contrib/wpa/src/ap/wmm.c

   1 /*
   2  * hostapd / WMM (Wi-Fi Multimedia)
   3  * Copyright 2002-2003, Instant802 Networks, Inc.
   4  * Copyright 2005-2006, Devicescape Software, Inc.
   5  * Copyright (c) 2009, Jouni Malinen <j@w1.fi>
   6  *
   7  * This software may be distributed under the terms of the BSD license.
   8  * See README for more details.
   9  */
  10
  11 #include "utils/includes.h"
  12
  13 #include "utils/common.h"
  14 #include "common/ieee802_11_defs.h"
  15 #include "common/ieee802_11_common.h"
  16 #include "hostapd.h"
  17 #include "ieee802_11.h"
  18 #include "sta_info.h"
  19 #include "ap_config.h"
  20 #include "ap_drv_ops.h"
  21 #include "wmm.h"
  22
  23 #ifndef MIN
  24 #define MIN(a, b) (((a) < (b)) ? (a) : (b))
  25 #endif
  26 #ifndef MAX
  27 #define MAX(a, b) (((a) > (b)) ? (a) : (b))
  28 #endif
  29
  30
  31 static inline u8 wmm_aci_aifsn(int aifsn, int acm, int aci)
  32 {
  33         u8 ret;
  34         ret = (aifsn << WMM_AC_AIFNS_SHIFT) & WMM_AC_AIFSN_MASK;
  35         if (acm)
  36                 ret |= WMM_AC_ACM;
  37         ret |= (aci << WMM_AC_ACI_SHIFT) & WMM_AC_ACI_MASK;
  38         return ret;
  39 }
  40
  41
  42 static inline u8 wmm_ecw(int ecwmin, int ecwmax)
  43 {
  44         return ((ecwmin << WMM_AC_ECWMIN_SHIFT) & WMM_AC_ECWMIN_MASK) |
  45                 ((ecwmax << WMM_AC_ECWMAX_SHIFT) & WMM_AC_ECWMAX_MASK);
  46 }
  47
  48
  49 static void
  50 wmm_set_regulatory_limit(const struct hostapd_wmm_ac_params *wmm_conf,
  51                          struct hostapd_wmm_ac_params *wmm,
  52                          const struct hostapd_wmm_rule *wmm_reg)
  53 {
  54         int ac;
  55
  56         for (ac = 0; ac < WMM_AC_NUM; ac++) {
  57                 wmm[ac].cwmin = MAX(wmm_conf[ac].cwmin, wmm_reg[ac].min_cwmin);
  58                 wmm[ac].cwmax = MAX(wmm_conf[ac].cwmax, wmm_reg[ac].min_cwmax);
  59                 wmm[ac].aifs = MAX(wmm_conf[ac].aifs, wmm_reg[ac].min_aifs);
  60                 wmm[ac].txop_limit =
  61                         MIN(wmm_conf[ac].txop_limit, wmm_reg[ac].max_txop);
  62                 wmm[ac].admission_control_mandatory =
  63                         wmm_conf[ac].admission_control_mandatory;
  64         }
  65 }
  66
  67
  68 /*
  69  * Calculate WMM regulatory limit if any.
  70  */
  71 static void wmm_calc_regulatory_limit(struct hostapd_data *hapd,
  72                                       struct hostapd_wmm_ac_params *acp)
  73 {
  74         struct hostapd_hw_modes *mode = hapd->iface->current_mode;
  75         int c;
  76
  77         os_memcpy(acp, hapd->iconf->wmm_ac_params,
  78                   sizeof(hapd->iconf->wmm_ac_params));
  79
  80         for (c = 0; mode && c < mode->num_channels; c++) {
  81                 struct hostapd_channel_data *chan = &mode->channels[c];
  82
  83                 if (chan->freq != hapd->iface->freq)
  84                         continue;
  85
  86                 if (chan->wmm_rules_valid)
  87                         wmm_set_regulatory_limit(hapd->iconf->wmm_ac_params,
  88                                                  acp, chan->wmm_rules);
  89                 break;
  90         }
  91
  92         /*
  93          * Check if we need to update set count. Since both were initialized to
  94          * zero we can compare the whole array in one shot.
  95          */
  96         if (os_memcmp(acp, hapd->iface->prev_wmm,
  97                       sizeof(hapd->iconf->wmm_ac_params)) != 0) {
  98                 os_memcpy(hapd->iface->prev_wmm, acp,
  99                           sizeof(hapd->iconf->wmm_ac_params));
 100                 hapd->parameter_set_count++;
 101         }
 102 }
 103
 104
 105 /*
 106  * Add WMM Parameter Element to Beacon, Probe Response, and (Re)Association
 107  * Response frames.
 108  */
 109 u8 * hostapd_eid_wmm(struct hostapd_data *hapd, u8 *eid)
 110 {
 111         u8 *pos = eid;
 112         struct wmm_parameter_element *wmm =
 113                 (struct wmm_parameter_element *) (pos + 2);
 114         struct hostapd_wmm_ac_params wmmp[WMM_AC_NUM] = { 0 };
 115         int e;
 116
 117         if (!hapd->conf->wmm_enabled)
 118                 return eid;
 119         wmm_calc_regulatory_limit(hapd, wmmp);
 120         eid[0] = WLAN_EID_VENDOR_SPECIFIC;
 121         wmm->oui[0] = 0x00;
 122         wmm->oui[1] = 0x50;
 123         wmm->oui[2] = 0xf2;
 124         wmm->oui_type = WMM_OUI_TYPE;
 125         wmm->oui_subtype = WMM_OUI_SUBTYPE_PARAMETER_ELEMENT;
 126         wmm->version = WMM_VERSION;
 127         wmm->qos_info = hapd->parameter_set_count & 0xf;
 128
 129         if (hapd->conf->wmm_uapsd &&
 130             (hapd->iface->drv_flags & WPA_DRIVER_FLAGS_AP_UAPSD))
 131                 wmm->qos_info |= 0x80;
 132
 133         wmm->reserved = 0;
 134
 135         /* fill in a parameter set record for each AC */
 136         for (e = 0; e < 4; e++) {
 137                 struct wmm_ac_parameter *ac = &wmm->ac[e];
 138                 struct hostapd_wmm_ac_params *acp = &wmmp[e];
 139
 140                 ac->aci_aifsn = wmm_aci_aifsn(acp->aifs,
 141                                               acp->admission_control_mandatory,
 142                                               e);
 143                 ac->cw = wmm_ecw(acp->cwmin, acp->cwmax);
 144                 ac->txop_limit = host_to_le16(acp->txop_limit);
 145         }
 146
 147         pos = (u8 *) (wmm + 1);
 148         eid[1] = pos - eid - 2; /* element length */
 149
 150         return pos;
 151 }
 152
 153
 154 /*
 155  * This function is called when a station sends an association request with
 156  * WMM info element. The function returns 1 on success or 0 on any error in WMM
 157  * element. eid does not include Element ID and Length octets.
 158  */
 159 int hostapd_eid_wmm_valid(struct hostapd_data *hapd, const u8 *eid, size_t len)
 160 {
 161         struct wmm_information_element *wmm;
 162
 163         wpa_hexdump(MSG_MSGDUMP, "WMM IE", eid, len);
 164
 165         if (len < sizeof(struct wmm_information_element)) {
 166                 wpa_printf(MSG_DEBUG, "Too short WMM IE (len=%lu)",
 167                            (unsigned long) len);
 168                 return 0;
 169         }
 170
 171         wmm = (struct wmm_information_element *) eid;
 172         wpa_printf(MSG_DEBUG, "Validating WMM IE: OUI %02x:%02x:%02x  "
 173                    "OUI type %d  OUI sub-type %d  version %d  QoS info 0x%x",
 174                    wmm->oui[0], wmm->oui[1], wmm->oui[2], wmm->oui_type,
 175                    wmm->oui_subtype, wmm->version, wmm->qos_info);
 176         if (wmm->oui_subtype != WMM_OUI_SUBTYPE_INFORMATION_ELEMENT ||
 177             wmm->version != WMM_VERSION) {
 178                 wpa_printf(MSG_DEBUG, "Unsupported WMM IE Subtype/Version");
 179                 return 0;
 180         }
 181
 182         return 1;
 183 }
 184
 185
 186 static void wmm_send_action(struct hostapd_data *hapd, const u8 *addr,
 187                             const struct wmm_tspec_element *tspec,
 188                             u8 action_code, u8 dialogue_token, u8 status_code)
 189 {
 190         u8 buf[256];
 191         struct ieee80211_mgmt *m = (struct ieee80211_mgmt *) buf;
 192         struct wmm_tspec_element *t = (struct wmm_tspec_element *)
 193                 m->u.action.u.wmm_action.variable;
 194         int len;
 195
 196         hostapd_logger(hapd, addr, HOSTAPD_MODULE_IEEE80211,
 197                        HOSTAPD_LEVEL_DEBUG,
 198                        "action response - reason %d", status_code);
 199         os_memset(buf, 0, sizeof(buf));
 200         m->frame_control = IEEE80211_FC(WLAN_FC_TYPE_MGMT,
 201                                         WLAN_FC_STYPE_ACTION);
 202         os_memcpy(m->da, addr, ETH_ALEN);
 203         os_memcpy(m->sa, hapd->own_addr, ETH_ALEN);
 204         os_memcpy(m->bssid, hapd->own_addr, ETH_ALEN);
 205         m->u.action.category = WLAN_ACTION_WMM;
 206         m->u.action.u.wmm_action.action_code = action_code;
 207         m->u.action.u.wmm_action.dialog_token = dialogue_token;
 208         m->u.action.u.wmm_action.status_code = status_code;
 209         os_memcpy(t, tspec, sizeof(struct wmm_tspec_element));
 210         len = ((u8 *) (t + 1)) - buf;
 211
 212         if (hostapd_drv_send_mlme(hapd, m, len, 0) < 0)
 213                 wpa_printf(MSG_INFO, "wmm_send_action: send failed");
 214 }
 215
 216
 217 int wmm_process_tspec(struct wmm_tspec_element *tspec)
 218 {
 219         u64 medium_time;
 220         unsigned int pps, duration;
 221         unsigned int up, psb, dir, tid;
 222         u16 val, surplus;
 223
 224         up = (tspec->ts_info[1] >> 3) & 0x07;
 225         psb = (tspec->ts_info[1] >> 2) & 0x01;
 226         dir = (tspec->ts_info[0] >> 5) & 0x03;
 227         tid = (tspec->ts_info[0] >> 1) & 0x0f;
 228         wpa_printf(MSG_DEBUG, "WMM: TS Info: UP=%d PSB=%d Direction=%d TID=%d",
 229                    up, psb, dir, tid);
 230         val = le_to_host16(tspec->nominal_msdu_size);
 231         wpa_printf(MSG_DEBUG, "WMM: Nominal MSDU Size: %d%s",
 232                    val & 0x7fff, val & 0x8000 ? " (fixed)" : "");
 233         wpa_printf(MSG_DEBUG, "WMM: Mean Data Rate: %u bps",
 234                    le_to_host32(tspec->mean_data_rate));
 235         wpa_printf(MSG_DEBUG, "WMM: Minimum PHY Rate: %u bps",
 236                    le_to_host32(tspec->minimum_phy_rate));
 237         val = le_to_host16(tspec->surplus_bandwidth_allowance);
 238         wpa_printf(MSG_DEBUG, "WMM: Surplus Bandwidth Allowance: %u.%04u",
 239                    val >> 13, 10000 * (val & 0x1fff) / 0x2000);
 240
 241         val = le_to_host16(tspec->nominal_msdu_size);
 242         if (val == 0) {
 243                 wpa_printf(MSG_DEBUG, "WMM: Invalid Nominal MSDU Size (0)");
 244                 return WMM_ADDTS_STATUS_INVALID_PARAMETERS;
 245         }
 246         /* pps = Ceiling((Mean Data Rate / 8) / Nominal MSDU Size) */
 247         pps = ((le_to_host32(tspec->mean_data_rate) / 8) + val - 1) / val;
 248         wpa_printf(MSG_DEBUG, "WMM: Packets-per-second estimate for TSPEC: %d",
 249                    pps);
 250
 251         if (le_to_host32(tspec->minimum_phy_rate) < 1000000) {
 252                 wpa_printf(MSG_DEBUG, "WMM: Too small Minimum PHY Rate");
 253                 return WMM_ADDTS_STATUS_INVALID_PARAMETERS;
 254         }
 255
 256         duration = (le_to_host16(tspec->nominal_msdu_size) & 0x7fff) * 8 /
 257                 (le_to_host32(tspec->minimum_phy_rate) / 1000000) +
 258                 50 /* FIX: proper SIFS + ACK duration */;
 259
 260         /* unsigned binary number with an implicit binary point after the
 261          * leftmost 3 bits, i.e., 0x2000 = 1.0 */
 262         surplus = le_to_host16(tspec->surplus_bandwidth_allowance);
 263         if (surplus <= 0x2000) {
 264                 wpa_printf(MSG_DEBUG, "WMM: Surplus Bandwidth Allowance not "
 265                            "greater than unity");
 266                 return WMM_ADDTS_STATUS_INVALID_PARAMETERS;
 267         }
 268
 269         medium_time = (u64) surplus * pps * duration / 0x2000;
 270         wpa_printf(MSG_DEBUG, "WMM: Estimated medium time: %lu",
 271                    (unsigned long) medium_time);
 272
 273         /*
 274          * TODO: store list of granted (and still active) TSPECs and check
 275          * whether there is available medium time for this request. For now,
 276          * just refuse requests that would by themselves take very large
 277          * portion of the available bandwidth.
 278          */
 279         if (medium_time > 750000) {
 280                 wpa_printf(MSG_DEBUG, "WMM: Refuse TSPEC request for over "
 281                            "75%% of available bandwidth");
 282                 return WMM_ADDTS_STATUS_REFUSED;
 283         }
 284
 285         /* Convert to 32 microseconds per second unit */
 286         tspec->medium_time = host_to_le16(medium_time / 32);
 287
 288         return WMM_ADDTS_STATUS_ADMISSION_ACCEPTED;
 289 }
 290
 291
 292 static void wmm_addts_req(struct hostapd_data *hapd,
 293                           const struct ieee80211_mgmt *mgmt,
 294                           struct wmm_tspec_element *tspec, size_t len)
 295 {
 296         const u8 *end = ((const u8 *) mgmt) + len;
 297         int res;
 298
 299         if ((const u8 *) (tspec + 1) > end) {
 300                 wpa_printf(MSG_DEBUG, "WMM: TSPEC overflow in ADDTS Request");
 301                 return;
 302         }
 303
 304         wpa_printf(MSG_DEBUG, "WMM: ADDTS Request (Dialog Token %d) for TSPEC "
 305                    "from " MACSTR,
 306                    mgmt->u.action.u.wmm_action.dialog_token,
 307                    MAC2STR(mgmt->sa));
 308
 309         res = wmm_process_tspec(tspec);
 310         wpa_printf(MSG_DEBUG, "WMM: ADDTS processing result: %d", res);
 311
 312         wmm_send_action(hapd, mgmt->sa, tspec, WMM_ACTION_CODE_ADDTS_RESP,
 313                         mgmt->u.action.u.wmm_action.dialog_token, res);
 314 }
 315
 316
 317 void hostapd_wmm_action(struct hostapd_data *hapd,
 318                         const struct ieee80211_mgmt *mgmt, size_t len)
 319 {
 320         int action_code;
 321         int left = len - IEEE80211_HDRLEN - 4;
 322         const u8 *pos = ((const u8 *) mgmt) + IEEE80211_HDRLEN + 4;
 323         struct ieee802_11_elems elems;
 324         struct sta_info *sta = ap_get_sta(hapd, mgmt->sa);
 325
 326         /* check that the request comes from a valid station */
 327         if (!sta ||
 328             (sta->flags & (WLAN_STA_ASSOC | WLAN_STA_WMM)) !=
 329             (WLAN_STA_ASSOC | WLAN_STA_WMM)) {
 330                 hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
 331                                HOSTAPD_LEVEL_DEBUG,
 332                                "wmm action received is not from associated wmm"
 333                                " station");
 334                 /* TODO: respond with action frame refused status code */
 335                 return;
 336         }
 337
 338         if (left < 0)
 339                 return; /* not a valid WMM Action frame */
 340
 341         /* extract the tspec info element */
 342         if (ieee802_11_parse_elems(pos, left, &elems, 1) == ParseFailed) {
 343                 hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
 344                                HOSTAPD_LEVEL_DEBUG,
 345                                "hostapd_wmm_action - could not parse wmm "
 346                                "action");
 347                 /* TODO: respond with action frame invalid parameters status
 348                  * code */
 349                 return;
 350         }
 351
 352         if (!elems.wmm_tspec ||
 353             elems.wmm_tspec_len != (sizeof(struct wmm_tspec_element) - 2)) {
 354                 hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
 355                                HOSTAPD_LEVEL_DEBUG,
 356                                "hostapd_wmm_action - missing or wrong length "
 357                                "tspec");
 358                 /* TODO: respond with action frame invalid parameters status
 359                  * code */
 360                 return;
 361         }
 362
 363         /* TODO: check the request is for an AC with ACM set, if not, refuse
 364          * request */
 365
 366         action_code = mgmt->u.action.u.wmm_action.action_code;
 367         switch (action_code) {
 368         case WMM_ACTION_CODE_ADDTS_REQ:
 369                 wmm_addts_req(hapd, mgmt, (struct wmm_tspec_element *)
 370                               (elems.wmm_tspec - 2), len);
 371                 return;
 372 #if 0
 373         /* TODO: needed for client implementation */
 374         case WMM_ACTION_CODE_ADDTS_RESP:
 375                 wmm_setup_request(hapd, mgmt, len);
 376                 return;
 377         /* TODO: handle station teardown requests */
 378         case WMM_ACTION_CODE_DELTS:
 379                 wmm_teardown(hapd, mgmt, len);
 380                 return;
 381 #endif
 382         }
 383
 384         hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
 385                        HOSTAPD_LEVEL_DEBUG,
 386                        "hostapd_wmm_action - unknown action code %d",
 387                        action_code);
 388 }