experimental P2P-NAT-T for IKEv2 merged back from branch

40 files changed, 5104 insertions, 31 deletions

diff --git a/src/charon/Makefile.am b/src/charon/Makefile.am
index 8434ebb1c..0d783cbbb 100644
--- a/src/charon/Makefile.am
+++ b/src/charon/Makefile.am
@@ -85,6 +85,14 @@ sa/tasks/ike_rekey.c sa/tasks/ike_rekey.h \
 sa/tasks/ike_reauth.c sa/tasks/ike_reauth.h \
 sa/tasks/task.c sa/tasks/task.h
 
+if USE_P2P
+  charon_SOURCES += encoding/payloads/endpoint_notify.c encoding/payloads/endpoint_notify.h \
+    processing/jobs/initiate_mediation_job.c processing/jobs/initiate_mediation_job.h \
+    processing/jobs/mediation_job.c processing/jobs/mediation_job.h \
+    sa/connect_manager.c sa/connect_manager.h \
+    sa/mediation_manager.c sa/mediation_manager.h \
+    sa/tasks/ike_p2p.c sa/tasks/ike_p2p.h
+endif
 
 INCLUDES = -I${linuxdir} -I$(top_srcdir)/src/libstrongswan -I$(top_srcdir)/src/charon -I$(top_srcdir)/src/stroke
 AM_CFLAGS = -rdynamic -DIPSEC_CONFDIR=\"${confdir}\" -DIPSEC_DIR=\"${ipsecdir}\" -DIPSEC_PIDDIR=\"${piddir}\" \
diff --git a/src/charon/config/peer_cfg.c b/src/charon/config/peer_cfg.c
index 6733df08c..d61ed9512 100644
--- a/src/charon/config/peer_cfg.c
+++ b/src/charon/config/peer_cfg.c
@@ -6,6 +6,7 @@
  */
 
 /*
+ * Copyright (C) 2007 Tobias Brunner
  * Copyright (C) 2005-2007 Martin Willi
  * Copyright (C) 2005 Jan Hutter
  * Hochschule fuer Technik Rapperswil
@@ -175,6 +176,24 @@ struct private_peer_cfg_t {
 	 * virtual IP to use remotly
 	 */
 	host_t *other_virtual_ip;
+
+#ifdef P2P	
+	/**
+	 * Is this a mediation connection?
+	 */
+	bool p2p_mediation;
+	
+	/**
+	 * Name of the mediation connection to mediate through
+	 */
+	peer_cfg_t *p2p_mediated_by;
+	
+	/**
+	 * ID of our peer at the mediation server (= leftid of the peer's conn with
+	 * the mediation server)
+	 */
+	identification_t *peer_id;
+#endif /* P2P */
 };
 
 /**
@@ -413,6 +432,36 @@ static host_t* get_other_virtual_ip(private_peer_cfg_t *this, host_t *suggestion
 	return suggestion->clone(suggestion);
 }
 
+#ifdef P2P
+/**
+ * Implementation of peer_cfg_t.is_mediation.
+ */
+static bool is_mediation(private_peer_cfg_t *this)
+{
+	return this->p2p_mediation;
+}
+
+/**
+ * Implementation of peer_cfg_t.get_mediated_by.
+ */
+static peer_cfg_t* get_mediated_by(private_peer_cfg_t *this)
+{
+	if (this->p2p_mediated_by) {
+		this->p2p_mediated_by->get_ref(this->p2p_mediated_by);
+		return this->p2p_mediated_by;
+	}
+	return NULL;
+}
+
+/**
+ * Implementation of peer_cfg_t.get_peer_id.
+ */
+static identification_t* get_peer_id(private_peer_cfg_t *this)
+{
+	return this->peer_id;
+}
+#endif /* P2P */
+
 /**
  * Implements peer_cfg_t.get_ref.
  */
@@ -436,6 +485,10 @@ static void destroy(private_peer_cfg_t *this)
 		DESTROY_IF(this->other_ca);
 		DESTROY_IF(this->my_virtual_ip);
 		DESTROY_IF(this->other_virtual_ip);
+#ifdef P2P
+		DESTROY_IF(this->p2p_mediated_by);
+		DESTROY_IF(this->peer_id);
+#endif /* P2P */
 		ietfAttr_list_destroy(this->groups);
 		free(this->name);
 		free(this);
@@ -454,7 +507,9 @@ peer_cfg_t *peer_cfg_create(char *name, u_int ike_version, ike_cfg_t *ike_cfg,
 							u_int32_t rekeytime, u_int32_t jitter,
 							bool reauth, bool mobike,
 							u_int32_t dpd_delay, dpd_action_t dpd_action,
-							host_t *my_virtual_ip, host_t *other_virtual_ip)
+							host_t *my_virtual_ip, host_t *other_virtual_ip,
+							bool p2p_mediation, peer_cfg_t *p2p_mediated_by,
+							identification_t *peer_id)
 {
 	private_peer_cfg_t *this = malloc_thing(private_peer_cfg_t);
 
@@ -483,6 +538,11 @@ peer_cfg_t *peer_cfg_create(char *name, u_int ike_version, ike_cfg_t *ike_cfg,
 	this->public.get_other_virtual_ip = (host_t* (*) (peer_cfg_t *, host_t *))get_other_virtual_ip;
 	this->public.get_ref = (void(*)(peer_cfg_t *))get_ref;
 	this->public.destroy = (void(*)(peer_cfg_t *))destroy;
+#ifdef P2P	
+	this->public.is_mediation = (bool (*) (peer_cfg_t *))is_mediation;
+	this->public.get_mediated_by = (peer_cfg_t* (*) (peer_cfg_t *))get_mediated_by;
+	this->public.get_peer_id = (identification_t* (*) (peer_cfg_t *))get_peer_id;
+#endif /* P2P */
 	
 	/* apply init values */
 	this->name = strdup(name);
@@ -509,6 +569,11 @@ peer_cfg_t *peer_cfg_create(char *name, u_int ike_version, ike_cfg_t *ike_cfg,
 	this->my_virtual_ip = my_virtual_ip;
 	this->other_virtual_ip = other_virtual_ip;
 	this->refcount = 1;
+#ifdef P2P
+	this->p2p_mediation = p2p_mediation;
+	this->p2p_mediated_by = p2p_mediated_by;
+	this->peer_id = peer_id;
+#endif /* P2P */
 
 	return &this->public;
 }
diff --git a/src/charon/config/peer_cfg.h b/src/charon/config/peer_cfg.h
index ea53a80e7..3d238e6aa 100644
--- a/src/charon/config/peer_cfg.h
+++ b/src/charon/config/peer_cfg.h
@@ -6,6 +6,7 @@
  */
 
 /*
+ * Copyright (C) 2007 Tobias Brunner
  * Copyright (C) 2005-2007 Martin Willi
  * Copyright (C) 2005 Jan Hutter
  * Hochschule fuer Technik Rapperswil
@@ -314,6 +315,37 @@ struct peer_cfg_t {
 	 * @return				clone of an IP to use
 	 */
 	host_t* (*get_other_virtual_ip) (peer_cfg_t *this, host_t *suggestion);
+
+#ifdef P2P	
+	/**
+	 * @brief Is this a mediation connection?
+	 * 
+	 * @param this			peer_cfg
+	 * @return				TRUE, if this is a mediation connection
+	 */
+	bool (*is_mediation) (peer_cfg_t *this);
+	
+	/**
+	 * @brief Get peer_cfg of the connection this one is mediated through.
+	 * 
+	 * @param this			peer_cfg
+	 * @return				reference to peer_cfg of the mediation connection
+	 */
+	peer_cfg_t* (*get_mediated_by) (peer_cfg_t *this);
+	
+	/**
+	 * @brief Get the id of the other peer at the mediation server.
+	 * 
+	 * This is the leftid of the peer's connection with the mediation server.
+	 * 
+	 * If it is not configured, it is assumed to be the same as the right id
+	 * of this connection. 
+	 * 
+	 * @param this			peer_cfg
+	 * @return				the id of the other peer
+	 */
+	identification_t* (*get_peer_id) (peer_cfg_t *this);
+#endif /* P2P */
 	
 	/**
 	 * @brief Get a new reference.
@@ -370,6 +402,9 @@ struct peer_cfg_t {
  * @param dpd_action		what to do with CHILD_SAs when detected a dead peer
  * @param my_virtual_ip		virtual IP for local host, or NULL
  * @param other_virtual_ip	virtual IP for remote host, or NULL
+ * @param p2p_mediation		TRUE if this is a mediation connection
+ * @param p2p_mediated_by	name of the mediation connection to mediate through
+ * @param peer_id			ID that identifies our peer at the mediation server
  * @return 					peer_cfg_t object
  * 
  * @ingroup config
@@ -383,6 +418,8 @@ peer_cfg_t *peer_cfg_create(char *name, u_int ikev_version, ike_cfg_t *ike_cfg,
 							u_int32_t rekeytime, u_int32_t jitter,
 							bool reauth, bool mobike,
 							u_int32_t dpd_delay, dpd_action_t dpd_action,
-							host_t *my_virtual_ip, host_t *other_virtual_ip);
+							host_t *my_virtual_ip, host_t *other_virtual_ip,
+							bool p2p_mediation, peer_cfg_t *p2p_mediated_by,
+							identification_t *peer_id);
 
 #endif /* PEER_CFG_H_ */
diff --git a/src/charon/control/interfaces/stroke_interface.c b/src/charon/control/interfaces/stroke_interface.c
index 6b88c7105..fce9bfeb7 100755
--- a/src/charon/control/interfaces/stroke_interface.c
+++ b/src/charon/control/interfaces/stroke_interface.c
@@ -6,6 +6,7 @@
  */
 
 /*
+ * Copyright (C) 2007 Tobias Brunner
  * Copyright (C) 2006-2007 Martin Willi
  * Hochschule fuer Technik Rapperswil
  *
@@ -228,10 +229,12 @@ static void stroke_add_conn(stroke_msg_t *msg, FILE *out)
 {
 	ike_cfg_t *ike_cfg;
 	peer_cfg_t *peer_cfg;
+	peer_cfg_t *mediated_by_cfg = NULL;
 	child_cfg_t *child_cfg;
 	identification_t *my_id, *other_id;
 	identification_t *my_ca = NULL;
 	identification_t *other_ca = NULL;
+	identification_t *peer_id = NULL;
 	bool my_ca_same = FALSE;
 	bool other_ca_same =FALSE;
 	host_t *my_host, *other_host, *my_subnet, *other_subnet;
@@ -253,7 +256,12 @@ static void stroke_add_conn(stroke_msg_t *msg, FILE *out)
 	pop_string(msg, &msg->add_conn.algorithms.esp);
 	DBG2(DBG_CFG, "  ike=%s", msg->add_conn.algorithms.ike);
 	DBG2(DBG_CFG, "  esp=%s", msg->add_conn.algorithms.esp);
-	
+	pop_string(msg, &msg->add_conn.p2p.mediated_by);
+	pop_string(msg, &msg->add_conn.p2p.peerid);
+	DBG2(DBG_CFG, "  p2p_mediation=%s", msg->add_conn.p2p.mediation ? "yes" : "no");
+	DBG2(DBG_CFG, "  p2p_mediated_by=%s", msg->add_conn.p2p.mediated_by);
+	DBG2(DBG_CFG, "  p2p_peerid=%s", msg->add_conn.p2p.peerid);
+
 	my_host = msg->add_conn.me.address?
 			  host_create_from_string(msg->add_conn.me.address, IKE_PORT) : NULL;
 	if (my_host == NULL)
@@ -320,6 +328,49 @@ static void stroke_add_conn(stroke_msg_t *msg, FILE *out)
 		goto destroy_hosts;
 	}
 	
+#ifdef P2P
+	if (msg->add_conn.p2p.mediation && msg->add_conn.p2p.mediated_by)
+	{
+		DBG1(DBG_CFG, "a mediation connection cannot be a"
+				" mediated connection at the same time, aborting");
+		goto destroy_ids;
+	}
+	
+	if (msg->add_conn.p2p.mediated_by)
+	{
+		mediated_by_cfg = charon->backends->get_peer_cfg_by_name(charon->backends, msg->add_conn.p2p.mediated_by);
+		if (!mediated_by_cfg)
+		{
+			DBG1(DBG_CFG, "mediation connection '%s' not found, aborting",
+					msg->add_conn.p2p.mediated_by);
+			goto destroy_ids;
+		}
+		
+		if (!mediated_by_cfg->is_mediation(mediated_by_cfg))
+		{
+			DBG1(DBG_CFG, "connection '%s' as referred to by '%s' is"
+					"no mediation connection, aborting", 
+					msg->add_conn.p2p.mediated_by, msg->add_conn.name);
+			goto destroy_ids;
+		}
+	}
+	
+	if (msg->add_conn.p2p.peerid)
+	{
+		peer_id = identification_create_from_string(msg->add_conn.p2p.peerid);
+		if (!peer_id)
+		{
+			DBG1(DBG_CFG, "invalid peer ID: %s\n", msg->add_conn.p2p.peerid);
+			goto destroy_ids;
+		}
+	}
+	else
+#endif /* P2P */
+	{
+		// no peer ID supplied, assume right ID
+		peer_id = other_id->clone(other_id);
+	}
+	
 	my_subnet = host_create_from_string(msg->add_conn.me.subnet ?
 					msg->add_conn.me.subnet : msg->add_conn.me.address, IKE_PORT);
 	if (my_subnet == NULL)
@@ -513,6 +564,8 @@ static void stroke_add_conn(stroke_msg_t *msg, FILE *out)
 		other_host->destroy(other_host);
 		other_id->destroy(other_id);
 		other_ca->destroy(other_ca);
+		peer_id->destroy(peer_id);
+		DESTROY_IF(mediated_by_cfg);
 		ietfAttr_list_destroy(my_groups);
 		ietfAttr_list_destroy(other_groups);
 	}
@@ -568,9 +621,9 @@ static void stroke_add_conn(stroke_msg_t *msg, FILE *out)
 					msg->add_conn.rekey.tries, msg->add_conn.rekey.ike_lifetime,
 					msg->add_conn.rekey.ike_lifetime - msg->add_conn.rekey.margin,
 					msg->add_conn.rekey.margin * msg->add_conn.rekey.fuzz / 100, 
-					msg->add_conn.rekey.reauth, msg->add_conn.mobike, 
-					msg->add_conn.dpd.delay, msg->add_conn.dpd.action,
-					my_vip, other_vip);
+					msg->add_conn.rekey.reauth, msg->add_conn.mobike,
+					msg->add_conn.dpd.delay, msg->add_conn.dpd.action, my_vip, other_vip,
+					msg->add_conn.p2p.mediation, mediated_by_cfg, peer_id);
 	}
 	
 	child_cfg = child_cfg_create(
@@ -632,6 +685,8 @@ static void stroke_add_conn(stroke_msg_t *msg, FILE *out)
 destroy_ids:
 	my_id->destroy(my_id);
 	other_id->destroy(other_id);
+	DESTROY_IF(mediated_by_cfg);
+	DESTROY_IF(peer_id);
 
 destroy_hosts:
 	my_host->destroy(my_host);
diff --git a/src/charon/daemon.c b/src/charon/daemon.c
index 2d31e7ad6..9e151c305 100644
--- a/src/charon/daemon.c
+++ b/src/charon/daemon.c
@@ -5,8 +5,8 @@
  * 
  */
 
-/*
- * Copyright (C) 2006 Tobias Brunner, Daniel Roethlisberger
+/* Copyright (C) 2006-2007 Tobias Brunner
+ * Copyright (C) 2006 Daniel Roethlisberger
  * Copyright (C) 2005-2006 Martin Willi
  * Copyright (C) 2005 Jan Hutter
  * Hochschule fuer Technik Rapperswil
@@ -177,6 +177,10 @@ static void destroy(private_daemon_t *this)
 	DESTROY_IF(this->public.kernel_interface);
 	DESTROY_IF(this->public.scheduler);
 	DESTROY_IF(this->public.interfaces);
+#ifdef P2P	
+	DESTROY_IF(this->public.connect_manager);
+	DESTROY_IF(this->public.mediation_manager);
+#endif /* P2P */
 	DESTROY_IF(this->public.backends);
 	DESTROY_IF(this->public.credentials);
 	DESTROY_IF(this->public.sender);
@@ -337,6 +341,12 @@ static bool initialize(private_daemon_t *this, bool syslog, level_t levels[])
 	this->public.socket = socket_create(IKEV2_UDP_PORT, IKEV2_NATT_PORT);
 	this->public.sender = sender_create();
 	this->public.receiver = receiver_create();
+	
+#ifdef P2P
+	this->public.connect_manager = connect_manager_create();
+	this->public.mediation_manager = mediation_manager_create();
+#endif /* P2P */
+	
 	return TRUE;
 }
 
diff --git a/src/charon/daemon.h b/src/charon/daemon.h
index 0b5205ce7..33c63091d 100644
--- a/src/charon/daemon.h
+++ b/src/charon/daemon.h
@@ -6,7 +6,8 @@
  */
 
 /*
- * Copyright (C) 2006 Tobias Brunner, Daniel Roethlisberger
+ * Copyright (C) 2006-2007 Tobias Brunner
+ * Copyright (C) 2006 Daniel Roethlisberger
  * Copyright (C) 2005-2006 Martin Willi
  * Copyright (C) 2005 Jan Hutter
  * Hochschule fuer Technik Rapperswil
@@ -42,6 +43,11 @@ typedef struct daemon_t daemon_t;
 #include <sa/ike_sa_manager.h>
 #include <config/backend_manager.h>
 
+#ifdef P2P
+#include <sa/connect_manager.h>
+#include <sa/mediation_manager.h>
+#endif /* P2P */
+
 /**
  * @defgroup charon charon
  *
@@ -427,6 +433,18 @@ struct daemon_t {
 	 */
 	interface_manager_t *interfaces;
 	
+#ifdef P2P
+	/**
+	 * Connect manager
+	 */
+	connect_manager_t *connect_manager;
+	
+	/**
+	 * Mediation manager
+	 */
+	mediation_manager_t *mediation_manager;
+#endif /* P2P */
+	
 	/**
 	 * @brief Shut down the daemon.
 	 * 
diff --git a/src/charon/encoding/message.c b/src/charon/encoding/message.c
index 567fed44f..3dfa64fb9 100644
--- a/src/charon/encoding/message.c
+++ b/src/charon/encoding/message.c
@@ -150,9 +150,15 @@ static payload_rule_t ike_auth_i_payload_rules[] = {
 	{CERTIFICATE,0,1,TRUE,FALSE},
 	{CERTIFICATE_REQUEST,0,1,TRUE,FALSE},
 	{ID_RESPONDER,0,1,TRUE,FALSE},
+#ifdef P2P
+	{SECURITY_ASSOCIATION,0,1,TRUE,FALSE},
+	{TRAFFIC_SELECTOR_INITIATOR,0,1,TRUE,FALSE},
+	{TRAFFIC_SELECTOR_RESPONDER,0,1,TRUE,FALSE},
+#else
 	{SECURITY_ASSOCIATION,1,1,TRUE,FALSE},
 	{TRAFFIC_SELECTOR_INITIATOR,1,1,TRUE,FALSE},
 	{TRAFFIC_SELECTOR_RESPONDER,1,1,TRUE,FALSE},
+#endif /* P2P */
 	{CONFIGURATION,0,1,TRUE,FALSE},
 	{VENDOR_ID,0,10,TRUE,FALSE},
 };
@@ -223,6 +229,24 @@ static payload_rule_t create_child_sa_r_payload_rules[] = {
 	{VENDOR_ID,0,10,TRUE,FALSE},
 };
 
+#ifdef P2P
+/**
+ * Message rule for P2P_CONNECT from initiator.
+ */
+static payload_rule_t p2p_connect_i_payload_rules[] = {
+	{NOTIFY,0,MAX_NOTIFY_PAYLOADS,TRUE,TRUE},
+	{ID_PEER,1,1,TRUE,FALSE},
+	{VENDOR_ID,0,10,TRUE,FALSE}
+};
+
+/**
+ * Message rule for P2P_CONNECT from responder.
+ */
+static payload_rule_t p2p_connect_r_payload_rules[] = {
+	{NOTIFY,0,MAX_NOTIFY_PAYLOADS,TRUE,TRUE},
+	{VENDOR_ID,0,10,TRUE,FALSE}
+};
+#endif /* P2P */
 
 /**
  * Message rules, defines allowed payloads.
@@ -236,6 +260,10 @@ static message_rule_t message_rules[] = {
 	{INFORMATIONAL,FALSE,TRUE,(sizeof(informational_r_payload_rules)/sizeof(payload_rule_t)),informational_r_payload_rules},
 	{CREATE_CHILD_SA,TRUE,TRUE,(sizeof(create_child_sa_i_payload_rules)/sizeof(payload_rule_t)),create_child_sa_i_payload_rules},
 	{CREATE_CHILD_SA,FALSE,TRUE,(sizeof(create_child_sa_r_payload_rules)/sizeof(payload_rule_t)),create_child_sa_r_payload_rules},
+#ifdef P2P
+	{P2P_CONNECT,TRUE,TRUE,(sizeof(p2p_connect_i_payload_rules)/sizeof(payload_rule_t)),p2p_connect_i_payload_rules},
+	{P2P_CONNECT,FALSE,TRUE,(sizeof(p2p_connect_r_payload_rules)/sizeof(payload_rule_t)),p2p_connect_r_payload_rules},
+#endif /* P2P */	
 };
 
 
diff --git a/src/charon/encoding/payloads/endpoint_notify.c b/src/charon/encoding/payloads/endpoint_notify.c
new file mode 100644
index 000000000..30f3ecd5f
--- /dev/null
+++ b/src/charon/encoding/payloads/endpoint_notify.c
@@ -0,0 +1,422 @@
+/**
+ * @file endpoint_notify.c
+ * 
+ * @brief Implementation of endpoint_notify_t.
+ * 
+ */
+
+/*
+ * Copyright (C) 2007 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 "endpoint_notify.h"
+
+#include <math.h>
+
+#include <daemon.h>
+
+typedef struct private_endpoint_notify_t private_endpoint_notify_t;
+
+/**
+ * Private data of an notify_payload_t object.
+ * 
+ */
+struct private_endpoint_notify_t {
+	/**
+	 * Public endpoint_notify_t interface.
+	 */
+	endpoint_notify_t public;
+	
+	/**
+	 * Priority
+	 */
+	u_int32_t priority;
+	
+	/**
+	 * Family
+	 */
+	p2p_endpoint_family_t family;
+		
+	/**
+	 * Endpoint type
+	 */
+	p2p_endpoint_type_t type;
+	
+	/**
+	 * Endpoint
+	 */
+	host_t *endpoint;
+	
+	/**
+	 * Base (used for server reflexive endpoints)
+	 */
+	host_t *base;
+};
+
+/*    Notification data:
+                           1                   2                   3
+       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+      !                           Priority                            !
+      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+      !     Family    !      Type     !              Port             !
+      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+      !                       IP Address (variable)                   
+      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+*/
+
+/**
+ * Helper functions to parse integer values
+ */
+static status_t parse_uint8(u_int8_t **cur, u_int8_t *top, u_int8_t *val)
+{
+	if (*cur + sizeof(u_int8_t) > top)
+	{
+		return FAILED;
+	}
+	*val =  *(u_int8_t*)*cur;
+	*cur += sizeof(u_int8_t);
+	return SUCCESS;
+}
+
+static status_t parse_uint16(u_int8_t **cur, u_int8_t *top, u_int16_t *val)
+{
+	if (*cur + sizeof(u_int16_t) > top)
+	{
+		return FAILED;
+	}
+	*val =  ntohs(*(u_int16_t*)*cur);
+	*cur += sizeof(u_int16_t);
+	return SUCCESS;
+}
+
+static status_t parse_uint32(u_int8_t **cur, u_int8_t *top, u_int32_t *val)
+{
+	if (*cur + sizeof(u_int32_t) > top)
+	{
+		return FAILED;
+	}
+	*val =  ntohl(*(u_int32_t*)*cur);
+	*cur += sizeof(u_int32_t);
+	return SUCCESS;
+}
+
+/**
+ * Parses the notification data of a P2P_ENDPOINT notify
+ */
+static status_t parse_notification_data(private_endpoint_notify_t *this, chunk_t data)
+{
+	u_int8_t family, type, addr_family;
+	u_int16_t port;
+	chunk_t addr;
+	u_int8_t *cur = data.ptr;
+	u_int8_t *top = data.ptr + data.len;
+	
+	DBG3(DBG_IKE, "p2p_endpoint_data %B", &data);
+	
+	if (parse_uint32(&cur, top, &this->priority) != SUCCESS)
+	{
+		DBG1(DBG_IKE, "failed to parse P2P_ENDPOINT: invalid priority");
+		return FAILED;
+	}
+
+	if (parse_uint8(&cur, top, &family) != SUCCESS || family >= MAX_FAMILY)
+	{
+		DBG1(DBG_IKE, "failed to parse P2P_ENDPOINT: invalid family");
+		return FAILED;
+	}
+	
+	this->family = (p2p_endpoint_family_t)family;
+	
+	if (parse_uint8(&cur, top, &type) != SUCCESS || type >= MAX_TYPE)
+	{
+		DBG1(DBG_IKE, "failed to parse P2P_ENDPOINT: invalid type");
+		return FAILED;
+	}
+	
+	this->type = (p2p_endpoint_type_t)type;
+	
+	addr_family = AF_INET;
+	addr.len = 4;
+	
+	switch(this->family)
+	{
+		case NO_FAMILY:
+			this->endpoint = NULL;
+			break;
+	
+		case IPv6:
+			addr_family = AF_INET6;
+			addr.len = 16;
+			// fall-through
+		case IPv4:
+			if (parse_uint16(&cur, top, &port) != SUCCESS)
+			{
+				DBG1(DBG_IKE, "failed to parse P2P_ENDPOINT: invalid port");
+				return FAILED;	
+			}
+			
+			if (cur + addr.len > top)
+			{
+				DBG1(DBG_IKE, "failed to parse P2P_ENDPOINT: invalid IP address");
+				return FAILED;
+			}
+			
+			addr.ptr = cur;
+			
+			this->endpoint = host_create_from_chunk(addr_family, addr, port);
+			break;
+	}	
+	
+	return SUCCESS;
+}
+
+
+/**
+ * Generates the notification data of a P2P_ENDPOINT notify
+ */
+static chunk_t build_notification_data(private_endpoint_notify_t *this)
+{
+	chunk_t prio_chunk, family_chunk, type_chunk, port_chunk, addr_chunk;
+	chunk_t data;
+	u_int32_t prio;
+	u_int16_t port;
+	u_int8_t family, type;
+	
+	prio = htonl(this->priority);
+	prio_chunk = chunk_from_thing(prio);
+	family = this->family;
+	family_chunk = chunk_from_thing(family);
+	type = this->type;
+	type_chunk = chunk_from_thing(type);
+	
+	if (this->endpoint)
+	{
+		port = htons(this->endpoint->get_port(this->endpoint));
+		addr_chunk = this->endpoint->get_address(this->endpoint);
+	}
+	else
+	{
+		port = 0;
+		addr_chunk = chunk_empty; 
+	}
+	port_chunk = chunk_from_thing(port);
+	
+	// data = prio | family | type | port | addr
+	data = chunk_cat("ccccc", prio_chunk, family_chunk, type_chunk,
+			port_chunk, addr_chunk);
+	DBG3(DBG_IKE, "p2p_endpoint_data %B", &data);
+	
+	return data;
+}
+
+/**
+ * Implementation of endpoint_notify_t.build_notify
+ */
+static notify_payload_t *build_notify(private_endpoint_notify_t *this)
+{
+	chunk_t data;
+	notify_payload_t *notify;	
+	
+	notify = notify_payload_create();
+	notify->set_notify_type(notify, P2P_ENDPOINT);
+	data = build_notification_data(this);
+	notify->set_notification_data(notify, data);
+	chunk_free(&data);
+	
+	return notify;
+}
+
+/**
+ * Implementation of endpoint_notify_t.get_priority.
+ */
+static u_int32_t get_priority(private_endpoint_notify_t *this)
+{
+	return this->priority;
+}
+
+/**
+ * Implementation of endpoint_notify_t.set_priority.
+ */
+static void set_priority(private_endpoint_notify_t *this, u_int32_t priority)
+{
+	return this->priority = priority;
+}
+
+/**
+ * Implementation of endpoint_notify_t.get_type.
+ */
+static p2p_endpoint_type_t get_type(private_endpoint_notify_t *this)
+{
+	return this->type;
+}
+
+/**
+ * Implementation of endpoint_notify_t.get_family.
+ */
+static p2p_endpoint_family_t get_family(private_endpoint_notify_t *this)
+{
+	return this->family;
+}
+
+/**
+ * Implementation of endpoint_notify_t.get_host.
+ */
+static host_t *get_host(private_endpoint_notify_t *this)
+{
+	return this->endpoint;
+}
+
+/**
+ * Implementation of endpoint_notify_t.get_base.
+ */
+static host_t *get_base(private_endpoint_notify_t *this)
+{
+	return (!this->base) ? this->endpoint : this->base;
+}
+
+/**
+ * Implementation of endpoint_notify_t.clone.
+ */
+static endpoint_notify_t *_clone(private_endpoint_notify_t *this)
+{
+	private_endpoint_notify_t *clone = (private_endpoint_notify_t*)endpoint_notify_create();
+	
+	clone->priority = this->priority;
+	clone->type = this->type;
+	clone->family = this->family;
+	if (this->endpoint)
+	{
+		clone->endpoint = this->endpoint->clone(this->endpoint);
+	}
+	
+	if (this->base)
+	{
+		clone->base = this->base->clone(this->base);
+	}
+	
+	return &clone->public;
+}
+
+/**
+ * Implementation of endpoint_notify_t.destroy.
+ */
+static status_t destroy(private_endpoint_notify_t *this)
+{
+	DESTROY_IF(this->endpoint);
+	free(this);
+	return SUCCESS;
+}
+
+/*
+ * Described in header
+ */
+endpoint_notify_t *endpoint_notify_create()
+{
+	private_endpoint_notify_t *this = malloc_thing(private_endpoint_notify_t);
+
+	/* public functions */
+	this->public.get_priority = (u_int32_t (*) (endpoint_notify_t *)) get_priority;
+	this->public.set_priority = (void (*) (endpoint_notify_t *, u_int32_t)) set_priority;
+	this->public.get_type = (p2p_endpoint_type_t (*) (endpoint_notify_t *)) get_type;
+	this->public.get_family = (p2p_endpoint_family_t (*) (endpoint_notify_t *)) get_family;
+	this->public.get_host = (host_t *(*) (endpoint_notify_t *)) get_host;
+	this->public.get_base = (host_t *(*) (endpoint_notify_t *)) get_base;
+	this->public.build_notify = (notify_payload_t *(*) (endpoint_notify_t *)) build_notify;
+	this->public.clone = (endpoint_notify_t *(*) (endpoint_notify_t *)) _clone;
+	this->public.destroy = (void (*) (endpoint_notify_t *)) destroy;
+	
+	/* set default values of the fields */
+	this->priority = 0;
+	this->family = NO_FAMILY;
+	this->type = NO_TYPE;
+	this->endpoint = NULL;
+	this->base = NULL;
+	
+	return &this->public;
+}
+
+/**
+ * Described in header
+ */
+endpoint_notify_t *endpoint_notify_create_from_host(p2p_endpoint_type_t type, host_t *host, host_t *base)
+{
+	private_endpoint_notify_t *this = (private_endpoint_notify_t*)endpoint_notify_create();
+	
+	this->type = type;
+	
+	switch(type)
+	{
+		case HOST:
+			this->priority = pow(2, 16) * P2P_PRIO_HOST; 
+			break;
+		case SERVER_REFLEXIVE:
+			this->priority = pow(2, 16) * P2P_PRIO_SERVER; 
+			break;
+		case PEER_REFLEXIVE:
+			this->priority = pow(2, 16) * P2P_PRIO_PEER; 
+			break;
+		case RELAYED:
+			this->priority = pow(2, 16) * P2P_PRIO_RELAY; 
+			break;
+	}
+	
+	this->priority += 65535;
+	
+	if (!host) {
+		return &this->public;
+	}
+	
+	switch(host->get_family(host))
+	{
+		case AF_INET:
+			this->family = IPv4;
+			break;
+		case AF_INET6:
+			this->family = IPv6;
+			break;
+		default:
+			// unsupported family type, we do not set the hsot (family is set to NO_FAMILY) 
+			return &this->public;
+	}
+	
+	this->endpoint = host->clone(host);
+	
+	if (base)
+	{
+		this->base = base->clone(base);
+	}
+	
+	return &this->public;
+}
+
+/**
+ * Described in header
+ */
+endpoint_notify_t *endpoint_notify_create_from_payload(notify_payload_t *notify)
+{
+	if (notify->get_notify_type(notify) != P2P_ENDPOINT)
+	{
+		return NULL;
+	}
+	
+	private_endpoint_notify_t *this = (private_endpoint_notify_t*)endpoint_notify_create();
+	chunk_t data = notify->get_notification_data(notify);
+	if (parse_notification_data(this, data) != SUCCESS)
+	{
+		destroy(this);
+		return NULL;
+	}
+	return &this->public;
+}
diff --git a/src/charon/encoding/payloads/endpoint_notify.h b/src/charon/encoding/payloads/endpoint_notify.h
new file mode 100644
index 000000000..272301d5b
--- /dev/null
+++ b/src/charon/encoding/payloads/endpoint_notify.h
@@ -0,0 +1,185 @@
+/**
+ * @file endpoint_notify.h
+ * 
+ * @brief Interface of endpoint_notify_t.
+ * 
+ */
+
+/*
+ * Copyright (C) 2007 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.
+ */
+
+
+#ifndef ENDPOINT_NOTIFY_H_
+#define ENDPOINT_NOTIFY_H_
+
+#define P2P_PRIO_HOST   255
+#define P2P_PRIO_SERVER 100
+#define P2P_PRIO_PEER   120
+#define P2P_PRIO_RELAY  0
+
+typedef enum p2p_endpoint_family_t p2p_endpoint_family_t;
+typedef enum p2p_endpoint_type_t p2p_endpoint_type_t;
+typedef struct endpoint_notify_t endpoint_notify_t;
+
+#include <encoding/payloads/notify_payload.h>
+
+enum p2p_endpoint_family_t {
+	
+	NO_FAMILY = 0,
+	
+	IPv4 = 1,
+	
+	IPv6 = 2,
+	
+	MAX_FAMILY = 3
+	
+};
+
+enum p2p_endpoint_type_t {
+	
+	NO_TYPE = 0,
+	
+	HOST = 1,
+	
+	SERVER_REFLEXIVE = 2,
+	
+	PEER_REFLEXIVE = 3,
+	
+	RELAYED = 4,
+	
+	MAX_TYPE = 5
+	
+};
+
+/**
+ * @brief Class representing a P2P_ENDPOINT notify. In fact it's not
+ * the notify per se, but the notification data of that notify that is
+ * handled with this class.
+ * 
+ * @b Constructors:
+ * - endpoint_notify_create()
+ * - endpoint_notify_create_from_host()
+ *
+ * @ingroup payloads
+ */
+struct endpoint_notify_t {
+	/**
+	 * @brief Returns the priority of this endpoint.
+	 * 
+	 * @param this		object
+	 * @return			priority
+	 */
+	u_int32_t (*get_priority) (endpoint_notify_t *this);
+	
+	/**
+	 * @brief Sets the priority of this endpoint.
+	 * 
+	 * @param this		object
+	 * @param priority	priority
+	 */
+	void (*set_priority) (endpoint_notify_t *this, u_int32_t priority);
+	
+	/**
+	 * @brief Returns the endpoint type of this endpoint.
+	 * 
+	 * @param this		object
+	 * @return			endpoint type
+	 */
+	p2p_endpoint_type_t (*get_type) (endpoint_notify_t *this);
+	
+	/**
+	 * @brief Returns the endpoint family of this endpoint.
+	 * 
+	 * @param this		object
+	 * @return			endpoint family
+	 */
+	p2p_endpoint_family_t (*get_family) (endpoint_notify_t *this);
+	
+	/**
+	 * @brief Returns the host of this endpoint.
+	 * 
+	 * @param this		object
+	 * @return			host
+	 */
+	host_t *(*get_host) (endpoint_notify_t *this);
+	
+	/**
+	 * @brief Returns the base of this endpoint.
+	 * 
+	 * If this is not a SERVER_REFLEXIVE endpoint, the returned host is the same
+	 * as the one returned by get_host.
+	 * 
+	 * @param this		object
+	 * @return			host
+	 */
+	host_t *(*get_base) (endpoint_notify_t *this);
+	
+	/**
+	 * @brief Generates a notification payload from this endpoint. 
+	 * 	
+	 * @param this 		object
+	 * @return 			built notify_payload_t
+	 */
+	notify_payload_t *(*build_notify) (endpoint_notify_t *this);
+
+	/**
+	 * @brief Clones an endpoint_notify_t object.
+	 *
+	 * @param this 	endpoint_notify_t object to clone
+	 * @return		cloned object
+	 */
+	endpoint_notify_t *(*clone) (endpoint_notify_t *this);
+	
+	/**
+	 * @brief Destroys an endpoint_notify_t object.
+	 *
+	 * @param this 	endpoint_notify_t object to destroy
+	 */
+	void (*destroy) (endpoint_notify_t *this);
+};
+
+/**
+ * @brief Creates an empty endpoint_notify_t object.
+ * 
+ * @return			created endpoint_notify_t object
+ * 
+ * @ingroup payloads
+ */
+endpoint_notify_t *endpoint_notify_create(void);
+
+
+/**
+ * @brief Creates an endpoint_notify_t object from a host.
+ * 
+ * @param type		the endpoint type
+ * @param host		host to base the notify on (gets cloned)
+ * @param base		base of the endpoint, applies only to reflexive endpoints (gets cloned)
+ * @return			created endpoint_notify_t object
+ * 
+ * @ingroup payloads
+ */
+endpoint_notify_t *endpoint_notify_create_from_host(p2p_endpoint_type_t type, host_t *host, host_t *base);
+
+/**
+ * @brief Creates an endpoint_notify_t object from a notify payload.
+ * 
+ * @param notify	the notify payload
+ * @return			- created endpoint_notify_t object
+ * 					- NULL if invalid payload
+ * @ingroup payloads
+ */
+endpoint_notify_t *endpoint_notify_create_from_payload(notify_payload_t *notify);
+
+#endif /*ENDPOINT_NOTIFY_H_*/
diff --git a/src/charon/encoding/payloads/ike_header.c b/src/charon/encoding/payloads/ike_header.c
index b1b4fbf87..7253e4f51 100644
--- a/src/charon/encoding/payloads/ike_header.c
+++ b/src/charon/encoding/payloads/ike_header.c
@@ -6,6 +6,7 @@
  */
 
 /*
+ * Copyright (C) 2007 Tobias Brunner
  * Copyright (C) 2005-2006 Martin Willi
  * Copyright (C) 2005 Jan Hutter
  * Hochschule fuer Technik Rapperswil
@@ -109,7 +110,13 @@ ENUM_NEXT(exchange_type_names, IKE_SA_INIT, INFORMATIONAL, EXCHANGE_TYPE_UNDEFIN
 	"IKE_AUTH",
 	"CREATE_CHILD_SA",
 	"INFORMATIONAL");
+#ifdef P2P
+ENUM_NEXT(exchange_type_names, P2P_CONNECT, P2P_CONNECT, INFORMATIONAL,
+	"P2P_CONNECT");
+ENUM_END(exchange_type_names, P2P_CONNECT);
+#else
 ENUM_END(exchange_type_names, INFORMATIONAL);
+#endif /* P2P */
 
 /**
  * Encoding rules to parse or generate a IKEv2-Header.
@@ -172,12 +179,23 @@ encoding_rule_t ike_header_encodings[] = {
  */
 static status_t verify(private_ike_header_t *this)
 {
-	if ((this->exchange_type < IKE_SA_INIT) || (this->exchange_type > INFORMATIONAL))
+	if ((this->exchange_type < IKE_SA_INIT) ||
+		((this->exchange_type > INFORMATIONAL)
+#ifdef P2P
+			&& (this->exchange_type != P2P_CONNECT)
+#endif /* P2P */
+		))
 	{
 		/* unsupported exchange type */
 		return FAILED;
 	}
-	if (this->initiator_spi == 0)
+
+	if (this->initiator_spi == 0
+#ifdef P2P
+		// we allow zero spi for INFORMATIONAL exchanges, to allow P2P connectivity checks
+		&& this->exchange_type != INFORMATIONAL
+#endif /* P2P */
+		)
 	{
 		/* initiator spi not set */
 		return FAILED;
diff --git a/src/charon/encoding/payloads/ike_header.h b/src/charon/encoding/payloads/ike_header.h
index 95c20f810..e80964482 100644
--- a/src/charon/encoding/payloads/ike_header.h
+++ b/src/charon/encoding/payloads/ike_header.h
@@ -6,6 +6,7 @@
  */
 
 /*
+ * Copyright (C) 2007 Tobias Brunner
  * Copyright (C) 2005-2006 Martin Willi
  * Copyright (C) 2005 Jan Hutter
  * Hochschule fuer Technik Rapperswil
@@ -70,7 +71,7 @@ enum exchange_type_t{
 	/**
 	 * EXCHANGE_TYPE_UNDEFINED. In private space, since not a official message type.
 	 */
-	EXCHANGE_TYPE_UNDEFINED = 240,
+	EXCHANGE_TYPE_UNDEFINED = 255,
 	
 	/**
 	 * IKE_SA_INIT.
@@ -90,7 +91,13 @@ enum exchange_type_t{
 	/**
 	 * INFORMATIONAL.
 	 */
-	INFORMATIONAL = 37 
+	INFORMATIONAL = 37,
+#ifdef P2P
+	/**
+	 * P2P_CONNECT
+	 */
+	P2P_CONNECT = 240
+#endif /* P2P */
 };
 
 /**
diff --git a/src/charon/encoding/payloads/notify_payload.c b/src/charon/encoding/payloads/notify_payload.c
index e27d3c68f..74a6c3197 100644
--- a/src/charon/encoding/payloads/notify_payload.c
+++ b/src/charon/encoding/payloads/notify_payload.c
@@ -6,7 +6,8 @@
  */
 
 /*
- * Copyright (C) 2006 Tobias Brunner, Daniel Roethlisberger
+ * Copyright (C) 2006-2007 Tobias Brunner
+ * Copyright (C) 2006 Daniel Roethlisberger
  * Copyright (C) 2005-2006 Martin Willi
  * Copyright (C) 2005 Jan Hutter
  * Hochschule fuer Technik Rapperswil
@@ -56,7 +57,13 @@ ENUM_NEXT(notify_type_names, SINGLE_PAIR_REQUIRED, UNEXPECTED_NAT_DETECTED, AUTH
 	"INVALID_SELECTORS",
 	"UNACCEPTABLE_ADDRESSES",
 	"UNEXPECTED_NAT_DETECTED");
+#ifdef P2P
+ENUM_NEXT(notify_type_names, P2P_CONNECT_FAILED, P2P_CONNECT_FAILED, UNEXPECTED_NAT_DETECTED,
+	"P2P_CONNECT_FAILED");
+ENUM_NEXT(notify_type_names, INITIAL_CONTACT, AUTH_LIFETIME, P2P_CONNECT_FAILED,
+#else
 ENUM_NEXT(notify_type_names, INITIAL_CONTACT, AUTH_LIFETIME, UNEXPECTED_NAT_DETECTED,
+#endif /* P2P */
 	"INITIAL_CONTACT",
 	"SET_WINDOW_SIZE",
 	"ADDITIONAL_TS_POSSIBLE",
@@ -79,7 +86,20 @@ ENUM_NEXT(notify_type_names, INITIAL_CONTACT, AUTH_LIFETIME, UNEXPECTED_NAT_DETE
 	"AUTH_LIFETIME");
 ENUM_NEXT(notify_type_names, EAP_ONLY_AUTHENTICATION, EAP_ONLY_AUTHENTICATION, AUTH_LIFETIME,
 	"EAP_ONLY_AUTHENTICATION");
+#ifdef P2P
+ENUM_NEXT(notify_type_names, USE_BEET_MODE, USE_BEET_MODE, EAP_ONLY_AUTHENTICATION,
+	"USE_BEET_MODE");
+ENUM_NEXT(notify_type_names, P2P_MEDIATION, P2P_RESPONSE, USE_BEET_MODE,
+	"P2P_MEDIATION",
+	"P2P_ENDPOINT",
+	"P2P_CALLBACK",
+	"P2P_SESSIONID",
+	"P2P_SESSIONKEY",
+	"P2P_RESPONSE");
+ENUM_END(notify_type_names, P2P_RESPONSE);
+#else
 ENUM_END(notify_type_names, EAP_ONLY_AUTHENTICATION);
+#endif /* P2P */
 
 
 ENUM_BEGIN(notify_type_short_names, UNSUPPORTED_CRITICAL_PAYLOAD, UNSUPPORTED_CRITICAL_PAYLOAD,
@@ -108,7 +128,13 @@ ENUM_NEXT(notify_type_short_names, SINGLE_PAIR_REQUIRED, UNEXPECTED_NAT_DETECTED
 	"INVAL_SEL",
 	"UNACCEPT_ADDR",
 	"UNEXPECT_NAT");
+#ifdef P2P
+ENUM_NEXT(notify_type_short_names, P2P_CONNECT_FAILED, P2P_CONNECT_FAILED, UNEXPECTED_NAT_DETECTED,
+	"P2P_CONN_FAIL");
+ENUM_NEXT(notify_type_short_names, INITIAL_CONTACT, AUTH_LIFETIME, P2P_CONNECT_FAILED,
+#else
 ENUM_NEXT(notify_type_short_names, INITIAL_CONTACT, AUTH_LIFETIME, UNEXPECTED_NAT_DETECTED,
+#endif /* P2P */
 	"INIT_CONTACT",
 	"SET_WINSIZE",
 	"ADD_TS_POSS",
@@ -131,7 +157,20 @@ ENUM_NEXT(notify_type_short_names, INITIAL_CONTACT, AUTH_LIFETIME, UNEXPECTED_NA
 	"AUTH_LFT");
 ENUM_NEXT(notify_type_short_names, EAP_ONLY_AUTHENTICATION, EAP_ONLY_AUTHENTICATION, AUTH_LIFETIME,
 	"EAP_ONLY");
+#ifdef P2P
+ENUM_NEXT(notify_type_short_names, USE_BEET_MODE, USE_BEET_MODE, EAP_ONLY_AUTHENTICATION,
+	"BEET_MODE");
+ENUM_NEXT(notify_type_short_names, P2P_MEDIATION, P2P_RESPONSE, USE_BEET_MODE,
+	"P2P_MED",
+	"P2P_EP",
+	"P2P_CB",
+	"P2P_SID",
+	"P2P_SKEY",
+	"P2P_R");
+ENUM_END(notify_type_short_names, P2P_RESPONSE);
+#else
 ENUM_END(notify_type_short_names, EAP_ONLY_AUTHENTICATION);
+#endif /* P2P */
 
 
 typedef struct private_notify_payload_t private_notify_payload_t;
@@ -303,6 +342,7 @@ static status_t verify(private_notify_payload_t *this)
 			}
 			break;
 		}
+		// FIXME: check size of P2P-NAT-T payloads
 		default:
 			/* TODO: verify */
 			break;
diff --git a/src/charon/encoding/payloads/notify_payload.h b/src/charon/encoding/payloads/notify_payload.h
index 231d0408d..4a9ad992b 100644
--- a/src/charon/encoding/payloads/notify_payload.h
+++ b/src/charon/encoding/payloads/notify_payload.h
@@ -6,7 +6,8 @@
  */
 
 /*
- * Copyright (C) 2006 Tobias Brunner, Daniel Roethlisberger
+ * Copyright (C) 2006-2007 Tobias Brunner
+ * Copyright (C) 2006 Daniel Roethlisberger
  * Copyright (C) 2005-2006 Martin Willi
  * Copyright (C) 2005 Jan Hutter
  * Hochschule fuer Technik Rapperswil
@@ -67,6 +68,10 @@ enum notify_type_t {
 	INVALID_SELECTORS = 39,
 	UNACCEPTABLE_ADDRESSES = 40,
 	UNEXPECTED_NAT_DETECTED = 41,
+#ifdef P2P
+	/* P2P-NAT-T, private use */
+	P2P_CONNECT_FAILED = 8192,
+#endif /* P2P */
 	/* notify status messages */
 	INITIAL_CONTACT = 16384,
 	SET_WINDOW_SIZE = 16385,
@@ -94,6 +99,15 @@ enum notify_type_t {
 	EAP_ONLY_AUTHENTICATION = 40960,
 	/* BEET mode, not even a draft yet. private use */
 	USE_BEET_MODE = 40961,
+#ifdef P2P
+	/* P2P-NAT-T, private use */
+	P2P_MEDIATION = 40962,
+	P2P_ENDPOINT = 40963,
+	P2P_CALLBACK = 40964,
+	P2P_SESSIONID = 40965,
+	P2P_SESSIONKEY = 40966,
+	P2P_RESPONSE = 40967
+#endif /* P2P */
 };
 
 /**
diff --git a/src/charon/encoding/payloads/payload.c b/src/charon/encoding/payloads/payload.c
index a92a3574e..2c51c60de 100644
--- a/src/charon/encoding/payloads/payload.c
+++ b/src/charon/encoding/payloads/payload.c
@@ -64,7 +64,13 @@ ENUM_NEXT(payload_type_names, SECURITY_ASSOCIATION, EXTENSIBLE_AUTHENTICATION, N
 	"ENCRYPTED",
 	"CONFIGURATION",
 	"EXTENSIBLE_AUTHENTICATION");
+#ifdef P2P
+ENUM_NEXT(payload_type_names, ID_PEER, ID_PEER, EXTENSIBLE_AUTHENTICATION,
+	"ID_PEER");
+ENUM_NEXT(payload_type_names, HEADER, UNKNOWN_PAYLOAD, ID_PEER,
+#else
 ENUM_NEXT(payload_type_names, HEADER, UNKNOWN_PAYLOAD, EXTENSIBLE_AUTHENTICATION,
+#endif /* P2P */
 	"HEADER",
 	"PROPOSAL_SUBSTRUCTURE",
 	"TRANSFORM_SUBSTRUCTURE",
@@ -94,7 +100,13 @@ ENUM_NEXT(payload_type_short_names, SECURITY_ASSOCIATION, EXTENSIBLE_AUTHENTICAT
 	"E",
 	"CP",
 	"EAP");
+#ifdef P2P
+ENUM_NEXT(payload_type_short_names, ID_PEER, ID_PEER, EXTENSIBLE_AUTHENTICATION,
+	"IDp");
+ENUM_NEXT(payload_type_short_names, HEADER, UNKNOWN_PAYLOAD, ID_PEER,
+#else
 ENUM_NEXT(payload_type_short_names, HEADER, UNKNOWN_PAYLOAD, EXTENSIBLE_AUTHENTICATION,
+#endif /* P2P */
 	"HDR",
 	"PROP",
 	"TRANS",
@@ -127,6 +139,10 @@ payload_t *payload_create(payload_type_t type)
 			return (payload_t*)id_payload_create(ID_INITIATOR);
 		case ID_RESPONDER:
 			return (payload_t*)id_payload_create(ID_RESPONDER);
+#ifdef P2P
+		case ID_PEER:
+			return (payload_t*)id_payload_create(ID_PEER);
+#endif /* P2P */
 		case AUTHENTICATION:
 			return (payload_t*)auth_payload_create();
 		case CERTIFICATE:
diff --git a/src/charon/encoding/payloads/payload.h b/src/charon/encoding/payloads/payload.h
index e00b874df..ab902d755 100644
--- a/src/charon/encoding/payloads/payload.h
+++ b/src/charon/encoding/payloads/payload.h
@@ -6,6 +6,7 @@
  */
 
 /*
+ * Copyright (C) 2007 Tobias Brunner
  * Copyright (C) 2005-2006 Martin Willi
  * Copyright (C) 2005 Jan Hutter
  * Hochschule fuer Technik Rapperswil
@@ -126,6 +127,14 @@ enum payload_type_t{
 	 */
 	EXTENSIBLE_AUTHENTICATION = 48,
 	
+#ifdef P2P	
+	/**
+	 * Identification payload for peers in P2P-NAT-T has a value from
+	 * the PRIVATE USE space. 
+	 */
+	ID_PEER = 128,
+#endif /* P2P */
+	
 	/**
 	 * Header has a value of PRIVATE USE space.
 	 * 
diff --git a/src/charon/processing/jobs/initiate_mediation_job.c b/src/charon/processing/jobs/initiate_mediation_job.c
new file mode 100644
index 000000000..d78f8a202
--- /dev/null
+++ b/src/charon/processing/jobs/initiate_mediation_job.c
@@ -0,0 +1,253 @@
+/**
+ * @file initiate_mediation_job.c
+ * 
+ * @brief Implementation of initiate_mediation_job_t.
+ * 
+ */
+
+/*
+ * Copyright (C) 2007 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 "initiate_mediation_job.h"
+
+#include <sa/ike_sa.h>
+#include <daemon.h>
+
+
+typedef struct private_initiate_mediation_job_t private_initiate_mediation_job_t;
+
+/**
+ * Private data of an initiate_mediation_job_t Object
+ */
+struct private_initiate_mediation_job_t {
+	/**
+	 * public initiate_mediation_job_t interface
+	 */
+	initiate_mediation_job_t public;
+	
+	/**
+	 * ID of the IKE_SA of the mediated connection.
+	 */
+	ike_sa_id_t *mediated_sa_id;
+	
+	/**
+	 * Child config of the CHILD_SA of the mediated connection.
+	 */
+	child_cfg_t *mediated_child;
+	
+	/**
+	 * ID of the IKE_SA of the mediation connection.
+	 */
+	ike_sa_id_t *mediation_sa_id;
+};
+
+/**
+ * Implements job_t.destroy.
+ */
+static void destroy(private_initiate_mediation_job_t *this)
+{
+	DESTROY_IF(this->mediation_sa_id);
+	DESTROY_IF(this->mediated_sa_id);
+	DESTROY_IF(this->mediated_child);
+	free(this);
+}
+
+/**
+ * Callback to handle initiation of mediation connection
+ */
+static bool initiate_callback(private_initiate_mediation_job_t *this, signal_t signal, level_t level,
+					 ike_sa_t *ike_sa, char *format, va_list args)
+{
+	if (signal == CHILD_UP_SUCCESS)
+	{
+		// mediation connection is up
+		this->mediation_sa_id = ike_sa->get_id(ike_sa);
+		this->mediation_sa_id = this->mediation_sa_id->clone(this->mediation_sa_id);
+		return FALSE;
+	}
+	return TRUE;
+}
+
+/**
+ * Implementation of job_t.execute.
+ */ 
+static void initiate(private_initiate_mediation_job_t *this)
+{//FIXME: check the logging 
+	ike_sa_t *mediated_sa, *mediation_sa;
+	peer_cfg_t *mediated_cfg, *mediation_cfg;
+	
+	mediated_sa = charon->ike_sa_manager->checkout(charon->ike_sa_manager,
+											  this->mediated_sa_id);
+	if (mediated_sa)
+	{
+		mediated_cfg = mediated_sa->get_peer_cfg(mediated_sa);
+		mediated_cfg->get_ref(mediated_cfg); // get_peer_cfg returns an internal object
+		
+		charon->ike_sa_manager->checkin(charon->ike_sa_manager, mediated_sa);
+		
+		mediation_cfg = mediated_cfg->get_mediated_by(mediated_cfg);
+		
+		if (charon->connect_manager->check_and_register(charon->connect_manager,
+				mediation_cfg->get_my_id(mediation_cfg),
+				mediated_cfg->get_peer_id(mediated_cfg),
+				this->mediated_sa_id, this->mediated_child))
+		{
+			mediated_cfg->destroy(mediated_cfg);
+			mediation_cfg->destroy(mediation_cfg);
+			charon->bus->set_sa(charon->bus, mediated_sa); // this pointer should still be valid
+			DBG1(DBG_IKE, "mediation with the same peer is already in progress, queued");
+			destroy(this);
+			return;
+		}
+		
+		mediation_cfg->get_ref(mediation_cfg); // we need an additional reference because initiate consumes one
+
+		// this function call blocks until the connection is up or failed
+		// we do not check the status, but NEED_MORE would be returned on success
+		// because the registered callback returns FALSE then
+		// this->mediation_sa_id is set in the callback
+		charon->interfaces->initiate(charon->interfaces,
+				mediation_cfg, NULL, (interface_manager_cb_t)initiate_callback, this);
+		if (!this->mediation_sa_id)
+		{
+			DBG1(DBG_JOB, "initiating mediation connection '%s' failed",
+					mediation_cfg->get_name(mediation_cfg));
+			mediation_cfg->destroy(mediation_cfg);
+			mediated_cfg->destroy(mediated_cfg);
+			charon->bus->set_sa(charon->bus, mediated_sa); // this pointer should still be valid
+			SIG(IKE_UP_FAILED, "mediation failed");
+			destroy(this);
+			return;
+		}
+		mediation_cfg->destroy(mediation_cfg);
+
+		mediation_sa = charon->ike_sa_manager->checkout(charon->ike_sa_manager,
+				this->mediation_sa_id);
+		
+		if (mediation_sa)
+		{
+			if (mediation_sa->initiate_mediation(mediation_sa, mediated_cfg) != SUCCESS)
+			{
+				DBG1(DBG_JOB, "initiating mediated connection '%s' failed",
+						mediated_cfg->get_name(mediated_cfg));
+				mediated_cfg->destroy(mediated_cfg);
+				charon->ike_sa_manager->checkin_and_destroy(charon->ike_sa_manager, mediation_sa);
+				
+				charon->bus->set_sa(charon->bus, mediated_sa); // this pointer should still be valid
+				SIG(IKE_UP_FAILED, "mediation failed");
+				destroy(this);
+				return;
+			}
+			
+			charon->ike_sa_manager->checkin(charon->ike_sa_manager, mediation_sa);
+		}
+		
+		mediated_cfg->destroy(mediated_cfg);
+	}
+	destroy(this);
+}
+
+/**
+ * Implementation of job_t.execute.
+ */ 
+static void reinitiate(private_initiate_mediation_job_t *this)
+{//FIXME: check the logging 
+	ike_sa_t *mediated_sa, *mediation_sa;
+	peer_cfg_t *mediated_cfg;
+	
+	mediated_sa = charon->ike_sa_manager->checkout(charon->ike_sa_manager,
+											  this->mediated_sa_id);
+	if (mediated_sa)
+	{
+		mediated_cfg = mediated_sa->get_peer_cfg(mediated_sa);
+		mediated_cfg->get_ref(mediated_cfg); // get_peer_cfg returns an internal object
+		charon->ike_sa_manager->checkin(charon->ike_sa_manager, mediated_sa);
+		
+		mediation_sa = charon->ike_sa_manager->checkout(charon->ike_sa_manager,
+				this->mediation_sa_id);
+		if (mediation_sa)
+		{
+			if (mediation_sa->initiate_mediation(mediation_sa, mediated_cfg) != SUCCESS)
+			{
+				DBG1(DBG_JOB, "initiating mediated connection '%s' failed",
+						mediated_cfg->get_name(mediated_cfg));
+				mediated_cfg->destroy(mediated_cfg);
+				charon->ike_sa_manager->checkin_and_destroy(charon->ike_sa_manager, mediation_sa);
+				
+				charon->bus->set_sa(charon->bus, mediated_sa); // this pointer should still be valid
+				SIG(IKE_UP_FAILED, "mediation failed");
+				destroy(this);
+				return;
+			}
+			
+			charon->ike_sa_manager->checkin(charon->ike_sa_manager, mediation_sa);
+		}
+		
+		mediated_cfg->destroy(mediated_cfg);
+	}
+	destroy(this);
+}
+
+/**
+ * Creates an empty job
+ */
+static private_initiate_mediation_job_t *initiate_mediation_job_create_empty()
+{
+	private_initiate_mediation_job_t *this = malloc_thing(private_initiate_mediation_job_t);
+	
+	/* interface functions */
+	this->public.job_interface.destroy = (void (*) (job_t *)) destroy;
+	
+	/* private variables */
+	this->mediation_sa_id = NULL;
+	this->mediated_sa_id = NULL;
+	this->mediated_child = NULL;
+
+	return this;
+}
+
+/*
+ * Described in header
+ */
+initiate_mediation_job_t *initiate_mediation_job_create(ike_sa_id_t *ike_sa_id,
+		child_cfg_t *child_cfg)
+{
+	private_initiate_mediation_job_t *this = initiate_mediation_job_create_empty();
+	
+	this->public.job_interface.execute = (void (*) (job_t *)) initiate;
+	
+	this->mediated_sa_id = ike_sa_id->clone(ike_sa_id);
+	child_cfg->get_ref(child_cfg);
+	this->mediated_child = child_cfg;
+
+	return &this->public;
+}
+
+/*
+ * Described in header
+ */
+initiate_mediation_job_t *reinitiate_mediation_job_create(ike_sa_id_t *mediation_sa_id,
+		ike_sa_id_t *mediated_sa_id)
+{
+	private_initiate_mediation_job_t *this = initiate_mediation_job_create_empty();
+	
+	this->public.job_interface.execute = (void (*) (job_t *)) reinitiate;
+	
+	this->mediation_sa_id = mediation_sa_id->clone(mediation_sa_id);
+	this->mediated_sa_id = mediated_sa_id->clone(mediated_sa_id);
+	
+	return &this->public; 
+}
diff --git a/src/charon/processing/jobs/initiate_mediation_job.h b/src/charon/processing/jobs/initiate_mediation_job.h
new file mode 100644
index 000000000..9fb3b0f7d
--- /dev/null
+++ b/src/charon/processing/jobs/initiate_mediation_job.h
@@ -0,0 +1,74 @@
+/**
+ * @file initiate_mediation_job.h
+ * 
+ * @brief Interface of initiate_mediation_job_t.
+ */
+
+/*
+ * Copyright (C) 2007 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.
+ */
+
+#ifndef INITIATE_MEDIATION_JOB_H_
+#define INITIATE_MEDIATION_JOB_H_
+
+typedef struct initiate_mediation_job_t initiate_mediation_job_t;
+
+#include <processing/jobs/job.h>
+#include <config/child_cfg.h>
+#include <sa/ike_sa_id.h>
+
+/**
+ * @brief Class representing a INITIATE_MEDIATION Job.
+ * 
+ * This job will initiate a mediation on behalf of a mediated connection.
+ * If required the mediation connection is established.
+ * 
+ * @b Constructors:
+ * - initiate_mediation_job_create()
+ * 
+ * @ingroup jobs
+ */
+struct initiate_mediation_job_t {
+	/**
+	 * implements job_t interface
+	 */
+	job_t job_interface;
+};
+
+/**
+ * @brief Creates a job of type INITIATE_MEDIATION.
+ * 
+ * @param ike_sa_id		identification of the ike_sa as ike_sa_id_t object (gets cloned)
+ * @param child_cfg		child config of the child_sa (gets cloned)
+ * @return				job object
+ * 
+ * @ingroup jobs
+ */
+initiate_mediation_job_t *initiate_mediation_job_create(ike_sa_id_t *ike_sa_id,
+		child_cfg_t *child_cfg);
+
+/**
+ * @brief Creates a special job of type INITIATE_MEDIATION that reinitiates a
+ * specific connection.
+ * 
+ * @param mediation_sa_id		identification of the mediation sa (gets cloned)
+ * @param mediated_sa_id		identification of the mediated sa (gets cloned)
+ * @return						job object
+ * 
+ * @ingroup jobs
+ */
+initiate_mediation_job_t *reinitiate_mediation_job_create(ike_sa_id_t *mediation_sa_id,
+		ike_sa_id_t *mediated_sa_id);
+
+#endif /*INITIATE_MEDIATION_JOB_H_*/
diff --git a/src/charon/processing/jobs/mediation_job.c b/src/charon/processing/jobs/mediation_job.c
new file mode 100644
index 000000000..6f5f74372
--- /dev/null
+++ b/src/charon/processing/jobs/mediation_job.c
@@ -0,0 +1,203 @@
+/**
+ * @file mediation_job.c
+ * 
+ * @brief Implementation of mediation_job_t.
+ * 
+ */
+
+/*
+ * Copyright (C) 2007 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 "mediation_job.h"
+
+#include <encoding/payloads/endpoint_notify.h>
+#include <daemon.h>
+
+
+typedef struct private_mediation_job_t private_mediation_job_t;
+
+/**
+ * Private data of an mediation_job_t Object
+ */
+struct private_mediation_job_t {
+	/**
+	 * public mediation_job_t interface
+	 */
+	mediation_job_t public;
+	
+	/**
+	 * ID of target peer.
+	 */
+	identification_t *target;
+	
+	/**
+	 * ID of the source peer.
+	 */
+	identification_t *source;
+	
+	/**
+	 * P2P_SESSIONID
+	 */
+	chunk_t session_id;
+	
+	/**
+	 * P2P_SESSIONKEY
+	 */
+	chunk_t session_key;
+	
+	/**
+	 * Submitted endpoints
+	 */
+	linked_list_t *endpoints;
+	
+	/**
+	 * Is this a callback job?
+	 */
+	bool callback;
+	
+	/**
+	 * Is this a response?
+	 */
+	bool response;
+};
+
+/**
+ * Implements job_t.destroy.
+ */
+static void destroy(private_mediation_job_t *this)
+{
+	DESTROY_IF(this->target);
+	DESTROY_IF(this->source);
+	chunk_free(&this->session_id);
+	chunk_free(&this->session_key);
+	DESTROY_OFFSET_IF(this->endpoints, offsetof(endpoint_notify_t, destroy));
+	free(this);
+}
+
+/**
+ * Implementation of job_t.execute.
+ */ 
+static void execute(private_mediation_job_t *this)
+{
+	ike_sa_id_t *target_sa_id;
+	
+	target_sa_id = charon->mediation_manager->check(charon->mediation_manager, this->target);
+	
+	if (target_sa_id)
+	{
+		ike_sa_t *target_sa = charon->ike_sa_manager->checkout(charon->ike_sa_manager,
+											  target_sa_id);
+		if (target_sa)
+		{
+			if (this->callback)
+			{
+				// send callback to a peer
+				if (target_sa->callback(target_sa, this->source) != SUCCESS)
+				{
+					DBG1(DBG_JOB, "callback for '%D' to '%D' failed",
+							this->source, this->target);
+					charon->ike_sa_manager->checkin(charon->ike_sa_manager, target_sa);
+					destroy(this);
+					return;
+				}
+			}
+			else
+			{
+				// normal mediation between two peers
+				if (target_sa->relay(target_sa, this->source, this->session_id,
+						this->session_key, this->endpoints, this->response) != SUCCESS)
+				{
+					DBG1(DBG_JOB, "mediation between '%D' and '%D' failed",
+							this->source, this->target);
+					charon->ike_sa_manager->checkin(charon->ike_sa_manager, target_sa);
+					// FIXME: notify the initiator
+					destroy(this);
+					return;
+				}
+			}
+			
+			charon->ike_sa_manager->checkin(charon->ike_sa_manager, target_sa);
+		}
+		else
+		{
+			DBG1(DBG_JOB, "mediation between '%D' and '%D' failed: "
+					"SA not found", this->source, this->target);
+		}
+	}
+	else
+	{
+		DBG1(DBG_JOB, "mediation between '%D' and '%D' failed: "
+				"peer is not online anymore", this->source, this->target);
+	}
+	destroy(this);
+}
+
+/**
+ * Creates an empty mediation job
+ */
+static private_mediation_job_t *mediation_job_create_empty()
+{
+	private_mediation_job_t *this = malloc_thing(private_mediation_job_t);
+	
+	/* interface functions */
+	this->public.job_interface.execute = (void (*) (job_t *)) execute;
+	this->public.job_interface.destroy = (void (*) (job_t *)) destroy;
+	
+	/* private variables */
+	this->target = NULL;
+	this->source = NULL;
+	this->callback = FALSE;
+	this->session_id = chunk_empty;
+	this->session_key = chunk_empty;
+	this->endpoints = NULL;
+	this->response = FALSE;
+	
+	return this;
+}
+
+/*
+ * Described in header
+ */
+mediation_job_t *mediation_job_create(identification_t *peer_id,
+		identification_t *requester, chunk_t session_id, chunk_t session_key,
+		linked_list_t *endpoints, bool response)
+{
+	private_mediation_job_t *this = mediation_job_create_empty();
+
+	this->target = peer_id->clone(peer_id);
+	this->source = requester->clone(requester);
+	this->session_id = chunk_clone(session_id);
+	this->session_key = chunk_clone(session_key);
+	this->endpoints = endpoints->clone_offset(endpoints, offsetof(endpoint_notify_t, clone));
+	this->response = response;
+	
+	return &this->public;
+}
+
+/*
+ * Described in header
+ */
+mediation_job_t *mediation_callback_job_create(identification_t *requester,
+		identification_t *peer_id)
+{
+	private_mediation_job_t *this = mediation_job_create_empty();
+	
+	this->target = requester->clone(requester);
+	this->source = peer_id->clone(peer_id);
+	this->callback = TRUE;
+	
+	return &this->public;
+}
diff --git a/src/charon/processing/jobs/mediation_job.h b/src/charon/processing/jobs/mediation_job.h
new file mode 100644
index 000000000..6130b2e27
--- /dev/null
+++ b/src/charon/processing/jobs/mediation_job.h
@@ -0,0 +1,84 @@
+/**
+ * @file mediation_job.h
+ * 
+ * @brief Interface of mediation_job_t.
+ */
+
+/*
+ * Copyright (C) 2007 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.
+ */
+
+#ifndef MEDIATION_JOB_H_
+#define MEDIATION_JOB_H_
+
+typedef struct mediation_job_t mediation_job_t;
+
+#include <library.h>
+#include <processing/jobs/job.h>
+#include <utils/identification.h>
+#include <utils/linked_list.h>
+
+/**
+ * @brief Class representing a MEDIATION Job.
+ * 
+ * This job handles the mediation on the mediation server.
+ * 
+ * @b Constructors:
+ * - mediation_job_create()
+ * 
+ * @ingroup jobs
+ */
+struct mediation_job_t {
+	/**
+	 * implements job_t interface
+	 */
+	job_t job_interface;
+};
+
+/**
+ * @brief Creates a job of type MEDIATION.
+ * 
+ * Parameters get cloned.
+ * 
+ * @param peer_id		ID of the requested peer
+ * @param requester		ID of the requesting peer
+ * @param session_id	content of P2P_SESSIONID (could be NULL)
+ * @param session_key	content of P2P_SESSIONKEY
+ * @param endpoints		list of submitted endpoints
+ * @param response		TRUE if this is a response
+ * @return				job object
+ * 
+ * @ingroup jobs
+ */
+mediation_job_t *mediation_job_create(identification_t *peer_id,
+		identification_t *requester, chunk_t session_id, chunk_t session_key,
+		linked_list_t *endpoints, bool response);
+
+
+/**
+ * @brief Creates a special job of type MEDIATION that is used to send a callback
+ * notification to a peer.
+ * 
+ * Parameters get cloned.
+ * 
+ * @param requester		ID of the waiting peer
+ * @param peer_id		ID of the requested peer
+ * @return				job object
+ * 
+ * @ingroup jobs
+ */
+mediation_job_t *mediation_callback_job_create(identification_t *requester,
+		identification_t *peer_id);
+
+#endif /*MEDIATION_JOB_H_*/
diff --git a/src/charon/processing/jobs/process_message_job.c b/src/charon/processing/jobs/process_message_job.c
index 6a0921248..ec2e7735d 100644
--- a/src/charon/processing/jobs/process_message_job.c
+++ b/src/charon/processing/jobs/process_message_job.c
@@ -59,6 +59,22 @@ static void execute(private_process_message_job_t *this)
 {
 	ike_sa_t *ike_sa;
 	
+#ifdef P2P
+	// if this is an unencrypted INFORMATIONAL exchange it is likely a 
+	// connectivity check
+	if (this->message->get_exchange_type(this->message) == INFORMATIONAL &&
+		this->message->get_first_payload_type(this->message) != ENCRYPTED)
+	{
+		// theoretically this could also be an error message see RFC 4306, section 1.5.
+		DBG1(DBG_NET, "received unencrypted informational: from %#H to %#H",
+			 this->message->get_source(this->message),
+			 this->message->get_destination(this->message));
+		charon->connect_manager->process_check(charon->connect_manager, this->message);
+		destroy(this);
+		return;
+	}
+#endif /* P2P */
+	
 	ike_sa = charon->ike_sa_manager->checkout_by_message(charon->ike_sa_manager,
 														 this->message);
 	if (ike_sa)
diff --git a/src/charon/sa/connect_manager.c b/src/charon/sa/connect_manager.c
new file mode 100644
index 000000000..d583e01bb
--- /dev/null
+++ b/src/charon/sa/connect_manager.c
@@ -0,0 +1,1615 @@
+/**
+ * @file connect_manager.c
+ *
+ * @brief Implementation of connect_manager_t.
+ *
+ */
+
+/*
+ * Copyright (C) 2007 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 "connect_manager.h"
+
+#include <pthread.h>
+#include <math.h>
+
+#include <daemon.h>
+#include <utils/linked_list.h>
+
+#include <processing/jobs/callback_job.h>
+#include <processing/jobs/initiate_mediation_job.h>
+#include <encoding/payloads/endpoint_notify.h>
+
+// base timeout
+// the sending interval is P2P_INTERVAL * active checklists (N)
+// retransmission timeout is P2P_INTERVAL * N * checks in waiting state (NW)
+#define P2P_INTERVAL 20 // 20 ms
+// min retransmission timeout (RTO is P2P_INTERVAL * N * checks in waiting state)
+#define P2P_RTO_MIN 100 // 100 ms
+// max number of retransmissions (+ the initial check)
+#define P2P_MAX_RETRANS 2
+
+
+typedef struct private_connect_manager_t private_connect_manager_t;
+
+/**
+ * Additional private members of connect_manager_t.
+ */
+struct private_connect_manager_t {
+	/**
+	 * Public interface of connect_manager_t.
+	 */
+	 connect_manager_t public;
+	
+	 /**
+	  * Lock for exclusivly accessing the manager.
+	  */
+	 pthread_mutex_t mutex;
+	 
+	 /**
+	  * Hasher to generate signatures
+	  */
+	 hasher_t *hasher;
+	 
+	 /**
+	  * Linked list with initiated mediated connections
+	  */
+	 linked_list_t *initiated;
+	 
+	 /**
+	  * Linked list with checklists (hash table with session ID as key would be better).
+	  */
+	 linked_list_t *checklists;
+};
+
+typedef enum check_state_t check_state_t;
+
+enum check_state_t {
+	CHECK_NONE,
+	CHECK_WAITING,
+	CHECK_IN_PROGRESS,
+	CHECK_SUCCEEDED,
+	CHECK_FAILED
+};
+
+typedef struct endpoint_pair_t endpoint_pair_t;
+
+/**
+ * An entry in the check list.
+ */
+struct endpoint_pair_t {
+	/** pair id */
+	u_int32_t id;
+	
+	/** priority */
+	u_int64_t priority;
+	
+	/** local endpoint */
+    host_t *local;
+    
+    /** remote endpoint */
+    host_t *remote;
+    
+    /** state */
+    check_state_t state;
+    
+    /** number of retransmissions */
+    u_int32_t retransmitted;
+    
+    /** the generated packet */
+    packet_t *packet;
+};
+
+/**
+ * Destroys an endpoint pair
+ */
+static void endpoint_pair_destroy(endpoint_pair_t *this)
+{
+	DESTROY_IF(this->local);
+    DESTROY_IF(this->remote);
+    DESTROY_IF(this->packet);
+	free(this);
+}
+
+/**
+ * Creates a new entry for the list.
+ */
+static endpoint_pair_t *endpoint_pair_create(endpoint_notify_t *initiator,
+		endpoint_notify_t *responder, bool initiator_is_local)
+{
+	endpoint_pair_t *this = malloc_thing(endpoint_pair_t);
+	
+	this->id = 0;
+	
+	u_int32_t pi = initiator->get_priority(initiator);
+	u_int32_t pr = responder->get_priority(responder);
+	this->priority = pow(2, 32) * min(pi, pr) + 2 * max(pi, pr) + (pi > pr ? 1 : 0);
+	
+	this->local = initiator_is_local ? initiator->get_base(initiator) : responder->get_base(responder);
+	this->local = this->local->clone(this->local);
+	this->remote = initiator_is_local ? responder->get_host(responder) : initiator->get_host(initiator);
+	this->remote = this->remote->clone(this->remote);
+	
+	this->state = CHECK_WAITING;
+	this->retransmitted = 0;
+	this->packet = NULL;
+    
+	return this;
+}
+
+
+typedef struct check_list_t check_list_t;
+
+/**
+ * An entry in the linked list.
+ */
+struct check_list_t {
+	
+	struct {
+		/** initiator's id */
+		identification_t *id;
+		
+		/** initiator's key */
+		chunk_t key;
+		
+		/** initiator's endpoints */
+		linked_list_t *endpoints;
+	} initiator;
+	
+	struct {
+		/** responder's id */
+		identification_t *id;
+		
+		/** responder's key */
+		chunk_t key;
+		
+		/** responder's endpoints */
+		linked_list_t *endpoints;
+	} responder;
+	
+	/** session id */
+	chunk_t session_id;
+	
+    /** list of endpoint pairs */
+    linked_list_t *pairs;
+    
+    /** pairs queued for triggered checks */
+    linked_list_t *triggered;
+    
+    /** state */
+    check_state_t state;
+    
+    /** TRUE if this is the initiator */
+	bool is_initiator;
+	
+};
+
+/**
+ * Destroys a checklist
+ */
+static void check_list_destroy(check_list_t *this)
+{
+	DESTROY_IF(this->initiator.id);
+	DESTROY_IF(this->responder.id);
+	
+	chunk_free(&this->session_id);
+	chunk_free(&this->initiator.key);
+	chunk_free(&this->responder.key);
+	
+	DESTROY_OFFSET_IF(this->initiator.endpoints, offsetof(endpoint_notify_t, destroy));
+	DESTROY_OFFSET_IF(this->responder.endpoints, offsetof(endpoint_notify_t, destroy));
+	
+	DESTROY_FUNCTION_IF(this->pairs, (void*)endpoint_pair_destroy);
+	DESTROY_IF(this->triggered); // this list contains some of the same elements as contained in this->pairs
+	
+	free(this);
+}
+
+/**
+ * Creates a new checklist
+ */
+static check_list_t *check_list_create(identification_t *initiator, identification_t *responder,
+		chunk_t session_id, chunk_t initiator_key, linked_list_t *initiator_endpoints,
+		bool is_initiator)
+{
+	check_list_t *this = malloc_thing(check_list_t);
+	
+	this->session_id = chunk_clone(session_id);
+	
+	this->initiator.id = initiator->clone(initiator);
+	this->initiator.key = chunk_clone(initiator_key);
+	this->initiator.endpoints = initiator_endpoints->clone_offset(initiator_endpoints, offsetof(endpoint_notify_t, clone));
+	
+	this->responder.id = responder->clone(responder);
+	this->responder.key = chunk_empty;
+    this->responder.endpoints = NULL;
+    
+    this->pairs = linked_list_create();
+    this->triggered = linked_list_create();
+    this->state = CHECK_NONE;
+    this->is_initiator = is_initiator;
+    
+	return this;
+}
+
+
+typedef struct waiting_sa_t waiting_sa_t;
+
+/**
+ * For an initiator, the data stored about a waiting mediated sa
+ */
+struct waiting_sa_t {
+	/** ike sa id */
+	ike_sa_id_t *ike_sa_id;
+	
+	/** list of child_cfg_t */
+	linked_list_t *childs;
+};
+
+/**
+ * Destroys a queued mediated sa
+ */
+static void waiting_sa_destroy(waiting_sa_t *this)
+{
+	DESTROY_IF(this->ike_sa_id);
+	this->childs->destroy_offset(this->childs, offsetof(child_cfg_t, destroy));
+	free(this);
+}
+
+/**
+ * Creates a new mediated sa object
+ */
+static waiting_sa_t *waiting_sa_create(ike_sa_id_t *ike_sa_id)
+{
+	waiting_sa_t *this = malloc_thing(waiting_sa_t);
+	
+	this->ike_sa_id = ike_sa_id->clone(ike_sa_id);
+	this->childs = linked_list_create();
+    
+	return this;
+}
+
+typedef struct initiated_t initiated_t;
+
+/**
+ * For an initiator, the data stored about initiated mediation connections
+ */
+struct initiated_t {
+	/** my id */
+	identification_t *id;
+	
+	/** peer id */
+	identification_t *peer_id;
+	
+	/** list of mediated sas */
+	linked_list_t *mediated;
+};
+
+/**
+ * Destroys a queued initiation
+ */
+static void initiated_destroy(initiated_t *this)
+{
+	DESTROY_IF(this->id);
+	DESTROY_IF(this->peer_id);
+	this->mediated->destroy_function(this->mediated, (void*)waiting_sa_destroy);
+	free(this);
+}
+
+/**
+ * Creates a queued initiation
+ */
+static initiated_t *initiated_create(identification_t *id, identification_t *peer_id)
+{
+	initiated_t *this = malloc_thing(initiated_t);
+	
+	this->id = id->clone(id);
+	this->peer_id = peer_id->clone(peer_id);
+	this->mediated = linked_list_create();
+    
+	return this;
+}
+
+
+typedef struct check_t check_t;
+
+/**
+ * Data exchanged in a connectivity check
+ */
+struct check_t {
+	/** message id */
+	u_int32_t mid;
+	
+	/** source of the connectivity check */
+	host_t *src;
+	
+	/** destination of the connectivity check */
+	host_t *dst;
+	
+	/** session id */
+	chunk_t session_id;
+	
+	/** endpoint */
+	endpoint_notify_t *endpoint;
+	
+	/** raw endpoint payload (to verify the signature) */
+	chunk_t endpoint_raw;
+	
+    /** cookie */
+    chunk_t cookie;
+};
+
+/**
+ * Destroys a connectivity check
+ */
+static void check_destroy(check_t *this)
+{
+	chunk_free(&this->session_id);
+	chunk_free(&this->endpoint_raw);
+	chunk_free(&this->cookie);
+	DESTROY_IF(this->endpoint);
+	free(this);
+}
+
+/**
+ * Creates a new connectivity check
+ */
+static check_t *check_create()
+{
+	check_t *this = malloc_thing(check_t);
+	
+	this->session_id = chunk_empty;
+	this->cookie = chunk_empty;
+	this->endpoint_raw = chunk_empty;
+	this->endpoint = NULL;
+	
+	this->mid = 0;
+	
+	return this;
+}
+
+typedef struct sender_data_t sender_data_t;
+
+/**
+ * Data required by the sender
+ */
+struct sender_data_t {
+	/** connect manager */
+	private_connect_manager_t *connect_manager;
+	
+	/** session id */
+	chunk_t session_id;
+};
+
+/**
+ * Destroys a sender data object
+ */
+static void sender_data_destroy(sender_data_t *this)
+{
+	chunk_free(&this->session_id);
+	free(this);
+}
+
+/**
+ * Creates a new sender data object
+ */
+static sender_data_t *sender_data_create(private_connect_manager_t *connect_manager, chunk_t session_id)
+{
+	sender_data_t *this = malloc_thing(sender_data_t);	
+	this->connect_manager = connect_manager;
+	this->session_id = session_id;
+	return this;
+}
+
+typedef struct retransmit_data_t retransmit_data_t;
+
+/**
+ * Data required by the retransmission job
+ */
+struct retransmit_data_t {
+	/** connect manager */
+	private_connect_manager_t *connect_manager;
+	
+	/** session id */
+	chunk_t session_id;
+	
+	/** message (pair) id */
+	u_int32_t mid;
+};
+
+/**
+ * Destroys a retransmission data object
+ */
+static void retransmit_data_destroy(retransmit_data_t *this)
+{
+	chunk_free(&this->session_id);
+	free(this);
+}
+
+/**
+ * Creates a new retransmission data object
+ */
+static retransmit_data_t *retransmit_data_create(private_connect_manager_t *connect_manager,
+		chunk_t session_id, u_int32_t mid)
+{
+	retransmit_data_t *this = malloc_thing(retransmit_data_t);
+	
+	this->connect_manager = connect_manager;
+	this->session_id = session_id;
+	this->mid = mid;
+
+	return this;
+}
+
+typedef struct initiate_data_t initiate_data_t;
+
+/**
+ * Data required by the initiate mediated
+ */
+struct initiate_data_t {
+	/** checklist */
+	check_list_t *checklist;
+	
+	/** waiting mediated connections */
+	initiated_t *initiated;
+};
+
+/**
+ * Destroys a initiate data object
+ */
+static void initiate_data_destroy(initiate_data_t *this)
+{
+	check_list_destroy(this->checklist);
+	initiated_destroy(this->initiated);
+	free(this);
+}
+
+/**
+ * Creates a new initiate data object
+ */
+static initiate_data_t *initiate_data_create(check_list_t *checklist, initiated_t *initiated)
+{
+	initiate_data_t *this = malloc_thing(initiate_data_t);
+	
+	this->checklist = checklist;
+	this->initiated = initiated;
+
+	return this;
+}
+
+// -----------------------------------------------------------------------------
+
+/**
+ * Find an initiated connection by the peers' ids
+ */
+static status_t get_initiated_by_ids(private_connect_manager_t *this,
+		identification_t *id, identification_t *peer_id, initiated_t **initiated)
+{
+	iterator_t *iterator;
+	initiated_t *current;
+	status_t status = NOT_FOUND;
+	
+	iterator = this->initiated->create_iterator(this->initiated, TRUE);
+	while (iterator->iterate(iterator, (void**)&current))
+	{
+		if (id->equals(id, current->id) && peer_id->equals(peer_id, current->peer_id))
+		{
+			if (initiated)
+			{
+				*initiated = current;
+			}
+			status = SUCCESS;
+			break;
+		}
+	}
+	iterator->destroy(iterator);
+
+	return status;
+}
+
+/**
+ * Removes data about initiated connections
+ */
+static void remove_initiated(private_connect_manager_t *this, initiated_t *initiated)
+{
+	iterator_t *iterator;
+	initiated_t *current;
+	
+	iterator = this->initiated->create_iterator(this->initiated, TRUE);
+	while (iterator->iterate(iterator, (void**)&current))
+	{
+		if (current == initiated)
+		{
+			iterator->remove(iterator);
+			break;
+		}
+	}
+	iterator->destroy(iterator);
+}
+
+/**
+ * Finds a waiting sa
+ */
+static status_t get_waiting_sa(initiated_t *initiated, ike_sa_id_t *ike_sa_id, waiting_sa_t **waiting_sa)
+{
+	iterator_t *iterator;
+	waiting_sa_t *current;
+	status_t status = NOT_FOUND;
+	
+	iterator = initiated->mediated->create_iterator(initiated->mediated, TRUE);
+	while (iterator->iterate(iterator, (void**)&current))
+	{
+		if (ike_sa_id->equals(ike_sa_id, current->ike_sa_id))
+		{
+			if (waiting_sa)
+			{
+				*waiting_sa = current;
+			}
+			status = SUCCESS;
+			break;
+		}
+	}
+	iterator->destroy(iterator);
+
+	return status;
+}
+
+/**
+ * Find the checklist with a specific session ID
+ */
+static status_t get_checklist_by_id(private_connect_manager_t *this,
+		chunk_t session_id, check_list_t **check_list)
+{
+	iterator_t *iterator;
+	check_list_t *current;
+	status_t status = NOT_FOUND;
+	
+	iterator = this->checklists->create_iterator(this->checklists, TRUE);
+	while (iterator->iterate(iterator, (void**)&current))
+	{
+		if (chunk_equals(session_id, current->session_id))
+		{
+			if (check_list)
+			{
+				*check_list = current;
+			}
+			status = SUCCESS;
+			break;
+		}
+	}
+	iterator->destroy(iterator);
+
+	return status;
+}
+
+/**
+ * Removes a checklist
+ */
+static void remove_checklist(private_connect_manager_t *this, check_list_t *checklist)
+{
+	iterator_t *iterator;
+	check_list_t *current;
+	
+	iterator = this->checklists->create_iterator(this->checklists, TRUE);
+	while (iterator->iterate(iterator, (void**)&current))
+	{
+		if (current == checklist)
+		{
+			iterator->remove(iterator);
+			break;
+		}
+	}
+	iterator->destroy(iterator);
+}
+
+/**
+ * Checks if a list of endpoint_notify_t contains a certain host_t
+ */
+static status_t endpoints_contain(linked_list_t *endpoints, host_t *host, endpoint_notify_t **endpoint)
+{
+	iterator_t *iterator;
+	endpoint_notify_t *current;
+	status_t status = NOT_FOUND;
+	
+	iterator = endpoints->create_iterator(endpoints, TRUE);
+	while (iterator->iterate(iterator, (void**)&current))
+	{
+		if (host->equals(host, current->get_host(current)))
+		{
+			if (endpoint)
+			{
+				*endpoint = current;
+			}
+			status = SUCCESS;
+			break;
+		}
+	}
+	iterator->destroy(iterator);
+	
+	return status;
+}
+
+// -----------------------------------------------------------------------------
+
+
+/**
+ * Updates the state of the whole checklist
+ */
+static void update_checklist_state(check_list_t *checklist)
+{
+	iterator_t *iterator;
+	endpoint_pair_t *current;
+	bool in_progress = FALSE, succeeded = FALSE;
+
+	iterator = checklist->pairs->create_iterator(checklist->pairs, TRUE);
+	while (iterator->iterate(iterator, (void**)&current))
+	{
+		switch(current->state)
+		{
+			case CHECK_WAITING:
+				// at least one is still waiting -> checklist remains in waiting state
+				iterator->destroy(iterator);
+				return;
+			case CHECK_IN_PROGRESS:
+				in_progress = TRUE;
+				break;
+			case CHECK_SUCCEEDED:
+				succeeded = TRUE;
+				break;
+		}
+	}
+	iterator->destroy(iterator);
+	
+	if (in_progress)
+	{
+		checklist->state = CHECK_IN_PROGRESS;
+	}
+	else if (succeeded)
+	{
+		checklist->state = CHECK_SUCCEEDED;
+	}
+	else
+	{
+		checklist->state = CHECK_FAILED;
+	}
+}
+
+/**
+ * Inserts an endpoint pair into the list of pairs ordered by priority (high to low)
+ */
+static void insert_pair_by_priority(linked_list_t *pairs, endpoint_pair_t *pair)
+{
+	iterator_t *iterator;
+	endpoint_pair_t *current;
+	bool inserted = FALSE;
+	
+	iterator = pairs->create_iterator(pairs, TRUE);
+	while (iterator->iterate(iterator, (void**)&current))
+	{
+		if (current->priority < pair->priority)
+		{
+			iterator->insert_before(iterator, pair);
+			inserted = TRUE;
+			break;
+		}
+	}
+	iterator->destroy(iterator);
+	
+	if (!inserted)
+	{
+		pairs->insert_last(pairs, pair);
+	}
+}
+
+/**
+ * Searches a list of endpoint_pair_t for a pair with specific host_ts
+ */
+static status_t get_pair_by_hosts(linked_list_t *pairs, host_t *local, host_t *remote, endpoint_pair_t **pair)
+{
+	iterator_t *iterator;
+	endpoint_pair_t *current;
+	status_t status = NOT_FOUND;
+	
+	iterator = pairs->create_iterator(pairs, TRUE);
+	while (iterator->iterate(iterator, (void**)&current))
+	{
+		if (local->equals(local, current->local) &&
+				remote->equals(remote, current->remote))
+		{
+			if (pair)
+			{
+				*pair = current;
+			}
+			status = SUCCESS;
+			break;
+		}
+	}
+	iterator->destroy(iterator);
+	
+	return status;
+}
+
+/**
+ * Searches for a pair with a specific id
+ */
+static status_t get_pair_by_id(check_list_t *checklist, u_int32_t id, endpoint_pair_t **pair)
+{
+	iterator_t *iterator;
+	endpoint_pair_t *current;
+	status_t status = NOT_FOUND;
+	
+	iterator = checklist->pairs->create_iterator(checklist->pairs, TRUE);
+	while (iterator->iterate(iterator, (void**)&current))
+	{
+		if (current->id == id)
+		{
+			if (pair)
+			{
+				*pair = current;
+			}
+			status = SUCCESS;
+			break;
+		}
+	}
+	iterator->destroy(iterator);
+	
+	return status;
+}
+
+/**
+ * Returns the best pair of state CHECK_SUCCEEDED from a checklist. 
+ */
+static status_t get_best_valid_pair(check_list_t *checklist, endpoint_pair_t **pair)
+{
+	iterator_t *iterator;
+	endpoint_pair_t *current;
+	status_t status = NOT_FOUND;
+	
+	iterator = checklist->pairs->create_iterator(checklist->pairs, TRUE);
+	while (iterator->iterate(iterator, (void**)&current))
+	{
+		if (current->state == CHECK_SUCCEEDED)
+		{
+			if (pair)
+			{
+				*pair = current;
+			}
+			status = SUCCESS;
+			break;
+		}
+	}
+	iterator->destroy(iterator);
+	
+	return status;
+}
+
+/**
+ * Returns and removes the first triggered pair in state CHECK_WAITING. 
+ */
+static status_t get_triggered_pair(check_list_t *checklist, endpoint_pair_t **pair)
+{
+	iterator_t *iterator;
+	endpoint_pair_t *current;
+	status_t status = NOT_FOUND;
+	
+	iterator = checklist->triggered->create_iterator(checklist->triggered, TRUE);
+	while (iterator->iterate(iterator, (void**)&current))
+	{
+		iterator->remove(iterator);
+		
+		if (current->state == CHECK_WAITING)
+		{
+			if (pair)
+			{
+				*pair = current;
+			}
+			status = SUCCESS;
+			break;
+		}
+	}
+	iterator->destroy(iterator);
+	
+	return status;
+}
+
+/**
+ * Prunes identical pairs with lower priority from the list
+ * Note: this function also numbers the remaining pairs serially
+ */
+static void prune_pairs(linked_list_t *pairs)
+{
+	iterator_t *iterator, *search;
+	endpoint_pair_t *current, *other;
+	bool inserted = FALSE;
+	u_int32_t id = 0;
+	
+	iterator = pairs->create_iterator(pairs, TRUE);
+	search = pairs->create_iterator(pairs, TRUE);
+	while (iterator->iterate(iterator, (void**)&current))
+	{
+		current->id = ++id;
+		
+		while (search->iterate(search, (void**)&other))
+		{
+			if (current == other)
+			{
+				continue;
+			}
+			
+			if (current->local->equals(current->local, other->local) &&
+					current->remote->equals(current->remote, other->remote))
+			{
+				// since the list of pairs is sorted by priority in descending
+				// order, and we iterate the list from the beginning, we are
+				// sure that the priority of 'other' is lower than that of
+				// 'current', remove it
+				DBG1(DBG_IKE, "pruning endpoint pair %H - %H with priority %d",
+						other->local, other->remote, other->priority);
+				search->remove(search);
+				endpoint_pair_destroy(other);
+			}
+		}
+		search->reset(search);
+	}
+	search->destroy(search);
+	iterator->destroy(iterator);
+}
+
+/**
+ * Builds a list of endpoint pairs
+ */
+static void build_pairs(check_list_t *checklist)
+{
+	iterator_t *iterator_i, *iterator_r;
+	endpoint_notify_t *initiator, *responder;
+	
+	iterator_i = checklist->initiator.endpoints->create_iterator(checklist->initiator.endpoints, TRUE);
+	while (iterator_i->iterate(iterator_i, (void**)&initiator))
+	{
+		iterator_r = checklist->responder.endpoints->create_iterator(checklist->responder.endpoints, TRUE);
+		while (iterator_r->iterate(iterator_r, (void**)&responder))
+		{
+			if (initiator->get_family(initiator) != responder->get_family(responder))
+			{
+				continue;
+			}
+			
+			insert_pair_by_priority(checklist->pairs,
+					endpoint_pair_create(initiator, responder, checklist->is_initiator));
+		}
+		iterator_r->destroy(iterator_r);
+	}
+	iterator_i->destroy(iterator_i);
+
+	prune_pairs(checklist->pairs);
+}
+
+// -----------------------------------------------------------------------------
+
+/**
+ * Processes the payloads of a connectivity check and returns the extracted data
+ */
+static status_t process_payloads(message_t *message, check_t *check)
+{
+	iterator_t *iterator;
+	payload_t *payload;
+
+	iterator = message->get_payload_iterator(message);
+	while (iterator->iterate(iterator, (void**)&payload))
+	{
+		if (payload->get_type(payload) != NOTIFY)
+		{
+			DBG1(DBG_IKE, "ignoring payload of type '%N' while processing "
+					"connectivity check", payload_type_names, payload->get_type(payload));
+			continue;
+		}
+		
+		notify_payload_t *notify = (notify_payload_t*)payload;
+		
+		switch (notify->get_notify_type(notify))
+		{
+			case P2P_ENDPOINT:
+			{
+				if (check->endpoint)
+				{
+					DBG1(DBG_IKE, "connectivity check contains multiple P2P_ENDPOINT notifies");
+					break;
+				}
+				
+				endpoint_notify_t *endpoint = endpoint_notify_create_from_payload(notify);
+				if (!endpoint)
+				{
+					DBG1(DBG_IKE, "received invalid P2P_ENDPOINT notify");
+					break;
+				}
+				check->endpoint = endpoint;
+				check->endpoint_raw = chunk_clone(notify->get_notification_data(notify));
+				DBG3(DBG_IKE, "received P2P_ENDPOINT notify");
+				break;
+			}
+			case P2P_SESSIONID:
+			{
+				if (check->session_id.ptr)
+				{
+					DBG1(DBG_IKE, "connectivity check contains multiple P2P_SESSIONID notifies");
+					break;
+				}
+				check->session_id = chunk_clone(notify->get_notification_data(notify));
+				DBG3(DBG_IKE, "received p2p_sessionid %B", &check->session_id);
+				break;
+			}
+			case COOKIE:
+			{
+				if (check->cookie.ptr)
+				{
+					DBG1(DBG_IKE, "connectivity check contains multiple COOKIE notifies");
+					break;
+				}
+				check->cookie = chunk_clone(notify->get_notification_data(notify));
+				DBG3(DBG_IKE, "received cookie %B", &check->cookie);
+				break;
+			}
+			default:
+				break;
+		}
+	}
+	iterator->destroy(iterator);
+	
+	if (!check->session_id.ptr || !check->endpoint || !check->cookie.ptr)
+	{
+		DBG1(DBG_IKE, "at least one payload was missing from the connectivity check");
+		return FAILED;
+	}
+	
+	return SUCCESS;
+}
+
+/**
+ * Builds the signature for a connectivity check
+ */
+static chunk_t build_signature(private_connect_manager_t *this, 
+		check_list_t *checklist, check_t *check, bool outbound)
+{
+	chunk_t mid_chunk, key_chunk, sig_chunk;
+	chunk_t sig_hash;
+	
+	mid_chunk = chunk_from_thing(check->mid);
+	
+	key_chunk = (checklist->is_initiator && outbound) || (!checklist->is_initiator && !outbound)
+					? checklist->initiator.key : checklist->responder.key;
+	
+	/* signature = SHA1( MID | P2P_SESSIONID | P2P_ENDPOINT | P2P_SESSIONKEY ) */
+	sig_chunk = chunk_cat("cccc", mid_chunk, check->session_id, check->endpoint_raw, key_chunk);
+	this->hasher->allocate_hash(this->hasher, sig_chunk, &sig_hash);
+	DBG3(DBG_IKE, "sig_chunk %B", &sig_chunk);
+	DBG3(DBG_IKE, "sig_hash %B", &sig_hash);
+	
+	chunk_free(&sig_chunk);
+	return sig_hash;
+}
+
+// -----------------------------------------------------------------------------
+
+// forward declarations
+static void queue_retransmission(private_connect_manager_t *this, chunk_t session_id, u_int32_t mid);
+static void schedule_checks(private_connect_manager_t *this, check_list_t *checklist, u_int32_t time);
+static void finish_checks(private_connect_manager_t *this, check_list_t *checklist);
+
+/**
+ * This function is triggered for each sent check after a specific timeout
+ */
+static job_requeue_t retransmit(retransmit_data_t *data)
+{
+	private_connect_manager_t *this = data->connect_manager;
+	
+	pthread_mutex_lock(&(this->mutex));
+
+	check_list_t *checklist;
+	if (get_checklist_by_id(this, data->session_id, &checklist) != SUCCESS)
+	{
+		DBG1(DBG_IKE, "checklist with id '%B' not found, can't retransmit connectivity check",
+				&data->session_id);
+		pthread_mutex_unlock(&(this->mutex));
+		return JOB_REQUEUE_NONE;
+	}
+	
+	endpoint_pair_t *pair;
+	if (get_pair_by_id(checklist, data->mid, &pair) != SUCCESS)
+	{
+		DBG1(DBG_IKE, "pair with id '%d' not found, can't retransmit connectivity check",
+				data->mid);
+		goto retransmit_end;
+	}
+	
+	if (pair->state != CHECK_IN_PROGRESS)
+	{
+		DBG2(DBG_IKE, "pair with id '%d' is in wrong state [%d], don't retransmit the connectivity check",
+				data->mid, pair->state);
+		goto retransmit_end;
+	}
+	
+	if (++pair->retransmitted >= P2P_MAX_RETRANS)
+	{
+		DBG2(DBG_IKE, "pair with id '%d' failed after %d tries",
+				data->mid, pair->retransmitted);
+		pair->state = CHECK_FAILED;
+		goto retransmit_end;
+	}
+	
+	charon->sender->send(charon->sender, pair->packet->clone(pair->packet));
+	
+	queue_retransmission(this, checklist->session_id, pair->id);
+
+retransmit_end:
+	update_checklist_state(checklist);
+	
+	switch(checklist->state)
+	{
+		case CHECK_SUCCEEDED:
+		case CHECK_FAILED:
+			finish_checks(this, checklist);
+			break;
+	}
+	
+	pthread_mutex_unlock(&(this->mutex));
+	
+	// we reschedule it manually
+	return JOB_REQUEUE_NONE;
+}
+
+/**
+ * Queues a retransmission job
+ */
+static void queue_retransmission(private_connect_manager_t *this, chunk_t session_id, u_int32_t mid)
+{
+	retransmit_data_t *data = retransmit_data_create(this, chunk_clone(session_id), mid);
+	job_t *job = (job_t*)callback_job_create((callback_job_cb_t)retransmit, data, (callback_job_cleanup_t)retransmit_data_destroy, NULL);
+	charon->scheduler->schedule_job(charon->scheduler, (job_t*)job, P2P_RTO_MIN);
+}
+
+/**
+ * Sends a check
+ */
+static void send_check(private_connect_manager_t *this, check_list_t *checklist,
+		check_t *check, endpoint_pair_t *pair, bool request)
+{
+	message_t *message = message_create();
+	message->set_message_id(message, check->mid);
+	message->set_exchange_type(message, INFORMATIONAL);
+	message->set_request(message, request);
+	message->set_destination(message, check->dst->clone(check->dst));
+	message->set_source(message, check->src->clone(check->src));
+	
+	message->set_ike_sa_id(message, ike_sa_id_create(0, 0, request));
+
+	message->add_notify(message, FALSE, P2P_SESSIONID, check->session_id);
+	
+	notify_payload_t *endpoint = check->endpoint->build_notify(check->endpoint);
+	check->endpoint_raw = chunk_clone(endpoint->get_notification_data(endpoint));
+	message->add_payload(message, (payload_t*)endpoint);
+	
+	check->cookie = build_signature(this, checklist, check, TRUE);
+	message->add_notify(message, FALSE, COOKIE, check->cookie);
+	
+	packet_t *packet;
+	if (message->generate(message, NULL, NULL, &packet) == SUCCESS)
+	{
+		charon->sender->send(charon->sender, packet->clone(packet));
+		
+		if (request)
+		{
+			DESTROY_IF(pair->packet);
+			pair->packet = packet;
+			queue_retransmission(this, checklist->session_id, pair->id);
+		}
+		else
+		{
+			packet->destroy(packet);
+		}
+	}
+}
+
+/**
+ * Queues a triggered check
+ */
+static void queue_triggered_check(check_list_t *checklist, endpoint_pair_t *pair)
+{
+ 	pair->state = CHECK_WAITING;
+ 	checklist->triggered->insert_last(checklist->triggered, pair);
+}
+
+/**
+ * This function is triggered for each checklist at a specific interval
+ */
+static job_requeue_t sender(sender_data_t *data)
+{
+	private_connect_manager_t *this = data->connect_manager;
+
+	pthread_mutex_lock(&(this->mutex));
+
+	check_list_t *checklist;
+	if (get_checklist_by_id(this, data->session_id, &checklist) != SUCCESS)
+	{
+		DBG1(DBG_IKE, "checklist with id '%B' not found, can't send connectivity check",
+				&data->session_id);
+		pthread_mutex_unlock(&(this->mutex));
+		return JOB_REQUEUE_NONE;
+	}
+	
+	endpoint_pair_t *pair;
+	if (get_triggered_pair(checklist, &pair) != SUCCESS)
+	{
+		DBG1(DBG_IKE, "no triggered check queued, sending an ordinary check");
+		
+		iterator_t *iterator;
+		bool found_one = FALSE;
+	
+		iterator = checklist->pairs->create_iterator(checklist->pairs, TRUE);
+		while (iterator->iterate(iterator, (void**)&pair))
+		{
+			if (pair->state == CHECK_WAITING)
+			{
+				found_one = TRUE;
+				break;
+			}
+		}
+		iterator->destroy(iterator);
+	
+		if (!found_one)
+		{
+			pthread_mutex_unlock(&(this->mutex));
+			DBG1(DBG_IKE, "no pairs in waiting state, aborting");
+			return JOB_REQUEUE_NONE;
+		}
+	}
+	else
+	{
+		DBG1(DBG_IKE, "triggered check found");
+	}
+
+	check_t *check = check_create();
+	check->mid = pair->id;
+	check->src = pair->local->clone(pair->local);
+	check->dst = pair->remote->clone(pair->remote);
+	check->session_id = chunk_clone(checklist->session_id);
+	check->endpoint = endpoint_notify_create();
+	
+	pair->state = CHECK_IN_PROGRESS;
+	
+	send_check(this, checklist, check, pair, TRUE);
+	
+	check_destroy(check);
+	
+	// schedule this job again
+	u_int32_t N = this->checklists->get_count(this->checklists);
+	schedule_checks(this, checklist, P2P_INTERVAL * N);
+	
+	pthread_mutex_unlock(&(this->mutex));
+	
+	// we reschedule it manually
+	return JOB_REQUEUE_NONE;
+}
+
+/**
+ * Schedules checks for a checklist (time in ms)
+ */
+static void schedule_checks(private_connect_manager_t *this, check_list_t *checklist, u_int32_t time)
+{
+	chunk_t session_id = chunk_clone(checklist->session_id);
+	sender_data_t *data = sender_data_create(this, session_id);
+	job_t *job = (job_t*)callback_job_create((callback_job_cb_t)sender, data, (callback_job_cleanup_t)sender_data_destroy, NULL);
+	charon->scheduler->schedule_job(charon->scheduler, job, time);
+}
+
+/**
+ * Initiates waiting mediated connections
+ */
+static job_requeue_t initiate_mediated(initiate_data_t *data)
+{
+	check_list_t *checklist = data->checklist;
+	initiated_t *initiated = data->initiated;
+	
+	endpoint_pair_t *pair;
+	if (get_best_valid_pair(checklist, &pair) == SUCCESS)
+	{
+		waiting_sa_t *waiting_sa;
+		iterator_t *iterator = initiated->mediated->create_iterator(initiated->mediated, TRUE);
+		while (iterator->iterate(iterator, (void**)&waiting_sa))
+		{
+			ike_sa_t *sa = charon->ike_sa_manager->checkout(charon->ike_sa_manager, waiting_sa->ike_sa_id);
+			if (sa->initiate_mediated(sa, pair->local, pair->remote, waiting_sa->childs) != SUCCESS)
+			{
+				SIG(IKE_UP_FAILED, "establishing the mediated connection failed");
+				charon->ike_sa_manager->checkin_and_destroy(charon->ike_sa_manager, sa);
+			}
+			charon->ike_sa_manager->checkin(charon->ike_sa_manager, sa);
+		}
+		iterator->destroy(iterator);
+	}
+	else
+	{
+		// this should (can?) not happen
+	}
+}
+
+/**
+ * Finishes checks for a checklist
+ */
+static void finish_checks(private_connect_manager_t *this, check_list_t *checklist)
+{
+	if (checklist->is_initiator)
+	{
+		initiated_t *initiated;
+		if (get_initiated_by_ids(this, checklist->initiator.id,
+				checklist->responder.id, &initiated) == SUCCESS)
+		{
+			remove_checklist(this, checklist);
+			remove_initiated(this, initiated);
+			
+			initiate_data_t *data = initiate_data_create(checklist, initiated);
+			job_t *job = (job_t*)callback_job_create((callback_job_cb_t)initiate_mediated, data, (callback_job_cleanup_t)initiate_data_destroy, NULL);
+			charon->processor->queue_job(charon->processor, job);
+			return;
+		}
+		else
+		{
+			DBG1(DBG_IKE, "there is no mediated connection waiting between '%D' "
+					"and '%D'", checklist->initiator.id, checklist->responder.id);
+		}
+	}
+	
+	//remove_checklist(this, checklist);
+	//check_list_destroy(checklist);
+	// FIXME: we should do this ^^^ after a specific timeout on the responder side
+}
+
+/**
+ * Process the response to one of our requests
+ */
+static void process_response(private_connect_manager_t *this, check_t *check,
+		check_list_t *checklist)
+{
+	endpoint_pair_t *pair;
+	if (get_pair_by_id(checklist, check->mid, &pair) == SUCCESS)
+	{
+		if (pair->local->equals(pair->local, check->dst) &&
+				pair->remote->equals(pair->remote, check->src))
+		{
+			DBG1(DBG_IKE, "endpoint pair '%d' is valid: '%#H' - '%#H'", pair->id,
+					pair->local, pair->remote);
+			pair->state = CHECK_SUCCEEDED;
+		}
+		
+		linked_list_t *local_endpoints = checklist->is_initiator ?
+			checklist->initiator.endpoints : checklist->responder.endpoints;
+		
+		endpoint_notify_t *local_endpoint;
+		if (endpoints_contain(local_endpoints,
+				check->endpoint->get_host(check->endpoint), &local_endpoint) != SUCCESS)
+		{
+			local_endpoint = endpoint_notify_create_from_host(PEER_REFLEXIVE,
+					check->endpoint->get_host(check->endpoint), pair->local);
+			local_endpoint->set_priority(local_endpoint, check->endpoint->get_priority(check->endpoint));
+			local_endpoints->insert_last(local_endpoints, local_endpoint);
+		}
+		
+		update_checklist_state(checklist);
+		
+		switch(checklist->state)
+		{
+			case CHECK_SUCCEEDED:
+			case CHECK_FAILED:
+				finish_checks(this, checklist);
+				break;
+		}
+	}
+	else
+	{
+		DBG1(DBG_IKE, "pair with id '%d' not found", check->mid);
+	}
+}
+
+static void process_request(private_connect_manager_t *this, check_t *check,
+		check_list_t *checklist)
+{
+	linked_list_t *remote_endpoints = checklist->is_initiator ?
+				checklist->responder.endpoints : checklist->initiator.endpoints;
+		
+	endpoint_notify_t *peer_reflexive, *remote_endpoint;
+	peer_reflexive = endpoint_notify_create_from_host(PEER_REFLEXIVE, check->src, NULL);
+	peer_reflexive->set_priority(peer_reflexive, check->endpoint->get_priority(check->endpoint));
+		
+	if (endpoints_contain(remote_endpoints, check->src, &remote_endpoint) != SUCCESS)
+	{
+		remote_endpoint = peer_reflexive->clone(peer_reflexive);
+		remote_endpoints->insert_last(remote_endpoints, remote_endpoint);
+	}
+	
+	endpoint_pair_t *pair;
+	if (get_pair_by_hosts(checklist->pairs, check->dst, check->src, &pair) == SUCCESS)
+	{
+		switch(pair->state)
+		{
+			case CHECK_IN_PROGRESS:
+				pair->retransmitted = P2P_MAX_RETRANS; // prevent retransmissions
+				// FIXME: we should wait to the next rto to send the triggered check
+				// fall-through
+			case CHECK_WAITING:
+			case CHECK_FAILED:
+				queue_triggered_check(checklist, pair);
+				break;
+			case CHECK_SUCCEEDED:
+			default:
+				// do nothing
+				break;
+		}
+	}
+	else
+	{
+		endpoint_notify_t *local_endpoint = endpoint_notify_create_from_host(HOST, check->dst, NULL);
+		
+		endpoint_notify_t *initiator = checklist->is_initiator ? local_endpoint : remote_endpoint;
+		endpoint_notify_t *responder = checklist->is_initiator ? remote_endpoint : local_endpoint;
+		
+		pair = endpoint_pair_create(initiator, responder, checklist->is_initiator);
+		pair->id = checklist->pairs->get_count(checklist->pairs) + 1;
+		
+		insert_pair_by_priority(checklist->pairs, pair);
+		
+		queue_triggered_check(checklist, pair);
+		
+		local_endpoint->destroy(local_endpoint);
+	}
+	
+	
+	check_t *response = check_create();
+	
+	response->mid = check->mid;
+	response->src = check->dst->clone(check->dst);
+	response->dst = check->src->clone(check->src);
+	response->session_id = chunk_clone(check->session_id);
+	response->endpoint = peer_reflexive;
+	
+	send_check(this, checklist, response, pair, FALSE);
+	
+	check_destroy(response);
+}
+
+/**
+ * Implementation of connect_manager_t.process_check.
+ */
+static void process_check(private_connect_manager_t *this, message_t *message)
+{
+	if (message->parse_body(message, NULL, NULL) != SUCCESS)
+	{
+		DBG1(DBG_IKE, "%N %s with message ID %d processing failed",
+			 exchange_type_names, message->get_exchange_type(message),
+			 message->get_request(message) ? "request" : "response",
+			 message->get_message_id(message));
+		return;
+	}
+	
+	check_t *check = check_create();
+	check->mid = message->get_message_id(message);
+	check->src = message->get_source(message);
+	check->dst = message->get_destination(message);
+	
+	if (process_payloads(message, check) != SUCCESS)
+	{
+		DBG1(DBG_IKE, "invalid connectivity check %s received",
+				message->get_request(message) ? "request" : "response");
+		check_destroy(check);
+		return;
+	}
+	
+	pthread_mutex_lock(&(this->mutex));
+	
+	check_list_t *checklist;
+	if (get_checklist_by_id(this, check->session_id, &checklist) != SUCCESS)
+	{
+		DBG1(DBG_IKE, "checklist with id '%B' not found",
+				&check->session_id);
+		check_destroy(check);
+		pthread_mutex_unlock(&(this->mutex));
+		return;
+	}
+	
+	chunk_t sig = build_signature(this, checklist, check, FALSE); 
+	if (!chunk_equals(sig, check->cookie))
+	{
+		DBG1(DBG_IKE, "connectivity check verification failed");
+		check_destroy(check);
+		chunk_free(&sig);
+		pthread_mutex_unlock(&(this->mutex));
+		return;
+	}
+	chunk_free(&sig);
+	
+	if (message->get_request(message))
+	{
+		process_request(this, check, checklist);
+	}
+	else
+	{
+		process_response(this, check, checklist);
+	}
+	
+	pthread_mutex_unlock(&(this->mutex));
+	
+	check_destroy(check);
+}
+
+// -----------------------------------------------------------------------------
+
+/**
+ * Implementation of connect_manager_t.check_and_register.
+ */
+static bool check_and_register(private_connect_manager_t *this,
+			identification_t *id, identification_t *peer_id,
+			ike_sa_id_t *mediated_sa, child_cfg_t *child)
+{
+	initiated_t *initiated;
+	bool already_there = TRUE;
+
+	pthread_mutex_lock(&(this->mutex));
+
+	if (get_initiated_by_ids(this, id, peer_id, &initiated) != SUCCESS)
+	{
+		DBG2(DBG_IKE, "registered waiting mediated connection with '%D'", peer_id);
+		initiated = initiated_create(id, peer_id);
+		this->initiated->insert_last(this->initiated, initiated);
+		already_there = FALSE;
+	}
+	
+	waiting_sa_t *waiting_sa;
+	if (get_waiting_sa(initiated, mediated_sa, &waiting_sa) != SUCCESS)
+	{
+		waiting_sa = waiting_sa_create(mediated_sa);
+		initiated->mediated->insert_last(initiated->mediated, waiting_sa);
+	}
+
+	child->get_ref(child);
+	waiting_sa->childs->insert_last(waiting_sa->childs, child);
+
+	pthread_mutex_unlock(&(this->mutex));
+
+	return already_there;
+}
+
+/**
+ * Implementation of connect_manager_t.check_and_initiate.
+ */
+static void check_and_initiate(private_connect_manager_t *this, ike_sa_id_t *mediation_sa,
+		identification_t *id, identification_t *peer_id)
+{
+	initiated_t *initiated;
+
+	pthread_mutex_lock(&(this->mutex));
+
+	if (get_initiated_by_ids(this, id, peer_id, &initiated) != SUCCESS)
+	{
+		DBG2(DBG_IKE, "no waiting mediated connections with '%D'", peer_id);
+		pthread_mutex_unlock(&(this->mutex));
+		return;
+	}
+	
+	waiting_sa_t *waiting_sa;
+	iterator_t *iterator = initiated->mediated->create_iterator(initiated->mediated, TRUE);
+	while (iterator->iterate(iterator, (void**)&waiting_sa))
+	{
+		job_t *job = (job_t*)reinitiate_mediation_job_create(mediation_sa,
+				waiting_sa->ike_sa_id);
+		charon->processor->queue_job(charon->processor, job);
+	}
+
+	pthread_mutex_unlock(&(this->mutex));
+}
+
+/**
+ * Implementation of connect_manager_t.set_initiator_data.
+ */
+static status_t set_initiator_data(private_connect_manager_t *this,
+		identification_t *initiator, identification_t *responder,
+		chunk_t session_id, chunk_t key, linked_list_t *endpoints, bool is_initiator)
+{
+	check_list_t *checklist;
+	
+	pthread_mutex_lock(&(this->mutex));	
+	
+	if (get_checklist_by_id(this, session_id, NULL) == SUCCESS)
+	{
+		DBG1(DBG_IKE, "checklist with id '%B' already exists, aborting",
+				&session_id);
+		pthread_mutex_unlock(&(this->mutex));
+		return FAILED;
+	}
+	
+	checklist = check_list_create(initiator, responder, session_id, key, endpoints, is_initiator);
+	this->checklists->insert_last(this->checklists, checklist);
+	
+	pthread_mutex_unlock(&(this->mutex));
+	
+	return SUCCESS;
+}
+
+/**
+ * Implementation of connect_manager_t.set_responder_data.
+ */
+static status_t set_responder_data(private_connect_manager_t *this,
+		chunk_t session_id, chunk_t key, linked_list_t *endpoints)
+{
+	check_list_t *checklist;
+
+	pthread_mutex_lock(&(this->mutex));
+	
+	if (get_checklist_by_id(this, session_id, &checklist) != SUCCESS)
+	{
+		DBG1(DBG_IKE, "checklist with id '%B' not found",
+				&session_id);
+		pthread_mutex_unlock(&(this->mutex));
+		return NOT_FOUND;
+	}
+	
+	checklist->responder.key = chunk_clone(key);
+	checklist->responder.endpoints = endpoints->clone_offset(endpoints, offsetof(endpoint_notify_t, clone));
+	checklist->state = CHECK_WAITING;
+	
+	build_pairs(checklist);
+	
+	schedule_checks(this, checklist, 0); // send the first check immediately
+	
+	pthread_mutex_unlock(&(this->mutex));
+	
+	return SUCCESS;
+}
+
+/**
+ * Implementation of connect_manager_t.destroy.
+ */
+static void destroy(private_connect_manager_t *this)
+{
+	pthread_mutex_lock(&(this->mutex));
+	
+	this->hasher->destroy(this->hasher);
+	this->checklists->destroy_function(this->checklists, (void*)check_list_destroy);
+	this->initiated->destroy_function(this->initiated, (void*)initiated_destroy);
+	
+	pthread_mutex_unlock(&(this->mutex));	
+	pthread_mutex_destroy(&(this->mutex));
+	free(this);
+}
+
+/*
+ * Described in header.
+ */
+connect_manager_t *connect_manager_create()
+{
+	private_connect_manager_t *this = malloc_thing(private_connect_manager_t);
+
+	this->public.destroy = (void(*)(connect_manager_t*))destroy;
+	this->public.check_and_register = (bool(*)(connect_manager_t*,identification_t*,identification_t*,ike_sa_id_t*,child_cfg_t*))check_and_register;
+	this->public.check_and_initiate = (void(*)(connect_manager_t*,ike_sa_id_t*,identification_t*,identification_t*))check_and_initiate;
+	this->public.set_initiator_data = (status_t(*)(connect_manager_t*,identification_t*,identification_t*,chunk_t,chunk_t,linked_list_t*,bool))set_initiator_data;
+	this->public.set_responder_data = (status_t(*)(connect_manager_t*,chunk_t,chunk_t,linked_list_t*))set_responder_data;
+	this->public.process_check = (void(*)(connect_manager_t*,message_t*))process_check;
+	
+	this->hasher = hasher_create(HASH_SHA1);
+	this->checklists = linked_list_create();
+	this->initiated = linked_list_create();
+	
+	pthread_mutex_init(&(this->mutex), NULL);
+	
+	return (connect_manager_t*)this;
+}
diff --git a/src/charon/sa/connect_manager.h b/src/charon/sa/connect_manager.h
new file mode 100644
index 000000000..2f3e9109b
--- /dev/null
+++ b/src/charon/sa/connect_manager.h
@@ -0,0 +1,131 @@
+/**
+ * @file connect_manager.h
+ * 
+ * @brief Interface of connect_manager_t.
+ * 
+ */
+
+/*
+ * Copyright (C) 2007 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.
+ */
+
+#ifndef CONNECT_MANAGER_H_
+#define CONNECT_MANAGER_H_
+
+typedef struct connect_manager_t connect_manager_t;
+
+#include <encoding/message.h>
+#include <config/child_cfg.h>
+#include <sa/ike_sa_id.h>
+#include <utils/identification.h>
+
+/**
+ * @brief The connection manager is responsible for establishing a direct
+ * connection with another peer.
+ * 
+ * @b Constructors:
+ * - connect_manager_create()
+ * 
+ * @ingroup sa
+ */
+struct connect_manager_t {
+	
+	/**
+	 * @brief Checks if a there is already a mediated connection registered
+	 * between two peers.
+	 * 
+	 * @param this 				the manager object
+	 * @param id				my id
+	 * @param peer_id			the other peer's id
+	 * @param mediated_sa		the IKE_SA ID of the mediated connection
+	 * @param child				the CHILD_SA config of the mediated connection 
+	 * @returns 				
+	 * 							- TRUE, if there was already a mediated connection registered
+	 * 							- FALSE, otherwise
+	 */
+	bool (*check_and_register) (connect_manager_t *this,
+			identification_t *id, identification_t *peer_id,
+			ike_sa_id_t *mediated_sa, child_cfg_t *child);
+	
+	/**
+	 * @brief Checks if there are waiting connections with a specific peer.
+	 * If so, reinitiate them.
+	 * 
+	 * @param this 				the manager object
+	 * @param id				my id
+	 * @param peer_id			the other peer's id
+	 */
+	void (*check_and_initiate) (connect_manager_t *this, ike_sa_id_t *mediation_sa,
+			identification_t *id, identification_t *peer_id);
+	
+	/**
+	 * @brief Creates a checklist and sets the initiator's data.
+	 * 
+	 * @param this 				the manager object
+	 * @param initiator			ID of the initiator
+	 * @param responder			ID of the responder
+	 * @param session_id		the session ID provided by the initiator
+	 * @param key				the initiator's key
+	 * @param endpoints			the initiator's endpoints
+	 * @param is_initiator		TRUE, if the caller of this method is the initiator
+	 * 							FALSE, otherwise
+	 * @returns
+	 * 							SUCCESS
+	 */
+	status_t (*set_initiator_data) (connect_manager_t *this,
+		identification_t *initiator, identification_t *responder,
+		chunk_t session_id, chunk_t key, linked_list_t *endpoints, bool is_initiator);
+	
+	/**
+	 * @brief Updates a checklist and sets the responder's data. The checklist's
+	 * state is advanced to WAITING which means that checks will be sent.
+	 * 
+	 * @param this 				the manager object
+	 * @param session_id		the session ID
+	 * @param chunk_t			the responder's key
+	 * @param endpoints			the responder's endpoints 
+	 * @returns 				
+	 * 							- NOT_FOUND, if the checklist has not been found
+	 * 							- SUCCESS, otherwise
+	 */
+	status_t (*set_responder_data) (connect_manager_t *this,
+		chunk_t session_id, chunk_t key, linked_list_t *endpoints);
+	
+	
+	/**
+	 * @brief Processes a connectivity check
+	 * 
+	 * @param this				the manager object
+	 * @param message			the received message
+	 */
+	void (*process_check) (connect_manager_t *this, message_t *message);
+	
+	/**
+	 * @brief Destroys the manager with all data.
+	 * 
+	 * @param this				 the manager object
+	 */
+	void (*destroy) (connect_manager_t *this);
+};
+
+/**
+ * @brief Create a manager.
+ * 
+ * @returns 	connect_manager_t object
+ * 
+ * @ingroup sa
+ */
+connect_manager_t *connect_manager_create(void);
+
+#endif /*CONNECT_MANAGER_H_*/
diff --git a/src/charon/sa/ike_sa.c b/src/charon/sa/ike_sa.c
index 42cda721b..9d7a17e89 100644
--- a/src/charon/sa/ike_sa.c
+++ b/src/charon/sa/ike_sa.c
@@ -6,7 +6,8 @@
  */
 
 /*
- * Copyright (C) 2006 Tobias Brunner, Daniel Roethlisberger
+ * Copyright (C) 2006-2007 Tobias Brunner
+ * Copyright (C) 2006 Daniel Roethlisberger
  * Copyright (C) 2005-2006 Martin Willi
  * Copyright (C) 2005 Jan Hutter
  * Hochschule fuer Technik Rapperswil
@@ -65,6 +66,9 @@
 #include <processing/jobs/send_keepalive_job.h>
 #include <processing/jobs/rekey_ike_sa_job.h>
 
+#ifdef P2P
+#include <sa/tasks/ike_p2p.h>
+#endif
 
 #ifndef RESOLV_CONF
 #define RESOLV_CONF "/etc/resolv.conf"
@@ -130,6 +134,13 @@ struct private_ike_sa_t {
 	 */
 	host_t *other_host;
 	
+#ifdef P2P	
+	/**
+	 * Server reflexive host
+	 */
+	host_t *server_reflexive_host;
+#endif /* P2P */
+		
 	/**
 	 * Identification used for us
 	 */
@@ -855,6 +866,92 @@ static void send_notify_response(private_ike_sa_t *this, message_t *request,
 	response->destroy(response);
 }
 
+#ifdef P2P
+/**
+ * Implementation of ike_sa_t.get_server_reflexive_host.
+ */
+static host_t *get_server_reflexive_host(private_ike_sa_t *this)
+{
+	return this->server_reflexive_host;
+}
+
+/**
+ * Implementation of ike_sa_t.set_server_reflexive_host.
+ */
+static void set_server_reflexive_host(private_ike_sa_t *this, host_t *host)
+{
+	DESTROY_IF(this->server_reflexive_host);
+	this->server_reflexive_host = host;
+}
+
+/**
+ * Implementation of ike_sa_t.respond
+ */
+static status_t respond(private_ike_sa_t *this, identification_t *peer_id,
+		chunk_t session_id)
+{
+	ike_p2p_t *task = ike_p2p_create(&this->public, TRUE);
+	task->respond(task, peer_id, session_id);
+	this->task_manager->queue_task(this->task_manager, (task_t*)task);
+	return this->task_manager->initiate(this->task_manager);
+}
+
+/**
+ * Implementation of ike_sa_t.callback
+ */
+static status_t callback(private_ike_sa_t *this, identification_t *peer_id)
+{
+	ike_p2p_t *task = ike_p2p_create(&this->public, TRUE);
+	task->callback(task, peer_id);
+	this->task_manager->queue_task(this->task_manager, (task_t*)task);
+	return this->task_manager->initiate(this->task_manager);
+}
+
+/**
+ * Implementation of ike_sa_t.relay
+ */
+static status_t relay(private_ike_sa_t *this, identification_t *requester,
+			chunk_t session_id, chunk_t session_key, linked_list_t *endpoints, bool response)
+{
+	ike_p2p_t *task = ike_p2p_create(&this->public, TRUE);
+	task->relay(task, requester, session_id, session_key, endpoints, response);
+	this->task_manager->queue_task(this->task_manager, (task_t*)task);
+	return this->task_manager->initiate(this->task_manager);
+}
+
+/**
+ * Implementation of ike_sa_t.initiate_mediation
+ */
+static status_t initiate_mediation(private_ike_sa_t *this, peer_cfg_t *mediated_cfg)
+{
+	ike_p2p_t *task = ike_p2p_create(&this->public, TRUE);
+	task->connect(task, mediated_cfg->get_peer_id(mediated_cfg));
+	this->task_manager->queue_task(this->task_manager, (task_t*)task);
+	return this->task_manager->initiate(this->task_manager);
+}
+
+/**
+ * Implementation of ike_sa_t.initiate_mediated
+ */
+static status_t initiate_mediated(private_ike_sa_t *this, host_t *me, host_t *other,
+		linked_list_t *childs)
+{
+	this->my_host = me->clone(me);
+	this->other_host = other->clone(other);
+	
+	task_t *task;
+	child_cfg_t *child_cfg;	
+	iterator_t *iterator = childs->create_iterator(childs, TRUE);
+	while (iterator->iterate(iterator, (void**)&child_cfg))
+	{
+		task = (task_t*)child_create_create(&this->public, child_cfg);
+		this->task_manager->queue_task(this->task_manager, task);
+	}
+	iterator->destroy(iterator);
+	return this->task_manager->initiate(this->task_manager);
+}
+#endif /* P2P */
+
 /**
  * Implementation of ike_sa_t.initiate.
  */
@@ -864,7 +961,11 @@ static status_t initiate(private_ike_sa_t *this, child_cfg_t *child_cfg)
 	
 	if (this->state == IKE_CREATED)
 	{
-		if (this->other_host->is_anyaddr(this->other_host))
+		if (this->other_host->is_anyaddr(this->other_host)
+#ifdef P2P
+			&& !this->peer_cfg->get_mediated_by(this->peer_cfg)
+#endif /* P2P */
+			)
 		{
 			child_cfg->destroy(child_cfg);
 			SIG(IKE_UP_START, "initiating IKE_SA");
@@ -887,11 +988,36 @@ static status_t initiate(private_ike_sa_t *this, child_cfg_t *child_cfg)
 			task = (task_t*)ike_mobike_create(&this->public, TRUE);
 			this->task_manager->queue_task(this->task_manager, task);
 		}
+#ifdef P2P
+		task = (task_t*)ike_p2p_create(&this->public, TRUE);
+		this->task_manager->queue_task(this->task_manager, task);
+#endif /* P2P */
+	}
+
+#ifdef P2P
+	if (this->peer_cfg->get_mediated_by(this->peer_cfg))
+	{
+		// mediated connection, initiate mediation process
+		job_t *job = (job_t*)initiate_mediation_job_create(this->ike_sa_id, child_cfg);
+		child_cfg->destroy(child_cfg);
+		charon->processor->queue_job(charon->processor, job);
+		return SUCCESS;
+	}
+	else if (this->peer_cfg->is_mediation(this->peer_cfg))
+	{
+		if (this->state == IKE_ESTABLISHED)
+		{// FIXME: we should try to find a better solution to this
+			SIG(CHILD_UP_SUCCESS, "mediation connection is already up and running");
+		}
+	}
+	else
+#endif /* P2P */
+	{
+		// normal IKE_SA with CHILD_SA
+		task = (task_t*)child_create_create(&this->public, child_cfg);
+		child_cfg->destroy(child_cfg);
+		this->task_manager->queue_task(this->task_manager, task);
 	}
-	
-	task = (task_t*)child_create_create(&this->public, child_cfg);
-	child_cfg->destroy(child_cfg);
-	this->task_manager->queue_task(this->task_manager, task);
 	
 	return this->task_manager->initiate(this->task_manager);
 }
@@ -900,7 +1026,7 @@ static status_t initiate(private_ike_sa_t *this, child_cfg_t *child_cfg)
  * Implementation of ike_sa_t.acquire.
  */
 static status_t acquire(private_ike_sa_t *this, u_int32_t reqid)
-{
+{// FIXME: P2P-NAT-T
 	child_cfg_t *child_cfg;
 	iterator_t *iterator;
 	child_sa_t *current, *child_sa = NULL;
@@ -1224,7 +1350,7 @@ static status_t process_message(private_ike_sa_t *this, message_t *message)
  * Implementation of ike_sa_t.retransmit.
  */
 static status_t retransmit(private_ike_sa_t *this, u_int32_t message_id)
-{
+{// FIXME: P2P-NAT-T
 	this->time.outbound = time(NULL);
 	if (this->task_manager->retransmit(this->task_manager, message_id) != SUCCESS)
 	{
@@ -2047,6 +2173,15 @@ static void destroy(private_ike_sa_t *this)
 													offsetof(host_t, destroy));
 	this->additional_addresses->destroy_offset(this->additional_addresses,
 													offsetof(host_t, destroy));
+#ifdef P2P	
+	if (this->peer_cfg && this->peer_cfg->is_mediation(this->peer_cfg) &&
+			!this->ike_sa_id->is_initiator(this->ike_sa_id))
+	{
+		// mediation server
+		charon->mediation_manager->remove(charon->mediation_manager, this->ike_sa_id);
+	}
+	DESTROY_IF(this->server_reflexive_host);
+#endif /* P2P */
 	
 	DESTROY_IF(this->my_host);
 	DESTROY_IF(this->other_host);
@@ -2129,6 +2264,15 @@ ike_sa_t * ike_sa_create(ike_sa_id_t *ike_sa_id)
 	this->public.set_virtual_ip = (void (*)(ike_sa_t*,bool,host_t*))set_virtual_ip;
 	this->public.get_virtual_ip = (host_t* (*)(ike_sa_t*,bool))get_virtual_ip;
 	this->public.add_dns_server = (void (*)(ike_sa_t*,host_t*))add_dns_server;
+#ifdef P2P
+	this->public.get_server_reflexive_host = (host_t* (*)(ike_sa_t*)) get_server_reflexive_host;
+	this->public.set_server_reflexive_host = (void (*)(ike_sa_t*,host_t*)) set_server_reflexive_host;
+	this->public.initiate_mediation = (status_t (*)(ike_sa_t*,peer_cfg_t*)) initiate_mediation;
+	this->public.initiate_mediated = (status_t (*)(ike_sa_t*,host_t*,host_t*,linked_list_t*)) initiate_mediated;
+	this->public.relay = (status_t (*)(ike_sa_t*,identification_t*,chunk_t,chunk_t,linked_list_t*,bool)) relay;
+	this->public.callback = (status_t (*)(ike_sa_t*,identification_t*)) callback;
+	this->public.respond = (status_t (*)(ike_sa_t*,identification_t*,chunk_t)) respond;
+#endif /* P2P */
 	
 	/* initialize private fields */
 	this->ike_sa_id = ike_sa_id->clone(ike_sa_id);
@@ -2163,6 +2307,9 @@ ike_sa_t * ike_sa_create(ike_sa_id_t *ike_sa_id)
 	this->additional_addresses = linked_list_create();
 	this->pending_updates = 0;
 	this->keyingtry = 0;
+#ifdef P2P
+	this->server_reflexive_host = NULL;
+#endif /* P2P */
 	
 	return &this->public;
 }
diff --git a/src/charon/sa/ike_sa.h b/src/charon/sa/ike_sa.h
index 67d6a8853..99f09e98a 100644
--- a/src/charon/sa/ike_sa.h
+++ b/src/charon/sa/ike_sa.h
@@ -6,7 +6,8 @@
  */
 
 /*
- * Copyright (C) 2006 Tobias Brunner, Daniel Roethlisberger
+ * Copyright (C) 2006-2007 Tobias Brunner
+ * Copyright (C) 2006 Daniel Roethlisberger
  * Copyright (C) 2005-2006 Martin Willi
  * Copyright (C) 2005 Jan Hutter
  * Hochschule fuer Technik Rapperswil
@@ -452,6 +453,96 @@ struct ike_sa_t {
 	 * @param updates		number of pending updates
 	 */
 	void (*set_pending_updates)(ike_sa_t *this, u_int32_t updates);
+
+#ifdef P2P
+	/**
+	 * @brief Get the server reflexive host.
+	 * 
+	 * @param this 			calling object
+	 * @return				server reflexive host
+	 */
+	host_t* (*get_server_reflexive_host) (ike_sa_t *this);
+	
+	/**
+	 * @brief Set the server reflexive host.
+	 * 
+	 * @param this 			calling object
+	 * @param host			server reflexive host
+	 */
+	void (*set_server_reflexive_host) (ike_sa_t *this, host_t *host);
+	
+	/**
+	 * @brief Initiate the mediation of a mediated connection (i.e. initiate a
+	 * P2P_CONNECT exchange).
+	 * 
+	 * @param this 				calling object
+	 * @param mediated_cfg		peer_cfg of the mediated connection
+	 * @return				
+	 * 						- SUCCESS if initialization started
+	 * 						- DESTROY_ME if initialization failed
+	 */
+	status_t (*initiate_mediation) (ike_sa_t *this, peer_cfg_t *mediated_cfg);
+	
+	/**
+	 * @brief Initiate the mediated connection
+	 * 
+	 * @param this 				calling object
+	 * @param me				local endpoint (gets cloned)
+	 * @param other				remote endpoint (gets cloned)
+	 * @param childs			linked list of child_cfg_t of CHILD_SAs (gets cloned)
+	 * @return				
+	 * 						- SUCCESS if initialization started
+	 * 						- DESTROY_ME if initialization failed
+	 */
+	status_t (*initiate_mediated) (ike_sa_t *this, host_t *me, host_t *other,
+			linked_list_t *childs);
+	
+	/**
+	 * @brief Relay data from one peer to another (i.e. initiate a
+	 * P2P_CONNECT exchange).
+	 *
+	 * Data is cloned.
+	 * 
+	 * @param this 				calling object
+	 * @param requester			ID of the requesting peer
+	 * @param session_id		data of the P2P_SESSIONID payload
+	 * @param session_key		data of the P2P_SESSIONKEY payload
+	 * @param endpoints			endpoints
+	 * @param response			TRUE if this is a response
+	 * @return				
+	 * 						- SUCCESS if relay started
+	 * 						- DESTROY_ME if relay failed
+	 */
+	status_t (*relay) (ike_sa_t *this, identification_t *requester, chunk_t session_id,
+			chunk_t session_key, linked_list_t *endpoints, bool response);
+	
+	/**
+	 * @brief Send a callback to a peer.
+	 * 
+	 * Data is cloned.
+	 * 
+	 * @param this				calling object
+	 * @param peer_id			ID of the other peer
+	 * @return
+	 * 						- SUCCESS if response started
+	 * 						- DESTROY_ME if response failed
+	 */
+	status_t (*callback) (ike_sa_t *this, identification_t *peer_id);
+	
+	/**
+	 * @brief Respond to a P2P_CONNECT request.
+	 * 
+	 * Data is cloned.
+	 * 
+	 * @param this				calling object
+	 * @param peer_id			ID of the other peer
+	 * @param session_id		the session ID supplied by the initiator
+	 * @return
+	 * 						- SUCCESS if response started
+	 * 						- DESTROY_ME if response failed
+	 */
+	status_t (*respond) (ike_sa_t *this, identification_t *peer_id, chunk_t session_id);
+#endif /* P2P */
 	
 	/**
 	 * @brief Initiate a new connection.
diff --git a/src/charon/sa/mediation_manager.c b/src/charon/sa/mediation_manager.c
new file mode 100644
index 000000000..fca53a940
--- /dev/null
+++ b/src/charon/sa/mediation_manager.c
@@ -0,0 +1,343 @@
+/**
+ * @file mediation_manager.c
+ *
+ * @brief Implementation of mediation_manager_t.
+ *
+ */
+
+/*
+ * Copyright (C) 2007 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 "mediation_manager.h"
+
+#include <pthread.h>
+#include <daemon.h>
+#include <utils/linked_list.h>
+#include <processing/jobs/mediation_job.h>
+
+
+typedef struct peer_t peer_t;
+
+/**
+ * An entry in the linked list.
+ */
+struct peer_t {
+	/** id of the peer */
+    identification_t *id;
+
+	/** sa id of the peer, NULL if offline */
+    ike_sa_id_t *ike_sa_id;   
+    
+    /** list of peer ids that reuested this peer */
+    linked_list_t *requested_by;
+};
+
+/**
+ * Implementation of peer_t.destroy.
+ */
+static void peer_destroy(peer_t *this)
+{
+	DESTROY_IF(this->id);
+    DESTROY_IF(this->ike_sa_id);
+    this->requested_by->destroy_offset(this->requested_by, offsetof(identification_t, destroy));
+	free(this);
+}
+
+/**
+ * Creates a new entry for the list.
+ */
+static peer_t *peer_create(identification_t *id, ike_sa_id_t* ike_sa_id)
+{
+	peer_t *this = malloc_thing(peer_t);
+	
+	/* clone everything */
+	this->id = id->clone(id);
+    this->ike_sa_id = ike_sa_id ? ike_sa_id->clone(ike_sa_id) : NULL;
+    this->requested_by = linked_list_create();
+    
+	return this;
+}
+
+
+typedef struct private_mediation_manager_t private_mediation_manager_t;
+
+/**
+ * Additional private members of mediation_manager_t.
+ */
+struct private_mediation_manager_t {
+	/**
+	 * Public interface of mediation_manager_t.
+	 */
+	 mediation_manager_t public;
+	
+	 /**
+	  * Lock for exclusivly accessing the manager.
+	  */
+	 pthread_mutex_t mutex;
+
+	 /**
+	  * Linked list with state entries.
+	  */
+	 linked_list_t *peers;
+};
+
+/**
+ * Registers a peer's ID at another peer, if it is not yet registered
+ */
+static void register_peer(peer_t *peer, identification_t *peer_id)
+{
+	iterator_t *iterator;
+	identification_t *current;
+	
+	iterator = peer->requested_by->create_iterator(peer->requested_by, TRUE);
+	while (iterator->iterate(iterator, (void**)&current))
+	{
+		if (peer_id->equals(peer_id, current))
+		{
+			iterator->destroy(iterator);
+			return;
+		}
+	}
+	iterator->destroy(iterator);
+	
+	peer->requested_by->insert_last(peer->requested_by, peer_id->clone(peer_id));
+}
+
+/**
+ * Get a peer_t object by a peer's id
+ */
+static status_t get_peer_by_id(private_mediation_manager_t *this,
+		identification_t *id, peer_t **peer)
+{
+	iterator_t *iterator;
+	peer_t *current;
+	status_t status = NOT_FOUND;
+	
+	iterator = this->peers->create_iterator(this->peers, TRUE);
+	while (iterator->iterate(iterator, (void**)&current))
+	{
+		if (id->equals(id, current->id))
+		{
+			if (peer)
+			{
+				*peer = current;
+			}
+			status = SUCCESS;
+			break;
+		}
+	}
+	iterator->destroy(iterator);
+
+	return status;
+}
+
+/**
+ * Check if a given peer is registered at other peers. If so, remove it there
+ * and then remove peers completely that are not online and have no registered
+ * peers.
+ */
+static void unregister_peer(private_mediation_manager_t *this, identification_t *peer_id)
+{
+	iterator_t *iterator, *iterator_r;
+	peer_t *peer;
+	identification_t *registered;
+
+	iterator = this->peers->create_iterator(this->peers, TRUE);
+	while (iterator->iterate(iterator, (void**)&peer))
+	{
+		iterator_r = peer->requested_by->create_iterator(peer->requested_by, TRUE);
+		while (iterator_r->iterate(iterator_r, (void**)&registered))
+		{
+			if (peer_id->equals(peer_id, registered))
+			{
+				iterator_r->remove(iterator_r);
+				registered->destroy(registered);
+				break;
+			}
+		}
+		iterator_r->destroy(iterator_r);
+		
+		if (!peer->ike_sa_id && !peer->requested_by->get_count(peer->requested_by))
+		{
+			iterator->remove(iterator);
+			peer_destroy(peer);
+			break;
+		}
+	}
+	iterator->destroy(iterator);
+}
+
+/**
+ * Implementation of mediation_manager_t.remove
+ */
+static void remove_sa(private_mediation_manager_t *this, ike_sa_id_t *ike_sa_id)
+{
+	iterator_t *iterator;
+	peer_t *peer;
+
+	pthread_mutex_lock(&(this->mutex));
+	
+	iterator = this->peers->create_iterator(this->peers, TRUE);
+	while (iterator->iterate(iterator, (void**)&peer))
+	{
+		if (ike_sa_id->equals(ike_sa_id, peer->ike_sa_id))
+		{
+			iterator->remove(iterator);
+			
+			unregister_peer(this, peer->id);
+			
+			peer_destroy(peer);
+			break;
+		}
+	}
+	iterator->destroy(iterator);
+
+	pthread_mutex_unlock(&(this->mutex));
+}
+
+/**
+ * Implementation of mediation_manager_t.update_sa_id
+ */
+static void update_sa_id(private_mediation_manager_t *this, identification_t *peer_id, ike_sa_id_t *ike_sa_id)
+{
+	iterator_t *iterator;
+	peer_t *peer;
+	bool found = FALSE;
+
+	pthread_mutex_lock(&(this->mutex));
+
+	iterator = this->peers->create_iterator(this->peers, TRUE);
+	while (iterator->iterate(iterator, (void**)&peer))
+	{
+		if (peer_id->equals(peer_id, peer->id))
+		{
+			DESTROY_IF(peer->ike_sa_id);
+			found = TRUE;
+			break;
+		}
+	}
+	iterator->destroy(iterator);
+	
+	if (!found)
+	{
+		DBG2(DBG_IKE, "adding peer '%D'", peer_id);
+		peer = peer_create(peer_id, NULL);
+		this->peers->insert_last(this->peers, peer);
+	}
+
+	DBG2(DBG_IKE, "changing registered IKE_SA ID of peer '%D'", peer_id);			
+	peer->ike_sa_id = ike_sa_id ? ike_sa_id->clone(ike_sa_id) : NULL;
+	
+	// send callbacks to registered peers
+	identification_t *requester;
+	while(peer->requested_by->remove_last(peer->requested_by, (void**)&requester) == SUCCESS)
+	{
+		job_t *job = (job_t*)mediation_callback_job_create(requester, peer_id);
+		charon->processor->queue_job(charon->processor, job);
+	}
+	
+	pthread_mutex_unlock(&(this->mutex));
+}
+
+/**
+ * Implementation of mediation_manager_t.check.
+ */
+static ike_sa_id_t *check(private_mediation_manager_t *this,
+			identification_t *peer_id)
+{
+	peer_t *peer;
+	ike_sa_id_t *ike_sa_id;
+
+	pthread_mutex_lock(&(this->mutex));
+
+	if (get_peer_by_id(this, peer_id, &peer) != SUCCESS)
+	{
+		pthread_mutex_unlock(&(this->mutex));
+		return NULL;
+	}
+
+	ike_sa_id = peer->ike_sa_id;
+
+	pthread_mutex_unlock(&(this->mutex));
+
+	return ike_sa_id;
+}
+
+/**
+ * Implementation of mediation_manager_t.check_and_register.
+ */
+static ike_sa_id_t *check_and_register(private_mediation_manager_t *this,
+			identification_t *peer_id, identification_t *requester)
+{
+	peer_t *peer;
+	ike_sa_id_t *ike_sa_id;
+
+	pthread_mutex_lock(&(this->mutex));
+
+	if (get_peer_by_id(this, peer_id, &peer) != SUCCESS)
+	{
+		DBG2(DBG_IKE, "adding peer %D", peer_id);
+		peer = peer_create(peer_id, NULL);
+		this->peers->insert_last(this->peers, peer);
+	}
+	
+	if (!peer->ike_sa_id)
+	{
+		// the peer is not online
+		DBG2(DBG_IKE, "requested peer '%D' is offline, registering peer '%D'", peer_id, requester);
+		register_peer(peer, requester);
+		pthread_mutex_unlock(&(this->mutex));
+		return NULL;
+	}
+
+	ike_sa_id = peer->ike_sa_id;
+
+	pthread_mutex_unlock(&(this->mutex));
+
+	return ike_sa_id;
+}
+
+/**
+ * Implementation of mediation_manager_t.destroy.
+ */
+static void destroy(private_mediation_manager_t *this)
+{
+	pthread_mutex_lock(&(this->mutex));
+	
+	this->peers->destroy_function(this->peers, (void*)peer_destroy);
+	
+	pthread_mutex_unlock(&(this->mutex));	
+	pthread_mutex_destroy(&(this->mutex));
+	free(this);
+}
+
+/*
+ * Described in header.
+ */
+mediation_manager_t *mediation_manager_create()
+{
+	private_mediation_manager_t *this = malloc_thing(private_mediation_manager_t);
+
+	this->public.destroy = (void(*)(mediation_manager_t*))destroy;
+	this->public.remove = (void(*)(mediation_manager_t*,ike_sa_id_t*))remove_sa;
+	this->public.update_sa_id = (void(*)(mediation_manager_t*,identification_t*,ike_sa_id_t*))update_sa_id;
+	this->public.check = (ike_sa_id_t*(*)(mediation_manager_t*,identification_t*))check;
+	this->public.check_and_register = (ike_sa_id_t*(*)(mediation_manager_t*,identification_t*,identification_t*))check_and_register;
+	
+	this->peers = linked_list_create();
+	pthread_mutex_init(&(this->mutex), NULL);
+	
+	return (mediation_manager_t*)this;
+}
diff --git a/src/charon/sa/mediation_manager.h b/src/charon/sa/mediation_manager.h
new file mode 100644
index 000000000..74acc4d41
--- /dev/null
+++ b/src/charon/sa/mediation_manager.h
@@ -0,0 +1,104 @@
+/**
+ * @file mediation_manager.h
+ * 
+ * @brief Interface of mediation_manager_t.
+ * 
+ */
+
+/*
+ * Copyright (C) 2007 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.
+ */
+
+#ifndef MEDIATION_MANAGER_H_
+#define MEDIATION_MANAGER_H_
+
+typedef struct mediation_manager_t mediation_manager_t;
+
+#include <sa/ike_sa_id.h>
+#include <utils/identification.h>
+
+/**
+ * @brief The mediation manager is responsible for managing currently online
+ * peers and registered requests for offline peers on the mediation server.
+ * 
+ * @b Constructors:
+ * - mediation_manager_create()
+ * 
+ * @ingroup sa
+ */
+struct mediation_manager_t {
+	
+	/**
+	 * @brief Remove the IKE_SA of a peer.
+	 * 
+	 * @param this 				the manager object
+	 * @param ike_sa_id			the IKE_SA ID of the peer's SA
+	 */
+	void (*remove) (mediation_manager_t* this, ike_sa_id_t *ike_sa_id);
+	
+	/**
+	 * @brief Update the ike_sa_id that is assigned to a peer's ID. If the peer
+	 * is new, it gets a new record assigned. 
+	 * 
+	 * @param this 				the manager object
+	 * @param peer_id			the peer's ID
+	 * @param ike_sa_id			the IKE_SA ID of the peer's SA
+	 */
+	void (*update_sa_id) (mediation_manager_t* this, identification_t *peer_id,
+			ike_sa_id_t *ike_sa_id);
+	
+	/**
+	 * @brief Checks if a specific peer is online.
+	 * 
+	 * @param this 				the manager object
+	 * @param peer_id			the peer's ID
+	 * @returns 					
+	 * 							- IKE_SA ID of the peer's SA.
+	 * 							- NULL, if the peer is not online.
+	 */
+	ike_sa_id_t* (*check) (mediation_manager_t* this,
+			identification_t *peer_id);
+	
+	/**
+	 * @brief Checks if a specific peer is online and registers the requesting
+	 * peer if it is not.
+	 * 
+	 * @param this 				the manager object
+	 * @param peer_id			the peer's ID
+	 * @param requester			the requesters ID
+	 * @returns 					
+	 * 							- IKE_SA ID of the peer's SA.
+	 * 							- NULL, if the peer is not online.
+	 */
+	ike_sa_id_t* (*check_and_register) (mediation_manager_t* this,
+			identification_t *peer_id, identification_t *requester);
+	
+	/**
+	 * @brief Destroys the manager with all data.
+	 * 
+	 * @param this				 the manager object
+	 */
+	void (*destroy) (mediation_manager_t *this);
+};
+
+/**
+ * @brief Create a manager.
+ * 
+ * @returns 	mediation_manager_t object
+ * 
+ * @ingroup sa
+ */
+mediation_manager_t *mediation_manager_create(void);
+
+#endif /*MEDIATION_MANAGER_H_*/
diff --git a/src/charon/sa/task_manager.c b/src/charon/sa/task_manager.c
index 1b2c0f590..f4484774e 100644
--- a/src/charon/sa/task_manager.c
+++ b/src/charon/sa/task_manager.c
@@ -6,6 +6,7 @@
  */
 
 /*
+ * Copyright (C) 2007 Tobias Brunner
  * Copyright (C) 2007 Martin Willi
  * Hochschule fuer Technik Rapperswil
  *
@@ -40,6 +41,10 @@
 #include <encoding/payloads/delete_payload.h>
 #include <processing/jobs/retransmit_job.h>
 
+#ifdef P2P
+#include <sa/tasks/ike_p2p.h>
+#endif
+
 typedef struct exchange_t exchange_t;
 
 /**
@@ -323,6 +328,13 @@ static status_t build_request(private_task_manager_t *this)
 					exchange = IKE_SA_INIT;
 					activate_task(this, IKE_NATD);
 					activate_task(this, IKE_CERT);
+#ifdef P2P
+					/* this task has to be activated before the IKE_AUTHENTICATE
+					 * task, because that task pregenerates the packet after
+					 * which no payloads can be added to the message anymore.
+					 */
+					activate_task(this, IKE_P2P);
+#endif /* P2P */
 					activate_task(this, IKE_AUTHENTICATE);
 					activate_task(this, IKE_CONFIG);
 					activate_task(this, CHILD_CREATE);
@@ -370,6 +382,13 @@ static status_t build_request(private_task_manager_t *this)
 					exchange = INFORMATIONAL;
 					break;
 				}
+#ifdef P2P
+				if (activate_task(this, IKE_P2P))
+				{
+					exchange = P2P_CONNECT;
+					break;
+				}
+#endif /* P2P */
 			case IKE_REKEYING:
 				if (activate_task(this, IKE_DELETE))
 				{
@@ -668,6 +687,10 @@ static status_t process_request(private_task_manager_t *this,
 			this->passive_tasks->insert_last(this->passive_tasks, task);
 			task = (task_t*)ike_cert_create(this->ike_sa, FALSE);
 			this->passive_tasks->insert_last(this->passive_tasks, task);
+#ifdef P2P			
+			task = (task_t*)ike_p2p_create(this->ike_sa, FALSE);
+			this->passive_tasks->insert_last(this->passive_tasks, task);
+#endif /* P2P */			
 			task = (task_t*)ike_auth_create(this->ike_sa, FALSE);
 			this->passive_tasks->insert_last(this->passive_tasks, task);
 			task = (task_t*)ike_config_create(this->ike_sa, FALSE);
@@ -679,7 +702,7 @@ static status_t process_request(private_task_manager_t *this,
 			break;
 		}
 		case CREATE_CHILD_SA:
-		{
+		{//FIXME: we should prevent this on mediation connections
 			bool notify_found = FALSE, ts_found = FALSE;
 			iterator = message->get_payload_iterator(message);
 			while (iterator->iterate(iterator, (void**)&payload))
@@ -787,6 +810,13 @@ static status_t process_request(private_task_manager_t *this,
 			this->passive_tasks->insert_last(this->passive_tasks, task);
 			break;
 		}
+#ifdef P2P
+		case P2P_CONNECT:
+		{
+			task = (task_t*)ike_p2p_create(this->ike_sa, FALSE);
+			this->passive_tasks->insert_last(this->passive_tasks, task);
+		}
+#endif /* P2P */
 		default:
 			break;
 	}
diff --git a/src/charon/sa/tasks/ike_natd.c b/src/charon/sa/tasks/ike_natd.c
index 32665393d..4c64ff8ba 100644
--- a/src/charon/sa/tasks/ike_natd.c
+++ b/src/charon/sa/tasks/ike_natd.c
@@ -91,7 +91,7 @@ static chunk_t generate_natd_hash(private_ike_natd_t *this,
 	u_int64_t spi_i, spi_r;
 	u_int16_t port;
 	
-	/* prepare all requred chunks */
+	/* 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;
@@ -258,8 +258,23 @@ static status_t process_i(private_ike_natd_t *this, message_t *message)
 	if (message->get_exchange_type(message) == IKE_SA_INIT)
 	{
 		peer_cfg_t *peer_cfg = this->ike_sa->get_peer_cfg(this->ike_sa);
-				
+
+#ifdef P2P		
+		/* if we are on a mediated connection we have already switched to
+		 * port 4500 and the correct destination port is already configured,
+		 * therefore we must not switch again */
+		if (peer_cfg->get_mediated_by(peer_cfg))
+		{
+			return SUCCESS;
+		}
+#endif /* P2P */
+		
 		if (this->ike_sa->has_condition(this->ike_sa, COND_NAT_ANY) ||
+#ifdef P2P
+			/* if we are on a mediation connection we swith to port 4500 even
+			 * if no NAT is detected. */
+			peer_cfg->is_mediation(peer_cfg) ||
+#endif /* P2P */
 			/* if peer supports NAT-T, we switch to port 4500 even
 			 * if no NAT is detected. MOBIKE requires this. */
 			(peer_cfg->use_mobike(peer_cfg) &&
diff --git a/src/charon/sa/tasks/ike_p2p.c b/src/charon/sa/tasks/ike_p2p.c
new file mode 100644
index 000000000..de5a2e30e
--- /dev/null
+++ b/src/charon/sa/tasks/ike_p2p.c
@@ -0,0 +1,851 @@
+/**
+ * @file ike_p2p.c
+ *
+ * @brief Implementation of the ike_p2p task.
+ *
+ */
+
+/*
+ * Copyright (C) 2007 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 "ike_p2p.h"
+
+#include <string.h>
+
+#include <daemon.h>
+#include <config/peer_cfg.h>
+#include <encoding/payloads/id_payload.h>
+#include <encoding/payloads/notify_payload.h>
+#include <encoding/payloads/endpoint_notify.h>
+#include <processing/jobs/mediation_job.h>
+
+#define P2P_SESSIONID_LEN 8
+#define P2P_SESSIONKEY_LEN 16
+
+// FIXME: proposed values
+#define P2P_SESSIONID_MIN_LEN 4
+#define P2P_SESSIONID_MAX_LEN 16
+#define P2P_SESSIONKEY_MIN_LEN 8
+#define P2P_SESSIONKEY_MAX_LEN 64
+
+
+typedef struct private_ike_p2p_t private_ike_p2p_t;
+
+/**
+ * Private members of a ike_p2p_t task.
+ */
+struct private_ike_p2p_t {
+	
+	/**
+	 * Public methods and task_t interface.
+	 */
+	ike_p2p_t public;
+	
+	/**
+	 * Assigned IKE_SA.
+	 */
+	ike_sa_t *ike_sa;
+	
+	/**
+	 * Are we the initiator?
+	 */
+	bool initiator;
+	
+	/**
+	 * Is this a mediation connection?
+	 */
+	bool mediation;
+	
+	/**
+	 * Is this the response from another peer?
+	 */
+	bool response;
+	
+	/**
+	 * Gathered endpoints
+	 */
+	linked_list_t *local_endpoints;
+	
+	/**
+	 * Parsed endpoints
+	 */
+	linked_list_t *remote_endpoints;
+	
+	/**
+	 * Did the peer request a callback?
+	 */
+	bool callback;
+	
+	/**
+	 * Did the connect fail?
+	 */
+	bool failed;
+	
+	/**
+	 * Was there anything wrong with the payloads?
+	 */
+	bool invalid_syntax;
+	
+	/**
+	 * The requested peer
+	 */
+	identification_t *peer_id;	
+	/**
+	 * Received ID used for connectivity checks
+	 */
+	chunk_t session_id;
+	
+	/**
+	 * Received key used for connectivity checks
+	 */
+	chunk_t session_key;
+	
+	/**
+	 * Peer config of the mediated connection
+	 */
+	peer_cfg_t *mediated_cfg;
+
+};
+
+// -----------------------------------------------------------------------------
+
+/**
+ * Adds a list of endpoints as notifies to a given message
+ */
+static void add_endpoints_to_message(message_t *message, linked_list_t *endpoints)
+{
+	iterator_t *iterator;
+	endpoint_notify_t *endpoint;
+	
+	iterator = endpoints->create_iterator(endpoints, TRUE);
+	while (iterator->iterate(iterator, (void**)&endpoint))
+	{
+		message->add_payload(message, (payload_t*)endpoint->build_notify(endpoint));
+	}
+	iterator->destroy(iterator);
+}
+
+/**
+ * Gathers endpoints and adds them to the current message
+ */
+static void gather_and_add_endpoints(private_ike_p2p_t *this, message_t *message)
+{
+	iterator_t *iterator;
+	host_t *addr, *host;
+	u_int16_t port;
+	
+	// get the port that is used to communicate with the ms
+	host = this->ike_sa->get_my_host(this->ike_sa);
+	port = host->get_port(host);
+	
+	iterator = charon->kernel_interface->create_address_iterator(
+												charon->kernel_interface);
+	while (iterator->iterate(iterator, (void**)&addr))
+	{
+		host = addr->clone(addr);
+		host->set_port(host, port);
+		
+		this->local_endpoints->insert_last(this->local_endpoints,
+				endpoint_notify_create_from_host(HOST, host, NULL));
+		
+		host->destroy(host);
+	}
+	iterator->destroy(iterator);
+	
+	host = this->ike_sa->get_server_reflexive_host(this->ike_sa);
+	if (host)
+	{
+		this->local_endpoints->insert_last(this->local_endpoints,
+				endpoint_notify_create_from_host(SERVER_REFLEXIVE, host,
+						this->ike_sa->get_my_host(this->ike_sa)));
+	}
+	
+	add_endpoints_to_message(message, this->local_endpoints);
+}
+
+/**
+ * read notifys from message and evaluate them
+ */
+static void process_payloads(private_ike_p2p_t *this, message_t *message)
+{
+	iterator_t *iterator;
+	payload_t *payload;
+
+	iterator = message->get_payload_iterator(message);
+	while (iterator->iterate(iterator, (void**)&payload))
+	{
+		if (payload->get_type(payload) != NOTIFY)
+		{
+			continue;
+		}
+		
+		notify_payload_t *notify = (notify_payload_t*)payload;
+		
+		switch (notify->get_notify_type(notify))
+		{
+			case P2P_CONNECT_FAILED:
+			{
+				DBG2(DBG_IKE, "received P2P_CONNECT_FAILED notify");
+				this->failed = TRUE;
+				break;
+			}
+			case P2P_MEDIATION:
+			{
+				DBG2(DBG_IKE, "received P2P_MEDIATION notify");
+				this->mediation = TRUE;
+				break;
+			}
+			case P2P_ENDPOINT:
+			{
+				endpoint_notify_t *endpoint = endpoint_notify_create_from_payload(notify);
+				if (!endpoint)
+				{
+					DBG1(DBG_IKE, "received invalid P2P_ENDPOINT notify");
+					break;
+				}
+				DBG2(DBG_IKE, "received P2P_ENDPOINT notify");
+				
+				this->remote_endpoints->insert_last(this->remote_endpoints, endpoint);
+				break;
+			}
+			case P2P_CALLBACK:
+			{
+				DBG2(DBG_IKE, "received P2P_CALLBACK notify");
+				this->callback = TRUE;
+				break;
+			}
+			case P2P_SESSIONID:
+			{
+				chunk_free(&this->session_id);
+				this->session_id = chunk_clone(notify->get_notification_data(notify));
+				DBG3(DBG_IKE, "received p2p_sessionid %B", &this->session_id);
+				break;
+			}
+			case P2P_SESSIONKEY:
+			{
+				chunk_free(&this->session_key);
+				this->session_key = chunk_clone(notify->get_notification_data(notify));
+				DBG4(DBG_IKE, "received p2p_sessionkey %B", &this->session_key);
+				break;
+			}
+			case P2P_RESPONSE:
+			{
+				DBG2(DBG_IKE, "received P2P_RESPONSE notify");
+				this->response = TRUE;
+				break;
+			}
+			default:
+				break;
+		}
+	}
+	iterator->destroy(iterator);
+}
+
+// -----------------------------------------------------------------------------
+
+/**
+ * Implementation of task_t.process for initiator
+ */
+static status_t build_i(private_ike_p2p_t *this, message_t *message)
+{
+	switch(message->get_exchange_type(message))
+	{
+		case IKE_SA_INIT:
+		{
+			peer_cfg_t *peer_cfg = this->ike_sa->get_peer_cfg(this->ike_sa);
+			if (peer_cfg->is_mediation(peer_cfg))
+			{
+				DBG2(DBG_IKE, "adding P2P_MEDIATION");
+				message->add_notify(message, FALSE, P2P_MEDIATION, chunk_empty);
+			}
+			else
+			{
+				return SUCCESS;
+			}
+			break;
+		}
+		case IKE_AUTH:
+		{
+			if (this->ike_sa->has_condition(this->ike_sa, COND_NAT_HERE))
+			{
+				endpoint_notify_t *endpoint = endpoint_notify_create_from_host(SERVER_REFLEXIVE, NULL, NULL);
+				message->add_payload(message, (payload_t*)endpoint->build_notify(endpoint));
+				endpoint->destroy(endpoint);
+			}
+			break;
+		}
+		case P2P_CONNECT:
+		{
+			id_payload_t *id_payload;
+			randomizer_t *rand = randomizer_create();
+			
+			id_payload = id_payload_create_from_identification(ID_PEER, this->peer_id);
+			message->add_payload(message, (payload_t*)id_payload);
+			
+			if (!this->response)
+			{
+				// only the initiator creates a session ID. the responder returns
+				// the session ID that it received from the initiator
+				if (rand->allocate_pseudo_random_bytes(rand,
+						P2P_SESSIONID_LEN, &this->session_id) != SUCCESS)
+				{
+					DBG1(DBG_IKE, "unable to generate session ID for P2P_CONNECT");		
+					rand->destroy(rand);
+					return FAILED;
+				}
+			}
+			
+			if (rand->allocate_pseudo_random_bytes(rand,
+					P2P_SESSIONKEY_LEN, &this->session_key) != SUCCESS)
+			{
+				DBG1(DBG_IKE, "unable to generate session key for P2P_CONNECT");
+				rand->destroy(rand);
+				return FAILED;
+			}
+			
+			rand->destroy(rand);
+			
+			message->add_notify(message, FALSE, P2P_SESSIONID, this->session_id);
+			message->add_notify(message, FALSE, P2P_SESSIONKEY, this->session_key);
+			
+			if (this->response)
+			{
+				message->add_notify(message, FALSE, P2P_RESPONSE, chunk_empty);
+			}
+			else
+			{
+				// FIXME: should we make that configurable
+				message->add_notify(message, FALSE, P2P_CALLBACK, chunk_empty);
+			}
+			
+			gather_and_add_endpoints(this, message);
+			
+			break;
+		}
+	}
+	
+	return NEED_MORE;
+}
+
+/**
+ * Implementation of task_t.process for responder
+ */
+static status_t process_r(private_ike_p2p_t *this, message_t *message)
+{
+	switch(message->get_exchange_type(message))
+	{
+		case P2P_CONNECT:
+		{
+			id_payload_t *id_payload;
+			id_payload = (id_payload_t*)message->get_payload(message, ID_PEER);
+			if (!id_payload)
+			{
+				DBG1(DBG_IKE, "received P2P_CONNECT without ID_PEER payload, aborting");
+				break;
+			}
+			this->peer_id = id_payload->get_identification(id_payload);
+			
+			process_payloads(this, message);
+			
+			if (this->callback)
+			{
+				DBG1(DBG_IKE, "received P2P_CALLBACK for '%D'", this->peer_id);
+				break;
+			}			
+			
+			if (!this->session_id.ptr)
+			{
+				DBG1(DBG_IKE, "received P2P_CONNECT without P2P_SESSIONID notify, aborting");
+				this->invalid_syntax = TRUE;
+				break;
+			}
+			
+			if (!this->session_key.ptr)
+			{
+				DBG1(DBG_IKE, "received P2P_CONNECT without P2P_SESSIONKEY notify, aborting");
+				this->invalid_syntax = TRUE;
+				break;
+			}
+			
+			if (!this->remote_endpoints->get_count(this->remote_endpoints))
+			{
+				DBG1(DBG_IKE, "received P2P_CONNECT without any P2P_ENDPOINT payloads, aborting");
+				this->invalid_syntax = TRUE;
+				break;
+			}
+			
+			DBG1(DBG_IKE, "received P2P_CONNECT");
+			
+			break;
+		}
+	}
+	
+	return NEED_MORE;
+}
+
+/**
+ * Implementation of task_t.build for responder
+ */
+static status_t build_r(private_ike_p2p_t *this, message_t *message)
+{
+	switch(message->get_exchange_type(message))
+	{
+		case P2P_CONNECT:
+		{
+			if (this->invalid_syntax)
+			{
+				message->add_notify(message, TRUE, INVALID_SYNTAX, chunk_empty);
+				break;
+			}
+			
+			if (this->callback)
+			{
+				charon->connect_manager->check_and_initiate(charon->connect_manager,
+						this->ike_sa->get_id(this->ike_sa),
+						this->ike_sa->get_my_id(this->ike_sa), this->peer_id);
+				return SUCCESS;
+			}
+			
+			if (this->response)
+			{
+				// FIXME: handle result of set_responder_data
+				// as initiator, upon receiving a response from another peer,
+				// update the checklist and start sending checks
+				charon->connect_manager->set_responder_data(charon->connect_manager,
+						this->session_id, this->session_key, this->remote_endpoints);
+			}
+			else
+			{
+				// FIXME: handle result of set_initiator_data
+				// as responder, create a checklist with the initiator's data
+				charon->connect_manager->set_initiator_data(charon->connect_manager,
+						this->peer_id, this->ike_sa->get_my_id(this->ike_sa),
+						this->session_id, this->session_key, this->remote_endpoints,
+						FALSE);
+				if (this->ike_sa->respond(this->ike_sa, this->peer_id,
+						this->session_id) != SUCCESS)
+				{
+					return FAILED;
+				}
+			}
+			
+			break;
+		}
+	}
+	return SUCCESS;
+}
+
+/**
+ * Implementation of task_t.process for initiator
+ */
+static status_t process_i(private_ike_p2p_t *this, message_t *message)
+{
+	switch(message->get_exchange_type(message))
+	{
+		case IKE_SA_INIT:
+		{
+			process_payloads(this, message);
+		
+			if (!this->mediation)
+			{
+				DBG1(DBG_IKE, "server did not return a P2P_MEDIATION, aborting");
+				return FAILED;
+			}
+	
+			return NEED_MORE;
+		}
+		case IKE_AUTH:
+		{
+			process_payloads(this, message);
+			
+			//FIXME: we should update the server reflexive endpoint somehow, if mobike notices a change 
+			
+			endpoint_notify_t *reflexive;
+			if (this->remote_endpoints->get_first(this->remote_endpoints, (void**)&reflexive) == SUCCESS &&
+					reflexive->get_type(reflexive) == SERVER_REFLEXIVE)
+			{//FIXME: should we accept this endpoint even if we did not send a request?
+				host_t *endpoint = reflexive->get_host(reflexive);
+				DBG2(DBG_IKE, "received server reflexive endpoint %#H", endpoint);
+				
+				this->ike_sa->set_server_reflexive_host(this->ike_sa, endpoint->clone(endpoint));
+			}
+			
+			// FIXME: what if it failed? e.g. AUTH failure
+			SIG(CHILD_UP_SUCCESS, "established mediation connection without CHILD_SA successfully");
+			
+			break;
+		}
+		case P2P_CONNECT:
+		{
+			process_payloads(this, message);
+			
+			if (this->failed)
+			{
+				DBG1(DBG_IKE, "peer '%D' is not online", this->peer_id);
+				// FIXME: notify the mediated connection (job?)
+				// FIXME: probably delete the created checklist, at least as responder
+			}
+			else
+			{
+				if (this->response)
+				{
+					// FIXME: handle result of set_responder_data
+					// as responder, we update the checklist and start sending checks
+					charon->connect_manager->set_responder_data(charon->connect_manager,
+							this->session_id, this->session_key, this->local_endpoints);
+				}
+				else
+				{
+					// FIXME: handle result of set_initiator_data
+					// as initiator, we create a checklist and set the initiator's data
+					charon->connect_manager->set_initiator_data(charon->connect_manager,
+						this->ike_sa->get_my_id(this->ike_sa), this->peer_id,
+						this->session_id, this->session_key, this->local_endpoints,
+						TRUE);
+				}
+			}
+			break;
+		}
+	}
+	return SUCCESS;
+}
+
+// -----------------------------------------------------------------------------
+
+/**
+ * Implementation of task_t.process for initiator (mediation server)
+ */
+static status_t build_i_ms(private_ike_p2p_t *this, message_t *message)
+{
+	switch(message->get_exchange_type(message))
+	{
+		case P2P_CONNECT:
+		{
+			id_payload_t *id_payload = id_payload_create_from_identification(ID_PEER, this->peer_id);
+			message->add_payload(message, (payload_t*)id_payload);
+			
+			if (this->callback)
+			{
+				message->add_notify(message, FALSE, P2P_CALLBACK, chunk_empty);
+			}
+			else
+			{
+				notify_payload_t *notify;
+				
+				if (this->response)
+				{
+					message->add_notify(message, FALSE, P2P_RESPONSE, chunk_empty);
+				}
+				
+				message->add_notify(message, FALSE, P2P_SESSIONID, this->session_id);
+				message->add_notify(message, FALSE, P2P_SESSIONKEY, this->session_key);
+				
+				add_endpoints_to_message(message, this->remote_endpoints);
+			}
+			
+			break;
+		}
+	}
+	
+	return NEED_MORE;
+}
+
+/**
+ * Implementation of task_t.process for responder (mediation server)
+ */
+static status_t process_r_ms(private_ike_p2p_t *this, message_t *message)
+{
+	switch(message->get_exchange_type(message))
+	{
+		case IKE_SA_INIT:
+		{
+			process_payloads(this, message);
+			return this->mediation ? NEED_MORE : SUCCESS;
+		}
+		case IKE_AUTH:
+		{
+			process_payloads(this, message);
+			break;
+		}
+		case P2P_CONNECT:
+		{
+			id_payload_t *id_payload;
+			id_payload = (id_payload_t*)message->get_payload(message, ID_PEER);
+			if (!id_payload)
+			{
+				DBG1(DBG_IKE, "received P2P_CONNECT without ID_PEER payload, aborting");
+				this->invalid_syntax = TRUE;
+				break;
+			}
+			
+			this->peer_id = id_payload->get_identification(id_payload);
+			
+			process_payloads(this, message);
+			
+			if (!this->session_id.ptr)
+			{
+				DBG1(DBG_IKE, "received P2P_CONNECT without P2P_SESSIONID notify, aborting");
+				this->invalid_syntax = TRUE;
+				break;
+			}
+			
+			if (!this->session_key.ptr)
+			{
+				DBG1(DBG_IKE, "received P2P_CONNECT without P2P_SESSIONKEY notify, aborting");
+				this->invalid_syntax = TRUE;
+				break;
+			}
+			
+			if (!this->remote_endpoints->get_count(this->remote_endpoints))
+			{
+				DBG1(DBG_IKE, "received P2P_CONNECT without any P2P_ENDPOINT payloads, aborting");
+				this->invalid_syntax = TRUE;
+				break;
+			}
+			
+			break;
+		}
+	}
+	
+	return NEED_MORE;
+}
+
+/**
+ * Implementation of task_t.build for responder (mediation server)
+ */
+static status_t build_r_ms(private_ike_p2p_t *this, message_t *message)
+{
+	switch(message->get_exchange_type(message))
+	{
+		case IKE_SA_INIT:
+		{
+			message->add_notify(message, FALSE, P2P_MEDIATION, chunk_empty);
+			return NEED_MORE;
+		}
+		case IKE_AUTH:
+		{
+			endpoint_notify_t *endpoint;
+			if (this->remote_endpoints->get_first(this->remote_endpoints, (void**)&endpoint) == SUCCESS &&
+					endpoint->get_type(endpoint) == SERVER_REFLEXIVE)
+			{
+				host_t *host = this->ike_sa->get_other_host(this->ike_sa);
+				
+				DBG2(DBG_IKE, "received request for a server reflexive endpoint "
+						"sending: %#H", host);
+				
+				endpoint = endpoint_notify_create_from_host(SERVER_REFLEXIVE, host, NULL);								
+				message->add_payload(message, (payload_t*)endpoint->build_notify(endpoint));
+			}
+			
+			charon->mediation_manager->update_sa_id(charon->mediation_manager,
+					this->ike_sa->get_other_id(this->ike_sa),
+					this->ike_sa->get_id(this->ike_sa));
+			
+			SIG(CHILD_UP_SUCCESS, "established mediation connection without CHILD_SA successfully");
+			
+			break;
+		}
+		case P2P_CONNECT:
+		{	
+			if (this->invalid_syntax)
+			{
+				message->add_notify(message, TRUE, INVALID_SYNTAX, chunk_empty);
+				break;
+			}
+			
+			ike_sa_id_t *peer_sa;
+			if (this->callback)
+			{
+				peer_sa = charon->mediation_manager->check_and_register(charon->mediation_manager,
+						this->peer_id, this->ike_sa->get_other_id(this->ike_sa));
+			}
+			else
+			{
+				peer_sa = charon->mediation_manager->check(charon->mediation_manager,
+						this->peer_id);
+			}
+			
+			if (!peer_sa)
+			{
+				// the peer is not online
+				message->add_notify(message, TRUE, P2P_CONNECT_FAILED, chunk_empty);
+				break;
+			}
+			
+			job_t *job = (job_t*)mediation_job_create(this->peer_id,
+					this->ike_sa->get_other_id(this->ike_sa), this->session_id,
+					this->session_key, this->remote_endpoints, this->response);
+			charon->processor->queue_job(charon->processor, job);
+			
+			break;
+		}
+	}
+	return SUCCESS;
+}
+
+/**
+ * Implementation of task_t.process for initiator (mediation server)
+ */
+static status_t process_i_ms(private_ike_p2p_t *this, message_t *message)
+{
+	switch(message->get_exchange_type(message))
+	{
+		case P2P_CONNECT:
+		{
+			break;
+		}
+	}
+	return SUCCESS;
+}
+
+// -----------------------------------------------------------------------------
+
+/**
+ * Implementation of ike_p2p.connect
+ */
+static void p2p_connect(private_ike_p2p_t *this, identification_t *peer_id)
+{
+	this->peer_id = peer_id->clone(peer_id);
+}
+
+/**
+ * Implementation of ike_p2p.respond
+ */
+static void p2p_respond(private_ike_p2p_t *this, identification_t *peer_id, 
+		chunk_t session_id)
+{
+	this->peer_id = peer_id->clone(peer_id);
+	this->session_id = chunk_clone(session_id);
+	this->response = TRUE;
+}
+
+/**
+ * Implementation of ike_p2p.callback
+ */
+static void p2p_callback(private_ike_p2p_t *this, identification_t *peer_id)
+{
+	this->peer_id = peer_id->clone(peer_id);
+	this->callback = TRUE;
+}
+
+/**
+ * Implementation of ike_p2p.relay
+ */
+static void relay(private_ike_p2p_t *this, identification_t *requester, chunk_t session_id,
+		chunk_t session_key, linked_list_t *endpoints, bool response)
+{
+	this->peer_id = requester->clone(requester);
+	this->session_id = chunk_clone(session_id);
+	this->session_key = chunk_clone(session_key);
+	this->remote_endpoints = endpoints->clone_offset(endpoints, offsetof(endpoint_notify_t, clone));
+	this->response = response;
+}
+
+/**
+ * Implementation of task_t.get_type
+ */
+static task_type_t get_type(private_ike_p2p_t *this)
+{
+	return IKE_P2P;
+}
+
+/**
+ * Implementation of task_t.migrate
+ */
+static void migrate(private_ike_p2p_t *this, ike_sa_t *ike_sa)
+{
+	this->ike_sa = ike_sa;
+}
+
+/**
+ * Implementation of task_t.destroy
+ */
+static void destroy(private_ike_p2p_t *this)
+{
+	DESTROY_IF(this->peer_id);
+	
+	chunk_free(&this->session_id);
+	chunk_free(&this->session_key);
+	
+	this->local_endpoints->destroy_offset(this->local_endpoints, offsetof(endpoint_notify_t, destroy));
+	this->remote_endpoints->destroy_offset(this->remote_endpoints, offsetof(endpoint_notify_t, destroy));
+	
+	DESTROY_IF(this->mediated_cfg);
+	free(this);
+}
+
+/*
+ * Described in header.
+ */
+ike_p2p_t *ike_p2p_create(ike_sa_t *ike_sa, bool initiator)
+{
+	private_ike_p2p_t *this = malloc_thing(private_ike_p2p_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;
+	
+	ike_sa_id_t *id = ike_sa->get_id(ike_sa);
+	if (id->is_initiator(id))
+	{
+		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;
+		}
+	}
+	else
+	{
+		// mediation server
+		if (initiator)
+		{
+			this->public.task.build = (status_t(*)(task_t*,message_t*))build_i_ms;
+			this->public.task.process = (status_t(*)(task_t*,message_t*))process_i_ms;
+		}
+		else
+		{
+			this->public.task.build = (status_t(*)(task_t*,message_t*))build_r_ms;
+			this->public.task.process = (status_t(*)(task_t*,message_t*))process_r_ms;
+		}
+	}
+	
+	this->public.connect = (void(*)(ike_p2p_t*,identification_t*))p2p_connect;
+	this->public.respond = (void(*)(ike_p2p_t*,identification_t*,chunk_t))p2p_respond;
+	this->public.callback = (void(*)(ike_p2p_t*,identification_t*))p2p_callback;
+	this->public.relay = (void(*)(ike_p2p_t*,identification_t*,chunk_t,chunk_t,linked_list_t*,bool))relay;
+	
+	this->ike_sa = ike_sa;
+	this->initiator = initiator;
+	
+	this->peer_id = NULL;
+	this->session_id = chunk_empty;
+	this->session_key = chunk_empty;
+	this->local_endpoints = linked_list_create();
+	this->remote_endpoints = linked_list_create();
+	this->mediation = FALSE;
+	this->response = FALSE;
+	this->callback = FALSE;
+	this->failed = FALSE;
+	this->invalid_syntax = FALSE;
+	
+	this->mediated_cfg = NULL;
+	
+	return &this->public;
+}
diff --git a/src/charon/sa/tasks/ike_p2p.h b/src/charon/sa/tasks/ike_p2p.h
new file mode 100644
index 000000000..327ac49d8
--- /dev/null
+++ b/src/charon/sa/tasks/ike_p2p.h
@@ -0,0 +1,110 @@
+/**
+ * @file ike_p2p.h
+ * 
+ * @brief Interface ike_p2p_t.
+ * 
+ */
+
+/*
+ * Copyright (C) 2007 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.
+ */
+
+#ifndef IKE_P2P_H_
+#define IKE_P2P_H_
+
+typedef struct ike_p2p_t ike_p2p_t;
+
+#include <library.h>
+#include <sa/ike_sa.h>
+#include <sa/tasks/task.h>
+
+/**
+ * @brief Task of type IKE_P2P, detects and handles P2P-NAT-T extensions.
+ *
+ * This tasks handles the P2P_MEDIATION notify exchange to setup a mediation
+ * connection, allows to initiate mediated connections using P2P_CONNECT
+ * exchanges and to request reflexive addresses from the mediation server using
+ * P2P_ENDPOINT notifies.
+ * 
+ * @note This task has to be activated before the IKE_AUTH task, because that
+ * task generates the IKE_SA_INIT message so that no more payloads can be added
+ * to it afterwards.
+ *
+ * @b Constructors:
+ *  - ike_p2p_create()
+ * 
+ * @ingroup tasks
+ */
+struct ike_p2p_t {
+
+	/**
+	 * Implements the task_t interface
+	 */
+	task_t task;
+	
+	/**
+	 * @brief Initiates a connection with another peer (i.e. sends a P2P_CONNECT
+	 * to the mediation server)
+	 *
+	 * @param this				object
+	 * @param peer_id			ID of the other peer (gets cloned)
+	 */
+	void (*connect)(ike_p2p_t *this, identification_t *peer_id);
+	
+	/**
+	 * @brief Responds to a P2P_CONNECT from another peer (i.e. sends a P2P_CONNECT
+	 * to the mediation server)
+	 * 
+	 * @param this				object
+	 * @param peer_id			ID of the other peer (gets cloned)
+	 * @param session_id		the session ID as provided by the initiator (gets cloned)
+	 */
+	void (*respond)(ike_p2p_t *this, identification_t *peer_id, chunk_t session_id);
+	
+	/**
+	 * @brief Sends a P2P_CALLBACK to a peer that previously requested another peer.
+	 * 
+	 * @param this				object
+	 * @param peer_id			ID of the other peer (gets cloned)
+	 */
+	void (*callback)(ike_p2p_t *this, identification_t *peer_id);
+	
+	/**
+	 * @brief Relays data to another peer (i.e. sends a P2P_CONNECT to the peer)
+	 * 
+	 * Data gets cloned.
+	 * 
+	 * @param this				object
+	 * @param requester			ID of the requesting peer
+	 * @param session_id		content of the P2P_SESSIONID notify
+	 * @param session_key		content of the P2P_SESSIONKEY notify
+	 * @param endpoints			endpoints
+	 * @param response			TRUE if this is a response
+	 */
+	void (*relay)(ike_p2p_t *this, identification_t *requester, chunk_t session_id,
+			chunk_t session_key, linked_list_t *endpoints, bool response);
+
+};
+
+/**
+ * @brief Create a new ike_p2p task.
+ *
+ * @param ike_sa		IKE_SA this task works for
+ * @param initiator		TRUE if taks is initiated by us
+ * @return			  	ike_p2p task to handle by the task_manager
+ */
+ike_p2p_t *ike_p2p_create(ike_sa_t *ike_sa, bool initiator);
+
+
+#endif /*IKE_P2P_H_*/
diff --git a/src/charon/sa/tasks/task.c b/src/charon/sa/tasks/task.c
index 713403d47..e9d0c4da1 100644
--- a/src/charon/sa/tasks/task.c
+++ b/src/charon/sa/tasks/task.c
@@ -6,6 +6,7 @@
  */
 
 /*
+ * Copyright (C) 2007 Tobias Brunner
  * Copyright (C) 2007 Martin Willi
  * Hochschule fuer Technik Rapperswil
  *
@@ -33,6 +34,9 @@ ENUM(task_type_names, IKE_INIT, CHILD_REKEY,
 	"IKE_REAUTH",
 	"IKE_DELETE",
 	"IKE_DPD",
+#ifdef P2P
+	"IKE_P2P",
+#endif /* P2P */
 	"CHILD_CREATE",
 	"CHILD_DELETE",
 	"CHILD_REKEY",
diff --git a/src/charon/sa/tasks/task.h b/src/charon/sa/tasks/task.h
index ff60ea816..dd2bb8a83 100644
--- a/src/charon/sa/tasks/task.h
+++ b/src/charon/sa/tasks/task.h
@@ -6,6 +6,7 @@
  */
 
 /*
+ * Copyright (C) 2007 Tobias Brunner
  * Copyright (C) 2006 Martin Willi
  * Hochschule fuer Technik Rapperswil
  *
@@ -56,6 +57,10 @@ enum task_type_t {
 	IKE_DELETE,
 	/** liveness check */
 	IKE_DPD,
+#ifdef P2P
+	/** handle P2P-NAT-T stuff */
+	IKE_P2P,
+#endif /* P2P */
 	/** establish a CHILD_SA within an IKE_SA */
 	CHILD_CREATE,
 	/** delete an established CHILD_SA */
diff --git a/src/starter/args.c b/src/starter/args.c
index 5d69386d7..13c7bb3a7 100644
--- a/src/starter/args.c
+++ b/src/starter/args.c
@@ -1,4 +1,5 @@
 /* automatic handling of confread struct arguments
+ * Copyright (C) 2007 Tobias Brunner
  * Copyright (C) 2006 Andreas Steffen
  * Hochschule fuer Technik Rapperswil, Switzerland
  *
@@ -210,6 +211,9 @@ static const token_info_t token_info[] =
     { ARG_ENUM, offsetof(starter_conn_t, dpd_action), LST_dpd_action               },
     { ARG_MISC, 0, NULL  /* KW_MODECONFIG */                                       },
     { ARG_MISC, 0, NULL  /* KW_XAUTH */                                            },
+    { ARG_ENUM, offsetof(starter_conn_t, p2p_mediation), LST_bool                  },
+    { ARG_STR,  offsetof(starter_conn_t, p2p_mediated_by), NULL                    },
+    { ARG_STR,  offsetof(starter_conn_t, p2p_peerid), NULL                         },
 
     /* ca section keywords */
     { ARG_STR,  offsetof(starter_ca_t, name), NULL                                 },
diff --git a/src/starter/confread.h b/src/starter/confread.h
index 912af4945..ec1076e53 100644
--- a/src/starter/confread.h
+++ b/src/starter/confread.h
@@ -1,5 +1,8 @@
 /* strongSwan IPsec config file parser
- * Copyright (C) 2001-2002 Mathieu Lafon - Arkoon Network Security
+ * Copyright (C) 2007 Tobias Brunner
+ * Hochschule fuer Technik Rapperswil
+ * Copyright (C) 2001-2002 Mathieu Lafon
+ * Arkoon Network Security
  *
  * 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
@@ -125,6 +128,10 @@ struct starter_conn {
 	time_t		dpd_timeout;
 	dpd_action_t	dpd_action;
 	int		dpd_count;
+	
+	bool		p2p_mediation;
+	char		*p2p_mediated_by;
+	char		*p2p_peerid;
 
 	starter_conn_t *next;
 };
diff --git a/src/starter/ipsec.conf.5 b/src/starter/ipsec.conf.5
index a54a6cc11..8e6624f21 100644
--- a/src/starter/ipsec.conf.5
+++ b/src/starter/ipsec.conf.5
@@ -779,6 +779,36 @@ Accepted values are
 and
 .B client
 (the default).
+
+.SS "CONN PARAMETERS: PEER-TO-PEER"
+The following parameters are relevant to Peer-to-Peer NAT-T operation
+only.
+.TP 14
+.B p2p_mediation
+whether this connection is a P2P mediation connection, ie. whether this
+connection is used to mediate other connections.  Mediation connections
+create no child SA. Acceptable values are
+.B no
+(the default) and
+.BR yes .
+.TP
+.B p2p_mediated_by
+the name of the connection to mediate this connection through.  If given,
+the connection will be mediated through the named mediation connection.
+The mediation connection must set
+.BR p2p_mediation=yes .
+.TP
+.B p2p_peerid
+ID as which the peer is known to the mediation server, ie. which the other
+end of this connection uses as its
+.B leftid
+on its connection to the mediation server.  This is the ID we request the
+mediation server to mediate us with.  If
+.B p2p_peerid
+is not given, the
+.B rightid
+of this connection will be used as peer ID.
+
 .SH "CA SECTIONS"
 This are optional sections that can be used to assign special
 parameters to a Certification Authority (CA). These parameters are not 
diff --git a/src/starter/keywords.h b/src/starter/keywords.h
index bb0606c2f..acfc76630 100644
--- a/src/starter/keywords.h
+++ b/src/starter/keywords.h
@@ -1,4 +1,5 @@
 /* strongSwan keywords
+ * Copyright (C) 2007 Tobias Brunner
  * Copyright (C) 2005 Andreas Steffen
  * Hochschule fuer Technik Rapperswil, Switzerland
  *
@@ -87,9 +88,12 @@ typedef enum {
     KW_DPDACTION,
     KW_MODECONFIG,
     KW_XAUTH,
+    KW_P2P_MEDIATION,
+    KW_P2P_MEDIATED_BY,
+    KW_P2P_PEERID,
 
 #define KW_CONN_FIRST	KW_CONN_SETUP
-#define KW_CONN_LAST	KW_XAUTH
+#define KW_CONN_LAST	KW_P2P_PEERID
 
    /* ca section keywords */
     KW_CA_NAME,
diff --git a/src/starter/keywords.txt b/src/starter/keywords.txt
index e4a9bd4ab..10f7cad1a 100644
--- a/src/starter/keywords.txt
+++ b/src/starter/keywords.txt
@@ -1,5 +1,6 @@
 %{
 /* strongSwan keywords
+ * Copyright (C) 2007 Tobias Brunner
  * Copyright (C) 2005 Andreas Steffen
  * Hochschule fuer Technik Rapperswil, Switzerland
  *
@@ -76,6 +77,9 @@ dpdtimeout,        KW_DPDTIMEOUT
 dpdaction,         KW_DPDACTION
 modeconfig,        KW_MODECONFIG
 xauth,             KW_XAUTH
+p2p_mediation,     KW_P2P_MEDIATION
+p2p_mediated_by,   KW_P2P_MEDIATED_BY
+p2p_peerid,        KW_P2P_PEERID
 cacert,            KW_CACERT
 ldaphost,          KW_LDAPHOST
 ldapbase,          KW_LDAPBASE
diff --git a/src/starter/starterstroke.c b/src/starter/starterstroke.c
index 006cf1a21..eeeb2f5b0 100644
--- a/src/starter/starterstroke.c
+++ b/src/starter/starterstroke.c
@@ -1,5 +1,7 @@
 /* Stroke for charon is the counterpart to whack from pluto
- * Copyright (C) 2006 Martin Willi - Hochschule fuer Technik Rapperswil
+ * Copyright (C) 2007 Tobias Brunner
+ * Copyright (C) 2006 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
@@ -233,6 +235,9 @@ int starter_stroke_add_conn(starter_conn_t *conn)
 	msg.add_conn.algorithms.esp = push_string(&msg, conn->esp);
 	msg.add_conn.dpd.delay = conn->dpd_delay;
 	msg.add_conn.dpd.action = conn->dpd_action;
+	msg.add_conn.p2p.mediation = conn->p2p_mediation;
+	msg.add_conn.p2p.mediated_by = push_string(&msg, conn->p2p_mediated_by);
+	msg.add_conn.p2p.peerid = push_string(&msg, conn->p2p_peerid);
 
 	starter_stroke_add_end(&msg, &msg.add_conn.me, &conn->left);
 	starter_stroke_add_end(&msg, &msg.add_conn.other, &conn->right);
diff --git a/src/stroke/stroke.c b/src/stroke/stroke.c
index d984f66ab..242a3b3de 100644
--- a/src/stroke/stroke.c
+++ b/src/stroke/stroke.c
@@ -1,5 +1,7 @@
 /* Stroke for charon is the counterpart to whack from pluto
- * Copyright (C) 2006 Martin Willi - Hochschule fuer Technik Rapperswil
+ * Copyright (C) 2007 Tobias Brunner
+ * Copyright (C) 2006 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
@@ -125,6 +127,10 @@ static int add_connection(char *name,
 	msg.add_conn.dpd.delay = 0;
 	msg.add_conn.dpd.action = 1;
 	
+	msg.add_conn.p2p.mediation = 0;
+	msg.add_conn.p2p.mediated_by = NULL;
+	msg.add_conn.p2p.peerid = NULL;
+	
 	msg.add_conn.me.id = push_string(&msg, my_id);
 	msg.add_conn.me.address = push_string(&msg, my_addr);
 	msg.add_conn.me.subnet = push_string(&msg, my_net);
diff --git a/src/stroke/stroke.h b/src/stroke/stroke.h
index 46bd12965..73a1e14fe 100644
--- a/src/stroke/stroke.h
+++ b/src/stroke/stroke.h
@@ -200,6 +200,11 @@ struct stroke_msg_t {
 				time_t delay;
 				int action;
 			} dpd;
+			struct {
+				int mediation;
+				char *mediated_by;
+				char *peerid;
+			} p2p;
 			stroke_end_t me, other;
 		} add_conn;