42 lines
922 B
C
42 lines
922 B
C
/* $NetBSD: numtohost.c,v 1.2 2003/12/04 16:23:37 drochner Exp $ */
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/*
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* numtohost - convert network number to host name.
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*/
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#include <netdb.h>
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#include "ntp_fp.h"
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#include "ntp_stdlib.h"
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#include "lib_strbuf.h"
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#define LOOPBACKNET 0x7f000000
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#define LOOPBACKHOST 0x7f000001
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#define LOOPBACKNETMASK 0xff000000
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char *
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numtohost(
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u_int32 netnum
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)
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{
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char *bp;
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struct hostent *hp;
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/*
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* This is really gross, but saves lots of hanging looking for
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* hostnames for the radio clocks. Don't bother looking up
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* addresses on the loopback network except for the loopback
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* host itself.
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*/
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if ((((ntohl(netnum) & LOOPBACKNETMASK) == LOOPBACKNET)
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&& (ntohl(netnum) != LOOPBACKHOST))
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|| ((hp = gethostbyaddr((char *)&netnum, sizeof netnum, AF_INET))
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== 0))
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return numtoa(netnum);
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LIB_GETBUF(bp);
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bp[LIB_BUFLENGTH-1] = '\0';
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(void) strncpy(bp, hp->h_name, LIB_BUFLENGTH-1);
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return bp;
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}
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