/* $NetBSD: nattraversal.c,v 1.14 2011/03/14 17:18:13 tteras Exp $ */
/*
* Copyright (C) 2004 SuSE Linux AG, Nuernberg, Germany.
* Contributed by: Michal Ludvig <mludvig@suse.cz>, SUSE Labs
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the project nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "config.h"
#include <sys/types.h>
#include <sys/param.h>
#ifdef __linux__
#include <linux/udp.h>
#endif
#if defined(__NetBSD__) || defined (__FreeBSD__)
#include <netinet/udp.h>
#endif
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <ctype.h>
#include "var.h"
#include "misc.h"
#include "vmbuf.h"
#include "plog.h"
#include "debug.h"
#include "localconf.h"
#include "remoteconf.h"
#include "sockmisc.h"
#include "isakmp_var.h"
#include "isakmp.h"
#include "oakley.h"
#include "ipsec_doi.h"
#include "vendorid.h"
#include "handler.h"
#include "crypto_openssl.h"
#include "schedule.h"
#include "nattraversal.h"
#include "grabmyaddr.h"
struct natt_ka_addrs {
struct sockaddr *src;
struct sockaddr *dst;
unsigned in_use;
TAILQ_ENTRY(natt_ka_addrs) chain;
};
static TAILQ_HEAD(_natt_ka_addrs, natt_ka_addrs) ka_tree;
static struct sched sc_natt = SCHED_INITIALIZER();
/*
* check if the given vid is NAT-T.
*/
int
natt_vendorid (int vid)
{
return (
#ifdef ENABLE_NATT_00
vid == VENDORID_NATT_00 ||
#endif
#ifdef ENABLE_NATT_01
vid == VENDORID_NATT_01 ||
#endif
#ifdef ENABLE_NATT_02
vid == VENDORID_NATT_02 ||
vid == VENDORID_NATT_02_N ||
#endif
#ifdef ENABLE_NATT_03
vid == VENDORID_NATT_03 ||
#endif
#ifdef ENABLE_NATT_04
vid == VENDORID_NATT_04 ||
#endif
#ifdef ENABLE_NATT_05
vid == VENDORID_NATT_05 ||
#endif
#ifdef ENABLE_NATT_06
vid == VENDORID_NATT_06 ||
#endif
#ifdef ENABLE_NATT_07
vid == VENDORID_NATT_07 ||
#endif
#ifdef ENABLE_NATT_08
vid == VENDORID_NATT_08 ||
#endif
/* Always enable NATT RFC if ENABLE_NATT
*/
vid == VENDORID_NATT_RFC);
}
vchar_t *
natt_hash_addr (struct ph1handle *iph1, struct sockaddr *addr)
{
vchar_t *natd;
vchar_t *buf;
char *ptr;
void *addr_ptr, *addr_port;
size_t buf_size, addr_size;
int natt_force = 0;
if (iph1->rmconf != NULL && iph1->rmconf->nat_traversal == NATT_FORCE)
natt_force = 1;
plog (LLV_INFO, LOCATION, addr, "Hashing %s with algo #%d %s\n",
saddr2str(addr), iph1->approval->hashtype,
natt_force?"(NAT-T forced)":"");
if (addr->sa_family == AF_INET) {
addr_size = sizeof (struct in_addr); /* IPv4 address */
addr_ptr = &((struct sockaddr_in *)addr)->sin_addr;
addr_port = &((struct sockaddr_in *)addr)->sin_port;
}
else if (addr->sa_family == AF_INET6) {
addr_size = sizeof (struct in6_addr); /* IPv6 address */
addr_ptr = &((struct sockaddr_in6 *)addr)->sin6_addr;
addr_port = &((struct sockaddr_in6 *)addr)->sin6_port;
}
else {
plog (LLV_ERROR, LOCATION, addr, "Unsupported address family #0x%x\n", addr->sa_family);
return NULL;
}
buf_size = 2 * sizeof (cookie_t); /* CKY-I + CKY+R */
buf_size += addr_size + 2; /* Address + Port */
if ((buf = vmalloc (buf_size)) == NULL)
return NULL;
ptr = buf->v;
/* Copy-in CKY-I */
memcpy (ptr, iph1->index.i_ck, sizeof (cookie_t));
ptr += sizeof (cookie_t);
/* Copy-in CKY-I */
memcpy (ptr, iph1->index.r_ck, sizeof (cookie_t));
ptr += sizeof (cookie_t);
/* Copy-in Address (or zeroes if NATT_FORCE) */
if (natt_force)
memset (ptr, 0, addr_size);
else
memcpy (ptr, addr_ptr, addr_size);
ptr += addr_size;
/* Copy-in Port number */
memcpy (ptr, addr_port, 2);
natd = oakley_hash (buf, iph1);
vfree(buf);
return natd;
}
int
natt_compare_addr_hash (struct ph1handle *iph1, vchar_t *natd_received,
int natd_seq)
{
vchar_t *natd_computed;
u_int32_t flag;
int verified = 0;
if (iph1->rmconf != NULL &&
iph1->rmconf->nat_traversal == NATT_FORCE)
return verified;
if (natd_seq == 0) {
natd_computed = natt_hash_addr (iph1, iph1->local);
flag = NAT_DETECTED_ME;
}
else {
natd_computed = natt_hash_addr (iph1, iph1->remote);
flag = NAT_DETECTED_PEER;
}
if (natd_computed == NULL) {
plog(LLV_ERROR, LOCATION, NULL, "natd_computed allocation failed\n");
return verified; /* XXX should abort */
}
if (natd_received->l == natd_computed->l &&
memcmp (natd_received->v, natd_computed->v, natd_received->l) == 0) {
iph1->natt_flags &= ~flag;
verified = 1;
}
vfree (natd_computed);
return verified;
}
int
natt_udp_encap (int encmode)
{
return (encmode == IPSECDOI_ATTR_ENC_MODE_UDPTUNNEL_RFC ||
encmode == IPSECDOI_ATTR_ENC_MODE_UDPTRNS_RFC ||
encmode == IPSECDOI_ATTR_ENC_MODE_UDPTUNNEL_DRAFT ||
encmode == IPSECDOI_ATTR_ENC_MODE_UDPTRNS_DRAFT);
}
int
natt_fill_options (struct ph1natt_options *opts, int version)
{
if (! opts)
return -1;
opts->version = version;
switch (version) {
case VENDORID_NATT_00:
case VENDORID_NATT_01:
opts->float_port = 0; /* No port floating for those drafts */
opts->payload_nat_d = ISAKMP_NPTYPE_NATD_DRAFT;
opts->payload_nat_oa = ISAKMP_NPTYPE_NATOA_DRAFT;
opts->mode_udp_tunnel = IPSECDOI_ATTR_ENC_MODE_UDPTUNNEL_DRAFT;
opts->mode_udp_transport = IPSECDOI_ATTR_ENC_MODE_UDPTRNS_DRAFT;
opts->encaps_type = UDP_ENCAP_ESPINUDP_NON_IKE;
break;
case VENDORID_NATT_02:
case VENDORID_NATT_02_N:
case VENDORID_NATT_03:
opts->float_port = lcconf->port_isakmp_natt;
opts->payload_nat_d = ISAKMP_NPTYPE_NATD_DRAFT;
opts->payload_nat_oa = ISAKMP_NPTYPE_NATOA_DRAFT;
opts->mode_udp_tunnel = IPSECDOI_ATTR_ENC_MODE_UDPTUNNEL_DRAFT;
opts->mode_udp_transport = IPSECDOI_ATTR_ENC_MODE_UDPTRNS_DRAFT;
opts->encaps_type = UDP_ENCAP_ESPINUDP;
break;
case VENDORID_NATT_04:
case VENDORID_NATT_05:
case VENDORID_NATT_06:
case VENDORID_NATT_07:
case VENDORID_NATT_08:
opts->float_port = lcconf->port_isakmp_natt;
opts->payload_nat_d = ISAKMP_NPTYPE_NATD_BADDRAFT;
opts->payload_nat_oa = ISAKMP_NPTYPE_NATOA_BADDRAFT;
opts->mode_udp_tunnel = IPSECDOI_ATTR_ENC_MODE_UDPTUNNEL_RFC;
opts->mode_udp_transport = IPSECDOI_ATTR_ENC_MODE_UDPTRNS_RFC;
opts->encaps_type = UDP_ENCAP_ESPINUDP;
break;
case VENDORID_NATT_RFC:
opts->float_port = lcconf->port_isakmp_natt;
opts->payload_nat_d = ISAKMP_NPTYPE_NATD_RFC;
opts->payload_nat_oa = ISAKMP_NPTYPE_NATOA_RFC;
opts->mode_udp_tunnel = IPSECDOI_ATTR_ENC_MODE_UDPTUNNEL_RFC;
opts->mode_udp_transport = IPSECDOI_ATTR_ENC_MODE_UDPTRNS_RFC;
opts->encaps_type = UDP_ENCAP_ESPINUDP;
break;
default:
plog(LLV_ERROR, LOCATION, NULL,
"unsupported NAT-T version: %s\n",
vid_string_by_id(version));
return -1;
}
opts->mode_udp_diff = opts->mode_udp_tunnel - IPSECDOI_ATTR_ENC_MODE_TUNNEL;
return 0;
}
void
natt_float_ports (struct ph1handle *iph1)
{
if (! (iph1->natt_flags & NAT_DETECTED) )
return;
if (! iph1->natt_options->float_port){
/* Drafts 00 / 01, just schedule keepalive */
natt_keepalive_add_ph1 (iph1);
return;
}
set_port (iph1->local, iph1->natt_options->float_port);
set_port (iph1->remote, iph1->natt_options->float_port);
iph1->natt_flags |= NAT_PORTS_CHANGED | NAT_ADD_NON_ESP_MARKER;
natt_keepalive_add_ph1 (iph1);
}
static int
natt_is_enabled (struct remoteconf *rmconf, void *args)
{
if (rmconf->nat_traversal)
return 1;
return 0;
}
void
natt_handle_vendorid (struct ph1handle *iph1, int vid_numeric)
{
if (iph1->rmconf == NULL) {
/* Check if any candidate remote conf allows nat-t */
struct rmconfselector rmconf;
rmconf_selector_from_ph1(&rmconf, iph1);
if (enumrmconf(&rmconf, natt_is_enabled, NULL) == 0)
return;
} else {
if (!iph1->rmconf->nat_traversal)
return;
}
if (! iph1->natt_options)
iph1->natt_options = racoon_calloc (1, sizeof (*iph1->natt_options));
if (! iph1->natt_options) {
plog (LLV_ERROR, LOCATION, NULL,
"Allocating memory for natt_options failed!\n");
return;
}
if (iph1->natt_options->version < vid_numeric)
if (natt_fill_options (iph1->natt_options, vid_numeric) == 0)
iph1->natt_flags |= NAT_ANNOUNCED;
}
static void
natt_keepalive_delete (struct natt_ka_addrs *ka)
{
TAILQ_REMOVE (&ka_tree, ka, chain);
racoon_free (ka->src);
racoon_free (ka->dst);
racoon_free (ka);
}
/* NAT keepalive functions */
static void
natt_keepalive_send (struct sched *param)
{
struct natt_ka_addrs *ka, *next = NULL;
char keepalive_packet[] = { 0xff };
size_t len;
int s;
for (ka = TAILQ_FIRST(&ka_tree); ka; ka = next) {
next = TAILQ_NEXT(ka, chain);
s = myaddr_getfd(ka->src);
if (s == -1) {
natt_keepalive_delete(ka);
continue;
}
plog (LLV_DEBUG, LOCATION, NULL, "KA: %s\n",
saddr2str_fromto("%s->%s", ka->src, ka->dst));
len = sendfromto(s, keepalive_packet, sizeof (keepalive_packet),
ka->src, ka->dst, 1);
if (len == -1)
plog(LLV_ERROR, LOCATION, NULL, "KA: sendfromto failed: %s\n",
strerror (errno));
}
sched_schedule (&sc_natt, lcconf->natt_ka_interval, natt_keepalive_send);
}
void
natt_keepalive_init (void)
{
TAILQ_INIT(&ka_tree);
/* To disable sending KAs set natt_ka_interval=0 */
if (lcconf->natt_ka_interval > 0)
sched_schedule (&sc_natt, lcconf->natt_ka_interval, natt_keepalive_send);
}
int
natt_keepalive_add (struct sockaddr *src, struct sockaddr *dst)
{
struct natt_ka_addrs *ka = NULL, *new_addr;
TAILQ_FOREACH (ka, &ka_tree, chain) {
if (cmpsaddr(ka->src, src) == CMPSADDR_MATCH &&
cmpsaddr(ka->dst, dst) == CMPSADDR_MATCH) {
ka->in_use++;
plog (LLV_INFO, LOCATION, NULL, "KA found: %s (in_use=%u)\n",
saddr2str_fromto("%s->%s", src, dst), ka->in_use);
return 0;
}
}
plog (LLV_INFO, LOCATION, NULL, "KA list add: %s\n", saddr2str_fromto("%s->%s", src, dst));
new_addr = (struct natt_ka_addrs *)racoon_malloc(sizeof(*new_addr));
if (! new_addr) {
plog (LLV_ERROR, LOCATION, NULL, "Can't allocate new KA list item\n");
return -1;
}
if ((new_addr->src = dupsaddr(src)) == NULL) {
racoon_free(new_addr);
plog (LLV_ERROR, LOCATION, NULL, "Can't allocate new KA list item\n");
return -1;
}
if ((new_addr->dst = dupsaddr(dst)) == NULL) {
racoon_free(new_addr);
plog (LLV_ERROR, LOCATION, NULL, "Can't allocate new KA list item\n");
return -1;
}
new_addr->in_use = 1;
TAILQ_INSERT_TAIL(&ka_tree, new_addr, chain);
return 0;
}
int
natt_keepalive_add_ph1 (struct ph1handle *iph1)
{
int ret = 0;
/* Should only the NATed host send keepalives?
If yes, add '(iph1->natt_flags & NAT_DETECTED_ME)'
to the following condition. */
if (iph1->natt_flags & NAT_DETECTED &&
! (iph1->natt_flags & NAT_KA_QUEUED)) {
ret = natt_keepalive_add (iph1->local, iph1->remote);
if (ret == 0)
iph1->natt_flags |= NAT_KA_QUEUED;
}
return ret;
}
void
natt_keepalive_remove (struct sockaddr *src, struct sockaddr *dst)
{
struct natt_ka_addrs *ka, *next = NULL;
plog (LLV_INFO, LOCATION, NULL, "KA remove: %s\n", saddr2str_fromto("%s->%s", src, dst));
for (ka = TAILQ_FIRST(&ka_tree); ka; ka = next) {
next = TAILQ_NEXT(ka, chain);
plog (LLV_DEBUG, LOCATION, NULL, "KA tree dump: %s (in_use=%u)\n",
saddr2str_fromto("%s->%s", src, dst), ka->in_use);
if (cmpsaddr(ka->src, src) == CMPSADDR_MATCH &&
cmpsaddr(ka->dst, dst) == CMPSADDR_MATCH &&
-- ka->in_use <= 0) {
plog (LLV_DEBUG, LOCATION, NULL, "KA removing this one...\n");
natt_keepalive_delete (ka);
/* Should we break here? Every pair of addresses should
be inserted only once, but who knows :-) Lets traverse
the whole list... */
}
}
}
static int
natt_enabled_in_rmconf_stub (struct remoteconf *rmconf, void *data)
{
return rmconf->nat_traversal ? 1 : 0;
}
int
natt_enabled_in_rmconf ()
{
return enumrmconf(NULL, natt_enabled_in_rmconf_stub, NULL) != 0;
}
struct payload_list *
isakmp_plist_append_natt_vids (struct payload_list *plist, vchar_t *vid_natt[MAX_NATT_VID_COUNT]){
int i, vid_natt_i = 0;
if(vid_natt == NULL)
return NULL;
for (i = 0; i < MAX_NATT_VID_COUNT; i++)
vid_natt[i]=NULL;
/* Puts the olders VIDs last, as some implementations may choose the first
* NATT VID given
*/
/* Always set RFC VID
*/
if ((vid_natt[vid_natt_i] = set_vendorid(VENDORID_NATT_RFC)) != NULL)
vid_natt_i++;
#ifdef ENABLE_NATT_08
if ((vid_natt[vid_natt_i] = set_vendorid(VENDORID_NATT_08)) != NULL)
vid_natt_i++;
#endif
#ifdef ENABLE_NATT_07
if ((vid_natt[vid_natt_i] = set_vendorid(VENDORID_NATT_07)) != NULL)
vid_natt_i++;
#endif
#ifdef ENABLE_NATT_06
if ((vid_natt[vid_natt_i] = set_vendorid(VENDORID_NATT_06)) != NULL)
vid_natt_i++;
#endif
#ifdef ENABLE_NATT_05
if ((vid_natt[vid_natt_i] = set_vendorid(VENDORID_NATT_05)) != NULL)
vid_natt_i++;
#endif
#ifdef ENABLE_NATT_04
if ((vid_natt[vid_natt_i] = set_vendorid(VENDORID_NATT_04)) != NULL)
vid_natt_i++;
#endif
#ifdef ENABLE_NATT_03
if ((vid_natt[vid_natt_i] = set_vendorid(VENDORID_NATT_03)) != NULL)
vid_natt_i++;
#endif
#ifdef ENABLE_NATT_02
if ((vid_natt[vid_natt_i] = set_vendorid(VENDORID_NATT_02)) != NULL)
vid_natt_i++;
if ((vid_natt[vid_natt_i] = set_vendorid(VENDORID_NATT_02_N)) != NULL)
vid_natt_i++;
#endif
#ifdef ENABLE_NATT_01
if ((vid_natt[vid_natt_i] = set_vendorid(VENDORID_NATT_01)) != NULL)
vid_natt_i++;
#endif
#ifdef ENABLE_NATT_00
if ((vid_natt[vid_natt_i] = set_vendorid(VENDORID_NATT_00)) != NULL)
vid_natt_i++;
#endif
/* set VID payload for NAT-T */
for (i = 0; i < vid_natt_i; i++)
plist = isakmp_plist_append(plist, vid_natt[i], ISAKMP_NPTYPE_VID);
return plist;
}