shadowsockets fullcone outbound support

proxy/shadowsocks/client.go

@@ -8,6 +8,7 @@ import (
 	"github.com/v2fly/v2ray-core/v5/common"
 	"github.com/v2fly/v2ray-core/v5/common/buf"
 	"github.com/v2fly/v2ray-core/v5/common/net"
+	"github.com/v2fly/v2ray-core/v5/common/net/packetaddr"
 	"github.com/v2fly/v2ray-core/v5/common/protocol"
 	"github.com/v2fly/v2ray-core/v5/common/retry"
 	"github.com/v2fly/v2ray-core/v5/common/session"
@@ -16,9 +17,10 @@ import (
 	"github.com/v2fly/v2ray-core/v5/features/policy"
 	"github.com/v2fly/v2ray-core/v5/transport"
 	"github.com/v2fly/v2ray-core/v5/transport/internet"
+	"github.com/v2fly/v2ray-core/v5/transport/internet/udp"
 )
 
-// Client is an inbound handler for Shadowsocks protocol
+// Client is a inbound handler for Shadowsocks protocol
 type Client struct {
 	serverPicker  protocol.ServerPicker
 	policyManager policy.Manager
@@ -99,6 +101,28 @@ func (c *Client) Process(ctx context.Context, link *transport.Link, dialer inter
 	ctx, cancel := context.WithCancel(ctx)
 	timer := signal.CancelAfterInactivity(ctx, cancel, sessionPolicy.Timeouts.ConnectionIdle)
 
+	if packetConn, err := packetaddr.ToPacketAddrConn(link, destination); err == nil {
+		requestDone := func() error {
+			protocolWriter := &UDPWriter{
+				Writer:  conn,
+				Request: request,
+			}
+			return udp.CopyPacketConn(protocolWriter, packetConn, udp.UpdateActivity(timer))
+		}
+		responseDone := func() error {
+			protocolReader := &UDPReader{
+				Reader: conn,
+				User:   user,
+			}
+			return udp.CopyPacketConn(packetConn, protocolReader, udp.UpdateActivity(timer))
+		}
+		responseDoneAndCloseWriter := task.OnSuccess(responseDone, task.Close(link.Writer))
+		if err := task.Run(ctx, requestDone, responseDoneAndCloseWriter); err != nil {
+			return newError("connection ends").Base(err)
+		}
+		return nil
+	}
+
 	if request.Command == protocol.RequestCommandTCP {
 		requestDone := func() error {
 			defer timer.SetTimeout(sessionPolicy.Timeouts.DownlinkOnly)

proxy/shadowsocks/protocol.go

@@ -6,6 +6,7 @@ import (
 	"crypto/sha256"
 	"hash/crc32"
 	"io"
+	gonet "net"
 
 	"github.com/v2fly/v2ray-core/v5/common"
 	"github.com/v2fly/v2ray-core/v5/common/buf"
@@ -253,6 +254,23 @@ func (v *UDPReader) ReadMultiBuffer() (buf.MultiBuffer, error) {
 	return buf.MultiBuffer{payload}, nil
 }
 
+func (v *UDPReader) ReadFrom(p []byte) (n int, addr gonet.Addr, err error) {
+	buffer := buf.New()
+	_, err = buffer.ReadFrom(v.Reader)
+	if err != nil {
+		buffer.Release()
+		return 0, nil, err
+	}
+	vaddr, payload, err := DecodeUDPPacket(v.User, buffer)
+	if err != nil {
+		buffer.Release()
+		return 0, nil, err
+	}
+	n = copy(p, payload.Bytes())
+	payload.Release()
+	return n, &gonet.UDPAddr{IP: vaddr.Address.IP(), Port: int(vaddr.Port)}, nil
+}
+
 type UDPWriter struct {
 	Writer  io.Writer
 	Request *protocol.RequestHeader
@@ -268,3 +286,18 @@ func (w *UDPWriter) Write(payload []byte) (int, error) {
 	packet.Release()
 	return len(payload), err
 }
+
+func (w *UDPWriter) WriteTo(payload []byte, addr gonet.Addr) (n int, err error) {
+	request := *w.Request
+	udpAddr := addr.(*gonet.UDPAddr)
+	request.Command = protocol.RequestCommandUDP
+	request.Address = net.IPAddress(udpAddr.IP)
+	request.Port = net.Port(udpAddr.Port)
+	packet, err := EncodeUDPPacket(&request, payload)
+	if err != nil {
+		return 0, err
+	}
+	_, err = w.Writer.Write(packet.Bytes())
+	packet.Release()
+	return len(payload), err
+}

transport/internet/connection.go

@@ -3,13 +3,33 @@ package internet
 import (
 	"net"
 
-	"github.com/v2fly/v2ray-core/v5/features/stats"
+	"github.com/v2fly/v2ray-core/v4/common"
+	"github.com/v2fly/v2ray-core/v4/features/stats"
 )
 
 type Connection interface {
 	net.Conn
 }
 
+type AbstractPacketConnReader interface {
+	ReadFrom(p []byte) (n int, addr net.Addr, err error)
+}
+
+type AbstractPacketConnWriter interface {
+	WriteTo(p []byte, addr net.Addr) (n int, err error)
+}
+
+type AbstractPacketConn interface {
+	AbstractPacketConnReader
+	AbstractPacketConnWriter
+	common.Closable
+}
+
+type PacketConn interface {
+	AbstractPacketConn
+	net.PacketConn
+}
+
 type StatCouterConnection struct {
 	Connection
 	ReadCounter  stats.Counter

transport/internet/udp/copy.go

@@ -0,0 +1,47 @@
+package udp
+
+import (
+	gonet "net"
+
+	"github.com/v2fly/v2ray-core/v4/common/signal"
+	"github.com/v2fly/v2ray-core/v4/transport/internet"
+)
+
+type dataHandler func(content []byte, address gonet.Addr)
+
+type copyHandler struct {
+	onData []dataHandler
+}
+
+type CopyOption func(*copyHandler)
+
+func CopyPacketConn(dst internet.AbstractPacketConnWriter, src internet.AbstractPacketConnReader, options ...CopyOption) error {
+	var handler copyHandler
+	for _, option := range options {
+		option(&handler)
+	}
+	var buffer [2048]byte
+	for {
+		n, addr, err := src.ReadFrom(buffer[:])
+		if err != nil {
+			return err
+		}
+
+		for _, handler := range handler.onData {
+			handler(buffer[:n], addr)
+		}
+
+		n, err = dst.WriteTo(buffer[:n], addr)
+		if err != nil {
+			return err
+		}
+	}
+}
+
+func UpdateActivity(timer signal.ActivityUpdater) CopyOption {
+	return func(handler *copyHandler) {
+		handler.onData = append(handler.onData, func(content []byte, address gonet.Addr) {
+			timer.Update()
+		})
+	}
+}