| /* |
| * Internal header for libusb |
| * Copyright © 2007-2009 Daniel Drake <dsd@gentoo.org> |
| * Copyright © 2001 Johannes Erdfelt <johannes@erdfelt.com> |
| * Copyright © 2019 Nathan Hjelm <hjelmn@cs.umm.edu> |
| * Copyright © 2019 Google LLC. All rights reserved. |
| * Copyright © 2020 Chris Dickens <christopher.a.dickens@gmail.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 |
| */ |
| |
| #ifndef LIBUSBI_H |
| #define LIBUSBI_H |
| |
| #include <config.h> |
| |
| #include <assert.h> |
| #include <stdarg.h> |
| #include <stddef.h> |
| #include <stdlib.h> |
| #ifdef HAVE_SYS_TIME_H |
| #include <sys/time.h> |
| #endif |
| |
| #include "libusb.h" |
| #include "version.h" |
| |
| #ifndef ARRAYSIZE |
| #define ARRAYSIZE(array) (sizeof(array) / sizeof(array[0])) |
| #endif |
| |
| #ifndef CLAMP |
| #define CLAMP(val, min, max) \ |
| ((val) < (min) ? (min) : ((val) > (max) ? (max) : (val))) |
| #endif |
| |
| #ifndef MIN |
| #define MIN(a, b) ((a) < (b) ? (a) : (b)) |
| #endif |
| |
| #ifndef MAX |
| #define MAX(a, b) ((a) > (b) ? (a) : (b)) |
| #endif |
| |
| /* The following is used to silence warnings for unused variables */ |
| #if defined(UNREFERENCED_PARAMETER) |
| #define UNUSED(var) UNREFERENCED_PARAMETER(var) |
| #else |
| #define UNUSED(var) do { (void)(var); } while(0) |
| #endif |
| |
| /* Attribute to ensure that a structure member is aligned to a natural |
| * pointer alignment. Used for os_priv member. */ |
| #if defined(_MSC_VER) |
| #if defined(_WIN64) |
| #define PTR_ALIGNED __declspec(align(8)) |
| #else |
| #define PTR_ALIGNED __declspec(align(4)) |
| #endif |
| #elif defined(__GNUC__) && (__GNUC__ >= 3) |
| #define PTR_ALIGNED __attribute__((aligned(sizeof(void *)))) |
| #else |
| #define PTR_ALIGNED |
| #endif |
| |
| /* Internal abstraction for poll */ |
| #if defined(OS_LINUX) || defined(OS_DARWIN) || defined(OS_OPENBSD) || defined(OS_NETBSD) || \ |
| defined(OS_HAIKU) || defined(OS_SUNOS) || defined(OS_NULL) |
| #include "os/poll_posix.h" |
| #elif defined(OS_WINDOWS) |
| #include "os/poll_windows.h" |
| #endif |
| |
| /* Internal abstraction for thread synchronization */ |
| #if defined(THREADS_POSIX) |
| #include "os/threads_posix.h" |
| #elif defined(OS_WINDOWS) |
| #include "os/threads_windows.h" |
| #endif |
| |
| /* Inside the libusb code, mark all public functions as follows: |
| * return_type API_EXPORTED function_name(params) { ... } |
| * But if the function returns a pointer, mark it as follows: |
| * DEFAULT_VISIBILITY return_type * LIBUSB_CALL function_name(params) { ... } |
| * In the libusb public header, mark all declarations as: |
| * return_type LIBUSB_CALL function_name(params); |
| */ |
| #define API_EXPORTED LIBUSB_CALL DEFAULT_VISIBILITY |
| |
| /* Macro to decorate printf-like functions, in order to get |
| * compiler warnings about format string mistakes. |
| */ |
| #if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 2) |
| #define USBI_PRINTFLIKE(formatarg, firstvararg) \ |
| __attribute__((__format__ (__printf__, formatarg, firstvararg))) |
| #else |
| #define USBI_PRINTFLIKE(formatarg, firstvararg) |
| #endif |
| |
| #ifdef __cplusplus |
| extern "C" { |
| #endif |
| |
| #define DEVICE_DESC_LENGTH 18 |
| |
| #define USB_MAXENDPOINTS 32 |
| #define USB_MAXINTERFACES 32 |
| #define USB_MAXCONFIG 8 |
| |
| /* Backend specific capabilities */ |
| #define USBI_CAP_HAS_HID_ACCESS 0x00010000 |
| #define USBI_CAP_SUPPORTS_DETACH_KERNEL_DRIVER 0x00020000 |
| |
| /* Maximum number of bytes in a log line */ |
| #define USBI_MAX_LOG_LEN 1024 |
| /* Terminator for log lines */ |
| #define USBI_LOG_LINE_END "\n" |
| |
| struct list_head { |
| struct list_head *prev, *next; |
| }; |
| |
| /* Get an entry from the list |
| * ptr - the address of this list_head element in "type" |
| * type - the data type that contains "member" |
| * member - the list_head element in "type" |
| */ |
| #define list_entry(ptr, type, member) \ |
| ((type *)((uintptr_t)(ptr) - (uintptr_t)offsetof(type, member))) |
| |
| #define list_first_entry(ptr, type, member) \ |
| list_entry((ptr)->next, type, member) |
| |
| /* Get each entry from a list |
| * pos - A structure pointer has a "member" element |
| * head - list head |
| * member - the list_head element in "pos" |
| * type - the type of the first parameter |
| */ |
| #define list_for_each_entry(pos, head, member, type) \ |
| for (pos = list_entry((head)->next, type, member); \ |
| &pos->member != (head); \ |
| pos = list_entry(pos->member.next, type, member)) |
| |
| #define list_for_each_entry_safe(pos, n, head, member, type) \ |
| for (pos = list_entry((head)->next, type, member), \ |
| n = list_entry(pos->member.next, type, member); \ |
| &pos->member != (head); \ |
| pos = n, n = list_entry(n->member.next, type, member)) |
| |
| #define list_empty(entry) ((entry)->next == (entry)) |
| |
| static inline void list_init(struct list_head *entry) |
| { |
| entry->prev = entry->next = entry; |
| } |
| |
| static inline void list_add(struct list_head *entry, struct list_head *head) |
| { |
| entry->next = head->next; |
| entry->prev = head; |
| |
| head->next->prev = entry; |
| head->next = entry; |
| } |
| |
| static inline void list_add_tail(struct list_head *entry, |
| struct list_head *head) |
| { |
| entry->next = head; |
| entry->prev = head->prev; |
| |
| head->prev->next = entry; |
| head->prev = entry; |
| } |
| |
| static inline void list_del(struct list_head *entry) |
| { |
| entry->next->prev = entry->prev; |
| entry->prev->next = entry->next; |
| entry->next = entry->prev = NULL; |
| } |
| |
| static inline void list_cut(struct list_head *list, struct list_head *head) |
| { |
| if (list_empty(head)) |
| return; |
| |
| list->next = head->next; |
| list->next->prev = list; |
| list->prev = head->prev; |
| list->prev->next = list; |
| |
| list_init(head); |
| } |
| |
| static inline void *usbi_reallocf(void *ptr, size_t size) |
| { |
| void *ret = realloc(ptr, size); |
| |
| if (!ret) |
| free(ptr); |
| return ret; |
| } |
| |
| #define TIMESPEC_IS_SET(ts) ((ts)->tv_sec != 0 || (ts)->tv_nsec != 0) |
| |
| #if defined(OS_WINDOWS) |
| #define TIMEVAL_TV_SEC_TYPE long |
| #else |
| #define TIMEVAL_TV_SEC_TYPE time_t |
| #endif |
| |
| /* Some platforms don't have this define */ |
| #ifndef TIMESPEC_TO_TIMEVAL |
| #define TIMESPEC_TO_TIMEVAL(tv, ts) \ |
| do { \ |
| (tv)->tv_sec = (TIMEVAL_TV_SEC_TYPE) (ts)->tv_sec; \ |
| (tv)->tv_usec = (ts)->tv_nsec / 1000L; \ |
| } while (0) |
| #endif |
| |
| #ifdef ENABLE_LOGGING |
| |
| #if defined(_MSC_VER) && (_MSC_VER < 1900) |
| #define snprintf usbi_snprintf |
| #define vsnprintf usbi_vsnprintf |
| int usbi_snprintf(char *dst, size_t size, const char *format, ...); |
| int usbi_vsnprintf(char *dst, size_t size, const char *format, va_list ap); |
| #define LIBUSB_PRINTF_WIN32 |
| #endif /* defined(_MSC_VER) && (_MSC_VER < 1900) */ |
| |
| void usbi_log(struct libusb_context *ctx, enum libusb_log_level level, |
| const char *function, const char *format, ...) USBI_PRINTFLIKE(4, 5); |
| |
| void usbi_log_v(struct libusb_context *ctx, enum libusb_log_level level, |
| const char *function, const char *format, va_list args) USBI_PRINTFLIKE(4, 0); |
| |
| #define _usbi_log(ctx, level, ...) usbi_log(ctx, level, __FUNCTION__, __VA_ARGS__) |
| |
| #define usbi_err(ctx, ...) _usbi_log(ctx, LIBUSB_LOG_LEVEL_ERROR, __VA_ARGS__) |
| #define usbi_warn(ctx, ...) _usbi_log(ctx, LIBUSB_LOG_LEVEL_WARNING, __VA_ARGS__) |
| #define usbi_info(ctx, ...) _usbi_log(ctx, LIBUSB_LOG_LEVEL_INFO, __VA_ARGS__) |
| #define usbi_dbg(...) _usbi_log(NULL, LIBUSB_LOG_LEVEL_DEBUG, __VA_ARGS__) |
| |
| #else /* ENABLE_LOGGING */ |
| |
| #define usbi_err(ctx, ...) UNUSED(ctx) |
| #define usbi_warn(ctx, ...) UNUSED(ctx) |
| #define usbi_info(ctx, ...) UNUSED(ctx) |
| #define usbi_dbg(...) do {} while (0) |
| |
| #endif /* ENABLE_LOGGING */ |
| |
| #define USBI_GET_CONTEXT(ctx) \ |
| do { \ |
| if (!(ctx)) \ |
| (ctx) = usbi_default_context; \ |
| } while(0) |
| |
| #define DEVICE_CTX(dev) ((dev)->ctx) |
| #define HANDLE_CTX(handle) (DEVICE_CTX((handle)->dev)) |
| #define TRANSFER_CTX(transfer) (HANDLE_CTX((transfer)->dev_handle)) |
| #define ITRANSFER_CTX(transfer) \ |
| (TRANSFER_CTX(USBI_TRANSFER_TO_LIBUSB_TRANSFER(transfer))) |
| |
| #define IS_EPIN(ep) (0 != ((ep) & LIBUSB_ENDPOINT_IN)) |
| #define IS_EPOUT(ep) (!IS_EPIN(ep)) |
| #define IS_XFERIN(xfer) (0 != ((xfer)->endpoint & LIBUSB_ENDPOINT_IN)) |
| #define IS_XFEROUT(xfer) (!IS_XFERIN(xfer)) |
| |
| struct libusb_context { |
| #if defined(ENABLE_LOGGING) && !defined(ENABLE_DEBUG_LOGGING) |
| enum libusb_log_level debug; |
| int debug_fixed; |
| libusb_log_cb log_handler; |
| #endif |
| |
| /* internal event pipe, used for signalling occurrence of an internal event. */ |
| int event_pipe[2]; |
| |
| struct list_head usb_devs; |
| usbi_mutex_t usb_devs_lock; |
| |
| /* A list of open handles. Backends are free to traverse this if required. |
| */ |
| struct list_head open_devs; |
| usbi_mutex_t open_devs_lock; |
| |
| /* A list of registered hotplug callbacks */ |
| struct list_head hotplug_cbs; |
| libusb_hotplug_callback_handle next_hotplug_cb_handle; |
| usbi_mutex_t hotplug_cbs_lock; |
| |
| /* this is a list of in-flight transfer handles, sorted by timeout |
| * expiration. URBs to timeout the soonest are placed at the beginning of |
| * the list, URBs that will time out later are placed after, and urbs with |
| * infinite timeout are always placed at the very end. */ |
| struct list_head flying_transfers; |
| /* Note paths taking both this and usbi_transfer->lock must always |
| * take this lock first */ |
| usbi_mutex_t flying_transfers_lock; |
| |
| /* user callbacks for pollfd changes */ |
| libusb_pollfd_added_cb fd_added_cb; |
| libusb_pollfd_removed_cb fd_removed_cb; |
| void *fd_cb_user_data; |
| |
| /* ensures that only one thread is handling events at any one time */ |
| usbi_mutex_t events_lock; |
| |
| /* used to see if there is an active thread doing event handling */ |
| int event_handler_active; |
| |
| /* A thread-local storage key to track which thread is performing event |
| * handling */ |
| usbi_tls_key_t event_handling_key; |
| |
| /* used to wait for event completion in threads other than the one that is |
| * event handling */ |
| usbi_mutex_t event_waiters_lock; |
| usbi_cond_t event_waiters_cond; |
| |
| /* A lock to protect internal context event data. */ |
| usbi_mutex_t event_data_lock; |
| |
| /* A bitmask of flags that are set to indicate specific events that need to |
| * be handled. Protected by event_data_lock. */ |
| unsigned int event_flags; |
| |
| /* A counter that is set when we want to interrupt and prevent event handling, |
| * in order to safely close a device. Protected by event_data_lock. */ |
| unsigned int device_close; |
| |
| /* list and count of poll fds and an array of poll fd structures that is |
| * (re)allocated as necessary prior to polling. Protected by event_data_lock. */ |
| struct list_head ipollfds; |
| /* list of pollfds that have been removed. keeps track of pollfd changes |
| * between the poll call and */ |
| struct list_head removed_ipollfds; |
| struct pollfd *pollfds; |
| POLL_NFDS_TYPE pollfds_cnt; |
| |
| /* A list of pending hotplug messages. Protected by event_data_lock. */ |
| struct list_head hotplug_msgs; |
| |
| /* A list of pending completed transfers. Protected by event_data_lock. */ |
| struct list_head completed_transfers; |
| |
| #ifdef USBI_TIMERFD_AVAILABLE |
| /* used for timeout handling, if supported by OS. |
| * this timerfd is maintained to trigger on the next pending timeout */ |
| int timerfd; |
| #endif |
| |
| struct list_head list; |
| |
| PTR_ALIGNED unsigned char os_priv[ZERO_SIZED_ARRAY]; |
| }; |
| |
| enum usbi_event_flags { |
| /* The list of pollfds has been modified */ |
| USBI_EVENT_POLLFDS_MODIFIED = 1U << 0, |
| |
| /* The user has interrupted the event handler */ |
| USBI_EVENT_USER_INTERRUPT = 1U << 1, |
| |
| /* A hotplug callback deregistration is pending */ |
| USBI_EVENT_HOTPLUG_CB_DEREGISTERED = 1U << 2, |
| }; |
| |
| /* Macros for managing event handling state */ |
| #define usbi_handling_events(ctx) \ |
| (usbi_tls_key_get((ctx)->event_handling_key) != NULL) |
| |
| #define usbi_start_event_handling(ctx) \ |
| usbi_tls_key_set((ctx)->event_handling_key, ctx) |
| |
| #define usbi_end_event_handling(ctx) \ |
| usbi_tls_key_set((ctx)->event_handling_key, NULL) |
| |
| /* Update the following macro if new event sources are added */ |
| #define usbi_pending_events(ctx) \ |
| ((ctx)->event_flags || (ctx)->device_close \ |
| || !list_empty(&(ctx)->hotplug_msgs) || !list_empty(&(ctx)->completed_transfers)) |
| |
| #ifdef USBI_TIMERFD_AVAILABLE |
| #define usbi_using_timerfd(ctx) ((ctx)->timerfd >= 0) |
| #else |
| #define usbi_using_timerfd(ctx) (0) |
| #endif |
| |
| struct libusb_device { |
| /* lock protects refcnt, everything else is finalized at initialization |
| * time */ |
| usbi_mutex_t lock; |
| int refcnt; |
| |
| struct libusb_context *ctx; |
| |
| uint8_t bus_number; |
| uint8_t port_number; |
| struct libusb_device* parent_dev; |
| uint8_t device_address; |
| uint8_t num_configurations; |
| enum libusb_speed speed; |
| |
| struct list_head list; |
| unsigned long session_data; |
| |
| struct libusb_device_descriptor device_descriptor; |
| int attached; |
| |
| PTR_ALIGNED unsigned char os_priv[ZERO_SIZED_ARRAY]; |
| }; |
| |
| struct libusb_device_handle { |
| /* lock protects claimed_interfaces */ |
| usbi_mutex_t lock; |
| unsigned long claimed_interfaces; |
| |
| struct list_head list; |
| struct libusb_device *dev; |
| int auto_detach_kernel_driver; |
| |
| PTR_ALIGNED unsigned char os_priv[ZERO_SIZED_ARRAY]; |
| }; |
| |
| enum { |
| USBI_CLOCK_MONOTONIC, |
| USBI_CLOCK_REALTIME |
| }; |
| |
| /* in-memory transfer layout: |
| * |
| * 1. struct usbi_transfer |
| * 2. struct libusb_transfer (which includes iso packets) [variable size] |
| * 3. os private data [variable size] |
| * |
| * from a libusb_transfer, you can get the usbi_transfer by rewinding the |
| * appropriate number of bytes. |
| * the usbi_transfer includes the number of allocated packets, so you can |
| * determine the size of the transfer and hence the start and length of the |
| * OS-private data. |
| */ |
| |
| struct usbi_transfer { |
| int num_iso_packets; |
| struct list_head list; |
| struct list_head completed_list; |
| struct timeval timeout; |
| int transferred; |
| uint32_t stream_id; |
| uint8_t state_flags; /* Protected by usbi_transfer->lock */ |
| uint8_t timeout_flags; /* Protected by the flying_stransfers_lock */ |
| |
| /* this lock is held during libusb_submit_transfer() and |
| * libusb_cancel_transfer() (allowing the OS backend to prevent duplicate |
| * cancellation, submission-during-cancellation, etc). the OS backend |
| * should also take this lock in the handle_events path, to prevent the user |
| * cancelling the transfer from another thread while you are processing |
| * its completion (presumably there would be races within your OS backend |
| * if this were possible). |
| * Note paths taking both this and the flying_transfers_lock must |
| * always take the flying_transfers_lock first */ |
| usbi_mutex_t lock; |
| }; |
| |
| enum usbi_transfer_state_flags { |
| /* Transfer successfully submitted by backend */ |
| USBI_TRANSFER_IN_FLIGHT = 1U << 0, |
| |
| /* Cancellation was requested via libusb_cancel_transfer() */ |
| USBI_TRANSFER_CANCELLING = 1U << 1, |
| |
| /* Operation on the transfer failed because the device disappeared */ |
| USBI_TRANSFER_DEVICE_DISAPPEARED = 1U << 2, |
| }; |
| |
| enum usbi_transfer_timeout_flags { |
| /* Set by backend submit_transfer() if the OS handles timeout */ |
| USBI_TRANSFER_OS_HANDLES_TIMEOUT = 1U << 0, |
| |
| /* The transfer timeout has been handled */ |
| USBI_TRANSFER_TIMEOUT_HANDLED = 1U << 1, |
| |
| /* The transfer timeout was successfully processed */ |
| USBI_TRANSFER_TIMED_OUT = 1U << 2, |
| }; |
| |
| #define USBI_TRANSFER_TO_LIBUSB_TRANSFER(transfer) \ |
| ((struct libusb_transfer *)(((unsigned char *)(transfer)) \ |
| + sizeof(struct usbi_transfer))) |
| #define LIBUSB_TRANSFER_TO_USBI_TRANSFER(transfer) \ |
| ((struct usbi_transfer *)(((unsigned char *)(transfer)) \ |
| - sizeof(struct usbi_transfer))) |
| |
| static inline void *usbi_transfer_get_os_priv(struct usbi_transfer *transfer) |
| { |
| assert(transfer->num_iso_packets >= 0); |
| return ((unsigned char *)transfer) + sizeof(struct usbi_transfer) |
| + sizeof(struct libusb_transfer) |
| + ((size_t)transfer->num_iso_packets |
| * sizeof(struct libusb_iso_packet_descriptor)); |
| } |
| |
| /* bus structures */ |
| |
| /* All standard descriptors have these 2 fields in common */ |
| struct usb_descriptor_header { |
| uint8_t bLength; |
| uint8_t bDescriptorType; |
| }; |
| |
| /* shared data and functions */ |
| |
| int usbi_io_init(struct libusb_context *ctx); |
| void usbi_io_exit(struct libusb_context *ctx); |
| |
| struct libusb_device *usbi_alloc_device(struct libusb_context *ctx, |
| unsigned long session_id); |
| struct libusb_device *usbi_get_device_by_session_id(struct libusb_context *ctx, |
| unsigned long session_id); |
| int usbi_sanitize_device(struct libusb_device *dev); |
| void usbi_handle_disconnect(struct libusb_device_handle *dev_handle); |
| |
| int usbi_handle_transfer_completion(struct usbi_transfer *itransfer, |
| enum libusb_transfer_status status); |
| int usbi_handle_transfer_cancellation(struct usbi_transfer *transfer); |
| void usbi_signal_transfer_completion(struct usbi_transfer *transfer); |
| |
| int usbi_parse_descriptor(const unsigned char *source, const char *descriptor, |
| void *dest, int host_endian); |
| int usbi_device_cache_descriptor(libusb_device *dev); |
| int usbi_get_config_index_by_value(struct libusb_device *dev, |
| uint8_t bConfigurationValue, int *idx); |
| |
| void usbi_connect_device(struct libusb_device *dev); |
| void usbi_disconnect_device(struct libusb_device *dev); |
| |
| int usbi_signal_event(struct libusb_context *ctx); |
| int usbi_clear_event(struct libusb_context *ctx); |
| |
| struct usbi_pollfd { |
| /* must come first */ |
| struct libusb_pollfd pollfd; |
| |
| struct list_head list; |
| }; |
| |
| int usbi_add_pollfd(struct libusb_context *ctx, int fd, short events); |
| void usbi_remove_pollfd(struct libusb_context *ctx, int fd); |
| |
| /* device discovery */ |
| |
| /* 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. */ |
| struct discovered_devs { |
| size_t len; |
| size_t capacity; |
| struct libusb_device *devices[ZERO_SIZED_ARRAY]; |
| }; |
| |
| struct discovered_devs *discovered_devs_append( |
| struct discovered_devs *discdevs, struct libusb_device *dev); |
| |
| /* OS abstraction */ |
| |
| /* This is the interface that OS backends need to implement. |
| * All fields are mandatory, except ones explicitly noted as optional. */ |
| struct usbi_os_backend { |
| /* A human-readable name for your backend, e.g. "Linux usbfs" */ |
| const char *name; |
| |
| /* Binary mask for backend specific capabilities */ |
| uint32_t caps; |
| |
| /* Perform initialization of your backend. You might use this function |
| * to determine specific capabilities of the system, allocate required |
| * data structures for later, etc. |
| * |
| * This function is called when a libusb user initializes the library |
| * prior to use. |
| * |
| * Return 0 on success, or a LIBUSB_ERROR code on failure. |
| */ |
| int (*init)(struct libusb_context *ctx); |
| |
| /* Deinitialization. Optional. This function should destroy anything |
| * that was set up by init. |
| * |
| * This function is called when the user deinitializes the library. |
| */ |
| void (*exit)(struct libusb_context *ctx); |
| |
| /* Set a backend-specific option. Optional. |
| * |
| * This function is called when the user calls libusb_set_option() and |
| * the option is not handled by the core library. |
| * |
| * Return 0 on success, or a LIBUSB_ERROR code on failure. |
| */ |
| int (*set_option)(struct libusb_context *ctx, enum libusb_option option, |
| va_list args); |
| |
| /* Enumerate all the USB devices on the system, returning them in a list |
| * of discovered devices. |
| * |
| * Your implementation should enumerate all devices on the system, |
| * regardless of whether they have been seen before or not. |
| * |
| * When you have found a device, compute a session ID for it. The session |
| * ID should uniquely represent that particular device for that particular |
| * connection session since boot (i.e. if you disconnect and reconnect a |
| * device immediately after, it should be assigned a different session ID). |
| * If your OS cannot provide a unique session ID as described above, |
| * presenting a session ID of (bus_number << 8 | device_address) should |
| * be sufficient. Bus numbers and device addresses wrap and get reused, |
| * but that is an unlikely case. |
| * |
| * After computing a session ID for a device, call |
| * usbi_get_device_by_session_id(). This function checks if libusb already |
| * knows about the device, and if so, it provides you with a reference |
| * to a libusb_device structure for it. |
| * |
| * If usbi_get_device_by_session_id() returns NULL, it is time to allocate |
| * a new device structure for the device. Call usbi_alloc_device() to |
| * obtain a new libusb_device structure with reference count 1. Populate |
| * the bus_number and device_address attributes of the new device, and |
| * perform any other internal backend initialization you need to do. At |
| * this point, you should be ready to provide device descriptors and so |
| * on through the get_*_descriptor functions. Finally, call |
| * usbi_sanitize_device() to perform some final sanity checks on the |
| * device. Assuming all of the above succeeded, we can now continue. |
| * If any of the above failed, remember to unreference the device that |
| * was returned by usbi_alloc_device(). |
| * |
| * At this stage we have a populated libusb_device structure (either one |
| * that was found earlier, or one that we have just allocated and |
| * populated). This can now be added to the discovered devices list |
| * using discovered_devs_append(). Note that discovered_devs_append() |
| * may reallocate the list, returning a new location for it, and also |
| * note that reallocation can fail. Your backend should handle these |
| * error conditions appropriately. |
| * |
| * This function should not generate any bus I/O and should not block. |
| * If I/O is required (e.g. reading the active configuration value), it is |
| * OK to ignore these suggestions :) |
| * |
| * This function is executed when the user wishes to retrieve a list |
| * of USB devices connected to the system. |
| * |
| * If the backend has hotplug support, this function is not used! |
| * |
| * Return 0 on success, or a LIBUSB_ERROR code on failure. |
| */ |
| int (*get_device_list)(struct libusb_context *ctx, |
| struct discovered_devs **discdevs); |
| |
| /* Apps which were written before hotplug support, may listen for |
| * hotplug events on their own and call libusb_get_device_list on |
| * device addition. In this case libusb_get_device_list will likely |
| * return a list without the new device in there, as the hotplug |
| * event thread will still be busy enumerating the device, which may |
| * take a while, or may not even have seen the event yet. |
| * |
| * To avoid this libusb_get_device_list will call this optional |
| * function for backends with hotplug support before copying |
| * ctx->usb_devs to the user. In this function the backend should |
| * ensure any pending hotplug events are fully processed before |
| * returning. |
| * |
| * Optional, should be implemented by backends with hotplug support. |
| */ |
| void (*hotplug_poll)(void); |
| |
| /* Wrap a platform-specific device handle for I/O and other USB |
| * operations. The device handle is preallocated for you. |
| * |
| * Your backend should allocate any internal resources required for I/O |
| * and other operations so that those operations can happen (hopefully) |
| * without hiccup. This is also a good place to inform libusb that it |
| * should monitor certain file descriptors related to this device - |
| * see the usbi_add_pollfd() function. |
| * |
| * Your backend should also initialize the device structure |
| * (dev_handle->dev), which is NULL at the beginning of the call. |
| * |
| * This function should not generate any bus I/O and should not block. |
| * |
| * This function is called when the user attempts to wrap an existing |
| * platform-specific device handle for a device. |
| * |
| * Return: |
| * - 0 on success |
| * - LIBUSB_ERROR_ACCESS if the user has insufficient permissions |
| * - another LIBUSB_ERROR code on other failure |
| * |
| * Do not worry about freeing the handle on failed open, the upper layers |
| * do this for you. |
| */ |
| int (*wrap_sys_device)(struct libusb_context *ctx, |
| struct libusb_device_handle *dev_handle, intptr_t sys_dev); |
| |
| /* Open a device for I/O and other USB operations. The device handle |
| * is preallocated for you, you can retrieve the device in question |
| * through handle->dev. |
| * |
| * Your backend should allocate any internal resources required for I/O |
| * and other operations so that those operations can happen (hopefully) |
| * without hiccup. This is also a good place to inform libusb that it |
| * should monitor certain file descriptors related to this device - |
| * see the usbi_add_pollfd() function. |
| * |
| * This function should not generate any bus I/O and should not block. |
| * |
| * This function is called when the user attempts to obtain a device |
| * handle for a device. |
| * |
| * Return: |
| * - 0 on success |
| * - LIBUSB_ERROR_ACCESS if the user has insufficient permissions |
| * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected since |
| * discovery |
| * - another LIBUSB_ERROR code on other failure |
| * |
| * Do not worry about freeing the handle on failed open, the upper layers |
| * do this for you. |
| */ |
| int (*open)(struct libusb_device_handle *dev_handle); |
| |
| /* Close a device such that the handle cannot be used again. Your backend |
| * should destroy any resources that were allocated in the open path. |
| * This may also be a good place to call usbi_remove_pollfd() to inform |
| * libusb of any file descriptors associated with this device that should |
| * no longer be monitored. |
| * |
| * This function is called when the user closes a device handle. |
| */ |
| void (*close)(struct libusb_device_handle *dev_handle); |
| |
| /* Retrieve the device descriptor from a device. |
| * |
| * The descriptor should be retrieved from memory, NOT via bus I/O to the |
| * device. This means that you may have to cache it in a private structure |
| * during get_device_list enumeration. Alternatively, you may be able |
| * to retrieve it from a kernel interface (some Linux setups can do this) |
| * still without generating bus I/O. |
| * |
| * This function is expected to write DEVICE_DESC_LENGTH (18) bytes into |
| * buffer, which is guaranteed to be big enough. |
| * |
| * This function is called when sanity-checking a device before adding |
| * it to the list of discovered devices, and also when the user requests |
| * to read the device descriptor. |
| * |
| * This function is expected to return the descriptor in bus-endian format |
| * (LE). If it returns the multi-byte values in host-endian format, |
| * set the host_endian output parameter to "1". |
| * |
| * Return 0 on success or a LIBUSB_ERROR code on failure. |
| */ |
| int (*get_device_descriptor)(struct libusb_device *device, |
| unsigned char *buffer, int *host_endian); |
| |
| /* Get the ACTIVE configuration descriptor for a device. |
| * |
| * The descriptor should be retrieved from memory, NOT via bus I/O to the |
| * device. This means that you may have to cache it in a private structure |
| * during get_device_list enumeration. You may also have to keep track |
| * of which configuration is active when the user changes it. |
| * |
| * This function is expected to write len bytes of data into buffer, which |
| * is guaranteed to be big enough. If you can only do a partial write, |
| * return an error code. |
| * |
| * This function is expected to return the descriptor in bus-endian format |
| * (LE). If it returns the multi-byte values in host-endian format, |
| * set the host_endian output parameter to "1". |
| * |
| * Return: |
| * - 0 on success |
| * - LIBUSB_ERROR_NOT_FOUND if the device is in unconfigured state |
| * - another LIBUSB_ERROR code on other failure |
| */ |
| int (*get_active_config_descriptor)(struct libusb_device *device, |
| unsigned char *buffer, size_t len, int *host_endian); |
| |
| /* Get a specific configuration descriptor for a device. |
| * |
| * The descriptor should be retrieved from memory, NOT via bus I/O to the |
| * device. This means that you may have to cache it in a private structure |
| * during get_device_list enumeration. |
| * |
| * The requested descriptor is expressed as a zero-based index (i.e. 0 |
| * indicates that we are requesting the first descriptor). The index does |
| * not (necessarily) equal the bConfigurationValue of the configuration |
| * being requested. |
| * |
| * This function is expected to write len bytes of data into buffer, which |
| * is guaranteed to be big enough. If you can only do a partial write, |
| * return an error code. |
| * |
| * This function is expected to return the descriptor in bus-endian format |
| * (LE). If it returns the multi-byte values in host-endian format, |
| * set the host_endian output parameter to "1". |
| * |
| * Return the length read on success or a LIBUSB_ERROR code on failure. |
| */ |
| int (*get_config_descriptor)(struct libusb_device *device, |
| uint8_t config_index, unsigned char *buffer, size_t len, |
| int *host_endian); |
| |
| /* Like get_config_descriptor but then by bConfigurationValue instead |
| * of by index. |
| * |
| * Optional, if not present the core will call get_config_descriptor |
| * for all configs until it finds the desired bConfigurationValue. |
| * |
| * Returns a pointer to the raw-descriptor in *buffer, this memory |
| * is valid as long as device is valid. |
| * |
| * Returns the length of the returned raw-descriptor on success, |
| * or a LIBUSB_ERROR code on failure. |
| */ |
| int (*get_config_descriptor_by_value)(struct libusb_device *device, |
| uint8_t bConfigurationValue, unsigned char **buffer, |
| int *host_endian); |
| |
| /* Get the bConfigurationValue for the active configuration for a device. |
| * Optional. This should only be implemented if you can retrieve it from |
| * cache (don't generate I/O). |
| * |
| * If you cannot retrieve this from cache, either do not implement this |
| * function, or return LIBUSB_ERROR_NOT_SUPPORTED. This will cause |
| * libusb to retrieve the information through a standard control transfer. |
| * |
| * This function must be non-blocking. |
| * Return: |
| * - 0 on success |
| * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected since it |
| * was opened |
| * - LIBUSB_ERROR_NOT_SUPPORTED if the value cannot be retrieved without |
| * blocking |
| * - another LIBUSB_ERROR code on other failure. |
| */ |
| int (*get_configuration)(struct libusb_device_handle *dev_handle, int *config); |
| |
| /* Set the active configuration for a device. |
| * |
| * A configuration value of -1 should put the device in unconfigured state. |
| * |
| * This function can block. |
| * |
| * Return: |
| * - 0 on success |
| * - LIBUSB_ERROR_NOT_FOUND if the configuration does not exist |
| * - LIBUSB_ERROR_BUSY if interfaces are currently claimed (and hence |
| * configuration cannot be changed) |
| * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected since it |
| * was opened |
| * - another LIBUSB_ERROR code on other failure. |
| */ |
| int (*set_configuration)(struct libusb_device_handle *dev_handle, int config); |
| |
| /* Claim an interface. When claimed, the application can then perform |
| * I/O to an interface's endpoints. |
| * |
| * This function should not generate any bus I/O and should not block. |
| * Interface claiming is a logical operation that simply ensures that |
| * no other drivers/applications are using the interface, and after |
| * claiming, no other drivers/applications can use the interface because |
| * we now "own" it. |
| * |
| * Return: |
| * - 0 on success |
| * - LIBUSB_ERROR_NOT_FOUND if the interface does not exist |
| * - LIBUSB_ERROR_BUSY if the interface is in use by another driver/app |
| * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected since it |
| * was opened |
| * - another LIBUSB_ERROR code on other failure |
| */ |
| int (*claim_interface)(struct libusb_device_handle *dev_handle, int interface_number); |
| |
| /* Release a previously claimed interface. |
| * |
| * This function should also generate a SET_INTERFACE control request, |
| * resetting the alternate setting of that interface to 0. It's OK for |
| * this function to block as a result. |
| * |
| * You will only ever be asked to release an interface which was |
| * successfully claimed earlier. |
| * |
| * Return: |
| * - 0 on success |
| * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected since it |
| * was opened |
| * - another LIBUSB_ERROR code on other failure |
| */ |
| int (*release_interface)(struct libusb_device_handle *dev_handle, int interface_number); |
| |
| /* Set the alternate setting for an interface. |
| * |
| * You will only ever be asked to set the alternate setting for an |
| * interface which was successfully claimed earlier. |
| * |
| * It's OK for this function to block. |
| * |
| * Return: |
| * - 0 on success |
| * - LIBUSB_ERROR_NOT_FOUND if the alternate setting does not exist |
| * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected since it |
| * was opened |
| * - another LIBUSB_ERROR code on other failure |
| */ |
| int (*set_interface_altsetting)(struct libusb_device_handle *dev_handle, |
| int interface_number, int altsetting); |
| |
| /* Clear a halt/stall condition on an endpoint. |
| * |
| * It's OK for this function to block. |
| * |
| * Return: |
| * - 0 on success |
| * - LIBUSB_ERROR_NOT_FOUND if the endpoint does not exist |
| * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected since it |
| * was opened |
| * - another LIBUSB_ERROR code on other failure |
| */ |
| int (*clear_halt)(struct libusb_device_handle *dev_handle, |
| unsigned char endpoint); |
| |
| /* Perform a USB port reset to reinitialize a device. |
| * |
| * If possible, the device handle should still be usable after the reset |
| * completes, assuming that the device descriptors did not change during |
| * reset and all previous interface state can be restored. |
| * |
| * If something changes, or you cannot easily locate/verify the resetted |
| * device, return LIBUSB_ERROR_NOT_FOUND. This prompts the application |
| * to close the old handle and re-enumerate the device. |
| * |
| * Return: |
| * - 0 on success |
| * - LIBUSB_ERROR_NOT_FOUND if re-enumeration is required, or if the device |
| * has been disconnected since it was opened |
| * - another LIBUSB_ERROR code on other failure |
| */ |
| int (*reset_device)(struct libusb_device_handle *dev_handle); |
| |
| /* Alloc num_streams usb3 bulk streams on the passed in endpoints */ |
| int (*alloc_streams)(struct libusb_device_handle *dev_handle, |
| uint32_t num_streams, unsigned char *endpoints, int num_endpoints); |
| |
| /* Free usb3 bulk streams allocated with alloc_streams */ |
| int (*free_streams)(struct libusb_device_handle *dev_handle, |
| unsigned char *endpoints, int num_endpoints); |
| |
| /* Allocate persistent DMA memory for the given device, suitable for |
| * zerocopy. May return NULL on failure. Optional to implement. |
| */ |
| unsigned char *(*dev_mem_alloc)(struct libusb_device_handle *handle, |
| size_t len); |
| |
| /* Free memory allocated by dev_mem_alloc. */ |
| int (*dev_mem_free)(struct libusb_device_handle *handle, |
| unsigned char *buffer, size_t len); |
| |
| /* Determine if a kernel driver is active on an interface. Optional. |
| * |
| * The presence of a kernel driver on an interface indicates that any |
| * calls to claim_interface would fail with the LIBUSB_ERROR_BUSY code. |
| * |
| * Return: |
| * - 0 if no driver is active |
| * - 1 if a driver is active |
| * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected since it |
| * was opened |
| * - another LIBUSB_ERROR code on other failure |
| */ |
| int (*kernel_driver_active)(struct libusb_device_handle *dev_handle, |
| int interface_number); |
| |
| /* Detach a kernel driver from an interface. Optional. |
| * |
| * After detaching a kernel driver, the interface should be available |
| * for claim. |
| * |
| * Return: |
| * - 0 on success |
| * - LIBUSB_ERROR_NOT_FOUND if no kernel driver was active |
| * - LIBUSB_ERROR_INVALID_PARAM if the interface does not exist |
| * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected since it |
| * was opened |
| * - another LIBUSB_ERROR code on other failure |
| */ |
| int (*detach_kernel_driver)(struct libusb_device_handle *dev_handle, |
| int interface_number); |
| |
| /* Attach a kernel driver to an interface. Optional. |
| * |
| * Reattach a kernel driver to the device. |
| * |
| * Return: |
| * - 0 on success |
| * - LIBUSB_ERROR_NOT_FOUND if no kernel driver was active |
| * - LIBUSB_ERROR_INVALID_PARAM if the interface does not exist |
| * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected since it |
| * was opened |
| * - LIBUSB_ERROR_BUSY if a program or driver has claimed the interface, |
| * preventing reattachment |
| * - another LIBUSB_ERROR code on other failure |
| */ |
| int (*attach_kernel_driver)(struct libusb_device_handle *dev_handle, |
| int interface_number); |
| |
| /* Destroy a device. Optional. |
| * |
| * This function is called when the last reference to a device is |
| * destroyed. It should free any resources allocated in the get_device_list |
| * path. |
| */ |
| void (*destroy_device)(struct libusb_device *dev); |
| |
| /* Submit a transfer. Your implementation should take the transfer, |
| * morph it into whatever form your platform requires, and submit it |
| * asynchronously. |
| * |
| * This function must not block. |
| * |
| * This function gets called with the flying_transfers_lock locked! |
| * |
| * Return: |
| * - 0 on success |
| * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected |
| * - another LIBUSB_ERROR code on other failure |
| */ |
| int (*submit_transfer)(struct usbi_transfer *itransfer); |
| |
| /* Cancel a previously submitted transfer. |
| * |
| * This function must not block. The transfer cancellation must complete |
| * later, resulting in a call to usbi_handle_transfer_cancellation() |
| * from the context of handle_events. |
| */ |
| int (*cancel_transfer)(struct usbi_transfer *itransfer); |
| |
| /* Clear a transfer as if it has completed or cancelled, but do not |
| * report any completion/cancellation to the library. You should free |
| * all private data from the transfer as if you were just about to report |
| * completion or cancellation. |
| * |
| * This function might seem a bit out of place. It is used when libusb |
| * detects a disconnected device - it calls this function for all pending |
| * transfers before reporting completion (with the disconnect code) to |
| * the user. Maybe we can improve upon this internal interface in future. |
| */ |
| void (*clear_transfer_priv)(struct usbi_transfer *itransfer); |
| |
| /* Handle any pending events on file descriptors. Optional. |
| * |
| * Provide this function when file descriptors directly indicate device |
| * or transfer activity. If your backend does not have such file descriptors, |
| * implement the handle_transfer_completion function below. |
| * |
| * This involves monitoring any active transfers and processing their |
| * completion or cancellation. |
| * |
| * The function is passed an array of pollfd structures (size nfds) |
| * as a result of the poll() system call. The num_ready parameter |
| * indicates the number of file descriptors that have reported events |
| * (i.e. the poll() return value). This should be enough information |
| * for you to determine which actions need to be taken on the currently |
| * active transfers. |
| * |
| * For any cancelled transfers, call usbi_handle_transfer_cancellation(). |
| * For completed transfers, call usbi_handle_transfer_completion(). |
| * For control/bulk/interrupt transfers, populate the "transferred" |
| * element of the appropriate usbi_transfer structure before calling the |
| * above functions. For isochronous transfers, populate the status and |
| * transferred fields of the iso packet descriptors of the transfer. |
| * |
| * This function should also be able to detect disconnection of the |
| * device, reporting that situation with usbi_handle_disconnect(). |
| * |
| * When processing an event related to a transfer, you probably want to |
| * take usbi_transfer.lock to prevent races. See the documentation for |
| * the usbi_transfer structure. |
| * |
| * Return 0 on success, or a LIBUSB_ERROR code on failure. |
| */ |
| int (*handle_events)(struct libusb_context *ctx, |
| struct pollfd *fds, POLL_NFDS_TYPE nfds, int num_ready); |
| |
| /* Handle transfer completion. Optional. |
| * |
| * Provide this function when there are no file descriptors available |
| * that directly indicate device or transfer activity. If your backend does |
| * have such file descriptors, implement the handle_events function above. |
| * |
| * Your backend must tell the library when a transfer has completed by |
| * calling usbi_signal_transfer_completion(). You should store any private |
| * information about the transfer and its completion status in the transfer's |
| * private backend data. |
| * |
| * During event handling, this function will be called on each transfer for |
| * which usbi_signal_transfer_completion() was called. |
| * |
| * For any cancelled transfers, call usbi_handle_transfer_cancellation(). |
| * For completed transfers, call usbi_handle_transfer_completion(). |
| * For control/bulk/interrupt transfers, populate the "transferred" |
| * element of the appropriate usbi_transfer structure before calling the |
| * above functions. For isochronous transfers, populate the status and |
| * transferred fields of the iso packet descriptors of the transfer. |
| * |
| * Return 0 on success, or a LIBUSB_ERROR code on failure. |
| */ |
| int (*handle_transfer_completion)(struct usbi_transfer *itransfer); |
| |
| /* Get time from specified clock. At least two clocks must be implemented |
| by the backend: USBI_CLOCK_REALTIME, and USBI_CLOCK_MONOTONIC. |
| |
| Description of clocks: |
| USBI_CLOCK_REALTIME : clock returns time since system epoch. |
| USBI_CLOCK_MONOTONIC: clock returns time since unspecified start |
| time (usually boot). |
| */ |
| int (*clock_gettime)(int clkid, struct timespec *tp); |
| |
| #ifdef USBI_TIMERFD_AVAILABLE |
| /* clock ID of the clock that should be used for timerfd */ |
| clockid_t (*get_timerfd_clockid)(void); |
| #endif |
| |
| /* Number of bytes to reserve for per-context private backend data. |
| * This private data area is accessible through the "os_priv" field of |
| * struct libusb_context. */ |
| size_t context_priv_size; |
| |
| /* Number of bytes to reserve for per-device private backend data. |
| * This private data area is accessible through the "os_priv" field of |
| * struct libusb_device. */ |
| size_t device_priv_size; |
| |
| /* Number of bytes to reserve for per-handle private backend data. |
| * This private data area is accessible through the "os_priv" field of |
| * struct libusb_device. */ |
| size_t device_handle_priv_size; |
| |
| /* Number of bytes to reserve for per-transfer private backend data. |
| * This private data area is accessible by calling |
| * usbi_transfer_get_os_priv() on the appropriate usbi_transfer instance. |
| */ |
| size_t transfer_priv_size; |
| }; |
| |
| extern const struct usbi_os_backend usbi_backend; |
| |
| extern struct list_head active_contexts_list; |
| extern usbi_mutex_static_t active_contexts_lock; |
| |
| extern struct libusb_context *usbi_default_context; |
| |
| #ifdef __cplusplus |
| } |
| #endif |
| |
| #endif |