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/* -*- Mode: C; indent-tabs-mode: t; c-basic-offset: 8; tab-width: 8 -*- */
/* e-host-utils.c
*
* Copyright (C) 2001 Helix Code, Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*
* Author: Chris Toshok
*/
#include <config.h>
#include <glib.h>
#include "e-host-utils.h"
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
G_LOCK_DEFINE_STATIC (gethost_mutex);
/**
* e_gethostbyname_r:
* @name: the host to resolve
* @host: a buffer pointing to a struct hostent to use for storage
* @buf: a buffer to use for hostname storage
* @buflen: the size of @buf
* @herr: a pointer to a variable to store an error code in
*
* Resolves the hostname @name, in a hopefully-reentrant fashion.
*
* Return value: 0 on success, ERANGE if @buflen is too small,
* "something else" otherwise (in which case *@herr will be set to
* one of the gethostbyname() error codes).
**/
int
e_gethostbyname_r (const char *name, struct hostent *host,
char *buf, int buflen, int *herr)
{
#ifdef HAVE_GETHOSTBYNAME_R
#ifdef GETHOSTBYNAME_R_FIVE_ARGS
if (gethostbyname_r(name, host, buf, buflen, herr))
return 0;
else
return errno;
#else
struct hostent *hp;
return gethostbyname_r(name, host, buf, buflen, &hp, herr);
#endif
#else
int i;
char *p;
struct hostent *h;
int req_length;
int num_aliases = 0, num_addrs = 0;
G_LOCK (gethost_mutex);
h = gethostbyname (name);
if (!h) {
*herr = h_errno;
G_UNLOCK (gethost_mutex);
return -1;
}
/* check to make sure we have enough room in our buffer */
req_length = 0;
if (h->h_aliases) {
for (i = 0; h->h_aliases[i]; i ++)
req_length += strlen (h->h_aliases[i]) + 1;
num_aliases = i;
}
if (h->h_addr_list) {
for (i = 0; h->h_addr_list[i]; i ++)
req_length += h->h_length;
num_addrs = i;
}
req_length += sizeof (char*) * (num_aliases + 1);
req_length += sizeof (char*) * (num_addrs + 1);
req_length += strlen (h->h_name) + 1;
if (buflen < req_length) {
*herr = ERANGE;
G_UNLOCK (gethost_mutex);
return ERANGE;
}
/* we store the alias/addr pointers in the buffer - figure out
their addresses here. */
p = buf;
if (num_aliases) {
host->h_aliases = (char**)p;
p += sizeof (char*) * (num_aliases + 1);
}
else
host->h_aliases = NULL;
if (num_addrs) {
host->h_addr_list = (char**)p;
p += sizeof(char*) * (num_addrs + 1);
}
else
host->h_addr_list = NULL;
/* copy the host name into the buffer */
host->h_name = p;
strcpy (p, h->h_name);
p += strlen (h->h_name) + 1;
host->h_addrtype = h->h_addrtype;
host->h_length = h->h_length;
/* copy the aliases/addresses into the buffer, and assign the
pointers into the hostent */
*p = 0;
if (num_aliases) {
for (i = 0; i < num_aliases; i ++) {
strcpy (p, h->h_aliases[i]);
host->h_aliases[i] = p;
p += strlen (h->h_aliases[i]);
}
host->h_aliases[num_aliases] = NULL;
}
if (num_addrs) {
for (i = 0; i < num_addrs; i ++) {
memcpy (p, h->h_addr_list[i], h->h_length);
host->h_addr_list[i] = p;
p += h->h_length;
}
host->h_addr_list[num_addrs] = NULL;
}
G_UNLOCK (gethost_mutex);
return 0;
#endif
}
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