| package client // import "github.com/docker/docker/client" |
| |
| import ( |
| "bufio" |
| "context" |
| "crypto/tls" |
| "fmt" |
| "net" |
| "net/http" |
| "net/http/httputil" |
| "net/url" |
| "time" |
| |
| "github.com/docker/docker/api/types" |
| "github.com/docker/go-connections/sockets" |
| "github.com/pkg/errors" |
| ) |
| |
| // postHijacked sends a POST request and hijacks the connection. |
| func (cli *Client) postHijacked(ctx context.Context, path string, query url.Values, body interface{}, headers map[string][]string) (types.HijackedResponse, error) { |
| bodyEncoded, err := encodeData(body) |
| if err != nil { |
| return types.HijackedResponse{}, err |
| } |
| |
| apiPath := cli.getAPIPath(ctx, path, query) |
| req, err := http.NewRequest(http.MethodPost, apiPath, bodyEncoded) |
| if err != nil { |
| return types.HijackedResponse{}, err |
| } |
| req = cli.addHeaders(req, headers) |
| |
| conn, err := cli.setupHijackConn(ctx, req, "tcp") |
| if err != nil { |
| return types.HijackedResponse{}, err |
| } |
| |
| return types.HijackedResponse{Conn: conn, Reader: bufio.NewReader(conn)}, err |
| } |
| |
| // DialHijack returns a hijacked connection with negotiated protocol proto. |
| func (cli *Client) DialHijack(ctx context.Context, url, proto string, meta map[string][]string) (net.Conn, error) { |
| req, err := http.NewRequest(http.MethodPost, url, nil) |
| if err != nil { |
| return nil, err |
| } |
| req = cli.addHeaders(req, meta) |
| |
| return cli.setupHijackConn(ctx, req, proto) |
| } |
| |
| // fallbackDial is used when WithDialer() was not called. |
| // See cli.Dialer(). |
| func fallbackDial(proto, addr string, tlsConfig *tls.Config) (net.Conn, error) { |
| if tlsConfig != nil && proto != "unix" && proto != "npipe" { |
| return tls.Dial(proto, addr, tlsConfig) |
| } |
| if proto == "npipe" { |
| return sockets.DialPipe(addr, 32*time.Second) |
| } |
| return net.Dial(proto, addr) |
| } |
| |
| func (cli *Client) setupHijackConn(ctx context.Context, req *http.Request, proto string) (net.Conn, error) { |
| req.Host = cli.addr |
| req.Header.Set("Connection", "Upgrade") |
| req.Header.Set("Upgrade", proto) |
| |
| dialer := cli.Dialer() |
| conn, err := dialer(ctx) |
| if err != nil { |
| return nil, errors.Wrap(err, "cannot connect to the Docker daemon. Is 'docker daemon' running on this host?") |
| } |
| |
| // When we set up a TCP connection for hijack, there could be long periods |
| // of inactivity (a long running command with no output) that in certain |
| // network setups may cause ECONNTIMEOUT, leaving the client in an unknown |
| // state. Setting TCP KeepAlive on the socket connection will prohibit |
| // ECONNTIMEOUT unless the socket connection truly is broken |
| if tcpConn, ok := conn.(*net.TCPConn); ok { |
| tcpConn.SetKeepAlive(true) |
| tcpConn.SetKeepAlivePeriod(30 * time.Second) |
| } |
| |
| clientconn := httputil.NewClientConn(conn, nil) |
| defer clientconn.Close() |
| |
| // Server hijacks the connection, error 'connection closed' expected |
| resp, err := clientconn.Do(req) |
| |
| //nolint:staticcheck // ignore SA1019 for connecting to old (pre go1.8) daemons |
| if err != httputil.ErrPersistEOF { |
| if err != nil { |
| return nil, err |
| } |
| if resp.StatusCode != http.StatusSwitchingProtocols { |
| resp.Body.Close() |
| return nil, fmt.Errorf("unable to upgrade to %s, received %d", proto, resp.StatusCode) |
| } |
| } |
| |
| c, br := clientconn.Hijack() |
| if br.Buffered() > 0 { |
| // If there is buffered content, wrap the connection. We return an |
| // object that implements CloseWrite iff the underlying connection |
| // implements it. |
| if _, ok := c.(types.CloseWriter); ok { |
| c = &hijackedConnCloseWriter{&hijackedConn{c, br}} |
| } else { |
| c = &hijackedConn{c, br} |
| } |
| } else { |
| br.Reset(nil) |
| } |
| |
| return c, nil |
| } |
| |
| // hijackedConn wraps a net.Conn and is returned by setupHijackConn in the case |
| // that a) there was already buffered data in the http layer when Hijack() was |
| // called, and b) the underlying net.Conn does *not* implement CloseWrite(). |
| // hijackedConn does not implement CloseWrite() either. |
| type hijackedConn struct { |
| net.Conn |
| r *bufio.Reader |
| } |
| |
| func (c *hijackedConn) Read(b []byte) (int, error) { |
| return c.r.Read(b) |
| } |
| |
| // hijackedConnCloseWriter is a hijackedConn which additionally implements |
| // CloseWrite(). It is returned by setupHijackConn in the case that a) there |
| // was already buffered data in the http layer when Hijack() was called, and b) |
| // the underlying net.Conn *does* implement CloseWrite(). |
| type hijackedConnCloseWriter struct { |
| *hijackedConn |
| } |
| |
| var _ types.CloseWriter = &hijackedConnCloseWriter{} |
| |
| func (c *hijackedConnCloseWriter) CloseWrite() error { |
| conn := c.Conn.(types.CloseWriter) |
| return conn.CloseWrite() |
| } |