1 /* $FreeBSD: head/sys/dev/usb/usb_parse.c 250204 2013-05-03 09:23:06Z hselasky $ */
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 #include <sys/stdint.h>
28 #include <sys/param.h>
29 #include <sys/queue.h>
30 #include <sys/types.h>
31 #include <sys/systm.h>
32 #include <sys/kernel.h>
33 #include <sys/bus.h>
34 #include <sys/module.h>
35 #include <sys/lock.h>
36 #include <sys/condvar.h>
37 #include <sys/sysctl.h>
38 #include <sys/unistd.h>
39 #include <sys/callout.h>
40 #include <sys/malloc.h>
41 #include <sys/caps.h>
42
43 #include <bus/u4b/usb.h>
44 #include <bus/u4b/usbdi.h>
45 #include <bus/u4b/usbdi_util.h>
46
47 #define USB_DEBUG_VAR usb_debug
48
49 #include <bus/u4b/usb_core.h>
50 #include <bus/u4b/usb_debug.h>
51
52 /*------------------------------------------------------------------------*
53 * usb_desc_foreach
54 *
55 * This function is the safe way to iterate across the USB config
56 * descriptor. It contains several checks against invalid
57 * descriptors. If the "desc" argument passed to this function is
58 * "NULL" the first descriptor, if any, will be returned.
59 *
60 * Return values:
61 * NULL: End of descriptors
62 * Else: Next descriptor after "desc"
63 *------------------------------------------------------------------------*/
64 struct usb_descriptor *
usb_desc_foreach(struct usb_config_descriptor * cd,struct usb_descriptor * _desc)65 usb_desc_foreach(struct usb_config_descriptor *cd,
66 struct usb_descriptor *_desc)
67 {
68 uint8_t *desc_next;
69 uint8_t *start;
70 uint8_t *end;
71 uint8_t *desc;
72
73 /* be NULL safe */
74 if (cd == NULL)
75 return (NULL);
76
77 /* We assume that the "wTotalLength" has been checked. */
78 start = (uint8_t *)cd;
79 end = start + UGETW(cd->wTotalLength);
80 desc = (uint8_t *)_desc;
81
82 /* Get start of next USB descriptor. */
83 if (desc == NULL)
84 desc = start;
85 else
86 desc = desc + desc[0];
87
88 /* Check that the next USB descriptor is within the range. */
89 if ((desc < start) || (desc >= end))
90 return (NULL); /* out of range, or EOD */
91
92 /* Check that the second next USB descriptor is within range. */
93 desc_next = desc + desc[0];
94 if ((desc_next < start) || (desc_next > end))
95 return (NULL); /* out of range */
96
97 /* Check minimum descriptor length. */
98 if (desc[0] < 3)
99 return (NULL); /* too short descriptor */
100
101 /* Return start of next descriptor. */
102 return ((struct usb_descriptor *)desc);
103 }
104
105 /*------------------------------------------------------------------------*
106 * usb_idesc_foreach
107 *
108 * This function will iterate the interface descriptors in the config
109 * descriptor. The parse state structure should be zeroed before
110 * calling this function the first time.
111 *
112 * Return values:
113 * NULL: End of descriptors
114 * Else: A valid interface descriptor
115 *------------------------------------------------------------------------*/
116 struct usb_interface_descriptor *
usb_idesc_foreach(struct usb_config_descriptor * cd,struct usb_idesc_parse_state * ps)117 usb_idesc_foreach(struct usb_config_descriptor *cd,
118 struct usb_idesc_parse_state *ps)
119 {
120 struct usb_interface_descriptor *id;
121 uint8_t new_iface;
122
123 /* retrieve current descriptor */
124 id = (struct usb_interface_descriptor *)ps->desc;
125 /* default is to start a new interface */
126 new_iface = 1;
127
128 while (1) {
129 id = (struct usb_interface_descriptor *)
130 usb_desc_foreach(cd, (struct usb_descriptor *)id);
131 if (id == NULL)
132 break;
133 if ((id->bDescriptorType == UDESC_INTERFACE) &&
134 (id->bLength >= sizeof(*id))) {
135 if (ps->iface_no_last == id->bInterfaceNumber)
136 new_iface = 0;
137 ps->iface_no_last = id->bInterfaceNumber;
138 break;
139 }
140 }
141
142 if (ps->desc == NULL) {
143 /* first time or zero descriptors */
144 } else if (new_iface) {
145 /* new interface */
146 ps->iface_index ++;
147 ps->iface_index_alt = 0;
148 } else {
149 /* new alternate interface */
150 ps->iface_index_alt ++;
151 }
152 #if (USB_IFACE_MAX <= 0)
153 #error "USB_IFACE_MAX must be defined greater than zero"
154 #endif
155 /* check for too many interfaces */
156 if (ps->iface_index >= USB_IFACE_MAX) {
157 DPRINTF("Interface limit reached\n");
158 id = NULL;
159 }
160
161 /* store and return current descriptor */
162 ps->desc = (struct usb_descriptor *)id;
163 return (id);
164 }
165
166 /*------------------------------------------------------------------------*
167 * usb_edesc_foreach
168 *
169 * This function will iterate all the endpoint descriptors within an
170 * interface descriptor. Starting value for the "ped" argument should
171 * be a valid interface descriptor.
172 *
173 * Return values:
174 * NULL: End of descriptors
175 * Else: A valid endpoint descriptor
176 *------------------------------------------------------------------------*/
177 struct usb_endpoint_descriptor *
usb_edesc_foreach(struct usb_config_descriptor * cd,struct usb_endpoint_descriptor * ped)178 usb_edesc_foreach(struct usb_config_descriptor *cd,
179 struct usb_endpoint_descriptor *ped)
180 {
181 struct usb_descriptor *desc;
182
183 desc = ((struct usb_descriptor *)ped);
184
185 while ((desc = usb_desc_foreach(cd, desc))) {
186 if (desc->bDescriptorType == UDESC_INTERFACE) {
187 break;
188 }
189 if (desc->bDescriptorType == UDESC_ENDPOINT) {
190 if (desc->bLength < sizeof(*ped)) {
191 /* endpoint descriptor is invalid */
192 break;
193 }
194 return ((struct usb_endpoint_descriptor *)desc);
195 }
196 }
197 return (NULL);
198 }
199
200 /*------------------------------------------------------------------------*
201 * usb_ed_comp_foreach
202 *
203 * This function will iterate all the endpoint companion descriptors
204 * within an endpoint descriptor in an interface descriptor. Starting
205 * value for the "ped" argument should be a valid endpoint companion
206 * descriptor.
207 *
208 * Return values:
209 * NULL: End of descriptors
210 * Else: A valid endpoint companion descriptor
211 *------------------------------------------------------------------------*/
212 struct usb_endpoint_ss_comp_descriptor *
usb_ed_comp_foreach(struct usb_config_descriptor * cd,struct usb_endpoint_ss_comp_descriptor * ped)213 usb_ed_comp_foreach(struct usb_config_descriptor *cd,
214 struct usb_endpoint_ss_comp_descriptor *ped)
215 {
216 struct usb_descriptor *desc;
217
218 desc = ((struct usb_descriptor *)ped);
219
220 while ((desc = usb_desc_foreach(cd, desc))) {
221 if (desc->bDescriptorType == UDESC_INTERFACE)
222 break;
223 if (desc->bDescriptorType == UDESC_ENDPOINT)
224 break;
225 if (desc->bDescriptorType == UDESC_ENDPOINT_SS_COMP) {
226 if (desc->bLength < sizeof(*ped)) {
227 /* endpoint companion descriptor is invalid */
228 break;
229 }
230 return ((struct usb_endpoint_ss_comp_descriptor *)desc);
231 }
232 }
233 return (NULL);
234 }
235
236 /*------------------------------------------------------------------------*
237 * usbd_get_no_descriptors
238 *
239 * This function will count the total number of descriptors in the
240 * configuration descriptor of type "type".
241 *------------------------------------------------------------------------*/
242 uint8_t
usbd_get_no_descriptors(struct usb_config_descriptor * cd,uint8_t type)243 usbd_get_no_descriptors(struct usb_config_descriptor *cd, uint8_t type)
244 {
245 struct usb_descriptor *desc = NULL;
246 uint8_t count = 0;
247
248 while ((desc = usb_desc_foreach(cd, desc))) {
249 if (desc->bDescriptorType == type) {
250 count++;
251 if (count == 0xFF)
252 break; /* crazy */
253 }
254 }
255 return (count);
256 }
257
258 /*------------------------------------------------------------------------*
259 * usbd_get_no_alts
260 *
261 * Return value:
262 * Number of alternate settings for the given interface descriptor
263 * pointer. If the USB descriptor is corrupt, the returned value can
264 * be greater than the actual number of alternate settings.
265 *------------------------------------------------------------------------*/
266 uint8_t
usbd_get_no_alts(struct usb_config_descriptor * cd,struct usb_interface_descriptor * id)267 usbd_get_no_alts(struct usb_config_descriptor *cd,
268 struct usb_interface_descriptor *id)
269 {
270 struct usb_descriptor *desc;
271 uint8_t n;
272 uint8_t ifaceno;
273
274 /* Reset interface count */
275
276 n = 0;
277
278 /* Get the interface number */
279
280 ifaceno = id->bInterfaceNumber;
281
282 /* Iterate all the USB descriptors */
283
284 desc = NULL;
285 while ((desc = usb_desc_foreach(cd, desc))) {
286 if ((desc->bDescriptorType == UDESC_INTERFACE) &&
287 (desc->bLength >= sizeof(*id))) {
288 id = (struct usb_interface_descriptor *)desc;
289 if (id->bInterfaceNumber == ifaceno) {
290 n++;
291 if (n == 0xFF)
292 break; /* crazy */
293 }
294 }
295 }
296 return (n);
297 }
298