Unhandled Null Reference Exception

[shaneh20]

Hi, I've been using your nice library for a while now and just today we had an issue where we couldn't start one of our windows services that is using this ssdp lib. It was crashing with an unhandled exception being logged in Event Viewer:

Framework Version: v4.0.30319
Description: The process was terminated due to an unhandled exception.
Exception Info: System.NullReferenceException
at Discovery.SSDP.MessageParser.GetNotifyMessage(System.Collections.Generic.List`1<System.String>)
at Discovery.SSDP.MessageParser.Parse(Byte[])
at Discovery.SSDP.Agents.AgentBase.ParseResponse(System.Object)
at System.Threading.QueueUserWorkItemCallback.WaitCallback_Context(System.Object)
at System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)
at System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)
at System.Threading.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem()
at System.Threading.ThreadPoolWorkQueue.Dispatch()
at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback()

I've got a feeling there might be some other SSDP software on our network that is trying to discover its server by broadcasting out the "M-SEARCH * HTTP/1.1" string on port 1900. Looking at your code in the MessageParser class it looks like this might be causing the issue in GetNotifyMessage.

Changing this ssdp lib to use a different port fixed the problem, so it looks like when it uses the default 1900 port it's not handling messages received from other SSDP clients properly.

[simongh]

Thanks for taking the time to get in touch with me. I think i noticed this bug when working on a new version. I'll take a look & see if I can track down the issue. Thanks again Simon

…

On Wed, 27 Mar 2019 at 01:44, shaneh20 ***@***.***> wrote: Hi, I've been using your nice library for a while now and just today we had an issue where we couldn't start one of our windows services that is using this ssdp lib. It was crashing with an unhandled exception being logged in Event Viewer: Framework Version: v4.0.30319 Description: The process was terminated due to an unhandled exception. Exception Info: System.NullReferenceException at Discovery.SSDP.MessageParser.GetNotifyMessage(System.Collections.Generic.List`1<System.String>) at Discovery.SSDP.MessageParser.Parse(Byte[]) at Discovery.SSDP.Agents.AgentBase.ParseResponse(System.Object) at System.Threading.QueueUserWorkItemCallback.WaitCallback_Context(System.Object) at System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean) at System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean) at System.Threading.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem() at System.Threading.ThreadPoolWorkQueue.Dispatch() at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback() I've got a feeling there might be some other SSDP software on our network that is trying to discover its server by broadcasting out the "M-SEARCH * HTTP/1.1" string on port 1900. Looking at your code in the MessageParser class it looks like this might be causing the issue in GetNotifyMessage. Changing this ssdp lib to use a different port fixed the problem, so it looks like when it uses the default 1900 port it's not handling messages received from other SSDP clients properly. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#2>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ABZ7T-sf4dZCJpMHwpfS_C1UMLKU8-dmks5vas0RgaJpZM4cMx2j> .