wmm.c revision cce06667447b5aec83452adb0c15100ada531095
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 program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 * 11 * Alternatively, this software may be distributed under the terms of BSD 12 * license. 13 * 14 * See README and COPYING for more details. 15 */ 16 17#include "utils/includes.h" 18 19#include "utils/common.h" 20#include "common/ieee802_11_defs.h" 21#include "common/ieee802_11_common.h" 22#include "hostapd.h" 23#include "ieee802_11.h" 24#include "sta_info.h" 25#include "ap_config.h" 26#include "ap_drv_ops.h" 27#include "wmm.h" 28 29 30/* TODO: maintain separate sequence and fragment numbers for each AC 31 * TODO: IGMP snooping to track which multicasts to forward - and use QOS-DATA 32 * if only WMM stations are receiving a certain group */ 33 34 35static inline u8 wmm_aci_aifsn(int aifsn, int acm, int aci) 36{ 37 u8 ret; 38 ret = (aifsn << WMM_AC_AIFNS_SHIFT) & WMM_AC_AIFSN_MASK; 39 if (acm) 40 ret |= WMM_AC_ACM; 41 ret |= (aci << WMM_AC_ACI_SHIFT) & WMM_AC_ACI_MASK; 42 return ret; 43} 44 45 46static inline u8 wmm_ecw(int ecwmin, int ecwmax) 47{ 48 return ((ecwmin << WMM_AC_ECWMIN_SHIFT) & WMM_AC_ECWMIN_MASK) | 49 ((ecwmax << WMM_AC_ECWMAX_SHIFT) & WMM_AC_ECWMAX_MASK); 50} 51 52 53/* 54 * Add WMM Parameter Element to Beacon, Probe Response, and (Re)Association 55 * Response frames. 56 */ 57u8 * hostapd_eid_wmm(struct hostapd_data *hapd, u8 *eid) 58{ 59 u8 *pos = eid; 60 struct wmm_parameter_element *wmm = 61 (struct wmm_parameter_element *) (pos + 2); 62 int e; 63 64 if (!hapd->conf->wmm_enabled) 65 return eid; 66 eid[0] = WLAN_EID_VENDOR_SPECIFIC; 67 wmm->oui[0] = 0x00; 68 wmm->oui[1] = 0x50; 69 wmm->oui[2] = 0xf2; 70 wmm->oui_type = WMM_OUI_TYPE; 71 wmm->oui_subtype = WMM_OUI_SUBTYPE_PARAMETER_ELEMENT; 72 wmm->version = WMM_VERSION; 73 wmm->qos_info = hapd->parameter_set_count & 0xf; 74 75 if (hapd->conf->wmm_uapsd && 76 (hapd->iface->drv_flags & WPA_DRIVER_FLAGS_AP_UAPSD)) 77 wmm->qos_info |= 0x80; 78 79 wmm->reserved = 0; 80 81 /* fill in a parameter set record for each AC */ 82 for (e = 0; e < 4; e++) { 83 struct wmm_ac_parameter *ac = &wmm->ac[e]; 84 struct hostapd_wmm_ac_params *acp = 85 &hapd->iconf->wmm_ac_params[e]; 86 87 ac->aci_aifsn = wmm_aci_aifsn(acp->aifs, 88 acp->admission_control_mandatory, 89 e); 90 ac->cw = wmm_ecw(acp->cwmin, acp->cwmax); 91 ac->txop_limit = host_to_le16(acp->txop_limit); 92 } 93 94 pos = (u8 *) (wmm + 1); 95 eid[1] = pos - eid - 2; /* element length */ 96 97 return pos; 98} 99 100 101/* 102 * This function is called when a station sends an association request with 103 * WMM info element. The function returns 1 on success or 0 on any error in WMM 104 * element. eid does not include Element ID and Length octets. 105 */ 106int hostapd_eid_wmm_valid(struct hostapd_data *hapd, const u8 *eid, size_t len) 107{ 108 struct wmm_information_element *wmm; 109 110 wpa_hexdump(MSG_MSGDUMP, "WMM IE", eid, len); 111 112 if (len < sizeof(struct wmm_information_element)) { 113 wpa_printf(MSG_DEBUG, "Too short WMM IE (len=%lu)", 114 (unsigned long) len); 115 return 0; 116 } 117 118 wmm = (struct wmm_information_element *) eid; 119 wpa_printf(MSG_DEBUG, "Validating WMM IE: OUI %02x:%02x:%02x " 120 "OUI type %d OUI sub-type %d version %d QoS info 0x%x", 121 wmm->oui[0], wmm->oui[1], wmm->oui[2], wmm->oui_type, 122 wmm->oui_subtype, wmm->version, wmm->qos_info); 123 if (wmm->oui_subtype != WMM_OUI_SUBTYPE_INFORMATION_ELEMENT || 124 wmm->version != WMM_VERSION) { 125 wpa_printf(MSG_DEBUG, "Unsupported WMM IE Subtype/Version"); 126 return 0; 127 } 128 129 return 1; 130} 131 132 133static void wmm_send_action(struct hostapd_data *hapd, const u8 *addr, 134 const struct wmm_tspec_element *tspec, 135 u8 action_code, u8 dialogue_token, u8 status_code) 136{ 137 u8 buf[256]; 138 struct ieee80211_mgmt *m = (struct ieee80211_mgmt *) buf; 139 struct wmm_tspec_element *t = (struct wmm_tspec_element *) 140 m->u.action.u.wmm_action.variable; 141 int len; 142 143 hostapd_logger(hapd, addr, HOSTAPD_MODULE_IEEE80211, 144 HOSTAPD_LEVEL_DEBUG, 145 "action response - reason %d", status_code); 146 os_memset(buf, 0, sizeof(buf)); 147 m->frame_control = IEEE80211_FC(WLAN_FC_TYPE_MGMT, 148 WLAN_FC_STYPE_ACTION); 149 os_memcpy(m->da, addr, ETH_ALEN); 150 os_memcpy(m->sa, hapd->own_addr, ETH_ALEN); 151 os_memcpy(m->bssid, hapd->own_addr, ETH_ALEN); 152 m->u.action.category = WLAN_ACTION_WMM; 153 m->u.action.u.wmm_action.action_code = action_code; 154 m->u.action.u.wmm_action.dialog_token = dialogue_token; 155 m->u.action.u.wmm_action.status_code = status_code; 156 os_memcpy(t, tspec, sizeof(struct wmm_tspec_element)); 157 len = ((u8 *) (t + 1)) - buf; 158 159 if (hostapd_drv_send_mlme(hapd, m, len, 0) < 0) 160 wpa_printf(MSG_INFO, "wmm_send_action: send failed"); 161} 162 163 164int wmm_process_tspec(struct wmm_tspec_element *tspec) 165{ 166 int medium_time, pps, duration; 167 int up, psb, dir, tid; 168 u16 val, surplus; 169 170 up = (tspec->ts_info[1] >> 3) & 0x07; 171 psb = (tspec->ts_info[1] >> 2) & 0x01; 172 dir = (tspec->ts_info[0] >> 5) & 0x03; 173 tid = (tspec->ts_info[0] >> 1) & 0x0f; 174 wpa_printf(MSG_DEBUG, "WMM: TS Info: UP=%d PSB=%d Direction=%d TID=%d", 175 up, psb, dir, tid); 176 val = le_to_host16(tspec->nominal_msdu_size); 177 wpa_printf(MSG_DEBUG, "WMM: Nominal MSDU Size: %d%s", 178 val & 0x7fff, val & 0x8000 ? " (fixed)" : ""); 179 wpa_printf(MSG_DEBUG, "WMM: Mean Data Rate: %u bps", 180 le_to_host32(tspec->mean_data_rate)); 181 wpa_printf(MSG_DEBUG, "WMM: Minimum PHY Rate: %u bps", 182 le_to_host32(tspec->minimum_phy_rate)); 183 val = le_to_host16(tspec->surplus_bandwidth_allowance); 184 wpa_printf(MSG_DEBUG, "WMM: Surplus Bandwidth Allowance: %u.%04u", 185 val >> 13, 10000 * (val & 0x1fff) / 0x2000); 186 187 val = le_to_host16(tspec->nominal_msdu_size); 188 if (val == 0) { 189 wpa_printf(MSG_DEBUG, "WMM: Invalid Nominal MSDU Size (0)"); 190 return WMM_ADDTS_STATUS_INVALID_PARAMETERS; 191 } 192 /* pps = Ceiling((Mean Data Rate / 8) / Nominal MSDU Size) */ 193 pps = ((le_to_host32(tspec->mean_data_rate) / 8) + val - 1) / val; 194 wpa_printf(MSG_DEBUG, "WMM: Packets-per-second estimate for TSPEC: %d", 195 pps); 196 197 if (le_to_host32(tspec->minimum_phy_rate) < 1000000) { 198 wpa_printf(MSG_DEBUG, "WMM: Too small Minimum PHY Rate"); 199 return WMM_ADDTS_STATUS_INVALID_PARAMETERS; 200 } 201 202 duration = (le_to_host16(tspec->nominal_msdu_size) & 0x7fff) * 8 / 203 (le_to_host32(tspec->minimum_phy_rate) / 1000000) + 204 50 /* FIX: proper SIFS + ACK duration */; 205 206 /* unsigned binary number with an implicit binary point after the 207 * leftmost 3 bits, i.e., 0x2000 = 1.0 */ 208 surplus = le_to_host16(tspec->surplus_bandwidth_allowance); 209 if (surplus <= 0x2000) { 210 wpa_printf(MSG_DEBUG, "WMM: Surplus Bandwidth Allowance not " 211 "greater than unity"); 212 return WMM_ADDTS_STATUS_INVALID_PARAMETERS; 213 } 214 215 medium_time = surplus * pps * duration / 0x2000; 216 wpa_printf(MSG_DEBUG, "WMM: Estimated medium time: %u", medium_time); 217 218 /* 219 * TODO: store list of granted (and still active) TSPECs and check 220 * whether there is available medium time for this request. For now, 221 * just refuse requests that would by themselves take very large 222 * portion of the available bandwidth. 223 */ 224 if (medium_time > 750000) { 225 wpa_printf(MSG_DEBUG, "WMM: Refuse TSPEC request for over " 226 "75%% of available bandwidth"); 227 return WMM_ADDTS_STATUS_REFUSED; 228 } 229 230 /* Convert to 32 microseconds per second unit */ 231 tspec->medium_time = host_to_le16(medium_time / 32); 232 233 return WMM_ADDTS_STATUS_ADMISSION_ACCEPTED; 234} 235 236 237static void wmm_addts_req(struct hostapd_data *hapd, 238 const struct ieee80211_mgmt *mgmt, 239 struct wmm_tspec_element *tspec, size_t len) 240{ 241 const u8 *end = ((const u8 *) mgmt) + len; 242 int res; 243 244 if ((const u8 *) (tspec + 1) > end) { 245 wpa_printf(MSG_DEBUG, "WMM: TSPEC overflow in ADDTS Request"); 246 return; 247 } 248 249 wpa_printf(MSG_DEBUG, "WMM: ADDTS Request (Dialog Token %d) for TSPEC " 250 "from " MACSTR, 251 mgmt->u.action.u.wmm_action.dialog_token, 252 MAC2STR(mgmt->sa)); 253 254 res = wmm_process_tspec(tspec); 255 wpa_printf(MSG_DEBUG, "WMM: ADDTS processing result: %d", res); 256 257 wmm_send_action(hapd, mgmt->sa, tspec, WMM_ACTION_CODE_ADDTS_RESP, 258 mgmt->u.action.u.wmm_action.dialog_token, res); 259} 260 261 262void hostapd_wmm_action(struct hostapd_data *hapd, 263 const struct ieee80211_mgmt *mgmt, size_t len) 264{ 265 int action_code; 266 int left = len - IEEE80211_HDRLEN - 4; 267 const u8 *pos = ((const u8 *) mgmt) + IEEE80211_HDRLEN + 4; 268 struct ieee802_11_elems elems; 269 struct sta_info *sta = ap_get_sta(hapd, mgmt->sa); 270 271 /* check that the request comes from a valid station */ 272 if (!sta || 273 (sta->flags & (WLAN_STA_ASSOC | WLAN_STA_WMM)) != 274 (WLAN_STA_ASSOC | WLAN_STA_WMM)) { 275 hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211, 276 HOSTAPD_LEVEL_DEBUG, 277 "wmm action received is not from associated wmm" 278 " station"); 279 /* TODO: respond with action frame refused status code */ 280 return; 281 } 282 283 /* extract the tspec info element */ 284 if (ieee802_11_parse_elems(pos, left, &elems, 1) == ParseFailed) { 285 hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211, 286 HOSTAPD_LEVEL_DEBUG, 287 "hostapd_wmm_action - could not parse wmm " 288 "action"); 289 /* TODO: respond with action frame invalid parameters status 290 * code */ 291 return; 292 } 293 294 if (!elems.wmm_tspec || 295 elems.wmm_tspec_len != (sizeof(struct wmm_tspec_element) - 2)) { 296 hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211, 297 HOSTAPD_LEVEL_DEBUG, 298 "hostapd_wmm_action - missing or wrong length " 299 "tspec"); 300 /* TODO: respond with action frame invalid parameters status 301 * code */ 302 return; 303 } 304 305 /* TODO: check the request is for an AC with ACM set, if not, refuse 306 * request */ 307 308 action_code = mgmt->u.action.u.wmm_action.action_code; 309 switch (action_code) { 310 case WMM_ACTION_CODE_ADDTS_REQ: 311 wmm_addts_req(hapd, mgmt, (struct wmm_tspec_element *) 312 (elems.wmm_tspec - 2), len); 313 return; 314#if 0 315 /* TODO: needed for client implementation */ 316 case WMM_ACTION_CODE_ADDTS_RESP: 317 wmm_setup_request(hapd, mgmt, len); 318 return; 319 /* TODO: handle station teardown requests */ 320 case WMM_ACTION_CODE_DELTS: 321 wmm_teardown(hapd, mgmt, len); 322 return; 323#endif 324 } 325 326 hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211, 327 HOSTAPD_LEVEL_DEBUG, 328 "hostapd_wmm_action - unknown action code %d", 329 action_code); 330} 331