/*
* hostapd / WMM (Wi-Fi Multimedia)
* Copyright 2002-2003, Instant802 Networks, Inc.
* Copyright 2005-2006, Devicescape Software, Inc.
* Copyright (c) 2009, Jouni Malinen <j@w1.fi>
*
* 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"
/* TODO: maintain separate sequence and fragment numbers for each AC
* TODO: IGMP snooping to track which multicasts to forward - and use QOS-DATA
* if only WMM stations are receiving a certain group */
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);
}
/*
* 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);
int e;
if (!hapd->conf->wmm_enabled)
return eid;
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 =
&hapd->iconf->wmm_ac_params[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) < 0)
wpa_printf(MSG_INFO, "wmm_send_action: send failed");
}
int wmm_process_tspec(struct wmm_tspec_element *tspec)
{
int medium_time, pps, duration;
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 = surplus * pps * duration / 0x2000;
wpa_printf(MSG_DEBUG, "WMM: Estimated medium time: %u", 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,
struct wmm_tspec_element *tspec, size_t len)
{
const u8 *end = ((const u8 *) mgmt) + len;
int res;
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));
res = wmm_process_tspec(tspec);
wpa_printf(MSG_DEBUG, "WMM: ADDTS processing result: %d", res);
wmm_send_action(hapd, mgmt->sa, tspec, 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);
}