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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (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 2008 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/*
* 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 "lint.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;
#ifndef NSS_DLOPEN_FORMAT
#define NSS_DLOPEN_FORMAT "nss_%s.so.%d"
#endif
#ifndef NSS_DLSYM_FORMAT
#define NSS_DLSYM_FORMAT "_nss_%s_%s_constr"
#endif
static const char dlopen_format[] = NSS_DLOPEN_FORMAT;
static const char dlsym_format [] = NSS_DLSYM_FORMAT;
static const size_t format_maxlen = sizeof (dlsym_format) - 4;
static nss_backend_constr_t
SO_per_src_lookup(void *dummy __unused, 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);
}
static void
SO_per_src_delete(void *delete_priv, nss_backend_constr_t dummy __unused)
{
(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;
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