ipsec.c revision 1.113
1 /* $NetBSD: ipsec.c,v 1.113 2017/08/02 01:28:03 ozaki-r Exp $ */ 2 /* $FreeBSD: /usr/local/www/cvsroot/FreeBSD/src/sys/netipsec/ipsec.c,v 1.2.2.2 2003/07/01 01:38:13 sam Exp $ */ 3 /* $KAME: ipsec.c,v 1.103 2001/05/24 07:14:18 sakane Exp $ */ 4 5 /* 6 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. Neither the name of the project nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #include <sys/cdefs.h> 35 __KERNEL_RCSID(0, "$NetBSD: ipsec.c,v 1.113 2017/08/02 01:28:03 ozaki-r Exp $"); 36 37 /* 38 * IPsec controller part. 39 */ 40 41 #if defined(_KERNEL_OPT) 42 #include "opt_inet.h" 43 #include "opt_ipsec.h" 44 #endif 45 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 #include <sys/mbuf.h> 49 #include <sys/domain.h> 50 #include <sys/protosw.h> 51 #include <sys/socket.h> 52 #include <sys/socketvar.h> 53 #include <sys/errno.h> 54 #include <sys/time.h> 55 #include <sys/kernel.h> 56 #include <sys/syslog.h> 57 #include <sys/sysctl.h> 58 #include <sys/proc.h> 59 #include <sys/kauth.h> 60 #include <sys/cpu.h> 61 #include <sys/kmem.h> 62 #include <sys/pserialize.h> 63 64 #include <net/if.h> 65 #include <net/route.h> 66 67 #include <netinet/in.h> 68 #include <netinet/in_systm.h> 69 #include <netinet/ip.h> 70 #include <netinet/ip_var.h> 71 #include <netinet/in_var.h> 72 #include <netinet/udp.h> 73 #include <netinet/udp_var.h> 74 #include <netinet/tcp.h> 75 #include <netinet/udp.h> 76 #include <netinet/ip_icmp.h> 77 #include <netinet/ip_private.h> 78 79 #include <netinet/ip6.h> 80 #ifdef INET6 81 #include <netinet6/ip6_var.h> 82 #endif 83 #include <netinet/in_pcb.h> 84 #ifdef INET6 85 #include <netinet6/in6_pcb.h> 86 #include <netinet/icmp6.h> 87 #endif 88 89 #include <netipsec/ipsec.h> 90 #include <netipsec/ipsec_var.h> 91 #include <netipsec/ipsec_private.h> 92 #ifdef INET6 93 #include <netipsec/ipsec6.h> 94 #endif 95 #include <netipsec/ah_var.h> 96 #include <netipsec/esp_var.h> 97 #include <netipsec/ipcomp.h> /*XXX*/ 98 #include <netipsec/ipcomp_var.h> 99 100 #include <netipsec/key.h> 101 #include <netipsec/keydb.h> 102 #include <netipsec/key_debug.h> 103 104 #include <netipsec/xform.h> 105 106 #include <net/net_osdep.h> 107 108 int ipsec_used = 0; 109 int ipsec_enabled = 1; 110 111 #ifdef IPSEC_DEBUG 112 int ipsec_debug = 1; 113 114 /* 115 * When set to 1, IPsec will send packets with the same sequence number. 116 * This allows to verify if the other side has proper replay attacks detection. 117 */ 118 int ipsec_replay = 0; 119 120 /* 121 * When set 1, IPsec will send packets with corrupted HMAC. 122 * This allows to verify if the other side properly detects modified packets. 123 */ 124 int ipsec_integrity = 0; 125 #else 126 int ipsec_debug = 0; 127 #endif 128 129 percpu_t *ipsecstat_percpu; 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 int ip4_esp_randpad = -1; 139 140 u_int ipsec_spdgen = 1; /* SPD generation # */ 141 142 static struct secpolicy *ipsec_checkpcbcache (struct mbuf *, 143 struct inpcbpolicy *, int); 144 static int ipsec_fillpcbcache (struct inpcbpolicy *, struct mbuf *, 145 struct secpolicy *, int); 146 static int ipsec_invalpcbcache (struct inpcbpolicy *, int); 147 148 /* 149 * Crypto support requirements: 150 * 151 * 1 require hardware support 152 * -1 require software support 153 * 0 take anything 154 */ 155 int crypto_support = 0; 156 157 static struct secpolicy *ipsec_getpolicybysock(struct mbuf *, u_int, 158 struct inpcb_hdr *, int *); 159 160 #ifdef __FreeBSD__ 161 /* net.inet.ipsec */ 162 SYSCTL_INT(_net_inet_ipsec, IPSECCTL_ESP_RANDPAD, 163 esp_randpad, CTLFLAG_RW, &ip4_esp_randpad, 0, ""); 164 SYSCTL_INT(_net_inet_ipsec, OID_AUTO, 165 crypto_support, CTLFLAG_RW, &crypto_support,0, ""); 166 SYSCTL_INT(_net_inet_ipsec, OID_AUTO, test_replay, CTLFLAG_RW, &ipsec_replay, 0, 167 "Emulate replay attack"); 168 SYSCTL_INT(_net_inet_ipsec, OID_AUTO, test_integrity, CTLFLAG_RW, 169 &ipsec_integrity, 0, "Emulate man-in-the-middle attack"); 170 #endif /* __FreeBSD__ */ 171 172 #ifdef INET6 173 int ip6_esp_trans_deflev = IPSEC_LEVEL_USE; 174 int ip6_esp_net_deflev = IPSEC_LEVEL_USE; 175 int ip6_ah_trans_deflev = IPSEC_LEVEL_USE; 176 int ip6_ah_net_deflev = IPSEC_LEVEL_USE; 177 struct secpolicy ip6_def_policy; 178 int ip6_ipsec_ecn = 0; /* ECN ignore(-1)/forbidden(0)/allowed(1) */ 179 int ip6_esp_randpad = -1; 180 181 182 #ifdef __FreeBSD__ 183 /* net.inet6.ipsec6 */ 184 SYSCTL_INT(_net_inet6_ipsec6, IPSECCTL_ESP_RANDPAD, 185 esp_randpad, CTLFLAG_RW, &ip6_esp_randpad, 0, ""); 186 #endif /* __FreeBSD__ */ 187 #endif /* INET6 */ 188 189 static int ipsec4_setspidx_inpcb (struct mbuf *, struct inpcb *); 190 #ifdef INET6 191 static int ipsec6_setspidx_in6pcb (struct mbuf *, struct in6pcb *); 192 #endif 193 static int ipsec_setspidx (struct mbuf *, struct secpolicyindex *, int); 194 static void ipsec4_get_ulp (struct mbuf *m, struct secpolicyindex *, int); 195 static int ipsec4_setspidx_ipaddr (struct mbuf *, struct secpolicyindex *); 196 #ifdef INET6 197 static void ipsec6_get_ulp (struct mbuf *m, struct secpolicyindex *, int); 198 static int ipsec6_setspidx_ipaddr (struct mbuf *, struct secpolicyindex *); 199 #endif 200 static void ipsec_delpcbpolicy (struct inpcbpolicy *); 201 static struct secpolicy *ipsec_deepcopy_policy (const struct secpolicy *); 202 static int ipsec_set_policy (struct secpolicy **, int, const void *, size_t, 203 kauth_cred_t); 204 static int ipsec_get_policy (struct secpolicy *, struct mbuf **); 205 static void ipsec_destroy_policy(struct secpolicy *); 206 static void vshiftl (unsigned char *, int, int); 207 static size_t ipsec_hdrsiz (const struct secpolicy *); 208 209 /* 210 * Try to validate and use cached policy on a PCB. 211 */ 212 static struct secpolicy * 213 ipsec_checkpcbcache(struct mbuf *m, struct inpcbpolicy *pcbsp, int dir) 214 { 215 struct secpolicyindex spidx; 216 struct secpolicy *sp = NULL; 217 int s; 218 219 KASSERT(IPSEC_DIR_IS_VALID(dir)); 220 KASSERT(pcbsp != NULL); 221 KASSERT(dir < __arraycount(pcbsp->sp_cache)); 222 KASSERT(inph_locked(pcbsp->sp_inph)); 223 224 /* 225 * Checking the generation and sp->state and taking a reference to an SP 226 * must be in a critical section of pserialize. See key_unlink_sp. 227 */ 228 s = pserialize_read_enter(); 229 /* SPD table change invalidate all the caches. */ 230 if (ipsec_spdgen != pcbsp->sp_cache[dir].cachegen) { 231 ipsec_invalpcbcache(pcbsp, dir); 232 goto out; 233 } 234 sp = pcbsp->sp_cache[dir].cachesp; 235 if (sp == NULL) 236 goto out; 237 if (sp->state != IPSEC_SPSTATE_ALIVE) { 238 sp = NULL; 239 ipsec_invalpcbcache(pcbsp, dir); 240 goto out; 241 } 242 if ((pcbsp->sp_cacheflags & IPSEC_PCBSP_CONNECTED) == 0) { 243 /* NB: assume ipsec_setspidx never sleep */ 244 if (ipsec_setspidx(m, &spidx, 1) != 0) { 245 sp = NULL; 246 goto out; 247 } 248 249 /* 250 * We have to make an exact match here since the cached rule 251 * might have lower priority than a rule that would otherwise 252 * have matched the packet. 253 */ 254 if (memcmp(&pcbsp->sp_cache[dir].cacheidx, &spidx, 255 sizeof(spidx))) { 256 sp = NULL; 257 goto out; 258 } 259 } else { 260 /* 261 * The pcb is connected, and the L4 code is sure that: 262 * - outgoing side uses inp_[lf]addr 263 * - incoming side looks up policy after inpcb lookup 264 * and address pair is know to be stable. We do not need 265 * to generate spidx again, nor check the address match again. 266 * 267 * For IPv4/v6 SOCK_STREAM sockets, this assumptions holds 268 * and there are calls to ipsec_pcbconn() from in_pcbconnect(). 269 */ 270 } 271 272 sp->lastused = time_second; 273 KEY_SP_REF(sp); 274 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_STAMP, 275 "DP cause refcnt++:%d SP:%p\n", 276 key_sp_refcnt(sp), pcbsp->sp_cache[dir].cachesp); 277 out: 278 pserialize_read_exit(s); 279 return sp; 280 } 281 282 static int 283 ipsec_fillpcbcache(struct inpcbpolicy *pcbsp, struct mbuf *m, 284 struct secpolicy *sp, int dir) 285 { 286 287 KASSERT(IPSEC_DIR_IS_INOROUT(dir)); 288 KASSERT(dir < __arraycount(pcbsp->sp_cache)); 289 KASSERT(inph_locked(pcbsp->sp_inph)); 290 291 pcbsp->sp_cache[dir].cachesp = NULL; 292 pcbsp->sp_cache[dir].cachehint = IPSEC_PCBHINT_UNKNOWN; 293 if (ipsec_setspidx(m, &pcbsp->sp_cache[dir].cacheidx, 1) != 0) { 294 return EINVAL; 295 } 296 pcbsp->sp_cache[dir].cachesp = sp; 297 if (pcbsp->sp_cache[dir].cachesp) { 298 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_STAMP, 299 "DP cause refcnt++:%d SP:%p\n", 300 key_sp_refcnt(pcbsp->sp_cache[dir].cachesp), 301 pcbsp->sp_cache[dir].cachesp); 302 303 /* 304 * If the PCB is connected, we can remember a hint to 305 * possibly short-circuit IPsec processing in other places. 306 */ 307 if (pcbsp->sp_cacheflags & IPSEC_PCBSP_CONNECTED) { 308 switch (pcbsp->sp_cache[dir].cachesp->policy) { 309 case IPSEC_POLICY_NONE: 310 case IPSEC_POLICY_BYPASS: 311 pcbsp->sp_cache[dir].cachehint = 312 IPSEC_PCBHINT_NO; 313 break; 314 default: 315 pcbsp->sp_cache[dir].cachehint = 316 IPSEC_PCBHINT_YES; 317 } 318 } 319 } 320 pcbsp->sp_cache[dir].cachegen = ipsec_spdgen; 321 322 return 0; 323 } 324 325 static int 326 ipsec_invalpcbcache(struct inpcbpolicy *pcbsp, int dir) 327 { 328 int i; 329 330 KASSERT(inph_locked(pcbsp->sp_inph)); 331 332 for (i = IPSEC_DIR_INBOUND; i <= IPSEC_DIR_OUTBOUND; i++) { 333 if (dir != IPSEC_DIR_ANY && i != dir) 334 continue; 335 pcbsp->sp_cache[i].cachesp = NULL; 336 pcbsp->sp_cache[i].cachehint = IPSEC_PCBHINT_UNKNOWN; 337 pcbsp->sp_cache[i].cachegen = 0; 338 memset(&pcbsp->sp_cache[i].cacheidx, 0, 339 sizeof(pcbsp->sp_cache[i].cacheidx)); 340 } 341 return 0; 342 } 343 344 void 345 ipsec_pcbconn(struct inpcbpolicy *pcbsp) 346 { 347 348 KASSERT(inph_locked(pcbsp->sp_inph)); 349 350 pcbsp->sp_cacheflags |= IPSEC_PCBSP_CONNECTED; 351 ipsec_invalpcbcache(pcbsp, IPSEC_DIR_ANY); 352 } 353 354 void 355 ipsec_pcbdisconn(struct inpcbpolicy *pcbsp) 356 { 357 358 KASSERT(inph_locked(pcbsp->sp_inph)); 359 360 pcbsp->sp_cacheflags &= ~IPSEC_PCBSP_CONNECTED; 361 ipsec_invalpcbcache(pcbsp, IPSEC_DIR_ANY); 362 } 363 364 void 365 ipsec_invalpcbcacheall(void) 366 { 367 368 if (ipsec_spdgen == UINT_MAX) 369 ipsec_spdgen = 1; 370 else 371 ipsec_spdgen++; 372 } 373 374 /* 375 * Return a held reference to the default SP. 376 */ 377 static struct secpolicy * 378 key_get_default_sp(int af, const char *where, int tag) 379 { 380 struct secpolicy *sp; 381 382 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_STAMP, "DP from %s:%u\n", where, tag); 383 384 switch(af) { 385 case AF_INET: 386 sp = &ip4_def_policy; 387 break; 388 #ifdef INET6 389 case AF_INET6: 390 sp = &ip6_def_policy; 391 break; 392 #endif 393 default: 394 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_STAMP, 395 "unexpected protocol family %u\n", af); 396 return NULL; 397 } 398 399 if (sp->policy != IPSEC_POLICY_DISCARD && 400 sp->policy != IPSEC_POLICY_NONE) { 401 IPSECLOG(LOG_INFO, "fixed system default policy: %d->%d\n", 402 sp->policy, IPSEC_POLICY_NONE); 403 sp->policy = IPSEC_POLICY_NONE; 404 } 405 KEY_SP_REF(sp); 406 407 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_STAMP, "DP returns SP:%p (%u)\n", 408 sp, key_sp_refcnt(sp)); 409 return sp; 410 } 411 #define KEY_GET_DEFAULT_SP(af) \ 412 key_get_default_sp((af), __func__, __LINE__) 413 414 /* 415 * For OUTBOUND packet having a socket. Searching SPD for packet, 416 * and return a pointer to SP. 417 * OUT: NULL: no apropreate SP found, the following value is set to error. 418 * 0 : bypass 419 * EACCES : discard packet. 420 * ENOENT : ipsec_acquire() in progress, maybe. 421 * others : error occurred. 422 * others: a pointer to SP 423 * 424 * NOTE: IPv6 mapped address concern is implemented here. 425 */ 426 static struct secpolicy * 427 ipsec_getpolicybysock(struct mbuf *m, u_int dir, struct inpcb_hdr *inph, 428 int *error) 429 { 430 struct inpcbpolicy *pcbsp = NULL; 431 struct secpolicy *currsp = NULL; /* policy on socket */ 432 struct secpolicy *sp; 433 int af; 434 435 KASSERT(m != NULL); 436 KASSERT(inph != NULL); 437 KASSERT(error != NULL); 438 KASSERTMSG(IPSEC_DIR_IS_INOROUT(dir), "invalid direction %u", dir); 439 440 KASSERT(inph->inph_socket != NULL); 441 KASSERT(inph_locked(inph)); 442 443 /* XXX FIXME inpcb/in6pcb vs socket*/ 444 af = inph->inph_af; 445 KASSERTMSG(af == AF_INET || af == AF_INET6, 446 "unexpected protocol family %u", af); 447 448 KASSERT(inph->inph_sp != NULL); 449 /* If we have a cached entry, and if it is still valid, use it. */ 450 IPSEC_STATINC(IPSEC_STAT_SPDCACHELOOKUP); 451 currsp = ipsec_checkpcbcache(m, inph->inph_sp, dir); 452 if (currsp) { 453 *error = 0; 454 return currsp; 455 } 456 IPSEC_STATINC(IPSEC_STAT_SPDCACHEMISS); 457 458 switch (af) { 459 case AF_INET: { 460 struct inpcb *in4p = (struct inpcb *)inph; 461 /* set spidx in pcb */ 462 *error = ipsec4_setspidx_inpcb(m, in4p); 463 pcbsp = in4p->inp_sp; 464 break; 465 } 466 467 #if defined(INET6) 468 case AF_INET6: { 469 struct in6pcb *in6p = (struct in6pcb *)inph; 470 /* set spidx in pcb */ 471 *error = ipsec6_setspidx_in6pcb(m, in6p); 472 pcbsp = in6p->in6p_sp; 473 break; 474 } 475 #endif 476 default: 477 *error = EPFNOSUPPORT; 478 break; 479 } 480 if (*error) 481 return NULL; 482 483 KASSERT(pcbsp != NULL); 484 switch (dir) { 485 case IPSEC_DIR_INBOUND: 486 currsp = pcbsp->sp_in; 487 break; 488 case IPSEC_DIR_OUTBOUND: 489 currsp = pcbsp->sp_out; 490 break; 491 } 492 KASSERT(currsp != NULL); 493 494 if (pcbsp->priv) { /* when privilieged socket */ 495 switch (currsp->policy) { 496 case IPSEC_POLICY_BYPASS: 497 case IPSEC_POLICY_IPSEC: 498 KEY_SP_REF(currsp); 499 sp = currsp; 500 break; 501 502 case IPSEC_POLICY_ENTRUST: 503 /* look for a policy in SPD */ 504 sp = KEY_LOOKUP_SP_BYSPIDX(&currsp->spidx, dir); 505 if (sp == NULL) /* no SP found */ 506 sp = KEY_GET_DEFAULT_SP(af); 507 break; 508 509 default: 510 IPSECLOG(LOG_ERR, "Invalid policy for PCB %d\n", 511 currsp->policy); 512 *error = EINVAL; 513 return NULL; 514 } 515 } else { /* unpriv, SPD has policy */ 516 sp = KEY_LOOKUP_SP_BYSPIDX(&currsp->spidx, dir); 517 if (sp == NULL) { /* no SP found */ 518 switch (currsp->policy) { 519 case IPSEC_POLICY_BYPASS: 520 IPSECLOG(LOG_ERR, "Illegal policy for " 521 "non-priviliged defined %d\n", 522 currsp->policy); 523 *error = EINVAL; 524 return NULL; 525 526 case IPSEC_POLICY_ENTRUST: 527 sp = KEY_GET_DEFAULT_SP(af); 528 break; 529 530 case IPSEC_POLICY_IPSEC: 531 KEY_SP_REF(currsp); 532 sp = currsp; 533 break; 534 535 default: 536 IPSECLOG(LOG_ERR, "Invalid policy for " 537 "PCB %d\n", currsp->policy); 538 *error = EINVAL; 539 return NULL; 540 } 541 } 542 } 543 KASSERTMSG(sp != NULL, "null SP (priv %u policy %u", pcbsp->priv, 544 currsp->policy); 545 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_STAMP, 546 "DP (priv %u policy %u) allocates SP:%p (refcnt %u)\n", 547 pcbsp->priv, currsp->policy, sp, key_sp_refcnt(sp)); 548 ipsec_fillpcbcache(pcbsp, m, sp, dir); 549 return sp; 550 } 551 552 /* 553 * For FORWADING packet or OUTBOUND without a socket. Searching SPD for packet, 554 * and return a pointer to SP. 555 * OUT: positive: a pointer to the entry for security policy leaf matched. 556 * NULL: no apropreate SP found, the following value is set to error. 557 * 0 : bypass 558 * EACCES : discard packet. 559 * ENOENT : ipsec_acquire() in progress, maybe. 560 * others : error occurred. 561 */ 562 struct secpolicy * 563 ipsec_getpolicybyaddr(struct mbuf *m, u_int dir, int flag, int *error) 564 { 565 struct secpolicyindex spidx; 566 struct secpolicy *sp; 567 568 KASSERT(m != NULL); 569 KASSERT(error != NULL); 570 KASSERTMSG(IPSEC_DIR_IS_INOROUT(dir), "invalid direction %u", dir); 571 572 sp = NULL; 573 574 /* Make an index to look for a policy. */ 575 *error = ipsec_setspidx(m, &spidx, (flag & IP_FORWARDING) ? 0 : 1); 576 if (*error != 0) { 577 IPSECLOG(LOG_DEBUG, "setpidx failed, dir %u flag %u\n", dir, flag); 578 memset(&spidx, 0, sizeof (spidx)); 579 return NULL; 580 } 581 582 spidx.dir = dir; 583 584 if (key_havesp(dir)) { 585 sp = KEY_LOOKUP_SP_BYSPIDX(&spidx, dir); 586 } 587 588 if (sp == NULL) /* no SP found, use system default */ 589 sp = KEY_GET_DEFAULT_SP(spidx.dst.sa.sa_family); 590 KASSERT(sp != NULL); 591 return sp; 592 } 593 594 struct secpolicy * 595 ipsec4_checkpolicy(struct mbuf *m, u_int dir, u_int flag, int *error, 596 struct inpcb *inp) 597 { 598 struct secpolicy *sp; 599 600 *error = 0; 601 602 if (inp == NULL) { 603 sp = ipsec_getpolicybyaddr(m, dir, flag, error); 604 } else { 605 KASSERT(inp->inp_socket != NULL); 606 sp = ipsec_getpolicybysock(m, dir, (struct inpcb_hdr *)inp, error); 607 } 608 if (sp == NULL) { 609 KASSERTMSG(*error != 0, "getpolicy failed w/o error"); 610 IPSEC_STATINC(IPSEC_STAT_OUT_INVAL); 611 return NULL; 612 } 613 KASSERTMSG(*error == 0, "sp w/ error set to %u", *error); 614 switch (sp->policy) { 615 case IPSEC_POLICY_ENTRUST: 616 default: 617 printf("%s: invalid policy %u\n", __func__, sp->policy); 618 /* fall thru... */ 619 case IPSEC_POLICY_DISCARD: 620 IPSEC_STATINC(IPSEC_STAT_OUT_POLVIO); 621 *error = -EINVAL; /* packet is discarded by caller */ 622 break; 623 case IPSEC_POLICY_BYPASS: 624 case IPSEC_POLICY_NONE: 625 KEY_SP_UNREF(&sp); 626 sp = NULL; /* NB: force NULL result */ 627 break; 628 case IPSEC_POLICY_IPSEC: 629 KASSERT(sp->req != NULL); 630 break; 631 } 632 if (*error != 0) { 633 KEY_SP_UNREF(&sp); 634 sp = NULL; 635 IPSECLOG(LOG_DEBUG, "done, error %d\n", *error); 636 } 637 return sp; 638 } 639 640 int 641 ipsec4_output(struct mbuf *m, struct inpcb *inp, int flags, 642 u_long *mtu, bool *natt_frag, bool *done) 643 { 644 struct secpolicy *sp = NULL; 645 int error, s; 646 647 /* 648 * Check the security policy (SP) for the packet and, if required, 649 * do IPsec-related processing. There are two cases here; the first 650 * time a packet is sent through it will be untagged and handled by 651 * ipsec4_checkpolicy(). If the packet is resubmitted to ip_output 652 * (e.g. after AH, ESP, etc. processing), there will be a tag to 653 * bypass the lookup and related policy checking. 654 */ 655 if (ipsec_outdone(m)) { 656 return 0; 657 } 658 s = splsoftnet(); 659 if (inp && ipsec_pcb_skip_ipsec(inp->inp_sp, IPSEC_DIR_OUTBOUND)) { 660 splx(s); 661 return 0; 662 } 663 sp = ipsec4_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags, &error, inp); 664 665 /* 666 * There are four return cases: 667 * sp != NULL apply IPsec policy 668 * sp == NULL, error == 0 no IPsec handling needed 669 * sp == NULL, error == -EINVAL discard packet w/o error 670 * sp == NULL, error != 0 discard packet, report error 671 */ 672 if (sp == NULL) { 673 splx(s); 674 if (error) { 675 /* 676 * Hack: -EINVAL is used to signal that a packet 677 * should be silently discarded. This is typically 678 * because we asked key management for an SA and 679 * it was delayed (e.g. kicked up to IKE). 680 */ 681 if (error == -EINVAL) 682 error = 0; 683 m_freem(m); 684 *done = true; 685 return error; 686 } 687 /* No IPsec processing for this packet. */ 688 return 0; 689 } 690 691 /* 692 * Do delayed checksums now because we send before 693 * this is done in the normal processing path. 694 */ 695 if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 696 in_delayed_cksum(m); 697 m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 698 } 699 700 { 701 u_long _mtu = 0; 702 703 /* Note: callee frees mbuf */ 704 error = ipsec4_process_packet(m, sp->req, &_mtu); 705 706 if (error == 0 && _mtu != 0) { 707 /* 708 * NAT-T ESP fragmentation: do not do IPSec processing 709 * now, we will do it on each fragmented packet. 710 */ 711 *mtu = _mtu; 712 *natt_frag = true; 713 KEY_SP_UNREF(&sp); 714 splx(s); 715 return 0; 716 } 717 } 718 /* 719 * Preserve KAME behaviour: ENOENT can be returned 720 * when an SA acquire is in progress. Don't propagate 721 * this to user-level; it confuses applications. 722 * 723 * XXX this will go away when the SADB is redone. 724 */ 725 if (error == ENOENT) 726 error = 0; 727 KEY_SP_UNREF(&sp); 728 splx(s); 729 *done = true; 730 return error; 731 } 732 733 int 734 ipsec4_input(struct mbuf *m, int flags) 735 { 736 struct secpolicy *sp; 737 int error, s; 738 739 s = splsoftnet(); 740 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND, IP_FORWARDING, &error); 741 if (sp == NULL) { 742 splx(s); 743 return EINVAL; 744 } 745 746 /* 747 * Check security policy against packet attributes. 748 */ 749 error = ipsec_in_reject(sp, m); 750 KEY_SP_UNREF(&sp); 751 splx(s); 752 if (error) { 753 return error; 754 } 755 756 if (flags == 0) { 757 /* We are done. */ 758 return 0; 759 } 760 761 /* 762 * Peek at the outbound SP for this packet to determine if 763 * it is a Fast Forward candidate. 764 */ 765 s = splsoftnet(); 766 sp = ipsec4_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags, &error, NULL); 767 if (sp != NULL) { 768 m->m_flags &= ~M_CANFASTFWD; 769 KEY_SP_UNREF(&sp); 770 } 771 splx(s); 772 return 0; 773 } 774 775 int 776 ipsec4_forward(struct mbuf *m, int *destmtu) 777 { 778 /* 779 * If the packet is routed over IPsec tunnel, tell the 780 * originator the tunnel MTU. 781 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz 782 * XXX quickhack!!! 783 */ 784 struct secpolicy *sp; 785 size_t ipsechdr; 786 int error; 787 788 sp = ipsec4_getpolicybyaddr(m, 789 IPSEC_DIR_OUTBOUND, IP_FORWARDING, &error); 790 if (sp == NULL) { 791 return EINVAL; 792 } 793 794 /* Count IPsec header size. */ 795 ipsechdr = ipsec4_hdrsiz(m, IPSEC_DIR_OUTBOUND, NULL); 796 797 /* 798 * Find the correct route for outer IPv4 header, compute tunnel MTU. 799 */ 800 if (sp->req) { 801 struct route *ro; 802 struct rtentry *rt; 803 struct secasvar *sav = NULL; 804 805 error = key_checkrequest(sp->req, &sav); 806 if (error != 0) 807 return error; 808 ro = &sav->sah->sa_route; 809 rt = rtcache_validate(ro); 810 if (rt && rt->rt_ifp) { 811 *destmtu = rt->rt_rmx.rmx_mtu ? 812 rt->rt_rmx.rmx_mtu : rt->rt_ifp->if_mtu; 813 *destmtu -= ipsechdr; 814 } 815 rtcache_unref(rt, ro); 816 KEY_FREESAV(&sav); 817 } 818 KEY_SP_UNREF(&sp); 819 return 0; 820 } 821 822 #ifdef INET6 823 struct secpolicy * 824 ipsec6_checkpolicy(struct mbuf *m, u_int dir, u_int flag, int *error, 825 struct in6pcb *in6p) 826 { 827 struct secpolicy *sp; 828 829 *error = 0; 830 831 if (in6p == NULL) { 832 sp = ipsec_getpolicybyaddr(m, dir, flag, error); 833 } else { 834 KASSERT(in6p->in6p_socket != NULL); 835 sp = ipsec_getpolicybysock(m, dir, (struct inpcb_hdr *)in6p, error); 836 } 837 if (sp == NULL) { 838 KASSERTMSG(*error != 0, "getpolicy failed w/o error"); 839 IPSEC_STATINC(IPSEC_STAT_OUT_INVAL); 840 return NULL; 841 } 842 KASSERTMSG(*error == 0, "sp w/ error set to %u", *error); 843 switch (sp->policy) { 844 case IPSEC_POLICY_ENTRUST: 845 default: 846 printf("%s: invalid policy %u\n", __func__, sp->policy); 847 /* fall thru... */ 848 case IPSEC_POLICY_DISCARD: 849 IPSEC_STATINC(IPSEC_STAT_OUT_POLVIO); 850 *error = -EINVAL; /* packet is discarded by caller */ 851 break; 852 case IPSEC_POLICY_BYPASS: 853 case IPSEC_POLICY_NONE: 854 KEY_SP_UNREF(&sp); 855 sp = NULL; /* NB: force NULL result */ 856 break; 857 case IPSEC_POLICY_IPSEC: 858 KASSERT(sp->req != NULL); 859 break; 860 } 861 if (*error != 0) { 862 KEY_SP_UNREF(&sp); 863 sp = NULL; 864 IPSECLOG(LOG_DEBUG, "done, error %d\n", *error); 865 } 866 return sp; 867 } 868 #endif /* INET6 */ 869 870 static int 871 ipsec4_setspidx_inpcb(struct mbuf *m, struct inpcb *pcb) 872 { 873 int error; 874 875 KASSERT(pcb != NULL); 876 KASSERT(pcb->inp_sp != NULL); 877 KASSERT(pcb->inp_sp->sp_out != NULL); 878 KASSERT(pcb->inp_sp->sp_in != NULL); 879 880 error = ipsec_setspidx(m, &pcb->inp_sp->sp_in->spidx, 1); 881 if (error == 0) { 882 pcb->inp_sp->sp_in->spidx.dir = IPSEC_DIR_INBOUND; 883 pcb->inp_sp->sp_out->spidx = pcb->inp_sp->sp_in->spidx; 884 pcb->inp_sp->sp_out->spidx.dir = IPSEC_DIR_OUTBOUND; 885 } else { 886 memset(&pcb->inp_sp->sp_in->spidx, 0, 887 sizeof(pcb->inp_sp->sp_in->spidx)); 888 memset(&pcb->inp_sp->sp_out->spidx, 0, 889 sizeof(pcb->inp_sp->sp_in->spidx)); 890 } 891 return error; 892 } 893 894 #ifdef INET6 895 static int 896 ipsec6_setspidx_in6pcb(struct mbuf *m, struct in6pcb *pcb) 897 { 898 struct secpolicyindex *spidx; 899 int error; 900 901 KASSERT(pcb != NULL); 902 KASSERT(pcb->in6p_sp != NULL); 903 KASSERT(pcb->in6p_sp->sp_out != NULL); 904 KASSERT(pcb->in6p_sp->sp_in != NULL); 905 906 memset(&pcb->in6p_sp->sp_in->spidx, 0, sizeof(*spidx)); 907 memset(&pcb->in6p_sp->sp_out->spidx, 0, sizeof(*spidx)); 908 909 spidx = &pcb->in6p_sp->sp_in->spidx; 910 error = ipsec_setspidx(m, spidx, 1); 911 if (error) 912 goto bad; 913 spidx->dir = IPSEC_DIR_INBOUND; 914 915 spidx = &pcb->in6p_sp->sp_out->spidx; 916 error = ipsec_setspidx(m, spidx, 1); 917 if (error) 918 goto bad; 919 spidx->dir = IPSEC_DIR_OUTBOUND; 920 921 return 0; 922 923 bad: 924 memset(&pcb->in6p_sp->sp_in->spidx, 0, sizeof(*spidx)); 925 memset(&pcb->in6p_sp->sp_out->spidx, 0, sizeof(*spidx)); 926 return error; 927 } 928 #endif 929 930 /* 931 * configure security policy index (src/dst/proto/sport/dport) 932 * by looking at the content of mbuf. 933 * the caller is responsible for error recovery (like clearing up spidx). 934 */ 935 static int 936 ipsec_setspidx(struct mbuf *m, struct secpolicyindex *spidx, int needport) 937 { 938 struct ip *ip = NULL; 939 struct ip ipbuf; 940 u_int v; 941 struct mbuf *n; 942 int len; 943 int error; 944 945 KASSERT(m != NULL); 946 947 /* 948 * validate m->m_pkthdr.len. we see incorrect length if we 949 * mistakenly call this function with inconsistent mbuf chain 950 * (like 4.4BSD tcp/udp processing). XXX should we panic here? 951 */ 952 len = 0; 953 for (n = m; n; n = n->m_next) 954 len += n->m_len; 955 if (m->m_pkthdr.len != len) { 956 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 957 "total of m_len(%d) != pkthdr.len(%d), ignored.\n", 958 len, m->m_pkthdr.len); 959 return EINVAL; 960 } 961 962 if (m->m_pkthdr.len < sizeof(struct ip)) { 963 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 964 "pkthdr.len(%d) < sizeof(struct ip), ignored.\n", 965 m->m_pkthdr.len); 966 return EINVAL; 967 } 968 969 if (m->m_len >= sizeof(*ip)) 970 ip = mtod(m, struct ip *); 971 else { 972 m_copydata(m, 0, sizeof(ipbuf), &ipbuf); 973 ip = &ipbuf; 974 } 975 v = ip->ip_v; 976 switch (v) { 977 case 4: 978 error = ipsec4_setspidx_ipaddr(m, spidx); 979 if (error) 980 return error; 981 ipsec4_get_ulp(m, spidx, needport); 982 return 0; 983 #ifdef INET6 984 case 6: 985 if (m->m_pkthdr.len < sizeof(struct ip6_hdr)) { 986 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 987 "pkthdr.len(%d) < sizeof(struct ip6_hdr), " 988 "ignored.\n", m->m_pkthdr.len); 989 return EINVAL; 990 } 991 error = ipsec6_setspidx_ipaddr(m, spidx); 992 if (error) 993 return error; 994 ipsec6_get_ulp(m, spidx, needport); 995 return 0; 996 #endif 997 default: 998 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 999 "unknown IP version %u, ignored.\n", v); 1000 return EINVAL; 1001 } 1002 } 1003 1004 static void 1005 ipsec4_get_ulp(struct mbuf *m, struct secpolicyindex *spidx, int needport) 1006 { 1007 u_int8_t nxt; 1008 int off; 1009 1010 /* sanity check */ 1011 KASSERT(m != NULL); 1012 KASSERTMSG(m->m_pkthdr.len >= sizeof(struct ip), "packet too short"); 1013 1014 /* NB: ip_input() flips it into host endian XXX need more checking */ 1015 if (m->m_len >= sizeof(struct ip)) { 1016 struct ip *ip = mtod(m, struct ip *); 1017 if (ip->ip_off & htons(IP_MF | IP_OFFMASK)) 1018 goto done; 1019 off = ip->ip_hl << 2; 1020 nxt = ip->ip_p; 1021 } else { 1022 struct ip ih; 1023 1024 m_copydata(m, 0, sizeof (struct ip), &ih); 1025 if (ih.ip_off & htons(IP_MF | IP_OFFMASK)) 1026 goto done; 1027 off = ih.ip_hl << 2; 1028 nxt = ih.ip_p; 1029 } 1030 1031 while (off < m->m_pkthdr.len) { 1032 struct ip6_ext ip6e; 1033 struct tcphdr th; 1034 struct udphdr uh; 1035 struct icmp icmph; 1036 1037 switch (nxt) { 1038 case IPPROTO_TCP: 1039 spidx->ul_proto = nxt; 1040 if (!needport) 1041 goto done_proto; 1042 if (off + sizeof(struct tcphdr) > m->m_pkthdr.len) 1043 goto done; 1044 m_copydata(m, off, sizeof (th), &th); 1045 spidx->src.sin.sin_port = th.th_sport; 1046 spidx->dst.sin.sin_port = th.th_dport; 1047 return; 1048 case IPPROTO_UDP: 1049 spidx->ul_proto = nxt; 1050 if (!needport) 1051 goto done_proto; 1052 if (off + sizeof(struct udphdr) > m->m_pkthdr.len) 1053 goto done; 1054 m_copydata(m, off, sizeof (uh), &uh); 1055 spidx->src.sin.sin_port = uh.uh_sport; 1056 spidx->dst.sin.sin_port = uh.uh_dport; 1057 return; 1058 case IPPROTO_AH: 1059 if (m->m_pkthdr.len > off + sizeof(ip6e)) 1060 goto done; 1061 /* XXX sigh, this works but is totally bogus */ 1062 m_copydata(m, off, sizeof(ip6e), &ip6e); 1063 off += (ip6e.ip6e_len + 2) << 2; 1064 nxt = ip6e.ip6e_nxt; 1065 break; 1066 case IPPROTO_ICMP: 1067 spidx->ul_proto = nxt; 1068 if (off + sizeof(struct icmp) > m->m_pkthdr.len) 1069 return; 1070 m_copydata(m, off, sizeof(icmph), &icmph); 1071 ((struct sockaddr_in *)&spidx->src)->sin_port = 1072 htons((uint16_t)icmph.icmp_type); 1073 ((struct sockaddr_in *)&spidx->dst)->sin_port = 1074 htons((uint16_t)icmph.icmp_code); 1075 return; 1076 default: 1077 /* XXX intermediate headers??? */ 1078 spidx->ul_proto = nxt; 1079 goto done_proto; 1080 } 1081 } 1082 done: 1083 spidx->ul_proto = IPSEC_ULPROTO_ANY; 1084 done_proto: 1085 spidx->src.sin.sin_port = IPSEC_PORT_ANY; 1086 spidx->dst.sin.sin_port = IPSEC_PORT_ANY; 1087 } 1088 1089 /* assumes that m is sane */ 1090 static int 1091 ipsec4_setspidx_ipaddr(struct mbuf *m, struct secpolicyindex *spidx) 1092 { 1093 static const struct sockaddr_in template = { 1094 sizeof (struct sockaddr_in), 1095 AF_INET, 1096 0, { 0 }, { 0, 0, 0, 0, 0, 0, 0, 0 } 1097 }; 1098 1099 spidx->src.sin = template; 1100 spidx->dst.sin = template; 1101 1102 if (m->m_len < sizeof (struct ip)) { 1103 m_copydata(m, offsetof(struct ip, ip_src), 1104 sizeof(struct in_addr), &spidx->src.sin.sin_addr); 1105 m_copydata(m, offsetof(struct ip, ip_dst), 1106 sizeof(struct in_addr), &spidx->dst.sin.sin_addr); 1107 } else { 1108 struct ip *ip = mtod(m, struct ip *); 1109 spidx->src.sin.sin_addr = ip->ip_src; 1110 spidx->dst.sin.sin_addr = ip->ip_dst; 1111 } 1112 1113 spidx->prefs = sizeof(struct in_addr) << 3; 1114 spidx->prefd = sizeof(struct in_addr) << 3; 1115 1116 return 0; 1117 } 1118 1119 #ifdef INET6 1120 static void 1121 ipsec6_get_ulp(struct mbuf *m, struct secpolicyindex *spidx, 1122 int needport) 1123 { 1124 int off, nxt; 1125 struct tcphdr th; 1126 struct udphdr uh; 1127 struct icmp6_hdr icmph; 1128 1129 KASSERT(m != NULL); 1130 1131 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DUMP)) { 1132 printf("%s:\n", __func__); 1133 kdebug_mbuf(m); 1134 } 1135 1136 /* set default */ 1137 spidx->ul_proto = IPSEC_ULPROTO_ANY; 1138 ((struct sockaddr_in6 *)&spidx->src)->sin6_port = IPSEC_PORT_ANY; 1139 ((struct sockaddr_in6 *)&spidx->dst)->sin6_port = IPSEC_PORT_ANY; 1140 1141 nxt = -1; 1142 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt); 1143 if (off < 0 || m->m_pkthdr.len < off) 1144 return; 1145 1146 switch (nxt) { 1147 case IPPROTO_TCP: 1148 spidx->ul_proto = nxt; 1149 if (!needport) 1150 break; 1151 if (off + sizeof(struct tcphdr) > m->m_pkthdr.len) 1152 break; 1153 m_copydata(m, off, sizeof(th), &th); 1154 ((struct sockaddr_in6 *)&spidx->src)->sin6_port = th.th_sport; 1155 ((struct sockaddr_in6 *)&spidx->dst)->sin6_port = th.th_dport; 1156 break; 1157 case IPPROTO_UDP: 1158 spidx->ul_proto = nxt; 1159 if (!needport) 1160 break; 1161 if (off + sizeof(struct udphdr) > m->m_pkthdr.len) 1162 break; 1163 m_copydata(m, off, sizeof(uh), &uh); 1164 ((struct sockaddr_in6 *)&spidx->src)->sin6_port = uh.uh_sport; 1165 ((struct sockaddr_in6 *)&spidx->dst)->sin6_port = uh.uh_dport; 1166 break; 1167 case IPPROTO_ICMPV6: 1168 spidx->ul_proto = nxt; 1169 if (off + sizeof(struct icmp6_hdr) > m->m_pkthdr.len) 1170 break; 1171 m_copydata(m, off, sizeof(icmph), &icmph); 1172 ((struct sockaddr_in6 *)&spidx->src)->sin6_port = 1173 htons((uint16_t)icmph.icmp6_type); 1174 ((struct sockaddr_in6 *)&spidx->dst)->sin6_port = 1175 htons((uint16_t)icmph.icmp6_code); 1176 break; 1177 default: 1178 /* XXX intermediate headers??? */ 1179 spidx->ul_proto = nxt; 1180 break; 1181 } 1182 } 1183 1184 /* assumes that m is sane */ 1185 static int 1186 ipsec6_setspidx_ipaddr(struct mbuf *m, struct secpolicyindex *spidx) 1187 { 1188 struct ip6_hdr *ip6 = NULL; 1189 struct ip6_hdr ip6buf; 1190 struct sockaddr_in6 *sin6; 1191 1192 if (m->m_len >= sizeof(*ip6)) 1193 ip6 = mtod(m, struct ip6_hdr *); 1194 else { 1195 m_copydata(m, 0, sizeof(ip6buf), &ip6buf); 1196 ip6 = &ip6buf; 1197 } 1198 1199 sin6 = (struct sockaddr_in6 *)&spidx->src; 1200 memset(sin6, 0, sizeof(*sin6)); 1201 sin6->sin6_family = AF_INET6; 1202 sin6->sin6_len = sizeof(struct sockaddr_in6); 1203 memcpy(&sin6->sin6_addr, &ip6->ip6_src, sizeof(ip6->ip6_src)); 1204 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) { 1205 sin6->sin6_addr.s6_addr16[1] = 0; 1206 sin6->sin6_scope_id = ntohs(ip6->ip6_src.s6_addr16[1]); 1207 } 1208 spidx->prefs = sizeof(struct in6_addr) << 3; 1209 1210 sin6 = (struct sockaddr_in6 *)&spidx->dst; 1211 memset(sin6, 0, sizeof(*sin6)); 1212 sin6->sin6_family = AF_INET6; 1213 sin6->sin6_len = sizeof(struct sockaddr_in6); 1214 memcpy(&sin6->sin6_addr, &ip6->ip6_dst, sizeof(ip6->ip6_dst)); 1215 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) { 1216 sin6->sin6_addr.s6_addr16[1] = 0; 1217 sin6->sin6_scope_id = ntohs(ip6->ip6_dst.s6_addr16[1]); 1218 } 1219 spidx->prefd = sizeof(struct in6_addr) << 3; 1220 1221 return 0; 1222 } 1223 #endif 1224 1225 static void 1226 ipsec_delpcbpolicy(struct inpcbpolicy *p) 1227 { 1228 1229 kmem_intr_free(p, sizeof(*p)); 1230 } 1231 1232 /* initialize policy in PCB */ 1233 int 1234 ipsec_init_policy(struct socket *so, struct inpcbpolicy **policy) 1235 { 1236 struct inpcbpolicy *new; 1237 1238 KASSERT(so != NULL); 1239 KASSERT(policy != NULL); 1240 1241 new = kmem_intr_zalloc(sizeof(*new), KM_NOSLEEP); 1242 if (new == NULL) { 1243 IPSECLOG(LOG_DEBUG, "No more memory.\n"); 1244 return ENOBUFS; 1245 } 1246 1247 if (IPSEC_PRIVILEGED_SO(so)) 1248 new->priv = 1; 1249 else 1250 new->priv = 0; 1251 1252 /* 1253 * These SPs are dummy. Never be used because the policy 1254 * is ENTRUST. See ipsec_getpolicybysock. 1255 */ 1256 if ((new->sp_in = KEY_NEWSP()) == NULL) { 1257 ipsec_delpcbpolicy(new); 1258 return ENOBUFS; 1259 } 1260 new->sp_in->state = IPSEC_SPSTATE_ALIVE; 1261 new->sp_in->policy = IPSEC_POLICY_ENTRUST; 1262 new->sp_in->created = 0; /* Indicates dummy */ 1263 1264 if ((new->sp_out = KEY_NEWSP()) == NULL) { 1265 KEY_SP_UNREF(&new->sp_in); 1266 ipsec_delpcbpolicy(new); 1267 return ENOBUFS; 1268 } 1269 new->sp_out->state = IPSEC_SPSTATE_ALIVE; 1270 new->sp_out->policy = IPSEC_POLICY_ENTRUST; 1271 new->sp_out->created = 0; /* Indicates dummy */ 1272 1273 *policy = new; 1274 1275 return 0; 1276 } 1277 1278 /* copy old ipsec policy into new */ 1279 int 1280 ipsec_copy_policy(const struct inpcbpolicy *old, struct inpcbpolicy *new) 1281 { 1282 struct secpolicy *sp; 1283 1284 sp = ipsec_deepcopy_policy(old->sp_in); 1285 if (sp) { 1286 KEY_SP_UNREF(&new->sp_in); 1287 new->sp_in = sp; 1288 } else 1289 return ENOBUFS; 1290 1291 sp = ipsec_deepcopy_policy(old->sp_out); 1292 if (sp) { 1293 KEY_SP_UNREF(&new->sp_out); 1294 new->sp_out = sp; 1295 } else 1296 return ENOBUFS; 1297 1298 new->priv = old->priv; 1299 1300 return 0; 1301 } 1302 1303 /* deep-copy a policy in PCB */ 1304 static struct secpolicy * 1305 ipsec_deepcopy_policy(const struct secpolicy *src) 1306 { 1307 struct ipsecrequest *newchain = NULL; 1308 const struct ipsecrequest *p; 1309 struct ipsecrequest **q; 1310 struct secpolicy *dst; 1311 1312 if (src == NULL) 1313 return NULL; 1314 dst = KEY_NEWSP(); 1315 if (dst == NULL) 1316 return NULL; 1317 1318 /* 1319 * deep-copy IPsec request chain. This is required since struct 1320 * ipsecrequest is not reference counted. 1321 */ 1322 q = &newchain; 1323 for (p = src->req; p; p = p->next) { 1324 *q = kmem_zalloc(sizeof(**q), KM_SLEEP); 1325 (*q)->next = NULL; 1326 1327 (*q)->saidx.proto = p->saidx.proto; 1328 (*q)->saidx.mode = p->saidx.mode; 1329 (*q)->level = p->level; 1330 (*q)->saidx.reqid = p->saidx.reqid; 1331 1332 memcpy(&(*q)->saidx.src, &p->saidx.src, sizeof((*q)->saidx.src)); 1333 memcpy(&(*q)->saidx.dst, &p->saidx.dst, sizeof((*q)->saidx.dst)); 1334 1335 (*q)->sp = dst; 1336 1337 q = &((*q)->next); 1338 } 1339 1340 dst->req = newchain; 1341 dst->state = src->state; 1342 dst->policy = src->policy; 1343 /* do not touch the refcnt fields */ 1344 1345 return dst; 1346 } 1347 1348 static void 1349 ipsec_destroy_policy(struct secpolicy *sp) 1350 { 1351 1352 if (sp->created == 0) 1353 /* It's dummy. We can simply free it */ 1354 key_free_sp(sp); 1355 else { 1356 /* 1357 * We cannot destroy here because it can be called in 1358 * softint. So mark the SP as DEAD and let the timer 1359 * destroy it. See key_timehandler_spd. 1360 */ 1361 sp->state = IPSEC_SPSTATE_DEAD; 1362 } 1363 } 1364 1365 /* set policy and ipsec request if present. */ 1366 static int 1367 ipsec_set_policy( 1368 struct secpolicy **policy, 1369 int optname, 1370 const void *request, 1371 size_t len, 1372 kauth_cred_t cred 1373 ) 1374 { 1375 const struct sadb_x_policy *xpl; 1376 struct secpolicy *newsp = NULL, *oldsp; 1377 int error; 1378 1379 KASSERT(!cpu_softintr_p()); 1380 1381 /* sanity check. */ 1382 if (policy == NULL || *policy == NULL || request == NULL) 1383 return EINVAL; 1384 if (len < sizeof(*xpl)) 1385 return EINVAL; 1386 xpl = (const struct sadb_x_policy *)request; 1387 1388 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DUMP)) { 1389 printf("%s: passed policy\n", __func__); 1390 kdebug_sadb_x_policy((const struct sadb_ext *)xpl); 1391 } 1392 1393 /* check policy type */ 1394 /* ipsec_set_policy() accepts IPSEC, ENTRUST and BYPASS. */ 1395 if (xpl->sadb_x_policy_type == IPSEC_POLICY_DISCARD 1396 || xpl->sadb_x_policy_type == IPSEC_POLICY_NONE) 1397 return EINVAL; 1398 1399 /* check privileged socket */ 1400 if (xpl->sadb_x_policy_type == IPSEC_POLICY_BYPASS) { 1401 error = kauth_authorize_network(cred, KAUTH_NETWORK_IPSEC, 1402 KAUTH_REQ_NETWORK_IPSEC_BYPASS, NULL, NULL, NULL); 1403 if (error) 1404 return (error); 1405 } 1406 1407 /* allocation new SP entry */ 1408 if ((newsp = key_msg2sp(xpl, len, &error)) == NULL) 1409 return error; 1410 1411 key_init_sp(newsp); 1412 newsp->created = time_uptime; 1413 /* Insert the global list for SPs for sockets */ 1414 key_socksplist_add(newsp); 1415 1416 /* clear old SP and set new SP */ 1417 oldsp = *policy; 1418 *policy = newsp; 1419 ipsec_destroy_policy(oldsp); 1420 1421 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DUMP)) { 1422 printf("%s: new policy\n", __func__); 1423 kdebug_secpolicy(newsp); 1424 } 1425 1426 return 0; 1427 } 1428 1429 static int 1430 ipsec_get_policy(struct secpolicy *policy, struct mbuf **mp) 1431 { 1432 1433 /* sanity check. */ 1434 if (policy == NULL || mp == NULL) 1435 return EINVAL; 1436 1437 *mp = key_sp2msg(policy); 1438 if (!*mp) { 1439 IPSECLOG(LOG_DEBUG, "No more memory.\n"); 1440 return ENOBUFS; 1441 } 1442 1443 (*mp)->m_type = MT_DATA; 1444 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DUMP)) { 1445 printf("%s:\n", __func__); 1446 kdebug_mbuf(*mp); 1447 } 1448 1449 return 0; 1450 } 1451 1452 int 1453 ipsec4_set_policy(struct inpcb *inp, int optname, const void *request, 1454 size_t len, kauth_cred_t cred) 1455 { 1456 const struct sadb_x_policy *xpl; 1457 struct secpolicy **policy; 1458 1459 KASSERT(!cpu_softintr_p()); 1460 KASSERT(inp_locked(inp)); 1461 1462 /* sanity check. */ 1463 if (inp == NULL || request == NULL) 1464 return EINVAL; 1465 if (len < sizeof(*xpl)) 1466 return EINVAL; 1467 xpl = (const struct sadb_x_policy *)request; 1468 1469 KASSERT(inp->inp_sp != NULL); 1470 1471 /* select direction */ 1472 switch (xpl->sadb_x_policy_dir) { 1473 case IPSEC_DIR_INBOUND: 1474 policy = &inp->inp_sp->sp_in; 1475 break; 1476 case IPSEC_DIR_OUTBOUND: 1477 policy = &inp->inp_sp->sp_out; 1478 break; 1479 default: 1480 IPSECLOG(LOG_ERR, "invalid direction=%u\n", 1481 xpl->sadb_x_policy_dir); 1482 return EINVAL; 1483 } 1484 1485 return ipsec_set_policy(policy, optname, request, len, cred); 1486 } 1487 1488 int 1489 ipsec4_get_policy(struct inpcb *inp, const void *request, size_t len, 1490 struct mbuf **mp) 1491 { 1492 const struct sadb_x_policy *xpl; 1493 struct secpolicy *policy; 1494 1495 /* sanity check. */ 1496 if (inp == NULL || request == NULL || mp == NULL) 1497 return EINVAL; 1498 KASSERT(inp->inp_sp != NULL); 1499 if (len < sizeof(*xpl)) 1500 return EINVAL; 1501 xpl = (const struct sadb_x_policy *)request; 1502 1503 /* select direction */ 1504 switch (xpl->sadb_x_policy_dir) { 1505 case IPSEC_DIR_INBOUND: 1506 policy = inp->inp_sp->sp_in; 1507 break; 1508 case IPSEC_DIR_OUTBOUND: 1509 policy = inp->inp_sp->sp_out; 1510 break; 1511 default: 1512 IPSECLOG(LOG_ERR, "invalid direction=%u\n", 1513 xpl->sadb_x_policy_dir); 1514 return EINVAL; 1515 } 1516 1517 return ipsec_get_policy(policy, mp); 1518 } 1519 1520 /* delete policy in PCB */ 1521 int 1522 ipsec4_delete_pcbpolicy(struct inpcb *inp) 1523 { 1524 1525 KASSERT(inp != NULL); 1526 1527 if (inp->inp_sp == NULL) 1528 return 0; 1529 1530 if (inp->inp_sp->sp_in != NULL) 1531 ipsec_destroy_policy(inp->inp_sp->sp_in); 1532 1533 if (inp->inp_sp->sp_out != NULL) 1534 ipsec_destroy_policy(inp->inp_sp->sp_out); 1535 1536 ipsec_invalpcbcache(inp->inp_sp, IPSEC_DIR_ANY); 1537 1538 ipsec_delpcbpolicy(inp->inp_sp); 1539 inp->inp_sp = NULL; 1540 1541 return 0; 1542 } 1543 1544 #ifdef INET6 1545 int 1546 ipsec6_set_policy(struct in6pcb *in6p, int optname, const void *request, 1547 size_t len, kauth_cred_t cred) 1548 { 1549 const struct sadb_x_policy *xpl; 1550 struct secpolicy **policy; 1551 1552 KASSERT(!cpu_softintr_p()); 1553 KASSERT(in6p_locked(in6p)); 1554 1555 /* sanity check. */ 1556 if (in6p == NULL || request == NULL) 1557 return EINVAL; 1558 if (len < sizeof(*xpl)) 1559 return EINVAL; 1560 xpl = (const struct sadb_x_policy *)request; 1561 1562 /* select direction */ 1563 switch (xpl->sadb_x_policy_dir) { 1564 case IPSEC_DIR_INBOUND: 1565 policy = &in6p->in6p_sp->sp_in; 1566 break; 1567 case IPSEC_DIR_OUTBOUND: 1568 policy = &in6p->in6p_sp->sp_out; 1569 break; 1570 default: 1571 IPSECLOG(LOG_ERR, "invalid direction=%u\n", 1572 xpl->sadb_x_policy_dir); 1573 return EINVAL; 1574 } 1575 1576 return ipsec_set_policy(policy, optname, request, len, cred); 1577 } 1578 1579 int 1580 ipsec6_get_policy(struct in6pcb *in6p, const void *request, size_t len, 1581 struct mbuf **mp) 1582 { 1583 const struct sadb_x_policy *xpl; 1584 struct secpolicy *policy; 1585 1586 /* sanity check. */ 1587 if (in6p == NULL || request == NULL || mp == NULL) 1588 return EINVAL; 1589 KASSERT(in6p->in6p_sp != NULL); 1590 if (len < sizeof(*xpl)) 1591 return EINVAL; 1592 xpl = (const struct sadb_x_policy *)request; 1593 1594 /* select direction */ 1595 switch (xpl->sadb_x_policy_dir) { 1596 case IPSEC_DIR_INBOUND: 1597 policy = in6p->in6p_sp->sp_in; 1598 break; 1599 case IPSEC_DIR_OUTBOUND: 1600 policy = in6p->in6p_sp->sp_out; 1601 break; 1602 default: 1603 IPSECLOG(LOG_ERR, "invalid direction=%u\n", 1604 xpl->sadb_x_policy_dir); 1605 return EINVAL; 1606 } 1607 1608 return ipsec_get_policy(policy, mp); 1609 } 1610 1611 int 1612 ipsec6_delete_pcbpolicy(struct in6pcb *in6p) 1613 { 1614 1615 KASSERT(in6p != NULL); 1616 1617 if (in6p->in6p_sp == NULL) 1618 return 0; 1619 1620 if (in6p->in6p_sp->sp_in != NULL) 1621 ipsec_destroy_policy(in6p->in6p_sp->sp_in); 1622 1623 if (in6p->in6p_sp->sp_out != NULL) 1624 ipsec_destroy_policy(in6p->in6p_sp->sp_out); 1625 1626 ipsec_invalpcbcache(in6p->in6p_sp, IPSEC_DIR_ANY); 1627 1628 ipsec_delpcbpolicy(in6p->in6p_sp); 1629 in6p->in6p_sp = NULL; 1630 1631 return 0; 1632 } 1633 #endif 1634 1635 /* 1636 * return current level. 1637 * Either IPSEC_LEVEL_USE or IPSEC_LEVEL_REQUIRE are always returned. 1638 */ 1639 u_int 1640 ipsec_get_reqlevel(const struct ipsecrequest *isr) 1641 { 1642 u_int level = 0; 1643 u_int esp_trans_deflev, esp_net_deflev; 1644 u_int ah_trans_deflev, ah_net_deflev; 1645 1646 KASSERT(isr != NULL); 1647 KASSERT(isr->sp != NULL); 1648 KASSERTMSG( 1649 isr->sp->spidx.src.sa.sa_family == isr->sp->spidx.dst.sa.sa_family, 1650 "af family mismatch, src %u, dst %u", 1651 isr->sp->spidx.src.sa.sa_family, isr->sp->spidx.dst.sa.sa_family); 1652 1653 /* XXX note that we have ipseclog() expanded here - code sync issue */ 1654 #define IPSEC_CHECK_DEFAULT(lev) \ 1655 (((lev) != IPSEC_LEVEL_USE && (lev) != IPSEC_LEVEL_REQUIRE \ 1656 && (lev) != IPSEC_LEVEL_UNIQUE) ? \ 1657 (ipsec_debug ? log(LOG_INFO, "fixed system default level " #lev \ 1658 ":%d->%d\n", (lev), IPSEC_LEVEL_REQUIRE) : (void)0), \ 1659 (lev) = IPSEC_LEVEL_REQUIRE, (lev) \ 1660 : (lev)) 1661 1662 /* set default level */ 1663 switch (((struct sockaddr *)&isr->sp->spidx.src)->sa_family) { 1664 #ifdef INET 1665 case AF_INET: 1666 esp_trans_deflev = IPSEC_CHECK_DEFAULT(ip4_esp_trans_deflev); 1667 esp_net_deflev = IPSEC_CHECK_DEFAULT(ip4_esp_net_deflev); 1668 ah_trans_deflev = IPSEC_CHECK_DEFAULT(ip4_ah_trans_deflev); 1669 ah_net_deflev = IPSEC_CHECK_DEFAULT(ip4_ah_net_deflev); 1670 break; 1671 #endif 1672 #ifdef INET6 1673 case AF_INET6: 1674 esp_trans_deflev = IPSEC_CHECK_DEFAULT(ip6_esp_trans_deflev); 1675 esp_net_deflev = IPSEC_CHECK_DEFAULT(ip6_esp_net_deflev); 1676 ah_trans_deflev = IPSEC_CHECK_DEFAULT(ip6_ah_trans_deflev); 1677 ah_net_deflev = IPSEC_CHECK_DEFAULT(ip6_ah_net_deflev); 1678 break; 1679 #endif /* INET6 */ 1680 default: 1681 panic("%s: unknown af %u", __func__, 1682 isr->sp->spidx.src.sa.sa_family); 1683 } 1684 1685 #undef IPSEC_CHECK_DEFAULT 1686 1687 /* set level */ 1688 switch (isr->level) { 1689 case IPSEC_LEVEL_DEFAULT: 1690 switch (isr->saidx.proto) { 1691 case IPPROTO_ESP: 1692 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) 1693 level = esp_net_deflev; 1694 else 1695 level = esp_trans_deflev; 1696 break; 1697 case IPPROTO_AH: 1698 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) 1699 level = ah_net_deflev; 1700 else 1701 level = ah_trans_deflev; 1702 break; 1703 case IPPROTO_IPCOMP: 1704 /* 1705 * we don't really care, as IPcomp document says that 1706 * we shouldn't compress small packets 1707 */ 1708 level = IPSEC_LEVEL_USE; 1709 break; 1710 default: 1711 panic("%s: Illegal protocol defined %u", __func__, 1712 isr->saidx.proto); 1713 } 1714 break; 1715 1716 case IPSEC_LEVEL_USE: 1717 case IPSEC_LEVEL_REQUIRE: 1718 level = isr->level; 1719 break; 1720 case IPSEC_LEVEL_UNIQUE: 1721 level = IPSEC_LEVEL_REQUIRE; 1722 break; 1723 1724 default: 1725 panic("%s: Illegal IPsec level %u", __func__, isr->level); 1726 } 1727 1728 return level; 1729 } 1730 1731 /* 1732 * Check security policy requirements against the actual 1733 * packet contents. Return one if the packet should be 1734 * reject as "invalid"; otherwiser return zero to have the 1735 * packet treated as "valid". 1736 * 1737 * OUT: 1738 * 0: valid 1739 * 1: invalid 1740 */ 1741 int 1742 ipsec_in_reject(const struct secpolicy *sp, const struct mbuf *m) 1743 { 1744 struct ipsecrequest *isr; 1745 1746 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DATA)) { 1747 printf("%s: using SP\n", __func__); 1748 kdebug_secpolicy(sp); 1749 } 1750 1751 /* check policy */ 1752 switch (sp->policy) { 1753 case IPSEC_POLICY_DISCARD: 1754 return 1; 1755 case IPSEC_POLICY_BYPASS: 1756 case IPSEC_POLICY_NONE: 1757 return 0; 1758 } 1759 1760 KASSERTMSG(sp->policy == IPSEC_POLICY_IPSEC, 1761 "invalid policy %u", sp->policy); 1762 1763 /* XXX should compare policy against ipsec header history */ 1764 1765 for (isr = sp->req; isr != NULL; isr = isr->next) { 1766 if (ipsec_get_reqlevel(isr) != IPSEC_LEVEL_REQUIRE) 1767 continue; 1768 switch (isr->saidx.proto) { 1769 case IPPROTO_ESP: 1770 if ((m->m_flags & M_DECRYPTED) == 0) { 1771 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 1772 "ESP m_flags:%x\n", m->m_flags); 1773 return 1; 1774 } 1775 break; 1776 case IPPROTO_AH: 1777 if ((m->m_flags & M_AUTHIPHDR) == 0) { 1778 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 1779 "AH m_flags:%x\n", m->m_flags); 1780 return 1; 1781 } 1782 break; 1783 case IPPROTO_IPCOMP: 1784 /* 1785 * we don't really care, as IPcomp document 1786 * says that we shouldn't compress small 1787 * packets, IPComp policy should always be 1788 * treated as being in "use" level. 1789 */ 1790 break; 1791 } 1792 } 1793 return 0; /* valid */ 1794 } 1795 1796 /* 1797 * Check AH/ESP integrity. 1798 * This function is called from tcp_input(), udp_input(), 1799 * and {ah,esp}4_input for tunnel mode 1800 */ 1801 int 1802 ipsec4_in_reject(struct mbuf *m, struct inpcb *inp) 1803 { 1804 struct secpolicy *sp; 1805 int error; 1806 int result; 1807 1808 KASSERT(m != NULL); 1809 1810 /* get SP for this packet. 1811 * When we are called from ip_forward(), we call 1812 * ipsec_getpolicybyaddr() with IP_FORWARDING flag. 1813 */ 1814 if (inp == NULL) 1815 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND, IP_FORWARDING, &error); 1816 else 1817 sp = ipsec_getpolicybysock(m, IPSEC_DIR_INBOUND, 1818 (struct inpcb_hdr *)inp, &error); 1819 1820 if (sp != NULL) { 1821 result = ipsec_in_reject(sp, m); 1822 if (result) 1823 IPSEC_STATINC(IPSEC_STAT_IN_POLVIO); 1824 KEY_SP_UNREF(&sp); 1825 } else { 1826 result = 0; /* XXX should be panic ? 1827 * -> No, there may be error. */ 1828 } 1829 return result; 1830 } 1831 1832 1833 #ifdef INET6 1834 /* 1835 * Check AH/ESP integrity. 1836 * This function is called from tcp6_input(), udp6_input(), 1837 * and {ah,esp}6_input for tunnel mode 1838 */ 1839 int 1840 ipsec6_in_reject(struct mbuf *m, struct in6pcb *in6p) 1841 { 1842 struct secpolicy *sp = NULL; 1843 int error; 1844 int result; 1845 1846 KASSERT(m != NULL); 1847 1848 /* get SP for this packet. 1849 * When we are called from ip_forward(), we call 1850 * ipsec_getpolicybyaddr() with IP_FORWARDING flag. 1851 */ 1852 if (in6p == NULL) 1853 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND, IP_FORWARDING, &error); 1854 else 1855 sp = ipsec_getpolicybysock(m, IPSEC_DIR_INBOUND, 1856 (struct inpcb_hdr *)in6p, 1857 &error); 1858 1859 if (sp != NULL) { 1860 result = ipsec_in_reject(sp, m); 1861 if (result) 1862 IPSEC_STATINC(IPSEC_STAT_IN_POLVIO); 1863 KEY_SP_UNREF(&sp); 1864 } else { 1865 result = 0; 1866 } 1867 return result; 1868 } 1869 #endif 1870 1871 /* 1872 * compute the byte size to be occupied by IPsec header. 1873 * in case it is tunneled, it includes the size of outer IP header. 1874 * NOTE: SP passed is free in this function. 1875 */ 1876 static size_t 1877 ipsec_hdrsiz(const struct secpolicy *sp) 1878 { 1879 struct ipsecrequest *isr; 1880 size_t siz; 1881 1882 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DATA)) { 1883 printf("%s: using SP\n", __func__); 1884 kdebug_secpolicy(sp); 1885 } 1886 1887 switch (sp->policy) { 1888 case IPSEC_POLICY_DISCARD: 1889 case IPSEC_POLICY_BYPASS: 1890 case IPSEC_POLICY_NONE: 1891 return 0; 1892 } 1893 1894 KASSERTMSG(sp->policy == IPSEC_POLICY_IPSEC, 1895 "invalid policy %u", sp->policy); 1896 1897 siz = 0; 1898 for (isr = sp->req; isr != NULL; isr = isr->next) { 1899 size_t clen = 0; 1900 struct secasvar *sav = NULL; 1901 int error; 1902 1903 switch (isr->saidx.proto) { 1904 case IPPROTO_ESP: 1905 error = key_checkrequest(isr, &sav); 1906 if (error == 0) { 1907 clen = esp_hdrsiz(sav); 1908 KEY_FREESAV(&sav); 1909 } else 1910 clen = esp_hdrsiz(NULL); 1911 break; 1912 case IPPROTO_AH: 1913 error = key_checkrequest(isr, &sav); 1914 if (error == 0) { 1915 clen = ah_hdrsiz(sav); 1916 KEY_FREESAV(&sav); 1917 } else 1918 clen = ah_hdrsiz(NULL); 1919 break; 1920 case IPPROTO_IPCOMP: 1921 clen = sizeof(struct ipcomp); 1922 break; 1923 } 1924 1925 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) { 1926 switch (isr->saidx.dst.sa.sa_family) { 1927 case AF_INET: 1928 clen += sizeof(struct ip); 1929 break; 1930 #ifdef INET6 1931 case AF_INET6: 1932 clen += sizeof(struct ip6_hdr); 1933 break; 1934 #endif 1935 default: 1936 IPSECLOG(LOG_ERR, "unknown AF %d in " 1937 "IPsec tunnel SA\n", 1938 ((const struct sockaddr *)&isr->saidx.dst) 1939 ->sa_family); 1940 break; 1941 } 1942 } 1943 siz += clen; 1944 } 1945 1946 return siz; 1947 } 1948 1949 /* This function is called from ip_forward() and ipsec4_hdrsize_tcp(). */ 1950 size_t 1951 ipsec4_hdrsiz(struct mbuf *m, u_int dir, struct inpcb *inp) 1952 { 1953 struct secpolicy *sp; 1954 int error; 1955 size_t size; 1956 1957 KASSERT(m != NULL); 1958 KASSERTMSG(inp == NULL || inp->inp_socket != NULL, "socket w/o inpcb"); 1959 1960 /* get SP for this packet. 1961 * When we are called from ip_forward(), we call 1962 * ipsec_getpolicybyaddr() with IP_FORWARDING flag. 1963 */ 1964 if (inp == NULL) 1965 sp = ipsec_getpolicybyaddr(m, dir, IP_FORWARDING, &error); 1966 else 1967 sp = ipsec_getpolicybysock(m, dir, 1968 (struct inpcb_hdr *)inp, &error); 1969 1970 if (sp != NULL) { 1971 size = ipsec_hdrsiz(sp); 1972 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DATA, "size:%lu.\n", 1973 (unsigned long)size); 1974 1975 KEY_SP_UNREF(&sp); 1976 } else { 1977 size = 0; /* XXX should be panic ? */ 1978 } 1979 return size; 1980 } 1981 1982 #ifdef INET6 1983 /* This function is called from ipsec6_hdrsize_tcp(), 1984 * and maybe from ip6_forward.() 1985 */ 1986 size_t 1987 ipsec6_hdrsiz(struct mbuf *m, u_int dir, struct in6pcb *in6p) 1988 { 1989 struct secpolicy *sp; 1990 int error; 1991 size_t size; 1992 1993 KASSERT(m != NULL); 1994 KASSERTMSG(in6p == NULL || in6p->in6p_socket != NULL, 1995 "socket w/o inpcb"); 1996 1997 /* get SP for this packet */ 1998 /* XXX Is it right to call with IP_FORWARDING. */ 1999 if (in6p == NULL) 2000 sp = ipsec_getpolicybyaddr(m, dir, IP_FORWARDING, &error); 2001 else 2002 sp = ipsec_getpolicybysock(m, dir, 2003 (struct inpcb_hdr *)in6p, 2004 &error); 2005 2006 if (sp == NULL) 2007 return 0; 2008 size = ipsec_hdrsiz(sp); 2009 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DATA, "size:%zu.\n", size); 2010 KEY_SP_UNREF(&sp); 2011 2012 return size; 2013 } 2014 #endif /*INET6*/ 2015 2016 /* 2017 * Check the variable replay window. 2018 * ipsec_chkreplay() performs replay check before ICV verification. 2019 * ipsec_updatereplay() updates replay bitmap. This must be called after 2020 * ICV verification (it also performs replay check, which is usually done 2021 * beforehand). 2022 * 0 (zero) is returned if packet disallowed, 1 if packet permitted. 2023 * 2024 * based on RFC 2401. 2025 */ 2026 int 2027 ipsec_chkreplay(u_int32_t seq, const struct secasvar *sav) 2028 { 2029 const struct secreplay *replay; 2030 u_int32_t diff; 2031 int fr; 2032 u_int32_t wsizeb; /* constant: bits of window size */ 2033 int frlast; /* constant: last frame */ 2034 2035 IPSEC_SPLASSERT_SOFTNET(__func__); 2036 2037 KASSERT(sav != NULL); 2038 KASSERT(sav->replay != NULL); 2039 2040 replay = sav->replay; 2041 2042 if (replay->wsize == 0) 2043 return 1; /* no need to check replay. */ 2044 2045 /* constant */ 2046 frlast = replay->wsize - 1; 2047 wsizeb = replay->wsize << 3; 2048 2049 /* sequence number of 0 is invalid */ 2050 if (seq == 0) 2051 return 0; 2052 2053 /* first time is always okay */ 2054 if (replay->count == 0) 2055 return 1; 2056 2057 if (seq > replay->lastseq) { 2058 /* larger sequences are okay */ 2059 return 1; 2060 } else { 2061 /* seq is equal or less than lastseq. */ 2062 diff = replay->lastseq - seq; 2063 2064 /* over range to check, i.e. too old or wrapped */ 2065 if (diff >= wsizeb) 2066 return 0; 2067 2068 fr = frlast - diff / 8; 2069 2070 /* this packet already seen ? */ 2071 if ((replay->bitmap)[fr] & (1 << (diff % 8))) 2072 return 0; 2073 2074 /* out of order but good */ 2075 return 1; 2076 } 2077 } 2078 2079 /* 2080 * check replay counter whether to update or not. 2081 * OUT: 0: OK 2082 * 1: NG 2083 */ 2084 int 2085 ipsec_updatereplay(u_int32_t seq, const struct secasvar *sav) 2086 { 2087 struct secreplay *replay; 2088 u_int32_t diff; 2089 int fr; 2090 u_int32_t wsizeb; /* constant: bits of window size */ 2091 int frlast; /* constant: last frame */ 2092 char buf[INET6_ADDRSTRLEN]; 2093 2094 IPSEC_SPLASSERT_SOFTNET(__func__); 2095 2096 KASSERT(sav != NULL); 2097 KASSERT(sav->replay != NULL); 2098 2099 replay = sav->replay; 2100 2101 if (replay->wsize == 0) 2102 goto ok; /* no need to check replay. */ 2103 2104 /* constant */ 2105 frlast = replay->wsize - 1; 2106 wsizeb = replay->wsize << 3; 2107 2108 /* sequence number of 0 is invalid */ 2109 if (seq == 0) 2110 return 1; 2111 2112 /* first time */ 2113 if (replay->count == 0) { 2114 replay->lastseq = seq; 2115 memset(replay->bitmap, 0, replay->wsize); 2116 (replay->bitmap)[frlast] = 1; 2117 goto ok; 2118 } 2119 2120 if (seq > replay->lastseq) { 2121 /* seq is larger than lastseq. */ 2122 diff = seq - replay->lastseq; 2123 2124 /* new larger sequence number */ 2125 if (diff < wsizeb) { 2126 /* In window */ 2127 /* set bit for this packet */ 2128 vshiftl(replay->bitmap, diff, replay->wsize); 2129 (replay->bitmap)[frlast] |= 1; 2130 } else { 2131 /* this packet has a "way larger" */ 2132 memset(replay->bitmap, 0, replay->wsize); 2133 (replay->bitmap)[frlast] = 1; 2134 } 2135 replay->lastseq = seq; 2136 2137 /* larger is good */ 2138 } else { 2139 /* seq is equal or less than lastseq. */ 2140 diff = replay->lastseq - seq; 2141 2142 /* over range to check, i.e. too old or wrapped */ 2143 if (diff >= wsizeb) 2144 return 1; 2145 2146 fr = frlast - diff / 8; 2147 2148 /* this packet already seen ? */ 2149 if ((replay->bitmap)[fr] & (1 << (diff % 8))) 2150 return 1; 2151 2152 /* mark as seen */ 2153 (replay->bitmap)[fr] |= (1 << (diff % 8)); 2154 2155 /* out of order but good */ 2156 } 2157 2158 ok: 2159 if (replay->count == ~0) { 2160 2161 /* set overflow flag */ 2162 replay->overflow++; 2163 2164 /* don't increment, no more packets accepted */ 2165 if ((sav->flags & SADB_X_EXT_CYCSEQ) == 0) 2166 return 1; 2167 2168 IPSECLOG(LOG_WARNING, "replay counter made %d cycle. %s\n", 2169 replay->overflow, ipsec_logsastr(sav, buf, sizeof(buf))); 2170 } 2171 2172 replay->count++; 2173 2174 return 0; 2175 } 2176 2177 /* 2178 * shift variable length bunffer to left. 2179 * IN: bitmap: pointer to the buffer 2180 * nbit: the number of to shift. 2181 * wsize: buffer size (bytes). 2182 */ 2183 static void 2184 vshiftl(unsigned char *bitmap, int nbit, int wsize) 2185 { 2186 int s, j, i; 2187 unsigned char over; 2188 2189 for (j = 0; j < nbit; j += 8) { 2190 s = (nbit - j < 8) ? (nbit - j): 8; 2191 bitmap[0] <<= s; 2192 for (i = 1; i < wsize; i++) { 2193 over = (bitmap[i] >> (8 - s)); 2194 bitmap[i] <<= s; 2195 bitmap[i-1] |= over; 2196 } 2197 } 2198 2199 return; 2200 } 2201 2202 /* Return a printable string for the address. */ 2203 const char * 2204 ipsec_address(const union sockaddr_union *sa, char *buf, size_t size) 2205 { 2206 switch (sa->sa.sa_family) { 2207 #if INET 2208 case AF_INET: 2209 in_print(buf, size, &sa->sin.sin_addr); 2210 return buf; 2211 #endif /* INET */ 2212 2213 #if INET6 2214 case AF_INET6: 2215 in6_print(buf, size, &sa->sin6.sin6_addr); 2216 return buf; 2217 #endif /* INET6 */ 2218 2219 default: 2220 return "(unknown address family)"; 2221 } 2222 } 2223 2224 const char * 2225 ipsec_logsastr(const struct secasvar *sav, char *buf, size_t size) 2226 { 2227 const struct secasindex *saidx = &sav->sah->saidx; 2228 char sbuf[IPSEC_ADDRSTRLEN], dbuf[IPSEC_ADDRSTRLEN]; 2229 2230 KASSERTMSG(saidx->src.sa.sa_family == saidx->dst.sa.sa_family, 2231 "af family mismatch, src %u, dst %u", 2232 saidx->src.sa.sa_family, saidx->dst.sa.sa_family); 2233 2234 snprintf(buf, size, "SA(SPI=%u src=%s dst=%s)", 2235 (u_int32_t)ntohl(sav->spi), 2236 ipsec_address(&saidx->src, sbuf, sizeof(sbuf)), 2237 ipsec_address(&saidx->dst, dbuf, sizeof(dbuf))); 2238 2239 return buf; 2240 } 2241 2242 void 2243 ipsec_dumpmbuf(struct mbuf *m) 2244 { 2245 int totlen; 2246 int i; 2247 u_char *p; 2248 2249 totlen = 0; 2250 printf("---\n"); 2251 while (m) { 2252 p = mtod(m, u_char *); 2253 for (i = 0; i < m->m_len; i++) { 2254 printf("%02x ", p[i]); 2255 totlen++; 2256 if (totlen % 16 == 0) 2257 printf("\n"); 2258 } 2259 m = m->m_next; 2260 } 2261 if (totlen % 16 != 0) 2262 printf("\n"); 2263 printf("---\n"); 2264 } 2265 2266 #ifdef INET6 2267 struct secpolicy * 2268 ipsec6_check_policy(struct mbuf *m, struct in6pcb *in6p, 2269 int flags, int *needipsecp, int *errorp) 2270 { 2271 struct secpolicy *sp = NULL; 2272 int s; 2273 int error = 0; 2274 int needipsec = 0; 2275 2276 if (!ipsec_outdone(m)) { 2277 s = splsoftnet(); 2278 if (in6p != NULL && 2279 ipsec_pcb_skip_ipsec(in6p->in6p_sp, IPSEC_DIR_OUTBOUND)) { 2280 splx(s); 2281 goto skippolicycheck; 2282 } 2283 sp = ipsec6_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags, &error,in6p); 2284 2285 /* 2286 * There are four return cases: 2287 * sp != NULL apply IPsec policy 2288 * sp == NULL, error == 0 no IPsec handling needed 2289 * sp == NULL, error == -EINVAL discard packet w/o error 2290 * sp == NULL, error != 0 discard packet, report error 2291 */ 2292 2293 splx(s); 2294 if (sp == NULL) { 2295 /* 2296 * Caller must check the error return to see if it needs to discard 2297 * the packet. 2298 */ 2299 needipsec = 0; 2300 } else { 2301 needipsec = 1; 2302 } 2303 } 2304 skippolicycheck:; 2305 2306 *errorp = error; 2307 *needipsecp = needipsec; 2308 return sp; 2309 } 2310 2311 int 2312 ipsec6_input(struct mbuf *m) 2313 { 2314 struct secpolicy *sp; 2315 int s, error; 2316 2317 s = splsoftnet(); 2318 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND, IP_FORWARDING, &error); 2319 if (sp != NULL) { 2320 /* 2321 * Check security policy against packet 2322 * attributes. 2323 */ 2324 error = ipsec_in_reject(sp, m); 2325 KEY_SP_UNREF(&sp); 2326 } else { 2327 /* XXX error stat??? */ 2328 error = EINVAL; 2329 IPSECLOG(LOG_DEBUG, "no SP, packet discarded\n");/*XXX*/ 2330 } 2331 splx(s); 2332 2333 return error; 2334 } 2335 #endif /* INET6 */ 2336 2337 2338 2339 /* XXX this stuff doesn't belong here... */ 2340 2341 static struct xformsw *xforms = NULL; 2342 2343 /* 2344 * Register a transform; typically at system startup. 2345 */ 2346 void 2347 xform_register(struct xformsw *xsp) 2348 { 2349 xsp->xf_next = xforms; 2350 xforms = xsp; 2351 } 2352 2353 /* 2354 * Initialize transform support in an sav. 2355 */ 2356 int 2357 xform_init(struct secasvar *sav, int xftype) 2358 { 2359 struct xformsw *xsp; 2360 2361 if (sav->tdb_xform != NULL) /* previously initialized */ 2362 return 0; 2363 for (xsp = xforms; xsp; xsp = xsp->xf_next) 2364 if (xsp->xf_type == xftype) 2365 return (*xsp->xf_init)(sav, xsp); 2366 2367 IPSECLOG(LOG_DEBUG, "no match for xform type %d\n", xftype); 2368 return EINVAL; 2369 } 2370 2371 void 2372 nat_t_ports_get(struct mbuf *m, u_int16_t *dport, u_int16_t *sport) { 2373 struct m_tag *tag; 2374 2375 if ((tag = m_tag_find(m, PACKET_TAG_IPSEC_NAT_T_PORTS, NULL))) { 2376 *sport = ((u_int16_t *)(tag + 1))[0]; 2377 *dport = ((u_int16_t *)(tag + 1))[1]; 2378 } else 2379 *sport = *dport = 0; 2380 } 2381 2382 /* 2383 * XXXJRT This should be done as a protosw init call. 2384 */ 2385 void 2386 ipsec_attach(void) 2387 { 2388 2389 ipsecstat_percpu = percpu_alloc(sizeof(uint64_t) * IPSEC_NSTATS); 2390 2391 sysctl_net_inet_ipsec_setup(NULL); 2392 #ifdef INET6 2393 sysctl_net_inet6_ipsec6_setup(NULL); 2394 #endif 2395 2396 ah_attach(); 2397 esp_attach(); 2398 ipcomp_attach(); 2399 ipe4_attach(); 2400 #ifdef TCP_SIGNATURE 2401 tcpsignature_attach(); 2402 #endif 2403 } 2404
Indexes created Tue Sep 30 11:09:46 GMT 2025