Get IP address of connection - asp.net-mvc-4

Question

I's like to process the IP address and user agent of each signalr connection to my hub. To do this, I have overridden the OnConnected method as shown below.
public override Task OnConnected()
{
string UserAgent = Context.Headers["User-Agent"];
var Request = Context.Request.GetHttpContext().Request;
string IPAddress = Request.UserHostAddress;
// code to process IP address and user agent goes here
return base.OnConnected();
}
Is there a more robust way to retrieve the IP address? The call to Context.Request.GetHttpContext().Request sometimes fails. Using fiddler, I can see that most failures occur if web sockets are used for the underlying connection.

Answer 1

I would suggest pulling the IP address from OWIN's environment dictionary directly:
http://owin.org/
http://owin.org/spec/owin-1.0.0.html
http://owin.org/spec/CommonKeys.html
Request.GetHttpContext() actually works by getting the HttpContextBase from the environment dictionary:
/// <summary>
/// Returns the <see cref="HttpContextBase"/> for this <see cref="IRequest"/>.
/// </summary>
/// <param name="request">The request</param>
public static HttpContextBase GetHttpContext(this IRequest request)
{
object httpContextBaseValue;
if (request.Environment.TryGetValue(typeof(HttpContextBase).FullName, out httpContextBaseValue))
{
return httpContextBaseValue as HttpContextBase;
}
return null;
}
You could write something similar specifically for getting the IP address:
public static string GetRemoteIpAddress(this IRequest request)
{
object ipAddress;
if (request.Environment.TryGetValue("server.RemoteIpAddress", out ipAddress))
{
return ipAddress as string;
}
return null;
}
Not only is this likely more robust, but it also has a much better chance of still working if you port your application to another web server (or perhaps self-host).