From 809a6df614b87be780df9b0c97ba6c0bb6172aab Mon Sep 17 00:00:00 2001 From: Ryan Metcalfe Date: Mon, 26 Jul 2021 16:07:48 -0400 Subject: descriptor: Introduce interface association descriptors (IAD) Types: struct libusb_interface_association_descriptor struct libusb_interface_association_descriptor_array Accessor / cleanup functions: libusb_get_interface_association_descriptors libusb_get_active_interface_association_descriptors libusb_free_interface_association_descriptors Signed-off-by: Ryan Metcalfe [Tormod: Fixed Doxygen comment] Signed-off-by: Tormod Volden --- libusb/descriptor.c | 185 ++++++++++++++++++++++++++++++++++++++++++++++++++ libusb/libusb-1.0.def | 6 ++ libusb/libusb.h | 70 +++++++++++++++++++ libusb/version_nano.h | 2 +- 4 files changed, 262 insertions(+), 1 deletion(-) diff --git a/libusb/descriptor.c b/libusb/descriptor.c index 5cdacbb..727cf98 100644 --- a/libusb/descriptor.c +++ b/libusb/descriptor.c @@ -1137,3 +1137,188 @@ int API_EXPORTED libusb_get_string_descriptor_ascii(libusb_device_handle *dev_ha data[di] = 0; return di; } + +static int parse_iad_array(struct libusb_context *ctx, + struct libusb_interface_association_descriptor_array *iad_array, + const uint8_t *buffer, int size) +{ + uint8_t i; + struct usbi_descriptor_header header; + int consumed = 0; + const uint8_t *buf = buffer; + struct libusb_interface_association_descriptor *iad; + + if (size < LIBUSB_DT_CONFIG_SIZE) { + usbi_err(ctx, "short config descriptor read %d/%d", + size, LIBUSB_DT_CONFIG_SIZE); + return LIBUSB_ERROR_IO; + } + + // First pass: Iterate through desc list, count number of IADs + iad_array->length = 0; + while (consumed < size) { + parse_descriptor(buf, "bb", &header); + if (header.bDescriptorType == LIBUSB_DT_INTERFACE_ASSOCIATION) + iad_array->length++; + buf += header.bLength; + consumed += header.bLength; + } + + iad_array->iad = NULL; + if (iad_array->length > 0) { + iad = calloc(iad_array->length, sizeof(*iad)); + if (!iad) + return LIBUSB_ERROR_NO_MEM; + + iad_array->iad = iad; + + // Second pass: Iterate through desc list, fill IAD structures + consumed = 0; + i = 0; + while (consumed < size) { + parse_descriptor(buffer, "bb", &header); + if (header.bDescriptorType == LIBUSB_DT_INTERFACE_ASSOCIATION) + parse_descriptor(buffer, "bbbbbbbb", &iad[i++]); + buffer += header.bLength; + consumed += header.bLength; + } + } + + return LIBUSB_SUCCESS; +} + +static int raw_desc_to_iad_array(struct libusb_context *ctx, const uint8_t *buf, + int size, struct libusb_interface_association_descriptor_array **iad_array) +{ + struct libusb_interface_association_descriptor_array *_iad_array + = calloc(1, sizeof(*_iad_array)); + int r; + + if (!_iad_array) + return LIBUSB_ERROR_NO_MEM; + + r = parse_iad_array(ctx, _iad_array, buf, size); + if (r < 0) { + usbi_err(ctx, "parse_iad_array failed with error %d", r); + free(_iad_array); + return r; + } + + *iad_array = _iad_array; + return LIBUSB_SUCCESS; +} + +/** \ingroup libusb_desc + * Get an array of interface association descriptors (IAD) for a given + * configuration. + * This is a non-blocking function which does not involve any requests being + * sent to the device. + * + * \param dev a device + * \param config_index the index of the configuration you wish to retrieve the + * IADs for. + * \param iad_array output location for the array of IADs. Only valid if 0 was + * returned. Must be freed with libusb_free_interface_association_descriptors() + * after use. It's possible that a given configuration contains no IADs. In this + * case the iad_array is still output, but will have 'length' field set to 0, and + * iad field set to NULL. + * \returns 0 on success + * \returns LIBUSB_ERROR_NOT_FOUND if the configuration does not exist + * \returns another LIBUSB_ERROR code on error + * \see libusb_get_active_interface_association_descriptors() + */ +int API_EXPORTED libusb_get_interface_association_descriptors(libusb_device *dev, + uint8_t config_index, struct libusb_interface_association_descriptor_array **iad_array) +{ + union usbi_config_desc_buf _config; + uint16_t config_len; + uint8_t *buf; + int r; + + if (!iad_array) + return LIBUSB_ERROR_INVALID_PARAM; + + usbi_dbg(DEVICE_CTX(dev), "IADs for config index %u", config_index); + if (config_index >= dev->device_descriptor.bNumConfigurations) + return LIBUSB_ERROR_NOT_FOUND; + + r = get_config_descriptor(dev, config_index, _config.buf, sizeof(_config.buf)); + if (r < 0) + return r; + + config_len = libusb_le16_to_cpu(_config.desc.wTotalLength); + buf = malloc(config_len); + if (!buf) + return LIBUSB_ERROR_NO_MEM; + + r = get_config_descriptor(dev, config_index, buf, config_len); + if (r >= 0) + r = raw_desc_to_iad_array(DEVICE_CTX(dev), buf, r, iad_array); + + free(buf); + return r; +} + +/** \ingroup libusb_desc + * Get an array of interface association descriptors (IAD) for the currently + * active configuration. + * This is a non-blocking function which does not involve any requests being + * sent to the device. + * + * \param dev a device + * \param iad_array output location for the array of IADs. Only valid if 0 was + * returned. Must be freed with libusb_free_interface_association_descriptors() + * after use. It's possible that a given configuration contains no IADs. In this + * case the iad_array is still output, but will have 'length' field set to 0, and + * iad field set to NULL. + * \returns 0 on success + * \returns LIBUSB_ERROR_NOT_FOUND if the device is in unconfigured state + * \returns another LIBUSB_ERROR code on error + * \see libusb_get_interface_association_descriptors + */ +int API_EXPORTED libusb_get_active_interface_association_descriptors(libusb_device *dev, + struct libusb_interface_association_descriptor_array **iad_array) +{ + union usbi_config_desc_buf _config; + uint16_t config_len; + uint8_t *buf; + int r; + + if (!iad_array) + return LIBUSB_ERROR_INVALID_PARAM; + + r = get_active_config_descriptor(dev, _config.buf, sizeof(_config.buf)); + if (r < 0) + return r; + + config_len = libusb_le16_to_cpu(_config.desc.wTotalLength); + buf = malloc(config_len); + if (!buf) + return LIBUSB_ERROR_NO_MEM; + + r = get_active_config_descriptor(dev, buf, config_len); + if (r >= 0) + r = raw_desc_to_iad_array(DEVICE_CTX(dev), buf, r, iad_array); + free(buf); + return r; +} + +/** \ingroup libusb_desc + * Free an array of interface association descriptors (IADs) obtained from + * libusb_get_interface_association_descriptors() or + * libusb_get_active_interface_association_descriptors(). + * It is safe to call this function with a NULL iad_array parameter, in which + * case the function simply returns. + * + * \param iad_array the IAD array to free + */ +void API_EXPORTED libusb_free_interface_association_descriptors( + struct libusb_interface_association_descriptor_array *iad_array) +{ + if (!iad_array) + return; + + if (iad_array->iad) + free((void*)iad_array->iad); + free(iad_array); +} diff --git a/libusb/libusb-1.0.def b/libusb/libusb-1.0.def index c8d1eb2..01276aa 100644 --- a/libusb/libusb-1.0.def +++ b/libusb/libusb-1.0.def @@ -40,6 +40,8 @@ EXPORTS libusb_free_container_id_descriptor@4 = libusb_free_container_id_descriptor libusb_free_device_list libusb_free_device_list@8 = libusb_free_device_list + libusb_free_interface_association_descriptors + libusb_free_interface_association_descriptors@4 = libusb_free_interface_association_descriptors libusb_free_pollfds libusb_free_pollfds@4 = libusb_free_pollfds libusb_free_ss_endpoint_companion_descriptor @@ -54,6 +56,8 @@ EXPORTS libusb_free_usb_2_0_extension_descriptor@4 = libusb_free_usb_2_0_extension_descriptor libusb_get_active_config_descriptor libusb_get_active_config_descriptor@8 = libusb_get_active_config_descriptor + libusb_get_active_interface_association_descriptors + libusb_get_active_interface_association_descriptors@8 = libusb_get_active_interface_association_descriptors libusb_get_bos_descriptor libusb_get_bos_descriptor@8 = libusb_get_bos_descriptor libusb_get_bus_number @@ -76,6 +80,8 @@ EXPORTS libusb_get_device_list@8 = libusb_get_device_list libusb_get_device_speed libusb_get_device_speed@4 = libusb_get_device_speed + libusb_get_interface_association_descriptors + libusb_get_interface_association_descriptors@12 = libusb_get_interface_association_descriptors libusb_get_max_iso_packet_size libusb_get_max_iso_packet_size@8 = libusb_get_max_iso_packet_size libusb_get_max_packet_size diff --git a/libusb/libusb.h b/libusb/libusb.h index bc7ef16..0946a55 100644 --- a/libusb/libusb.h +++ b/libusb/libusb.h @@ -269,6 +269,10 @@ enum libusb_descriptor_type { /** Endpoint descriptor. See libusb_endpoint_descriptor. */ LIBUSB_DT_ENDPOINT = 0x05, + /** Interface Association Descriptor. + * See libusb_interface_association_descriptor */ + LIBUSB_DT_INTERFACE_ASSOCIATION = 0x0b, + /** BOS descriptor */ LIBUSB_DT_BOS = 0x0f, @@ -632,6 +636,65 @@ struct libusb_endpoint_descriptor { int extra_length; }; +/** \ingroup libusb_desc + * A structure representing the standard USB interface association descriptor. + * This descriptor is documented in section 9.6.4 of the USB 3.0 specification. + * All multiple-byte fields are represented in host-endian format. + */ +struct libusb_interface_association_descriptor { + /** Size of this descriptor (in bytes) */ + uint8_t bLength; + + /** Descriptor type. Will have value + * \ref libusb_descriptor_type::LIBUSB_DT_INTERFACE_ASSOCIATION + * LIBUSB_DT_INTERFACE_ASSOCIATION in this context. */ + uint8_t bDescriptorType; + + /** Interface number of the first interface that is associated + * with this function */ + uint8_t bFirstInterface; + + /** Number of contiguous interfaces that are associated with + * this function */ + uint8_t bInterfaceCount; + + /** USB-IF class code for this function. + * A value of zero is not allowed in this descriptor. + * If this field is 0xff, the function class is vendor-specific. + * All other values are reserved for assignment by the USB-IF. + */ + uint8_t bFunctionClass; + + /** USB-IF subclass code for this function. + * If this field is not set to 0xff, all values are reserved + * for assignment by the USB-IF + */ + uint8_t bFunctionSubClass; + + /** USB-IF protocol code for this function. + * These codes are qualified by the values of the bFunctionClass + * and bFunctionSubClass fields. + */ + uint8_t bFunctionProtocol; + + /** Index of string descriptor describing this function */ + uint8_t iFunction; +}; + +/** \ingroup libusb_desc + * Structure containing an array of 0 or more interface association + * descriptors + */ +struct libusb_interface_association_descriptor_array { + /** Array of interface association descriptors. The size of this array + * is determined by the length field. + */ + const struct libusb_interface_association_descriptor *iad; + + /** Number of interface association descriptors contained. Read-only. */ + int length; +}; + /** \ingroup libusb_desc * A structure representing the standard USB interface descriptor. This * descriptor is documented in section 9.6.5 of the USB 3.0 specification. @@ -1433,6 +1496,13 @@ int LIBUSB_CALL libusb_get_max_packet_size(libusb_device *dev, int LIBUSB_CALL libusb_get_max_iso_packet_size(libusb_device *dev, unsigned char endpoint); +int LIBUSB_CALL libusb_get_interface_association_descriptors(libusb_device *dev, + uint8_t config_index, struct libusb_interface_association_descriptor_array **iad_array); +int LIBUSB_CALL libusb_get_active_interface_association_descriptors(libusb_device *dev, + struct libusb_interface_association_descriptor_array **iad_array); +void LIBUSB_CALL libusb_free_interface_association_descriptors( + struct libusb_interface_association_descriptor_array *iad_array); + int LIBUSB_CALL libusb_wrap_sys_device(libusb_context *ctx, intptr_t sys_dev, libusb_device_handle **dev_handle); int LIBUSB_CALL libusb_open(libusb_device *dev, libusb_device_handle **dev_handle); void LIBUSB_CALL libusb_close(libusb_device_handle *dev_handle); diff --git a/libusb/version_nano.h b/libusb/version_nano.h index 8454b80..04b0954 100644 --- a/libusb/version_nano.h +++ b/libusb/version_nano.h @@ -1 +1 @@ -#define LIBUSB_NANO 11763 +#define LIBUSB_NANO 11764 -- cgit v1.2.1