1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 /* 23 * Copyright 2004 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #pragma ident "%Z%%M% %I% %E% SMI" 28 29 /* 30 * Default backend-finder(s) for the name-service-switch routines. 31 * At present there is a single finder that uses dlopen() to do its thing. 32 * 33 * === Could also do a finder that includes db-name in filename 34 * === and one that does dlopen(0) to check in the executable 35 */ 36 37 /* Allow our finder(s) to be overridden by user-supplied ones */ 38 39 #pragma weak nss_default_finders = _nss_default_finders 40 41 #include "synonyms.h" 42 #include "mtlib.h" 43 #include <nss_common.h> 44 #include <dlfcn.h> 45 #include <stdio.h> 46 #include <stdlib.h> 47 #include <string.h> 48 #include <alloca.h> 49 50 /* === ? move these constants to a public header file ? */ 51 static const int dlopen_version = 1; 52 static const char dlopen_format[] = "nss_%s.so.%d"; 53 static const char dlsym_format [] = "_nss_%s_%s_constr"; 54 static const size_t format_maxlen = sizeof (dlsym_format) - 4; 55 56 /*ARGSUSED*/ 57 static nss_backend_constr_t 58 SO_per_src_lookup(void *dummy, const char *db_name, const char *src_name, 59 void **delete_privp) 60 { 61 char *name; 62 void *dlhandle; 63 void *sym; 64 size_t len; 65 nss_backend_constr_t res = 0; 66 67 len = format_maxlen + strlen(db_name) + strlen(src_name); 68 name = alloca(len); 69 (void) sprintf(name, dlopen_format, src_name, dlopen_version); 70 if ((dlhandle = dlopen(name, RTLD_LAZY)) != 0) { 71 (void) sprintf(name, dlsym_format, src_name, db_name); 72 if ((sym = dlsym(dlhandle, name)) == 0) { 73 (void) dlclose(dlhandle); 74 } else { 75 *delete_privp = dlhandle; 76 res = (nss_backend_constr_t)sym; 77 } 78 } 79 return (res); 80 } 81 82 /*ARGSUSED*/ 83 static void 84 SO_per_src_delete(void *delete_priv, nss_backend_constr_t dummy) 85 { 86 (void) dlclose(delete_priv); 87 } 88 89 static nss_backend_finder_t SO_per_src = { 90 SO_per_src_lookup, 91 SO_per_src_delete, 92 0, 93 0 94 }; 95 96 nss_backend_finder_t *_nss_default_finders = &SO_per_src; 97