bridge: Handle changes in VLAN_FLAG_BRIDGE_BINDING

Currently, the BROPT_VLAN_BRIDGE_BINDING bridge option is only toggled when VLAN devices are added on top of a bridge or removed from it. Extract the toggling of the option to a function so that it could be invoked by a subsequent patch when the state of an upper VLAN device changes.

Signed-off-by Petr Machata <[email protected]>

Reviewed-by Ido Schimmel <[email protected]>

---
 net/bridge/br_vlan.c | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

net/bridge/br_vlan.c +13 -1

index 89f51ea4cabe..b728b71e693f 100644
@@ -1664,6 +1664,18 @@ static void br_vlan_set_all_vlan_dev_state(struct net_bridge_port *p)
 	}
 }
 
+static void br_vlan_toggle_bridge_binding(struct net_device *br_dev,
+					  bool enable)
+{
+	struct net_bridge *br = netdev_priv(br_dev);
+
+	if (enable)
+		br_opt_toggle(br, BROPT_VLAN_BRIDGE_BINDING, true);
+	else
+		br_opt_toggle(br, BROPT_VLAN_BRIDGE_BINDING,
+			      br_vlan_has_upper_bind_vlan_dev(br_dev));
+}
+
 static void br_vlan_upper_change(struct net_device *dev,
 				 struct net_device *upper_dev,
 				 bool linking)

@@ -1673,13 +1685,9 @@ static void br_vlan_upper_change(struct net_device *dev,
 	if (!br_vlan_is_bind_vlan_dev(upper_dev))
 		return;
 
-	if (linking) {
+	br_vlan_toggle_bridge_binding(dev, linking);

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]>

---
 net/bridge/br.c         |  7 +++++++
 net/bridge/br_private.h |  9 +++++++++
 net/bridge/br_vlan.c    | 24 ++++++++++++++++++++++++
 3 files changed, 40 insertions(+)

net/bridge/br.c +7 -0

index 2cab878e0a39..183fcb362f9e 100644
@@ -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 +9 -0

index 9853cfbb9d14..29d6ec45cf41 100644
@@ -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 +17 -0

index b728b71e693f..d9a69ec9affe 100644
@@ -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;

Alongside the helper ip_link_set_up(), one to set the link down will be useful as well. Add a helper to determine the link state as well, ip_link_is_up(), and use it to short-circuit any changes if the state is already the desired one.

Furthermore, add a helper bridge_vlan_add().

Signed-off-by Petr Machata <[email protected]>

Reviewed-by Ido Schimmel <[email protected]>

---
CC: Shuah Khan <[email protected]>
CC: [email protected]

---
 tools/testing/selftests/net/lib.sh | 31 ++++++++++++++++++++++++++++--
 1 file changed, 29 insertions(+), 2 deletions(-)

tools/testing/selftests/net/lib.sh +23 -2

index 2cd5c743b2d9..0bd9a038a1f0 100644
@@ -477,12 +477,33 @@ ip_link_set_addr()
 	defer ip link set dev "$name" address "$old_addr"
 }
 
+ip_link_is_up()
+{
+	local name=$1; shift
+
+	local state=$(ip -j link show "$name" |
+		      jq -r '(.[].flags[] | select(. == "UP")) // "DOWN"')
+	[[ $state == "UP" ]]
+}
+
 ip_link_set_up()
 {
 	local name=$1; shift
 
-	ip link set dev "$name" up
-	defer ip link set dev "$name" down
+	if ! ip_link_is_up "$name"; then
+		ip link set dev "$name" up
+		defer ip link set dev "$name" down
+	fi
+}
+
+ip_link_set_down()
+{
+	local name=$1; shift
+
+	if ip_link_is_up "$name"; then
+		ip link set dev "$name" down
+		defer ip link set dev "$name" up
+	fi
 }
 
 ip_addr_add()

Add a test that exercises bridge binding.

Signed-off-by Petr Machata <[email protected]>

Reviewed-by Ido Schimmel <[email protected]>

---
CC: Shuah Khan <[email protected]>
CC: [email protected]

---
 tools/testing/selftests/net/Makefile          |   1 +
 .../selftests/net/vlan_bridge_binding.sh      | 256 ++++++++++++++++++
 2 files changed, 257 insertions(+)
 create mode 100755 tools/testing/selftests/net/vlan_bridge_binding.sh