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00001 /* 00002 * hostapd / WMM (Wi-Fi Multimedia) 00003 * Copyright 2002-2003, Instant802 Networks, Inc. 00004 * Copyright 2005-2006, Devicescape Software, Inc. 00005 * Copyright (c) 2009, Jouni Malinen <j@w1.fi> 00006 * 00007 * This program is free software; you can redistribute it and/or modify 00008 * it under the terms of the GNU General Public License version 2 as 00009 * published by the Free Software Foundation. 00010 * 00011 * Alternatively, this software may be distributed under the terms of BSD 00012 * license. 00013 * 00014 * See README and COPYING for more details. 00015 */ 00016 00017 #include "utils/includes.h" 00018 00019 #include "utils/common.h" 00020 #include "common/ieee802_11_defs.h" 00021 #include "common/ieee802_11_common.h" 00022 #include "hostapd.h" 00023 #include "ieee802_11.h" 00024 #include "sta_info.h" 00025 #include "ap_config.h" 00026 #include "wmm.h" 00027 00028 00029 /* TODO: maintain separate sequence and fragment numbers for each AC 00030 * TODO: IGMP snooping to track which multicasts to forward - and use QOS-DATA 00031 * if only WMM stations are receiving a certain group */ 00032 00033 00034 static inline u8 wmm_aci_aifsn(int aifsn, int acm, int aci) 00035 { 00036 u8 ret; 00037 ret = (aifsn << WMM_AC_AIFNS_SHIFT) & WMM_AC_AIFSN_MASK; 00038 if (acm) 00039 ret |= WMM_AC_ACM; 00040 ret |= (aci << WMM_AC_ACI_SHIFT) & WMM_AC_ACI_MASK; 00041 return ret; 00042 } 00043 00044 00045 static inline u8 wmm_ecw(int ecwmin, int ecwmax) 00046 { 00047 return ((ecwmin << WMM_AC_ECWMIN_SHIFT) & WMM_AC_ECWMIN_MASK) | 00048 ((ecwmax << WMM_AC_ECWMAX_SHIFT) & WMM_AC_ECWMAX_MASK); 00049 } 00050 00051 00052 /* 00053 * Add WMM Parameter Element to Beacon, Probe Response, and (Re)Association 00054 * Response frames. 00055 */ 00056 u8 * hostapd_eid_wmm(struct hostapd_data *hapd, u8 *eid) 00057 { 00058 u8 *pos = eid; 00059 struct wmm_parameter_element *wmm = 00060 (struct wmm_parameter_element *) (pos + 2); 00061 int e; 00062 00063 if (!hapd->conf->wmm_enabled) 00064 return eid; 00065 eid[0] = WLAN_EID_VENDOR_SPECIFIC; 00066 wmm->oui[0] = 0x00; 00067 wmm->oui[1] = 0x50; 00068 wmm->oui[2] = 0xf2; 00069 wmm->oui_type = WMM_OUI_TYPE; 00070 wmm->oui_subtype = WMM_OUI_SUBTYPE_PARAMETER_ELEMENT; 00071 wmm->version = WMM_VERSION; 00072 wmm->qos_info = hapd->parameter_set_count & 0xf; 00073 00074 if (hapd->conf->wmm_uapsd) 00075 wmm->qos_info |= 0x80; 00076 00077 /* fill in a parameter set record for each AC */ 00078 for (e = 0; e < 4; e++) { 00079 struct wmm_ac_parameter *ac = &wmm->ac[e]; 00080 struct hostapd_wmm_ac_params *acp = 00081 &hapd->iconf->wmm_ac_params[e]; 00082 00083 ac->aci_aifsn = wmm_aci_aifsn(acp->aifs, 00084 acp->admission_control_mandatory, 00085 e); 00086 ac->cw = wmm_ecw(acp->cwmin, acp->cwmax); 00087 ac->txop_limit = host_to_le16(acp->txop_limit); 00088 } 00089 00090 pos = (u8 *) (wmm + 1); 00091 eid[1] = pos - eid - 2; /* element length */ 00092 00093 return pos; 00094 } 00095 00096 00097 /* This function is called when a station sends an association request with 00098 * WMM info element. The function returns zero on success or non-zero on any 00099 * error in WMM element. eid does not include Element ID and Length octets. */ 00100 int hostapd_eid_wmm_valid(struct hostapd_data *hapd, const u8 *eid, size_t len) 00101 { 00102 struct wmm_information_element *wmm; 00103 00104 wpa_hexdump(MSG_MSGDUMP, "WMM IE", eid, len); 00105 00106 if (len < sizeof(struct wmm_information_element)) { 00107 wpa_printf(MSG_DEBUG, "Too short WMM IE (len=%lu)", 00108 (unsigned long) len); 00109 return -1; 00110 } 00111 00112 wmm = (struct wmm_information_element *) eid; 00113 wpa_printf(MSG_DEBUG, "Validating WMM IE: OUI %02x:%02x:%02x " 00114 "OUI type %d OUI sub-type %d version %d QoS info 0x%x", 00115 wmm->oui[0], wmm->oui[1], wmm->oui[2], wmm->oui_type, 00116 wmm->oui_subtype, wmm->version, wmm->qos_info); 00117 if (wmm->oui_subtype != WMM_OUI_SUBTYPE_INFORMATION_ELEMENT || 00118 wmm->version != WMM_VERSION) { 00119 wpa_printf(MSG_DEBUG, "Unsupported WMM IE Subtype/Version"); 00120 return -1; 00121 } 00122 00123 return 0; 00124 } 00125 00126 00127 static void wmm_send_action(struct hostapd_data *hapd, const u8 *addr, 00128 const struct wmm_tspec_element *tspec, 00129 u8 action_code, u8 dialogue_token, u8 status_code) 00130 { 00131 u8 buf[256]; 00132 struct ieee80211_mgmt *m = (struct ieee80211_mgmt *) buf; 00133 struct wmm_tspec_element *t = (struct wmm_tspec_element *) 00134 m->u.action.u.wmm_action.variable; 00135 int len; 00136 00137 hostapd_logger(hapd, addr, HOSTAPD_MODULE_IEEE80211, 00138 HOSTAPD_LEVEL_DEBUG, 00139 "action response - reason %d", status_code); 00140 os_memset(buf, 0, sizeof(buf)); 00141 m->frame_control = IEEE80211_FC(WLAN_FC_TYPE_MGMT, 00142 WLAN_FC_STYPE_ACTION); 00143 os_memcpy(m->da, addr, ETH_ALEN); 00144 os_memcpy(m->sa, hapd->own_addr, ETH_ALEN); 00145 os_memcpy(m->bssid, hapd->own_addr, ETH_ALEN); 00146 m->u.action.category = WLAN_ACTION_WMM; 00147 m->u.action.u.wmm_action.action_code = action_code; 00148 m->u.action.u.wmm_action.dialog_token = dialogue_token; 00149 m->u.action.u.wmm_action.status_code = status_code; 00150 os_memcpy(t, tspec, sizeof(struct wmm_tspec_element)); 00151 len = ((u8 *) (t + 1)) - buf; 00152 00153 if (hapd->drv.send_mgmt_frame(hapd, m, len) < 0) 00154 perror("wmm_send_action: send"); 00155 } 00156 00157 00158 int wmm_process_tspec(struct wmm_tspec_element *tspec) 00159 { 00160 int medium_time, pps, duration; 00161 int up, psb, dir, tid; 00162 u16 val, surplus; 00163 00164 up = (tspec->ts_info[1] >> 3) & 0x07; 00165 psb = (tspec->ts_info[1] >> 2) & 0x01; 00166 dir = (tspec->ts_info[0] >> 5) & 0x03; 00167 tid = (tspec->ts_info[0] >> 1) & 0x0f; 00168 wpa_printf(MSG_DEBUG, "WMM: TS Info: UP=%d PSB=%d Direction=%d TID=%d", 00169 up, psb, dir, tid); 00170 val = le_to_host16(tspec->nominal_msdu_size); 00171 wpa_printf(MSG_DEBUG, "WMM: Nominal MSDU Size: %d%s", 00172 val & 0x7fff, val & 0x8000 ? " (fixed)" : ""); 00173 wpa_printf(MSG_DEBUG, "WMM: Mean Data Rate: %u bps", 00174 le_to_host32(tspec->mean_data_rate)); 00175 wpa_printf(MSG_DEBUG, "WMM: Minimum PHY Rate: %u bps", 00176 le_to_host32(tspec->minimum_phy_rate)); 00177 val = le_to_host16(tspec->surplus_bandwidth_allowance); 00178 wpa_printf(MSG_DEBUG, "WMM: Surplus Bandwidth Allowance: %u.%04u", 00179 val >> 13, 10000 * (val & 0x1fff) / 0x2000); 00180 00181 val = le_to_host16(tspec->nominal_msdu_size); 00182 if (val == 0) { 00183 wpa_printf(MSG_DEBUG, "WMM: Invalid Nominal MSDU Size (0)"); 00184 return WMM_ADDTS_STATUS_INVALID_PARAMETERS; 00185 } 00186 /* pps = Ceiling((Mean Data Rate / 8) / Nominal MSDU Size) */ 00187 pps = ((le_to_host32(tspec->mean_data_rate) / 8) + val - 1) / val; 00188 wpa_printf(MSG_DEBUG, "WMM: Packets-per-second estimate for TSPEC: %d", 00189 pps); 00190 00191 if (le_to_host32(tspec->minimum_phy_rate) < 1000000) { 00192 wpa_printf(MSG_DEBUG, "WMM: Too small Minimum PHY Rate"); 00193 return WMM_ADDTS_STATUS_INVALID_PARAMETERS; 00194 } 00195 00196 duration = (le_to_host16(tspec->nominal_msdu_size) & 0x7fff) * 8 / 00197 (le_to_host32(tspec->minimum_phy_rate) / 1000000) + 00198 50 /* FIX: proper SIFS + ACK duration */; 00199 00200 /* unsigned binary number with an implicit binary point after the 00201 * leftmost 3 bits, i.e., 0x2000 = 1.0 */ 00202 surplus = le_to_host16(tspec->surplus_bandwidth_allowance); 00203 if (surplus <= 0x2000) { 00204 wpa_printf(MSG_DEBUG, "WMM: Surplus Bandwidth Allowance not " 00205 "greater than unity"); 00206 return WMM_ADDTS_STATUS_INVALID_PARAMETERS; 00207 } 00208 00209 medium_time = surplus * pps * duration / 0x2000; 00210 wpa_printf(MSG_DEBUG, "WMM: Estimated medium time: %u", medium_time); 00211 00212 /* 00213 * TODO: store list of granted (and still active) TSPECs and check 00214 * whether there is available medium time for this request. For now, 00215 * just refuse requests that would by themselves take very large 00216 * portion of the available bandwidth. 00217 */ 00218 if (medium_time > 750000) { 00219 wpa_printf(MSG_DEBUG, "WMM: Refuse TSPEC request for over " 00220 "75%% of available bandwidth"); 00221 return WMM_ADDTS_STATUS_REFUSED; 00222 } 00223 00224 /* Convert to 32 microseconds per second unit */ 00225 tspec->medium_time = host_to_le16(medium_time / 32); 00226 00227 return WMM_ADDTS_STATUS_ADMISSION_ACCEPTED; 00228 } 00229 00230 00231 static void wmm_addts_req(struct hostapd_data *hapd, 00232 const struct ieee80211_mgmt *mgmt, 00233 struct wmm_tspec_element *tspec, size_t len) 00234 { 00235 const u8 *end = ((const u8 *) mgmt) + len; 00236 int res; 00237 00238 if ((const u8 *) (tspec + 1) > end) { 00239 wpa_printf(MSG_DEBUG, "WMM: TSPEC overflow in ADDTS Request"); 00240 return; 00241 } 00242 00243 wpa_printf(MSG_DEBUG, "WMM: ADDTS Request (Dialog Token %d) for TSPEC " 00244 "from " MACSTR, 00245 mgmt->u.action.u.wmm_action.dialog_token, 00246 MAC2STR(mgmt->sa)); 00247 00248 res = wmm_process_tspec(tspec); 00249 wpa_printf(MSG_DEBUG, "WMM: ADDTS processing result: %d", res); 00250 00251 wmm_send_action(hapd, mgmt->sa, tspec, WMM_ACTION_CODE_ADDTS_RESP, 00252 mgmt->u.action.u.wmm_action.dialog_token, res); 00253 } 00254 00255 00256 void hostapd_wmm_action(struct hostapd_data *hapd, 00257 const struct ieee80211_mgmt *mgmt, size_t len) 00258 { 00259 int action_code; 00260 int left = len - IEEE80211_HDRLEN - 4; 00261 const u8 *pos = ((const u8 *) mgmt) + IEEE80211_HDRLEN + 4; 00262 struct ieee802_11_elems elems; 00263 struct sta_info *sta = ap_get_sta(hapd, mgmt->sa); 00264 00265 /* check that the request comes from a valid station */ 00266 if (!sta || 00267 (sta->flags & (WLAN_STA_ASSOC | WLAN_STA_WMM)) != 00268 (WLAN_STA_ASSOC | WLAN_STA_WMM)) { 00269 hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211, 00270 HOSTAPD_LEVEL_DEBUG, 00271 "wmm action received is not from associated wmm" 00272 " station"); 00273 /* TODO: respond with action frame refused status code */ 00274 return; 00275 } 00276 00277 /* extract the tspec info element */ 00278 if (ieee802_11_parse_elems(pos, left, &elems, 1) == ParseFailed) { 00279 hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211, 00280 HOSTAPD_LEVEL_DEBUG, 00281 "hostapd_wmm_action - could not parse wmm " 00282 "action"); 00283 /* TODO: respond with action frame invalid parameters status 00284 * code */ 00285 return; 00286 } 00287 00288 if (!elems.wmm_tspec || 00289 elems.wmm_tspec_len != (sizeof(struct wmm_tspec_element) - 2)) { 00290 hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211, 00291 HOSTAPD_LEVEL_DEBUG, 00292 "hostapd_wmm_action - missing or wrong length " 00293 "tspec"); 00294 /* TODO: respond with action frame invalid parameters status 00295 * code */ 00296 return; 00297 } 00298 00299 /* TODO: check the request is for an AC with ACM set, if not, refuse 00300 * request */ 00301 00302 action_code = mgmt->u.action.u.wmm_action.action_code; 00303 switch (action_code) { 00304 case WMM_ACTION_CODE_ADDTS_REQ: 00305 wmm_addts_req(hapd, mgmt, (struct wmm_tspec_element *) 00306 (elems.wmm_tspec - 2), len); 00307 return; 00308 #if 0 00309 /* TODO: needed for client implementation */ 00310 case WMM_ACTION_CODE_ADDTS_RESP: 00311 wmm_setup_request(hapd, mgmt, len); 00312 return; 00313 /* TODO: handle station teardown requests */ 00314 case WMM_ACTION_CODE_DELTS: 00315 wmm_teardown(hapd, mgmt, len); 00316 return; 00317 #endif 00318 } 00319 00320 hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211, 00321 HOSTAPD_LEVEL_DEBUG, 00322 "hostapd_wmm_action - unknown action code %d", 00323 action_code); 00324 }