package wireguard import ( "context" "net" "net/netip" "sync" "github.com/sagernet/sing/common" "github.com/sagernet/sing/common/bufio" E "github.com/sagernet/sing/common/exceptions" M "github.com/sagernet/sing/common/metadata" N "github.com/sagernet/sing/common/network" "github.com/sagernet/wireguard-go/conn" ) var _ conn.Bind = (*ClientBind)(nil) type ClientBind struct { ctx context.Context errorHandler E.Handler dialer N.Dialer reservedForEndpoint map[M.Socksaddr][3]uint8 connAccess sync.Mutex conn *wireConn done chan struct{} isConnect bool connectAddr M.Socksaddr reserved [3]uint8 } func NewClientBind(ctx context.Context, errorHandler E.Handler, dialer N.Dialer, isConnect bool, connectAddr M.Socksaddr, reserved [3]uint8) *ClientBind { return &ClientBind{ ctx: ctx, errorHandler: errorHandler, dialer: dialer, reservedForEndpoint: make(map[M.Socksaddr][3]uint8), isConnect: isConnect, connectAddr: connectAddr, reserved: reserved, } } func (c *ClientBind) SetReservedForEndpoint(destination M.Socksaddr, reserved [3]byte) { c.reservedForEndpoint[destination] = reserved } func (c *ClientBind) connect() (*wireConn, error) { serverConn := c.conn if serverConn != nil { select { case <-serverConn.done: serverConn = nil default: return serverConn, nil } } c.connAccess.Lock() defer c.connAccess.Unlock() serverConn = c.conn if serverConn != nil { select { case <-serverConn.done: serverConn = nil default: return serverConn, nil } } if c.isConnect { udpConn, err := c.dialer.DialContext(c.ctx, N.NetworkUDP, c.connectAddr) if err != nil { return nil, err } c.conn = &wireConn{ PacketConn: &bufio.UnbindPacketConn{ ExtendedConn: bufio.NewExtendedConn(udpConn), Addr: c.connectAddr, }, done: make(chan struct{}), } } else { udpConn, err := c.dialer.ListenPacket(c.ctx, M.Socksaddr{Addr: netip.IPv4Unspecified()}) if err != nil { return nil, err } c.conn = &wireConn{ PacketConn: bufio.NewPacketConn(udpConn), done: make(chan struct{}), } } return c.conn, nil } func (c *ClientBind) Open(port uint16) (fns []conn.ReceiveFunc, actualPort uint16, err error) { select { case <-c.done: err = net.ErrClosed return default: } return []conn.ReceiveFunc{c.receive}, 0, nil } func (c *ClientBind) receive(packets [][]byte, sizes []int, eps []conn.Endpoint) (count int, err error) { udpConn, err := c.connect() if err != nil { select { case <-c.done: return default: } c.errorHandler.NewError(context.Background(), E.Cause(err, "connect to server")) err = nil return } n, addr, err := udpConn.ReadFrom(packets[0]) if err != nil { udpConn.Close() select { case <-c.done: default: c.errorHandler.NewError(context.Background(), E.Cause(err, "read packet")) err = nil } return } sizes[0] = n if n > 3 { b := packets[0] b[1] = 0 b[2] = 0 b[3] = 0 } eps[0] = Endpoint(M.SocksaddrFromNet(addr)) count = 1 return } func (c *ClientBind) Reset() { common.Close(common.PtrOrNil(c.conn)) } func (c *ClientBind) Close() error { common.Close(common.PtrOrNil(c.conn)) if c.done == nil { c.done = make(chan struct{}) return nil } select { case <-c.done: return net.ErrClosed default: close(c.done) } return nil } func (c *ClientBind) SetMark(mark uint32) error { return nil } func (c *ClientBind) Send(bufs [][]byte, ep conn.Endpoint) error { udpConn, err := c.connect() if err != nil { return err } destination := M.Socksaddr(ep.(Endpoint)) for _, b := range bufs { if len(b) > 3 { reserved, loaded := c.reservedForEndpoint[destination] if !loaded { reserved = c.reserved } b[1] = reserved[0] b[2] = reserved[1] b[3] = reserved[2] } _, err = udpConn.WriteTo(b, destination) if err != nil { udpConn.Close() return err } } return nil } func (c *ClientBind) ParseEndpoint(s string) (conn.Endpoint, error) { return Endpoint(M.ParseSocksaddr(s)), nil } func (c *ClientBind) BatchSize() int { return 1 } type wireConn struct { net.PacketConn access sync.Mutex done chan struct{} } func (w *wireConn) Close() error { w.access.Lock() defer w.access.Unlock() select { case <-w.done: return net.ErrClosed default: } w.PacketConn.Close() close(w.done) return nil }