freebsd-src/contrib/ntp/libntp/netof.c
1999-12-09 13:01:21 +00:00

26 lines
439 B
C

/*
* netof - return the net address part of an ip address
* (zero out host part)
*/
#include <stdio.h>
#include "ntp_fp.h"
#include "ntp_stdlib.h"
u_int32
netof(
u_int32 num
)
{
register u_int32 netnum;
netnum = num;
if(IN_CLASSC(netnum))
netnum &= IN_CLASSC_NET;
else if (IN_CLASSB(netnum))
netnum &= IN_CLASSB_NET;
else /* treat all other like class A */
netnum &= IN_CLASSA_NET;
return netnum;
}