[PATCH v3 2/2] Add a log message when GTK rekeying failed

[Günther Kelleter]

It can happen if the station is unreachable or sleeping longer than
the actual total GTK rekey timeout. To fix the latter case
wpa_group_update_count may be increased.

Signed-off-by: Günther Kelleter <guenther.kelleter at devolo.de>
---
 hostapd/hostapd.conf | 4 ++++
 src/ap/wpa_auth.c    | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/hostapd/hostapd.conf b/hostapd/hostapd.conf
index 3abbb2b..77ff2fe 100644
--- a/hostapd/hostapd.conf
+++ b/hostapd/hostapd.conf
@@ -1223,6 +1223,10 @@ own_ip_addr=127.0.0.1
 
 # The number of times Message 1 in the RSNA Group Key Handshake is retried
 # per GTK Handshake attempt.
+# This value should only be increased when stations are constantly
+# deauthenticated during GTK rekeying with the log message
+# "group key handshake failed...".
+# You should consider to also increase wpa_pairwise_update_count then.
 # (dot11RSNAConfigGroupUpdateCount)
 # range 1..4294967295; default: 4
 #wpa_group_update_count=4
diff --git a/src/ap/wpa_auth.c b/src/ap/wpa_auth.c
index be11621..76fb8ff 100644
--- a/src/ap/wpa_auth.c
+++ b/src/ap/wpa_auth.c
@@ -3127,6 +3127,10 @@ SM_STATE(WPA_PTK_GROUP, KEYERROR)
 		sm->group->GKeyDoneStations--;
 	sm->GUpdateStationKeys = FALSE;
 	sm->Disconnect = TRUE;
+	wpa_auth_vlogger(sm->wpa_auth, sm->addr, LOGGER_INFO,
+			 "group key handshake failed (%s) after %u tries",
+			 sm->wpa == WPA_VERSION_WPA ? "WPA" : "RSN",
+			 sm->wpa_auth->conf.wpa_group_update_count);
 }
 
 
-- 
2.10.2.101.g2cc9ff1