/* -*- Mode: C; indent-tabs-mode:t ; c-basic-offset:8 -*- */
/*
* USB descriptor handling functions for libusbx
* Copyright © 2007 Daniel Drake <[email protected]>
* Copyright © 2001 Johannes Erdfelt <[email protected]>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <errno.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include "libusbi.h"
#define DESC_HEADER_LENGTH 2
#define DEVICE_DESC_LENGTH 18
#define CONFIG_DESC_LENGTH 9
#define INTERFACE_DESC_LENGTH 9
#define ENDPOINT_DESC_LENGTH 7
#define ENDPOINT_AUDIO_DESC_LENGTH 9
/** @defgroup desc USB descriptors
* This page details how to examine the various standard USB descriptors
* for detected devices
*/
/* set host_endian if the w values are already in host endian format,
* as opposed to bus endian. */
int usbi_parse_descriptor(const unsigned char *source, const char *descriptor,
void *dest, int host_endian)
{
const unsigned char *sp = source;
unsigned char *dp = dest;
uint16_t w;
const char *cp;
uint32_t d;
for (cp = descriptor; *cp; cp++) {
switch (*cp) {
case 'b': /* 8-bit byte */
*dp++ = *sp++;
break;
case 'w': /* 16-bit word, convert from little endian to CPU */
dp += ((uintptr_t)dp & 1); /* Align to word boundary */
if (host_endian) {
memcpy(dp, sp, 2);
} else {
w = (sp[1] << 8) | sp[0];
*((uint16_t *)dp) = w;
}
sp += 2;
dp += 2;
break;
case 'd': /* 32-bit word, convert from little endian to CPU */
dp += ((uintptr_t)dp & 1); /* Align to word boundary */
if (host_endian) {
memcpy(dp, sp, 4);
} else {
d = (sp[3] << 24) | (sp[2] << 16) |
(sp[1] << 8) | sp[0];
*((uint32_t *)dp) = d;
}
sp += 4;
dp += 4;
break;
case 'u': /* 16 byte UUID */
memcpy(dp, sp, 16);
sp += 16;
dp += 16;
break;
}
}
return (int) (sp - source);
}
static void clear_endpoint(struct libusb_endpoint_descriptor *endpoint)
{
if (endpoint->extra)
free((unsigned char *) endpoint->extra);
}
static int parse_endpoint(struct libusb_context *ctx,
struct libusb_endpoint_descriptor *endpoint, unsigned char *buffer,
int size, int host_endian)
{
struct usb_descriptor_header header;
unsigned char *extra;
unsigned char *begin;
int parsed = 0;
int len;
if (size < DESC_HEADER_LENGTH) {
usbi_err(ctx, "short endpoint descriptor read %d/%d",
size, DESC_HEADER_LENGTH);
return LIBUSB_ERROR_IO;
}
usbi_parse_descriptor(buffer, "bb", &header, 0);
if (header.bDescriptorType != LIBUSB_DT_ENDPOINT) {
usbi_err(ctx, "unexpected descriptor %x (expected %x)",
header.bDescriptorType, LIBUSB_DT_ENDPOINT);
return parsed;
}
if (header.bLength > size) {
usbi_warn(ctx, "short endpoint descriptor read %d/%d",
size, header.bLength);
return parsed;
}
if (header.bLength >= ENDPOINT_AUDIO_DESC_LENGTH)
usbi_parse_descriptor(buffer, "bbbbwbbb", endpoint, host_endian);
else if (header.bLength >= ENDPOINT_DESC_LENGTH)
usbi_parse_descriptor(buffer, "bbbbwb", endpoint, host_endian);
else {
usbi_err(ctx, "invalid endpoint bLength (%d)", header.bLength);
return LIBUSB_ERROR_IO;
}
buffer += header.bLength;
size -= header.bLength;
parsed += header.bLength;
/* Skip over the rest of the Class Specific or Vendor Specific */
/* descriptors */
begin = buffer;
while (size >= DESC_HEADER_LENGTH) {
usbi_parse_descriptor(buffer, "bb", &header, 0);
if (header.bLength < DESC_HEADER_LENGTH) {
usbi_err(ctx, "invalid extra ep desc len (%d)",
header.bLength);
return LIBUSB_ERROR_IO;
} else if (header.bLength > size) {
usbi_warn(ctx, "short extra ep desc read %d/%d",
size, header.bLength);
return parsed;
}
/* If we find another "proper" descriptor then we're done */
if ((header.bDescriptorType == LIBUSB_DT_ENDPOINT) ||
(header.bDescriptorType == LIBUSB_DT_INTERFACE) ||
(header.bDescriptorType == LIBUSB_DT_CONFIG) ||
(header.bDescriptorType == LIBUSB_DT_DEVICE))
break;
usbi_dbg("skipping descriptor %x", header.bDescriptorType);
buffer += header.bLength;
size -= header.bLength;
parsed += header.bLength;
}
/* Copy any unknown descriptors into a storage area for drivers */
/* to later parse */
len = (int)(buffer - begin);
if (!len) {
endpoint->extra = NULL;
endpoint->extra_length = 0;
return parsed;
}
extra = malloc(len);
endpoint->extra = extra;
if (!extra) {
endpoint->extra_length = 0;
return LIBUSB_ERROR_NO_MEM;
}
memcpy(extra, begin, len);
endpoint->extra_length = len;
return parsed;
}
static void clear_interface(struct libusb_interface *usb_interface)
{
int i;
int j;
if (usb_interface->altsetting) {
for (i = 0; i < usb_interface->num_altsetting; i++) {
struct libusb_interface_descriptor *ifp =
(struct libusb_interface_descriptor *)
usb_interface->altsetting + i;
if (ifp->extra)
free((void *) ifp->extra);
if (ifp->endpoint) {
for (j = 0; j < ifp->bNumEndpoints; j++)
clear_endpoint((struct libusb_endpoint_descriptor *)
ifp->endpoint + j);
free((void *) ifp->endpoint);
}
}
free((void *) usb_interface->altsetting);
usb_interface->altsetting = NULL;
}
}
static int parse_interface(libusb_context *ctx,
struct libusb_interface *usb_interface, unsigned char *buffer, int size,
int host_endian)
{
int i;
int len;
int r;
int parsed = 0;
int interface_number = -1;
size_t tmp;
struct usb_descriptor_header header;
struct libusb_interface_descriptor *ifp;
unsigned char *begin;
usb_interface->num_altsetting = 0;
while (size >= INTERFACE_DESC_LENGTH) {
struct libusb_interface_descriptor *altsetting =
(struct libusb_interface_descriptor *) usb_interface->altsetting;
altsetting = usbi_reallocf(altsetting,
sizeof(struct libusb_interface_descriptor) *
(usb_interface->num_altsetting + 1));
if (!altsetting) {
r = LIBUSB_ERROR_NO_MEM;
goto err;
}
usb_interface->altsetting = altsetting;
ifp = altsetting + usb_interface->num_altsetting;
usbi_parse_descriptor(buffer, "bbbbbbbbb", ifp, 0);
if (ifp->bDescriptorType != LIBUSB_DT_INTERFACE) {
usbi_err(ctx, "unexpected descriptor %x (expected %x)",
ifp->bDescriptorType, LIBUSB_DT_INTERFACE);
return parsed;
}
if (ifp->bLength < INTERFACE_DESC_LENGTH) {
usbi_err(ctx, "invalid interface bLength (%d)",
ifp->bLength);
r = LIBUSB_ERROR_IO;
goto err;
}
if (ifp->bLength > size) {
usbi_warn(ctx, "short intf descriptor read %d/%d",
size, ifp->bLength);
return parsed;
}
if (ifp->bNumEndpoints > USB_MAXENDPOINTS) {
usbi_err(ctx, "too many endpoints (%d)", ifp->bNumEndpoints);
r = LIBUSB_ERROR_IO;
goto err;
}
usb_interface->num_altsetting++;
ifp->extra = NULL;
ifp->extra_length = 0;
ifp->endpoint = NULL;
if (interface_number == -1)
interface_number = ifp->bInterfaceNumber;
/* Skip over the interface */
buffer += ifp->bLength;
parsed += ifp->bLength;
size -= ifp->bLength;
begin = buffer;
/* Skip over any interface, class or vendor descriptors */
while (size >= DESC_HEADER_LENGTH) {
usbi_parse_descriptor(buffer, "bb", &header, 0);
if (header.bLength < DESC_HEADER_LENGTH) {
usbi_err(ctx,
"invalid extra intf desc len (%d)",
header.bLength);
r = LIBUSB_ERROR_IO;
goto err;
} else if (header.bLength > size) {
usbi_warn(ctx,
"short extra intf desc read %d/%d",
size, header.bLength);
return parsed;
}
/* If we find another "proper" descriptor then we're done */
if ((header.bDescriptorType == LIBUSB_DT_INTERFACE) ||
(header.bDescriptorType == LIBUSB_DT_ENDPOINT) ||
(header.bDescriptorType == LIBUSB_DT_CONFIG) ||
(header.bDescriptorType == LIBUSB_DT_DEVICE))
break;
buffer += header.bLength;
parsed += header.bLength;
size -= header.bLength;
}
/* Copy any unknown descriptors into a storage area for */
/* drivers to later parse */
len = (int)(buffer - begin);
if (len) {
ifp->extra = malloc(len);
if (!ifp->extra) {
r = LIBUSB_ERROR_NO_MEM;
goto err;
}
memcpy((unsigned char *) ifp->extra, begin, len);
ifp->extra_length = len;
}
if (ifp->bNumEndpoints > 0) {
struct libusb_endpoint_descriptor *endpoint;
tmp = ifp->bNumEndpoints * sizeof(struct libusb_endpoint_descriptor);
endpoint = malloc(tmp);
ifp->endpoint = endpoint;
if (!endpoint) {
r = LIBUSB_ERROR_NO_MEM;
goto err;
}
memset(endpoint, 0, tmp);
for (i = 0; i < ifp->bNumEndpoints; i++) {
r = parse_endpoint(ctx, endpoint + i, buffer, size,
host_endian);
if (r < 0)
goto err;
if (r == 0) {
ifp->bNumEndpoints = (uint8_t)i;
break;;
}
buffer += r;
parsed += r;
size -= r;
}
}
/* We check to see if it's an alternate to this one */
ifp = (struct libusb_interface_descriptor *) buffer;
if (size < LIBUSB_DT_INTERFACE_SIZE ||
ifp->bDescriptorType != LIBUSB_DT_INTERFACE ||
ifp->bInterfaceNumber != interface_number)
return parsed;
}
return parsed;
err:
clear_interface(usb_interface);
return r;
}
static void clear_configuration(struct libusb_config_descriptor *config)
{
if (config->interface) {
int i;
for (i = 0; i < config->bNumInterfaces; i++)
clear_interface((struct libusb_interface *)
config->interface + i);
free((void *) config->interface);
}
if (config->extra)
free((void *) config->extra);
}
static int parse_configuration(struct libusb_context *ctx,
struct libusb_config_descriptor *config, unsigned char *buffer,
int size, int host_endian)
{
int i;
int r;
size_t tmp;
struct usb_descriptor_header header;
struct libusb_interface *usb_interface;
if (size < LIBUSB_DT_CONFIG_SIZE) {
usbi_err(ctx, "short config descriptor read %d/%d",
size, LIBUSB_DT_CONFIG_SIZE);
return LIBUSB_ERROR_IO;
}
usbi_parse_descriptor(buffer, "bbwbbbbb", config, host_endian);
if (config->bDescriptorType != LIBUSB_DT_CONFIG) {
usbi_err(ctx, "unexpected descriptor %x (expected %x)",
config->bDescriptorType, LIBUSB_DT_CONFIG);
return LIBUSB_ERROR_IO;
}
if (config->bLength < LIBUSB_DT_CONFIG_SIZE) {
usbi_err(ctx, "invalid config bLength (%d)", config->bLength);
return LIBUSB_ERROR_IO;
}
if (config->bLength > size) {
usbi_err(ctx, "short config descriptor read %d/%d",
size, config->bLength);
return LIBUSB_ERROR_IO;
}
if (config->bNumInterfaces > USB_MAXINTERFACES) {
usbi_err(ctx, "too many interfaces (%d)", config->bNumInterfaces);
return LIBUSB_ERROR_IO;
}
tmp = config->bNumInterfaces * sizeof(struct libusb_interface);
usb_interface = malloc(tmp);
config->interface = usb_interface;
if (!config->interface)
return LIBUSB_ERROR_NO_MEM;
memset(usb_interface, 0, tmp);
buffer += config->bLength;
size -= config->bLength;
config->extra = NULL;
config->extra_length = 0;
for (i = 0; i < config->bNumInterfaces; i++) {
int len;
unsigned char *begin;
/* Skip over the rest of the Class Specific or Vendor */
/* Specific descriptors */
begin = buffer;
while (size >= DESC_HEADER_LENGTH) {
usbi_parse_descriptor(buffer, "bb", &header, 0);
if (header.bLength < DESC_HEADER_LENGTH) {
usbi_err(ctx,
"invalid extra config desc len (%d)",
header.bLength);
r = LIBUSB_ERROR_IO;
goto err;
} else if (header.bLength > size) {
usbi_warn(ctx,
"short extra config desc read %d/%d",
size, header.bLength);
config->bNumInterfaces = (uint8_t)i;
return size;
}
/* If we find another "proper" descriptor then we're done */
if ((header.bDescriptorType == LIBUSB_DT_ENDPOINT) ||
(header.bDescriptorType == LIBUSB_DT_INTERFACE) ||
(header.bDescriptorType == LIBUSB_DT_CONFIG) ||
(header.bDescriptorType == LIBUSB_DT_DEVICE))
break;
usbi_dbg("skipping descriptor 0x%x\n", header.bDescriptorType);
buffer += header.bLength;
size -= header.bLength;
}
/* Copy any unknown descriptors into a storage area for */
/* drivers to later parse */
len = (int)(buffer - begin);
if (len) {
/* FIXME: We should realloc and append here */
if (!config->extra_length) {
config->extra = malloc(len);
if (!config->extra) {
r = LIBUSB_ERROR_NO_MEM;
goto err;
}
memcpy((unsigned char *) config->extra, begin, len);
config->extra_length = len;
}
}
r = parse_interface(ctx, usb_interface + i, buffer, size, host_endian);
if (r < 0)
goto err;
if (r == 0) {
config->bNumInterfaces = (uint8_t)i;
break;
}
buffer += r;
size -= r;
}
return size;
err:
clear_configuration(config);
return r;
}
static int raw_desc_to_config(struct libusb_context *ctx,
unsigned char *buf, int size, int host_endian,
struct libusb_config_descriptor **config)
{
struct libusb_config_descriptor *_config = malloc(sizeof(*_config));
int r;
if (!_config)
return LIBUSB_ERROR_NO_MEM;
r = parse_configuration(ctx, _config, buf, size, host_endian);
if (r < 0) {
usbi_err(ctx, "parse_configuration failed with error %d", r);
free(_config);
return r;
} else if (r > 0) {
usbi_warn(ctx, "still %d bytes of descriptor data left", r);
}
*config = _config;
return LIBUSB_SUCCESS;
}
int usbi_device_cache_descriptor(libusb_device *dev)
{
int r, host_endian = 0;
r = usbi_backend->get_device_descriptor(dev, (unsigned char *) &dev->device_descriptor,
&host_endian);
if (r < 0)
return r;
if (!host_endian) {
dev->device_descriptor.bcdUSB = libusb_le16_to_cpu(dev->device_descriptor.bcdUSB);
dev->device_descriptor.idVendor = libusb_le16_to_cpu(dev->device_descriptor.idVendor);
dev->device_descriptor.idProduct = libusb_le16_to_cpu(dev->device_descriptor.idProduct);
dev->device_descriptor.bcdDevice = libusb_le16_to_cpu(dev->device_descriptor.bcdDevice);
}
return LIBUSB_SUCCESS;
}
/** \ingroup desc
* Get the USB device descriptor for a given device.
*
* This is a non-blocking function; the device descriptor is cached in memory.
*
* Note since libusbx-1.0.16, \ref LIBUSBX_API_VERSION >= 0x01000102, this
* function always succeeds.
*
* \param dev the device
* \param desc output location for the descriptor data
* \returns 0 on success or a LIBUSB_ERROR code on failure
*/
int API_EXPORTED libusb_get_device_descriptor(libusb_device *dev,
struct libusb_device_descriptor *desc)
{
usbi_dbg("");
memcpy((unsigned char *) desc, (unsigned char *) &dev->device_descriptor,
sizeof (dev->device_descriptor));
return 0;
}
/** \ingroup desc
* Get the configuration value 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 config output location for the configuration value. Only
* valid if 0 was returned.
* \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_active_config_descriptor
*/
int API_EXPORTED libusb_get_active_config_value(libusb_device *dev,
uint8_t *config)
{
struct libusb_config_descriptor _config;
unsigned char tmp[LIBUSB_DT_CONFIG_SIZE];
int host_endian = 0;
int r;
r = usbi_backend->get_active_config_descriptor(dev, tmp,
LIBUSB_DT_CONFIG_SIZE, &host_endian);
if (r < 0)
return r;
if (r < LIBUSB_DT_CONFIG_SIZE) {
usbi_err(dev->ctx, "short config descriptor read %d/%d",
r, LIBUSB_DT_CONFIG_SIZE);
return LIBUSB_ERROR_IO;
}
usbi_parse_descriptor(tmp, "bbwbb", &_config, host_endian);
*config = _config.bConfigurationValue;
return 0;
}
/** \ingroup desc
* Get the USB configuration descriptor 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 config output location for the USB configuration descriptor. Only
* valid if 0 was returned. Must be freed with libusb_free_config_descriptor()
* after use.
* \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_config_descriptor
*/
int API_EXPORTED libusb_get_active_config_descriptor(libusb_device *dev,
struct libusb_config_descriptor **config)
{
struct libusb_config_descriptor _config;
unsigned char tmp[LIBUSB_DT_CONFIG_SIZE];
unsigned char *buf = NULL;
int host_endian = 0;
int r;
r = usbi_backend->get_active_config_descriptor(dev, tmp,
LIBUSB_DT_CONFIG_SIZE, &host_endian);
if (r < 0)
return r;
if (r < LIBUSB_DT_CONFIG_SIZE) {
usbi_err(dev->ctx, "short config descriptor read %d/%d",
r, LIBUSB_DT_CONFIG_SIZE);
return LIBUSB_ERROR_IO;
}
usbi_parse_descriptor(tmp, "bbw", &_config, host_endian);
buf = malloc(_config.wTotalLength);
if (!buf)
return LIBUSB_ERROR_NO_MEM;
r = usbi_backend->get_active_config_descriptor(dev, buf,
_config.wTotalLength, &host_endian);
if (r >= 0)
r = raw_desc_to_config(dev->ctx, buf, r, host_endian, config);
free(buf);
return r;
}
/** \ingroup desc
* Get a USB configuration descriptor based on its index.
* 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
* \param config output location for the USB configuration descriptor. Only
* valid if 0 was returned. Must be freed with libusb_free_config_descriptor()
* after use.
* \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_config_descriptor()
* \see libusb_get_config_descriptor_by_value()
*/
int API_EXPORTED libusb_get_config_descriptor(libusb_device *dev,
uint8_t config_index, struct libusb_config_descriptor **config)
{
struct libusb_config_descriptor _config;
unsigned char tmp[LIBUSB_DT_CONFIG_SIZE];
unsigned char *buf = NULL;
int host_endian = 0;
int r;
usbi_dbg("index %d", config_index);
if (config_index >= dev->num_configurations)
return LIBUSB_ERROR_NOT_FOUND;
r = usbi_backend->get_config_descriptor(dev, config_index, tmp,
LIBUSB_DT_CONFIG_SIZE, &host_endian);
if (r < 0)
return r;
if (r < LIBUSB_DT_CONFIG_SIZE) {
usbi_err(dev->ctx, "short config descriptor read %d/%d",
r, LIBUSB_DT_CONFIG_SIZE);
return LIBUSB_ERROR_IO;
}
usbi_parse_descriptor(tmp, "bbw", &_config, host_endian);
buf = malloc(_config.wTotalLength);
if (!buf)
return LIBUSB_ERROR_NO_MEM;
r = usbi_backend->get_config_descriptor(dev, config_index, buf,
_config.wTotalLength, &host_endian);
if (r >= 0)
r = raw_desc_to_config(dev->ctx, buf, r, host_endian, config);
free(buf);
return r;
}
/** \ingroup desc
* Get the raw bytes of a USB configuration descriptor based on its index.
* 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
* \param buffer output location for the buffer pointer. Only valid if 0 was
* returned. Must be freed by the caller.
* \param len output location for the buffer length.
* after use.
* \returns the buffer length on success
* \returns LIBUSB_ERROR_NOT_FOUND if the configuration does not exist
* \returns another LIBUSB_ERROR code on error
* \see libusb_get_config_descriptor()
*/
int API_EXPORTED libusb_get_raw_config_descriptor(libusb_device *dev,
uint8_t config_index, unsigned char **buffer)
{
struct libusb_config_descriptor _config;
unsigned char tmp[LIBUSB_DT_CONFIG_SIZE];
unsigned char *buf = NULL;
int host_endian = 0;
int r;
usbi_dbg("index %d", config_index);
if (config_index >= dev->num_configurations)
return LIBUSB_ERROR_NOT_FOUND;
r = usbi_backend->get_config_descriptor(dev, config_index, tmp,
LIBUSB_DT_CONFIG_SIZE, &host_endian);
if (r < 0)
return r;
if (r < LIBUSB_DT_CONFIG_SIZE) {
usbi_err(dev->ctx, "short config descriptor read %d/%d",
r, LIBUSB_DT_CONFIG_SIZE);
return LIBUSB_ERROR_IO;
}
usbi_parse_descriptor(tmp, "bbw", &_config, host_endian);
buf = malloc(_config.wTotalLength);
if (!buf)
return LIBUSB_ERROR_NO_MEM;
r = usbi_backend->get_config_descriptor(dev, config_index, buf,
_config.wTotalLength, &host_endian);
if (r >= 0)
*buffer = buf;
else
free(buf);
return r;
}
/* iterate through all configurations, returning the index of the configuration
* matching a specific bConfigurationValue in the idx output parameter, or -1
* if the config was not found.
* returns 0 on success or a LIBUSB_ERROR code
*/
int usbi_get_config_index_by_value(struct libusb_device *dev,
uint8_t bConfigurationValue, int *idx)
{
uint8_t i;
usbi_dbg("value %d", bConfigurationValue);
for (i = 0; i < dev->num_configurations; i++) {
unsigned char tmp[6];
int host_endian;
int r = usbi_backend->get_config_descriptor(dev, i, tmp, sizeof(tmp),
&host_endian);
if (r < 0) {
*idx = -1;
return r;
}
if (tmp[5] == bConfigurationValue) {
*idx = i;
return 0;
}
}
*idx = -1;
return 0;
}
/** \ingroup desc
* Get a USB configuration descriptor with a specific bConfigurationValue.
* This is a non-blocking function which does not involve any requests being
* sent to the device.
*
* \param dev a device
* \param bConfigurationValue the bConfigurationValue of the configuration you
* wish to retrieve
* \param config output location for the USB configuration descriptor. Only
* valid if 0 was returned. Must be freed with libusb_free_config_descriptor()
* after use.
* \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_config_descriptor()
* \see libusb_get_config_descriptor()
*/
int API_EXPORTED libusb_get_config_descriptor_by_value(libusb_device *dev,
uint8_t bConfigurationValue, struct libusb_config_descriptor **config)
{
int r, idx, host_endian;
unsigned char *buf = NULL;
if (usbi_backend->get_config_descriptor_by_value) {
r = usbi_backend->get_config_descriptor_by_value(dev,
bConfigurationValue, &buf, &host_endian);
if (r < 0)
return r;
return raw_desc_to_config(dev->ctx, buf, r, host_endian, config);
}
r = usbi_get_config_index_by_value(dev, bConfigurationValue, &idx);
if (r < 0)
return r;
else if (idx == -1)
return LIBUSB_ERROR_NOT_FOUND;
else
return libusb_get_config_descriptor(dev, (uint8_t) idx, config);
}
/** \ingroup desc
* Free a configuration descriptor obtained from
* libusb_get_active_config_descriptor() or libusb_get_config_descriptor().
* It is safe to call this function with a NULL config parameter, in which
* case the function simply returns.
*
* \param config the configuration descriptor to free
*/
void API_EXPORTED libusb_free_config_descriptor(
struct libusb_config_descriptor *config)
{
if (!config)
return;
clear_configuration(config);
free(config);
}
/** \ingroup desc
* Get an endpoints superspeed endpoint companion descriptor (if any)
*
* \param ctx the context to operate on, or NULL for the default context
* \param endpoint endpoint descriptor from which to get the superspeed
* endpoint companion descriptor
* \param ep_comp output location for the superspeed endpoint companion
* descriptor. Only valid if 0 was returned. Must be freed with
* libusb_free_ss_endpoint_companion_descriptor() after use.
* \returns 0 on success
* \returns LIBUSB_ERROR_NOT_FOUND if the configuration does not exist
* \returns another LIBUSB_ERROR code on error
*/
int API_EXPORTED libusb_get_ss_endpoint_companion_descriptor(
struct libusb_context *ctx,
const struct libusb_endpoint_descriptor *endpoint,
struct libusb_ss_endpoint_companion_descriptor **ep_comp)
{
struct usb_descriptor_header header;
int size = endpoint->extra_length;
const unsigned char *buffer = endpoint->extra;
*ep_comp = NULL;
while (size >= DESC_HEADER_LENGTH) {
usbi_parse_descriptor(buffer, "bb", &header, 0);
if (header.bLength < 2 || header.bLength > size) {
usbi_err(ctx, "invalid descriptor length %d",
header.bLength);
return LIBUSB_ERROR_IO;
}
if (header.bDescriptorType != LIBUSB_DT_SS_ENDPOINT_COMPANION) {
buffer += header.bLength;
size -= header.bLength;
continue;
}
if (header.bLength < LIBUSB_DT_SS_ENDPOINT_COMPANION_SIZE) {
usbi_err(ctx, "invalid ss-ep-comp-desc length %d",
header.bLength);
return LIBUSB_ERROR_IO;
}
*ep_comp = malloc(sizeof(**ep_comp));
if (*ep_comp == NULL)
return LIBUSB_ERROR_NO_MEM;
usbi_parse_descriptor(buffer, "bbbbw", *ep_comp, 0);
return LIBUSB_SUCCESS;
}
return LIBUSB_ERROR_NOT_FOUND;
}
/** \ingroup desc
* Free a superspeed endpoint companion descriptor obtained from
* libusb_get_ss_endpoint_companion_descriptor().
* It is safe to call this function with a NULL ep_comp parameter, in which
* case the function simply returns.
*
* \param ep_comp the superspeed endpoint companion descriptor to free
*/
void API_EXPORTED libusb_free_ss_endpoint_companion_descriptor(
struct libusb_ss_endpoint_companion_descriptor *ep_comp)
{
free(ep_comp);
}
static int parse_bos(struct libusb_context *ctx,
struct libusb_bos_descriptor **bos,
unsigned char *buffer, int size, int host_endian)
{
struct libusb_bos_descriptor bos_header, *_bos;
struct libusb_bos_dev_capability_descriptor dev_cap;
int i;
if (size < LIBUSB_DT_BOS_SIZE) {
usbi_err(ctx, "short bos descriptor read %d/%d",
size, LIBUSB_DT_BOS_SIZE);
return LIBUSB_ERROR_IO;
}
usbi_parse_descriptor(buffer, "bbwb", &bos_header, host_endian);
if (bos_header.bDescriptorType != LIBUSB_DT_BOS) {
usbi_err(ctx, "unexpected descriptor %x (expected %x)",
bos_header.bDescriptorType, LIBUSB_DT_BOS);
return LIBUSB_ERROR_IO;
}
if (bos_header.bLength < LIBUSB_DT_BOS_SIZE) {
usbi_err(ctx, "invalid bos bLength (%d)", bos_header.bLength);
return LIBUSB_ERROR_IO;
}
if (bos_header.bLength > size) {
usbi_err(ctx, "short bos descriptor read %d/%d",
size, bos_header.bLength);
return LIBUSB_ERROR_IO;
}
_bos = calloc (1,
sizeof(*_bos) + bos_header.bNumDeviceCaps * sizeof(void *));
if (!_bos)
return LIBUSB_ERROR_NO_MEM;
usbi_parse_descriptor(buffer, "bbwb", _bos, host_endian);
buffer += bos_header.bLength;
size -= bos_header.bLength;
/* Get the device capability descriptors */
for (i = 0; i < bos_header.bNumDeviceCaps; i++) {
if (size < LIBUSB_DT_DEVICE_CAPABILITY_SIZE) {
usbi_warn(ctx, "short dev-cap descriptor read %d/%d",
size, LIBUSB_DT_DEVICE_CAPABILITY_SIZE);
break;
}
usbi_parse_descriptor(buffer, "bbb", &dev_cap, host_endian);
if (dev_cap.bDescriptorType != LIBUSB_DT_DEVICE_CAPABILITY) {
usbi_warn(ctx, "unexpected descriptor %x (expected %x)",
dev_cap.bDescriptorType, LIBUSB_DT_DEVICE_CAPABILITY);
break;
}
if (dev_cap.bLength < LIBUSB_DT_DEVICE_CAPABILITY_SIZE) {
usbi_err(ctx, "invalid dev-cap bLength (%d)",
dev_cap.bLength);
libusb_free_bos_descriptor(_bos);
return LIBUSB_ERROR_IO;
}
if (dev_cap.bLength > size) {
usbi_warn(ctx, "short dev-cap descriptor read %d/%d",
size, dev_cap.bLength);
break;
}
_bos->dev_capability[i] = malloc(dev_cap.bLength);
if (!_bos->dev_capability[i]) {
libusb_free_bos_descriptor(_bos);
return LIBUSB_ERROR_NO_MEM;
}
memcpy(_bos->dev_capability[i], buffer, dev_cap.bLength);
buffer += dev_cap.bLength;
size -= dev_cap.bLength;
}
_bos->bNumDeviceCaps = (uint8_t)i;
*bos = _bos;
return LIBUSB_SUCCESS;
}
/** \ingroup desc
* Get a Binary Object Store (BOS) descriptor
* This is a BLOCKING function, which will send requests to the device.
*
* \param handle the handle of an open libusb device
* \param bos output location for the BOS descriptor. Only valid if 0 was returned.
* Must be freed with \ref libusb_free_bos_descriptor() after use.
* \returns 0 on success
* \returns LIBUSB_ERROR_NOT_FOUND if the device doesn't have a BOS descriptor
* \returns another LIBUSB_ERROR code on error
*/
int API_EXPORTED libusb_get_bos_descriptor(libusb_device_handle *handle,
struct libusb_bos_descriptor **bos)
{
struct libusb_bos_descriptor _bos;
uint8_t bos_header[LIBUSB_DT_BOS_SIZE] = {0};
unsigned char *bos_data = NULL;
const int host_endian = 0;
int r;
/* Read the BOS. This generates 2 requests on the bus,
* one for the header, and one for the full BOS */
r = libusb_get_descriptor(handle, LIBUSB_DT_BOS, 0, bos_header,
LIBUSB_DT_BOS_SIZE);
if (r < 0) {
if (r != LIBUSB_ERROR_PIPE)
usbi_err(handle->dev->ctx, "failed to read BOS (%d)", r);
return r;
}
if (r < LIBUSB_DT_BOS_SIZE) {
usbi_err(handle->dev->ctx, "short BOS read %d/%d",
r, LIBUSB_DT_BOS_SIZE);
return LIBUSB_ERROR_IO;
}
usbi_parse_descriptor(bos_header, "bbwb", &_bos, host_endian);
usbi_dbg("found BOS descriptor: size %d bytes, %d capabilities",
_bos.wTotalLength, _bos.bNumDeviceCaps);
bos_data = calloc(_bos.wTotalLength, 1);
if (bos_data == NULL)
return LIBUSB_ERROR_NO_MEM;
r = libusb_get_descriptor(handle, LIBUSB_DT_BOS, 0, bos_data,
_bos.wTotalLength);
if (r >= 0)
r = parse_bos(handle->dev->ctx, bos, bos_data, r, host_endian);
else
usbi_err(handle->dev->ctx, "failed to read BOS (%d)", r);
free(bos_data);
return r;
}
/** \ingroup desc
* Free a BOS descriptor obtained from libusb_get_bos_descriptor().
* It is safe to call this function with a NULL bos parameter, in which
* case the function simply returns.
*
* \param bos the BOS descriptor to free
*/
void API_EXPORTED libusb_free_bos_descriptor(struct libusb_bos_descriptor *bos)
{
int i;
if (!bos)
return;
for (i = 0; i < bos->bNumDeviceCaps; i++)
free(bos->dev_capability[i]);
free(bos);
}
/** \ingroup desc
* Get an USB 2.0 Extension descriptor
*
* \param ctx the context to operate on, or NULL for the default context
* \param dev_cap Device Capability descriptor with a bDevCapabilityType of
* \ref libusb_capability_type::LIBUSB_BT_USB_2_0_EXTENSION
* LIBUSB_BT_USB_2_0_EXTENSION
* \param usb_2_0_extension output location for the USB 2.0 Extension
* descriptor. Only valid if 0 was returned. Must be freed with
* libusb_free_usb_2_0_extension_descriptor() after use.
* \returns 0 on success
* \returns a LIBUSB_ERROR code on error
*/
int API_EXPORTED libusb_get_usb_2_0_extension_descriptor(
struct libusb_context *ctx,
struct libusb_bos_dev_capability_descriptor *dev_cap,
struct libusb_usb_2_0_extension_descriptor **usb_2_0_extension)
{
struct libusb_usb_2_0_extension_descriptor *_usb_2_0_extension;
const int host_endian = 0;
if (dev_cap->bDevCapabilityType != LIBUSB_BT_USB_2_0_EXTENSION) {
usbi_err(ctx, "unexpected bDevCapabilityType %x (expected %x)",
dev_cap->bDevCapabilityType,
LIBUSB_BT_USB_2_0_EXTENSION);
return LIBUSB_ERROR_INVALID_PARAM;
}
if (dev_cap->bLength < LIBUSB_BT_USB_2_0_EXTENSION_SIZE) {
usbi_err(ctx, "short dev-cap descriptor read %d/%d",
dev_cap->bLength, LIBUSB_BT_USB_2_0_EXTENSION_SIZE);
return LIBUSB_ERROR_IO;
}
_usb_2_0_extension = malloc(sizeof(*_usb_2_0_extension));
if (!_usb_2_0_extension)
return LIBUSB_ERROR_NO_MEM;
usbi_parse_descriptor((unsigned char *)dev_cap, "bbbd",
_usb_2_0_extension, host_endian);
*usb_2_0_extension = _usb_2_0_extension;
return LIBUSB_SUCCESS;
}
/** \ingroup desc
* Free a USB 2.0 Extension descriptor obtained from
* libusb_get_usb_2_0_extension_descriptor().
* It is safe to call this function with a NULL usb_2_0_extension parameter,
* in which case the function simply returns.
*
* \param usb_2_0_extension the USB 2.0 Extension descriptor to free
*/
void API_EXPORTED libusb_free_usb_2_0_extension_descriptor(
struct libusb_usb_2_0_extension_descriptor *usb_2_0_extension)
{
free(usb_2_0_extension);
}
/** \ingroup desc
* Get a SuperSpeed USB Device Capability descriptor
*
* \param ctx the context to operate on, or NULL for the default context
* \param dev_cap Device Capability descriptor with a bDevCapabilityType of
* \ref libusb_capability_type::LIBUSB_BT_SS_USB_DEVICE_CAPABILITY
* LIBUSB_BT_SS_USB_DEVICE_CAPABILITY
* \param ss_usb_device_cap output location for the SuperSpeed USB Device
* Capability descriptor. Only valid if 0 was returned. Must be freed with
* libusb_free_ss_usb_device_capability_descriptor() after use.
* \returns 0 on success
* \returns a LIBUSB_ERROR code on error
*/
int API_EXPORTED libusb_get_ss_usb_device_capability_descriptor(
struct libusb_context *ctx,
struct libusb_bos_dev_capability_descriptor *dev_cap,
struct libusb_ss_usb_device_capability_descriptor **ss_usb_device_cap)
{
struct libusb_ss_usb_device_capability_descriptor *_ss_usb_device_cap;
const int host_endian = 0;
if (dev_cap->bDevCapabilityType != LIBUSB_BT_SS_USB_DEVICE_CAPABILITY) {
usbi_err(ctx, "unexpected bDevCapabilityType %x (expected %x)",
dev_cap->bDevCapabilityType,
LIBUSB_BT_SS_USB_DEVICE_CAPABILITY);
return LIBUSB_ERROR_INVALID_PARAM;
}
if (dev_cap->bLength < LIBUSB_BT_SS_USB_DEVICE_CAPABILITY_SIZE) {
usbi_err(ctx, "short dev-cap descriptor read %d/%d",
dev_cap->bLength, LIBUSB_BT_SS_USB_DEVICE_CAPABILITY_SIZE);
return LIBUSB_ERROR_IO;
}
_ss_usb_device_cap = malloc(sizeof(*_ss_usb_device_cap));
if (!_ss_usb_device_cap)
return LIBUSB_ERROR_NO_MEM;
usbi_parse_descriptor((unsigned char *)dev_cap, "bbbbwbbw",
_ss_usb_device_cap, host_endian);
*ss_usb_device_cap = _ss_usb_device_cap;
return LIBUSB_SUCCESS;
}
/** \ingroup desc
* Free a SuperSpeed USB Device Capability descriptor obtained from
* libusb_get_ss_usb_device_capability_descriptor().
* It is safe to call this function with a NULL ss_usb_device_cap
* parameter, in which case the function simply returns.
*
* \param ss_usb_device_cap the USB 2.0 Extension descriptor to free
*/
void API_EXPORTED libusb_free_ss_usb_device_capability_descriptor(
struct libusb_ss_usb_device_capability_descriptor *ss_usb_device_cap)
{
free(ss_usb_device_cap);
}
/** \ingroup desc
* Get a Container ID descriptor
*
* \param ctx the context to operate on, or NULL for the default context
* \param dev_cap Device Capability descriptor with a bDevCapabilityType of
* \ref libusb_capability_type::LIBUSB_BT_CONTAINER_ID
* LIBUSB_BT_CONTAINER_ID
* \param container_id output location for the Container ID descriptor.
* Only valid if 0 was returned. Must be freed with
* libusb_free_container_id_descriptor() after use.
* \returns 0 on success
* \returns a LIBUSB_ERROR code on error
*/
int API_EXPORTED libusb_get_container_id_descriptor(struct libusb_context *ctx,
struct libusb_bos_dev_capability_descriptor *dev_cap,
struct libusb_container_id_descriptor **container_id)
{
struct libusb_container_id_descriptor *_container_id;
const int host_endian = 0;
if (dev_cap->bDevCapabilityType != LIBUSB_BT_CONTAINER_ID) {
usbi_err(ctx, "unexpected bDevCapabilityType %x (expected %x)",
dev_cap->bDevCapabilityType,
LIBUSB_BT_CONTAINER_ID);
return LIBUSB_ERROR_INVALID_PARAM;
}
if (dev_cap->bLength < LIBUSB_BT_CONTAINER_ID_SIZE) {
usbi_err(ctx, "short dev-cap descriptor read %d/%d",
dev_cap->bLength, LIBUSB_BT_CONTAINER_ID_SIZE);
return LIBUSB_ERROR_IO;
}
_container_id = malloc(sizeof(*_container_id));
if (!_container_id)
return LIBUSB_ERROR_NO_MEM;
usbi_parse_descriptor((unsigned char *)dev_cap, "bbbbu",
_container_id, host_endian);
*container_id = _container_id;
return LIBUSB_SUCCESS;
}
/** \ingroup desc
* Free a Container ID descriptor obtained from
* libusb_get_container_id_descriptor().
* It is safe to call this function with a NULL container_id parameter,
* in which case the function simply returns.
*
* \param container_id the USB 2.0 Extension descriptor to free
*/
void API_EXPORTED libusb_free_container_id_descriptor(
struct libusb_container_id_descriptor *container_id)
{
free(container_id);
}
/** \ingroup desc
* Retrieve a string descriptor in C style ASCII.
*
* Wrapper around libusb_get_string_descriptor(). Uses the first language
* supported by the device.
*
* \param dev a device handle
* \param desc_index the index of the descriptor to retrieve
* \param data output buffer for ASCII string descriptor
* \param length size of data buffer
* \returns number of bytes returned in data, or LIBUSB_ERROR code on failure
*/
int API_EXPORTED libusb_get_string_descriptor_ascii(libusb_device_handle *dev,
uint8_t desc_index, unsigned char *data, int length)
{
unsigned char tbuf[255]; /* Some devices choke on size > 255 */
int r, si, di;
uint16_t langid;
/* Asking for the zero'th index is special - it returns a string
* descriptor that contains all the language IDs supported by the
* device. Typically there aren't many - often only one. Language
* IDs are 16 bit numbers, and they start at the third byte in the
* descriptor. There's also no point in trying to read descriptor 0
* with this function. See USB 2.0 specification section 9.6.7 for
* more information.
*/
if (desc_index == 0)
return LIBUSB_ERROR_INVALID_PARAM;
r = libusb_get_string_descriptor(dev, 0, 0, tbuf, sizeof(tbuf));
if (r < 0)
return r;
if (r < 4)
return LIBUSB_ERROR_IO;
langid = tbuf[2] | (tbuf[3] << 8);
r = libusb_get_string_descriptor(dev, desc_index, langid, tbuf,
sizeof(tbuf));
if (r < 0)
return r;
if (tbuf[1] != LIBUSB_DT_STRING)
return LIBUSB_ERROR_IO;
if (tbuf[0] > r)
return LIBUSB_ERROR_IO;
for (di = 0, si = 2; si < tbuf[0]; si += 2) {
if (di >= (length - 1))
break;
if ((tbuf[si] & 0x80) || (tbuf[si + 1])) /* non-ASCII */
data[di++] = '?';
else
data[di++] = tbuf[si];
}
data[di] = 0;
return di;
}
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