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

1.1       misho       1: /*
                      2:  * numtohost - convert network number to host name.
                      3:  */
                      4: #include <config.h>
                      5: 
                      6: #include <sys/types.h>
                      7: #ifdef HAVE_NETINET_IN_H
                      8: #include <netinet/in.h>                /* ntohl */
                      9: #endif
                     10: 
                     11: #include "ntp_fp.h"
                     12: #include "ntp_stdlib.h"
                     13: #include "lib_strbuf.h"
                     14: 
                     15: #define        LOOPBACKNET     0x7f000000
                     16: #define        LOOPBACKHOST    0x7f000001
                     17: #define        LOOPBACKNETMASK 0xff000000
                     18: 
                     19: char *
                     20: numtohost(
                     21:        u_int32 netnum
                     22:        )
                     23: {
                     24:        char *bp;
                     25:        struct hostent *hp;
                     26: 
                     27:        /*
                     28:         * This is really gross, but saves lots of hanging looking for
                     29:         * hostnames for the radio clocks.  Don't bother looking up
                     30:         * addresses on the loopback network except for the loopback
                     31:         * host itself.
                     32:         */
                     33:        if ((((ntohl(netnum) & LOOPBACKNETMASK) == LOOPBACKNET)
                     34:             && (ntohl(netnum) != LOOPBACKHOST))
                     35:            || ((hp = gethostbyaddr((char *)&netnum, sizeof netnum, AF_INET))
                     36:                == 0))
                     37:            return numtoa(netnum);
                     38:        
                     39:        LIB_GETBUF(bp);
                     40:        
                     41:        bp[LIB_BUFLENGTH-1] = '\0';
                     42:        (void) strncpy(bp, hp->h_name, LIB_BUFLENGTH-1);
                     43:        return bp;
                     44: }