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 }