selftests: forwarding: test for bridge mcast traffic after report and leave

This test is split in two, the first part checks if a report creates a
corresponding mdb entry and if traffic is properly forwarded to it, and
the second part checks if the mdb entry is deleted after a leave and
if traffic is *not* forwarded to it. Since the mcast querier is enabled
we should see standard mcast snooping bridge behaviour.

Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -0,0 +1,152 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+ALL_TESTS="reportleave_test"
+NUM_NETIFS=4
+CHECK_TC="yes"
+TEST_GROUP="239.10.10.10"
+TEST_GROUP_MAC="01:00:5e:0a:0a:0a"
+source lib.sh
+
+h1_create()
+{
+	simple_if_init $h1 192.0.2.1/24 2001:db8:1::1/64
+}
+
+h1_destroy()
+{
+	simple_if_fini $h1 192.0.2.1/24 2001:db8:1::1/64
+}
+
+h2_create()
+{
+	simple_if_init $h2 192.0.2.2/24 2001:db8:1::2/64
+}
+
+h2_destroy()
+{
+	simple_if_fini $h2 192.0.2.2/24 2001:db8:1::2/64
+}
+
+switch_create()
+{
+	ip link add dev br0 type bridge mcast_snooping 1 mcast_querier 1
+
+	ip link set dev $swp1 master br0
+	ip link set dev $swp2 master br0
+
+	ip link set dev br0 up
+	ip link set dev $swp1 up
+	ip link set dev $swp2 up
+}
+
+switch_destroy()
+{
+	ip link set dev $swp2 down
+	ip link set dev $swp1 down
+
+	ip link del dev br0
+}
+
+setup_prepare()
+{
+	h1=${NETIFS[p1]}
+	swp1=${NETIFS[p2]}
+
+	swp2=${NETIFS[p3]}
+	h2=${NETIFS[p4]}
+
+	vrf_prepare
+
+	h1_create
+	h2_create
+
+	switch_create
+}
+
+cleanup()
+{
+	pre_cleanup
+
+	switch_destroy
+
+	# Always cleanup the mcast group
+	ip address del dev $h2 $TEST_GROUP/32 2>&1 1>/dev/null
+
+	h2_destroy
+	h1_destroy
+
+	vrf_cleanup
+}
+
+# return 0 if the packet wasn't seen on host2_if or 1 if it was
+mcast_packet_test()
+{
+	local mac=$1
+	local ip=$2
+	local host1_if=$3
+	local host2_if=$4
+	local seen=0
+
+	# Add an ACL on `host2_if` which will tell us whether the packet
+	# was received by it or not.
+	tc qdisc add dev $host2_if ingress
+	tc filter add dev $host2_if ingress protocol ip pref 1 handle 101 \
+		flower dst_mac $mac action drop
+
+	$MZ $host1_if -c 1 -p 64 -b $mac -B $ip -t udp "dp=4096,sp=2048" -q
+	sleep 1
+
+	tc -j -s filter show dev $host2_if ingress \
+		| jq -e ".[] | select(.options.handle == 101) \
+		| select(.options.actions[0].stats.packets == 1)" &> /dev/null
+	if [[ $? -eq 0 ]]; then
+		seen=1
+	fi
+
+	tc filter del dev $host2_if ingress protocol ip pref 1 handle 101 flower
+	tc qdisc del dev $host2_if ingress
+
+	return $seen
+}
+
+reportleave_test()
+{
+	RET=0
+	ip address add dev $h2 $TEST_GROUP/32 autojoin
+	check_err $? "Could not join $TEST_GROUP"
+
+	sleep 5
+	bridge mdb show dev br0 | grep $TEST_GROUP 1>/dev/null
+	check_err $? "Report didn't create mdb entry for $TEST_GROUP"
+
+	mcast_packet_test $TEST_GROUP_MAC $TEST_GROUP $h1 $h2
+	check_fail $? "Traffic to $TEST_GROUP wasn't forwarded"
+
+	log_test "IGMP report $TEST_GROUP"
+
+	RET=0
+	bridge mdb show dev br0 | grep $TEST_GROUP 1>/dev/null
+	check_err $? "mdb entry for $TEST_GROUP is missing"
+
+	ip address del dev $h2 $TEST_GROUP/32
+	check_err $? "Could not leave $TEST_GROUP"
+
+	sleep 5
+	bridge mdb show dev br0 | grep $TEST_GROUP 1>/dev/null
+	check_fail $? "Leave didn't delete mdb entry for $TEST_GROUP"
+
+	mcast_packet_test $TEST_GROUP_MAC $TEST_GROUP $h1 $h2
+	check_err $? "Traffic to $TEST_GROUP was forwarded without mdb entry"
+
+	log_test "IGMP leave $TEST_GROUP"
+}
+
+trap cleanup EXIT
+
+setup_prepare
+setup_wait
+
+tests_run
+
+exit $EXIT_STATUS