xref: /freebsd/contrib/openpam/lib/libpam/openpam_load.c (revision bdd1243df58e60e85101c09001d9812a789b6bc4)
1 /*-
2  * Copyright (c) 2002-2003 Networks Associates Technology, Inc.
3  * Copyright (c) 2004-2013 Dag-Erling Smørgrav
4  * All rights reserved.
5  *
6  * This software was developed for the FreeBSD Project by ThinkSec AS and
7  * Network Associates Laboratories, the Security Research Division of
8  * Network Associates, Inc.  under DARPA/SPAWAR contract N66001-01-C-8035
9  * ("CBOSS"), as part of the DARPA CHATS research program.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. The name of the author may not be used to endorse or promote
20  *    products derived from this software without specific prior written
21  *    permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  *
35  * $OpenPAM: openpam_load.c 938 2017-04-30 21:34:42Z des $
36  */
37 
38 #ifdef HAVE_CONFIG_H
39 # include "config.h"
40 #endif
41 
42 #include <dlfcn.h>
43 #include <stdlib.h>
44 #include <string.h>
45 
46 #include <security/pam_appl.h>
47 
48 #include "openpam_impl.h"
49 
50 /*
51  * Locate a matching dynamic or static module.
52  */
53 
54 pam_module_t *
55 openpam_load_module(const char *modulename)
56 {
57 	pam_module_t *module;
58 
59 	module = openpam_dynamic(modulename);
60 	openpam_log(PAM_LOG_DEBUG, "%s dynamic %s",
61 	    (module == NULL) ? "no" : "using", modulename);
62 
63 #ifdef OPENPAM_STATIC_MODULES
64 	/* look for a static module */
65 	if (module == NULL && strchr(modulename, '/') == NULL) {
66 		module = openpam_static(modulename);
67 		openpam_log(PAM_LOG_DEBUG, "%s static %s",
68 		    (module == NULL) ? "no" : "using", modulename);
69 	}
70 #endif
71 	if (module == NULL) {
72 		openpam_log(PAM_LOG_ERROR, "no %s found", modulename);
73 		return (NULL);
74 	}
75 	return (module);
76 }
77 
78 
79 /*
80  * Release a module.
81  * XXX highly thread-unsafe
82  */
83 
84 static void
85 openpam_release_module(pam_module_t *module)
86 {
87 
88 	if (module == NULL)
89 		return;
90 	if (module->dlh == NULL)
91 		/* static module */
92 		return;
93 	dlclose(module->dlh);
94 	openpam_log(PAM_LOG_DEBUG, "releasing %s", module->path);
95 	FREE(module->path);
96 	FREE(module);
97 }
98 
99 
100 /*
101  * Destroy a chain, freeing all its links and releasing the modules
102  * they point to.
103  */
104 
105 static void
106 openpam_destroy_chain(pam_chain_t *chain)
107 {
108 
109 	if (chain == NULL)
110 		return;
111 	openpam_destroy_chain(chain->next);
112 	chain->next = NULL;
113 	FREEV(chain->optc, chain->optv);
114 	openpam_release_module(chain->module);
115 	chain->module = NULL;
116 	FREE(chain);
117 }
118 
119 
120 /*
121  * Clear the chains and release the modules
122  */
123 
124 void
125 openpam_clear_chains(pam_chain_t *policy[])
126 {
127 	int i;
128 
129 	for (i = 0; i < PAM_NUM_FACILITIES; ++i) {
130 		openpam_destroy_chain(policy[i]);
131 		policy[i] = NULL;
132 	}
133 }
134 
135 /*
136  * NOPARSE
137  */
138