/* * hostapd / WMM (Wi-Fi Multimedia) * Copyright 2002-2003, Instant802 Networks, Inc. * Copyright 2005-2006, Devicescape Software, Inc. * Copyright (c) 2009, Jouni Malinen * * This software may be distributed under the terms of the BSD license. * See README for more details. */ #include "utils/includes.h" #include "utils/common.h" #include "common/ieee802_11_defs.h" #include "common/ieee802_11_common.h" #include "hostapd.h" #include "ieee802_11.h" #include "sta_info.h" #include "ap_config.h" #include "ap_drv_ops.h" #include "wmm.h" #ifndef MIN #define MIN(a, b) (((a) < (b)) ? (a) : (b)) #endif #ifndef MAX #define MAX(a, b) (((a) > (b)) ? (a) : (b)) #endif static inline u8 wmm_aci_aifsn(int aifsn, int acm, int aci) { u8 ret; ret = (aifsn << WMM_AC_AIFNS_SHIFT) & WMM_AC_AIFSN_MASK; if (acm) ret |= WMM_AC_ACM; ret |= (aci << WMM_AC_ACI_SHIFT) & WMM_AC_ACI_MASK; return ret; } static inline u8 wmm_ecw(int ecwmin, int ecwmax) { return ((ecwmin << WMM_AC_ECWMIN_SHIFT) & WMM_AC_ECWMIN_MASK) | ((ecwmax << WMM_AC_ECWMAX_SHIFT) & WMM_AC_ECWMAX_MASK); } static void wmm_set_regulatory_limit(const struct hostapd_wmm_ac_params *wmm_conf, struct hostapd_wmm_ac_params *wmm, const struct hostapd_wmm_rule *wmm_reg) { int ac; for (ac = 0; ac < WMM_AC_NUM; ac++) { wmm[ac].cwmin = MAX(wmm_conf[ac].cwmin, wmm_reg[ac].min_cwmin); wmm[ac].cwmax = MAX(wmm_conf[ac].cwmax, wmm_reg[ac].min_cwmax); wmm[ac].aifs = MAX(wmm_conf[ac].aifs, wmm_reg[ac].min_aifs); wmm[ac].txop_limit = MIN(wmm_conf[ac].txop_limit, wmm_reg[ac].max_txop); wmm[ac].admission_control_mandatory = wmm_conf[ac].admission_control_mandatory; } } /* * Calculate WMM regulatory limit if any. */ static void wmm_calc_regulatory_limit(struct hostapd_data *hapd, struct hostapd_wmm_ac_params *acp) { struct hostapd_hw_modes *mode = hapd->iface->current_mode; int c; os_memcpy(acp, hapd->iconf->wmm_ac_params, sizeof(hapd->iconf->wmm_ac_params)); for (c = 0; mode && c < mode->num_channels; c++) { struct hostapd_channel_data *chan = &mode->channels[c]; if (chan->freq != hapd->iface->freq) continue; if (chan->wmm_rules_valid) wmm_set_regulatory_limit(hapd->iconf->wmm_ac_params, acp, chan->wmm_rules); break; } /* * Check if we need to update set count. Since both were initialized to * zero we can compare the whole array in one shot. */ if (os_memcmp(acp, hapd->iface->prev_wmm, sizeof(hapd->iconf->wmm_ac_params)) != 0) { os_memcpy(hapd->iface->prev_wmm, acp, sizeof(hapd->iconf->wmm_ac_params)); hapd->parameter_set_count++; } } /* * Add WMM Parameter Element to Beacon, Probe Response, and (Re)Association * Response frames. */ u8 * hostapd_eid_wmm(struct hostapd_data *hapd, u8 *eid) { u8 *pos = eid; struct wmm_parameter_element *wmm = (struct wmm_parameter_element *) (pos + 2); struct hostapd_wmm_ac_params wmmp[WMM_AC_NUM] = { 0 }; int e; if (!hapd->conf->wmm_enabled) return eid; wmm_calc_regulatory_limit(hapd, wmmp); eid[0] = WLAN_EID_VENDOR_SPECIFIC; wmm->oui[0] = 0x00; wmm->oui[1] = 0x50; wmm->oui[2] = 0xf2; wmm->oui_type = WMM_OUI_TYPE; wmm->oui_subtype = WMM_OUI_SUBTYPE_PARAMETER_ELEMENT; wmm->version = WMM_VERSION; wmm->qos_info = hapd->parameter_set_count & 0xf; if (hapd->conf->wmm_uapsd && (hapd->iface->drv_flags & WPA_DRIVER_FLAGS_AP_UAPSD)) wmm->qos_info |= 0x80; wmm->reserved = 0; /* fill in a parameter set record for each AC */ for (e = 0; e < 4; e++) { struct wmm_ac_parameter *ac = &wmm->ac[e]; struct hostapd_wmm_ac_params *acp = &wmmp[e]; ac->aci_aifsn = wmm_aci_aifsn(acp->aifs, acp->admission_control_mandatory, e); ac->cw = wmm_ecw(acp->cwmin, acp->cwmax); ac->txop_limit = host_to_le16(acp->txop_limit); } pos = (u8 *) (wmm + 1); eid[1] = pos - eid - 2; /* element length */ return pos; } /* * This function is called when a station sends an association request with * WMM info element. The function returns 1 on success or 0 on any error in WMM * element. eid does not include Element ID and Length octets. */ int hostapd_eid_wmm_valid(struct hostapd_data *hapd, const u8 *eid, size_t len) { struct wmm_information_element *wmm; wpa_hexdump(MSG_MSGDUMP, "WMM IE", eid, len); if (len < sizeof(struct wmm_information_element)) { wpa_printf(MSG_DEBUG, "Too short WMM IE (len=%lu)", (unsigned long) len); return 0; } wmm = (struct wmm_information_element *) eid; wpa_printf(MSG_DEBUG, "Validating WMM IE: OUI %02x:%02x:%02x " "OUI type %d OUI sub-type %d version %d QoS info 0x%x", wmm->oui[0], wmm->oui[1], wmm->oui[2], wmm->oui_type, wmm->oui_subtype, wmm->version, wmm->qos_info); if (wmm->oui_subtype != WMM_OUI_SUBTYPE_INFORMATION_ELEMENT || wmm->version != WMM_VERSION) { wpa_printf(MSG_DEBUG, "Unsupported WMM IE Subtype/Version"); return 0; } return 1; } static void wmm_send_action(struct hostapd_data *hapd, const u8 *addr, const struct wmm_tspec_element *tspec, u8 action_code, u8 dialogue_token, u8 status_code) { u8 buf[256]; struct ieee80211_mgmt *m = (struct ieee80211_mgmt *) buf; struct wmm_tspec_element *t = (struct wmm_tspec_element *) m->u.action.u.wmm_action.variable; int len; hostapd_logger(hapd, addr, HOSTAPD_MODULE_IEEE80211, HOSTAPD_LEVEL_DEBUG, "action response - reason %d", status_code); os_memset(buf, 0, sizeof(buf)); m->frame_control = IEEE80211_FC(WLAN_FC_TYPE_MGMT, WLAN_FC_STYPE_ACTION); os_memcpy(m->da, addr, ETH_ALEN); os_memcpy(m->sa, hapd->own_addr, ETH_ALEN); os_memcpy(m->bssid, hapd->own_addr, ETH_ALEN); m->u.action.category = WLAN_ACTION_WMM; m->u.action.u.wmm_action.action_code = action_code; m->u.action.u.wmm_action.dialog_token = dialogue_token; m->u.action.u.wmm_action.status_code = status_code; os_memcpy(t, tspec, sizeof(struct wmm_tspec_element)); len = ((u8 *) (t + 1)) - buf; if (hostapd_drv_send_mlme(hapd, m, len, 0, NULL, 0, 0) < 0) wpa_printf(MSG_INFO, "wmm_send_action: send failed"); } int wmm_process_tspec(struct wmm_tspec_element *tspec) { u64 medium_time; unsigned int pps, duration; unsigned int up, psb, dir, tid; u16 val, surplus; up = (tspec->ts_info[1] >> 3) & 0x07; psb = (tspec->ts_info[1] >> 2) & 0x01; dir = (tspec->ts_info[0] >> 5) & 0x03; tid = (tspec->ts_info[0] >> 1) & 0x0f; wpa_printf(MSG_DEBUG, "WMM: TS Info: UP=%d PSB=%d Direction=%d TID=%d", up, psb, dir, tid); val = le_to_host16(tspec->nominal_msdu_size); wpa_printf(MSG_DEBUG, "WMM: Nominal MSDU Size: %d%s", val & 0x7fff, val & 0x8000 ? " (fixed)" : ""); wpa_printf(MSG_DEBUG, "WMM: Mean Data Rate: %u bps", le_to_host32(tspec->mean_data_rate)); wpa_printf(MSG_DEBUG, "WMM: Minimum PHY Rate: %u bps", le_to_host32(tspec->minimum_phy_rate)); val = le_to_host16(tspec->surplus_bandwidth_allowance); wpa_printf(MSG_DEBUG, "WMM: Surplus Bandwidth Allowance: %u.%04u", val >> 13, 10000 * (val & 0x1fff) / 0x2000); val = le_to_host16(tspec->nominal_msdu_size); if (val == 0) { wpa_printf(MSG_DEBUG, "WMM: Invalid Nominal MSDU Size (0)"); return WMM_ADDTS_STATUS_INVALID_PARAMETERS; } /* pps = Ceiling((Mean Data Rate / 8) / Nominal MSDU Size) */ pps = ((le_to_host32(tspec->mean_data_rate) / 8) + val - 1) / val; wpa_printf(MSG_DEBUG, "WMM: Packets-per-second estimate for TSPEC: %d", pps); if (le_to_host32(tspec->minimum_phy_rate) < 1000000) { wpa_printf(MSG_DEBUG, "WMM: Too small Minimum PHY Rate"); return WMM_ADDTS_STATUS_INVALID_PARAMETERS; } duration = (le_to_host16(tspec->nominal_msdu_size) & 0x7fff) * 8 / (le_to_host32(tspec->minimum_phy_rate) / 1000000) + 50 /* FIX: proper SIFS + ACK duration */; /* unsigned binary number with an implicit binary point after the * leftmost 3 bits, i.e., 0x2000 = 1.0 */ surplus = le_to_host16(tspec->surplus_bandwidth_allowance); if (surplus <= 0x2000) { wpa_printf(MSG_DEBUG, "WMM: Surplus Bandwidth Allowance not " "greater than unity"); return WMM_ADDTS_STATUS_INVALID_PARAMETERS; } medium_time = (u64) surplus * pps * duration / 0x2000; wpa_printf(MSG_DEBUG, "WMM: Estimated medium time: %lu", (unsigned long) medium_time); /* * TODO: store list of granted (and still active) TSPECs and check * whether there is available medium time for this request. For now, * just refuse requests that would by themselves take very large * portion of the available bandwidth. */ if (medium_time > 750000) { wpa_printf(MSG_DEBUG, "WMM: Refuse TSPEC request for over " "75%% of available bandwidth"); return WMM_ADDTS_STATUS_REFUSED; } /* Convert to 32 microseconds per second unit */ tspec->medium_time = host_to_le16(medium_time / 32); return WMM_ADDTS_STATUS_ADMISSION_ACCEPTED; } static void wmm_addts_req(struct hostapd_data *hapd, const struct ieee80211_mgmt *mgmt, const struct wmm_tspec_element *tspec, size_t len) { const u8 *end = ((const u8 *) mgmt) + len; int res; struct wmm_tspec_element tspec_resp; if ((const u8 *) (tspec + 1) > end) { wpa_printf(MSG_DEBUG, "WMM: TSPEC overflow in ADDTS Request"); return; } wpa_printf(MSG_DEBUG, "WMM: ADDTS Request (Dialog Token %d) for TSPEC " "from " MACSTR, mgmt->u.action.u.wmm_action.dialog_token, MAC2STR(mgmt->sa)); os_memcpy(&tspec_resp, tspec, sizeof(struct wmm_tspec_element)); res = wmm_process_tspec(&tspec_resp); wpa_printf(MSG_DEBUG, "WMM: ADDTS processing result: %d", res); wmm_send_action(hapd, mgmt->sa, &tspec_resp, WMM_ACTION_CODE_ADDTS_RESP, mgmt->u.action.u.wmm_action.dialog_token, res); } void hostapd_wmm_action(struct hostapd_data *hapd, const struct ieee80211_mgmt *mgmt, size_t len) { int action_code; int left = len - IEEE80211_HDRLEN - 4; const u8 *pos = ((const u8 *) mgmt) + IEEE80211_HDRLEN + 4; struct ieee802_11_elems elems; struct sta_info *sta = ap_get_sta(hapd, mgmt->sa); /* check that the request comes from a valid station */ if (!sta || (sta->flags & (WLAN_STA_ASSOC | WLAN_STA_WMM)) != (WLAN_STA_ASSOC | WLAN_STA_WMM)) { hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211, HOSTAPD_LEVEL_DEBUG, "wmm action received is not from associated wmm" " station"); /* TODO: respond with action frame refused status code */ return; } if (left < 0) return; /* not a valid WMM Action frame */ /* extract the tspec info element */ if (ieee802_11_parse_elems(pos, left, &elems, 1) == ParseFailed) { hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211, HOSTAPD_LEVEL_DEBUG, "hostapd_wmm_action - could not parse wmm " "action"); /* TODO: respond with action frame invalid parameters status * code */ return; } if (!elems.wmm_tspec || elems.wmm_tspec_len != (sizeof(struct wmm_tspec_element) - 2)) { hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211, HOSTAPD_LEVEL_DEBUG, "hostapd_wmm_action - missing or wrong length " "tspec"); /* TODO: respond with action frame invalid parameters status * code */ return; } /* TODO: check the request is for an AC with ACM set, if not, refuse * request */ action_code = mgmt->u.action.u.wmm_action.action_code; switch (action_code) { case WMM_ACTION_CODE_ADDTS_REQ: wmm_addts_req(hapd, mgmt, (struct wmm_tspec_element *) (elems.wmm_tspec - 2), len); return; #if 0 /* TODO: needed for client implementation */ case WMM_ACTION_CODE_ADDTS_RESP: wmm_setup_request(hapd, mgmt, len); return; /* TODO: handle station teardown requests */ case WMM_ACTION_CODE_DELTS: wmm_teardown(hapd, mgmt, len); return; #endif } hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211, HOSTAPD_LEVEL_DEBUG, "hostapd_wmm_action - unknown action code %d", action_code); }