WNM: AP configuration to allow BSS max idle period requests

Add a new hostapd configuration parameter max_acceptable_idle_period to
allow the AP to accept per-STA requested BSS max idle periods.

Signed-off-by: Jouni Malinen <quic_jouni@quicinc.com>

hostapd/config_file.c

@@ -2558,6 +2558,8 @@ static int hostapd_config_fill(struct hostapd_config *conf,
 			return 1;
 		}
 		bss->bss_max_idle = val;
+	} else if (os_strcmp(buf, "max_acceptable_idle_period") == 0) {
+		bss->max_acceptable_idle_period = atoi(pos);
 	} else if (os_strcmp(buf, "no_disconnect_on_group_keyerror") == 0) {
 		int val = atoi(pos);
 

hostapd/hostapd.conf

@@ -530,6 +530,11 @@ wmm_ac_vo_acm=0
 #     period and require STAs to use protected keep-alive frames)
 #bss_max_idle=1
 #
+# Maximum acceptable BSS maximum idle period
+# If this is set to a nonzero value, the AP allows STAs to request different
+# maximum idle period values. This is in the units to 1000 TUs (1.024 s)
+#max_acceptable_idle_period=600
+#
 # Allow STA to skip group key handshake without getting disconnection when
 # BSS max idle period management is enabled.
 # 0 = disconnect STA if it does not reply to group key handshake (default)

src/ap/ap_config.h

@@ -466,6 +466,7 @@ struct hostapd_bss_config {
 
 	int ap_max_inactivity;
 	int bss_max_idle;
+	int max_acceptable_idle_period;
 	bool no_disconnect_on_group_keyerror;
 	int ignore_broadcast_ssid;
 	int no_probe_resp_if_max_sta;

src/ap/ctrl_iface_ap.c

@@ -277,6 +277,14 @@ static int hostapd_ctrl_iface_sta_mib(struct hostapd_data *hapd,
 		return len;
 	len += ret;
 
+	if (sta->max_idle_period) {
+		ret = os_snprintf(buf + len, buflen - len,
+				  "max_idle_period=%d\n", sta->max_idle_period);
+		if (os_snprintf_error(buflen - len, ret))
+			return len;
+		len += ret;
+	}
+
 	res = ieee802_11_get_mib_sta(hapd, sta, buf + len, buflen - len);
 	if (res >= 0)
 		len += res;

src/ap/ieee802_11.c

@@ -4328,6 +4328,19 @@ static int __check_assoc_ies(struct hostapd_data *hapd, struct sta_info *sta,
 		sta->power_capab = 0;
 	}
 
+	if (elems->bss_max_idle_period &&
+	    hapd->conf->max_acceptable_idle_period) {
+		u16 req;
+
+		req = WPA_GET_LE16(elems->bss_max_idle_period);
+		if (req <= hapd->conf->max_acceptable_idle_period)
+			sta->max_idle_period = req;
+		else if (hapd->conf->max_acceptable_idle_period >
+			 hapd->conf->ap_max_inactivity)
+			sta->max_idle_period =
+				hapd->conf->max_acceptable_idle_period;
+	}
+
 	return WLAN_STATUS_SUCCESS;
 }
 
@@ -4902,7 +4915,7 @@ static u16 send_assoc_resp(struct hostapd_data *hapd, struct sta_info *sta,
 #endif /* CONFIG_IEEE80211AX */
 
 	p = hostapd_eid_ext_capab(hapd, p, false);
-	p = hostapd_eid_bss_max_idle_period(hapd, p);
+	p = hostapd_eid_bss_max_idle_period(hapd, p, sta->max_idle_period);
 	if (sta && sta->qos_map_enabled)
 		p = hostapd_eid_qos_map_set(hapd, p);
 

src/ap/ieee802_11.h

@@ -147,7 +147,8 @@ u8 * hostapd_eid_time_adv(struct hostapd_data *hapd, u8 *eid);
 u8 * hostapd_eid_time_zone(struct hostapd_data *hapd, u8 *eid);
 int hostapd_update_time_adv(struct hostapd_data *hapd);
 void hostapd_client_poll_ok(struct hostapd_data *hapd, const u8 *addr);
-u8 * hostapd_eid_bss_max_idle_period(struct hostapd_data *hapd, u8 *eid);
+u8 * hostapd_eid_bss_max_idle_period(struct hostapd_data *hapd, u8 *eid,
+				     u16 value);
 
 int auth_sae_init_committed(struct hostapd_data *hapd, struct sta_info *sta);
 #ifdef CONFIG_SAE

src/ap/ieee802_11_shared.c

@@ -737,7 +737,8 @@ int hostapd_update_time_adv(struct hostapd_data *hapd)
 }
 
 
-u8 * hostapd_eid_bss_max_idle_period(struct hostapd_data *hapd, u8 *eid)
+u8 * hostapd_eid_bss_max_idle_period(struct hostapd_data *hapd, u8 *eid,
+				     u16 value)
 {
 	u8 *pos = eid;
 
@@ -756,6 +757,8 @@ u8 * hostapd_eid_bss_max_idle_period(struct hostapd_data *hapd, u8 *eid)
 			val = 1;
 		if (val > 65535)
 			val = 65535;
+		if (value)
+			val = value;
 		WPA_PUT_LE16(pos, val);
 		pos += 2;
 		/* Set the Protected Keep-Alive Required bit based on

src/ap/sta_info.c

@@ -532,6 +532,7 @@ void ap_handle_timer(void *eloop_ctx, void *timeout_ctx)
 	struct sta_info *sta = timeout_ctx;
 	unsigned long next_time = 0;
 	int reason;
+	int max_inactivity = hapd->conf->ap_max_inactivity;
 
 	wpa_printf(MSG_DEBUG, "%s: %s: " MACSTR " flags=0x%x timeout_next=%d",
 		   hapd->conf->iface, __func__, MAC2STR(sta->addr), sta->flags,
@@ -544,6 +545,9 @@ void ap_handle_timer(void *eloop_ctx, void *timeout_ctx)
 		return;
 	}
 
+	if (sta->max_idle_period)
+		max_inactivity = (sta->max_idle_period * 1024 + 999) / 1000;
+
 	if ((sta->flags & WLAN_STA_ASSOC) &&
 	    (sta->timeout_next == STA_NULLFUNC ||
 	     sta->timeout_next == STA_DISASSOC)) {
@@ -565,7 +569,7 @@ void ap_handle_timer(void *eloop_ctx, void *timeout_ctx)
 			 * Anyway, try again after the next inactivity timeout,
 			 * but do not disconnect the station now.
 			 */
-			next_time = hapd->conf->ap_max_inactivity + fuzz;
+			next_time = max_inactivity + fuzz;
 		} else if (inactive_sec == -ENOENT) {
 			wpa_msg(hapd->msg_ctx, MSG_DEBUG,
 				"Station " MACSTR " has lost its driver entry",
@@ -574,20 +578,19 @@ void ap_handle_timer(void *eloop_ctx, void *timeout_ctx)
 			/* Avoid sending client probe on removed client */
 			sta->timeout_next = STA_DISASSOC;
 			goto skip_poll;
-		} else if (inactive_sec < hapd->conf->ap_max_inactivity) {
+		} else if (inactive_sec < max_inactivity) {
 			/* station activity detected; reset timeout state */
 			wpa_msg(hapd->msg_ctx, MSG_DEBUG,
 				"Station " MACSTR " has been active %is ago",
 				MAC2STR(sta->addr), inactive_sec);
 			sta->timeout_next = STA_NULLFUNC;
-			next_time = hapd->conf->ap_max_inactivity + fuzz -
-				inactive_sec;
+			next_time = max_inactivity + fuzz - inactive_sec;
 		} else {
 			wpa_msg(hapd->msg_ctx, MSG_DEBUG,
 				"Station " MACSTR " has been "
 				"inactive too long: %d sec, max allowed: %d",
 				MAC2STR(sta->addr), inactive_sec,
-				hapd->conf->ap_max_inactivity);
+				max_inactivity);
 
 			if (hapd->conf->skip_inactivity_poll)
 				sta->timeout_next = STA_DISASSOC;
@@ -603,7 +606,7 @@ void ap_handle_timer(void *eloop_ctx, void *timeout_ctx)
 		/* data nullfunc frame poll did not produce TX errors; assume
 		 * station ACKed it */
 		sta->timeout_next = STA_NULLFUNC;
-		next_time = hapd->conf->ap_max_inactivity;
+		next_time = max_inactivity;
 	}
 
 skip_poll:
@@ -791,6 +794,7 @@ struct sta_info * ap_sta_add(struct hostapd_data *hapd, const u8 *addr)
 {
 	struct sta_info *sta;
 	int i;
+	int max_inactivity = hapd->conf->ap_max_inactivity;
 
 	sta = ap_get_sta(hapd, addr);
 	if (sta)
@@ -824,12 +828,15 @@ struct sta_info * ap_sta_add(struct hostapd_data *hapd, const u8 *addr)
 	}
 	sta->supported_rates_len = i;
 
+	if (sta->max_idle_period)
+		max_inactivity = (sta->max_idle_period * 1024 + 999) / 1000;
+
 	if (!(hapd->iface->drv_flags & WPA_DRIVER_FLAGS_INACTIVITY_TIMER)) {
 		wpa_printf(MSG_DEBUG, "%s: register ap_handle_timer timeout "
 			   "for " MACSTR " (%d seconds - ap_max_inactivity)",
 			   __func__, MAC2STR(addr),
-			   hapd->conf->ap_max_inactivity);
-		eloop_register_timeout(hapd->conf->ap_max_inactivity, 0,
+			   max_inactivity);
+		eloop_register_timeout(max_inactivity, 0,
 				       ap_handle_timer, hapd, sta);
 	}
 

src/ap/sta_info.h

@@ -332,6 +332,9 @@ struct sta_info {
 	struct mld_info mld_info;
 	u8 mld_assoc_link_id;
 #endif /* CONFIG_IEEE80211BE */
+
+	u16 max_idle_period; /* if nonzero, the granted BSS max idle period in
+			      * units of 1000 TUs */
 };