1 files changed, 93 insertions, 0 deletions
diff --git a/tools/testing/selftests/net/macvlan_mcast_shared_mac.sh b/tools/testing/selftests/net/macvlan_mcast_shared_mac.sh
new file mode 100755
index 000000000000..ff5b89347247
--- /dev/null
+++ b/tools/testing/selftests/net/macvlan_mcast_shared_mac.sh
@@ -0,0 +1,93 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# Test multicast delivery to macvlan bridge ports when the source MAC
+# matches the macvlan's own MAC address (e.g., VRRP virtual MAC shared
+# across multiple hosts).
+#
+# Topology:
+#
+#   NS_SRC                          NS_BRIDGE
+#   veth_src (SHARED_MAC) <----->  veth_dst
+#                                     |
+#                                     +-- macvlan0 (bridge mode, SHARED_MAC)
+#
+# A multicast packet sent from NS_SRC with source MAC equal to
+# macvlan0's MAC must still be delivered to macvlan0.
+
+source lib.sh
+
+SHARED_MAC="00:00:5e:00:01:01"
+MCAST_ADDR="239.0.0.1"
+
+setup() {
+	setup_ns NS_SRC NS_BRIDGE
+
+	ip -net "${NS_BRIDGE}" link add veth_dst type veth \
+		peer name veth_src netns "${NS_SRC}"
+
+	ip -net "${NS_SRC}" link set veth_src address "${SHARED_MAC}"
+	ip -net "${NS_SRC}" link set veth_src up
+	ip -net "${NS_SRC}" addr add 192.168.1.1/24 dev veth_src
+
+	ip -net "${NS_BRIDGE}" link set veth_dst up
+
+	ip -net "${NS_BRIDGE}" link add macvlan0 link veth_dst \
+		type macvlan mode bridge
+	ip -net "${NS_BRIDGE}" link set macvlan0 address "${SHARED_MAC}"
+	ip -net "${NS_BRIDGE}" link set macvlan0 up
+	ip -net "${NS_BRIDGE}" addr add 192.168.1.2/24 dev macvlan0
+
+	# Accept all multicast so the mc_filter passes for any group.
+	ip -net "${NS_BRIDGE}" link set macvlan0 allmulticast on
+}
+
+cleanup() {
+	rm -f "${CAPFILE}" "${CAPOUT}"
+	cleanup_ns "${NS_SRC}" "${NS_BRIDGE}"
+}
+
+test_macvlan_mcast_shared_mac() {
+	CAPFILE=$(mktemp)
+	CAPOUT=$(mktemp)
+
+	echo "Testing multicast delivery to macvlan with shared source MAC"
+
+	# Listen for one ICMP packet on macvlan0.
+	timeout 5s ip netns exec "${NS_BRIDGE}" \
+		tcpdump -i macvlan0 -c 1 -w "${CAPFILE}" icmp &> "${CAPOUT}" &
+	local pid=$!
+	if ! slowwait 1 grep -qs "listening" "${CAPOUT}"; then
+		echo "[FAIL] tcpdump did not start listening"
+		return "${ksft_fail}"
+	fi
+
+	# Send multicast ping from NS_SRC; source MAC equals macvlan0's MAC.
+	ip netns exec "${NS_SRC}" \
+		ping -W 0.1 -c 3 -I veth_src "${MCAST_ADDR}" &> /dev/null
+
+	wait "${pid}"
+
+	local count
+	count=$(tcpdump -r "${CAPFILE}" 2>/dev/null | wc -l)
+	if [[ "${count}" -ge 1 ]]; then
+		echo "[ OK ]"
+		return "${ksft_pass}"
+	else
+		echo "[FAIL] expected at least 1 ICMP packet on macvlan0," \
+			"got ${count}"
+		return "${ksft_fail}"
+	fi
+}
+
+if [ ! -x "$(command -v tcpdump)" ]; then
+	echo "SKIP: Could not run test without tcpdump tool"
+	exit "${ksft_skip}"
+fi
+
+trap cleanup EXIT
+
+setup
+test_macvlan_mcast_shared_mac
+
+exit $?