使用Global.asax文件重定向用户时发生错误::页面未正确重定向

Question

Issues that I am facing and my questions are as follows:-

1. I am running this code on localhost only, is there any free service or something where I can run this sample webite of mine online? Else the IP address the follwoing code returns is always 127.0.0.1. How do I test my code? Currently I gave static values for IP address.

2. HTTP_X_FORWARDED_FOR is always returning null value. I have read that only HTTP_X_FORWARDED_FOR contains the real IP address of a user.

3. Does REMOTE_ADDR contain real IP address of a user or the IP in it can also be spoofed? I just want to know the country in which the user is sitting in so I can redirect the user based on the ISO codes.

4. One major issue that I am facing is that I am unable to see MasterPageFile property in this Global.asax file.

   What I want is something like this :-

If the ISO code is "FR" then the master to be loaded for the site is FranceMaster.master Else if ISO Code is "GB" then BritainMaster.master file is to be used.

In what part of this file do I set the master pages??

So basically I wanna learn how to Redirect a user based on the ISO code AND set the master page too. I gave hard coded IP address something like 122.87.234.1 then it gave me this error that Couldnt redirect properly. I googled about it and found out that the response.redirect request was being called indefinately. If the following way is not how u redirect a user, how else one does it??

I am sure this kind of stuff has been implemented way too many times. Could someone PLEASE help me out with this one?? I would be grateful. Thanks.

below is the code I have written in Global.asax file :-

<%@ Application Language="C#" %>
<%@ Import Namespace="System" %>
<%@ Import Namespace="System.Net" %>
<%@ Import Namespace="System.Web.UI" %>
<%@ Import Namespace="WorldDomination.Net" %>
<script runat="server">

    void Application_Start(object sender, EventArgs e) 
    {
        // Code that runs on application startup

    }

    void Application_End(object sender, EventArgs e) 
    {
        //  Code that runs on application shutdown

    }

    void Application_Error(object sender, EventArgs e) 
    { 
        // Code that runs when an unhandled error occurs

    }

    void Session_Start(object sender, EventArgs e) 
    {
        // Code that runs when a new session is started

    }

    void Session_End(object sender, EventArgs e) 
    {
        // Code that runs when a session ends. 
        // Note: The Session_End event is raised only when the sessionstate mode
        // is set to InProc in the Web.config file. If session mode is set to StateServer 
        // or SQLServer, the event is not raised.

    }

    void Application_BeginRequest(object sender, EventArgs e)
    {
       string ip = Request.ServerVariables["HTTP_X_FORWARDED_FOR"];
        if (!string.IsNullOrEmpty(ip))
        {
            string[] ipRange = ip.Split(',');
            int le = ipRange.Length - 1;
            string trueIP = ipRange[le];
            ip = trueIP;
        }
        else
        {
            ip = Request.ServerVariables["REMOTE_ADDR"];
        }

       // string userHostIpAddress = "203.1.2.3";
        string userHostIpAddress = ip;
        IPAddress ipAddress;
        if (IPAddress.TryParse(userHostIpAddress, out ipAddress))
        {
            string country = ipAddress.Country(); // return value: UNITED STATES
            string iso3166TwoLetterCode = ipAddress.Iso3166TwoLetterCode(); // return value: US
        }

        if (ipAddress.Iso3166TwoLetterCode() != null)
        {
            if (ipAddress.Iso3166TwoLetterCode().ToLower() == "fr")
            {
                Response.Redirect("www.mysite.fr");
            }
            if (ipAddress.Iso3166TwoLetterCode().ToLower() == "ja")
            {
                Response.Redirect("www.mysite.com/BlockedAccess.aspx");
            }
        }

else
{
 Response.Redirect("www.mysite.com");
}


    }

</script>

EDIT:-

@Chris :: Thanks. I am a bit confused. If the IP address can always be spoofed, how can I ever get the country of a user? I mean how to make sure the user location that I am fetching is correct? Also, there are like 100s of pages on the actual application project that I have to work on. Presently I was just trying it out by making a sample application with just one page. Now, it would be quite a task to set that masterpagefile property in ALL the pages. Is there no way to get it done in a single place?? There are literally hundereds of pages in that web application. Please reply. Thanks.

Answer 1

For the redirect error use Server.Transfer instead of Response.Redirect . The latter will actually initiate a new request and cause the Application_BeginRequest code to fire again, launching your user into an infinite loop.

Regarding your other questions:

1. Regarding hosting, I would just do a search for " free asp.net hosting ", or if you're willing to pay a few bucks for better service find a web host .

2. HTTP_X_FORWARDED_FOR will populate when the request is forwarded via a proxy server. Since you're testing locally and never pass through a proxy server this variable will never be populated. I also noticed that your code is grabbing the last value from HTTP_X_FORWARDED_FOR instead of the first. I believe that will give you the IP address of the last proxy the user passed through and not the actual client IP (maybe someone else can confirm this).

3. The user's IP address can always be spoofed.

4. If you want to dynamically switch your masterpage you will need to do this on the Page_Init event of every page. The best solution would likely be to set a session variable with the appropriate masterpage in your global.asax and then assign that as your masterpage in the Page_Init .

Global.asax:

if (ipAddress.Iso3166TwoLetterCode().ToLower() == "fr")
{
    Session["MasterPage"] = "~/FrenchMaster.master";
    Server.Transfer("www.mysite.fr");

On each page's Page_Init :

this.MasterPageFile = Session["MasterPage"].ToString();

If you're going to go down this route I would suggest creating a custom page class that implements this and that all of your pages in turn inherit from so you don't actually have to copy/paste this code to each page.