[PATCH v5 net-next 12/14] bridge: No DEV_PATH_BR_VLAN_UNTAG_HW for dsa foreign

Eric Woudstra
2025-02-04T21:16:21Z

In network setup as below:

fastpath bypass
.----------------------------------------.
/ \
| IP - forwarding |
| / \ v
| / wan ...
| /
| |
| |
| brlan.1
| |
| +-------------------------------+
| | vlan 1 |
| | |
| | brlan (vlan-filtering) |
| | +---------------+
| | | DSA-SWITCH |
| | vlan 1 | |
| | to | |
| | untagged 1 vlan 1 |
| +---------------+---------------+
. / \
----->wlan1 lan0
. .
. ^
^ vlan 1 tagged packets
untagged packets

br_vlan_fill_forward_path_mode() sets DEV_PATH_BR_VLAN_UNTAG_HW when
filling in from brlan.1 towards wlan1. But it should be set to
DEV_PATH_BR_VLAN_UNTAG in this case. Using BR_VLFLAG_ADDED_BY_SWITCHDEV
is not correct. The dsa switchdev adds it as a foreign port.

The same problem for all foreignly added dsa vlans on the bridge.

First add the vlan, trying only native devices.
If this fails, we know this may be a vlan from a foreign device.

Use BR_VLFLAG_TAGGING_BY_SWITCHDEV to make sure DEV_PATH_BR_VLAN_UNTAG_HW
is set only when there if no foreign device involved.

Signed-off-by: Eric Woudstra <ericwouds@gmail.com>
---
include/net/switchdev.h | 1 +
net/bridge/br_private.h | 10 ++++++++++
net/bridge/br_switchdev.c | 15 +++++++++++++++
net/bridge/br_vlan.c | 7 ++++++-
net/switchdev/switchdev.c | 2 +-
5 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/include/net/switchdev.h b/include/net/switchdev.h
index 8346b0d29542..ee500706496b 100644
--- a/include/net/switchdev.h
+++ b/include/net/switchdev.h
@@ -15,6 +15,7 @@
#define SWITCHDEV_F_NO_RECURSE BIT(0)
#define SWITCHDEV_F_SKIP_EOPNOTSUPP BIT(1)
#define SWITCHDEV_F_DEFER BIT(2)
+#define SWITCHDEV_F_NO_FOREIGN BIT(3)

enum switchdev_attr_id {
SWITCHDEV_ATTR_ID_UNDEFINED,
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index a0b950390a16..b950db453d8d 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -180,6 +180,7 @@ enum {
BR_VLFLAG_MCAST_ENABLED = BIT(2),
BR_VLFLAG_GLOBAL_MCAST_ENABLED = BIT(3),
BR_VLFLAG_NEIGH_SUPPRESS_ENABLED = BIT(4),
+ BR_VLFLAG_TAGGING_BY_SWITCHDEV = BIT(5),
};

/**
@@ -2184,6 +2185,8 @@ void br_switchdev_mdb_notify(struct net_device *dev,
int type);
int br_switchdev_port_vlan_add(struct net_device *dev, u16 vid, u16 flags,
bool changed, struct netlink_ext_ack *extack);
+int br_switchdev_port_vlan_no_foreign_add(struct net_device *dev, u16 vid, u16 flags,
+ bool changed, struct netlink_ext_ack *extack);
int br_switchdev_port_vlan_del(struct net_device *dev, u16 vid);
void br_switchdev_init(struct net_bridge *br);

@@ -2267,6 +2270,13 @@ static inline int br_switchdev_port_vlan_add(struct net_device *dev, u16 vid,
return -EOPNOTSUPP;
}

+static inline int br_switchdev_port_vlan_no_foreign_add(struct net_device *dev, u16 vid,
+ u16 flags, bool changed,
+ struct netlink_ext_ack *extack)
+{
+ return -EOPNOTSUPP;
+}
+
static inline int br_switchdev_port_vlan_del(struct net_device *dev, u16 vid)
{
return -EOPNOTSUPP;
diff --git a/net/bridge/br_switchdev.c b/net/bridge/br_switchdev.c
index 7b41ee8740cb..efa7a055b8f9 100644
--- a/net/bridge/br_switchdev.c
+++ b/net/bridge/br_switchdev.c
@@ -187,6 +187,21 @@ int br_switchdev_port_vlan_add(struct net_device *dev, u16 vid, u16 flags,
return switchdev_port_obj_add(dev, &v.obj, extack);
}

+int br_switchdev_port_vlan_no_foreign_add(struct net_device *dev, u16 vid, u16 flags,
+ bool changed, struct netlink_ext_ack *extack)
+{
+ struct switchdev_obj_port_vlan v = {
+ .obj.orig_dev = dev,
+ .obj.id = SWITCHDEV_OBJ_ID_PORT_VLAN,
+ .obj.flags = SWITCHDEV_F_NO_FOREIGN,
+ .flags = flags,
+ .vid = vid,
+ .changed = changed,
+ };
+
+ return switchdev_port_obj_add(dev, &v.obj, extack);
+}
+
int br_switchdev_port_vlan_del(struct net_device *dev, u16 vid)
{
struct switchdev_obj_port_vlan v = {
diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index 07dae3655c26..3e50adaf8e1b 100644
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -109,6 +109,11 @@ static int __vlan_vid_add(struct net_device *dev, struct net_bridge *br,
/* Try switchdev op first. In case it is not supported, fallback to
* 8021q add.
*/
+ err = br_switchdev_port_vlan_no_foreign_add(dev, v->vid, flags, false, extack);
+ if (err != -EOPNOTSUPP) {
+ v->priv_flags |= BR_VLFLAG_ADDED_BY_SWITCHDEV | BR_VLFLAG_TAGGING_BY_SWITCHDEV;
+ return err;
+ }
err = br_switchdev_port_vlan_add(dev, v->vid, flags, false, extack);
if (err == -EOPNOTSUPP)
return vlan_vid_add(dev, br->vlan_proto, v->vid);
@@ -1491,7 +1496,7 @@ int br_vlan_fill_forward_path_mode(struct net_bridge *br,

if (path->bridge.vlan_mode == DEV_PATH_BR_VLAN_TAG)
path->bridge.vlan_mode = DEV_PATH_BR_VLAN_KEEP;
- else if (v->priv_flags & BR_VLFLAG_ADDED_BY_SWITCHDEV)
+ else if (v->priv_flags & BR_VLFLAG_TAGGING_BY_SWITCHDEV)
path->bridge.vlan_mode = DEV_PATH_BR_VLAN_UNTAG_HW;
else
path->bridge.vlan_mode = DEV_PATH_BR_VLAN_UNTAG;
diff --git a/net/switchdev/switchdev.c b/net/switchdev/switchdev.c
index 6488ead9e464..c48f66643e99 100644
--- a/net/switchdev/switchdev.c
+++ b/net/switchdev/switchdev.c
@@ -749,7 +749,7 @@ static int __switchdev_handle_port_obj_add(struct net_device *dev,
/* Event is neither on a bridge nor a LAG. Check whether it is on an
* interface that is in a bridge with us.
*/
- if (!foreign_dev_check_cb)
+ if (!foreign_dev_check_cb || port_obj_info->obj->flags & SWITCHDEV_F_NO_FOREIGN)
return err;

br = netdev_master_upper_dev_get(dev);
--
2.47.1