Add a lookip function to register virtual IP notification listeners

src/libcharon/plugins/lookip/lookip_listener.c

@@ -17,6 +17,7 @@
 
 #include <daemon.h>
 #include <utils/hashtable.h>
+#include <utils/linked_list.h>
 #include <threading/rwlock.h>
 
 typedef struct private_lookip_listener_t private_lookip_listener_t;
@@ -40,8 +41,23 @@ struct private_lookip_listener_t {
 	 * Hashtable with entries: host_t => entry_t
 	 */
 	hashtable_t *entries;
+
+	/**
+	 * List of registered listeners
+	 */
+	linked_list_t *listeners;
 };
 
+/**
+ * Listener entry
+ */
+typedef struct {
+	/** callback function */
+	lookip_callback_t cb;
+	/** user data for callback */
+	void *user;
+} listener_entry_t;
+
 /**
  * Hashtable entry
  */
@@ -84,6 +100,34 @@ static bool equals(host_t *a, host_t *b)
 	return a->ip_equals(a, b);
 }
 
+/**
+ * Compare callback that invokes up callback of all registered listeners
+ */
+static bool notify_up(listener_entry_t *listener, entry_t *entry)
+{
+	if (!listener->cb(listener->user, TRUE, entry->vip, entry->other,
+					  entry->id, entry->name))
+	{
+		free(listener);
+		return TRUE;
+	}
+	return FALSE;
+}
+
+/**
+ * Compare callback that invokes down callback of all registered listeners
+ */
+static bool notify_down(listener_entry_t *listener, entry_t *entry)
+{
+	if (!listener->cb(listener->user, FALSE, entry->vip, entry->other,
+						 entry->id, entry->name))
+	{
+		free(listener);
+		return TRUE;
+	}
+	return FALSE;
+}
+
 /**
  * Add a new entry to the hashtable
  */
@@ -107,6 +151,10 @@ static void add_entry(private_lookip_listener_t *this, ike_sa_t *ike_sa)
 			.name = strdup(ike_sa->get_name(ike_sa)),
 		);
 
+		this->lock->read_lock(this->lock);
+		this->listeners->remove(this->listeners, entry, (void*)notify_up);
+		this->lock->unlock(this->lock);
+
 		this->lock->write_lock(this->lock);
 		entry = this->entries->put(this->entries, entry->vip, entry);
 		this->lock->unlock(this->lock);
@@ -135,6 +183,10 @@ static void remove_entry(private_lookip_listener_t *this, ike_sa_t *ike_sa)
 		this->lock->unlock(this->lock);
 		if (entry)
 		{
+			this->lock->read_lock(this->lock);
+			this->listeners->remove(this->listeners, entry, (void*)notify_down);
+			this->lock->unlock(this->lock);
+
 			entry_destroy(entry);
 		}
 	}
@@ -184,7 +236,7 @@ METHOD(lookip_listener_t, lookup, void,
 		entry = this->entries->get(this->entries, vip);
 		if (entry)
 		{
-			cb(user, entry->vip, entry->other, entry->id, entry->name);
+			cb(user, TRUE, entry->vip, entry->other, entry->id, entry->name);
 		}
 	}
 	else
@@ -194,16 +246,32 @@ METHOD(lookip_listener_t, lookup, void,
 		enumerator = this->entries->create_enumerator(this->entries);
 		while (enumerator->enumerate(enumerator, &vip, &entry))
 		{
-			cb(user, entry->vip, entry->other, entry->id, entry->name);
+			cb(user, TRUE, entry->vip, entry->other, entry->id, entry->name);
 		}
 		enumerator->destroy(enumerator);
 	}
 	this->lock->unlock(this->lock);
 }
 
+METHOD(lookip_listener_t, add_listener, void,
+	private_lookip_listener_t *this, lookip_callback_t cb, void *user)
+{
+	listener_entry_t *listener;
+
+	INIT(listener,
+		.cb = cb,
+		.user = user,
+	);
+
+	this->lock->write_lock(this->lock);
+	this->listeners->insert_last(this->listeners, listener);
+	this->lock->unlock(this->lock);
+}
+
 METHOD(lookip_listener_t, destroy, void,
 	private_lookip_listener_t *this)
 {
+	this->listeners->destroy_function(this->listeners, free);
 	this->entries->destroy(this->entries);
 	this->lock->destroy(this->lock);
 	free(this);
@@ -223,11 +291,13 @@ lookip_listener_t *lookip_listener_create()
 				.ike_updown = _ike_updown,
 			},
 			.lookup = _lookup,
+			.add_listener = _add_listener,
 			.destroy = _destroy,
 		},
 		.lock = rwlock_create(RWLOCK_TYPE_DEFAULT),
 		.entries = hashtable_create((hashtable_hash_t)hash,
 									(hashtable_equals_t)equals, 32),
+		.listeners = linked_list_create(),
 	);
 
 	return &this->public;

src/libcharon/plugins/lookip/lookip_listener.h

@@ -29,14 +29,15 @@ typedef struct lookip_listener_t lookip_listener_t;
  * Callback function to query virtual IP entries
  *
  * @param user		user supplied pointer
+ * @param up		TRUE if tunnels established, FALSE if closed
  * @param vip		virtual IP of remote peer
  * @param other		peer external IP
  * @param id		peer identity
  * @param name		associated connection name
  * @return			TRUE to receive more results, FALSE to cancel
  */
-typedef bool (*lookip_callback_t)(void *user, host_t *vip, host_t *other,
-								  identification_t *id, char *name);
+typedef bool (*lookip_callback_t)(void *user, bool up, host_t *vip,
+							host_t *other, identification_t *id, char *name);
 
 /**
  * Listener collecting virtual IPs.
@@ -51,6 +52,9 @@ struct lookip_listener_t {
 	/**
 	 * Perform a lookup for a given virtual IP, invoke callback for matches.
 	 *
+	 * The "up" parameter is always TRUE when the callback is invoked using
+	 * lookup().
+	 *
 	 * @param vip		virtual IP to look up, NULL to get all entries
 	 * @param cb		callback function to invoke
 	 * @param user		user data to pass to callback function
@@ -58,6 +62,15 @@ struct lookip_listener_t {
 	void (*lookup)(lookip_listener_t *this, host_t *vip,
 				   lookip_callback_t cb, void *user);
 
+	/**
+	 * Register a listener function that gets notified about virtual IP changes.
+	 *
+	 * @param cb		callback function to invoke
+	 * @param user		user data to pass to callback function
+	 */
+	void (*add_listener)(lookip_listener_t *this,
+						 lookip_callback_t cb, void *user);
+
 	/**
 	 * Destroy a lookip_listener_t.
 	 */