if bpf fd's select()able?

[Lev Walkin]

Dmitry Morozovsky wrote:
> Dear colleagues,
> 
> [all below is for 4-STABLE]
> 
> I'm trying to write effective arp scanner for multi-interface router (esp.
> multi-vlan); I plan to use multiple bpf devices attached to different
> interfaces emitting ARP requests and filters listening to ARP replies; the most
> natural way to multiplex them for me is select().
> 
> However, my tests show that select()ing bpf fd does not lead to trigger packets
> available to bpf filter; the process hangs in select state while parallel
> tcpdump process shows packets desired *and* is in bpf state.
> 
> Am I missing something "base"? References (surely, I'd already read
> manpages for bpf, pcap and related -- but did I still missed something
> serious?) would be greatly appreciated.

Yes, you're missing the interactive mode.

Refer to BIOCIMMEDIATE in the bpf(4) manual page.


-- 
Lev Walkin
vlm at netli.com