src/common/ieee802_11_common.c

   1 /*
   2  * IEEE 802.11 Common routines
   3  * Copyright (c) 2002-2008, 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(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 WME_OUI_TYPE: /* this is a Wi-Fi WME info. element */
  53                         if (elen < 5) {
  54                                 wpa_printf(MSG_MSGDUMP, "short WME "
  55                                            "information element ignored "
  56                                            "(len=%lu)",
  57                                            (unsigned long) elen);
  58                                 return -1;
  59                         }
  60                         switch (pos[4]) {
  61                         case WME_OUI_SUBTYPE_INFORMATION_ELEMENT:
  62                         case WME_OUI_SUBTYPE_PARAMETER_ELEMENT:
  63                                 elems->wme = pos;
  64                                 elems->wme_len = elen;
  65                                 break;
  66                         case WME_OUI_SUBTYPE_TSPEC_ELEMENT:
  67                                 elems->wme_tspec = pos;
  68                                 elems->wme_tspec_len = elen;
  69                                 break;
  70                         default:
  71                                 wpa_printf(MSG_MSGDUMP, "unknown WME "
  72                                            "information element ignored "
  73                                            "(subtype=%d len=%lu)",
  74                                            pos[4], (unsigned long) elen);
  75                                 return -1;
  76                         }
  77                         break;
  78                 default:
  79                         wpa_printf(MSG_MSGDUMP, "Unknown Microsoft "
  80                                    "information element ignored "
  81                                    "(type=%d len=%lu)\n",
  82                                    pos[3], (unsigned long) elen);
  83                         return -1;
  84                 }
  85                 break;
  86
  87         default:
  88                 wpa_printf(MSG_MSGDUMP, "unknown vendor specific information "
  89                            "element ignored (vendor OUI %02x:%02x:%02x "
  90                            "len=%lu)",
  91                            pos[0], pos[1], pos[2], (unsigned long) elen);
  92                 return -1;
  93         }
  94
  95         return 0;
  96 }
  97
  98
  99 ParseRes ieee802_11_parse_elems(u8 *start, size_t len,
 100                                 struct ieee802_11_elems *elems,
 101                                 int show_errors)
 102 {
 103         size_t left = len;
 104         u8 *pos = start;
 105         int unknown = 0;
 106
 107         os_memset(elems, 0, sizeof(*elems));
 108
 109         while (left >= 2) {
 110                 u8 id, elen;
 111
 112                 id = *pos++;
 113                 elen = *pos++;
 114                 left -= 2;
 115
 116                 if (elen > left) {
 117                         if (show_errors) {
 118                                 wpa_printf(MSG_DEBUG, "IEEE 802.11 element "
 119                                            "parse failed (id=%d elen=%d "
 120                                            "left=%lu)",
 121                                            id, elen, (unsigned long) left);
 122                                 wpa_hexdump(MSG_MSGDUMP, "IEs", start, len);
 123                         }
 124                         return ParseFailed;
 125                 }
 126
 127                 switch (id) {
 128                 case WLAN_EID_SSID:
 129                         elems->ssid = pos;
 130                         elems->ssid_len = elen;
 131                         break;
 132                 case WLAN_EID_SUPP_RATES:
 133                         elems->supp_rates = pos;
 134                         elems->supp_rates_len = elen;
 135                         break;
 136                 case WLAN_EID_FH_PARAMS:
 137                         elems->fh_params = pos;
 138                         elems->fh_params_len = elen;
 139                         break;
 140                 case WLAN_EID_DS_PARAMS:
 141                         elems->ds_params = pos;
 142                         elems->ds_params_len = elen;
 143                         break;
 144                 case WLAN_EID_CF_PARAMS:
 145                         elems->cf_params = pos;
 146                         elems->cf_params_len = elen;
 147                         break;
 148                 case WLAN_EID_TIM:
 149                         elems->tim = pos;
 150                         elems->tim_len = elen;
 151                         break;
 152                 case WLAN_EID_IBSS_PARAMS:
 153                         elems->ibss_params = pos;
 154                         elems->ibss_params_len = elen;
 155                         break;
 156                 case WLAN_EID_CHALLENGE:
 157                         elems->challenge = pos;
 158                         elems->challenge_len = elen;
 159                         break;
 160                 case WLAN_EID_ERP_INFO:
 161                         elems->erp_info = pos;
 162                         elems->erp_info_len = elen;
 163                         break;
 164                 case WLAN_EID_EXT_SUPP_RATES:
 165                         elems->ext_supp_rates = pos;
 166                         elems->ext_supp_rates_len = elen;
 167                         break;
 168                 case WLAN_EID_VENDOR_SPECIFIC:
 169                         if (ieee802_11_parse_vendor_specific(pos, elen,
 170                                                              elems,
 171                                                              show_errors))
 172                                 unknown++;
 173                         break;
 174                 case WLAN_EID_RSN:
 175                         elems->rsn_ie = pos;
 176                         elems->rsn_ie_len = elen;
 177                         break;
 178                 case WLAN_EID_PWR_CAPABILITY:
 179                         elems->power_cap = pos;
 180                         elems->power_cap_len = elen;
 181                         break;
 182                 case WLAN_EID_SUPPORTED_CHANNELS:
 183                         elems->supp_channels = pos;
 184                         elems->supp_channels_len = elen;
 185                         break;
 186                 case WLAN_EID_MOBILITY_DOMAIN:
 187                         elems->mdie = pos;
 188                         elems->mdie_len = elen;
 189                         break;
 190                 case WLAN_EID_FAST_BSS_TRANSITION:
 191                         elems->ftie = pos;
 192                         elems->ftie_len = elen;
 193                         break;
 194                 case WLAN_EID_HT_CAP:
 195                         elems->ht_capabilities = pos;
 196                         elems->ht_capabilities_len = elen;
 197                         break;
 198                 case WLAN_EID_HT_OPERATION:
 199                         elems->ht_operation = pos;
 200                         elems->ht_operation_len = elen;
 201                         break;
 202                 default:
 203                         unknown++;
 204                         if (!show_errors)
 205                                 break;
 206                         wpa_printf(MSG_MSGDUMP, "IEEE 802.11 element parse "
 207                                    "ignored unknown element (id=%d elen=%d)",
 208                                    id, elen);
 209                         break;
 210                 }
 211
 212                 left -= elen;
 213                 pos += elen;
 214         }
 215
 216         if (left)
 217                 return ParseFailed;
 218
 219         return unknown ? ParseUnknown : ParseOK;
 220 }