selftests: mlxsw: Add a test for VxLAN flooding

The device stores flood records in a singly linked list where each
record stores up to three IPv4 addresses of remote VTEPs. The test
verifies that packets are correctly flooded in various cases such as
deletion of a record in the middle of the list.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# Test VxLAN flooding. The device stores flood records in a singly linked list
+# where each record stores up to three IPv4 addresses of remote VTEPs. The test
+# verifies that packets are correctly flooded in various cases such as deletion
+# of a record in the middle of the list.
+#
+# +--------------------+
+# | H1 (vrf)           |
+# |    + $h1           |
+# |    | 203.0.113.1/24|
+# +----|---------------+
+#      |
+# +----|----------------------------------------------------------------------+
+# | SW |                                                                      |
+# | +--|--------------------------------------------------------------------+ |
+# | |  + $swp1                   BR0 (802.1d)                               | |
+# | |                                                                       | |
+# | |  + vxlan0 (vxlan)                                                     | |
+# | |    local 198.51.100.1                                                 | |
+# | |    remote 198.51.100.{2..13}                                          | |
+# | |    id 10 dstport 4789                                                 | |
+# | +-----------------------------------------------------------------------+ |
+# |                                                                           |
+# |  198.51.100.0/24 via 192.0.2.2                                            |
+# |                                                                           |
+# |    + $rp1                                                                 |
+# |    | 192.0.2.1/24                                                         |
+# +----|----------------------------------------------------------------------+
+#      |
+# +----|--------------------------------------------------------+
+# |    |                                               R2 (vrf) |
+# |    + $rp2                                                   |
+# |      192.0.2.2/24                                           |
+# |                                                             |
+# +-------------------------------------------------------------+
+
+lib_dir=$(dirname $0)/../../../net/forwarding
+
+ALL_TESTS="flooding_test"
+NUM_NETIFS=4
+source $lib_dir/tc_common.sh
+source $lib_dir/lib.sh
+
+h1_create()
+{
+	simple_if_init $h1 203.0.113.1/24
+}
+
+h1_destroy()
+{
+	simple_if_fini $h1 203.0.113.1/24
+}
+
+switch_create()
+{
+	# Make sure the bridge uses the MAC address of the local port and
+	# not that of the VxLAN's device
+	ip link add dev br0 type bridge mcast_snooping 0
+	ip link set dev br0 address $(mac_get $swp1)
+
+	ip link add name vxlan0 type vxlan id 10 nolearning noudpcsum \
+		ttl 20 tos inherit local 198.51.100.1 dstport 4789
+
+	ip address add 198.51.100.1/32 dev lo
+
+	ip link set dev $swp1 master br0
+	ip link set dev vxlan0 master br0
+
+	ip link set dev br0 up
+	ip link set dev $swp1 up
+	ip link set dev vxlan0 up
+}
+
+switch_destroy()
+{
+	ip link set dev vxlan0 down
+	ip link set dev $swp1 down
+	ip link set dev br0 down
+
+	ip link set dev vxlan0 nomaster
+	ip link set dev $swp1 nomaster
+
+	ip address del 198.51.100.1/32 dev lo
+
+	ip link del dev vxlan0
+
+	ip link del dev br0
+}
+
+router1_create()
+{
+	# This router is in the default VRF, where the VxLAN device is
+	# performing the L3 lookup
+	ip link set dev $rp1 up
+	ip address add 192.0.2.1/24 dev $rp1
+	ip route add 198.51.100.0/24 via 192.0.2.2
+}
+
+router1_destroy()
+{
+	ip route del 198.51.100.0/24 via 192.0.2.2
+	ip address del 192.0.2.1/24 dev $rp1
+	ip link set dev $rp1 down
+}
+
+router2_create()
+{
+	# This router is not in the default VRF, so use simple_if_init()
+	simple_if_init $rp2 192.0.2.2/24
+}
+
+router2_destroy()
+{
+	simple_if_fini $rp2 192.0.2.2/24
+}
+
+setup_prepare()
+{
+	h1=${NETIFS[p1]}
+	swp1=${NETIFS[p2]}
+
+	rp1=${NETIFS[p3]}
+	rp2=${NETIFS[p4]}
+
+	vrf_prepare
+
+	h1_create
+
+	switch_create
+
+	router1_create
+	router2_create
+
+	forwarding_enable
+}
+
+cleanup()
+{
+	pre_cleanup
+
+	forwarding_restore
+
+	router2_destroy
+	router1_destroy
+
+	switch_destroy
+
+	h1_destroy
+
+	vrf_cleanup
+}
+
+flooding_remotes_add()
+{
+	local num_remotes=$1
+	local lsb
+	local i
+
+	for i in $(eval echo {1..$num_remotes}); do
+		lsb=$((i + 1))
+
+		bridge fdb append 00:00:00:00:00:00 dev vxlan0 self \
+			dst 198.51.100.$lsb
+	done
+}
+
+flooding_filters_add()
+{
+	local num_remotes=$1
+	local lsb
+	local i
+
+	tc qdisc add dev $rp2 clsact
+
+	for i in $(eval echo {1..$num_remotes}); do
+		lsb=$((i + 1))
+
+		tc filter add dev $rp2 ingress protocol ip pref $i handle $i \
+			flower ip_proto udp dst_ip 198.51.100.$lsb \
+			dst_port 4789 skip_sw action drop
+	done
+}
+
+flooding_filters_del()
+{
+	local num_remotes=$1
+	local i
+
+	for i in $(eval echo {1..$num_remotes}); do
+		tc filter del dev $rp2 ingress protocol ip pref $i \
+			handle $i flower
+	done
+
+	tc qdisc del dev $rp2 clsact
+}
+
+flooding_check_packets()
+{
+	local packets=("$@")
+	local num_remotes=${#packets[@]}
+	local i
+
+	for i in $(eval echo {1..$num_remotes}); do
+		tc_check_packets "dev $rp2 ingress" $i ${packets[i - 1]}
+		check_err $? "remote $i - did not get expected number of packets"
+	done
+}
+
+flooding_test()
+{
+	# Use 12 remote VTEPs that will be stored in 4 records. The array
+	# 'packets' will store how many packets are expected to be received
+	# by each remote VTEP at each stage of the test
+	declare -a packets=(1 1 1 1 1 1 1 1 1 1 1 1)
+	local num_remotes=12
+
+	RET=0
+
+	# Add FDB entries for remote VTEPs and corresponding tc filters on the
+	# ingress of the nexthop router. These filters will count how many
+	# packets were flooded to each remote VTEP
+	flooding_remotes_add $num_remotes
+	flooding_filters_add $num_remotes
+
+	# Send one packet and make sure it is flooded to all the remote VTEPs
+	$MZ $h1 -q -p 64 -b de:ad:be:ef:13:37 -t ip -c 1
+	flooding_check_packets "${packets[@]}"
+	log_test "flood after 1 packet"
+
+	# Delete the third record which corresponds to VTEPs with LSB 8..10
+	# and check that packet is flooded correctly when we remove a record
+	# from the middle of the list
+	RET=0
+
+	packets=(2 2 2 2 2 2 1 1 1 2 2 2)
+	bridge fdb del 00:00:00:00:00:00 dev vxlan0 self dst 198.51.100.8
+	bridge fdb del 00:00:00:00:00:00 dev vxlan0 self dst 198.51.100.9
+	bridge fdb del 00:00:00:00:00:00 dev vxlan0 self dst 198.51.100.10
+
+	$MZ $h1 -q -p 64 -b de:ad:be:ef:13:37 -t ip -c 1
+	flooding_check_packets "${packets[@]}"
+	log_test "flood after 2 packets"
+
+	# Delete the first record and make sure the packet is flooded correctly
+	RET=0
+
+	packets=(2 2 2 3 3 3 1 1 1 3 3 3)
+	bridge fdb del 00:00:00:00:00:00 dev vxlan0 self dst 198.51.100.2
+	bridge fdb del 00:00:00:00:00:00 dev vxlan0 self dst 198.51.100.3
+	bridge fdb del 00:00:00:00:00:00 dev vxlan0 self dst 198.51.100.4
+
+	$MZ $h1 -q -p 64 -b de:ad:be:ef:13:37 -t ip -c 1
+	flooding_check_packets "${packets[@]}"
+	log_test "flood after 3 packets"
+
+	# Delete the last record and make sure the packet is flooded correctly
+	RET=0
+
+	packets=(2 2 2 4 4 4 1 1 1 3 3 3)
+	bridge fdb del 00:00:00:00:00:00 dev vxlan0 self dst 198.51.100.11
+	bridge fdb del 00:00:00:00:00:00 dev vxlan0 self dst 198.51.100.12
+	bridge fdb del 00:00:00:00:00:00 dev vxlan0 self dst 198.51.100.13
+
+	$MZ $h1 -q -p 64 -b de:ad:be:ef:13:37 -t ip -c 1
+	flooding_check_packets "${packets[@]}"
+	log_test "flood after 4 packets"
+
+	# Delete the last record, one entry at a time and make sure single
+	# entries are correctly removed
+	RET=0
+
+	packets=(2 2 2 4 5 5 1 1 1 3 3 3)
+	bridge fdb del 00:00:00:00:00:00 dev vxlan0 self dst 198.51.100.5
+
+	$MZ $h1 -q -p 64 -b de:ad:be:ef:13:37 -t ip -c 1
+	flooding_check_packets "${packets[@]}"
+	log_test "flood after 5 packets"
+
+	RET=0
+
+	packets=(2 2 2 4 5 6 1 1 1 3 3 3)
+	bridge fdb del 00:00:00:00:00:00 dev vxlan0 self dst 198.51.100.6
+
+	$MZ $h1 -q -p 64 -b de:ad:be:ef:13:37 -t ip -c 1
+	flooding_check_packets "${packets[@]}"
+	log_test "flood after 6 packets"
+
+	RET=0
+
+	packets=(2 2 2 4 5 6 1 1 1 3 3 3)
+	bridge fdb del 00:00:00:00:00:00 dev vxlan0 self dst 198.51.100.7
+
+	$MZ $h1 -q -p 64 -b de:ad:be:ef:13:37 -t ip -c 1
+	flooding_check_packets "${packets[@]}"
+	log_test "flood after 7 packets"
+
+	flooding_filters_del $num_remotes
+}
+
+trap cleanup EXIT
+
+setup_prepare
+setup_wait
+
+tests_run
+
+exit $EXIT_STATUS