1 /* $NetBSD: ipsec.c,v 1.179 2024/05/13 00:12:33 msaitoh 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 1.179 2024/05/13 00:12:33 msaitoh 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 *, 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 *, struct inpcb *); 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(inp_locked(pcbsp->sp_inp)); 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 inpcb_connect(). 248 */ 249 } 250 251 key_sp_touch(sp); 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(inp_locked(pcbsp->sp_inp)); 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(inp_locked(pcbsp->sp_inp)); 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(inp_locked(pcbsp->sp_inp)); 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(inp_locked(pcbsp->sp_inp)); 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 *inp, 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(inp != NULL); 412 KASSERT(error != NULL); 413 KASSERTMSG(IPSEC_DIR_IS_INOROUT(dir), "invalid direction %u", dir); 414 415 KASSERT(inp->inp_socket != NULL); 416 KASSERT(inp_locked(inp)); 417 418 /* XXX FIXME inpcb vs socket*/ 419 af = inp->inp_af; 420 KASSERTMSG(af == AF_INET || af == AF_INET6, 421 "unexpected protocol family %u", af); 422 423 KASSERT(inp->inp_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, inp->inp_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, inp); 439 pcbsp = inp->inp_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-privileged 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, 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 struct inpcb *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 KASSERT(inp->inp_socket != NULL); 579 sp = ipsec_getpolicybysock(m, dir, inp, error); 580 } 581 if (sp == NULL) { 582 KASSERTMSG(*error != 0, "getpolicy failed w/o error"); 583 IPSEC_STATINC(IPSEC_STAT_OUT_INVAL); 584 return NULL; 585 } 586 KASSERTMSG(*error == 0, "sp w/ error set to %u", *error); 587 588 switch (sp->policy) { 589 case IPSEC_POLICY_ENTRUST: 590 default: 591 printf("%s: invalid policy %u\n", __func__, sp->policy); 592 /* fall thru... */ 593 case IPSEC_POLICY_DISCARD: 594 IPSEC_STATINC(IPSEC_STAT_OUT_POLVIO); 595 *error = -EINVAL; /* packet is discarded by caller */ 596 break; 597 case IPSEC_POLICY_BYPASS: 598 case IPSEC_POLICY_NONE: 599 KEY_SP_UNREF(&sp); 600 sp = NULL; /* NB: force NULL result */ 601 break; 602 case IPSEC_POLICY_IPSEC: 603 KASSERT(sp->req != NULL); 604 break; 605 } 606 607 if (*error != 0) { 608 KEY_SP_UNREF(&sp); 609 sp = NULL; 610 IPSECLOG(LOG_DEBUG, "done, error %d\n", *error); 611 } 612 613 return sp; 614 } 615 616 int 617 ipsec4_output(struct mbuf *m, struct inpcb *inp, int flags, 618 u_long *mtu, bool *natt_frag, bool *done, bool *count_drop) 619 { 620 struct secpolicy *sp = NULL; 621 u_long _mtu = 0; 622 int error; 623 624 /* 625 * Check the security policy (SP) for the packet and, if required, 626 * do IPsec-related processing. There are two cases here; the first 627 * time a packet is sent through it will be untagged and handled by 628 * ipsec_checkpolicy(). If the packet is resubmitted to ip_output 629 * (e.g. after AH, ESP, etc. processing), there will be a tag to 630 * bypass the lookup and related policy checking. 631 */ 632 if (ipsec_outdone(m)) { 633 return 0; 634 } 635 if (inp && ipsec_pcb_skip_ipsec(inp->inp_sp, IPSEC_DIR_OUTBOUND)) { 636 return 0; 637 } 638 sp = ipsec_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags, &error, inp); 639 640 /* 641 * There are four return cases: 642 * sp != NULL apply IPsec policy 643 * sp == NULL, error == 0 no IPsec handling needed 644 * sp == NULL, error == -EINVAL discard packet w/o error 645 * sp == NULL, error != 0 discard packet, report error 646 */ 647 if (sp == NULL) { 648 if (error) { 649 /* 650 * Hack: -EINVAL is used to signal that a packet 651 * should be silently discarded. This is typically 652 * because we asked key management for an SA and 653 * it was delayed (e.g. kicked up to IKE). 654 */ 655 if (error == -EINVAL) 656 error = 0; 657 m_freem(m); 658 *done = true; 659 *count_drop = true; 660 return error; 661 } 662 /* No IPsec processing for this packet. */ 663 return 0; 664 } 665 666 /* 667 * Do delayed checksums now because we send before 668 * this is done in the normal processing path. 669 */ 670 if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 671 in_undefer_cksum_tcpudp(m); 672 m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 673 } 674 675 error = ipsec4_process_packet(m, sp->req, &_mtu); 676 if (error == 0 && _mtu != 0) { 677 /* 678 * NAT-T ESP fragmentation: do not do IPSec processing 679 * now, we will do it on each fragmented packet. 680 */ 681 *mtu = _mtu; 682 *natt_frag = true; 683 KEY_SP_UNREF(&sp); 684 return 0; 685 } 686 687 /* 688 * Preserve KAME behaviour: ENOENT can be returned 689 * when an SA acquire is in progress. Don't propagate 690 * this to user-level; it confuses applications. 691 * 692 * XXX this will go away when the SADB is redone. 693 */ 694 if (error == ENOENT) 695 error = 0; 696 KEY_SP_UNREF(&sp); 697 *done = true; 698 return error; 699 } 700 701 int 702 ipsec_ip_input_checkpolicy(struct mbuf *m, bool forward) 703 { 704 struct secpolicy *sp; 705 int error; 706 707 error = ipsec_in_reject(m, NULL); 708 if (error) { 709 return EINVAL; 710 } 711 712 if (!forward || !(m->m_flags & M_CANFASTFWD)) { 713 return 0; 714 } 715 716 /* 717 * Peek at the outbound SP for this packet to determine if 718 * it is a Fast Forward candidate. 719 */ 720 sp = ipsec_checkpolicy(m, IPSEC_DIR_OUTBOUND, IP_FORWARDING, 721 &error, NULL); 722 if (sp != NULL) { 723 m->m_flags &= ~M_CANFASTFWD; 724 KEY_SP_UNREF(&sp); 725 } 726 727 return 0; 728 } 729 730 /* 731 * If the packet is routed over IPsec tunnel, tell the originator the 732 * tunnel MTU. 733 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz 734 * 735 * XXX: Quick hack!!! 736 * 737 * XXX: And what if the MTU goes negative? 738 */ 739 void 740 ipsec_mtu(struct mbuf *m, int *destmtu) 741 { 742 struct secpolicy *sp; 743 size_t ipsechdr; 744 int error; 745 746 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, IP_FORWARDING, 747 &error); 748 if (sp == NULL) { 749 return; 750 } 751 752 /* Count IPsec header size. */ 753 ipsechdr = ipsec_sp_hdrsiz(sp, m); 754 755 /* 756 * Find the correct route for outer IP header, compute tunnel MTU. 757 */ 758 if (sp->req) { 759 struct secasvar *sav; 760 761 sav = ipsec_lookup_sa(sp->req, m); 762 if (sav != NULL) { 763 struct route *ro; 764 struct rtentry *rt; 765 766 ro = &sav->sah->sa_route; 767 rt = rtcache_validate(ro); 768 if (rt && rt->rt_ifp) { 769 *destmtu = rt->rt_rmx.rmx_mtu ? 770 rt->rt_rmx.rmx_mtu : rt->rt_ifp->if_mtu; 771 *destmtu -= ipsechdr; 772 } 773 rtcache_unref(rt, ro); 774 KEY_SA_UNREF(&sav); 775 } 776 } 777 KEY_SP_UNREF(&sp); 778 } 779 780 static int 781 ipsec_setspidx_inpcb(struct mbuf *m, struct inpcb *inp) 782 { 783 int error; 784 785 KASSERT(inp != NULL); 786 KASSERT(inp->inp_sp != NULL); 787 KASSERT(inp->inp_sp->sp_out != NULL); 788 KASSERT(inp->inp_sp->sp_in != NULL); 789 790 error = ipsec_setspidx(m, &inp->inp_sp->sp_in->spidx, 791 IPSEC_DIR_INBOUND, 1); 792 if (error == 0) { 793 inp->inp_sp->sp_out->spidx = inp->inp_sp->sp_in->spidx; 794 inp->inp_sp->sp_out->spidx.dir = IPSEC_DIR_OUTBOUND; 795 } else { 796 memset(&inp->inp_sp->sp_in->spidx, 0, 797 sizeof(inp->inp_sp->sp_in->spidx)); 798 memset(&inp->inp_sp->sp_out->spidx, 0, 799 sizeof(inp->inp_sp->sp_out->spidx)); 800 } 801 return error; 802 } 803 804 /* 805 * configure security policy index (src/dst/proto/sport/dport) 806 * by looking at the content of mbuf. 807 * the caller is responsible for error recovery (like clearing up spidx). 808 */ 809 static int 810 ipsec_setspidx(struct mbuf *m, struct secpolicyindex *spidx, int dir, 811 int needport) 812 { 813 struct ip *ip = NULL; 814 struct ip ipbuf; 815 u_int v; 816 int error; 817 818 KASSERT(m != NULL); 819 M_VERIFY_PACKET(m); 820 821 if (m->m_pkthdr.len < sizeof(struct ip)) { 822 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 823 "pkthdr.len(%d) < sizeof(struct ip), ignored.\n", 824 m->m_pkthdr.len); 825 return EINVAL; 826 } 827 828 memset(spidx, 0, sizeof(*spidx)); 829 spidx->dir = dir; 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(struct inpcb *inp, const void *request, size_t len, 1137 kauth_cred_t cred) 1138 { 1139 const struct sadb_x_policy *xpl; 1140 struct secpolicy *newsp, *oldsp; 1141 struct secpolicy **policy; 1142 int error; 1143 1144 KASSERT(!cpu_softintr_p()); 1145 KASSERT(inp != NULL); 1146 KASSERT(inp_locked(inp)); 1147 KASSERT(request != NULL); 1148 1149 if (len < sizeof(*xpl)) 1150 return EINVAL; 1151 xpl = (const struct sadb_x_policy *)request; 1152 1153 KASSERT(inp->inp_sp != NULL); 1154 1155 /* select direction */ 1156 switch (xpl->sadb_x_policy_dir) { 1157 case IPSEC_DIR_INBOUND: 1158 policy = &inp->inp_sp->sp_in; 1159 break; 1160 case IPSEC_DIR_OUTBOUND: 1161 policy = &inp->inp_sp->sp_out; 1162 break; 1163 default: 1164 IPSECLOG(LOG_ERR, "invalid direction=%u\n", 1165 xpl->sadb_x_policy_dir); 1166 return EINVAL; 1167 } 1168 1169 /* sanity check. */ 1170 if (policy == NULL || *policy == NULL) 1171 return EINVAL; 1172 1173 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DUMP)) { 1174 kdebug_sadb_xpolicy("set passed policy", request); 1175 } 1176 1177 /* check policy type */ 1178 /* ipsec_set_policy() accepts IPSEC, ENTRUST and BYPASS. */ 1179 if (xpl->sadb_x_policy_type == IPSEC_POLICY_DISCARD || 1180 xpl->sadb_x_policy_type == IPSEC_POLICY_NONE) 1181 return EINVAL; 1182 1183 /* check privileged socket */ 1184 if (xpl->sadb_x_policy_type == IPSEC_POLICY_BYPASS) { 1185 error = kauth_authorize_network(cred, KAUTH_NETWORK_IPSEC, 1186 KAUTH_REQ_NETWORK_IPSEC_BYPASS, NULL, NULL, NULL); 1187 if (error) 1188 return error; 1189 } 1190 1191 /* allocation new SP entry */ 1192 if ((newsp = key_msg2sp(xpl, len, &error)) == NULL) 1193 return error; 1194 1195 key_init_sp(newsp); 1196 newsp->created = time_uptime; 1197 /* Insert the global list for SPs for sockets */ 1198 key_socksplist_add(newsp); 1199 1200 /* clear old SP and set new SP */ 1201 oldsp = *policy; 1202 *policy = newsp; 1203 ipsec_destroy_policy(oldsp); 1204 1205 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DUMP)) { 1206 printf("%s: new policy\n", __func__); 1207 kdebug_secpolicy(newsp); 1208 } 1209 1210 return 0; 1211 } 1212 1213 int 1214 ipsec_get_policy(struct inpcb *inp, const void *request, size_t len, 1215 struct mbuf **mp) 1216 { 1217 const struct sadb_x_policy *xpl; 1218 struct secpolicy *policy; 1219 1220 /* sanity check. */ 1221 if (inp == NULL || request == NULL || mp == NULL) 1222 return EINVAL; 1223 KASSERT(inp->inp_sp != NULL); 1224 if (len < sizeof(*xpl)) 1225 return EINVAL; 1226 xpl = (const struct sadb_x_policy *)request; 1227 1228 /* select direction */ 1229 switch (xpl->sadb_x_policy_dir) { 1230 case IPSEC_DIR_INBOUND: 1231 policy = inp->inp_sp->sp_in; 1232 break; 1233 case IPSEC_DIR_OUTBOUND: 1234 policy = inp->inp_sp->sp_out; 1235 break; 1236 default: 1237 IPSECLOG(LOG_ERR, "invalid direction=%u\n", 1238 xpl->sadb_x_policy_dir); 1239 return EINVAL; 1240 } 1241 1242 if (policy == NULL) 1243 return EINVAL; 1244 1245 *mp = key_sp2msg(policy, M_NOWAIT); 1246 if (!*mp) { 1247 IPSECLOG(LOG_DEBUG, "No more memory.\n"); 1248 return ENOBUFS; 1249 } 1250 1251 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DUMP)) { 1252 kdebug_mbuf(__func__, *mp); 1253 } 1254 1255 return 0; 1256 } 1257 1258 int 1259 ipsec_delete_pcbpolicy(struct inpcb *inp) 1260 { 1261 1262 KASSERT(inp != NULL); 1263 1264 if (inp->inp_sp == NULL) 1265 return 0; 1266 1267 if (inp->inp_sp->sp_in != NULL) 1268 ipsec_destroy_policy(inp->inp_sp->sp_in); 1269 1270 if (inp->inp_sp->sp_out != NULL) 1271 ipsec_destroy_policy(inp->inp_sp->sp_out); 1272 1273 ipsec_invalpcbcache(inp->inp_sp, IPSEC_DIR_ANY); 1274 1275 ipsec_delpcbpolicy(inp->inp_sp); 1276 inp->inp_sp = NULL; 1277 1278 return 0; 1279 } 1280 1281 /* 1282 * Return the current level (either IPSEC_LEVEL_USE or IPSEC_LEVEL_REQUIRE). 1283 */ 1284 u_int 1285 ipsec_get_reqlevel(const struct ipsecrequest *isr) 1286 { 1287 u_int level = 0; 1288 u_int esp_trans_deflev, esp_net_deflev; 1289 u_int ah_trans_deflev, ah_net_deflev; 1290 1291 KASSERT(isr != NULL); 1292 KASSERT(isr->sp != NULL); 1293 KASSERTMSG( 1294 isr->sp->spidx.src.sa.sa_family == isr->sp->spidx.dst.sa.sa_family, 1295 "af family mismatch, src %u, dst %u", 1296 isr->sp->spidx.src.sa.sa_family, isr->sp->spidx.dst.sa.sa_family); 1297 1298 /* XXX note that we have ipseclog() expanded here - code sync issue */ 1299 #define IPSEC_CHECK_DEFAULT(lev) \ 1300 (((lev) != IPSEC_LEVEL_USE && (lev) != IPSEC_LEVEL_REQUIRE \ 1301 && (lev) != IPSEC_LEVEL_UNIQUE) ? \ 1302 (ipsec_debug ? log(LOG_INFO, "fixed system default level " #lev \ 1303 ":%d->%d\n", (lev), IPSEC_LEVEL_REQUIRE) : (void)0), \ 1304 (lev) = IPSEC_LEVEL_REQUIRE, (lev) \ 1305 : (lev)) 1306 1307 /* set default level */ 1308 switch (((struct sockaddr *)&isr->sp->spidx.src)->sa_family) { 1309 #ifdef INET 1310 case AF_INET: 1311 esp_trans_deflev = IPSEC_CHECK_DEFAULT(ip4_esp_trans_deflev); 1312 esp_net_deflev = IPSEC_CHECK_DEFAULT(ip4_esp_net_deflev); 1313 ah_trans_deflev = IPSEC_CHECK_DEFAULT(ip4_ah_trans_deflev); 1314 ah_net_deflev = IPSEC_CHECK_DEFAULT(ip4_ah_net_deflev); 1315 break; 1316 #endif 1317 #ifdef INET6 1318 case AF_INET6: 1319 esp_trans_deflev = IPSEC_CHECK_DEFAULT(ip6_esp_trans_deflev); 1320 esp_net_deflev = IPSEC_CHECK_DEFAULT(ip6_esp_net_deflev); 1321 ah_trans_deflev = IPSEC_CHECK_DEFAULT(ip6_ah_trans_deflev); 1322 ah_net_deflev = IPSEC_CHECK_DEFAULT(ip6_ah_net_deflev); 1323 break; 1324 #endif 1325 default: 1326 panic("%s: unknown af %u", __func__, 1327 isr->sp->spidx.src.sa.sa_family); 1328 } 1329 1330 #undef IPSEC_CHECK_DEFAULT 1331 1332 /* set level */ 1333 switch (isr->level) { 1334 case IPSEC_LEVEL_DEFAULT: 1335 switch (isr->saidx.proto) { 1336 case IPPROTO_ESP: 1337 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) 1338 level = esp_net_deflev; 1339 else 1340 level = esp_trans_deflev; 1341 break; 1342 case IPPROTO_AH: 1343 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) 1344 level = ah_net_deflev; 1345 else 1346 level = ah_trans_deflev; 1347 break; 1348 case IPPROTO_IPCOMP: 1349 /* 1350 * we don't really care, as IPcomp document says that 1351 * we shouldn't compress small packets 1352 */ 1353 level = IPSEC_LEVEL_USE; 1354 break; 1355 default: 1356 panic("%s: Illegal protocol defined %u", __func__, 1357 isr->saidx.proto); 1358 } 1359 break; 1360 1361 case IPSEC_LEVEL_USE: 1362 case IPSEC_LEVEL_REQUIRE: 1363 level = isr->level; 1364 break; 1365 case IPSEC_LEVEL_UNIQUE: 1366 level = IPSEC_LEVEL_REQUIRE; 1367 break; 1368 1369 default: 1370 panic("%s: Illegal IPsec level %u", __func__, isr->level); 1371 } 1372 1373 return level; 1374 } 1375 1376 /* 1377 * Check security policy requirements against the actual packet contents. 1378 * 1379 * If the SP requires an IPsec packet, and the packet was neither AH nor ESP, 1380 * then kick it. 1381 */ 1382 static int 1383 ipsec_sp_reject(const struct secpolicy *sp, const struct mbuf *m) 1384 { 1385 struct ipsecrequest *isr; 1386 1387 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DATA)) { 1388 printf("%s: using SP\n", __func__); 1389 kdebug_secpolicy(sp); 1390 } 1391 1392 /* check policy */ 1393 switch (sp->policy) { 1394 case IPSEC_POLICY_DISCARD: 1395 return 1; 1396 case IPSEC_POLICY_BYPASS: 1397 case IPSEC_POLICY_NONE: 1398 return 0; 1399 } 1400 1401 KASSERTMSG(sp->policy == IPSEC_POLICY_IPSEC, 1402 "invalid policy %u", sp->policy); 1403 1404 /* XXX should compare policy against ipsec header history */ 1405 1406 for (isr = sp->req; isr != NULL; isr = isr->next) { 1407 if (ipsec_get_reqlevel(isr) != IPSEC_LEVEL_REQUIRE) 1408 continue; 1409 switch (isr->saidx.proto) { 1410 case IPPROTO_ESP: 1411 if ((m->m_flags & M_DECRYPTED) == 0) { 1412 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 1413 "ESP m_flags:%x\n", m->m_flags); 1414 return 1; 1415 } 1416 break; 1417 case IPPROTO_AH: 1418 if ((m->m_flags & M_AUTHIPHDR) == 0) { 1419 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 1420 "AH m_flags:%x\n", m->m_flags); 1421 return 1; 1422 } 1423 break; 1424 case IPPROTO_IPCOMP: 1425 /* 1426 * We don't really care, as IPcomp document 1427 * says that we shouldn't compress small 1428 * packets, IPComp policy should always be 1429 * treated as being in "use" level. 1430 */ 1431 break; 1432 } 1433 } 1434 1435 return 0; 1436 } 1437 1438 /* 1439 * Check security policy requirements. 1440 */ 1441 int 1442 ipsec_in_reject(struct mbuf *m, struct inpcb *inp) 1443 { 1444 struct secpolicy *sp; 1445 int error; 1446 int result; 1447 1448 KASSERT(m != NULL); 1449 1450 if (inp == NULL) 1451 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND, 1452 IP_FORWARDING, &error); 1453 else 1454 sp = ipsec_getpolicybysock(m, IPSEC_DIR_INBOUND, 1455 inp, &error); 1456 1457 if (sp != NULL) { 1458 result = ipsec_sp_reject(sp, m); 1459 if (result) 1460 IPSEC_STATINC(IPSEC_STAT_IN_POLVIO); 1461 KEY_SP_UNREF(&sp); 1462 } else { 1463 result = 0; 1464 } 1465 return result; 1466 } 1467 1468 /* 1469 * Compute the byte size to be occupied by the IPsec header. If it is 1470 * tunneled, it includes the size of outer IP header. 1471 */ 1472 static size_t 1473 ipsec_sp_hdrsiz(const struct secpolicy *sp, const struct mbuf *m) 1474 { 1475 struct ipsecrequest *isr; 1476 size_t siz; 1477 1478 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DATA)) { 1479 printf("%s: using SP\n", __func__); 1480 kdebug_secpolicy(sp); 1481 } 1482 1483 switch (sp->policy) { 1484 case IPSEC_POLICY_DISCARD: 1485 case IPSEC_POLICY_BYPASS: 1486 case IPSEC_POLICY_NONE: 1487 return 0; 1488 } 1489 1490 KASSERTMSG(sp->policy == IPSEC_POLICY_IPSEC, 1491 "invalid policy %u", sp->policy); 1492 1493 siz = 0; 1494 for (isr = sp->req; isr != NULL; isr = isr->next) { 1495 size_t clen = 0; 1496 struct secasvar *sav; 1497 1498 switch (isr->saidx.proto) { 1499 case IPPROTO_ESP: 1500 sav = ipsec_lookup_sa(isr, m); 1501 if (sav != NULL) { 1502 clen = esp_hdrsiz(sav); 1503 KEY_SA_UNREF(&sav); 1504 } else 1505 clen = esp_hdrsiz(NULL); 1506 break; 1507 case IPPROTO_AH: 1508 sav = ipsec_lookup_sa(isr, m); 1509 if (sav != NULL) { 1510 clen = ah_hdrsiz(sav); 1511 KEY_SA_UNREF(&sav); 1512 } else 1513 clen = ah_hdrsiz(NULL); 1514 break; 1515 case IPPROTO_IPCOMP: 1516 clen = sizeof(struct ipcomp); 1517 break; 1518 } 1519 1520 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) { 1521 switch (isr->saidx.dst.sa.sa_family) { 1522 case AF_INET: 1523 clen += sizeof(struct ip); 1524 break; 1525 #ifdef INET6 1526 case AF_INET6: 1527 clen += sizeof(struct ip6_hdr); 1528 break; 1529 #endif 1530 default: 1531 IPSECLOG(LOG_ERR, "unknown AF %d in " 1532 "IPsec tunnel SA\n", 1533 ((const struct sockaddr *)&isr->saidx.dst) 1534 ->sa_family); 1535 break; 1536 } 1537 } 1538 siz += clen; 1539 } 1540 1541 return siz; 1542 } 1543 1544 size_t 1545 ipsec_hdrsiz(struct mbuf *m, u_int dir, struct inpcb *inp) 1546 { 1547 struct secpolicy *sp; 1548 int error; 1549 size_t size; 1550 1551 KASSERT(m != NULL); 1552 KASSERTMSG(inp == NULL || inp->inp_socket != NULL, 1553 "socket w/o inpcb"); 1554 1555 if (inp == NULL) 1556 sp = ipsec_getpolicybyaddr(m, dir, IP_FORWARDING, &error); 1557 else 1558 sp = ipsec_getpolicybysock(m, dir, inp, &error); 1559 1560 if (sp != NULL) { 1561 size = ipsec_sp_hdrsiz(sp, m); 1562 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DATA, "size:%zu.\n", size); 1563 KEY_SP_UNREF(&sp); 1564 } else { 1565 size = 0; 1566 } 1567 1568 return size; 1569 } 1570 1571 /* 1572 * Check the variable replay window. 1573 * ipsec_chkreplay() performs replay check before ICV verification. 1574 * ipsec_updatereplay() updates replay bitmap. This must be called after 1575 * ICV verification (it also performs replay check, which is usually done 1576 * beforehand). 1577 * 0 (zero) is returned if packet disallowed, 1 if packet permitted. 1578 * 1579 * based on RFC 2401. 1580 */ 1581 int 1582 ipsec_chkreplay(u_int32_t seq, const struct secasvar *sav) 1583 { 1584 const struct secreplay *replay; 1585 u_int32_t diff; 1586 int fr; 1587 u_int32_t wsizeb; /* constant: bits of window size */ 1588 int frlast; /* constant: last frame */ 1589 1590 KASSERT(sav != NULL); 1591 KASSERT(sav->replay != NULL); 1592 1593 replay = sav->replay; 1594 1595 if (replay->wsize == 0) 1596 return 1; /* no need to check replay. */ 1597 1598 /* constant */ 1599 frlast = replay->wsize - 1; 1600 wsizeb = replay->wsize << 3; 1601 1602 /* sequence number of 0 is invalid */ 1603 if (seq == 0) 1604 return 0; 1605 1606 /* first time is always okay */ 1607 if (replay->count == 0) 1608 return 1; 1609 1610 if (seq > replay->lastseq) { 1611 /* larger sequences are okay */ 1612 return 1; 1613 } else { 1614 /* seq is equal or less than lastseq. */ 1615 diff = replay->lastseq - seq; 1616 1617 /* over range to check, i.e. too old or wrapped */ 1618 if (diff >= wsizeb) 1619 return 0; 1620 1621 fr = frlast - diff / 8; 1622 1623 /* this packet already seen ? */ 1624 if ((replay->bitmap)[fr] & (1 << (diff % 8))) 1625 return 0; 1626 1627 /* out of order but good */ 1628 return 1; 1629 } 1630 } 1631 1632 /* 1633 * check replay counter whether to update or not. 1634 * OUT: 0: OK 1635 * 1: NG 1636 */ 1637 int 1638 ipsec_updatereplay(u_int32_t seq, const struct secasvar *sav) 1639 { 1640 struct secreplay *replay; 1641 u_int32_t diff; 1642 int fr; 1643 u_int32_t wsizeb; /* constant: bits of window size */ 1644 int frlast; /* constant: last frame */ 1645 1646 KASSERT(sav != NULL); 1647 KASSERT(sav->replay != NULL); 1648 1649 replay = sav->replay; 1650 1651 if (replay->wsize == 0) 1652 goto ok; /* no need to check replay. */ 1653 1654 /* constant */ 1655 frlast = replay->wsize - 1; 1656 wsizeb = replay->wsize << 3; 1657 1658 /* sequence number of 0 is invalid */ 1659 if (seq == 0) 1660 return 1; 1661 1662 /* first time */ 1663 if (replay->count == 0) { 1664 replay->lastseq = seq; 1665 memset(replay->bitmap, 0, replay->wsize); 1666 (replay->bitmap)[frlast] = 1; 1667 goto ok; 1668 } 1669 1670 if (seq > replay->lastseq) { 1671 /* seq is larger than lastseq. */ 1672 diff = seq - replay->lastseq; 1673 1674 /* new larger sequence number */ 1675 if (diff < wsizeb) { 1676 /* In window */ 1677 /* set bit for this packet */ 1678 vshiftl(replay->bitmap, diff, replay->wsize); 1679 (replay->bitmap)[frlast] |= 1; 1680 } else { 1681 /* this packet has a "way larger" */ 1682 memset(replay->bitmap, 0, replay->wsize); 1683 (replay->bitmap)[frlast] = 1; 1684 } 1685 replay->lastseq = seq; 1686 1687 /* larger is good */ 1688 } else { 1689 /* seq is equal or less than lastseq. */ 1690 diff = replay->lastseq - seq; 1691 1692 /* over range to check, i.e. too old or wrapped */ 1693 if (diff >= wsizeb) 1694 return 1; 1695 1696 fr = frlast - diff / 8; 1697 1698 /* this packet already seen ? */ 1699 if ((replay->bitmap)[fr] & (1 << (diff % 8))) 1700 return 1; 1701 1702 /* mark as seen */ 1703 (replay->bitmap)[fr] |= (1 << (diff % 8)); 1704 1705 /* out of order but good */ 1706 } 1707 1708 ok: 1709 if (replay->count == ~0) { 1710 char buf[IPSEC_LOGSASTRLEN]; 1711 1712 /* set overflow flag */ 1713 replay->overflow++; 1714 1715 /* don't increment, no more packets accepted */ 1716 if ((sav->flags & SADB_X_EXT_CYCSEQ) == 0) 1717 return 1; 1718 1719 IPSECLOG(LOG_WARNING, "replay counter made %d cycle. %s\n", 1720 replay->overflow, ipsec_logsastr(sav, buf, sizeof(buf))); 1721 } 1722 1723 replay->count++; 1724 1725 return 0; 1726 } 1727 1728 /* 1729 * shift variable length buffer to left. 1730 * IN: bitmap: pointer to the buffer 1731 * nbit: the number of to shift. 1732 * wsize: buffer size (bytes). 1733 */ 1734 static void 1735 vshiftl(unsigned char *bitmap, int nbit, int wsize) 1736 { 1737 int s, j, i; 1738 unsigned char over; 1739 1740 for (j = 0; j < nbit; j += 8) { 1741 s = (nbit - j < 8) ? (nbit - j): 8; 1742 bitmap[0] <<= s; 1743 for (i = 1; i < wsize; i++) { 1744 over = (bitmap[i] >> (8 - s)); 1745 bitmap[i] <<= s; 1746 bitmap[i-1] |= over; 1747 } 1748 } 1749 1750 return; 1751 } 1752 1753 /* Return a printable string for the address. */ 1754 const char * 1755 ipsec_address(const union sockaddr_union *sa, char *buf, size_t size) 1756 { 1757 switch (sa->sa.sa_family) { 1758 case AF_INET: 1759 in_print(buf, size, &sa->sin.sin_addr); 1760 return buf; 1761 #if INET6 1762 case AF_INET6: 1763 in6_print(buf, size, &sa->sin6.sin6_addr); 1764 return buf; 1765 #endif 1766 default: 1767 return "(unknown address family)"; 1768 } 1769 } 1770 1771 const char * 1772 ipsec_logsastr(const struct secasvar *sav, char *buf, size_t size) 1773 { 1774 const struct secasindex *saidx = &sav->sah->saidx; 1775 char sbuf[IPSEC_ADDRSTRLEN], dbuf[IPSEC_ADDRSTRLEN]; 1776 1777 KASSERTMSG(saidx->src.sa.sa_family == saidx->dst.sa.sa_family, 1778 "af family mismatch, src %u, dst %u", 1779 saidx->src.sa.sa_family, saidx->dst.sa.sa_family); 1780 1781 snprintf(buf, size, "SA(SPI=%u src=%s dst=%s)", 1782 (u_int32_t)ntohl(sav->spi), 1783 ipsec_address(&saidx->src, sbuf, sizeof(sbuf)), 1784 ipsec_address(&saidx->dst, dbuf, sizeof(dbuf))); 1785 1786 return buf; 1787 } 1788 1789 #ifdef INET6 1790 struct secpolicy * 1791 ipsec6_check_policy(struct mbuf *m, struct inpcb *inp, int flags, 1792 int *needipsecp, int *errorp) 1793 { 1794 struct secpolicy *sp = NULL; 1795 int error = 0; 1796 int needipsec = 0; 1797 1798 if (ipsec_outdone(m)) { 1799 goto skippolicycheck; 1800 } 1801 if (inp && ipsec_pcb_skip_ipsec(inp->inp_sp, IPSEC_DIR_OUTBOUND)) { 1802 goto skippolicycheck; 1803 } 1804 sp = ipsec_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags, &error, inp); 1805 1806 /* 1807 * There are four return cases: 1808 * sp != NULL apply IPsec policy 1809 * sp == NULL, error == 0 no IPsec handling needed 1810 * sp == NULL, error == -EINVAL discard packet w/o error 1811 * sp == NULL, error != 0 discard packet, report error 1812 */ 1813 if (sp == NULL) { 1814 needipsec = 0; 1815 } else { 1816 needipsec = 1; 1817 } 1818 1819 skippolicycheck: 1820 *errorp = error; 1821 *needipsecp = needipsec; 1822 return sp; 1823 } 1824 1825 /* 1826 * calculate UDP checksum for UDP encapsulated ESP for IPv6. 1827 * 1828 * RFC2460(Internet Protocol, Version 6 Specification) says: 1829 * 1830 * IPv6 receivers MUST discard UDP packets with a zero checksum. 1831 * 1832 * There is more relaxed specification RFC6935(IPv6 and UDP Checksums for 1833 * Tunneled Packets). The document allows zero checksum. It's too 1834 * late to publish, there are a lot of interoperability problems... 1835 */ 1836 void 1837 ipsec6_udp_cksum(struct mbuf *m) 1838 { 1839 struct ip6_hdr *ip6; 1840 uint16_t plen, uh_sum; 1841 int off; 1842 1843 /* must called after m_pullup() */ 1844 KASSERT(m->m_len >= sizeof(struct ip6_hdr)); 1845 1846 ip6 = mtod(m, struct ip6_hdr *); 1847 KASSERT(ip6->ip6_nxt == IPPROTO_UDP); 1848 1849 /* ip6->ip6_plen can not be updated before ip6_output() */ 1850 plen = m->m_pkthdr.len - sizeof(*ip6); 1851 KASSERT(plen >= sizeof(struct udphdr)); 1852 1853 uh_sum = in6_cksum(m, IPPROTO_UDP, sizeof(*ip6), plen); 1854 if (uh_sum == 0) 1855 uh_sum = 0xffff; 1856 1857 off = sizeof(*ip6) + offsetof(struct udphdr, uh_sum); 1858 m_copyback(m, off, sizeof(uh_sum), (void *)&uh_sum); 1859 } 1860 #endif /* INET6 */ 1861 1862 /* 1863 * ----------------------------------------------------------------------------- 1864 */ 1865 1866 /* XXX this stuff doesn't belong here... */ 1867 1868 static struct xformsw *xforms = NULL; 1869 1870 /* 1871 * Register a transform; typically at system startup. 1872 */ 1873 void 1874 xform_register(struct xformsw *xsp) 1875 { 1876 xsp->xf_next = xforms; 1877 xforms = xsp; 1878 } 1879 1880 /* 1881 * Initialize transform support in an sav. 1882 */ 1883 int 1884 xform_init(struct secasvar *sav, int xftype) 1885 { 1886 struct xformsw *xsp; 1887 1888 if (sav->tdb_xform != NULL) /* previously initialized */ 1889 return 0; 1890 for (xsp = xforms; xsp; xsp = xsp->xf_next) 1891 if (xsp->xf_type == xftype) 1892 return (*xsp->xf_init)(sav, xsp); 1893 1894 IPSECLOG(LOG_DEBUG, "no match for xform type %d\n", xftype); 1895 return EINVAL; 1896 } 1897 1898 /* 1899 * XXXJRT This should be done as a protosw init call. 1900 */ 1901 void 1902 ipsec_attach(void) 1903 { 1904 1905 ipsec_output_init(); 1906 1907 ipsecstat_percpu = percpu_alloc(sizeof(uint64_t) * IPSEC_NSTATS); 1908 1909 sysctl_net_inet_ipsec_setup(NULL); 1910 #ifdef INET6 1911 sysctl_net_inet6_ipsec6_setup(NULL); 1912 #endif 1913 1914 ah_attach(); 1915 esp_attach(); 1916 ipcomp_attach(); 1917 ipe4_attach(); 1918 #ifdef TCP_SIGNATURE 1919 tcpsignature_attach(); 1920 #endif 1921 } 1922
Indexes created Sat Sep 20 22:09:52 GMT 2025