/*

 * CDDL HEADER START

 *

 * The contents of this file are subject to the terms of the

 * Common Development and Distribution License, Version 1.0 only

 * (the "License").  You may not use this file except in compliance

 * with the License.

 *

 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE

 * or http://www.opensolaris.org/os/licensing.

 * See the License for the specific language governing permissions

 * and limitations under the License.

 *

 * When distributing Covered Code, include this CDDL HEADER in each

 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.

 * If applicable, add the following below this CDDL HEADER, with the

 * fields enclosed by brackets "[]" replaced with your own identifying

 * information: Portions Copyright [yyyy] [name of copyright owner]

 *

 * CDDL HEADER END

 */

/*

 * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.

 * Use is subject to license terms.

 */

#pragma ident	"%Z%%M%	%I%	%E% SMI"

/*

 * Default backend-finder(s) for the name-service-switch routines.

 * At present there is a single finder that uses dlopen() to do its thing.

 *

 * === Could also do a finder that includes db-name in filename

 * === and one that does dlopen(0) to check in the executable

 */

	/* Allow our finder(s) to be overridden by user-supplied ones */

#pragma weak nss_default_finders = _nss_default_finders

#include "synonyms.h"

#include "mtlib.h"

#include <nss_common.h>

#include <dlfcn.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <alloca.h>

/* === ? move these constants to a public header file ? */

static const int  dlopen_version  = 1;

static const char dlopen_format[] = "nss_%s.so.%d";

static const char dlsym_format [] = "_nss_%s_%s_constr";

static const size_t  format_maxlen   = sizeof (dlsym_format) - 4;

/*ARGSUSED*/

static nss_backend_constr_t

SO_per_src_lookup(void *dummy, const char *db_name, const char *src_name,

	void **delete_privp)

{

	char			*name;

	void			*dlhandle;

	void			*sym;

	size_t			len;

	nss_backend_constr_t	res = 0;

	len = format_maxlen + strlen(db_name) + strlen(src_name);

	name = alloca(len);

	(void) sprintf(name, dlopen_format, src_name, dlopen_version);

	if ((dlhandle = dlopen(name, RTLD_LAZY)) != 0) {

		(void) sprintf(name, dlsym_format, src_name, db_name);

		if ((sym = dlsym(dlhandle, name)) == 0) {

			(void) dlclose(dlhandle);

		} else {

			*delete_privp = dlhandle;

			res = (nss_backend_constr_t)sym;

		}

	}

	return (res);

}

/*ARGSUSED*/

static void

SO_per_src_delete(void *delete_priv, nss_backend_constr_t dummy)

{

	(void) dlclose(delete_priv);

}

static nss_backend_finder_t SO_per_src = {

	SO_per_src_lookup,

	SO_per_src_delete,

	0,

	0

};

nss_backend_finder_t *_nss_default_finders = &SO_per_src;