Messages in this thread | | | Date | Tue, 19 May 2015 16:51:03 -0400 (EDT) | Subject | Re: [PATCH net v3 2/2] ipv6: fix ECMP route replacement | From | David Miller <> |
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From: Michal Kubecek <mkubecek@suse.cz> Date: Mon, 18 May 2015 20:54:00 +0200 (CEST)
> When replacing an IPv6 multipath route with "ip route replace", i.e. > NLM_F_CREATE | NLM_F_REPLACE, fib6_add_rt2node() replaces only first > matching route without fixing its siblings, resulting in corrupted > siblings linked list; removing one of the siblings can then end in an > infinite loop. > > IPv6 ECMP implementation is a bit different from IPv4 so that route > replacement cannot work in exactly the same way. This should be a > reasonable approximation: > > 1. If the new route is ECMP-able and there is a matching ECMP-able one > already, replace it and all its siblings (if any). > > 2. If the new route is ECMP-able and no matching ECMP-able route exists, > replace first matching non-ECMP-able (if any) or just add the new one. > > 3. If the new route is not ECMP-able, replace first matching > non-ECMP-able route (if any) or add the new route. > > We also need to remove the NLM_F_REPLACE flag after replacing old > route(s) by first nexthop of an ECMP route so that each subsequent > nexthop does not replace previous one. > > Fixes: 51ebd3181572 ("ipv6: add support of equal cost multipath (ECMP)") > Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Can I get some reviews please from interested parties?
As far as I can tell, this faithfully implements the policy we decided upon at the end of the previous thread for this patch. But I could be wrong :-)
Thanks.
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