diff mbox series

[v2,net-next,3/4] net: dsa: mv88e6xxx: mac-auth/MAB implementation

Message ID 20220317093902.1305816-4-schultz.hans+netdev@gmail.com
State New
Headers show
Series Extend locked port feature with FDB locked flag (MAC-Auth/MAB) | expand

Commit Message

Hans S March 17, 2022, 9:39 a.m. UTC 
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 is communicated through switchdev to
the bridge module, which adds a fdb entry with the fdb locked
flag set.
Note: The locked port must have learning enabled for the ATU
miss violation to occur.

Signed-off-by: Hans Schultz <schultz.hans+netdev@gmail.com>
---
 drivers/net/dsa/mv88e6xxx/Makefile            |  1 +
 drivers/net/dsa/mv88e6xxx/chip.c              | 10 +--
 drivers/net/dsa/mv88e6xxx/chip.h              |  5 ++
 drivers/net/dsa/mv88e6xxx/global1.h           |  1 +
 drivers/net/dsa/mv88e6xxx/global1_atu.c       | 29 ++++++-
 .../net/dsa/mv88e6xxx/mv88e6xxx_switchdev.c   | 75 +++++++++++++++++++
 .../net/dsa/mv88e6xxx/mv88e6xxx_switchdev.h   | 20 +++++
 drivers/net/dsa/mv88e6xxx/port.c              | 17 ++++-
 drivers/net/dsa/mv88e6xxx/port.h              |  1 +
 9 files changed, 150 insertions(+), 9 deletions(-)
 create mode 100644 drivers/net/dsa/mv88e6xxx/mv88e6xxx_switchdev.c
 create mode 100644 drivers/net/dsa/mv88e6xxx/mv88e6xxx_switchdev.h

Comments

Vladimir Oltean March 17, 2022, 7:27 p.m. UTC | #1 
On Thu, Mar 17, 2022 at 10:39:01AM +0100, Hans Schultz wrote:
> +int mv88e6xxx_switchdev_handle_atu_miss_violation(struct mv88e6xxx_chip *chip,
> +						  int port,
> +						  struct mv88e6xxx_atu_entry *entry,
> +						  u16 fid)
> +{
> +	struct switchdev_notifier_fdb_info info = {
> +		.addr = entry->mac,
> +		.vid = 0,
> +		.added_by_user = false,
> +		.is_local = false,
> +		.offloaded = true,
> +		.locked = true,
> +	};
> +	struct mv88e6xxx_fid_search_ctx ctx;
> +	struct netlink_ext_ack *extack;
> +	struct net_device *brport;
> +	struct dsa_port *dp;
> +	int err;
> +
> +	ctx.fid_search = fid;
> +	err = mv88e6xxx_vtu_walk(chip, mv88e6xxx_find_vid_on_matching_fid, &ctx);
> +	if (err < 0)
> +		return err;
> +	if (err == 1)
> +		info.vid = ctx.vid_found;
> +	else
> +		return -ENODATA;
> +
> +	dp = dsa_to_port(chip->ds, port);
> +	brport = dsa_port_to_bridge_port(dp);
> +	if (!brport)
> +		return -ENODEV;

dsa_port_to_bridge_port() must be under rtnl_lock().

On a different CPU rather than the one servicing the interrupt, the
rtnl_lock is held exactly by the user space command that triggers the
deletion of the bridge port.

The interrupt thread runs, calls dsa_port_to_bridge_port(), and finds
a non-NULL brport, because the bridge is still doing something else in
del_nbp(), it hasn't yet reached the netdev_upper_dev_unlink() function
which will trigger dsa_port_bridge_leave() -> dsa_port_bridge_destroy().

So you continue bravely, and you call rtnl_lock() below. This will block
until the "ip" command finishes. When you acquire the rtnl_lock however,
the brport is no longer valid, because you have waited for the user
space command to finish.

Best case, the bridge port deletion command was "ip link set lan0 nomaster".
So "brport" is "lan0", you call SWITCHDEV_FDB_ADD_TO_BRIDGE, the bridge
doesn't recognize it as a bridge port, says "huh, weird" and carries on.

Worst case, "brport" was an offloaded LAG device which was a bridge
port, and when it got destroyed by "ip link del bond0", the bridge port
got destroyed too. So at this stage, you have a use-after-free because
bond0 no longer exists.

> +
> +	rtnl_lock();
> +	err = call_switchdev_notifiers(SWITCHDEV_FDB_ADD_TO_BRIDGE, brport, &info.info, extack);
> +	if (err)
> +		goto out;
> +	entry->portvec = MV88E6XXX_G1_ATU_DATA_PORT_VECTOR_NO_EGRESS;
> +	err = mv88e6xxx_g1_atu_loadpurge(chip, fid, entry);
> +
> +out:
> +	rtnl_unlock();
> +	return err;
> +}
diff mbox series

Patch

diff --git a/drivers/net/dsa/mv88e6xxx/Makefile b/drivers/net/dsa/mv88e6xxx/Makefile
index c8eca2b6f959..3ca57709730d 100644
--- a/drivers/net/dsa/mv88e6xxx/Makefile
+++ b/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 += mv88e6xxx_switchdev.o
\ No newline at end of file
diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c
index 84b90fc36c58..e1b6bd738085 100644
--- a/drivers/net/dsa/mv88e6xxx/chip.c
+++ b/drivers/net/dsa/mv88e6xxx/chip.c
@@ -1714,11 +1714,11 @@  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),
diff --git a/drivers/net/dsa/mv88e6xxx/chip.h b/drivers/net/dsa/mv88e6xxx/chip.h
index 30b92a265613..64e8fc470fdf 100644
--- a/drivers/net/dsa/mv88e6xxx/chip.h
+++ b/drivers/net/dsa/mv88e6xxx/chip.h
@@ -763,6 +763,11 @@  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 */
diff --git a/drivers/net/dsa/mv88e6xxx/global1.h b/drivers/net/dsa/mv88e6xxx/global1.h
index 2c1607c858a1..729cc0610d9a 100644
--- a/drivers/net/dsa/mv88e6xxx/global1.h
+++ b/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
diff --git a/drivers/net/dsa/mv88e6xxx/global1_atu.c b/drivers/net/dsa/mv88e6xxx/global1_atu.c
index 40bd67a5c8e9..afa54fe8667e 100644
--- a/drivers/net/dsa/mv88e6xxx/global1_atu.c
+++ b/drivers/net/dsa/mv88e6xxx/global1_atu.c
@@ -12,6 +12,8 @@ 
 
 #include "chip.h"
 #include "global1.h"
+#include "port.h"
+#include "mv88e6xxx_switchdev.h"
 
 /* Offset 0x01: ATU FID Register */
 
@@ -114,6 +116,18 @@  static int mv88e6xxx_g1_atu_op_wait(struct mv88e6xxx_chip *chip)
 	return mv88e6xxx_g1_wait_bit(chip, MV88E6XXX_G1_ATU_OP, bit, 0);
 }
 
+static int mv88e6xxx_g1_read_atu_violation(struct mv88e6xxx_chip *chip)
+{
+	int err;
+
+	err = mv88e6xxx_g1_write(chip, MV88E6XXX_G1_ATU_OP,
+				 MV88E6XXX_G1_ATU_OP_BUSY | MV88E6XXX_G1_ATU_OP_GET_CLR_VIOLATION);
+	if (err)
+		return err;
+
+	return mv88e6xxx_g1_atu_op_wait(chip);
+}
+
 static int mv88e6xxx_g1_atu_op(struct mv88e6xxx_chip *chip, u16 fid, u16 op)
 {
 	u16 val;
@@ -356,11 +370,11 @@  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);
 
-	err = mv88e6xxx_g1_atu_op(chip, 0,
-				  MV88E6XXX_G1_ATU_OP_GET_CLR_VIOLATION);
+	err = mv88e6xxx_g1_read_atu_violation(chip);
 	if (err)
 		goto out;
 
@@ -368,6 +382,10 @@  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;
@@ -396,6 +414,13 @@  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 (mv88e6xxx_port_is_locked(chip, chip->ports[spid].port))
+			err = mv88e6xxx_switchdev_handle_atu_miss_violation(chip,
+									    chip->ports[spid].port,
+									    &entry,
+									    fid);
+		if (err)
+			goto out;
 	}
 
 	if (val & MV88E6XXX_G1_ATU_OP_FULL_VIOLATION) {
diff --git a/drivers/net/dsa/mv88e6xxx/mv88e6xxx_switchdev.c b/drivers/net/dsa/mv88e6xxx/mv88e6xxx_switchdev.c
new file mode 100644
index 000000000000..574ae7680720
--- /dev/null
+++ b/drivers/net/dsa/mv88e6xxx/mv88e6xxx_switchdev.c
@@ -0,0 +1,75 @@ 
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * mv88e6xxx_switchdev.c
+ *
+ *	Authors:
+ *	Hans J. Schultz		<hans.schultz@westermo.com>
+ *
+ */
+
+#include <net/switchdev.h>
+#include "chip.h"
+#include "global1.h"
+
+struct mv88e6xxx_fid_search_ctx {
+	u16 fid_search;
+	u16 vid_found;
+};
+
+static int mv88e6xxx_find_vid_on_matching_fid(struct mv88e6xxx_chip *chip,
+					      const struct mv88e6xxx_vtu_entry *entry,
+					      void *priv)
+{
+	struct mv88e6xxx_fid_search_ctx *ctx = priv;
+
+	if (ctx->fid_search == entry->fid) {
+		ctx->vid_found = entry->vid;
+		return 1;
+	}
+	return 0;
+}
+
+int mv88e6xxx_switchdev_handle_atu_miss_violation(struct mv88e6xxx_chip *chip,
+						  int port,
+						  struct mv88e6xxx_atu_entry *entry,
+						  u16 fid)
+{
+	struct switchdev_notifier_fdb_info info = {
+		.addr = entry->mac,
+		.vid = 0,
+		.added_by_user = false,
+		.is_local = false,
+		.offloaded = true,
+		.locked = true,
+	};
+	struct mv88e6xxx_fid_search_ctx ctx;
+	struct netlink_ext_ack *extack;
+	struct net_device *brport;
+	struct dsa_port *dp;
+	int err;
+
+	ctx.fid_search = fid;
+	err = mv88e6xxx_vtu_walk(chip, mv88e6xxx_find_vid_on_matching_fid, &ctx);
+	if (err < 0)
+		return err;
+	if (err == 1)
+		info.vid = ctx.vid_found;
+	else
+		return -ENODATA;
+
+	dp = dsa_to_port(chip->ds, port);
+	brport = dsa_port_to_bridge_port(dp);
+	if (!brport)
+		return -ENODEV;
+
+	rtnl_lock();
+	err = call_switchdev_notifiers(SWITCHDEV_FDB_ADD_TO_BRIDGE, brport, &info.info, extack);
+	if (err)
+		goto out;
+	entry->portvec = MV88E6XXX_G1_ATU_DATA_PORT_VECTOR_NO_EGRESS;
+	err = mv88e6xxx_g1_atu_loadpurge(chip, fid, entry);
+
+out:
+	rtnl_unlock();
+	return err;
+}
diff --git a/drivers/net/dsa/mv88e6xxx/mv88e6xxx_switchdev.h b/drivers/net/dsa/mv88e6xxx/mv88e6xxx_switchdev.h
new file mode 100644
index 000000000000..127f3098f745
--- /dev/null
+++ b/drivers/net/dsa/mv88e6xxx/mv88e6xxx_switchdev.h
@@ -0,0 +1,20 @@ 
+/* SPDX-License-Identifier: GPL-2.0-or-later
+ *
+ * mv88e6xxx_switchdev.h
+ *
+ *	Authors:
+ *	Hans J. Schultz		<hans.schultz@westermo.com>
+ *
+ */
+
+#ifndef DRIVERS_NET_DSA_MV88E6XXX_MV88E6XXX_SWITCHDEV_H_
+#define DRIVERS_NET_DSA_MV88E6XXX_MV88E6XXX_SWITCHDEV_H_
+
+#include <net/switchdev.h>
+
+int mv88e6xxx_switchdev_handle_atu_miss_violation(struct mv88e6xxx_chip *chip,
+						  int port,
+						  struct mv88e6xxx_atu_entry *entry,
+						  u16 fid);
+
+#endif /* DRIVERS_NET_DSA_MV88E6XXX_MV88E6XXX_SWITCHDEV_H_ */
diff --git a/drivers/net/dsa/mv88e6xxx/port.c b/drivers/net/dsa/mv88e6xxx/port.c
index 795b3128768f..4656a6a3e93e 100644
--- a/drivers/net/dsa/mv88e6xxx/port.c
+++ b/drivers/net/dsa/mv88e6xxx/port.c
@@ -1239,6 +1239,17 @@  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;
+
+	if (mv88e6xxx_port_read(chip, port, MV88E6XXX_PORT_CTL0, &reg))
+		return false;
+	if (!(reg & MV88E6XXX_PORT_CTL0_SA_FILT_DROP_ON_LOCK))
+		return false;
+	return true;
+}
+
 int mv88e6xxx_port_set_lock(struct mv88e6xxx_chip *chip, int port,
 			    bool locked)
 {
@@ -1261,9 +1272,11 @@  int mv88e6xxx_port_set_lock(struct mv88e6xxx_chip *chip, int port,
 	if (err)
 		return err;
 
-	reg &= ~MV88E6XXX_PORT_ASSOC_VECTOR_LOCKED_PORT;
+	reg &= ~(MV88E6XXX_PORT_ASSOC_VECTOR_LOCKED_PORT |
+		 MV88E6XXX_PORT_ASSOC_VECTOR_IGNORE_WRONG);
 	if (locked)
-		reg |= MV88E6XXX_PORT_ASSOC_VECTOR_LOCKED_PORT;
+		reg |= MV88E6XXX_PORT_ASSOC_VECTOR_LOCKED_PORT |
+			MV88E6XXX_PORT_ASSOC_VECTOR_IGNORE_WRONG;
 
 	return mv88e6xxx_port_write(chip, port, MV88E6XXX_PORT_ASSOC_VECTOR, reg);
 }
diff --git a/drivers/net/dsa/mv88e6xxx/port.h b/drivers/net/dsa/mv88e6xxx/port.h
index e0a705d82019..09ea8f1615bb 100644
--- a/drivers/net/dsa/mv88e6xxx/port.h
+++ b/drivers/net/dsa/mv88e6xxx/port.h
@@ -374,6 +374,7 @@  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);