Improve udp timeout

common/canceler/instance.go

@@ -0,0 +1,48 @@
+package canceler
+
+import (
+	"context"
+	"time"
+)
+
+type Instance struct {
+	ctx        context.Context
+	cancelFunc context.CancelFunc
+	timer      *time.Timer
+	timeout    time.Duration
+}
+
+func New(ctx context.Context, cancelFunc context.CancelFunc, timeout time.Duration) *Instance {
+	instance := &Instance{
+		ctx,
+		cancelFunc,
+		time.NewTimer(timeout),
+		timeout,
+	}
+	go instance.wait()
+	return instance
+}
+
+func (i *Instance) Update() bool {
+	if !i.timer.Stop() {
+		return false
+	}
+	if !i.timer.Reset(i.timeout) {
+		return false
+	}
+	return true
+}
+
+func (i *Instance) wait() {
+	select {
+	case <-i.timer.C:
+	case <-i.ctx.Done():
+	}
+	i.Close()
+}
+
+func (i *Instance) Close() error {
+	i.timer.Stop()
+	i.cancelFunc()
+	return nil
+}

common/canceler/packet.go

@@ -0,0 +1,41 @@
+package canceler
+
+import (
+	"context"
+	"time"
+
+	"github.com/sagernet/sing/common/buf"
+	M "github.com/sagernet/sing/common/metadata"
+	N "github.com/sagernet/sing/common/network"
+)
+
+type PacketConn struct {
+	N.PacketConn
+	instance *Instance
+}
+
+func NewPacketConn(ctx context.Context, conn N.PacketConn, timeout time.Duration) (context.Context, N.PacketConn) {
+	ctx, cancel := context.WithCancel(ctx)
+	instance := New(ctx, cancel, timeout)
+	return ctx, &PacketConn{conn, instance}
+}
+
+func (c *PacketConn) ReadPacket(buffer *buf.Buffer) (destination M.Socksaddr, err error) {
+	destination, err = c.PacketConn.ReadPacket(buffer)
+	if err == nil {
+		c.instance.Update()
+	}
+	return
+}
+
+func (c *PacketConn) WritePacket(buffer *buf.Buffer, destination M.Socksaddr) error {
+	err := c.PacketConn.WritePacket(buffer, destination)
+	if err == nil {
+		c.instance.Update()
+	}
+	return err
+}
+
+func (c *PacketConn) Upstream() any {
+	return c.PacketConn
+}

common/dialer/default.go

@@ -103,7 +103,7 @@ func NewDefault(router adapter.Router, options option.DialerOptions) *DefaultDia
 	if options.ConnectTimeout != 0 {
 		dialer.Timeout = time.Duration(options.ConnectTimeout)
 	} else {
-		dialer.Timeout = C.DefaultTCPTimeout
+		dialer.Timeout = C.TCPTimeout
 	}
 	if options.TCPFastOpen {
 		warnTFOOnUnsupportedPlatform.Check()
@@ -118,7 +118,7 @@ func (d *DefaultDialer) DialContext(ctx context.Context, network string, address
 	}
 	if tcpConn, isTCP := common.Cast[*net.TCPConn](conn); isTCP {
 		tcpConn.SetKeepAlive(true)
-		tcpConn.SetKeepAlivePeriod(C.DefaultTCPKeepAlivePeriod)
+		tcpConn.SetKeepAlivePeriod(C.TCPKeepAlivePeriod)
 	}
 	return conn, nil
 }

common/dialer/tls.go

@@ -129,7 +129,7 @@ func (d *TLSDialer) DialContext(ctx context.Context, network string, destination
 		return nil, err
 	}
 	tlsConn := tls.Client(conn, d.config)
-	ctx, cancel := context.WithTimeout(ctx, C.DefaultTCPTimeout)
+	ctx, cancel := context.WithTimeout(ctx, C.TCPTimeout)
 	defer cancel()
 	err = tlsConn.HandshakeContext(ctx)
 	return tlsConn, err