fix: kcp 协议内部日志细节

cmd/internal/transport/kcp_packet_metadata.go

@@ -0,0 +1,55 @@
+package transport
+
+import "encoding/binary"
+
+const kcpPacketHeaderSize = 24
+
+func parseKCPPacketMetadata(packet []byte) (*uint32, []KCPPacketDebugSegment) {
+	conv := parseKCPConversationID(packet)
+	segments, ok := parseKCPPacketSegments(packet)
+	if !ok {
+		return conv, nil
+	}
+	return conv, segments
+}
+
+func parseKCPConversationID(packet []byte) *uint32 {
+	if len(packet) < 4 {
+		return nil
+	}
+	conv := binary.LittleEndian.Uint32(packet[:4])
+	return &conv
+}
+
+func parseKCPPacketSegments(packet []byte) ([]KCPPacketDebugSegment, bool) {
+	if len(packet) == 0 {
+		return nil, false
+	}
+
+	data := packet
+	segments := make([]KCPPacketDebugSegment, 0, 1)
+	for len(data) > 0 {
+		if len(data) < kcpPacketHeaderSize {
+			return nil, false
+		}
+
+		segmentLen := binary.LittleEndian.Uint32(data[20:])
+		totalLen := kcpPacketHeaderSize + int(segmentLen)
+		if len(data) < totalLen {
+			return nil, false
+		}
+
+		segments = append(segments, KCPPacketDebugSegment{
+			Cmd: data[4],
+			Frg: data[5],
+			Wnd: binary.LittleEndian.Uint16(data[6:8]),
+			SN:  binary.LittleEndian.Uint32(data[12:16]),
+			UNA: binary.LittleEndian.Uint32(data[16:20]),
+			Len: segmentLen,
+		})
+
+		data = data[totalLen:]
+	}
+
+	return segments, true
+}