func()

in client/control.go [205:270]

• 63 lines of code
• 10 McCabe index (conditional complexity)

func (ctl *Control) connectServer() (conn net.Conn, err error) {
	xl := ctl.xl
	if ctl.clientCfg.TCPMux {
		stream, errRet := ctl.session.OpenStream()
		if errRet != nil {
			err = errRet
			xl.Warn("start new connection to server error: %v", err)
			return
		}
		conn = stream
	} else {
		var tlsConfig *tls.Config
		sn := ctl.clientCfg.TLSServerName
		if sn == "" {
			sn = ctl.clientCfg.ServerAddr
		}

		if ctl.clientCfg.TLSEnable {
			tlsConfig, err = transport.NewClientTLSConfig(
				ctl.clientCfg.TLSCertFile,
				ctl.clientCfg.TLSKeyFile,
				ctl.clientCfg.TLSTrustedCaFile,
				sn)

			if err != nil {
				xl.Warn("fail to build tls configuration when connecting to server, err: %v", err)
				return
			}
		}

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