1/*
2 *
3 *  Bluetooth virtual HCI driver
4 *
5 *  Copyright (C) 2000-2001  Qualcomm Incorporated
6 *  Copyright (C) 2002-2003  Maxim Krasnyansky <maxk@qualcomm.com>
7 *  Copyright (C) 2004-2006  Marcel Holtmann <marcel@holtmann.org>
8 *
9 *
10 *  This program is free software; you can redistribute it and/or modify
11 *  it under the terms of the GNU General Public License as published by
12 *  the Free Software Foundation; either version 2 of the License, or
13 *  (at your option) any later version.
14 *
15 *  This program is distributed in the hope that it will be useful,
16 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
17 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18 *  GNU General Public License for more details.
19 *
20 *  You should have received a copy of the GNU General Public License
21 *  along with this program; if not, write to the Free Software
22 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
23 *
24 */
25
26#include <linux/module.h>
27
28#include <linux/kernel.h>
29#include <linux/init.h>
30#include <linux/slab.h>
31#include <linux/types.h>
32#include <linux/errno.h>
33#include <linux/sched.h>
34#include <linux/poll.h>
35
36#include <linux/skbuff.h>
37#include <linux/miscdevice.h>
38
39#include <net/bluetooth/bluetooth.h>
40#include <net/bluetooth/hci_core.h>
41
42#ifndef CONFIG_BT_HCIVHCI_DEBUG
43#undef  BT_DBG
44#define BT_DBG(D...)
45#endif
46
47#define VERSION "1.2"
48
49static int minor = MISC_DYNAMIC_MINOR;
50
51struct vhci_data {
52	struct hci_dev *hdev;
53
54	unsigned long flags;
55
56	wait_queue_head_t read_wait;
57	struct sk_buff_head readq;
58
59	struct fasync_struct *fasync;
60};
61
62#define VHCI_FASYNC	0x0010
63
64static struct miscdevice vhci_miscdev;
65
66static int vhci_open_dev(struct hci_dev *hdev)
67{
68	set_bit(HCI_RUNNING, &hdev->flags);
69
70	return 0;
71}
72
73static int vhci_close_dev(struct hci_dev *hdev)
74{
75	struct vhci_data *data = hdev->driver_data;
76
77	if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags))
78		return 0;
79
80	skb_queue_purge(&data->readq);
81
82	return 0;
83}
84
85static int vhci_flush(struct hci_dev *hdev)
86{
87	struct vhci_data *data = hdev->driver_data;
88
89	skb_queue_purge(&data->readq);
90
91	return 0;
92}
93
94static int vhci_send_frame(struct sk_buff *skb)
95{
96	struct hci_dev* hdev = (struct hci_dev *) skb->dev;
97	struct vhci_data *data;
98
99	if (!hdev) {
100		BT_ERR("Frame for unknown HCI device (hdev=NULL)");
101		return -ENODEV;
102	}
103
104	if (!test_bit(HCI_RUNNING, &hdev->flags))
105		return -EBUSY;
106
107	data = hdev->driver_data;
108
109	memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);
110	skb_queue_tail(&data->readq, skb);
111
112	if (data->flags & VHCI_FASYNC)
113		kill_fasync(&data->fasync, SIGIO, POLL_IN);
114
115	wake_up_interruptible(&data->read_wait);
116
117	return 0;
118}
119
120static void vhci_destruct(struct hci_dev *hdev)
121{
122	kfree(hdev->driver_data);
123}
124
125static inline ssize_t vhci_get_user(struct vhci_data *data,
126					const char __user *buf, size_t count)
127{
128	struct sk_buff *skb;
129
130	if (count > HCI_MAX_FRAME_SIZE)
131		return -EINVAL;
132
133	skb = bt_skb_alloc(count, GFP_KERNEL);
134	if (!skb)
135		return -ENOMEM;
136
137	if (copy_from_user(skb_put(skb, count), buf, count)) {
138		kfree_skb(skb);
139		return -EFAULT;
140	}
141
142	skb->dev = (void *) data->hdev;
143	bt_cb(skb)->pkt_type = *((__u8 *) skb->data);
144	skb_pull(skb, 1);
145
146	hci_recv_frame(skb);
147
148	return count;
149}
150
151static inline ssize_t vhci_put_user(struct vhci_data *data,
152			struct sk_buff *skb, char __user *buf, int count)
153{
154	char __user *ptr = buf;
155	int len, total = 0;
156
157	len = min_t(unsigned int, skb->len, count);
158
159	if (copy_to_user(ptr, skb->data, len))
160		return -EFAULT;
161
162	total += len;
163
164	data->hdev->stat.byte_tx += len;
165
166	switch (bt_cb(skb)->pkt_type) {
167	case HCI_COMMAND_PKT:
168		data->hdev->stat.cmd_tx++;
169		break;
170
171	case HCI_ACLDATA_PKT:
172		data->hdev->stat.acl_tx++;
173		break;
174
175	case HCI_SCODATA_PKT:
176		data->hdev->stat.cmd_tx++;
177		break;
178	};
179
180	return total;
181}
182
183static loff_t vhci_llseek(struct file *file, loff_t offset, int origin)
184{
185	return -ESPIPE;
186}
187
188static ssize_t vhci_read(struct file *file,
189				char __user *buf, size_t count, loff_t *pos)
190{
191	DECLARE_WAITQUEUE(wait, current);
192	struct vhci_data *data = file->private_data;
193	struct sk_buff *skb;
194	ssize_t ret = 0;
195
196	add_wait_queue(&data->read_wait, &wait);
197	while (count) {
198		set_current_state(TASK_INTERRUPTIBLE);
199
200		skb = skb_dequeue(&data->readq);
201		if (!skb) {
202			if (file->f_flags & O_NONBLOCK) {
203				ret = -EAGAIN;
204				break;
205			}
206
207			if (signal_pending(current)) {
208				ret = -ERESTARTSYS;
209				break;
210			}
211
212			schedule();
213			continue;
214		}
215
216		if (access_ok(VERIFY_WRITE, buf, count))
217			ret = vhci_put_user(data, skb, buf, count);
218		else
219			ret = -EFAULT;
220
221		kfree_skb(skb);
222		break;
223	}
224	set_current_state(TASK_RUNNING);
225	remove_wait_queue(&data->read_wait, &wait);
226
227	return ret;
228}
229
230static ssize_t vhci_write(struct file *file,
231			const char __user *buf, size_t count, loff_t *pos)
232{
233	struct vhci_data *data = file->private_data;
234
235	if (!access_ok(VERIFY_READ, buf, count))
236		return -EFAULT;
237
238	return vhci_get_user(data, buf, count);
239}
240
241static unsigned int vhci_poll(struct file *file, poll_table *wait)
242{
243	struct vhci_data *data = file->private_data;
244
245	poll_wait(file, &data->read_wait, wait);
246
247	if (!skb_queue_empty(&data->readq))
248		return POLLIN | POLLRDNORM;
249
250	return POLLOUT | POLLWRNORM;
251}
252
253static int vhci_ioctl(struct inode *inode, struct file *file,
254					unsigned int cmd, unsigned long arg)
255{
256	return -EINVAL;
257}
258
259static int vhci_open(struct inode *inode, struct file *file)
260{
261	struct vhci_data *data;
262	struct hci_dev *hdev;
263
264	data = kzalloc(sizeof(struct vhci_data), GFP_KERNEL);
265	if (!data)
266		return -ENOMEM;
267
268	skb_queue_head_init(&data->readq);
269	init_waitqueue_head(&data->read_wait);
270
271	hdev = hci_alloc_dev();
272	if (!hdev) {
273		kfree(data);
274		return -ENOMEM;
275	}
276
277	data->hdev = hdev;
278
279	hdev->type = HCI_VIRTUAL;
280	hdev->driver_data = data;
281
282	hdev->open     = vhci_open_dev;
283	hdev->close    = vhci_close_dev;
284	hdev->flush    = vhci_flush;
285	hdev->send     = vhci_send_frame;
286	hdev->destruct = vhci_destruct;
287
288	hdev->owner = THIS_MODULE;
289
290	if (hci_register_dev(hdev) < 0) {
291		BT_ERR("Can't register HCI device");
292		kfree(data);
293		hci_free_dev(hdev);
294		return -EBUSY;
295	}
296
297	file->private_data = data;
298
299	return nonseekable_open(inode, file);
300}
301
302static int vhci_release(struct inode *inode, struct file *file)
303{
304	struct vhci_data *data = file->private_data;
305	struct hci_dev *hdev = data->hdev;
306
307	if (hci_unregister_dev(hdev) < 0) {
308		BT_ERR("Can't unregister HCI device %s", hdev->name);
309	}
310
311	hci_free_dev(hdev);
312
313	file->private_data = NULL;
314
315	return 0;
316}
317
318static int vhci_fasync(int fd, struct file *file, int on)
319{
320	struct vhci_data *data = file->private_data;
321	int err;
322
323	err = fasync_helper(fd, file, on, &data->fasync);
324	if (err < 0)
325		return err;
326
327	if (on)
328		data->flags |= VHCI_FASYNC;
329	else
330		data->flags &= ~VHCI_FASYNC;
331
332	return 0;
333}
334
335static const struct file_operations vhci_fops = {
336	.owner		= THIS_MODULE,
337	.llseek		= vhci_llseek,
338	.read		= vhci_read,
339	.write		= vhci_write,
340	.poll		= vhci_poll,
341	.ioctl		= vhci_ioctl,
342	.open		= vhci_open,
343	.release	= vhci_release,
344	.fasync		= vhci_fasync,
345};
346
347static struct miscdevice vhci_miscdev= {
348	.name		= "vhci",
349	.fops		= &vhci_fops,
350};
351
352static int __init vhci_init(void)
353{
354	BT_INFO("Virtual HCI driver ver %s", VERSION);
355
356	vhci_miscdev.minor = minor;
357
358	if (misc_register(&vhci_miscdev) < 0) {
359		BT_ERR("Can't register misc device with minor %d", minor);
360		return -EIO;
361	}
362
363	return 0;
364}
365
366static void __exit vhci_exit(void)
367{
368	if (misc_deregister(&vhci_miscdev) < 0)
369		BT_ERR("Can't unregister misc device with minor %d", minor);
370}
371
372module_init(vhci_init);
373module_exit(vhci_exit);
374
375module_param(minor, int, 0444);
376MODULE_PARM_DESC(minor, "Miscellaneous minor device number");
377
378MODULE_AUTHOR("Maxim Krasnyansky <maxk@qualcomm.com>, Marcel Holtmann <marcel@holtmann.org>");
379MODULE_DESCRIPTION("Bluetooth virtual HCI driver ver " VERSION);
380MODULE_VERSION(VERSION);
381MODULE_LICENSE("GPL");
382