chore: rebuild udp dns resolve

The DNS resolution of the overall UDP part has been delayed to the connection initiation stage. During the rule matching process, it will only be triggered when the IP rule without no-resolve is matched.

For direct and wireguard outbound, the same logic as the TCP part will be followed, that is, when direct-nameserver (or DNS configured by wireguard) exists, the result of the matching process will be discarded and the domain name will be re-resolved. This re-resolution logic is only effective for fakeip.

For reject and DNS outbound, no resolution is required.

For other outbound, resolution will still be performed when the connection is initiated, and the domain name will not be sent directly to the remote server at present.

component/sniffer/quic_sniffer.go

@@ -76,9 +76,9 @@ func (sniffer *QuicSniffer) SniffData(b []byte) (string, error) {
 
 func (sniffer *QuicSniffer) WrapperSender(packetSender constant.PacketSender, override bool) constant.PacketSender {
 	return &quicPacketSender{
-		sender:   packetSender,
-		chClose:  make(chan struct{}),
-		override: override,
+		PacketSender: packetSender,
+		chClose:      make(chan struct{}),
+		override:     override,
 	}
 }
 
@@ -91,7 +91,7 @@ type quicPacketSender struct {
 	result   string
 	override bool
 
-	sender constant.PacketSender
+	constant.PacketSender
 
 	chClose chan struct{}
 	closed  bool
@@ -100,7 +100,7 @@ type quicPacketSender struct {
 // Send will send PacketAdapter nonblocking
 // the implement must call UDPPacket.Drop() inside Send
 func (q *quicPacketSender) Send(current constant.PacketAdapter) {
-	defer q.sender.Send(current)
+	defer q.PacketSender.Send(current)
 
 	q.lock.RLock()
 	if q.closed {
@@ -116,29 +116,24 @@ func (q *quicPacketSender) Send(current constant.PacketAdapter) {
 	}
 }
 
-// Process is a blocking loop to send PacketAdapter to PacketConn and update the WriteBackProxy
-func (q *quicPacketSender) Process(conn constant.PacketConn, proxy constant.WriteBackProxy) {
-	q.sender.Process(conn, proxy)
-}
-
-// ResolveUDP wait sniffer recv all fragments and update the domain
-func (q *quicPacketSender) ResolveUDP(data *constant.Metadata) error {
+// DoSniff wait sniffer recv all fragments and update the domain
+func (q *quicPacketSender) DoSniff(metadata *constant.Metadata) error {
 	select {
 	case <-q.chClose:
 		q.lock.RLock()
-		replaceDomain(data, q.result, q.override)
+		replaceDomain(metadata, q.result, q.override)
 		q.lock.RUnlock()
 		break
 	case <-time.After(quicWaitConn):
 		q.close()
 	}
 
-	return q.sender.ResolveUDP(data)
+	return q.PacketSender.DoSniff(metadata)
 }
 
 // Close stop the Process loop
 func (q *quicPacketSender) Close() {
-	q.sender.Close()
+	q.PacketSender.Close()
 	q.close()
 }
 

component/sniffer/sniff_test.go

@@ -12,7 +12,7 @@ import (
 )
 
 type fakeSender struct {
-	resultCh chan *constant.Metadata
+	constant.PacketSender
 }
 
 var _ constant.PacketSender = (*fakeSender)(nil)
@@ -22,18 +22,7 @@ func (e *fakeSender) Send(packet constant.PacketAdapter) {
 	packet.Drop()
 }
 
-func (e *fakeSender) Process(constant.PacketConn, constant.WriteBackProxy) {
-	panic("not implemented")
-}
-
-func (e *fakeSender) ResolveUDP(metadata *constant.Metadata) error {
-	e.resultCh <- metadata
-	return nil
-}
-
-func (e *fakeSender) Close() {
-	panic("not implemented")
-}
+func (e *fakeSender) DoSniff(metadata *constant.Metadata) error { return nil }
 
 type fakeUDPPacket struct {
 	data  []byte
@@ -85,16 +74,17 @@ func testQuicSniffer(data []string, async bool) (string, error) {
 	}
 
 	resultCh := make(chan *constant.Metadata, 1)
-	emptySender := &fakeSender{resultCh: resultCh}
+	emptySender := &fakeSender{}
 
 	sender := q.WrapperSender(emptySender, true)
 
 	go func() {
 		meta := constant.Metadata{}
-		err = sender.ResolveUDP(&meta)
+		err := sender.DoSniff(&meta)
 		if err != nil {
 			panic(err)
 		}
+		resultCh <- &meta
 	}()
 
 	for _, d := range data {