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/*
dnsconfig.c - lookup code for DNS SRV records
This file was part of the nss_ldap library which has been
forked into the nss-ldapd library.
Copyright (C) 1997-2005 Luke Howard
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA
*/
/*
* Support DNS SRV records. I look up the SRV record for
* _ldap._tcp.gnu.org.
* and build the DN DC=gnu,DC=org.
* Thanks to Assar & co for resolve.[ch].
*/
#include "config.h"
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/param.h>
#include <netdb.h>
#include <netinet/in.h>
#include <arpa/nameser.h>
#include <resolv.h>
#include <string.h>
#ifdef HAVE_LBER_H
#include <lber.h>
#endif
#ifdef HAVE_LDAP_H
#include <ldap.h>
#endif
#include "ldap-nss.h"
#include "util.h"
#include "resolve.h"
#include "dnsconfig.h"
#define DC_ATTR "DC"
#define DC_ATTR_AVA DC_ATTR"="
#define DC_ATTR_AVA_LEN (sizeof(DC_ATTR_AVA) - 1)
/* map gnu.org into DC=gnu,DC=org */
static enum nss_status
_nss_ldap_getdnsdn (char *src_domain,
char **rval, char **buffer, size_t * buflen)
{
char *p;
int len = 0;
#ifdef HAVE_STRTOK_R
char *st = NULL;
#endif
char *bptr;
char *domain, *domain_copy;
/* we need to take a copy of domain, because strtok() modifies
* it in place. Bad.
*/
domain_copy = strdup (src_domain);
if (domain_copy == NULL)
{
return NSS_STATUS_TRYAGAIN;
}
domain = domain_copy;
bptr = *rval = *buffer;
**rval = '\0';
#ifndef HAVE_STRTOK_R
while ((p = strtok (domain, ".")))
#else
while ((p = strtok_r (domain, ".", &st)))
#endif
{
len = strlen (p);
if (*buflen < (size_t) (len + DC_ATTR_AVA_LEN + 1 /* D C = [,|\0] */ ))
{
free (domain_copy);
return NSS_STATUS_TRYAGAIN;
}
if (domain == NULL)
{
strcpy (bptr, ",");
bptr++;
}
else
{
domain = NULL;
}
strcpy (bptr, DC_ATTR_AVA);
bptr += DC_ATTR_AVA_LEN;
strcpy (bptr, p);
bptr += len; /* don't include comma */
*buffer += len + DC_ATTR_AVA_LEN + 1;
*buflen -= len + DC_ATTR_AVA_LEN + 1;
}
if (bptr != NULL)
{
(*rval)[bptr - *rval] = '\0';
}
free (domain_copy);
return NSS_STATUS_SUCCESS;
}
enum nss_status
_nss_ldap_mergeconfigfromdns (struct ldap_config * result,
char **buffer, size_t *buflen)
{
enum nss_status stat = NSS_STATUS_SUCCESS;
struct dns_reply *r;
struct resource_record *rr;
char domain[MAXHOSTNAMELEN + 1];
char *pDomain;
char uribuf[1024];
if ((_res.options & RES_INIT) == 0 && res_init () == -1)
{
return NSS_STATUS_UNAVAIL;
}
if (result->ldc_srv_domain != NULL)
pDomain = result->ldc_srv_domain;
else
{
snprintf (domain, sizeof (domain), "_ldap._tcp.%s.", _res.defdname);
pDomain = domain;
}
r = dns_lookup (pDomain, "srv");
if (r == NULL)
{
return NSS_STATUS_NOTFOUND;
}
/* XXX sort by priority */
for (rr = r->head; rr != NULL; rr = rr->next)
{
if (rr->type == T_SRV)
{
snprintf (uribuf, sizeof(uribuf), "ldap%s:%s:%d",
(rr->u.srv->port == LDAPS_PORT) ? "s" : "",
rr->u.srv->target,
rr->u.srv->port);
stat = _nss_ldap_add_uri (result, uribuf, buffer, buflen);
if (stat != NSS_STATUS_SUCCESS)
{
break;
}
}
}
dns_free_data (r);
stat = NSS_STATUS_SUCCESS;
if (result->ldc_base == NULL)
{
stat = _nss_ldap_getdnsdn (_res.defdname, &result->ldc_base,
buffer, buflen);
}
return stat;
}
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