diff options
Diffstat (limited to 'hardware/src/libusb/core.c')
| -rw-r--r-- | hardware/src/libusb/core.c | 2737 |
1 files changed, 2737 insertions, 0 deletions
diff --git a/hardware/src/libusb/core.c b/hardware/src/libusb/core.c new file mode 100644 index 0000000..7893ac2 --- /dev/null +++ b/hardware/src/libusb/core.c @@ -0,0 +1,2737 @@ +/* -*- Mode: C; indent-tabs-mode:t ; c-basic-offset:8 -*- */ +/* + * Core functions for libusb + * Copyright © 2012-2013 Nathan Hjelm <hjelmn@cs.unm.edu> + * Copyright © 2007-2008 Daniel Drake <dsd@gentoo.org> + * Copyright © 2001 Johannes Erdfelt <johannes@erdfelt.com> + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include "libusbi.h" +#include "version.h" + +#ifdef __ANDROID__ +#include <android/log.h> +#endif +#include <stdio.h> +#include <string.h> +#ifdef HAVE_SYSLOG +#include <syslog.h> +#endif + +static const struct libusb_version libusb_version_internal = + { LIBUSB_MAJOR, LIBUSB_MINOR, LIBUSB_MICRO, LIBUSB_NANO, + LIBUSB_RC, "http://libusb.info" }; +static struct timespec timestamp_origin; +#if defined(ENABLE_LOGGING) && !defined(USE_SYSTEM_LOGGING_FACILITY) +static libusb_log_cb log_handler; +#endif + +struct libusb_context *usbi_default_context; +static int default_context_refcnt; +static usbi_mutex_static_t default_context_lock = USBI_MUTEX_INITIALIZER; +static struct usbi_option default_context_options[LIBUSB_OPTION_MAX]; + + +usbi_mutex_static_t active_contexts_lock = USBI_MUTEX_INITIALIZER; +struct list_head active_contexts_list; + +/** + * \mainpage libusb-1.0 API Reference + * + * \section intro Introduction + * + * libusb is an open source library that allows you to communicate with USB + * devices from user space. For more info, see the + * <a href="http://libusb.info">libusb homepage</a>. + * + * This documentation is aimed at application developers wishing to + * communicate with USB peripherals from their own software. After reviewing + * this documentation, feedback and questions can be sent to the + * <a href="http://mailing-list.libusb.info">libusb-devel mailing list</a>. + * + * This documentation assumes knowledge of how to operate USB devices from + * a software standpoint (descriptors, configurations, interfaces, endpoints, + * control/bulk/interrupt/isochronous transfers, etc). Full information + * can be found in the <a href="http://www.usb.org/developers/docs/">USB 3.0 + * Specification</a> which is available for free download. You can probably + * find less verbose introductions by searching the web. + * + * \section API Application Programming Interface (API) + * + * See the \ref libusb_api page for a complete list of the libusb functions. + * + * \section features Library features + * + * - All transfer types supported (control/bulk/interrupt/isochronous) + * - 2 transfer interfaces: + * -# Synchronous (simple) + * -# Asynchronous (more complicated, but more powerful) + * - Thread safe (although the asynchronous interface means that you + * usually won't need to thread) + * - Lightweight with lean API + * - Compatible with libusb-0.1 through the libusb-compat-0.1 translation layer + * - Hotplug support (on some platforms). See \ref libusb_hotplug. + * + * \section gettingstarted Getting Started + * + * To begin reading the API documentation, start with the Modules page which + * links to the different categories of libusb's functionality. + * + * One decision you will have to make is whether to use the synchronous + * or the asynchronous data transfer interface. The \ref libusb_io documentation + * provides some insight into this topic. + * + * Some example programs can be found in the libusb source distribution under + * the "examples" subdirectory. The libusb homepage includes a list of + * real-life project examples which use libusb. + * + * \section errorhandling Error handling + * + * libusb functions typically return 0 on success or a negative error code + * on failure. These negative error codes relate to LIBUSB_ERROR constants + * which are listed on the \ref libusb_misc "miscellaneous" documentation page. + * + * \section msglog Debug message logging + * + * libusb uses stderr for all logging. By default, logging is set to NONE, + * which means that no output will be produced. However, unless the library + * has been compiled with logging disabled, then any application calls to + * libusb_set_option(ctx, LIBUSB_OPTION_LOG_LEVEL, level), or the setting of the + * environmental variable LIBUSB_DEBUG outside of the application, can result + * in logging being produced. Your application should therefore not close + * stderr, but instead direct it to the null device if its output is + * undesirable. + * + * The libusb_set_option(ctx, LIBUSB_OPTION_LOG_LEVEL, level) function can be + * used to enable logging of certain messages. Under standard configuration, + * libusb doesn't really log much so you are advised to use this function + * to enable all error/warning/ informational messages. It will help debug + * problems with your software. + * + * The logged messages are unstructured. There is no one-to-one correspondence + * between messages being logged and success or failure return codes from + * libusb functions. There is no format to the messages, so you should not + * try to capture or parse them. They are not and will not be localized. + * These messages are not intended to being passed to your application user; + * instead, you should interpret the error codes returned from libusb functions + * and provide appropriate notification to the user. The messages are simply + * there to aid you as a programmer, and if you're confused because you're + * getting a strange error code from a libusb function, enabling message + * logging may give you a suitable explanation. + * + * The LIBUSB_DEBUG environment variable can be used to enable message logging + * at run-time. This environment variable should be set to a log level number, + * which is interpreted the same as the + * libusb_set_option(ctx, LIBUSB_OPTION_LOG_LEVEL, level) parameter. When this + * environment variable is set, the message logging verbosity level is fixed + * and libusb_set_option(ctx, LIBUSB_OPTION_LOG_LEVEL, level) effectively does + * nothing. + * + * libusb can be compiled without any logging functions, useful for embedded + * systems. In this case, libusb_set_option(ctx, LIBUSB_OPTION_LOG_LEVEL, level) + * and the LIBUSB_DEBUG environment variable have no effects. + * + * libusb can also be compiled with verbose debugging messages always. When + * the library is compiled in this way, all messages of all verbosities are + * always logged. libusb_set_option(ctx, LIBUSB_OPTION_LOG_LEVEL, level) and + * the LIBUSB_DEBUG environment variable have no effects. + * + * \section remarks Other remarks + * + * libusb does have imperfections. The \ref libusb_caveats "caveats" page attempts + * to document these. + */ + +/** + * \page libusb_caveats Caveats + * + * \section threadsafety Thread safety + * + * libusb is designed to be completely thread-safe, but as with any API it + * cannot prevent a user from sabotaging themselves, either intentionally or + * otherwise. + * + * Observe the following general guidelines: + * + * - Calls to functions that release a resource (e.g. libusb_close(), + * libusb_free_config_descriptor()) should not be called concurrently on + * the same resource. This is no different than concurrently calling free() + * on the same allocated pointer. + * - Each individual \ref libusb_transfer should be prepared by a single + * thread. In other words, no two threads should ever be concurrently + * filling out the fields of a \ref libusb_transfer. You can liken this to + * calling sprintf() with the same destination buffer from multiple threads. + * The results will likely not be what you want unless the input parameters + * are all the same, but its best to avoid this situation entirely. + * - Both the \ref libusb_transfer structure and its associated data buffer + * should not be accessed between the time the transfer is submitted and the + * time the completion callback is invoked. You can think of "ownership" of + * these things as being transferred to libusb while the transfer is active. + * - The various "setter" functions (e.g. libusb_set_log_cb(), + * libusb_set_pollfd_notifiers()) should not be called concurrently on the + * resource. Though doing so will not lead to any undefined behavior, it + * will likely produce results that the application does not expect. + * + * Rules for multiple threads and asynchronous I/O are detailed + * \ref libusb_mtasync "here". + * + * \section fork Fork considerations + * + * libusb is <em>not</em> designed to work across fork() calls. Depending on + * the platform, there may be resources in the parent process that are not + * available to the child (e.g. the hotplug monitor thread on Linux). In + * addition, since the parent and child will share libusb's internal file + * descriptors, using libusb in any way from the child could cause the parent + * process's \ref libusb_context to get into an inconsistent state. + * + * On Linux, libusb's file descriptors will be marked as CLOEXEC, which means + * that it is safe to fork() and exec() without worrying about the child + * process needing to clean up state or having access to these file descriptors. + * Other platforms may not be so forgiving, so consider yourself warned! + * + * \section devresets Device resets + * + * The libusb_reset_device() function allows you to reset a device. If your + * program has to call such a function, it should obviously be aware that + * the reset will cause device state to change (e.g. register values may be + * reset). + * + * The problem is that any other program could reset the device your program + * is working with, at any time. libusb does not offer a mechanism to inform + * you when this has happened, so if someone else resets your device it will + * not be clear to your own program why the device state has changed. + * + * Ultimately, this is a limitation of writing drivers in user space. + * Separation from the USB stack in the underlying kernel makes it difficult + * for the operating system to deliver such notifications to your program. + * The Linux kernel USB stack allows such reset notifications to be delivered + * to in-kernel USB drivers, but it is not clear how such notifications could + * be delivered to second-class drivers that live in user space. + * + * \section blockonly Blocking-only functionality + * + * The functionality listed below is only available through synchronous, + * blocking functions. There are no asynchronous/non-blocking alternatives, + * and no clear ways of implementing these. + * + * - Configuration activation (libusb_set_configuration()) + * - Interface/alternate setting activation (libusb_set_interface_alt_setting()) + * - Releasing of interfaces (libusb_release_interface()) + * - Clearing of halt/stall condition (libusb_clear_halt()) + * - Device resets (libusb_reset_device()) + * + * \section configsel Configuration selection and handling + * + * When libusb presents a device handle to an application, there is a chance + * that the corresponding device may be in unconfigured state. For devices + * with multiple configurations, there is also a chance that the configuration + * currently selected is not the one that the application wants to use. + * + * The obvious solution is to add a call to libusb_set_configuration() early + * on during your device initialization routines, but there are caveats to + * be aware of: + * -# If the device is already in the desired configuration, calling + * libusb_set_configuration() using the same configuration value will cause + * a lightweight device reset. This may not be desirable behaviour. + * -# In the case where the desired configuration is already active, libusb + * may not even be able to perform a lightweight device reset. For example, + * take my USB keyboard with fingerprint reader: I'm interested in driving + * the fingerprint reader interface through libusb, but the kernel's + * USB-HID driver will almost always have claimed the keyboard interface. + * Because the kernel has claimed an interface, it is not even possible to + * perform the lightweight device reset, so libusb_set_configuration() will + * fail. (Luckily the device in question only has a single configuration.) + * -# libusb will be unable to set a configuration if other programs or + * drivers have claimed interfaces. In particular, this means that kernel + * drivers must be detached from all the interfaces before + * libusb_set_configuration() may succeed. + * + * One solution to some of the above problems is to consider the currently + * active configuration. If the configuration we want is already active, then + * we don't have to select any configuration: +\code +cfg = -1; +libusb_get_configuration(dev, &cfg); +if (cfg != desired) + libusb_set_configuration(dev, desired); +\endcode + * + * This is probably suitable for most scenarios, but is inherently racy: + * another application or driver may change the selected configuration + * <em>after</em> the libusb_get_configuration() call. + * + * Even in cases where libusb_set_configuration() succeeds, consider that other + * applications or drivers may change configuration after your application + * calls libusb_set_configuration(). + * + * One possible way to lock your device into a specific configuration is as + * follows: + * -# Set the desired configuration (or use the logic above to realise that + * it is already in the desired configuration) + * -# Claim the interface that you wish to use + * -# Check that the currently active configuration is the one that you want + * to use. + * + * The above method works because once an interface is claimed, no application + * or driver is able to select another configuration. + * + * \section earlycomp Early transfer completion + * + * NOTE: This section is currently Linux-centric. I am not sure if any of these + * considerations apply to Darwin or other platforms. + * + * When a transfer completes early (i.e. when less data is received/sent in + * any one packet than the transfer buffer allows for) then libusb is designed + * to terminate the transfer immediately, not transferring or receiving any + * more data unless other transfers have been queued by the user. + * + * On legacy platforms, libusb is unable to do this in all situations. After + * the incomplete packet occurs, "surplus" data may be transferred. For recent + * versions of libusb, this information is kept (the data length of the + * transfer is updated) and, for device-to-host transfers, any surplus data was + * added to the buffer. Still, this is not a nice solution because it loses the + * information about the end of the short packet, and the user probably wanted + * that surplus data to arrive in the next logical transfer. + * + * \section zlp Zero length packets + * + * - libusb is able to send a packet of zero length to an endpoint simply by + * submitting a transfer of zero length. + * - The \ref libusb_transfer_flags::LIBUSB_TRANSFER_ADD_ZERO_PACKET + * "LIBUSB_TRANSFER_ADD_ZERO_PACKET" flag is currently supported on Linux, + * Darwin and Windows (WinUSB). + */ + +/** + * \page libusb_contexts Contexts + * + * It is possible that libusb may be used simultaneously from two independent + * libraries linked into the same executable. For example, if your application + * has a plugin-like system which allows the user to dynamically load a range + * of modules into your program, it is feasible that two independently + * developed modules may both use libusb. + * + * libusb is written to allow for these multiple user scenarios. The two + * "instances" of libusb will not interfere: libusb_set_option() calls + * from one user will not affect the same settings for other users, other + * users can continue using libusb after one of them calls libusb_exit(), etc. + * + * This is made possible through libusb's <em>context</em> concept. When you + * call libusb_init(), you are (optionally) given a context. You can then pass + * this context pointer back into future libusb functions. + * + * In order to keep things simple for more simplistic applications, it is + * legal to pass NULL to all functions requiring a context pointer (as long as + * you're sure no other code will attempt to use libusb from the same process). + * When you pass NULL, the default context will be used. The default context + * is created the first time a process calls libusb_init() when no other + * context is alive. Contexts are destroyed during libusb_exit(). + * + * The default context is reference-counted and can be shared. That means that + * if libusb_init(NULL) is called twice within the same process, the two + * users end up sharing the same context. The deinitialization and freeing of + * the default context will only happen when the last user calls libusb_exit(). + * In other words, the default context is created and initialized when its + * reference count goes from 0 to 1, and is deinitialized and destroyed when + * its reference count goes from 1 to 0. + * + * You may be wondering why only a subset of libusb functions require a + * context pointer in their function definition. Internally, libusb stores + * context pointers in other objects (e.g. libusb_device instances) and hence + * can infer the context from those objects. + */ + + /** + * \page libusb_api Application Programming Interface + * + * This is the complete list of libusb functions, structures and + * enumerations in alphabetical order. + * + * \section Functions + * - libusb_alloc_streams() + * - libusb_alloc_transfer() + * - libusb_attach_kernel_driver() + * - libusb_bulk_transfer() + * - libusb_cancel_transfer() + * - libusb_claim_interface() + * - libusb_clear_halt() + * - libusb_close() + * - libusb_control_transfer() + * - libusb_control_transfer_get_data() + * - libusb_control_transfer_get_setup() + * - libusb_cpu_to_le16() + * - libusb_detach_kernel_driver() + * - libusb_dev_mem_alloc() + * - libusb_dev_mem_free() + * - libusb_error_name() + * - libusb_event_handler_active() + * - libusb_event_handling_ok() + * - libusb_exit() + * - libusb_fill_bulk_stream_transfer() + * - libusb_fill_bulk_transfer() + * - libusb_fill_control_setup() + * - libusb_fill_control_transfer() + * - libusb_fill_interrupt_transfer() + * - libusb_fill_iso_transfer() + * - libusb_free_bos_descriptor() + * - libusb_free_config_descriptor() + * - libusb_free_container_id_descriptor() + * - libusb_free_device_list() + * - libusb_free_pollfds() + * - libusb_free_ss_endpoint_companion_descriptor() + * - libusb_free_ss_usb_device_capability_descriptor() + * - libusb_free_streams() + * - libusb_free_transfer() + * - libusb_free_usb_2_0_extension_descriptor() + * - libusb_get_active_config_descriptor() + * - libusb_get_bos_descriptor() + * - libusb_get_bus_number() + * - libusb_get_config_descriptor() + * - libusb_get_config_descriptor_by_value() + * - libusb_get_configuration() + * - libusb_get_container_id_descriptor() + * - libusb_get_descriptor() + * - libusb_get_device() + * - libusb_get_device_address() + * - libusb_get_device_descriptor() + * - libusb_get_device_list() + * - libusb_get_device_speed() + * - libusb_get_iso_packet_buffer() + * - libusb_get_iso_packet_buffer_simple() + * - libusb_get_max_iso_packet_size() + * - libusb_get_max_packet_size() + * - libusb_get_next_timeout() + * - libusb_get_parent() + * - libusb_get_pollfds() + * - libusb_get_port_number() + * - libusb_get_port_numbers() + * - libusb_get_port_path() + * - libusb_get_ss_endpoint_companion_descriptor() + * - libusb_get_ss_usb_device_capability_descriptor() + * - libusb_get_string_descriptor() + * - libusb_get_string_descriptor_ascii() + * - libusb_get_usb_2_0_extension_descriptor() + * - libusb_get_version() + * - libusb_handle_events() + * - libusb_handle_events_completed() + * - libusb_handle_events_locked() + * - libusb_handle_events_timeout() + * - libusb_handle_events_timeout_completed() + * - libusb_has_capability() + * - libusb_hotplug_deregister_callback() + * - libusb_hotplug_register_callback() + * - libusb_init() + * - libusb_interrupt_event_handler() + * - libusb_interrupt_transfer() + * - libusb_kernel_driver_active() + * - libusb_lock_events() + * - libusb_lock_event_waiters() + * - libusb_open() + * - libusb_open_device_with_vid_pid() + * - libusb_pollfds_handle_timeouts() + * - libusb_ref_device() + * - libusb_release_interface() + * - libusb_reset_device() + * - libusb_set_auto_detach_kernel_driver() + * - libusb_set_configuration() + * - libusb_set_debug() + * - libusb_set_log_cb() + * - libusb_set_interface_alt_setting() + * - libusb_set_iso_packet_lengths() + * - libusb_set_option() + * - libusb_setlocale() + * - libusb_set_pollfd_notifiers() + * - libusb_strerror() + * - libusb_submit_transfer() + * - libusb_transfer_get_stream_id() + * - libusb_transfer_set_stream_id() + * - libusb_try_lock_events() + * - libusb_unlock_events() + * - libusb_unlock_event_waiters() + * - libusb_unref_device() + * - libusb_wait_for_event() + * - libusb_wrap_sys_device() + * + * \section Structures + * - libusb_bos_descriptor + * - libusb_bos_dev_capability_descriptor + * - libusb_config_descriptor + * - libusb_container_id_descriptor + * - \ref libusb_context + * - libusb_control_setup + * - \ref libusb_device + * - libusb_device_descriptor + * - \ref libusb_device_handle + * - libusb_endpoint_descriptor + * - libusb_interface + * - libusb_interface_descriptor + * - libusb_iso_packet_descriptor + * - libusb_pollfd + * - libusb_ss_endpoint_companion_descriptor + * - libusb_ss_usb_device_capability_descriptor + * - libusb_transfer + * - libusb_usb_2_0_extension_descriptor + * - libusb_version + * + * \section Enums + * - \ref libusb_bos_type + * - \ref libusb_capability + * - \ref libusb_class_code + * - \ref libusb_descriptor_type + * - \ref libusb_endpoint_direction + * - \ref libusb_endpoint_transfer_type + * - \ref libusb_error + * - \ref libusb_iso_sync_type + * - \ref libusb_iso_usage_type + * - \ref libusb_log_level + * - \ref libusb_option + * - \ref libusb_request_recipient + * - \ref libusb_request_type + * - \ref libusb_speed + * - \ref libusb_ss_usb_device_capability_attributes + * - \ref libusb_standard_request + * - \ref libusb_supported_speed + * - \ref libusb_transfer_flags + * - \ref libusb_transfer_status + * - \ref libusb_transfer_type + * - \ref libusb_usb_2_0_extension_attributes + */ + +/** + * @defgroup libusb_lib Library initialization/deinitialization + * This page details how to initialize and deinitialize libusb. Initialization + * must be performed before using any libusb functionality, and similarly you + * must not call any libusb functions after deinitialization. + */ + +/** + * @defgroup libusb_dev Device handling and enumeration + * The functionality documented below is designed to help with the following + * operations: + * - Enumerating the USB devices currently attached to the system + * - Choosing a device to operate from your software + * - Opening and closing the chosen device + * + * \section nutshell In a nutshell... + * + * The description below really makes things sound more complicated than they + * actually are. The following sequence of function calls will be suitable + * for almost all scenarios and does not require you to have such a deep + * understanding of the resource management issues: + * \code +// discover devices +libusb_device **list; +libusb_device *found = NULL; +ssize_t cnt = libusb_get_device_list(NULL, &list); +ssize_t i = 0; +int err = 0; +if (cnt < 0) + error(); + +for (i = 0; i < cnt; i++) { + libusb_device *device = list[i]; + if (is_interesting(device)) { + found = device; + break; + } +} + +if (found) { + libusb_device_handle *handle; + + err = libusb_open(found, &handle); + if (err) + error(); + // etc +} + +libusb_free_device_list(list, 1); +\endcode + * + * The two important points: + * - You asked libusb_free_device_list() to unreference the devices (2nd + * parameter) + * - You opened the device before freeing the list and unreferencing the + * devices + * + * If you ended up with a handle, you can now proceed to perform I/O on the + * device. + * + * \section devshandles Devices and device handles + * libusb has a concept of a USB device, represented by the + * \ref libusb_device opaque type. A device represents a USB device that + * is currently or was previously connected to the system. Using a reference + * to a device, you can determine certain information about the device (e.g. + * you can read the descriptor data). + * + * The libusb_get_device_list() function can be used to obtain a list of + * devices currently connected to the system. This is known as device + * discovery. Devices can also be discovered with the hotplug mechanism, + * whereby a callback function registered with libusb_hotplug_register_callback() + * will be called when a device of interest is connected or disconnected. + * + * Just because you have a reference to a device does not mean it is + * necessarily usable. The device may have been unplugged, you may not have + * permission to operate such device, or another program or driver may be + * using the device. + * + * When you've found a device that you'd like to operate, you must ask + * libusb to open the device using the libusb_open() function. Assuming + * success, libusb then returns you a <em>device handle</em> + * (a \ref libusb_device_handle pointer). All "real" I/O operations then + * operate on the handle rather than the original device pointer. + * + * \section devref Device discovery and reference counting + * + * Device discovery (i.e. calling libusb_get_device_list()) returns a + * freshly-allocated list of devices. The list itself must be freed when + * you are done with it. libusb also needs to know when it is OK to free + * the contents of the list - the devices themselves. + * + * To handle these issues, libusb provides you with two separate items: + * - A function to free the list itself + * - A reference counting system for the devices inside + * + * New devices presented by the libusb_get_device_list() function all have a + * reference count of 1. You can increase and decrease reference count using + * libusb_ref_device() and libusb_unref_device(). A device is destroyed when + * its reference count reaches 0. + * + * With the above information in mind, the process of opening a device can + * be viewed as follows: + * -# Discover devices using libusb_get_device_list() or libusb_hotplug_register_callback(). + * -# Choose the device that you want to operate, and call libusb_open(). + * -# Unref all devices in the discovered device list. + * -# Free the discovered device list. + * + * The order is important - you must not unreference the device before + * attempting to open it, because unreferencing it may destroy the device. + * + * For convenience, the libusb_free_device_list() function includes a + * parameter to optionally unreference all the devices in the list before + * freeing the list itself. This combines steps 3 and 4 above. + * + * As an implementation detail, libusb_open() actually adds a reference to + * the device in question. This is because the device remains available + * through the handle via libusb_get_device(). The reference is deleted during + * libusb_close(). + */ + +/** @defgroup libusb_misc Miscellaneous */ + +/* we traverse usbfs without knowing how many devices we are going to find. + * so we create this discovered_devs model which is similar to a linked-list + * which grows when required. it can be freed once discovery has completed, + * eliminating the need for a list node in the libusb_device structure + * itself. */ +#define DISCOVERED_DEVICES_SIZE_STEP 16 + +static struct discovered_devs *discovered_devs_alloc(void) +{ + struct discovered_devs *ret = + malloc(sizeof(*ret) + (sizeof(void *) * DISCOVERED_DEVICES_SIZE_STEP)); + + if (ret) { + ret->len = 0; + ret->capacity = DISCOVERED_DEVICES_SIZE_STEP; + } + return ret; +} + +static void discovered_devs_free(struct discovered_devs *discdevs) +{ + size_t i; + + for (i = 0; i < discdevs->len; i++) + libusb_unref_device(discdevs->devices[i]); + + free(discdevs); +} + +/* append a device to the discovered devices collection. may realloc itself, + * returning new discdevs. returns NULL on realloc failure. */ +struct discovered_devs *discovered_devs_append( + struct discovered_devs *discdevs, struct libusb_device *dev) +{ + size_t len = discdevs->len; + size_t capacity; + struct discovered_devs *new_discdevs; + + /* if there is space, just append the device */ + if (len < discdevs->capacity) { + discdevs->devices[len] = libusb_ref_device(dev); + discdevs->len++; + return discdevs; + } + + /* exceeded capacity, need to grow */ + usbi_dbg(DEVICE_CTX(dev), "need to increase capacity"); + capacity = discdevs->capacity + DISCOVERED_DEVICES_SIZE_STEP; + /* can't use usbi_reallocf here because in failure cases it would + * free the existing discdevs without unreferencing its devices. */ + new_discdevs = realloc(discdevs, + sizeof(*discdevs) + (sizeof(void *) * capacity)); + if (!new_discdevs) { + discovered_devs_free(discdevs); + return NULL; + } + + discdevs = new_discdevs; + discdevs->capacity = capacity; + discdevs->devices[len] = libusb_ref_device(dev); + discdevs->len++; + + return discdevs; +} + +/* Allocate a new device with a specific session ID. The returned device has + * a reference count of 1. */ +struct libusb_device *usbi_alloc_device(struct libusb_context *ctx, + unsigned long session_id) +{ + size_t priv_size = usbi_backend.device_priv_size; + struct libusb_device *dev = calloc(1, PTR_ALIGN(sizeof(*dev)) + priv_size); + + if (!dev) + return NULL; + + usbi_atomic_store(&dev->refcnt, 1); + + dev->ctx = ctx; + dev->session_data = session_id; + dev->speed = LIBUSB_SPEED_UNKNOWN; + + if (!libusb_has_capability(LIBUSB_CAP_HAS_HOTPLUG)) + usbi_connect_device(dev); + + return dev; +} + +void usbi_connect_device(struct libusb_device *dev) +{ + struct libusb_context *ctx = DEVICE_CTX(dev); + + usbi_atomic_store(&dev->attached, 1); + + usbi_mutex_lock(&dev->ctx->usb_devs_lock); + list_add(&dev->list, &dev->ctx->usb_devs); + usbi_mutex_unlock(&dev->ctx->usb_devs_lock); + + usbi_hotplug_notification(ctx, dev, LIBUSB_HOTPLUG_EVENT_DEVICE_ARRIVED); +} + +void usbi_disconnect_device(struct libusb_device *dev) +{ + struct libusb_context *ctx = DEVICE_CTX(dev); + + usbi_atomic_store(&dev->attached, 0); + + usbi_mutex_lock(&ctx->usb_devs_lock); + list_del(&dev->list); + usbi_mutex_unlock(&ctx->usb_devs_lock); + + usbi_hotplug_notification(ctx, dev, LIBUSB_HOTPLUG_EVENT_DEVICE_LEFT); +} + +/* Perform some final sanity checks on a newly discovered device. If this + * function fails (negative return code), the device should not be added + * to the discovered device list. */ +int usbi_sanitize_device(struct libusb_device *dev) +{ + uint8_t num_configurations; + + if (dev->device_descriptor.bLength != LIBUSB_DT_DEVICE_SIZE || + dev->device_descriptor.bDescriptorType != LIBUSB_DT_DEVICE) { + usbi_err(DEVICE_CTX(dev), "invalid device descriptor"); + return LIBUSB_ERROR_IO; + } + + num_configurations = dev->device_descriptor.bNumConfigurations; + if (num_configurations > USB_MAXCONFIG) { + usbi_err(DEVICE_CTX(dev), "too many configurations"); + return LIBUSB_ERROR_IO; + } else if (0 == num_configurations) { + usbi_dbg(DEVICE_CTX(dev), "zero configurations, maybe an unauthorized device"); + } + + return 0; +} + +/* Examine libusb's internal list of known devices, looking for one with + * a specific session ID. Returns the matching device if it was found, and + * NULL otherwise. */ +struct libusb_device *usbi_get_device_by_session_id(struct libusb_context *ctx, + unsigned long session_id) +{ + struct libusb_device *dev; + struct libusb_device *ret = NULL; + + usbi_mutex_lock(&ctx->usb_devs_lock); + for_each_device(ctx, dev) { + if (dev->session_data == session_id) { + ret = libusb_ref_device(dev); + break; + } + } + usbi_mutex_unlock(&ctx->usb_devs_lock); + + return ret; +} + +/** @ingroup libusb_dev + * Returns a list of USB devices currently attached to the system. This is + * your entry point into finding a USB device to operate. + * + * You are expected to unreference all the devices when you are done with + * them, and then free the list with libusb_free_device_list(). Note that + * libusb_free_device_list() can unref all the devices for you. Be careful + * not to unreference a device you are about to open until after you have + * opened it. + * + * This return value of this function indicates the number of devices in + * the resultant list. The list is actually one element larger, as it is + * NULL-terminated. + * + * \param ctx the context to operate on, or NULL for the default context + * \param list output location for a list of devices. Must be later freed with + * libusb_free_device_list(). + * \returns the number of devices in the outputted list, or any + * \ref libusb_error according to errors encountered by the backend. + */ +ssize_t API_EXPORTED libusb_get_device_list(libusb_context *ctx, + libusb_device ***list) +{ + struct discovered_devs *discdevs = discovered_devs_alloc(); + struct libusb_device **ret; + int r = 0; + ssize_t i, len; + + usbi_dbg(ctx, " "); + + if (!discdevs) + return LIBUSB_ERROR_NO_MEM; + + ctx = usbi_get_context(ctx); + + if (libusb_has_capability(LIBUSB_CAP_HAS_HOTPLUG)) { + /* backend provides hotplug support */ + struct libusb_device *dev; + + if (usbi_backend.hotplug_poll) + usbi_backend.hotplug_poll(); + + usbi_mutex_lock(&ctx->usb_devs_lock); + for_each_device(ctx, dev) { + discdevs = discovered_devs_append(discdevs, dev); + + if (!discdevs) { + r = LIBUSB_ERROR_NO_MEM; + break; + } + } + usbi_mutex_unlock(&ctx->usb_devs_lock); + } else { + /* backend does not provide hotplug support */ + r = usbi_backend.get_device_list(ctx, &discdevs); + } + + if (r < 0) { + len = r; + goto out; + } + + /* convert discovered_devs into a list */ + len = (ssize_t)discdevs->len; + ret = calloc((size_t)len + 1, sizeof(struct libusb_device *)); + if (!ret) { + len = LIBUSB_ERROR_NO_MEM; + goto out; + } + + ret[len] = NULL; + for (i = 0; i < len; i++) { + struct libusb_device *dev = discdevs->devices[i]; + ret[i] = libusb_ref_device(dev); + } + *list = ret; + +out: + if (discdevs) + discovered_devs_free(discdevs); + return len; +} + +/** \ingroup libusb_dev + * Frees a list of devices previously discovered using + * libusb_get_device_list(). If the unref_devices parameter is set, the + * reference count of each device in the list is decremented by 1. + * \param list the list to free + * \param unref_devices whether to unref the devices in the list + */ +void API_EXPORTED libusb_free_device_list(libusb_device **list, + int unref_devices) +{ + if (!list) + return; + + if (unref_devices) { + int i = 0; + struct libusb_device *dev; + + while ((dev = list[i++]) != NULL) + libusb_unref_device(dev); + } + free(list); +} + +/** \ingroup libusb_dev + * Get the number of the bus that a device is connected to. + * \param dev a device + * \returns the bus number + */ +uint8_t API_EXPORTED libusb_get_bus_number(libusb_device *dev) +{ + return dev->bus_number; +} + +/** \ingroup libusb_dev + * Get the number of the port that a device is connected to. + * Unless the OS does something funky, or you are hot-plugging USB extension cards, + * the port number returned by this call is usually guaranteed to be uniquely tied + * to a physical port, meaning that different devices plugged on the same physical + * port should return the same port number. + * + * But outside of this, there is no guarantee that the port number returned by this + * call will remain the same, or even match the order in which ports have been + * numbered by the HUB/HCD manufacturer. + * + * \param dev a device + * \returns the port number (0 if not available) + */ +uint8_t API_EXPORTED libusb_get_port_number(libusb_device *dev) +{ + return dev->port_number; +} + +/** \ingroup libusb_dev + * Get the list of all port numbers from root for the specified device + * + * Since version 1.0.16, \ref LIBUSB_API_VERSION >= 0x01000102 + * \param dev a device + * \param port_numbers the array that should contain the port numbers + * \param port_numbers_len the maximum length of the array. As per the USB 3.0 + * specs, the current maximum limit for the depth is 7. + * \returns the number of elements filled + * \returns LIBUSB_ERROR_OVERFLOW if the array is too small + */ +int API_EXPORTED libusb_get_port_numbers(libusb_device *dev, + uint8_t *port_numbers, int port_numbers_len) +{ + int i = port_numbers_len; + struct libusb_context *ctx = DEVICE_CTX(dev); + + if (port_numbers_len <= 0) + return LIBUSB_ERROR_INVALID_PARAM; + + // HCDs can be listed as devices with port #0 + while((dev) && (dev->port_number != 0)) { + if (--i < 0) { + usbi_warn(ctx, "port numbers array is too small"); + return LIBUSB_ERROR_OVERFLOW; + } + port_numbers[i] = dev->port_number; + dev = dev->parent_dev; + } + if (i < port_numbers_len) + memmove(port_numbers, &port_numbers[i], port_numbers_len - i); + return port_numbers_len - i; +} + +/** \ingroup libusb_dev + * \deprecated Please use \ref libusb_get_port_numbers() instead. + */ +int API_EXPORTED libusb_get_port_path(libusb_context *ctx, libusb_device *dev, + uint8_t *port_numbers, uint8_t port_numbers_len) +{ + UNUSED(ctx); + + return libusb_get_port_numbers(dev, port_numbers, port_numbers_len); +} + +/** \ingroup libusb_dev + * Get the the parent from the specified device. + * \param dev a device + * \returns the device parent or NULL if not available + * You should issue a \ref libusb_get_device_list() before calling this + * function and make sure that you only access the parent before issuing + * \ref libusb_free_device_list(). The reason is that libusb currently does + * not maintain a permanent list of device instances, and therefore can + * only guarantee that parents are fully instantiated within a + * libusb_get_device_list() - libusb_free_device_list() block. + */ +DEFAULT_VISIBILITY +libusb_device * LIBUSB_CALL libusb_get_parent(libusb_device *dev) +{ + return dev->parent_dev; +} + +/** \ingroup libusb_dev + * Get the address of the device on the bus it is connected to. + * \param dev a device + * \returns the device address + */ +uint8_t API_EXPORTED libusb_get_device_address(libusb_device *dev) +{ + return dev->device_address; +} + +/** \ingroup libusb_dev + * Get the negotiated connection speed for a device. + * \param dev a device + * \returns a \ref libusb_speed code, where LIBUSB_SPEED_UNKNOWN means that + * the OS doesn't know or doesn't support returning the negotiated speed. + */ +int API_EXPORTED libusb_get_device_speed(libusb_device *dev) +{ + return dev->speed; +} + +static const struct libusb_endpoint_descriptor *find_endpoint( + struct libusb_config_descriptor *config, unsigned char endpoint) +{ + int iface_idx; + for (iface_idx = 0; iface_idx < config->bNumInterfaces; iface_idx++) { + const struct libusb_interface *iface = &config->interface[iface_idx]; + int altsetting_idx; + + for (altsetting_idx = 0; altsetting_idx < iface->num_altsetting; + altsetting_idx++) { + const struct libusb_interface_descriptor *altsetting + = &iface->altsetting[altsetting_idx]; + int ep_idx; + + for (ep_idx = 0; ep_idx < altsetting->bNumEndpoints; ep_idx++) { + const struct libusb_endpoint_descriptor *ep = + &altsetting->endpoint[ep_idx]; + if (ep->bEndpointAddress == endpoint) + return ep; + } + } + } + return NULL; +} + +/** \ingroup libusb_dev + * Convenience function to retrieve the wMaxPacketSize value for a particular + * endpoint in the active device configuration. + * + * This function was originally intended to be of assistance when setting up + * isochronous transfers, but a design mistake resulted in this function + * instead. It simply returns the wMaxPacketSize value without considering + * its contents. If you're dealing with isochronous transfers, you probably + * want libusb_get_max_iso_packet_size() instead. + * + * \param dev a device + * \param endpoint address of the endpoint in question + * \returns the wMaxPacketSize value + * \returns LIBUSB_ERROR_NOT_FOUND if the endpoint does not exist + * \returns LIBUSB_ERROR_OTHER on other failure + */ +int API_EXPORTED libusb_get_max_packet_size(libusb_device *dev, + unsigned char endpoint) +{ + struct libusb_config_descriptor *config; + const struct libusb_endpoint_descriptor *ep; + int r; + + r = libusb_get_active_config_descriptor(dev, &config); + if (r < 0) { + usbi_err(DEVICE_CTX(dev), + "could not retrieve active config descriptor"); + return LIBUSB_ERROR_OTHER; + } + + ep = find_endpoint(config, endpoint); + if (!ep) { + r = LIBUSB_ERROR_NOT_FOUND; + goto out; + } + + r = ep->wMaxPacketSize; + +out: + libusb_free_config_descriptor(config); + return r; +} + +/** \ingroup libusb_dev + * Calculate the maximum packet size which a specific endpoint is capable is + * sending or receiving in the duration of 1 microframe + * + * Only the active configuration is examined. The calculation is based on the + * wMaxPacketSize field in the endpoint descriptor as described in section + * 9.6.6 in the USB 2.0 specifications. + * + * If acting on an isochronous or interrupt endpoint, this function will + * multiply the value found in bits 0:10 by the number of transactions per + * microframe (determined by bits 11:12). Otherwise, this function just + * returns the numeric value found in bits 0:10. For USB 3.0 device, it + * will attempts to retrieve the Endpoint Companion Descriptor to return + * wBytesPerInterval. + * + * This function is useful for setting up isochronous transfers, for example + * you might pass the return value from this function to + * libusb_set_iso_packet_lengths() in order to set the length field of every + * isochronous packet in a transfer. + * + * Since v1.0.3. + * + * \param dev a device + * \param endpoint address of the endpoint in question + * \returns the maximum packet size which can be sent/received on this endpoint + * \returns LIBUSB_ERROR_NOT_FOUND if the endpoint does not exist + * \returns LIBUSB_ERROR_OTHER on other failure + */ +int API_EXPORTED libusb_get_max_iso_packet_size(libusb_device *dev, + unsigned char endpoint) +{ + struct libusb_config_descriptor *config; + const struct libusb_endpoint_descriptor *ep; + struct libusb_ss_endpoint_companion_descriptor *ss_ep_cmp; + enum libusb_endpoint_transfer_type ep_type; + uint16_t val; + int r; + int speed; + + r = libusb_get_active_config_descriptor(dev, &config); + if (r < 0) { + usbi_err(DEVICE_CTX(dev), + "could not retrieve active config descriptor"); + return LIBUSB_ERROR_OTHER; + } + + ep = find_endpoint(config, endpoint); + if (!ep) { + r = LIBUSB_ERROR_NOT_FOUND; + goto out; + } + + speed = libusb_get_device_speed(dev); + if (speed >= LIBUSB_SPEED_SUPER) { + r = libusb_get_ss_endpoint_companion_descriptor(dev->ctx, ep, &ss_ep_cmp); + if (r == LIBUSB_SUCCESS) { + r = ss_ep_cmp->wBytesPerInterval; + libusb_free_ss_endpoint_companion_descriptor(ss_ep_cmp); + } + } + + /* If the device isn't a SuperSpeed device or retrieving the SS endpoint didn't worked. */ + if (speed < LIBUSB_SPEED_SUPER || r < 0) { + val = ep->wMaxPacketSize; + ep_type = (enum libusb_endpoint_transfer_type) (ep->bmAttributes & 0x3); + + r = val & 0x07ff; + if (ep_type == LIBUSB_ENDPOINT_TRANSFER_TYPE_ISOCHRONOUS + || ep_type == LIBUSB_ENDPOINT_TRANSFER_TYPE_INTERRUPT) + r *= (1 + ((val >> 11) & 3)); + } + +out: + libusb_free_config_descriptor(config); + return r; +} + +/** \ingroup libusb_dev + * Increment the reference count of a device. + * \param dev the device to reference + * \returns the same device + */ +DEFAULT_VISIBILITY +libusb_device * LIBUSB_CALL libusb_ref_device(libusb_device *dev) +{ + long refcnt; + + refcnt = usbi_atomic_inc(&dev->refcnt); + assert(refcnt >= 2); + + return dev; +} + +/** \ingroup libusb_dev + * Decrement the reference count of a device. If the decrement operation + * causes the reference count to reach zero, the device shall be destroyed. + * \param dev the device to unreference + */ +void API_EXPORTED libusb_unref_device(libusb_device *dev) +{ + long refcnt; + + if (!dev) + return; + + refcnt = usbi_atomic_dec(&dev->refcnt); + assert(refcnt >= 0); + + if (refcnt == 0) { + usbi_dbg(DEVICE_CTX(dev), "destroy device %d.%d", dev->bus_number, dev->device_address); + + libusb_unref_device(dev->parent_dev); + + if (usbi_backend.destroy_device) + usbi_backend.destroy_device(dev); + + if (!libusb_has_capability(LIBUSB_CAP_HAS_HOTPLUG)) { + /* backend does not support hotplug */ + usbi_disconnect_device(dev); + } + + free(dev); + } +} + +/** \ingroup libusb_dev + * Wrap a platform-specific system device handle and obtain a libusb device + * handle for the underlying device. The handle allows you to use libusb to + * perform I/O on the device in question. + * + * Call libusb_set_option(NULL, LIBUSB_OPTION_NO_DEVICE_DISCOVERY) before + * libusb_init() if you want to skip enumeration of USB devices. In particular, + * this might be needed on Android if you don't have authority to access USB + * devices in general. + * + * On Linux, the system device handle must be a valid file descriptor opened + * on the device node. + * + * The system device handle must remain open until libusb_close() is called. + * The system device handle will not be closed by libusb_close(). + * + * Internally, this function creates a temporary device and makes it + * available to you through libusb_get_device(). This device is destroyed + * during libusb_close(). The device shall not be opened through libusb_open(). + * + * This is a non-blocking function; no requests are sent over the bus. + * + * Since version 1.0.23, \ref LIBUSB_API_VERSION >= 0x01000107 + * + * \param ctx the context to operate on, or NULL for the default context + * \param sys_dev the platform-specific system device handle + * \param dev_handle output location for the returned device handle pointer. Only + * populated when the return code is 0. + * \returns 0 on success + * \returns LIBUSB_ERROR_NO_MEM on memory allocation failure + * \returns LIBUSB_ERROR_ACCESS if the user has insufficient permissions + * \returns LIBUSB_ERROR_NOT_SUPPORTED if the operation is not supported on this + * platform + * \returns another LIBUSB_ERROR code on other failure + */ +int API_EXPORTED libusb_wrap_sys_device(libusb_context *ctx, intptr_t sys_dev, + libusb_device_handle **dev_handle) +{ + struct libusb_device_handle *_dev_handle; + size_t priv_size = usbi_backend.device_handle_priv_size; + int r; + + usbi_dbg(ctx, "wrap_sys_device 0x%" PRIxPTR, (uintptr_t)sys_dev); + + ctx = usbi_get_context(ctx); + + if (!usbi_backend.wrap_sys_device) + return LIBUSB_ERROR_NOT_SUPPORTED; + + _dev_handle = calloc(1, PTR_ALIGN(sizeof(*_dev_handle)) + priv_size); + if (!_dev_handle) + return LIBUSB_ERROR_NO_MEM; + + usbi_mutex_init(&_dev_handle->lock); + + r = usbi_backend.wrap_sys_device(ctx, _dev_handle, sys_dev); + if (r < 0) { + usbi_dbg(ctx, "wrap_sys_device 0x%" PRIxPTR " returns %d", (uintptr_t)sys_dev, r); + usbi_mutex_destroy(&_dev_handle->lock); + free(_dev_handle); + return r; + } + + usbi_mutex_lock(&ctx->open_devs_lock); + list_add(&_dev_handle->list, &ctx->open_devs); + usbi_mutex_unlock(&ctx->open_devs_lock); + *dev_handle = _dev_handle; + + return 0; +} + +/** \ingroup libusb_dev + * Open a device and obtain a device handle. A handle allows you to perform + * I/O on the device in question. + * + * Internally, this function adds a reference to the device and makes it + * available to you through libusb_get_device(). This reference is removed + * during libusb_close(). + * + * This is a non-blocking function; no requests are sent over the bus. + * + * \param dev the device to open + * \param dev_handle output location for the returned device handle pointer. Only + * populated when the return code is 0. + * \returns 0 on success + * \returns LIBUSB_ERROR_NO_MEM on memory allocation failure + * \returns LIBUSB_ERROR_ACCESS if the user has insufficient permissions + * \returns LIBUSB_ERROR_NO_DEVICE if the device has been disconnected + * \returns another LIBUSB_ERROR code on other failure + */ +int API_EXPORTED libusb_open(libusb_device *dev, + libusb_device_handle **dev_handle) +{ + struct libusb_context *ctx = DEVICE_CTX(dev); + struct libusb_device_handle *_dev_handle; + size_t priv_size = usbi_backend.device_handle_priv_size; + int r; + + usbi_dbg(DEVICE_CTX(dev), "open %d.%d", dev->bus_number, dev->device_address); + + if (!usbi_atomic_load(&dev->attached)) + return LIBUSB_ERROR_NO_DEVICE; + + _dev_handle = calloc(1, PTR_ALIGN(sizeof(*_dev_handle)) + priv_size); + if (!_dev_handle) + return LIBUSB_ERROR_NO_MEM; + + usbi_mutex_init(&_dev_handle->lock); + + _dev_handle->dev = libusb_ref_device(dev); + + r = usbi_backend.open(_dev_handle); + if (r < 0) { + usbi_dbg(DEVICE_CTX(dev), "open %d.%d returns %d", dev->bus_number, dev->device_address, r); + libusb_unref_device(dev); + usbi_mutex_destroy(&_dev_handle->lock); + free(_dev_handle); + return r; + } + + usbi_mutex_lock(&ctx->open_devs_lock); + list_add(&_dev_handle->list, &ctx->open_devs); + usbi_mutex_unlock(&ctx->open_devs_lock); + *dev_handle = _dev_handle; + + return 0; +} + +/** \ingroup libusb_dev + * Convenience function for finding a device with a particular + * <tt>idVendor</tt>/<tt>idProduct</tt> combination. This function is intended + * for those scenarios where you are using libusb to knock up a quick test + * application - it allows you to avoid calling libusb_get_device_list() and + * worrying about traversing/freeing the list. + * + * This function has limitations and is hence not intended for use in real + * applications: if multiple devices have the same IDs it will only + * give you the first one, etc. + * + * \param ctx the context to operate on, or NULL for the default context + * \param vendor_id the idVendor value to search for + * \param product_id the idProduct value to search for + * \returns a device handle for the first found device, or NULL on error + * or if the device could not be found. */ +DEFAULT_VISIBILITY +libusb_device_handle * LIBUSB_CALL libusb_open_device_with_vid_pid( + libusb_context *ctx, uint16_t vendor_id, uint16_t product_id) +{ + struct libusb_device **devs; + struct libusb_device *found = NULL; + struct libusb_device *dev; + struct libusb_device_handle *dev_handle = NULL; + size_t i = 0; + int r; + + if (libusb_get_device_list(ctx, &devs) < 0) + return NULL; + + while ((dev = devs[i++]) != NULL) { + struct libusb_device_descriptor desc; + r = libusb_get_device_descriptor(dev, &desc); + if (r < 0) + goto out; + if (desc.idVendor == vendor_id && desc.idProduct == product_id) { + found = dev; + break; + } + } + + if (found) { + r = libusb_open(found, &dev_handle); + if (r < 0) + dev_handle = NULL; + } + +out: + libusb_free_device_list(devs, 1); + return dev_handle; +} + +static void do_close(struct libusb_context *ctx, + struct libusb_device_handle *dev_handle) +{ + struct usbi_transfer *itransfer; + struct usbi_transfer *tmp; + + /* remove any transfers in flight that are for this device */ + usbi_mutex_lock(&ctx->flying_transfers_lock); + + /* safe iteration because transfers may be being deleted */ + for_each_transfer_safe(ctx, itransfer, tmp) { + struct libusb_transfer *transfer = + USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer); + + if (transfer->dev_handle != dev_handle) + continue; + + usbi_mutex_lock(&itransfer->lock); + if (!(itransfer->state_flags & USBI_TRANSFER_DEVICE_DISAPPEARED)) { + usbi_err(ctx, "Device handle closed while transfer was still being processed, but the device is still connected as far as we know"); + + if (itransfer->state_flags & USBI_TRANSFER_CANCELLING) + usbi_warn(ctx, "A cancellation for an in-flight transfer hasn't completed but closing the device handle"); + else + usbi_err(ctx, "A cancellation hasn't even been scheduled on the transfer for which the device is closing"); + } + usbi_mutex_unlock(&itransfer->lock); + + /* remove from the list of in-flight transfers and make sure + * we don't accidentally use the device handle in the future + * (or that such accesses will be easily caught and identified as a crash) + */ + list_del(&itransfer->list); + transfer->dev_handle = NULL; + + /* it is up to the user to free up the actual transfer struct. this is + * just making sure that we don't attempt to process the transfer after + * the device handle is invalid + */ + usbi_dbg(ctx, "Removed transfer %p from the in-flight list because device handle %p closed", + transfer, dev_handle); + } + usbi_mutex_unlock(&ctx->flying_transfers_lock); + + usbi_mutex_lock(&ctx->open_devs_lock); + list_del(&dev_handle->list); + usbi_mutex_unlock(&ctx->open_devs_lock); + + usbi_backend.close(dev_handle); + libusb_unref_device(dev_handle->dev); + usbi_mutex_destroy(&dev_handle->lock); + free(dev_handle); +} + +/** \ingroup libusb_dev + * Close a device handle. Should be called on all open handles before your + * application exits. + * + * Internally, this function destroys the reference that was added by + * libusb_open() on the given device. + * + * This is a non-blocking function; no requests are sent over the bus. + * + * \param dev_handle the device handle to close + */ +void API_EXPORTED libusb_close(libusb_device_handle *dev_handle) +{ + struct libusb_context *ctx; + unsigned int event_flags; + int handling_events; + + if (!dev_handle) + return; + ctx = HANDLE_CTX(dev_handle); + usbi_dbg(ctx, " "); + + handling_events = usbi_handling_events(ctx); + + /* Similarly to libusb_open(), we want to interrupt all event handlers + * at this point. More importantly, we want to perform the actual close of + * the device while holding the event handling lock (preventing any other + * thread from doing event handling) because we will be removing a file + * descriptor from the polling loop. If this is being called by the current + * event handler, we can bypass the interruption code because we already + * hold the event handling lock. */ + + if (!handling_events) { + /* Record that we are closing a device. + * Only signal an event if there are no prior pending events. */ + usbi_mutex_lock(&ctx->event_data_lock); + event_flags = ctx->event_flags; + if (!ctx->device_close++) + ctx->event_flags |= USBI_EVENT_DEVICE_CLOSE; + if (!event_flags) + usbi_signal_event(&ctx->event); + usbi_mutex_unlock(&ctx->event_data_lock); + + /* take event handling lock */ + libusb_lock_events(ctx); + } + + /* Close the device */ + do_close(ctx, dev_handle); + + if (!handling_events) { + /* We're done with closing this device. + * Clear the event pipe if there are no further pending events. */ + usbi_mutex_lock(&ctx->event_data_lock); + if (!--ctx->device_close) + ctx->event_flags &= ~USBI_EVENT_DEVICE_CLOSE; + if (!ctx->event_flags) + usbi_clear_event(&ctx->event); + usbi_mutex_unlock(&ctx->event_data_lock); + + /* Release event handling lock and wake up event waiters */ + libusb_unlock_events(ctx); + } +} + +/** \ingroup libusb_dev + * Get the underlying device for a device handle. This function does not modify + * the reference count of the returned device, so do not feel compelled to + * unreference it when you are done. + * \param dev_handle a device handle + * \returns the underlying device + */ +DEFAULT_VISIBILITY +libusb_device * LIBUSB_CALL libusb_get_device(libusb_device_handle *dev_handle) +{ + return dev_handle->dev; +} + +/** \ingroup libusb_dev + * Determine the bConfigurationValue of the currently active configuration. + * + * You could formulate your own control request to obtain this information, + * but this function has the advantage that it may be able to retrieve the + * information from operating system caches (no I/O involved). + * + * If the OS does not cache this information, then this function will block + * while a control transfer is submitted to retrieve the information. + * + * This function will return a value of 0 in the <tt>config</tt> output + * parameter if the device is in unconfigured state. + * + * \param dev_handle a device handle + * \param config output location for the bConfigurationValue of the active + * configuration (only valid for return code 0) + * \returns 0 on success + * \returns LIBUSB_ERROR_NO_DEVICE if the device has been disconnected + * \returns another LIBUSB_ERROR code on other failure + */ +int API_EXPORTED libusb_get_configuration(libusb_device_handle *dev_handle, + int *config) +{ + int r = LIBUSB_ERROR_NOT_SUPPORTED; + uint8_t tmp = 0; + struct libusb_context *ctx = HANDLE_CTX(dev_handle); + + usbi_dbg(ctx, " "); + if (usbi_backend.get_configuration) + r = usbi_backend.get_configuration(dev_handle, &tmp); + + if (r == LIBUSB_ERROR_NOT_SUPPORTED) { + usbi_dbg(ctx, "falling back to control message"); + r = libusb_control_transfer(dev_handle, LIBUSB_ENDPOINT_IN, + LIBUSB_REQUEST_GET_CONFIGURATION, 0, 0, &tmp, 1, 1000); + if (r == 1) { + r = 0; + } else if (r == 0) { + usbi_err(ctx, "zero bytes returned in ctrl transfer?"); + r = LIBUSB_ERROR_IO; + } else { + usbi_dbg(ctx, "control failed, error %d", r); + } + } + + if (r == 0) { + usbi_dbg(ctx, "active config %u", tmp); + *config = (int)tmp; + } + + return r; +} + +/** \ingroup libusb_dev + * Set the active configuration for a device. + * + * The operating system may or may not have already set an active + * configuration on the device. It is up to your application to ensure the + * correct configuration is selected before you attempt to claim interfaces + * and perform other operations. + * + * If you call this function on a device already configured with the selected + * configuration, then this function will act as a lightweight device reset: + * it will issue a SET_CONFIGURATION request using the current configuration, + * causing most USB-related device state to be reset (altsetting reset to zero, + * endpoint halts cleared, toggles reset). + * + * Not all backends support setting the configuration from user space, which + * will be indicated by the return code LIBUSB_ERROR_NOT_SUPPORTED. As this + * suggests that the platform is handling the device configuration itself, + * this error should generally be safe to ignore. + * + * You cannot change/reset configuration if your application has claimed + * interfaces. It is advised to set the desired configuration before claiming + * interfaces. + * + * Alternatively you can call libusb_release_interface() first. Note if you + * do things this way you must ensure that auto_detach_kernel_driver for + * <tt>dev</tt> is 0, otherwise the kernel driver will be re-attached when you + * release the interface(s). + * + * You cannot change/reset configuration if other applications or drivers have + * claimed interfaces. + * + * A configuration value of -1 will put the device in unconfigured state. + * The USB specifications state that a configuration value of 0 does this, + * however buggy devices exist which actually have a configuration 0. + * + * You should always use this function rather than formulating your own + * SET_CONFIGURATION control request. This is because the underlying operating + * system needs to know when such changes happen. + * + * This is a blocking function. + * + * \param dev_handle a device handle + * \param configuration the bConfigurationValue of the configuration you + * wish to activate, or -1 if you wish to put the device in an unconfigured + * state + * \returns 0 on success + * \returns LIBUSB_ERROR_NOT_FOUND if the requested configuration does not exist + * \returns LIBUSB_ERROR_BUSY if interfaces are currently claimed + * \returns LIBUSB_ERROR_NOT_SUPPORTED if setting or changing the configuration + * is not supported by the backend + * \returns LIBUSB_ERROR_NO_DEVICE if the device has been disconnected + * \returns another LIBUSB_ERROR code on other failure + * \see libusb_set_auto_detach_kernel_driver() + */ +int API_EXPORTED libusb_set_configuration(libusb_device_handle *dev_handle, + int configuration) +{ + usbi_dbg(HANDLE_CTX(dev_handle), "configuration %d", configuration); + if (configuration < -1 || configuration > (int)UINT8_MAX) + return LIBUSB_ERROR_INVALID_PARAM; + return usbi_backend.set_configuration(dev_handle, configuration); +} + +/** \ingroup libusb_dev + * Claim an interface on a given device handle. You must claim the interface + * you wish to use before you can perform I/O on any of its endpoints. + * + * It is legal to attempt to claim an already-claimed interface, in which + * case libusb just returns 0 without doing anything. + * + * If auto_detach_kernel_driver is set to 1 for <tt>dev</tt>, the kernel driver + * will be detached if necessary, on failure the detach error is returned. + * + * Claiming of interfaces is a purely logical operation; it does not cause + * any requests to be sent over the bus. Interface claiming is used to + * instruct the underlying operating system that your application wishes + * to take ownership of the interface. + * + * This is a non-blocking function. + * + * \param dev_handle a device handle + * \param interface_number the <tt>bInterfaceNumber</tt> of the interface you + * wish to claim + * \returns 0 on success + * \returns LIBUSB_ERROR_NOT_FOUND if the requested interface does not exist + * \returns LIBUSB_ERROR_BUSY if another program or driver has claimed the + * interface + * \returns LIBUSB_ERROR_NO_DEVICE if the device has been disconnected + * \returns a LIBUSB_ERROR code on other failure + * \see libusb_set_auto_detach_kernel_driver() + */ +int API_EXPORTED libusb_claim_interface(libusb_device_handle *dev_handle, + int interface_number) +{ + int r = 0; + + usbi_dbg(HANDLE_CTX(dev_handle), "interface %d", interface_number); + if (interface_number < 0 || interface_number >= USB_MAXINTERFACES) + return LIBUSB_ERROR_INVALID_PARAM; + + if (!usbi_atomic_load(&dev_handle->dev->attached)) + return LIBUSB_ERROR_NO_DEVICE; + + usbi_mutex_lock(&dev_handle->lock); + if (dev_handle->claimed_interfaces & (1U << interface_number)) + goto out; + + r = usbi_backend.claim_interface(dev_handle, (uint8_t)interface_number); + if (r == 0) + dev_handle->claimed_interfaces |= 1U << interface_number; + +out: + usbi_mutex_unlock(&dev_handle->lock); + return r; +} + +/** \ingroup libusb_dev + * Release an interface previously claimed with libusb_claim_interface(). You + * should release all claimed interfaces before closing a device handle. + * + * This is a blocking function. A SET_INTERFACE control request will be sent + * to the device, resetting interface state to the first alternate setting. + * + * If auto_detach_kernel_driver is set to 1 for <tt>dev</tt>, the kernel + * driver will be re-attached after releasing the interface. + * + * \param dev_handle a device handle + * \param interface_number the <tt>bInterfaceNumber</tt> of the + * previously-claimed interface + * \returns 0 on success + * \returns LIBUSB_ERROR_NOT_FOUND if the interface was not claimed + * \returns LIBUSB_ERROR_NO_DEVICE if the device has been disconnected + * \returns another LIBUSB_ERROR code on other failure + * \see libusb_set_auto_detach_kernel_driver() + */ +int API_EXPORTED libusb_release_interface(libusb_device_handle *dev_handle, + int interface_number) +{ + int r; + + usbi_dbg(HANDLE_CTX(dev_handle), "interface %d", interface_number); + if (interface_number < 0 || interface_number >= USB_MAXINTERFACES) + return LIBUSB_ERROR_INVALID_PARAM; + + usbi_mutex_lock(&dev_handle->lock); + if (!(dev_handle->claimed_interfaces & (1U << interface_number))) { + r = LIBUSB_ERROR_NOT_FOUND; + goto out; + } + + r = usbi_backend.release_interface(dev_handle, (uint8_t)interface_number); + if (r == 0) + dev_handle->claimed_interfaces &= ~(1U << interface_number); + +out: + usbi_mutex_unlock(&dev_handle->lock); + return r; +} + +/** \ingroup libusb_dev + * Activate an alternate setting for an interface. The interface must have + * been previously claimed with libusb_claim_interface(). + * + * You should always use this function rather than formulating your own + * SET_INTERFACE control request. This is because the underlying operating + * system needs to know when such changes happen. + * + * This is a blocking function. + * + * \param dev_handle a device handle + * \param interface_number the <tt>bInterfaceNumber</tt> of the + * previously-claimed interface + * \param alternate_setting the <tt>bAlternateSetting</tt> of the alternate + * setting to activate + * \returns 0 on success + * \returns LIBUSB_ERROR_NOT_FOUND if the interface was not claimed, or the + * requested alternate setting does not exist + * \returns LIBUSB_ERROR_NO_DEVICE if the device has been disconnected + * \returns another LIBUSB_ERROR code on other failure + */ +int API_EXPORTED libusb_set_interface_alt_setting(libusb_device_handle *dev_handle, + int interface_number, int alternate_setting) +{ + usbi_dbg(HANDLE_CTX(dev_handle), "interface %d altsetting %d", + interface_number, alternate_setting); + if (interface_number < 0 || interface_number >= USB_MAXINTERFACES) + return LIBUSB_ERROR_INVALID_PARAM; + if (alternate_setting < 0 || alternate_setting > (int)UINT8_MAX) + return LIBUSB_ERROR_INVALID_PARAM; + + if (!usbi_atomic_load(&dev_handle->dev->attached)) { + usbi_mutex_unlock(&dev_handle->lock); + return LIBUSB_ERROR_NO_DEVICE; + } + + usbi_mutex_lock(&dev_handle->lock); + if (!(dev_handle->claimed_interfaces & (1U << interface_number))) { + usbi_mutex_unlock(&dev_handle->lock); + return LIBUSB_ERROR_NOT_FOUND; + } + usbi_mutex_unlock(&dev_handle->lock); + + return usbi_backend.set_interface_altsetting(dev_handle, + (uint8_t)interface_number, (uint8_t)alternate_setting); +} + +/** \ingroup libusb_dev + * Clear the halt/stall condition for an endpoint. Endpoints with halt status + * are unable to receive or transmit data until the halt condition is stalled. + * + * You should cancel all pending transfers before attempting to clear the halt + * condition. + * + * This is a blocking function. + * + * \param dev_handle a device handle + * \param endpoint the endpoint to clear halt status + * \returns 0 on success + * \returns LIBUSB_ERROR_NOT_FOUND if the endpoint does not exist + * \returns LIBUSB_ERROR_NO_DEVICE if the device has been disconnected + * \returns another LIBUSB_ERROR code on other failure + */ +int API_EXPORTED libusb_clear_halt(libusb_device_handle *dev_handle, + unsigned char endpoint) +{ + usbi_dbg(HANDLE_CTX(dev_handle), "endpoint 0x%x", endpoint); + if (!usbi_atomic_load(&dev_handle->dev->attached)) + return LIBUSB_ERROR_NO_DEVICE; + + return usbi_backend.clear_halt(dev_handle, endpoint); +} + +/** \ingroup libusb_dev + * Perform a USB port reset to reinitialize a device. The system will attempt + * to restore the previous configuration and alternate settings after the + * reset has completed. + * + * If the reset fails, the descriptors change, or the previous state cannot be + * restored, the device will appear to be disconnected and reconnected. This + * means that the device handle is no longer valid (you should close it) and + * rediscover the device. A return code of LIBUSB_ERROR_NOT_FOUND indicates + * when this is the case. + * + * This is a blocking function which usually incurs a noticeable delay. + * + * \param dev_handle a handle of the device to reset + * \returns 0 on success + * \returns LIBUSB_ERROR_NOT_FOUND if re-enumeration is required, or if the + * device has been disconnected + * \returns another LIBUSB_ERROR code on other failure + */ +int API_EXPORTED libusb_reset_device(libusb_device_handle *dev_handle) +{ + usbi_dbg(HANDLE_CTX(dev_handle), " "); + if (!usbi_atomic_load(&dev_handle->dev->attached)) + return LIBUSB_ERROR_NO_DEVICE; + + if (usbi_backend.reset_device) + return usbi_backend.reset_device(dev_handle); + else + return LIBUSB_ERROR_NOT_SUPPORTED; +} + +/** \ingroup libusb_asyncio + * Allocate up to num_streams usb bulk streams on the specified endpoints. This + * function takes an array of endpoints rather then a single endpoint because + * some protocols require that endpoints are setup with similar stream ids. + * All endpoints passed in must belong to the same interface. + * + * Note this function may return less streams then requested. Also note that the + * same number of streams are allocated for each endpoint in the endpoint array. + * + * Stream id 0 is reserved, and should not be used to communicate with devices. + * If libusb_alloc_streams() returns with a value of N, you may use stream ids + * 1 to N. + * + * Since version 1.0.19, \ref LIBUSB_API_VERSION >= 0x01000103 + * + * \param dev_handle a device handle + * \param num_streams number of streams to try to allocate + * \param endpoints array of endpoints to allocate streams on + * \param num_endpoints length of the endpoints array + * \returns number of streams allocated, or a LIBUSB_ERROR code on failure + */ +int API_EXPORTED libusb_alloc_streams(libusb_device_handle *dev_handle, + uint32_t num_streams, unsigned char *endpoints, int num_endpoints) +{ + usbi_dbg(HANDLE_CTX(dev_handle), "streams %u eps %d", (unsigned)num_streams, num_endpoints); + + if (!num_streams || !endpoints || num_endpoints <= 0) + return LIBUSB_ERROR_INVALID_PARAM; + + if (!usbi_atomic_load(&dev_handle->dev->attached)) + return LIBUSB_ERROR_NO_DEVICE; + + if (usbi_backend.alloc_streams) + return usbi_backend.alloc_streams(dev_handle, num_streams, endpoints, + num_endpoints); + else + return LIBUSB_ERROR_NOT_SUPPORTED; +} + +/** \ingroup libusb_asyncio + * Free usb bulk streams allocated with libusb_alloc_streams(). + * + * Note streams are automatically free-ed when releasing an interface. + * + * Since version 1.0.19, \ref LIBUSB_API_VERSION >= 0x01000103 + * + * \param dev_handle a device handle + * \param endpoints array of endpoints to free streams on + * \param num_endpoints length of the endpoints array + * \returns LIBUSB_SUCCESS, or a LIBUSB_ERROR code on failure + */ +int API_EXPORTED libusb_free_streams(libusb_device_handle *dev_handle, + unsigned char *endpoints, int num_endpoints) +{ + usbi_dbg(HANDLE_CTX(dev_handle), "eps %d", num_endpoints); + + if (!endpoints || num_endpoints <= 0) + return LIBUSB_ERROR_INVALID_PARAM; + + if (!usbi_atomic_load(&dev_handle->dev->attached)) + return LIBUSB_ERROR_NO_DEVICE; + + if (usbi_backend.free_streams) + return usbi_backend.free_streams(dev_handle, endpoints, + num_endpoints); + else + return LIBUSB_ERROR_NOT_SUPPORTED; +} + +/** \ingroup libusb_asyncio + * Attempts to allocate a block of persistent DMA memory suitable for transfers + * against the given device. If successful, will return a block of memory + * that is suitable for use as "buffer" in \ref libusb_transfer against this + * device. Using this memory instead of regular memory means that the host + * controller can use DMA directly into the buffer to increase performance, and + * also that transfers can no longer fail due to kernel memory fragmentation. + * + * Note that this means you should not modify this memory (or even data on + * the same cache lines) when a transfer is in progress, although it is legal + * to have several transfers going on within the same memory block. + * + * Will return NULL on failure. Many systems do not support such zero-copy + * and will always return NULL. Memory allocated with this function must be + * freed with \ref libusb_dev_mem_free. Specifically, this means that the + * flag \ref LIBUSB_TRANSFER_FREE_BUFFER cannot be used to free memory allocated + * with this function. + * + * Since version 1.0.21, \ref LIBUSB_API_VERSION >= 0x01000105 + * + * \param dev_handle a device handle + * \param length size of desired data buffer + * \returns a pointer to the newly allocated memory, or NULL on failure + */ +DEFAULT_VISIBILITY +unsigned char * LIBUSB_CALL libusb_dev_mem_alloc(libusb_device_handle *dev_handle, + size_t length) +{ + if (!usbi_atomic_load(&dev_handle->dev->attached)) + return NULL; + + if (usbi_backend.dev_mem_alloc) + return usbi_backend.dev_mem_alloc(dev_handle, length); + else + return NULL; +} + +/** \ingroup libusb_asyncio + * Free device memory allocated with libusb_dev_mem_alloc(). + * + * \param dev_handle a device handle + * \param buffer pointer to the previously allocated memory + * \param length size of previously allocated memory + * \returns LIBUSB_SUCCESS, or a LIBUSB_ERROR code on failure + */ +int API_EXPORTED libusb_dev_mem_free(libusb_device_handle *dev_handle, + unsigned char *buffer, size_t length) +{ + if (usbi_backend.dev_mem_free) + return usbi_backend.dev_mem_free(dev_handle, buffer, length); + else + return LIBUSB_ERROR_NOT_SUPPORTED; +} + +/** \ingroup libusb_dev + * Determine if a kernel driver is active on an interface. If a kernel driver + * is active, you cannot claim the interface, and libusb will be unable to + * perform I/O. + * + * This functionality is not available on Windows. + * + * \param dev_handle a device handle + * \param interface_number the interface to check + * \returns 0 if no kernel driver is active + * \returns 1 if a kernel driver is active + * \returns LIBUSB_ERROR_NO_DEVICE if the device has been disconnected + * \returns LIBUSB_ERROR_NOT_SUPPORTED on platforms where the functionality + * is not available + * \returns another LIBUSB_ERROR code on other failure + * \see libusb_detach_kernel_driver() + */ +int API_EXPORTED libusb_kernel_driver_active(libusb_device_handle *dev_handle, + int interface_number) +{ + usbi_dbg(HANDLE_CTX(dev_handle), "interface %d", interface_number); + + if (interface_number < 0 || interface_number >= USB_MAXINTERFACES) + return LIBUSB_ERROR_INVALID_PARAM; + + if (!usbi_atomic_load(&dev_handle->dev->attached)) + return LIBUSB_ERROR_NO_DEVICE; + + if (usbi_backend.kernel_driver_active) + return usbi_backend.kernel_driver_active(dev_handle, (uint8_t)interface_number); + else + return LIBUSB_ERROR_NOT_SUPPORTED; +} + +/** \ingroup libusb_dev + * Detach a kernel driver from an interface. If successful, you will then be + * able to claim the interface and perform I/O. + * + * This functionality is not available on Windows. + * + * Note that libusb itself also talks to the device through a special kernel + * driver, if this driver is already attached to the device, this call will + * not detach it and return LIBUSB_ERROR_NOT_FOUND. + * + * \param dev_handle a device handle + * \param interface_number the interface to detach the driver from + * \returns 0 on success + * \returns LIBUSB_ERROR_NOT_FOUND if no kernel driver was active + * \returns LIBUSB_ERROR_INVALID_PARAM if the interface does not exist + * \returns LIBUSB_ERROR_NO_DEVICE if the device has been disconnected + * \returns LIBUSB_ERROR_NOT_SUPPORTED on platforms where the functionality + * is not available + * \returns another LIBUSB_ERROR code on other failure + * \see libusb_kernel_driver_active() + */ +int API_EXPORTED libusb_detach_kernel_driver(libusb_device_handle *dev_handle, + int interface_number) +{ + usbi_dbg(HANDLE_CTX(dev_handle), "interface %d", interface_number); + + if (interface_number < 0 || interface_number >= USB_MAXINTERFACES) + return LIBUSB_ERROR_INVALID_PARAM; + + if (!usbi_atomic_load(&dev_handle->dev->attached)) + return LIBUSB_ERROR_NO_DEVICE; + + if (usbi_backend.detach_kernel_driver) + return usbi_backend.detach_kernel_driver(dev_handle, (uint8_t)interface_number); + else + return LIBUSB_ERROR_NOT_SUPPORTED; +} + +/** \ingroup libusb_dev + * Re-attach an interface's kernel driver, which was previously detached + * using libusb_detach_kernel_driver(). + * + * This functionality is not available on Windows. + * + * \param dev_handle a device handle + * \param interface_number the interface to attach the driver from + * \returns 0 on success + * \returns LIBUSB_ERROR_NOT_FOUND if no kernel driver was active + * \returns LIBUSB_ERROR_INVALID_PARAM if the interface does not exist + * \returns LIBUSB_ERROR_NO_DEVICE if the device has been disconnected + * \returns LIBUSB_ERROR_NOT_SUPPORTED on platforms where the functionality + * is not available + * \returns LIBUSB_ERROR_BUSY if the driver cannot be attached because the + * interface is claimed by a program or driver + * \returns another LIBUSB_ERROR code on other failure + * \see libusb_kernel_driver_active() + */ +int API_EXPORTED libusb_attach_kernel_driver(libusb_device_handle *dev_handle, + int interface_number) +{ + usbi_dbg(HANDLE_CTX(dev_handle), "interface %d", interface_number); + + if (interface_number < 0 || interface_number >= USB_MAXINTERFACES) + return LIBUSB_ERROR_INVALID_PARAM; + + if (!usbi_atomic_load(&dev_handle->dev->attached)) + return LIBUSB_ERROR_NO_DEVICE; + + if (usbi_backend.attach_kernel_driver) + return usbi_backend.attach_kernel_driver(dev_handle, (uint8_t)interface_number); + else + return LIBUSB_ERROR_NOT_SUPPORTED; +} + +/** \ingroup libusb_dev + * Enable/disable libusb's automatic kernel driver detachment. When this is + * enabled libusb will automatically detach the kernel driver on an interface + * when claiming the interface, and attach it when releasing the interface. + * + * Automatic kernel driver detachment is disabled on newly opened device + * handles by default. + * + * On platforms which do not have LIBUSB_CAP_SUPPORTS_DETACH_KERNEL_DRIVER + * this function will return LIBUSB_ERROR_NOT_SUPPORTED, and libusb will + * continue as if this function was never called. + * + * \param dev_handle a device handle + * \param enable whether to enable or disable auto kernel driver detachment + * + * \returns LIBUSB_SUCCESS on success + * \returns LIBUSB_ERROR_NOT_SUPPORTED on platforms where the functionality + * is not available + * \see libusb_claim_interface() + * \see libusb_release_interface() + * \see libusb_set_configuration() + */ +int API_EXPORTED libusb_set_auto_detach_kernel_driver( + libusb_device_handle *dev_handle, int enable) +{ + if (!(usbi_backend.caps & USBI_CAP_SUPPORTS_DETACH_KERNEL_DRIVER)) + return LIBUSB_ERROR_NOT_SUPPORTED; + + dev_handle->auto_detach_kernel_driver = enable; + return LIBUSB_SUCCESS; +} + +/** \ingroup libusb_lib + * \deprecated Use libusb_set_option() instead using the + * \ref LIBUSB_OPTION_LOG_LEVEL option. + */ +void API_EXPORTED libusb_set_debug(libusb_context *ctx, int level) +{ +#if defined(ENABLE_LOGGING) && !defined(ENABLE_DEBUG_LOGGING) + ctx = usbi_get_context(ctx); + if (!ctx->debug_fixed) { + level = CLAMP(level, LIBUSB_LOG_LEVEL_NONE, LIBUSB_LOG_LEVEL_DEBUG); + ctx->debug = (enum libusb_log_level)level; + } +#else + UNUSED(ctx); + UNUSED(level); +#endif +} + +/** \ingroup libusb_lib + * Set log handler. + * + * libusb will redirect its log messages to the provided callback function. + * libusb supports redirection of per context and global log messages. + * Log messages sent to the context will be sent to the global log handler too. + * + * If libusb is compiled without message logging or USE_SYSTEM_LOGGING_FACILITY + * is defined then global callback function will never be called. + * If ENABLE_DEBUG_LOGGING is defined then per context callback function will + * never be called. + * + * Since version 1.0.23, \ref LIBUSB_API_VERSION >= 0x01000107 + * + * \param ctx context on which to assign log handler, or NULL for the default + * context. Parameter ignored if only LIBUSB_LOG_CB_GLOBAL mode is requested. + * \param cb pointer to the callback function, or NULL to stop log + * messages redirection + * \param mode mode of callback function operation. Several modes can be + * selected for a single callback function, see \ref libusb_log_cb_mode for + * a description. + * \see libusb_log_cb, libusb_log_cb_mode + */ +void API_EXPORTED libusb_set_log_cb(libusb_context *ctx, libusb_log_cb cb, + int mode) +{ +#if defined(ENABLE_LOGGING) && (!defined(ENABLE_DEBUG_LOGGING) || !defined(USE_SYSTEM_LOGGING_FACILITY)) +#if !defined(USE_SYSTEM_LOGGING_FACILITY) + if (mode & LIBUSB_LOG_CB_GLOBAL) + log_handler = cb; +#endif +#if !defined(ENABLE_DEBUG_LOGGING) + if (mode & LIBUSB_LOG_CB_CONTEXT) { + ctx = usbi_get_context(ctx); + ctx->log_handler = cb; + } +#else + UNUSED(ctx); +#endif +#else + UNUSED(ctx); + UNUSED(cb); + UNUSED(mode); +#endif +} + +/** \ingroup libusb_lib + * Set an option in the library. + * + * Use this function to configure a specific option within the library. + * + * Some options require one or more arguments to be provided. Consult each + * option's documentation for specific requirements. + * + * If the context ctx is NULL, the option will be added to a list of default + * options that will be applied to all subsequently created contexts. + * + * Since version 1.0.22, \ref LIBUSB_API_VERSION >= 0x01000106 + * + * \param ctx context on which to operate + * \param option which option to set + * \param ... any required arguments for the specified option + * + * \returns LIBUSB_SUCCESS on success + * \returns LIBUSB_ERROR_INVALID_PARAM if the option or arguments are invalid + * \returns LIBUSB_ERROR_NOT_SUPPORTED if the option is valid but not supported + * on this platform + * \returns LIBUSB_ERROR_NOT_FOUND if LIBUSB_OPTION_USE_USBDK is valid on this platform but UsbDk is not available + */ +int API_EXPORTED libusb_set_option(libusb_context *ctx, + enum libusb_option option, ...) +{ + int arg = 0, r = LIBUSB_SUCCESS; + va_list ap; + + va_start(ap, option); + if (LIBUSB_OPTION_LOG_LEVEL == option) { + arg = va_arg(ap, int); + if (arg < LIBUSB_LOG_LEVEL_NONE || arg > LIBUSB_LOG_LEVEL_DEBUG) { + r = LIBUSB_ERROR_INVALID_PARAM; + } + } + va_end(ap); + + if (LIBUSB_SUCCESS != r) { + return r; + } + + if (option >= LIBUSB_OPTION_MAX) { + return LIBUSB_ERROR_INVALID_PARAM; + } + + if (NULL == ctx) { + usbi_mutex_static_lock(&default_context_lock); + default_context_options[option].is_set = 1; + if (LIBUSB_OPTION_LOG_LEVEL == option) { + default_context_options[option].arg.ival = arg; + } + usbi_mutex_static_unlock(&default_context_lock); + } + + ctx = usbi_get_context(ctx); + if (NULL == ctx) { + return LIBUSB_SUCCESS; + } + + switch (option) { + case LIBUSB_OPTION_LOG_LEVEL: +#if defined(ENABLE_LOGGING) && !defined(ENABLE_DEBUG_LOGGING) + if (!ctx->debug_fixed) + ctx->debug = (enum libusb_log_level)arg; +#endif + break; + + /* Handle all backend-specific options here */ + case LIBUSB_OPTION_USE_USBDK: + case LIBUSB_OPTION_NO_DEVICE_DISCOVERY: + if (usbi_backend.set_option) + return usbi_backend.set_option(ctx, option, ap); + + return LIBUSB_ERROR_NOT_SUPPORTED; + break; + + case LIBUSB_OPTION_MAX: + default: + return LIBUSB_ERROR_INVALID_PARAM; + } + + return LIBUSB_SUCCESS;; +} + +#if defined(ENABLE_LOGGING) && !defined(ENABLE_DEBUG_LOGGING) +/* returns the log level as defined in the LIBUSB_DEBUG environment variable. + * if LIBUSB_DEBUG is not present or not a number, returns LIBUSB_LOG_LEVEL_NONE. + * value is clamped to ensure it is within the valid range of possibilities. + */ +static enum libusb_log_level get_env_debug_level(void) +{ + const char *dbg = getenv("LIBUSB_DEBUG"); + enum libusb_log_level level; + if (dbg) { + int dbg_level = atoi(dbg); + dbg_level = CLAMP(dbg_level, LIBUSB_LOG_LEVEL_NONE, LIBUSB_LOG_LEVEL_DEBUG); + level = (enum libusb_log_level)dbg_level; + } else { + level = LIBUSB_LOG_LEVEL_NONE; + } + return level; +} +#endif + +/** \ingroup libusb_lib + * Initialize libusb. This function must be called before calling any other + * libusb function. + * + * If you do not provide an output location for a context pointer, a default + * context will be created. If there was already a default context, it will + * be reused (and nothing will be initialized/reinitialized). + * + * \param ctx Optional output location for context pointer. + * Only valid on return code 0. + * \returns 0 on success, or a LIBUSB_ERROR code on failure + * \see libusb_contexts + */ +int API_EXPORTED libusb_init(libusb_context **ctx) +{ + size_t priv_size = usbi_backend.context_priv_size; + struct libusb_context *_ctx; + int r; + + usbi_mutex_static_lock(&default_context_lock); + + if (!ctx && usbi_default_context) { + usbi_dbg(usbi_default_context, "reusing default context"); + default_context_refcnt++; + usbi_mutex_static_unlock(&default_context_lock); + return 0; + } + + /* check for first init */ + if (!active_contexts_list.next) { + list_init(&active_contexts_list); + usbi_get_monotonic_time(×tamp_origin); + } + + _ctx = calloc(1, PTR_ALIGN(sizeof(*_ctx)) + priv_size); + if (!_ctx) { + usbi_mutex_static_unlock(&default_context_lock); + return LIBUSB_ERROR_NO_MEM; + } + +#if defined(ENABLE_LOGGING) && !defined(ENABLE_DEBUG_LOGGING) + if (NULL == ctx && default_context_options[LIBUSB_OPTION_LOG_LEVEL].is_set) { + _ctx->debug = default_context_options[LIBUSB_OPTION_LOG_LEVEL].arg.ival; + } else { + _ctx->debug = get_env_debug_level(); + } + if (_ctx->debug != LIBUSB_LOG_LEVEL_NONE) + _ctx->debug_fixed = 1; +#endif + + usbi_mutex_init(&_ctx->usb_devs_lock); + usbi_mutex_init(&_ctx->open_devs_lock); + list_init(&_ctx->usb_devs); + list_init(&_ctx->open_devs); + + /* apply default options to all new contexts */ + for (enum libusb_option option = 0 ; option < LIBUSB_OPTION_MAX ; option++) { + if (LIBUSB_OPTION_LOG_LEVEL == option || !default_context_options[option].is_set) { + continue; + } + r = libusb_set_option(_ctx, option); + if (LIBUSB_SUCCESS != r) + goto err_free_ctx; + } + + /* default context must be initialized before calling usbi_dbg */ + if (!ctx) { + usbi_default_context = _ctx; + default_context_refcnt = 1; + usbi_dbg(usbi_default_context, "created default context"); + } + + usbi_dbg(_ctx, "libusb v%u.%u.%u.%u%s", libusb_version_internal.major, libusb_version_internal.minor, + libusb_version_internal.micro, libusb_version_internal.nano, libusb_version_internal.rc); + + r = usbi_io_init(_ctx); + if (r < 0) + goto err_free_ctx; + + usbi_mutex_static_lock(&active_contexts_lock); + list_add(&_ctx->list, &active_contexts_list); + usbi_mutex_static_unlock(&active_contexts_lock); + + usbi_hotplug_init(_ctx); + + if (usbi_backend.init) { + r = usbi_backend.init(_ctx); + if (r) + goto err_io_exit; + } + + if (ctx) + *ctx = _ctx; + + usbi_mutex_static_unlock(&default_context_lock); + + return 0; + +err_io_exit: + usbi_mutex_static_lock(&active_contexts_lock); + list_del(&_ctx->list); + usbi_mutex_static_unlock(&active_contexts_lock); + + usbi_hotplug_exit(_ctx); + usbi_io_exit(_ctx); + +err_free_ctx: + if (!ctx) { + /* clear default context that was not fully initialized */ + usbi_default_context = NULL; + default_context_refcnt = 0; + } + + usbi_mutex_destroy(&_ctx->open_devs_lock); + usbi_mutex_destroy(&_ctx->usb_devs_lock); + + free(_ctx); + + usbi_mutex_static_unlock(&default_context_lock); + + return r; +} + +/** \ingroup libusb_lib + * Deinitialize libusb. Should be called after closing all open devices and + * before your application terminates. + * \param ctx the context to deinitialize, or NULL for the default context + */ +void API_EXPORTED libusb_exit(libusb_context *ctx) +{ + struct libusb_context *_ctx; + struct libusb_device *dev; + + usbi_mutex_static_lock(&default_context_lock); + + /* if working with default context, only actually do the deinitialization + * if we're the last user */ + if (!ctx) { + if (!usbi_default_context) { + usbi_dbg(ctx, "no default context, not initialized?"); + usbi_mutex_static_unlock(&default_context_lock); + return; + } + + if (--default_context_refcnt > 0) { + usbi_dbg(ctx, "not destroying default context"); + usbi_mutex_static_unlock(&default_context_lock); + return; + } + + usbi_dbg(ctx, "destroying default context"); + _ctx = usbi_default_context; + } else { + usbi_dbg(ctx, " "); + _ctx = ctx; + } + + usbi_mutex_static_lock(&active_contexts_lock); + list_del(&_ctx->list); + usbi_mutex_static_unlock(&active_contexts_lock); + + if (usbi_backend.exit) + usbi_backend.exit(_ctx); + + if (!ctx) + usbi_default_context = NULL; + + usbi_mutex_static_unlock(&default_context_lock); + + /* Don't bother with locking after this point because unless there is + * an application bug, nobody will be accessing the context. */ + + usbi_hotplug_exit(_ctx); + usbi_io_exit(_ctx); + + for_each_device(_ctx, dev) { + usbi_warn(_ctx, "device %d.%d still referenced", + dev->bus_number, dev->device_address); + } + + if (!list_empty(&_ctx->open_devs)) + usbi_warn(_ctx, "application left some devices open"); + + usbi_mutex_destroy(&_ctx->open_devs_lock); + usbi_mutex_destroy(&_ctx->usb_devs_lock); + + free(_ctx); +} + +/** \ingroup libusb_misc + * Check at runtime if the loaded library has a given capability. + * This call should be performed after \ref libusb_init(), to ensure the + * backend has updated its capability set. + * + * \param capability the \ref libusb_capability to check for + * \returns nonzero if the running library has the capability, 0 otherwise + */ +int API_EXPORTED libusb_has_capability(uint32_t capability) +{ + switch (capability) { + case LIBUSB_CAP_HAS_CAPABILITY: + return 1; + case LIBUSB_CAP_HAS_HOTPLUG: + return !(usbi_backend.get_device_list); + case LIBUSB_CAP_HAS_HID_ACCESS: + return (usbi_backend.caps & USBI_CAP_HAS_HID_ACCESS); + case LIBUSB_CAP_SUPPORTS_DETACH_KERNEL_DRIVER: + return (usbi_backend.caps & USBI_CAP_SUPPORTS_DETACH_KERNEL_DRIVER); + } + return 0; +} + +#ifdef ENABLE_LOGGING + +/* this is defined in libusbi.h if needed */ +#ifdef LIBUSB_PRINTF_WIN32 +/* + * Prior to VS2015, Microsoft did not provide the snprintf() function and + * provided a vsnprintf() that did not guarantee NUL-terminated output. + * Microsoft did provide a _snprintf() function, but again it did not + * guarantee NULL-terminated output. + * + * The below implementations guarantee NUL-terminated output and are + * C99 compliant. + */ + +int usbi_snprintf(char *str, size_t size, const char *format, ...) +{ + va_list args; + int ret; + + va_start(args, format); + ret = usbi_vsnprintf(str, size, format, args); + va_end(args); + + return ret; +} + +int usbi_vsnprintf(char *str, size_t size, const char *format, va_list args) +{ + int ret; + + ret = _vsnprintf(str, size, format, args); + if (ret < 0 || ret == (int)size) { + /* Output is truncated, ensure buffer is NUL-terminated and + * determine how many characters would have been written. */ + str[size - 1] = '\0'; + if (ret < 0) + ret = _vsnprintf(NULL, 0, format, args); + } + + return ret; +} +#endif /* LIBUSB_PRINTF_WIN32 */ + +static void log_str(enum libusb_log_level level, const char *str) +{ +#if defined(USE_SYSTEM_LOGGING_FACILITY) +#if defined(__ANDROID__) + int priority; + switch (level) { + case LIBUSB_LOG_LEVEL_NONE: return; /* Impossible, but keeps compiler happy */ + case LIBUSB_LOG_LEVEL_ERROR: priority = ANDROID_LOG_ERROR; break; + case LIBUSB_LOG_LEVEL_WARNING: priority = ANDROID_LOG_WARN; break; + case LIBUSB_LOG_LEVEL_INFO: priority = ANDROID_LOG_INFO; break; + case LIBUSB_LOG_LEVEL_DEBUG: priority = ANDROID_LOG_DEBUG; break; + default: priority = ANDROID_LOG_UNKNOWN; + } + __android_log_write(priority, "libusb", str); +#elif defined(_WIN32) + UNUSED(level); + OutputDebugStringA(str); +#elif defined(HAVE_SYSLOG) + int syslog_level; + switch (level) { + case LIBUSB_LOG_LEVEL_NONE: return; /* Impossible, but keeps compiler happy */ + case LIBUSB_LOG_LEVEL_ERROR: syslog_level = LOG_ERR; break; + case LIBUSB_LOG_LEVEL_WARNING: syslog_level = LOG_WARNING; break; + case LIBUSB_LOG_LEVEL_INFO: syslog_level = LOG_INFO; break; + case LIBUSB_LOG_LEVEL_DEBUG: syslog_level = LOG_DEBUG; break; + default: syslog_level = LOG_INFO; + } + syslog(syslog_level, "%s", str); +#else /* All of gcc, Clang, Xcode seem to use #warning */ +#warning System logging is not supported on this platform. Logging to stderr will be used instead. + UNUSED(level); + fputs(str, stderr); +#endif +#else + /* Global log handler */ + if (log_handler) + log_handler(NULL, level, str); + else + fputs(str, stderr); +#endif /* USE_SYSTEM_LOGGING_FACILITY */ +} + +static void log_v(struct libusb_context *ctx, enum libusb_log_level level, + const char *function, const char *format, va_list args) +{ + const char *prefix; + char buf[USBI_MAX_LOG_LEN]; + int global_debug, header_len, text_len; + static int has_debug_header_been_displayed = 0; + +#ifdef ENABLE_DEBUG_LOGGING + global_debug = 1; + UNUSED(ctx); +#else + enum libusb_log_level ctx_level; + + ctx = usbi_get_context(ctx); + if (ctx) + ctx_level = ctx->debug; + else + ctx_level = get_env_debug_level(); + + if (ctx_level < level) + return; + + global_debug = (ctx_level == LIBUSB_LOG_LEVEL_DEBUG); +#endif + + switch (level) { + case LIBUSB_LOG_LEVEL_NONE: /* Impossible, but keeps compiler happy */ + return; + case LIBUSB_LOG_LEVEL_ERROR: + prefix = "error"; + break; + case LIBUSB_LOG_LEVEL_WARNING: + prefix = "warning"; + break; + case LIBUSB_LOG_LEVEL_INFO: + prefix = "info"; + break; + case LIBUSB_LOG_LEVEL_DEBUG: + prefix = "debug"; + break; + default: + prefix = "unknown"; + break; + } + + if (global_debug) { + struct timespec timestamp; + + if (!has_debug_header_been_displayed) { + has_debug_header_been_displayed = 1; + log_str(LIBUSB_LOG_LEVEL_DEBUG, "[timestamp] [threadID] facility level [function call] <message>" USBI_LOG_LINE_END); + log_str(LIBUSB_LOG_LEVEL_DEBUG, "--------------------------------------------------------------------------------" USBI_LOG_LINE_END); + } + + usbi_get_monotonic_time(×tamp); + TIMESPEC_SUB(×tamp, ×tamp_origin, ×tamp); + + header_len = snprintf(buf, sizeof(buf), + "[%2ld.%06ld] [%08x] libusb: %s [%s] ", + (long)timestamp.tv_sec, (long)(timestamp.tv_nsec / 1000L), usbi_get_tid(), prefix, function); + } else { + header_len = snprintf(buf, sizeof(buf), + "libusb: %s [%s] ", prefix, function); + } + + if (header_len < 0 || header_len >= (int)sizeof(buf)) { + /* Somehow snprintf() failed to write to the buffer, + * remove the header so something useful is output. */ + header_len = 0; + } + + text_len = vsnprintf(buf + header_len, sizeof(buf) - (size_t)header_len, + format, args); + if (text_len < 0 || text_len + header_len >= (int)sizeof(buf)) { + /* Truncated log output. On some platforms a -1 return value means + * that the output was truncated. */ + text_len = (int)sizeof(buf) - header_len; + } + if (header_len + text_len + (int)sizeof(USBI_LOG_LINE_END) >= (int)sizeof(buf)) { + /* Need to truncate the text slightly to fit on the terminator. */ + text_len -= (header_len + text_len + (int)sizeof(USBI_LOG_LINE_END)) - (int)sizeof(buf); + } + strcpy(buf + header_len + text_len, USBI_LOG_LINE_END); + + log_str(level, buf); + + /* Per-context log handler */ +#ifndef ENABLE_DEBUG_LOGGING + if (ctx && ctx->log_handler) + ctx->log_handler(ctx, level, buf); +#endif +} + +void usbi_log(struct libusb_context *ctx, enum libusb_log_level level, + const char *function, const char *format, ...) +{ + va_list args; + + va_start(args, format); + log_v(ctx, level, function, format, args); + va_end(args); +} + +#endif /* ENABLE_LOGGING */ + +/** \ingroup libusb_misc + * Returns a constant NULL-terminated string with the ASCII name of a libusb + * error or transfer status code. The caller must not free() the returned + * string. + * + * \param error_code The \ref libusb_error or libusb_transfer_status code to + * return the name of. + * \returns The error name, or the string **UNKNOWN** if the value of + * error_code is not a known error / status code. + */ +DEFAULT_VISIBILITY const char * LIBUSB_CALL libusb_error_name(int error_code) +{ + switch (error_code) { + case LIBUSB_ERROR_IO: + return "LIBUSB_ERROR_IO"; + case LIBUSB_ERROR_INVALID_PARAM: + return "LIBUSB_ERROR_INVALID_PARAM"; + case LIBUSB_ERROR_ACCESS: + return "LIBUSB_ERROR_ACCESS"; + case LIBUSB_ERROR_NO_DEVICE: + return "LIBUSB_ERROR_NO_DEVICE"; + case LIBUSB_ERROR_NOT_FOUND: + return "LIBUSB_ERROR_NOT_FOUND"; + case LIBUSB_ERROR_BUSY: + return "LIBUSB_ERROR_BUSY"; + case LIBUSB_ERROR_TIMEOUT: + return "LIBUSB_ERROR_TIMEOUT"; + case LIBUSB_ERROR_OVERFLOW: + return "LIBUSB_ERROR_OVERFLOW"; + case LIBUSB_ERROR_PIPE: + return "LIBUSB_ERROR_PIPE"; + case LIBUSB_ERROR_INTERRUPTED: + return "LIBUSB_ERROR_INTERRUPTED"; + case LIBUSB_ERROR_NO_MEM: + return "LIBUSB_ERROR_NO_MEM"; + case LIBUSB_ERROR_NOT_SUPPORTED: + return "LIBUSB_ERROR_NOT_SUPPORTED"; + case LIBUSB_ERROR_OTHER: + return "LIBUSB_ERROR_OTHER"; + + case LIBUSB_TRANSFER_ERROR: + return "LIBUSB_TRANSFER_ERROR"; + case LIBUSB_TRANSFER_TIMED_OUT: + return "LIBUSB_TRANSFER_TIMED_OUT"; + case LIBUSB_TRANSFER_CANCELLED: + return "LIBUSB_TRANSFER_CANCELLED"; + case LIBUSB_TRANSFER_STALL: + return "LIBUSB_TRANSFER_STALL"; + case LIBUSB_TRANSFER_NO_DEVICE: + return "LIBUSB_TRANSFER_NO_DEVICE"; + case LIBUSB_TRANSFER_OVERFLOW: + return "LIBUSB_TRANSFER_OVERFLOW"; + + case 0: + return "LIBUSB_SUCCESS / LIBUSB_TRANSFER_COMPLETED"; + default: + return "**UNKNOWN**"; + } +} + +/** \ingroup libusb_misc + * Returns a pointer to const struct libusb_version with the version + * (major, minor, micro, nano and rc) of the running library. + */ +DEFAULT_VISIBILITY +const struct libusb_version * LIBUSB_CALL libusb_get_version(void) +{ + return &libusb_version_internal; +} |