Added a listener to the farp plugin that keeps track of active virtual IPs

src/libcharon/plugins/farp/Makefile.am

@@ -9,6 +9,7 @@ else
 plugin_LTLIBRARIES = libstrongswan-farp.la
 endif
 
-libstrongswan_farp_la_SOURCES = farp_plugin.h farp_plugin.c
+libstrongswan_farp_la_SOURCES = farp_plugin.h farp_plugin.c \
+	farp_listener.h farp_listener.c
 
 libstrongswan_farp_la_LDFLAGS = -module -avoid-version

src/libcharon/plugins/farp/farp_listener.c

@@ -0,0 +1,118 @@
+/*
+ * Copyright (C) 2010 Martin Willi
+ * Copyright (C) 2010 revosec AG
+ *
+ * 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 "farp_listener.h"
+
+#include <utils/hashtable.h>
+
+typedef struct private_farp_listener_t private_farp_listener_t;
+
+/**
+ * Private data of an farp_listener_t object.
+ */
+struct private_farp_listener_t {
+
+	/**
+	 * Public farp_listener_t interface.
+	 */
+	farp_listener_t public;
+
+	/**
+	 * Hashtable with active virtual IPs
+	 */
+	hashtable_t *ips;
+};
+
+/**
+ * Hashtable hash function
+ */
+static u_int hash(host_t *key)
+{
+	return chunk_hash(key->get_address(key));
+}
+
+/**
+ * Hashtable equals function
+ */
+static bool equals(host_t *a, host_t *b)
+{
+	return a->ip_equals(a, b);
+}
+
+METHOD(listener_t, ike_updown, bool,
+	private_farp_listener_t *this, ike_sa_t *ike_sa, bool up)
+{
+	host_t *ip;
+
+	ip = ike_sa->get_virtual_ip(ike_sa, FALSE);
+	if (ip)
+	{
+		if (up)
+		{
+			ip = ip->clone(ip);
+			ip = this->ips->put(this->ips, ip, ip);
+		}
+		else
+		{
+			ip = this->ips->remove(this->ips, ip);
+		}
+		DESTROY_IF(ip);
+	}
+	return TRUE;
+}
+
+METHOD(farp_listener_t, is_active, bool,
+	private_farp_listener_t *this, host_t *ip)
+{
+	return this->ips->get(this->ips, ip) != NULL;
+}
+
+METHOD(farp_listener_t, destroy, void,
+	private_farp_listener_t *this)
+{
+	enumerator_t *enumerator;
+	host_t *key, *value;
+
+	enumerator = this->ips->create_enumerator(this->ips);
+	while (enumerator->enumerate(enumerator, &key, &value))
+	{
+		value->destroy(value);
+	}
+	enumerator->destroy(enumerator);
+	this->ips->destroy(this->ips);
+
+	free(this);
+}
+
+/**
+ * See header
+ */
+farp_listener_t *farp_listener_create()
+{
+	private_farp_listener_t *this;
+
+	INIT(this,
+		.public = {
+			.listener.ike_updown = _ike_updown,
+			.is_active = _is_active,
+			.destroy = _destroy,
+		},
+		.ips = hashtable_create((hashtable_hash_t)hash,
+								(hashtable_equals_t)equals, 8),
+	);
+
+	return &this->public;
+}
+

src/libcharon/plugins/farp/farp_listener.h

@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) 2010 Martin Willi
+ * Copyright (C) 2010 revosec AG
+ *
+ * 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 farp_listener farp_listener
+ * @{ @ingroup farp
+ */
+
+#ifndef FARP_LISTENER_H_
+#define FARP_LISTENER_H_
+
+#include <utils/host.h>
+#include <bus/listeners/listener.h>
+
+typedef struct farp_listener_t farp_listener_t;
+
+/**
+ * Listener to register the set of IPs we spoof ARP responses for.
+ */
+struct farp_listener_t {
+
+	/**
+	 * Implements listener_t interface.
+	 */
+	listener_t listener;
+
+	/**
+	 * Check if a given IP is currently used as virtual IP by a peer.
+	 *
+	 * @param ip		IP to check
+	 * @return			TRUE if IP is an active virtual IP
+	 */
+	bool (*is_active)(farp_listener_t *this, host_t *ip);
+
+	/**
+	 * Destroy a farp_listener_t.
+	 */
+	void (*destroy)(farp_listener_t *this);
+};
+
+/**
+ * Create a farp_listener instance.
+ */
+farp_listener_t *farp_listener_create();
+
+#endif /** FARP_LISTENER_H_ @}*/

src/libcharon/plugins/farp/farp_plugin.c

@@ -15,6 +15,8 @@
 
 #include "farp_plugin.h"
 
+#include "farp_listener.h"
+
 #include <daemon.h>
 
 typedef struct private_farp_plugin_t private_farp_plugin_t;
@@ -28,11 +30,18 @@ struct private_farp_plugin_t {
 	 * implements plugin interface
 	 */
 	farp_plugin_t public;
+
+	/**
+	 * Listener registering active virtual IPs
+	 */
+	farp_listener_t *listener;
 };
 
 METHOD(plugin_t, destroy, void,
 	private_farp_plugin_t *this)
 {
+	charon->bus->remove_listener(charon->bus, &this->listener->listener);
+	this->listener->destroy(this->listener);
 	free(this);
 }
 
@@ -45,8 +54,11 @@ plugin_t *farp_plugin_create()
 
 	INIT(this,
 		.public.plugin.destroy = _destroy,
+		.listener = farp_listener_create(),
 	);
 
+	charon->bus->add_listener(charon->bus, &this->listener->listener);
+
 	return &this->public.plugin;
 }