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
78 mutex_lock(&data->open_mutex);
79 skb_queue_tail(&data->readq, skb);
80 mutex_unlock(&data->open_mutex);
81
82 wake_up_interruptible(&data->read_wait);
83 return 0;
84 }
85
vhci_get_data_path_id(struct hci_dev * hdev,u8 * data_path_id)86 static int vhci_get_data_path_id(struct hci_dev *hdev, u8 *data_path_id)
87 {
88 *data_path_id = 0;
89 return 0;
90 }
91
vhci_get_codec_config_data(struct hci_dev * hdev,__u8 type,struct bt_codec * codec,__u8 * vnd_len,__u8 ** vnd_data)92 static int vhci_get_codec_config_data(struct hci_dev *hdev, __u8 type,
93 struct bt_codec *codec, __u8 *vnd_len,
94 __u8 **vnd_data)
95 {
96 if (type != ESCO_LINK)
97 return -EINVAL;
98
99 *vnd_len = 0;
100 *vnd_data = NULL;
101 return 0;
102 }
103
vhci_wakeup(struct hci_dev * hdev)104 static bool vhci_wakeup(struct hci_dev *hdev)
105 {
106 struct vhci_data *data = hci_get_drvdata(hdev);
107
108 return data->wakeup;
109 }
110
force_suspend_read(struct file * file,char __user * user_buf,size_t count,loff_t * ppos)111 static ssize_t force_suspend_read(struct file *file, char __user *user_buf,
112 size_t count, loff_t *ppos)
113 {
114 struct vhci_data *data = file->private_data;
115 char buf[3];
116
117 buf[0] = data->suspended ? 'Y' : 'N';
118 buf[1] = '\n';
119 buf[2] = '\0';
120 return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
121 }
122
vhci_suspend_work(struct work_struct * work)123 static void vhci_suspend_work(struct work_struct *work)
124 {
125 struct vhci_data *data = container_of(work, struct vhci_data,
126 suspend_work);
127
128 if (data->suspended)
129 hci_suspend_dev(data->hdev);
130 else
131 hci_resume_dev(data->hdev);
132 }
133
force_suspend_write(struct file * file,const char __user * user_buf,size_t count,loff_t * ppos)134 static ssize_t force_suspend_write(struct file *file,
135 const char __user *user_buf,
136 size_t count, loff_t *ppos)
137 {
138 struct vhci_data *data = file->private_data;
139 bool enable;
140 int err;
141
142 err = kstrtobool_from_user(user_buf, count, &enable);
143 if (err)
144 return err;
145
146 if (data->suspended == enable)
147 return -EALREADY;
148
149 data->suspended = enable;
150
151 schedule_work(&data->suspend_work);
152
153 return count;
154 }
155
156 static const struct file_operations force_suspend_fops = {
157 .open = simple_open,
158 .read = force_suspend_read,
159 .write = force_suspend_write,
160 .llseek = default_llseek,
161 };
162
force_wakeup_read(struct file * file,char __user * user_buf,size_t count,loff_t * ppos)163 static ssize_t force_wakeup_read(struct file *file, char __user *user_buf,
164 size_t count, loff_t *ppos)
165 {
166 struct vhci_data *data = file->private_data;
167 char buf[3];
168
169 buf[0] = data->wakeup ? 'Y' : 'N';
170 buf[1] = '\n';
171 buf[2] = '\0';
172 return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
173 }
174
force_wakeup_write(struct file * file,const char __user * user_buf,size_t count,loff_t * ppos)175 static ssize_t force_wakeup_write(struct file *file,
176 const char __user *user_buf, size_t count,
177 loff_t *ppos)
178 {
179 struct vhci_data *data = file->private_data;
180 bool enable;
181 int err;
182
183 err = kstrtobool_from_user(user_buf, count, &enable);
184 if (err)
185 return err;
186
187 if (data->wakeup == enable)
188 return -EALREADY;
189
190 data->wakeup = enable;
191
192 return count;
193 }
194
195 static const struct file_operations force_wakeup_fops = {
196 .open = simple_open,
197 .read = force_wakeup_read,
198 .write = force_wakeup_write,
199 .llseek = default_llseek,
200 };
201
msft_opcode_set(void * data,u64 val)202 static int msft_opcode_set(void *data, u64 val)
203 {
204 struct vhci_data *vhci = data;
205
206 if (val > 0xffff || hci_opcode_ogf(val) != 0x3f)
207 return -EINVAL;
208
209 if (vhci->msft_opcode)
210 return -EALREADY;
211
212 vhci->msft_opcode = val;
213
214 return 0;
215 }
216
msft_opcode_get(void * data,u64 * val)217 static int msft_opcode_get(void *data, u64 *val)
218 {
219 struct vhci_data *vhci = data;
220
221 *val = vhci->msft_opcode;
222
223 return 0;
224 }
225
226 DEFINE_DEBUGFS_ATTRIBUTE(msft_opcode_fops, msft_opcode_get, msft_opcode_set,
227 "%llu\n");
228
aosp_capable_read(struct file * file,char __user * user_buf,size_t count,loff_t * ppos)229 static ssize_t aosp_capable_read(struct file *file, char __user *user_buf,
230 size_t count, loff_t *ppos)
231 {
232 struct vhci_data *vhci = file->private_data;
233 char buf[3];
234
235 buf[0] = vhci->aosp_capable ? 'Y' : 'N';
236 buf[1] = '\n';
237 buf[2] = '\0';
238 return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
239 }
240
aosp_capable_write(struct file * file,const char __user * user_buf,size_t count,loff_t * ppos)241 static ssize_t aosp_capable_write(struct file *file,
242 const char __user *user_buf, size_t count,
243 loff_t *ppos)
244 {
245 struct vhci_data *vhci = file->private_data;
246 bool enable;
247 int err;
248
249 err = kstrtobool_from_user(user_buf, count, &enable);
250 if (err)
251 return err;
252
253 if (!enable)
254 return -EINVAL;
255
256 if (vhci->aosp_capable)
257 return -EALREADY;
258
259 vhci->aosp_capable = enable;
260
261 return count;
262 }
263
264 static const struct file_operations aosp_capable_fops = {
265 .open = simple_open,
266 .read = aosp_capable_read,
267 .write = aosp_capable_write,
268 .llseek = default_llseek,
269 };
270
vhci_setup(struct hci_dev * hdev)271 static int vhci_setup(struct hci_dev *hdev)
272 {
273 struct vhci_data *vhci = hci_get_drvdata(hdev);
274
275 if (vhci->msft_opcode)
276 hci_set_msft_opcode(hdev, vhci->msft_opcode);
277
278 if (vhci->aosp_capable)
279 hci_set_aosp_capable(hdev);
280
281 return 0;
282 }
283
vhci_coredump(struct hci_dev * hdev)284 static void vhci_coredump(struct hci_dev *hdev)
285 {
286 /* No need to do anything */
287 }
288
vhci_coredump_hdr(struct hci_dev * hdev,struct sk_buff * skb)289 static void vhci_coredump_hdr(struct hci_dev *hdev, struct sk_buff *skb)
290 {
291 char buf[80];
292
293 snprintf(buf, sizeof(buf), "Controller Name: vhci_ctrl\n");
294 skb_put_data(skb, buf, strlen(buf));
295
296 snprintf(buf, sizeof(buf), "Firmware Version: vhci_fw\n");
297 skb_put_data(skb, buf, strlen(buf));
298
299 snprintf(buf, sizeof(buf), "Driver: vhci_drv\n");
300 skb_put_data(skb, buf, strlen(buf));
301
302 snprintf(buf, sizeof(buf), "Vendor: vhci\n");
303 skb_put_data(skb, buf, strlen(buf));
304 }
305
306 #define MAX_COREDUMP_LINE_LEN 40
307
308 struct devcoredump_test_data {
309 enum devcoredump_state state;
310 unsigned int timeout;
311 char data[MAX_COREDUMP_LINE_LEN];
312 };
313
force_devcd_timeout(struct hci_dev * hdev,unsigned int timeout)314 static inline void force_devcd_timeout(struct hci_dev *hdev,
315 unsigned int timeout)
316 {
317 #ifdef CONFIG_DEV_COREDUMP
318 hdev->dump.timeout = msecs_to_jiffies(timeout * 1000);
319 #endif
320 }
321
force_devcd_write(struct file * file,const char __user * user_buf,size_t count,loff_t * ppos)322 static ssize_t force_devcd_write(struct file *file, const char __user *user_buf,
323 size_t count, loff_t *ppos)
324 {
325 struct vhci_data *data = file->private_data;
326 struct hci_dev *hdev = data->hdev;
327 struct sk_buff *skb = NULL;
328 struct devcoredump_test_data dump_data;
329 size_t data_size;
330 int ret;
331
332 if (count < offsetof(struct devcoredump_test_data, data) ||
333 count > sizeof(dump_data))
334 return -EINVAL;
335
336 if (copy_from_user(&dump_data, user_buf, count))
337 return -EFAULT;
338
339 data_size = count - offsetof(struct devcoredump_test_data, data);
340 skb = alloc_skb(data_size, GFP_ATOMIC);
341 if (!skb)
342 return -ENOMEM;
343 skb_put_data(skb, &dump_data.data, data_size);
344
345 hci_devcd_register(hdev, vhci_coredump, vhci_coredump_hdr, NULL);
346
347 /* Force the devcoredump timeout */
348 if (dump_data.timeout)
349 force_devcd_timeout(hdev, dump_data.timeout);
350
351 ret = hci_devcd_init(hdev, skb->len);
352 if (ret) {
353 BT_ERR("Failed to generate devcoredump");
354 kfree_skb(skb);
355 return ret;
356 }
357
358 hci_devcd_append(hdev, skb);
359
360 switch (dump_data.state) {
361 case HCI_DEVCOREDUMP_DONE:
362 hci_devcd_complete(hdev);
363 break;
364 case HCI_DEVCOREDUMP_ABORT:
365 hci_devcd_abort(hdev);
366 break;
367 case HCI_DEVCOREDUMP_TIMEOUT:
368 /* Do nothing */
369 break;
370 default:
371 return -EINVAL;
372 }
373
374 return count;
375 }
376
377 static const struct file_operations force_devcoredump_fops = {
378 .open = simple_open,
379 .write = force_devcd_write,
380 };
381
__vhci_create_device(struct vhci_data * data,__u8 opcode)382 static int __vhci_create_device(struct vhci_data *data, __u8 opcode)
383 {
384 struct hci_dev *hdev;
385 struct sk_buff *skb;
386 __u8 dev_type;
387
388 if (data->hdev)
389 return -EBADFD;
390
391 /* bits 0-1 are dev_type (Primary or AMP) */
392 dev_type = opcode & 0x03;
393
394 if (dev_type != HCI_PRIMARY && dev_type != HCI_AMP)
395 return -EINVAL;
396
397 /* bits 2-5 are reserved (must be zero) */
398 if (opcode & 0x3c)
399 return -EINVAL;
400
401 skb = bt_skb_alloc(4, GFP_KERNEL);
402 if (!skb)
403 return -ENOMEM;
404
405 hdev = hci_alloc_dev();
406 if (!hdev) {
407 kfree_skb(skb);
408 return -ENOMEM;
409 }
410
411 data->hdev = hdev;
412
413 hdev->bus = HCI_VIRTUAL;
414 hdev->dev_type = dev_type;
415 hci_set_drvdata(hdev, data);
416
417 hdev->open = vhci_open_dev;
418 hdev->close = vhci_close_dev;
419 hdev->flush = vhci_flush;
420 hdev->send = vhci_send_frame;
421 hdev->get_data_path_id = vhci_get_data_path_id;
422 hdev->get_codec_config_data = vhci_get_codec_config_data;
423 hdev->wakeup = vhci_wakeup;
424 hdev->setup = vhci_setup;
425 set_bit(HCI_QUIRK_NON_PERSISTENT_SETUP, &hdev->quirks);
426
427 /* bit 6 is for external configuration */
428 if (opcode & 0x40)
429 set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);
430
431 /* bit 7 is for raw device */
432 if (opcode & 0x80)
433 set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
434
435 set_bit(HCI_QUIRK_VALID_LE_STATES, &hdev->quirks);
436
437 if (hci_register_dev(hdev) < 0) {
438 BT_ERR("Can't register HCI device");
439 hci_free_dev(hdev);
440 data->hdev = NULL;
441 kfree_skb(skb);
442 return -EBUSY;
443 }
444
445 debugfs_create_file("force_suspend", 0644, hdev->debugfs, data,
446 &force_suspend_fops);
447
448 debugfs_create_file("force_wakeup", 0644, hdev->debugfs, data,
449 &force_wakeup_fops);
450
451 if (IS_ENABLED(CONFIG_BT_MSFTEXT))
452 debugfs_create_file("msft_opcode", 0644, hdev->debugfs, data,
453 &msft_opcode_fops);
454
455 if (IS_ENABLED(CONFIG_BT_AOSPEXT))
456 debugfs_create_file("aosp_capable", 0644, hdev->debugfs, data,
457 &aosp_capable_fops);
458
459 debugfs_create_file("force_devcoredump", 0644, hdev->debugfs, data,
460 &force_devcoredump_fops);
461
462 hci_skb_pkt_type(skb) = HCI_VENDOR_PKT;
463
464 skb_put_u8(skb, 0xff);
465 skb_put_u8(skb, opcode);
466 put_unaligned_le16(hdev->id, skb_put(skb, 2));
467 skb_queue_tail(&data->readq, skb);
468
469 wake_up_interruptible(&data->read_wait);
470 return 0;
471 }
472
vhci_create_device(struct vhci_data * data,__u8 opcode)473 static int vhci_create_device(struct vhci_data *data, __u8 opcode)
474 {
475 int err;
476
477 mutex_lock(&data->open_mutex);
478 err = __vhci_create_device(data, opcode);
479 mutex_unlock(&data->open_mutex);
480
481 return err;
482 }
483
vhci_get_user(struct vhci_data * data,struct iov_iter * from)484 static inline ssize_t vhci_get_user(struct vhci_data *data,
485 struct iov_iter *from)
486 {
487 size_t len = iov_iter_count(from);
488 struct sk_buff *skb;
489 __u8 pkt_type, opcode;
490 int ret;
491
492 if (len < 2 || len > HCI_MAX_FRAME_SIZE)
493 return -EINVAL;
494
495 skb = bt_skb_alloc(len, GFP_KERNEL);
496 if (!skb)
497 return -ENOMEM;
498
499 if (!copy_from_iter_full(skb_put(skb, len), len, from)) {
500 kfree_skb(skb);
501 return -EFAULT;
502 }
503
504 pkt_type = *((__u8 *) skb->data);
505 skb_pull(skb, 1);
506
507 switch (pkt_type) {
508 case HCI_EVENT_PKT:
509 case HCI_ACLDATA_PKT:
510 case HCI_SCODATA_PKT:
511 case HCI_ISODATA_PKT:
512 if (!data->hdev) {
513 kfree_skb(skb);
514 return -ENODEV;
515 }
516
517 hci_skb_pkt_type(skb) = pkt_type;
518
519 ret = hci_recv_frame(data->hdev, skb);
520 break;
521
522 case HCI_VENDOR_PKT:
523 cancel_delayed_work_sync(&data->open_timeout);
524
525 opcode = *((__u8 *) skb->data);
526 skb_pull(skb, 1);
527
528 if (skb->len > 0) {
529 kfree_skb(skb);
530 return -EINVAL;
531 }
532
533 kfree_skb(skb);
534
535 ret = vhci_create_device(data, opcode);
536 break;
537
538 default:
539 kfree_skb(skb);
540 return -EINVAL;
541 }
542
543 return (ret < 0) ? ret : len;
544 }
545
vhci_put_user(struct vhci_data * data,struct sk_buff * skb,char __user * buf,int count)546 static inline ssize_t vhci_put_user(struct vhci_data *data,
547 struct sk_buff *skb,
548 char __user *buf, int count)
549 {
550 char __user *ptr = buf;
551 int len;
552
553 len = min_t(unsigned int, skb->len, count);
554
555 if (copy_to_user(ptr, skb->data, len))
556 return -EFAULT;
557
558 if (!data->hdev)
559 return len;
560
561 data->hdev->stat.byte_tx += len;
562
563 switch (hci_skb_pkt_type(skb)) {
564 case HCI_COMMAND_PKT:
565 data->hdev->stat.cmd_tx++;
566 break;
567 case HCI_ACLDATA_PKT:
568 data->hdev->stat.acl_tx++;
569 break;
570 case HCI_SCODATA_PKT:
571 data->hdev->stat.sco_tx++;
572 break;
573 }
574
575 return len;
576 }
577
vhci_read(struct file * file,char __user * buf,size_t count,loff_t * pos)578 static ssize_t vhci_read(struct file *file,
579 char __user *buf, size_t count, loff_t *pos)
580 {
581 struct vhci_data *data = file->private_data;
582 struct sk_buff *skb;
583 ssize_t ret = 0;
584
585 while (count) {
586 skb = skb_dequeue(&data->readq);
587 if (skb) {
588 ret = vhci_put_user(data, skb, buf, count);
589 if (ret < 0)
590 skb_queue_head(&data->readq, skb);
591 else
592 kfree_skb(skb);
593 break;
594 }
595
596 if (file->f_flags & O_NONBLOCK) {
597 ret = -EAGAIN;
598 break;
599 }
600
601 ret = wait_event_interruptible(data->read_wait,
602 !skb_queue_empty(&data->readq));
603 if (ret < 0)
604 break;
605 }
606
607 return ret;
608 }
609
vhci_write(struct kiocb * iocb,struct iov_iter * from)610 static ssize_t vhci_write(struct kiocb *iocb, struct iov_iter *from)
611 {
612 struct file *file = iocb->ki_filp;
613 struct vhci_data *data = file->private_data;
614
615 return vhci_get_user(data, from);
616 }
617
vhci_poll(struct file * file,poll_table * wait)618 static __poll_t vhci_poll(struct file *file, poll_table *wait)
619 {
620 struct vhci_data *data = file->private_data;
621
622 poll_wait(file, &data->read_wait, wait);
623
624 if (!skb_queue_empty(&data->readq))
625 return EPOLLIN | EPOLLRDNORM;
626
627 return EPOLLOUT | EPOLLWRNORM;
628 }
629
vhci_open_timeout(struct work_struct * work)630 static void vhci_open_timeout(struct work_struct *work)
631 {
632 struct vhci_data *data = container_of(work, struct vhci_data,
633 open_timeout.work);
634
635 vhci_create_device(data, amp ? HCI_AMP : HCI_PRIMARY);
636 }
637
vhci_open(struct inode * inode,struct file * file)638 static int vhci_open(struct inode *inode, struct file *file)
639 {
640 struct vhci_data *data;
641
642 data = kzalloc(sizeof(struct vhci_data), GFP_KERNEL);
643 if (!data)
644 return -ENOMEM;
645
646 skb_queue_head_init(&data->readq);
647 init_waitqueue_head(&data->read_wait);
648
649 mutex_init(&data->open_mutex);
650 INIT_DELAYED_WORK(&data->open_timeout, vhci_open_timeout);
651 INIT_WORK(&data->suspend_work, vhci_suspend_work);
652
653 file->private_data = data;
654 nonseekable_open(inode, file);
655
656 schedule_delayed_work(&data->open_timeout, msecs_to_jiffies(1000));
657
658 return 0;
659 }
660
vhci_release(struct inode * inode,struct file * file)661 static int vhci_release(struct inode *inode, struct file *file)
662 {
663 struct vhci_data *data = file->private_data;
664 struct hci_dev *hdev;
665
666 cancel_delayed_work_sync(&data->open_timeout);
667 flush_work(&data->suspend_work);
668
669 hdev = data->hdev;
670
671 if (hdev) {
672 hci_unregister_dev(hdev);
673 hci_free_dev(hdev);
674 }
675
676 skb_queue_purge(&data->readq);
677 file->private_data = NULL;
678 kfree(data);
679
680 return 0;
681 }
682
683 static const struct file_operations vhci_fops = {
684 .owner = THIS_MODULE,
685 .read = vhci_read,
686 .write_iter = vhci_write,
687 .poll = vhci_poll,
688 .open = vhci_open,
689 .release = vhci_release,
690 .llseek = no_llseek,
691 };
692
693 static struct miscdevice vhci_miscdev = {
694 .name = "vhci",
695 .fops = &vhci_fops,
696 .minor = VHCI_MINOR,
697 };
698 module_misc_device(vhci_miscdev);
699
700 module_param(amp, bool, 0644);
701 MODULE_PARM_DESC(amp, "Create AMP controller device");
702
703 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
704 MODULE_DESCRIPTION("Bluetooth virtual HCI driver ver " VERSION);
705 MODULE_VERSION(VERSION);
706 MODULE_LICENSE("GPL");
707 MODULE_ALIAS("devname:vhci");
708 MODULE_ALIAS_MISCDEV(VHCI_MINOR);
709
