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
32static bool amp;
33
34struct 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
51static int vhci_open_dev(struct hci_dev *hdev)
52{
53 return 0;
54}
55
56static int vhci_close_dev(struct hci_dev *hdev)
57{
58 struct vhci_data *data = hci_get_drvdata(hdev);
59
60 skb_queue_purge(list: &data->readq);
61
62 return 0;
63}
64
65static int vhci_flush(struct hci_dev *hdev)
66{
67 struct vhci_data *data = hci_get_drvdata(hdev);
68
69 skb_queue_purge(list: &data->readq);
70
71 return 0;
72}
73
74static 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(list: &data->readq, newsk: skb);
81
82 if (atomic_read(v: &data->initialized))
83 wake_up_interruptible(&data->read_wait);
84 return 0;
85}
86
87static 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
93static 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
105static bool vhci_wakeup(struct hci_dev *hdev)
106{
107 struct vhci_data *data = hci_get_drvdata(hdev);
108
109 return data->wakeup;
110}
111
112static 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(to: user_buf, count, ppos, from: buf, available: 2);
122}
123
124static 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(hdev: data->hdev);
131 else
132 hci_resume_dev(hdev: data->hdev);
133}
134
135static 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(s: user_buf, count, res: &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(work: &data->suspend_work);
153
154 return count;
155}
156
157static 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
164static 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(to: user_buf, count, ppos, from: buf, available: 2);
174}
175
176static 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(s: user_buf, count, res: &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
196static 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
203static 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
218static 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
227DEFINE_DEBUGFS_ATTRIBUTE(msft_opcode_fops, msft_opcode_get, msft_opcode_set,
228 "%llu\n");
229
230static 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(to: user_buf, count, ppos, from: buf, available: 2);
240}
241
242static 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(s: user_buf, count, res: &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
265static 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
272static 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, opcode: vhci->msft_opcode);
278
279 if (vhci->aosp_capable)
280 hci_set_aosp_capable(hdev);
281
282 return 0;
283}
284
285static void vhci_coredump(struct hci_dev *hdev)
286{
287 /* No need to do anything */
288}
289
290static void vhci_coredump_hdr(struct hci_dev *hdev, struct sk_buff *skb)
291{
292 const char *buf;
293
294 buf = "Controller Name: vhci_ctrl\n";
295 skb_put_data(skb, data: buf, strlen(buf));
296
297 buf = "Firmware Version: vhci_fw\n";
298 skb_put_data(skb, data: buf, strlen(buf));
299
300 buf = "Driver: vhci_drv\n";
301 skb_put_data(skb, data: buf, strlen(buf));
302
303 buf = "Vendor: vhci\n";
304 skb_put_data(skb, data: buf, strlen(buf));
305}
306
307#define MAX_COREDUMP_LINE_LEN 40
308
309struct devcoredump_test_data {
310 enum devcoredump_state state;
311 unsigned int timeout;
312 char data[MAX_COREDUMP_LINE_LEN];
313};
314
315static inline void force_devcd_timeout(struct hci_dev *hdev,
316 unsigned int timeout)
317{
318#ifdef CONFIG_DEV_COREDUMP
319 hdev->dump.timeout = secs_to_jiffies(timeout);
320#endif
321}
322
323static 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(to: &dump_data, from: user_buf, n: count))
338 return -EFAULT;
339
340 data_size = count - offsetof(struct devcoredump_test_data, data);
341 skb = alloc_skb(size: data_size, GFP_ATOMIC);
342 if (!skb)
343 return -ENOMEM;
344 skb_put_data(skb, data: &dump_data.data, len: data_size);
345
346 hci_devcd_register(hdev, coredump: vhci_coredump, dmp_hdr: vhci_coredump_hdr, NULL);
347
348 /* Force the devcoredump timeout */
349 if (dump_data.timeout)
350 force_devcd_timeout(hdev, timeout: dump_data.timeout);
351
352 ret = hci_devcd_init(hdev, dump_size: 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
378static const struct file_operations force_devcoredump_fops = {
379 .open = simple_open,
380 .write = force_devcd_write,
381};
382
383static void vhci_debugfs_init(struct vhci_data *data)
384{
385 struct hci_dev *hdev = data->hdev;
386
387 debugfs_create_file("force_suspend", 0644, hdev->debugfs, data,
388 &force_suspend_fops);
389
390 debugfs_create_file("force_wakeup", 0644, hdev->debugfs, data,
391 &force_wakeup_fops);
392
393 if (IS_ENABLED(CONFIG_BT_MSFTEXT))
394 debugfs_create_file("msft_opcode", 0644, hdev->debugfs, data,
395 &msft_opcode_fops);
396
397 if (IS_ENABLED(CONFIG_BT_AOSPEXT))
398 debugfs_create_file("aosp_capable", 0644, hdev->debugfs, data,
399 &aosp_capable_fops);
400
401 debugfs_create_file("force_devcoredump", 0644, hdev->debugfs, data,
402 &force_devcoredump_fops);
403}
404
405static int __vhci_create_device(struct vhci_data *data, __u8 opcode)
406{
407 struct hci_dev *hdev;
408 struct sk_buff *skb;
409
410 if (data->hdev)
411 return -EBADFD;
412
413 /* bits 2-5 are reserved (must be zero) */
414 if (opcode & 0x3c)
415 return -EINVAL;
416
417 skb = bt_skb_alloc(len: 4, GFP_KERNEL);
418 if (!skb)
419 return -ENOMEM;
420
421 hdev = hci_alloc_dev();
422 if (!hdev) {
423 kfree_skb(skb);
424 return -ENOMEM;
425 }
426
427 data->hdev = hdev;
428
429 hdev->bus = HCI_VIRTUAL;
430 hci_set_drvdata(hdev, data);
431
432 hdev->open = vhci_open_dev;
433 hdev->close = vhci_close_dev;
434 hdev->flush = vhci_flush;
435 hdev->send = vhci_send_frame;
436 hdev->get_data_path_id = vhci_get_data_path_id;
437 hdev->get_codec_config_data = vhci_get_codec_config_data;
438 hdev->wakeup = vhci_wakeup;
439 hdev->setup = vhci_setup;
440 hci_set_quirk(hdev, HCI_QUIRK_NON_PERSISTENT_SETUP);
441 hci_set_quirk(hdev, HCI_QUIRK_SYNC_FLOWCTL_SUPPORTED);
442
443 /* bit 6 is for external configuration */
444 if (opcode & 0x40)
445 hci_set_quirk(hdev, HCI_QUIRK_EXTERNAL_CONFIG);
446
447 /* bit 7 is for raw device */
448 if (opcode & 0x80)
449 hci_set_quirk(hdev, HCI_QUIRK_RAW_DEVICE);
450
451 if (hci_register_dev(hdev) < 0) {
452 BT_ERR("Can't register HCI device");
453 hci_free_dev(hdev);
454 data->hdev = NULL;
455 kfree_skb(skb);
456 return -EBUSY;
457 }
458
459 if (!IS_ERR_OR_NULL(ptr: hdev->debugfs))
460 vhci_debugfs_init(data);
461
462 hci_skb_pkt_type(skb) = HCI_VENDOR_PKT;
463
464 skb_put_u8(skb, val: 0xff);
465 skb_put_u8(skb, val: opcode);
466 put_unaligned_le16(val: hdev->id, p: skb_put(skb, len: 2));
467 skb_queue_head(list: &data->readq, newsk: skb);
468 atomic_inc(v: &data->initialized);
469
470 wake_up_interruptible(&data->read_wait);
471 return 0;
472}
473
474static int vhci_create_device(struct vhci_data *data, __u8 opcode)
475{
476 int err;
477
478 mutex_lock(&data->open_mutex);
479 err = __vhci_create_device(data, opcode);
480 mutex_unlock(lock: &data->open_mutex);
481
482 return err;
483}
484
485static inline ssize_t vhci_get_user(struct vhci_data *data,
486 struct iov_iter *from)
487{
488 size_t len = iov_iter_count(i: from);
489 struct sk_buff *skb;
490 __u8 pkt_type, opcode;
491 int ret;
492
493 if (len < 2 || len > HCI_MAX_FRAME_SIZE)
494 return -EINVAL;
495
496 skb = bt_skb_alloc(len, GFP_KERNEL);
497 if (!skb)
498 return -ENOMEM;
499
500 if (!copy_from_iter_full(addr: skb_put(skb, len), bytes: len, i: from)) {
501 kfree_skb(skb);
502 return -EFAULT;
503 }
504
505 pkt_type = *((__u8 *) skb->data);
506 skb_pull(skb, len: 1);
507
508 switch (pkt_type) {
509 case HCI_EVENT_PKT:
510 case HCI_ACLDATA_PKT:
511 case HCI_SCODATA_PKT:
512 case HCI_ISODATA_PKT:
513 if (!data->hdev) {
514 kfree_skb(skb);
515 return -ENODEV;
516 }
517
518 hci_skb_pkt_type(skb) = pkt_type;
519
520 ret = hci_recv_frame(hdev: data->hdev, skb);
521 break;
522
523 case HCI_VENDOR_PKT:
524 cancel_delayed_work_sync(dwork: &data->open_timeout);
525
526 opcode = *((__u8 *) skb->data);
527 skb_pull(skb, len: 1);
528
529 if (skb->len > 0) {
530 kfree_skb(skb);
531 return -EINVAL;
532 }
533
534 kfree_skb(skb);
535
536 ret = vhci_create_device(data, opcode);
537 break;
538
539 default:
540 kfree_skb(skb);
541 return -EINVAL;
542 }
543
544 return (ret < 0) ? ret : len;
545}
546
547static inline ssize_t vhci_put_user(struct vhci_data *data,
548 struct sk_buff *skb,
549 char __user *buf, int count)
550{
551 char __user *ptr = buf;
552 int len;
553
554 len = min_t(unsigned int, skb->len, count);
555
556 if (copy_to_user(to: ptr, from: skb->data, n: len))
557 return -EFAULT;
558
559 if (!data->hdev)
560 return len;
561
562 data->hdev->stat.byte_tx += len;
563
564 switch (hci_skb_pkt_type(skb)) {
565 case HCI_COMMAND_PKT:
566 data->hdev->stat.cmd_tx++;
567 break;
568 case HCI_ACLDATA_PKT:
569 data->hdev->stat.acl_tx++;
570 break;
571 case HCI_SCODATA_PKT:
572 data->hdev->stat.sco_tx++;
573 break;
574 }
575
576 return len;
577}
578
579static ssize_t vhci_read(struct file *file,
580 char __user *buf, size_t count, loff_t *pos)
581{
582 struct vhci_data *data = file->private_data;
583 struct sk_buff *skb;
584 ssize_t ret = 0;
585
586 while (count) {
587 skb = skb_dequeue(list: &data->readq);
588 if (skb) {
589 ret = vhci_put_user(data, skb, buf, count);
590 if (ret < 0)
591 skb_queue_head(list: &data->readq, newsk: skb);
592 else
593 kfree_skb(skb);
594 break;
595 }
596
597 if (file->f_flags & O_NONBLOCK) {
598 ret = -EAGAIN;
599 break;
600 }
601
602 ret = wait_event_interruptible(data->read_wait,
603 !skb_queue_empty(&data->readq));
604 if (ret < 0)
605 break;
606 }
607
608 return ret;
609}
610
611static ssize_t vhci_write(struct kiocb *iocb, struct iov_iter *from)
612{
613 struct file *file = iocb->ki_filp;
614 struct vhci_data *data = file->private_data;
615
616 return vhci_get_user(data, from);
617}
618
619static __poll_t vhci_poll(struct file *file, poll_table *wait)
620{
621 struct vhci_data *data = file->private_data;
622
623 poll_wait(filp: file, wait_address: &data->read_wait, p: wait);
624
625 if (!skb_queue_empty(list: &data->readq))
626 return EPOLLIN | EPOLLRDNORM;
627
628 return EPOLLOUT | EPOLLWRNORM;
629}
630
631static void vhci_open_timeout(struct work_struct *work)
632{
633 struct vhci_data *data = container_of(work, struct vhci_data,
634 open_timeout.work);
635
636 vhci_create_device(data, opcode: 0x00);
637}
638
639static int vhci_open(struct inode *inode, struct file *file)
640{
641 struct vhci_data *data;
642
643 data = kzalloc(sizeof(*data), GFP_KERNEL);
644 if (!data)
645 return -ENOMEM;
646
647 skb_queue_head_init(list: &data->readq);
648 init_waitqueue_head(&data->read_wait);
649
650 mutex_init(&data->open_mutex);
651 INIT_DELAYED_WORK(&data->open_timeout, vhci_open_timeout);
652 INIT_WORK(&data->suspend_work, vhci_suspend_work);
653
654 file->private_data = data;
655 nonseekable_open(inode, filp: file);
656
657 schedule_delayed_work(dwork: &data->open_timeout, secs_to_jiffies(1));
658
659 return 0;
660}
661
662static void vhci_debugfs_remove(struct hci_dev *hdev)
663{
664 debugfs_lookup_and_remove(name: "force_suspend", parent: hdev->debugfs);
665
666 debugfs_lookup_and_remove(name: "force_wakeup", parent: hdev->debugfs);
667
668 if (IS_ENABLED(CONFIG_BT_MSFTEXT))
669 debugfs_lookup_and_remove(name: "msft_opcode", parent: hdev->debugfs);
670
671 if (IS_ENABLED(CONFIG_BT_AOSPEXT))
672 debugfs_lookup_and_remove(name: "aosp_capable", parent: hdev->debugfs);
673
674 debugfs_lookup_and_remove(name: "force_devcoredump", parent: hdev->debugfs);
675}
676
677static int vhci_release(struct inode *inode, struct file *file)
678{
679 struct vhci_data *data = file->private_data;
680 struct hci_dev *hdev;
681
682 cancel_delayed_work_sync(dwork: &data->open_timeout);
683 flush_work(work: &data->suspend_work);
684
685 hdev = data->hdev;
686
687 if (hdev) {
688 if (!IS_ERR_OR_NULL(ptr: hdev->debugfs))
689 vhci_debugfs_remove(hdev);
690 hci_unregister_dev(hdev);
691 hci_free_dev(hdev);
692 }
693
694 skb_queue_purge(list: &data->readq);
695 file->private_data = NULL;
696 kfree(objp: data);
697
698 return 0;
699}
700
701static const struct file_operations vhci_fops = {
702 .owner = THIS_MODULE,
703 .read = vhci_read,
704 .write_iter = vhci_write,
705 .poll = vhci_poll,
706 .open = vhci_open,
707 .release = vhci_release,
708};
709
710static struct miscdevice vhci_miscdev = {
711 .name = "vhci",
712 .fops = &vhci_fops,
713 .minor = VHCI_MINOR,
714};
715module_misc_device(vhci_miscdev);
716
717module_param(amp, bool, 0644);
718MODULE_PARM_DESC(amp, "Create AMP controller device");
719
720MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
721MODULE_DESCRIPTION("Bluetooth virtual HCI driver ver " VERSION);
722MODULE_VERSION(VERSION);
723MODULE_LICENSE("GPL");
724MODULE_ALIAS("devname:vhci");
725MODULE_ALIAS_MISCDEV(VHCI_MINOR);
726

source code of linux/drivers/bluetooth/hci_vhci.c