p\n", 254 key_sp_refcnt(sp), pcbsp->sp_cache[dir].cachesp); 255 out: 256 pserialize_read_exit(s); 257 return sp; 258 } 259 260 static int 261 ipsec_fillpcbcache(struct inpcbpolicy *pcbsp, struct mbuf *m, 262 struct secpolicy *sp, int dir) 263 { 264 265 KASSERT(IPSEC_DIR_IS_INOROUT(dir)); 266 KASSERT(dir < __arraycount(pcbsp->sp_cache)); 267 KASSERT(inph_locked(pcbsp->sp_inph)); 268 269 pcbsp->sp_cache[dir].cachesp = NULL; 270 pcbsp->sp_cache[dir].cachehint = IPSEC_PCBHINT_UNKNOWN; 271 if (ipsec_setspidx(m, &pcbsp->sp_cache[dir].cacheidx, 1) != 0) { 272 return EINVAL; 273 } 274 pcbsp->sp_cache[dir].cachesp = sp; 275 if (pcbsp->sp_cache[dir].cachesp) { 276 /* 277 * If the PCB is connected, we can remember a hint to 278 * possibly short-circuit IPsec processing in other places. 279 */ 280 if (pcbsp->sp_cacheflags & IPSEC_PCBSP_CONNECTED) { 281 switch (pcbsp->sp_cache[dir].cachesp->policy) { 282 case IPSEC_POLICY_NONE: 283 case IPSEC_POLICY_BYPASS: 284 pcbsp->sp_cache[dir].cachehint = 285 IPSEC_PCBHINT_NO; 286 break; 287 default: 288 pcbsp->sp_cache[dir].cachehint = 289 IPSEC_PCBHINT_YES; 290 } 291 } 292 } 293 pcbsp->sp_cache[dir].cachegen = ipsec_spdgen; 294 295 return 0; 296 } 297 298 static int 299 ipsec_invalpcbcache(struct inpcbpolicy *pcbsp, int dir) 300 { 301 int i; 302 303 KASSERT(inph_locked(pcbsp->sp_inph)); 304 305 for (i = IPSEC_DIR_INBOUND; i <= IPSEC_DIR_OUTBOUND; i++) { 306 if (dir != IPSEC_DIR_ANY && i != dir) 307 continue; 308 pcbsp->sp_cache[i].cachesp = NULL; 309 pcbsp->sp_cache[i].cachehint = IPSEC_PCBHINT_UNKNOWN; 310 pcbsp->sp_cache[i].cachegen = 0; 311 memset(&pcbsp->sp_cache[i].cacheidx, 0, 312 sizeof(pcbsp->sp_cache[i].cacheidx)); 313 } 314 return 0; 315 } 316 317 void 318 ipsec_pcbconn(struct inpcbpolicy *pcbsp) 319 { 320 321 KASSERT(inph_locked(pcbsp->sp_inph)); 322 323 pcbsp->sp_cacheflags |= IPSEC_PCBSP_CONNECTED; 324 ipsec_invalpcbcache(pcbsp, IPSEC_DIR_ANY); 325 } 326 327 void 328 ipsec_pcbdisconn(struct inpcbpolicy *pcbsp) 329 { 330 331 KASSERT(inph_locked(pcbsp->sp_inph)); 332 333 pcbsp->sp_cacheflags &= ~IPSEC_PCBSP_CONNECTED; 334 ipsec_invalpcbcache(pcbsp, IPSEC_DIR_ANY); 335 } 336 337 void 338 ipsec_invalpcbcacheall(void) 339 { 340 341 if (ipsec_spdgen == UINT_MAX) 342 ipsec_spdgen = 1; 343 else 344 ipsec_spdgen++; 345 } 346 347 /* 348 * Return a held reference to the default SP. 349 */ 350 static struct secpolicy * 351 key_get_default_sp(int af, const char *where, int tag) 352 { 353 struct secpolicy *sp; 354 355 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_STAMP, "DP from %s:%u\n", where, tag); 356 357 switch(af) { 358 case AF_INET: 359 sp = &ip4_def_policy; 360 break; 361 #ifdef INET6 362 case AF_INET6: 363 sp = &ip6_def_policy; 364 break; 365 #endif 366 default: 367 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_STAMP, 368 "unexpected protocol family %u\n", af); 369 return NULL; 370 } 371 372 if (sp->policy != IPSEC_POLICY_DISCARD && 373 sp->policy != IPSEC_POLICY_NONE) { 374 IPSECLOG(LOG_INFO, "fixed system default policy: %d->%d\n", 375 sp->policy, IPSEC_POLICY_NONE); 376 sp->policy = IPSEC_POLICY_NONE; 377 } 378 KEY_SP_REF(sp); 379 380 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_STAMP, "DP returns SP:%p (%u)\n", 381 sp, key_sp_refcnt(sp)); 382 return sp; 383 } 384 385 #define KEY_GET_DEFAULT_SP(af) \ 386 key_get_default_sp((af), __func__, __LINE__) 387 388 /* 389 * For OUTBOUND packet having a socket. Searching SPD for packet, 390 * and return a pointer to SP. 391 * OUT: NULL: no appropriate SP found, the following value is set to error. 392 * 0 : bypass 393 * EACCES : discard packet. 394 * ENOENT : ipsec_acquire() in progress, maybe. 395 * others : error occurred. 396 * others: a pointer to SP 397 * 398 * NOTE: IPv6 mapped address concern is implemented here. 399 */ 400 static struct secpolicy * 401 ipsec_getpolicybysock(struct mbuf *m, u_int dir, struct inpcb_hdr *inph, 402 int *error) 403 { 404 struct inpcbpolicy *pcbsp = NULL; 405 struct secpolicy *currsp = NULL; /* policy on socket */ 406 struct secpolicy *sp; 407 int af; 408 409 KASSERT(m != NULL); 410 KASSERT(inph != NULL); 411 KASSERT(error != NULL); 412 KASSERTMSG(IPSEC_DIR_IS_INOROUT(dir), "invalid direction %u", dir); 413 414 KASSERT(inph->inph_socket != NULL); 415 KASSERT(inph_locked(inph)); 416 417 /* XXX FIXME inpcb/in6pcb vs socket*/ 418 af = inph->inph_af; 419 KASSERTMSG(af == AF_INET || af == AF_INET6, 420 "unexpected protocol family %u", af); 421 422 KASSERT(inph->inph_sp != NULL); 423 /* If we have a cached entry, and if it is still valid, use it. */ 424 IPSEC_STATINC(IPSEC_STAT_SPDCACHELOOKUP); 425 currsp = ipsec_checkpcbcache(m, inph->inph_sp, dir); 426 if (currsp) { 427 *error = 0; 428 return currsp; 429 } 430 IPSEC_STATINC(IPSEC_STAT_SPDCACHEMISS); 431 432 switch (af) { 433 case AF_INET: 434 #if defined(INET6) 435 case AF_INET6: 436 #endif 437 *error = ipsec_setspidx_inpcb(m, inph); 438 pcbsp = inph->inph_sp; 439 break; 440 default: 441 *error = EPFNOSUPPORT; 442 break; 443 } 444 if (*error) 445 return NULL; 446 447 KASSERT(pcbsp != NULL); 448 switch (dir) { 449 case IPSEC_DIR_INBOUND: 450 currsp = pcbsp->sp_in; 451 break; 452 case IPSEC_DIR_OUTBOUND: 453 currsp = pcbsp->sp_out; 454 break; 455 } 456 KASSERT(currsp != NULL); 457 458 if (pcbsp->priv) { /* when privileged socket */ 459 switch (currsp->policy) { 460 case IPSEC_POLICY_BYPASS: 461 case IPSEC_POLICY_IPSEC: 462 KEY_SP_REF(currsp); 463 sp = currsp; 464 break; 465 466 case IPSEC_POLICY_ENTRUST: 467 /* look for a policy in SPD */ 468 sp = KEY_LOOKUP_SP_BYSPIDX(&currsp->spidx, dir); 469 if (sp == NULL) /* no SP found */ 470 sp = KEY_GET_DEFAULT_SP(af); 471 break; 472 473 default: 474 IPSECLOG(LOG_ERR, "Invalid policy for PCB %d\n", 475 currsp->policy); 476 *error = EINVAL; 477 return NULL; 478 } 479 } else { /* unpriv, SPD has policy */ 480 sp = KEY_LOOKUP_SP_BYSPIDX(&currsp->spidx, dir); 481 if (sp == NULL) { /* no SP found */ 482 switch (currsp->policy) { 483 case IPSEC_POLICY_BYPASS: 484 IPSECLOG(LOG_ERR, "Illegal policy for " 485 "non-priviliged defined %d\n", 486 currsp->policy); 487 *error = EINVAL; 488 return NULL; 489 490 case IPSEC_POLICY_ENTRUST: 491 sp = KEY_GET_DEFAULT_SP(af); 492 break; 493 494 case IPSEC_POLICY_IPSEC: 495 KEY_SP_REF(currsp); 496 sp = currsp; 497 break; 498 499 default: 500 IPSECLOG(LOG_ERR, "Invalid policy for " 501 "PCB %d\n", currsp->policy); 502 *error = EINVAL; 503 return NULL; 504 } 505 } 506 } 507 KASSERTMSG(sp != NULL, "null SP (priv %u policy %u", pcbsp->priv, 508 currsp->policy); 509 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_STAMP, 510 "DP (priv %u policy %u) allocates SP:%p (refcnt %u)\n", 511 pcbsp->priv, currsp->policy, sp, key_sp_refcnt(sp)); 512 ipsec_fillpcbcache(pcbsp, m, sp, dir); 513 return sp; 514 } 515 516 /* 517 * For FORWARDING packet or OUTBOUND without a socket. Searching SPD for packet, 518 * and return a pointer to SP. 519 * OUT: positive: a pointer to the entry for security policy leaf matched. 520 * NULL: no appropriate SP found, the following value is set to error. 521 * 0 : bypass 522 * EACCES : discard packet. 523 * ENOENT : ipsec_acquire() in progress, maybe. 524 * others : error occurred. 525 */ 526 static struct secpolicy * 527 ipsec_getpolicybyaddr(struct mbuf *m, u_int dir, int flag, int *error) 528 { 529 struct secpolicyindex spidx; 530 struct secpolicy *sp; 531 532 KASSERT(m != NULL); 533 KASSERT(error != NULL); 534 KASSERTMSG(IPSEC_DIR_IS_INOROUT(dir), "invalid direction %u", dir); 535 536 sp = NULL; 537 538 /* Make an index to look for a policy. */ 539 *error = ipsec_setspidx(m, &spidx, (flag & IP_FORWARDING) ? 0 : 1); 540 if (*error != 0) { 541 IPSECLOG(LOG_DEBUG, "setpidx failed, dir %u flag %u\n", dir, flag); 542 memset(&spidx, 0, sizeof(spidx)); 543 return NULL; 544 } 545 546 spidx.dir = dir; 547 548 if (key_havesp(dir)) { 549 sp = KEY_LOOKUP_SP_BYSPIDX(&spidx, dir); 550 } 551 if (sp == NULL) { 552 /* no SP found, use system default */ 553 sp = KEY_GET_DEFAULT_SP(spidx.dst.sa.sa_family); 554 } 555 556 KASSERT(sp != NULL); 557 return sp; 558 } 559 560 static struct secpolicy * 561 ipsec_checkpolicy(struct mbuf *m, u_int dir, u_int flag, int *error, 562 void *inp) 563 { 564 struct secpolicy *sp; 565 566 *error = 0; 567 568 if (inp == NULL) { 569 sp = ipsec_getpolicybyaddr(m, dir, flag, error); 570 } else { 571 struct inpcb_hdr *inph = (struct inpcb_hdr *)inp; 572 KASSERT(inph->inph_socket != NULL); 573 sp = ipsec_getpolicybysock(m, dir, inph, error); 574 } 575 if (sp == NULL) { 576 KASSERTMSG(*error != 0, "getpolicy failed w/o error"); 577 IPSEC_STATINC(IPSEC_STAT_OUT_INVAL); 578 return NULL; 579 } 580 KASSERTMSG(*error == 0, "sp w/ error set to %u", *error); 581 582 switch (sp->policy) { 583 case IPSEC_POLICY_ENTRUST: 584 default: 585 printf("%s: invalid policy %u\n", __func__, sp->policy); 586 /* fall thru... */ 587 case IPSEC_POLICY_DISCARD: 588 IPSEC_STATINC(IPSEC_STAT_OUT_POLVIO); 589 *error = -EINVAL; /* packet is discarded by caller */ 590 break; 591 case IPSEC_POLICY_BYPASS: 592 case IPSEC_POLICY_NONE: 593 KEY_SP_UNREF(&sp); 594 sp = NULL; /* NB: force NULL result */ 595 break; 596 case IPSEC_POLICY_IPSEC: 597 KASSERT(sp->req != NULL); 598 break; 599 } 600 601 if (*error != 0) { 602 KEY_SP_UNREF(&sp); 603 sp = NULL; 604 IPSECLOG(LOG_DEBUG, "done, error %d\n", *error); 605 } 606 607 return sp; 608 } 609 610 int 611 ipsec4_output(struct mbuf *m, struct inpcb *inp, int flags, 612 u_long *mtu, bool *natt_frag, bool *done) 613 { 614 struct secpolicy *sp = NULL; 615 u_long _mtu = 0; 616 int error, s; 617 618 /* 619 * Check the security policy (SP) for the packet and, if required, 620 * do IPsec-related processing. There are two cases here; the first 621 * time a packet is sent through it will be untagged and handled by 622 * ipsec_checkpolicy(). If the packet is resubmitted to ip_output 623 * (e.g. after AH, ESP, etc. processing), there will be a tag to 624 * bypass the lookup and related policy checking. 625 */ 626 if (ipsec_outdone(m)) { 627 return 0; 628 } 629 s = splsoftnet(); 630 if (inp && ipsec_pcb_skip_ipsec(inp->inp_sp, IPSEC_DIR_OUTBOUND)) { 631 splx(s); 632 return 0; 633 } 634 sp = ipsec_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags, &error, inp); 635 636 /* 637 * There are four return cases: 638 * sp != NULL apply IPsec policy 639 * sp == NULL, error == 0 no IPsec handling needed 640 * sp == NULL, error == -EINVAL discard packet w/o error 641 * sp == NULL, error != 0 discard packet, report error 642 */ 643 if (sp == NULL) { 644 splx(s); 645 if (error) { 646 /* 647 * Hack: -EINVAL is used to signal that a packet 648 * should be silently discarded. This is typically 649 * because we asked key management for an SA and 650 * it was delayed (e.g. kicked up to IKE). 651 */ 652 if (error == -EINVAL) 653 error = 0; 654 m_freem(m); 655 *done = true; 656 return error; 657 } 658 /* No IPsec processing for this packet. */ 659 return 0; 660 } 661 662 /* 663 * Do delayed checksums now because we send before 664 * this is done in the normal processing path. 665 */ 666 if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 667 in_delayed_cksum(m); 668 m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 669 } 670 671 error = ipsec4_process_packet(m, sp->req, &_mtu); 672 if (error == 0 && _mtu != 0) { 673 /* 674 * NAT-T ESP fragmentation: do not do IPSec processing 675 * now, we will do it on each fragmented packet. 676 */ 677 *mtu = _mtu; 678 *natt_frag = true; 679 KEY_SP_UNREF(&sp); 680 splx(s); 681 return 0; 682 } 683 684 /* 685 * Preserve KAME behaviour: ENOENT can be returned 686 * when an SA acquire is in progress. Don't propagate 687 * this to user-level; it confuses applications. 688 * 689 * XXX this will go away when the SADB is redone. 690 */ 691 if (error == ENOENT) 692 error = 0; 693 KEY_SP_UNREF(&sp); 694 splx(s); 695 *done = true; 696 return error; 697 } 698 699 int 700 ipsec4_input(struct mbuf *m, int flags) 701 { 702 struct secpolicy *sp; 703 int error, s; 704 705 s = splsoftnet(); 706 error = ipsec_in_reject(m, NULL); 707 splx(s); 708 if (error) { 709 return EINVAL; 710 } 711 712 if (flags == 0) { 713 /* We are done. */ 714 return 0; 715 } 716 717 /* 718 * Peek at the outbound SP for this packet to determine if 719 * it is a Fast Forward candidate. 720 */ 721 s = splsoftnet(); 722 sp = ipsec_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags, &error, NULL); 723 if (sp != NULL) { 724 m->m_flags &= ~M_CANFASTFWD; 725 KEY_SP_UNREF(&sp); 726 } 727 splx(s); 728 return 0; 729 } 730 731 /* 732 * If the packet is routed over IPsec tunnel, tell the originator the 733 * tunnel MTU. 734 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz 735 * 736 * XXX: Quick hack!!! 737 * 738 * XXX: And what if the MTU goes negative? 739 */ 740 int 741 ipsec4_forward(struct mbuf *m, int *destmtu) 742 { 743 struct secpolicy *sp; 744 size_t ipsechdr; 745 int error; 746 747 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, IP_FORWARDING, 748 &error); 749 if (sp == NULL) { 750 return EINVAL; 751 } 752 753 /* Count IPsec header size. */ 754 ipsechdr = ipsec_sp_hdrsiz(sp, m); 755 756 /* 757 * Find the correct route for outer IPv4 header, compute tunnel MTU. 758 */ 759 if (sp->req) { 760 struct secasvar *sav; 761 762 sav = ipsec_lookup_sa(sp->req, m); 763 if (sav != NULL) { 764 struct route *ro; 765 struct rtentry *rt; 766 767 ro = &sav->sah->sa_route; 768 rt = rtcache_validate(ro); 769 if (rt && rt->rt_ifp) { 770 *destmtu = rt->rt_rmx.rmx_mtu ? 771 rt->rt_rmx.rmx_mtu : rt->rt_ifp->if_mtu; 772 *destmtu -= ipsechdr; 773 } 774 rtcache_unref(rt, ro); 775 KEY_SA_UNREF(&sav); 776 } 777 } 778 KEY_SP_UNREF(&sp); 779 return 0; 780 } 781 782 static int 783 ipsec_setspidx_inpcb(struct mbuf *m, void *pcb) 784 { 785 struct inpcb_hdr *inph = (struct inpcb_hdr *)pcb; 786 int error; 787 788 KASSERT(inph != NULL); 789 KASSERT(inph->inph_sp != NULL); 790 KASSERT(inph->inph_sp->sp_out != NULL); 791 KASSERT(inph->inph_sp->sp_in != NULL); 792 793 error = ipsec_setspidx(m, &inph->inph_sp->sp_in->spidx, 1); 794 if (error == 0) { 795 inph->inph_sp->sp_in->spidx.dir = IPSEC_DIR_INBOUND; 796 inph->inph_sp->sp_out->spidx = inph->inph_sp->sp_in->spidx; 797 inph->inph_sp->sp_out->spidx.dir = IPSEC_DIR_OUTBOUND; 798 } else { 799 memset(&inph->inph_sp->sp_in->spidx, 0, 800 sizeof(inph->inph_sp->sp_in->spidx)); 801 memset(&inph->inph_sp->sp_out->spidx, 0, 802 sizeof(inph->inph_sp->sp_out->spidx)); 803 } 804 return error; 805 } 806 807 /* 808 * configure security policy index (src/dst/proto/sport/dport) 809 * by looking at the content of mbuf. 810 * the caller is responsible for error recovery (like clearing up spidx). 811 */ 812 static int 813 ipsec_setspidx(struct mbuf *m, struct secpolicyindex *spidx, int needport) 814 { 815 struct ip *ip = NULL; 816 struct ip ipbuf; 817 u_int v; 818 struct mbuf *n; 819 int len; 820 int error; 821 822 KASSERT(m != NULL); 823 824 /* 825 * validate m->m_pkthdr.len. we see incorrect length if we 826 * mistakenly call this function with inconsistent mbuf chain 827 * (like 4.4BSD tcp/udp processing). 828 * 829 * XXX XXX XXX: We should remove this. 830 */ 831 len = 0; 832 for (n = m; n; n = n->m_next) 833 len += n->m_len; 834 if (m->m_pkthdr.len != len) { 835 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 836 "total of m_len(%d) != pkthdr.len(%d), ignored.\n", 837 len, m->m_pkthdr.len); 838 KASSERTMSG(0, "impossible"); 839 return EINVAL; 840 } 841 842 if (m->m_pkthdr.len < sizeof(struct ip)) { 843 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 844 "pkthdr.len(%d) < sizeof(struct ip), ignored.\n", 845 m->m_pkthdr.len); 846 return EINVAL; 847 } 848 849 if (m->m_len >= sizeof(*ip)) { 850 ip = mtod(m, struct ip *); 851 } else { 852 m_copydata(m, 0, sizeof(ipbuf), &ipbuf); 853 ip = &ipbuf; 854 } 855 v = ip->ip_v; 856 switch (v) { 857 case 4: 858 error = ipsec4_setspidx_ipaddr(m, spidx); 859 if (error) 860 return error; 861 ipsec4_get_ulp(m, spidx, needport); 862 return 0; 863 #ifdef INET6 864 case 6: 865 if (m->m_pkthdr.len < sizeof(struct ip6_hdr)) { 866 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 867 "pkthdr.len(%d) < sizeof(struct ip6_hdr), " 868 "ignored.\n", m->m_pkthdr.len); 869 return EINVAL; 870 } 871 error = ipsec6_setspidx_ipaddr(m, spidx); 872 if (error) 873 return error; 874 ipsec6_get_ulp(m, spidx, needport); 875 return 0; 876 #endif 877 default: 878 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 879 "unknown IP version %u, ignored.\n", v); 880 return EINVAL; 881 } 882 } 883 884 static void 885 ipsec4_get_ulp(struct mbuf *m, struct secpolicyindex *spidx, int needport) 886 { 887 u_int8_t nxt; 888 int off; 889 890 KASSERT(m != NULL); 891 KASSERTMSG(m->m_pkthdr.len >= sizeof(struct ip), "packet too short"); 892 893 /* NB: ip_input() flips it into host endian XXX need more checking */ 894 if (m->m_len >= sizeof(struct ip)) { 895 struct ip *ip = mtod(m, struct ip *); 896 if (ip->ip_off & htons(IP_MF | IP_OFFMASK)) 897 goto done; 898 off = ip->ip_hl << 2; 899 nxt = ip->ip_p; 900 } else { 901 struct ip ih; 902 903 m_copydata(m, 0, sizeof(struct ip), &ih); 904 if (ih.ip_off & htons(IP_MF | IP_OFFMASK)) 905 goto done; 906 off = ih.ip_hl << 2; 907 nxt = ih.ip_p; 908 } 909 910 while (off < m->m_pkthdr.len) { 911 struct ip6_ext ip6e; 912 struct tcphdr th; 913 struct udphdr uh; 914 struct icmp icmph; 915 916 switch (nxt) { 917 case IPPROTO_TCP: 918 spidx->ul_proto = nxt; 919 if (!needport) 920 goto done_proto; 921 if (off + sizeof(struct tcphdr) > m->m_pkthdr.len) 922 goto done; 923 m_copydata(m, off, sizeof(th), &th); 924 spidx->src.sin.sin_port = th.th_sport; 925 spidx->dst.sin.sin_port = th.th_dport; 926 return; 927 case IPPROTO_UDP: 928 spidx->ul_proto = nxt; 929 if (!needport) 930 goto done_proto; 931 if (off + sizeof(struct udphdr) > m->m_pkthdr.len) 932 goto done; 933 m_copydata(m, off, sizeof(uh), &uh); 934 spidx->src.sin.sin_port = uh.uh_sport; 935 spidx->dst.sin.sin_port = uh.uh_dport; 936 return; 937 case IPPROTO_AH: 938 if (off + sizeof(ip6e) > m->m_pkthdr.len) 939 goto done; 940 /* XXX sigh, this works but is totally bogus */ 941 m_copydata(m, off, sizeof(ip6e), &ip6e); 942 off += (ip6e.ip6e_len + 2) << 2; 943 nxt = ip6e.ip6e_nxt; 944 break; 945 case IPPROTO_ICMP: 946 spidx->ul_proto = nxt; 947 if (off + sizeof(struct icmp) > m->m_pkthdr.len) 948 goto done; 949 m_copydata(m, off, sizeof(icmph), &icmph); 950 ((struct sockaddr_in *)&spidx->src)->sin_port = 951 htons((uint16_t)icmph.icmp_type); 952 ((struct sockaddr_in *)&spidx->dst)->sin_port = 953 htons((uint16_t)icmph.icmp_code); 954 return; 955 default: 956 /* XXX intermediate headers??? */ 957 spidx->ul_proto = nxt; 958 goto done_proto; 959 } 960 } 961 done: 962 spidx->ul_proto = IPSEC_ULPROTO_ANY; 963 done_proto: 964 spidx->src.sin.sin_port = IPSEC_PORT_ANY; 965 spidx->dst.sin.sin_port = IPSEC_PORT_ANY; 966 } 967 968 static int 969 ipsec4_setspidx_ipaddr(struct mbuf *m, struct secpolicyindex *spidx) 970 { 971 static const struct sockaddr_in template = { 972 sizeof(struct sockaddr_in), 973 AF_INET, 974 0, { 0 }, { 0, 0, 0, 0, 0, 0, 0, 0 } 975 }; 976 977 spidx->src.sin = template; 978 spidx->dst.sin = template; 979 980 if (m->m_len < sizeof(struct ip)) { 981 m_copydata(m, offsetof(struct ip, ip_src), 982 sizeof(struct in_addr), &spidx->src.sin.sin_addr); 983 m_copydata(m, offsetof(struct ip, ip_dst), 984 sizeof(struct in_addr), &spidx->dst.sin.sin_addr); 985 } else { 986 struct ip *ip = mtod(m, struct ip *); 987 spidx->src.sin.sin_addr = ip->ip_src; 988 spidx->dst.sin.sin_addr = ip->ip_dst; 989 } 990 991 spidx->prefs = sizeof(struct in_addr) << 3; 992 spidx->prefd = sizeof(struct in_addr) << 3; 993 994 return 0; 995 } 996 997 #ifdef INET6 998 static void 999 ipsec6_get_ulp(struct mbuf *m, struct secpolicyindex *spidx, int needport) 1000 { 1001 int off, nxt; 1002 struct tcphdr th; 1003 struct udphdr uh; 1004 struct icmp6_hdr icmph; 1005 1006 KASSERT(m != NULL); 1007 1008 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DUMP)) { 1009 kdebug_mbuf(__func__, m); 1010 } 1011 1012 /* set default */ 1013 spidx->ul_proto = IPSEC_ULPROTO_ANY; 1014 ((struct sockaddr_in6 *)&spidx->src)->sin6_port = IPSEC_PORT_ANY; 1015 ((struct sockaddr_in6 *)&spidx->dst)->sin6_port = IPSEC_PORT_ANY; 1016 1017 nxt = -1; 1018 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt); 1019 if (off < 0 || m->m_pkthdr.len < off) 1020 return; 1021 1022 switch (nxt) { 1023 case IPPROTO_TCP: 1024 spidx->ul_proto = nxt; 1025 if (!needport) 1026 break; 1027 if (off + sizeof(struct tcphdr) > m->m_pkthdr.len) 1028 break; 1029 m_copydata(m, off, sizeof(th), &th); 1030 ((struct sockaddr_in6 *)&spidx->src)->sin6_port = th.th_sport; 1031 ((struct sockaddr_in6 *)&spidx->dst)->sin6_port = th.th_dport; 1032 break; 1033 case IPPROTO_UDP: 1034 spidx->ul_proto = nxt; 1035 if (!needport) 1036 break; 1037 if (off + sizeof(struct udphdr) > m->m_pkthdr.len) 1038 break; 1039 m_copydata(m, off, sizeof(uh), &uh); 1040 ((struct sockaddr_in6 *)&spidx->src)->sin6_port = uh.uh_sport; 1041 ((struct sockaddr_in6 *)&spidx->dst)->sin6_port = uh.uh_dport; 1042 break; 1043 case IPPROTO_ICMPV6: 1044 spidx->ul_proto = nxt; 1045 if (off + sizeof(struct icmp6_hdr) > m->m_pkthdr.len) 1046 break; 1047 m_copydata(m, off, sizeof(icmph), &icmph); 1048 ((struct sockaddr_in6 *)&spidx->src)->sin6_port = 1049 htons((uint16_t)icmph.icmp6_type); 1050 ((struct sockaddr_in6 *)&spidx->dst)->sin6_port = 1051 htons((uint16_t)icmph.icmp6_code); 1052 break; 1053 default: 1054 /* XXX intermediate headers??? */ 1055 spidx->ul_proto = nxt; 1056 break; 1057 } 1058 } 1059 1060 static int 1061 ipsec6_setspidx_ipaddr(struct mbuf *m, struct secpolicyindex *spidx) 1062 { 1063 struct ip6_hdr *ip6 = NULL; 1064 struct ip6_hdr ip6buf; 1065 struct sockaddr_in6 *sin6; 1066 1067 if (m->m_len >= sizeof(*ip6)) { 1068 ip6 = mtod(m, struct ip6_hdr *); 1069 } else { 1070 m_copydata(m, 0, sizeof(ip6buf), &ip6buf); 1071 ip6 = &ip6buf; 1072 } 1073 1074 sin6 = (struct sockaddr_in6 *)&spidx->src; 1075 memset(sin6, 0, sizeof(*sin6)); 1076 sin6->sin6_family = AF_INET6; 1077 sin6->sin6_len = sizeof(struct sockaddr_in6); 1078 memcpy(&sin6->sin6_addr, &ip6->ip6_src, sizeof(ip6->ip6_src)); 1079 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) { 1080 sin6->sin6_addr.s6_addr16[1] = 0; 1081 sin6->sin6_scope_id = ntohs(ip6->ip6_src.s6_addr16[1]); 1082 } 1083 spidx->prefs = sizeof(struct in6_addr) << 3; 1084 1085 sin6 = (struct sockaddr_in6 *)&spidx->dst; 1086 memset(sin6, 0, sizeof(*sin6)); 1087 sin6->sin6_family = AF_INET6; 1088 sin6->sin6_len = sizeof(struct sockaddr_in6); 1089 memcpy(&sin6->sin6_addr, &ip6->ip6_dst, sizeof(ip6->ip6_dst)); 1090 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) { 1091 sin6->sin6_addr.s6_addr16[1] = 0; 1092 sin6->sin6_scope_id = ntohs(ip6->ip6_dst.s6_addr16[1]); 1093 } 1094 spidx->prefd = sizeof(struct in6_addr) << 3; 1095 1096 return 0; 1097 } 1098 #endif 1099 1100 static void 1101 ipsec_delpcbpolicy(struct inpcbpolicy *p) 1102 { 1103 1104 kmem_intr_free(p, sizeof(*p)); 1105 } 1106 1107 int 1108 ipsec_init_pcbpolicy(struct socket *so, struct inpcbpolicy **policy) 1109 { 1110 struct inpcbpolicy *new; 1111 1112 KASSERT(so != NULL); 1113 KASSERT(policy != NULL); 1114 1115 new = kmem_intr_zalloc(sizeof(*new), KM_NOSLEEP); 1116 if (new == NULL) { 1117 IPSECLOG(LOG_DEBUG, "No more memory.\n"); 1118 return ENOBUFS; 1119 } 1120 1121 if (IPSEC_PRIVILEGED_SO(so)) 1122 new->priv = 1; 1123 else 1124 new->priv = 0; 1125 1126 /* 1127 * Set dummy SPs. Actual SPs will be allocated later if needed. 1128 */ 1129 new->sp_in = &ipsec_dummy_sp; 1130 new->sp_out = &ipsec_dummy_sp; 1131 1132 *policy = new; 1133 1134 return 0; 1135 } 1136 1137 static void 1138 ipsec_destroy_policy(struct secpolicy *sp) 1139 { 1140 1141 if (sp == &ipsec_dummy_sp) { 1142 ; /* It's dummy. No need to free it. */ 1143 } else { 1144 /* 1145 * We cannot destroy here because it can be called in 1146 * softint. So mark the SP as DEAD and let the timer 1147 * destroy it. See key_timehandler_spd. 1148 */ 1149 sp->state = IPSEC_SPSTATE_DEAD; 1150 } 1151 } 1152 1153 int 1154 ipsec_set_policy(void *inp, int optname, const void *request, size_t len, 1155 kauth_cred_t cred) 1156 { 1157 struct inpcb_hdr *inph = (struct inpcb_hdr *)inp; 1158 const struct sadb_x_policy *xpl; 1159 struct secpolicy *newsp, *oldsp; 1160 struct secpolicy **policy; 1161 int error; 1162 1163 KASSERT(!cpu_softintr_p()); 1164 KASSERT(inph != NULL); 1165 KASSERT(inph_locked(inph)); 1166 KASSERT(request != NULL); 1167 1168 if (len < sizeof(*xpl)) 1169 return EINVAL; 1170 xpl = (const struct sadb_x_policy *)request; 1171 1172 KASSERT(inph->inph_sp != NULL); 1173 1174 /* select direction */ 1175 switch (xpl->sadb_x_policy_dir) { 1176 case IPSEC_DIR_INBOUND: 1177 policy = &inph->inph_sp->sp_in; 1178 break; 1179 case IPSEC_DIR_OUTBOUND: 1180 policy = &inph->inph_sp->sp_out; 1181 break; 1182 default: 1183 IPSECLOG(LOG_ERR, "invalid direction=%u\n", 1184 xpl->sadb_x_policy_dir); 1185 return EINVAL; 1186 } 1187 1188 /* sanity check. */ 1189 if (policy == NULL || *policy == NULL) 1190 return EINVAL; 1191 1192 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DUMP)) { 1193 kdebug_sadb_xpolicy("set passed policy", request); 1194 } 1195 1196 /* check policy type */ 1197 /* ipsec_set_policy() accepts IPSEC, ENTRUST and BYPASS. */ 1198 if (xpl->sadb_x_policy_type == IPSEC_POLICY_DISCARD || 1199 xpl->sadb_x_policy_type == IPSEC_POLICY_NONE) 1200 return EINVAL; 1201 1202 /* check privileged socket */ 1203 if (xpl->sadb_x_policy_type == IPSEC_POLICY_BYPASS) { 1204 error = kauth_authorize_network(cred, KAUTH_NETWORK_IPSEC, 1205 KAUTH_REQ_NETWORK_IPSEC_BYPASS, NULL, NULL, NULL); 1206 if (error) 1207 return error; 1208 } 1209 1210 /* allocation new SP entry */ 1211 if ((newsp = key_msg2sp(xpl, len, &error)) == NULL) 1212 return error; 1213 1214 key_init_sp(newsp); 1215 newsp->created = time_uptime; 1216 /* Insert the global list for SPs for sockets */ 1217 key_socksplist_add(newsp); 1218 1219 /* clear old SP and set new SP */ 1220 oldsp = *policy; 1221 *policy = newsp; 1222 ipsec_destroy_policy(oldsp); 1223 1224 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DUMP)) { 1225 printf("%s: new policy\n", __func__); 1226 kdebug_secpolicy(newsp); 1227 } 1228 1229 return 0; 1230 } 1231 1232 int 1233 ipsec_get_policy(void *inp, const void *request, size_t len, 1234 struct mbuf **mp) 1235 { 1236 struct inpcb_hdr *inph = (struct inpcb_hdr *)inp; 1237 const struct sadb_x_policy *xpl; 1238 struct secpolicy *policy; 1239 1240 /* sanity check. */ 1241 if (inph == NULL || request == NULL || mp == NULL) 1242 return EINVAL; 1243 KASSERT(inph->inph_sp != NULL); 1244 if (len < sizeof(*xpl)) 1245 return EINVAL; 1246 xpl = (const struct sadb_x_policy *)request; 1247 1248 /* select direction */ 1249 switch (xpl->sadb_x_policy_dir) { 1250 case IPSEC_DIR_INBOUND: 1251 policy = inph->inph_sp->sp_in; 1252 break; 1253 case IPSEC_DIR_OUTBOUND: 1254 policy = inph->inph_sp->sp_out; 1255 break; 1256 default: 1257 IPSECLOG(LOG_ERR, "invalid direction=%u\n", 1258 xpl->sadb_x_policy_dir); 1259 return EINVAL; 1260 } 1261 1262 if (policy == NULL) 1263 return EINVAL; 1264 1265 *mp = key_sp2msg(policy, M_NOWAIT); 1266 if (!*mp) { 1267 IPSECLOG(LOG_DEBUG, "No more memory.\n"); 1268 return ENOBUFS; 1269 } 1270 1271 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DUMP)) { 1272 kdebug_mbuf(__func__, *mp); 1273 } 1274 1275 return 0; 1276 } 1277 1278 int 1279 ipsec_delete_pcbpolicy(void *inp) 1280 { 1281 struct inpcb_hdr *inph = (struct inpcb_hdr *)inp; 1282 1283 KASSERT(inph != NULL); 1284 1285 if (inph->inph_sp == NULL) 1286 return 0; 1287 1288 if (inph->inph_sp->sp_in != NULL) 1289 ipsec_destroy_policy(inph->inph_sp->sp_in); 1290 1291 if (inph->inph_sp->sp_out != NULL) 1292 ipsec_destroy_policy(inph->inph_sp->sp_out); 1293 1294 ipsec_invalpcbcache(inph->inph_sp, IPSEC_DIR_ANY); 1295 1296 ipsec_delpcbpolicy(inph->inph_sp); 1297 inph->inph_sp = NULL; 1298 1299 return 0; 1300 } 1301 1302 /* 1303 * Return the current level (either IPSEC_LEVEL_USE or IPSEC_LEVEL_REQUIRE). 1304 */ 1305 u_int 1306 ipsec_get_reqlevel(const struct ipsecrequest *isr) 1307 { 1308 u_int level = 0; 1309 u_int esp_trans_deflev, esp_net_deflev; 1310 u_int ah_trans_deflev, ah_net_deflev; 1311 1312 KASSERT(isr != NULL); 1313 KASSERT(isr->sp != NULL); 1314 KASSERTMSG( 1315 isr->sp->spidx.src.sa.sa_family == isr->sp->spidx.dst.sa.sa_family, 1316 "af family mismatch, src %u, dst %u", 1317 isr->sp->spidx.src.sa.sa_family, isr->sp->spidx.dst.sa.sa_family); 1318 1319 /* XXX note that we have ipseclog() expanded here - code sync issue */ 1320 #define IPSEC_CHECK_DEFAULT(lev) \ 1321 (((lev) != IPSEC_LEVEL_USE && (lev) != IPSEC_LEVEL_REQUIRE \ 1322 && (lev) != IPSEC_LEVEL_UNIQUE) ? \ 1323 (ipsec_debug ? log(LOG_INFO, "fixed system default level " #lev \ 1324 ":%d->%d\n", (lev), IPSEC_LEVEL_REQUIRE) : (void)0), \ 1325 (lev) = IPSEC_LEVEL_REQUIRE, (lev) \ 1326 : (lev)) 1327 1328 /* set default level */ 1329 switch (((struct sockaddr *)&isr->sp->spidx.src)->sa_family) { 1330 #ifdef INET 1331 case AF_INET: 1332 esp_trans_deflev = IPSEC_CHECK_DEFAULT(ip4_esp_trans_deflev); 1333 esp_net_deflev = IPSEC_CHECK_DEFAULT(ip4_esp_net_deflev); 1334 ah_trans_deflev = IPSEC_CHECK_DEFAULT(ip4_ah_trans_deflev); 1335 ah_net_deflev = IPSEC_CHECK_DEFAULT(ip4_ah_net_deflev); 1336 break; 1337 #endif 1338 #ifdef INET6 1339 case AF_INET6: 1340 esp_trans_deflev = IPSEC_CHECK_DEFAULT(ip6_esp_trans_deflev); 1341 esp_net_deflev = IPSEC_CHECK_DEFAULT(ip6_esp_net_deflev); 1342 ah_trans_deflev = IPSEC_CHECK_DEFAULT(ip6_ah_trans_deflev); 1343 ah_net_deflev = IPSEC_CHECK_DEFAULT(ip6_ah_net_deflev); 1344 break; 1345 #endif 1346 default: 1347 panic("%s: unknown af %u", __func__, 1348 isr->sp->spidx.src.sa.sa_family); 1349 } 1350 1351 #undef IPSEC_CHECK_DEFAULT 1352 1353 /* set level */ 1354 switch (isr->level) { 1355 case IPSEC_LEVEL_DEFAULT: 1356 switch (isr->saidx.proto) { 1357 case IPPROTO_ESP: 1358 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) 1359 level = esp_net_deflev; 1360 else 1361 level = esp_trans_deflev; 1362 break; 1363 case IPPROTO_AH: 1364 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) 1365 level = ah_net_deflev; 1366 else 1367 level = ah_trans_deflev; 1368 break; 1369 case IPPROTO_IPCOMP: 1370 /* 1371 * we don't really care, as IPcomp document says that 1372 * we shouldn't compress small packets 1373 */ 1374 level = IPSEC_LEVEL_USE; 1375 break; 1376 default: 1377 panic("%s: Illegal protocol defined %u", __func__, 1378 isr->saidx.proto); 1379 } 1380 break; 1381 1382 case IPSEC_LEVEL_USE: 1383 case IPSEC_LEVEL_REQUIRE: 1384 level = isr->level; 1385 break; 1386 case IPSEC_LEVEL_UNIQUE: 1387 level = IPSEC_LEVEL_REQUIRE; 1388 break; 1389 1390 default: 1391 panic("%s: Illegal IPsec level %u", __func__, isr->level); 1392 } 1393 1394 return level; 1395 } 1396 1397 /* 1398 * Check security policy requirements against the actual packet contents. 1399 * 1400 * If the SP requires an IPsec packet, and the packet was neither AH nor ESP, 1401 * then kick it. 1402 */ 1403 static int 1404 ipsec_sp_reject(const struct secpolicy *sp, const struct mbuf *m) 1405 { 1406 struct ipsecrequest *isr; 1407 1408 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DATA)) { 1409 printf("%s: using SP\n", __func__); 1410 kdebug_secpolicy(sp); 1411 } 1412 1413 /* check policy */ 1414 switch (sp->policy) { 1415 case IPSEC_POLICY_DISCARD: 1416 return 1; 1417 case IPSEC_POLICY_BYPASS: 1418 case IPSEC_POLICY_NONE: 1419 return 0; 1420 } 1421 1422 KASSERTMSG(sp->policy == IPSEC_POLICY_IPSEC, 1423 "invalid policy %u", sp->policy); 1424 1425 /* XXX should compare policy against ipsec header history */ 1426 1427 for (isr = sp->req; isr != NULL; isr = isr->next) { 1428 if (ipsec_get_reqlevel(isr) != IPSEC_LEVEL_REQUIRE) 1429 continue; 1430 switch (isr->saidx.proto) { 1431 case IPPROTO_ESP: 1432 if ((m->m_flags & M_DECRYPTED) == 0) { 1433 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 1434 "ESP m_flags:%x\n", m->m_flags); 1435 return 1; 1436 } 1437 break; 1438 case IPPROTO_AH: 1439 if ((m->m_flags & M_AUTHIPHDR) == 0) { 1440 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 1441 "AH m_flags:%x\n", m->m_flags); 1442 return 1; 1443 } 1444 break; 1445 case IPPROTO_IPCOMP: 1446 /* 1447 * We don't really care, as IPcomp document 1448 * says that we shouldn't compress small 1449 * packets, IPComp policy should always be 1450 * treated as being in "use" level. 1451 */ 1452 break; 1453 } 1454 } 1455 1456 return 0; 1457 } 1458 1459 /* 1460 * Check security policy requirements. 1461 */ 1462 int 1463 ipsec_in_reject(struct mbuf *m, void *inp) 1464 { 1465 struct inpcb_hdr *inph = (struct inpcb_hdr *)inp; 1466 struct secpolicy *sp; 1467 int error; 1468 int result; 1469 1470 KASSERT(m != NULL); 1471 1472 if (inph == NULL) 1473 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND, 1474 IP_FORWARDING, &error); 1475 else 1476 sp = ipsec_getpolicybysock(m, IPSEC_DIR_INBOUND, 1477 inph, &error); 1478 1479 if (sp != NULL) { 1480 result = ipsec_sp_reject(sp, m); 1481 if (result) 1482 IPSEC_STATINC(IPSEC_STAT_IN_POLVIO); 1483 KEY_SP_UNREF(&sp); 1484 } else { 1485 result = 0; 1486 } 1487 return result; 1488 } 1489 1490 /* 1491 * Compute the byte size to be occupied by the IPsec header. If it is 1492 * tunneled, it includes the size of outer IP header. 1493 */ 1494 static size_t 1495 ipsec_sp_hdrsiz(const struct secpolicy *sp, const struct mbuf *m) 1496 { 1497 struct ipsecrequest *isr; 1498 size_t siz; 1499 1500 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DATA)) { 1501 printf("%s: using SP\n", __func__); 1502 kdebug_secpolicy(sp); 1503 } 1504 1505 switch (sp->policy) { 1506 case IPSEC_POLICY_DISCARD: 1507 case IPSEC_POLICY_BYPASS: 1508 case IPSEC_POLICY_NONE: 1509 return 0; 1510 } 1511 1512 KASSERTMSG(sp->policy == IPSEC_POLICY_IPSEC, 1513 "invalid policy %u", sp->policy); 1514 1515 siz = 0; 1516 for (isr = sp->req; isr != NULL; isr = isr->next) { 1517 size_t clen = 0; 1518 struct secasvar *sav; 1519 1520 switch (isr->saidx.proto) { 1521 case IPPROTO_ESP: 1522 sav = ipsec_lookup_sa(isr, m); 1523 if (sav != NULL) { 1524 clen = esp_hdrsiz(sav); 1525 KEY_SA_UNREF(&sav); 1526 } else 1527 clen = esp_hdrsiz(NULL); 1528 break; 1529 case IPPROTO_AH: 1530 sav = ipsec_lookup_sa(isr, m); 1531 if (sav != NULL) { 1532 clen = ah_hdrsiz(sav); 1533 KEY_SA_UNREF(&sav); 1534 } else 1535 clen = ah_hdrsiz(NULL); 1536 break; 1537 case IPPROTO_IPCOMP: 1538 clen = sizeof(struct ipcomp); 1539 break; 1540 } 1541 1542 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) { 1543 switch (isr->saidx.dst.sa.sa_family) { 1544 case AF_INET: 1545 clen += sizeof(struct ip); 1546 break; 1547 #ifdef INET6 1548 case AF_INET6: 1549 clen += sizeof(struct ip6_hdr); 1550 break; 1551 #endif 1552 default: 1553 IPSECLOG(LOG_ERR, "unknown AF %d in " 1554 "IPsec tunnel SA\n", 1555 ((const struct sockaddr *)&isr->saidx.dst) 1556 ->sa_family); 1557 break; 1558 } 1559 } 1560 siz += clen; 1561 } 1562 1563 return siz; 1564 } 1565 1566 size_t 1567 ipsec_hdrsiz(struct mbuf *m, u_int dir, void *inp) 1568 { 1569 struct inpcb_hdr *inph = (struct inpcb_hdr *)inp; 1570 struct secpolicy *sp; 1571 int error; 1572 size_t size; 1573 1574 KASSERT(m != NULL); 1575 KASSERTMSG(inph == NULL || inph->inph_socket != NULL, 1576 "socket w/o inpcb"); 1577 1578 if (inph == NULL) 1579 sp = ipsec_getpolicybyaddr(m, dir, IP_FORWARDING, &error); 1580 else 1581 sp = ipsec_getpolicybysock(m, dir, inph, &error); 1582 1583 if (sp != NULL) { 1584 size = ipsec_sp_hdrsiz(sp, m); 1585 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DATA, "size:%zu.\n", size); 1586 KEY_SP_UNREF(&sp); 1587 } else { 1588 size = 0; 1589 } 1590 1591 return size; 1592 } 1593 1594 /* 1595 * Check the variable replay window. 1596 * ipsec_chkreplay() performs replay check before ICV verification. 1597 * ipsec_updatereplay() updates replay bitmap. This must be called after 1598 * ICV verification (it also performs replay check, which is usually done 1599 * beforehand). 1600 * 0 (zero) is returned if packet disallowed, 1 if packet permitted. 1601 * 1602 * based on RFC 2401. 1603 */ 1604 int 1605 ipsec_chkreplay(u_int32_t seq, const struct secasvar *sav) 1606 { 1607 const struct secreplay *replay; 1608 u_int32_t diff; 1609 int fr; 1610 u_int32_t wsizeb; /* constant: bits of window size */ 1611 int frlast; /* constant: last frame */ 1612 1613 IPSEC_SPLASSERT_SOFTNET(__func__); 1614 1615 KASSERT(sav != NULL); 1616 KASSERT(sav->replay != NULL); 1617 1618 replay = sav->replay; 1619 1620 if (replay->wsize == 0) 1621 return 1; /* no need to check replay. */ 1622 1623 /* constant */ 1624 frlast = replay->wsize - 1; 1625 wsizeb = replay->wsize << 3; 1626 1627 /* sequence number of 0 is invalid */ 1628 if (seq == 0) 1629 return 0; 1630 1631 /* first time is always okay */ 1632 if (replay->count == 0) 1633 return 1; 1634 1635 if (seq > replay->lastseq) { 1636 /* larger sequences are okay */ 1637 return 1; 1638 } else { 1639 /* seq is equal or less than lastseq. */ 1640 diff = replay->lastseq - seq; 1641 1642 /* over range to check, i.e. too old or wrapped */ 1643 if (diff >= wsizeb) 1644 return 0; 1645 1646 fr = frlast - diff / 8; 1647 1648 /* this packet already seen ? */ 1649 if ((replay->bitmap)[fr] & (1 << (diff % 8))) 1650 return 0; 1651 1652 /* out of order but good */ 1653 return 1; 1654 } 1655 } 1656 1657 /* 1658 * check replay counter whether to update or not. 1659 * OUT: 0: OK 1660 * 1: NG 1661 */ 1662 int 1663 ipsec_updatereplay(u_int32_t seq, const struct secasvar *sav) 1664 { 1665 struct secreplay *replay; 1666 u_int32_t diff; 1667 int fr; 1668 u_int32_t wsizeb; /* constant: bits of window size */ 1669 int frlast; /* constant: last frame */ 1670 1671 IPSEC_SPLASSERT_SOFTNET(__func__); 1672 1673 KASSERT(sav != NULL); 1674 KASSERT(sav->replay != NULL); 1675 1676 replay = sav->replay; 1677 1678 if (replay->wsize == 0) 1679 goto ok; /* no need to check replay. */ 1680 1681 /* constant */ 1682 frlast = replay->wsize - 1; 1683 wsizeb = replay->wsize << 3; 1684 1685 /* sequence number of 0 is invalid */ 1686 if (seq == 0) 1687 return 1; 1688 1689 /* first time */ 1690 if (replay->count == 0) { 1691 replay->lastseq = seq; 1692 memset(replay->bitmap, 0, replay->wsize); 1693 (replay->bitmap)[frlast] = 1; 1694 goto ok; 1695 } 1696 1697 if (seq > replay->lastseq) { 1698 /* seq is larger than lastseq. */ 1699 diff = seq - replay->lastseq; 1700 1701 /* new larger sequence number */ 1702 if (diff < wsizeb) { 1703 /* In window */ 1704 /* set bit for this packet */ 1705 vshiftl(replay->bitmap, diff, replay->wsize); 1706 (replay->bitmap)[frlast] |= 1; 1707 } else { 1708 /* this packet has a "way larger" */ 1709 memset(replay->bitmap, 0, replay->wsize); 1710 (replay->bitmap)[frlast] = 1; 1711 } 1712 replay->lastseq = seq; 1713 1714 /* larger is good */ 1715 } else { 1716 /* seq is equal or less than lastseq. */ 1717 diff = replay->lastseq - seq; 1718 1719 /* over range to check, i.e. too old or wrapped */ 1720 if (diff >= wsizeb) 1721 return 1; 1722 1723 fr = frlast - diff / 8; 1724 1725 /* this packet already seen ? */ 1726 if ((replay->bitmap)[fr] & (1 << (diff % 8))) 1727 return 1; 1728 1729 /* mark as seen */ 1730 (replay->bitmap)[fr] |= (1 << (diff % 8)); 1731 1732 /* out of order but good */ 1733 } 1734 1735 ok: 1736 if (replay->count == ~0) { 1737 char buf[IPSEC_LOGSASTRLEN]; 1738 1739 /* set overflow flag */ 1740 replay->overflow++; 1741 1742 /* don't increment, no more packets accepted */ 1743 if ((sav->flags & SADB_X_EXT_CYCSEQ) == 0) 1744 return 1; 1745 1746 IPSECLOG(LOG_WARNING, "replay counter made %d cycle. %s\n", 1747 replay->overflow, ipsec_logsastr(sav, buf, sizeof(buf))); 1748 } 1749 1750 replay->count++; 1751 1752 return 0; 1753 } 1754 1755 /* 1756 * shift variable length buffer to left. 1757 * IN: bitmap: pointer to the buffer 1758 * nbit: the number of to shift. 1759 * wsize: buffer size (bytes). 1760 */ 1761 static void 1762 vshiftl(unsigned char *bitmap, int nbit, int wsize) 1763 { 1764 int s, j, i; 1765 unsigned char over; 1766 1767 for (j = 0; j < nbit; j += 8) { 1768 s = (nbit - j < 8) ? (nbit - j): 8; 1769 bitmap[0] <<= s; 1770 for (i = 1; i < wsize; i++) { 1771 over = (bitmap[i] >> (8 - s)); 1772 bitmap[i] <<= s; 1773 bitmap[i-1] |= over; 1774 } 1775 } 1776 1777 return; 1778 } 1779 1780 /* Return a printable string for the address. */ 1781 const char * 1782 ipsec_address(const union sockaddr_union *sa, char *buf, size_t size) 1783 { 1784 switch (sa->sa.sa_family) { 1785 case AF_INET: 1786 in_print(buf, size, &sa->sin.sin_addr); 1787 return buf; 1788 #if INET6 1789 case AF_INET6: 1790 in6_print(buf, size, &sa->sin6.sin6_addr); 1791 return buf; 1792 #endif 1793 default: 1794 return "(unknown address family)"; 1795 } 1796 } 1797 1798 const char * 1799 ipsec_logsastr(const struct secasvar *sav, char *buf, size_t size) 1800 { 1801 const struct secasindex *saidx = &sav->sah->saidx; 1802 char sbuf[IPSEC_ADDRSTRLEN], dbuf[IPSEC_ADDRSTRLEN]; 1803 1804 KASSERTMSG(saidx->src.sa.sa_family == saidx->dst.sa.sa_family, 1805 "af family mismatch, src %u, dst %u", 1806 saidx->src.sa.sa_family, saidx->dst.sa.sa_family); 1807 1808 snprintf(buf, size, "SA(SPI=%u src=%s dst=%s)", 1809 (u_int32_t)ntohl(sav->spi), 1810 ipsec_address(&saidx->src, sbuf, sizeof(sbuf)), 1811 ipsec_address(&saidx->dst, dbuf, sizeof(dbuf))); 1812 1813 return buf; 1814 } 1815 1816 #ifdef INET6 1817 struct secpolicy * 1818 ipsec6_check_policy(struct mbuf *m, struct in6pcb *in6p, int flags, 1819 int *needipsecp, int *errorp) 1820 { 1821 struct secpolicy *sp = NULL; 1822 int s; 1823 int error = 0; 1824 int needipsec = 0; 1825 1826 if (ipsec_outdone(m)) { 1827 goto skippolicycheck; 1828 } 1829 s = splsoftnet(); 1830 if (in6p && ipsec_pcb_skip_ipsec(in6p->in6p_sp, IPSEC_DIR_OUTBOUND)) { 1831 splx(s); 1832 goto skippolicycheck; 1833 } 1834 sp = ipsec_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags, &error, in6p); 1835 splx(s); 1836 1837 /* 1838 * There are four return cases: 1839 * sp != NULL apply IPsec policy 1840 * sp == NULL, error == 0 no IPsec handling needed 1841 * sp == NULL, error == -EINVAL discard packet w/o error 1842 * sp == NULL, error != 0 discard packet, report error 1843 */ 1844 if (sp == NULL) { 1845 needipsec = 0; 1846 } else { 1847 needipsec = 1; 1848 } 1849 1850 skippolicycheck: 1851 *errorp = error; 1852 *needipsecp = needipsec; 1853 return sp; 1854 } 1855 1856 int 1857 ipsec6_input(struct mbuf *m) 1858 { 1859 int s, error; 1860 1861 s = splsoftnet(); 1862 error = ipsec_in_reject(m, NULL); 1863 splx(s); 1864 if (error) { 1865 return EINVAL; 1866 } 1867 1868 return 0; 1869 } 1870 #endif /* INET6 */ 1871 1872 /* 1873 * ----------------------------------------------------------------------------- 1874 */ 1875 1876 /* XXX this stuff doesn't belong here... */ 1877 1878 static struct xformsw *xforms = NULL; 1879 1880 /* 1881 * Register a transform; typically at system startup. 1882 */ 1883 void 1884 xform_register(struct xformsw *xsp) 1885 { 1886 xsp->xf_next = xforms; 1887 xforms = xsp; 1888 } 1889 1890 /* 1891 * Initialize transform support in an sav. 1892 */ 1893 int 1894 xform_init(struct secasvar *sav, int xftype) 1895 { 1896 struct xformsw *xsp; 1897 1898 if (sav->tdb_xform != NULL) /* previously initialized */ 1899 return 0; 1900 for (xsp = xforms; xsp; xsp = xsp->xf_next) 1901 if (xsp->xf_type == xftype) 1902 return (*xsp->xf_init)(sav, xsp); 1903 1904 IPSECLOG(LOG_DEBUG, "no match for xform type %d\n", xftype); 1905 return EINVAL; 1906 } 1907 1908 void 1909 nat_t_ports_get(struct mbuf *m, u_int16_t *dport, u_int16_t *sport) 1910 { 1911 struct m_tag *tag; 1912 1913 if ((tag = m_tag_find(m, PACKET_TAG_IPSEC_NAT_T_PORTS, NULL))) { 1914 *sport = ((u_int16_t *)(tag + 1))[0]; 1915 *dport = ((u_int16_t *)(tag + 1))[1]; 1916 } else 1917 *sport = *dport = 0; 1918 } 1919 1920 /* 1921 * XXXJRT This should be done as a protosw init call. 1922 */ 1923 void 1924 ipsec_attach(void) 1925 { 1926 1927 ipsec_output_init(); 1928 1929 ipsecstat_percpu = percpu_alloc(sizeof(uint64_t) * IPSEC_NSTATS); 1930 1931 sysctl_net_inet_ipsec_setup(NULL); 1932 #ifdef INET6 1933 sysctl_net_inet6_ipsec6_setup(NULL); 1934 #endif 1935 1936 ah_attach(); 1937 esp_attach(); 1938 ipcomp_attach(); 1939 ipe4_attach(); 1940 #ifdef TCP_SIGNATURE 1941 tcpsignature_attach(); 1942 #endif 1943 } 1944
Indexes created Tue Sep 23 02:09:52 GMT 2025