xref: /illumos-gate/usr/src/lib/libbsm/common/audit_event.c (revision e4163c9bf1c1d30987c9216473236d730dc3c3a9)
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 #pragma ident	"%Z%%M%	%I%	%E% SMI"
22 
23 #ifndef lint
24 static char	sccsid[] = "%Z%%M% %I% %E% SMI";
25 #endif
26 
27 /*
28  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
29  * Use is subject to license terms.
30  */
31 
32 /*
33  * Interfaces to audit_event(5)  (/etc/security/audit_event)
34  */
35 
36 /*
37  * This routine is obsolete.  I have removed its inclusion by removing
38  * the .o from the makefile.  Please use cacheauevent() or any of the
39  * getauev* routines.
40  */
41 
42 #include <sys/types.h>
43 #include <limits.h>
44 #include <stdio.h>
45 #include <stdlib.h>
46 #include <string.h>
47 #include <bsm/audit.h>
48 #include <bsm/libbsm.h>
49 #include <synch.h>
50 
51 /*
52  *	Macros to produce a quoted string containing the value of a
53  *	preprocessor macro. For example, if SIZE is defined to be 256,
54  *	VAL2STR(SIZE) is "256". This is used to construct format
55  *	strings for scanf-family functions below.
56  */
57 #define	QUOTE(x)	#x
58 #define	VAL2STR(x)	QUOTE(x)
59 
60 static au_class_t flagstohex(char *);
61 
62 static char	au_event_fname[PATH_MAX] = AUDITEVENTFILE;
63 static FILE *au_event_file = (FILE *)0;
64 static mutex_t mutex_eventfile = DEFAULTMUTEX;
65 static mutex_t mutex_eventcache = DEFAULTMUTEX;
66 /*
67  * If an error occurs during the call to cacheauclassnam() inside
68  * flagstohex() any return value could be seen as a valid class mask so
69  * the following global variable, cacheauclass_failure, is set to indicate
70  * that an error has occurred.
71  */
72 static int cacheauclass_failure = 0;
73 
74 extern int _mutex_lock(mutex_t *);
75 extern int _mutex_unlock(mutex_t *);
76 
77 int
78 #ifdef __STDC__
79 setaueventfile(char *fname)
80 #else
81 setaueventfile(fname)
82 	char	*fname;
83 #endif
84 {
85 	_mutex_lock(&mutex_eventfile);
86 	if (fname) {
87 		(void) strcpy(au_event_fname, fname);
88 	}
89 	_mutex_unlock(&mutex_eventfile);
90 	return (0);
91 }
92 
93 
94 void
95 setauevent()
96 {
97 	_mutex_lock(&mutex_eventfile);
98 	if (au_event_file) {
99 		(void) fseek(au_event_file, 0L, 0);
100 	}
101 	_mutex_unlock(&mutex_eventfile);
102 }
103 
104 
105 void
106 endauevent()
107 {
108 	_mutex_lock(&mutex_eventfile);
109 	if (au_event_file) {
110 		(void) fclose(au_event_file);
111 		au_event_file = (FILE *)0;
112 	}
113 	_mutex_unlock(&mutex_eventfile);
114 }
115 
116 au_event_ent_t *
117 getauevent()
118 {
119 	static au_event_ent_t au_event_entry;
120 	static char	ename[AU_EVENT_NAME_MAX];
121 	static char	edesc[AU_EVENT_DESC_MAX];
122 
123 	/* initialize au_event_entry structure */
124 	au_event_entry.ae_name = ename;
125 	au_event_entry.ae_desc = edesc;
126 
127 	return (getauevent_r(&au_event_entry));
128 }
129 
130 au_event_ent_t *
131 getauevent_r(au_event_entry)
132 	au_event_ent_t *au_event_entry;
133 {
134 	int	i, error = 0, found = 0;
135 	char	*s, input[AU_EVENT_LINE_MAX];
136 	char	trim_buf[AU_EVENT_NAME_MAX+1];
137 
138 	/* open audit event file if it isn't already */
139 	_mutex_lock(&mutex_eventfile);
140 	if (!au_event_file)
141 		if (!(au_event_file = fopen(au_event_fname, "rF"))) {
142 			_mutex_unlock(&mutex_eventfile);
143 			return ((au_event_ent_t *)0);
144 		}
145 
146 	while (fgets(input, AU_EVENT_LINE_MAX, au_event_file)) {
147 		if (input[0] != '#') {
148 			s = input + strspn(input, " \t\r\n");
149 			if ((*s == '\0') || (*s == '#')) {
150 				continue;
151 			}
152 			found = 1;
153 			s = input;
154 
155 			/* parse number */
156 			i = strcspn(s, ":");
157 			s[i] = '\0';
158 			(void) sscanf(s, "%hd", &au_event_entry->ae_number);
159 			s = &s[i+1];
160 
161 			/* parse event name */
162 			i = strcspn(s, ":");
163 			s[i] = '\0';
164 			(void) sscanf(s, "%" VAL2STR(AU_EVENT_NAME_MAX) "s",
165 			    trim_buf);
166 			(void) strncpy(au_event_entry->ae_name, trim_buf,
167 				AU_EVENT_NAME_MAX);
168 			s = &s[i+1];
169 
170 			/* parse event description */
171 			i = strcspn(s, ":");
172 			s[i] = '\0';
173 			(void) strncpy(au_event_entry->ae_desc, s,
174 				AU_EVENT_DESC_MAX);
175 			s = &s[i+1];
176 
177 			/* parse class */
178 			i = strcspn(s, "\n\0");
179 			s[i] = '\0';
180 			(void) sscanf(s, "%" VAL2STR(AU_EVENT_NAME_MAX) "s",
181 			    trim_buf);
182 			au_event_entry->ae_class = flagstohex(trim_buf);
183 			if (cacheauclass_failure == 1) {
184 				error = 1;
185 				cacheauclass_failure = 0;
186 			}
187 
188 			break;
189 		}
190 	}
191 	_mutex_unlock(&mutex_eventfile);
192 
193 	if (!error && found) {
194 		return (au_event_entry);
195 	} else {
196 		return ((au_event_ent_t *)0);
197 	}
198 }
199 
200 
201 au_event_ent_t *
202 #ifdef __STDC__
203 getauevnam(char *name)
204 #else
205 getauevnam(name)
206 	char *name;
207 #endif
208 {
209 	static au_event_ent_t au_event_entry;
210 	static char	ename[AU_EVENT_NAME_MAX];
211 	static char	edesc[AU_EVENT_DESC_MAX];
212 
213 	/* initialize au_event_entry structure */
214 	au_event_entry.ae_name = ename;
215 	au_event_entry.ae_desc = edesc;
216 
217 	return (getauevnam_r(&au_event_entry, name));
218 }
219 
220 au_event_ent_t *
221 #ifdef __STDC__
222 getauevnam_r(au_event_ent_t *e, char *name)
223 #else
224 getauevnam_r(e, name)
225 	au_event_ent_t &e;
226 	char *name;
227 #endif
228 {
229 	setauevent();
230 	while (getauevent_r(e) != NULL) {
231 		if (strcmp(e->ae_name, name) == 0) {
232 			endauevent();
233 			return (e);
234 		}
235 	}
236 	endauevent();
237 	return ((au_event_ent_t *)NULL);
238 }
239 
240 au_event_ent_t *
241 #ifdef __STDC__
242 getauevnum_r(au_event_ent_t *e, au_event_t event_number)
243 #else
244 getauevnum_r(e, event_number)
245 	au_event_ent_t *e;
246 	au_event_t event_number;
247 #endif
248 {
249 	setauevent();
250 	while (getauevent_r(e) != NULL) {
251 		if (e->ae_number == event_number) {
252 			endauevent();
253 			return (e);
254 		}
255 	}
256 	endauevent();
257 	return ((au_event_ent_t *)NULL);
258 }
259 
260 au_event_ent_t *
261 #ifdef __STDC__
262 getauevnum(au_event_t event_number)
263 #else
264 getauevnum(event_number)
265 	au_event_t event_number;
266 #endif
267 {
268 	static au_event_ent_t e;
269 	static char	ename[AU_EVENT_NAME_MAX];
270 	static char	edesc[AU_EVENT_DESC_MAX];
271 
272 	/* initialize au_event_entry structure */
273 	e.ae_name = ename;
274 	e.ae_desc = edesc;
275 
276 	return (getauevnum_r(&e, event_number));
277 }
278 
279 au_event_t
280 #ifdef __STDC__
281 getauevnonam(char *event_name)
282 #else
283 getauevnonam(event_name)
284 	char	*event_name;
285 #endif
286 {
287 	au_event_ent_t e;
288 	char ename[AU_EVENT_NAME_MAX];
289 	char edesc[AU_EVENT_DESC_MAX];
290 
291 	/* initialize au_event_entry structure */
292 	e.ae_name = ename;
293 	e.ae_desc = edesc;
294 
295 	if (getauevnam_r(&e, event_name) == (au_event_ent_t *)0) {
296 		return (-1);
297 	}
298 	return (e.ae_number);
299 }
300 
301 /*
302  * cacheauevent:
303  *	Read the entire audit_event file into memory.
304  *	Set a pointer to the requested entry in the cache
305  *	or a pointer to an invalid entry if the event number
306  *	is not known.
307  *
308  *	Return < 0, if error.
309  *	Return   0, if event number not in cache.
310  *	Return   1, if event number is in cache.
311  */
312 
313 int
314 #ifdef __STDC__
315 cacheauevent(au_event_ent_t **result, au_event_t event_number)
316 #else
317 cacheauevent(result, event_number)
318 	au_event_ent_t **result; /* set this pointer to an entry in the cache */
319 	au_event_t event_number; /* request this event number */
320 #endif
321 {
322 	static ushort_t	max; /* the highest event number in the file */
323 	static ushort_t	min; /* the lowest event number in the file */
324 	static int	invalid; /* 1+index of the highest event number */
325 	static au_event_ent_t **index_tbl;
326 	static au_event_ent_t **p_tbl;
327 	static int	called_once = 0;
328 
329 	char	line[AU_EVENT_LINE_MAX];
330 	int	lines = 0;
331 	FILE	*fp;
332 	au_event_ent_t *p_event;
333 	int	i, size;
334 	int	hit = 0;
335 	char	*s;
336 
337 	_mutex_lock(&mutex_eventcache);
338 	if (called_once == 0) {
339 
340 		/* Count number of lines in the events file */
341 		if ((fp = fopen(au_event_fname, "rF")) == NULL) {
342 			_mutex_unlock(&mutex_eventcache);
343 			return (-1);
344 		}
345 		while (fgets(line, AU_EVENT_LINE_MAX, fp) != NULL) {
346 			s = line + strspn(line, " \t\r\n");
347 			if ((*s == '\0') || (*s == '#')) {
348 				continue;
349 			}
350 			lines++;
351 		}
352 		(void) fclose(fp);
353 		size = lines;
354 
355 		/*
356 		 * Make an array in which each element in an entry in the
357 		 * events file.  Make the next to last element an invalid
358 		 * event.  Make the last element a NULL pointer.
359 		 */
360 
361 		p_tbl = calloc(lines + 1, sizeof (au_event_ent_t));
362 		if (p_tbl == NULL) {
363 			_mutex_unlock(&mutex_eventcache);
364 			return (-2);
365 		}
366 		lines = 0;
367 		max = 0;
368 		min = 65535;
369 		setauevent();
370 		while ((p_event = getauevent()) != NULL) {
371 			p_tbl[lines] = (au_event_ent_t *)
372 				malloc(sizeof (au_event_ent_t));
373 			if (p_tbl[lines] == NULL) {
374 				_mutex_unlock(&mutex_eventcache);
375 				return (-3);
376 			}
377 			p_tbl[lines]->ae_number = p_event->ae_number;
378 			p_tbl[lines]->ae_name   = strdup(p_event->ae_name);
379 			p_tbl[lines]->ae_desc   = strdup(p_event->ae_desc);
380 			p_tbl[lines]->ae_class  = p_event->ae_class;
381 #ifdef DEBUG2
382 			printevent(p_tbl[lines]);
383 #endif
384 			if ((ushort_t)p_event->ae_number > max) {
385 				max = p_event->ae_number;
386 			}
387 			if ((ushort_t)p_event->ae_number < min) {
388 				min = p_event->ae_number;
389 			}
390 			lines++;
391 		}
392 		endauevent();
393 		invalid = lines;
394 		p_tbl[invalid] = (au_event_ent_t *)
395 			malloc(sizeof (au_event_ent_t));
396 		if (p_tbl[invalid] == NULL) {
397 			_mutex_unlock(&mutex_eventcache);
398 			return (-4);
399 		}
400 		p_tbl[invalid]->ae_number = -1;
401 		p_tbl[invalid]->ae_name   = "invalid event number";
402 		p_tbl[invalid]->ae_desc   = p_tbl[invalid]->ae_name;
403 		p_tbl[invalid]->ae_class  = (au_class_t)-1;
404 
405 #ifdef DEBUG2
406 		for (i = 0; i < size; i++) {
407 			printf("%d:%s:%s:%d\n", p_tbl[i]->ae_number,
408 				p_tbl[i]->ae_name, p_tbl[i]->ae_desc,
409 				p_tbl[i]->ae_class);
410 		}
411 #endif
412 
413 		/* get space for the index_tbl */
414 		index_tbl = calloc(max+1, sizeof (au_event_ent_t *));
415 		if (index_tbl == NULL) {
416 			_mutex_unlock(&mutex_eventcache);
417 			return (-5);
418 		}
419 
420 		/* intialize the index_tbl to the invalid event number */
421 		for (i = 0; (ushort_t)i < max; i++) {
422 			index_tbl[i] = p_tbl[invalid];
423 		}
424 
425 		/* point each index_tbl element at the corresponding event */
426 		for (i = 0; i < size; i++) {
427 			index_tbl[(ushort_t)p_tbl[i]->ae_number] = p_tbl[i];
428 		}
429 
430 		called_once = 1;
431 
432 	}
433 
434 	if ((ushort_t)event_number > max || (ushort_t)event_number < min) {
435 		*result = index_tbl[invalid];
436 	} else {
437 		*result = index_tbl[(ushort_t)event_number];
438 		hit = 1;
439 	}
440 	_mutex_unlock(&mutex_eventcache);
441 	return (hit);
442 }
443 
444 
445 static au_class_t
446 flagstohex(char *flags)
447 {
448 	au_class_ent_t *p_class;
449 	au_class_t	hex = 0;
450 	char	*comma = ",";
451 	char	*s;
452 	char	*last;
453 
454 	s = strtok_r(flags, comma, &last);
455 	while (s != NULL) {
456 		if ((cacheauclassnam(&p_class, s)) < 0) {
457 			cacheauclass_failure = 1;
458 			return ((au_class_t)-1);
459 		}
460 		hex |= p_class->ac_class;
461 		s = strtok_r(NULL, comma, &last);
462 	}
463 	return (hex);
464 }
465 
466 
467 #ifdef DEBUG2
468 void
469 printevent(p_event)
470 au_event_ent_t *p_event;
471 {
472 	printf("%d:%s:%s:%d\n", p_event->ae_number, p_event->ae_name,
473 		p_event->ae_desc, p_event->ae_class);
474 	fflush(stdout);
475 }
476 
477 
478 #endif
479