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-rw-r--r--net/lapb/Kconfig4
-rw-r--r--net/lapb/lapb_iface.c155
-rw-r--r--net/lapb/lapb_out.c3
-rw-r--r--net/lapb/lapb_timer.c48
4 files changed, 181 insertions, 29 deletions
diff --git a/net/lapb/Kconfig b/net/lapb/Kconfig
index 6acfc999c952..da87b47f0dff 100644
--- a/net/lapb/Kconfig
+++ b/net/lapb/Kconfig
@@ -5,7 +5,7 @@
config LAPB
tristate "LAPB Data Link Driver"
- ---help---
+ help
Link Access Procedure, Balanced (LAPB) is the data link layer (i.e.
the lower) part of the X.25 protocol. It offers a reliable
connection service to exchange data frames with one other host, and
@@ -15,7 +15,7 @@ config LAPB
currently supports LAPB only over Ethernet connections. If you want
to use LAPB connections over Ethernet, say Y here and to "LAPB over
Ethernet driver" below. Read
- <file:Documentation/networking/lapb-module.txt> for technical
+ <file:Documentation/networking/lapb-module.rst> for technical
details.
To compile this driver as a module, choose M here: the
diff --git a/net/lapb/lapb_iface.c b/net/lapb/lapb_iface.c
index 3c03f6512c5f..0971ca48ba15 100644
--- a/net/lapb/lapb_iface.c
+++ b/net/lapb/lapb_iface.c
@@ -80,11 +80,9 @@ static void __lapb_insert_cb(struct lapb_cb *lapb)
static struct lapb_cb *__lapb_devtostruct(struct net_device *dev)
{
- struct list_head *entry;
struct lapb_cb *lapb, *use = NULL;
- list_for_each(entry, &lapb_list) {
- lapb = list_entry(entry, struct lapb_cb, node);
+ list_for_each_entry(lapb, &lapb_list, node) {
if (lapb->dev == dev) {
use = lapb;
break;
@@ -122,6 +120,8 @@ static struct lapb_cb *lapb_create_cb(void)
timer_setup(&lapb->t1timer, NULL, 0);
timer_setup(&lapb->t2timer, NULL, 0);
+ lapb->t1timer_running = false;
+ lapb->t2timer_running = false;
lapb->t1 = LAPB_DEFAULT_T1;
lapb->t2 = LAPB_DEFAULT_T2;
@@ -129,6 +129,8 @@ static struct lapb_cb *lapb_create_cb(void)
lapb->mode = LAPB_DEFAULT_MODE;
lapb->window = LAPB_DEFAULT_WINDOW;
lapb->state = LAPB_STATE_0;
+
+ spin_lock_init(&lapb->lock);
refcount_set(&lapb->refcnt, 1);
out:
return lapb;
@@ -178,11 +180,23 @@ int lapb_unregister(struct net_device *dev)
goto out;
lapb_put(lapb);
+ /* Wait for other refs to "lapb" to drop */
+ while (refcount_read(&lapb->refcnt) > 2)
+ usleep_range(1, 10);
+
+ spin_lock_bh(&lapb->lock);
+
lapb_stop_t1timer(lapb);
lapb_stop_t2timer(lapb);
lapb_clear_queues(lapb);
+ spin_unlock_bh(&lapb->lock);
+
+ /* Wait for running timers to stop */
+ del_timer_sync(&lapb->t1timer);
+ del_timer_sync(&lapb->t2timer);
+
__lapb_remove_cb(lapb);
lapb_put(lapb);
@@ -201,6 +215,8 @@ int lapb_getparms(struct net_device *dev, struct lapb_parms_struct *parms)
if (!lapb)
goto out;
+ spin_lock_bh(&lapb->lock);
+
parms->t1 = lapb->t1 / HZ;
parms->t2 = lapb->t2 / HZ;
parms->n2 = lapb->n2;
@@ -219,6 +235,7 @@ int lapb_getparms(struct net_device *dev, struct lapb_parms_struct *parms)
else
parms->t2timer = (lapb->t2timer.expires - jiffies) / HZ;
+ spin_unlock_bh(&lapb->lock);
lapb_put(lapb);
rc = LAPB_OK;
out:
@@ -234,6 +251,8 @@ int lapb_setparms(struct net_device *dev, struct lapb_parms_struct *parms)
if (!lapb)
goto out;
+ spin_lock_bh(&lapb->lock);
+
rc = LAPB_INVALUE;
if (parms->t1 < 1 || parms->t2 < 1 || parms->n2 < 1)
goto out_put;
@@ -256,6 +275,7 @@ int lapb_setparms(struct net_device *dev, struct lapb_parms_struct *parms)
rc = LAPB_OK;
out_put:
+ spin_unlock_bh(&lapb->lock);
lapb_put(lapb);
out:
return rc;
@@ -270,6 +290,8 @@ int lapb_connect_request(struct net_device *dev)
if (!lapb)
goto out;
+ spin_lock_bh(&lapb->lock);
+
rc = LAPB_OK;
if (lapb->state == LAPB_STATE_1)
goto out_put;
@@ -285,24 +307,18 @@ int lapb_connect_request(struct net_device *dev)
rc = LAPB_OK;
out_put:
+ spin_unlock_bh(&lapb->lock);
lapb_put(lapb);
out:
return rc;
}
EXPORT_SYMBOL(lapb_connect_request);
-int lapb_disconnect_request(struct net_device *dev)
+static int __lapb_disconnect_request(struct lapb_cb *lapb)
{
- struct lapb_cb *lapb = lapb_devtostruct(dev);
- int rc = LAPB_BADTOKEN;
-
- if (!lapb)
- goto out;
-
switch (lapb->state) {
case LAPB_STATE_0:
- rc = LAPB_NOTCONNECTED;
- goto out_put;
+ return LAPB_NOTCONNECTED;
case LAPB_STATE_1:
lapb_dbg(1, "(%p) S1 TX DISC(1)\n", lapb->dev);
@@ -310,12 +326,10 @@ int lapb_disconnect_request(struct net_device *dev)
lapb_send_control(lapb, LAPB_DISC, LAPB_POLLON, LAPB_COMMAND);
lapb->state = LAPB_STATE_0;
lapb_start_t1timer(lapb);
- rc = LAPB_NOTCONNECTED;
- goto out_put;
+ return LAPB_NOTCONNECTED;
case LAPB_STATE_2:
- rc = LAPB_OK;
- goto out_put;
+ return LAPB_OK;
}
lapb_clear_queues(lapb);
@@ -328,8 +342,22 @@ int lapb_disconnect_request(struct net_device *dev)
lapb_dbg(1, "(%p) S3 DISC(1)\n", lapb->dev);
lapb_dbg(0, "(%p) S3 -> S2\n", lapb->dev);
- rc = LAPB_OK;
-out_put:
+ return LAPB_OK;
+}
+
+int lapb_disconnect_request(struct net_device *dev)
+{
+ struct lapb_cb *lapb = lapb_devtostruct(dev);
+ int rc = LAPB_BADTOKEN;
+
+ if (!lapb)
+ goto out;
+
+ spin_lock_bh(&lapb->lock);
+
+ rc = __lapb_disconnect_request(lapb);
+
+ spin_unlock_bh(&lapb->lock);
lapb_put(lapb);
out:
return rc;
@@ -344,6 +372,8 @@ int lapb_data_request(struct net_device *dev, struct sk_buff *skb)
if (!lapb)
goto out;
+ spin_lock_bh(&lapb->lock);
+
rc = LAPB_NOTCONNECTED;
if (lapb->state != LAPB_STATE_3 && lapb->state != LAPB_STATE_4)
goto out_put;
@@ -352,6 +382,7 @@ int lapb_data_request(struct net_device *dev, struct sk_buff *skb)
lapb_kick(lapb);
rc = LAPB_OK;
out_put:
+ spin_unlock_bh(&lapb->lock);
lapb_put(lapb);
out:
return rc;
@@ -364,7 +395,9 @@ int lapb_data_received(struct net_device *dev, struct sk_buff *skb)
int rc = LAPB_BADTOKEN;
if (lapb) {
+ spin_lock_bh(&lapb->lock);
lapb_data_input(lapb, skb);
+ spin_unlock_bh(&lapb->lock);
lapb_put(lapb);
rc = LAPB_OK;
}
@@ -418,14 +451,98 @@ 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)
+ return NOTIFY_DONE;
+
+ lapb = lapb_devtostruct(dev);
+ if (!lapb)
+ return NOTIFY_DONE;
+
+ spin_lock_bh(&lapb->lock);
+
+ switch (event) {
+ case NETDEV_UP:
+ lapb_dbg(0, "(%p) Interface up: %s\n", dev, dev->name);
+
+ if (netif_carrier_ok(dev)) {
+ lapb_dbg(0, "(%p): Carrier is already up: %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;
+ case NETDEV_GOING_DOWN:
+ if (netif_carrier_ok(dev))
+ __lapb_disconnect_request(lapb);
+ break;
+ case NETDEV_DOWN:
+ 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:
+ if (netif_carrier_ok(dev)) {
+ 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);
+ }
+ }
+ } else {
+ 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);
+ }
+ break;
+ }
+
+ spin_unlock_bh(&lapb->lock);
+ lapb_put(lapb);
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block lapb_dev_notifier = {
+ .notifier_call = lapb_device_event,
+};
+
static int __init lapb_init(void)
{
- return 0;
+ return register_netdevice_notifier(&lapb_dev_notifier);
}
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>");
diff --git a/net/lapb/lapb_out.c b/net/lapb/lapb_out.c
index 7a4d0715d1c3..a966d29c772d 100644
--- a/net/lapb/lapb_out.c
+++ b/net/lapb/lapb_out.c
@@ -82,7 +82,8 @@ void lapb_kick(struct lapb_cb *lapb)
skb = skb_dequeue(&lapb->write_queue);
do {
- if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL) {
+ skbn = skb_copy(skb, GFP_ATOMIC);
+ if (!skbn) {
skb_queue_head(&lapb->write_queue, skb);
break;
}
diff --git a/net/lapb/lapb_timer.c b/net/lapb/lapb_timer.c
index 8f5b17001a07..5be68869064d 100644
--- a/net/lapb/lapb_timer.c
+++ b/net/lapb/lapb_timer.c
@@ -40,6 +40,7 @@ void lapb_start_t1timer(struct lapb_cb *lapb)
lapb->t1timer.function = lapb_t1timer_expiry;
lapb->t1timer.expires = jiffies + lapb->t1;
+ lapb->t1timer_running = true;
add_timer(&lapb->t1timer);
}
@@ -50,46 +51,72 @@ void lapb_start_t2timer(struct lapb_cb *lapb)
lapb->t2timer.function = lapb_t2timer_expiry;
lapb->t2timer.expires = jiffies + lapb->t2;
+ lapb->t2timer_running = true;
add_timer(&lapb->t2timer);
}
void lapb_stop_t1timer(struct lapb_cb *lapb)
{
+ lapb->t1timer_running = false;
del_timer(&lapb->t1timer);
}
void lapb_stop_t2timer(struct lapb_cb *lapb)
{
+ lapb->t2timer_running = false;
del_timer(&lapb->t2timer);
}
int lapb_t1timer_running(struct lapb_cb *lapb)
{
- return timer_pending(&lapb->t1timer);
+ return lapb->t1timer_running;
}
static void lapb_t2timer_expiry(struct timer_list *t)
{
struct lapb_cb *lapb = from_timer(lapb, t, t2timer);
+ spin_lock_bh(&lapb->lock);
+ if (timer_pending(&lapb->t2timer)) /* A new timer has been set up */
+ goto out;
+ if (!lapb->t2timer_running) /* The timer has been stopped */
+ goto out;
+
if (lapb->condition & LAPB_ACK_PENDING_CONDITION) {
lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;
lapb_timeout_response(lapb);
}
+ lapb->t2timer_running = false;
+
+out:
+ spin_unlock_bh(&lapb->lock);
}
static void lapb_t1timer_expiry(struct timer_list *t)
{
struct lapb_cb *lapb = from_timer(lapb, t, t1timer);
+ spin_lock_bh(&lapb->lock);
+ if (timer_pending(&lapb->t1timer)) /* A new timer has been set up */
+ goto out;
+ if (!lapb->t1timer_running) /* The timer has been stopped */
+ goto out;
+
switch (lapb->state) {
/*
- * If we are a DCE, keep going DM .. DM .. DM
+ * If we are a DCE, send DM up to N2 times, then switch to
+ * STATE_1 and send SABM(E).
*/
case LAPB_STATE_0:
- if (lapb->mode & LAPB_DCE)
+ if (lapb->mode & LAPB_DCE &&
+ lapb->n2count != lapb->n2) {
+ lapb->n2count++;
lapb_send_control(lapb, LAPB_DM, LAPB_POLLOFF, LAPB_RESPONSE);
+ } else {
+ lapb->state = LAPB_STATE_1;
+ lapb_establish_data_link(lapb);
+ }
break;
/*
@@ -101,7 +128,8 @@ static void lapb_t1timer_expiry(struct timer_list *t)
lapb->state = LAPB_STATE_0;
lapb_disconnect_indication(lapb, LAPB_TIMEDOUT);
lapb_dbg(0, "(%p) S1 -> S0\n", lapb->dev);
- return;
+ lapb->t1timer_running = false;
+ goto out;
} else {
lapb->n2count++;
if (lapb->mode & LAPB_EXTENDED) {
@@ -125,7 +153,8 @@ static void lapb_t1timer_expiry(struct timer_list *t)
lapb->state = LAPB_STATE_0;
lapb_disconnect_confirmation(lapb, LAPB_TIMEDOUT);
lapb_dbg(0, "(%p) S2 -> S0\n", lapb->dev);
- return;
+ lapb->t1timer_running = false;
+ goto out;
} else {
lapb->n2count++;
lapb_dbg(1, "(%p) S2 TX DISC(1)\n", lapb->dev);
@@ -143,7 +172,8 @@ static void lapb_t1timer_expiry(struct timer_list *t)
lapb_stop_t2timer(lapb);
lapb_disconnect_indication(lapb, LAPB_TIMEDOUT);
lapb_dbg(0, "(%p) S3 -> S0\n", lapb->dev);
- return;
+ lapb->t1timer_running = false;
+ goto out;
} else {
lapb->n2count++;
lapb_requeue_frames(lapb);
@@ -160,7 +190,8 @@ static void lapb_t1timer_expiry(struct timer_list *t)
lapb->state = LAPB_STATE_0;
lapb_disconnect_indication(lapb, LAPB_TIMEDOUT);
lapb_dbg(0, "(%p) S4 -> S0\n", lapb->dev);
- return;
+ lapb->t1timer_running = false;
+ goto out;
} else {
lapb->n2count++;
lapb_transmit_frmr(lapb);
@@ -169,4 +200,7 @@ static void lapb_t1timer_expiry(struct timer_list *t)
}
lapb_start_t1timer(lapb);
+
+out:
+ spin_unlock_bh(&lapb->lock);
}
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.