Merge branch 'fdb-fanout'

Vladimir Oltean says:

====================
Fan out FDB entries pointing towards the bridge to all switchdev member ports

The "DSA RX filtering" series has added some important support for
interpreting addresses towards the bridge device as host addresses and
installing them as FDB entries towards the CPU port, but it does not
cover all circumstances and needs further work.

To be precise, the mechanism introduced in that series only works as
long as the ports are fairly static and no port joins or leaves the
bridge once the configuration is done. If any port leaves, host FDB
entries that were installed during runtime (for example the user changes
the MAC address of the bridge device) will be prematurely deleted,
resulting in a broken setup.

I see this work as targeted for "net-next" because technically it was
not supposed to work. Also, there are still corner cases and holes to be
plugged. For example, today, FDB entries on foreign interfaces are not
covered by br_fdb_replay(), which means that there are cases where some
host addresses are either lost, or never deleted by DSA. That will be
resolved once more work gets accepted, in particular the "Allow
forwarding for the software bridge data path to be offloaded to capable
devices" series, which moves the br_fdb_replay() call to the bridge core
and therefore would be required to solve the problem in a generic way
for every switchdev driver and not just for DSA.

These patches also pave the way for a cleaner implementation for FDB
entries pointing towards a LAG upper interface in DSA (that code needs
only to be added, nothing changed), however this is not done here.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 190 insertions, 0 deletions

diff --git a/net/switchdev/switchdev.c b/net/switchdev/switchdev.c
index 070698dd19bc..82dd4e4e86f5 100644
--- a/net/switchdev/switchdev.c
+++ b/net/switchdev/switchdev.c
@@ -378,6 +378,196 @@ int call_switchdev_blocking_notifiers(unsigned long val, struct net_device *dev,
 }
 EXPORT_SYMBOL_GPL(call_switchdev_blocking_notifiers);
 
+static int __switchdev_handle_fdb_add_to_device(struct net_device *dev,
+		const struct net_device *orig_dev,
+		const struct switchdev_notifier_fdb_info *fdb_info,
+		bool (*check_cb)(const struct net_device *dev),
+		bool (*foreign_dev_check_cb)(const struct net_device *dev,
+					     const struct net_device *foreign_dev),
+		int (*add_cb)(struct net_device *dev,
+			      const struct net_device *orig_dev, const void *ctx,
+			      const struct switchdev_notifier_fdb_info *fdb_info),
+		int (*lag_add_cb)(struct net_device *dev,
+				  const struct net_device *orig_dev, const void *ctx,
+				  const struct switchdev_notifier_fdb_info *fdb_info))
+{
+	const struct switchdev_notifier_info *info = &fdb_info->info;
+	struct net_device *lower_dev;
+	struct list_head *iter;
+	int err = -EOPNOTSUPP;
+
+	if (check_cb(dev)) {
+		/* Handle FDB entries on foreign interfaces as FDB entries
+		 * towards the software bridge.
+		 */
+		if (foreign_dev_check_cb && foreign_dev_check_cb(dev, orig_dev)) {
+			struct net_device *br = netdev_master_upper_dev_get_rcu(dev);
+
+			if (!br || !netif_is_bridge_master(br))
+				return 0;
+
+			/* No point in handling FDB entries on a foreign bridge */
+			if (foreign_dev_check_cb(dev, br))
+				return 0;
+
+			return __switchdev_handle_fdb_add_to_device(br, orig_dev,
+								    fdb_info, check_cb,
+								    foreign_dev_check_cb,
+								    add_cb, lag_add_cb);
+		}
+
+		return add_cb(dev, orig_dev, info->ctx, fdb_info);
+	}
+
+	/* If we passed over the foreign check, it means that the LAG interface
+	 * is offloaded.
+	 */
+	if (netif_is_lag_master(dev)) {
+		if (!lag_add_cb)
+			return -EOPNOTSUPP;
+
+		return lag_add_cb(dev, orig_dev, info->ctx, fdb_info);
+	}
+
+	/* Recurse through lower interfaces in case the FDB entry is pointing
+	 * towards a bridge device.
+	 */
+	netdev_for_each_lower_dev(dev, lower_dev, iter) {
+		/* Do not propagate FDB entries across bridges */
+		if (netif_is_bridge_master(lower_dev))
+			continue;
+
+		err = __switchdev_handle_fdb_add_to_device(lower_dev, orig_dev,
+							   fdb_info, check_cb,
+							   foreign_dev_check_cb,
+							   add_cb, lag_add_cb);
+		if (err && err != -EOPNOTSUPP)
+			return err;
+	}
+
+	return err;
+}
+
+int switchdev_handle_fdb_add_to_device(struct net_device *dev,
+		const struct switchdev_notifier_fdb_info *fdb_info,
+		bool (*check_cb)(const struct net_device *dev),
+		bool (*foreign_dev_check_cb)(const struct net_device *dev,
+					     const struct net_device *foreign_dev),
+		int (*add_cb)(struct net_device *dev,
+			      const struct net_device *orig_dev, const void *ctx,
+			      const struct switchdev_notifier_fdb_info *fdb_info),
+		int (*lag_add_cb)(struct net_device *dev,
+				  const struct net_device *orig_dev, const void *ctx,
+				  const struct switchdev_notifier_fdb_info *fdb_info))
+{
+	int err;
+
+	err = __switchdev_handle_fdb_add_to_device(dev, dev, fdb_info,
+						   check_cb,
+						   foreign_dev_check_cb,
+						   add_cb, lag_add_cb);
+	if (err == -EOPNOTSUPP)
+		err = 0;
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(switchdev_handle_fdb_add_to_device);
+
+static int __switchdev_handle_fdb_del_to_device(struct net_device *dev,
+		const struct net_device *orig_dev,
+		const struct switchdev_notifier_fdb_info *fdb_info,
+		bool (*check_cb)(const struct net_device *dev),
+		bool (*foreign_dev_check_cb)(const struct net_device *dev,
+					     const struct net_device *foreign_dev),
+		int (*del_cb)(struct net_device *dev,
+			      const struct net_device *orig_dev, const void *ctx,
+			      const struct switchdev_notifier_fdb_info *fdb_info),
+		int (*lag_del_cb)(struct net_device *dev,
+				  const struct net_device *orig_dev, const void *ctx,
+				  const struct switchdev_notifier_fdb_info *fdb_info))
+{
+	const struct switchdev_notifier_info *info = &fdb_info->info;
+	struct net_device *lower_dev;
+	struct list_head *iter;
+	int err = -EOPNOTSUPP;
+
+	if (check_cb(dev)) {
+		/* Handle FDB entries on foreign interfaces as FDB entries
+		 * towards the software bridge.
+		 */
+		if (foreign_dev_check_cb && foreign_dev_check_cb(dev, orig_dev)) {
+			struct net_device *br = netdev_master_upper_dev_get_rcu(dev);
+
+			if (!br || !netif_is_bridge_master(br))
+				return 0;
+
+			/* No point in handling FDB entries on a foreign bridge */
+			if (foreign_dev_check_cb(dev, br))
+				return 0;
+
+			return __switchdev_handle_fdb_del_to_device(br, orig_dev,
+								    fdb_info, check_cb,
+								    foreign_dev_check_cb,
+								    del_cb, lag_del_cb);
+		}
+
+		return del_cb(dev, orig_dev, info->ctx, fdb_info);
+	}
+
+	/* If we passed over the foreign check, it means that the LAG interface
+	 * is offloaded.
+	 */
+	if (netif_is_lag_master(dev)) {
+		if (!lag_del_cb)
+			return -EOPNOTSUPP;
+
+		return lag_del_cb(dev, orig_dev, info->ctx, fdb_info);
+	}
+
+	/* Recurse through lower interfaces in case the FDB entry is pointing
+	 * towards a bridge device.
+	 */
+	netdev_for_each_lower_dev(dev, lower_dev, iter) {
+		/* Do not propagate FDB entries across bridges */
+		if (netif_is_bridge_master(lower_dev))
+			continue;
+
+		err = switchdev_handle_fdb_del_to_device(lower_dev, fdb_info,
+							 check_cb,
+							 foreign_dev_check_cb,
+							 del_cb, lag_del_cb);
+		if (err && err != -EOPNOTSUPP)
+			return err;
+	}
+
+	return err;
+}
+
+int switchdev_handle_fdb_del_to_device(struct net_device *dev,
+		const struct switchdev_notifier_fdb_info *fdb_info,
+		bool (*check_cb)(const struct net_device *dev),
+		bool (*foreign_dev_check_cb)(const struct net_device *dev,
+					     const struct net_device *foreign_dev),
+		int (*del_cb)(struct net_device *dev,
+			      const struct net_device *orig_dev, const void *ctx,
+			      const struct switchdev_notifier_fdb_info *fdb_info),
+		int (*lag_del_cb)(struct net_device *dev,
+				  const struct net_device *orig_dev, const void *ctx,
+				  const struct switchdev_notifier_fdb_info *fdb_info))
+{
+	int err;
+
+	err = __switchdev_handle_fdb_del_to_device(dev, dev, fdb_info,
+						   check_cb,
+						   foreign_dev_check_cb,
+						   del_cb, lag_del_cb);
+	if (err == -EOPNOTSUPP)
+		err = 0;
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(switchdev_handle_fdb_del_to_device);
+
 static int __switchdev_handle_port_obj_add(struct net_device *dev,
 			struct switchdev_notifier_port_obj_info *port_obj_info,
 			bool (*check_cb)(const struct net_device *dev),