nl80211: Work around mac80211 limitation on (re)auth when authenticated

mac80211 does not currently allow (re)authentication when we are already
authenticated. In order to work around this, force deauthentication if
nl80211 authentication command fails with EALREADY. Unfortunately, the
workaround code in driver_nl80211.c alone is not enough since the
following disconnection event would clear wpa_supplicant authentication
state. To handle this, add some code to restore authentication state
when using userspace SME.

This workaround will hopefully become unnecessary in some point should
mac80211 start accepting new authentication requests even when in
authenticated state.

src/drivers/driver_nl80211.c

@@ -2063,9 +2063,11 @@ static int wpa_driver_nl80211_authenticate(
 	int ret = -1, i;
 	struct nl_msg *msg;
 	enum nl80211_auth_type type;
+	int count = 0;
 
 	drv->associated = 0;
 
+retry:
 	msg = nlmsg_alloc();
 	if (!msg)
 		return -1;
@@ -2133,6 +2135,21 @@ static int wpa_driver_nl80211_authenticate(
 	if (ret) {
 		wpa_printf(MSG_DEBUG, "nl80211: MLME command failed: ret=%d "
 			   "(%s)", ret, strerror(-ret));
+		count++;
+		if (ret == -EALREADY && count == 1 && params->bssid) {
+			/*
+			 * mac80211 does not currently accept new
+			 * authentication if we are already authenticated. As a
+			 * workaround, force deauthentication and try again.
+			 */
+			wpa_printf(MSG_DEBUG, "nl80211: Retry authentication "
+				   "after forced deauthentication");
+			wpa_driver_nl80211_deauthenticate(
+				drv, params->bssid,
+				WLAN_REASON_PREV_AUTH_NOT_VALID);
+			nlmsg_free(msg);
+			goto retry;
+		}
 		goto nla_put_failure;
 	}
 	ret = 0;

wpa_supplicant/events.c

@@ -1065,6 +1065,13 @@ static void wpa_supplicant_event_assoc(struct wpa_supplicant *wpa_s,
 static void wpa_supplicant_event_disassoc(struct wpa_supplicant *wpa_s)
 {
 	const u8 *bssid;
+#ifdef CONFIG_SME
+	int authenticating;
+	u8 prev_pending_bssid[ETH_ALEN];
+
+	authenticating = wpa_s->wpa_state == WPA_AUTHENTICATING;
+	os_memcpy(prev_pending_bssid, wpa_s->pending_bssid, ETH_ALEN);
+#endif /* CONFIG_SME */
 
 	if (wpa_s->key_mgmt == WPA_KEY_MGMT_WPA_NONE) {
 		/*
@@ -1097,6 +1104,20 @@ static void wpa_supplicant_event_disassoc(struct wpa_supplicant *wpa_s)
 	}
 	wpa_supplicant_mark_disassoc(wpa_s);
 	bgscan_deinit(wpa_s);
+#ifdef CONFIG_SME
+	if (authenticating &&
+	    (wpa_s->drv_flags & WPA_DRIVER_FLAGS_SME)) {
+		/*
+		 * mac80211-workaround to force deauth on failed auth cmd,
+		 * requires us to remain in authenticating state to allow the
+		 * second authentication attempt to be continued properly.
+		 */
+		wpa_printf(MSG_DEBUG, "SME: Allow pending authentication to "
+			   "proceed after disconnection event");
+		wpa_supplicant_set_state(wpa_s, WPA_AUTHENTICATING);
+		os_memcpy(wpa_s->pending_bssid, prev_pending_bssid, ETH_ALEN);
+	}
+#endif /* CONFIG_SME */
 }