package carrier import ( "io" "net/http" "net/http/httputil" "net/url" "github.com/gorilla/websocket" "github.com/rs/zerolog" "github.com/cloudflare/cloudflared/token" cfwebsocket "github.com/cloudflare/cloudflared/websocket" ) // Websocket is used to carry data via WS binary frames over the tunnel from client to the origin // This implements the functions for glider proxy (sock5) and the carrier interface type Websocket struct { log *zerolog.Logger isSocks bool } // NewWSConnection returns a new connection object func NewWSConnection(log *zerolog.Logger) Connection { return &Websocket{ log: log, } } // ServeStream will create a Websocket client stream connection to the edge // it blocks and writes the raw data from conn over the tunnel func (ws *Websocket) ServeStream(options *StartOptions, conn io.ReadWriter) error { wsConn, err := createWebsocketStream(options, ws.log) if err != nil { ws.log.Err(err).Str(LogFieldOriginURL, options.OriginURL).Msg("failed to connect to origin") return err } defer wsConn.Close() cfwebsocket.Stream(wsConn, conn, ws.log) return nil } // createWebsocketStream will create a WebSocket connection to stream data over // It also handles redirects from Access and will present that flow if // the token is not present on the request func createWebsocketStream(options *StartOptions, log *zerolog.Logger) (*cfwebsocket.GorillaConn, error) { req, err := http.NewRequest(http.MethodGet, options.OriginURL, nil) if err != nil { return nil, err } req.Header = options.Headers if options.Host != "" { req.Host = options.Host } dump, err := httputil.DumpRequest(req, false) log.Debug().Msgf("Websocket request: %s", string(dump)) dialer := &websocket.Dialer{ TLSClientConfig: options.TLSClientConfig, Proxy: http.ProxyFromEnvironment, } wsConn, resp, err := clientConnect(req, dialer) defer closeRespBody(resp) if err != nil && IsAccessResponse(resp) { // Only get Access app info if we know the origin is protected by Access originReq, err := http.NewRequest(http.MethodGet, options.OriginURL, nil) if err != nil { return nil, err } appInfo, err := token.GetAppInfo(originReq.URL) if err != nil { return nil, err } options.AppInfo = appInfo wsConn, err = createAccessAuthenticatedStream(options, log) if err != nil { return nil, err } } else if err != nil { return nil, err } return &cfwebsocket.GorillaConn{Conn: wsConn}, nil } var stripWebsocketHeaders = []string{ "Upgrade", "Connection", "Sec-Websocket-Key", "Sec-Websocket-Version", "Sec-Websocket-Extensions", } // the gorilla websocket library sets its own Upgrade, Connection, Sec-WebSocket-Key, // Sec-WebSocket-Version and Sec-Websocket-Extensions headers. // https://github.com/gorilla/websocket/blob/master/client.go#L189-L194. func websocketHeaders(req *http.Request) http.Header { wsHeaders := make(http.Header) for key, val := range req.Header { wsHeaders[key] = val } // Assume the header keys are in canonical format. for _, header := range stripWebsocketHeaders { wsHeaders.Del(header) } wsHeaders.Set("Host", req.Host) // See TUN-1097 return wsHeaders } // clientConnect creates a WebSocket client connection for provided request. Caller is responsible for closing // the connection. The response body may not contain the entire response and does // not need to be closed by the application. func clientConnect(req *http.Request, dialler *websocket.Dialer) (*websocket.Conn, *http.Response, error) { req.URL.Scheme = changeRequestScheme(req.URL) wsHeaders := websocketHeaders(req) if dialler == nil { dialler = &websocket.Dialer{ Proxy: http.ProxyFromEnvironment, } } conn, response, err := dialler.Dial(req.URL.String(), wsHeaders) if err != nil { return nil, response, err } return conn, response, nil } // changeRequestScheme is needed as the gorilla websocket library requires the ws scheme. // (even though it changes it back to http/https, but ¯\_(ツ)_/¯.) func changeRequestScheme(reqURL *url.URL) string { switch reqURL.Scheme { case "https": return "wss" case "http": return "ws" case "": return "ws" default: return reqURL.Scheme } } // createAccessAuthenticatedStream will try load a token from storage and make // a connection with the token set on the request. If it still get redirect, // this probably means the token in storage is invalid (expired/revoked). If that // happens it deletes the token and runs the connection again, so the user can // login again and generate a new one. func createAccessAuthenticatedStream(options *StartOptions, log *zerolog.Logger) (*websocket.Conn, error) { wsConn, resp, err := createAccessWebSocketStream(options, log) defer closeRespBody(resp) if err == nil { return wsConn, nil } if !IsAccessResponse(resp) { return nil, err } // Access Token is invalid for some reason. Go through regen flow if err := token.RemoveTokenIfExists(options.AppInfo); err != nil { return nil, err } wsConn, resp, err = createAccessWebSocketStream(options, log) defer closeRespBody(resp) if err != nil { return nil, err } return wsConn, nil } // createAccessWebSocketStream builds an Access request and makes a connection func createAccessWebSocketStream(options *StartOptions, log *zerolog.Logger) (*websocket.Conn, *http.Response, error) { req, err := BuildAccessRequest(options, log) if err != nil { return nil, nil, err } dump, err := httputil.DumpRequest(req, false) log.Debug().Msgf("Access Websocket request: %s", string(dump)) conn, resp, err := clientConnect(req, nil) if resp != nil { r, err := httputil.DumpResponse(resp, true) if r != nil { log.Debug().Msgf("Websocket response: %q", r) } else if err != nil { log.Debug().Msgf("Websocket response error: %v", err) } } return conn, resp, err }