Subject: Re: [PATCH net v2] selftests/fib_tests: ping from dummy0 in fib_rp_filter_test()

From: David Ahern <[email-masked]>
Date: Mon, 29 Nov 2021 18:16:48 -0700

On 11/29/21 5:49 PM, Peilin Ye wrote:
> diff --git a/tools/testing/selftests/net/fib_tests.sh b/tools/testing/selftests/net/fib_tests.sh
> index 5abe92d55b69..b8bceae00f8e 100755
> --- a/tools/testing/selftests/net/fib_tests.sh
> +++ b/tools/testing/selftests/net/fib_tests.sh
> @@ -453,15 +453,19 @@ fib_rp_filter_test()
>  	$NS_EXEC sysctl -qw net.ipv4.conf.all.accept_local=1
>  	$NS_EXEC sysctl -qw net.ipv4.conf.all.route_localnet=1
>  
> +	$NS_EXEC tc qd add dev dummy0 parent root handle 1: fq_codel
> +	$NS_EXEC tc filter add dev dummy0 parent 1: protocol arp basic action mirred egress redirect dev dummy1
> +	$NS_EXEC tc filter add dev dummy0 parent 1: protocol ip basic action mirred egress redirect dev dummy1
> +
>  	$NS_EXEC tc qd add dev dummy1 parent root handle 1: fq_codel
>  	$NS_EXEC tc filter add dev dummy1 parent 1: protocol arp basic action mirred egress redirect dev lo
>  	$NS_EXEC tc filter add dev dummy1 parent 1: protocol ip basic action mirred egress redirect dev lo
>  	set +e
>  
> -	run_cmd "ip netns exec ns1 ping -I dummy1 -w1 -c1 198.51.100.1"
> +	run_cmd "ip netns exec ns1 ping -I dummy0 -w1 -c1 198.51.100.1"
>  	log_test $? 0 "rp_filter passes local packets"
>  
> -	run_cmd "ip netns exec ns1 ping -I dummy1 -w1 -c1 127.0.0.1"
> +	run_cmd "ip netns exec ns1 ping -I dummy0 -w1 -c1 127.0.0.1"
>  	log_test $? 0 "rp_filter passes loopback packets"
>  
>  	cleanup
> 

confused by the point of this test if you are going to change dummy1 to
dummy0. dummy0 has 198.51.100.1 assigned to it, so the ping should
always work.