[patch] [rfc] Re: udhcpc eating too much cpu

Thu Jan 17 06:22:52 PST 2008

On Thu, 17 Jan 2008, Paul Fox wrote:

>  > +	if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &filter_prog,
>  > +				sizeof(filter_prog)) < 0)
>  > +		bb_perror_msg_and_die("setsockopt");
>  > +	DEBUG("attached filter to raw socket fdr %d", fd);
>
> is this supported on all kernel versions that busybox currently
> supports?  i simply don't know, having never used BPF, and i'm
> wondering whether this needs to be configurable.

Quick search and found this note:

"At least from kernel version 2.1.96, Linux supports a packet capture
system called ``Linux Socket Filter'', which is based on BPF and
provides kernel level packet filtering."

  http://www.wand.net.nz/pubs/22/html/node28.html

Cheers,

-- 
Cristian