cloudflare/cloudflared
Publicmirrored from https://github.com/cloudflare/cloudflaredAvailable
carrier/websocket.go
158lines · modecode
| 1 | package carrier |
| 2 | |
| 3 | import ( |
| 4 | "fmt" |
| 5 | "io" |
| 6 | "net" |
| 7 | "net/http" |
| 8 | "net/http/httputil" |
| 9 | |
| 10 | "github.com/cloudflare/cloudflared/cmd/cloudflared/token" |
| 11 | "github.com/cloudflare/cloudflared/socks" |
| 12 | cfwebsocket "github.com/cloudflare/cloudflared/websocket" |
| 13 | |
| 14 | "github.com/gorilla/websocket" |
| 15 | "github.com/rs/zerolog" |
| 16 | ) |
| 17 | |
| 18 | // Websocket is used to carry data via WS binary frames over the tunnel from client to the origin |
| 19 | // This implements the functions for glider proxy (sock5) and the carrier interface |
| 20 | type Websocket struct { |
| 21 | log *zerolog.Logger |
| 22 | isSocks bool |
| 23 | } |
| 24 | |
| 25 | type wsdialer struct { |
| 26 | conn *cfwebsocket.Conn |
| 27 | } |
| 28 | |
| 29 | func (d *wsdialer) Dial(address string) (io.ReadWriteCloser, *socks.AddrSpec, error) { |
| 30 | local, ok := d.conn.LocalAddr().(*net.TCPAddr) |
| 31 | if !ok { |
| 32 | return nil, nil, fmt.Errorf("not a tcp connection") |
| 33 | } |
| 34 | |
| 35 | addr := socks.AddrSpec{IP: local.IP, Port: local.Port} |
| 36 | return d.conn, &addr, nil |
| 37 | } |
| 38 | |
| 39 | // NewWSConnection returns a new connection object |
| 40 | func NewWSConnection(log *zerolog.Logger, isSocks bool) Connection { |
| 41 | return &Websocket{ |
| 42 | log: log, |
| 43 | isSocks: isSocks, |
| 44 | } |
| 45 | } |
| 46 | |
| 47 | // ServeStream will create a Websocket client stream connection to the edge |
| 48 | // it blocks and writes the raw data from conn over the tunnel |
| 49 | func (ws *Websocket) ServeStream(options *StartOptions, conn io.ReadWriter) error { |
| 50 | wsConn, err := createWebsocketStream(options, ws.log) |
| 51 | if err != nil { |
| 52 | ws.log.Err(err).Str(LogFieldOriginURL, options.OriginURL).Msg("failed to connect to origin") |
| 53 | return err |
| 54 | } |
| 55 | defer wsConn.Close() |
| 56 | |
| 57 | if ws.isSocks { |
| 58 | dialer := &wsdialer{conn: wsConn} |
| 59 | requestHandler := socks.NewRequestHandler(dialer) |
| 60 | socksServer := socks.NewConnectionHandler(requestHandler) |
| 61 | |
| 62 | _ = socksServer.Serve(conn) |
| 63 | } else { |
| 64 | cfwebsocket.Stream(wsConn, conn) |
| 65 | } |
| 66 | return nil |
| 67 | } |
| 68 | |
| 69 | // StartServer creates a Websocket server to listen for connections. |
| 70 | // This is used on the origin (tunnel) side to take data from the muxer and send it to the origin |
| 71 | func (ws *Websocket) StartServer(listener net.Listener, remote string, shutdownC <-chan struct{}) error { |
| 72 | return cfwebsocket.StartProxyServer(ws.log, listener, remote, shutdownC, cfwebsocket.DefaultStreamHandler) |
| 73 | } |
| 74 | |
| 75 | // createWebsocketStream will create a WebSocket connection to stream data over |
| 76 | // It also handles redirects from Access and will present that flow if |
| 77 | // the token is not present on the request |
| 78 | func createWebsocketStream(options *StartOptions, log *zerolog.Logger) (*cfwebsocket.Conn, error) { |
| 79 | req, err := http.NewRequest(http.MethodGet, options.OriginURL, nil) |
| 80 | if err != nil { |
| 81 | return nil, err |
| 82 | } |
| 83 | req.Header = options.Headers |
| 84 | |
| 85 | dump, err := httputil.DumpRequest(req, false) |
| 86 | log.Debug().Msgf("Websocket request: %s", string(dump)) |
| 87 | |
| 88 | wsConn, resp, err := cfwebsocket.ClientConnect(req, nil) |
| 89 | defer closeRespBody(resp) |
| 90 | |
| 91 | if err != nil && IsAccessResponse(resp) { |
| 92 | wsConn, err = createAccessAuthenticatedStream(options, log) |
| 93 | if err != nil { |
| 94 | return nil, err |
| 95 | } |
| 96 | } else if err != nil { |
| 97 | return nil, err |
| 98 | } |
| 99 | |
| 100 | return &cfwebsocket.Conn{Conn: wsConn}, nil |
| 101 | } |
| 102 | |
| 103 | // createAccessAuthenticatedStream will try load a token from storage and make |
| 104 | // a connection with the token set on the request. If it still get redirect, |
| 105 | // this probably means the token in storage is invalid (expired/revoked). If that |
| 106 | // happens it deletes the token and runs the connection again, so the user can |
| 107 | // login again and generate a new one. |
| 108 | func createAccessAuthenticatedStream(options *StartOptions, log *zerolog.Logger) (*websocket.Conn, error) { |
| 109 | wsConn, resp, err := createAccessWebSocketStream(options, log) |
| 110 | defer closeRespBody(resp) |
| 111 | if err == nil { |
| 112 | return wsConn, nil |
| 113 | } |
| 114 | |
| 115 | if !IsAccessResponse(resp) { |
| 116 | return nil, err |
| 117 | } |
| 118 | |
| 119 | // Access Token is invalid for some reason. Go through regen flow |
| 120 | originReq, err := http.NewRequest(http.MethodGet, options.OriginURL, nil) |
| 121 | if err != nil { |
| 122 | return nil, err |
| 123 | } |
| 124 | if err := token.RemoveTokenIfExists(originReq.URL); err != nil { |
| 125 | return nil, err |
| 126 | } |
| 127 | wsConn, resp, err = createAccessWebSocketStream(options, log) |
| 128 | defer closeRespBody(resp) |
| 129 | if err != nil { |
| 130 | return nil, err |
| 131 | } |
| 132 | |
| 133 | return wsConn, nil |
| 134 | } |
| 135 | |
| 136 | // createAccessWebSocketStream builds an Access request and makes a connection |
| 137 | func createAccessWebSocketStream(options *StartOptions, log *zerolog.Logger) (*websocket.Conn, *http.Response, error) { |
| 138 | req, err := BuildAccessRequest(options, log) |
| 139 | if err != nil { |
| 140 | return nil, nil, err |
| 141 | } |
| 142 | |
| 143 | dump, err := httputil.DumpRequest(req, false) |
| 144 | log.Debug().Msgf("Access Websocket request: %s", string(dump)) |
| 145 | |
| 146 | conn, resp, err := cfwebsocket.ClientConnect(req, nil) |
| 147 | |
| 148 | if resp != nil { |
| 149 | r, err := httputil.DumpResponse(resp, true) |
| 150 | if r != nil { |
| 151 | log.Debug().Msgf("Websocket response: %q", r) |
| 152 | } else if err != nil { |
| 153 | log.Debug().Msgf("Websocket response error: %v", err) |
| 154 | } |
| 155 | } |
| 156 | |
| 157 | return conn, resp, err |
| 158 | } |
| 159 | |