新增协议SBProxy-MC

protocol/sbproxy/utils.go

@@ -0,0 +1,62 @@
+package sbproxy
+
+import (
+	"io"
+)
+
+func ReadVarInt(r io.Reader) (int32, int, error) {
+	var val int32
+	var size int
+	for {
+		var b [1]byte
+		if _, err := r.Read(b[:]); err != nil {
+			return 0, 0, err
+		}
+		d := b[0]
+		val |= int32(d&0x7F) << (7 * size)
+		size++
+		if size > 5 {
+			return 0, 0, io.ErrUnexpectedEOF
+		}
+		if d&0x80 == 0 {
+			break
+		}
+	}
+	return val, size, nil
+}
+
+func WriteVarInt(w io.Writer, val int32) int {
+	buf := make([]byte, 5)
+	size := 0
+	for {
+		b := byte(val & 0x7F)
+		val >>= 7
+		if val != 0 {
+			b |= 0x80
+		}
+		buf[size] = b
+		size++
+		if val == 0 {
+			break
+		}
+	}
+	w.Write(buf[:size])
+	return size
+}
+
+func ReadString(r io.Reader) (string, error) {
+	length, _, err := ReadVarInt(r)
+	if err != nil {
+		return "", err
+	}
+	buf := make([]byte, length)
+	if _, err := io.ReadFull(r, buf); err != nil {
+		return "", err
+	}
+	return string(buf), nil
+}
+
+func WriteString(w io.Writer, s string) {
+	WriteVarInt(w, int32(len(s)))
+	w.Write([]byte(s))
+}