From 4b08d1b6a994dbb593557bd2095ba4f0c3c47819 Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg@intel.com>
Date: Fri, 30 Aug 2019 14:24:51 +0300
Subject: [PATCH] mac80211: IBSS: send deauth when expiring inactive STAs

When we expire an inactive station, try to send it a deauth. This
helps if it's actually still around, and just has issues with
beacon distribution (or we do), and it will not also remove us.
Then, if we have shared state, this may not be reset properly,
causing problems; for example, we saw a case where aggregation
sessions weren't removed properly (due to the TX start being
offloaded to firmware and it relying on deauth for stop), causing
a lot of traffic to get lost due to the SN reset after remove/add
of the peer.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/20190830112451.21655-9-luca@coelho.fi
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 net/mac80211/ibss.c        |  8 ++++++++
 net/mac80211/ieee80211_i.h |  3 ++-
 net/mac80211/mlme.c        | 11 ++++++-----
 net/mac80211/util.c        |  5 +++--
 4 files changed, 19 insertions(+), 8 deletions(-)

--- a/net/mac80211/ibss.c
+++ b/net/mac80211/ibss.c
@@ -1253,6 +1253,7 @@ void ieee80211_ibss_rx_no_sta(struct iee
 
 static void ieee80211_ibss_sta_expire(struct ieee80211_sub_if_data *sdata)
 {
+	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 	struct ieee80211_local *local = sdata->local;
 	struct sta_info *sta, *tmp;
 	unsigned long exp_time = IEEE80211_IBSS_INACTIVITY_LIMIT;
@@ -1269,10 +1270,17 @@ static void ieee80211_ibss_sta_expire(st
 		if (time_is_before_jiffies(last_active + exp_time) ||
 		    (time_is_before_jiffies(last_active + exp_rsn) &&
 		     sta->sta_state != IEEE80211_STA_AUTHORIZED)) {
+			u8 frame_buf[IEEE80211_DEAUTH_FRAME_LEN];
+
 			sta_dbg(sta->sdata, "expiring inactive %sSTA %pM\n",
 				sta->sta_state != IEEE80211_STA_AUTHORIZED ?
 				"not authorized " : "", sta->sta.addr);
 
+			ieee80211_send_deauth_disassoc(sdata, sta->sta.addr,
+						       ifibss->bssid,
+						       IEEE80211_STYPE_DEAUTH,
+						       WLAN_REASON_DEAUTH_LEAVING,
+						       true, frame_buf);
 			WARN_ON(__sta_info_destroy(sta));
 		}
 	}
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -2071,7 +2071,8 @@ void ieee80211_send_auth(struct ieee8021
 			 const u8 *da, const u8 *key, u8 key_len, u8 key_idx,
 			 u32 tx_flags);
 void ieee80211_send_deauth_disassoc(struct ieee80211_sub_if_data *sdata,
-				    const u8 *bssid, u16 stype, u16 reason,
+				    const u8 *da, const u8 *bssid,
+				    u16 stype, u16 reason,
 				    bool send_frame, u8 *frame_buf);
 
 enum {
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -2203,8 +2203,9 @@ static void ieee80211_set_disassoc(struc
 		    !ifmgd->have_beacon)
 			drv_mgd_prepare_tx(sdata->local, sdata, 0);
 
-		ieee80211_send_deauth_disassoc(sdata, ifmgd->bssid, stype,
-					       reason, tx, frame_buf);
+		ieee80211_send_deauth_disassoc(sdata, ifmgd->bssid,
+					       ifmgd->bssid, stype, reason,
+					       tx, frame_buf);
 	}
 
 	/* flush out frame - make sure the deauth was actually sent */
@@ -4369,7 +4370,7 @@ void ieee80211_mgd_quiesce(struct ieee80
 		 * cfg80211 won't know and won't actually abort those attempts,
 		 * thus we need to do that ourselves.
 		 */
-		ieee80211_send_deauth_disassoc(sdata, bssid,
+		ieee80211_send_deauth_disassoc(sdata, bssid, bssid,
 					       IEEE80211_STYPE_DEAUTH,
 					       WLAN_REASON_DEAUTH_LEAVING,
 					       false, frame_buf);
@@ -5349,7 +5350,7 @@ int ieee80211_mgd_deauth(struct ieee8021
 			   ieee80211_get_reason_code_string(req->reason_code));
 
 		drv_mgd_prepare_tx(sdata->local, sdata, 0);
-		ieee80211_send_deauth_disassoc(sdata, req->bssid,
+		ieee80211_send_deauth_disassoc(sdata, req->bssid, req->bssid,
 					       IEEE80211_STYPE_DEAUTH,
 					       req->reason_code, tx,
 					       frame_buf);
@@ -5369,7 +5370,7 @@ int ieee80211_mgd_deauth(struct ieee8021
 			   ieee80211_get_reason_code_string(req->reason_code));
 
 		drv_mgd_prepare_tx(sdata->local, sdata, 0);
-		ieee80211_send_deauth_disassoc(sdata, req->bssid,
+		ieee80211_send_deauth_disassoc(sdata, req->bssid, req->bssid,
 					       IEEE80211_STYPE_DEAUTH,
 					       req->reason_code, tx,
 					       frame_buf);
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -1433,7 +1433,8 @@ void ieee80211_send_auth(struct ieee8021
 }
 
 void ieee80211_send_deauth_disassoc(struct ieee80211_sub_if_data *sdata,
-				    const u8 *bssid, u16 stype, u16 reason,
+				    const u8 *da, const u8 *bssid,
+				    u16 stype, u16 reason,
 				    bool send_frame, u8 *frame_buf)
 {
 	struct ieee80211_local *local = sdata->local;
@@ -1444,7 +1445,7 @@ void ieee80211_send_deauth_disassoc(stru
 	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | stype);
 	mgmt->duration = 0; /* initialize only */
 	mgmt->seq_ctrl = 0; /* initialize only */
-	memcpy(mgmt->da, bssid, ETH_ALEN);
+	memcpy(mgmt->da, da, ETH_ALEN);
 	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 	memcpy(mgmt->bssid, bssid, ETH_ALEN);
 	/* u.deauth.reason_code == u.disassoc.reason_code */
