1 /* $NetBSD: nattraversal.c,v 1.14 2011/03/14 17:18:13 tteras Exp $ */
2
3 /*
4 * Copyright (C) 2004 SuSE Linux AG, Nuernberg, Germany.
5 * Contributed by: Michal Ludvig <mludvig@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
natt_vendorid(int vid)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 *
natt_hash_addr(struct ph1handle * iph1,struct sockaddr * addr)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
natt_compare_addr_hash(struct ph1handle * iph1,vchar_t * natd_received,int natd_seq)187 natt_compare_addr_hash (struct ph1handle *iph1, vchar_t *natd_received,
188 int natd_seq)
189 {
190 vchar_t *natd_computed;
191 u_int32_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
natt_udp_encap(int encmode)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
natt_fill_options(struct ph1natt_options * opts,int version)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
251 case VENDORID_NATT_02:
252 case VENDORID_NATT_02_N:
253 case VENDORID_NATT_03:
254 opts->float_port = lcconf->port_isakmp_natt;
255 opts->payload_nat_d = ISAKMP_NPTYPE_NATD_DRAFT;
256 opts->payload_nat_oa = ISAKMP_NPTYPE_NATOA_DRAFT;
257 opts->mode_udp_tunnel = IPSECDOI_ATTR_ENC_MODE_UDPTUNNEL_DRAFT;
258 opts->mode_udp_transport = IPSECDOI_ATTR_ENC_MODE_UDPTRNS_DRAFT;
259 opts->encaps_type = UDP_ENCAP_ESPINUDP;
260 break;
261 case VENDORID_NATT_04:
262 case VENDORID_NATT_05:
263 case VENDORID_NATT_06:
264 case VENDORID_NATT_07:
265 case VENDORID_NATT_08:
266 opts->float_port = lcconf->port_isakmp_natt;
267 opts->payload_nat_d = ISAKMP_NPTYPE_NATD_BADDRAFT;
268 opts->payload_nat_oa = ISAKMP_NPTYPE_NATOA_BADDRAFT;
269 opts->mode_udp_tunnel = IPSECDOI_ATTR_ENC_MODE_UDPTUNNEL_RFC;
270 opts->mode_udp_transport = IPSECDOI_ATTR_ENC_MODE_UDPTRNS_RFC;
271 opts->encaps_type = UDP_ENCAP_ESPINUDP;
272 break;
273 case VENDORID_NATT_RFC:
274 opts->float_port = lcconf->port_isakmp_natt;
275 opts->payload_nat_d = ISAKMP_NPTYPE_NATD_RFC;
276 opts->payload_nat_oa = ISAKMP_NPTYPE_NATOA_RFC;
277 opts->mode_udp_tunnel = IPSECDOI_ATTR_ENC_MODE_UDPTUNNEL_RFC;
278 opts->mode_udp_transport = IPSECDOI_ATTR_ENC_MODE_UDPTRNS_RFC;
279 opts->encaps_type = UDP_ENCAP_ESPINUDP;
280 break;
281 default:
282 plog(LLV_ERROR, LOCATION, NULL,
283 "unsupported NAT-T version: %s\n",
284 vid_string_by_id(version));
285 return -1;
286 }
287
288 opts->mode_udp_diff = opts->mode_udp_tunnel - IPSECDOI_ATTR_ENC_MODE_TUNNEL;
289
290 return 0;
291 }
292
293 void
natt_float_ports(struct ph1handle * iph1)294 natt_float_ports (struct ph1handle *iph1)
295 {
296 if (! (iph1->natt_flags & NAT_DETECTED) )
297 return;
298 if (! iph1->natt_options->float_port){
299 /* Drafts 00 / 01, just schedule keepalive */
300 natt_keepalive_add_ph1 (iph1);
301 return;
302 }
303
304 set_port (iph1->local, iph1->natt_options->float_port);
305 set_port (iph1->remote, iph1->natt_options->float_port);
306 iph1->natt_flags |= NAT_PORTS_CHANGED | NAT_ADD_NON_ESP_MARKER;
307
308 natt_keepalive_add_ph1 (iph1);
309 }
310
311 static int
natt_is_enabled(struct remoteconf * rmconf,void * args)312 natt_is_enabled (struct remoteconf *rmconf, void *args)
313 {
314 if (rmconf->nat_traversal)
315 return 1;
316 return 0;
317 }
318
319 void
natt_handle_vendorid(struct ph1handle * iph1,int vid_numeric)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
natt_keepalive_delete(struct natt_ka_addrs * ka)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 static void
natt_keepalive_send(struct sched * param)358 natt_keepalive_send (struct sched *param)
359 {
360 struct natt_ka_addrs *ka, *next = NULL;
361 char keepalive_packet[] = { 0xff };
362 size_t len;
363 int s;
364
365 for (ka = TAILQ_FIRST(&ka_tree); ka; ka = next) {
366 next = TAILQ_NEXT(ka, chain);
367
368 s = myaddr_getfd(ka->src);
369 if (s == -1) {
370 natt_keepalive_delete(ka);
371 continue;
372 }
373 plog (LLV_DEBUG, LOCATION, NULL, "KA: %s\n",
374 saddr2str_fromto("%s->%s", ka->src, ka->dst));
375 len = sendfromto(s, keepalive_packet, sizeof (keepalive_packet),
376 ka->src, ka->dst, 1);
377 if (len == -1)
378 plog(LLV_ERROR, LOCATION, NULL, "KA: sendfromto failed: %s\n",
379 strerror (errno));
380 }
381
382 sched_schedule (&sc_natt, lcconf->natt_ka_interval, natt_keepalive_send);
383 }
384
385 void
natt_keepalive_init(void)386 natt_keepalive_init (void)
387 {
388 TAILQ_INIT(&ka_tree);
389
390 /* To disable sending KAs set natt_ka_interval=0 */
391 if (lcconf->natt_ka_interval > 0)
392 sched_schedule (&sc_natt, lcconf->natt_ka_interval, natt_keepalive_send);
393 }
394
395 int
natt_keepalive_add(struct sockaddr * src,struct sockaddr * dst)396 natt_keepalive_add (struct sockaddr *src, struct sockaddr *dst)
397 {
398 struct natt_ka_addrs *ka = NULL, *new_addr;
399
400 TAILQ_FOREACH (ka, &ka_tree, chain) {
401 if (cmpsaddr(ka->src, src) == CMPSADDR_MATCH &&
402 cmpsaddr(ka->dst, dst) == CMPSADDR_MATCH) {
403 ka->in_use++;
404 plog (LLV_INFO, LOCATION, NULL, "KA found: %s (in_use=%u)\n",
405 saddr2str_fromto("%s->%s", src, dst), ka->in_use);
406 return 0;
407 }
408 }
409
410 plog (LLV_INFO, LOCATION, NULL, "KA list add: %s\n", saddr2str_fromto("%s->%s", src, dst));
411
412 new_addr = (struct natt_ka_addrs *)racoon_malloc(sizeof(*new_addr));
413 if (! new_addr) {
414 plog (LLV_ERROR, LOCATION, NULL, "Can't allocate new KA list item\n");
415 return -1;
416 }
417
418 if ((new_addr->src = dupsaddr(src)) == NULL) {
419 racoon_free(new_addr);
420 plog (LLV_ERROR, LOCATION, NULL, "Can't allocate new KA list item\n");
421 return -1;
422 }
423 if ((new_addr->dst = dupsaddr(dst)) == NULL) {
424 racoon_free(new_addr);
425 plog (LLV_ERROR, LOCATION, NULL, "Can't allocate new KA list item\n");
426 return -1;
427 }
428 new_addr->in_use = 1;
429 TAILQ_INSERT_TAIL(&ka_tree, new_addr, chain);
430
431 return 0;
432 }
433
434 int
natt_keepalive_add_ph1(struct ph1handle * iph1)435 natt_keepalive_add_ph1 (struct ph1handle *iph1)
436 {
437 int ret = 0;
438
439 /* Should only the NATed host send keepalives?
440 If yes, add '(iph1->natt_flags & NAT_DETECTED_ME)'
441 to the following condition. */
442 if (iph1->natt_flags & NAT_DETECTED &&
443 ! (iph1->natt_flags & NAT_KA_QUEUED)) {
444 ret = natt_keepalive_add (iph1->local, iph1->remote);
445 if (ret == 0)
446 iph1->natt_flags |= NAT_KA_QUEUED;
447 }
448
449 return ret;
450 }
451
452 void
natt_keepalive_remove(struct sockaddr * src,struct sockaddr * dst)453 natt_keepalive_remove (struct sockaddr *src, struct sockaddr *dst)
454 {
455 struct natt_ka_addrs *ka, *next = NULL;
456
457 plog (LLV_INFO, LOCATION, NULL, "KA remove: %s\n", saddr2str_fromto("%s->%s", src, dst));
458
459 for (ka = TAILQ_FIRST(&ka_tree); ka; ka = next) {
460 next = TAILQ_NEXT(ka, chain);
461
462 plog (LLV_DEBUG, LOCATION, NULL, "KA tree dump: %s (in_use=%u)\n",
463 saddr2str_fromto("%s->%s", src, dst), ka->in_use);
464
465 if (cmpsaddr(ka->src, src) == CMPSADDR_MATCH &&
466 cmpsaddr(ka->dst, dst) == CMPSADDR_MATCH &&
467 -- ka->in_use <= 0) {
468
469 plog (LLV_DEBUG, LOCATION, NULL, "KA removing this one...\n");
470
471 natt_keepalive_delete (ka);
472 /* Should we break here? Every pair of addresses should
473 be inserted only once, but who knows :-) Lets traverse
474 the whole list... */
475 }
476 }
477 }
478
479 static int
natt_enabled_in_rmconf_stub(struct remoteconf * rmconf,void * data)480 natt_enabled_in_rmconf_stub (struct remoteconf *rmconf, void *data)
481 {
482 return rmconf->nat_traversal ? 1 : 0;
483 }
484
485 int
natt_enabled_in_rmconf()486 natt_enabled_in_rmconf ()
487 {
488 return enumrmconf(NULL, natt_enabled_in_rmconf_stub, NULL) != 0;
489 }
490
491
492 struct payload_list *
isakmp_plist_append_natt_vids(struct payload_list * plist,vchar_t * vid_natt[MAX_NATT_VID_COUNT])493 isakmp_plist_append_natt_vids (struct payload_list *plist, vchar_t *vid_natt[MAX_NATT_VID_COUNT]){
494 int i, vid_natt_i = 0;
495
496 if(vid_natt == NULL)
497 return NULL;
498
499 for (i = 0; i < MAX_NATT_VID_COUNT; i++)
500 vid_natt[i]=NULL;
501
502 /* Puts the olders VIDs last, as some implementations may choose the first
503 * NATT VID given
504 */
505
506 /* Always set RFC VID
507 */
508 if ((vid_natt[vid_natt_i] = set_vendorid(VENDORID_NATT_RFC)) != NULL)
509 vid_natt_i++;
510 #ifdef ENABLE_NATT_08
511 if ((vid_natt[vid_natt_i] = set_vendorid(VENDORID_NATT_08)) != NULL)
512 vid_natt_i++;
513 #endif
514 #ifdef ENABLE_NATT_07
515 if ((vid_natt[vid_natt_i] = set_vendorid(VENDORID_NATT_07)) != NULL)
516 vid_natt_i++;
517 #endif
518 #ifdef ENABLE_NATT_06
519 if ((vid_natt[vid_natt_i] = set_vendorid(VENDORID_NATT_06)) != NULL)
520 vid_natt_i++;
521 #endif
522 #ifdef ENABLE_NATT_05
523 if ((vid_natt[vid_natt_i] = set_vendorid(VENDORID_NATT_05)) != NULL)
524 vid_natt_i++;
525 #endif
526 #ifdef ENABLE_NATT_04
527 if ((vid_natt[vid_natt_i] = set_vendorid(VENDORID_NATT_04)) != NULL)
528 vid_natt_i++;
529 #endif
530 #ifdef ENABLE_NATT_03
531 if ((vid_natt[vid_natt_i] = set_vendorid(VENDORID_NATT_03)) != NULL)
532 vid_natt_i++;
533 #endif
534 #ifdef ENABLE_NATT_02
535 if ((vid_natt[vid_natt_i] = set_vendorid(VENDORID_NATT_02)) != NULL)
536 vid_natt_i++;
537 if ((vid_natt[vid_natt_i] = set_vendorid(VENDORID_NATT_02_N)) != NULL)
538 vid_natt_i++;
539 #endif
540 #ifdef ENABLE_NATT_01
541 if ((vid_natt[vid_natt_i] = set_vendorid(VENDORID_NATT_01)) != NULL)
542 vid_natt_i++;
543 #endif
544 #ifdef ENABLE_NATT_00
545 if ((vid_natt[vid_natt_i] = set_vendorid(VENDORID_NATT_00)) != NULL)
546 vid_natt_i++;
547 #endif
548 /* set VID payload for NAT-T */
549 for (i = 0; i < vid_natt_i; i++)
550 plist = isakmp_plist_append(plist, vid_natt[i], ISAKMP_NPTYPE_VID);
551
552 return plist;
553 }
554