ipsec.c revision 1.157
1 /* $NetBSD: ipsec.c,v 1.157 2018/04/19 08:27:38 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 1.157 2018/04/19 08:27:38 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 /* initialize policy in PCB */ 1108 int 1109 ipsec_init_policy(struct socket *so, struct inpcbpolicy **policy) 1110 { 1111 struct inpcbpolicy *new; 1112 1113 KASSERT(so != NULL); 1114 KASSERT(policy != NULL); 1115 1116 new = kmem_intr_zalloc(sizeof(*new), KM_NOSLEEP); 1117 if (new == NULL) { 1118 IPSECLOG(LOG_DEBUG, "No more memory.\n"); 1119 return ENOBUFS; 1120 } 1121 1122 if (IPSEC_PRIVILEGED_SO(so)) 1123 new->priv = 1; 1124 else 1125 new->priv = 0; 1126 1127 /* 1128 * Set dummy SPs. Actual SPs will be allocated later if needed. 1129 */ 1130 new->sp_in = &ipsec_dummy_sp; 1131 new->sp_out = &ipsec_dummy_sp; 1132 1133 *policy = new; 1134 1135 return 0; 1136 } 1137 1138 static void 1139 ipsec_destroy_policy(struct secpolicy *sp) 1140 { 1141 1142 if (sp == &ipsec_dummy_sp) { 1143 ; /* It's dummy. No need to free it. */ 1144 } else { 1145 /* 1146 * We cannot destroy here because it can be called in 1147 * softint. So mark the SP as DEAD and let the timer 1148 * destroy it. See key_timehandler_spd. 1149 */ 1150 sp->state = IPSEC_SPSTATE_DEAD; 1151 } 1152 } 1153 1154 int 1155 ipsec_set_policy(void *inp, int optname, const void *request, size_t len, 1156 kauth_cred_t cred) 1157 { 1158 struct inpcb_hdr *inph = (struct inpcb_hdr *)inp; 1159 const struct sadb_x_policy *xpl; 1160 struct secpolicy *newsp, *oldsp; 1161 struct secpolicy **policy; 1162 int error; 1163 1164 KASSERT(!cpu_softintr_p()); 1165 KASSERT(inph != NULL); 1166 KASSERT(inph_locked(inph)); 1167 KASSERT(request != NULL); 1168 1169 if (len < sizeof(*xpl)) 1170 return EINVAL; 1171 xpl = (const struct sadb_x_policy *)request; 1172 1173 KASSERT(inph->inph_sp != NULL); 1174 1175 /* select direction */ 1176 switch (xpl->sadb_x_policy_dir) { 1177 case IPSEC_DIR_INBOUND: 1178 policy = &inph->inph_sp->sp_in; 1179 break; 1180 case IPSEC_DIR_OUTBOUND: 1181 policy = &inph->inph_sp->sp_out; 1182 break; 1183 default: 1184 IPSECLOG(LOG_ERR, "invalid direction=%u\n", 1185 xpl->sadb_x_policy_dir); 1186 return EINVAL; 1187 } 1188 1189 /* sanity check. */ 1190 if (policy == NULL || *policy == NULL) 1191 return EINVAL; 1192 1193 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DUMP)) { 1194 kdebug_sadb_xpolicy("set passed policy", request); 1195 } 1196 1197 /* check policy type */ 1198 /* ipsec_set_policy() accepts IPSEC, ENTRUST and BYPASS. */ 1199 if (xpl->sadb_x_policy_type == IPSEC_POLICY_DISCARD || 1200 xpl->sadb_x_policy_type == IPSEC_POLICY_NONE) 1201 return EINVAL; 1202 1203 /* check privileged socket */ 1204 if (xpl->sadb_x_policy_type == IPSEC_POLICY_BYPASS) { 1205 error = kauth_authorize_network(cred, KAUTH_NETWORK_IPSEC, 1206 KAUTH_REQ_NETWORK_IPSEC_BYPASS, NULL, NULL, NULL); 1207 if (error) 1208 return error; 1209 } 1210 1211 /* allocation new SP entry */ 1212 if ((newsp = key_msg2sp(xpl, len, &error)) == NULL) 1213 return error; 1214 1215 key_init_sp(newsp); 1216 newsp->created = time_uptime; 1217 /* Insert the global list for SPs for sockets */ 1218 key_socksplist_add(newsp); 1219 1220 /* clear old SP and set new SP */ 1221 oldsp = *policy; 1222 *policy = newsp; 1223 ipsec_destroy_policy(oldsp); 1224 1225 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DUMP)) { 1226 printf("%s: new policy\n", __func__); 1227 kdebug_secpolicy(newsp); 1228 } 1229 1230 return 0; 1231 } 1232 1233 int 1234 ipsec_get_policy(void *inp, const void *request, size_t len, 1235 struct mbuf **mp) 1236 { 1237 struct inpcb_hdr *inph = (struct inpcb_hdr *)inp; 1238 const struct sadb_x_policy *xpl; 1239 struct secpolicy *policy; 1240 1241 /* sanity check. */ 1242 if (inph == NULL || request == NULL || mp == NULL) 1243 return EINVAL; 1244 KASSERT(inph->inph_sp != NULL); 1245 if (len < sizeof(*xpl)) 1246 return EINVAL; 1247 xpl = (const struct sadb_x_policy *)request; 1248 1249 /* select direction */ 1250 switch (xpl->sadb_x_policy_dir) { 1251 case IPSEC_DIR_INBOUND: 1252 policy = inph->inph_sp->sp_in; 1253 break; 1254 case IPSEC_DIR_OUTBOUND: 1255 policy = inph->inph_sp->sp_out; 1256 break; 1257 default: 1258 IPSECLOG(LOG_ERR, "invalid direction=%u\n", 1259 xpl->sadb_x_policy_dir); 1260 return EINVAL; 1261 } 1262 1263 if (policy == NULL) 1264 return EINVAL; 1265 1266 *mp = key_sp2msg(policy, M_NOWAIT); 1267 if (!*mp) { 1268 IPSECLOG(LOG_DEBUG, "No more memory.\n"); 1269 return ENOBUFS; 1270 } 1271 1272 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DUMP)) { 1273 kdebug_mbuf(__func__, *mp); 1274 } 1275 1276 return 0; 1277 } 1278 1279 int 1280 ipsec_delete_pcbpolicy(void *inp) 1281 { 1282 struct inpcb_hdr *inph = (struct inpcb_hdr *)inp; 1283 1284 KASSERT(inph != NULL); 1285 1286 if (inph->inph_sp == NULL) 1287 return 0; 1288 1289 if (inph->inph_sp->sp_in != NULL) 1290 ipsec_destroy_policy(inph->inph_sp->sp_in); 1291 1292 if (inph->inph_sp->sp_out != NULL) 1293 ipsec_destroy_policy(inph->inph_sp->sp_out); 1294 1295 ipsec_invalpcbcache(inph->inph_sp, IPSEC_DIR_ANY); 1296 1297 ipsec_delpcbpolicy(inph->inph_sp); 1298 inph->inph_sp = NULL; 1299 1300 return 0; 1301 } 1302 1303 /* 1304 * Return the current level (either IPSEC_LEVEL_USE or IPSEC_LEVEL_REQUIRE). 1305 */ 1306 u_int 1307 ipsec_get_reqlevel(const struct ipsecrequest *isr) 1308 { 1309 u_int level = 0; 1310 u_int esp_trans_deflev, esp_net_deflev; 1311 u_int ah_trans_deflev, ah_net_deflev; 1312 1313 KASSERT(isr != NULL); 1314 KASSERT(isr->sp != NULL); 1315 KASSERTMSG( 1316 isr->sp->spidx.src.sa.sa_family == isr->sp->spidx.dst.sa.sa_family, 1317 "af family mismatch, src %u, dst %u", 1318 isr->sp->spidx.src.sa.sa_family, isr->sp->spidx.dst.sa.sa_family); 1319 1320 /* XXX note that we have ipseclog() expanded here - code sync issue */ 1321 #define IPSEC_CHECK_DEFAULT(lev) \ 1322 (((lev) != IPSEC_LEVEL_USE && (lev) != IPSEC_LEVEL_REQUIRE \ 1323 && (lev) != IPSEC_LEVEL_UNIQUE) ? \ 1324 (ipsec_debug ? log(LOG_INFO, "fixed system default level " #lev \ 1325 ":%d->%d\n", (lev), IPSEC_LEVEL_REQUIRE) : (void)0), \ 1326 (lev) = IPSEC_LEVEL_REQUIRE, (lev) \ 1327 : (lev)) 1328 1329 /* set default level */ 1330 switch (((struct sockaddr *)&isr->sp->spidx.src)->sa_family) { 1331 #ifdef INET 1332 case AF_INET: 1333 esp_trans_deflev = IPSEC_CHECK_DEFAULT(ip4_esp_trans_deflev); 1334 esp_net_deflev = IPSEC_CHECK_DEFAULT(ip4_esp_net_deflev); 1335 ah_trans_deflev = IPSEC_CHECK_DEFAULT(ip4_ah_trans_deflev); 1336 ah_net_deflev = IPSEC_CHECK_DEFAULT(ip4_ah_net_deflev); 1337 break; 1338 #endif 1339 #ifdef INET6 1340 case AF_INET6: 1341 esp_trans_deflev = IPSEC_CHECK_DEFAULT(ip6_esp_trans_deflev); 1342 esp_net_deflev = IPSEC_CHECK_DEFAULT(ip6_esp_net_deflev); 1343 ah_trans_deflev = IPSEC_CHECK_DEFAULT(ip6_ah_trans_deflev); 1344 ah_net_deflev = IPSEC_CHECK_DEFAULT(ip6_ah_net_deflev); 1345 break; 1346 #endif 1347 default: 1348 panic("%s: unknown af %u", __func__, 1349 isr->sp->spidx.src.sa.sa_family); 1350 } 1351 1352 #undef IPSEC_CHECK_DEFAULT 1353 1354 /* set level */ 1355 switch (isr->level) { 1356 case IPSEC_LEVEL_DEFAULT: 1357 switch (isr->saidx.proto) { 1358 case IPPROTO_ESP: 1359 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) 1360 level = esp_net_deflev; 1361 else 1362 level = esp_trans_deflev; 1363 break; 1364 case IPPROTO_AH: 1365 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) 1366 level = ah_net_deflev; 1367 else 1368 level = ah_trans_deflev; 1369 break; 1370 case IPPROTO_IPCOMP: 1371 /* 1372 * we don't really care, as IPcomp document says that 1373 * we shouldn't compress small packets 1374 */ 1375 level = IPSEC_LEVEL_USE; 1376 break; 1377 default: 1378 panic("%s: Illegal protocol defined %u", __func__, 1379 isr->saidx.proto); 1380 } 1381 break; 1382 1383 case IPSEC_LEVEL_USE: 1384 case IPSEC_LEVEL_REQUIRE: 1385 level = isr->level; 1386 break; 1387 case IPSEC_LEVEL_UNIQUE: 1388 level = IPSEC_LEVEL_REQUIRE; 1389 break; 1390 1391 default: 1392 panic("%s: Illegal IPsec level %u", __func__, isr->level); 1393 } 1394 1395 return level; 1396 } 1397 1398 /* 1399 * Check security policy requirements against the actual packet contents. 1400 * 1401 * If the SP requires an IPsec packet, and the packet was neither AH nor ESP, 1402 * then kick it. 1403 */ 1404 static int 1405 ipsec_sp_reject(const struct secpolicy *sp, const struct mbuf *m) 1406 { 1407 struct ipsecrequest *isr; 1408 1409 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DATA)) { 1410 printf("%s: using SP\n", __func__); 1411 kdebug_secpolicy(sp); 1412 } 1413 1414 /* check policy */ 1415 switch (sp->policy) { 1416 case IPSEC_POLICY_DISCARD: 1417 return 1; 1418 case IPSEC_POLICY_BYPASS: 1419 case IPSEC_POLICY_NONE: 1420 return 0; 1421 } 1422 1423 KASSERTMSG(sp->policy == IPSEC_POLICY_IPSEC, 1424 "invalid policy %u", sp->policy); 1425 1426 /* XXX should compare policy against ipsec header history */ 1427 1428 for (isr = sp->req; isr != NULL; isr = isr->next) { 1429 if (ipsec_get_reqlevel(isr) != IPSEC_LEVEL_REQUIRE) 1430 continue; 1431 switch (isr->saidx.proto) { 1432 case IPPROTO_ESP: 1433 if ((m->m_flags & M_DECRYPTED) == 0) { 1434 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 1435 "ESP m_flags:%x\n", m->m_flags); 1436 return 1; 1437 } 1438 break; 1439 case IPPROTO_AH: 1440 if ((m->m_flags & M_AUTHIPHDR) == 0) { 1441 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 1442 "AH m_flags:%x\n", m->m_flags); 1443 return 1; 1444 } 1445 break; 1446 case IPPROTO_IPCOMP: 1447 /* 1448 * We don't really care, as IPcomp document 1449 * says that we shouldn't compress small 1450 * packets, IPComp policy should always be 1451 * treated as being in "use" level. 1452 */ 1453 break; 1454 } 1455 } 1456 1457 return 0; 1458 } 1459 1460 /* 1461 * Check security policy requirements. 1462 */ 1463 int 1464 ipsec_in_reject(struct mbuf *m, void *inp) 1465 { 1466 struct inpcb_hdr *inph = (struct inpcb_hdr *)inp; 1467 struct secpolicy *sp; 1468 int error; 1469 int result; 1470 1471 KASSERT(m != NULL); 1472 1473 if (inph == NULL) 1474 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND, 1475 IP_FORWARDING, &error); 1476 else 1477 sp = ipsec_getpolicybysock(m, IPSEC_DIR_INBOUND, 1478 inph, &error); 1479 1480 if (sp != NULL) { 1481 result = ipsec_sp_reject(sp, m); 1482 if (result) 1483 IPSEC_STATINC(IPSEC_STAT_IN_POLVIO); 1484 KEY_SP_UNREF(&sp); 1485 } else { 1486 result = 0; 1487 } 1488 return result; 1489 } 1490 1491 /* 1492 * Compute the byte size to be occupied by the IPsec header. If it is 1493 * tunneled, it includes the size of outer IP header. 1494 */ 1495 static size_t 1496 ipsec_sp_hdrsiz(const struct secpolicy *sp, const struct mbuf *m) 1497 { 1498 struct ipsecrequest *isr; 1499 size_t siz; 1500 1501 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DATA)) { 1502 printf("%s: using SP\n", __func__); 1503 kdebug_secpolicy(sp); 1504 } 1505 1506 switch (sp->policy) { 1507 case IPSEC_POLICY_DISCARD: 1508 case IPSEC_POLICY_BYPASS: 1509 case IPSEC_POLICY_NONE: 1510 return 0; 1511 } 1512 1513 KASSERTMSG(sp->policy == IPSEC_POLICY_IPSEC, 1514 "invalid policy %u", sp->policy); 1515 1516 siz = 0; 1517 for (isr = sp->req; isr != NULL; isr = isr->next) { 1518 size_t clen = 0; 1519 struct secasvar *sav; 1520 1521 switch (isr->saidx.proto) { 1522 case IPPROTO_ESP: 1523 sav = ipsec_lookup_sa(isr, m); 1524 if (sav != NULL) { 1525 clen = esp_hdrsiz(sav); 1526 KEY_SA_UNREF(&sav); 1527 } else 1528 clen = esp_hdrsiz(NULL); 1529 break; 1530 case IPPROTO_AH: 1531 sav = ipsec_lookup_sa(isr, m); 1532 if (sav != NULL) { 1533 clen = ah_hdrsiz(sav); 1534 KEY_SA_UNREF(&sav); 1535 } else 1536 clen = ah_hdrsiz(NULL); 1537 break; 1538 case IPPROTO_IPCOMP: 1539 clen = sizeof(struct ipcomp); 1540 break; 1541 } 1542 1543 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) { 1544 switch (isr->saidx.dst.sa.sa_family) { 1545 case AF_INET: 1546 clen += sizeof(struct ip); 1547 break; 1548 #ifdef INET6 1549 case AF_INET6: 1550 clen += sizeof(struct ip6_hdr); 1551 break; 1552 #endif 1553 default: 1554 IPSECLOG(LOG_ERR, "unknown AF %d in " 1555 "IPsec tunnel SA\n", 1556 ((const struct sockaddr *)&isr->saidx.dst) 1557 ->sa_family); 1558 break; 1559 } 1560 } 1561 siz += clen; 1562 } 1563 1564 return siz; 1565 } 1566 1567 size_t 1568 ipsec_hdrsiz(struct mbuf *m, u_int dir, void *inp) 1569 { 1570 struct inpcb_hdr *inph = (struct inpcb_hdr *)inp; 1571 struct secpolicy *sp; 1572 int error; 1573 size_t size; 1574 1575 KASSERT(m != NULL); 1576 KASSERTMSG(inph == NULL || inph->inph_socket != NULL, 1577 "socket w/o inpcb"); 1578 1579 if (inph == NULL) 1580 sp = ipsec_getpolicybyaddr(m, dir, IP_FORWARDING, &error); 1581 else 1582 sp = ipsec_getpolicybysock(m, dir, inph, &error); 1583 1584 if (sp != NULL) { 1585 size = ipsec_sp_hdrsiz(sp, m); 1586 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DATA, "size:%zu.\n", size); 1587 KEY_SP_UNREF(&sp); 1588 } else { 1589 size = 0; 1590 } 1591 1592 return size; 1593 } 1594 1595 /* 1596 * Check the variable replay window. 1597 * ipsec_chkreplay() performs replay check before ICV verification. 1598 * ipsec_updatereplay() updates replay bitmap. This must be called after 1599 * ICV verification (it also performs replay check, which is usually done 1600 * beforehand). 1601 * 0 (zero) is returned if packet disallowed, 1 if packet permitted. 1602 * 1603 * based on RFC 2401. 1604 */ 1605 int 1606 ipsec_chkreplay(u_int32_t seq, const struct secasvar *sav) 1607 { 1608 const struct secreplay *replay; 1609 u_int32_t diff; 1610 int fr; 1611 u_int32_t wsizeb; /* constant: bits of window size */ 1612 int frlast; /* constant: last frame */ 1613 1614 IPSEC_SPLASSERT_SOFTNET(__func__); 1615 1616 KASSERT(sav != NULL); 1617 KASSERT(sav->replay != NULL); 1618 1619 replay = sav->replay; 1620 1621 if (replay->wsize == 0) 1622 return 1; /* no need to check replay. */ 1623 1624 /* constant */ 1625 frlast = replay->wsize - 1; 1626 wsizeb = replay->wsize << 3; 1627 1628 /* sequence number of 0 is invalid */ 1629 if (seq == 0) 1630 return 0; 1631 1632 /* first time is always okay */ 1633 if (replay->count == 0) 1634 return 1; 1635 1636 if (seq > replay->lastseq) { 1637 /* larger sequences are okay */ 1638 return 1; 1639 } else { 1640 /* seq is equal or less than lastseq. */ 1641 diff = replay->lastseq - seq; 1642 1643 /* over range to check, i.e. too old or wrapped */ 1644 if (diff >= wsizeb) 1645 return 0; 1646 1647 fr = frlast - diff / 8; 1648 1649 /* this packet already seen ? */ 1650 if ((replay->bitmap)[fr] & (1 << (diff % 8))) 1651 return 0; 1652 1653 /* out of order but good */ 1654 return 1; 1655 } 1656 } 1657 1658 /* 1659 * check replay counter whether to update or not. 1660 * OUT: 0: OK 1661 * 1: NG 1662 */ 1663 int 1664 ipsec_updatereplay(u_int32_t seq, const struct secasvar *sav) 1665 { 1666 struct secreplay *replay; 1667 u_int32_t diff; 1668 int fr; 1669 u_int32_t wsizeb; /* constant: bits of window size */ 1670 int frlast; /* constant: last frame */ 1671 1672 IPSEC_SPLASSERT_SOFTNET(__func__); 1673 1674 KASSERT(sav != NULL); 1675 KASSERT(sav->replay != NULL); 1676 1677 replay = sav->replay; 1678 1679 if (replay->wsize == 0) 1680 goto ok; /* no need to check replay. */ 1681 1682 /* constant */ 1683 frlast = replay->wsize - 1; 1684 wsizeb = replay->wsize << 3; 1685 1686 /* sequence number of 0 is invalid */ 1687 if (seq == 0) 1688 return 1; 1689 1690 /* first time */ 1691 if (replay->count == 0) { 1692 replay->lastseq = seq; 1693 memset(replay->bitmap, 0, replay->wsize); 1694 (replay->bitmap)[frlast] = 1; 1695 goto ok; 1696 } 1697 1698 if (seq > replay->lastseq) { 1699 /* seq is larger than lastseq. */ 1700 diff = seq - replay->lastseq; 1701 1702 /* new larger sequence number */ 1703 if (diff < wsizeb) { 1704 /* In window */ 1705 /* set bit for this packet */ 1706 vshiftl(replay->bitmap, diff, replay->wsize); 1707 (replay->bitmap)[frlast] |= 1; 1708 } else { 1709 /* this packet has a "way larger" */ 1710 memset(replay->bitmap, 0, replay->wsize); 1711 (replay->bitmap)[frlast] = 1; 1712 } 1713 replay->lastseq = seq; 1714 1715 /* larger is good */ 1716 } else { 1717 /* seq is equal or less than lastseq. */ 1718 diff = replay->lastseq - seq; 1719 1720 /* over range to check, i.e. too old or wrapped */ 1721 if (diff >= wsizeb) 1722 return 1; 1723 1724 fr = frlast - diff / 8; 1725 1726 /* this packet already seen ? */ 1727 if ((replay->bitmap)[fr] & (1 << (diff % 8))) 1728 return 1; 1729 1730 /* mark as seen */ 1731 (replay->bitmap)[fr] |= (1 << (diff % 8)); 1732 1733 /* out of order but good */ 1734 } 1735 1736 ok: 1737 if (replay->count == ~0) { 1738 char buf[IPSEC_LOGSASTRLEN]; 1739 1740 /* set overflow flag */ 1741 replay->overflow++; 1742 1743 /* don't increment, no more packets accepted */ 1744 if ((sav->flags & SADB_X_EXT_CYCSEQ) == 0) 1745 return 1; 1746 1747 IPSECLOG(LOG_WARNING, "replay counter made %d cycle. %s\n", 1748 replay->overflow, ipsec_logsastr(sav, buf, sizeof(buf))); 1749 } 1750 1751 replay->count++; 1752 1753 return 0; 1754 } 1755 1756 /* 1757 * shift variable length buffer to left. 1758 * IN: bitmap: pointer to the buffer 1759 * nbit: the number of to shift. 1760 * wsize: buffer size (bytes). 1761 */ 1762 static void 1763 vshiftl(unsigned char *bitmap, int nbit, int wsize) 1764 { 1765 int s, j, i; 1766 unsigned char over; 1767 1768 for (j = 0; j < nbit; j += 8) { 1769 s = (nbit - j < 8) ? (nbit - j): 8; 1770 bitmap[0] <<= s; 1771 for (i = 1; i < wsize; i++) { 1772 over = (bitmap[i] >> (8 - s)); 1773 bitmap[i] <<= s; 1774 bitmap[i-1] |= over; 1775 } 1776 } 1777 1778 return; 1779 } 1780 1781 /* Return a printable string for the address. */ 1782 const char * 1783 ipsec_address(const union sockaddr_union *sa, char *buf, size_t size) 1784 { 1785 switch (sa->sa.sa_family) { 1786 case AF_INET: 1787 in_print(buf, size, &sa->sin.sin_addr); 1788 return buf; 1789 #if INET6 1790 case AF_INET6: 1791 in6_print(buf, size, &sa->sin6.sin6_addr); 1792 return buf; 1793 #endif 1794 default: 1795 return "(unknown address family)"; 1796 } 1797 } 1798 1799 const char * 1800 ipsec_logsastr(const struct secasvar *sav, char *buf, size_t size) 1801 { 1802 const struct secasindex *saidx = &sav->sah->saidx; 1803 char sbuf[IPSEC_ADDRSTRLEN], dbuf[IPSEC_ADDRSTRLEN]; 1804 1805 KASSERTMSG(saidx->src.sa.sa_family == saidx->dst.sa.sa_family, 1806 "af family mismatch, src %u, dst %u", 1807 saidx->src.sa.sa_family, saidx->dst.sa.sa_family); 1808 1809 snprintf(buf, size, "SA(SPI=%u src=%s dst=%s)", 1810 (u_int32_t)ntohl(sav->spi), 1811 ipsec_address(&saidx->src, sbuf, sizeof(sbuf)), 1812 ipsec_address(&saidx->dst, dbuf, sizeof(dbuf))); 1813 1814 return buf; 1815 } 1816 1817 void 1818 ipsec_dumpmbuf(struct mbuf *m) 1819 { 1820 int totlen; 1821 int i; 1822 u_char *p; 1823 1824 totlen = 0; 1825 printf("---\n"); 1826 while (m) { 1827 p = mtod(m, u_char *); 1828 for (i = 0; i < m->m_len; i++) { 1829 printf("%02x ", p[i]); 1830 totlen++; 1831 if (totlen % 16 == 0) 1832 printf("\n"); 1833 } 1834 m = m->m_next; 1835 } 1836 if (totlen % 16 != 0) 1837 printf("\n"); 1838 printf("---\n"); 1839 } 1840 1841 #ifdef INET6 1842 struct secpolicy * 1843 ipsec6_check_policy(struct mbuf *m, struct in6pcb *in6p, int flags, 1844 int *needipsecp, int *errorp) 1845 { 1846 struct secpolicy *sp = NULL; 1847 int s; 1848 int error = 0; 1849 int needipsec = 0; 1850 1851 if (ipsec_outdone(m)) { 1852 goto skippolicycheck; 1853 } 1854 s = splsoftnet(); 1855 if (in6p && ipsec_pcb_skip_ipsec(in6p->in6p_sp, IPSEC_DIR_OUTBOUND)) { 1856 splx(s); 1857 goto skippolicycheck; 1858 } 1859 sp = ipsec_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags, &error, in6p); 1860 splx(s); 1861 1862 /* 1863 * There are four return cases: 1864 * sp != NULL apply IPsec policy 1865 * sp == NULL, error == 0 no IPsec handling needed 1866 * sp == NULL, error == -EINVAL discard packet w/o error 1867 * sp == NULL, error != 0 discard packet, report error 1868 */ 1869 if (sp == NULL) { 1870 needipsec = 0; 1871 } else { 1872 needipsec = 1; 1873 } 1874 1875 skippolicycheck: 1876 *errorp = error; 1877 *needipsecp = needipsec; 1878 return sp; 1879 } 1880 1881 int 1882 ipsec6_input(struct mbuf *m) 1883 { 1884 int s, error; 1885 1886 s = splsoftnet(); 1887 error = ipsec_in_reject(m, NULL); 1888 splx(s); 1889 if (error) { 1890 return EINVAL; 1891 } 1892 1893 return 0; 1894 } 1895 #endif /* INET6 */ 1896 1897 /* 1898 * ----------------------------------------------------------------------------- 1899 */ 1900 1901 /* XXX this stuff doesn't belong here... */ 1902 1903 static struct xformsw *xforms = NULL; 1904 1905 /* 1906 * Register a transform; typically at system startup. 1907 */ 1908 void 1909 xform_register(struct xformsw *xsp) 1910 { 1911 xsp->xf_next = xforms; 1912 xforms = xsp; 1913 } 1914 1915 /* 1916 * Initialize transform support in an sav. 1917 */ 1918 int 1919 xform_init(struct secasvar *sav, int xftype) 1920 { 1921 struct xformsw *xsp; 1922 1923 if (sav->tdb_xform != NULL) /* previously initialized */ 1924 return 0; 1925 for (xsp = xforms; xsp; xsp = xsp->xf_next) 1926 if (xsp->xf_type == xftype) 1927 return (*xsp->xf_init)(sav, xsp); 1928 1929 IPSECLOG(LOG_DEBUG, "no match for xform type %d\n", xftype); 1930 return EINVAL; 1931 } 1932 1933 void 1934 nat_t_ports_get(struct mbuf *m, u_int16_t *dport, u_int16_t *sport) 1935 { 1936 struct m_tag *tag; 1937 1938 if ((tag = m_tag_find(m, PACKET_TAG_IPSEC_NAT_T_PORTS, NULL))) { 1939 *sport = ((u_int16_t *)(tag + 1))[0]; 1940 *dport = ((u_int16_t *)(tag + 1))[1]; 1941 } else 1942 *sport = *dport = 0; 1943 } 1944 1945 /* 1946 * XXXJRT This should be done as a protosw init call. 1947 */ 1948 void 1949 ipsec_attach(void) 1950 { 1951 1952 ipsec_output_init(); 1953 1954 ipsecstat_percpu = percpu_alloc(sizeof(uint64_t) * IPSEC_NSTATS); 1955 1956 sysctl_net_inet_ipsec_setup(NULL); 1957 #ifdef INET6 1958 sysctl_net_inet6_ipsec6_setup(NULL); 1959 #endif 1960 1961 ah_attach(); 1962 esp_attach(); 1963 ipcomp_attach(); 1964 ipe4_attach(); 1965 #ifdef TCP_SIGNATURE 1966 tcpsignature_attach(); 1967 #endif 1968 } 1969
Indexes created Tue Sep 23 14:10:03 GMT 2025