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 set_bit(HCI_QUIRK_VALID_LE_STATES, &hdev->quirks); 335 336 if (hci_register_dev(hdev) < 0) { 337 BT_ERR("Can't register HCI device"); 338 hci_free_dev(hdev); 339 data->hdev = NULL; 340 kfree_skb(skb); 341 return -EBUSY; 342 } 343 344 debugfs_create_file("force_suspend", 0644, hdev->debugfs, data, 345 &force_suspend_fops); 346 347 debugfs_create_file("force_wakeup", 0644, hdev->debugfs, data, 348 &force_wakeup_fops); 349 350 if (IS_ENABLED(CONFIG_BT_MSFTEXT)) 351 debugfs_create_file("msft_opcode", 0644, hdev->debugfs, data, 352 &msft_opcode_fops); 353 354 if (IS_ENABLED(CONFIG_BT_AOSPEXT)) 355 debugfs_create_file("aosp_capable", 0644, hdev->debugfs, data, 356 &aosp_capable_fops); 357 358 hci_skb_pkt_type(skb) = HCI_VENDOR_PKT; 359 360 skb_put_u8(skb, 0xff); 361 skb_put_u8(skb, opcode); 362 put_unaligned_le16(hdev->id, skb_put(skb, 2)); 363 skb_queue_tail(&data->readq, skb); 364 365 wake_up_interruptible(&data->read_wait); 366 return 0; 367 } 368 369 static int vhci_create_device(struct vhci_data *data, __u8 opcode) 370 { 371 int err; 372 373 mutex_lock(&data->open_mutex); 374 err = __vhci_create_device(data, opcode); 375 mutex_unlock(&data->open_mutex); 376 377 return err; 378 } 379 380 static inline ssize_t vhci_get_user(struct vhci_data *data, 381 struct iov_iter *from) 382 { 383 size_t len = iov_iter_count(from); 384 struct sk_buff *skb; 385 __u8 pkt_type, opcode; 386 int ret; 387 388 if (len < 2 || len > HCI_MAX_FRAME_SIZE) 389 return -EINVAL; 390 391 skb = bt_skb_alloc(len, GFP_KERNEL); 392 if (!skb) 393 return -ENOMEM; 394 395 if (!copy_from_iter_full(skb_put(skb, len), len, from)) { 396 kfree_skb(skb); 397 return -EFAULT; 398 } 399 400 pkt_type = *((__u8 *) skb->data); 401 skb_pull(skb, 1); 402 403 switch (pkt_type) { 404 case HCI_EVENT_PKT: 405 case HCI_ACLDATA_PKT: 406 case HCI_SCODATA_PKT: 407 case HCI_ISODATA_PKT: 408 if (!data->hdev) { 409 kfree_skb(skb); 410 return -ENODEV; 411 } 412 413 hci_skb_pkt_type(skb) = pkt_type; 414 415 ret = hci_recv_frame(data->hdev, skb); 416 break; 417 418 case HCI_VENDOR_PKT: 419 cancel_delayed_work_sync(&data->open_timeout); 420 421 opcode = *((__u8 *) skb->data); 422 skb_pull(skb, 1); 423 424 if (skb->len > 0) { 425 kfree_skb(skb); 426 return -EINVAL; 427 } 428 429 kfree_skb(skb); 430 431 ret = vhci_create_device(data, opcode); 432 break; 433 434 default: 435 kfree_skb(skb); 436 return -EINVAL; 437 } 438 439 return (ret < 0) ? ret : len; 440 } 441 442 static inline ssize_t vhci_put_user(struct vhci_data *data, 443 struct sk_buff *skb, 444 char __user *buf, int count) 445 { 446 char __user *ptr = buf; 447 int len; 448 449 len = min_t(unsigned int, skb->len, count); 450 451 if (copy_to_user(ptr, skb->data, len)) 452 return -EFAULT; 453 454 if (!data->hdev) 455 return len; 456 457 data->hdev->stat.byte_tx += len; 458 459 switch (hci_skb_pkt_type(skb)) { 460 case HCI_COMMAND_PKT: 461 data->hdev->stat.cmd_tx++; 462 break; 463 case HCI_ACLDATA_PKT: 464 data->hdev->stat.acl_tx++; 465 break; 466 case HCI_SCODATA_PKT: 467 data->hdev->stat.sco_tx++; 468 break; 469 } 470 471 return len; 472 } 473 474 static ssize_t vhci_read(struct file *file, 475 char __user *buf, size_t count, loff_t *pos) 476 { 477 struct vhci_data *data = file->private_data; 478 struct sk_buff *skb; 479 ssize_t ret = 0; 480 481 while (count) { 482 skb = skb_dequeue(&data->readq); 483 if (skb) { 484 ret = vhci_put_user(data, skb, buf, count); 485 if (ret < 0) 486 skb_queue_head(&data->readq, skb); 487 else 488 kfree_skb(skb); 489 break; 490 } 491 492 if (file->f_flags & O_NONBLOCK) { 493 ret = -EAGAIN; 494 break; 495 } 496 497 ret = wait_event_interruptible(data->read_wait, 498 !skb_queue_empty(&data->readq)); 499 if (ret < 0) 500 break; 501 } 502 503 return ret; 504 } 505 506 static ssize_t vhci_write(struct kiocb *iocb, struct iov_iter *from) 507 { 508 struct file *file = iocb->ki_filp; 509 struct vhci_data *data = file->private_data; 510 511 return vhci_get_user(data, from); 512 } 513 514 static __poll_t vhci_poll(struct file *file, poll_table *wait) 515 { 516 struct vhci_data *data = file->private_data; 517 518 poll_wait(file, &data->read_wait, wait); 519 520 if (!skb_queue_empty(&data->readq)) 521 return EPOLLIN | EPOLLRDNORM; 522 523 return EPOLLOUT | EPOLLWRNORM; 524 } 525 526 static void vhci_open_timeout(struct work_struct *work) 527 { 528 struct vhci_data *data = container_of(work, struct vhci_data, 529 open_timeout.work); 530 531 vhci_create_device(data, amp ? HCI_AMP : HCI_PRIMARY); 532 } 533 534 static int vhci_open(struct inode *inode, struct file *file) 535 { 536 struct vhci_data *data; 537 538 data = kzalloc(sizeof(struct vhci_data), GFP_KERNEL); 539 if (!data) 540 return -ENOMEM; 541 542 skb_queue_head_init(&data->readq); 543 init_waitqueue_head(&data->read_wait); 544 545 mutex_init(&data->open_mutex); 546 INIT_DELAYED_WORK(&data->open_timeout, vhci_open_timeout); 547 INIT_WORK(&data->suspend_work, vhci_suspend_work); 548 549 file->private_data = data; 550 nonseekable_open(inode, file); 551 552 schedule_delayed_work(&data->open_timeout, msecs_to_jiffies(1000)); 553 554 return 0; 555 } 556 557 static int vhci_release(struct inode *inode, struct file *file) 558 { 559 struct vhci_data *data = file->private_data; 560 struct hci_dev *hdev; 561 562 cancel_delayed_work_sync(&data->open_timeout); 563 flush_work(&data->suspend_work); 564 565 hdev = data->hdev; 566 567 if (hdev) { 568 hci_unregister_dev(hdev); 569 hci_free_dev(hdev); 570 } 571 572 skb_queue_purge(&data->readq); 573 file->private_data = NULL; 574 kfree(data); 575 576 return 0; 577 } 578 579 static const struct file_operations vhci_fops = { 580 .owner = THIS_MODULE, 581 .read = vhci_read, 582 .write_iter = vhci_write, 583 .poll = vhci_poll, 584 .open = vhci_open, 585 .release = vhci_release, 586 .llseek = no_llseek, 587 }; 588 589 static struct miscdevice vhci_miscdev = { 590 .name = "vhci", 591 .fops = &vhci_fops, 592 .minor = VHCI_MINOR, 593 }; 594 module_misc_device(vhci_miscdev); 595 596 module_param(amp, bool, 0644); 597 MODULE_PARM_DESC(amp, "Create AMP controller device"); 598 599 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>"); 600 MODULE_DESCRIPTION("Bluetooth virtual HCI driver ver " VERSION); 601 MODULE_VERSION(VERSION); 602 MODULE_LICENSE("GPL"); 603 MODULE_ALIAS("devname:vhci"); 604 MODULE_ALIAS_MISCDEV(VHCI_MINOR); 605