Fix missing loopback detect

2023-12-20 10:52:11 +08:00
parent 216a0380fe
commit 017372db25
2 changed files with 167 additions and 1 deletions
--- a/outbound/direct_loopback_detect.go
+++ b/outbound/direct_loopback_detect.go
@@ -0,0 +1,153 @@
+package outbound
+
+import (
+	"net"
+	"net/netip"
+	"sync"
+
+	M "github.com/sagernet/sing/common/metadata"
+)
+
+type loopBackDetector struct {
+	connAccess       sync.RWMutex
+	packetConnAccess sync.RWMutex
+	connMap          map[netip.AddrPort]bool
+	packetConnMap    map[netip.AddrPort]bool
+}
+
+func newLoopBackDetector() *loopBackDetector {
+	return &loopBackDetector{
+		connMap:       make(map[netip.AddrPort]bool),
+		packetConnMap: make(map[netip.AddrPort]bool),
+	}
+}
+
+func (l *loopBackDetector) NewConn(conn net.Conn) net.Conn {
+	connAddr := M.AddrPortFromNet(conn.LocalAddr())
+	if !connAddr.IsValid() {
+		return conn
+	}
+	if udpConn, isUDPConn := conn.(abstractUDPConn); isUDPConn {
+		l.packetConnAccess.Lock()
+		l.packetConnMap[connAddr] = true
+		l.packetConnAccess.Unlock()
+		return &loopBackDetectUDPWrapper{abstractUDPConn: udpConn, detector: l, connAddr: connAddr}
+	} else {
+		l.connAccess.Lock()
+		l.connMap[connAddr] = true
+		l.connAccess.Unlock()
+		return &loopBackDetectWrapper{Conn: conn, detector: l, connAddr: connAddr}
+	}
+}
+
+func (l *loopBackDetector) NewPacketConn(conn net.PacketConn) net.PacketConn {
+	connAddr := M.AddrPortFromNet(conn.LocalAddr())
+	if !connAddr.IsValid() {
+		return conn
+	}
+	l.packetConnAccess.Lock()
+	l.packetConnMap[connAddr] = true
+	l.packetConnAccess.Unlock()
+	return &loopBackDetectPacketWrapper{PacketConn: conn, detector: l, connAddr: connAddr}
+}
+
+func (l *loopBackDetector) CheckConn(connAddr netip.AddrPort) bool {
+	l.connAccess.RLock()
+	defer l.connAccess.RUnlock()
+	return l.connMap[connAddr]
+}
+
+func (l *loopBackDetector) CheckPacketConn(connAddr netip.AddrPort) bool {
+	l.packetConnAccess.RLock()
+	defer l.packetConnAccess.RUnlock()
+	return l.packetConnMap[connAddr]
+}
+
+type loopBackDetectWrapper struct {
+	net.Conn
+	detector  *loopBackDetector
+	connAddr  netip.AddrPort
+	closeOnce sync.Once
+}
+
+func (w *loopBackDetectWrapper) Close() error {
+	w.closeOnce.Do(func() {
+		w.detector.connAccess.Lock()
+		delete(w.detector.connMap, w.connAddr)
+		w.detector.connAccess.Unlock()
+	})
+	return w.Conn.Close()
+}
+
+func (w *loopBackDetectWrapper) ReaderReplaceable() bool {
+	return true
+}
+
+func (w *loopBackDetectWrapper) WriterReplaceable() bool {
+	return true
+}
+
+func (w *loopBackDetectWrapper) Upstream() any {
+	return w.Conn
+}
+
+type loopBackDetectPacketWrapper struct {
+	net.PacketConn
+	detector  *loopBackDetector
+	connAddr  netip.AddrPort
+	closeOnce sync.Once
+}
+
+func (w *loopBackDetectPacketWrapper) Close() error {
+	w.closeOnce.Do(func() {
+		w.detector.packetConnAccess.Lock()
+		delete(w.detector.packetConnMap, w.connAddr)
+		w.detector.packetConnAccess.Unlock()
+	})
+	return w.PacketConn.Close()
+}
+
+func (w *loopBackDetectPacketWrapper) ReaderReplaceable() bool {
+	return true
+}
+
+func (w *loopBackDetectPacketWrapper) WriterReplaceable() bool {
+	return true
+}
+
+func (w *loopBackDetectPacketWrapper) Upstream() any {
+	return w.PacketConn
+}
+
+type abstractUDPConn interface {
+	net.Conn
+	net.PacketConn
+}
+
+type loopBackDetectUDPWrapper struct {
+	abstractUDPConn
+	detector  *loopBackDetector
+	connAddr  netip.AddrPort
+	closeOnce sync.Once
+}
+
+func (w *loopBackDetectUDPWrapper) Close() error {
+	w.closeOnce.Do(func() {
+		w.detector.packetConnAccess.Lock()
+		delete(w.detector.packetConnMap, w.connAddr)
+		w.detector.packetConnAccess.Unlock()
+	})
+	return w.abstractUDPConn.Close()
+}
+
+func (w *loopBackDetectUDPWrapper) ReaderReplaceable() bool {
+	return true
+}
+
+func (w *loopBackDetectUDPWrapper) WriterReplaceable() bool {
+	return true
+}
+
+func (w *loopBackDetectUDPWrapper) Upstream() any {
+	return w.abstractUDPConn
+}