selftests: fib_nexthops: Test cleanup of FDB entries following nexthop deletion

Commit c7cdbe2e ("vxlan: support for nexthop notifiers") registered
a listener in the VXLAN driver to the nexthop notification chain. Its
purpose is to cleanup FDB entries that use a nexthop that is being
deleted.

Test that such FDB entries are removed when the nexthop group that they
use is deleted. Test that entries are not deleted when a single nexthop
in the group is deleted.
Signed-off-by: NIdo Schimmel <idosch@nvidia.com>
Reviewed-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

tools/testing/selftests/net/fib_nexthops.sh

@@ -411,9 +411,16 @@ ipv6_fdb_grp_fcnal()
 	run_cmd "$IP -6 ro add 2001:db8:101::1/128 nhid 103"
 	log_test $? 2 "Route add with fdb nexthop group"
 
+	run_cmd "$IP nexthop del id 61"
+	run_cmd "$BRIDGE fdb get to 02:02:00:00:00:13 dev vx10 self"
+	log_test $? 0 "Fdb entry after deleting a single nexthop"
+
 	run_cmd "$IP nexthop del id 102"
 	log_test $? 0 "Fdb nexthop delete"
 
+	run_cmd "$BRIDGE fdb get to 02:02:00:00:00:13 dev vx10 self"
+	log_test $? 254 "Fdb entry after deleting a nexthop group"
+
 	$IP link del dev vx10
 }
 
@@ -484,9 +491,16 @@ ipv4_fdb_grp_fcnal()
 	run_cmd "$IP ro add 172.16.0.0/22 nhid 103"
 	log_test $? 2 "Route add with fdb nexthop group"
 
+	run_cmd "$IP nexthop del id 12"
+	run_cmd "$BRIDGE fdb get to 02:02:00:00:00:13 dev vx10 self"
+	log_test $? 0 "Fdb entry after deleting a single nexthop"
+
 	run_cmd "$IP nexthop del id 102"
 	log_test $? 0 "Fdb nexthop delete"
 
+	run_cmd "$BRIDGE fdb get to 02:02:00:00:00:13 dev vx10 self"
+	log_test $? 254 "Fdb entry after deleting a nexthop group"
+
 	$IP link del dev vx10
 }