Find the ip address of a remote object in .net remoting

Question

I have a client-server application that uses .net remoting. The clients are in a LAN and i do not know their location in advance.

Sometimes we do file transfers and as an optimization I want to determine if a client is in fact on the same machine as the server (it is quite possible). In this case, I only need to do a File.Copy.

Let's say that a client calls the remote method:

RemoteFile server.GetFile(string path);

how can I determine if the client (the requester) is on the same machine?

Answer 1

If you know the IP Address for the server you're calling the remote method from you can use this method to tell whether or not you're on the same machine:

using System.Net;

private bool CheckIfServer(IPAddress serverIP)
{
    // Get all addresses assigned to this machine
    List<IPAddress> ipAddresses = new List<IPAddress>();
    ipAddresses.AddRange(Dns.GetHostAddresses(Dns.GetHostName()));

    // If desirable, also include the loopback adapter
    ipAddresses.Add(IPAddress.Loopback);

    // Detect if this machine contains the IP for the remote server
    // Note: This uses a Lambda Expression, which is only available .Net 3 or later
    return ipAddresses.Exists(i => i.ToString() == serverIP.ToString());
}

If you don't know the IPAddress for your remote server you can easily get it using the server's host name like this:

Dns.GetHostAddresses("remote_host_address")

This returns an IPAddress[], which includes all the resolved address for that host.

Answer 2

Thanks Mel Green for the effort. I could do it like that, but I would find it more useful if I could get the network address from the ObjRef. The information is there (after all, the framework needs to construct the ip packet), but it seems to very obscure. Some people say it cannot be done for security reasons. What do you think?