/* inet_netof.c 4.3 82/11/14 */ #include <sys/types.h> #include <netinet/in.h> /* * Return the network number from an internet * address; handles class a/b/c network #'s. */ inet_netof(in) struct in_addr in; { register u_long i = ntohl(in.s_addr); if (IN_CLASSA(i)) return (((i)&IN_CLASSA_NET) >> IN_CLASSA_NSHIFT); else if (IN_CLASSB(i)) return (((i)&IN_CLASSB_NET) >> IN_CLASSB_NSHIFT); else return (((i)&IN_CLASSC_NET) >> IN_CLASSC_NSHIFT); }