Handle multiple lookip connections using a single FDSET

src/libcharon/plugins/lookip/lookip_socket.c

@@ -57,6 +57,11 @@ struct private_lookip_socket_t {
 	 */
 	linked_list_t *registered;
 
+	/**
+	 * List of connected clients, as uintptr_t FD
+	 */
+	linked_list_t *connected;
+
 	/**
 	 * Mutex to lock clients list
 	 */
@@ -222,73 +227,179 @@ static void subscribe(private_lookip_socket_t *this, int fd, int type)
 	this->listener->add_listener(this->listener, (void*)listener_cb, entry);
 }
 
+/**
+ * Check if a client is subscribed for notifications
+ */
+static bool subscribed(private_lookip_socket_t *this, int fd)
+{
+	enumerator_t *enumerator;
+	bool subscribed = FALSE;
+	entry_t *entry;
+
+	this->mutex->lock(this->mutex);
+	enumerator = this->registered->create_enumerator(this->registered);
+	while (enumerator->enumerate(enumerator, &entry))
+	{
+		if (entry->fd == fd)
+		{
+			subscribed = TRUE;
+			break;
+		}
+	}
+	enumerator->destroy(enumerator);
+	this->mutex->unlock(this->mutex);
+
+	return subscribed;
+}
+
+/**
+ * Create a fd_set from all bound sockets
+ */
+static int build_fds(private_lookip_socket_t *this, fd_set *fds)
+{
+	enumerator_t *enumerator;
+	uintptr_t fd;
+	int maxfd;
+
+	FD_ZERO(fds);
+	FD_SET(this->socket, fds);
+	maxfd = this->socket;
+
+	this->mutex->lock(this->mutex);
+	enumerator = this->connected->create_enumerator(this->connected);
+	while (enumerator->enumerate(enumerator, &fd))
+	{
+		FD_SET(fd, fds);
+		maxfd = max(maxfd, fd);
+	}
+	enumerator->destroy(enumerator);
+	this->mutex->unlock(this->mutex);
+
+	return maxfd + 1;
+}
+
+/**
+ * Find the socket select()ed
+ */
+static int scan_fds(private_lookip_socket_t *this, fd_set *fds)
+{
+	enumerator_t *enumerator;
+	uintptr_t fd;
+	int selected = -1;
+
+	this->mutex->lock(this->mutex);
+	enumerator = this->connected->create_enumerator(this->connected);
+	while (enumerator->enumerate(enumerator, &fd))
+	{
+		if (FD_ISSET(fd, fds))
+		{
+			selected = fd;
+			break;
+		}
+	}
+	enumerator->destroy(enumerator);
+	this->mutex->unlock(this->mutex);
+
+	return selected;
+}
+
+/**
+ * Dispatch from a socket, return TRUE to end communication
+ */
+static bool dispatch(private_lookip_socket_t *this, int fd)
+{
+	lookip_request_t req;
+	int len;
+
+	len = recv(fd, &req, sizeof(req), 0);
+	if (len != sizeof(req))
+	{
+		if (len != 0)
+		{
+			DBG1(DBG_CFG, "receiving lookip request failed: %s",
+				 strerror(errno));
+		}
+		return TRUE;
+	}
+	switch (req.type)
+	{
+		case LOOKIP_LOOKUP:
+			query(this, fd, &req);
+			return FALSE;
+		case LOOKIP_DUMP:
+			query(this, fd, NULL);
+			return FALSE;
+		case LOOKIP_REGISTER_UP:
+			subscribe(this, fd, LOOKIP_NOTIFY_UP);
+			return FALSE;
+		case LOOKIP_REGISTER_DOWN:
+			subscribe(this, fd, LOOKIP_NOTIFY_DOWN);
+			return FALSE;
+		case LOOKIP_END:
+			return TRUE;
+		default:
+			DBG1(DBG_CFG, "received unknown lookip command");
+			return TRUE;
+	}
+}
+
 /**
  * Accept client connections, dispatch
  */
 static job_requeue_t receive(private_lookip_socket_t *this)
 {
 	struct sockaddr_un addr;
-	int fd, len = sizeof(addr);
-	lookip_request_t req;
-	bool oldstate, subscribed = FALSE;
+	int fd, maxfd, len;
+	bool oldstate;
+	fd_set fds;
 
-	oldstate = thread_cancelability(TRUE);
-	fd = accept(this->socket, (struct sockaddr*)&addr, &len);
-	thread_cancelability(oldstate);
-
-	if (fd != -1)
+	while (TRUE)
 	{
-		while (TRUE)
+		maxfd = build_fds(this, &fds);
+		oldstate = thread_cancelability(TRUE);
+		if (select(maxfd, &fds, NULL, NULL, NULL) <= 0)
 		{
-			oldstate = thread_cancelability(TRUE);
-			len = recv(fd, &req, sizeof(req), 0);
 			thread_cancelability(oldstate);
+			DBG1(DBG_CFG, "selecting lookip sockets failed: %s",
+				 strerror(errno));
+			break;
+		}
+		thread_cancelability(oldstate);
 
-			if (len == sizeof(req))
+		if (FD_ISSET(this->socket, &fds))
+		{	/* new connection, accept() */
+			len = sizeof(addr);
+			fd = accept(this->socket, (struct sockaddr*)&addr, &len);
+			if (fd != -1)
 			{
-				switch (req.type)
-				{
-					case LOOKIP_LOOKUP:
-						query(this, fd, &req);
-						continue;
-					case LOOKIP_DUMP:
-						query(this, fd, NULL);
-						continue;
-					case LOOKIP_REGISTER_UP:
-						subscribe(this, fd, LOOKIP_NOTIFY_UP);
-						subscribed = TRUE;
-						continue;
-					case LOOKIP_REGISTER_DOWN:
-						subscribe(this, fd, LOOKIP_NOTIFY_DOWN);
-						subscribed = TRUE;
-						continue;
-					case LOOKIP_END:
-						break;
-					default:
-						DBG1(DBG_CFG, "received unknown lookip command");
-						break;
-				}
+				this->mutex->lock(this->mutex);
+				this->connected->insert_last(this->connected,
+											 (void*)(uintptr_t)fd);
+				this->mutex->unlock(this->mutex);
 			}
 			else
 			{
-				if (len != 0)
-				{
-					DBG1(DBG_CFG, "receiving lookip request failed: %s",
-						 strerror(errno));
-				}
-				break;
+				DBG1(DBG_CFG, "accepting lookip connection failed: %s",
+					 strerror(errno));
 			}
-			break;
+			continue;
 		}
-		if (!subscribed)
-		{	/* don't close if we queued the fd */
-			close(fd);
+
+		fd = scan_fds(this, &fds);
+		if (fd == -1)
+		{
+			continue;
+		}
+		if (dispatch(this, fd))
+		{
+			this->mutex->lock(this->mutex);
+			this->connected->remove(this->connected, (void*)(uintptr_t)fd, NULL);
+			this->mutex->unlock(this->mutex);
+			if (!subscribed(this, fd))
+			{
+				close(fd);
+			}
 		}
-	}
-	else
-	{
-		DBG1(DBG_CFG, "accepting lookip connection failed: %s",
-			 strerror(errno));
 	}
 	return JOB_REQUEUE_FAIR;
 }
@@ -297,6 +408,7 @@ METHOD(lookip_socket_t, destroy, void,
 	private_lookip_socket_t *this)
 {
 	this->registered->destroy_function(this->registered, (void*)entry_destroy);
+	this->connected->destroy(this->connected);
 	this->mutex->destroy(this->mutex);
 	close(this->socket);
 	free(this);
@@ -315,6 +427,7 @@ lookip_socket_t *lookip_socket_create(lookip_listener_t *listener)
 		},
 		.listener = listener,
 		.registered = linked_list_create(),
+		.connected = linked_list_create(),
 		.mutex = mutex_create(MUTEX_TYPE_DEFAULT),
 	);