selftests: mlxsw: Test veto of unsupported VXLAN FDBs

mlxsw doesn't implement offloading of all types of FDB entries that the
VXLAN driver supports. Test that such FDB entries are rejected. That
makes sure that the decision made by the existing validation code in
mlxsw propagates up the stack. It also exercises rollback functionality
in VXLAN, and tests that extack is returned.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

tools/testing/selftests/drivers/net/mlxsw/vxlan_fdb_veto.sh

+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# Test vetoing of FDB entries that mlxsw can not offload. This exercises several
+# different veto vectors to test various rollback scenarios in the vxlan driver.
+
+lib_dir=$(dirname $0)/../../../net/forwarding
+
+ALL_TESTS="
+	fdb_create_veto_test
+	fdb_replace_veto_test
+	fdb_append_veto_test
+	fdb_changelink_veto_test
+"
+NUM_NETIFS=2
+source $lib_dir/lib.sh
+
+setup_prepare()
+{
+	swp1=${NETIFS[p1]}
+	swp2=${NETIFS[p2]}
+
+	ip link add dev br0 type bridge mcast_snooping 0
+
+	ip link set dev $swp1 up
+	ip link set dev $swp1 master br0
+	ip link set dev $swp2 up
+
+	ip link add name vxlan0 up type vxlan id 10 nolearning noudpcsum \
+		ttl 20 tos inherit local 198.51.100.1 dstport 4789
+	ip link set dev vxlan0 master br0
+}
+
+cleanup()
+{
+	pre_cleanup
+
+	ip link set dev vxlan0 nomaster
+	ip link del dev vxlan0
+
+	ip link set dev $swp2 down
+	ip link set dev $swp1 nomaster
+	ip link set dev $swp1 down
+
+	ip link del dev br0
+}
+
+fdb_create_veto_test()
+{
+	RET=0
+
+	bridge fdb add 01:02:03:04:05:06 dev vxlan0 self static \
+	       dst 198.51.100.2 2>/dev/null
+	check_fail $? "multicast MAC not rejected"
+
+	bridge fdb add 01:02:03:04:05:06 dev vxlan0 self static \
+	       dst 198.51.100.2 2>&1 >/dev/null | grep -q mlxsw_spectrum
+	check_err $? "multicast MAC rejected without extack"
+
+	log_test "vxlan FDB veto - create"
+}
+
+fdb_replace_veto_test()
+{
+	RET=0
+
+	bridge fdb add 00:01:02:03:04:05 dev vxlan0 self static \
+	       dst 198.51.100.2
+	check_err $? "valid FDB rejected"
+
+	bridge fdb replace 00:01:02:03:04:05 dev vxlan0 self static \
+	       dst 198.51.100.2 port 1234 2>/dev/null
+	check_fail $? "FDB with an explicit port not rejected"
+
+	bridge fdb replace 00:01:02:03:04:05 dev vxlan0 self static \
+	       dst 198.51.100.2 port 1234 2>&1 >/dev/null \
+	    | grep -q mlxsw_spectrum
+	check_err $? "FDB with an explicit port rejected without extack"
+
+	log_test "vxlan FDB veto - replace"
+}
+
+fdb_append_veto_test()
+{
+	RET=0
+
+	bridge fdb add 00:00:00:00:00:00 dev vxlan0 self static \
+	       dst 198.51.100.2
+	check_err $? "valid FDB rejected"
+
+	bridge fdb append 00:00:00:00:00:00 dev vxlan0 self static \
+	       dst 198.51.100.3 port 1234 2>/dev/null
+	check_fail $? "FDB with an explicit port not rejected"
+
+	bridge fdb append 00:00:00:00:00:00 dev vxlan0 self static \
+	       dst 198.51.100.3 port 1234 2>&1 >/dev/null \
+	    | grep -q mlxsw_spectrum
+	check_err $? "FDB with an explicit port rejected without extack"
+
+	log_test "vxlan FDB veto - append"
+}
+
+fdb_changelink_veto_test()
+{
+	RET=0
+
+	ip link set dev vxlan0 type vxlan \
+	   group 224.0.0.1 dev lo 2>/dev/null
+	check_fail $? "FDB with a multicast IP not rejected"
+
+	ip link set dev vxlan0 type vxlan \
+	   group 224.0.0.1 dev lo 2>&1 >/dev/null \
+	    | grep -q mlxsw_spectrum
+	check_err $? "FDB with a multicast IP rejected without extack"
+
+	log_test "vxlan FDB veto - changelink"
+}
+
+trap cleanup EXIT
+
+setup_prepare
+setup_wait
+
+tests_run
+
+exit $EXIT_STATUS