libeap/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 /* TODO: maintain separate sequence and fragment numbers for each AC
  25  * TODO: IGMP snooping to track which multicasts to forward - and use QOS-DATA
  26  * if only WMM stations are receiving a certain group */
  27
  28
  29 static inline u8 wmm_aci_aifsn(int aifsn, int acm, int aci)
  30 {
  31         u8 ret;
  32         ret = (aifsn << WMM_AC_AIFNS_SHIFT) & WMM_AC_AIFSN_MASK;
  33         if (acm)
  34                 ret |= WMM_AC_ACM;
  35         ret |= (aci << WMM_AC_ACI_SHIFT) & WMM_AC_ACI_MASK;
  36         return ret;
  37 }
  38
  39
  40 static inline u8 wmm_ecw(int ecwmin, int ecwmax)
  41 {
  42         return ((ecwmin << WMM_AC_ECWMIN_SHIFT) & WMM_AC_ECWMIN_MASK) |
  43                 ((ecwmax << WMM_AC_ECWMAX_SHIFT) & WMM_AC_ECWMAX_MASK);
  44 }
  45
  46
  47 /*
  48  * Add WMM Parameter Element to Beacon, Probe Response, and (Re)Association
  49  * Response frames.
  50  */
  51 u8 * hostapd_eid_wmm(struct hostapd_data *hapd, u8 *eid)
  52 {
  53         u8 *pos = eid;
  54         struct wmm_parameter_element *wmm =
  55                 (struct wmm_parameter_element *) (pos + 2);
  56         int e;
  57
  58         if (!hapd->conf->wmm_enabled)
  59                 return eid;
  60         eid[0] = WLAN_EID_VENDOR_SPECIFIC;
  61         wmm->oui[0] = 0x00;
  62         wmm->oui[1] = 0x50;
  63         wmm->oui[2] = 0xf2;
  64         wmm->oui_type = WMM_OUI_TYPE;
  65         wmm->oui_subtype = WMM_OUI_SUBTYPE_PARAMETER_ELEMENT;
  66         wmm->version = WMM_VERSION;
  67         wmm->qos_info = hapd->parameter_set_count & 0xf;
  68
  69         if (hapd->conf->wmm_uapsd &&
  70             (hapd->iface->drv_flags & WPA_DRIVER_FLAGS_AP_UAPSD))
  71                 wmm->qos_info |= 0x80;
  72
  73         wmm->reserved = 0;
  74
  75         /* fill in a parameter set record for each AC */
  76         for (e = 0; e < 4; e++) {
  77                 struct wmm_ac_parameter *ac = &wmm->ac[e];
  78                 struct hostapd_wmm_ac_params *acp =
  79                         &hapd->iconf->wmm_ac_params[e];
  80
  81                 ac->aci_aifsn = wmm_aci_aifsn(acp->aifs,
  82                                               acp->admission_control_mandatory,
  83                                               e);
  84                 ac->cw = wmm_ecw(acp->cwmin, acp->cwmax);
  85                 ac->txop_limit = host_to_le16(acp->txop_limit);
  86         }
  87
  88         pos = (u8 *) (wmm + 1);
  89         eid[1] = pos - eid - 2; /* element length */
  90
  91         return pos;
  92 }
  93
  94
  95 /*
  96  * This function is called when a station sends an association request with
  97  * WMM info element. The function returns 1 on success or 0 on any error in WMM
  98  * element. eid does not include Element ID and Length octets.
  99  */
 100 int hostapd_eid_wmm_valid(struct hostapd_data *hapd, const u8 *eid, size_t len)
 101 {
 102         struct wmm_information_element *wmm;
 103
 104         wpa_hexdump(MSG_MSGDUMP, "WMM IE", eid, len);
 105
 106         if (len < sizeof(struct wmm_information_element)) {
 107                 wpa_printf(MSG_DEBUG, "Too short WMM IE (len=%lu)",
 108                            (unsigned long) len);
 109                 return 0;
 110         }
 111
 112         wmm = (struct wmm_information_element *) eid;
 113         wpa_printf(MSG_DEBUG, "Validating WMM IE: OUI %02x:%02x:%02x  "
 114                    "OUI type %d  OUI sub-type %d  version %d  QoS info 0x%x",
 115                    wmm->oui[0], wmm->oui[1], wmm->oui[2], wmm->oui_type,
 116                    wmm->oui_subtype, wmm->version, wmm->qos_info);
 117         if (wmm->oui_subtype != WMM_OUI_SUBTYPE_INFORMATION_ELEMENT ||
 118             wmm->version != WMM_VERSION) {
 119                 wpa_printf(MSG_DEBUG, "Unsupported WMM IE Subtype/Version");
 120                 return 0;
 121         }
 122
 123         return 1;
 124 }
 125
 126
 127 static void wmm_send_action(struct hostapd_data *hapd, const u8 *addr,
 128                             const struct wmm_tspec_element *tspec,
 129                             u8 action_code, u8 dialogue_token, u8 status_code)
 130 {
 131         u8 buf[256];
 132         struct ieee80211_mgmt *m = (struct ieee80211_mgmt *) buf;
 133         struct wmm_tspec_element *t = (struct wmm_tspec_element *)
 134                 m->u.action.u.wmm_action.variable;
 135         int len;
 136
 137         hostapd_logger(hapd, addr, HOSTAPD_MODULE_IEEE80211,
 138                        HOSTAPD_LEVEL_DEBUG,
 139                        "action response - reason %d", status_code);
 140         os_memset(buf, 0, sizeof(buf));
 141         m->frame_control = IEEE80211_FC(WLAN_FC_TYPE_MGMT,
 142                                         WLAN_FC_STYPE_ACTION);
 143         os_memcpy(m->da, addr, ETH_ALEN);
 144         os_memcpy(m->sa, hapd->own_addr, ETH_ALEN);
 145         os_memcpy(m->bssid, hapd->own_addr, ETH_ALEN);
 146         m->u.action.category = WLAN_ACTION_WMM;
 147         m->u.action.u.wmm_action.action_code = action_code;
 148         m->u.action.u.wmm_action.dialog_token = dialogue_token;
 149         m->u.action.u.wmm_action.status_code = status_code;
 150         os_memcpy(t, tspec, sizeof(struct wmm_tspec_element));
 151         len = ((u8 *) (t + 1)) - buf;
 152
 153         if (hostapd_drv_send_mlme(hapd, m, len, 0) < 0)
 154                 wpa_printf(MSG_INFO, "wmm_send_action: send failed");
 155 }
 156
 157
 158 int wmm_process_tspec(struct wmm_tspec_element *tspec)
 159 {
 160         int medium_time, pps, duration;
 161         int up, psb, dir, tid;
 162         u16 val, surplus;
 163
 164         up = (tspec->ts_info[1] >> 3) & 0x07;
 165         psb = (tspec->ts_info[1] >> 2) & 0x01;
 166         dir = (tspec->ts_info[0] >> 5) & 0x03;
 167         tid = (tspec->ts_info[0] >> 1) & 0x0f;
 168         wpa_printf(MSG_DEBUG, "WMM: TS Info: UP=%d PSB=%d Direction=%d TID=%d",
 169                    up, psb, dir, tid);
 170         val = le_to_host16(tspec->nominal_msdu_size);
 171         wpa_printf(MSG_DEBUG, "WMM: Nominal MSDU Size: %d%s",
 172                    val & 0x7fff, val & 0x8000 ? " (fixed)" : "");
 173         wpa_printf(MSG_DEBUG, "WMM: Mean Data Rate: %u bps",
 174                    le_to_host32(tspec->mean_data_rate));
 175         wpa_printf(MSG_DEBUG, "WMM: Minimum PHY Rate: %u bps",
 176                    le_to_host32(tspec->minimum_phy_rate));
 177         val = le_to_host16(tspec->surplus_bandwidth_allowance);
 178         wpa_printf(MSG_DEBUG, "WMM: Surplus Bandwidth Allowance: %u.%04u",
 179                    val >> 13, 10000 * (val & 0x1fff) / 0x2000);
 180
 181         val = le_to_host16(tspec->nominal_msdu_size);
 182         if (val == 0) {
 183                 wpa_printf(MSG_DEBUG, "WMM: Invalid Nominal MSDU Size (0)");
 184                 return WMM_ADDTS_STATUS_INVALID_PARAMETERS;
 185         }
 186         /* pps = Ceiling((Mean Data Rate / 8) / Nominal MSDU Size) */
 187         pps = ((le_to_host32(tspec->mean_data_rate) / 8) + val - 1) / val;
 188         wpa_printf(MSG_DEBUG, "WMM: Packets-per-second estimate for TSPEC: %d",
 189                    pps);
 190
 191         if (le_to_host32(tspec->minimum_phy_rate) < 1000000) {
 192                 wpa_printf(MSG_DEBUG, "WMM: Too small Minimum PHY Rate");
 193                 return WMM_ADDTS_STATUS_INVALID_PARAMETERS;
 194         }
 195
 196         duration = (le_to_host16(tspec->nominal_msdu_size) & 0x7fff) * 8 /
 197                 (le_to_host32(tspec->minimum_phy_rate) / 1000000) +
 198                 50 /* FIX: proper SIFS + ACK duration */;
 199
 200         /* unsigned binary number with an implicit binary point after the
 201          * leftmost 3 bits, i.e., 0x2000 = 1.0 */
 202         surplus = le_to_host16(tspec->surplus_bandwidth_allowance);
 203         if (surplus <= 0x2000) {
 204                 wpa_printf(MSG_DEBUG, "WMM: Surplus Bandwidth Allowance not "
 205                            "greater than unity");
 206                 return WMM_ADDTS_STATUS_INVALID_PARAMETERS;
 207         }
 208
 209         medium_time = surplus * pps * duration / 0x2000;
 210         wpa_printf(MSG_DEBUG, "WMM: Estimated medium time: %u", medium_time);
 211
 212         /*
 213          * TODO: store list of granted (and still active) TSPECs and check
 214          * whether there is available medium time for this request. For now,
 215          * just refuse requests that would by themselves take very large
 216          * portion of the available bandwidth.
 217          */
 218         if (medium_time > 750000) {
 219                 wpa_printf(MSG_DEBUG, "WMM: Refuse TSPEC request for over "
 220                            "75%% of available bandwidth");
 221                 return WMM_ADDTS_STATUS_REFUSED;
 222         }
 223
 224         /* Convert to 32 microseconds per second unit */
 225         tspec->medium_time = host_to_le16(medium_time / 32);
 226
 227         return WMM_ADDTS_STATUS_ADMISSION_ACCEPTED;
 228 }
 229
 230
 231 static void wmm_addts_req(struct hostapd_data *hapd,
 232                           const struct ieee80211_mgmt *mgmt,
 233                           struct wmm_tspec_element *tspec, size_t len)
 234 {
 235         const u8 *end = ((const u8 *) mgmt) + len;
 236         int res;
 237
 238         if ((const u8 *) (tspec + 1) > end) {
 239                 wpa_printf(MSG_DEBUG, "WMM: TSPEC overflow in ADDTS Request");
 240                 return;
 241         }
 242
 243         wpa_printf(MSG_DEBUG, "WMM: ADDTS Request (Dialog Token %d) for TSPEC "
 244                    "from " MACSTR,
 245                    mgmt->u.action.u.wmm_action.dialog_token,
 246                    MAC2STR(mgmt->sa));
 247
 248         res = wmm_process_tspec(tspec);
 249         wpa_printf(MSG_DEBUG, "WMM: ADDTS processing result: %d", res);
 250
 251         wmm_send_action(hapd, mgmt->sa, tspec, WMM_ACTION_CODE_ADDTS_RESP,
 252                         mgmt->u.action.u.wmm_action.dialog_token, res);
 253 }
 254
 255
 256 void hostapd_wmm_action(struct hostapd_data *hapd,
 257                         const struct ieee80211_mgmt *mgmt, size_t len)
 258 {
 259         int action_code;
 260         int left = len - IEEE80211_HDRLEN - 4;
 261         const u8 *pos = ((const u8 *) mgmt) + IEEE80211_HDRLEN + 4;
 262         struct ieee802_11_elems elems;
 263         struct sta_info *sta = ap_get_sta(hapd, mgmt->sa);
 264
 265         /* check that the request comes from a valid station */
 266         if (!sta ||
 267             (sta->flags & (WLAN_STA_ASSOC | WLAN_STA_WMM)) !=
 268             (WLAN_STA_ASSOC | WLAN_STA_WMM)) {
 269                 hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
 270                                HOSTAPD_LEVEL_DEBUG,
 271                                "wmm action received is not from associated wmm"
 272                                " station");
 273                 /* TODO: respond with action frame refused status code */
 274                 return;
 275         }
 276
 277         if (left < 0)
 278                 return; /* not a valid WMM Action frame */
 279
 280         /* extract the tspec info element */
 281         if (ieee802_11_parse_elems(pos, left, &elems, 1) == ParseFailed) {
 282                 hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
 283                                HOSTAPD_LEVEL_DEBUG,
 284                                "hostapd_wmm_action - could not parse wmm "
 285                                "action");
 286                 /* TODO: respond with action frame invalid parameters status
 287                  * code */
 288                 return;
 289         }
 290
 291         if (!elems.wmm_tspec ||
 292             elems.wmm_tspec_len != (sizeof(struct wmm_tspec_element) - 2)) {
 293                 hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
 294                                HOSTAPD_LEVEL_DEBUG,
 295                                "hostapd_wmm_action - missing or wrong length "
 296                                "tspec");
 297                 /* TODO: respond with action frame invalid parameters status
 298                  * code */
 299                 return;
 300         }
 301
 302         /* TODO: check the request is for an AC with ACM set, if not, refuse
 303          * request */
 304
 305         action_code = mgmt->u.action.u.wmm_action.action_code;
 306         switch (action_code) {
 307         case WMM_ACTION_CODE_ADDTS_REQ:
 308                 wmm_addts_req(hapd, mgmt, (struct wmm_tspec_element *)
 309                               (elems.wmm_tspec - 2), len);
 310                 return;
 311 #if 0
 312         /* TODO: needed for client implementation */
 313         case WMM_ACTION_CODE_ADDTS_RESP:
 314                 wmm_setup_request(hapd, mgmt, len);
 315                 return;
 316         /* TODO: handle station teardown requests */
 317         case WMM_ACTION_CODE_DELTS:
 318                 wmm_teardown(hapd, mgmt, len);
 319                 return;
 320 #endif
 321         }
 322
 323         hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
 324                        HOSTAPD_LEVEL_DEBUG,
 325                        "hostapd_wmm_action - unknown action code %d",
 326                        action_code);
 327 }