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Diffstat (limited to 'libusb-1.0/libusb/core.c')
| -rw-r--r-- | libusb-1.0/libusb/core.c | 1738 |
1 files changed, 0 insertions, 1738 deletions
diff --git a/libusb-1.0/libusb/core.c b/libusb-1.0/libusb/core.c deleted file mode 100644 index 46c2b9c..0000000 --- a/libusb-1.0/libusb/core.c +++ /dev/null @@ -1,1738 +0,0 @@ -/* - * Core functions for libusb - * Copyright (C) 2007-2008 Daniel Drake <dsd@gentoo.org> - * Copyright (c) 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 <config.h> - -#include <errno.h> -#include <stdarg.h> -#include <stdio.h> -#include <stdlib.h> -#include <string.h> -#include <sys/types.h> - -#include "libusbi.h" - -#if defined(OS_LINUX) -const struct usbi_os_backend * const usbi_backend = &linux_usbfs_backend; -#elif defined(OS_DARWIN) -const struct usbi_os_backend * const usbi_backend = &darwin_backend; -#elif defined(OS_WINDOWS) -const struct usbi_os_backend * const usbi_backend = &windows_backend; -#else -#error "Unsupported OS" -#endif - -struct libusb_context *usbi_default_context = NULL; -const struct libusb_version libusb_version_internal = { LIBUSB_VERSION_MAJOR, -LIBUSB_VERSION_MINOR, LIBUSB_VERSION_MICRO, LIBUSB_VERSION_NANO}; -static int default_context_refcnt = 0; -static usbi_mutex_static_t default_context_lock = USBI_MUTEX_INITIALIZER; - -/** - * \mainpage libusb-1.0 API Reference - * - * \section intro Introduction - * - * libusb is an open source library that allows you to communicate with USB - * devices from userspace. For more info, see the - * <a href="http://libusb.sourceforge.net">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://sourceforge.net/mail/?group_id=1674">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 2.0 - * Specification</a> which is available for free download. You can probably - * find less verbose introductions by searching the web. - * - * \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 - * - * \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 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 misc "miscellaneous" documentation page. - * - * \section msglog Debug message logging - * - * libusb does not log any messages by default. Your application is therefore - * free to close stdout/stderr and those descriptors may be reused without - * worry. - * - * The libusb_set_debug() function can be used to enable stdout/stderr logging - * of certain messages. Under standard configuration, libusb doesn't really - * log much at all, so you are advised to use this function to enable all - * error/warning/informational messages. It will help you 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 suitable for 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 number, which is - * interpreted the same as the libusb_set_debug() parameter. When this - * environment variable is set, the message logging verbosity level is fixed - * and libusb_set_debug() effectively does nothing. - * - * libusb can be compiled without any logging functions, useful for embedded - * systems. In this case, libusb_set_debug() and the LIBUSB_DEBUG environment - * variable have no effects. - * - * libusb can also be compiled with verbose debugging messages. When the - * library is compiled in this way, all messages of all verbosities are always - * logged. libusb_set_debug() and the LIBUSB_DEBUG environment variable have - * no effects. - * - * \section remarks Other remarks - * - * libusb does have imperfections. The \ref caveats "caveats" page attempts - * to document these. - */ - -/** - * \page caveats Caveats - * - * \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 userspace. - * 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 userspace. - * - * \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 nohotplug No hotplugging - * - * libusb-1.0 lacks functionality for providing notifications of when devices - * are added or removed. This functionality is planned to be implemented - * for libusb-1.1. - * - * That said, there is basic disconnection handling for open device handles: - * - If there are ongoing transfers, libusb's handle_events loop will detect - * disconnections and complete ongoing transfers with the - * LIBUSB_TRANSFER_NO_DEVICE status code. - * - Many functions such as libusb_set_configuration() return the special - * LIBUSB_ERROR_NO_DEVICE error code when the device has been disconnected. - * - * \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. - * -# libusb will be unable to change configuration if the device is in - * another configuration and other programs or drivers have claimed - * interfaces under that configuration. - * -# 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.) - * - * 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 = libusb_get_configuration(dev); -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. Prior to - * libusb v1.0.2, this information was lost (and for device-to-host transfers, - * the corresponding data was discarded). As of libusb v1.0.3, 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. - * - * A previous workaround was to only ever submit transfers of size 16kb or - * less. - * - * As of libusb v1.0.4 and Linux v2.6.32, this is fixed. A technical - * explanation of this issue follows. - * - * When you ask libusb to submit a bulk transfer larger than 16kb in size, - * libusb breaks it up into a number of smaller subtransfers. This is because - * the usbfs kernel interface only accepts transfers of up to 16kb in size. - * The subtransfers are submitted all at once so that the kernel can queue - * them at the hardware level, therefore maximizing bus throughput. - * - * On legacy platforms, this caused problems when transfers completed early. - * Upon this event, the kernel would terminate all further packets in that - * subtransfer (but not any following ones). libusb would note this event and - * immediately cancel any following subtransfers that had been queued, - * but often libusb was not fast enough, and the following subtransfers had - * started before libusb got around to cancelling them. - * - * Thanks to an API extension to usbfs, this is fixed with recent kernel and - * libusb releases. The solution was to allow libusb to communicate to the - * kernel where boundaries occur between logical libusb-level transfers. When - * a short transfer (or other error) occurs, the kernel will cancel all the - * subtransfers until the boundary without allowing those transfers to start. - */ - -/** - * \page 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_debug() 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. - */ - -/** - * @defgroup 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 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. - * - * 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(). - * -# 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 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 8 - -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; -} - -/* 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; - - /* 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("need to increase capacity"); - capacity = discdevs->capacity + DISCOVERED_DEVICES_SIZE_STEP; - discdevs = realloc(discdevs, - sizeof(*discdevs) + (sizeof(void *) * capacity)); - if (discdevs) { - discdevs->capacity = capacity; - discdevs->devices[len] = libusb_ref_device(dev); - discdevs->len++; - } - - return discdevs; -} - -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); -} - -/* 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 = malloc(sizeof(*dev) + priv_size); - int r; - - if (!dev) - return NULL; - - r = usbi_mutex_init(&dev->lock, NULL); - if (r) { - free(dev); - return NULL; - } - - dev->ctx = ctx; - dev->refcnt = 1; - dev->session_data = session_id; - memset(&dev->os_priv, 0, priv_size); - - usbi_mutex_lock(&ctx->usb_devs_lock); - list_add(&dev->list, &ctx->usb_devs); - usbi_mutex_unlock(&ctx->usb_devs_lock); - return dev; -} - -/* 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) -{ - int r; - unsigned char raw_desc[DEVICE_DESC_LENGTH]; - uint8_t num_configurations; - int host_endian; - - r = usbi_backend->get_device_descriptor(dev, raw_desc, &host_endian); - if (r < 0) - return r; - - num_configurations = raw_desc[DEVICE_DESC_LENGTH - 1]; - if (num_configurations > USB_MAXCONFIG) { - usbi_err(DEVICE_CTX(dev), "too many configurations"); - return LIBUSB_ERROR_IO; - } else if (num_configurations < 1) { - usbi_dbg("no configurations?"); - return LIBUSB_ERROR_IO; - } - - dev->num_configurations = num_configurations; - 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); - list_for_each_entry(dev, &ctx->usb_devs, list, struct libusb_device) - if (dev->session_data == session_id) { - ret = dev; - break; - } - usbi_mutex_unlock(&ctx->usb_devs_lock); - - return ret; -} - -/** @ingroup 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 LIBUSB_ERROR_NO_MEM - * on memory allocation failure. - */ -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_GET_CONTEXT(ctx); - usbi_dbg(""); - - if (!discdevs) - return LIBUSB_ERROR_NO_MEM; - - r = usbi_backend->get_device_list(ctx, &discdevs); - if (r < 0) { - len = r; - goto out; - } - - /* convert discovered_devs into a list */ - len = discdevs->len; - ret = malloc(sizeof(void *) * (len + 1)); - 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: - discovered_devs_free(discdevs); - return len; -} - -/** \ingroup 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 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 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; -} - -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 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) - return LIBUSB_ERROR_NOT_FOUND; - - r = ep->wMaxPacketSize; - libusb_free_config_descriptor(config); - return r; -} - -/** \ingroup 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 configution 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. - * - * 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; - enum libusb_transfer_type ep_type; - uint16_t val; - 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) - return LIBUSB_ERROR_NOT_FOUND; - - val = ep->wMaxPacketSize; - ep_type = ep->bmAttributes & 0x3; - libusb_free_config_descriptor(config); - - r = val & 0x07ff; - if (ep_type == LIBUSB_TRANSFER_TYPE_ISOCHRONOUS - || ep_type == LIBUSB_TRANSFER_TYPE_INTERRUPT) - r *= (1 + ((val >> 11) & 3)); - return r; -} - -/** \ingroup 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) -{ - usbi_mutex_lock(&dev->lock); - dev->refcnt++; - usbi_mutex_unlock(&dev->lock); - return dev; -} - -/** \ingroup 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) -{ - int refcnt; - - if (!dev) - return; - - usbi_mutex_lock(&dev->lock); - refcnt = --dev->refcnt; - usbi_mutex_unlock(&dev->lock); - - if (refcnt == 0) { - usbi_dbg("destroy device %d.%d", dev->bus_number, dev->device_address); - - if (usbi_backend->destroy_device) - usbi_backend->destroy_device(dev); - - usbi_mutex_lock(&dev->ctx->usb_devs_lock); - list_del(&dev->list); - usbi_mutex_unlock(&dev->ctx->usb_devs_lock); - - usbi_mutex_destroy(&dev->lock); - free(dev); - } -} - -/* - * Interrupt the iteration of the event handling thread, so that it picks - * up the new fd. - */ -void usbi_fd_notification(struct libusb_context *ctx) -{ - unsigned char dummy = 1; - ssize_t r; - - if (ctx == NULL) - return; - - /* record that we are messing with poll fds */ - usbi_mutex_lock(&ctx->pollfd_modify_lock); - ctx->pollfd_modify++; - usbi_mutex_unlock(&ctx->pollfd_modify_lock); - - /* write some data on control pipe to interrupt event handlers */ - r = usbi_write(ctx->ctrl_pipe[1], &dummy, sizeof(dummy)); - if (r <= 0) { - usbi_warn(ctx, "internal signalling write failed"); - usbi_mutex_lock(&ctx->pollfd_modify_lock); - ctx->pollfd_modify--; - usbi_mutex_unlock(&ctx->pollfd_modify_lock); - return; - } - - /* take event handling lock */ - libusb_lock_events(ctx); - - /* read the dummy data */ - r = usbi_read(ctx->ctrl_pipe[0], &dummy, sizeof(dummy)); - if (r <= 0) - usbi_warn(ctx, "internal signalling read failed"); - - /* we're done with modifying poll fds */ - usbi_mutex_lock(&ctx->pollfd_modify_lock); - ctx->pollfd_modify--; - usbi_mutex_unlock(&ctx->pollfd_modify_lock); - - /* Release event handling lock and wake up event waiters */ - libusb_unlock_events(ctx); -} - -/** \ingroup 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 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 **handle) -{ - struct libusb_context *ctx = DEVICE_CTX(dev); - struct libusb_device_handle *_handle; - size_t priv_size = usbi_backend->device_handle_priv_size; - int r; - usbi_dbg("open %d.%d", dev->bus_number, dev->device_address); - - _handle = malloc(sizeof(*_handle) + priv_size); - if (!_handle) - return LIBUSB_ERROR_NO_MEM; - - r = usbi_mutex_init(&_handle->lock, NULL); - if (r) { - free(_handle); - return LIBUSB_ERROR_OTHER; - } - - _handle->dev = libusb_ref_device(dev); - _handle->claimed_interfaces = 0; - memset(&_handle->os_priv, 0, priv_size); - - r = usbi_backend->open(_handle); - if (r < 0) { - libusb_unref_device(dev); - usbi_mutex_destroy(&_handle->lock); - free(_handle); - return r; - } - - usbi_mutex_lock(&ctx->open_devs_lock); - list_add(&_handle->list, &ctx->open_devs); - usbi_mutex_unlock(&ctx->open_devs_lock); - *handle = _handle; - - /* At this point, we want to interrupt any existing event handlers so - * that they realise the addition of the new device's poll fd. One - * example when this is desirable is if the user is running a separate - * dedicated libusb events handling thread, which is running with a long - * or infinite timeout. We want to interrupt that iteration of the loop, - * so that it picks up the new fd, and then continues. */ - usbi_fd_notification(ctx); - - return 0; -} - -/** \ingroup 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 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 *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, &handle); - if (r < 0) - handle = NULL; - } - -out: - libusb_free_device_list(devs, 1); - return handle; -} - -static void do_close(struct libusb_context *ctx, - struct libusb_device_handle *dev_handle) -{ - 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 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 handle to close - */ -void API_EXPORTED libusb_close(libusb_device_handle *dev_handle) -{ - struct libusb_context *ctx; - unsigned char dummy = 1; - ssize_t r; - - if (!dev_handle) - return; - usbi_dbg(""); - - ctx = HANDLE_CTX(dev_handle); - - /* 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. */ - - /* record that we are messing with poll fds */ - usbi_mutex_lock(&ctx->pollfd_modify_lock); - ctx->pollfd_modify++; - usbi_mutex_unlock(&ctx->pollfd_modify_lock); - - /* write some data on control pipe to interrupt event handlers */ - r = usbi_write(ctx->ctrl_pipe[1], &dummy, sizeof(dummy)); - if (r <= 0) { - usbi_warn(ctx, "internal signalling write failed, closing anyway"); - do_close(ctx, dev_handle); - usbi_mutex_lock(&ctx->pollfd_modify_lock); - ctx->pollfd_modify--; - usbi_mutex_unlock(&ctx->pollfd_modify_lock); - return; - } - - /* take event handling lock */ - libusb_lock_events(ctx); - - /* read the dummy data */ - r = usbi_read(ctx->ctrl_pipe[0], &dummy, sizeof(dummy)); - if (r <= 0) - usbi_warn(ctx, "internal signalling read failed, closing anyway"); - - /* Close the device */ - do_close(ctx, dev_handle); - - /* we're done with modifying poll fds */ - usbi_mutex_lock(&ctx->pollfd_modify_lock); - ctx->pollfd_modify--; - usbi_mutex_unlock(&ctx->pollfd_modify_lock); - - /* Release event handling lock and wake up event waiters */ - libusb_unlock_events(ctx); -} - -/** \ingroup dev - * Get the underlying device for a 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 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 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, - int *config) -{ - int r = LIBUSB_ERROR_NOT_SUPPORTED; - - usbi_dbg(""); - if (usbi_backend->get_configuration) - r = usbi_backend->get_configuration(dev, config); - - if (r == LIBUSB_ERROR_NOT_SUPPORTED) { - uint8_t tmp = 0; - usbi_dbg("falling back to control message"); - r = libusb_control_transfer(dev, LIBUSB_ENDPOINT_IN, - LIBUSB_REQUEST_GET_CONFIGURATION, 0, 0, &tmp, 1, 1000); - if (r == 0) { - usbi_err(HANDLE_CTX(dev), "zero bytes returned in ctrl transfer?"); - r = LIBUSB_ERROR_IO; - } else if (r == 1) { - r = 0; - *config = tmp; - } else { - usbi_dbg("control failed, error %d", r); - } - } - - if (r == 0) - usbi_dbg("active config %d", *config); - - return r; -} - -/** \ingroup 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). - * - * You cannot change/reset configuration if your application has claimed - * interfaces - you should free them with libusb_release_interface() first. - * 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 a device handle - * \param configuration the bConfigurationValue of the configuration you - * wish to activate, or -1 if you wish to put the device in 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_NO_DEVICE if the device has been disconnected - * \returns another LIBUSB_ERROR code on other failure - */ -int API_EXPORTED libusb_set_configuration(libusb_device_handle *dev, - int configuration) -{ - usbi_dbg("configuration %d", configuration); - return usbi_backend->set_configuration(dev, configuration); -} - -/** \ingroup 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. - * - * 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 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 - */ -int API_EXPORTED libusb_claim_interface(libusb_device_handle *dev, - int interface_number) -{ - int r = 0; - - usbi_dbg("interface %d", interface_number); - if (interface_number >= sizeof(dev->claimed_interfaces) * 8) - return LIBUSB_ERROR_INVALID_PARAM; - - usbi_mutex_lock(&dev->lock); - if (dev->claimed_interfaces & (1 << interface_number)) - goto out; - - r = usbi_backend->claim_interface(dev, interface_number); - if (r == 0) - dev->claimed_interfaces |= 1 << interface_number; - -out: - usbi_mutex_unlock(&dev->lock); - return r; -} - -/** \ingroup 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. - * - * \param dev 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 - */ -int API_EXPORTED libusb_release_interface(libusb_device_handle *dev, - int interface_number) -{ - int r; - - usbi_dbg("interface %d", interface_number); - if (interface_number >= sizeof(dev->claimed_interfaces) * 8) - return LIBUSB_ERROR_INVALID_PARAM; - - usbi_mutex_lock(&dev->lock); - if (!(dev->claimed_interfaces & (1 << interface_number))) { - r = LIBUSB_ERROR_NOT_FOUND; - goto out; - } - - r = usbi_backend->release_interface(dev, interface_number); - if (r == 0) - dev->claimed_interfaces &= ~(1 << interface_number); - -out: - usbi_mutex_unlock(&dev->lock); - return r; -} - -/** \ingroup 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 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, - int interface_number, int alternate_setting) -{ - usbi_dbg("interface %d altsetting %d", - interface_number, alternate_setting); - if (interface_number >= sizeof(dev->claimed_interfaces) * 8) - return LIBUSB_ERROR_INVALID_PARAM; - - usbi_mutex_lock(&dev->lock); - if (!(dev->claimed_interfaces & (1 << interface_number))) { - usbi_mutex_unlock(&dev->lock); - return LIBUSB_ERROR_NOT_FOUND; - } - usbi_mutex_unlock(&dev->lock); - - return usbi_backend->set_interface_altsetting(dev, interface_number, - alternate_setting); -} - -/** \ingroup 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 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, - unsigned char endpoint) -{ - usbi_dbg("endpoint %x", endpoint); - return usbi_backend->clear_halt(dev, endpoint); -} - -/** \ingroup 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 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) -{ - usbi_dbg(""); - return usbi_backend->reset_device(dev); -} - -/** \ingroup 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 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, - int interface_number) -{ - usbi_dbg("interface %d", interface_number); - if (usbi_backend->kernel_driver_active) - return usbi_backend->kernel_driver_active(dev, interface_number); - else - return LIBUSB_ERROR_NOT_SUPPORTED; -} - -/** \ingroup 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 Darwin or Windows. - * - * \param dev 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, - int interface_number) -{ - usbi_dbg("interface %d", interface_number); - if (usbi_backend->detach_kernel_driver) - return usbi_backend->detach_kernel_driver(dev, interface_number); - else - return LIBUSB_ERROR_NOT_SUPPORTED; -} - -/** \ingroup dev - * Re-attach an interface's kernel driver, which was previously detached - * using libusb_detach_kernel_driver(). This call is only effective on - * Linux and returns LIBUSB_ERROR_NOT_SUPPORTED on all other platforms. - * - * This functionality is not available on Darwin or Windows. - * - * \param dev 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, - int interface_number) -{ - usbi_dbg("interface %d", interface_number); - if (usbi_backend->attach_kernel_driver) - return usbi_backend->attach_kernel_driver(dev, interface_number); - else - return LIBUSB_ERROR_NOT_SUPPORTED; -} - -/** \ingroup lib - * Set message verbosity. - * - Level 0: no messages ever printed by the library (default) - * - Level 1: error messages are printed to stderr - * - Level 2: warning and error messages are printed to stderr - * - Level 3: informational messages are printed to stdout, warning and error - * messages are printed to stderr - * - * The default level is 0, which means no messages are ever printed. If you - * choose to increase the message verbosity level, ensure that your - * application does not close the stdout/stderr file descriptors. - * - * You are advised to set level 3. libusb is conservative with its message - * logging and most of the time, will only log messages that explain error - * conditions and other oddities. This will help you debug your software. - * - * If the LIBUSB_DEBUG environment variable was set when libusb was - * initialized, this function does nothing: the message verbosity is fixed - * to the value in the environment variable. - * - * If libusb was compiled without any message logging, this function does - * nothing: you'll never get any messages. - * - * If libusb was compiled with verbose debug message logging, this function - * does nothing: you'll always get messages from all levels. - * - * \param ctx the context to operate on, or NULL for the default context - * \param level debug level to set - */ -void API_EXPORTED libusb_set_debug(libusb_context *ctx, int level) -{ - USBI_GET_CONTEXT(ctx); - if (!ctx->debug_fixed) - ctx->debug = level; -} - -/** \ingroup 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 context Optional output location for context pointer. - * Only valid on return code 0. - * \returns 0 on success, or a LIBUSB_ERROR code on failure - * \see contexts - */ -int API_EXPORTED libusb_init(libusb_context **context) -{ - char *dbg = getenv("LIBUSB_DEBUG"); - struct libusb_context *ctx; - int r; - - usbi_mutex_static_lock(&default_context_lock); - if (!context && usbi_default_context) { - r = 0; - usbi_dbg("reusing default context"); - default_context_refcnt++; - usbi_mutex_static_unlock(&default_context_lock); - return 0; - } - - ctx = malloc(sizeof(*ctx)); - if (!ctx) { - r = LIBUSB_ERROR_NO_MEM; - goto err_unlock; - } - memset(ctx, 0, sizeof(*ctx)); - - if (dbg) { - ctx->debug = atoi(dbg); - if (ctx->debug) - ctx->debug_fixed = 1; - } - - // default context should be initialized before any call to usbi_dbg - if (!usbi_default_context) { - usbi_default_context = ctx; - usbi_dbg("created default context"); - } - - usbi_dbg(""); - - if (usbi_backend->init) { - r = usbi_backend->init(ctx); - if (r) - goto err_free_ctx; - } - - usbi_mutex_init(&ctx->usb_devs_lock, NULL); - usbi_mutex_init(&ctx->open_devs_lock, NULL); - list_init(&ctx->usb_devs); - list_init(&ctx->open_devs); - - r = usbi_io_init(ctx); - if (r < 0) { - if (usbi_backend->exit) - usbi_backend->exit(); - goto err_destroy_mutex; - } - - if (context) { - *context = ctx; - } else if (!usbi_default_context) { - usbi_dbg("created default context"); - usbi_default_context = ctx; - default_context_refcnt++; - } - usbi_mutex_static_unlock(&default_context_lock); - - return 0; - -err_destroy_mutex: - if (usbi_default_context == ctx) - usbi_default_context = NULL; - usbi_mutex_destroy(&ctx->open_devs_lock); - usbi_mutex_destroy(&ctx->usb_devs_lock); -err_free_ctx: - free(ctx); -err_unlock: - usbi_mutex_static_unlock(&default_context_lock); - return r; -} - -/** \ingroup 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(struct libusb_context *ctx) -{ - USBI_GET_CONTEXT(ctx); - usbi_dbg(""); - - /* if working with default context, only actually do the deinitialization - * if we're the last user */ - if (ctx == usbi_default_context) { - usbi_mutex_static_lock(&default_context_lock); - if (--default_context_refcnt > 0) { - usbi_dbg("not destroying default context"); - usbi_mutex_static_unlock(&default_context_lock); - return; - } - usbi_dbg("destroying default context"); - usbi_default_context = NULL; - usbi_mutex_static_unlock(&default_context_lock); - } - - /* a little sanity check. doesn't bother with open_devs locking because - * unless there is an application bug, nobody will be accessing this. */ - if (!list_empty(&ctx->open_devs)) - usbi_warn(ctx, "application left some devices open"); - - usbi_io_exit(ctx); - if (usbi_backend->exit) - usbi_backend->exit(); - - usbi_mutex_destroy(&ctx->open_devs_lock); - usbi_mutex_destroy(&ctx->usb_devs_lock); - free(ctx); -} - -void usbi_log_v(struct libusb_context *ctx, enum usbi_log_level level, - const char *function, const char *format, va_list args) -{ - FILE *stream = stdout; - const char *prefix; - -#ifndef ENABLE_DEBUG_LOGGING - USBI_GET_CONTEXT(ctx); - if (ctx == NULL) - return; - if (!ctx->debug) - return; - if (level == LOG_LEVEL_WARNING && ctx->debug < 2) - return; - if (level == LOG_LEVEL_INFO && ctx->debug < 3) - return; - if (level == LOG_LEVEL_DEBUG && ctx->debug < 4) - return; -#endif - - switch (level) { - case LOG_LEVEL_INFO: - prefix = "info"; - break; - case LOG_LEVEL_WARNING: - stream = stderr; - prefix = "warning"; - break; - case LOG_LEVEL_ERROR: - stream = stderr; - prefix = "error"; - break; - case LOG_LEVEL_DEBUG: - stream = stderr; - prefix = "debug"; - break; - default: - stream = stderr; - prefix = "unknown"; - break; - } - - fprintf(stream, "libusb:%s [%s] ", prefix, function); - - vfprintf(stream, format, args); - - fprintf(stream, "\n"); -} - -void usbi_log(struct libusb_context *ctx, enum usbi_log_level level, - const char *function, const char *format, ...) -{ - va_list args; - - va_start (args, format); - usbi_log_v(ctx, level, function, format, args); - va_end (args); -} - -/** \ingroup misc - * Returns a constant NULL-terminated string with an English short description - * of the given error code. The caller should never free() the returned pointer - * since it points to a constant string. - * The returned string is encoded in ASCII form and always starts with a - * capital letter and ends without any punctuation. - * Future versions of libusb may return NULL if the library is compiled without - * these messages included (e.g. for embedded systems). - * This function is intended to be used for debugging purposes only. - * - * \param errcode the error code whose description is desired - * \returns a short description of the error code in English, or NULL if the - * error descriptions are unavailable - */ -DEFAULT_VISIBILITY -const char * LIBUSB_CALL libusb_strerror(enum libusb_error error_code) -{ - switch (error_code) { - case LIBUSB_SUCCESS: - return "Success"; - case LIBUSB_ERROR_IO: - return "Input/output error"; - case LIBUSB_ERROR_INVALID_PARAM: - return "Invalid parameter"; - case LIBUSB_ERROR_ACCESS: - return "Access denied (insufficient permissions)"; - case LIBUSB_ERROR_NO_DEVICE: - return "No such device (it may have been disconnected)"; - case LIBUSB_ERROR_NOT_FOUND: - return "Entity not found"; - case LIBUSB_ERROR_BUSY: - return "Resource busy"; - case LIBUSB_ERROR_TIMEOUT: - return "Operation timed out"; - case LIBUSB_ERROR_OVERFLOW: - return "Overflow"; - case LIBUSB_ERROR_PIPE: - return "Pipe error"; - case LIBUSB_ERROR_INTERRUPTED: - return "System call interrupted (perhaps due to signal)"; - case LIBUSB_ERROR_NO_MEM: - return "Insufficient memory"; - case LIBUSB_ERROR_NOT_SUPPORTED: - return "Operation not supported or unimplemented on this platform"; - case LIBUSB_ERROR_OTHER: - return "Other error"; - } - return "Unknown error"; -} - -/** \ingroup misc - * Fills a libusb_version struct with the full version (major, minor, - * micro, nano) of this library - */ -DEFAULT_VISIBILITY -const struct libusb_version * LIBUSB_CALL libusb_getversion(void) -{ - return &libusb_version_internal; -} |