Re: [PATCH net v2 2/2] selftests: fib_tests: Add carrier gateway test

[Hangbin Liu]

On Wed, Nov 04, 2026 at 07:56:55PM +0000, Yaroslav Dudkov wrote:
> Test adds routes with a gateway while the nexthop device
> has no carrier and ignore_routes_with_linkdown is enabled on it. The
> routes are added to the main table and to a non-main table, with and
> without a device, for both IPv4 and IPv6. Routes are expected to be
> accepted disregarding the link state.
> 
> Without the previous patch, the IPv6 non-main table cases fail:
> 
> Without fix:
> Gateway validation with carrier down
>     TEST: IPv4 route in main table                                [ OK ]
>     TEST: IPv6 route in main table                                [ OK ]
>     TEST: IPv4 route in non-main table                            [ OK ]
>     TEST: IPv6 route in non-main table                            [FAIL]
>     TEST: IPv4 route in non-main table without device             [ OK ]
>     TEST: IPv6 route in non-main table without device             [FAIL]
>     TEST: IPv4 linkdown flag set                                  [ OK ]
>     TEST: IPv6 linkdown flag set                                  [FAIL]
> 
> With fix:
> Gateway validation with carrier down
>     TEST: IPv4 route in main table                                [ OK ]
>     TEST: IPv6 route in main table                                [ OK ]
>     TEST: IPv4 route in non-main table                            [ OK ]
>     TEST: IPv6 route in non-main table                            [ OK ]
>     TEST: IPv4 route in non-main table without device             [ OK ]
>     TEST: IPv6 route in non-main table without device             [ OK ]
>     TEST: IPv4 linkdown flag set                                  [ OK ]
>     TEST: IPv6 linkdown flag set                                  [ OK ]
> 
> Suggested-by: Ido Schimmel <idosch@xxxxxxxxxx>
> Signed-off-by: Yaroslav Dudkov <aroslavdudkov622@xxxxxxxxx>
> ---
>  tools/testing/selftests/net/fib_tests.sh | 40 ++++++++++++++++++++++++
>  1 file changed, 40 insertions(+)
> 
> diff --git a/tools/testing/selftests/net/fib_tests.sh b/tools/testing/selftests/net/fib_tests.sh
> index 7c47d7fe250d..d7ac3c727f70 100755
> --- a/tools/testing/selftests/net/fib_tests.sh
> +++ b/tools/testing/selftests/net/fib_tests.sh
> @@ -406,10 +406,50 @@ fib_carrier_unicast_test()
>  	cleanup
>  }
>  
> +fib_carrier_gw_test()
> +{
> +	echo
> +	echo "Gateway validation with carrier down"
> +
> +	setup
> +
> +	set -e
> +	$NS_EXEC sysctl -qw net.ipv4.conf.dummy0.ignore_routes_with_linkdown=1
> +	$NS_EXEC sysctl -qw net.ipv6.conf.dummy0.ignore_routes_with_linkdown=1
> +	$IP link set dev dummy0 carrier off
> +	sleep 1
> +	set +e
> +
> +	$IP route add 203.0.113.0/25 via 198.51.100.2 dev dummy0 &> /dev/null
> +	log_test $? 0 "IPv4 route in main table"
> +	$IP -6 route add 2001:db8:10::/64 via 2001:db8:1::2 dev dummy0 &> /dev/null
> +	log_test $? 0 "IPv6 route in main table"
> +
> +	$IP route add 203.0.113.0/25 table 100 via 198.51.100.2 dev dummy0 &> /dev/null
> +	log_test $? 0 "IPv4 route in non-main table"
> +	$IP -6 route add 2001:db8:10::/64 table 100 via 2001:db8:1::2 dev dummy0 &> /dev/null
> +	log_test $? 0 "IPv6 route in non-main table"
> +
> +	$IP route add 203.0.113.128/25 table 100 via 198.51.100.2 &> /dev/null
> +	log_test $? 0 "IPv4 route in non-main table without device"
> +	$IP -6 route add 2001:db8:11::/64 table 100 via 2001:db8:1::2 &> /dev/null
> +	log_test $? 0 "IPv6 route in non-main table without device"
> +
> +	$IP route show table 100 203.0.113.0/25 | \
> +		grep -q "linkdown"
> +	log_test $? 0 "IPv4 linkdown flag set"
> +	$IP -6 route show table 100 2001:db8:10::/64 | \
> +		grep -q "linkdown"
> +	log_test $? 0 "IPv6 linkdown flag set"
> +
> +	cleanup
> +}
> +
>  fib_carrier_test()
>  {
>  	fib_carrier_local_test
>  	fib_carrier_unicast_test
> +	fib_carrier_gw_test
>  }
>  
>  fib_rp_filter_test()
> -- 
> 2.54.0
> 

Tested-by: Hangbin Liu <liuhangbin@xxxxxxxxxx>
Reviewed-by: Hangbin Liu <liuhangbin@xxxxxxxxxx>