1 /* $FreeBSD$ */ 2 /* $KAME: ipsec.c,v 1.103 2001/05/24 07:14:18 sakane Exp $ */ 3 4 /*- 5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the project nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 /* 34 * IPsec controller part. 35 */ 36 37 #include "opt_inet.h" 38 #include "opt_inet6.h" 39 #include "opt_ipsec.h" 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/malloc.h> 44 #include <sys/mbuf.h> 45 #include <sys/domain.h> 46 #include <sys/priv.h> 47 #include <sys/protosw.h> 48 #include <sys/socket.h> 49 #include <sys/socketvar.h> 50 #include <sys/errno.h> 51 #include <sys/hhook.h> 52 #include <sys/time.h> 53 #include <sys/kernel.h> 54 #include <sys/syslog.h> 55 #include <sys/sysctl.h> 56 #include <sys/proc.h> 57 58 #include <net/if.h> 59 #include <net/if_enc.h> 60 #include <net/if_var.h> 61 #include <net/vnet.h> 62 63 #include <netinet/in.h> 64 #include <netinet/in_systm.h> 65 #include <netinet/ip.h> 66 #include <netinet/ip_var.h> 67 #include <netinet/in_var.h> 68 #include <netinet/udp.h> 69 #include <netinet/udp_var.h> 70 #include <netinet/tcp.h> 71 #include <netinet/udp.h> 72 73 #include <netinet/ip6.h> 74 #ifdef INET6 75 #include <netinet6/ip6_var.h> 76 #endif 77 #include <netinet/in_pcb.h> 78 #ifdef INET6 79 #include <netinet/icmp6.h> 80 #endif 81 82 #include <sys/types.h> 83 #include <netipsec/ipsec.h> 84 #ifdef INET6 85 #include <netipsec/ipsec6.h> 86 #endif 87 #include <netipsec/ah_var.h> 88 #include <netipsec/esp_var.h> 89 #include <netipsec/ipcomp.h> /*XXX*/ 90 #include <netipsec/ipcomp_var.h> 91 #include <netipsec/ipsec_support.h> 92 93 #include <netipsec/key.h> 94 #include <netipsec/keydb.h> 95 #include <netipsec/key_debug.h> 96 97 #include <netipsec/xform.h> 98 99 #include <machine/in_cksum.h> 100 101 #include <opencrypto/cryptodev.h> 102 103 /* NB: name changed so netstat doesn't use it. */ 104 VNET_PCPUSTAT_DEFINE(struct ipsecstat, ipsec4stat); 105 VNET_PCPUSTAT_SYSINIT(ipsec4stat); 106 107 #ifdef VIMAGE 108 VNET_PCPUSTAT_SYSUNINIT(ipsec4stat); 109 #endif /* VIMAGE */ 110 111 VNET_DEFINE(int, ip4_ah_offsetmask) = 0; /* maybe IP_DF? */ 112 /* DF bit on encap. 0: clear 1: set 2: copy */ 113 VNET_DEFINE(int, ip4_ipsec_dfbit) = 0; 114 VNET_DEFINE(int, ip4_esp_trans_deflev) = IPSEC_LEVEL_USE; 115 VNET_DEFINE(int, ip4_esp_net_deflev) = IPSEC_LEVEL_USE; 116 VNET_DEFINE(int, ip4_ah_trans_deflev) = IPSEC_LEVEL_USE; 117 VNET_DEFINE(int, ip4_ah_net_deflev) = IPSEC_LEVEL_USE; 118 /* ECN ignore(-1)/forbidden(0)/allowed(1) */ 119 VNET_DEFINE(int, ip4_ipsec_ecn) = 0; 120 VNET_DEFINE(int, ip4_esp_randpad) = -1; 121 122 static VNET_DEFINE(int, ip4_filtertunnel) = 0; 123 #define V_ip4_filtertunnel VNET(ip4_filtertunnel) 124 static VNET_DEFINE(int, check_policy_history) = 0; 125 #define V_check_policy_history VNET(check_policy_history) 126 static VNET_DEFINE(struct secpolicy *, def_policy) = NULL; 127 #define V_def_policy VNET(def_policy) 128 static int 129 sysctl_def_policy(SYSCTL_HANDLER_ARGS) 130 { 131 int error, value; 132 133 value = V_def_policy->policy; 134 error = sysctl_handle_int(oidp, &value, 0, req); 135 if (error == 0) { 136 if (value != IPSEC_POLICY_DISCARD && 137 value != IPSEC_POLICY_NONE) 138 return (EINVAL); 139 V_def_policy->policy = value; 140 } 141 return (error); 142 } 143 144 /* 145 * Crypto support requirements: 146 * 147 * 1 require hardware support 148 * -1 require software support 149 * 0 take anything 150 */ 151 VNET_DEFINE(int, crypto_support) = CRYPTOCAP_F_HARDWARE | CRYPTOCAP_F_SOFTWARE; 152 /* 153 * TCP/UDP checksum handling policy for transport mode NAT-T (RFC3948) 154 * 155 * 0 - auto: incrementally recompute, when checksum delta is known; 156 * if checksum delta isn't known, reset checksum to zero for UDP, 157 * and mark csum_flags as valid for TCP. 158 * 1 - fully recompute TCP/UDP checksum. 159 */ 160 VNET_DEFINE(int, natt_cksum_policy) = 0; 161 162 FEATURE(ipsec, "Internet Protocol Security (IPsec)"); 163 FEATURE(ipsec_natt, "UDP Encapsulation of IPsec ESP Packets ('NAT-T')"); 164 165 SYSCTL_DECL(_net_inet_ipsec); 166 167 /* net.inet.ipsec */ 168 SYSCTL_PROC(_net_inet_ipsec, IPSECCTL_DEF_POLICY, def_policy, 169 CTLTYPE_INT | CTLFLAG_VNET | CTLFLAG_RW, 0, 0, sysctl_def_policy, "I", 170 "IPsec default policy."); 171 SYSCTL_INT(_net_inet_ipsec, IPSECCTL_DEF_ESP_TRANSLEV, esp_trans_deflev, 172 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip4_esp_trans_deflev), 0, 173 "Default ESP transport mode level"); 174 SYSCTL_INT(_net_inet_ipsec, IPSECCTL_DEF_ESP_NETLEV, esp_net_deflev, 175 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip4_esp_net_deflev), 0, 176 "Default ESP tunnel mode level."); 177 SYSCTL_INT(_net_inet_ipsec, IPSECCTL_DEF_AH_TRANSLEV, ah_trans_deflev, 178 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip4_ah_trans_deflev), 0, 179 "AH transfer mode default level."); 180 SYSCTL_INT(_net_inet_ipsec, IPSECCTL_DEF_AH_NETLEV, ah_net_deflev, 181 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip4_ah_net_deflev), 0, 182 "AH tunnel mode default level."); 183 SYSCTL_INT(_net_inet_ipsec, IPSECCTL_AH_CLEARTOS, ah_cleartos, 184 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ah_cleartos), 0, 185 "If set, clear type-of-service field when doing AH computation."); 186 SYSCTL_INT(_net_inet_ipsec, IPSECCTL_AH_OFFSETMASK, ah_offsetmask, 187 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip4_ah_offsetmask), 0, 188 "If not set, clear offset field mask when doing AH computation."); 189 SYSCTL_INT(_net_inet_ipsec, IPSECCTL_DFBIT, dfbit, 190 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip4_ipsec_dfbit), 0, 191 "Do not fragment bit on encap."); 192 SYSCTL_INT(_net_inet_ipsec, IPSECCTL_ECN, ecn, 193 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip4_ipsec_ecn), 0, 194 "Explicit Congestion Notification handling."); 195 SYSCTL_INT(_net_inet_ipsec, OID_AUTO, crypto_support, 196 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(crypto_support), 0, 197 "Crypto driver selection."); 198 SYSCTL_INT(_net_inet_ipsec, OID_AUTO, check_policy_history, 199 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(check_policy_history), 0, 200 "Use strict check of inbound packets to security policy compliance."); 201 SYSCTL_INT(_net_inet_ipsec, OID_AUTO, natt_cksum_policy, 202 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(natt_cksum_policy), 0, 203 "Method to fix TCP/UDP checksum for transport mode IPsec after NAT."); 204 SYSCTL_INT(_net_inet_ipsec, OID_AUTO, filtertunnel, 205 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip4_filtertunnel), 0, 206 "If set, filter packets from an IPsec tunnel."); 207 SYSCTL_VNET_PCPUSTAT(_net_inet_ipsec, OID_AUTO, ipsecstats, struct ipsecstat, 208 ipsec4stat, "IPsec IPv4 statistics."); 209 210 #ifdef REGRESSION 211 /* 212 * When set to 1, IPsec will send packets with the same sequence number. 213 * This allows to verify if the other side has proper replay attacks detection. 214 */ 215 VNET_DEFINE(int, ipsec_replay) = 0; 216 SYSCTL_INT(_net_inet_ipsec, OID_AUTO, test_replay, 217 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ipsec_replay), 0, 218 "Emulate replay attack"); 219 /* 220 * When set 1, IPsec will send packets with corrupted HMAC. 221 * This allows to verify if the other side properly detects modified packets. 222 */ 223 VNET_DEFINE(int, ipsec_integrity) = 0; 224 SYSCTL_INT(_net_inet_ipsec, OID_AUTO, test_integrity, 225 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ipsec_integrity), 0, 226 "Emulate man-in-the-middle attack"); 227 #endif 228 229 #ifdef INET6 230 VNET_PCPUSTAT_DEFINE(struct ipsecstat, ipsec6stat); 231 VNET_PCPUSTAT_SYSINIT(ipsec6stat); 232 233 #ifdef VIMAGE 234 VNET_PCPUSTAT_SYSUNINIT(ipsec6stat); 235 #endif /* VIMAGE */ 236 237 VNET_DEFINE(int, ip6_esp_trans_deflev) = IPSEC_LEVEL_USE; 238 VNET_DEFINE(int, ip6_esp_net_deflev) = IPSEC_LEVEL_USE; 239 VNET_DEFINE(int, ip6_ah_trans_deflev) = IPSEC_LEVEL_USE; 240 VNET_DEFINE(int, ip6_ah_net_deflev) = IPSEC_LEVEL_USE; 241 VNET_DEFINE(int, ip6_ipsec_ecn) = 0; /* ECN ignore(-1)/forbidden(0)/allowed(1) */ 242 243 static VNET_DEFINE(int, ip6_filtertunnel) = 0; 244 #define V_ip6_filtertunnel VNET(ip6_filtertunnel) 245 246 SYSCTL_DECL(_net_inet6_ipsec6); 247 248 /* net.inet6.ipsec6 */ 249 SYSCTL_PROC(_net_inet6_ipsec6, IPSECCTL_DEF_POLICY, def_policy, 250 CTLTYPE_INT | CTLFLAG_VNET | CTLFLAG_RW, 0, 0, sysctl_def_policy, "I", 251 "IPsec default policy."); 252 SYSCTL_INT(_net_inet6_ipsec6, IPSECCTL_DEF_ESP_TRANSLEV, esp_trans_deflev, 253 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip6_esp_trans_deflev), 0, 254 "Default ESP transport mode level."); 255 SYSCTL_INT(_net_inet6_ipsec6, IPSECCTL_DEF_ESP_NETLEV, esp_net_deflev, 256 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip6_esp_net_deflev), 0, 257 "Default ESP tunnel mode level."); 258 SYSCTL_INT(_net_inet6_ipsec6, IPSECCTL_DEF_AH_TRANSLEV, ah_trans_deflev, 259 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip6_ah_trans_deflev), 0, 260 "AH transfer mode default level."); 261 SYSCTL_INT(_net_inet6_ipsec6, IPSECCTL_DEF_AH_NETLEV, ah_net_deflev, 262 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip6_ah_net_deflev), 0, 263 "AH tunnel mode default level."); 264 SYSCTL_INT(_net_inet6_ipsec6, IPSECCTL_ECN, ecn, 265 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip6_ipsec_ecn), 0, 266 "Explicit Congestion Notification handling."); 267 SYSCTL_INT(_net_inet6_ipsec6, OID_AUTO, filtertunnel, 268 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip6_filtertunnel), 0, 269 "If set, filter packets from an IPsec tunnel."); 270 SYSCTL_VNET_PCPUSTAT(_net_inet6_ipsec6, IPSECCTL_STATS, ipsecstats, 271 struct ipsecstat, ipsec6stat, "IPsec IPv6 statistics."); 272 #endif /* INET6 */ 273 274 static int ipsec_in_reject(struct secpolicy *, struct inpcb *, 275 const struct mbuf *); 276 277 #ifdef INET 278 static void ipsec4_get_ulp(const struct mbuf *, struct secpolicyindex *, int); 279 static void ipsec4_setspidx_ipaddr(const struct mbuf *, 280 struct secpolicyindex *); 281 #endif 282 #ifdef INET6 283 static void ipsec6_get_ulp(const struct mbuf *m, struct secpolicyindex *, int); 284 static void ipsec6_setspidx_ipaddr(const struct mbuf *, 285 struct secpolicyindex *); 286 #endif 287 288 /* 289 * Return a held reference to the default SP. 290 */ 291 static struct secpolicy * 292 key_allocsp_default(void) 293 { 294 295 key_addref(V_def_policy); 296 return (V_def_policy); 297 } 298 299 static void 300 ipsec_invalidate_cache(struct inpcb *inp, u_int dir) 301 { 302 struct secpolicy *sp; 303 304 INP_WLOCK_ASSERT(inp); 305 if (dir == IPSEC_DIR_OUTBOUND) { 306 if (inp->inp_sp->flags & INP_INBOUND_POLICY) 307 return; 308 sp = inp->inp_sp->sp_in; 309 inp->inp_sp->sp_in = NULL; 310 } else { 311 if (inp->inp_sp->flags & INP_OUTBOUND_POLICY) 312 return; 313 sp = inp->inp_sp->sp_out; 314 inp->inp_sp->sp_out = NULL; 315 } 316 if (sp != NULL) 317 key_freesp(&sp); /* release extra reference */ 318 } 319 320 static void 321 ipsec_cachepolicy(struct inpcb *inp, struct secpolicy *sp, u_int dir) 322 { 323 uint32_t genid; 324 int downgrade; 325 326 INP_LOCK_ASSERT(inp); 327 328 if (dir == IPSEC_DIR_OUTBOUND) { 329 /* Do we have configured PCB policy? */ 330 if (inp->inp_sp->flags & INP_OUTBOUND_POLICY) 331 return; 332 /* Another thread has already set cached policy */ 333 if (inp->inp_sp->sp_out != NULL) 334 return; 335 /* 336 * Do not cache OUTBOUND policy if PCB isn't connected, 337 * i.e. foreign address is INADDR_ANY/UNSPECIFIED. 338 */ 339 #ifdef INET 340 if ((inp->inp_vflag & INP_IPV4) != 0 && 341 inp->inp_faddr.s_addr == INADDR_ANY) 342 return; 343 #endif 344 #ifdef INET6 345 if ((inp->inp_vflag & INP_IPV6) != 0 && 346 IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) 347 return; 348 #endif 349 } else { 350 /* Do we have configured PCB policy? */ 351 if (inp->inp_sp->flags & INP_INBOUND_POLICY) 352 return; 353 /* Another thread has already set cached policy */ 354 if (inp->inp_sp->sp_in != NULL) 355 return; 356 /* 357 * Do not cache INBOUND policy for listen socket, 358 * that is bound to INADDR_ANY/UNSPECIFIED address. 359 */ 360 #ifdef INET 361 if ((inp->inp_vflag & INP_IPV4) != 0 && 362 inp->inp_faddr.s_addr == INADDR_ANY) 363 return; 364 #endif 365 #ifdef INET6 366 if ((inp->inp_vflag & INP_IPV6) != 0 && 367 IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) 368 return; 369 #endif 370 } 371 downgrade = 0; 372 if (!INP_WLOCKED(inp)) { 373 if ((downgrade = INP_TRY_UPGRADE(inp)) == 0) 374 return; 375 } 376 if (dir == IPSEC_DIR_OUTBOUND) 377 inp->inp_sp->sp_out = sp; 378 else 379 inp->inp_sp->sp_in = sp; 380 /* 381 * SP is already referenced by the lookup code. 382 * We take extra reference here to avoid race in the 383 * ipsec_getpcbpolicy() function - SP will not be freed in the 384 * time between we take SP pointer from the cache and key_addref() 385 * call. 386 */ 387 key_addref(sp); 388 genid = key_getspgen(); 389 if (genid != inp->inp_sp->genid) { 390 ipsec_invalidate_cache(inp, dir); 391 inp->inp_sp->genid = genid; 392 } 393 KEYDBG(IPSEC_STAMP, 394 printf("%s: PCB(%p): cached %s SP(%p)\n", 395 __func__, inp, dir == IPSEC_DIR_OUTBOUND ? "OUTBOUND": 396 "INBOUND", sp)); 397 if (downgrade != 0) 398 INP_DOWNGRADE(inp); 399 } 400 401 static struct secpolicy * 402 ipsec_checkpolicy(struct secpolicy *sp, struct inpcb *inp, int *error) 403 { 404 405 /* Save found OUTBOUND policy into PCB SP cache. */ 406 if (inp != NULL && inp->inp_sp != NULL && inp->inp_sp->sp_out == NULL) 407 ipsec_cachepolicy(inp, sp, IPSEC_DIR_OUTBOUND); 408 409 switch (sp->policy) { 410 default: 411 printf("%s: invalid policy %u\n", __func__, sp->policy); 412 /* FALLTHROUGH */ 413 case IPSEC_POLICY_DISCARD: 414 *error = -EINVAL; /* Packet is discarded by caller. */ 415 /* FALLTHROUGH */ 416 case IPSEC_POLICY_BYPASS: 417 case IPSEC_POLICY_NONE: 418 key_freesp(&sp); 419 sp = NULL; /* NB: force NULL result. */ 420 break; 421 case IPSEC_POLICY_IPSEC: 422 /* XXXAE: handle LARVAL SP */ 423 break; 424 } 425 KEYDBG(IPSEC_DUMP, 426 printf("%s: get SP(%p), error %d\n", __func__, sp, *error)); 427 return (sp); 428 } 429 430 static struct secpolicy * 431 ipsec_getpcbpolicy(struct inpcb *inp, u_int dir) 432 { 433 struct secpolicy *sp; 434 int flags, downgrade; 435 436 if (inp == NULL || inp->inp_sp == NULL) 437 return (NULL); 438 439 INP_LOCK_ASSERT(inp); 440 441 flags = inp->inp_sp->flags; 442 if (dir == IPSEC_DIR_OUTBOUND) { 443 sp = inp->inp_sp->sp_out; 444 flags &= INP_OUTBOUND_POLICY; 445 } else { 446 sp = inp->inp_sp->sp_in; 447 flags &= INP_INBOUND_POLICY; 448 } 449 /* 450 * Check flags. If we have PCB SP, just return it. 451 * Otherwise we need to check that cached SP entry isn't stale. 452 */ 453 if (flags == 0) { 454 if (sp == NULL) 455 return (NULL); 456 if (inp->inp_sp->genid != key_getspgen()) { 457 /* Invalidate the cache. */ 458 downgrade = 0; 459 if (!INP_WLOCKED(inp)) { 460 if ((downgrade = INP_TRY_UPGRADE(inp)) == 0) 461 return (NULL); 462 } 463 ipsec_invalidate_cache(inp, IPSEC_DIR_OUTBOUND); 464 ipsec_invalidate_cache(inp, IPSEC_DIR_INBOUND); 465 if (downgrade != 0) 466 INP_DOWNGRADE(inp); 467 return (NULL); 468 } 469 KEYDBG(IPSEC_STAMP, 470 printf("%s: PCB(%p): cache hit SP(%p)\n", 471 __func__, inp, sp)); 472 /* Return referenced cached policy */ 473 } 474 key_addref(sp); 475 return (sp); 476 } 477 478 #ifdef INET 479 static void 480 ipsec4_get_ulp(const struct mbuf *m, struct secpolicyindex *spidx, 481 int needport) 482 { 483 uint8_t nxt; 484 int off; 485 486 /* Sanity check. */ 487 IPSEC_ASSERT(m->m_pkthdr.len >= sizeof(struct ip), 488 ("packet too short")); 489 490 if (m->m_len >= sizeof (struct ip)) { 491 const struct ip *ip = mtod(m, const struct ip *); 492 if (ip->ip_off & htons(IP_MF | IP_OFFMASK)) 493 goto done; 494 off = ip->ip_hl << 2; 495 nxt = ip->ip_p; 496 } else { 497 struct ip ih; 498 499 m_copydata(m, 0, sizeof (struct ip), (caddr_t) &ih); 500 if (ih.ip_off & htons(IP_MF | IP_OFFMASK)) 501 goto done; 502 off = ih.ip_hl << 2; 503 nxt = ih.ip_p; 504 } 505 506 while (off < m->m_pkthdr.len) { 507 struct ip6_ext ip6e; 508 struct tcphdr th; 509 struct udphdr uh; 510 511 switch (nxt) { 512 case IPPROTO_TCP: 513 spidx->ul_proto = nxt; 514 if (!needport) 515 goto done_proto; 516 if (off + sizeof(struct tcphdr) > m->m_pkthdr.len) 517 goto done; 518 m_copydata(m, off, sizeof (th), (caddr_t) &th); 519 spidx->src.sin.sin_port = th.th_sport; 520 spidx->dst.sin.sin_port = th.th_dport; 521 return; 522 case IPPROTO_UDP: 523 spidx->ul_proto = nxt; 524 if (!needport) 525 goto done_proto; 526 if (off + sizeof(struct udphdr) > m->m_pkthdr.len) 527 goto done; 528 m_copydata(m, off, sizeof (uh), (caddr_t) &uh); 529 spidx->src.sin.sin_port = uh.uh_sport; 530 spidx->dst.sin.sin_port = uh.uh_dport; 531 return; 532 case IPPROTO_AH: 533 if (off + sizeof(ip6e) > m->m_pkthdr.len) 534 goto done; 535 /* XXX Sigh, this works but is totally bogus. */ 536 m_copydata(m, off, sizeof(ip6e), (caddr_t) &ip6e); 537 off += (ip6e.ip6e_len + 2) << 2; 538 nxt = ip6e.ip6e_nxt; 539 break; 540 case IPPROTO_ICMP: 541 default: 542 /* XXX Intermediate headers??? */ 543 spidx->ul_proto = nxt; 544 goto done_proto; 545 } 546 } 547 done: 548 spidx->ul_proto = IPSEC_ULPROTO_ANY; 549 done_proto: 550 spidx->src.sin.sin_port = IPSEC_PORT_ANY; 551 spidx->dst.sin.sin_port = IPSEC_PORT_ANY; 552 KEYDBG(IPSEC_DUMP, 553 printf("%s: ", __func__); kdebug_secpolicyindex(spidx, NULL)); 554 } 555 556 static void 557 ipsec4_setspidx_ipaddr(const struct mbuf *m, struct secpolicyindex *spidx) 558 { 559 560 ipsec4_setsockaddrs(m, &spidx->src, &spidx->dst); 561 spidx->prefs = sizeof(struct in_addr) << 3; 562 spidx->prefd = sizeof(struct in_addr) << 3; 563 } 564 565 static struct secpolicy * 566 ipsec4_getpolicy(const struct mbuf *m, struct inpcb *inp, u_int dir) 567 { 568 struct secpolicyindex spidx; 569 struct secpolicy *sp; 570 571 sp = ipsec_getpcbpolicy(inp, dir); 572 if (sp == NULL && key_havesp(dir)) { 573 /* Make an index to look for a policy. */ 574 ipsec4_setspidx_ipaddr(m, &spidx); 575 /* Fill ports in spidx if we have inpcb. */ 576 ipsec4_get_ulp(m, &spidx, inp != NULL); 577 spidx.dir = dir; 578 sp = key_allocsp(&spidx, dir); 579 } 580 if (sp == NULL) /* No SP found, use system default. */ 581 sp = key_allocsp_default(); 582 return (sp); 583 } 584 585 /* 586 * Check security policy for *OUTBOUND* IPv4 packet. 587 */ 588 struct secpolicy * 589 ipsec4_checkpolicy(const struct mbuf *m, struct inpcb *inp, int *error) 590 { 591 struct secpolicy *sp; 592 593 *error = 0; 594 sp = ipsec4_getpolicy(m, inp, IPSEC_DIR_OUTBOUND); 595 if (sp != NULL) 596 sp = ipsec_checkpolicy(sp, inp, error); 597 if (sp == NULL) { 598 switch (*error) { 599 case 0: /* No IPsec required: BYPASS or NONE */ 600 break; 601 case -EINVAL: 602 IPSECSTAT_INC(ips_out_polvio); 603 break; 604 default: 605 IPSECSTAT_INC(ips_out_inval); 606 } 607 } 608 KEYDBG(IPSEC_STAMP, 609 printf("%s: using SP(%p), error %d\n", __func__, sp, *error)); 610 if (sp != NULL) 611 KEYDBG(IPSEC_DATA, kdebug_secpolicy(sp)); 612 return (sp); 613 } 614 615 /* 616 * Check IPv4 packet against *INBOUND* security policy. 617 * This function is called from tcp_input(), udp_input(), 618 * rip_input() and sctp_input(). 619 */ 620 int 621 ipsec4_in_reject(const struct mbuf *m, struct inpcb *inp) 622 { 623 struct secpolicy *sp; 624 int result; 625 626 sp = ipsec4_getpolicy(m, inp, IPSEC_DIR_INBOUND); 627 result = ipsec_in_reject(sp, inp, m); 628 key_freesp(&sp); 629 if (result != 0) 630 IPSECSTAT_INC(ips_in_polvio); 631 return (result); 632 } 633 634 /* 635 * IPSEC_CAP() method implementation for IPv4. 636 */ 637 int 638 ipsec4_capability(struct mbuf *m, u_int cap) 639 { 640 641 switch (cap) { 642 case IPSEC_CAP_BYPASS_FILTER: 643 /* 644 * Bypass packet filtering for packets previously handled 645 * by IPsec. 646 */ 647 if (!V_ip4_filtertunnel && 648 m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL) 649 return (1); 650 return (0); 651 case IPSEC_CAP_OPERABLE: 652 /* Do we have active security policies? */ 653 if (key_havesp(IPSEC_DIR_INBOUND) != 0 || 654 key_havesp(IPSEC_DIR_OUTBOUND) != 0) 655 return (1); 656 return (0); 657 }; 658 return (EOPNOTSUPP); 659 } 660 661 #endif /* INET */ 662 663 #ifdef INET6 664 static void 665 ipsec6_get_ulp(const struct mbuf *m, struct secpolicyindex *spidx, 666 int needport) 667 { 668 struct tcphdr th; 669 struct udphdr uh; 670 struct icmp6_hdr ih; 671 int off, nxt; 672 673 IPSEC_ASSERT(m->m_pkthdr.len >= sizeof(struct ip6_hdr), 674 ("packet too short")); 675 676 /* Set default. */ 677 spidx->ul_proto = IPSEC_ULPROTO_ANY; 678 spidx->src.sin6.sin6_port = IPSEC_PORT_ANY; 679 spidx->dst.sin6.sin6_port = IPSEC_PORT_ANY; 680 681 nxt = -1; 682 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt); 683 if (off < 0 || m->m_pkthdr.len < off) 684 return; 685 686 switch (nxt) { 687 case IPPROTO_TCP: 688 spidx->ul_proto = nxt; 689 if (!needport) 690 break; 691 if (off + sizeof(struct tcphdr) > m->m_pkthdr.len) 692 break; 693 m_copydata(m, off, sizeof(th), (caddr_t)&th); 694 spidx->src.sin6.sin6_port = th.th_sport; 695 spidx->dst.sin6.sin6_port = th.th_dport; 696 break; 697 case IPPROTO_UDP: 698 spidx->ul_proto = nxt; 699 if (!needport) 700 break; 701 if (off + sizeof(struct udphdr) > m->m_pkthdr.len) 702 break; 703 m_copydata(m, off, sizeof(uh), (caddr_t)&uh); 704 spidx->src.sin6.sin6_port = uh.uh_sport; 705 spidx->dst.sin6.sin6_port = uh.uh_dport; 706 break; 707 case IPPROTO_ICMPV6: 708 spidx->ul_proto = nxt; 709 if (off + sizeof(struct icmp6_hdr) > m->m_pkthdr.len) 710 break; 711 m_copydata(m, off, sizeof(ih), (caddr_t)&ih); 712 spidx->src.sin6.sin6_port = htons((uint16_t)ih.icmp6_type); 713 spidx->dst.sin6.sin6_port = htons((uint16_t)ih.icmp6_code); 714 break; 715 default: 716 /* XXX Intermediate headers??? */ 717 spidx->ul_proto = nxt; 718 break; 719 } 720 KEYDBG(IPSEC_DUMP, 721 printf("%s: ", __func__); kdebug_secpolicyindex(spidx, NULL)); 722 } 723 724 static void 725 ipsec6_setspidx_ipaddr(const struct mbuf *m, struct secpolicyindex *spidx) 726 { 727 728 ipsec6_setsockaddrs(m, &spidx->src, &spidx->dst); 729 spidx->prefs = sizeof(struct in6_addr) << 3; 730 spidx->prefd = sizeof(struct in6_addr) << 3; 731 } 732 733 static struct secpolicy * 734 ipsec6_getpolicy(const struct mbuf *m, struct inpcb *inp, u_int dir) 735 { 736 struct secpolicyindex spidx; 737 struct secpolicy *sp; 738 739 sp = ipsec_getpcbpolicy(inp, dir); 740 if (sp == NULL && key_havesp(dir)) { 741 /* Make an index to look for a policy. */ 742 ipsec6_setspidx_ipaddr(m, &spidx); 743 /* Fill ports in spidx if we have inpcb. */ 744 ipsec6_get_ulp(m, &spidx, inp != NULL); 745 spidx.dir = dir; 746 sp = key_allocsp(&spidx, dir); 747 } 748 if (sp == NULL) /* No SP found, use system default. */ 749 sp = key_allocsp_default(); 750 return (sp); 751 } 752 753 /* 754 * Check security policy for *OUTBOUND* IPv6 packet. 755 */ 756 struct secpolicy * 757 ipsec6_checkpolicy(const struct mbuf *m, struct inpcb *inp, int *error) 758 { 759 struct secpolicy *sp; 760 761 *error = 0; 762 sp = ipsec6_getpolicy(m, inp, IPSEC_DIR_OUTBOUND); 763 if (sp != NULL) 764 sp = ipsec_checkpolicy(sp, inp, error); 765 if (sp == NULL) { 766 switch (*error) { 767 case 0: /* No IPsec required: BYPASS or NONE */ 768 break; 769 case -EINVAL: 770 IPSEC6STAT_INC(ips_out_polvio); 771 break; 772 default: 773 IPSEC6STAT_INC(ips_out_inval); 774 } 775 } 776 KEYDBG(IPSEC_STAMP, 777 printf("%s: using SP(%p), error %d\n", __func__, sp, *error)); 778 if (sp != NULL) 779 KEYDBG(IPSEC_DATA, kdebug_secpolicy(sp)); 780 return (sp); 781 } 782 783 /* 784 * Check IPv6 packet against inbound security policy. 785 * This function is called from tcp6_input(), udp6_input(), 786 * rip6_input() and sctp_input(). 787 */ 788 int 789 ipsec6_in_reject(const struct mbuf *m, struct inpcb *inp) 790 { 791 struct secpolicy *sp; 792 int result; 793 794 sp = ipsec6_getpolicy(m, inp, IPSEC_DIR_INBOUND); 795 result = ipsec_in_reject(sp, inp, m); 796 key_freesp(&sp); 797 if (result) 798 IPSEC6STAT_INC(ips_in_polvio); 799 return (result); 800 } 801 802 /* 803 * IPSEC_CAP() method implementation for IPv6. 804 */ 805 int 806 ipsec6_capability(struct mbuf *m, u_int cap) 807 { 808 809 switch (cap) { 810 case IPSEC_CAP_BYPASS_FILTER: 811 /* 812 * Bypass packet filtering for packets previously handled 813 * by IPsec. 814 */ 815 if (!V_ip6_filtertunnel && 816 m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL) 817 return (1); 818 return (0); 819 case IPSEC_CAP_OPERABLE: 820 /* Do we have active security policies? */ 821 if (key_havesp(IPSEC_DIR_INBOUND) != 0 || 822 key_havesp(IPSEC_DIR_OUTBOUND) != 0) 823 return (1); 824 return (0); 825 }; 826 return (EOPNOTSUPP); 827 } 828 #endif /* INET6 */ 829 830 int 831 ipsec_run_hhooks(struct ipsec_ctx_data *ctx, int type) 832 { 833 int idx; 834 835 switch (ctx->af) { 836 #ifdef INET 837 case AF_INET: 838 idx = HHOOK_IPSEC_INET; 839 break; 840 #endif 841 #ifdef INET6 842 case AF_INET6: 843 idx = HHOOK_IPSEC_INET6; 844 break; 845 #endif 846 default: 847 return (EPFNOSUPPORT); 848 } 849 if (type == HHOOK_TYPE_IPSEC_IN) 850 HHOOKS_RUN_IF(V_ipsec_hhh_in[idx], ctx, NULL); 851 else 852 HHOOKS_RUN_IF(V_ipsec_hhh_out[idx], ctx, NULL); 853 if (*ctx->mp == NULL) 854 return (EACCES); 855 return (0); 856 } 857 858 /* 859 * Return current level. 860 * Either IPSEC_LEVEL_USE or IPSEC_LEVEL_REQUIRE are always returned. 861 */ 862 u_int 863 ipsec_get_reqlevel(struct secpolicy *sp, u_int idx) 864 { 865 struct ipsecrequest *isr; 866 u_int esp_trans_deflev, esp_net_deflev; 867 u_int ah_trans_deflev, ah_net_deflev; 868 u_int level = 0; 869 870 IPSEC_ASSERT(idx < sp->tcount, ("Wrong IPsec request index %d", idx)); 871 /* XXX Note that we have ipseclog() expanded here - code sync issue. */ 872 #define IPSEC_CHECK_DEFAULT(lev) \ 873 (((lev) != IPSEC_LEVEL_USE && (lev) != IPSEC_LEVEL_REQUIRE && \ 874 (lev) != IPSEC_LEVEL_UNIQUE) \ 875 ? (V_ipsec_debug ? \ 876 log(LOG_INFO, "fixed system default level " #lev ":%d->%d\n",\ 877 (lev), IPSEC_LEVEL_REQUIRE) : 0), \ 878 (lev) = IPSEC_LEVEL_REQUIRE, (lev) : (lev)) 879 880 /* 881 * IPsec VTI uses unique security policy with fake spidx filled 882 * with zeroes. Just return IPSEC_LEVEL_REQUIRE instead of doing 883 * full level lookup for such policies. 884 */ 885 if (sp->state == IPSEC_SPSTATE_IFNET) { 886 IPSEC_ASSERT(sp->req[idx]->level == IPSEC_LEVEL_UNIQUE, 887 ("Wrong IPsec request level %d", sp->req[idx]->level)); 888 return (IPSEC_LEVEL_REQUIRE); 889 } 890 891 /* Set default level. */ 892 switch (sp->spidx.src.sa.sa_family) { 893 #ifdef INET 894 case AF_INET: 895 esp_trans_deflev = IPSEC_CHECK_DEFAULT(V_ip4_esp_trans_deflev); 896 esp_net_deflev = IPSEC_CHECK_DEFAULT(V_ip4_esp_net_deflev); 897 ah_trans_deflev = IPSEC_CHECK_DEFAULT(V_ip4_ah_trans_deflev); 898 ah_net_deflev = IPSEC_CHECK_DEFAULT(V_ip4_ah_net_deflev); 899 break; 900 #endif 901 #ifdef INET6 902 case AF_INET6: 903 esp_trans_deflev = IPSEC_CHECK_DEFAULT(V_ip6_esp_trans_deflev); 904 esp_net_deflev = IPSEC_CHECK_DEFAULT(V_ip6_esp_net_deflev); 905 ah_trans_deflev = IPSEC_CHECK_DEFAULT(V_ip6_ah_trans_deflev); 906 ah_net_deflev = IPSEC_CHECK_DEFAULT(V_ip6_ah_net_deflev); 907 break; 908 #endif /* INET6 */ 909 default: 910 panic("%s: unknown af %u", 911 __func__, sp->spidx.src.sa.sa_family); 912 } 913 914 #undef IPSEC_CHECK_DEFAULT 915 916 isr = sp->req[idx]; 917 /* Set level. */ 918 switch (isr->level) { 919 case IPSEC_LEVEL_DEFAULT: 920 switch (isr->saidx.proto) { 921 case IPPROTO_ESP: 922 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) 923 level = esp_net_deflev; 924 else 925 level = esp_trans_deflev; 926 break; 927 case IPPROTO_AH: 928 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) 929 level = ah_net_deflev; 930 else 931 level = ah_trans_deflev; 932 break; 933 case IPPROTO_IPCOMP: 934 /* 935 * We don't really care, as IPcomp document says that 936 * we shouldn't compress small packets. 937 */ 938 level = IPSEC_LEVEL_USE; 939 break; 940 default: 941 panic("%s: Illegal protocol defined %u\n", __func__, 942 isr->saidx.proto); 943 } 944 break; 945 946 case IPSEC_LEVEL_USE: 947 case IPSEC_LEVEL_REQUIRE: 948 level = isr->level; 949 break; 950 case IPSEC_LEVEL_UNIQUE: 951 level = IPSEC_LEVEL_REQUIRE; 952 break; 953 954 default: 955 panic("%s: Illegal IPsec level %u\n", __func__, isr->level); 956 } 957 958 return (level); 959 } 960 961 static int 962 ipsec_check_history(const struct mbuf *m, struct secpolicy *sp, u_int idx) 963 { 964 struct xform_history *xh; 965 struct m_tag *mtag; 966 967 mtag = NULL; 968 while ((mtag = m_tag_find(__DECONST(struct mbuf *, m), 969 PACKET_TAG_IPSEC_IN_DONE, mtag)) != NULL) { 970 xh = (struct xform_history *)(mtag + 1); 971 KEYDBG(IPSEC_DATA, 972 char buf[IPSEC_ADDRSTRLEN]; 973 printf("%s: mode %s proto %u dst %s\n", __func__, 974 kdebug_secasindex_mode(xh->mode), xh->proto, 975 ipsec_address(&xh->dst, buf, sizeof(buf)))); 976 if (xh->proto != sp->req[idx]->saidx.proto) 977 continue; 978 /* If SA had IPSEC_MODE_ANY, consider this as match. */ 979 if (xh->mode != sp->req[idx]->saidx.mode && 980 xh->mode != IPSEC_MODE_ANY) 981 continue; 982 /* 983 * For transport mode IPsec request doesn't contain 984 * addresses. We need to use address from spidx. 985 */ 986 if (sp->req[idx]->saidx.mode == IPSEC_MODE_TRANSPORT) { 987 if (key_sockaddrcmp_withmask(&xh->dst.sa, 988 &sp->spidx.dst.sa, sp->spidx.prefd) != 0) 989 continue; 990 } else { 991 if (key_sockaddrcmp(&xh->dst.sa, 992 &sp->req[idx]->saidx.dst.sa, 0) != 0) 993 continue; 994 } 995 return (0); /* matched */ 996 } 997 return (1); 998 } 999 1000 /* 1001 * Check security policy requirements against the actual 1002 * packet contents. Return one if the packet should be 1003 * reject as "invalid"; otherwiser return zero to have the 1004 * packet treated as "valid". 1005 * 1006 * OUT: 1007 * 0: valid 1008 * 1: invalid 1009 */ 1010 static int 1011 ipsec_in_reject(struct secpolicy *sp, struct inpcb *inp, const struct mbuf *m) 1012 { 1013 int i; 1014 1015 KEYDBG(IPSEC_STAMP, 1016 printf("%s: PCB(%p): using SP(%p)\n", __func__, inp, sp)); 1017 KEYDBG(IPSEC_DATA, kdebug_secpolicy(sp)); 1018 1019 if (inp != NULL && inp->inp_sp != NULL && inp->inp_sp->sp_in == NULL) 1020 ipsec_cachepolicy(inp, sp, IPSEC_DIR_INBOUND); 1021 1022 /* Check policy. */ 1023 switch (sp->policy) { 1024 case IPSEC_POLICY_DISCARD: 1025 return (1); 1026 case IPSEC_POLICY_BYPASS: 1027 case IPSEC_POLICY_NONE: 1028 return (0); 1029 } 1030 1031 IPSEC_ASSERT(sp->policy == IPSEC_POLICY_IPSEC, 1032 ("invalid policy %u", sp->policy)); 1033 1034 /* 1035 * ipsec[46]_common_input_cb after each transform adds 1036 * PACKET_TAG_IPSEC_IN_DONE mbuf tag. It contains SPI, proto, mode 1037 * and destination address from saidx. We can compare info from 1038 * these tags with requirements in SP. 1039 */ 1040 for (i = 0; i < sp->tcount; i++) { 1041 /* 1042 * Do not check IPcomp, since IPcomp document 1043 * says that we shouldn't compress small packets. 1044 * IPComp policy should always be treated as being 1045 * in "use" level. 1046 */ 1047 if (sp->req[i]->saidx.proto == IPPROTO_IPCOMP || 1048 ipsec_get_reqlevel(sp, i) != IPSEC_LEVEL_REQUIRE) 1049 continue; 1050 if (V_check_policy_history != 0 && 1051 ipsec_check_history(m, sp, i) != 0) 1052 return (1); 1053 else switch (sp->req[i]->saidx.proto) { 1054 case IPPROTO_ESP: 1055 if ((m->m_flags & M_DECRYPTED) == 0) { 1056 KEYDBG(IPSEC_DUMP, 1057 printf("%s: ESP m_flags:%x\n", __func__, 1058 m->m_flags)); 1059 return (1); 1060 } 1061 break; 1062 case IPPROTO_AH: 1063 if ((m->m_flags & M_AUTHIPHDR) == 0) { 1064 KEYDBG(IPSEC_DUMP, 1065 printf("%s: AH m_flags:%x\n", __func__, 1066 m->m_flags)); 1067 return (1); 1068 } 1069 break; 1070 } 1071 } 1072 return (0); /* Valid. */ 1073 } 1074 1075 /* 1076 * Compute the byte size to be occupied by IPsec header. 1077 * In case it is tunnelled, it includes the size of outer IP header. 1078 */ 1079 static size_t 1080 ipsec_hdrsiz_internal(struct secpolicy *sp) 1081 { 1082 size_t size; 1083 int i; 1084 1085 KEYDBG(IPSEC_STAMP, printf("%s: using SP(%p)\n", __func__, sp)); 1086 KEYDBG(IPSEC_DATA, kdebug_secpolicy(sp)); 1087 1088 switch (sp->policy) { 1089 case IPSEC_POLICY_DISCARD: 1090 case IPSEC_POLICY_BYPASS: 1091 case IPSEC_POLICY_NONE: 1092 return (0); 1093 } 1094 1095 IPSEC_ASSERT(sp->policy == IPSEC_POLICY_IPSEC, 1096 ("invalid policy %u", sp->policy)); 1097 1098 /* 1099 * XXX: for each transform we need to lookup suitable SA 1100 * and use info from SA to calculate headers size. 1101 * XXX: for NAT-T we need to cosider UDP header size. 1102 */ 1103 size = 0; 1104 for (i = 0; i < sp->tcount; i++) { 1105 switch (sp->req[i]->saidx.proto) { 1106 case IPPROTO_ESP: 1107 size += esp_hdrsiz(NULL); 1108 break; 1109 case IPPROTO_AH: 1110 size += ah_hdrsiz(NULL); 1111 break; 1112 case IPPROTO_IPCOMP: 1113 size += sizeof(struct ipcomp); 1114 break; 1115 } 1116 1117 if (sp->req[i]->saidx.mode == IPSEC_MODE_TUNNEL) { 1118 switch (sp->req[i]->saidx.dst.sa.sa_family) { 1119 #ifdef INET 1120 case AF_INET: 1121 size += sizeof(struct ip); 1122 break; 1123 #endif 1124 #ifdef INET6 1125 case AF_INET6: 1126 size += sizeof(struct ip6_hdr); 1127 break; 1128 #endif 1129 default: 1130 ipseclog((LOG_ERR, "%s: unknown AF %d in " 1131 "IPsec tunnel SA\n", __func__, 1132 sp->req[i]->saidx.dst.sa.sa_family)); 1133 break; 1134 } 1135 } 1136 } 1137 return (size); 1138 } 1139 1140 /* 1141 * Compute ESP/AH header size for protocols with PCB, including 1142 * outer IP header. Currently only tcp_output() uses it. 1143 */ 1144 size_t 1145 ipsec_hdrsiz_inpcb(struct inpcb *inp) 1146 { 1147 struct secpolicyindex spidx; 1148 struct secpolicy *sp; 1149 size_t sz; 1150 1151 sp = ipsec_getpcbpolicy(inp, IPSEC_DIR_OUTBOUND); 1152 if (sp == NULL && key_havesp(IPSEC_DIR_OUTBOUND)) { 1153 ipsec_setspidx_inpcb(inp, &spidx, IPSEC_DIR_OUTBOUND); 1154 sp = key_allocsp(&spidx, IPSEC_DIR_OUTBOUND); 1155 } 1156 if (sp == NULL) 1157 sp = key_allocsp_default(); 1158 sz = ipsec_hdrsiz_internal(sp); 1159 key_freesp(&sp); 1160 return (sz); 1161 } 1162 1163 /* 1164 * Check the variable replay window. 1165 * ipsec_chkreplay() performs replay check before ICV verification. 1166 * ipsec_updatereplay() updates replay bitmap. This must be called after 1167 * ICV verification (it also performs replay check, which is usually done 1168 * beforehand). 1169 * 0 (zero) is returned if packet disallowed, 1 if packet permitted. 1170 * 1171 * Based on RFC 6479. Blocks are 32 bits unsigned integers 1172 */ 1173 1174 #define IPSEC_BITMAP_INDEX_MASK(w) (w - 1) 1175 #define IPSEC_REDUNDANT_BIT_SHIFTS 5 1176 #define IPSEC_REDUNDANT_BITS (1 << IPSEC_REDUNDANT_BIT_SHIFTS) 1177 #define IPSEC_BITMAP_LOC_MASK (IPSEC_REDUNDANT_BITS - 1) 1178 1179 int 1180 ipsec_chkreplay(uint32_t seq, struct secasvar *sav) 1181 { 1182 const struct secreplay *replay; 1183 uint32_t wsizeb; /* Constant: window size. */ 1184 int index, bit_location; 1185 1186 IPSEC_ASSERT(sav != NULL, ("Null SA")); 1187 IPSEC_ASSERT(sav->replay != NULL, ("Null replay state")); 1188 1189 replay = sav->replay; 1190 1191 /* No need to check replay if disabled. */ 1192 if (replay->wsize == 0) 1193 return (1); 1194 1195 /* Constant. */ 1196 wsizeb = replay->wsize << 3; 1197 1198 /* Sequence number of 0 is invalid. */ 1199 if (seq == 0) 1200 return (0); 1201 1202 /* First time is always okay. */ 1203 if (replay->count == 0) 1204 return (1); 1205 1206 /* Larger sequences are okay. */ 1207 if (seq > replay->lastseq) 1208 return (1); 1209 1210 /* Over range to check, i.e. too old or wrapped. */ 1211 if (replay->lastseq - seq >= wsizeb) 1212 return (0); 1213 1214 /* The sequence is inside the sliding window 1215 * now check the bit in the bitmap 1216 * bit location only depends on the sequence number 1217 */ 1218 bit_location = seq & IPSEC_BITMAP_LOC_MASK; 1219 index = (seq >> IPSEC_REDUNDANT_BIT_SHIFTS) 1220 & IPSEC_BITMAP_INDEX_MASK(replay->bitmap_size); 1221 1222 /* This packet already seen? */ 1223 if ((replay->bitmap)[index] & (1 << bit_location)) 1224 return (0); 1225 return (1); 1226 } 1227 1228 /* 1229 * Check replay counter whether to update or not. 1230 * OUT: 0: OK 1231 * 1: NG 1232 */ 1233 int 1234 ipsec_updatereplay(uint32_t seq, struct secasvar *sav) 1235 { 1236 char buf[128]; 1237 struct secreplay *replay; 1238 uint32_t wsizeb; /* Constant: window size. */ 1239 int diff, index, bit_location; 1240 1241 IPSEC_ASSERT(sav != NULL, ("Null SA")); 1242 IPSEC_ASSERT(sav->replay != NULL, ("Null replay state")); 1243 1244 replay = sav->replay; 1245 1246 if (replay->wsize == 0) 1247 goto ok; /* No need to check replay. */ 1248 1249 /* Constant. */ 1250 wsizeb = replay->wsize << 3; 1251 1252 /* Sequence number of 0 is invalid. */ 1253 if (seq == 0) 1254 return (1); 1255 1256 /* The packet is too old, no need to update */ 1257 if (wsizeb + seq < replay->lastseq) 1258 goto ok; 1259 1260 /* Now update the bit */ 1261 index = (seq >> IPSEC_REDUNDANT_BIT_SHIFTS); 1262 1263 /* First check if the sequence number is in the range */ 1264 if (seq > replay->lastseq) { 1265 int id; 1266 int index_cur = replay->lastseq >> IPSEC_REDUNDANT_BIT_SHIFTS; 1267 1268 diff = index - index_cur; 1269 if (diff > replay->bitmap_size) { 1270 /* something unusual in this case */ 1271 diff = replay->bitmap_size; 1272 } 1273 1274 for (id = 0; id < diff; ++id) { 1275 replay->bitmap[(id + index_cur + 1) 1276 & IPSEC_BITMAP_INDEX_MASK(replay->bitmap_size)] = 0; 1277 } 1278 1279 replay->lastseq = seq; 1280 } 1281 1282 index &= IPSEC_BITMAP_INDEX_MASK(replay->bitmap_size); 1283 bit_location = seq & IPSEC_BITMAP_LOC_MASK; 1284 1285 /* this packet has already been received */ 1286 if (replay->bitmap[index] & (1 << bit_location)) 1287 return (1); 1288 1289 replay->bitmap[index] |= (1 << bit_location); 1290 1291 ok: 1292 if (replay->count == ~0) { 1293 1294 /* Set overflow flag. */ 1295 replay->overflow++; 1296 1297 /* Don't increment, no more packets accepted. */ 1298 if ((sav->flags & SADB_X_EXT_CYCSEQ) == 0) { 1299 if (sav->sah->saidx.proto == IPPROTO_AH) 1300 AHSTAT_INC(ahs_wrap); 1301 else if (sav->sah->saidx.proto == IPPROTO_ESP) 1302 ESPSTAT_INC(esps_wrap); 1303 return (1); 1304 } 1305 1306 ipseclog((LOG_WARNING, "%s: replay counter made %d cycle. %s\n", 1307 __func__, replay->overflow, 1308 ipsec_sa2str(sav, buf, sizeof(buf)))); 1309 } 1310 return (0); 1311 } 1312 1313 int 1314 ipsec_updateid(struct secasvar *sav, uint64_t *new, uint64_t *old) 1315 { 1316 uint64_t tmp; 1317 1318 /* 1319 * tdb_cryptoid is initialized by xform_init(). 1320 * Then it can be changed only when some crypto error occurred or 1321 * when SA is deleted. We stored used cryptoid in the xform_data 1322 * structure. In case when crypto error occurred and crypto 1323 * subsystem has reinited the session, it returns new cryptoid 1324 * and EAGAIN error code. 1325 * 1326 * This function will be called when we got EAGAIN from crypto 1327 * subsystem. 1328 * *new is cryptoid that was returned by crypto subsystem in 1329 * the crp_sid. 1330 * *old is the original cryptoid that we stored in xform_data. 1331 * 1332 * For first failed request *old == sav->tdb_cryptoid, then 1333 * we update sav->tdb_cryptoid and redo crypto_dispatch(). 1334 * For next failed request *old != sav->tdb_cryptoid, then 1335 * we store cryptoid from first request into the *new variable 1336 * and crp_sid from this second session will be returned via 1337 * *old pointer, so caller can release second session. 1338 * 1339 * XXXAE: check this more carefully. 1340 */ 1341 KEYDBG(IPSEC_STAMP, 1342 printf("%s: SA(%p) moves cryptoid %jd -> %jd\n", 1343 __func__, sav, (uintmax_t)(*old), (uintmax_t)(*new))); 1344 KEYDBG(IPSEC_DATA, kdebug_secasv(sav)); 1345 SECASVAR_LOCK(sav); 1346 if (sav->tdb_cryptoid != *old) { 1347 /* cryptoid was already updated */ 1348 tmp = *new; 1349 *new = sav->tdb_cryptoid; 1350 *old = tmp; 1351 SECASVAR_UNLOCK(sav); 1352 return (1); 1353 } 1354 sav->tdb_cryptoid = *new; 1355 SECASVAR_UNLOCK(sav); 1356 return (0); 1357 } 1358 1359 int 1360 ipsec_initialized(void) 1361 { 1362 1363 return (V_def_policy != NULL); 1364 } 1365 1366 static void 1367 def_policy_init(const void *unused __unused) 1368 { 1369 1370 V_def_policy = key_newsp(); 1371 if (V_def_policy != NULL) { 1372 V_def_policy->policy = IPSEC_POLICY_NONE; 1373 /* Force INPCB SP cache invalidation */ 1374 key_bumpspgen(); 1375 } else 1376 printf("%s: failed to initialize default policy\n", __func__); 1377 } 1378 1379 1380 static void 1381 def_policy_uninit(const void *unused __unused) 1382 { 1383 1384 if (V_def_policy != NULL) { 1385 key_freesp(&V_def_policy); 1386 key_bumpspgen(); 1387 } 1388 } 1389 1390 VNET_SYSINIT(def_policy_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_FIRST, 1391 def_policy_init, NULL); 1392 VNET_SYSUNINIT(def_policy_uninit, SI_SUB_PROTO_DOMAIN, SI_ORDER_FIRST, 1393 def_policy_uninit, NULL); 1394