1 /* $NetBSD: ipsec.c,v 1.173 2021/12/08 20:03:26 andvar 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 1.173 2021/12/08 20:03:26 andvar 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, 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, dir, 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, dir, 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 if (key_havesp(dir)) 470 sp = KEY_LOOKUP_SP_BYSPIDX(&currsp->spidx, dir); 471 else 472 sp = NULL; 473 if (sp == NULL) /* no SP found */ 474 sp = KEY_GET_DEFAULT_SP(af); 475 break; 476 477 default: 478 IPSECLOG(LOG_ERR, "Invalid policy for PCB %d\n", 479 currsp->policy); 480 *error = EINVAL; 481 return NULL; 482 } 483 } else { /* unpriv, SPD has policy */ 484 if (key_havesp(dir)) 485 sp = KEY_LOOKUP_SP_BYSPIDX(&currsp->spidx, dir); 486 else 487 sp = NULL; 488 if (sp == NULL) { /* no SP found */ 489 switch (currsp->policy) { 490 case IPSEC_POLICY_BYPASS: 491 IPSECLOG(LOG_ERR, "Illegal policy for " 492 "non-priviliged defined %d\n", 493 currsp->policy); 494 *error = EINVAL; 495 return NULL; 496 497 case IPSEC_POLICY_ENTRUST: 498 sp = KEY_GET_DEFAULT_SP(af); 499 break; 500 501 case IPSEC_POLICY_IPSEC: 502 KEY_SP_REF(currsp); 503 sp = currsp; 504 break; 505 506 default: 507 IPSECLOG(LOG_ERR, "Invalid policy for " 508 "PCB %d\n", currsp->policy); 509 *error = EINVAL; 510 return NULL; 511 } 512 } 513 } 514 KASSERTMSG(sp != NULL, "null SP (priv %u policy %u", pcbsp->priv, 515 currsp->policy); 516 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_STAMP, 517 "DP (priv %u policy %u) allocates SP:%p (refcnt %u)\n", 518 pcbsp->priv, currsp->policy, sp, key_sp_refcnt(sp)); 519 ipsec_fillpcbcache(pcbsp, m, sp, dir); 520 return sp; 521 } 522 523 /* 524 * For FORWARDING packet or OUTBOUND without a socket. Searching SPD for packet, 525 * and return a pointer to SP. 526 * OUT: positive: a pointer to the entry for security policy leaf matched. 527 * NULL: no appropriate SP found, the following value is set to error. 528 * 0 : bypass 529 * EACCES : discard packet. 530 * ENOENT : ipsec_acquire() in progress, maybe. 531 * others : error occurred. 532 */ 533 static struct secpolicy * 534 ipsec_getpolicybyaddr(struct mbuf *m, u_int dir, int flag, int *error) 535 { 536 struct secpolicyindex spidx; 537 struct secpolicy *sp; 538 539 KASSERT(m != NULL); 540 KASSERT(error != NULL); 541 KASSERTMSG(IPSEC_DIR_IS_INOROUT(dir), "invalid direction %u", dir); 542 543 sp = NULL; 544 545 /* Make an index to look for a policy. */ 546 *error = ipsec_setspidx(m, &spidx, dir, (flag & IP_FORWARDING) ? 0 : 1); 547 if (*error != 0) { 548 IPSECLOG(LOG_DEBUG, "setpidx failed, dir %u flag %u\n", dir, flag); 549 memset(&spidx, 0, sizeof(spidx)); 550 return NULL; 551 } 552 553 spidx.dir = dir; 554 555 if (key_havesp(dir)) { 556 sp = KEY_LOOKUP_SP_BYSPIDX(&spidx, dir); 557 } 558 if (sp == NULL) { 559 /* no SP found, use system default */ 560 sp = KEY_GET_DEFAULT_SP(spidx.dst.sa.sa_family); 561 } 562 563 KASSERT(sp != NULL); 564 return sp; 565 } 566 567 static struct secpolicy * 568 ipsec_checkpolicy(struct mbuf *m, u_int dir, u_int flag, int *error, 569 void *inp) 570 { 571 struct secpolicy *sp; 572 573 *error = 0; 574 575 if (inp == NULL) { 576 sp = ipsec_getpolicybyaddr(m, dir, flag, error); 577 } else { 578 struct inpcb_hdr *inph = (struct inpcb_hdr *)inp; 579 KASSERT(inph->inph_socket != NULL); 580 sp = ipsec_getpolicybysock(m, dir, inph, error); 581 } 582 if (sp == NULL) { 583 KASSERTMSG(*error != 0, "getpolicy failed w/o error"); 584 IPSEC_STATINC(IPSEC_STAT_OUT_INVAL); 585 return NULL; 586 } 587 KASSERTMSG(*error == 0, "sp w/ error set to %u", *error); 588 589 switch (sp->policy) { 590 case IPSEC_POLICY_ENTRUST: 591 default: 592 printf("%s: invalid policy %u\n", __func__, sp->policy); 593 /* fall thru... */ 594 case IPSEC_POLICY_DISCARD: 595 IPSEC_STATINC(IPSEC_STAT_OUT_POLVIO); 596 *error = -EINVAL; /* packet is discarded by caller */ 597 break; 598 case IPSEC_POLICY_BYPASS: 599 case IPSEC_POLICY_NONE: 600 KEY_SP_UNREF(&sp); 601 sp = NULL; /* NB: force NULL result */ 602 break; 603 case IPSEC_POLICY_IPSEC: 604 KASSERT(sp->req != NULL); 605 break; 606 } 607 608 if (*error != 0) { 609 KEY_SP_UNREF(&sp); 610 sp = NULL; 611 IPSECLOG(LOG_DEBUG, "done, error %d\n", *error); 612 } 613 614 return sp; 615 } 616 617 int 618 ipsec4_output(struct mbuf *m, struct inpcb *inp, int flags, 619 u_long *mtu, bool *natt_frag, bool *done, bool *count_drop) 620 { 621 struct secpolicy *sp = NULL; 622 u_long _mtu = 0; 623 int error, s; 624 625 /* 626 * Check the security policy (SP) for the packet and, if required, 627 * do IPsec-related processing. There are two cases here; the first 628 * time a packet is sent through it will be untagged and handled by 629 * ipsec_checkpolicy(). If the packet is resubmitted to ip_output 630 * (e.g. after AH, ESP, etc. processing), there will be a tag to 631 * bypass the lookup and related policy checking. 632 */ 633 if (ipsec_outdone(m)) { 634 return 0; 635 } 636 s = splsoftnet(); 637 if (inp && ipsec_pcb_skip_ipsec(inp->inp_sp, IPSEC_DIR_OUTBOUND)) { 638 splx(s); 639 return 0; 640 } 641 sp = ipsec_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags, &error, inp); 642 643 /* 644 * There are four return cases: 645 * sp != NULL apply IPsec policy 646 * sp == NULL, error == 0 no IPsec handling needed 647 * sp == NULL, error == -EINVAL discard packet w/o error 648 * sp == NULL, error != 0 discard packet, report error 649 */ 650 if (sp == NULL) { 651 splx(s); 652 if (error) { 653 /* 654 * Hack: -EINVAL is used to signal that a packet 655 * should be silently discarded. This is typically 656 * because we asked key management for an SA and 657 * it was delayed (e.g. kicked up to IKE). 658 */ 659 if (error == -EINVAL) 660 error = 0; 661 m_freem(m); 662 *done = true; 663 *count_drop = true; 664 return error; 665 } 666 /* No IPsec processing for this packet. */ 667 return 0; 668 } 669 670 /* 671 * Do delayed checksums now because we send before 672 * this is done in the normal processing path. 673 */ 674 if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 675 in_undefer_cksum_tcpudp(m); 676 m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 677 } 678 679 error = ipsec4_process_packet(m, sp->req, &_mtu); 680 if (error == 0 && _mtu != 0) { 681 /* 682 * NAT-T ESP fragmentation: do not do IPSec processing 683 * now, we will do it on each fragmented packet. 684 */ 685 *mtu = _mtu; 686 *natt_frag = true; 687 KEY_SP_UNREF(&sp); 688 splx(s); 689 return 0; 690 } 691 692 /* 693 * Preserve KAME behaviour: ENOENT can be returned 694 * when an SA acquire is in progress. Don't propagate 695 * this to user-level; it confuses applications. 696 * 697 * XXX this will go away when the SADB is redone. 698 */ 699 if (error == ENOENT) 700 error = 0; 701 KEY_SP_UNREF(&sp); 702 splx(s); 703 *done = true; 704 return error; 705 } 706 707 int 708 ipsec_ip_input_checkpolicy(struct mbuf *m, bool forward) 709 { 710 struct secpolicy *sp; 711 int error, s; 712 713 s = splsoftnet(); 714 error = ipsec_in_reject(m, NULL); 715 splx(s); 716 if (error) { 717 return EINVAL; 718 } 719 720 if (!forward || !(m->m_flags & M_CANFASTFWD)) { 721 return 0; 722 } 723 724 /* 725 * Peek at the outbound SP for this packet to determine if 726 * it is a Fast Forward candidate. 727 */ 728 s = splsoftnet(); 729 sp = ipsec_checkpolicy(m, IPSEC_DIR_OUTBOUND, IP_FORWARDING, 730 &error, NULL); 731 if (sp != NULL) { 732 m->m_flags &= ~M_CANFASTFWD; 733 KEY_SP_UNREF(&sp); 734 } 735 splx(s); 736 737 return 0; 738 } 739 740 /* 741 * If the packet is routed over IPsec tunnel, tell the originator the 742 * tunnel MTU. 743 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz 744 * 745 * XXX: Quick hack!!! 746 * 747 * XXX: And what if the MTU goes negative? 748 */ 749 void 750 ipsec_mtu(struct mbuf *m, int *destmtu) 751 { 752 struct secpolicy *sp; 753 size_t ipsechdr; 754 int error; 755 756 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, IP_FORWARDING, 757 &error); 758 if (sp == NULL) { 759 return; 760 } 761 762 /* Count IPsec header size. */ 763 ipsechdr = ipsec_sp_hdrsiz(sp, m); 764 765 /* 766 * Find the correct route for outer IP header, compute tunnel MTU. 767 */ 768 if (sp->req) { 769 struct secasvar *sav; 770 771 sav = ipsec_lookup_sa(sp->req, m); 772 if (sav != NULL) { 773 struct route *ro; 774 struct rtentry *rt; 775 776 ro = &sav->sah->sa_route; 777 rt = rtcache_validate(ro); 778 if (rt && rt->rt_ifp) { 779 *destmtu = rt->rt_rmx.rmx_mtu ? 780 rt->rt_rmx.rmx_mtu : rt->rt_ifp->if_mtu; 781 *destmtu -= ipsechdr; 782 } 783 rtcache_unref(rt, ro); 784 KEY_SA_UNREF(&sav); 785 } 786 } 787 KEY_SP_UNREF(&sp); 788 } 789 790 static int 791 ipsec_setspidx_inpcb(struct mbuf *m, void *pcb) 792 { 793 struct inpcb_hdr *inph = (struct inpcb_hdr *)pcb; 794 int error; 795 796 KASSERT(inph != NULL); 797 KASSERT(inph->inph_sp != NULL); 798 KASSERT(inph->inph_sp->sp_out != NULL); 799 KASSERT(inph->inph_sp->sp_in != NULL); 800 801 error = ipsec_setspidx(m, &inph->inph_sp->sp_in->spidx, 802 IPSEC_DIR_INBOUND, 1); 803 if (error == 0) { 804 inph->inph_sp->sp_out->spidx = inph->inph_sp->sp_in->spidx; 805 inph->inph_sp->sp_out->spidx.dir = IPSEC_DIR_OUTBOUND; 806 } else { 807 memset(&inph->inph_sp->sp_in->spidx, 0, 808 sizeof(inph->inph_sp->sp_in->spidx)); 809 memset(&inph->inph_sp->sp_out->spidx, 0, 810 sizeof(inph->inph_sp->sp_out->spidx)); 811 } 812 return error; 813 } 814 815 /* 816 * configure security policy index (src/dst/proto/sport/dport) 817 * by looking at the content of mbuf. 818 * the caller is responsible for error recovery (like clearing up spidx). 819 */ 820 static int 821 ipsec_setspidx(struct mbuf *m, struct secpolicyindex *spidx, int dir, 822 int needport) 823 { 824 struct ip *ip = NULL; 825 struct ip ipbuf; 826 u_int v; 827 int error; 828 829 KASSERT(m != NULL); 830 M_VERIFY_PACKET(m); 831 832 if (m->m_pkthdr.len < sizeof(struct ip)) { 833 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 834 "pkthdr.len(%d) < sizeof(struct ip), ignored.\n", 835 m->m_pkthdr.len); 836 return EINVAL; 837 } 838 839 memset(spidx, 0, sizeof(*spidx)); 840 spidx->dir = dir; 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 int 1101 ipsec_init_pcbpolicy(struct socket *so, struct inpcbpolicy **policy) 1102 { 1103 struct inpcbpolicy *new; 1104 1105 KASSERT(so != NULL); 1106 KASSERT(policy != NULL); 1107 1108 new = kmem_intr_zalloc(sizeof(*new), KM_NOSLEEP); 1109 if (new == NULL) { 1110 IPSECLOG(LOG_DEBUG, "No more memory.\n"); 1111 return ENOBUFS; 1112 } 1113 1114 if (IPSEC_PRIVILEGED_SO(so)) 1115 new->priv = 1; 1116 else 1117 new->priv = 0; 1118 1119 /* 1120 * Set dummy SPs. Actual SPs will be allocated later if needed. 1121 */ 1122 new->sp_in = &ipsec_dummy_sp; 1123 new->sp_out = &ipsec_dummy_sp; 1124 1125 *policy = new; 1126 1127 return 0; 1128 } 1129 1130 static void 1131 ipsec_destroy_policy(struct secpolicy *sp) 1132 { 1133 1134 if (sp == &ipsec_dummy_sp) { 1135 ; /* It's dummy. No need to free it. */ 1136 } else { 1137 /* 1138 * We cannot destroy here because it can be called in 1139 * softint. So mark the SP as DEAD and let the timer 1140 * destroy it. See key_timehandler_spd. 1141 */ 1142 sp->state = IPSEC_SPSTATE_DEAD; 1143 } 1144 } 1145 1146 int 1147 ipsec_set_policy(void *inp, const void *request, size_t len, 1148 kauth_cred_t cred) 1149 { 1150 struct inpcb_hdr *inph = (struct inpcb_hdr *)inp; 1151 const struct sadb_x_policy *xpl; 1152 struct secpolicy *newsp, *oldsp; 1153 struct secpolicy **policy; 1154 int error; 1155 1156 KASSERT(!cpu_softintr_p()); 1157 KASSERT(inph != NULL); 1158 KASSERT(inph_locked(inph)); 1159 KASSERT(request != NULL); 1160 1161 if (len < sizeof(*xpl)) 1162 return EINVAL; 1163 xpl = (const struct sadb_x_policy *)request; 1164 1165 KASSERT(inph->inph_sp != NULL); 1166 1167 /* select direction */ 1168 switch (xpl->sadb_x_policy_dir) { 1169 case IPSEC_DIR_INBOUND: 1170 policy = &inph->inph_sp->sp_in; 1171 break; 1172 case IPSEC_DIR_OUTBOUND: 1173 policy = &inph->inph_sp->sp_out; 1174 break; 1175 default: 1176 IPSECLOG(LOG_ERR, "invalid direction=%u\n", 1177 xpl->sadb_x_policy_dir); 1178 return EINVAL; 1179 } 1180 1181 /* sanity check. */ 1182 if (policy == NULL || *policy == NULL) 1183 return EINVAL; 1184 1185 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DUMP)) { 1186 kdebug_sadb_xpolicy("set passed policy", request); 1187 } 1188 1189 /* check policy type */ 1190 /* ipsec_set_policy() accepts IPSEC, ENTRUST and BYPASS. */ 1191 if (xpl->sadb_x_policy_type == IPSEC_POLICY_DISCARD || 1192 xpl->sadb_x_policy_type == IPSEC_POLICY_NONE) 1193 return EINVAL; 1194 1195 /* check privileged socket */ 1196 if (xpl->sadb_x_policy_type == IPSEC_POLICY_BYPASS) { 1197 error = kauth_authorize_network(cred, KAUTH_NETWORK_IPSEC, 1198 KAUTH_REQ_NETWORK_IPSEC_BYPASS, NULL, NULL, NULL); 1199 if (error) 1200 return error; 1201 } 1202 1203 /* allocation new SP entry */ 1204 if ((newsp = key_msg2sp(xpl, len, &error)) == NULL) 1205 return error; 1206 1207 key_init_sp(newsp); 1208 newsp->created = time_uptime; 1209 /* Insert the global list for SPs for sockets */ 1210 key_socksplist_add(newsp); 1211 1212 /* clear old SP and set new SP */ 1213 oldsp = *policy; 1214 *policy = newsp; 1215 ipsec_destroy_policy(oldsp); 1216 1217 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DUMP)) { 1218 printf("%s: new policy\n", __func__); 1219 kdebug_secpolicy(newsp); 1220 } 1221 1222 return 0; 1223 } 1224 1225 int 1226 ipsec_get_policy(void *inp, const void *request, size_t len, 1227 struct mbuf **mp) 1228 { 1229 struct inpcb_hdr *inph = (struct inpcb_hdr *)inp; 1230 const struct sadb_x_policy *xpl; 1231 struct secpolicy *policy; 1232 1233 /* sanity check. */ 1234 if (inph == NULL || request == NULL || mp == NULL) 1235 return EINVAL; 1236 KASSERT(inph->inph_sp != NULL); 1237 if (len < sizeof(*xpl)) 1238 return EINVAL; 1239 xpl = (const struct sadb_x_policy *)request; 1240 1241 /* select direction */ 1242 switch (xpl->sadb_x_policy_dir) { 1243 case IPSEC_DIR_INBOUND: 1244 policy = inph->inph_sp->sp_in; 1245 break; 1246 case IPSEC_DIR_OUTBOUND: 1247 policy = inph->inph_sp->sp_out; 1248 break; 1249 default: 1250 IPSECLOG(LOG_ERR, "invalid direction=%u\n", 1251 xpl->sadb_x_policy_dir); 1252 return EINVAL; 1253 } 1254 1255 if (policy == NULL) 1256 return EINVAL; 1257 1258 *mp = key_sp2msg(policy, M_NOWAIT); 1259 if (!*mp) { 1260 IPSECLOG(LOG_DEBUG, "No more memory.\n"); 1261 return ENOBUFS; 1262 } 1263 1264 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DUMP)) { 1265 kdebug_mbuf(__func__, *mp); 1266 } 1267 1268 return 0; 1269 } 1270 1271 int 1272 ipsec_delete_pcbpolicy(void *inp) 1273 { 1274 struct inpcb_hdr *inph = (struct inpcb_hdr *)inp; 1275 1276 KASSERT(inph != NULL); 1277 1278 if (inph->inph_sp == NULL) 1279 return 0; 1280 1281 if (inph->inph_sp->sp_in != NULL) 1282 ipsec_destroy_policy(inph->inph_sp->sp_in); 1283 1284 if (inph->inph_sp->sp_out != NULL) 1285 ipsec_destroy_policy(inph->inph_sp->sp_out); 1286 1287 ipsec_invalpcbcache(inph->inph_sp, IPSEC_DIR_ANY); 1288 1289 ipsec_delpcbpolicy(inph->inph_sp); 1290 inph->inph_sp = NULL; 1291 1292 return 0; 1293 } 1294 1295 /* 1296 * Return the current level (either IPSEC_LEVEL_USE or IPSEC_LEVEL_REQUIRE). 1297 */ 1298 u_int 1299 ipsec_get_reqlevel(const struct ipsecrequest *isr) 1300 { 1301 u_int level = 0; 1302 u_int esp_trans_deflev, esp_net_deflev; 1303 u_int ah_trans_deflev, ah_net_deflev; 1304 1305 KASSERT(isr != NULL); 1306 KASSERT(isr->sp != NULL); 1307 KASSERTMSG( 1308 isr->sp->spidx.src.sa.sa_family == isr->sp->spidx.dst.sa.sa_family, 1309 "af family mismatch, src %u, dst %u", 1310 isr->sp->spidx.src.sa.sa_family, isr->sp->spidx.dst.sa.sa_family); 1311 1312 /* XXX note that we have ipseclog() expanded here - code sync issue */ 1313 #define IPSEC_CHECK_DEFAULT(lev) \ 1314 (((lev) != IPSEC_LEVEL_USE && (lev) != IPSEC_LEVEL_REQUIRE \ 1315 && (lev) != IPSEC_LEVEL_UNIQUE) ? \ 1316 (ipsec_debug ? log(LOG_INFO, "fixed system default level " #lev \ 1317 ":%d->%d\n", (lev), IPSEC_LEVEL_REQUIRE) : (void)0), \ 1318 (lev) = IPSEC_LEVEL_REQUIRE, (lev) \ 1319 : (lev)) 1320 1321 /* set default level */ 1322 switch (((struct sockaddr *)&isr->sp->spidx.src)->sa_family) { 1323 #ifdef INET 1324 case AF_INET: 1325 esp_trans_deflev = IPSEC_CHECK_DEFAULT(ip4_esp_trans_deflev); 1326 esp_net_deflev = IPSEC_CHECK_DEFAULT(ip4_esp_net_deflev); 1327 ah_trans_deflev = IPSEC_CHECK_DEFAULT(ip4_ah_trans_deflev); 1328 ah_net_deflev = IPSEC_CHECK_DEFAULT(ip4_ah_net_deflev); 1329 break; 1330 #endif 1331 #ifdef INET6 1332 case AF_INET6: 1333 esp_trans_deflev = IPSEC_CHECK_DEFAULT(ip6_esp_trans_deflev); 1334 esp_net_deflev = IPSEC_CHECK_DEFAULT(ip6_esp_net_deflev); 1335 ah_trans_deflev = IPSEC_CHECK_DEFAULT(ip6_ah_trans_deflev); 1336 ah_net_deflev = IPSEC_CHECK_DEFAULT(ip6_ah_net_deflev); 1337 break; 1338 #endif 1339 default: 1340 panic("%s: unknown af %u", __func__, 1341 isr->sp->spidx.src.sa.sa_family); 1342 } 1343 1344 #undef IPSEC_CHECK_DEFAULT 1345 1346 /* set level */ 1347 switch (isr->level) { 1348 case IPSEC_LEVEL_DEFAULT: 1349 switch (isr->saidx.proto) { 1350 case IPPROTO_ESP: 1351 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) 1352 level = esp_net_deflev; 1353 else 1354 level = esp_trans_deflev; 1355 break; 1356 case IPPROTO_AH: 1357 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) 1358 level = ah_net_deflev; 1359 else 1360 level = ah_trans_deflev; 1361 break; 1362 case IPPROTO_IPCOMP: 1363 /* 1364 * we don't really care, as IPcomp document says that 1365 * we shouldn't compress small packets 1366 */ 1367 level = IPSEC_LEVEL_USE; 1368 break; 1369 default: 1370 panic("%s: Illegal protocol defined %u", __func__, 1371 isr->saidx.proto); 1372 } 1373 break; 1374 1375 case IPSEC_LEVEL_USE: 1376 case IPSEC_LEVEL_REQUIRE: 1377 level = isr->level; 1378 break; 1379 case IPSEC_LEVEL_UNIQUE: 1380 level = IPSEC_LEVEL_REQUIRE; 1381 break; 1382 1383 default: 1384 panic("%s: Illegal IPsec level %u", __func__, isr->level); 1385 } 1386 1387 return level; 1388 } 1389 1390 /* 1391 * Check security policy requirements against the actual packet contents. 1392 * 1393 * If the SP requires an IPsec packet, and the packet was neither AH nor ESP, 1394 * then kick it. 1395 */ 1396 static int 1397 ipsec_sp_reject(const struct secpolicy *sp, const struct mbuf *m) 1398 { 1399 struct ipsecrequest *isr; 1400 1401 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DATA)) { 1402 printf("%s: using SP\n", __func__); 1403 kdebug_secpolicy(sp); 1404 } 1405 1406 /* check policy */ 1407 switch (sp->policy) { 1408 case IPSEC_POLICY_DISCARD: 1409 return 1; 1410 case IPSEC_POLICY_BYPASS: 1411 case IPSEC_POLICY_NONE: 1412 return 0; 1413 } 1414 1415 KASSERTMSG(sp->policy == IPSEC_POLICY_IPSEC, 1416 "invalid policy %u", sp->policy); 1417 1418 /* XXX should compare policy against ipsec header history */ 1419 1420 for (isr = sp->req; isr != NULL; isr = isr->next) { 1421 if (ipsec_get_reqlevel(isr) != IPSEC_LEVEL_REQUIRE) 1422 continue; 1423 switch (isr->saidx.proto) { 1424 case IPPROTO_ESP: 1425 if ((m->m_flags & M_DECRYPTED) == 0) { 1426 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 1427 "ESP m_flags:%x\n", m->m_flags); 1428 return 1; 1429 } 1430 break; 1431 case IPPROTO_AH: 1432 if ((m->m_flags & M_AUTHIPHDR) == 0) { 1433 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 1434 "AH m_flags:%x\n", m->m_flags); 1435 return 1; 1436 } 1437 break; 1438 case IPPROTO_IPCOMP: 1439 /* 1440 * We don't really care, as IPcomp document 1441 * says that we shouldn't compress small 1442 * packets, IPComp policy should always be 1443 * treated as being in "use" level. 1444 */ 1445 break; 1446 } 1447 } 1448 1449 return 0; 1450 } 1451 1452 /* 1453 * Check security policy requirements. 1454 */ 1455 int 1456 ipsec_in_reject(struct mbuf *m, void *inp) 1457 { 1458 struct inpcb_hdr *inph = (struct inpcb_hdr *)inp; 1459 struct secpolicy *sp; 1460 int error; 1461 int result; 1462 1463 KASSERT(m != NULL); 1464 1465 if (inph == NULL) 1466 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND, 1467 IP_FORWARDING, &error); 1468 else 1469 sp = ipsec_getpolicybysock(m, IPSEC_DIR_INBOUND, 1470 inph, &error); 1471 1472 if (sp != NULL) { 1473 result = ipsec_sp_reject(sp, m); 1474 if (result) 1475 IPSEC_STATINC(IPSEC_STAT_IN_POLVIO); 1476 KEY_SP_UNREF(&sp); 1477 } else { 1478 result = 0; 1479 } 1480 return result; 1481 } 1482 1483 /* 1484 * Compute the byte size to be occupied by the IPsec header. If it is 1485 * tunneled, it includes the size of outer IP header. 1486 */ 1487 static size_t 1488 ipsec_sp_hdrsiz(const struct secpolicy *sp, const struct mbuf *m) 1489 { 1490 struct ipsecrequest *isr; 1491 size_t siz; 1492 1493 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DATA)) { 1494 printf("%s: using SP\n", __func__); 1495 kdebug_secpolicy(sp); 1496 } 1497 1498 switch (sp->policy) { 1499 case IPSEC_POLICY_DISCARD: 1500 case IPSEC_POLICY_BYPASS: 1501 case IPSEC_POLICY_NONE: 1502 return 0; 1503 } 1504 1505 KASSERTMSG(sp->policy == IPSEC_POLICY_IPSEC, 1506 "invalid policy %u", sp->policy); 1507 1508 siz = 0; 1509 for (isr = sp->req; isr != NULL; isr = isr->next) { 1510 size_t clen = 0; 1511 struct secasvar *sav; 1512 1513 switch (isr->saidx.proto) { 1514 case IPPROTO_ESP: 1515 sav = ipsec_lookup_sa(isr, m); 1516 if (sav != NULL) { 1517 clen = esp_hdrsiz(sav); 1518 KEY_SA_UNREF(&sav); 1519 } else 1520 clen = esp_hdrsiz(NULL); 1521 break; 1522 case IPPROTO_AH: 1523 sav = ipsec_lookup_sa(isr, m); 1524 if (sav != NULL) { 1525 clen = ah_hdrsiz(sav); 1526 KEY_SA_UNREF(&sav); 1527 } else 1528 clen = ah_hdrsiz(NULL); 1529 break; 1530 case IPPROTO_IPCOMP: 1531 clen = sizeof(struct ipcomp); 1532 break; 1533 } 1534 1535 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) { 1536 switch (isr->saidx.dst.sa.sa_family) { 1537 case AF_INET: 1538 clen += sizeof(struct ip); 1539 break; 1540 #ifdef INET6 1541 case AF_INET6: 1542 clen += sizeof(struct ip6_hdr); 1543 break; 1544 #endif 1545 default: 1546 IPSECLOG(LOG_ERR, "unknown AF %d in " 1547 "IPsec tunnel SA\n", 1548 ((const struct sockaddr *)&isr->saidx.dst) 1549 ->sa_family); 1550 break; 1551 } 1552 } 1553 siz += clen; 1554 } 1555 1556 return siz; 1557 } 1558 1559 size_t 1560 ipsec_hdrsiz(struct mbuf *m, u_int dir, void *inp) 1561 { 1562 struct inpcb_hdr *inph = (struct inpcb_hdr *)inp; 1563 struct secpolicy *sp; 1564 int error; 1565 size_t size; 1566 1567 KASSERT(m != NULL); 1568 KASSERTMSG(inph == NULL || inph->inph_socket != NULL, 1569 "socket w/o inpcb"); 1570 1571 if (inph == NULL) 1572 sp = ipsec_getpolicybyaddr(m, dir, IP_FORWARDING, &error); 1573 else 1574 sp = ipsec_getpolicybysock(m, dir, inph, &error); 1575 1576 if (sp != NULL) { 1577 size = ipsec_sp_hdrsiz(sp, m); 1578 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DATA, "size:%zu.\n", size); 1579 KEY_SP_UNREF(&sp); 1580 } else { 1581 size = 0; 1582 } 1583 1584 return size; 1585 } 1586 1587 /* 1588 * Check the variable replay window. 1589 * ipsec_chkreplay() performs replay check before ICV verification. 1590 * ipsec_updatereplay() updates replay bitmap. This must be called after 1591 * ICV verification (it also performs replay check, which is usually done 1592 * beforehand). 1593 * 0 (zero) is returned if packet disallowed, 1 if packet permitted. 1594 * 1595 * based on RFC 2401. 1596 */ 1597 int 1598 ipsec_chkreplay(u_int32_t seq, const struct secasvar *sav) 1599 { 1600 const struct secreplay *replay; 1601 u_int32_t diff; 1602 int fr; 1603 u_int32_t wsizeb; /* constant: bits of window size */ 1604 int frlast; /* constant: last frame */ 1605 1606 KASSERT(sav != NULL); 1607 KASSERT(sav->replay != NULL); 1608 1609 replay = sav->replay; 1610 1611 if (replay->wsize == 0) 1612 return 1; /* no need to check replay. */ 1613 1614 /* constant */ 1615 frlast = replay->wsize - 1; 1616 wsizeb = replay->wsize << 3; 1617 1618 /* sequence number of 0 is invalid */ 1619 if (seq == 0) 1620 return 0; 1621 1622 /* first time is always okay */ 1623 if (replay->count == 0) 1624 return 1; 1625 1626 if (seq > replay->lastseq) { 1627 /* larger sequences are okay */ 1628 return 1; 1629 } else { 1630 /* seq is equal or less than lastseq. */ 1631 diff = replay->lastseq - seq; 1632 1633 /* over range to check, i.e. too old or wrapped */ 1634 if (diff >= wsizeb) 1635 return 0; 1636 1637 fr = frlast - diff / 8; 1638 1639 /* this packet already seen ? */ 1640 if ((replay->bitmap)[fr] & (1 << (diff % 8))) 1641 return 0; 1642 1643 /* out of order but good */ 1644 return 1; 1645 } 1646 } 1647 1648 /* 1649 * check replay counter whether to update or not. 1650 * OUT: 0: OK 1651 * 1: NG 1652 */ 1653 int 1654 ipsec_updatereplay(u_int32_t seq, const struct secasvar *sav) 1655 { 1656 struct secreplay *replay; 1657 u_int32_t diff; 1658 int fr; 1659 u_int32_t wsizeb; /* constant: bits of window size */ 1660 int frlast; /* constant: last frame */ 1661 1662 KASSERT(sav != NULL); 1663 KASSERT(sav->replay != NULL); 1664 1665 replay = sav->replay; 1666 1667 if (replay->wsize == 0) 1668 goto ok; /* no need to check replay. */ 1669 1670 /* constant */ 1671 frlast = replay->wsize - 1; 1672 wsizeb = replay->wsize << 3; 1673 1674 /* sequence number of 0 is invalid */ 1675 if (seq == 0) 1676 return 1; 1677 1678 /* first time */ 1679 if (replay->count == 0) { 1680 replay->lastseq = seq; 1681 memset(replay->bitmap, 0, replay->wsize); 1682 (replay->bitmap)[frlast] = 1; 1683 goto ok; 1684 } 1685 1686 if (seq > replay->lastseq) { 1687 /* seq is larger than lastseq. */ 1688 diff = seq - replay->lastseq; 1689 1690 /* new larger sequence number */ 1691 if (diff < wsizeb) { 1692 /* In window */ 1693 /* set bit for this packet */ 1694 vshiftl(replay->bitmap, diff, replay->wsize); 1695 (replay->bitmap)[frlast] |= 1; 1696 } else { 1697 /* this packet has a "way larger" */ 1698 memset(replay->bitmap, 0, replay->wsize); 1699 (replay->bitmap)[frlast] = 1; 1700 } 1701 replay->lastseq = seq; 1702 1703 /* larger is good */ 1704 } else { 1705 /* seq is equal or less than lastseq. */ 1706 diff = replay->lastseq - seq; 1707 1708 /* over range to check, i.e. too old or wrapped */ 1709 if (diff >= wsizeb) 1710 return 1; 1711 1712 fr = frlast - diff / 8; 1713 1714 /* this packet already seen ? */ 1715 if ((replay->bitmap)[fr] & (1 << (diff % 8))) 1716 return 1; 1717 1718 /* mark as seen */ 1719 (replay->bitmap)[fr] |= (1 << (diff % 8)); 1720 1721 /* out of order but good */ 1722 } 1723 1724 ok: 1725 if (replay->count == ~0) { 1726 char buf[IPSEC_LOGSASTRLEN]; 1727 1728 /* set overflow flag */ 1729 replay->overflow++; 1730 1731 /* don't increment, no more packets accepted */ 1732 if ((sav->flags & SADB_X_EXT_CYCSEQ) == 0) 1733 return 1; 1734 1735 IPSECLOG(LOG_WARNING, "replay counter made %d cycle. %s\n", 1736 replay->overflow, ipsec_logsastr(sav, buf, sizeof(buf))); 1737 } 1738 1739 replay->count++; 1740 1741 return 0; 1742 } 1743 1744 /* 1745 * shift variable length buffer to left. 1746 * IN: bitmap: pointer to the buffer 1747 * nbit: the number of to shift. 1748 * wsize: buffer size (bytes). 1749 */ 1750 static void 1751 vshiftl(unsigned char *bitmap, int nbit, int wsize) 1752 { 1753 int s, j, i; 1754 unsigned char over; 1755 1756 for (j = 0; j < nbit; j += 8) { 1757 s = (nbit - j < 8) ? (nbit - j): 8; 1758 bitmap[0] <<= s; 1759 for (i = 1; i < wsize; i++) { 1760 over = (bitmap[i] >> (8 - s)); 1761 bitmap[i] <<= s; 1762 bitmap[i-1] |= over; 1763 } 1764 } 1765 1766 return; 1767 } 1768 1769 /* Return a printable string for the address. */ 1770 const char * 1771 ipsec_address(const union sockaddr_union *sa, char *buf, size_t size) 1772 { 1773 switch (sa->sa.sa_family) { 1774 case AF_INET: 1775 in_print(buf, size, &sa->sin.sin_addr); 1776 return buf; 1777 #if INET6 1778 case AF_INET6: 1779 in6_print(buf, size, &sa->sin6.sin6_addr); 1780 return buf; 1781 #endif 1782 default: 1783 return "(unknown address family)"; 1784 } 1785 } 1786 1787 const char * 1788 ipsec_logsastr(const struct secasvar *sav, char *buf, size_t size) 1789 { 1790 const struct secasindex *saidx = &sav->sah->saidx; 1791 char sbuf[IPSEC_ADDRSTRLEN], dbuf[IPSEC_ADDRSTRLEN]; 1792 1793 KASSERTMSG(saidx->src.sa.sa_family == saidx->dst.sa.sa_family, 1794 "af family mismatch, src %u, dst %u", 1795 saidx->src.sa.sa_family, saidx->dst.sa.sa_family); 1796 1797 snprintf(buf, size, "SA(SPI=%u src=%s dst=%s)", 1798 (u_int32_t)ntohl(sav->spi), 1799 ipsec_address(&saidx->src, sbuf, sizeof(sbuf)), 1800 ipsec_address(&saidx->dst, dbuf, sizeof(dbuf))); 1801 1802 return buf; 1803 } 1804 1805 #ifdef INET6 1806 struct secpolicy * 1807 ipsec6_check_policy(struct mbuf *m, struct in6pcb *in6p, int flags, 1808 int *needipsecp, int *errorp) 1809 { 1810 struct secpolicy *sp = NULL; 1811 int s; 1812 int error = 0; 1813 int needipsec = 0; 1814 1815 if (ipsec_outdone(m)) { 1816 goto skippolicycheck; 1817 } 1818 s = splsoftnet(); 1819 if (in6p && ipsec_pcb_skip_ipsec(in6p->in6p_sp, IPSEC_DIR_OUTBOUND)) { 1820 splx(s); 1821 goto skippolicycheck; 1822 } 1823 sp = ipsec_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags, &error, in6p); 1824 splx(s); 1825 1826 /* 1827 * There are four return cases: 1828 * sp != NULL apply IPsec policy 1829 * sp == NULL, error == 0 no IPsec handling needed 1830 * sp == NULL, error == -EINVAL discard packet w/o error 1831 * sp == NULL, error != 0 discard packet, report error 1832 */ 1833 if (sp == NULL) { 1834 needipsec = 0; 1835 } else { 1836 needipsec = 1; 1837 } 1838 1839 skippolicycheck: 1840 *errorp = error; 1841 *needipsecp = needipsec; 1842 return sp; 1843 } 1844 1845 /* 1846 * calculate UDP checksum for UDP encapsulated ESP for IPv6. 1847 * 1848 * RFC2460(Internet Protocol, Version 6 Specification) says: 1849 * 1850 * IPv6 receivers MUST discard UDP packets with a zero checksum. 1851 * 1852 * There is more relaxed specification RFC6935(IPv6 and UDP Checksums for 1853 * Tunneled Packets). The document allows zero checksum. It's too 1854 * late to publish, there are a lot of interoperability problems... 1855 */ 1856 void 1857 ipsec6_udp_cksum(struct mbuf *m) 1858 { 1859 struct ip6_hdr *ip6; 1860 uint16_t plen, uh_sum; 1861 int off; 1862 1863 /* must called after m_pullup() */ 1864 KASSERT(m->m_len >= sizeof(struct ip6_hdr)); 1865 1866 ip6 = mtod(m, struct ip6_hdr *); 1867 KASSERT(ip6->ip6_nxt == IPPROTO_UDP); 1868 1869 /* ip6->ip6_plen can not be updated before ip6_output() */ 1870 plen = m->m_pkthdr.len - sizeof(*ip6); 1871 KASSERT(plen >= sizeof(struct udphdr)); 1872 1873 uh_sum = in6_cksum(m, IPPROTO_UDP, sizeof(*ip6), plen); 1874 if (uh_sum == 0) 1875 uh_sum = 0xffff; 1876 1877 off = sizeof(*ip6) + offsetof(struct udphdr, uh_sum); 1878 m_copyback(m, off, sizeof(uh_sum), (void *)&uh_sum); 1879 } 1880 #endif /* INET6 */ 1881 1882 /* 1883 * ----------------------------------------------------------------------------- 1884 */ 1885 1886 /* XXX this stuff doesn't belong here... */ 1887 1888 static struct xformsw *xforms = NULL; 1889 1890 /* 1891 * Register a transform; typically at system startup. 1892 */ 1893 void 1894 xform_register(struct xformsw *xsp) 1895 { 1896 xsp->xf_next = xforms; 1897 xforms = xsp; 1898 } 1899 1900 /* 1901 * Initialize transform support in an sav. 1902 */ 1903 int 1904 xform_init(struct secasvar *sav, int xftype) 1905 { 1906 struct xformsw *xsp; 1907 1908 if (sav->tdb_xform != NULL) /* previously initialized */ 1909 return 0; 1910 for (xsp = xforms; xsp; xsp = xsp->xf_next) 1911 if (xsp->xf_type == xftype) 1912 return (*xsp->xf_init)(sav, xsp); 1913 1914 IPSECLOG(LOG_DEBUG, "no match for xform type %d\n", xftype); 1915 return EINVAL; 1916 } 1917 1918 /* 1919 * XXXJRT This should be done as a protosw init call. 1920 */ 1921 void 1922 ipsec_attach(void) 1923 { 1924 1925 ipsec_output_init(); 1926 1927 ipsecstat_percpu = percpu_alloc(sizeof(uint64_t) * IPSEC_NSTATS); 1928 1929 sysctl_net_inet_ipsec_setup(NULL); 1930 #ifdef INET6 1931 sysctl_net_inet6_ipsec6_setup(NULL); 1932 #endif 1933 1934 ah_attach(); 1935 esp_attach(); 1936 ipcomp_attach(); 1937 ipe4_attach(); 1938 #ifdef TCP_SIGNATURE 1939 tcpsignature_attach(); 1940 #endif 1941 } 1942