path: root/net/bluetooth/rfcomm/tty.c

/*
   RFCOMM implementation for Linux Bluetooth stack (BlueZ).
   Copyright (C) 2002 Maxim Krasnyansky <maxk@qualcomm.com>
   Copyright (C) 2002 Marcel Holtmann <marcel@holtmann.org>

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License version 2 as
   published by the Free Software Foundation;

   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
   OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
   IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
   CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
   WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
   ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
   OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

   ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
   COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
   SOFTWARE IS DISCLAIMED.
*/

/*
 * RFCOMM TTY.
 */

#include <linux/module.h>

#include <linux/tty.h>
#include <linux/tty_driver.h>
#include <linux/tty_flip.h>

#include <net/bluetooth/bluetooth.h>
#include <net/bluetooth/hci_core.h>
#include <net/bluetooth/rfcomm.h>

#define RFCOMM_TTY_MAGIC 0x6d02		/* magic number for rfcomm struct */
#define RFCOMM_TTY_PORTS RFCOMM_MAX_DEV	/* whole lotta rfcomm devices */
#define RFCOMM_TTY_MAJOR 216		/* device node major id of the usb/bluetooth.c driver */
#define RFCOMM_TTY_MINOR 0

static DEFINE_MUTEX(rfcomm_ioctl_mutex);
static struct tty_driver *rfcomm_tty_driver;

struct rfcomm_dev {
	struct tty_port		port;
	struct list_head	list;

	char			name[12];
	int			id;
	unsigned long		flags;
	int			err;

	unsigned long		status;		/* don't export to userspace */

	bdaddr_t		src;
	bdaddr_t		dst;
	u8			channel;

	uint			modem_status;

	struct rfcomm_dlc	*dlc;

	struct device		*tty_dev;

	atomic_t		wmem_alloc;

	struct sk_buff_head	pending;
};

static LIST_HEAD(rfcomm_dev_list);
static DEFINE_SPINLOCK(rfcomm_dev_lock);

static void rfcomm_dev_data_ready(struct rfcomm_dlc *dlc, struct sk_buff *skb);
static void rfcomm_dev_state_change(struct rfcomm_dlc *dlc, int err);
static void rfcomm_dev_modem_status(struct rfcomm_dlc *dlc, u8 v24_sig);

/* ---- Device functions ---- */

static void rfcomm_dev_destruct(struct tty_port *port)
{
	struct rfcomm_dev *dev = container_of(port, struct rfcomm_dev, port);
	struct rfcomm_dlc *dlc = dev->dlc;

	BT_DBG("dev %p dlc %p", dev, dlc);

	rfcomm_dlc_lock(dlc);
	/* Detach DLC if it's owned by this dev */
	if (dlc->owner == dev)
		dlc->owner = NULL;
	rfcomm_dlc_unlock(dlc);

	rfcomm_dlc_put(dlc);

	if (dev->tty_dev)
		tty_unregister_device(rfcomm_tty_driver, dev->id);

	spin_lock(&rfcomm_dev_lock);
	list_del(&dev->list);
	spin_unlock(&rfcomm_dev_lock);

	kfree(dev);

	/* It's safe to call module_put() here because socket still
	   holds reference to this module. */
	module_put(THIS_MODULE);
}

/* device-specific initialization: open the dlc */
static int rfcomm_dev_activate(struct tty_port *port, struct tty_struct *tty)
{
	struct rfcomm_dev *dev = container_of(port, struct rfcomm_dev, port);
	int err;

	err = rfcomm_dlc_open(dev->dlc, &dev->src, &dev->dst, dev->channel);
	if (err)
		set_bit(TTY_IO_ERROR, &tty->flags);
	return err;
}

/* we block the open until the dlc->state becomes BT_CONNECTED */
static int rfcomm_dev_carrier_raised(struct tty_port *port)
{
	struct rfcomm_dev *dev = container_of(port, struct rfcomm_dev, port);

	return (dev->dlc->state == BT_CONNECTED);
}

/* device-specific cleanup: close the dlc */
static <