Re: [PATCH net,v2,2/2] selftests: fib_tests: Add test cases for IPv4/IPv6 in route notify

[David Ahern <dsahern@kernel.org>]

On 2/15/23 9:26 PM, Lu Wei wrote:
> diff --git a/tools/testing/selftests/net/fib_tests.sh b/tools/testing/selftests/net/fib_tests.sh
> index 5637b5dadabd..4e48154bd195 100755
> --- a/tools/testing/selftests/net/fib_tests.sh
> +++ b/tools/testing/selftests/net/fib_tests.sh
> @@ -9,7 +9,7 @@ ret=0
>  ksft_skip=4
>  
>  # all tests in this script. Can be overridden with -t option
> -TESTS="unregister down carrier nexthop suppress ipv6_rt ipv4_rt ipv6_addr_metric ipv4_addr_metric ipv6_route_metrics ipv4_route_metrics ipv4_route_v6_gw rp_filter ipv4_del_addr ipv4_mangle ipv6_mangle ipv4_bcast_neigh"
> +TESTS="unregister down carrier nexthop suppress ipv6_notify ipv4_notify ipv6_rt ipv4_rt ipv6_addr_metric ipv4_addr_metric ipv6_route_metrics ipv4_route_metrics ipv4_route_v6_gw rp_filter ipv4_del_addr ipv4_mangle ipv6_mangle ipv4_bcast_neigh"
>  
>  VERBOSE=0
>  PAUSE_ON_FAIL=no
> @@ -655,6 +655,94 @@ fib_nexthop_test()
>  	cleanup
>  }
>  
> +fib6_notify_test()
> +{
> +	setup
> +
> +	echo
> +	echo "Fib6 info length calculation in route notify test"
> +	set -e
> +
> +	for i in 10 20 30 40 50 60 70;
> +	do
> +		$IP link add dummy$i type dummy
> +		$IP link set dev dummy$i up
> +		$IP -6 addr add 2002::$i/64 dev dummy$i
> +	done
> +
> +	for i in 10 20 30 40 50 60;
> +	do
> +		$IP -6 route append 100::/64 encap ip6 dst 2002::$i via \
> +		2002::1 dev dummy$i metric 100
> +	done

That creates a multipath route because of a quirk with IPv6. It would be
better to make this explicit by

	nexthops=
	for i in 10 20 30 40 50 60;
	do
		nexthops="$nexthops nexthop encap ip6 dst 2002::$i via 2002::1 dev
dummy$i metric 100"
	done

	$IP -6 route add 100::/64 ${nexthops}

> +
> +fib_notify_test()
> +{
> +	setup
> +
> +	echo
> +	echo "Fib4 info length calculation in route notify test"
> +
> +	set -e
> +
> +	for i in 10 20 30 40 50 60 70;
> +	do
> +		$IP link add dummy$i type dummy
> +		$IP link set dev dummy$i up
> +		$IP addr add 192.168.100.$i/24 dev dummy$i
> +	done
> +
> +	for i in 10 20 30 40 50 60;
> +	do
> +		$IP route append 10.0.0.0/24 encap ip dst 192.168.100.$i via \
> +		192.168.100.1 dev dummy$i metric 100
> +	done

With IPv4 that is not a multipath route but a series of independent
routes. Hence, doing the loop here like I showed above makes sure this
is a proper multipath route.

Thank you for adding the tests.