Restore find_interface_by_mac()

Shorewall/lib.base

@@ -598,6 +598,32 @@ chain_exists() # $1 = chain name
     qt $IPTABLES -L $1 -n
 }
 
+#
+# Find the interface with the passed MAC address
+#
+
+find_interface_by_mac() {
+    local mac
+    mac=$1 
+    local first 
+    local second
+    local rest
+    local dev
+
+    ip link list | while read first second rest; do
+	case $first in
+	    *:)
+                dev=$second
+		;;
+	    *)
+	        if [ "$second" = $mac ]; then
+		    echo ${dev%:}
+		    return
+		fi
+	esac
+    done
+}
+
 #
 # Find interface address--returns the first IP address assigned to the passed
 # device