[PATCH] ppp: terminate connection on hangup

I reviewed, patched, and tested ppp_async.c to implement
ldisc->hangup().  This correctly terminates the PPP connection on
hangup.

Paul Mackerras already did an excellent job of ensuring safe shutdown
and I/O completion in ldisc->close so the change is trivial: just add
the ldisc->hangup and call the existing close routine.

Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/net/ppp_async.c

@@ -237,6 +237,18 @@ ppp_asynctty_close(struct tty_struct *tty)
 	kfree(ap);
 }
 
+/*
+ * Called on tty hangup in process context.
+ *
+ * Wait for I/O to driver to complete and unregister PPP channel.
+ * This is already done by the close routine, so just call that.
+ */
+static int ppp_asynctty_hangup(struct tty_struct *tty)
+{
+	ppp_asynctty_close(tty);
+	return 0;
+}
+
 /*
  * Read does nothing - no data is ever available this way.
  * Pppd reads and writes packets via /dev/ppp instead.
@@ -380,6 +392,7 @@ static struct tty_ldisc ppp_ldisc = {
 	.name	= "ppp",
 	.open	= ppp_asynctty_open,
 	.close	= ppp_asynctty_close,
+	.hangup	= ppp_asynctty_hangup,
 	.read	= ppp_asynctty_read,
 	.write	= ppp_asynctty_write,
 	.ioctl	= ppp_asynctty_ioctl,