1 /* $NetBSD: nattraversal.c,v 1.16 2025/03/07 15:55:29 christos Exp $ */ 2 3 /* 4 * Copyright (C) 2004 SuSE Linux AG, Nuernberg, Germany. 5 * Contributed by: Michal Ludvig <mludvig (at) suse.cz>, SUSE Labs 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 #include "config.h" 34 35 #include <sys/types.h> 36 #include <sys/param.h> 37 38 #ifdef __linux__ 39 #include <linux/udp.h> 40 #endif 41 #if defined(__NetBSD__) || defined (__FreeBSD__) 42 #include <netinet/udp.h> 43 #endif 44 45 #include <stdlib.h> 46 #include <stdio.h> 47 #include <string.h> 48 #include <errno.h> 49 #include <ctype.h> 50 51 #include "var.h" 52 #include "misc.h" 53 #include "vmbuf.h" 54 #include "plog.h" 55 #include "debug.h" 56 57 #include "localconf.h" 58 #include "remoteconf.h" 59 #include "sockmisc.h" 60 #include "isakmp_var.h" 61 #include "isakmp.h" 62 #include "oakley.h" 63 #include "ipsec_doi.h" 64 #include "vendorid.h" 65 #include "handler.h" 66 #include "crypto_openssl.h" 67 #include "schedule.h" 68 #include "nattraversal.h" 69 #include "grabmyaddr.h" 70 71 struct natt_ka_addrs { 72 struct sockaddr *src; 73 struct sockaddr *dst; 74 unsigned in_use; 75 76 TAILQ_ENTRY(natt_ka_addrs) chain; 77 }; 78 79 static TAILQ_HEAD(_natt_ka_addrs, natt_ka_addrs) ka_tree; 80 static struct sched sc_natt = SCHED_INITIALIZER(); 81 82 /* 83 * check if the given vid is NAT-T. 84 */ 85 int 86 natt_vendorid (int vid) 87 { 88 return ( 89 #ifdef ENABLE_NATT_00 90 vid == VENDORID_NATT_00 || 91 #endif 92 #ifdef ENABLE_NATT_01 93 vid == VENDORID_NATT_01 || 94 #endif 95 #ifdef ENABLE_NATT_02 96 vid == VENDORID_NATT_02 || 97 vid == VENDORID_NATT_02_N || 98 #endif 99 #ifdef ENABLE_NATT_03 100 vid == VENDORID_NATT_03 || 101 #endif 102 #ifdef ENABLE_NATT_04 103 vid == VENDORID_NATT_04 || 104 #endif 105 #ifdef ENABLE_NATT_05 106 vid == VENDORID_NATT_05 || 107 #endif 108 #ifdef ENABLE_NATT_06 109 vid == VENDORID_NATT_06 || 110 #endif 111 #ifdef ENABLE_NATT_07 112 vid == VENDORID_NATT_07 || 113 #endif 114 #ifdef ENABLE_NATT_08 115 vid == VENDORID_NATT_08 || 116 #endif 117 /* Always enable NATT RFC if ENABLE_NATT 118 */ 119 vid == VENDORID_NATT_RFC); 120 } 121 122 vchar_t * 123 natt_hash_addr (struct ph1handle *iph1, struct sockaddr *addr) 124 { 125 vchar_t *natd; 126 vchar_t *buf; 127 char *ptr; 128 void *addr_ptr, *addr_port; 129 size_t buf_size, addr_size; 130 int natt_force = 0; 131 132 if (iph1->rmconf != NULL && iph1->rmconf->nat_traversal == NATT_FORCE) 133 natt_force = 1; 134 135 plog (LLV_INFO, LOCATION, addr, "Hashing %s with algo #%d %s\n", 136 saddr2str(addr), iph1->approval->hashtype, 137 natt_force?"(NAT-T forced)":""); 138 139 if (addr->sa_family == AF_INET) { 140 addr_size = sizeof (struct in_addr); /* IPv4 address */ 141 addr_ptr = &((struct sockaddr_in *)addr)->sin_addr; 142 addr_port = &((struct sockaddr_in *)addr)->sin_port; 143 } 144 else if (addr->sa_family == AF_INET6) { 145 addr_size = sizeof (struct in6_addr); /* IPv6 address */ 146 addr_ptr = &((struct sockaddr_in6 *)addr)->sin6_addr; 147 addr_port = &((struct sockaddr_in6 *)addr)->sin6_port; 148 } 149 else { 150 plog (LLV_ERROR, LOCATION, addr, "Unsupported address family #0x%x\n", addr->sa_family); 151 return NULL; 152 } 153 154 buf_size = 2 * sizeof (cookie_t); /* CKY-I + CKY+R */ 155 buf_size += addr_size + 2; /* Address + Port */ 156 157 if ((buf = vmalloc (buf_size)) == NULL) 158 return NULL; 159 160 ptr = buf->v; 161 162 /* Copy-in CKY-I */ 163 memcpy (ptr, iph1->index.i_ck, sizeof (cookie_t)); 164 ptr += sizeof (cookie_t); 165 166 /* Copy-in CKY-I */ 167 memcpy (ptr, iph1->index.r_ck, sizeof (cookie_t)); 168 ptr += sizeof (cookie_t); 169 170 /* Copy-in Address (or zeroes if NATT_FORCE) */ 171 if (natt_force) 172 memset (ptr, 0, addr_size); 173 else 174 memcpy (ptr, addr_ptr, addr_size); 175 ptr += addr_size; 176 177 /* Copy-in Port number */ 178 memcpy (ptr, addr_port, 2); 179 180 natd = oakley_hash (buf, iph1); 181 vfree(buf); 182 183 return natd; 184 } 185 186 int 187 natt_compare_addr_hash (struct ph1handle *iph1, vchar_t *natd_received, 188 int natd_seq) 189 { 190 vchar_t *natd_computed; 191 uint32_t flag; 192 int verified = 0; 193 194 if (iph1->rmconf != NULL && 195 iph1->rmconf->nat_traversal == NATT_FORCE) 196 return verified; 197 198 if (natd_seq == 0) { 199 natd_computed = natt_hash_addr (iph1, iph1->local); 200 flag = NAT_DETECTED_ME; 201 } 202 else { 203 natd_computed = natt_hash_addr (iph1, iph1->remote); 204 flag = NAT_DETECTED_PEER; 205 } 206 207 if (natd_computed == NULL) { 208 plog(LLV_ERROR, LOCATION, NULL, "natd_computed allocation failed\n"); 209 return verified; /* XXX should abort */ 210 } 211 212 if (natd_received->l == natd_computed->l && 213 memcmp (natd_received->v, natd_computed->v, natd_received->l) == 0) { 214 iph1->natt_flags &= ~flag; 215 verified = 1; 216 } 217 218 vfree (natd_computed); 219 220 return verified; 221 } 222 223 int 224 natt_udp_encap (int encmode) 225 { 226 return (encmode == IPSECDOI_ATTR_ENC_MODE_UDPTUNNEL_RFC || 227 encmode == IPSECDOI_ATTR_ENC_MODE_UDPTRNS_RFC || 228 encmode == IPSECDOI_ATTR_ENC_MODE_UDPTUNNEL_DRAFT || 229 encmode == IPSECDOI_ATTR_ENC_MODE_UDPTRNS_DRAFT); 230 } 231 232 int 233 natt_fill_options(struct ph1natt_options *opts, int version) 234 { 235 if (!opts) 236 return -1; 237 238 opts->version = version; 239 240 switch (version) { 241 case VENDORID_NATT_00: 242 case VENDORID_NATT_01: 243 opts->float_port = 0; /* No port floating for those drafts */ 244 opts->payload_nat_d = ISAKMP_NPTYPE_NATD_DRAFT; 245 opts->payload_nat_oa = ISAKMP_NPTYPE_NATOA_DRAFT; 246 opts->mode_udp_tunnel = IPSECDOI_ATTR_ENC_MODE_UDPTUNNEL_DRAFT; 247 opts->mode_udp_transport = IPSECDOI_ATTR_ENC_MODE_UDPTRNS_DRAFT; 248 opts->encaps_type = UDP_ENCAP_ESPINUDP_NON_IKE; 249 break; 250 case VENDORID_NATT_02: 251 case VENDORID_NATT_02_N: 252 case VENDORID_NATT_03: 253 opts->float_port = lcconf->port_isakmp_natt; 254 opts->payload_nat_d = ISAKMP_NPTYPE_NATD_DRAFT; 255 opts->payload_nat_oa = ISAKMP_NPTYPE_NATOA_DRAFT; 256 opts->mode_udp_tunnel = IPSECDOI_ATTR_ENC_MODE_UDPTUNNEL_DRAFT; 257 opts->mode_udp_transport = IPSECDOI_ATTR_ENC_MODE_UDPTRNS_DRAFT; 258 opts->encaps_type = UDP_ENCAP_ESPINUDP; 259 break; 260 case VENDORID_NATT_04: 261 case VENDORID_NATT_05: 262 case VENDORID_NATT_06: 263 case VENDORID_NATT_07: 264 case VENDORID_NATT_08: 265 opts->float_port = lcconf->port_isakmp_natt; 266 opts->payload_nat_d = ISAKMP_NPTYPE_NATD_BADDRAFT; 267 opts->payload_nat_oa = ISAKMP_NPTYPE_NATOA_BADDRAFT; 268 opts->mode_udp_tunnel = IPSECDOI_ATTR_ENC_MODE_UDPTUNNEL_RFC; 269 opts->mode_udp_transport = IPSECDOI_ATTR_ENC_MODE_UDPTRNS_RFC; 270 opts->encaps_type = UDP_ENCAP_ESPINUDP; 271 break; 272 case VENDORID_NATT_RFC: 273 opts->float_port = lcconf->port_isakmp_natt; 274 opts->payload_nat_d = ISAKMP_NPTYPE_NATD_RFC; 275 opts->payload_nat_oa = ISAKMP_NPTYPE_NATOA_RFC; 276 opts->mode_udp_tunnel = IPSECDOI_ATTR_ENC_MODE_UDPTUNNEL_RFC; 277 opts->mode_udp_transport = IPSECDOI_ATTR_ENC_MODE_UDPTRNS_RFC; 278 opts->encaps_type = UDP_ENCAP_ESPINUDP; 279 break; 280 default: 281 plog(LLV_ERROR, LOCATION, NULL, 282 "unsupported NAT-T version: %s\n", 283 vid_string_by_id(version)); 284 return -1; 285 } 286 287 opts->mode_udp_diff = opts->mode_udp_tunnel - IPSECDOI_ATTR_ENC_MODE_TUNNEL; 288 289 return 0; 290 } 291 292 void 293 natt_float_ports(struct ph1handle *iph1) 294 { 295 if (!(iph1->natt_flags & NAT_DETECTED)) 296 return; 297 if (!iph1->natt_options->float_port) { 298 /* Drafts 00 / 01, just schedule keepalive */ 299 natt_keepalive_add_ph1 (iph1); 300 return; 301 } 302 303 set_port(iph1->local, iph1->natt_options->float_port); 304 set_port(iph1->remote, iph1->natt_options->float_port); 305 iph1->natt_flags |= NAT_PORTS_CHANGED | NAT_ADD_NON_ESP_MARKER; 306 307 natt_keepalive_add_ph1(iph1); 308 } 309 310 /*ARGSUSED*/ 311 static int 312 natt_is_enabled(struct remoteconf *rmconf, void *args __unused) 313 { 314 if (rmconf->nat_traversal) 315 return 1; 316 return 0; 317 } 318 319 void 320 natt_handle_vendorid(struct ph1handle *iph1, int vid_numeric) 321 { 322 if (iph1->rmconf == NULL) { 323 /* Check if any candidate remote conf allows nat-t */ 324 struct rmconfselector rmconf; 325 rmconf_selector_from_ph1(&rmconf, iph1); 326 if (enumrmconf(&rmconf, natt_is_enabled, NULL) == 0) 327 return; 328 } else { 329 if (!iph1->rmconf->nat_traversal) 330 return; 331 } 332 333 if (!iph1->natt_options) 334 iph1->natt_options = racoon_calloc(1, sizeof(*iph1->natt_options)); 335 336 if (!iph1->natt_options) { 337 plog(LLV_ERROR, LOCATION, NULL, 338 "Allocating memory for natt_options failed!\n"); 339 return; 340 } 341 342 if (iph1->natt_options->version < vid_numeric) 343 if (natt_fill_options(iph1->natt_options, vid_numeric) == 0) 344 iph1->natt_flags |= NAT_ANNOUNCED; 345 } 346 347 static void 348 natt_keepalive_delete (struct natt_ka_addrs *ka) 349 { 350 TAILQ_REMOVE (&ka_tree, ka, chain); 351 racoon_free (ka->src); 352 racoon_free (ka->dst); 353 racoon_free (ka); 354 } 355 356 /* NAT keepalive functions */ 357 /*ARGSUSED*/ 358 static void 359 natt_keepalive_send (struct sched *param __unused) 360 { 361 struct natt_ka_addrs *ka, *next = NULL; 362 char keepalive_packet[] = { (char)0xff }; 363 size_t len; 364 int s; 365 366 for (ka = TAILQ_FIRST(&ka_tree); ka; ka = next) { 367 next = TAILQ_NEXT(ka, chain); 368 369 s = myaddr_getfd(ka->src); 370 if (s == -1) { 371 natt_keepalive_delete(ka); 372 continue; 373 } 374 plog (LLV_DEBUG, LOCATION, NULL, "KA: %s\n", 375 saddr2str_fromto("%s->%s", ka->src, ka->dst)); 376 len = sendfromto(s, keepalive_packet, sizeof (keepalive_packet), 377 ka->src, ka->dst, 1); 378 if (len == (size_t)-1) 379 plog(LLV_ERROR, LOCATION, NULL, "KA: sendfromto failed: %s\n", 380 strerror (errno)); 381 } 382 383 sched_schedule (&sc_natt, lcconf->natt_ka_interval, natt_keepalive_send); 384 } 385 386 void 387 natt_keepalive_init (void) 388 { 389 TAILQ_INIT(&ka_tree); 390 391 /* To disable sending KAs set natt_ka_interval=0 */ 392 if (lcconf->natt_ka_interval > 0) 393 sched_schedule (&sc_natt, lcconf->natt_ka_interval, natt_keepalive_send); 394 } 395 396 int 397 natt_keepalive_add (struct sockaddr *src, struct sockaddr *dst) 398 { 399 struct natt_ka_addrs *ka = NULL, *new_addr; 400 401 TAILQ_FOREACH (ka, &ka_tree, chain) { 402 if (cmpsaddr(ka->src, src) == CMPSADDR_MATCH && 403 cmpsaddr(ka->dst, dst) == CMPSADDR_MATCH) { 404 ka->in_use++; 405 plog (LLV_INFO, LOCATION, NULL, "KA found: %s (in_use=%u)\n", 406 saddr2str_fromto("%s->%s", src, dst), ka->in_use); 407 return 0; 408 } 409 } 410 411 plog (LLV_INFO, LOCATION, NULL, "KA list add: %s\n", saddr2str_fromto("%s->%s", src, dst)); 412 413 new_addr = (struct natt_ka_addrs *)racoon_malloc(sizeof(*new_addr)); 414 if (! new_addr) { 415 plog (LLV_ERROR, LOCATION, NULL, "Can't allocate new KA list item\n"); 416 return -1; 417 } 418 419 if ((new_addr->src = dupsaddr(src)) == NULL) { 420 racoon_free(new_addr); 421 plog (LLV_ERROR, LOCATION, NULL, "Can't allocate new KA list item\n"); 422 return -1; 423 } 424 if ((new_addr->dst = dupsaddr(dst)) == NULL) { 425 racoon_free(new_addr); 426 plog (LLV_ERROR, LOCATION, NULL, "Can't allocate new KA list item\n"); 427 return -1; 428 } 429 new_addr->in_use = 1; 430 TAILQ_INSERT_TAIL(&ka_tree, new_addr, chain); 431 432 return 0; 433 } 434 435 int 436 natt_keepalive_add_ph1 (struct ph1handle *iph1) 437 { 438 int ret = 0; 439 440 /* Should only the NATed host send keepalives? 441 If yes, add '(iph1->natt_flags & NAT_DETECTED_ME)' 442 to the following condition. */ 443 if (iph1->natt_flags & NAT_DETECTED && 444 ! (iph1->natt_flags & NAT_KA_QUEUED)) { 445 ret = natt_keepalive_add (iph1->local, iph1->remote); 446 if (ret == 0) 447 iph1->natt_flags |= NAT_KA_QUEUED; 448 } 449 450 return ret; 451 } 452 453 void 454 natt_keepalive_remove (struct sockaddr *src, struct sockaddr *dst) 455 { 456 struct natt_ka_addrs *ka, *next = NULL; 457 458 plog (LLV_INFO, LOCATION, NULL, "KA remove: %s\n", saddr2str_fromto("%s->%s", src, dst)); 459 460 for (ka = TAILQ_FIRST(&ka_tree); ka; ka = next) { 461 next = TAILQ_NEXT(ka, chain); 462 463 plog (LLV_DEBUG, LOCATION, NULL, "KA tree dump: %s (in_use=%u)\n", 464 saddr2str_fromto("%s->%s", src, dst), ka->in_use); 465 466 if (cmpsaddr(ka->src, src) == CMPSADDR_MATCH && 467 cmpsaddr(ka->dst, dst) == CMPSADDR_MATCH && 468 -- ka->in_use <= 0) { 469 470 plog (LLV_DEBUG, LOCATION, NULL, "KA removing this one...\n"); 471 472 natt_keepalive_delete (ka); 473 /* Should we break here? Every pair of addresses should 474 be inserted only once, but who knows :-) Lets traverse 475 the whole list... */ 476 } 477 } 478 } 479 480 /*ARGSUSED*/ 481 static int 482 natt_enabled_in_rmconf_stub (struct remoteconf *rmconf, void *data __unused) 483 { 484 return rmconf->nat_traversal ? 1 : 0; 485 } 486 487 int 488 natt_enabled_in_rmconf () 489 { 490 return enumrmconf(NULL, natt_enabled_in_rmconf_stub, NULL) != 0; 491 } 492 493 494 struct payload_list * 495 isakmp_plist_append_natt_vids (struct payload_list *plist, vchar_t *vid_natt[MAX_NATT_VID_COUNT]){ 496 int i, vid_natt_i = 0; 497 498 if(vid_natt == NULL) 499 return NULL; 500 501 for (i = 0; i < MAX_NATT_VID_COUNT; i++) 502 vid_natt[i]=NULL; 503 504 /* Puts the olders VIDs last, as some implementations may choose the first 505 * NATT VID given 506 */ 507 508 /* Always set RFC VID 509 */ 510 if ((vid_natt[vid_natt_i] = set_vendorid(VENDORID_NATT_RFC)) != NULL) 511 vid_natt_i++; 512 #ifdef ENABLE_NATT_08 513 if ((vid_natt[vid_natt_i] = set_vendorid(VENDORID_NATT_08)) != NULL) 514 vid_natt_i++; 515 #endif 516 #ifdef ENABLE_NATT_07 517 if ((vid_natt[vid_natt_i] = set_vendorid(VENDORID_NATT_07)) != NULL) 518 vid_natt_i++; 519 #endif 520 #ifdef ENABLE_NATT_06 521 if ((vid_natt[vid_natt_i] = set_vendorid(VENDORID_NATT_06)) != NULL) 522 vid_natt_i++; 523 #endif 524 #ifdef ENABLE_NATT_05 525 if ((vid_natt[vid_natt_i] = set_vendorid(VENDORID_NATT_05)) != NULL) 526 vid_natt_i++; 527 #endif 528 #ifdef ENABLE_NATT_04 529 if ((vid_natt[vid_natt_i] = set_vendorid(VENDORID_NATT_04)) != NULL) 530 vid_natt_i++; 531 #endif 532 #ifdef ENABLE_NATT_03 533 if ((vid_natt[vid_natt_i] = set_vendorid(VENDORID_NATT_03)) != NULL) 534 vid_natt_i++; 535 #endif 536 #ifdef ENABLE_NATT_02 537 if ((vid_natt[vid_natt_i] = set_vendorid(VENDORID_NATT_02)) != NULL) 538 vid_natt_i++; 539 if ((vid_natt[vid_natt_i] = set_vendorid(VENDORID_NATT_02_N)) != NULL) 540 vid_natt_i++; 541 #endif 542 #ifdef ENABLE_NATT_01 543 if ((vid_natt[vid_natt_i] = set_vendorid(VENDORID_NATT_01)) != NULL) 544 vid_natt_i++; 545 #endif 546 #ifdef ENABLE_NATT_00 547 if ((vid_natt[vid_natt_i] = set_vendorid(VENDORID_NATT_00)) != NULL) 548 vid_natt_i++; 549 #endif 550 /* set VID payload for NAT-T */ 551 for (i = 0; i < vid_natt_i; i++) 552 plist = isakmp_plist_append(plist, vid_natt[i], ISAKMP_NPTYPE_VID); 553 554 return plist; 555 } 556
Indexes created Thu Jun 11 00:25:07 UTC 2026