Fix interrupt_exist_connections

common/interrupt/conn.go

@@ -3,6 +3,7 @@ package interrupt
 import (
 	"net"
 
+	N "github.com/sagernet/sing/common/network"
 	"github.com/sagernet/sing/common/x/list"
 )
 
@@ -73,3 +74,32 @@ func (c *PacketConn) WriterReplaceable() bool {
 func (c *PacketConn) Upstream() any {
 	return c.PacketConn
 }
+
+type SingPacketConn struct {
+	N.PacketConn
+	group   *Group
+	element *list.Element[*groupConnItem]
+}
+
+/*func (c *SingPacketConn) MarkAsInternal() {
+	c.element.Value.internal = true
+}*/
+
+func (c *SingPacketConn) Close() error {
+	c.group.access.Lock()
+	defer c.group.access.Unlock()
+	c.group.connections.Remove(c.element)
+	return c.PacketConn.Close()
+}
+
+func (c *SingPacketConn) ReaderReplaceable() bool {
+	return true
+}
+
+func (c *SingPacketConn) WriterReplaceable() bool {
+	return true
+}
+
+func (c *SingPacketConn) Upstream() any {
+	return c.PacketConn
+}

common/interrupt/group.go

@@ -5,6 +5,7 @@ import (
 	"net"
 	"sync"
 
+	N "github.com/sagernet/sing/common/network"
 	"github.com/sagernet/sing/common/x/list"
 )
 
@@ -36,6 +37,13 @@ func (g *Group) NewPacketConn(conn net.PacketConn, isExternal bool) net.PacketCo
 	return &PacketConn{PacketConn: conn, group: g, element: item}
 }
 
+func (g *Group) NewSingPacketConn(conn N.PacketConn, isExternal bool) N.PacketConn {
+	g.access.Lock()
+	defer g.access.Unlock()
+	item := g.connections.PushBack(&groupConnItem{conn, isExternal})
+	return &SingPacketConn{PacketConn: conn, group: g, element: item}
+}
+
 func (g *Group) Interrupt(interruptExternalConnections bool) {
 	g.access.Lock()
 	defer g.access.Unlock()