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DEFINITIONS
This source file includes following definitions.
- _krb5_plugin_get_symbol
- _krb5_plugin_get_next
- loadlib
- krb5_plugin_register
- _krb5_plugin_find
- _krb5_plugin_free
1 /*
2 * Copyright (c) 2006 - 2007 Kungliga Tekniska Högskolan
3 * (Royal Institute of Technology, Stockholm, Sweden).
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * 3. Neither the name of the Institute nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34 #include "krb5_locl.h"
35 RCSID("$Id$");
36 #ifdef HAVE_DLFCN_H
37 #include <dlfcn.h>
38 #endif
39 #include <dirent.h>
40
41 struct krb5_plugin {
42 void *symbol;
43 void *dsohandle;
44 struct krb5_plugin *next;
45 };
46
47 struct plugin {
48 enum krb5_plugin_type type;
49 void *name;
50 void *symbol;
51 struct plugin *next;
52 };
53
54 static HEIMDAL_MUTEX plugin_mutex = HEIMDAL_MUTEX_INITIALIZER;
55 static struct plugin *registered = NULL;
56
57 static const char *plugin_dir = LIBDIR "/plugin/krb5";
58
59 /*
60 *
61 */
62
63 void *
64 _krb5_plugin_get_symbol(struct krb5_plugin *p)
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65 {
66 return p->symbol;
67 }
68
69 struct krb5_plugin *
70 _krb5_plugin_get_next(struct krb5_plugin *p)
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71 {
72 return p->next;
73 }
74
75 /*
76 *
77 */
78
79 #ifdef HAVE_DLOPEN
80
81 static krb5_error_code
82 loadlib(krb5_context context,
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83 enum krb5_plugin_type type,
84 const char *name,
85 const char *lib,
86 struct krb5_plugin **e)
87 {
88 *e = calloc(1, sizeof(**e));
89 if (*e == NULL) {
90 krb5_set_error_message(context, ENOMEM, "malloc: out of memory");
91 return ENOMEM;
92 }
93
94 #ifndef RTLD_LAZY
95 #define RTLD_LAZY 0
96 #endif
97
98 (*e)->dsohandle = dlopen(lib, RTLD_LAZY);
99 if ((*e)->dsohandle == NULL) {
100 free(*e);
101 *e = NULL;
102 krb5_set_error_message(context, ENOMEM, "Failed to load %s: %s",
103 lib, dlerror());
104 return ENOMEM;
105 }
106
107 /* dlsym doesn't care about the type */
108 (*e)->symbol = dlsym((*e)->dsohandle, name);
109 if ((*e)->symbol == NULL) {
110 dlclose((*e)->dsohandle);
111 free(*e);
112 krb5_clear_error_message(context);
113 return ENOMEM;
114 }
115
116 return 0;
117 }
118 #endif /* HAVE_DLOPEN */
119
120 /**
121 * Register a plugin symbol name of specific type.
122 * @param context a Keberos context
123 * @param type type of plugin symbol
124 * @param name name of plugin symbol
125 * @param symbol a pointer to the named symbol
126 * @return In case of error a non zero error com_err error is returned
127 * and the Kerberos error string is set.
128 *
129 * @ingroup krb5_support
130 */
131
132 krb5_error_code
133 krb5_plugin_register(krb5_context context,
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134 enum krb5_plugin_type type,
135 const char *name,
136 void *symbol)
137 {
138 struct plugin *e;
139
140 /* check for duplicates */
141 for (e = registered; e != NULL; e = e->next)
142 if (e->type == type && strcmp(e->name,name)== 0 && e->symbol == symbol)
143 return 0;
144
145 e = calloc(1, sizeof(*e));
146 if (e == NULL) {
147 krb5_set_error_message(context, ENOMEM, "malloc: out of memory");
148 return ENOMEM;
149 }
150 e->type = type;
151 e->name = strdup(name);
152 if (e->name == NULL) {
153 free(e);
154 krb5_set_error_message(context, ENOMEM, "malloc: out of memory");
155 return ENOMEM;
156 }
157 e->symbol = symbol;
158
159 HEIMDAL_MUTEX_lock(&plugin_mutex);
160 e->next = registered;
161 registered = e;
162 HEIMDAL_MUTEX_unlock(&plugin_mutex);
163
164 return 0;
165 }
166
167 krb5_error_code
168 _krb5_plugin_find(krb5_context context,
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169 enum krb5_plugin_type type,
170 const char *name,
171 struct krb5_plugin **list)
172 {
173 struct krb5_plugin *e;
174 struct plugin *p;
175 krb5_error_code ret;
176 char *sysdirs[2] = { NULL, NULL };
177 char **dirs = NULL, **di;
178 struct dirent *entry;
179 char *path;
180 DIR *d = NULL;
181
182 *list = NULL;
183
184 HEIMDAL_MUTEX_lock(&plugin_mutex);
185
186 for (p = registered; p != NULL; p = p->next) {
187 if (p->type != type || strcmp(p->name, name) != 0)
188 continue;
189
190 e = calloc(1, sizeof(*e));
191 if (e == NULL) {
192 HEIMDAL_MUTEX_unlock(&plugin_mutex);
193 ret = ENOMEM;
194 krb5_set_error_message(context, ret, "malloc: out of memory");
195 goto out;
196 }
197 e->symbol = p->symbol;
198 e->dsohandle = NULL;
199 e->next = *list;
200 *list = e;
201 }
202 HEIMDAL_MUTEX_unlock(&plugin_mutex);
203
204 #ifdef HAVE_DLOPEN
205
206 dirs = krb5_config_get_strings(context, NULL, "libdefaults",
207 "plugin_dir", NULL);
208 if (dirs == NULL) {
209 sysdirs[0] = rk_UNCONST(plugin_dir);
210 dirs = sysdirs;
211 }
212
213 for (di = dirs; *di != NULL; di++) {
214
215 d = opendir(*di);
216 if (d == NULL)
217 continue;
218 rk_cloexec(dirfd(d));
219
220 while ((entry = readdir(d)) != NULL) {
221 asprintf(&path, "%s/%s", *di, entry->d_name);
222 if (path == NULL) {
223 ret = ENOMEM;
224 krb5_set_error_message(context, ret, "malloc: out of memory");
225 goto out;
226 }
227 ret = loadlib(context, type, name, path, &e);
228 free(path);
229 if (ret)
230 continue;
231
232 e->next = *list;
233 *list = e;
234 }
235 closedir(d);
236 }
237 if (dirs != sysdirs)
238 krb5_config_free_strings(dirs);
239 #endif /* HAVE_DLOPEN */
240
241 if (*list == NULL) {
242 krb5_set_error_message(context, ENOENT, "Did not find a plugin for %s", name);
243 return ENOENT;
244 }
245
246 return 0;
247
248 out:
249 if (dirs && dirs != sysdirs)
250 krb5_config_free_strings(dirs);
251 if (d)
252 closedir(d);
253 _krb5_plugin_free(*list);
254 *list = NULL;
255
256 return ret;
257 }
258
259 void
260 _krb5_plugin_free(struct krb5_plugin *list)
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261 {
262 struct krb5_plugin *next;
263 while (list) {
264 next = list->next;
265 if (list->dsohandle)
266 dlclose(list->dsohandle);
267 free(list);
268 list = next;
269 }
270 }