xref: /illumos-gate/usr/src/lib/libbsm/common/audit_event.c (revision 657a8c206b913d1ee578fd725f0b25eca5b77253)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 
28 /*
29  * Interfaces to audit_event(5)  (/etc/security/audit_event)
30  */
31 
32 /*
33  * This routine is obsolete.  I have removed its inclusion by removing
34  * the .o from the makefile.  Please use cacheauevent() or any of the
35  * getauev* routines.
36  */
37 
38 #include <sys/types.h>
39 #include <limits.h>
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <string.h>
43 #include <bsm/audit.h>
44 #include <bsm/libbsm.h>
45 #include <synch.h>
46 
47 /*
48  *	Macros to produce a quoted string containing the value of a
49  *	preprocessor macro. For example, if SIZE is defined to be 256,
50  *	VAL2STR(SIZE) is "256". This is used to construct format
51  *	strings for scanf-family functions below.
52  */
53 #define	QUOTE(x)	#x
54 #define	VAL2STR(x)	QUOTE(x)
55 
56 static au_class_t flagstohex(char *);
57 
58 static char	au_event_fname[PATH_MAX] = AUDITEVENTFILE;
59 static FILE *au_event_file = (FILE *)0;
60 static mutex_t mutex_eventfile = DEFAULTMUTEX;
61 static mutex_t mutex_eventcache = DEFAULTMUTEX;
62 /*
63  * If an error occurs during the call to cacheauclassnam() inside
64  * flagstohex() any return value could be seen as a valid class mask so
65  * the following global variable, cacheauclass_failure, is set to indicate
66  * that an error has occurred.
67  */
68 static int cacheauclass_failure = 0;
69 
70 
71 void
72 setauevent()
73 {
74 	(void) mutex_lock(&mutex_eventfile);
75 	if (au_event_file) {
76 		(void) fseek(au_event_file, 0L, 0);
77 	}
78 	(void) mutex_unlock(&mutex_eventfile);
79 }
80 
81 
82 void
83 endauevent()
84 {
85 	(void) mutex_lock(&mutex_eventfile);
86 	if (au_event_file) {
87 		(void) fclose(au_event_file);
88 		au_event_file = (FILE *)0;
89 	}
90 	(void) mutex_unlock(&mutex_eventfile);
91 }
92 
93 au_event_ent_t *
94 getauevent()
95 {
96 	static au_event_ent_t au_event_entry;
97 	static char	ename[AU_EVENT_NAME_MAX];
98 	static char	edesc[AU_EVENT_DESC_MAX];
99 
100 	/* initialize au_event_entry structure */
101 	au_event_entry.ae_name = ename;
102 	au_event_entry.ae_desc = edesc;
103 
104 	return (getauevent_r(&au_event_entry));
105 }
106 
107 au_event_ent_t *
108 getauevent_r(au_event_entry)
109 	au_event_ent_t *au_event_entry;
110 {
111 	int	i, error = 0, found = 0;
112 	char	*s, input[AU_EVENT_LINE_MAX];
113 	char	trim_buf[AU_EVENT_NAME_MAX+1];
114 
115 	/* open audit event file if it isn't already */
116 	(void) mutex_lock(&mutex_eventfile);
117 	if (!au_event_file)
118 		if (!(au_event_file = fopen(au_event_fname, "rF"))) {
119 			(void) mutex_unlock(&mutex_eventfile);
120 			return (NULL);
121 		}
122 
123 	while (fgets(input, AU_EVENT_LINE_MAX, au_event_file)) {
124 		if (input[0] != '#') {
125 			s = input + strspn(input, " \t\r\n");
126 			if ((*s == '\0') || (*s == '#')) {
127 				continue;
128 			}
129 			found = 1;
130 			s = input;
131 
132 			/* parse number */
133 			i = strcspn(s, ":");
134 			s[i] = '\0';
135 			(void) sscanf(s, "%hu", &au_event_entry->ae_number);
136 			s = &s[i+1];
137 
138 			/* parse event name */
139 			i = strcspn(s, ":");
140 			s[i] = '\0';
141 			(void) sscanf(s, "%" VAL2STR(AU_EVENT_NAME_MAX) "s",
142 			    trim_buf);
143 			(void) strncpy(au_event_entry->ae_name, trim_buf,
144 				AU_EVENT_NAME_MAX);
145 			s = &s[i+1];
146 
147 			/* parse event description */
148 			i = strcspn(s, ":");
149 			s[i] = '\0';
150 			(void) strncpy(au_event_entry->ae_desc, s,
151 				AU_EVENT_DESC_MAX);
152 			s = &s[i+1];
153 
154 			/* parse class */
155 			i = strcspn(s, "\n\0");
156 			s[i] = '\0';
157 			(void) sscanf(s, "%" VAL2STR(AU_EVENT_NAME_MAX) "s",
158 			    trim_buf);
159 			au_event_entry->ae_class = flagstohex(trim_buf);
160 			if (cacheauclass_failure == 1) {
161 				error = 1;
162 				cacheauclass_failure = 0;
163 			}
164 
165 			break;
166 		}
167 	}
168 	(void) mutex_unlock(&mutex_eventfile);
169 
170 	if (!error && found) {
171 		return (au_event_entry);
172 	} else {
173 		return (NULL);
174 	}
175 }
176 
177 
178 au_event_ent_t *
179 getauevnam(char *name)
180 {
181 	static au_event_ent_t au_event_entry;
182 	static char	ename[AU_EVENT_NAME_MAX];
183 	static char	edesc[AU_EVENT_DESC_MAX];
184 
185 	/* initialize au_event_entry structure */
186 	au_event_entry.ae_name = ename;
187 	au_event_entry.ae_desc = edesc;
188 
189 	return (getauevnam_r(&au_event_entry, name));
190 }
191 
192 au_event_ent_t *
193 getauevnam_r(au_event_ent_t *e, char *name)
194 {
195 	setauevent();
196 	while (getauevent_r(e) != NULL) {
197 		if (strcmp(e->ae_name, name) == 0) {
198 			endauevent();
199 			return (e);
200 		}
201 	}
202 	endauevent();
203 	return (NULL);
204 }
205 
206 au_event_ent_t *
207 getauevnum_r(au_event_ent_t *e, au_event_t event_number)
208 {
209 	setauevent();
210 	while (getauevent_r(e) != NULL) {
211 		if (e->ae_number == event_number) {
212 			endauevent();
213 			return (e);
214 		}
215 	}
216 	endauevent();
217 	return (NULL);
218 }
219 
220 au_event_ent_t *
221 getauevnum(au_event_t event_number)
222 {
223 	static au_event_ent_t e;
224 	static char	ename[AU_EVENT_NAME_MAX];
225 	static char	edesc[AU_EVENT_DESC_MAX];
226 
227 	/* initialize au_event_entry structure */
228 	e.ae_name = ename;
229 	e.ae_desc = edesc;
230 
231 	return (getauevnum_r(&e, event_number));
232 }
233 
234 au_event_t
235 getauevnonam(char *event_name)
236 {
237 	au_event_ent_t e;
238 	char ename[AU_EVENT_NAME_MAX];
239 	char edesc[AU_EVENT_DESC_MAX];
240 
241 	/* initialize au_event_entry structure */
242 	e.ae_name = ename;
243 	e.ae_desc = edesc;
244 
245 	if (getauevnam_r(&e, event_name) == NULL) {
246 		return (0);
247 	}
248 	return (e.ae_number);
249 }
250 
251 /*
252  * cacheauevent:
253  *	Read the entire audit_event file into memory.
254  *	Set a pointer to the requested entry in the cache
255  *	or a pointer to an invalid entry if the event number
256  *	is not known.
257  *
258  *	Return < 0, if error.
259  *	Return   0, if event number not in cache.
260  *	Return   1, if event number is in cache.
261  */
262 
263 int
264 cacheauevent(au_event_ent_t **result, au_event_t event_number)
265 {
266 	static au_event_t max; /* the highest event number in the file */
267 	static au_event_t min; /* the lowest event number in the file */
268 	static int	invalid; /* 1+index of the highest event number */
269 	static au_event_ent_t **index_tbl;
270 	static au_event_ent_t **p_tbl;
271 	static int	called_once = 0;
272 
273 	char	line[AU_EVENT_LINE_MAX];
274 	int	lines = 0;
275 	FILE	*fp;
276 	au_event_ent_t *p_event;
277 	int	i, size;
278 	int	hit = 0;
279 	char	*s;
280 
281 	(void) mutex_lock(&mutex_eventcache);
282 	if (called_once == 0) {
283 
284 		/* Count number of lines in the events file */
285 		if ((fp = fopen(au_event_fname, "rF")) == NULL) {
286 			(void) mutex_unlock(&mutex_eventcache);
287 			return (-1);
288 		}
289 		while (fgets(line, AU_EVENT_LINE_MAX, fp) != NULL) {
290 			s = line + strspn(line, " \t\r\n");
291 			if ((*s == '\0') || (*s == '#')) {
292 				continue;
293 			}
294 			lines++;
295 		}
296 		(void) fclose(fp);
297 		size = lines;
298 
299 		/*
300 		 * Make an array in which each element in an entry in the
301 		 * events file.  Make the next to last element an invalid
302 		 * event.  Make the last element a NULL pointer.
303 		 */
304 
305 		p_tbl = calloc(lines + 1, sizeof (au_event_ent_t));
306 		if (p_tbl == NULL) {
307 			(void) mutex_unlock(&mutex_eventcache);
308 			return (-2);
309 		}
310 		lines = 0;
311 		max = 0;
312 		min = 65535;
313 		setauevent();
314 		while ((p_event = getauevent()) != NULL) {
315 			p_tbl[lines] = (au_event_ent_t *)
316 				malloc(sizeof (au_event_ent_t));
317 			if (p_tbl[lines] == NULL) {
318 				(void) mutex_unlock(&mutex_eventcache);
319 				return (-3);
320 			}
321 			p_tbl[lines]->ae_number = p_event->ae_number;
322 			p_tbl[lines]->ae_name   = strdup(p_event->ae_name);
323 			p_tbl[lines]->ae_desc   = strdup(p_event->ae_desc);
324 			p_tbl[lines]->ae_class  = p_event->ae_class;
325 #ifdef DEBUG2
326 			printevent(p_tbl[lines]);
327 #endif
328 			if (p_event->ae_number > max) {
329 				max = p_event->ae_number;
330 			}
331 			if (p_event->ae_number < min) {
332 				min = p_event->ae_number;
333 			}
334 			lines++;
335 		}
336 		endauevent();
337 		invalid = lines;
338 		p_tbl[invalid] = (au_event_ent_t *)
339 			malloc(sizeof (au_event_ent_t));
340 		if (p_tbl[invalid] == NULL) {
341 			(void) mutex_unlock(&mutex_eventcache);
342 			return (-4);
343 		}
344 		p_tbl[invalid]->ae_number = (au_event_t)-1;
345 		p_tbl[invalid]->ae_name   = "invalid event number";
346 		p_tbl[invalid]->ae_desc   = p_tbl[invalid]->ae_name;
347 		p_tbl[invalid]->ae_class  = (au_class_t)-1;
348 
349 #ifdef DEBUG2
350 		for (i = 0; i < size; i++) {
351 			printf("%d:%s:%s:%d\n", p_tbl[i]->ae_number,
352 				p_tbl[i]->ae_name, p_tbl[i]->ae_desc,
353 				p_tbl[i]->ae_class);
354 		}
355 #endif
356 
357 		/* get space for the index_tbl */
358 		index_tbl = calloc(max+1, sizeof (au_event_ent_t *));
359 		if (index_tbl == NULL) {
360 			(void) mutex_unlock(&mutex_eventcache);
361 			return (-5);
362 		}
363 
364 		/* intialize the index_tbl to the invalid event number */
365 		for (i = 0; (au_event_t)i < max; i++) {
366 			index_tbl[i] = p_tbl[invalid];
367 		}
368 
369 		/* point each index_tbl element at the corresponding event */
370 		for (i = 0; i < size; i++) {
371 			index_tbl[p_tbl[i]->ae_number] = p_tbl[i];
372 		}
373 
374 		called_once = 1;
375 
376 	}
377 
378 	if (event_number > max || event_number < min) {
379 		*result = index_tbl[invalid];
380 	} else {
381 		*result = index_tbl[event_number];
382 		hit = 1;
383 	}
384 	(void) mutex_unlock(&mutex_eventcache);
385 	return (hit);
386 }
387 
388 
389 static au_class_t
390 flagstohex(char *flags)
391 {
392 	au_class_ent_t *p_class;
393 	au_class_t	hex = 0;
394 	char	*comma = ",";
395 	char	*s;
396 	char	*last;
397 
398 	s = strtok_r(flags, comma, &last);
399 	while (s != NULL) {
400 		if ((cacheauclassnam(&p_class, s)) < 0) {
401 			cacheauclass_failure = 1;
402 			return ((au_class_t)-1);
403 		}
404 		hex |= p_class->ac_class;
405 		s = strtok_r(NULL, comma, &last);
406 	}
407 	return (hex);
408 }
409 
410 
411 #ifdef DEBUG2
412 void
413 printevent(p_event)
414 au_event_ent_t *p_event;
415 {
416 	printf("%d:%s:%s:%d\n", p_event->ae_number, p_event->ae_name,
417 		p_event->ae_desc, p_event->ae_class);
418 	fflush(stdout);
419 }
420 
421 
422 #endif
423