ikev2: Add task to handle IKEV2_MESSAGE_ID_SYNC notifies as responder

src/libcharon/Android.mk

@@ -106,6 +106,7 @@ sa/ikev2/tasks/ike_delete.c sa/ikev2/tasks/ike_delete.h \
 sa/ikev2/tasks/ike_dpd.c sa/ikev2/tasks/ike_dpd.h \
 sa/ikev2/tasks/ike_init.c sa/ikev2/tasks/ike_init.h \
 sa/ikev2/tasks/ike_natd.c sa/ikev2/tasks/ike_natd.h \
+sa/ikev2/tasks/ike_mid_sync.c sa/ikev2/tasks/ike_mid_sync.h \
 sa/ikev2/tasks/ike_mobike.c sa/ikev2/tasks/ike_mobike.h \
 sa/ikev2/tasks/ike_rekey.c sa/ikev2/tasks/ike_rekey.h \
 sa/ikev2/tasks/ike_reauth.c sa/ikev2/tasks/ike_reauth.h \

src/libcharon/Makefile.am

@@ -105,6 +105,7 @@ sa/ikev2/tasks/ike_delete.c sa/ikev2/tasks/ike_delete.h \
 sa/ikev2/tasks/ike_dpd.c sa/ikev2/tasks/ike_dpd.h \
 sa/ikev2/tasks/ike_init.c sa/ikev2/tasks/ike_init.h \
 sa/ikev2/tasks/ike_natd.c sa/ikev2/tasks/ike_natd.h \
+sa/ikev2/tasks/ike_mid_sync.c sa/ikev2/tasks/ike_mid_sync.h \
 sa/ikev2/tasks/ike_mobike.c sa/ikev2/tasks/ike_mobike.h \
 sa/ikev2/tasks/ike_rekey.c sa/ikev2/tasks/ike_rekey.h \
 sa/ikev2/tasks/ike_reauth.c sa/ikev2/tasks/ike_reauth.h \

src/libcharon/sa/ikev2/task_manager_v2.c

@@ -34,6 +34,7 @@
 #include <sa/ikev2/tasks/ike_delete.h>
 #include <sa/ikev2/tasks/ike_config.h>
 #include <sa/ikev2/tasks/ike_dpd.h>
+#include <sa/ikev2/tasks/ike_mid_sync.h>
 #include <sa/ikev2/tasks/ike_vendor.h>
 #include <sa/ikev2/tasks/ike_verify_peer_cert.h>
 #include <sa/ikev2/tasks/child_create.h>
@@ -1069,6 +1070,10 @@ static status_t process_request(private_task_manager_t *this,
 									task = (task_t*)ike_redirect_create(
 															this->ike_sa, NULL);
 									break;
+								case IKEV2_MESSAGE_ID_SYNC:
+									task = (task_t*)ike_mid_sync_create(
+																 this->ike_sa);
+									break;
 								default:
 									break;
 							}

src/libcharon/sa/ikev2/tasks/ike_mid_sync.c

@@ -0,0 +1,259 @@
+/*
+ * Copyright (C) 2016 Tobias Brunner
+ * HSR 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.
+ */
+/*
+ * Copyright (C) 2016 Stephen J. Bevan
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "ike_mid_sync.h"
+
+#include <daemon.h>
+#include <bio/bio_reader.h>
+#include <bio/bio_writer.h>
+#include <encoding/payloads/notify_payload.h>
+
+typedef struct private_ike_mid_sync_t private_ike_mid_sync_t;
+
+/**
+ * Private members
+ */
+struct private_ike_mid_sync_t {
+
+	/**
+	 * Public methods and task_t interface.
+	 */
+	ike_mid_sync_t public;
+
+	/**
+	 * Assigned IKE_SA.
+	 */
+	ike_sa_t *ike_sa;
+
+	/**
+	 * Nonce sent by the peer and expected to be returned
+	 */
+	chunk_t nonce;
+
+	/**
+	 * Expected next sender message ID
+	 */
+	uint32_t send;
+
+	/**
+	 * Expected received message ID
+	 */
+	uint32_t recv;
+};
+
+/*
+ * Encoding of IKEV2_MESSAGE_SYNC_ID notify, RFC 6311
+ *
+ *  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
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Next Payload  |C|  RESERVED   |         Payload Length        |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * |Protocol ID(=0)| SPI Size (=0) |      Notify Message Type      |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * |             Nonce Data                                        |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * |             EXPECTED_SEND_REQ_MESSAGE_ID                      |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * |             EXPECTED_RECV_REQ_MESSAGE_ID                      |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ */
+
+/*
+ * RFC 6311 section 5.1
+ *
+ *  o  The peer MUST silently drop any received synchronization message
+ *     if M1 is lower than or equal to the highest value it has seen from
+ *     the cluster.  This includes any previous received synchronization
+ *     messages.
+ */
+METHOD(task_t, pre_process, status_t,
+	private_ike_mid_sync_t *this, message_t *message)
+{
+	notify_payload_t *notify;
+	bio_reader_t *reader;
+	chunk_t nonce;
+	uint32_t resp;
+
+	if (message->get_message_id(message) != 0)
+	{	/* ignore the notify if it was contained in an INFORMATIONAL with
+		 * unexpected message ID */
+		return SUCCESS;
+	}
+	notify = message->get_notify(message, IKEV2_MESSAGE_ID_SYNC);
+
+	reader = bio_reader_create(notify->get_notification_data(notify));
+	if (!reader->read_data(reader, 4, &nonce) ||
+		!reader->read_uint32(reader, &this->send) ||
+		!reader->read_uint32(reader, &this->recv))
+	{
+		reader->destroy(reader);
+		DBG1(DBG_ENC, "received invalid %N notify",
+			 notify_type_names, IKEV2_MESSAGE_ID_SYNC);
+		return FAILED;
+	}
+	reader->destroy(reader);
+	resp = this->ike_sa->get_message_id(this->ike_sa, FALSE);
+	if (this->send < resp)
+	{
+		DBG1(DBG_ENC, "ignore %N notify with lower (%d) than expected (%d) "
+			 "sender MID", notify_type_names, IKEV2_MESSAGE_ID_SYNC, this->send,
+			 resp);
+		return FAILED;
+	}
+	this->nonce = chunk_clone(nonce);
+	return SUCCESS;
+}
+
+/**
+ * Check if there are any active tasks, indicating that we already
+ * used the currents message ID and are waiting for a response.
+ */
+static bool has_active_tasks(private_ike_mid_sync_t *this)
+{
+	enumerator_t *enumerator;
+	task_t *task;
+	bool active;
+
+	enumerator = this->ike_sa->create_task_enumerator(this->ike_sa,
+													  TASK_QUEUE_ACTIVE);
+	active = enumerator->enumerate(enumerator, &task);
+	enumerator->destroy(enumerator);
+	return active;
+}
+
+/*
+ * RFC 6311 section 5.1
+ *
+ *  o  M2 MUST be at least the higher of the received M1, and one more
+ *     than the highest sender value received from the cluster.  This
+ *     includes any previous received synchronization messages.
+ *
+ *  o  P2 MUST be the higher of the received P1 value, and one more than
+ *     the highest sender value used by the peer.
+ *
+ * M1 is this->send, P1 is this->recv
+ */
+METHOD(task_t, process, status_t,
+	private_ike_mid_sync_t *this, message_t *message)
+{
+	uint32_t resp, init, m2, p2;
+
+	if (message->get_message_id(message) != 0)
+	{	/* ignore the notify if it was contained in an INFORMATIONAL with
+		 * unexpected message id */
+		return SUCCESS;
+	}
+	resp = this->ike_sa->get_message_id(this->ike_sa, FALSE);
+	m2 = max(this->send, resp);
+	if (resp != m2)
+	{
+		/* after responding to this message the expected message ID is increased
+		 * by one so we reduce it here */
+		this->ike_sa->set_message_id(this->ike_sa, FALSE, m2 - 1);
+	}
+	init = this->ike_sa->get_message_id(this->ike_sa, TRUE);
+	p2 = max(this->recv, has_active_tasks(this) ? init + 1 : init);
+	if (init != p2)
+	{
+		this->ike_sa->set_message_id(this->ike_sa, TRUE, p2);
+	}
+	DBG1(DBG_IKE, "responder requested MID sync: initiating %d[%d], "
+		 "responding %d[%d]", p2, init, m2, resp);
+	this->send = p2;
+	this->recv = m2;
+	return NEED_MORE;
+}
+
+METHOD(task_t, build, status_t,
+	private_ike_mid_sync_t *this, message_t *message)
+{
+	bio_writer_t *writer;
+
+	writer = bio_writer_create(12);
+	writer->write_data(writer, this->nonce);
+	writer->write_uint32(writer, this->send);
+	writer->write_uint32(writer, this->recv);
+
+	message->set_message_id(message, 0);
+	message->add_notify(message, FALSE, IKEV2_MESSAGE_ID_SYNC,
+						writer->get_buf(writer));
+
+	writer->destroy(writer);
+	return SUCCESS;
+}
+
+METHOD(task_t, get_type, task_type_t,
+	private_ike_mid_sync_t *this)
+{
+	return TASK_IKE_MID_SYNC;
+}
+
+METHOD(task_t, migrate, void,
+	private_ike_mid_sync_t *this, ike_sa_t *ike_sa)
+{
+	this->ike_sa = ike_sa;
+	chunk_free(&this->nonce);
+}
+
+METHOD(task_t, destroy, void,
+	private_ike_mid_sync_t *this)
+{
+	chunk_free(&this->nonce);
+	free(this);
+}
+
+/*
+ * Described in header.
+ */
+ike_mid_sync_t *ike_mid_sync_create(ike_sa_t *ike_sa)
+{
+	private_ike_mid_sync_t *this;
+
+	INIT(this,
+		.public = {
+			.task = {
+				.get_type = _get_type,
+				.build = _build,
+				.pre_process = _pre_process,
+				.process = _process,
+				.migrate = _migrate,
+				.destroy = _destroy,
+			},
+		},
+		.ike_sa = ike_sa,
+	);
+	return &this->public;
+}

src/libcharon/sa/ikev2/tasks/ike_mid_sync.h

@@ -0,0 +1,74 @@
+/*
+ * Copyright (C) 2016 Tobias Brunner
+ * HSR 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.
+ */
+/*
+ * Copyright (C) 2016 Stephen J. Bevan
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+/**
+ * @defgroup ike_mid_sync ike_mid_sync
+ * @{ @ingroup tasks_v2
+ */
+
+#ifndef IKE_MID_SYNC_H_
+#define IKE_MID_SYNC_H_
+
+typedef struct ike_mid_sync_t ike_mid_sync_t;
+
+#include <library.h>
+#include <sa/ike_sa.h>
+#include <sa/task.h>
+
+/**
+ * Task of type TASK_IKE_MID_SYNC, implements RFC 6311 responder.
+ *
+ * This task handles an IKEV2_MESSAGE_ID_SYNC notify sent by a peer
+ * and if acceptable updates the SA MIDs and replies with the updated
+ * MID values.
+ */
+struct ike_mid_sync_t {
+
+	/**
+	 * Implements the task_t interface
+	 */
+	task_t task;
+};
+
+/**
+ * Create a new TASK_IKE_MID_SYNC task.
+ *
+ * @param ike_sa	IKE_SA this task works for
+ * @return			task to handle by the task_manager
+ */
+ike_mid_sync_t *ike_mid_sync_create(ike_sa_t *ike_sa);
+
+#endif /** IKE_MID_SYNC_H_ @}*/

src/libcharon/sa/task.c

@@ -30,6 +30,7 @@ ENUM(task_type_names, TASK_IKE_INIT, TASK_ISAKMP_CERT_POST,
 	"IKE_REAUTH_COMPLETE",
 	"IKE_REDIRECT",
 	"IKE_VERIFY_PEER_CERT",
+	"IKE_MID_SYNC",
 	"IKE_DELETE",
 	"IKE_DPD",
 	"IKE_VENDOR",

src/libcharon/sa/task.h

@@ -61,6 +61,8 @@ enum task_type_t {
 	TASK_IKE_REDIRECT,
 	/** verify a peer's certificate */
 	TASK_IKE_VERIFY_PEER_CERT,
+	/** synchronize message IDs, RFC6311 */
+	TASK_IKE_MID_SYNC,
 	/** delete an IKE_SA */
 	TASK_IKE_DELETE,
 	/** liveness check */