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 "wmm.h" 27 28 29 /* TODO: maintain separate sequence and fragment numbers for each AC 30 * TODO: IGMP snooping to track which multicasts to forward - and use QOS-DATA 31 * if only WMM stations are receiving a certain group */ 32 33 34 static inline u8 wmm_aci_aifsn(int aifsn, int acm, int aci) 35 { 36 u8 ret; 37 ret = (aifsn << WMM_AC_AIFNS_SHIFT) & WMM_AC_AIFSN_MASK; 38 if (acm) 39 ret |= WMM_AC_ACM; 40 ret |= (aci << WMM_AC_ACI_SHIFT) & WMM_AC_ACI_MASK; 41 return ret; 42 } 43 44 45 static inline u8 wmm_ecw(int ecwmin, int ecwmax) 46 { 47 return ((ecwmin << WMM_AC_ECWMIN_SHIFT) & WMM_AC_ECWMIN_MASK) | 48 ((ecwmax << WMM_AC_ECWMAX_SHIFT) & WMM_AC_ECWMAX_MASK); 49 } 50 51 52 /* 53 * Add WMM Parameter Element to Beacon, Probe Response, and (Re)Association 54 * Response frames. 55 */ 56 u8 * hostapd_eid_wmm(struct hostapd_data *hapd, u8 *eid) 57 { 58 u8 *pos = eid; 59 struct wmm_parameter_element *wmm = 60 (struct wmm_parameter_element *) (pos + 2); 61 int e; 62 63 if (!hapd->conf->wmm_enabled) 64 return eid; 65 eid[0] = WLAN_EID_VENDOR_SPECIFIC; 66 wmm->oui[0] = 0x00; 67 wmm->oui[1] = 0x50; 68 wmm->oui[2] = 0xf2; 69 wmm->oui_type = WMM_OUI_TYPE; 70 wmm->oui_subtype = WMM_OUI_SUBTYPE_PARAMETER_ELEMENT; 71 wmm->version = WMM_VERSION; 72 wmm->qos_info = hapd->parameter_set_count & 0xf; 73 74 if (hapd->conf->wmm_uapsd) 75 wmm->qos_info |= 0x80; 76 77 /* fill in a parameter set record for each AC */ 78 for (e = 0; e < 4; e++) { 79 struct wmm_ac_parameter *ac = &wmm->ac[e]; 80 struct hostapd_wmm_ac_params *acp = 81 &hapd->iconf->wmm_ac_params[e]; 82 83 ac->aci_aifsn = wmm_aci_aifsn(acp->aifs, 84 acp->admission_control_mandatory, 85 e); 86 ac->cw = wmm_ecw(acp->cwmin, acp->cwmax); 87 ac->txop_limit = host_to_le16(acp->txop_limit); 88 } 89 90 pos = (u8 *) (wmm + 1); 91 eid[1] = pos - eid - 2; /* element length */ 92 93 return pos; 94 } 95 96 97 /* This function is called when a station sends an association request with 98 * WMM info element. The function returns zero on success or non-zero on any 99 * error in WMM element. eid does not include Element ID and Length octets. */ 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 -1; 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 -1; 121 } 122 123 return 0; 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 (hapd->drv.send_mgmt_frame(hapd, m, len) < 0) 154 perror("wmm_send_action: send"); 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 /* 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 } 325