xref: /linux/drivers/bluetooth/hci_vhci.c (revision 14b42963f64b98ab61fa9723c03d71aa5ef4f862) 
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) 2004-2005 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 *vhci = hdev->driver_data;
76 
77 	if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags))
78 		return 0;
79 
80 	skb_queue_purge(&vhci->readq);
81 
82 	return 0;
83 }
84 
85 static int vhci_flush(struct hci_dev *hdev)
86 {
87 	struct vhci_data *vhci = hdev->driver_data;
88 
89 	skb_queue_purge(&vhci->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 *vhci;
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 	vhci = hdev->driver_data;
108 
109 	memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);
110 	skb_queue_tail(&vhci->readq, skb);
111 
112 	if (vhci->flags & VHCI_FASYNC)
113 		kill_fasync(&vhci->fasync, SIGIO, POLL_IN);
114 
115 	wake_up_interruptible(&vhci->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 *vhci,
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 *) vhci->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 *vhci,
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 	vhci->hdev->stat.byte_tx += len;
165 
166 	switch (bt_cb(skb)->pkt_type) {
167 	case HCI_COMMAND_PKT:
168 		vhci->hdev->stat.cmd_tx++;
169 		break;
170 
171 	case HCI_ACLDATA_PKT:
172 		vhci->hdev->stat.acl_tx++;
173 		break;
174 
175 	case HCI_SCODATA_PKT:
176 		vhci->hdev->stat.cmd_tx++;
177 		break;
178 	};
179 
180 	return total;
181 }
182 
183 static loff_t vhci_llseek(struct file * file, loff_t offset, int origin)
184 {
185 	return -ESPIPE;
186 }
187 
188 static ssize_t vhci_read(struct file * file, char __user * buf, size_t count, loff_t *pos)
189 {
190 	DECLARE_WAITQUEUE(wait, current);
191 	struct vhci_data *vhci = file->private_data;
192 	struct sk_buff *skb;
193 	ssize_t ret = 0;
194 
195 	add_wait_queue(&vhci->read_wait, &wait);
196 	while (count) {
197 		set_current_state(TASK_INTERRUPTIBLE);
198 
199 		skb = skb_dequeue(&vhci->readq);
200 		if (!skb) {
201 			if (file->f_flags & O_NONBLOCK) {
202 				ret = -EAGAIN;
203 				break;
204 			}
205 
206 			if (signal_pending(current)) {
207 				ret = -ERESTARTSYS;
208 				break;
209 			}
210 
211 			schedule();
212 			continue;
213 		}
214 
215 		if (access_ok(VERIFY_WRITE, buf, count))
216 			ret = vhci_put_user(vhci, skb, buf, count);
217 		else
218 			ret = -EFAULT;
219 
220 		kfree_skb(skb);
221 		break;
222 	}
223 	set_current_state(TASK_RUNNING);
224 	remove_wait_queue(&vhci->read_wait, &wait);
225 
226 	return ret;
227 }
228 
229 static ssize_t vhci_write(struct file *file,
230 			const char __user *buf, size_t count, loff_t *pos)
231 {
232 	struct vhci_data *vhci = file->private_data;
233 
234 	if (!access_ok(VERIFY_READ, buf, count))
235 		return -EFAULT;
236 
237 	return vhci_get_user(vhci, buf, count);
238 }
239 
240 static unsigned int vhci_poll(struct file *file, poll_table *wait)
241 {
242 	struct vhci_data *vhci = file->private_data;
243 
244 	poll_wait(file, &vhci->read_wait, wait);
245 
246 	if (!skb_queue_empty(&vhci->readq))
247 		return POLLIN | POLLRDNORM;
248 
249 	return POLLOUT | POLLWRNORM;
250 }
251 
252 static int vhci_ioctl(struct inode *inode, struct file *file,
253 					unsigned int cmd, unsigned long arg)
254 {
255 	return -EINVAL;
256 }
257 
258 static int vhci_open(struct inode *inode, struct file *file)
259 {
260 	struct vhci_data *vhci;
261 	struct hci_dev *hdev;
262 
263 	vhci = kzalloc(sizeof(struct vhci_data), GFP_KERNEL);
264 	if (!vhci)
265 		return -ENOMEM;
266 
267 	skb_queue_head_init(&vhci->readq);
268 	init_waitqueue_head(&vhci->read_wait);
269 
270 	hdev = hci_alloc_dev();
271 	if (!hdev) {
272 		kfree(vhci);
273 		return -ENOMEM;
274 	}
275 
276 	vhci->hdev = hdev;
277 
278 	hdev->type = HCI_VHCI;
279 	hdev->driver_data = vhci;
280 
281 	hdev->open     = vhci_open_dev;
282 	hdev->close    = vhci_close_dev;
283 	hdev->flush    = vhci_flush;
284 	hdev->send     = vhci_send_frame;
285 	hdev->destruct = vhci_destruct;
286 
287 	hdev->owner = THIS_MODULE;
288 
289 	if (hci_register_dev(hdev) < 0) {
290 		BT_ERR("Can't register HCI device");
291 		kfree(vhci);
292 		hci_free_dev(hdev);
293 		return -EBUSY;
294 	}
295 
296 	file->private_data = vhci;
297 
298 	return nonseekable_open(inode, file);
299 }
300 
301 static int vhci_release(struct inode *inode, struct file *file)
302 {
303 	struct vhci_data *vhci = file->private_data;
304 	struct hci_dev *hdev = vhci->hdev;
305 
306 	if (hci_unregister_dev(hdev) < 0) {
307 		BT_ERR("Can't unregister HCI device %s", hdev->name);
308 	}
309 
310 	hci_free_dev(hdev);
311 
312 	file->private_data = NULL;
313 
314 	return 0;
315 }
316 
317 static int vhci_fasync(int fd, struct file *file, int on)
318 {
319 	struct vhci_data *vhci = file->private_data;
320 	int err;
321 
322 	err = fasync_helper(fd, file, on, &vhci->fasync);
323 	if (err < 0)
324 		return err;
325 
326 	if (on)
327 		vhci->flags |= VHCI_FASYNC;
328 	else
329 		vhci->flags &= ~VHCI_FASYNC;
330 
331 	return 0;
332 }
333 
334 static struct file_operations vhci_fops = {
335 	.owner		= THIS_MODULE,
336 	.llseek		= vhci_llseek,
337 	.read		= vhci_read,
338 	.write		= vhci_write,
339 	.poll		= vhci_poll,
340 	.ioctl		= vhci_ioctl,
341 	.open		= vhci_open,
342 	.release	= vhci_release,
343 	.fasync		= vhci_fasync,
344 };
345 
346 static struct miscdevice vhci_miscdev= {
347 	.name		= "vhci",
348 	.fops		= &vhci_fops,
349 };
350 
351 static int __init vhci_init(void)
352 {
353 	BT_INFO("Virtual HCI driver ver %s", VERSION);
354 
355 	vhci_miscdev.minor = minor;
356 
357 	if (misc_register(&vhci_miscdev) < 0) {
358 		BT_ERR("Can't register misc device with minor %d", minor);
359 		return -EIO;
360 	}
361 
362 	return 0;
363 }
364 
365 static void __exit vhci_exit(void)
366 {
367 	if (misc_deregister(&vhci_miscdev) < 0)
368 		BT_ERR("Can't unregister misc device with minor %d", minor);
369 }
370 
371 module_init(vhci_init);
372 module_exit(vhci_exit);
373 
374 module_param(minor, int, 0444);
375 MODULE_PARM_DESC(minor, "Miscellaneous minor device number");
376 
377 MODULE_AUTHOR("Maxim Krasnyansky <maxk@qualcomm.com>, Marcel Holtmann <marcel@holtmann.org>");
378 MODULE_DESCRIPTION("Bluetooth virtual HCI driver ver " VERSION);
379 MODULE_VERSION(VERSION);
380 MODULE_LICENSE("GPL");
381