xref: /openbmc/linux/drivers/bluetooth/hci_vhci.c (revision 643d1f7f) 
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 
49 static int minor = MISC_DYNAMIC_MINOR;
50 
51 struct 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 
64 static struct miscdevice vhci_miscdev;
65 
66 static int vhci_open_dev(struct hci_dev *hdev)
67 {
68 	set_bit(HCI_RUNNING, &hdev->flags);
69 
70 	return 0;
71 }
72 
73 static 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 
85 static 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 
94 static 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 
120 static void vhci_destruct(struct hci_dev *hdev)
121 {
122 	kfree(hdev->driver_data);
123 }
124 
125 static 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 
151 static 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 
183 static ssize_t vhci_read(struct file *file,
184 				char __user *buf, size_t count, loff_t *pos)
185 {
186 	DECLARE_WAITQUEUE(wait, current);
187 	struct vhci_data *data = file->private_data;
188 	struct sk_buff *skb;
189 	ssize_t ret = 0;
190 
191 	add_wait_queue(&data->read_wait, &wait);
192 	while (count) {
193 		set_current_state(TASK_INTERRUPTIBLE);
194 
195 		skb = skb_dequeue(&data->readq);
196 		if (!skb) {
197 			if (file->f_flags & O_NONBLOCK) {
198 				ret = -EAGAIN;
199 				break;
200 			}
201 
202 			if (signal_pending(current)) {
203 				ret = -ERESTARTSYS;
204 				break;
205 			}
206 
207 			schedule();
208 			continue;
209 		}
210 
211 		if (access_ok(VERIFY_WRITE, buf, count))
212 			ret = vhci_put_user(data, skb, buf, count);
213 		else
214 			ret = -EFAULT;
215 
216 		kfree_skb(skb);
217 		break;
218 	}
219 	set_current_state(TASK_RUNNING);
220 	remove_wait_queue(&data->read_wait, &wait);
221 
222 	return ret;
223 }
224 
225 static ssize_t vhci_write(struct file *file,
226 			const char __user *buf, size_t count, loff_t *pos)
227 {
228 	struct vhci_data *data = file->private_data;
229 
230 	if (!access_ok(VERIFY_READ, buf, count))
231 		return -EFAULT;
232 
233 	return vhci_get_user(data, buf, count);
234 }
235 
236 static unsigned int vhci_poll(struct file *file, poll_table *wait)
237 {
238 	struct vhci_data *data = file->private_data;
239 
240 	poll_wait(file, &data->read_wait, wait);
241 
242 	if (!skb_queue_empty(&data->readq))
243 		return POLLIN | POLLRDNORM;
244 
245 	return POLLOUT | POLLWRNORM;
246 }
247 
248 static int vhci_ioctl(struct inode *inode, struct file *file,
249 					unsigned int cmd, unsigned long arg)
250 {
251 	return -EINVAL;
252 }
253 
254 static int vhci_open(struct inode *inode, struct file *file)
255 {
256 	struct vhci_data *data;
257 	struct hci_dev *hdev;
258 
259 	data = kzalloc(sizeof(struct vhci_data), GFP_KERNEL);
260 	if (!data)
261 		return -ENOMEM;
262 
263 	skb_queue_head_init(&data->readq);
264 	init_waitqueue_head(&data->read_wait);
265 
266 	hdev = hci_alloc_dev();
267 	if (!hdev) {
268 		kfree(data);
269 		return -ENOMEM;
270 	}
271 
272 	data->hdev = hdev;
273 
274 	hdev->type = HCI_VIRTUAL;
275 	hdev->driver_data = data;
276 
277 	hdev->open     = vhci_open_dev;
278 	hdev->close    = vhci_close_dev;
279 	hdev->flush    = vhci_flush;
280 	hdev->send     = vhci_send_frame;
281 	hdev->destruct = vhci_destruct;
282 
283 	hdev->owner = THIS_MODULE;
284 
285 	if (hci_register_dev(hdev) < 0) {
286 		BT_ERR("Can't register HCI device");
287 		kfree(data);
288 		hci_free_dev(hdev);
289 		return -EBUSY;
290 	}
291 
292 	file->private_data = data;
293 
294 	return nonseekable_open(inode, file);
295 }
296 
297 static 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 
313 static int vhci_fasync(int fd, struct file *file, int on)
314 {
315 	struct vhci_data *data = file->private_data;
316 	int err;
317 
318 	err = fasync_helper(fd, file, on, &data->fasync);
319 	if (err < 0)
320 		return err;
321 
322 	if (on)
323 		data->flags |= VHCI_FASYNC;
324 	else
325 		data->flags &= ~VHCI_FASYNC;
326 
327 	return 0;
328 }
329 
330 static const struct file_operations vhci_fops = {
331 	.owner		= THIS_MODULE,
332 	.read		= vhci_read,
333 	.write		= vhci_write,
334 	.poll		= vhci_poll,
335 	.ioctl		= vhci_ioctl,
336 	.open		= vhci_open,
337 	.release	= vhci_release,
338 	.fasync		= vhci_fasync,
339 };
340 
341 static struct miscdevice vhci_miscdev= {
342 	.name		= "vhci",
343 	.fops		= &vhci_fops,
344 };
345 
346 static int __init vhci_init(void)
347 {
348 	BT_INFO("Virtual HCI driver ver %s", VERSION);
349 
350 	vhci_miscdev.minor = minor;
351 
352 	if (misc_register(&vhci_miscdev) < 0) {
353 		BT_ERR("Can't register misc device with minor %d", minor);
354 		return -EIO;
355 	}
356 
357 	return 0;
358 }
359 
360 static void __exit vhci_exit(void)
361 {
362 	if (misc_deregister(&vhci_miscdev) < 0)
363 		BT_ERR("Can't unregister misc device with minor %d", minor);
364 }
365 
366 module_init(vhci_init);
367 module_exit(vhci_exit);
368 
369 module_param(minor, int, 0444);
370 MODULE_PARM_DESC(minor, "Miscellaneous minor device number");
371 
372 MODULE_AUTHOR("Maxim Krasnyansky <maxk@qualcomm.com>, Marcel Holtmann <marcel@holtmann.org>");
373 MODULE_DESCRIPTION("Bluetooth virtual HCI driver ver " VERSION);
374 MODULE_VERSION(VERSION);
375 MODULE_LICENSE("GPL");
376