ipsec.c revision 1.151.2.1
1 /* $NetBSD: ipsec.c,v 1.151.2.1 2018/04/07 04:12:20 pgoyette Exp $ */ 2 /* $FreeBSD: src/sys/netipsec/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 1.151.2.1 2018/04/07 04:12:20 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 } 551 552 if (sp == NULL) /* no SP found, use system default */ 553 sp = KEY_GET_DEFAULT_SP(spidx.dst.sa.sa_family); 554 KASSERT(sp != NULL); 555 return sp; 556 } 557 558 static struct secpolicy * 559 ipsec_checkpolicy(struct mbuf *m, u_int dir, u_int flag, int *error, 560 void *inp) 561 { 562 struct secpolicy *sp; 563 564 *error = 0; 565 566 if (inp == NULL) { 567 sp = ipsec_getpolicybyaddr(m, dir, flag, error); 568 } else { 569 struct inpcb_hdr *inph = (struct inpcb_hdr *)inp; 570 KASSERT(inph->inph_socket != NULL); 571 sp = ipsec_getpolicybysock(m, dir, inph, error); 572 } 573 if (sp == NULL) { 574 KASSERTMSG(*error != 0, "getpolicy failed w/o error"); 575 IPSEC_STATINC(IPSEC_STAT_OUT_INVAL); 576 return NULL; 577 } 578 KASSERTMSG(*error == 0, "sp w/ error set to %u", *error); 579 580 switch (sp->policy) { 581 case IPSEC_POLICY_ENTRUST: 582 default: 583 printf("%s: invalid policy %u\n", __func__, sp->policy); 584 /* fall thru... */ 585 case IPSEC_POLICY_DISCARD: 586 IPSEC_STATINC(IPSEC_STAT_OUT_POLVIO); 587 *error = -EINVAL; /* packet is discarded by caller */ 588 break; 589 case IPSEC_POLICY_BYPASS: 590 case IPSEC_POLICY_NONE: 591 KEY_SP_UNREF(&sp); 592 sp = NULL; /* NB: force NULL result */ 593 break; 594 case IPSEC_POLICY_IPSEC: 595 KASSERT(sp->req != NULL); 596 break; 597 } 598 599 if (*error != 0) { 600 KEY_SP_UNREF(&sp); 601 sp = NULL; 602 IPSECLOG(LOG_DEBUG, "done, error %d\n", *error); 603 } 604 605 return sp; 606 } 607 608 int 609 ipsec4_output(struct mbuf *m, struct inpcb *inp, int flags, 610 u_long *mtu, bool *natt_frag, bool *done) 611 { 612 struct secpolicy *sp = NULL; 613 u_long _mtu = 0; 614 int error, s; 615 616 /* 617 * Check the security policy (SP) for the packet and, if required, 618 * do IPsec-related processing. There are two cases here; the first 619 * time a packet is sent through it will be untagged and handled by 620 * ipsec_checkpolicy(). If the packet is resubmitted to ip_output 621 * (e.g. after AH, ESP, etc. processing), there will be a tag to 622 * bypass the lookup and related policy checking. 623 */ 624 if (ipsec_outdone(m)) { 625 return 0; 626 } 627 s = splsoftnet(); 628 if (inp && ipsec_pcb_skip_ipsec(inp->inp_sp, IPSEC_DIR_OUTBOUND)) { 629 splx(s); 630 return 0; 631 } 632 sp = ipsec_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags, &error, inp); 633 634 /* 635 * There are four return cases: 636 * sp != NULL apply IPsec policy 637 * sp == NULL, error == 0 no IPsec handling needed 638 * sp == NULL, error == -EINVAL discard packet w/o error 639 * sp == NULL, error != 0 discard packet, report error 640 */ 641 if (sp == NULL) { 642 splx(s); 643 if (error) { 644 /* 645 * Hack: -EINVAL is used to signal that a packet 646 * should be silently discarded. This is typically 647 * because we asked key management for an SA and 648 * it was delayed (e.g. kicked up to IKE). 649 */ 650 if (error == -EINVAL) 651 error = 0; 652 m_freem(m); 653 *done = true; 654 return error; 655 } 656 /* No IPsec processing for this packet. */ 657 return 0; 658 } 659 660 /* 661 * Do delayed checksums now because we send before 662 * this is done in the normal processing path. 663 */ 664 if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 665 in_delayed_cksum(m); 666 m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 667 } 668 669 error = ipsec4_process_packet(m, sp->req, &_mtu); 670 if (error == 0 && _mtu != 0) { 671 /* 672 * NAT-T ESP fragmentation: do not do IPSec processing 673 * now, we will do it on each fragmented packet. 674 */ 675 *mtu = _mtu; 676 *natt_frag = true; 677 KEY_SP_UNREF(&sp); 678 splx(s); 679 return 0; 680 } 681 682 /* 683 * Preserve KAME behaviour: ENOENT can be returned 684 * when an SA acquire is in progress. Don't propagate 685 * this to user-level; it confuses applications. 686 * 687 * XXX this will go away when the SADB is redone. 688 */ 689 if (error == ENOENT) 690 error = 0; 691 KEY_SP_UNREF(&sp); 692 splx(s); 693 *done = true; 694 return error; 695 } 696 697 int 698 ipsec4_input(struct mbuf *m, int flags) 699 { 700 struct secpolicy *sp; 701 int error, s; 702 703 s = splsoftnet(); 704 error = ipsec_in_reject(m, NULL); 705 splx(s); 706 if (error) { 707 return EINVAL; 708 } 709 710 if (flags == 0) { 711 /* We are done. */ 712 return 0; 713 } 714 715 /* 716 * Peek at the outbound SP for this packet to determine if 717 * it is a Fast Forward candidate. 718 */ 719 s = splsoftnet(); 720 sp = ipsec_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags, &error, NULL); 721 if (sp != NULL) { 722 m->m_flags &= ~M_CANFASTFWD; 723 KEY_SP_UNREF(&sp); 724 } 725 splx(s); 726 return 0; 727 } 728 729 int 730 ipsec4_forward(struct mbuf *m, int *destmtu) 731 { 732 /* 733 * If the packet is routed over IPsec tunnel, tell the 734 * originator the tunnel MTU. 735 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz 736 * XXX quickhack!!! 737 */ 738 struct secpolicy *sp; 739 size_t ipsechdr; 740 int error; 741 742 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, IP_FORWARDING, 743 &error); 744 if (sp == NULL) { 745 return EINVAL; 746 } 747 748 /* Count IPsec header size. */ 749 ipsechdr = ipsec_sp_hdrsiz(sp, m); 750 751 /* 752 * Find the correct route for outer IPv4 header, compute tunnel MTU. 753 */ 754 if (sp->req) { 755 struct secasvar *sav; 756 757 sav = ipsec_lookup_sa(sp->req, m); 758 if (sav != NULL) { 759 struct route *ro; 760 struct rtentry *rt; 761 762 ro = &sav->sah->sa_route; 763 rt = rtcache_validate(ro); 764 if (rt && rt->rt_ifp) { 765 *destmtu = rt->rt_rmx.rmx_mtu ? 766 rt->rt_rmx.rmx_mtu : rt->rt_ifp->if_mtu; 767 *destmtu -= ipsechdr; 768 } 769 rtcache_unref(rt, ro); 770 KEY_SA_UNREF(&sav); 771 } 772 } 773 KEY_SP_UNREF(&sp); 774 return 0; 775 } 776 777 static int 778 ipsec_setspidx_inpcb(struct mbuf *m, void *pcb) 779 { 780 struct inpcb_hdr *inph = (struct inpcb_hdr *)pcb; 781 int error; 782 783 KASSERT(inph != NULL); 784 KASSERT(inph->inph_sp != NULL); 785 KASSERT(inph->inph_sp->sp_out != NULL); 786 KASSERT(inph->inph_sp->sp_in != NULL); 787 788 error = ipsec_setspidx(m, &inph->inph_sp->sp_in->spidx, 1); 789 if (error == 0) { 790 inph->inph_sp->sp_in->spidx.dir = IPSEC_DIR_INBOUND; 791 inph->inph_sp->sp_out->spidx = inph->inph_sp->sp_in->spidx; 792 inph->inph_sp->sp_out->spidx.dir = IPSEC_DIR_OUTBOUND; 793 } else { 794 memset(&inph->inph_sp->sp_in->spidx, 0, 795 sizeof(inph->inph_sp->sp_in->spidx)); 796 memset(&inph->inph_sp->sp_out->spidx, 0, 797 sizeof(inph->inph_sp->sp_out->spidx)); 798 } 799 return error; 800 } 801 802 /* 803 * configure security policy index (src/dst/proto/sport/dport) 804 * by looking at the content of mbuf. 805 * the caller is responsible for error recovery (like clearing up spidx). 806 */ 807 static int 808 ipsec_setspidx(struct mbuf *m, struct secpolicyindex *spidx, int needport) 809 { 810 struct ip *ip = NULL; 811 struct ip ipbuf; 812 u_int v; 813 struct mbuf *n; 814 int len; 815 int error; 816 817 KASSERT(m != NULL); 818 819 /* 820 * validate m->m_pkthdr.len. we see incorrect length if we 821 * mistakenly call this function with inconsistent mbuf chain 822 * (like 4.4BSD tcp/udp processing). XXX should we panic here? 823 */ 824 len = 0; 825 for (n = m; n; n = n->m_next) 826 len += n->m_len; 827 if (m->m_pkthdr.len != len) { 828 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 829 "total of m_len(%d) != pkthdr.len(%d), ignored.\n", 830 len, m->m_pkthdr.len); 831 KASSERTMSG(0, "impossible"); 832 return EINVAL; 833 } 834 835 if (m->m_pkthdr.len < sizeof(struct ip)) { 836 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 837 "pkthdr.len(%d) < sizeof(struct ip), ignored.\n", 838 m->m_pkthdr.len); 839 return EINVAL; 840 } 841 842 if (m->m_len >= sizeof(*ip)) { 843 ip = mtod(m, struct ip *); 844 } else { 845 m_copydata(m, 0, sizeof(ipbuf), &ipbuf); 846 ip = &ipbuf; 847 } 848 v = ip->ip_v; 849 switch (v) { 850 case 4: 851 error = ipsec4_setspidx_ipaddr(m, spidx); 852 if (error) 853 return error; 854 ipsec4_get_ulp(m, spidx, needport); 855 return 0; 856 #ifdef INET6 857 case 6: 858 if (m->m_pkthdr.len < sizeof(struct ip6_hdr)) { 859 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 860 "pkthdr.len(%d) < sizeof(struct ip6_hdr), " 861 "ignored.\n", m->m_pkthdr.len); 862 return EINVAL; 863 } 864 error = ipsec6_setspidx_ipaddr(m, spidx); 865 if (error) 866 return error; 867 ipsec6_get_ulp(m, spidx, needport); 868 return 0; 869 #endif 870 default: 871 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 872 "unknown IP version %u, ignored.\n", v); 873 return EINVAL; 874 } 875 } 876 877 static void 878 ipsec4_get_ulp(struct mbuf *m, struct secpolicyindex *spidx, int needport) 879 { 880 u_int8_t nxt; 881 int off; 882 883 KASSERT(m != NULL); 884 KASSERTMSG(m->m_pkthdr.len >= sizeof(struct ip), "packet too short"); 885 886 /* NB: ip_input() flips it into host endian XXX need more checking */ 887 if (m->m_len >= sizeof(struct ip)) { 888 struct ip *ip = mtod(m, struct ip *); 889 if (ip->ip_off & htons(IP_MF | IP_OFFMASK)) 890 goto done; 891 off = ip->ip_hl << 2; 892 nxt = ip->ip_p; 893 } else { 894 struct ip ih; 895 896 m_copydata(m, 0, sizeof(struct ip), &ih); 897 if (ih.ip_off & htons(IP_MF | IP_OFFMASK)) 898 goto done; 899 off = ih.ip_hl << 2; 900 nxt = ih.ip_p; 901 } 902 903 while (off < m->m_pkthdr.len) { 904 struct ip6_ext ip6e; 905 struct tcphdr th; 906 struct udphdr uh; 907 struct icmp icmph; 908 909 switch (nxt) { 910 case IPPROTO_TCP: 911 spidx->ul_proto = nxt; 912 if (!needport) 913 goto done_proto; 914 if (off + sizeof(struct tcphdr) > m->m_pkthdr.len) 915 goto done; 916 m_copydata(m, off, sizeof(th), &th); 917 spidx->src.sin.sin_port = th.th_sport; 918 spidx->dst.sin.sin_port = th.th_dport; 919 return; 920 case IPPROTO_UDP: 921 spidx->ul_proto = nxt; 922 if (!needport) 923 goto done_proto; 924 if (off + sizeof(struct udphdr) > m->m_pkthdr.len) 925 goto done; 926 m_copydata(m, off, sizeof(uh), &uh); 927 spidx->src.sin.sin_port = uh.uh_sport; 928 spidx->dst.sin.sin_port = uh.uh_dport; 929 return; 930 case IPPROTO_AH: 931 if (off + sizeof(ip6e) > m->m_pkthdr.len) 932 goto done; 933 /* XXX sigh, this works but is totally bogus */ 934 m_copydata(m, off, sizeof(ip6e), &ip6e); 935 off += (ip6e.ip6e_len + 2) << 2; 936 nxt = ip6e.ip6e_nxt; 937 break; 938 case IPPROTO_ICMP: 939 spidx->ul_proto = nxt; 940 if (off + sizeof(struct icmp) > m->m_pkthdr.len) 941 goto done; 942 m_copydata(m, off, sizeof(icmph), &icmph); 943 ((struct sockaddr_in *)&spidx->src)->sin_port = 944 htons((uint16_t)icmph.icmp_type); 945 ((struct sockaddr_in *)&spidx->dst)->sin_port = 946 htons((uint16_t)icmph.icmp_code); 947 return; 948 default: 949 /* XXX intermediate headers??? */ 950 spidx->ul_proto = nxt; 951 goto done_proto; 952 } 953 } 954 done: 955 spidx->ul_proto = IPSEC_ULPROTO_ANY; 956 done_proto: 957 spidx->src.sin.sin_port = IPSEC_PORT_ANY; 958 spidx->dst.sin.sin_port = IPSEC_PORT_ANY; 959 } 960 961 static int 962 ipsec4_setspidx_ipaddr(struct mbuf *m, struct secpolicyindex *spidx) 963 { 964 static const struct sockaddr_in template = { 965 sizeof(struct sockaddr_in), 966 AF_INET, 967 0, { 0 }, { 0, 0, 0, 0, 0, 0, 0, 0 } 968 }; 969 970 spidx->src.sin = template; 971 spidx->dst.sin = template; 972 973 if (m->m_len < sizeof(struct ip)) { 974 m_copydata(m, offsetof(struct ip, ip_src), 975 sizeof(struct in_addr), &spidx->src.sin.sin_addr); 976 m_copydata(m, offsetof(struct ip, ip_dst), 977 sizeof(struct in_addr), &spidx->dst.sin.sin_addr); 978 } else { 979 struct ip *ip = mtod(m, struct ip *); 980 spidx->src.sin.sin_addr = ip->ip_src; 981 spidx->dst.sin.sin_addr = ip->ip_dst; 982 } 983 984 spidx->prefs = sizeof(struct in_addr) << 3; 985 spidx->prefd = sizeof(struct in_addr) << 3; 986 987 return 0; 988 } 989 990 #ifdef INET6 991 static void 992 ipsec6_get_ulp(struct mbuf *m, struct secpolicyindex *spidx, int needport) 993 { 994 int off, nxt; 995 struct tcphdr th; 996 struct udphdr uh; 997 struct icmp6_hdr icmph; 998 999 KASSERT(m != NULL); 1000 1001 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DUMP)) { 1002 kdebug_mbuf(__func__, m); 1003 } 1004 1005 /* set default */ 1006 spidx->ul_proto = IPSEC_ULPROTO_ANY; 1007 ((struct sockaddr_in6 *)&spidx->src)->sin6_port = IPSEC_PORT_ANY; 1008 ((struct sockaddr_in6 *)&spidx->dst)->sin6_port = IPSEC_PORT_ANY; 1009 1010 nxt = -1; 1011 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt); 1012 if (off < 0 || m->m_pkthdr.len < off) 1013 return; 1014 1015 switch (nxt) { 1016 case IPPROTO_TCP: 1017 spidx->ul_proto = nxt; 1018 if (!needport) 1019 break; 1020 if (off + sizeof(struct tcphdr) > m->m_pkthdr.len) 1021 break; 1022 m_copydata(m, off, sizeof(th), &th); 1023 ((struct sockaddr_in6 *)&spidx->src)->sin6_port = th.th_sport; 1024 ((struct sockaddr_in6 *)&spidx->dst)->sin6_port = th.th_dport; 1025 break; 1026 case IPPROTO_UDP: 1027 spidx->ul_proto = nxt; 1028 if (!needport) 1029 break; 1030 if (off + sizeof(struct udphdr) > m->m_pkthdr.len) 1031 break; 1032 m_copydata(m, off, sizeof(uh), &uh); 1033 ((struct sockaddr_in6 *)&spidx->src)->sin6_port = uh.uh_sport; 1034 ((struct sockaddr_in6 *)&spidx->dst)->sin6_port = uh.uh_dport; 1035 break; 1036 case IPPROTO_ICMPV6: 1037 spidx->ul_proto = nxt; 1038 if (off + sizeof(struct icmp6_hdr) > m->m_pkthdr.len) 1039 break; 1040 m_copydata(m, off, sizeof(icmph), &icmph); 1041 ((struct sockaddr_in6 *)&spidx->src)->sin6_port = 1042 htons((uint16_t)icmph.icmp6_type); 1043 ((struct sockaddr_in6 *)&spidx->dst)->sin6_port = 1044 htons((uint16_t)icmph.icmp6_code); 1045 break; 1046 default: 1047 /* XXX intermediate headers??? */ 1048 spidx->ul_proto = nxt; 1049 break; 1050 } 1051 } 1052 1053 static int 1054 ipsec6_setspidx_ipaddr(struct mbuf *m, struct secpolicyindex *spidx) 1055 { 1056 struct ip6_hdr *ip6 = NULL; 1057 struct ip6_hdr ip6buf; 1058 struct sockaddr_in6 *sin6; 1059 1060 if (m->m_len >= sizeof(*ip6)) 1061 ip6 = mtod(m, struct ip6_hdr *); 1062 else { 1063 m_copydata(m, 0, sizeof(ip6buf), &ip6buf); 1064 ip6 = &ip6buf; 1065 } 1066 1067 sin6 = (struct sockaddr_in6 *)&spidx->src; 1068 memset(sin6, 0, sizeof(*sin6)); 1069 sin6->sin6_family = AF_INET6; 1070 sin6->sin6_len = sizeof(struct sockaddr_in6); 1071 memcpy(&sin6->sin6_addr, &ip6->ip6_src, sizeof(ip6->ip6_src)); 1072 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) { 1073 sin6->sin6_addr.s6_addr16[1] = 0; 1074 sin6->sin6_scope_id = ntohs(ip6->ip6_src.s6_addr16[1]); 1075 } 1076 spidx->prefs = sizeof(struct in6_addr) << 3; 1077 1078 sin6 = (struct sockaddr_in6 *)&spidx->dst; 1079 memset(sin6, 0, sizeof(*sin6)); 1080 sin6->sin6_family = AF_INET6; 1081 sin6->sin6_len = sizeof(struct sockaddr_in6); 1082 memcpy(&sin6->sin6_addr, &ip6->ip6_dst, sizeof(ip6->ip6_dst)); 1083 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) { 1084 sin6->sin6_addr.s6_addr16[1] = 0; 1085 sin6->sin6_scope_id = ntohs(ip6->ip6_dst.s6_addr16[1]); 1086 } 1087 spidx->prefd = sizeof(struct in6_addr) << 3; 1088 1089 return 0; 1090 } 1091 #endif 1092 1093 static void 1094 ipsec_delpcbpolicy(struct inpcbpolicy *p) 1095 { 1096 1097 kmem_intr_free(p, sizeof(*p)); 1098 } 1099 1100 /* initialize policy in PCB */ 1101 int 1102 ipsec_init_policy(struct socket *so, struct inpcbpolicy **policy) 1103 { 1104 struct inpcbpolicy *new; 1105 1106 KASSERT(so != NULL); 1107 KASSERT(policy != NULL); 1108 1109 new = kmem_intr_zalloc(sizeof(*new), KM_NOSLEEP); 1110 if (new == NULL) { 1111 IPSECLOG(LOG_DEBUG, "No more memory.\n"); 1112 return ENOBUFS; 1113 } 1114 1115 if (IPSEC_PRIVILEGED_SO(so)) 1116 new->priv = 1; 1117 else 1118 new->priv = 0; 1119 1120 /* 1121 * Set dummy SPs. Actual SPs will be allocated later if needed. 1122 */ 1123 new->sp_in = &ipsec_dummy_sp; 1124 new->sp_out = &ipsec_dummy_sp; 1125 1126 *policy = new; 1127 1128 return 0; 1129 } 1130 1131 static void 1132 ipsec_destroy_policy(struct secpolicy *sp) 1133 { 1134 1135 if (sp == &ipsec_dummy_sp) 1136 ; /* It's dummy. No need to free it. */ 1137 else { 1138 /* 1139 * We cannot destroy here because it can be called in 1140 * softint. So mark the SP as DEAD and let the timer 1141 * destroy it. See key_timehandler_spd. 1142 */ 1143 sp->state = IPSEC_SPSTATE_DEAD; 1144 } 1145 } 1146 1147 int 1148 ipsec_set_policy(void *inp, int optname, const void *request, size_t len, 1149 kauth_cred_t cred) 1150 { 1151 struct inpcb_hdr *inph = (struct inpcb_hdr *)inp; 1152 const struct sadb_x_policy *xpl; 1153 struct secpolicy *newsp, *oldsp; 1154 struct secpolicy **policy; 1155 int error; 1156 1157 KASSERT(!cpu_softintr_p()); 1158 KASSERT(inph != NULL); 1159 KASSERT(inph_locked(inph)); 1160 KASSERT(request != NULL); 1161 1162 if (len < sizeof(*xpl)) 1163 return EINVAL; 1164 xpl = (const struct sadb_x_policy *)request; 1165 1166 KASSERT(inph->inph_sp != NULL); 1167 1168 /* select direction */ 1169 switch (xpl->sadb_x_policy_dir) { 1170 case IPSEC_DIR_INBOUND: 1171 policy = &inph->inph_sp->sp_in; 1172 break; 1173 case IPSEC_DIR_OUTBOUND: 1174 policy = &inph->inph_sp->sp_out; 1175 break; 1176 default: 1177 IPSECLOG(LOG_ERR, "invalid direction=%u\n", 1178 xpl->sadb_x_policy_dir); 1179 return EINVAL; 1180 } 1181 1182 /* sanity check. */ 1183 if (policy == NULL || *policy == NULL) 1184 return EINVAL; 1185 1186 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DUMP)) { 1187 kdebug_sadb_xpolicy("set passed policy", request); 1188 } 1189 1190 /* check policy type */ 1191 /* ipsec_set_policy() accepts IPSEC, ENTRUST and BYPASS. */ 1192 if (xpl->sadb_x_policy_type == IPSEC_POLICY_DISCARD || 1193 xpl->sadb_x_policy_type == IPSEC_POLICY_NONE) 1194 return EINVAL; 1195 1196 /* check privileged socket */ 1197 if (xpl->sadb_x_policy_type == IPSEC_POLICY_BYPASS) { 1198 error = kauth_authorize_network(cred, KAUTH_NETWORK_IPSEC, 1199 KAUTH_REQ_NETWORK_IPSEC_BYPASS, NULL, NULL, NULL); 1200 if (error) 1201 return error; 1202 } 1203 1204 /* allocation new SP entry */ 1205 if ((newsp = key_msg2sp(xpl, len, &error)) == NULL) 1206 return error; 1207 1208 key_init_sp(newsp); 1209 newsp->created = time_uptime; 1210 /* Insert the global list for SPs for sockets */ 1211 key_socksplist_add(newsp); 1212 1213 /* clear old SP and set new SP */ 1214 oldsp = *policy; 1215 *policy = newsp; 1216 ipsec_destroy_policy(oldsp); 1217 1218 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DUMP)) { 1219 printf("%s: new policy\n", __func__); 1220 kdebug_secpolicy(newsp); 1221 } 1222 1223 return 0; 1224 } 1225 1226 int 1227 ipsec_get_policy(void *inp, const void *request, size_t len, 1228 struct mbuf **mp) 1229 { 1230 struct inpcb_hdr *inph = (struct inpcb_hdr *)inp; 1231 const struct sadb_x_policy *xpl; 1232 struct secpolicy *policy; 1233 1234 /* sanity check. */ 1235 if (inph == NULL || request == NULL || mp == NULL) 1236 return EINVAL; 1237 KASSERT(inph->inph_sp != NULL); 1238 if (len < sizeof(*xpl)) 1239 return EINVAL; 1240 xpl = (const struct sadb_x_policy *)request; 1241 1242 /* select direction */ 1243 switch (xpl->sadb_x_policy_dir) { 1244 case IPSEC_DIR_INBOUND: 1245 policy = inph->inph_sp->sp_in; 1246 break; 1247 case IPSEC_DIR_OUTBOUND: 1248 policy = inph->inph_sp->sp_out; 1249 break; 1250 default: 1251 IPSECLOG(LOG_ERR, "invalid direction=%u\n", 1252 xpl->sadb_x_policy_dir); 1253 return EINVAL; 1254 } 1255 1256 if (policy == NULL) 1257 return EINVAL; 1258 1259 *mp = key_sp2msg(policy, M_NOWAIT); 1260 if (!*mp) { 1261 IPSECLOG(LOG_DEBUG, "No more memory.\n"); 1262 return ENOBUFS; 1263 } 1264 1265 (*mp)->m_type = MT_DATA; 1266 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DUMP)) { 1267 kdebug_mbuf(__func__, *mp); 1268 } 1269 1270 return 0; 1271 } 1272 1273 int 1274 ipsec_delete_pcbpolicy(void *inp) 1275 { 1276 struct inpcb_hdr *inph = (struct inpcb_hdr *)inp; 1277 1278 KASSERT(inph != NULL); 1279 1280 if (inph->inph_sp == NULL) 1281 return 0; 1282 1283 if (inph->inph_sp->sp_in != NULL) 1284 ipsec_destroy_policy(inph->inph_sp->sp_in); 1285 1286 if (inph->inph_sp->sp_out != NULL) 1287 ipsec_destroy_policy(inph->inph_sp->sp_out); 1288 1289 ipsec_invalpcbcache(inph->inph_sp, IPSEC_DIR_ANY); 1290 1291 ipsec_delpcbpolicy(inph->inph_sp); 1292 inph->inph_sp = NULL; 1293 1294 return 0; 1295 } 1296 1297 /* 1298 * Return the current level (either IPSEC_LEVEL_USE or IPSEC_LEVEL_REQUIRE). 1299 */ 1300 u_int 1301 ipsec_get_reqlevel(const struct ipsecrequest *isr) 1302 { 1303 u_int level = 0; 1304 u_int esp_trans_deflev, esp_net_deflev; 1305 u_int ah_trans_deflev, ah_net_deflev; 1306 1307 KASSERT(isr != NULL); 1308 KASSERT(isr->sp != NULL); 1309 KASSERTMSG( 1310 isr->sp->spidx.src.sa.sa_family == isr->sp->spidx.dst.sa.sa_family, 1311 "af family mismatch, src %u, dst %u", 1312 isr->sp->spidx.src.sa.sa_family, isr->sp->spidx.dst.sa.sa_family); 1313 1314 /* XXX note that we have ipseclog() expanded here - code sync issue */ 1315 #define IPSEC_CHECK_DEFAULT(lev) \ 1316 (((lev) != IPSEC_LEVEL_USE && (lev) != IPSEC_LEVEL_REQUIRE \ 1317 && (lev) != IPSEC_LEVEL_UNIQUE) ? \ 1318 (ipsec_debug ? log(LOG_INFO, "fixed system default level " #lev \ 1319 ":%d->%d\n", (lev), IPSEC_LEVEL_REQUIRE) : (void)0), \ 1320 (lev) = IPSEC_LEVEL_REQUIRE, (lev) \ 1321 : (lev)) 1322 1323 /* set default level */ 1324 switch (((struct sockaddr *)&isr->sp->spidx.src)->sa_family) { 1325 #ifdef INET 1326 case AF_INET: 1327 esp_trans_deflev = IPSEC_CHECK_DEFAULT(ip4_esp_trans_deflev); 1328 esp_net_deflev = IPSEC_CHECK_DEFAULT(ip4_esp_net_deflev); 1329 ah_trans_deflev = IPSEC_CHECK_DEFAULT(ip4_ah_trans_deflev); 1330 ah_net_deflev = IPSEC_CHECK_DEFAULT(ip4_ah_net_deflev); 1331 break; 1332 #endif 1333 #ifdef INET6 1334 case AF_INET6: 1335 esp_trans_deflev = IPSEC_CHECK_DEFAULT(ip6_esp_trans_deflev); 1336 esp_net_deflev = IPSEC_CHECK_DEFAULT(ip6_esp_net_deflev); 1337 ah_trans_deflev = IPSEC_CHECK_DEFAULT(ip6_ah_trans_deflev); 1338 ah_net_deflev = IPSEC_CHECK_DEFAULT(ip6_ah_net_deflev); 1339 break; 1340 #endif /* INET6 */ 1341 default: 1342 panic("%s: unknown af %u", __func__, 1343 isr->sp->spidx.src.sa.sa_family); 1344 } 1345 1346 #undef IPSEC_CHECK_DEFAULT 1347 1348 /* set level */ 1349 switch (isr->level) { 1350 case IPSEC_LEVEL_DEFAULT: 1351 switch (isr->saidx.proto) { 1352 case IPPROTO_ESP: 1353 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) 1354 level = esp_net_deflev; 1355 else 1356 level = esp_trans_deflev; 1357 break; 1358 case IPPROTO_AH: 1359 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) 1360 level = ah_net_deflev; 1361 else 1362 level = ah_trans_deflev; 1363 break; 1364 case IPPROTO_IPCOMP: 1365 /* 1366 * we don't really care, as IPcomp document says that 1367 * we shouldn't compress small packets 1368 */ 1369 level = IPSEC_LEVEL_USE; 1370 break; 1371 default: 1372 panic("%s: Illegal protocol defined %u", __func__, 1373 isr->saidx.proto); 1374 } 1375 break; 1376 1377 case IPSEC_LEVEL_USE: 1378 case IPSEC_LEVEL_REQUIRE: 1379 level = isr->level; 1380 break; 1381 case IPSEC_LEVEL_UNIQUE: 1382 level = IPSEC_LEVEL_REQUIRE; 1383 break; 1384 1385 default: 1386 panic("%s: Illegal IPsec level %u", __func__, isr->level); 1387 } 1388 1389 return level; 1390 } 1391 1392 /* 1393 * Check security policy requirements against the actual packet contents. 1394 * 1395 * If the SP requires an IPsec packet, and the packet was neither AH nor ESP, 1396 * then kick it. 1397 */ 1398 static int 1399 ipsec_sp_reject(const struct secpolicy *sp, const struct mbuf *m) 1400 { 1401 struct ipsecrequest *isr; 1402 1403 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DATA)) { 1404 printf("%s: using SP\n", __func__); 1405 kdebug_secpolicy(sp); 1406 } 1407 1408 /* check policy */ 1409 switch (sp->policy) { 1410 case IPSEC_POLICY_DISCARD: 1411 return 1; 1412 case IPSEC_POLICY_BYPASS: 1413 case IPSEC_POLICY_NONE: 1414 return 0; 1415 } 1416 1417 KASSERTMSG(sp->policy == IPSEC_POLICY_IPSEC, 1418 "invalid policy %u", sp->policy); 1419 1420 /* XXX should compare policy against ipsec header history */ 1421 1422 for (isr = sp->req; isr != NULL; isr = isr->next) { 1423 if (ipsec_get_reqlevel(isr) != IPSEC_LEVEL_REQUIRE) 1424 continue; 1425 switch (isr->saidx.proto) { 1426 case IPPROTO_ESP: 1427 if ((m->m_flags & M_DECRYPTED) == 0) { 1428 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 1429 "ESP m_flags:%x\n", m->m_flags); 1430 return 1; 1431 } 1432 break; 1433 case IPPROTO_AH: 1434 if ((m->m_flags & M_AUTHIPHDR) == 0) { 1435 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 1436 "AH m_flags:%x\n", m->m_flags); 1437 return 1; 1438 } 1439 break; 1440 case IPPROTO_IPCOMP: 1441 /* 1442 * We don't really care, as IPcomp document 1443 * says that we shouldn't compress small 1444 * packets, IPComp policy should always be 1445 * treated as being in "use" level. 1446 */ 1447 break; 1448 } 1449 } 1450 1451 return 0; 1452 } 1453 1454 /* 1455 * Check security policy requirements. 1456 */ 1457 int 1458 ipsec_in_reject(struct mbuf *m, void *inp) 1459 { 1460 struct inpcb_hdr *inph = (struct inpcb_hdr *)inp; 1461 struct secpolicy *sp; 1462 int error; 1463 int result; 1464 1465 KASSERT(m != NULL); 1466 1467 if (inph == NULL) 1468 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND, 1469 IP_FORWARDING, &error); 1470 else 1471 sp = ipsec_getpolicybysock(m, IPSEC_DIR_INBOUND, 1472 inph, &error); 1473 1474 if (sp != NULL) { 1475 result = ipsec_sp_reject(sp, m); 1476 if (result) 1477 IPSEC_STATINC(IPSEC_STAT_IN_POLVIO); 1478 KEY_SP_UNREF(&sp); 1479 } else { 1480 result = 0; 1481 } 1482 return result; 1483 } 1484 1485 /* 1486 * Compute the byte size to be occupied by the IPsec header. If it is 1487 * tunneled, it includes the size of outer IP header. 1488 */ 1489 static size_t 1490 ipsec_sp_hdrsiz(const struct secpolicy *sp, const struct mbuf *m) 1491 { 1492 struct ipsecrequest *isr; 1493 size_t siz; 1494 1495 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DATA)) { 1496 printf("%s: using SP\n", __func__); 1497 kdebug_secpolicy(sp); 1498 } 1499 1500 switch (sp->policy) { 1501 case IPSEC_POLICY_DISCARD: 1502 case IPSEC_POLICY_BYPASS: 1503 case IPSEC_POLICY_NONE: 1504 return 0; 1505 } 1506 1507 KASSERTMSG(sp->policy == IPSEC_POLICY_IPSEC, 1508 "invalid policy %u", sp->policy); 1509 1510 siz = 0; 1511 for (isr = sp->req; isr != NULL; isr = isr->next) { 1512 size_t clen = 0; 1513 struct secasvar *sav; 1514 1515 switch (isr->saidx.proto) { 1516 case IPPROTO_ESP: 1517 sav = ipsec_lookup_sa(isr, m); 1518 if (sav != NULL) { 1519 clen = esp_hdrsiz(sav); 1520 KEY_SA_UNREF(&sav); 1521 } else 1522 clen = esp_hdrsiz(NULL); 1523 break; 1524 case IPPROTO_AH: 1525 sav = ipsec_lookup_sa(isr, m); 1526 if (sav != NULL) { 1527 clen = ah_hdrsiz(sav); 1528 KEY_SA_UNREF(&sav); 1529 } else 1530 clen = ah_hdrsiz(NULL); 1531 break; 1532 case IPPROTO_IPCOMP: 1533 clen = sizeof(struct ipcomp); 1534 break; 1535 } 1536 1537 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) { 1538 switch (isr->saidx.dst.sa.sa_family) { 1539 case AF_INET: 1540 clen += sizeof(struct ip); 1541 break; 1542 #ifdef INET6 1543 case AF_INET6: 1544 clen += sizeof(struct ip6_hdr); 1545 break; 1546 #endif 1547 default: 1548 IPSECLOG(LOG_ERR, "unknown AF %d in " 1549 "IPsec tunnel SA\n", 1550 ((const struct sockaddr *)&isr->saidx.dst) 1551 ->sa_family); 1552 break; 1553 } 1554 } 1555 siz += clen; 1556 } 1557 1558 return siz; 1559 } 1560 1561 size_t 1562 ipsec_hdrsiz(struct mbuf *m, u_int dir, void *inp) 1563 { 1564 struct inpcb_hdr *inph = (struct inpcb_hdr *)inp; 1565 struct secpolicy *sp; 1566 int error; 1567 size_t size; 1568 1569 KASSERT(m != NULL); 1570 KASSERTMSG(inph == NULL || inph->inph_socket != NULL, 1571 "socket w/o inpcb"); 1572 1573 if (inph == NULL) 1574 sp = ipsec_getpolicybyaddr(m, dir, IP_FORWARDING, &error); 1575 else 1576 sp = ipsec_getpolicybysock(m, dir, inph, &error); 1577 1578 if (sp != NULL) { 1579 size = ipsec_sp_hdrsiz(sp, m); 1580 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DATA, "size:%zu.\n", size); 1581 KEY_SP_UNREF(&sp); 1582 } else { 1583 size = 0; 1584 } 1585 1586 return size; 1587 } 1588 1589 /* 1590 * Check the variable replay window. 1591 * ipsec_chkreplay() performs replay check before ICV verification. 1592 * ipsec_updatereplay() updates replay bitmap. This must be called after 1593 * ICV verification (it also performs replay check, which is usually done 1594 * beforehand). 1595 * 0 (zero) is returned if packet disallowed, 1 if packet permitted. 1596 * 1597 * based on RFC 2401. 1598 */ 1599 int 1600 ipsec_chkreplay(u_int32_t seq, const struct secasvar *sav) 1601 { 1602 const struct secreplay *replay; 1603 u_int32_t diff; 1604 int fr; 1605 u_int32_t wsizeb; /* constant: bits of window size */ 1606 int frlast; /* constant: last frame */ 1607 1608 IPSEC_SPLASSERT_SOFTNET(__func__); 1609 1610 KASSERT(sav != NULL); 1611 KASSERT(sav->replay != NULL); 1612 1613 replay = sav->replay; 1614 1615 if (replay->wsize == 0) 1616 return 1; /* no need to check replay. */ 1617 1618 /* constant */ 1619 frlast = replay->wsize - 1; 1620 wsizeb = replay->wsize << 3; 1621 1622 /* sequence number of 0 is invalid */ 1623 if (seq == 0) 1624 return 0; 1625 1626 /* first time is always okay */ 1627 if (replay->count == 0) 1628 return 1; 1629 1630 if (seq > replay->lastseq) { 1631 /* larger sequences are okay */ 1632 return 1; 1633 } else { 1634 /* seq is equal or less than lastseq. */ 1635 diff = replay->lastseq - seq; 1636 1637 /* over range to check, i.e. too old or wrapped */ 1638 if (diff >= wsizeb) 1639 return 0; 1640 1641 fr = frlast - diff / 8; 1642 1643 /* this packet already seen ? */ 1644 if ((replay->bitmap)[fr] & (1 << (diff % 8))) 1645 return 0; 1646 1647 /* out of order but good */ 1648 return 1; 1649 } 1650 } 1651 1652 /* 1653 * check replay counter whether to update or not. 1654 * OUT: 0: OK 1655 * 1: NG 1656 */ 1657 int 1658 ipsec_updatereplay(u_int32_t seq, const struct secasvar *sav) 1659 { 1660 struct secreplay *replay; 1661 u_int32_t diff; 1662 int fr; 1663 u_int32_t wsizeb; /* constant: bits of window size */ 1664 int frlast; /* constant: last frame */ 1665 1666 IPSEC_SPLASSERT_SOFTNET(__func__); 1667 1668 KASSERT(sav != NULL); 1669 KASSERT(sav->replay != NULL); 1670 1671 replay = sav->replay; 1672 1673 if (replay->wsize == 0) 1674 goto ok; /* no need to check replay. */ 1675 1676 /* constant */ 1677 frlast = replay->wsize - 1; 1678 wsizeb = replay->wsize << 3; 1679 1680 /* sequence number of 0 is invalid */ 1681 if (seq == 0) 1682 return 1; 1683 1684 /* first time */ 1685 if (replay->count == 0) { 1686 replay->lastseq = seq; 1687 memset(replay->bitmap, 0, replay->wsize); 1688 (replay->bitmap)[frlast] = 1; 1689 goto ok; 1690 } 1691 1692 if (seq > replay->lastseq) { 1693 /* seq is larger than lastseq. */ 1694 diff = seq - replay->lastseq; 1695 1696 /* new larger sequence number */ 1697 if (diff < wsizeb) { 1698 /* In window */ 1699 /* set bit for this packet */ 1700 vshiftl(replay->bitmap, diff, replay->wsize); 1701 (replay->bitmap)[frlast] |= 1; 1702 } else { 1703 /* this packet has a "way larger" */ 1704 memset(replay->bitmap, 0, replay->wsize); 1705 (replay->bitmap)[frlast] = 1; 1706 } 1707 replay->lastseq = seq; 1708 1709 /* larger is good */ 1710 } else { 1711 /* seq is equal or less than lastseq. */ 1712 diff = replay->lastseq - seq; 1713 1714 /* over range to check, i.e. too old or wrapped */ 1715 if (diff >= wsizeb) 1716 return 1; 1717 1718 fr = frlast - diff / 8; 1719 1720 /* this packet already seen ? */ 1721 if ((replay->bitmap)[fr] & (1 << (diff % 8))) 1722 return 1; 1723 1724 /* mark as seen */ 1725 (replay->bitmap)[fr] |= (1 << (diff % 8)); 1726 1727 /* out of order but good */ 1728 } 1729 1730 ok: 1731 if (replay->count == ~0) { 1732 char buf[IPSEC_LOGSASTRLEN]; 1733 1734 /* set overflow flag */ 1735 replay->overflow++; 1736 1737 /* don't increment, no more packets accepted */ 1738 if ((sav->flags & SADB_X_EXT_CYCSEQ) == 0) 1739 return 1; 1740 1741 IPSECLOG(LOG_WARNING, "replay counter made %d cycle. %s\n", 1742 replay->overflow, ipsec_logsastr(sav, buf, sizeof(buf))); 1743 } 1744 1745 replay->count++; 1746 1747 return 0; 1748 } 1749 1750 /* 1751 * shift variable length buffer to left. 1752 * IN: bitmap: pointer to the buffer 1753 * nbit: the number of to shift. 1754 * wsize: buffer size (bytes). 1755 */ 1756 static void 1757 vshiftl(unsigned char *bitmap, int nbit, int wsize) 1758 { 1759 int s, j, i; 1760 unsigned char over; 1761 1762 for (j = 0; j < nbit; j += 8) { 1763 s = (nbit - j < 8) ? (nbit - j): 8; 1764 bitmap[0] <<= s; 1765 for (i = 1; i < wsize; i++) { 1766 over = (bitmap[i] >> (8 - s)); 1767 bitmap[i] <<= s; 1768 bitmap[i-1] |= over; 1769 } 1770 } 1771 1772 return; 1773 } 1774 1775 /* Return a printable string for the address. */ 1776 const char * 1777 ipsec_address(const union sockaddr_union *sa, char *buf, size_t size) 1778 { 1779 switch (sa->sa.sa_family) { 1780 #if INET 1781 case AF_INET: 1782 in_print(buf, size, &sa->sin.sin_addr); 1783 return buf; 1784 #endif 1785 #if INET6 1786 case AF_INET6: 1787 in6_print(buf, size, &sa->sin6.sin6_addr); 1788 return buf; 1789 #endif 1790 default: 1791 return "(unknown address family)"; 1792 } 1793 } 1794 1795 const char * 1796 ipsec_logsastr(const struct secasvar *sav, char *buf, size_t size) 1797 { 1798 const struct secasindex *saidx = &sav->sah->saidx; 1799 char sbuf[IPSEC_ADDRSTRLEN], dbuf[IPSEC_ADDRSTRLEN]; 1800 1801 KASSERTMSG(saidx->src.sa.sa_family == saidx->dst.sa.sa_family, 1802 "af family mismatch, src %u, dst %u", 1803 saidx->src.sa.sa_family, saidx->dst.sa.sa_family); 1804 1805 snprintf(buf, size, "SA(SPI=%u src=%s dst=%s)", 1806 (u_int32_t)ntohl(sav->spi), 1807 ipsec_address(&saidx->src, sbuf, sizeof(sbuf)), 1808 ipsec_address(&saidx->dst, dbuf, sizeof(dbuf))); 1809 1810 return buf; 1811 } 1812 1813 void 1814 ipsec_dumpmbuf(struct mbuf *m) 1815 { 1816 int totlen; 1817 int i; 1818 u_char *p; 1819 1820 totlen = 0; 1821 printf("---\n"); 1822 while (m) { 1823 p = mtod(m, u_char *); 1824 for (i = 0; i < m->m_len; i++) { 1825 printf("%02x ", p[i]); 1826 totlen++; 1827 if (totlen % 16 == 0) 1828 printf("\n"); 1829 } 1830 m = m->m_next; 1831 } 1832 if (totlen % 16 != 0) 1833 printf("\n"); 1834 printf("---\n"); 1835 } 1836 1837 #ifdef INET6 1838 struct secpolicy * 1839 ipsec6_check_policy(struct mbuf *m, struct in6pcb *in6p, int flags, 1840 int *needipsecp, int *errorp) 1841 { 1842 struct secpolicy *sp = NULL; 1843 int s; 1844 int error = 0; 1845 int needipsec = 0; 1846 1847 if (ipsec_outdone(m)) { 1848 goto skippolicycheck; 1849 } 1850 s = splsoftnet(); 1851 if (in6p && ipsec_pcb_skip_ipsec(in6p->in6p_sp, IPSEC_DIR_OUTBOUND)) { 1852 splx(s); 1853 goto skippolicycheck; 1854 } 1855 sp = ipsec_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags, &error, in6p); 1856 splx(s); 1857 1858 /* 1859 * There are four return cases: 1860 * sp != NULL apply IPsec policy 1861 * sp == NULL, error == 0 no IPsec handling needed 1862 * sp == NULL, error == -EINVAL discard packet w/o error 1863 * sp == NULL, error != 0 discard packet, report error 1864 */ 1865 if (sp == NULL) { 1866 needipsec = 0; 1867 } else { 1868 needipsec = 1; 1869 } 1870 1871 skippolicycheck: 1872 *errorp = error; 1873 *needipsecp = needipsec; 1874 return sp; 1875 } 1876 1877 int 1878 ipsec6_input(struct mbuf *m) 1879 { 1880 int s, error; 1881 1882 s = splsoftnet(); 1883 error = ipsec_in_reject(m, NULL); 1884 splx(s); 1885 if (error) { 1886 return EINVAL; 1887 } 1888 1889 return 0; 1890 } 1891 #endif /* INET6 */ 1892 1893 /* 1894 * ----------------------------------------------------------------------------- 1895 */ 1896 1897 /* XXX this stuff doesn't belong here... */ 1898 1899 static struct xformsw *xforms = NULL; 1900 1901 /* 1902 * Register a transform; typically at system startup. 1903 */ 1904 void 1905 xform_register(struct xformsw *xsp) 1906 { 1907 xsp->xf_next = xforms; 1908 xforms = xsp; 1909 } 1910 1911 /* 1912 * Initialize transform support in an sav. 1913 */ 1914 int 1915 xform_init(struct secasvar *sav, int xftype) 1916 { 1917 struct xformsw *xsp; 1918 1919 if (sav->tdb_xform != NULL) /* previously initialized */ 1920 return 0; 1921 for (xsp = xforms; xsp; xsp = xsp->xf_next) 1922 if (xsp->xf_type == xftype) 1923 return (*xsp->xf_init)(sav, xsp); 1924 1925 IPSECLOG(LOG_DEBUG, "no match for xform type %d\n", xftype); 1926 return EINVAL; 1927 } 1928 1929 void 1930 nat_t_ports_get(struct mbuf *m, u_int16_t *dport, u_int16_t *sport) 1931 { 1932 struct m_tag *tag; 1933 1934 if ((tag = m_tag_find(m, PACKET_TAG_IPSEC_NAT_T_PORTS, NULL))) { 1935 *sport = ((u_int16_t *)(tag + 1))[0]; 1936 *dport = ((u_int16_t *)(tag + 1))[1]; 1937 } else 1938 *sport = *dport = 0; 1939 } 1940 1941 /* 1942 * XXXJRT This should be done as a protosw init call. 1943 */ 1944 void 1945 ipsec_attach(void) 1946 { 1947 1948 ipsec_output_init(); 1949 1950 ipsecstat_percpu = percpu_alloc(sizeof(uint64_t) * IPSEC_NSTATS); 1951 1952 sysctl_net_inet_ipsec_setup(NULL); 1953 #ifdef INET6 1954 sysctl_net_inet6_ipsec6_setup(NULL); 1955 #endif 1956 1957 ah_attach(); 1958 esp_attach(); 1959 ipcomp_attach(); 1960 ipe4_attach(); 1961 #ifdef TCP_SIGNATURE 1962 tcpsignature_attach(); 1963 #endif 1964 } 1965
Indexes created Tue Sep 30 11:09:46 GMT 2025