From: Martin Schiller <ms@dev.tdt.de>
To: andrew.hendry@gmail.com, davem@davemloft.net, kuba@kernel.org,
xie.he.0141@gmail.com
Cc: linux-x25@vger.kernel.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, Martin Schiller <ms@dev.tdt.de>
Subject: [PATCH net-next v4 2/5] net/lapb: support netdev events
Date: Fri, 20 Nov 2020 06:40:33 +0100 [thread overview]
Message-ID: <20201120054036.15199-3-ms@dev.tdt.de> (raw)
In-Reply-To: <20201120054036.15199-1-ms@dev.tdt.de>
This patch allows layer2 (LAPB) to react to netdev events itself and
avoids the detour via layer3 (X.25).
1. Call lapb_disconnect_request() on NETDEV_GOING_DOWN events.
2. When a NETDEV_DOWN event occur, clear all queues, enter state
LAPB_STATE_0 and stop all timers.
3. 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>
---
net/lapb/lapb_iface.c | 72 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 72 insertions(+)
diff --git a/net/lapb/lapb_iface.c b/net/lapb/lapb_iface.c
index 3c03f6512c5f..52d59984fbe6 100644
--- a/net/lapb/lapb_iface.c
+++ b/net/lapb/lapb_iface.c
@@ -418,14 +418,86 @@ int lapb_data_transmit(struct lapb_cb *lapb, struct sk_buff *skb)
return used;
}
+/* 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) {
+ switch (event) {
+ case NETDEV_GOING_DOWN:
+ lapb_disconnect_request(dev);
+ break;
+ case NETDEV_DOWN:
+ lapb = lapb_devtostruct(dev);
+ if (!lapb)
+ break;
+
+ lapb_dbg(0, "(%p) Interface down: %s\n", dev,
+ dev->name);
+ lapb_dbg(0, "(%p) S%d -> S0\n", dev,
+ lapb->state);
+ lapb_clear_queues(lapb);
+ lapb->state = LAPB_STATE_0;
+ lapb->n2count = 0;
+ lapb_stop_t1timer(lapb);
+ lapb_stop_t2timer(lapb);
+ break;
+ case NETDEV_CHANGE:
+ lapb = lapb_devtostruct(dev);
+ if (!lapb)
+ break;
+
+ if (!netif_carrier_ok(dev)) {
+ lapb_dbg(0, "(%p) Carrier lost: %s\n", dev,
+ dev->name);
+ lapb_dbg(0, "(%p) S%d -> S0\n", dev,
+ lapb->state);
+ lapb_clear_queues(lapb);
+ lapb->state = LAPB_STATE_0;
+ lapb->n2count = 0;
+ lapb_stop_t1timer(lapb);
+ lapb_stop_t2timer(lapb);
+ } else {
+ lapb_dbg(0, "(%p): Carrier detected: %s\n",
+ dev, dev->name);
+ if (lapb->mode & LAPB_DCE) {
+ lapb_start_t1timer(lapb);
+ } else {
+ if (lapb->state == LAPB_STATE_0) {
+ lapb->state = LAPB_STATE_1;
+ lapb_establish_data_link(lapb);
+ }
+ }
+ }
+ break;
+ }
+ }
+
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block lapb_dev_notifier = {
+ .notifier_call = lapb_device_event,
+};
+
static int __init lapb_init(void)
{
+ 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>");
--
2.20.1
next prev parent reply other threads:[~2020-11-20 5:41 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-20 5:40 [PATCH net-next v4 0/5] net/x25: netdev event handling Martin Schiller
2020-11-20 5:40 ` [PATCH net-next v4 1/5] net/x25: handle additional netdev events Martin Schiller
2020-11-20 5:40 ` Martin Schiller [this message]
2020-11-20 23:11 ` [PATCH net-next v4 2/5] net/lapb: support " Xie He
2020-11-20 23:50 ` Xie He
2020-11-23 6:55 ` Martin Schiller
2020-11-23 8:31 ` Xie He
2020-11-23 9:00 ` Martin Schiller
2020-11-23 9:36 ` Xie He
2020-11-23 10:08 ` Xie He
2020-11-23 10:38 ` Martin Schiller
2020-11-23 11:17 ` Xie He
2020-11-23 19:36 ` Jakub Kicinski
2020-11-23 22:09 ` Xie He
2020-11-24 5:29 ` Martin Schiller
2020-11-20 5:40 ` [PATCH net-next v4 3/5] net/lapb: fix t1 timer handling for LAPB_STATE_0 Martin Schiller
2020-11-20 5:40 ` [PATCH net-next v4 4/5] net/x25: fix restart request/confirm handling Martin Schiller
2020-11-20 5:40 ` [PATCH net-next v4 5/5] net/x25: remove x25_kill_by_device() Martin Schiller
2020-11-20 22:40 ` [PATCH net-next v4 0/5] net/x25: netdev event handling Xie He
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