增加协议屏蔽支持

go-gost/gfw/modifier/interface.go

@@ -0,0 +1,32 @@
+package modifier
+
+type Modifier interface {
+	// Name returns the name of the modifier.
+	Name() string
+	// New returns a new modifier instance.
+	New(args map[string]interface{}) (Instance, error)
+}
+
+type Instance interface{}
+
+type UDPModifierInstance interface {
+	Instance
+	// Process takes a UDP packet and returns a modified UDP packet.
+	Process(data []byte) ([]byte, error)
+}
+
+type ErrInvalidPacket struct {
+	Err error
+}
+
+func (e *ErrInvalidPacket) Error() string {
+	return "invalid packet: " + e.Err.Error()
+}
+
+type ErrInvalidArgs struct {
+	Err error
+}
+
+func (e *ErrInvalidArgs) Error() string {
+	return "invalid args: " + e.Err.Error()
+}