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

As explained in bugfix commit 6ab4c3117aec ("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>

9 files changed, 15 insertions, 14 deletions

diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c b/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c
index 5250d51d783c..05de37c3b64c 100644
--- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c
+++ b/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);
diff --git a/drivers/net/ethernet/marvell/prestera/prestera_switchdev.c b/drivers/net/ethernet/marvell/prestera/prestera_switchdev.c
index 49e052273f30..cb564890a3dc 100644
--- a/drivers/net/ethernet/marvell/prestera/prestera_switchdev.c
+++ b/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);
diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c
index c1f05c17557d..eeccd586e781 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c
+++ b/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)
diff --git a/drivers/net/ethernet/rocker/rocker_main.c b/drivers/net/ethernet/rocker/rocker_main.c
index 3473d296b2e2..a46633606cae 100644
--- a/drivers/net/ethernet/rocker/rocker_main.c
+++ b/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)
diff --git a/drivers/net/ethernet/ti/am65-cpsw-switchdev.c b/drivers/net/ethernet/ti/am65-cpsw-switchdev.c
index d93ffd8a08b0..23cfb91e9c4d 100644
--- a/drivers/net/ethernet/ti/am65-cpsw-switchdev.c
+++ b/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;
diff --git a/drivers/net/ethernet/ti/cpsw_switchdev.c b/drivers/net/ethernet/ti/cpsw_switchdev.c
index a72bb570756f..05a64fb7a04f 100644
--- a/drivers/net/ethernet/ti/cpsw_switchdev.c
+++ b/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;
diff --git a/include/net/switchdev.h b/include/net/switchdev.h
index 8c3218177136..f1a5a9a3634d 100644
--- a/include/net/switchdev.h
+++ b/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;
 };
 
diff --git a/net/bridge/br_switchdev.c b/net/bridge/br_switchdev.c
index c390f84adea2..a5e601e41cb9 100644
--- a/net/bridge/br_switchdev.c
+++ b/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:
diff --git a/net/dsa/slave.c b/net/dsa/slave.c
index 9300cb66e500..3ae67202fda2 100644
--- a/net/dsa/slave.c
+++ b/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);