net: mscc: ocelot: enforce FDB isolation when VLAN-unaware

Currently ocelot uses a pvid of 0 for standalone ports and ports under a
VLAN-unaware bridge, and the pvid of the bridge for ports under a
VLAN-aware bridge. Standalone ports do not perform learning, but packets
received on them are still subject to FDB lookups. So if the MAC DA that
a standalone port receives has been also learned on a VLAN-unaware
bridge port, ocelot will attempt to forward to that port, even though it
can't, so it will drop packets.

So there is a desire to avoid that, and isolate the FDBs of different
bridges from one another, and from standalone ports.

The ocelot switch library has two distinct entry points: the felix DSA
driver and the ocelot switchdev driver.

We need to code up a minimal bridge_num allocation in the ocelot
switchdev driver too, this is copied from DSA with the exception that
ocelot does not care about DSA trees, cross-chip bridging etc. So it
only looks at its own ports that are already in the same bridge.

The ocelot switchdev driver uses the bridge_num it has allocated itself,
while the felix driver uses the bridge_num allocated by DSA. They are
both stored inside ocelot_port->bridge_num by the common function
ocelot_port_bridge_join() which receives the bridge_num passed by value.

Once we have a bridge_num, we can only use it to enforce isolation
between VLAN-unaware bridges. As far as I can see, ocelot does not have
anything like a FID that further makes VLAN 100 from a port be different
to VLAN 100 from another port with regard to FDB lookup. So we simply
deny multiple VLAN-aware bridges.

For VLAN-unaware bridges, we crop the 4000-4095 VLAN region and we
allocate a VLAN for each bridge_num. This will be used as the pvid of
each port that is under that VLAN-unaware bridge, for as long as that
bridge is VLAN-unaware.

VID 0 remains only for standalone ports. It is okay if all standalone
ports use the same VID 0, since they perform no address learning, the
FDB will contain no entry in VLAN 0, so the packets will always be
flooded to the only possible destination, the CPU port.

The CPU port module doesn't need to be member of the VLANs to receive
packets, but if we use the DSA tag_8021q protocol, those packets are
part of the data plane as far as ocelot is concerned, so there it needs
to. Just ensure that the DSA tag_8021q CPU port is a member of all
reserved VLANs when it is created, and is removed when it is deleted.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 183 insertions, 17 deletions

diff --git a/drivers/net/ethernet/mscc/ocelot.c b/drivers/net/ethernet/mscc/ocelot.c
index 0e8fa0a4fc69..0af321f6fb54 100644
--- a/drivers/net/ethernet/mscc/ocelot.c
+++ b/drivers/net/ethernet/mscc/ocelot.c
@@ -13,6 +13,7 @@
 
 #define TABLE_UPDATE_SLEEP_US 10
 #define TABLE_UPDATE_TIMEOUT_US 100000
+#define OCELOT_RSV_VLAN_RANGE_START 4000
 
 struct ocelot_mact_entry {
 	u8 mac[ETH_ALEN];
@@ -221,6 +222,35 @@ static void ocelot_vcap_enable(struct ocelot *ocelot, int port)
 		       REW_PORT_CFG, port);
 }
 
+static int ocelot_single_vlan_aware_bridge(struct ocelot *ocelot,
+					   struct netlink_ext_ack *extack)
+{
+	struct net_device *bridge = NULL;
+	int port;
+
+	for (port = 0; port < ocelot->num_phys_ports; port++) {
+		struct ocelot_port *ocelot_port = ocelot->ports[port];
+
+		if (!ocelot_port || !ocelot_port->bridge ||
+		    !br_vlan_enabled(ocelot_port->bridge))
+			continue;
+
+		if (!bridge) {
+			bridge = ocelot_port->bridge;
+			continue;
+		}
+
+		if (bridge == ocelot_port->bridge)
+			continue;
+
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Only one VLAN-aware bridge is supported");
+		return -EBUSY;
+	}
+
+	return 0;
+}
+
 static inline u32 ocelot_vlant_read_vlanaccess(struct ocelot *ocelot)
 {
 	return ocelot_read(ocelot, ANA_TABLES_VLANACCESS);
@@ -347,12 +377,45 @@ static void ocelot_port_manage_port_tag(struct ocelot *ocelot, int port)
 	}
 }
 
+int ocelot_bridge_num_find(struct ocelot *ocelot,
+			   const struct net_device *bridge)
+{
+	int port;
+
+	for (port = 0; port < ocelot->num_phys_ports; port++) {
+		struct ocelot_port *ocelot_port = ocelot->ports[port];
+
+		if (ocelot_port && ocelot_port->bridge == bridge)
+			return ocelot_port->bridge_num;
+	}
+
+	return -1;
+}
+EXPORT_SYMBOL_GPL(ocelot_bridge_num_find);
+
+static u16 ocelot_vlan_unaware_pvid(struct ocelot *ocelot,
+				    const struct net_device *bridge)
+{
+	int bridge_num;
+
+	/* Standalone ports use VID 0 */
+	if (!bridge)
+		return 0;
+
+	bridge_num = ocelot_bridge_num_find(ocelot, bridge);
+	if (WARN_ON(bridge_num < 0))
+		return 0;
+
+	/* VLAN-unaware bridges use a reserved VID going from 4095 downwards */
+	return VLAN_N_VID - bridge_num - 1;
+}
+
 /* Default vlan to clasify for untagged frames (may be zero) */
 static void ocelot_port_set_pvid(struct ocelot *ocelot, int port,
 				 const struct ocelot_bridge_vlan *pvid_vlan)
 {
 	struct ocelot_port *ocelot_port = ocelot->ports[port];
-	u16 pvid = OCELOT_VLAN_UNAWARE_PVID;
+	u16 pvid = ocelot_vlan_unaware_pvid(ocelot, ocelot_port->bridge);
 	u32 val = 0;
 
 	ocelot_port->pvid_vlan = pvid_vlan;
@@ -466,12 +529,29 @@ static int ocelot_vlan_member_del(struct ocelot *ocelot, int port, u16 vid)
 	return 0;
 }
 
+static int ocelot_add_vlan_unaware_pvid(struct ocelot *ocelot, int port,
+					const struct net_device *bridge)
+{
+	u16 vid = ocelot_vlan_unaware_pvid(ocelot, bridge);
+
+	return ocelot_vlan_member_add(ocelot, port, vid, true);
+}
+
+static int ocelot_del_vlan_unaware_pvid(struct ocelot *ocelot, int port,
+					const struct net_device *bridge)
+{
+	u16 vid = ocelot_vlan_unaware_pvid(ocelot, bridge);
+
+	return ocelot_vlan_member_del(ocelot, port, vid);
+}
+
 int ocelot_port_vlan_filtering(struct ocelot *ocelot, int port,
 			       bool vlan_aware, struct netlink_ext_ack *extack)
 {
 	struct ocelot_vcap_block *block = &ocelot->block[VCAP_IS1];
 	struct ocelot_port *ocelot_port = ocelot->ports[port];
 	struct ocelot_vcap_filter *filter;
+	int err;
 	u32 val;
 
 	list_for_each_entry(filter, &block->rules, list) {
@@ -483,6 +563,19 @@ int ocelot_port_vlan_filtering(struct ocelot *ocelot, int port,
 		}
 	}
 
+	err = ocelot_single_vlan_aware_bridge(ocelot, extack);
+	if (err)
+		return err;
+
+	if (vlan_aware)
+		err = ocelot_del_vlan_unaware_pvid(ocelot, port,
+						   ocelot_port->bridge);
+	else
+		err = ocelot_add_vlan_unaware_pvid(ocelot, port,
+						   ocelot_port->bridge);
+	if (err)
+		return err;
+
 	ocelot_port->vlan_aware = vlan_aware;
 
 	if (vlan_aware)
@@ -521,6 +614,12 @@ int ocelot_vlan_prepare(struct ocelot *ocelot, int port, u16 vid, bool pvid,
 		}
 	}
 
+	if (vid > OCELOT_RSV_VLAN_RANGE_START) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "VLAN range 4000-4095 reserved for VLAN-unaware bridging");
+		return -EBUSY;
+	}
+
 	return 0;
 }
 EXPORT_SYMBOL(ocelot_vlan_prepare);
@@ -584,11 +683,11 @@ static void ocelot_vlan_init(struct ocelot *ocelot)
 	for (vid = 1; vid < VLAN_N_VID; vid++)
 		ocelot_vlant_set_mask(ocelot, vid, 0);
 
-	/* Because VLAN filtering is enabled, we need VID 0 to get untagged
-	 * traffic.  It is added automatically if 8021q module is loaded, but
-	 * we can't rely on it since module may be not loaded.
+	/* We need VID 0 to get traffic on standalone ports.
+	 * It is added automatically if the 8021q module is loaded, but we
+	 * can't rely on that since it might not be.
 	 */
-	ocelot_vlant_set_mask(ocelot, OCELOT_VLAN_UNAWARE_PVID, all_ports);
+	ocelot_vlant_set_mask(ocelot, OCELOT_STANDALONE_PVID, all_ports);
 
 	/* Set vlan ingress filter mask to all ports but the CPU port by
 	 * default.
@@ -1237,21 +1336,27 @@ void ocelot_drain_cpu_queue(struct ocelot *ocelot, int grp)
 }
 EXPORT_SYMBOL(ocelot_drain_cpu_queue);
 
-int ocelot_fdb_add(struct ocelot *ocelot, int port,
-		   const unsigned char *addr, u16 vid)
+int ocelot_fdb_add(struct ocelot *ocelot, int port, const unsigned char *addr,
+		   u16 vid, const struct net_device *bridge)
 {
 	int pgid = port;
 
 	if (port == ocelot->npi)
 		pgid = PGID_CPU;
 
+	if (!vid)
+		vid = ocelot_vlan_unaware_pvid(ocelot, bridge);
+
 	return ocelot_mact_learn(ocelot, pgid, addr, vid, ENTRYTYPE_LOCKED);
 }
 EXPORT_SYMBOL(ocelot_fdb_add);
 
-int ocelot_fdb_del(struct ocelot *ocelot, int port,
-		   const unsigned char *addr, u16 vid)
+int ocelot_fdb_del(struct ocelot *ocelot, int port, const unsigned char *addr,
+		   u16 vid, const struct net_device *bridge)
 {
+	if (!vid)
+		vid = ocelot_vlan_unaware_pvid(ocelot, bridge);
+
 	return ocelot_mact_forget(ocelot, addr, vid);
 }
 EXPORT_SYMBOL(ocelot_fdb_del);
@@ -1413,6 +1518,12 @@ int ocelot_fdb_dump(struct ocelot *ocelot, int port,
 
 			is_static = (entry.type == ENTRYTYPE_LOCKED);
 
+			/* Hide the reserved VLANs used for
+			 * VLAN-unaware bridging.
+			 */
+			if (entry.vid > OCELOT_RSV_VLAN_RANGE_START)
+				entry.vid = 0;
+
 			err = cb(entry.mac, entry.vid, is_static, data);
 			if (err)
 				break;
@@ -2054,6 +2165,28 @@ void ocelot_apply_bridge_fwd_mask(struct ocelot *ocelot, bool joining)
 }
 EXPORT_SYMBOL(ocelot_apply_bridge_fwd_mask);
 
+void ocelot_port_set_dsa_8021q_cpu(struct ocelot *ocelot, int port)
+{
+	u16 vid;
+
+	ocelot->ports[port]->is_dsa_8021q_cpu = true;
+
+	for (vid = OCELOT_RSV_VLAN_RANGE_START; vid < VLAN_N_VID; vid++)
+		ocelot_vlan_member_add(ocelot, port, vid, true);
+}
+EXPORT_SYMBOL_GPL(ocelot_port_set_dsa_8021q_cpu);
+
+void ocelot_port_unset_dsa_8021q_cpu(struct ocelot *ocelot, int port)
+{
+	u16 vid;
+
+	ocelot->ports[port]->is_dsa_8021q_cpu = false;
+
+	for (vid = OCELOT_RSV_VLAN_RANGE_START; vid < VLAN_N_VID; vid++)
+		ocelot_vlan_member_del(ocelot, port, vid);
+}
+EXPORT_SYMBOL_GPL(ocelot_port_unset_dsa_8021q_cpu);
+
 void ocelot_bridge_stp_state_set(struct ocelot *ocelot, int port, u8 state)
 {
 	struct ocelot_port *ocelot_port = ocelot->ports[port];
@@ -2198,7 +2331,8 @@ static void ocelot_encode_ports_to_mdb(unsigned char *addr,
 }
 
 int ocelot_port_mdb_add(struct ocelot *ocelot, int port,
-			const struct switchdev_obj_port_mdb *mdb)
+			const struct switchdev_obj_port_mdb *mdb,
+			const struct net_device *bridge)
 {
 	unsigned char addr[ETH_ALEN];
 	struct ocelot_multicast *mc;
@@ -2208,6 +2342,9 @@ int ocelot_port_mdb_add(struct ocelot *ocelot, int port,
 	if (port == ocelot->npi)
 		port = ocelot->num_phys_ports;
 
+	if (!vid)
+		vid = ocelot_vlan_unaware_pvid(ocelot, bridge);
+
 	mc = ocelot_multicast_get(ocelot, mdb->addr, vid);
 	if (!mc) {
 		/* New entry */
@@ -2254,7 +2391,8 @@ int ocelot_port_mdb_add(struct ocelot *ocelot, int port,
 EXPORT_SYMBOL(ocelot_port_mdb_add);
 
 int ocelot_port_mdb_del(struct ocelot *ocelot, int port,
-			const struct switchdev_obj_port_mdb *mdb)
+			const struct switchdev_obj_port_mdb *mdb,
+			const struct net_device *bridge)
 {
 	unsigned char addr[ETH_ALEN];
 	struct ocelot_multicast *mc;
@@ -2264,6 +2402,9 @@ int ocelot_port_mdb_del(struct ocelot *ocelot, int port,
 	if (port == ocelot->npi)
 		port = ocelot->num_phys_ports;
 
+	if (!vid)
+		vid = ocelot_vlan_unaware_pvid(ocelot, bridge);
+
 	mc = ocelot_multicast_get(ocelot, mdb->addr, vid);
 	if (!mc)
 		return -ENOENT;
@@ -2297,18 +2438,30 @@ int ocelot_port_mdb_del(struct ocelot *ocelot, int port,
 }
 EXPORT_SYMBOL(ocelot_port_mdb_del);
 
-void ocelot_port_bridge_join(struct ocelot *ocelot, int port,
-			     struct net_device *bridge)
+int ocelot_port_bridge_join(struct ocelot *ocelot, int port,
+			    struct net_device *bridge, int bridge_num,
+			    struct netlink_ext_ack *extack)
 {
 	struct ocelot_port *ocelot_port = ocelot->ports[port];
+	int err;
+
+	err = ocelot_single_vlan_aware_bridge(ocelot, extack);
+	if (err)
+		return err;
 
 	mutex_lock(&ocelot->fwd_domain_lock);
 
 	ocelot_port->bridge = bridge;
+	ocelot_port->bridge_num = bridge_num;
 
 	ocelot_apply_bridge_fwd_mask(ocelot, true);
 
 	mutex_unlock(&ocelot->fwd_domain_lock);
+
+	if (br_vlan_enabled(bridge))
+		return 0;
+
+	return ocelot_add_vlan_unaware_pvid(ocelot, port, bridge);
 }
 EXPORT_SYMBOL(ocelot_port_bridge_join);
 
@@ -2319,7 +2472,11 @@ void ocelot_port_bridge_leave(struct ocelot *ocelot, int port,
 
 	mutex_lock(&ocelot->fwd_domain_lock);
 
+	if (!br_vlan_enabled(bridge))
+		ocelot_del_vlan_unaware_pvid(ocelot, port, bridge);
+
 	ocelot_port->bridge = NULL;
+	ocelot_port->bridge_num = -1;
 
 	ocelot_port_set_pvid(ocelot, port, NULL);
 	ocelot_port_manage_port_tag(ocelot, port);
@@ -2544,7 +2701,8 @@ void ocelot_port_lag_change(struct ocelot *ocelot, int port, bool lag_tx_active)
 EXPORT_SYMBOL(ocelot_port_lag_change);
 
 int ocelot_lag_fdb_add(struct ocelot *ocelot, struct net_device *bond,
-		       const unsigned char *addr, u16 vid)
+		       const unsigned char *addr, u16 vid,
+		       const struct net_device *bridge)
 {
 	struct ocelot_lag_fdb *fdb;
 	int lag, err;
@@ -2553,11 +2711,15 @@ int ocelot_lag_fdb_add(struct ocelot *ocelot, struct net_device *bond,
 	if (!fdb)
 		return -ENOMEM;
 
+	mutex_lock(&ocelot->fwd_domain_lock);
+
+	if (!vid)
+		vid = ocelot_vlan_unaware_pvid(ocelot, bridge);
+
 	ether_addr_copy(fdb->addr, addr);
 	fdb->vid = vid;
 	fdb->bond = bond;
 
-	mutex_lock(&ocelot->fwd_domain_lock);
 	lag = ocelot_bond_get_id(ocelot, bond);
 
 	err = ocelot_mact_learn(ocelot, lag, addr, vid, ENTRYTYPE_LOCKED);
@@ -2575,12 +2737,16 @@ int ocelot_lag_fdb_add(struct ocelot *ocelot, struct net_device *bond,
 EXPORT_SYMBOL_GPL(ocelot_lag_fdb_add);
 
 int ocelot_lag_fdb_del(struct ocelot *ocelot, struct net_device *bond,
-		       const unsigned char *addr, u16 vid)
+		       const unsigned char *addr, u16 vid,
+		       const struct net_device *bridge)
 {
 	struct ocelot_lag_fdb *fdb, *tmp;
 
 	mutex_lock(&ocelot->fwd_domain_lock);
 
+	if (!vid)
+		vid = ocelot_vlan_unaware_pvid(ocelot, bridge);
+
 	list_for_each_entry_safe(fdb, tmp, &ocelot->lag_fdbs, list) {
 		if (!ether_addr_equal(fdb->addr, addr) || fdb->vid != vid ||
 		    fdb->bond != bond)
@@ -2832,7 +2998,7 @@ static void ocelot_cpu_port_init(struct ocelot *ocelot)
 
 	/* Configure the CPU port to be VLAN aware */
 	ocelot_write_gix(ocelot,
-			 ANA_PORT_VLAN_CFG_VLAN_VID(OCELOT_VLAN_UNAWARE_PVID) |
+			 ANA_PORT_VLAN_CFG_VLAN_VID(OCELOT_STANDALONE_PVID) |
 			 ANA_PORT_VLAN_CFG_VLAN_AWARE_ENA |
 			 ANA_PORT_VLAN_CFG_VLAN_POP_CNT(1),
 			 ANA_PORT_VLAN_CFG, cpu);