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 (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright 2006 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 26 #pragma ident "%Z%%M% %I% %E% SMI" 27 28 /* 29 * Default backend-finder(s) for the name-service-switch routines. 30 * At present there is a single finder that uses dlopen() to do its thing. 31 * 32 * === Could also do a finder that includes db-name in filename 33 * === and one that does dlopen(0) to check in the executable 34 */ 35 36 /* Allow our finder(s) to be overridden by user-supplied ones */ 37 38 #pragma weak nss_default_finders = _nss_default_finders 39 40 #include "synonyms.h" 41 #include "mtlib.h" 42 #include <nss_common.h> 43 #include <dlfcn.h> 44 #include <stdio.h> 45 #include <stdlib.h> 46 #include <string.h> 47 #include <alloca.h> 48 49 /* === ? move these constants to a public header file ? */ 50 static const int dlopen_version = 1; 51 #ifndef NSS_DLOPEN_FORMAT 52 #define NSS_DLOPEN_FORMAT "nss_%s.so.%d" 53 #endif 54 #ifndef NSS_DLSYM_FORMAT 55 #define NSS_DLSYM_FORMAT "_nss_%s_%s_constr" 56 #endif 57 static const char dlopen_format[] = NSS_DLOPEN_FORMAT; 58 static const char dlsym_format [] = NSS_DLSYM_FORMAT; 59 static const size_t format_maxlen = sizeof (dlsym_format) - 4; 60 61 /*ARGSUSED*/ 62 static nss_backend_constr_t 63 SO_per_src_lookup(void *dummy, const char *db_name, const char *src_name, 64 void **delete_privp) 65 { 66 char *name; 67 void *dlhandle; 68 void *sym; 69 size_t len; 70 nss_backend_constr_t res = 0; 71 72 len = format_maxlen + strlen(db_name) + strlen(src_name); 73 name = alloca(len); 74 (void) sprintf(name, dlopen_format, src_name, dlopen_version); 75 if ((dlhandle = dlopen(name, RTLD_LAZY)) != 0) { 76 (void) sprintf(name, dlsym_format, src_name, db_name); 77 if ((sym = dlsym(dlhandle, name)) == 0) { 78 (void) dlclose(dlhandle); 79 } else { 80 *delete_privp = dlhandle; 81 res = (nss_backend_constr_t)sym; 82 } 83 } 84 return (res); 85 } 86 87 /*ARGSUSED*/ 88 static void 89 SO_per_src_delete(void *delete_priv, nss_backend_constr_t dummy) 90 { 91 (void) dlclose(delete_priv); 92 } 93 94 static nss_backend_finder_t SO_per_src = { 95 SO_per_src_lookup, 96 SO_per_src_delete, 97 0, 98 0 99 }; 100 101 nss_backend_finder_t *_nss_default_finders = &SO_per_src; 102