Add is_multicast_ether_addr()

This helper function can be used to check whether a MAC address is a
multicast (including broadcast) address.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>

src/utils/common.h

@@ -518,6 +518,11 @@ static inline int is_broadcast_ether_addr(const u8 *a)
 	return (a[0] & a[1] & a[2] & a[3] & a[4] & a[5]) == 0xff;
 }
 
+static inline int is_multicast_ether_addr(const u8 *a)
+{
+	return a[0] & 0x01;
+}
+
 #define broadcast_ether_addr (const u8 *) "\xff\xff\xff\xff\xff\xff"
 
 #include "wpa_debug.h"