Denis Vlasenko wrote:

bcm43xx_rx() contains code to filter out packets from
foreign BSSes and decide whether to call ieee80211_rx
or ieee80211_rx_mgt. This is not bcm specific.

+/* Kernel doesn't have it, why? */
+static inline int is_mcast_or_bcast_ether_addr(const u8 *addr)
+{
+        return (0x01 & addr[0]);
+}

The same function exists in include/linux/etherdevice.h:

static inline int is_multicast_ether_addr(const u8 *addr)
{
        return (0x01 & addr[0]);
}