usr/src/lib/libc/net/inet_netof.c

/*      inet_netof.c    4.1     82/10/07        */

#include <sys/types.h>
#include <net/in.h>

/*
 * Return the network number from an internet
 * address; handles class a/b/c network #'s.
 */
in_netof(in)
        struct in_addr in;
{
#if vax || pdp11
        register u_long net;

        if ((in.s_addr&IN_CLASSA) == 0)
                return (in.s_addr & IN_CLASSA_NET);
        if ((in.s_addr&IN_CLASSB) == 0)
                return ((int)htons((u_short)(in.s_addr & IN_CLASSB_NET)));
        net = htonl((u_long)(in.s_addr & IN_CLASSC_NET));
        net >>= 8;
        return ((int)net);
#else
        return (IN_NETOF(in));
#endif
}