func()

in client/service.go [240:359]
108 lines of code
17 McCabe index (conditional complexity)

func (svr *Service) login() (conn net.Conn, session *fmux.Session, err error) {
	xl := xlog.FromContextSafe(svr.ctx)
	var tlsConfig *tls.Config
	if svr.cfg.TLSEnable {
		sn := svr.cfg.TLSServerName
		if sn == "" {
			sn = svr.cfg.ServerAddr
		}

		tlsConfig, err = transport.NewClientTLSConfig(
			svr.cfg.TLSCertFile,
			svr.cfg.TLSKeyFile,
			svr.cfg.TLSTrustedCaFile,
			sn)
		if err != nil {
			xl.Warn("fail to build tls configuration when service login, err: %v", err)
			return
		}
	}

	proxyType, addr, auth, err := libdial.ParseProxyURL(svr.cfg.HTTPProxy)
	if err != nil {
		xl.Error("fail to parse proxy url")
		return
	}
	dialOptions := []libdial.DialOption{}
	protocol := svr.cfg.Protocol
	if protocol == "websocket" {
		protocol = "tcp"
		dialOptions = append(dialOptions, libdial.WithAfterHook(libdial.AfterHook{Hook: frpNet.DialHookWebsocket()}))
	}
	if svr.cfg.ConnectServerLocalIP != "" {
		dialOptions = append(dialOptions, libdial.WithLocalAddr(svr.cfg.ConnectServerLocalIP))
	}
	dialOptions = append(dialOptions,
		libdial.WithProtocol(protocol),
		libdial.WithTimeout(time.Duration(svr.cfg.DialServerTimeout)*time.Second),
		libdial.WithKeepAlive(time.Duration(svr.cfg.DialServerKeepAlive)*time.Second),
		libdial.WithProxy(proxyType, addr),
		libdial.WithProxyAuth(auth),
		libdial.WithTLSConfig(tlsConfig),
		libdial.WithAfterHook(libdial.AfterHook{
			Hook: frpNet.DialHookCustomTLSHeadByte(tlsConfig != nil, svr.cfg.DisableCustomTLSFirstByte),
		}),
	)
	conn, err = libdial.Dial(
		net.JoinHostPort(svr.cfg.ServerAddr, strconv.Itoa(svr.cfg.ServerPort)),
		dialOptions...,
	)
	if err != nil {
		return
	}

	defer func() {
		if err != nil {
			conn.Close()
			if session != nil {
				session.Close()
			}
		}
	}()

	if svr.cfg.TCPMux {
		fmuxCfg := fmux.DefaultConfig()
		fmuxCfg.KeepAliveInterval = time.Duration(svr.cfg.TCPMuxKeepaliveInterval) * time.Second
		fmuxCfg.LogOutput = io.Discard
		session, err = fmux.Client(conn, fmuxCfg)
		if err != nil {
			return
		}
		stream, errRet := session.OpenStream()
		if errRet != nil {
			session.Close()
			err = errRet
			return
		}
		conn = stream
	}

	loginMsg := &msg.Login{
		Arch:      runtime.GOARCH,
		Os:        runtime.GOOS,
		PoolCount: svr.cfg.PoolCount,
		User:      svr.cfg.User,
		Version:   version.Full(),
		Timestamp: time.Now().Unix(),
		RunID:     svr.runID,
		Metas:     svr.cfg.Metas,
	}

	// Add auth
	if err = svr.authSetter.SetLogin(loginMsg); err != nil {
		return
	}

	if err = msg.WriteMsg(conn, loginMsg); err != nil {
		return
	}

	var loginRespMsg msg.LoginResp
	_ = conn.SetReadDeadline(time.Now().Add(10 * time.Second))
	if err = msg.ReadMsgInto(conn, &loginRespMsg); err != nil {
		return
	}
	_ = conn.SetReadDeadline(time.Time{})

	if loginRespMsg.Error != "" {
		err = fmt.Errorf("%s", loginRespMsg.Error)
		xl.Error("%s", loginRespMsg.Error)
		return
	}

	svr.runID = loginRespMsg.RunID
	xl.ResetPrefixes()
	xl.AppendPrefix(svr.runID)

	svr.serverUDPPort = loginRespMsg.ServerUDPPort
	xl.Info("login to server success, get run id [%s], server udp port [%d]", loginRespMsg.RunID, loginRespMsg.ServerUDPPort)
	return
}