ipsec.c revision 1.84
1 /* $NetBSD: ipsec.c,v 1.84 2017/04/25 05:44:11 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 1.84 2017/04/25 05:44:11 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/malloc.h> 49 #include <sys/mbuf.h> 50 #include <sys/domain.h> 51 #include <sys/protosw.h> 52 #include <sys/socket.h> 53 #include <sys/socketvar.h> 54 #include <sys/errno.h> 55 #include <sys/time.h> 56 #include <sys/kernel.h> 57 #include <sys/syslog.h> 58 #include <sys/sysctl.h> 59 #include <sys/proc.h> 60 #include <sys/kauth.h> 61 62 #include <net/if.h> 63 #include <net/route.h> 64 65 #include <netinet/in.h> 66 #include <netinet/in_systm.h> 67 #include <netinet/ip.h> 68 #include <netinet/ip_var.h> 69 #include <netinet/in_var.h> 70 #include <netinet/udp.h> 71 #include <netinet/udp_var.h> 72 #include <netinet/tcp.h> 73 #include <netinet/udp.h> 74 #include <netinet/ip_icmp.h> 75 #include <netinet/ip_private.h> 76 77 #include <netinet/ip6.h> 78 #ifdef INET6 79 #include <netinet6/ip6_var.h> 80 #endif 81 #include <netinet/in_pcb.h> 82 #ifdef INET6 83 #include <netinet6/in6_pcb.h> 84 #include <netinet/icmp6.h> 85 #endif 86 87 #include <netipsec/ipsec.h> 88 #include <netipsec/ipsec_var.h> 89 #include <netipsec/ipsec_private.h> 90 #ifdef INET6 91 #include <netipsec/ipsec6.h> 92 #endif 93 #include <netipsec/ah_var.h> 94 #include <netipsec/esp_var.h> 95 #include <netipsec/ipcomp.h> /*XXX*/ 96 #include <netipsec/ipcomp_var.h> 97 98 #include <netipsec/key.h> 99 #include <netipsec/keydb.h> 100 #include <netipsec/key_debug.h> 101 102 #include <netipsec/xform.h> 103 104 #include <net/net_osdep.h> 105 106 int ipsec_used = 0; 107 int ipsec_enabled = 1; 108 109 #ifdef IPSEC_DEBUG 110 int ipsec_debug = 1; 111 112 /* 113 * When set to 1, IPsec will send packets with the same sequence number. 114 * This allows to verify if the other side has proper replay attacks detection. 115 */ 116 int ipsec_replay = 0; 117 118 /* 119 * When set 1, IPsec will send packets with corrupted HMAC. 120 * This allows to verify if the other side properly detects modified packets. 121 */ 122 int ipsec_integrity = 0; 123 #else 124 int ipsec_debug = 0; 125 #endif 126 127 percpu_t *ipsecstat_percpu; 128 int ip4_ah_offsetmask = 0; /* maybe IP_DF? */ 129 int ip4_ipsec_dfbit = 2; /* DF bit on encap. 0: clear 1: set 2: copy */ 130 int ip4_esp_trans_deflev = IPSEC_LEVEL_USE; 131 int ip4_esp_net_deflev = IPSEC_LEVEL_USE; 132 int ip4_ah_trans_deflev = IPSEC_LEVEL_USE; 133 int ip4_ah_net_deflev = IPSEC_LEVEL_USE; 134 struct secpolicy ip4_def_policy; 135 int ip4_ipsec_ecn = 0; /* ECN ignore(-1)/forbidden(0)/allowed(1) */ 136 int ip4_esp_randpad = -1; 137 138 u_int ipsec_spdgen = 1; /* SPD generation # */ 139 140 static struct secpolicy *ipsec_checkpcbcache (struct mbuf *, 141 struct inpcbpolicy *, int); 142 static int ipsec_fillpcbcache (struct inpcbpolicy *, struct mbuf *, 143 struct secpolicy *, int); 144 static int ipsec_invalpcbcache (struct inpcbpolicy *, int); 145 146 /* 147 * Crypto support requirements: 148 * 149 * 1 require hardware support 150 * -1 require software support 151 * 0 take anything 152 */ 153 int crypto_support = 0; 154 155 static struct secpolicy *ipsec_getpolicybysock(struct mbuf *, u_int, 156 struct inpcb_hdr *, int *); 157 158 #ifdef __FreeBSD__ 159 /* net.inet.ipsec */ 160 SYSCTL_INT(_net_inet_ipsec, IPSECCTL_ESP_RANDPAD, 161 esp_randpad, CTLFLAG_RW, &ip4_esp_randpad, 0, ""); 162 SYSCTL_INT(_net_inet_ipsec, OID_AUTO, 163 crypto_support, CTLFLAG_RW, &crypto_support,0, ""); 164 SYSCTL_INT(_net_inet_ipsec, OID_AUTO, test_replay, CTLFLAG_RW, &ipsec_replay, 0, 165 "Emulate replay attack"); 166 SYSCTL_INT(_net_inet_ipsec, OID_AUTO, test_integrity, CTLFLAG_RW, 167 &ipsec_integrity, 0, "Emulate man-in-the-middle attack"); 168 #endif /* __FreeBSD__ */ 169 170 #ifdef INET6 171 int ip6_esp_trans_deflev = IPSEC_LEVEL_USE; 172 int ip6_esp_net_deflev = IPSEC_LEVEL_USE; 173 int ip6_ah_trans_deflev = IPSEC_LEVEL_USE; 174 int ip6_ah_net_deflev = IPSEC_LEVEL_USE; 175 struct secpolicy ip6_def_policy; 176 int ip6_ipsec_ecn = 0; /* ECN ignore(-1)/forbidden(0)/allowed(1) */ 177 int ip6_esp_randpad = -1; 178 179 180 #ifdef __FreeBSD__ 181 /* net.inet6.ipsec6 */ 182 SYSCTL_INT(_net_inet6_ipsec6, IPSECCTL_ESP_RANDPAD, 183 esp_randpad, CTLFLAG_RW, &ip6_esp_randpad, 0, ""); 184 #endif /* __FreeBSD__ */ 185 #endif /* INET6 */ 186 187 static int ipsec4_setspidx_inpcb (struct mbuf *, struct inpcb *); 188 #ifdef INET6 189 static int ipsec6_setspidx_in6pcb (struct mbuf *, struct in6pcb *); 190 #endif 191 static int ipsec_setspidx (struct mbuf *, struct secpolicyindex *, int); 192 static void ipsec4_get_ulp (struct mbuf *m, struct secpolicyindex *, int); 193 static int ipsec4_setspidx_ipaddr (struct mbuf *, struct secpolicyindex *); 194 #ifdef INET6 195 static void ipsec6_get_ulp (struct mbuf *m, struct secpolicyindex *, int); 196 static int ipsec6_setspidx_ipaddr (struct mbuf *, struct secpolicyindex *); 197 #endif 198 static void ipsec_delpcbpolicy (struct inpcbpolicy *); 199 static struct secpolicy *ipsec_deepcopy_policy (const struct secpolicy *); 200 static int ipsec_set_policy (struct secpolicy **, int, const void *, size_t, 201 kauth_cred_t); 202 static int ipsec_get_policy (struct secpolicy *, struct mbuf **); 203 static void vshiftl (unsigned char *, int, int); 204 static size_t ipsec_hdrsiz (const struct secpolicy *); 205 206 /* 207 * Try to validate and use cached policy on a PCB. 208 */ 209 static struct secpolicy * 210 ipsec_checkpcbcache(struct mbuf *m, struct inpcbpolicy *pcbsp, int dir) 211 { 212 struct secpolicyindex spidx; 213 214 KASSERT(IPSEC_DIR_IS_VALID(dir)); 215 KASSERT(pcbsp != NULL); 216 KASSERT(dir < sizeof(pcbsp->sp_cache)/sizeof(pcbsp->sp_cache[0])); 217 KASSERT(inph_locked(pcbsp->sp_inph)); 218 219 /* SPD table change invalidate all the caches. */ 220 if (ipsec_spdgen != pcbsp->sp_cache[dir].cachegen) { 221 ipsec_invalpcbcache(pcbsp, dir); 222 return NULL; 223 } 224 if (!pcbsp->sp_cache[dir].cachesp) 225 return NULL; 226 if (pcbsp->sp_cache[dir].cachesp->state != IPSEC_SPSTATE_ALIVE) { 227 ipsec_invalpcbcache(pcbsp, dir); 228 return NULL; 229 } 230 if ((pcbsp->sp_cacheflags & IPSEC_PCBSP_CONNECTED) == 0) { 231 if (!pcbsp->sp_cache[dir].cachesp) 232 return NULL; 233 if (ipsec_setspidx(m, &spidx, 1) != 0) 234 return NULL; 235 236 /* 237 * We have to make an exact match here since the cached rule 238 * might have lower priority than a rule that would otherwise 239 * have matched the packet. 240 */ 241 242 if (memcmp(&pcbsp->sp_cache[dir].cacheidx, &spidx, sizeof(spidx))) 243 return NULL; 244 245 } else { 246 /* 247 * The pcb is connected, and the L4 code is sure that: 248 * - outgoing side uses inp_[lf]addr 249 * - incoming side looks up policy after inpcb lookup 250 * and address pair is know to be stable. We do not need 251 * to generate spidx again, nor check the address match again. 252 * 253 * For IPv4/v6 SOCK_STREAM sockets, this assumptions holds 254 * and there are calls to ipsec_pcbconn() from in_pcbconnect(). 255 */ 256 } 257 258 pcbsp->sp_cache[dir].cachesp->lastused = time_second; 259 pcbsp->sp_cache[dir].cachesp->refcnt++; 260 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_STAMP, 261 "DP cause refcnt++:%d SP:%p\n", 262 pcbsp->sp_cache[dir].cachesp->refcnt, 263 pcbsp->sp_cache[dir].cachesp); 264 return pcbsp->sp_cache[dir].cachesp; 265 } 266 267 static int 268 ipsec_fillpcbcache(struct inpcbpolicy *pcbsp, struct mbuf *m, 269 struct secpolicy *sp, int dir) 270 { 271 272 KASSERT(IPSEC_DIR_IS_INOROUT(dir)); 273 KASSERT(dir < sizeof(pcbsp->sp_cache)/sizeof(pcbsp->sp_cache[0])); 274 KASSERT(inph_locked(pcbsp->sp_inph)); 275 276 if (pcbsp->sp_cache[dir].cachesp) 277 KEY_FREESP(&pcbsp->sp_cache[dir].cachesp); 278 pcbsp->sp_cache[dir].cachesp = NULL; 279 pcbsp->sp_cache[dir].cachehint = IPSEC_PCBHINT_MAYBE; 280 if (ipsec_setspidx(m, &pcbsp->sp_cache[dir].cacheidx, 1) != 0) { 281 return EINVAL; 282 } 283 pcbsp->sp_cache[dir].cachesp = sp; 284 if (pcbsp->sp_cache[dir].cachesp) { 285 pcbsp->sp_cache[dir].cachesp->refcnt++; 286 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_STAMP, 287 "DP cause refcnt++:%d SP:%p\n", 288 pcbsp->sp_cache[dir].cachesp->refcnt, 289 pcbsp->sp_cache[dir].cachesp); 290 291 /* 292 * If the PCB is connected, we can remember a hint to 293 * possibly short-circuit IPsec processing in other places. 294 */ 295 if (pcbsp->sp_cacheflags & IPSEC_PCBSP_CONNECTED) { 296 switch (pcbsp->sp_cache[dir].cachesp->policy) { 297 case IPSEC_POLICY_NONE: 298 case IPSEC_POLICY_BYPASS: 299 pcbsp->sp_cache[dir].cachehint = 300 IPSEC_PCBHINT_NO; 301 break; 302 default: 303 pcbsp->sp_cache[dir].cachehint = 304 IPSEC_PCBHINT_YES; 305 } 306 } 307 } 308 pcbsp->sp_cache[dir].cachegen = ipsec_spdgen; 309 310 return 0; 311 } 312 313 static int 314 ipsec_invalpcbcache(struct inpcbpolicy *pcbsp, int dir) 315 { 316 int i; 317 318 KASSERT(inph_locked(pcbsp->sp_inph)); 319 320 for (i = IPSEC_DIR_INBOUND; i <= IPSEC_DIR_OUTBOUND; i++) { 321 if (dir != IPSEC_DIR_ANY && i != dir) 322 continue; 323 if (pcbsp->sp_cache[i].cachesp) 324 KEY_FREESP(&pcbsp->sp_cache[i].cachesp); 325 pcbsp->sp_cache[i].cachesp = NULL; 326 pcbsp->sp_cache[i].cachehint = IPSEC_PCBHINT_MAYBE; 327 pcbsp->sp_cache[i].cachegen = 0; 328 memset(&pcbsp->sp_cache[i].cacheidx, 0, 329 sizeof(pcbsp->sp_cache[i].cacheidx)); 330 } 331 return 0; 332 } 333 334 void 335 ipsec_pcbconn(struct inpcbpolicy *pcbsp) 336 { 337 338 KASSERT(inph_locked(pcbsp->sp_inph)); 339 340 pcbsp->sp_cacheflags |= IPSEC_PCBSP_CONNECTED; 341 ipsec_invalpcbcache(pcbsp, IPSEC_DIR_ANY); 342 } 343 344 void 345 ipsec_pcbdisconn(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_invalpcbcacheall(void) 356 { 357 358 if (ipsec_spdgen == UINT_MAX) 359 ipsec_spdgen = 1; 360 else 361 ipsec_spdgen++; 362 } 363 364 /* 365 * Return a held reference to the default SP. 366 */ 367 static struct secpolicy * 368 key_allocsp_default(int af, const char *where, int tag) 369 { 370 struct secpolicy *sp; 371 372 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_STAMP, "DP from %s:%u\n", where, tag); 373 374 switch(af) { 375 case AF_INET: 376 sp = &ip4_def_policy; 377 break; 378 #ifdef INET6 379 case AF_INET6: 380 sp = &ip6_def_policy; 381 break; 382 #endif 383 default: 384 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_STAMP, 385 "unexpected protocol family %u\n", af); 386 return NULL; 387 } 388 389 if (sp->policy != IPSEC_POLICY_DISCARD && 390 sp->policy != IPSEC_POLICY_NONE) { 391 ipseclog((LOG_INFO, "fixed system default policy: %d->%d\n", 392 sp->policy, IPSEC_POLICY_NONE)); 393 sp->policy = IPSEC_POLICY_NONE; 394 } 395 sp->refcnt++; 396 397 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_STAMP, "DP returns SP:%p (%u)\n", 398 sp, sp->refcnt); 399 return sp; 400 } 401 #define KEY_ALLOCSP_DEFAULT(af) \ 402 key_allocsp_default((af),__FILE__, __LINE__) 403 404 /* 405 * For OUTBOUND packet having a socket. Searching SPD for packet, 406 * and return a pointer to SP. 407 * OUT: NULL: no apropreate SP found, the following value is set to error. 408 * 0 : bypass 409 * EACCES : discard packet. 410 * ENOENT : ipsec_acquire() in progress, maybe. 411 * others : error occurred. 412 * others: a pointer to SP 413 * 414 * NOTE: IPv6 mapped address concern is implemented here. 415 */ 416 struct secpolicy * 417 ipsec_getpolicy(const struct tdb_ident *tdbi, u_int dir) 418 { 419 struct secpolicy *sp; 420 421 KASSERT(tdbi != NULL); 422 KASSERTMSG(IPSEC_DIR_IS_INOROUT(dir), "invalid direction %u", dir); 423 424 sp = KEY_ALLOCSP2(tdbi->spi, &tdbi->dst, tdbi->proto, dir); 425 if (sp == NULL) /*XXX????*/ 426 sp = KEY_ALLOCSP_DEFAULT(tdbi->dst.sa.sa_family); 427 KASSERT(sp != NULL); 428 return sp; 429 } 430 431 /* 432 * For OUTBOUND packet having a socket. Searching SPD for packet, 433 * and return a pointer to SP. 434 * OUT: NULL: no apropreate SP found, the following value is set to error. 435 * 0 : bypass 436 * EACCES : discard packet. 437 * ENOENT : ipsec_acquire() in progress, maybe. 438 * others : error occurred. 439 * others: a pointer to SP 440 * 441 * NOTE: IPv6 mapped address concern is implemented here. 442 */ 443 static struct secpolicy * 444 ipsec_getpolicybysock(struct mbuf *m, u_int dir, struct inpcb_hdr *inph, 445 int *error) 446 { 447 struct inpcbpolicy *pcbsp = NULL; 448 struct secpolicy *currsp = NULL; /* policy on socket */ 449 struct secpolicy *sp; 450 int af; 451 452 KASSERT(m != NULL); 453 KASSERT(inph != NULL); 454 KASSERT(error != NULL); 455 KASSERTMSG(IPSEC_DIR_IS_INOROUT(dir), "invalid direction %u", dir); 456 457 KASSERT(inph->inph_socket != NULL); 458 KASSERT(inph_locked(inph)); 459 460 /* XXX FIXME inpcb/in6pcb vs socket*/ 461 af = inph->inph_af; 462 KASSERTMSG(af == AF_INET || af == AF_INET6, 463 "unexpected protocol family %u", af); 464 465 KASSERT(inph->inph_sp != NULL); 466 /* If we have a cached entry, and if it is still valid, use it. */ 467 IPSEC_STATINC(IPSEC_STAT_SPDCACHELOOKUP); 468 currsp = ipsec_checkpcbcache(m, inph->inph_sp, dir); 469 if (currsp) { 470 *error = 0; 471 return currsp; 472 } 473 IPSEC_STATINC(IPSEC_STAT_SPDCACHEMISS); 474 475 switch (af) { 476 case AF_INET: { 477 struct inpcb *in4p = (struct inpcb *)inph; 478 /* set spidx in pcb */ 479 *error = ipsec4_setspidx_inpcb(m, in4p); 480 pcbsp = in4p->inp_sp; 481 break; 482 } 483 484 #if defined(INET6) 485 case AF_INET6: { 486 struct in6pcb *in6p = (struct in6pcb *)inph; 487 /* set spidx in pcb */ 488 *error = ipsec6_setspidx_in6pcb(m, in6p); 489 pcbsp = in6p->in6p_sp; 490 break; 491 } 492 #endif 493 default: 494 *error = EPFNOSUPPORT; 495 break; 496 } 497 if (*error) 498 return NULL; 499 500 KASSERT(pcbsp != NULL); 501 switch (dir) { 502 case IPSEC_DIR_INBOUND: 503 currsp = pcbsp->sp_in; 504 break; 505 case IPSEC_DIR_OUTBOUND: 506 currsp = pcbsp->sp_out; 507 break; 508 } 509 KASSERT(currsp != NULL); 510 511 if (pcbsp->priv) { /* when privilieged socket */ 512 switch (currsp->policy) { 513 case IPSEC_POLICY_BYPASS: 514 case IPSEC_POLICY_IPSEC: 515 currsp->refcnt++; 516 sp = currsp; 517 break; 518 519 case IPSEC_POLICY_ENTRUST: 520 /* look for a policy in SPD */ 521 sp = KEY_ALLOCSP(&currsp->spidx, dir); 522 if (sp == NULL) /* no SP found */ 523 sp = KEY_ALLOCSP_DEFAULT(af); 524 break; 525 526 default: 527 ipseclog((LOG_ERR, "%s: Invalid policy for PCB %d\n", 528 __func__, currsp->policy)); 529 *error = EINVAL; 530 return NULL; 531 } 532 } else { /* unpriv, SPD has policy */ 533 sp = KEY_ALLOCSP(&currsp->spidx, dir); 534 if (sp == NULL) { /* no SP found */ 535 switch (currsp->policy) { 536 case IPSEC_POLICY_BYPASS: 537 ipseclog((LOG_ERR, "%s: Illegal policy for " 538 "non-priviliged defined %d\n", __func__, 539 currsp->policy)); 540 *error = EINVAL; 541 return NULL; 542 543 case IPSEC_POLICY_ENTRUST: 544 sp = KEY_ALLOCSP_DEFAULT(af); 545 break; 546 547 case IPSEC_POLICY_IPSEC: 548 currsp->refcnt++; 549 sp = currsp; 550 break; 551 552 default: 553 ipseclog((LOG_ERR, "%s: Invalid policy for " 554 "PCB %d\n", __func__, currsp->policy)); 555 *error = EINVAL; 556 return NULL; 557 } 558 } 559 } 560 KASSERTMSG(sp != NULL, "null SP (priv %u policy %u", pcbsp->priv, 561 currsp->policy); 562 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_STAMP, 563 "DP (priv %u policy %u) allocates SP:%p (refcnt %u)\n", 564 pcbsp->priv, currsp->policy, sp, sp->refcnt); 565 ipsec_fillpcbcache(pcbsp, m, sp, dir); 566 return sp; 567 } 568 569 /* 570 * For FORWADING packet or OUTBOUND without a socket. Searching SPD for packet, 571 * and return a pointer to SP. 572 * OUT: positive: a pointer to the entry for security policy leaf matched. 573 * NULL: no apropreate SP found, the following value is set to error. 574 * 0 : bypass 575 * EACCES : discard packet. 576 * ENOENT : ipsec_acquire() in progress, maybe. 577 * others : error occurred. 578 */ 579 struct secpolicy * 580 ipsec_getpolicybyaddr(struct mbuf *m, u_int dir, int flag, int *error) 581 { 582 struct secpolicyindex spidx; 583 struct secpolicy *sp; 584 585 KASSERT(m != NULL); 586 KASSERT(error != NULL); 587 KASSERTMSG(IPSEC_DIR_IS_INOROUT(dir), "invalid direction %u", dir); 588 589 sp = NULL; 590 591 /* Make an index to look for a policy. */ 592 *error = ipsec_setspidx(m, &spidx, (flag & IP_FORWARDING) ? 0 : 1); 593 if (*error != 0) { 594 DPRINTF(("%s: setpidx failed, dir %u flag %u\n", __func__, 595 dir, flag)); 596 memset(&spidx, 0, sizeof (spidx)); 597 return NULL; 598 } 599 600 spidx.dir = dir; 601 602 if (key_havesp(dir)) { 603 sp = KEY_ALLOCSP(&spidx, dir); 604 } 605 606 if (sp == NULL) /* no SP found, use system default */ 607 sp = KEY_ALLOCSP_DEFAULT(spidx.dst.sa.sa_family); 608 KASSERT(sp != NULL); 609 return sp; 610 } 611 612 struct secpolicy * 613 ipsec4_checkpolicy(struct mbuf *m, u_int dir, u_int flag, int *error, 614 struct inpcb *inp) 615 { 616 struct secpolicy *sp; 617 618 *error = 0; 619 620 if (inp == NULL) { 621 sp = ipsec_getpolicybyaddr(m, dir, flag, error); 622 } else { 623 KASSERT(inp->inp_socket != NULL); 624 sp = ipsec_getpolicybysock(m, dir, (struct inpcb_hdr *)inp, error); 625 } 626 if (sp == NULL) { 627 KASSERTMSG(*error != 0, "getpolicy failed w/o error"); 628 IPSEC_STATINC(IPSEC_STAT_OUT_INVAL); 629 return NULL; 630 } 631 KASSERTMSG(*error == 0, "sp w/ error set to %u", *error); 632 switch (sp->policy) { 633 case IPSEC_POLICY_ENTRUST: 634 default: 635 printf("%s: invalid policy %u\n", __func__, sp->policy); 636 /* fall thru... */ 637 case IPSEC_POLICY_DISCARD: 638 IPSEC_STATINC(IPSEC_STAT_OUT_POLVIO); 639 *error = -EINVAL; /* packet is discarded by caller */ 640 break; 641 case IPSEC_POLICY_BYPASS: 642 case IPSEC_POLICY_NONE: 643 KEY_FREESP(&sp); 644 sp = NULL; /* NB: force NULL result */ 645 break; 646 case IPSEC_POLICY_IPSEC: 647 if (sp->req == NULL) /* acquire an SA */ 648 *error = key_spdacquire(sp); 649 break; 650 } 651 if (*error != 0) { 652 KEY_FREESP(&sp); 653 sp = NULL; 654 DPRINTF(("%s: done, error %d\n", __func__, *error)); 655 } 656 return sp; 657 } 658 659 int 660 ipsec4_output(struct mbuf *m, struct inpcb *inp, int flags, 661 struct secpolicy **sp_out, u_long *mtu, bool *natt_frag, bool *done) 662 { 663 const struct ip *ip = mtod(m, const struct ip *); 664 struct secpolicy *sp = NULL; 665 int error, s; 666 667 /* 668 * Check the security policy (SP) for the packet and, if required, 669 * do IPsec-related processing. There are two cases here; the first 670 * time a packet is sent through it will be untagged and handled by 671 * ipsec4_checkpolicy(). If the packet is resubmitted to ip_output 672 * (e.g. after AH, ESP, etc. processing), there will be a tag to 673 * bypass the lookup and related policy checking. 674 */ 675 if (ipsec_outdone(m)) { 676 return 0; 677 } 678 s = splsoftnet(); 679 if (inp && IPSEC_PCB_SKIP_IPSEC(inp->inp_sp, IPSEC_DIR_OUTBOUND)) { 680 splx(s); 681 return 0; 682 } 683 sp = ipsec4_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags, &error, inp); 684 685 /* 686 * There are four return cases: 687 * sp != NULL apply IPsec policy 688 * sp == NULL, error == 0 no IPsec handling needed 689 * sp == NULL, error == -EINVAL discard packet w/o error 690 * sp == NULL, error != 0 discard packet, report error 691 */ 692 if (sp == NULL) { 693 splx(s); 694 if (error) { 695 /* 696 * Hack: -EINVAL is used to signal that a packet 697 * should be silently discarded. This is typically 698 * because we asked key management for an SA and 699 * it was delayed (e.g. kicked up to IKE). 700 */ 701 if (error == -EINVAL) 702 error = 0; 703 m_freem(m); 704 *done = true; 705 return error; 706 } 707 /* No IPsec processing for this packet. */ 708 return 0; 709 } 710 *sp_out = sp; 711 712 /* 713 * NAT-T ESP fragmentation: do not do IPSec processing now, 714 * we will do it on each fragmented packet. 715 */ 716 if (sp->req->sav && (sp->req->sav->natt_type & 717 (UDP_ENCAP_ESPINUDP|UDP_ENCAP_ESPINUDP_NON_IKE))) { 718 if (ntohs(ip->ip_len) > sp->req->sav->esp_frag) { 719 *mtu = sp->req->sav->esp_frag; 720 *natt_frag = true; 721 splx(s); 722 return 0; 723 } 724 } 725 726 /* 727 * Do delayed checksums now because we send before 728 * this is done in the normal processing path. 729 */ 730 if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 731 in_delayed_cksum(m); 732 m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 733 } 734 735 /* Note: callee frees mbuf */ 736 error = ipsec4_process_packet(m, sp->req, flags, 0); 737 /* 738 * Preserve KAME behaviour: ENOENT can be returned 739 * when an SA acquire is in progress. Don't propagate 740 * this to user-level; it confuses applications. 741 * 742 * XXX this will go away when the SADB is redone. 743 */ 744 if (error == ENOENT) 745 error = 0; 746 splx(s); 747 *done = true; 748 return error; 749 } 750 751 int 752 ipsec4_input(struct mbuf *m, int flags) 753 { 754 struct m_tag *mtag; 755 struct tdb_ident *tdbi; 756 struct secpolicy *sp; 757 int error, s; 758 759 /* 760 * Check if the packet has already had IPsec processing done. 761 * If so, then just pass it along. This tag gets set during AH, 762 * ESP, etc. input handling, before the packet is returned to 763 * the IP input queue for delivery. 764 */ 765 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL); 766 s = splsoftnet(); 767 if (mtag != NULL) { 768 tdbi = (struct tdb_ident *)(mtag + 1); 769 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND); 770 } else { 771 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND, 772 IP_FORWARDING, &error); 773 } 774 if (sp == NULL) { 775 splx(s); 776 return EINVAL; 777 } 778 779 /* 780 * Check security policy against packet attributes. 781 */ 782 error = ipsec_in_reject(sp, m); 783 KEY_FREESP(&sp); 784 splx(s); 785 if (error) { 786 return error; 787 } 788 789 if (flags == 0) { 790 /* We are done. */ 791 return 0; 792 } 793 794 /* 795 * Peek at the outbound SP for this packet to determine if 796 * it is a Fast Forward candidate. 797 */ 798 mtag = m_tag_find(m, PACKET_TAG_IPSEC_PENDING_TDB, NULL); 799 if (mtag != NULL) { 800 m->m_flags &= ~M_CANFASTFWD; 801 return 0; 802 } 803 804 s = splsoftnet(); 805 sp = ipsec4_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags, &error, NULL); 806 if (sp != NULL) { 807 m->m_flags &= ~M_CANFASTFWD; 808 KEY_FREESP(&sp); 809 } 810 splx(s); 811 return 0; 812 } 813 814 int 815 ipsec4_forward(struct mbuf *m, int *destmtu) 816 { 817 /* 818 * If the packet is routed over IPsec tunnel, tell the 819 * originator the tunnel MTU. 820 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz 821 * XXX quickhack!!! 822 */ 823 struct secpolicy *sp; 824 size_t ipsechdr; 825 int error; 826 827 sp = ipsec4_getpolicybyaddr(m, 828 IPSEC_DIR_OUTBOUND, IP_FORWARDING, &error); 829 if (sp == NULL) { 830 return EINVAL; 831 } 832 833 /* Count IPsec header size. */ 834 ipsechdr = ipsec4_hdrsiz(m, IPSEC_DIR_OUTBOUND, NULL); 835 836 /* 837 * Find the correct route for outer IPv4 header, compute tunnel MTU. 838 */ 839 if (sp->req && sp->req->sav && sp->req->sav->sah) { 840 struct route *ro; 841 struct rtentry *rt; 842 843 ro = &sp->req->sav->sah->sa_route; 844 rt = rtcache_validate(ro); 845 if (rt && rt->rt_ifp) { 846 *destmtu = rt->rt_rmx.rmx_mtu ? 847 rt->rt_rmx.rmx_mtu : rt->rt_ifp->if_mtu; 848 *destmtu -= ipsechdr; 849 } 850 rtcache_unref(rt, ro); 851 } 852 KEY_FREESP(&sp); 853 return 0; 854 } 855 856 #ifdef INET6 857 struct secpolicy * 858 ipsec6_checkpolicy(struct mbuf *m, u_int dir, u_int flag, int *error, 859 struct in6pcb *in6p) 860 { 861 struct secpolicy *sp; 862 863 *error = 0; 864 865 if (in6p == NULL) { 866 sp = ipsec_getpolicybyaddr(m, dir, flag, error); 867 } else { 868 KASSERT(in6p->in6p_socket != NULL); 869 sp = ipsec_getpolicybysock(m, dir, (struct inpcb_hdr *)in6p, error); 870 } 871 if (sp == NULL) { 872 KASSERTMSG(*error != 0, "getpolicy failed w/o error"); 873 IPSEC_STATINC(IPSEC_STAT_OUT_INVAL); 874 return NULL; 875 } 876 KASSERTMSG(*error == 0, "sp w/ error set to %u", *error); 877 switch (sp->policy) { 878 case IPSEC_POLICY_ENTRUST: 879 default: 880 printf("%s: invalid policy %u\n", __func__, sp->policy); 881 /* fall thru... */ 882 case IPSEC_POLICY_DISCARD: 883 IPSEC_STATINC(IPSEC_STAT_OUT_POLVIO); 884 *error = -EINVAL; /* packet is discarded by caller */ 885 break; 886 case IPSEC_POLICY_BYPASS: 887 case IPSEC_POLICY_NONE: 888 KEY_FREESP(&sp); 889 sp = NULL; /* NB: force NULL result */ 890 break; 891 case IPSEC_POLICY_IPSEC: 892 if (sp->req == NULL) /* acquire an SA */ 893 *error = key_spdacquire(sp); 894 break; 895 } 896 if (*error != 0) { 897 KEY_FREESP(&sp); 898 sp = NULL; 899 DPRINTF(("%s: done, error %d\n", __func__, *error)); 900 } 901 return sp; 902 } 903 #endif /* INET6 */ 904 905 static int 906 ipsec4_setspidx_inpcb(struct mbuf *m, struct inpcb *pcb) 907 { 908 int error; 909 910 KASSERT(pcb != NULL); 911 KASSERT(pcb->inp_sp != NULL); 912 KASSERT(pcb->inp_sp->sp_out != NULL); 913 KASSERT(pcb->inp_sp->sp_in != NULL); 914 915 error = ipsec_setspidx(m, &pcb->inp_sp->sp_in->spidx, 1); 916 if (error == 0) { 917 pcb->inp_sp->sp_in->spidx.dir = IPSEC_DIR_INBOUND; 918 pcb->inp_sp->sp_out->spidx = pcb->inp_sp->sp_in->spidx; 919 pcb->inp_sp->sp_out->spidx.dir = IPSEC_DIR_OUTBOUND; 920 } else { 921 memset(&pcb->inp_sp->sp_in->spidx, 0, 922 sizeof (pcb->inp_sp->sp_in->spidx)); 923 memset(&pcb->inp_sp->sp_out->spidx, 0, 924 sizeof (pcb->inp_sp->sp_in->spidx)); 925 } 926 return error; 927 } 928 929 #ifdef INET6 930 static int 931 ipsec6_setspidx_in6pcb(struct mbuf *m, struct in6pcb *pcb) 932 { 933 struct secpolicyindex *spidx; 934 int error; 935 936 KASSERT(pcb != NULL); 937 KASSERT(pcb->in6p_sp != NULL); 938 KASSERT(pcb->in6p_sp->sp_out != NULL); 939 KASSERT(pcb->in6p_sp->sp_in != NULL); 940 941 memset(&pcb->in6p_sp->sp_in->spidx, 0, sizeof(*spidx)); 942 memset(&pcb->in6p_sp->sp_out->spidx, 0, sizeof(*spidx)); 943 944 spidx = &pcb->in6p_sp->sp_in->spidx; 945 error = ipsec_setspidx(m, spidx, 1); 946 if (error) 947 goto bad; 948 spidx->dir = IPSEC_DIR_INBOUND; 949 950 spidx = &pcb->in6p_sp->sp_out->spidx; 951 error = ipsec_setspidx(m, spidx, 1); 952 if (error) 953 goto bad; 954 spidx->dir = IPSEC_DIR_OUTBOUND; 955 956 return 0; 957 958 bad: 959 memset(&pcb->in6p_sp->sp_in->spidx, 0, sizeof(*spidx)); 960 memset(&pcb->in6p_sp->sp_out->spidx, 0, sizeof(*spidx)); 961 return error; 962 } 963 #endif 964 965 /* 966 * configure security policy index (src/dst/proto/sport/dport) 967 * by looking at the content of mbuf. 968 * the caller is responsible for error recovery (like clearing up spidx). 969 */ 970 static int 971 ipsec_setspidx(struct mbuf *m, struct secpolicyindex *spidx, int needport) 972 { 973 struct ip *ip = NULL; 974 struct ip ipbuf; 975 u_int v; 976 struct mbuf *n; 977 int len; 978 int error; 979 980 KASSERT(m != NULL); 981 982 /* 983 * validate m->m_pkthdr.len. we see incorrect length if we 984 * mistakenly call this function with inconsistent mbuf chain 985 * (like 4.4BSD tcp/udp processing). XXX should we panic here? 986 */ 987 len = 0; 988 for (n = m; n; n = n->m_next) 989 len += n->m_len; 990 if (m->m_pkthdr.len != len) { 991 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 992 "total of m_len(%d) != pkthdr.len(%d), ignored.\n", 993 len, m->m_pkthdr.len); 994 return EINVAL; 995 } 996 997 if (m->m_pkthdr.len < sizeof(struct ip)) { 998 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 999 "pkthdr.len(%d) < sizeof(struct ip), ignored.\n", 1000 m->m_pkthdr.len); 1001 return EINVAL; 1002 } 1003 1004 if (m->m_len >= sizeof(*ip)) 1005 ip = mtod(m, struct ip *); 1006 else { 1007 m_copydata(m, 0, sizeof(ipbuf), &ipbuf); 1008 ip = &ipbuf; 1009 } 1010 v = ip->ip_v; 1011 switch (v) { 1012 case 4: 1013 error = ipsec4_setspidx_ipaddr(m, spidx); 1014 if (error) 1015 return error; 1016 ipsec4_get_ulp(m, spidx, needport); 1017 return 0; 1018 #ifdef INET6 1019 case 6: 1020 if (m->m_pkthdr.len < sizeof(struct ip6_hdr)) { 1021 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 1022 "pkthdr.len(%d) < sizeof(struct ip6_hdr), " 1023 "ignored.\n", m->m_pkthdr.len); 1024 return EINVAL; 1025 } 1026 error = ipsec6_setspidx_ipaddr(m, spidx); 1027 if (error) 1028 return error; 1029 ipsec6_get_ulp(m, spidx, needport); 1030 return 0; 1031 #endif 1032 default: 1033 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 1034 "unknown IP version %u, ignored.\n", v); 1035 return EINVAL; 1036 } 1037 } 1038 1039 static void 1040 ipsec4_get_ulp(struct mbuf *m, struct secpolicyindex *spidx, int needport) 1041 { 1042 u_int8_t nxt; 1043 int off; 1044 1045 /* sanity check */ 1046 KASSERT(m != NULL); 1047 KASSERTMSG(m->m_pkthdr.len >= sizeof(struct ip), "packet too short"); 1048 1049 /* NB: ip_input() flips it into host endian XXX need more checking */ 1050 if (m->m_len >= sizeof(struct ip)) { 1051 struct ip *ip = mtod(m, struct ip *); 1052 if (ip->ip_off & htons(IP_MF | IP_OFFMASK)) 1053 goto done; 1054 off = ip->ip_hl << 2; 1055 nxt = ip->ip_p; 1056 } else { 1057 struct ip ih; 1058 1059 m_copydata(m, 0, sizeof (struct ip), &ih); 1060 if (ih.ip_off & htons(IP_MF | IP_OFFMASK)) 1061 goto done; 1062 off = ih.ip_hl << 2; 1063 nxt = ih.ip_p; 1064 } 1065 1066 while (off < m->m_pkthdr.len) { 1067 struct ip6_ext ip6e; 1068 struct tcphdr th; 1069 struct udphdr uh; 1070 struct icmp icmph; 1071 1072 switch (nxt) { 1073 case IPPROTO_TCP: 1074 spidx->ul_proto = nxt; 1075 if (!needport) 1076 goto done_proto; 1077 if (off + sizeof(struct tcphdr) > m->m_pkthdr.len) 1078 goto done; 1079 m_copydata(m, off, sizeof (th), &th); 1080 spidx->src.sin.sin_port = th.th_sport; 1081 spidx->dst.sin.sin_port = th.th_dport; 1082 return; 1083 case IPPROTO_UDP: 1084 spidx->ul_proto = nxt; 1085 if (!needport) 1086 goto done_proto; 1087 if (off + sizeof(struct udphdr) > m->m_pkthdr.len) 1088 goto done; 1089 m_copydata(m, off, sizeof (uh), &uh); 1090 spidx->src.sin.sin_port = uh.uh_sport; 1091 spidx->dst.sin.sin_port = uh.uh_dport; 1092 return; 1093 case IPPROTO_AH: 1094 if (m->m_pkthdr.len > off + sizeof(ip6e)) 1095 goto done; 1096 /* XXX sigh, this works but is totally bogus */ 1097 m_copydata(m, off, sizeof(ip6e), &ip6e); 1098 off += (ip6e.ip6e_len + 2) << 2; 1099 nxt = ip6e.ip6e_nxt; 1100 break; 1101 case IPPROTO_ICMP: 1102 spidx->ul_proto = nxt; 1103 if (off + sizeof(struct icmp) > m->m_pkthdr.len) 1104 return; 1105 m_copydata(m, off, sizeof(icmph), &icmph); 1106 ((struct sockaddr_in *)&spidx->src)->sin_port = 1107 htons((uint16_t)icmph.icmp_type); 1108 ((struct sockaddr_in *)&spidx->dst)->sin_port = 1109 htons((uint16_t)icmph.icmp_code); 1110 return; 1111 default: 1112 /* XXX intermediate headers??? */ 1113 spidx->ul_proto = nxt; 1114 goto done_proto; 1115 } 1116 } 1117 done: 1118 spidx->ul_proto = IPSEC_ULPROTO_ANY; 1119 done_proto: 1120 spidx->src.sin.sin_port = IPSEC_PORT_ANY; 1121 spidx->dst.sin.sin_port = IPSEC_PORT_ANY; 1122 } 1123 1124 /* assumes that m is sane */ 1125 static int 1126 ipsec4_setspidx_ipaddr(struct mbuf *m, struct secpolicyindex *spidx) 1127 { 1128 static const struct sockaddr_in template = { 1129 sizeof (struct sockaddr_in), 1130 AF_INET, 1131 0, { 0 }, { 0, 0, 0, 0, 0, 0, 0, 0 } 1132 }; 1133 1134 spidx->src.sin = template; 1135 spidx->dst.sin = template; 1136 1137 if (m->m_len < sizeof (struct ip)) { 1138 m_copydata(m, offsetof(struct ip, ip_src), 1139 sizeof (struct in_addr), 1140 &spidx->src.sin.sin_addr); 1141 m_copydata(m, offsetof(struct ip, ip_dst), 1142 sizeof (struct in_addr), 1143 &spidx->dst.sin.sin_addr); 1144 } else { 1145 struct ip *ip = mtod(m, struct ip *); 1146 spidx->src.sin.sin_addr = ip->ip_src; 1147 spidx->dst.sin.sin_addr = ip->ip_dst; 1148 } 1149 1150 spidx->prefs = sizeof(struct in_addr) << 3; 1151 spidx->prefd = sizeof(struct in_addr) << 3; 1152 1153 return 0; 1154 } 1155 1156 #ifdef INET6 1157 static void 1158 ipsec6_get_ulp(struct mbuf *m, struct secpolicyindex *spidx, 1159 int needport) 1160 { 1161 int off, nxt; 1162 struct tcphdr th; 1163 struct udphdr uh; 1164 struct icmp6_hdr icmph; 1165 1166 KASSERT(m != NULL); 1167 1168 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DUMP)) { 1169 printf("%s:\n", __func__); 1170 kdebug_mbuf(m); 1171 } 1172 1173 /* set default */ 1174 spidx->ul_proto = IPSEC_ULPROTO_ANY; 1175 ((struct sockaddr_in6 *)&spidx->src)->sin6_port = IPSEC_PORT_ANY; 1176 ((struct sockaddr_in6 *)&spidx->dst)->sin6_port = IPSEC_PORT_ANY; 1177 1178 nxt = -1; 1179 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt); 1180 if (off < 0 || m->m_pkthdr.len < off) 1181 return; 1182 1183 switch (nxt) { 1184 case IPPROTO_TCP: 1185 spidx->ul_proto = nxt; 1186 if (!needport) 1187 break; 1188 if (off + sizeof(struct tcphdr) > m->m_pkthdr.len) 1189 break; 1190 m_copydata(m, off, sizeof(th), &th); 1191 ((struct sockaddr_in6 *)&spidx->src)->sin6_port = th.th_sport; 1192 ((struct sockaddr_in6 *)&spidx->dst)->sin6_port = th.th_dport; 1193 break; 1194 case IPPROTO_UDP: 1195 spidx->ul_proto = nxt; 1196 if (!needport) 1197 break; 1198 if (off + sizeof(struct udphdr) > m->m_pkthdr.len) 1199 break; 1200 m_copydata(m, off, sizeof(uh), &uh); 1201 ((struct sockaddr_in6 *)&spidx->src)->sin6_port = uh.uh_sport; 1202 ((struct sockaddr_in6 *)&spidx->dst)->sin6_port = uh.uh_dport; 1203 break; 1204 case IPPROTO_ICMPV6: 1205 spidx->ul_proto = nxt; 1206 if (off + sizeof(struct icmp6_hdr) > m->m_pkthdr.len) 1207 break; 1208 m_copydata(m, off, sizeof(icmph), &icmph); 1209 ((struct sockaddr_in6 *)&spidx->src)->sin6_port = 1210 htons((uint16_t)icmph.icmp6_type); 1211 ((struct sockaddr_in6 *)&spidx->dst)->sin6_port = 1212 htons((uint16_t)icmph.icmp6_code); 1213 break; 1214 default: 1215 /* XXX intermediate headers??? */ 1216 spidx->ul_proto = nxt; 1217 break; 1218 } 1219 } 1220 1221 /* assumes that m is sane */ 1222 static int 1223 ipsec6_setspidx_ipaddr(struct mbuf *m, struct secpolicyindex *spidx) 1224 { 1225 struct ip6_hdr *ip6 = NULL; 1226 struct ip6_hdr ip6buf; 1227 struct sockaddr_in6 *sin6; 1228 1229 if (m->m_len >= sizeof(*ip6)) 1230 ip6 = mtod(m, struct ip6_hdr *); 1231 else { 1232 m_copydata(m, 0, sizeof(ip6buf), &ip6buf); 1233 ip6 = &ip6buf; 1234 } 1235 1236 sin6 = (struct sockaddr_in6 *)&spidx->src; 1237 memset(sin6, 0, sizeof(*sin6)); 1238 sin6->sin6_family = AF_INET6; 1239 sin6->sin6_len = sizeof(struct sockaddr_in6); 1240 memcpy(&sin6->sin6_addr, &ip6->ip6_src, sizeof(ip6->ip6_src)); 1241 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) { 1242 sin6->sin6_addr.s6_addr16[1] = 0; 1243 sin6->sin6_scope_id = ntohs(ip6->ip6_src.s6_addr16[1]); 1244 } 1245 spidx->prefs = sizeof(struct in6_addr) << 3; 1246 1247 sin6 = (struct sockaddr_in6 *)&spidx->dst; 1248 memset(sin6, 0, sizeof(*sin6)); 1249 sin6->sin6_family = AF_INET6; 1250 sin6->sin6_len = sizeof(struct sockaddr_in6); 1251 memcpy(&sin6->sin6_addr, &ip6->ip6_dst, sizeof(ip6->ip6_dst)); 1252 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) { 1253 sin6->sin6_addr.s6_addr16[1] = 0; 1254 sin6->sin6_scope_id = ntohs(ip6->ip6_dst.s6_addr16[1]); 1255 } 1256 spidx->prefd = sizeof(struct in6_addr) << 3; 1257 1258 return 0; 1259 } 1260 #endif 1261 1262 static void 1263 ipsec_delpcbpolicy(struct inpcbpolicy *p) 1264 { 1265 free(p, M_SECA); 1266 } 1267 1268 /* initialize policy in PCB */ 1269 int 1270 ipsec_init_policy(struct socket *so, struct inpcbpolicy **policy) 1271 { 1272 struct inpcbpolicy *new; 1273 1274 KASSERT(so != NULL); 1275 KASSERT(policy != NULL); 1276 1277 new = malloc(sizeof(*new), M_SECA, M_NOWAIT|M_ZERO); 1278 if (new == NULL) { 1279 ipseclog((LOG_DEBUG, "%s: No more memory.\n", __func__)); 1280 return ENOBUFS; 1281 } 1282 1283 if (IPSEC_PRIVILEGED_SO(so)) 1284 new->priv = 1; 1285 else 1286 new->priv = 0; 1287 1288 if ((new->sp_in = KEY_NEWSP()) == NULL) { 1289 ipsec_delpcbpolicy(new); 1290 return ENOBUFS; 1291 } 1292 new->sp_in->state = IPSEC_SPSTATE_ALIVE; 1293 new->sp_in->policy = IPSEC_POLICY_ENTRUST; 1294 1295 if ((new->sp_out = KEY_NEWSP()) == NULL) { 1296 KEY_FREESP(&new->sp_in); 1297 ipsec_delpcbpolicy(new); 1298 return ENOBUFS; 1299 } 1300 new->sp_out->state = IPSEC_SPSTATE_ALIVE; 1301 new->sp_out->policy = IPSEC_POLICY_ENTRUST; 1302 1303 *policy = new; 1304 1305 return 0; 1306 } 1307 1308 /* copy old ipsec policy into new */ 1309 int 1310 ipsec_copy_policy(const struct inpcbpolicy *old, struct inpcbpolicy *new) 1311 { 1312 struct secpolicy *sp; 1313 1314 sp = ipsec_deepcopy_policy(old->sp_in); 1315 if (sp) { 1316 KEY_FREESP(&new->sp_in); 1317 new->sp_in = sp; 1318 } else 1319 return ENOBUFS; 1320 1321 sp = ipsec_deepcopy_policy(old->sp_out); 1322 if (sp) { 1323 KEY_FREESP(&new->sp_out); 1324 new->sp_out = sp; 1325 } else 1326 return ENOBUFS; 1327 1328 new->priv = old->priv; 1329 1330 return 0; 1331 } 1332 1333 /* deep-copy a policy in PCB */ 1334 static struct secpolicy * 1335 ipsec_deepcopy_policy(const struct secpolicy *src) 1336 { 1337 struct ipsecrequest *newchain = NULL; 1338 const struct ipsecrequest *p; 1339 struct ipsecrequest **q; 1340 struct ipsecrequest *r; 1341 struct secpolicy *dst; 1342 1343 if (src == NULL) 1344 return NULL; 1345 dst = KEY_NEWSP(); 1346 if (dst == NULL) 1347 return NULL; 1348 1349 /* 1350 * deep-copy IPsec request chain. This is required since struct 1351 * ipsecrequest is not reference counted. 1352 */ 1353 q = &newchain; 1354 for (p = src->req; p; p = p->next) { 1355 *q = malloc(sizeof(**q), M_SECA, M_NOWAIT|M_ZERO); 1356 if (*q == NULL) 1357 goto fail; 1358 (*q)->next = NULL; 1359 1360 (*q)->saidx.proto = p->saidx.proto; 1361 (*q)->saidx.mode = p->saidx.mode; 1362 (*q)->level = p->level; 1363 (*q)->saidx.reqid = p->saidx.reqid; 1364 1365 memcpy(&(*q)->saidx.src, &p->saidx.src, sizeof((*q)->saidx.src)); 1366 memcpy(&(*q)->saidx.dst, &p->saidx.dst, sizeof((*q)->saidx.dst)); 1367 1368 (*q)->sav = NULL; 1369 (*q)->sp = dst; 1370 1371 q = &((*q)->next); 1372 } 1373 1374 dst->req = newchain; 1375 dst->state = src->state; 1376 dst->policy = src->policy; 1377 /* do not touch the refcnt fields */ 1378 1379 return dst; 1380 1381 fail: 1382 for (q = &newchain; *q; q = &r) { 1383 r = (*q)->next; 1384 free(*q, M_SECA); 1385 } 1386 return NULL; 1387 } 1388 1389 /* set policy and ipsec request if present. */ 1390 static int 1391 ipsec_set_policy( 1392 struct secpolicy **policy, 1393 int optname, 1394 const void *request, 1395 size_t len, 1396 kauth_cred_t cred 1397 ) 1398 { 1399 const struct sadb_x_policy *xpl; 1400 struct secpolicy *newsp = NULL; 1401 int error; 1402 1403 /* sanity check. */ 1404 if (policy == NULL || *policy == NULL || request == NULL) 1405 return EINVAL; 1406 if (len < sizeof(*xpl)) 1407 return EINVAL; 1408 xpl = (const struct sadb_x_policy *)request; 1409 1410 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DUMP)) { 1411 printf("%s: passed policy\n", __func__); 1412 kdebug_sadb_x_policy((const struct sadb_ext *)xpl); 1413 } 1414 1415 /* check policy type */ 1416 /* ipsec_set_policy() accepts IPSEC, ENTRUST and BYPASS. */ 1417 if (xpl->sadb_x_policy_type == IPSEC_POLICY_DISCARD 1418 || xpl->sadb_x_policy_type == IPSEC_POLICY_NONE) 1419 return EINVAL; 1420 1421 /* check privileged socket */ 1422 if (xpl->sadb_x_policy_type == IPSEC_POLICY_BYPASS) { 1423 error = kauth_authorize_network(cred, KAUTH_NETWORK_IPSEC, 1424 KAUTH_REQ_NETWORK_IPSEC_BYPASS, NULL, NULL, NULL); 1425 if (error) 1426 return (error); 1427 } 1428 1429 /* allocation new SP entry */ 1430 if ((newsp = key_msg2sp(xpl, len, &error)) == NULL) 1431 return error; 1432 1433 newsp->state = IPSEC_SPSTATE_ALIVE; 1434 1435 /* clear old SP and set new SP */ 1436 KEY_FREESP(policy); 1437 *policy = newsp; 1438 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DUMP)) { 1439 printf("%s: new policy\n", __func__); 1440 kdebug_secpolicy(newsp); 1441 } 1442 1443 return 0; 1444 } 1445 1446 static int 1447 ipsec_get_policy(struct secpolicy *policy, struct mbuf **mp) 1448 { 1449 1450 /* sanity check. */ 1451 if (policy == NULL || mp == NULL) 1452 return EINVAL; 1453 1454 *mp = key_sp2msg(policy); 1455 if (!*mp) { 1456 ipseclog((LOG_DEBUG, "%s: No more memory.\n", __func__)); 1457 return ENOBUFS; 1458 } 1459 1460 (*mp)->m_type = MT_DATA; 1461 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DUMP)) { 1462 printf("%s:\n", __func__); 1463 kdebug_mbuf(*mp); 1464 } 1465 1466 return 0; 1467 } 1468 1469 int 1470 ipsec4_set_policy(struct inpcb *inp, int optname, const void *request, 1471 size_t len, kauth_cred_t cred) 1472 { 1473 const struct sadb_x_policy *xpl; 1474 struct secpolicy **policy; 1475 1476 /* sanity check. */ 1477 if (inp == NULL || request == NULL) 1478 return EINVAL; 1479 if (len < sizeof(*xpl)) 1480 return EINVAL; 1481 xpl = (const struct sadb_x_policy *)request; 1482 1483 KASSERT(inp->inp_sp != NULL); 1484 1485 /* select direction */ 1486 switch (xpl->sadb_x_policy_dir) { 1487 case IPSEC_DIR_INBOUND: 1488 policy = &inp->inp_sp->sp_in; 1489 break; 1490 case IPSEC_DIR_OUTBOUND: 1491 policy = &inp->inp_sp->sp_out; 1492 break; 1493 default: 1494 ipseclog((LOG_ERR, "%s: invalid direction=%u\n", __func__, 1495 xpl->sadb_x_policy_dir)); 1496 return EINVAL; 1497 } 1498 1499 return ipsec_set_policy(policy, optname, request, len, cred); 1500 } 1501 1502 int 1503 ipsec4_get_policy(struct inpcb *inp, const void *request, size_t len, 1504 struct mbuf **mp) 1505 { 1506 const struct sadb_x_policy *xpl; 1507 struct secpolicy *policy; 1508 1509 /* sanity check. */ 1510 if (inp == NULL || request == NULL || mp == NULL) 1511 return EINVAL; 1512 KASSERT(inp->inp_sp != NULL); 1513 if (len < sizeof(*xpl)) 1514 return EINVAL; 1515 xpl = (const struct sadb_x_policy *)request; 1516 1517 /* select direction */ 1518 switch (xpl->sadb_x_policy_dir) { 1519 case IPSEC_DIR_INBOUND: 1520 policy = inp->inp_sp->sp_in; 1521 break; 1522 case IPSEC_DIR_OUTBOUND: 1523 policy = inp->inp_sp->sp_out; 1524 break; 1525 default: 1526 ipseclog((LOG_ERR, "%s: invalid direction=%u\n", __func__, 1527 xpl->sadb_x_policy_dir)); 1528 return EINVAL; 1529 } 1530 1531 return ipsec_get_policy(policy, mp); 1532 } 1533 1534 /* delete policy in PCB */ 1535 int 1536 ipsec4_delete_pcbpolicy(struct inpcb *inp) 1537 { 1538 1539 KASSERT(inp != NULL); 1540 1541 if (inp->inp_sp == NULL) 1542 return 0; 1543 1544 if (inp->inp_sp->sp_in != NULL) 1545 KEY_FREESP(&inp->inp_sp->sp_in); 1546 1547 if (inp->inp_sp->sp_out != NULL) 1548 KEY_FREESP(&inp->inp_sp->sp_out); 1549 1550 ipsec_invalpcbcache(inp->inp_sp, IPSEC_DIR_ANY); 1551 1552 ipsec_delpcbpolicy(inp->inp_sp); 1553 inp->inp_sp = NULL; 1554 1555 return 0; 1556 } 1557 1558 #ifdef INET6 1559 int 1560 ipsec6_set_policy(struct in6pcb *in6p, int optname, const void *request, 1561 size_t len, kauth_cred_t cred) 1562 { 1563 const struct sadb_x_policy *xpl; 1564 struct secpolicy **policy; 1565 1566 /* sanity check. */ 1567 if (in6p == NULL || request == NULL) 1568 return EINVAL; 1569 if (len < sizeof(*xpl)) 1570 return EINVAL; 1571 xpl = (const struct sadb_x_policy *)request; 1572 1573 /* select direction */ 1574 switch (xpl->sadb_x_policy_dir) { 1575 case IPSEC_DIR_INBOUND: 1576 policy = &in6p->in6p_sp->sp_in; 1577 break; 1578 case IPSEC_DIR_OUTBOUND: 1579 policy = &in6p->in6p_sp->sp_out; 1580 break; 1581 default: 1582 ipseclog((LOG_ERR, "%s: invalid direction=%u\n", __func__, 1583 xpl->sadb_x_policy_dir)); 1584 return EINVAL; 1585 } 1586 1587 return ipsec_set_policy(policy, optname, request, len, cred); 1588 } 1589 1590 int 1591 ipsec6_get_policy(struct in6pcb *in6p, const void *request, size_t len, 1592 struct mbuf **mp) 1593 { 1594 const struct sadb_x_policy *xpl; 1595 struct secpolicy *policy; 1596 1597 /* sanity check. */ 1598 if (in6p == NULL || request == NULL || mp == NULL) 1599 return EINVAL; 1600 KASSERT(in6p->in6p_sp != NULL); 1601 if (len < sizeof(*xpl)) 1602 return EINVAL; 1603 xpl = (const struct sadb_x_policy *)request; 1604 1605 /* select direction */ 1606 switch (xpl->sadb_x_policy_dir) { 1607 case IPSEC_DIR_INBOUND: 1608 policy = in6p->in6p_sp->sp_in; 1609 break; 1610 case IPSEC_DIR_OUTBOUND: 1611 policy = in6p->in6p_sp->sp_out; 1612 break; 1613 default: 1614 ipseclog((LOG_ERR, "%s: invalid direction=%u\n", __func__, 1615 xpl->sadb_x_policy_dir)); 1616 return EINVAL; 1617 } 1618 1619 return ipsec_get_policy(policy, mp); 1620 } 1621 1622 int 1623 ipsec6_delete_pcbpolicy(struct in6pcb *in6p) 1624 { 1625 1626 KASSERT(in6p != NULL); 1627 1628 if (in6p->in6p_sp == NULL) 1629 return 0; 1630 1631 if (in6p->in6p_sp->sp_in != NULL) 1632 KEY_FREESP(&in6p->in6p_sp->sp_in); 1633 1634 if (in6p->in6p_sp->sp_out != NULL) 1635 KEY_FREESP(&in6p->in6p_sp->sp_out); 1636 1637 ipsec_invalpcbcache(in6p->in6p_sp, IPSEC_DIR_ANY); 1638 1639 ipsec_delpcbpolicy(in6p->in6p_sp); 1640 in6p->in6p_sp = NULL; 1641 1642 return 0; 1643 } 1644 #endif 1645 1646 /* 1647 * return current level. 1648 * Either IPSEC_LEVEL_USE or IPSEC_LEVEL_REQUIRE are always returned. 1649 */ 1650 u_int 1651 ipsec_get_reqlevel(const struct ipsecrequest *isr) 1652 { 1653 u_int level = 0; 1654 u_int esp_trans_deflev, esp_net_deflev; 1655 u_int ah_trans_deflev, ah_net_deflev; 1656 1657 KASSERT(isr != NULL); 1658 KASSERT(isr->sp != NULL); 1659 KASSERTMSG( 1660 isr->sp->spidx.src.sa.sa_family == isr->sp->spidx.dst.sa.sa_family, 1661 "af family mismatch, src %u, dst %u", 1662 isr->sp->spidx.src.sa.sa_family, isr->sp->spidx.dst.sa.sa_family); 1663 1664 /* XXX note that we have ipseclog() expanded here - code sync issue */ 1665 #define IPSEC_CHECK_DEFAULT(lev) \ 1666 (((lev) != IPSEC_LEVEL_USE && (lev) != IPSEC_LEVEL_REQUIRE \ 1667 && (lev) != IPSEC_LEVEL_UNIQUE) ? \ 1668 (ipsec_debug ? log(LOG_INFO, "fixed system default level " #lev \ 1669 ":%d->%d\n", (lev), IPSEC_LEVEL_REQUIRE) : (void)0), \ 1670 (lev) = IPSEC_LEVEL_REQUIRE, (lev) \ 1671 : (lev)) 1672 1673 /* set default level */ 1674 switch (((struct sockaddr *)&isr->sp->spidx.src)->sa_family) { 1675 #ifdef INET 1676 case AF_INET: 1677 esp_trans_deflev = IPSEC_CHECK_DEFAULT(ip4_esp_trans_deflev); 1678 esp_net_deflev = IPSEC_CHECK_DEFAULT(ip4_esp_net_deflev); 1679 ah_trans_deflev = IPSEC_CHECK_DEFAULT(ip4_ah_trans_deflev); 1680 ah_net_deflev = IPSEC_CHECK_DEFAULT(ip4_ah_net_deflev); 1681 break; 1682 #endif 1683 #ifdef INET6 1684 case AF_INET6: 1685 esp_trans_deflev = IPSEC_CHECK_DEFAULT(ip6_esp_trans_deflev); 1686 esp_net_deflev = IPSEC_CHECK_DEFAULT(ip6_esp_net_deflev); 1687 ah_trans_deflev = IPSEC_CHECK_DEFAULT(ip6_ah_trans_deflev); 1688 ah_net_deflev = IPSEC_CHECK_DEFAULT(ip6_ah_net_deflev); 1689 break; 1690 #endif /* INET6 */ 1691 default: 1692 panic("%s: unknown af %u", __func__, 1693 isr->sp->spidx.src.sa.sa_family); 1694 } 1695 1696 #undef IPSEC_CHECK_DEFAULT 1697 1698 /* set level */ 1699 switch (isr->level) { 1700 case IPSEC_LEVEL_DEFAULT: 1701 switch (isr->saidx.proto) { 1702 case IPPROTO_ESP: 1703 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) 1704 level = esp_net_deflev; 1705 else 1706 level = esp_trans_deflev; 1707 break; 1708 case IPPROTO_AH: 1709 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) 1710 level = ah_net_deflev; 1711 else 1712 level = ah_trans_deflev; 1713 break; 1714 case IPPROTO_IPCOMP: 1715 /* 1716 * we don't really care, as IPcomp document says that 1717 * we shouldn't compress small packets 1718 */ 1719 level = IPSEC_LEVEL_USE; 1720 break; 1721 default: 1722 panic("%s: Illegal protocol defined %u", __func__, 1723 isr->saidx.proto); 1724 } 1725 break; 1726 1727 case IPSEC_LEVEL_USE: 1728 case IPSEC_LEVEL_REQUIRE: 1729 level = isr->level; 1730 break; 1731 case IPSEC_LEVEL_UNIQUE: 1732 level = IPSEC_LEVEL_REQUIRE; 1733 break; 1734 1735 default: 1736 panic("%s: Illegal IPsec level %u", __func__, isr->level); 1737 } 1738 1739 return level; 1740 } 1741 1742 /* 1743 * Check security policy requirements against the actual 1744 * packet contents. Return one if the packet should be 1745 * reject as "invalid"; otherwiser return zero to have the 1746 * packet treated as "valid". 1747 * 1748 * OUT: 1749 * 0: valid 1750 * 1: invalid 1751 */ 1752 int 1753 ipsec_in_reject(const struct secpolicy *sp, const struct mbuf *m) 1754 { 1755 struct ipsecrequest *isr; 1756 int need_auth; 1757 1758 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DATA)) { 1759 printf("%s: using SP\n", __func__); 1760 kdebug_secpolicy(sp); 1761 } 1762 1763 /* check policy */ 1764 switch (sp->policy) { 1765 case IPSEC_POLICY_DISCARD: 1766 return 1; 1767 case IPSEC_POLICY_BYPASS: 1768 case IPSEC_POLICY_NONE: 1769 return 0; 1770 } 1771 1772 KASSERTMSG(sp->policy == IPSEC_POLICY_IPSEC, 1773 "invalid policy %u", sp->policy); 1774 1775 /* XXX should compare policy against ipsec header history */ 1776 1777 need_auth = 0; 1778 for (isr = sp->req; isr != NULL; isr = isr->next) { 1779 if (ipsec_get_reqlevel(isr) != IPSEC_LEVEL_REQUIRE) 1780 continue; 1781 switch (isr->saidx.proto) { 1782 case IPPROTO_ESP: 1783 if ((m->m_flags & M_DECRYPTED) == 0) { 1784 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 1785 "ESP m_flags:%x\n", m->m_flags); 1786 return 1; 1787 } 1788 1789 if (!need_auth && 1790 isr->sav != NULL && 1791 isr->sav->tdb_authalgxform != NULL && 1792 (m->m_flags & M_AUTHIPDGM) == 0) { 1793 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 1794 "ESP/AH m_flags:%x\n", m->m_flags); 1795 return 1; 1796 } 1797 break; 1798 case IPPROTO_AH: 1799 need_auth = 1; 1800 if ((m->m_flags & M_AUTHIPHDR) == 0) { 1801 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 1802 "AH m_flags:%x\n", m->m_flags); 1803 return 1; 1804 } 1805 break; 1806 case IPPROTO_IPCOMP: 1807 /* 1808 * we don't really care, as IPcomp document 1809 * says that we shouldn't compress small 1810 * packets, IPComp policy should always be 1811 * treated as being in "use" level. 1812 */ 1813 break; 1814 } 1815 } 1816 return 0; /* valid */ 1817 } 1818 1819 /* 1820 * Check AH/ESP integrity. 1821 * This function is called from tcp_input(), udp_input(), 1822 * and {ah,esp}4_input for tunnel mode 1823 */ 1824 int 1825 ipsec4_in_reject(struct mbuf *m, struct inpcb *inp) 1826 { 1827 struct secpolicy *sp; 1828 int error; 1829 int result; 1830 1831 KASSERT(m != NULL); 1832 1833 /* get SP for this packet. 1834 * When we are called from ip_forward(), we call 1835 * ipsec_getpolicybyaddr() with IP_FORWARDING flag. 1836 */ 1837 if (inp == NULL) 1838 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND, IP_FORWARDING, &error); 1839 else 1840 sp = ipsec_getpolicybysock(m, IPSEC_DIR_INBOUND, 1841 (struct inpcb_hdr *)inp, &error); 1842 1843 if (sp != NULL) { 1844 result = ipsec_in_reject(sp, m); 1845 if (result) 1846 IPSEC_STATINC(IPSEC_STAT_IN_POLVIO); 1847 KEY_FREESP(&sp); 1848 } else { 1849 result = 0; /* XXX should be panic ? 1850 * -> No, there may be error. */ 1851 } 1852 return result; 1853 } 1854 1855 1856 #ifdef INET6 1857 /* 1858 * Check AH/ESP integrity. 1859 * This function is called from tcp6_input(), udp6_input(), 1860 * and {ah,esp}6_input for tunnel mode 1861 */ 1862 int 1863 ipsec6_in_reject(struct mbuf *m, struct in6pcb *in6p) 1864 { 1865 struct secpolicy *sp = NULL; 1866 int error; 1867 int result; 1868 1869 KASSERT(m != NULL); 1870 1871 /* get SP for this packet. 1872 * When we are called from ip_forward(), we call 1873 * ipsec_getpolicybyaddr() with IP_FORWARDING flag. 1874 */ 1875 if (in6p == NULL) 1876 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND, IP_FORWARDING, &error); 1877 else 1878 sp = ipsec_getpolicybysock(m, IPSEC_DIR_INBOUND, 1879 (struct inpcb_hdr *)in6p, 1880 &error); 1881 1882 if (sp != NULL) { 1883 result = ipsec_in_reject(sp, m); 1884 if (result) 1885 IPSEC_STATINC(IPSEC_STAT_IN_POLVIO); 1886 KEY_FREESP(&sp); 1887 } else { 1888 result = 0; 1889 } 1890 return result; 1891 } 1892 #endif 1893 1894 /* 1895 * compute the byte size to be occupied by IPsec header. 1896 * in case it is tunneled, it includes the size of outer IP header. 1897 * NOTE: SP passed is free in this function. 1898 */ 1899 static size_t 1900 ipsec_hdrsiz(const struct secpolicy *sp) 1901 { 1902 const struct ipsecrequest *isr; 1903 size_t siz; 1904 1905 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DATA)) { 1906 printf("%s: using SP\n", __func__); 1907 kdebug_secpolicy(sp); 1908 } 1909 1910 switch (sp->policy) { 1911 case IPSEC_POLICY_DISCARD: 1912 case IPSEC_POLICY_BYPASS: 1913 case IPSEC_POLICY_NONE: 1914 return 0; 1915 } 1916 1917 KASSERTMSG(sp->policy == IPSEC_POLICY_IPSEC, 1918 "invalid policy %u", sp->policy); 1919 1920 siz = 0; 1921 for (isr = sp->req; isr != NULL; isr = isr->next) { 1922 size_t clen = 0; 1923 1924 switch (isr->saidx.proto) { 1925 case IPPROTO_ESP: 1926 clen = esp_hdrsiz(isr->sav); 1927 break; 1928 case IPPROTO_AH: 1929 clen = ah_hdrsiz(isr->sav); 1930 break; 1931 case IPPROTO_IPCOMP: 1932 clen = sizeof(struct ipcomp); 1933 break; 1934 } 1935 1936 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) { 1937 switch (isr->saidx.dst.sa.sa_family) { 1938 case AF_INET: 1939 clen += sizeof(struct ip); 1940 break; 1941 #ifdef INET6 1942 case AF_INET6: 1943 clen += sizeof(struct ip6_hdr); 1944 break; 1945 #endif 1946 default: 1947 ipseclog((LOG_ERR, "%s: unknown AF %d in " 1948 "IPsec tunnel SA\n", __func__, 1949 ((const struct sockaddr *)&isr->saidx.dst) 1950 ->sa_family)); 1951 break; 1952 } 1953 } 1954 siz += clen; 1955 } 1956 1957 return siz; 1958 } 1959 1960 /* This function is called from ip_forward() and ipsec4_hdrsize_tcp(). */ 1961 size_t 1962 ipsec4_hdrsiz(struct mbuf *m, u_int dir, struct inpcb *inp) 1963 { 1964 struct secpolicy *sp; 1965 int error; 1966 size_t size; 1967 1968 KASSERT(m != NULL); 1969 KASSERTMSG(inp == NULL || inp->inp_socket != NULL, "socket w/o inpcb"); 1970 1971 /* get SP for this packet. 1972 * When we are called from ip_forward(), we call 1973 * ipsec_getpolicybyaddr() with IP_FORWARDING flag. 1974 */ 1975 if (inp == NULL) 1976 sp = ipsec_getpolicybyaddr(m, dir, IP_FORWARDING, &error); 1977 else 1978 sp = ipsec_getpolicybysock(m, dir, 1979 (struct inpcb_hdr *)inp, &error); 1980 1981 if (sp != NULL) { 1982 size = ipsec_hdrsiz(sp); 1983 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DATA, "size:%lu.\n", 1984 (unsigned long)size); 1985 1986 KEY_FREESP(&sp); 1987 } else { 1988 size = 0; /* XXX should be panic ? */ 1989 } 1990 return size; 1991 } 1992 1993 #ifdef INET6 1994 /* This function is called from ipsec6_hdrsize_tcp(), 1995 * and maybe from ip6_forward.() 1996 */ 1997 size_t 1998 ipsec6_hdrsiz(struct mbuf *m, u_int dir, struct in6pcb *in6p) 1999 { 2000 struct secpolicy *sp; 2001 int error; 2002 size_t size; 2003 2004 KASSERT(m != NULL); 2005 KASSERTMSG(in6p == NULL || in6p->in6p_socket != NULL, 2006 "socket w/o inpcb"); 2007 2008 /* get SP for this packet */ 2009 /* XXX Is it right to call with IP_FORWARDING. */ 2010 if (in6p == NULL) 2011 sp = ipsec_getpolicybyaddr(m, dir, IP_FORWARDING, &error); 2012 else 2013 sp = ipsec_getpolicybysock(m, dir, 2014 (struct inpcb_hdr *)in6p, 2015 &error); 2016 2017 if (sp == NULL) 2018 return 0; 2019 size = ipsec_hdrsiz(sp); 2020 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DATA, "size:%zu.\n", size); 2021 KEY_FREESP(&sp); 2022 2023 return size; 2024 } 2025 #endif /*INET6*/ 2026 2027 /* 2028 * Check the variable replay window. 2029 * ipsec_chkreplay() performs replay check before ICV verification. 2030 * ipsec_updatereplay() updates replay bitmap. This must be called after 2031 * ICV verification (it also performs replay check, which is usually done 2032 * beforehand). 2033 * 0 (zero) is returned if packet disallowed, 1 if packet permitted. 2034 * 2035 * based on RFC 2401. 2036 */ 2037 int 2038 ipsec_chkreplay(u_int32_t seq, const struct secasvar *sav) 2039 { 2040 const struct secreplay *replay; 2041 u_int32_t diff; 2042 int fr; 2043 u_int32_t wsizeb; /* constant: bits of window size */ 2044 int frlast; /* constant: last frame */ 2045 2046 IPSEC_SPLASSERT_SOFTNET(__func__); 2047 2048 KASSERT(sav != NULL); 2049 KASSERT(sav->replay != NULL); 2050 2051 replay = sav->replay; 2052 2053 if (replay->wsize == 0) 2054 return 1; /* no need to check replay. */ 2055 2056 /* constant */ 2057 frlast = replay->wsize - 1; 2058 wsizeb = replay->wsize << 3; 2059 2060 /* sequence number of 0 is invalid */ 2061 if (seq == 0) 2062 return 0; 2063 2064 /* first time is always okay */ 2065 if (replay->count == 0) 2066 return 1; 2067 2068 if (seq > replay->lastseq) { 2069 /* larger sequences are okay */ 2070 return 1; 2071 } else { 2072 /* seq is equal or less than lastseq. */ 2073 diff = replay->lastseq - seq; 2074 2075 /* over range to check, i.e. too old or wrapped */ 2076 if (diff >= wsizeb) 2077 return 0; 2078 2079 fr = frlast - diff / 8; 2080 2081 /* this packet already seen ? */ 2082 if ((replay->bitmap)[fr] & (1 << (diff % 8))) 2083 return 0; 2084 2085 /* out of order but good */ 2086 return 1; 2087 } 2088 } 2089 2090 /* 2091 * check replay counter whether to update or not. 2092 * OUT: 0: OK 2093 * 1: NG 2094 */ 2095 int 2096 ipsec_updatereplay(u_int32_t seq, const struct secasvar *sav) 2097 { 2098 struct secreplay *replay; 2099 u_int32_t diff; 2100 int fr; 2101 u_int32_t wsizeb; /* constant: bits of window size */ 2102 int frlast; /* constant: last frame */ 2103 2104 IPSEC_SPLASSERT_SOFTNET(__func__); 2105 2106 KASSERT(sav != NULL); 2107 KASSERT(sav->replay != NULL); 2108 2109 replay = sav->replay; 2110 2111 if (replay->wsize == 0) 2112 goto ok; /* no need to check replay. */ 2113 2114 /* constant */ 2115 frlast = replay->wsize - 1; 2116 wsizeb = replay->wsize << 3; 2117 2118 /* sequence number of 0 is invalid */ 2119 if (seq == 0) 2120 return 1; 2121 2122 /* first time */ 2123 if (replay->count == 0) { 2124 replay->lastseq = seq; 2125 memset(replay->bitmap, 0, replay->wsize); 2126 (replay->bitmap)[frlast] = 1; 2127 goto ok; 2128 } 2129 2130 if (seq > replay->lastseq) { 2131 /* seq is larger than lastseq. */ 2132 diff = seq - replay->lastseq; 2133 2134 /* new larger sequence number */ 2135 if (diff < wsizeb) { 2136 /* In window */ 2137 /* set bit for this packet */ 2138 vshiftl(replay->bitmap, diff, replay->wsize); 2139 (replay->bitmap)[frlast] |= 1; 2140 } else { 2141 /* this packet has a "way larger" */ 2142 memset(replay->bitmap, 0, replay->wsize); 2143 (replay->bitmap)[frlast] = 1; 2144 } 2145 replay->lastseq = seq; 2146 2147 /* larger is good */ 2148 } else { 2149 /* seq is equal or less than lastseq. */ 2150 diff = replay->lastseq - seq; 2151 2152 /* over range to check, i.e. too old or wrapped */ 2153 if (diff >= wsizeb) 2154 return 1; 2155 2156 fr = frlast - diff / 8; 2157 2158 /* this packet already seen ? */ 2159 if ((replay->bitmap)[fr] & (1 << (diff % 8))) 2160 return 1; 2161 2162 /* mark as seen */ 2163 (replay->bitmap)[fr] |= (1 << (diff % 8)); 2164 2165 /* out of order but good */ 2166 } 2167 2168 ok: 2169 if (replay->count == ~0) { 2170 2171 /* set overflow flag */ 2172 replay->overflow++; 2173 2174 /* don't increment, no more packets accepted */ 2175 if ((sav->flags & SADB_X_EXT_CYCSEQ) == 0) 2176 return 1; 2177 2178 ipseclog((LOG_WARNING, "replay counter made %d cycle. %s\n", 2179 replay->overflow, ipsec_logsastr(sav))); 2180 } 2181 2182 replay->count++; 2183 2184 return 0; 2185 } 2186 2187 /* 2188 * shift variable length bunffer to left. 2189 * IN: bitmap: pointer to the buffer 2190 * nbit: the number of to shift. 2191 * wsize: buffer size (bytes). 2192 */ 2193 static void 2194 vshiftl(unsigned char *bitmap, int nbit, int wsize) 2195 { 2196 int s, j, i; 2197 unsigned char over; 2198 2199 for (j = 0; j < nbit; j += 8) { 2200 s = (nbit - j < 8) ? (nbit - j): 8; 2201 bitmap[0] <<= s; 2202 for (i = 1; i < wsize; i++) { 2203 over = (bitmap[i] >> (8 - s)); 2204 bitmap[i] <<= s; 2205 bitmap[i-1] |= over; 2206 } 2207 } 2208 2209 return; 2210 } 2211 2212 /* Return a printable string for the IPv4 address. */ 2213 static char * 2214 inet_ntoa4(struct in_addr ina) 2215 { 2216 static char buf[4][4 * sizeof "123" + 4]; 2217 unsigned char *ucp = (unsigned char *) &ina; 2218 static int i = 3; 2219 2220 i = (i + 1) % 4; 2221 snprintf(buf[i], sizeof(buf[i]), "%d.%d.%d.%d", 2222 ucp[0] & 0xff, ucp[1] & 0xff, ucp[2] & 0xff, ucp[3] & 0xff); 2223 return (buf[i]); 2224 } 2225 2226 /* Return a printable string for the address. */ 2227 const char * 2228 ipsec_address(const union sockaddr_union *sa) 2229 { 2230 #if INET6 2231 static char ip6buf[INET6_ADDRSTRLEN]; /* XXX: NOMPSAFE */ 2232 #endif 2233 2234 switch (sa->sa.sa_family) { 2235 #if INET 2236 case AF_INET: 2237 return inet_ntoa4(sa->sin.sin_addr); 2238 #endif /* INET */ 2239 2240 #if INET6 2241 case AF_INET6: 2242 return IN6_PRINT(ip6buf, &sa->sin6.sin6_addr); 2243 #endif /* INET6 */ 2244 2245 default: 2246 return "(unknown address family)"; 2247 } 2248 } 2249 2250 const char * 2251 ipsec_logsastr(const struct secasvar *sav) 2252 { 2253 static char buf[256]; 2254 char *p; 2255 const struct secasindex *saidx = &sav->sah->saidx; 2256 2257 KASSERTMSG(saidx->src.sa.sa_family == saidx->dst.sa.sa_family, 2258 "af family mismatch, src %u, dst %u", 2259 saidx->src.sa.sa_family, saidx->dst.sa.sa_family); 2260 2261 p = buf; 2262 snprintf(buf, sizeof(buf), "SA(SPI=%u ", (u_int32_t)ntohl(sav->spi)); 2263 while (p && *p) 2264 p++; 2265 /* NB: only use ipsec_address on one address at a time */ 2266 snprintf(p, sizeof (buf) - (p - buf), "src=%s ", 2267 ipsec_address(&saidx->src)); 2268 while (p && *p) 2269 p++; 2270 snprintf(p, sizeof (buf) - (p - buf), "dst=%s)", 2271 ipsec_address(&saidx->dst)); 2272 2273 return buf; 2274 } 2275 2276 void 2277 ipsec_dumpmbuf(struct mbuf *m) 2278 { 2279 int totlen; 2280 int i; 2281 u_char *p; 2282 2283 totlen = 0; 2284 printf("---\n"); 2285 while (m) { 2286 p = mtod(m, u_char *); 2287 for (i = 0; i < m->m_len; i++) { 2288 printf("%02x ", p[i]); 2289 totlen++; 2290 if (totlen % 16 == 0) 2291 printf("\n"); 2292 } 2293 m = m->m_next; 2294 } 2295 if (totlen % 16 != 0) 2296 printf("\n"); 2297 printf("---\n"); 2298 } 2299 2300 #ifdef INET6 2301 struct secpolicy * 2302 ipsec6_check_policy(struct mbuf *m, struct in6pcb *in6p, 2303 int flags, int *needipsecp, int *errorp) 2304 { 2305 struct secpolicy *sp = NULL; 2306 int s; 2307 int error = 0; 2308 int needipsec = 0; 2309 2310 if (!ipsec_outdone(m)) { 2311 s = splsoftnet(); 2312 if (in6p != NULL && 2313 IPSEC_PCB_SKIP_IPSEC(in6p->in6p_sp, IPSEC_DIR_OUTBOUND)) { 2314 splx(s); 2315 goto skippolicycheck; 2316 } 2317 sp = ipsec6_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags, &error,in6p); 2318 2319 /* 2320 * There are four return cases: 2321 * sp != NULL apply IPsec policy 2322 * sp == NULL, error == 0 no IPsec handling needed 2323 * sp == NULL, error == -EINVAL discard packet w/o error 2324 * sp == NULL, error != 0 discard packet, report error 2325 */ 2326 2327 splx(s); 2328 if (sp == NULL) { 2329 /* 2330 * Caller must check the error return to see if it needs to discard 2331 * the packet. 2332 */ 2333 needipsec = 0; 2334 } else { 2335 needipsec = 1; 2336 } 2337 } 2338 skippolicycheck:; 2339 2340 *errorp = error; 2341 *needipsecp = needipsec; 2342 return sp; 2343 } 2344 2345 int 2346 ipsec6_input(struct mbuf *m) 2347 { 2348 struct m_tag *mtag; 2349 struct tdb_ident *tdbi; 2350 struct secpolicy *sp; 2351 int s, error; 2352 2353 /* 2354 * Check if the packet has already had IPsec 2355 * processing done. If so, then just pass it 2356 * along. This tag gets set during AH, ESP, 2357 * etc. input handling, before the packet is 2358 * returned to the ip input queue for delivery. 2359 */ 2360 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, 2361 NULL); 2362 s = splsoftnet(); 2363 if (mtag != NULL) { 2364 tdbi = (struct tdb_ident *)(mtag + 1); 2365 sp = ipsec_getpolicy(tdbi, 2366 IPSEC_DIR_INBOUND); 2367 } else { 2368 sp = ipsec_getpolicybyaddr(m, 2369 IPSEC_DIR_INBOUND, IP_FORWARDING, 2370 &error); 2371 } 2372 if (sp != NULL) { 2373 /* 2374 * Check security policy against packet 2375 * attributes. 2376 */ 2377 error = ipsec_in_reject(sp, m); 2378 KEY_FREESP(&sp); 2379 } else { 2380 /* XXX error stat??? */ 2381 error = EINVAL; 2382 DPRINTF(("ip6_input: no SP, packet" 2383 " discarded\n"));/*XXX*/ 2384 } 2385 splx(s); 2386 2387 return error; 2388 } 2389 #endif /* INET6 */ 2390 2391 2392 2393 /* XXX this stuff doesn't belong here... */ 2394 2395 static struct xformsw *xforms = NULL; 2396 2397 /* 2398 * Register a transform; typically at system startup. 2399 */ 2400 void 2401 xform_register(struct xformsw *xsp) 2402 { 2403 xsp->xf_next = xforms; 2404 xforms = xsp; 2405 } 2406 2407 /* 2408 * Initialize transform support in an sav. 2409 */ 2410 int 2411 xform_init(struct secasvar *sav, int xftype) 2412 { 2413 struct xformsw *xsp; 2414 2415 if (sav->tdb_xform != NULL) /* previously initialized */ 2416 return 0; 2417 for (xsp = xforms; xsp; xsp = xsp->xf_next) 2418 if (xsp->xf_type == xftype) 2419 return (*xsp->xf_init)(sav, xsp); 2420 2421 DPRINTF(("%s: no match for xform type %d\n", __func__, xftype)); 2422 return EINVAL; 2423 } 2424 2425 void 2426 nat_t_ports_get(struct mbuf *m, u_int16_t *dport, u_int16_t *sport) { 2427 struct m_tag *tag; 2428 2429 if ((tag = m_tag_find(m, PACKET_TAG_IPSEC_NAT_T_PORTS, NULL))) { 2430 *sport = ((u_int16_t *)(tag + 1))[0]; 2431 *dport = ((u_int16_t *)(tag + 1))[1]; 2432 } else 2433 *sport = *dport = 0; 2434 } 2435 2436 /* 2437 * XXXJRT This should be done as a protosw init call. 2438 */ 2439 void 2440 ipsec_attach(void) 2441 { 2442 2443 ipsecstat_percpu = percpu_alloc(sizeof(uint64_t) * IPSEC_NSTATS); 2444 2445 sysctl_net_inet_ipsec_setup(NULL); 2446 #ifdef INET6 2447 sysctl_net_inet6_ipsec6_setup(NULL); 2448 #endif 2449 2450 ah_attach(); 2451 esp_attach(); 2452 ipcomp_attach(); 2453 ipe4_attach(); 2454 #ifdef TCP_SIGNATURE 2455 tcpsignature_attach(); 2456 #endif 2457 } 2458
Indexes created Sun Sep 21 20:09:37 GMT 2025