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/atomic.h>
15 #include <linux/kernel.h>
16 #include <linux/init.h>
17 #include <linux/slab.h>
18 #include <linux/types.h>
19 #include <linux/errno.h>
20 #include <linux/sched.h>
21 #include <linux/poll.h>
22
23 #include <linux/skbuff.h>
24 #include <linux/miscdevice.h>
25 #include <linux/debugfs.h>
26
27 #include <net/bluetooth/bluetooth.h>
28 #include <net/bluetooth/hci_core.h>
29
30 #define VERSION "1.5"
31
32 static bool amp;
33
34 struct vhci_data {
35 struct hci_dev *hdev;
36
37 wait_queue_head_t read_wait;
38 struct sk_buff_head readq;
39
40 struct mutex open_mutex;
41 struct delayed_work open_timeout;
42 struct work_struct suspend_work;
43
44 bool suspended;
45 bool wakeup;
46 __u16 msft_opcode;
47 bool aosp_capable;
48 atomic_t initialized;
49 };
50
vhci_open_dev(struct hci_dev * hdev)51 static int vhci_open_dev(struct hci_dev *hdev)
52 {
53 return 0;
54 }
55
vhci_close_dev(struct hci_dev * hdev)56 static int vhci_close_dev(struct hci_dev *hdev)
57 {
58 struct vhci_data *data = hci_get_drvdata(hdev);
59
60 skb_queue_purge(&data->readq);
61
62 return 0;
63 }
64
vhci_flush(struct hci_dev * hdev)65 static int vhci_flush(struct hci_dev *hdev)
66 {
67 struct vhci_data *data = hci_get_drvdata(hdev);
68
69 skb_queue_purge(&data->readq);
70
71 return 0;
72 }
73
vhci_send_frame(struct hci_dev * hdev,struct sk_buff * skb)74 static int vhci_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
75 {
76 struct vhci_data *data = hci_get_drvdata(hdev);
77
78 memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);
79
80 skb_queue_tail(&data->readq, skb);
81
82 if (atomic_read(&data->initialized))
83 wake_up_interruptible(&data->read_wait);
84 return 0;
85 }
86
vhci_get_data_path_id(struct hci_dev * hdev,u8 * data_path_id)87 static int vhci_get_data_path_id(struct hci_dev *hdev, u8 *data_path_id)
88 {
89 *data_path_id = 0;
90 return 0;
91 }
92
vhci_get_codec_config_data(struct hci_dev * hdev,__u8 type,struct bt_codec * codec,__u8 * vnd_len,__u8 ** vnd_data)93 static int vhci_get_codec_config_data(struct hci_dev *hdev, __u8 type,
94 struct bt_codec *codec, __u8 *vnd_len,
95 __u8 **vnd_data)
96 {
97 if (type != ESCO_LINK)
98 return -EINVAL;
99
100 *vnd_len = 0;
101 *vnd_data = NULL;
102 return 0;
103 }
104
vhci_wakeup(struct hci_dev * hdev)105 static bool vhci_wakeup(struct hci_dev *hdev)
106 {
107 struct vhci_data *data = hci_get_drvdata(hdev);
108
109 return data->wakeup;
110 }
111
force_suspend_read(struct file * file,char __user * user_buf,size_t count,loff_t * ppos)112 static ssize_t force_suspend_read(struct file *file, char __user *user_buf,
113 size_t count, loff_t *ppos)
114 {
115 struct vhci_data *data = file->private_data;
116 char buf[3];
117
118 buf[0] = data->suspended ? 'Y' : 'N';
119 buf[1] = '\n';
120 buf[2] = '\0';
121 return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
122 }
123
vhci_suspend_work(struct work_struct * work)124 static void vhci_suspend_work(struct work_struct *work)
125 {
126 struct vhci_data *data = container_of(work, struct vhci_data,
127 suspend_work);
128
129 if (data->suspended)
130 hci_suspend_dev(data->hdev);
131 else
132 hci_resume_dev(data->hdev);
133 }
134
force_suspend_write(struct file * file,const char __user * user_buf,size_t count,loff_t * ppos)135 static ssize_t force_suspend_write(struct file *file,
136 const char __user *user_buf,
137 size_t count, loff_t *ppos)
138 {
139 struct vhci_data *data = file->private_data;
140 bool enable;
141 int err;
142
143 err = kstrtobool_from_user(user_buf, count, &enable);
144 if (err)
145 return err;
146
147 if (data->suspended == enable)
148 return -EALREADY;
149
150 data->suspended = enable;
151
152 schedule_work(&data->suspend_work);
153
154 return count;
155 }
156
157 static const struct file_operations force_suspend_fops = {
158 .open = simple_open,
159 .read = force_suspend_read,
160 .write = force_suspend_write,
161 .llseek = default_llseek,
162 };
163
force_wakeup_read(struct file * file,char __user * user_buf,size_t count,loff_t * ppos)164 static ssize_t force_wakeup_read(struct file *file, char __user *user_buf,
165 size_t count, loff_t *ppos)
166 {
167 struct vhci_data *data = file->private_data;
168 char buf[3];
169
170 buf[0] = data->wakeup ? 'Y' : 'N';
171 buf[1] = '\n';
172 buf[2] = '\0';
173 return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
174 }
175
force_wakeup_write(struct file * file,const char __user * user_buf,size_t count,loff_t * ppos)176 static ssize_t force_wakeup_write(struct file *file,
177 const char __user *user_buf, size_t count,
178 loff_t *ppos)
179 {
180 struct vhci_data *data = file->private_data;
181 bool enable;
182 int err;
183
184 err = kstrtobool_from_user(user_buf, count, &enable);
185 if (err)
186 return err;
187
188 if (data->wakeup == enable)
189 return -EALREADY;
190
191 data->wakeup = enable;
192
193 return count;
194 }
195
196 static const struct file_operations force_wakeup_fops = {
197 .open = simple_open,
198 .read = force_wakeup_read,
199 .write = force_wakeup_write,
200 .llseek = default_llseek,
201 };
202
msft_opcode_set(void * data,u64 val)203 static int msft_opcode_set(void *data, u64 val)
204 {
205 struct vhci_data *vhci = data;
206
207 if (val > 0xffff || hci_opcode_ogf(val) != 0x3f)
208 return -EINVAL;
209
210 if (vhci->msft_opcode)
211 return -EALREADY;
212
213 vhci->msft_opcode = val;
214
215 return 0;
216 }
217
msft_opcode_get(void * data,u64 * val)218 static int msft_opcode_get(void *data, u64 *val)
219 {
220 struct vhci_data *vhci = data;
221
222 *val = vhci->msft_opcode;
223
224 return 0;
225 }
226
227 DEFINE_DEBUGFS_ATTRIBUTE(msft_opcode_fops, msft_opcode_get, msft_opcode_set,
228 "%llu\n");
229
aosp_capable_read(struct file * file,char __user * user_buf,size_t count,loff_t * ppos)230 static ssize_t aosp_capable_read(struct file *file, char __user *user_buf,
231 size_t count, loff_t *ppos)
232 {
233 struct vhci_data *vhci = file->private_data;
234 char buf[3];
235
236 buf[0] = vhci->aosp_capable ? 'Y' : 'N';
237 buf[1] = '\n';
238 buf[2] = '\0';
239 return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
240 }
241
aosp_capable_write(struct file * file,const char __user * user_buf,size_t count,loff_t * ppos)242 static ssize_t aosp_capable_write(struct file *file,
243 const char __user *user_buf, size_t count,
244 loff_t *ppos)
245 {
246 struct vhci_data *vhci = file->private_data;
247 bool enable;
248 int err;
249
250 err = kstrtobool_from_user(user_buf, count, &enable);
251 if (err)
252 return err;
253
254 if (!enable)
255 return -EINVAL;
256
257 if (vhci->aosp_capable)
258 return -EALREADY;
259
260 vhci->aosp_capable = enable;
261
262 return count;
263 }
264
265 static const struct file_operations aosp_capable_fops = {
266 .open = simple_open,
267 .read = aosp_capable_read,
268 .write = aosp_capable_write,
269 .llseek = default_llseek,
270 };
271
vhci_setup(struct hci_dev * hdev)272 static int vhci_setup(struct hci_dev *hdev)
273 {
274 struct vhci_data *vhci = hci_get_drvdata(hdev);
275
276 if (vhci->msft_opcode)
277 hci_set_msft_opcode(hdev, vhci->msft_opcode);
278
279 if (vhci->aosp_capable)
280 hci_set_aosp_capable(hdev);
281
282 return 0;
283 }
284
vhci_coredump(struct hci_dev * hdev)285 static void vhci_coredump(struct hci_dev *hdev)
286 {
287 /* No need to do anything */
288 }
289
vhci_coredump_hdr(struct hci_dev * hdev,struct sk_buff * skb)290 static void vhci_coredump_hdr(struct hci_dev *hdev, struct sk_buff *skb)
291 {
292 char buf[80];
293
294 snprintf(buf, sizeof(buf), "Controller Name: vhci_ctrl\n");
295 skb_put_data(skb, buf, strlen(buf));
296
297 snprintf(buf, sizeof(buf), "Firmware Version: vhci_fw\n");
298 skb_put_data(skb, buf, strlen(buf));
299
300 snprintf(buf, sizeof(buf), "Driver: vhci_drv\n");
301 skb_put_data(skb, buf, strlen(buf));
302
303 snprintf(buf, sizeof(buf), "Vendor: vhci\n");
304 skb_put_data(skb, buf, strlen(buf));
305 }
306
307 #define MAX_COREDUMP_LINE_LEN 40
308
309 struct devcoredump_test_data {
310 enum devcoredump_state state;
311 unsigned int timeout;
312 char data[MAX_COREDUMP_LINE_LEN];
313 };
314
force_devcd_timeout(struct hci_dev * hdev,unsigned int timeout)315 static inline void force_devcd_timeout(struct hci_dev *hdev,
316 unsigned int timeout)
317 {
318 #ifdef CONFIG_DEV_COREDUMP
319 hdev->dump.timeout = msecs_to_jiffies(timeout * 1000);
320 #endif
321 }
322
force_devcd_write(struct file * file,const char __user * user_buf,size_t count,loff_t * ppos)323 static ssize_t force_devcd_write(struct file *file, const char __user *user_buf,
324 size_t count, loff_t *ppos)
325 {
326 struct vhci_data *data = file->private_data;
327 struct hci_dev *hdev = data->hdev;
328 struct sk_buff *skb = NULL;
329 struct devcoredump_test_data dump_data;
330 size_t data_size;
331 int ret;
332
333 if (count < offsetof(struct devcoredump_test_data, data) ||
334 count > sizeof(dump_data))
335 return -EINVAL;
336
337 if (copy_from_user(&dump_data, user_buf, count))
338 return -EFAULT;
339
340 data_size = count - offsetof(struct devcoredump_test_data, data);
341 skb = alloc_skb(data_size, GFP_ATOMIC);
342 if (!skb)
343 return -ENOMEM;
344 skb_put_data(skb, &dump_data.data, data_size);
345
346 hci_devcd_register(hdev, vhci_coredump, vhci_coredump_hdr, NULL);
347
348 /* Force the devcoredump timeout */
349 if (dump_data.timeout)
350 force_devcd_timeout(hdev, dump_data.timeout);
351
352 ret = hci_devcd_init(hdev, skb->len);
353 if (ret) {
354 BT_ERR("Failed to generate devcoredump");
355 kfree_skb(skb);
356 return ret;
357 }
358
359 hci_devcd_append(hdev, skb);
360
361 switch (dump_data.state) {
362 case HCI_DEVCOREDUMP_DONE:
363 hci_devcd_complete(hdev);
364 break;
365 case HCI_DEVCOREDUMP_ABORT:
366 hci_devcd_abort(hdev);
367 break;
368 case HCI_DEVCOREDUMP_TIMEOUT:
369 /* Do nothing */
370 break;
371 default:
372 return -EINVAL;
373 }
374
375 return count;
376 }
377
378 static const struct file_operations force_devcoredump_fops = {
379 .open = simple_open,
380 .write = force_devcd_write,
381 };
382
__vhci_create_device(struct vhci_data * data,__u8 opcode)383 static int __vhci_create_device(struct vhci_data *data, __u8 opcode)
384 {
385 struct hci_dev *hdev;
386 struct sk_buff *skb;
387
388 if (data->hdev)
389 return -EBADFD;
390
391 /* bits 2-5 are reserved (must be zero) */
392 if (opcode & 0x3c)
393 return -EINVAL;
394
395 skb = bt_skb_alloc(4, GFP_KERNEL);
396 if (!skb)
397 return -ENOMEM;
398
399 hdev = hci_alloc_dev();
400 if (!hdev) {
401 kfree_skb(skb);
402 return -ENOMEM;
403 }
404
405 data->hdev = hdev;
406
407 hdev->bus = HCI_VIRTUAL;
408 hci_set_drvdata(hdev, data);
409
410 hdev->open = vhci_open_dev;
411 hdev->close = vhci_close_dev;
412 hdev->flush = vhci_flush;
413 hdev->send = vhci_send_frame;
414 hdev->get_data_path_id = vhci_get_data_path_id;
415 hdev->get_codec_config_data = vhci_get_codec_config_data;
416 hdev->wakeup = vhci_wakeup;
417 hdev->setup = vhci_setup;
418 set_bit(HCI_QUIRK_NON_PERSISTENT_SETUP, &hdev->quirks);
419
420 /* bit 6 is for external configuration */
421 if (opcode & 0x40)
422 set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);
423
424 /* bit 7 is for raw device */
425 if (opcode & 0x80)
426 set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
427
428 set_bit(HCI_QUIRK_VALID_LE_STATES, &hdev->quirks);
429
430 if (hci_register_dev(hdev) < 0) {
431 BT_ERR("Can't register HCI device");
432 hci_free_dev(hdev);
433 data->hdev = NULL;
434 kfree_skb(skb);
435 return -EBUSY;
436 }
437
438 debugfs_create_file("force_suspend", 0644, hdev->debugfs, data,
439 &force_suspend_fops);
440
441 debugfs_create_file("force_wakeup", 0644, hdev->debugfs, data,
442 &force_wakeup_fops);
443
444 if (IS_ENABLED(CONFIG_BT_MSFTEXT))
445 debugfs_create_file("msft_opcode", 0644, hdev->debugfs, data,
446 &msft_opcode_fops);
447
448 if (IS_ENABLED(CONFIG_BT_AOSPEXT))
449 debugfs_create_file("aosp_capable", 0644, hdev->debugfs, data,
450 &aosp_capable_fops);
451
452 debugfs_create_file("force_devcoredump", 0644, hdev->debugfs, data,
453 &force_devcoredump_fops);
454
455 hci_skb_pkt_type(skb) = HCI_VENDOR_PKT;
456
457 skb_put_u8(skb, 0xff);
458 skb_put_u8(skb, opcode);
459 put_unaligned_le16(hdev->id, skb_put(skb, 2));
460 skb_queue_head(&data->readq, skb);
461 atomic_inc(&data->initialized);
462
463 wake_up_interruptible(&data->read_wait);
464 return 0;
465 }
466
vhci_create_device(struct vhci_data * data,__u8 opcode)467 static int vhci_create_device(struct vhci_data *data, __u8 opcode)
468 {
469 int err;
470
471 mutex_lock(&data->open_mutex);
472 err = __vhci_create_device(data, opcode);
473 mutex_unlock(&data->open_mutex);
474
475 return err;
476 }
477
vhci_get_user(struct vhci_data * data,struct iov_iter * from)478 static inline ssize_t vhci_get_user(struct vhci_data *data,
479 struct iov_iter *from)
480 {
481 size_t len = iov_iter_count(from);
482 struct sk_buff *skb;
483 __u8 pkt_type, opcode;
484 int ret;
485
486 if (len < 2 || len > HCI_MAX_FRAME_SIZE)
487 return -EINVAL;
488
489 skb = bt_skb_alloc(len, GFP_KERNEL);
490 if (!skb)
491 return -ENOMEM;
492
493 if (!copy_from_iter_full(skb_put(skb, len), len, from)) {
494 kfree_skb(skb);
495 return -EFAULT;
496 }
497
498 pkt_type = *((__u8 *) skb->data);
499 skb_pull(skb, 1);
500
501 switch (pkt_type) {
502 case HCI_EVENT_PKT:
503 case HCI_ACLDATA_PKT:
504 case HCI_SCODATA_PKT:
505 case HCI_ISODATA_PKT:
506 if (!data->hdev) {
507 kfree_skb(skb);
508 return -ENODEV;
509 }
510
511 hci_skb_pkt_type(skb) = pkt_type;
512
513 ret = hci_recv_frame(data->hdev, skb);
514 break;
515
516 case HCI_VENDOR_PKT:
517 cancel_delayed_work_sync(&data->open_timeout);
518
519 opcode = *((__u8 *) skb->data);
520 skb_pull(skb, 1);
521
522 if (skb->len > 0) {
523 kfree_skb(skb);
524 return -EINVAL;
525 }
526
527 kfree_skb(skb);
528
529 ret = vhci_create_device(data, opcode);
530 break;
531
532 default:
533 kfree_skb(skb);
534 return -EINVAL;
535 }
536
537 return (ret < 0) ? ret : len;
538 }
539
vhci_put_user(struct vhci_data * data,struct sk_buff * skb,char __user * buf,int count)540 static inline ssize_t vhci_put_user(struct vhci_data *data,
541 struct sk_buff *skb,
542 char __user *buf, int count)
543 {
544 char __user *ptr = buf;
545 int len;
546
547 len = min_t(unsigned int, skb->len, count);
548
549 if (copy_to_user(ptr, skb->data, len))
550 return -EFAULT;
551
552 if (!data->hdev)
553 return len;
554
555 data->hdev->stat.byte_tx += len;
556
557 switch (hci_skb_pkt_type(skb)) {
558 case HCI_COMMAND_PKT:
559 data->hdev->stat.cmd_tx++;
560 break;
561 case HCI_ACLDATA_PKT:
562 data->hdev->stat.acl_tx++;
563 break;
564 case HCI_SCODATA_PKT:
565 data->hdev->stat.sco_tx++;
566 break;
567 }
568
569 return len;
570 }
571
vhci_read(struct file * file,char __user * buf,size_t count,loff_t * pos)572 static ssize_t vhci_read(struct file *file,
573 char __user *buf, size_t count, loff_t *pos)
574 {
575 struct vhci_data *data = file->private_data;
576 struct sk_buff *skb;
577 ssize_t ret = 0;
578
579 while (count) {
580 skb = skb_dequeue(&data->readq);
581 if (skb) {
582 ret = vhci_put_user(data, skb, buf, count);
583 if (ret < 0)
584 skb_queue_head(&data->readq, skb);
585 else
586 kfree_skb(skb);
587 break;
588 }
589
590 if (file->f_flags & O_NONBLOCK) {
591 ret = -EAGAIN;
592 break;
593 }
594
595 ret = wait_event_interruptible(data->read_wait,
596 !skb_queue_empty(&data->readq));
597 if (ret < 0)
598 break;
599 }
600
601 return ret;
602 }
603
vhci_write(struct kiocb * iocb,struct iov_iter * from)604 static ssize_t vhci_write(struct kiocb *iocb, struct iov_iter *from)
605 {
606 struct file *file = iocb->ki_filp;
607 struct vhci_data *data = file->private_data;
608
609 return vhci_get_user(data, from);
610 }
611
vhci_poll(struct file * file,poll_table * wait)612 static __poll_t vhci_poll(struct file *file, poll_table *wait)
613 {
614 struct vhci_data *data = file->private_data;
615
616 poll_wait(file, &data->read_wait, wait);
617
618 if (!skb_queue_empty(&data->readq))
619 return EPOLLIN | EPOLLRDNORM;
620
621 return EPOLLOUT | EPOLLWRNORM;
622 }
623
vhci_open_timeout(struct work_struct * work)624 static void vhci_open_timeout(struct work_struct *work)
625 {
626 struct vhci_data *data = container_of(work, struct vhci_data,
627 open_timeout.work);
628
629 vhci_create_device(data, 0x00);
630 }
631
vhci_open(struct inode * inode,struct file * file)632 static int vhci_open(struct inode *inode, struct file *file)
633 {
634 struct vhci_data *data;
635
636 data = kzalloc(sizeof(struct vhci_data), GFP_KERNEL);
637 if (!data)
638 return -ENOMEM;
639
640 skb_queue_head_init(&data->readq);
641 init_waitqueue_head(&data->read_wait);
642
643 mutex_init(&data->open_mutex);
644 INIT_DELAYED_WORK(&data->open_timeout, vhci_open_timeout);
645 INIT_WORK(&data->suspend_work, vhci_suspend_work);
646
647 file->private_data = data;
648 nonseekable_open(inode, file);
649
650 schedule_delayed_work(&data->open_timeout, msecs_to_jiffies(1000));
651
652 return 0;
653 }
654
vhci_release(struct inode * inode,struct file * file)655 static int vhci_release(struct inode *inode, struct file *file)
656 {
657 struct vhci_data *data = file->private_data;
658 struct hci_dev *hdev;
659
660 cancel_delayed_work_sync(&data->open_timeout);
661 flush_work(&data->suspend_work);
662
663 hdev = data->hdev;
664
665 if (hdev) {
666 hci_unregister_dev(hdev);
667 hci_free_dev(hdev);
668 }
669
670 skb_queue_purge(&data->readq);
671 file->private_data = NULL;
672 kfree(data);
673
674 return 0;
675 }
676
677 static const struct file_operations vhci_fops = {
678 .owner = THIS_MODULE,
679 .read = vhci_read,
680 .write_iter = vhci_write,
681 .poll = vhci_poll,
682 .open = vhci_open,
683 .release = vhci_release,
684 .llseek = no_llseek,
685 };
686
687 static struct miscdevice vhci_miscdev = {
688 .name = "vhci",
689 .fops = &vhci_fops,
690 .minor = VHCI_MINOR,
691 };
692 module_misc_device(vhci_miscdev);
693
694 module_param(amp, bool, 0644);
695 MODULE_PARM_DESC(amp, "Create AMP controller device");
696
697 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
698 MODULE_DESCRIPTION("Bluetooth virtual HCI driver ver " VERSION);
699 MODULE_VERSION(VERSION);
700 MODULE_LICENSE("GPL");
701 MODULE_ALIAS("devname:vhci");
702 MODULE_ALIAS_MISCDEV(VHCI_MINOR);
703