taglinefilesource code
IN_MULTICAST153net/inet/devinet.cif(IN_MULTICAST(ntohl(addr)))
IN_MULTICAST128net/inet/icmp.cif(atype==IS_BROADCAST || IN_MULTICAST(iph->daddr))
IN_MULTICAST44net/inet/ip.h#define MULTICAST(x)  (IN_MULTICAST(htonl(x)))