contrib/hostapd-0.5.8/wme.c

   1 /*
   2  * hostapd / WMM (Wi-Fi Multimedia)
   3  * Copyright 2002-2003, Instant802 Networks, Inc.
   4  * Copyright 2005-2006, Devicescape Software, Inc.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  * Alternatively, this software may be distributed under the terms of BSD
  11  * license.
  12  *
  13  * See README and COPYING for more details.
  14  */
  15
  16 #include "includes.h"
  17
  18 #include "hostapd.h"
  19 #include "ieee802_11.h"
  20 #include "wme.h"
  21 #include "sta_info.h"
  22 #include "driver.h"
  23
  24
  25 /* TODO: maintain separate sequence and fragment numbers for each AC
  26  * TODO: IGMP snooping to track which multicasts to forward - and use QOS-DATA
  27  * if only WME stations are receiving a certain group */
  28
  29
  30 static u8 wme_oui[3] = { 0x00, 0x50, 0xf2 };
  31
  32
  33 /* Add WME Parameter Element to Beacon and Probe Response frames. */
  34 u8 * hostapd_eid_wme(struct hostapd_data *hapd, u8 *eid)
  35 {
  36         u8 *pos = eid;
  37         struct wme_parameter_element *wme =
  38                 (struct wme_parameter_element *) (pos + 2);
  39         int e;
  40
  41         if (!hapd->conf->wme_enabled)
  42                 return eid;
  43         eid[0] = WLAN_EID_VENDOR_SPECIFIC;
  44         wme->oui[0] = 0x00;
  45         wme->oui[1] = 0x50;
  46         wme->oui[2] = 0xf2;
  47         wme->oui_type = WME_OUI_TYPE;
  48         wme->oui_subtype = WME_OUI_SUBTYPE_PARAMETER_ELEMENT;
  49         wme->version = WME_VERSION;
  50         wme->acInfo = hapd->parameter_set_count & 0xf;
  51
  52         /* fill in a parameter set record for each AC */
  53         for (e = 0; e < 4; e++) {
  54                 struct wme_ac_parameter *ac = &wme->ac[e];
  55                 struct hostapd_wme_ac_params *acp =
  56                         &hapd->iconf->wme_ac_params[e];
  57
  58                 ac->aifsn = acp->aifs;
  59                 ac->acm = acp->admission_control_mandatory;
  60                 ac->aci = e;
  61                 ac->reserved = 0;
  62                 ac->eCWmin = acp->cwmin;
  63                 ac->eCWmax = acp->cwmax;
  64                 ac->txopLimit = host_to_le16(acp->txopLimit);
  65         }
  66
  67         pos = (u8 *) (wme + 1);
  68         eid[1] = pos - eid - 2; /* element length */
  69
  70         return pos;
  71 }
  72
  73
  74 /* This function is called when a station sends an association request with
  75  * WME info element. The function returns zero on success or non-zero on any
  76  * error in WME element. eid does not include Element ID and Length octets. */
  77 int hostapd_eid_wme_valid(struct hostapd_data *hapd, u8 *eid, size_t len)
  78 {
  79         struct wme_information_element *wme;
  80
  81         wpa_hexdump(MSG_MSGDUMP, "WME IE", eid, len);
  82
  83         if (len < sizeof(struct wme_information_element)) {
  84                 printf("Too short WME IE (len=%lu)\n", (unsigned long) len);
  85                 return -1;
  86         }
  87
  88         wme = (struct wme_information_element *) eid;
  89         HOSTAPD_DEBUG(HOSTAPD_DEBUG_MINIMAL, "Validating WME IE: OUI "
  90                       "%02x:%02x:%02x  OUI type %d  OUI sub-type %d  "
  91                       "version %d\n",
  92                       wme->oui[0], wme->oui[1], wme->oui[2], wme->oui_type,
  93                       wme->oui_subtype, wme->version);
  94         if (memcmp(wme->oui, wme_oui, sizeof(wme_oui)) != 0 ||
  95             wme->oui_type != WME_OUI_TYPE ||
  96             wme->oui_subtype != WME_OUI_SUBTYPE_INFORMATION_ELEMENT ||
  97             wme->version != WME_VERSION) {
  98                 printf("Unsupported WME IE OUI/Type/Subtype/Version\n");
  99                 return -1;
 100         }
 101
 102         return 0;
 103 }
 104
 105
 106 /* This function is called when a station sends an ACK frame for an AssocResp
 107  * frame (status=success) and the matching AssocReq contained a WME element.
 108  */
 109 int hostapd_wme_sta_config(struct hostapd_data *hapd, struct sta_info *sta)
 110 {
 111         /* update kernel STA data for WME related items (WLAN_STA_WPA flag) */
 112         if (sta->flags & WLAN_STA_WME)
 113                 hostapd_sta_set_flags(hapd, sta->addr, WLAN_STA_WME, ~0);
 114         else
 115                 hostapd_sta_set_flags(hapd, sta->addr, 0, ~WLAN_STA_WME);
 116
 117         return 0;
 118 }
 119
 120
 121 static void wme_send_action(struct hostapd_data *hapd, const u8 *addr,
 122                             const struct wme_tspec_info_element *tspec,
 123                             u8 action_code, u8 dialogue_token, u8 status_code)
 124 {
 125         u8 buf[256];
 126         struct ieee80211_mgmt *m = (struct ieee80211_mgmt *) buf;
 127         struct wme_tspec_info_element *t =
 128                 (struct wme_tspec_info_element *)
 129                 m->u.action.u.wme_action.variable;
 130         int len;
 131
 132         hostapd_logger(hapd, addr, HOSTAPD_MODULE_IEEE80211,
 133                        HOSTAPD_LEVEL_DEBUG,
 134                        "action response - reason %d", status_code);
 135         memset(buf, 0, sizeof(buf));
 136         m->frame_control = IEEE80211_FC(WLAN_FC_TYPE_MGMT,
 137                                         WLAN_FC_STYPE_ACTION);
 138         memcpy(m->da, addr, ETH_ALEN);
 139         memcpy(m->sa, hapd->own_addr, ETH_ALEN);
 140         memcpy(m->bssid, hapd->own_addr, ETH_ALEN);
 141         m->u.action.category = WME_ACTION_CATEGORY;
 142         m->u.action.u.wme_action.action_code = action_code;
 143         m->u.action.u.wme_action.dialog_token = dialogue_token;
 144         m->u.action.u.wme_action.status_code = status_code;
 145         memcpy(t, tspec, sizeof(struct wme_tspec_info_element));
 146         len = ((u8 *) (t + 1)) - buf;
 147
 148         if (hostapd_send_mgmt_frame(hapd, m, len, 0) < 0)
 149                 perror("wme_send_action: send");
 150 }
 151
 152
 153 /* given frame data payload size in bytes, and data_rate in bits per second
 154  * returns time to complete frame exchange */
 155 /* FIX: should not use floating point types */
 156 static double wme_frame_exchange_time(int bytes, int data_rate, int encryption,
 157                                       int cts_protection)
 158 {
 159         /* TODO: account for MAC/PHY headers correctly */
 160         /* TODO: account for encryption headers */
 161         /* TODO: account for WDS headers */
 162         /* TODO: account for CTS protection */
 163         /* TODO: account for SIFS + ACK at minimum PHY rate */
 164         return (bytes + 400) * 8.0 / data_rate;
 165 }
 166
 167
 168 static void wme_setup_request(struct hostapd_data *hapd,
 169                               struct ieee80211_mgmt *mgmt,
 170                               struct wme_tspec_info_element *tspec, size_t len)
 171 {
 172         /* FIX: should not use floating point types */
 173         double medium_time, pps;
 174
 175         /* TODO: account for airtime and answer no to tspec setup requests
 176          * when none left!! */
 177
 178         pps = (tspec->mean_data_rate / 8.0) / tspec->nominal_msdu_size;
 179         medium_time = (tspec->surplus_bandwidth_allowance / 8) * pps *
 180                 wme_frame_exchange_time(tspec->nominal_msdu_size,
 181                                         tspec->minimum_phy_rate, 0, 0);
 182         tspec->medium_time = medium_time * 1000000.0 / 32.0;
 183
 184         wme_send_action(hapd, mgmt->sa, tspec, WME_ACTION_CODE_SETUP_RESPONSE,
 185                         mgmt->u.action.u.wme_action.dialog_token,
 186                         WME_SETUP_RESPONSE_STATUS_ADMISSION_ACCEPTED);
 187 }
 188
 189
 190 void hostapd_wme_action(struct hostapd_data *hapd, struct ieee80211_mgmt *mgmt,
 191                         size_t len)
 192 {
 193         int action_code;
 194         int left = len - IEEE80211_HDRLEN - 4;
 195         u8 *pos = ((u8 *) mgmt) + IEEE80211_HDRLEN + 4;
 196         struct ieee802_11_elems elems;
 197         struct sta_info *sta = ap_get_sta(hapd, mgmt->sa);
 198
 199         /* check that the request comes from a valid station */
 200         if (!sta ||
 201             (sta->flags & (WLAN_STA_ASSOC | WLAN_STA_WME)) !=
 202             (WLAN_STA_ASSOC | WLAN_STA_WME)) {
 203                 hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
 204                                HOSTAPD_LEVEL_DEBUG,
 205                                "wme action received is not from associated wme"
 206                                " station");
 207                 /* TODO: respond with action frame refused status code */
 208                 return;
 209         }
 210
 211         /* extract the tspec info element */
 212         if (ieee802_11_parse_elems(hapd, pos, left, &elems, 1) == ParseFailed)
 213         {
 214                 hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
 215                                HOSTAPD_LEVEL_DEBUG,
 216                                "hostapd_wme_action - could not parse wme "
 217                                "action");
 218                 /* TODO: respond with action frame invalid parameters status
 219                  * code */
 220                 return;
 221         }
 222
 223         if (!elems.wme_tspec ||
 224             elems.wme_tspec_len != (sizeof(struct wme_tspec_info_element) - 2))
 225         {
 226                 hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
 227                                HOSTAPD_LEVEL_DEBUG,
 228                                "hostapd_wme_action - missing or wrong length "
 229                                "tspec");
 230                 /* TODO: respond with action frame invalid parameters status
 231                  * code */
 232                 return;
 233         }
 234
 235         /* TODO: check the request is for an AC with ACM set, if not, refuse
 236          * request */
 237
 238         action_code = mgmt->u.action.u.wme_action.action_code;
 239         switch (action_code) {
 240         case WME_ACTION_CODE_SETUP_REQUEST:
 241                 wme_setup_request(hapd, mgmt, (struct wme_tspec_info_element *)
 242                                   elems.wme_tspec, len);
 243                 return;
 244 #if 0
 245         /* TODO: needed for client implementation */
 246         case WME_ACTION_CODE_SETUP_RESPONSE:
 247                 wme_setup_request(hapd, mgmt, len);
 248                 return;
 249         /* TODO: handle station teardown requests */
 250         case WME_ACTION_CODE_TEARDOWN:
 251                 wme_teardown(hapd, mgmt, len);
 252                 return;
 253 #endif
 254         }
 255
 256         hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
 257                        HOSTAPD_LEVEL_DEBUG,
 258                        "hostapd_wme_action - unknown action code %d",
 259                        action_code);
 260 }