mac80211: add assoc-at support

Report timestamp for when sta becomes associated.
Signed-off-by: Ben Greear <greearb@candelatech.com>
Link: https://lore.kernel.org/r/20190809180001.26393-2-greearb@candelatech.com
[fix ktime_get_boot_ns() to ktime_get_boottime_ns(), assoc_at type to u64]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/sta_info.c

@@ -1961,6 +1961,7 @@ int sta_info_move_state(struct sta_info *sta,
 	case IEEE80211_STA_ASSOC:
 		if (sta->sta_state == IEEE80211_STA_AUTH) {
 			set_bit(WLAN_STA_ASSOC, &sta->_flags);
+			sta->assoc_at = ktime_get_boottime_ns();
 			ieee80211_recalc_min_chandef(sta->sdata);
 			if (!sta->sta.support_p2p_ps)
 				ieee80211_recalc_p2p_go_ps_allowed(sta->sdata);
@@ -2190,6 +2191,7 @@ void sta_set_sinfo(struct sta_info *sta, struct station_info *sinfo,
 			 BIT_ULL(NL80211_STA_INFO_STA_FLAGS) |
 			 BIT_ULL(NL80211_STA_INFO_BSS_PARAM) |
 			 BIT_ULL(NL80211_STA_INFO_CONNECTED_TIME) |
+			 BIT_ULL(NL80211_STA_INFO_ASSOC_AT_BOOTTIME) |
 			 BIT_ULL(NL80211_STA_INFO_RX_DROP_MISC);
 
 	if (sdata->vif.type == NL80211_IFTYPE_STATION) {
@@ -2198,6 +2200,7 @@ void sta_set_sinfo(struct sta_info *sta, struct station_info *sinfo,
 	}
 
 	sinfo->connected_time = ktime_get_seconds() - sta->last_connected;
+	sinfo->assoc_at = sta->assoc_at;
 	sinfo->inactive_time =
 		jiffies_to_msecs(jiffies - ieee80211_sta_last_active(sta));
 

net/mac80211/sta_info.h

@@ -466,6 +466,7 @@ struct ieee80211_sta_rx_stats {
  *	the station when it leaves powersave or polls for frames
  * @driver_buffered_tids: bitmap of TIDs the driver has data buffered on
  * @txq_buffered_tids: bitmap of TIDs that mac80211 has txq data buffered on
+ * @assoc_at: clock boottime (in ns) of last association
  * @last_connected: time (in seconds) when a station got connected
  * @last_seq_ctrl: last received seq/frag number from this STA (per TID
  *	plus one for non-QoS frames)
@@ -562,6 +563,7 @@ struct sta_info {
 	unsigned long driver_buffered_tids;
 	unsigned long txq_buffered_tids;
 
+	u64 assoc_at;
 	long last_connected;
 
 	/* Updated from RX path only, no locking requirements */