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/* $FreeBSD$ */
/*-
* Copyright (c) 2008 Hans Petter Selasky. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <dev/usb/usb.h>
#include <dev/usb/usb_mfunc.h>
#include <dev/usb/usb_core.h>
#include <dev/usb/usb_parse.h>
/*------------------------------------------------------------------------*
* usb_desc_foreach
*
* This function is the safe way to iterate across the USB config
* descriptor. It contains several checks against invalid
* descriptors. If the "desc" argument passed to this function is
* "NULL" the first descriptor, if any, will be returned.
*
* Return values:
* NULL: End of descriptors
* Else: Next descriptor after "desc"
*------------------------------------------------------------------------*/
struct usb_descriptor *
usb_desc_foreach(struct usb_config_descriptor *cd,
struct usb_descriptor *_desc)
{
uint8_t *desc_next;
uint8_t *start;
uint8_t *end;
uint8_t *desc;
/* be NULL safe */
if (cd == NULL)
return (NULL);
/* We assume that the "wTotalLength" has been checked. */
start = (uint8_t *)cd;
end = start + UGETW(cd->wTotalLength);
desc = (uint8_t *)_desc;
/* Get start of next USB descriptor. */
if (desc == NULL)
desc = start;
else
desc = desc + desc[0];
/* Check that the next USB descriptor is within the range. */
if ((desc < start) || (desc >= end))
return (NULL); /* out of range, or EOD */
/* Check that the second next USB descriptor is within range. */
desc_next = desc + desc[0];
if ((desc_next < start) || (desc_next > end))
return (NULL); /* out of range */
/* Check minimum descriptor length. */
if (desc[0] < 3)
return (NULL); /* too short descriptor */
/* Return start of next descriptor. */
return ((struct usb_descriptor *)desc);
}
/*------------------------------------------------------------------------*
* usb_idesc_foreach
*
* This function will iterate the interface descriptors in the config
* descriptor. The parse state structure should be zeroed before
* calling this function the first time.
*
* Return values:
* NULL: End of descriptors
* Else: A valid interface descriptor
*------------------------------------------------------------------------*/
struct usb_interface_descriptor *
usb_idesc_foreach(struct usb_config_descriptor *cd,
struct usb_idesc_parse_state *ps)
{
struct usb_interface_descriptor *id;
uint8_t new_iface;
/* retrieve current descriptor */
id = (struct usb_interface_descriptor *)ps->desc;
/* default is to start a new interface */
new_iface = 1;
while (1) {
id = (struct usb_interface_descriptor *)
usb_desc_foreach(cd, (struct usb_descriptor *)id);
if (id == NULL)
break;
if ((id->bDescriptorType == UDESC_INTERFACE) &&
(id->bLength >= sizeof(*id))) {
if (ps->iface_no_last == id->bInterfaceNumber)
new_iface = 0;
ps->iface_no_last = id->bInterfaceNumber;
break;
}
}
if (ps->desc == NULL) {
/* first time */
} else if (new_iface) {
/* new interface */
ps->iface_index ++;
ps->iface_index_alt = 0;
} else {
/* new alternate interface */
ps->iface_index_alt ++;
}
/* store and return current descriptor */
ps->desc = (struct usb_descriptor *)id;
return (id);
}
/*------------------------------------------------------------------------*
* usb_edesc_foreach
*
* This function will iterate all the endpoint descriptors within an
* interface descriptor. Starting value for the "ped" argument should
* be a valid interface descriptor.
*
* Return values:
* NULL: End of descriptors
* Else: A valid endpoint descriptor
*------------------------------------------------------------------------*/
struct usb_endpoint_descriptor *
usb_edesc_foreach(struct usb_config_descriptor *cd,
struct usb_endpoint_descriptor *ped)
{
struct usb_descriptor *desc;
desc = ((struct usb_descriptor *)ped);
while ((desc = usb_desc_foreach(cd, desc))) {
if (desc->bDescriptorType == UDESC_INTERFACE) {
break;
}
if (desc->bDescriptorType == UDESC_ENDPOINT) {
if (desc->bLength < sizeof(*ped)) {
/* endpoint index is invalid */
break;
}
return ((struct usb_endpoint_descriptor *)desc);
}
}
return (NULL);
}
/*------------------------------------------------------------------------*
* usbd_get_no_descriptors
*
* This function will count the total number of descriptors in the
* configuration descriptor of type "type".
*------------------------------------------------------------------------*/
uint8_t
usbd_get_no_descriptors(struct usb_config_descriptor *cd, uint8_t type)
{
struct usb_descriptor *desc = NULL;
uint8_t count = 0;
while ((desc = usb_desc_foreach(cd, desc))) {
if (desc->bDescriptorType == type) {
count++;
if (count == 0xFF)
break; /* crazy */
}
}
return (count);
}
/*------------------------------------------------------------------------*
* usbd_get_no_alts
*
* Return value:
* Number of alternate settings for the given interface descriptor pointer.
*------------------------------------------------------------------------*/
uint8_t
usbd_get_no_alts(struct usb_config_descriptor *cd,
struct usb_interface_descriptor *id)
{
struct usb_descriptor *desc;
uint8_t n = 0;
uint8_t ifaceno;
ifaceno = id->bInterfaceNumber;
desc = (struct usb_descriptor *)id;
while ((desc = usb_desc_foreach(cd, desc))) {
if ((desc->bDescriptorType == UDESC_INTERFACE) &&
(desc->bLength >= sizeof(*id))) {
id = (struct usb_interface_descriptor *)desc;
if (id->bInterfaceNumber == ifaceno) {
n++;
if (n == 0xFF)
break; /* crazy */
} else
break; /* end */
}
}
return (n);
}
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