Added manager for DNS resolvers

src/libstrongswan/resolver/resolver_manager.c

@@ -0,0 +1,99 @@
+/*
+ * Copyright (C) 2011-2012 Reto Guadagnini
+ * 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 "resolver_manager.h"
+
+#include <utils/debug.h>
+
+typedef struct private_resolver_manager_t private_resolver_manager_t;
+
+/**
+ * private data of resolver_manager
+ */
+struct private_resolver_manager_t {
+
+	/**
+	 * public functions
+	 */
+	resolver_manager_t public;
+
+	/**
+	 * constructor function to create resolver instances
+	 */
+	resolver_constructor_t constructor;
+};
+
+METHOD(resolver_manager_t, add_resolver, void,
+	private_resolver_manager_t *this, resolver_constructor_t constructor)
+{
+	if (!this->constructor)
+	{
+		this->constructor = constructor;
+	}
+}
+
+METHOD(resolver_manager_t, remove_resolver, void,
+	private_resolver_manager_t *this, resolver_constructor_t constructor)
+{
+	if (this->constructor == constructor)
+	{
+		this->constructor = NULL;
+	}
+}
+
+METHOD(resolver_manager_t, create, resolver_t*,
+	private_resolver_manager_t *this)
+{
+	char *resolv_conf;
+	char *trust_anchor_file;
+
+	resolv_conf = lib->settings->get_str(lib->settings,
+										 "libstrongswan.plugins.resolver."
+										 "resolv_conf",
+										 "/etc/resolv.conf");
+
+	trust_anchor_file = lib->settings->get_str(lib->settings,
+											   "libstrongswan.plugins.resolver."
+											   "trust_anchor",
+											   "/etc/trust.anchors");
+
+	return this->constructor(resolv_conf, trust_anchor_file);
+}
+
+METHOD(resolver_manager_t, destroy, void,
+	private_resolver_manager_t *this)
+{
+	free(this);
+}
+
+/*
+ * See header
+ */
+resolver_manager_t *resolver_manager_create()
+{
+	private_resolver_manager_t *this;
+
+	INIT(this,
+			.public = {
+				.add_resolver = _add_resolver,
+				.remove_resolver = _remove_resolver,
+				.create = _create,
+				.destroy = _destroy,
+			},
+	);
+
+	return &this->public;
+}
+

src/libstrongswan/resolver/resolver_manager.h

@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) 2011-2012 Reto Guadagnini
+ * 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.
+ */
+
+/**
+* @defgroup resolver_manager resolver_manager
+* @{ @ingroup resolver
+*/
+
+#ifndef RESOLVER_MANAGER_H_
+#define RESOLVER_MANAGER_H_
+
+typedef struct resolver_manager_t resolver_manager_t;
+
+#include <resolver/resolver.h>
+
+/**
+ * The resolver_manager manages the resolver implementations and
+ * creates instances of them.
+ *
+ * A resolver plugin is registered by providing its constructor function
+ * to the manager. The manager creates instances of the resolver plugin
+ * using the registered constructor function.
+ */
+struct resolver_manager_t {
+
+	/**
+	 * Register a resolver implementation.
+	 *
+	 * @param constructor	resolver constructor function
+	 */
+	void (*add_resolver)(resolver_manager_t *this,
+						 resolver_constructor_t constructor);
+
+	/**
+	 * Unregister a previously registered resolver implementation.
+	 *
+	 * @param constructor	resolver constructor function to unregister
+	 */
+	void (*remove_resolver)(resolver_manager_t *this,
+							resolver_constructor_t constructor);
+
+	/**
+	 * Get a new resolver instance.
+	 *
+	 * @return 				resolver instance.
+	 */
+	resolver_t* (*create)(resolver_manager_t *this);
+
+	/**
+	 * Destroy a resolver_manager instance.
+	 */
+	void (*destroy)(resolver_manager_t *this);
+};
+
+/**
+ * Create a resolver_manager instance.
+ */
+resolver_manager_t *resolver_manager_create();
+
+#endif /** RESOLVER_MANAGER_H_ @}*/