/* * Internal header for libusb * Copyright © 2007-2009 Daniel Drake * Copyright © 2001 Johannes Erdfelt * Copyright © 2019 Nathan Hjelm * Copyright © 2019-2020 Google LLC. All rights reserved. * Copyright © 2020 Chris Dickens * * 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 #include #include #include #include #ifdef HAVE_SYS_TIME_H #include #endif #include "libusb.h" /* Not all C standard library headers define static_assert in assert.h * Additionally, Visual Studio treats static_assert as a keyword. */ #if !defined(__cplusplus) && !defined(static_assert) && !defined(_MSC_VER) #define static_assert(cond, msg) _Static_assert(cond, msg) #endif #ifdef NDEBUG #define ASSERT_EQ(expression, value) (void)expression #define ASSERT_NE(expression, value) (void)expression #else #define ASSERT_EQ(expression, value) assert(expression == value) #define ASSERT_NE(expression, value) assert(expression != value) #endif #define container_of(ptr, type, member) \ ((type *)((uintptr_t)(ptr) - (uintptr_t)offsetof(type, member))) #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 /* Macro to align a value up to the next multiple of the size of a pointer */ #define PTR_ALIGN(v) \ (((v) + (sizeof(void *) - 1)) & ~(sizeof(void *) - 1)) /* Atomic operations * * Useful for reference counting or when accessing a value without a lock * * The following atomic operations are defined: * usbi_atomic_load() - Atomically read a variable's value * usbi_atomic_store() - Atomically write a new value value to a variable * usbi_atomic_inc() - Atomically increment a variable's value and return the new value * usbi_atomic_dec() - Atomically decrement a variable's value and return the new value * * All of these operations are ordered with each other, thus the effects of * any one operation is guaranteed to be seen by any other operation. */ #ifdef _MSC_VER typedef volatile LONG usbi_atomic_t; #define usbi_atomic_load(a) (*(a)) #define usbi_atomic_store(a, v) (*(a)) = (v) #define usbi_atomic_inc(a) InterlockedIncrement((a)) #define usbi_atomic_dec(a) InterlockedDecrement((a)) #else #include typedef atomic_long usbi_atomic_t; #define usbi_atomic_load(a) atomic_load((a)) #define usbi_atomic_store(a, v) atomic_store((a), (v)) #define usbi_atomic_inc(a) (atomic_fetch_add((a), 1) + 1) #define usbi_atomic_dec(a) (atomic_fetch_add((a), -1) - 1) #endif /* Internal abstractions for event handling and thread synchronization */ #if defined(PLATFORM_POSIX) #include "os/events_posix.h" #include "os/threads_posix.h" #elif defined(PLATFORM_WINDOWS) #include "os/events_windows.h" #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 #ifdef __cplusplus extern "C" { #endif #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) \ container_of(ptr, type, member) #define list_first_entry(ptr, type, member) \ list_entry((ptr)->next, type, member) #define list_next_entry(ptr, type, member) \ list_entry((ptr)->member.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_first_entry(head, type, member); \ &pos->member != (head); \ pos = list_next_entry(pos, type, member)) #define list_for_each_entry_safe(pos, n, head, member, type) \ for (pos = list_first_entry(head, type, member), \ n = list_next_entry(pos, type, member); \ &pos->member != (head); \ pos = n, n = list_next_entry(n, type, member)) /* Helper macros to iterate over a list. The structure pointed * to by "pos" must have a list_head member named "list". */ #define for_each_helper(pos, head, type) \ list_for_each_entry(pos, head, list, type) #define for_each_safe_helper(pos, n, head, type) \ list_for_each_entry_safe(pos, n, head, list, type) #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)) { list_init(list); return; } list->next = head->next; list->next->prev = list; list->prev = head->prev; list->prev->next = list; list_init(head); } static inline void list_splice_front(struct list_head *list, struct list_head *head) { list->next->prev = head; list->prev->next = head->next; head->next->prev = list->prev; head->next = list->next; } static inline void *usbi_reallocf(void *ptr, size_t size) { void *ret = realloc(ptr, size); if (!ret) free(ptr); return ret; } #if !defined(USEC_PER_SEC) #define USEC_PER_SEC 1000000L #endif #if !defined(NSEC_PER_SEC) #define NSEC_PER_SEC 1000000000L #endif #define TIMEVAL_IS_VALID(tv) \ ((tv)->tv_sec >= 0 && \ (tv)->tv_usec >= 0 && (tv)->tv_usec < USEC_PER_SEC) #define TIMESPEC_IS_SET(ts) ((ts)->tv_sec || (ts)->tv_nsec) #define TIMESPEC_CLEAR(ts) (ts)->tv_sec = (ts)->tv_nsec = 0 #define TIMESPEC_CMP(a, b, CMP) \ (((a)->tv_sec == (b)->tv_sec) \ ? ((a)->tv_nsec CMP (b)->tv_nsec) \ : ((a)->tv_sec CMP (b)->tv_sec)) #define TIMESPEC_SUB(a, b, result) \ do { \ (result)->tv_sec = (a)->tv_sec - (b)->tv_sec; \ (result)->tv_nsec = (a)->tv_nsec - (b)->tv_nsec; \ if ((result)->tv_nsec < 0L) { \ --(result)->tv_sec; \ (result)->tv_nsec += NSEC_PER_SEC; \ } \ } while (0) #if defined(PLATFORM_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) #include #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 args); #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, ...) PRINTF_FORMAT(4, 5); #define _usbi_log(ctx, level, ...) usbi_log(ctx, level, __func__, __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(ctx ,...) _usbi_log(ctx, 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(ctx, ...) do {} while (0) #endif /* ENABLE_LOGGING */ #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(itransfer) \ (TRANSFER_CTX(USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer))) #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 /* used for signalling occurrence of an internal event. */ usbi_event_t event; #ifdef HAVE_OS_TIMER /* used for timeout handling, if supported by OS. * this timer is maintained to trigger on the next pending timeout */ usbi_timer_t timer; #endif 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; /* A flag to indicate that the context is ready for hotplug notifications */ usbi_atomic_t hotplug_ready; /* 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; #if !defined(PLATFORM_WINDOWS) /* user callbacks for pollfd changes */ libusb_pollfd_added_cb fd_added_cb; libusb_pollfd_removed_cb fd_removed_cb; void *fd_cb_user_data; #endif /* 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; /* A list of currently active event sources. Protected by event_data_lock. */ struct list_head event_sources; /* A list of event sources that have been removed since the last time * event sources were waited on. Protected by event_data_lock. */ struct list_head removed_event_sources; /* A pointer and count to platform-specific data used for monitoring event * sources. Only accessed during event handling. */ void *event_data; unsigned int event_data_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; struct list_head list; }; extern struct libusb_context *usbi_default_context; extern struct list_head active_contexts_list; extern usbi_mutex_static_t active_contexts_lock; static inline struct libusb_context *usbi_get_context(struct libusb_context *ctx) { return ctx ? ctx : usbi_default_context; } enum usbi_event_flags { /* The list of event sources has been modified */ USBI_EVENT_EVENT_SOURCES_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, /* One or more hotplug messages are pending */ USBI_EVENT_HOTPLUG_MSG_PENDING = 1U << 3, /* One or more completed transfers are pending */ USBI_EVENT_TRANSFER_COMPLETED = 1U << 4, /* A device is in the process of being closed */ USBI_EVENT_DEVICE_CLOSE = 1U << 5, }; /* Macros for managing event handling state */ static inline int usbi_handling_events(struct libusb_context *ctx) { return usbi_tls_key_get(ctx->event_handling_key) != NULL; } static inline void usbi_start_event_handling(struct libusb_context *ctx) { usbi_tls_key_set(ctx->event_handling_key, ctx); } static inline void usbi_end_event_handling(struct libusb_context *ctx) { usbi_tls_key_set(ctx->event_handling_key, NULL); } struct libusb_device { usbi_atomic_t refcnt; struct libusb_context *ctx; struct libusb_device *parent_dev; uint8_t bus_number; uint8_t port_number; uint8_t device_address; enum libusb_speed speed; struct list_head list; unsigned long session_data; struct libusb_device_descriptor device_descriptor; usbi_atomic_t attached; }; 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; }; /* Function called by backend during device initialization to convert * multi-byte fields in the device descriptor to host-endian format. */ static inline void usbi_localize_device_descriptor(struct libusb_device_descriptor *desc) { desc->bcdUSB = libusb_le16_to_cpu(desc->bcdUSB); desc->idVendor = libusb_le16_to_cpu(desc->idVendor); desc->idProduct = libusb_le16_to_cpu(desc->idProduct); desc->bcdDevice = libusb_le16_to_cpu(desc->bcdDevice); } #ifdef HAVE_CLOCK_GETTIME static inline void usbi_get_monotonic_time(struct timespec *tp) { ASSERT_EQ(clock_gettime(CLOCK_MONOTONIC, tp), 0); } static inline void usbi_get_real_time(struct timespec *tp) { ASSERT_EQ(clock_gettime(CLOCK_REALTIME, tp), 0); } #else /* If the platform doesn't provide the clock_gettime() function, the backend * must provide its own clock implementations. Two clock functions are * required: * * usbi_get_monotonic_time(): returns the time since an unspecified starting * point (usually boot) that is monotonically * increasing. * usbi_get_real_time(): returns the time since system epoch. */ void usbi_get_monotonic_time(struct timespec *tp); void usbi_get_real_time(struct timespec *tp); #endif /* in-memory transfer layout: * * 1. os private data * 2. struct usbi_transfer * 3. struct libusb_transfer (which includes iso packets) [variable size] * * from a libusb_transfer, you can get the usbi_transfer by rewinding the * appropriate number of bytes. */ struct usbi_transfer { int num_iso_packets; struct list_head list; struct list_head completed_list; struct timespec timeout; int transferred; uint32_t stream_id; uint32_t state_flags; /* Protected by usbi_transfer->lock */ uint32_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; void *priv; }; 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(itransfer) \ ((struct libusb_transfer *) \ ((unsigned char *)(itransfer) \ + PTR_ALIGN(sizeof(struct usbi_transfer)))) #define LIBUSB_TRANSFER_TO_USBI_TRANSFER(transfer) \ ((struct usbi_transfer *) \ ((unsigned char *)(transfer) \ - PTR_ALIGN(sizeof(struct usbi_transfer)))) #ifdef _MSC_VER #pragma pack(push, 1) #endif /* All standard descriptors have these 2 fields in common */ struct usbi_descriptor_header { uint8_t bLength; uint8_t bDescriptorType; } LIBUSB_PACKED; struct usbi_device_descriptor { uint8_t bLength; uint8_t bDescriptorType; uint16_t bcdUSB; uint8_t bDeviceClass; uint8_t bDeviceSubClass; uint8_t bDeviceProtocol; uint8_t bMaxPacketSize0; uint16_t idVendor; uint16_t idProduct; uint16_t bcdDevice; uint8_t iManufacturer; uint8_t iProduct; uint8_t iSerialNumber; uint8_t bNumConfigurations; } LIBUSB_PACKED; struct usbi_configuration_descriptor { uint8_t bLength; uint8_t bDescriptorType; uint16_t wTotalLength; uint8_t bNumInterfaces; uint8_t bConfigurationValue; uint8_t iConfiguration; uint8_t bmAttributes; uint8_t bMaxPower; } LIBUSB_PACKED; struct usbi_interface_descriptor { uint8_t bLength; uint8_t bDescriptorType; uint8_t bInterfaceNumber; uint8_t bAlternateSetting; uint8_t bNumEndpoints; uint8_t bInterfaceClass; uint8_t bInterfaceSubClass; uint8_t bInterfaceProtocol; uint8_t iInterface; } LIBUSB_PACKED; struct usbi_string_descriptor { uint8_t bLength; uint8_t bDescriptorType; uint16_t wData[ZERO_SIZED_ARRAY]; } LIBUSB_PACKED; struct usbi_bos_descriptor { uint8_t bLength; uint8_t bDescriptorType; uint16_t wTotalLength; uint8_t bNumDeviceCaps; } LIBUSB_PACKED; #ifdef _MSC_VER #pragma pack(pop) #endif union usbi_config_desc_buf { struct usbi_configuration_descriptor desc; uint8_t buf[LIBUSB_DT_CONFIG_SIZE]; uint16_t align; /* Force 2-byte alignment */ }; union usbi_string_desc_buf { struct usbi_string_descriptor desc; uint8_t buf[255]; /* Some devices choke on size > 255 */ uint16_t align; /* Force 2-byte alignment */ }; union usbi_bos_desc_buf { struct usbi_bos_descriptor desc; uint8_t buf[LIBUSB_DT_BOS_SIZE]; uint16_t align; /* Force 2-byte alignment */ }; enum usbi_hotplug_flags { /* This callback is interested in device arrivals */ USBI_HOTPLUG_DEVICE_ARRIVED = LIBUSB_HOTPLUG_EVENT_DEVICE_ARRIVED, /* This callback is interested in device removals */ USBI_HOTPLUG_DEVICE_LEFT = LIBUSB_HOTPLUG_EVENT_DEVICE_LEFT, /* IMPORTANT: The values for the below entries must start *after* * the highest value of the above entries!!! */ /* The vendor_id field is valid for matching */ USBI_HOTPLUG_VENDOR_ID_VALID = (1U << 3), /* The product_id field is valid for matching */ USBI_HOTPLUG_PRODUCT_ID_VALID = (1U << 4), /* The dev_class field is valid for matching */ USBI_HOTPLUG_DEV_CLASS_VALID = (1U << 5), /* This callback has been unregistered and needs to be freed */ USBI_HOTPLUG_NEEDS_FREE = (1U << 6), }; struct usbi_hotplug_callback { /* Flags that control how this callback behaves */ uint8_t flags; /* Vendor ID to match (if flags says this is valid) */ uint16_t vendor_id; /* Product ID to match (if flags says this is valid) */ uint16_t product_id; /* Device class to match (if flags says this is valid) */ uint8_t dev_class; /* Callback function to invoke for matching event/device */ libusb_hotplug_callback_fn cb; /* Handle for this callback (used to match on deregister) */ libusb_hotplug_callback_handle handle; /* User data that will be passed to the callback function */ void *user_data; /* List this callback is registered in (ctx->hotplug_cbs) */ struct list_head list; }; struct usbi_hotplug_message { /* The hotplug event that occurred */ libusb_hotplug_event event; /* The device for which this hotplug event occurred */ struct libusb_device *device; /* List this message is contained in (ctx->hotplug_msgs) */ struct list_head list; }; /* shared data and functions */ void usbi_hotplug_init(struct libusb_context *ctx); void usbi_hotplug_exit(struct libusb_context *ctx); void usbi_hotplug_notification(struct libusb_context *ctx, struct libusb_device *dev, libusb_hotplug_event event); void usbi_hotplug_process(struct libusb_context *ctx, struct list_head *hotplug_msgs); 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 *itransfer); void usbi_signal_transfer_completion(struct usbi_transfer *itransfer); void usbi_connect_device(struct libusb_device *dev); void usbi_disconnect_device(struct libusb_device *dev); struct usbi_event_source { struct usbi_event_source_data { usbi_os_handle_t os_handle; short poll_events; } data; struct list_head list; }; int usbi_add_event_source(struct libusb_context *ctx, usbi_os_handle_t os_handle, short poll_events); void usbi_remove_event_source(struct libusb_context *ctx, usbi_os_handle_t os_handle); struct usbi_option { int is_set; union { int ival; } arg; }; /* OS event abstraction */ int usbi_create_event(usbi_event_t *event); void usbi_destroy_event(usbi_event_t *event); void usbi_signal_event(usbi_event_t *event); void usbi_clear_event(usbi_event_t *event); #ifdef HAVE_OS_TIMER int usbi_create_timer(usbi_timer_t *timer); void usbi_destroy_timer(usbi_timer_t *timer); int usbi_arm_timer(usbi_timer_t *timer, const struct timespec *timeout); int usbi_disarm_timer(usbi_timer_t *timer); #endif static inline int usbi_using_timer(struct libusb_context *ctx) { #ifdef HAVE_OS_TIMER return usbi_timer_valid(&ctx->timer); #else UNUSED(ctx); return 0; #endif } struct usbi_reported_events { union { struct { unsigned int event_triggered:1; #ifdef HAVE_OS_TIMER unsigned int timer_triggered:1; #endif }; unsigned int event_bits; }; void *event_data; unsigned int event_data_count; unsigned int num_ready; }; int usbi_alloc_event_data(struct libusb_context *ctx); int usbi_wait_for_events(struct libusb_context *ctx, struct usbi_reported_events *reported_events, int timeout_ms); /* accessor functions for structure private data */ static inline void *usbi_get_context_priv(struct libusb_context *ctx) { return (unsigned char *)ctx + PTR_ALIGN(sizeof(*ctx)); } static inline void *usbi_get_device_priv(struct libusb_device *dev) { return (unsigned char *)dev + PTR_ALIGN(sizeof(*dev)); } static inline void *usbi_get_device_handle_priv(struct libusb_device_handle *dev_handle) { return (unsigned char *)dev_handle + PTR_ALIGN(sizeof(*dev_handle)); } static inline void *usbi_get_transfer_priv(struct usbi_transfer *itransfer) { return itransfer->priv; } /* 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. Mutual exclusion with other init and exit calls is * guaranteed when this function is called. * * 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. * Mutual exclusion with other init and exit calls is guaranteed when * this function is called. */ 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_event_source() 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_event_source() 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_event_source() to * inform libusb of any event sources 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); /* 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). * * 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, void *buffer, size_t len); /* 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). * * 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, void *buffer, size_t len); /* 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, void **buffer); /* 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, uint8_t *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, uint8_t 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, uint8_t 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, uint8_t interface_number, uint8_t 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. Optional. * * 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 reset * 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. */ void *(*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, void *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, uint8_t 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, uint8_t 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, uint8_t 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 event sources. Optional. * * Provide this function when event sources directly indicate device * or transfer activity. If your backend does not have such event sources, * implement the handle_transfer_completion function below. * * This involves monitoring any active transfers and processing their * completion or cancellation. * * The function is passed a pointer that represents platform-specific * data for monitoring event sources (size count). This data is to be * (re)allocated as necessary when event sources are modified. * The num_ready parameter indicates the number of event sources that * have reported events. 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, void *event_data, unsigned int count, unsigned int num_ready); /* Handle transfer completion. Optional. * * Provide this function when there are no event sources available that * directly indicate device or transfer activity. If your backend does * have such event sources, 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); /* Number of bytes to reserve for per-context private backend data. * This private data area is accessible by calling * usbi_get_context_priv() on the libusb_context instance. */ size_t context_priv_size; /* Number of bytes to reserve for per-device private backend data. * This private data area is accessible by calling * usbi_get_device_priv() on the libusb_device instance. */ size_t device_priv_size; /* Number of bytes to reserve for per-handle private backend data. * This private data area is accessible by calling * usbi_get_device_handle_priv() on the libusb_device_handle instance. */ 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_get_transfer_priv() on the usbi_transfer instance. */ size_t transfer_priv_size; }; extern const struct usbi_os_backend usbi_backend; #define for_each_context(c) \ for_each_helper(c, &active_contexts_list, struct libusb_context) #define for_each_device(ctx, d) \ for_each_helper(d, &(ctx)->usb_devs, struct libusb_device) #define for_each_device_safe(ctx, d, n) \ for_each_safe_helper(d, n, &(ctx)->usb_devs, struct libusb_device) #define for_each_open_device(ctx, h) \ for_each_helper(h, &(ctx)->open_devs, struct libusb_device_handle) #define __for_each_transfer(list, t) \ for_each_helper(t, (list), struct usbi_transfer) #define for_each_transfer(ctx, t) \ __for_each_transfer(&(ctx)->flying_transfers, t) #define __for_each_transfer_safe(list, t, n) \ for_each_safe_helper(t, n, (list), struct usbi_transfer) #define for_each_transfer_safe(ctx, t, n) \ __for_each_transfer_safe(&(ctx)->flying_transfers, t, n) #define __for_each_completed_transfer_safe(list, t, n) \ list_for_each_entry_safe(t, n, (list), completed_list, struct usbi_transfer) #define for_each_event_source(ctx, e) \ for_each_helper(e, &(ctx)->event_sources, struct usbi_event_source) #define for_each_removed_event_source(ctx, e) \ for_each_helper(e, &(ctx)->removed_event_sources, struct usbi_event_source) #define for_each_removed_event_source_safe(ctx, e, n) \ for_each_safe_helper(e, n, &(ctx)->removed_event_sources, struct usbi_event_source) #define for_each_hotplug_cb(ctx, c) \ for_each_helper(c, &(ctx)->hotplug_cbs, struct usbi_hotplug_callback) #define for_each_hotplug_cb_safe(ctx, c, n) \ for_each_safe_helper(c, n, &(ctx)->hotplug_cbs, struct usbi_hotplug_callback) #ifdef __cplusplus } #endif #endif