Add support for Time Advertisement

This adds preliminary support for IEEE 802.11v Time Advertisement
mechanism with UTC TSF offset.

hostapd/config_file.c

@@ -2092,6 +2092,20 @@ struct hostapd_config * hostapd_config_read(const char *fname)
 			extern int rsn_testing;
 			rsn_testing = atoi(pos);
 #endif /* CONFIG_RSN_TESTING */
+		} else if (os_strcmp(buf, "time_advertisement") == 0) {
+			bss->time_advertisement = atoi(pos);
+		} else if (os_strcmp(buf, "time_zone") == 0) {
+			size_t tz_len = os_strlen(pos);
+			if (tz_len < 4 || tz_len > 255) {
+				wpa_printf(MSG_DEBUG, "Line %d: invalid "
+					   "time_zone", line);
+				errors++;
+				continue;
+			}
+			os_free(bss->time_zone);
+			bss->time_zone = os_strdup(pos);
+			if (bss->time_zone == NULL)
+				errors++;
 #ifdef CONFIG_INTERWORKING
 		} else if (os_strcmp(buf, "interworking") == 0) {
 			bss->interworking = atoi(pos);

hostapd/hostapd.conf

@@ -1023,6 +1023,17 @@ own_ip_addr=127.0.0.1
 # Prohibit use of TDLS Channel Switching in this BSS
 #tdls_prohibit_chan_switch=1
 
+##### IEEE 802.11v-2011 #######################################################
+
+# Time advertisement
+# 0 = disabled (default)
+# 2 = UTC time at which the TSF timer is 0
+#time_advertisement=2
+
+# Local time zone as specified in 8.3 of IEEE Std 1003.1-2004:
+# stdoffset[dst[offset][,start[/time],end[/time]]]
+#time_zone=EST5
+
 ##### IEEE 802.11u-2011 #######################################################
 
 # Enable Interworking service

src/ap/ap_config.c

@@ -426,6 +426,8 @@ static void hostapd_config_free_bss(struct hostapd_bss_config *conf)
 		ssid->dyn_vlan_keys = NULL;
 	}
 
+	os_free(conf->time_zone);
+
 #ifdef CONFIG_IEEE80211R
 	{
 		struct ft_remote_r0kh *r0kh, *r0kh_prev;

src/ap/ap_config.h

@@ -342,6 +342,10 @@ struct hostapd_bss_config {
 	int tdls;
 	int disable_11n;
 
+	/* IEEE 802.11v */
+	int time_advertisement;
+	char *time_zone;
+
 	/* IEEE 802.11u - Interworking */
 	int interworking;
 	int access_network_type;

src/ap/ap_drv_ops.c

@@ -51,6 +51,20 @@ int hostapd_build_ap_extra_ies(struct hostapd_data *hapd,
 
 	*beacon_ret = *proberesp_ret = *assocresp_ret = NULL;
 
+	pos = buf;
+	pos = hostapd_eid_time_adv(hapd, pos);
+	if (pos != buf) {
+		if (wpabuf_resize(&beacon, pos - buf) != 0)
+			goto fail;
+		wpabuf_put_data(beacon, buf, pos - buf);
+	}
+	pos = hostapd_eid_time_zone(hapd, pos);
+	if (pos != buf) {
+		if (wpabuf_resize(&proberesp, pos - buf) != 0)
+			goto fail;
+		wpabuf_put_data(proberesp, buf, pos - buf);
+	}
+
 	pos = buf;
 	pos = hostapd_eid_ext_capab(hapd, pos);
 	if (pos != buf) {

src/ap/beacon.c

@@ -357,6 +357,9 @@ void handle_probe_req(struct hostapd_data *hapd,
 
 	pos = hostapd_eid_ext_capab(hapd, pos);
 
+	pos = hostapd_eid_time_adv(hapd, pos);
+	pos = hostapd_eid_time_zone(hapd, pos);
+
 	pos = hostapd_eid_interworking(hapd, pos);
 	pos = hostapd_eid_adv_proto(hapd, pos);
 	pos = hostapd_eid_roaming_consortium(hapd, pos);
@@ -494,6 +497,12 @@ void ieee802_11_set_beacon(struct hostapd_data *hapd)
 
 	tailpos = hostapd_eid_ext_capab(hapd, tailpos);
 
+	/*
+	 * TODO: Time Advertisement element should only be included in some
+	 * DTIM Beacon frames.
+	 */
+	tailpos = hostapd_eid_time_adv(hapd, tailpos);
+
 	tailpos = hostapd_eid_interworking(hapd, tailpos);
 	tailpos = hostapd_eid_adv_proto(hapd, tailpos);
 	tailpos = hostapd_eid_roaming_consortium(hapd, tailpos);

src/ap/hostapd.c

@@ -261,6 +261,8 @@ static void hostapd_cleanup(struct hostapd_data *hapd)
 	wpabuf_free(hapd->p2p_probe_resp_ie);
 	hapd->p2p_probe_resp_ie = NULL;
 #endif /* CONFIG_P2P */
+
+	wpabuf_free(hapd->time_adv);
 }
 
 

src/ap/hostapd.h

@@ -108,6 +108,10 @@ struct hostapd_data {
 
 	int parameter_set_count;
 
+	/* Time Advertisement */
+	u8 time_update_counter;
+	struct wpabuf *time_adv;
+
 #ifdef CONFIG_FULL_DYNAMIC_VLAN
 	struct full_dynamic_vlan *full_dynamic_vlan;
 #endif /* CONFIG_FULL_DYNAMIC_VLAN */

src/ap/ieee802_11.h

@@ -72,5 +72,8 @@ void ieee802_11_sa_query_action(struct hostapd_data *hapd,
 u8 * hostapd_eid_interworking(struct hostapd_data *hapd, u8 *eid);
 u8 * hostapd_eid_adv_proto(struct hostapd_data *hapd, u8 *eid);
 u8 * hostapd_eid_roaming_consortium(struct hostapd_data *hapd, u8 *eid);
+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);
 
 #endif /* IEEE802_11_H */

src/ap/ieee802_11_shared.c

@@ -20,6 +20,7 @@
 #include "sta_info.h"
 #include "ap_config.h"
 #include "ap_drv_ops.h"
+#include "ieee802_11.h"
 
 
 #ifdef CONFIG_IEEE80211W
@@ -188,6 +189,8 @@ u8 * hostapd_eid_ext_capab(struct hostapd_data *hapd, u8 *eid)
 	*pos++ = 0x00;
 
 	*pos = 0x00;
+	if (hapd->conf->time_advertisement == 2)
+		*pos |= 0x08; /* Bit 27 - UTC TSF Offset */
 	if (hapd->conf->interworking)
 		*pos |= 0x80; /* Bit 31 - Interworking */
 	pos++;
@@ -309,3 +312,91 @@ u8 * hostapd_eid_roaming_consortium(struct hostapd_data *hapd, u8 *eid)
 
 	return pos;
 }
+
+
+u8 * hostapd_eid_time_adv(struct hostapd_data *hapd, u8 *eid)
+{
+	if (hapd->conf->time_advertisement != 2)
+		return eid;
+
+	if (hapd->time_adv == NULL &&
+	    hostapd_update_time_adv(hapd) < 0)
+		return eid;
+
+	os_memcpy(eid, wpabuf_head(hapd->time_adv),
+		  wpabuf_len(hapd->time_adv));
+	eid += wpabuf_len(hapd->time_adv);
+
+	return eid;
+}
+
+
+u8 * hostapd_eid_time_zone(struct hostapd_data *hapd, u8 *eid)
+{
+	size_t len;
+
+	if (hapd->conf->time_advertisement != 2)
+		return eid;
+
+	len = os_strlen(hapd->conf->time_zone);
+
+	*eid++ = WLAN_EID_TIME_ZONE;
+	*eid++ = len;
+	os_memcpy(eid, hapd->conf->time_zone, len);
+	eid += len;
+
+	return eid;
+}
+
+
+int hostapd_update_time_adv(struct hostapd_data *hapd)
+{
+	const int elen = 2 + 1 + 10 + 5 + 1;
+	struct os_time t;
+	struct os_tm tm;
+	u8 *pos;
+
+	if (hapd->conf->time_advertisement != 2)
+		return 0;
+
+	if (os_get_time(&t) < 0 || os_gmtime(t.sec, &tm) < 0)
+		return -1;
+
+	if (!hapd->time_adv) {
+		hapd->time_adv = wpabuf_alloc(elen);
+		if (hapd->time_adv == NULL)
+			return -1;
+		pos = wpabuf_put(hapd->time_adv, elen);
+	} else
+		pos = wpabuf_mhead_u8(hapd->time_adv);
+
+	*pos++ = WLAN_EID_TIME_ADVERTISEMENT;
+	*pos++ = 1 + 10 + 5 + 1;
+
+	*pos++ = 2; /* UTC time at which the TSF timer is 0 */
+
+	/* Time Value at TSF 0 */
+	/* FIX: need to calculate this based on the current TSF value */
+	WPA_PUT_LE16(pos, tm.year); /* Year */
+	pos += 2;
+	*pos++ = tm.month; /* Month */
+	*pos++ = tm.day; /* Day of month */
+	*pos++ = tm.hour; /* Hours */
+	*pos++ = tm.min; /* Minutes */
+	*pos++ = tm.sec; /* Seconds */
+	WPA_PUT_LE16(pos, 0); /* Milliseconds (not used) */
+	pos += 2;
+	*pos++ = 0; /* Reserved */
+
+	/* Time Error */
+	/* TODO: fill in an estimate on the error */
+	*pos++ = 0;
+	*pos++ = 0;
+	*pos++ = 0;
+	*pos++ = 0;
+	*pos++ = 0;
+
+	*pos++ = hapd->time_update_counter++;
+
+	return 0;
+}

src/common/ieee802_11_defs.h

@@ -229,10 +229,12 @@
 #define WLAN_EID_RIC_DATA 57
 #define WLAN_EID_HT_OPERATION 61
 #define WLAN_EID_SECONDARY_CHANNEL_OFFSET 62
+#define WLAN_EID_TIME_ADVERTISEMENT 69
 #define WLAN_EID_20_40_BSS_COEXISTENCE 72
 #define WLAN_EID_20_40_BSS_INTOLERANT 73
 #define WLAN_EID_OVERLAPPING_BSS_SCAN_PARAMS 74
 #define WLAN_EID_MMIE 76
+#define WLAN_EID_TIME_ZONE 98
 #define WLAN_EID_LINK_ID 101
 #define WLAN_EID_INTERWORKING 107
 #define WLAN_EID_ADV_PROTO 108