Subject: Re: libpcap filter issue with ppp device
To: Jason Thorpe <thorpej@nas.nasa.gov>
From: None <itojun@iijlab.net>
List: tech-net
Date: 07/25/1999 09:26:17
> > 	The source of problem is that bpf link layer encapsulation type
> > 	code is changed from DLT_PPP to DLT_NULL, in sys/net/if_ppp.c,
> > 	between 1.51 and 1.52.
>Actually, if you look a little more carefully, you'll see that in
>ppp_tty.c:
>#if NBPFILTER > 0
>	/* Switch DLT to PPP-over-serial. */
>	bpf_change_type(&sc->sc_bpf, DLT_PPP_SERIAL, PPP_HDRLEN);
>#endif

	So the bpf encap code is now DLT_PPP_SERIAL, not DLT_PPP.
	In that case, gen_linktype() has to have special case in switch
	(linktype) statement.  It should handle DLT_PPP_SERIAL in the same
	way as DLT_PPP.

>I think I missed part of this thread... what exactly is the problem
>being observed?  I did these changes, and will be more than happy to
>help sort out a fix.

	For example, PR 8052.

itojun