Merge branch 'dsa-fdb-isolation'

Vladimir Oltean says:

====================
DSA FDB isolation

There are use cases which need FDB isolation between standalone ports
and bridged ports, as well as isolation between ports of different
bridges. Most of these use cases are a result of the fact that packets
can now be partially forwarded by the software bridge, so one port might
need to send a packet to the CPU but its FDB lookup will see that it can
forward it directly to a bridge port where that packet was autonomously
learned. So the source port will attempt to shortcircuit the CPU and
forward autonomously, which it can't due to the forwarding isolation we
have in place. So we will have packet drops instead of proper operation.

Additionally, before DSA can implement IFF_UNICAST_FLT for standalone
ports, we must have control over which database we install FDB entries
corresponding to port MAC addresses in. We don't want to hinder the
operation of the bridging layer.

DSA does not have a driver API that encourages FDB isolation, so this
needs to be created. The basis for this is a new struct dsa_db which
annotates each FDB and MDB entry with the database it belongs to.

The sja1105 and felix drivers are modified to observe the dsa_db
argument, and therefore, enforce the FDB isolation.

Compared to the previous RFC patch series from August:
https://patchwork.kernel.org/project/netdevbpf/cover/20210818120150.892647-1-vladimir.oltean@nxp.com/

what is different is that I stopped trying to make SWITCHDEV_FDB_{ADD,DEL}_TO_DEVICE
blocking, instead I'm making use of the fact that DSA waits for switchdev FDB work
items to finish before a port leaves the bridge. This is possible since:
https://patchwork.kernel.org/project/netdevbpf/patch/20211024171757.3753288-7-vladimir.oltean@nxp.com/

Additionally, v2 is also rebased over the DSA LAG FDB work.
====================

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

1 files changed, 40 insertions, 8 deletions

diff --git a/include/net/dsa.h b/include/net/dsa.h
index 01faba89c987..cfedcfb86350 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -341,11 +341,28 @@ struct dsa_link {
 	struct list_head list;
 };
 
+enum dsa_db_type {
+	DSA_DB_PORT,
+	DSA_DB_LAG,
+	DSA_DB_BRIDGE,
+};
+
+struct dsa_db {
+	enum dsa_db_type type;
+
+	union {
+		const struct dsa_port *dp;
+		struct dsa_lag lag;
+		struct dsa_bridge bridge;
+	};
+};
+
 struct dsa_mac_addr {
 	unsigned char addr[ETH_ALEN];
 	u16 vid;
 	refcount_t refcount;
 	struct list_head list;
+	struct dsa_db db;
 };
 
 struct dsa_vlan {
@@ -409,6 +426,13 @@ struct dsa_switch {
 	 */
 	u32			mtu_enforcement_ingress:1;
 
+	/* Drivers that isolate the FDBs of multiple bridges must set this
+	 * to true to receive the bridge as an argument in .port_fdb_{add,del}
+	 * and .port_mdb_{add,del}. Otherwise, the bridge.num will always be
+	 * passed as zero.
+	 */
+	u32			fdb_isolation:1;
+
 	/* Listener for switch fabric events */
 	struct notifier_block	nb;
 
@@ -913,7 +937,8 @@ struct dsa_switch_ops {
 	int	(*set_ageing_time)(struct dsa_switch *ds, unsigned int msecs);
 	int	(*port_bridge_join)(struct dsa_switch *ds, int port,
 				    struct dsa_bridge bridge,
-				    bool *tx_fwd_offload);
+				    bool *tx_fwd_offload,
+				    struct netlink_ext_ack *extack);
 	void	(*port_bridge_leave)(struct dsa_switch *ds, int port,
 				     struct dsa_bridge bridge);
 	void	(*port_stp_state_set)(struct dsa_switch *ds, int port,
@@ -941,23 +966,29 @@ struct dsa_switch_ops {
 	 * Forwarding database
 	 */
 	int	(*port_fdb_add)(struct dsa_switch *ds, int port,
-				const unsigned char *addr, u16 vid);
+				const unsigned char *addr, u16 vid,
+				struct dsa_db db);
 	int	(*port_fdb_del)(struct dsa_switch *ds, int port,
-				const unsigned char *addr, u16 vid);
+				const unsigned char *addr, u16 vid,
+				struct dsa_db db);
 	int	(*port_fdb_dump)(struct dsa_switch *ds, int port,
 				 dsa_fdb_dump_cb_t *cb, void *data);
 	int	(*lag_fdb_add)(struct dsa_switch *ds, struct dsa_lag lag,
-			       const unsigned char *addr, u16 vid);
+			       const unsigned char *addr, u16 vid,
+			       struct dsa_db db);
 	int	(*lag_fdb_del)(struct dsa_switch *ds, struct dsa_lag lag,
-			       const unsigned char *addr, u16 vid);
+			       const unsigned char *addr, u16 vid,
+			       struct dsa_db db);
 
 	/*
 	 * Multicast database
 	 */
 	int	(*port_mdb_add)(struct dsa_switch *ds, int port,
-				const struct switchdev_obj_port_mdb *mdb);
+				const struct switchdev_obj_port_mdb *mdb,
+				struct dsa_db db);
 	int	(*port_mdb_del)(struct dsa_switch *ds, int port,
-				const struct switchdev_obj_port_mdb *mdb);
+				const struct switchdev_obj_port_mdb *mdb,
+				struct dsa_db db);
 	/*
 	 * RXNFC
 	 */
@@ -991,7 +1022,8 @@ struct dsa_switch_ops {
 	 */
 	int	(*crosschip_bridge_join)(struct dsa_switch *ds, int tree_index,
 					 int sw_index, int port,
-					 struct dsa_bridge bridge);
+					 struct dsa_bridge bridge,
+					 struct netlink_ext_ack *extack);
 	void	(*crosschip_bridge_leave)(struct dsa_switch *ds, int tree_index,
 					  int sw_index, int port,
 					  struct dsa_bridge bridge);