selftests: net: mscc: ocelot: add a test for egress VLAN modification

For this test we are exercising the VCAP ES0 block's ability to match on
a packet with a given VLAN ID, and push an ES0 TAG A with a VID derived
from VID_A_VAL plus the classified VLAN.

$eth3.200 is the generator port
$eth0 is the bridged DUT port that receives
$eth1 is the bridged DUT port that forwards and rewrites VID 200 to 300
on egress via VCAP ES0
$eth2 is the port that receives from the DUT port $eth1

Since the egress rewriting happens outside the bridging service, VID 300
does not need to be in the bridge VLAN table of $eth1.

Signed-off-by: Vladimir Oltean <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

tools/testing/selftests/drivers/net/ocelot/tc_flower_chains.sh

···
 	ip link set br0 type bridge vlan_filtering 0
 }
 
+test_vlan_egress_modify()
+{
+	printf "Testing egress VLAN modification..		"
+
+	tc qdisc add dev $eth1 clsact
+
+	ip link set br0 type bridge vlan_filtering 1
+	bridge vlan add dev $eth0 vid 200
+	bridge vlan add dev $eth1 vid 200
+
+	tc filter add dev $eth1 egress chain $(ES0) pref 3 \
+		protocol 802.1Q flower skip_sw vlan_id 200 vlan_prio 0 \
+		action vlan modify id 300 priority 7
+
+	tcpdump_start $eth2
+
+	$MZ $eth3.200 -q -c 1 -p 64 -a $eth3_mac -b $eth2_mac -t ip
+
+	sleep 1
+
+	tcpdump_stop
+
+	if tcpdump_show | grep -q "$eth3_mac > $eth2_mac, .* vlan 300"; then
+		echo "OK"
+	else
+		echo "FAIL"
+	fi
+
+	tcpdump_cleanup
+
+	tc filter del dev $eth1 egress chain $(ES0) pref 3
+	tc qdisc del dev $eth1 clsact
+
+	bridge vlan del dev $eth0 vid 200
+	bridge vlan del dev $eth1 vid 200
+	ip link set br0 type bridge vlan_filtering 0
+}
+
 test_skbedit_priority()
 {
 	local num_pkts=100
···
 	test_vlan_pop
 	test_vlan_push
 	test_vlan_ingress_modify
+	test_vlan_egress_modify
 	test_skbedit_priority
 "