contrib/hostapd/hostapd/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 WMM stations are receiving a certain group */
  28
  29
  30 static inline u8 wmm_aci_aifsn(int aifsn, int acm, int aci)
  31 {
  32         u8 ret;
  33         ret = (aifsn << WMM_AC_AIFNS_SHIFT) & WMM_AC_AIFSN_MASK;
  34         if (acm)
  35                 ret |= WMM_AC_ACM;
  36         ret |= (aci << WMM_AC_ACI_SHIFT) & WMM_AC_ACI_MASK;
  37         return ret;
  38 }
  39
  40
  41 static inline u8 wmm_ecw(int ecwmin, int ecwmax)
  42 {
  43         return ((ecwmin << WMM_AC_ECWMIN_SHIFT) & WMM_AC_ECWMIN_MASK) |
  44                 ((ecwmax << WMM_AC_ECWMAX_SHIFT) & WMM_AC_ECWMAX_MASK);
  45 }
  46
  47
  48 /*
  49  * Add WMM Parameter Element to Beacon, Probe Response, and (Re)Association
  50  * Response frames.
  51  */
  52 u8 * hostapd_eid_wmm(struct hostapd_data *hapd, u8 *eid)
  53 {
  54         u8 *pos = eid;
  55         struct wmm_parameter_element *wmm =
  56                 (struct wmm_parameter_element *) (pos + 2);
  57         int e;
  58
  59         if (!hapd->conf->wmm_enabled)
  60                 return eid;
  61         eid[0] = WLAN_EID_VENDOR_SPECIFIC;
  62         wmm->oui[0] = 0x00;
  63         wmm->oui[1] = 0x50;
  64         wmm->oui[2] = 0xf2;
  65         wmm->oui_type = WMM_OUI_TYPE;
  66         wmm->oui_subtype = WMM_OUI_SUBTYPE_PARAMETER_ELEMENT;
  67         wmm->version = WMM_VERSION;
  68         wmm->qos_info = hapd->parameter_set_count & 0xf;
  69
  70         /* fill in a parameter set record for each AC */
  71         for (e = 0; e < 4; e++) {
  72                 struct wmm_ac_parameter *ac = &wmm->ac[e];
  73                 struct hostapd_wmm_ac_params *acp =
  74                         &hapd->iconf->wmm_ac_params[e];
  75
  76                 ac->aci_aifsn = wmm_aci_aifsn(acp->aifs,
  77                                               acp->admission_control_mandatory,
  78                                               e);
  79                 ac->cw = wmm_ecw(acp->cwmin, acp->cwmax);
  80                 ac->txop_limit = host_to_le16(acp->txop_limit);
  81         }
  82
  83         pos = (u8 *) (wmm + 1);
  84         eid[1] = pos - eid - 2; /* element length */
  85
  86         return pos;
  87 }
  88
  89
  90 /* This function is called when a station sends an association request with
  91  * WMM info element. The function returns zero on success or non-zero on any
  92  * error in WMM element. eid does not include Element ID and Length octets. */
  93 int hostapd_eid_wmm_valid(struct hostapd_data *hapd, u8 *eid, size_t len)
  94 {
  95         struct wmm_information_element *wmm;
  96
  97         wpa_hexdump(MSG_MSGDUMP, "WMM IE", eid, len);
  98
  99         if (len < sizeof(struct wmm_information_element)) {
 100                 wpa_printf(MSG_DEBUG, "Too short WMM IE (len=%lu)",
 101                            (unsigned long) len);
 102                 return -1;
 103         }
 104
 105         wmm = (struct wmm_information_element *) eid;
 106         wpa_printf(MSG_DEBUG, "Validating WMM IE: OUI %02x:%02x:%02x  "
 107                    "OUI type %d  OUI sub-type %d  version %d  QoS info 0x%x",
 108                    wmm->oui[0], wmm->oui[1], wmm->oui[2], wmm->oui_type,
 109                    wmm->oui_subtype, wmm->version, wmm->qos_info);
 110         if (wmm->oui_subtype != WMM_OUI_SUBTYPE_INFORMATION_ELEMENT ||
 111             wmm->version != WMM_VERSION) {
 112                 wpa_printf(MSG_DEBUG, "Unsupported WMM IE Subtype/Version");
 113                 return -1;
 114         }
 115
 116         return 0;
 117 }
 118
 119
 120 /* This function is called when a station sends an ACK frame for an AssocResp
 121  * frame (status=success) and the matching AssocReq contained a WMM element.
 122  */
 123 int hostapd_wmm_sta_config(struct hostapd_data *hapd, struct sta_info *sta)
 124 {
 125         /* update kernel STA data for WMM related items (WLAN_STA_WPA flag) */
 126         if (sta->flags & WLAN_STA_WMM)
 127                 hostapd_sta_set_flags(hapd, sta->addr, sta->flags,
 128                                       WLAN_STA_WMM, ~0);
 129         else
 130                 hostapd_sta_set_flags(hapd, sta->addr, sta->flags,
 131                                       0, ~WLAN_STA_WMM);
 132
 133         return 0;
 134 }
 135
 136
 137 static void wmm_send_action(struct hostapd_data *hapd, const u8 *addr,
 138                             const struct wmm_tspec_element *tspec,
 139                             u8 action_code, u8 dialogue_token, u8 status_code)
 140 {
 141         u8 buf[256];
 142         struct ieee80211_mgmt *m = (struct ieee80211_mgmt *) buf;
 143         struct wmm_tspec_element *t = (struct wmm_tspec_element *)
 144                 m->u.action.u.wmm_action.variable;
 145         int len;
 146
 147         hostapd_logger(hapd, addr, HOSTAPD_MODULE_IEEE80211,
 148                        HOSTAPD_LEVEL_DEBUG,
 149                        "action response - reason %d", status_code);
 150         os_memset(buf, 0, sizeof(buf));
 151         m->frame_control = IEEE80211_FC(WLAN_FC_TYPE_MGMT,
 152                                         WLAN_FC_STYPE_ACTION);
 153         os_memcpy(m->da, addr, ETH_ALEN);
 154         os_memcpy(m->sa, hapd->own_addr, ETH_ALEN);
 155         os_memcpy(m->bssid, hapd->own_addr, ETH_ALEN);
 156         m->u.action.category = WLAN_ACTION_WMM;
 157         m->u.action.u.wmm_action.action_code = action_code;
 158         m->u.action.u.wmm_action.dialog_token = dialogue_token;
 159         m->u.action.u.wmm_action.status_code = status_code;
 160         os_memcpy(t, tspec, sizeof(struct wmm_tspec_element));
 161         len = ((u8 *) (t + 1)) - buf;
 162
 163         if (hostapd_send_mgmt_frame(hapd, m, len, 0) < 0)
 164                 perror("wmm_send_action: send");
 165 }
 166
 167
 168 static void wmm_addts_req(struct hostapd_data *hapd,
 169                           struct ieee80211_mgmt *mgmt,
 170                           struct wmm_tspec_element *tspec, size_t len)
 171 {
 172         u8 *end = ((u8 *) mgmt) + len;
 173         int medium_time, pps, duration;
 174         int up, psb, dir, tid;
 175         u16 val, surplus;
 176
 177         if ((u8 *) (tspec + 1) > end) {
 178                 wpa_printf(MSG_DEBUG, "WMM: TSPEC overflow in ADDTS Request");
 179                 return;
 180         }
 181
 182         wpa_printf(MSG_DEBUG, "WMM: ADDTS Request (Dialog Token %d) for TSPEC "
 183                    "from " MACSTR,
 184                    mgmt->u.action.u.wmm_action.dialog_token,
 185                    MAC2STR(mgmt->sa));
 186
 187         up = (tspec->ts_info[1] >> 3) & 0x07;
 188         psb = (tspec->ts_info[1] >> 2) & 0x01;
 189         dir = (tspec->ts_info[0] >> 5) & 0x03;
 190         tid = (tspec->ts_info[0] >> 1) & 0x0f;
 191         wpa_printf(MSG_DEBUG, "WMM: TS Info: UP=%d PSB=%d Direction=%d TID=%d",
 192                    up, psb, dir, tid);
 193         val = le_to_host16(tspec->nominal_msdu_size);
 194         wpa_printf(MSG_DEBUG, "WMM: Nominal MSDU Size: %d%s",
 195                    val & 0x7fff, val & 0x8000 ? " (fixed)" : "");
 196         wpa_printf(MSG_DEBUG, "WMM: Mean Data Rate: %u bps",
 197                    le_to_host32(tspec->mean_data_rate));
 198         wpa_printf(MSG_DEBUG, "WMM: Minimum PHY Rate: %u bps",
 199                    le_to_host32(tspec->minimum_phy_rate));
 200         val = le_to_host16(tspec->surplus_bandwidth_allowance);
 201         wpa_printf(MSG_DEBUG, "WMM: Surplus Bandwidth Allowance: %u.%04u",
 202                    val >> 13, 10000 * (val & 0x1fff) / 0x2000);
 203
 204         val = le_to_host16(tspec->nominal_msdu_size);
 205         if (val == 0) {
 206                 wpa_printf(MSG_DEBUG, "WMM: Invalid Nominal MSDU Size (0)");
 207                 goto invalid;
 208         }
 209         /* pps = Ceiling((Mean Data Rate / 8) / Nominal MSDU Size) */
 210         pps = ((le_to_host32(tspec->mean_data_rate) / 8) + val - 1) / val;
 211         wpa_printf(MSG_DEBUG, "WMM: Packets-per-second estimate for TSPEC: %d",
 212                    pps);
 213
 214         if (le_to_host32(tspec->minimum_phy_rate) < 1000000) {
 215                 wpa_printf(MSG_DEBUG, "WMM: Too small Minimum PHY Rate");
 216                 goto invalid;
 217         }
 218
 219         duration = (le_to_host16(tspec->nominal_msdu_size) & 0x7fff) * 8 /
 220                 (le_to_host32(tspec->minimum_phy_rate) / 1000000) +
 221                 50 /* FIX: proper SIFS + ACK duration */;
 222
 223         /* unsigned binary number with an implicit binary point after the
 224          * leftmost 3 bits, i.e., 0x2000 = 1.0 */
 225         surplus = le_to_host16(tspec->surplus_bandwidth_allowance);
 226         if (surplus <= 0x2000) {
 227                 wpa_printf(MSG_DEBUG, "WMM: Surplus Bandwidth Allowance not "
 228                            "greater than unity");
 229                 goto invalid;
 230         }
 231
 232         medium_time = surplus * pps * duration / 0x2000;
 233         wpa_printf(MSG_DEBUG, "WMM: Estimated medium time: %u", medium_time);
 234
 235         /*
 236          * TODO: store list of granted (and still active) TSPECs and check
 237          * whether there is available medium time for this request. For now,
 238          * just refuse requests that would by themselves take very large
 239          * portion of the available bandwidth.
 240          */
 241         if (medium_time > 750000) {
 242                 wpa_printf(MSG_DEBUG, "WMM: Refuse TSPEC request for over "
 243                            "75%% of available bandwidth");
 244                 wmm_send_action(hapd, mgmt->sa, tspec,
 245                                 WMM_ACTION_CODE_ADDTS_RESP,
 246                                 mgmt->u.action.u.wmm_action.dialog_token,
 247                                 WMM_ADDTS_STATUS_REFUSED);
 248                 return;
 249         }
 250
 251         /* Convert to 32 microseconds per second unit */
 252         tspec->medium_time = host_to_le16(medium_time / 32);
 253
 254         wmm_send_action(hapd, mgmt->sa, tspec, WMM_ACTION_CODE_ADDTS_RESP,
 255                         mgmt->u.action.u.wmm_action.dialog_token,
 256                         WMM_ADDTS_STATUS_ADMISSION_ACCEPTED);
 257         return;
 258
 259 invalid:
 260         wmm_send_action(hapd, mgmt->sa, tspec,
 261                         WMM_ACTION_CODE_ADDTS_RESP,
 262                         mgmt->u.action.u.wmm_action.dialog_token,
 263                         WMM_ADDTS_STATUS_INVALID_PARAMETERS);
 264 }
 265
 266
 267 void hostapd_wmm_action(struct hostapd_data *hapd, struct ieee80211_mgmt *mgmt,
 268                         size_t len)
 269 {
 270         int action_code;
 271         int left = len - IEEE80211_HDRLEN - 4;
 272         u8 *pos = ((u8 *) mgmt) + IEEE80211_HDRLEN + 4;
 273         struct ieee802_11_elems elems;
 274         struct sta_info *sta = ap_get_sta(hapd, mgmt->sa);
 275
 276         /* check that the request comes from a valid station */
 277         if (!sta ||
 278             (sta->flags & (WLAN_STA_ASSOC | WLAN_STA_WMM)) !=
 279             (WLAN_STA_ASSOC | WLAN_STA_WMM)) {
 280                 hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
 281                                HOSTAPD_LEVEL_DEBUG,
 282                                "wmm action received is not from associated wmm"
 283                                " station");
 284                 /* TODO: respond with action frame refused status code */
 285                 return;
 286         }
 287
 288         /* extract the tspec info element */
 289         if (ieee802_11_parse_elems(pos, left, &elems, 1) == ParseFailed) {
 290                 hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
 291                                HOSTAPD_LEVEL_DEBUG,
 292                                "hostapd_wmm_action - could not parse wmm "
 293                                "action");
 294                 /* TODO: respond with action frame invalid parameters status
 295                  * code */
 296                 return;
 297         }
 298
 299         if (!elems.wmm_tspec ||
 300             elems.wmm_tspec_len != (sizeof(struct wmm_tspec_element) - 2)) {
 301                 hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
 302                                HOSTAPD_LEVEL_DEBUG,
 303                                "hostapd_wmm_action - missing or wrong length "
 304                                "tspec");
 305                 /* TODO: respond with action frame invalid parameters status
 306                  * code */
 307                 return;
 308         }
 309
 310         /* TODO: check the request is for an AC with ACM set, if not, refuse
 311          * request */
 312
 313         action_code = mgmt->u.action.u.wmm_action.action_code;
 314         switch (action_code) {
 315         case WMM_ACTION_CODE_ADDTS_REQ:
 316                 wmm_addts_req(hapd, mgmt, (struct wmm_tspec_element *)
 317                               (elems.wmm_tspec - 2), len);
 318                 return;
 319 #if 0
 320         /* TODO: needed for client implementation */
 321         case WMM_ACTION_CODE_ADDTS_RESP:
 322                 wmm_setup_request(hapd, mgmt, len);
 323                 return;
 324         /* TODO: handle station teardown requests */
 325         case WMM_ACTION_CODE_DELTS:
 326                 wmm_teardown(hapd, mgmt, len);
 327                 return;
 328 #endif
 329         }
 330
 331         hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
 332                        HOSTAPD_LEVEL_DEBUG,
 333                        "hostapd_wmm_action - unknown action code %d",
 334                        action_code);
 335 }