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

[Yaroslav Dudkov <aroslavdudkov622@gmail.com>]

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@nvidia.com>
Signed-off-by: Yaroslav Dudkov <aroslavdudkov622@gmail.com>
---
 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