1 /* -*- Mode: C; indent-tabs-mode:t ; c-basic-offset:8 -*- */ 2 /* 3 * Core functions for libusbx 4 * Copyright 2012-2013 Nathan Hjelm <hjelmn (at) cs.unm.edu> 5 * Copyright 2007-2008 Daniel Drake <dsd (at) gentoo.org> 6 * Copyright 2001 Johannes Erdfelt <johannes (at) erdfelt.com> 7 * 8 * This library is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU Lesser General Public 10 * License as published by the Free Software Foundation; either 11 * version 2.1 of the License, or (at your option) any later version. 12 * 13 * This library is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 16 * Lesser General Public License for more details. 17 * 18 * You should have received a copy of the GNU Lesser General Public 19 * License along with this library; if not, write to the Free Software 20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 21 */ 22 23 #include "config.h" 24 25 #include <errno.h> 26 #include <stdarg.h> 27 #include <stdio.h> 28 #include <stdlib.h> 29 #include <string.h> 30 #ifdef HAVE_SYS_TYPES_H 31 #include <sys/types.h> 32 #endif 33 #ifdef HAVE_SYS_TIME_H 34 #include <sys/time.h> 35 #endif 36 #ifdef HAVE_SYSLOG_H 37 #include <syslog.h> 38 #endif 39 40 #ifdef __ANDROID__ 41 #include <android/log.h> 42 #endif 43 44 #include "libusbi.h" 45 #include "hotplug.h" 46 47 #if defined(OS_LINUX) 48 const struct usbi_os_backend * const usbi_backend = &linux_usbfs_backend; 49 #elif defined(OS_DARWIN) 50 const struct usbi_os_backend * const usbi_backend = &darwin_backend; 51 #elif defined(OS_OPENBSD) 52 const struct usbi_os_backend * const usbi_backend = &openbsd_backend; 53 #elif defined(OS_NETBSD) 54 const struct usbi_os_backend * const usbi_backend = &netbsd_backend; 55 #elif defined(OS_WINDOWS) 56 const struct usbi_os_backend * const usbi_backend = &windows_backend; 57 #elif defined(OS_WINCE) 58 const struct usbi_os_backend * const usbi_backend = &wince_backend; 59 #else 60 #error "Unsupported OS" 61 #endif 62 63 struct libusb_context *usbi_default_context = NULL; 64 static const struct libusb_version libusb_version_internal = 65 { LIBUSB_MAJOR, LIBUSB_MINOR, LIBUSB_MICRO, LIBUSB_NANO, 66 LIBUSB_RC, "http://libusbx.org" }; 67 static int default_context_refcnt = 0; 68 static usbi_mutex_static_t default_context_lock = USBI_MUTEX_INITIALIZER; 69 static struct timeval timestamp_origin = { 0, 0 }; 70 71 usbi_mutex_static_t active_contexts_lock = USBI_MUTEX_INITIALIZER; 72 struct list_head active_contexts_list; 73 74 /** 75 * \mainpage libusbx-1.0 API Reference 76 * 77 * \section intro Introduction 78 * 79 * libusbx is an open source library that allows you to communicate with USB 80 * devices from userspace. For more info, see the 81 * <a href="http://libusbx.org">libusbx homepage</a>. 82 * 83 * This documentation is aimed at application developers wishing to 84 * communicate with USB peripherals from their own software. After reviewing 85 * this documentation, feedback and questions can be sent to the 86 * <a href="http://mailing-list.libusbx.org">libusbx-devel mailing list</a>. 87 * 88 * This documentation assumes knowledge of how to operate USB devices from 89 * a software standpoint (descriptors, configurations, interfaces, endpoints, 90 * control/bulk/interrupt/isochronous transfers, etc). Full information 91 * can be found in the <a href="http://www.usb.org/developers/docs/">USB 3.0 92 * Specification</a> which is available for free download. You can probably 93 * find less verbose introductions by searching the web. 94 * 95 * \section features Library features 96 * 97 * - All transfer types supported (control/bulk/interrupt/isochronous) 98 * - 2 transfer interfaces: 99 * -# Synchronous (simple) 100 * -# Asynchronous (more complicated, but more powerful) 101 * - Thread safe (although the asynchronous interface means that you 102 * usually won't need to thread) 103 * - Lightweight with lean API 104 * - Compatible with libusb-0.1 through the libusb-compat-0.1 translation layer 105 * - Hotplug support (on some platforms). See \ref hotplug. 106 * 107 * \section gettingstarted Getting Started 108 * 109 * To begin reading the API documentation, start with the Modules page which 110 * links to the different categories of libusbx's functionality. 111 * 112 * One decision you will have to make is whether to use the synchronous 113 * or the asynchronous data transfer interface. The \ref io documentation 114 * provides some insight into this topic. 115 * 116 * Some example programs can be found in the libusbx source distribution under 117 * the "examples" subdirectory. The libusbx homepage includes a list of 118 * real-life project examples which use libusbx. 119 * 120 * \section errorhandling Error handling 121 * 122 * libusbx functions typically return 0 on success or a negative error code 123 * on failure. These negative error codes relate to LIBUSB_ERROR constants 124 * which are listed on the \ref misc "miscellaneous" documentation page. 125 * 126 * \section msglog Debug message logging 127 * 128 * libusbx uses stderr for all logging. By default, logging is set to NONE, 129 * which means that no output will be produced. However, unless the library 130 * has been compiled with logging disabled, then any application calls to 131 * libusb_set_debug(), or the setting of the environmental variable 132 * LIBUSB_DEBUG outside of the application, can result in logging being 133 * produced. Your application should therefore not close stderr, but instead 134 * direct it to the null device if its output is undesireable. 135 * 136 * The libusb_set_debug() function can be used to enable logging of certain 137 * messages. Under standard configuration, libusbx doesn't really log much 138 * so you are advised to use this function to enable all error/warning/ 139 * informational messages. It will help debug problems with your software. 140 * 141 * The logged messages are unstructured. There is no one-to-one correspondence 142 * between messages being logged and success or failure return codes from 143 * libusbx functions. There is no format to the messages, so you should not 144 * try to capture or parse them. They are not and will not be localized. 145 * These messages are not intended to being passed to your application user; 146 * instead, you should interpret the error codes returned from libusbx functions 147 * and provide appropriate notification to the user. The messages are simply 148 * there to aid you as a programmer, and if you're confused because you're 149 * getting a strange error code from a libusbx function, enabling message 150 * logging may give you a suitable explanation. 151 * 152 * The LIBUSB_DEBUG environment variable can be used to enable message logging 153 * at run-time. This environment variable should be set to a log level number, 154 * which is interpreted the same as the libusb_set_debug() parameter. When this 155 * environment variable is set, the message logging verbosity level is fixed 156 * and libusb_set_debug() effectively does nothing. 157 * 158 * libusbx can be compiled without any logging functions, useful for embedded 159 * systems. In this case, libusb_set_debug() and the LIBUSB_DEBUG environment 160 * variable have no effects. 161 * 162 * libusbx can also be compiled with verbose debugging messages always. When 163 * the library is compiled in this way, all messages of all verbosities are 164 * always logged. libusb_set_debug() and the LIBUSB_DEBUG environment variable 165 * have no effects. 166 * 167 * \section remarks Other remarks 168 * 169 * libusbx does have imperfections. The \ref caveats "caveats" page attempts 170 * to document these. 171 */ 172 173 /** 174 * \page caveats Caveats 175 * 176 * \section devresets Device resets 177 * 178 * The libusb_reset_device() function allows you to reset a device. If your 179 * program has to call such a function, it should obviously be aware that 180 * the reset will cause device state to change (e.g. register values may be 181 * reset). 182 * 183 * The problem is that any other program could reset the device your program 184 * is working with, at any time. libusbx does not offer a mechanism to inform 185 * you when this has happened, so if someone else resets your device it will 186 * not be clear to your own program why the device state has changed. 187 * 188 * Ultimately, this is a limitation of writing drivers in userspace. 189 * Separation from the USB stack in the underlying kernel makes it difficult 190 * for the operating system to deliver such notifications to your program. 191 * The Linux kernel USB stack allows such reset notifications to be delivered 192 * to in-kernel USB drivers, but it is not clear how such notifications could 193 * be delivered to second-class drivers that live in userspace. 194 * 195 * \section blockonly Blocking-only functionality 196 * 197 * The functionality listed below is only available through synchronous, 198 * blocking functions. There are no asynchronous/non-blocking alternatives, 199 * and no clear ways of implementing these. 200 * 201 * - Configuration activation (libusb_set_configuration()) 202 * - Interface/alternate setting activation (libusb_set_interface_alt_setting()) 203 * - Releasing of interfaces (libusb_release_interface()) 204 * - Clearing of halt/stall condition (libusb_clear_halt()) 205 * - Device resets (libusb_reset_device()) 206 * 207 * \section configsel Configuration selection and handling 208 * 209 * When libusbx presents a device handle to an application, there is a chance 210 * that the corresponding device may be in unconfigured state. For devices 211 * with multiple configurations, there is also a chance that the configuration 212 * currently selected is not the one that the application wants to use. 213 * 214 * The obvious solution is to add a call to libusb_set_configuration() early 215 * on during your device initialization routines, but there are caveats to 216 * be aware of: 217 * -# If the device is already in the desired configuration, calling 218 * libusb_set_configuration() using the same configuration value will cause 219 * a lightweight device reset. This may not be desirable behaviour. 220 * -# libusbx will be unable to change configuration if the device is in 221 * another configuration and other programs or drivers have claimed 222 * interfaces under that configuration. 223 * -# In the case where the desired configuration is already active, libusbx 224 * may not even be able to perform a lightweight device reset. For example, 225 * take my USB keyboard with fingerprint reader: I'm interested in driving 226 * the fingerprint reader interface through libusbx, but the kernel's 227 * USB-HID driver will almost always have claimed the keyboard interface. 228 * Because the kernel has claimed an interface, it is not even possible to 229 * perform the lightweight device reset, so libusb_set_configuration() will 230 * fail. (Luckily the device in question only has a single configuration.) 231 * 232 * One solution to some of the above problems is to consider the currently 233 * active configuration. If the configuration we want is already active, then 234 * we don't have to select any configuration: 235 \code 236 cfg = libusb_get_configuration(dev); 237 if (cfg != desired) 238 libusb_set_configuration(dev, desired); 239 \endcode 240 * 241 * This is probably suitable for most scenarios, but is inherently racy: 242 * another application or driver may change the selected configuration 243 * <em>after</em> the libusb_get_configuration() call. 244 * 245 * Even in cases where libusb_set_configuration() succeeds, consider that other 246 * applications or drivers may change configuration after your application 247 * calls libusb_set_configuration(). 248 * 249 * One possible way to lock your device into a specific configuration is as 250 * follows: 251 * -# Set the desired configuration (or use the logic above to realise that 252 * it is already in the desired configuration) 253 * -# Claim the interface that you wish to use 254 * -# Check that the currently active configuration is the one that you want 255 * to use. 256 * 257 * The above method works because once an interface is claimed, no application 258 * or driver is able to select another configuration. 259 * 260 * \section earlycomp Early transfer completion 261 * 262 * NOTE: This section is currently Linux-centric. I am not sure if any of these 263 * considerations apply to Darwin or other platforms. 264 * 265 * When a transfer completes early (i.e. when less data is received/sent in 266 * any one packet than the transfer buffer allows for) then libusbx is designed 267 * to terminate the transfer immediately, not transferring or receiving any 268 * more data unless other transfers have been queued by the user. 269 * 270 * On legacy platforms, libusbx is unable to do this in all situations. After 271 * the incomplete packet occurs, "surplus" data may be transferred. For recent 272 * versions of libusbx, this information is kept (the data length of the 273 * transfer is updated) and, for device-to-host transfers, any surplus data was 274 * added to the buffer. Still, this is not a nice solution because it loses the 275 * information about the end of the short packet, and the user probably wanted 276 * that surplus data to arrive in the next logical transfer. 277 * 278 * 279 * \section zlp Zero length packets 280 * 281 * - libusbx is able to send a packet of zero length to an endpoint simply by 282 * submitting a transfer of zero length. 283 * - The \ref libusb_transfer_flags::LIBUSB_TRANSFER_ADD_ZERO_PACKET 284 * "LIBUSB_TRANSFER_ADD_ZERO_PACKET" flag is currently only supported on Linux. 285 */ 286 287 /** 288 * \page contexts Contexts 289 * 290 * It is possible that libusbx may be used simultaneously from two independent 291 * libraries linked into the same executable. For example, if your application 292 * has a plugin-like system which allows the user to dynamically load a range 293 * of modules into your program, it is feasible that two independently 294 * developed modules may both use libusbx. 295 * 296 * libusbx is written to allow for these multiple user scenarios. The two 297 * "instances" of libusbx will not interfere: libusb_set_debug() calls 298 * from one user will not affect the same settings for other users, other 299 * users can continue using libusbx after one of them calls libusb_exit(), etc. 300 * 301 * This is made possible through libusbx's <em>context</em> concept. When you 302 * call libusb_init(), you are (optionally) given a context. You can then pass 303 * this context pointer back into future libusbx functions. 304 * 305 * In order to keep things simple for more simplistic applications, it is 306 * legal to pass NULL to all functions requiring a context pointer (as long as 307 * you're sure no other code will attempt to use libusbx from the same process). 308 * When you pass NULL, the default context will be used. The default context 309 * is created the first time a process calls libusb_init() when no other 310 * context is alive. Contexts are destroyed during libusb_exit(). 311 * 312 * The default context is reference-counted and can be shared. That means that 313 * if libusb_init(NULL) is called twice within the same process, the two 314 * users end up sharing the same context. The deinitialization and freeing of 315 * the default context will only happen when the last user calls libusb_exit(). 316 * In other words, the default context is created and initialized when its 317 * reference count goes from 0 to 1, and is deinitialized and destroyed when 318 * its reference count goes from 1 to 0. 319 * 320 * You may be wondering why only a subset of libusbx functions require a 321 * context pointer in their function definition. Internally, libusbx stores 322 * context pointers in other objects (e.g. libusb_device instances) and hence 323 * can infer the context from those objects. 324 */ 325 326 /** 327 * @defgroup lib Library initialization/deinitialization 328 * This page details how to initialize and deinitialize libusbx. Initialization 329 * must be performed before using any libusbx functionality, and similarly you 330 * must not call any libusbx functions after deinitialization. 331 */ 332 333 /** 334 * @defgroup dev Device handling and enumeration 335 * The functionality documented below is designed to help with the following 336 * operations: 337 * - Enumerating the USB devices currently attached to the system 338 * - Choosing a device to operate from your software 339 * - Opening and closing the chosen device 340 * 341 * \section nutshell In a nutshell... 342 * 343 * The description below really makes things sound more complicated than they 344 * actually are. The following sequence of function calls will be suitable 345 * for almost all scenarios and does not require you to have such a deep 346 * understanding of the resource management issues: 347 * \code 348 // discover devices 349 libusb_device **list; 350 libusb_device *found = NULL; 351 ssize_t cnt = libusb_get_device_list(NULL, &list); 352 ssize_t i = 0; 353 int err = 0; 354 if (cnt < 0) 355 error(); 356 357 for (i = 0; i < cnt; i++) { 358 libusb_device *device = list[i]; 359 if (is_interesting(device)) { 360 found = device; 361 break; 362 } 363 } 364 365 if (found) { 366 libusb_device_handle *handle; 367 368 err = libusb_open(found, &handle); 369 if (err) 370 error(); 371 // etc 372 } 373 374 libusb_free_device_list(list, 1); 375 \endcode 376 * 377 * The two important points: 378 * - You asked libusb_free_device_list() to unreference the devices (2nd 379 * parameter) 380 * - You opened the device before freeing the list and unreferencing the 381 * devices 382 * 383 * If you ended up with a handle, you can now proceed to perform I/O on the 384 * device. 385 * 386 * \section devshandles Devices and device handles 387 * libusbx has a concept of a USB device, represented by the 388 * \ref libusb_device opaque type. A device represents a USB device that 389 * is currently or was previously connected to the system. Using a reference 390 * to a device, you can determine certain information about the device (e.g. 391 * you can read the descriptor data). 392 * 393 * The libusb_get_device_list() function can be used to obtain a list of 394 * devices currently connected to the system. This is known as device 395 * discovery. 396 * 397 * Just because you have a reference to a device does not mean it is 398 * necessarily usable. The device may have been unplugged, you may not have 399 * permission to operate such device, or another program or driver may be 400 * using the device. 401 * 402 * When you've found a device that you'd like to operate, you must ask 403 * libusbx to open the device using the libusb_open() function. Assuming 404 * success, libusbx then returns you a <em>device handle</em> 405 * (a \ref libusb_device_handle pointer). All "real" I/O operations then 406 * operate on the handle rather than the original device pointer. 407 * 408 * \section devref Device discovery and reference counting 409 * 410 * Device discovery (i.e. calling libusb_get_device_list()) returns a 411 * freshly-allocated list of devices. The list itself must be freed when 412 * you are done with it. libusbx also needs to know when it is OK to free 413 * the contents of the list - the devices themselves. 414 * 415 * To handle these issues, libusbx provides you with two separate items: 416 * - A function to free the list itself 417 * - A reference counting system for the devices inside 418 * 419 * New devices presented by the libusb_get_device_list() function all have a 420 * reference count of 1. You can increase and decrease reference count using 421 * libusb_ref_device() and libusb_unref_device(). A device is destroyed when 422 * its reference count reaches 0. 423 * 424 * With the above information in mind, the process of opening a device can 425 * be viewed as follows: 426 * -# Discover devices using libusb_get_device_list(). 427 * -# Choose the device that you want to operate, and call libusb_open(). 428 * -# Unref all devices in the discovered device list. 429 * -# Free the discovered device list. 430 * 431 * The order is important - you must not unreference the device before 432 * attempting to open it, because unreferencing it may destroy the device. 433 * 434 * For convenience, the libusb_free_device_list() function includes a 435 * parameter to optionally unreference all the devices in the list before 436 * freeing the list itself. This combines steps 3 and 4 above. 437 * 438 * As an implementation detail, libusb_open() actually adds a reference to 439 * the device in question. This is because the device remains available 440 * through the handle via libusb_get_device(). The reference is deleted during 441 * libusb_close(). 442 */ 443 444 /** @defgroup misc Miscellaneous */ 445 446 /* we traverse usbfs without knowing how many devices we are going to find. 447 * so we create this discovered_devs model which is similar to a linked-list 448 * which grows when required. it can be freed once discovery has completed, 449 * eliminating the need for a list node in the libusb_device structure 450 * itself. */ 451 #define DISCOVERED_DEVICES_SIZE_STEP 8 452 453 static struct discovered_devs *discovered_devs_alloc(void) 454 { 455 struct discovered_devs *ret = 456 malloc(sizeof(*ret) + (sizeof(void *) * DISCOVERED_DEVICES_SIZE_STEP)); 457 458 if (ret) { 459 ret->len = 0; 460 ret->capacity = DISCOVERED_DEVICES_SIZE_STEP; 461 } 462 return ret; 463 } 464 465 /* append a device to the discovered devices collection. may realloc itself, 466 * returning new discdevs. returns NULL on realloc failure. */ 467 struct discovered_devs *discovered_devs_append( 468 struct discovered_devs *discdevs, struct libusb_device *dev) 469 { 470 size_t len = discdevs->len; 471 size_t capacity; 472 473 /* if there is space, just append the device */ 474 if (len < discdevs->capacity) { 475 discdevs->devices[len] = libusb_ref_device(dev); 476 discdevs->len++; 477 return discdevs; 478 } 479 480 /* exceeded capacity, need to grow */ 481 usbi_dbg("need to increase capacity"); 482 capacity = discdevs->capacity + DISCOVERED_DEVICES_SIZE_STEP; 483 discdevs = usbi_reallocf(discdevs, 484 sizeof(*discdevs) + (sizeof(void *) * capacity)); 485 if (discdevs) { 486 discdevs->capacity = capacity; 487 discdevs->devices[len] = libusb_ref_device(dev); 488 discdevs->len++; 489 } 490 491 return discdevs; 492 } 493 494 static void discovered_devs_free(struct discovered_devs *discdevs) 495 { 496 size_t i; 497 498 for (i = 0; i < discdevs->len; i++) 499 libusb_unref_device(discdevs->devices[i]); 500 501 free(discdevs); 502 } 503 504 /* Allocate a new device with a specific session ID. The returned device has 505 * a reference count of 1. */ 506 struct libusb_device *usbi_alloc_device(struct libusb_context *ctx, 507 unsigned long session_id) 508 { 509 size_t priv_size = usbi_backend->device_priv_size; 510 struct libusb_device *dev = calloc(1, sizeof(*dev) + priv_size); 511 int r; 512 513 if (!dev) 514 return NULL; 515 516 r = usbi_mutex_init(&dev->lock, NULL); 517 if (r) { 518 free(dev); 519 return NULL; 520 } 521 522 dev->ctx = ctx; 523 dev->refcnt = 1; 524 dev->session_data = session_id; 525 dev->speed = LIBUSB_SPEED_UNKNOWN; 526 527 if (!libusb_has_capability(LIBUSB_CAP_HAS_HOTPLUG)) { 528 usbi_connect_device (dev); 529 } 530 531 return dev; 532 } 533 534 void usbi_connect_device(struct libusb_device *dev) 535 { 536 libusb_hotplug_message message; 537 ssize_t ret; 538 539 memset(&message, 0, sizeof(message)); 540 message.event = LIBUSB_HOTPLUG_EVENT_DEVICE_ARRIVED; 541 message.device = dev; 542 dev->attached = 1; 543 544 usbi_mutex_lock(&dev->ctx->usb_devs_lock); 545 list_add(&dev->list, &dev->ctx->usb_devs); 546 usbi_mutex_unlock(&dev->ctx->usb_devs_lock); 547 548 /* Signal that an event has occurred for this device if we support hotplug AND 549 * the hotplug pipe is ready. This prevents an event from getting raised during 550 * initial enumeration. */ 551 if (libusb_has_capability(LIBUSB_CAP_HAS_HOTPLUG) && dev->ctx->hotplug_pipe[1] > 0) { 552 ret = usbi_write(dev->ctx->hotplug_pipe[1], &message, sizeof(message)); 553 if (sizeof (message) != ret) { 554 usbi_err(DEVICE_CTX(dev), "error writing hotplug message"); 555 } 556 } 557 } 558 559 void usbi_disconnect_device(struct libusb_device *dev) 560 { 561 libusb_hotplug_message message; 562 struct libusb_context *ctx = dev->ctx; 563 ssize_t ret; 564 565 memset(&message, 0, sizeof(message)); 566 message.event = LIBUSB_HOTPLUG_EVENT_DEVICE_LEFT; 567 message.device = dev; 568 usbi_mutex_lock(&dev->lock); 569 dev->attached = 0; 570 usbi_mutex_unlock(&dev->lock); 571 572 usbi_mutex_lock(&ctx->usb_devs_lock); 573 list_del(&dev->list); 574 usbi_mutex_unlock(&ctx->usb_devs_lock); 575 576 /* Signal that an event has occurred for this device if we support hotplug AND 577 * the hotplug pipe is ready. This prevents an event from getting raised during 578 * initial enumeration. libusb_handle_events will take care of dereferencing the 579 * device. */ 580 if (libusb_has_capability(LIBUSB_CAP_HAS_HOTPLUG) && dev->ctx->hotplug_pipe[1] > 0) { 581 ret = usbi_write(dev->ctx->hotplug_pipe[1], &message, sizeof(message)); 582 if (sizeof(message) != ret) { 583 usbi_err(DEVICE_CTX(dev), "error writing hotplug message"); 584 } 585 } 586 } 587 588 /* Perform some final sanity checks on a newly discovered device. If this 589 * function fails (negative return code), the device should not be added 590 * to the discovered device list. */ 591 int usbi_sanitize_device(struct libusb_device *dev) 592 { 593 int r; 594 uint8_t num_configurations; 595 596 r = usbi_device_cache_descriptor(dev); 597 if (r < 0) 598 return r; 599 600 num_configurations = dev->device_descriptor.bNumConfigurations; 601 if (num_configurations > USB_MAXCONFIG) { 602 usbi_err(DEVICE_CTX(dev), "too many configurations"); 603 return LIBUSB_ERROR_IO; 604 } else if (0 == num_configurations) 605 usbi_dbg("zero configurations, maybe an unauthorized device"); 606 607 dev->num_configurations = num_configurations; 608 return 0; 609 } 610 611 /* Examine libusbx's internal list of known devices, looking for one with 612 * a specific session ID. Returns the matching device if it was found, and 613 * NULL otherwise. */ 614 struct libusb_device *usbi_get_device_by_session_id(struct libusb_context *ctx, 615 unsigned long session_id) 616 { 617 struct libusb_device *dev; 618 struct libusb_device *ret = NULL; 619 620 usbi_mutex_lock(&ctx->usb_devs_lock); 621 list_for_each_entry(dev, &ctx->usb_devs, list, struct libusb_device) 622 if (dev->session_data == session_id) { 623 ret = dev; 624 break; 625 } 626 usbi_mutex_unlock(&ctx->usb_devs_lock); 627 628 return ret; 629 } 630 631 /** @ingroup dev 632 * Returns a list of USB devices currently attached to the system. This is 633 * your entry point into finding a USB device to operate. 634 * 635 * You are expected to unreference all the devices when you are done with 636 * them, and then free the list with libusb_free_device_list(). Note that 637 * libusb_free_device_list() can unref all the devices for you. Be careful 638 * not to unreference a device you are about to open until after you have 639 * opened it. 640 * 641 * This return value of this function indicates the number of devices in 642 * the resultant list. The list is actually one element larger, as it is 643 * NULL-terminated. 644 * 645 * \param ctx the context to operate on, or NULL for the default context 646 * \param list output location for a list of devices. Must be later freed with 647 * libusb_free_device_list(). 648 * \returns the number of devices in the outputted list, or any 649 * \ref libusb_error according to errors encountered by the backend. 650 */ 651 ssize_t API_EXPORTED libusb_get_device_list(libusb_context *ctx, 652 libusb_device ***list) 653 { 654 struct discovered_devs *discdevs = discovered_devs_alloc(); 655 struct libusb_device **ret; 656 int r = 0; 657 ssize_t i, len; 658 USBI_GET_CONTEXT(ctx); 659 usbi_dbg(""); 660 661 if (!discdevs) 662 return LIBUSB_ERROR_NO_MEM; 663 664 if (libusb_has_capability(LIBUSB_CAP_HAS_HOTPLUG)) { 665 /* backend provides hotplug support */ 666 struct libusb_device *dev; 667 668 if (usbi_backend->hotplug_poll) 669 usbi_backend->hotplug_poll(); 670 671 usbi_mutex_lock(&ctx->usb_devs_lock); 672 list_for_each_entry(dev, &ctx->usb_devs, list, struct libusb_device) { 673 discdevs = discovered_devs_append(discdevs, dev); 674 675 if (!discdevs) { 676 r = LIBUSB_ERROR_NO_MEM; 677 break; 678 } 679 } 680 usbi_mutex_unlock(&ctx->usb_devs_lock); 681 } else { 682 /* backend does not provide hotplug support */ 683 r = usbi_backend->get_device_list(ctx, &discdevs); 684 } 685 686 if (r < 0) { 687 len = r; 688 goto out; 689 } 690 691 /* convert discovered_devs into a list */ 692 len = discdevs->len; 693 ret = calloc(len + 1, sizeof(struct libusb_device *)); 694 if (!ret) { 695 len = LIBUSB_ERROR_NO_MEM; 696 goto out; 697 } 698 699 ret[len] = NULL; 700 for (i = 0; i < len; i++) { 701 struct libusb_device *dev = discdevs->devices[i]; 702 ret[i] = libusb_ref_device(dev); 703 } 704 *list = ret; 705 706 out: 707 discovered_devs_free(discdevs); 708 return len; 709 } 710 711 /** \ingroup dev 712 * Frees a list of devices previously discovered using 713 * libusb_get_device_list(). If the unref_devices parameter is set, the 714 * reference count of each device in the list is decremented by 1. 715 * \param list the list to free 716 * \param unref_devices whether to unref the devices in the list 717 */ 718 void API_EXPORTED libusb_free_device_list(libusb_device **list, 719 int unref_devices) 720 { 721 if (!list) 722 return; 723 724 if (unref_devices) { 725 int i = 0; 726 struct libusb_device *dev; 727 728 while ((dev = list[i++]) != NULL) 729 libusb_unref_device(dev); 730 } 731 free(list); 732 } 733 734 /** \ingroup dev 735 * Get the number of the bus that a device is connected to. 736 * \param dev a device 737 * \returns the bus number 738 */ 739 uint8_t API_EXPORTED libusb_get_bus_number(libusb_device *dev) 740 { 741 return dev->bus_number; 742 } 743 744 /** \ingroup dev 745 * Get the number of the port that a device is connected to. 746 * Unless the OS does something funky, or you are hot-plugging USB extension cards, 747 * the port number returned by this call is usually guaranteed to be uniquely tied 748 * to a physical port, meaning that different devices plugged on the same physical 749 * port should return the same port number. 750 * 751 * But outside of this, there is no guarantee that the port number returned by this 752 * call will remain the same, or even match the order in which ports have been 753 * numbered by the HUB/HCD manufacturer. 754 * 755 * \param dev a device 756 * \returns the port number (0 if not available) 757 */ 758 uint8_t API_EXPORTED libusb_get_port_number(libusb_device *dev) 759 { 760 return dev->port_number; 761 } 762 763 /** \ingroup dev 764 * Get the list of all port numbers from root for the specified device 765 * 766 * Since version 1.0.16, \ref LIBUSBX_API_VERSION >= 0x01000102 767 * \param dev a device 768 * \param port_numbers the array that should contain the port numbers 769 * \param port_numbers_len the maximum length of the array. As per the USB 3.0 770 * specs, the current maximum limit for the depth is 7. 771 * \returns the number of elements filled 772 * \returns LIBUSB_ERROR_OVERFLOW if the array is too small 773 */ 774 int API_EXPORTED libusb_get_port_numbers(libusb_device *dev, 775 uint8_t* port_numbers, int port_numbers_len) 776 { 777 int i = port_numbers_len; 778 779 while(dev) { 780 // HCDs can be listed as devices and would have port #0 781 // TODO: see how the other backends want to implement HCDs as parents 782 if (dev->port_number == 0) 783 break; 784 i--; 785 if (i < 0) { 786 usbi_warn(DEVICE_CTX(dev), 787 "port numbers array too small"); 788 return LIBUSB_ERROR_OVERFLOW; 789 } 790 port_numbers[i] = dev->port_number; 791 dev = dev->parent_dev; 792 } 793 memmove(port_numbers, &port_numbers[i], port_numbers_len - i); 794 return port_numbers_len - i; 795 } 796 797 /** \ingroup dev 798 * Deprecated please use libusb_get_port_numbers instead. 799 */ 800 int API_EXPORTED libusb_get_port_path(libusb_context *ctx, libusb_device *dev, 801 uint8_t* port_numbers, uint8_t port_numbers_len) 802 { 803 UNUSED(ctx); 804 805 return libusb_get_port_numbers(dev, port_numbers, port_numbers_len); 806 } 807 808 /** \ingroup dev 809 * Get the the parent from the specified device. 810 * \param dev a device 811 * \returns the device parent or NULL if not available 812 * You should issue a \ref libusb_get_device_list() before calling this 813 * function and make sure that you only access the parent before issuing 814 * \ref libusb_free_device_list(). The reason is that libusbx currently does 815 * not maintain a permanent list of device instances, and therefore can 816 * only guarantee that parents are fully instantiated within a 817 * libusb_get_device_list() - libusb_free_device_list() block. 818 */ 819 DEFAULT_VISIBILITY 820 libusb_device * LIBUSB_CALL libusb_get_parent(libusb_device *dev) 821 { 822 return dev->parent_dev; 823 } 824 825 /** \ingroup dev 826 * Get the address of the device on the bus it is connected to. 827 * \param dev a device 828 * \returns the device address 829 */ 830 uint8_t API_EXPORTED libusb_get_device_address(libusb_device *dev) 831 { 832 return dev->device_address; 833 } 834 835 /** \ingroup dev 836 * Get the negotiated connection speed for a device. 837 * \param dev a device 838 * \returns a \ref libusb_speed code, where LIBUSB_SPEED_UNKNOWN means that 839 * the OS doesn't know or doesn't support returning the negotiated speed. 840 */ 841 int API_EXPORTED libusb_get_device_speed(libusb_device *dev) 842 { 843 return dev->speed; 844 } 845 846 static const struct libusb_endpoint_descriptor *find_endpoint( 847 struct libusb_config_descriptor *config, unsigned char endpoint) 848 { 849 int iface_idx; 850 for (iface_idx = 0; iface_idx < config->bNumInterfaces; iface_idx++) { 851 const struct libusb_interface *iface = &config->interface[iface_idx]; 852 int altsetting_idx; 853 854 for (altsetting_idx = 0; altsetting_idx < iface->num_altsetting; 855 altsetting_idx++) { 856 const struct libusb_interface_descriptor *altsetting 857 = &iface->altsetting[altsetting_idx]; 858 int ep_idx; 859 860 for (ep_idx = 0; ep_idx < altsetting->bNumEndpoints; ep_idx++) { 861 const struct libusb_endpoint_descriptor *ep = 862 &altsetting->endpoint[ep_idx]; 863 if (ep->bEndpointAddress == endpoint) 864 return ep; 865 } 866 } 867 } 868 return NULL; 869 } 870 871 /** \ingroup dev 872 * Convenience function to retrieve the wMaxPacketSize value for a particular 873 * endpoint in the active device configuration. 874 * 875 * This function was originally intended to be of assistance when setting up 876 * isochronous transfers, but a design mistake resulted in this function 877 * instead. It simply returns the wMaxPacketSize value without considering 878 * its contents. If you're dealing with isochronous transfers, you probably 879 * want libusb_get_max_iso_packet_size() instead. 880 * 881 * \param dev a device 882 * \param endpoint address of the endpoint in question 883 * \returns the wMaxPacketSize value 884 * \returns LIBUSB_ERROR_NOT_FOUND if the endpoint does not exist 885 * \returns LIBUSB_ERROR_OTHER on other failure 886 */ 887 int API_EXPORTED libusb_get_max_packet_size(libusb_device *dev, 888 unsigned char endpoint) 889 { 890 struct libusb_config_descriptor *config; 891 const struct libusb_endpoint_descriptor *ep; 892 int r; 893 894 r = libusb_get_active_config_descriptor(dev, &config); 895 if (r < 0) { 896 usbi_err(DEVICE_CTX(dev), 897 "could not retrieve active config descriptor"); 898 return LIBUSB_ERROR_OTHER; 899 } 900 901 ep = find_endpoint(config, endpoint); 902 if (!ep) 903 return LIBUSB_ERROR_NOT_FOUND; 904 905 r = ep->wMaxPacketSize; 906 libusb_free_config_descriptor(config); 907 return r; 908 } 909 910 /** \ingroup dev 911 * Calculate the maximum packet size which a specific endpoint is capable is 912 * sending or receiving in the duration of 1 microframe 913 * 914 * Only the active configuration is examined. The calculation is based on the 915 * wMaxPacketSize field in the endpoint descriptor as described in section 916 * 9.6.6 in the USB 2.0 specifications. 917 * 918 * If acting on an isochronous or interrupt endpoint, this function will 919 * multiply the value found in bits 0:10 by the number of transactions per 920 * microframe (determined by bits 11:12). Otherwise, this function just 921 * returns the numeric value found in bits 0:10. 922 * 923 * This function is useful for setting up isochronous transfers, for example 924 * you might pass the return value from this function to 925 * libusb_set_iso_packet_lengths() in order to set the length field of every 926 * isochronous packet in a transfer. 927 * 928 * Since v1.0.3. 929 * 930 * \param dev a device 931 * \param endpoint address of the endpoint in question 932 * \returns the maximum packet size which can be sent/received on this endpoint 933 * \returns LIBUSB_ERROR_NOT_FOUND if the endpoint does not exist 934 * \returns LIBUSB_ERROR_OTHER on other failure 935 */ 936 int API_EXPORTED libusb_get_max_iso_packet_size(libusb_device *dev, 937 unsigned char endpoint) 938 { 939 struct libusb_config_descriptor *config; 940 const struct libusb_endpoint_descriptor *ep; 941 enum libusb_transfer_type ep_type; 942 uint16_t val; 943 int r; 944 945 r = libusb_get_active_config_descriptor(dev, &config); 946 if (r < 0) { 947 usbi_err(DEVICE_CTX(dev), 948 "could not retrieve active config descriptor"); 949 return LIBUSB_ERROR_OTHER; 950 } 951 952 ep = find_endpoint(config, endpoint); 953 if (!ep) 954 return LIBUSB_ERROR_NOT_FOUND; 955 956 val = ep->wMaxPacketSize; 957 ep_type = (enum libusb_transfer_type) (ep->bmAttributes & 0x3); 958 libusb_free_config_descriptor(config); 959 960 r = val & 0x07ff; 961 if (ep_type == LIBUSB_TRANSFER_TYPE_ISOCHRONOUS 962 || ep_type == LIBUSB_TRANSFER_TYPE_INTERRUPT) 963 r *= (1 + ((val >> 11) & 3)); 964 return r; 965 } 966 967 /** \ingroup dev 968 * Increment the reference count of a device. 969 * \param dev the device to reference 970 * \returns the same device 971 */ 972 DEFAULT_VISIBILITY 973 libusb_device * LIBUSB_CALL libusb_ref_device(libusb_device *dev) 974 { 975 usbi_mutex_lock(&dev->lock); 976 dev->refcnt++; 977 usbi_mutex_unlock(&dev->lock); 978 return dev; 979 } 980 981 /** \ingroup dev 982 * Decrement the reference count of a device. If the decrement operation 983 * causes the reference count to reach zero, the device shall be destroyed. 984 * \param dev the device to unreference 985 */ 986 void API_EXPORTED libusb_unref_device(libusb_device *dev) 987 { 988 int refcnt; 989 990 if (!dev) 991 return; 992 993 usbi_mutex_lock(&dev->lock); 994 refcnt = --dev->refcnt; 995 usbi_mutex_unlock(&dev->lock); 996 997 if (refcnt == 0) { 998 usbi_dbg("destroy device %d.%d", dev->bus_number, dev->device_address); 999 1000 libusb_unref_device(dev->parent_dev); 1001 1002 if (usbi_backend->destroy_device) 1003 usbi_backend->destroy_device(dev); 1004 1005 if (!libusb_has_capability(LIBUSB_CAP_HAS_HOTPLUG)) { 1006 /* backend does not support hotplug */ 1007 usbi_disconnect_device(dev); 1008 } 1009 1010 usbi_mutex_destroy(&dev->lock); 1011 free(dev); 1012 } 1013 } 1014 1015 /* 1016 * Interrupt the iteration of the event handling thread, so that it picks 1017 * up the new fd. 1018 */ 1019 void usbi_fd_notification(struct libusb_context *ctx) 1020 { 1021 unsigned char dummy = 1; 1022 ssize_t r; 1023 1024 if (ctx == NULL) 1025 return; 1026 1027 /* record that we are messing with poll fds */ 1028 usbi_mutex_lock(&ctx->pollfd_modify_lock); 1029 ctx->pollfd_modify++; 1030 usbi_mutex_unlock(&ctx->pollfd_modify_lock); 1031 1032 /* write some data on control pipe to interrupt event handlers */ 1033 r = usbi_write(ctx->ctrl_pipe[1], &dummy, sizeof(dummy)); 1034 if (r <= 0) { 1035 usbi_warn(ctx, "internal signalling write failed"); 1036 usbi_mutex_lock(&ctx->pollfd_modify_lock); 1037 ctx->pollfd_modify--; 1038 usbi_mutex_unlock(&ctx->pollfd_modify_lock); 1039 return; 1040 } 1041 1042 /* take event handling lock */ 1043 libusb_lock_events(ctx); 1044 1045 /* read the dummy data */ 1046 r = usbi_read(ctx->ctrl_pipe[0], &dummy, sizeof(dummy)); 1047 if (r <= 0) 1048 usbi_warn(ctx, "internal signalling read failed"); 1049 1050 /* we're done with modifying poll fds */ 1051 usbi_mutex_lock(&ctx->pollfd_modify_lock); 1052 ctx->pollfd_modify--; 1053 usbi_mutex_unlock(&ctx->pollfd_modify_lock); 1054 1055 /* Release event handling lock and wake up event waiters */ 1056 libusb_unlock_events(ctx); 1057 } 1058 1059 /** \ingroup dev 1060 * Open a device and obtain a device handle. A handle allows you to perform 1061 * I/O on the device in question. 1062 * 1063 * Internally, this function adds a reference to the device and makes it 1064 * available to you through libusb_get_device(). This reference is removed 1065 * during libusb_close(). 1066 * 1067 * This is a non-blocking function; no requests are sent over the bus. 1068 * 1069 * \param dev the device to open 1070 * \param handle output location for the returned device handle pointer. Only 1071 * populated when the return code is 0. 1072 * \returns 0 on success 1073 * \returns LIBUSB_ERROR_NO_MEM on memory allocation failure 1074 * \returns LIBUSB_ERROR_ACCESS if the user has insufficient permissions 1075 * \returns LIBUSB_ERROR_NO_DEVICE if the device has been disconnected 1076 * \returns another LIBUSB_ERROR code on other failure 1077 */ 1078 int API_EXPORTED libusb_open(libusb_device *dev, 1079 libusb_device_handle **handle) 1080 { 1081 struct libusb_context *ctx = DEVICE_CTX(dev); 1082 struct libusb_device_handle *_handle; 1083 size_t priv_size = usbi_backend->device_handle_priv_size; 1084 int r; 1085 usbi_dbg("open %d.%d", dev->bus_number, dev->device_address); 1086 1087 if (!dev->attached) { 1088 return LIBUSB_ERROR_NO_DEVICE; 1089 } 1090 1091 _handle = malloc(sizeof(*_handle) + priv_size); 1092 if (!_handle) 1093 return LIBUSB_ERROR_NO_MEM; 1094 1095 r = usbi_mutex_init(&_handle->lock, NULL); 1096 if (r) { 1097 free(_handle); 1098 return LIBUSB_ERROR_OTHER; 1099 } 1100 1101 _handle->dev = libusb_ref_device(dev); 1102 _handle->auto_detach_kernel_driver = 0; 1103 _handle->claimed_interfaces = 0; 1104 memset(&_handle->os_priv, 0, priv_size); 1105 1106 r = usbi_backend->open(_handle); 1107 if (r < 0) { 1108 usbi_dbg("open %d.%d returns %d", dev->bus_number, dev->device_address, r); 1109 libusb_unref_device(dev); 1110 usbi_mutex_destroy(&_handle->lock); 1111 free(_handle); 1112 return r; 1113 } 1114 1115 usbi_mutex_lock(&ctx->open_devs_lock); 1116 list_add(&_handle->list, &ctx->open_devs); 1117 usbi_mutex_unlock(&ctx->open_devs_lock); 1118 *handle = _handle; 1119 1120 /* At this point, we want to interrupt any existing event handlers so 1121 * that they realise the addition of the new device's poll fd. One 1122 * example when this is desirable is if the user is running a separate 1123 * dedicated libusbx events handling thread, which is running with a long 1124 * or infinite timeout. We want to interrupt that iteration of the loop, 1125 * so that it picks up the new fd, and then continues. */ 1126 usbi_fd_notification(ctx); 1127 1128 return 0; 1129 } 1130 1131 /** \ingroup dev 1132 * Convenience function for finding a device with a particular 1133 * <tt>idVendor</tt>/<tt>idProduct</tt> combination. This function is intended 1134 * for those scenarios where you are using libusbx to knock up a quick test 1135 * application - it allows you to avoid calling libusb_get_device_list() and 1136 * worrying about traversing/freeing the list. 1137 * 1138 * This function has limitations and is hence not intended for use in real 1139 * applications: if multiple devices have the same IDs it will only 1140 * give you the first one, etc. 1141 * 1142 * \param ctx the context to operate on, or NULL for the default context 1143 * \param vendor_id the idVendor value to search for 1144 * \param product_id the idProduct value to search for 1145 * \returns a handle for the first found device, or NULL on error or if the 1146 * device could not be found. */ 1147 DEFAULT_VISIBILITY 1148 libusb_device_handle * LIBUSB_CALL libusb_open_device_with_vid_pid( 1149 libusb_context *ctx, uint16_t vendor_id, uint16_t product_id) 1150 { 1151 struct libusb_device **devs; 1152 struct libusb_device *found = NULL; 1153 struct libusb_device *dev; 1154 struct libusb_device_handle *handle = NULL; 1155 size_t i = 0; 1156 int r; 1157 1158 if (libusb_get_device_list(ctx, &devs) < 0) 1159 return NULL; 1160 1161 while ((dev = devs[i++]) != NULL) { 1162 struct libusb_device_descriptor desc; 1163 r = libusb_get_device_descriptor(dev, &desc); 1164 if (r < 0) 1165 goto out; 1166 if (desc.idVendor == vendor_id && desc.idProduct == product_id) { 1167 found = dev; 1168 break; 1169 } 1170 } 1171 1172 if (found) { 1173 r = libusb_open(found, &handle); 1174 if (r < 0) 1175 handle = NULL; 1176 } 1177 1178 out: 1179 libusb_free_device_list(devs, 1); 1180 return handle; 1181 } 1182 1183 static void do_close(struct libusb_context *ctx, 1184 struct libusb_device_handle *dev_handle) 1185 { 1186 struct usbi_transfer *itransfer; 1187 struct usbi_transfer *tmp; 1188 1189 libusb_lock_events(ctx); 1190 1191 /* remove any transfers in flight that are for this device */ 1192 usbi_mutex_lock(&ctx->flying_transfers_lock); 1193 1194 /* safe iteration because transfers may be being deleted */ 1195 list_for_each_entry_safe(itransfer, tmp, &ctx->flying_transfers, list, struct usbi_transfer) { 1196 struct libusb_transfer *transfer = 1197 USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer); 1198 1199 if (transfer->dev_handle != dev_handle) 1200 continue; 1201 1202 if (!(itransfer->flags & USBI_TRANSFER_DEVICE_DISAPPEARED)) { 1203 usbi_err(ctx, "Device handle closed while transfer was still being processed, but the device is still connected as far as we know"); 1204 1205 if (itransfer->flags & USBI_TRANSFER_CANCELLING) 1206 usbi_warn(ctx, "A cancellation for an in-flight transfer hasn't completed but closing the device handle"); 1207 else 1208 usbi_err(ctx, "A cancellation hasn't even been scheduled on the transfer for which the device is closing"); 1209 } 1210 1211 /* remove from the list of in-flight transfers and make sure 1212 * we don't accidentally use the device handle in the future 1213 * (or that such accesses will be easily caught and identified as a crash) 1214 */ 1215 usbi_mutex_lock(&itransfer->lock); 1216 list_del(&itransfer->list); 1217 transfer->dev_handle = NULL; 1218 usbi_mutex_unlock(&itransfer->lock); 1219 1220 /* it is up to the user to free up the actual transfer struct. this is 1221 * just making sure that we don't attempt to process the transfer after 1222 * the device handle is invalid 1223 */ 1224 usbi_dbg("Removed transfer %p from the in-flight list because device handle %p closed", 1225 transfer, dev_handle); 1226 } 1227 usbi_mutex_unlock(&ctx->flying_transfers_lock); 1228 1229 libusb_unlock_events(ctx); 1230 1231 usbi_mutex_lock(&ctx->open_devs_lock); 1232 list_del(&dev_handle->list); 1233 usbi_mutex_unlock(&ctx->open_devs_lock); 1234 1235 usbi_backend->close(dev_handle); 1236 libusb_unref_device(dev_handle->dev); 1237 usbi_mutex_destroy(&dev_handle->lock); 1238 free(dev_handle); 1239 } 1240 1241 /** \ingroup dev 1242 * Close a device handle. Should be called on all open handles before your 1243 * application exits. 1244 * 1245 * Internally, this function destroys the reference that was added by 1246 * libusb_open() on the given device. 1247 * 1248 * This is a non-blocking function; no requests are sent over the bus. 1249 * 1250 * \param dev_handle the handle to close 1251 */ 1252 void API_EXPORTED libusb_close(libusb_device_handle *dev_handle) 1253 { 1254 struct libusb_context *ctx; 1255 unsigned char dummy = 1; 1256 ssize_t r; 1257 1258 if (!dev_handle) 1259 return; 1260 usbi_dbg(""); 1261 1262 ctx = HANDLE_CTX(dev_handle); 1263 1264 /* Similarly to libusb_open(), we want to interrupt all event handlers 1265 * at this point. More importantly, we want to perform the actual close of 1266 * the device while holding the event handling lock (preventing any other 1267 * thread from doing event handling) because we will be removing a file 1268 * descriptor from the polling loop. */ 1269 1270 /* record that we are messing with poll fds */ 1271 usbi_mutex_lock(&ctx->pollfd_modify_lock); 1272 ctx->pollfd_modify++; 1273 usbi_mutex_unlock(&ctx->pollfd_modify_lock); 1274 1275 /* write some data on control pipe to interrupt event handlers */ 1276 r = usbi_write(ctx->ctrl_pipe[1], &dummy, sizeof(dummy)); 1277 if (r <= 0) { 1278 usbi_warn(ctx, "internal signalling write failed, closing anyway"); 1279 do_close(ctx, dev_handle); 1280 usbi_mutex_lock(&ctx->pollfd_modify_lock); 1281 ctx->pollfd_modify--; 1282 usbi_mutex_unlock(&ctx->pollfd_modify_lock); 1283 return; 1284 } 1285 1286 /* take event handling lock */ 1287 libusb_lock_events(ctx); 1288 1289 /* read the dummy data */ 1290 r = usbi_read(ctx->ctrl_pipe[0], &dummy, sizeof(dummy)); 1291 if (r <= 0) 1292 usbi_warn(ctx, "internal signalling read failed, closing anyway"); 1293 1294 /* Close the device */ 1295 do_close(ctx, dev_handle); 1296 1297 /* we're done with modifying poll fds */ 1298 usbi_mutex_lock(&ctx->pollfd_modify_lock); 1299 ctx->pollfd_modify--; 1300 usbi_mutex_unlock(&ctx->pollfd_modify_lock); 1301 1302 /* Release event handling lock and wake up event waiters */ 1303 libusb_unlock_events(ctx); 1304 } 1305 1306 /** \ingroup dev 1307 * Get the underlying device for a handle. This function does not modify 1308 * the reference count of the returned device, so do not feel compelled to 1309 * unreference it when you are done. 1310 * \param dev_handle a device handle 1311 * \returns the underlying device 1312 */ 1313 DEFAULT_VISIBILITY 1314 libusb_device * LIBUSB_CALL libusb_get_device(libusb_device_handle *dev_handle) 1315 { 1316 return dev_handle->dev; 1317 } 1318 1319 /** \ingroup dev 1320 * Determine the bConfigurationValue of the currently active configuration. 1321 * 1322 * You could formulate your own control request to obtain this information, 1323 * but this function has the advantage that it may be able to retrieve the 1324 * information from operating system caches (no I/O involved). 1325 * 1326 * If the OS does not cache this information, then this function will block 1327 * while a control transfer is submitted to retrieve the information. 1328 * 1329 * This function will return a value of 0 in the <tt>config</tt> output 1330 * parameter if the device is in unconfigured state. 1331 * 1332 * \param dev a device handle 1333 * \param config output location for the bConfigurationValue of the active 1334 * configuration (only valid for return code 0) 1335 * \returns 0 on success 1336 * \returns LIBUSB_ERROR_NO_DEVICE if the device has been disconnected 1337 * \returns another LIBUSB_ERROR code on other failure 1338 */ 1339 int API_EXPORTED libusb_get_configuration(libusb_device_handle *dev, 1340 int *config) 1341 { 1342 int r = LIBUSB_ERROR_NOT_SUPPORTED; 1343 1344 usbi_dbg(""); 1345 if (usbi_backend->get_configuration) 1346 r = usbi_backend->get_configuration(dev, config); 1347 1348 if (r == LIBUSB_ERROR_NOT_SUPPORTED) { 1349 uint8_t tmp = 0; 1350 usbi_dbg("falling back to control message"); 1351 r = libusb_control_transfer(dev, LIBUSB_ENDPOINT_IN, 1352 LIBUSB_REQUEST_GET_CONFIGURATION, 0, 0, &tmp, 1, 1000); 1353 if (r == 0) { 1354 usbi_err(HANDLE_CTX(dev), "zero bytes returned in ctrl transfer?"); 1355 r = LIBUSB_ERROR_IO; 1356 } else if (r == 1) { 1357 r = 0; 1358 *config = tmp; 1359 } else { 1360 usbi_dbg("control failed, error %d", r); 1361 } 1362 } 1363 1364 if (r == 0) 1365 usbi_dbg("active config %d", *config); 1366 1367 return r; 1368 } 1369 1370 /** \ingroup dev 1371 * Set the active configuration for a device. 1372 * 1373 * The operating system may or may not have already set an active 1374 * configuration on the device. It is up to your application to ensure the 1375 * correct configuration is selected before you attempt to claim interfaces 1376 * and perform other operations. 1377 * 1378 * If you call this function on a device already configured with the selected 1379 * configuration, then this function will act as a lightweight device reset: 1380 * it will issue a SET_CONFIGURATION request using the current configuration, 1381 * causing most USB-related device state to be reset (altsetting reset to zero, 1382 * endpoint halts cleared, toggles reset). 1383 * 1384 * You cannot change/reset configuration if your application has claimed 1385 * interfaces. It is advised to set the desired configuration before claiming 1386 * interfaces. 1387 * 1388 * Alternatively you can call libusb_release_interface() first. Note if you 1389 * do things this way you must ensure that auto_detach_kernel_driver for 1390 * <tt>dev</tt> is 0, otherwise the kernel driver will be re-attached when you 1391 * release the interface(s). 1392 * 1393 * You cannot change/reset configuration if other applications or drivers have 1394 * claimed interfaces. 1395 * 1396 * A configuration value of -1 will put the device in unconfigured state. 1397 * The USB specifications state that a configuration value of 0 does this, 1398 * however buggy devices exist which actually have a configuration 0. 1399 * 1400 * You should always use this function rather than formulating your own 1401 * SET_CONFIGURATION control request. This is because the underlying operating 1402 * system needs to know when such changes happen. 1403 * 1404 * This is a blocking function. 1405 * 1406 * \param dev a device handle 1407 * \param configuration the bConfigurationValue of the configuration you 1408 * wish to activate, or -1 if you wish to put the device in unconfigured state 1409 * \returns 0 on success 1410 * \returns LIBUSB_ERROR_NOT_FOUND if the requested configuration does not exist 1411 * \returns LIBUSB_ERROR_BUSY if interfaces are currently claimed 1412 * \returns LIBUSB_ERROR_NO_DEVICE if the device has been disconnected 1413 * \returns another LIBUSB_ERROR code on other failure 1414 * \see libusb_set_auto_detach_kernel_driver() 1415 */ 1416 int API_EXPORTED libusb_set_configuration(libusb_device_handle *dev, 1417 int configuration) 1418 { 1419 usbi_dbg("configuration %d", configuration); 1420 return usbi_backend->set_configuration(dev, configuration); 1421 } 1422 1423 /** \ingroup dev 1424 * Claim an interface on a given device handle. You must claim the interface 1425 * you wish to use before you can perform I/O on any of its endpoints. 1426 * 1427 * It is legal to attempt to claim an already-claimed interface, in which 1428 * case libusbx just returns 0 without doing anything. 1429 * 1430 * If auto_detach_kernel_driver is set to 1 for <tt>dev</tt>, the kernel driver 1431 * will be detached if necessary, on failure the detach error is returned. 1432 * 1433 * Claiming of interfaces is a purely logical operation; it does not cause 1434 * any requests to be sent over the bus. Interface claiming is used to 1435 * instruct the underlying operating system that your application wishes 1436 * to take ownership of the interface. 1437 * 1438 * This is a non-blocking function. 1439 * 1440 * \param dev a device handle 1441 * \param interface_number the <tt>bInterfaceNumber</tt> of the interface you 1442 * wish to claim 1443 * \returns 0 on success 1444 * \returns LIBUSB_ERROR_NOT_FOUND if the requested interface does not exist 1445 * \returns LIBUSB_ERROR_BUSY if another program or driver has claimed the 1446 * interface 1447 * \returns LIBUSB_ERROR_NO_DEVICE if the device has been disconnected 1448 * \returns a LIBUSB_ERROR code on other failure 1449 * \see libusb_set_auto_detach_kernel_driver() 1450 */ 1451 int API_EXPORTED libusb_claim_interface(libusb_device_handle *dev, 1452 int interface_number) 1453 { 1454 int r = 0; 1455 1456 usbi_dbg("interface %d", interface_number); 1457 if (interface_number >= USB_MAXINTERFACES) 1458 return LIBUSB_ERROR_INVALID_PARAM; 1459 1460 if (!dev->dev->attached) 1461 return LIBUSB_ERROR_NO_DEVICE; 1462 1463 usbi_mutex_lock(&dev->lock); 1464 if (dev->claimed_interfaces & (1 << interface_number)) 1465 goto out; 1466 1467 r = usbi_backend->claim_interface(dev, interface_number); 1468 if (r == 0) 1469 dev->claimed_interfaces |= 1 << interface_number; 1470 1471 out: 1472 usbi_mutex_unlock(&dev->lock); 1473 return r; 1474 } 1475 1476 /** \ingroup dev 1477 * Release an interface previously claimed with libusb_claim_interface(). You 1478 * should release all claimed interfaces before closing a device handle. 1479 * 1480 * This is a blocking function. A SET_INTERFACE control request will be sent 1481 * to the device, resetting interface state to the first alternate setting. 1482 * 1483 * If auto_detach_kernel_driver is set to 1 for <tt>dev</tt>, the kernel 1484 * driver will be re-attached after releasing the interface. 1485 * 1486 * \param dev a device handle 1487 * \param interface_number the <tt>bInterfaceNumber</tt> of the 1488 * previously-claimed interface 1489 * \returns 0 on success 1490 * \returns LIBUSB_ERROR_NOT_FOUND if the interface was not claimed 1491 * \returns LIBUSB_ERROR_NO_DEVICE if the device has been disconnected 1492 * \returns another LIBUSB_ERROR code on other failure 1493 * \see libusb_set_auto_detach_kernel_driver() 1494 */ 1495 int API_EXPORTED libusb_release_interface(libusb_device_handle *dev, 1496 int interface_number) 1497 { 1498 int r; 1499 1500 usbi_dbg("interface %d", interface_number); 1501 if (interface_number >= USB_MAXINTERFACES) 1502 return LIBUSB_ERROR_INVALID_PARAM; 1503 1504 usbi_mutex_lock(&dev->lock); 1505 if (!(dev->claimed_interfaces & (1 << interface_number))) { 1506 r = LIBUSB_ERROR_NOT_FOUND; 1507 goto out; 1508 } 1509 1510 r = usbi_backend->release_interface(dev, interface_number); 1511 if (r == 0) 1512 dev->claimed_interfaces &= ~(1 << interface_number); 1513 1514 out: 1515 usbi_mutex_unlock(&dev->lock); 1516 return r; 1517 } 1518 1519 /** \ingroup dev 1520 * Activate an alternate setting for an interface. The interface must have 1521 * been previously claimed with libusb_claim_interface(). 1522 * 1523 * You should always use this function rather than formulating your own 1524 * SET_INTERFACE control request. This is because the underlying operating 1525 * system needs to know when such changes happen. 1526 * 1527 * This is a blocking function. 1528 * 1529 * \param dev a device handle 1530 * \param interface_number the <tt>bInterfaceNumber</tt> of the 1531 * previously-claimed interface 1532 * \param alternate_setting the <tt>bAlternateSetting</tt> of the alternate 1533 * setting to activate 1534 * \returns 0 on success 1535 * \returns LIBUSB_ERROR_NOT_FOUND if the interface was not claimed, or the 1536 * requested alternate setting does not exist 1537 * \returns LIBUSB_ERROR_NO_DEVICE if the device has been disconnected 1538 * \returns another LIBUSB_ERROR code on other failure 1539 */ 1540 int API_EXPORTED libusb_set_interface_alt_setting(libusb_device_handle *dev, 1541 int interface_number, int alternate_setting) 1542 { 1543 usbi_dbg("interface %d altsetting %d", 1544 interface_number, alternate_setting); 1545 if (interface_number >= USB_MAXINTERFACES) 1546 return LIBUSB_ERROR_INVALID_PARAM; 1547 1548 usbi_mutex_lock(&dev->lock); 1549 if (!dev->dev->attached) { 1550 usbi_mutex_unlock(&dev->lock); 1551 return LIBUSB_ERROR_NO_DEVICE; 1552 } 1553 1554 if (!(dev->claimed_interfaces & (1 << interface_number))) { 1555 usbi_mutex_unlock(&dev->lock); 1556 return LIBUSB_ERROR_NOT_FOUND; 1557 } 1558 usbi_mutex_unlock(&dev->lock); 1559 1560 return usbi_backend->set_interface_altsetting(dev, interface_number, 1561 alternate_setting); 1562 } 1563 1564 /** \ingroup dev 1565 * Clear the halt/stall condition for an endpoint. Endpoints with halt status 1566 * are unable to receive or transmit data until the halt condition is stalled. 1567 * 1568 * You should cancel all pending transfers before attempting to clear the halt 1569 * condition. 1570 * 1571 * This is a blocking function. 1572 * 1573 * \param dev a device handle 1574 * \param endpoint the endpoint to clear halt status 1575 * \returns 0 on success 1576 * \returns LIBUSB_ERROR_NOT_FOUND if the endpoint does not exist 1577 * \returns LIBUSB_ERROR_NO_DEVICE if the device has been disconnected 1578 * \returns another LIBUSB_ERROR code on other failure 1579 */ 1580 int API_EXPORTED libusb_clear_halt(libusb_device_handle *dev, 1581 unsigned char endpoint) 1582 { 1583 usbi_dbg("endpoint %x", endpoint); 1584 if (!dev->dev->attached) 1585 return LIBUSB_ERROR_NO_DEVICE; 1586 1587 return usbi_backend->clear_halt(dev, endpoint); 1588 } 1589 1590 /** \ingroup dev 1591 * Perform a USB port reset to reinitialize a device. The system will attempt 1592 * to restore the previous configuration and alternate settings after the 1593 * reset has completed. 1594 * 1595 * If the reset fails, the descriptors change, or the previous state cannot be 1596 * restored, the device will appear to be disconnected and reconnected. This 1597 * means that the device handle is no longer valid (you should close it) and 1598 * rediscover the device. A return code of LIBUSB_ERROR_NOT_FOUND indicates 1599 * when this is the case. 1600 * 1601 * This is a blocking function which usually incurs a noticeable delay. 1602 * 1603 * \param dev a handle of the device to reset 1604 * \returns 0 on success 1605 * \returns LIBUSB_ERROR_NOT_FOUND if re-enumeration is required, or if the 1606 * device has been disconnected 1607 * \returns another LIBUSB_ERROR code on other failure 1608 */ 1609 int API_EXPORTED libusb_reset_device(libusb_device_handle *dev) 1610 { 1611 usbi_dbg(""); 1612 if (!dev->dev->attached) 1613 return LIBUSB_ERROR_NO_DEVICE; 1614 1615 return usbi_backend->reset_device(dev); 1616 } 1617 1618 /** \ingroup dev 1619 * Determine if a kernel driver is active on an interface. If a kernel driver 1620 * is active, you cannot claim the interface, and libusbx will be unable to 1621 * perform I/O. 1622 * 1623 * This functionality is not available on Windows. 1624 * 1625 * \param dev a device handle 1626 * \param interface_number the interface to check 1627 * \returns 0 if no kernel driver is active 1628 * \returns 1 if a kernel driver is active 1629 * \returns LIBUSB_ERROR_NO_DEVICE if the device has been disconnected 1630 * \returns LIBUSB_ERROR_NOT_SUPPORTED on platforms where the functionality 1631 * is not available 1632 * \returns another LIBUSB_ERROR code on other failure 1633 * \see libusb_detach_kernel_driver() 1634 */ 1635 int API_EXPORTED libusb_kernel_driver_active(libusb_device_handle *dev, 1636 int interface_number) 1637 { 1638 usbi_dbg("interface %d", interface_number); 1639 1640 if (!dev->dev->attached) 1641 return LIBUSB_ERROR_NO_DEVICE; 1642 1643 if (usbi_backend->kernel_driver_active) 1644 return usbi_backend->kernel_driver_active(dev, interface_number); 1645 else 1646 return LIBUSB_ERROR_NOT_SUPPORTED; 1647 } 1648 1649 /** \ingroup dev 1650 * Detach a kernel driver from an interface. If successful, you will then be 1651 * able to claim the interface and perform I/O. 1652 * 1653 * This functionality is not available on Darwin or Windows. 1654 * 1655 * Note that libusbx itself also talks to the device through a special kernel 1656 * driver, if this driver is already attached to the device, this call will 1657 * not detach it and return LIBUSB_ERROR_NOT_FOUND. 1658 * 1659 * \param dev a device handle 1660 * \param interface_number the interface to detach the driver from 1661 * \returns 0 on success 1662 * \returns LIBUSB_ERROR_NOT_FOUND if no kernel driver was active 1663 * \returns LIBUSB_ERROR_INVALID_PARAM if the interface does not exist 1664 * \returns LIBUSB_ERROR_NO_DEVICE if the device has been disconnected 1665 * \returns LIBUSB_ERROR_NOT_SUPPORTED on platforms where the functionality 1666 * is not available 1667 * \returns another LIBUSB_ERROR code on other failure 1668 * \see libusb_kernel_driver_active() 1669 */ 1670 int API_EXPORTED libusb_detach_kernel_driver(libusb_device_handle *dev, 1671 int interface_number) 1672 { 1673 usbi_dbg("interface %d", interface_number); 1674 1675 if (!dev->dev->attached) 1676 return LIBUSB_ERROR_NO_DEVICE; 1677 1678 if (usbi_backend->detach_kernel_driver) 1679 return usbi_backend->detach_kernel_driver(dev, interface_number); 1680 else 1681 return LIBUSB_ERROR_NOT_SUPPORTED; 1682 } 1683 1684 /** \ingroup dev 1685 * Re-attach an interface's kernel driver, which was previously detached 1686 * using libusb_detach_kernel_driver(). This call is only effective on 1687 * Linux and returns LIBUSB_ERROR_NOT_SUPPORTED on all other platforms. 1688 * 1689 * This functionality is not available on Darwin or Windows. 1690 * 1691 * \param dev a device handle 1692 * \param interface_number the interface to attach the driver from 1693 * \returns 0 on success 1694 * \returns LIBUSB_ERROR_NOT_FOUND if no kernel driver was active 1695 * \returns LIBUSB_ERROR_INVALID_PARAM if the interface does not exist 1696 * \returns LIBUSB_ERROR_NO_DEVICE if the device has been disconnected 1697 * \returns LIBUSB_ERROR_NOT_SUPPORTED on platforms where the functionality 1698 * is not available 1699 * \returns LIBUSB_ERROR_BUSY if the driver cannot be attached because the 1700 * interface is claimed by a program or driver 1701 * \returns another LIBUSB_ERROR code on other failure 1702 * \see libusb_kernel_driver_active() 1703 */ 1704 int API_EXPORTED libusb_attach_kernel_driver(libusb_device_handle *dev, 1705 int interface_number) 1706 { 1707 usbi_dbg("interface %d", interface_number); 1708 1709 if (!dev->dev->attached) 1710 return LIBUSB_ERROR_NO_DEVICE; 1711 1712 if (usbi_backend->attach_kernel_driver) 1713 return usbi_backend->attach_kernel_driver(dev, interface_number); 1714 else 1715 return LIBUSB_ERROR_NOT_SUPPORTED; 1716 } 1717 1718 /** \ingroup dev 1719 * Enable/disable libusbx's automatic kernel driver detachment. When this is 1720 * enabled libusbx will automatically detach the kernel driver on an interface 1721 * when claiming the interface, and attach it when releasing the interface. 1722 * 1723 * Automatic kernel driver detachment is disabled on newly opened device 1724 * handles by default. 1725 * 1726 * On platforms which do not have LIBUSB_CAP_SUPPORTS_DETACH_KERNEL_DRIVER 1727 * this function will return LIBUSB_ERROR_NOT_SUPPORTED, and libusbx will 1728 * continue as if this function was never called. 1729 * 1730 * \param dev a device handle 1731 * \param enable whether to enable or disable auto kernel driver detachment 1732 * 1733 * \returns LIBUSB_SUCCESS on success 1734 * \returns LIBUSB_ERROR_NOT_SUPPORTED on platforms where the functionality 1735 * is not available 1736 * \see libusb_claim_interface() 1737 * \see libusb_release_interface() 1738 * \see libusb_set_configuration() 1739 */ 1740 int API_EXPORTED libusb_set_auto_detach_kernel_driver( 1741 libusb_device_handle *dev, int enable) 1742 { 1743 if (!(usbi_backend->caps & USBI_CAP_SUPPORTS_DETACH_KERNEL_DRIVER)) 1744 return LIBUSB_ERROR_NOT_SUPPORTED; 1745 1746 dev->auto_detach_kernel_driver = enable; 1747 return LIBUSB_SUCCESS; 1748 } 1749 1750 /** \ingroup lib 1751 * Set log message verbosity. 1752 * 1753 * The default level is LIBUSB_LOG_LEVEL_NONE, which means no messages are ever 1754 * printed. If you choose to increase the message verbosity level, ensure 1755 * that your application does not close the stdout/stderr file descriptors. 1756 * 1757 * You are advised to use level LIBUSB_LOG_LEVEL_WARNING. libusbx is conservative 1758 * with its message logging and most of the time, will only log messages that 1759 * explain error conditions and other oddities. This will help you debug 1760 * your software. 1761 * 1762 * If the LIBUSB_DEBUG environment variable was set when libusbx was 1763 * initialized, this function does nothing: the message verbosity is fixed 1764 * to the value in the environment variable. 1765 * 1766 * If libusbx was compiled without any message logging, this function does 1767 * nothing: you'll never get any messages. 1768 * 1769 * If libusbx was compiled with verbose debug message logging, this function 1770 * does nothing: you'll always get messages from all levels. 1771 * 1772 * \param ctx the context to operate on, or NULL for the default context 1773 * \param level debug level to set 1774 */ 1775 void API_EXPORTED libusb_set_debug(libusb_context *ctx, int level) 1776 { 1777 USBI_GET_CONTEXT(ctx); 1778 if (!ctx->debug_fixed) 1779 ctx->debug = level; 1780 } 1781 1782 /** \ingroup lib 1783 * Initialize libusb. This function must be called before calling any other 1784 * libusbx function. 1785 * 1786 * If you do not provide an output location for a context pointer, a default 1787 * context will be created. If there was already a default context, it will 1788 * be reused (and nothing will be initialized/reinitialized). 1789 * 1790 * \param context Optional output location for context pointer. 1791 * Only valid on return code 0. 1792 * \returns 0 on success, or a LIBUSB_ERROR code on failure 1793 * \see contexts 1794 */ 1795 int API_EXPORTED libusb_init(libusb_context **context) 1796 { 1797 struct libusb_device *dev, *next; 1798 char *dbg = getenv("LIBUSB_DEBUG"); 1799 struct libusb_context *ctx; 1800 static int first_init = 1; 1801 int r = 0; 1802 1803 usbi_mutex_static_lock(&default_context_lock); 1804 1805 if (!timestamp_origin.tv_sec) { 1806 usbi_gettimeofday(×tamp_origin, NULL); 1807 } 1808 1809 if (!context && usbi_default_context) { 1810 usbi_dbg("reusing default context"); 1811 default_context_refcnt++; 1812 usbi_mutex_static_unlock(&default_context_lock); 1813 return 0; 1814 } 1815 1816 ctx = calloc(1, sizeof(*ctx)); 1817 if (!ctx) { 1818 r = LIBUSB_ERROR_NO_MEM; 1819 goto err_unlock; 1820 } 1821 1822 #ifdef ENABLE_DEBUG_LOGGING 1823 ctx->debug = LIBUSB_LOG_LEVEL_DEBUG; 1824 #endif 1825 1826 if (dbg) { 1827 ctx->debug = atoi(dbg); 1828 if (ctx->debug) 1829 ctx->debug_fixed = 1; 1830 } 1831 1832 /* default context should be initialized before calling usbi_dbg */ 1833 if (!usbi_default_context) { 1834 usbi_default_context = ctx; 1835 default_context_refcnt++; 1836 usbi_dbg("created default context"); 1837 } 1838 1839 usbi_dbg("libusbx v%d.%d.%d.%d", libusb_version_internal.major, libusb_version_internal.minor, 1840 libusb_version_internal.micro, libusb_version_internal.nano); 1841 1842 usbi_mutex_init(&ctx->usb_devs_lock, NULL); 1843 usbi_mutex_init(&ctx->open_devs_lock, NULL); 1844 usbi_mutex_init(&ctx->hotplug_cbs_lock, NULL); 1845 list_init(&ctx->usb_devs); 1846 list_init(&ctx->open_devs); 1847 list_init(&ctx->hotplug_cbs); 1848 1849 usbi_mutex_static_lock(&active_contexts_lock); 1850 if (first_init) { 1851 first_init = 0; 1852 list_init (&active_contexts_list); 1853 } 1854 list_add (&ctx->list, &active_contexts_list); 1855 usbi_mutex_static_unlock(&active_contexts_lock); 1856 1857 if (usbi_backend->init) { 1858 r = usbi_backend->init(ctx); 1859 if (r) 1860 goto err_free_ctx; 1861 } 1862 1863 r = usbi_io_init(ctx); 1864 if (r < 0) 1865 goto err_backend_exit; 1866 1867 usbi_mutex_static_unlock(&default_context_lock); 1868 1869 if (context) 1870 *context = ctx; 1871 1872 return 0; 1873 1874 err_backend_exit: 1875 if (usbi_backend->exit) 1876 usbi_backend->exit(); 1877 err_free_ctx: 1878 if (ctx == usbi_default_context) 1879 usbi_default_context = NULL; 1880 1881 usbi_mutex_static_lock(&active_contexts_lock); 1882 list_del (&ctx->list); 1883 usbi_mutex_static_unlock(&active_contexts_lock); 1884 1885 usbi_mutex_lock(&ctx->usb_devs_lock); 1886 list_for_each_entry_safe(dev, next, &ctx->usb_devs, list, struct libusb_device) { 1887 list_del(&dev->list); 1888 libusb_unref_device(dev); 1889 } 1890 usbi_mutex_unlock(&ctx->usb_devs_lock); 1891 1892 usbi_mutex_destroy(&ctx->open_devs_lock); 1893 usbi_mutex_destroy(&ctx->usb_devs_lock); 1894 usbi_mutex_destroy(&ctx->hotplug_cbs_lock); 1895 1896 free(ctx); 1897 err_unlock: 1898 usbi_mutex_static_unlock(&default_context_lock); 1899 return r; 1900 } 1901 1902 /** \ingroup lib 1903 * Deinitialize libusb. Should be called after closing all open devices and 1904 * before your application terminates. 1905 * \param ctx the context to deinitialize, or NULL for the default context 1906 */ 1907 void API_EXPORTED libusb_exit(struct libusb_context *ctx) 1908 { 1909 struct libusb_device *dev, *next; 1910 1911 usbi_dbg(""); 1912 USBI_GET_CONTEXT(ctx); 1913 1914 /* if working with default context, only actually do the deinitialization 1915 * if we're the last user */ 1916 usbi_mutex_static_lock(&default_context_lock); 1917 if (ctx == usbi_default_context) { 1918 if (--default_context_refcnt > 0) { 1919 usbi_dbg("not destroying default context"); 1920 usbi_mutex_static_unlock(&default_context_lock); 1921 return; 1922 } 1923 usbi_dbg("destroying default context"); 1924 usbi_default_context = NULL; 1925 } 1926 usbi_mutex_static_unlock(&default_context_lock); 1927 1928 usbi_mutex_static_lock(&active_contexts_lock); 1929 list_del (&ctx->list); 1930 usbi_mutex_static_unlock(&active_contexts_lock); 1931 1932 if (libusb_has_capability(LIBUSB_CAP_HAS_HOTPLUG)) { 1933 usbi_hotplug_deregister_all(ctx); 1934 usbi_mutex_lock(&ctx->usb_devs_lock); 1935 list_for_each_entry_safe(dev, next, &ctx->usb_devs, list, struct libusb_device) { 1936 list_del(&dev->list); 1937 libusb_unref_device(dev); 1938 } 1939 usbi_mutex_unlock(&ctx->usb_devs_lock); 1940 } 1941 1942 /* a few sanity checks. don't bother with locking because unless 1943 * there is an application bug, nobody will be accessing these. */ 1944 if (!list_empty(&ctx->usb_devs)) 1945 usbi_warn(ctx, "some libusb_devices were leaked"); 1946 if (!list_empty(&ctx->open_devs)) 1947 usbi_warn(ctx, "application left some devices open"); 1948 1949 usbi_io_exit(ctx); 1950 if (usbi_backend->exit) 1951 usbi_backend->exit(); 1952 1953 usbi_mutex_destroy(&ctx->open_devs_lock); 1954 usbi_mutex_destroy(&ctx->usb_devs_lock); 1955 usbi_mutex_destroy(&ctx->hotplug_cbs_lock); 1956 free(ctx); 1957 } 1958 1959 /** \ingroup misc 1960 * Check at runtime if the loaded library has a given capability. 1961 * This call should be performed after \ref libusb_init(), to ensure the 1962 * backend has updated its capability set. 1963 * 1964 * \param capability the \ref libusb_capability to check for 1965 * \returns nonzero if the running library has the capability, 0 otherwise 1966 */ 1967 int API_EXPORTED libusb_has_capability(uint32_t capability) 1968 { 1969 switch (capability) { 1970 case LIBUSB_CAP_HAS_CAPABILITY: 1971 return 1; 1972 case LIBUSB_CAP_HAS_HOTPLUG: 1973 return !(usbi_backend->get_device_list); 1974 case LIBUSB_CAP_HAS_HID_ACCESS: 1975 return (usbi_backend->caps & USBI_CAP_HAS_HID_ACCESS); 1976 case LIBUSB_CAP_SUPPORTS_DETACH_KERNEL_DRIVER: 1977 return (usbi_backend->caps & USBI_CAP_SUPPORTS_DETACH_KERNEL_DRIVER); 1978 } 1979 return 0; 1980 } 1981 1982 /* this is defined in libusbi.h if needed */ 1983 #ifdef LIBUSB_GETTIMEOFDAY_WIN32 1984 /* 1985 * gettimeofday 1986 * Implementation according to: 1987 * The Open Group Base Specifications Issue 6 1988 * IEEE Std 1003.1, 2004 Edition 1989 */ 1990 1991 /* 1992 * THIS SOFTWARE IS NOT COPYRIGHTED 1993 * 1994 * This source code is offered for use in the public domain. You may 1995 * use, modify or distribute it freely. 1996 * 1997 * This code is distributed in the hope that it will be useful but 1998 * WITHOUT ANY WARRANTY. ALL WARRANTIES, EXPRESS OR IMPLIED ARE HEREBY 1999 * DISCLAIMED. This includes but is not limited to warranties of 2000 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 2001 * 2002 * Contributed by: 2003 * Danny Smith <dannysmith (at) users.sourceforge.net> 2004 */ 2005 2006 /* Offset between 1/1/1601 and 1/1/1970 in 100 nanosec units */ 2007 #define _W32_FT_OFFSET (116444736000000000) 2008 2009 int usbi_gettimeofday(struct timeval *tp, void *tzp) 2010 { 2011 union { 2012 unsigned __int64 ns100; /* Time since 1 Jan 1601, in 100ns units */ 2013 FILETIME ft; 2014 } _now; 2015 UNUSED(tzp); 2016 2017 if(tp) { 2018 #if defined(OS_WINCE) 2019 SYSTEMTIME st; 2020 GetSystemTime(&st); 2021 SystemTimeToFileTime(&st, &_now.ft); 2022 #else 2023 GetSystemTimeAsFileTime (&_now.ft); 2024 #endif 2025 tp->tv_usec=(long)((_now.ns100 / 10) % 1000000 ); 2026 tp->tv_sec= (long)((_now.ns100 - _W32_FT_OFFSET) / 10000000); 2027 } 2028 /* Always return 0 as per Open Group Base Specifications Issue 6. 2029 Do not set errno on error. */ 2030 return 0; 2031 } 2032 #endif 2033 2034 static void usbi_log_str(struct libusb_context *ctx, 2035 enum libusb_log_level level, const char * str) 2036 { 2037 #if defined(USE_SYSTEM_LOGGING_FACILITY) 2038 #if defined(OS_WINDOWS) || defined(OS_WINCE) 2039 /* Windows CE only supports the Unicode version of OutputDebugString. */ 2040 WCHAR wbuf[USBI_MAX_LOG_LEN]; 2041 MultiByteToWideChar(CP_UTF8, 0, str, -1, wbuf, sizeof(wbuf)); 2042 OutputDebugStringW(wbuf); 2043 #elif defined(__ANDROID__) 2044 int priority = ANDROID_LOG_UNKNOWN; 2045 switch (level) { 2046 case LIBUSB_LOG_LEVEL_INFO: priority = ANDROID_LOG_INFO; break; 2047 case LIBUSB_LOG_LEVEL_WARNING: priority = ANDROID_LOG_WARN; break; 2048 case LIBUSB_LOG_LEVEL_ERROR: priority = ANDROID_LOG_ERROR; break; 2049 case LIBUSB_LOG_LEVEL_DEBUG: priority = ANDROID_LOG_DEBUG; break; 2050 } 2051 __android_log_write(priority, "libusb", str); 2052 #elif defined(HAVE_SYSLOG_FUNC) 2053 int syslog_level = LOG_INFO; 2054 switch (level) { 2055 case LIBUSB_LOG_LEVEL_INFO: syslog_level = LOG_INFO; break; 2056 case LIBUSB_LOG_LEVEL_WARNING: syslog_level = LOG_WARNING; break; 2057 case LIBUSB_LOG_LEVEL_ERROR: syslog_level = LOG_ERR; break; 2058 case LIBUSB_LOG_LEVEL_DEBUG: syslog_level = LOG_DEBUG; break; 2059 } 2060 syslog(syslog_level, "%s", str); 2061 #else /* All of gcc, Clang, XCode seem to use #warning */ 2062 #warning System logging is not supported on this platform. Logging to stderr will be used instead. 2063 fputs(str, stderr); 2064 #endif 2065 #else 2066 fputs(str, stderr); 2067 #endif /* USE_SYSTEM_LOGGING_FACILITY */ 2068 UNUSED(ctx); 2069 UNUSED(level); 2070 } 2071 2072 void usbi_log_v(struct libusb_context *ctx, enum libusb_log_level level, 2073 const char *function, const char *format, va_list args) 2074 { 2075 const char *prefix = ""; 2076 char buf[USBI_MAX_LOG_LEN]; 2077 struct timeval now; 2078 int global_debug, header_len, text_len; 2079 static int has_debug_header_been_displayed = 0; 2080 2081 #ifdef ENABLE_DEBUG_LOGGING 2082 global_debug = 1; 2083 UNUSED(ctx); 2084 #else 2085 USBI_GET_CONTEXT(ctx); 2086 if (ctx == NULL) 2087 return; 2088 global_debug = (ctx->debug == LIBUSB_LOG_LEVEL_DEBUG); 2089 if (!ctx->debug) 2090 return; 2091 if (level == LIBUSB_LOG_LEVEL_WARNING && ctx->debug < LIBUSB_LOG_LEVEL_WARNING) 2092 return; 2093 if (level == LIBUSB_LOG_LEVEL_INFO && ctx->debug < LIBUSB_LOG_LEVEL_INFO) 2094 return; 2095 if (level == LIBUSB_LOG_LEVEL_DEBUG && ctx->debug < LIBUSB_LOG_LEVEL_DEBUG) 2096 return; 2097 #endif 2098 2099 usbi_gettimeofday(&now, NULL); 2100 if ((global_debug) && (!has_debug_header_been_displayed)) { 2101 has_debug_header_been_displayed = 1; 2102 usbi_log_str(ctx, LIBUSB_LOG_LEVEL_DEBUG, "[timestamp] [threadID] facility level [function call] <message>\n"); 2103 usbi_log_str(ctx, LIBUSB_LOG_LEVEL_DEBUG, "--------------------------------------------------------------------------------\n"); 2104 } 2105 if (now.tv_usec < timestamp_origin.tv_usec) { 2106 now.tv_sec--; 2107 now.tv_usec += 1000000; 2108 } 2109 now.tv_sec -= timestamp_origin.tv_sec; 2110 now.tv_usec -= timestamp_origin.tv_usec; 2111 2112 switch (level) { 2113 case LIBUSB_LOG_LEVEL_INFO: 2114 prefix = "info"; 2115 break; 2116 case LIBUSB_LOG_LEVEL_WARNING: 2117 prefix = "warning"; 2118 break; 2119 case LIBUSB_LOG_LEVEL_ERROR: 2120 prefix = "error"; 2121 break; 2122 case LIBUSB_LOG_LEVEL_DEBUG: 2123 prefix = "debug"; 2124 break; 2125 case LIBUSB_LOG_LEVEL_NONE: 2126 return; 2127 default: 2128 prefix = "unknown"; 2129 break; 2130 } 2131 2132 if (global_debug) { 2133 header_len = snprintf(buf, sizeof(buf), 2134 "[%2d.%06d] [%08x] libusbx: %s [%s] ", 2135 (int)now.tv_sec, (int)now.tv_usec, usbi_get_tid(), prefix, function); 2136 } else { 2137 header_len = snprintf(buf, sizeof(buf), 2138 "libusbx: %s [%s] ", prefix, function); 2139 } 2140 2141 if (header_len < 0 || header_len >= sizeof(buf)) { 2142 /* Somehow snprintf failed to write to the buffer, 2143 * remove the header so something useful is output. */ 2144 header_len = 0; 2145 } 2146 /* Make sure buffer is NUL terminated */ 2147 buf[header_len] = '\0'; 2148 text_len = vsnprintf(buf + header_len, sizeof(buf) - header_len, 2149 format, args); 2150 if (text_len < 0 || text_len + header_len >= sizeof(buf)) { 2151 /* Truncated log output. On some platforms a -1 return value means 2152 * that the output was truncated. */ 2153 text_len = sizeof(buf) - header_len; 2154 } 2155 if (header_len + text_len + sizeof(USBI_LOG_LINE_END) >= sizeof(buf)) { 2156 /* Need to truncate the text slightly to fit on the terminator. */ 2157 text_len -= (header_len + text_len + sizeof(USBI_LOG_LINE_END)) - sizeof(buf); 2158 } 2159 strcpy(buf + header_len + text_len, USBI_LOG_LINE_END); 2160 2161 usbi_log_str(ctx, level, buf); 2162 } 2163 2164 void usbi_log(struct libusb_context *ctx, enum libusb_log_level level, 2165 const char *function, const char *format, ...) 2166 { 2167 va_list args; 2168 2169 va_start (args, format); 2170 usbi_log_v(ctx, level, function, format, args); 2171 va_end (args); 2172 } 2173 2174 /** \ingroup misc 2175 * Returns a constant NULL-terminated string with the ASCII name of a libusbx 2176 * error or transfer status code. The caller must not free() the returned 2177 * string. 2178 * 2179 * \param error_code The \ref libusb_error or libusb_transfer_status code to 2180 * return the name of. 2181 * \returns The error name, or the string **UNKNOWN** if the value of 2182 * error_code is not a known error / status code. 2183 */ 2184 DEFAULT_VISIBILITY const char * LIBUSB_CALL libusb_error_name(int error_code) 2185 { 2186 switch (error_code) { 2187 case LIBUSB_ERROR_IO: 2188 return "LIBUSB_ERROR_IO"; 2189 case LIBUSB_ERROR_INVALID_PARAM: 2190 return "LIBUSB_ERROR_INVALID_PARAM"; 2191 case LIBUSB_ERROR_ACCESS: 2192 return "LIBUSB_ERROR_ACCESS"; 2193 case LIBUSB_ERROR_NO_DEVICE: 2194 return "LIBUSB_ERROR_NO_DEVICE"; 2195 case LIBUSB_ERROR_NOT_FOUND: 2196 return "LIBUSB_ERROR_NOT_FOUND"; 2197 case LIBUSB_ERROR_BUSY: 2198 return "LIBUSB_ERROR_BUSY"; 2199 case LIBUSB_ERROR_TIMEOUT: 2200 return "LIBUSB_ERROR_TIMEOUT"; 2201 case LIBUSB_ERROR_OVERFLOW: 2202 return "LIBUSB_ERROR_OVERFLOW"; 2203 case LIBUSB_ERROR_PIPE: 2204 return "LIBUSB_ERROR_PIPE"; 2205 case LIBUSB_ERROR_INTERRUPTED: 2206 return "LIBUSB_ERROR_INTERRUPTED"; 2207 case LIBUSB_ERROR_NO_MEM: 2208 return "LIBUSB_ERROR_NO_MEM"; 2209 case LIBUSB_ERROR_NOT_SUPPORTED: 2210 return "LIBUSB_ERROR_NOT_SUPPORTED"; 2211 case LIBUSB_ERROR_OTHER: 2212 return "LIBUSB_ERROR_OTHER"; 2213 2214 case LIBUSB_TRANSFER_ERROR: 2215 return "LIBUSB_TRANSFER_ERROR"; 2216 case LIBUSB_TRANSFER_TIMED_OUT: 2217 return "LIBUSB_TRANSFER_TIMED_OUT"; 2218 case LIBUSB_TRANSFER_CANCELLED: 2219 return "LIBUSB_TRANSFER_CANCELLED"; 2220 case LIBUSB_TRANSFER_STALL: 2221 return "LIBUSB_TRANSFER_STALL"; 2222 case LIBUSB_TRANSFER_NO_DEVICE: 2223 return "LIBUSB_TRANSFER_NO_DEVICE"; 2224 case LIBUSB_TRANSFER_OVERFLOW: 2225 return "LIBUSB_TRANSFER_OVERFLOW"; 2226 2227 case 0: 2228 return "LIBUSB_SUCCESS / LIBUSB_TRANSFER_COMPLETED"; 2229 default: 2230 return "**UNKNOWN**"; 2231 } 2232 } 2233 2234 /** \ingroup misc 2235 * Returns a pointer to const struct libusb_version with the version 2236 * (major, minor, micro, nano and rc) of the running library. 2237 */ 2238 DEFAULT_VISIBILITY 2239 const struct libusb_version * LIBUSB_CALL libusb_get_version(void) 2240 { 2241 return &libusb_version_internal; 2242 } 2243
