WNM: Add advertisement of BSS max idle period

If WNM is enabled for the build (CONFIG_WNM=y), add BSS max idle period
information to the (Re)Association Response frame from the AP and parse
this information on the station. For SME-in-wpa_supplicant case, add a
timer to handle periodic transmission of the keep-alive frame. The
actual request for the driver to transmit a frame is not yet
implemented.

Signed-hostap: Jouni Malinen <j@w1.fi>

hostapd/Makefile

@@ -169,6 +169,10 @@ ifdef CONFIG_IEEE80211N
 CFLAGS += -DCONFIG_IEEE80211N
 endif
 
+ifdef CONFIG_WNM
+CFLAGS += -DCONFIG_WNM
+endif
+
 include ../src/drivers/drivers.mak
 OBJS += $(DRV_AP_OBJS)
 CFLAGS += $(DRV_AP_CFLAGS)

hostapd/defconfig

@@ -136,6 +136,10 @@ CONFIG_IPV6=y
 # IEEE 802.11n (High Throughput) support
 #CONFIG_IEEE80211N=y
 
+# Wireless Network Management (IEEE Std 802.11v-2011)
+# Note: This is experimental and not complete implementation.
+#CONFIG_WNM=y
+
 # Remove debugging code that is printing out debug messages to stdout.
 # This can be used to reduce the size of the hostapd considerably if debugging
 # code is not needed.

src/ap/ieee802_11.c

@@ -876,6 +876,7 @@ static void send_assoc_resp(struct hostapd_data *hapd, struct sta_info *sta,
 #endif /* CONFIG_IEEE80211N */
 
 	p = hostapd_eid_ext_capab(hapd, p);
+	p = hostapd_eid_bss_max_idle_period(hapd, p);
 
 	if (sta->flags & WLAN_STA_WMM)
 		p = hostapd_eid_wmm(hapd, p);

src/ap/ieee802_11.h

@@ -72,5 +72,6 @@ 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);
 
 #endif /* IEEE802_11_H */

src/ap/ieee802_11_shared.c

@@ -1,6 +1,6 @@
 /*
  * hostapd / IEEE 802.11 Management
- * Copyright (c) 2002-2010, Jouni Malinen <j@w1.fi>
+ * Copyright (c) 2002-2012, Jouni Malinen <j@w1.fi>
  *
  * This software may be distributed under the terms of the BSD license.
  * See README for more details.
@@ -397,3 +397,31 @@ int hostapd_update_time_adv(struct hostapd_data *hapd)
 
 	return 0;
 }
+
+
+u8 * hostapd_eid_bss_max_idle_period(struct hostapd_data *hapd, u8 *eid)
+{
+	u8 *pos = eid;
+
+#ifdef CONFIG_WNM
+	if (hapd->conf->ap_max_inactivity > 0) {
+		unsigned int val;
+		*pos++ = WLAN_EID_BSS_MAX_IDLE_PERIOD;
+		*pos++ = 3;
+		val = hapd->conf->ap_max_inactivity;
+		if (val > 68000)
+			val = 68000;
+		val *= 1000;
+		val /= 1024;
+		if (val == 0)
+			val = 1;
+		if (val > 65535)
+			val = 65535;
+		WPA_PUT_LE16(pos, val);
+		pos += 2;
+		*pos++ = 0x00; /* TODO: Protected Keep-Alive Required */
+	}
+#endif /* CONFIG_WNM */
+
+	return pos;
+}

src/common/ieee802_11_common.c

@@ -1,6 +1,6 @@
 /*
  * IEEE 802.11 Common routines
- * Copyright (c) 2002-2009, Jouni Malinen <j@w1.fi>
+ * Copyright (c) 2002-2012, Jouni Malinen <j@w1.fi>
  *
  * This software may be distributed under the terms of the BSD license.
  * See README for more details.
@@ -262,6 +262,15 @@ ParseRes ieee802_11_parse_elems(const u8 *start, size_t len,
 			elems->interworking = pos;
 			elems->interworking_len = elen;
 			break;
+		case WLAN_EID_EXT_CAPAB:
+			elems->ext_capab = pos;
+			elems->ext_capab_len = elen;
+			break;
+		case WLAN_EID_BSS_MAX_IDLE_PERIOD:
+			if (elen < 3)
+				break;
+			elems->bss_max_idle_period = pos;
+			break;
 		default:
 			unknown++;
 			if (!show_errors)

src/common/ieee802_11_common.h

@@ -38,6 +38,8 @@ struct ieee802_11_elems {
 	const u8 *link_id;
 	const u8 *interworking;
 	const u8 *hs20;
+	const u8 *ext_capab;
+	const u8 *bss_max_idle_period;
 
 	u8 ssid_len;
 	u8 supp_rates_len;
@@ -65,6 +67,7 @@ struct ieee802_11_elems {
 	u8 p2p_len;
 	u8 interworking_len;
 	u8 hs20_len;
+	u8 ext_capab_len;
 };
 
 typedef enum { ParseOK = 0, ParseUnknown = 1, ParseFailed = -1 } ParseRes;

src/common/ieee802_11_defs.h

@@ -228,6 +228,7 @@
 #define WLAN_EID_20_40_BSS_INTOLERANT 73
 #define WLAN_EID_OVERLAPPING_BSS_SCAN_PARAMS 74
 #define WLAN_EID_MMIE 76
+#define WLAN_EID_BSS_MAX_IDLE_PERIOD 90
 #define WLAN_EID_TFS_REQ 91
 #define WLAN_EID_TFS_RESP 92
 #define WLAN_EID_WNMSLEEP 93

wpa_supplicant/Makefile

@@ -722,6 +722,10 @@ ifdef CONFIG_IEEE80211N
 CFLAGS += -DCONFIG_IEEE80211N
 endif
 
+ifdef CONFIG_WNM
+CFLAGS += -DCONFIG_WNM
+endif
+
 ifdef NEED_AP_MLME
 OBJS += ../src/ap/wmm.o
 OBJS += ../src/ap/ap_list.o

wpa_supplicant/defconfig

@@ -476,6 +476,10 @@ CONFIG_PEERKEY=y
 # IEEE 802.11n (High Throughput) support (mainly for AP mode)
 #CONFIG_IEEE80211N=y
 
+# Wireless Network Management (IEEE Std 802.11v-2011)
+# Note: This is experimental and not complete implementation.
+#CONFIG_WNM=y
+
 # Interworking (IEEE 802.11u)
 # This can be used to enable functionality to improve interworking with
 # external networks (GAS/ANQP to learn more about the networks and network

wpa_supplicant/events.c

@@ -103,6 +103,8 @@ void wpa_supplicant_mark_disassoc(struct wpa_supplicant *wpa_s)
 {
 	int bssid_changed;
 
+	wnm_bss_keep_alive_deinit(wpa_s);
+
 #ifdef CONFIG_IBSS_RSN
 	ibss_rsn_deinit(wpa_s->ibss_rsn);
 	wpa_s->ibss_rsn = NULL;
@@ -1200,6 +1202,78 @@ static void wpa_supplicant_event_scan_results(struct wpa_supplicant *wpa_s,
 #endif /* CONFIG_NO_SCAN_PROCESSING */
 
 
+#ifdef CONFIG_WNM
+
+static void wnm_bss_keep_alive(void *eloop_ctx, void *sock_ctx)
+{
+	struct wpa_supplicant *wpa_s = eloop_ctx;
+
+	if (wpa_s->wpa_state < WPA_ASSOCIATED)
+		return;
+
+	wpa_printf(MSG_DEBUG, "WNM: Send keep-alive");
+	/* TODO: could skip this if normal data traffic has been sent */
+	/* TODO: send keep alive frame - better use some short unicast data
+	 * frame that gets protected if PTK is set */
+
+	if (wpa_s->sme.bss_max_idle_period) {
+		unsigned int msec;
+		msec = wpa_s->sme.bss_max_idle_period * 1024; /* times 1000 */
+		if (msec > 100)
+			msec -= 100;
+		eloop_register_timeout(msec / 1000, msec % 1000 * 1000,
+				       wnm_bss_keep_alive, wpa_s, NULL);
+	}
+}
+
+
+static void wnm_process_assoc_resp(struct wpa_supplicant *wpa_s,
+				   const u8 *ies, size_t ies_len)
+{
+	struct ieee802_11_elems elems;
+
+	if (ies == NULL)
+		return;
+
+	if (ieee802_11_parse_elems(ies, ies_len, &elems, 1) == ParseFailed)
+		return;
+
+#ifdef CONFIG_SME
+	if (elems.bss_max_idle_period) {
+		unsigned int msec;
+		wpa_s->sme.bss_max_idle_period =
+			WPA_GET_LE16(elems.bss_max_idle_period);
+		wpa_printf(MSG_DEBUG, "WNM: BSS Max Idle Period: %u (* 1000 "
+			   "TU)%s", wpa_s->sme.bss_max_idle_period,
+			   (elems.bss_max_idle_period[2] & 0x01) ?
+			   " (protected keep-live required)" : "");
+		if (wpa_s->sme.bss_max_idle_period == 0)
+			wpa_s->sme.bss_max_idle_period = 1;
+		if (wpa_s->drv_flags & WPA_DRIVER_FLAGS_SME) {
+			eloop_cancel_timeout(wnm_bss_keep_alive, wpa_s, NULL);
+			 /* msec times 1000 */
+			msec = wpa_s->sme.bss_max_idle_period * 1024;
+			if (msec > 100)
+				msec -= 100;
+			eloop_register_timeout(msec / 1000, msec % 1000 * 1000,
+					       wnm_bss_keep_alive, wpa_s,
+					       NULL);
+		}
+	}
+#endif /* CONFIG_SME */
+}
+
+#endif /* CONFIG_WNM */
+
+
+void wnm_bss_keep_alive_deinit(struct wpa_supplicant *wpa_s)
+{
+#ifdef CONFIG_WNM
+	eloop_cancel_timeout(wnm_bss_keep_alive, wpa_s, NULL);
+#endif /* CONFIG_WNM */
+}
+
+
 static int wpa_supplicant_event_associnfo(struct wpa_supplicant *wpa_s,
 					  union wpa_event_data *data)
 {
@@ -1217,6 +1291,10 @@ static int wpa_supplicant_event_associnfo(struct wpa_supplicant *wpa_s,
 		wpa_tdls_assoc_resp_ies(wpa_s->wpa, data->assoc_info.resp_ies,
 					data->assoc_info.resp_ies_len);
 #endif /* CONFIG_TDLS */
+#ifdef CONFIG_WNM
+		wnm_process_assoc_resp(wpa_s, data->assoc_info.resp_ies,
+				       data->assoc_info.resp_ies_len);
+#endif /* CONFIG_WNM */
 	}
 	if (data->assoc_info.beacon_ies)
 		wpa_hexdump(MSG_DEBUG, "beacon_ies",

wpa_supplicant/wpa_supplicant.c

@@ -449,6 +449,8 @@ static void wpa_supplicant_cleanup(struct wpa_supplicant *wpa_s)
 
 	os_free(wpa_s->bssid_filter);
 	wpa_s->bssid_filter = NULL;
+
+	wnm_bss_keep_alive_deinit(wpa_s);
 }
 
 

wpa_supplicant/wpa_supplicant_i.h

@@ -423,6 +423,7 @@ struct wpa_supplicant {
 		struct os_time sa_query_start;
 		u8 sched_obss_scan;
 		u16 obss_scan_int;
+		u16 bss_max_idle_period;
 	} sme;
 #endif /* CONFIG_SME */
 
@@ -664,6 +665,7 @@ int wpa_supplicant_connect(struct wpa_supplicant *wpa_s,
 			   struct wpa_ssid *ssid);
 void wpa_supplicant_stop_countermeasures(void *eloop_ctx, void *sock_ctx);
 void wpa_supplicant_delayed_mic_error_report(void *eloop_ctx, void *sock_ctx);
+void wnm_bss_keep_alive_deinit(struct wpa_supplicant *wpa_s);
 
 /* eap_register.c */
 int eap_register_methods(void);