selftests: router_bridge: Add remastering tests

Add two tests to deslave a port from and reenslave to a bridge. This should
retain the ability of the system to forward traffic, but on an offloading
driver that is sensitive to ordering of operations, it might not.

The first test does this configuration in a way that relies on
vlan_default_pvid to assign the PVID. The second test disables that
autoconfiguration and configures PVID by hand in a separate step.
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Danielle Ratson <danieller@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -20,6 +20,9 @@
 # +---------------------------------------------------------------------------+
 
 ALL_TESTS="
+	ping_ipv4
+	ping_ipv6
+	config_remaster
 	ping_ipv4
 	ping_ipv6
 	config_remove_pvid
@@ -28,6 +31,9 @@ ALL_TESTS="
 	config_add_pvid
 	ping_ipv4
 	ping_ipv6
+	config_late_pvid
+	ping_ipv4
+	ping_ipv6
 "
 NUM_NETIFS=4
 source lib.sh
@@ -86,6 +92,15 @@ router_destroy()
 	ip link del dev br1
 }
 
+config_remaster()
+{
+	log_info "Remaster bridge slave"
+
+	ip link set dev $swp1 nomaster
+	sleep 2
+	ip link set dev $swp1 master br1
+}
+
 config_remove_pvid()
 {
 	log_info "Remove PVID from the bridge"
@@ -102,6 +117,17 @@ config_add_pvid()
 	sleep 2
 }
 
+config_late_pvid()
+{
+	log_info "Add bridge PVID after enslaving port"
+
+	ip link set dev $swp1 nomaster
+	ip link set dev br1 type bridge vlan_default_pvid 0
+	sleep 2
+	ip link set dev $swp1 master br1
+	ip link set dev br1 type bridge vlan_default_pvid 1
+}
+
 setup_prepare()
 {
 	h1=${NETIFS[p1]}