source: rtems-libbsd/ipsec-tools/src/racoon/nattraversal.c @ ff36f5e

55-freebsd-126-freebsd-12
Last change on this file since ff36f5e was ff36f5e, checked in by Christian Mauderer <christian.mauderer@…>, on 05/30/18 at 12:27:35

Import ipsec-tools 0.8.2.

Import unchanged ipsec-tools sources in the release version 0.8.2. The
homepage of ipsec-tools is ​http://ipsec-tools.sourceforge.net/. The
sources can be obtained from there.
  • Property mode set to 100644
File size: 14.9 KB
Line 
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
71struct 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
79static TAILQ_HEAD(_natt_ka_addrs, natt_ka_addrs) ka_tree;
80static struct sched sc_natt = SCHED_INITIALIZER();
81
82/*
83 * check if the given vid is NAT-T.
84 */
85int
86natt_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
122vchar_t *
123natt_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
186int
187natt_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
223int
224natt_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
232int
233natt_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
293void
294natt_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
311static int
312natt_is_enabled (struct remoteconf *rmconf, void *args)
313{
314  if (rmconf->nat_traversal)
315    return 1;
316  return 0;
317}
318
319void
320natt_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
347static void
348natt_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 */
357static void
358natt_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
385void
386natt_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
395int
396natt_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
434int
435natt_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
452void
453natt_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
479static int
480natt_enabled_in_rmconf_stub (struct remoteconf *rmconf, void *data)
481{
482  return rmconf->nat_traversal ? 1 : 0;
483}
484
485int
486natt_enabled_in_rmconf ()
487{
488  return enumrmconf(NULL, natt_enabled_in_rmconf_stub, NULL) != 0;
489}
490
491
492struct payload_list *
493isakmp_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}
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