xref: /freebsd/contrib/openbsm/libbsm/bsm_class.c (revision 9a14aa017b21c292740c00ee098195cd46642730)
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 Computer, 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  * $P4: //depot/projects/trustedbsd/openbsm/libbsm/bsm_class.c#15 $
31  */
32 
33 #include <config/config.h>
34 
35 #include <bsm/libbsm.h>
36 
37 #include <string.h>
38 #ifdef HAVE_PTHREAD_MUTEX_LOCK
39 #include <pthread.h>
40 #endif
41 #include <stdio.h>
42 #include <stdlib.h>
43 
44 #ifndef HAVE_STRLCPY
45 #include <compat/strlcpy.h>
46 #endif
47 
48 /*
49  * Parse the contents of the audit_class file to return struct au_class_ent
50  * entries.
51  */
52 static FILE		*fp = NULL;
53 static char		 linestr[AU_LINE_MAX];
54 static const char	*classdelim = ":";
55 
56 #ifdef HAVE_PTHREAD_MUTEX_LOCK
57 static pthread_mutex_t	mutex = PTHREAD_MUTEX_INITIALIZER;
58 #endif
59 
60 /*
61  * Parse a single line from the audit_class file passed in str to the struct
62  * au_class_ent elements; store the result in c.
63  */
64 static struct au_class_ent *
65 classfromstr(char *str, struct au_class_ent *c)
66 {
67 	char *classname, *classdesc, *classflag;
68 	char *last;
69 
70 	/* Each line contains flag:name:desc. */
71 	classflag = strtok_r(str, classdelim, &last);
72 	classname = strtok_r(NULL, classdelim, &last);
73 	classdesc = strtok_r(NULL, classdelim, &last);
74 
75 	if ((classflag == NULL) || (classname == NULL) || (classdesc == NULL))
76 		return (NULL);
77 
78 	/*
79 	 * Check for very large classnames.
80 	 */
81 	if (strlen(classname) >= AU_CLASS_NAME_MAX)
82 		return (NULL);
83 	strlcpy(c->ac_name, classname, AU_CLASS_NAME_MAX);
84 
85 	/*
86 	 * Check for very large class description.
87 	 */
88 	if (strlen(classdesc) >= AU_CLASS_DESC_MAX)
89 		return (NULL);
90 	strlcpy(c->ac_desc, classdesc, AU_CLASS_DESC_MAX);
91 	c->ac_class = strtoul(classflag, (char **) NULL, 0);
92 
93 	return (c);
94 }
95 
96 /*
97  * Return the next au_class_ent structure from the file setauclass should be
98  * called before invoking this function for the first time.
99  *
100  * Must be called with mutex held.
101  */
102 static struct au_class_ent *
103 getauclassent_r_locked(struct au_class_ent *c)
104 {
105 	char *tokptr, *nl;
106 
107 	if ((fp == NULL) && ((fp = fopen(AUDIT_CLASS_FILE, "r")) == NULL))
108 		return (NULL);
109 
110 	/*
111 	 * Read until next non-comment line is found, or EOF.
112 	 */
113 	while (1) {
114 		if (fgets(linestr, AU_LINE_MAX, fp) == NULL)
115 			return (NULL);
116 
117 		/* Skip comments. */
118 		if (linestr[0] == '#')
119 			continue;
120 
121 		/* Remove trailing new line character. */
122 		if ((nl = strrchr(linestr, '\n')) != NULL)
123 			*nl = '\0';
124 
125 		/* Parse tokptr to au_class_ent components. */
126 		tokptr = linestr;
127 		if (classfromstr(tokptr, c) == NULL)
128 			return (NULL);
129 		break;
130 	}
131 
132 	return (c);
133 }
134 
135 struct au_class_ent *
136 getauclassent_r(struct au_class_ent *c)
137 {
138 	struct au_class_ent *cp;
139 
140 #ifdef HAVE_PTHREAD_MUTEX_LOCK
141 	pthread_mutex_lock(&mutex);
142 #endif
143 	cp = getauclassent_r_locked(c);
144 #ifdef HAVE_PTHREAD_MUTEX_LOCK
145 	pthread_mutex_unlock(&mutex);
146 #endif
147 	return (cp);
148 }
149 
150 struct au_class_ent *
151 getauclassent(void)
152 {
153 	static char class_ent_name[AU_CLASS_NAME_MAX];
154 	static char class_ent_desc[AU_CLASS_DESC_MAX];
155 	static struct au_class_ent c, *cp;
156 
157 	bzero(&c, sizeof(c));
158 	bzero(class_ent_name, sizeof(class_ent_name));
159 	bzero(class_ent_desc, sizeof(class_ent_desc));
160 	c.ac_name = class_ent_name;
161 	c.ac_desc = class_ent_desc;
162 
163 #ifdef HAVE_PTHREAD_MUTEX_LOCK
164 	pthread_mutex_lock(&mutex);
165 #endif
166 	cp = getauclassent_r_locked(&c);
167 #ifdef HAVE_PTHREAD_MUTEX_LOCK
168 	pthread_mutex_unlock(&mutex);
169 #endif
170 	return (cp);
171 }
172 
173 /*
174  * Rewind to the beginning of the enumeration.
175  *
176  * Must be called with mutex held.
177  */
178 static void
179 setauclass_locked(void)
180 {
181 
182 	if (fp != NULL)
183 		fseek(fp, 0, SEEK_SET);
184 }
185 
186 void
187 setauclass(void)
188 {
189 
190 #ifdef HAVE_PTHREAD_MUTEX_LOCK
191 	pthread_mutex_lock(&mutex);
192 #endif
193 	setauclass_locked();
194 #ifdef HAVE_PTHREAD_MUTEX_LOCK
195 	pthread_mutex_unlock(&mutex);
196 #endif
197 }
198 
199 /*
200  * Return the next au_class_entry having the given class name.
201  */
202 struct au_class_ent *
203 getauclassnam_r(struct au_class_ent *c, const char *name)
204 {
205 	struct au_class_ent *cp;
206 
207 	if (name == NULL)
208 		return (NULL);
209 
210 #ifdef HAVE_PTHREAD_MUTEX_LOCK
211 	pthread_mutex_lock(&mutex);
212 #endif
213 	setauclass_locked();
214 	while ((cp = getauclassent_r_locked(c)) != NULL) {
215 		if (strcmp(name, cp->ac_name) == 0) {
216 #ifdef HAVE_PTHREAD_MUTEX_LOCK
217 			pthread_mutex_unlock(&mutex);
218 #endif
219 			return (cp);
220 		}
221 	}
222 #ifdef HAVE_PTHREAD_MUTEX_LOCK
223 	pthread_mutex_unlock(&mutex);
224 #endif
225 	return (NULL);
226 }
227 
228 struct au_class_ent *
229 getauclassnam(const char *name)
230 {
231 	static char class_ent_name[AU_CLASS_NAME_MAX];
232 	static char class_ent_desc[AU_CLASS_DESC_MAX];
233 	static struct au_class_ent c;
234 
235 	bzero(&c, sizeof(c));
236 	bzero(class_ent_name, sizeof(class_ent_name));
237 	bzero(class_ent_desc, sizeof(class_ent_desc));
238 	c.ac_name = class_ent_name;
239 	c.ac_desc = class_ent_desc;
240 
241 	return (getauclassnam_r(&c, name));
242 }
243 
244 
245 /*
246  * Return the next au_class_entry having the given class number.
247  *
248  * OpenBSM extension.
249  */
250 struct au_class_ent *
251 getauclassnum_r(struct au_class_ent *c, au_class_t class_number)
252 {
253 	struct au_class_ent *cp;
254 
255 #ifdef HAVE_PTHREAD_MUTEX_LOCK
256 	pthread_mutex_lock(&mutex);
257 #endif
258 	setauclass_locked();
259 	while ((cp = getauclassent_r_locked(c)) != NULL) {
260 		if (class_number == cp->ac_class)
261 			return (cp);
262 	}
263 #ifdef HAVE_PTHREAD_MUTEX_LOCK
264 	pthread_mutex_unlock(&mutex);
265 #endif
266 	return (NULL);
267 }
268 
269 struct au_class_ent *
270 getauclassnum(au_class_t class_number)
271 {
272 	static char class_ent_name[AU_CLASS_NAME_MAX];
273 	static char class_ent_desc[AU_CLASS_DESC_MAX];
274 	static struct au_class_ent c;
275 
276 	bzero(&c, sizeof(c));
277 	bzero(class_ent_name, sizeof(class_ent_name));
278 	bzero(class_ent_desc, sizeof(class_ent_desc));
279 	c.ac_name = class_ent_name;
280 	c.ac_desc = class_ent_desc;
281 
282 	return (getauclassnum_r(&c, class_number));
283 }
284 
285 /*
286  * audit_class processing is complete; close any open files.
287  */
288 void
289 endauclass(void)
290 {
291 
292 #ifdef HAVE_PTHREAD_MUTEX_LOCK
293 	pthread_mutex_lock(&mutex);
294 #endif
295 	if (fp != NULL) {
296 		fclose(fp);
297 		fp = NULL;
298 	}
299 #ifdef HAVE_PTHREAD_MUTEX_LOCK
300 	pthread_mutex_unlock(&mutex);
301 #endif
302 }
303