selftests: mlxsw: Add egress VID classification test

After routing, the device always consults a table that determines the
packet's egress VID based on {egress RIF, egress local port}. In the
unified bridge model, it is up to software to maintain this table via
REIV register.

The table needs to be updated in the following flows:
1. When a RIF is set on a FID, for each FID's {Port, VID} mapping, a new
   {RIF, Port}->VID mapping should be created.
2. When a {Port, VID} is mapped to a FID and the FID already has a RIF,
   a new {RIF, Port}->VID mapping should be created.

Add a test to verify that packets get the correct VID after routing,
regardless of the order of the configuration.

 # ./egress_vid_classification.sh
 TEST: Add RIF for existing {port, VID}->FID mapping                 [ OK ]
 TEST: Add {port, VID}->FID mapping for FID with a RIF               [ OK ]
Signed-off-by: Amit Cohen <amcohen@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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

+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+# Test VLAN classification after routing and verify that the order of
+# configuration does not impact switch behavior. Verify that {RIF, Port}->VID
+# mapping is added correctly for existing {Port, VID}->FID mapping and that
+# {RIF, Port}->VID mapping is added correctly for new {Port, VID}->FID mapping.
+
+# +-------------------+                   +--------------------+
+# | H1                |                   | H2                 |
+# |                   |                   |                    |
+# |         $h1.10 +  |                   |  + $h2.10          |
+# |   192.0.2.1/28 |  |                   |  | 192.0.2.3/28    |
+# |                |  |                   |  |                 |
+# |            $h1 +  |                   |  + $h2             |
+# +----------------|--+                   +--|-----------------+
+#                  |                         |
+# +----------------|-------------------------|-----------------+
+# | SW             |                         |                 |
+# | +--------------|-------------------------|---------------+ |
+# | |        $swp1 +                         + $swp2         | |
+# | |              |                         |               | |
+# | |     $swp1.10 +                         + $swp2.10      | |
+# | |                                                        | |
+# | |                           br0                          | |
+# | |                       192.0.2.2/28                     | |
+# | +--------------------------------------------------------+ |
+# |                                                            |
+# |      $swp3.20 +                                            |
+# | 192.0.2.17/28 |                                            |
+# |               |                                            |
+# |         $swp3 +                                            |
+# +---------------|--------------------------------------------+
+#                 |
+# +---------------|--+
+# |           $h3 +  |
+# |               |  |
+# |        $h3.20 +  |
+# | 192.0.2.18/28    |
+# |                  |
+# | H3               |
+# +------------------+
+
+lib_dir=$(dirname $0)/../../../net/forwarding
+
+ALL_TESTS="
+	port_vid_map_rif
+	rif_port_vid_map
+"
+
+NUM_NETIFS=6
+source $lib_dir/lib.sh
+source $lib_dir/tc_common.sh
+source $lib_dir/devlink_lib.sh
+
+h1_create()
+{
+	simple_if_init $h1
+	vlan_create $h1 10 v$h1 192.0.2.1/28
+
+	ip route add 192.0.2.16/28 vrf v$h1 nexthop via 192.0.2.2
+}
+
+h1_destroy()
+{
+	ip route del 192.0.2.16/28 vrf v$h1 nexthop via 192.0.2.2
+
+	vlan_destroy $h1 10
+	simple_if_fini $h1
+}
+
+h2_create()
+{
+	simple_if_init $h2
+	vlan_create $h2 10 v$h2 192.0.2.3/28
+}
+
+h2_destroy()
+{
+	vlan_destroy $h2 10
+	simple_if_fini $h2
+}
+
+h3_create()
+{
+	simple_if_init $h3
+	vlan_create $h3 20 v$h3 192.0.2.18/28
+
+	ip route add 192.0.2.0/28 vrf v$h3 nexthop via 192.0.2.17
+}
+
+h3_destroy()
+{
+	ip route del 192.0.2.0/28 vrf v$h3 nexthop via 192.0.2.17
+
+	vlan_destroy $h3 20
+	simple_if_fini $h3
+}
+
+switch_create()
+{
+	ip link set dev $swp1 up
+	tc qdisc add dev $swp1 clsact
+
+	ip link add dev br0 type bridge mcast_snooping 0
+
+	# By default, a link-local address is generated when netdevice becomes
+	# up. Adding an address to the bridge will cause creating a RIF for it.
+	# Prevent generating link-local address to be able to control when the
+	# RIF is added.
+	sysctl_set net.ipv6.conf.br0.addr_gen_mode 1
+	ip link set dev br0 up
+
+	ip link set dev $swp2 up
+	vlan_create $swp2 10
+	ip link set dev $swp2.10 master br0
+
+	ip link set dev $swp3 up
+	vlan_create $swp3 20 "" 192.0.2.17/28
+
+	# Replace neighbor to avoid 1 packet which is forwarded in software due
+	# to "unresolved neigh".
+	ip neigh replace dev $swp3.20 192.0.2.18 lladdr $(mac_get $h3.20)
+}
+
+switch_destroy()
+{
+	vlan_destroy $swp3 20
+	ip link set dev $swp3 down
+
+	ip link set dev $swp2.10 nomaster
+	vlan_destroy $swp2 10
+	ip link set dev $swp2 down
+
+	ip link set dev br0 down
+	sysctl_restore net.ipv6.conf.br0.addr_gen_mode
+	ip link del dev br0
+
+	tc qdisc del dev $swp1 clsact
+	ip link set dev $swp1 down
+}
+
+setup_prepare()
+{
+	h1=${NETIFS[p1]}
+	swp1=${NETIFS[p2]}
+
+	swp2=${NETIFS[p3]}
+	h2=${NETIFS[p4]}
+
+	swp3=${NETIFS[p5]}
+	h3=${NETIFS[p6]}
+
+	vrf_prepare
+	forwarding_enable
+
+	h1_create
+	h2_create
+	h3_create
+
+	switch_create
+}
+
+cleanup()
+{
+	pre_cleanup
+
+	switch_destroy
+
+	h3_destroy
+	h2_destroy
+	h1_destroy
+
+	forwarding_restore
+	vrf_cleanup
+}
+
+bridge_rif_add()
+{
+	rifs_occ_t0=$(devlink_resource_occ_get rifs)
+	__addr_add_del br0 add 192.0.2.2/28
+	rifs_occ_t1=$(devlink_resource_occ_get rifs)
+
+	expected_rifs=$((rifs_occ_t0 + 1))
+
+	[[ $expected_rifs -eq $rifs_occ_t1 ]]
+	check_err $? "Expected $expected_rifs RIFs, $rifs_occ_t1 are used"
+
+	sleep 1
+}
+
+bridge_rif_del()
+{
+	__addr_add_del br0 del 192.0.2.2/28
+}
+
+port_vid_map_rif()
+{
+	RET=0
+
+	# First add {port, VID}->FID for swp1.10, then add a RIF and verify that
+	# packets get the correct VID after routing.
+	vlan_create $swp1 10
+	ip link set dev $swp1.10 master br0
+	bridge_rif_add
+
+	# Replace neighbor to avoid 1 packet which is forwarded in software due
+	# to "unresolved neigh".
+	ip neigh replace dev br0 192.0.2.1 lladdr $(mac_get $h1.10)
+
+	# The hardware matches on the first ethertype which is not VLAN,
+	# so the protocol should be IP.
+	tc filter add dev $swp1 egress protocol ip pref 1 handle 101 \
+		flower skip_sw dst_ip 192.0.2.1 action pass
+
+	ping_do $h1.10 192.0.2.18
+	check_err $? "Ping failed"
+
+	tc_check_at_least_x_packets "dev $swp1 egress" 101 10
+	check_err $? "Packets were not routed in hardware"
+
+	log_test "Add RIF for existing {port, VID}->FID mapping"
+
+	tc filter del dev $swp1 egress
+
+	bridge_rif_del
+	ip link set dev $swp1.10 nomaster
+	vlan_destroy $swp1 10
+}
+
+rif_port_vid_map()
+{
+	RET=0
+
+	# First add an address to the bridge, which will create a RIF on top of
+	# it, then add a new {port, VID}->FID mapping and verify that packets
+	# get the correct VID after routing.
+	bridge_rif_add
+	vlan_create $swp1 10
+	ip link set dev $swp1.10 master br0
+
+	# Replace neighbor to avoid 1 packet which is forwarded in software due
+	# to "unresolved neigh".
+	ip neigh replace dev br0 192.0.2.1 lladdr $(mac_get $h1.10)
+
+	# The hardware matches on the first ethertype which is not VLAN,
+	# so the protocol should be IP.
+	tc filter add dev $swp1 egress protocol ip pref 1 handle 101 \
+		flower skip_sw dst_ip 192.0.2.1 action pass
+
+	ping_do $h1.10 192.0.2.18
+	check_err $? "Ping failed"
+
+	tc_check_at_least_x_packets "dev $swp1 egress" 101 10
+	check_err $? "Packets were not routed in hardware"
+
+	log_test "Add {port, VID}->FID mapping for FID with a RIF"
+
+	tc filter del dev $swp1 egress
+
+	ip link set dev $swp1.10 nomaster
+	vlan_destroy $swp1 10
+	bridge_rif_del
+}
+
+trap cleanup EXIT
+
+setup_prepare
+setup_wait
+
+tests_run
+
+exit $EXIT_STATUS