source: trunk/src/sh_fInotify.c@ 427

Last change on this file since 427 was 426, checked in by katerina, 12 years ago

Fix for ticket #333 (spurious error message)
File size: 18.1 KB
Line 
1/* SAMHAIN file system integrity testing */
2/* Copyright (C) 2011 Rainer Wichmann */
3/* */
4/* This program is free software; you can redistribute it */
5/* and/or modify */
6/* it under the terms of the GNU General Public License as */
7/* published by */
8/* the Free Software Foundation; either version 2 of the License, or */
9/* (at your option) any later version. */
10/* */
11/* This program is distributed in the hope that it will be useful, */
12/* but WITHOUT ANY WARRANTY; without even the implied warranty of */
13/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the */
14/* GNU General Public License for more details. */
15/* */
16/* You should have received a copy of the GNU General Public License */
17/* along with this program; if not, write to the Free Software */
18/* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
19
20/***************************************************************************
21 *
22 * This file provides a module for samhain to use inotify for file checking.
23 *
24 */
25
26#include "config_xor.h"
27
28#if (defined(SH_WITH_CLIENT) || defined(SH_STANDALONE))
29
30#include "samhain.h"
31#include "sh_utils.h"
32#include "sh_modules.h"
33#include "sh_pthread.h"
34#include "sh_inotify.h"
35#include "sh_unix.h"
36#include "sh_hash.h"
37#include "sh_files.h"
38#include "sh_ignore.h"
39
40#define FIL__ _("sh_fInotify.c")
41
42sh_watches sh_file_watches = SH_INOTIFY_INITIALIZER;
43
44#if defined(HAVE_SYS_INOTIFY_H)
45
46static sh_watches sh_file_missing = SH_INOTIFY_INITIALIZER;
47
48#include <sys/inotify.h>
49
50/* --- Configuration ------- */
51
52static int ShfInotifyActive = S_FALSE;
53
54static unsigned long ShfInotifyWatches = 0;
55
56static int sh_fInotify_active(const char *s)
57{
58 int value;
59
60 SL_ENTER(_("sh_fInotify_active"));
61 value = sh_util_flagval(s, &ShfInotifyActive);
62 if (value == 0 && ShfInotifyActive != S_FALSE)
63 {
64 sh.flag.inotify |= SH_INOTIFY_USE;
65 sh.flag.inotify |= SH_INOTIFY_DOSCAN;
66 sh.flag.inotify |= SH_INOTIFY_NEEDINIT;
67 }
68 if (value == 0 && ShfInotifyActive == S_FALSE)
69 {
70 sh.flag.inotify = 0;
71 }
72 SL_RETURN((value), _("sh_fInotify_active"));
73}
74
75static int sh_fInotify_watches(const char *s)
76{
77 int retval = -1;
78 char * foo;
79 unsigned long value;
80
81 SL_ENTER(_("sh_fInotify_watches"));
82
83 value = strtoul(s, &foo, 0);
84 if (*foo == '\0')
85 {
86 ShfInotifyWatches = (value > 2147483647) ? 2147483647 /* MAX_INT_32 */: value;
87 retval = 0;
88 }
89 SL_RETURN((retval), _("sh_fInotify_watches"));
90}
91
92
93sh_rconf sh_fInotify_table[] = {
94 {
95 N_("inotifyactive"),
96 sh_fInotify_active,
97 },
98 {
99 N_("inotifywatches"),
100 sh_fInotify_watches,
101 },
102 {
103 NULL,
104 NULL
105 }
106};
107
108/* --- End Configuration --- */
109
110static int sh_fInotify_init_internal(void);
111static int sh_fInotify_process(struct inotify_event * event);
112static int sh_fInotify_report(struct inotify_event * event, char * filename,
113 int class, unsigned long check_mask, int ftype, int rdepth);
114
115int sh_fInotify_init(struct mod_type * arg)
116{
117#ifndef HAVE_PTHREAD
118 (void) arg;
119 return SH_MOD_FAILED;
120#else
121
122 if (ShfInotifyActive == S_FALSE)
123 return SH_MOD_FAILED;
124
125 if (sh.flag.checkSum == SH_CHECK_INIT)
126 return SH_MOD_FAILED;
127
128 if (arg != NULL && arg->initval < 0 &&
129 (sh.flag.isdaemon == S_TRUE || sh.flag.loop == S_TRUE))
130 {
131 /* Init from main thread */
132 sh.flag.inotify |= SH_INOTIFY_DOSCAN;
133 sh.flag.inotify |= SH_INOTIFY_NEEDINIT;
134
135 if (0 == sh_pthread_create(sh_threaded_module_run, (void *)arg))
136 {
137 return SH_MOD_THREAD;
138 }
139 else
140 {
141 sh.flag.inotify = 0;
142 return SH_MOD_FAILED;
143 }
144 }
145 else if (arg != NULL && arg->initval < 0 &&
146 (sh.flag.isdaemon != S_TRUE && sh.flag.loop != S_TRUE))
147 {
148 sh.flag.inotify = 0;
149 return SH_MOD_FAILED;
150 }
151 else if (arg != NULL && arg->initval == SH_MOD_THREAD &&
152 (sh.flag.isdaemon == S_TRUE || sh.flag.loop == S_TRUE))
153 {
154 /* Reconfigure from main thread */
155 /* sh_fInotify_init_internal(); */
156 sh.flag.inotify |= SH_INOTIFY_DOSCAN;
157 sh.flag.inotify |= SH_INOTIFY_NEEDINIT;
158 return SH_MOD_THREAD;
159 }
160
161 /* Within thread, init */
162 return sh_fInotify_init_internal();
163#endif
164}
165
166int sh_fInotify_run()
167{
168 ssize_t len = -1;
169 char * buffer;
170 static int count = 0;
171 static int count2 = 0;
172
173 if (ShfInotifyActive == S_FALSE)
174 {
175 return SH_MOD_FAILED;
176 }
177
178 if ( (sh.flag.inotify & SH_INOTIFY_DOSCAN) ||
179 (sh.flag.inotify & SH_INOTIFY_NEEDINIT))
180 {
181 if (0 != sh_fInotify_init_internal())
182 {
183 return SH_MOD_FAILED;
184 }
185 }
186
187 buffer = SH_ALLOC(16384);
188
189 /* Blocking read from inotify file descriptor.
190 */
191 len = sh_inotify_read_timeout(buffer, 16384, 1);
192
193 if (len > 0)
194 {
195 struct inotify_event *event;
196 int i = 0;
197
198 while (i < len)
199 {
200 event = (struct inotify_event *) &(buffer[i]);
201
202 sh_fInotify_process(event);
203
204 i += sizeof (struct inotify_event) + event->len;
205 }
206
207 if ( (sh.flag.inotify & SH_INOTIFY_DOSCAN) ||
208 (sh.flag.inotify & SH_INOTIFY_NEEDINIT))
209 {
210 if (0 != sh_fInotify_init_internal())
211 {
212 SH_FREE(buffer);
213 return SH_MOD_FAILED;
214 }
215 }
216 }
217
218 /* Re-scan 'dormant' list of sh_file_missing.
219 */
220 sh_inotify_recheck_watches (&sh_file_watches, &sh_file_missing);
221
222 ++count;
223 ++count2;
224
225 if (count >= 10)
226 {
227 count = 0; /* Re-expand glob patterns to discover added files. */
228 sh.flag.inotify |= SH_INOTIFY_INSCAN;
229 sh_files_check_globFilePatterns();
230 sh.flag.inotify &= ~SH_INOTIFY_INSCAN;
231 sh.flag.inotify |= SH_INOTIFY_NEEDINIT;
232 }
233
234 if (count2 >= 300)
235 {
236 count2 = 0; /* Update baseline database. */
237 if (sh.flag.checkSum == SH_CHECK_CHECK && sh.flag.update == S_TRUE)
238 sh_hash_writeout ();
239 }
240
241 SH_FREE(buffer);
242 return 0;
243}
244
245/* We block in the read() call on the inotify descriptor,
246 * so we always run.
247 */
248int sh_fInotify_timer(time_t tcurrent)
249{
250 (void) tcurrent;
251 return 1;
252}
253
254int sh_fInotify_cleanup()
255{
256 sh_inotify_purge_dormant(&sh_file_watches);
257 sh_inotify_remove(&sh_file_watches);
258 sh_inotify_init(&sh_file_watches);
259 return 0;
260}
261
262int sh_fInotify_reconf()
263{
264 sh.flag.inotify = 0;
265
266 ShfInotifyWatches = 0;
267 ShfInotifyActive = 0;
268
269 return sh_fInotify_cleanup();
270}
271
272#define PROC_WATCHES_MAX _("/proc/sys/fs/inotify/max_user_watches")
273
274static void sh_fInotify_set_nwatches()
275{
276 static int fails = 0;
277
278 if (ShfInotifyWatches == 0 || fails == 1)
279 return;
280
281 if (0 == access(PROC_WATCHES_MAX, R_OK|W_OK)) /* flawfinder: ignore */
282 {
283 FILE * fd;
284
285 if (NULL != (fd = fopen(PROC_WATCHES_MAX, "r+")))
286 {
287 char str[128];
288 char * ret;
289 char * ptr;
290 unsigned long wn;
291
292 str[0] = '\0';
293 ret = fgets(str, 128, fd);
294 if (ret && *str != '\0')
295 {
296 wn = strtoul(str, &ptr, 0);
297 if (*ptr == '\0' || *ptr == '\n')
298 {
299 if (wn < ShfInotifyWatches)
300 {
301 sl_snprintf(str, sizeof(str), "%lu\n", ShfInotifyWatches);
302 (void) fseek(fd, 0L, SEEK_SET);
303 fputs(str, fd);
304 }
305 sl_fclose(FIL__, __LINE__, fd);
306 return;
307 }
308 }
309 sl_fclose(FIL__, __LINE__, fd);
310 }
311 }
312 SH_MUTEX_LOCK(mutex_thread_nolog);
313 sh_error_handle((-1), FIL__, __LINE__, 0, MSG_E_SUBGEN,
314 _("Cannot set max_user_watches"),
315 _("sh_fInotify_set_nwatches"));
316 SH_MUTEX_UNLOCK(mutex_thread_nolog);
317 fails = 1;
318 return;
319}
320
321/* The watch fd is thread specific. To have it in the fInotify thread,
322 * the main thread writes a list of files/dirs to watch, and here we
323 * now pop files from the list to add watches for them.
324 */
325static int sh_fInotify_init_internal()
326{
327 char * filename;
328 int class;
329 int type;
330 int rdepth;
331 unsigned long check_mask;
332 int retval;
333 int errnum;
334
335 if (ShfInotifyActive == S_FALSE)
336 return SH_MOD_FAILED;
337
338 /* Wait until file scan is finished.
339 */
340 while((sh.flag.inotify & SH_INOTIFY_DOSCAN) != 0)
341 {
342 retry_msleep(1,0);
343
344 if (ShfInotifyActive == S_FALSE)
345 return SH_MOD_FAILED;
346 }
347
348 sh_fInotify_set_nwatches();
349
350 while (NULL != (filename = sh_inotify_pop_dormant(&sh_file_watches,
351 &class, &check_mask,
352 &type, &rdepth)))
353 {
354 retval = sh_inotify_add_watch(filename, &sh_file_watches, &errnum,
355 class, check_mask, type, rdepth);
356
357 if (retval < 0)
358 {
359 char errbuf[SH_ERRBUF_SIZE];
360
361 sh_error_message(errnum, errbuf, sizeof(errbuf));
362
363 if ((errnum == ENOENT) || (errnum == EEXIST))
364 {
365 /* (1) Did it exist at init ?
366 */
367 if (sh_hash_have_it (filename) >= 0)
368 {
369 /* (2) Do we want to report on it ?
370 */
371 if (S_FALSE == sh_ignore_chk_del(filename))
372 {
373 char * epath = sh_util_safe_name (filename);
374
375 SH_MUTEX_LOCK(mutex_thread_nolog);
376 sh_error_handle( SH_ERR_ALL /* debug */,
377 FIL__, __LINE__, errnum, MSG_E_SUBGPATH,
378 errbuf, _("sh_fInotify_init_internal"), epath);
379 SH_MUTEX_UNLOCK(mutex_thread_nolog);
380 SH_FREE(epath);
381 }
382 }
383 }
384 else
385 {
386 SH_MUTEX_LOCK(mutex_thread_nolog);
387 sh_error_handle((-1), FIL__, __LINE__, errnum, MSG_E_SUBGEN,
388 errbuf, _("sh_fInotify_init_internal"));
389 SH_MUTEX_UNLOCK(mutex_thread_nolog);
390 }
391 }
392 SH_FREE(filename);
393 }
394
395 /* Need this because mod_check() may run after
396 * DOSCAN is finished, hence wouldn't call init().
397 */
398 sh.flag.inotify &= ~SH_INOTIFY_NEEDINIT;
399
400 return 0;
401}
402
403static void sh_fInotify_logmask(struct inotify_event * event)
404{
405 char dbgbuf[256];
406
407 sl_strlcpy (dbgbuf, "inotify mask: ", sizeof(dbgbuf));
408
409 if (event->mask & IN_ACCESS) sl_strlcat(dbgbuf, "IN_ACCESS ", sizeof(dbgbuf));
410 if (event->mask & IN_ATTRIB) sl_strlcat(dbgbuf, "IN_ATTRIB ", sizeof(dbgbuf));
411 if (event->mask & IN_CLOSE_WRITE) sl_strlcat(dbgbuf, "IN_CLOSE_WRITE ", sizeof(dbgbuf));
412 if (event->mask & IN_CLOSE_NOWRITE) sl_strlcat(dbgbuf, "IN_CLOSE_NOWRITE ", sizeof(dbgbuf));
413 if (event->mask & IN_CREATE) sl_strlcat(dbgbuf, "IN_CREATE ", sizeof(dbgbuf));
414 if (event->mask & IN_DELETE) sl_strlcat(dbgbuf, "IN_DELETE ", sizeof(dbgbuf));
415 if (event->mask & IN_DELETE_SELF) sl_strlcat(dbgbuf, "IN_DELETE_SELF ", sizeof(dbgbuf));
416 if (event->mask & IN_MODIFY) sl_strlcat(dbgbuf, "IN_MODIFY ", sizeof(dbgbuf));
417 if (event->mask & IN_MOVE_SELF) sl_strlcat(dbgbuf, "IN_MOVE_SELF ", sizeof(dbgbuf));
418 if (event->mask & IN_MOVED_FROM) sl_strlcat(dbgbuf, "IN_MOVED_FROM ", sizeof(dbgbuf));
419 if (event->mask & IN_MOVED_TO) sl_strlcat(dbgbuf, "IN_MOVED_TO ", sizeof(dbgbuf));
420 if (event->mask & IN_OPEN) sl_strlcat(dbgbuf, "IN_OPEN ", sizeof(dbgbuf));
421 if (event->mask & IN_IGNORED) sl_strlcat(dbgbuf, "IN_IGNORED ", sizeof(dbgbuf));
422 if (event->mask & IN_ISDIR) sl_strlcat(dbgbuf, "IN_ISDIR ", sizeof(dbgbuf));
423 if (event->mask & IN_Q_OVERFLOW) sl_strlcat(dbgbuf, "IN_Q_OVERFLOW ", sizeof(dbgbuf));
424 if (event->mask & IN_UNMOUNT) sl_strlcat(dbgbuf, "IN_UNMOUNT ", sizeof(dbgbuf));
425
426 /* fprintf(stderr, "FIXME: %s\n", dbgbuf); */
427
428 SH_MUTEX_LOCK(mutex_thread_nolog);
429 sh_error_handle(SH_ERR_ALL, FIL__, __LINE__, 0, MSG_E_SUBGEN,
430 dbgbuf, _("sh_fInotify_process"));
431 SH_MUTEX_UNLOCK(mutex_thread_nolog);
432}
433
434static int sh_fInotify_process(struct inotify_event * event)
435{
436 int class;
437 int ftype;
438 int rdepth;
439 unsigned long check_mask;
440 char * filename;
441 extern int flag_err_debug;
442
443 if (flag_err_debug == SL_TRUE)
444 {
445 sh_fInotify_logmask(event);
446 }
447
448 if (event->wd >= 0)
449 {
450 filename = sh_inotify_search_item(&sh_file_watches, event->wd,
451 &class, &check_mask, &ftype, &rdepth);
452
453 if (filename)
454 {
455 sh_fInotify_report(event, filename, class, check_mask, ftype, rdepth);
456 SH_FREE(filename);
457 }
458 else if (sh.flag.inotify & SH_INOTIFY_NEEDINIT)
459 {
460 return 1;
461 }
462 else if ((event->mask & IN_UNMOUNT) == 0 && (event->mask & IN_IGNORED) == 0)
463 {
464 /* Remove watch ? Seems reasonable. */
465 sh_inotify_rm_watch(NULL, NULL, event->wd);
466
467 SH_MUTEX_LOCK(mutex_thread_nolog);
468 sh_error_handle(SH_ERR_ALL, FIL__, __LINE__, event->wd, MSG_E_SUBGEN,
469 _("Watch removed: file path unknown"),
470 _("sh_fInotify_process"));
471 SH_MUTEX_UNLOCK(mutex_thread_nolog);
472 }
473 }
474 else if ((event->mask & IN_Q_OVERFLOW) != 0)
475 {
476 sh.flag.inotify |= SH_INOTIFY_DOSCAN;
477 sh.flag.inotify |= SH_INOTIFY_NEEDINIT;
478 SH_MUTEX_LOCK(mutex_thread_nolog);
479 sh_error_handle(SH_ERR_WARN, FIL__, __LINE__, event->wd, MSG_E_SUBGEN,
480 _("Inotify queue overflow"),
481 _("sh_fInotify_process"));
482 SH_MUTEX_UNLOCK(mutex_thread_nolog);
483 return 1;
484 }
485
486 return 0;
487}
488
489void sh_fInotify_report_add(char * path, int class, unsigned long check_mask)
490{
491 if (S_FALSE == sh_ignore_chk_new(path))
492 {
493 int reported = 0;
494
495 sh_files_clear_file_reported(path);
496
497 sh_files_search_file(path, &class, &check_mask, &reported);
498
499 sh_files_filecheck (class, check_mask, path, NULL,
500 &reported, 0);
501 if (SH_FFLAG_REPORTED_SET(reported))
502 sh_files_set_file_reported(path);
503 }
504 return;
505}
506
507
508static void sh_fInotify_report_miss(char * name, int level)
509{
510 char * tmp = sh_util_safe_name (name);
511
512 SH_MUTEX_LOCK(mutex_thread_nolog);
513 sh_error_handle (level, FIL__, __LINE__, 0, MSG_FI_MISS, tmp);
514 SH_MUTEX_UNLOCK(mutex_thread_nolog);
515 ++sh.statistics.files_report;
516 SH_FREE(tmp);
517 return;
518}
519
520static int sh_fInotify_report_change (struct inotify_event * event,
521 char * path, char * filename,
522 int class, unsigned long check_mask, int ftype)
523{
524 int reported;
525 int ret;
526
527
528 if (S_FALSE == sh_ignore_chk_mod(path))
529 {
530 ret = sh_files_search_file(path, &class, &check_mask, &reported);
531
532 if ((ret == 0) && (event->len > 0) && (ftype == SH_INOTIFY_FILE))
533 {
534 ; /* do nothing, watch was for directory monitored as file only */
535 }
536 else
537 {
538 sh_files_filecheck (class, check_mask, filename,
539 (event->len > 0) ? event->name : NULL,
540 &reported, 0);
541 }
542 }
543 return 0;
544}
545
546
547static int sh_fInotify_report_missing (struct inotify_event * event,
548 char * path,
549 int class, unsigned long check_mask, int ftype)
550{
551 int reported;
552 int isdir = (event->mask & IN_ISDIR);
553 int level = (class == SH_LEVEL_ALLIGNORE) ?
554 ShDFLevel[class] :
555 ShDFLevel[(isdir == 0) ? SH_ERR_T_FILE : SH_ERR_T_DIR];
556
557 if (S_FALSE == sh_ignore_chk_del(path))
558 {
559 if (0 != hashreport_missing(path, level))
560 {
561 int ret = sh_files_search_file(path, &class, &check_mask, &reported);
562
563 if ((ret == 0) && (event->len > 0) && (ftype == SH_INOTIFY_FILE))
564 {
565 ; /* do nothing, watch was for directory monitored as file only */
566 }
567 else
568 {
569 /* Removal of a directory triggers:
570 * (1) IN_DELETE IN_ISDIR
571 * (2) IN_DELETE_SELF
572 */
573 if ((event->mask & IN_DELETE_SELF) == 0)
574 sh_fInotify_report_miss(path, level);
575 }
576 }
577 }
578
579#ifndef REPLACE_OLD
580 sh_hash_set_visited_true(path);
581#else
582 sh_hash_set_missing(path);
583#endif
584 if (sh.flag.reportonce == S_TRUE)
585 sh_files_set_file_reported(path);
586
587 /* Move to 'dormant' list, if not file within directory.
588 */
589 if (event->len == 0)
590 sh_inotify_rm_watch(&sh_file_watches, &sh_file_missing, event->wd);
591
592 return 0;
593}
594
595static int sh_fInotify_report_added (struct inotify_event * event,
596 char * path, char * filename,
597 int class, unsigned long check_mask,
598 int ftype, int rdepth)
599{
600 if (S_FALSE == sh_ignore_chk_new(path))
601 {
602 int reported;
603 int ret;
604 int retD = 0;
605 int rdepthD = rdepth;
606
607 sh_files_clear_file_reported(path);
608
609 ret = sh_files_search_file(path, &class, &check_mask, &reported);
610
611 if ((ret == 0) && (event->len > 0) && (ftype == SH_INOTIFY_FILE))
612 {
613 ; /* do nothing, watch was for directory monitored as file only */
614 }
615 else
616 {
617 int classD = class;
618 int reportedD = reported;
619 unsigned long check_maskD = check_mask;
620
621 if (event->mask & IN_ISDIR)
622 {
623 retD = sh_files_search_dir(path, &classD, &check_maskD,
624 &reportedD, &rdepthD);
625 if (retD != 0)
626 {
627 if (ret == 0)
628 {
629 class = classD;
630 check_mask = check_maskD;
631 }
632 }
633 }
634
635 sh_files_filecheck (class, check_mask, filename,
636 (event->len > 0) ? event->name : NULL,
637 &reported, 0);
638
639 if (event->mask & IN_ISDIR)
640 {
641 sh.flag.inotify |= SH_INOTIFY_INSCAN;
642 sh_files_checkdir (classD, check_maskD, rdepthD,
643 path, (event->len > 0) ? event->name : NULL);
644 sh.flag.inotify &= ~SH_INOTIFY_INSCAN;
645 sh.flag.inotify |= SH_INOTIFY_NEEDINIT;
646 sh_dirs_reset ();
647 sh_files_reset ();
648 }
649
650 }
651
652 if (SH_FFLAG_REPORTED_SET(reported))
653 sh_files_set_file_reported(path);
654
655 if ((ret != 0) || (event->mask & IN_ISDIR))
656 {
657 sh_inotify_add_watch(path, &sh_file_watches, &ret,
658 class, check_mask,
659 (event->mask & IN_ISDIR)?SH_INOTIFY_DIR:SH_INOTIFY_FILE,
660 rdepthD);
661 }
662 }
663 return 0;
664}
665
666static int sh_fInotify_report(struct inotify_event * event, char * filename,
667 int class, unsigned long check_mask, int ftype, int rdepth)
668{
669 char * fullpath = NULL;
670 char * path;
671
672 if (event->len > 0)
673 {
674 fullpath = sh_util_strconcat(filename, "/", event->name, NULL);
675 path = fullpath;
676 }
677 else
678 {
679 path = filename;
680 }
681
682 if ( (event->mask & (IN_ATTRIB|IN_MODIFY)) != 0)
683 {
684 sh_fInotify_report_change (event, path, filename,
685 class, check_mask, ftype);
686 }
687 else if ((event->mask & (IN_DELETE|IN_DELETE_SELF|IN_MOVE_SELF|IN_MOVED_FROM)) != 0)
688 {
689 sh_fInotify_report_missing (event, path,
690 class, check_mask, ftype);
691 }
692 else if((event->mask & (IN_CREATE|IN_MOVED_TO)) != 0)
693 {
694 sh_fInotify_report_added (event, path, filename,
695 class, check_mask,
696 ftype, rdepth);
697 }
698
699 if (fullpath)
700 SH_FREE(fullpath);
701
702 return 0;
703}
704
705
706#endif
707
708#endif
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