Date: Thu, 17 Aug 2006 08:56:50 -0500 From: Brooks Davis <brooks@one-eyed-alien.net> To: Yar Tikhiy <yar@comp.chem.msu.su> Cc: drl@MyBSD.org.my, freebsd-stable@freebsd.org, Stefan Bethke <stb@lassitu.de>, Andrew Thompson <thompsa@freebsd.org> Subject: Re: Default route (IPv4) demolished by destroying clone (gif/gre) interface Message-ID: <20060817135650.GA89359@lor.one-eyed-alien.net> In-Reply-To: <20060817071651.GB94460@comp.chem.msu.su> References: <20060815040736.2f85f090.drl@MyBSD.org.my> <9405D801-3435-419A-9541-E1A9B2CF26D2@lassitu.de> <20060816081130.GB81271@comp.chem.msu.su> <FED9705F-B445-4495-B90F-A656AAA966EE@lassitu.de> <20060816145419.GB62485@lor.one-eyed-alien.net> <20060816155844.GA85503@comp.chem.msu.su> <20060816171524.GA63928@lor.one-eyed-alien.net> <20060816204927.GA73369@heff.fud.org.nz> <20060816205913.GA69877@lor.one-eyed-alien.net> <20060817071651.GB94460@comp.chem.msu.su>
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--ZGiS0Q5IWpPtfppv Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Aug 17, 2006 at 11:16:51AM +0400, Yar Tikhiy wrote: > On Wed, Aug 16, 2006 at 03:59:13PM -0500, Brooks Davis wrote: > > On Thu, Aug 17, 2006 at 08:49:27AM +1200, Andrew Thompson wrote: > > > On Wed, Aug 16, 2006 at 12:15:25PM -0500, Brooks Davis wrote: > > > > On Wed, Aug 16, 2006 at 07:58:44PM +0400, Yar Tikhiy wrote: > > > > > On Wed, Aug 16, 2006 at 09:54:19AM -0500, Brooks Davis wrote: > > > > > > On Wed, Aug 16, 2006 at 10:23:13AM +0200, Stefan Bethke wrote: > > > > > > >=20 > > > > > > > Ouch. Don't ppp(8), OpenVPN etc. destroy the tun interface th= ey're =20 > > > > > > > using when they exit? Flushing all routes then would be rath= er =20 > > > > > > > harmful. I'm glad I haven't updated to a newer -stable yet t= hen :-) > > > > > >=20 > > > > > > In general, no since tun interfaces can not be destroyed. > > > > >=20 > > > > > Did you mean "in particular"? :-) > > > > >=20 > > > > > The problem can be triggered by destroying any interface that can > > > > > be destroyed. Just imagine getting rid of a defunct gif tunnel on > > > > > a remote router, or removing an unused vlan, and totally losing > > > > > connectivity to the router due to its default route having been > > > > > flushed. The scenario still can be quite unpleasant. I'd rather > > > > > change the default for $removable_route_flush to NO and let the > > > > > kernel choose which routes should be flushed upon the physical > > > > > ejection or software destruction of an interface. Note that this > > > > > doesn't include static_routes_${ifn}, which are handled separately > > > > > by pccard_ether_stop(). > > > >=20 > > > > Agreed. That code shouldn't be on by default. I've disabled in it= HEAD > > > > and will MFC in a few days. As another poster said, I'm not even s= ure > > > > it should exist as an option. > > >=20 > > > Thanks for fixing this up, it certainly was odd to be flushing routes= in > > > userland. I have one more bug report from the ifnet/devd change to lo= ok > > > at where renamed interfaces give some sort of an error. > >=20 > > It is a rather weird bit of code. It deletes all IPv4 routes on exit. > > I suspect it's a hack left over from before interface removal really > > worked. I may just delete the code in HEAD after the MFC. I think we > > could also remove the arp flush or move it into "netif stop" and narrow > > it with the -i option. >=20 > The -i option may not work in that case because the interface has > ceased to exist by the time devd(8) gets the notification and runs > /etc/pccard_ether. It could be better just to remove the arp flush > completely. The kernel should take care of the arp entries by itself. > Thanks! I decided to leave it in, but protect it with ifexists. That way we preserve the scripts secondary roll of downing an interface. I'll probalby move it into network.subr:ifconfig_down() at some point. -- Brooks --ZGiS0Q5IWpPtfppv Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.5 (FreeBSD) iD8DBQFE5HWiXY6L6fI4GtQRAqUcAJ0VZKadJNZoAqceIY/tOTA/at2yZwCdHSjF JagXrJgmsD8YPpCZV4TfySo= =9YlG -----END PGP SIGNATURE----- --ZGiS0Q5IWpPtfppv--
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