config.c

ReactOs中的USB驱动

#if 0
#include <linux/usb.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <asm/byteorder.h>
#else
#include "../miniport/usb_wrapper.h"
#endif

#define USB_MAXALTSETTING		128	/* Hard limit */
#define USB_MAXENDPOINTS		30	/* Hard limit */

/* these maximums are arbitrary */
#define USB_MAXCONFIG			8
#define USB_ALTSETTINGALLOC		4
#define USB_MAXINTERFACES		32

static int usb_parse_endpoint(struct usb_host_endpoint *endpoint, char *buffer, int size)
{
	struct usb_descriptor_header *header;
	char *begin;
	int parsed = 0, len, numskipped;

	header = (struct usb_descriptor_header *)buffer;

	/* Everything should be fine being passed into here, but we sanity */
	/*  check JIC */
	if (header->bLength > size) {
		err("ran out of descriptors parsing");
		return -1;
	}
		
	if (header->bDescriptorType != USB_DT_ENDPOINT) {
		warn("unexpected descriptor 0x%X, expecting endpoint, 0x%X",
			header->bDescriptorType, USB_DT_ENDPOINT);
		return parsed;
	}

	if (header->bLength == USB_DT_ENDPOINT_AUDIO_SIZE)
		memcpy(&endpoint->desc, buffer, USB_DT_ENDPOINT_AUDIO_SIZE);
	else
		memcpy(&endpoint->desc, buffer, USB_DT_ENDPOINT_SIZE);
	
	le16_to_cpus(&endpoint->desc.wMaxPacketSize);

	buffer += header->bLength;
	size -= header->bLength;
	parsed += header->bLength;

	/* Skip over the rest of the Class Specific or Vendor Specific */
	/*  descriptors */
	begin = buffer;
	numskipped = 0;
	while (size >= sizeof(struct usb_descriptor_header)) {
		header = (struct usb_descriptor_header *)buffer;

		if (header->bLength < 2) {
			err("invalid descriptor length of %d", header->bLength);
			return -1;
		}

		/* If we find another "proper" descriptor then we're done  */
		if ((header->bDescriptorType == USB_DT_ENDPOINT) ||
		    (header->bDescriptorType == USB_DT_INTERFACE) ||
		    (header->bDescriptorType == USB_DT_CONFIG) ||
		    (header->bDescriptorType == USB_DT_DEVICE))
			break;

		dbg("skipping descriptor 0x%X",
			header->bDescriptorType);
		numskipped++;

		buffer += header->bLength;
		size -= header->bLength;
		parsed += header->bLength;
	}
	if (numskipped)
		dbg("skipped %d class/vendor specific endpoint descriptors", numskipped);

	/* Copy any unknown descriptors into a storage area for drivers */
	/*  to later parse */
	len = (int)(buffer - begin);
	if (!len) {
		endpoint->extra = NULL;
		endpoint->extralen = 0;
		return parsed;
	}

	endpoint->extra = kmalloc(len, GFP_KERNEL);

	if (!endpoint->extra) {
		err("couldn't allocate memory for endpoint extra descriptors");
		endpoint->extralen = 0;
		return parsed;
	}

	memcpy(endpoint->extra, begin, len);
	endpoint->extralen = len;

	return parsed;
}

static int usb_parse_interface(struct usb_interface *interface, char *buffer, int size)
{
	int i, len, numskipped, retval, parsed = 0;
	struct usb_descriptor_header *header;
	struct usb_host_interface *ifp;
	char *begin;

	interface->act_altsetting = 0;
	interface->num_altsetting = 0;
	interface->max_altsetting = USB_ALTSETTINGALLOC;
	device_initialize(&interface->dev);

	interface->altsetting = kmalloc(sizeof(*interface->altsetting) * interface->max_altsetting,
					GFP_KERNEL);
	
	if (!interface->altsetting) {
		err("couldn't kmalloc interface->altsetting");
		return -1;
	}

	while (size > 0) {
		struct usb_interface_descriptor	*d;
	
		if (interface->num_altsetting >= interface->max_altsetting) {
			struct usb_host_interface *ptr;
			int oldmas;

			oldmas = interface->max_altsetting;
			interface->max_altsetting += USB_ALTSETTINGALLOC;
			if (interface->max_altsetting > USB_MAXALTSETTING) {
				warn("too many alternate settings (incr %d max %d)\n",
					USB_ALTSETTINGALLOC, USB_MAXALTSETTING);
				return -1;
			}

			ptr = kmalloc(sizeof(*ptr) * interface->max_altsetting, GFP_KERNEL);
			if (ptr == NULL) {
				err("couldn't kmalloc interface->altsetting");
				return -1;
			}
			memcpy(ptr, interface->altsetting, sizeof(*interface->altsetting) * oldmas);
			kfree(interface->altsetting);
			interface->altsetting = ptr;
		}

		ifp = interface->altsetting + interface->num_altsetting;
		ifp->endpoint = NULL;
		ifp->extra = NULL;
		ifp->extralen = 0;
		interface->num_altsetting++;

		memcpy(ifp, buffer, USB_DT_INTERFACE_SIZE);

		/* Skip over the interface */
		buffer += ifp->desc.bLength;
		parsed += ifp->desc.bLength;
		size -= ifp->desc.bLength;

		begin = buffer;
		numskipped = 0;

		/* Skip over any interface, class or vendor descriptors */
		while (size >= sizeof(struct usb_descriptor_header)) {
			header = (struct usb_descriptor_header *)buffer;

			if (header->bLength < 2) {
				err("invalid descriptor length of %d", header->bLength);
				return -1;
			}

			/* If we find another "proper" descriptor then we're done  */
			if ((header->bDescriptorType == USB_DT_INTERFACE) ||
			    (header->bDescriptorType == USB_DT_ENDPOINT) ||
			    (header->bDescriptorType == USB_DT_CONFIG) ||
			    (header->bDescriptorType == USB_DT_DEVICE))
				break;

			numskipped++;

			buffer += header->bLength;
			parsed += header->bLength;
			size -= header->bLength;
		}

		if (numskipped)
			dbg("skipped %d class/vendor specific interface descriptors", numskipped);

		/* Copy any unknown descriptors into a storage area for */
		/*  drivers to later parse */
		len = (int)(buffer - begin);
		if (len) {
			ifp->extra = kmalloc(len, GFP_KERNEL);

			if (!ifp->extra) {
				err("couldn't allocate memory for interface extra descriptors");
				ifp->extralen = 0;
				return -1;
			}
			memcpy(ifp->extra, begin, len);
			ifp->extralen = len;
		}

		/* Did we hit an unexpected descriptor? */
		header = (struct usb_descriptor_header *)buffer;
		if ((size >= sizeof(struct usb_descriptor_header)) &&
		    ((header->bDescriptorType == USB_DT_CONFIG) ||
		     (header->bDescriptorType == USB_DT_DEVICE)))
			return parsed;

		if (ifp->desc.bNumEndpoints > USB_MAXENDPOINTS) {
			warn("too many endpoints");
			return -1;
		}

		ifp->endpoint = (struct usb_host_endpoint *)
			kmalloc(ifp->desc.bNumEndpoints *
			sizeof(struct usb_host_endpoint), GFP_KERNEL);
		if (!ifp->endpoint) {
			err("out of memory");
			return -1;	
		}

		memset(ifp->endpoint, 0, ifp->desc.bNumEndpoints *
			sizeof(struct usb_host_endpoint));
	
		for (i = 0; i < ifp->desc.bNumEndpoints; i++) {
			header = (struct usb_descriptor_header *)buffer;

			if (header->bLength > size) {
				err("ran out of descriptors parsing");
				return -1;
			}
		
			retval = usb_parse_endpoint(ifp->endpoint + i, buffer, size);
			if (retval < 0)
				return retval;

			buffer += retval;
			parsed += retval;
			size -= retval;
		}

		/* We check to see if it's an alternate to this one */
		d = (struct usb_interface_descriptor *)buffer;
		if (size < USB_DT_INTERFACE_SIZE
				|| d->bDescriptorType != USB_DT_INTERFACE
				|| !d->bAlternateSetting)
			return parsed;
	}

	return parsed;
}

int usb_parse_configuration(struct usb_host_config *config, char *buffer)
{
	int i, retval, size;
	struct usb_descriptor_header *header;

	memcpy(&config->desc, buffer, USB_DT_CONFIG_SIZE);
	le16_to_cpus(&config->desc.wTotalLength);
	size = config->desc.wTotalLength;

	if (config->desc.bNumInterfaces > USB_MAXINTERFACES) {
		warn("too many interfaces");
		return -1;
	}

	config->interface = (struct usb_interface *)
		kmalloc(config->desc.bNumInterfaces *
		sizeof(struct usb_interface), GFP_KERNEL);
	dbg("kmalloc IF %p, numif %i", config->interface, config->desc.bNumInterfaces);
	if (!config->interface) {
		err("out of memory");
		return -1;	
	}

	memset(config->interface, 0,
	       config->desc.bNumInterfaces * sizeof(struct usb_interface));

	buffer += config->desc.bLength;
	size -= config->desc.bLength;
	
	config->extra = NULL;
	config->extralen = 0;

	for (i = 0; i < config->desc.bNumInterfaces; i++) {
		int numskipped, len;
		char *begin;

		/* Skip over the rest of the Class Specific or Vendor */
		/*  Specific descriptors */
		begin = buffer;
		numskipped = 0;
		while (size >= sizeof(struct usb_descriptor_header)) {
			header = (struct usb_descriptor_header *)buffer;

			if ((header->bLength > size) || (header->bLength < 2)) {
				err("invalid descriptor length of %d", header->bLength);
				return -1;
			}

			/* If we find another "proper" descriptor then we're done  */
			if ((header->bDescriptorType == USB_DT_ENDPOINT) ||
			    (header->bDescriptorType == USB_DT_INTERFACE) ||
			    (header->bDescriptorType == USB_DT_CONFIG) ||
			    (header->bDescriptorType == USB_DT_DEVICE))
				break;

			dbg("skipping descriptor 0x%X", header->bDescriptorType);
			numskipped++;

			buffer += header->bLength;
			size -= header->bLength;
		}
		if (numskipped)
			dbg("skipped %d class/vendor specific endpoint descriptors", numskipped);

		/* Copy any unknown descriptors into a storage area for */
		/*  drivers to later parse */
		len = (int)(buffer - begin);
		if (len) {
			if (config->extralen) {
				warn("extra config descriptor");
			} else {
				config->extra = kmalloc(len, GFP_KERNEL);
				if (!config->extra) {
					err("couldn't allocate memory for config extra descriptors");
					config->extralen = 0;
					return -1;
				}

				memcpy(config->extra, begin, len);
				config->extralen = len;
			}
		}

		retval = usb_parse_interface(config->interface + i, buffer, size);
		if (retval < 0)
			return retval;

		buffer += retval;
		size -= retval;
	}

	return size;
}

// 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, j, k;
	
	if (!dev->config)
		return;

	if (dev->rawdescriptors) {
		for (i = 0; i < dev->descriptor.bNumConfigurations; i++)
			kfree(dev->rawdescriptors[i]);

		kfree(dev->rawdescriptors);
	}

	for (c = 0; c < dev->descriptor.bNumConfigurations; c++) {
		struct usb_host_config *cf = &dev->config[c];

		if (!cf->interface)
			break;

		for (i = 0; i < cf->desc.bNumInterfaces; i++) {
			struct usb_interface *ifp =
				&cf->interface[i];
				
			if (!ifp->altsetting)
				break;

			for (j = 0; j < ifp->num_altsetting; j++) {
				struct usb_host_interface *as =
					&ifp->altsetting[j];
					
				if(as->extra) {
					kfree(as->extra);
				}

				if (!as->endpoint)
					break;
					
				for(k = 0; k < as->desc.bNumEndpoints; k++) {
					if(as->endpoint[k].extra) {
						kfree(as->endpoint[k].extra);
					}
				}	
				kfree(as->endpoint);
			}

			kfree(ifp->altsetting);
		}
		kfree(cf->interface);
	}
	kfree(dev->config);
}


// hub-only!! ... and only in reset path, or usb_new_device()
// (used by real hubs and virtual root hubs)
int usb_get_configuration(struct usb_device *dev)
{
	int result;
	unsigned int cfgno, length;
	char *buffer;
	char *bigbuffer;
 	struct usb_config_descriptor *desc;

	if (dev->descriptor.bNumConfigurations > USB_MAXCONFIG) {
		warn("too many configurations");
		return -EINVAL;
	}

	if (dev->descriptor.bNumConfigurations < 1) {
		warn("not enough configurations");
		return -EINVAL;
	}

	dev->config = (struct usb_host_config *)
		kmalloc(dev->descriptor.bNumConfigurations *
		sizeof(struct usb_host_config), GFP_KERNEL);
	if (!dev->config) {
		err("out of memory");
		return -ENOMEM;	
	}
	memset(dev->config, 0, dev->descriptor.bNumConfigurations *
		sizeof(struct usb_host_config));

	dev->rawdescriptors = (char **)kmalloc(sizeof(char *) *
		dev->descriptor.bNumConfigurations, GFP_KERNEL);
	if (!dev->rawdescriptors) {
		err("out of memory");
		return -ENOMEM;
	}

	buffer = kmalloc(8, GFP_KERNEL);
	if (!buffer) {
		err("unable to allocate memory for configuration descriptors");
		return -ENOMEM;
	}
	desc = (struct usb_config_descriptor *)buffer;

	for (cfgno = 0; cfgno < dev->descriptor.bNumConfigurations; cfgno++) {
		/* We grab the first 8 bytes so we know how long the whole */
		/*  configuration is */
		result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno, buffer, 8);
		if (result < 8) {
                        if (result < 0) {
				err("unable to get descriptor");
                        }
			else {
				err("config descriptor too short (expected %i, got %i)", 8, result);
				result = -EINVAL;
			}
			goto err;
		}

  	  	/* Get the full buffer */
		length = le16_to_cpu(desc->wTotalLength);

		bigbuffer = kmalloc(length, GFP_KERNEL);
		if (!bigbuffer) {
			err("unable to allocate memory for configuration descriptors");
			result = -ENOMEM;
			goto err;
		}

		/* Now that we know the length, get the whole thing */
		result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno, bigbuffer, length);
		if (result < 0) {
			err("couldn't get all of config descriptors");
			kfree(bigbuffer);
			goto err;
		}	
	
		if (result < length) {
			err("config descriptor too short (expected %i, got %i)", length, result);
			result = -EINVAL;
			kfree(bigbuffer);
			goto err;
		}

		dev->rawdescriptors[cfgno] = bigbuffer;

		result = usb_parse_configuration(&dev->config[cfgno], bigbuffer);
		if (result > 0)
			dbg("descriptor data left");
		else if (result < 0) {
			result = -EINVAL;
			goto err;
		}
	}

	kfree(buffer);
	return 0;
err:
	kfree(buffer);
	dev->descriptor.bNumConfigurations = cfgno;
	return result;
}