net: bridge: Handle changes in VLAN_FLAG_BRIDGE_BINDING

When bridge binding is enabled on a VLAN netdevice, its link state should
track bridge ports that are members of the corresponding VLAN. This works
for newly-added netdevices. However toggling the option does not have the
effect of enabling or disabling the behavior as appropriate.

In this patch, react to bridge_binding toggles on VLAN uppers.

Signed-off-by: Petr Machata <[email protected]>
Reviewed-by: Ido Schimmel <[email protected]>
Acked-by: Nikolay Aleksandrov <[email protected]>
Link: https://patch.msgid.link/90a8ca8aea4d81378b29d75d9e562433e0d5c7ff.1734540770.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <[email protected]>

Author: pmachata

net/bridge/br.c

@@ -51,6 +51,13 @@ static int br_device_event(struct notifier_block *unused, unsigned long event, v
 		}
 	}
 
+	if (is_vlan_dev(dev)) {
+		struct net_device *real_dev = vlan_dev_real_dev(dev);
+
+		if (netif_is_bridge_master(real_dev))
+			br_vlan_vlan_upper_event(real_dev, dev, event);
+	}
+
 	/* not a port of a bridge */
 	p = br_port_get_rtnl(dev);
 	if (!p)

net/bridge/br_private.h

@@ -1571,6 +1571,9 @@ void br_vlan_get_stats(const struct net_bridge_vlan *v,
 void br_vlan_port_event(struct net_bridge_port *p, unsigned long event);
 int br_vlan_bridge_event(struct net_device *dev, unsigned long event,
 			 void *ptr);
+void br_vlan_vlan_upper_event(struct net_device *br_dev,
+			      struct net_device *vlan_dev,
+			      unsigned long event);
 int br_vlan_rtnl_init(void);
 void br_vlan_rtnl_uninit(void);
 void br_vlan_notify(const struct net_bridge *br,
@@ -1802,6 +1805,12 @@ static inline int br_vlan_bridge_event(struct net_device *dev,
 	return 0;
 }
 
+static inline void br_vlan_vlan_upper_event(struct net_device *br_dev,
+					    struct net_device *vlan_dev,
+					    unsigned long event)
+{
+}
+
 static inline int br_vlan_rtnl_init(void)
 {
 	return 0;

net/bridge/br_vlan.c

@@ -1772,6 +1772,30 @@ int br_vlan_bridge_event(struct net_device *dev, unsigned long event, void *ptr)
 	return ret;
 }
 
+void br_vlan_vlan_upper_event(struct net_device *br_dev,
+			      struct net_device *vlan_dev,
+			      unsigned long event)
+{
+	struct vlan_dev_priv *vlan = vlan_dev_priv(vlan_dev);
+	struct net_bridge *br = netdev_priv(br_dev);
+	bool bridge_binding;
+
+	switch (event) {
+	case NETDEV_CHANGE:
+	case NETDEV_UP:
+		break;
+	default:
+		return;
+	}
+
+	bridge_binding = vlan->flags & VLAN_FLAG_BRIDGE_BINDING;
+	br_vlan_toggle_bridge_binding(br_dev, bridge_binding);
+	if (bridge_binding)
+		br_vlan_set_vlan_dev_state(br, vlan_dev);
+	else if (!bridge_binding && netif_carrier_ok(br_dev))
+		netif_carrier_on(vlan_dev);
+}
+
 /* Must be protected by RTNL. */
 void br_vlan_port_event(struct net_bridge_port *p, unsigned long event)
 {