Null Reference getting REMOTE_ADDR
- by Josh
I have an ASMX web service running under IIS7 in classic mode. This service has the following code:
try
{
env.ExternalIP = HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"];
}
catch (Exception ex)
{
LogWriter.WriteError(ex);
env.ExternalIP="000.000.000.000";
}
This results in the following stack trace. I only modified the names of usercode call stack here to protect the innocent:
Message: An Exception of type: NullReferenceException occured in method: GetAdditionalServerVar
ExceptionMsg: Object reference not set to an instance of an object.
===Stack Trace===
at System.Web.Hosting.ISAPIWorkerRequestInProc.GetAdditionalServerVar(Int32 index)
at System.Web.Hosting.ISAPIWorkerRequestInProc.GetServerVariable(String name)
at System.Web.HttpRequest.AddServerVariableToCollection(String name)
at System.Web.HttpRequest.FillInServerVariablesCollection()
at System.Web.HttpServerVarsCollection.Populate()
at System.Web.HttpServerVarsCollection.Get(String name)
at System.Collections.Specialized.NameValueCollection.get_Item(String name)
at MyService.MyMethod()
I'm at a loss here as this is very basic plain vanilla code.
EDIT
This gets even stranger. I have added some basic code just wondering what server variables I can get at this point. This fails with the same exception when I try and get all the keys:
System.NullReferenceException: Object
reference not set to an instance of an
object. at
System.Web.Hosting.ISAPIWorkerRequestInProc.GetAdditionalServerVar(Int32
index) at
System.Web.Hosting.ISAPIWorkerRequestInProc.GetServerVariable(String
name) at
System.Web.HttpRequest.AddServerVariableToCollection(String
name) at
System.Web.HttpRequest.FillInServerVariablesCollection()
at
System.Web.HttpServerVarsCollection.Populate()
at
System.Web.HttpServerVarsCollection.get_AllKeys()
at MyService.MyHelper()
When I was looking at the framework code looks like this could happen when the array which caches the server variables isn't populated and it looks like this occurs when there a null pointer to some Context...which seems like a fairly core piece of the framework code.
I suppose it's time to burn up one of our support tickets with Microsoft.
