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 void vhci_coredump(struct hci_dev *hdev) 282 { 283 /* No need to do anything */ 284 } 285 286 static void vhci_coredump_hdr(struct hci_dev *hdev, struct sk_buff *skb) 287 { 288 char buf[80]; 289 290 snprintf(buf, sizeof(buf), "Controller Name: vhci_ctrl\n"); 291 skb_put_data(skb, buf, strlen(buf)); 292 293 snprintf(buf, sizeof(buf), "Firmware Version: vhci_fw\n"); 294 skb_put_data(skb, buf, strlen(buf)); 295 296 snprintf(buf, sizeof(buf), "Driver: vhci_drv\n"); 297 skb_put_data(skb, buf, strlen(buf)); 298 299 snprintf(buf, sizeof(buf), "Vendor: vhci\n"); 300 skb_put_data(skb, buf, strlen(buf)); 301 } 302 303 #define MAX_COREDUMP_LINE_LEN 40 304 305 struct devcoredump_test_data { 306 enum devcoredump_state state; 307 unsigned int timeout; 308 char data[MAX_COREDUMP_LINE_LEN]; 309 }; 310 311 static inline void force_devcd_timeout(struct hci_dev *hdev, 312 unsigned int timeout) 313 { 314 #ifdef CONFIG_DEV_COREDUMP 315 hdev->dump.timeout = msecs_to_jiffies(timeout * 1000); 316 #endif 317 } 318 319 static ssize_t force_devcd_write(struct file *file, const char __user *user_buf, 320 size_t count, loff_t *ppos) 321 { 322 struct vhci_data *data = file->private_data; 323 struct hci_dev *hdev = data->hdev; 324 struct sk_buff *skb = NULL; 325 struct devcoredump_test_data dump_data; 326 int ret; 327 328 ret = simple_write_to_buffer(&dump_data, sizeof(dump_data), ppos, 329 user_buf, count); 330 if (ret < count) 331 return ret; 332 333 skb = alloc_skb(sizeof(dump_data.data), GFP_ATOMIC); 334 if (!skb) 335 return -ENOMEM; 336 skb_put_data(skb, &dump_data.data, sizeof(dump_data.data)); 337 338 hci_devcd_register(hdev, vhci_coredump, vhci_coredump_hdr, NULL); 339 340 /* Force the devcoredump timeout */ 341 if (dump_data.timeout) 342 force_devcd_timeout(hdev, dump_data.timeout); 343 344 ret = hci_devcd_init(hdev, skb->len); 345 if (ret) { 346 BT_ERR("Failed to generate devcoredump"); 347 kfree_skb(skb); 348 return ret; 349 } 350 351 hci_devcd_append(hdev, skb); 352 353 switch (dump_data.state) { 354 case HCI_DEVCOREDUMP_DONE: 355 hci_devcd_complete(hdev); 356 break; 357 case HCI_DEVCOREDUMP_ABORT: 358 hci_devcd_abort(hdev); 359 break; 360 case HCI_DEVCOREDUMP_TIMEOUT: 361 /* Do nothing */ 362 break; 363 default: 364 return -EINVAL; 365 } 366 367 return count; 368 } 369 370 static const struct file_operations force_devcoredump_fops = { 371 .open = simple_open, 372 .write = force_devcd_write, 373 }; 374 375 static int __vhci_create_device(struct vhci_data *data, __u8 opcode) 376 { 377 struct hci_dev *hdev; 378 struct sk_buff *skb; 379 __u8 dev_type; 380 381 if (data->hdev) 382 return -EBADFD; 383 384 /* bits 0-1 are dev_type (Primary or AMP) */ 385 dev_type = opcode & 0x03; 386 387 if (dev_type != HCI_PRIMARY && dev_type != HCI_AMP) 388 return -EINVAL; 389 390 /* bits 2-5 are reserved (must be zero) */ 391 if (opcode & 0x3c) 392 return -EINVAL; 393 394 skb = bt_skb_alloc(4, GFP_KERNEL); 395 if (!skb) 396 return -ENOMEM; 397 398 hdev = hci_alloc_dev(); 399 if (!hdev) { 400 kfree_skb(skb); 401 return -ENOMEM; 402 } 403 404 data->hdev = hdev; 405 406 hdev->bus = HCI_VIRTUAL; 407 hdev->dev_type = dev_type; 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 set_bit(HCI_QUIRK_VALID_LE_STATES, &hdev->quirks); 429 430 if (hci_register_dev(hdev) < 0) { 431 BT_ERR("Can't register HCI device"); 432 hci_free_dev(hdev); 433 data->hdev = NULL; 434 kfree_skb(skb); 435 return -EBUSY; 436 } 437 438 debugfs_create_file("force_suspend", 0644, hdev->debugfs, data, 439 &force_suspend_fops); 440 441 debugfs_create_file("force_wakeup", 0644, hdev->debugfs, data, 442 &force_wakeup_fops); 443 444 if (IS_ENABLED(CONFIG_BT_MSFTEXT)) 445 debugfs_create_file("msft_opcode", 0644, hdev->debugfs, data, 446 &msft_opcode_fops); 447 448 if (IS_ENABLED(CONFIG_BT_AOSPEXT)) 449 debugfs_create_file("aosp_capable", 0644, hdev->debugfs, data, 450 &aosp_capable_fops); 451 452 debugfs_create_file("force_devcoredump", 0644, hdev->debugfs, data, 453 &force_devcoredump_fops); 454 455 hci_skb_pkt_type(skb) = HCI_VENDOR_PKT; 456 457 skb_put_u8(skb, 0xff); 458 skb_put_u8(skb, opcode); 459 put_unaligned_le16(hdev->id, skb_put(skb, 2)); 460 skb_queue_tail(&data->readq, skb); 461 462 wake_up_interruptible(&data->read_wait); 463 return 0; 464 } 465 466 static int vhci_create_device(struct vhci_data *data, __u8 opcode) 467 { 468 int err; 469 470 mutex_lock(&data->open_mutex); 471 err = __vhci_create_device(data, opcode); 472 mutex_unlock(&data->open_mutex); 473 474 return err; 475 } 476 477 static inline ssize_t vhci_get_user(struct vhci_data *data, 478 struct iov_iter *from) 479 { 480 size_t len = iov_iter_count(from); 481 struct sk_buff *skb; 482 __u8 pkt_type, opcode; 483 int ret; 484 485 if (len < 2 || len > HCI_MAX_FRAME_SIZE) 486 return -EINVAL; 487 488 skb = bt_skb_alloc(len, GFP_KERNEL); 489 if (!skb) 490 return -ENOMEM; 491 492 if (!copy_from_iter_full(skb_put(skb, len), len, from)) { 493 kfree_skb(skb); 494 return -EFAULT; 495 } 496 497 pkt_type = *((__u8 *) skb->data); 498 skb_pull(skb, 1); 499 500 switch (pkt_type) { 501 case HCI_EVENT_PKT: 502 case HCI_ACLDATA_PKT: 503 case HCI_SCODATA_PKT: 504 case HCI_ISODATA_PKT: 505 if (!data->hdev) { 506 kfree_skb(skb); 507 return -ENODEV; 508 } 509 510 hci_skb_pkt_type(skb) = pkt_type; 511 512 ret = hci_recv_frame(data->hdev, skb); 513 break; 514 515 case HCI_VENDOR_PKT: 516 cancel_delayed_work_sync(&data->open_timeout); 517 518 opcode = *((__u8 *) skb->data); 519 skb_pull(skb, 1); 520 521 if (skb->len > 0) { 522 kfree_skb(skb); 523 return -EINVAL; 524 } 525 526 kfree_skb(skb); 527 528 ret = vhci_create_device(data, opcode); 529 break; 530 531 default: 532 kfree_skb(skb); 533 return -EINVAL; 534 } 535 536 return (ret < 0) ? ret : len; 537 } 538 539 static inline ssize_t vhci_put_user(struct vhci_data *data, 540 struct sk_buff *skb, 541 char __user *buf, int count) 542 { 543 char __user *ptr = buf; 544 int len; 545 546 len = min_t(unsigned int, skb->len, count); 547 548 if (copy_to_user(ptr, skb->data, len)) 549 return -EFAULT; 550 551 if (!data->hdev) 552 return len; 553 554 data->hdev->stat.byte_tx += len; 555 556 switch (hci_skb_pkt_type(skb)) { 557 case HCI_COMMAND_PKT: 558 data->hdev->stat.cmd_tx++; 559 break; 560 case HCI_ACLDATA_PKT: 561 data->hdev->stat.acl_tx++; 562 break; 563 case HCI_SCODATA_PKT: 564 data->hdev->stat.sco_tx++; 565 break; 566 } 567 568 return len; 569 } 570 571 static ssize_t vhci_read(struct file *file, 572 char __user *buf, size_t count, loff_t *pos) 573 { 574 struct vhci_data *data = file->private_data; 575 struct sk_buff *skb; 576 ssize_t ret = 0; 577 578 while (count) { 579 skb = skb_dequeue(&data->readq); 580 if (skb) { 581 ret = vhci_put_user(data, skb, buf, count); 582 if (ret < 0) 583 skb_queue_head(&data->readq, skb); 584 else 585 kfree_skb(skb); 586 break; 587 } 588 589 if (file->f_flags & O_NONBLOCK) { 590 ret = -EAGAIN; 591 break; 592 } 593 594 ret = wait_event_interruptible(data->read_wait, 595 !skb_queue_empty(&data->readq)); 596 if (ret < 0) 597 break; 598 } 599 600 return ret; 601 } 602 603 static ssize_t vhci_write(struct kiocb *iocb, struct iov_iter *from) 604 { 605 struct file *file = iocb->ki_filp; 606 struct vhci_data *data = file->private_data; 607 608 return vhci_get_user(data, from); 609 } 610 611 static __poll_t vhci_poll(struct file *file, poll_table *wait) 612 { 613 struct vhci_data *data = file->private_data; 614 615 poll_wait(file, &data->read_wait, wait); 616 617 if (!skb_queue_empty(&data->readq)) 618 return EPOLLIN | EPOLLRDNORM; 619 620 return EPOLLOUT | EPOLLWRNORM; 621 } 622 623 static void vhci_open_timeout(struct work_struct *work) 624 { 625 struct vhci_data *data = container_of(work, struct vhci_data, 626 open_timeout.work); 627 628 vhci_create_device(data, amp ? HCI_AMP : HCI_PRIMARY); 629 } 630 631 static int vhci_open(struct inode *inode, struct file *file) 632 { 633 struct vhci_data *data; 634 635 data = kzalloc(sizeof(struct vhci_data), GFP_KERNEL); 636 if (!data) 637 return -ENOMEM; 638 639 skb_queue_head_init(&data->readq); 640 init_waitqueue_head(&data->read_wait); 641 642 mutex_init(&data->open_mutex); 643 INIT_DELAYED_WORK(&data->open_timeout, vhci_open_timeout); 644 INIT_WORK(&data->suspend_work, vhci_suspend_work); 645 646 file->private_data = data; 647 nonseekable_open(inode, file); 648 649 schedule_delayed_work(&data->open_timeout, msecs_to_jiffies(1000)); 650 651 return 0; 652 } 653 654 static int vhci_release(struct inode *inode, struct file *file) 655 { 656 struct vhci_data *data = file->private_data; 657 struct hci_dev *hdev; 658 659 cancel_delayed_work_sync(&data->open_timeout); 660 flush_work(&data->suspend_work); 661 662 hdev = data->hdev; 663 664 if (hdev) { 665 hci_unregister_dev(hdev); 666 hci_free_dev(hdev); 667 } 668 669 skb_queue_purge(&data->readq); 670 file->private_data = NULL; 671 kfree(data); 672 673 return 0; 674 } 675 676 static const struct file_operations vhci_fops = { 677 .owner = THIS_MODULE, 678 .read = vhci_read, 679 .write_iter = vhci_write, 680 .poll = vhci_poll, 681 .open = vhci_open, 682 .release = vhci_release, 683 .llseek = no_llseek, 684 }; 685 686 static struct miscdevice vhci_miscdev = { 687 .name = "vhci", 688 .fops = &vhci_fops, 689 .minor = VHCI_MINOR, 690 }; 691 module_misc_device(vhci_miscdev); 692 693 module_param(amp, bool, 0644); 694 MODULE_PARM_DESC(amp, "Create AMP controller device"); 695 696 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>"); 697 MODULE_DESCRIPTION("Bluetooth virtual HCI driver ver " VERSION); 698 MODULE_VERSION(VERSION); 699 MODULE_LICENSE("GPL"); 700 MODULE_ALIAS("devname:vhci"); 701 MODULE_ALIAS_MISCDEV(VHCI_MINOR); 702