Re: [Pysnmp-dev] Potential oneliner bugs

[Ilya E. <il...@gl...>]

Both issues hopefully fixed in CVS (not with your patches). Please, take a 
look.

Thanks,
ilya

On Tue, 14 Aug 2007, Mark M Evans wrote:

> I've run into a couple of issues that I think are bugs in the  
> oneliner implementation.  I'm still learning my way around PySNMP, so  
> apologies if my assumptions or conclusions are incorrect.
> 
> Issue #1:  Oneliner commands "leaking" sockets.
> 
> UdpTransportTarget.openClientMode() creates a transport via  
> UdpSocketTransport().  A side effect of using the default parameters  
> is that a new channel/socket is created and is registered in  
> asyncore.socket_map.  The socket is never removed from  
> asyncore.socket_map, it's never garbage collected and the socket is  
> never closed.  The result is that instantiating and destroying large  
> numbers of CommandGenerators will consume all of the systems socket  
> resources.
> 
> I have a patch that works for me which is to pass a throw away  
> dictionary as the sockMap.  Example:
> 
> pysnmp/entity/rfc3413/oneliner/cmdgen.py:
> 
> class UdpTransportTarget:
>      ...
>      def openClientMode(self):
>          self.transport = udp.UdpSocketTransport(sock=None,
>                                                  sockMap= 
> {}).openClientMode()
>          return self.transport
> 
> Issue #2:  CommandGenerator().nextCmd() does not work with V1 devices.
> 
> V1 devices terminate the list list of OIDs by returning an  
> errorStatus of noSuchName(2), not by returning a value of endOfMib.   
> CommandGenerator().nextCmd() considers a non-false errorStatus as an  
> error (makes sense) and passes that failure to the caller.
> 
> I've hacked my local version to explicitly check for an errorStatus  
> of 2, and clears that errorStatus/Index.  This seems to work, but  
> there may be a cleaner solution.
> 
> pysnmp/entity/rfc3413/oneliner/cmdgen.py:
> 
> class CommandGenerator(AsynCommandGenerator):
>      ...
>      def nextCmd(self, authData, transportTarget, *varNames):
>          def __cbFun(
>              sendRequestHandle, errorIndication, errorStatus,  
> errorIndex,
>              varBindTable, (varBindHead, varBindTotalTable, appReturn)
>              ):
>              if errorStatus == 2:
>                  # V1 terminates GETNEXT with an errorStatus of  
> noSuchName
>                  # rather than a value of endOfMib (which v2c.PDUAPI  
> replaces
>                  # with None).
>                  errorStatus = errorStatus.clone(0)
>                  errorIndex = errorIndex.clone(0)
>                  pass
>              if errorIndication or errorStatus:
>              ...
> 
> Hopefully this information is helpful.
> 
> Regards,
> Mark