Date: Fri, 03 Aug 2001 20:04:44 -0300 From: "Daniel C. Sobral" <dcs@newsguy.com> To: Ian Dowse <iedowse@maths.tcd.ie> Cc: "Daniel C. Sobral" <dcs@FreeBSD.org>, cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/netinet ip_output.c Message-ID: <3B6B2E0C.2E83062D@newsguy.com> References: <200108032234.aa06871@salmon.maths.tcd.ie>
next in thread | previous in thread | raw e-mail | index | archive | help
Ian Dowse wrote:
>
> In message <200108031736.f73Ha7Q52998@freefall.freebsd.org>, "Daniel C. Sobral"
> writes:
> > MFS: Avoid dropping fragments in the absence of an interface address.
> >
> > Noticed by: fenner
> > Submitted by: iedowse
> > Not committed to current by: iedowse ;-)
>
> Hey, that's a little unfair :-) I was fixing a real problem in
That's why I put a smile there. If it was fair, no smile would be
required. :-)
> ip_input just before 4.3-RELEASE, where `ia' wasn't always initialised
> before being dereferenced. As I didn't analyse every possible code
> path to ip_output, I added some sanity checks to catch the case of
> `ia' being NULL even though this "couldn't happen" according to
> the surrounding code. It seems that those cases really cannot
> happen, so the sanity checks are never triggered.
>
> Since then however, revision 1.29 introduced a case where ia could
That was me.
> become NULL, and revision 1.131 "fixed" this case by completely
> dropping the fragment if ia is NULL. This revision (1.132) backs
That was ru fixing after me, but making a small mistake while at it.
> out part of 1.131:
>
> 1.31:
> - if (error == 0) {
> + if (error == 0 && ia) {
> ...
> error = (*ifp->if_output)(ifp, m, ...
> } else
> m_freem(m);
>
> 1.32:
> - if (error == 0 && ia) {
> + if (error == 0) {
> ...
> error = (*ifp->if_output)(ifp, m, ...
> } else
> m_freem(m);
>
> and it adds a (now necessary) test that just happens to result in
> similar code to that in -stable; however it is avoiding a case that
> can happen instead of one that can't.
I hope it's the same, and it sure as hell didn't "just happen", as I
modeled it after what you did. :-)
--
Daniel C. Sobral (8-DCS)
dcs@newsguy.com
dcs@freebsd.org
capo@the.secret.bsdconspiracy.net
wow regex humor... I'm a geek
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe cvs-all" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?3B6B2E0C.2E83062D>