From: Benjamin Poirier <bpoirier@xxxxxxxxxxxxxxxxxxx>
[ Upstream commit e404b8c7cfb31654c9024d497cec58a501501692 ]
After commit 27596472473a ("ipv6: fix ECMP route replacement") it is no
longer possible to replace an ECMP-able route by a non ECMP-able route.
For example,
ip route add 2001:db8::1/128 via fe80::1 dev dummy0
ip route replace 2001:db8::1/128 dev dummy0
does not work as expected.
Tweak the replacement logic so that point 3 in the log of the above commit
becomes:
3. If the new route is not ECMP-able, and no matching non-ECMP-able route
exists, replace matching ECMP-able route (if any) or add the new route.
We can now summarize the entire replace semantics to:
When doing a replace, prefer replacing a matching route of the same
"ECMP-able-ness" as the replace argument. If there is no such candidate,
fallback to the first route found.
Fixes: 27596472473a ("ipv6: fix ECMP route replacement")
Signed-off-by: Benjamin Poirier <bpoirier@xxxxxxxxxxxxxxxxxxx>
Reviewed-by: Michal Kubecek <mkubecek@xxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/ipv6/ip6_fib.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -784,8 +784,7 @@ static int fib6_add_rt2node(struct fib6_
found++;
break;
}
- if (rt_can_ecmp)
- fallback_ins = fallback_ins ?: ins;
+ fallback_ins = fallback_ins ?: ins;
goto next_iter;
}
@@ -825,7 +824,9 @@ next_iter:
}
if (fallback_ins && !found) {
- /* No ECMP-able route found, replace first non-ECMP one */
+ /* No matching route with same ecmp-able-ness found, replace
+ * first matching route
+ */
ins = fallback_ins;
iter = *ins;
found++;
