Add vless outbound and xudp

2022-09-12 21:59:27 +08:00
parent dfb8b5f2fa
commit 38088f28b0
12 changed files with 783 additions and 49 deletions
--- a/transport/vless/xudp.go
+++ b/transport/vless/xudp.go
@@ -0,0 +1,174 @@
+package vless
+
+import (
+	"encoding/binary"
+	"io"
+	"net"
+	"os"
+
+	"github.com/sagernet/sing/common"
+	"github.com/sagernet/sing/common/buf"
+	E "github.com/sagernet/sing/common/exceptions"
+	M "github.com/sagernet/sing/common/metadata"
+)
+
+type XUDPConn struct {
+	net.Conn
+	key            []byte
+	destination    M.Socksaddr
+	requestWritten bool
+	responseRead   bool
+}
+
+func (c *XUDPConn) ReadFrom(p []byte) (n int, addr net.Addr, err error) {
+	return 0, nil, os.ErrInvalid
+}
+
+func (c *XUDPConn) ReadPacket(buffer *buf.Buffer) (destination M.Socksaddr, err error) {
+	start := buffer.Start()
+	if !c.responseRead {
+		err = ReadResponse(c.Conn)
+		if err != nil {
+			return
+		}
+		c.responseRead = true
+		buffer.FullReset()
+	}
+	_, err = buffer.ReadFullFrom(c.Conn, 6)
+	if err != nil {
+		return
+	}
+	var length uint16
+	err = binary.Read(buffer, binary.BigEndian, &length)
+	if err != nil {
+		return
+	}
+	header, err := buffer.ReadBytes(4)
+	if err != nil {
+		return
+	}
+	switch header[2] {
+	case 1:
+		// frame new
+		return M.Socksaddr{}, E.New("unexpected frame new")
+	case 2:
+		// frame keep
+		if length != 4 {
+			_, err = buffer.ReadFullFrom(c.Conn, int(length)-2)
+			if err != nil {
+				return
+			}
+			buffer.Advance(1)
+			destination, err = AddressSerializer.ReadAddrPort(buffer)
+			if err != nil {
+				return
+			}
+		} else {
+			_, err = buffer.ReadFullFrom(c.Conn, 2)
+			if err != nil {
+				return
+			}
+			destination = c.destination
+		}
+	case 3:
+		// frame end
+		return M.Socksaddr{}, io.EOF
+	case 4:
+		// frame keep alive
+	default:
+		return M.Socksaddr{}, E.New("unexpected frame: ", buffer.Byte(2))
+	}
+	// option error
+	if header[3]&2 == 2 {
+		return M.Socksaddr{}, E.Cause(net.ErrClosed, "remote closed")
+	}
+	// option data
+	if header[3]&1 != 1 {
+		buffer.Resize(start, 0)
+		return c.ReadPacket(buffer)
+	} else {
+		err = binary.Read(buffer, binary.BigEndian, &length)
+		if err != nil {
+			return
+		}
+		buffer.Resize(start, 0)
+		_, err = buffer.ReadFullFrom(c.Conn, int(length))
+		return
+	}
+}
+
+func (c *XUDPConn) WriteTo(p []byte, addr net.Addr) (n int, err error) {
+	destination := M.SocksaddrFromNet(addr)
+	headerLen := c.frontHeadroom(AddressSerializer.AddrPortLen(destination))
+	buffer := buf.NewSize(headerLen + len(p))
+	buffer.Advance(headerLen)
+	common.Must1(buffer.Write(p))
+	err = c.WritePacket(buffer, destination)
+	if err == nil {
+		n = len(p)
+	}
+	return
+}
+
+func (c *XUDPConn) frontHeadroom(addrLen int) int {
+	if !c.requestWritten {
+		var headerLen int
+		headerLen += 1  // version
+		headerLen += 16 // uuid
+		headerLen += 1  // protobuf length
+		headerLen += 1  // command
+		headerLen += 2  // frame len
+		headerLen += 5  // frame header
+		headerLen += addrLen
+		headerLen += 2 // payload len
+		return headerLen
+	} else {
+		return 7 + addrLen + 2
+	}
+}
+
+func (c *XUDPConn) WritePacket(buffer *buf.Buffer, destination M.Socksaddr) error {
+	defer buffer.Release()
+	dataLen := buffer.Len()
+	addrLen := M.SocksaddrSerializer.AddrPortLen(destination)
+	if !c.requestWritten {
+		header := buf.With(buffer.ExtendHeader(c.frontHeadroom(addrLen)))
+		common.Must(
+			header.WriteByte(Version),
+			common.Error(header.Write(c.key)),
+			header.WriteByte(0),
+			header.WriteByte(CommandMux),
+			binary.Write(header, binary.BigEndian, uint16(5+addrLen)),
+			header.WriteByte(0),
+			header.WriteByte(0),
+			header.WriteByte(1), // frame type new
+			header.WriteByte(1), // option data
+			header.WriteByte(NetworkUDP),
+			AddressSerializer.WriteAddrPort(header, destination),
+			binary.Write(header, binary.BigEndian, uint16(dataLen)),
+		)
+		c.requestWritten = true
+	} else {
+		header := buffer.ExtendHeader(c.frontHeadroom(addrLen))
+		binary.BigEndian.PutUint16(header, uint16(5+addrLen))
+		header[2] = 0
+		header[3] = 0
+		header[4] = 2 // frame keep
+		header[5] = 1 // option data
+		header[6] = NetworkUDP
+		err := AddressSerializer.WriteAddrPort(buf.With(header[7:]), destination)
+		if err != nil {
+			return err
+		}
+		binary.BigEndian.PutUint16(header[7+addrLen:], uint16(dataLen))
+	}
+	return common.Error(c.Conn.Write(buffer.Bytes()))
+}
+
+func (c *XUDPConn) FrontHeadroom() int {
+	return c.frontHeadroom(M.MaxSocksaddrLength)
+}
+
+func (c *XUDPConn) Upstream() any {
+	return c.Conn
+}