ipsec.c revision 1.151.2.4
1 /* $NetBSD: ipsec.c,v 1.151.2.4 2018/05/21 04:36:16 pgoyette 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 1.151.2.4 2018/05/21 04:36:16 pgoyette 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 ipsec_ip_input(struct mbuf *m, bool forward) 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 (!forward || !(m->m_flags & M_CANFASTFWD)) { 713 return 0; 714 } 715 716 /* 717 * Peek at the outbound SP for this packet to determine if 718 * it is a Fast Forward candidate. 719 */ 720 s = splsoftnet(); 721 sp = ipsec_checkpolicy(m, IPSEC_DIR_OUTBOUND, IP_FORWARDING, 722 &error, NULL); 723 if (sp != NULL) { 724 m->m_flags &= ~M_CANFASTFWD; 725 KEY_SP_UNREF(&sp); 726 } 727 splx(s); 728 729 return 0; 730 } 731 732 /* 733 * If the packet is routed over IPsec tunnel, tell the originator the 734 * tunnel MTU. 735 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz 736 * 737 * XXX: Quick hack!!! 738 * 739 * XXX: And what if the MTU goes negative? 740 */ 741 void 742 ipsec_mtu(struct mbuf *m, int *destmtu) 743 { 744 struct secpolicy *sp; 745 size_t ipsechdr; 746 int error; 747 748 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, IP_FORWARDING, 749 &error); 750 if (sp == NULL) { 751 return; 752 } 753 754 /* Count IPsec header size. */ 755 ipsechdr = ipsec_sp_hdrsiz(sp, m); 756 757 /* 758 * Find the correct route for outer IP header, compute tunnel MTU. 759 */ 760 if (sp->req) { 761 struct secasvar *sav; 762 763 sav = ipsec_lookup_sa(sp->req, m); 764 if (sav != NULL) { 765 struct route *ro; 766 struct rtentry *rt; 767 768 ro = &sav->sah->sa_route; 769 rt = rtcache_validate(ro); 770 if (rt && rt->rt_ifp) { 771 *destmtu = rt->rt_rmx.rmx_mtu ? 772 rt->rt_rmx.rmx_mtu : rt->rt_ifp->if_mtu; 773 *destmtu -= ipsechdr; 774 } 775 rtcache_unref(rt, ro); 776 KEY_SA_UNREF(&sav); 777 } 778 } 779 KEY_SP_UNREF(&sp); 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 int error; 819 820 KASSERT(m != NULL); 821 M_VERIFY_PACKET(m); 822 823 if (m->m_pkthdr.len < sizeof(struct ip)) { 824 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 825 "pkthdr.len(%d) < sizeof(struct ip), ignored.\n", 826 m->m_pkthdr.len); 827 return EINVAL; 828 } 829 830 if (m->m_len >= sizeof(*ip)) { 831 ip = mtod(m, struct ip *); 832 } else { 833 m_copydata(m, 0, sizeof(ipbuf), &ipbuf); 834 ip = &ipbuf; 835 } 836 v = ip->ip_v; 837 switch (v) { 838 case 4: 839 error = ipsec4_setspidx_ipaddr(m, spidx); 840 if (error) 841 return error; 842 ipsec4_get_ulp(m, spidx, needport); 843 return 0; 844 #ifdef INET6 845 case 6: 846 if (m->m_pkthdr.len < sizeof(struct ip6_hdr)) { 847 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 848 "pkthdr.len(%d) < sizeof(struct ip6_hdr), " 849 "ignored.\n", m->m_pkthdr.len); 850 return EINVAL; 851 } 852 error = ipsec6_setspidx_ipaddr(m, spidx); 853 if (error) 854 return error; 855 ipsec6_get_ulp(m, spidx, needport); 856 return 0; 857 #endif 858 default: 859 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 860 "unknown IP version %u, ignored.\n", v); 861 return EINVAL; 862 } 863 } 864 865 static void 866 ipsec4_get_ulp(struct mbuf *m, struct secpolicyindex *spidx, int needport) 867 { 868 u_int8_t nxt; 869 int off; 870 871 KASSERT(m != NULL); 872 KASSERTMSG(m->m_pkthdr.len >= sizeof(struct ip), "packet too short"); 873 874 /* NB: ip_input() flips it into host endian XXX need more checking */ 875 if (m->m_len >= sizeof(struct ip)) { 876 struct ip *ip = mtod(m, struct ip *); 877 if (ip->ip_off & htons(IP_MF | IP_OFFMASK)) 878 goto done; 879 off = ip->ip_hl << 2; 880 nxt = ip->ip_p; 881 } else { 882 struct ip ih; 883 884 m_copydata(m, 0, sizeof(struct ip), &ih); 885 if (ih.ip_off & htons(IP_MF | IP_OFFMASK)) 886 goto done; 887 off = ih.ip_hl << 2; 888 nxt = ih.ip_p; 889 } 890 891 while (off < m->m_pkthdr.len) { 892 struct ip6_ext ip6e; 893 struct tcphdr th; 894 struct udphdr uh; 895 struct icmp icmph; 896 897 switch (nxt) { 898 case IPPROTO_TCP: 899 spidx->ul_proto = nxt; 900 if (!needport) 901 goto done_proto; 902 if (off + sizeof(struct tcphdr) > m->m_pkthdr.len) 903 goto done; 904 m_copydata(m, off, sizeof(th), &th); 905 spidx->src.sin.sin_port = th.th_sport; 906 spidx->dst.sin.sin_port = th.th_dport; 907 return; 908 case IPPROTO_UDP: 909 spidx->ul_proto = nxt; 910 if (!needport) 911 goto done_proto; 912 if (off + sizeof(struct udphdr) > m->m_pkthdr.len) 913 goto done; 914 m_copydata(m, off, sizeof(uh), &uh); 915 spidx->src.sin.sin_port = uh.uh_sport; 916 spidx->dst.sin.sin_port = uh.uh_dport; 917 return; 918 case IPPROTO_AH: 919 if (off + sizeof(ip6e) > m->m_pkthdr.len) 920 goto done; 921 /* XXX sigh, this works but is totally bogus */ 922 m_copydata(m, off, sizeof(ip6e), &ip6e); 923 off += (ip6e.ip6e_len + 2) << 2; 924 nxt = ip6e.ip6e_nxt; 925 break; 926 case IPPROTO_ICMP: 927 spidx->ul_proto = nxt; 928 if (off + sizeof(struct icmp) > m->m_pkthdr.len) 929 goto done; 930 m_copydata(m, off, sizeof(icmph), &icmph); 931 ((struct sockaddr_in *)&spidx->src)->sin_port = 932 htons((uint16_t)icmph.icmp_type); 933 ((struct sockaddr_in *)&spidx->dst)->sin_port = 934 htons((uint16_t)icmph.icmp_code); 935 return; 936 default: 937 /* XXX intermediate headers??? */ 938 spidx->ul_proto = nxt; 939 goto done_proto; 940 } 941 } 942 done: 943 spidx->ul_proto = IPSEC_ULPROTO_ANY; 944 done_proto: 945 spidx->src.sin.sin_port = IPSEC_PORT_ANY; 946 spidx->dst.sin.sin_port = IPSEC_PORT_ANY; 947 } 948 949 static int 950 ipsec4_setspidx_ipaddr(struct mbuf *m, struct secpolicyindex *spidx) 951 { 952 static const struct sockaddr_in template = { 953 sizeof(struct sockaddr_in), 954 AF_INET, 955 0, { 0 }, { 0, 0, 0, 0, 0, 0, 0, 0 } 956 }; 957 958 spidx->src.sin = template; 959 spidx->dst.sin = template; 960 961 if (m->m_len < sizeof(struct ip)) { 962 m_copydata(m, offsetof(struct ip, ip_src), 963 sizeof(struct in_addr), &spidx->src.sin.sin_addr); 964 m_copydata(m, offsetof(struct ip, ip_dst), 965 sizeof(struct in_addr), &spidx->dst.sin.sin_addr); 966 } else { 967 struct ip *ip = mtod(m, struct ip *); 968 spidx->src.sin.sin_addr = ip->ip_src; 969 spidx->dst.sin.sin_addr = ip->ip_dst; 970 } 971 972 spidx->prefs = sizeof(struct in_addr) << 3; 973 spidx->prefd = sizeof(struct in_addr) << 3; 974 975 return 0; 976 } 977 978 #ifdef INET6 979 static void 980 ipsec6_get_ulp(struct mbuf *m, struct secpolicyindex *spidx, int needport) 981 { 982 int off, nxt; 983 struct tcphdr th; 984 struct udphdr uh; 985 struct icmp6_hdr icmph; 986 987 KASSERT(m != NULL); 988 989 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DUMP)) { 990 kdebug_mbuf(__func__, m); 991 } 992 993 /* set default */ 994 spidx->ul_proto = IPSEC_ULPROTO_ANY; 995 ((struct sockaddr_in6 *)&spidx->src)->sin6_port = IPSEC_PORT_ANY; 996 ((struct sockaddr_in6 *)&spidx->dst)->sin6_port = IPSEC_PORT_ANY; 997 998 nxt = -1; 999 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt); 1000 if (off < 0 || m->m_pkthdr.len < off) 1001 return; 1002 1003 switch (nxt) { 1004 case IPPROTO_TCP: 1005 spidx->ul_proto = nxt; 1006 if (!needport) 1007 break; 1008 if (off + sizeof(struct tcphdr) > m->m_pkthdr.len) 1009 break; 1010 m_copydata(m, off, sizeof(th), &th); 1011 ((struct sockaddr_in6 *)&spidx->src)->sin6_port = th.th_sport; 1012 ((struct sockaddr_in6 *)&spidx->dst)->sin6_port = th.th_dport; 1013 break; 1014 case IPPROTO_UDP: 1015 spidx->ul_proto = nxt; 1016 if (!needport) 1017 break; 1018 if (off + sizeof(struct udphdr) > m->m_pkthdr.len) 1019 break; 1020 m_copydata(m, off, sizeof(uh), &uh); 1021 ((struct sockaddr_in6 *)&spidx->src)->sin6_port = uh.uh_sport; 1022 ((struct sockaddr_in6 *)&spidx->dst)->sin6_port = uh.uh_dport; 1023 break; 1024 case IPPROTO_ICMPV6: 1025 spidx->ul_proto = nxt; 1026 if (off + sizeof(struct icmp6_hdr) > m->m_pkthdr.len) 1027 break; 1028 m_copydata(m, off, sizeof(icmph), &icmph); 1029 ((struct sockaddr_in6 *)&spidx->src)->sin6_port = 1030 htons((uint16_t)icmph.icmp6_type); 1031 ((struct sockaddr_in6 *)&spidx->dst)->sin6_port = 1032 htons((uint16_t)icmph.icmp6_code); 1033 break; 1034 default: 1035 /* XXX intermediate headers??? */ 1036 spidx->ul_proto = nxt; 1037 break; 1038 } 1039 } 1040 1041 static int 1042 ipsec6_setspidx_ipaddr(struct mbuf *m, struct secpolicyindex *spidx) 1043 { 1044 struct ip6_hdr *ip6 = NULL; 1045 struct ip6_hdr ip6buf; 1046 struct sockaddr_in6 *sin6; 1047 1048 if (m->m_len >= sizeof(*ip6)) { 1049 ip6 = mtod(m, struct ip6_hdr *); 1050 } else { 1051 m_copydata(m, 0, sizeof(ip6buf), &ip6buf); 1052 ip6 = &ip6buf; 1053 } 1054 1055 sin6 = (struct sockaddr_in6 *)&spidx->src; 1056 memset(sin6, 0, sizeof(*sin6)); 1057 sin6->sin6_family = AF_INET6; 1058 sin6->sin6_len = sizeof(struct sockaddr_in6); 1059 memcpy(&sin6->sin6_addr, &ip6->ip6_src, sizeof(ip6->ip6_src)); 1060 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) { 1061 sin6->sin6_addr.s6_addr16[1] = 0; 1062 sin6->sin6_scope_id = ntohs(ip6->ip6_src.s6_addr16[1]); 1063 } 1064 spidx->prefs = sizeof(struct in6_addr) << 3; 1065 1066 sin6 = (struct sockaddr_in6 *)&spidx->dst; 1067 memset(sin6, 0, sizeof(*sin6)); 1068 sin6->sin6_family = AF_INET6; 1069 sin6->sin6_len = sizeof(struct sockaddr_in6); 1070 memcpy(&sin6->sin6_addr, &ip6->ip6_dst, sizeof(ip6->ip6_dst)); 1071 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) { 1072 sin6->sin6_addr.s6_addr16[1] = 0; 1073 sin6->sin6_scope_id = ntohs(ip6->ip6_dst.s6_addr16[1]); 1074 } 1075 spidx->prefd = sizeof(struct in6_addr) << 3; 1076 1077 return 0; 1078 } 1079 #endif 1080 1081 static void 1082 ipsec_delpcbpolicy(struct inpcbpolicy *p) 1083 { 1084 1085 kmem_intr_free(p, sizeof(*p)); 1086 } 1087 1088 int 1089 ipsec_init_pcbpolicy(struct socket *so, struct inpcbpolicy **policy) 1090 { 1091 struct inpcbpolicy *new; 1092 1093 KASSERT(so != NULL); 1094 KASSERT(policy != NULL); 1095 1096 new = kmem_intr_zalloc(sizeof(*new), KM_NOSLEEP); 1097 if (new == NULL) { 1098 IPSECLOG(LOG_DEBUG, "No more memory.\n"); 1099 return ENOBUFS; 1100 } 1101 1102 if (IPSEC_PRIVILEGED_SO(so)) 1103 new->priv = 1; 1104 else 1105 new->priv = 0; 1106 1107 /* 1108 * Set dummy SPs. Actual SPs will be allocated later if needed. 1109 */ 1110 new->sp_in = &ipsec_dummy_sp; 1111 new->sp_out = &ipsec_dummy_sp; 1112 1113 *policy = new; 1114 1115 return 0; 1116 } 1117 1118 static void 1119 ipsec_destroy_policy(struct secpolicy *sp) 1120 { 1121 1122 if (sp == &ipsec_dummy_sp) { 1123 ; /* It's dummy. No need to free it. */ 1124 } else { 1125 /* 1126 * We cannot destroy here because it can be called in 1127 * softint. So mark the SP as DEAD and let the timer 1128 * destroy it. See key_timehandler_spd. 1129 */ 1130 sp->state = IPSEC_SPSTATE_DEAD; 1131 } 1132 } 1133 1134 int 1135 ipsec_set_policy(void *inp, const void *request, size_t len, 1136 kauth_cred_t cred) 1137 { 1138 struct inpcb_hdr *inph = (struct inpcb_hdr *)inp; 1139 const struct sadb_x_policy *xpl; 1140 struct secpolicy *newsp, *oldsp; 1141 struct secpolicy **policy; 1142 int error; 1143 1144 KASSERT(!cpu_softintr_p()); 1145 KASSERT(inph != NULL); 1146 KASSERT(inph_locked(inph)); 1147 KASSERT(request != NULL); 1148 1149 if (len < sizeof(*xpl)) 1150 return EINVAL; 1151 xpl = (const struct sadb_x_policy *)request; 1152 1153 KASSERT(inph->inph_sp != NULL); 1154 1155 /* select direction */ 1156 switch (xpl->sadb_x_policy_dir) { 1157 case IPSEC_DIR_INBOUND: 1158 policy = &inph->inph_sp->sp_in; 1159 break; 1160 case IPSEC_DIR_OUTBOUND: 1161 policy = &inph->inph_sp->sp_out; 1162 break; 1163 default: 1164 IPSECLOG(LOG_ERR, "invalid direction=%u\n", 1165 xpl->sadb_x_policy_dir); 1166 return EINVAL; 1167 } 1168 1169 /* sanity check. */ 1170 if (policy == NULL || *policy == NULL) 1171 return EINVAL; 1172 1173 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DUMP)) { 1174 kdebug_sadb_xpolicy("set passed policy", request); 1175 } 1176 1177 /* check policy type */ 1178 /* ipsec_set_policy() accepts IPSEC, ENTRUST and BYPASS. */ 1179 if (xpl->sadb_x_policy_type == IPSEC_POLICY_DISCARD || 1180 xpl->sadb_x_policy_type == IPSEC_POLICY_NONE) 1181 return EINVAL; 1182 1183 /* check privileged socket */ 1184 if (xpl->sadb_x_policy_type == IPSEC_POLICY_BYPASS) { 1185 error = kauth_authorize_network(cred, KAUTH_NETWORK_IPSEC, 1186 KAUTH_REQ_NETWORK_IPSEC_BYPASS, NULL, NULL, NULL); 1187 if (error) 1188 return error; 1189 } 1190 1191 /* allocation new SP entry */ 1192 if ((newsp = key_msg2sp(xpl, len, &error)) == NULL) 1193 return error; 1194 1195 key_init_sp(newsp); 1196 newsp->created = time_uptime; 1197 /* Insert the global list for SPs for sockets */ 1198 key_socksplist_add(newsp); 1199 1200 /* clear old SP and set new SP */ 1201 oldsp = *policy; 1202 *policy = newsp; 1203 ipsec_destroy_policy(oldsp); 1204 1205 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DUMP)) { 1206 printf("%s: new policy\n", __func__); 1207 kdebug_secpolicy(newsp); 1208 } 1209 1210 return 0; 1211 } 1212 1213 int 1214 ipsec_get_policy(void *inp, const void *request, size_t len, 1215 struct mbuf **mp) 1216 { 1217 struct inpcb_hdr *inph = (struct inpcb_hdr *)inp; 1218 const struct sadb_x_policy *xpl; 1219 struct secpolicy *policy; 1220 1221 /* sanity check. */ 1222 if (inph == NULL || request == NULL || mp == NULL) 1223 return EINVAL; 1224 KASSERT(inph->inph_sp != NULL); 1225 if (len < sizeof(*xpl)) 1226 return EINVAL; 1227 xpl = (const struct sadb_x_policy *)request; 1228 1229 /* select direction */ 1230 switch (xpl->sadb_x_policy_dir) { 1231 case IPSEC_DIR_INBOUND: 1232 policy = inph->inph_sp->sp_in; 1233 break; 1234 case IPSEC_DIR_OUTBOUND: 1235 policy = inph->inph_sp->sp_out; 1236 break; 1237 default: 1238 IPSECLOG(LOG_ERR, "invalid direction=%u\n", 1239 xpl->sadb_x_policy_dir); 1240 return EINVAL; 1241 } 1242 1243 if (policy == NULL) 1244 return EINVAL; 1245 1246 *mp = key_sp2msg(policy, M_NOWAIT); 1247 if (!*mp) { 1248 IPSECLOG(LOG_DEBUG, "No more memory.\n"); 1249 return ENOBUFS; 1250 } 1251 1252 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DUMP)) { 1253 kdebug_mbuf(__func__, *mp); 1254 } 1255 1256 return 0; 1257 } 1258 1259 int 1260 ipsec_delete_pcbpolicy(void *inp) 1261 { 1262 struct inpcb_hdr *inph = (struct inpcb_hdr *)inp; 1263 1264 KASSERT(inph != NULL); 1265 1266 if (inph->inph_sp == NULL) 1267 return 0; 1268 1269 if (inph->inph_sp->sp_in != NULL) 1270 ipsec_destroy_policy(inph->inph_sp->sp_in); 1271 1272 if (inph->inph_sp->sp_out != NULL) 1273 ipsec_destroy_policy(inph->inph_sp->sp_out); 1274 1275 ipsec_invalpcbcache(inph->inph_sp, IPSEC_DIR_ANY); 1276 1277 ipsec_delpcbpolicy(inph->inph_sp); 1278 inph->inph_sp = NULL; 1279 1280 return 0; 1281 } 1282 1283 /* 1284 * Return the current level (either IPSEC_LEVEL_USE or IPSEC_LEVEL_REQUIRE). 1285 */ 1286 u_int 1287 ipsec_get_reqlevel(const struct ipsecrequest *isr) 1288 { 1289 u_int level = 0; 1290 u_int esp_trans_deflev, esp_net_deflev; 1291 u_int ah_trans_deflev, ah_net_deflev; 1292 1293 KASSERT(isr != NULL); 1294 KASSERT(isr->sp != NULL); 1295 KASSERTMSG( 1296 isr->sp->spidx.src.sa.sa_family == isr->sp->spidx.dst.sa.sa_family, 1297 "af family mismatch, src %u, dst %u", 1298 isr->sp->spidx.src.sa.sa_family, isr->sp->spidx.dst.sa.sa_family); 1299 1300 /* XXX note that we have ipseclog() expanded here - code sync issue */ 1301 #define IPSEC_CHECK_DEFAULT(lev) \ 1302 (((lev) != IPSEC_LEVEL_USE && (lev) != IPSEC_LEVEL_REQUIRE \ 1303 && (lev) != IPSEC_LEVEL_UNIQUE) ? \ 1304 (ipsec_debug ? log(LOG_INFO, "fixed system default level " #lev \ 1305 ":%d->%d\n", (lev), IPSEC_LEVEL_REQUIRE) : (void)0), \ 1306 (lev) = IPSEC_LEVEL_REQUIRE, (lev) \ 1307 : (lev)) 1308 1309 /* set default level */ 1310 switch (((struct sockaddr *)&isr->sp->spidx.src)->sa_family) { 1311 #ifdef INET 1312 case AF_INET: 1313 esp_trans_deflev = IPSEC_CHECK_DEFAULT(ip4_esp_trans_deflev); 1314 esp_net_deflev = IPSEC_CHECK_DEFAULT(ip4_esp_net_deflev); 1315 ah_trans_deflev = IPSEC_CHECK_DEFAULT(ip4_ah_trans_deflev); 1316 ah_net_deflev = IPSEC_CHECK_DEFAULT(ip4_ah_net_deflev); 1317 break; 1318 #endif 1319 #ifdef INET6 1320 case AF_INET6: 1321 esp_trans_deflev = IPSEC_CHECK_DEFAULT(ip6_esp_trans_deflev); 1322 esp_net_deflev = IPSEC_CHECK_DEFAULT(ip6_esp_net_deflev); 1323 ah_trans_deflev = IPSEC_CHECK_DEFAULT(ip6_ah_trans_deflev); 1324 ah_net_deflev = IPSEC_CHECK_DEFAULT(ip6_ah_net_deflev); 1325 break; 1326 #endif 1327 default: 1328 panic("%s: unknown af %u", __func__, 1329 isr->sp->spidx.src.sa.sa_family); 1330 } 1331 1332 #undef IPSEC_CHECK_DEFAULT 1333 1334 /* set level */ 1335 switch (isr->level) { 1336 case IPSEC_LEVEL_DEFAULT: 1337 switch (isr->saidx.proto) { 1338 case IPPROTO_ESP: 1339 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) 1340 level = esp_net_deflev; 1341 else 1342 level = esp_trans_deflev; 1343 break; 1344 case IPPROTO_AH: 1345 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) 1346 level = ah_net_deflev; 1347 else 1348 level = ah_trans_deflev; 1349 break; 1350 case IPPROTO_IPCOMP: 1351 /* 1352 * we don't really care, as IPcomp document says that 1353 * we shouldn't compress small packets 1354 */ 1355 level = IPSEC_LEVEL_USE; 1356 break; 1357 default: 1358 panic("%s: Illegal protocol defined %u", __func__, 1359 isr->saidx.proto); 1360 } 1361 break; 1362 1363 case IPSEC_LEVEL_USE: 1364 case IPSEC_LEVEL_REQUIRE: 1365 level = isr->level; 1366 break; 1367 case IPSEC_LEVEL_UNIQUE: 1368 level = IPSEC_LEVEL_REQUIRE; 1369 break; 1370 1371 default: 1372 panic("%s: Illegal IPsec level %u", __func__, isr->level); 1373 } 1374 1375 return level; 1376 } 1377 1378 /* 1379 * Check security policy requirements against the actual packet contents. 1380 * 1381 * If the SP requires an IPsec packet, and the packet was neither AH nor ESP, 1382 * then kick it. 1383 */ 1384 static int 1385 ipsec_sp_reject(const struct secpolicy *sp, const struct mbuf *m) 1386 { 1387 struct ipsecrequest *isr; 1388 1389 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DATA)) { 1390 printf("%s: using SP\n", __func__); 1391 kdebug_secpolicy(sp); 1392 } 1393 1394 /* check policy */ 1395 switch (sp->policy) { 1396 case IPSEC_POLICY_DISCARD: 1397 return 1; 1398 case IPSEC_POLICY_BYPASS: 1399 case IPSEC_POLICY_NONE: 1400 return 0; 1401 } 1402 1403 KASSERTMSG(sp->policy == IPSEC_POLICY_IPSEC, 1404 "invalid policy %u", sp->policy); 1405 1406 /* XXX should compare policy against ipsec header history */ 1407 1408 for (isr = sp->req; isr != NULL; isr = isr->next) { 1409 if (ipsec_get_reqlevel(isr) != IPSEC_LEVEL_REQUIRE) 1410 continue; 1411 switch (isr->saidx.proto) { 1412 case IPPROTO_ESP: 1413 if ((m->m_flags & M_DECRYPTED) == 0) { 1414 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 1415 "ESP m_flags:%x\n", m->m_flags); 1416 return 1; 1417 } 1418 break; 1419 case IPPROTO_AH: 1420 if ((m->m_flags & M_AUTHIPHDR) == 0) { 1421 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 1422 "AH m_flags:%x\n", m->m_flags); 1423 return 1; 1424 } 1425 break; 1426 case IPPROTO_IPCOMP: 1427 /* 1428 * We don't really care, as IPcomp document 1429 * says that we shouldn't compress small 1430 * packets, IPComp policy should always be 1431 * treated as being in "use" level. 1432 */ 1433 break; 1434 } 1435 } 1436 1437 return 0; 1438 } 1439 1440 /* 1441 * Check security policy requirements. 1442 */ 1443 int 1444 ipsec_in_reject(struct mbuf *m, void *inp) 1445 { 1446 struct inpcb_hdr *inph = (struct inpcb_hdr *)inp; 1447 struct secpolicy *sp; 1448 int error; 1449 int result; 1450 1451 KASSERT(m != NULL); 1452 1453 if (inph == NULL) 1454 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND, 1455 IP_FORWARDING, &error); 1456 else 1457 sp = ipsec_getpolicybysock(m, IPSEC_DIR_INBOUND, 1458 inph, &error); 1459 1460 if (sp != NULL) { 1461 result = ipsec_sp_reject(sp, m); 1462 if (result) 1463 IPSEC_STATINC(IPSEC_STAT_IN_POLVIO); 1464 KEY_SP_UNREF(&sp); 1465 } else { 1466 result = 0; 1467 } 1468 return result; 1469 } 1470 1471 /* 1472 * Compute the byte size to be occupied by the IPsec header. If it is 1473 * tunneled, it includes the size of outer IP header. 1474 */ 1475 static size_t 1476 ipsec_sp_hdrsiz(const struct secpolicy *sp, const struct mbuf *m) 1477 { 1478 struct ipsecrequest *isr; 1479 size_t siz; 1480 1481 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DATA)) { 1482 printf("%s: using SP\n", __func__); 1483 kdebug_secpolicy(sp); 1484 } 1485 1486 switch (sp->policy) { 1487 case IPSEC_POLICY_DISCARD: 1488 case IPSEC_POLICY_BYPASS: 1489 case IPSEC_POLICY_NONE: 1490 return 0; 1491 } 1492 1493 KASSERTMSG(sp->policy == IPSEC_POLICY_IPSEC, 1494 "invalid policy %u", sp->policy); 1495 1496 siz = 0; 1497 for (isr = sp->req; isr != NULL; isr = isr->next) { 1498 size_t clen = 0; 1499 struct secasvar *sav; 1500 1501 switch (isr->saidx.proto) { 1502 case IPPROTO_ESP: 1503 sav = ipsec_lookup_sa(isr, m); 1504 if (sav != NULL) { 1505 clen = esp_hdrsiz(sav); 1506 KEY_SA_UNREF(&sav); 1507 } else 1508 clen = esp_hdrsiz(NULL); 1509 break; 1510 case IPPROTO_AH: 1511 sav = ipsec_lookup_sa(isr, m); 1512 if (sav != NULL) { 1513 clen = ah_hdrsiz(sav); 1514 KEY_SA_UNREF(&sav); 1515 } else 1516 clen = ah_hdrsiz(NULL); 1517 break; 1518 case IPPROTO_IPCOMP: 1519 clen = sizeof(struct ipcomp); 1520 break; 1521 } 1522 1523 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) { 1524 switch (isr->saidx.dst.sa.sa_family) { 1525 case AF_INET: 1526 clen += sizeof(struct ip); 1527 break; 1528 #ifdef INET6 1529 case AF_INET6: 1530 clen += sizeof(struct ip6_hdr); 1531 break; 1532 #endif 1533 default: 1534 IPSECLOG(LOG_ERR, "unknown AF %d in " 1535 "IPsec tunnel SA\n", 1536 ((const struct sockaddr *)&isr->saidx.dst) 1537 ->sa_family); 1538 break; 1539 } 1540 } 1541 siz += clen; 1542 } 1543 1544 return siz; 1545 } 1546 1547 size_t 1548 ipsec_hdrsiz(struct mbuf *m, u_int dir, void *inp) 1549 { 1550 struct inpcb_hdr *inph = (struct inpcb_hdr *)inp; 1551 struct secpolicy *sp; 1552 int error; 1553 size_t size; 1554 1555 KASSERT(m != NULL); 1556 KASSERTMSG(inph == NULL || inph->inph_socket != NULL, 1557 "socket w/o inpcb"); 1558 1559 if (inph == NULL) 1560 sp = ipsec_getpolicybyaddr(m, dir, IP_FORWARDING, &error); 1561 else 1562 sp = ipsec_getpolicybysock(m, dir, inph, &error); 1563 1564 if (sp != NULL) { 1565 size = ipsec_sp_hdrsiz(sp, m); 1566 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DATA, "size:%zu.\n", size); 1567 KEY_SP_UNREF(&sp); 1568 } else { 1569 size = 0; 1570 } 1571 1572 return size; 1573 } 1574 1575 /* 1576 * Check the variable replay window. 1577 * ipsec_chkreplay() performs replay check before ICV verification. 1578 * ipsec_updatereplay() updates replay bitmap. This must be called after 1579 * ICV verification (it also performs replay check, which is usually done 1580 * beforehand). 1581 * 0 (zero) is returned if packet disallowed, 1 if packet permitted. 1582 * 1583 * based on RFC 2401. 1584 */ 1585 int 1586 ipsec_chkreplay(u_int32_t seq, const struct secasvar *sav) 1587 { 1588 const struct secreplay *replay; 1589 u_int32_t diff; 1590 int fr; 1591 u_int32_t wsizeb; /* constant: bits of window size */ 1592 int frlast; /* constant: last frame */ 1593 1594 KASSERT(sav != NULL); 1595 KASSERT(sav->replay != NULL); 1596 1597 replay = sav->replay; 1598 1599 if (replay->wsize == 0) 1600 return 1; /* no need to check replay. */ 1601 1602 /* constant */ 1603 frlast = replay->wsize - 1; 1604 wsizeb = replay->wsize << 3; 1605 1606 /* sequence number of 0 is invalid */ 1607 if (seq == 0) 1608 return 0; 1609 1610 /* first time is always okay */ 1611 if (replay->count == 0) 1612 return 1; 1613 1614 if (seq > replay->lastseq) { 1615 /* larger sequences are okay */ 1616 return 1; 1617 } else { 1618 /* seq is equal or less than lastseq. */ 1619 diff = replay->lastseq - seq; 1620 1621 /* over range to check, i.e. too old or wrapped */ 1622 if (diff >= wsizeb) 1623 return 0; 1624 1625 fr = frlast - diff / 8; 1626 1627 /* this packet already seen ? */ 1628 if ((replay->bitmap)[fr] & (1 << (diff % 8))) 1629 return 0; 1630 1631 /* out of order but good */ 1632 return 1; 1633 } 1634 } 1635 1636 /* 1637 * check replay counter whether to update or not. 1638 * OUT: 0: OK 1639 * 1: NG 1640 */ 1641 int 1642 ipsec_updatereplay(u_int32_t seq, const struct secasvar *sav) 1643 { 1644 struct secreplay *replay; 1645 u_int32_t diff; 1646 int fr; 1647 u_int32_t wsizeb; /* constant: bits of window size */ 1648 int frlast; /* constant: last frame */ 1649 1650 KASSERT(sav != NULL); 1651 KASSERT(sav->replay != NULL); 1652 1653 replay = sav->replay; 1654 1655 if (replay->wsize == 0) 1656 goto ok; /* no need to check replay. */ 1657 1658 /* constant */ 1659 frlast = replay->wsize - 1; 1660 wsizeb = replay->wsize << 3; 1661 1662 /* sequence number of 0 is invalid */ 1663 if (seq == 0) 1664 return 1; 1665 1666 /* first time */ 1667 if (replay->count == 0) { 1668 replay->lastseq = seq; 1669 memset(replay->bitmap, 0, replay->wsize); 1670 (replay->bitmap)[frlast] = 1; 1671 goto ok; 1672 } 1673 1674 if (seq > replay->lastseq) { 1675 /* seq is larger than lastseq. */ 1676 diff = seq - replay->lastseq; 1677 1678 /* new larger sequence number */ 1679 if (diff < wsizeb) { 1680 /* In window */ 1681 /* set bit for this packet */ 1682 vshiftl(replay->bitmap, diff, replay->wsize); 1683 (replay->bitmap)[frlast] |= 1; 1684 } else { 1685 /* this packet has a "way larger" */ 1686 memset(replay->bitmap, 0, replay->wsize); 1687 (replay->bitmap)[frlast] = 1; 1688 } 1689 replay->lastseq = seq; 1690 1691 /* larger is good */ 1692 } else { 1693 /* seq is equal or less than lastseq. */ 1694 diff = replay->lastseq - seq; 1695 1696 /* over range to check, i.e. too old or wrapped */ 1697 if (diff >= wsizeb) 1698 return 1; 1699 1700 fr = frlast - diff / 8; 1701 1702 /* this packet already seen ? */ 1703 if ((replay->bitmap)[fr] & (1 << (diff % 8))) 1704 return 1; 1705 1706 /* mark as seen */ 1707 (replay->bitmap)[fr] |= (1 << (diff % 8)); 1708 1709 /* out of order but good */ 1710 } 1711 1712 ok: 1713 if (replay->count == ~0) { 1714 char buf[IPSEC_LOGSASTRLEN]; 1715 1716 /* set overflow flag */ 1717 replay->overflow++; 1718 1719 /* don't increment, no more packets accepted */ 1720 if ((sav->flags & SADB_X_EXT_CYCSEQ) == 0) 1721 return 1; 1722 1723 IPSECLOG(LOG_WARNING, "replay counter made %d cycle. %s\n", 1724 replay->overflow, ipsec_logsastr(sav, buf, sizeof(buf))); 1725 } 1726 1727 replay->count++; 1728 1729 return 0; 1730 } 1731 1732 /* 1733 * shift variable length buffer to left. 1734 * IN: bitmap: pointer to the buffer 1735 * nbit: the number of to shift. 1736 * wsize: buffer size (bytes). 1737 */ 1738 static void 1739 vshiftl(unsigned char *bitmap, int nbit, int wsize) 1740 { 1741 int s, j, i; 1742 unsigned char over; 1743 1744 for (j = 0; j < nbit; j += 8) { 1745 s = (nbit - j < 8) ? (nbit - j): 8; 1746 bitmap[0] <<= s; 1747 for (i = 1; i < wsize; i++) { 1748 over = (bitmap[i] >> (8 - s)); 1749 bitmap[i] <<= s; 1750 bitmap[i-1] |= over; 1751 } 1752 } 1753 1754 return; 1755 } 1756 1757 /* Return a printable string for the address. */ 1758 const char * 1759 ipsec_address(const union sockaddr_union *sa, char *buf, size_t size) 1760 { 1761 switch (sa->sa.sa_family) { 1762 case AF_INET: 1763 in_print(buf, size, &sa->sin.sin_addr); 1764 return buf; 1765 #if INET6 1766 case AF_INET6: 1767 in6_print(buf, size, &sa->sin6.sin6_addr); 1768 return buf; 1769 #endif 1770 default: 1771 return "(unknown address family)"; 1772 } 1773 } 1774 1775 const char * 1776 ipsec_logsastr(const struct secasvar *sav, char *buf, size_t size) 1777 { 1778 const struct secasindex *saidx = &sav->sah->saidx; 1779 char sbuf[IPSEC_ADDRSTRLEN], dbuf[IPSEC_ADDRSTRLEN]; 1780 1781 KASSERTMSG(saidx->src.sa.sa_family == saidx->dst.sa.sa_family, 1782 "af family mismatch, src %u, dst %u", 1783 saidx->src.sa.sa_family, saidx->dst.sa.sa_family); 1784 1785 snprintf(buf, size, "SA(SPI=%u src=%s dst=%s)", 1786 (u_int32_t)ntohl(sav->spi), 1787 ipsec_address(&saidx->src, sbuf, sizeof(sbuf)), 1788 ipsec_address(&saidx->dst, dbuf, sizeof(dbuf))); 1789 1790 return buf; 1791 } 1792 1793 #ifdef INET6 1794 struct secpolicy * 1795 ipsec6_check_policy(struct mbuf *m, struct in6pcb *in6p, int flags, 1796 int *needipsecp, int *errorp) 1797 { 1798 struct secpolicy *sp = NULL; 1799 int s; 1800 int error = 0; 1801 int needipsec = 0; 1802 1803 if (ipsec_outdone(m)) { 1804 goto skippolicycheck; 1805 } 1806 s = splsoftnet(); 1807 if (in6p && ipsec_pcb_skip_ipsec(in6p->in6p_sp, IPSEC_DIR_OUTBOUND)) { 1808 splx(s); 1809 goto skippolicycheck; 1810 } 1811 sp = ipsec_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags, &error, in6p); 1812 splx(s); 1813 1814 /* 1815 * There are four return cases: 1816 * sp != NULL apply IPsec policy 1817 * sp == NULL, error == 0 no IPsec handling needed 1818 * sp == NULL, error == -EINVAL discard packet w/o error 1819 * sp == NULL, error != 0 discard packet, report error 1820 */ 1821 if (sp == NULL) { 1822 needipsec = 0; 1823 } else { 1824 needipsec = 1; 1825 } 1826 1827 skippolicycheck: 1828 *errorp = error; 1829 *needipsecp = needipsec; 1830 return sp; 1831 } 1832 #endif /* INET6 */ 1833 1834 /* 1835 * ----------------------------------------------------------------------------- 1836 */ 1837 1838 /* XXX this stuff doesn't belong here... */ 1839 1840 static struct xformsw *xforms = NULL; 1841 1842 /* 1843 * Register a transform; typically at system startup. 1844 */ 1845 void 1846 xform_register(struct xformsw *xsp) 1847 { 1848 xsp->xf_next = xforms; 1849 xforms = xsp; 1850 } 1851 1852 /* 1853 * Initialize transform support in an sav. 1854 */ 1855 int 1856 xform_init(struct secasvar *sav, int xftype) 1857 { 1858 struct xformsw *xsp; 1859 1860 if (sav->tdb_xform != NULL) /* previously initialized */ 1861 return 0; 1862 for (xsp = xforms; xsp; xsp = xsp->xf_next) 1863 if (xsp->xf_type == xftype) 1864 return (*xsp->xf_init)(sav, xsp); 1865 1866 IPSECLOG(LOG_DEBUG, "no match for xform type %d\n", xftype); 1867 return EINVAL; 1868 } 1869 1870 void 1871 nat_t_ports_get(struct mbuf *m, u_int16_t *dport, u_int16_t *sport) 1872 { 1873 struct m_tag *tag; 1874 1875 if ((tag = m_tag_find(m, PACKET_TAG_IPSEC_NAT_T_PORTS, NULL))) { 1876 *sport = ((u_int16_t *)(tag + 1))[0]; 1877 *dport = ((u_int16_t *)(tag + 1))[1]; 1878 } else 1879 *sport = *dport = 0; 1880 } 1881 1882 /* 1883 * XXXJRT This should be done as a protosw init call. 1884 */ 1885 void 1886 ipsec_attach(void) 1887 { 1888 1889 ipsec_output_init(); 1890 1891 ipsecstat_percpu = percpu_alloc(sizeof(uint64_t) * IPSEC_NSTATS); 1892 1893 sysctl_net_inet_ipsec_setup(NULL); 1894 #ifdef INET6 1895 sysctl_net_inet6_ipsec6_setup(NULL); 1896 #endif 1897 1898 ah_attach(); 1899 esp_attach(); 1900 ipcomp_attach(); 1901 ipe4_attach(); 1902 #ifdef TCP_SIGNATURE 1903 tcpsignature_attach(); 1904 #endif 1905 } 1906
Indexes created Tue Sep 30 11:09:46 GMT 2025