Run the example

  1. Install and run the master gateway. Create the needed certificates as described in the Certificate Management.
  2. Install and run the device gateway. Configure the device gateway to connect to the master gateway as described in the Configuration.
  3. Download the C# client library
  4. Copy the certificates.
    • Copy the root certificate of the master gateway to your working directory. As default, the certificate(ca.crt) resides in cert of the installation directory of the master gateway.
    • Copy the administrator certificate and its private key to your working directory.
    • Copy the tenant certificate and its private key to your working directory.
  5. The example uses grpc-dotnet. You can change the example/connectMaster/test/test.csproj file as needed.

  6. Change the server information in example/connectMaster/test/Program.cs as needed.

     // the path of the root certificate
 private const string MASTER_CA_FILE = "../../../../cert/master/ca.crt";   

 // the address of the master gateway
 private const string MASTER_ADDR = "192.168.0.2";
 private const int MASTER_PORT = 4010;  

 // the paths of the administrator certificate and its key 
 private const string ADMIN_CERT_FILE = "../../../../cert/master/admin.crt";
 private const string ADMIN_KEY_FILE = "../../../../cert/master/admin_key.pem";   

 // the paths of the tenant certificate and its key    
 private const string TENANT_CERT_FILE = "../../../../cert/master/tenant1.crt";
 private const string TENANT_KEY_FILE = "../../../../cert/master/tenant1_key.pem";      

 // the following values should be same as the IDs in the corresponding certificates
 private const string TENANT_ID = "tenant1";
 private const string GATEWAY_ID = "gateway1";

  7. Build and run.

     cd example/connectMaster/test
 dotnet run

    To initialize the database, you have to run with -i option once.

1. CLI

With the Command-Line Interface(CLI), you can test 5 functions related to connection management.

===== Main Menu =====

(1) Search devices
(2) Connect to a device synchronously
(3) Manage asynchronous connections
(4) Accept devices
(5) Device menu
(q) Quit

>>>>> Select a menu:

(1) Search devices

To connect devices, you have to know their addresses and related options such as connection mode. By using ConnectMaster.SearchDevice, you can get these information in a subnet.

>>>>> Select a menu: 1
Searching devices in the subnet...

***** Found Devices: 9
{ "deviceID": 544114231, "type": "BIOENTRY_W2", "useDHCP": true, "IPAddr": "192.168.0.104", "port": 51211 }
{ "deviceID": 540092578, "type": "BIOSTATION_L2", "useDHCP": true, "IPAddr": "192.168.0.120", "port": 51211, "useSSL": true }
{ "deviceID": 846, "type": "BIOLITE_N2", "useDHCP": true, "IPAddr": "192.168.0.117", "port": 51211 }
{ "deviceID": 939342898, "type": "BIOSTATION_A2", "useDHCP": true, "connectionMode": "DEVICE_TO_SERVER", "IPAddr": "192.168.0.121", "port": 51211, "useSSL": true }
{ "deviceID": 939342902, "type": "BIOSTATION_A2", "useDHCP": true, "IPAddr": "192.168.0.125", "port": 51211, "useSSL": true }
{ "deviceID": 939504224, "type": "BIOSTATION_A2", "useDHCP": true, "IPAddr": "192.168.0.110", "port": 51211 }
{ "deviceID": 542190033, "type": "FACESTATION_2", "useDHCP": true, "IPAddr": "192.168.0.123", "port": 51211 }
{ "deviceID": 547634389, "type": "BIOSTATION_2", "useDHCP": true, "IPAddr": "192.168.0.100", "port": 51211 }
{ "deviceID": 547634480, "type": "BIOSTATION_2", "useDHCP": true, "IPAddr": "192.168.0.106", "port": 51211 }

(2) Connect to a device synchronously

The simplest way of connecting to a device is to use ConnectMaster.Connect.

>>>>> Select a menu: 2
>> Enter the IP address of the device: 192.168.0.104
>> Enter the port of the device (default: 51211):
>> Use SSL y/n (default: n):
Connecting to the device...
Connected to 544114231

Status: { "deviceID": 544114231, "status": "TCP_CONNECTED", "timestamp": 1582834749 }

(3) Manage asynchronous connections

When you have to manage permanent connections to multiple devices, asynchronous APIs would be a better choice. With these APIs, the gateway will handle connections to devices in the background. For example, if some devices are disconnected, the gateway will try to reconnect them automatically.

>>>>> Select a menu: 3
Getting the async connections...

***** Async Connections: 0

===== Async Menu =====

(1) Add async connections
(2) Delete async connections
(3) Refresh the connection list
(q) Return to Main Menu

>>>>> Select a menu: 1
>> Enter the device ID (Press just ENTER if no more device): 540092578
>> Enter the IP address of the device: 192.168.0.120
>> Enter the port of the device (default: 51211):
>> Use SSL y/n (default: n): y
>> Enter the device ID (Press just ENTER if no more device): 939504224
>> Enter the IP address of the device: 192.168.0.110
>> Enter the port of the device (default: 51211):
>> Use SSL y/n (default: n):
>> Enter the device ID (Press just ENTER if no more device):
Adding async connections...
Getting the async connections...

***** Async Connections: 2
{ "deviceID": 540092578, "IPAddr": "192.168.0.120", "port": 51211, "autoReconnect": true, "useSSL": true }
{ "deviceID": 939504224, "IPAddr": "192.168.0.110", "port": 51211, "autoReconnect": true }

Status: { "deviceID": 939504224, "status": "TCP_CONNECTED", "timestamp": 1582834990 }
Status: { "deviceID": 540092578, "status": "TLS_CONNECTED", "timestamp": 1582834992 }

(4) Accept devices

In some environments, the devices should connect to the gateway, not vice versa. For devices to connect to the gateway, you have to do the followings;

  1. Change the connection mode to DEVICE_TO_SERVER using ConnectMaster.SetConnectionMode.
  2. By default, the gateway will not accept any incoming connections. You have to add the devices to the accept filter using ConnectMaster.SetAcceptFilter.
>>>>> Select a menu: 4
Getting the accept filter...

***** Accept Filter: { }

Getting the pending device list...

***** Pending Devices: 1
{ "deviceID": 939342898, "IPAddr": "192.168.0.121", "lastTry": 1582835070 }

===== Accept Menu =====

(1) Add devices to the filter
(2) Delete devices from the filter
(3) Allow all devices
(4) Disallow all devices
(5) Refresh the pending device list
(q) Return to Main Menu

>>>>> Select a menu: 3
Getting the accept filter...

***** Accept Filter: { "allowAll": true }

Status: { "deviceID": 939342898, "status": "TLS_CONNECTED", "timestamp": 1582835082 }

Apart from the IP address, there are two important options for device connections. You can change the connection mode using ConnectMaster.SetConnectionMode and enable/disable SSL using the SSL APIs.

>>>>> Select a menu: 5
Getting the devices managed by the gateway...

***** Managed Devices: 4
{ "deviceID": 544114231, "IPAddr": "192.168.0.104", "port": 51211, "status": "TCP_CONNECTED" }
{ "deviceID": 540092578, "IPAddr": "192.168.0.120", "port": 51211, "status": "TLS_CONNECTED", "autoReconnect": true, "useSSL": true }
{ "deviceID": 939504224, "IPAddr": "192.168.0.110", "port": 51211, "status": "TCP_CONNECTED", "autoReconnect": true }
{ "deviceID": 939342898, "connectionMode": "DEVICE_TO_SERVER", "IPAddr": "192.168.0.121", "status": "TLS_CONNECTED", "useSSL": true }

===== Device Menu =====

(1) Set connection mode
(2) Enable SSL
(3) Disable SSL
(4) Disconnect devices
(5) Disconnect all devices
(6) Refresh the managed device list
(q) Return to Main Menu

>>>>> Select a menu: 2
Enter the device IDs to enable
>> Enter the device ID (Press just ENTER if no more device): 54414231
>> Enter the device ID (Press just ENTER if no more device):

To change these options, you have to connect to the devices first using menu (2) ~ (4).

2. Synchronous connections

You can use the Synchronous APIs to manage the connections by yourself.

class ConnectMasterSvc {
  //...
  public uint Connect(string gatewayID, Connect.ConnectInfo connectInfo) {
    var request = new ConnectRequest{ GatewayID = gatewayID, ConnectInfo = connectInfo };
    var response = connectMasterClient.Connect(request);

    return response.DeviceID;
  } 

  public void Disconnect(uint[] deviceIDs) {
    var request = new DisconnectRequest{};
    request.DeviceIDs.AddRange(deviceIDs);

    connectClient.Disconnect(request);
  }  
}

  var connInfo = GetConnectInfo();

  if(connInfo != null) {
    try {
      uint devID = connectMasterSvc.Connect(gatewayID, connInfo);
      Console.WriteLine("Connected to {0}", devID);

      // do something with devID

      connectMasterSvc.Disconnect(new uint[]{devID});
    } catch(Exception e) {
      Console.WriteLine("Cannot connect to the device: {0}", e);
    }
  }

3. Asynchronous connections

With the Asynchronous APIs, you only have to register or deregister devices. The gateway will handle all the connection related tasks in the background.

class ConnectMasterSvc {
  //...
  public void AddAsyncConnection(string gatewayID, Connect.AsyncConnectInfo[] asyncConns) {
    var request = new AddAsyncConnectionRequest{ GatewayID = gatewayID };
    request.ConnectInfos.AddRange(asyncConns);

    connectMasterClient.AddAsyncConnection(request);
  }

  public void DeleteAsyncConnection(string gatewayID, uint[] deviceIDs) {
    var request = new DeleteAsyncConnectionRequest{ GatewayID = gatewayID };
    request.DeviceIDs.AddRange(deviceIDs);

    connectMasterClient.DeleteAsyncConnection(request);
  }    
}

You have to use ConnectMaster.GetDeviceList to get the status of the registered devices.

public static void ShowAsyncConnection() {
  try {
    var devList = connectMasterSvc.GetDeviceList(gatewayID);
    var asyncConns = new List<DeviceInfo>();

    for(int i = 0; i < devList.Count; i++) {
      if(devList[i].AutoReconnect) { // AutoReconnect is true for the devices added by AddAsyncConnection
        asyncConns.Add(devList[i]);
      }
    }

    // show asyncConns

  } catch(Exception e) {
    Console.WriteLine("Cannot get the async connections: {0}", e);
  }
}

4. Accept devices

class ConnectMasterSvc {
  //...
  public Connect.AcceptFilter GetAcceptFilter(string gatewayID) {
    var request = new GetAcceptFilterRequest{ GatewayID = gatewayID };
    var response = connectMasterClient.GetAcceptFilter(request);

    return response.Filter;
  }    

  public void SetAcceptFilter(string gatewayID, Connect.AcceptFilter filter) {
    var request = new SetAcceptFilterRequest{ GatewayID = gatewayID, Filter = filter };
    connectMasterClient.SetAcceptFilter(request);
  }   
}

By default, the gateway will not accept any incoming connections. ConnectMaster.GetPendingList can be used to get the devices, which are trying to connect to the gateway but not in the accept filter.

class ConnectMasterSvc {
  //...
  public RepeatedField<Connect.PendingDeviceInfo> GetPendingList(string gatewayID) {
    var request = new GetPendingListRequest{ GatewayID = gatewayID };
    var response = connectMasterClient.GetPendingList(request);

    return response.DeviceInfos;
  }
}

You can allow all the incoming connections by setting AcceptFilter.allowAll to true. Or, you can specify the devices to be allowed in AcceptFilter.deviceIDs.

public static void AllowAll() {
  Connect.AcceptFilter filter = new Connect.AcceptFilter{ AllowAll = true };

  try {
    connectMasterSvc.SetAcceptFilter(gatewayID, filter);
    ShowAcceptFilter();
  } catch(Exception e) {
    Console.WriteLine("Cannot allow all devices: {0}", e);
  }
}

public static void AddDevices() {
  Console.WriteLine("Enter the device IDs to add");

  uint[] deviceIDs = Menu.GetDeviceIDs();

  if(deviceIDs == null) {
    return;
  }

  try {
    Connect.AcceptFilter filter = connectMasterSvc.GetAcceptFilter(gatewayID);
    
    for(int i = 0; i < deviceIDs.Length; i++) {
      if(!filter.DeviceIDs.Contains(deviceIDs[i])) {
        filter.DeviceIDs.Add(deviceIDs[i]);
      }
    }

    filter.AllowAll = false;

    connectMasterSvc.SetAcceptFilter(gatewayID, filter);
    ShowAcceptFilter();
  } catch(Exception e) {
    Console.WriteLine("Cannot add the devices to the filter: {0}", e);
  }     
}

5. Connection status

Apart from ConnectMaster.GetDeviceList, you can also get the realtime update using ConnectMaster.SubscribeStatus.

class ConnectMasterSvc {
  //...
  public IAsyncStreamReader<Connect.StatusChange> Subscribe(int queueSize) {
    var request = new SubscribeStatusRequest{ QueueSize = queueSize };
    var streamCall = connectMasterClient.SubscribeStatus(request);

    return streamCall.ResponseStream;
  }
}

public CancellationTokenSource SubscribeDeviceStatus() {
    var devStatusStream = connectMasterSvc.Subscribe(STATUS_QUEUE_SIZE);

    CancellationTokenSource cancellationTokenSource = new CancellationTokenSource();

    ReceiveStatus(devStatusStream, cancellationTokenSource.Token);

    return cancellationTokenSource;
}

static async void ReceiveStatus(IAsyncStreamReader<Connect.StatusChange> stream, CancellationToken token) {
    Console.WriteLine("Start receiving device status");

    try {
        while(await stream.MoveNext(token)) {
            var statusChange = stream.Current;
            if(statusChange.Status != Connect.Status.TlsNotAllowed && statusChange.Status != Connect.Status.TcpNotAllowed) {
                Console.WriteLine("\n\nStatus: {0}\n", statusChange);        
            }
        }
    } catch (Exception e) {
        Console.WriteLine("Monitoring error: {0}", e);
    } finally {
        Console.WriteLine("Stop receiving device status");
    }
}

6. Connection mode

class ConnectMasterSvc {
  //...
  public void SetConnectionMode(uint[] deviceIDs, ConnectionMode mode) {
    var request = new SetConnectionModeMultiRequest{ ConnectionMode = mode };
    request.DeviceIDs.AddRange(deviceIDs);

    connectClient.SetConnectionModeMulti(request);
  }
}

After setting the connection mode, you have to use different APIs accordingly. With SERVER_TO_DEVICE, you should use the Synchronous APIs or the Asynchronous APIs. to connect to the devices. With DEVICE_TO_SERVER, the AcceptFilter should be configured correctly.

7. SSL

TLS 1.2 can be used for more secure communication between the gateway and devices. Refer to Secure Communication for details.

class ConnectMasterSvc {
  //...
  public void EnableSSL(uint[] deviceIDs) {
    var request = new EnableSSLMultiRequest{};
    request.DeviceIDs.AddRange(deviceIDs);

    connectClient.EnableSSLMulti(request);
  }

  public void DisableSSL(uint[] deviceIDs) {
    var request = new DisableSSLMultiRequest{};
    request.DeviceIDs.AddRange(deviceIDs);

    connectClient.DisableSSLMulti(request);
  }
}

Updated: