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 } 299