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 <linux/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 if (hci_register_dev(hdev) < 0) {
429 BT_ERR("Can't register HCI device");
430 hci_free_dev(hdev);
431 data->hdev = NULL;
432 kfree_skb(skb);
433 return -EBUSY;
434 }
435
436 debugfs_create_file("force_suspend", 0644, hdev->debugfs, data,
437 &force_suspend_fops);
438
439 debugfs_create_file("force_wakeup", 0644, hdev->debugfs, data,
440 &force_wakeup_fops);
441
442 if (IS_ENABLED(CONFIG_BT_MSFTEXT))
443 debugfs_create_file("msft_opcode", 0644, hdev->debugfs, data,
444 &msft_opcode_fops);
445
446 if (IS_ENABLED(CONFIG_BT_AOSPEXT))
447 debugfs_create_file("aosp_capable", 0644, hdev->debugfs, data,
448 &aosp_capable_fops);
449
450 debugfs_create_file("force_devcoredump", 0644, hdev->debugfs, data,
451 &force_devcoredump_fops);
452
453 hci_skb_pkt_type(skb) = HCI_VENDOR_PKT;
454
455 skb_put_u8(skb, 0xff);
456 skb_put_u8(skb, opcode);
457 put_unaligned_le16(hdev->id, skb_put(skb, 2));
458 skb_queue_head(&data->readq, skb);
459 atomic_inc(&data->initialized);
460
461 wake_up_interruptible(&data->read_wait);
462 return 0;
463 }
464
vhci_create_device(struct vhci_data * data,__u8 opcode)465 static int vhci_create_device(struct vhci_data *data, __u8 opcode)
466 {
467 int err;
468
469 mutex_lock(&data->open_mutex);
470 err = __vhci_create_device(data, opcode);
471 mutex_unlock(&data->open_mutex);
472
473 return err;
474 }
475
vhci_get_user(struct vhci_data * data,struct iov_iter * from)476 static inline ssize_t vhci_get_user(struct vhci_data *data,
477 struct iov_iter *from)
478 {
479 size_t len = iov_iter_count(from);
480 struct sk_buff *skb;
481 __u8 pkt_type, opcode;
482 int ret;
483
484 if (len < 2 || len > HCI_MAX_FRAME_SIZE)
485 return -EINVAL;
486
487 skb = bt_skb_alloc(len, GFP_KERNEL);
488 if (!skb)
489 return -ENOMEM;
490
491 if (!copy_from_iter_full(skb_put(skb, len), len, from)) {
492 kfree_skb(skb);
493 return -EFAULT;
494 }
495
496 pkt_type = *((__u8 *) skb->data);
497 skb_pull(skb, 1);
498
499 switch (pkt_type) {
500 case HCI_EVENT_PKT:
501 case HCI_ACLDATA_PKT:
502 case HCI_SCODATA_PKT:
503 case HCI_ISODATA_PKT:
504 if (!data->hdev) {
505 kfree_skb(skb);
506 return -ENODEV;
507 }
508
509 hci_skb_pkt_type(skb) = pkt_type;
510
511 ret = hci_recv_frame(data->hdev, skb);
512 break;
513
514 case HCI_VENDOR_PKT:
515 cancel_delayed_work_sync(&data->open_timeout);
516
517 opcode = *((__u8 *) skb->data);
518 skb_pull(skb, 1);
519
520 if (skb->len > 0) {
521 kfree_skb(skb);
522 return -EINVAL;
523 }
524
525 kfree_skb(skb);
526
527 ret = vhci_create_device(data, opcode);
528 break;
529
530 default:
531 kfree_skb(skb);
532 return -EINVAL;
533 }
534
535 return (ret < 0) ? ret : len;
536 }
537
vhci_put_user(struct vhci_data * data,struct sk_buff * skb,char __user * buf,int count)538 static inline ssize_t vhci_put_user(struct vhci_data *data,
539 struct sk_buff *skb,
540 char __user *buf, int count)
541 {
542 char __user *ptr = buf;
543 int len;
544
545 len = min_t(unsigned int, skb->len, count);
546
547 if (copy_to_user(ptr, skb->data, len))
548 return -EFAULT;
549
550 if (!data->hdev)
551 return len;
552
553 data->hdev->stat.byte_tx += len;
554
555 switch (hci_skb_pkt_type(skb)) {
556 case HCI_COMMAND_PKT:
557 data->hdev->stat.cmd_tx++;
558 break;
559 case HCI_ACLDATA_PKT:
560 data->hdev->stat.acl_tx++;
561 break;
562 case HCI_SCODATA_PKT:
563 data->hdev->stat.sco_tx++;
564 break;
565 }
566
567 return len;
568 }
569
vhci_read(struct file * file,char __user * buf,size_t count,loff_t * pos)570 static ssize_t vhci_read(struct file *file,
571 char __user *buf, size_t count, loff_t *pos)
572 {
573 struct vhci_data *data = file->private_data;
574 struct sk_buff *skb;
575 ssize_t ret = 0;
576
577 while (count) {
578 skb = skb_dequeue(&data->readq);
579 if (skb) {
580 ret = vhci_put_user(data, skb, buf, count);
581 if (ret < 0)
582 skb_queue_head(&data->readq, skb);
583 else
584 kfree_skb(skb);
585 break;
586 }
587
588 if (file->f_flags & O_NONBLOCK) {
589 ret = -EAGAIN;
590 break;
591 }
592
593 ret = wait_event_interruptible(data->read_wait,
594 !skb_queue_empty(&data->readq));
595 if (ret < 0)
596 break;
597 }
598
599 return ret;
600 }
601
vhci_write(struct kiocb * iocb,struct iov_iter * from)602 static ssize_t vhci_write(struct kiocb *iocb, struct iov_iter *from)
603 {
604 struct file *file = iocb->ki_filp;
605 struct vhci_data *data = file->private_data;
606
607 return vhci_get_user(data, from);
608 }
609
vhci_poll(struct file * file,poll_table * wait)610 static __poll_t vhci_poll(struct file *file, poll_table *wait)
611 {
612 struct vhci_data *data = file->private_data;
613
614 poll_wait(file, &data->read_wait, wait);
615
616 if (!skb_queue_empty(&data->readq))
617 return EPOLLIN | EPOLLRDNORM;
618
619 return EPOLLOUT | EPOLLWRNORM;
620 }
621
vhci_open_timeout(struct work_struct * work)622 static void vhci_open_timeout(struct work_struct *work)
623 {
624 struct vhci_data *data = container_of(work, struct vhci_data,
625 open_timeout.work);
626
627 vhci_create_device(data, 0x00);
628 }
629
vhci_open(struct inode * inode,struct file * file)630 static int vhci_open(struct inode *inode, struct file *file)
631 {
632 struct vhci_data *data;
633
634 data = kzalloc(sizeof(*data), GFP_KERNEL);
635 if (!data)
636 return -ENOMEM;
637
638 skb_queue_head_init(&data->readq);
639 init_waitqueue_head(&data->read_wait);
640
641 mutex_init(&data->open_mutex);
642 INIT_DELAYED_WORK(&data->open_timeout, vhci_open_timeout);
643 INIT_WORK(&data->suspend_work, vhci_suspend_work);
644
645 file->private_data = data;
646 nonseekable_open(inode, file);
647
648 schedule_delayed_work(&data->open_timeout, msecs_to_jiffies(1000));
649
650 return 0;
651 }
652
vhci_release(struct inode * inode,struct file * file)653 static int vhci_release(struct inode *inode, struct file *file)
654 {
655 struct vhci_data *data = file->private_data;
656 struct hci_dev *hdev;
657
658 cancel_delayed_work_sync(&data->open_timeout);
659 flush_work(&data->suspend_work);
660
661 hdev = data->hdev;
662
663 if (hdev) {
664 hci_unregister_dev(hdev);
665 hci_free_dev(hdev);
666 }
667
668 skb_queue_purge(&data->readq);
669 file->private_data = NULL;
670 kfree(data);
671
672 return 0;
673 }
674
675 static const struct file_operations vhci_fops = {
676 .owner = THIS_MODULE,
677 .read = vhci_read,
678 .write_iter = vhci_write,
679 .poll = vhci_poll,
680 .open = vhci_open,
681 .release = vhci_release,
682 };
683
684 static struct miscdevice vhci_miscdev = {
685 .name = "vhci",
686 .fops = &vhci_fops,
687 .minor = VHCI_MINOR,
688 };
689 module_misc_device(vhci_miscdev);
690
691 module_param(amp, bool, 0644);
692 MODULE_PARM_DESC(amp, "Create AMP controller device");
693
694 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
695 MODULE_DESCRIPTION("Bluetooth virtual HCI driver ver " VERSION);
696 MODULE_VERSION(VERSION);
697 MODULE_LICENSE("GPL");
698 MODULE_ALIAS("devname:vhci");
699 MODULE_ALIAS_MISCDEV(VHCI_MINOR);
700