Add client brand

pkg/edition/java/proto/packet/plugin/util.go

@@ -117,7 +117,7 @@ func RewriteMinecraftBrand(message *Message, protocol proto.Protocol) *Message {
 		return message
 	}
 
-	currentBrand := readBrandMessage(message.Data)
+	currentBrand := ReadBrandMessage(message.Data)
 	rewrittenBrand := fmt.Sprintf("%s (Gate by Minekube)", currentBrand)
 
 	rewrittenBuf := new(bytes.Buffer)
@@ -133,11 +133,14 @@ func RewriteMinecraftBrand(message *Message, protocol proto.Protocol) *Message {
 	}
 }
 
+// ReadBrandMessage reads the brand message from the given packet data.
+// The returned string will be empty if the data is invalid.
+//
 // Some clients (mostly poorly-implemented bots) do not send validly-formed brand messages.
 // In order to accommodate their broken behavior, we'll first try to read in the 1.8 format, and
 // if that fails, treat it as a 1.7-format message (which has no prefixed length).
 // (The message the proxy sends will be in the correct format depending on the protocol.)
-func readBrandMessage(data []byte) string {
+func ReadBrandMessage(data []byte) string {
 	s, err := util.ReadString(bytes.NewReader(data))
 	if err != nil {
 		s, _ = util.ReadStringWithoutLen(bytes.NewReader(data))

pkg/edition/java/proxy/player.go

@@ -75,6 +75,7 @@ type Player interface {
 	// SendActionBar sends an action bar to the player.
 	SendActionBar(msg component.Component) error
 	TabList() tablist.TabList // Returns the player's tab list.
+	ClientBrand() string      // Returns the player's client brand. Empty if unspecified.
 
 	// Looking for title or bossbar methods? See the title and bossbar packages.
 }
@@ -107,6 +108,7 @@ type connectedPlayer struct {
 	previousResourceResponse *bool
 	pendingResourcePack      *ResourcePackInfo
 	appliedResourcePack      *ResourcePackInfo
+	clientBrand              string // may be empty
 
 	serversToTry []string // names of servers to try if we got disconnected from previous
 	tryIndex     int
@@ -699,3 +701,16 @@ func (p *connectedPlayer) switchToConfigState(pkt *cfgpacket.StartUpdate) {
 	}
 	p.SetState(state.Config)
 }
+
+func (p *connectedPlayer) ClientBrand() string {
+	p.mu.RLock()
+	defer p.mu.RUnlock()
+	return p.clientBrand
+}
+
+// setClientBrand sets the client brand of the player.
+func (p *connectedPlayer) setClientBrand(brand string) {
+	p.mu.Lock()
+	p.clientBrand = brand
+	p.mu.Unlock()
+}

pkg/edition/java/proxy/session_client_play.go

@@ -232,7 +232,8 @@ func (c *clientPlaySessionHandler) handlePluginMessage(packet *plugin.Message) {
 	} else if plugin.IsUnregister(packet) {
 		_ = backendConn.WritePacket(packet)
 	} else if plugin.McBrand(packet) {
-		// TODO read brand message & fire PlayerClientBrandEvent & cache client brand
+		// TODO fire PlayerClientBrandEvent & cache client brand
+		c.player.setClientBrand(plugin.ReadBrandMessage(packet.Data))
 		_ = backendConn.WritePacket(plugin.RewriteMinecraftBrand(packet, c.player.Protocol()))
 	} else {
 		serverConnPhase := serverConn.phase()