xref: /openbmc/linux/drivers/bluetooth/hci_vhci.c (revision 93dc544c) 
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 #ifndef CONFIG_BT_HCIVHCI_DEBUG
44 #undef  BT_DBG
45 #define BT_DBG(D...)
46 #endif
47 
48 #define VERSION "1.2"
49 
50 static int minor = MISC_DYNAMIC_MINOR;
51 
52 struct vhci_data {
53 	struct hci_dev *hdev;
54 
55 	unsigned long flags;
56 
57 	wait_queue_head_t read_wait;
58 	struct sk_buff_head readq;
59 
60 	struct fasync_struct *fasync;
61 };
62 
63 #define VHCI_FASYNC	0x0010
64 
65 static struct miscdevice vhci_miscdev;
66 
67 static int vhci_open_dev(struct hci_dev *hdev)
68 {
69 	set_bit(HCI_RUNNING, &hdev->flags);
70 
71 	return 0;
72 }
73 
74 static int vhci_close_dev(struct hci_dev *hdev)
75 {
76 	struct vhci_data *data = hdev->driver_data;
77 
78 	if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags))
79 		return 0;
80 
81 	skb_queue_purge(&data->readq);
82 
83 	return 0;
84 }
85 
86 static int vhci_flush(struct hci_dev *hdev)
87 {
88 	struct vhci_data *data = hdev->driver_data;
89 
90 	skb_queue_purge(&data->readq);
91 
92 	return 0;
93 }
94 
95 static int vhci_send_frame(struct sk_buff *skb)
96 {
97 	struct hci_dev* hdev = (struct hci_dev *) skb->dev;
98 	struct vhci_data *data;
99 
100 	if (!hdev) {
101 		BT_ERR("Frame for unknown HCI device (hdev=NULL)");
102 		return -ENODEV;
103 	}
104 
105 	if (!test_bit(HCI_RUNNING, &hdev->flags))
106 		return -EBUSY;
107 
108 	data = hdev->driver_data;
109 
110 	memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);
111 	skb_queue_tail(&data->readq, skb);
112 
113 	if (data->flags & VHCI_FASYNC)
114 		kill_fasync(&data->fasync, SIGIO, POLL_IN);
115 
116 	wake_up_interruptible(&data->read_wait);
117 
118 	return 0;
119 }
120 
121 static void vhci_destruct(struct hci_dev *hdev)
122 {
123 	kfree(hdev->driver_data);
124 }
125 
126 static inline ssize_t vhci_get_user(struct vhci_data *data,
127 					const char __user *buf, size_t count)
128 {
129 	struct sk_buff *skb;
130 
131 	if (count > HCI_MAX_FRAME_SIZE)
132 		return -EINVAL;
133 
134 	skb = bt_skb_alloc(count, GFP_KERNEL);
135 	if (!skb)
136 		return -ENOMEM;
137 
138 	if (copy_from_user(skb_put(skb, count), buf, count)) {
139 		kfree_skb(skb);
140 		return -EFAULT;
141 	}
142 
143 	skb->dev = (void *) data->hdev;
144 	bt_cb(skb)->pkt_type = *((__u8 *) skb->data);
145 	skb_pull(skb, 1);
146 
147 	hci_recv_frame(skb);
148 
149 	return count;
150 }
151 
152 static inline ssize_t vhci_put_user(struct vhci_data *data,
153 			struct sk_buff *skb, char __user *buf, int count)
154 {
155 	char __user *ptr = buf;
156 	int len, total = 0;
157 
158 	len = min_t(unsigned int, skb->len, count);
159 
160 	if (copy_to_user(ptr, skb->data, len))
161 		return -EFAULT;
162 
163 	total += len;
164 
165 	data->hdev->stat.byte_tx += len;
166 
167 	switch (bt_cb(skb)->pkt_type) {
168 	case HCI_COMMAND_PKT:
169 		data->hdev->stat.cmd_tx++;
170 		break;
171 
172 	case HCI_ACLDATA_PKT:
173 		data->hdev->stat.acl_tx++;
174 		break;
175 
176 	case HCI_SCODATA_PKT:
177 		data->hdev->stat.cmd_tx++;
178 		break;
179 	};
180 
181 	return total;
182 }
183 
184 static ssize_t vhci_read(struct file *file,
185 				char __user *buf, size_t count, loff_t *pos)
186 {
187 	DECLARE_WAITQUEUE(wait, current);
188 	struct vhci_data *data = file->private_data;
189 	struct sk_buff *skb;
190 	ssize_t ret = 0;
191 
192 	add_wait_queue(&data->read_wait, &wait);
193 	while (count) {
194 		set_current_state(TASK_INTERRUPTIBLE);
195 
196 		skb = skb_dequeue(&data->readq);
197 		if (!skb) {
198 			if (file->f_flags & O_NONBLOCK) {
199 				ret = -EAGAIN;
200 				break;
201 			}
202 
203 			if (signal_pending(current)) {
204 				ret = -ERESTARTSYS;
205 				break;
206 			}
207 
208 			schedule();
209 			continue;
210 		}
211 
212 		if (access_ok(VERIFY_WRITE, buf, count))
213 			ret = vhci_put_user(data, skb, buf, count);
214 		else
215 			ret = -EFAULT;
216 
217 		kfree_skb(skb);
218 		break;
219 	}
220 	set_current_state(TASK_RUNNING);
221 	remove_wait_queue(&data->read_wait, &wait);
222 
223 	return ret;
224 }
225 
226 static ssize_t vhci_write(struct file *file,
227 			const char __user *buf, size_t count, loff_t *pos)
228 {
229 	struct vhci_data *data = file->private_data;
230 
231 	if (!access_ok(VERIFY_READ, buf, count))
232 		return -EFAULT;
233 
234 	return vhci_get_user(data, buf, count);
235 }
236 
237 static unsigned int vhci_poll(struct file *file, poll_table *wait)
238 {
239 	struct vhci_data *data = file->private_data;
240 
241 	poll_wait(file, &data->read_wait, wait);
242 
243 	if (!skb_queue_empty(&data->readq))
244 		return POLLIN | POLLRDNORM;
245 
246 	return POLLOUT | POLLWRNORM;
247 }
248 
249 static int vhci_ioctl(struct inode *inode, struct file *file,
250 					unsigned int cmd, unsigned long arg)
251 {
252 	return -EINVAL;
253 }
254 
255 static int vhci_open(struct inode *inode, struct file *file)
256 {
257 	struct vhci_data *data;
258 	struct hci_dev *hdev;
259 
260 	data = kzalloc(sizeof(struct vhci_data), GFP_KERNEL);
261 	if (!data)
262 		return -ENOMEM;
263 
264 	skb_queue_head_init(&data->readq);
265 	init_waitqueue_head(&data->read_wait);
266 
267 	lock_kernel();
268 	hdev = hci_alloc_dev();
269 	if (!hdev) {
270 		kfree(data);
271 		unlock_kernel();
272 		return -ENOMEM;
273 	}
274 
275 	data->hdev = hdev;
276 
277 	hdev->type = HCI_VIRTUAL;
278 	hdev->driver_data = data;
279 
280 	hdev->open     = vhci_open_dev;
281 	hdev->close    = vhci_close_dev;
282 	hdev->flush    = vhci_flush;
283 	hdev->send     = vhci_send_frame;
284 	hdev->destruct = vhci_destruct;
285 
286 	hdev->owner = THIS_MODULE;
287 
288 	if (hci_register_dev(hdev) < 0) {
289 		BT_ERR("Can't register HCI device");
290 		kfree(data);
291 		hci_free_dev(hdev);
292 		unlock_kernel();
293 		return -EBUSY;
294 	}
295 
296 	file->private_data = data;
297 	unlock_kernel();
298 
299 	return nonseekable_open(inode, file);
300 }
301 
302 static 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 
318 static int vhci_fasync(int fd, struct file *file, int on)
319 {
320 	struct vhci_data *data = file->private_data;
321 	int err = 0;
322 
323 	lock_kernel();
324 	err = fasync_helper(fd, file, on, &data->fasync);
325 	if (err < 0)
326 		goto out;
327 
328 	if (on)
329 		data->flags |= VHCI_FASYNC;
330 	else
331 		data->flags &= ~VHCI_FASYNC;
332 
333 out:
334 	unlock_kernel();
335 	return err;
336 }
337 
338 static const struct file_operations vhci_fops = {
339 	.owner		= THIS_MODULE,
340 	.read		= vhci_read,
341 	.write		= vhci_write,
342 	.poll		= vhci_poll,
343 	.ioctl		= vhci_ioctl,
344 	.open		= vhci_open,
345 	.release	= vhci_release,
346 	.fasync		= vhci_fasync,
347 };
348 
349 static struct miscdevice vhci_miscdev= {
350 	.name		= "vhci",
351 	.fops		= &vhci_fops,
352 };
353 
354 static int __init vhci_init(void)
355 {
356 	BT_INFO("Virtual HCI driver ver %s", VERSION);
357 
358 	vhci_miscdev.minor = minor;
359 
360 	if (misc_register(&vhci_miscdev) < 0) {
361 		BT_ERR("Can't register misc device with minor %d", minor);
362 		return -EIO;
363 	}
364 
365 	return 0;
366 }
367 
368 static void __exit vhci_exit(void)
369 {
370 	if (misc_deregister(&vhci_miscdev) < 0)
371 		BT_ERR("Can't unregister misc device with minor %d", minor);
372 }
373 
374 module_init(vhci_init);
375 module_exit(vhci_exit);
376 
377 module_param(minor, int, 0444);
378 MODULE_PARM_DESC(minor, "Miscellaneous minor device number");
379 
380 MODULE_AUTHOR("Maxim Krasnyansky <maxk@qualcomm.com>, Marcel Holtmann <marcel@holtmann.org>");
381 MODULE_DESCRIPTION("Bluetooth virtual HCI driver ver " VERSION);
382 MODULE_VERSION(VERSION);
383 MODULE_LICENSE("GPL");
384