[PATCH] USBATM: shutdown open connections when disconnected
This patch causes vcc_release_async to be applied to any open
vcc's when the modem is disconnected. This signals a socket
shutdown, letting the socket user know that the game is up.
I wrote this patch because of reports that pppd would keep
connections open forever when the modem is disconnected.
This patch does not fix that problem, but it's a step in the
right direction. It doesn't help because the pppoatm module
doesn't yet monitor state changes on the ATM socket, so simply
never realises that the ATM connection has gone down (meaning
it doesn't tell the ppp layer). But at least there is a socket
state change now. Unfortunately this patch may create problems
for those rare users like me who use routed IP or some other
non-ppp connection method that goes via the ATM ARP daemon: the
daemon is buggy, and with this patch will crash when the modem
is disconnected. Users with a buggy atmarpd can simply restart
it after disconnecting the modem.
Signed-off-by: Duncan Sands <[EMAIL PROTECTED]>
Signed-off-by: Greg Kroah-Hartman <[EMAIL PROTECTED]>
---
commit 0e42a627ec3d8defa0c43cff94b8f2080a070716
tree 5b22c24b224de444ddc6fd9b874a86624d41c227
parent 233c08e0ff303e659a9003d49b15608f59f08a64
author Duncan Sands <[EMAIL PROTECTED]> Fri, 13 Jan 2006 10:05:15 +0100
committer Greg Kroah-Hartman <[EMAIL PROTECTED]> Tue, 31 Jan 2006 17:23:39 -0800
drivers/usb/atm/usbatm.c | 66 +++++++++++++++++++++++++++++++++-------------
drivers/usb/atm/usbatm.h | 1 +
2 files changed, 48 insertions(+), 19 deletions(-)
diff --git a/drivers/usb/atm/usbatm.c b/drivers/usb/atm/usbatm.c
index 3ed5f02..e660a1e 100644
--- a/drivers/usb/atm/usbatm.c
+++ b/drivers/usb/atm/usbatm.c
@@ -602,8 +602,12 @@ static int usbatm_atm_send(struct atm_vc
vdbg("%s called (skb 0x%p, len %u)", __func__, skb, skb->len);
- if (!instance) {
- dbg("%s: NULL data!", __func__);
+ /* racy disconnection check - fine */
+ if (!instance || instance->disconnected) {
+#ifdef DEBUG
+ if (printk_ratelimit())
+ printk(KERN_DEBUG "%s: %s!\n", __func__, instance ?
"disconnected" : "NULL instance");
+#endif
err = -ENODEV;
goto fail;
}
@@ -715,15 +719,19 @@ static int usbatm_atm_proc_read(struct a
atomic_read(&atm_dev->stats.aal5.rx_err),
atomic_read(&atm_dev->stats.aal5.rx_drop));
- if (!left--)
- switch (atm_dev->signal) {
- case ATM_PHY_SIG_FOUND:
- return sprintf(page, "Line up\n");
- case ATM_PHY_SIG_LOST:
- return sprintf(page, "Line down\n");
- default:
- return sprintf(page, "Line state unknown\n");
- }
+ if (!left--) {
+ if (instance->disconnected)
+ return sprintf(page, "Disconnected\n");
+ else
+ switch (atm_dev->signal) {
+ case ATM_PHY_SIG_FOUND:
+ return sprintf(page, "Line up\n");
+ case ATM_PHY_SIG_LOST:
+ return sprintf(page, "Line down\n");
+ default:
+ return sprintf(page, "Line state unknown\n");
+ }
+ }
return 0;
}
@@ -757,6 +765,12 @@ static int usbatm_atm_open(struct atm_vc
down(&instance->serialize); /* vs self, usbatm_atm_close,
usbatm_usb_disconnect */
+ if (instance->disconnected) {
+ atm_dbg(instance, "%s: disconnected!\n", __func__);
+ ret = -ENODEV;
+ goto fail;
+ }
+
if (usbatm_find_vcc(instance, vpi, vci)) {
atm_dbg(instance, "%s: %hd/%d already in use!\n", __func__,
vpi, vci);
ret = -EADDRINUSE;
@@ -845,6 +859,13 @@ static void usbatm_atm_close(struct atm_
static int usbatm_atm_ioctl(struct atm_dev *atm_dev, unsigned int cmd,
void __user * arg)
{
+ struct usbatm_data *instance = atm_dev->dev_data;
+
+ if (!instance || instance->disconnected) {
+ dbg("%s: %s!", __func__, instance ? "disconnected" : "NULL
instance");
+ return -ENODEV;
+ }
+
switch (cmd) {
case ATM_QUERYLOOP:
return put_user(ATM_LM_NONE, (int __user *)arg) ? -EFAULT : 0;
@@ -1129,6 +1150,7 @@ void usbatm_usb_disconnect(struct usb_in
{
struct device *dev = &intf->dev;
struct usbatm_data *instance = usb_get_intfdata(intf);
+ struct usbatm_vcc_data *vcc_data;
int i;
dev_dbg(dev, "%s entered\n", __func__);
@@ -1141,12 +1163,18 @@ void usbatm_usb_disconnect(struct usb_in
usb_set_intfdata(intf, NULL);
down(&instance->serialize);
+ instance->disconnected = 1;
if (instance->thread_pid >= 0)
kill_proc(instance->thread_pid, SIGTERM, 1);
up(&instance->serialize);
wait_for_completion(&instance->thread_exited);
+ down(&instance->serialize);
+ list_for_each_entry(vcc_data, &instance->vcc_list, list)
+ vcc_release_async(vcc_data->vcc, -EPIPE);
+ up(&instance->serialize);
+
tasklet_disable(&instance->rx_channel.tasklet);
tasklet_disable(&instance->tx_channel.tasklet);
@@ -1156,6 +1184,14 @@ void usbatm_usb_disconnect(struct usb_in
del_timer_sync(&instance->rx_channel.delay);
del_timer_sync(&instance->tx_channel.delay);
+ /* turn usbatm_[rt]x_process into something close to a no-op */
+ /* no need to take the spinlock */
+ INIT_LIST_HEAD(&instance->rx_channel.list);
+ INIT_LIST_HEAD(&instance->tx_channel.list);
+
+ tasklet_enable(&instance->rx_channel.tasklet);
+ tasklet_enable(&instance->tx_channel.tasklet);
+
if (instance->atm_dev && instance->driver->atm_stop)
instance->driver->atm_stop(instance, instance->atm_dev);
@@ -1164,14 +1200,6 @@ void usbatm_usb_disconnect(struct usb_in
instance->driver_data = NULL;
- /* turn usbatm_[rt]x_process into noop */
- /* no need to take the spinlock */
- INIT_LIST_HEAD(&instance->rx_channel.list);
- INIT_LIST_HEAD(&instance->tx_channel.list);
-
- tasklet_enable(&instance->rx_channel.tasklet);
- tasklet_enable(&instance->tx_channel.tasklet);
-
for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++) {
kfree(instance->urbs[i]->transfer_buffer);
usb_free_urb(instance->urbs[i]);
diff --git a/drivers/usb/atm/usbatm.h b/drivers/usb/atm/usbatm.h
index 4b923a8..1a31cf8 100644
--- a/drivers/usb/atm/usbatm.h
+++ b/drivers/usb/atm/usbatm.h
@@ -168,6 +168,7 @@ struct usbatm_data {
struct kref refcount;
struct semaphore serialize;
+ int disconnected;
/* heavy init */
int thread_pid;
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