From 1457f83530a3d386f49c29c1bb0e846e6350e11a Mon Sep 17 00:00:00 2001
From: wwqgtxx <wwqgtxx@gmail.com>
Date: Tue, 18 Jun 2024 13:12:44 +0800
Subject: [PATCH] fix: dns server using direct outbound lookback resolve
 problem

---
 adapter/outbound/direct.go | 4 ++++
 component/dialer/dialer.go | 6 +++---
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/adapter/outbound/direct.go b/adapter/outbound/direct.go
index c904d3b6..7114045d 100644
--- a/adapter/outbound/direct.go
+++ b/adapter/outbound/direct.go
@@ -64,6 +64,10 @@ func (d *Direct) ListenPacketContext(ctx context.Context, metadata *C.Metadata,
 	return d.loopBack.NewPacketConn(newPacketConn(pc, d)), nil
 }
 
+func (d *Direct) IsL3Protocol(metadata *C.Metadata) bool {
+	return true // tell DNSDialer don't send domain to DialContext, avoid lookback to DefaultResolver
+}
+
 func NewDirectWithOption(option DirectOption) *Direct {
 	return &Direct{
 		Base: &Base{
diff --git a/component/dialer/dialer.go b/component/dialer/dialer.go
index c21e638e..54a1aa6a 100644
--- a/component/dialer/dialer.go
+++ b/component/dialer/dialer.go
@@ -378,12 +378,12 @@ func (d Dialer) DialContext(ctx context.Context, network, address string) (net.C
 }
 
 func (d Dialer) ListenPacket(ctx context.Context, network, address string, rAddrPort netip.AddrPort) (net.PacketConn, error) {
-	opt := WithOption(d.Opt)
+	opt := d.Opt // make a copy
 	if rAddrPort.Addr().Unmap().IsLoopback() {
 		// avoid "The requested address is not valid in its context."
-		opt = WithInterface("")
+		WithInterface("")(&opt)
 	}
-	return ListenPacket(ctx, ParseNetwork(network, rAddrPort.Addr()), address, rAddrPort, opt)
+	return ListenPacket(ctx, ParseNetwork(network, rAddrPort.Addr()), address, rAddrPort, WithOption(opt))
 }
 
 func NewDialer(options ...Option) Dialer {