mac80211: 802.11w - Implement Association Comeback processing

When MFP is enabled, the AP does not allow a STA to associate if an
existing security association exists without first going through SA
Query process. When this happens, the association request is denied
with a new status code ("temporarily rejected") ans Association
Comeback IE is used to notify when the association may be tried again
(i.e., when the SA Query procedure has timed out).

Use the comeback time to update the mac80211 client MLME timer for
next association attempt to minimize waiting time if association is
temporarily rejected.

Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 5cd4303..963e047 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -653,6 +653,10 @@
 			elems->pwr_constr_elem = pos;
 			elems->pwr_constr_elem_len = elen;
 			break;
+		case WLAN_EID_ASSOC_COMEBACK_TIME:
+			elems->assoc_comeback = pos;
+			elems->assoc_comeback_len = elen;
+			break;
 		default:
 			break;
 		}