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 49 static int vhci_open_dev(struct hci_dev *hdev) 50 { 51 return 0; 52 } 53 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 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 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 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 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 } 100 101 static bool vhci_wakeup(struct hci_dev *hdev) 102 { 103 struct vhci_data *data = hci_get_drvdata(hdev); 104 105 return data->wakeup; 106 } 107 108 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 } 119 120 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 } 130 131 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 }; 159 160 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 } 171 172 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 }; 198 199 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 } 213 214 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"); 225 226 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 } 237 238 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 }; 267 268 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 } 280 281 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 if (hci_register_dev(hdev) < 0) { 335 BT_ERR("Can't register HCI device"); 336 hci_free_dev(hdev); 337 data->hdev = NULL; 338 kfree_skb(skb); 339 return -EBUSY; 340 } 341 342 debugfs_create_file("force_suspend", 0644, hdev->debugfs, data, 343 &force_suspend_fops); 344 345 debugfs_create_file("force_wakeup", 0644, hdev->debugfs, data, 346 &force_wakeup_fops); 347 348 if (IS_ENABLED(CONFIG_BT_MSFTEXT)) 349 debugfs_create_file("msft_opcode", 0644, hdev->debugfs, data, 350 &msft_opcode_fops); 351 352 if (IS_ENABLED(CONFIG_BT_AOSPEXT)) 353 debugfs_create_file("aosp_capable", 0644, hdev->debugfs, data, 354 &aosp_capable_fops); 355 356 hci_skb_pkt_type(skb) = HCI_VENDOR_PKT; 357 358 skb_put_u8(skb, 0xff); 359 skb_put_u8(skb, opcode); 360 put_unaligned_le16(hdev->id, skb_put(skb, 2)); 361 skb_queue_tail(&data->readq, skb); 362 363 wake_up_interruptible(&data->read_wait); 364 return 0; 365 } 366 367 static int vhci_create_device(struct vhci_data *data, __u8 opcode) 368 { 369 int err; 370 371 mutex_lock(&data->open_mutex); 372 err = __vhci_create_device(data, opcode); 373 mutex_unlock(&data->open_mutex); 374 375 return err; 376 } 377 378 static inline ssize_t vhci_get_user(struct vhci_data *data, 379 struct iov_iter *from) 380 { 381 size_t len = iov_iter_count(from); 382 struct sk_buff *skb; 383 __u8 pkt_type, opcode; 384 int ret; 385 386 if (len < 2 || len > HCI_MAX_FRAME_SIZE) 387 return -EINVAL; 388 389 skb = bt_skb_alloc(len, GFP_KERNEL); 390 if (!skb) 391 return -ENOMEM; 392 393 if (!copy_from_iter_full(skb_put(skb, len), len, from)) { 394 kfree_skb(skb); 395 return -EFAULT; 396 } 397 398 pkt_type = *((__u8 *) skb->data); 399 skb_pull(skb, 1); 400 401 switch (pkt_type) { 402 case HCI_EVENT_PKT: 403 case HCI_ACLDATA_PKT: 404 case HCI_SCODATA_PKT: 405 case HCI_ISODATA_PKT: 406 if (!data->hdev) { 407 kfree_skb(skb); 408 return -ENODEV; 409 } 410 411 hci_skb_pkt_type(skb) = pkt_type; 412 413 ret = hci_recv_frame(data->hdev, skb); 414 break; 415 416 case HCI_VENDOR_PKT: 417 cancel_delayed_work_sync(&data->open_timeout); 418 419 opcode = *((__u8 *) skb->data); 420 skb_pull(skb, 1); 421 422 if (skb->len > 0) { 423 kfree_skb(skb); 424 return -EINVAL; 425 } 426 427 kfree_skb(skb); 428 429 ret = vhci_create_device(data, opcode); 430 break; 431 432 default: 433 kfree_skb(skb); 434 return -EINVAL; 435 } 436 437 return (ret < 0) ? ret : len; 438 } 439 440 static inline ssize_t vhci_put_user(struct vhci_data *data, 441 struct sk_buff *skb, 442 char __user *buf, int count) 443 { 444 char __user *ptr = buf; 445 int len; 446 447 len = min_t(unsigned int, skb->len, count); 448 449 if (copy_to_user(ptr, skb->data, len)) 450 return -EFAULT; 451 452 if (!data->hdev) 453 return len; 454 455 data->hdev->stat.byte_tx += len; 456 457 switch (hci_skb_pkt_type(skb)) { 458 case HCI_COMMAND_PKT: 459 data->hdev->stat.cmd_tx++; 460 break; 461 case HCI_ACLDATA_PKT: 462 data->hdev->stat.acl_tx++; 463 break; 464 case HCI_SCODATA_PKT: 465 data->hdev->stat.sco_tx++; 466 break; 467 } 468 469 return len; 470 } 471 472 static ssize_t vhci_read(struct file *file, 473 char __user *buf, size_t count, loff_t *pos) 474 { 475 struct vhci_data *data = file->private_data; 476 struct sk_buff *skb; 477 ssize_t ret = 0; 478 479 while (count) { 480 skb = skb_dequeue(&data->readq); 481 if (skb) { 482 ret = vhci_put_user(data, skb, buf, count); 483 if (ret < 0) 484 skb_queue_head(&data->readq, skb); 485 else 486 kfree_skb(skb); 487 break; 488 } 489 490 if (file->f_flags & O_NONBLOCK) { 491 ret = -EAGAIN; 492 break; 493 } 494 495 ret = wait_event_interruptible(data->read_wait, 496 !skb_queue_empty(&data->readq)); 497 if (ret < 0) 498 break; 499 } 500 501 return ret; 502 } 503 504 static ssize_t vhci_write(struct kiocb *iocb, struct iov_iter *from) 505 { 506 struct file *file = iocb->ki_filp; 507 struct vhci_data *data = file->private_data; 508 509 return vhci_get_user(data, from); 510 } 511 512 static __poll_t vhci_poll(struct file *file, poll_table *wait) 513 { 514 struct vhci_data *data = file->private_data; 515 516 poll_wait(file, &data->read_wait, wait); 517 518 if (!skb_queue_empty(&data->readq)) 519 return EPOLLIN | EPOLLRDNORM; 520 521 return EPOLLOUT | EPOLLWRNORM; 522 } 523 524 static void vhci_open_timeout(struct work_struct *work) 525 { 526 struct vhci_data *data = container_of(work, struct vhci_data, 527 open_timeout.work); 528 529 vhci_create_device(data, amp ? HCI_AMP : HCI_PRIMARY); 530 } 531 532 static int vhci_open(struct inode *inode, struct file *file) 533 { 534 struct vhci_data *data; 535 536 data = kzalloc(sizeof(struct vhci_data), GFP_KERNEL); 537 if (!data) 538 return -ENOMEM; 539 540 skb_queue_head_init(&data->readq); 541 init_waitqueue_head(&data->read_wait); 542 543 mutex_init(&data->open_mutex); 544 INIT_DELAYED_WORK(&data->open_timeout, vhci_open_timeout); 545 INIT_WORK(&data->suspend_work, vhci_suspend_work); 546 547 file->private_data = data; 548 nonseekable_open(inode, file); 549 550 schedule_delayed_work(&data->open_timeout, msecs_to_jiffies(1000)); 551 552 return 0; 553 } 554 555 static int vhci_release(struct inode *inode, struct file *file) 556 { 557 struct vhci_data *data = file->private_data; 558 struct hci_dev *hdev; 559 560 cancel_delayed_work_sync(&data->open_timeout); 561 flush_work(&data->suspend_work); 562 563 hdev = data->hdev; 564 565 if (hdev) { 566 hci_unregister_dev(hdev); 567 hci_free_dev(hdev); 568 } 569 570 skb_queue_purge(&data->readq); 571 file->private_data = NULL; 572 kfree(data); 573 574 return 0; 575 } 576 577 static const struct file_operations vhci_fops = { 578 .owner = THIS_MODULE, 579 .read = vhci_read, 580 .write_iter = vhci_write, 581 .poll = vhci_poll, 582 .open = vhci_open, 583 .release = vhci_release, 584 .llseek = no_llseek, 585 }; 586 587 static struct miscdevice vhci_miscdev = { 588 .name = "vhci", 589 .fops = &vhci_fops, 590 .minor = VHCI_MINOR, 591 }; 592 module_misc_device(vhci_miscdev); 593 594 module_param(amp, bool, 0644); 595 MODULE_PARM_DESC(amp, "Create AMP controller device"); 596 597 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>"); 598 MODULE_DESCRIPTION("Bluetooth virtual HCI driver ver " VERSION); 599 MODULE_VERSION(VERSION); 600 MODULE_LICENSE("GPL"); 601 MODULE_ALIAS("devname:vhci"); 602 MODULE_ALIAS_MISCDEV(VHCI_MINOR); 603