Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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sys/netipsec/ipsec.c
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1 /* $FreeBSD$ */ 2 /* $KAME: ipsec.c,v 1.103 2001/05/24 07:14:18 sakane Exp $ */ 3 4 /*- 5 * SPDX-License-Identifier: BSD-3-Clause 6 * 7 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 8 * All rights reserved. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the project nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 /* 36 * IPsec controller part. 37 */ 38 39 #include "opt_inet.h" 40 #include "opt_inet6.h" 41 #include "opt_ipsec.h" 42 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/malloc.h> 46 #include <sys/mbuf.h> 47 #include <sys/domain.h> 48 #include <sys/priv.h> 49 #include <sys/protosw.h> 50 #include <sys/socket.h> 51 #include <sys/socketvar.h> 52 #include <sys/errno.h> 53 #include <sys/hhook.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 60 #include <net/if.h> 61 #include <net/if_enc.h> 62 #include <net/if_var.h> 63 #include <net/vnet.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 75 #include <netinet/ip6.h> 76 #ifdef INET6 77 #include <netinet6/ip6_var.h> 78 #endif 79 #include <netinet/in_pcb.h> 80 #ifdef INET6 81 #include <netinet/icmp6.h> 82 #endif 83 84 #include <sys/types.h> 85 #include <netipsec/ipsec.h> 86 #ifdef INET6 87 #include <netipsec/ipsec6.h> 88 #endif 89 #include <netipsec/ah_var.h> 90 #include <netipsec/esp_var.h> 91 #include <netipsec/ipcomp.h> /*XXX*/ 92 #include <netipsec/ipcomp_var.h> 93 #include <netipsec/ipsec_support.h> 94 95 #include <netipsec/key.h> 96 #include <netipsec/keydb.h> 97 #include <netipsec/key_debug.h> 98 99 #include <netipsec/xform.h> 100 101 #include <machine/in_cksum.h> 102 103 #include <opencrypto/cryptodev.h> 104 105 /* NB: name changed so netstat doesn't use it. */ 106 VNET_PCPUSTAT_DEFINE(struct ipsecstat, ipsec4stat); 107 VNET_PCPUSTAT_SYSINIT(ipsec4stat); 108 109 #ifdef VIMAGE 110 VNET_PCPUSTAT_SYSUNINIT(ipsec4stat); 111 #endif /* VIMAGE */ 112 113 /* DF bit on encap. 0: clear 1: set 2: copy */ 114 VNET_DEFINE(int, ip4_ipsec_dfbit) = 0; 115 VNET_DEFINE(int, ip4_ipsec_min_pmtu) = 576; 116 VNET_DEFINE(int, ip4_esp_trans_deflev) = IPSEC_LEVEL_USE; 117 VNET_DEFINE(int, ip4_esp_net_deflev) = IPSEC_LEVEL_USE; 118 VNET_DEFINE(int, ip4_ah_trans_deflev) = IPSEC_LEVEL_USE; 119 VNET_DEFINE(int, ip4_ah_net_deflev) = IPSEC_LEVEL_USE; 120 /* ECN ignore(-1)/forbidden(0)/allowed(1) */ 121 VNET_DEFINE(int, ip4_ipsec_ecn) = 0; 122 123 VNET_DEFINE_STATIC(int, ip4_filtertunnel) = 0; 124 #define V_ip4_filtertunnel VNET(ip4_filtertunnel) 125 VNET_DEFINE_STATIC(int, check_policy_history) = 0; 126 #define V_check_policy_history VNET(check_policy_history) 127 VNET_DEFINE_STATIC(struct secpolicy *, def_policy) = NULL; 128 #define V_def_policy VNET(def_policy) 129 static int 130 sysctl_def_policy(SYSCTL_HANDLER_ARGS) 131 { 132 int error, value; 133 134 value = V_def_policy->policy; 135 error = sysctl_handle_int(oidp, &value, 0, req); 136 if (error == 0) { 137 if (value != IPSEC_POLICY_DISCARD && 138 value != IPSEC_POLICY_NONE) 139 return (EINVAL); 140 V_def_policy->policy = value; 141 } 142 return (error); 143 } 144 145 /* 146 * Crypto support requirements: 147 * 148 * 1 require hardware support 149 * -1 require software support 150 * 0 take anything 151 */ 152 VNET_DEFINE(int, crypto_support) = CRYPTOCAP_F_HARDWARE | CRYPTOCAP_F_SOFTWARE; 153 154 /* 155 * Use asynchronous mode to parallelize crypto jobs: 156 * 157 * 0 - disabled 158 * 1 - enabled 159 */ 160 VNET_DEFINE(int, async_crypto) = 0; 161 162 /* 163 * TCP/UDP checksum handling policy for transport mode NAT-T (RFC3948) 164 * 165 * 0 - auto: incrementally recompute, when checksum delta is known; 166 * if checksum delta isn't known, reset checksum to zero for UDP, 167 * and mark csum_flags as valid for TCP. 168 * 1 - fully recompute TCP/UDP checksum. 169 */ 170 VNET_DEFINE(int, natt_cksum_policy) = 0; 171 172 FEATURE(ipsec, "Internet Protocol Security (IPsec)"); 173 FEATURE(ipsec_natt, "UDP Encapsulation of IPsec ESP Packets ('NAT-T')"); 174 175 SYSCTL_DECL(_net_inet_ipsec); 176 177 /* net.inet.ipsec */ 178 SYSCTL_PROC(_net_inet_ipsec, IPSECCTL_DEF_POLICY, def_policy, 179 CTLTYPE_INT | CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 180 0, 0, sysctl_def_policy, "I", 181 "IPsec default policy."); 182 SYSCTL_INT(_net_inet_ipsec, IPSECCTL_DEF_ESP_TRANSLEV, esp_trans_deflev, 183 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip4_esp_trans_deflev), 0, 184 "Default ESP transport mode level"); 185 SYSCTL_INT(_net_inet_ipsec, IPSECCTL_DEF_ESP_NETLEV, esp_net_deflev, 186 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip4_esp_net_deflev), 0, 187 "Default ESP tunnel mode level."); 188 SYSCTL_INT(_net_inet_ipsec, IPSECCTL_DEF_AH_TRANSLEV, ah_trans_deflev, 189 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip4_ah_trans_deflev), 0, 190 "AH transfer mode default level."); 191 SYSCTL_INT(_net_inet_ipsec, IPSECCTL_DEF_AH_NETLEV, ah_net_deflev, 192 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip4_ah_net_deflev), 0, 193 "AH tunnel mode default level."); 194 SYSCTL_INT(_net_inet_ipsec, IPSECCTL_AH_CLEARTOS, ah_cleartos, 195 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ah_cleartos), 0, 196 "If set, clear type-of-service field when doing AH computation."); 197 SYSCTL_INT(_net_inet_ipsec, IPSECCTL_DFBIT, dfbit, 198 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip4_ipsec_dfbit), 0, 199 "Do not fragment bit on encap."); 200 SYSCTL_INT(_net_inet_ipsec, IPSECCTL_MIN_PMTU, min_pmtu, 201 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip4_ipsec_min_pmtu), 0, 202 "Lowest acceptable PMTU value."); 203 SYSCTL_INT(_net_inet_ipsec, IPSECCTL_ECN, ecn, 204 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip4_ipsec_ecn), 0, 205 "Explicit Congestion Notification handling."); 206 SYSCTL_INT(_net_inet_ipsec, OID_AUTO, crypto_support, 207 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(crypto_support), 0, 208 "Crypto driver selection."); 209 SYSCTL_INT(_net_inet_ipsec, OID_AUTO, async_crypto, 210 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(async_crypto), 0, 211 "Use asynchronous mode to parallelize crypto jobs."); 212 SYSCTL_INT(_net_inet_ipsec, OID_AUTO, check_policy_history, 213 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(check_policy_history), 0, 214 "Use strict check of inbound packets to security policy compliance."); 215 SYSCTL_INT(_net_inet_ipsec, OID_AUTO, natt_cksum_policy, 216 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(natt_cksum_policy), 0, 217 "Method to fix TCP/UDP checksum for transport mode IPsec after NAT."); 218 SYSCTL_INT(_net_inet_ipsec, OID_AUTO, filtertunnel, 219 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip4_filtertunnel), 0, 220 "If set, filter packets from an IPsec tunnel."); 221 SYSCTL_VNET_PCPUSTAT(_net_inet_ipsec, OID_AUTO, ipsecstats, struct ipsecstat, 222 ipsec4stat, "IPsec IPv4 statistics."); 223 224 #ifdef REGRESSION 225 /* 226 * When set to 1, IPsec will send packets with the same sequence number. 227 * This allows to verify if the other side has proper replay attacks detection. 228 */ 229 VNET_DEFINE(int, ipsec_replay) = 0; 230 SYSCTL_INT(_net_inet_ipsec, OID_AUTO, test_replay, 231 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ipsec_replay), 0, 232 "Emulate replay attack"); 233 /* 234 * When set 1, IPsec will send packets with corrupted HMAC. 235 * This allows to verify if the other side properly detects modified packets. 236 */ 237 VNET_DEFINE(int, ipsec_integrity) = 0; 238 SYSCTL_INT(_net_inet_ipsec, OID_AUTO, test_integrity, 239 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ipsec_integrity), 0, 240 "Emulate man-in-the-middle attack"); 241 #endif 242 243 #ifdef INET6 244 VNET_PCPUSTAT_DEFINE(struct ipsecstat, ipsec6stat); 245 VNET_PCPUSTAT_SYSINIT(ipsec6stat); 246 247 #ifdef VIMAGE 248 VNET_PCPUSTAT_SYSUNINIT(ipsec6stat); 249 #endif /* VIMAGE */ 250 251 VNET_DEFINE(int, ip6_esp_trans_deflev) = IPSEC_LEVEL_USE; 252 VNET_DEFINE(int, ip6_esp_net_deflev) = IPSEC_LEVEL_USE; 253 VNET_DEFINE(int, ip6_ah_trans_deflev) = IPSEC_LEVEL_USE; 254 VNET_DEFINE(int, ip6_ah_net_deflev) = IPSEC_LEVEL_USE; 255 VNET_DEFINE(int, ip6_ipsec_ecn) = 0; /* ECN ignore(-1)/forbidden(0)/allowed(1) */ 256 257 VNET_DEFINE_STATIC(int, ip6_filtertunnel) = 0; 258 #define V_ip6_filtertunnel VNET(ip6_filtertunnel) 259 260 SYSCTL_DECL(_net_inet6_ipsec6); 261 262 /* net.inet6.ipsec6 */ 263 SYSCTL_PROC(_net_inet6_ipsec6, IPSECCTL_DEF_POLICY, def_policy, 264 CTLTYPE_INT | CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 265 0, 0, sysctl_def_policy, "I", 266 "IPsec default policy."); 267 SYSCTL_INT(_net_inet6_ipsec6, IPSECCTL_DEF_ESP_TRANSLEV, esp_trans_deflev, 268 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip6_esp_trans_deflev), 0, 269 "Default ESP transport mode level."); 270 SYSCTL_INT(_net_inet6_ipsec6, IPSECCTL_DEF_ESP_NETLEV, esp_net_deflev, 271 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip6_esp_net_deflev), 0, 272 "Default ESP tunnel mode level."); 273 SYSCTL_INT(_net_inet6_ipsec6, IPSECCTL_DEF_AH_TRANSLEV, ah_trans_deflev, 274 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip6_ah_trans_deflev), 0, 275 "AH transfer mode default level."); 276 SYSCTL_INT(_net_inet6_ipsec6, IPSECCTL_DEF_AH_NETLEV, ah_net_deflev, 277 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip6_ah_net_deflev), 0, 278 "AH tunnel mode default level."); 279 SYSCTL_INT(_net_inet6_ipsec6, IPSECCTL_ECN, ecn, 280 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip6_ipsec_ecn), 0, 281 "Explicit Congestion Notification handling."); 282 SYSCTL_INT(_net_inet6_ipsec6, OID_AUTO, filtertunnel, 283 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip6_filtertunnel), 0, 284 "If set, filter packets from an IPsec tunnel."); 285 SYSCTL_VNET_PCPUSTAT(_net_inet6_ipsec6, IPSECCTL_STATS, ipsecstats, 286 struct ipsecstat, ipsec6stat, "IPsec IPv6 statistics."); 287 #endif /* INET6 */ 288 289 static int ipsec_in_reject(struct secpolicy *, struct inpcb *, 290 const struct mbuf *); 291 292 #ifdef INET 293 static void ipsec4_get_ulp(const struct mbuf *, struct secpolicyindex *, int); 294 static void ipsec4_setspidx_ipaddr(const struct mbuf *, 295 struct secpolicyindex *); 296 #endif 297 #ifdef INET6 298 static void ipsec6_get_ulp(const struct mbuf *m, struct secpolicyindex *, int); 299 static void ipsec6_setspidx_ipaddr(const struct mbuf *, 300 struct secpolicyindex *); 301 #endif 302 303 /* 304 * Return a held reference to the default SP. 305 */ 306 static struct secpolicy * 307 key_allocsp_default(void) 308 { 309 310 key_addref(V_def_policy); 311 return (V_def_policy); 312 } 313 314 static void 315 ipsec_invalidate_cache(struct inpcb *inp, u_int dir) 316 { 317 struct secpolicy *sp; 318 319 INP_WLOCK_ASSERT(inp); 320 if (dir == IPSEC_DIR_OUTBOUND) { 321 if (inp->inp_sp->flags & INP_INBOUND_POLICY) 322 return; 323 sp = inp->inp_sp->sp_in; 324 inp->inp_sp->sp_in = NULL; 325 } else { 326 if (inp->inp_sp->flags & INP_OUTBOUND_POLICY) 327 return; 328 sp = inp->inp_sp->sp_out; 329 inp->inp_sp->sp_out = NULL; 330 } 331 if (sp != NULL) 332 key_freesp(&sp); /* release extra reference */ 333 } 334 335 static void 336 ipsec_cachepolicy(struct inpcb *inp, struct secpolicy *sp, u_int dir) 337 { 338 uint32_t genid; 339 int downgrade; 340 341 INP_LOCK_ASSERT(inp); 342 343 if (dir == IPSEC_DIR_OUTBOUND) { 344 /* Do we have configured PCB policy? */ 345 if (inp->inp_sp->flags & INP_OUTBOUND_POLICY) 346 return; 347 /* Another thread has already set cached policy */ 348 if (inp->inp_sp->sp_out != NULL) 349 return; 350 /* 351 * Do not cache OUTBOUND policy if PCB isn't connected, 352 * i.e. foreign address is INADDR_ANY/UNSPECIFIED. 353 */ 354 #ifdef INET 355 if ((inp->inp_vflag & INP_IPV4) != 0 && 356 inp->inp_faddr.s_addr == INADDR_ANY) 357 return; 358 #endif 359 #ifdef INET6 360 if ((inp->inp_vflag & INP_IPV6) != 0 && 361 IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) 362 return; 363 #endif 364 } else { 365 /* Do we have configured PCB policy? */ 366 if (inp->inp_sp->flags & INP_INBOUND_POLICY) 367 return; 368 /* Another thread has already set cached policy */ 369 if (inp->inp_sp->sp_in != NULL) 370 return; 371 /* 372 * Do not cache INBOUND policy for listen socket, 373 * that is bound to INADDR_ANY/UNSPECIFIED address. 374 */ 375 #ifdef INET 376 if ((inp->inp_vflag & INP_IPV4) != 0 && 377 inp->inp_faddr.s_addr == INADDR_ANY) 378 return; 379 #endif 380 #ifdef INET6 381 if ((inp->inp_vflag & INP_IPV6) != 0 && 382 IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) 383 return; 384 #endif 385 } 386 downgrade = 0; 387 if (!INP_WLOCKED(inp)) { 388 if ((downgrade = INP_TRY_UPGRADE(inp)) == 0) 389 return; 390 } 391 if (dir == IPSEC_DIR_OUTBOUND) 392 inp->inp_sp->sp_out = sp; 393 else 394 inp->inp_sp->sp_in = sp; 395 /* 396 * SP is already referenced by the lookup code. 397 * We take extra reference here to avoid race in the 398 * ipsec_getpcbpolicy() function - SP will not be freed in the 399 * time between we take SP pointer from the cache and key_addref() 400 * call. 401 */ 402 key_addref(sp); 403 genid = key_getspgen(); 404 if (genid != inp->inp_sp->genid) { 405 ipsec_invalidate_cache(inp, dir); 406 inp->inp_sp->genid = genid; 407 } 408 KEYDBG(IPSEC_STAMP, 409 printf("%s: PCB(%p): cached %s SP(%p)\n", 410 __func__, inp, dir == IPSEC_DIR_OUTBOUND ? "OUTBOUND": 411 "INBOUND", sp)); 412 if (downgrade != 0) 413 INP_DOWNGRADE(inp); 414 } 415 416 static struct secpolicy * 417 ipsec_checkpolicy(struct secpolicy *sp, struct inpcb *inp, int *error) 418 { 419 420 /* Save found OUTBOUND policy into PCB SP cache. */ 421 if (inp != NULL && inp->inp_sp != NULL && inp->inp_sp->sp_out == NULL) 422 ipsec_cachepolicy(inp, sp, IPSEC_DIR_OUTBOUND); 423 424 switch (sp->policy) { 425 default: 426 printf("%s: invalid policy %u\n", __func__, sp->policy); 427 /* FALLTHROUGH */ 428 case IPSEC_POLICY_DISCARD: 429 *error = -EINVAL; /* Packet is discarded by caller. */ 430 /* FALLTHROUGH */ 431 case IPSEC_POLICY_BYPASS: 432 case IPSEC_POLICY_NONE: 433 key_freesp(&sp); 434 sp = NULL; /* NB: force NULL result. */ 435 break; 436 case IPSEC_POLICY_IPSEC: 437 /* XXXAE: handle LARVAL SP */ 438 break; 439 } 440 KEYDBG(IPSEC_DUMP, 441 printf("%s: get SP(%p), error %d\n", __func__, sp, *error)); 442 return (sp); 443 } 444 445 static struct secpolicy * 446 ipsec_getpcbpolicy(struct inpcb *inp, u_int dir) 447 { 448 struct secpolicy *sp; 449 int flags, downgrade; 450 451 if (inp == NULL || inp->inp_sp == NULL) 452 return (NULL); 453 454 INP_LOCK_ASSERT(inp); 455 456 flags = inp->inp_sp->flags; 457 if (dir == IPSEC_DIR_OUTBOUND) { 458 sp = inp->inp_sp->sp_out; 459 flags &= INP_OUTBOUND_POLICY; 460 } else { 461 sp = inp->inp_sp->sp_in; 462 flags &= INP_INBOUND_POLICY; 463 } 464 /* 465 * Check flags. If we have PCB SP, just return it. 466 * Otherwise we need to check that cached SP entry isn't stale. 467 */ 468 if (flags == 0) { 469 if (sp == NULL) 470 return (NULL); 471 if (inp->inp_sp->genid != key_getspgen()) { 472 /* Invalidate the cache. */ 473 downgrade = 0; 474 if (!INP_WLOCKED(inp)) { 475 if ((downgrade = INP_TRY_UPGRADE(inp)) == 0) 476 return (NULL); 477 } 478 ipsec_invalidate_cache(inp, IPSEC_DIR_OUTBOUND); 479 ipsec_invalidate_cache(inp, IPSEC_DIR_INBOUND); 480 if (downgrade != 0) 481 INP_DOWNGRADE(inp); 482 return (NULL); 483 } 484 KEYDBG(IPSEC_STAMP, 485 printf("%s: PCB(%p): cache hit SP(%p)\n", 486 __func__, inp, sp)); 487 /* Return referenced cached policy */ 488 } 489 key_addref(sp); 490 return (sp); 491 } 492 493 #ifdef INET 494 static void 495 ipsec4_get_ulp(const struct mbuf *m, struct secpolicyindex *spidx, 496 int needport) 497 { 498 uint8_t nxt; 499 int off; 500 501 /* Sanity check. */ 502 IPSEC_ASSERT(m->m_pkthdr.len >= sizeof(struct ip), 503 ("packet too short")); 504 505 if (m->m_len >= sizeof (struct ip)) { 506 const struct ip *ip = mtod(m, const struct ip *); 507 if (ip->ip_off & htons(IP_MF | IP_OFFMASK)) 508 goto done; 509 off = ip->ip_hl << 2; 510 nxt = ip->ip_p; 511 } else { 512 struct ip ih; 513 514 m_copydata(m, 0, sizeof (struct ip), (caddr_t) &ih); 515 if (ih.ip_off & htons(IP_MF | IP_OFFMASK)) 516 goto done; 517 off = ih.ip_hl << 2; 518 nxt = ih.ip_p; 519 } 520 521 while (off < m->m_pkthdr.len) { 522 struct ip6_ext ip6e; 523 struct tcphdr th; 524 struct udphdr uh; 525 526 switch (nxt) { 527 case IPPROTO_TCP: 528 spidx->ul_proto = nxt; 529 if (!needport) 530 goto done_proto; 531 if (off + sizeof(struct tcphdr) > m->m_pkthdr.len) 532 goto done; 533 m_copydata(m, off, sizeof (th), (caddr_t) &th); 534 spidx->src.sin.sin_port = th.th_sport; 535 spidx->dst.sin.sin_port = th.th_dport; 536 return; 537 case IPPROTO_UDP: 538 spidx->ul_proto = nxt; 539 if (!needport) 540 goto done_proto; 541 if (off + sizeof(struct udphdr) > m->m_pkthdr.len) 542 goto done; 543 m_copydata(m, off, sizeof (uh), (caddr_t) &uh); 544 spidx->src.sin.sin_port = uh.uh_sport; 545 spidx->dst.sin.sin_port = uh.uh_dport; 546 return; 547 case IPPROTO_AH: 548 if (off + sizeof(ip6e) > m->m_pkthdr.len) 549 goto done; 550 /* XXX Sigh, this works but is totally bogus. */ 551 m_copydata(m, off, sizeof(ip6e), (caddr_t) &ip6e); 552 off += (ip6e.ip6e_len + 2) << 2; 553 nxt = ip6e.ip6e_nxt; 554 break; 555 case IPPROTO_ICMP: 556 default: 557 /* XXX Intermediate headers??? */ 558 spidx->ul_proto = nxt; 559 goto done_proto; 560 } 561 } 562 done: 563 spidx->ul_proto = IPSEC_ULPROTO_ANY; 564 done_proto: 565 spidx->src.sin.sin_port = IPSEC_PORT_ANY; 566 spidx->dst.sin.sin_port = IPSEC_PORT_ANY; 567 KEYDBG(IPSEC_DUMP, 568 printf("%s: ", __func__); kdebug_secpolicyindex(spidx, NULL)); 569 } 570 571 static void 572 ipsec4_setspidx_ipaddr(const struct mbuf *m, struct secpolicyindex *spidx) 573 { 574 575 ipsec4_setsockaddrs(m, &spidx->src, &spidx->dst); 576 spidx->prefs = sizeof(struct in_addr) << 3; 577 spidx->prefd = sizeof(struct in_addr) << 3; 578 } 579 580 static struct secpolicy * 581 ipsec4_getpolicy(const struct mbuf *m, struct inpcb *inp, u_int dir, 582 int needport) 583 { 584 struct secpolicyindex spidx; 585 struct secpolicy *sp; 586 587 sp = ipsec_getpcbpolicy(inp, dir); 588 if (sp == NULL && key_havesp(dir)) { 589 /* Make an index to look for a policy. */ 590 ipsec4_setspidx_ipaddr(m, &spidx); 591 ipsec4_get_ulp(m, &spidx, needport); 592 spidx.dir = dir; 593 sp = key_allocsp(&spidx, dir); 594 } 595 if (sp == NULL) /* No SP found, use system default. */ 596 sp = key_allocsp_default(); 597 return (sp); 598 } 599 600 /* 601 * Check security policy for *OUTBOUND* IPv4 packet. 602 */ 603 struct secpolicy * 604 ipsec4_checkpolicy(const struct mbuf *m, struct inpcb *inp, int *error, 605 int needport) 606 { 607 struct secpolicy *sp; 608 609 *error = 0; 610 sp = ipsec4_getpolicy(m, inp, IPSEC_DIR_OUTBOUND, needport); 611 if (sp != NULL) 612 sp = ipsec_checkpolicy(sp, inp, error); 613 if (sp == NULL) { 614 switch (*error) { 615 case 0: /* No IPsec required: BYPASS or NONE */ 616 break; 617 case -EINVAL: 618 IPSECSTAT_INC(ips_out_polvio); 619 break; 620 default: 621 IPSECSTAT_INC(ips_out_inval); 622 } 623 } 624 KEYDBG(IPSEC_STAMP, 625 printf("%s: using SP(%p), error %d\n", __func__, sp, *error)); 626 if (sp != NULL) 627 KEYDBG(IPSEC_DATA, kdebug_secpolicy(sp)); 628 return (sp); 629 } 630 631 /* 632 * Check IPv4 packet against *INBOUND* security policy. 633 * This function is called from tcp_input(), udp_input(), 634 * rip_input() and sctp_input(). 635 */ 636 int 637 ipsec4_in_reject(const struct mbuf *m, struct inpcb *inp) 638 { 639 struct secpolicy *sp; 640 int result; 641 642 sp = ipsec4_getpolicy(m, inp, IPSEC_DIR_INBOUND, 0); 643 result = ipsec_in_reject(sp, inp, m); 644 key_freesp(&sp); 645 if (result != 0) 646 IPSECSTAT_INC(ips_in_polvio); 647 return (result); 648 } 649 650 /* 651 * IPSEC_CAP() method implementation for IPv4. 652 */ 653 int 654 ipsec4_capability(struct mbuf *m, u_int cap) 655 { 656 657 switch (cap) { 658 case IPSEC_CAP_BYPASS_FILTER: 659 /* 660 * Bypass packet filtering for packets previously handled 661 * by IPsec. 662 */ 663 if (!V_ip4_filtertunnel && 664 m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL) 665 return (1); 666 return (0); 667 case IPSEC_CAP_OPERABLE: 668 /* Do we have active security policies? */ 669 return (key_havesp_any()); 670 }; 671 return (EOPNOTSUPP); 672 } 673 674 #endif /* INET */ 675 676 #ifdef INET6 677 static void 678 ipsec6_get_ulp(const struct mbuf *m, struct secpolicyindex *spidx, 679 int needport) 680 { 681 struct tcphdr th; 682 struct udphdr uh; 683 struct icmp6_hdr ih; 684 int off, nxt; 685 686 IPSEC_ASSERT(m->m_pkthdr.len >= sizeof(struct ip6_hdr), 687 ("packet too short")); 688 689 /* Set default. */ 690 spidx->ul_proto = IPSEC_ULPROTO_ANY; 691 spidx->src.sin6.sin6_port = IPSEC_PORT_ANY; 692 spidx->dst.sin6.sin6_port = IPSEC_PORT_ANY; 693 694 nxt = -1; 695 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt); 696 if (off < 0 || m->m_pkthdr.len < off) 697 return; 698 699 switch (nxt) { 700 case IPPROTO_TCP: 701 spidx->ul_proto = nxt; 702 if (!needport) 703 break; 704 if (off + sizeof(struct tcphdr) > m->m_pkthdr.len) 705 break; 706 m_copydata(m, off, sizeof(th), (caddr_t)&th); 707 spidx->src.sin6.sin6_port = th.th_sport; 708 spidx->dst.sin6.sin6_port = th.th_dport; 709 break; 710 case IPPROTO_UDP: 711 spidx->ul_proto = nxt; 712 if (!needport) 713 break; 714 if (off + sizeof(struct udphdr) > m->m_pkthdr.len) 715 break; 716 m_copydata(m, off, sizeof(uh), (caddr_t)&uh); 717 spidx->src.sin6.sin6_port = uh.uh_sport; 718 spidx->dst.sin6.sin6_port = uh.uh_dport; 719 break; 720 case IPPROTO_ICMPV6: 721 spidx->ul_proto = nxt; 722 if (off + sizeof(struct icmp6_hdr) > m->m_pkthdr.len) 723 break; 724 m_copydata(m, off, sizeof(ih), (caddr_t)&ih); 725 spidx->src.sin6.sin6_port = htons((uint16_t)ih.icmp6_type); 726 spidx->dst.sin6.sin6_port = htons((uint16_t)ih.icmp6_code); 727 break; 728 default: 729 /* XXX Intermediate headers??? */ 730 spidx->ul_proto = nxt; 731 break; 732 } 733 KEYDBG(IPSEC_DUMP, 734 printf("%s: ", __func__); kdebug_secpolicyindex(spidx, NULL)); 735 } 736 737 static void 738 ipsec6_setspidx_ipaddr(const struct mbuf *m, struct secpolicyindex *spidx) 739 { 740 741 ipsec6_setsockaddrs(m, &spidx->src, &spidx->dst); 742 spidx->prefs = sizeof(struct in6_addr) << 3; 743 spidx->prefd = sizeof(struct in6_addr) << 3; 744 } 745 746 static struct secpolicy * 747 ipsec6_getpolicy(const struct mbuf *m, struct inpcb *inp, u_int dir, 748 int needport) 749 { 750 struct secpolicyindex spidx; 751 struct secpolicy *sp; 752 753 sp = ipsec_getpcbpolicy(inp, dir); 754 if (sp == NULL && key_havesp(dir)) { 755 /* Make an index to look for a policy. */ 756 ipsec6_setspidx_ipaddr(m, &spidx); 757 ipsec6_get_ulp(m, &spidx, needport); 758 spidx.dir = dir; 759 sp = key_allocsp(&spidx, dir); 760 } 761 if (sp == NULL) /* No SP found, use system default. */ 762 sp = key_allocsp_default(); 763 return (sp); 764 } 765 766 /* 767 * Check security policy for *OUTBOUND* IPv6 packet. 768 */ 769 struct secpolicy * 770 ipsec6_checkpolicy(const struct mbuf *m, struct inpcb *inp, int *error, 771 int needport) 772 { 773 struct secpolicy *sp; 774 775 *error = 0; 776 sp = ipsec6_getpolicy(m, inp, IPSEC_DIR_OUTBOUND, needport); 777 if (sp != NULL) 778 sp = ipsec_checkpolicy(sp, inp, error); 779 if (sp == NULL) { 780 switch (*error) { 781 case 0: /* No IPsec required: BYPASS or NONE */ 782 break; 783 case -EINVAL: 784 IPSEC6STAT_INC(ips_out_polvio); 785 break; 786 default: 787 IPSEC6STAT_INC(ips_out_inval); 788 } 789 } 790 KEYDBG(IPSEC_STAMP, 791 printf("%s: using SP(%p), error %d\n", __func__, sp, *error)); 792 if (sp != NULL) 793 KEYDBG(IPSEC_DATA, kdebug_secpolicy(sp)); 794 return (sp); 795 } 796 797 /* 798 * Check IPv6 packet against inbound security policy. 799 * This function is called from tcp6_input(), udp6_input(), 800 * rip6_input() and sctp_input(). 801 */ 802 int 803 ipsec6_in_reject(const struct mbuf *m, struct inpcb *inp) 804 { 805 struct secpolicy *sp; 806 int result; 807 808 sp = ipsec6_getpolicy(m, inp, IPSEC_DIR_INBOUND, 0); 809 result = ipsec_in_reject(sp, inp, m); 810 key_freesp(&sp); 811 if (result) 812 IPSEC6STAT_INC(ips_in_polvio); 813 return (result); 814 } 815 816 /* 817 * IPSEC_CAP() method implementation for IPv6. 818 */ 819 int 820 ipsec6_capability(struct mbuf *m, u_int cap) 821 { 822 823 switch (cap) { 824 case IPSEC_CAP_BYPASS_FILTER: 825 /* 826 * Bypass packet filtering for packets previously handled 827 * by IPsec. 828 */ 829 if (!V_ip6_filtertunnel && 830 m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL) 831 return (1); 832 return (0); 833 case IPSEC_CAP_OPERABLE: 834 /* Do we have active security policies? */ 835 return (key_havesp_any()); 836 }; 837 return (EOPNOTSUPP); 838 } 839 #endif /* INET6 */ 840 841 int 842 ipsec_run_hhooks(struct ipsec_ctx_data *ctx, int type) 843 { 844 int idx; 845 846 switch (ctx->af) { 847 #ifdef INET 848 case AF_INET: 849 idx = HHOOK_IPSEC_INET; 850 break; 851 #endif 852 #ifdef INET6 853 case AF_INET6: 854 idx = HHOOK_IPSEC_INET6; 855 break; 856 #endif 857 default: 858 return (EPFNOSUPPORT); 859 } 860 if (type == HHOOK_TYPE_IPSEC_IN) 861 HHOOKS_RUN_IF(V_ipsec_hhh_in[idx], ctx, NULL); 862 else 863 HHOOKS_RUN_IF(V_ipsec_hhh_out[idx], ctx, NULL); 864 if (*ctx->mp == NULL) 865 return (EACCES); 866 return (0); 867 } 868 869 /* 870 * Return current level. 871 * Either IPSEC_LEVEL_USE or IPSEC_LEVEL_REQUIRE are always returned. 872 */ 873 u_int 874 ipsec_get_reqlevel(struct secpolicy *sp, u_int idx) 875 { 876 struct ipsecrequest *isr; 877 u_int esp_trans_deflev, esp_net_deflev; 878 u_int ah_trans_deflev, ah_net_deflev; 879 u_int level = 0; 880 881 IPSEC_ASSERT(idx < sp->tcount, ("Wrong IPsec request index %d", idx)); 882 /* XXX Note that we have ipseclog() expanded here - code sync issue. */ 883 #define IPSEC_CHECK_DEFAULT(lev) \ 884 (((lev) != IPSEC_LEVEL_USE && (lev) != IPSEC_LEVEL_REQUIRE && \ 885 (lev) != IPSEC_LEVEL_UNIQUE) \ 886 ? (V_ipsec_debug ? \ 887 log(LOG_INFO, "fixed system default level " #lev ":%d->%d\n",\ 888 (lev), IPSEC_LEVEL_REQUIRE) : 0), \ 889 (lev) = IPSEC_LEVEL_REQUIRE, (lev) : (lev)) 890 891 /* 892 * IPsec VTI uses unique security policy with fake spidx filled 893 * with zeroes. Just return IPSEC_LEVEL_REQUIRE instead of doing 894 * full level lookup for such policies. 895 */ 896 if (sp->state == IPSEC_SPSTATE_IFNET) { 897 IPSEC_ASSERT(sp->req[idx]->level == IPSEC_LEVEL_UNIQUE, 898 ("Wrong IPsec request level %d", sp->req[idx]->level)); 899 return (IPSEC_LEVEL_REQUIRE); 900 } 901 902 /* Set default level. */ 903 switch (sp->spidx.src.sa.sa_family) { 904 #ifdef INET 905 case AF_INET: 906 esp_trans_deflev = IPSEC_CHECK_DEFAULT(V_ip4_esp_trans_deflev); 907 esp_net_deflev = IPSEC_CHECK_DEFAULT(V_ip4_esp_net_deflev); 908 ah_trans_deflev = IPSEC_CHECK_DEFAULT(V_ip4_ah_trans_deflev); 909 ah_net_deflev = IPSEC_CHECK_DEFAULT(V_ip4_ah_net_deflev); 910 break; 911 #endif 912 #ifdef INET6 913 case AF_INET6: 914 esp_trans_deflev = IPSEC_CHECK_DEFAULT(V_ip6_esp_trans_deflev); 915 esp_net_deflev = IPSEC_CHECK_DEFAULT(V_ip6_esp_net_deflev); 916 ah_trans_deflev = IPSEC_CHECK_DEFAULT(V_ip6_ah_trans_deflev); 917 ah_net_deflev = IPSEC_CHECK_DEFAULT(V_ip6_ah_net_deflev); 918 break; 919 #endif /* INET6 */ 920 default: 921 panic("%s: unknown af %u", 922 __func__, sp->spidx.src.sa.sa_family); 923 } 924 925 #undef IPSEC_CHECK_DEFAULT 926 927 isr = sp->req[idx]; 928 /* Set level. */ 929 switch (isr->level) { 930 case IPSEC_LEVEL_DEFAULT: 931 switch (isr->saidx.proto) { 932 case IPPROTO_ESP: 933 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) 934 level = esp_net_deflev; 935 else 936 level = esp_trans_deflev; 937 break; 938 case IPPROTO_AH: 939 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) 940 level = ah_net_deflev; 941 else 942 level = ah_trans_deflev; 943 break; 944 case IPPROTO_IPCOMP: 945 /* 946 * We don't really care, as IPcomp document says that 947 * we shouldn't compress small packets. 948 */ 949 level = IPSEC_LEVEL_USE; 950 break; 951 default: 952 panic("%s: Illegal protocol defined %u\n", __func__, 953 isr->saidx.proto); 954 } 955 break; 956 957 case IPSEC_LEVEL_USE: 958 case IPSEC_LEVEL_REQUIRE: 959 level = isr->level; 960 break; 961 case IPSEC_LEVEL_UNIQUE: 962 level = IPSEC_LEVEL_REQUIRE; 963 break; 964 965 default: 966 panic("%s: Illegal IPsec level %u\n", __func__, isr->level); 967 } 968 969 return (level); 970 } 971 972 static int 973 ipsec_check_history(const struct mbuf *m, struct secpolicy *sp, u_int idx) 974 { 975 struct xform_history *xh; 976 struct m_tag *mtag; 977 978 mtag = NULL; 979 while ((mtag = m_tag_find(__DECONST(struct mbuf *, m), 980 PACKET_TAG_IPSEC_IN_DONE, mtag)) != NULL) { 981 xh = (struct xform_history *)(mtag + 1); 982 KEYDBG(IPSEC_DATA, 983 char buf[IPSEC_ADDRSTRLEN]; 984 printf("%s: mode %s proto %u dst %s\n", __func__, 985 kdebug_secasindex_mode(xh->mode), xh->proto, 986 ipsec_address(&xh->dst, buf, sizeof(buf)))); 987 if (xh->proto != sp->req[idx]->saidx.proto) 988 continue; 989 /* If SA had IPSEC_MODE_ANY, consider this as match. */ 990 if (xh->mode != sp->req[idx]->saidx.mode && 991 xh->mode != IPSEC_MODE_ANY) 992 continue; 993 /* 994 * For transport mode IPsec request doesn't contain 995 * addresses. We need to use address from spidx. 996 */ 997 if (sp->req[idx]->saidx.mode == IPSEC_MODE_TRANSPORT) { 998 if (key_sockaddrcmp_withmask(&xh->dst.sa, 999 &sp->spidx.dst.sa, sp->spidx.prefd) != 0) 1000 continue; 1001 } else { 1002 if (key_sockaddrcmp(&xh->dst.sa, 1003 &sp->req[idx]->saidx.dst.sa, 0) != 0) 1004 continue; 1005 } 1006 return (0); /* matched */ 1007 } 1008 return (1); 1009 } 1010 1011 /* 1012 * Check security policy requirements against the actual 1013 * packet contents. Return one if the packet should be 1014 * rejected as "invalid"; otherwise return zero to have the 1015 * packet treated as "valid". 1016 * 1017 * OUT: 1018 * 0: valid 1019 * 1: invalid 1020 */ 1021 static int 1022 ipsec_in_reject(struct secpolicy *sp, struct inpcb *inp, const struct mbuf *m) 1023 { 1024 int i; 1025 1026 KEYDBG(IPSEC_STAMP, 1027 printf("%s: PCB(%p): using SP(%p)\n", __func__, inp, sp)); 1028 KEYDBG(IPSEC_DATA, kdebug_secpolicy(sp)); 1029 1030 if (inp != NULL && inp->inp_sp != NULL && inp->inp_sp->sp_in == NULL) 1031 ipsec_cachepolicy(inp, sp, IPSEC_DIR_INBOUND); 1032 1033 /* Check policy. */ 1034 switch (sp->policy) { 1035 case IPSEC_POLICY_DISCARD: 1036 return (1); 1037 case IPSEC_POLICY_BYPASS: 1038 case IPSEC_POLICY_NONE: 1039 return (0); 1040 } 1041 1042 IPSEC_ASSERT(sp->policy == IPSEC_POLICY_IPSEC, 1043 ("invalid policy %u", sp->policy)); 1044 1045 /* 1046 * ipsec[46]_common_input_cb after each transform adds 1047 * PACKET_TAG_IPSEC_IN_DONE mbuf tag. It contains SPI, proto, mode 1048 * and destination address from saidx. We can compare info from 1049 * these tags with requirements in SP. 1050 */ 1051 for (i = 0; i < sp->tcount; i++) { 1052 /* 1053 * Do not check IPcomp, since IPcomp document 1054 * says that we shouldn't compress small packets. 1055 * IPComp policy should always be treated as being 1056 * in "use" level. 1057 */ 1058 if (sp->req[i]->saidx.proto == IPPROTO_IPCOMP || 1059 ipsec_get_reqlevel(sp, i) != IPSEC_LEVEL_REQUIRE) 1060 continue; 1061 if (V_check_policy_history != 0 && 1062 ipsec_check_history(m, sp, i) != 0) 1063 return (1); 1064 else switch (sp->req[i]->saidx.proto) { 1065 case IPPROTO_ESP: 1066 if ((m->m_flags & M_DECRYPTED) == 0) { 1067 KEYDBG(IPSEC_DUMP, 1068 printf("%s: ESP m_flags:%x\n", __func__, 1069 m->m_flags)); 1070 return (1); 1071 } 1072 break; 1073 case IPPROTO_AH: 1074 if ((m->m_flags & M_AUTHIPHDR) == 0) { 1075 KEYDBG(IPSEC_DUMP, 1076 printf("%s: AH m_flags:%x\n", __func__, 1077 m->m_flags)); 1078 return (1); 1079 } 1080 break; 1081 } 1082 } 1083 return (0); /* Valid. */ 1084 } 1085 1086 /* 1087 * Compute the byte size to be occupied by IPsec header. 1088 * In case it is tunnelled, it includes the size of outer IP header. 1089 */ 1090 size_t 1091 ipsec_hdrsiz_internal(struct secpolicy *sp) 1092 { 1093 size_t size; 1094 int i; 1095 1096 KEYDBG(IPSEC_STAMP, printf("%s: using SP(%p)\n", __func__, sp)); 1097 KEYDBG(IPSEC_DATA, kdebug_secpolicy(sp)); 1098 1099 switch (sp->policy) { 1100 case IPSEC_POLICY_DISCARD: 1101 case IPSEC_POLICY_BYPASS: 1102 case IPSEC_POLICY_NONE: 1103 return (0); 1104 } 1105 1106 IPSEC_ASSERT(sp->policy == IPSEC_POLICY_IPSEC, 1107 ("invalid policy %u", sp->policy)); 1108 1109 /* 1110 * XXX: for each transform we need to lookup suitable SA 1111 * and use info from SA to calculate headers size. 1112 * XXX: for NAT-T we need to cosider UDP header size. 1113 */ 1114 size = 0; 1115 for (i = 0; i < sp->tcount; i++) { 1116 switch (sp->req[i]->saidx.proto) { 1117 case IPPROTO_ESP: 1118 size += esp_hdrsiz(NULL); 1119 break; 1120 case IPPROTO_AH: 1121 size += ah_hdrsiz(NULL); 1122 break; 1123 case IPPROTO_IPCOMP: 1124 size += sizeof(struct ipcomp); 1125 break; 1126 } 1127 1128 if (sp->req[i]->saidx.mode == IPSEC_MODE_TUNNEL) { 1129 switch (sp->req[i]->saidx.dst.sa.sa_family) { 1130 #ifdef INET 1131 case AF_INET: 1132 size += sizeof(struct ip); 1133 break; 1134 #endif 1135 #ifdef INET6 1136 case AF_INET6: 1137 size += sizeof(struct ip6_hdr); 1138 break; 1139 #endif 1140 default: 1141 ipseclog((LOG_ERR, "%s: unknown AF %d in " 1142 "IPsec tunnel SA\n", __func__, 1143 sp->req[i]->saidx.dst.sa.sa_family)); 1144 break; 1145 } 1146 } 1147 } 1148 return (size); 1149 } 1150 1151 /* 1152 * Compute ESP/AH header size for protocols with PCB, including 1153 * outer IP header. Currently only tcp_output() uses it. 1154 */ 1155 size_t 1156 ipsec_hdrsiz_inpcb(struct inpcb *inp) 1157 { 1158 struct secpolicyindex spidx; 1159 struct secpolicy *sp; 1160 size_t sz; 1161 1162 sp = ipsec_getpcbpolicy(inp, IPSEC_DIR_OUTBOUND); 1163 if (sp == NULL && key_havesp(IPSEC_DIR_OUTBOUND)) { 1164 ipsec_setspidx_inpcb(inp, &spidx, IPSEC_DIR_OUTBOUND); 1165 sp = key_allocsp(&spidx, IPSEC_DIR_OUTBOUND); 1166 } 1167 if (sp == NULL) 1168 sp = key_allocsp_default(); 1169 sz = ipsec_hdrsiz_internal(sp); 1170 key_freesp(&sp); 1171 return (sz); 1172 } 1173 1174 1175 #define IPSEC_BITMAP_INDEX_MASK(w) (w - 1) 1176 #define IPSEC_REDUNDANT_BIT_SHIFTS 5 1177 #define IPSEC_REDUNDANT_BITS (1 << IPSEC_REDUNDANT_BIT_SHIFTS) 1178 #define IPSEC_BITMAP_LOC_MASK (IPSEC_REDUNDANT_BITS - 1) 1179 1180 /* 1181 * Functions below are responsible for checking and updating bitmap. 1182 * These are used to separate ipsec_chkreplay() and ipsec_updatereplay() 1183 * from window implementation 1184 * 1185 * Based on RFC 6479. Blocks are 32 bits unsigned integers 1186 */ 1187 1188 static inline int 1189 check_window(const struct secreplay *replay, uint64_t seq) 1190 { 1191 int index, bit_location; 1192 1193 SECREPLAY_ASSERT(replay); 1194 1195 bit_location = seq & IPSEC_BITMAP_LOC_MASK; 1196 index = (seq >> IPSEC_REDUNDANT_BIT_SHIFTS) 1197 & IPSEC_BITMAP_INDEX_MASK(replay->bitmap_size); 1198 1199 /* This packet already seen? */ 1200 return ((replay->bitmap)[index] & (1 << bit_location)); 1201 } 1202 1203 static inline void 1204 advance_window(const struct secreplay *replay, uint64_t seq) 1205 { 1206 int i; 1207 uint64_t index, index_cur, diff; 1208 1209 SECREPLAY_ASSERT(replay); 1210 1211 index_cur = replay->last >> IPSEC_REDUNDANT_BIT_SHIFTS; 1212 index = seq >> IPSEC_REDUNDANT_BIT_SHIFTS; 1213 diff = index - index_cur; 1214 1215 if (diff > replay->bitmap_size) { 1216 /* something unusual in this case */ 1217 diff = replay->bitmap_size; 1218 } 1219 1220 for (i = 0; i < diff; i++) { 1221 replay->bitmap[(i + index_cur + 1) 1222 & IPSEC_BITMAP_INDEX_MASK(replay->bitmap_size)] = 0; 1223 } 1224 } 1225 1226 static inline void 1227 set_window(const struct secreplay *replay, uint64_t seq) 1228 { 1229 int index, bit_location; 1230 1231 SECREPLAY_ASSERT(replay); 1232 1233 bit_location = seq & IPSEC_BITMAP_LOC_MASK; 1234 index = (seq >> IPSEC_REDUNDANT_BIT_SHIFTS) 1235 & IPSEC_BITMAP_INDEX_MASK(replay->bitmap_size); 1236 1237 replay->bitmap[index] |= (1 << bit_location); 1238 } 1239 1240 /* 1241 * Check the variable replay window. 1242 * ipsec_chkreplay() performs replay check before ICV verification. 1243 * ipsec_updatereplay() updates replay bitmap. This must be called after 1244 * ICV verification (it also performs replay check, which is usually done 1245 * beforehand). 1246 * 0 (zero) is returned if packet disallowed, 1 if packet permitted. 1247 * 1248 * Based on RFC 4303 1249 */ 1250 1251 int 1252 ipsec_chkreplay(uint32_t seq, uint32_t *seqhigh, struct secasvar *sav) 1253 { 1254 char buf[128]; 1255 struct secreplay *replay; 1256 uint32_t window; 1257 uint32_t tl, th, bl; 1258 uint32_t seqh; 1259 1260 IPSEC_ASSERT(sav != NULL, ("Null SA")); 1261 IPSEC_ASSERT(sav->replay != NULL, ("Null replay state")); 1262 1263 replay = sav->replay; 1264 1265 /* No need to check replay if disabled. */ 1266 if (replay->wsize == 0) { 1267 return (1); 1268 } 1269 1270 SECREPLAY_LOCK(replay); 1271 1272 /* Zero sequence number is not allowed. */ 1273 if (seq == 0 && replay->last == 0) { 1274 SECREPLAY_UNLOCK(replay); 1275 return (0); 1276 } 1277 1278 window = replay->wsize << 3; /* Size of window */ 1279 tl = (uint32_t)replay->last; /* Top of window, lower part */ 1280 th = (uint32_t)(replay->last >> 32); /* Top of window, high part */ 1281 bl = tl - window + 1; /* Bottom of window, lower part */ 1282 1283 /* 1284 * We keep the high part intact when: 1285 * 1) the seq is within [bl, 0xffffffff] and the whole window is 1286 * within one subspace; 1287 * 2) the seq is within [0, bl) and window spans two subspaces. 1288 */ 1289 if ((tl >= window - 1 && seq >= bl) || 1290 (tl < window - 1 && seq < bl)) { 1291 *seqhigh = th; 1292 if (seq <= tl) { 1293 /* Sequence number inside window - check against replay */ 1294 if (check_window(replay, seq)) { 1295 SECREPLAY_UNLOCK(replay); 1296 return (0); 1297 } 1298 } 1299 1300 SECREPLAY_UNLOCK(replay); 1301 /* Sequence number above top of window or not found in bitmap */ 1302 return (1); 1303 } 1304 1305 /* 1306 * If ESN is not enabled and packet with highest sequence number 1307 * was received we should report overflow 1308 */ 1309 if (tl == 0xffffffff && !(sav->flags & SADB_X_SAFLAGS_ESN)) { 1310 /* Set overflow flag. */ 1311 replay->overflow++; 1312 1313 if ((sav->flags & SADB_X_EXT_CYCSEQ) == 0) { 1314 if (sav->sah->saidx.proto == IPPROTO_ESP) 1315 ESPSTAT_INC(esps_wrap); 1316 else if (sav->sah->saidx.proto == IPPROTO_AH) 1317 AHSTAT_INC(ahs_wrap); 1318 SECREPLAY_UNLOCK(replay); 1319 return (0); 1320 } 1321 1322 ipseclog((LOG_WARNING, "%s: replay counter made %d cycle. %s\n", 1323 __func__, replay->overflow, 1324 ipsec_sa2str(sav, buf, sizeof(buf)))); 1325 } 1326 1327 /* 1328 * Seq is within [bl, 0xffffffff] and bl is within 1329 * [0xffffffff-window, 0xffffffff]. This means we got a seq 1330 * which is within our replay window, but in the previous 1331 * subspace. 1332 */ 1333 if (tl < window - 1 && seq >= bl) { 1334 if (th == 0) 1335 return (0); 1336 *seqhigh = th - 1; 1337 seqh = th - 1; 1338 if (check_window(replay, seq)) { 1339 SECREPLAY_UNLOCK(replay); 1340 return (0); 1341 } 1342 SECREPLAY_UNLOCK(replay); 1343 return (1); 1344 } 1345 1346 /* 1347 * Seq is within [0, bl) but the whole window is within one subspace. 1348 * This means that seq has wrapped and is in next subspace 1349 */ 1350 *seqhigh = th + 1; 1351 seqh = th + 1; 1352 1353 /* Don't let high part wrap. */ 1354 if (seqh == 0) { 1355 /* Set overflow flag. */ 1356 replay->overflow++; 1357 1358 if ((sav->flags & SADB_X_EXT_CYCSEQ) == 0) { 1359 if (sav->sah->saidx.proto == IPPROTO_ESP) 1360 ESPSTAT_INC(esps_wrap); 1361 else if (sav->sah->saidx.proto == IPPROTO_AH) 1362 AHSTAT_INC(ahs_wrap); 1363 SECREPLAY_UNLOCK(replay); 1364 return (0); 1365 } 1366 1367 ipseclog((LOG_WARNING, "%s: replay counter made %d cycle. %s\n", 1368 __func__, replay->overflow, 1369 ipsec_sa2str(sav, buf, sizeof(buf)))); 1370 } 1371 1372 SECREPLAY_UNLOCK(replay); 1373 return (1); 1374 } 1375 1376 /* 1377 * Check replay counter whether to update or not. 1378 * OUT: 0: OK 1379 * 1: NG 1380 */ 1381 int 1382 ipsec_updatereplay(uint32_t seq, struct secasvar *sav) 1383 { 1384 struct secreplay *replay; 1385 uint32_t window; 1386 uint32_t tl, th, bl; 1387 uint32_t seqh; 1388 1389 IPSEC_ASSERT(sav != NULL, ("Null SA")); 1390 IPSEC_ASSERT(sav->replay != NULL, ("Null replay state")); 1391 1392 replay = sav->replay; 1393 1394 /* No need to check replay if disabled. */ 1395 if (replay->wsize == 0) 1396 return (0); 1397 1398 SECREPLAY_LOCK(replay); 1399 1400 /* Zero sequence number is not allowed. */ 1401 if (seq == 0 && replay->last == 0) { 1402 SECREPLAY_UNLOCK(replay); 1403 return (1); 1404 } 1405 1406 window = replay->wsize << 3; /* Size of window */ 1407 tl = (uint32_t)replay->last; /* Top of window, lower part */ 1408 th = (uint32_t)(replay->last >> 32); /* Top of window, high part */ 1409 bl = tl - window + 1; /* Bottom of window, lower part */ 1410 1411 /* 1412 * We keep the high part intact when: 1413 * 1) the seq is within [bl, 0xffffffff] and the whole window is 1414 * within one subspace; 1415 * 2) the seq is within [0, bl) and window spans two subspaces. 1416 */ 1417 if ((tl >= window - 1 && seq >= bl) || 1418 (tl < window - 1 && seq < bl)) { 1419 seqh = th; 1420 if (seq <= tl) { 1421 /* Sequence number inside window - check against replay */ 1422 if (check_window(replay, seq)) { 1423 SECREPLAY_UNLOCK(replay); 1424 return (1); 1425 } 1426 set_window(replay, seq); 1427 } else { 1428 advance_window(replay, ((uint64_t)seqh << 32) | seq); 1429 set_window(replay, seq); 1430 replay->last = ((uint64_t)seqh << 32) | seq; 1431 } 1432 1433 /* Sequence number above top of window or not found in bitmap */ 1434 replay->count++; 1435 SECREPLAY_UNLOCK(replay); 1436 return (0); 1437 } 1438 1439 if (!(sav->flags & SADB_X_SAFLAGS_ESN)) { 1440 SECREPLAY_UNLOCK(replay); 1441 return (1); 1442 } 1443 1444 /* 1445 * Seq is within [bl, 0xffffffff] and bl is within 1446 * [0xffffffff-window, 0xffffffff]. This means we got a seq 1447 * which is within our replay window, but in the previous 1448 * subspace. 1449 */ 1450 if (tl < window - 1 && seq >= bl) { 1451 if (th == 0) { 1452 SECREPLAY_UNLOCK(replay); 1453 return (1); 1454 } 1455 if (check_window(replay, seq)) { 1456 SECREPLAY_UNLOCK(replay); 1457 return (1); 1458 } 1459 1460 set_window(replay, seq); 1461 replay->count++; 1462 SECREPLAY_UNLOCK(replay); 1463 return (0); 1464 } 1465 1466 /* 1467 * Seq is within [0, bl) but the whole window is within one subspace. 1468 * This means that seq has wrapped and is in next subspace 1469 */ 1470 seqh = th + 1; 1471 1472 /* Don't let high part wrap. */ 1473 if (seqh == 0) { 1474 SECREPLAY_UNLOCK(replay); 1475 return (1); 1476 } 1477 1478 advance_window(replay, ((uint64_t)seqh << 32) | seq); 1479 set_window(replay, seq); 1480 replay->last = ((uint64_t)seqh << 32) | seq; 1481 replay->count++; 1482 1483 SECREPLAY_UNLOCK(replay); 1484 return (0); 1485 } 1486 int 1487 ipsec_updateid(struct secasvar *sav, crypto_session_t *new, 1488 crypto_session_t *old) 1489 { 1490 crypto_session_t tmp; 1491 1492 /* 1493 * tdb_cryptoid is initialized by xform_init(). 1494 * Then it can be changed only when some crypto error occurred or 1495 * when SA is deleted. We stored used cryptoid in the xform_data 1496 * structure. In case when crypto error occurred and crypto 1497 * subsystem has reinited the session, it returns new cryptoid 1498 * and EAGAIN error code. 1499 * 1500 * This function will be called when we got EAGAIN from crypto 1501 * subsystem. 1502 * *new is cryptoid that was returned by crypto subsystem in 1503 * the crp_sid. 1504 * *old is the original cryptoid that we stored in xform_data. 1505 * 1506 * For first failed request *old == sav->tdb_cryptoid, then 1507 * we update sav->tdb_cryptoid and redo crypto_dispatch(). 1508 * For next failed request *old != sav->tdb_cryptoid, then 1509 * we store cryptoid from first request into the *new variable 1510 * and crp_sid from this second session will be returned via 1511 * *old pointer, so caller can release second session. 1512 * 1513 * XXXAE: check this more carefully. 1514 */ 1515 KEYDBG(IPSEC_STAMP, 1516 printf("%s: SA(%p) moves cryptoid %p -> %p\n", 1517 __func__, sav, *old, *new)); 1518 KEYDBG(IPSEC_DATA, kdebug_secasv(sav)); 1519 SECASVAR_WLOCK(sav); 1520 if (sav->tdb_cryptoid != *old) { 1521 /* cryptoid was already updated */ 1522 tmp = *new; 1523 *new = sav->tdb_cryptoid; 1524 *old = tmp; 1525 SECASVAR_WUNLOCK(sav); 1526 return (1); 1527 } 1528 sav->tdb_cryptoid = *new; 1529 SECASVAR_WUNLOCK(sav); 1530 return (0); 1531 } 1532 1533 int 1534 ipsec_initialized(void) 1535 { 1536 1537 return (V_def_policy != NULL); 1538 } 1539 1540 static void 1541 def_policy_init(const void *unused __unused) 1542 { 1543 1544 V_def_policy = key_newsp(); 1545 if (V_def_policy != NULL) { 1546 V_def_policy->policy = IPSEC_POLICY_NONE; 1547 /* Force INPCB SP cache invalidation */ 1548 key_bumpspgen(); 1549 } else 1550 printf("%s: failed to initialize default policy\n", __func__); 1551 } 1552 1553 static void 1554 def_policy_uninit(const void *unused __unused) 1555 { 1556 1557 if (V_def_policy != NULL) { 1558 key_freesp(&V_def_policy); 1559 key_bumpspgen(); 1560 } 1561 } 1562 1563 VNET_SYSINIT(def_policy_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_FIRST, 1564 def_policy_init, NULL); 1565 VNET_SYSUNINIT(def_policy_uninit, SI_SUB_PROTO_DOMAIN, SI_ORDER_FIRST, 1566 def_policy_uninit, NULL);
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