diff options
authorBenjamin Poirier <bpoirier@cumulusnetworks.com>2020-02-12 10:41:06 +0900
committerDavid S. Miller <davem@davemloft.net>2020-02-16 18:34:31 -0800
commite404b8c7cfb31654c9024d497cec58a501501692 (patch)
parentselftests: forwarding: use proto icmp for {gretap, ip6gretap}_mac testing (diff)
ipv6: Fix route replacement with dev-only route
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@cumulusnetworks.com> Reviewed-by: Michal Kubecek <mkubecek@suse.cz> Signed-off-by: David S. Miller <davem@davemloft.net>
2 files changed, 10 insertions, 3 deletions
diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index 58fbde244381..72abf892302f 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -1102,8 +1102,7 @@ static int fib6_add_rt2node(struct fib6_node *fn, struct fib6_info *rt,
- if (rt_can_ecmp)
- fallback_ins = fallback_ins ?: ins;
+ fallback_ins = fallback_ins ?: ins;
goto next_iter;
@@ -1146,7 +1145,9 @@ 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 = rcu_dereference_protected(*ins,
diff --git a/tools/testing/selftests/net/fib_tests.sh b/tools/testing/selftests/net/fib_tests.sh
index 6dd403103800..60273f1bc7d9 100755
--- a/tools/testing/selftests/net/fib_tests.sh
+++ b/tools/testing/selftests/net/fib_tests.sh
@@ -910,6 +910,12 @@ ipv6_rt_replace_mpath()
check_route6 "2001:db8:104::/64 via 2001:db8:101::3 dev veth1 metric 1024"
log_test $? 0 "Multipath with single path via multipath attribute"
+ # multipath with dev-only
+ add_initial_route6 "nexthop via 2001:db8:101::2 nexthop via 2001:db8:103::2"
+ run_cmd "$IP -6 ro replace 2001:db8:104::/64 dev veth1"
+ check_route6 "2001:db8:104::/64 dev veth1 metric 1024"
+ log_test $? 0 "Multipath with dev-only"
# route replace fails - invalid nexthop 1
add_initial_route6 "nexthop via 2001:db8:101::2 nexthop via 2001:db8:103::2"
run_cmd "$IP -6 ro replace 2001:db8:104::/64 nexthop via 2001:db8:111::3 nexthop via 2001:db8:103::3"