src/common/ieee802_11_common.c

   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
  22 static 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_MSGDUMP, "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_MSGDUMP, "Unknown Microsoft "
  92                                    "information element ignored "
  93                                    "(type=%d len=%lu)\n",
  94                                    pos[3], (unsigned long) elen);
  95                         return -1;
  96                 }
  97                 break;
  98
  99         case OUI_BROADCOM:
 100                 switch (pos[3]) {
 101                 case VENDOR_HT_CAPAB_OUI_TYPE:
 102                         elems->vendor_ht_cap = pos;
 103                         elems->vendor_ht_cap_len = elen;
 104                         break;
 105                 default:
 106                         wpa_printf(MSG_MSGDUMP, "Unknown Broadcom "
 107                                    "information element ignored "
 108                                    "(type=%d len=%lu)\n",
 109                                    pos[3], (unsigned long) elen);
 110                         return -1;
 111                 }
 112                 break;
 113
 114         default:
 115                 wpa_printf(MSG_MSGDUMP, "unknown vendor specific information "
 116                            "element ignored (vendor OUI %02x:%02x:%02x "
 117                            "len=%lu)",
 118                            pos[0], pos[1], pos[2], (unsigned long) elen);
 119                 return -1;
 120         }
 121
 122         return 0;
 123 }
 124
 125
 126 /**
 127  * ieee802_11_parse_elems - Parse information elements in management frames
 128  * @start: Pointer to the start of IEs
 129  * @len: Length of IE buffer in octets
 130  * @elems: Data structure for parsed elements
 131  * @show_errors: Whether to show parsing errors in debug log
 132  * Returns: Parsing result
 133  */
 134 ParseRes ieee802_11_parse_elems(const u8 *start, size_t len,
 135                                 struct ieee802_11_elems *elems,
 136                                 int show_errors)
 137 {
 138         size_t left = len;
 139         const u8 *pos = start;
 140         int unknown = 0;
 141
 142         os_memset(elems, 0, sizeof(*elems));
 143
 144         while (left >= 2) {
 145                 u8 id, elen;
 146
 147                 id = *pos++;
 148                 elen = *pos++;
 149                 left -= 2;
 150
 151                 if (elen > left) {
 152                         if (show_errors) {
 153                                 wpa_printf(MSG_DEBUG, "IEEE 802.11 element "
 154                                            "parse failed (id=%d elen=%d "
 155                                            "left=%lu)",
 156                                            id, elen, (unsigned long) left);
 157                                 wpa_hexdump(MSG_MSGDUMP, "IEs", start, len);
 158                         }
 159                         return ParseFailed;
 160                 }
 161
 162                 switch (id) {
 163                 case WLAN_EID_SSID:
 164                         elems->ssid = pos;
 165                         elems->ssid_len = elen;
 166                         break;
 167                 case WLAN_EID_SUPP_RATES:
 168                         elems->supp_rates = pos;
 169                         elems->supp_rates_len = elen;
 170                         break;
 171                 case WLAN_EID_FH_PARAMS:
 172                         elems->fh_params = pos;
 173                         elems->fh_params_len = elen;
 174                         break;
 175                 case WLAN_EID_DS_PARAMS:
 176                         elems->ds_params = pos;
 177                         elems->ds_params_len = elen;
 178                         break;
 179                 case WLAN_EID_CF_PARAMS:
 180                         elems->cf_params = pos;
 181                         elems->cf_params_len = elen;
 182                         break;
 183                 case WLAN_EID_TIM:
 184                         elems->tim = pos;
 185                         elems->tim_len = elen;
 186                         break;
 187                 case WLAN_EID_IBSS_PARAMS:
 188                         elems->ibss_params = pos;
 189                         elems->ibss_params_len = elen;
 190                         break;
 191                 case WLAN_EID_CHALLENGE:
 192                         elems->challenge = pos;
 193                         elems->challenge_len = elen;
 194                         break;
 195                 case WLAN_EID_ERP_INFO:
 196                         elems->erp_info = pos;
 197                         elems->erp_info_len = elen;
 198                         break;
 199                 case WLAN_EID_EXT_SUPP_RATES:
 200                         elems->ext_supp_rates = pos;
 201                         elems->ext_supp_rates_len = elen;
 202                         break;
 203                 case WLAN_EID_VENDOR_SPECIFIC:
 204                         if (ieee802_11_parse_vendor_specific(pos, elen,
 205                                                              elems,
 206                                                              show_errors))
 207                                 unknown++;
 208                         break;
 209                 case WLAN_EID_RSN:
 210                         elems->rsn_ie = pos;
 211                         elems->rsn_ie_len = elen;
 212                         break;
 213                 case WLAN_EID_PWR_CAPABILITY:
 214                         elems->power_cap = pos;
 215                         elems->power_cap_len = elen;
 216                         break;
 217                 case WLAN_EID_SUPPORTED_CHANNELS:
 218                         elems->supp_channels = pos;
 219                         elems->supp_channels_len = elen;
 220                         break;
 221                 case WLAN_EID_MOBILITY_DOMAIN:
 222                         elems->mdie = pos;
 223                         elems->mdie_len = elen;
 224                         break;
 225                 case WLAN_EID_FAST_BSS_TRANSITION:
 226                         elems->ftie = pos;
 227                         elems->ftie_len = elen;
 228                         break;
 229                 case WLAN_EID_TIMEOUT_INTERVAL:
 230                         elems->timeout_int = pos;
 231                         elems->timeout_int_len = elen;
 232                         break;
 233                 case WLAN_EID_HT_CAP:
 234                         elems->ht_capabilities = pos;
 235                         elems->ht_capabilities_len = elen;
 236                         break;
 237                 case WLAN_EID_HT_OPERATION:
 238                         elems->ht_operation = pos;
 239                         elems->ht_operation_len = elen;
 240                         break;
 241                 default:
 242                         unknown++;
 243                         if (!show_errors)
 244                                 break;
 245                         wpa_printf(MSG_MSGDUMP, "IEEE 802.11 element parse "
 246                                    "ignored unknown element (id=%d elen=%d)",
 247                                    id, elen);
 248                         break;
 249                 }
 250
 251                 left -= elen;
 252                 pos += elen;
 253         }
 254
 255         if (left)
 256                 return ParseFailed;
 257
 258         return unknown ? ParseUnknown : ParseOK;
 259 }
 260
 261
 262 int ieee802_11_ie_count(const u8 *ies, size_t ies_len)
 263 {
 264         int count = 0;
 265         const u8 *pos, *end;
 266
 267         if (ies == NULL)
 268                 return 0;
 269
 270         pos = ies;
 271         end = ies + ies_len;
 272
 273         while (pos + 2 <= end) {
 274                 if (pos + 2 + pos[1] > end)
 275                         break;
 276                 count++;
 277                 pos += 2 + pos[1];
 278         }
 279
 280         return count;
 281 }
 282
 283
 284 struct wpabuf * ieee802_11_vendor_ie_concat(const u8 *ies, size_t ies_len,
 285                                             u32 oui_type)
 286 {
 287         struct wpabuf *buf;
 288         const u8 *end, *pos, *ie;
 289
 290         pos = ies;
 291         end = ies + ies_len;
 292         ie = NULL;
 293
 294         while (pos + 1 < end) {
 295                 if (pos + 2 + pos[1] > end)
 296                         return NULL;
 297                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
 298                     WPA_GET_BE32(&pos[2]) == oui_type) {
 299                         ie = pos;
 300                         break;
 301                 }
 302                 pos += 2 + pos[1];
 303         }
 304
 305         if (ie == NULL)
 306                 return NULL; /* No specified vendor IE found */
 307
 308         buf = wpabuf_alloc(ies_len);
 309         if (buf == NULL)
 310                 return NULL;
 311
 312         /*
 313          * There may be multiple vendor IEs in the message, so need to
 314          * concatenate their data fields.
 315          */
 316         while (pos + 1 < end) {
 317                 if (pos + 2 + pos[1] > end)
 318                         break;
 319                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
 320                     WPA_GET_BE32(&pos[2]) == oui_type)
 321                         wpabuf_put_data(buf, pos + 6, pos[1] - 4);
 322                 pos += 2 + pos[1];
 323         }
 324
 325         return buf;
 326 }