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Commit 0c756914 authored by Martin Schwidefsky's avatar Martin Schwidefsky
Browse files

s390/3270: hangup the 3270 tty after a disconnect 



The disconnect and later reconnect of a 3270 terminal does not do
a tty hangup. The current session is resumed which is a security
issue.

Do a tty hangup after a unit check has been received.

Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 7e36eff1

drivers/s390/char/tty3270.c

+35 −3
Original line number Diff line number Diff line
@@ -92,6 +92,7 @@ struct tty3270 { 
	unsigned char inattr;		/* Visible/invisible input. */

	int throttle, attn;		/* tty throttle/unthrottle. */

	struct tasklet_struct readlet;	/* Tasklet to issue read request. */

	struct tasklet_struct hanglet;	/* Tasklet to hang up the tty. */

	struct kbd_data *kbd;		/* key_maps stuff. */



	/* Escape sequence parsing. */
@@ -645,6 +646,16 @@ tty3270_issue_read(struct tty3270 *tp, int lock) 
	}

}



/*

 * Hang up the tty

 */

static void

tty3270_hangup_tasklet(struct tty3270 *tp)

{

	tty_port_tty_hangup(&tp->port, true);

	raw3270_put_view(&tp->view);

}



/*

 * Switch to the tty view.

 */
@@ -678,11 +689,14 @@ tty3270_irq(struct tty3270 *tp, struct raw3270_request *rq, struct irb *irb) 
	}



	if (rq) {

		if (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK)

		if (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK) {

			rq->rc = -EIO;

		else

			raw3270_get_view(&tp->view);

			tasklet_schedule(&tp->hanglet);

		} else {

			/* Normal end. Copy residual count. */

			rq->rescnt = irb->scsw.cmd.count;

		}

	} else if (irb->scsw.cmd.dstat & DEV_STAT_DEV_END) {

		/* Interrupt without an outstanding request -> update all */

		tp->update_flags = TTY_UPDATE_ALL;
@@ -739,6 +753,9 @@ tty3270_alloc_view(void) 
	tasklet_init(&tp->readlet,

		     (void (*)(unsigned long)) tty3270_read_tasklet,

		     (unsigned long) tp->read);

	tasklet_init(&tp->hanglet,

		     (void (*)(unsigned long)) tty3270_hangup_tasklet,

		     (unsigned long) tp);

	INIT_WORK(&tp->resize_work, tty3270_resize_work);



	return tp;
@@ -1812,7 +1829,22 @@ tty3270_unthrottle(struct tty_struct * tty) 
static void

tty3270_hangup(struct tty_struct *tty)

{

	// FIXME: implement

	struct tty3270 *tp;



	tp = tty->driver_data;

	if (!tp)

		return;

	spin_lock_bh(&tp->view.lock);

	tp->cx = tp->saved_cx = 0;

	tp->cy = tp->saved_cy = 0;

	tp->highlight = tp->saved_highlight = TAX_RESET;

	tp->f_color = tp->saved_f_color = TAC_RESET;

	tty3270_blank_screen(tp);

	while (tp->nr_lines < tp->view.rows - 2)

		tty3270_blank_line(tp);

	tp->update_flags = TTY_UPDATE_ALL;

	spin_unlock_bh(&tp->view.lock);

	tty3270_set_timer(tp, 1);

}



static void