xref: /third_party/FreeBSD/sys/dev/usb/usb_util.c

/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2008-2022 Hans Petter Selasky
 *
 * 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 "implementation/global_implementation.h"

/*------------------------------------------------------------------------*
 *	device_set_usb_desc
 *
 * This function can be called at probe or attach to set the USB
 * device supplied textual description for the given device.
 *------------------------------------------------------------------------*/
void
device_set_usb_desc(device_t dev)
{
	struct usb_attach_arg *uaa;
	struct usb_device *udev;
	struct usb_interface *iface;
	char *temp_p;
	usb_error_t err;
	uint8_t do_unlock;

	if (dev == NULL) {
		/* should not happen */
		return;
	}
	uaa = device_get_ivars(dev);
	if (uaa == NULL) {
		/* can happen if called at the wrong time */
		return;
	}
	udev = uaa->device;
	iface = uaa->iface;

	if ((iface == NULL) ||
	    (iface->idesc == NULL) ||
	    (iface->idesc->iInterface == 0)) {
		err = USB_ERR_INVAL;
	} else {
		err = USB_ERR_NORMAL_COMPLETION;
	}

	/* Protect scratch area */
	do_unlock = usbd_ctrl_lock(udev);

	temp_p = (char *)udev->scratch.data;

	if (err == 0) {
		/* try to get the interface string ! */
		err = usbd_req_get_string_any(udev, NULL, temp_p,
		    sizeof(udev->scratch.data),
		    iface->idesc->iInterface);
	}
	if (err != 0) {
		/* use default description */
		usb_devinfo(udev, temp_p,
		    sizeof(udev->scratch.data));
	}

	if (do_unlock)
		usbd_ctrl_unlock(udev);

	device_set_desc_copy(dev, temp_p);
	device_printf(dev, "<%s> on %s\n", temp_p,
	    device_get_nameunit(udev->bus->bdev));
}

/*------------------------------------------------------------------------*
 *	 usb_pause_mtx - factored out code
 *
 * This function will delay the code by the passed number of system
 * ticks. The passed mutex "mtx" will be dropped while waiting, if
 * "mtx" is different from NULL.
 *------------------------------------------------------------------------*/
void
usb_pause_mtx(struct mtx *mtx, int timo)
{
	if (mtx != NULL)
		mtx_unlock(mtx);

	/*
	 * Add one tick to the timeout so that we don't return too
	 * early! Note that pause() will assert that the passed
	 * timeout is positive and non-zero!
	 */
	pause("USBWAIT", (uint32_t)(timo + 1));

	if (mtx != NULL)
		mtx_lock(mtx);
}

/*------------------------------------------------------------------------*
 *	usb_printbcd
 *
 * This function will print the version number "bcd" to the string
 * pointed to by "p" having a maximum length of "p_len" bytes
 * including the terminating zero.
 *------------------------------------------------------------------------*/
void
usb_printbcd(char *p, uint16_t p_len, uint16_t bcd)
{
	if (snprintf_s(p, p_len, p_len - 1, "%x.%02x", bcd >> 8, bcd & 0xff)) {
		/* ignore any errors */
	}
}

/*------------------------------------------------------------------------*
 *	usb_trim_spaces
 *
 * This function removes spaces at the beginning and the end of the string
 * pointed to by the "p" argument.
 *------------------------------------------------------------------------*/
void
usb_trim_spaces(char *p)
{
	char *q;
	char *e;

	if (p == NULL)
		return;
	q = e = p;
	while (*q == ' ')		/* skip leading spaces */
		q++;
	while ((*p = *q++))		/* copy string */
		if (*p++ != ' ')	/* remember last non-space */
			e = p;
	*e = 0;				/* kill trailing spaces */
}

/*------------------------------------------------------------------------*
 *	usb_make_str_desc - convert an ASCII string into a UNICODE string
 *------------------------------------------------------------------------*/
uint8_t
usb_make_str_desc(void *ptr, uint16_t max_len, const char *s)
{
	struct usb_string_descriptor *p = ptr;
	uint8_t totlen;
	int j;

	if (max_len < 2) {
		/* invalid length */
		return (0);
	}
	max_len = ((max_len / 2) - 1);

	j = strlen(s);

	if (j < 0) {
		j = 0;
	}
	if (j > 126) {
		j = 126;
	}
	if (max_len > j) {
		max_len = j;
	}
	totlen = (max_len + 1) * 2;

	p->bLength = totlen;
	p->bDescriptorType = UDESC_STRING;

	while (max_len--) {
		USETW2(p->bString[max_len], 0, s[max_len]);
	}
	return (totlen);
}

/*------------------------------------------------------------------------*
 *	usb_check_request - prevent damaging USB requests
 *
 * Return values:
 * 0: Access allowed
 * Else: No access
 *------------------------------------------------------------------------*/
#if USB_HAVE_UGEN
int
usb_check_request(struct usb_device *udev, struct usb_device_request *req)
{
	struct usb_endpoint *ep;
	int error;

	/*
	 * Avoid requests that would damage the bus integrity:
	 */
	if (((req->bmRequestType == UT_WRITE_DEVICE) &&
	    (req->bRequest == UR_SET_ADDRESS)) ||
	    ((req->bmRequestType == UT_WRITE_DEVICE) &&
	    (req->bRequest == UR_SET_CONFIG)) ||
	    ((req->bmRequestType == UT_WRITE_INTERFACE) &&
	    (req->bRequest == UR_SET_INTERFACE))) {
		/*
		 * These requests can be useful for testing USB drivers.
		 */
		error = priv_check(curthread, PRIV_DRIVER);
		if (error)
			return (error);
	}

	/*
	 * Special case - handle clearing of stall
	 */
	if (req->bmRequestType == UT_WRITE_ENDPOINT) {
		ep = usbd_get_ep_by_addr(udev, req->wIndex[0]);
		if (ep == NULL)
			return (EINVAL);
		if ((req->bRequest == UR_CLEAR_FEATURE) &&
		    (UGETW(req->wValue) == UF_ENDPOINT_HALT))
			usbd_clear_data_toggle(udev, ep);
	}

	/* TODO: add more checks to verify the interface index */

	return (0);
}
#endif