Subject: Re: writable file descriptors in libpcap
To: Jason R Thorpe <thorpej@wasabisystems.com>
From: Andrew Brown <atatat@atatdot.net>
List: tech-net
Date: 10/28/2002 10:01:35
>It is useful to be able to write to the pcap's file descriptor.  This
>is used by some Ethernet simulators (like the experimenal Ethernet
>simulator for the SIMH VAX simulator) which run on many operating systems
>(and thus use the pcap interface to hide most of the OS-specific stuff).

i don't suppose there's some sort of way to indicate to libpcap[*]
that you want a writable descriptor, so that it only opens a writable
descriptor if you need it?

i have "users" in a "bpf" group that can read from the bpf devices,
but not write to them.  now that's broken, and i feel reluctant to
make the bpf devices writable by the group.

[*] it might also be nice to be able to tell libpcap that you want
unbuffered output to the capture file so that you can watch a captured
trace in "real time".  with stdio buffering it, the "playback" sucks
rocks.

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