Merge branch 'dsa-rx-filtering'

Vladimir Oltean says:

====================
RX filtering in DSA

This is my fourth stab (identical to the third one except sent as
non-RFC) at creating a list of unicast and multicast addresses that the
DSA CPU ports must trap. I am reusing a lot of Tobias's work which he
submitted here:
https://patchwork.kernel.org/project/netdevbpf/cover/20210116012515.3152-1-tobias@waldekranz.com/

My additions to Tobias' work come in the form of taking some care that
additions and removals of host addresses are properly balanced, so that
we can do reference counting on them for cross-chip setups and multiple
bridges spanning the same switch (I am working on an NXP board where
both are real requirements).

During the last attempted submission of multiple CPU ports for DSA:
https://patchwork.kernel.org/project/netdevbpf/cover/20210410133454.4768-1-ansuelsmth@gmail.com/

it became clear that the concept of multiple CPU ports would not be
compatible with the idea of address learning on those CPU ports (when
those CPU ports are statically assigned to user ports, not in a LAG)
unless the switch supports complete FDB isolation, which most switches
do not. So DSA needs to manage in software all addresses that are
installed on the CPU port(s), which is what this patch set does.

Compared to all earlier attempts, this series does not fiddle with how
DSA operates the ports in standalone mode at all, just when bridged.
We need to sort that out properly, then any optimization that comes in
standalone mode (i.e. IFF_UNICAST_FLT) can come later.
====================

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

1 files changed, 39 insertions, 0 deletions

diff --git a/include/net/dsa.h b/include/net/dsa.h
index ea47783d5695..33f40c1ec379 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -285,6 +285,12 @@ struct dsa_port {
 	 */
 	const struct dsa_netdevice_ops *netdev_ops;
 
+	/* List of MAC addresses that must be forwarded on this port.
+	 * These are only valid on CPU ports and DSA links.
+	 */
+	struct list_head	fdbs;
+	struct list_head	mdbs;
+
 	bool setup;
 };
 
@@ -299,6 +305,13 @@ struct dsa_link {
 	struct list_head list;
 };
 
+struct dsa_mac_addr {
+	unsigned char addr[ETH_ALEN];
+	u16 vid;
+	refcount_t refcount;
+	struct list_head list;
+};
+
 struct dsa_switch {
 	bool setup;
 
@@ -491,6 +504,32 @@ static inline unsigned int dsa_upstream_port(struct dsa_switch *ds, int port)
 	return dsa_towards_port(ds, cpu_dp->ds->index, cpu_dp->index);
 }
 
+/* Return true if this is the local port used to reach the CPU port */
+static inline bool dsa_is_upstream_port(struct dsa_switch *ds, int port)
+{
+	if (dsa_is_unused_port(ds, port))
+		return false;
+
+	return port == dsa_upstream_port(ds, port);
+}
+
+/* Return true if @upstream_ds is an upstream switch of @downstream_ds, meaning
+ * that the routing port from @downstream_ds to @upstream_ds is also the port
+ * which @downstream_ds uses to reach its dedicated CPU.
+ */
+static inline bool dsa_switch_is_upstream_of(struct dsa_switch *upstream_ds,
+					     struct dsa_switch *downstream_ds)
+{
+	int routing_port;
+
+	if (upstream_ds == downstream_ds)
+		return true;
+
+	routing_port = dsa_routing_port(downstream_ds, upstream_ds->index);
+
+	return dsa_is_upstream_port(downstream_ds, routing_port);
+}
+
 static inline bool dsa_port_is_vlan_filtering(const struct dsa_port *dp)
 {
 	const struct dsa_switch *ds = dp->ds;