/* -*- 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 "config.h"
#include <errno.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_TIME_H
#include <sys/time.h>
#endif
#ifdef HAVE_SYSLOG_H
#include <syslog.h>
#endif
#ifdef __ANDROID__
#include <android/log.h>
#endif
#include "libusbi.h"
#include "hotplug.h"
struct libusb_context *usbi_default_context = NULL;
static const struct libusb_version libusb_version_internal =
{ LIBUSB_MAJOR, LIBUSB_MINOR, LIBUSB_MICRO, LIBUSB_NANO,
LIBUSB_RC, "http://libusb.info" };
static int default_context_refcnt = 0;
static usbi_mutex_static_t default_context_lock = USBI_MUTEX_INITIALIZER;
static struct timespec timestamp_origin = { 0, 0 };
#ifndef USE_SYSTEM_LOGGING_FACILITY
static libusb_log_cb log_handler = NULL;
#endif
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 userspace. 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 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 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 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 only supported on Linux.
*/
/**
* \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_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.
*
* 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 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 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;
}
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("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, sizeof(*dev) + priv_size);
int r;
if (!dev)
return NULL;
r = usbi_mutex_init(&dev->lock);
if (r) {
free(dev);
return NULL;
}
dev->ctx = ctx;
dev->refcnt = 1;
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);
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);
/* Signal that an event has occurred for this device if we support hotplug AND
* the hotplug message list is ready. This prevents an event from getting raised
* during initial enumeration. */
if (libusb_has_capability(LIBUSB_CAP_HAS_HOTPLUG) && dev->ctx->hotplug_msgs.next) {
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_mutex_lock(&dev->lock);
dev->attached = 0;
usbi_mutex_unlock(&dev->lock);
usbi_mutex_lock(&ctx->usb_devs_lock);
list_del(&dev->list);
usbi_mutex_unlock(&ctx->usb_devs_lock);
/* Signal that an event has occurred for this device if we support hotplug AND
* the hotplug message list is ready. This prevents an event from getting raised
* during initial enumeration. libusb_handle_events will take care of dereferencing
* the device. */
if (libusb_has_capability(LIBUSB_CAP_HAS_HOTPLUG) && dev->ctx->hotplug_msgs.next) {
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)
{
int r;
uint8_t num_configurations;
r = usbi_device_cache_descriptor(dev);
if (r < 0)
return r;
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("zero configurations, maybe an unauthorized device");
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 = 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_GET_CONTEXT(ctx);
usbi_dbg(" ");
if (!discdevs)
return LIBUSB_ERROR_NO_MEM;
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);
list_for_each_entry(dev, &ctx->usb_devs, list, struct libusb_device) {
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 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_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_transfer_type) (ep->bmAttributes & 0x3);
r = val & 0x07ff;
if (ep_type == LIBUSB_TRANSFER_TYPE_ISOCHRONOUS
|| ep_type == LIBUSB_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)
{
usbi_mutex_lock(&dev->lock);
dev->refcnt++;
usbi_mutex_unlock(&dev->lock);
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)
{
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);
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);
}
usbi_mutex_destroy(&dev->lock);
free(dev);
}
}
/*
* Signal the event pipe so that the event handling thread will be
* interrupted to process an internal event.
*/
int usbi_signal_event(struct libusb_context *ctx)
{
unsigned char dummy = 1;
ssize_t r;
/* write some data on event pipe to interrupt event handlers */
r = usbi_write(ctx->event_pipe[1], &dummy, sizeof(dummy));
if (r != sizeof(dummy)) {
usbi_warn(ctx, "internal signalling write failed");
return LIBUSB_ERROR_IO;
}
return 0;
}
/*
* Clear the event pipe so that the event handling will no longer be
* interrupted.
*/
int usbi_clear_event(struct libusb_context *ctx)
{
unsigned char dummy;
ssize_t r;
/* read some data on event pipe to clear it */
r = usbi_read(ctx->event_pipe[0], &dummy, sizeof(dummy));
if (r != sizeof(dummy)) {
usbi_warn(ctx, "internal signalling read failed");
return LIBUSB_ERROR_IO;
}
return 0;
}
/** \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.
*
* 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.
*
* \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("wrap_sys_device %p", (void *)sys_dev);
USBI_GET_CONTEXT(ctx);
if (!usbi_backend.wrap_sys_device)
return LIBUSB_ERROR_NOT_SUPPORTED;
_dev_handle = malloc(sizeof(*_dev_handle) + priv_size);
if (!_dev_handle)
return LIBUSB_ERROR_NO_MEM;
r = usbi_mutex_init(&_dev_handle->lock);
if (r) {
free(_dev_handle);
return LIBUSB_ERROR_OTHER;
}
_dev_handle->dev = NULL;
_dev_handle->auto_detach_kernel_driver = 0;
_dev_handle->claimed_interfaces = 0;
memset(&_dev_handle->os_priv, 0, priv_size);
r = usbi_backend.wrap_sys_device(ctx, _dev_handle, sys_dev);
if (r < 0) {
usbi_dbg("wrap_sys_device %p returns %d", (void *)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("open %d.%d", dev->bus_number, dev->device_address);
if (!dev->attached) {
return LIBUSB_ERROR_NO_DEVICE;
}
_dev_handle = malloc(sizeof(*_dev_handle) + priv_size);
if (!_dev_handle)
return LIBUSB_ERROR_NO_MEM;
r = usbi_mutex_init(&_dev_handle->lock);
if (r) {
free(_dev_handle);
return LIBUSB_ERROR_OTHER;
}
_dev_handle->dev = libusb_ref_device(dev);
_dev_handle->auto_detach_kernel_driver = 0;
_dev_handle->claimed_interfaces = 0;
memset(&_dev_handle->os_priv, 0, priv_size);
r = usbi_backend.open(_dev_handle);
if (r < 0) {
usbi_dbg("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 */
list_for_each_entry_safe(itransfer, tmp, &ctx->flying_transfers, list, struct usbi_transfer) {
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("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;
int handling_events;
int pending_events;
if (!dev_handle)
return;
usbi_dbg(" ");
ctx = HANDLE_CTX(dev_handle);
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);
pending_events = usbi_pending_events(ctx);
ctx->device_close++;
if (!pending_events)
usbi_signal_event(ctx);
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);
ctx->device_close--;
pending_events = usbi_pending_events(ctx);
if (!pending_events)
usbi_clear_event(ctx);
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;
usbi_dbg(" ");
if (usbi_backend.get_configuration)
r = usbi_backend.get_configuration(dev_handle, config);
if (r == LIBUSB_ERROR_NOT_SUPPORTED) {
uint8_t tmp = 0;
usbi_dbg("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 == 0) {
usbi_err(HANDLE_CTX(dev_handle), "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 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).
*
* 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_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("configuration %d", configuration);
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("interface %d", interface_number);
if (interface_number >= USB_MAXINTERFACES)
return LIBUSB_ERROR_INVALID_PARAM;
if (!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, 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("interface %d", interface_number);
if (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, 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("interface %d altsetting %d",
interface_number, alternate_setting);
if (interface_number >= USB_MAXINTERFACES)
return LIBUSB_ERROR_INVALID_PARAM;
usbi_mutex_lock(&dev_handle->lock);
if (!dev_handle->dev->attached) {
usbi_mutex_unlock(&dev_handle->lock);
return LIBUSB_ERROR_NO_DEVICE;
}
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, interface_number,
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("endpoint %x", endpoint);
if (!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(" ");
if (!dev_handle->dev->attached)
return LIBUSB_ERROR_NO_DEVICE;
return usbi_backend.reset_device(dev_handle);
}
/** \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("streams %u eps %d", (unsigned) num_streams, num_endpoints);
if (!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("eps %d", num_endpoints);
if (!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 zerocopy
* 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 (!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("interface %d", interface_number);
if (!dev_handle->dev->attached)
return LIBUSB_ERROR_NO_DEVICE;
if (usbi_backend.kernel_driver_active)
return usbi_backend.kernel_driver_active(dev_handle, 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 Darwin or 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("interface %d", interface_number);
if (!dev_handle->dev->attached)
return LIBUSB_ERROR_NO_DEVICE;
if (usbi_backend.detach_kernel_driver)
return usbi_backend.detach_kernel_driver(dev_handle, 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 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_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("interface %d", interface_number);
if (!dev_handle->dev->attached)
return LIBUSB_ERROR_NO_DEVICE;
if (usbi_backend.attach_kernel_driver)
return usbi_backend.attach_kernel_driver(dev_handle, 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)
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.
*
* \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(USE_SYSTEM_LOGGING_FACILITY)
if (mode & LIBUSB_LOG_CB_GLOBAL) {
log_handler = cb;
}
#endif
#if defined(ENABLE_LOGGING) && !defined(ENABLE_DEBUG_LOGGING)
if (mode & LIBUSB_LOG_CB_CONTEXT) {
USBI_GET_CONTEXT(ctx);
ctx->log_handler = cb;
}
#else
UNUSED(ctx);
#if defined(USE_SYSTEM_LOGGING_FACILITY)
UNUSED(cb);
UNUSED(mode);
#endif
#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.
*
* 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
*/
int API_EXPORTED libusb_set_option(libusb_context *ctx,
enum libusb_option option, ...)
{
int arg, r = LIBUSB_SUCCESS;
va_list ap;
USBI_GET_CONTEXT(ctx);
va_start(ap, option);
switch (option) {
case LIBUSB_OPTION_LOG_LEVEL:
arg = va_arg(ap, int);
if (arg < LIBUSB_LOG_LEVEL_NONE || arg > LIBUSB_LOG_LEVEL_DEBUG) {
r = LIBUSB_ERROR_INVALID_PARAM;
break;
}
#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:
if (usbi_backend.set_option)
r = usbi_backend.set_option(ctx, option, ap);
else
r = LIBUSB_ERROR_NOT_SUPPORTED;
break;
default:
r = LIBUSB_ERROR_INVALID_PARAM;
}
va_end(ap);
return r;
}
#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 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 libusb_contexts
*/
int API_EXPORTED libusb_init(libusb_context **context)
{
struct libusb_device *dev, *next;
size_t priv_size = usbi_backend.context_priv_size;
struct libusb_context *ctx;
static int first_init = 1;
int r = 0;
usbi_mutex_static_lock(&default_context_lock);
if (!timestamp_origin.tv_sec) {
usbi_backend.clock_gettime(USBI_CLOCK_REALTIME, ×tamp_origin);
}
if (!context && usbi_default_context) {
usbi_dbg("reusing default context");
default_context_refcnt++;
usbi_mutex_static_unlock(&default_context_lock);
return 0;
}
ctx = calloc(1, sizeof(*ctx) + priv_size);
if (!ctx) {
r = LIBUSB_ERROR_NO_MEM;
goto err_unlock;
}
#if defined(ENABLE_LOGGING) && !defined(ENABLE_DEBUG_LOGGING)
ctx->debug = get_env_debug_level();
if (ctx->debug != LIBUSB_LOG_LEVEL_NONE)
ctx->debug_fixed = 1;
#endif
/* default context should be initialized before calling usbi_dbg */
if (!usbi_default_context) {
usbi_default_context = ctx;
default_context_refcnt++;
usbi_dbg("created default context");
}
usbi_dbg("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);
usbi_mutex_init(&ctx->usb_devs_lock);
usbi_mutex_init(&ctx->open_devs_lock);
usbi_mutex_init(&ctx->hotplug_cbs_lock);
list_init(&ctx->usb_devs);
list_init(&ctx->open_devs);
list_init(&ctx->hotplug_cbs);
ctx->next_hotplug_cb_handle = 1;
usbi_mutex_static_lock(&active_contexts_lock);
if (first_init) {
first_init = 0;
list_init(&active_contexts_list);
}
list_add (&ctx->list, &active_contexts_list);
usbi_mutex_static_unlock(&active_contexts_lock);
if (usbi_backend.init) {
r = usbi_backend.init(ctx);
if (r)
goto err_free_ctx;
}
r = usbi_io_init(ctx);
if (r < 0)
goto err_backend_exit;
usbi_mutex_static_unlock(&default_context_lock);
if (context)
*context = ctx;
return 0;
err_backend_exit:
if (usbi_backend.exit)
usbi_backend.exit(ctx);
err_free_ctx:
if (ctx == usbi_default_context) {
usbi_default_context = NULL;
default_context_refcnt--;
}
usbi_mutex_static_lock(&active_contexts_lock);
list_del(&ctx->list);
usbi_mutex_static_unlock(&active_contexts_lock);
usbi_mutex_lock(&ctx->usb_devs_lock);
list_for_each_entry_safe(dev, next, &ctx->usb_devs, list, struct libusb_device) {
list_del(&dev->list);
libusb_unref_device(dev);
}
usbi_mutex_unlock(&ctx->usb_devs_lock);
usbi_mutex_destroy(&ctx->open_devs_lock);
usbi_mutex_destroy(&ctx->usb_devs_lock);
usbi_mutex_destroy(&ctx->hotplug_cbs_lock);
free(ctx);
err_unlock:
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(struct libusb_context *ctx)
{
struct libusb_device *dev, *next;
struct timeval tv = { 0, 0 };
int destroying_default_context = 0;
usbi_dbg(" ");
USBI_GET_CONTEXT(ctx);
/* if working with default context, only actually do the deinitialization
* if we're the last user */
usbi_mutex_static_lock(&default_context_lock);
if (ctx == usbi_default_context) {
if (!usbi_default_context) {
usbi_dbg("no default context, not initialized?");
usbi_mutex_static_unlock(&default_context_lock);
return;
}
if (--default_context_refcnt > 0) {
usbi_dbg("not destroying default context");
usbi_mutex_static_unlock(&default_context_lock);
return;
}
usbi_dbg("destroying default context");
/*
* Setting this flag without unlocking the default context, as
* we are actually destroying the default context.
* usbi_default_context is not set to NULL yet, as all activities
* would only stop after usbi_backend->exit() returns.
*/
destroying_default_context = 1;
} else {
/* Unlock default context, as we're not modifying it. */
usbi_mutex_static_unlock(&default_context_lock);
}
usbi_mutex_static_lock(&active_contexts_lock);
list_del(&ctx->list);
usbi_mutex_static_unlock(&active_contexts_lock);
if (libusb_has_capability(LIBUSB_CAP_HAS_HOTPLUG)) {
usbi_hotplug_deregister(ctx, 1);
/*
* Ensure any pending unplug events are read from the hotplug
* pipe. The usb_device-s hold in the events are no longer part
* of usb_devs, but the events still hold a reference!
*
* Note we don't do this if the application has left devices
* open (which implies a buggy app) to avoid packet completion
* handlers running when the app does not expect them to run.
*/
if (list_empty(&ctx->open_devs))
libusb_handle_events_timeout(ctx, &tv);
usbi_mutex_lock(&ctx->usb_devs_lock);
list_for_each_entry_safe(dev, next, &ctx->usb_devs, list, struct libusb_device) {
list_del(&dev->list);
libusb_unref_device(dev);
}
usbi_mutex_unlock(&ctx->usb_devs_lock);
}
/* a few sanity checks. don't bother with locking because unless
* there is an application bug, nobody will be accessing these. */
if (!list_empty(&ctx->usb_devs))
usbi_warn(ctx, "some libusb_devices were leaked");
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(ctx);
usbi_mutex_destroy(&ctx->open_devs_lock);
usbi_mutex_destroy(&ctx->usb_devs_lock);
usbi_mutex_destroy(&ctx->hotplug_cbs_lock);
free(ctx);
if (destroying_default_context) {
usbi_default_context = NULL;
usbi_mutex_static_unlock(&default_context_lock);
}
}
/** \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 NULL-terminated output.
* Microsoft did provide a _snprintf() function, but again it did not
* guarantee NULL-terminated output.
*
* The below implementations guarantee NULL-terminated output and are
* C99 compliant.
*/
int usbi_snprintf(char *str, size_t size, const char *format, ...)
{
va_list ap;
int ret;
va_start(ap, format);
ret = usbi_vsnprintf(str, size, format, ap);
va_end(ap);
return ret;
}
int usbi_vsnprintf(char *str, size_t size, const char *format, va_list ap)
{
int ret;
ret = _vsnprintf(str, size, format, ap);
if (ret < 0 || ret == (int)size) {
/* Output is truncated, ensure buffer is NULL-terminated and
* determine how many characters would have been written. */
str[size - 1] = '\0';
if (ret < 0)
ret = _vsnprintf(NULL, 0, format, ap);
}
return ret;
}
#endif /* LIBUSB_PRINTF_WIN32 */
static void usbi_log_str(enum libusb_log_level level, const char *str)
{
#if defined(USE_SYSTEM_LOGGING_FACILITY)
#if defined(OS_WINDOWS) || defined(OS_WINCE)
#if !defined(UNICODE)
OutputDebugStringA(str);
#else
WCHAR wbuf[USBI_MAX_LOG_LEN];
if (MultiByteToWideChar(CP_UTF8, 0, str, -1, wbuf, sizeof(wbuf)) != 0)
OutputDebugStringW(wbuf);
#endif
#elif defined(__ANDROID__)
int priority = ANDROID_LOG_UNKNOWN;
switch (level) {
case LIBUSB_LOG_LEVEL_NONE: return;
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;
}
__android_log_write(priority, "libusb", str);
#elif defined(HAVE_SYSLOG_FUNC)
int syslog_level = LOG_INFO;
switch (level) {
case LIBUSB_LOG_LEVEL_NONE: return;
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;
}
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.
fputs(str, stderr);
#endif
#else
/* Global log handler */
if (log_handler != NULL)
log_handler(NULL, level, str);
else
fputs(str, stderr);
#endif /* USE_SYSTEM_LOGGING_FACILITY */
UNUSED(level);
}
void usbi_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];
struct timespec now;
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 = LIBUSB_LOG_LEVEL_NONE;
USBI_GET_CONTEXT(ctx);
if (ctx)
ctx_level = ctx->debug;
else
ctx_level = get_env_debug_level();
if (ctx_level == LIBUSB_LOG_LEVEL_NONE)
return;
if (level == LIBUSB_LOG_LEVEL_WARNING && ctx_level < LIBUSB_LOG_LEVEL_WARNING)
return;
if (level == LIBUSB_LOG_LEVEL_INFO && ctx_level < LIBUSB_LOG_LEVEL_INFO)
return;
if (level == LIBUSB_LOG_LEVEL_DEBUG && ctx_level < LIBUSB_LOG_LEVEL_DEBUG)
return;
global_debug = (ctx_level == LIBUSB_LOG_LEVEL_DEBUG);
#endif
usbi_backend.clock_gettime(USBI_CLOCK_REALTIME, &now);
if ((global_debug) && (!has_debug_header_been_displayed)) {
has_debug_header_been_displayed = 1;
usbi_log_str(LIBUSB_LOG_LEVEL_DEBUG, "[timestamp] [threadID] facility level [function call] <message>" USBI_LOG_LINE_END);
usbi_log_str(LIBUSB_LOG_LEVEL_DEBUG, "--------------------------------------------------------------------------------" USBI_LOG_LINE_END);
}
if (now.tv_nsec < timestamp_origin.tv_nsec) {
now.tv_sec--;
now.tv_nsec += 1000000000L;
}
now.tv_sec -= timestamp_origin.tv_sec;
now.tv_nsec -= timestamp_origin.tv_nsec;
switch (level) {
case LIBUSB_LOG_LEVEL_NONE:
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) {
header_len = snprintf(buf, sizeof(buf),
"[%2ld.%06ld] [%08x] libusb: %s [%s] ",
(long)now.tv_sec, (long)(now.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;
}
/* Make sure buffer is NUL terminated */
buf[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);
usbi_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);
usbi_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;
}