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
  24 static inline u8 wmm_aci_aifsn(int aifsn, int acm, int aci)
  25 {
  26         u8 ret;
  27         ret = (aifsn << WMM_AC_AIFNS_SHIFT) & WMM_AC_AIFSN_MASK;
  28         if (acm)
  29                 ret |= WMM_AC_ACM;
  30         ret |= (aci << WMM_AC_ACI_SHIFT) & WMM_AC_ACI_MASK;
  31         return ret;
  32 }
  33
  34
  35 static inline u8 wmm_ecw(int ecwmin, int ecwmax)
  36 {
  37         return ((ecwmin << WMM_AC_ECWMIN_SHIFT) & WMM_AC_ECWMIN_MASK) |
  38                 ((ecwmax << WMM_AC_ECWMAX_SHIFT) & WMM_AC_ECWMAX_MASK);
  39 }
  40
  41
  42 /*
  43  * Add WMM Parameter Element to Beacon, Probe Response, and (Re)Association
  44  * Response frames.
  45  */
  46 u8 * hostapd_eid_wmm(struct hostapd_data *hapd, u8 *eid)
  47 {
  48         u8 *pos = eid;
  49         struct wmm_parameter_element *wmm =
  50                 (struct wmm_parameter_element *) (pos + 2);
  51         int e;
  52
  53         if (!hapd->conf->wmm_enabled)
  54                 return eid;
  55         eid[0] = WLAN_EID_VENDOR_SPECIFIC;
  56         wmm->oui[0] = 0x00;
  57         wmm->oui[1] = 0x50;
  58         wmm->oui[2] = 0xf2;
  59         wmm->oui_type = WMM_OUI_TYPE;
  60         wmm->oui_subtype = WMM_OUI_SUBTYPE_PARAMETER_ELEMENT;
  61         wmm->version = WMM_VERSION;
  62         wmm->qos_info = hapd->parameter_set_count & 0xf;
  63
  64         if (hapd->conf->wmm_uapsd &&
  65             (hapd->iface->drv_flags & WPA_DRIVER_FLAGS_AP_UAPSD))
  66                 wmm->qos_info |= 0x80;
  67
  68         wmm->reserved = 0;
  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 /*
  91  * This function is called when a station sends an association request with
  92  * WMM info element. The function returns 1 on success or 0 on any error in WMM
  93  * element. eid does not include Element ID and Length octets.
  94  */
  95 int hostapd_eid_wmm_valid(struct hostapd_data *hapd, const u8 *eid, size_t len)
  96 {
  97         struct wmm_information_element *wmm;
  98
  99         wpa_hexdump(MSG_MSGDUMP, "WMM IE", eid, len);
 100
 101         if (len < sizeof(struct wmm_information_element)) {
 102                 wpa_printf(MSG_DEBUG, "Too short WMM IE (len=%lu)",
 103                            (unsigned long) len);
 104                 return 0;
 105         }
 106
 107         wmm = (struct wmm_information_element *) eid;
 108         wpa_printf(MSG_DEBUG, "Validating WMM IE: OUI %02x:%02x:%02x  "
 109                    "OUI type %d  OUI sub-type %d  version %d  QoS info 0x%x",
 110                    wmm->oui[0], wmm->oui[1], wmm->oui[2], wmm->oui_type,
 111                    wmm->oui_subtype, wmm->version, wmm->qos_info);
 112         if (wmm->oui_subtype != WMM_OUI_SUBTYPE_INFORMATION_ELEMENT ||
 113             wmm->version != WMM_VERSION) {
 114                 wpa_printf(MSG_DEBUG, "Unsupported WMM IE Subtype/Version");
 115                 return 0;
 116         }
 117
 118         return 1;
 119 }
 120
 121
 122 static void wmm_send_action(struct hostapd_data *hapd, const u8 *addr,
 123                             const struct wmm_tspec_element *tspec,
 124                             u8 action_code, u8 dialogue_token, u8 status_code)
 125 {
 126         u8 buf[256];
 127         struct ieee80211_mgmt *m = (struct ieee80211_mgmt *) buf;
 128         struct wmm_tspec_element *t = (struct wmm_tspec_element *)
 129                 m->u.action.u.wmm_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         os_memset(buf, 0, sizeof(buf));
 136         m->frame_control = IEEE80211_FC(WLAN_FC_TYPE_MGMT,
 137                                         WLAN_FC_STYPE_ACTION);
 138         os_memcpy(m->da, addr, ETH_ALEN);
 139         os_memcpy(m->sa, hapd->own_addr, ETH_ALEN);
 140         os_memcpy(m->bssid, hapd->own_addr, ETH_ALEN);
 141         m->u.action.category = WLAN_ACTION_WMM;
 142         m->u.action.u.wmm_action.action_code = action_code;
 143         m->u.action.u.wmm_action.dialog_token = dialogue_token;
 144         m->u.action.u.wmm_action.status_code = status_code;
 145         os_memcpy(t, tspec, sizeof(struct wmm_tspec_element));
 146         len = ((u8 *) (t + 1)) - buf;
 147
 148         if (hostapd_drv_send_mlme(hapd, m, len, 0) < 0)
 149                 wpa_printf(MSG_INFO, "wmm_send_action: send failed");
 150 }
 151
 152
 153 int wmm_process_tspec(struct wmm_tspec_element *tspec)
 154 {
 155         u64 medium_time;
 156         unsigned int pps, duration;
 157         unsigned int up, psb, dir, tid;
 158         u16 val, surplus;
 159
 160         up = (tspec->ts_info[1] >> 3) & 0x07;
 161         psb = (tspec->ts_info[1] >> 2) & 0x01;
 162         dir = (tspec->ts_info[0] >> 5) & 0x03;
 163         tid = (tspec->ts_info[0] >> 1) & 0x0f;
 164         wpa_printf(MSG_DEBUG, "WMM: TS Info: UP=%d PSB=%d Direction=%d TID=%d",
 165                    up, psb, dir, tid);
 166         val = le_to_host16(tspec->nominal_msdu_size);
 167         wpa_printf(MSG_DEBUG, "WMM: Nominal MSDU Size: %d%s",
 168                    val & 0x7fff, val & 0x8000 ? " (fixed)" : "");
 169         wpa_printf(MSG_DEBUG, "WMM: Mean Data Rate: %u bps",
 170                    le_to_host32(tspec->mean_data_rate));
 171         wpa_printf(MSG_DEBUG, "WMM: Minimum PHY Rate: %u bps",
 172                    le_to_host32(tspec->minimum_phy_rate));
 173         val = le_to_host16(tspec->surplus_bandwidth_allowance);
 174         wpa_printf(MSG_DEBUG, "WMM: Surplus Bandwidth Allowance: %u.%04u",
 175                    val >> 13, 10000 * (val & 0x1fff) / 0x2000);
 176
 177         val = le_to_host16(tspec->nominal_msdu_size);
 178         if (val == 0) {
 179                 wpa_printf(MSG_DEBUG, "WMM: Invalid Nominal MSDU Size (0)");
 180                 return WMM_ADDTS_STATUS_INVALID_PARAMETERS;
 181         }
 182         /* pps = Ceiling((Mean Data Rate / 8) / Nominal MSDU Size) */
 183         pps = ((le_to_host32(tspec->mean_data_rate) / 8) + val - 1) / val;
 184         wpa_printf(MSG_DEBUG, "WMM: Packets-per-second estimate for TSPEC: %d",
 185                    pps);
 186
 187         if (le_to_host32(tspec->minimum_phy_rate) < 1000000) {
 188                 wpa_printf(MSG_DEBUG, "WMM: Too small Minimum PHY Rate");
 189                 return WMM_ADDTS_STATUS_INVALID_PARAMETERS;
 190         }
 191
 192         duration = (le_to_host16(tspec->nominal_msdu_size) & 0x7fff) * 8 /
 193                 (le_to_host32(tspec->minimum_phy_rate) / 1000000) +
 194                 50 /* FIX: proper SIFS + ACK duration */;
 195
 196         /* unsigned binary number with an implicit binary point after the
 197          * leftmost 3 bits, i.e., 0x2000 = 1.0 */
 198         surplus = le_to_host16(tspec->surplus_bandwidth_allowance);
 199         if (surplus <= 0x2000) {
 200                 wpa_printf(MSG_DEBUG, "WMM: Surplus Bandwidth Allowance not "
 201                            "greater than unity");
 202                 return WMM_ADDTS_STATUS_INVALID_PARAMETERS;
 203         }
 204
 205         medium_time = (u64) surplus * pps * duration / 0x2000;
 206         wpa_printf(MSG_DEBUG, "WMM: Estimated medium time: %lu",
 207                    (unsigned long) medium_time);
 208
 209         /*
 210          * TODO: store list of granted (and still active) TSPECs and check
 211          * whether there is available medium time for this request. For now,
 212          * just refuse requests that would by themselves take very large
 213          * portion of the available bandwidth.
 214          */
 215         if (medium_time > 750000) {
 216                 wpa_printf(MSG_DEBUG, "WMM: Refuse TSPEC request for over "
 217                            "75%% of available bandwidth");
 218                 return WMM_ADDTS_STATUS_REFUSED;
 219         }
 220
 221         /* Convert to 32 microseconds per second unit */
 222         tspec->medium_time = host_to_le16(medium_time / 32);
 223
 224         return WMM_ADDTS_STATUS_ADMISSION_ACCEPTED;
 225 }
 226
 227
 228 static void wmm_addts_req(struct hostapd_data *hapd,
 229                           const struct ieee80211_mgmt *mgmt,
 230                           struct wmm_tspec_element *tspec, size_t len)
 231 {
 232         const u8 *end = ((const u8 *) mgmt) + len;
 233         int res;
 234
 235         if ((const u8 *) (tspec + 1) > end) {
 236                 wpa_printf(MSG_DEBUG, "WMM: TSPEC overflow in ADDTS Request");
 237                 return;
 238         }
 239
 240         wpa_printf(MSG_DEBUG, "WMM: ADDTS Request (Dialog Token %d) for TSPEC "
 241                    "from " MACSTR,
 242                    mgmt->u.action.u.wmm_action.dialog_token,
 243                    MAC2STR(mgmt->sa));
 244
 245         res = wmm_process_tspec(tspec);
 246         wpa_printf(MSG_DEBUG, "WMM: ADDTS processing result: %d", res);
 247
 248         wmm_send_action(hapd, mgmt->sa, tspec, WMM_ACTION_CODE_ADDTS_RESP,
 249                         mgmt->u.action.u.wmm_action.dialog_token, res);
 250 }
 251
 252
 253 void hostapd_wmm_action(struct hostapd_data *hapd,
 254                         const struct ieee80211_mgmt *mgmt, size_t len)
 255 {
 256         int action_code;
 257         int left = len - IEEE80211_HDRLEN - 4;
 258         const u8 *pos = ((const u8 *) mgmt) + IEEE80211_HDRLEN + 4;
 259         struct ieee802_11_elems elems;
 260         struct sta_info *sta = ap_get_sta(hapd, mgmt->sa);
 261
 262         /* check that the request comes from a valid station */
 263         if (!sta ||
 264             (sta->flags & (WLAN_STA_ASSOC | WLAN_STA_WMM)) !=
 265             (WLAN_STA_ASSOC | WLAN_STA_WMM)) {
 266                 hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
 267                                HOSTAPD_LEVEL_DEBUG,
 268                                "wmm action received is not from associated wmm"
 269                                " station");
 270                 /* TODO: respond with action frame refused status code */
 271                 return;
 272         }
 273
 274         if (left < 0)
 275                 return; /* not a valid WMM Action frame */
 276
 277         /* extract the tspec info element */
 278         if (ieee802_11_parse_elems(pos, left, &elems, 1) == ParseFailed) {
 279                 hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
 280                                HOSTAPD_LEVEL_DEBUG,
 281                                "hostapd_wmm_action - could not parse wmm "
 282                                "action");
 283                 /* TODO: respond with action frame invalid parameters status
 284                  * code */
 285                 return;
 286         }
 287
 288         if (!elems.wmm_tspec ||
 289             elems.wmm_tspec_len != (sizeof(struct wmm_tspec_element) - 2)) {
 290                 hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
 291                                HOSTAPD_LEVEL_DEBUG,
 292                                "hostapd_wmm_action - missing or wrong length "
 293                                "tspec");
 294                 /* TODO: respond with action frame invalid parameters status
 295                  * code */
 296                 return;
 297         }
 298
 299         /* TODO: check the request is for an AC with ACM set, if not, refuse
 300          * request */
 301
 302         action_code = mgmt->u.action.u.wmm_action.action_code;
 303         switch (action_code) {
 304         case WMM_ACTION_CODE_ADDTS_REQ:
 305                 wmm_addts_req(hapd, mgmt, (struct wmm_tspec_element *)
 306                               (elems.wmm_tspec - 2), len);
 307                 return;
 308 #if 0
 309         /* TODO: needed for client implementation */
 310         case WMM_ACTION_CODE_ADDTS_RESP:
 311                 wmm_setup_request(hapd, mgmt, len);
 312                 return;
 313         /* TODO: handle station teardown requests */
 314         case WMM_ACTION_CODE_DELTS:
 315                 wmm_teardown(hapd, mgmt, len);
 316                 return;
 317 #endif
 318         }
 319
 320         hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
 321                        HOSTAPD_LEVEL_DEBUG,
 322                        "hostapd_wmm_action - unknown action code %d",
 323                        action_code);
 324 }