hci_vhci.c revision a418b893a6af11ae73c762ed5b76c1bad6dc19d8 
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/smp_lock.h>
32#include <linux/types.h>
33#include <linux/errno.h>
34#include <linux/sched.h>
35#include <linux/poll.h>
36
37#include <linux/skbuff.h>
38#include <linux/miscdevice.h>
39
40#include <net/bluetooth/bluetooth.h>
41#include <net/bluetooth/hci_core.h>
42
43#define VERSION "1.2"
44
45static int minor = MISC_DYNAMIC_MINOR;
46
47struct vhci_data {
48	struct hci_dev *hdev;
49
50	unsigned long flags;
51
52	wait_queue_head_t read_wait;
53	struct sk_buff_head readq;
54
55	struct fasync_struct *fasync;
56};
57
58#define VHCI_FASYNC	0x0010
59
60static struct miscdevice vhci_miscdev;
61
62static int vhci_open_dev(struct hci_dev *hdev)
63{
64	set_bit(HCI_RUNNING, &hdev->flags);
65
66	return 0;
67}
68
69static int vhci_close_dev(struct hci_dev *hdev)
70{
71	struct vhci_data *data = hdev->driver_data;
72
73	if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags))
74		return 0;
75
76	skb_queue_purge(&data->readq);
77
78	return 0;
79}
80
81static int vhci_flush(struct hci_dev *hdev)
82{
83	struct vhci_data *data = hdev->driver_data;
84
85	skb_queue_purge(&data->readq);
86
87	return 0;
88}
89
90static int vhci_send_frame(struct sk_buff *skb)
91{
92	struct hci_dev* hdev = (struct hci_dev *) skb->dev;
93	struct vhci_data *data;
94
95	if (!hdev) {
96		BT_ERR("Frame for unknown HCI device (hdev=NULL)");
97		return -ENODEV;
98	}
99
100	if (!test_bit(HCI_RUNNING, &hdev->flags))
101		return -EBUSY;
102
103	data = hdev->driver_data;
104
105	memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);
106	skb_queue_tail(&data->readq, skb);
107
108	if (data->flags & VHCI_FASYNC)
109		kill_fasync(&data->fasync, SIGIO, POLL_IN);
110
111	wake_up_interruptible(&data->read_wait);
112
113	return 0;
114}
115
116static void vhci_destruct(struct hci_dev *hdev)
117{
118	kfree(hdev->driver_data);
119}
120
121static inline ssize_t vhci_get_user(struct vhci_data *data,
122					const char __user *buf, size_t count)
123{
124	struct sk_buff *skb;
125
126	if (count > HCI_MAX_FRAME_SIZE)
127		return -EINVAL;
128
129	skb = bt_skb_alloc(count, GFP_KERNEL);
130	if (!skb)
131		return -ENOMEM;
132
133	if (copy_from_user(skb_put(skb, count), buf, count)) {
134		kfree_skb(skb);
135		return -EFAULT;
136	}
137
138	skb->dev = (void *) data->hdev;
139	bt_cb(skb)->pkt_type = *((__u8 *) skb->data);
140	skb_pull(skb, 1);
141
142	hci_recv_frame(skb);
143
144	return count;
145}
146
147static inline ssize_t vhci_put_user(struct vhci_data *data,
148			struct sk_buff *skb, char __user *buf, int count)
149{
150	char __user *ptr = buf;
151	int len, total = 0;
152
153	len = min_t(unsigned int, skb->len, count);
154
155	if (copy_to_user(ptr, skb->data, len))
156		return -EFAULT;
157
158	total += len;
159
160	data->hdev->stat.byte_tx += len;
161
162	switch (bt_cb(skb)->pkt_type) {
163	case HCI_COMMAND_PKT:
164		data->hdev->stat.cmd_tx++;
165		break;
166
167	case HCI_ACLDATA_PKT:
168		data->hdev->stat.acl_tx++;
169		break;
170
171	case HCI_SCODATA_PKT:
172		data->hdev->stat.cmd_tx++;
173		break;
174	};
175
176	return total;
177}
178
179static ssize_t vhci_read(struct file *file,
180				char __user *buf, size_t count, loff_t *pos)
181{
182	DECLARE_WAITQUEUE(wait, current);
183	struct vhci_data *data = file->private_data;
184	struct sk_buff *skb;
185	ssize_t ret = 0;
186
187	add_wait_queue(&data->read_wait, &wait);
188	while (count) {
189		set_current_state(TASK_INTERRUPTIBLE);
190
191		skb = skb_dequeue(&data->readq);
192		if (!skb) {
193			if (file->f_flags & O_NONBLOCK) {
194				ret = -EAGAIN;
195				break;
196			}
197
198			if (signal_pending(current)) {
199				ret = -ERESTARTSYS;
200				break;
201			}
202
203			schedule();
204			continue;
205		}
206
207		if (access_ok(VERIFY_WRITE, buf, count))
208			ret = vhci_put_user(data, skb, buf, count);
209		else
210			ret = -EFAULT;
211
212		kfree_skb(skb);
213		break;
214	}
215	set_current_state(TASK_RUNNING);
216	remove_wait_queue(&data->read_wait, &wait);
217
218	return ret;
219}
220
221static ssize_t vhci_write(struct file *file,
222			const char __user *buf, size_t count, loff_t *pos)
223{
224	struct vhci_data *data = file->private_data;
225
226	if (!access_ok(VERIFY_READ, buf, count))
227		return -EFAULT;
228
229	return vhci_get_user(data, buf, count);
230}
231
232static unsigned int vhci_poll(struct file *file, poll_table *wait)
233{
234	struct vhci_data *data = file->private_data;
235
236	poll_wait(file, &data->read_wait, wait);
237
238	if (!skb_queue_empty(&data->readq))
239		return POLLIN | POLLRDNORM;
240
241	return POLLOUT | POLLWRNORM;
242}
243
244static int vhci_ioctl(struct inode *inode, struct file *file,
245					unsigned int cmd, unsigned long arg)
246{
247	return -EINVAL;
248}
249
250static int vhci_open(struct inode *inode, struct file *file)
251{
252	struct vhci_data *data;
253	struct hci_dev *hdev;
254
255	data = kzalloc(sizeof(struct vhci_data), GFP_KERNEL);
256	if (!data)
257		return -ENOMEM;
258
259	skb_queue_head_init(&data->readq);
260	init_waitqueue_head(&data->read_wait);
261
262	lock_kernel();
263	hdev = hci_alloc_dev();
264	if (!hdev) {
265		kfree(data);
266		unlock_kernel();
267		return -ENOMEM;
268	}
269
270	data->hdev = hdev;
271
272	hdev->type = HCI_VIRTUAL;
273	hdev->driver_data = data;
274
275	hdev->open     = vhci_open_dev;
276	hdev->close    = vhci_close_dev;
277	hdev->flush    = vhci_flush;
278	hdev->send     = vhci_send_frame;
279	hdev->destruct = vhci_destruct;
280
281	hdev->owner = THIS_MODULE;
282
283	if (hci_register_dev(hdev) < 0) {
284		BT_ERR("Can't register HCI device");
285		kfree(data);
286		hci_free_dev(hdev);
287		unlock_kernel();
288		return -EBUSY;
289	}
290
291	file->private_data = data;
292	unlock_kernel();
293
294	return nonseekable_open(inode, file);
295}
296
297static int vhci_release(struct inode *inode, struct file *file)
298{
299	struct vhci_data *data = file->private_data;
300	struct hci_dev *hdev = data->hdev;
301
302	if (hci_unregister_dev(hdev) < 0) {
303		BT_ERR("Can't unregister HCI device %s", hdev->name);
304	}
305
306	hci_free_dev(hdev);
307
308	file->private_data = NULL;
309
310	return 0;
311}
312
313static int vhci_fasync(int fd, struct file *file, int on)
314{
315	struct vhci_data *data = file->private_data;
316	int err = 0;
317
318	lock_kernel();
319	err = fasync_helper(fd, file, on, &data->fasync);
320	if (err < 0)
321		goto out;
322
323	if (on)
324		data->flags |= VHCI_FASYNC;
325	else
326		data->flags &= ~VHCI_FASYNC;
327
328out:
329	unlock_kernel();
330	return err;
331}
332
333static const struct file_operations vhci_fops = {
334	.owner		= THIS_MODULE,
335	.read		= vhci_read,
336	.write		= vhci_write,
337	.poll		= vhci_poll,
338	.ioctl		= vhci_ioctl,
339	.open		= vhci_open,
340	.release	= vhci_release,
341	.fasync		= vhci_fasync,
342};
343
344static struct miscdevice vhci_miscdev= {
345	.name		= "vhci",
346	.fops		= &vhci_fops,
347};
348
349static int __init vhci_init(void)
350{
351	BT_INFO("Virtual HCI driver ver %s", VERSION);
352
353	vhci_miscdev.minor = minor;
354
355	if (misc_register(&vhci_miscdev) < 0) {
356		BT_ERR("Can't register misc device with minor %d", minor);
357		return -EIO;
358	}
359
360	return 0;
361}
362
363static void __exit vhci_exit(void)
364{
365	if (misc_deregister(&vhci_miscdev) < 0)
366		BT_ERR("Can't unregister misc device with minor %d", minor);
367}
368
369module_init(vhci_init);
370module_exit(vhci_exit);
371
372module_param(minor, int, 0444);
373MODULE_PARM_DESC(minor, "Miscellaneous minor device number");
374
375MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
376MODULE_DESCRIPTION("Bluetooth virtual HCI driver ver " VERSION);
377MODULE_VERSION(VERSION);
378MODULE_LICENSE("GPL");
379