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Callisto82 / tftp.net

Implements the TFTP (Trivial File Transfer) protocol (client/server) in an easy-to-use C#/.NET library.
Microsoft Public License
80 stars 38 forks source link

Exception From SendOptionAcknowledgementBase When errorMessage Is Null #2

Closed hiowaguy closed 5 years ago

hiowaguy commented 6 years ago

I have run into an issue where an unhandled exception is raised that terminates my program when the software I'm communicating with responds to an option acknowledgement with a TFTP Error with no message. I don't seem to be able to handle the exception from my code since it's raised from the context of the UdpChannel (BeginReceive) thread.

Sequence: (Me => My Program with TFTP.NET) (Them => The External Software)

Me: Opcode: Option Acknowledgement (6) Option: ...

Them: Opcode: Error Code (5) Error Code: Illegal TFTP Operation (4) Message: 0x0 (NULL)

Here is the stack trace I see for this: System.ArgumentException: You must provide an errorMessage. at Tftp.Net.TftpErrorPacket..ctor(UInt16 errorCode, String errorMessage) at Tftp.Net.Transfer.States.ReceivedError..ctor(TftpTransfer context, Error error) at Tftp.Net.Transfer.SendOptionAcknowledgementBase.OnError(Error command) at Tftp.Net.Error.Visit(ITftpCommandVisitor visitor) at Tftp.Net.Transfer.States.StateThatExpectsMessagesFromDefaultEndPoint.OnCommand(ITftpCommand command, EndPoint endpoint) at Tftp.Net.Trace.LoggingStateDecorator.OnCommand(ITftpCommand command, EndPoint endpoint) at Tftp.Net.Transfer.TftpTransfer.connection_OnCommandReceived(ITftpCommand command, EndPoint endpoint) at Tftp.Net.Channel.UdpChannel.RaiseOnCommand(ITftpCommand command, IPEndPoint endpoint) at Tftp.Net.Channel.UdpChannel.UdpReceivedCallback(IAsyncResult result) at System.Net.LazyAsyncResult.Complete(IntPtr userToken) at System.Net.ContextAwareResult.CompleteCallback(Object state) at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Net.ContextAwareResult.Complete(IntPtr userToken) at System.Net.LazyAsyncResult.ProtectedInvokeCallback(Object result, IntPtr userToken) at System.Net.Sockets.BaseOverlappedAsyncResult.CompletionPortCallback(UInt32 errorCode, UInt32 numBytes, NativeOverlapped nativeOverlapped) at System.Threading._IOCompletionCallback.PerformIOCompletionCallback(UInt32 errorCode, UInt32 numBytes, NativeOverlapped pOVERLAP)

Cugio commented 5 years ago

https://github.com/Cugio/tftp.net/commit/094d96e3f276ed56fd8297f637820336dfda287c

Callisto82 commented 5 years ago

THanks again for the analysis. I just merged your PR.