selftests: net: add delete nexthop route warning test

[ Upstream commit 392baa339c6a42a2cb088e5e5df2b59b8f89be24 ]

Add a test which causes a WARNING on kernels which treat a
nexthop route like a normal route when comparing for deletion and a
device is specified. That is, a route is found but we hit a warning while
matching it. The warning is from fib_info_nh() in include/net/nexthop.h
because we run it on a fib_info with nexthop object. The call chain is:
 inet_rtm_delroute -> fib_table_delete -> fib_nh_match (called with a
nexthop fib_info and also with fc_oif set thus calling fib_info_nh on
the fib_info and triggering the warning).

Repro steps:
 $ ip nexthop add id 12 via 172.16.1.3 dev veth1
 $ ip route add 172.16.101.1/32 nhid 12
 $ ip route delete 172.16.101.1/32 dev veth1

Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: d5082d386eee ("ipv4: Fix route deletion when nexthop info is not specified")
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/tools/testing/selftests/net/fib_nexthops.sh b/tools/testing/selftests/net/fib_nexthops.sh
index 4c7d33618437c658bf014afff57da52b1a7d36f9..8cca92c969b66d5d1933fbb02689c5bc6117dcc3 100755 (executable)
--- a/tools/testing/selftests/net/fib_nexthops.sh
+++ b/tools/testing/selftests/net/fib_nexthops.sh
@@ -931,6 +931,20 @@ ipv4_fcnal()
        set +e
        check_nexthop "dev veth1" ""
        log_test $? 0 "Nexthops removed on admin down"
+
+       # nexthop route delete warning: route add with nhid and delete
+       # using device
+       run_cmd "$IP li set dev veth1 up"
+       run_cmd "$IP nexthop add id 12 via 172.16.1.3 dev veth1"
+       out1=`dmesg | grep "WARNING:.*fib_nh_match.*" | wc -l`
+       run_cmd "$IP route add 172.16.101.1/32 nhid 12"
+       run_cmd "$IP route delete 172.16.101.1/32 dev veth1"
+       out2=`dmesg | grep "WARNING:.*fib_nh_match.*" | wc -l`
+       [ $out1 -eq $out2 ]
+       rc=$?
+       log_test $rc 0 "Delete nexthop route warning"
+       run_cmd "$IP ip route delete 172.16.101.1/32 nhid 12"
+       run_cmd "$IP ip nexthop del id 12"
 }
 
 ipv4_grp_fcnal()