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Annotation of embedaddon/ntp/libntp/netof.c, revision 1.1.1.1

1.1       misho       1: /* 
                      2:  * netof - return the net address part of an ip address in a sockaddr_storage structure
                      3:  *         (zero out host part)
                      4:  */
                      5: #include <stdio.h>
                      6: #include <syslog.h>
                      7: 
                      8: #include "ntp_fp.h"
                      9: #include "ntp_net.h"
                     10: #include "ntp_stdlib.h"
                     11: #include "ntp.h"
                     12: 
                     13: sockaddr_u *
                     14: netof(
                     15:        sockaddr_u *hostaddr
                     16:        )
                     17: {
                     18:        static sockaddr_u       netofbuf[8];
                     19:        static int              next_netofbuf;
                     20:        u_int32                 netnum;
                     21:        sockaddr_u *            netaddr;
                     22: 
                     23:        netaddr = &netofbuf[next_netofbuf];
                     24:        next_netofbuf = (next_netofbuf + 1) % COUNTOF(netofbuf);
                     25: 
                     26:        memcpy(netaddr, hostaddr, sizeof(*netaddr));
                     27: 
                     28:        if (IS_IPV4(netaddr)) {
                     29:                netnum = SRCADR(netaddr);
                     30: 
                     31:                /*
                     32:                 * We live in a modern CIDR world where the basement nets, which
                     33:                 * used to be class A, are now probably associated with each
                     34:                 * host address. So, for class-A nets, all bits are significant.
                     35:                 */
                     36:                if (IN_CLASSC(netnum))
                     37:                        netnum &= IN_CLASSC_NET;
                     38:                else if (IN_CLASSB(netnum))
                     39:                        netnum &= IN_CLASSB_NET;
                     40: 
                     41:                SET_ADDR4(netaddr, netnum);
                     42: 
                     43:        } else if (IS_IPV6(netaddr))
                     44:                /* assume the typical /64 subnet size */
                     45:                memset(&NSRCADR6(netaddr)[8], 0, 8);
                     46: #ifdef DEBUG
                     47:        else {
                     48:                msyslog(LOG_ERR, "netof unknown AF %d", AF(netaddr));
                     49:                exit(1);
                     50:        }
                     51: #endif
                     52: 
                     53:        return netaddr;
                     54: }