On Tue, Feb 25, 2014 at 06:59:10PM +0000, Pierluigi Rolando wrote: > Hi, > > This patch fixes a situation where a route that becomes unviable because of a > configuration change (i.e. next hop of its new version is unreachable) is > marked as not installed internally, but actually remains in the kernel > routing table until a subsequent configuration change makes the next hop > reachable again. > > The code that updates static routes seems to process changes as deletions + > insertions, but if the insertion can't happen for any reason the deletion > won't happen as well, even though the route is already marked as uninstalled > by then. When that happens BIRD and the kernel get out of sync until BIRD > tries to install the route again, which might be never. > > The patch is supposed to fix the problem by detecting routes that (a) have > changed but (b) are not getting deleted because their updated version can't > get installed, and deletes them anyway. There's also a quick sanity check to > make sure we don't end up with 3 states for the installed flag (which should > obviously be a base 2 boolean), even though 3 states are needed temporarily > when processing updates.
Thanks, the analysis and the patch is more-or-less correct, with one minor note:
> for (r2 = r->mp_next; r2; r2 = r2->mp_next)
> - if (r2->installed)
> + if (r2->installed > 0)
> {
> struct mpnh *nh = alloca(sizeof(struct mpnh));
> nh->gw = r2->via;
No need for this change, secondary multipath nodes from mp_next cannot
be -1, they are not modified in static_match() but in static_add() and
the meaning is slightly different.
--
Elen sila lumenn' omentielvo
Ondrej 'SanTiago' Zajicek (email: santi...@crfreenet.org)
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"To err is human -- to blame it on a computer is even more so."
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