ipsec.c revision 1.87
1 /* $NetBSD: ipsec.c,v 1.87 2017/05/10 09:34:52 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 1.87 2017/05/10 09:34:52 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 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 } 710 711 /* 712 * NAT-T ESP fragmentation: do not do IPSec processing now, 713 * we will do it on each fragmented packet. 714 */ 715 if (sp->req->sav && (sp->req->sav->natt_type & 716 (UDP_ENCAP_ESPINUDP|UDP_ENCAP_ESPINUDP_NON_IKE))) { 717 if (ntohs(ip->ip_len) > sp->req->sav->esp_frag) { 718 *mtu = sp->req->sav->esp_frag; 719 *natt_frag = true; 720 KEY_FREESP(&sp); 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); 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 KEY_FREESP(&sp); 747 splx(s); 748 *done = true; 749 return error; 750 } 751 752 int 753 ipsec4_input(struct mbuf *m, int flags) 754 { 755 struct m_tag *mtag; 756 struct tdb_ident *tdbi; 757 struct secpolicy *sp; 758 int error, s; 759 760 /* 761 * Check if the packet has already had IPsec processing done. 762 * If so, then just pass it along. This tag gets set during AH, 763 * ESP, etc. input handling, before the packet is returned to 764 * the IP input queue for delivery. 765 */ 766 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL); 767 s = splsoftnet(); 768 if (mtag != NULL) { 769 tdbi = (struct tdb_ident *)(mtag + 1); 770 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND); 771 } else { 772 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND, 773 IP_FORWARDING, &error); 774 } 775 if (sp == NULL) { 776 splx(s); 777 return EINVAL; 778 } 779 780 /* 781 * Check security policy against packet attributes. 782 */ 783 error = ipsec_in_reject(sp, m); 784 KEY_FREESP(&sp); 785 splx(s); 786 if (error) { 787 return error; 788 } 789 790 if (flags == 0) { 791 /* We are done. */ 792 return 0; 793 } 794 795 /* 796 * Peek at the outbound SP for this packet to determine if 797 * it is a Fast Forward candidate. 798 */ 799 mtag = m_tag_find(m, PACKET_TAG_IPSEC_PENDING_TDB, NULL); 800 if (mtag != NULL) { 801 m->m_flags &= ~M_CANFASTFWD; 802 return 0; 803 } 804 805 s = splsoftnet(); 806 sp = ipsec4_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags, &error, NULL); 807 if (sp != NULL) { 808 m->m_flags &= ~M_CANFASTFWD; 809 KEY_FREESP(&sp); 810 } 811 splx(s); 812 return 0; 813 } 814 815 int 816 ipsec4_forward(struct mbuf *m, int *destmtu) 817 { 818 /* 819 * If the packet is routed over IPsec tunnel, tell the 820 * originator the tunnel MTU. 821 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz 822 * XXX quickhack!!! 823 */ 824 struct secpolicy *sp; 825 size_t ipsechdr; 826 int error; 827 828 sp = ipsec4_getpolicybyaddr(m, 829 IPSEC_DIR_OUTBOUND, IP_FORWARDING, &error); 830 if (sp == NULL) { 831 return EINVAL; 832 } 833 834 /* Count IPsec header size. */ 835 ipsechdr = ipsec4_hdrsiz(m, IPSEC_DIR_OUTBOUND, NULL); 836 837 /* 838 * Find the correct route for outer IPv4 header, compute tunnel MTU. 839 */ 840 if (sp->req && sp->req->sav && sp->req->sav->sah) { 841 struct route *ro; 842 struct rtentry *rt; 843 844 ro = &sp->req->sav->sah->sa_route; 845 rt = rtcache_validate(ro); 846 if (rt && rt->rt_ifp) { 847 *destmtu = rt->rt_rmx.rmx_mtu ? 848 rt->rt_rmx.rmx_mtu : rt->rt_ifp->if_mtu; 849 *destmtu -= ipsechdr; 850 } 851 rtcache_unref(rt, ro); 852 } 853 KEY_FREESP(&sp); 854 return 0; 855 } 856 857 #ifdef INET6 858 struct secpolicy * 859 ipsec6_checkpolicy(struct mbuf *m, u_int dir, u_int flag, int *error, 860 struct in6pcb *in6p) 861 { 862 struct secpolicy *sp; 863 864 *error = 0; 865 866 if (in6p == NULL) { 867 sp = ipsec_getpolicybyaddr(m, dir, flag, error); 868 } else { 869 KASSERT(in6p->in6p_socket != NULL); 870 sp = ipsec_getpolicybysock(m, dir, (struct inpcb_hdr *)in6p, error); 871 } 872 if (sp == NULL) { 873 KASSERTMSG(*error != 0, "getpolicy failed w/o error"); 874 IPSEC_STATINC(IPSEC_STAT_OUT_INVAL); 875 return NULL; 876 } 877 KASSERTMSG(*error == 0, "sp w/ error set to %u", *error); 878 switch (sp->policy) { 879 case IPSEC_POLICY_ENTRUST: 880 default: 881 printf("%s: invalid policy %u\n", __func__, sp->policy); 882 /* fall thru... */ 883 case IPSEC_POLICY_DISCARD: 884 IPSEC_STATINC(IPSEC_STAT_OUT_POLVIO); 885 *error = -EINVAL; /* packet is discarded by caller */ 886 break; 887 case IPSEC_POLICY_BYPASS: 888 case IPSEC_POLICY_NONE: 889 KEY_FREESP(&sp); 890 sp = NULL; /* NB: force NULL result */ 891 break; 892 case IPSEC_POLICY_IPSEC: 893 if (sp->req == NULL) /* acquire an SA */ 894 *error = key_spdacquire(sp); 895 break; 896 } 897 if (*error != 0) { 898 KEY_FREESP(&sp); 899 sp = NULL; 900 DPRINTF(("%s: done, error %d\n", __func__, *error)); 901 } 902 return sp; 903 } 904 #endif /* INET6 */ 905 906 static int 907 ipsec4_setspidx_inpcb(struct mbuf *m, struct inpcb *pcb) 908 { 909 int error; 910 911 KASSERT(pcb != NULL); 912 KASSERT(pcb->inp_sp != NULL); 913 KASSERT(pcb->inp_sp->sp_out != NULL); 914 KASSERT(pcb->inp_sp->sp_in != NULL); 915 916 error = ipsec_setspidx(m, &pcb->inp_sp->sp_in->spidx, 1); 917 if (error == 0) { 918 pcb->inp_sp->sp_in->spidx.dir = IPSEC_DIR_INBOUND; 919 pcb->inp_sp->sp_out->spidx = pcb->inp_sp->sp_in->spidx; 920 pcb->inp_sp->sp_out->spidx.dir = IPSEC_DIR_OUTBOUND; 921 } else { 922 memset(&pcb->inp_sp->sp_in->spidx, 0, 923 sizeof (pcb->inp_sp->sp_in->spidx)); 924 memset(&pcb->inp_sp->sp_out->spidx, 0, 925 sizeof (pcb->inp_sp->sp_in->spidx)); 926 } 927 return error; 928 } 929 930 #ifdef INET6 931 static int 932 ipsec6_setspidx_in6pcb(struct mbuf *m, struct in6pcb *pcb) 933 { 934 struct secpolicyindex *spidx; 935 int error; 936 937 KASSERT(pcb != NULL); 938 KASSERT(pcb->in6p_sp != NULL); 939 KASSERT(pcb->in6p_sp->sp_out != NULL); 940 KASSERT(pcb->in6p_sp->sp_in != NULL); 941 942 memset(&pcb->in6p_sp->sp_in->spidx, 0, sizeof(*spidx)); 943 memset(&pcb->in6p_sp->sp_out->spidx, 0, sizeof(*spidx)); 944 945 spidx = &pcb->in6p_sp->sp_in->spidx; 946 error = ipsec_setspidx(m, spidx, 1); 947 if (error) 948 goto bad; 949 spidx->dir = IPSEC_DIR_INBOUND; 950 951 spidx = &pcb->in6p_sp->sp_out->spidx; 952 error = ipsec_setspidx(m, spidx, 1); 953 if (error) 954 goto bad; 955 spidx->dir = IPSEC_DIR_OUTBOUND; 956 957 return 0; 958 959 bad: 960 memset(&pcb->in6p_sp->sp_in->spidx, 0, sizeof(*spidx)); 961 memset(&pcb->in6p_sp->sp_out->spidx, 0, sizeof(*spidx)); 962 return error; 963 } 964 #endif 965 966 /* 967 * configure security policy index (src/dst/proto/sport/dport) 968 * by looking at the content of mbuf. 969 * the caller is responsible for error recovery (like clearing up spidx). 970 */ 971 static int 972 ipsec_setspidx(struct mbuf *m, struct secpolicyindex *spidx, int needport) 973 { 974 struct ip *ip = NULL; 975 struct ip ipbuf; 976 u_int v; 977 struct mbuf *n; 978 int len; 979 int error; 980 981 KASSERT(m != NULL); 982 983 /* 984 * validate m->m_pkthdr.len. we see incorrect length if we 985 * mistakenly call this function with inconsistent mbuf chain 986 * (like 4.4BSD tcp/udp processing). XXX should we panic here? 987 */ 988 len = 0; 989 for (n = m; n; n = n->m_next) 990 len += n->m_len; 991 if (m->m_pkthdr.len != len) { 992 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 993 "total of m_len(%d) != pkthdr.len(%d), ignored.\n", 994 len, m->m_pkthdr.len); 995 return EINVAL; 996 } 997 998 if (m->m_pkthdr.len < sizeof(struct ip)) { 999 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 1000 "pkthdr.len(%d) < sizeof(struct ip), ignored.\n", 1001 m->m_pkthdr.len); 1002 return EINVAL; 1003 } 1004 1005 if (m->m_len >= sizeof(*ip)) 1006 ip = mtod(m, struct ip *); 1007 else { 1008 m_copydata(m, 0, sizeof(ipbuf), &ipbuf); 1009 ip = &ipbuf; 1010 } 1011 v = ip->ip_v; 1012 switch (v) { 1013 case 4: 1014 error = ipsec4_setspidx_ipaddr(m, spidx); 1015 if (error) 1016 return error; 1017 ipsec4_get_ulp(m, spidx, needport); 1018 return 0; 1019 #ifdef INET6 1020 case 6: 1021 if (m->m_pkthdr.len < sizeof(struct ip6_hdr)) { 1022 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 1023 "pkthdr.len(%d) < sizeof(struct ip6_hdr), " 1024 "ignored.\n", m->m_pkthdr.len); 1025 return EINVAL; 1026 } 1027 error = ipsec6_setspidx_ipaddr(m, spidx); 1028 if (error) 1029 return error; 1030 ipsec6_get_ulp(m, spidx, needport); 1031 return 0; 1032 #endif 1033 default: 1034 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 1035 "unknown IP version %u, ignored.\n", v); 1036 return EINVAL; 1037 } 1038 } 1039 1040 static void 1041 ipsec4_get_ulp(struct mbuf *m, struct secpolicyindex *spidx, int needport) 1042 { 1043 u_int8_t nxt; 1044 int off; 1045 1046 /* sanity check */ 1047 KASSERT(m != NULL); 1048 KASSERTMSG(m->m_pkthdr.len >= sizeof(struct ip), "packet too short"); 1049 1050 /* NB: ip_input() flips it into host endian XXX need more checking */ 1051 if (m->m_len >= sizeof(struct ip)) { 1052 struct ip *ip = mtod(m, struct ip *); 1053 if (ip->ip_off & htons(IP_MF | IP_OFFMASK)) 1054 goto done; 1055 off = ip->ip_hl << 2; 1056 nxt = ip->ip_p; 1057 } else { 1058 struct ip ih; 1059 1060 m_copydata(m, 0, sizeof (struct ip), &ih); 1061 if (ih.ip_off & htons(IP_MF | IP_OFFMASK)) 1062 goto done; 1063 off = ih.ip_hl << 2; 1064 nxt = ih.ip_p; 1065 } 1066 1067 while (off < m->m_pkthdr.len) { 1068 struct ip6_ext ip6e; 1069 struct tcphdr th; 1070 struct udphdr uh; 1071 struct icmp icmph; 1072 1073 switch (nxt) { 1074 case IPPROTO_TCP: 1075 spidx->ul_proto = nxt; 1076 if (!needport) 1077 goto done_proto; 1078 if (off + sizeof(struct tcphdr) > m->m_pkthdr.len) 1079 goto done; 1080 m_copydata(m, off, sizeof (th), &th); 1081 spidx->src.sin.sin_port = th.th_sport; 1082 spidx->dst.sin.sin_port = th.th_dport; 1083 return; 1084 case IPPROTO_UDP: 1085 spidx->ul_proto = nxt; 1086 if (!needport) 1087 goto done_proto; 1088 if (off + sizeof(struct udphdr) > m->m_pkthdr.len) 1089 goto done; 1090 m_copydata(m, off, sizeof (uh), &uh); 1091 spidx->src.sin.sin_port = uh.uh_sport; 1092 spidx->dst.sin.sin_port = uh.uh_dport; 1093 return; 1094 case IPPROTO_AH: 1095 if (m->m_pkthdr.len > off + sizeof(ip6e)) 1096 goto done; 1097 /* XXX sigh, this works but is totally bogus */ 1098 m_copydata(m, off, sizeof(ip6e), &ip6e); 1099 off += (ip6e.ip6e_len + 2) << 2; 1100 nxt = ip6e.ip6e_nxt; 1101 break; 1102 case IPPROTO_ICMP: 1103 spidx->ul_proto = nxt; 1104 if (off + sizeof(struct icmp) > m->m_pkthdr.len) 1105 return; 1106 m_copydata(m, off, sizeof(icmph), &icmph); 1107 ((struct sockaddr_in *)&spidx->src)->sin_port = 1108 htons((uint16_t)icmph.icmp_type); 1109 ((struct sockaddr_in *)&spidx->dst)->sin_port = 1110 htons((uint16_t)icmph.icmp_code); 1111 return; 1112 default: 1113 /* XXX intermediate headers??? */ 1114 spidx->ul_proto = nxt; 1115 goto done_proto; 1116 } 1117 } 1118 done: 1119 spidx->ul_proto = IPSEC_ULPROTO_ANY; 1120 done_proto: 1121 spidx->src.sin.sin_port = IPSEC_PORT_ANY; 1122 spidx->dst.sin.sin_port = IPSEC_PORT_ANY; 1123 } 1124 1125 /* assumes that m is sane */ 1126 static int 1127 ipsec4_setspidx_ipaddr(struct mbuf *m, struct secpolicyindex *spidx) 1128 { 1129 static const struct sockaddr_in template = { 1130 sizeof (struct sockaddr_in), 1131 AF_INET, 1132 0, { 0 }, { 0, 0, 0, 0, 0, 0, 0, 0 } 1133 }; 1134 1135 spidx->src.sin = template; 1136 spidx->dst.sin = template; 1137 1138 if (m->m_len < sizeof (struct ip)) { 1139 m_copydata(m, offsetof(struct ip, ip_src), 1140 sizeof (struct in_addr), 1141 &spidx->src.sin.sin_addr); 1142 m_copydata(m, offsetof(struct ip, ip_dst), 1143 sizeof (struct in_addr), 1144 &spidx->dst.sin.sin_addr); 1145 } else { 1146 struct ip *ip = mtod(m, struct ip *); 1147 spidx->src.sin.sin_addr = ip->ip_src; 1148 spidx->dst.sin.sin_addr = ip->ip_dst; 1149 } 1150 1151 spidx->prefs = sizeof(struct in_addr) << 3; 1152 spidx->prefd = sizeof(struct in_addr) << 3; 1153 1154 return 0; 1155 } 1156 1157 #ifdef INET6 1158 static void 1159 ipsec6_get_ulp(struct mbuf *m, struct secpolicyindex *spidx, 1160 int needport) 1161 { 1162 int off, nxt; 1163 struct tcphdr th; 1164 struct udphdr uh; 1165 struct icmp6_hdr icmph; 1166 1167 KASSERT(m != NULL); 1168 1169 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DUMP)) { 1170 printf("%s:\n", __func__); 1171 kdebug_mbuf(m); 1172 } 1173 1174 /* set default */ 1175 spidx->ul_proto = IPSEC_ULPROTO_ANY; 1176 ((struct sockaddr_in6 *)&spidx->src)->sin6_port = IPSEC_PORT_ANY; 1177 ((struct sockaddr_in6 *)&spidx->dst)->sin6_port = IPSEC_PORT_ANY; 1178 1179 nxt = -1; 1180 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt); 1181 if (off < 0 || m->m_pkthdr.len < off) 1182 return; 1183 1184 switch (nxt) { 1185 case IPPROTO_TCP: 1186 spidx->ul_proto = nxt; 1187 if (!needport) 1188 break; 1189 if (off + sizeof(struct tcphdr) > m->m_pkthdr.len) 1190 break; 1191 m_copydata(m, off, sizeof(th), &th); 1192 ((struct sockaddr_in6 *)&spidx->src)->sin6_port = th.th_sport; 1193 ((struct sockaddr_in6 *)&spidx->dst)->sin6_port = th.th_dport; 1194 break; 1195 case IPPROTO_UDP: 1196 spidx->ul_proto = nxt; 1197 if (!needport) 1198 break; 1199 if (off + sizeof(struct udphdr) > m->m_pkthdr.len) 1200 break; 1201 m_copydata(m, off, sizeof(uh), &uh); 1202 ((struct sockaddr_in6 *)&spidx->src)->sin6_port = uh.uh_sport; 1203 ((struct sockaddr_in6 *)&spidx->dst)->sin6_port = uh.uh_dport; 1204 break; 1205 case IPPROTO_ICMPV6: 1206 spidx->ul_proto = nxt; 1207 if (off + sizeof(struct icmp6_hdr) > m->m_pkthdr.len) 1208 break; 1209 m_copydata(m, off, sizeof(icmph), &icmph); 1210 ((struct sockaddr_in6 *)&spidx->src)->sin6_port = 1211 htons((uint16_t)icmph.icmp6_type); 1212 ((struct sockaddr_in6 *)&spidx->dst)->sin6_port = 1213 htons((uint16_t)icmph.icmp6_code); 1214 break; 1215 default: 1216 /* XXX intermediate headers??? */ 1217 spidx->ul_proto = nxt; 1218 break; 1219 } 1220 } 1221 1222 /* assumes that m is sane */ 1223 static int 1224 ipsec6_setspidx_ipaddr(struct mbuf *m, struct secpolicyindex *spidx) 1225 { 1226 struct ip6_hdr *ip6 = NULL; 1227 struct ip6_hdr ip6buf; 1228 struct sockaddr_in6 *sin6; 1229 1230 if (m->m_len >= sizeof(*ip6)) 1231 ip6 = mtod(m, struct ip6_hdr *); 1232 else { 1233 m_copydata(m, 0, sizeof(ip6buf), &ip6buf); 1234 ip6 = &ip6buf; 1235 } 1236 1237 sin6 = (struct sockaddr_in6 *)&spidx->src; 1238 memset(sin6, 0, sizeof(*sin6)); 1239 sin6->sin6_family = AF_INET6; 1240 sin6->sin6_len = sizeof(struct sockaddr_in6); 1241 memcpy(&sin6->sin6_addr, &ip6->ip6_src, sizeof(ip6->ip6_src)); 1242 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) { 1243 sin6->sin6_addr.s6_addr16[1] = 0; 1244 sin6->sin6_scope_id = ntohs(ip6->ip6_src.s6_addr16[1]); 1245 } 1246 spidx->prefs = sizeof(struct in6_addr) << 3; 1247 1248 sin6 = (struct sockaddr_in6 *)&spidx->dst; 1249 memset(sin6, 0, sizeof(*sin6)); 1250 sin6->sin6_family = AF_INET6; 1251 sin6->sin6_len = sizeof(struct sockaddr_in6); 1252 memcpy(&sin6->sin6_addr, &ip6->ip6_dst, sizeof(ip6->ip6_dst)); 1253 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) { 1254 sin6->sin6_addr.s6_addr16[1] = 0; 1255 sin6->sin6_scope_id = ntohs(ip6->ip6_dst.s6_addr16[1]); 1256 } 1257 spidx->prefd = sizeof(struct in6_addr) << 3; 1258 1259 return 0; 1260 } 1261 #endif 1262 1263 static void 1264 ipsec_delpcbpolicy(struct inpcbpolicy *p) 1265 { 1266 free(p, M_SECA); 1267 } 1268 1269 /* initialize policy in PCB */ 1270 int 1271 ipsec_init_policy(struct socket *so, struct inpcbpolicy **policy) 1272 { 1273 struct inpcbpolicy *new; 1274 1275 KASSERT(so != NULL); 1276 KASSERT(policy != NULL); 1277 1278 new = malloc(sizeof(*new), M_SECA, M_NOWAIT|M_ZERO); 1279 if (new == NULL) { 1280 ipseclog((LOG_DEBUG, "%s: No more memory.\n", __func__)); 1281 return ENOBUFS; 1282 } 1283 1284 if (IPSEC_PRIVILEGED_SO(so)) 1285 new->priv = 1; 1286 else 1287 new->priv = 0; 1288 1289 if ((new->sp_in = KEY_NEWSP()) == NULL) { 1290 ipsec_delpcbpolicy(new); 1291 return ENOBUFS; 1292 } 1293 new->sp_in->state = IPSEC_SPSTATE_ALIVE; 1294 new->sp_in->policy = IPSEC_POLICY_ENTRUST; 1295 1296 if ((new->sp_out = KEY_NEWSP()) == NULL) { 1297 KEY_FREESP(&new->sp_in); 1298 ipsec_delpcbpolicy(new); 1299 return ENOBUFS; 1300 } 1301 new->sp_out->state = IPSEC_SPSTATE_ALIVE; 1302 new->sp_out->policy = IPSEC_POLICY_ENTRUST; 1303 1304 *policy = new; 1305 1306 return 0; 1307 } 1308 1309 /* copy old ipsec policy into new */ 1310 int 1311 ipsec_copy_policy(const struct inpcbpolicy *old, struct inpcbpolicy *new) 1312 { 1313 struct secpolicy *sp; 1314 1315 sp = ipsec_deepcopy_policy(old->sp_in); 1316 if (sp) { 1317 KEY_FREESP(&new->sp_in); 1318 new->sp_in = sp; 1319 } else 1320 return ENOBUFS; 1321 1322 sp = ipsec_deepcopy_policy(old->sp_out); 1323 if (sp) { 1324 KEY_FREESP(&new->sp_out); 1325 new->sp_out = sp; 1326 } else 1327 return ENOBUFS; 1328 1329 new->priv = old->priv; 1330 1331 return 0; 1332 } 1333 1334 /* deep-copy a policy in PCB */ 1335 static struct secpolicy * 1336 ipsec_deepcopy_policy(const struct secpolicy *src) 1337 { 1338 struct ipsecrequest *newchain = NULL; 1339 const struct ipsecrequest *p; 1340 struct ipsecrequest **q; 1341 struct ipsecrequest *r; 1342 struct secpolicy *dst; 1343 1344 if (src == NULL) 1345 return NULL; 1346 dst = KEY_NEWSP(); 1347 if (dst == NULL) 1348 return NULL; 1349 1350 /* 1351 * deep-copy IPsec request chain. This is required since struct 1352 * ipsecrequest is not reference counted. 1353 */ 1354 q = &newchain; 1355 for (p = src->req; p; p = p->next) { 1356 *q = malloc(sizeof(**q), M_SECA, M_NOWAIT|M_ZERO); 1357 if (*q == NULL) 1358 goto fail; 1359 (*q)->next = NULL; 1360 1361 (*q)->saidx.proto = p->saidx.proto; 1362 (*q)->saidx.mode = p->saidx.mode; 1363 (*q)->level = p->level; 1364 (*q)->saidx.reqid = p->saidx.reqid; 1365 1366 memcpy(&(*q)->saidx.src, &p->saidx.src, sizeof((*q)->saidx.src)); 1367 memcpy(&(*q)->saidx.dst, &p->saidx.dst, sizeof((*q)->saidx.dst)); 1368 1369 (*q)->sav = NULL; 1370 (*q)->sp = dst; 1371 1372 q = &((*q)->next); 1373 } 1374 1375 dst->req = newchain; 1376 dst->state = src->state; 1377 dst->policy = src->policy; 1378 /* do not touch the refcnt fields */ 1379 1380 return dst; 1381 1382 fail: 1383 for (q = &newchain; *q; q = &r) { 1384 r = (*q)->next; 1385 free(*q, M_SECA); 1386 } 1387 return NULL; 1388 } 1389 1390 /* set policy and ipsec request if present. */ 1391 static int 1392 ipsec_set_policy( 1393 struct secpolicy **policy, 1394 int optname, 1395 const void *request, 1396 size_t len, 1397 kauth_cred_t cred 1398 ) 1399 { 1400 const struct sadb_x_policy *xpl; 1401 struct secpolicy *newsp = NULL; 1402 int error; 1403 1404 /* sanity check. */ 1405 if (policy == NULL || *policy == NULL || request == NULL) 1406 return EINVAL; 1407 if (len < sizeof(*xpl)) 1408 return EINVAL; 1409 xpl = (const struct sadb_x_policy *)request; 1410 1411 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DUMP)) { 1412 printf("%s: passed policy\n", __func__); 1413 kdebug_sadb_x_policy((const struct sadb_ext *)xpl); 1414 } 1415 1416 /* check policy type */ 1417 /* ipsec_set_policy() accepts IPSEC, ENTRUST and BYPASS. */ 1418 if (xpl->sadb_x_policy_type == IPSEC_POLICY_DISCARD 1419 || xpl->sadb_x_policy_type == IPSEC_POLICY_NONE) 1420 return EINVAL; 1421 1422 /* check privileged socket */ 1423 if (xpl->sadb_x_policy_type == IPSEC_POLICY_BYPASS) { 1424 error = kauth_authorize_network(cred, KAUTH_NETWORK_IPSEC, 1425 KAUTH_REQ_NETWORK_IPSEC_BYPASS, NULL, NULL, NULL); 1426 if (error) 1427 return (error); 1428 } 1429 1430 /* allocation new SP entry */ 1431 if ((newsp = key_msg2sp(xpl, len, &error)) == NULL) 1432 return error; 1433 1434 newsp->state = IPSEC_SPSTATE_ALIVE; 1435 1436 /* clear old SP and set new SP */ 1437 KEY_FREESP(policy); 1438 *policy = newsp; 1439 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DUMP)) { 1440 printf("%s: new policy\n", __func__); 1441 kdebug_secpolicy(newsp); 1442 } 1443 1444 return 0; 1445 } 1446 1447 static int 1448 ipsec_get_policy(struct secpolicy *policy, struct mbuf **mp) 1449 { 1450 1451 /* sanity check. */ 1452 if (policy == NULL || mp == NULL) 1453 return EINVAL; 1454 1455 *mp = key_sp2msg(policy); 1456 if (!*mp) { 1457 ipseclog((LOG_DEBUG, "%s: No more memory.\n", __func__)); 1458 return ENOBUFS; 1459 } 1460 1461 (*mp)->m_type = MT_DATA; 1462 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DUMP)) { 1463 printf("%s:\n", __func__); 1464 kdebug_mbuf(*mp); 1465 } 1466 1467 return 0; 1468 } 1469 1470 int 1471 ipsec4_set_policy(struct inpcb *inp, int optname, const void *request, 1472 size_t len, kauth_cred_t cred) 1473 { 1474 const struct sadb_x_policy *xpl; 1475 struct secpolicy **policy; 1476 1477 /* sanity check. */ 1478 if (inp == NULL || request == NULL) 1479 return EINVAL; 1480 if (len < sizeof(*xpl)) 1481 return EINVAL; 1482 xpl = (const struct sadb_x_policy *)request; 1483 1484 KASSERT(inp->inp_sp != NULL); 1485 1486 /* select direction */ 1487 switch (xpl->sadb_x_policy_dir) { 1488 case IPSEC_DIR_INBOUND: 1489 policy = &inp->inp_sp->sp_in; 1490 break; 1491 case IPSEC_DIR_OUTBOUND: 1492 policy = &inp->inp_sp->sp_out; 1493 break; 1494 default: 1495 ipseclog((LOG_ERR, "%s: invalid direction=%u\n", __func__, 1496 xpl->sadb_x_policy_dir)); 1497 return EINVAL; 1498 } 1499 1500 return ipsec_set_policy(policy, optname, request, len, cred); 1501 } 1502 1503 int 1504 ipsec4_get_policy(struct inpcb *inp, const void *request, size_t len, 1505 struct mbuf **mp) 1506 { 1507 const struct sadb_x_policy *xpl; 1508 struct secpolicy *policy; 1509 1510 /* sanity check. */ 1511 if (inp == NULL || request == NULL || mp == NULL) 1512 return EINVAL; 1513 KASSERT(inp->inp_sp != NULL); 1514 if (len < sizeof(*xpl)) 1515 return EINVAL; 1516 xpl = (const struct sadb_x_policy *)request; 1517 1518 /* select direction */ 1519 switch (xpl->sadb_x_policy_dir) { 1520 case IPSEC_DIR_INBOUND: 1521 policy = inp->inp_sp->sp_in; 1522 break; 1523 case IPSEC_DIR_OUTBOUND: 1524 policy = inp->inp_sp->sp_out; 1525 break; 1526 default: 1527 ipseclog((LOG_ERR, "%s: invalid direction=%u\n", __func__, 1528 xpl->sadb_x_policy_dir)); 1529 return EINVAL; 1530 } 1531 1532 return ipsec_get_policy(policy, mp); 1533 } 1534 1535 /* delete policy in PCB */ 1536 int 1537 ipsec4_delete_pcbpolicy(struct inpcb *inp) 1538 { 1539 1540 KASSERT(inp != NULL); 1541 1542 if (inp->inp_sp == NULL) 1543 return 0; 1544 1545 if (inp->inp_sp->sp_in != NULL) 1546 KEY_FREESP(&inp->inp_sp->sp_in); 1547 1548 if (inp->inp_sp->sp_out != NULL) 1549 KEY_FREESP(&inp->inp_sp->sp_out); 1550 1551 ipsec_invalpcbcache(inp->inp_sp, IPSEC_DIR_ANY); 1552 1553 ipsec_delpcbpolicy(inp->inp_sp); 1554 inp->inp_sp = NULL; 1555 1556 return 0; 1557 } 1558 1559 #ifdef INET6 1560 int 1561 ipsec6_set_policy(struct in6pcb *in6p, int optname, const void *request, 1562 size_t len, kauth_cred_t cred) 1563 { 1564 const struct sadb_x_policy *xpl; 1565 struct secpolicy **policy; 1566 1567 /* sanity check. */ 1568 if (in6p == NULL || request == NULL) 1569 return EINVAL; 1570 if (len < sizeof(*xpl)) 1571 return EINVAL; 1572 xpl = (const struct sadb_x_policy *)request; 1573 1574 /* select direction */ 1575 switch (xpl->sadb_x_policy_dir) { 1576 case IPSEC_DIR_INBOUND: 1577 policy = &in6p->in6p_sp->sp_in; 1578 break; 1579 case IPSEC_DIR_OUTBOUND: 1580 policy = &in6p->in6p_sp->sp_out; 1581 break; 1582 default: 1583 ipseclog((LOG_ERR, "%s: invalid direction=%u\n", __func__, 1584 xpl->sadb_x_policy_dir)); 1585 return EINVAL; 1586 } 1587 1588 return ipsec_set_policy(policy, optname, request, len, cred); 1589 } 1590 1591 int 1592 ipsec6_get_policy(struct in6pcb *in6p, const void *request, size_t len, 1593 struct mbuf **mp) 1594 { 1595 const struct sadb_x_policy *xpl; 1596 struct secpolicy *policy; 1597 1598 /* sanity check. */ 1599 if (in6p == NULL || request == NULL || mp == NULL) 1600 return EINVAL; 1601 KASSERT(in6p->in6p_sp != NULL); 1602 if (len < sizeof(*xpl)) 1603 return EINVAL; 1604 xpl = (const struct sadb_x_policy *)request; 1605 1606 /* select direction */ 1607 switch (xpl->sadb_x_policy_dir) { 1608 case IPSEC_DIR_INBOUND: 1609 policy = in6p->in6p_sp->sp_in; 1610 break; 1611 case IPSEC_DIR_OUTBOUND: 1612 policy = in6p->in6p_sp->sp_out; 1613 break; 1614 default: 1615 ipseclog((LOG_ERR, "%s: invalid direction=%u\n", __func__, 1616 xpl->sadb_x_policy_dir)); 1617 return EINVAL; 1618 } 1619 1620 return ipsec_get_policy(policy, mp); 1621 } 1622 1623 int 1624 ipsec6_delete_pcbpolicy(struct in6pcb *in6p) 1625 { 1626 1627 KASSERT(in6p != NULL); 1628 1629 if (in6p->in6p_sp == NULL) 1630 return 0; 1631 1632 if (in6p->in6p_sp->sp_in != NULL) 1633 KEY_FREESP(&in6p->in6p_sp->sp_in); 1634 1635 if (in6p->in6p_sp->sp_out != NULL) 1636 KEY_FREESP(&in6p->in6p_sp->sp_out); 1637 1638 ipsec_invalpcbcache(in6p->in6p_sp, IPSEC_DIR_ANY); 1639 1640 ipsec_delpcbpolicy(in6p->in6p_sp); 1641 in6p->in6p_sp = NULL; 1642 1643 return 0; 1644 } 1645 #endif 1646 1647 /* 1648 * return current level. 1649 * Either IPSEC_LEVEL_USE or IPSEC_LEVEL_REQUIRE are always returned. 1650 */ 1651 u_int 1652 ipsec_get_reqlevel(const struct ipsecrequest *isr) 1653 { 1654 u_int level = 0; 1655 u_int esp_trans_deflev, esp_net_deflev; 1656 u_int ah_trans_deflev, ah_net_deflev; 1657 1658 KASSERT(isr != NULL); 1659 KASSERT(isr->sp != NULL); 1660 KASSERTMSG( 1661 isr->sp->spidx.src.sa.sa_family == isr->sp->spidx.dst.sa.sa_family, 1662 "af family mismatch, src %u, dst %u", 1663 isr->sp->spidx.src.sa.sa_family, isr->sp->spidx.dst.sa.sa_family); 1664 1665 /* XXX note that we have ipseclog() expanded here - code sync issue */ 1666 #define IPSEC_CHECK_DEFAULT(lev) \ 1667 (((lev) != IPSEC_LEVEL_USE && (lev) != IPSEC_LEVEL_REQUIRE \ 1668 && (lev) != IPSEC_LEVEL_UNIQUE) ? \ 1669 (ipsec_debug ? log(LOG_INFO, "fixed system default level " #lev \ 1670 ":%d->%d\n", (lev), IPSEC_LEVEL_REQUIRE) : (void)0), \ 1671 (lev) = IPSEC_LEVEL_REQUIRE, (lev) \ 1672 : (lev)) 1673 1674 /* set default level */ 1675 switch (((struct sockaddr *)&isr->sp->spidx.src)->sa_family) { 1676 #ifdef INET 1677 case AF_INET: 1678 esp_trans_deflev = IPSEC_CHECK_DEFAULT(ip4_esp_trans_deflev); 1679 esp_net_deflev = IPSEC_CHECK_DEFAULT(ip4_esp_net_deflev); 1680 ah_trans_deflev = IPSEC_CHECK_DEFAULT(ip4_ah_trans_deflev); 1681 ah_net_deflev = IPSEC_CHECK_DEFAULT(ip4_ah_net_deflev); 1682 break; 1683 #endif 1684 #ifdef INET6 1685 case AF_INET6: 1686 esp_trans_deflev = IPSEC_CHECK_DEFAULT(ip6_esp_trans_deflev); 1687 esp_net_deflev = IPSEC_CHECK_DEFAULT(ip6_esp_net_deflev); 1688 ah_trans_deflev = IPSEC_CHECK_DEFAULT(ip6_ah_trans_deflev); 1689 ah_net_deflev = IPSEC_CHECK_DEFAULT(ip6_ah_net_deflev); 1690 break; 1691 #endif /* INET6 */ 1692 default: 1693 panic("%s: unknown af %u", __func__, 1694 isr->sp->spidx.src.sa.sa_family); 1695 } 1696 1697 #undef IPSEC_CHECK_DEFAULT 1698 1699 /* set level */ 1700 switch (isr->level) { 1701 case IPSEC_LEVEL_DEFAULT: 1702 switch (isr->saidx.proto) { 1703 case IPPROTO_ESP: 1704 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) 1705 level = esp_net_deflev; 1706 else 1707 level = esp_trans_deflev; 1708 break; 1709 case IPPROTO_AH: 1710 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) 1711 level = ah_net_deflev; 1712 else 1713 level = ah_trans_deflev; 1714 break; 1715 case IPPROTO_IPCOMP: 1716 /* 1717 * we don't really care, as IPcomp document says that 1718 * we shouldn't compress small packets 1719 */ 1720 level = IPSEC_LEVEL_USE; 1721 break; 1722 default: 1723 panic("%s: Illegal protocol defined %u", __func__, 1724 isr->saidx.proto); 1725 } 1726 break; 1727 1728 case IPSEC_LEVEL_USE: 1729 case IPSEC_LEVEL_REQUIRE: 1730 level = isr->level; 1731 break; 1732 case IPSEC_LEVEL_UNIQUE: 1733 level = IPSEC_LEVEL_REQUIRE; 1734 break; 1735 1736 default: 1737 panic("%s: Illegal IPsec level %u", __func__, isr->level); 1738 } 1739 1740 return level; 1741 } 1742 1743 /* 1744 * Check security policy requirements against the actual 1745 * packet contents. Return one if the packet should be 1746 * reject as "invalid"; otherwiser return zero to have the 1747 * packet treated as "valid". 1748 * 1749 * OUT: 1750 * 0: valid 1751 * 1: invalid 1752 */ 1753 int 1754 ipsec_in_reject(const struct secpolicy *sp, const struct mbuf *m) 1755 { 1756 struct ipsecrequest *isr; 1757 int need_auth; 1758 1759 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DATA)) { 1760 printf("%s: using SP\n", __func__); 1761 kdebug_secpolicy(sp); 1762 } 1763 1764 /* check policy */ 1765 switch (sp->policy) { 1766 case IPSEC_POLICY_DISCARD: 1767 return 1; 1768 case IPSEC_POLICY_BYPASS: 1769 case IPSEC_POLICY_NONE: 1770 return 0; 1771 } 1772 1773 KASSERTMSG(sp->policy == IPSEC_POLICY_IPSEC, 1774 "invalid policy %u", sp->policy); 1775 1776 /* XXX should compare policy against ipsec header history */ 1777 1778 need_auth = 0; 1779 for (isr = sp->req; isr != NULL; isr = isr->next) { 1780 if (ipsec_get_reqlevel(isr) != IPSEC_LEVEL_REQUIRE) 1781 continue; 1782 switch (isr->saidx.proto) { 1783 case IPPROTO_ESP: 1784 if ((m->m_flags & M_DECRYPTED) == 0) { 1785 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 1786 "ESP m_flags:%x\n", m->m_flags); 1787 return 1; 1788 } 1789 1790 if (!need_auth && 1791 isr->sav != NULL && 1792 isr->sav->tdb_authalgxform != NULL && 1793 (m->m_flags & M_AUTHIPDGM) == 0) { 1794 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 1795 "ESP/AH m_flags:%x\n", m->m_flags); 1796 return 1; 1797 } 1798 break; 1799 case IPPROTO_AH: 1800 need_auth = 1; 1801 if ((m->m_flags & M_AUTHIPHDR) == 0) { 1802 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 1803 "AH m_flags:%x\n", m->m_flags); 1804 return 1; 1805 } 1806 break; 1807 case IPPROTO_IPCOMP: 1808 /* 1809 * we don't really care, as IPcomp document 1810 * says that we shouldn't compress small 1811 * packets, IPComp policy should always be 1812 * treated as being in "use" level. 1813 */ 1814 break; 1815 } 1816 } 1817 return 0; /* valid */ 1818 } 1819 1820 /* 1821 * Check AH/ESP integrity. 1822 * This function is called from tcp_input(), udp_input(), 1823 * and {ah,esp}4_input for tunnel mode 1824 */ 1825 int 1826 ipsec4_in_reject(struct mbuf *m, struct inpcb *inp) 1827 { 1828 struct secpolicy *sp; 1829 int error; 1830 int result; 1831 1832 KASSERT(m != NULL); 1833 1834 /* get SP for this packet. 1835 * When we are called from ip_forward(), we call 1836 * ipsec_getpolicybyaddr() with IP_FORWARDING flag. 1837 */ 1838 if (inp == NULL) 1839 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND, IP_FORWARDING, &error); 1840 else 1841 sp = ipsec_getpolicybysock(m, IPSEC_DIR_INBOUND, 1842 (struct inpcb_hdr *)inp, &error); 1843 1844 if (sp != NULL) { 1845 result = ipsec_in_reject(sp, m); 1846 if (result) 1847 IPSEC_STATINC(IPSEC_STAT_IN_POLVIO); 1848 KEY_FREESP(&sp); 1849 } else { 1850 result = 0; /* XXX should be panic ? 1851 * -> No, there may be error. */ 1852 } 1853 return result; 1854 } 1855 1856 1857 #ifdef INET6 1858 /* 1859 * Check AH/ESP integrity. 1860 * This function is called from tcp6_input(), udp6_input(), 1861 * and {ah,esp}6_input for tunnel mode 1862 */ 1863 int 1864 ipsec6_in_reject(struct mbuf *m, struct in6pcb *in6p) 1865 { 1866 struct secpolicy *sp = NULL; 1867 int error; 1868 int result; 1869 1870 KASSERT(m != NULL); 1871 1872 /* get SP for this packet. 1873 * When we are called from ip_forward(), we call 1874 * ipsec_getpolicybyaddr() with IP_FORWARDING flag. 1875 */ 1876 if (in6p == NULL) 1877 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND, IP_FORWARDING, &error); 1878 else 1879 sp = ipsec_getpolicybysock(m, IPSEC_DIR_INBOUND, 1880 (struct inpcb_hdr *)in6p, 1881 &error); 1882 1883 if (sp != NULL) { 1884 result = ipsec_in_reject(sp, m); 1885 if (result) 1886 IPSEC_STATINC(IPSEC_STAT_IN_POLVIO); 1887 KEY_FREESP(&sp); 1888 } else { 1889 result = 0; 1890 } 1891 return result; 1892 } 1893 #endif 1894 1895 /* 1896 * compute the byte size to be occupied by IPsec header. 1897 * in case it is tunneled, it includes the size of outer IP header. 1898 * NOTE: SP passed is free in this function. 1899 */ 1900 static size_t 1901 ipsec_hdrsiz(const struct secpolicy *sp) 1902 { 1903 const struct ipsecrequest *isr; 1904 size_t siz; 1905 1906 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DATA)) { 1907 printf("%s: using SP\n", __func__); 1908 kdebug_secpolicy(sp); 1909 } 1910 1911 switch (sp->policy) { 1912 case IPSEC_POLICY_DISCARD: 1913 case IPSEC_POLICY_BYPASS: 1914 case IPSEC_POLICY_NONE: 1915 return 0; 1916 } 1917 1918 KASSERTMSG(sp->policy == IPSEC_POLICY_IPSEC, 1919 "invalid policy %u", sp->policy); 1920 1921 siz = 0; 1922 for (isr = sp->req; isr != NULL; isr = isr->next) { 1923 size_t clen = 0; 1924 1925 switch (isr->saidx.proto) { 1926 case IPPROTO_ESP: 1927 clen = esp_hdrsiz(isr->sav); 1928 break; 1929 case IPPROTO_AH: 1930 clen = ah_hdrsiz(isr->sav); 1931 break; 1932 case IPPROTO_IPCOMP: 1933 clen = sizeof(struct ipcomp); 1934 break; 1935 } 1936 1937 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) { 1938 switch (isr->saidx.dst.sa.sa_family) { 1939 case AF_INET: 1940 clen += sizeof(struct ip); 1941 break; 1942 #ifdef INET6 1943 case AF_INET6: 1944 clen += sizeof(struct ip6_hdr); 1945 break; 1946 #endif 1947 default: 1948 ipseclog((LOG_ERR, "%s: unknown AF %d in " 1949 "IPsec tunnel SA\n", __func__, 1950 ((const struct sockaddr *)&isr->saidx.dst) 1951 ->sa_family)); 1952 break; 1953 } 1954 } 1955 siz += clen; 1956 } 1957 1958 return siz; 1959 } 1960 1961 /* This function is called from ip_forward() and ipsec4_hdrsize_tcp(). */ 1962 size_t 1963 ipsec4_hdrsiz(struct mbuf *m, u_int dir, struct inpcb *inp) 1964 { 1965 struct secpolicy *sp; 1966 int error; 1967 size_t size; 1968 1969 KASSERT(m != NULL); 1970 KASSERTMSG(inp == NULL || inp->inp_socket != NULL, "socket w/o inpcb"); 1971 1972 /* get SP for this packet. 1973 * When we are called from ip_forward(), we call 1974 * ipsec_getpolicybyaddr() with IP_FORWARDING flag. 1975 */ 1976 if (inp == NULL) 1977 sp = ipsec_getpolicybyaddr(m, dir, IP_FORWARDING, &error); 1978 else 1979 sp = ipsec_getpolicybysock(m, dir, 1980 (struct inpcb_hdr *)inp, &error); 1981 1982 if (sp != NULL) { 1983 size = ipsec_hdrsiz(sp); 1984 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DATA, "size:%lu.\n", 1985 (unsigned long)size); 1986 1987 KEY_FREESP(&sp); 1988 } else { 1989 size = 0; /* XXX should be panic ? */ 1990 } 1991 return size; 1992 } 1993 1994 #ifdef INET6 1995 /* This function is called from ipsec6_hdrsize_tcp(), 1996 * and maybe from ip6_forward.() 1997 */ 1998 size_t 1999 ipsec6_hdrsiz(struct mbuf *m, u_int dir, struct in6pcb *in6p) 2000 { 2001 struct secpolicy *sp; 2002 int error; 2003 size_t size; 2004 2005 KASSERT(m != NULL); 2006 KASSERTMSG(in6p == NULL || in6p->in6p_socket != NULL, 2007 "socket w/o inpcb"); 2008 2009 /* get SP for this packet */ 2010 /* XXX Is it right to call with IP_FORWARDING. */ 2011 if (in6p == NULL) 2012 sp = ipsec_getpolicybyaddr(m, dir, IP_FORWARDING, &error); 2013 else 2014 sp = ipsec_getpolicybysock(m, dir, 2015 (struct inpcb_hdr *)in6p, 2016 &error); 2017 2018 if (sp == NULL) 2019 return 0; 2020 size = ipsec_hdrsiz(sp); 2021 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DATA, "size:%zu.\n", size); 2022 KEY_FREESP(&sp); 2023 2024 return size; 2025 } 2026 #endif /*INET6*/ 2027 2028 /* 2029 * Check the variable replay window. 2030 * ipsec_chkreplay() performs replay check before ICV verification. 2031 * ipsec_updatereplay() updates replay bitmap. This must be called after 2032 * ICV verification (it also performs replay check, which is usually done 2033 * beforehand). 2034 * 0 (zero) is returned if packet disallowed, 1 if packet permitted. 2035 * 2036 * based on RFC 2401. 2037 */ 2038 int 2039 ipsec_chkreplay(u_int32_t seq, const struct secasvar *sav) 2040 { 2041 const struct secreplay *replay; 2042 u_int32_t diff; 2043 int fr; 2044 u_int32_t wsizeb; /* constant: bits of window size */ 2045 int frlast; /* constant: last frame */ 2046 2047 IPSEC_SPLASSERT_SOFTNET(__func__); 2048 2049 KASSERT(sav != NULL); 2050 KASSERT(sav->replay != NULL); 2051 2052 replay = sav->replay; 2053 2054 if (replay->wsize == 0) 2055 return 1; /* no need to check replay. */ 2056 2057 /* constant */ 2058 frlast = replay->wsize - 1; 2059 wsizeb = replay->wsize << 3; 2060 2061 /* sequence number of 0 is invalid */ 2062 if (seq == 0) 2063 return 0; 2064 2065 /* first time is always okay */ 2066 if (replay->count == 0) 2067 return 1; 2068 2069 if (seq > replay->lastseq) { 2070 /* larger sequences are okay */ 2071 return 1; 2072 } else { 2073 /* seq is equal or less than lastseq. */ 2074 diff = replay->lastseq - seq; 2075 2076 /* over range to check, i.e. too old or wrapped */ 2077 if (diff >= wsizeb) 2078 return 0; 2079 2080 fr = frlast - diff / 8; 2081 2082 /* this packet already seen ? */ 2083 if ((replay->bitmap)[fr] & (1 << (diff % 8))) 2084 return 0; 2085 2086 /* out of order but good */ 2087 return 1; 2088 } 2089 } 2090 2091 /* 2092 * check replay counter whether to update or not. 2093 * OUT: 0: OK 2094 * 1: NG 2095 */ 2096 int 2097 ipsec_updatereplay(u_int32_t seq, const struct secasvar *sav) 2098 { 2099 struct secreplay *replay; 2100 u_int32_t diff; 2101 int fr; 2102 u_int32_t wsizeb; /* constant: bits of window size */ 2103 int frlast; /* constant: last frame */ 2104 2105 IPSEC_SPLASSERT_SOFTNET(__func__); 2106 2107 KASSERT(sav != NULL); 2108 KASSERT(sav->replay != NULL); 2109 2110 replay = sav->replay; 2111 2112 if (replay->wsize == 0) 2113 goto ok; /* no need to check replay. */ 2114 2115 /* constant */ 2116 frlast = replay->wsize - 1; 2117 wsizeb = replay->wsize << 3; 2118 2119 /* sequence number of 0 is invalid */ 2120 if (seq == 0) 2121 return 1; 2122 2123 /* first time */ 2124 if (replay->count == 0) { 2125 replay->lastseq = seq; 2126 memset(replay->bitmap, 0, replay->wsize); 2127 (replay->bitmap)[frlast] = 1; 2128 goto ok; 2129 } 2130 2131 if (seq > replay->lastseq) { 2132 /* seq is larger than lastseq. */ 2133 diff = seq - replay->lastseq; 2134 2135 /* new larger sequence number */ 2136 if (diff < wsizeb) { 2137 /* In window */ 2138 /* set bit for this packet */ 2139 vshiftl(replay->bitmap, diff, replay->wsize); 2140 (replay->bitmap)[frlast] |= 1; 2141 } else { 2142 /* this packet has a "way larger" */ 2143 memset(replay->bitmap, 0, replay->wsize); 2144 (replay->bitmap)[frlast] = 1; 2145 } 2146 replay->lastseq = seq; 2147 2148 /* larger is good */ 2149 } else { 2150 /* seq is equal or less than lastseq. */ 2151 diff = replay->lastseq - seq; 2152 2153 /* over range to check, i.e. too old or wrapped */ 2154 if (diff >= wsizeb) 2155 return 1; 2156 2157 fr = frlast - diff / 8; 2158 2159 /* this packet already seen ? */ 2160 if ((replay->bitmap)[fr] & (1 << (diff % 8))) 2161 return 1; 2162 2163 /* mark as seen */ 2164 (replay->bitmap)[fr] |= (1 << (diff % 8)); 2165 2166 /* out of order but good */ 2167 } 2168 2169 ok: 2170 if (replay->count == ~0) { 2171 2172 /* set overflow flag */ 2173 replay->overflow++; 2174 2175 /* don't increment, no more packets accepted */ 2176 if ((sav->flags & SADB_X_EXT_CYCSEQ) == 0) 2177 return 1; 2178 2179 ipseclog((LOG_WARNING, "replay counter made %d cycle. %s\n", 2180 replay->overflow, ipsec_logsastr(sav))); 2181 } 2182 2183 replay->count++; 2184 2185 return 0; 2186 } 2187 2188 /* 2189 * shift variable length bunffer to left. 2190 * IN: bitmap: pointer to the buffer 2191 * nbit: the number of to shift. 2192 * wsize: buffer size (bytes). 2193 */ 2194 static void 2195 vshiftl(unsigned char *bitmap, int nbit, int wsize) 2196 { 2197 int s, j, i; 2198 unsigned char over; 2199 2200 for (j = 0; j < nbit; j += 8) { 2201 s = (nbit - j < 8) ? (nbit - j): 8; 2202 bitmap[0] <<= s; 2203 for (i = 1; i < wsize; i++) { 2204 over = (bitmap[i] >> (8 - s)); 2205 bitmap[i] <<= s; 2206 bitmap[i-1] |= over; 2207 } 2208 } 2209 2210 return; 2211 } 2212 2213 /* Return a printable string for the IPv4 address. */ 2214 static char * 2215 inet_ntoa4(struct in_addr ina) 2216 { 2217 static char buf[4][4 * sizeof "123" + 4]; 2218 unsigned char *ucp = (unsigned char *) &ina; 2219 static int i = 3; 2220 2221 i = (i + 1) % 4; 2222 snprintf(buf[i], sizeof(buf[i]), "%d.%d.%d.%d", 2223 ucp[0] & 0xff, ucp[1] & 0xff, ucp[2] & 0xff, ucp[3] & 0xff); 2224 return (buf[i]); 2225 } 2226 2227 /* Return a printable string for the address. */ 2228 const char * 2229 ipsec_address(const union sockaddr_union *sa) 2230 { 2231 #if INET6 2232 static char ip6buf[INET6_ADDRSTRLEN]; /* XXX: NOMPSAFE */ 2233 #endif 2234 2235 switch (sa->sa.sa_family) { 2236 #if INET 2237 case AF_INET: 2238 return inet_ntoa4(sa->sin.sin_addr); 2239 #endif /* INET */ 2240 2241 #if INET6 2242 case AF_INET6: 2243 return IN6_PRINT(ip6buf, &sa->sin6.sin6_addr); 2244 #endif /* INET6 */ 2245 2246 default: 2247 return "(unknown address family)"; 2248 } 2249 } 2250 2251 const char * 2252 ipsec_logsastr(const struct secasvar *sav) 2253 { 2254 static char buf[256]; 2255 char *p; 2256 const struct secasindex *saidx = &sav->sah->saidx; 2257 2258 KASSERTMSG(saidx->src.sa.sa_family == saidx->dst.sa.sa_family, 2259 "af family mismatch, src %u, dst %u", 2260 saidx->src.sa.sa_family, saidx->dst.sa.sa_family); 2261 2262 p = buf; 2263 snprintf(buf, sizeof(buf), "SA(SPI=%u ", (u_int32_t)ntohl(sav->spi)); 2264 while (p && *p) 2265 p++; 2266 /* NB: only use ipsec_address on one address at a time */ 2267 snprintf(p, sizeof (buf) - (p - buf), "src=%s ", 2268 ipsec_address(&saidx->src)); 2269 while (p && *p) 2270 p++; 2271 snprintf(p, sizeof (buf) - (p - buf), "dst=%s)", 2272 ipsec_address(&saidx->dst)); 2273 2274 return buf; 2275 } 2276 2277 void 2278 ipsec_dumpmbuf(struct mbuf *m) 2279 { 2280 int totlen; 2281 int i; 2282 u_char *p; 2283 2284 totlen = 0; 2285 printf("---\n"); 2286 while (m) { 2287 p = mtod(m, u_char *); 2288 for (i = 0; i < m->m_len; i++) { 2289 printf("%02x ", p[i]); 2290 totlen++; 2291 if (totlen % 16 == 0) 2292 printf("\n"); 2293 } 2294 m = m->m_next; 2295 } 2296 if (totlen % 16 != 0) 2297 printf("\n"); 2298 printf("---\n"); 2299 } 2300 2301 #ifdef INET6 2302 struct secpolicy * 2303 ipsec6_check_policy(struct mbuf *m, struct in6pcb *in6p, 2304 int flags, int *needipsecp, int *errorp) 2305 { 2306 struct secpolicy *sp = NULL; 2307 int s; 2308 int error = 0; 2309 int needipsec = 0; 2310 2311 if (!ipsec_outdone(m)) { 2312 s = splsoftnet(); 2313 if (in6p != NULL && 2314 IPSEC_PCB_SKIP_IPSEC(in6p->in6p_sp, IPSEC_DIR_OUTBOUND)) { 2315 splx(s); 2316 goto skippolicycheck; 2317 } 2318 sp = ipsec6_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags, &error,in6p); 2319 2320 /* 2321 * There are four return cases: 2322 * sp != NULL apply IPsec policy 2323 * sp == NULL, error == 0 no IPsec handling needed 2324 * sp == NULL, error == -EINVAL discard packet w/o error 2325 * sp == NULL, error != 0 discard packet, report error 2326 */ 2327 2328 splx(s); 2329 if (sp == NULL) { 2330 /* 2331 * Caller must check the error return to see if it needs to discard 2332 * the packet. 2333 */ 2334 needipsec = 0; 2335 } else { 2336 needipsec = 1; 2337 } 2338 } 2339 skippolicycheck:; 2340 2341 *errorp = error; 2342 *needipsecp = needipsec; 2343 return sp; 2344 } 2345 2346 int 2347 ipsec6_input(struct mbuf *m) 2348 { 2349 struct m_tag *mtag; 2350 struct tdb_ident *tdbi; 2351 struct secpolicy *sp; 2352 int s, error; 2353 2354 /* 2355 * Check if the packet has already had IPsec 2356 * processing done. If so, then just pass it 2357 * along. This tag gets set during AH, ESP, 2358 * etc. input handling, before the packet is 2359 * returned to the ip input queue for delivery. 2360 */ 2361 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, 2362 NULL); 2363 s = splsoftnet(); 2364 if (mtag != NULL) { 2365 tdbi = (struct tdb_ident *)(mtag + 1); 2366 sp = ipsec_getpolicy(tdbi, 2367 IPSEC_DIR_INBOUND); 2368 } else { 2369 sp = ipsec_getpolicybyaddr(m, 2370 IPSEC_DIR_INBOUND, IP_FORWARDING, 2371 &error); 2372 } 2373 if (sp != NULL) { 2374 /* 2375 * Check security policy against packet 2376 * attributes. 2377 */ 2378 error = ipsec_in_reject(sp, m); 2379 KEY_FREESP(&sp); 2380 } else { 2381 /* XXX error stat??? */ 2382 error = EINVAL; 2383 DPRINTF(("%s: no SP, packet discarded\n", __func__));/*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 Mon Sep 22 05:09:51 GMT 2025