1 /* $KAME: ipsec.c,v 1.103 2001/05/24 07:14:18 sakane Exp $ */ 2 3 /*- 4 * SPDX-License-Identifier: BSD-3-Clause 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 /* 35 * IPsec controller part. 36 */ 37 38 #include "opt_inet.h" 39 #include "opt_inet6.h" 40 #include "opt_ipsec.h" 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/malloc.h> 45 #include <sys/mbuf.h> 46 #include <sys/domain.h> 47 #include <sys/priv.h> 48 #include <sys/protosw.h> 49 #include <sys/socket.h> 50 #include <sys/socketvar.h> 51 #include <sys/errno.h> 52 #include <sys/hhook.h> 53 #include <sys/time.h> 54 #include <sys/kernel.h> 55 #include <sys/syslog.h> 56 #include <sys/sysctl.h> 57 #include <sys/proc.h> 58 59 #include <net/if.h> 60 #include <net/if_enc.h> 61 #include <net/if_var.h> 62 #include <net/vnet.h> 63 64 #include <netinet/in.h> 65 #include <netinet/in_systm.h> 66 #include <netinet/ip.h> 67 #include <netinet/ip_var.h> 68 #include <netinet/in_var.h> 69 #include <netinet/udp.h> 70 #include <netinet/udp_var.h> 71 #include <netinet/tcp.h> 72 #include <netinet/udp.h> 73 74 #include <netinet/ip6.h> 75 #ifdef INET6 76 #include <netinet6/ip6_var.h> 77 #endif 78 #include <netinet/in_pcb.h> 79 #ifdef INET6 80 #include <netinet/icmp6.h> 81 #endif 82 83 #include <sys/types.h> 84 #include <netipsec/ipsec.h> 85 #ifdef INET6 86 #include <netipsec/ipsec6.h> 87 #endif 88 #include <netipsec/ipsec_offload.h> 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 #ifdef IPSEC_OFFLOAD 641 struct ipsec_accel_in_tag *tag; 642 #endif 643 int result; 644 645 #ifdef IPSEC_OFFLOAD 646 tag = ipsec_accel_input_tag_lookup(m); 647 if (tag != NULL) 648 return (0); 649 #endif 650 sp = ipsec4_getpolicy(m, inp, IPSEC_DIR_INBOUND, 0); 651 result = ipsec_in_reject(sp, inp, m); 652 key_freesp(&sp); 653 if (result != 0) 654 IPSECSTAT_INC(ips_in_polvio); 655 return (result); 656 } 657 658 /* 659 * IPSEC_CAP() method implementation for IPv4. 660 */ 661 int 662 ipsec4_capability(struct mbuf *m, u_int cap) 663 { 664 665 switch (cap) { 666 case IPSEC_CAP_BYPASS_FILTER: 667 /* 668 * Bypass packet filtering for packets previously handled 669 * by IPsec. 670 */ 671 if (!V_ip4_filtertunnel && 672 m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL) 673 return (1); 674 return (0); 675 case IPSEC_CAP_OPERABLE: 676 /* Do we have active security policies? */ 677 return (key_havesp_any()); 678 }; 679 return (EOPNOTSUPP); 680 } 681 682 #endif /* INET */ 683 684 #ifdef INET6 685 static void 686 ipsec6_get_ulp(const struct mbuf *m, struct secpolicyindex *spidx, 687 int needport) 688 { 689 struct tcphdr th; 690 struct udphdr uh; 691 struct icmp6_hdr ih; 692 int off, nxt; 693 694 IPSEC_ASSERT(m->m_pkthdr.len >= sizeof(struct ip6_hdr), 695 ("packet too short")); 696 697 /* Set default. */ 698 spidx->ul_proto = IPSEC_ULPROTO_ANY; 699 spidx->src.sin6.sin6_port = IPSEC_PORT_ANY; 700 spidx->dst.sin6.sin6_port = IPSEC_PORT_ANY; 701 702 nxt = -1; 703 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt); 704 if (off < 0 || m->m_pkthdr.len < off) 705 return; 706 707 switch (nxt) { 708 case IPPROTO_TCP: 709 spidx->ul_proto = nxt; 710 if (!needport) 711 break; 712 if (off + sizeof(struct tcphdr) > m->m_pkthdr.len) 713 break; 714 m_copydata(m, off, sizeof(th), (caddr_t)&th); 715 spidx->src.sin6.sin6_port = th.th_sport; 716 spidx->dst.sin6.sin6_port = th.th_dport; 717 break; 718 case IPPROTO_UDP: 719 spidx->ul_proto = nxt; 720 if (!needport) 721 break; 722 if (off + sizeof(struct udphdr) > m->m_pkthdr.len) 723 break; 724 m_copydata(m, off, sizeof(uh), (caddr_t)&uh); 725 spidx->src.sin6.sin6_port = uh.uh_sport; 726 spidx->dst.sin6.sin6_port = uh.uh_dport; 727 break; 728 case IPPROTO_ICMPV6: 729 spidx->ul_proto = nxt; 730 if (off + sizeof(struct icmp6_hdr) > m->m_pkthdr.len) 731 break; 732 m_copydata(m, off, sizeof(ih), (caddr_t)&ih); 733 spidx->src.sin6.sin6_port = htons((uint16_t)ih.icmp6_type); 734 spidx->dst.sin6.sin6_port = htons((uint16_t)ih.icmp6_code); 735 break; 736 default: 737 /* XXX Intermediate headers??? */ 738 spidx->ul_proto = nxt; 739 break; 740 } 741 KEYDBG(IPSEC_DUMP, 742 printf("%s: ", __func__); kdebug_secpolicyindex(spidx, NULL)); 743 } 744 745 static void 746 ipsec6_setspidx_ipaddr(const struct mbuf *m, struct secpolicyindex *spidx) 747 { 748 749 ipsec6_setsockaddrs(m, &spidx->src, &spidx->dst); 750 spidx->prefs = sizeof(struct in6_addr) << 3; 751 spidx->prefd = sizeof(struct in6_addr) << 3; 752 } 753 754 static struct secpolicy * 755 ipsec6_getpolicy(const struct mbuf *m, struct inpcb *inp, u_int dir, 756 int needport) 757 { 758 struct secpolicyindex spidx; 759 struct secpolicy *sp; 760 761 sp = ipsec_getpcbpolicy(inp, dir); 762 if (sp == NULL && key_havesp(dir)) { 763 /* Make an index to look for a policy. */ 764 ipsec6_setspidx_ipaddr(m, &spidx); 765 ipsec6_get_ulp(m, &spidx, needport); 766 spidx.dir = dir; 767 sp = key_allocsp(&spidx, dir); 768 } 769 if (sp == NULL) /* No SP found, use system default. */ 770 sp = key_allocsp_default(); 771 return (sp); 772 } 773 774 /* 775 * Check security policy for *OUTBOUND* IPv6 packet. 776 */ 777 struct secpolicy * 778 ipsec6_checkpolicy(const struct mbuf *m, struct inpcb *inp, int *error, 779 int needport) 780 { 781 struct secpolicy *sp; 782 783 *error = 0; 784 sp = ipsec6_getpolicy(m, inp, IPSEC_DIR_OUTBOUND, needport); 785 if (sp != NULL) 786 sp = ipsec_checkpolicy(sp, inp, error); 787 if (sp == NULL) { 788 switch (*error) { 789 case 0: /* No IPsec required: BYPASS or NONE */ 790 break; 791 case -EINVAL: 792 IPSEC6STAT_INC(ips_out_polvio); 793 break; 794 default: 795 IPSEC6STAT_INC(ips_out_inval); 796 } 797 } 798 KEYDBG(IPSEC_STAMP, 799 printf("%s: using SP(%p), error %d\n", __func__, sp, *error)); 800 if (sp != NULL) 801 KEYDBG(IPSEC_DATA, kdebug_secpolicy(sp)); 802 return (sp); 803 } 804 805 /* 806 * Check IPv6 packet against inbound security policy. 807 * This function is called from tcp6_input(), udp6_input(), 808 * rip6_input() and sctp_input(). 809 */ 810 int 811 ipsec6_in_reject(const struct mbuf *m, struct inpcb *inp) 812 { 813 struct secpolicy *sp; 814 #ifdef IPSEC_OFFLOAD 815 struct ipsec_accel_in_tag *tag; 816 #endif 817 int result; 818 819 #ifdef IPSEC_OFFLOAD 820 tag = ipsec_accel_input_tag_lookup(m); 821 if (tag != NULL) 822 return (0); 823 #endif 824 sp = ipsec6_getpolicy(m, inp, IPSEC_DIR_INBOUND, 0); 825 result = ipsec_in_reject(sp, inp, m); 826 key_freesp(&sp); 827 if (result) 828 IPSEC6STAT_INC(ips_in_polvio); 829 return (result); 830 } 831 832 /* 833 * IPSEC_CAP() method implementation for IPv6. 834 */ 835 int 836 ipsec6_capability(struct mbuf *m, u_int cap) 837 { 838 839 switch (cap) { 840 case IPSEC_CAP_BYPASS_FILTER: 841 /* 842 * Bypass packet filtering for packets previously handled 843 * by IPsec. 844 */ 845 if (!V_ip6_filtertunnel && 846 m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL) 847 return (1); 848 return (0); 849 case IPSEC_CAP_OPERABLE: 850 /* Do we have active security policies? */ 851 return (key_havesp_any()); 852 }; 853 return (EOPNOTSUPP); 854 } 855 #endif /* INET6 */ 856 857 int 858 ipsec_run_hhooks(struct ipsec_ctx_data *ctx, int type) 859 { 860 int idx; 861 862 switch (ctx->af) { 863 #ifdef INET 864 case AF_INET: 865 idx = HHOOK_IPSEC_INET; 866 break; 867 #endif 868 #ifdef INET6 869 case AF_INET6: 870 idx = HHOOK_IPSEC_INET6; 871 break; 872 #endif 873 default: 874 return (EPFNOSUPPORT); 875 } 876 if (type == HHOOK_TYPE_IPSEC_IN) 877 HHOOKS_RUN_IF(V_ipsec_hhh_in[idx], ctx, NULL); 878 else 879 HHOOKS_RUN_IF(V_ipsec_hhh_out[idx], ctx, NULL); 880 if (*ctx->mp == NULL) 881 return (EACCES); 882 return (0); 883 } 884 885 /* 886 * Return current level. 887 * Either IPSEC_LEVEL_USE or IPSEC_LEVEL_REQUIRE are always returned. 888 */ 889 u_int 890 ipsec_get_reqlevel(struct secpolicy *sp, u_int idx) 891 { 892 struct ipsecrequest *isr; 893 u_int esp_trans_deflev, esp_net_deflev; 894 u_int ah_trans_deflev, ah_net_deflev; 895 u_int level = 0; 896 897 IPSEC_ASSERT(idx < sp->tcount, ("Wrong IPsec request index %d", idx)); 898 /* XXX Note that we have ipseclog() expanded here - code sync issue. */ 899 #define IPSEC_CHECK_DEFAULT(lev) \ 900 (((lev) != IPSEC_LEVEL_USE && (lev) != IPSEC_LEVEL_REQUIRE && \ 901 (lev) != IPSEC_LEVEL_UNIQUE) \ 902 ? (V_ipsec_debug ? \ 903 log(LOG_INFO, "fixed system default level " #lev ":%d->%d\n",\ 904 (lev), IPSEC_LEVEL_REQUIRE) : 0), \ 905 (lev) = IPSEC_LEVEL_REQUIRE, (lev) : (lev)) 906 907 /* 908 * IPsec VTI uses unique security policy with fake spidx filled 909 * with zeroes. Just return IPSEC_LEVEL_REQUIRE instead of doing 910 * full level lookup for such policies. 911 */ 912 if (sp->state == IPSEC_SPSTATE_IFNET) { 913 IPSEC_ASSERT(sp->req[idx]->level == IPSEC_LEVEL_UNIQUE, 914 ("Wrong IPsec request level %d", sp->req[idx]->level)); 915 return (IPSEC_LEVEL_REQUIRE); 916 } 917 918 /* Set default level. */ 919 switch (sp->spidx.src.sa.sa_family) { 920 #ifdef INET 921 case AF_INET: 922 esp_trans_deflev = IPSEC_CHECK_DEFAULT(V_ip4_esp_trans_deflev); 923 esp_net_deflev = IPSEC_CHECK_DEFAULT(V_ip4_esp_net_deflev); 924 ah_trans_deflev = IPSEC_CHECK_DEFAULT(V_ip4_ah_trans_deflev); 925 ah_net_deflev = IPSEC_CHECK_DEFAULT(V_ip4_ah_net_deflev); 926 break; 927 #endif 928 #ifdef INET6 929 case AF_INET6: 930 esp_trans_deflev = IPSEC_CHECK_DEFAULT(V_ip6_esp_trans_deflev); 931 esp_net_deflev = IPSEC_CHECK_DEFAULT(V_ip6_esp_net_deflev); 932 ah_trans_deflev = IPSEC_CHECK_DEFAULT(V_ip6_ah_trans_deflev); 933 ah_net_deflev = IPSEC_CHECK_DEFAULT(V_ip6_ah_net_deflev); 934 break; 935 #endif /* INET6 */ 936 default: 937 panic("%s: unknown af %u", 938 __func__, sp->spidx.src.sa.sa_family); 939 } 940 941 #undef IPSEC_CHECK_DEFAULT 942 943 isr = sp->req[idx]; 944 /* Set level. */ 945 switch (isr->level) { 946 case IPSEC_LEVEL_DEFAULT: 947 switch (isr->saidx.proto) { 948 case IPPROTO_ESP: 949 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) 950 level = esp_net_deflev; 951 else 952 level = esp_trans_deflev; 953 break; 954 case IPPROTO_AH: 955 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) 956 level = ah_net_deflev; 957 else 958 level = ah_trans_deflev; 959 break; 960 case IPPROTO_IPCOMP: 961 /* 962 * We don't really care, as IPcomp document says that 963 * we shouldn't compress small packets. 964 */ 965 level = IPSEC_LEVEL_USE; 966 break; 967 default: 968 panic("%s: Illegal protocol defined %u\n", __func__, 969 isr->saidx.proto); 970 } 971 break; 972 973 case IPSEC_LEVEL_USE: 974 case IPSEC_LEVEL_REQUIRE: 975 level = isr->level; 976 break; 977 case IPSEC_LEVEL_UNIQUE: 978 level = IPSEC_LEVEL_REQUIRE; 979 break; 980 981 default: 982 panic("%s: Illegal IPsec level %u\n", __func__, isr->level); 983 } 984 985 return (level); 986 } 987 988 static int 989 ipsec_check_history(const struct mbuf *m, struct secpolicy *sp, u_int idx) 990 { 991 struct xform_history *xh; 992 struct m_tag *mtag; 993 994 mtag = NULL; 995 while ((mtag = m_tag_find(__DECONST(struct mbuf *, m), 996 PACKET_TAG_IPSEC_IN_DONE, mtag)) != NULL) { 997 xh = (struct xform_history *)(mtag + 1); 998 KEYDBG(IPSEC_DATA, 999 char buf[IPSEC_ADDRSTRLEN]; 1000 printf("%s: mode %s proto %u dst %s\n", __func__, 1001 kdebug_secasindex_mode(xh->mode), xh->proto, 1002 ipsec_address(&xh->dst, buf, sizeof(buf)))); 1003 if (xh->proto != sp->req[idx]->saidx.proto) 1004 continue; 1005 /* If SA had IPSEC_MODE_ANY, consider this as match. */ 1006 if (xh->mode != sp->req[idx]->saidx.mode && 1007 xh->mode != IPSEC_MODE_ANY) 1008 continue; 1009 /* 1010 * For transport mode IPsec request doesn't contain 1011 * addresses. We need to use address from spidx. 1012 */ 1013 if (sp->req[idx]->saidx.mode == IPSEC_MODE_TRANSPORT) { 1014 if (key_sockaddrcmp_withmask(&xh->dst.sa, 1015 &sp->spidx.dst.sa, sp->spidx.prefd) != 0) 1016 continue; 1017 } else { 1018 if (key_sockaddrcmp(&xh->dst.sa, 1019 &sp->req[idx]->saidx.dst.sa, 0) != 0) 1020 continue; 1021 } 1022 return (0); /* matched */ 1023 } 1024 return (1); 1025 } 1026 1027 /* 1028 * Check security policy requirements against the actual 1029 * packet contents. Return one if the packet should be 1030 * rejected as "invalid"; otherwise return zero to have the 1031 * packet treated as "valid". 1032 * 1033 * OUT: 1034 * 0: valid 1035 * 1: invalid 1036 */ 1037 static int 1038 ipsec_in_reject(struct secpolicy *sp, struct inpcb *inp, const struct mbuf *m) 1039 { 1040 int i; 1041 1042 KEYDBG(IPSEC_STAMP, 1043 printf("%s: PCB(%p): using SP(%p)\n", __func__, inp, sp)); 1044 KEYDBG(IPSEC_DATA, kdebug_secpolicy(sp)); 1045 1046 if (inp != NULL && inp->inp_sp != NULL && inp->inp_sp->sp_in == NULL) 1047 ipsec_cachepolicy(inp, sp, IPSEC_DIR_INBOUND); 1048 1049 /* Check policy. */ 1050 switch (sp->policy) { 1051 case IPSEC_POLICY_DISCARD: 1052 return (1); 1053 case IPSEC_POLICY_BYPASS: 1054 case IPSEC_POLICY_NONE: 1055 return (0); 1056 } 1057 1058 IPSEC_ASSERT(sp->policy == IPSEC_POLICY_IPSEC, 1059 ("invalid policy %u", sp->policy)); 1060 1061 /* 1062 * ipsec[46]_common_input_cb after each transform adds 1063 * PACKET_TAG_IPSEC_IN_DONE mbuf tag. It contains SPI, proto, mode 1064 * and destination address from saidx. We can compare info from 1065 * these tags with requirements in SP. 1066 */ 1067 for (i = 0; i < sp->tcount; i++) { 1068 /* 1069 * Do not check IPcomp, since IPcomp document 1070 * says that we shouldn't compress small packets. 1071 * IPComp policy should always be treated as being 1072 * in "use" level. 1073 */ 1074 if (sp->req[i]->saidx.proto == IPPROTO_IPCOMP || 1075 ipsec_get_reqlevel(sp, i) != IPSEC_LEVEL_REQUIRE) 1076 continue; 1077 if (V_check_policy_history != 0 && 1078 ipsec_check_history(m, sp, i) != 0) 1079 return (1); 1080 else switch (sp->req[i]->saidx.proto) { 1081 case IPPROTO_ESP: 1082 if ((m->m_flags & M_DECRYPTED) == 0) { 1083 KEYDBG(IPSEC_DUMP, 1084 printf("%s: ESP m_flags:%x\n", __func__, 1085 m->m_flags)); 1086 return (1); 1087 } 1088 break; 1089 case IPPROTO_AH: 1090 if ((m->m_flags & M_AUTHIPHDR) == 0) { 1091 KEYDBG(IPSEC_DUMP, 1092 printf("%s: AH m_flags:%x\n", __func__, 1093 m->m_flags)); 1094 return (1); 1095 } 1096 break; 1097 } 1098 } 1099 return (0); /* Valid. */ 1100 } 1101 1102 /* 1103 * Compute the byte size to be occupied by IPsec header. 1104 * In case it is tunnelled, it includes the size of outer IP header. 1105 */ 1106 size_t 1107 ipsec_hdrsiz_internal(struct secpolicy *sp) 1108 { 1109 size_t size; 1110 int i; 1111 1112 KEYDBG(IPSEC_STAMP, printf("%s: using SP(%p)\n", __func__, sp)); 1113 KEYDBG(IPSEC_DATA, kdebug_secpolicy(sp)); 1114 1115 switch (sp->policy) { 1116 case IPSEC_POLICY_DISCARD: 1117 case IPSEC_POLICY_BYPASS: 1118 case IPSEC_POLICY_NONE: 1119 return (0); 1120 } 1121 1122 IPSEC_ASSERT(sp->policy == IPSEC_POLICY_IPSEC, 1123 ("invalid policy %u", sp->policy)); 1124 1125 /* 1126 * XXX: for each transform we need to lookup suitable SA 1127 * and use info from SA to calculate headers size. 1128 * XXX: for NAT-T we need to cosider UDP header size. 1129 */ 1130 size = 0; 1131 for (i = 0; i < sp->tcount; i++) { 1132 switch (sp->req[i]->saidx.proto) { 1133 case IPPROTO_ESP: 1134 size += esp_hdrsiz(NULL); 1135 break; 1136 case IPPROTO_AH: 1137 size += ah_hdrsiz(NULL); 1138 break; 1139 case IPPROTO_IPCOMP: 1140 size += sizeof(struct ipcomp); 1141 break; 1142 } 1143 1144 if (sp->req[i]->saidx.mode == IPSEC_MODE_TUNNEL) { 1145 switch (sp->req[i]->saidx.dst.sa.sa_family) { 1146 #ifdef INET 1147 case AF_INET: 1148 size += sizeof(struct ip); 1149 break; 1150 #endif 1151 #ifdef INET6 1152 case AF_INET6: 1153 size += sizeof(struct ip6_hdr); 1154 break; 1155 #endif 1156 default: 1157 ipseclog((LOG_ERR, "%s: unknown AF %d in " 1158 "IPsec tunnel SA\n", __func__, 1159 sp->req[i]->saidx.dst.sa.sa_family)); 1160 break; 1161 } 1162 } 1163 } 1164 return (size); 1165 } 1166 1167 /* 1168 * Compute ESP/AH header size for protocols with PCB, including 1169 * outer IP header. Currently only tcp_output() uses it. 1170 */ 1171 size_t 1172 ipsec_hdrsiz_inpcb(struct inpcb *inp) 1173 { 1174 struct secpolicyindex spidx; 1175 struct secpolicy *sp; 1176 size_t sz; 1177 1178 sp = ipsec_getpcbpolicy(inp, IPSEC_DIR_OUTBOUND); 1179 if (sp == NULL && key_havesp(IPSEC_DIR_OUTBOUND)) { 1180 ipsec_setspidx_inpcb(inp, &spidx, IPSEC_DIR_OUTBOUND); 1181 sp = key_allocsp(&spidx, IPSEC_DIR_OUTBOUND); 1182 } 1183 if (sp == NULL) 1184 sp = key_allocsp_default(); 1185 sz = ipsec_hdrsiz_internal(sp); 1186 key_freesp(&sp); 1187 return (sz); 1188 } 1189 1190 1191 #define IPSEC_BITMAP_INDEX_MASK(w) (w - 1) 1192 #define IPSEC_REDUNDANT_BIT_SHIFTS 5 1193 #define IPSEC_REDUNDANT_BITS (1 << IPSEC_REDUNDANT_BIT_SHIFTS) 1194 #define IPSEC_BITMAP_LOC_MASK (IPSEC_REDUNDANT_BITS - 1) 1195 1196 /* 1197 * Functions below are responsible for checking and updating bitmap. 1198 * These are used to separate ipsec_chkreplay() and ipsec_updatereplay() 1199 * from window implementation 1200 * 1201 * Based on RFC 6479. Blocks are 32 bits unsigned integers 1202 */ 1203 1204 static inline int 1205 check_window(const struct secreplay *replay, uint64_t seq) 1206 { 1207 int index, bit_location; 1208 1209 SECREPLAY_ASSERT(replay); 1210 1211 bit_location = seq & IPSEC_BITMAP_LOC_MASK; 1212 index = (seq >> IPSEC_REDUNDANT_BIT_SHIFTS) 1213 & IPSEC_BITMAP_INDEX_MASK(replay->bitmap_size); 1214 1215 /* This packet already seen? */ 1216 return ((replay->bitmap)[index] & (1 << bit_location)); 1217 } 1218 1219 static inline void 1220 advance_window(const struct secreplay *replay, uint64_t seq) 1221 { 1222 int i; 1223 uint64_t index, index_cur, diff; 1224 1225 SECREPLAY_ASSERT(replay); 1226 1227 index_cur = replay->last >> IPSEC_REDUNDANT_BIT_SHIFTS; 1228 index = seq >> IPSEC_REDUNDANT_BIT_SHIFTS; 1229 diff = index - index_cur; 1230 1231 if (diff > replay->bitmap_size) { 1232 /* something unusual in this case */ 1233 diff = replay->bitmap_size; 1234 } 1235 1236 for (i = 0; i < diff; i++) { 1237 replay->bitmap[(i + index_cur + 1) 1238 & IPSEC_BITMAP_INDEX_MASK(replay->bitmap_size)] = 0; 1239 } 1240 } 1241 1242 static inline void 1243 set_window(const struct secreplay *replay, uint64_t seq) 1244 { 1245 int index, bit_location; 1246 1247 SECREPLAY_ASSERT(replay); 1248 1249 bit_location = seq & IPSEC_BITMAP_LOC_MASK; 1250 index = (seq >> IPSEC_REDUNDANT_BIT_SHIFTS) 1251 & IPSEC_BITMAP_INDEX_MASK(replay->bitmap_size); 1252 1253 replay->bitmap[index] |= (1 << bit_location); 1254 } 1255 1256 /* 1257 * Check the variable replay window. 1258 * ipsec_chkreplay() performs replay check before ICV verification. 1259 * ipsec_updatereplay() updates replay bitmap. This must be called after 1260 * ICV verification (it also performs replay check, which is usually done 1261 * beforehand). 1262 * 0 (zero) is returned if packet disallowed, 1 if packet permitted. 1263 * 1264 * Based on RFC 4303 1265 */ 1266 1267 int 1268 ipsec_chkreplay(uint32_t seq, uint32_t *seqhigh, struct secasvar *sav) 1269 { 1270 char buf[128]; 1271 struct secreplay *replay; 1272 uint32_t window; 1273 uint32_t tl, th, bl; 1274 uint32_t seqh; 1275 1276 IPSEC_ASSERT(sav != NULL, ("Null SA")); 1277 IPSEC_ASSERT(sav->replay != NULL, ("Null replay state")); 1278 1279 replay = sav->replay; 1280 1281 /* No need to check replay if disabled. */ 1282 if (replay->wsize == 0) { 1283 return (1); 1284 } 1285 1286 SECREPLAY_LOCK(replay); 1287 1288 /* Zero sequence number is not allowed. */ 1289 if (seq == 0 && replay->last == 0) { 1290 SECREPLAY_UNLOCK(replay); 1291 return (0); 1292 } 1293 1294 window = replay->wsize << 3; /* Size of window */ 1295 tl = (uint32_t)replay->last; /* Top of window, lower part */ 1296 th = (uint32_t)(replay->last >> 32); /* Top of window, high part */ 1297 bl = tl - window + 1; /* Bottom of window, lower part */ 1298 1299 /* 1300 * We keep the high part intact when: 1301 * 1) the seq is within [bl, 0xffffffff] and the whole window is 1302 * within one subspace; 1303 * 2) the seq is within [0, bl) and window spans two subspaces. 1304 */ 1305 if ((tl >= window - 1 && seq >= bl) || 1306 (tl < window - 1 && seq < bl)) { 1307 *seqhigh = th; 1308 if (seq <= tl) { 1309 /* Sequence number inside window - check against replay */ 1310 if (check_window(replay, seq)) { 1311 SECREPLAY_UNLOCK(replay); 1312 return (0); 1313 } 1314 } 1315 1316 SECREPLAY_UNLOCK(replay); 1317 /* Sequence number above top of window or not found in bitmap */ 1318 return (1); 1319 } 1320 1321 /* 1322 * If ESN is not enabled and packet with highest sequence number 1323 * was received we should report overflow 1324 */ 1325 if (tl == 0xffffffff && !(sav->flags & SADB_X_SAFLAGS_ESN)) { 1326 /* Set overflow flag. */ 1327 replay->overflow++; 1328 1329 if ((sav->flags & SADB_X_EXT_CYCSEQ) == 0) { 1330 if (sav->sah->saidx.proto == IPPROTO_ESP) 1331 ESPSTAT_INC(esps_wrap); 1332 else if (sav->sah->saidx.proto == IPPROTO_AH) 1333 AHSTAT_INC(ahs_wrap); 1334 SECREPLAY_UNLOCK(replay); 1335 return (0); 1336 } 1337 1338 ipseclog((LOG_WARNING, "%s: replay counter made %d cycle. %s\n", 1339 __func__, replay->overflow, 1340 ipsec_sa2str(sav, buf, sizeof(buf)))); 1341 } 1342 1343 /* 1344 * Seq is within [bl, 0xffffffff] and bl is within 1345 * [0xffffffff-window, 0xffffffff]. This means we got a seq 1346 * which is within our replay window, but in the previous 1347 * subspace. 1348 */ 1349 if (tl < window - 1 && seq >= bl) { 1350 if (th == 0) 1351 return (0); 1352 *seqhigh = th - 1; 1353 seqh = th - 1; 1354 if (check_window(replay, seq)) { 1355 SECREPLAY_UNLOCK(replay); 1356 return (0); 1357 } 1358 SECREPLAY_UNLOCK(replay); 1359 return (1); 1360 } 1361 1362 /* 1363 * Seq is within [0, bl) but the whole window is within one subspace. 1364 * This means that seq has wrapped and is in next subspace 1365 */ 1366 *seqhigh = th + 1; 1367 seqh = th + 1; 1368 1369 /* Don't let high part wrap. */ 1370 if (seqh == 0) { 1371 /* Set overflow flag. */ 1372 replay->overflow++; 1373 1374 if ((sav->flags & SADB_X_EXT_CYCSEQ) == 0) { 1375 if (sav->sah->saidx.proto == IPPROTO_ESP) 1376 ESPSTAT_INC(esps_wrap); 1377 else if (sav->sah->saidx.proto == IPPROTO_AH) 1378 AHSTAT_INC(ahs_wrap); 1379 SECREPLAY_UNLOCK(replay); 1380 return (0); 1381 } 1382 1383 ipseclog((LOG_WARNING, "%s: replay counter made %d cycle. %s\n", 1384 __func__, replay->overflow, 1385 ipsec_sa2str(sav, buf, sizeof(buf)))); 1386 } 1387 1388 SECREPLAY_UNLOCK(replay); 1389 return (1); 1390 } 1391 1392 /* 1393 * Check replay counter whether to update or not. 1394 * OUT: 0: OK 1395 * 1: NG 1396 */ 1397 int 1398 ipsec_updatereplay(uint32_t seq, struct secasvar *sav) 1399 { 1400 struct secreplay *replay; 1401 uint32_t window; 1402 uint32_t tl, th, bl; 1403 uint32_t seqh; 1404 1405 IPSEC_ASSERT(sav != NULL, ("Null SA")); 1406 IPSEC_ASSERT(sav->replay != NULL, ("Null replay state")); 1407 1408 replay = sav->replay; 1409 1410 /* No need to check replay if disabled. */ 1411 if (replay->wsize == 0) 1412 return (0); 1413 1414 SECREPLAY_LOCK(replay); 1415 1416 /* Zero sequence number is not allowed. */ 1417 if (seq == 0 && replay->last == 0) { 1418 SECREPLAY_UNLOCK(replay); 1419 return (1); 1420 } 1421 1422 window = replay->wsize << 3; /* Size of window */ 1423 tl = (uint32_t)replay->last; /* Top of window, lower part */ 1424 th = (uint32_t)(replay->last >> 32); /* Top of window, high part */ 1425 bl = tl - window + 1; /* Bottom of window, lower part */ 1426 1427 /* 1428 * We keep the high part intact when: 1429 * 1) the seq is within [bl, 0xffffffff] and the whole window is 1430 * within one subspace; 1431 * 2) the seq is within [0, bl) and window spans two subspaces. 1432 */ 1433 if ((tl >= window - 1 && seq >= bl) || 1434 (tl < window - 1 && seq < bl)) { 1435 seqh = th; 1436 if (seq <= tl) { 1437 /* Sequence number inside window - check against replay */ 1438 if (check_window(replay, seq)) { 1439 SECREPLAY_UNLOCK(replay); 1440 return (1); 1441 } 1442 set_window(replay, seq); 1443 } else { 1444 advance_window(replay, ((uint64_t)seqh << 32) | seq); 1445 set_window(replay, seq); 1446 replay->last = ((uint64_t)seqh << 32) | seq; 1447 } 1448 1449 /* Sequence number above top of window or not found in bitmap */ 1450 replay->count++; 1451 SECREPLAY_UNLOCK(replay); 1452 return (0); 1453 } 1454 1455 if (!(sav->flags & SADB_X_SAFLAGS_ESN)) { 1456 SECREPLAY_UNLOCK(replay); 1457 return (1); 1458 } 1459 1460 /* 1461 * Seq is within [bl, 0xffffffff] and bl is within 1462 * [0xffffffff-window, 0xffffffff]. This means we got a seq 1463 * which is within our replay window, but in the previous 1464 * subspace. 1465 */ 1466 if (tl < window - 1 && seq >= bl) { 1467 if (th == 0) { 1468 SECREPLAY_UNLOCK(replay); 1469 return (1); 1470 } 1471 if (check_window(replay, seq)) { 1472 SECREPLAY_UNLOCK(replay); 1473 return (1); 1474 } 1475 1476 set_window(replay, seq); 1477 replay->count++; 1478 SECREPLAY_UNLOCK(replay); 1479 return (0); 1480 } 1481 1482 /* 1483 * Seq is within [0, bl) but the whole window is within one subspace. 1484 * This means that seq has wrapped and is in next subspace 1485 */ 1486 seqh = th + 1; 1487 1488 /* Don't let high part wrap. */ 1489 if (seqh == 0) { 1490 SECREPLAY_UNLOCK(replay); 1491 return (1); 1492 } 1493 1494 advance_window(replay, ((uint64_t)seqh << 32) | seq); 1495 set_window(replay, seq); 1496 replay->last = ((uint64_t)seqh << 32) | seq; 1497 replay->count++; 1498 1499 SECREPLAY_UNLOCK(replay); 1500 return (0); 1501 } 1502 int 1503 ipsec_updateid(struct secasvar *sav, crypto_session_t *new, 1504 crypto_session_t *old) 1505 { 1506 crypto_session_t tmp; 1507 1508 /* 1509 * tdb_cryptoid is initialized by xform_init(). 1510 * Then it can be changed only when some crypto error occurred or 1511 * when SA is deleted. We stored used cryptoid in the xform_data 1512 * structure. In case when crypto error occurred and crypto 1513 * subsystem has reinited the session, it returns new cryptoid 1514 * and EAGAIN error code. 1515 * 1516 * This function will be called when we got EAGAIN from crypto 1517 * subsystem. 1518 * *new is cryptoid that was returned by crypto subsystem in 1519 * the crp_sid. 1520 * *old is the original cryptoid that we stored in xform_data. 1521 * 1522 * For first failed request *old == sav->tdb_cryptoid, then 1523 * we update sav->tdb_cryptoid and redo crypto_dispatch(). 1524 * For next failed request *old != sav->tdb_cryptoid, then 1525 * we store cryptoid from first request into the *new variable 1526 * and crp_sid from this second session will be returned via 1527 * *old pointer, so caller can release second session. 1528 * 1529 * XXXAE: check this more carefully. 1530 */ 1531 KEYDBG(IPSEC_STAMP, 1532 printf("%s: SA(%p) moves cryptoid %p -> %p\n", 1533 __func__, sav, *old, *new)); 1534 KEYDBG(IPSEC_DATA, kdebug_secasv(sav)); 1535 SECASVAR_WLOCK(sav); 1536 if (sav->tdb_cryptoid != *old) { 1537 /* cryptoid was already updated */ 1538 tmp = *new; 1539 *new = sav->tdb_cryptoid; 1540 *old = tmp; 1541 SECASVAR_WUNLOCK(sav); 1542 return (1); 1543 } 1544 sav->tdb_cryptoid = *new; 1545 SECASVAR_WUNLOCK(sav); 1546 return (0); 1547 } 1548 1549 int 1550 ipsec_initialized(void) 1551 { 1552 1553 return (V_def_policy != NULL); 1554 } 1555 1556 static void 1557 def_policy_init(const void *unused __unused) 1558 { 1559 1560 V_def_policy = key_newsp(); 1561 if (V_def_policy != NULL) { 1562 V_def_policy->policy = IPSEC_POLICY_NONE; 1563 /* Force INPCB SP cache invalidation */ 1564 key_bumpspgen(); 1565 } else 1566 printf("%s: failed to initialize default policy\n", __func__); 1567 } 1568 1569 static void 1570 def_policy_uninit(const void *unused __unused) 1571 { 1572 1573 if (V_def_policy != NULL) { 1574 key_freesp(&V_def_policy); 1575 key_bumpspgen(); 1576 } 1577 } 1578 1579 VNET_SYSINIT(def_policy_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_FIRST, 1580 def_policy_init, NULL); 1581 VNET_SYSUNINIT(def_policy_uninit, SI_SUB_PROTO_DOMAIN, SI_ORDER_FIRST, 1582 def_policy_uninit, NULL); 1583