I have an asp.net page (c#) that I execute daily.
I would like to know if there is a way to allow it to be executed only when its requested by the same ip as the server. Meaning, if another ip runs the page, nothing will happen or it will be redirected.
You can use Request.IsLocal to check if the request is local.
You can query the IsLocal property of the HttpRequest
http://msdn.microsoft.com/en-us/library/system.web.httprequest.islocal.aspx
Following works also with lower framework than 2.0 (but HttpRequest.IsLocal is preferable if available).
C#
public static void redirectIfNotServer(string redirectUrl)
{
// Look for a proxy address first
var IP = HttpContext.Current.Request.ServerVariables("HTTP_X_FORWARDED_FOR");
//Trim and lowercase IP if not null
if ((IP != null)) {
IP = IP.ToLower().Trim;
}
if (IP == null || (IP.Equals("unknown"))) {
//If IP is null use different detection method, else pull the correct IP from list.
IP = HttpContext.Current.Request.ServerVariables("REMOTE_ADDR").ToLower().Trim();
}
List<string> IPs = null;
if (IP.IndexOf(",") > -1) {
IPs = IP.Split(',').ToList();
} else {
IPs = new string[] { IP }.ToList();
}
var serverIP = HttpContext.Current.Request.ServerVariables("LOCAL_ADDR");
var ipIsServerIp = (from ipAddress in IP swhere ipAddress == serverIP).Any();
if (!ipIsServerIp) {
HttpContext.Current.Response.Redirect(redirectUrl);
}
}
VB.NET
Public Shared Sub redirectIfNotServer(ByVal redirectUrl As String)
' Look for a proxy address first
Dim IP = HttpContext.Current.Request.ServerVariables("HTTP_X_FORWARDED_FOR")
'Trim and lowercase IP if not null
If Not IP Is Nothing Then
IP = IP.ToLower().Trim
End If
If IP Is Nothing OrElse (IP.Equals("unknown")) Then
'If IP is null use different detection method, else pull the correct IP from list.
IP = HttpContext.Current.Request.ServerVariables("REMOTE_ADDR").ToLower().Trim
End If
Dim IPs As List(Of String)
If IP.IndexOf(",") > -1 Then
IPs = IP.Split(","c).ToList
Else
IPs = New String() {IP}.ToList
End If
Dim serverIP = HttpContext.Current.Request.ServerVariables("LOCAL_ADDR")
Dim ipIsServerIp = (From ipAddress In IPs Where ipAddress = serverIP).Any
If Not ipIsServerIp Then
HttpContext.Current.Response.Redirect(redirectUrl)
End If
End Sub
This:
Request.ServerVariables["REMOTE_ADDR"]
will get you the remote ip, then just compare it to your server ip or "localhost"
Use the UserHostAddress property on the HttpRequest object to get the users address.
Use the LOCAL_ADDR variable with the ServerVariables property to get the servers address from the request object.
Fernando has the better solution by checking the IsLocal property.
