xref: /openbmc/linux/drivers/bluetooth/hci_vhci.c (revision b8bb76713ec50df2f11efee386e16f93d51e1076) 
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 
45 static int minor = MISC_DYNAMIC_MINOR;
46 
47 struct 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 
60 static struct miscdevice vhci_miscdev;
61 
62 static int vhci_open_dev(struct hci_dev *hdev)
63 {
64 	set_bit(HCI_RUNNING, &hdev->flags);
65 
66 	return 0;
67 }
68 
69 static 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 
81 static 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 
90 static 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 
116 static void vhci_destruct(struct hci_dev *hdev)
117 {
118 	kfree(hdev->driver_data);
119 }
120 
121 static 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 
147 static 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 
179 static 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 
221 static 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 
232 static 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 
244 static int vhci_ioctl(struct inode *inode, struct file *file,
245 					unsigned int cmd, unsigned long arg)
246 {
247 	return -EINVAL;
248 }
249 
250 static 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 
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 = 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 
328 out:
329 	unlock_kernel();
330 	return err;
331 }
332 
333 static 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 
344 static struct miscdevice vhci_miscdev= {
345 	.name		= "vhci",
346 	.fops		= &vhci_fops,
347 };
348 
349 static 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 
363 static 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 
369 module_init(vhci_init);
370 module_exit(vhci_exit);
371 
372 module_param(minor, int, 0444);
373 MODULE_PARM_DESC(minor, "Miscellaneous minor device number");
374 
375 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
376 MODULE_DESCRIPTION("Bluetooth virtual HCI driver ver " VERSION);
377 MODULE_VERSION(VERSION);
378 MODULE_LICENSE("GPL");
379