Re: select() regression in libpcap-devel?

[Guy Harris <guy () alum mit edu>]

On Jul 21, 2009, at 11:12 PM, Guy Harris wrote:

> On Jun 23, 2009, at 7:34 PM, Mike Kershaw wrote:
>
> > (This now actually hits my error catcher where 100 fd highs in a row
> > with no packets triggers a shutdown of the source, since  
> > libpcap-1.0.0
> > seems to not return errors in pcap_dispatch when a netdev is removed
>
> There does not appear to be a way for the memory-mapped interface to  
> directly return such an error.

And not only that, but my test program reports, on my Fedora 9 system  
(2.6.27.25-78.2.6.fc9.i686 kernel), that, if I unplug an interface on  
which I'm capturing:

        select() reports that the descriptor is readable;

        there are *NO* packets to get from the memory-mapped buffer;

	select() does *not* report that there's an exceptional condition on  
the descriptor;

so the kernel and driver appear to be continuously reporting through  
select() a condition *indistinguishable from "there's a packet  
available"* even though no packets are available.
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