hostapd: Avoid key reinstallation in FT handshake am: 37df134b3b
am: 25375e40ec

Change-Id: Icf76497a2c6d0ca187b7c3115ff52f12606cb4d4
diff --git a/src/ap/ieee802_11.c b/src/ap/ieee802_11.c
index 6a373c5..45ecbfb 100644
--- a/src/ap/ieee802_11.c
+++ b/src/ap/ieee802_11.c
@@ -1774,6 +1774,7 @@
 {
 	struct ieee80211_ht_capabilities ht_cap;
 	struct ieee80211_vht_capabilities vht_cap;
+	int set = 1;
 
 	/*
 	 * Remove the STA entry to ensure the STA PS state gets cleared and
@@ -1781,9 +1782,18 @@
 	 * FT-over-the-DS, where a station re-associates back to the same AP but
 	 * skips the authentication flow, or if working with a driver that
 	 * does not support full AP client state.
+	 *
+	 * Skip this if the STA has already completed FT reassociation and the
+	 * TK has been configured since the TX/RX PN must not be reset to 0 for
+	 * the same key.
 	 */
-	if (!sta->added_unassoc)
+	if (!sta->added_unassoc &&
+	    (!(sta->flags & WLAN_STA_AUTHORIZED) ||
+	     !wpa_auth_sta_ft_tk_already_set(sta->wpa_sm))) {
 		hostapd_drv_sta_remove(hapd, sta->addr);
+		wpa_auth_sm_event(sta->wpa_sm, WPA_DRV_STA_REMOVED);
+		set = 0;
+	}
 
 #ifdef CONFIG_IEEE80211N
 	if (sta->flags & WLAN_STA_HT)
@@ -1805,11 +1815,11 @@
 			    sta->flags & WLAN_STA_HT ? &ht_cap : NULL,
 			    sta->flags & WLAN_STA_VHT ? &vht_cap : NULL,
 			    sta->flags | WLAN_STA_ASSOC, sta->qosinfo,
-			    sta->vht_opmode, sta->added_unassoc)) {
+			    sta->vht_opmode, set)) {
 		hostapd_logger(hapd, sta->addr,
 			       HOSTAPD_MODULE_IEEE80211, HOSTAPD_LEVEL_NOTICE,
 			       "Could not %s STA to kernel driver",
-			       sta->added_unassoc ? "set" : "add");
+			       set ? "set" : "add");
 
 		if (sta->added_unassoc) {
 			hostapd_drv_sta_remove(hapd, sta->addr);
diff --git a/src/ap/wpa_auth.c b/src/ap/wpa_auth.c
index 3587086..707971d 100644
--- a/src/ap/wpa_auth.c
+++ b/src/ap/wpa_auth.c
@@ -1745,6 +1745,9 @@
 #else /* CONFIG_IEEE80211R */
 		break;
 #endif /* CONFIG_IEEE80211R */
+	case WPA_DRV_STA_REMOVED:
+		sm->tk_already_set = FALSE;
+		return 0;
 	}
 
 #ifdef CONFIG_IEEE80211R
@@ -3250,6 +3253,14 @@
 }
 
 
+int wpa_auth_sta_ft_tk_already_set(struct wpa_state_machine *sm)
+{
+	if (!sm || !wpa_key_mgmt_ft(sm->wpa_key_mgmt))
+		return 0;
+	return sm->tk_already_set;
+}
+
+
 int wpa_auth_sta_clear_pmksa(struct wpa_state_machine *sm,
 			     struct rsn_pmksa_cache_entry *entry)
 {
diff --git a/src/ap/wpa_auth.h b/src/ap/wpa_auth.h
index 0de8d97..e66f08b 100644
--- a/src/ap/wpa_auth.h
+++ b/src/ap/wpa_auth.h
@@ -246,7 +246,7 @@
 	WPA_MGMT_FRAME_PROTECTION_VIOLATION, WPA_INVALID_MGMT_GROUP_CIPHER,
 	WPA_INVALID_MDIE, WPA_INVALID_PROTO
 };
-	
+
 int wpa_validate_wpa_ie(struct wpa_authenticator *wpa_auth,
 			struct wpa_state_machine *sm,
 			const u8 *wpa_ie, size_t wpa_ie_len,
@@ -267,7 +267,7 @@
 		 u8 *data, size_t data_len);
 enum wpa_event {
 	WPA_AUTH, WPA_ASSOC, WPA_DISASSOC, WPA_DEAUTH, WPA_REAUTH,
-	WPA_REAUTH_EAPOL, WPA_ASSOC_FT
+	WPA_REAUTH_EAPOL, WPA_ASSOC_FT, WPA_DRV_STA_REMOVED
 };
 void wpa_remove_ptk(struct wpa_state_machine *sm);
 int wpa_auth_sm_event(struct wpa_state_machine *sm, enum wpa_event event);
@@ -280,6 +280,7 @@
 int wpa_auth_get_pairwise(struct wpa_state_machine *sm);
 int wpa_auth_sta_key_mgmt(struct wpa_state_machine *sm);
 int wpa_auth_sta_wpa_version(struct wpa_state_machine *sm);
+int wpa_auth_sta_ft_tk_already_set(struct wpa_state_machine *sm);
 int wpa_auth_sta_clear_pmksa(struct wpa_state_machine *sm,
 			     struct rsn_pmksa_cache_entry *entry);
 struct rsn_pmksa_cache_entry *
diff --git a/src/ap/wpa_auth_ft.c b/src/ap/wpa_auth_ft.c
index 42242a5..e63b99a 100644
--- a/src/ap/wpa_auth_ft.c
+++ b/src/ap/wpa_auth_ft.c
@@ -780,6 +780,14 @@
 		return;
 	}
 
+	if (sm->tk_already_set) {
+		/* Must avoid TK reconfiguration to prevent clearing of TX/RX
+		 * PN in the driver */
+		wpa_printf(MSG_DEBUG,
+			   "FT: Do not re-install same PTK to the driver");
+		return;
+	}
+
 	/* FIX: add STA entry to kernel/driver here? The set_key will fail
 	 * most likely without this.. At the moment, STA entry is added only
 	 * after association has been completed. This function will be called
@@ -792,6 +800,7 @@
 
 	/* FIX: MLME-SetProtection.Request(TA, Tx_Rx) */
 	sm->pairwise_set = TRUE;
+	sm->tk_already_set = TRUE;
 }
 
 
@@ -898,6 +907,7 @@
 
 	sm->pairwise = pairwise;
 	sm->PTK_valid = TRUE;
+	sm->tk_already_set = FALSE;
 	wpa_ft_install_ptk(sm);
 
 	buflen = 2 + sizeof(struct rsn_mdie) + 2 + sizeof(struct rsn_ftie) +
diff --git a/src/ap/wpa_auth_i.h b/src/ap/wpa_auth_i.h
index 72b7eb3..7fd8f05 100644
--- a/src/ap/wpa_auth_i.h
+++ b/src/ap/wpa_auth_i.h
@@ -65,6 +65,7 @@
 	struct wpa_ptk PTK;
 	Boolean PTK_valid;
 	Boolean pairwise_set;
+	Boolean tk_already_set;
 	int keycount;
 	Boolean Pair;
 	struct wpa_key_replay_counter {