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/*
* pty_make_sane_hostname: Make a sane hostname from an IP address.
* This returns allocated memory!
*
* Copyright 1999 by the Massachusetts Institute of Technology.
*
* Permission to use, copy, modify, and distribute this software and
* its documentation for any purpose and without fee is hereby
* granted, provided that the above copyright notice appear in all
* copies and that both that copyright notice and this permission
* notice appear in supporting documentation, and that the name of
* M.I.T. not be used in advertising or publicity pertaining to
* distribution of the software without specific, written prior
* permission. M.I.T. makes no representations about the suitability
* of this software for any purpose. It is provided "as is" without
* express or implied warranty.
*
*/
#include <com_err.h>
#include "pty-int.h"
#include "libpty.h"
#include <arpa/inet.h>
static long
do_ntoa(struct sockaddr_in *addr,
size_t hostlen,
char **out)
{
strncpy(*out, inet_ntoa(addr->sin_addr), hostlen);
(*out)[hostlen - 1] = '\0';
return 0;
}
long
pty_make_sane_hostname(struct sockaddr_in *addr,
int maxlen,
int strip_ldomain,
int always_ipaddr,
char **out)
{
struct hostent *hp;
#ifndef NO_UT_HOST
struct utmp ut;
#else
struct utmpx utx;
#endif
char *cp, *domain;
char lhost[MAXHOSTNAMELEN];
size_t ut_host_len;
*out = NULL;
if (maxlen && maxlen < 16)
/* assume they meant 16, otherwise IP addr won't fit */
maxlen = 16;
#ifndef NO_UT_HOST
ut_host_len = sizeof (ut.ut_host);
#else
ut_host_len = sizeof (utx.ut_host);
#endif
if (maxlen == 0)
maxlen = ut_host_len;
*out = malloc(ut_host_len);
if (*out == NULL)
return ENOMEM;
if (always_ipaddr) {
return do_ntoa(addr, ut_host_len, out);
}
hp = gethostbyaddr((char *)&addr->sin_addr, sizeof (struct in_addr),
addr->sin_family);
if (hp == NULL) {
return do_ntoa(addr, ut_host_len, out);
}
strncpy(*out, hp->h_name, ut_host_len);
(*out)[ut_host_len - 1] = '\0';
for (cp = *out; *cp != '\0'; cp++)
*cp = tolower(*cp);
if (strip_ldomain) {
(void) gethostname(lhost, sizeof (lhost));
hp = gethostbyname(lhost);
if (hp != NULL) {
strncpy(lhost, hp->h_name, sizeof (lhost));
domain = strchr(lhost, '.');
if (domain != NULL) {
for (cp = domain; *cp != '\0'; cp++)
*cp = tolower(*cp);
cp = strstr(*out, domain);
if (cp != NULL)
*cp = '\0';
}
}
}
if (strlen(*out) >= maxlen) {
return do_ntoa(addr, ut_host_len, out);
}
return 0;
}
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