package dialer import ( "context" "github.com/sagernet/tfo-go" "io" "net" "time" ) type tfoConn struct { net.Conn closed bool dialed chan bool cancel context.CancelFunc ctx context.Context dialFn func(ctx context.Context, earlyData []byte) (net.Conn, error) } func (c *tfoConn) Dial(earlyData []byte) (err error) { c.Conn, err = c.dialFn(c.ctx, earlyData) if err != nil { return } c.dialed <- true return err } func (c *tfoConn) Read(b []byte) (n int, err error) { if c.closed { return 0, io.ErrClosedPipe } if c.Conn == nil { select { case <-c.ctx.Done(): return 0, io.ErrUnexpectedEOF case <-c.dialed: } } return c.Conn.Read(b) } func (c *tfoConn) Write(b []byte) (n int, err error) { if c.closed { return 0, io.ErrClosedPipe } if c.Conn == nil { if err := c.Dial(b); err != nil { return 0, err } return len(b), nil } return c.Conn.Write(b) } func (c *tfoConn) Close() error { c.closed = true c.cancel() if c.Conn == nil { return nil } return c.Conn.Close() } func (c *tfoConn) LocalAddr() net.Addr { if c.Conn == nil { return nil } return c.Conn.LocalAddr() } func (c *tfoConn) RemoteAddr() net.Addr { if c.Conn == nil { return nil } return c.Conn.RemoteAddr() } func (c *tfoConn) SetDeadline(t time.Time) error { if err := c.SetReadDeadline(t); err != nil { return err } return c.SetWriteDeadline(t) } func (c *tfoConn) SetReadDeadline(t time.Time) error { if c.Conn == nil { return nil } return c.Conn.SetReadDeadline(t) } func (c *tfoConn) SetWriteDeadline(t time.Time) error { if c.Conn == nil { return nil } return c.Conn.SetWriteDeadline(t) } func (c *tfoConn) Upstream() any { if c.Conn == nil { // ensure return a nil interface not an interface with nil value return nil } return c.Conn } func dialTFO(ctx context.Context, netDialer net.Dialer, network, address string) (net.Conn, error) { ctx, cancel := context.WithCancel(ctx) dialer := tfo.Dialer{Dialer: netDialer, DisableTFO: false} return &tfoConn{ dialed: make(chan bool, 1), cancel: cancel, ctx: ctx, dialFn: func(ctx context.Context, earlyData []byte) (net.Conn, error) { return dialer.DialContext(ctx, network, address, earlyData) }, }, nil }