Basic implementation of socks udp listener.

proxy/socks/udp.go

@@ -0,0 +1,52 @@
+package socks
+
+import (
+	"net"
+
+	"github.com/v2ray/v2ray-core/common/log"
+	v2net "github.com/v2ray/v2ray-core/common/net"
+	"github.com/v2ray/v2ray-core/proxy/socks/protocol"
+)
+
+const (
+	bufferSize = 2 * 1024
+)
+
+func (server *SocksServer) ListenUDP(port uint16) error {
+	addr := &net.UDPAddr{
+		IP:   net.IP{0, 0, 0, 0},
+		Port: int(port),
+		Zone: "",
+	}
+	conn, err := net.ListenUDP("udp", addr)
+	if err != nil {
+		log.Error("Socks failed to listen UDP on port %d: %v", port, err)
+		return err
+	}
+
+	go server.AcceptPackets(conn)
+	return nil
+}
+
+func (server *SocksServer) AcceptPackets(conn *net.UDPConn) error {
+	for {
+		buffer := make([]byte, 0, bufferSize)
+		nBytes, _, err := conn.ReadFromUDP(buffer)
+		if err != nil {
+			log.Error("Socks failed to read UDP packets: %v", err)
+			return err
+		}
+		request, err := protocol.ReadUDPRequest(buffer[:nBytes])
+		if err != nil {
+			log.Error("Socks failed to parse UDP request: %v", err)
+			return err
+		}
+		if request.Fragment != 0 {
+			// TODO handle fragments
+			continue
+		}
+
+		udpPacket := v2net.NewUDPPacket(request.Destination(), request.Data)
+		server.vPoint.DispatchToOutbound(udpPacket)
+	}
+}