wmm.c revision 8d520ff1dc2da35cdca849e982051b86468016d8
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 wmm->qos_info |= 0x80; 77 78 wmm->reserved = 0; 79 80 /* fill in a parameter set record for each AC */ 81 for (e = 0; e < 4; e++) { 82 struct wmm_ac_parameter *ac = &wmm->ac[e]; 83 struct hostapd_wmm_ac_params *acp = 84 &hapd->iconf->wmm_ac_params[e]; 85 86 ac->aci_aifsn = wmm_aci_aifsn(acp->aifs, 87 acp->admission_control_mandatory, 88 e); 89 ac->cw = wmm_ecw(acp->cwmin, acp->cwmax); 90 ac->txop_limit = host_to_le16(acp->txop_limit); 91 } 92 93 pos = (u8 *) (wmm + 1); 94 eid[1] = pos - eid - 2; /* element length */ 95 96 return pos; 97} 98 99 100/* This function is called when a station sends an association request with 101 * WMM info element. The function returns zero on success or non-zero on any 102 * error in WMM element. eid does not include Element ID and Length octets. */ 103int hostapd_eid_wmm_valid(struct hostapd_data *hapd, const u8 *eid, size_t len) 104{ 105 struct wmm_information_element *wmm; 106 107 wpa_hexdump(MSG_MSGDUMP, "WMM IE", eid, len); 108 109 if (len < sizeof(struct wmm_information_element)) { 110 wpa_printf(MSG_DEBUG, "Too short WMM IE (len=%lu)", 111 (unsigned long) len); 112 return -1; 113 } 114 115 wmm = (struct wmm_information_element *) eid; 116 wpa_printf(MSG_DEBUG, "Validating WMM IE: OUI %02x:%02x:%02x " 117 "OUI type %d OUI sub-type %d version %d QoS info 0x%x", 118 wmm->oui[0], wmm->oui[1], wmm->oui[2], wmm->oui_type, 119 wmm->oui_subtype, wmm->version, wmm->qos_info); 120 if (wmm->oui_subtype != WMM_OUI_SUBTYPE_INFORMATION_ELEMENT || 121 wmm->version != WMM_VERSION) { 122 wpa_printf(MSG_DEBUG, "Unsupported WMM IE Subtype/Version"); 123 return -1; 124 } 125 126 return 0; 127} 128 129 130static void wmm_send_action(struct hostapd_data *hapd, const u8 *addr, 131 const struct wmm_tspec_element *tspec, 132 u8 action_code, u8 dialogue_token, u8 status_code) 133{ 134 u8 buf[256]; 135 struct ieee80211_mgmt *m = (struct ieee80211_mgmt *) buf; 136 struct wmm_tspec_element *t = (struct wmm_tspec_element *) 137 m->u.action.u.wmm_action.variable; 138 int len; 139 140 hostapd_logger(hapd, addr, HOSTAPD_MODULE_IEEE80211, 141 HOSTAPD_LEVEL_DEBUG, 142 "action response - reason %d", status_code); 143 os_memset(buf, 0, sizeof(buf)); 144 m->frame_control = IEEE80211_FC(WLAN_FC_TYPE_MGMT, 145 WLAN_FC_STYPE_ACTION); 146 os_memcpy(m->da, addr, ETH_ALEN); 147 os_memcpy(m->sa, hapd->own_addr, ETH_ALEN); 148 os_memcpy(m->bssid, hapd->own_addr, ETH_ALEN); 149 m->u.action.category = WLAN_ACTION_WMM; 150 m->u.action.u.wmm_action.action_code = action_code; 151 m->u.action.u.wmm_action.dialog_token = dialogue_token; 152 m->u.action.u.wmm_action.status_code = status_code; 153 os_memcpy(t, tspec, sizeof(struct wmm_tspec_element)); 154 len = ((u8 *) (t + 1)) - buf; 155 156 if (hostapd_drv_send_mlme(hapd, m, len) < 0) 157 perror("wmm_send_action: send"); 158} 159 160 161int wmm_process_tspec(struct wmm_tspec_element *tspec) 162{ 163 int medium_time, pps, duration; 164 int up, psb, dir, tid; 165 u16 val, surplus; 166 167 up = (tspec->ts_info[1] >> 3) & 0x07; 168 psb = (tspec->ts_info[1] >> 2) & 0x01; 169 dir = (tspec->ts_info[0] >> 5) & 0x03; 170 tid = (tspec->ts_info[0] >> 1) & 0x0f; 171 wpa_printf(MSG_DEBUG, "WMM: TS Info: UP=%d PSB=%d Direction=%d TID=%d", 172 up, psb, dir, tid); 173 val = le_to_host16(tspec->nominal_msdu_size); 174 wpa_printf(MSG_DEBUG, "WMM: Nominal MSDU Size: %d%s", 175 val & 0x7fff, val & 0x8000 ? " (fixed)" : ""); 176 wpa_printf(MSG_DEBUG, "WMM: Mean Data Rate: %u bps", 177 le_to_host32(tspec->mean_data_rate)); 178 wpa_printf(MSG_DEBUG, "WMM: Minimum PHY Rate: %u bps", 179 le_to_host32(tspec->minimum_phy_rate)); 180 val = le_to_host16(tspec->surplus_bandwidth_allowance); 181 wpa_printf(MSG_DEBUG, "WMM: Surplus Bandwidth Allowance: %u.%04u", 182 val >> 13, 10000 * (val & 0x1fff) / 0x2000); 183 184 val = le_to_host16(tspec->nominal_msdu_size); 185 if (val == 0) { 186 wpa_printf(MSG_DEBUG, "WMM: Invalid Nominal MSDU Size (0)"); 187 return WMM_ADDTS_STATUS_INVALID_PARAMETERS; 188 } 189 /* pps = Ceiling((Mean Data Rate / 8) / Nominal MSDU Size) */ 190 pps = ((le_to_host32(tspec->mean_data_rate) / 8) + val - 1) / val; 191 wpa_printf(MSG_DEBUG, "WMM: Packets-per-second estimate for TSPEC: %d", 192 pps); 193 194 if (le_to_host32(tspec->minimum_phy_rate) < 1000000) { 195 wpa_printf(MSG_DEBUG, "WMM: Too small Minimum PHY Rate"); 196 return WMM_ADDTS_STATUS_INVALID_PARAMETERS; 197 } 198 199 duration = (le_to_host16(tspec->nominal_msdu_size) & 0x7fff) * 8 / 200 (le_to_host32(tspec->minimum_phy_rate) / 1000000) + 201 50 /* FIX: proper SIFS + ACK duration */; 202 203 /* unsigned binary number with an implicit binary point after the 204 * leftmost 3 bits, i.e., 0x2000 = 1.0 */ 205 surplus = le_to_host16(tspec->surplus_bandwidth_allowance); 206 if (surplus <= 0x2000) { 207 wpa_printf(MSG_DEBUG, "WMM: Surplus Bandwidth Allowance not " 208 "greater than unity"); 209 return WMM_ADDTS_STATUS_INVALID_PARAMETERS; 210 } 211 212 medium_time = surplus * pps * duration / 0x2000; 213 wpa_printf(MSG_DEBUG, "WMM: Estimated medium time: %u", medium_time); 214 215 /* 216 * TODO: store list of granted (and still active) TSPECs and check 217 * whether there is available medium time for this request. For now, 218 * just refuse requests that would by themselves take very large 219 * portion of the available bandwidth. 220 */ 221 if (medium_time > 750000) { 222 wpa_printf(MSG_DEBUG, "WMM: Refuse TSPEC request for over " 223 "75%% of available bandwidth"); 224 return WMM_ADDTS_STATUS_REFUSED; 225 } 226 227 /* Convert to 32 microseconds per second unit */ 228 tspec->medium_time = host_to_le16(medium_time / 32); 229 230 return WMM_ADDTS_STATUS_ADMISSION_ACCEPTED; 231} 232 233 234static void wmm_addts_req(struct hostapd_data *hapd, 235 const struct ieee80211_mgmt *mgmt, 236 struct wmm_tspec_element *tspec, size_t len) 237{ 238 const u8 *end = ((const u8 *) mgmt) + len; 239 int res; 240 241 if ((const u8 *) (tspec + 1) > end) { 242 wpa_printf(MSG_DEBUG, "WMM: TSPEC overflow in ADDTS Request"); 243 return; 244 } 245 246 wpa_printf(MSG_DEBUG, "WMM: ADDTS Request (Dialog Token %d) for TSPEC " 247 "from " MACSTR, 248 mgmt->u.action.u.wmm_action.dialog_token, 249 MAC2STR(mgmt->sa)); 250 251 res = wmm_process_tspec(tspec); 252 wpa_printf(MSG_DEBUG, "WMM: ADDTS processing result: %d", res); 253 254 wmm_send_action(hapd, mgmt->sa, tspec, WMM_ACTION_CODE_ADDTS_RESP, 255 mgmt->u.action.u.wmm_action.dialog_token, res); 256} 257 258 259void hostapd_wmm_action(struct hostapd_data *hapd, 260 const struct ieee80211_mgmt *mgmt, size_t len) 261{ 262 int action_code; 263 int left = len - IEEE80211_HDRLEN - 4; 264 const u8 *pos = ((const u8 *) mgmt) + IEEE80211_HDRLEN + 4; 265 struct ieee802_11_elems elems; 266 struct sta_info *sta = ap_get_sta(hapd, mgmt->sa); 267 268 /* check that the request comes from a valid station */ 269 if (!sta || 270 (sta->flags & (WLAN_STA_ASSOC | WLAN_STA_WMM)) != 271 (WLAN_STA_ASSOC | WLAN_STA_WMM)) { 272 hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211, 273 HOSTAPD_LEVEL_DEBUG, 274 "wmm action received is not from associated wmm" 275 " station"); 276 /* TODO: respond with action frame refused status code */ 277 return; 278 } 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} 328