From c6eea2102020a426e589125e5a50e41978924cf5 Mon Sep 17 00:00:00 2001
From: oblique <psyberbits@gmail.com>
Date: Thu, 28 Aug 2014 21:28:36 +0300
Subject: [PATCH] Change MAC address only if needed

Some virtual interfaces have a different MAC address from their real
interfaces and their drivers disallow us to change it. In this case
we don't need to change the MAC address anyway.

With this we can avoid errors like 'RTNETLINK answers: Invalid argument'.
---
 create_ap | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/create_ap b/create_ap
index 8d9c062..11a8bae 100755
--- a/create_ap
+++ b/create_ap
@@ -488,7 +488,7 @@ if [[ $NO_VIRT -eq 0 ]]; then
         die "$VIRTDIEMSG"
     fi
     OLD_MACADDR=$(get_macaddr ${VWIFI_IFACE})
-    NEW_MACADDR=$(get_new_macaddr ${VWIFI_IFACE})
+    [[ ${OLD_MACADDR} == $(get_macaddr ${WIFI_IFACE}) ]] && NEW_MACADDR=$(get_new_macaddr ${VWIFI_IFACE})
     WIFI_IFACE=${VWIFI_IFACE}
 else
     [[ "$WIFI_IFACE" == "$INTERNET_IFACE" ]] && die "You can not share your connection from the same interface if you are using --no-virt option."
@@ -553,7 +553,7 @@ EOF
 fi
 
 # initialize WiFi interface
-if [[ $NO_VIRT -eq 0 ]]; then
+if [[ $NO_VIRT -eq 0 && -n "$NEW_MACADDR" ]]; then
     ip link set dev ${WIFI_IFACE} address ${NEW_MACADDR} || die "$VIRTDIEMSG"
 fi
 ip link set down dev ${WIFI_IFACE} || die "$VIRTDIEMSG"