mlxsw: spectrum: Enable VxLAN enslavement to bridges

Enslavement of VxLAN devices to offloaded bridges was never forbidden by
mlxsw, but this patch makes sure the required configuration is performed
in order to allow VxLAN encapsulation and decapsulation to take place in
the device.

The patch handles both the case where a VxLAN device is enslaved to an
already offloaded bridge and the case where the first mlxsw port is
enslaved to a bridge that already has VxLAN device configured.

Invalid configurations are sanitized and an error string is returned via
extack.

Since encapsulation and decapsulation do not occur when the VxLAN device
is down, the driver makes sure to enable / disable these functionalities
based on NETDEV_PRE_UP and NETDEV_DOWN events.

Note that NETDEV_PRE_UP is used in favor of NETDEV_UP, as the former
allows to veto the operation, if necessary.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 104 insertions, 0 deletions

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
index 68079b16adfa..8a4983adae94 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
@@ -4587,6 +4587,41 @@ static void mlxsw_sp_port_ovs_leave(struct mlxsw_sp_port *mlxsw_sp_port)
 	mlxsw_sp_port_vp_mode_set(mlxsw_sp_port, false);
 }
 
+static bool mlxsw_sp_bridge_has_multiple_vxlans(struct net_device *br_dev)
+{
+	unsigned int num_vxlans = 0;
+	struct net_device *dev;
+	struct list_head *iter;
+
+	netdev_for_each_lower_dev(br_dev, dev, iter) {
+		if (netif_is_vxlan(dev))
+			num_vxlans++;
+	}
+
+	return num_vxlans > 1;
+}
+
+static bool mlxsw_sp_bridge_vxlan_is_valid(struct net_device *br_dev,
+					   struct netlink_ext_ack *extack)
+{
+	if (br_multicast_enabled(br_dev)) {
+		NL_SET_ERR_MSG_MOD(extack, "Multicast can not be enabled on a bridge with a VxLAN device");
+		return false;
+	}
+
+	if (br_vlan_enabled(br_dev)) {
+		NL_SET_ERR_MSG_MOD(extack, "VLAN filtering can not be enabled on a bridge with a VxLAN device");
+		return false;
+	}
+
+	if (mlxsw_sp_bridge_has_multiple_vxlans(br_dev)) {
+		NL_SET_ERR_MSG_MOD(extack, "Multiple VxLAN devices are not supported in a VLAN-unaware bridge");
+		return false;
+	}
+
+	return true;
+}
+
 static int mlxsw_sp_netdevice_port_upper_event(struct net_device *lower_dev,
 					       struct net_device *dev,
 					       unsigned long event, void *ptr)
@@ -4616,6 +4651,11 @@ static int mlxsw_sp_netdevice_port_upper_event(struct net_device *lower_dev,
 		}
 		if (!info->linking)
 			break;
+		if (netif_is_bridge_master(upper_dev) &&
+		    !mlxsw_sp_bridge_device_is_offloaded(mlxsw_sp, upper_dev) &&
+		    mlxsw_sp_bridge_has_vxlan(upper_dev) &&
+		    !mlxsw_sp_bridge_vxlan_is_valid(upper_dev, extack))
+			return -EOPNOTSUPP;
 		if (netdev_has_any_upper_dev(upper_dev) &&
 		    (!netif_is_bridge_master(upper_dev) ||
 		     !mlxsw_sp_bridge_device_is_offloaded(mlxsw_sp,
@@ -4773,6 +4813,11 @@ static int mlxsw_sp_netdevice_port_vlan_event(struct net_device *vlan_dev,
 		}
 		if (!info->linking)
 			break;
+		if (netif_is_bridge_master(upper_dev) &&
+		    !mlxsw_sp_bridge_device_is_offloaded(mlxsw_sp, upper_dev) &&
+		    mlxsw_sp_bridge_has_vxlan(upper_dev) &&
+		    !mlxsw_sp_bridge_vxlan_is_valid(upper_dev, extack))
+			return -EOPNOTSUPP;
 		if (netdev_has_any_upper_dev(upper_dev) &&
 		    (!netif_is_bridge_master(upper_dev) ||
 		     !mlxsw_sp_bridge_device_is_offloaded(mlxsw_sp,
@@ -4919,6 +4964,63 @@ static bool mlxsw_sp_is_vrf_event(unsigned long event, void *ptr)
 	return netif_is_l3_master(info->upper_dev);
 }
 
+static int mlxsw_sp_netdevice_vxlan_event(struct mlxsw_sp *mlxsw_sp,
+					  struct net_device *dev,
+					  unsigned long event, void *ptr)
+{
+	struct netdev_notifier_changeupper_info *cu_info;
+	struct netdev_notifier_info *info = ptr;
+	struct netlink_ext_ack *extack;
+	struct net_device *upper_dev;
+
+	extack = netdev_notifier_info_to_extack(info);
+
+	switch (event) {
+	case NETDEV_CHANGEUPPER:
+		cu_info = container_of(info,
+				       struct netdev_notifier_changeupper_info,
+				       info);
+		upper_dev = cu_info->upper_dev;
+		if (!netif_is_bridge_master(upper_dev))
+			return 0;
+		if (!mlxsw_sp_lower_get(upper_dev))
+			return 0;
+		if (!mlxsw_sp_bridge_vxlan_is_valid(upper_dev, extack))
+			return -EOPNOTSUPP;
+		if (cu_info->linking) {
+			if (!netif_running(dev))
+				return 0;
+			return mlxsw_sp_bridge_vxlan_join(mlxsw_sp, upper_dev,
+							  dev, extack);
+		} else {
+			mlxsw_sp_bridge_vxlan_leave(mlxsw_sp, upper_dev, dev);
+		}
+		break;
+	case NETDEV_PRE_UP:
+		upper_dev = netdev_master_upper_dev_get(dev);
+		if (!upper_dev)
+			return 0;
+		if (!netif_is_bridge_master(upper_dev))
+			return 0;
+		if (!mlxsw_sp_lower_get(upper_dev))
+			return 0;
+		return mlxsw_sp_bridge_vxlan_join(mlxsw_sp, upper_dev, dev,
+						  extack);
+	case NETDEV_DOWN:
+		upper_dev = netdev_master_upper_dev_get(dev);
+		if (!upper_dev)
+			return 0;
+		if (!netif_is_bridge_master(upper_dev))
+			return 0;
+		if (!mlxsw_sp_lower_get(upper_dev))
+			return 0;
+		mlxsw_sp_bridge_vxlan_leave(mlxsw_sp, upper_dev, dev);
+		break;
+	}
+
+	return 0;
+}
+
 static int mlxsw_sp_netdevice_event(struct notifier_block *nb,
 				    unsigned long event, void *ptr)
 {
@@ -4935,6 +5037,8 @@ static int mlxsw_sp_netdevice_event(struct notifier_block *nb,
 	}
 	mlxsw_sp_span_respin(mlxsw_sp);
 
+	if (netif_is_vxlan(dev))
+		err = mlxsw_sp_netdevice_vxlan_event(mlxsw_sp, dev, event, ptr);
 	if (mlxsw_sp_netdev_is_ipip_ol(mlxsw_sp, dev))
 		err = mlxsw_sp_netdevice_ipip_ol_event(mlxsw_sp, dev,
 						       event, ptr);