Linux Ethernet Bridging - May 2018 - [Bridge] [PATCH net-next 0/7] net: bridge: Notify about bridge VLANs

In commit 946a11e7408e ("mlxsw: spectrum_span: Allow bridge for gretap
mirror"), mlxsw got support for offloading mirror-to-gretap such that
the underlay packet path involves a bridge. In that case, the offload is
also influenced by PVID setting of said bridge. However, changes to VLAN
configuration of the bridge itself do not generate switchdev
notifications, so there's no mechanism to prod mlxsw to update the
offload when these settings change.

In this patchset, the problem is resolved by distributing the switchdev
notification SWITCHDEV_OBJ_ID_PORT_VLAN also for configuration changes
on bridge VLANs. Since stacked devices distribute the notification to
lower devices, such event eventually reaches the driver, which can
determine whether it's a bridge or port VLAN by inspecting orig_dev.

To keep things consistent, the newly-distributed notifications observe
the same protocol as the existing ones: dual prepare/commit, with
-EOPNOTSUPP indicating lack of support, even though there's currently
nothing to prepare for and nothing to support. Correspondingly, all
switchdev drivers have been updated to return -EOPNOTSUPP for bridge
VLAN notifications.

In patch #1, the code to send notifications for adding and deleting is
factored out into two named functions.

In patches #2-#5, respectively for mlxsw, rocker, DSA and DPAA2 ethsw,
the new notifications (which are not enabled yet) are ignored to
maintain the current behavior.

In patch #6, the notification is actually enabled.

In patch #7, mlxsw is changed to update offloads of mirror-to-gre also
for bridge-related notifications.

Petr Machata (7):
  net: bridge: Extract boilerplate around switchdev_port_obj_*()
  mlxsw: spectrum_switchdev: Ignore bridge VLAN events
  rocker: rocker_main: Ignore bridge VLAN events
  dsa: port: Ignore bridge VLAN events
  staging: fsl-dpaa2: ethsw: Ignore bridge VLAN events
  net: bridge: Notify about bridge VLANs
  mlxsw: spectrum_switchdev: Schedule respin during trans prepare

 .../ethernet/mellanox/mlxsw/spectrum_switchdev.c   |  8 ++-
 drivers/net/ethernet/rocker/rocker_main.c          |  6 +++
 drivers/staging/fsl-dpaa2/ethsw/ethsw.c            |  6 +++
 net/bridge/br_vlan.c                               | 58 ++++++++++++++--------
 net/dsa/port.c                                     |  6 +++
 5 files changed, 62 insertions(+), 22 deletions(-)

-- 
2.4.11

A call to switchdev_port_obj_add() or switchdev_port_obj_del() involves
initializing a struct switchdev_obj_port_vlan, a piece of code that
repeats on each call site almost verbatim. While in the current codebase
there is just one duplicated add call, the follow-up patches add more of
both add and del calls.

Thus to remove the duplication, extract the repetition into named
functions and reuse.

Signed-off-by: Petr Machata <petrm at mellanox.com>
---
 net/bridge/br_vlan.c | 44 +++++++++++++++++++++++---------------------
 1 file changed, 23 insertions(+), 21 deletions(-)

diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index dc832c09..a75fe930 100644
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -79,8 +79,7 @@ static bool __vlan_add_flags(struct net_bridge_vlan *v, u16
flags)
 	return ret || !!(old_flags ^ v->flags);
 }
 
-static int __vlan_vid_add(struct net_device *dev, struct net_bridge *br,
-			  u16 vid, u16 flags)
+static int br_switchdev_port_obj_add(struct net_device *dev, u16 vid, u16
flags)
 {
 	struct switchdev_obj_port_vlan v = {
 		.obj.orig_dev = dev,
@@ -89,12 +88,29 @@ static int __vlan_vid_add(struct net_device *dev, struct
net_bridge *br,
 		.vid_begin = vid,
 		.vid_end = vid,
 	};
-	int err;
 
+	return switchdev_port_obj_add(dev, &v.obj);
+}
+
+static int br_switchdev_port_obj_del(struct net_device *dev, u16 vid)
+{
+	struct switchdev_obj_port_vlan v = {
+		.obj.orig_dev = dev,
+		.obj.id = SWITCHDEV_OBJ_ID_PORT_VLAN,
+		.vid_begin = vid,
+		.vid_end = vid,
+	};
+
+	return switchdev_port_obj_del(dev, &v.obj);
+}
+
+static int __vlan_vid_add(struct net_device *dev, struct net_bridge *br,
+			  u16 vid, u16 flags)
+{
 	/* Try switchdev op first. In case it is not supported, fallback to
 	 * 8021q add.
 	 */
-	err = switchdev_port_obj_add(dev, &v.obj);
+	int err = br_switchdev_port_obj_add(dev, vid, flags);
 	if (err == -EOPNOTSUPP)
 		return vlan_vid_add(dev, br->vlan_proto, vid);
 	return err;
@@ -130,18 +146,11 @@ static void __vlan_del_list(struct net_bridge_vlan *v)
 static int __vlan_vid_del(struct net_device *dev, struct net_bridge *br,
 			  u16 vid)
 {
-	struct switchdev_obj_port_vlan v = {
-		.obj.orig_dev = dev,
-		.obj.id = SWITCHDEV_OBJ_ID_PORT_VLAN,
-		.vid_begin = vid,
-		.vid_end = vid,
-	};
-	int err;
-
 	/* Try switchdev op first. In case it is not supported, fallback to
 	 * 8021q del.
 	 */
-	err = switchdev_port_obj_del(dev, &v.obj);
+	int err = br_switchdev_port_obj_del(dev, vid);
+
 	if (err == -EOPNOTSUPP) {
 		vlan_vid_del(dev, br->vlan_proto, vid);
 		return 0;
@@ -1053,13 +1062,6 @@ int nbp_vlan_init(struct net_bridge_port *p)
 int nbp_vlan_add(struct net_bridge_port *port, u16 vid, u16 flags,
 		 bool *changed)
 {
-	struct switchdev_obj_port_vlan v = {
-		.obj.orig_dev = port->dev,
-		.obj.id = SWITCHDEV_OBJ_ID_PORT_VLAN,
-		.flags = flags,
-		.vid_begin = vid,
-		.vid_end = vid,
-	};
 	struct net_bridge_vlan *vlan;
 	int ret;
 
@@ -1069,7 +1071,7 @@ int nbp_vlan_add(struct net_bridge_port *port, u16 vid,
u16 flags,
 	vlan = br_vlan_find(nbp_vlan_group(port), vid);
 	if (vlan) {
 		/* Pass the flags to the hardware bridge */
-		ret = switchdev_port_obj_add(port->dev, &v.obj);
+		ret = br_switchdev_port_obj_add(port->dev, vid, flags);
 		if (ret && ret != -EOPNOTSUPP)
 			return ret;
 		*changed = __vlan_add_flags(vlan, flags);
-- 
2.4.11

Ignore VLAN events where the orig_dev is the bridge device itself.

Signed-off-by: Petr Machata <petrm at mellanox.com>
Reviewed-by: Ido Schimmel <idosch at mellanox.com>
---
 drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c
b/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c
index 8c9cf8e..cbc8fab 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c
@@ -1144,6 +1144,9 @@ static int mlxsw_sp_port_vlans_add(struct mlxsw_sp_port
*mlxsw_sp_port,
 	struct mlxsw_sp_bridge_port *bridge_port;
 	u16 vid;
 
+	if (netif_is_bridge_master(orig_dev))
+		return -EOPNOTSUPP;
+
 	if (switchdev_trans_ph_prepare(trans))
 		return 0;
 
@@ -1741,6 +1744,9 @@ static int mlxsw_sp_port_vlans_del(struct mlxsw_sp_port
*mlxsw_sp_port,
 	struct mlxsw_sp_bridge_port *bridge_port;
 	u16 vid;
 
+	if (netif_is_bridge_master(orig_dev))
+		return -EOPNOTSUPP;
+
 	bridge_port = mlxsw_sp_bridge_port_find(mlxsw_sp->bridge, orig_dev);
 	if (WARN_ON(!bridge_port))
 		return -EINVAL;
-- 
2.4.11

Ignore VLAN events where the orig_dev is the bridge device itself.

Signed-off-by: Petr Machata <petrm at mellanox.com>
---
 drivers/net/ethernet/rocker/rocker_main.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/net/ethernet/rocker/rocker_main.c
b/drivers/net/ethernet/rocker/rocker_main.c
index e73e4fe..aeafdb9 100644
--- a/drivers/net/ethernet/rocker/rocker_main.c
+++ b/drivers/net/ethernet/rocker/rocker_main.c
@@ -1632,6 +1632,9 @@ rocker_world_port_obj_vlan_add(struct rocker_port
*rocker_port,
 {
 	struct rocker_world_ops *wops = rocker_port->rocker->wops;
 
+	if (netif_is_bridge_master(vlan->obj.orig_dev))
+		return -EOPNOTSUPP;
+
 	if (!wops->port_obj_vlan_add)
 		return -EOPNOTSUPP;
 
@@ -1647,6 +1650,9 @@ rocker_world_port_obj_vlan_del(struct rocker_port
*rocker_port,
 {
 	struct rocker_world_ops *wops = rocker_port->rocker->wops;
 
+	if (netif_is_bridge_master(vlan->obj.orig_dev))
+		return -EOPNOTSUPP;
+
 	if (!wops->port_obj_vlan_del)
 		return -EOPNOTSUPP;
 	return wops->port_obj_vlan_del(rocker_port, vlan);
-- 
2.4.11

Ignore VLAN events where the orig_dev is the bridge device itself.

Signed-off-by: Petr Machata <petrm at mellanox.com>
---
 net/dsa/port.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/net/dsa/port.c b/net/dsa/port.c
index 2413beb..ed05954 100644
--- a/net/dsa/port.c
+++ b/net/dsa/port.c
@@ -252,6 +252,9 @@ int dsa_port_vlan_add(struct dsa_port *dp,
 		.vlan = vlan,
 	};
 
+	if (netif_is_bridge_master(vlan->obj.orig_dev))
+		return -EOPNOTSUPP;
+
 	if (br_vlan_enabled(dp->bridge_dev))
 		return dsa_port_notify(dp, DSA_NOTIFIER_VLAN_ADD, &info);
 
@@ -267,6 +270,9 @@ int dsa_port_vlan_del(struct dsa_port *dp,
 		.vlan = vlan,
 	};
 
+	if (netif_is_bridge_master(vlan->obj.orig_dev))
+		return -EOPNOTSUPP;
+
 	if (br_vlan_enabled(dp->bridge_dev))
 		return dsa_port_notify(dp, DSA_NOTIFIER_VLAN_DEL, &info);
 
-- 
2.4.11

Ignore VLAN events where the orig_dev is the bridge device itself.

Signed-off-by: Petr Machata <petrm at mellanox.com>
---
 drivers/staging/fsl-dpaa2/ethsw/ethsw.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/staging/fsl-dpaa2/ethsw/ethsw.c
b/drivers/staging/fsl-dpaa2/ethsw/ethsw.c
index c723a04..a17dd29 100644
--- a/drivers/staging/fsl-dpaa2/ethsw/ethsw.c
+++ b/drivers/staging/fsl-dpaa2/ethsw/ethsw.c
@@ -719,6 +719,9 @@ static int port_vlans_add(struct net_device *netdev,
 	struct ethsw_port_priv *port_priv = netdev_priv(netdev);
 	int vid, err;
 
+	if (netif_is_bridge_master(vlan->obj.orig_dev))
+		return -EOPNOTSUPP;
+
 	if (switchdev_trans_ph_prepare(trans))
 		return 0;
 
@@ -873,6 +876,9 @@ static int port_vlans_del(struct net_device *netdev,
 	struct ethsw_port_priv *port_priv = netdev_priv(netdev);
 	int vid, err;
 
+	if (netif_is_bridge_master(vlan->obj.orig_dev))
+		return -EOPNOTSUPP;
+
 	for (vid = vlan->vid_begin; vid <= vlan->vid_end; vid++) {
 		err = ethsw_port_del_vlan(port_priv, vid);
 		if (err)
-- 
2.4.11

A driver might need to react to changes in settings of brentry VLANs.
Therefore send switchdev port notifications for these as well. Reuse
SWITCHDEV_OBJ_ID_PORT_VLAN for this purpose. Listeners should use
netif_is_bridge_master() on orig_dev to determine whether the
notification is about a bridge port or a bridge.

Signed-off-by: Petr Machata <petrm at mellanox.com>
---
 net/bridge/br_vlan.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index a75fe930..14c1b6c 100644
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -268,6 +268,10 @@ static int __vlan_add(struct net_bridge_vlan *v, u16 flags)
 			goto out_filt;
 		v->brvlan = masterv;
 		v->stats = masterv->stats;
+	} else {
+		err = br_switchdev_port_obj_add(dev, v->vid, flags);
+		if (err && err != -EOPNOTSUPP)
+			goto out;
 	}
 
 	/* Add the dev mac and count the vlan only if it's usable */
@@ -303,6 +307,8 @@ static int __vlan_add(struct net_bridge_vlan *v, u16 flags)
 			br_vlan_put_master(masterv);
 			v->brvlan = NULL;
 		}
+	} else {
+		br_switchdev_port_obj_del(dev, v->vid);
 	}
 
 	goto out;
@@ -328,6 +334,11 @@ static int __vlan_del(struct net_bridge_vlan *v)
 		err = __vlan_vid_del(p->dev, p->br, v->vid);
 		if (err)
 			goto out;
+	} else {
+		err = br_switchdev_port_obj_del(v->br->dev, v->vid);
+		if (err && err != -EOPNOTSUPP)
+			goto out;
+		err = 0;
 	}
 
 	if (br_vlan_should_use(v)) {
@@ -605,6 +616,9 @@ int br_vlan_add(struct net_bridge *br, u16 vid, u16 flags,
bool *changed)
 			vg->num_vlans++;
 			*changed = true;
 		}
+		ret = br_switchdev_port_obj_add(br->dev, vid, flags);
+		if (ret && ret != -EOPNOTSUPP)
+			return ret;
 		if (__vlan_add_flags(vlan, flags))
 			*changed = true;
 
-- 
2.4.11

Since there's no special support for the bridge events, the driver
returns -EOPNOTSUPP, and thus the commit never happens. Therefore
schedule respin during the prepare stage: there's no real difference one
way or another.

This fixes the problem that mirror-to-gretap offload wouldn't adapt to
changes in bridge vlan configuration right away and another notification
would have to arrive for mlxsw to catch up.

Signed-off-by: Petr Machata <petrm at mellanox.com>
Reviewed-by: Ido Schimmel <idosch at mellanox.com>
---
 drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c
b/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c
index cbc8fab..8a15ac4 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c
@@ -1697,7 +1697,7 @@ static int mlxsw_sp_port_obj_add(struct net_device *dev,
 		vlan = SWITCHDEV_OBJ_PORT_VLAN(obj);
 		err = mlxsw_sp_port_vlans_add(mlxsw_sp_port, vlan, trans);
 
-		if (switchdev_trans_ph_commit(trans)) {
+		if (switchdev_trans_ph_prepare(trans)) {
 			/* The event is emitted before the changes are actually
 			 * applied to the bridge. Therefore schedule the respin
 			 * call for later, so that the respin logic sees the
-- 
2.4.11

Hi Petr,

On 05/24/2018 08:09 AM, Petr Machata wrote:
> In commit 946a11e7408e ("mlxsw: spectrum_span: Allow bridge for gretap
> mirror"), mlxsw got support for offloading mirror-to-gretap such that
> the underlay packet path involves a bridge. In that case, the offload is
> also influenced by PVID setting of said bridge. However, changes to VLAN
> configuration of the bridge itself do not generate switchdev
> notifications, so there's no mechanism to prod mlxsw to update the
> offload when these settings change.
> 
> In this patchset, the problem is resolved by distributing the switchdev
> notification SWITCHDEV_OBJ_ID_PORT_VLAN also for configuration changes
> on bridge VLANs. Since stacked devices distribute the notification to
> lower devices, such event eventually reaches the driver, which can
> determine whether it's a bridge or port VLAN by inspecting orig_dev.
> 
> To keep things consistent, the newly-distributed notifications observe
> the same protocol as the existing ones: dual prepare/commit, with
> -EOPNOTSUPP indicating lack of support, even though there's currently
> nothing to prepare for and nothing to support. Correspondingly, all
> switchdev drivers have been updated to return -EOPNOTSUPP for bridge
> VLAN notifications.
You seem to have approached the bridge changes a little differently from
this series:

https://lists.linux-foundation.org/pipermail/bridge/2016-November/010112.html

Both have the same intent that by targeting the bridge device itself,
you can propagate that through switchdev to the switch drivers, and in
turn create configurations where for instance, you have:

- CPU/management port present in specific VLANs that is a subset or
superset of the VLANs configured on front-panel ports
- CPU/management port tagged/untagged in specific VLANs which can be a
different setting from the front-panel ports

One problem we have in DSA at the moment is that we always add the CPU
port to the VLANs configured to the front-panel port but we do this with
the same attributes as the front panel ports! For instance, if you add
Port 0 to VLAN1 untagged, the the CPU port also gets added to that
VLAN1, also untagged. As long as there is just one VLAN untagged, this
is not much of a problem. Now do this with another VLAN or another port,
and the CPU can no longer differentiate the traffic from which VLAN it
is coming from, no bueno.

I had specifically changed b53 to always add the CPU port as tagged,
because that would always allow for differentiating traffic, but I would
rather have the capability to configure that at the bridge layer, which
you series seem to allow.

For the record, here is what the first commit in the series intended to
let an user do:

The following happens now (assuming bridge master device is already
created):

bridge vlan add vid 2 dev port0 pvid untagged
	-> port0 (e.g: switch port 0) gets programmed
	-> CPU port gets programmed
bridge vlan add vid 2 dev br0 self
	-> CPU port gets programmed
bridge vlan add vid 2 dev port0
	-> port0 (switch port 0) gets programmed

Are these use cases possible with your series? It seems to me like it is
if we drop the netif_is_bridge_master() checks and resolve orig_dev as
being a hint for the CPU/management port.

Thanks for reading me :)
> 
> In patch #1, the code to send notifications for adding and deleting is
> factored out into two named functions.
> 
> In patches #2-#5, respectively for mlxsw, rocker, DSA and DPAA2 ethsw,
> the new notifications (which are not enabled yet) are ignored to
> maintain the current behavior.
> 
> In patch #6, the notification is actually enabled.
> 
> In patch #7, mlxsw is changed to update offloads of mirror-to-gre also
> for bridge-related notifications.
> 
> Petr Machata (7):
>   net: bridge: Extract boilerplate around switchdev_port_obj_*()
>   mlxsw: spectrum_switchdev: Ignore bridge VLAN events
>   rocker: rocker_main: Ignore bridge VLAN events
>   dsa: port: Ignore bridge VLAN events
>   staging: fsl-dpaa2: ethsw: Ignore bridge VLAN events
>   net: bridge: Notify about bridge VLANs
>   mlxsw: spectrum_switchdev: Schedule respin during trans prepare
> 
>  .../ethernet/mellanox/mlxsw/spectrum_switchdev.c   |  8 ++-
>  drivers/net/ethernet/rocker/rocker_main.c          |  6 +++
>  drivers/staging/fsl-dpaa2/ethsw/ethsw.c            |  6 +++
>  net/bridge/br_vlan.c                               | 58
++++++++++++++--------
>  net/dsa/port.c                                     |  6 +++
>  5 files changed, 62 insertions(+), 22 deletions(-)
> 

-- 
Florian

On 05/24/2018 08:09 AM, Petr Machata wrote:
> In commit 946a11e7408e ("mlxsw: spectrum_span: Allow bridge for gretap
> mirror"), mlxsw got support for offloading mirror-to-gretap such that
> the underlay packet path involves a bridge. In that case, the offload is
> also influenced by PVID setting of said bridge. However, changes to VLAN
> configuration of the bridge itself do not generate switchdev
> notifications, so there's no mechanism to prod mlxsw to update the
> offload when these settings change.
> 
> In this patchset, the problem is resolved by distributing the switchdev
> notification SWITCHDEV_OBJ_ID_PORT_VLAN also for configuration changes
> on bridge VLANs. Since stacked devices distribute the notification to
> lower devices, such event eventually reaches the driver, which can
> determine whether it's a bridge or port VLAN by inspecting orig_dev.
> 
> To keep things consistent, the newly-distributed notifications observe
> the same protocol as the existing ones: dual prepare/commit, with
> -EOPNOTSUPP indicating lack of support, even though there's currently
> nothing to prepare for and nothing to support. Correspondingly, all
> switchdev drivers have been updated to return -EOPNOTSUPP for bridge
> VLAN notifications.
This is great, see the other two emails about why I like it so much:

Reviewed-by: Florian Fainelli <f.fainelli at gmail.com>
Tested-by: Florian Fainelli <f.fainelli at gmail.com>

Thanks!
> 
> In patch #1, the code to send notifications for adding and deleting is
> factored out into two named functions.
> 
> In patches #2-#5, respectively for mlxsw, rocker, DSA and DPAA2 ethsw,
> the new notifications (which are not enabled yet) are ignored to
> maintain the current behavior.
> 
> In patch #6, the notification is actually enabled.
> 
> In patch #7, mlxsw is changed to update offloads of mirror-to-gre also
> for bridge-related notifications.
> 
> Petr Machata (7):
>   net: bridge: Extract boilerplate around switchdev_port_obj_*()
>   mlxsw: spectrum_switchdev: Ignore bridge VLAN events
>   rocker: rocker_main: Ignore bridge VLAN events
>   dsa: port: Ignore bridge VLAN events
>   staging: fsl-dpaa2: ethsw: Ignore bridge VLAN events
>   net: bridge: Notify about bridge VLANs
>   mlxsw: spectrum_switchdev: Schedule respin during trans prepare
> 
>  .../ethernet/mellanox/mlxsw/spectrum_switchdev.c   |  8 ++-
>  drivers/net/ethernet/rocker/rocker_main.c          |  6 +++
>  drivers/staging/fsl-dpaa2/ethsw/ethsw.c            |  6 +++
>  net/bridge/br_vlan.c                               | 58
++++++++++++++--------
>  net/dsa/port.c                                     |  6 +++
>  5 files changed, 62 insertions(+), 22 deletions(-)
> 
-- 
Florian