Insert TIM after DS Parameter only if DS IE exists

The update_BCNTIM() function was always adding a fixed +3 offset assuming that
the DS Parameter Set IE (length 3) was present. However, on 5 GHz beacons, the
DS IE is typically absent. As a result, TIM was inserted 3 bytes past the
correct offset, overwriting the first bytes of the following IE (usually RSN),
which led to corrupted RSN contents (e.g., “RSN ver 0x0501”) and failed
associations.

This patch fixes the issue by checking for the presence of _DSSET_IE_ using
rtw_get_ie() and adding the +3 offset only if the DS Parameter IE actually
exists.  This preserves RSN and other IEs, ensures correct beacon formatting on
5 GHz, and restores stable P2P and 5 GHz connectivity.

Signed-off-by: Duc Huynh BV <[email protected]>

Author: Duc Huynh BV

core/rtw_ap.c

@@ -132,7 +132,9 @@ static void update_BCNTIM(_adapter *padapter)
 				offset += tmp_len + 2;
 
 			/*DS Parameter Set IE, len=3*/
-			offset += 3;
+			p = rtw_get_ie(pie + _BEACON_IE_OFFSET_, _DSSET_IE_, &tmp_len, (pnetwork_mlmeext->IELength - _BEACON_IE_OFFSET_));
+			if (p !=  NULL)
+				offset += 3;
 
 			premainder_ie = pie + offset;