diff mbox series

[net-next,2/2] net: bridge: switchdev: include local flag in FDB notifications

Message ID 20210414151540.1808871-2-olteanv@gmail.com
State Superseded
Headers show
Series [net-next,1/2] net: bridge: switchdev: refactor br_switchdev_fdb_notify | expand

Commit Message

Vladimir Oltean April 14, 2021, 3:15 p.m. UTC 
From: Vladimir Oltean <vladimir.oltean@nxp.com>

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>
---
 drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c        | 4 ++--
 drivers/net/ethernet/marvell/prestera/prestera_switchdev.c | 2 +-
 drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c   | 5 +++--
 drivers/net/ethernet/rocker/rocker_main.c                  | 4 ++--
 drivers/net/ethernet/ti/am65-cpsw-switchdev.c              | 4 ++--
 drivers/net/ethernet/ti/cpsw_switchdev.c                   | 4 ++--
 include/net/switchdev.h                                    | 1 +
 net/bridge/br_switchdev.c                                  | 3 +--
 net/dsa/slave.c                                            | 2 +-
 9 files changed, 15 insertions(+), 14 deletions(-)

Comments

Vladimir Oltean April 14, 2021, 4:05 p.m. UTC | #1 
On Wed, Apr 14, 2021 at 05:58:44PM +0200, Andrew Lunn wrote:
> > Let us now add the 'is_local' bit to bridge FDB entries, and make all
> > drivers ignore these entries by their own choice.
> 
> Hi Vladimir
> 
> This goes to the question about the missing cover letter. Why should
> drivers get to ignore them, rather than the core? It feels like there
> should be another patch in the series, where a driver does not
> actually ignore them, but does something?

Hi Andrew,

Bridge fdb entries with the is_local flag are entries which are
terminated locally and not forwarded. Switchdev drivers might want to be
notified of these addresses so they can trap them (otherwise, if they
don't program these entries to hardware, there is no guarantee that they
will do the right thing with these entries, and they won't be, let's
say, flooded). Of course, ideally none of the switchdev drivers should
ignore them, but having access to the is_local bit is the bare minimum
change that should be done in the bridge layer, before this is even
possible.

These 2 changes are actually part of a larger group of changes that
together form the "RX filtering for DSA" series. I haven't had a lot of
success with that, so I thought a better approach would be to take it
step by step. DSA will need to be notified of local FDB entries. For
now, it ignores them like everybody else. This is supposed to be a
non-functional patch series because I don't want to spam every switchdev
maintainer with 15+ DSA RX filtering patches.
Andrew Lunn April 14, 2021, 4:38 p.m. UTC | #2 
On Wed, Apr 14, 2021 at 07:05:10PM +0300, Vladimir Oltean wrote:
> On Wed, Apr 14, 2021 at 05:58:44PM +0200, Andrew Lunn wrote:
> > > Let us now add the 'is_local' bit to bridge FDB entries, and make all
> > > drivers ignore these entries by their own choice.
> > 
> > Hi Vladimir
> > 
> > This goes to the question about the missing cover letter. Why should
> > drivers get to ignore them, rather than the core? It feels like there
> > should be another patch in the series, where a driver does not
> > actually ignore them, but does something?
> 
> Hi Andrew,
> 
> Bridge fdb entries with the is_local flag are entries which are
> terminated locally and not forwarded. Switchdev drivers might want to be
> notified of these addresses so they can trap them (otherwise, if they
> don't program these entries to hardware, there is no guarantee that they
> will do the right thing with these entries, and they won't be, let's
> say, flooded). Of course, ideally none of the switchdev drivers should
> ignore them, but having access to the is_local bit is the bare minimum
> change that should be done in the bridge layer, before this is even
> possible.
> 
> These 2 changes are actually part of a larger group of changes that
> together form the "RX filtering for DSA" series. I haven't had a lot of
> success with that, so I thought a better approach would be to take it
> step by step. DSA will need to be notified of local FDB entries. For
> now, it ignores them like everybody else. This is supposed to be a
> non-functional patch series because I don't want to spam every switchdev
> maintainer with 15+ DSA RX filtering patches.

This is the sort of information which goes into 0/2. It explains the
big picture 'Why' of the change.

    Andrew
diff mbox series

Patch

diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c b/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c
index 80efc8116963..d7c0e11b16f7 100644
--- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c
+++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c
@@ -1832,7 +1832,7 @@  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),
@@ -1847,7 +1847,7 @@  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 995e0e16f295..6e348d2222a9 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);