mac80211: order IEs in probe request correctly

In probe request frames, the VHT IEs should come before any
vendor IEs, but after interworking and similar, so add code
to order them correctly wrt. the IEs passed from userspace.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/util.c

@@ -1281,13 +1281,32 @@ int ieee80211_build_preq_ies(struct ieee80211_local *local, u8 *buffer,
 	 * that calculates local->scan_ies_len.
 	 */
 
-	/* add any remaining custom IEs */
+	/* insert custom IEs that go before VHT */
 	if (ie && ie_len) {
-		noffset = ie_len;
+		static const u8 before_vht[] = {
+			WLAN_EID_SSID,
+			WLAN_EID_SUPP_RATES,
+			WLAN_EID_REQUEST,
+			WLAN_EID_EXT_SUPP_RATES,
+			WLAN_EID_DS_PARAMS,
+			WLAN_EID_SUPPORTED_REGULATORY_CLASSES,
+			WLAN_EID_HT_CAPABILITY,
+			WLAN_EID_BSS_COEX_2040,
+			WLAN_EID_EXT_CAPABILITY,
+			WLAN_EID_SSID_LIST,
+			WLAN_EID_CHANNEL_USAGE,
+			WLAN_EID_INTERWORKING,
+			/* mesh ID can't happen here */
+			/* 60 GHz can't happen here right now */
+		};
+		noffset = ieee80211_ie_split(ie, ie_len,
+					     before_vht, ARRAY_SIZE(before_vht),
+					     offset);
 		if (end - pos < noffset - offset)
 			goto out_err;
 		memcpy(pos, ie + offset, noffset - offset);
 		pos += noffset - offset;
+		offset = noffset;
 	}
 
 	if (sband->vht_cap.vht_supported) {
@@ -1297,6 +1316,15 @@ int ieee80211_build_preq_ies(struct ieee80211_local *local, u8 *buffer,
 						 sband->vht_cap.cap);
 	}
 
+	/* add any remaining custom IEs */
+	if (ie && ie_len) {
+		noffset = ie_len;
+		if (end - pos < noffset - offset)
+			goto out_err;
+		memcpy(pos, ie + offset, noffset - offset);
+		pos += noffset - offset;
+	}
+
 	return pos - buffer;
  out_err:
 	WARN_ONCE(1, "not enough space for preq IEs\n");