linux_usbfs.c

最新的libusb库

	if (*config == -1)
		*config = 0;

	return 0;
}

static int op_set_configuration(struct libusb_device_handle *handle, int config)
{
	struct linux_device_priv *priv = __device_priv(handle->dev);
	int fd = __device_handle_priv(handle)->fd;
	int r = ioctl(fd, IOCTL_USBFS_SETCONFIG, &config);
	if (r) {
		if (errno == EINVAL)
			return LIBUSB_ERROR_NOT_FOUND;
		else if (errno == EBUSY)
			return LIBUSB_ERROR_BUSY;
		else if (errno == ENODEV)
			return LIBUSB_ERROR_NO_DEVICE;

		usbi_err(HANDLE_CTX(handle), "failed, error %d errno %d", r, errno);
		return LIBUSB_ERROR_OTHER;
	}

	if (!sysfs_has_descriptors) {
		/* update our cached active config descriptor */
		if (config == -1) {
			if (priv->config_descriptor) {
				free(priv->config_descriptor);
				priv->config_descriptor = NULL;
			}
		} else {
			r = cache_active_config(handle->dev, fd, config);
			if (r < 0)
				usbi_warn(HANDLE_CTX(handle),
					"failed to update cached config descriptor, error %d", r);
		}
	}

	return 0;
}

static int op_claim_interface(struct libusb_device_handle *handle, int iface)
{
	int fd = __device_handle_priv(handle)->fd;
	int r = ioctl(fd, IOCTL_USBFS_CLAIMINTF, &iface);
	if (r) {
		if (errno == ENOENT)
			return LIBUSB_ERROR_NOT_FOUND;
		else if (errno == EBUSY)
			return LIBUSB_ERROR_BUSY;
		else if (errno == ENODEV)
			return LIBUSB_ERROR_NO_DEVICE;

		usbi_err(HANDLE_CTX(handle),
			"claim interface failed, error %d errno %d", r, errno);
		return LIBUSB_ERROR_OTHER;
	}
	return 0;
}

static int op_release_interface(struct libusb_device_handle *handle, int iface)
{
	int fd = __device_handle_priv(handle)->fd;
	int r = ioctl(fd, IOCTL_USBFS_RELEASEINTF, &iface);
	if (r) {
		if (errno == ENODEV)
			return LIBUSB_ERROR_NO_DEVICE;

		usbi_err(HANDLE_CTX(handle),
			"release interface failed, error %d errno %d", r, errno);
		return LIBUSB_ERROR_OTHER;
	}
	return 0;
}

static int op_set_interface(struct libusb_device_handle *handle, int iface,
	int altsetting)
{
	int fd = __device_handle_priv(handle)->fd;
	struct usbfs_setinterface setintf;
	int r;

	setintf.interface = iface;
	setintf.altsetting = altsetting;
	r = ioctl(fd, IOCTL_USBFS_SETINTF, &setintf);
	if (r) {
		if (errno == EINVAL)
			return LIBUSB_ERROR_NOT_FOUND;
		else if (errno == ENODEV)
			return LIBUSB_ERROR_NO_DEVICE;

		usbi_err(HANDLE_CTX(handle),
			"setintf failed error %d errno %d", r, errno);
		return LIBUSB_ERROR_OTHER;
	}

	return 0;
}

static int op_clear_halt(struct libusb_device_handle *handle,
	unsigned char endpoint)
{
	int fd = __device_handle_priv(handle)->fd;
	unsigned int _endpoint = endpoint;
	int r = ioctl(fd, IOCTL_USBFS_CLEAR_HALT, &_endpoint);
	if (r) {
		if (errno == ENOENT)
			return LIBUSB_ERROR_NOT_FOUND;
		else if (errno == ENODEV)
			return LIBUSB_ERROR_NO_DEVICE;

		usbi_err(HANDLE_CTX(handle),
			"clear_halt failed error %d errno %d", r, errno);
		return LIBUSB_ERROR_OTHER;
	}

	return 0;
}

static int op_reset_device(struct libusb_device_handle *handle)
{
	int fd = __device_handle_priv(handle)->fd;
	int r = ioctl(fd, IOCTL_USBFS_RESET, NULL);
	if (r) {
		if (errno == ENODEV)
			return LIBUSB_ERROR_NOT_FOUND;

		usbi_err(HANDLE_CTX(handle),
			"reset failed error %d errno %d", r, errno);
		return LIBUSB_ERROR_OTHER;
	}

	return 0;
}

static int op_kernel_driver_active(struct libusb_device_handle *handle,
	int interface)
{
	int fd = __device_handle_priv(handle)->fd;
	struct usbfs_getdriver getdrv;
	int r;

	getdrv.interface = interface;
	r = ioctl(fd, IOCTL_USBFS_GETDRIVER, &getdrv);
	if (r) {
		if (errno == ENODATA)
			return 0;
		else if (errno == ENODEV)
			return LIBUSB_ERROR_NO_DEVICE;

		usbi_err(HANDLE_CTX(handle),
			"get driver failed error %d errno %d", r, errno);
		return LIBUSB_ERROR_OTHER;
	}

	return 1;
}

static int op_detach_kernel_driver(struct libusb_device_handle *handle,
	int interface)
{
	int fd = __device_handle_priv(handle)->fd;
	struct usbfs_ioctl command;
	int r;

	command.ifno = interface;
	command.ioctl_code = IOCTL_USBFS_DISCONNECT;
	command.data = NULL;

	r = ioctl(fd, IOCTL_USBFS_IOCTL, &command);
	if (r) {
		if (errno == ENODATA)
			return LIBUSB_ERROR_NOT_FOUND;
		else if (errno == EINVAL)
			return LIBUSB_ERROR_INVALID_PARAM;
		else if (errno == ENODEV)
			return LIBUSB_ERROR_NO_DEVICE;

		usbi_err(HANDLE_CTX(handle),
			"detach failed error %d errno %d", r, errno);
		return LIBUSB_ERROR_OTHER;
	}

	return 0;
}

static void op_destroy_device(struct libusb_device *dev)
{
	struct linux_device_priv *priv = __device_priv(dev);
	if (!sysfs_has_descriptors) {
		if (priv->dev_descriptor)
			free(priv->dev_descriptor);
		if (priv->config_descriptor)
			free(priv->config_descriptor);
	}
	if (priv->sysfs_dir)
		free(priv->sysfs_dir);
}

static void free_iso_urbs(struct linux_transfer_priv *tpriv)
{
	int i;
	for (i = 0; i < tpriv->num_urbs; i++) {
		struct usbfs_urb *urb = tpriv->iso_urbs[i];
		if (!urb)
			break;
		free(urb);
	}

	free(tpriv->iso_urbs);
}

static int submit_bulk_transfer(struct usbi_transfer *itransfer,
	unsigned char urb_type)
{
	struct libusb_transfer *transfer =
		__USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
	struct linux_transfer_priv *tpriv = usbi_transfer_get_os_priv(itransfer);
	struct linux_device_handle_priv *dpriv =
		__device_handle_priv(transfer->dev_handle);
	struct usbfs_urb *urbs;
	int r;
	int i;
	size_t alloc_size;

	/* usbfs places a 16kb limit on bulk URBs. we divide up larger requests
	 * into smaller units to meet such restriction, then fire off all the
	 * units at once. it would be simpler if we just fired one unit at a time,
	 * but there is a big performance gain through doing it this way. */
	int num_urbs = transfer->length / MAX_BULK_BUFFER_LENGTH;
	int last_urb_partial = 0;

	if ((transfer->length % MAX_BULK_BUFFER_LENGTH) > 0) {
		last_urb_partial = 1;
		num_urbs++;
	}
	usbi_dbg("need %d urbs for new transfer with length %d", num_urbs,
		transfer->length);
	alloc_size = num_urbs * sizeof(struct usbfs_urb);
	urbs = malloc(alloc_size);
	if (!urbs)
		return LIBUSB_ERROR_NO_MEM;
	memset(urbs, 0, alloc_size);
	tpriv->urbs = urbs;
	tpriv->num_urbs = num_urbs;
	tpriv->awaiting_discard = 0;
	tpriv->awaiting_reap = 0;
	tpriv->reap_action = NORMAL;

	for (i = 0; i < num_urbs; i++) {
		struct usbfs_urb *urb = &urbs[i];
		urb->usercontext = itransfer;
		urb->type = urb_type;
		urb->endpoint = transfer->endpoint;
		urb->buffer = transfer->buffer + (i * MAX_BULK_BUFFER_LENGTH);
		if (i == num_urbs - 1 && last_urb_partial)
			urb->buffer_length = transfer->length % MAX_BULK_BUFFER_LENGTH;
		else
			urb->buffer_length = MAX_BULK_BUFFER_LENGTH;

		r = ioctl(dpriv->fd, IOCTL_USBFS_SUBMITURB, urb);
		if (r < 0) {
			int j;

			if (errno == ENODEV) {
				r = LIBUSB_ERROR_NO_DEVICE;
			} else {
				usbi_err(TRANSFER_CTX(transfer),
					"submiturb failed error %d errno=%d", r, errno);
				r = LIBUSB_ERROR_IO;
			}
	
			/* if the first URB submission fails, we can simply free up and
			 * return failure immediately. */
			if (i == 0) {
				usbi_dbg("first URB failed, easy peasy");
				free(urbs);
				return r;
			}

			/* if it's not the first URB that failed, the situation is a bit
			 * tricky. we must discard all previous URBs. there are
			 * complications:
			 *  - discarding is asynchronous - discarded urbs will be reaped
			 *    later. the user must not have freed the transfer when the
			 *    discarded URBs are reaped, otherwise libusb will be using
			 *    freed memory.
			 *  - the earlier URBs may have completed successfully and we do
			 *    not want to throw away any data.
			 * so, in this case we discard all the previous URBs BUT we report
			 * that the transfer was submitted successfully. then later when
			 * the final discard completes we can report error to the user.
			 */
			tpriv->reap_action = SUBMIT_FAILED;
			for (j = 0; j < i; j++) {
				int tmp = ioctl(dpriv->fd, IOCTL_USBFS_DISCARDURB, &urbs[j]);
				if (tmp == 0)
					tpriv->awaiting_discard++;
				else if (errno == EINVAL)
					tpriv->awaiting_reap++;
				else
					usbi_warn(TRANSFER_CTX(transfer),
						"unrecognised discard return %d", tmp);
			}

			usbi_dbg("reporting successful submission but waiting for %d "
				"discards and %d reaps before reporting error",
				tpriv->awaiting_discard, tpriv->awaiting_reap);
			return 0;
		}
	}

	return 0;
}

static int submit_iso_transfer(struct usbi_transfer *itransfer)
{
	struct libusb_transfer *transfer =
		__USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
	struct linux_transfer_priv *tpriv = usbi_transfer_get_os_priv(itransfer);
	struct linux_device_handle_priv *dpriv =
		__device_handle_priv(transfer->dev_handle);
	struct usbfs_urb **urbs;
	size_t alloc_size;
	int num_packets = transfer->num_iso_packets;
	int i;
	int this_urb_len = 0;
	int num_urbs = 1;
	int packet_offset = 0;
	unsigned int packet_len;
	unsigned char *urb_buffer = transfer->buffer;

	/* usbfs places a 32kb limit on iso URBs. we divide up larger requests
	 * into smaller units to meet such restriction, then fire off all the
	 * units at once. it would be simpler if we just fired one unit at a time,
	 * but there is a big performance gain through doing it this way. */

	/* calculate how many URBs we need */
	for (i = 0; i < num_packets; i++) {
		int space_remaining = MAX_ISO_BUFFER_LENGTH - this_urb_len;
		packet_len = transfer->iso_packet_desc[i].length;

		if (packet_len > space_remaining) {
			num_urbs++;
			this_urb_len = packet_len;
		} else {
			this_urb_len += packet_len;
		}
	}
	usbi_dbg("need %d 32k URBs for transfer", num_urbs);

	alloc_size = num_urbs * sizeof(*urbs);
	urbs = malloc(alloc_size);
	if (!urbs)
		return LIBUSB_ERROR_NO_MEM;
	memset(urbs, 0, alloc_size);

	tpriv->iso_urbs = urbs;
	tpriv->num_urbs = num_urbs;
	tpriv->awaiting_discard = 0;
	tpriv->awaiting_reap = 0;
	tpriv->reap_action = NORMAL;
	tpriv->iso_packet_offset = 0;

	/* allocate + initialize each URB with the correct number of packets */
	for (i = 0; i < num_urbs; i++) {
		struct usbfs_urb *urb;
		int space_remaining_in_urb = MAX_ISO_BUFFER_LENGTH;
		int urb_packet_offset = 0;
		unsigned char *urb_buffer_orig = urb_buffer;
		int j;
		int k;

		/* swallow up all the packets we can fit into this URB */
		while (packet_offset < transfer->num_iso_packets) {
			packet_len = transfer->iso_packet_desc[packet_offset].length;
			if (packet_len <= space_remaining_in_urb) {
				/* throw it in */
				urb_packet_offset++;
				packet_offset++;
				space_remaining_in_urb -= packet_len;
				urb_buffer += packet_len;
			} else {
				/* it can't fit, save it for the next URB */
				break;
			}
		}

		alloc_size = sizeof(*urb)
			+ (urb_packet_offset * sizeof(struct usbfs_iso_packet_desc));
		urb = malloc(alloc_size);
		if (!urb) {
			free_iso_urbs(tpriv);
			return LIBUSB_ERROR_NO_MEM;
		}
		memset(urb, 0, alloc_size);
		urbs[i] = urb;

		/* populate packet lengths */
		for (j = 0, k = packet_offset - urb_packet_offset;
				k < packet_offset; k++, j++) {
			packet_len = transfer->iso_packet_desc[k].length;
			urb->iso_frame_desc[j].length = packet_len;
		}

		urb->usercontext = itransfer;
		urb->type = USBFS_URB_TYPE_ISO;
		/* FIXME: interface for non-ASAP data? */
		urb->flags = USBFS_URB_ISO_ASAP;
		urb->endpoint = transfer->endpoint;
		urb->number_of_packets = urb_packet_offset;
		urb->buffer = urb_buffer_orig;
	}

	/* submit URBs */
	for (i = 0; i < num_urbs; i++) {
		int r = ioctl(dpriv->fd, IOCTL_USBFS_SUBMITURB, urbs[i]);
		if (r < 0) {
			int j;

			if (errno == ENODEV) {
				r = LIBUSB_ERROR_NO_DEVICE;
			} else {
				usbi_err(TRANSFER_CTX(transfer),
					"submiturb failed error %d errno=%d", r, errno);
				r = LIBUSB_ERROR_IO;
			}

			/* if the first URB submission fails, we can simply free up and
			 * return failure immediately. */
			if (i == 0) {
				usbi_dbg("first URB failed, easy peasy");
				free_iso_urbs(tpriv);
				return r;
			}

			/* if it's not the first URB that failed, the situation is a bit
			 * tricky. we must discard all previous URBs. there are
			 * complications:
			 *  - discarding is asynchronous - discarded urbs will be reaped
			 *    later. the user must not have freed the transfer when the
			 *    discarded URBs are reaped, otherwise libusb will be using
			 *    freed memory.
			 *  - the earlier URBs may have completed successfully and we do
			 *    not want to throw away any data.
			 * so, in this case we discard all the previous URBs BUT we report
			 * that the transfer was submitted successfully. then later when
			 * the final discard completes we can report error to the user.
			 */
			tpriv->reap_action = SUBMIT_FAILED;
			for (j = 0; j < i; j++) {
				int tmp = ioctl(dpriv->fd, IOCTL_USBFS_DISCARDURB, urbs[j]);
				if (tmp == 0)
					tpriv->awaiting_discard++;
				else if (errno == EINVAL)
					tpriv->awaiting_reap++;
				else
					usbi_warn(TRANSFER_CTX(transfer),
						"unrecognised discard return %d", tmp);
			}

			usbi_dbg("reporting successful submission but waiting for %d "
				"discards and %d reaps before reporting error",
				tpriv->awaiting_discard, tpriv->awaiting_reap);
			return 0;
		}
	}

	return 0;
}

static int submit_control_transfer(struct usbi_transfer *itransfer)
{
	struct linux_transfer_priv *tpriv = usbi_transfer_get_os_priv(itransfer);
	struct libusb_transfer *transfer =
		__USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
	struct linux_device_handle_priv *dpriv =
		__device_handle_priv(transfer->dev_handle);
	struct usbfs_urb *urb;
	int r;

	if (transfer->length - LIBUSB_CONTROL_SETUP_SIZE > MAX_CTRL_BUFFER_LENGTH)
		return LIBUSB_ERROR_INVALID_PARAM;

	urb = malloc(sizeof(struct usbfs_urb));
	if (!urb)
		return LIBUSB_ERROR_NO_MEM;
	memset(urb, 0, sizeof(struct usbfs_urb));
	tpriv->urbs = urb;
	tpriv->reap_action = NORMAL;

	urb->usercontext = itransfer;
	urb->type = USBFS_URB_TYPE_CONTROL;
	urb->endpoint = transfer->endpoint;
	urb->buffer = transfer->buffer;
	urb->buffer_length = transfer->length;

	r = ioctl(dpriv->fd, IOCTL_USBFS_SUBMITURB, urb);
	if (r < 0) {
		free(urb);
		if (errno == ENODEV)
			return LIBUSB_ERROR_NO_DEVICE;