466 lines
12 KiB
C
466 lines
12 KiB
C
/*
|
|
* Copyright (C) 2006-2007 Martin Willi
|
|
* Copyright (C) 2006 Tobias Brunner, Daniel Roethlisberger
|
|
* Hochschule fuer Technik Rapperswil
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify it
|
|
* under the terms of the GNU General Public License as published by the
|
|
* Free Software Foundation; either version 2 of the License, or (at your
|
|
* option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
|
|
*
|
|
* This program is distributed in the hope that it will be useful, but
|
|
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
|
|
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
|
* for more details.
|
|
*/
|
|
|
|
#include "ike_natd.h"
|
|
|
|
#include <string.h>
|
|
|
|
#include <hydra.h>
|
|
#include <daemon.h>
|
|
#include <config/peer_cfg.h>
|
|
#include <crypto/hashers/hasher.h>
|
|
#include <encoding/payloads/notify_payload.h>
|
|
|
|
|
|
typedef struct private_ike_natd_t private_ike_natd_t;
|
|
|
|
/**
|
|
* Private members of a ike_natd_t task.
|
|
*/
|
|
struct private_ike_natd_t {
|
|
|
|
/**
|
|
* Public methods and task_t interface.
|
|
*/
|
|
ike_natd_t public;
|
|
|
|
/**
|
|
* Assigned IKE_SA.
|
|
*/
|
|
ike_sa_t *ike_sa;
|
|
|
|
/**
|
|
* Are we the initiator?
|
|
*/
|
|
bool initiator;
|
|
|
|
/**
|
|
* Hasher used to build NAT detection hashes
|
|
*/
|
|
hasher_t *hasher;
|
|
|
|
/**
|
|
* Did we process any NAT detection notifys for a source address?
|
|
*/
|
|
bool src_seen;
|
|
|
|
/**
|
|
* Did we process any NAT detection notifys for a destination address?
|
|
*/
|
|
bool dst_seen;
|
|
|
|
/**
|
|
* Have we found a matching source address NAT hash?
|
|
*/
|
|
bool src_matched;
|
|
|
|
/**
|
|
* Have we found a matching destination address NAT hash?
|
|
*/
|
|
bool dst_matched;
|
|
|
|
/**
|
|
* whether NAT mappings for our NATed address has changed
|
|
*/
|
|
bool mapping_changed;
|
|
};
|
|
|
|
|
|
/**
|
|
* Build NAT detection hash for a host
|
|
*/
|
|
static chunk_t generate_natd_hash(private_ike_natd_t *this,
|
|
ike_sa_id_t *ike_sa_id, host_t *host)
|
|
{
|
|
chunk_t natd_chunk, spi_i_chunk, spi_r_chunk, addr_chunk, port_chunk;
|
|
chunk_t natd_hash;
|
|
u_int64_t spi_i, spi_r;
|
|
u_int16_t port;
|
|
|
|
/* prepare all required chunks */
|
|
spi_i = ike_sa_id->get_initiator_spi(ike_sa_id);
|
|
spi_r = ike_sa_id->get_responder_spi(ike_sa_id);
|
|
spi_i_chunk.ptr = (void*)&spi_i;
|
|
spi_i_chunk.len = sizeof(spi_i);
|
|
spi_r_chunk.ptr = (void*)&spi_r;
|
|
spi_r_chunk.len = sizeof(spi_r);
|
|
port = htons(host->get_port(host));
|
|
port_chunk.ptr = (void*)&port;
|
|
port_chunk.len = sizeof(port);
|
|
addr_chunk = host->get_address(host);
|
|
|
|
/* natd_hash = SHA1( spi_i | spi_r | address | port ) */
|
|
natd_chunk = chunk_cat("cccc", spi_i_chunk, spi_r_chunk, addr_chunk, port_chunk);
|
|
this->hasher->allocate_hash(this->hasher, natd_chunk, &natd_hash);
|
|
DBG3(DBG_IKE, "natd_chunk %B", &natd_chunk);
|
|
DBG3(DBG_IKE, "natd_hash %B", &natd_hash);
|
|
|
|
chunk_free(&natd_chunk);
|
|
return natd_hash;
|
|
}
|
|
|
|
/**
|
|
* build a faked NATD payload to enforce UDP encap
|
|
*/
|
|
static chunk_t generate_natd_hash_faked(private_ike_natd_t *this)
|
|
{
|
|
rng_t *rng;
|
|
chunk_t chunk;
|
|
|
|
rng = lib->crypto->create_rng(lib->crypto, RNG_WEAK);
|
|
if (!rng)
|
|
{
|
|
DBG1(DBG_IKE, "unable to get random bytes for NATD fake");
|
|
return chunk_empty;
|
|
}
|
|
rng->allocate_bytes(rng, HASH_SIZE_SHA1, &chunk);
|
|
rng->destroy(rng);
|
|
return chunk;
|
|
}
|
|
|
|
/**
|
|
* Build a NAT detection notify payload.
|
|
*/
|
|
static notify_payload_t *build_natd_payload(private_ike_natd_t *this,
|
|
notify_type_t type, host_t *host)
|
|
{
|
|
chunk_t hash;
|
|
notify_payload_t *notify;
|
|
ike_sa_id_t *ike_sa_id;
|
|
ike_cfg_t *config;
|
|
|
|
ike_sa_id = this->ike_sa->get_id(this->ike_sa);
|
|
config = this->ike_sa->get_ike_cfg(this->ike_sa);
|
|
if (config->force_encap(config) && type == NAT_DETECTION_SOURCE_IP)
|
|
{
|
|
hash = generate_natd_hash_faked(this);
|
|
}
|
|
else
|
|
{
|
|
hash = generate_natd_hash(this, ike_sa_id, host);
|
|
}
|
|
notify = notify_payload_create();
|
|
notify->set_notify_type(notify, type);
|
|
notify->set_notification_data(notify, hash);
|
|
chunk_free(&hash);
|
|
|
|
return notify;
|
|
}
|
|
|
|
/**
|
|
* read notifys from message and evaluate them
|
|
*/
|
|
static void process_payloads(private_ike_natd_t *this, message_t *message)
|
|
{
|
|
enumerator_t *enumerator;
|
|
payload_t *payload;
|
|
notify_payload_t *notify;
|
|
chunk_t hash, src_hash, dst_hash;
|
|
ike_sa_id_t *ike_sa_id;
|
|
host_t *me, *other;
|
|
ike_cfg_t *config;
|
|
|
|
/* Precompute NAT-D hashes for incoming NAT notify comparison */
|
|
ike_sa_id = message->get_ike_sa_id(message);
|
|
me = message->get_destination(message);
|
|
other = message->get_source(message);
|
|
dst_hash = generate_natd_hash(this, ike_sa_id, me);
|
|
src_hash = generate_natd_hash(this, ike_sa_id, other);
|
|
|
|
DBG3(DBG_IKE, "precalculated src_hash %B", &src_hash);
|
|
DBG3(DBG_IKE, "precalculated dst_hash %B", &dst_hash);
|
|
|
|
enumerator = message->create_payload_enumerator(message);
|
|
while (enumerator->enumerate(enumerator, &payload))
|
|
{
|
|
if (payload->get_type(payload) != NOTIFY)
|
|
{
|
|
continue;
|
|
}
|
|
notify = (notify_payload_t*)payload;
|
|
switch (notify->get_notify_type(notify))
|
|
{
|
|
case NAT_DETECTION_DESTINATION_IP:
|
|
{
|
|
this->dst_seen = TRUE;
|
|
hash = notify->get_notification_data(notify);
|
|
if (!this->dst_matched)
|
|
{
|
|
DBG3(DBG_IKE, "received dst_hash %B", &hash);
|
|
if (chunk_equals(hash, dst_hash))
|
|
{
|
|
this->dst_matched = TRUE;
|
|
}
|
|
}
|
|
/* RFC4555 says we should also compare against IKE_SA_INIT
|
|
* NATD payloads, but this does not work: We are running
|
|
* there at port 500, but use 4500 afterwards... */
|
|
if (message->get_exchange_type(message) == INFORMATIONAL &&
|
|
this->initiator && !this->dst_matched)
|
|
{
|
|
this->mapping_changed = this->ike_sa->has_mapping_changed(
|
|
this->ike_sa, hash);
|
|
}
|
|
break;
|
|
}
|
|
case NAT_DETECTION_SOURCE_IP:
|
|
{
|
|
this->src_seen = TRUE;
|
|
if (!this->src_matched)
|
|
{
|
|
hash = notify->get_notification_data(notify);
|
|
DBG3(DBG_IKE, "received src_hash %B", &hash);
|
|
if (chunk_equals(hash, src_hash))
|
|
{
|
|
this->src_matched = TRUE;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
enumerator->destroy(enumerator);
|
|
|
|
chunk_free(&src_hash);
|
|
chunk_free(&dst_hash);
|
|
|
|
if (this->src_seen && this->dst_seen)
|
|
{
|
|
this->ike_sa->enable_extension(this->ike_sa, EXT_NATT);
|
|
|
|
this->ike_sa->set_condition(this->ike_sa, COND_NAT_HERE,
|
|
!this->dst_matched);
|
|
this->ike_sa->set_condition(this->ike_sa, COND_NAT_THERE,
|
|
!this->src_matched);
|
|
config = this->ike_sa->get_ike_cfg(this->ike_sa);
|
|
if (this->dst_matched && this->src_matched &&
|
|
config->force_encap(config))
|
|
{
|
|
this->ike_sa->set_condition(this->ike_sa, COND_NAT_FAKE, TRUE);
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Implementation of task_t.process for initiator
|
|
*/
|
|
static status_t process_i(private_ike_natd_t *this, message_t *message)
|
|
{
|
|
process_payloads(this, message);
|
|
|
|
if (message->get_exchange_type(message) == IKE_SA_INIT)
|
|
{
|
|
peer_cfg_t *peer_cfg = this->ike_sa->get_peer_cfg(this->ike_sa);
|
|
if (this->ike_sa->has_condition(this->ike_sa, COND_NAT_ANY) ||
|
|
/* if peer supports NAT-T, we switch to port 4500 even
|
|
* if no NAT is detected. can't be done later (when we would know
|
|
* whether the peer supports MOBIKE) because there would be no
|
|
* exchange to actually do the switch (other than a forced DPD). */
|
|
(peer_cfg->use_mobike(peer_cfg) &&
|
|
this->ike_sa->supports_extension(this->ike_sa, EXT_NATT)))
|
|
{
|
|
this->ike_sa->float_ports(this->ike_sa);
|
|
}
|
|
}
|
|
|
|
return SUCCESS;
|
|
}
|
|
|
|
/**
|
|
* Implementation of task_t.process for initiator
|
|
*/
|
|
static status_t build_i(private_ike_natd_t *this, message_t *message)
|
|
{
|
|
notify_payload_t *notify;
|
|
enumerator_t *enumerator;
|
|
ike_cfg_t *ike_cfg;
|
|
host_t *host;
|
|
|
|
if (this->hasher == NULL)
|
|
{
|
|
DBG1(DBG_IKE, "unable to build NATD payloads, SHA1 not supported");
|
|
return NEED_MORE;
|
|
}
|
|
|
|
ike_cfg = this->ike_sa->get_ike_cfg(this->ike_sa);
|
|
|
|
/* destination is always set */
|
|
host = message->get_destination(message);
|
|
notify = build_natd_payload(this, NAT_DETECTION_DESTINATION_IP, host);
|
|
message->add_payload(message, (payload_t*)notify);
|
|
|
|
/* source may be any, we have 3 possibilities to get our source address:
|
|
* 1. It is defined in the config => use the one of the IKE_SA
|
|
* 2. We do a routing lookup in the kernel interface
|
|
* 3. Include all possbile addresses
|
|
*/
|
|
host = message->get_source(message);
|
|
if (!host->is_anyaddr(host))
|
|
{ /* 1. */
|
|
notify = build_natd_payload(this, NAT_DETECTION_SOURCE_IP, host);
|
|
message->add_payload(message, (payload_t*)notify);
|
|
}
|
|
else
|
|
{
|
|
host = hydra->kernel_interface->get_source_addr(hydra->kernel_interface,
|
|
this->ike_sa->get_other_host(this->ike_sa), NULL);
|
|
if (host)
|
|
{ /* 2. */
|
|
host->set_port(host, ike_cfg->get_my_port(ike_cfg));
|
|
notify = build_natd_payload(this, NAT_DETECTION_SOURCE_IP, host);
|
|
message->add_payload(message, (payload_t*)notify);
|
|
host->destroy(host);
|
|
}
|
|
else
|
|
{ /* 3. */
|
|
enumerator = hydra->kernel_interface->create_address_enumerator(
|
|
hydra->kernel_interface, FALSE, FALSE);
|
|
while (enumerator->enumerate(enumerator, (void**)&host))
|
|
{
|
|
/* apply port 500 to host, but work on a copy */
|
|
host = host->clone(host);
|
|
host->set_port(host, ike_cfg->get_my_port(ike_cfg));
|
|
notify = build_natd_payload(this, NAT_DETECTION_SOURCE_IP, host);
|
|
host->destroy(host);
|
|
message->add_payload(message, (payload_t*)notify);
|
|
}
|
|
enumerator->destroy(enumerator);
|
|
}
|
|
}
|
|
return NEED_MORE;
|
|
}
|
|
|
|
/**
|
|
* Implementation of task_t.build for responder
|
|
*/
|
|
static status_t build_r(private_ike_natd_t *this, message_t *message)
|
|
{
|
|
notify_payload_t *notify;
|
|
host_t *me, *other;
|
|
|
|
/* only add notifies on successful responses. */
|
|
if (message->get_exchange_type(message) == IKE_SA_INIT &&
|
|
message->get_payload(message, SECURITY_ASSOCIATION) == NULL)
|
|
{
|
|
return SUCCESS;
|
|
}
|
|
|
|
if (this->src_seen && this->dst_seen)
|
|
{
|
|
if (this->hasher == NULL)
|
|
{
|
|
DBG1(DBG_IKE, "unable to build NATD payloads, SHA1 not supported");
|
|
return SUCCESS;
|
|
}
|
|
|
|
/* initiator seems to support NAT detection, add response */
|
|
me = message->get_source(message);
|
|
notify = build_natd_payload(this, NAT_DETECTION_SOURCE_IP, me);
|
|
message->add_payload(message, (payload_t*)notify);
|
|
|
|
other = message->get_destination(message);
|
|
notify = build_natd_payload(this, NAT_DETECTION_DESTINATION_IP, other);
|
|
message->add_payload(message, (payload_t*)notify);
|
|
}
|
|
return SUCCESS;
|
|
}
|
|
|
|
/**
|
|
* Implementation of task_t.process for responder
|
|
*/
|
|
static status_t process_r(private_ike_natd_t *this, message_t *message)
|
|
{
|
|
process_payloads(this, message);
|
|
|
|
return NEED_MORE;
|
|
}
|
|
|
|
/**
|
|
* Implementation of task_t.get_type
|
|
*/
|
|
static task_type_t get_type(private_ike_natd_t *this)
|
|
{
|
|
return IKE_NATD;
|
|
}
|
|
|
|
/**
|
|
* Implementation of task_t.migrate
|
|
*/
|
|
static void migrate(private_ike_natd_t *this, ike_sa_t *ike_sa)
|
|
{
|
|
this->ike_sa = ike_sa;
|
|
this->src_seen = FALSE;
|
|
this->dst_seen = FALSE;
|
|
this->src_matched = FALSE;
|
|
this->dst_matched = FALSE;
|
|
this->mapping_changed = FALSE;
|
|
}
|
|
|
|
/**
|
|
* Implementation of ike_natd_t.has_mapping_changed
|
|
*/
|
|
static bool has_mapping_changed(private_ike_natd_t *this)
|
|
{
|
|
return this->mapping_changed;
|
|
}
|
|
|
|
/**
|
|
* Implementation of task_t.destroy
|
|
*/
|
|
static void destroy(private_ike_natd_t *this)
|
|
{
|
|
DESTROY_IF(this->hasher);
|
|
free(this);
|
|
}
|
|
|
|
/*
|
|
* Described in header.
|
|
*/
|
|
ike_natd_t *ike_natd_create(ike_sa_t *ike_sa, bool initiator)
|
|
{
|
|
private_ike_natd_t *this = malloc_thing(private_ike_natd_t);
|
|
|
|
this->public.task.get_type = (task_type_t(*)(task_t*))get_type;
|
|
this->public.task.migrate = (void(*)(task_t*,ike_sa_t*))migrate;
|
|
this->public.task.destroy = (void(*)(task_t*))destroy;
|
|
|
|
if (initiator)
|
|
{
|
|
this->public.task.build = (status_t(*)(task_t*,message_t*))build_i;
|
|
this->public.task.process = (status_t(*)(task_t*,message_t*))process_i;
|
|
}
|
|
else
|
|
{
|
|
this->public.task.build = (status_t(*)(task_t*,message_t*))build_r;
|
|
this->public.task.process = (status_t(*)(task_t*,message_t*))process_r;
|
|
}
|
|
|
|
this->public.has_mapping_changed = (bool(*)(ike_natd_t*))has_mapping_changed;
|
|
|
|
this->ike_sa = ike_sa;
|
|
this->initiator = initiator;
|
|
this->hasher = lib->crypto->create_hasher(lib->crypto, HASH_SHA1);
|
|
this->src_seen = FALSE;
|
|
this->dst_seen = FALSE;
|
|
this->src_matched = FALSE;
|
|
this->dst_matched = FALSE;
|
|
this->mapping_changed = FALSE;
|
|
|
|
return &this->public;
|
|
}
|