.Net Remoting

1. .Net Remoting Pooja Panjala 06/17/10

2. .net Security Agenda • What is .net Remoting? • Explanation of terms • Architecture • Implementation of Remoting • Sample example

3. .net Security What is Remoting in .Net? • It is a mechanism for communicating between objects which are not in the same process. • Enables different applications located on same computer or different computer to communicate with objects. • Provides a framework that allows objects to interact with each other across application domains.

4. .net Security Remoting Components • A remotable object: Which is an object that contain some properties and methods located in one application domain and you need to call its methods or properties from another application domain or process. • A host application: This is the host of the remotable object also called as the server application. The main task of this host is to listen to requests for the hosted remotable object. • A client application: This is the application which makes requests for the remotable object.

5. .net Security Remote Objects • It is an object outside the application domain of the caller application. • Any object can be changed into a remote object by deriving it from MarshalByRefObject, or by making it serializable either by adding the [Serializable]tag or by implementing the ISerializable interface.

6. .net Security Types of .NET Remotable Objects • Single Call object: Service one and only one request coming in. • Singleton Call object : Service multiple clients and is useful when data needs to be shared explicitly between several clients. • Client-Activated object : Richer than singleton in many aspects as they can store the state information between method calls for its specific client.

7. .net Security Proxy object • A proxy object is an object that acts in place of some other object. • Created when client activates a remote object. • It is an instance of the TransparentProxy class, directly available to the client to communicate with the remote object.

8. .net Security Marshalling • Specifies how a remote object is exposed to the client application. • It is the process of packaging an object access request in one application domain and passing that request to another domain.

9. .net Security Two methods • Marshalling objects by value • analogous to having a copy of the server object at the client. • Marshal by value classes must either be marked with the [Serilaizable] attribute in order to use the default serialization, or must implement the ISerializable interface. • Marshalling objects by reference • analogous to having a pointer to the object. • Marshal by reference classes must inherit from System.MarshalByRefObject.

10. .net Security Channels • It is a mechanism by which a stream of bytes is sent from one point to the other. • Two pre-defined .NET Remoting channels existing in System.Runtime.Remoting.Channels are TCPChannel and the HTTPChannel.

11. .net Security Serialization formatters • .NET Remoting uses serialization to copy marshal-by-value objects, and to send reference of objects which are marshal-by-reference, between application domains. • Formatters are used for encoding and decoding the messages before they are transported by the channel.

12. .net Security Two types of formatters • binary(System.Runtime.Serialization.Formatters.Binary) • Use binary encoding where performance is critical • Small size • SOAP (System.Runtime.Serialization.Formatters.Soap) • Use XML encoding where interoperability with other remoting frameworks is essential.

13. .net Security Architecture • Client’s call • proxy to remote object • method invocation on remote object • Message encoded • Call sent to the server using channel

14. .net Security Implementation of Remoting • Create a Remotable Object MyRemotableObject.cs namespace RemotableObjects { public class MyRemotableObject : MarshalByRefObject { public MyRemotableObject() { } public void SetMessage(string message) { Cache.GetInstance().MessageString = message; } } }

15. .net Security Create a Server to Expose the Remotable Object namespace RemotableObjects { public class frmRServer : System.Windows.Forms.Form, IObserver { private System.Windows.Forms.TextBox textBox1; private MyRemotableObject remotableObject; private System.ComponentModel.Container components = null; public frmRServer() { InitializeComponent(); remotableObject = new MyRemotableObject(); // using TCP protocol TcpChannel channel = new TcpChannel(8080); ChannelServices.RegisterChannel(channel); RemotingConfiguration.RegisterWellKnownServiceType( typeof(MyRemotableObject),"HelloWorld", WellKnownObjectMode.Singleton); RemotableObjects.Cache.Attach(this); } } }

16. .net Security • Create a Client to Use the Remotable Object • namespace RemotableObjects • { • public class frmRCleint : System.Windows.Forms.Form • { • private System.Windows.Forms.TextBox textBox1; • MyRemotableObject remoteObject; • private System.ComponentModel.Container components = null; • public frmRCleint() • { • InitializeComponent(); • // using TCP protocol • // running both client and server on same machines • TcpChannel chan = new TcpChannel(); • ChannelServices.RegisterChannel(chan); • // Create an instance of the remote object • remoteObject = (MyRemotableObject) Activator.GetObject( typeof(MyRemotableObject),"tcp://localhost:8080/HelloWorld"); • } • private void textBox1_TextChanged(object sender, System.EventArgs e) • { • remoteObject.SetMessage(textBox1.Text); • } • } • }

17. .net Security Step 1: Creating the Server Server.cs using System;using System.IO;using System.Runtime.Remoting;using System.Runtime.Remoting.Channels.HTTP;namespace Server { public class ServiceClass : MarshalByRefObject { public void AddMessage (String msg) { Console.WriteLine (msg); } } public class ServerClass { public static void Main () { HTTPChannel c = new HTTPChannel (1095); ChannelServices.RegisterChannel (c); RemotingServices.RegisterWellKnownType ("Server","Server.ServiceClass","ServiceClass", WellKnownObjectMode.Singleton); Console.WriteLine ("Server ON at 1095"); Console.WriteLine ("Press enter to stop the server..."); Console.ReadLine (); } }}

18. .net Security Compile this file using csc /r:system.runtime.remoting.dll /r:system.dll Server.cs This will generate a executable Server.exe , run this file and on the console u should see Server ON at 1095 Press enter to stop the server...

19. .net Security Step 2: a) Creating Client Proxy soapsuds -url:http://<Machine Name >:1095/ServiceClass -oa:Server.dll This will create a proxy called Server.dll which will be used to access the remote object

20. .net Security Step 2: b) Creating Client Code TheClient.cs using System; using System.Runtime.Remoting; using System.Runtime.Remoting.Channels.HTTP;using Server;public class TheClient {public static void Main (string[] args) {HTTPChannel c = new HTTPChannel (1077); ChannelServices.RegisterChannel (c);ServiceClass sc = (ServiceClass) Activator.GetObject (typeof (ServiceClass),http://<Machine where Service is Running >:1095/ServiceClass); sc.AddMessage ("Hello From Client"); }}

21. .net Security Compile it using csc /r:system.runtime.remoting.dll /r:system.dll /r:Server.dll TheClient.cs The output will be TheClient.exe, run it and check the server console on Machine 1, you will see "Hello From Client".

22. .net Security References • http://msdn.microsoft.com/en-us/library/2e7z38xb(v=VS.71).aspx • http://www.codeproject.com/KB/IP/Net_Remoting.aspx

23. .net Security Thank you!