net: dsa: mv88e6xxx: mac-auth/MAB implementation

This implementation for the Marvell mv88e6xxx chip series,
is based on handling ATU miss violations occurring when packets
ingress on a port that is locked. The mac address triggering
the ATU miss violation will be added to the ATU with a zero-DPV,
and is then communicated through switchdev to the bridge module,
which adds a fdb entry with the fdb locked flag set. The entry
is kept according to the bridges ageing time, thus simulating a
dynamic entry.

As this is essentially a form of CPU based learning, the amount
of locked entries will be limited by a hardcoded value for now,
so as to prevent DOS attacks.

Signed-off-by: Hans Schultz <netdev@kapio-technology.com>

drivers/net/dsa/mv88e6xxx/Makefile

@@ -15,3 +15,4 @@ mv88e6xxx-objs += port_hidden.o
 mv88e6xxx-$(CONFIG_NET_DSA_MV88E6XXX_PTP) += ptp.o
 mv88e6xxx-objs += serdes.o
 mv88e6xxx-objs += smi.o
+mv88e6xxx-objs += switchdev.o

drivers/net/dsa/mv88e6xxx/chip.c

@@ -42,6 +42,7 @@
 #include "ptp.h"
 #include "serdes.h"
 #include "smi.h"
+#include "switchdev.h"
 
 static void assert_reg_lock(struct mv88e6xxx_chip *chip)
 {
@@ -919,6 +920,13 @@ static void mv88e6xxx_mac_link_down(struct dsa_switch *ds, int port,
 	if (err)
 		dev_err(chip->dev,
 			"p%d: failed to force MAC link down\n", port);
+	else
+		if (mv88e6xxx_port_is_locked(chip, port)) {
+			err = mv88e6xxx_atu_locked_entry_flush(ds, port);
+			if (err)
+				dev_err(chip->dev,
+					"p%d: failed to clear locked entries\n", port);
+		}
 }
 
 static void mv88e6xxx_mac_link_up(struct dsa_switch *ds, int port,
@@ -1685,6 +1693,12 @@ static void mv88e6xxx_port_fast_age(struct dsa_switch *ds, int port)
 	struct mv88e6xxx_chip *chip = ds->priv;
 	int err;
 
+	if (mv88e6xxx_port_is_locked(chip, port))
+		err = mv88e6xxx_atu_locked_entry_flush(ds, port);
+	if (err)
+		dev_err(chip->ds->dev, "p%d: failed to clear locked entries: %d\n",
+			port, err);
+
 	mv88e6xxx_reg_lock(chip);
 	err = mv88e6xxx_port_fast_age_fid(chip, port, 0);
 	mv88e6xxx_reg_unlock(chip);
@@ -1721,11 +1735,11 @@ static int mv88e6xxx_vtu_get(struct mv88e6xxx_chip *chip, u16 vid,
 	return err;
 }
 
-static int mv88e6xxx_vtu_walk(struct mv88e6xxx_chip *chip,
-			      int (*cb)(struct mv88e6xxx_chip *chip,
-					const struct mv88e6xxx_vtu_entry *entry,
-					void *priv),
-			      void *priv)
+int mv88e6xxx_vtu_walk(struct mv88e6xxx_chip *chip,
+		       int (*cb)(struct mv88e6xxx_chip *chip,
+				 const struct mv88e6xxx_vtu_entry *entry,
+				 void *priv),
+		       void *priv)
 {
 	struct mv88e6xxx_vtu_entry entry = {
 		.vid = mv88e6xxx_max_vid(chip),
@@ -2727,6 +2741,9 @@ static int mv88e6xxx_port_fdb_add(struct dsa_switch *ds, int port,
 	if (is_locked)
 		return 0;
 
+	if (mv88e6xxx_port_is_locked(chip, port))
+		mv88e6xxx_atu_locked_entry_find_purge(ds, port, addr, vid);
+
 	mv88e6xxx_reg_lock(chip);
 	err = mv88e6xxx_port_db_load_purge(chip, port, addr, vid,
 					   MV88E6XXX_G1_ATU_DATA_STATE_UC_STATIC);
@@ -2740,12 +2757,17 @@ static int mv88e6xxx_port_fdb_del(struct dsa_switch *ds, int port,
 				  struct dsa_db db)
 {
 	struct mv88e6xxx_chip *chip = ds->priv;
-	int err;
+	bool locked_found = false;
+	int err = 0;
 
-	mv88e6xxx_reg_lock(chip);
-	err = mv88e6xxx_port_db_load_purge(chip, port, addr, vid, 0);
-	mv88e6xxx_reg_unlock(chip);
+	if (mv88e6xxx_port_is_locked(chip, port))
+		locked_found = mv88e6xxx_atu_locked_entry_find_purge(ds, port, addr, vid);
 
+	if (!locked_found) {
+		mv88e6xxx_reg_lock(chip);
+		err = mv88e6xxx_port_db_load_purge(chip, port, addr, vid, 0);
+		mv88e6xxx_reg_unlock(chip);
+	}
 	return err;
 }
 
@@ -3814,11 +3836,18 @@ static int mv88e6xxx_setup(struct dsa_switch *ds)
 
 static int mv88e6xxx_port_setup(struct dsa_switch *ds, int port)
 {
-	return mv88e6xxx_setup_devlink_regions_port(ds, port);
+	int err;
+
+	err = mv88e6xxx_setup_devlink_regions_port(ds, port);
+	if (!err)
+		return mv88e6xxx_init_violation_handler(ds, port);
+
+	return err;
 }
 
 static void mv88e6xxx_port_teardown(struct dsa_switch *ds, int port)
 {
+	mv88e6xxx_teardown_violation_handler(ds, port);
 	mv88e6xxx_teardown_devlink_regions_port(ds, port);
 }
 

drivers/net/dsa/mv88e6xxx/chip.h

@@ -280,6 +280,12 @@ struct mv88e6xxx_port {
 	unsigned int serdes_irq;
 	char serdes_irq_name[64];
 	struct devlink_region *region;
+
+	/* List and maintenance of ATU locked entries */
+	struct mutex ale_list_lock;
+	struct list_head ale_list;
+	struct delayed_work ale_work;
+	int ale_cnt;
 };
 
 enum mv88e6xxx_region_id {
@@ -399,6 +405,9 @@ struct mv88e6xxx_chip {
 	int egress_dest_port;
 	int ingress_dest_port;
 
+	/* Keep the register written age time for easy access */
+	u8 age_time;
+
 	/* Per-port timestamping resources. */
 	struct mv88e6xxx_port_hwtstamp port_hwtstamp[DSA_MAX_PORTS];
 
@@ -803,6 +812,12 @@ static inline void mv88e6xxx_reg_unlock(struct mv88e6xxx_chip *chip)
 	mutex_unlock(&chip->reg_lock);
 }
 
+int mv88e6xxx_vtu_walk(struct mv88e6xxx_chip *chip,
+		       int (*cb)(struct mv88e6xxx_chip *chip,
+				 const struct mv88e6xxx_vtu_entry *entry,
+				 void *priv),
+		       void *priv);
+
 int mv88e6xxx_fid_map(struct mv88e6xxx_chip *chip, unsigned long *bitmap);
 
 #endif /* _MV88E6XXX_CHIP_H */

drivers/net/dsa/mv88e6xxx/global1.h

@@ -136,6 +136,7 @@
 #define MV88E6XXX_G1_ATU_DATA_TRUNK				0x8000
 #define MV88E6XXX_G1_ATU_DATA_TRUNK_ID_MASK			0x00f0
 #define MV88E6XXX_G1_ATU_DATA_PORT_VECTOR_MASK			0x3ff0
+#define MV88E6XXX_G1_ATU_DATA_PORT_VECTOR_NO_EGRESS		0x0000
 #define MV88E6XXX_G1_ATU_DATA_STATE_MASK			0x000f
 #define MV88E6XXX_G1_ATU_DATA_STATE_UC_UNUSED			0x0000
 #define MV88E6XXX_G1_ATU_DATA_STATE_UC_AGE_1_OLDEST		0x0001

drivers/net/dsa/mv88e6xxx/global1_atu.c

@@ -12,6 +12,8 @@
 
 #include "chip.h"
 #include "global1.h"
+#include "port.h"
+#include "switchdev.h"
 
 /* Offset 0x01: ATU FID Register */
 
@@ -54,6 +56,7 @@ int mv88e6xxx_g1_atu_set_age_time(struct mv88e6xxx_chip *chip,
 
 	/* Round to nearest multiple of coeff */
 	age_time = (msecs + coeff / 2) / coeff;
+	chip->age_time = age_time;
 
 	err = mv88e6xxx_g1_read(chip, MV88E6XXX_G1_ATU_CTL, &val);
 	if (err)
@@ -369,6 +372,7 @@ static irqreturn_t mv88e6xxx_g1_atu_prob_irq_thread_fn(int irq, void *dev_id)
 	int spid;
 	int err;
 	u16 val;
+	u16 fid;
 
 	mv88e6xxx_reg_lock(chip);
 
@@ -380,6 +384,10 @@ static irqreturn_t mv88e6xxx_g1_atu_prob_irq_thread_fn(int irq, void *dev_id)
 	if (err)
 		goto out;
 
+	err = mv88e6xxx_g1_read(chip, MV88E6352_G1_ATU_FID, &fid);
+	if (err)
+		goto out;
+
 	err = mv88e6xxx_g1_atu_data_read(chip, &entry);
 	if (err)
 		goto out;
@@ -388,6 +396,8 @@ static irqreturn_t mv88e6xxx_g1_atu_prob_irq_thread_fn(int irq, void *dev_id)
 	if (err)
 		goto out;
 
+	mv88e6xxx_reg_unlock(chip);
+
 	spid = entry.state;
 
 	if (val & MV88E6XXX_G1_ATU_OP_AGE_OUT_VIOLATION) {
@@ -408,6 +418,11 @@ static irqreturn_t mv88e6xxx_g1_atu_prob_irq_thread_fn(int irq, void *dev_id)
 				    "ATU miss violation for %pM portvec %x spid %d\n",
 				    entry.mac, entry.portvec, spid);
 		chip->ports[spid].atu_miss_violation++;
+		if (fid && mv88e6xxx_port_is_locked(chip, spid))
+			err = mv88e6xxx_handle_violation(chip, spid, &entry, fid,
+							 MV88E6XXX_G1_ATU_OP_MISS_VIOLATION);
+		if (err)
+			goto out;
 	}
 
 	if (val & MV88E6XXX_G1_ATU_OP_FULL_VIOLATION) {
@@ -416,7 +431,6 @@ static irqreturn_t mv88e6xxx_g1_atu_prob_irq_thread_fn(int irq, void *dev_id)
 				    entry.mac, entry.portvec, spid);
 		chip->ports[spid].atu_full_violation++;
 	}
-	mv88e6xxx_reg_unlock(chip);
 
 	return IRQ_HANDLED;
 

drivers/net/dsa/mv88e6xxx/port.c

@@ -14,9 +14,11 @@
 #include <linux/phylink.h>
 
 #include "chip.h"
+#include "global1.h"
 #include "global2.h"
 #include "port.h"
 #include "serdes.h"
+#include "switchdev.h"
 
 int mv88e6xxx_port_read(struct mv88e6xxx_chip *chip, int port, int reg,
 			u16 *val)
@@ -1239,6 +1241,17 @@ int mv88e6xxx_port_set_mirror(struct mv88e6xxx_chip *chip, int port,
 	return err;
 }
 
+bool mv88e6xxx_port_is_locked(struct mv88e6xxx_chip *chip, int port)
+{
+	u16 reg;
+
+	mv88e6xxx_reg_lock(chip);
+	mv88e6xxx_port_read(chip, port, MV88E6XXX_PORT_CTL0, &reg);
+	mv88e6xxx_reg_unlock(chip);
+
+	return reg & MV88E6XXX_PORT_CTL0_SA_FILT_DROP_ON_LOCK;
+}
+
 int mv88e6xxx_port_set_lock(struct mv88e6xxx_chip *chip, int port,
 			    bool locked)
 {
@@ -1257,13 +1270,18 @@ int mv88e6xxx_port_set_lock(struct mv88e6xxx_chip *chip, int port,
 	if (err)
 		return err;
 
-	err = mv88e6xxx_port_read(chip, port, MV88E6XXX_PORT_ASSOC_VECTOR, &reg);
-	if (err)
-		return err;
+	if (!locked) {
+		err = mv88e6xxx_atu_locked_entry_flush(chip->ds, port);
+		if (err)
+			return err;
+	}
 
-	reg &= ~MV88E6XXX_PORT_ASSOC_VECTOR_LOCKED_PORT;
-	if (locked)
-		reg |= MV88E6XXX_PORT_ASSOC_VECTOR_LOCKED_PORT;
+	reg = 0;
+	if (locked) {
+		reg = (1 << port);
+		reg |= MV88E6XXX_PORT_ASSOC_VECTOR_IGNORE_WRONG |
+			MV88E6XXX_PORT_ASSOC_VECTOR_LOCKED_PORT;
+	}
 
 	return mv88e6xxx_port_write(chip, port, MV88E6XXX_PORT_ASSOC_VECTOR, reg);
 }

drivers/net/dsa/mv88e6xxx/port.h

@@ -231,6 +231,7 @@
 #define MV88E6XXX_PORT_ASSOC_VECTOR_LOCKED_PORT		0x2000
 #define MV88E6XXX_PORT_ASSOC_VECTOR_IGNORE_WRONG	0x1000
 #define MV88E6XXX_PORT_ASSOC_VECTOR_REFRESH_LOCKED	0x0800
+#define MV88E6XXX_PORT_ASSOC_VECTOR_PAV_MASK		0x07ff
 
 /* Offset 0x0C: Port ATU Control */
 #define MV88E6XXX_PORT_ATU_CTL		0x0c
@@ -374,6 +375,7 @@ int mv88e6xxx_port_set_fid(struct mv88e6xxx_chip *chip, int port, u16 fid);
 int mv88e6xxx_port_get_pvid(struct mv88e6xxx_chip *chip, int port, u16 *pvid);
 int mv88e6xxx_port_set_pvid(struct mv88e6xxx_chip *chip, int port, u16 pvid);
 
+bool mv88e6xxx_port_is_locked(struct mv88e6xxx_chip *chip, int port);
 int mv88e6xxx_port_set_lock(struct mv88e6xxx_chip *chip, int port,
 			    bool locked);