From 10376f5b4d9bb27561a9fb6860a43da263fc8d0a Mon Sep 17 00:00:00 2001
From: patterniha <71074308+patterniha@users.noreply.github.com>
Date: Sat, 26 Jul 2025 03:59:15 +0200
Subject: [PATCH] Freedom UDP: Fix some cone uses like STUN,... when address is
 domain (#4942)

https://github.com/XTLS/Xray-core/issues/2962#issuecomment-3120472154
---
 proxy/freedom/freedom.go | 24 +++++++++++++++++-------
 1 file changed, 17 insertions(+), 7 deletions(-)

diff --git a/proxy/freedom/freedom.go b/proxy/freedom/freedom.go
index 395c9641..1f9d5ae5 100644
--- a/proxy/freedom/freedom.go
+++ b/proxy/freedom/freedom.go
@@ -285,14 +285,18 @@ func NewPacketReader(conn net.Conn, UDPOverride net.Destination, DialDest net.De
 		counter = statConn.ReadCounter
 	}
 	if c, ok := iConn.(*internet.PacketConnWrapper); ok {
-		isAddrChanged := false
-		if UDPOverride.Address != nil || UDPOverride.Port != 0 || DialDest.Address.Family().IsDomain() {
-			isAddrChanged = true
+		isOverridden := false
+		if UDPOverride.Address != nil || UDPOverride.Port != 0 {
+			isOverridden = true
 		}
+		changedAddress, _, _ := net.SplitHostPort(conn.RemoteAddr().String())
+
 		return &PacketReader{
 			PacketConnWrapper: c,
 			Counter:           counter,
-			IsAddrChanged:     isAddrChanged,
+			IsOverridden:      isOverridden,
+			InitUnchangedAddr: DialDest.Address,
+			InitChangedAddr:   net.ParseAddress(changedAddress),
 		}
 	}
 	return &buf.PacketReader{Reader: conn}
@@ -301,7 +305,9 @@ func NewPacketReader(conn net.Conn, UDPOverride net.Destination, DialDest net.De
 type PacketReader struct {
 	*internet.PacketConnWrapper
 	stats.Counter
-	IsAddrChanged bool
+	IsOverridden      bool
+	InitUnchangedAddr net.Address
+	InitChangedAddr   net.Address
 }
 
 func (r *PacketReader) ReadMultiBuffer() (buf.MultiBuffer, error) {
@@ -315,9 +321,13 @@ func (r *PacketReader) ReadMultiBuffer() (buf.MultiBuffer, error) {
 	b.Resize(0, int32(n))
 	// if udp dest addr is changed, we are unable to get the correct src addr
 	// so we don't attach src info to udp packet, break cone behavior, assuming the dial dest is the expected scr addr
-	if !r.IsAddrChanged {
+	if !r.IsOverridden {
+		address := net.IPAddress(d.(*net.UDPAddr).IP)
+		if r.InitChangedAddr == address {
+			address = r.InitUnchangedAddr
+		}
 		b.UDP = &net.Destination{
-			Address: net.IPAddress(d.(*net.UDPAddr).IP),
+			Address: address,
 			Port:    net.Port(d.(*net.UDPAddr).Port),
 			Network: net.Network_UDP,
 		}