ieee802_11_common.c revision 8d520ff1dc2da35cdca849e982051b86468016d8
1/* 2 * IEEE 802.11 Common routines 3 * Copyright (c) 2002-2009, Jouni Malinen <j@w1.fi> 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License version 2 as 7 * published by the Free Software Foundation. 8 * 9 * Alternatively, this software may be distributed under the terms of BSD 10 * license. 11 * 12 * See README and COPYING for more details. 13 */ 14 15#include "includes.h" 16 17#include "common.h" 18#include "ieee802_11_defs.h" 19#include "ieee802_11_common.h" 20 21 22static int ieee802_11_parse_vendor_specific(const u8 *pos, size_t elen, 23 struct ieee802_11_elems *elems, 24 int show_errors) 25{ 26 unsigned int oui; 27 28 /* first 3 bytes in vendor specific information element are the IEEE 29 * OUI of the vendor. The following byte is used a vendor specific 30 * sub-type. */ 31 if (elen < 4) { 32 if (show_errors) { 33 wpa_printf(MSG_MSGDUMP, "short vendor specific " 34 "information element ignored (len=%lu)", 35 (unsigned long) elen); 36 } 37 return -1; 38 } 39 40 oui = WPA_GET_BE24(pos); 41 switch (oui) { 42 case OUI_MICROSOFT: 43 /* Microsoft/Wi-Fi information elements are further typed and 44 * subtyped */ 45 switch (pos[3]) { 46 case 1: 47 /* Microsoft OUI (00:50:F2) with OUI Type 1: 48 * real WPA information element */ 49 elems->wpa_ie = pos; 50 elems->wpa_ie_len = elen; 51 break; 52 case WMM_OUI_TYPE: 53 /* WMM information element */ 54 if (elen < 5) { 55 wpa_printf(MSG_MSGDUMP, "short WMM " 56 "information element ignored " 57 "(len=%lu)", 58 (unsigned long) elen); 59 return -1; 60 } 61 switch (pos[4]) { 62 case WMM_OUI_SUBTYPE_INFORMATION_ELEMENT: 63 case WMM_OUI_SUBTYPE_PARAMETER_ELEMENT: 64 /* 65 * Share same pointer since only one of these 66 * is used and they start with same data. 67 * Length field can be used to distinguish the 68 * IEs. 69 */ 70 elems->wmm = pos; 71 elems->wmm_len = elen; 72 break; 73 case WMM_OUI_SUBTYPE_TSPEC_ELEMENT: 74 elems->wmm_tspec = pos; 75 elems->wmm_tspec_len = elen; 76 break; 77 default: 78 wpa_printf(MSG_EXCESSIVE, "unknown WMM " 79 "information element ignored " 80 "(subtype=%d len=%lu)", 81 pos[4], (unsigned long) elen); 82 return -1; 83 } 84 break; 85 case 4: 86 /* Wi-Fi Protected Setup (WPS) IE */ 87 elems->wps_ie = pos; 88 elems->wps_ie_len = elen; 89 break; 90 default: 91 wpa_printf(MSG_EXCESSIVE, "Unknown Microsoft " 92 "information element ignored " 93 "(type=%d len=%lu)", 94 pos[3], (unsigned long) elen); 95 return -1; 96 } 97 break; 98 99 case OUI_WFA: 100 switch (pos[3]) { 101 case P2P_OUI_TYPE: 102 /* Wi-Fi Alliance - P2P IE */ 103 elems->p2p = pos; 104 elems->p2p_len = elen; 105 break; 106 default: 107 wpa_printf(MSG_MSGDUMP, "Unknown WFA " 108 "information element ignored " 109 "(type=%d len=%lu)\n", 110 pos[3], (unsigned long) elen); 111 return -1; 112 } 113 break; 114 115 case OUI_BROADCOM: 116 switch (pos[3]) { 117 case VENDOR_HT_CAPAB_OUI_TYPE: 118 elems->vendor_ht_cap = pos; 119 elems->vendor_ht_cap_len = elen; 120 break; 121 default: 122 wpa_printf(MSG_EXCESSIVE, "Unknown Broadcom " 123 "information element ignored " 124 "(type=%d len=%lu)", 125 pos[3], (unsigned long) elen); 126 return -1; 127 } 128 break; 129 130 default: 131 wpa_printf(MSG_EXCESSIVE, "unknown vendor specific " 132 "information element ignored (vendor OUI " 133 "%02x:%02x:%02x len=%lu)", 134 pos[0], pos[1], pos[2], (unsigned long) elen); 135 return -1; 136 } 137 138 return 0; 139} 140 141 142/** 143 * ieee802_11_parse_elems - Parse information elements in management frames 144 * @start: Pointer to the start of IEs 145 * @len: Length of IE buffer in octets 146 * @elems: Data structure for parsed elements 147 * @show_errors: Whether to show parsing errors in debug log 148 * Returns: Parsing result 149 */ 150ParseRes ieee802_11_parse_elems(const u8 *start, size_t len, 151 struct ieee802_11_elems *elems, 152 int show_errors) 153{ 154 size_t left = len; 155 const u8 *pos = start; 156 int unknown = 0; 157 158 os_memset(elems, 0, sizeof(*elems)); 159 160 while (left >= 2) { 161 u8 id, elen; 162 163 id = *pos++; 164 elen = *pos++; 165 left -= 2; 166 167 if (elen > left) { 168 if (show_errors) { 169 wpa_printf(MSG_DEBUG, "IEEE 802.11 element " 170 "parse failed (id=%d elen=%d " 171 "left=%lu)", 172 id, elen, (unsigned long) left); 173 wpa_hexdump(MSG_MSGDUMP, "IEs", start, len); 174 } 175 return ParseFailed; 176 } 177 178 switch (id) { 179 case WLAN_EID_SSID: 180 elems->ssid = pos; 181 elems->ssid_len = elen; 182 break; 183 case WLAN_EID_SUPP_RATES: 184 elems->supp_rates = pos; 185 elems->supp_rates_len = elen; 186 break; 187 case WLAN_EID_FH_PARAMS: 188 elems->fh_params = pos; 189 elems->fh_params_len = elen; 190 break; 191 case WLAN_EID_DS_PARAMS: 192 elems->ds_params = pos; 193 elems->ds_params_len = elen; 194 break; 195 case WLAN_EID_CF_PARAMS: 196 elems->cf_params = pos; 197 elems->cf_params_len = elen; 198 break; 199 case WLAN_EID_TIM: 200 elems->tim = pos; 201 elems->tim_len = elen; 202 break; 203 case WLAN_EID_IBSS_PARAMS: 204 elems->ibss_params = pos; 205 elems->ibss_params_len = elen; 206 break; 207 case WLAN_EID_CHALLENGE: 208 elems->challenge = pos; 209 elems->challenge_len = elen; 210 break; 211 case WLAN_EID_ERP_INFO: 212 elems->erp_info = pos; 213 elems->erp_info_len = elen; 214 break; 215 case WLAN_EID_EXT_SUPP_RATES: 216 elems->ext_supp_rates = pos; 217 elems->ext_supp_rates_len = elen; 218 break; 219 case WLAN_EID_VENDOR_SPECIFIC: 220 if (ieee802_11_parse_vendor_specific(pos, elen, 221 elems, 222 show_errors)) 223 unknown++; 224 break; 225 case WLAN_EID_RSN: 226 elems->rsn_ie = pos; 227 elems->rsn_ie_len = elen; 228 break; 229 case WLAN_EID_PWR_CAPABILITY: 230 elems->power_cap = pos; 231 elems->power_cap_len = elen; 232 break; 233 case WLAN_EID_SUPPORTED_CHANNELS: 234 elems->supp_channels = pos; 235 elems->supp_channels_len = elen; 236 break; 237 case WLAN_EID_MOBILITY_DOMAIN: 238 elems->mdie = pos; 239 elems->mdie_len = elen; 240 break; 241 case WLAN_EID_FAST_BSS_TRANSITION: 242 elems->ftie = pos; 243 elems->ftie_len = elen; 244 break; 245 case WLAN_EID_TIMEOUT_INTERVAL: 246 elems->timeout_int = pos; 247 elems->timeout_int_len = elen; 248 break; 249 case WLAN_EID_HT_CAP: 250 elems->ht_capabilities = pos; 251 elems->ht_capabilities_len = elen; 252 break; 253 case WLAN_EID_HT_OPERATION: 254 elems->ht_operation = pos; 255 elems->ht_operation_len = elen; 256 break; 257 case WLAN_EID_LINK_ID: 258 if (elen < 18) 259 break; 260 elems->link_id = pos; 261 break; 262 default: 263 unknown++; 264 if (!show_errors) 265 break; 266 wpa_printf(MSG_MSGDUMP, "IEEE 802.11 element parse " 267 "ignored unknown element (id=%d elen=%d)", 268 id, elen); 269 break; 270 } 271 272 left -= elen; 273 pos += elen; 274 } 275 276 if (left) 277 return ParseFailed; 278 279 return unknown ? ParseUnknown : ParseOK; 280} 281 282 283int ieee802_11_ie_count(const u8 *ies, size_t ies_len) 284{ 285 int count = 0; 286 const u8 *pos, *end; 287 288 if (ies == NULL) 289 return 0; 290 291 pos = ies; 292 end = ies + ies_len; 293 294 while (pos + 2 <= end) { 295 if (pos + 2 + pos[1] > end) 296 break; 297 count++; 298 pos += 2 + pos[1]; 299 } 300 301 return count; 302} 303 304 305struct wpabuf * ieee802_11_vendor_ie_concat(const u8 *ies, size_t ies_len, 306 u32 oui_type) 307{ 308 struct wpabuf *buf; 309 const u8 *end, *pos, *ie; 310 311 pos = ies; 312 end = ies + ies_len; 313 ie = NULL; 314 315 while (pos + 1 < end) { 316 if (pos + 2 + pos[1] > end) 317 return NULL; 318 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 && 319 WPA_GET_BE32(&pos[2]) == oui_type) { 320 ie = pos; 321 break; 322 } 323 pos += 2 + pos[1]; 324 } 325 326 if (ie == NULL) 327 return NULL; /* No specified vendor IE found */ 328 329 buf = wpabuf_alloc(ies_len); 330 if (buf == NULL) 331 return NULL; 332 333 /* 334 * There may be multiple vendor IEs in the message, so need to 335 * concatenate their data fields. 336 */ 337 while (pos + 1 < end) { 338 if (pos + 2 + pos[1] > end) 339 break; 340 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 && 341 WPA_GET_BE32(&pos[2]) == oui_type) 342 wpabuf_put_data(buf, pos + 6, pos[1] - 4); 343 pos += 2 + pos[1]; 344 } 345 346 return buf; 347} 348