1 files changed, 670 insertions, 0 deletions

diff --git a/src/libcharon/sa/ikev2/tasks/ike_mobike.c b/src/libcharon/sa/ikev2/tasks/ike_mobike.c
new file mode 100644
index 000000000..ae3526f42
--- /dev/null
+++ b/src/libcharon/sa/ikev2/tasks/ike_mobike.c
@@ -0,0 +1,670 @@
+/*
+ * Copyright (C) 2010-2012 Tobias Brunner
+ * Copyright (C) 2007 Martin Willi
+ * Hochschule fuer Technik Rapperswil
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ */
+
+#include "ike_mobike.h"
+
+#include <string.h>
+
+#include <hydra.h>
+#include <daemon.h>
+#include <sa/ikev2/tasks/ike_natd.h>
+#include <encoding/payloads/notify_payload.h>
+
+#define COOKIE2_SIZE 16
+#define MAX_ADDITIONAL_ADDRS 8
+
+typedef struct private_ike_mobike_t private_ike_mobike_t;
+
+/**
+ * Private members of a ike_mobike_t task.
+ */
+struct private_ike_mobike_t {
+
+	/**
+	 * Public methods and task_t interface.
+	 */
+	ike_mobike_t public;
+
+	/**
+	 * Assigned IKE_SA.
+	 */
+	ike_sa_t *ike_sa;
+
+	/**
+	 * Are we the initiator?
+	 */
+	bool initiator;
+
+	/**
+	 * cookie2 value to verify new addresses
+	 */
+	chunk_t cookie2;
+
+	/**
+	 * NAT discovery reusing the TASK_IKE_NATD task
+	 */
+	ike_natd_t *natd;
+
+	/**
+	 * use task to update addresses
+	 */
+	bool update;
+
+	/**
+	 * do routability check
+	 */
+	bool check;
+
+	/**
+	 * include address list update
+	 */
+	bool address;
+
+	/**
+	 * additional addresses got updated
+	 */
+	bool addresses_updated;
+};
+
+/**
+ * read notifys from message and evaluate them
+ */
+static void process_payloads(private_ike_mobike_t *this, message_t *message)
+{
+	enumerator_t *enumerator;
+	payload_t *payload;
+	bool first = TRUE;
+
+	enumerator = message->create_payload_enumerator(message);
+	while (enumerator->enumerate(enumerator, &payload))
+	{
+		int family = AF_INET;
+		notify_payload_t *notify;
+		chunk_t data;
+		host_t *host;
+
+		if (payload->get_type(payload) != NOTIFY)
+		{
+			continue;
+		}
+		notify = (notify_payload_t*)payload;
+		switch (notify->get_notify_type(notify))
+		{
+			case MOBIKE_SUPPORTED:
+			{
+				peer_cfg_t *peer_cfg;
+
+				peer_cfg = this->ike_sa->get_peer_cfg(this->ike_sa);
+				if (!this->initiator &&
+					peer_cfg && !peer_cfg->use_mobike(peer_cfg))
+				{
+					DBG1(DBG_IKE, "peer supports MOBIKE, but disabled in config");
+				}
+				else
+				{
+					DBG1(DBG_IKE, "peer supports MOBIKE");
+					this->ike_sa->enable_extension(this->ike_sa, EXT_MOBIKE);
+				}
+				break;
+			}
+			case COOKIE2:
+			{
+				chunk_free(&this->cookie2);
+				this->cookie2 = chunk_clone(notify->get_notification_data(notify));
+				break;
+			}
+			case ADDITIONAL_IP6_ADDRESS:
+			{
+				family = AF_INET6;
+				/* fall through */
+			}
+			case ADDITIONAL_IP4_ADDRESS:
+			{
+				if (first)
+				{	/* an ADDITIONAL_*_ADDRESS means replace, so flush once */
+					this->ike_sa->clear_peer_addresses(this->ike_sa);
+					first = FALSE;
+					/* add the peer's current address to the list */
+					host = message->get_source(message);
+					this->ike_sa->add_peer_address(this->ike_sa,
+												   host->clone(host));
+				}
+				data = notify->get_notification_data(notify);
+				host = host_create_from_chunk(family, data, 0);
+				DBG2(DBG_IKE, "got additional MOBIKE peer address: %H", host);
+				this->ike_sa->add_peer_address(this->ike_sa, host);
+				this->addresses_updated = TRUE;
+				break;
+			}
+			case UPDATE_SA_ADDRESSES:
+			{
+				this->update = TRUE;
+				break;
+			}
+			case NO_ADDITIONAL_ADDRESSES:
+			{
+				this->ike_sa->clear_peer_addresses(this->ike_sa);
+				/* add the peer's current address to the list */
+				host = message->get_source(message);
+				this->ike_sa->add_peer_address(this->ike_sa, host->clone(host));
+				this->addresses_updated = TRUE;
+				break;
+			}
+			case NAT_DETECTION_SOURCE_IP:
+			case NAT_DETECTION_DESTINATION_IP:
+			{
+				/* NAT check in this MOBIKE exchange, create subtask for it */
+				if (this->natd == NULL)
+				{
+					this->natd = ike_natd_create(this->ike_sa, this->initiator);
+				}
+				break;
+			}
+			default:
+				break;
+		}
+	}
+	enumerator->destroy(enumerator);
+}
+
+/**
+ * Add ADDITIONAL_*_ADDRESS notifys depending on our address list
+ */
+static void build_address_list(private_ike_mobike_t *this, message_t *message)
+{
+	enumerator_t *enumerator;
+	host_t *host, *me;
+	notify_type_t type;
+	int added = 0;
+
+	me = this->ike_sa->get_my_host(this->ike_sa);
+	enumerator = hydra->kernel_interface->create_address_enumerator(
+									hydra->kernel_interface, ADDR_TYPE_REGULAR);
+	while (enumerator->enumerate(enumerator, (void**)&host))
+	{
+		if (me->ip_equals(me, host))
+		{	/* "ADDITIONAL" means do not include IKE_SAs host */
+			continue;
+		}
+		switch (host->get_family(host))
+		{
+			case AF_INET:
+				type = ADDITIONAL_IP4_ADDRESS;
+				break;
+			case AF_INET6:
+				type = ADDITIONAL_IP6_ADDRESS;
+				break;
+			default:
+				continue;
+		}
+		message->add_notify(message, FALSE, type, host->get_address(host));
+		if (++added >= MAX_ADDITIONAL_ADDRS)
+		{	/* limit number of notifys, some implementations do not like too
+			 * many of them (f.e. strongSwan ;-) */
+			break;
+		}
+	}
+	if (!added)
+	{
+		message->add_notify(message, FALSE, NO_ADDITIONAL_ADDRESSES, chunk_empty);
+	}
+	enumerator->destroy(enumerator);
+}
+
+/**
+ * build a cookie and add it to the message
+ */
+static bool build_cookie(private_ike_mobike_t *this, message_t *message)
+{
+	rng_t *rng;
+
+	chunk_free(&this->cookie2);
+	rng = lib->crypto->create_rng(lib->crypto, RNG_STRONG);
+	if (!rng || !rng->allocate_bytes(rng, COOKIE2_SIZE, &this->cookie2))
+	{
+		DESTROY_IF(rng);
+		return FALSE;
+	}
+	message->add_notify(message, FALSE, COOKIE2, this->cookie2);
+	rng->destroy(rng);
+	return TRUE;
+}
+
+/**
+ * update addresses of associated CHILD_SAs
+ */
+static void update_children(private_ike_mobike_t *this)
+{
+	enumerator_t *enumerator;
+	child_sa_t *child_sa;
+	linked_list_t *vips;
+	host_t *host;
+
+	vips = linked_list_create();
+
+	enumerator = this->ike_sa->create_virtual_ip_enumerator(this->ike_sa, TRUE);
+	while (enumerator->enumerate(enumerator, &host))
+	{
+		vips->insert_last(vips, host);
+	}
+	enumerator->destroy(enumerator);
+
+	enumerator = this->ike_sa->create_child_sa_enumerator(this->ike_sa);
+	while (enumerator->enumerate(enumerator, (void**)&child_sa))
+	{
+		if (child_sa->update(child_sa,
+				this->ike_sa->get_my_host(this->ike_sa),
+				this->ike_sa->get_other_host(this->ike_sa), vips,
+				this->ike_sa->has_condition(this->ike_sa,
+											COND_NAT_ANY)) == NOT_SUPPORTED)
+		{
+			this->ike_sa->rekey_child_sa(this->ike_sa,
+					child_sa->get_protocol(child_sa),
+					child_sa->get_spi(child_sa, TRUE));
+		}
+	}
+	enumerator->destroy(enumerator);
+
+	vips->destroy(vips);
+}
+
+/**
+ * Apply the port of the old host, if its ip equals the new, use port otherwise.
+ */
+static void apply_port(host_t *host, host_t *old, u_int16_t port, bool local)
+{
+	if (host->ip_equals(host, old))
+	{
+		port = old->get_port(old);
+	}
+	else if (local && port == charon->socket->get_port(charon->socket, FALSE))
+	{
+		port = charon->socket->get_port(charon->socket, TRUE);
+	}
+	else if (!local && port == IKEV2_UDP_PORT)
+	{
+		port = IKEV2_NATT_PORT;
+	}
+	host->set_port(host, port);
+}
+
+METHOD(ike_mobike_t, transmit, void,
+	   private_ike_mobike_t *this, packet_t *packet)
+{
+	host_t *me, *other, *me_old, *other_old;
+	enumerator_t *enumerator;
+	ike_cfg_t *ike_cfg;
+	packet_t *copy;
+
+	if (!this->check)
+	{
+		return;
+	}
+
+	me_old = this->ike_sa->get_my_host(this->ike_sa);
+	other_old = this->ike_sa->get_other_host(this->ike_sa);
+	ike_cfg = this->ike_sa->get_ike_cfg(this->ike_sa);
+
+	enumerator = this->ike_sa->create_peer_address_enumerator(this->ike_sa);
+	while (enumerator->enumerate(enumerator, (void**)&other))
+	{
+		me = hydra->kernel_interface->get_source_addr(
+										hydra->kernel_interface, other, NULL);
+		if (me)
+		{
+			if (me->get_family(me) != other->get_family(other))
+			{
+				me->destroy(me);
+				continue;
+			}
+			/* reuse port for an active address, 4500 otherwise */
+			apply_port(me, me_old, ike_cfg->get_my_port(ike_cfg), TRUE);
+			other = other->clone(other);
+			apply_port(other, other_old, ike_cfg->get_other_port(ike_cfg), FALSE);
+			DBG1(DBG_IKE, "checking path %#H - %#H", me, other);
+			copy = packet->clone(packet);
+			copy->set_source(copy, me);
+			copy->set_destination(copy, other);
+			charon->sender->send(charon->sender, copy);
+		}
+	}
+	enumerator->destroy(enumerator);
+}
+
+METHOD(task_t, build_i, status_t,
+	   private_ike_mobike_t *this, message_t *message)
+{
+	if (message->get_exchange_type(message) == IKE_AUTH &&
+		message->get_message_id(message) == 1)
+	{	/* only in first IKE_AUTH */
+		message->add_notify(message, FALSE, MOBIKE_SUPPORTED, chunk_empty);
+		build_address_list(this, message);
+	}
+	else if (message->get_exchange_type(message) == INFORMATIONAL)
+	{
+		host_t *old, *new;
+
+		/* we check if the existing address is still valid */
+		old = message->get_source(message);
+		new = hydra->kernel_interface->get_source_addr(hydra->kernel_interface,
+										message->get_destination(message), old);
+		if (new)
+		{
+			if (!new->ip_equals(new, old))
+			{
+				new->set_port(new, old->get_port(old));
+				message->set_source(message, new);
+			}
+			else
+			{
+				new->destroy(new);
+			}
+		}
+		if (this->update)
+		{
+			message->add_notify(message, FALSE, UPDATE_SA_ADDRESSES,
+								chunk_empty);
+			if (!build_cookie(this, message))
+			{
+				return FAILED;
+			}
+			update_children(this);
+		}
+		if (this->address && !this->check)
+		{
+			build_address_list(this, message);
+		}
+		if (this->natd)
+		{
+			this->natd->task.build(&this->natd->task, message);
+		}
+	}
+	return NEED_MORE;
+}
+
+METHOD(task_t, process_r, status_t,
+	   private_ike_mobike_t *this, message_t *message)
+{
+	if (message->get_exchange_type(message) == IKE_AUTH &&
+		message->get_message_id(message) == 1)
+	{	/* only first IKE_AUTH */
+		process_payloads(this, message);
+	}
+	else if (message->get_exchange_type(message) == INFORMATIONAL)
+	{
+		process_payloads(this, message);
+		if (this->update)
+		{
+			host_t *me, *other;
+
+			me = message->get_destination(message);
+			other = message->get_source(message);
+			this->ike_sa->set_my_host(this->ike_sa, me->clone(me));
+			this->ike_sa->set_other_host(this->ike_sa, other->clone(other));
+		}
+
+		if (this->natd)
+		{
+			this->natd->task.process(&this->natd->task, message);
+		}
+		if (this->addresses_updated && this->ike_sa->has_condition(this->ike_sa,
+												COND_ORIGINAL_INITIATOR))
+		{
+			host_t *other = message->get_source(message);
+			host_t *other_old = this->ike_sa->get_other_host(this->ike_sa);
+			if (!other->equals(other, other_old))
+			{
+				DBG1(DBG_IKE, "remote address changed from %H to %H", other_old,
+					 other);
+				this->ike_sa->set_other_host(this->ike_sa, other->clone(other));
+				this->update = TRUE;
+			}
+		}
+	}
+	return NEED_MORE;
+}
+
+METHOD(task_t, build_r, status_t,
+	   private_ike_mobike_t *this, message_t *message)
+{
+	if (message->get_exchange_type(message) == IKE_AUTH &&
+		this->ike_sa->get_state(this->ike_sa) == IKE_ESTABLISHED)
+	{
+		if (this->ike_sa->supports_extension(this->ike_sa, EXT_MOBIKE))
+		{
+			message->add_notify(message, FALSE, MOBIKE_SUPPORTED, chunk_empty);
+			build_address_list(this, message);
+		}
+		return SUCCESS;
+	}
+	else if (message->get_exchange_type(message) == INFORMATIONAL)
+	{
+		if (this->natd)
+		{
+			this->natd->task.build(&this->natd->task, message);
+		}
+		if (this->cookie2.ptr)
+		{
+			message->add_notify(message, FALSE, COOKIE2, this->cookie2);
+			chunk_free(&this->cookie2);
+		}
+		if (this->update)
+		{
+			update_children(this);
+		}
+		return SUCCESS;
+	}
+	return NEED_MORE;
+}
+
+METHOD(task_t, process_i, status_t,
+	   private_ike_mobike_t *this, message_t *message)
+{
+	if (message->get_exchange_type(message) == IKE_AUTH &&
+		this->ike_sa->get_state(this->ike_sa) == IKE_ESTABLISHED)
+	{
+		process_payloads(this, message);
+		return SUCCESS;
+	}
+	else if (message->get_exchange_type(message) == INFORMATIONAL)
+	{
+		u_int32_t updates = this->ike_sa->get_pending_updates(this->ike_sa) - 1;
+		this->ike_sa->set_pending_updates(this->ike_sa, updates);
+		if (updates > 0)
+		{
+			/* newer update queued, ignore this one */
+			return SUCCESS;
+		}
+		if (this->cookie2.ptr)
+		{	/* check cookie if we included one */
+			chunk_t cookie2;
+
+			cookie2 = this->cookie2;
+			this->cookie2 = chunk_empty;
+			process_payloads(this, message);
+			if (!chunk_equals(cookie2, this->cookie2))
+			{
+				chunk_free(&cookie2);
+				DBG1(DBG_IKE, "COOKIE2 mismatch, closing IKE_SA");
+				return FAILED;
+			}
+			chunk_free(&cookie2);
+		}
+		else
+		{
+			process_payloads(this, message);
+		}
+		if (this->natd)
+		{
+			this->natd->task.process(&this->natd->task, message);
+			if (this->natd->has_mapping_changed(this->natd))
+			{
+				/* force an update if mappings have changed */
+				this->update = this->check = TRUE;
+				DBG1(DBG_IKE, "detected changes in NAT mappings, "
+					 "initiating MOBIKE update");
+			}
+		}
+		if (this->update)
+		{
+			/* update again, as NAT state may have changed */
+			update_children(this);
+		}
+		if (this->check)
+		{
+			host_t *me_new, *me_old, *other_new, *other_old;
+
+			me_new = message->get_destination(message);
+			other_new = message->get_source(message);
+			me_old = this->ike_sa->get_my_host(this->ike_sa);
+			other_old = this->ike_sa->get_other_host(this->ike_sa);
+
+			if (!me_new->equals(me_new, me_old))
+			{
+				this->update = TRUE;
+				this->ike_sa->set_my_host(this->ike_sa, me_new->clone(me_new));
+			}
+			if (!other_new->equals(other_new, other_old))
+			{
+				this->update = TRUE;
+				this->ike_sa->set_other_host(this->ike_sa, other_new->clone(other_new));
+			}
+			if (this->update)
+			{
+				/* use the same task to ... */
+				if (!this->ike_sa->has_condition(this->ike_sa,
+												 COND_ORIGINAL_INITIATOR))
+				{	/*... send an updated list of addresses as responder */
+					update_children(this);
+					this->update = FALSE;
+				}
+				else
+				{	/* ... send the update as original initiator */
+					if (this->natd)
+					{
+						this->natd->task.destroy(&this->natd->task);
+					}
+					this->natd = ike_natd_create(this->ike_sa, this->initiator);
+				}
+				this->check = FALSE;
+				this->ike_sa->set_pending_updates(this->ike_sa, 1);
+				return NEED_MORE;
+			}
+		}
+		return SUCCESS;
+	}
+	return NEED_MORE;
+}
+
+METHOD(ike_mobike_t, addresses, void,
+	   private_ike_mobike_t *this)
+{
+	this->address = TRUE;
+	this->ike_sa->set_pending_updates(this->ike_sa,
+						this->ike_sa->get_pending_updates(this->ike_sa) + 1);
+}
+
+METHOD(ike_mobike_t, roam, void,
+	   private_ike_mobike_t *this, bool address)
+{
+	this->check = TRUE;
+	this->address = address;
+	this->ike_sa->set_pending_updates(this->ike_sa,
+						this->ike_sa->get_pending_updates(this->ike_sa) + 1);
+}
+
+METHOD(ike_mobike_t, dpd, void,
+	   private_ike_mobike_t *this)
+{
+	if (!this->natd)
+	{
+		this->natd = ike_natd_create(this->ike_sa, this->initiator);
+	}
+	this->ike_sa->set_pending_updates(this->ike_sa,
+						this->ike_sa->get_pending_updates(this->ike_sa) + 1);
+}
+
+METHOD(ike_mobike_t, is_probing, bool,
+	   private_ike_mobike_t *this)
+{
+	return this->check;
+}
+
+METHOD(task_t, get_type, task_type_t,
+	   private_ike_mobike_t *this)
+{
+	return TASK_IKE_MOBIKE;
+}
+
+METHOD(task_t, migrate, void,
+	   private_ike_mobike_t *this, ike_sa_t *ike_sa)
+{
+	chunk_free(&this->cookie2);
+	this->ike_sa = ike_sa;
+	if (this->natd)
+	{
+		this->natd->task.migrate(&this->natd->task, ike_sa);
+	}
+}
+
+METHOD(task_t, destroy, void,
+	   private_ike_mobike_t *this)
+{
+	chunk_free(&this->cookie2);
+	if (this->natd)
+	{
+		this->natd->task.destroy(&this->natd->task);
+	}
+	free(this);
+}
+
+/*
+ * Described in header.
+ */
+ike_mobike_t *ike_mobike_create(ike_sa_t *ike_sa, bool initiator)
+{
+	private_ike_mobike_t *this;
+
+	INIT(this,
+		.public = {
+			.task = {
+				.get_type = _get_type,
+				.migrate = _migrate,
+				.destroy = _destroy,
+			},
+			.addresses = _addresses,
+			.roam = _roam,
+			.dpd = _dpd,
+			.transmit = _transmit,
+			.is_probing = _is_probing,
+		},
+		.ike_sa = ike_sa,
+		.initiator = initiator,
+	);
+
+	if (initiator)
+	{
+		this->public.task.build = _build_i;
+		this->public.task.process = _process_i;
+	}
+	else
+	{
+		this->public.task.build = _build_r;
+		this->public.task.process = _process_r;
+	}
+
+	return &this->public;
+}