selftests: forwarding: Test gretap mirror with next-hop remote

Test mirror to a gretap and an ip6gretap netdevice such that the remote
address of the tunnel is reachable through a next-hop route.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

tools/testing/selftests/net/forwarding/mirror_gre_nh.sh

+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+# This test uses standard topology for testing gretap. See
+# mirror_gre_topo_lib.sh for more details.
+#
+# Test that gretap and ip6gretap mirroring works when the other tunnel endpoint
+# is reachable through a next-hop route (as opposed to directly-attached route).
+
+NUM_NETIFS=6
+source lib.sh
+source mirror_lib.sh
+source mirror_gre_lib.sh
+source mirror_gre_topo_lib.sh
+
+setup_prepare()
+{
+	h1=${NETIFS[p1]}
+	swp1=${NETIFS[p2]}
+
+	swp2=${NETIFS[p3]}
+	h2=${NETIFS[p4]}
+
+	swp3=${NETIFS[p5]}
+	h3=${NETIFS[p6]}
+
+	vrf_prepare
+	mirror_gre_topo_create
+
+	ip address add dev $swp3 192.0.2.161/28
+	ip address add dev $h3 192.0.2.162/28
+	ip address add dev gt4 192.0.2.129/32
+	ip address add dev h3-gt4 192.0.2.130/32
+
+	# IPv6 route can't be added after address. Such routes are rejected due
+	# to the gateway address having been configured on the local system. It
+	# works the other way around though.
+	ip address add dev $swp3 2001:db8:4::1/64
+	ip -6 route add 2001:db8:2::2/128 via 2001:db8:4::2
+	ip address add dev $h3 2001:db8:4::2/64
+	ip address add dev gt6 2001:db8:2::1
+	ip address add dev h3-gt6 2001:db8:2::2
+}
+
+cleanup()
+{
+	pre_cleanup
+
+	ip -6 route del 2001:db8:2::2/128 via 2001:db8:4::2
+	ip address del dev $h3 2001:db8:4::2/64
+	ip address del dev $swp3 2001:db8:4::1/64
+
+	ip address del dev $h3 192.0.2.162/28
+	ip address del dev $swp3 192.0.2.161/28
+
+	mirror_gre_topo_destroy
+	vrf_cleanup
+}
+
+test_gretap()
+{
+	RET=0
+	mirror_install $swp1 ingress gt4 "matchall $tcflags"
+
+	# For IPv4, test that there's no mirroring without the route directing
+	# the traffic to tunnel remote address. Then add it and test that
+	# mirroring starts. For IPv6 we can't test this due to the limitation
+	# that routes for locally-specified IPv6 addresses can't be added.
+	fail_test_span_gre_dir gt4 ingress
+
+	ip route add 192.0.2.130/32 via 192.0.2.162
+	quick_test_span_gre_dir gt4 ingress
+	ip route del 192.0.2.130/32 via 192.0.2.162
+
+	mirror_uninstall $swp1 ingress
+	log_test "mirror to gre with next-hop remote ($tcflags)"
+}
+
+test_ip6gretap()
+{
+	RET=0
+
+	mirror_install $swp1 ingress gt6 "matchall $tcflags"
+	quick_test_span_gre_dir gt6 ingress
+	mirror_uninstall $swp1 ingress
+
+	log_test "mirror to ip6gre with next-hop remote ($tcflags)"
+}
+
+test_all()
+{
+	slow_path_trap_install $swp1 ingress
+	slow_path_trap_install $swp1 egress
+
+	test_gretap
+	test_ip6gretap
+
+	slow_path_trap_uninstall $swp1 egress
+	slow_path_trap_uninstall $swp1 ingress
+}
+
+trap cleanup EXIT
+
+setup_prepare
+setup_wait
+
+tcflags="skip_hw"
+test_all
+
+if ! tc_offload_check; then
+	echo "WARN: Could not test offloaded functionality"
+else
+	tcflags="skip_sw"
+	test_all
+fi
+
+exit $EXIT_STATUS