xref: /openbmc/linux/drivers/bluetooth/hci_vhci.c (revision 9ce7677c) 
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/config.h>
27 #include <linux/module.h>
28 
29 #include <linux/kernel.h>
30 #include <linux/init.h>
31 #include <linux/slab.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 *vhci = hdev->driver_data;
77 
78 	if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags))
79 		return 0;
80 
81 	skb_queue_purge(&vhci->readq);
82 
83 	return 0;
84 }
85 
86 static int vhci_flush(struct hci_dev *hdev)
87 {
88 	struct vhci_data *vhci = hdev->driver_data;
89 
90 	skb_queue_purge(&vhci->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 *vhci;
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 	vhci = hdev->driver_data;
109 
110 	memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);
111 	skb_queue_tail(&vhci->readq, skb);
112 
113 	if (vhci->flags & VHCI_FASYNC)
114 		kill_fasync(&vhci->fasync, SIGIO, POLL_IN);
115 
116 	wake_up_interruptible(&vhci->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 *vhci,
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 *) vhci->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 *vhci,
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 	vhci->hdev->stat.byte_tx += len;
166 
167 	switch (bt_cb(skb)->pkt_type) {
168 	case HCI_COMMAND_PKT:
169 		vhci->hdev->stat.cmd_tx++;
170 		break;
171 
172 	case HCI_ACLDATA_PKT:
173 		vhci->hdev->stat.acl_tx++;
174 		break;
175 
176 	case HCI_SCODATA_PKT:
177 		vhci->hdev->stat.cmd_tx++;
178 		break;
179 	};
180 
181 	return total;
182 }
183 
184 static loff_t vhci_llseek(struct file * file, loff_t offset, int origin)
185 {
186 	return -ESPIPE;
187 }
188 
189 static ssize_t vhci_read(struct file * file, char __user * buf, size_t count, loff_t *pos)
190 {
191 	DECLARE_WAITQUEUE(wait, current);
192 	struct vhci_data *vhci = file->private_data;
193 	struct sk_buff *skb;
194 	ssize_t ret = 0;
195 
196 	add_wait_queue(&vhci->read_wait, &wait);
197 	while (count) {
198 		set_current_state(TASK_INTERRUPTIBLE);
199 
200 		skb = skb_dequeue(&vhci->readq);
201 		if (!skb) {
202 			if (file->f_flags & O_NONBLOCK) {
203 				ret = -EAGAIN;
204 				break;
205 			}
206 
207 			if (signal_pending(current)) {
208 				ret = -ERESTARTSYS;
209 				break;
210 			}
211 
212 			schedule();
213 			continue;
214 		}
215 
216 		if (access_ok(VERIFY_WRITE, buf, count))
217 			ret = vhci_put_user(vhci, skb, buf, count);
218 		else
219 			ret = -EFAULT;
220 
221 		kfree_skb(skb);
222 		break;
223 	}
224 	set_current_state(TASK_RUNNING);
225 	remove_wait_queue(&vhci->read_wait, &wait);
226 
227 	return ret;
228 }
229 
230 static ssize_t vhci_write(struct file *file,
231 			const char __user *buf, size_t count, loff_t *pos)
232 {
233 	struct vhci_data *vhci = file->private_data;
234 
235 	if (!access_ok(VERIFY_READ, buf, count))
236 		return -EFAULT;
237 
238 	return vhci_get_user(vhci, buf, count);
239 }
240 
241 static unsigned int vhci_poll(struct file *file, poll_table *wait)
242 {
243 	struct vhci_data *vhci = file->private_data;
244 
245 	poll_wait(file, &vhci->read_wait, wait);
246 
247 	if (!skb_queue_empty(&vhci->readq))
248 		return POLLIN | POLLRDNORM;
249 
250 	return POLLOUT | POLLWRNORM;
251 }
252 
253 static int vhci_ioctl(struct inode *inode, struct file *file,
254 					unsigned int cmd, unsigned long arg)
255 {
256 	return -EINVAL;
257 }
258 
259 static int vhci_open(struct inode *inode, struct file *file)
260 {
261 	struct vhci_data *vhci;
262 	struct hci_dev *hdev;
263 
264 	vhci = kzalloc(sizeof(struct vhci_data), GFP_KERNEL);
265 	if (!vhci)
266 		return -ENOMEM;
267 
268 	skb_queue_head_init(&vhci->readq);
269 	init_waitqueue_head(&vhci->read_wait);
270 
271 	hdev = hci_alloc_dev();
272 	if (!hdev) {
273 		kfree(vhci);
274 		return -ENOMEM;
275 	}
276 
277 	vhci->hdev = hdev;
278 
279 	hdev->type = HCI_VHCI;
280 	hdev->driver_data = vhci;
281 	SET_HCIDEV_DEV(hdev, vhci_miscdev.dev);
282 
283 	hdev->open     = vhci_open_dev;
284 	hdev->close    = vhci_close_dev;
285 	hdev->flush    = vhci_flush;
286 	hdev->send     = vhci_send_frame;
287 	hdev->destruct = vhci_destruct;
288 
289 	hdev->owner = THIS_MODULE;
290 
291 	if (hci_register_dev(hdev) < 0) {
292 		BT_ERR("Can't register HCI device");
293 		kfree(vhci);
294 		hci_free_dev(hdev);
295 		return -EBUSY;
296 	}
297 
298 	file->private_data = vhci;
299 
300 	return nonseekable_open(inode, file);
301 }
302 
303 static int vhci_release(struct inode *inode, struct file *file)
304 {
305 	struct vhci_data *vhci = file->private_data;
306 	struct hci_dev *hdev = vhci->hdev;
307 
308 	if (hci_unregister_dev(hdev) < 0) {
309 		BT_ERR("Can't unregister HCI device %s", hdev->name);
310 	}
311 
312 	hci_free_dev(hdev);
313 
314 	file->private_data = NULL;
315 
316 	return 0;
317 }
318 
319 static int vhci_fasync(int fd, struct file *file, int on)
320 {
321 	struct vhci_data *vhci = file->private_data;
322 	int err;
323 
324 	err = fasync_helper(fd, file, on, &vhci->fasync);
325 	if (err < 0)
326 		return err;
327 
328 	if (on)
329 		vhci->flags |= VHCI_FASYNC;
330 	else
331 		vhci->flags &= ~VHCI_FASYNC;
332 
333 	return 0;
334 }
335 
336 static struct file_operations vhci_fops = {
337 	.owner		= THIS_MODULE,
338 	.llseek		= vhci_llseek,
339 	.read		= vhci_read,
340 	.write		= vhci_write,
341 	.poll		= vhci_poll,
342 	.ioctl		= vhci_ioctl,
343 	.open		= vhci_open,
344 	.release	= vhci_release,
345 	.fasync		= vhci_fasync,
346 };
347 
348 static struct miscdevice vhci_miscdev= {
349 	.name		= "vhci",
350 	.fops		= &vhci_fops,
351 };
352 
353 static int __init vhci_init(void)
354 {
355 	BT_INFO("Virtual HCI driver ver %s", VERSION);
356 
357 	vhci_miscdev.minor = minor;
358 
359 	if (misc_register(&vhci_miscdev) < 0) {
360 		BT_ERR("Can't register misc device with minor %d", minor);
361 		return -EIO;
362 	}
363 
364 	return 0;
365 }
366 
367 static void __exit vhci_exit(void)
368 {
369 	if (misc_deregister(&vhci_miscdev) < 0)
370 		BT_ERR("Can't unregister misc device with minor %d", minor);
371 }
372 
373 module_init(vhci_init);
374 module_exit(vhci_exit);
375 
376 module_param(minor, int, 0444);
377 MODULE_PARM_DESC(minor, "Miscellaneous minor device number");
378 
379 MODULE_AUTHOR("Maxim Krasnyansky <maxk@qualcomm.com>, Marcel Holtmann <marcel@holtmann.org>");
380 MODULE_DESCRIPTION("Bluetooth virtual HCI driver ver " VERSION);
381 MODULE_VERSION(VERSION);
382 MODULE_LICENSE("GPL");
383