net: bridge: switchdev: include local flag in FDB notifications

As explained in bugfix commit 6ab4c3117a ("net: bridge: don't notify
switchdev for local FDB addresses") as well as in this discussion:
https://lore.kernel.org/netdev/20210117193009.io3nungdwuzmo5f7@skbuf/

the switchdev notifiers for FDB entries managed to have a zero-day bug,
which was that drivers would not know what to do with local FDB entries,
because they were not told that they are local. The bug fix was to
simply not notify them of those addresses.

Let us now add the 'is_local' bit to bridge FDB entries, and make all
drivers ignore these entries by their own choice.

Co-developed-by: Tobias Waldekranz <tobias@waldekranz.com>
Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c

@@ -2098,7 +2098,7 @@ static void dpaa2_switch_event_work(struct work_struct *work)
 
 	switch (switchdev_work->event) {
 	case SWITCHDEV_FDB_ADD_TO_DEVICE:
-		if (!fdb_info->added_by_user)
+		if (!fdb_info->added_by_user || fdb_info->is_local)
 			break;
 		if (is_unicast_ether_addr(fdb_info->addr))
 			err = dpaa2_switch_port_fdb_add_uc(netdev_priv(dev),
@@ -2113,7 +2113,7 @@ static void dpaa2_switch_event_work(struct work_struct *work)
 					 &fdb_info->info, NULL);
 		break;
 	case SWITCHDEV_FDB_DEL_TO_DEVICE:
-		if (!fdb_info->added_by_user)
+		if (!fdb_info->added_by_user || fdb_info->is_local)
 			break;
 		if (is_unicast_ether_addr(fdb_info->addr))
 			dpaa2_switch_port_fdb_del_uc(netdev_priv(dev), fdb_info->addr);

drivers/net/ethernet/marvell/prestera/prestera_switchdev.c

@@ -798,7 +798,7 @@ static void prestera_fdb_event_work(struct work_struct *work)
 	switch (swdev_work->event) {
 	case SWITCHDEV_FDB_ADD_TO_DEVICE:
 		fdb_info = &swdev_work->fdb_info;
-		if (!fdb_info->added_by_user)
+		if (!fdb_info->added_by_user || fdb_info->is_local)
 			break;
 
 		err = prestera_port_fdb_set(port, fdb_info, true);

drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c

@@ -2916,7 +2916,8 @@ mlxsw_sp_switchdev_bridge_nve_fdb_event(struct mlxsw_sp_switchdev_event_work *
 		return;
 
 	if (switchdev_work->event == SWITCHDEV_FDB_ADD_TO_DEVICE &&
-	    !switchdev_work->fdb_info.added_by_user)
+	    (!switchdev_work->fdb_info.added_by_user ||
+	     switchdev_work->fdb_info.is_local))
 		return;
 
 	if (!netif_running(dev))
@@ -2971,7 +2972,7 @@ static void mlxsw_sp_switchdev_bridge_fdb_event_work(struct work_struct *work)
 	switch (switchdev_work->event) {
 	case SWITCHDEV_FDB_ADD_TO_DEVICE:
 		fdb_info = &switchdev_work->fdb_info;
-		if (!fdb_info->added_by_user)
+		if (!fdb_info->added_by_user || fdb_info->is_local)
 			break;
 		err = mlxsw_sp_port_fdb_set(mlxsw_sp_port, fdb_info, true);
 		if (err)

drivers/net/ethernet/rocker/rocker_main.c

@@ -2736,7 +2736,7 @@ static void rocker_switchdev_event_work(struct work_struct *work)
 	switch (switchdev_work->event) {
 	case SWITCHDEV_FDB_ADD_TO_DEVICE:
 		fdb_info = &switchdev_work->fdb_info;
-		if (!fdb_info->added_by_user)
+		if (!fdb_info->added_by_user || fdb_info->is_local)
 			break;
 		err = rocker_world_port_fdb_add(rocker_port, fdb_info);
 		if (err) {
@@ -2747,7 +2747,7 @@ static void rocker_switchdev_event_work(struct work_struct *work)
 		break;
 	case SWITCHDEV_FDB_DEL_TO_DEVICE:
 		fdb_info = &switchdev_work->fdb_info;
-		if (!fdb_info->added_by_user)
+		if (!fdb_info->added_by_user || fdb_info->is_local)
 			break;
 		err = rocker_world_port_fdb_del(rocker_port, fdb_info);
 		if (err)

drivers/net/ethernet/ti/am65-cpsw-switchdev.c

@@ -385,7 +385,7 @@ static void am65_cpsw_switchdev_event_work(struct work_struct *work)
 			   fdb->addr, fdb->vid, fdb->added_by_user,
 			   fdb->offloaded, port_id);
 
-		if (!fdb->added_by_user)
+		if (!fdb->added_by_user || fdb->is_local)
 			break;
 		if (memcmp(port->slave.mac_addr, (u8 *)fdb->addr, ETH_ALEN) == 0)
 			port_id = HOST_PORT_NUM;
@@ -401,7 +401,7 @@ static void am65_cpsw_switchdev_event_work(struct work_struct *work)
 			   fdb->addr, fdb->vid, fdb->added_by_user,
 			   fdb->offloaded, port_id);
 
-		if (!fdb->added_by_user)
+		if (!fdb->added_by_user || fdb->is_local)
 			break;
 		if (memcmp(port->slave.mac_addr, (u8 *)fdb->addr, ETH_ALEN) == 0)
 			port_id = HOST_PORT_NUM;

drivers/net/ethernet/ti/cpsw_switchdev.c

@@ -395,7 +395,7 @@ static void cpsw_switchdev_event_work(struct work_struct *work)
 			fdb->addr, fdb->vid, fdb->added_by_user,
 			fdb->offloaded, port);
 
-		if (!fdb->added_by_user)
+		if (!fdb->added_by_user || fdb->is_local)
 			break;
 		if (memcmp(priv->mac_addr, (u8 *)fdb->addr, ETH_ALEN) == 0)
 			port = HOST_PORT_NUM;
@@ -411,7 +411,7 @@ static void cpsw_switchdev_event_work(struct work_struct *work)
 			fdb->addr, fdb->vid, fdb->added_by_user,
 			fdb->offloaded, port);
 
-		if (!fdb->added_by_user)
+		if (!fdb->added_by_user || fdb->is_local)
 			break;
 		if (memcmp(priv->mac_addr, (u8 *)fdb->addr, ETH_ALEN) == 0)
 			port = HOST_PORT_NUM;

include/net/switchdev.h

@@ -209,6 +209,7 @@ struct switchdev_notifier_fdb_info {
 	const unsigned char *addr;
 	u16 vid;
 	u8 added_by_user:1,
+	   is_local:1,
 	   offloaded:1;
 };
 

net/bridge/br_switchdev.c

@@ -114,13 +114,12 @@ br_switchdev_fdb_notify(const struct net_bridge_fdb_entry *fdb, int type)
 		.addr = fdb->key.addr.addr,
 		.vid = fdb->key.vlan_id,
 		.added_by_user = test_bit(BR_FDB_ADDED_BY_USER, &fdb->flags),
+		.is_local = test_bit(BR_FDB_LOCAL, &fdb->flags),
 		.offloaded = test_bit(BR_FDB_OFFLOADED, &fdb->flags),
 	};
 
 	if (!fdb->dst)
 		return;
-	if (test_bit(BR_FDB_LOCAL, &fdb->flags))
-		return;
 
 	switch (type) {
 	case RTM_DELNEIGH:

net/dsa/slave.c

@@ -2329,7 +2329,7 @@ static int dsa_slave_switchdev_event(struct notifier_block *unused,
 		fdb_info = ptr;
 
 		if (dsa_slave_dev_check(dev)) {
-			if (!fdb_info->added_by_user)
+			if (!fdb_info->added_by_user || fdb_info->is_local)
 				return NOTIFY_OK;
 
 			dp = dsa_slave_to_port(dev);