Merge pull request #219 from xiaokangwang/substituteDialer

Solve #218: Supporting substitute of the default Dialer.

transport/internet/dialer.go

@@ -56,11 +56,15 @@ func Dial(src v2net.Address, dest v2net.Destination, settings *StreamSettings) (
 }
 
 func DialToDest(src v2net.Address, dest v2net.Destination) (net.Conn, error) {
+
+	if isDefaultDialerSubstituted() {
+		dialer := v2AlternativeDialer
+		return (*dialer).Dial(dest.Network().String(), dest.NetAddr())
+	} else {
 		dialer := &net.Dialer{
 			Timeout:   time.Second * 60,
 			DualStack: true,
 		}
-
 		if src != nil && src != v2net.AnyIP {
 			var addr net.Addr
 			if dest.IsTCP() {
@@ -76,6 +80,6 @@ func DialToDest(src v2net.Address, dest v2net.Destination) (net.Conn, error) {
 			}
 			dialer.LocalAddr = addr
 		}
-
 		return dialer.Dial(dest.Network().String(), dest.NetAddr())
+	}
 }

transport/internet/dialerSubstitute.go

@@ -0,0 +1,18 @@
+package internet
+
+import "net"
+
+var v2AlternativeDialer *V2AlternativeDialerT
+
+type V2AlternativeDialerT interface {
+	Dial(nw string, ad string) (net.Conn, error)
+}
+
+func SubstituteDialer(substituteWith V2AlternativeDialerT) error {
+	v2AlternativeDialer = &substituteWith
+	return nil
+}
+
+func isDefaultDialerSubstituted() bool {
+	return (v2AlternativeDialer != nil)
+}