src/charon/sa/child_sa.h

@@ -0,0 +1,149 @@
+/**
+ * @file child_sa.h
+ *
+ * @brief Interface of child_sa_t.
+ *
+ */
+
+/*
+ * Copyright (C) 2005 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.
+ */
+
+
+#ifndef CHILD_SA_H_
+#define CHILD_SA_H_
+
+#include <types.h>
+#include <crypto/prf_plus.h>
+#include <encoding/payloads/proposal_substructure.h>
+#include <utils/logger.h>
+
+typedef struct child_sa_t child_sa_t;
+
+/**
+ * @brief Represents multiple IPsec SAs between two hosts.
+ * 
+ * A child_sa_t contains multiple SAs. SAs for both
+ * directions are managed in one child_sa_t object, and
+ * if both AH and ESP is set up, both protocols are managed
+ * by one child_sa_t. This means we can have two or
+ * in the AH+ESP case four IPsec-SAs in one child_sa_t.
+ * 
+ * The procedure for child sa setup is as follows:
+ * - A gets SPIs for a proposal via child_sa_t.alloc
+ * - A send the updated proposal to B
+ * - B selects a suitable proposal
+ * - B calls child_sa_t.add to add and update the selected proposal
+ * - B sends the updated proposal to A
+ * - A calls child_sa_t.update to update the already allocated SPIs with the chosen proposal
+ * 
+ * Once SAs are set up, policies can be added using add_policies.
+ * 
+ * 
+ * @b Constructors:
+ *  - child_sa_create()
+ * 
+ * @ingroup sa
+ */
+struct child_sa_t {
+	
+	/**
+	 * @brief Allocate SPIs for a given proposals.
+	 * 
+	 * Since the kernel manages SPIs for us, we need
+	 * to allocate them. If the proposal contains more
+	 * than one protocol, for each protocol an SPI is
+	 * allocated. SPIs are stored internally and written
+	 * back to the proposal.
+	 *
+	 * @param this 		calling object
+	 * @param proposal	proposal for which SPIs are allocated
+	 */
+	status_t (*alloc)(child_sa_t *this, linked_list_t* proposals);
+	
+	/**
+	 * @brief Install the kernel SAs for a proposal.
+	 * 
+	 * Since the kernel manages SPIs for us, we need
+	 * to allocate them. If the proposal contains more
+	 * than one protocol, for each protocol an SPI is
+	 * allocated. SPIs are stored internally and written
+	 * back to the proposal.
+	 *
+	 * @param this 		calling object
+	 * @param proposal	proposal for which SPIs are allocated
+	 * @param prf_plus	key material to use for key derivation
+	 */
+	status_t (*add)(child_sa_t *this, proposal_t *proposal, prf_plus_t *prf_plus);
+	
+	/**
+	 * @brief Install the kernel SAs for a proposal, if SPIs already allocated.
+	 * 
+	 * This one updates the SAs in the kernel, which are
+	 * allocated via alloc, with a selected proposals.
+	 *
+	 * @param this 		calling object
+	 * @param proposal	proposal for which SPIs are allocated
+	 * @param prf_plus	key material to use for key derivation
+	 */
+	status_t (*update)(child_sa_t *this, proposal_t *proposal, prf_plus_t *prf_plus);
+	
+	/**
+	 * @brief Install the policies using some traffic selectors.
+	 * 
+	 * Spplied lists of traffic_selector_t's specify the policies
+	 * to use for this child sa.
+	 *
+	 * @param this 		calling object
+	 * @param my_ts		traffic selectors for local site
+	 * @param other_ts	traffic selectors for remote site
+	 * @return			SUCCESS or FAILED
+	 */	
+	status_t (*add_policies) (child_sa_t *this, linked_list_t *my_ts_list, linked_list_t *other_ts_list);
+	
+	/**
+	 * @brief Log the status of a child_sa to a logger.
+	 *
+	 * The status of ESP/AH SAs is logged with the supplied logger in
+	 * a human readable form.
+	 * Supplying NULL as logger uses the internal child_sa logger
+	 * to do the logging. The name is only a log-prefix without further
+	 * meaning.
+	 *
+	 * @param this 		calling object
+	 * @param logger	logger to use for logging
+	 * @param name		connection name
+	 */	
+	void (*log_status) (child_sa_t *this, logger_t *logger, char *name);
+	
+	/**
+	 * @brief Destroys a child_sa.
+	 *
+	 * @param this 		calling object
+	 */
+	void (*destroy) (child_sa_t *this);
+};
+
+/**
+ * @brief Constructor to create a new child_sa_t.
+ * 
+ * @param me			own address
+ * @param other			remote address
+ * @return				child_sa_t object
+ * 
+ * @ingroup sa
+ */
+child_sa_t * child_sa_create(host_t *me, host_t *other);
+
+#endif /*CHILD_SA_H_*/