1 /* $FreeBSD: releng/11.2/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 *------------------------------------------------------------------------*/
71 struct usb_descriptor *
72 usb_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 *------------------------------------------------------------------------*/
123 struct usb_interface_descriptor *
124 usb_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 *------------------------------------------------------------------------*/
184 struct usb_endpoint_descriptor *
185 usb_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 *------------------------------------------------------------------------*/
219 struct usb_endpoint_ss_comp_descriptor *
220 usb_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 *------------------------------------------------------------------------*/
249 uint8_t
250 usbd_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 *------------------------------------------------------------------------*/
273 uint8_t
274 usbd_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 }
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