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, 267 insertions, 6 deletions

diff --git a/net/dsa/switch.c b/net/dsa/switch.c
index c1e5afafe633..af71b8638098 100644
--- a/net/dsa/switch.c
+++ b/net/dsa/switch.c
@@ -154,6 +154,214 @@ static int dsa_switch_bridge_leave(struct dsa_switch *ds,
 	return 0;
 }
 
+/* Matches for all upstream-facing ports (the CPU port and all upstream-facing
+ * DSA links) that sit between the targeted port on which the notifier was
+ * emitted and its dedicated CPU port.
+ */
+static bool dsa_switch_host_address_match(struct dsa_switch *ds, int port,
+					  int info_sw_index, int info_port)
+{
+	struct dsa_port *targeted_dp, *cpu_dp;
+	struct dsa_switch *targeted_ds;
+
+	targeted_ds = dsa_switch_find(ds->dst->index, info_sw_index);
+	targeted_dp = dsa_to_port(targeted_ds, info_port);
+	cpu_dp = targeted_dp->cpu_dp;
+
+	if (dsa_switch_is_upstream_of(ds, targeted_ds))
+		return port == dsa_towards_port(ds, cpu_dp->ds->index,
+						cpu_dp->index);
+
+	return false;
+}
+
+static struct dsa_mac_addr *dsa_mac_addr_find(struct list_head *addr_list,
+					      const unsigned char *addr,
+					      u16 vid)
+{
+	struct dsa_mac_addr *a;
+
+	list_for_each_entry(a, addr_list, list)
+		if (ether_addr_equal(a->addr, addr) && a->vid == vid)
+			return a;
+
+	return NULL;
+}
+
+static int dsa_switch_do_mdb_add(struct dsa_switch *ds, int port,
+				 const struct switchdev_obj_port_mdb *mdb)
+{
+	struct dsa_port *dp = dsa_to_port(ds, port);
+	struct dsa_mac_addr *a;
+	int err;
+
+	/* No need to bother with refcounting for user ports */
+	if (!(dsa_port_is_cpu(dp) || dsa_port_is_dsa(dp)))
+		return ds->ops->port_mdb_add(ds, port, mdb);
+
+	a = dsa_mac_addr_find(&dp->mdbs, mdb->addr, mdb->vid);
+	if (a) {
+		refcount_inc(&a->refcount);
+		return 0;
+	}
+
+	a = kzalloc(sizeof(*a), GFP_KERNEL);
+	if (!a)
+		return -ENOMEM;
+
+	err = ds->ops->port_mdb_add(ds, port, mdb);
+	if (err) {
+		kfree(a);
+		return err;
+	}
+
+	ether_addr_copy(a->addr, mdb->addr);
+	a->vid = mdb->vid;
+	refcount_set(&a->refcount, 1);
+	list_add_tail(&a->list, &dp->mdbs);
+
+	return 0;
+}
+
+static int dsa_switch_do_mdb_del(struct dsa_switch *ds, int port,
+				 const struct switchdev_obj_port_mdb *mdb)
+{
+	struct dsa_port *dp = dsa_to_port(ds, port);
+	struct dsa_mac_addr *a;
+	int err;
+
+	/* No need to bother with refcounting for user ports */
+	if (!(dsa_port_is_cpu(dp) || dsa_port_is_dsa(dp)))
+		return ds->ops->port_mdb_del(ds, port, mdb);
+
+	a = dsa_mac_addr_find(&dp->mdbs, mdb->addr, mdb->vid);
+	if (!a)
+		return -ENOENT;
+
+	if (!refcount_dec_and_test(&a->refcount))
+		return 0;
+
+	err = ds->ops->port_mdb_del(ds, port, mdb);
+	if (err) {
+		refcount_inc(&a->refcount);
+		return err;
+	}
+
+	list_del(&a->list);
+	kfree(a);
+
+	return 0;
+}
+
+static int dsa_switch_do_fdb_add(struct dsa_switch *ds, int port,
+				 const unsigned char *addr, u16 vid)
+{
+	struct dsa_port *dp = dsa_to_port(ds, port);
+	struct dsa_mac_addr *a;
+	int err;
+
+	/* No need to bother with refcounting for user ports */
+	if (!(dsa_port_is_cpu(dp) || dsa_port_is_dsa(dp)))
+		return ds->ops->port_fdb_add(ds, port, addr, vid);
+
+	a = dsa_mac_addr_find(&dp->fdbs, addr, vid);
+	if (a) {
+		refcount_inc(&a->refcount);
+		return 0;
+	}
+
+	a = kzalloc(sizeof(*a), GFP_KERNEL);
+	if (!a)
+		return -ENOMEM;
+
+	err = ds->ops->port_fdb_add(ds, port, addr, vid);
+	if (err) {
+		kfree(a);
+		return err;
+	}
+
+	ether_addr_copy(a->addr, addr);
+	a->vid = vid;
+	refcount_set(&a->refcount, 1);
+	list_add_tail(&a->list, &dp->fdbs);
+
+	return 0;
+}
+
+static int dsa_switch_do_fdb_del(struct dsa_switch *ds, int port,
+				 const unsigned char *addr, u16 vid)
+{
+	struct dsa_port *dp = dsa_to_port(ds, port);
+	struct dsa_mac_addr *a;
+	int err;
+
+	/* No need to bother with refcounting for user ports */
+	if (!(dsa_port_is_cpu(dp) || dsa_port_is_dsa(dp)))
+		return ds->ops->port_fdb_del(ds, port, addr, vid);
+
+	a = dsa_mac_addr_find(&dp->fdbs, addr, vid);
+	if (!a)
+		return -ENOENT;
+
+	if (!refcount_dec_and_test(&a->refcount))
+		return 0;
+
+	err = ds->ops->port_fdb_del(ds, port, addr, vid);
+	if (err) {
+		refcount_inc(&a->refcount);
+		return err;
+	}
+
+	list_del(&a->list);
+	kfree(a);
+
+	return 0;
+}
+
+static int dsa_switch_host_fdb_add(struct dsa_switch *ds,
+				   struct dsa_notifier_fdb_info *info)
+{
+	int err = 0;
+	int port;
+
+	if (!ds->ops->port_fdb_add)
+		return -EOPNOTSUPP;
+
+	for (port = 0; port < ds->num_ports; port++) {
+		if (dsa_switch_host_address_match(ds, port, info->sw_index,
+						  info->port)) {
+			err = dsa_switch_do_fdb_add(ds, port, info->addr,
+						    info->vid);
+			if (err)
+				break;
+		}
+	}
+
+	return err;
+}
+
+static int dsa_switch_host_fdb_del(struct dsa_switch *ds,
+				   struct dsa_notifier_fdb_info *info)
+{
+	int err = 0;
+	int port;
+
+	if (!ds->ops->port_fdb_del)
+		return -EOPNOTSUPP;
+
+	for (port = 0; port < ds->num_ports; port++) {
+		if (dsa_switch_host_address_match(ds, port, info->sw_index,
+						  info->port)) {
+			err = dsa_switch_do_fdb_del(ds, port, info->addr,
+						    info->vid);
+			if (err)
+				break;
+		}
+	}
+
+	return err;
+}
+
 static int dsa_switch_fdb_add(struct dsa_switch *ds,
 			      struct dsa_notifier_fdb_info *info)
 {
@@ -162,7 +370,7 @@ static int dsa_switch_fdb_add(struct dsa_switch *ds,
 	if (!ds->ops->port_fdb_add)
 		return -EOPNOTSUPP;
 
-	return ds->ops->port_fdb_add(ds, port, info->addr, info->vid);
+	return dsa_switch_do_fdb_add(ds, port, info->addr, info->vid);
 }
 
 static int dsa_switch_fdb_del(struct dsa_switch *ds,
@@ -173,7 +381,7 @@ static int dsa_switch_fdb_del(struct dsa_switch *ds,
 	if (!ds->ops->port_fdb_del)
 		return -EOPNOTSUPP;
 
-	return ds->ops->port_fdb_del(ds, port, info->addr, info->vid);
+	return dsa_switch_do_fdb_del(ds, port, info->addr, info->vid);
 }
 
 static int dsa_switch_hsr_join(struct dsa_switch *ds,
@@ -243,19 +451,60 @@ static int dsa_switch_mdb_add(struct dsa_switch *ds,
 	if (!ds->ops->port_mdb_add)
 		return -EOPNOTSUPP;
 
-	return ds->ops->port_mdb_add(ds, port, info->mdb);
+	return dsa_switch_do_mdb_add(ds, port, info->mdb);
 }
 
 static int dsa_switch_mdb_del(struct dsa_switch *ds,
 			      struct dsa_notifier_mdb_info *info)
 {
+	int port = dsa_towards_port(ds, info->sw_index, info->port);
+
 	if (!ds->ops->port_mdb_del)
 		return -EOPNOTSUPP;
 
-	if (ds->index == info->sw_index)
-		return ds->ops->port_mdb_del(ds, info->port, info->mdb);
+	return dsa_switch_do_mdb_del(ds, port, info->mdb);
+}
 
-	return 0;
+static int dsa_switch_host_mdb_add(struct dsa_switch *ds,
+				   struct dsa_notifier_mdb_info *info)
+{
+	int err = 0;
+	int port;
+
+	if (!ds->ops->port_mdb_add)
+		return -EOPNOTSUPP;
+
+	for (port = 0; port < ds->num_ports; port++) {
+		if (dsa_switch_host_address_match(ds, port, info->sw_index,
+						  info->port)) {
+			err = dsa_switch_do_mdb_add(ds, port, info->mdb);
+			if (err)
+				break;
+		}
+	}
+
+	return err;
+}
+
+static int dsa_switch_host_mdb_del(struct dsa_switch *ds,
+				   struct dsa_notifier_mdb_info *info)
+{
+	int err = 0;
+	int port;
+
+	if (!ds->ops->port_mdb_del)
+		return -EOPNOTSUPP;
+
+	for (port = 0; port < ds->num_ports; port++) {
+		if (dsa_switch_host_address_match(ds, port, info->sw_index,
+						  info->port)) {
+			err = dsa_switch_do_mdb_del(ds, port, info->mdb);
+			if (err)
+				break;
+		}
+	}
+
+	return err;
 }
 
 static bool dsa_switch_vlan_match(struct dsa_switch *ds, int port,
@@ -420,6 +669,12 @@ static int dsa_switch_event(struct notifier_block *nb,
 	case DSA_NOTIFIER_FDB_DEL:
 		err = dsa_switch_fdb_del(ds, info);
 		break;
+	case DSA_NOTIFIER_HOST_FDB_ADD:
+		err = dsa_switch_host_fdb_add(ds, info);
+		break;
+	case DSA_NOTIFIER_HOST_FDB_DEL:
+		err = dsa_switch_host_fdb_del(ds, info);
+		break;
 	case DSA_NOTIFIER_HSR_JOIN:
 		err = dsa_switch_hsr_join(ds, info);
 		break;
@@ -441,6 +696,12 @@ static int dsa_switch_event(struct notifier_block *nb,
 	case DSA_NOTIFIER_MDB_DEL:
 		err = dsa_switch_mdb_del(ds, info);
 		break;
+	case DSA_NOTIFIER_HOST_MDB_ADD:
+		err = dsa_switch_host_mdb_add(ds, info);
+		break;
+	case DSA_NOTIFIER_HOST_MDB_DEL:
+		err = dsa_switch_host_mdb_del(ds, info);
+		break;
 	case DSA_NOTIFIER_VLAN_ADD:
 		err = dsa_switch_vlan_add(ds, info);
 		break;