Major update: custom error message.

+ A submodule called mcchat is added, to handle chat message part.
+ Config file updated, custom error message syntax added.
+ Favicon part is added, but currently not functional.
+ Config is now (not completely) validated after loaded.
* Fix: for status request, kick message is now a valid status response.
* Tried to fix that sometimes disconnection reason is netty exception.
! Seems hover and click events in status response is ignored, don't know
  if there is any way to make them work.

mcchat/mcchat.go

@@ -34,11 +34,11 @@ var color_string = [...]string{
 }
 
 type Event struct {
-	Action string
-	Value  string
+	Action string `json:"action"`
+	Value  string `json:"value"`
 }
 
-type Style int32
+type Style int
 
 const (
 	BOLD Style = 1 << iota
@@ -65,12 +65,12 @@ const (
 )
 
 type ChatMsg struct {
-	Text          string
-	Bold          bool       `json:",omitempty"`
-	Italic        bool       `json:",omitempty"`
-	Underlined    bool       `json:",omitempty"`
-	Strikethrough bool       `json:",omitempty"`
-	Color         string     `json:",omitempty"`
+	Text          string     `json:"text"`
+	Bold          bool       `json:"bold,omitempty"`
+	Italic        bool       `json:"italic,omitempty"`
+	Underlined    bool       `json:"underlined,omitempty"`
+	Strikethrough bool       `json:"strikethrough,omitempty"`
+	Color         string     `json:"color,omitempty"`
 	OnClick       *Event     `json:"clickEvent,omitempty"`
 	OnHover       *Event     `json:"hoverEvent,omitempty"`
 	ExtraMsg      []*ChatMsg `json:"extra,omitempty"`
@@ -149,6 +149,12 @@ func (msg *ChatMsg) ClickTarget(target string) {
 	}
 }
 
+func (msg *ChatMsg) AppendMsg(message string) (new_msg *ChatMsg) {
+	new_msg = NewMsg(message)
+	msg.ExtraMsg = append(msg.ExtraMsg, new_msg)
+	return
+}
+
 func (msg *ChatMsg) AsJson() (json_data []byte) {
 	json_data, _ = json.Marshal(msg)
 	return
@@ -163,3 +169,12 @@ func (msg *ChatMsg) AsChatString() (chat_string []byte) {
 	buffer.Write(json_data)
 	return buffer.Bytes()
 }
+
+func GetColor(color string) (res Style) {
+	for idx, val := range color_string {
+		if val == color {
+			return Style((idx << 5) | 16)
+		}
+	}
+	return -1
+}

minegate/conf.go

@@ -7,8 +7,8 @@ import (
 )
 
 type Config struct {
-	Listen_addr string     "listen"
-	Upstream    []Upstream "upstreams"
+	Listen_addr string      "listen"
+	Upstream    []*Upstream "upstreams"
 }
 
 var config Config
@@ -22,6 +22,12 @@ func SetConfig(conf string) {
 	config_file = conf
 }
 
+func validateConfig() {
+	for _, upstream := range config.Upstream {
+		upstream.Validate()
+	}
+}
+
 func ConfInit() {
 	Debug("call: ConfInit")
 	content, err := ioutil.ReadFile(config_file)
@@ -34,6 +40,7 @@ func ConfInit() {
 	if err != nil {
 		Fatalf("error when parsing config file %s: %s", config_file, err.Error())
 	}
+	validateConfig()
 	Info("config loaded.")
 	Info("server listen on: " + config.Listen_addr)
 	Infof("%d upstream server(s) found", len(config.Upstream))
@@ -60,6 +67,7 @@ func ConfReload() {
 	if err != nil {
 		Errorf("error when parsing config file %s: %s", config_file, err.Error())
 	}
+	validateConfig()
 	Info("config reloaded.")
 	if config.Listen_addr != prev_listen {
 		Warnf("config reload will not reopen server socket, thus no effect on listen address")

minegate/config.yml

@@ -3,16 +3,20 @@ upstreams:
   -
     hostname: server1.local
     upstream: 127.0.0.1:25568
-    motd: first sample server!
-    limit: 20
+    onerror:
+      text: 'Server is down :P'
+      color: red
+      bold: true
+      hover: 'Hover Test!'
+      click: 'https://jackyyf.com/'
   -
     hostname: '*.local'
     upstream: 127.0.0.1:25566
-    motd: all local server!
-    limit: 10
+    onerror:
+      text: 'Hey, why do you want to go to this server? It does not exists!'
 # If no server matched, player will be kicked, you can use a server with hostname: * to avoid such cases.
   -
     hostname: '*'
     upstream: 127.0.0.1:25567
-    motd: default fallback server!
-    limit: 100
+    onerror:
+      text: 'Fallback is just a joke dude!'

minegate/handler.go

@@ -8,18 +8,21 @@ import (
 
 var total_online uint32
 
-type Handshake struct {
-	version int
-	host    string
-	port    uint16
-	isPing  bool
-}
-
-func handlePing(conn net.Conn, upstream *Upstream) {
-
+func WaitTillClose(conn *net.TCPConn) {
+	buff := Allocate()
+	for {
+		n, err := conn.Read(buff)
+		if n > 0 {
+			continue
+		}
+		if err != nil {
+			conn.Close()
+			return
+		}
+	}
 }
 
-func ReadTo(conn net.Conn, queue BufferQueue, notifyqueue chan byte) {
+func ReadTo(conn *net.TCPConn, queue BufferQueue, notifyqueue chan byte) {
 	for {
 		buff := Allocate()
 		n, err := conn.Read(buff)
@@ -28,6 +31,7 @@ func ReadTo(conn net.Conn, queue BufferQueue, notifyqueue chan byte) {
 			case <-notifyqueue:
 				close(queue)
 				Info("recv side signaled, closing.")
+				Free(buff)
 				return
 			case queue <- buff[:n]:
 				Debugf("recv %d bytes from %s", n, conn.RemoteAddr())
@@ -43,7 +47,7 @@ func ReadTo(conn net.Conn, queue BufferQueue, notifyqueue chan byte) {
 	}
 }
 
-func WriteTo(conn net.Conn, queue BufferQueue, notifyqueue chan byte) {
+func WriteTo(conn *net.TCPConn, queue BufferQueue, notifyqueue chan byte) {
 	for {
 		select {
 		case buff := <-queue:
@@ -55,6 +59,7 @@ func WriteTo(conn net.Conn, queue BufferQueue, notifyqueue chan byte) {
 				select {
 				case <-notifyqueue:
 					close(queue)
+					Free(buff)
 					return
 				default:
 				}
@@ -70,17 +75,47 @@ func WriteTo(conn net.Conn, queue BufferQueue, notifyqueue chan byte) {
 	}
 }
 
-func startProxy(conn net.Conn, upstream *Upstream, initial []byte) {
-	if _, _, err := net.SplitHostPort(upstream.Server); err != nil {
-		upstream.Server += ":25565"
+func startProxy(conn *net.TCPConn, upstream *Upstream, initial_pkt *Handshake, initial []byte, after_initial []byte) {
+	addr, perr := net.ResolveTCPAddr("tcp", upstream.Server)
+	var err error
+	var upconn *net.TCPConn
+	if perr == nil {
+		upconn, err = net.DialTCP("tcp", nil, addr)
 	}
-	upconn, err := net.Dial("tcp", upstream.Server)
-	if err != nil {
+	buff := Allocate()
+	if len(after_initial) > 0 {
+		if !initial_pkt.isPing || len(after_initial) != 2 {
+			// ping request
+			copy(buff, after_initial)
+			Warnf("has %d bytes extra data!", len(after_initial))
+		}
+	}
+	if err != nil || perr != nil {
+		if err == nil {
+			err = perr
+		}
 		Errorf("Unable to connect to upstream %s", upstream.Server)
-		KickClient(conn, "502 Bad Gateway.")
+		// KickClient(conn, "502 Bad Gateway.")
+		if initial_pkt.isPing {
+			Info("ping packet")
+			ResponsePing(conn, upstream.ChatMsg)
+			n := len(after_initial)
+			t, _ := conn.Read(buff[n:])
+			Debugf("recved %d bytes", t)
+			n += t
+			Debugf("ping.packet(%dbytes): "+string(buff[:n]), n)
+			_, _ = conn.Write(buff[:n])
+			WaitTillClose(conn)
+		} else {
+			Info("login packet")
+			Debug("kick.msg = " + string(upstream.ChatMsg.AsChatString()))
+			KickClientRaw(conn, upstream.ChatMsg.AsChatString())
+			WaitTillClose(conn)
+		}
 		conn.Close()
 		return
 	}
+	upconn.SetNoDelay(false)
 	c2squeue := NewBufferQueue(4)
 	s2cqueue := NewBufferQueue(32)
 	c2sstatus := make(chan byte, 1)
@@ -93,7 +128,11 @@ func startProxy(conn net.Conn, upstream *Upstream, initial []byte) {
 }
 
 func ServerSocket() {
-	s, err := net.Listen("tcp", config.Listen_addr)
+	addr, err := net.ResolveTCPAddr("tcp", config.Listen_addr)
+	if err != nil {
+		Fatalf("error parse address %s: %s", config.Listen_addr, err.Error())
+	}
+	s, err := net.ListenTCP("tcp", addr)
 	if err != nil {
 		Fatalf("error listening on %s: %s", config.Listen_addr, err.Error())
 	}
@@ -102,17 +141,18 @@ func ServerSocket() {
 	// 4 MB pool
 	InitPool(1024, 4096)
 	for {
-		conn, err := s.Accept()
+		conn, err := s.AcceptTCP()
 		if err != nil {
 			Warnf("listen_socket: error when accepting: %s", err.Error())
 			continue
 		}
+		conn.SetNoDelay(false)
 		Infof("listen_socket: new client %s", conn.RemoteAddr())
 		go ClientSocket(conn)
 	}
 }
 
-func ClientSocket(conn net.Conn) {
+func ClientSocket(conn *net.TCPConn) {
 	buff := Allocate()
 	orig := buff
 	n, err := conn.Read(buff)
@@ -180,5 +220,5 @@ func ClientSocket(conn net.Conn) {
 		conn.Close()
 		return
 	}
-	go startProxy(conn, upstream, orig[:lenlen+curlen])
+	go startProxy(conn, upstream, init_packet, orig[:lenlen+curlen], pkt[pktlen:curlen])
 }