diff mbox series

leds: trigger: netdev: Match net in netdev_trig_notify()

Message ID 20250401085002.492904-1-tobias.junghans@inhub.de
State New
Headers show
Series leds: trigger: netdev: Match net in netdev_trig_notify() | expand

Commit Message

Tobias Junghans April 1, 2025, 8:49 a.m. UTC 
Different network devices may have the same device name if they are in
different network namespaces. This confuses ledtrig-netdev and leads to
undesired effects in certain situations.

When setting device_name to eth0, the trigger is attached to the
corresponding (physical) network device. Later a Docker container is
started. Docker now creates a virtual Ethernet interface (vethXXXX),
moves it to the container's net namespace and renames it to "eth0".
Subsequently ledtrig-netdev receives a NETDEV_CHANGENAME notification,
recognizes "eth0" as device and and switches its activity over to this
device. As a result the LED no longer blinks for the original (physical)
network device.

The described erroneous behavior can be fixed by tracking and comparing
the network namespaces of network devices.

Signed-off-by: Tobias Junghans <tobias.junghans@inhub.de>
---
 drivers/leds/trigger/ledtrig-netdev.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/drivers/leds/trigger/ledtrig-netdev.c b/drivers/leds/trigger/ledtrig-netdev.c
index 4b0863db901a..1d620149c071 100644
--- a/drivers/leds/trigger/ledtrig-netdev.c
+++ b/drivers/leds/trigger/ledtrig-netdev.c
@@ -62,6 +62,7 @@  struct led_netdev_data {
 
 	struct led_classdev *led_cdev;
 	struct net_device *net_dev;
+	struct net *net;
 
 	char device_name[IFNAMSIZ];
 	atomic_t interval;
@@ -274,6 +275,7 @@  static int set_device_name(struct led_netdev_data *trigger_data,
 	if (trigger_data->net_dev) {
 		dev_put(trigger_data->net_dev);
 		trigger_data->net_dev = NULL;
+		trigger_data->net = NULL;
 	}
 
 	memcpy(trigger_data->device_name, name, size);
@@ -284,6 +286,8 @@  static int set_device_name(struct led_netdev_data *trigger_data,
 	if (trigger_data->device_name[0] != 0)
 		trigger_data->net_dev =
 		    dev_get_by_name(&init_net, trigger_data->device_name);
+	if (trigger_data->net_dev)
+		trigger_data->net = dev_net(trigger_data->net_dev);
 
 	trigger_data->carrier_link_up = false;
 	trigger_data->link_speed = SPEED_UNKNOWN;
@@ -573,15 +577,16 @@  static int netdev_trig_notify(struct notifier_block *nb,
 	struct led_netdev_data *trigger_data =
 		container_of(nb, struct led_netdev_data, notifier);
 	struct led_classdev *led_cdev = trigger_data->led_cdev;
+	bool same_net = trigger_data->net == NULL || (dev && net_eq(dev_net(dev), trigger_data->net));
 
 	if (evt != NETDEV_UP && evt != NETDEV_DOWN && evt != NETDEV_CHANGE
 	    && evt != NETDEV_REGISTER && evt != NETDEV_UNREGISTER
 	    && evt != NETDEV_CHANGENAME)
 		return NOTIFY_DONE;
 
-	if (!(dev == trigger_data->net_dev ||
-	      (evt == NETDEV_CHANGENAME && !strcmp(dev->name, trigger_data->device_name)) ||
-	      (evt == NETDEV_REGISTER && !strcmp(dev->name, trigger_data->device_name))))
+	if (!((dev == trigger_data->net_dev && same_net) ||
+	      (evt == NETDEV_CHANGENAME && !strcmp(dev->name, trigger_data->device_name) && same_net) ||
+	      (evt == NETDEV_REGISTER && !strcmp(dev->name, trigger_data->device_name) && same_net)))
 		return NOTIFY_DONE;
 
 	cancel_delayed_work_sync(&trigger_data->work);
@@ -597,12 +602,14 @@  static int netdev_trig_notify(struct notifier_block *nb,
 		dev_put(trigger_data->net_dev);
 		dev_hold(dev);
 		trigger_data->net_dev = dev;
+		trigger_data->net = dev_net(dev);
 		if (evt == NETDEV_CHANGENAME)
 			get_device_state(trigger_data);
 		break;
 	case NETDEV_UNREGISTER:
 		dev_put(trigger_data->net_dev);
 		trigger_data->net_dev = NULL;
+		trigger_data->net = NULL;
 		break;
 	case NETDEV_UP:
 	case NETDEV_CHANGE:
@@ -702,6 +709,7 @@  static int netdev_trig_activate(struct led_classdev *led_cdev)
 
 	trigger_data->led_cdev = led_cdev;
 	trigger_data->net_dev = NULL;
+	trigger_data->net = NULL;
 	trigger_data->device_name[0] = 0;
 
 	trigger_data->mode = 0;