1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 *
4 * Bluetooth virtual HCI driver
5 *
6 * Copyright (C) 2000-2001 Qualcomm Incorporated
7 * Copyright (C) 2002-2003 Maxim Krasnyansky <maxk@qualcomm.com>
8 * Copyright (C) 2004-2006 Marcel Holtmann <marcel@holtmann.org>
9 */
10
11 #include <linux/module.h>
12 #include <asm/unaligned.h>
13
14 #include <linux/kernel.h>
15 #include <linux/init.h>
16 #include <linux/slab.h>
17 #include <linux/types.h>
18 #include <linux/errno.h>
19 #include <linux/sched.h>
20 #include <linux/poll.h>
21
22 #include <linux/skbuff.h>
23 #include <linux/miscdevice.h>
24 #include <linux/debugfs.h>
25
26 #include <net/bluetooth/bluetooth.h>
27 #include <net/bluetooth/hci_core.h>
28
29 #define VERSION "1.5"
30
31 static bool amp;
32
33 struct vhci_data {
34 struct hci_dev *hdev;
35
36 wait_queue_head_t read_wait;
37 struct sk_buff_head readq;
38
39 struct mutex open_mutex;
40 struct delayed_work open_timeout;
41 struct work_struct suspend_work;
42
43 bool suspended;
44 bool wakeup;
45 __u16 msft_opcode;
46 bool aosp_capable;
47 };
48
vhci_open_dev(struct hci_dev * hdev)49 static int vhci_open_dev(struct hci_dev *hdev)
50 {
51 return 0;
52 }
53
vhci_close_dev(struct hci_dev * hdev)54 static int vhci_close_dev(struct hci_dev *hdev)
55 {
56 struct vhci_data *data = hci_get_drvdata(hdev);
57
58 skb_queue_purge(&data->readq);
59
60 return 0;
61 }
62
vhci_flush(struct hci_dev * hdev)63 static int vhci_flush(struct hci_dev *hdev)
64 {
65 struct vhci_data *data = hci_get_drvdata(hdev);
66
67 skb_queue_purge(&data->readq);
68
69 return 0;
70 }
71
vhci_send_frame(struct hci_dev * hdev,struct sk_buff * skb)72 static int vhci_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
73 {
74 struct vhci_data *data = hci_get_drvdata(hdev);
75
76 memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);
77 skb_queue_tail(&data->readq, skb);
78
79 wake_up_interruptible(&data->read_wait);
80 return 0;
81 }
82
vhci_get_data_path_id(struct hci_dev * hdev,u8 * data_path_id)83 static int vhci_get_data_path_id(struct hci_dev *hdev, u8 *data_path_id)
84 {
85 *data_path_id = 0;
86 return 0;
87 }
88
vhci_get_codec_config_data(struct hci_dev * hdev,__u8 type,struct bt_codec * codec,__u8 * vnd_len,__u8 ** vnd_data)89 static int vhci_get_codec_config_data(struct hci_dev *hdev, __u8 type,
90 struct bt_codec *codec, __u8 *vnd_len,
91 __u8 **vnd_data)
92 {
93 if (type != ESCO_LINK)
94 return -EINVAL;
95
96 *vnd_len = 0;
97 *vnd_data = NULL;
98 return 0;
99 }
100
vhci_wakeup(struct hci_dev * hdev)101 static bool vhci_wakeup(struct hci_dev *hdev)
102 {
103 struct vhci_data *data = hci_get_drvdata(hdev);
104
105 return data->wakeup;
106 }
107
force_suspend_read(struct file * file,char __user * user_buf,size_t count,loff_t * ppos)108 static ssize_t force_suspend_read(struct file *file, char __user *user_buf,
109 size_t count, loff_t *ppos)
110 {
111 struct vhci_data *data = file->private_data;
112 char buf[3];
113
114 buf[0] = data->suspended ? 'Y' : 'N';
115 buf[1] = '\n';
116 buf[2] = '\0';
117 return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
118 }
119
vhci_suspend_work(struct work_struct * work)120 static void vhci_suspend_work(struct work_struct *work)
121 {
122 struct vhci_data *data = container_of(work, struct vhci_data,
123 suspend_work);
124
125 if (data->suspended)
126 hci_suspend_dev(data->hdev);
127 else
128 hci_resume_dev(data->hdev);
129 }
130
force_suspend_write(struct file * file,const char __user * user_buf,size_t count,loff_t * ppos)131 static ssize_t force_suspend_write(struct file *file,
132 const char __user *user_buf,
133 size_t count, loff_t *ppos)
134 {
135 struct vhci_data *data = file->private_data;
136 bool enable;
137 int err;
138
139 err = kstrtobool_from_user(user_buf, count, &enable);
140 if (err)
141 return err;
142
143 if (data->suspended == enable)
144 return -EALREADY;
145
146 data->suspended = enable;
147
148 schedule_work(&data->suspend_work);
149
150 return count;
151 }
152
153 static const struct file_operations force_suspend_fops = {
154 .open = simple_open,
155 .read = force_suspend_read,
156 .write = force_suspend_write,
157 .llseek = default_llseek,
158 };
159
force_wakeup_read(struct file * file,char __user * user_buf,size_t count,loff_t * ppos)160 static ssize_t force_wakeup_read(struct file *file, char __user *user_buf,
161 size_t count, loff_t *ppos)
162 {
163 struct vhci_data *data = file->private_data;
164 char buf[3];
165
166 buf[0] = data->wakeup ? 'Y' : 'N';
167 buf[1] = '\n';
168 buf[2] = '\0';
169 return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
170 }
171
force_wakeup_write(struct file * file,const char __user * user_buf,size_t count,loff_t * ppos)172 static ssize_t force_wakeup_write(struct file *file,
173 const char __user *user_buf, size_t count,
174 loff_t *ppos)
175 {
176 struct vhci_data *data = file->private_data;
177 bool enable;
178 int err;
179
180 err = kstrtobool_from_user(user_buf, count, &enable);
181 if (err)
182 return err;
183
184 if (data->wakeup == enable)
185 return -EALREADY;
186
187 data->wakeup = enable;
188
189 return count;
190 }
191
192 static const struct file_operations force_wakeup_fops = {
193 .open = simple_open,
194 .read = force_wakeup_read,
195 .write = force_wakeup_write,
196 .llseek = default_llseek,
197 };
198
msft_opcode_set(void * data,u64 val)199 static int msft_opcode_set(void *data, u64 val)
200 {
201 struct vhci_data *vhci = data;
202
203 if (val > 0xffff || hci_opcode_ogf(val) != 0x3f)
204 return -EINVAL;
205
206 if (vhci->msft_opcode)
207 return -EALREADY;
208
209 vhci->msft_opcode = val;
210
211 return 0;
212 }
213
msft_opcode_get(void * data,u64 * val)214 static int msft_opcode_get(void *data, u64 *val)
215 {
216 struct vhci_data *vhci = data;
217
218 *val = vhci->msft_opcode;
219
220 return 0;
221 }
222
223 DEFINE_DEBUGFS_ATTRIBUTE(msft_opcode_fops, msft_opcode_get, msft_opcode_set,
224 "%llu\n");
225
aosp_capable_read(struct file * file,char __user * user_buf,size_t count,loff_t * ppos)226 static ssize_t aosp_capable_read(struct file *file, char __user *user_buf,
227 size_t count, loff_t *ppos)
228 {
229 struct vhci_data *vhci = file->private_data;
230 char buf[3];
231
232 buf[0] = vhci->aosp_capable ? 'Y' : 'N';
233 buf[1] = '\n';
234 buf[2] = '\0';
235 return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
236 }
237
aosp_capable_write(struct file * file,const char __user * user_buf,size_t count,loff_t * ppos)238 static ssize_t aosp_capable_write(struct file *file,
239 const char __user *user_buf, size_t count,
240 loff_t *ppos)
241 {
242 struct vhci_data *vhci = file->private_data;
243 bool enable;
244 int err;
245
246 err = kstrtobool_from_user(user_buf, count, &enable);
247 if (err)
248 return err;
249
250 if (!enable)
251 return -EINVAL;
252
253 if (vhci->aosp_capable)
254 return -EALREADY;
255
256 vhci->aosp_capable = enable;
257
258 return count;
259 }
260
261 static const struct file_operations aosp_capable_fops = {
262 .open = simple_open,
263 .read = aosp_capable_read,
264 .write = aosp_capable_write,
265 .llseek = default_llseek,
266 };
267
vhci_setup(struct hci_dev * hdev)268 static int vhci_setup(struct hci_dev *hdev)
269 {
270 struct vhci_data *vhci = hci_get_drvdata(hdev);
271
272 if (vhci->msft_opcode)
273 hci_set_msft_opcode(hdev, vhci->msft_opcode);
274
275 if (vhci->aosp_capable)
276 hci_set_aosp_capable(hdev);
277
278 return 0;
279 }
280
__vhci_create_device(struct vhci_data * data,__u8 opcode)281 static int __vhci_create_device(struct vhci_data *data, __u8 opcode)
282 {
283 struct hci_dev *hdev;
284 struct sk_buff *skb;
285 __u8 dev_type;
286
287 if (data->hdev)
288 return -EBADFD;
289
290 /* bits 0-1 are dev_type (Primary or AMP) */
291 dev_type = opcode & 0x03;
292
293 if (dev_type != HCI_PRIMARY && dev_type != HCI_AMP)
294 return -EINVAL;
295
296 /* bits 2-5 are reserved (must be zero) */
297 if (opcode & 0x3c)
298 return -EINVAL;
299
300 skb = bt_skb_alloc(4, GFP_KERNEL);
301 if (!skb)
302 return -ENOMEM;
303
304 hdev = hci_alloc_dev();
305 if (!hdev) {
306 kfree_skb(skb);
307 return -ENOMEM;
308 }
309
310 data->hdev = hdev;
311
312 hdev->bus = HCI_VIRTUAL;
313 hdev->dev_type = dev_type;
314 hci_set_drvdata(hdev, data);
315
316 hdev->open = vhci_open_dev;
317 hdev->close = vhci_close_dev;
318 hdev->flush = vhci_flush;
319 hdev->send = vhci_send_frame;
320 hdev->get_data_path_id = vhci_get_data_path_id;
321 hdev->get_codec_config_data = vhci_get_codec_config_data;
322 hdev->wakeup = vhci_wakeup;
323 hdev->setup = vhci_setup;
324 set_bit(HCI_QUIRK_NON_PERSISTENT_SETUP, &hdev->quirks);
325
326 /* bit 6 is for external configuration */
327 if (opcode & 0x40)
328 set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);
329
330 /* bit 7 is for raw device */
331 if (opcode & 0x80)
332 set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
333
334 set_bit(HCI_QUIRK_VALID_LE_STATES, &hdev->quirks);
335
336 if (hci_register_dev(hdev) < 0) {
337 BT_ERR("Can't register HCI device");
338 hci_free_dev(hdev);
339 data->hdev = NULL;
340 kfree_skb(skb);
341 return -EBUSY;
342 }
343
344 debugfs_create_file("force_suspend", 0644, hdev->debugfs, data,
345 &force_suspend_fops);
346
347 debugfs_create_file("force_wakeup", 0644, hdev->debugfs, data,
348 &force_wakeup_fops);
349
350 if (IS_ENABLED(CONFIG_BT_MSFTEXT))
351 debugfs_create_file("msft_opcode", 0644, hdev->debugfs, data,
352 &msft_opcode_fops);
353
354 if (IS_ENABLED(CONFIG_BT_AOSPEXT))
355 debugfs_create_file("aosp_capable", 0644, hdev->debugfs, data,
356 &aosp_capable_fops);
357
358 hci_skb_pkt_type(skb) = HCI_VENDOR_PKT;
359
360 skb_put_u8(skb, 0xff);
361 skb_put_u8(skb, opcode);
362 put_unaligned_le16(hdev->id, skb_put(skb, 2));
363 skb_queue_tail(&data->readq, skb);
364
365 wake_up_interruptible(&data->read_wait);
366 return 0;
367 }
368
vhci_create_device(struct vhci_data * data,__u8 opcode)369 static int vhci_create_device(struct vhci_data *data, __u8 opcode)
370 {
371 int err;
372
373 mutex_lock(&data->open_mutex);
374 err = __vhci_create_device(data, opcode);
375 mutex_unlock(&data->open_mutex);
376
377 return err;
378 }
379
vhci_get_user(struct vhci_data * data,struct iov_iter * from)380 static inline ssize_t vhci_get_user(struct vhci_data *data,
381 struct iov_iter *from)
382 {
383 size_t len = iov_iter_count(from);
384 struct sk_buff *skb;
385 __u8 pkt_type, opcode;
386 int ret;
387
388 if (len < 2 || len > HCI_MAX_FRAME_SIZE)
389 return -EINVAL;
390
391 skb = bt_skb_alloc(len, GFP_KERNEL);
392 if (!skb)
393 return -ENOMEM;
394
395 if (!copy_from_iter_full(skb_put(skb, len), len, from)) {
396 kfree_skb(skb);
397 return -EFAULT;
398 }
399
400 pkt_type = *((__u8 *) skb->data);
401 skb_pull(skb, 1);
402
403 switch (pkt_type) {
404 case HCI_EVENT_PKT:
405 case HCI_ACLDATA_PKT:
406 case HCI_SCODATA_PKT:
407 case HCI_ISODATA_PKT:
408 if (!data->hdev) {
409 kfree_skb(skb);
410 return -ENODEV;
411 }
412
413 hci_skb_pkt_type(skb) = pkt_type;
414
415 ret = hci_recv_frame(data->hdev, skb);
416 break;
417
418 case HCI_VENDOR_PKT:
419 cancel_delayed_work_sync(&data->open_timeout);
420
421 opcode = *((__u8 *) skb->data);
422 skb_pull(skb, 1);
423
424 if (skb->len > 0) {
425 kfree_skb(skb);
426 return -EINVAL;
427 }
428
429 kfree_skb(skb);
430
431 ret = vhci_create_device(data, opcode);
432 break;
433
434 default:
435 kfree_skb(skb);
436 return -EINVAL;
437 }
438
439 return (ret < 0) ? ret : len;
440 }
441
vhci_put_user(struct vhci_data * data,struct sk_buff * skb,char __user * buf,int count)442 static inline ssize_t vhci_put_user(struct vhci_data *data,
443 struct sk_buff *skb,
444 char __user *buf, int count)
445 {
446 char __user *ptr = buf;
447 int len;
448
449 len = min_t(unsigned int, skb->len, count);
450
451 if (copy_to_user(ptr, skb->data, len))
452 return -EFAULT;
453
454 if (!data->hdev)
455 return len;
456
457 data->hdev->stat.byte_tx += len;
458
459 switch (hci_skb_pkt_type(skb)) {
460 case HCI_COMMAND_PKT:
461 data->hdev->stat.cmd_tx++;
462 break;
463 case HCI_ACLDATA_PKT:
464 data->hdev->stat.acl_tx++;
465 break;
466 case HCI_SCODATA_PKT:
467 data->hdev->stat.sco_tx++;
468 break;
469 }
470
471 return len;
472 }
473
vhci_read(struct file * file,char __user * buf,size_t count,loff_t * pos)474 static ssize_t vhci_read(struct file *file,
475 char __user *buf, size_t count, loff_t *pos)
476 {
477 struct vhci_data *data = file->private_data;
478 struct sk_buff *skb;
479 ssize_t ret = 0;
480
481 while (count) {
482 skb = skb_dequeue(&data->readq);
483 if (skb) {
484 ret = vhci_put_user(data, skb, buf, count);
485 if (ret < 0)
486 skb_queue_head(&data->readq, skb);
487 else
488 kfree_skb(skb);
489 break;
490 }
491
492 if (file->f_flags & O_NONBLOCK) {
493 ret = -EAGAIN;
494 break;
495 }
496
497 ret = wait_event_interruptible(data->read_wait,
498 !skb_queue_empty(&data->readq));
499 if (ret < 0)
500 break;
501 }
502
503 return ret;
504 }
505
vhci_write(struct kiocb * iocb,struct iov_iter * from)506 static ssize_t vhci_write(struct kiocb *iocb, struct iov_iter *from)
507 {
508 struct file *file = iocb->ki_filp;
509 struct vhci_data *data = file->private_data;
510
511 return vhci_get_user(data, from);
512 }
513
vhci_poll(struct file * file,poll_table * wait)514 static __poll_t vhci_poll(struct file *file, poll_table *wait)
515 {
516 struct vhci_data *data = file->private_data;
517
518 poll_wait(file, &data->read_wait, wait);
519
520 if (!skb_queue_empty(&data->readq))
521 return EPOLLIN | EPOLLRDNORM;
522
523 return EPOLLOUT | EPOLLWRNORM;
524 }
525
vhci_open_timeout(struct work_struct * work)526 static void vhci_open_timeout(struct work_struct *work)
527 {
528 struct vhci_data *data = container_of(work, struct vhci_data,
529 open_timeout.work);
530
531 vhci_create_device(data, amp ? HCI_AMP : HCI_PRIMARY);
532 }
533
vhci_open(struct inode * inode,struct file * file)534 static int vhci_open(struct inode *inode, struct file *file)
535 {
536 struct vhci_data *data;
537
538 data = kzalloc(sizeof(struct vhci_data), GFP_KERNEL);
539 if (!data)
540 return -ENOMEM;
541
542 skb_queue_head_init(&data->readq);
543 init_waitqueue_head(&data->read_wait);
544
545 mutex_init(&data->open_mutex);
546 INIT_DELAYED_WORK(&data->open_timeout, vhci_open_timeout);
547 INIT_WORK(&data->suspend_work, vhci_suspend_work);
548
549 file->private_data = data;
550 nonseekable_open(inode, file);
551
552 schedule_delayed_work(&data->open_timeout, msecs_to_jiffies(1000));
553
554 return 0;
555 }
556
vhci_release(struct inode * inode,struct file * file)557 static int vhci_release(struct inode *inode, struct file *file)
558 {
559 struct vhci_data *data = file->private_data;
560 struct hci_dev *hdev;
561
562 cancel_delayed_work_sync(&data->open_timeout);
563 flush_work(&data->suspend_work);
564
565 hdev = data->hdev;
566
567 if (hdev) {
568 hci_unregister_dev(hdev);
569 hci_free_dev(hdev);
570 }
571
572 skb_queue_purge(&data->readq);
573 file->private_data = NULL;
574 kfree(data);
575
576 return 0;
577 }
578
579 static const struct file_operations vhci_fops = {
580 .owner = THIS_MODULE,
581 .read = vhci_read,
582 .write_iter = vhci_write,
583 .poll = vhci_poll,
584 .open = vhci_open,
585 .release = vhci_release,
586 .llseek = no_llseek,
587 };
588
589 static struct miscdevice vhci_miscdev = {
590 .name = "vhci",
591 .fops = &vhci_fops,
592 .minor = VHCI_MINOR,
593 };
594 module_misc_device(vhci_miscdev);
595
596 module_param(amp, bool, 0644);
597 MODULE_PARM_DESC(amp, "Create AMP controller device");
598
599 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
600 MODULE_DESCRIPTION("Bluetooth virtual HCI driver ver " VERSION);
601 MODULE_VERSION(VERSION);
602 MODULE_LICENSE("GPL");
603 MODULE_ALIAS("devname:vhci");
604 MODULE_ALIAS_MISCDEV(VHCI_MINOR);
605
