1 /* 2 * f_fs.c -- user mode file system API for USB composite function controllers 3 * 4 * Copyright (C) 2010 Samsung Electronics 5 * Author: Michal Nazarewicz <mina86@mina86.com> 6 * 7 * Based on inode.c (GadgetFS) which was: 8 * Copyright (C) 2003-2004 David Brownell 9 * Copyright (C) 2003 Agilent Technologies 10 * 11 * This program is free software; you can redistribute it and/or modify 12 * it under the terms of the GNU General Public License as published by 13 * the Free Software Foundation; either version 2 of the License, or 14 * (at your option) any later version. 15 */ 16 17 18 /* #define DEBUG */ 19 /* #define VERBOSE_DEBUG */ 20 21 #include <linux/blkdev.h> 22 #include <linux/pagemap.h> 23 #include <linux/export.h> 24 #include <linux/hid.h> 25 #include <linux/module.h> 26 #include <linux/uio.h> 27 #include <asm/unaligned.h> 28 29 #include <linux/usb/composite.h> 30 #include <linux/usb/functionfs.h> 31 32 #include <linux/aio.h> 33 #include <linux/mmu_context.h> 34 #include <linux/poll.h> 35 #include <linux/eventfd.h> 36 37 #include "u_fs.h" 38 #include "u_f.h" 39 #include "u_os_desc.h" 40 #include "configfs.h" 41 42 #define FUNCTIONFS_MAGIC 0xa647361 /* Chosen by a honest dice roll ;) */ 43 44 /* Reference counter handling */ 45 static void ffs_data_get(struct ffs_data *ffs); 46 static void ffs_data_put(struct ffs_data *ffs); 47 /* Creates new ffs_data object. */ 48 static struct ffs_data *__must_check ffs_data_new(void) __attribute__((malloc)); 49 50 /* Opened counter handling. */ 51 static void ffs_data_opened(struct ffs_data *ffs); 52 static void ffs_data_closed(struct ffs_data *ffs); 53 54 /* Called with ffs->mutex held; take over ownership of data. */ 55 static int __must_check 56 __ffs_data_got_descs(struct ffs_data *ffs, char *data, size_t len); 57 static int __must_check 58 __ffs_data_got_strings(struct ffs_data *ffs, char *data, size_t len); 59 60 61 /* The function structure ***************************************************/ 62 63 struct ffs_ep; 64 65 struct ffs_function { 66 struct usb_configuration *conf; 67 struct usb_gadget *gadget; 68 struct ffs_data *ffs; 69 70 struct ffs_ep *eps; 71 u8 eps_revmap[16]; 72 short *interfaces_nums; 73 74 struct usb_function function; 75 }; 76 77 78 static struct ffs_function *ffs_func_from_usb(struct usb_function *f) 79 { 80 return container_of(f, struct ffs_function, function); 81 } 82 83 84 static inline enum ffs_setup_state 85 ffs_setup_state_clear_cancelled(struct ffs_data *ffs) 86 { 87 return (enum ffs_setup_state) 88 cmpxchg(&ffs->setup_state, FFS_SETUP_CANCELLED, FFS_NO_SETUP); 89 } 90 91 92 static void ffs_func_eps_disable(struct ffs_function *func); 93 static int __must_check ffs_func_eps_enable(struct ffs_function *func); 94 95 static int ffs_func_bind(struct usb_configuration *, 96 struct usb_function *); 97 static int ffs_func_set_alt(struct usb_function *, unsigned, unsigned); 98 static void ffs_func_disable(struct usb_function *); 99 static int ffs_func_setup(struct usb_function *, 100 const struct usb_ctrlrequest *); 101 static void ffs_func_suspend(struct usb_function *); 102 static void ffs_func_resume(struct usb_function *); 103 104 105 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num); 106 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf); 107 108 109 /* The endpoints structures *************************************************/ 110 111 struct ffs_ep { 112 struct usb_ep *ep; /* P: ffs->eps_lock */ 113 struct usb_request *req; /* P: epfile->mutex */ 114 115 /* [0]: full speed, [1]: high speed, [2]: super speed */ 116 struct usb_endpoint_descriptor *descs[3]; 117 118 u8 num; 119 120 int status; /* P: epfile->mutex */ 121 }; 122 123 struct ffs_epfile { 124 /* Protects ep->ep and ep->req. */ 125 struct mutex mutex; 126 wait_queue_head_t wait; 127 128 struct ffs_data *ffs; 129 struct ffs_ep *ep; /* P: ffs->eps_lock */ 130 131 struct dentry *dentry; 132 133 char name[5]; 134 135 unsigned char in; /* P: ffs->eps_lock */ 136 unsigned char isoc; /* P: ffs->eps_lock */ 137 138 unsigned char _pad; 139 }; 140 141 /* ffs_io_data structure ***************************************************/ 142 143 struct ffs_io_data { 144 bool aio; 145 bool read; 146 147 struct kiocb *kiocb; 148 struct iov_iter data; 149 const void *to_free; 150 char *buf; 151 152 struct mm_struct *mm; 153 struct work_struct work; 154 155 struct usb_ep *ep; 156 struct usb_request *req; 157 158 struct ffs_data *ffs; 159 }; 160 161 struct ffs_desc_helper { 162 struct ffs_data *ffs; 163 unsigned interfaces_count; 164 unsigned eps_count; 165 }; 166 167 static int __must_check ffs_epfiles_create(struct ffs_data *ffs); 168 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count); 169 170 static struct dentry * 171 ffs_sb_create_file(struct super_block *sb, const char *name, void *data, 172 const struct file_operations *fops); 173 174 /* Devices management *******************************************************/ 175 176 DEFINE_MUTEX(ffs_lock); 177 EXPORT_SYMBOL_GPL(ffs_lock); 178 179 static struct ffs_dev *_ffs_find_dev(const char *name); 180 static struct ffs_dev *_ffs_alloc_dev(void); 181 static int _ffs_name_dev(struct ffs_dev *dev, const char *name); 182 static void _ffs_free_dev(struct ffs_dev *dev); 183 static void *ffs_acquire_dev(const char *dev_name); 184 static void ffs_release_dev(struct ffs_data *ffs_data); 185 static int ffs_ready(struct ffs_data *ffs); 186 static void ffs_closed(struct ffs_data *ffs); 187 188 /* Misc helper functions ****************************************************/ 189 190 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock) 191 __attribute__((warn_unused_result, nonnull)); 192 static char *ffs_prepare_buffer(const char __user *buf, size_t len) 193 __attribute__((warn_unused_result, nonnull)); 194 195 196 /* Control file aka ep0 *****************************************************/ 197 198 static void ffs_ep0_complete(struct usb_ep *ep, struct usb_request *req) 199 { 200 struct ffs_data *ffs = req->context; 201 202 complete_all(&ffs->ep0req_completion); 203 } 204 205 static int __ffs_ep0_queue_wait(struct ffs_data *ffs, char *data, size_t len) 206 { 207 struct usb_request *req = ffs->ep0req; 208 int ret; 209 210 req->zero = len < le16_to_cpu(ffs->ev.setup.wLength); 211 212 spin_unlock_irq(&ffs->ev.waitq.lock); 213 214 req->buf = data; 215 req->length = len; 216 217 /* 218 * UDC layer requires to provide a buffer even for ZLP, but should 219 * not use it at all. Let's provide some poisoned pointer to catch 220 * possible bug in the driver. 221 */ 222 if (req->buf == NULL) 223 req->buf = (void *)0xDEADBABE; 224 225 reinit_completion(&ffs->ep0req_completion); 226 227 ret = usb_ep_queue(ffs->gadget->ep0, req, GFP_ATOMIC); 228 if (unlikely(ret < 0)) 229 return ret; 230 231 ret = wait_for_completion_interruptible(&ffs->ep0req_completion); 232 if (unlikely(ret)) { 233 usb_ep_dequeue(ffs->gadget->ep0, req); 234 return -EINTR; 235 } 236 237 ffs->setup_state = FFS_NO_SETUP; 238 return req->status ? req->status : req->actual; 239 } 240 241 static int __ffs_ep0_stall(struct ffs_data *ffs) 242 { 243 if (ffs->ev.can_stall) { 244 pr_vdebug("ep0 stall\n"); 245 usb_ep_set_halt(ffs->gadget->ep0); 246 ffs->setup_state = FFS_NO_SETUP; 247 return -EL2HLT; 248 } else { 249 pr_debug("bogus ep0 stall!\n"); 250 return -ESRCH; 251 } 252 } 253 254 static ssize_t ffs_ep0_write(struct file *file, const char __user *buf, 255 size_t len, loff_t *ptr) 256 { 257 struct ffs_data *ffs = file->private_data; 258 ssize_t ret; 259 char *data; 260 261 ENTER(); 262 263 /* Fast check if setup was canceled */ 264 if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED) 265 return -EIDRM; 266 267 /* Acquire mutex */ 268 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK); 269 if (unlikely(ret < 0)) 270 return ret; 271 272 /* Check state */ 273 switch (ffs->state) { 274 case FFS_READ_DESCRIPTORS: 275 case FFS_READ_STRINGS: 276 /* Copy data */ 277 if (unlikely(len < 16)) { 278 ret = -EINVAL; 279 break; 280 } 281 282 data = ffs_prepare_buffer(buf, len); 283 if (IS_ERR(data)) { 284 ret = PTR_ERR(data); 285 break; 286 } 287 288 /* Handle data */ 289 if (ffs->state == FFS_READ_DESCRIPTORS) { 290 pr_info("read descriptors\n"); 291 ret = __ffs_data_got_descs(ffs, data, len); 292 if (unlikely(ret < 0)) 293 break; 294 295 ffs->state = FFS_READ_STRINGS; 296 ret = len; 297 } else { 298 pr_info("read strings\n"); 299 ret = __ffs_data_got_strings(ffs, data, len); 300 if (unlikely(ret < 0)) 301 break; 302 303 ret = ffs_epfiles_create(ffs); 304 if (unlikely(ret)) { 305 ffs->state = FFS_CLOSING; 306 break; 307 } 308 309 ffs->state = FFS_ACTIVE; 310 mutex_unlock(&ffs->mutex); 311 312 ret = ffs_ready(ffs); 313 if (unlikely(ret < 0)) { 314 ffs->state = FFS_CLOSING; 315 return ret; 316 } 317 318 return len; 319 } 320 break; 321 322 case FFS_ACTIVE: 323 data = NULL; 324 /* 325 * We're called from user space, we can use _irq 326 * rather then _irqsave 327 */ 328 spin_lock_irq(&ffs->ev.waitq.lock); 329 switch (ffs_setup_state_clear_cancelled(ffs)) { 330 case FFS_SETUP_CANCELLED: 331 ret = -EIDRM; 332 goto done_spin; 333 334 case FFS_NO_SETUP: 335 ret = -ESRCH; 336 goto done_spin; 337 338 case FFS_SETUP_PENDING: 339 break; 340 } 341 342 /* FFS_SETUP_PENDING */ 343 if (!(ffs->ev.setup.bRequestType & USB_DIR_IN)) { 344 spin_unlock_irq(&ffs->ev.waitq.lock); 345 ret = __ffs_ep0_stall(ffs); 346 break; 347 } 348 349 /* FFS_SETUP_PENDING and not stall */ 350 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength)); 351 352 spin_unlock_irq(&ffs->ev.waitq.lock); 353 354 data = ffs_prepare_buffer(buf, len); 355 if (IS_ERR(data)) { 356 ret = PTR_ERR(data); 357 break; 358 } 359 360 spin_lock_irq(&ffs->ev.waitq.lock); 361 362 /* 363 * We are guaranteed to be still in FFS_ACTIVE state 364 * but the state of setup could have changed from 365 * FFS_SETUP_PENDING to FFS_SETUP_CANCELLED so we need 366 * to check for that. If that happened we copied data 367 * from user space in vain but it's unlikely. 368 * 369 * For sure we are not in FFS_NO_SETUP since this is 370 * the only place FFS_SETUP_PENDING -> FFS_NO_SETUP 371 * transition can be performed and it's protected by 372 * mutex. 373 */ 374 if (ffs_setup_state_clear_cancelled(ffs) == 375 FFS_SETUP_CANCELLED) { 376 ret = -EIDRM; 377 done_spin: 378 spin_unlock_irq(&ffs->ev.waitq.lock); 379 } else { 380 /* unlocks spinlock */ 381 ret = __ffs_ep0_queue_wait(ffs, data, len); 382 } 383 kfree(data); 384 break; 385 386 default: 387 ret = -EBADFD; 388 break; 389 } 390 391 mutex_unlock(&ffs->mutex); 392 return ret; 393 } 394 395 /* Called with ffs->ev.waitq.lock and ffs->mutex held, both released on exit. */ 396 static ssize_t __ffs_ep0_read_events(struct ffs_data *ffs, char __user *buf, 397 size_t n) 398 { 399 /* 400 * n cannot be bigger than ffs->ev.count, which cannot be bigger than 401 * size of ffs->ev.types array (which is four) so that's how much space 402 * we reserve. 403 */ 404 struct usb_functionfs_event events[ARRAY_SIZE(ffs->ev.types)]; 405 const size_t size = n * sizeof *events; 406 unsigned i = 0; 407 408 memset(events, 0, size); 409 410 do { 411 events[i].type = ffs->ev.types[i]; 412 if (events[i].type == FUNCTIONFS_SETUP) { 413 events[i].u.setup = ffs->ev.setup; 414 ffs->setup_state = FFS_SETUP_PENDING; 415 } 416 } while (++i < n); 417 418 ffs->ev.count -= n; 419 if (ffs->ev.count) 420 memmove(ffs->ev.types, ffs->ev.types + n, 421 ffs->ev.count * sizeof *ffs->ev.types); 422 423 spin_unlock_irq(&ffs->ev.waitq.lock); 424 mutex_unlock(&ffs->mutex); 425 426 return unlikely(__copy_to_user(buf, events, size)) ? -EFAULT : size; 427 } 428 429 static ssize_t ffs_ep0_read(struct file *file, char __user *buf, 430 size_t len, loff_t *ptr) 431 { 432 struct ffs_data *ffs = file->private_data; 433 char *data = NULL; 434 size_t n; 435 int ret; 436 437 ENTER(); 438 439 /* Fast check if setup was canceled */ 440 if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED) 441 return -EIDRM; 442 443 /* Acquire mutex */ 444 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK); 445 if (unlikely(ret < 0)) 446 return ret; 447 448 /* Check state */ 449 if (ffs->state != FFS_ACTIVE) { 450 ret = -EBADFD; 451 goto done_mutex; 452 } 453 454 /* 455 * We're called from user space, we can use _irq rather then 456 * _irqsave 457 */ 458 spin_lock_irq(&ffs->ev.waitq.lock); 459 460 switch (ffs_setup_state_clear_cancelled(ffs)) { 461 case FFS_SETUP_CANCELLED: 462 ret = -EIDRM; 463 break; 464 465 case FFS_NO_SETUP: 466 n = len / sizeof(struct usb_functionfs_event); 467 if (unlikely(!n)) { 468 ret = -EINVAL; 469 break; 470 } 471 472 if ((file->f_flags & O_NONBLOCK) && !ffs->ev.count) { 473 ret = -EAGAIN; 474 break; 475 } 476 477 if (wait_event_interruptible_exclusive_locked_irq(ffs->ev.waitq, 478 ffs->ev.count)) { 479 ret = -EINTR; 480 break; 481 } 482 483 return __ffs_ep0_read_events(ffs, buf, 484 min(n, (size_t)ffs->ev.count)); 485 486 case FFS_SETUP_PENDING: 487 if (ffs->ev.setup.bRequestType & USB_DIR_IN) { 488 spin_unlock_irq(&ffs->ev.waitq.lock); 489 ret = __ffs_ep0_stall(ffs); 490 goto done_mutex; 491 } 492 493 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength)); 494 495 spin_unlock_irq(&ffs->ev.waitq.lock); 496 497 if (likely(len)) { 498 data = kmalloc(len, GFP_KERNEL); 499 if (unlikely(!data)) { 500 ret = -ENOMEM; 501 goto done_mutex; 502 } 503 } 504 505 spin_lock_irq(&ffs->ev.waitq.lock); 506 507 /* See ffs_ep0_write() */ 508 if (ffs_setup_state_clear_cancelled(ffs) == 509 FFS_SETUP_CANCELLED) { 510 ret = -EIDRM; 511 break; 512 } 513 514 /* unlocks spinlock */ 515 ret = __ffs_ep0_queue_wait(ffs, data, len); 516 if (likely(ret > 0) && unlikely(__copy_to_user(buf, data, len))) 517 ret = -EFAULT; 518 goto done_mutex; 519 520 default: 521 ret = -EBADFD; 522 break; 523 } 524 525 spin_unlock_irq(&ffs->ev.waitq.lock); 526 done_mutex: 527 mutex_unlock(&ffs->mutex); 528 kfree(data); 529 return ret; 530 } 531 532 static int ffs_ep0_open(struct inode *inode, struct file *file) 533 { 534 struct ffs_data *ffs = inode->i_private; 535 536 ENTER(); 537 538 if (unlikely(ffs->state == FFS_CLOSING)) 539 return -EBUSY; 540 541 file->private_data = ffs; 542 ffs_data_opened(ffs); 543 544 return 0; 545 } 546 547 static int ffs_ep0_release(struct inode *inode, struct file *file) 548 { 549 struct ffs_data *ffs = file->private_data; 550 551 ENTER(); 552 553 ffs_data_closed(ffs); 554 555 return 0; 556 } 557 558 static long ffs_ep0_ioctl(struct file *file, unsigned code, unsigned long value) 559 { 560 struct ffs_data *ffs = file->private_data; 561 struct usb_gadget *gadget = ffs->gadget; 562 long ret; 563 564 ENTER(); 565 566 if (code == FUNCTIONFS_INTERFACE_REVMAP) { 567 struct ffs_function *func = ffs->func; 568 ret = func ? ffs_func_revmap_intf(func, value) : -ENODEV; 569 } else if (gadget && gadget->ops->ioctl) { 570 ret = gadget->ops->ioctl(gadget, code, value); 571 } else { 572 ret = -ENOTTY; 573 } 574 575 return ret; 576 } 577 578 static unsigned int ffs_ep0_poll(struct file *file, poll_table *wait) 579 { 580 struct ffs_data *ffs = file->private_data; 581 unsigned int mask = POLLWRNORM; 582 int ret; 583 584 poll_wait(file, &ffs->ev.waitq, wait); 585 586 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK); 587 if (unlikely(ret < 0)) 588 return mask; 589 590 switch (ffs->state) { 591 case FFS_READ_DESCRIPTORS: 592 case FFS_READ_STRINGS: 593 mask |= POLLOUT; 594 break; 595 596 case FFS_ACTIVE: 597 switch (ffs->setup_state) { 598 case FFS_NO_SETUP: 599 if (ffs->ev.count) 600 mask |= POLLIN; 601 break; 602 603 case FFS_SETUP_PENDING: 604 case FFS_SETUP_CANCELLED: 605 mask |= (POLLIN | POLLOUT); 606 break; 607 } 608 case FFS_CLOSING: 609 break; 610 case FFS_DEACTIVATED: 611 break; 612 } 613 614 mutex_unlock(&ffs->mutex); 615 616 return mask; 617 } 618 619 static const struct file_operations ffs_ep0_operations = { 620 .llseek = no_llseek, 621 622 .open = ffs_ep0_open, 623 .write = ffs_ep0_write, 624 .read = ffs_ep0_read, 625 .release = ffs_ep0_release, 626 .unlocked_ioctl = ffs_ep0_ioctl, 627 .poll = ffs_ep0_poll, 628 }; 629 630 631 /* "Normal" endpoints operations ********************************************/ 632 633 static void ffs_epfile_io_complete(struct usb_ep *_ep, struct usb_request *req) 634 { 635 ENTER(); 636 if (likely(req->context)) { 637 struct ffs_ep *ep = _ep->driver_data; 638 ep->status = req->status ? req->status : req->actual; 639 complete(req->context); 640 } 641 } 642 643 static void ffs_user_copy_worker(struct work_struct *work) 644 { 645 struct ffs_io_data *io_data = container_of(work, struct ffs_io_data, 646 work); 647 int ret = io_data->req->status ? io_data->req->status : 648 io_data->req->actual; 649 650 if (io_data->read && ret > 0) { 651 use_mm(io_data->mm); 652 ret = copy_to_iter(io_data->buf, ret, &io_data->data); 653 if (iov_iter_count(&io_data->data)) 654 ret = -EFAULT; 655 unuse_mm(io_data->mm); 656 } 657 658 io_data->kiocb->ki_complete(io_data->kiocb, ret, ret); 659 660 if (io_data->ffs->ffs_eventfd && 661 !(io_data->kiocb->ki_flags & IOCB_EVENTFD)) 662 eventfd_signal(io_data->ffs->ffs_eventfd, 1); 663 664 usb_ep_free_request(io_data->ep, io_data->req); 665 666 io_data->kiocb->private = NULL; 667 if (io_data->read) 668 kfree(io_data->to_free); 669 kfree(io_data->buf); 670 kfree(io_data); 671 } 672 673 static void ffs_epfile_async_io_complete(struct usb_ep *_ep, 674 struct usb_request *req) 675 { 676 struct ffs_io_data *io_data = req->context; 677 678 ENTER(); 679 680 INIT_WORK(&io_data->work, ffs_user_copy_worker); 681 schedule_work(&io_data->work); 682 } 683 684 static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data) 685 { 686 struct ffs_epfile *epfile = file->private_data; 687 struct ffs_ep *ep; 688 char *data = NULL; 689 ssize_t ret, data_len = -EINVAL; 690 int halt; 691 692 /* Are we still active? */ 693 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) { 694 ret = -ENODEV; 695 goto error; 696 } 697 698 /* Wait for endpoint to be enabled */ 699 ep = epfile->ep; 700 if (!ep) { 701 if (file->f_flags & O_NONBLOCK) { 702 ret = -EAGAIN; 703 goto error; 704 } 705 706 ret = wait_event_interruptible(epfile->wait, (ep = epfile->ep)); 707 if (ret) { 708 ret = -EINTR; 709 goto error; 710 } 711 } 712 713 /* Do we halt? */ 714 halt = (!io_data->read == !epfile->in); 715 if (halt && epfile->isoc) { 716 ret = -EINVAL; 717 goto error; 718 } 719 720 /* Allocate & copy */ 721 if (!halt) { 722 /* 723 * if we _do_ wait above, the epfile->ffs->gadget might be NULL 724 * before the waiting completes, so do not assign to 'gadget' earlier 725 */ 726 struct usb_gadget *gadget = epfile->ffs->gadget; 727 size_t copied; 728 729 spin_lock_irq(&epfile->ffs->eps_lock); 730 /* In the meantime, endpoint got disabled or changed. */ 731 if (epfile->ep != ep) { 732 spin_unlock_irq(&epfile->ffs->eps_lock); 733 return -ESHUTDOWN; 734 } 735 data_len = iov_iter_count(&io_data->data); 736 /* 737 * Controller may require buffer size to be aligned to 738 * maxpacketsize of an out endpoint. 739 */ 740 if (io_data->read) 741 data_len = usb_ep_align_maybe(gadget, ep->ep, data_len); 742 spin_unlock_irq(&epfile->ffs->eps_lock); 743 744 data = kmalloc(data_len, GFP_KERNEL); 745 if (unlikely(!data)) 746 return -ENOMEM; 747 if (!io_data->read) { 748 copied = copy_from_iter(data, data_len, &io_data->data); 749 if (copied != data_len) { 750 ret = -EFAULT; 751 goto error; 752 } 753 } 754 } 755 756 /* We will be using request */ 757 ret = ffs_mutex_lock(&epfile->mutex, file->f_flags & O_NONBLOCK); 758 if (unlikely(ret)) 759 goto error; 760 761 spin_lock_irq(&epfile->ffs->eps_lock); 762 763 if (epfile->ep != ep) { 764 /* In the meantime, endpoint got disabled or changed. */ 765 ret = -ESHUTDOWN; 766 spin_unlock_irq(&epfile->ffs->eps_lock); 767 } else if (halt) { 768 /* Halt */ 769 if (likely(epfile->ep == ep) && !WARN_ON(!ep->ep)) 770 usb_ep_set_halt(ep->ep); 771 spin_unlock_irq(&epfile->ffs->eps_lock); 772 ret = -EBADMSG; 773 } else { 774 /* Fire the request */ 775 struct usb_request *req; 776 777 /* 778 * Sanity Check: even though data_len can't be used 779 * uninitialized at the time I write this comment, some 780 * compilers complain about this situation. 781 * In order to keep the code clean from warnings, data_len is 782 * being initialized to -EINVAL during its declaration, which 783 * means we can't rely on compiler anymore to warn no future 784 * changes won't result in data_len being used uninitialized. 785 * For such reason, we're adding this redundant sanity check 786 * here. 787 */ 788 if (unlikely(data_len == -EINVAL)) { 789 WARN(1, "%s: data_len == -EINVAL\n", __func__); 790 ret = -EINVAL; 791 goto error_lock; 792 } 793 794 if (io_data->aio) { 795 req = usb_ep_alloc_request(ep->ep, GFP_KERNEL); 796 if (unlikely(!req)) 797 goto error_lock; 798 799 req->buf = data; 800 req->length = data_len; 801 802 io_data->buf = data; 803 io_data->ep = ep->ep; 804 io_data->req = req; 805 io_data->ffs = epfile->ffs; 806 807 req->context = io_data; 808 req->complete = ffs_epfile_async_io_complete; 809 810 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC); 811 if (unlikely(ret)) { 812 usb_ep_free_request(ep->ep, req); 813 goto error_lock; 814 } 815 ret = -EIOCBQUEUED; 816 817 spin_unlock_irq(&epfile->ffs->eps_lock); 818 } else { 819 DECLARE_COMPLETION_ONSTACK(done); 820 821 req = ep->req; 822 req->buf = data; 823 req->length = data_len; 824 825 req->context = &done; 826 req->complete = ffs_epfile_io_complete; 827 828 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC); 829 830 spin_unlock_irq(&epfile->ffs->eps_lock); 831 832 if (unlikely(ret < 0)) { 833 /* nop */ 834 } else if (unlikely( 835 wait_for_completion_interruptible(&done))) { 836 ret = -EINTR; 837 usb_ep_dequeue(ep->ep, req); 838 } else { 839 /* 840 * XXX We may end up silently droping data 841 * here. Since data_len (i.e. req->length) may 842 * be bigger than len (after being rounded up 843 * to maxpacketsize), we may end up with more 844 * data then user space has space for. 845 */ 846 ret = ep->status; 847 if (io_data->read && ret > 0) { 848 ret = copy_to_iter(data, ret, &io_data->data); 849 if (!ret) 850 ret = -EFAULT; 851 } 852 } 853 kfree(data); 854 } 855 } 856 857 mutex_unlock(&epfile->mutex); 858 return ret; 859 860 error_lock: 861 spin_unlock_irq(&epfile->ffs->eps_lock); 862 mutex_unlock(&epfile->mutex); 863 error: 864 kfree(data); 865 return ret; 866 } 867 868 static int 869 ffs_epfile_open(struct inode *inode, struct file *file) 870 { 871 struct ffs_epfile *epfile = inode->i_private; 872 873 ENTER(); 874 875 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) 876 return -ENODEV; 877 878 file->private_data = epfile; 879 ffs_data_opened(epfile->ffs); 880 881 return 0; 882 } 883 884 static int ffs_aio_cancel(struct kiocb *kiocb) 885 { 886 struct ffs_io_data *io_data = kiocb->private; 887 struct ffs_epfile *epfile = kiocb->ki_filp->private_data; 888 int value; 889 890 ENTER(); 891 892 spin_lock_irq(&epfile->ffs->eps_lock); 893 894 if (likely(io_data && io_data->ep && io_data->req)) 895 value = usb_ep_dequeue(io_data->ep, io_data->req); 896 else 897 value = -EINVAL; 898 899 spin_unlock_irq(&epfile->ffs->eps_lock); 900 901 return value; 902 } 903 904 static ssize_t ffs_epfile_write_iter(struct kiocb *kiocb, struct iov_iter *from) 905 { 906 struct ffs_io_data io_data, *p = &io_data; 907 ssize_t res; 908 909 ENTER(); 910 911 if (!is_sync_kiocb(kiocb)) { 912 p = kmalloc(sizeof(io_data), GFP_KERNEL); 913 if (unlikely(!p)) 914 return -ENOMEM; 915 p->aio = true; 916 } else { 917 p->aio = false; 918 } 919 920 p->read = false; 921 p->kiocb = kiocb; 922 p->data = *from; 923 p->mm = current->mm; 924 925 kiocb->private = p; 926 927 if (p->aio) 928 kiocb_set_cancel_fn(kiocb, ffs_aio_cancel); 929 930 res = ffs_epfile_io(kiocb->ki_filp, p); 931 if (res == -EIOCBQUEUED) 932 return res; 933 if (p->aio) 934 kfree(p); 935 else 936 *from = p->data; 937 return res; 938 } 939 940 static ssize_t ffs_epfile_read_iter(struct kiocb *kiocb, struct iov_iter *to) 941 { 942 struct ffs_io_data io_data, *p = &io_data; 943 ssize_t res; 944 945 ENTER(); 946 947 if (!is_sync_kiocb(kiocb)) { 948 p = kmalloc(sizeof(io_data), GFP_KERNEL); 949 if (unlikely(!p)) 950 return -ENOMEM; 951 p->aio = true; 952 } else { 953 p->aio = false; 954 } 955 956 p->read = true; 957 p->kiocb = kiocb; 958 if (p->aio) { 959 p->to_free = dup_iter(&p->data, to, GFP_KERNEL); 960 if (!p->to_free) { 961 kfree(p); 962 return -ENOMEM; 963 } 964 } else { 965 p->data = *to; 966 p->to_free = NULL; 967 } 968 p->mm = current->mm; 969 970 kiocb->private = p; 971 972 if (p->aio) 973 kiocb_set_cancel_fn(kiocb, ffs_aio_cancel); 974 975 res = ffs_epfile_io(kiocb->ki_filp, p); 976 if (res == -EIOCBQUEUED) 977 return res; 978 979 if (p->aio) { 980 kfree(p->to_free); 981 kfree(p); 982 } else { 983 *to = p->data; 984 } 985 return res; 986 } 987 988 static int 989 ffs_epfile_release(struct inode *inode, struct file *file) 990 { 991 struct ffs_epfile *epfile = inode->i_private; 992 993 ENTER(); 994 995 ffs_data_closed(epfile->ffs); 996 997 return 0; 998 } 999 1000 static long ffs_epfile_ioctl(struct file *file, unsigned code, 1001 unsigned long value) 1002 { 1003 struct ffs_epfile *epfile = file->private_data; 1004 int ret; 1005 1006 ENTER(); 1007 1008 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) 1009 return -ENODEV; 1010 1011 spin_lock_irq(&epfile->ffs->eps_lock); 1012 if (likely(epfile->ep)) { 1013 switch (code) { 1014 case FUNCTIONFS_FIFO_STATUS: 1015 ret = usb_ep_fifo_status(epfile->ep->ep); 1016 break; 1017 case FUNCTIONFS_FIFO_FLUSH: 1018 usb_ep_fifo_flush(epfile->ep->ep); 1019 ret = 0; 1020 break; 1021 case FUNCTIONFS_CLEAR_HALT: 1022 ret = usb_ep_clear_halt(epfile->ep->ep); 1023 break; 1024 case FUNCTIONFS_ENDPOINT_REVMAP: 1025 ret = epfile->ep->num; 1026 break; 1027 case FUNCTIONFS_ENDPOINT_DESC: 1028 { 1029 int desc_idx; 1030 struct usb_endpoint_descriptor *desc; 1031 1032 switch (epfile->ffs->gadget->speed) { 1033 case USB_SPEED_SUPER: 1034 desc_idx = 2; 1035 break; 1036 case USB_SPEED_HIGH: 1037 desc_idx = 1; 1038 break; 1039 default: 1040 desc_idx = 0; 1041 } 1042 desc = epfile->ep->descs[desc_idx]; 1043 1044 spin_unlock_irq(&epfile->ffs->eps_lock); 1045 ret = copy_to_user((void *)value, desc, sizeof(*desc)); 1046 if (ret) 1047 ret = -EFAULT; 1048 return ret; 1049 } 1050 default: 1051 ret = -ENOTTY; 1052 } 1053 } else { 1054 ret = -ENODEV; 1055 } 1056 spin_unlock_irq(&epfile->ffs->eps_lock); 1057 1058 return ret; 1059 } 1060 1061 static const struct file_operations ffs_epfile_operations = { 1062 .llseek = no_llseek, 1063 1064 .open = ffs_epfile_open, 1065 .write_iter = ffs_epfile_write_iter, 1066 .read_iter = ffs_epfile_read_iter, 1067 .release = ffs_epfile_release, 1068 .unlocked_ioctl = ffs_epfile_ioctl, 1069 }; 1070 1071 1072 /* File system and super block operations ***********************************/ 1073 1074 /* 1075 * Mounting the file system creates a controller file, used first for 1076 * function configuration then later for event monitoring. 1077 */ 1078 1079 static struct inode *__must_check 1080 ffs_sb_make_inode(struct super_block *sb, void *data, 1081 const struct file_operations *fops, 1082 const struct inode_operations *iops, 1083 struct ffs_file_perms *perms) 1084 { 1085 struct inode *inode; 1086 1087 ENTER(); 1088 1089 inode = new_inode(sb); 1090 1091 if (likely(inode)) { 1092 struct timespec current_time = CURRENT_TIME; 1093 1094 inode->i_ino = get_next_ino(); 1095 inode->i_mode = perms->mode; 1096 inode->i_uid = perms->uid; 1097 inode->i_gid = perms->gid; 1098 inode->i_atime = current_time; 1099 inode->i_mtime = current_time; 1100 inode->i_ctime = current_time; 1101 inode->i_private = data; 1102 if (fops) 1103 inode->i_fop = fops; 1104 if (iops) 1105 inode->i_op = iops; 1106 } 1107 1108 return inode; 1109 } 1110 1111 /* Create "regular" file */ 1112 static struct dentry *ffs_sb_create_file(struct super_block *sb, 1113 const char *name, void *data, 1114 const struct file_operations *fops) 1115 { 1116 struct ffs_data *ffs = sb->s_fs_info; 1117 struct dentry *dentry; 1118 struct inode *inode; 1119 1120 ENTER(); 1121 1122 dentry = d_alloc_name(sb->s_root, name); 1123 if (unlikely(!dentry)) 1124 return NULL; 1125 1126 inode = ffs_sb_make_inode(sb, data, fops, NULL, &ffs->file_perms); 1127 if (unlikely(!inode)) { 1128 dput(dentry); 1129 return NULL; 1130 } 1131 1132 d_add(dentry, inode); 1133 return dentry; 1134 } 1135 1136 /* Super block */ 1137 static const struct super_operations ffs_sb_operations = { 1138 .statfs = simple_statfs, 1139 .drop_inode = generic_delete_inode, 1140 }; 1141 1142 struct ffs_sb_fill_data { 1143 struct ffs_file_perms perms; 1144 umode_t root_mode; 1145 const char *dev_name; 1146 bool no_disconnect; 1147 struct ffs_data *ffs_data; 1148 }; 1149 1150 static int ffs_sb_fill(struct super_block *sb, void *_data, int silent) 1151 { 1152 struct ffs_sb_fill_data *data = _data; 1153 struct inode *inode; 1154 struct ffs_data *ffs = data->ffs_data; 1155 1156 ENTER(); 1157 1158 ffs->sb = sb; 1159 data->ffs_data = NULL; 1160 sb->s_fs_info = ffs; 1161 sb->s_blocksize = PAGE_CACHE_SIZE; 1162 sb->s_blocksize_bits = PAGE_CACHE_SHIFT; 1163 sb->s_magic = FUNCTIONFS_MAGIC; 1164 sb->s_op = &ffs_sb_operations; 1165 sb->s_time_gran = 1; 1166 1167 /* Root inode */ 1168 data->perms.mode = data->root_mode; 1169 inode = ffs_sb_make_inode(sb, NULL, 1170 &simple_dir_operations, 1171 &simple_dir_inode_operations, 1172 &data->perms); 1173 sb->s_root = d_make_root(inode); 1174 if (unlikely(!sb->s_root)) 1175 return -ENOMEM; 1176 1177 /* EP0 file */ 1178 if (unlikely(!ffs_sb_create_file(sb, "ep0", ffs, 1179 &ffs_ep0_operations))) 1180 return -ENOMEM; 1181 1182 return 0; 1183 } 1184 1185 static int ffs_fs_parse_opts(struct ffs_sb_fill_data *data, char *opts) 1186 { 1187 ENTER(); 1188 1189 if (!opts || !*opts) 1190 return 0; 1191 1192 for (;;) { 1193 unsigned long value; 1194 char *eq, *comma; 1195 1196 /* Option limit */ 1197 comma = strchr(opts, ','); 1198 if (comma) 1199 *comma = 0; 1200 1201 /* Value limit */ 1202 eq = strchr(opts, '='); 1203 if (unlikely(!eq)) { 1204 pr_err("'=' missing in %s\n", opts); 1205 return -EINVAL; 1206 } 1207 *eq = 0; 1208 1209 /* Parse value */ 1210 if (kstrtoul(eq + 1, 0, &value)) { 1211 pr_err("%s: invalid value: %s\n", opts, eq + 1); 1212 return -EINVAL; 1213 } 1214 1215 /* Interpret option */ 1216 switch (eq - opts) { 1217 case 13: 1218 if (!memcmp(opts, "no_disconnect", 13)) 1219 data->no_disconnect = !!value; 1220 else 1221 goto invalid; 1222 break; 1223 case 5: 1224 if (!memcmp(opts, "rmode", 5)) 1225 data->root_mode = (value & 0555) | S_IFDIR; 1226 else if (!memcmp(opts, "fmode", 5)) 1227 data->perms.mode = (value & 0666) | S_IFREG; 1228 else 1229 goto invalid; 1230 break; 1231 1232 case 4: 1233 if (!memcmp(opts, "mode", 4)) { 1234 data->root_mode = (value & 0555) | S_IFDIR; 1235 data->perms.mode = (value & 0666) | S_IFREG; 1236 } else { 1237 goto invalid; 1238 } 1239 break; 1240 1241 case 3: 1242 if (!memcmp(opts, "uid", 3)) { 1243 data->perms.uid = make_kuid(current_user_ns(), value); 1244 if (!uid_valid(data->perms.uid)) { 1245 pr_err("%s: unmapped value: %lu\n", opts, value); 1246 return -EINVAL; 1247 } 1248 } else if (!memcmp(opts, "gid", 3)) { 1249 data->perms.gid = make_kgid(current_user_ns(), value); 1250 if (!gid_valid(data->perms.gid)) { 1251 pr_err("%s: unmapped value: %lu\n", opts, value); 1252 return -EINVAL; 1253 } 1254 } else { 1255 goto invalid; 1256 } 1257 break; 1258 1259 default: 1260 invalid: 1261 pr_err("%s: invalid option\n", opts); 1262 return -EINVAL; 1263 } 1264 1265 /* Next iteration */ 1266 if (!comma) 1267 break; 1268 opts = comma + 1; 1269 } 1270 1271 return 0; 1272 } 1273 1274 /* "mount -t functionfs dev_name /dev/function" ends up here */ 1275 1276 static struct dentry * 1277 ffs_fs_mount(struct file_system_type *t, int flags, 1278 const char *dev_name, void *opts) 1279 { 1280 struct ffs_sb_fill_data data = { 1281 .perms = { 1282 .mode = S_IFREG | 0600, 1283 .uid = GLOBAL_ROOT_UID, 1284 .gid = GLOBAL_ROOT_GID, 1285 }, 1286 .root_mode = S_IFDIR | 0500, 1287 .no_disconnect = false, 1288 }; 1289 struct dentry *rv; 1290 int ret; 1291 void *ffs_dev; 1292 struct ffs_data *ffs; 1293 1294 ENTER(); 1295 1296 ret = ffs_fs_parse_opts(&data, opts); 1297 if (unlikely(ret < 0)) 1298 return ERR_PTR(ret); 1299 1300 ffs = ffs_data_new(); 1301 if (unlikely(!ffs)) 1302 return ERR_PTR(-ENOMEM); 1303 ffs->file_perms = data.perms; 1304 ffs->no_disconnect = data.no_disconnect; 1305 1306 ffs->dev_name = kstrdup(dev_name, GFP_KERNEL); 1307 if (unlikely(!ffs->dev_name)) { 1308 ffs_data_put(ffs); 1309 return ERR_PTR(-ENOMEM); 1310 } 1311 1312 ffs_dev = ffs_acquire_dev(dev_name); 1313 if (IS_ERR(ffs_dev)) { 1314 ffs_data_put(ffs); 1315 return ERR_CAST(ffs_dev); 1316 } 1317 ffs->private_data = ffs_dev; 1318 data.ffs_data = ffs; 1319 1320 rv = mount_nodev(t, flags, &data, ffs_sb_fill); 1321 if (IS_ERR(rv) && data.ffs_data) { 1322 ffs_release_dev(data.ffs_data); 1323 ffs_data_put(data.ffs_data); 1324 } 1325 return rv; 1326 } 1327 1328 static void 1329 ffs_fs_kill_sb(struct super_block *sb) 1330 { 1331 ENTER(); 1332 1333 kill_litter_super(sb); 1334 if (sb->s_fs_info) { 1335 ffs_release_dev(sb->s_fs_info); 1336 ffs_data_closed(sb->s_fs_info); 1337 ffs_data_put(sb->s_fs_info); 1338 } 1339 } 1340 1341 static struct file_system_type ffs_fs_type = { 1342 .owner = THIS_MODULE, 1343 .name = "functionfs", 1344 .mount = ffs_fs_mount, 1345 .kill_sb = ffs_fs_kill_sb, 1346 }; 1347 MODULE_ALIAS_FS("functionfs"); 1348 1349 1350 /* Driver's main init/cleanup functions *************************************/ 1351 1352 static int functionfs_init(void) 1353 { 1354 int ret; 1355 1356 ENTER(); 1357 1358 ret = register_filesystem(&ffs_fs_type); 1359 if (likely(!ret)) 1360 pr_info("file system registered\n"); 1361 else 1362 pr_err("failed registering file system (%d)\n", ret); 1363 1364 return ret; 1365 } 1366 1367 static void functionfs_cleanup(void) 1368 { 1369 ENTER(); 1370 1371 pr_info("unloading\n"); 1372 unregister_filesystem(&ffs_fs_type); 1373 } 1374 1375 1376 /* ffs_data and ffs_function construction and destruction code **************/ 1377 1378 static void ffs_data_clear(struct ffs_data *ffs); 1379 static void ffs_data_reset(struct ffs_data *ffs); 1380 1381 static void ffs_data_get(struct ffs_data *ffs) 1382 { 1383 ENTER(); 1384 1385 atomic_inc(&ffs->ref); 1386 } 1387 1388 static void ffs_data_opened(struct ffs_data *ffs) 1389 { 1390 ENTER(); 1391 1392 atomic_inc(&ffs->ref); 1393 if (atomic_add_return(1, &ffs->opened) == 1 && 1394 ffs->state == FFS_DEACTIVATED) { 1395 ffs->state = FFS_CLOSING; 1396 ffs_data_reset(ffs); 1397 } 1398 } 1399 1400 static void ffs_data_put(struct ffs_data *ffs) 1401 { 1402 ENTER(); 1403 1404 if (unlikely(atomic_dec_and_test(&ffs->ref))) { 1405 pr_info("%s(): freeing\n", __func__); 1406 ffs_data_clear(ffs); 1407 BUG_ON(waitqueue_active(&ffs->ev.waitq) || 1408 waitqueue_active(&ffs->ep0req_completion.wait)); 1409 kfree(ffs->dev_name); 1410 kfree(ffs); 1411 } 1412 } 1413 1414 static void ffs_data_closed(struct ffs_data *ffs) 1415 { 1416 ENTER(); 1417 1418 if (atomic_dec_and_test(&ffs->opened)) { 1419 if (ffs->no_disconnect) { 1420 ffs->state = FFS_DEACTIVATED; 1421 if (ffs->epfiles) { 1422 ffs_epfiles_destroy(ffs->epfiles, 1423 ffs->eps_count); 1424 ffs->epfiles = NULL; 1425 } 1426 if (ffs->setup_state == FFS_SETUP_PENDING) 1427 __ffs_ep0_stall(ffs); 1428 } else { 1429 ffs->state = FFS_CLOSING; 1430 ffs_data_reset(ffs); 1431 } 1432 } 1433 if (atomic_read(&ffs->opened) < 0) { 1434 ffs->state = FFS_CLOSING; 1435 ffs_data_reset(ffs); 1436 } 1437 1438 ffs_data_put(ffs); 1439 } 1440 1441 static struct ffs_data *ffs_data_new(void) 1442 { 1443 struct ffs_data *ffs = kzalloc(sizeof *ffs, GFP_KERNEL); 1444 if (unlikely(!ffs)) 1445 return NULL; 1446 1447 ENTER(); 1448 1449 atomic_set(&ffs->ref, 1); 1450 atomic_set(&ffs->opened, 0); 1451 ffs->state = FFS_READ_DESCRIPTORS; 1452 mutex_init(&ffs->mutex); 1453 spin_lock_init(&ffs->eps_lock); 1454 init_waitqueue_head(&ffs->ev.waitq); 1455 init_completion(&ffs->ep0req_completion); 1456 1457 /* XXX REVISIT need to update it in some places, or do we? */ 1458 ffs->ev.can_stall = 1; 1459 1460 return ffs; 1461 } 1462 1463 static void ffs_data_clear(struct ffs_data *ffs) 1464 { 1465 ENTER(); 1466 1467 ffs_closed(ffs); 1468 1469 BUG_ON(ffs->gadget); 1470 1471 if (ffs->epfiles) 1472 ffs_epfiles_destroy(ffs->epfiles, ffs->eps_count); 1473 1474 if (ffs->ffs_eventfd) 1475 eventfd_ctx_put(ffs->ffs_eventfd); 1476 1477 kfree(ffs->raw_descs_data); 1478 kfree(ffs->raw_strings); 1479 kfree(ffs->stringtabs); 1480 } 1481 1482 static void ffs_data_reset(struct ffs_data *ffs) 1483 { 1484 ENTER(); 1485 1486 ffs_data_clear(ffs); 1487 1488 ffs->epfiles = NULL; 1489 ffs->raw_descs_data = NULL; 1490 ffs->raw_descs = NULL; 1491 ffs->raw_strings = NULL; 1492 ffs->stringtabs = NULL; 1493 1494 ffs->raw_descs_length = 0; 1495 ffs->fs_descs_count = 0; 1496 ffs->hs_descs_count = 0; 1497 ffs->ss_descs_count = 0; 1498 1499 ffs->strings_count = 0; 1500 ffs->interfaces_count = 0; 1501 ffs->eps_count = 0; 1502 1503 ffs->ev.count = 0; 1504 1505 ffs->state = FFS_READ_DESCRIPTORS; 1506 ffs->setup_state = FFS_NO_SETUP; 1507 ffs->flags = 0; 1508 } 1509 1510 1511 static int functionfs_bind(struct ffs_data *ffs, struct usb_composite_dev *cdev) 1512 { 1513 struct usb_gadget_strings **lang; 1514 int first_id; 1515 1516 ENTER(); 1517 1518 if (WARN_ON(ffs->state != FFS_ACTIVE 1519 || test_and_set_bit(FFS_FL_BOUND, &ffs->flags))) 1520 return -EBADFD; 1521 1522 first_id = usb_string_ids_n(cdev, ffs->strings_count); 1523 if (unlikely(first_id < 0)) 1524 return first_id; 1525 1526 ffs->ep0req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL); 1527 if (unlikely(!ffs->ep0req)) 1528 return -ENOMEM; 1529 ffs->ep0req->complete = ffs_ep0_complete; 1530 ffs->ep0req->context = ffs; 1531 1532 lang = ffs->stringtabs; 1533 if (lang) { 1534 for (; *lang; ++lang) { 1535 struct usb_string *str = (*lang)->strings; 1536 int id = first_id; 1537 for (; str->s; ++id, ++str) 1538 str->id = id; 1539 } 1540 } 1541 1542 ffs->gadget = cdev->gadget; 1543 ffs_data_get(ffs); 1544 return 0; 1545 } 1546 1547 static void functionfs_unbind(struct ffs_data *ffs) 1548 { 1549 ENTER(); 1550 1551 if (!WARN_ON(!ffs->gadget)) { 1552 usb_ep_free_request(ffs->gadget->ep0, ffs->ep0req); 1553 ffs->ep0req = NULL; 1554 ffs->gadget = NULL; 1555 clear_bit(FFS_FL_BOUND, &ffs->flags); 1556 ffs_data_put(ffs); 1557 } 1558 } 1559 1560 static int ffs_epfiles_create(struct ffs_data *ffs) 1561 { 1562 struct ffs_epfile *epfile, *epfiles; 1563 unsigned i, count; 1564 1565 ENTER(); 1566 1567 count = ffs->eps_count; 1568 epfiles = kcalloc(count, sizeof(*epfiles), GFP_KERNEL); 1569 if (!epfiles) 1570 return -ENOMEM; 1571 1572 epfile = epfiles; 1573 for (i = 1; i <= count; ++i, ++epfile) { 1574 epfile->ffs = ffs; 1575 mutex_init(&epfile->mutex); 1576 init_waitqueue_head(&epfile->wait); 1577 if (ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR) 1578 sprintf(epfile->name, "ep%02x", ffs->eps_addrmap[i]); 1579 else 1580 sprintf(epfile->name, "ep%u", i); 1581 epfile->dentry = ffs_sb_create_file(ffs->sb, epfile->name, 1582 epfile, 1583 &ffs_epfile_operations); 1584 if (unlikely(!epfile->dentry)) { 1585 ffs_epfiles_destroy(epfiles, i - 1); 1586 return -ENOMEM; 1587 } 1588 } 1589 1590 ffs->epfiles = epfiles; 1591 return 0; 1592 } 1593 1594 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count) 1595 { 1596 struct ffs_epfile *epfile = epfiles; 1597 1598 ENTER(); 1599 1600 for (; count; --count, ++epfile) { 1601 BUG_ON(mutex_is_locked(&epfile->mutex) || 1602 waitqueue_active(&epfile->wait)); 1603 if (epfile->dentry) { 1604 d_delete(epfile->dentry); 1605 dput(epfile->dentry); 1606 epfile->dentry = NULL; 1607 } 1608 } 1609 1610 kfree(epfiles); 1611 } 1612 1613 static void ffs_func_eps_disable(struct ffs_function *func) 1614 { 1615 struct ffs_ep *ep = func->eps; 1616 struct ffs_epfile *epfile = func->ffs->epfiles; 1617 unsigned count = func->ffs->eps_count; 1618 unsigned long flags; 1619 1620 spin_lock_irqsave(&func->ffs->eps_lock, flags); 1621 do { 1622 /* pending requests get nuked */ 1623 if (likely(ep->ep)) 1624 usb_ep_disable(ep->ep); 1625 ++ep; 1626 1627 if (epfile) { 1628 epfile->ep = NULL; 1629 ++epfile; 1630 } 1631 } while (--count); 1632 spin_unlock_irqrestore(&func->ffs->eps_lock, flags); 1633 } 1634 1635 static int ffs_func_eps_enable(struct ffs_function *func) 1636 { 1637 struct ffs_data *ffs = func->ffs; 1638 struct ffs_ep *ep = func->eps; 1639 struct ffs_epfile *epfile = ffs->epfiles; 1640 unsigned count = ffs->eps_count; 1641 unsigned long flags; 1642 int ret = 0; 1643 1644 spin_lock_irqsave(&func->ffs->eps_lock, flags); 1645 do { 1646 struct usb_endpoint_descriptor *ds; 1647 int desc_idx; 1648 1649 if (ffs->gadget->speed == USB_SPEED_SUPER) 1650 desc_idx = 2; 1651 else if (ffs->gadget->speed == USB_SPEED_HIGH) 1652 desc_idx = 1; 1653 else 1654 desc_idx = 0; 1655 1656 /* fall-back to lower speed if desc missing for current speed */ 1657 do { 1658 ds = ep->descs[desc_idx]; 1659 } while (!ds && --desc_idx >= 0); 1660 1661 if (!ds) { 1662 ret = -EINVAL; 1663 break; 1664 } 1665 1666 ep->ep->driver_data = ep; 1667 ep->ep->desc = ds; 1668 ret = usb_ep_enable(ep->ep); 1669 if (likely(!ret)) { 1670 epfile->ep = ep; 1671 epfile->in = usb_endpoint_dir_in(ds); 1672 epfile->isoc = usb_endpoint_xfer_isoc(ds); 1673 } else { 1674 break; 1675 } 1676 1677 wake_up(&epfile->wait); 1678 1679 ++ep; 1680 ++epfile; 1681 } while (--count); 1682 spin_unlock_irqrestore(&func->ffs->eps_lock, flags); 1683 1684 return ret; 1685 } 1686 1687 1688 /* Parsing and building descriptors and strings *****************************/ 1689 1690 /* 1691 * This validates if data pointed by data is a valid USB descriptor as 1692 * well as record how many interfaces, endpoints and strings are 1693 * required by given configuration. Returns address after the 1694 * descriptor or NULL if data is invalid. 1695 */ 1696 1697 enum ffs_entity_type { 1698 FFS_DESCRIPTOR, FFS_INTERFACE, FFS_STRING, FFS_ENDPOINT 1699 }; 1700 1701 enum ffs_os_desc_type { 1702 FFS_OS_DESC, FFS_OS_DESC_EXT_COMPAT, FFS_OS_DESC_EXT_PROP 1703 }; 1704 1705 typedef int (*ffs_entity_callback)(enum ffs_entity_type entity, 1706 u8 *valuep, 1707 struct usb_descriptor_header *desc, 1708 void *priv); 1709 1710 typedef int (*ffs_os_desc_callback)(enum ffs_os_desc_type entity, 1711 struct usb_os_desc_header *h, void *data, 1712 unsigned len, void *priv); 1713 1714 static int __must_check ffs_do_single_desc(char *data, unsigned len, 1715 ffs_entity_callback entity, 1716 void *priv) 1717 { 1718 struct usb_descriptor_header *_ds = (void *)data; 1719 u8 length; 1720 int ret; 1721 1722 ENTER(); 1723 1724 /* At least two bytes are required: length and type */ 1725 if (len < 2) { 1726 pr_vdebug("descriptor too short\n"); 1727 return -EINVAL; 1728 } 1729 1730 /* If we have at least as many bytes as the descriptor takes? */ 1731 length = _ds->bLength; 1732 if (len < length) { 1733 pr_vdebug("descriptor longer then available data\n"); 1734 return -EINVAL; 1735 } 1736 1737 #define __entity_check_INTERFACE(val) 1 1738 #define __entity_check_STRING(val) (val) 1739 #define __entity_check_ENDPOINT(val) ((val) & USB_ENDPOINT_NUMBER_MASK) 1740 #define __entity(type, val) do { \ 1741 pr_vdebug("entity " #type "(%02x)\n", (val)); \ 1742 if (unlikely(!__entity_check_ ##type(val))) { \ 1743 pr_vdebug("invalid entity's value\n"); \ 1744 return -EINVAL; \ 1745 } \ 1746 ret = entity(FFS_ ##type, &val, _ds, priv); \ 1747 if (unlikely(ret < 0)) { \ 1748 pr_debug("entity " #type "(%02x); ret = %d\n", \ 1749 (val), ret); \ 1750 return ret; \ 1751 } \ 1752 } while (0) 1753 1754 /* Parse descriptor depending on type. */ 1755 switch (_ds->bDescriptorType) { 1756 case USB_DT_DEVICE: 1757 case USB_DT_CONFIG: 1758 case USB_DT_STRING: 1759 case USB_DT_DEVICE_QUALIFIER: 1760 /* function can't have any of those */ 1761 pr_vdebug("descriptor reserved for gadget: %d\n", 1762 _ds->bDescriptorType); 1763 return -EINVAL; 1764 1765 case USB_DT_INTERFACE: { 1766 struct usb_interface_descriptor *ds = (void *)_ds; 1767 pr_vdebug("interface descriptor\n"); 1768 if (length != sizeof *ds) 1769 goto inv_length; 1770 1771 __entity(INTERFACE, ds->bInterfaceNumber); 1772 if (ds->iInterface) 1773 __entity(STRING, ds->iInterface); 1774 } 1775 break; 1776 1777 case USB_DT_ENDPOINT: { 1778 struct usb_endpoint_descriptor *ds = (void *)_ds; 1779 pr_vdebug("endpoint descriptor\n"); 1780 if (length != USB_DT_ENDPOINT_SIZE && 1781 length != USB_DT_ENDPOINT_AUDIO_SIZE) 1782 goto inv_length; 1783 __entity(ENDPOINT, ds->bEndpointAddress); 1784 } 1785 break; 1786 1787 case HID_DT_HID: 1788 pr_vdebug("hid descriptor\n"); 1789 if (length != sizeof(struct hid_descriptor)) 1790 goto inv_length; 1791 break; 1792 1793 case USB_DT_OTG: 1794 if (length != sizeof(struct usb_otg_descriptor)) 1795 goto inv_length; 1796 break; 1797 1798 case USB_DT_INTERFACE_ASSOCIATION: { 1799 struct usb_interface_assoc_descriptor *ds = (void *)_ds; 1800 pr_vdebug("interface association descriptor\n"); 1801 if (length != sizeof *ds) 1802 goto inv_length; 1803 if (ds->iFunction) 1804 __entity(STRING, ds->iFunction); 1805 } 1806 break; 1807 1808 case USB_DT_SS_ENDPOINT_COMP: 1809 pr_vdebug("EP SS companion descriptor\n"); 1810 if (length != sizeof(struct usb_ss_ep_comp_descriptor)) 1811 goto inv_length; 1812 break; 1813 1814 case USB_DT_OTHER_SPEED_CONFIG: 1815 case USB_DT_INTERFACE_POWER: 1816 case USB_DT_DEBUG: 1817 case USB_DT_SECURITY: 1818 case USB_DT_CS_RADIO_CONTROL: 1819 /* TODO */ 1820 pr_vdebug("unimplemented descriptor: %d\n", _ds->bDescriptorType); 1821 return -EINVAL; 1822 1823 default: 1824 /* We should never be here */ 1825 pr_vdebug("unknown descriptor: %d\n", _ds->bDescriptorType); 1826 return -EINVAL; 1827 1828 inv_length: 1829 pr_vdebug("invalid length: %d (descriptor %d)\n", 1830 _ds->bLength, _ds->bDescriptorType); 1831 return -EINVAL; 1832 } 1833 1834 #undef __entity 1835 #undef __entity_check_DESCRIPTOR 1836 #undef __entity_check_INTERFACE 1837 #undef __entity_check_STRING 1838 #undef __entity_check_ENDPOINT 1839 1840 return length; 1841 } 1842 1843 static int __must_check ffs_do_descs(unsigned count, char *data, unsigned len, 1844 ffs_entity_callback entity, void *priv) 1845 { 1846 const unsigned _len = len; 1847 unsigned long num = 0; 1848 1849 ENTER(); 1850 1851 for (;;) { 1852 int ret; 1853 1854 if (num == count) 1855 data = NULL; 1856 1857 /* Record "descriptor" entity */ 1858 ret = entity(FFS_DESCRIPTOR, (u8 *)num, (void *)data, priv); 1859 if (unlikely(ret < 0)) { 1860 pr_debug("entity DESCRIPTOR(%02lx); ret = %d\n", 1861 num, ret); 1862 return ret; 1863 } 1864 1865 if (!data) 1866 return _len - len; 1867 1868 ret = ffs_do_single_desc(data, len, entity, priv); 1869 if (unlikely(ret < 0)) { 1870 pr_debug("%s returns %d\n", __func__, ret); 1871 return ret; 1872 } 1873 1874 len -= ret; 1875 data += ret; 1876 ++num; 1877 } 1878 } 1879 1880 static int __ffs_data_do_entity(enum ffs_entity_type type, 1881 u8 *valuep, struct usb_descriptor_header *desc, 1882 void *priv) 1883 { 1884 struct ffs_desc_helper *helper = priv; 1885 struct usb_endpoint_descriptor *d; 1886 1887 ENTER(); 1888 1889 switch (type) { 1890 case FFS_DESCRIPTOR: 1891 break; 1892 1893 case FFS_INTERFACE: 1894 /* 1895 * Interfaces are indexed from zero so if we 1896 * encountered interface "n" then there are at least 1897 * "n+1" interfaces. 1898 */ 1899 if (*valuep >= helper->interfaces_count) 1900 helper->interfaces_count = *valuep + 1; 1901 break; 1902 1903 case FFS_STRING: 1904 /* 1905 * Strings are indexed from 1 (0 is magic ;) reserved 1906 * for languages list or some such) 1907 */ 1908 if (*valuep > helper->ffs->strings_count) 1909 helper->ffs->strings_count = *valuep; 1910 break; 1911 1912 case FFS_ENDPOINT: 1913 d = (void *)desc; 1914 helper->eps_count++; 1915 if (helper->eps_count >= 15) 1916 return -EINVAL; 1917 /* Check if descriptors for any speed were already parsed */ 1918 if (!helper->ffs->eps_count && !helper->ffs->interfaces_count) 1919 helper->ffs->eps_addrmap[helper->eps_count] = 1920 d->bEndpointAddress; 1921 else if (helper->ffs->eps_addrmap[helper->eps_count] != 1922 d->bEndpointAddress) 1923 return -EINVAL; 1924 break; 1925 } 1926 1927 return 0; 1928 } 1929 1930 static int __ffs_do_os_desc_header(enum ffs_os_desc_type *next_type, 1931 struct usb_os_desc_header *desc) 1932 { 1933 u16 bcd_version = le16_to_cpu(desc->bcdVersion); 1934 u16 w_index = le16_to_cpu(desc->wIndex); 1935 1936 if (bcd_version != 1) { 1937 pr_vdebug("unsupported os descriptors version: %d", 1938 bcd_version); 1939 return -EINVAL; 1940 } 1941 switch (w_index) { 1942 case 0x4: 1943 *next_type = FFS_OS_DESC_EXT_COMPAT; 1944 break; 1945 case 0x5: 1946 *next_type = FFS_OS_DESC_EXT_PROP; 1947 break; 1948 default: 1949 pr_vdebug("unsupported os descriptor type: %d", w_index); 1950 return -EINVAL; 1951 } 1952 1953 return sizeof(*desc); 1954 } 1955 1956 /* 1957 * Process all extended compatibility/extended property descriptors 1958 * of a feature descriptor 1959 */ 1960 static int __must_check ffs_do_single_os_desc(char *data, unsigned len, 1961 enum ffs_os_desc_type type, 1962 u16 feature_count, 1963 ffs_os_desc_callback entity, 1964 void *priv, 1965 struct usb_os_desc_header *h) 1966 { 1967 int ret; 1968 const unsigned _len = len; 1969 1970 ENTER(); 1971 1972 /* loop over all ext compat/ext prop descriptors */ 1973 while (feature_count--) { 1974 ret = entity(type, h, data, len, priv); 1975 if (unlikely(ret < 0)) { 1976 pr_debug("bad OS descriptor, type: %d\n", type); 1977 return ret; 1978 } 1979 data += ret; 1980 len -= ret; 1981 } 1982 return _len - len; 1983 } 1984 1985 /* Process a number of complete Feature Descriptors (Ext Compat or Ext Prop) */ 1986 static int __must_check ffs_do_os_descs(unsigned count, 1987 char *data, unsigned len, 1988 ffs_os_desc_callback entity, void *priv) 1989 { 1990 const unsigned _len = len; 1991 unsigned long num = 0; 1992 1993 ENTER(); 1994 1995 for (num = 0; num < count; ++num) { 1996 int ret; 1997 enum ffs_os_desc_type type; 1998 u16 feature_count; 1999 struct usb_os_desc_header *desc = (void *)data; 2000 2001 if (len < sizeof(*desc)) 2002 return -EINVAL; 2003 2004 /* 2005 * Record "descriptor" entity. 2006 * Process dwLength, bcdVersion, wIndex, get b/wCount. 2007 * Move the data pointer to the beginning of extended 2008 * compatibilities proper or extended properties proper 2009 * portions of the data 2010 */ 2011 if (le32_to_cpu(desc->dwLength) > len) 2012 return -EINVAL; 2013 2014 ret = __ffs_do_os_desc_header(&type, desc); 2015 if (unlikely(ret < 0)) { 2016 pr_debug("entity OS_DESCRIPTOR(%02lx); ret = %d\n", 2017 num, ret); 2018 return ret; 2019 } 2020 /* 2021 * 16-bit hex "?? 00" Little Endian looks like 8-bit hex "??" 2022 */ 2023 feature_count = le16_to_cpu(desc->wCount); 2024 if (type == FFS_OS_DESC_EXT_COMPAT && 2025 (feature_count > 255 || desc->Reserved)) 2026 return -EINVAL; 2027 len -= ret; 2028 data += ret; 2029 2030 /* 2031 * Process all function/property descriptors 2032 * of this Feature Descriptor 2033 */ 2034 ret = ffs_do_single_os_desc(data, len, type, 2035 feature_count, entity, priv, desc); 2036 if (unlikely(ret < 0)) { 2037 pr_debug("%s returns %d\n", __func__, ret); 2038 return ret; 2039 } 2040 2041 len -= ret; 2042 data += ret; 2043 } 2044 return _len - len; 2045 } 2046 2047 /** 2048 * Validate contents of the buffer from userspace related to OS descriptors. 2049 */ 2050 static int __ffs_data_do_os_desc(enum ffs_os_desc_type type, 2051 struct usb_os_desc_header *h, void *data, 2052 unsigned len, void *priv) 2053 { 2054 struct ffs_data *ffs = priv; 2055 u8 length; 2056 2057 ENTER(); 2058 2059 switch (type) { 2060 case FFS_OS_DESC_EXT_COMPAT: { 2061 struct usb_ext_compat_desc *d = data; 2062 int i; 2063 2064 if (len < sizeof(*d) || 2065 d->bFirstInterfaceNumber >= ffs->interfaces_count || 2066 d->Reserved1) 2067 return -EINVAL; 2068 for (i = 0; i < ARRAY_SIZE(d->Reserved2); ++i) 2069 if (d->Reserved2[i]) 2070 return -EINVAL; 2071 2072 length = sizeof(struct usb_ext_compat_desc); 2073 } 2074 break; 2075 case FFS_OS_DESC_EXT_PROP: { 2076 struct usb_ext_prop_desc *d = data; 2077 u32 type, pdl; 2078 u16 pnl; 2079 2080 if (len < sizeof(*d) || h->interface >= ffs->interfaces_count) 2081 return -EINVAL; 2082 length = le32_to_cpu(d->dwSize); 2083 type = le32_to_cpu(d->dwPropertyDataType); 2084 if (type < USB_EXT_PROP_UNICODE || 2085 type > USB_EXT_PROP_UNICODE_MULTI) { 2086 pr_vdebug("unsupported os descriptor property type: %d", 2087 type); 2088 return -EINVAL; 2089 } 2090 pnl = le16_to_cpu(d->wPropertyNameLength); 2091 pdl = le32_to_cpu(*(u32 *)((u8 *)data + 10 + pnl)); 2092 if (length != 14 + pnl + pdl) { 2093 pr_vdebug("invalid os descriptor length: %d pnl:%d pdl:%d (descriptor %d)\n", 2094 length, pnl, pdl, type); 2095 return -EINVAL; 2096 } 2097 ++ffs->ms_os_descs_ext_prop_count; 2098 /* property name reported to the host as "WCHAR"s */ 2099 ffs->ms_os_descs_ext_prop_name_len += pnl * 2; 2100 ffs->ms_os_descs_ext_prop_data_len += pdl; 2101 } 2102 break; 2103 default: 2104 pr_vdebug("unknown descriptor: %d\n", type); 2105 return -EINVAL; 2106 } 2107 return length; 2108 } 2109 2110 static int __ffs_data_got_descs(struct ffs_data *ffs, 2111 char *const _data, size_t len) 2112 { 2113 char *data = _data, *raw_descs; 2114 unsigned os_descs_count = 0, counts[3], flags; 2115 int ret = -EINVAL, i; 2116 struct ffs_desc_helper helper; 2117 2118 ENTER(); 2119 2120 if (get_unaligned_le32(data + 4) != len) 2121 goto error; 2122 2123 switch (get_unaligned_le32(data)) { 2124 case FUNCTIONFS_DESCRIPTORS_MAGIC: 2125 flags = FUNCTIONFS_HAS_FS_DESC | FUNCTIONFS_HAS_HS_DESC; 2126 data += 8; 2127 len -= 8; 2128 break; 2129 case FUNCTIONFS_DESCRIPTORS_MAGIC_V2: 2130 flags = get_unaligned_le32(data + 8); 2131 ffs->user_flags = flags; 2132 if (flags & ~(FUNCTIONFS_HAS_FS_DESC | 2133 FUNCTIONFS_HAS_HS_DESC | 2134 FUNCTIONFS_HAS_SS_DESC | 2135 FUNCTIONFS_HAS_MS_OS_DESC | 2136 FUNCTIONFS_VIRTUAL_ADDR | 2137 FUNCTIONFS_EVENTFD)) { 2138 ret = -ENOSYS; 2139 goto error; 2140 } 2141 data += 12; 2142 len -= 12; 2143 break; 2144 default: 2145 goto error; 2146 } 2147 2148 if (flags & FUNCTIONFS_EVENTFD) { 2149 if (len < 4) 2150 goto error; 2151 ffs->ffs_eventfd = 2152 eventfd_ctx_fdget((int)get_unaligned_le32(data)); 2153 if (IS_ERR(ffs->ffs_eventfd)) { 2154 ret = PTR_ERR(ffs->ffs_eventfd); 2155 ffs->ffs_eventfd = NULL; 2156 goto error; 2157 } 2158 data += 4; 2159 len -= 4; 2160 } 2161 2162 /* Read fs_count, hs_count and ss_count (if present) */ 2163 for (i = 0; i < 3; ++i) { 2164 if (!(flags & (1 << i))) { 2165 counts[i] = 0; 2166 } else if (len < 4) { 2167 goto error; 2168 } else { 2169 counts[i] = get_unaligned_le32(data); 2170 data += 4; 2171 len -= 4; 2172 } 2173 } 2174 if (flags & (1 << i)) { 2175 os_descs_count = get_unaligned_le32(data); 2176 data += 4; 2177 len -= 4; 2178 }; 2179 2180 /* Read descriptors */ 2181 raw_descs = data; 2182 helper.ffs = ffs; 2183 for (i = 0; i < 3; ++i) { 2184 if (!counts[i]) 2185 continue; 2186 helper.interfaces_count = 0; 2187 helper.eps_count = 0; 2188 ret = ffs_do_descs(counts[i], data, len, 2189 __ffs_data_do_entity, &helper); 2190 if (ret < 0) 2191 goto error; 2192 if (!ffs->eps_count && !ffs->interfaces_count) { 2193 ffs->eps_count = helper.eps_count; 2194 ffs->interfaces_count = helper.interfaces_count; 2195 } else { 2196 if (ffs->eps_count != helper.eps_count) { 2197 ret = -EINVAL; 2198 goto error; 2199 } 2200 if (ffs->interfaces_count != helper.interfaces_count) { 2201 ret = -EINVAL; 2202 goto error; 2203 } 2204 } 2205 data += ret; 2206 len -= ret; 2207 } 2208 if (os_descs_count) { 2209 ret = ffs_do_os_descs(os_descs_count, data, len, 2210 __ffs_data_do_os_desc, ffs); 2211 if (ret < 0) 2212 goto error; 2213 data += ret; 2214 len -= ret; 2215 } 2216 2217 if (raw_descs == data || len) { 2218 ret = -EINVAL; 2219 goto error; 2220 } 2221 2222 ffs->raw_descs_data = _data; 2223 ffs->raw_descs = raw_descs; 2224 ffs->raw_descs_length = data - raw_descs; 2225 ffs->fs_descs_count = counts[0]; 2226 ffs->hs_descs_count = counts[1]; 2227 ffs->ss_descs_count = counts[2]; 2228 ffs->ms_os_descs_count = os_descs_count; 2229 2230 return 0; 2231 2232 error: 2233 kfree(_data); 2234 return ret; 2235 } 2236 2237 static int __ffs_data_got_strings(struct ffs_data *ffs, 2238 char *const _data, size_t len) 2239 { 2240 u32 str_count, needed_count, lang_count; 2241 struct usb_gadget_strings **stringtabs, *t; 2242 struct usb_string *strings, *s; 2243 const char *data = _data; 2244 2245 ENTER(); 2246 2247 if (unlikely(get_unaligned_le32(data) != FUNCTIONFS_STRINGS_MAGIC || 2248 get_unaligned_le32(data + 4) != len)) 2249 goto error; 2250 str_count = get_unaligned_le32(data + 8); 2251 lang_count = get_unaligned_le32(data + 12); 2252 2253 /* if one is zero the other must be zero */ 2254 if (unlikely(!str_count != !lang_count)) 2255 goto error; 2256 2257 /* Do we have at least as many strings as descriptors need? */ 2258 needed_count = ffs->strings_count; 2259 if (unlikely(str_count < needed_count)) 2260 goto error; 2261 2262 /* 2263 * If we don't need any strings just return and free all 2264 * memory. 2265 */ 2266 if (!needed_count) { 2267 kfree(_data); 2268 return 0; 2269 } 2270 2271 /* Allocate everything in one chunk so there's less maintenance. */ 2272 { 2273 unsigned i = 0; 2274 vla_group(d); 2275 vla_item(d, struct usb_gadget_strings *, stringtabs, 2276 lang_count + 1); 2277 vla_item(d, struct usb_gadget_strings, stringtab, lang_count); 2278 vla_item(d, struct usb_string, strings, 2279 lang_count*(needed_count+1)); 2280 2281 char *vlabuf = kmalloc(vla_group_size(d), GFP_KERNEL); 2282 2283 if (unlikely(!vlabuf)) { 2284 kfree(_data); 2285 return -ENOMEM; 2286 } 2287 2288 /* Initialize the VLA pointers */ 2289 stringtabs = vla_ptr(vlabuf, d, stringtabs); 2290 t = vla_ptr(vlabuf, d, stringtab); 2291 i = lang_count; 2292 do { 2293 *stringtabs++ = t++; 2294 } while (--i); 2295 *stringtabs = NULL; 2296 2297 /* stringtabs = vlabuf = d_stringtabs for later kfree */ 2298 stringtabs = vla_ptr(vlabuf, d, stringtabs); 2299 t = vla_ptr(vlabuf, d, stringtab); 2300 s = vla_ptr(vlabuf, d, strings); 2301 strings = s; 2302 } 2303 2304 /* For each language */ 2305 data += 16; 2306 len -= 16; 2307 2308 do { /* lang_count > 0 so we can use do-while */ 2309 unsigned needed = needed_count; 2310 2311 if (unlikely(len < 3)) 2312 goto error_free; 2313 t->language = get_unaligned_le16(data); 2314 t->strings = s; 2315 ++t; 2316 2317 data += 2; 2318 len -= 2; 2319 2320 /* For each string */ 2321 do { /* str_count > 0 so we can use do-while */ 2322 size_t length = strnlen(data, len); 2323 2324 if (unlikely(length == len)) 2325 goto error_free; 2326 2327 /* 2328 * User may provide more strings then we need, 2329 * if that's the case we simply ignore the 2330 * rest 2331 */ 2332 if (likely(needed)) { 2333 /* 2334 * s->id will be set while adding 2335 * function to configuration so for 2336 * now just leave garbage here. 2337 */ 2338 s->s = data; 2339 --needed; 2340 ++s; 2341 } 2342 2343 data += length + 1; 2344 len -= length + 1; 2345 } while (--str_count); 2346 2347 s->id = 0; /* terminator */ 2348 s->s = NULL; 2349 ++s; 2350 2351 } while (--lang_count); 2352 2353 /* Some garbage left? */ 2354 if (unlikely(len)) 2355 goto error_free; 2356 2357 /* Done! */ 2358 ffs->stringtabs = stringtabs; 2359 ffs->raw_strings = _data; 2360 2361 return 0; 2362 2363 error_free: 2364 kfree(stringtabs); 2365 error: 2366 kfree(_data); 2367 return -EINVAL; 2368 } 2369 2370 2371 /* Events handling and management *******************************************/ 2372 2373 static void __ffs_event_add(struct ffs_data *ffs, 2374 enum usb_functionfs_event_type type) 2375 { 2376 enum usb_functionfs_event_type rem_type1, rem_type2 = type; 2377 int neg = 0; 2378 2379 /* 2380 * Abort any unhandled setup 2381 * 2382 * We do not need to worry about some cmpxchg() changing value 2383 * of ffs->setup_state without holding the lock because when 2384 * state is FFS_SETUP_PENDING cmpxchg() in several places in 2385 * the source does nothing. 2386 */ 2387 if (ffs->setup_state == FFS_SETUP_PENDING) 2388 ffs->setup_state = FFS_SETUP_CANCELLED; 2389 2390 /* 2391 * Logic of this function guarantees that there are at most four pending 2392 * evens on ffs->ev.types queue. This is important because the queue 2393 * has space for four elements only and __ffs_ep0_read_events function 2394 * depends on that limit as well. If more event types are added, those 2395 * limits have to be revisited or guaranteed to still hold. 2396 */ 2397 switch (type) { 2398 case FUNCTIONFS_RESUME: 2399 rem_type2 = FUNCTIONFS_SUSPEND; 2400 /* FALL THROUGH */ 2401 case FUNCTIONFS_SUSPEND: 2402 case FUNCTIONFS_SETUP: 2403 rem_type1 = type; 2404 /* Discard all similar events */ 2405 break; 2406 2407 case FUNCTIONFS_BIND: 2408 case FUNCTIONFS_UNBIND: 2409 case FUNCTIONFS_DISABLE: 2410 case FUNCTIONFS_ENABLE: 2411 /* Discard everything other then power management. */ 2412 rem_type1 = FUNCTIONFS_SUSPEND; 2413 rem_type2 = FUNCTIONFS_RESUME; 2414 neg = 1; 2415 break; 2416 2417 default: 2418 WARN(1, "%d: unknown event, this should not happen\n", type); 2419 return; 2420 } 2421 2422 { 2423 u8 *ev = ffs->ev.types, *out = ev; 2424 unsigned n = ffs->ev.count; 2425 for (; n; --n, ++ev) 2426 if ((*ev == rem_type1 || *ev == rem_type2) == neg) 2427 *out++ = *ev; 2428 else 2429 pr_vdebug("purging event %d\n", *ev); 2430 ffs->ev.count = out - ffs->ev.types; 2431 } 2432 2433 pr_vdebug("adding event %d\n", type); 2434 ffs->ev.types[ffs->ev.count++] = type; 2435 wake_up_locked(&ffs->ev.waitq); 2436 if (ffs->ffs_eventfd) 2437 eventfd_signal(ffs->ffs_eventfd, 1); 2438 } 2439 2440 static void ffs_event_add(struct ffs_data *ffs, 2441 enum usb_functionfs_event_type type) 2442 { 2443 unsigned long flags; 2444 spin_lock_irqsave(&ffs->ev.waitq.lock, flags); 2445 __ffs_event_add(ffs, type); 2446 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags); 2447 } 2448 2449 /* Bind/unbind USB function hooks *******************************************/ 2450 2451 static int ffs_ep_addr2idx(struct ffs_data *ffs, u8 endpoint_address) 2452 { 2453 int i; 2454 2455 for (i = 1; i < ARRAY_SIZE(ffs->eps_addrmap); ++i) 2456 if (ffs->eps_addrmap[i] == endpoint_address) 2457 return i; 2458 return -ENOENT; 2459 } 2460 2461 static int __ffs_func_bind_do_descs(enum ffs_entity_type type, u8 *valuep, 2462 struct usb_descriptor_header *desc, 2463 void *priv) 2464 { 2465 struct usb_endpoint_descriptor *ds = (void *)desc; 2466 struct ffs_function *func = priv; 2467 struct ffs_ep *ffs_ep; 2468 unsigned ep_desc_id; 2469 int idx; 2470 static const char *speed_names[] = { "full", "high", "super" }; 2471 2472 if (type != FFS_DESCRIPTOR) 2473 return 0; 2474 2475 /* 2476 * If ss_descriptors is not NULL, we are reading super speed 2477 * descriptors; if hs_descriptors is not NULL, we are reading high 2478 * speed descriptors; otherwise, we are reading full speed 2479 * descriptors. 2480 */ 2481 if (func->function.ss_descriptors) { 2482 ep_desc_id = 2; 2483 func->function.ss_descriptors[(long)valuep] = desc; 2484 } else if (func->function.hs_descriptors) { 2485 ep_desc_id = 1; 2486 func->function.hs_descriptors[(long)valuep] = desc; 2487 } else { 2488 ep_desc_id = 0; 2489 func->function.fs_descriptors[(long)valuep] = desc; 2490 } 2491 2492 if (!desc || desc->bDescriptorType != USB_DT_ENDPOINT) 2493 return 0; 2494 2495 idx = ffs_ep_addr2idx(func->ffs, ds->bEndpointAddress) - 1; 2496 if (idx < 0) 2497 return idx; 2498 2499 ffs_ep = func->eps + idx; 2500 2501 if (unlikely(ffs_ep->descs[ep_desc_id])) { 2502 pr_err("two %sspeed descriptors for EP %d\n", 2503 speed_names[ep_desc_id], 2504 ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK); 2505 return -EINVAL; 2506 } 2507 ffs_ep->descs[ep_desc_id] = ds; 2508 2509 ffs_dump_mem(": Original ep desc", ds, ds->bLength); 2510 if (ffs_ep->ep) { 2511 ds->bEndpointAddress = ffs_ep->descs[0]->bEndpointAddress; 2512 if (!ds->wMaxPacketSize) 2513 ds->wMaxPacketSize = ffs_ep->descs[0]->wMaxPacketSize; 2514 } else { 2515 struct usb_request *req; 2516 struct usb_ep *ep; 2517 u8 bEndpointAddress; 2518 2519 /* 2520 * We back up bEndpointAddress because autoconfig overwrites 2521 * it with physical endpoint address. 2522 */ 2523 bEndpointAddress = ds->bEndpointAddress; 2524 pr_vdebug("autoconfig\n"); 2525 ep = usb_ep_autoconfig(func->gadget, ds); 2526 if (unlikely(!ep)) 2527 return -ENOTSUPP; 2528 ep->driver_data = func->eps + idx; 2529 2530 req = usb_ep_alloc_request(ep, GFP_KERNEL); 2531 if (unlikely(!req)) 2532 return -ENOMEM; 2533 2534 ffs_ep->ep = ep; 2535 ffs_ep->req = req; 2536 func->eps_revmap[ds->bEndpointAddress & 2537 USB_ENDPOINT_NUMBER_MASK] = idx + 1; 2538 /* 2539 * If we use virtual address mapping, we restore 2540 * original bEndpointAddress value. 2541 */ 2542 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR) 2543 ds->bEndpointAddress = bEndpointAddress; 2544 } 2545 ffs_dump_mem(": Rewritten ep desc", ds, ds->bLength); 2546 2547 return 0; 2548 } 2549 2550 static int __ffs_func_bind_do_nums(enum ffs_entity_type type, u8 *valuep, 2551 struct usb_descriptor_header *desc, 2552 void *priv) 2553 { 2554 struct ffs_function *func = priv; 2555 unsigned idx; 2556 u8 newValue; 2557 2558 switch (type) { 2559 default: 2560 case FFS_DESCRIPTOR: 2561 /* Handled in previous pass by __ffs_func_bind_do_descs() */ 2562 return 0; 2563 2564 case FFS_INTERFACE: 2565 idx = *valuep; 2566 if (func->interfaces_nums[idx] < 0) { 2567 int id = usb_interface_id(func->conf, &func->function); 2568 if (unlikely(id < 0)) 2569 return id; 2570 func->interfaces_nums[idx] = id; 2571 } 2572 newValue = func->interfaces_nums[idx]; 2573 break; 2574 2575 case FFS_STRING: 2576 /* String' IDs are allocated when fsf_data is bound to cdev */ 2577 newValue = func->ffs->stringtabs[0]->strings[*valuep - 1].id; 2578 break; 2579 2580 case FFS_ENDPOINT: 2581 /* 2582 * USB_DT_ENDPOINT are handled in 2583 * __ffs_func_bind_do_descs(). 2584 */ 2585 if (desc->bDescriptorType == USB_DT_ENDPOINT) 2586 return 0; 2587 2588 idx = (*valuep & USB_ENDPOINT_NUMBER_MASK) - 1; 2589 if (unlikely(!func->eps[idx].ep)) 2590 return -EINVAL; 2591 2592 { 2593 struct usb_endpoint_descriptor **descs; 2594 descs = func->eps[idx].descs; 2595 newValue = descs[descs[0] ? 0 : 1]->bEndpointAddress; 2596 } 2597 break; 2598 } 2599 2600 pr_vdebug("%02x -> %02x\n", *valuep, newValue); 2601 *valuep = newValue; 2602 return 0; 2603 } 2604 2605 static int __ffs_func_bind_do_os_desc(enum ffs_os_desc_type type, 2606 struct usb_os_desc_header *h, void *data, 2607 unsigned len, void *priv) 2608 { 2609 struct ffs_function *func = priv; 2610 u8 length = 0; 2611 2612 switch (type) { 2613 case FFS_OS_DESC_EXT_COMPAT: { 2614 struct usb_ext_compat_desc *desc = data; 2615 struct usb_os_desc_table *t; 2616 2617 t = &func->function.os_desc_table[desc->bFirstInterfaceNumber]; 2618 t->if_id = func->interfaces_nums[desc->bFirstInterfaceNumber]; 2619 memcpy(t->os_desc->ext_compat_id, &desc->CompatibleID, 2620 ARRAY_SIZE(desc->CompatibleID) + 2621 ARRAY_SIZE(desc->SubCompatibleID)); 2622 length = sizeof(*desc); 2623 } 2624 break; 2625 case FFS_OS_DESC_EXT_PROP: { 2626 struct usb_ext_prop_desc *desc = data; 2627 struct usb_os_desc_table *t; 2628 struct usb_os_desc_ext_prop *ext_prop; 2629 char *ext_prop_name; 2630 char *ext_prop_data; 2631 2632 t = &func->function.os_desc_table[h->interface]; 2633 t->if_id = func->interfaces_nums[h->interface]; 2634 2635 ext_prop = func->ffs->ms_os_descs_ext_prop_avail; 2636 func->ffs->ms_os_descs_ext_prop_avail += sizeof(*ext_prop); 2637 2638 ext_prop->type = le32_to_cpu(desc->dwPropertyDataType); 2639 ext_prop->name_len = le16_to_cpu(desc->wPropertyNameLength); 2640 ext_prop->data_len = le32_to_cpu(*(u32 *) 2641 usb_ext_prop_data_len_ptr(data, ext_prop->name_len)); 2642 length = ext_prop->name_len + ext_prop->data_len + 14; 2643 2644 ext_prop_name = func->ffs->ms_os_descs_ext_prop_name_avail; 2645 func->ffs->ms_os_descs_ext_prop_name_avail += 2646 ext_prop->name_len; 2647 2648 ext_prop_data = func->ffs->ms_os_descs_ext_prop_data_avail; 2649 func->ffs->ms_os_descs_ext_prop_data_avail += 2650 ext_prop->data_len; 2651 memcpy(ext_prop_data, 2652 usb_ext_prop_data_ptr(data, ext_prop->name_len), 2653 ext_prop->data_len); 2654 /* unicode data reported to the host as "WCHAR"s */ 2655 switch (ext_prop->type) { 2656 case USB_EXT_PROP_UNICODE: 2657 case USB_EXT_PROP_UNICODE_ENV: 2658 case USB_EXT_PROP_UNICODE_LINK: 2659 case USB_EXT_PROP_UNICODE_MULTI: 2660 ext_prop->data_len *= 2; 2661 break; 2662 } 2663 ext_prop->data = ext_prop_data; 2664 2665 memcpy(ext_prop_name, usb_ext_prop_name_ptr(data), 2666 ext_prop->name_len); 2667 /* property name reported to the host as "WCHAR"s */ 2668 ext_prop->name_len *= 2; 2669 ext_prop->name = ext_prop_name; 2670 2671 t->os_desc->ext_prop_len += 2672 ext_prop->name_len + ext_prop->data_len + 14; 2673 ++t->os_desc->ext_prop_count; 2674 list_add_tail(&ext_prop->entry, &t->os_desc->ext_prop); 2675 } 2676 break; 2677 default: 2678 pr_vdebug("unknown descriptor: %d\n", type); 2679 } 2680 2681 return length; 2682 } 2683 2684 static inline struct f_fs_opts *ffs_do_functionfs_bind(struct usb_function *f, 2685 struct usb_configuration *c) 2686 { 2687 struct ffs_function *func = ffs_func_from_usb(f); 2688 struct f_fs_opts *ffs_opts = 2689 container_of(f->fi, struct f_fs_opts, func_inst); 2690 int ret; 2691 2692 ENTER(); 2693 2694 /* 2695 * Legacy gadget triggers binding in functionfs_ready_callback, 2696 * which already uses locking; taking the same lock here would 2697 * cause a deadlock. 2698 * 2699 * Configfs-enabled gadgets however do need ffs_dev_lock. 2700 */ 2701 if (!ffs_opts->no_configfs) 2702 ffs_dev_lock(); 2703 ret = ffs_opts->dev->desc_ready ? 0 : -ENODEV; 2704 func->ffs = ffs_opts->dev->ffs_data; 2705 if (!ffs_opts->no_configfs) 2706 ffs_dev_unlock(); 2707 if (ret) 2708 return ERR_PTR(ret); 2709 2710 func->conf = c; 2711 func->gadget = c->cdev->gadget; 2712 2713 /* 2714 * in drivers/usb/gadget/configfs.c:configfs_composite_bind() 2715 * configurations are bound in sequence with list_for_each_entry, 2716 * in each configuration its functions are bound in sequence 2717 * with list_for_each_entry, so we assume no race condition 2718 * with regard to ffs_opts->bound access 2719 */ 2720 if (!ffs_opts->refcnt) { 2721 ret = functionfs_bind(func->ffs, c->cdev); 2722 if (ret) 2723 return ERR_PTR(ret); 2724 } 2725 ffs_opts->refcnt++; 2726 func->function.strings = func->ffs->stringtabs; 2727 2728 return ffs_opts; 2729 } 2730 2731 static int _ffs_func_bind(struct usb_configuration *c, 2732 struct usb_function *f) 2733 { 2734 struct ffs_function *func = ffs_func_from_usb(f); 2735 struct ffs_data *ffs = func->ffs; 2736 2737 const int full = !!func->ffs->fs_descs_count; 2738 const int high = gadget_is_dualspeed(func->gadget) && 2739 func->ffs->hs_descs_count; 2740 const int super = gadget_is_superspeed(func->gadget) && 2741 func->ffs->ss_descs_count; 2742 2743 int fs_len, hs_len, ss_len, ret, i; 2744 2745 /* Make it a single chunk, less management later on */ 2746 vla_group(d); 2747 vla_item_with_sz(d, struct ffs_ep, eps, ffs->eps_count); 2748 vla_item_with_sz(d, struct usb_descriptor_header *, fs_descs, 2749 full ? ffs->fs_descs_count + 1 : 0); 2750 vla_item_with_sz(d, struct usb_descriptor_header *, hs_descs, 2751 high ? ffs->hs_descs_count + 1 : 0); 2752 vla_item_with_sz(d, struct usb_descriptor_header *, ss_descs, 2753 super ? ffs->ss_descs_count + 1 : 0); 2754 vla_item_with_sz(d, short, inums, ffs->interfaces_count); 2755 vla_item_with_sz(d, struct usb_os_desc_table, os_desc_table, 2756 c->cdev->use_os_string ? ffs->interfaces_count : 0); 2757 vla_item_with_sz(d, char[16], ext_compat, 2758 c->cdev->use_os_string ? ffs->interfaces_count : 0); 2759 vla_item_with_sz(d, struct usb_os_desc, os_desc, 2760 c->cdev->use_os_string ? ffs->interfaces_count : 0); 2761 vla_item_with_sz(d, struct usb_os_desc_ext_prop, ext_prop, 2762 ffs->ms_os_descs_ext_prop_count); 2763 vla_item_with_sz(d, char, ext_prop_name, 2764 ffs->ms_os_descs_ext_prop_name_len); 2765 vla_item_with_sz(d, char, ext_prop_data, 2766 ffs->ms_os_descs_ext_prop_data_len); 2767 vla_item_with_sz(d, char, raw_descs, ffs->raw_descs_length); 2768 char *vlabuf; 2769 2770 ENTER(); 2771 2772 /* Has descriptors only for speeds gadget does not support */ 2773 if (unlikely(!(full | high | super))) 2774 return -ENOTSUPP; 2775 2776 /* Allocate a single chunk, less management later on */ 2777 vlabuf = kzalloc(vla_group_size(d), GFP_KERNEL); 2778 if (unlikely(!vlabuf)) 2779 return -ENOMEM; 2780 2781 ffs->ms_os_descs_ext_prop_avail = vla_ptr(vlabuf, d, ext_prop); 2782 ffs->ms_os_descs_ext_prop_name_avail = 2783 vla_ptr(vlabuf, d, ext_prop_name); 2784 ffs->ms_os_descs_ext_prop_data_avail = 2785 vla_ptr(vlabuf, d, ext_prop_data); 2786 2787 /* Copy descriptors */ 2788 memcpy(vla_ptr(vlabuf, d, raw_descs), ffs->raw_descs, 2789 ffs->raw_descs_length); 2790 2791 memset(vla_ptr(vlabuf, d, inums), 0xff, d_inums__sz); 2792 for (ret = ffs->eps_count; ret; --ret) { 2793 struct ffs_ep *ptr; 2794 2795 ptr = vla_ptr(vlabuf, d, eps); 2796 ptr[ret].num = -1; 2797 } 2798 2799 /* Save pointers 2800 * d_eps == vlabuf, func->eps used to kfree vlabuf later 2801 */ 2802 func->eps = vla_ptr(vlabuf, d, eps); 2803 func->interfaces_nums = vla_ptr(vlabuf, d, inums); 2804 2805 /* 2806 * Go through all the endpoint descriptors and allocate 2807 * endpoints first, so that later we can rewrite the endpoint 2808 * numbers without worrying that it may be described later on. 2809 */ 2810 if (likely(full)) { 2811 func->function.fs_descriptors = vla_ptr(vlabuf, d, fs_descs); 2812 fs_len = ffs_do_descs(ffs->fs_descs_count, 2813 vla_ptr(vlabuf, d, raw_descs), 2814 d_raw_descs__sz, 2815 __ffs_func_bind_do_descs, func); 2816 if (unlikely(fs_len < 0)) { 2817 ret = fs_len; 2818 goto error; 2819 } 2820 } else { 2821 fs_len = 0; 2822 } 2823 2824 if (likely(high)) { 2825 func->function.hs_descriptors = vla_ptr(vlabuf, d, hs_descs); 2826 hs_len = ffs_do_descs(ffs->hs_descs_count, 2827 vla_ptr(vlabuf, d, raw_descs) + fs_len, 2828 d_raw_descs__sz - fs_len, 2829 __ffs_func_bind_do_descs, func); 2830 if (unlikely(hs_len < 0)) { 2831 ret = hs_len; 2832 goto error; 2833 } 2834 } else { 2835 hs_len = 0; 2836 } 2837 2838 if (likely(super)) { 2839 func->function.ss_descriptors = vla_ptr(vlabuf, d, ss_descs); 2840 ss_len = ffs_do_descs(ffs->ss_descs_count, 2841 vla_ptr(vlabuf, d, raw_descs) + fs_len + hs_len, 2842 d_raw_descs__sz - fs_len - hs_len, 2843 __ffs_func_bind_do_descs, func); 2844 if (unlikely(ss_len < 0)) { 2845 ret = ss_len; 2846 goto error; 2847 } 2848 } else { 2849 ss_len = 0; 2850 } 2851 2852 /* 2853 * Now handle interface numbers allocation and interface and 2854 * endpoint numbers rewriting. We can do that in one go 2855 * now. 2856 */ 2857 ret = ffs_do_descs(ffs->fs_descs_count + 2858 (high ? ffs->hs_descs_count : 0) + 2859 (super ? ffs->ss_descs_count : 0), 2860 vla_ptr(vlabuf, d, raw_descs), d_raw_descs__sz, 2861 __ffs_func_bind_do_nums, func); 2862 if (unlikely(ret < 0)) 2863 goto error; 2864 2865 func->function.os_desc_table = vla_ptr(vlabuf, d, os_desc_table); 2866 if (c->cdev->use_os_string) 2867 for (i = 0; i < ffs->interfaces_count; ++i) { 2868 struct usb_os_desc *desc; 2869 2870 desc = func->function.os_desc_table[i].os_desc = 2871 vla_ptr(vlabuf, d, os_desc) + 2872 i * sizeof(struct usb_os_desc); 2873 desc->ext_compat_id = 2874 vla_ptr(vlabuf, d, ext_compat) + i * 16; 2875 INIT_LIST_HEAD(&desc->ext_prop); 2876 } 2877 ret = ffs_do_os_descs(ffs->ms_os_descs_count, 2878 vla_ptr(vlabuf, d, raw_descs) + 2879 fs_len + hs_len + ss_len, 2880 d_raw_descs__sz - fs_len - hs_len - ss_len, 2881 __ffs_func_bind_do_os_desc, func); 2882 if (unlikely(ret < 0)) 2883 goto error; 2884 func->function.os_desc_n = 2885 c->cdev->use_os_string ? ffs->interfaces_count : 0; 2886 2887 /* And we're done */ 2888 ffs_event_add(ffs, FUNCTIONFS_BIND); 2889 return 0; 2890 2891 error: 2892 /* XXX Do we need to release all claimed endpoints here? */ 2893 return ret; 2894 } 2895 2896 static int ffs_func_bind(struct usb_configuration *c, 2897 struct usb_function *f) 2898 { 2899 struct f_fs_opts *ffs_opts = ffs_do_functionfs_bind(f, c); 2900 struct ffs_function *func = ffs_func_from_usb(f); 2901 int ret; 2902 2903 if (IS_ERR(ffs_opts)) 2904 return PTR_ERR(ffs_opts); 2905 2906 ret = _ffs_func_bind(c, f); 2907 if (ret && !--ffs_opts->refcnt) 2908 functionfs_unbind(func->ffs); 2909 2910 return ret; 2911 } 2912 2913 2914 /* Other USB function hooks *************************************************/ 2915 2916 static void ffs_reset_work(struct work_struct *work) 2917 { 2918 struct ffs_data *ffs = container_of(work, 2919 struct ffs_data, reset_work); 2920 ffs_data_reset(ffs); 2921 } 2922 2923 static int ffs_func_set_alt(struct usb_function *f, 2924 unsigned interface, unsigned alt) 2925 { 2926 struct ffs_function *func = ffs_func_from_usb(f); 2927 struct ffs_data *ffs = func->ffs; 2928 int ret = 0, intf; 2929 2930 if (alt != (unsigned)-1) { 2931 intf = ffs_func_revmap_intf(func, interface); 2932 if (unlikely(intf < 0)) 2933 return intf; 2934 } 2935 2936 if (ffs->func) 2937 ffs_func_eps_disable(ffs->func); 2938 2939 if (ffs->state == FFS_DEACTIVATED) { 2940 ffs->state = FFS_CLOSING; 2941 INIT_WORK(&ffs->reset_work, ffs_reset_work); 2942 schedule_work(&ffs->reset_work); 2943 return -ENODEV; 2944 } 2945 2946 if (ffs->state != FFS_ACTIVE) 2947 return -ENODEV; 2948 2949 if (alt == (unsigned)-1) { 2950 ffs->func = NULL; 2951 ffs_event_add(ffs, FUNCTIONFS_DISABLE); 2952 return 0; 2953 } 2954 2955 ffs->func = func; 2956 ret = ffs_func_eps_enable(func); 2957 if (likely(ret >= 0)) 2958 ffs_event_add(ffs, FUNCTIONFS_ENABLE); 2959 return ret; 2960 } 2961 2962 static void ffs_func_disable(struct usb_function *f) 2963 { 2964 ffs_func_set_alt(f, 0, (unsigned)-1); 2965 } 2966 2967 static int ffs_func_setup(struct usb_function *f, 2968 const struct usb_ctrlrequest *creq) 2969 { 2970 struct ffs_function *func = ffs_func_from_usb(f); 2971 struct ffs_data *ffs = func->ffs; 2972 unsigned long flags; 2973 int ret; 2974 2975 ENTER(); 2976 2977 pr_vdebug("creq->bRequestType = %02x\n", creq->bRequestType); 2978 pr_vdebug("creq->bRequest = %02x\n", creq->bRequest); 2979 pr_vdebug("creq->wValue = %04x\n", le16_to_cpu(creq->wValue)); 2980 pr_vdebug("creq->wIndex = %04x\n", le16_to_cpu(creq->wIndex)); 2981 pr_vdebug("creq->wLength = %04x\n", le16_to_cpu(creq->wLength)); 2982 2983 /* 2984 * Most requests directed to interface go through here 2985 * (notable exceptions are set/get interface) so we need to 2986 * handle them. All other either handled by composite or 2987 * passed to usb_configuration->setup() (if one is set). No 2988 * matter, we will handle requests directed to endpoint here 2989 * as well (as it's straightforward) but what to do with any 2990 * other request? 2991 */ 2992 if (ffs->state != FFS_ACTIVE) 2993 return -ENODEV; 2994 2995 switch (creq->bRequestType & USB_RECIP_MASK) { 2996 case USB_RECIP_INTERFACE: 2997 ret = ffs_func_revmap_intf(func, le16_to_cpu(creq->wIndex)); 2998 if (unlikely(ret < 0)) 2999 return ret; 3000 break; 3001 3002 case USB_RECIP_ENDPOINT: 3003 ret = ffs_func_revmap_ep(func, le16_to_cpu(creq->wIndex)); 3004 if (unlikely(ret < 0)) 3005 return ret; 3006 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR) 3007 ret = func->ffs->eps_addrmap[ret]; 3008 break; 3009 3010 default: 3011 return -EOPNOTSUPP; 3012 } 3013 3014 spin_lock_irqsave(&ffs->ev.waitq.lock, flags); 3015 ffs->ev.setup = *creq; 3016 ffs->ev.setup.wIndex = cpu_to_le16(ret); 3017 __ffs_event_add(ffs, FUNCTIONFS_SETUP); 3018 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags); 3019 3020 return 0; 3021 } 3022 3023 static void ffs_func_suspend(struct usb_function *f) 3024 { 3025 ENTER(); 3026 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_SUSPEND); 3027 } 3028 3029 static void ffs_func_resume(struct usb_function *f) 3030 { 3031 ENTER(); 3032 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_RESUME); 3033 } 3034 3035 3036 /* Endpoint and interface numbers reverse mapping ***************************/ 3037 3038 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num) 3039 { 3040 num = func->eps_revmap[num & USB_ENDPOINT_NUMBER_MASK]; 3041 return num ? num : -EDOM; 3042 } 3043 3044 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf) 3045 { 3046 short *nums = func->interfaces_nums; 3047 unsigned count = func->ffs->interfaces_count; 3048 3049 for (; count; --count, ++nums) { 3050 if (*nums >= 0 && *nums == intf) 3051 return nums - func->interfaces_nums; 3052 } 3053 3054 return -EDOM; 3055 } 3056 3057 3058 /* Devices management *******************************************************/ 3059 3060 static LIST_HEAD(ffs_devices); 3061 3062 static struct ffs_dev *_ffs_do_find_dev(const char *name) 3063 { 3064 struct ffs_dev *dev; 3065 3066 list_for_each_entry(dev, &ffs_devices, entry) { 3067 if (!dev->name || !name) 3068 continue; 3069 if (strcmp(dev->name, name) == 0) 3070 return dev; 3071 } 3072 3073 return NULL; 3074 } 3075 3076 /* 3077 * ffs_lock must be taken by the caller of this function 3078 */ 3079 static struct ffs_dev *_ffs_get_single_dev(void) 3080 { 3081 struct ffs_dev *dev; 3082 3083 if (list_is_singular(&ffs_devices)) { 3084 dev = list_first_entry(&ffs_devices, struct ffs_dev, entry); 3085 if (dev->single) 3086 return dev; 3087 } 3088 3089 return NULL; 3090 } 3091 3092 /* 3093 * ffs_lock must be taken by the caller of this function 3094 */ 3095 static struct ffs_dev *_ffs_find_dev(const char *name) 3096 { 3097 struct ffs_dev *dev; 3098 3099 dev = _ffs_get_single_dev(); 3100 if (dev) 3101 return dev; 3102 3103 return _ffs_do_find_dev(name); 3104 } 3105 3106 /* Configfs support *********************************************************/ 3107 3108 static inline struct f_fs_opts *to_ffs_opts(struct config_item *item) 3109 { 3110 return container_of(to_config_group(item), struct f_fs_opts, 3111 func_inst.group); 3112 } 3113 3114 static void ffs_attr_release(struct config_item *item) 3115 { 3116 struct f_fs_opts *opts = to_ffs_opts(item); 3117 3118 usb_put_function_instance(&opts->func_inst); 3119 } 3120 3121 static struct configfs_item_operations ffs_item_ops = { 3122 .release = ffs_attr_release, 3123 }; 3124 3125 static struct config_item_type ffs_func_type = { 3126 .ct_item_ops = &ffs_item_ops, 3127 .ct_owner = THIS_MODULE, 3128 }; 3129 3130 3131 /* Function registration interface ******************************************/ 3132 3133 static void ffs_free_inst(struct usb_function_instance *f) 3134 { 3135 struct f_fs_opts *opts; 3136 3137 opts = to_f_fs_opts(f); 3138 ffs_dev_lock(); 3139 _ffs_free_dev(opts->dev); 3140 ffs_dev_unlock(); 3141 kfree(opts); 3142 } 3143 3144 #define MAX_INST_NAME_LEN 40 3145 3146 static int ffs_set_inst_name(struct usb_function_instance *fi, const char *name) 3147 { 3148 struct f_fs_opts *opts; 3149 char *ptr; 3150 const char *tmp; 3151 int name_len, ret; 3152 3153 name_len = strlen(name) + 1; 3154 if (name_len > MAX_INST_NAME_LEN) 3155 return -ENAMETOOLONG; 3156 3157 ptr = kstrndup(name, name_len, GFP_KERNEL); 3158 if (!ptr) 3159 return -ENOMEM; 3160 3161 opts = to_f_fs_opts(fi); 3162 tmp = NULL; 3163 3164 ffs_dev_lock(); 3165 3166 tmp = opts->dev->name_allocated ? opts->dev->name : NULL; 3167 ret = _ffs_name_dev(opts->dev, ptr); 3168 if (ret) { 3169 kfree(ptr); 3170 ffs_dev_unlock(); 3171 return ret; 3172 } 3173 opts->dev->name_allocated = true; 3174 3175 ffs_dev_unlock(); 3176 3177 kfree(tmp); 3178 3179 return 0; 3180 } 3181 3182 static struct usb_function_instance *ffs_alloc_inst(void) 3183 { 3184 struct f_fs_opts *opts; 3185 struct ffs_dev *dev; 3186 3187 opts = kzalloc(sizeof(*opts), GFP_KERNEL); 3188 if (!opts) 3189 return ERR_PTR(-ENOMEM); 3190 3191 opts->func_inst.set_inst_name = ffs_set_inst_name; 3192 opts->func_inst.free_func_inst = ffs_free_inst; 3193 ffs_dev_lock(); 3194 dev = _ffs_alloc_dev(); 3195 ffs_dev_unlock(); 3196 if (IS_ERR(dev)) { 3197 kfree(opts); 3198 return ERR_CAST(dev); 3199 } 3200 opts->dev = dev; 3201 dev->opts = opts; 3202 3203 config_group_init_type_name(&opts->func_inst.group, "", 3204 &ffs_func_type); 3205 return &opts->func_inst; 3206 } 3207 3208 static void ffs_free(struct usb_function *f) 3209 { 3210 kfree(ffs_func_from_usb(f)); 3211 } 3212 3213 static void ffs_func_unbind(struct usb_configuration *c, 3214 struct usb_function *f) 3215 { 3216 struct ffs_function *func = ffs_func_from_usb(f); 3217 struct ffs_data *ffs = func->ffs; 3218 struct f_fs_opts *opts = 3219 container_of(f->fi, struct f_fs_opts, func_inst); 3220 struct ffs_ep *ep = func->eps; 3221 unsigned count = ffs->eps_count; 3222 unsigned long flags; 3223 3224 ENTER(); 3225 if (ffs->func == func) { 3226 ffs_func_eps_disable(func); 3227 ffs->func = NULL; 3228 } 3229 3230 if (!--opts->refcnt) 3231 functionfs_unbind(ffs); 3232 3233 /* cleanup after autoconfig */ 3234 spin_lock_irqsave(&func->ffs->eps_lock, flags); 3235 do { 3236 if (ep->ep && ep->req) 3237 usb_ep_free_request(ep->ep, ep->req); 3238 ep->req = NULL; 3239 ++ep; 3240 } while (--count); 3241 spin_unlock_irqrestore(&func->ffs->eps_lock, flags); 3242 kfree(func->eps); 3243 func->eps = NULL; 3244 /* 3245 * eps, descriptors and interfaces_nums are allocated in the 3246 * same chunk so only one free is required. 3247 */ 3248 func->function.fs_descriptors = NULL; 3249 func->function.hs_descriptors = NULL; 3250 func->function.ss_descriptors = NULL; 3251 func->interfaces_nums = NULL; 3252 3253 ffs_event_add(ffs, FUNCTIONFS_UNBIND); 3254 } 3255 3256 static struct usb_function *ffs_alloc(struct usb_function_instance *fi) 3257 { 3258 struct ffs_function *func; 3259 3260 ENTER(); 3261 3262 func = kzalloc(sizeof(*func), GFP_KERNEL); 3263 if (unlikely(!func)) 3264 return ERR_PTR(-ENOMEM); 3265 3266 func->function.name = "Function FS Gadget"; 3267 3268 func->function.bind = ffs_func_bind; 3269 func->function.unbind = ffs_func_unbind; 3270 func->function.set_alt = ffs_func_set_alt; 3271 func->function.disable = ffs_func_disable; 3272 func->function.setup = ffs_func_setup; 3273 func->function.suspend = ffs_func_suspend; 3274 func->function.resume = ffs_func_resume; 3275 func->function.free_func = ffs_free; 3276 3277 return &func->function; 3278 } 3279 3280 /* 3281 * ffs_lock must be taken by the caller of this function 3282 */ 3283 static struct ffs_dev *_ffs_alloc_dev(void) 3284 { 3285 struct ffs_dev *dev; 3286 int ret; 3287 3288 if (_ffs_get_single_dev()) 3289 return ERR_PTR(-EBUSY); 3290 3291 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 3292 if (!dev) 3293 return ERR_PTR(-ENOMEM); 3294 3295 if (list_empty(&ffs_devices)) { 3296 ret = functionfs_init(); 3297 if (ret) { 3298 kfree(dev); 3299 return ERR_PTR(ret); 3300 } 3301 } 3302 3303 list_add(&dev->entry, &ffs_devices); 3304 3305 return dev; 3306 } 3307 3308 /* 3309 * ffs_lock must be taken by the caller of this function 3310 * The caller is responsible for "name" being available whenever f_fs needs it 3311 */ 3312 static int _ffs_name_dev(struct ffs_dev *dev, const char *name) 3313 { 3314 struct ffs_dev *existing; 3315 3316 existing = _ffs_do_find_dev(name); 3317 if (existing) 3318 return -EBUSY; 3319 3320 dev->name = name; 3321 3322 return 0; 3323 } 3324 3325 /* 3326 * The caller is responsible for "name" being available whenever f_fs needs it 3327 */ 3328 int ffs_name_dev(struct ffs_dev *dev, const char *name) 3329 { 3330 int ret; 3331 3332 ffs_dev_lock(); 3333 ret = _ffs_name_dev(dev, name); 3334 ffs_dev_unlock(); 3335 3336 return ret; 3337 } 3338 EXPORT_SYMBOL_GPL(ffs_name_dev); 3339 3340 int ffs_single_dev(struct ffs_dev *dev) 3341 { 3342 int ret; 3343 3344 ret = 0; 3345 ffs_dev_lock(); 3346 3347 if (!list_is_singular(&ffs_devices)) 3348 ret = -EBUSY; 3349 else 3350 dev->single = true; 3351 3352 ffs_dev_unlock(); 3353 return ret; 3354 } 3355 EXPORT_SYMBOL_GPL(ffs_single_dev); 3356 3357 /* 3358 * ffs_lock must be taken by the caller of this function 3359 */ 3360 static void _ffs_free_dev(struct ffs_dev *dev) 3361 { 3362 list_del(&dev->entry); 3363 if (dev->name_allocated) 3364 kfree(dev->name); 3365 kfree(dev); 3366 if (list_empty(&ffs_devices)) 3367 functionfs_cleanup(); 3368 } 3369 3370 static void *ffs_acquire_dev(const char *dev_name) 3371 { 3372 struct ffs_dev *ffs_dev; 3373 3374 ENTER(); 3375 ffs_dev_lock(); 3376 3377 ffs_dev = _ffs_find_dev(dev_name); 3378 if (!ffs_dev) 3379 ffs_dev = ERR_PTR(-ENOENT); 3380 else if (ffs_dev->mounted) 3381 ffs_dev = ERR_PTR(-EBUSY); 3382 else if (ffs_dev->ffs_acquire_dev_callback && 3383 ffs_dev->ffs_acquire_dev_callback(ffs_dev)) 3384 ffs_dev = ERR_PTR(-ENOENT); 3385 else 3386 ffs_dev->mounted = true; 3387 3388 ffs_dev_unlock(); 3389 return ffs_dev; 3390 } 3391 3392 static void ffs_release_dev(struct ffs_data *ffs_data) 3393 { 3394 struct ffs_dev *ffs_dev; 3395 3396 ENTER(); 3397 ffs_dev_lock(); 3398 3399 ffs_dev = ffs_data->private_data; 3400 if (ffs_dev) { 3401 ffs_dev->mounted = false; 3402 3403 if (ffs_dev->ffs_release_dev_callback) 3404 ffs_dev->ffs_release_dev_callback(ffs_dev); 3405 } 3406 3407 ffs_dev_unlock(); 3408 } 3409 3410 static int ffs_ready(struct ffs_data *ffs) 3411 { 3412 struct ffs_dev *ffs_obj; 3413 int ret = 0; 3414 3415 ENTER(); 3416 ffs_dev_lock(); 3417 3418 ffs_obj = ffs->private_data; 3419 if (!ffs_obj) { 3420 ret = -EINVAL; 3421 goto done; 3422 } 3423 if (WARN_ON(ffs_obj->desc_ready)) { 3424 ret = -EBUSY; 3425 goto done; 3426 } 3427 3428 ffs_obj->desc_ready = true; 3429 ffs_obj->ffs_data = ffs; 3430 3431 if (ffs_obj->ffs_ready_callback) { 3432 ret = ffs_obj->ffs_ready_callback(ffs); 3433 if (ret) 3434 goto done; 3435 } 3436 3437 set_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags); 3438 done: 3439 ffs_dev_unlock(); 3440 return ret; 3441 } 3442 3443 static void ffs_closed(struct ffs_data *ffs) 3444 { 3445 struct ffs_dev *ffs_obj; 3446 struct f_fs_opts *opts; 3447 3448 ENTER(); 3449 ffs_dev_lock(); 3450 3451 ffs_obj = ffs->private_data; 3452 if (!ffs_obj) 3453 goto done; 3454 3455 ffs_obj->desc_ready = false; 3456 3457 if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags) && 3458 ffs_obj->ffs_closed_callback) 3459 ffs_obj->ffs_closed_callback(ffs); 3460 3461 if (ffs_obj->opts) 3462 opts = ffs_obj->opts; 3463 else 3464 goto done; 3465 3466 if (opts->no_configfs || !opts->func_inst.group.cg_item.ci_parent 3467 || !atomic_read(&opts->func_inst.group.cg_item.ci_kref.refcount)) 3468 goto done; 3469 3470 unregister_gadget_item(ffs_obj->opts-> 3471 func_inst.group.cg_item.ci_parent->ci_parent); 3472 done: 3473 ffs_dev_unlock(); 3474 } 3475 3476 /* Misc helper functions ****************************************************/ 3477 3478 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock) 3479 { 3480 return nonblock 3481 ? likely(mutex_trylock(mutex)) ? 0 : -EAGAIN 3482 : mutex_lock_interruptible(mutex); 3483 } 3484 3485 static char *ffs_prepare_buffer(const char __user *buf, size_t len) 3486 { 3487 char *data; 3488 3489 if (unlikely(!len)) 3490 return NULL; 3491 3492 data = kmalloc(len, GFP_KERNEL); 3493 if (unlikely(!data)) 3494 return ERR_PTR(-ENOMEM); 3495 3496 if (unlikely(__copy_from_user(data, buf, len))) { 3497 kfree(data); 3498 return ERR_PTR(-EFAULT); 3499 } 3500 3501 pr_vdebug("Buffer from user space:\n"); 3502 ffs_dump_mem("", data, len); 3503 3504 return data; 3505 } 3506 3507 DECLARE_USB_FUNCTION_INIT(ffs, ffs_alloc_inst, ffs_alloc); 3508 MODULE_LICENSE("GPL"); 3509 MODULE_AUTHOR("Michal Nazarewicz"); 3510