sys/bus/u4b/usb_parse.c

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