package carrier import ( "fmt" "io" "net" "net/http" "net/http/httputil" "github.com/cloudflare/cloudflared/cmd/cloudflared/token" "github.com/cloudflare/cloudflared/socks" cfwebsocket "github.com/cloudflare/cloudflared/websocket" "github.com/gorilla/websocket" "github.com/rs/zerolog" ) // 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 } type wsdialer struct { conn *cfwebsocket.GorillaConn } func (d *wsdialer) Dial(address string) (io.ReadWriteCloser, *socks.AddrSpec, error) { local, ok := d.conn.LocalAddr().(*net.TCPAddr) if !ok { return nil, nil, fmt.Errorf("not a tcp connection") } addr := socks.AddrSpec{IP: local.IP, Port: local.Port} return d.conn, &addr, nil } // NewWSConnection returns a new connection object func NewWSConnection(log *zerolog.Logger, isSocks bool) Connection { return &Websocket{ log: log, isSocks: isSocks, } } // 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() if ws.isSocks { dialer := &wsdialer{conn: wsConn} requestHandler := socks.NewRequestHandler(dialer) socksServer := socks.NewConnectionHandler(requestHandler) _ = socksServer.Serve(conn) } else { cfwebsocket.Stream(wsConn, conn) } return nil } // StartServer creates a Websocket server to listen for connections. // This is used on the origin (tunnel) side to take data from the muxer and send it to the origin func (ws *Websocket) StartServer(listener net.Listener, remote string, shutdownC <-chan struct{}) error { return cfwebsocket.StartProxyServer(ws.log, listener, remote, shutdownC, cfwebsocket.DefaultStreamHandler) } // 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 dump, err := httputil.DumpRequest(req, false) log.Debug().Msgf("Websocket request: %s", string(dump)) wsConn, resp, err := cfwebsocket.ClientConnect(req, nil) defer closeRespBody(resp) if err != nil && IsAccessResponse(resp) { wsConn, err = createAccessAuthenticatedStream(options, log) if err != nil { return nil, err } } else if err != nil { return nil, err } return &cfwebsocket.GorillaConn{Conn: wsConn}, nil } // 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 originReq, err := http.NewRequest(http.MethodGet, options.OriginURL, nil) if err != nil { return nil, err } if err := token.RemoveTokenIfExists(originReq.URL); 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 := cfwebsocket.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 }