Moves login logging to the provider level

src/Umbraco.Core/HttpContextExtensions.cs

@@ -0,0 +1,45 @@
+using System.Web;
+
+namespace Umbraco.Core
+{
+    public static class HttpContextExtensions
+    {
+        public static string GetCurrentRequestIpAddress(this HttpContextBase httpContext)
+        {
+            if (httpContext == null)
+            {
+                return "Unknown, httpContext is null";
+            }
+            if (httpContext.Request == null)
+            {
+                return "Unknown, httpContext.Request is null";
+            }
+            if (httpContext.Request.ServerVariables == null)
+            {
+                return "Unknown, httpContext.Request.ServerVariables is null";
+            }
+
+            // From: http://stackoverflow.com/a/740431/5018
+
+            try
+            {
+                var ipAddress = httpContext.Request.ServerVariables["HTTP_X_FORWARDED_FOR"];
+
+                if (string.IsNullOrEmpty(ipAddress))
+                    return httpContext.Request.ServerVariables["REMOTE_ADDR"];
+
+                var addresses = ipAddress.Split(',');
+                if (addresses.Length != 0)
+                    return addresses[0];
+
+                return httpContext.Request.ServerVariables["REMOTE_ADDR"];
+            }
+            catch (System.Exception ex)
+            {
+                //This try catch is to just always ensure that no matter what we're not getting any exceptions caused since
+                // that would cause people to not be able to login
+                return string.Format("Unknown, exception occurred trying to resolve IP {0}", ex);
+            }
+        }
+    }
+}