Chore: split component to transport

transport/ssr/obfs/random_head.go

@@ -0,0 +1,71 @@
+package obfs
+
+import (
+	"encoding/binary"
+	"hash/crc32"
+	"math/rand"
+	"net"
+
+	"github.com/Dreamacro/clash/common/pool"
+)
+
+func init() {
+	register("random_head", newRandomHead, 0)
+}
+
+type randomHead struct {
+	*Base
+}
+
+func newRandomHead(b *Base) Obfs {
+	return &randomHead{Base: b}
+}
+
+type randomHeadConn struct {
+	net.Conn
+	*randomHead
+	hasSentHeader bool
+	rawTransSent  bool
+	rawTransRecv  bool
+	buf           []byte
+}
+
+func (r *randomHead) StreamConn(c net.Conn) net.Conn {
+	return &randomHeadConn{Conn: c, randomHead: r}
+}
+
+func (c *randomHeadConn) Read(b []byte) (int, error) {
+	if c.rawTransRecv {
+		return c.Conn.Read(b)
+	}
+	buf := pool.Get(pool.RelayBufferSize)
+	defer pool.Put(buf)
+	c.Conn.Read(buf)
+	c.rawTransRecv = true
+	c.Write(nil)
+	return 0, nil
+}
+
+func (c *randomHeadConn) Write(b []byte) (int, error) {
+	if c.rawTransSent {
+		return c.Conn.Write(b)
+	}
+	c.buf = append(c.buf, b...)
+	if !c.hasSentHeader {
+		c.hasSentHeader = true
+		dataLength := rand.Intn(96) + 4
+		buf := pool.Get(dataLength + 4)
+		defer pool.Put(buf)
+		rand.Read(buf[:dataLength])
+		binary.LittleEndian.PutUint32(buf[dataLength:], 0xffffffff-crc32.ChecksumIEEE(buf[:dataLength]))
+		_, err := c.Conn.Write(buf)
+		return len(b), err
+	}
+	if c.rawTransRecv {
+		_, err := c.Conn.Write(c.buf)
+		c.buf = nil
+		c.rawTransSent = true
+		return len(b), err
+	}
+	return len(b), nil
+}