#include <linux/usb.h>
#include <linux/usb/ch9.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/device.h>
#include <asm/byteorder.h>
#include "usb.h"
#include "hcd.h"
#define USB_MAXALTSETTING 128 /* Hard limit */
#define USB_MAXENDPOINTS 30 /* Hard limit */
#define USB_MAXCONFIG 8 /* Arbitrary limit */
static inline const char *plural(int n)
{
return (n == 1 ? "" : "s");
}
/* FIXME: this is a kludge */
static int find_next_descriptor_more(unsigned char *buffer, int size,
int dt1, int dt2, int dt3, int *num_skipped)
{
struct usb_descriptor_header *h;
int n = 0;
unsigned char *buffer0 = buffer;
/* Find the next descriptor of type dt1 or dt2 or dt3 */
while (size > 0) {
h = (struct usb_descriptor_header *) buffer;
if (h->bDescriptorType == dt1 || h->bDescriptorType == dt2 ||
h->bDescriptorType == dt3)
break;
buffer += h->bLength;
size -= h->bLength;
++n;
}
/* Store the number of descriptors skipped and return the
* number of bytes skipped */
if (num_skipped)
*num_skipped = n;
return buffer - buffer0;
}
static int find_next_descriptor(unsigned char *buffer, int size,
int dt1, int dt2, int *num_skipped)
{
struct usb_descriptor_header *h;
int n = 0;
unsigned char *buffer0 = buffer;
/* Find the next descriptor of type dt1 or dt2 */
while (size > 0) {
h = (struct usb_descriptor_header *) buffer;
if (h->bDescriptorType == dt1 || h->bDescriptorType == dt2)
break;
buffer += h->bLength;
size -= h->bLength;
++n;
}
/* Store the number of descriptors skipped and return the
* number of bytes skipped */
if (num_skipped)
*num_skipped = n;
return buffer - buffer0;
}
static int usb_parse_ss_endpoint_companion(struct device *ddev, int cfgno,
int inum, int asnum, struct usb_host_endpoint *ep,
int num_ep, unsigned char *buffer, int size)
{
unsigned char *buffer_start = buffer;
struct usb_ss_ep_comp_descriptor *desc;
int retval;
int num_skipped;
int max_tx;
int i;
/* Allocate space for the SS endpoint companion descriptor */
ep->ss_ep_comp = kzalloc(sizeof(struct usb_host_ss_ep_comp),
GFP_KERNEL);
if (!ep->ss_ep_comp)
return -ENOMEM;
desc = (struct usb_ss_ep_comp_descriptor *) buffer;
if (desc->bDescriptorType != USB_DT_SS_ENDPOINT_COMP) {
dev_warn(ddev, "No SuperSpeed endpoint companion for config %d "
" interface %d altsetting %d ep %d: "
"using minimum values\n",
cfgno, inum, asnum, ep->desc.bEndpointAddress);
ep->ss_ep_comp->desc.bLength = USB_DT_SS_EP_COMP_SIZE;
ep->ss_ep_comp->desc.bDescriptorType = USB_DT_SS_ENDPOINT_COMP;
ep->ss_ep_comp->desc.bMaxBurst = 0;
/*
* Leave bmAttributes as zero, which will mean no streams for
* bulk, and isoc won't support multiple bursts of packets.
* With bursts of only one packet, and a Mult of 1, the max
* amount of data moved per endpoint service interval is one
* packet.
*/
if (usb_endpoint_xfer_isoc(&ep->desc) ||
usb_endpoint_xfer_int(&ep->desc))
ep->ss_ep_comp->desc.wBytesPerInterval =
ep->desc.wMaxPacketSize;
/*
* The next descriptor is for an Endpoint or Interface,
* no extra descriptors to copy into the companion structure,
* and we didn't eat up any of the buffer.
*/
retval = 0;
goto valid;
}
memcpy(&ep->ss_ep_comp->desc, desc, USB_DT_SS_EP_COMP_SIZE);
desc = &ep->ss_ep_comp->desc;
buffer += desc->bLength;
size -= desc->bLength;
/* Eat up the other descriptors we don't care about */
ep->ss_ep_comp->extra = buffer;
i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
USB_DT_INTERFACE, &num_skipped);
ep->ss_ep_comp->extralen = i;
buffer += i;
size -= i;
retval = buffer - buffer_start + i;
if (num_skipped > 0)
dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
num_skipped, plural(num_skipped),
"SuperSpeed endpoint companion");
/* Check the various values */
if (usb_endpoint_xfer_control(&ep->desc) && desc->bMaxBurst != 0) {
dev_warn(ddev, "Control endpoint with bMaxBurst = %d in "
"config %d interface %d altsetting %d ep %d: "
"setting to zero\n", desc->bMaxBurst,
cfgno, inum, asnum, ep->desc.bEndpointAddress);
desc->bMaxBurst = 0;
}
if (desc->bMaxBurst > 15) {
dev_warn(ddev, "Endpoint with bMaxBurst = %d in "
"config %d interface %d altsetting %d ep %d: "
"setting to 15\n", desc->bMaxBurst,
cfgno, inum, asnum, ep->desc.bEndpointAddress);
desc->bMaxBurst = 15;
}
if ((usb_endpoint_xfer_control(&ep->desc) || usb_endpoint_xfer_int(&ep->desc))
&& desc->bmAttributes != 0) {
dev_warn(ddev, "%s endpoint with bmAttributes = %d in "
"config %d interface %d altsetting %d ep %d: "
"setting to zero\n",
usb_endpoint_xfer_control(&ep->desc) ? "Control" : "Bulk",
desc->bmAttributes,
cfgno, inum, asnum, ep->desc.bEndpointAddress);
desc->bmAttributes = 0;
}
if (usb_endpoint_xfer_bulk(&ep->desc) && desc->bmAttributes > 16) {
dev_warn(ddev, "Bulk endpoint with more than 65536 streams in "
"config %d interface %d altsetting %d ep %d: "
"setting to max\n",
cfgno, inum, asnum, ep->desc.bEndpointAddress);
desc->bmAttributes = 16;
}
if (usb_endpoint_xfer_isoc(&ep->desc) && desc->bmAttributes > 2) {
dev_warn(ddev, "Isoc endpoint has Mult of %d in "
"config %d interface %d altsetting %d ep %d: "
"setting to 3\n", desc->bmAttributes + 1,
cfgno, inum, asnum, ep->desc.bEndpointAddress);
desc->bmAttributes = 2;
}
if (usb_endpoint_xfer_isoc(&ep->desc)) {
max_tx = ep->desc.wMaxPacketSize * (desc->bMaxBurst + 1) *
(desc->bmAttributes + 1);
} else if (usb_endpoint_xfer_int(&ep->desc)) {
max_tx = ep->desc.wMaxPacketSize * (desc->bMaxBurst + 1);
} else {
goto valid;
}
if (desc->wBytesPerInterval > max_tx) {
dev_warn(ddev, "%s endpoint with wBytesPerInterval of %d in "
"config %d interface %d altsetting %d ep %d: "
"setting to %d\n",
usb_endpoint_xfer_isoc(&ep->desc) ? "Isoc" : "Int",
desc->wBytesPerInterval,
cfgno, inum, asnum, ep->desc.bEndpointAddress,
max_tx);
desc->wBytesPerInterval = max_tx;
}
valid:
return retval;
}
static int usb_parse_endpoint(struct device *ddev, int cfgno, int inum,
int asnum, struct usb_host_interface *ifp, int num_ep,
unsigned char *buffer, int size)
{
unsigned char *buffer0 = buffer;
struct usb_endpoint_descriptor *d;
struct usb_host_endpoint *endpoint;
int n, i, j, retval;
d = (struct usb_endpoint_descriptor *) buffer;
buffer += d->bLength;
size -= d->bLength;
if (d->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE)
n = USB_DT_ENDPOINT_AUDIO_SIZE;
else if (d->bLength >= USB_DT_ENDPOINT_SIZE)
n = USB_DT_ENDPOINT_SIZE;
else {
dev_warn(ddev, "config %d interface %d altsetting %d has an "
"invalid endpoint descriptor of length %d, skipping\n",
cfgno, inum, asnum, d->bLength);
goto skip_to_next_endpoint_or_interface_descriptor;
}
i = d->bEndpointAddress & ~USB_ENDPOINT_DIR_MASK;
if (i >= 16 || i == 0) {
dev_warn(ddev, "config %d interface %d altsetting %d has an "
"invalid endpoint with address 0x%X, skipping\n",
cfgno, inum, asnum, d->bEndpointAddress);
goto skip_to_next_endpoint_or_interface_descriptor;
}
/* Only store as many endpoints as we have room for */
if (ifp->desc.bNumEndpoints >= num_ep)
goto skip_to_next_endpoint_or_interface_descriptor;
endpoint = &ifp->endpoint[ifp->desc.bNumEndpoints];
++ifp->desc.bNumEndpoints;
memcpy(&endpoint->desc, d, n);
INIT_LIST_HEAD(&endpoint->urb_list);
/* Fix up bInterval values outside the legal range. Use 32 ms if no
* proper value can be guessed. */
i = 0; /* i = min, j = max, n = default */
j = 255;
if (usb_endpoint_xfer_int(d)) {
i = 1;
switch (to_usb_device(ddev)->speed) {
case USB_SPEED_SUPER:
case USB_SPEED_HIGH:
/* Many device manufacturers are using full-speed
* bInterval values in high-speed interrupt endpoint
* descriptors. Try to fix those and fall back to a
* 32 ms default value otherwise. */
n = fls(d->bInterval*8);
if (n == 0)
n = 9; /* 32 ms = 2^(9-1) uframes */
j = 16;
break;
default: /* USB_SPEED_FULL or _LOW */
/* For low-speed, 10 ms is the official minimum.
* But some "overclocked" devices might want faster
* polling so we'll allow it. */
n = 32;
break;
}
} else if (usb_endpoint_xfer_isoc(d)) {
i = 1;
j = 16;
switch (to_usb_device(ddev)->speed) {
case USB_SPEED_HIGH:
n = 9; /* 32 ms = 2^(9-1) uframes */
break;
default: /* USB_SPEED_FULL */
n = 6; /* 32 ms = 2^(6-1) frames */
break;
}
}
if (d->bInterval < i || d->bInterval > j) {
dev_warn(ddev, "config %d interface %d altsetting %d "
"endpoint 0x%X has an invalid bInterval %d, "
"changing to %d\n",
cfgno, inum, asnum,
d->bEndpointAddress, d->bInterval, n);
endpoint->desc.bInterval = n;
}
/* Some buggy low-speed devices have Bulk endpoints, which is
* explicitly forbidden by the USB spec. In an attempt to make
* them usable, we will try treating them as Interrupt endpoints.
*/
if (to_usb_device(ddev)->speed == USB_SPEED_LOW &&
usb_endpoint_xfer_bulk(d)) {
dev_warn(ddev, "config %d interface %d altsetting %d "
"endpoint 0x%X is Bulk; changing to Interrupt\n",
cfgno, inum, asnum, d->bEndpointAddress);
endpoint->desc.bmAttributes = USB_ENDPOINT_XFER_INT;
endpoint->desc.bInterval = 1;
if (le16_to_cpu(endpoint->desc.wMaxPacketSize) > 8)
endpoint->desc.wMaxPacketSize = cpu_to_le16(8);
}
/*
* Some buggy high speed devices have bulk endpoints using
* maxpacket sizes other than 512. High speed HCDs may not
* be able to handle that particular bug, so let's warn...
*/
if (to_usb_device(ddev)->speed == USB_SPEED_HIGH
&& usb_endpoint_xfer_bulk(d)) {
unsigned maxp;
maxp = le16_to_cpu(endpoint->desc.wMaxPacketSize) & 0x07ff;
if (maxp != 512)
dev_warn(ddev, "config %d interface %d altsetting %d "
"bulk endpoint 0x%X has invalid maxpacket %d\n",
cfgno, inum, asnum, d->bEndpointAddress,
maxp);
}
/* Allocate room for and parse any SS endpoint companion descriptors */
if (to_usb_device(ddev)->speed == USB_SPEED_SUPER) {
endpoint->extra = buffer;
i = find_next_descriptor_more(buffer, size, USB_DT_SS_ENDPOINT_COMP,
USB_DT_ENDPOINT, USB_DT_INTERFACE, &n);
endpoint->extralen = i;
buffer += i;
size -= i;
if (size > 0) {
retval = usb_parse_ss_endpoint_companion(ddev, cfgno,
inum, asnum, endpoint, num_ep, buffer,
size);
if (retval >= 0) {
buffer += retval;
retval = buffer - buffer0;
}
} else {
retval = buffer - buffer0;
}
} else {
/* Skip over any Class Specific or Vendor Specific descriptors;
* find the next endpoint or interface descriptor */
endpoint->extra = buffer;
i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
USB_DT_INTERFACE, &n);
endpoint->extralen = i;
retval = buffer - buffer0 + i;
}
if (n > 0)
dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
n, plural(n), "endpoint");
return retval;
skip_to_next_endpoint_or_interface_descriptor:
i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
USB_DT_INTERFACE, NULL);
return buffer - buffer0 + i;
}
void usb_release_interface_cache(struct kref *ref)
{
struct usb_interface_cache *intfc = ref_to_usb_interface_cache(ref);
int j;
for (j = 0; j < intfc->num_altsetting; j++) {
struct usb_host_interface *alt = &intfc->altsetting[j];
kfree(alt->endpoint);
kfree(alt->string);
}
kfree(intfc);
}
static int usb_parse_interface(struct device *ddev, int cfgno,
struct usb_host_config *config, unsigned char *buffer, int size,
u8 inums[], u8 nalts[])
{
unsigned char *buffer0 = buffer;
struct usb_interface_descriptor *d;
int inum, asnum;
struct usb_interface_cache *intfc;
struct usb_host_interface *alt;
int i, n;
int len, retval;
int num_ep, num_ep_orig;
d = (struct usb_interface_descriptor *) buffer;
buffer += d->bLength;
size -= d->bLength;
if (d->bLength < USB_DT_INTERFACE_SIZE)
goto skip_to_next_interface_descriptor;
/* Which interface entry is this? */
intfc = NULL;
inum = d->bInterfaceNumber;
for (i = 0; i < config->desc.bNumInterfaces; ++i) {
if (inums[i] == inum) {
intfc = config->intf_cache[i];
break;
}
}
if (!intfc || intfc->num_altsetting >= nalts[i])
goto skip_to_next_interface_descriptor;
/* Check for duplicate altsetting entries */
asnum = d->bAlternateSetting;
for ((i = 0, alt = &intfc->altsetting[0]);
i < intfc->num_altsetting;
(++i, ++alt)) {
if (alt->desc.bAlternateSetting == asnum) {
dev_warn(ddev, "Duplicate descriptor for config %d "
"interface %d altsetting %d, skipping\n",
cfgno, inum, asnum);
goto skip_to_next_interface_descriptor;
}
}
++intfc->num_altsetting;
memcpy(&alt->desc, d, USB_DT_INTERFACE_SIZE);
/* Skip over any Class Specific or Vendor Specific descriptors;
* find the first endpoint or interface descriptor */
alt->extra = buffer;
i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
USB_DT_INTERFACE, &n);
alt->extralen = i;
if (n > 0)
dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
n, plural(n), "interface");
buffer += i;
size -= i;
/* Allocate space for the right(?) number of endpoints */
num_ep = num_ep_orig = alt->desc.bNumEndpoints;
alt->desc.bNumEndpoints = 0; /* Use as a counter */
if (num_ep > USB_MAXENDPOINTS) {
dev_warn(ddev, "too many endpoints for config %d interface %d "
"altsetting %d: %d, using maximum allowed: %d\n",
cfgno, inum, asnum, num_ep, USB_MAXENDPOINTS);
num_ep = USB_MAXENDPOINTS;
}
if (num_ep > 0) {
/* Can't allocate 0 bytes */
len = sizeof(struct usb_host_endpoint) * num_ep;
alt->endpoint = kzalloc(len, GFP_KERNEL);
if (!alt->endpoint)
return -ENOMEM;
}
/* Parse all the endpoint descriptors */
n = 0;
while (size > 0) {
if (((struct usb_descriptor_header *) buffer)->bDescriptorType
== USB_DT_INTERFACE)
break;
retval = usb_parse_endpoint(ddev, cfgno, inum, asnum, alt,
num_ep, buffer, size);
if (retval < 0)
return retval;
++n;
buffer += retval;
size -= retval;
}
if (n != num_ep_orig)
dev_warn(ddev, "config %d interface %d altsetting %d has %d "
"endpoint descriptor%s, different from the interface "
"descriptor's value: %d\n",
cfgno, inum, asnum, n, plural(n), num_ep_orig);
return buffer - buffer0;
skip_to_next_interface_descriptor:
i = find_next_descriptor(buffer, size, USB_DT_INTERFACE,
USB_DT_INTERFACE, NULL);
return buffer - buffer0 + i;
}
static int usb_parse_configuration(struct device *ddev, int cfgidx,
struct usb_host_config *config, unsigned char *buffer, int size)
{
unsigned char *buffer0 = buffer;
int cfgno;
int nintf, nintf_orig;
int i, j, n;
struct usb_interface_cache *intfc;
unsigned char *buffer2;
int size2;
struct usb_descriptor_header *header;
int len, retval;
u8 inums[USB_MAXINTERFACES], nalts[USB_MAXINTERFACES];
unsigned iad_num = 0;
memcpy(&config->desc, buffer, USB_DT_CONFIG_SIZE);
if (config->desc.bDescriptorType != USB_DT_CONFIG ||
config->desc.bLength < USB_DT_CONFIG_SIZE) {
dev_err(ddev, "invalid descriptor for config index %d: "
"type = 0x%X, length = %d\n", cfgidx,
config->desc.bDescriptorType, config->desc.bLength);
return -EINVAL;
}
cfgno = config->desc.bConfigurationValue;
buffer += config->desc.bLength;
size -= config->desc.bLength;
nintf = nintf_orig = config->desc.bNumInterfaces;
if (nintf > USB_MAXINTERFACES) {
dev_warn(ddev, "config %d has too many interfaces: %d, "
"using maximum allowed: %d\n",
cfgno, nintf, USB_MAXINTERFACES);
nintf = USB_MAXINTERFACES;
}
/* Go through the descriptors, checking their length and counting the
* number of altsettings for each interface */
n = 0;
for ((buffer2 = buffer, size2 = size);
size2 > 0;
(buffer2 += header->bLength, size2 -= header->bLength)) {
if (size2 < sizeof(struct usb_descriptor_header)) {
dev_warn(ddev, "config %d descriptor has %d excess "
"byte%s, ignoring\n",
cfgno, size2, plural(size2));
break;
}
header = (struct usb_descriptor_header *) buffer2;
if ((header->bLength > size2) || (header->bLength < 2)) {
dev_warn(ddev, "config %d has an invalid descriptor "
"of length %d, skipping remainder of the config\n",
cfgno, header->bLength);
break;
}
if (header->bDescriptorType == USB_DT_INTERFACE) {
struct usb_interface_descriptor *d;
int inum;
d = (struct usb_interface_descriptor *) header;
if (d->bLength < USB_DT_INTERFACE_SIZE) {
dev_warn(ddev, "config %d has an invalid "
"interface descriptor of length %d, "
"skipping\n", cfgno, d->bLength);
continue;
}
inum = d->bInterfaceNumber;
if (inum >= nintf_orig)
dev_warn(ddev, "config %d has an invalid "
"interface number: %d but max is %d\n",
cfgno, inum, nintf_orig - 1);
/* Have we already encountered this interface?
* Count its altsettings */
for (i = 0; i < n; ++i) {
if (inums[i] == inum)
break;
}
if (i < n) {
if (nalts[i] < 255)
++nalts[i];
} else if (n < USB_MAXINTERFACES) {
inums[n] = inum;
nalts[n] = 1;
++n;
}
} else if (header->bDescriptorType ==
USB_DT_INTERFACE_ASSOCIATION) {
if (iad_num == USB_MAXIADS) {
dev_warn(ddev, "found more Interface "
"Association Descriptors "
"than allocated for in "
"configuration %d\n", cfgno);
} else {
config->intf_assoc[iad_num] =
(struct usb_interface_assoc_descriptor
*)header;
iad_num++;
}
} else if (header->bDescriptorType == USB_DT_DEVICE ||
header->bDescriptorType == USB_DT_CONFIG)
dev_warn(ddev, "config %d contains an unexpected "
"descriptor of type 0x%X, skipping\n",
cfgno, header->bDescriptorType);
} /* for ((buffer2 = buffer, size2 = size); ...) */
size = buffer2 - buffer;
config->desc.wTotalLength = cpu_to_le16(buffer2 - buffer0);
if (n != nintf)
dev_warn(ddev, "config %d has %d interface%s, different from "
"the descriptor's value: %d\n",
cfgno, n, plural(n), nintf_orig);
else if (n == 0)
dev_warn(ddev, "config %d has no interfaces?\n", cfgno);
config->desc.bNumInterfaces = nintf = n;
/* Check for missing interface numbers */
for (i = 0; i < nintf; ++i) {
for (j = 0; j < nintf; ++j) {
if (inums[j] == i)
break;
}
if (j >= nintf)
dev_warn(ddev, "config %d has no interface number "
"%d\n", cfgno, i);
}
/* Allocate the usb_interface_caches and altsetting arrays */
for (i = 0; i < nintf; ++i) {
j = nalts[i];
if (j > USB_MAXALTSETTING) {
dev_warn(ddev, "too many alternate settings for "
"config %d interface %d: %d, "
"using maximum allowed: %d\n",
cfgno, inums[i], j, USB_MAXALTSETTING);
nalts[i] = j = USB_MAXALTSETTING;
}
len = sizeof(*intfc) + sizeof(struct usb_host_interface) * j;
config->intf_cache[i] = intfc = kzalloc(len, GFP_KERNEL);
if (!intfc)
return -ENOMEM;
kref_init(&intfc->ref);
}
/* FIXME: parse the BOS descriptor */
/* Skip over any Class Specific or Vendor Specific descriptors;
* find the first interface descriptor */
config->extra = buffer;
i = find_next_descriptor(buffer, size, USB_DT_INTERFACE,
USB_DT_INTERFACE, &n);
config->extralen = i;
if (n > 0)
dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
n, plural(n), "configuration");
buffer += i;
size -= i;
/* Parse all the interface/altsetting descriptors */
while (size > 0) {
retval = usb_parse_interface(ddev, cfgno, config,
buffer, size, inums, nalts);
if (retval < 0)
return retval;
buffer += retval;
size -= retval;
}
/* Check for missing altsettings */
for (i = 0; i < nintf; ++i) {
intfc = config->intf_cache[i];
for (j = 0; j < intfc->num_altsetting; ++j) {
for (n = 0; n < intfc->num_altsetting; ++n) {
if (intfc->altsetting[n].desc.
bAlternateSetting == j)
break;
}
if (n >= intfc->num_altsetting)
dev_warn(ddev, "config %d interface %d has no "
"altsetting %d\n", cfgno, inums[i], j);
}
}
return 0;
}
/* hub-only!! ... and only exported for reset/reinit path.
* otherwise used internally on disconnect/destroy path
*/
void usb_destroy_configuration(struct usb_device *dev)
{
int c, i;
if (!dev->config)
return;
if (dev->rawdescriptors) {
for (i = 0; i < dev->descriptor.bNumConfigurations; i++)
kfree(dev->rawdescriptors[i]);
kfree(dev->rawdescriptors);
dev->rawdescriptors = NULL;
}
for (c = 0; c < dev->descriptor.bNumConfigurations; c++) {
struct usb_host_config *cf = &dev->config[c];
kfree(cf->string);
for (i = 0; i < cf->desc.bNumInterfaces; i++) {
if (cf->intf_cache[i])
kref_put(&cf->intf_cache[i]->ref,
usb_release_interface_cache);
}
}
kfree(dev->config);
dev->config = NULL;
}
/*
* Get the USB config descriptors, cache and parse'em
*
* hub-only!! ... and only in reset path, or usb_new_device()
* (used by real hubs and virtual root hubs)
*
* NOTE: if this is a WUSB device and is not authorized, we skip the
* whole thing. A non-authorized USB device has no
* configurations.
*/
int usb_get_configuration(struct usb_device *dev)
{
struct device *ddev = &dev->dev;
int ncfg = dev->descriptor.bNumConfigurations;
int result = 0;
unsigned int cfgno, length;
unsigned char *buffer;
unsigned char *bigbuffer;
struct usb_config_descriptor *desc;
cfgno = 0;
if (dev->authorized == 0) /* Not really an error */
goto out_not_authorized;
result = -ENOMEM;
if (ncfg > USB_MAXCONFIG) {
dev_warn(ddev, "too many configurations: %d, "
"using maximum allowed: %d\n", ncfg, USB_MAXCONFIG);
dev->descriptor.bNumConfigurations = ncfg = USB_MAXCONFIG;
}
if (ncfg < 1) {
dev_err(ddev, "no configurations\n");
return -EINVAL;
}
length = ncfg * sizeof(struct usb_host_config);
dev->config = kzalloc(length, GFP_KERNEL);
if (!dev->config)
goto err2;
length = ncfg * sizeof(char *);
dev->rawdescriptors = kzalloc(length, GFP_KERNEL);
if (!dev->rawdescriptors)
goto err2;
buffer = kmalloc(USB_DT_CONFIG_SIZE, GFP_KERNEL);
if (!buffer)
goto err2;
desc = (struct usb_config_descriptor *)buffer;
result = 0;
for (; cfgno < ncfg; cfgno++) {
/* We grab just the first descriptor so we know how long
* the whole configuration is */
result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno,
buffer, USB_DT_CONFIG_SIZE);
if (result < 0) {
dev_err(ddev, "unable to read config index %d "
"descriptor/%s: %d\n", cfgno, "start", result);
dev_err(ddev, "chopping to %d config(s)\n", cfgno);
dev->descriptor.bNumConfigurations = cfgno;
break;
} else if (result < 4) {
dev_err(ddev, "config index %d descriptor too short "
"(expected %i, got %i)\n", cfgno,
USB_DT_CONFIG_SIZE, result);
result = -EINVAL;
goto err;
}
length = max((int) le16_to_cpu(desc->wTotalLength),
USB_DT_CONFIG_SIZE);
/* Now that we know the length, get the whole thing */
bigbuffer = kmalloc(length, GFP_KERNEL);
if (!bigbuffer) {
result = -ENOMEM;
goto err;
}
result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno,
bigbuffer, length);
if (result < 0) {
dev_err(ddev, "unable to read config index %d "
"descriptor/%s\n", cfgno, "all");
kfree(bigbuffer);
goto err;
}
if (result < length) {
dev_warn(ddev, "config index %d descriptor too short "
"(expected %i, got %i)\n", cfgno, length, result);
length = result;
}
dev->rawdescriptors[cfgno] = bigbuffer;
result = usb_parse_configuration(&dev->dev, cfgno,
&dev->config[cfgno], bigbuffer, length);
if (result < 0) {
++cfgno;
goto err;
}
}
result = 0;
err:
kfree(buffer);
out_not_authorized:
dev->descriptor.bNumConfigurations = cfgno;
err2:
if (result == -ENOMEM)
dev_err(ddev, "out of memory\n");
return result;
}
