Re: [PATCH net 2/2] selftests: net: add delete nexthop route warning test

[David Ahern <dsahern@kernel.org>]

On 3/31/22 9:46 AM, Nikolay Aleksandrov wrote:
> 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>
> ---
>  tools/testing/selftests/net/fib_nexthops.sh | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/tools/testing/selftests/net/fib_nexthops.sh b/tools/testing/selftests/net/fib_nexthops.sh
> index d444ee6aa3cb..371e3e0c91b7 100755
> --- a/tools/testing/selftests/net/fib_nexthops.sh
> +++ b/tools/testing/selftests/net/fib_nexthops.sh
> @@ -1208,6 +1208,19 @@ ipv4_fcnal()
>  	set +e
>  	check_nexthop "dev veth1" ""
>  	log_test $? 0 "Nexthops removed on admin down"
> +
> +	# nexthop route delete warning
> +	run_cmd "$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()

Reviewed-by: David Ahern <dsahern@kernel.org>