usb_parse.c revision 331722 
1/* $FreeBSD: stable/11/sys/dev/usb/usb_parse.c 331722 2018-03-29 02:50:57Z eadler $ */
2/*-
3 * Copyright (c) 2008 Hans Petter Selasky. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#ifdef USB_GLOBAL_INCLUDE_FILE
28#include USB_GLOBAL_INCLUDE_FILE
29#else
30#include <sys/stdint.h>
31#include <sys/stddef.h>
32#include <sys/param.h>
33#include <sys/queue.h>
34#include <sys/types.h>
35#include <sys/systm.h>
36#include <sys/kernel.h>
37#include <sys/bus.h>
38#include <sys/module.h>
39#include <sys/lock.h>
40#include <sys/mutex.h>
41#include <sys/condvar.h>
42#include <sys/sysctl.h>
43#include <sys/sx.h>
44#include <sys/unistd.h>
45#include <sys/callout.h>
46#include <sys/malloc.h>
47#include <sys/priv.h>
48
49#include <dev/usb/usb.h>
50#include <dev/usb/usbdi.h>
51#include <dev/usb/usbdi_util.h>
52
53#define	USB_DEBUG_VAR usb_debug
54
55#include <dev/usb/usb_core.h>
56#include <dev/usb/usb_debug.h>
57#endif			/* USB_GLOBAL_INCLUDE_FILE */
58
59/*------------------------------------------------------------------------*
60 *	usb_desc_foreach
61 *
62 * This function is the safe way to iterate across the USB config
63 * descriptor. It contains several checks against invalid
64 * descriptors. If the "desc" argument passed to this function is
65 * "NULL" the first descriptor, if any, will be returned.
66 *
67 * Return values:
68 *   NULL: End of descriptors
69 *   Else: Next descriptor after "desc"
70 *------------------------------------------------------------------------*/
71struct usb_descriptor *
72usb_desc_foreach(struct usb_config_descriptor *cd,
73    struct usb_descriptor *_desc)
74{
75	uint8_t *desc_next;
76	uint8_t *start;
77	uint8_t *end;
78	uint8_t *desc;
79
80	/* be NULL safe */
81	if (cd == NULL)
82		return (NULL);
83
84	/* We assume that the "wTotalLength" has been checked. */
85	start = (uint8_t *)cd;
86	end = start + UGETW(cd->wTotalLength);
87	desc = (uint8_t *)_desc;
88
89	/* Get start of next USB descriptor. */
90	if (desc == NULL)
91		desc = start;
92	else
93		desc = desc + desc[0];
94
95	/* Check that the next USB descriptor is within the range. */
96	if ((desc < start) || (desc >= end))
97		return (NULL);		/* out of range, or EOD */
98
99	/* Check that the second next USB descriptor is within range. */
100	desc_next = desc + desc[0];
101	if ((desc_next < start) || (desc_next > end))
102		return (NULL);		/* out of range */
103
104	/* Check minimum descriptor length. */
105	if (desc[0] < 3)
106		return (NULL);		/* too short descriptor */
107
108	/* Return start of next descriptor. */
109	return ((struct usb_descriptor *)desc);
110}
111
112/*------------------------------------------------------------------------*
113 *	usb_idesc_foreach
114 *
115 * This function will iterate the interface descriptors in the config
116 * descriptor. The parse state structure should be zeroed before
117 * calling this function the first time.
118 *
119 * Return values:
120 *   NULL: End of descriptors
121 *   Else: A valid interface descriptor
122 *------------------------------------------------------------------------*/
123struct usb_interface_descriptor *
124usb_idesc_foreach(struct usb_config_descriptor *cd,
125    struct usb_idesc_parse_state *ps)
126{
127	struct usb_interface_descriptor *id;
128	uint8_t new_iface;
129
130	/* retrieve current descriptor */
131	id = (struct usb_interface_descriptor *)ps->desc;
132	/* default is to start a new interface */
133	new_iface = 1;
134
135	while (1) {
136		id = (struct usb_interface_descriptor *)
137		    usb_desc_foreach(cd, (struct usb_descriptor *)id);
138		if (id == NULL)
139			break;
140		if ((id->bDescriptorType == UDESC_INTERFACE) &&
141		    (id->bLength >= sizeof(*id))) {
142			if (ps->iface_no_last == id->bInterfaceNumber)
143				new_iface = 0;
144			ps->iface_no_last = id->bInterfaceNumber;
145			break;
146		}
147	}
148
149	if (ps->desc == NULL) {
150		/* first time or zero descriptors */
151	} else if (new_iface) {
152		/* new interface */
153		ps->iface_index ++;
154		ps->iface_index_alt = 0;
155	} else {
156		/* new alternate interface */
157		ps->iface_index_alt ++;
158	}
159#if (USB_IFACE_MAX <= 0)
160#error "USB_IFACE_MAX must be defined greater than zero"
161#endif
162	/* check for too many interfaces */
163	if (ps->iface_index >= USB_IFACE_MAX) {
164		DPRINTF("Interface limit reached\n");
165		id = NULL;
166	}
167
168	/* store and return current descriptor */
169	ps->desc = (struct usb_descriptor *)id;
170	return (id);
171}
172
173/*------------------------------------------------------------------------*
174 *	usb_edesc_foreach
175 *
176 * This function will iterate all the endpoint descriptors within an
177 * interface descriptor. Starting value for the "ped" argument should
178 * be a valid interface descriptor.
179 *
180 * Return values:
181 *   NULL: End of descriptors
182 *   Else: A valid endpoint descriptor
183 *------------------------------------------------------------------------*/
184struct usb_endpoint_descriptor *
185usb_edesc_foreach(struct usb_config_descriptor *cd,
186    struct usb_endpoint_descriptor *ped)
187{
188	struct usb_descriptor *desc;
189
190	desc = ((struct usb_descriptor *)ped);
191
192	while ((desc = usb_desc_foreach(cd, desc))) {
193		if (desc->bDescriptorType == UDESC_INTERFACE) {
194			break;
195		}
196		if (desc->bDescriptorType == UDESC_ENDPOINT) {
197			if (desc->bLength < sizeof(*ped)) {
198				/* endpoint descriptor is invalid */
199				break;
200			}
201			return ((struct usb_endpoint_descriptor *)desc);
202		}
203	}
204	return (NULL);
205}
206
207/*------------------------------------------------------------------------*
208 *	usb_ed_comp_foreach
209 *
210 * This function will iterate all the endpoint companion descriptors
211 * within an endpoint descriptor in an interface descriptor. Starting
212 * value for the "ped" argument should be a valid endpoint companion
213 * descriptor.
214 *
215 * Return values:
216 *   NULL: End of descriptors
217 *   Else: A valid endpoint companion descriptor
218 *------------------------------------------------------------------------*/
219struct usb_endpoint_ss_comp_descriptor *
220usb_ed_comp_foreach(struct usb_config_descriptor *cd,
221    struct usb_endpoint_ss_comp_descriptor *ped)
222{
223	struct usb_descriptor *desc;
224
225	desc = ((struct usb_descriptor *)ped);
226
227	while ((desc = usb_desc_foreach(cd, desc))) {
228		if (desc->bDescriptorType == UDESC_INTERFACE)
229			break;
230		if (desc->bDescriptorType == UDESC_ENDPOINT)
231			break;
232		if (desc->bDescriptorType == UDESC_ENDPOINT_SS_COMP) {
233			if (desc->bLength < sizeof(*ped)) {
234				/* endpoint companion descriptor is invalid */
235				break;
236			}
237			return ((struct usb_endpoint_ss_comp_descriptor *)desc);
238		}
239	}
240	return (NULL);
241}
242
243/*------------------------------------------------------------------------*
244 *	usbd_get_no_descriptors
245 *
246 * This function will count the total number of descriptors in the
247 * configuration descriptor of type "type".
248 *------------------------------------------------------------------------*/
249uint8_t
250usbd_get_no_descriptors(struct usb_config_descriptor *cd, uint8_t type)
251{
252	struct usb_descriptor *desc = NULL;
253	uint8_t count = 0;
254
255	while ((desc = usb_desc_foreach(cd, desc))) {
256		if (desc->bDescriptorType == type) {
257			count++;
258			if (count == 0xFF)
259				break;			/* crazy */
260		}
261	}
262	return (count);
263}
264
265/*------------------------------------------------------------------------*
266 *	usbd_get_no_alts
267 *
268 * Return value:
269 *   Number of alternate settings for the given interface descriptor
270 *   pointer. If the USB descriptor is corrupt, the returned value can
271 *   be greater than the actual number of alternate settings.
272 *------------------------------------------------------------------------*/
273uint8_t
274usbd_get_no_alts(struct usb_config_descriptor *cd,
275    struct usb_interface_descriptor *id)
276{
277	struct usb_descriptor *desc;
278	uint8_t n;
279	uint8_t ifaceno;
280
281	/* Reset interface count */
282
283	n = 0;
284
285	/* Get the interface number */
286
287	ifaceno = id->bInterfaceNumber;
288
289	/* Iterate all the USB descriptors */
290
291	desc = NULL;
292	while ((desc = usb_desc_foreach(cd, desc))) {
293		if ((desc->bDescriptorType == UDESC_INTERFACE) &&
294		    (desc->bLength >= sizeof(*id))) {
295			id = (struct usb_interface_descriptor *)desc;
296			if (id->bInterfaceNumber == ifaceno) {
297				n++;
298				if (n == 0xFF)
299					break;		/* crazy */
300			}
301		}
302	}
303	return (n);
304}
305