[net-next PATCH v2 09/13] leds: trigger: netdev: validate configured netdev

Christian Marangi
2023-05-25T14:55:39Z

From: Andrew Lunn <andrew@lunn.ch>

The netdev which the LED should blink for is configurable in
/sys/class/led/foo/device_name. Ensure when offloading that the
configured netdev is the same as the netdev the LED is associated
with. If it is not, only perform software blinking.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
---
drivers/leds/trigger/ledtrig-netdev.c | 24 ++++++++++++++++++++++--
1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/drivers/leds/trigger/ledtrig-netdev.c b/drivers/leds/trigger/ledtrig-netdev.c
index 8d6381415208..5b59441fc415 100644
--- a/drivers/leds/trigger/ledtrig-netdev.c
+++ b/drivers/leds/trigger/ledtrig-netdev.c
@@ -108,6 +108,24 @@ static bool supports_hw_control(struct led_classdev *led_cdev)
return !strcmp(led_cdev->hw_control_trigger, led_cdev->trigger->name);
}

+/*
+ * Validate the configured netdev is the same as the one associated with
+ * the LED driver in hw control.
+ */
+static bool validate_net_dev(struct led_classdev *led_cdev,
+ struct net_device *net_dev)
+{
+ struct device *dev = led_cdev->hw_control_get_device(led_cdev);
+ struct net_device *ndev;
+
+ if (!dev)
+ return false;
+
+ ndev = to_net_dev(dev);
+
+ return ndev == net_dev;
+}
+
static bool can_hw_control(struct led_netdev_data *trigger_data)
{
unsigned int interval = atomic_read(&trigger_data->interval);
@@ -129,9 +147,11 @@ static bool can_hw_control(struct led_netdev_data *trigger_data)
/*
* net_dev must be set with hw control, otherwise no
* blinking can be happening and there is nothing to
- * offloaded.
+ * offloaded. Additionally, for hw control to be
+ * valid, the configured netdev must be the same as
+ * netdev associated to the LED.
*/
- if (!trigger_data->net_dev)
+ if (!validate_net_dev(led_cdev, trigger_data->net_dev))
return false;

/* Check if the requested mode is supported */
--
2.39.2