ipsec.c revision 1.151.2.5
1 /* $NetBSD: ipsec.c,v 1.151.2.5 2018/07/28 04:38:11 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 1.151.2.5 2018/07/28 04:38:11 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 #include <netinet/in_offload.h> 85 #ifdef INET6 86 #include <netinet6/in6_pcb.h> 87 #include <netinet/icmp6.h> 88 #endif 89 90 #include <netipsec/ipsec.h> 91 #include <netipsec/ipsec_var.h> 92 #include <netipsec/ipsec_private.h> 93 #ifdef INET6 94 #include <netipsec/ipsec6.h> 95 #endif 96 #include <netipsec/ah_var.h> 97 #include <netipsec/esp_var.h> 98 #include <netipsec/ipcomp.h> /*XXX*/ 99 #include <netipsec/ipcomp_var.h> 100 101 #include <netipsec/key.h> 102 #include <netipsec/keydb.h> 103 #include <netipsec/key_debug.h> 104 105 #include <netipsec/xform.h> 106 107 int ipsec_used = 0; 108 int ipsec_enabled = 1; 109 110 #ifdef IPSEC_DEBUG 111 int ipsec_debug = 1; 112 113 /* 114 * When set to 1, IPsec will send packets with the same sequence number. 115 * This allows to verify if the other side has proper replay attacks detection. 116 */ 117 int ipsec_replay = 0; 118 119 /* 120 * When set 1, IPsec will send packets with corrupted HMAC. 121 * This allows to verify if the other side properly detects modified packets. 122 */ 123 int ipsec_integrity = 0; 124 #else 125 int ipsec_debug = 0; 126 #endif 127 128 percpu_t *ipsecstat_percpu; 129 130 int ip4_ah_offsetmask = 0; /* maybe IP_DF? */ 131 int ip4_ipsec_dfbit = 2; /* DF bit on encap. 0: clear 1: set 2: copy */ 132 int ip4_esp_trans_deflev = IPSEC_LEVEL_USE; 133 int ip4_esp_net_deflev = IPSEC_LEVEL_USE; 134 int ip4_ah_trans_deflev = IPSEC_LEVEL_USE; 135 int ip4_ah_net_deflev = IPSEC_LEVEL_USE; 136 struct secpolicy ip4_def_policy; 137 int ip4_ipsec_ecn = 0; /* ECN ignore(-1)/forbidden(0)/allowed(1) */ 138 139 u_int ipsec_spdgen = 1; /* SPD generation # */ 140 141 static struct secpolicy ipsec_dummy_sp __read_mostly = { 142 .state = IPSEC_SPSTATE_ALIVE, 143 /* If ENTRUST, the dummy SP never be used. See ipsec_getpolicybysock. */ 144 .policy = IPSEC_POLICY_ENTRUST, 145 }; 146 147 static struct secpolicy *ipsec_checkpcbcache(struct mbuf *, 148 struct inpcbpolicy *, int); 149 static int ipsec_fillpcbcache(struct inpcbpolicy *, struct mbuf *, 150 struct secpolicy *, int); 151 static int ipsec_invalpcbcache(struct inpcbpolicy *, int); 152 153 /* 154 * Crypto support requirements: 155 * 156 * 1 require hardware support 157 * -1 require software support 158 * 0 take anything 159 */ 160 int crypto_support = 0; 161 162 static struct secpolicy *ipsec_getpolicybysock(struct mbuf *, u_int, 163 struct inpcb_hdr *, int *); 164 165 #ifdef INET6 166 int ip6_esp_trans_deflev = IPSEC_LEVEL_USE; 167 int ip6_esp_net_deflev = IPSEC_LEVEL_USE; 168 int ip6_ah_trans_deflev = IPSEC_LEVEL_USE; 169 int ip6_ah_net_deflev = IPSEC_LEVEL_USE; 170 struct secpolicy ip6_def_policy; 171 int ip6_ipsec_ecn = 0; /* ECN ignore(-1)/forbidden(0)/allowed(1) */ 172 #endif 173 174 static int ipsec_setspidx_inpcb(struct mbuf *, void *); 175 static int ipsec_setspidx(struct mbuf *, struct secpolicyindex *, int); 176 static void ipsec4_get_ulp(struct mbuf *m, struct secpolicyindex *, int); 177 static int ipsec4_setspidx_ipaddr(struct mbuf *, struct secpolicyindex *); 178 #ifdef INET6 179 static void ipsec6_get_ulp(struct mbuf *m, struct secpolicyindex *, int); 180 static int ipsec6_setspidx_ipaddr(struct mbuf *, struct secpolicyindex *); 181 #endif 182 static void ipsec_delpcbpolicy(struct inpcbpolicy *); 183 static void ipsec_destroy_policy(struct secpolicy *); 184 static int ipsec_sp_reject(const struct secpolicy *, const struct mbuf *); 185 static void vshiftl(unsigned char *, int, int); 186 static size_t ipsec_sp_hdrsiz(const struct secpolicy *, const struct mbuf *); 187 188 /* 189 * Try to validate and use cached policy on a PCB. 190 */ 191 static struct secpolicy * 192 ipsec_checkpcbcache(struct mbuf *m, struct inpcbpolicy *pcbsp, int dir) 193 { 194 struct secpolicyindex spidx; 195 struct secpolicy *sp = NULL; 196 int s; 197 198 KASSERT(IPSEC_DIR_IS_VALID(dir)); 199 KASSERT(pcbsp != NULL); 200 KASSERT(dir < __arraycount(pcbsp->sp_cache)); 201 KASSERT(inph_locked(pcbsp->sp_inph)); 202 203 /* 204 * Checking the generation and sp->state and taking a reference to an SP 205 * must be in a critical section of pserialize. See key_unlink_sp. 206 */ 207 s = pserialize_read_enter(); 208 /* SPD table change invalidate all the caches. */ 209 if (ipsec_spdgen != pcbsp->sp_cache[dir].cachegen) { 210 ipsec_invalpcbcache(pcbsp, dir); 211 goto out; 212 } 213 sp = pcbsp->sp_cache[dir].cachesp; 214 if (sp == NULL) 215 goto out; 216 if (sp->state != IPSEC_SPSTATE_ALIVE) { 217 sp = NULL; 218 ipsec_invalpcbcache(pcbsp, dir); 219 goto out; 220 } 221 if ((pcbsp->sp_cacheflags & IPSEC_PCBSP_CONNECTED) == 0) { 222 /* NB: assume ipsec_setspidx never sleep */ 223 if (ipsec_setspidx(m, &spidx, 1) != 0) { 224 sp = NULL; 225 goto out; 226 } 227 228 /* 229 * We have to make an exact match here since the cached rule 230 * might have lower priority than a rule that would otherwise 231 * have matched the packet. 232 */ 233 if (memcmp(&pcbsp->sp_cache[dir].cacheidx, &spidx, 234 sizeof(spidx))) { 235 sp = NULL; 236 goto out; 237 } 238 } else { 239 /* 240 * The pcb is connected, and the L4 code is sure that: 241 * - outgoing side uses inp_[lf]addr 242 * - incoming side looks up policy after inpcb lookup 243 * and address pair is know to be stable. We do not need 244 * to generate spidx again, nor check the address match again. 245 * 246 * For IPv4/v6 SOCK_STREAM sockets, this assumptions holds 247 * and there are calls to ipsec_pcbconn() from in_pcbconnect(). 248 */ 249 } 250 251 sp->lastused = time_second; 252 KEY_SP_REF(sp); 253 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_STAMP, 254 "DP cause refcnt++:%d SP:%p\n", 255 key_sp_refcnt(sp), pcbsp->sp_cache[dir].cachesp); 256 out: 257 pserialize_read_exit(s); 258 return sp; 259 } 260 261 static int 262 ipsec_fillpcbcache(struct inpcbpolicy *pcbsp, struct mbuf *m, 263 struct secpolicy *sp, int dir) 264 { 265 266 KASSERT(IPSEC_DIR_IS_INOROUT(dir)); 267 KASSERT(dir < __arraycount(pcbsp->sp_cache)); 268 KASSERT(inph_locked(pcbsp->sp_inph)); 269 270 pcbsp->sp_cache[dir].cachesp = NULL; 271 pcbsp->sp_cache[dir].cachehint = IPSEC_PCBHINT_UNKNOWN; 272 if (ipsec_setspidx(m, &pcbsp->sp_cache[dir].cacheidx, 1) != 0) { 273 return EINVAL; 274 } 275 pcbsp->sp_cache[dir].cachesp = sp; 276 if (pcbsp->sp_cache[dir].cachesp) { 277 /* 278 * If the PCB is connected, we can remember a hint to 279 * possibly short-circuit IPsec processing in other places. 280 */ 281 if (pcbsp->sp_cacheflags & IPSEC_PCBSP_CONNECTED) { 282 switch (pcbsp->sp_cache[dir].cachesp->policy) { 283 case IPSEC_POLICY_NONE: 284 case IPSEC_POLICY_BYPASS: 285 pcbsp->sp_cache[dir].cachehint = 286 IPSEC_PCBHINT_NO; 287 break; 288 default: 289 pcbsp->sp_cache[dir].cachehint = 290 IPSEC_PCBHINT_YES; 291 } 292 } 293 } 294 pcbsp->sp_cache[dir].cachegen = ipsec_spdgen; 295 296 return 0; 297 } 298 299 static int 300 ipsec_invalpcbcache(struct inpcbpolicy *pcbsp, int dir) 301 { 302 int i; 303 304 KASSERT(inph_locked(pcbsp->sp_inph)); 305 306 for (i = IPSEC_DIR_INBOUND; i <= IPSEC_DIR_OUTBOUND; i++) { 307 if (dir != IPSEC_DIR_ANY && i != dir) 308 continue; 309 pcbsp->sp_cache[i].cachesp = NULL; 310 pcbsp->sp_cache[i].cachehint = IPSEC_PCBHINT_UNKNOWN; 311 pcbsp->sp_cache[i].cachegen = 0; 312 memset(&pcbsp->sp_cache[i].cacheidx, 0, 313 sizeof(pcbsp->sp_cache[i].cacheidx)); 314 } 315 return 0; 316 } 317 318 void 319 ipsec_pcbconn(struct inpcbpolicy *pcbsp) 320 { 321 322 KASSERT(inph_locked(pcbsp->sp_inph)); 323 324 pcbsp->sp_cacheflags |= IPSEC_PCBSP_CONNECTED; 325 ipsec_invalpcbcache(pcbsp, IPSEC_DIR_ANY); 326 } 327 328 void 329 ipsec_pcbdisconn(struct inpcbpolicy *pcbsp) 330 { 331 332 KASSERT(inph_locked(pcbsp->sp_inph)); 333 334 pcbsp->sp_cacheflags &= ~IPSEC_PCBSP_CONNECTED; 335 ipsec_invalpcbcache(pcbsp, IPSEC_DIR_ANY); 336 } 337 338 void 339 ipsec_invalpcbcacheall(void) 340 { 341 342 if (ipsec_spdgen == UINT_MAX) 343 ipsec_spdgen = 1; 344 else 345 ipsec_spdgen++; 346 } 347 348 /* 349 * Return a held reference to the default SP. 350 */ 351 static struct secpolicy * 352 key_get_default_sp(int af, const char *where, int tag) 353 { 354 struct secpolicy *sp; 355 356 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_STAMP, "DP from %s:%u\n", where, tag); 357 358 switch(af) { 359 case AF_INET: 360 sp = &ip4_def_policy; 361 break; 362 #ifdef INET6 363 case AF_INET6: 364 sp = &ip6_def_policy; 365 break; 366 #endif 367 default: 368 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_STAMP, 369 "unexpected protocol family %u\n", af); 370 return NULL; 371 } 372 373 if (sp->policy != IPSEC_POLICY_DISCARD && 374 sp->policy != IPSEC_POLICY_NONE) { 375 IPSECLOG(LOG_INFO, "fixed system default policy: %d->%d\n", 376 sp->policy, IPSEC_POLICY_NONE); 377 sp->policy = IPSEC_POLICY_NONE; 378 } 379 KEY_SP_REF(sp); 380 381 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_STAMP, "DP returns SP:%p (%u)\n", 382 sp, key_sp_refcnt(sp)); 383 return sp; 384 } 385 386 #define KEY_GET_DEFAULT_SP(af) \ 387 key_get_default_sp((af), __func__, __LINE__) 388 389 /* 390 * For OUTBOUND packet having a socket. Searching SPD for packet, 391 * and return a pointer to SP. 392 * OUT: NULL: no appropriate SP found, the following value is set to error. 393 * 0 : bypass 394 * EACCES : discard packet. 395 * ENOENT : ipsec_acquire() in progress, maybe. 396 * others : error occurred. 397 * others: a pointer to SP 398 * 399 * NOTE: IPv6 mapped address concern is implemented here. 400 */ 401 static struct secpolicy * 402 ipsec_getpolicybysock(struct mbuf *m, u_int dir, struct inpcb_hdr *inph, 403 int *error) 404 { 405 struct inpcbpolicy *pcbsp = NULL; 406 struct secpolicy *currsp = NULL; /* policy on socket */ 407 struct secpolicy *sp; 408 int af; 409 410 KASSERT(m != NULL); 411 KASSERT(inph != NULL); 412 KASSERT(error != NULL); 413 KASSERTMSG(IPSEC_DIR_IS_INOROUT(dir), "invalid direction %u", dir); 414 415 KASSERT(inph->inph_socket != NULL); 416 KASSERT(inph_locked(inph)); 417 418 /* XXX FIXME inpcb/in6pcb vs socket*/ 419 af = inph->inph_af; 420 KASSERTMSG(af == AF_INET || af == AF_INET6, 421 "unexpected protocol family %u", af); 422 423 KASSERT(inph->inph_sp != NULL); 424 /* If we have a cached entry, and if it is still valid, use it. */ 425 IPSEC_STATINC(IPSEC_STAT_SPDCACHELOOKUP); 426 currsp = ipsec_checkpcbcache(m, inph->inph_sp, dir); 427 if (currsp) { 428 *error = 0; 429 return currsp; 430 } 431 IPSEC_STATINC(IPSEC_STAT_SPDCACHEMISS); 432 433 switch (af) { 434 case AF_INET: 435 #if defined(INET6) 436 case AF_INET6: 437 #endif 438 *error = ipsec_setspidx_inpcb(m, inph); 439 pcbsp = inph->inph_sp; 440 break; 441 default: 442 *error = EPFNOSUPPORT; 443 break; 444 } 445 if (*error) 446 return NULL; 447 448 KASSERT(pcbsp != NULL); 449 switch (dir) { 450 case IPSEC_DIR_INBOUND: 451 currsp = pcbsp->sp_in; 452 break; 453 case IPSEC_DIR_OUTBOUND: 454 currsp = pcbsp->sp_out; 455 break; 456 } 457 KASSERT(currsp != NULL); 458 459 if (pcbsp->priv) { /* when privileged socket */ 460 switch (currsp->policy) { 461 case IPSEC_POLICY_BYPASS: 462 case IPSEC_POLICY_IPSEC: 463 KEY_SP_REF(currsp); 464 sp = currsp; 465 break; 466 467 case IPSEC_POLICY_ENTRUST: 468 /* look for a policy in SPD */ 469 sp = KEY_LOOKUP_SP_BYSPIDX(&currsp->spidx, dir); 470 if (sp == NULL) /* no SP found */ 471 sp = KEY_GET_DEFAULT_SP(af); 472 break; 473 474 default: 475 IPSECLOG(LOG_ERR, "Invalid policy for PCB %d\n", 476 currsp->policy); 477 *error = EINVAL; 478 return NULL; 479 } 480 } else { /* unpriv, SPD has policy */ 481 sp = KEY_LOOKUP_SP_BYSPIDX(&currsp->spidx, dir); 482 if (sp == NULL) { /* no SP found */ 483 switch (currsp->policy) { 484 case IPSEC_POLICY_BYPASS: 485 IPSECLOG(LOG_ERR, "Illegal policy for " 486 "non-priviliged defined %d\n", 487 currsp->policy); 488 *error = EINVAL; 489 return NULL; 490 491 case IPSEC_POLICY_ENTRUST: 492 sp = KEY_GET_DEFAULT_SP(af); 493 break; 494 495 case IPSEC_POLICY_IPSEC: 496 KEY_SP_REF(currsp); 497 sp = currsp; 498 break; 499 500 default: 501 IPSECLOG(LOG_ERR, "Invalid policy for " 502 "PCB %d\n", currsp->policy); 503 *error = EINVAL; 504 return NULL; 505 } 506 } 507 } 508 KASSERTMSG(sp != NULL, "null SP (priv %u policy %u", pcbsp->priv, 509 currsp->policy); 510 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_STAMP, 511 "DP (priv %u policy %u) allocates SP:%p (refcnt %u)\n", 512 pcbsp->priv, currsp->policy, sp, key_sp_refcnt(sp)); 513 ipsec_fillpcbcache(pcbsp, m, sp, dir); 514 return sp; 515 } 516 517 /* 518 * For FORWARDING packet or OUTBOUND without a socket. Searching SPD for packet, 519 * and return a pointer to SP. 520 * OUT: positive: a pointer to the entry for security policy leaf matched. 521 * NULL: no appropriate SP found, the following value is set to error. 522 * 0 : bypass 523 * EACCES : discard packet. 524 * ENOENT : ipsec_acquire() in progress, maybe. 525 * others : error occurred. 526 */ 527 static struct secpolicy * 528 ipsec_getpolicybyaddr(struct mbuf *m, u_int dir, int flag, int *error) 529 { 530 struct secpolicyindex spidx; 531 struct secpolicy *sp; 532 533 KASSERT(m != NULL); 534 KASSERT(error != NULL); 535 KASSERTMSG(IPSEC_DIR_IS_INOROUT(dir), "invalid direction %u", dir); 536 537 sp = NULL; 538 539 /* Make an index to look for a policy. */ 540 *error = ipsec_setspidx(m, &spidx, (flag & IP_FORWARDING) ? 0 : 1); 541 if (*error != 0) { 542 IPSECLOG(LOG_DEBUG, "setpidx failed, dir %u flag %u\n", dir, flag); 543 memset(&spidx, 0, sizeof(spidx)); 544 return NULL; 545 } 546 547 spidx.dir = dir; 548 549 if (key_havesp(dir)) { 550 sp = KEY_LOOKUP_SP_BYSPIDX(&spidx, dir); 551 } 552 if (sp == NULL) { 553 /* no SP found, use system default */ 554 sp = KEY_GET_DEFAULT_SP(spidx.dst.sa.sa_family); 555 } 556 557 KASSERT(sp != NULL); 558 return sp; 559 } 560 561 static struct secpolicy * 562 ipsec_checkpolicy(struct mbuf *m, u_int dir, u_int flag, int *error, 563 void *inp) 564 { 565 struct secpolicy *sp; 566 567 *error = 0; 568 569 if (inp == NULL) { 570 sp = ipsec_getpolicybyaddr(m, dir, flag, error); 571 } else { 572 struct inpcb_hdr *inph = (struct inpcb_hdr *)inp; 573 KASSERT(inph->inph_socket != NULL); 574 sp = ipsec_getpolicybysock(m, dir, inph, error); 575 } 576 if (sp == NULL) { 577 KASSERTMSG(*error != 0, "getpolicy failed w/o error"); 578 IPSEC_STATINC(IPSEC_STAT_OUT_INVAL); 579 return NULL; 580 } 581 KASSERTMSG(*error == 0, "sp w/ error set to %u", *error); 582 583 switch (sp->policy) { 584 case IPSEC_POLICY_ENTRUST: 585 default: 586 printf("%s: invalid policy %u\n", __func__, sp->policy); 587 /* fall thru... */ 588 case IPSEC_POLICY_DISCARD: 589 IPSEC_STATINC(IPSEC_STAT_OUT_POLVIO); 590 *error = -EINVAL; /* packet is discarded by caller */ 591 break; 592 case IPSEC_POLICY_BYPASS: 593 case IPSEC_POLICY_NONE: 594 KEY_SP_UNREF(&sp); 595 sp = NULL; /* NB: force NULL result */ 596 break; 597 case IPSEC_POLICY_IPSEC: 598 KASSERT(sp->req != NULL); 599 break; 600 } 601 602 if (*error != 0) { 603 KEY_SP_UNREF(&sp); 604 sp = NULL; 605 IPSECLOG(LOG_DEBUG, "done, error %d\n", *error); 606 } 607 608 return sp; 609 } 610 611 int 612 ipsec4_output(struct mbuf *m, struct inpcb *inp, int flags, 613 u_long *mtu, bool *natt_frag, bool *done) 614 { 615 struct secpolicy *sp = NULL; 616 u_long _mtu = 0; 617 int error, s; 618 619 /* 620 * Check the security policy (SP) for the packet and, if required, 621 * do IPsec-related processing. There are two cases here; the first 622 * time a packet is sent through it will be untagged and handled by 623 * ipsec_checkpolicy(). If the packet is resubmitted to ip_output 624 * (e.g. after AH, ESP, etc. processing), there will be a tag to 625 * bypass the lookup and related policy checking. 626 */ 627 if (ipsec_outdone(m)) { 628 return 0; 629 } 630 s = splsoftnet(); 631 if (inp && ipsec_pcb_skip_ipsec(inp->inp_sp, IPSEC_DIR_OUTBOUND)) { 632 splx(s); 633 return 0; 634 } 635 sp = ipsec_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags, &error, inp); 636 637 /* 638 * There are four return cases: 639 * sp != NULL apply IPsec policy 640 * sp == NULL, error == 0 no IPsec handling needed 641 * sp == NULL, error == -EINVAL discard packet w/o error 642 * sp == NULL, error != 0 discard packet, report error 643 */ 644 if (sp == NULL) { 645 splx(s); 646 if (error) { 647 /* 648 * Hack: -EINVAL is used to signal that a packet 649 * should be silently discarded. This is typically 650 * because we asked key management for an SA and 651 * it was delayed (e.g. kicked up to IKE). 652 */ 653 if (error == -EINVAL) 654 error = 0; 655 m_freem(m); 656 *done = true; 657 return error; 658 } 659 /* No IPsec processing for this packet. */ 660 return 0; 661 } 662 663 /* 664 * Do delayed checksums now because we send before 665 * this is done in the normal processing path. 666 */ 667 if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 668 in_undefer_cksum_tcpudp(m); 669 m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 670 } 671 672 error = ipsec4_process_packet(m, sp->req, &_mtu); 673 if (error == 0 && _mtu != 0) { 674 /* 675 * NAT-T ESP fragmentation: do not do IPSec processing 676 * now, we will do it on each fragmented packet. 677 */ 678 *mtu = _mtu; 679 *natt_frag = true; 680 KEY_SP_UNREF(&sp); 681 splx(s); 682 return 0; 683 } 684 685 /* 686 * Preserve KAME behaviour: ENOENT can be returned 687 * when an SA acquire is in progress. Don't propagate 688 * this to user-level; it confuses applications. 689 * 690 * XXX this will go away when the SADB is redone. 691 */ 692 if (error == ENOENT) 693 error = 0; 694 KEY_SP_UNREF(&sp); 695 splx(s); 696 *done = true; 697 return error; 698 } 699 700 int 701 ipsec_ip_input(struct mbuf *m, bool forward) 702 { 703 struct secpolicy *sp; 704 int error, s; 705 706 s = splsoftnet(); 707 error = ipsec_in_reject(m, NULL); 708 splx(s); 709 if (error) { 710 return EINVAL; 711 } 712 713 if (!forward || !(m->m_flags & M_CANFASTFWD)) { 714 return 0; 715 } 716 717 /* 718 * Peek at the outbound SP for this packet to determine if 719 * it is a Fast Forward candidate. 720 */ 721 s = splsoftnet(); 722 sp = ipsec_checkpolicy(m, IPSEC_DIR_OUTBOUND, IP_FORWARDING, 723 &error, NULL); 724 if (sp != NULL) { 725 m->m_flags &= ~M_CANFASTFWD; 726 KEY_SP_UNREF(&sp); 727 } 728 splx(s); 729 730 return 0; 731 } 732 733 /* 734 * If the packet is routed over IPsec tunnel, tell the originator the 735 * tunnel MTU. 736 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz 737 * 738 * XXX: Quick hack!!! 739 * 740 * XXX: And what if the MTU goes negative? 741 */ 742 void 743 ipsec_mtu(struct mbuf *m, int *destmtu) 744 { 745 struct secpolicy *sp; 746 size_t ipsechdr; 747 int error; 748 749 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, IP_FORWARDING, 750 &error); 751 if (sp == NULL) { 752 return; 753 } 754 755 /* Count IPsec header size. */ 756 ipsechdr = ipsec_sp_hdrsiz(sp, m); 757 758 /* 759 * Find the correct route for outer IP header, compute tunnel MTU. 760 */ 761 if (sp->req) { 762 struct secasvar *sav; 763 764 sav = ipsec_lookup_sa(sp->req, m); 765 if (sav != NULL) { 766 struct route *ro; 767 struct rtentry *rt; 768 769 ro = &sav->sah->sa_route; 770 rt = rtcache_validate(ro); 771 if (rt && rt->rt_ifp) { 772 *destmtu = rt->rt_rmx.rmx_mtu ? 773 rt->rt_rmx.rmx_mtu : rt->rt_ifp->if_mtu; 774 *destmtu -= ipsechdr; 775 } 776 rtcache_unref(rt, ro); 777 KEY_SA_UNREF(&sav); 778 } 779 } 780 KEY_SP_UNREF(&sp); 781 } 782 783 static int 784 ipsec_setspidx_inpcb(struct mbuf *m, void *pcb) 785 { 786 struct inpcb_hdr *inph = (struct inpcb_hdr *)pcb; 787 int error; 788 789 KASSERT(inph != NULL); 790 KASSERT(inph->inph_sp != NULL); 791 KASSERT(inph->inph_sp->sp_out != NULL); 792 KASSERT(inph->inph_sp->sp_in != NULL); 793 794 error = ipsec_setspidx(m, &inph->inph_sp->sp_in->spidx, 1); 795 if (error == 0) { 796 inph->inph_sp->sp_in->spidx.dir = IPSEC_DIR_INBOUND; 797 inph->inph_sp->sp_out->spidx = inph->inph_sp->sp_in->spidx; 798 inph->inph_sp->sp_out->spidx.dir = IPSEC_DIR_OUTBOUND; 799 } else { 800 memset(&inph->inph_sp->sp_in->spidx, 0, 801 sizeof(inph->inph_sp->sp_in->spidx)); 802 memset(&inph->inph_sp->sp_out->spidx, 0, 803 sizeof(inph->inph_sp->sp_out->spidx)); 804 } 805 return error; 806 } 807 808 /* 809 * configure security policy index (src/dst/proto/sport/dport) 810 * by looking at the content of mbuf. 811 * the caller is responsible for error recovery (like clearing up spidx). 812 */ 813 static int 814 ipsec_setspidx(struct mbuf *m, struct secpolicyindex *spidx, int needport) 815 { 816 struct ip *ip = NULL; 817 struct ip ipbuf; 818 u_int v; 819 int error; 820 821 KASSERT(m != NULL); 822 M_VERIFY_PACKET(m); 823 824 if (m->m_pkthdr.len < sizeof(struct ip)) { 825 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 826 "pkthdr.len(%d) < sizeof(struct ip), ignored.\n", 827 m->m_pkthdr.len); 828 return EINVAL; 829 } 830 831 if (m->m_len >= sizeof(*ip)) { 832 ip = mtod(m, struct ip *); 833 } else { 834 m_copydata(m, 0, sizeof(ipbuf), &ipbuf); 835 ip = &ipbuf; 836 } 837 v = ip->ip_v; 838 switch (v) { 839 case 4: 840 error = ipsec4_setspidx_ipaddr(m, spidx); 841 if (error) 842 return error; 843 ipsec4_get_ulp(m, spidx, needport); 844 return 0; 845 #ifdef INET6 846 case 6: 847 if (m->m_pkthdr.len < sizeof(struct ip6_hdr)) { 848 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 849 "pkthdr.len(%d) < sizeof(struct ip6_hdr), " 850 "ignored.\n", m->m_pkthdr.len); 851 return EINVAL; 852 } 853 error = ipsec6_setspidx_ipaddr(m, spidx); 854 if (error) 855 return error; 856 ipsec6_get_ulp(m, spidx, needport); 857 return 0; 858 #endif 859 default: 860 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 861 "unknown IP version %u, ignored.\n", v); 862 return EINVAL; 863 } 864 } 865 866 static void 867 ipsec4_get_ulp(struct mbuf *m, struct secpolicyindex *spidx, int needport) 868 { 869 u_int8_t nxt; 870 int off; 871 872 KASSERT(m != NULL); 873 KASSERTMSG(m->m_pkthdr.len >= sizeof(struct ip), "packet too short"); 874 875 /* NB: ip_input() flips it into host endian XXX need more checking */ 876 if (m->m_len >= sizeof(struct ip)) { 877 struct ip *ip = mtod(m, struct ip *); 878 if (ip->ip_off & htons(IP_MF | IP_OFFMASK)) 879 goto done; 880 off = ip->ip_hl << 2; 881 nxt = ip->ip_p; 882 } else { 883 struct ip ih; 884 885 m_copydata(m, 0, sizeof(struct ip), &ih); 886 if (ih.ip_off & htons(IP_MF | IP_OFFMASK)) 887 goto done; 888 off = ih.ip_hl << 2; 889 nxt = ih.ip_p; 890 } 891 892 while (off < m->m_pkthdr.len) { 893 struct ip6_ext ip6e; 894 struct tcphdr th; 895 struct udphdr uh; 896 struct icmp icmph; 897 898 switch (nxt) { 899 case IPPROTO_TCP: 900 spidx->ul_proto = nxt; 901 if (!needport) 902 goto done_proto; 903 if (off + sizeof(struct tcphdr) > m->m_pkthdr.len) 904 goto done; 905 m_copydata(m, off, sizeof(th), &th); 906 spidx->src.sin.sin_port = th.th_sport; 907 spidx->dst.sin.sin_port = th.th_dport; 908 return; 909 case IPPROTO_UDP: 910 spidx->ul_proto = nxt; 911 if (!needport) 912 goto done_proto; 913 if (off + sizeof(struct udphdr) > m->m_pkthdr.len) 914 goto done; 915 m_copydata(m, off, sizeof(uh), &uh); 916 spidx->src.sin.sin_port = uh.uh_sport; 917 spidx->dst.sin.sin_port = uh.uh_dport; 918 return; 919 case IPPROTO_AH: 920 if (off + sizeof(ip6e) > m->m_pkthdr.len) 921 goto done; 922 /* XXX sigh, this works but is totally bogus */ 923 m_copydata(m, off, sizeof(ip6e), &ip6e); 924 off += (ip6e.ip6e_len + 2) << 2; 925 nxt = ip6e.ip6e_nxt; 926 break; 927 case IPPROTO_ICMP: 928 spidx->ul_proto = nxt; 929 if (off + sizeof(struct icmp) > m->m_pkthdr.len) 930 goto done; 931 m_copydata(m, off, sizeof(icmph), &icmph); 932 ((struct sockaddr_in *)&spidx->src)->sin_port = 933 htons((uint16_t)icmph.icmp_type); 934 ((struct sockaddr_in *)&spidx->dst)->sin_port = 935 htons((uint16_t)icmph.icmp_code); 936 return; 937 default: 938 /* XXX intermediate headers??? */ 939 spidx->ul_proto = nxt; 940 goto done_proto; 941 } 942 } 943 done: 944 spidx->ul_proto = IPSEC_ULPROTO_ANY; 945 done_proto: 946 spidx->src.sin.sin_port = IPSEC_PORT_ANY; 947 spidx->dst.sin.sin_port = IPSEC_PORT_ANY; 948 } 949 950 static int 951 ipsec4_setspidx_ipaddr(struct mbuf *m, struct secpolicyindex *spidx) 952 { 953 static const struct sockaddr_in template = { 954 sizeof(struct sockaddr_in), 955 AF_INET, 956 0, { 0 }, { 0, 0, 0, 0, 0, 0, 0, 0 } 957 }; 958 959 spidx->src.sin = template; 960 spidx->dst.sin = template; 961 962 if (m->m_len < sizeof(struct ip)) { 963 m_copydata(m, offsetof(struct ip, ip_src), 964 sizeof(struct in_addr), &spidx->src.sin.sin_addr); 965 m_copydata(m, offsetof(struct ip, ip_dst), 966 sizeof(struct in_addr), &spidx->dst.sin.sin_addr); 967 } else { 968 struct ip *ip = mtod(m, struct ip *); 969 spidx->src.sin.sin_addr = ip->ip_src; 970 spidx->dst.sin.sin_addr = ip->ip_dst; 971 } 972 973 spidx->prefs = sizeof(struct in_addr) << 3; 974 spidx->prefd = sizeof(struct in_addr) << 3; 975 976 return 0; 977 } 978 979 #ifdef INET6 980 static void 981 ipsec6_get_ulp(struct mbuf *m, struct secpolicyindex *spidx, int needport) 982 { 983 int off, nxt; 984 struct tcphdr th; 985 struct udphdr uh; 986 struct icmp6_hdr icmph; 987 988 KASSERT(m != NULL); 989 990 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DUMP)) { 991 kdebug_mbuf(__func__, m); 992 } 993 994 /* set default */ 995 spidx->ul_proto = IPSEC_ULPROTO_ANY; 996 ((struct sockaddr_in6 *)&spidx->src)->sin6_port = IPSEC_PORT_ANY; 997 ((struct sockaddr_in6 *)&spidx->dst)->sin6_port = IPSEC_PORT_ANY; 998 999 nxt = -1; 1000 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt); 1001 if (off < 0 || m->m_pkthdr.len < off) 1002 return; 1003 1004 switch (nxt) { 1005 case IPPROTO_TCP: 1006 spidx->ul_proto = nxt; 1007 if (!needport) 1008 break; 1009 if (off + sizeof(struct tcphdr) > m->m_pkthdr.len) 1010 break; 1011 m_copydata(m, off, sizeof(th), &th); 1012 ((struct sockaddr_in6 *)&spidx->src)->sin6_port = th.th_sport; 1013 ((struct sockaddr_in6 *)&spidx->dst)->sin6_port = th.th_dport; 1014 break; 1015 case IPPROTO_UDP: 1016 spidx->ul_proto = nxt; 1017 if (!needport) 1018 break; 1019 if (off + sizeof(struct udphdr) > m->m_pkthdr.len) 1020 break; 1021 m_copydata(m, off, sizeof(uh), &uh); 1022 ((struct sockaddr_in6 *)&spidx->src)->sin6_port = uh.uh_sport; 1023 ((struct sockaddr_in6 *)&spidx->dst)->sin6_port = uh.uh_dport; 1024 break; 1025 case IPPROTO_ICMPV6: 1026 spidx->ul_proto = nxt; 1027 if (off + sizeof(struct icmp6_hdr) > m->m_pkthdr.len) 1028 break; 1029 m_copydata(m, off, sizeof(icmph), &icmph); 1030 ((struct sockaddr_in6 *)&spidx->src)->sin6_port = 1031 htons((uint16_t)icmph.icmp6_type); 1032 ((struct sockaddr_in6 *)&spidx->dst)->sin6_port = 1033 htons((uint16_t)icmph.icmp6_code); 1034 break; 1035 default: 1036 /* XXX intermediate headers??? */ 1037 spidx->ul_proto = nxt; 1038 break; 1039 } 1040 } 1041 1042 static int 1043 ipsec6_setspidx_ipaddr(struct mbuf *m, struct secpolicyindex *spidx) 1044 { 1045 struct ip6_hdr *ip6 = NULL; 1046 struct ip6_hdr ip6buf; 1047 struct sockaddr_in6 *sin6; 1048 1049 if (m->m_len >= sizeof(*ip6)) { 1050 ip6 = mtod(m, struct ip6_hdr *); 1051 } else { 1052 m_copydata(m, 0, sizeof(ip6buf), &ip6buf); 1053 ip6 = &ip6buf; 1054 } 1055 1056 sin6 = (struct sockaddr_in6 *)&spidx->src; 1057 memset(sin6, 0, sizeof(*sin6)); 1058 sin6->sin6_family = AF_INET6; 1059 sin6->sin6_len = sizeof(struct sockaddr_in6); 1060 memcpy(&sin6->sin6_addr, &ip6->ip6_src, sizeof(ip6->ip6_src)); 1061 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) { 1062 sin6->sin6_addr.s6_addr16[1] = 0; 1063 sin6->sin6_scope_id = ntohs(ip6->ip6_src.s6_addr16[1]); 1064 } 1065 spidx->prefs = sizeof(struct in6_addr) << 3; 1066 1067 sin6 = (struct sockaddr_in6 *)&spidx->dst; 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_dst, sizeof(ip6->ip6_dst)); 1072 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) { 1073 sin6->sin6_addr.s6_addr16[1] = 0; 1074 sin6->sin6_scope_id = ntohs(ip6->ip6_dst.s6_addr16[1]); 1075 } 1076 spidx->prefd = sizeof(struct in6_addr) << 3; 1077 1078 return 0; 1079 } 1080 #endif 1081 1082 static void 1083 ipsec_delpcbpolicy(struct inpcbpolicy *p) 1084 { 1085 1086 kmem_intr_free(p, sizeof(*p)); 1087 } 1088 1089 int 1090 ipsec_init_pcbpolicy(struct socket *so, struct inpcbpolicy **policy) 1091 { 1092 struct inpcbpolicy *new; 1093 1094 KASSERT(so != NULL); 1095 KASSERT(policy != NULL); 1096 1097 new = kmem_intr_zalloc(sizeof(*new), KM_NOSLEEP); 1098 if (new == NULL) { 1099 IPSECLOG(LOG_DEBUG, "No more memory.\n"); 1100 return ENOBUFS; 1101 } 1102 1103 if (IPSEC_PRIVILEGED_SO(so)) 1104 new->priv = 1; 1105 else 1106 new->priv = 0; 1107 1108 /* 1109 * Set dummy SPs. Actual SPs will be allocated later if needed. 1110 */ 1111 new->sp_in = &ipsec_dummy_sp; 1112 new->sp_out = &ipsec_dummy_sp; 1113 1114 *policy = new; 1115 1116 return 0; 1117 } 1118 1119 static void 1120 ipsec_destroy_policy(struct secpolicy *sp) 1121 { 1122 1123 if (sp == &ipsec_dummy_sp) { 1124 ; /* It's dummy. No need to free it. */ 1125 } else { 1126 /* 1127 * We cannot destroy here because it can be called in 1128 * softint. So mark the SP as DEAD and let the timer 1129 * destroy it. See key_timehandler_spd. 1130 */ 1131 sp->state = IPSEC_SPSTATE_DEAD; 1132 } 1133 } 1134 1135 int 1136 ipsec_set_policy(void *inp, const void *request, size_t len, 1137 kauth_cred_t cred) 1138 { 1139 struct inpcb_hdr *inph = (struct inpcb_hdr *)inp; 1140 const struct sadb_x_policy *xpl; 1141 struct secpolicy *newsp, *oldsp; 1142 struct secpolicy **policy; 1143 int error; 1144 1145 KASSERT(!cpu_softintr_p()); 1146 KASSERT(inph != NULL); 1147 KASSERT(inph_locked(inph)); 1148 KASSERT(request != NULL); 1149 1150 if (len < sizeof(*xpl)) 1151 return EINVAL; 1152 xpl = (const struct sadb_x_policy *)request; 1153 1154 KASSERT(inph->inph_sp != NULL); 1155 1156 /* select direction */ 1157 switch (xpl->sadb_x_policy_dir) { 1158 case IPSEC_DIR_INBOUND: 1159 policy = &inph->inph_sp->sp_in; 1160 break; 1161 case IPSEC_DIR_OUTBOUND: 1162 policy = &inph->inph_sp->sp_out; 1163 break; 1164 default: 1165 IPSECLOG(LOG_ERR, "invalid direction=%u\n", 1166 xpl->sadb_x_policy_dir); 1167 return EINVAL; 1168 } 1169 1170 /* sanity check. */ 1171 if (policy == NULL || *policy == NULL) 1172 return EINVAL; 1173 1174 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DUMP)) { 1175 kdebug_sadb_xpolicy("set passed policy", request); 1176 } 1177 1178 /* check policy type */ 1179 /* ipsec_set_policy() accepts IPSEC, ENTRUST and BYPASS. */ 1180 if (xpl->sadb_x_policy_type == IPSEC_POLICY_DISCARD || 1181 xpl->sadb_x_policy_type == IPSEC_POLICY_NONE) 1182 return EINVAL; 1183 1184 /* check privileged socket */ 1185 if (xpl->sadb_x_policy_type == IPSEC_POLICY_BYPASS) { 1186 error = kauth_authorize_network(cred, KAUTH_NETWORK_IPSEC, 1187 KAUTH_REQ_NETWORK_IPSEC_BYPASS, NULL, NULL, NULL); 1188 if (error) 1189 return error; 1190 } 1191 1192 /* allocation new SP entry */ 1193 if ((newsp = key_msg2sp(xpl, len, &error)) == NULL) 1194 return error; 1195 1196 key_init_sp(newsp); 1197 newsp->created = time_uptime; 1198 /* Insert the global list for SPs for sockets */ 1199 key_socksplist_add(newsp); 1200 1201 /* clear old SP and set new SP */ 1202 oldsp = *policy; 1203 *policy = newsp; 1204 ipsec_destroy_policy(oldsp); 1205 1206 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DUMP)) { 1207 printf("%s: new policy\n", __func__); 1208 kdebug_secpolicy(newsp); 1209 } 1210 1211 return 0; 1212 } 1213 1214 int 1215 ipsec_get_policy(void *inp, const void *request, size_t len, 1216 struct mbuf **mp) 1217 { 1218 struct inpcb_hdr *inph = (struct inpcb_hdr *)inp; 1219 const struct sadb_x_policy *xpl; 1220 struct secpolicy *policy; 1221 1222 /* sanity check. */ 1223 if (inph == NULL || request == NULL || mp == NULL) 1224 return EINVAL; 1225 KASSERT(inph->inph_sp != NULL); 1226 if (len < sizeof(*xpl)) 1227 return EINVAL; 1228 xpl = (const struct sadb_x_policy *)request; 1229 1230 /* select direction */ 1231 switch (xpl->sadb_x_policy_dir) { 1232 case IPSEC_DIR_INBOUND: 1233 policy = inph->inph_sp->sp_in; 1234 break; 1235 case IPSEC_DIR_OUTBOUND: 1236 policy = inph->inph_sp->sp_out; 1237 break; 1238 default: 1239 IPSECLOG(LOG_ERR, "invalid direction=%u\n", 1240 xpl->sadb_x_policy_dir); 1241 return EINVAL; 1242 } 1243 1244 if (policy == NULL) 1245 return EINVAL; 1246 1247 *mp = key_sp2msg(policy, M_NOWAIT); 1248 if (!*mp) { 1249 IPSECLOG(LOG_DEBUG, "No more memory.\n"); 1250 return ENOBUFS; 1251 } 1252 1253 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DUMP)) { 1254 kdebug_mbuf(__func__, *mp); 1255 } 1256 1257 return 0; 1258 } 1259 1260 int 1261 ipsec_delete_pcbpolicy(void *inp) 1262 { 1263 struct inpcb_hdr *inph = (struct inpcb_hdr *)inp; 1264 1265 KASSERT(inph != NULL); 1266 1267 if (inph->inph_sp == NULL) 1268 return 0; 1269 1270 if (inph->inph_sp->sp_in != NULL) 1271 ipsec_destroy_policy(inph->inph_sp->sp_in); 1272 1273 if (inph->inph_sp->sp_out != NULL) 1274 ipsec_destroy_policy(inph->inph_sp->sp_out); 1275 1276 ipsec_invalpcbcache(inph->inph_sp, IPSEC_DIR_ANY); 1277 1278 ipsec_delpcbpolicy(inph->inph_sp); 1279 inph->inph_sp = NULL; 1280 1281 return 0; 1282 } 1283 1284 /* 1285 * Return the current level (either IPSEC_LEVEL_USE or IPSEC_LEVEL_REQUIRE). 1286 */ 1287 u_int 1288 ipsec_get_reqlevel(const struct ipsecrequest *isr) 1289 { 1290 u_int level = 0; 1291 u_int esp_trans_deflev, esp_net_deflev; 1292 u_int ah_trans_deflev, ah_net_deflev; 1293 1294 KASSERT(isr != NULL); 1295 KASSERT(isr->sp != NULL); 1296 KASSERTMSG( 1297 isr->sp->spidx.src.sa.sa_family == isr->sp->spidx.dst.sa.sa_family, 1298 "af family mismatch, src %u, dst %u", 1299 isr->sp->spidx.src.sa.sa_family, isr->sp->spidx.dst.sa.sa_family); 1300 1301 /* XXX note that we have ipseclog() expanded here - code sync issue */ 1302 #define IPSEC_CHECK_DEFAULT(lev) \ 1303 (((lev) != IPSEC_LEVEL_USE && (lev) != IPSEC_LEVEL_REQUIRE \ 1304 && (lev) != IPSEC_LEVEL_UNIQUE) ? \ 1305 (ipsec_debug ? log(LOG_INFO, "fixed system default level " #lev \ 1306 ":%d->%d\n", (lev), IPSEC_LEVEL_REQUIRE) : (void)0), \ 1307 (lev) = IPSEC_LEVEL_REQUIRE, (lev) \ 1308 : (lev)) 1309 1310 /* set default level */ 1311 switch (((struct sockaddr *)&isr->sp->spidx.src)->sa_family) { 1312 #ifdef INET 1313 case AF_INET: 1314 esp_trans_deflev = IPSEC_CHECK_DEFAULT(ip4_esp_trans_deflev); 1315 esp_net_deflev = IPSEC_CHECK_DEFAULT(ip4_esp_net_deflev); 1316 ah_trans_deflev = IPSEC_CHECK_DEFAULT(ip4_ah_trans_deflev); 1317 ah_net_deflev = IPSEC_CHECK_DEFAULT(ip4_ah_net_deflev); 1318 break; 1319 #endif 1320 #ifdef INET6 1321 case AF_INET6: 1322 esp_trans_deflev = IPSEC_CHECK_DEFAULT(ip6_esp_trans_deflev); 1323 esp_net_deflev = IPSEC_CHECK_DEFAULT(ip6_esp_net_deflev); 1324 ah_trans_deflev = IPSEC_CHECK_DEFAULT(ip6_ah_trans_deflev); 1325 ah_net_deflev = IPSEC_CHECK_DEFAULT(ip6_ah_net_deflev); 1326 break; 1327 #endif 1328 default: 1329 panic("%s: unknown af %u", __func__, 1330 isr->sp->spidx.src.sa.sa_family); 1331 } 1332 1333 #undef IPSEC_CHECK_DEFAULT 1334 1335 /* set level */ 1336 switch (isr->level) { 1337 case IPSEC_LEVEL_DEFAULT: 1338 switch (isr->saidx.proto) { 1339 case IPPROTO_ESP: 1340 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) 1341 level = esp_net_deflev; 1342 else 1343 level = esp_trans_deflev; 1344 break; 1345 case IPPROTO_AH: 1346 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) 1347 level = ah_net_deflev; 1348 else 1349 level = ah_trans_deflev; 1350 break; 1351 case IPPROTO_IPCOMP: 1352 /* 1353 * we don't really care, as IPcomp document says that 1354 * we shouldn't compress small packets 1355 */ 1356 level = IPSEC_LEVEL_USE; 1357 break; 1358 default: 1359 panic("%s: Illegal protocol defined %u", __func__, 1360 isr->saidx.proto); 1361 } 1362 break; 1363 1364 case IPSEC_LEVEL_USE: 1365 case IPSEC_LEVEL_REQUIRE: 1366 level = isr->level; 1367 break; 1368 case IPSEC_LEVEL_UNIQUE: 1369 level = IPSEC_LEVEL_REQUIRE; 1370 break; 1371 1372 default: 1373 panic("%s: Illegal IPsec level %u", __func__, isr->level); 1374 } 1375 1376 return level; 1377 } 1378 1379 /* 1380 * Check security policy requirements against the actual packet contents. 1381 * 1382 * If the SP requires an IPsec packet, and the packet was neither AH nor ESP, 1383 * then kick it. 1384 */ 1385 static int 1386 ipsec_sp_reject(const struct secpolicy *sp, const struct mbuf *m) 1387 { 1388 struct ipsecrequest *isr; 1389 1390 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DATA)) { 1391 printf("%s: using SP\n", __func__); 1392 kdebug_secpolicy(sp); 1393 } 1394 1395 /* check policy */ 1396 switch (sp->policy) { 1397 case IPSEC_POLICY_DISCARD: 1398 return 1; 1399 case IPSEC_POLICY_BYPASS: 1400 case IPSEC_POLICY_NONE: 1401 return 0; 1402 } 1403 1404 KASSERTMSG(sp->policy == IPSEC_POLICY_IPSEC, 1405 "invalid policy %u", sp->policy); 1406 1407 /* XXX should compare policy against ipsec header history */ 1408 1409 for (isr = sp->req; isr != NULL; isr = isr->next) { 1410 if (ipsec_get_reqlevel(isr) != IPSEC_LEVEL_REQUIRE) 1411 continue; 1412 switch (isr->saidx.proto) { 1413 case IPPROTO_ESP: 1414 if ((m->m_flags & M_DECRYPTED) == 0) { 1415 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 1416 "ESP m_flags:%x\n", m->m_flags); 1417 return 1; 1418 } 1419 break; 1420 case IPPROTO_AH: 1421 if ((m->m_flags & M_AUTHIPHDR) == 0) { 1422 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 1423 "AH m_flags:%x\n", m->m_flags); 1424 return 1; 1425 } 1426 break; 1427 case IPPROTO_IPCOMP: 1428 /* 1429 * We don't really care, as IPcomp document 1430 * says that we shouldn't compress small 1431 * packets, IPComp policy should always be 1432 * treated as being in "use" level. 1433 */ 1434 break; 1435 } 1436 } 1437 1438 return 0; 1439 } 1440 1441 /* 1442 * Check security policy requirements. 1443 */ 1444 int 1445 ipsec_in_reject(struct mbuf *m, void *inp) 1446 { 1447 struct inpcb_hdr *inph = (struct inpcb_hdr *)inp; 1448 struct secpolicy *sp; 1449 int error; 1450 int result; 1451 1452 KASSERT(m != NULL); 1453 1454 if (inph == NULL) 1455 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND, 1456 IP_FORWARDING, &error); 1457 else 1458 sp = ipsec_getpolicybysock(m, IPSEC_DIR_INBOUND, 1459 inph, &error); 1460 1461 if (sp != NULL) { 1462 result = ipsec_sp_reject(sp, m); 1463 if (result) 1464 IPSEC_STATINC(IPSEC_STAT_IN_POLVIO); 1465 KEY_SP_UNREF(&sp); 1466 } else { 1467 result = 0; 1468 } 1469 return result; 1470 } 1471 1472 /* 1473 * Compute the byte size to be occupied by the IPsec header. If it is 1474 * tunneled, it includes the size of outer IP header. 1475 */ 1476 static size_t 1477 ipsec_sp_hdrsiz(const struct secpolicy *sp, const struct mbuf *m) 1478 { 1479 struct ipsecrequest *isr; 1480 size_t siz; 1481 1482 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DATA)) { 1483 printf("%s: using SP\n", __func__); 1484 kdebug_secpolicy(sp); 1485 } 1486 1487 switch (sp->policy) { 1488 case IPSEC_POLICY_DISCARD: 1489 case IPSEC_POLICY_BYPASS: 1490 case IPSEC_POLICY_NONE: 1491 return 0; 1492 } 1493 1494 KASSERTMSG(sp->policy == IPSEC_POLICY_IPSEC, 1495 "invalid policy %u", sp->policy); 1496 1497 siz = 0; 1498 for (isr = sp->req; isr != NULL; isr = isr->next) { 1499 size_t clen = 0; 1500 struct secasvar *sav; 1501 1502 switch (isr->saidx.proto) { 1503 case IPPROTO_ESP: 1504 sav = ipsec_lookup_sa(isr, m); 1505 if (sav != NULL) { 1506 clen = esp_hdrsiz(sav); 1507 KEY_SA_UNREF(&sav); 1508 } else 1509 clen = esp_hdrsiz(NULL); 1510 break; 1511 case IPPROTO_AH: 1512 sav = ipsec_lookup_sa(isr, m); 1513 if (sav != NULL) { 1514 clen = ah_hdrsiz(sav); 1515 KEY_SA_UNREF(&sav); 1516 } else 1517 clen = ah_hdrsiz(NULL); 1518 break; 1519 case IPPROTO_IPCOMP: 1520 clen = sizeof(struct ipcomp); 1521 break; 1522 } 1523 1524 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) { 1525 switch (isr->saidx.dst.sa.sa_family) { 1526 case AF_INET: 1527 clen += sizeof(struct ip); 1528 break; 1529 #ifdef INET6 1530 case AF_INET6: 1531 clen += sizeof(struct ip6_hdr); 1532 break; 1533 #endif 1534 default: 1535 IPSECLOG(LOG_ERR, "unknown AF %d in " 1536 "IPsec tunnel SA\n", 1537 ((const struct sockaddr *)&isr->saidx.dst) 1538 ->sa_family); 1539 break; 1540 } 1541 } 1542 siz += clen; 1543 } 1544 1545 return siz; 1546 } 1547 1548 size_t 1549 ipsec_hdrsiz(struct mbuf *m, u_int dir, void *inp) 1550 { 1551 struct inpcb_hdr *inph = (struct inpcb_hdr *)inp; 1552 struct secpolicy *sp; 1553 int error; 1554 size_t size; 1555 1556 KASSERT(m != NULL); 1557 KASSERTMSG(inph == NULL || inph->inph_socket != NULL, 1558 "socket w/o inpcb"); 1559 1560 if (inph == NULL) 1561 sp = ipsec_getpolicybyaddr(m, dir, IP_FORWARDING, &error); 1562 else 1563 sp = ipsec_getpolicybysock(m, dir, inph, &error); 1564 1565 if (sp != NULL) { 1566 size = ipsec_sp_hdrsiz(sp, m); 1567 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DATA, "size:%zu.\n", size); 1568 KEY_SP_UNREF(&sp); 1569 } else { 1570 size = 0; 1571 } 1572 1573 return size; 1574 } 1575 1576 /* 1577 * Check the variable replay window. 1578 * ipsec_chkreplay() performs replay check before ICV verification. 1579 * ipsec_updatereplay() updates replay bitmap. This must be called after 1580 * ICV verification (it also performs replay check, which is usually done 1581 * beforehand). 1582 * 0 (zero) is returned if packet disallowed, 1 if packet permitted. 1583 * 1584 * based on RFC 2401. 1585 */ 1586 int 1587 ipsec_chkreplay(u_int32_t seq, const struct secasvar *sav) 1588 { 1589 const struct secreplay *replay; 1590 u_int32_t diff; 1591 int fr; 1592 u_int32_t wsizeb; /* constant: bits of window size */ 1593 int frlast; /* constant: last frame */ 1594 1595 KASSERT(sav != NULL); 1596 KASSERT(sav->replay != NULL); 1597 1598 replay = sav->replay; 1599 1600 if (replay->wsize == 0) 1601 return 1; /* no need to check replay. */ 1602 1603 /* constant */ 1604 frlast = replay->wsize - 1; 1605 wsizeb = replay->wsize << 3; 1606 1607 /* sequence number of 0 is invalid */ 1608 if (seq == 0) 1609 return 0; 1610 1611 /* first time is always okay */ 1612 if (replay->count == 0) 1613 return 1; 1614 1615 if (seq > replay->lastseq) { 1616 /* larger sequences are okay */ 1617 return 1; 1618 } else { 1619 /* seq is equal or less than lastseq. */ 1620 diff = replay->lastseq - seq; 1621 1622 /* over range to check, i.e. too old or wrapped */ 1623 if (diff >= wsizeb) 1624 return 0; 1625 1626 fr = frlast - diff / 8; 1627 1628 /* this packet already seen ? */ 1629 if ((replay->bitmap)[fr] & (1 << (diff % 8))) 1630 return 0; 1631 1632 /* out of order but good */ 1633 return 1; 1634 } 1635 } 1636 1637 /* 1638 * check replay counter whether to update or not. 1639 * OUT: 0: OK 1640 * 1: NG 1641 */ 1642 int 1643 ipsec_updatereplay(u_int32_t seq, const struct secasvar *sav) 1644 { 1645 struct secreplay *replay; 1646 u_int32_t diff; 1647 int fr; 1648 u_int32_t wsizeb; /* constant: bits of window size */ 1649 int frlast; /* constant: last frame */ 1650 1651 KASSERT(sav != NULL); 1652 KASSERT(sav->replay != NULL); 1653 1654 replay = sav->replay; 1655 1656 if (replay->wsize == 0) 1657 goto ok; /* no need to check replay. */ 1658 1659 /* constant */ 1660 frlast = replay->wsize - 1; 1661 wsizeb = replay->wsize << 3; 1662 1663 /* sequence number of 0 is invalid */ 1664 if (seq == 0) 1665 return 1; 1666 1667 /* first time */ 1668 if (replay->count == 0) { 1669 replay->lastseq = seq; 1670 memset(replay->bitmap, 0, replay->wsize); 1671 (replay->bitmap)[frlast] = 1; 1672 goto ok; 1673 } 1674 1675 if (seq > replay->lastseq) { 1676 /* seq is larger than lastseq. */ 1677 diff = seq - replay->lastseq; 1678 1679 /* new larger sequence number */ 1680 if (diff < wsizeb) { 1681 /* In window */ 1682 /* set bit for this packet */ 1683 vshiftl(replay->bitmap, diff, replay->wsize); 1684 (replay->bitmap)[frlast] |= 1; 1685 } else { 1686 /* this packet has a "way larger" */ 1687 memset(replay->bitmap, 0, replay->wsize); 1688 (replay->bitmap)[frlast] = 1; 1689 } 1690 replay->lastseq = seq; 1691 1692 /* larger is good */ 1693 } else { 1694 /* seq is equal or less than lastseq. */ 1695 diff = replay->lastseq - seq; 1696 1697 /* over range to check, i.e. too old or wrapped */ 1698 if (diff >= wsizeb) 1699 return 1; 1700 1701 fr = frlast - diff / 8; 1702 1703 /* this packet already seen ? */ 1704 if ((replay->bitmap)[fr] & (1 << (diff % 8))) 1705 return 1; 1706 1707 /* mark as seen */ 1708 (replay->bitmap)[fr] |= (1 << (diff % 8)); 1709 1710 /* out of order but good */ 1711 } 1712 1713 ok: 1714 if (replay->count == ~0) { 1715 char buf[IPSEC_LOGSASTRLEN]; 1716 1717 /* set overflow flag */ 1718 replay->overflow++; 1719 1720 /* don't increment, no more packets accepted */ 1721 if ((sav->flags & SADB_X_EXT_CYCSEQ) == 0) 1722 return 1; 1723 1724 IPSECLOG(LOG_WARNING, "replay counter made %d cycle. %s\n", 1725 replay->overflow, ipsec_logsastr(sav, buf, sizeof(buf))); 1726 } 1727 1728 replay->count++; 1729 1730 return 0; 1731 } 1732 1733 /* 1734 * shift variable length buffer to left. 1735 * IN: bitmap: pointer to the buffer 1736 * nbit: the number of to shift. 1737 * wsize: buffer size (bytes). 1738 */ 1739 static void 1740 vshiftl(unsigned char *bitmap, int nbit, int wsize) 1741 { 1742 int s, j, i; 1743 unsigned char over; 1744 1745 for (j = 0; j < nbit; j += 8) { 1746 s = (nbit - j < 8) ? (nbit - j): 8; 1747 bitmap[0] <<= s; 1748 for (i = 1; i < wsize; i++) { 1749 over = (bitmap[i] >> (8 - s)); 1750 bitmap[i] <<= s; 1751 bitmap[i-1] |= over; 1752 } 1753 } 1754 1755 return; 1756 } 1757 1758 /* Return a printable string for the address. */ 1759 const char * 1760 ipsec_address(const union sockaddr_union *sa, char *buf, size_t size) 1761 { 1762 switch (sa->sa.sa_family) { 1763 case AF_INET: 1764 in_print(buf, size, &sa->sin.sin_addr); 1765 return buf; 1766 #if INET6 1767 case AF_INET6: 1768 in6_print(buf, size, &sa->sin6.sin6_addr); 1769 return buf; 1770 #endif 1771 default: 1772 return "(unknown address family)"; 1773 } 1774 } 1775 1776 const char * 1777 ipsec_logsastr(const struct secasvar *sav, char *buf, size_t size) 1778 { 1779 const struct secasindex *saidx = &sav->sah->saidx; 1780 char sbuf[IPSEC_ADDRSTRLEN], dbuf[IPSEC_ADDRSTRLEN]; 1781 1782 KASSERTMSG(saidx->src.sa.sa_family == saidx->dst.sa.sa_family, 1783 "af family mismatch, src %u, dst %u", 1784 saidx->src.sa.sa_family, saidx->dst.sa.sa_family); 1785 1786 snprintf(buf, size, "SA(SPI=%u src=%s dst=%s)", 1787 (u_int32_t)ntohl(sav->spi), 1788 ipsec_address(&saidx->src, sbuf, sizeof(sbuf)), 1789 ipsec_address(&saidx->dst, dbuf, sizeof(dbuf))); 1790 1791 return buf; 1792 } 1793 1794 #ifdef INET6 1795 struct secpolicy * 1796 ipsec6_check_policy(struct mbuf *m, struct in6pcb *in6p, int flags, 1797 int *needipsecp, int *errorp) 1798 { 1799 struct secpolicy *sp = NULL; 1800 int s; 1801 int error = 0; 1802 int needipsec = 0; 1803 1804 if (ipsec_outdone(m)) { 1805 goto skippolicycheck; 1806 } 1807 s = splsoftnet(); 1808 if (in6p && ipsec_pcb_skip_ipsec(in6p->in6p_sp, IPSEC_DIR_OUTBOUND)) { 1809 splx(s); 1810 goto skippolicycheck; 1811 } 1812 sp = ipsec_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags, &error, in6p); 1813 splx(s); 1814 1815 /* 1816 * There are four return cases: 1817 * sp != NULL apply IPsec policy 1818 * sp == NULL, error == 0 no IPsec handling needed 1819 * sp == NULL, error == -EINVAL discard packet w/o error 1820 * sp == NULL, error != 0 discard packet, report error 1821 */ 1822 if (sp == NULL) { 1823 needipsec = 0; 1824 } else { 1825 needipsec = 1; 1826 } 1827 1828 skippolicycheck: 1829 *errorp = error; 1830 *needipsecp = needipsec; 1831 return sp; 1832 } 1833 #endif /* INET6 */ 1834 1835 /* 1836 * ----------------------------------------------------------------------------- 1837 */ 1838 1839 /* XXX this stuff doesn't belong here... */ 1840 1841 static struct xformsw *xforms = NULL; 1842 1843 /* 1844 * Register a transform; typically at system startup. 1845 */ 1846 void 1847 xform_register(struct xformsw *xsp) 1848 { 1849 xsp->xf_next = xforms; 1850 xforms = xsp; 1851 } 1852 1853 /* 1854 * Initialize transform support in an sav. 1855 */ 1856 int 1857 xform_init(struct secasvar *sav, int xftype) 1858 { 1859 struct xformsw *xsp; 1860 1861 if (sav->tdb_xform != NULL) /* previously initialized */ 1862 return 0; 1863 for (xsp = xforms; xsp; xsp = xsp->xf_next) 1864 if (xsp->xf_type == xftype) 1865 return (*xsp->xf_init)(sav, xsp); 1866 1867 IPSECLOG(LOG_DEBUG, "no match for xform type %d\n", xftype); 1868 return EINVAL; 1869 } 1870 1871 void 1872 nat_t_ports_get(struct mbuf *m, u_int16_t *dport, u_int16_t *sport) 1873 { 1874 struct m_tag *tag; 1875 1876 if ((tag = m_tag_find(m, PACKET_TAG_IPSEC_NAT_T_PORTS, NULL))) { 1877 *sport = ((u_int16_t *)(tag + 1))[0]; 1878 *dport = ((u_int16_t *)(tag + 1))[1]; 1879 } else 1880 *sport = *dport = 0; 1881 } 1882 1883 /* 1884 * XXXJRT This should be done as a protosw init call. 1885 */ 1886 void 1887 ipsec_attach(void) 1888 { 1889 1890 ipsec_output_init(); 1891 1892 ipsecstat_percpu = percpu_alloc(sizeof(uint64_t) * IPSEC_NSTATS); 1893 1894 sysctl_net_inet_ipsec_setup(NULL); 1895 #ifdef INET6 1896 sysctl_net_inet6_ipsec6_setup(NULL); 1897 #endif 1898 1899 ah_attach(); 1900 esp_attach(); 1901 ipcomp_attach(); 1902 ipe4_attach(); 1903 #ifdef TCP_SIGNATURE 1904 tcpsignature_attach(); 1905 #endif 1906 } 1907
Indexes created Tue Sep 30 11:09:46 GMT 2025