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