[PATCH 1/2] BSS: permit falling back to RSNOE for MLO

[Benjamin Berg]

From: Benjamin Berg <benjamin.berg at intel.com>

On the one hand, the WPA3 specification says that with MLO one should
use the RSNO2E. At the same time, in the Wi-Fi Alliance Forward
Compatibility tests 5.2.3.x the station is expected to do a fallback in
case none of the ciphers are supported.

Change the logic to allow a fallback to the RSN Override Element (RSNOE)
for MLO. Still left is the logic to check that an RSNX Override Element
is present in this case.

Signed-off-by: Benjamin Berg <benjamin.berg at intel.com>
---
 wpa_supplicant/bss.c | 29 +++++++++++++++++------------
 1 file changed, 17 insertions(+), 12 deletions(-)

diff --git a/wpa_supplicant/bss.c b/wpa_supplicant/bss.c
index 58adaf7449..c679688108 100644
--- a/wpa_supplicant/bss.c
+++ b/wpa_supplicant/bss.c
@@ -2244,31 +2244,36 @@ const u8 * wpa_bss_get_rsne(struct wpa_supplicant *wpa_s,
 			    bool mlo)
 {
 #ifndef CONFIG_NO_WPA
-	const u8 *ie;
-
 	if (wpas_rsn_overriding(wpa_s, ssid)) {
+		const u8 *ie;
+
 		if (!ssid)
 			ssid = wpa_s->current_ssid;
 
 		/* MLO cases for RSN overriding are required to use RSNE
-		 * Override 2 element and RSNXE Override element together. */
+		 * Override 2 element and RSNXE Override element together.
+		 * However, we are also expected to do a fallback, so for MLO,
+		 * accept either Override if the RSNXE override is present.
+		 */
 		ie = wpa_bss_get_vendor_ie(bss, RSNE_OVERRIDE_2_IE_VENDOR_TYPE);
+		if (!ie || !wpa_bss_supported_rsne(wpa_s, ssid, ie)) {
+			ie = wpa_bss_get_vendor_ie(bss,
+						   RSNE_OVERRIDE_IE_VENDOR_TYPE);
+			if (!ie || !wpa_bss_supported_rsne(wpa_s, ssid, ie))
+				ie = NULL;
+		}
+
 		if (mlo && ie &&
 		    !wpa_bss_get_vendor_ie(bss,
 					   RSNXE_OVERRIDE_IE_VENDOR_TYPE)) {
 			wpa_printf(MSG_DEBUG, "BSS " MACSTR
-				   " advertises RSNE Override 2 element without RSNXE Override element - ignore RSNE Override 2 element for MLO",
+				   " has no RSNX Override Element - ignore RSN Override for MLO",
 				   MAC2STR(bss->bssid));
-		} else if (ie && wpa_bss_supported_rsne(wpa_s, ssid, ie)) {
-			return ie;
+			ie = NULL;
 		}
 
-		if (!mlo) {
-			ie = wpa_bss_get_vendor_ie(
-				bss, RSNE_OVERRIDE_IE_VENDOR_TYPE);
-			if (ie && wpa_bss_supported_rsne(wpa_s, ssid, ie))
-				return ie;
-		}
+		if (ie)
+			return ie;
 	}
 #endif /* CONFIG_NO_WPA */
 
-- 
2.50.1