xref: /freebsd/contrib/openbsm/libbsm/bsm_class.c (revision a70cba95822f662d3f9da5119b6a0c433e8f70af)
1 /*-
2  * Copyright (c) 2004 Apple Inc.
3  * Copyright (c) 2006 Robert N. M. Watson
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  * 1.  Redistributions of source code must retain the above copyright
10  *     notice, this list of conditions and the following disclaimer.
11  * 2.  Redistributions in binary form must reproduce the above copyright
12  *     notice, this list of conditions and the following disclaimer in the
13  *     documentation and/or other materials provided with the distribution.
14  * 3.  Neither the name of Apple Inc. ("Apple") nor the names of
15  *     its contributors may be used to endorse or promote products derived
16  *     from this software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR
22  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
26  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
27  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28  * POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 #include <config/config.h>
32 
33 #include <bsm/libbsm.h>
34 
35 #include <string.h>
36 #ifdef HAVE_PTHREAD_MUTEX_LOCK
37 #include <pthread.h>
38 #endif
39 #include <stdio.h>
40 #include <stdlib.h>
41 
42 #ifndef HAVE_STRLCPY
43 #include <compat/strlcpy.h>
44 #endif
45 
46 /*
47  * Parse the contents of the audit_class file to return struct au_class_ent
48  * entries.
49  */
50 static FILE		*fp = NULL;
51 static char		 linestr[AU_LINE_MAX];
52 static const char	*classdelim = ":";
53 
54 #ifdef HAVE_PTHREAD_MUTEX_LOCK
55 static pthread_mutex_t	mutex = PTHREAD_MUTEX_INITIALIZER;
56 #endif
57 
58 /*
59  * Parse a single line from the audit_class file passed in str to the struct
60  * au_class_ent elements; store the result in c.
61  */
62 static struct au_class_ent *
63 classfromstr(char *str, struct au_class_ent *c)
64 {
65 	char *classname, *classdesc, *classflag;
66 	char *last;
67 
68 	/* Each line contains flag:name:desc. */
69 	classflag = strtok_r(str, classdelim, &last);
70 	classname = strtok_r(NULL, classdelim, &last);
71 	classdesc = strtok_r(NULL, classdelim, &last);
72 
73 	if ((classflag == NULL) || (classname == NULL) || (classdesc == NULL))
74 		return (NULL);
75 
76 	/*
77 	 * Check for very large classnames.
78 	 */
79 	if (strlen(classname) >= AU_CLASS_NAME_MAX)
80 		return (NULL);
81 	strlcpy(c->ac_name, classname, AU_CLASS_NAME_MAX);
82 
83 	/*
84 	 * Check for very large class description.
85 	 */
86 	if (strlen(classdesc) >= AU_CLASS_DESC_MAX)
87 		return (NULL);
88 	strlcpy(c->ac_desc, classdesc, AU_CLASS_DESC_MAX);
89 	c->ac_class = strtoul(classflag, (char **) NULL, 0);
90 
91 	return (c);
92 }
93 
94 /*
95  * Return the next au_class_ent structure from the file setauclass should be
96  * called before invoking this function for the first time.
97  *
98  * Must be called with mutex held.
99  */
100 static struct au_class_ent *
101 getauclassent_r_locked(struct au_class_ent *c)
102 {
103 	char *tokptr, *nl;
104 
105 	if ((fp == NULL) && ((fp = fopen(AUDIT_CLASS_FILE, "r")) == NULL))
106 		return (NULL);
107 
108 	/*
109 	 * Read until next non-comment line is found, or EOF.
110 	 */
111 	while (1) {
112 		if (fgets(linestr, AU_LINE_MAX, fp) == NULL)
113 			return (NULL);
114 
115 		/* Skip comments. */
116 		if (linestr[0] == '#')
117 			continue;
118 
119 		/* Remove trailing new line character. */
120 		if ((nl = strrchr(linestr, '\n')) != NULL)
121 			*nl = '\0';
122 
123 		/* Parse tokptr to au_class_ent components. */
124 		tokptr = linestr;
125 		if (classfromstr(tokptr, c) == NULL)
126 			return (NULL);
127 		break;
128 	}
129 
130 	return (c);
131 }
132 
133 struct au_class_ent *
134 getauclassent_r(struct au_class_ent *c)
135 {
136 	struct au_class_ent *cp;
137 
138 #ifdef HAVE_PTHREAD_MUTEX_LOCK
139 	pthread_mutex_lock(&mutex);
140 #endif
141 	cp = getauclassent_r_locked(c);
142 #ifdef HAVE_PTHREAD_MUTEX_LOCK
143 	pthread_mutex_unlock(&mutex);
144 #endif
145 	return (cp);
146 }
147 
148 struct au_class_ent *
149 getauclassent(void)
150 {
151 	static char class_ent_name[AU_CLASS_NAME_MAX];
152 	static char class_ent_desc[AU_CLASS_DESC_MAX];
153 	static struct au_class_ent c, *cp;
154 
155 	bzero(&c, sizeof(c));
156 	bzero(class_ent_name, sizeof(class_ent_name));
157 	bzero(class_ent_desc, sizeof(class_ent_desc));
158 	c.ac_name = class_ent_name;
159 	c.ac_desc = class_ent_desc;
160 
161 #ifdef HAVE_PTHREAD_MUTEX_LOCK
162 	pthread_mutex_lock(&mutex);
163 #endif
164 	cp = getauclassent_r_locked(&c);
165 #ifdef HAVE_PTHREAD_MUTEX_LOCK
166 	pthread_mutex_unlock(&mutex);
167 #endif
168 	return (cp);
169 }
170 
171 /*
172  * Rewind to the beginning of the enumeration.
173  *
174  * Must be called with mutex held.
175  */
176 static void
177 setauclass_locked(void)
178 {
179 
180 	if (fp != NULL)
181 		fseek(fp, 0, SEEK_SET);
182 }
183 
184 void
185 setauclass(void)
186 {
187 
188 #ifdef HAVE_PTHREAD_MUTEX_LOCK
189 	pthread_mutex_lock(&mutex);
190 #endif
191 	setauclass_locked();
192 #ifdef HAVE_PTHREAD_MUTEX_LOCK
193 	pthread_mutex_unlock(&mutex);
194 #endif
195 }
196 
197 /*
198  * Return the next au_class_entry having the given class name.
199  */
200 struct au_class_ent *
201 getauclassnam_r(struct au_class_ent *c, const char *name)
202 {
203 	struct au_class_ent *cp;
204 
205 	if (name == NULL)
206 		return (NULL);
207 
208 #ifdef HAVE_PTHREAD_MUTEX_LOCK
209 	pthread_mutex_lock(&mutex);
210 #endif
211 	setauclass_locked();
212 	while ((cp = getauclassent_r_locked(c)) != NULL) {
213 		if (strcmp(name, cp->ac_name) == 0) {
214 #ifdef HAVE_PTHREAD_MUTEX_LOCK
215 			pthread_mutex_unlock(&mutex);
216 #endif
217 			return (cp);
218 		}
219 	}
220 #ifdef HAVE_PTHREAD_MUTEX_LOCK
221 	pthread_mutex_unlock(&mutex);
222 #endif
223 	return (NULL);
224 }
225 
226 struct au_class_ent *
227 getauclassnam(const char *name)
228 {
229 	static char class_ent_name[AU_CLASS_NAME_MAX];
230 	static char class_ent_desc[AU_CLASS_DESC_MAX];
231 	static struct au_class_ent c;
232 
233 	bzero(&c, sizeof(c));
234 	bzero(class_ent_name, sizeof(class_ent_name));
235 	bzero(class_ent_desc, sizeof(class_ent_desc));
236 	c.ac_name = class_ent_name;
237 	c.ac_desc = class_ent_desc;
238 
239 	return (getauclassnam_r(&c, name));
240 }
241 
242 
243 /*
244  * Return the next au_class_entry having the given class number.
245  *
246  * OpenBSM extension.
247  */
248 struct au_class_ent *
249 getauclassnum_r(struct au_class_ent *c, au_class_t class_number)
250 {
251 	struct au_class_ent *cp;
252 
253 #ifdef HAVE_PTHREAD_MUTEX_LOCK
254 	pthread_mutex_lock(&mutex);
255 #endif
256 	setauclass_locked();
257 	while ((cp = getauclassent_r_locked(c)) != NULL) {
258 		if (class_number == cp->ac_class)
259 			return (cp);
260 	}
261 #ifdef HAVE_PTHREAD_MUTEX_LOCK
262 	pthread_mutex_unlock(&mutex);
263 #endif
264 	return (NULL);
265 }
266 
267 struct au_class_ent *
268 getauclassnum(au_class_t class_number)
269 {
270 	static char class_ent_name[AU_CLASS_NAME_MAX];
271 	static char class_ent_desc[AU_CLASS_DESC_MAX];
272 	static struct au_class_ent c;
273 
274 	bzero(&c, sizeof(c));
275 	bzero(class_ent_name, sizeof(class_ent_name));
276 	bzero(class_ent_desc, sizeof(class_ent_desc));
277 	c.ac_name = class_ent_name;
278 	c.ac_desc = class_ent_desc;
279 
280 	return (getauclassnum_r(&c, class_number));
281 }
282 
283 /*
284  * audit_class processing is complete; close any open files.
285  */
286 void
287 endauclass(void)
288 {
289 
290 #ifdef HAVE_PTHREAD_MUTEX_LOCK
291 	pthread_mutex_lock(&mutex);
292 #endif
293 	if (fp != NULL) {
294 		fclose(fp);
295 		fp = NULL;
296 	}
297 #ifdef HAVE_PTHREAD_MUTEX_LOCK
298 	pthread_mutex_unlock(&mutex);
299 #endif
300 }
301