On 2020-11-25 22:49, Jakub Kicinski wrote:
On Tue, 24 Nov 2020 10:39:35 +0100 Martin Schiller wrote:
This patch allows layer2 (LAPB) to react to netdev events itself and
avoids the detour via layer3 (X.25).
1. Establish layer2 on NETDEV_UP events, if the carrier is already up.
2. Call lapb_disconnect_request() on NETDEV_GOING_DOWN events to
signal
the peer that the connection will go down.
(Only when the carrier is up.)
3. When a NETDEV_DOWN event occur, clear all queues, enter state
LAPB_STATE_0 and stop all timers.
4. The NETDEV_CHANGE event makes it possible to handle carrier loss
and
detection.
In case of Carrier Loss, clear all queues, enter state LAPB_STATE_0
and stop all timers.
In case of Carrier Detection, we start timer t1 on a DCE interface,
and on a DTE interface we change to state LAPB_STATE_1 and start
sending SABM(E).
Signed-off-by: Martin Schiller <ms@xxxxxxxxxx>
+/* Handle device status changes. */
+static int lapb_device_event(struct notifier_block *this, unsigned
long event,
+ void *ptr)
+{
+ struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+ struct lapb_cb *lapb;
+
+ if (!net_eq(dev_net(dev), &init_net))
+ return NOTIFY_DONE;
+
+ if (dev->type == ARPHRD_X25) {
Flip condition, save indentation.
if (dev->type != ARPHRD_X25)
return NOTIFY_DONE;
You can also pull out of all the cases:
lapb = lapb_devtostruct(dev);
if (!lapb)
return NOTIFY_DONE;
right?
+ switch (event) {
+ case NETDEV_UP:
+ lapb_dbg(0, "(%p) Interface up: %s\n", dev,
+ dev->name);
+
+ if (netif_carrier_ok(dev)) {
+ lapb = lapb_devtostruct(dev);
+ if (!lapb)
+ break;
static int __init lapb_init(void)
{
+ register_netdevice_notifier(&lapb_dev_notifier);
This can fail, so:
return register_netdevice_notifier(&lapb_dev_notifier);
return 0;
}
static void __exit lapb_exit(void)
{
WARN_ON(!list_empty(&lapb_list));
+
+ unregister_netdevice_notifier(&lapb_dev_notifier);
}
MODULE_AUTHOR("Jonathan Naylor <g4klx@xxxxxxxxxxxxxxxxx>");
Thanks for your hints! I will send an update.
