xref: /freebsd/sys/dev/usb/usb_util.c (revision 19fae0f66023a97a9b464b3beeeabb2081f575b3)
1 /* $FreeBSD$ */
2 /*-
3  * SPDX-License-Identifier: BSD-2-Clause
4  *
5  * Copyright (c) 2008-2022 Hans Petter Selasky
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #ifdef USB_GLOBAL_INCLUDE_FILE
30 #include USB_GLOBAL_INCLUDE_FILE
31 #else
32 #include <sys/stdint.h>
33 #include <sys/stddef.h>
34 #include <sys/param.h>
35 #include <sys/queue.h>
36 #include <sys/types.h>
37 #include <sys/systm.h>
38 #include <sys/kernel.h>
39 #include <sys/bus.h>
40 #include <sys/module.h>
41 #include <sys/lock.h>
42 #include <sys/mutex.h>
43 #include <sys/condvar.h>
44 #include <sys/sysctl.h>
45 #include <sys/sx.h>
46 #include <sys/unistd.h>
47 #include <sys/callout.h>
48 #include <sys/malloc.h>
49 #include <sys/priv.h>
50 
51 #include <dev/usb/usb.h>
52 #include <dev/usb/usbdi.h>
53 #include <dev/usb/usbdi_util.h>
54 
55 #include <dev/usb/usb_core.h>
56 #include <dev/usb/usb_util.h>
57 #include <dev/usb/usb_process.h>
58 #include <dev/usb/usb_device.h>
59 #include <dev/usb/usb_request.h>
60 #include <dev/usb/usb_busdma.h>
61 
62 #include <dev/usb/usb_controller.h>
63 #include <dev/usb/usb_bus.h>
64 #endif			/* USB_GLOBAL_INCLUDE_FILE */
65 
66 /*------------------------------------------------------------------------*
67  *	device_set_usb_desc
68  *
69  * This function can be called at probe or attach to set the USB
70  * device supplied textual description for the given device.
71  *------------------------------------------------------------------------*/
72 void
73 device_set_usb_desc(device_t dev)
74 {
75 	struct usb_attach_arg *uaa;
76 	struct usb_device *udev;
77 	struct usb_interface *iface;
78 	char *temp_p;
79 	usb_error_t err;
80 	uint8_t do_unlock;
81 
82 	if (dev == NULL) {
83 		/* should not happen */
84 		return;
85 	}
86 	uaa = device_get_ivars(dev);
87 	if (uaa == NULL) {
88 		/* can happen if called at the wrong time */
89 		return;
90 	}
91 	udev = uaa->device;
92 	iface = uaa->iface;
93 
94 	if ((iface == NULL) ||
95 	    (iface->idesc == NULL) ||
96 	    (iface->idesc->iInterface == 0)) {
97 		err = USB_ERR_INVAL;
98 	} else {
99 		err = 0;
100 	}
101 
102 	/* Protect scratch area */
103 	do_unlock = usbd_ctrl_lock(udev);
104 
105 	temp_p = (char *)udev->scratch.data;
106 
107 	if (err == 0) {
108 		/* try to get the interface string ! */
109 		err = usbd_req_get_string_any(udev, NULL, temp_p,
110 		    sizeof(udev->scratch.data),
111 		    iface->idesc->iInterface);
112 	}
113 	if (err != 0) {
114 		/* use default description */
115 		usb_devinfo(udev, temp_p,
116 		    sizeof(udev->scratch.data));
117 	}
118 
119 	if (do_unlock)
120 		usbd_ctrl_unlock(udev);
121 
122 	device_set_desc_copy(dev, temp_p);
123 	device_printf(dev, "<%s> on %s\n", temp_p,
124 	    device_get_nameunit(udev->bus->bdev));
125 }
126 
127 /*------------------------------------------------------------------------*
128  *	 usb_pause_mtx - factored out code
129  *
130  * This function will delay the code by the passed number of system
131  * ticks. The passed mutex "mtx" will be dropped while waiting, if
132  * "mtx" is different from NULL.
133  *------------------------------------------------------------------------*/
134 void
135 usb_pause_mtx(struct mtx *mtx, int timo)
136 {
137 	if (mtx != NULL)
138 		mtx_unlock(mtx);
139 
140 	/*
141 	 * Add one tick to the timeout so that we don't return too
142 	 * early! Note that pause() will assert that the passed
143 	 * timeout is positive and non-zero!
144 	 */
145 	pause("USBWAIT", timo + 1);
146 
147 	if (mtx != NULL)
148 		mtx_lock(mtx);
149 }
150 
151 /*------------------------------------------------------------------------*
152  *	usb_printbcd
153  *
154  * This function will print the version number "bcd" to the string
155  * pointed to by "p" having a maximum length of "p_len" bytes
156  * including the terminating zero.
157  *------------------------------------------------------------------------*/
158 void
159 usb_printbcd(char *p, uint16_t p_len, uint16_t bcd)
160 {
161 	if (snprintf(p, p_len, "%x.%02x", bcd >> 8, bcd & 0xff)) {
162 		/* ignore any errors */
163 	}
164 }
165 
166 /*------------------------------------------------------------------------*
167  *	usb_trim_spaces
168  *
169  * This function removes spaces at the beginning and the end of the string
170  * pointed to by the "p" argument.
171  *------------------------------------------------------------------------*/
172 void
173 usb_trim_spaces(char *p)
174 {
175 	char *q;
176 	char *e;
177 
178 	if (p == NULL)
179 		return;
180 	q = e = p;
181 	while (*q == ' ')		/* skip leading spaces */
182 		q++;
183 	while ((*p = *q++))		/* copy string */
184 		if (*p++ != ' ')	/* remember last non-space */
185 			e = p;
186 	*e = 0;				/* kill trailing spaces */
187 }
188 
189 /*------------------------------------------------------------------------*
190  *	usb_make_str_desc - convert an ASCII string into a UNICODE string
191  *------------------------------------------------------------------------*/
192 uint8_t
193 usb_make_str_desc(void *ptr, uint16_t max_len, const char *s)
194 {
195 	struct usb_string_descriptor *p = ptr;
196 	uint8_t totlen;
197 	int j;
198 
199 	if (max_len < 2) {
200 		/* invalid length */
201 		return (0);
202 	}
203 	max_len = ((max_len / 2) - 1);
204 
205 	j = strlen(s);
206 
207 	if (j < 0) {
208 		j = 0;
209 	}
210 	if (j > 126) {
211 		j = 126;
212 	}
213 	if (max_len > j) {
214 		max_len = j;
215 	}
216 	totlen = (max_len + 1) * 2;
217 
218 	p->bLength = totlen;
219 	p->bDescriptorType = UDESC_STRING;
220 
221 	while (max_len--) {
222 		USETW2(p->bString[max_len], 0, s[max_len]);
223 	}
224 	return (totlen);
225 }
226 
227 /*------------------------------------------------------------------------*
228  *	usb_check_request - prevent damaging USB requests
229  *
230  * Return values:
231  * 0: Access allowed
232  * Else: No access
233  *------------------------------------------------------------------------*/
234 #if USB_HAVE_UGEN
235 int
236 usb_check_request(struct usb_device *udev, struct usb_device_request *req)
237 {
238 	struct usb_endpoint *ep;
239 	int error;
240 
241 	/*
242 	 * Avoid requests that would damage the bus integrity:
243 	 */
244 	if (((req->bmRequestType == UT_WRITE_DEVICE) &&
245 	    (req->bRequest == UR_SET_ADDRESS)) ||
246 	    ((req->bmRequestType == UT_WRITE_DEVICE) &&
247 	    (req->bRequest == UR_SET_CONFIG)) ||
248 	    ((req->bmRequestType == UT_WRITE_INTERFACE) &&
249 	    (req->bRequest == UR_SET_INTERFACE))) {
250 		/*
251 		 * These requests can be useful for testing USB drivers.
252 		 */
253 		error = priv_check(curthread, PRIV_DRIVER);
254 		if (error)
255 			return (error);
256 	}
257 
258 	/*
259 	 * Special case - handle clearing of stall
260 	 */
261 	if (req->bmRequestType == UT_WRITE_ENDPOINT) {
262 		ep = usbd_get_ep_by_addr(udev, req->wIndex[0]);
263 		if (ep == NULL)
264 			return (EINVAL);
265 		if ((req->bRequest == UR_CLEAR_FEATURE) &&
266 		    (UGETW(req->wValue) == UF_ENDPOINT_HALT))
267 			usbd_clear_data_toggle(udev, ep);
268 	}
269 
270 	/* TODO: add more checks to verify the interface index */
271 
272 	return (0);
273 }
274 #endif
275