Work-in-progress server start/stop.

client.go

@@ -160,7 +160,7 @@ func (client *Client) disconnect(kicked bool) {
 	}
 }
 
-// Disconnect a client (client disconnected)
+// Disconnect a client (client requested or server shutdown)
 func (client *Client) Disconnect() {
 	client.disconnect(false)
 }

grumble.go

@@ -195,7 +195,10 @@ func main() {
 				log.Fatalf("Unable to freeze server to disk: %v", err.Error())
 			}
 			servers[s.Id] = s
-			go s.ListenAndMurmur()
+			err = s.Start()
+			if err != nil {
+				log.Printf("Unable to start server %v: %v", s.Id, err.Error())
+			}
 		}
 	}
 
@@ -207,10 +210,15 @@ func main() {
 		}
 
 		servers[s.Id] = s
-
 		os.Mkdir(filepath.Join(Args.DataDir, fmt.Sprintf("%v", 1)), 0750)
-		s.FreezeToFile()
-		go s.ListenAndMurmur()
+		err = s.FreezeToFile()
+		if err != nil {
+			log.Fatalf("Unable to freeze newly created server to disk: %v", err.Error())
+		}
+		err = s.Start()
+		if err != nil {
+			log.Fatal("Unable to start newly created server: %v", err.Error())
+		}
 	}
 
 	// If any servers were loaded, launch the signal

message.go

@@ -19,17 +19,8 @@ import (
 
 type Message struct {
 	buf    []byte
-
-	// Kind denotes a message kind for TCP packets. This field
-	// is ignored for UDP packets.
 	kind   uint16
-
-	// For UDP datagrams one of these fields have to be filled out.
-	// If there is no connection established, address must be used.
-	// If the datagram comes from an already-connected client, the
-	// client field should point to that client.
 	client *Client
-	address net.Addr
 }
 
 type VoiceBroadcast struct {

server.go

@@ -56,11 +56,15 @@ type KeyValuePair struct {
 // A Murmur server instance
 type Server struct {
 	Id int64
-	listener tls.Listener
+
+	tcpl    *net.TCPListener
+	tlsl    *tls.Listener
 	address string
 	port    int
 	udpconn *net.UDPConn
 	tlscfg  *tls.Config
+	bye     chan bool
+	netwg   sync.WaitGroup
 	running bool
 
 	incoming       chan *Message
@@ -148,6 +152,7 @@ func NewServer(id int64, addr string, port int) (s *Server, err error) {
 	s.hclients = make(map[string][]*Client)
 	s.hpclients = make(map[string]*Client)
 
+	s.bye = make(chan bool)
 	s.incoming = make(chan *Message)
 	s.voicebroadcast = make(chan *VoiceBroadcast)
 	s.cfgUpdate = make(chan *KeyValuePair)
@@ -345,10 +350,13 @@ func (server *Server) UnlinkChannels(channel *Channel, other *Channel) {
 // This is the synchronous handler goroutine.
 // Important control channel messages are routed through this Goroutine
 // to keep server state synchronized.
-func (server *Server) handler() {
+func (server *Server) handlerLoop() {
 	regtick := time.Tick((3600 + ((server.Id * 60) % 600)) * 1e9)
 	for {
 		select {
+		// We're done. Stop the server's event handler
+		case <-server.bye:
+			return
 		// Control channel messages
 		case msg := <-server.incoming:
 			client := msg.client
@@ -863,19 +871,6 @@ func (server *Server) handleIncomingMessage(client *Client, msg *Message) {
 	}
 }
 
-func (s *Server) SetupUDP() (err error) {
-	addr := &net.UDPAddr{
-		net.ParseIP(s.address),
-		s.port,
-	}
-	s.udpconn, err = net.ListenUDP("udp", addr)
-	if err != nil {
-		return
-	}
-
-	return
-}
-
 // Send the content of buf as a UDP packet to addr.
 func (s *Server) SendUDP(buf []byte, addr *net.UDPAddr) (err error) {
 	_, err = s.udpconn.WriteTo(buf, addr)
@@ -883,13 +878,18 @@ func (s *Server) SendUDP(buf []byte, addr *net.UDPAddr) (err error) {
 }
 
 // Listen for and handle UDP packets.
-func (server *Server) ListenUDP() {
+func (server *Server) udpListenLoop() {
+	defer server.netwg.Done()
+
 	buf := make([]byte, UDPPacketSize)
 	for {
 		nread, remote, err := server.udpconn.ReadFrom(buf)
 		if err != nil {
-			// Not much to do here. This is bad, of course. Should we panic this server instance?
+			if isTimeout(err) {
 				continue
+			} else {
+				return
+			}
 		}
 
 		udpaddr, ok := remote.(*net.UDPAddr)
@@ -917,7 +917,7 @@ func (server *Server) ListenUDP() {
 
 			err = server.SendUDP(buffer.Bytes(), udpaddr)
 			if err != nil {
-				server.Print("Unable to write UDP packet: %v", err.Error())
+				return
 			}
 
 		} else {
@@ -1153,93 +1153,180 @@ func (server *Server) FilterText(text string) (filtered string, err error) {
 }
 
 // The accept loop of the server.
-func (s *Server) ListenAndMurmur() {
-	// Launch the event handler goroutine
-	go s.handler()
+func (server *Server) acceptLoop() {
+	defer server.netwg.Done()
 
-	host := s.cfg.StringValue("Address")
-	if host != "" {
-		s.address = host
-	}
-	port := s.cfg.IntValue("Port")
-	if port != 0 {
-		s.port = port
-	}
-
-	s.running = true
-
-	// Setup our UDP listener and spawn our reader and writer goroutines
-	s.SetupUDP()
-	go s.ListenUDP()
-
-	// Create a new listening TLS socket.
-	certFn := filepath.Join(Args.DataDir, "cert.pem")
-	keyFn := filepath.Join(Args.DataDir, "key.pem")
-	cert, err := tls.LoadX509KeyPair(certFn, keyFn)
-	if err != nil {
-		s.Printf("Unable to load x509 key pair: %v", err)
-		return
-	}
-
-	cfg := new(tls.Config)
-	cfg.Certificates = append(cfg.Certificates, cert)
-	cfg.AuthenticateClient = true
-	s.tlscfg = cfg
-
-	tl, err := net.ListenTCP("tcp", &net.TCPAddr{
-		net.ParseIP(s.address),
-		s.port,
-	})
-	if err != nil {
-		s.Printf("Cannot bind: %s\n", err)
-		return
-	}
-
-	listener := tls.NewListener(tl, s.tlscfg)
-
-	s.Printf("Started: listening on %v", tl.Addr())
-
-	// Open a fresh freezer log
-	err = s.openFreezeLog()
-	if err != nil {
-		s.Fatal(err)
-	}
-
-	// Update server registration if needed.
-	go func() {
-		time.Sleep((60 + s.Id*10) * 1e9)
-		s.RegisterPublicServer()
-	}()
-
-	// The main accept loop. Basically, we block
-	// until we get a new client connection, and
-	// when we do get a new connection, we spawn
-	// a new Go-routine to handle the client.
 	for {
 		// New client connected
-		conn, err := listener.Accept()
+		conn, err := server.tlsl.Accept()
 		if err != nil {
-			s.Printf("Unable to accept new client: %v", err)
+			if isTimeout(err) {
 				continue
+			} else {
+				return
+			}
 		}
 
 		// Is the client banned?
 		// fixme(mkrautz): Clean up expired bans
-		if s.IsBanned(conn) {
-			s.Printf("Rejected client %v: Banned", conn.RemoteAddr())
+		if server.IsBanned(conn) {
+			server.Printf("Rejected client %v: Banned", conn.RemoteAddr())
 			err := conn.Close()
 			if err != nil {
-				s.Printf("Unable to close connection: %v", err)
+				server.Printf("Unable to close connection: %v", err)
 			}
 			continue
 		}
 
 		// Create a new client connection from our *tls.Conn
 		// which wraps net.TCPConn.
-		err = s.NewClient(conn)
+		err = server.NewClient(conn)
 		if err != nil {
-			s.Printf("Unable to handle new client: %v", err)
+			server.Printf("Unable to handle new client: %v", err)
 			continue
 		}
 	}
 }
+
+// The isTimeout function checks whether a
+// network error is a timeout.
+func isTimeout(err error) bool {
+	if e, ok := err.(net.Error); ok {
+		return e.Timeout()
+	}
+	return false
+}
+
+// Start the server.
+func (server *Server) Start() (err error) {
+	if server.running {
+		return errors.New("already running")
+	}
+
+	host := server.cfg.StringValue("Address")
+	if host != "" {
+		server.address = host
+	}
+	port := server.cfg.IntValue("Port")
+	if port != 0 {
+		server.port = port
+	}
+
+	// Setup our UDP listener
+	addr := &net.UDPAddr{
+		net.ParseIP(server.address),
+		server.port,
+	}
+	server.udpconn, err = net.ListenUDP("udp", addr)
+	if err != nil {
+		return err
+	}
+	err = server.udpconn.SetReadTimeout(1e9)
+	if err != nil {
+		return err
+	}
+
+	// Set up our TCP connection
+	server.tcpl, err = net.ListenTCP("tcp", &net.TCPAddr{
+		net.ParseIP(server.address),
+		server.port,
+	})
+	if err != nil {
+		return err
+	}
+	err = server.tcpl.SetTimeout(1e9)
+	if err != nil {
+		return err
+	}
+
+	// Wrap a TLS listener around the TCP connection
+	certFn := filepath.Join(Args.DataDir, "cert.pem")
+	keyFn := filepath.Join(Args.DataDir, "key.pem")
+	cert, err := tls.LoadX509KeyPair(certFn, keyFn)
+	if err != nil {
+		return err
+	}
+	server.tlscfg = &tls.Config{
+		Certificates:       []tls.Certificate{cert},
+		AuthenticateClient: true,
+	}
+	server.tlsl = tls.NewListener(server.tcpl, server.tlscfg)
+
+	server.Printf("Started: listening on %v", server.tcpl.Addr())
+	server.running = true
+
+	// Open a fresh freezer log
+	err = server.openFreezeLog()
+	if err != nil {
+		server.Fatal(err)
+	}
+
+	// Launch the event handler goroutine
+	go server.handlerLoop()
+
+	// Add the two network receiver goroutines to the net waitgroup
+	// and launch them.
+	//
+	// We use the waitgroup to provide a blocking Stop() method
+	// for the servers. Each network goroutine defers a call to
+	// netwg.Done(). In the Stop() we close all the connections
+	// and call netwg.Wait() to wait for the goroutines to end.
+	server.netwg.Add(2)
+	go server.udpListenLoop()
+	go server.acceptLoop()
+
+	// Schedule a server registration update (if needed)
+	go func() {
+		time.Sleep((60 + server.Id*10) * 1e9)
+		server.RegisterPublicServer()
+	}()
+
+	return nil
+}
+
+// Stop the server.
+func (server *Server) Stop() (err error) {
+	if !server.running {
+		return errors.New("server not running")
+	}
+
+	// Stop the handler goroutine and disconnect all
+	// clients
+	server.bye <- true
+	for _, client := range server.clients {
+		client.Disconnect()
+	}
+
+	// Close the TLS listener and the TCP listener
+	err = server.tlsl.Close()
+	if err != nil {
+		return err
+	}
+	err = server.tcpl.Close()
+	if err != nil {
+		return err
+	}
+
+	// Close the UDP connection
+	err = server.udpconn.Close()
+	if err != nil {
+		return err
+	}
+
+	// Since we'll (on some OSes) have to wait for the network
+	// goroutines to end, we might as well use the time to store
+	// a full server freeze to disk.
+	err = server.FreezeToFile()
+	if err != nil {
+		server.Fatal(err)
+	}
+
+	// Wait for the two network receiver
+	// goroutines end.
+	server.netwg.Wait()
+
+	server.running = false
+	server.Printf("Stopped")
+
+	return nil
+}

ssh.go

@@ -227,9 +227,14 @@ func StartServerCmd(reply SshCmdReply, args []string) error {
 		return errors.New("no such server")
 	}
 
-	_ = server
+	err = server.Start()
+	if err != nil {
+		return fmt.Errorf("unable to start: %v", err.Error())
+	}
 
-	return errors.New("not implemented")
+	reply.WriteString(fmt.Sprintf("[%v] Started\r\n", serverId))
+
+	return nil
 }
 
 func StopServerCmd(reply SshCmdReply, args []string) error {
@@ -247,9 +252,14 @@ func StopServerCmd(reply SshCmdReply, args []string) error {
 		return errors.New("no such server")
 	}
 
-	_ = server
+	err = server.Stop()
+	if err != nil {
+		return fmt.Errorf("unable to stop: %v", err.Error())
+	}
 
-	return errors.New("not implemented")
+	reply.WriteString(fmt.Sprintf("[%v] Stopped\r\n", serverId))
+
+	return nil
 }
 
 func SetSuperUserPasswordCmd(reply SshCmdReply, args []string) error {