7 files changed, 396 insertions, 279 deletions

diff --git a/src/charon/config/backend_manager.c b/src/charon/config/backend_manager.c
new file mode 100644
index 000000000..186273b6e
--- /dev/null
+++ b/src/charon/config/backend_manager.c
@@ -0,0 +1,244 @@
+/**
+ * @file backend_manager.c
+ * 
+ * @brief Implementation of backend_manager_t.
+ * 
+ */
+
+/*
+ * 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 "backend_manager.h"
+
+#include <sys/types.h>
+#include <dirent.h>
+#include <sys/stat.h>
+#include <dlfcn.h>
+
+#include <daemon.h>
+#include <utils/linked_list.h>
+#include <config/backends/writeable_backend.h>
+
+
+typedef struct private_backend_manager_t private_backend_manager_t;
+
+/**
+ * Private data of an backend_manager_t object.
+ */
+struct private_backend_manager_t {
+
+	/**
+	 * Public part of backend_manager_t object.
+	 */
+	backend_manager_t public;
+	
+	/**
+	 * list of registered backends
+	 */
+	linked_list_t *backends;
+	
+	/**
+	 * Additional list of writable backends.
+	 */
+	linked_list_t *writeable;
+	
+	/**
+	 * List of dlopen() handles we used to open backends
+	 */
+	linked_list_t *handles;
+};
+
+/**
+ * implements backend_manager_t.get_ike_cfg.
+ */
+static ike_cfg_t *get_ike_cfg(private_backend_manager_t *this, 
+							  host_t *my_host, host_t *other_host)
+{
+	backend_t *backend;
+	ike_cfg_t *config = NULL;
+	iterator_t *iterator = this->backends->create_iterator(this->backends, TRUE);
+	while (config == NULL && iterator->iterate(iterator, (void**)&backend))
+	{
+		config = backend->get_ike_cfg(backend, my_host, other_host);
+	}
+	iterator->destroy(iterator);
+	return config;
+}
+
+/**
+ * implements backend_manager_t.get_peer_cfg.
+ */			
+static peer_cfg_t *get_peer_cfg(private_backend_manager_t *this,
+								identification_t *my_id, identification_t *other_id,
+								identification_t *other_ca, char *other_group,
+							    host_t *my_host, host_t *other_host)
+{
+	backend_t *backend;
+	peer_cfg_t *config = NULL;
+	iterator_t *iterator = this->backends->create_iterator(this->backends, TRUE);
+	while (config == NULL && iterator->iterate(iterator, (void**)&backend))
+	{
+		config = backend->get_peer_cfg(backend, my_id, other_id, other_ca,
+									   other_group, my_host, other_host);
+	}
+	iterator->destroy(iterator);
+	return config;
+}
+
+/**
+ * implements backend_manager_t.add_peer_cfg.
+ */	
+static void add_peer_cfg(private_backend_manager_t *this, peer_cfg_t *config)
+{
+	writeable_backend_t *backend;
+	
+	if (this->writeable->get_first(this->writeable, (void**)&backend) == SUCCESS)
+	{
+		backend->add_cfg(backend, config);
+	}
+}
+
+/**
+ * implements backend_manager_t.create_iterator.
+ */	
+static iterator_t* create_iterator(private_backend_manager_t *this)
+{
+	writeable_backend_t *backend;
+	
+	if (this->writeable->get_first(this->writeable, (void**)&backend) == SUCCESS)
+	{
+		return backend->create_iterator(backend);
+	}
+	/* give out an empty iterator if we have no writable backend*/
+	return this->writeable->create_iterator(this->writeable, TRUE);
+}
+
+/**
+ * load the configuration backend modules
+ */
+static void load_backends(private_backend_manager_t *this)
+{
+	struct dirent* entry;
+	struct stat stb;
+	DIR* dir;
+	
+	if (stat(IPSEC_BACKENDDIR, &stb) == -1 || !(stb.st_mode & S_IFDIR))
+	{
+		DBG1(DBG_CFG, "error opening backend modules directory "IPSEC_BACKENDDIR);
+		return;
+	}
+
+	dir = opendir(IPSEC_BACKENDDIR);
+	if (dir == NULL)
+	{
+		DBG1(DBG_CFG, "error opening backend modules directory "IPSEC_BACKENDDIR);
+		return;
+	}
+	
+	DBG1(DBG_CFG, "loading backend modules from '"IPSEC_BACKENDDIR"'");
+
+	while ((entry = readdir(dir)) != NULL)
+	{
+		char file[256];
+		backend_t *backend;
+		backend_constructor_t constructor;
+		void *handle;
+		char *ending;
+		
+		snprintf(file, sizeof(file), IPSEC_BACKENDDIR"/%s", entry->d_name);
+		
+		if (stat(file, &stb) == -1 || !(stb.st_mode & S_IFREG))
+		{
+			DBG2(DBG_CFG, "  skipping %s, doesn't look like a file",
+				 entry->d_name);
+			continue;
+		}
+		ending = entry->d_name + strlen(entry->d_name) - 3;
+		if (ending <= entry->d_name || !streq(ending, ".so"))
+		{
+			/* skip anything which does not look like a library */
+			DBG2(DBG_CFG, "  skipping %s, doesn't look like a library",
+				 entry->d_name);
+			continue;
+		}
+		/* try to load the library */
+		handle = dlopen(file, RTLD_LAZY);
+		if (handle == NULL)
+		{
+			DBG1(DBG_CFG, "  opening backend module %s failed: %s",
+				 entry->d_name, dlerror());
+			continue;
+		}
+		constructor = dlsym(handle, "backend_create");
+		if (constructor == NULL)
+		{
+			DBG1(DBG_CFG, "  backend module %s has no backend_create() "
+				 "function, skipped", entry->d_name);
+			dlclose(handle);
+			continue;
+		}
+		
+		backend = constructor();
+		if (backend == NULL)
+		{
+			DBG1(DBG_CFG, "  unable to create instance of backend "
+				 "module %s, skipped", entry->d_name);
+			dlclose(handle);
+			continue;
+		}
+		DBG1(DBG_CFG, "  loaded backend module successfully from %s", entry->d_name);
+		this->backends->insert_last(this->backends, backend);
+		if (backend->is_writeable(backend))
+		{
+			this->writeable->insert_last(this->writeable, backend);
+		}
+		this->handles->insert_last(this->handles, handle);
+	}
+	closedir(dir);
+}
+
+/**
+ * Implementation of backend_manager_t.destroy.
+ */
+static void destroy(private_backend_manager_t *this)
+{
+	this->backends->destroy_offset(this->backends, offsetof(backend_t, destroy));
+	this->writeable->destroy(this->writeable);
+	this->handles->destroy_function(this->handles, (void*)dlclose);
+	free(this);
+}
+
+/*
+ * Described in header-file
+ */
+backend_manager_t *backend_manager_create()
+{
+	private_backend_manager_t *this = malloc_thing(private_backend_manager_t);
+	
+	this->public.get_ike_cfg = (ike_cfg_t*(*)(backend_manager_t*, host_t *, host_t *))get_ike_cfg;
+	this->public.get_peer_cfg = (peer_cfg_t*(*)(backend_manager_t*, identification_t *, identification_t *))get_peer_cfg;
+	this->public.add_peer_cfg = (void(*)(backend_manager_t*, peer_cfg_t*))add_peer_cfg;
+	this->public.create_iterator = (iterator_t*(*)(backend_manager_t*))create_iterator;
+	this->public.destroy = (void(*)(backend_manager_t*))destroy;
+	
+	this->backends = linked_list_create();
+	this->writeable = linked_list_create();
+	this->handles = linked_list_create();
+	
+	load_backends(this);
+	
+	return &this->public;
+}
+
diff --git a/src/charon/config/cfg_store.h b/src/charon/config/backend_manager.h
index be36cd399..07cd9c541 100644
--- a/src/charon/config/cfg_store.h
+++ b/src/charon/config/backend_manager.h
@@ -1,7 +1,7 @@
 /**
- * @file cfg_store.h
+ * @file backend_manager.h
  * 
- * @brief Interface cfg_store_t.
+ * @brief Interface backend_manager_t.
  *  
  */
 
@@ -20,10 +20,10 @@
  * for more details.
  */
 
-#ifndef CFG_STORE_H_
-#define CFG_STORE_H_
+#ifndef BACKEND_MANAGER_H_
+#define BACKEND_MANAGER_H_
 
-typedef struct cfg_store_t cfg_store_t;
+typedef struct backend_manager_t backend_manager_t;
 
 #include <library.h>
 #include <utils/host.h>
@@ -34,9 +34,9 @@ typedef struct cfg_store_t cfg_store_t;
 
 
 /**
- * @brief A multiplexer to use multiple cfg_store backends.
+ * @brief A multiplexer to use multiple backends.
  *
- * Charon allows the use of multiple cfg_store backends simultaneously. To
+ * Charon allows the use of multiple backend_manager backends simultaneously. To
  * access all this backends by a single call, this class wraps multiple
  * backends behind a single object.
  * Backends may be registered and unregister at runtime dynamically.
@@ -44,22 +44,20 @@ typedef struct cfg_store_t cfg_store_t;
 
    +---------+      +-----------+         +--------------+     |
    |         |      |           |       +--------------+ |     |
-   | daemon  |----->| cfg_store |     +--------------+ |-+  <==|==> IPC
-   |  core   |      |           |---->|   backends   |-+       |
+   | daemon  |----->| backend_- |     +--------------+ |-+  <==|==> IPC
+   |  core   |      | manager   |---->|   backends   |-+       |
    |         |----->|           |     +--------------+         |
    |         |      |           |                              |
    +---------+      +-----------+                              |
    
    @endverbatim
- * Configuration lookup is done only when acting as responder. For initating
- * the corresponding controller is responsible to get a config to initiate.
  *
  * @b Constructors:
- * - cfg_store_create()
+ * - backend_manager_create()
  * 
  * @ingroup config
  */
-struct cfg_store_t {
+struct backend_manager_t {
 	
 	/**
 	 * @brief Get an ike_config identified by two hosts.
@@ -69,7 +67,7 @@ struct cfg_store_t {
 	 * @param other_host		address of remote host
 	 * @return					matching ike_config, or NULL if none found
 	 */
-	ike_cfg_t *(*get_ike_cfg)(cfg_store_t *this, 
+	ike_cfg_t *(*get_ike_cfg)(backend_manager_t *this, 
 							  host_t *my_host, host_t *other_host);
 	
 	/**
@@ -80,40 +78,41 @@ struct cfg_store_t {
 	 * @param other_id			peers ID
 	 * @return					matching peer_config, or NULL if none found
 	 */
-	peer_cfg_t *(*get_peer_cfg)(cfg_store_t *this, identification_t *my_id,
+	peer_cfg_t *(*get_peer_cfg)(backend_manager_t *this, identification_t *my_id,
 								identification_t *other_id);
 	
 	/**
-	 * @brief Register a backend to be queried by the calls above.
+	 * @brief Add a peer_config to the first found writable backend.
 	 *
-	 * The backend first added is the most preferred.
-	 *
-	 * @param this 					calling object
+	 * @param this		calling object
+	 * @param config	peer_config to add to the backend
 	 */
-	void (*register_backend) (cfg_store_t *this, backend_t *backend);
+	void (*add_peer_cfg)(backend_manager_t *this, peer_cfg_t *config);
 	
 	/**
-	 * @brief Unregister a backend.
+	 * @brief Create an iterator over all peer configs of the writable backend.
 	 *
-	 * @param this 					calling object
+	 * @param this		calling object
+	 * @return 			iterator over peer configs
 	 */
-	void (*unregister_backend) (cfg_store_t *this, backend_t *backend);
+	iterator_t* (*create_iterator)(backend_manager_t *this);
 	
 	/**
-	 * @brief Destroys a cfg_store_t object.
+	 * @brief Destroys a backend_manager_t object.
 	 *
 	 * @param this 					calling object
 	 */
-	void (*destroy) (cfg_store_t *this);
+	void (*destroy) (backend_manager_t *this);
 };
 
 /**
- * @brief Create a new instance of the store.
+ * @brief Create a new instance of the manager and loads all backends.
  *
- * @return		cfg_store instance
+ * @return		backend_manager instance
  *
  * @ingroup config
  */
-cfg_store_t *cfg_store_create(void);
+backend_manager_t *backend_manager_create(void);
+
+#endif /*BACKEND_MANAGER_H_*/
 
-#endif /*CFG_STORE_H_*/
diff --git a/src/charon/config/backends/backend.h b/src/charon/config/backends/backend.h
index 52df0a287..5f9543028 100644
--- a/src/charon/config/backends/backend.h
+++ b/src/charon/config/backends/backend.h
@@ -30,7 +30,6 @@ typedef struct backend_t backend_t;
 #include <config/peer_cfg.h>
 #include <utils/linked_list.h>
 
-
 /**
  * @brief The interface for a configuration backend.
  *
@@ -54,28 +53,48 @@ struct backend_t {
 	 * @return					matching ike_config, or NULL if none found
 	 */
 	ike_cfg_t *(*get_ike_cfg)(backend_t *this, 
-								 host_t *my_host, host_t *other_host);
+							  host_t *my_host, host_t *other_host);
 	
 	/**
 	 * @brief Get a peer_cfg identified by two IDs.
+	 * 
+	 * Select a config for two IDs, the others certificate issuer, and
+	 * a AC certificate group. The hosts are just a hint to select the
+	 * correct config if multiple configs match.
 	 *
 	 * @param this				calling object
 	 * @param my_id				own ID
 	 * @param other_id			peers ID
+	 * @param my_host			address of own host
+	 * @param other_host		address of remote host
 	 * @return					matching peer_config, or NULL if none found
 	 */
 	peer_cfg_t *(*get_peer_cfg)(backend_t *this,
-								   identification_t *my_id,
-								   identification_t *other_id);
+								identification_t *my_id, identification_t *other_id,
+								identification_t *other_ca, char *other_group,
+							    host_t *my_host, host_t *other_host);
 	
 	/**
-	 * @brief Get a peer_cfg identified by its name.
+	 * @brief Check if a backend is writable and implements writable_backend_t.
 	 *
-	 * @param this				calling object
-	 * @param name				configs name
-	 * @return					matching peer_config, or NULL if none found
+	 * @param this		calling object
+	 * @return			TRUE if backend implements writable_backend_t.
+	 */
+	bool (*is_writeable)(backend_t *this);
+	
+	/**
+	 * @brief Destroy a backend.
+	 *
+	 * @param this		calling object
 	 */
-	peer_cfg_t *(*get_peer_cfg_by_name)(backend_t *this, char *name);
+	void (*destroy)(backend_t *this);
 };
 
+
+/**
+ * Construction to create a backend.
+ */
+typedef backend_t*(*backend_constructor_t)(void);
+
 #endif /* BACKEND_H_ */
+
diff --git a/src/charon/config/backends/local_backend.c b/src/charon/config/backends/local_backend.c
index be6fc923b..b1e68ee6f 100644
--- a/src/charon/config/backends/local_backend.c
+++ b/src/charon/config/backends/local_backend.c
@@ -52,7 +52,7 @@ struct private_local_backend_t {
 };
 
 /**
- * implements cfg_store_t.get_ike_cfg.
+ * implements backen_t.get_ike_cfg.
  */
 static ike_cfg_t *get_ike_cfg(private_local_backend_t *this, 
 							  host_t *my_host, host_t *other_host)
@@ -116,11 +116,12 @@ static ike_cfg_t *get_ike_cfg(private_local_backend_t *this,
 }
 
 /**
- * implements cfg_store_t.get_peer.
+ * implements backend_t.get_peer.
  */			
-static peer_cfg_t *get_peer_cfg(private_local_backend_t *this, 
-								   identification_t *my_id,
-								   identification_t *other_id)
+static peer_cfg_t *get_peer_cfg(private_local_backend_t *this,
+								identification_t *my_id, identification_t *other_id,
+								identification_t *other_ca, char *other_group,
+							    host_t *my_host, host_t *other_host)
 {
 	peer_cfg_t *current, *found = NULL;
 	iterator_t *iterator;
@@ -166,58 +167,25 @@ static peer_cfg_t *get_peer_cfg(private_local_backend_t *this,
 }
 
 /**
- * implements cfg_store_t.get_peer_by_name.
- */					
-static peer_cfg_t *get_peer_cfg_by_name(private_local_backend_t *this,
-										char *name)
+ * Implementation of backend_t.is_writable.
+ */
+static bool is_writeable(private_local_backend_t *this)
 {
-	iterator_t *i1, *i2;
-	peer_cfg_t *current, *found = NULL;
-	child_cfg_t *child;
-	
-	i1 = this->cfgs->create_iterator(this->cfgs, TRUE);
-	while (i1->iterate(i1, (void**)&current))
-	{
-		/* compare peer_cfgs name first */
-		if (streq(current->get_name(current), name))
-		{
-			found = current;
-			found->get_ref(found);
-			break;
-		}
-		/* compare all child_cfg names otherwise */
-		i2 = current->create_child_cfg_iterator(current);
-		while (i2->iterate(i2, (void**)&child))
-		{
-			if (streq(child->get_name(child), name))
-			{
-				found = current;
-				found->get_ref(found);
-				break;
-			}
-		}
-		i2->destroy(i2);
-		if (found)
-		{
-			break;
-		}
-	}
-	i1->destroy(i1);
-	return found;
+    return TRUE;
 }
 
 /**
- * Implementation of local_backend_t.create_peer_cfg_iterator.
+ * Implementation of writable_backend_t.create_iterator.
  */
-static iterator_t* create_peer_cfg_iterator(private_local_backend_t *this)
+static iterator_t* create_iterator(private_local_backend_t *this)
 {
 	return this->cfgs->create_iterator_locked(this->cfgs, &this->mutex);
 }
 
 /**
- * Implementation of local_backend_t.add_peer_cfg.
+ * Implementation of writable_backend_t.add_peer_cfg.
  */
-static void add_peer_cfg(private_local_backend_t *this, peer_cfg_t *config)
+static void add_cfg(private_local_backend_t *this, peer_cfg_t *config)
 {
     pthread_mutex_lock(&this->mutex);
     this->cfgs->insert_last(this->cfgs, config);
@@ -225,7 +193,7 @@ static void add_peer_cfg(private_local_backend_t *this, peer_cfg_t *config)
 }
 
 /**
- * Implementation of local_backend_t.destroy.
+ * Implementation of backend_t.destroy.
  */
 static void destroy(private_local_backend_t *this)
 {
@@ -236,20 +204,20 @@ static void destroy(private_local_backend_t *this)
 /**
  * Described in header.
  */
-local_backend_t *local_backend_create(void)
+backend_t *backend_create(void)
 {
 	private_local_backend_t *this = malloc_thing(private_local_backend_t);
 	
-	this->public.backend.get_ike_cfg = (ike_cfg_t*(*)(backend_t*, host_t *, host_t *))get_ike_cfg;
-	this->public.backend.get_peer_cfg = (peer_cfg_t*(*)(backend_t*, identification_t *, identification_t *))get_peer_cfg;
-	this->public.create_peer_cfg_iterator = (iterator_t*(*)(local_backend_t*))create_peer_cfg_iterator;
-	this->public.get_peer_cfg_by_name = (peer_cfg_t*(*)(local_backend_t*, char *))get_peer_cfg_by_name;
-    this->public.add_peer_cfg = (void(*)(local_backend_t*, peer_cfg_t *))add_peer_cfg;
-    this->public.destroy = (void(*)(local_backend_t*))destroy;
+	this->public.backend.backend.get_ike_cfg = (ike_cfg_t*(*)(backend_t*, host_t *, host_t *))get_ike_cfg;
+	this->public.backend.backend.get_peer_cfg = (peer_cfg_t*(*)(backend_t*,identification_t*,identification_t*,identification_t*,char*,host_t*,host_t*))get_peer_cfg;
+    this->public.backend.backend.is_writeable = (bool(*)(backend_t*))is_writeable;
+    this->public.backend.backend.destroy = (void(*)(backend_t*))destroy;
+	this->public.backend.create_iterator = (iterator_t*(*)(writeable_backend_t*))create_iterator;
+    this->public.backend.add_cfg = (void(*)(writeable_backend_t*, peer_cfg_t *))add_cfg;
     
 	/* private variables */
 	this->cfgs = linked_list_create();
 	pthread_mutex_init(&this->mutex, NULL);
 	
-	return (&this->public);
+	return (&this->public.backend.backend);
 }
diff --git a/src/charon/config/backends/local_backend.h b/src/charon/config/backends/local_backend.h
index 4caf4a896..f3538eab2 100644
--- a/src/charon/config/backends/local_backend.h
+++ b/src/charon/config/backends/local_backend.h
@@ -26,13 +26,13 @@
 typedef struct local_backend_t local_backend_t;
 
 #include <library.h>
-#include <config/backends/backend.h>
+#include <config/backends/writeable_backend.h>
 
 /**
  * @brief An in-memory backend to store configuration information.
  *
- * The local_backend_t stores the configuration in a simple list. Additional
- * to the backend_t functionality, it adds the modification (add/remove).
+ * The local_backend_t stores the configuration in a simple list. It
+ * implements both, backend_t and writeable_backend_t.
  *
  * @b Constructors:
  *  - local_backend_create()
@@ -42,50 +42,19 @@ typedef struct local_backend_t local_backend_t;
 struct local_backend_t {
 	
 	/**
-	 * Implements backend_t interface
+	 * Implements writable_backend_t interface
 	 */
-	backend_t backend;
-	
-	/**
-	 * @brief Add a peer_config to the backend.
-	 *
-	 * @param this		calling object
-	 * @param config	peer_config to add to the backend
-	 */
-	void (*add_peer_cfg)(local_backend_t *this, peer_cfg_t *config);
-	
-	/**
-	 * @brief Get a peer_config identified by name, or a name of its child_cfgs.
-	 *
-	 * @param this				calling object
-	 * @param name				name of the peer config
-	 * @return					matching peer_config, or NULL if none found
-	 */
-	peer_cfg_t *(*get_peer_cfg_by_name)(local_backend_t *this, char *name);
-	
-	/**
-	 * @brief Create an iterator over all peer configs.
-	 *
-	 * @param this		calling object
-	 * @return 			iterator over peer configs
-	 */
-	iterator_t* (*create_peer_cfg_iterator)(local_backend_t *this);
-	
-	/**
-	 * @brief Destroy a local backend.
-	 *
-	 * @param this		calling object
-	 */
-	void (*destroy)(local_backend_t *this);
+	writeable_backend_t backend;
 };
 
 /**
- * @brief Creates a local_backend_t instance.
+ * @brief Create a backend_t instance implemented as local backend.
  *
- * @return local_backend instance.
+ * @return backend instance.
  * 
  * @ingroup backends
  */
-local_backend_t *local_backend_create(void);
+backend_t *backend_create(void);
 
 #endif /* LOCAL_BACKEND_H_ */
+
diff --git a/src/charon/config/backends/writeable_backend.h b/src/charon/config/backends/writeable_backend.h
new file mode 100644
index 000000000..4771a0cff
--- /dev/null
+++ b/src/charon/config/backends/writeable_backend.h
@@ -0,0 +1,64 @@
+/**
+ * @file writeable_backend.h
+ *
+ * @brief Interface of writeable_backend_t.
+ *
+ */
+
+/*
+ * 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.
+ */
+ 
+#ifndef WRITEABLE_BACKEND_H_
+#define WRITEABLE_BACKEND_H_
+
+typedef struct writeable_backend_t writeable_backend_t;
+
+#include <library.h>
+#include <config/backends/backend.h>
+
+/**
+ * @brief A writeable backend extends the backend by modification functions.
+ *
+ * @b Constructors:
+ *  - writeable_backend_create()
+ * 
+ * @ingroup backends
+ */
+struct writeable_backend_t {
+	
+	/**
+	 * Implements backend_t interface
+	 */
+	backend_t backend;
+	
+	/**
+	 * @brief Add a peer_config to the backend.
+	 *
+	 * @param this		calling object
+	 * @param config	peer_config to add to the backend
+	 */
+	void (*add_cfg)(writeable_backend_t *this, peer_cfg_t *config);
+	
+	/**
+	 * @brief Create an iterator over all peer configs.
+	 *
+	 * @param this		calling object
+	 * @return 			iterator over peer configs
+	 */
+	iterator_t* (*create_iterator)(writeable_backend_t *this);
+};
+
+#endif /* WRITEABLE_BACKEND_H_ */
+
diff --git a/src/charon/config/cfg_store.c b/src/charon/config/cfg_store.c
deleted file mode 100644
index ef945da90..000000000
--- a/src/charon/config/cfg_store.c
+++ /dev/null
@@ -1,146 +0,0 @@
-/**
- * @file cfg_store.c
- * 
- * @brief Implementation of cfg_store_t.
- * 
- */
-
-/*
- * 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 <pthread.h>
-
-#include "cfg_store.h"
-
-#include <library.h>
-#include <utils/linked_list.h>
-
-
-typedef struct private_cfg_store_t private_cfg_store_t;
-
-/**
- * Private data of an cfg_store_t object.
- */
-struct private_cfg_store_t {
-
-	/**
-	 * Public part of cfg_store_t object.
-	 */
-	cfg_store_t public;
-	
-	/**
-	 * list of registered backends
-	 */
-	linked_list_t *backends;
-	
-	/**
-	 * mutex to lock backend list
-	 */
-	pthread_mutex_t mutex;
-};
-
-/**
- * implements cfg_store_t.get_ike.
- */
-static ike_cfg_t *get_ike_cfg(private_cfg_store_t *this, 
-							  host_t *my_host, host_t *other_host)
-{
-	backend_t *backend;
-	ike_cfg_t *config = NULL;
-	iterator_t *iterator = this->backends->create_iterator_locked(
-												this->backends, &this->mutex);
-	while (config == NULL && iterator->iterate(iterator, (void**)&backend))
-	{
-		config = backend->get_ike_cfg(backend, my_host, other_host);
-	}
-	iterator->destroy(iterator);
-	return config;
-}
-
-/**
- * implements cfg_store_t.get_peer.
- */			
-static peer_cfg_t *get_peer_cfg(private_cfg_store_t *this, 
-								identification_t *my_id,
-								identification_t *other_id)
-{
-	backend_t *backend;
-	peer_cfg_t *config = NULL;
-	iterator_t *iterator = this->backends->create_iterator_locked(
-												this->backends, &this->mutex);
-	while (config == NULL && iterator->iterate(iterator, (void**)&backend))
-	{
-		config = backend->get_peer_cfg(backend, my_id, other_id);
-	}
-	iterator->destroy(iterator);
-	return config;
-}
-
-/**
- * implements cfg_store_t.register_backend.
- */			
-static void register_backend(private_cfg_store_t *this, backend_t *backend)
-{
-	pthread_mutex_lock(&this->mutex);
-	this->backends->insert_last(this->backends, backend);
-	pthread_mutex_unlock(&this->mutex);
-}
-
-/**
- * implements cfg_store_t.unregister_backend.
- */			
-static void unregister_backend(private_cfg_store_t *this, backend_t *backend)
-{
-	backend_t *current;
-	iterator_t *iterator = this->backends->create_iterator_locked(
-												this->backends, &this->mutex);
-	while (iterator->iterate(iterator, (void**)&current))
-	{
-		if (backend == current)
-		{
-			iterator->remove(iterator);
-			break;
-		}
-	}
-	iterator->destroy(iterator);
-}
-
-/**
- * Implementation of cfg_store_t.destroy.
- */
-static void destroy(private_cfg_store_t *this)
-{
-	this->backends->destroy(this->backends);
-	free(this);
-}
-
-/*
- * Described in header-file
- */
-cfg_store_t *cfg_store_create()
-{
-	private_cfg_store_t *this = malloc_thing(private_cfg_store_t);
-	
-	this->public.get_ike_cfg = (ike_cfg_t*(*)(cfg_store_t*, host_t *, host_t *))get_ike_cfg;
-	this->public.get_peer_cfg = (peer_cfg_t*(*)(cfg_store_t*, identification_t *, identification_t *))get_peer_cfg;
-	this->public.register_backend = (void(*)(cfg_store_t*, backend_t *))register_backend;
-	this->public.unregister_backend = (void(*)(cfg_store_t*, backend_t *))unregister_backend;
-	this->public.destroy = (void(*)(cfg_store_t*))destroy;
-	
-	this->backends = linked_list_create();
-	pthread_mutex_init(&this->mutex, NULL);
-	
-	return &this->public;
-}