Parse the FML|HS ServerHello message

Author: iceiix

src/server/mod.rs

@@ -679,6 +679,37 @@ impl Server {
 
     fn on_plugin_message_clientbound(&mut self, channel: &str, data: &[u8]) {
         println!("Received plugin message: channel={}, data={:?}", channel, data);
+
+        match channel {
+            // TODO: "REGISTER" => 
+            // TODO: "UNREGISTER" =>
+            "FML|HS" => {
+                // https://wiki.vg/Minecraft_Forge_Handshake
+                let discriminator = data[0];
+
+                match discriminator {
+                    0 => {
+                        // ServerHello
+                        let fml_protocol_version = data[1];
+                        let dimension = if fml_protocol_version > 1 {
+                            use byteorder::{BigEndian, ReadBytesExt};
+                            let dimension = (&data[2..2 + 4]).read_u32::<BigEndian>().unwrap();
+                            Some(dimension)
+                        } else {
+                            None
+                        };
+
+                        println!("FML|HS ServerHello: fml_protocol_version={}, dimension={:?}", fml_protocol_version, dimension);
+
+                        // TODO: send reply
+                    },
+                    _ => {
+                        println!("Unhandled FML|HS packet: discriminator={}", discriminator);
+                    }
+                }
+            }
+            _ => ()
+        }
     }
 
     fn on_game_join_i32_viewdistance(&mut self, join: packet::play::clientbound::JoinGame_i32_ViewDistance) {