1/*
2 * Copyright (c) 1999-2005 Apple Computer, Inc.
3 * Copyright (c) 2005 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 * $FreeBSD: head/sys/security/audit/audit_bsm_klib.c 159143 2006-06-01 15:38:30Z csjp $
|
| 30 * $FreeBSD: head/sys/security/audit/audit_bsm_klib.c 159269 2006-06-05 14:48:17Z rwatson $ |
31 */
32
33#include <sys/param.h>
34#include <sys/fcntl.h>
35#include <sys/filedesc.h>
36#include <sys/libkern.h>
37#include <sys/malloc.h>
38#include <sys/mount.h>
39#include <sys/proc.h>
40#include <sys/sem.h>
41#include <sys/syscall.h>
42#include <sys/sysctl.h>
43#include <sys/sysent.h>
44#include <sys/vnode.h>
45
46#include <bsm/audit.h>
47#include <bsm/audit_kevents.h>
48#include <security/audit/audit.h>
49#include <security/audit/audit_private.h>
50
51/*
52 * Hash table functions for the audit event number to event class mask
53 * mapping.
54 */
55#define EVCLASSMAP_HASH_TABLE_SIZE 251
56struct evclass_elem {
57 au_event_t event;
58 au_class_t class;
59 LIST_ENTRY(evclass_elem) entry;
60};
61struct evclass_list {
62 LIST_HEAD(, evclass_elem) head;
63};
64
65static MALLOC_DEFINE(M_AUDITEVCLASS, "audit_evclass", "Audit event class");
66static struct mtx evclass_mtx;
67static struct evclass_list evclass_hash[EVCLASSMAP_HASH_TABLE_SIZE];
68
69/*
70 * Look up the class for an audit event in the class mapping table.
71 */
72au_class_t
73au_event_class(au_event_t event)
74{
75 struct evclass_list *evcl;
76 struct evclass_elem *evc;
77 au_class_t class;
78
79 mtx_lock(&evclass_mtx);
80 evcl = &evclass_hash[event % EVCLASSMAP_HASH_TABLE_SIZE];
81 class = AU_NULL;
82 LIST_FOREACH(evc, &evcl->head, entry) {
83 if (evc->event == event) {
84 class = evc->class;
85 goto out;
86 }
87 }
88out:
89 mtx_unlock(&evclass_mtx);
90 return (class);
91}
92
93/*
94 * Insert a event to class mapping. If the event already exists in the
95 * mapping, then replace the mapping with the new one.
96 *
97 * XXX There is currently no constraints placed on the number of mappings.
98 * May want to either limit to a number, or in terms of memory usage.
99 */
100void
101au_evclassmap_insert(au_event_t event, au_class_t class)
102{
103 struct evclass_list *evcl;
104 struct evclass_elem *evc, *evc_new;
105
106 /*
107 * Pessimistically, always allocate storage before acquiring mutex.
108 * Free if there is already a mapping for this event.
109 */
110 evc_new = malloc(sizeof(*evc), M_AUDITEVCLASS, M_WAITOK);
111
112 mtx_lock(&evclass_mtx);
113 evcl = &evclass_hash[event % EVCLASSMAP_HASH_TABLE_SIZE];
114 LIST_FOREACH(evc, &evcl->head, entry) {
115 if (evc->event == event) {
116 evc->class = class;
117 mtx_unlock(&evclass_mtx);
118 free(evc_new, M_AUDITEVCLASS);
119 return;
120 }
121 }
122 evc = evc_new;
123 evc->event = event;
124 evc->class = class;
125 LIST_INSERT_HEAD(&evcl->head, evc, entry);
126 mtx_unlock(&evclass_mtx);
127}
128
129void
130au_evclassmap_init(void)
131{
132 int i;
133
134 mtx_init(&evclass_mtx, "evclass_mtx", NULL, MTX_DEF);
135 for (i = 0; i < EVCLASSMAP_HASH_TABLE_SIZE; i++)
136 LIST_INIT(&evclass_hash[i].head);
137
138 /*
139 * Set up the initial event to class mapping for system calls.
140 *
141 * XXXRW: Really, this should walk all possible audit events, not all
142 * native ABI system calls, as there may be audit events reachable
143 * only through non-native system calls. It also seems a shame to
144 * frob the mutex this early.
145 */
146 for (i = 0; i < SYS_MAXSYSCALL; i++) {
147 if (sysent[i].sy_auevent != AUE_NULL)
148 au_evclassmap_insert(sysent[i].sy_auevent, AU_NULL);
149 }
150}
151
152/*
153 * Check whether an event is aditable by comparing the mask of classes this
154 * event is part of against the given mask.
155 */
156int
|
157au_preselect(au_event_t event, au_mask_t *mask_p, int sorf)
|
| 157au_preselect(au_event_t event, au_class_t class, au_mask_t *mask_p, int sorf) |
158{
159 au_class_t effmask = 0;
|
160 au_class_t ae_class;
|
160
161 if (mask_p == NULL)
162 return (-1);
163
|
165 ae_class = au_event_class(event);
166
|
164 /*
165 * Perform the actual check of the masks against the event.
166 */
167 if (sorf & AU_PRS_SUCCESS)
|
171 effmask |= (mask_p->am_success & ae_class);
|
| 168 effmask |= (mask_p->am_success & class); |
169
170 if (sorf & AU_PRS_FAILURE)
|
174 effmask |= (mask_p->am_failure & ae_class);
|
| 171 effmask |= (mask_p->am_failure & class); |
172
173 if (effmask)
174 return (1);
175 else
176 return (0);
177}
178
179/*
180 * Convert sysctl names and present arguments to events.
181 */
182au_event_t
183ctlname_to_sysctlevent(int name[], uint64_t valid_arg)
184{
185
186 /* can't parse it - so return the worst case */
187 if ((valid_arg & (ARG_CTLNAME | ARG_LEN)) != (ARG_CTLNAME | ARG_LEN))
188 return (AUE_SYSCTL);
189
190 switch (name[0]) {
191 /* non-admin "lookups" treat them special */
192 case KERN_OSTYPE:
193 case KERN_OSRELEASE:
194 case KERN_OSREV:
195 case KERN_VERSION:
196 case KERN_ARGMAX:
197 case KERN_CLOCKRATE:
198 case KERN_BOOTTIME:
199 case KERN_POSIX1:
200 case KERN_NGROUPS:
201 case KERN_JOB_CONTROL:
202 case KERN_SAVED_IDS:
203 case KERN_OSRELDATE:
204 case KERN_DUMMY:
205 return (AUE_SYSCTL_NONADMIN);
206
207 /* only treat the changeable controls as admin */
208 case KERN_MAXVNODES:
209 case KERN_MAXPROC:
210 case KERN_MAXFILES:
211 case KERN_MAXPROCPERUID:
212 case KERN_MAXFILESPERPROC:
213 case KERN_HOSTID:
214 case KERN_SECURELVL:
215 case KERN_HOSTNAME:
216 case KERN_VNODE:
217 case KERN_PROC:
218 case KERN_FILE:
219 case KERN_PROF:
220 case KERN_NISDOMAINNAME:
221 case KERN_UPDATEINTERVAL:
222 case KERN_NTP_PLL:
223 case KERN_BOOTFILE:
224 case KERN_DUMPDEV:
225 case KERN_IPC:
226 case KERN_PS_STRINGS:
227 case KERN_USRSTACK:
228 case KERN_LOGSIGEXIT:
229 case KERN_IOV_MAX:
230 case KERN_MAXID:
231 return ((valid_arg & ARG_VALUE) ?
232 AUE_SYSCTL : AUE_SYSCTL_NONADMIN);
233
234 default:
235 return (AUE_SYSCTL);
236 }
237 /* NOTREACHED */
238}
239
240/*
241 * Convert an open flags specifier into a specific type of open event for
242 * auditing purposes.
243 */
244au_event_t
245flags_and_error_to_openevent(int oflags, int error)
246{
247 au_event_t aevent;
248
249 /*
250 * Need to check only those flags we care about.
251 */
252 oflags = oflags & (O_RDONLY | O_CREAT | O_TRUNC | O_RDWR | O_WRONLY);
253
254 /*
255 * These checks determine what flags are on with the condition that
256 * ONLY that combination is on, and no other flags are on.
257 */
258 switch (oflags) {
259 case O_RDONLY:
260 aevent = AUE_OPEN_R;
261 break;
262
263 case (O_RDONLY | O_CREAT):
264 aevent = AUE_OPEN_RC;
265 break;
266
267 case (O_RDONLY | O_CREAT | O_TRUNC):
268 aevent = AUE_OPEN_RTC;
269 break;
270
271 case (O_RDONLY | O_TRUNC):
272 aevent = AUE_OPEN_RT;
273 break;
274
275 case O_RDWR:
276 aevent = AUE_OPEN_RW;
277 break;
278
279 case (O_RDWR | O_CREAT):
280 aevent = AUE_OPEN_RWC;
281 break;
282
283 case (O_RDWR | O_CREAT | O_TRUNC):
284 aevent = AUE_OPEN_RWTC;
285 break;
286
287 case (O_RDWR | O_TRUNC):
288 aevent = AUE_OPEN_RWT;
289 break;
290
291 case O_WRONLY:
292 aevent = AUE_OPEN_W;
293 break;
294
295 case (O_WRONLY | O_CREAT):
296 aevent = AUE_OPEN_WC;
297 break;
298
299 case (O_WRONLY | O_CREAT | O_TRUNC):
300 aevent = AUE_OPEN_WTC;
301 break;
302
303 case (O_WRONLY | O_TRUNC):
304 aevent = AUE_OPEN_WT;
305 break;
306
307 default:
308 aevent = AUE_OPEN;
309 break;
310 }
311
312#if 0
313 /*
314 * Convert chatty errors to better matching events.
315 * Failures to find a file are really just attribute
316 * events - so recast them as such.
317 *
318 * XXXAUDIT: Solaris defines that AUE_OPEN will never be returned, it
319 * is just a placeholder. However, in Darwin we return that in
320 * preference to other events. For now, comment this out as we don't
321 * have a BSM conversion routine for AUE_OPEN.
322 */
323 switch (aevent) {
324 case AUE_OPEN_R:
325 case AUE_OPEN_RT:
326 case AUE_OPEN_RW:
327 case AUE_OPEN_RWT:
328 case AUE_OPEN_W:
329 case AUE_OPEN_WT:
330 if (error == ENOENT)
331 aevent = AUE_OPEN;
332 }
333#endif
334 return (aevent);
335}
336
337/*
338 * Convert a MSGCTL command to a specific event.
339 */
340int
341msgctl_to_event(int cmd)
342{
343
344 switch (cmd) {
345 case IPC_RMID:
346 return (AUE_MSGCTL_RMID);
347
348 case IPC_SET:
349 return (AUE_MSGCTL_SET);
350
351 case IPC_STAT:
352 return (AUE_MSGCTL_STAT);
353
354 default:
355 /* We will audit a bad command */
356 return (AUE_MSGCTL);
357 }
358}
359
360/*
361 * Convert a SEMCTL command to a specific event.
362 */
363int
364semctl_to_event(int cmd)
365{
366
367 switch (cmd) {
368 case GETALL:
369 return (AUE_SEMCTL_GETALL);
370
371 case GETNCNT:
372 return (AUE_SEMCTL_GETNCNT);
373
374 case GETPID:
375 return (AUE_SEMCTL_GETPID);
376
377 case GETVAL:
378 return (AUE_SEMCTL_GETVAL);
379
380 case GETZCNT:
381 return (AUE_SEMCTL_GETZCNT);
382
383 case IPC_RMID:
384 return (AUE_SEMCTL_RMID);
385
386 case IPC_SET:
387 return (AUE_SEMCTL_SET);
388
389 case SETALL:
390 return (AUE_SEMCTL_SETALL);
391
392 case SETVAL:
393 return (AUE_SEMCTL_SETVAL);
394
395 case IPC_STAT:
396 return (AUE_SEMCTL_STAT);
397
398 default:
399 /* We will audit a bad command */
400 return (AUE_SEMCTL);
401 }
402}
403
404/*
405 * Convert a command for the auditon() system call to a audit event.
406 */
407int
408auditon_command_event(int cmd)
409{
410
411 switch(cmd) {
412 case A_GETPOLICY:
413 return (AUE_AUDITON_GPOLICY);
414
415 case A_SETPOLICY:
416 return (AUE_AUDITON_SPOLICY);
417
418 case A_GETKMASK:
419 return (AUE_AUDITON_GETKMASK);
420
421 case A_SETKMASK:
422 return (AUE_AUDITON_SETKMASK);
423
424 case A_GETQCTRL:
425 return (AUE_AUDITON_GQCTRL);
426
427 case A_SETQCTRL:
428 return (AUE_AUDITON_SQCTRL);
429
430 case A_GETCWD:
431 return (AUE_AUDITON_GETCWD);
432
433 case A_GETCAR:
434 return (AUE_AUDITON_GETCAR);
435
436 case A_GETSTAT:
437 return (AUE_AUDITON_GETSTAT);
438
439 case A_SETSTAT:
440 return (AUE_AUDITON_SETSTAT);
441
442 case A_SETUMASK:
443 return (AUE_AUDITON_SETUMASK);
444
445 case A_SETSMASK:
446 return (AUE_AUDITON_SETSMASK);
447
448 case A_GETCOND:
449 return (AUE_AUDITON_GETCOND);
450
451 case A_SETCOND:
452 return (AUE_AUDITON_SETCOND);
453
454 case A_GETCLASS:
455 return (AUE_AUDITON_GETCLASS);
456
457 case A_SETCLASS:
458 return (AUE_AUDITON_SETCLASS);
459
460 case A_GETPINFO:
461 case A_SETPMASK:
462 case A_SETFSIZE:
463 case A_GETFSIZE:
464 case A_GETPINFO_ADDR:
465 case A_GETKAUDIT:
466 case A_SETKAUDIT:
467 default:
468 return (AUE_AUDITON); /* No special record */
469 }
470}
471
472/*
473 * Create a canonical path from given path by prefixing either the root
474 * directory, or the current working directory. If the process working
475 * directory is NULL, we could use 'rootvnode' to obtain the root directoty,
476 * but this results in a volfs name written to the audit log. So we will
477 * leave the filename starting with '/' in the audit log in this case.
478 *
479 * XXXRW: Since we combine two paths here, ideally a buffer of size
480 * MAXPATHLEN * 2 would be passed in.
481 */
482void
483canon_path(struct thread *td, char *path, char *cpath)
484{
485 char *bufp;
486 char *retbuf, *freebuf;
487 struct vnode *vnp;
488 struct filedesc *fdp;
489 int cisr, error, vfslocked;
490
491 fdp = td->td_proc->p_fd;
492 bufp = path;
493 cisr = 0;
494 FILEDESC_LOCK(fdp);
495 if (*(path) == '/') {
496 while (*(bufp) == '/')
497 bufp++; /* Skip leading '/'s. */
498 /*
499 * If no process root, or it is the same as the system root,
500 * audit the path as passed in with a single '/'.
501 */
502 if ((fdp->fd_rdir == NULL) ||
503 (fdp->fd_rdir == rootvnode)) {
504 vnp = NULL;
505 bufp--; /* Restore one '/'. */
506 } else {
507 vnp = fdp->fd_rdir; /* Use process root. */
508 vref(vnp);
509 }
510 } else {
511 vnp = fdp->fd_cdir; /* Prepend the current dir. */
512 cisr = (fdp->fd_rdir == fdp->fd_cdir);
513 vref(vnp);
514 bufp = path;
515 }
516 FILEDESC_UNLOCK(fdp);
517 if (vnp != NULL) {
518 /*
519 * XXX: vn_fullpath() on FreeBSD is "less reliable" than
520 * vn_getpath() on Darwin, so this will need more attention
521 * in the future. Also, the question and string bounding
522 * here seems a bit questionable and will also require
523 * attention.
524 */
525 vfslocked = VFS_LOCK_GIANT(vnp->v_mount);
526 vn_lock(vnp, LK_EXCLUSIVE | LK_RETRY, td);
527 error = vn_fullpath(td, vnp, &retbuf, &freebuf);
528 if (error == 0) {
529 /* Copy and free buffer allocated by vn_fullpath().
530 * If the current working directory was the same as
531 * the root directory, and the path was a relative
532 * pathname, do not separate the two components with
533 * the '/' character.
534 */
535 snprintf(cpath, MAXPATHLEN, "%s%s%s", retbuf,
536 cisr ? "" : "/", bufp);
537 free(freebuf, M_TEMP);
538 } else
539 cpath[0] = '\0';
540 vput(vnp);
541 VFS_UNLOCK_GIANT(vfslocked);
542 } else {
543 strlcpy(cpath, bufp, MAXPATHLEN);
544 }
545}
|