cloudflared-mirror/carrier/websocket.go

159 lines
4.7 KiB
Go

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.Conn
}
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.Conn, 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.Conn{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
}