New upstream version.

6 files changed, 1644 insertions, 0 deletions

diff --git a/src/libhydra/kernel/kernel_interface.c b/src/libhydra/kernel/kernel_interface.c
new file mode 100644
index 000000000..3e6d46205
--- /dev/null
+++ b/src/libhydra/kernel/kernel_interface.c
@@ -0,0 +1,522 @@
+/*
+ * Copyright (C) 2008-2010 Tobias Brunner
+ * Hochschule fuer Technik Rapperswil
+ * Copyright (C) 2010 Martin Willi
+ * Copyright (C) 2010 revosec AG
+ *
+ * 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 "kernel_interface.h"
+
+#include <debug.h>
+#include <threading/mutex.h>
+#include <utils/linked_list.h>
+
+typedef struct private_kernel_interface_t private_kernel_interface_t;
+
+/**
+ * Private data of a kernel_interface_t object.
+ */
+struct private_kernel_interface_t {
+
+	/**
+	 * Public part of kernel_interface_t object.
+	 */
+	kernel_interface_t public;
+
+	/**
+	 * ipsec interface
+	 */
+	kernel_ipsec_t *ipsec;
+
+	/**
+	 * network interface
+	 */
+	kernel_net_t *net;
+
+	/**
+	 * mutex for listeners
+	 */
+	mutex_t *mutex;
+
+	/**
+	 * list of registered listeners
+	 */
+	linked_list_t *listeners;
+};
+
+METHOD(kernel_interface_t, get_spi, status_t,
+	private_kernel_interface_t *this, host_t *src, host_t *dst,
+	u_int8_t protocol, u_int32_t reqid, u_int32_t *spi)
+{
+	if (!this->ipsec)
+	{
+		return NOT_SUPPORTED;
+	}
+	return this->ipsec->get_spi(this->ipsec, src, dst, protocol, reqid, spi);
+}
+
+METHOD(kernel_interface_t, get_cpi, status_t,
+	private_kernel_interface_t *this, host_t *src, host_t *dst,
+	u_int32_t reqid, u_int16_t *cpi)
+{
+	if (!this->ipsec)
+	{
+		return NOT_SUPPORTED;
+	}
+	return this->ipsec->get_cpi(this->ipsec, src, dst, reqid, cpi);
+}
+
+METHOD(kernel_interface_t, add_sa, status_t,
+	private_kernel_interface_t *this, host_t *src, host_t *dst,
+	u_int32_t spi, u_int8_t protocol, u_int32_t reqid,
+	mark_t mark, lifetime_cfg_t *lifetime, u_int16_t enc_alg, chunk_t enc_key,
+	u_int16_t int_alg, chunk_t int_key,	ipsec_mode_t mode, u_int16_t ipcomp,
+	u_int16_t cpi, bool encap, bool inbound, traffic_selector_t *src_ts,
+	traffic_selector_t *dst_ts)
+{
+	if (!this->ipsec)
+	{
+		return NOT_SUPPORTED;
+	}
+	return this->ipsec->add_sa(this->ipsec, src, dst, spi, protocol, reqid,
+			mark, lifetime, enc_alg, enc_key, int_alg, int_key,	mode, ipcomp,
+			cpi, encap, inbound, src_ts, dst_ts);
+}
+
+METHOD(kernel_interface_t, update_sa, status_t,
+	private_kernel_interface_t *this, u_int32_t spi, u_int8_t protocol,
+	u_int16_t cpi, host_t *src, host_t *dst, host_t *new_src, host_t *new_dst,
+	bool encap, bool new_encap, mark_t mark)
+{
+	if (!this->ipsec)
+	{
+		return NOT_SUPPORTED;
+	}
+	return this->ipsec->update_sa(this->ipsec, spi, protocol, cpi, src, dst,
+								  new_src, new_dst, encap, new_encap, mark);
+}
+
+METHOD(kernel_interface_t, query_sa, status_t,
+	private_kernel_interface_t *this, host_t *src, host_t *dst,
+	u_int32_t spi, u_int8_t protocol, mark_t mark, u_int64_t *bytes)
+{
+	if (!this->ipsec)
+	{
+		return NOT_SUPPORTED;
+	}
+	return this->ipsec->query_sa(this->ipsec, src, dst, spi, protocol, mark, bytes);
+}
+
+METHOD(kernel_interface_t, del_sa, status_t,
+	private_kernel_interface_t *this, host_t *src, host_t *dst, u_int32_t spi,
+	u_int8_t protocol, u_int16_t cpi, mark_t mark)
+{
+	if (!this->ipsec)
+	{
+		return NOT_SUPPORTED;
+	}
+	return this->ipsec->del_sa(this->ipsec, src, dst, spi, protocol, cpi, mark);
+}
+
+METHOD(kernel_interface_t, add_policy, status_t,
+	private_kernel_interface_t *this, host_t *src, host_t *dst,
+	traffic_selector_t *src_ts, traffic_selector_t *dst_ts,
+	policy_dir_t direction, policy_type_t type, ipsec_sa_cfg_t *sa,
+	mark_t mark, bool routed)
+{
+	if (!this->ipsec)
+	{
+		return NOT_SUPPORTED;
+	}
+	return this->ipsec->add_policy(this->ipsec, src, dst, src_ts, dst_ts,
+								   direction, type, sa, mark, routed);
+}
+
+METHOD(kernel_interface_t, query_policy, status_t,
+	private_kernel_interface_t *this, traffic_selector_t *src_ts,
+	traffic_selector_t *dst_ts, policy_dir_t direction, mark_t mark,
+	u_int32_t *use_time)
+{
+	if (!this->ipsec)
+	{
+		return NOT_SUPPORTED;
+	}
+	return this->ipsec->query_policy(this->ipsec, src_ts, dst_ts,
+									 direction, mark, use_time);
+}
+
+METHOD(kernel_interface_t, del_policy, status_t,
+	private_kernel_interface_t *this, traffic_selector_t *src_ts,
+	traffic_selector_t *dst_ts, policy_dir_t direction, mark_t mark,
+	bool unrouted)
+{
+	if (!this->ipsec)
+	{
+		return NOT_SUPPORTED;
+	}
+	return this->ipsec->del_policy(this->ipsec, src_ts, dst_ts,
+								   direction, mark, unrouted);
+}
+
+METHOD(kernel_interface_t, get_source_addr, host_t*,
+	private_kernel_interface_t *this, host_t *dest, host_t *src)
+{
+	if (!this->net)
+	{
+		return NULL;
+	}
+	return this->net->get_source_addr(this->net, dest, src);
+}
+
+METHOD(kernel_interface_t, get_nexthop, host_t*,
+	private_kernel_interface_t *this, host_t *dest)
+{
+	if (!this->net)
+	{
+		return NULL;
+	}
+	return this->net->get_nexthop(this->net, dest);
+}
+
+METHOD(kernel_interface_t, get_interface, char*,
+	private_kernel_interface_t *this, host_t *host)
+{
+	if (!this->net)
+	{
+		return NULL;
+	}
+	return this->net->get_interface(this->net, host);
+}
+
+METHOD(kernel_interface_t, create_address_enumerator, enumerator_t*,
+	private_kernel_interface_t *this, bool include_down_ifaces,
+	bool include_virtual_ips)
+{
+	if (!this->net)
+	{
+		return enumerator_create_empty();
+	}
+	return this->net->create_address_enumerator(this->net, include_down_ifaces,
+												include_virtual_ips);
+}
+
+METHOD(kernel_interface_t, add_ip, status_t,
+	private_kernel_interface_t *this, host_t *virtual_ip, host_t *iface_ip)
+{
+	if (!this->net)
+	{
+		return NOT_SUPPORTED;
+	}
+	return this->net->add_ip(this->net, virtual_ip, iface_ip);
+}
+
+METHOD(kernel_interface_t, del_ip, status_t,
+	private_kernel_interface_t *this, host_t *virtual_ip)
+{
+	if (!this->net)
+	{
+		return NOT_SUPPORTED;
+	}
+	return this->net->del_ip(this->net, virtual_ip);
+}
+
+METHOD(kernel_interface_t, add_route, status_t,
+	private_kernel_interface_t *this, chunk_t dst_net,
+	u_int8_t prefixlen, host_t *gateway, host_t *src_ip, char *if_name)
+{
+	if (!this->net)
+	{
+		return NOT_SUPPORTED;
+	}
+	return this->net->add_route(this->net, dst_net, prefixlen, gateway,
+								src_ip, if_name);
+}
+
+METHOD(kernel_interface_t, del_route, status_t,
+	private_kernel_interface_t *this, chunk_t dst_net,
+	u_int8_t prefixlen, host_t *gateway, host_t *src_ip, char *if_name)
+{
+	if (!this->net)
+	{
+		return NOT_SUPPORTED;
+	}
+	return this->net->del_route(this->net, dst_net, prefixlen, gateway,
+								src_ip, if_name);
+}
+
+METHOD(kernel_interface_t, bypass_socket, bool,
+	private_kernel_interface_t *this, int fd, int family)
+{
+	if (!this->ipsec)
+	{
+		return FALSE;
+	}
+	return this->ipsec->bypass_socket(this->ipsec, fd, family);
+}
+
+METHOD(kernel_interface_t, get_address_by_ts, status_t,
+	private_kernel_interface_t *this, traffic_selector_t *ts, host_t **ip)
+{
+	enumerator_t *addrs;
+	host_t *host;
+	int family;
+	bool found = FALSE;
+
+	DBG2(DBG_KNL, "getting a local address in traffic selector %R", ts);
+
+	/* if we have a family which includes localhost, we do not
+	 * search for an IP, we use the default */
+	family = ts->get_type(ts) == TS_IPV4_ADDR_RANGE ? AF_INET : AF_INET6;
+
+	if (family == AF_INET)
+	{
+		host = host_create_from_string("127.0.0.1", 0);
+	}
+	else
+	{
+		host = host_create_from_string("::1", 0);
+	}
+
+	if (ts->includes(ts, host))
+	{
+		*ip = host_create_any(family);
+		host->destroy(host);
+		DBG2(DBG_KNL, "using host %H", *ip);
+		return SUCCESS;
+	}
+	host->destroy(host);
+
+	addrs = create_address_enumerator(this, TRUE, TRUE);
+	while (addrs->enumerate(addrs, (void**)&host))
+	{
+		if (ts->includes(ts, host))
+		{
+			found = TRUE;
+			*ip = host->clone(host);
+			break;
+		}
+	}
+	addrs->destroy(addrs);
+
+	if (!found)
+	{
+		DBG1(DBG_KNL, "no local address found in traffic selector %R", ts);
+		return FAILED;
+	}
+
+	DBG2(DBG_KNL, "using host %H", *ip);
+	return SUCCESS;
+}
+
+
+METHOD(kernel_interface_t, add_ipsec_interface, void,
+	private_kernel_interface_t *this, kernel_ipsec_constructor_t constructor)
+{
+	if (!this->ipsec)
+	{
+		this->ipsec = constructor();
+	}
+}
+
+METHOD(kernel_interface_t, remove_ipsec_interface, void,
+	private_kernel_interface_t *this, kernel_ipsec_constructor_t constructor)
+{
+	/* TODO: replace if interface currently in use */
+}
+
+METHOD(kernel_interface_t, add_net_interface, void,
+	private_kernel_interface_t *this, kernel_net_constructor_t constructor)
+{
+	if (!this->net)
+	{
+		this->net = constructor();
+	}
+}
+
+METHOD(kernel_interface_t, remove_net_interface, void,
+	private_kernel_interface_t *this, kernel_net_constructor_t constructor)
+{
+	/* TODO: replace if interface currently in use */
+}
+
+METHOD(kernel_interface_t, add_listener, void,
+	private_kernel_interface_t *this, kernel_listener_t *listener)
+{
+	this->mutex->lock(this->mutex);
+	this->listeners->insert_last(this->listeners, listener);
+	this->mutex->unlock(this->mutex);
+}
+
+METHOD(kernel_interface_t, remove_listener, void,
+	private_kernel_interface_t *this, kernel_listener_t *listener)
+{
+	this->mutex->lock(this->mutex);
+	this->listeners->remove(this->listeners, listener, NULL);
+	this->mutex->unlock(this->mutex);
+}
+
+METHOD(kernel_interface_t, acquire, void,
+	private_kernel_interface_t *this, u_int32_t reqid,
+	traffic_selector_t *src_ts, traffic_selector_t *dst_ts)
+{
+	kernel_listener_t *listener;
+	enumerator_t *enumerator;
+	this->mutex->lock(this->mutex);
+	enumerator = this->listeners->create_enumerator(this->listeners);
+	while (enumerator->enumerate(enumerator, &listener))
+	{
+		if (listener->acquire &&
+			!listener->acquire(listener, reqid, src_ts, dst_ts))
+		{
+			this->listeners->remove_at(this->listeners, enumerator);
+		}
+	}
+	enumerator->destroy(enumerator);
+	this->mutex->unlock(this->mutex);
+}
+
+METHOD(kernel_interface_t, expire, void,
+	private_kernel_interface_t *this, u_int32_t reqid, u_int8_t protocol,
+	u_int32_t spi, bool hard)
+{
+	kernel_listener_t *listener;
+	enumerator_t *enumerator;
+	this->mutex->lock(this->mutex);
+	enumerator = this->listeners->create_enumerator(this->listeners);
+	while (enumerator->enumerate(enumerator, &listener))
+	{
+		if (listener->expire &&
+			!listener->expire(listener, reqid, protocol, spi, hard))
+		{
+			this->listeners->remove_at(this->listeners, enumerator);
+		}
+	}
+	enumerator->destroy(enumerator);
+	this->mutex->unlock(this->mutex);
+}
+
+METHOD(kernel_interface_t, mapping, void,
+	private_kernel_interface_t *this, u_int32_t reqid, u_int32_t spi,
+	host_t *remote)
+{
+	kernel_listener_t *listener;
+	enumerator_t *enumerator;
+	this->mutex->lock(this->mutex);
+	enumerator = this->listeners->create_enumerator(this->listeners);
+	while (enumerator->enumerate(enumerator, &listener))
+	{
+		if (listener->mapping &&
+			!listener->mapping(listener, reqid, spi, remote))
+		{
+			this->listeners->remove_at(this->listeners, enumerator);
+		}
+	}
+	enumerator->destroy(enumerator);
+	this->mutex->unlock(this->mutex);
+}
+
+METHOD(kernel_interface_t, migrate, void,
+	private_kernel_interface_t *this, u_int32_t reqid,
+	traffic_selector_t *src_ts, traffic_selector_t *dst_ts,
+	policy_dir_t direction, host_t *local, host_t *remote)
+{
+	kernel_listener_t *listener;
+	enumerator_t *enumerator;
+	this->mutex->lock(this->mutex);
+	enumerator = this->listeners->create_enumerator(this->listeners);
+	while (enumerator->enumerate(enumerator, &listener))
+	{
+		if (listener->migrate &&
+			!listener->migrate(listener, reqid, src_ts, dst_ts, direction,
+							   local, remote))
+		{
+			this->listeners->remove_at(this->listeners, enumerator);
+		}
+	}
+	enumerator->destroy(enumerator);
+	this->mutex->unlock(this->mutex);
+}
+
+static bool call_roam(kernel_listener_t *listener, bool *roam)
+{
+	return listener->roam && !listener->roam(listener, *roam);
+}
+
+METHOD(kernel_interface_t, roam, void,
+	private_kernel_interface_t *this, bool address)
+{
+	this->mutex->lock(this->mutex);
+	this->listeners->remove(this->listeners, &address, (void*)call_roam);
+	this->mutex->unlock(this->mutex);
+}
+
+METHOD(kernel_interface_t, destroy, void,
+	private_kernel_interface_t *this)
+{
+	DESTROY_IF(this->ipsec);
+	DESTROY_IF(this->net);
+	this->mutex->destroy(this->mutex);
+	this->listeners->destroy(this->listeners);
+	free(this);
+}
+
+/*
+ * Described in header-file
+ */
+kernel_interface_t *kernel_interface_create()
+{
+	private_kernel_interface_t *this;
+
+	INIT(this,
+		.public = {
+			.get_spi = _get_spi,
+			.get_cpi = _get_cpi,
+			.add_sa = _add_sa,
+			.update_sa = _update_sa,
+			.query_sa = _query_sa,
+			.del_sa = _del_sa,
+			.add_policy = _add_policy,
+			.query_policy = _query_policy,
+			.del_policy = _del_policy,
+			.get_source_addr = _get_source_addr,
+			.get_nexthop = _get_nexthop,
+			.get_interface = _get_interface,
+			.create_address_enumerator = _create_address_enumerator,
+			.add_ip = _add_ip,
+			.del_ip = _del_ip,
+			.add_route = _add_route,
+			.del_route = _del_route,
+			.bypass_socket = _bypass_socket,
+
+			.get_address_by_ts = _get_address_by_ts,
+			.add_ipsec_interface = _add_ipsec_interface,
+			.remove_ipsec_interface = _remove_ipsec_interface,
+			.add_net_interface = _add_net_interface,
+			.remove_net_interface = _remove_net_interface,
+
+			.add_listener = _add_listener,
+			.remove_listener = _remove_listener,
+			.acquire = _acquire,
+			.expire = _expire,
+			.mapping = _mapping,
+			.migrate = _migrate,
+			.roam = _roam,
+			.destroy = _destroy,
+		},
+		.mutex = mutex_create(MUTEX_TYPE_DEFAULT),
+		.listeners = linked_list_create(),
+	);
+
+	return &this->public;
+}
+
diff --git a/src/libhydra/kernel/kernel_interface.h b/src/libhydra/kernel/kernel_interface.h
new file mode 100644
index 000000000..8b0c7a296
--- /dev/null
+++ b/src/libhydra/kernel/kernel_interface.h
@@ -0,0 +1,476 @@
+/*
+ * Copyright (C) 2006-2010 Tobias Brunner
+ * Copyright (C) 2006 Daniel Roethlisberger
+ * Copyright (C) 2005-2006 Martin Willi
+ * Copyright (C) 2005 Jan Hutter
+ * 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.
+ */
+
+/**
+ * @defgroup kernel_interface kernel_interface
+ * @{ @ingroup hkernel
+ */
+
+#ifndef KERNEL_INTERFACE_H_
+#define KERNEL_INTERFACE_H_
+
+typedef struct kernel_interface_t kernel_interface_t;
+
+#include <utils/host.h>
+#include <crypto/prf_plus.h>
+
+#include <kernel/kernel_listener.h>
+#include <kernel/kernel_ipsec.h>
+#include <kernel/kernel_net.h>
+
+/**
+ * Constructor function for ipsec kernel interface
+ */
+typedef kernel_ipsec_t* (*kernel_ipsec_constructor_t)(void);
+
+/**
+ * Constructor function for network kernel interface
+ */
+typedef kernel_net_t* (*kernel_net_constructor_t)(void);
+
+/**
+ * Manager and wrapper for different kernel interfaces.
+ *
+ * The kernel interface handles the communication with the kernel
+ * for SA and policy management and interface and IP address management.
+ */
+struct kernel_interface_t {
+
+	/**
+	 * Get a SPI from the kernel.
+	 *
+	 * @param src		source address of SA
+	 * @param dst		destination address of SA
+	 * @param protocol	protocol for SA (ESP/AH)
+	 * @param reqid		unique ID for this SA
+	 * @param spi		allocated spi
+	 * @return				SUCCESS if operation completed
+	 */
+	status_t (*get_spi)(kernel_interface_t *this, host_t *src, host_t *dst,
+						u_int8_t protocol, u_int32_t reqid, u_int32_t *spi);
+
+	/**
+	 * Get a Compression Parameter Index (CPI) from the kernel.
+	 *
+	 * @param src		source address of SA
+	 * @param dst		destination address of SA
+	 * @param reqid		unique ID for the corresponding SA
+	 * @param cpi		allocated cpi
+	 * @return				SUCCESS if operation completed
+	 */
+	status_t (*get_cpi)(kernel_interface_t *this, host_t *src, host_t *dst,
+						u_int32_t reqid, u_int16_t *cpi);
+
+	/**
+	 * Add an SA to the SAD.
+	 *
+	 * add_sa() may update an already allocated
+	 * SPI (via get_spi). In this case, the replace
+	 * flag must be set.
+	 * This function does install a single SA for a
+	 * single protocol in one direction.
+	 *
+	 * @param src			source address for this SA
+	 * @param dst			destination address for this SA
+	 * @param spi			SPI allocated by us or remote peer
+	 * @param protocol		protocol for this SA (ESP/AH)
+	 * @param reqid			unique ID for this SA
+	 * @param mark			optional mark for this SA
+	 * @param lifetime		lifetime_cfg_t for this SA
+	 * @param enc_alg		Algorithm to use for encryption (ESP only)
+	 * @param enc_key		key to use for encryption
+	 * @param int_alg		Algorithm to use for integrity protection
+	 * @param int_key		key to use for integrity protection
+	 * @param mode			mode of the SA (tunnel, transport)
+	 * @param ipcomp		IPComp transform to use
+	 * @param cpi			CPI for IPComp
+	 * @param encap			enable UDP encapsulation for NAT traversal
+	 * @param inbound		TRUE if this is an inbound SA
+	 * @param src_ts		traffic selector with BEET source address
+	 * @param dst_ts		traffic selector with BEET destination address
+	 * @return				SUCCESS if operation completed
+	 */
+	status_t (*add_sa) (kernel_interface_t *this,
+						host_t *src, host_t *dst, u_int32_t spi,
+						u_int8_t protocol, u_int32_t reqid, mark_t mark,
+						lifetime_cfg_t *lifetime,
+						u_int16_t enc_alg, chunk_t enc_key,
+						u_int16_t int_alg, chunk_t int_key,
+						ipsec_mode_t mode, u_int16_t ipcomp, u_int16_t cpi,
+						bool encap, bool inbound,
+						traffic_selector_t *src_ts, traffic_selector_t *dst_ts);
+
+	/**
+	 * Update the hosts on an installed SA.
+	 *
+	 * We cannot directly update the destination address as the kernel
+	 * requires the spi, the protocol AND the destination address (and family)
+	 * to identify SAs. Therefore if the destination address changed we
+	 * create a new SA and delete the old one.
+	 *
+	 * @param spi			SPI of the SA
+	 * @param protocol		protocol for this SA (ESP/AH)
+	 * @param cpi			CPI for IPComp, 0 if no IPComp is used
+	 * @param src			current source address
+	 * @param dst			current destination address
+	 * @param new_src		new source address
+	 * @param new_dst		new destination address
+	 * @param encap			current use of UDP encapsulation
+	 * @param new_encap		new use of UDP encapsulation
+	 * @param mark			optional mark for this SA
+	 * @return				SUCCESS if operation completed, NOT_SUPPORTED if
+	 *					  the kernel interface can't update the SA
+	 */
+	status_t (*update_sa)(kernel_interface_t *this,
+						  u_int32_t spi, u_int8_t protocol, u_int16_t cpi,
+						  host_t *src, host_t *dst,
+						  host_t *new_src, host_t *new_dst,
+						  bool encap, bool new_encap, mark_t mark);
+
+	/**
+	 * Query the number of bytes processed by an SA from the SAD.
+	 *
+	 * @param src			source address for this SA
+	 * @param dst			destination address for this SA
+	 * @param spi			SPI allocated by us or remote peer
+	 * @param protocol		protocol for this SA (ESP/AH)
+	 * @param mark			optional mark for this SA
+	 * @param[out] bytes	the number of bytes processed by SA
+	 * @return				SUCCESS if operation completed
+	 */
+	status_t (*query_sa) (kernel_interface_t *this, host_t *src, host_t *dst,
+						  u_int32_t spi, u_int8_t protocol, mark_t mark,
+						  u_int64_t *bytes);
+
+	/**
+	 * Delete a previously installed SA from the SAD.
+	 *
+	 * @param src			source address for this SA
+	 * @param dst			destination address for this SA
+	 * @param spi			SPI allocated by us or remote peer
+	 * @param protocol		protocol for this SA (ESP/AH)
+	 * @param cpi			CPI for IPComp or 0
+	 * @param mark			optional mark for this SA
+	 * @return				SUCCESS if operation completed
+	 */
+	status_t (*del_sa) (kernel_interface_t *this, host_t *src, host_t *dst,
+						u_int32_t spi, u_int8_t protocol, u_int16_t cpi,
+						mark_t mark);
+
+	/**
+	 * Add a policy to the SPD.
+	 *
+	 * A policy is always associated to an SA. Traffic which matches a
+	 * policy is handled by the SA with the same reqid.
+	 *
+	 * @param src			source address of SA
+	 * @param dst			dest address of SA
+	 * @param src_ts		traffic selector to match traffic source
+	 * @param dst_ts		traffic selector to match traffic dest
+	 * @param direction		direction of traffic, POLICY_(IN|OUT|FWD)
+	 * @param type			type of policy, POLICY_(IPSEC|PASS|DROP)
+	 * @param sa			details about the SA(s) tied to this policy
+	 * @param mark			mark for this policy
+	 * @param routed		TRUE, if this policy is routed in the kernel
+	 * @return				SUCCESS if operation completed
+	 */
+	status_t (*add_policy) (kernel_interface_t *this,
+							host_t *src, host_t *dst,
+							traffic_selector_t *src_ts,
+							traffic_selector_t *dst_ts,
+							policy_dir_t direction, policy_type_t type,
+							ipsec_sa_cfg_t *sa, mark_t mark, bool routed);
+
+	/**
+	 * Query the use time of a policy.
+	 *
+	 * The use time of a policy is the time the policy was used
+	 * for the last time.
+	 *
+	 * @param src_ts		traffic selector to match traffic source
+	 * @param dst_ts		traffic selector to match traffic dest
+	 * @param direction		direction of traffic, POLICY_(IN|OUT|FWD)
+	 * @param mark			optional mark
+	 * @param[out] use_time	the time of this SA's last use
+	 * @return				SUCCESS if operation completed
+	 */
+	status_t (*query_policy) (kernel_interface_t *this,
+							  traffic_selector_t *src_ts,
+							  traffic_selector_t *dst_ts,
+							  policy_dir_t direction, mark_t mark,
+							  u_int32_t *use_time);
+
+	/**
+	 * Remove a policy from the SPD.
+	 *
+	 * The kernel interface implements reference counting for policies.
+	 * If the same policy is installed multiple times (in the case of rekeying),
+	 * the reference counter is increased. del_policy() decreases the ref counter
+	 * and removes the policy only when no more references are available.
+	 *
+	 * @param src_ts		traffic selector to match traffic source
+	 * @param dst_ts		traffic selector to match traffic dest
+	 * @param direction		direction of traffic, POLICY_(IN|OUT|FWD)
+	 * @param mark			optional mark
+	 * @param unrouted		TRUE, if this policy is unrouted from the kernel
+	 * @return				SUCCESS if operation completed
+	 */
+	status_t (*del_policy) (kernel_interface_t *this,
+							traffic_selector_t *src_ts,
+							traffic_selector_t *dst_ts,
+							policy_dir_t direction, mark_t mark,
+							bool unrouted);
+
+	/**
+	 * Get our outgoing source address for a destination.
+	 *
+	 * Does a route lookup to get the source address used to reach dest.
+	 * The returned host is allocated and must be destroyed.
+	 * An optional src address can be used to check if a route is available
+	 * for given source to dest.
+	 *
+	 * @param dest			target destination address
+	 * @param src			source address to check, or NULL
+	 * @return				outgoing source address, NULL if unreachable
+	 */
+	host_t* (*get_source_addr)(kernel_interface_t *this,
+							   host_t *dest, host_t *src);
+
+	/**
+	 * Get the next hop for a destination.
+	 *
+	 * Does a route lookup to get the next hop used to reach dest.
+	 * The returned host is allocated and must be destroyed.
+	 *
+	 * @param dest			target destination address
+	 * @return				next hop address, NULL if unreachable
+	 */
+	host_t* (*get_nexthop)(kernel_interface_t *this, host_t *dest);
+
+	/**
+	 * Get the interface name of a local address.
+	 *
+	 * @param host			address to get interface name from
+	 * @return				allocated interface name, or NULL if not found
+	 */
+	char* (*get_interface) (kernel_interface_t *this, host_t *host);
+
+	/**
+	 * Creates an enumerator over all local addresses.
+	 *
+	 * This function blocks an internal cached address list until the
+	 * enumerator gets destroyed.
+	 * The hosts are read-only, do not modify of free.
+	 *
+	 * @param include_down_ifaces	TRUE to enumerate addresses from down interfaces
+	 * @param include_virtual_ips	TRUE to enumerate virtual ip addresses
+	 * @return						enumerator over host_t's
+	 */
+	enumerator_t *(*create_address_enumerator) (kernel_interface_t *this,
+						bool include_down_ifaces, bool include_virtual_ips);
+
+	/**
+	 * Add a virtual IP to an interface.
+	 *
+	 * Virtual IPs are attached to an interface. If an IP is added multiple
+	 * times, the IP is refcounted and not removed until del_ip() was called
+	 * as many times as add_ip().
+	 * The virtual IP is attached to the interface where the iface_ip is found.
+	 *
+	 * @param virtual_ip	virtual ip address to assign
+	 * @param iface_ip		IP of an interface to attach virtual IP
+	 * @return				SUCCESS if operation completed
+	 */
+	status_t (*add_ip) (kernel_interface_t *this, host_t *virtual_ip,
+						host_t *iface_ip);
+
+	/**
+	 * Remove a virtual IP from an interface.
+	 *
+	 * The kernel interface uses refcounting, see add_ip().
+	 *
+	 * @param virtual_ip	virtual ip address to assign
+	 * @return				SUCCESS if operation completed
+	 */
+	status_t (*del_ip) (kernel_interface_t *this, host_t *virtual_ip);
+
+	/**
+	 * Add a route.
+	 *
+	 * @param dst_net		destination net
+	 * @param prefixlen		destination net prefix length
+	 * @param gateway		gateway for this route
+	 * @param src_ip		sourc ip of the route
+	 * @param if_name		name of the interface the route is bound to
+	 * @return				SUCCESS if operation completed
+	 *						ALREADY_DONE if the route already exists
+	 */
+	status_t (*add_route) (kernel_interface_t *this, chunk_t dst_net,
+						   u_int8_t prefixlen, host_t *gateway, host_t *src_ip,
+						   char *if_name);
+
+	/**
+	 * Delete a route.
+	 *
+	 * @param dst_net		destination net
+	 * @param prefixlen		destination net prefix length
+	 * @param gateway		gateway for this route
+	 * @param src_ip		sourc ip of the route
+	 * @param if_name		name of the interface the route is bound to
+	 * @return				SUCCESS if operation completed
+	 */
+	status_t (*del_route) (kernel_interface_t *this, chunk_t dst_net,
+						   u_int8_t prefixlen, host_t *gateway, host_t *src_ip,
+						   char *if_name);
+
+	/**
+	 * Set up a bypass policy for a given socket.
+	 *
+	 * @param fd			socket file descriptor to setup policy for
+	 * @param family		protocol family of the socket
+	 * @return				TRUE of policy set up successfully
+	 */
+	bool (*bypass_socket)(kernel_interface_t *this, int fd, int family);
+
+	/**
+	 * manager methods
+	 */
+
+	/**
+	 * Tries to find an ip address of a local interface that is included in the
+	 * supplied traffic selector.
+	 *
+	 * @param ts			traffic selector
+	 * @param ip			returned ip (has to be destroyed)
+	 * @return				SUCCESS if address found
+	 */
+	status_t (*get_address_by_ts)(kernel_interface_t *this,
+								  traffic_selector_t *ts, host_t **ip);
+
+	/**
+	 * Register an ipsec kernel interface constructor on the manager.
+	 *
+	 * @param create			constructor to register
+	 */
+	void (*add_ipsec_interface)(kernel_interface_t *this,
+								kernel_ipsec_constructor_t create);
+
+	/**
+	 * Unregister an ipsec kernel interface constructor.
+	 *
+	 * @param create			constructor to unregister
+	 */
+	void (*remove_ipsec_interface)(kernel_interface_t *this,
+								   kernel_ipsec_constructor_t create);
+
+	/**
+	 * Register a network kernel interface constructor on the manager.
+	 *
+	 * @param create			constructor to register
+	 */
+	void (*add_net_interface)(kernel_interface_t *this,
+							  kernel_net_constructor_t create);
+
+	/**
+	 * Unregister a network kernel interface constructor.
+	 *
+	 * @param create			constructor to unregister
+	 */
+	void (*remove_net_interface)(kernel_interface_t *this,
+								 kernel_net_constructor_t create);
+
+	/**
+	 * Add a listener to the kernel interface.
+	 *
+	 * @param listener			listener to add
+	 */
+	void (*add_listener)(kernel_interface_t *this,
+						 kernel_listener_t *listener);
+
+	/**
+	 * Remove a listener from the kernel interface.
+	 *
+	 * @param listener			listener to remove
+	 */
+	void (*remove_listener)(kernel_interface_t *this,
+							kernel_listener_t *listener);
+
+	/**
+	 * Raise an acquire event.
+	 *
+	 * @param reqid			reqid of the policy to acquire
+	 * @param src_ts		source traffic selector
+	 * @param dst_ts		destination traffic selector
+	 */
+	void (*acquire)(kernel_interface_t *this, u_int32_t reqid,
+					traffic_selector_t *src_ts, traffic_selector_t *dst_ts);
+
+	/**
+	 * Raise an expire event.
+	 *
+	 * @param reqid			reqid of the expired SA
+	 * @param protocol		protocol of the expired SA
+	 * @param spi			spi of the expired SA
+	 * @param hard			TRUE if it is a hard expire, FALSE otherwise
+	 */
+	void (*expire)(kernel_interface_t *this, u_int32_t reqid,
+				   u_int8_t protocol, u_int32_t spi, bool hard);
+
+	/**
+	 * Raise a mapping event.
+	 *
+	 * @param reqid			reqid of the SA
+	 * @param spi			spi of the SA
+	 * @param remote		new remote host
+	 */
+	void (*mapping)(kernel_interface_t *this, u_int32_t reqid, u_int32_t spi,
+					host_t *remote);
+
+	/**
+	 * Raise a migrate event.
+	 *
+	 * @param reqid			reqid of the policy
+	 * @param src_ts		source traffic selector
+	 * @param dst_ts		destination traffic selector
+	 * @param direction		direction of the policy (in|out)
+	 * @param local			local host address to be used in the IKE_SA
+	 * @param remote		remote host address to be used in the IKE_SA
+	 */
+	void (*migrate)(kernel_interface_t *this, u_int32_t reqid,
+					traffic_selector_t *src_ts, traffic_selector_t *dst_ts,
+					policy_dir_t direction, host_t *local, host_t *remote);
+
+	/**
+	 * Raise a roam event.
+	 *
+	 * @param address		TRUE if address list, FALSE if routing changed
+	 */
+	void (*roam)(kernel_interface_t *this, bool address);
+
+	/**
+	 * Destroys a kernel_interface_manager_t object.
+	 */
+	void (*destroy) (kernel_interface_t *this);
+};
+
+/**
+ * Creates an object of type kernel_interface_t.
+ */
+kernel_interface_t *kernel_interface_create(void);
+
+#endif /** KERNEL_INTERFACE_H_ @}*/
diff --git a/src/libhydra/kernel/kernel_ipsec.c b/src/libhydra/kernel/kernel_ipsec.c
new file mode 100644
index 000000000..383685426
--- /dev/null
+++ b/src/libhydra/kernel/kernel_ipsec.c
@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2008 Tobias Brunner
+ * 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 "kernel_ipsec.h"
+
+ENUM(ipsec_mode_names, MODE_TRANSPORT, MODE_BEET,
+	"TRANSPORT",
+	"TUNNEL",
+	"BEET",
+);
+
+ENUM(policy_dir_names, POLICY_IN, POLICY_FWD,
+	"in",
+	"out",
+	"fwd"
+);
+
+ENUM(ipcomp_transform_names, IPCOMP_NONE, IPCOMP_LZJH,
+	"IPCOMP_NONE",
+	"IPCOMP_OUI",
+	"IPCOMP_DEFLATE",
+	"IPCOMP_LZS",
+	"IPCOMP_LZJH"
+);
+
diff --git a/src/libhydra/kernel/kernel_ipsec.h b/src/libhydra/kernel/kernel_ipsec.h
new file mode 100644
index 000000000..49d9cc07a
--- /dev/null
+++ b/src/libhydra/kernel/kernel_ipsec.h
@@ -0,0 +1,368 @@
+/*
+ * Copyright (C) 2006-2010 Tobias Brunner
+ * Copyright (C) 2006 Daniel Roethlisberger
+ * Copyright (C) 2005-2006 Martin Willi
+ * Copyright (C) 2005 Jan Hutter
+ * 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.
+ */
+
+/**
+ * @defgroup kernel_ipsec kernel_ipsec
+ * @{ @ingroup hkernel
+ */
+
+#ifndef KERNEL_IPSEC_H_
+#define KERNEL_IPSEC_H_
+
+typedef enum ipsec_mode_t ipsec_mode_t;
+typedef enum policy_dir_t policy_dir_t;
+typedef enum policy_type_t policy_type_t;
+typedef enum ipcomp_transform_t ipcomp_transform_t;
+typedef struct kernel_ipsec_t kernel_ipsec_t;
+typedef struct ipsec_sa_cfg_t ipsec_sa_cfg_t;
+typedef struct lifetime_cfg_t lifetime_cfg_t;
+typedef struct mark_t mark_t;
+
+#include <utils/host.h>
+#include <crypto/prf_plus.h>
+#include <selectors/traffic_selector.h>
+
+/**
+ * Mode of an IPsec SA.
+ */
+enum ipsec_mode_t {
+	/** transport mode, no inner address */
+	MODE_TRANSPORT = 1,
+	/** tunnel mode, inner and outer addresses */
+	MODE_TUNNEL,
+	/** BEET mode, tunnel mode but fixed, bound inner addresses */
+	MODE_BEET,
+};
+
+/**
+ * enum names for ipsec_mode_t.
+ */
+extern enum_name_t *ipsec_mode_names;
+
+/**
+ * Direction of a policy. These are equal to those
+ * defined in xfrm.h, but we want to stay implementation
+ * neutral here.
+ */
+enum policy_dir_t {
+	/** Policy for inbound traffic */
+	POLICY_IN = 0,
+	/** Policy for outbound traffic */
+	POLICY_OUT = 1,
+	/** Policy for forwarded traffic */
+	POLICY_FWD = 2,
+};
+
+/**
+ * enum names for policy_dir_t.
+ */
+extern enum_name_t *policy_dir_names;
+
+/**
+ * Type of a policy.
+ */
+enum policy_type_t {
+	/** Normal IPsec policy */
+	POLICY_IPSEC = 1,
+	/** Passthrough policy (traffic is ignored by IPsec) */
+	POLICY_PASS,
+	/** Drop policy (traffic is discarded) */
+	POLICY_DROP,
+};
+
+/**
+ * IPComp transform IDs, as in RFC 4306
+ */
+enum ipcomp_transform_t {
+	IPCOMP_NONE = 0,
+	IPCOMP_OUI = 1,
+	IPCOMP_DEFLATE = 2,
+	IPCOMP_LZS = 3,
+	IPCOMP_LZJH = 4,
+};
+
+/**
+ * enum strings for ipcomp_transform_t.
+ */
+extern enum_name_t *ipcomp_transform_names;
+
+/**
+ * This struct contains details about IPsec SA(s) tied to a policy.
+ */
+struct ipsec_sa_cfg_t {
+	/** mode of SA (tunnel, transport) */
+	ipsec_mode_t mode;
+	/** unique ID */
+	u_int32_t reqid;
+	/** details about ESP/AH */
+	struct {
+		/** TRUE if this protocol is used */
+		bool use;
+		/** SPI for ESP/AH */
+		u_int32_t spi;
+	} esp, ah;
+	/** details about IPComp */
+	struct {
+		/** the IPComp transform used */
+		u_int16_t transform;
+		/** CPI for IPComp */
+		u_int16_t cpi;
+	} ipcomp;
+};
+
+/**
+ * A lifetime_cfg_t defines the lifetime limits of an SA.
+ *
+ * Set any of these values to 0 to ignore.
+ */
+struct lifetime_cfg_t {
+	struct {
+		/** Limit before the SA gets invalid. */
+		u_int64_t	life;
+		/** Limit before the SA gets rekeyed. */
+		u_int64_t	rekey;
+		/** The range of a random value subtracted from rekey. */
+		u_int64_t	jitter;
+	} time, bytes, packets;
+};
+
+/**
+ * A mark_t defines an optional mark in an IPsec SA.
+ */
+struct mark_t {
+	/** Mark value */
+	u_int32_t value;
+	/** Mark mask */
+	u_int32_t mask;
+};
+
+/**
+ * Interface to the ipsec subsystem of the kernel.
+ *
+ * The kernel ipsec interface handles the communication with the kernel
+ * for SA and policy management. It allows setup of these, and provides
+ * further the handling of kernel events.
+ * Policy information are cached in the interface. This is necessary to do
+ * reference counting. The Linux kernel does not allow the same policy
+ * installed twice, but we need this as CHILD_SA exist multiple times
+ * when rekeying. Thats why we do reference counting of policies.
+ */
+struct kernel_ipsec_t {
+
+	/**
+	 * Get a SPI from the kernel.
+	 *
+	 * @param src		source address of SA
+	 * @param dst		destination address of SA
+	 * @param protocol	protocol for SA (ESP/AH)
+	 * @param reqid		unique ID for this SA
+	 * @param spi		allocated spi
+	 * @return				SUCCESS if operation completed
+	 */
+	status_t (*get_spi)(kernel_ipsec_t *this, host_t *src, host_t *dst,
+						u_int8_t protocol, u_int32_t reqid, u_int32_t *spi);
+
+	/**
+	 * Get a Compression Parameter Index (CPI) from the kernel.
+	 *
+	 * @param src		source address of SA
+	 * @param dst		destination address of SA
+	 * @param reqid		unique ID for the corresponding SA
+	 * @param cpi		allocated cpi
+	 * @return				SUCCESS if operation completed
+	 */
+	status_t (*get_cpi)(kernel_ipsec_t *this, host_t *src, host_t *dst,
+						u_int32_t reqid, u_int16_t *cpi);
+
+	/**
+	 * Add an SA to the SAD.
+	 *
+	 * add_sa() may update an already allocated
+	 * SPI (via get_spi). In this case, the replace
+	 * flag must be set.
+	 * This function does install a single SA for a
+	 * single protocol in one direction.
+	 *
+	 * @param src			source address for this SA
+	 * @param dst			destination address for this SA
+	 * @param spi			SPI allocated by us or remote peer
+	 * @param protocol		protocol for this SA (ESP/AH)
+	 * @param reqid			unique ID for this SA
+	 * @param mark			mark for this SA
+	 * @param lifetime		lifetime_cfg_t for this SA
+	 * @param enc_alg		Algorithm to use for encryption (ESP only)
+	 * @param enc_key		key to use for encryption
+	 * @param int_alg		Algorithm to use for integrity protection
+	 * @param int_key		key to use for integrity protection
+	 * @param mode			mode of the SA (tunnel, transport)
+	 * @param ipcomp		IPComp transform to use
+	 * @param cpi			CPI for IPComp
+	 * @param encap			enable UDP encapsulation for NAT traversal
+	 * @param inbound		TRUE if this is an inbound SA
+	 * @param src_ts		traffic selector with BEET source address
+	 * @param dst_ts		traffic selector with BEET destination address
+	 * @return				SUCCESS if operation completed
+	 */
+	status_t (*add_sa) (kernel_ipsec_t *this,
+						host_t *src, host_t *dst, u_int32_t spi,
+						u_int8_t protocol, u_int32_t reqid,
+						mark_t mark, lifetime_cfg_t *lifetime,
+						u_int16_t enc_alg, chunk_t enc_key,
+						u_int16_t int_alg, chunk_t int_key,
+						ipsec_mode_t mode, u_int16_t ipcomp, u_int16_t cpi,
+						bool encap, bool inbound,
+						traffic_selector_t *src_ts, traffic_selector_t *dst_ts);
+
+	/**
+	 * Update the hosts on an installed SA.
+	 *
+	 * We cannot directly update the destination address as the kernel
+	 * requires the spi, the protocol AND the destination address (and family)
+	 * to identify SAs. Therefore if the destination address changed we
+	 * create a new SA and delete the old one.
+	 *
+	 * @param spi			SPI of the SA
+	 * @param protocol		protocol for this SA (ESP/AH)
+	 * @param cpi			CPI for IPComp, 0 if no IPComp is used
+	 * @param src			current source address
+	 * @param dst			current destination address
+	 * @param new_src		new source address
+	 * @param new_dst		new destination address
+	 * @param encap			current use of UDP encapsulation
+	 * @param new_encap		new use of UDP encapsulation
+	 * @param mark			optional mark for this SA
+	 * @return				SUCCESS if operation completed, NOT_SUPPORTED if
+	 *					  the kernel interface can't update the SA
+	 */
+	status_t (*update_sa)(kernel_ipsec_t *this,
+						  u_int32_t spi, u_int8_t protocol, u_int16_t cpi,
+						  host_t *src, host_t *dst,
+						  host_t *new_src, host_t *new_dst,
+						  bool encap, bool new_encap, mark_t mark);
+
+	/**
+	 * Query the number of bytes processed by an SA from the SAD.
+	 *
+	 * @param src			source address for this SA
+	 * @param dst			destination address for this SA
+	 * @param spi			SPI allocated by us or remote peer
+	 * @param protocol		protocol for this SA (ESP/AH)
+	 * @param mark			optional mark for this SA
+	 * @param[out] bytes	the number of bytes processed by SA
+	 * @return				SUCCESS if operation completed
+	 */
+	status_t (*query_sa) (kernel_ipsec_t *this, host_t *src, host_t *dst,
+						  u_int32_t spi, u_int8_t protocol, mark_t mark,
+						  u_int64_t *bytes);
+
+	/**
+	 * Delete a previusly installed SA from the SAD.
+	 *
+	 * @param src			source address for this SA
+	 * @param dst			destination address for this SA
+	 * @param spi			SPI allocated by us or remote peer
+	 * @param protocol		protocol for this SA (ESP/AH)
+	 * @param cpi			CPI for IPComp or 0
+	 * @param mark			optional mark for this SA
+	 * @return				SUCCESS if operation completed
+	 */
+	status_t (*del_sa) (kernel_ipsec_t *this, host_t *src, host_t *dst,
+						u_int32_t spi, u_int8_t protocol, u_int16_t cpi,
+						mark_t mark);
+
+	/**
+	 * Add a policy to the SPD.
+	 *
+	 * A policy is always associated to an SA. Traffic which matches a
+	 * policy is handled by the SA with the same reqid.
+	 *
+	 * @param src			source address of SA
+	 * @param dst			dest address of SA
+	 * @param src_ts		traffic selector to match traffic source
+	 * @param dst_ts		traffic selector to match traffic dest
+	 * @param direction		direction of traffic, POLICY_(IN|OUT|FWD)
+	 * @param type			type of policy, POLICY_(IPSEC|PASS|DROP)
+	 * @param sa			details about the SA(s) tied to this policy
+	 * @param mark			mark for this policy
+	 * @param routed		TRUE, if this policy is routed in the kernel
+	 * @return				SUCCESS if operation completed
+	 */
+	status_t (*add_policy) (kernel_ipsec_t *this,
+							host_t *src, host_t *dst,
+							traffic_selector_t *src_ts,
+							traffic_selector_t *dst_ts,
+							policy_dir_t direction, policy_type_t type,
+							ipsec_sa_cfg_t *sa, mark_t mark, bool routed);
+
+	/**
+	 * Query the use time of a policy.
+	 *
+	 * The use time of a policy is the time the policy was used for the last
+	 * time. It is not the system time, but a monotonic timestamp as returned
+	 * by time_monotonic.
+	 *
+	 * @param src_ts		traffic selector to match traffic source
+	 * @param dst_ts		traffic selector to match traffic dest
+	 * @param direction		direction of traffic, POLICY_(IN|OUT|FWD)
+	 * @param mark			optional mark
+	 * @param[out] use_time	the monotonic timestamp of this SA's last use
+	 * @return				SUCCESS if operation completed
+	 */
+	status_t (*query_policy) (kernel_ipsec_t *this,
+							  traffic_selector_t *src_ts,
+							  traffic_selector_t *dst_ts,
+							  policy_dir_t direction, mark_t mark,
+							  u_int32_t *use_time);
+
+	/**
+	 * Remove a policy from the SPD.
+	 *
+	 * The kernel interface implements reference counting for policies.
+	 * If the same policy is installed multiple times (in the case of rekeying),
+	 * the reference counter is increased. del_policy() decreases the ref counter
+	 * and removes the policy only when no more references are available.
+	 *
+	 * @param src_ts		traffic selector to match traffic source
+	 * @param dst_ts		traffic selector to match traffic dest
+	 * @param direction		direction of traffic, POLICY_(IN|OUT|FWD)
+	 * @param mark			optional mark
+	 * @param unrouted		TRUE, if this policy is unrouted from the kernel
+	 * @return				SUCCESS if operation completed
+	 */
+	status_t (*del_policy) (kernel_ipsec_t *this,
+							traffic_selector_t *src_ts,
+							traffic_selector_t *dst_ts,
+							policy_dir_t direction, mark_t mark,
+							bool unrouted);
+
+	/**
+	 * Install a bypass policy for the given socket.
+	 *
+	 * @param fd			socket file descriptor to setup policy for
+	 * @param family		protocol family of the socket
+	 * @return				TRUE of policy set up successfully
+	 */
+	bool (*bypass_socket)(kernel_ipsec_t *this, int fd, int family);
+
+	/**
+	 * Destroy the implementation.
+	 */
+	void (*destroy) (kernel_ipsec_t *this);
+};
+
+#endif /** KERNEL_IPSEC_H_ @}*/
diff --git a/src/libhydra/kernel/kernel_listener.h b/src/libhydra/kernel/kernel_listener.h
new file mode 100644
index 000000000..6f2dbd23b
--- /dev/null
+++ b/src/libhydra/kernel/kernel_listener.h
@@ -0,0 +1,96 @@
+/*
+ * Copyright (C) 2010 Tobias Brunner
+ * 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.
+ */
+
+/**
+ * @defgroup kernel_listener kernel_listener
+ * @{ @ingroup hkernel
+ */
+
+#ifndef KERNEL_LISTENER_H_
+#define KERNEL_LISTENER_H_
+
+typedef struct kernel_listener_t kernel_listener_t;
+
+#include <kernel/kernel_ipsec.h>
+#include <selectors/traffic_selector.h>
+#include <utils/host.h>
+
+/**
+ * Interface for components interested in kernel events.
+ *
+ * All hooks are optional.
+ */
+struct kernel_listener_t {
+
+	/**
+	 * Hook called if an acquire event for a policy is received.
+	 *
+	 * @param reqid			reqid of the policy to acquire
+	 * @param src_ts		source traffic selector
+	 * @param dst_ts		destination traffic selector
+	 * @return				TRUE to remain registered, FALSE to unregister
+	 */
+	bool (*acquire)(kernel_listener_t *this, u_int32_t reqid,
+					traffic_selector_t *src_ts, traffic_selector_t *dst_ts);
+
+	/**
+	 * Hook called if an exire event for an IPsec SA is received.
+	 *
+	 * @param reqid			reqid of the expired SA
+	 * @param protocol		protocol of the expired SA
+	 * @param spi			spi of the expired SA
+	 * @param hard			TRUE if it is a hard expire, FALSE otherwise
+	 * @return				TRUE to remain registered, FALSE to unregister
+	 */
+	bool (*expire)(kernel_listener_t *this, u_int32_t reqid,
+				   u_int8_t protocol, u_int32_t spi, bool hard);
+
+	/**
+	 * Hook called if the NAT mappings of an IPsec SA changed.
+	 *
+	 * @param reqid			reqid of the SA
+	 * @param spi			spi of the SA
+	 * @param remote		new remote host
+	 * @return				TRUE to remain registered, FALSE to unregister
+	 */
+	bool (*mapping)(kernel_listener_t *this, u_int32_t reqid, u_int32_t spi,
+					host_t *remote);
+
+	/**
+	 * Hook called if a migrate event for a policy is received.
+	 *
+	 * @param reqid			reqid of the policy
+	 * @param src_ts		source traffic selector
+	 * @param dst_ts		destination traffic selector
+	 * @param direction		direction of the policy (in|out)
+	 * @param local			local host address to be used in the IKE_SA
+	 * @param remote		remote host address to be used in the IKE_SA
+	 * @return				TRUE to remain registered, FALSE to unregister
+	 */
+	bool (*migrate)(kernel_listener_t *this, u_int32_t reqid,
+					traffic_selector_t *src_ts, traffic_selector_t *dst_ts,
+					policy_dir_t direction, host_t *local, host_t *remote);
+
+	/**
+	 * Hook called if changes in the networking layer occured (interfaces
+	 * up/down, routes added/deleted etc.).
+	 *
+	 * @param address		TRUE if address list, FALSE if routing changed
+	 * @return				TRUE to remain registered, FALSE to unregister
+	 */
+	bool (*roam)(kernel_listener_t *this, bool address);
+};
+
+#endif /** KERNEL_LISTENER_H_ @}*/
diff --git a/src/libhydra/kernel/kernel_net.h b/src/libhydra/kernel/kernel_net.h
new file mode 100644
index 000000000..69e01f43f
--- /dev/null
+++ b/src/libhydra/kernel/kernel_net.h
@@ -0,0 +1,145 @@
+/*
+ * Copyright (C) 2008 Tobias Brunner
+ * Copyright (C) 2007 Martin Willi
+ * 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.
+ */
+
+/**
+ * @defgroup kernel_net kernel_net
+ * @{ @ingroup hkernel
+ */
+
+#ifndef KERNEL_NET_H_
+#define KERNEL_NET_H_
+
+typedef struct kernel_net_t kernel_net_t;
+
+#include <utils/enumerator.h>
+#include <utils/host.h>
+
+/**
+ * Interface to the network subsystem of the kernel.
+ *
+ * The kernel network interface handles the communication with the kernel
+ * for interface and IP address management.
+ */
+struct kernel_net_t {
+
+	/**
+	 * Get our outgoing source address for a destination.
+	 *
+	 * Does a route lookup to get the source address used to reach dest.
+	 * The returned host is allocated and must be destroyed.
+	 * An optional src address can be used to check if a route is available
+	 * for given source to dest.
+	 *
+	 * @param dest			target destination address
+	 * @param src			source address to check, or NULL
+	 * @return				outgoing source address, NULL if unreachable
+	 */
+	host_t* (*get_source_addr)(kernel_net_t *this, host_t *dest, host_t *src);
+
+	/**
+	 * Get the next hop for a destination.
+	 *
+	 * Does a route lookup to get the next hop used to reach dest.
+	 * The returned host is allocated and must be destroyed.
+	 *
+	 * @param dest			target destination address
+	 * @return				next hop address, NULL if unreachable
+	 */
+	host_t* (*get_nexthop)(kernel_net_t *this, host_t *dest);
+
+	/**
+	 * Get the interface name of a local address.
+	 *
+	 * @param host			address to get interface name from
+	 * @return				allocated interface name, or NULL if not found
+	 */
+	char* (*get_interface) (kernel_net_t *this, host_t *host);
+
+	/**
+	 * Creates an enumerator over all local addresses.
+	 *
+	 * This function blocks an internal cached address list until the
+	 * enumerator gets destroyed.
+	 * The hosts are read-only, do not modify of free.
+	 *
+	 * @param include_down_ifaces	TRUE to enumerate addresses from down interfaces
+	 * @param include_virtual_ips	TRUE to enumerate virtual ip addresses
+	 * @return						enumerator over host_t's
+	 */
+	enumerator_t *(*create_address_enumerator) (kernel_net_t *this,
+						bool include_down_ifaces, bool include_virtual_ips);
+
+	/**
+	 * Add a virtual IP to an interface.
+	 *
+	 * Virtual IPs are attached to an interface. If an IP is added multiple
+	 * times, the IP is refcounted and not removed until del_ip() was called
+	 * as many times as add_ip().
+	 * The virtual IP is attached to the interface where the iface_ip is found.
+	 *
+	 * @param virtual_ip	virtual ip address to assign
+	 * @param iface_ip		IP of an interface to attach virtual IP
+	 * @return				SUCCESS if operation completed
+	 */
+	status_t (*add_ip) (kernel_net_t *this, host_t *virtual_ip,
+						host_t *iface_ip);
+
+	/**
+	 * Remove a virtual IP from an interface.
+	 *
+	 * The kernel interface uses refcounting, see add_ip().
+	 *
+	 * @param virtual_ip	virtual ip address to assign
+	 * @return				SUCCESS if operation completed
+	 */
+	status_t (*del_ip) (kernel_net_t *this, host_t *virtual_ip);
+
+	/**
+	 * Add a route.
+	 *
+	 * @param dst_net		destination net
+	 * @param prefixlen		destination net prefix length
+	 * @param gateway		gateway for this route
+	 * @param src_ip		sourc ip of the route
+	 * @param if_name		name of the interface the route is bound to
+	 * @return				SUCCESS if operation completed
+	 *						ALREADY_DONE if the route already exists
+	 */
+	status_t (*add_route) (kernel_net_t *this, chunk_t dst_net,
+						   u_int8_t prefixlen, host_t *gateway, host_t *src_ip,
+						   char *if_name);
+
+	/**
+	 * Delete a route.
+	 *
+	 * @param dst_net		destination net
+	 * @param prefixlen		destination net prefix length
+	 * @param gateway		gateway for this route
+	 * @param src_ip		sourc ip of the route
+	 * @param if_name		name of the interface the route is bound to
+	 * @return				SUCCESS if operation completed
+	 */
+	status_t (*del_route) (kernel_net_t *this, chunk_t dst_net,
+						   u_int8_t prefixlen, host_t *gateway, host_t *src_ip,
+						   char *if_name);
+
+	/**
+	 * Destroy the implementation.
+	 */
+	void (*destroy) (kernel_net_t *this);
+};
+
+#endif /** KERNEL_NET_H_ @}*/