/*

   *

   *  Bluetooth virtual HCI driver
   *

   *  Copyright (C) 2000-2001  Qualcomm Incorporated
   *  Copyright (C) 2002-2003  Maxim Krasnyansky <maxk@qualcomm.com>
   *  Copyright (C) 2004-2006  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 as published by
   *  the Free Software Foundation; either version 2 of the License, or
   *  (at your option) any later version.
   *
   *  This program is distributed in the hope that it will be useful,
   *  but WITHOUT ANY WARRANTY; without even the implied warranty of
   *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   *  GNU General Public License for more details.
   *
   *  You should have received a copy of the GNU General Public License
   *  along with this program; if not, write to the Free Software
   *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   *

   */

  #include <linux/module.h>

  #include <linux/kernel.h>

  #include <linux/init.h>

  #include <linux/slab.h>

  #include <linux/types.h>
  #include <linux/errno.h>
  #include <linux/sched.h>

  #include <linux/poll.h>

  
  #include <linux/skbuff.h>
  #include <linux/miscdevice.h>

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

  #define VERSION "1.3"

  struct vhci_data {
  	struct hci_dev *hdev;
  
  	unsigned long flags;
  
  	wait_queue_head_t read_wait;
  	struct sk_buff_head readq;

  };

  static int vhci_open_dev(struct hci_dev *hdev)

  {
  	set_bit(HCI_RUNNING, &hdev->flags);

  	return 0;
  }

  static int vhci_close_dev(struct hci_dev *hdev)

  {

  	struct vhci_data *data = hdev->driver_data;

  	if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags))
  		return 0;

  	skb_queue_purge(&data->readq);

  	return 0;
  }

  static int vhci_flush(struct hci_dev *hdev)

  {

  	struct vhci_data *data = hdev->driver_data;

  	skb_queue_purge(&data->readq);

  	return 0;

  }

  static int vhci_send_frame(struct sk_buff *skb)

  {
  	struct hci_dev* hdev = (struct hci_dev *) skb->dev;

  	struct vhci_data *data;

  
  	if (!hdev) {

  		BT_ERR("Frame for unknown HCI device (hdev=NULL)");

  		return -ENODEV;
  	}
  
  	if (!test_bit(HCI_RUNNING, &hdev->flags))
  		return -EBUSY;

  	data = hdev->driver_data;

  	memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);

  	skb_queue_tail(&data->readq, skb);

  	wake_up_interruptible(&data->read_wait);

  
  	return 0;
  }

  static void vhci_destruct(struct hci_dev *hdev)
  {
  	kfree(hdev->driver_data);

  }

  static inline ssize_t vhci_get_user(struct vhci_data *data,

  					const char __user *buf, size_t count)

  {
  	struct sk_buff *skb;
  
  	if (count > HCI_MAX_FRAME_SIZE)
  		return -EINVAL;

  	skb = bt_skb_alloc(count, GFP_KERNEL);
  	if (!skb)

  		return -ENOMEM;

  	if (copy_from_user(skb_put(skb, count), buf, count)) {
  		kfree_skb(skb);
  		return -EFAULT;
  	}

  	skb->dev = (void *) data->hdev;

  	bt_cb(skb)->pkt_type = *((__u8 *) skb->data);

  	skb_pull(skb, 1);
  
  	hci_recv_frame(skb);
  
  	return count;

  }

  static inline ssize_t vhci_put_user(struct vhci_data *data,

  			struct sk_buff *skb, char __user *buf, int count)

  {

  	char __user *ptr = buf;

  	int len, total = 0;
  
  	len = min_t(unsigned int, skb->len, count);

  	if (copy_to_user(ptr, skb->data, len))
  		return -EFAULT;

  	total += len;

  	data->hdev->stat.byte_tx += len;

  	switch (bt_cb(skb)->pkt_type) {
  	case HCI_COMMAND_PKT:

  		data->hdev->stat.cmd_tx++;

  		break;

  	case HCI_ACLDATA_PKT:

  		data->hdev->stat.acl_tx++;

  		break;

  	case HCI_SCODATA_PKT:

  		data->hdev->stat.sco_tx++;

  		break;

  	};
  
  	return total;
  }

  static ssize_t vhci_read(struct file *file,
  				char __user *buf, size_t count, loff_t *pos)

  {

  	struct vhci_data *data = file->private_data;

  	struct sk_buff *skb;
  	ssize_t ret = 0;

  	while (count) {

  		skb = skb_dequeue(&data->readq);

  		if (skb) {
  			ret = vhci_put_user(data, skb, buf, count);
  			if (ret < 0)
  				skb_queue_head(&data->readq, skb);
  			else
  				kfree_skb(skb);
  			break;

  		}

  		if (file->f_flags & O_NONBLOCK) {
  			ret = -EAGAIN;
  			break;
  		}

  		ret = wait_event_interruptible(data->read_wait,
  					!skb_queue_empty(&data->readq));
  		if (ret < 0)
  			break;

  	}

  
  	return ret;
  }

  static ssize_t vhci_write(struct file *file,
  			const char __user *buf, size_t count, loff_t *pos)

  {

  	struct vhci_data *data = file->private_data;

  	return vhci_get_user(data, buf, count);

  }

  static unsigned int vhci_poll(struct file *file, poll_table *wait)

  {

  	struct vhci_data *data = file->private_data;

  	poll_wait(file, &data->read_wait, wait);

  	if (!skb_queue_empty(&data->readq))

  		return POLLIN | POLLRDNORM;
  
  	return POLLOUT | POLLWRNORM;
  }

  static int vhci_open(struct inode *inode, struct file *file)

  {

  	struct vhci_data *data;

  	struct hci_dev *hdev;

  	data = kzalloc(sizeof(struct vhci_data), GFP_KERNEL);
  	if (!data)

  		return -ENOMEM;

  	skb_queue_head_init(&data->readq);
  	init_waitqueue_head(&data->read_wait);

  	hdev = hci_alloc_dev();
  	if (!hdev) {

  		kfree(data);

  		return -ENOMEM;
  	}

  	data->hdev = hdev;

  	hdev->bus = HCI_VIRTUAL;

  	hdev->driver_data = data;

  	hdev->open     = vhci_open_dev;
  	hdev->close    = vhci_close_dev;
  	hdev->flush    = vhci_flush;
  	hdev->send     = vhci_send_frame;
  	hdev->destruct = vhci_destruct;

  
  	hdev->owner = THIS_MODULE;

  	if (hci_register_dev(hdev) < 0) {

  		BT_ERR("Can't register HCI device");

  		kfree(data);

  		hci_free_dev(hdev);
  		return -EBUSY;
  	}

  	file->private_data = data;

  
  	return nonseekable_open(inode, file);

  }

  static int vhci_release(struct inode *inode, struct file *file)

  {

  	struct vhci_data *data = file->private_data;
  	struct hci_dev *hdev = data->hdev;

  
  	if (hci_unregister_dev(hdev) < 0) {
  		BT_ERR("Can't unregister HCI device %s", hdev->name);
  	}
  
  	hci_free_dev(hdev);
  
  	file->private_data = NULL;

  
  	return 0;
  }

  static const struct file_operations vhci_fops = {

  	.owner		= THIS_MODULE,

  	.read		= vhci_read,
  	.write		= vhci_write,
  	.poll		= vhci_poll,

  	.open		= vhci_open,
  	.release	= vhci_release,

  };

  static struct miscdevice vhci_miscdev= {

  	.name	= "vhci",
  	.fops	= &vhci_fops,
  	.minor	= MISC_DYNAMIC_MINOR,

  };

  static int __init vhci_init(void)

  {

  	BT_INFO("Virtual HCI driver ver %s", VERSION);

  	return misc_register(&vhci_miscdev);

  }

  static void __exit vhci_exit(void)

  {

  	misc_deregister(&vhci_miscdev);

  }

  module_init(vhci_init);
  module_exit(vhci_exit);

  MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");

  MODULE_DESCRIPTION("Bluetooth virtual HCI driver ver " VERSION);
  MODULE_VERSION(VERSION);
  MODULE_LICENSE("GPL");