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 #include <asm/unaligned.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 #define VERSION "1.5"
44
45 static bool amp;
46
47 struct vhci_data {
48 struct hci_dev *hdev;
49
50 wait_queue_head_t read_wait;
51 struct sk_buff_head readq;
52
53 struct mutex open_mutex;
54 struct delayed_work open_timeout;
55 };
56
vhci_open_dev(struct hci_dev * hdev)57 static int vhci_open_dev(struct hci_dev *hdev)
58 {
59 set_bit(HCI_RUNNING, &hdev->flags);
60
61 return 0;
62 }
63
vhci_close_dev(struct hci_dev * hdev)64 static int vhci_close_dev(struct hci_dev *hdev)
65 {
66 struct vhci_data *data = hci_get_drvdata(hdev);
67
68 if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags))
69 return 0;
70
71 skb_queue_purge(&data->readq);
72
73 return 0;
74 }
75
vhci_flush(struct hci_dev * hdev)76 static int vhci_flush(struct hci_dev *hdev)
77 {
78 struct vhci_data *data = hci_get_drvdata(hdev);
79
80 skb_queue_purge(&data->readq);
81
82 return 0;
83 }
84
vhci_send_frame(struct hci_dev * hdev,struct sk_buff * skb)85 static int vhci_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
86 {
87 struct vhci_data *data = hci_get_drvdata(hdev);
88
89 if (!test_bit(HCI_RUNNING, &hdev->flags))
90 return -EBUSY;
91
92 memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);
93 skb_queue_tail(&data->readq, skb);
94
95 wake_up_interruptible(&data->read_wait);
96 return 0;
97 }
98
__vhci_create_device(struct vhci_data * data,__u8 opcode)99 static int __vhci_create_device(struct vhci_data *data, __u8 opcode)
100 {
101 struct hci_dev *hdev;
102 struct sk_buff *skb;
103 __u8 dev_type;
104
105 if (data->hdev)
106 return -EBADFD;
107
108 /* bits 0-1 are dev_type (BR/EDR or AMP) */
109 dev_type = opcode & 0x03;
110
111 if (dev_type != HCI_BREDR && dev_type != HCI_AMP)
112 return -EINVAL;
113
114 /* bits 2-5 are reserved (must be zero) */
115 if (opcode & 0x3c)
116 return -EINVAL;
117
118 skb = bt_skb_alloc(4, GFP_KERNEL);
119 if (!skb)
120 return -ENOMEM;
121
122 hdev = hci_alloc_dev();
123 if (!hdev) {
124 kfree_skb(skb);
125 return -ENOMEM;
126 }
127
128 data->hdev = hdev;
129
130 hdev->bus = HCI_VIRTUAL;
131 hdev->dev_type = dev_type;
132 hci_set_drvdata(hdev, data);
133
134 hdev->open = vhci_open_dev;
135 hdev->close = vhci_close_dev;
136 hdev->flush = vhci_flush;
137 hdev->send = vhci_send_frame;
138
139 /* bit 6 is for external configuration */
140 if (opcode & 0x40)
141 set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);
142
143 /* bit 7 is for raw device */
144 if (opcode & 0x80)
145 set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
146
147 if (hci_register_dev(hdev) < 0) {
148 BT_ERR("Can't register HCI device");
149 hci_free_dev(hdev);
150 data->hdev = NULL;
151 kfree_skb(skb);
152 return -EBUSY;
153 }
154
155 bt_cb(skb)->pkt_type = HCI_VENDOR_PKT;
156
157 *skb_put(skb, 1) = 0xff;
158 *skb_put(skb, 1) = opcode;
159 put_unaligned_le16(hdev->id, skb_put(skb, 2));
160 skb_queue_tail(&data->readq, skb);
161
162 wake_up_interruptible(&data->read_wait);
163 return 0;
164 }
165
vhci_create_device(struct vhci_data * data,__u8 opcode)166 static int vhci_create_device(struct vhci_data *data, __u8 opcode)
167 {
168 int err;
169
170 mutex_lock(&data->open_mutex);
171 err = __vhci_create_device(data, opcode);
172 mutex_unlock(&data->open_mutex);
173
174 return err;
175 }
176
vhci_get_user(struct vhci_data * data,struct iov_iter * from)177 static inline ssize_t vhci_get_user(struct vhci_data *data,
178 struct iov_iter *from)
179 {
180 size_t len = iov_iter_count(from);
181 struct sk_buff *skb;
182 __u8 pkt_type, opcode;
183 int ret;
184
185 if (len < 2 || len > HCI_MAX_FRAME_SIZE)
186 return -EINVAL;
187
188 skb = bt_skb_alloc(len, GFP_KERNEL);
189 if (!skb)
190 return -ENOMEM;
191
192 if (copy_from_iter(skb_put(skb, len), len, from) != len) {
193 kfree_skb(skb);
194 return -EFAULT;
195 }
196
197 pkt_type = *((__u8 *) skb->data);
198 skb_pull(skb, 1);
199
200 switch (pkt_type) {
201 case HCI_EVENT_PKT:
202 case HCI_ACLDATA_PKT:
203 case HCI_SCODATA_PKT:
204 if (!data->hdev) {
205 kfree_skb(skb);
206 return -ENODEV;
207 }
208
209 bt_cb(skb)->pkt_type = pkt_type;
210
211 ret = hci_recv_frame(data->hdev, skb);
212 break;
213
214 case HCI_VENDOR_PKT:
215 cancel_delayed_work_sync(&data->open_timeout);
216
217 opcode = *((__u8 *) skb->data);
218 skb_pull(skb, 1);
219
220 if (skb->len > 0) {
221 kfree_skb(skb);
222 return -EINVAL;
223 }
224
225 kfree_skb(skb);
226
227 ret = vhci_create_device(data, opcode);
228 break;
229
230 default:
231 kfree_skb(skb);
232 return -EINVAL;
233 }
234
235 return (ret < 0) ? ret : len;
236 }
237
vhci_put_user(struct vhci_data * data,struct sk_buff * skb,char __user * buf,int count)238 static inline ssize_t vhci_put_user(struct vhci_data *data,
239 struct sk_buff *skb,
240 char __user *buf, int count)
241 {
242 char __user *ptr = buf;
243 int len;
244
245 len = min_t(unsigned int, skb->len, count);
246
247 if (copy_to_user(ptr, skb->data, len))
248 return -EFAULT;
249
250 if (!data->hdev)
251 return len;
252
253 data->hdev->stat.byte_tx += len;
254
255 switch (bt_cb(skb)->pkt_type) {
256 case HCI_COMMAND_PKT:
257 data->hdev->stat.cmd_tx++;
258 break;
259 case HCI_ACLDATA_PKT:
260 data->hdev->stat.acl_tx++;
261 break;
262 case HCI_SCODATA_PKT:
263 data->hdev->stat.sco_tx++;
264 break;
265 }
266
267 return len;
268 }
269
vhci_read(struct file * file,char __user * buf,size_t count,loff_t * pos)270 static ssize_t vhci_read(struct file *file,
271 char __user *buf, size_t count, loff_t *pos)
272 {
273 struct vhci_data *data = file->private_data;
274 struct sk_buff *skb;
275 ssize_t ret = 0;
276
277 while (count) {
278 skb = skb_dequeue(&data->readq);
279 if (skb) {
280 ret = vhci_put_user(data, skb, buf, count);
281 if (ret < 0)
282 skb_queue_head(&data->readq, skb);
283 else
284 kfree_skb(skb);
285 break;
286 }
287
288 if (file->f_flags & O_NONBLOCK) {
289 ret = -EAGAIN;
290 break;
291 }
292
293 ret = wait_event_interruptible(data->read_wait,
294 !skb_queue_empty(&data->readq));
295 if (ret < 0)
296 break;
297 }
298
299 return ret;
300 }
301
vhci_write(struct kiocb * iocb,struct iov_iter * from)302 static ssize_t vhci_write(struct kiocb *iocb, struct iov_iter *from)
303 {
304 struct file *file = iocb->ki_filp;
305 struct vhci_data *data = file->private_data;
306
307 return vhci_get_user(data, from);
308 }
309
vhci_poll(struct file * file,poll_table * wait)310 static unsigned int vhci_poll(struct file *file, poll_table *wait)
311 {
312 struct vhci_data *data = file->private_data;
313
314 poll_wait(file, &data->read_wait, wait);
315
316 if (!skb_queue_empty(&data->readq))
317 return POLLIN | POLLRDNORM;
318
319 return POLLOUT | POLLWRNORM;
320 }
321
vhci_open_timeout(struct work_struct * work)322 static void vhci_open_timeout(struct work_struct *work)
323 {
324 struct vhci_data *data = container_of(work, struct vhci_data,
325 open_timeout.work);
326
327 vhci_create_device(data, amp ? HCI_AMP : HCI_BREDR);
328 }
329
vhci_open(struct inode * inode,struct file * file)330 static int vhci_open(struct inode *inode, struct file *file)
331 {
332 struct vhci_data *data;
333
334 data = kzalloc(sizeof(struct vhci_data), GFP_KERNEL);
335 if (!data)
336 return -ENOMEM;
337
338 skb_queue_head_init(&data->readq);
339 init_waitqueue_head(&data->read_wait);
340
341 mutex_init(&data->open_mutex);
342 INIT_DELAYED_WORK(&data->open_timeout, vhci_open_timeout);
343
344 file->private_data = data;
345 nonseekable_open(inode, file);
346
347 schedule_delayed_work(&data->open_timeout, msecs_to_jiffies(1000));
348
349 return 0;
350 }
351
vhci_release(struct inode * inode,struct file * file)352 static int vhci_release(struct inode *inode, struct file *file)
353 {
354 struct vhci_data *data = file->private_data;
355 struct hci_dev *hdev;
356
357 cancel_delayed_work_sync(&data->open_timeout);
358
359 hdev = data->hdev;
360
361 if (hdev) {
362 hci_unregister_dev(hdev);
363 hci_free_dev(hdev);
364 }
365
366 skb_queue_purge(&data->readq);
367 file->private_data = NULL;
368 kfree(data);
369
370 return 0;
371 }
372
373 static const struct file_operations vhci_fops = {
374 .owner = THIS_MODULE,
375 .read = vhci_read,
376 .write_iter = vhci_write,
377 .poll = vhci_poll,
378 .open = vhci_open,
379 .release = vhci_release,
380 .llseek = no_llseek,
381 };
382
383 static struct miscdevice vhci_miscdev= {
384 .name = "vhci",
385 .fops = &vhci_fops,
386 .minor = VHCI_MINOR,
387 };
388
vhci_init(void)389 static int __init vhci_init(void)
390 {
391 BT_INFO("Virtual HCI driver ver %s", VERSION);
392
393 return misc_register(&vhci_miscdev);
394 }
395
vhci_exit(void)396 static void __exit vhci_exit(void)
397 {
398 misc_deregister(&vhci_miscdev);
399 }
400
401 module_init(vhci_init);
402 module_exit(vhci_exit);
403
404 module_param(amp, bool, 0644);
405 MODULE_PARM_DESC(amp, "Create AMP controller device");
406
407 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
408 MODULE_DESCRIPTION("Bluetooth virtual HCI driver ver " VERSION);
409 MODULE_VERSION(VERSION);
410 MODULE_LICENSE("GPL");
411 MODULE_ALIAS("devname:vhci");
412 MODULE_ALIAS_MISCDEV(VHCI_MINOR);
413