1 /* $FreeBSD$ */ 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 <dev/usb/usb.h> 28 #include <dev/usb/usb_mfunc.h> 29 30 #include <dev/usb/usb_core.h> 31 #include <dev/usb/usb_parse.h> 32 33 /*------------------------------------------------------------------------* 34 * usb2_desc_foreach 35 * 36 * This function is the safe way to iterate across the USB config 37 * descriptor. It contains several checks against invalid 38 * descriptors. If the "desc" argument passed to this function is 39 * "NULL" the first descriptor, if any, will be returned. 40 * 41 * Return values: 42 * NULL: End of descriptors 43 * Else: Next descriptor after "desc" 44 *------------------------------------------------------------------------*/ 45 struct usb2_descriptor * 46 usb2_desc_foreach(struct usb2_config_descriptor *cd, 47 struct usb2_descriptor *_desc) 48 { 49 uint8_t *desc_next; 50 uint8_t *start; 51 uint8_t *end; 52 uint8_t *desc; 53 54 /* be NULL safe */ 55 if (cd == NULL) 56 return (NULL); 57 58 /* We assume that the "wTotalLength" has been checked. */ 59 start = (uint8_t *)cd; 60 end = start + UGETW(cd->wTotalLength); 61 desc = (uint8_t *)_desc; 62 63 /* Get start of next USB descriptor. */ 64 if (desc == NULL) 65 desc = start; 66 else 67 desc = desc + desc[0]; 68 69 /* Check that the next USB descriptor is within the range. */ 70 if ((desc < start) || (desc >= end)) 71 return (NULL); /* out of range, or EOD */ 72 73 /* Check that the second next USB descriptor is within range. */ 74 desc_next = desc + desc[0]; 75 if ((desc_next < start) || (desc_next > end)) 76 return (NULL); /* out of range */ 77 78 /* Check minimum descriptor length. */ 79 if (desc[0] < 3) 80 return (NULL); /* too short descriptor */ 81 82 /* Return start of next descriptor. */ 83 return ((struct usb2_descriptor *)desc); 84 } 85 86 /*------------------------------------------------------------------------* 87 * usb2_find_idesc 88 * 89 * This function will return the interface descriptor, if any, that 90 * has index "iface_index" and alternate index "alt_index". 91 * 92 * Return values: 93 * NULL: End of descriptors 94 * Else: A valid interface descriptor 95 *------------------------------------------------------------------------*/ 96 struct usb2_interface_descriptor * 97 usb2_find_idesc(struct usb2_config_descriptor *cd, 98 uint8_t iface_index, uint8_t alt_index) 99 { 100 struct usb2_descriptor *desc = NULL; 101 struct usb2_interface_descriptor *id; 102 uint8_t curidx = 0; 103 uint8_t lastidx = 0; 104 uint8_t curaidx = 0; 105 uint8_t first = 1; 106 107 while ((desc = usb2_desc_foreach(cd, desc))) { 108 if ((desc->bDescriptorType == UDESC_INTERFACE) && 109 (desc->bLength >= sizeof(*id))) { 110 id = (void *)desc; 111 112 if (first) { 113 first = 0; 114 lastidx = id->bInterfaceNumber; 115 116 } else if (id->bInterfaceNumber != lastidx) { 117 118 lastidx = id->bInterfaceNumber; 119 curidx++; 120 curaidx = 0; 121 122 } else { 123 curaidx++; 124 } 125 126 if ((iface_index == curidx) && (alt_index == curaidx)) { 127 return (id); 128 } 129 } 130 } 131 return (NULL); 132 } 133 134 /*------------------------------------------------------------------------* 135 * usb2_find_edesc 136 * 137 * This function will return the endpoint descriptor for the passed 138 * interface index, alternate index and endpoint index. 139 * 140 * Return values: 141 * NULL: End of descriptors 142 * Else: A valid endpoint descriptor 143 *------------------------------------------------------------------------*/ 144 struct usb2_endpoint_descriptor * 145 usb2_find_edesc(struct usb2_config_descriptor *cd, 146 uint8_t iface_index, uint8_t alt_index, uint8_t ep_index) 147 { 148 struct usb2_descriptor *desc = NULL; 149 struct usb2_interface_descriptor *d; 150 uint8_t curidx = 0; 151 152 d = usb2_find_idesc(cd, iface_index, alt_index); 153 if (d == NULL) 154 return (NULL); 155 156 if (ep_index >= d->bNumEndpoints) /* quick exit */ 157 return (NULL); 158 159 desc = ((void *)d); 160 161 while ((desc = usb2_desc_foreach(cd, desc))) { 162 if (desc->bDescriptorType == UDESC_INTERFACE) { 163 break; 164 } 165 if (desc->bDescriptorType == UDESC_ENDPOINT) { 166 if (curidx == ep_index) { 167 if (desc->bLength < 168 sizeof(struct usb2_endpoint_descriptor)) { 169 /* endpoint index is invalid */ 170 break; 171 } 172 return ((void *)desc); 173 } 174 curidx++; 175 } 176 } 177 return (NULL); 178 } 179 180 /*------------------------------------------------------------------------* 181 * usb2_get_no_endpoints 182 * 183 * This function will count the total number of endpoints available. 184 *------------------------------------------------------------------------*/ 185 uint16_t 186 usb2_get_no_endpoints(struct usb2_config_descriptor *cd) 187 { 188 struct usb2_descriptor *desc = NULL; 189 uint16_t count = 0; 190 191 while ((desc = usb2_desc_foreach(cd, desc))) { 192 if (desc->bDescriptorType == UDESC_ENDPOINT) { 193 count++; 194 } 195 } 196 return (count); 197 } 198 199 /*------------------------------------------------------------------------* 200 * usb2_get_no_alts 201 * 202 * Return value: 203 * Number of alternate settings for the given "ifaceno". 204 * 205 * NOTE: The returned can be larger than the actual number of 206 * alternate settings. 207 *------------------------------------------------------------------------*/ 208 uint16_t 209 usb2_get_no_alts(struct usb2_config_descriptor *cd, uint8_t ifaceno) 210 { 211 struct usb2_descriptor *desc = NULL; 212 struct usb2_interface_descriptor *id; 213 uint16_t n = 0; 214 215 while ((desc = usb2_desc_foreach(cd, desc))) { 216 if ((desc->bDescriptorType == UDESC_INTERFACE) && 217 (desc->bLength >= sizeof(*id))) { 218 id = (void *)desc; 219 if (id->bInterfaceNumber == ifaceno) { 220 n++; 221 } 222 } 223 } 224 return (n); 225 } 226