[RFC PATCH v2 net-next 10/16] net: dsa: replay VLANs installed on port when joining the bridge

[Vladimir Oltean <olteanv@gmail.com>]

From: Vladimir Oltean <vladimir.oltean@nxp.com>

Currently this simple setup:

ip link add br0 type bridge vlan_filtering 1
ip link add bond0 type bond
ip link set bond0 master br0
ip link set swp0 master bond0

will not work because the bridge has created the PVID in br_add_if ->
nbp_vlan_init, and it has notified switchdev of the existence of VLAN 1,
but that was too early, since swp0 was not yet a lower of bond0, so it
had no reason to act upon that notification.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
---
 include/linux/if_bridge.h | 10 ++++++
 net/bridge/br_vlan.c      | 71 +++++++++++++++++++++++++++++++++++++++
 net/dsa/port.c            |  6 ++++
 3 files changed, 87 insertions(+)

diff --git a/include/linux/if_bridge.h b/include/linux/if_bridge.h
index 89596134e88f..ea176c508c0d 100644
--- a/include/linux/if_bridge.h
+++ b/include/linux/if_bridge.h
@@ -111,6 +111,8 @@ int br_vlan_get_pvid_rcu(const struct net_device *dev, u16 *p_pvid);
 int br_vlan_get_proto(const struct net_device *dev, u16 *p_proto);
 int br_vlan_get_info(const struct net_device *dev, u16 vid,
 		     struct bridge_vlan_info *p_vinfo);
+int br_vlan_replay(struct net_device *br_dev, struct net_device *dev,
+		   struct notifier_block *nb, struct netlink_ext_ack *extack);
 #else
 static inline bool br_vlan_enabled(const struct net_device *dev)
 {
@@ -137,6 +139,14 @@ static inline int br_vlan_get_info(const struct net_device *dev, u16 vid,
 {
 	return -EINVAL;
 }
+
+static inline int br_vlan_replay(struct net_device *br_dev,
+				 struct net_device *dev,
+				 struct notifier_block *nb,
+				 struct netlink_ext_ack *extack)
+{
+	return -EINVAL;
+}
 #endif
 
 #if IS_ENABLED(CONFIG_BRIDGE)
diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index 8829f621b8ec..45a4eac1b217 100644
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -1751,6 +1751,77 @@ void br_vlan_notify(const struct net_bridge *br,
 	kfree_skb(skb);
 }
 
+static int br_vlan_replay_one(struct notifier_block *nb,
+			      struct net_device *dev,
+			      struct switchdev_obj_port_vlan *vlan,
+			      struct netlink_ext_ack *extack)
+{
+	struct switchdev_notifier_port_obj_info obj_info = {
+		.info = {
+			.dev = dev,
+			.extack = extack,
+		},
+		.obj = &vlan->obj,
+	};
+	int err;
+
+	err = nb->notifier_call(nb, SWITCHDEV_PORT_OBJ_ADD, &obj_info);
+	return notifier_to_errno(err);
+}
+
+int br_vlan_replay(struct net_device *br_dev, struct net_device *dev,
+		   struct notifier_block *nb, struct netlink_ext_ack *extack)
+{
+	struct net_bridge_vlan_group *vg;
+	struct net_bridge_vlan *v;
+	struct net_bridge_port *p;
+	struct net_bridge *br;
+	int err = 0;
+	u16 pvid;
+
+	ASSERT_RTNL();
+
+	if (!netif_is_bridge_master(br_dev))
+		return -EINVAL;
+
+	if (!netif_is_bridge_master(dev) && !netif_is_bridge_port(dev))
+		return -EINVAL;
+
+	if (netif_is_bridge_master(dev)) {
+		br = netdev_priv(dev);
+		vg = br_vlan_group(br);
+		p = NULL;
+	} else {
+		p = br_port_get_rtnl(dev);
+		if (WARN_ON(!p))
+			return -EINVAL;
+		vg = nbp_vlan_group(p);
+		br = p->br;
+	}
+
+	if (!vg)
+		return 0;
+
+	pvid = br_get_pvid(vg);
+
+	list_for_each_entry(v, &vg->vlan_list, vlist) {
+		struct switchdev_obj_port_vlan vlan = {
+			.obj.orig_dev = dev,
+			.obj.id = SWITCHDEV_OBJ_ID_PORT_VLAN,
+			.flags = br_vlan_flags(v, pvid),
+			.vid = v->vid,
+		};
+
+		if (!br_vlan_should_use(v))
+			continue;
+
+		br_vlan_replay_one(nb, dev, &vlan, extack);
+		if (err)
+			return err;
+	}
+
+	return err;
+}
 /* check if v_curr can enter a range ending in range_end */
 bool br_vlan_can_enter_range(const struct net_bridge_vlan *v_curr,
 			     const struct net_bridge_vlan *range_end)
diff --git a/net/dsa/port.c b/net/dsa/port.c
index 9850051071f2..6c3c357ac409 100644
--- a/net/dsa/port.c
+++ b/net/dsa/port.c
@@ -209,6 +209,12 @@ static int dsa_port_switchdev_sync(struct dsa_port *dp,
 	if (err && err != -EOPNOTSUPP)
 		return err;
 
+	err = br_vlan_replay(br, brport_dev,
+			     &dsa_slave_switchdev_blocking_notifier,
+			     extack);
+	if (err && err != -EOPNOTSUPP)
+		return err;
+
 	return 0;
 }
 
-- 
2.25.1