ipsec.c revision 1.92
1 /* $NetBSD: ipsec.c,v 1.92 2017/05/19 04:34:09 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 1.92 2017/05/19 04:34:09 ozaki-r Exp $"); 36 37 /* 38 * IPsec controller part. 39 */ 40 41 #if defined(_KERNEL_OPT) 42 #include "opt_inet.h" 43 #include "opt_ipsec.h" 44 #endif 45 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 #include <sys/mbuf.h> 49 #include <sys/domain.h> 50 #include <sys/protosw.h> 51 #include <sys/socket.h> 52 #include <sys/socketvar.h> 53 #include <sys/errno.h> 54 #include <sys/time.h> 55 #include <sys/kernel.h> 56 #include <sys/syslog.h> 57 #include <sys/sysctl.h> 58 #include <sys/proc.h> 59 #include <sys/kauth.h> 60 #include <sys/cpu.h> 61 #include <sys/kmem.h> 62 63 #include <net/if.h> 64 #include <net/route.h> 65 66 #include <netinet/in.h> 67 #include <netinet/in_systm.h> 68 #include <netinet/ip.h> 69 #include <netinet/ip_var.h> 70 #include <netinet/in_var.h> 71 #include <netinet/udp.h> 72 #include <netinet/udp_var.h> 73 #include <netinet/tcp.h> 74 #include <netinet/udp.h> 75 #include <netinet/ip_icmp.h> 76 #include <netinet/ip_private.h> 77 78 #include <netinet/ip6.h> 79 #ifdef INET6 80 #include <netinet6/ip6_var.h> 81 #endif 82 #include <netinet/in_pcb.h> 83 #ifdef INET6 84 #include <netinet6/in6_pcb.h> 85 #include <netinet/icmp6.h> 86 #endif 87 88 #include <netipsec/ipsec.h> 89 #include <netipsec/ipsec_var.h> 90 #include <netipsec/ipsec_private.h> 91 #ifdef INET6 92 #include <netipsec/ipsec6.h> 93 #endif 94 #include <netipsec/ah_var.h> 95 #include <netipsec/esp_var.h> 96 #include <netipsec/ipcomp.h> /*XXX*/ 97 #include <netipsec/ipcomp_var.h> 98 99 #include <netipsec/key.h> 100 #include <netipsec/keydb.h> 101 #include <netipsec/key_debug.h> 102 103 #include <netipsec/xform.h> 104 105 #include <net/net_osdep.h> 106 107 int ipsec_used = 0; 108 int ipsec_enabled = 1; 109 110 #ifdef IPSEC_DEBUG 111 int ipsec_debug = 1; 112 113 /* 114 * When set to 1, IPsec will send packets with the same sequence number. 115 * This allows to verify if the other side has proper replay attacks detection. 116 */ 117 int ipsec_replay = 0; 118 119 /* 120 * When set 1, IPsec will send packets with corrupted HMAC. 121 * This allows to verify if the other side properly detects modified packets. 122 */ 123 int ipsec_integrity = 0; 124 #else 125 int ipsec_debug = 0; 126 #endif 127 128 percpu_t *ipsecstat_percpu; 129 int ip4_ah_offsetmask = 0; /* maybe IP_DF? */ 130 int ip4_ipsec_dfbit = 2; /* DF bit on encap. 0: clear 1: set 2: copy */ 131 int ip4_esp_trans_deflev = IPSEC_LEVEL_USE; 132 int ip4_esp_net_deflev = IPSEC_LEVEL_USE; 133 int ip4_ah_trans_deflev = IPSEC_LEVEL_USE; 134 int ip4_ah_net_deflev = IPSEC_LEVEL_USE; 135 struct secpolicy ip4_def_policy; 136 int ip4_ipsec_ecn = 0; /* ECN ignore(-1)/forbidden(0)/allowed(1) */ 137 int ip4_esp_randpad = -1; 138 139 u_int ipsec_spdgen = 1; /* SPD generation # */ 140 141 static struct secpolicy *ipsec_checkpcbcache (struct mbuf *, 142 struct inpcbpolicy *, int); 143 static int ipsec_fillpcbcache (struct inpcbpolicy *, struct mbuf *, 144 struct secpolicy *, int); 145 static int ipsec_invalpcbcache (struct inpcbpolicy *, int); 146 147 /* 148 * Crypto support requirements: 149 * 150 * 1 require hardware support 151 * -1 require software support 152 * 0 take anything 153 */ 154 int crypto_support = 0; 155 156 static struct secpolicy *ipsec_getpolicybysock(struct mbuf *, u_int, 157 struct inpcb_hdr *, int *); 158 159 #ifdef __FreeBSD__ 160 /* net.inet.ipsec */ 161 SYSCTL_INT(_net_inet_ipsec, IPSECCTL_ESP_RANDPAD, 162 esp_randpad, CTLFLAG_RW, &ip4_esp_randpad, 0, ""); 163 SYSCTL_INT(_net_inet_ipsec, OID_AUTO, 164 crypto_support, CTLFLAG_RW, &crypto_support,0, ""); 165 SYSCTL_INT(_net_inet_ipsec, OID_AUTO, test_replay, CTLFLAG_RW, &ipsec_replay, 0, 166 "Emulate replay attack"); 167 SYSCTL_INT(_net_inet_ipsec, OID_AUTO, test_integrity, CTLFLAG_RW, 168 &ipsec_integrity, 0, "Emulate man-in-the-middle attack"); 169 #endif /* __FreeBSD__ */ 170 171 #ifdef INET6 172 int ip6_esp_trans_deflev = IPSEC_LEVEL_USE; 173 int ip6_esp_net_deflev = IPSEC_LEVEL_USE; 174 int ip6_ah_trans_deflev = IPSEC_LEVEL_USE; 175 int ip6_ah_net_deflev = IPSEC_LEVEL_USE; 176 struct secpolicy ip6_def_policy; 177 int ip6_ipsec_ecn = 0; /* ECN ignore(-1)/forbidden(0)/allowed(1) */ 178 int ip6_esp_randpad = -1; 179 180 181 #ifdef __FreeBSD__ 182 /* net.inet6.ipsec6 */ 183 SYSCTL_INT(_net_inet6_ipsec6, IPSECCTL_ESP_RANDPAD, 184 esp_randpad, CTLFLAG_RW, &ip6_esp_randpad, 0, ""); 185 #endif /* __FreeBSD__ */ 186 #endif /* INET6 */ 187 188 static int ipsec4_setspidx_inpcb (struct mbuf *, struct inpcb *); 189 #ifdef INET6 190 static int ipsec6_setspidx_in6pcb (struct mbuf *, struct in6pcb *); 191 #endif 192 static int ipsec_setspidx (struct mbuf *, struct secpolicyindex *, int); 193 static void ipsec4_get_ulp (struct mbuf *m, struct secpolicyindex *, int); 194 static int ipsec4_setspidx_ipaddr (struct mbuf *, struct secpolicyindex *); 195 #ifdef INET6 196 static void ipsec6_get_ulp (struct mbuf *m, struct secpolicyindex *, int); 197 static int ipsec6_setspidx_ipaddr (struct mbuf *, struct secpolicyindex *); 198 #endif 199 static void ipsec_delpcbpolicy (struct inpcbpolicy *); 200 static struct secpolicy *ipsec_deepcopy_policy (const struct secpolicy *); 201 static int ipsec_set_policy (struct secpolicy **, int, const void *, size_t, 202 kauth_cred_t); 203 static int ipsec_get_policy (struct secpolicy *, struct mbuf **); 204 static void vshiftl (unsigned char *, int, int); 205 static size_t ipsec_hdrsiz (const struct secpolicy *); 206 207 /* 208 * Try to validate and use cached policy on a PCB. 209 */ 210 static struct secpolicy * 211 ipsec_checkpcbcache(struct mbuf *m, struct inpcbpolicy *pcbsp, int dir) 212 { 213 struct secpolicyindex spidx; 214 215 KASSERT(IPSEC_DIR_IS_VALID(dir)); 216 KASSERT(pcbsp != NULL); 217 KASSERT(dir < sizeof(pcbsp->sp_cache)/sizeof(pcbsp->sp_cache[0])); 218 KASSERT(inph_locked(pcbsp->sp_inph)); 219 220 /* SPD table change invalidate all the caches. */ 221 if (ipsec_spdgen != pcbsp->sp_cache[dir].cachegen) { 222 ipsec_invalpcbcache(pcbsp, dir); 223 return NULL; 224 } 225 if (!pcbsp->sp_cache[dir].cachesp) 226 return NULL; 227 if (pcbsp->sp_cache[dir].cachesp->state != IPSEC_SPSTATE_ALIVE) { 228 ipsec_invalpcbcache(pcbsp, dir); 229 return NULL; 230 } 231 if ((pcbsp->sp_cacheflags & IPSEC_PCBSP_CONNECTED) == 0) { 232 if (!pcbsp->sp_cache[dir].cachesp) 233 return NULL; 234 if (ipsec_setspidx(m, &spidx, 1) != 0) 235 return NULL; 236 237 /* 238 * We have to make an exact match here since the cached rule 239 * might have lower priority than a rule that would otherwise 240 * have matched the packet. 241 */ 242 243 if (memcmp(&pcbsp->sp_cache[dir].cacheidx, &spidx, sizeof(spidx))) 244 return NULL; 245 246 } else { 247 /* 248 * The pcb is connected, and the L4 code is sure that: 249 * - outgoing side uses inp_[lf]addr 250 * - incoming side looks up policy after inpcb lookup 251 * and address pair is know to be stable. We do not need 252 * to generate spidx again, nor check the address match again. 253 * 254 * For IPv4/v6 SOCK_STREAM sockets, this assumptions holds 255 * and there are calls to ipsec_pcbconn() from in_pcbconnect(). 256 */ 257 } 258 259 pcbsp->sp_cache[dir].cachesp->lastused = time_second; 260 pcbsp->sp_cache[dir].cachesp->refcnt++; 261 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_STAMP, 262 "DP cause refcnt++:%d SP:%p\n", 263 pcbsp->sp_cache[dir].cachesp->refcnt, 264 pcbsp->sp_cache[dir].cachesp); 265 return pcbsp->sp_cache[dir].cachesp; 266 } 267 268 static int 269 ipsec_fillpcbcache(struct inpcbpolicy *pcbsp, struct mbuf *m, 270 struct secpolicy *sp, int dir) 271 { 272 273 KASSERT(IPSEC_DIR_IS_INOROUT(dir)); 274 KASSERT(dir < sizeof(pcbsp->sp_cache)/sizeof(pcbsp->sp_cache[0])); 275 KASSERT(inph_locked(pcbsp->sp_inph)); 276 277 if (pcbsp->sp_cache[dir].cachesp) 278 KEY_FREESP(&pcbsp->sp_cache[dir].cachesp); 279 pcbsp->sp_cache[dir].cachesp = NULL; 280 pcbsp->sp_cache[dir].cachehint = IPSEC_PCBHINT_MAYBE; 281 if (ipsec_setspidx(m, &pcbsp->sp_cache[dir].cacheidx, 1) != 0) { 282 return EINVAL; 283 } 284 pcbsp->sp_cache[dir].cachesp = sp; 285 if (pcbsp->sp_cache[dir].cachesp) { 286 pcbsp->sp_cache[dir].cachesp->refcnt++; 287 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_STAMP, 288 "DP cause refcnt++:%d SP:%p\n", 289 pcbsp->sp_cache[dir].cachesp->refcnt, 290 pcbsp->sp_cache[dir].cachesp); 291 292 /* 293 * If the PCB is connected, we can remember a hint to 294 * possibly short-circuit IPsec processing in other places. 295 */ 296 if (pcbsp->sp_cacheflags & IPSEC_PCBSP_CONNECTED) { 297 switch (pcbsp->sp_cache[dir].cachesp->policy) { 298 case IPSEC_POLICY_NONE: 299 case IPSEC_POLICY_BYPASS: 300 pcbsp->sp_cache[dir].cachehint = 301 IPSEC_PCBHINT_NO; 302 break; 303 default: 304 pcbsp->sp_cache[dir].cachehint = 305 IPSEC_PCBHINT_YES; 306 } 307 } 308 } 309 pcbsp->sp_cache[dir].cachegen = ipsec_spdgen; 310 311 return 0; 312 } 313 314 static int 315 ipsec_invalpcbcache(struct inpcbpolicy *pcbsp, int dir) 316 { 317 int i; 318 319 KASSERT(inph_locked(pcbsp->sp_inph)); 320 321 for (i = IPSEC_DIR_INBOUND; i <= IPSEC_DIR_OUTBOUND; i++) { 322 if (dir != IPSEC_DIR_ANY && i != dir) 323 continue; 324 if (pcbsp->sp_cache[i].cachesp) 325 KEY_FREESP(&pcbsp->sp_cache[i].cachesp); 326 pcbsp->sp_cache[i].cachesp = NULL; 327 pcbsp->sp_cache[i].cachehint = IPSEC_PCBHINT_MAYBE; 328 pcbsp->sp_cache[i].cachegen = 0; 329 memset(&pcbsp->sp_cache[i].cacheidx, 0, 330 sizeof(pcbsp->sp_cache[i].cacheidx)); 331 } 332 return 0; 333 } 334 335 void 336 ipsec_pcbconn(struct inpcbpolicy *pcbsp) 337 { 338 339 KASSERT(inph_locked(pcbsp->sp_inph)); 340 341 pcbsp->sp_cacheflags |= IPSEC_PCBSP_CONNECTED; 342 ipsec_invalpcbcache(pcbsp, IPSEC_DIR_ANY); 343 } 344 345 void 346 ipsec_pcbdisconn(struct inpcbpolicy *pcbsp) 347 { 348 349 KASSERT(inph_locked(pcbsp->sp_inph)); 350 351 pcbsp->sp_cacheflags &= ~IPSEC_PCBSP_CONNECTED; 352 ipsec_invalpcbcache(pcbsp, IPSEC_DIR_ANY); 353 } 354 355 void 356 ipsec_invalpcbcacheall(void) 357 { 358 359 if (ipsec_spdgen == UINT_MAX) 360 ipsec_spdgen = 1; 361 else 362 ipsec_spdgen++; 363 } 364 365 /* 366 * Return a held reference to the default SP. 367 */ 368 static struct secpolicy * 369 key_allocsp_default(int af, const char *where, int tag) 370 { 371 struct secpolicy *sp; 372 373 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_STAMP, "DP from %s:%u\n", where, tag); 374 375 switch(af) { 376 case AF_INET: 377 sp = &ip4_def_policy; 378 break; 379 #ifdef INET6 380 case AF_INET6: 381 sp = &ip6_def_policy; 382 break; 383 #endif 384 default: 385 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_STAMP, 386 "unexpected protocol family %u\n", af); 387 return NULL; 388 } 389 390 if (sp->policy != IPSEC_POLICY_DISCARD && 391 sp->policy != IPSEC_POLICY_NONE) { 392 IPSECLOG(LOG_INFO, "fixed system default policy: %d->%d\n", 393 sp->policy, IPSEC_POLICY_NONE); 394 sp->policy = IPSEC_POLICY_NONE; 395 } 396 sp->refcnt++; 397 398 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_STAMP, "DP returns SP:%p (%u)\n", 399 sp, sp->refcnt); 400 return sp; 401 } 402 #define KEY_ALLOCSP_DEFAULT(af) \ 403 key_allocsp_default((af), __func__, __LINE__) 404 405 /* 406 * For OUTBOUND packet having a socket. Searching SPD for packet, 407 * and return a pointer to SP. 408 * OUT: NULL: no apropreate SP found, the following value is set to error. 409 * 0 : bypass 410 * EACCES : discard packet. 411 * ENOENT : ipsec_acquire() in progress, maybe. 412 * others : error occurred. 413 * others: a pointer to SP 414 * 415 * NOTE: IPv6 mapped address concern is implemented here. 416 */ 417 struct secpolicy * 418 ipsec_getpolicy(const struct tdb_ident *tdbi, u_int dir) 419 { 420 struct secpolicy *sp; 421 422 KASSERT(tdbi != NULL); 423 KASSERTMSG(IPSEC_DIR_IS_INOROUT(dir), "invalid direction %u", dir); 424 425 sp = KEY_ALLOCSP2(tdbi->spi, &tdbi->dst, tdbi->proto, dir); 426 if (sp == NULL) /*XXX????*/ 427 sp = KEY_ALLOCSP_DEFAULT(tdbi->dst.sa.sa_family); 428 KASSERT(sp != NULL); 429 return sp; 430 } 431 432 /* 433 * For OUTBOUND packet having a socket. Searching SPD for packet, 434 * and return a pointer to SP. 435 * OUT: NULL: no apropreate SP found, the following value is set to error. 436 * 0 : bypass 437 * EACCES : discard packet. 438 * ENOENT : ipsec_acquire() in progress, maybe. 439 * others : error occurred. 440 * others: a pointer to SP 441 * 442 * NOTE: IPv6 mapped address concern is implemented here. 443 */ 444 static struct secpolicy * 445 ipsec_getpolicybysock(struct mbuf *m, u_int dir, struct inpcb_hdr *inph, 446 int *error) 447 { 448 struct inpcbpolicy *pcbsp = NULL; 449 struct secpolicy *currsp = NULL; /* policy on socket */ 450 struct secpolicy *sp; 451 int af; 452 453 KASSERT(m != NULL); 454 KASSERT(inph != NULL); 455 KASSERT(error != NULL); 456 KASSERTMSG(IPSEC_DIR_IS_INOROUT(dir), "invalid direction %u", dir); 457 458 KASSERT(inph->inph_socket != NULL); 459 KASSERT(inph_locked(inph)); 460 461 /* XXX FIXME inpcb/in6pcb vs socket*/ 462 af = inph->inph_af; 463 KASSERTMSG(af == AF_INET || af == AF_INET6, 464 "unexpected protocol family %u", af); 465 466 KASSERT(inph->inph_sp != NULL); 467 /* If we have a cached entry, and if it is still valid, use it. */ 468 IPSEC_STATINC(IPSEC_STAT_SPDCACHELOOKUP); 469 currsp = ipsec_checkpcbcache(m, inph->inph_sp, dir); 470 if (currsp) { 471 *error = 0; 472 return currsp; 473 } 474 IPSEC_STATINC(IPSEC_STAT_SPDCACHEMISS); 475 476 switch (af) { 477 case AF_INET: { 478 struct inpcb *in4p = (struct inpcb *)inph; 479 /* set spidx in pcb */ 480 *error = ipsec4_setspidx_inpcb(m, in4p); 481 pcbsp = in4p->inp_sp; 482 break; 483 } 484 485 #if defined(INET6) 486 case AF_INET6: { 487 struct in6pcb *in6p = (struct in6pcb *)inph; 488 /* set spidx in pcb */ 489 *error = ipsec6_setspidx_in6pcb(m, in6p); 490 pcbsp = in6p->in6p_sp; 491 break; 492 } 493 #endif 494 default: 495 *error = EPFNOSUPPORT; 496 break; 497 } 498 if (*error) 499 return NULL; 500 501 KASSERT(pcbsp != NULL); 502 switch (dir) { 503 case IPSEC_DIR_INBOUND: 504 currsp = pcbsp->sp_in; 505 break; 506 case IPSEC_DIR_OUTBOUND: 507 currsp = pcbsp->sp_out; 508 break; 509 } 510 KASSERT(currsp != NULL); 511 512 if (pcbsp->priv) { /* when privilieged socket */ 513 switch (currsp->policy) { 514 case IPSEC_POLICY_BYPASS: 515 case IPSEC_POLICY_IPSEC: 516 currsp->refcnt++; 517 sp = currsp; 518 break; 519 520 case IPSEC_POLICY_ENTRUST: 521 /* look for a policy in SPD */ 522 sp = KEY_ALLOCSP(&currsp->spidx, dir); 523 if (sp == NULL) /* no SP found */ 524 sp = KEY_ALLOCSP_DEFAULT(af); 525 break; 526 527 default: 528 IPSECLOG(LOG_ERR, "Invalid policy for PCB %d\n", 529 currsp->policy); 530 *error = EINVAL; 531 return NULL; 532 } 533 } else { /* unpriv, SPD has policy */ 534 sp = KEY_ALLOCSP(&currsp->spidx, dir); 535 if (sp == NULL) { /* no SP found */ 536 switch (currsp->policy) { 537 case IPSEC_POLICY_BYPASS: 538 IPSECLOG(LOG_ERR, "Illegal policy for " 539 "non-priviliged defined %d\n", 540 currsp->policy); 541 *error = EINVAL; 542 return NULL; 543 544 case IPSEC_POLICY_ENTRUST: 545 sp = KEY_ALLOCSP_DEFAULT(af); 546 break; 547 548 case IPSEC_POLICY_IPSEC: 549 currsp->refcnt++; 550 sp = currsp; 551 break; 552 553 default: 554 IPSECLOG(LOG_ERR, "Invalid policy for " 555 "PCB %d\n", currsp->policy); 556 *error = EINVAL; 557 return NULL; 558 } 559 } 560 } 561 KASSERTMSG(sp != NULL, "null SP (priv %u policy %u", pcbsp->priv, 562 currsp->policy); 563 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_STAMP, 564 "DP (priv %u policy %u) allocates SP:%p (refcnt %u)\n", 565 pcbsp->priv, currsp->policy, sp, sp->refcnt); 566 ipsec_fillpcbcache(pcbsp, m, sp, dir); 567 return sp; 568 } 569 570 /* 571 * For FORWADING packet or OUTBOUND without a socket. Searching SPD for packet, 572 * and return a pointer to SP. 573 * OUT: positive: a pointer to the entry for security policy leaf matched. 574 * NULL: no apropreate SP found, the following value is set to error. 575 * 0 : bypass 576 * EACCES : discard packet. 577 * ENOENT : ipsec_acquire() in progress, maybe. 578 * others : error occurred. 579 */ 580 struct secpolicy * 581 ipsec_getpolicybyaddr(struct mbuf *m, u_int dir, int flag, int *error) 582 { 583 struct secpolicyindex spidx; 584 struct secpolicy *sp; 585 586 KASSERT(m != NULL); 587 KASSERT(error != NULL); 588 KASSERTMSG(IPSEC_DIR_IS_INOROUT(dir), "invalid direction %u", dir); 589 590 sp = NULL; 591 592 /* Make an index to look for a policy. */ 593 *error = ipsec_setspidx(m, &spidx, (flag & IP_FORWARDING) ? 0 : 1); 594 if (*error != 0) { 595 IPSECLOG(LOG_DEBUG, "setpidx failed, dir %u flag %u\n", 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 IPSECLOG(LOG_DEBUG, "done, error %d\n", *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 IPSECLOG(LOG_DEBUG, "done, error %d\n", *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 1267 kmem_intr_free(p, sizeof(*p)); 1268 } 1269 1270 /* initialize policy in PCB */ 1271 int 1272 ipsec_init_policy(struct socket *so, struct inpcbpolicy **policy) 1273 { 1274 struct inpcbpolicy *new; 1275 1276 KASSERT(so != NULL); 1277 KASSERT(policy != NULL); 1278 1279 new = kmem_intr_zalloc(sizeof(*new), KM_NOSLEEP); 1280 if (new == NULL) { 1281 IPSECLOG(LOG_DEBUG, "No more memory.\n"); 1282 return ENOBUFS; 1283 } 1284 1285 if (IPSEC_PRIVILEGED_SO(so)) 1286 new->priv = 1; 1287 else 1288 new->priv = 0; 1289 1290 if ((new->sp_in = KEY_NEWSP()) == NULL) { 1291 ipsec_delpcbpolicy(new); 1292 return ENOBUFS; 1293 } 1294 new->sp_in->state = IPSEC_SPSTATE_ALIVE; 1295 new->sp_in->policy = IPSEC_POLICY_ENTRUST; 1296 1297 if ((new->sp_out = KEY_NEWSP()) == NULL) { 1298 KEY_FREESP(&new->sp_in); 1299 ipsec_delpcbpolicy(new); 1300 return ENOBUFS; 1301 } 1302 new->sp_out->state = IPSEC_SPSTATE_ALIVE; 1303 new->sp_out->policy = IPSEC_POLICY_ENTRUST; 1304 1305 *policy = new; 1306 1307 return 0; 1308 } 1309 1310 /* copy old ipsec policy into new */ 1311 int 1312 ipsec_copy_policy(const struct inpcbpolicy *old, struct inpcbpolicy *new) 1313 { 1314 struct secpolicy *sp; 1315 1316 sp = ipsec_deepcopy_policy(old->sp_in); 1317 if (sp) { 1318 KEY_FREESP(&new->sp_in); 1319 new->sp_in = sp; 1320 } else 1321 return ENOBUFS; 1322 1323 sp = ipsec_deepcopy_policy(old->sp_out); 1324 if (sp) { 1325 KEY_FREESP(&new->sp_out); 1326 new->sp_out = sp; 1327 } else 1328 return ENOBUFS; 1329 1330 new->priv = old->priv; 1331 1332 return 0; 1333 } 1334 1335 /* deep-copy a policy in PCB */ 1336 static struct secpolicy * 1337 ipsec_deepcopy_policy(const struct secpolicy *src) 1338 { 1339 struct ipsecrequest *newchain = NULL; 1340 const struct ipsecrequest *p; 1341 struct ipsecrequest **q; 1342 struct ipsecrequest *r; 1343 struct secpolicy *dst; 1344 1345 if (src == NULL) 1346 return NULL; 1347 dst = KEY_NEWSP(); 1348 if (dst == NULL) 1349 return NULL; 1350 1351 /* 1352 * deep-copy IPsec request chain. This is required since struct 1353 * ipsecrequest is not reference counted. 1354 */ 1355 q = &newchain; 1356 for (p = src->req; p; p = p->next) { 1357 *q = kmem_zalloc(sizeof(**q), KM_SLEEP); 1358 if (*q == NULL) 1359 goto fail; 1360 (*q)->next = NULL; 1361 1362 (*q)->saidx.proto = p->saidx.proto; 1363 (*q)->saidx.mode = p->saidx.mode; 1364 (*q)->level = p->level; 1365 (*q)->saidx.reqid = p->saidx.reqid; 1366 1367 memcpy(&(*q)->saidx.src, &p->saidx.src, sizeof((*q)->saidx.src)); 1368 memcpy(&(*q)->saidx.dst, &p->saidx.dst, sizeof((*q)->saidx.dst)); 1369 1370 (*q)->sav = NULL; 1371 (*q)->sp = dst; 1372 1373 q = &((*q)->next); 1374 } 1375 1376 dst->req = newchain; 1377 dst->state = src->state; 1378 dst->policy = src->policy; 1379 /* do not touch the refcnt fields */ 1380 1381 return dst; 1382 1383 fail: 1384 for (q = &newchain; *q; q = &r) { 1385 r = (*q)->next; 1386 kmem_free(*q, sizeof(**q)); 1387 } 1388 return NULL; 1389 } 1390 1391 /* set policy and ipsec request if present. */ 1392 static int 1393 ipsec_set_policy( 1394 struct secpolicy **policy, 1395 int optname, 1396 const void *request, 1397 size_t len, 1398 kauth_cred_t cred 1399 ) 1400 { 1401 const struct sadb_x_policy *xpl; 1402 struct secpolicy *newsp = NULL; 1403 int error; 1404 1405 KASSERT(!cpu_softintr_p()); 1406 1407 /* sanity check. */ 1408 if (policy == NULL || *policy == NULL || request == NULL) 1409 return EINVAL; 1410 if (len < sizeof(*xpl)) 1411 return EINVAL; 1412 xpl = (const struct sadb_x_policy *)request; 1413 1414 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DUMP)) { 1415 printf("%s: passed policy\n", __func__); 1416 kdebug_sadb_x_policy((const struct sadb_ext *)xpl); 1417 } 1418 1419 /* check policy type */ 1420 /* ipsec_set_policy() accepts IPSEC, ENTRUST and BYPASS. */ 1421 if (xpl->sadb_x_policy_type == IPSEC_POLICY_DISCARD 1422 || xpl->sadb_x_policy_type == IPSEC_POLICY_NONE) 1423 return EINVAL; 1424 1425 /* check privileged socket */ 1426 if (xpl->sadb_x_policy_type == IPSEC_POLICY_BYPASS) { 1427 error = kauth_authorize_network(cred, KAUTH_NETWORK_IPSEC, 1428 KAUTH_REQ_NETWORK_IPSEC_BYPASS, NULL, NULL, NULL); 1429 if (error) 1430 return (error); 1431 } 1432 1433 /* allocation new SP entry */ 1434 if ((newsp = key_msg2sp(xpl, len, &error)) == NULL) 1435 return error; 1436 1437 newsp->state = IPSEC_SPSTATE_ALIVE; 1438 1439 /* clear old SP and set new SP */ 1440 KEY_FREESP(policy); 1441 *policy = newsp; 1442 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DUMP)) { 1443 printf("%s: new policy\n", __func__); 1444 kdebug_secpolicy(newsp); 1445 } 1446 1447 return 0; 1448 } 1449 1450 static int 1451 ipsec_get_policy(struct secpolicy *policy, struct mbuf **mp) 1452 { 1453 1454 /* sanity check. */ 1455 if (policy == NULL || mp == NULL) 1456 return EINVAL; 1457 1458 *mp = key_sp2msg(policy); 1459 if (!*mp) { 1460 IPSECLOG(LOG_DEBUG, "No more memory.\n"); 1461 return ENOBUFS; 1462 } 1463 1464 (*mp)->m_type = MT_DATA; 1465 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DUMP)) { 1466 printf("%s:\n", __func__); 1467 kdebug_mbuf(*mp); 1468 } 1469 1470 return 0; 1471 } 1472 1473 int 1474 ipsec4_set_policy(struct inpcb *inp, int optname, const void *request, 1475 size_t len, kauth_cred_t cred) 1476 { 1477 const struct sadb_x_policy *xpl; 1478 struct secpolicy **policy; 1479 1480 KASSERT(!cpu_softintr_p()); 1481 1482 /* sanity check. */ 1483 if (inp == NULL || request == NULL) 1484 return EINVAL; 1485 if (len < sizeof(*xpl)) 1486 return EINVAL; 1487 xpl = (const struct sadb_x_policy *)request; 1488 1489 KASSERT(inp->inp_sp != NULL); 1490 1491 /* select direction */ 1492 switch (xpl->sadb_x_policy_dir) { 1493 case IPSEC_DIR_INBOUND: 1494 policy = &inp->inp_sp->sp_in; 1495 break; 1496 case IPSEC_DIR_OUTBOUND: 1497 policy = &inp->inp_sp->sp_out; 1498 break; 1499 default: 1500 IPSECLOG(LOG_ERR, "invalid direction=%u\n", 1501 xpl->sadb_x_policy_dir); 1502 return EINVAL; 1503 } 1504 1505 return ipsec_set_policy(policy, optname, request, len, cred); 1506 } 1507 1508 int 1509 ipsec4_get_policy(struct inpcb *inp, const void *request, size_t len, 1510 struct mbuf **mp) 1511 { 1512 const struct sadb_x_policy *xpl; 1513 struct secpolicy *policy; 1514 1515 /* sanity check. */ 1516 if (inp == NULL || request == NULL || mp == NULL) 1517 return EINVAL; 1518 KASSERT(inp->inp_sp != NULL); 1519 if (len < sizeof(*xpl)) 1520 return EINVAL; 1521 xpl = (const struct sadb_x_policy *)request; 1522 1523 /* select direction */ 1524 switch (xpl->sadb_x_policy_dir) { 1525 case IPSEC_DIR_INBOUND: 1526 policy = inp->inp_sp->sp_in; 1527 break; 1528 case IPSEC_DIR_OUTBOUND: 1529 policy = inp->inp_sp->sp_out; 1530 break; 1531 default: 1532 IPSECLOG(LOG_ERR, "invalid direction=%u\n", 1533 xpl->sadb_x_policy_dir); 1534 return EINVAL; 1535 } 1536 1537 return ipsec_get_policy(policy, mp); 1538 } 1539 1540 /* delete policy in PCB */ 1541 int 1542 ipsec4_delete_pcbpolicy(struct inpcb *inp) 1543 { 1544 1545 KASSERT(inp != NULL); 1546 1547 if (inp->inp_sp == NULL) 1548 return 0; 1549 1550 if (inp->inp_sp->sp_in != NULL) 1551 KEY_FREESP(&inp->inp_sp->sp_in); 1552 1553 if (inp->inp_sp->sp_out != NULL) 1554 KEY_FREESP(&inp->inp_sp->sp_out); 1555 1556 ipsec_invalpcbcache(inp->inp_sp, IPSEC_DIR_ANY); 1557 1558 ipsec_delpcbpolicy(inp->inp_sp); 1559 inp->inp_sp = NULL; 1560 1561 return 0; 1562 } 1563 1564 #ifdef INET6 1565 int 1566 ipsec6_set_policy(struct in6pcb *in6p, int optname, const void *request, 1567 size_t len, kauth_cred_t cred) 1568 { 1569 const struct sadb_x_policy *xpl; 1570 struct secpolicy **policy; 1571 1572 KASSERT(!cpu_softintr_p()); 1573 1574 /* sanity check. */ 1575 if (in6p == NULL || request == NULL) 1576 return EINVAL; 1577 if (len < sizeof(*xpl)) 1578 return EINVAL; 1579 xpl = (const struct sadb_x_policy *)request; 1580 1581 /* select direction */ 1582 switch (xpl->sadb_x_policy_dir) { 1583 case IPSEC_DIR_INBOUND: 1584 policy = &in6p->in6p_sp->sp_in; 1585 break; 1586 case IPSEC_DIR_OUTBOUND: 1587 policy = &in6p->in6p_sp->sp_out; 1588 break; 1589 default: 1590 IPSECLOG(LOG_ERR, "invalid direction=%u\n", 1591 xpl->sadb_x_policy_dir); 1592 return EINVAL; 1593 } 1594 1595 return ipsec_set_policy(policy, optname, request, len, cred); 1596 } 1597 1598 int 1599 ipsec6_get_policy(struct in6pcb *in6p, const void *request, size_t len, 1600 struct mbuf **mp) 1601 { 1602 const struct sadb_x_policy *xpl; 1603 struct secpolicy *policy; 1604 1605 /* sanity check. */ 1606 if (in6p == NULL || request == NULL || mp == NULL) 1607 return EINVAL; 1608 KASSERT(in6p->in6p_sp != NULL); 1609 if (len < sizeof(*xpl)) 1610 return EINVAL; 1611 xpl = (const struct sadb_x_policy *)request; 1612 1613 /* select direction */ 1614 switch (xpl->sadb_x_policy_dir) { 1615 case IPSEC_DIR_INBOUND: 1616 policy = in6p->in6p_sp->sp_in; 1617 break; 1618 case IPSEC_DIR_OUTBOUND: 1619 policy = in6p->in6p_sp->sp_out; 1620 break; 1621 default: 1622 IPSECLOG(LOG_ERR, "invalid direction=%u\n", 1623 xpl->sadb_x_policy_dir); 1624 return EINVAL; 1625 } 1626 1627 return ipsec_get_policy(policy, mp); 1628 } 1629 1630 int 1631 ipsec6_delete_pcbpolicy(struct in6pcb *in6p) 1632 { 1633 1634 KASSERT(in6p != NULL); 1635 1636 if (in6p->in6p_sp == NULL) 1637 return 0; 1638 1639 if (in6p->in6p_sp->sp_in != NULL) 1640 KEY_FREESP(&in6p->in6p_sp->sp_in); 1641 1642 if (in6p->in6p_sp->sp_out != NULL) 1643 KEY_FREESP(&in6p->in6p_sp->sp_out); 1644 1645 ipsec_invalpcbcache(in6p->in6p_sp, IPSEC_DIR_ANY); 1646 1647 ipsec_delpcbpolicy(in6p->in6p_sp); 1648 in6p->in6p_sp = NULL; 1649 1650 return 0; 1651 } 1652 #endif 1653 1654 /* 1655 * return current level. 1656 * Either IPSEC_LEVEL_USE or IPSEC_LEVEL_REQUIRE are always returned. 1657 */ 1658 u_int 1659 ipsec_get_reqlevel(const struct ipsecrequest *isr) 1660 { 1661 u_int level = 0; 1662 u_int esp_trans_deflev, esp_net_deflev; 1663 u_int ah_trans_deflev, ah_net_deflev; 1664 1665 KASSERT(isr != NULL); 1666 KASSERT(isr->sp != NULL); 1667 KASSERTMSG( 1668 isr->sp->spidx.src.sa.sa_family == isr->sp->spidx.dst.sa.sa_family, 1669 "af family mismatch, src %u, dst %u", 1670 isr->sp->spidx.src.sa.sa_family, isr->sp->spidx.dst.sa.sa_family); 1671 1672 /* XXX note that we have ipseclog() expanded here - code sync issue */ 1673 #define IPSEC_CHECK_DEFAULT(lev) \ 1674 (((lev) != IPSEC_LEVEL_USE && (lev) != IPSEC_LEVEL_REQUIRE \ 1675 && (lev) != IPSEC_LEVEL_UNIQUE) ? \ 1676 (ipsec_debug ? log(LOG_INFO, "fixed system default level " #lev \ 1677 ":%d->%d\n", (lev), IPSEC_LEVEL_REQUIRE) : (void)0), \ 1678 (lev) = IPSEC_LEVEL_REQUIRE, (lev) \ 1679 : (lev)) 1680 1681 /* set default level */ 1682 switch (((struct sockaddr *)&isr->sp->spidx.src)->sa_family) { 1683 #ifdef INET 1684 case AF_INET: 1685 esp_trans_deflev = IPSEC_CHECK_DEFAULT(ip4_esp_trans_deflev); 1686 esp_net_deflev = IPSEC_CHECK_DEFAULT(ip4_esp_net_deflev); 1687 ah_trans_deflev = IPSEC_CHECK_DEFAULT(ip4_ah_trans_deflev); 1688 ah_net_deflev = IPSEC_CHECK_DEFAULT(ip4_ah_net_deflev); 1689 break; 1690 #endif 1691 #ifdef INET6 1692 case AF_INET6: 1693 esp_trans_deflev = IPSEC_CHECK_DEFAULT(ip6_esp_trans_deflev); 1694 esp_net_deflev = IPSEC_CHECK_DEFAULT(ip6_esp_net_deflev); 1695 ah_trans_deflev = IPSEC_CHECK_DEFAULT(ip6_ah_trans_deflev); 1696 ah_net_deflev = IPSEC_CHECK_DEFAULT(ip6_ah_net_deflev); 1697 break; 1698 #endif /* INET6 */ 1699 default: 1700 panic("%s: unknown af %u", __func__, 1701 isr->sp->spidx.src.sa.sa_family); 1702 } 1703 1704 #undef IPSEC_CHECK_DEFAULT 1705 1706 /* set level */ 1707 switch (isr->level) { 1708 case IPSEC_LEVEL_DEFAULT: 1709 switch (isr->saidx.proto) { 1710 case IPPROTO_ESP: 1711 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) 1712 level = esp_net_deflev; 1713 else 1714 level = esp_trans_deflev; 1715 break; 1716 case IPPROTO_AH: 1717 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) 1718 level = ah_net_deflev; 1719 else 1720 level = ah_trans_deflev; 1721 break; 1722 case IPPROTO_IPCOMP: 1723 /* 1724 * we don't really care, as IPcomp document says that 1725 * we shouldn't compress small packets 1726 */ 1727 level = IPSEC_LEVEL_USE; 1728 break; 1729 default: 1730 panic("%s: Illegal protocol defined %u", __func__, 1731 isr->saidx.proto); 1732 } 1733 break; 1734 1735 case IPSEC_LEVEL_USE: 1736 case IPSEC_LEVEL_REQUIRE: 1737 level = isr->level; 1738 break; 1739 case IPSEC_LEVEL_UNIQUE: 1740 level = IPSEC_LEVEL_REQUIRE; 1741 break; 1742 1743 default: 1744 panic("%s: Illegal IPsec level %u", __func__, isr->level); 1745 } 1746 1747 return level; 1748 } 1749 1750 /* 1751 * Check security policy requirements against the actual 1752 * packet contents. Return one if the packet should be 1753 * reject as "invalid"; otherwiser return zero to have the 1754 * packet treated as "valid". 1755 * 1756 * OUT: 1757 * 0: valid 1758 * 1: invalid 1759 */ 1760 int 1761 ipsec_in_reject(const struct secpolicy *sp, const struct mbuf *m) 1762 { 1763 struct ipsecrequest *isr; 1764 int need_auth; 1765 1766 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DATA)) { 1767 printf("%s: using SP\n", __func__); 1768 kdebug_secpolicy(sp); 1769 } 1770 1771 /* check policy */ 1772 switch (sp->policy) { 1773 case IPSEC_POLICY_DISCARD: 1774 return 1; 1775 case IPSEC_POLICY_BYPASS: 1776 case IPSEC_POLICY_NONE: 1777 return 0; 1778 } 1779 1780 KASSERTMSG(sp->policy == IPSEC_POLICY_IPSEC, 1781 "invalid policy %u", sp->policy); 1782 1783 /* XXX should compare policy against ipsec header history */ 1784 1785 need_auth = 0; 1786 for (isr = sp->req; isr != NULL; isr = isr->next) { 1787 if (ipsec_get_reqlevel(isr) != IPSEC_LEVEL_REQUIRE) 1788 continue; 1789 switch (isr->saidx.proto) { 1790 case IPPROTO_ESP: 1791 if ((m->m_flags & M_DECRYPTED) == 0) { 1792 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 1793 "ESP m_flags:%x\n", m->m_flags); 1794 return 1; 1795 } 1796 1797 if (!need_auth && 1798 isr->sav != NULL && 1799 isr->sav->tdb_authalgxform != NULL && 1800 (m->m_flags & M_AUTHIPDGM) == 0) { 1801 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 1802 "ESP/AH m_flags:%x\n", m->m_flags); 1803 return 1; 1804 } 1805 break; 1806 case IPPROTO_AH: 1807 need_auth = 1; 1808 if ((m->m_flags & M_AUTHIPHDR) == 0) { 1809 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DUMP, 1810 "AH m_flags:%x\n", m->m_flags); 1811 return 1; 1812 } 1813 break; 1814 case IPPROTO_IPCOMP: 1815 /* 1816 * we don't really care, as IPcomp document 1817 * says that we shouldn't compress small 1818 * packets, IPComp policy should always be 1819 * treated as being in "use" level. 1820 */ 1821 break; 1822 } 1823 } 1824 return 0; /* valid */ 1825 } 1826 1827 /* 1828 * Check AH/ESP integrity. 1829 * This function is called from tcp_input(), udp_input(), 1830 * and {ah,esp}4_input for tunnel mode 1831 */ 1832 int 1833 ipsec4_in_reject(struct mbuf *m, struct inpcb *inp) 1834 { 1835 struct secpolicy *sp; 1836 int error; 1837 int result; 1838 1839 KASSERT(m != NULL); 1840 1841 /* get SP for this packet. 1842 * When we are called from ip_forward(), we call 1843 * ipsec_getpolicybyaddr() with IP_FORWARDING flag. 1844 */ 1845 if (inp == NULL) 1846 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND, IP_FORWARDING, &error); 1847 else 1848 sp = ipsec_getpolicybysock(m, IPSEC_DIR_INBOUND, 1849 (struct inpcb_hdr *)inp, &error); 1850 1851 if (sp != NULL) { 1852 result = ipsec_in_reject(sp, m); 1853 if (result) 1854 IPSEC_STATINC(IPSEC_STAT_IN_POLVIO); 1855 KEY_FREESP(&sp); 1856 } else { 1857 result = 0; /* XXX should be panic ? 1858 * -> No, there may be error. */ 1859 } 1860 return result; 1861 } 1862 1863 1864 #ifdef INET6 1865 /* 1866 * Check AH/ESP integrity. 1867 * This function is called from tcp6_input(), udp6_input(), 1868 * and {ah,esp}6_input for tunnel mode 1869 */ 1870 int 1871 ipsec6_in_reject(struct mbuf *m, struct in6pcb *in6p) 1872 { 1873 struct secpolicy *sp = NULL; 1874 int error; 1875 int result; 1876 1877 KASSERT(m != NULL); 1878 1879 /* get SP for this packet. 1880 * When we are called from ip_forward(), we call 1881 * ipsec_getpolicybyaddr() with IP_FORWARDING flag. 1882 */ 1883 if (in6p == NULL) 1884 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND, IP_FORWARDING, &error); 1885 else 1886 sp = ipsec_getpolicybysock(m, IPSEC_DIR_INBOUND, 1887 (struct inpcb_hdr *)in6p, 1888 &error); 1889 1890 if (sp != NULL) { 1891 result = ipsec_in_reject(sp, m); 1892 if (result) 1893 IPSEC_STATINC(IPSEC_STAT_IN_POLVIO); 1894 KEY_FREESP(&sp); 1895 } else { 1896 result = 0; 1897 } 1898 return result; 1899 } 1900 #endif 1901 1902 /* 1903 * compute the byte size to be occupied by IPsec header. 1904 * in case it is tunneled, it includes the size of outer IP header. 1905 * NOTE: SP passed is free in this function. 1906 */ 1907 static size_t 1908 ipsec_hdrsiz(const struct secpolicy *sp) 1909 { 1910 const struct ipsecrequest *isr; 1911 size_t siz; 1912 1913 if (KEYDEBUG_ON(KEYDEBUG_IPSEC_DATA)) { 1914 printf("%s: using SP\n", __func__); 1915 kdebug_secpolicy(sp); 1916 } 1917 1918 switch (sp->policy) { 1919 case IPSEC_POLICY_DISCARD: 1920 case IPSEC_POLICY_BYPASS: 1921 case IPSEC_POLICY_NONE: 1922 return 0; 1923 } 1924 1925 KASSERTMSG(sp->policy == IPSEC_POLICY_IPSEC, 1926 "invalid policy %u", sp->policy); 1927 1928 siz = 0; 1929 for (isr = sp->req; isr != NULL; isr = isr->next) { 1930 size_t clen = 0; 1931 1932 switch (isr->saidx.proto) { 1933 case IPPROTO_ESP: 1934 clen = esp_hdrsiz(isr->sav); 1935 break; 1936 case IPPROTO_AH: 1937 clen = ah_hdrsiz(isr->sav); 1938 break; 1939 case IPPROTO_IPCOMP: 1940 clen = sizeof(struct ipcomp); 1941 break; 1942 } 1943 1944 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) { 1945 switch (isr->saidx.dst.sa.sa_family) { 1946 case AF_INET: 1947 clen += sizeof(struct ip); 1948 break; 1949 #ifdef INET6 1950 case AF_INET6: 1951 clen += sizeof(struct ip6_hdr); 1952 break; 1953 #endif 1954 default: 1955 IPSECLOG(LOG_ERR, "unknown AF %d in " 1956 "IPsec tunnel SA\n", 1957 ((const struct sockaddr *)&isr->saidx.dst) 1958 ->sa_family); 1959 break; 1960 } 1961 } 1962 siz += clen; 1963 } 1964 1965 return siz; 1966 } 1967 1968 /* This function is called from ip_forward() and ipsec4_hdrsize_tcp(). */ 1969 size_t 1970 ipsec4_hdrsiz(struct mbuf *m, u_int dir, struct inpcb *inp) 1971 { 1972 struct secpolicy *sp; 1973 int error; 1974 size_t size; 1975 1976 KASSERT(m != NULL); 1977 KASSERTMSG(inp == NULL || inp->inp_socket != NULL, "socket w/o inpcb"); 1978 1979 /* get SP for this packet. 1980 * When we are called from ip_forward(), we call 1981 * ipsec_getpolicybyaddr() with IP_FORWARDING flag. 1982 */ 1983 if (inp == NULL) 1984 sp = ipsec_getpolicybyaddr(m, dir, IP_FORWARDING, &error); 1985 else 1986 sp = ipsec_getpolicybysock(m, dir, 1987 (struct inpcb_hdr *)inp, &error); 1988 1989 if (sp != NULL) { 1990 size = ipsec_hdrsiz(sp); 1991 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DATA, "size:%lu.\n", 1992 (unsigned long)size); 1993 1994 KEY_FREESP(&sp); 1995 } else { 1996 size = 0; /* XXX should be panic ? */ 1997 } 1998 return size; 1999 } 2000 2001 #ifdef INET6 2002 /* This function is called from ipsec6_hdrsize_tcp(), 2003 * and maybe from ip6_forward.() 2004 */ 2005 size_t 2006 ipsec6_hdrsiz(struct mbuf *m, u_int dir, struct in6pcb *in6p) 2007 { 2008 struct secpolicy *sp; 2009 int error; 2010 size_t size; 2011 2012 KASSERT(m != NULL); 2013 KASSERTMSG(in6p == NULL || in6p->in6p_socket != NULL, 2014 "socket w/o inpcb"); 2015 2016 /* get SP for this packet */ 2017 /* XXX Is it right to call with IP_FORWARDING. */ 2018 if (in6p == NULL) 2019 sp = ipsec_getpolicybyaddr(m, dir, IP_FORWARDING, &error); 2020 else 2021 sp = ipsec_getpolicybysock(m, dir, 2022 (struct inpcb_hdr *)in6p, 2023 &error); 2024 2025 if (sp == NULL) 2026 return 0; 2027 size = ipsec_hdrsiz(sp); 2028 KEYDEBUG_PRINTF(KEYDEBUG_IPSEC_DATA, "size:%zu.\n", size); 2029 KEY_FREESP(&sp); 2030 2031 return size; 2032 } 2033 #endif /*INET6*/ 2034 2035 /* 2036 * Check the variable replay window. 2037 * ipsec_chkreplay() performs replay check before ICV verification. 2038 * ipsec_updatereplay() updates replay bitmap. This must be called after 2039 * ICV verification (it also performs replay check, which is usually done 2040 * beforehand). 2041 * 0 (zero) is returned if packet disallowed, 1 if packet permitted. 2042 * 2043 * based on RFC 2401. 2044 */ 2045 int 2046 ipsec_chkreplay(u_int32_t seq, const struct secasvar *sav) 2047 { 2048 const struct secreplay *replay; 2049 u_int32_t diff; 2050 int fr; 2051 u_int32_t wsizeb; /* constant: bits of window size */ 2052 int frlast; /* constant: last frame */ 2053 2054 IPSEC_SPLASSERT_SOFTNET(__func__); 2055 2056 KASSERT(sav != NULL); 2057 KASSERT(sav->replay != NULL); 2058 2059 replay = sav->replay; 2060 2061 if (replay->wsize == 0) 2062 return 1; /* no need to check replay. */ 2063 2064 /* constant */ 2065 frlast = replay->wsize - 1; 2066 wsizeb = replay->wsize << 3; 2067 2068 /* sequence number of 0 is invalid */ 2069 if (seq == 0) 2070 return 0; 2071 2072 /* first time is always okay */ 2073 if (replay->count == 0) 2074 return 1; 2075 2076 if (seq > replay->lastseq) { 2077 /* larger sequences are okay */ 2078 return 1; 2079 } else { 2080 /* seq is equal or less than lastseq. */ 2081 diff = replay->lastseq - seq; 2082 2083 /* over range to check, i.e. too old or wrapped */ 2084 if (diff >= wsizeb) 2085 return 0; 2086 2087 fr = frlast - diff / 8; 2088 2089 /* this packet already seen ? */ 2090 if ((replay->bitmap)[fr] & (1 << (diff % 8))) 2091 return 0; 2092 2093 /* out of order but good */ 2094 return 1; 2095 } 2096 } 2097 2098 /* 2099 * check replay counter whether to update or not. 2100 * OUT: 0: OK 2101 * 1: NG 2102 */ 2103 int 2104 ipsec_updatereplay(u_int32_t seq, const struct secasvar *sav) 2105 { 2106 struct secreplay *replay; 2107 u_int32_t diff; 2108 int fr; 2109 u_int32_t wsizeb; /* constant: bits of window size */ 2110 int frlast; /* constant: last frame */ 2111 char buf[INET6_ADDRSTRLEN]; 2112 2113 IPSEC_SPLASSERT_SOFTNET(__func__); 2114 2115 KASSERT(sav != NULL); 2116 KASSERT(sav->replay != NULL); 2117 2118 replay = sav->replay; 2119 2120 if (replay->wsize == 0) 2121 goto ok; /* no need to check replay. */ 2122 2123 /* constant */ 2124 frlast = replay->wsize - 1; 2125 wsizeb = replay->wsize << 3; 2126 2127 /* sequence number of 0 is invalid */ 2128 if (seq == 0) 2129 return 1; 2130 2131 /* first time */ 2132 if (replay->count == 0) { 2133 replay->lastseq = seq; 2134 memset(replay->bitmap, 0, replay->wsize); 2135 (replay->bitmap)[frlast] = 1; 2136 goto ok; 2137 } 2138 2139 if (seq > replay->lastseq) { 2140 /* seq is larger than lastseq. */ 2141 diff = seq - replay->lastseq; 2142 2143 /* new larger sequence number */ 2144 if (diff < wsizeb) { 2145 /* In window */ 2146 /* set bit for this packet */ 2147 vshiftl(replay->bitmap, diff, replay->wsize); 2148 (replay->bitmap)[frlast] |= 1; 2149 } else { 2150 /* this packet has a "way larger" */ 2151 memset(replay->bitmap, 0, replay->wsize); 2152 (replay->bitmap)[frlast] = 1; 2153 } 2154 replay->lastseq = seq; 2155 2156 /* larger is good */ 2157 } else { 2158 /* seq is equal or less than lastseq. */ 2159 diff = replay->lastseq - seq; 2160 2161 /* over range to check, i.e. too old or wrapped */ 2162 if (diff >= wsizeb) 2163 return 1; 2164 2165 fr = frlast - diff / 8; 2166 2167 /* this packet already seen ? */ 2168 if ((replay->bitmap)[fr] & (1 << (diff % 8))) 2169 return 1; 2170 2171 /* mark as seen */ 2172 (replay->bitmap)[fr] |= (1 << (diff % 8)); 2173 2174 /* out of order but good */ 2175 } 2176 2177 ok: 2178 if (replay->count == ~0) { 2179 2180 /* set overflow flag */ 2181 replay->overflow++; 2182 2183 /* don't increment, no more packets accepted */ 2184 if ((sav->flags & SADB_X_EXT_CYCSEQ) == 0) 2185 return 1; 2186 2187 IPSECLOG(LOG_WARNING, "replay counter made %d cycle. %s\n", 2188 replay->overflow, ipsec_logsastr(sav, buf, sizeof(buf))); 2189 } 2190 2191 replay->count++; 2192 2193 return 0; 2194 } 2195 2196 /* 2197 * shift variable length bunffer to left. 2198 * IN: bitmap: pointer to the buffer 2199 * nbit: the number of to shift. 2200 * wsize: buffer size (bytes). 2201 */ 2202 static void 2203 vshiftl(unsigned char *bitmap, int nbit, int wsize) 2204 { 2205 int s, j, i; 2206 unsigned char over; 2207 2208 for (j = 0; j < nbit; j += 8) { 2209 s = (nbit - j < 8) ? (nbit - j): 8; 2210 bitmap[0] <<= s; 2211 for (i = 1; i < wsize; i++) { 2212 over = (bitmap[i] >> (8 - s)); 2213 bitmap[i] <<= s; 2214 bitmap[i-1] |= over; 2215 } 2216 } 2217 2218 return; 2219 } 2220 2221 /* Return a printable string for the address. */ 2222 const char * 2223 ipsec_address(const union sockaddr_union *sa, char *buf, size_t size) 2224 { 2225 switch (sa->sa.sa_family) { 2226 #if INET 2227 case AF_INET: 2228 in_print(buf, size, &sa->sin.sin_addr); 2229 return buf; 2230 #endif /* INET */ 2231 2232 #if INET6 2233 case AF_INET6: 2234 in6_print(buf, size, &sa->sin6.sin6_addr); 2235 return buf; 2236 #endif /* INET6 */ 2237 2238 default: 2239 return "(unknown address family)"; 2240 } 2241 } 2242 2243 const char * 2244 ipsec_logsastr(const struct secasvar *sav, char *buf, size_t size) 2245 { 2246 const struct secasindex *saidx = &sav->sah->saidx; 2247 char sbuf[IPSEC_ADDRSTRLEN], dbuf[IPSEC_ADDRSTRLEN]; 2248 2249 KASSERTMSG(saidx->src.sa.sa_family == saidx->dst.sa.sa_family, 2250 "af family mismatch, src %u, dst %u", 2251 saidx->src.sa.sa_family, saidx->dst.sa.sa_family); 2252 2253 snprintf(buf, size, "SA(SPI=%u src=%s dst=%s)", 2254 (u_int32_t)ntohl(sav->spi), 2255 ipsec_address(&saidx->src, sbuf, sizeof(sbuf)), 2256 ipsec_address(&saidx->dst, dbuf, sizeof(dbuf))); 2257 2258 return buf; 2259 } 2260 2261 void 2262 ipsec_dumpmbuf(struct mbuf *m) 2263 { 2264 int totlen; 2265 int i; 2266 u_char *p; 2267 2268 totlen = 0; 2269 printf("---\n"); 2270 while (m) { 2271 p = mtod(m, u_char *); 2272 for (i = 0; i < m->m_len; i++) { 2273 printf("%02x ", p[i]); 2274 totlen++; 2275 if (totlen % 16 == 0) 2276 printf("\n"); 2277 } 2278 m = m->m_next; 2279 } 2280 if (totlen % 16 != 0) 2281 printf("\n"); 2282 printf("---\n"); 2283 } 2284 2285 #ifdef INET6 2286 struct secpolicy * 2287 ipsec6_check_policy(struct mbuf *m, struct in6pcb *in6p, 2288 int flags, int *needipsecp, int *errorp) 2289 { 2290 struct secpolicy *sp = NULL; 2291 int s; 2292 int error = 0; 2293 int needipsec = 0; 2294 2295 if (!ipsec_outdone(m)) { 2296 s = splsoftnet(); 2297 if (in6p != NULL && 2298 IPSEC_PCB_SKIP_IPSEC(in6p->in6p_sp, IPSEC_DIR_OUTBOUND)) { 2299 splx(s); 2300 goto skippolicycheck; 2301 } 2302 sp = ipsec6_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags, &error,in6p); 2303 2304 /* 2305 * There are four return cases: 2306 * sp != NULL apply IPsec policy 2307 * sp == NULL, error == 0 no IPsec handling needed 2308 * sp == NULL, error == -EINVAL discard packet w/o error 2309 * sp == NULL, error != 0 discard packet, report error 2310 */ 2311 2312 splx(s); 2313 if (sp == NULL) { 2314 /* 2315 * Caller must check the error return to see if it needs to discard 2316 * the packet. 2317 */ 2318 needipsec = 0; 2319 } else { 2320 needipsec = 1; 2321 } 2322 } 2323 skippolicycheck:; 2324 2325 *errorp = error; 2326 *needipsecp = needipsec; 2327 return sp; 2328 } 2329 2330 int 2331 ipsec6_input(struct mbuf *m) 2332 { 2333 struct m_tag *mtag; 2334 struct tdb_ident *tdbi; 2335 struct secpolicy *sp; 2336 int s, error; 2337 2338 /* 2339 * Check if the packet has already had IPsec 2340 * processing done. If so, then just pass it 2341 * along. This tag gets set during AH, ESP, 2342 * etc. input handling, before the packet is 2343 * returned to the ip input queue for delivery. 2344 */ 2345 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, 2346 NULL); 2347 s = splsoftnet(); 2348 if (mtag != NULL) { 2349 tdbi = (struct tdb_ident *)(mtag + 1); 2350 sp = ipsec_getpolicy(tdbi, 2351 IPSEC_DIR_INBOUND); 2352 } else { 2353 sp = ipsec_getpolicybyaddr(m, 2354 IPSEC_DIR_INBOUND, IP_FORWARDING, 2355 &error); 2356 } 2357 if (sp != NULL) { 2358 /* 2359 * Check security policy against packet 2360 * attributes. 2361 */ 2362 error = ipsec_in_reject(sp, m); 2363 KEY_FREESP(&sp); 2364 } else { 2365 /* XXX error stat??? */ 2366 error = EINVAL; 2367 IPSECLOG(LOG_DEBUG, "no SP, packet discarded\n");/*XXX*/ 2368 } 2369 splx(s); 2370 2371 return error; 2372 } 2373 #endif /* INET6 */ 2374 2375 2376 2377 /* XXX this stuff doesn't belong here... */ 2378 2379 static struct xformsw *xforms = NULL; 2380 2381 /* 2382 * Register a transform; typically at system startup. 2383 */ 2384 void 2385 xform_register(struct xformsw *xsp) 2386 { 2387 xsp->xf_next = xforms; 2388 xforms = xsp; 2389 } 2390 2391 /* 2392 * Initialize transform support in an sav. 2393 */ 2394 int 2395 xform_init(struct secasvar *sav, int xftype) 2396 { 2397 struct xformsw *xsp; 2398 2399 if (sav->tdb_xform != NULL) /* previously initialized */ 2400 return 0; 2401 for (xsp = xforms; xsp; xsp = xsp->xf_next) 2402 if (xsp->xf_type == xftype) 2403 return (*xsp->xf_init)(sav, xsp); 2404 2405 IPSECLOG(LOG_DEBUG, "no match for xform type %d\n", xftype); 2406 return EINVAL; 2407 } 2408 2409 void 2410 nat_t_ports_get(struct mbuf *m, u_int16_t *dport, u_int16_t *sport) { 2411 struct m_tag *tag; 2412 2413 if ((tag = m_tag_find(m, PACKET_TAG_IPSEC_NAT_T_PORTS, NULL))) { 2414 *sport = ((u_int16_t *)(tag + 1))[0]; 2415 *dport = ((u_int16_t *)(tag + 1))[1]; 2416 } else 2417 *sport = *dport = 0; 2418 } 2419 2420 /* 2421 * XXXJRT This should be done as a protosw init call. 2422 */ 2423 void 2424 ipsec_attach(void) 2425 { 2426 2427 ipsecstat_percpu = percpu_alloc(sizeof(uint64_t) * IPSEC_NSTATS); 2428 2429 sysctl_net_inet_ipsec_setup(NULL); 2430 #ifdef INET6 2431 sysctl_net_inet6_ipsec6_setup(NULL); 2432 #endif 2433 2434 ah_attach(); 2435 esp_attach(); 2436 ipcomp_attach(); 2437 ipe4_attach(); 2438 #ifdef TCP_SIGNATURE 2439 tcpsignature_attach(); 2440 #endif 2441 } 2442
Indexes created Tue Sep 23 07:09:52 GMT 2025