Messages in this thread | | | Date | Thu, 26 Nov 2020 06:57:44 +0100 | From | Martin Schiller <> | Subject | Re: [PATCH net-next v6 2/5] net/lapb: support netdev events |
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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@dev.tdt.de> > >> +/* 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@g4klx.demon.co.uk>");
Thanks for your hints! I will send an update.
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