WNM: Ignore WNM-Sleep Mode Response if WNM-Sleep Mode has not been used

The AP is not expected to send out a WNM-Sleep Mode Response frame
without the STA trying to use WNM-Sleep Mode. Drop such unexpected
responses to reduce unnecessary processing of the frame.

Signed-off-by: Jouni Malinen <j@w1.fi>

wpa_supplicant/ctrl_iface.c

@@ -6905,6 +6905,7 @@ static void wpa_supplicant_ctrl_iface_flush(struct wpa_supplicant *wpa_s)
 	}
 
 	eloop_cancel_timeout(wpas_network_reenabled, wpa_s, NULL);
+	wpa_s->wnmsleep_used = 0;
 }
 
 

wpa_supplicant/events.c

@@ -303,6 +303,7 @@ void wpa_supplicant_mark_disassoc(struct wpa_supplicant *wpa_s)
 	wpa_s->key_mgmt = 0;
 
 	wpas_rrm_reset(wpa_s);
+	wpa_s->wnmsleep_used = 0;
 }
 
 

wpa_supplicant/wnm_sta.c

@@ -139,6 +139,8 @@ int ieee802_11_send_wnmsleep_req(struct wpa_supplicant *wpa_s,
 	if (res < 0)
 		wpa_printf(MSG_DEBUG, "Failed to send WNM-Sleep Request "
 			   "(action=%d, intval=%d)", action, intval);
+	else
+		wpa_s->wnmsleep_used = 1;
 
 	os_free(wnmsleep_ie);
 	os_free(wnmtfs_ie);
@@ -255,6 +257,12 @@ static void ieee802_11_rx_wnmsleep_resp(struct wpa_supplicant *wpa_s,
 	const u8 *tfsresp_ie_end = NULL;
 	size_t left;
 
+	if (!wpa_s->wnmsleep_used) {
+		wpa_printf(MSG_DEBUG,
+			   "WNM: Ignore WNM-Sleep Mode Response frame since WNM-Sleep Mode has not been used in this association");
+		return;
+	}
+
 	if (len < 3)
 		return;
 	key_len_total = WPA_GET_LE16(frm + 1);

wpa_supplicant/wpa_supplicant_i.h

@@ -669,6 +669,7 @@ struct wpa_supplicant {
 	unsigned int reattach:1; /* reassociation to the same BSS requested */
 	unsigned int mac_addr_changed:1;
 	unsigned int added_vif:1;
+	unsigned int wnmsleep_used:1;
 
 	struct os_reltime last_mac_addr_change;
 	int last_mac_addr_style;