Implement 40250 classic client port

project/net/channel_status.gd

@@ -4,13 +4,16 @@
 #   add_child(cs)
 #   cs.query(host, port, func(map): ...)   # map: { port:int -> status:int }
 #
-# 明文 TCP（无 libsodium）：连上任一频道端口 → 发 CG_STATE_CHECKER(0x000F,len 4) →
-# 跳过其它包直到 GC_RESPOND_CHANNELSTATUS(0x0010) → 读 int32 count → count × {i16 port, u8 status}。
+# 明文 TCP（无 libsodium）：m2dev 发 CG_STATE_CHECKER(0x000F,len 4)，40250 classic
+# 发单字节 CG_STATE_CHECKER(206)；服务端均返回频道条目。classic 响应是
+# [210][int32 count][count × {i16 port, u8 status}]，m2dev 则是带 u16 header/length 的包。
 # status：0 关 / 1 正常 / 2 忙 / 3 满（Metin2 约定，非在线人数——那要改服务器）。
 extends Node
 
 const CG_STATE_CHECKER := 0x000F
 const GC_RESPOND_CHANNELSTATUS := 0x0010
+const CLASSIC_CG_STATE_CHECKER := 206
+const CLASSIC_GC_RESPOND_CHANNELSTATUS := 210
 
 const STATUS_TEXT := {0: "关闭", 1: "正常", 2: "拥挤", 3: "爆满"}
 
@@ -20,11 +23,15 @@ var _peer: StreamPeerTCP
 var _cb: Callable
 var _deadline := 0.0
 var _sent := false
+var _classic := false
+var _classic_rx := PackedByteArray()
 
 func query(host: String, port: int, callback: Callable = Callable(), timeout_s := 3.0) -> void:
 	_cb = callback
 	_peer = StreamPeerTCP.new()
 	_sent = false
+	_classic = OS.get_environment("MT_PROTOCOL") == "classic"
+	_classic_rx = PackedByteArray()
 	_deadline = _now() + timeout_s
 	if _peer.connect_to_host(host, port) != OK:
 		_finish({})
@@ -48,14 +55,53 @@ func _process(_dt: float) -> void:
 	if st != StreamPeerTCP.STATUS_CONNECTED:
 		return
 	if not _sent:
-		var req := PackedByteArray()
-		req.resize(4)
-		req.encode_u16(0, CG_STATE_CHECKER)
-		req.encode_u16(2, 4)
+		var req := PackedByteArray([CLASSIC_CG_STATE_CHECKER]) if _classic else PackedByteArray()
+		if not _classic:
+			req.resize(4)
+			req.encode_u16(0, CG_STATE_CHECKER)
+			req.encode_u16(2, 4)
 		_peer.put_data(req)
 		_sent = true
 	# 攒够一个包就解析
-	_try_parse()
+	if _classic:
+		_try_parse_classic()
+	else:
+		_try_parse()
+
+func _try_parse_classic() -> void:
+	var avail := _peer.get_available_bytes()
+	if avail > 0:
+		var r: Array = _peer.get_data(avail)
+		if r[0] != OK:
+			_finish({})
+			return
+		_classic_rx.append_array(r[1])
+
+	# The stock checker reads a byte header, then an int32 count. A regular
+	# game handshake may arrive while waiting, so discard known fixed packets.
+	while not _classic_rx.is_empty() and _classic_rx[0] != CLASSIC_GC_RESPOND_CHANNELSTATUS:
+		var skip := 1
+		match int(_classic_rx[0]):
+			0xFE: skip = 13 # GC_HANDSHAKE
+			0xFC: skip = 1  # GC_TIME_SYNC
+		if _classic_rx.size() < skip:
+			return
+		_classic_rx = _classic_rx.slice(skip)
+	if _classic_rx.size() < 5:
+		return
+	var count := _classic_rx.decode_s32(1)
+	if count < 0 or count > 4096:
+		_finish({})
+		return
+	var total := 5 + count * 3
+	if _classic_rx.size() < total:
+		return
+	var out := {}
+	var off := 5
+	for i in count:
+		out[_classic_rx.decode_s16(off)] = _classic_rx.decode_u8(off + 2)
+		off += 3
+	_finish(out)
 
 func _try_parse() -> void:
 	var avail := _peer.get_available_bytes()