xref: /netbsd-src/external/bsd/openpam/dist/lib/libpam/openpam_load.c (revision 0d9d0fd8a30be9a1924e715bbcf67a4a83efd262)
1 /*	$NetBSD: openpam_load.c,v 1.4 2023/06/30 21:46:20 christos Exp $	*/
2 
3 /*-
4  * Copyright (c) 2002-2003 Networks Associates Technology, Inc.
5  * Copyright (c) 2004-2013 Dag-Erling Smørgrav
6  * All rights reserved.
7  *
8  * This software was developed for the FreeBSD Project by ThinkSec AS and
9  * Network Associates Laboratories, the Security Research Division of
10  * Network Associates, Inc.  under DARPA/SPAWAR contract N66001-01-C-8035
11  * ("CBOSS"), as part of the DARPA CHATS research program.
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  * 3. The name of the author may not be used to endorse or promote
22  *    products derived from this software without specific prior written
23  *    permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35  * SUCH DAMAGE.
36  */
37 
38 #ifdef HAVE_CONFIG_H
39 # include "config.h"
40 #endif
41 
42 #include <sys/cdefs.h>
43 __RCSID("$NetBSD: openpam_load.c,v 1.4 2023/06/30 21:46:20 christos Exp $");
44 
45 #include <dlfcn.h>
46 #include <stdlib.h>
47 #include <string.h>
48 
49 #include <security/pam_appl.h>
50 
51 #include "openpam_impl.h"
52 
53 /*
54  * Locate a matching dynamic or static module.
55  */
56 
57 pam_module_t *
openpam_load_module(const char * modulename)58 openpam_load_module(const char *modulename)
59 {
60 	pam_module_t *module;
61 
62 	module = openpam_dynamic(modulename);
63 	openpam_log(PAM_LOG_DEBUG, "%s dynamic %s",
64 	    (module == NULL) ? "no" : "using", modulename);
65 
66 #ifdef OPENPAM_STATIC_MODULES
67 	/* look for a static module */
68 	if (module == NULL && strchr(modulename, '/') == NULL) {
69 		module = openpam_static(modulename);
70 		openpam_log(PAM_LOG_DEBUG, "%s static %s",
71 		    (module == NULL) ? "no" : "using", modulename);
72 	}
73 #endif
74 	if (module == NULL) {
75 		openpam_log(PAM_LOG_ERROR, "no %s found", modulename);
76 		return (NULL);
77 	}
78 	return (module);
79 }
80 
81 
82 /*
83  * Release a module.
84  * XXX highly thread-unsafe
85  */
86 
87 static void
openpam_release_module(pam_module_t * module)88 openpam_release_module(pam_module_t *module)
89 {
90 
91 	if (module == NULL)
92 		return;
93 	if (module->dlh == NULL)
94 		/* static module */
95 		return;
96 	dlclose(module->dlh);
97 	openpam_log(PAM_LOG_DEBUG, "releasing %s", module->path);
98 	FREE(module->path);
99 	FREE(module);
100 }
101 
102 
103 /*
104  * Destroy a chain, freeing all its links and releasing the modules
105  * they point to.
106  */
107 
108 static void
openpam_destroy_chain(pam_chain_t * chain)109 openpam_destroy_chain(pam_chain_t *chain)
110 {
111 
112 	if (chain == NULL)
113 		return;
114 	openpam_destroy_chain(chain->next);
115 	chain->next = NULL;
116 	FREEV(chain->optc, chain->optv);
117 	openpam_release_module(chain->module);
118 	chain->module = NULL;
119 	FREE(chain);
120 }
121 
122 
123 /*
124  * Clear the chains and release the modules
125  */
126 
127 void
openpam_clear_chains(pam_chain_t * policy[])128 openpam_clear_chains(pam_chain_t *policy[])
129 {
130 	int i;
131 
132 	for (i = 0; i < PAM_NUM_FACILITIES; ++i) {
133 		openpam_destroy_chain(policy[i]);
134 		policy[i] = NULL;
135 	}
136 }
137 
138 /*
139  * NOPARSE
140  */
141