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/*-
* Copyright (c) 1999 Brian Somers <brian@Awfulhak.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $Id: realhostname.c,v 1.1 1999/04/06 23:02:35 brian Exp $
*/
#include <sys/param.h>
#include <sys/socket.h>
#include <netdb.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdio.h>
#include <string.h>
#include "libutil.h"
int
realhostname(char *host, size_t hsize, const struct in_addr *ip)
{
int result;
struct hostent *hp;
result = HOSTNAME_INVALIDADDR;
hp = gethostbyaddr((char *)ip, sizeof(*ip), AF_INET);
if (hp != NULL && strlen(hp->h_name) <= hsize) {
char lookup[MAXHOSTNAMELEN];
strncpy(lookup, hp->h_name, sizeof(lookup) - 1);
lookup[sizeof(lookup) - 1] = '\0';
hp = gethostbyname(lookup);
if (hp == NULL)
result = HOSTNAME_INVALIDNAME;
else for (; ; hp->h_addr_list++) {
if (hp->h_addr_list[0] == NULL) {
result = HOSTNAME_INCORRECTNAME;
break;
}
if (!memcmp(*hp->h_addr_list, ip, sizeof(*ip))) {
strncpy(host, lookup, hsize);
return HOSTNAME_FOUND;
}
}
}
strncpy(host, inet_ntoa(*ip), hsize);
return result;
}
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