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/*
* Copyright (c) 1992, 1993, 1994, 1995, 1996, 1998, 2000
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that: (1) source code distributions
* retain the above copyright notice and this paragraph in its entirety, (2)
* distributions including binary code include the above copyright notice and
* this paragraph in its entirety in the documentation or other materials
* provided with the distribution, and (3) all advertising materials mentioning
* features or use of this software display the following acknowledgement:
* ``This product includes software developed by the University of California,
* Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
* the University nor the names of its contributors may be used to endorse
* or promote products derived from this software without specific prior
* written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
#ifndef lint
static const char rcsid[] =
"@(#) $Id: dns.c,v 1.15 2000/09/30 23:40:40 leres Exp $ (LBL)";
#endif
/*
* dns - domain name system routines
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/nameser.h>
#include <arpa/inet.h>
#include <ctype.h>
#ifdef HAVE_MEMORY_H
#include <memory.h>
#endif
#include <netdb.h>
#include <resolv.h>
#include <string.h>
#include <stdio.h>
#include "gnuc.h"
#ifdef HAVE_OS_PROTO_H
#include "os-proto.h"
#endif
#include "arpwatch.h"
#include "dns.h"
#ifdef HAVE_DN_SKIPNAME
#ifndef BUFSIZ
#define BUFSIZ 1024
#endif
static char hostbuf[BUFSIZ+1];
#if PACKETSZ > 1024
#define MAXPACKET PACKETSZ
#else
#define MAXPACKET 1024
#endif
typedef union {
HEADER hdr;
u_char buf[MAXPACKET];
} querybuf;
#endif
int
gethinfo(register char *hostname, register char *cpu, register int cpulen,
register char *os, register int oslen)
{
#ifdef HAVE_DN_SKIPNAME
register querybuf *qb;
register u_char *cp, *eom;
register char *bp;
register int n;
register HEADER *hp;
register int type, class, buflen, ancount, qdcount;
querybuf qbuf;
qb = &qbuf;
n = res_query(hostname, C_IN, T_HINFO, qb->buf, sizeof(qb->buf));
if (n < 0)
return (0);
eom = qb->buf + n;
/*
* find first satisfactory answer
*/
hp = &qb->hdr;
ancount = ntohs(hp->ancount);
qdcount = ntohs(hp->qdcount);
bp = hostbuf;
buflen = sizeof(hostbuf);
cp = qb->buf + sizeof(HEADER);
if (qdcount) {
cp += dn_skipname(cp, eom) + QFIXEDSZ;
while (--qdcount > 0)
cp += dn_skipname(cp, eom) + QFIXEDSZ;
}
while (--ancount >= 0 && cp < eom) {
if ((n = dn_expand((u_char *)qb->buf, (u_char *)eom,
(u_char *)cp, (u_char *)bp, buflen)) < 0)
break;
cp += n;
type = ns_get16(cp);
cp += sizeof(u_short);
class = ns_get16(cp);
cp += sizeof(u_short) + sizeof(u_int32_t);
n = ns_get16(cp);
cp += sizeof(u_short);
if (type == T_HINFO) {
/* Unpack */
n = *cp++;
if (n > cpulen - 1)
return (0);
BCOPY(cp, cpu, n);
cp += n;
cpu[n] = '\0';
n = *cp++;
if (n > oslen - 1)
return (0);
BCOPY(cp, os, n);
os[n] = '\0';
return (1);
}
/* Skip unexpected junk */
cp += n;
}
#endif
return (0);
}
/* Return the cannonical name of the host */
char *
gethname(u_int32_t a)
{
register int32_t options;
register struct hostent *hp;
options = _res.options;
_res.options |= RES_AAONLY;
_res.options &= ~(RES_DEFNAMES | RES_DNSRCH);
hp = gethostbyaddr((char *)&a, sizeof(a), AF_INET);
_res.options = options;
if (hp == NULL)
return (intoa(a));
return (hp->h_name);
}
/* Return the simple name of the host */
char *
getsname(register u_int32_t a)
{
register char *s, *cp;
s = gethname(a);
if (!isdigit((int)*s)) {
cp = strchr(s, '.');
if (cp != NULL)
*cp = '\0';
}
return (s);
}
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