xref: /freebsd/sys/security/audit/audit_syscalls.c (revision 61e21613)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1999-2009 Apple Inc.
5  * Copyright (c) 2016, 2018 Robert N. M. Watson
6  * All rights reserved.
7  *
8  * Portions of this software were developed by BAE Systems, the University of
9  * Cambridge Computer Laboratory, and Memorial University under DARPA/AFRL
10  * contract FA8650-15-C-7558 ("CADETS"), as part of the DARPA Transparent
11  * Computing (TC) research program.
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1.  Redistributions of source code must retain the above copyright
17  *     notice, this list of conditions and the following disclaimer.
18  * 2.  Redistributions in binary form must reproduce the above copyright
19  *     notice, this list of conditions and the following disclaimer in the
20  *     documentation and/or other materials provided with the distribution.
21  * 3.  Neither the name of Apple Inc. ("Apple") nor the names of
22  *     its contributors may be used to endorse or promote products derived
23  *     from this software without specific prior written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28  * ARE DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR
29  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
33  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
34  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35  * POSSIBILITY OF SUCH DAMAGE.
36  */
37 
38 #include <sys/param.h>
39 #include <sys/mount.h>
40 #include <sys/namei.h>
41 #include <sys/priv.h>
42 #include <sys/proc.h>
43 #include <sys/sysproto.h>
44 #include <sys/systm.h>
45 #include <sys/vnode.h>
46 #include <sys/jail.h>
47 
48 #include <bsm/audit.h>
49 #include <bsm/audit_kevents.h>
50 
51 #include <security/audit/audit.h>
52 #include <security/audit/audit_private.h>
53 #include <security/mac/mac_framework.h>
54 
55 #ifdef AUDIT
56 
57 /*
58  * System call to allow a user space application to submit a BSM audit record
59  * to the kernel for inclusion in the audit log.  This function does little
60  * verification on the audit record that is submitted.
61  *
62  * XXXAUDIT: Audit preselection for user records does not currently work,
63  * since we pre-select only based on the AUE_audit event type, not the event
64  * type submitted as part of the user audit data.
65  */
66 /* ARGSUSED */
67 int
68 sys_audit(struct thread *td, struct audit_args *uap)
69 {
70 	int error;
71 	void * rec;
72 	struct kaudit_record *ar;
73 
74 	if (jailed(td->td_ucred))
75 		return (ENOSYS);
76 	error = priv_check(td, PRIV_AUDIT_SUBMIT);
77 	if (error)
78 		return (error);
79 
80 	if ((uap->length <= 0) || (uap->length > audit_qctrl.aq_bufsz))
81 		return (EINVAL);
82 
83 	ar = currecord();
84 
85 	/*
86 	 * If there's no current audit record (audit() itself not audited)
87 	 * commit the user audit record.
88 	 */
89 	if (ar == NULL) {
90 		/*
91 		 * This is not very efficient; we're required to allocate a
92 		 * complete kernel audit record just so the user record can
93 		 * tag along.
94 		 *
95 		 * XXXAUDIT: Maybe AUE_AUDIT in the system call context and
96 		 * special pre-select handling?
97 		 */
98 		td->td_ar = audit_new(AUE_NULL, td);
99 		if (td->td_ar == NULL)
100 			return (ENOTSUP);
101 		td->td_pflags |= TDP_AUDITREC;
102 		ar = td->td_ar;
103 	}
104 
105 	if (uap->length > MAX_AUDIT_RECORD_SIZE)
106 		return (EINVAL);
107 
108 	rec = malloc(uap->length, M_AUDITDATA, M_WAITOK);
109 
110 	error = copyin(uap->record, rec, uap->length);
111 	if (error)
112 		goto free_out;
113 
114 	/* Verify the record. */
115 	if (bsm_rec_verify(rec) == 0) {
116 		error = EINVAL;
117 		goto free_out;
118 	}
119 
120 #ifdef MAC
121 	error = mac_system_check_audit(td->td_ucred, rec, uap->length);
122 	if (error)
123 		goto free_out;
124 #endif
125 
126 	/*
127 	 * Attach the user audit record to the kernel audit record.  Because
128 	 * this system call is an auditable event, we will write the user
129 	 * record along with the record for this audit event.
130 	 *
131 	 * XXXAUDIT: KASSERT appropriate starting values of k_udata, k_ulen,
132 	 * k_ar_commit & AR_COMMIT_USER?
133 	 */
134 	ar->k_udata = rec;
135 	ar->k_ulen  = uap->length;
136 	ar->k_ar_commit |= AR_COMMIT_USER;
137 
138 	/*
139 	 * Currently we assume that all preselection has been performed in
140 	 * userspace.  We unconditionally set these masks so that the records
141 	 * get committed both to the trail and pipe.  In the future we will
142 	 * want to setup kernel based preselection.
143 	 */
144 	ar->k_ar_commit |= (AR_PRESELECT_USER_TRAIL | AR_PRESELECT_USER_PIPE);
145 	return (0);
146 
147 free_out:
148 	/*
149 	 * audit_syscall_exit() will free the audit record on the thread even
150 	 * if we allocated it above.
151 	 */
152 	free(rec, M_AUDITDATA);
153 	return (error);
154 }
155 
156 /*
157  *  System call to manipulate auditing.
158  */
159 /* ARGSUSED */
160 int
161 sys_auditon(struct thread *td, struct auditon_args *uap)
162 {
163 	struct ucred *cred, *newcred, *oldcred;
164 	int error;
165 	union auditon_udata udata;
166 	struct proc *tp;
167 
168 	if (jailed(td->td_ucred))
169 		return (ENOSYS);
170 	AUDIT_ARG_CMD(uap->cmd);
171 
172 #ifdef MAC
173 	error = mac_system_check_auditon(td->td_ucred, uap->cmd);
174 	if (error)
175 		return (error);
176 #endif
177 
178 	error = priv_check(td, PRIV_AUDIT_CONTROL);
179 	if (error)
180 		return (error);
181 
182 	if ((uap->length <= 0) || (uap->length > sizeof(union auditon_udata)))
183 		return (EINVAL);
184 
185 	memset((void *)&udata, 0, sizeof(udata));
186 
187 	/*
188 	 * Some of the GET commands use the arguments too.
189 	 */
190 	switch (uap->cmd) {
191 	case A_SETPOLICY:
192 	case A_OLDSETPOLICY:
193 	case A_SETKMASK:
194 	case A_SETQCTRL:
195 	case A_OLDSETQCTRL:
196 	case A_SETSTAT:
197 	case A_SETUMASK:
198 	case A_SETSMASK:
199 	case A_SETCOND:
200 	case A_OLDSETCOND:
201 	case A_SETCLASS:
202 	case A_SETEVENT:
203 	case A_SETPMASK:
204 	case A_SETFSIZE:
205 	case A_SETKAUDIT:
206 	case A_GETCLASS:
207 	case A_GETEVENT:
208 	case A_GETPINFO:
209 	case A_GETPINFO_ADDR:
210 	case A_SENDTRIGGER:
211 		error = copyin(uap->data, (void *)&udata, uap->length);
212 		if (error)
213 			return (error);
214 		AUDIT_ARG_AUDITON(&udata);
215 		break;
216 	}
217 
218 	/*
219 	 * XXXAUDIT: Locking?
220 	 */
221 	switch (uap->cmd) {
222 	case A_OLDGETPOLICY:
223 	case A_GETPOLICY:
224 		if (uap->length == sizeof(udata.au_policy64)) {
225 			if (!audit_fail_stop)
226 				udata.au_policy64 |= AUDIT_CNT;
227 			if (audit_panic_on_write_fail)
228 				udata.au_policy64 |= AUDIT_AHLT;
229 			if (audit_argv)
230 				udata.au_policy64 |= AUDIT_ARGV;
231 			if (audit_arge)
232 				udata.au_policy64 |= AUDIT_ARGE;
233 			break;
234 		}
235 		if (uap->length != sizeof(udata.au_policy))
236 			return (EINVAL);
237 		if (!audit_fail_stop)
238 			udata.au_policy |= AUDIT_CNT;
239 		if (audit_panic_on_write_fail)
240 			udata.au_policy |= AUDIT_AHLT;
241 		if (audit_argv)
242 			udata.au_policy |= AUDIT_ARGV;
243 		if (audit_arge)
244 			udata.au_policy |= AUDIT_ARGE;
245 		break;
246 
247 	case A_OLDSETPOLICY:
248 	case A_SETPOLICY:
249 		if (uap->length == sizeof(udata.au_policy64)) {
250 			if (udata.au_policy & ~(AUDIT_CNT|AUDIT_AHLT|
251 			    AUDIT_ARGV|AUDIT_ARGE))
252 				return (EINVAL);
253 			audit_fail_stop = ((udata.au_policy64 & AUDIT_CNT) ==
254 			    0);
255 			audit_panic_on_write_fail = (udata.au_policy64 &
256 			    AUDIT_AHLT);
257 			audit_argv = (udata.au_policy64 & AUDIT_ARGV);
258 			audit_arge = (udata.au_policy64 & AUDIT_ARGE);
259 			break;
260 		}
261 		if (uap->length != sizeof(udata.au_policy))
262 			return (EINVAL);
263 		if (udata.au_policy & ~(AUDIT_CNT|AUDIT_AHLT|AUDIT_ARGV|
264 		    AUDIT_ARGE))
265 			return (EINVAL);
266 		/*
267 		 * XXX - Need to wake up waiters if the policy relaxes?
268 		 */
269 		audit_fail_stop = ((udata.au_policy & AUDIT_CNT) == 0);
270 		audit_panic_on_write_fail = (udata.au_policy & AUDIT_AHLT);
271 		audit_argv = (udata.au_policy & AUDIT_ARGV);
272 		audit_arge = (udata.au_policy & AUDIT_ARGE);
273 		break;
274 
275 	case A_GETKMASK:
276 		if (uap->length != sizeof(udata.au_mask))
277 			return (EINVAL);
278 		udata.au_mask = audit_nae_mask;
279 		break;
280 
281 	case A_SETKMASK:
282 		if (uap->length != sizeof(udata.au_mask))
283 			return (EINVAL);
284 		audit_nae_mask = udata.au_mask;
285 		break;
286 
287 	case A_OLDGETQCTRL:
288 	case A_GETQCTRL:
289 		if (uap->length == sizeof(udata.au_qctrl64)) {
290 			udata.au_qctrl64.aq64_hiwater =
291 			    (u_int64_t)audit_qctrl.aq_hiwater;
292 			udata.au_qctrl64.aq64_lowater =
293 			    (u_int64_t)audit_qctrl.aq_lowater;
294 			udata.au_qctrl64.aq64_bufsz =
295 			    (u_int64_t)audit_qctrl.aq_bufsz;
296 			udata.au_qctrl64.aq64_minfree =
297 			    (u_int64_t)audit_qctrl.aq_minfree;
298 			break;
299 		}
300 		if (uap->length != sizeof(udata.au_qctrl))
301 			return (EINVAL);
302 		udata.au_qctrl = audit_qctrl;
303 		break;
304 
305 	case A_OLDSETQCTRL:
306 	case A_SETQCTRL:
307 		if (uap->length == sizeof(udata.au_qctrl64)) {
308 			/* NB: aq64_minfree is unsigned unlike aq_minfree. */
309 			if ((udata.au_qctrl64.aq64_hiwater > AQ_MAXHIGH) ||
310 			    (udata.au_qctrl64.aq64_lowater >=
311 			    udata.au_qctrl.aq_hiwater) ||
312 			    (udata.au_qctrl64.aq64_bufsz > AQ_MAXBUFSZ) ||
313 			    (udata.au_qctrl64.aq64_minfree > 100))
314 				return (EINVAL);
315 			audit_qctrl.aq_hiwater =
316 			    (int)udata.au_qctrl64.aq64_hiwater;
317 			audit_qctrl.aq_lowater =
318 			    (int)udata.au_qctrl64.aq64_lowater;
319 			audit_qctrl.aq_bufsz =
320 			    (int)udata.au_qctrl64.aq64_bufsz;
321 			audit_qctrl.aq_minfree =
322 			    (int)udata.au_qctrl64.aq64_minfree;
323 			audit_qctrl.aq_delay = -1;	/* Not used. */
324 			break;
325 		}
326 		if (uap->length != sizeof(udata.au_qctrl))
327 			return (EINVAL);
328 		if ((udata.au_qctrl.aq_hiwater > AQ_MAXHIGH) ||
329 		    (udata.au_qctrl.aq_lowater >= udata.au_qctrl.aq_hiwater) ||
330 		    (udata.au_qctrl.aq_bufsz > AQ_MAXBUFSZ) ||
331 		    (udata.au_qctrl.aq_minfree < 0) ||
332 		    (udata.au_qctrl.aq_minfree > 100))
333 			return (EINVAL);
334 
335 		audit_qctrl = udata.au_qctrl;
336 		/* XXX The queue delay value isn't used with the kernel. */
337 		audit_qctrl.aq_delay = -1;
338 		break;
339 
340 	case A_GETCWD:
341 		return (ENOSYS);
342 		break;
343 
344 	case A_GETCAR:
345 		return (ENOSYS);
346 		break;
347 
348 	case A_GETSTAT:
349 		return (ENOSYS);
350 		break;
351 
352 	case A_SETSTAT:
353 		return (ENOSYS);
354 		break;
355 
356 	case A_SETUMASK:
357 		return (ENOSYS);
358 		break;
359 
360 	case A_SETSMASK:
361 		return (ENOSYS);
362 		break;
363 
364 	case A_OLDGETCOND:
365 	case A_GETCOND:
366 		if (uap->length == sizeof(udata.au_cond64)) {
367 			if (audit_trail_enabled && !audit_trail_suspended)
368 				udata.au_cond64 = AUC_AUDITING;
369 			else
370 				udata.au_cond64 = AUC_NOAUDIT;
371 			break;
372 		}
373 		if (uap->length != sizeof(udata.au_cond))
374 			return (EINVAL);
375 		if (audit_trail_enabled && !audit_trail_suspended)
376 			udata.au_cond = AUC_AUDITING;
377 		else
378 			udata.au_cond = AUC_NOAUDIT;
379 		break;
380 
381 	case A_OLDSETCOND:
382 	case A_SETCOND:
383 		if (uap->length == sizeof(udata.au_cond64)) {
384 			if (udata.au_cond64 == AUC_NOAUDIT)
385 				audit_trail_suspended = 1;
386 			if (udata.au_cond64 == AUC_AUDITING)
387 				audit_trail_suspended = 0;
388 			if (udata.au_cond64 == AUC_DISABLED) {
389 				audit_trail_suspended = 1;
390 				audit_shutdown(NULL, 0);
391 			}
392 			audit_syscalls_enabled_update();
393 			break;
394 		}
395 		if (uap->length != sizeof(udata.au_cond))
396 			return (EINVAL);
397 		if (udata.au_cond == AUC_NOAUDIT)
398 			audit_trail_suspended = 1;
399 		if (udata.au_cond == AUC_AUDITING)
400 			audit_trail_suspended = 0;
401 		if (udata.au_cond == AUC_DISABLED) {
402 			audit_trail_suspended = 1;
403 			audit_shutdown(NULL, 0);
404 		}
405 		audit_syscalls_enabled_update();
406 		break;
407 
408 	case A_GETCLASS:
409 		if (uap->length != sizeof(udata.au_evclass))
410 			return (EINVAL);
411 		udata.au_evclass.ec_class = au_event_class(
412 		    udata.au_evclass.ec_number);
413 		break;
414 
415 	case A_GETEVENT:
416 		if (uap->length != sizeof(udata.au_evname))
417 			return (EINVAL);
418 		error = au_event_name(udata.au_evname.en_number,
419 		    udata.au_evname.en_name);
420 		if (error != 0)
421 			return (error);
422 		break;
423 
424 	case A_SETCLASS:
425 		if (uap->length != sizeof(udata.au_evclass))
426 			return (EINVAL);
427 		au_evclassmap_insert(udata.au_evclass.ec_number,
428 		    udata.au_evclass.ec_class);
429 		break;
430 
431 	case A_SETEVENT:
432 		if (uap->length != sizeof(udata.au_evname))
433 			return (EINVAL);
434 
435 		/* Ensure nul termination from userspace. */
436 		udata.au_evname.en_name[sizeof(udata.au_evname.en_name) - 1]
437 		    = 0;
438 		au_evnamemap_insert(udata.au_evname.en_number,
439 		    udata.au_evname.en_name);
440 		break;
441 
442 	case A_GETPINFO:
443 		if (uap->length != sizeof(udata.au_aupinfo))
444 			return (EINVAL);
445 		if (udata.au_aupinfo.ap_pid < 1)
446 			return (ESRCH);
447 		if ((tp = pfind(udata.au_aupinfo.ap_pid)) == NULL)
448 			return (ESRCH);
449 		if ((error = p_cansee(td, tp)) != 0) {
450 			PROC_UNLOCK(tp);
451 			return (error);
452 		}
453 		cred = tp->p_ucred;
454 		if (cred->cr_audit.ai_termid.at_type == AU_IPv6) {
455 			PROC_UNLOCK(tp);
456 			return (EINVAL);
457 		}
458 		udata.au_aupinfo.ap_auid = cred->cr_audit.ai_auid;
459 		udata.au_aupinfo.ap_mask.am_success =
460 		    cred->cr_audit.ai_mask.am_success;
461 		udata.au_aupinfo.ap_mask.am_failure =
462 		    cred->cr_audit.ai_mask.am_failure;
463 		udata.au_aupinfo.ap_termid.machine =
464 		    cred->cr_audit.ai_termid.at_addr[0];
465 		udata.au_aupinfo.ap_termid.port =
466 		    (dev_t)cred->cr_audit.ai_termid.at_port;
467 		udata.au_aupinfo.ap_asid = cred->cr_audit.ai_asid;
468 		PROC_UNLOCK(tp);
469 		break;
470 
471 	case A_SETPMASK:
472 		if (uap->length != sizeof(udata.au_aupinfo))
473 			return (EINVAL);
474 		if (udata.au_aupinfo.ap_pid < 1)
475 			return (ESRCH);
476 		newcred = crget();
477 		if ((tp = pfind(udata.au_aupinfo.ap_pid)) == NULL) {
478 			crfree(newcred);
479 			return (ESRCH);
480 		}
481 		if ((error = p_cansee(td, tp)) != 0) {
482 			PROC_UNLOCK(tp);
483 			crfree(newcred);
484 			return (error);
485 		}
486 		oldcred = tp->p_ucred;
487 		crcopy(newcred, oldcred);
488 		newcred->cr_audit.ai_mask.am_success =
489 		    udata.au_aupinfo.ap_mask.am_success;
490 		newcred->cr_audit.ai_mask.am_failure =
491 		    udata.au_aupinfo.ap_mask.am_failure;
492 		proc_set_cred(tp, newcred);
493 		PROC_UNLOCK(tp);
494 		crfree(oldcred);
495 		break;
496 
497 	case A_SETFSIZE:
498 		if (uap->length != sizeof(udata.au_fstat))
499 			return (EINVAL);
500 		if ((udata.au_fstat.af_filesz != 0) &&
501 		   (udata.au_fstat.af_filesz < MIN_AUDIT_FILE_SIZE))
502 			return (EINVAL);
503 		audit_fstat.af_filesz = udata.au_fstat.af_filesz;
504 		break;
505 
506 	case A_GETFSIZE:
507 		if (uap->length != sizeof(udata.au_fstat))
508 			return (EINVAL);
509 		udata.au_fstat.af_filesz = audit_fstat.af_filesz;
510 		udata.au_fstat.af_currsz = audit_fstat.af_currsz;
511 		break;
512 
513 	case A_GETPINFO_ADDR:
514 		if (uap->length != sizeof(udata.au_aupinfo_addr))
515 			return (EINVAL);
516 		if (udata.au_aupinfo_addr.ap_pid < 1)
517 			return (ESRCH);
518 		if ((tp = pfind(udata.au_aupinfo_addr.ap_pid)) == NULL)
519 			return (ESRCH);
520 		cred = tp->p_ucred;
521 		udata.au_aupinfo_addr.ap_auid = cred->cr_audit.ai_auid;
522 		udata.au_aupinfo_addr.ap_mask.am_success =
523 		    cred->cr_audit.ai_mask.am_success;
524 		udata.au_aupinfo_addr.ap_mask.am_failure =
525 		    cred->cr_audit.ai_mask.am_failure;
526 		udata.au_aupinfo_addr.ap_termid = cred->cr_audit.ai_termid;
527 		udata.au_aupinfo_addr.ap_asid = cred->cr_audit.ai_asid;
528 		PROC_UNLOCK(tp);
529 		break;
530 
531 	case A_GETKAUDIT:
532 		if (uap->length != sizeof(udata.au_kau_info))
533 			return (EINVAL);
534 		audit_get_kinfo(&udata.au_kau_info);
535 		break;
536 
537 	case A_SETKAUDIT:
538 		if (uap->length != sizeof(udata.au_kau_info))
539 			return (EINVAL);
540 		if (udata.au_kau_info.ai_termid.at_type != AU_IPv4 &&
541 		    udata.au_kau_info.ai_termid.at_type != AU_IPv6)
542 			return (EINVAL);
543 		audit_set_kinfo(&udata.au_kau_info);
544 		break;
545 
546 	case A_SENDTRIGGER:
547 		if (uap->length != sizeof(udata.au_trigger))
548 			return (EINVAL);
549 		if ((udata.au_trigger < AUDIT_TRIGGER_MIN) ||
550 		    (udata.au_trigger > AUDIT_TRIGGER_MAX))
551 			return (EINVAL);
552 		return (audit_send_trigger(udata.au_trigger));
553 
554 	default:
555 		return (EINVAL);
556 	}
557 
558 	/*
559 	 * Copy data back to userspace for the GET comands.
560 	 */
561 	switch (uap->cmd) {
562 	case A_GETPOLICY:
563 	case A_OLDGETPOLICY:
564 	case A_GETKMASK:
565 	case A_GETQCTRL:
566 	case A_OLDGETQCTRL:
567 	case A_GETCWD:
568 	case A_GETCAR:
569 	case A_GETSTAT:
570 	case A_GETCOND:
571 	case A_OLDGETCOND:
572 	case A_GETCLASS:
573 	case A_GETPINFO:
574 	case A_GETFSIZE:
575 	case A_GETPINFO_ADDR:
576 	case A_GETKAUDIT:
577 		error = copyout((void *)&udata, uap->data, uap->length);
578 		if (error)
579 			return (error);
580 		break;
581 	}
582 
583 	return (0);
584 }
585 
586 /*
587  * System calls to manage the user audit information.
588  */
589 /* ARGSUSED */
590 int
591 sys_getauid(struct thread *td, struct getauid_args *uap)
592 {
593 	int error;
594 
595 	if (jailed(td->td_ucred))
596 		return (ENOSYS);
597 	error = priv_check(td, PRIV_AUDIT_GETAUDIT);
598 	if (error)
599 		return (error);
600 	return (copyout(&td->td_ucred->cr_audit.ai_auid, uap->auid,
601 	    sizeof(td->td_ucred->cr_audit.ai_auid)));
602 }
603 
604 /* ARGSUSED */
605 int
606 sys_setauid(struct thread *td, struct setauid_args *uap)
607 {
608 	struct ucred *newcred, *oldcred;
609 	au_id_t id;
610 	int error;
611 
612 	if (jailed(td->td_ucred))
613 		return (ENOSYS);
614 	error = copyin(uap->auid, &id, sizeof(id));
615 	if (error)
616 		return (error);
617 	audit_arg_auid(id);
618 	newcred = crget();
619 	PROC_LOCK(td->td_proc);
620 	oldcred = td->td_proc->p_ucred;
621 	crcopy(newcred, oldcred);
622 #ifdef MAC
623 	error = mac_cred_check_setauid(oldcred, id);
624 	if (error)
625 		goto fail;
626 #endif
627 	error = priv_check_cred(oldcred, PRIV_AUDIT_SETAUDIT);
628 	if (error)
629 		goto fail;
630 	newcred->cr_audit.ai_auid = id;
631 	proc_set_cred(td->td_proc, newcred);
632 	PROC_UNLOCK(td->td_proc);
633 	crfree(oldcred);
634 	return (0);
635 fail:
636 	PROC_UNLOCK(td->td_proc);
637 	crfree(newcred);
638 	return (error);
639 }
640 
641 /*
642  * System calls to get and set process audit information.
643  */
644 /* ARGSUSED */
645 int
646 sys_getaudit(struct thread *td, struct getaudit_args *uap)
647 {
648 	struct auditinfo ai;
649 	struct ucred *cred;
650 	int error;
651 
652 	cred = td->td_ucred;
653 	if (jailed(cred))
654 		return (ENOSYS);
655 	error = priv_check(td, PRIV_AUDIT_GETAUDIT);
656 	if (error)
657 		return (error);
658 	if (cred->cr_audit.ai_termid.at_type == AU_IPv6)
659 		return (E2BIG);
660 	bzero(&ai, sizeof(ai));
661 	ai.ai_auid = cred->cr_audit.ai_auid;
662 	ai.ai_mask = cred->cr_audit.ai_mask;
663 	ai.ai_asid = cred->cr_audit.ai_asid;
664 	ai.ai_termid.machine = cred->cr_audit.ai_termid.at_addr[0];
665 	ai.ai_termid.port = cred->cr_audit.ai_termid.at_port;
666 	return (copyout(&ai, uap->auditinfo, sizeof(ai)));
667 }
668 
669 /* ARGSUSED */
670 int
671 sys_setaudit(struct thread *td, struct setaudit_args *uap)
672 {
673 	struct ucred *newcred, *oldcred;
674 	struct auditinfo ai;
675 	int error;
676 
677 	if (jailed(td->td_ucred))
678 		return (ENOSYS);
679 	error = copyin(uap->auditinfo, &ai, sizeof(ai));
680 	if (error)
681 		return (error);
682 	audit_arg_auditinfo(&ai);
683 	newcred = crget();
684 	PROC_LOCK(td->td_proc);
685 	oldcred = td->td_proc->p_ucred;
686 	crcopy(newcred, oldcred);
687 #ifdef MAC
688 	error = mac_cred_check_setaudit(oldcred, &ai);
689 	if (error)
690 		goto fail;
691 #endif
692 	error = priv_check_cred(oldcred, PRIV_AUDIT_SETAUDIT);
693 	if (error)
694 		goto fail;
695 	bzero(&newcred->cr_audit, sizeof(newcred->cr_audit));
696 	newcred->cr_audit.ai_auid = ai.ai_auid;
697 	newcred->cr_audit.ai_mask = ai.ai_mask;
698 	newcred->cr_audit.ai_asid = ai.ai_asid;
699 	newcred->cr_audit.ai_termid.at_addr[0] = ai.ai_termid.machine;
700 	newcred->cr_audit.ai_termid.at_port = ai.ai_termid.port;
701 	newcred->cr_audit.ai_termid.at_type = AU_IPv4;
702 	proc_set_cred(td->td_proc, newcred);
703 	PROC_UNLOCK(td->td_proc);
704 	crfree(oldcred);
705 	return (0);
706 fail:
707 	PROC_UNLOCK(td->td_proc);
708 	crfree(newcred);
709 	return (error);
710 }
711 
712 /* ARGSUSED */
713 int
714 sys_getaudit_addr(struct thread *td, struct getaudit_addr_args *uap)
715 {
716 	int error;
717 
718 	if (jailed(td->td_ucred))
719 		return (ENOSYS);
720 	if (uap->length < sizeof(*uap->auditinfo_addr))
721 		return (EOVERFLOW);
722 	error = priv_check(td, PRIV_AUDIT_GETAUDIT);
723 	if (error)
724 		return (error);
725 	return (copyout(&td->td_ucred->cr_audit, uap->auditinfo_addr,
726 	    sizeof(*uap->auditinfo_addr)));
727 }
728 
729 /* ARGSUSED */
730 int
731 sys_setaudit_addr(struct thread *td, struct setaudit_addr_args *uap)
732 {
733 	struct ucred *newcred, *oldcred;
734 	struct auditinfo_addr aia;
735 	int error;
736 
737 	if (jailed(td->td_ucred))
738 		return (ENOSYS);
739 	error = copyin(uap->auditinfo_addr, &aia, sizeof(aia));
740 	if (error)
741 		return (error);
742 	audit_arg_auditinfo_addr(&aia);
743 	if (aia.ai_termid.at_type != AU_IPv6 &&
744 	    aia.ai_termid.at_type != AU_IPv4)
745 		return (EINVAL);
746 	newcred = crget();
747 	PROC_LOCK(td->td_proc);
748 	oldcred = td->td_proc->p_ucred;
749 	crcopy(newcred, oldcred);
750 #ifdef MAC
751 	error = mac_cred_check_setaudit_addr(oldcred, &aia);
752 	if (error)
753 		goto fail;
754 #endif
755 	error = priv_check_cred(oldcred, PRIV_AUDIT_SETAUDIT);
756 	if (error)
757 		goto fail;
758 	newcred->cr_audit = aia;
759 	proc_set_cred(td->td_proc, newcred);
760 	PROC_UNLOCK(td->td_proc);
761 	crfree(oldcred);
762 	return (0);
763 fail:
764 	PROC_UNLOCK(td->td_proc);
765 	crfree(newcred);
766 	return (error);
767 }
768 
769 /*
770  * Syscall to manage audit files.
771  */
772 /* ARGSUSED */
773 int
774 sys_auditctl(struct thread *td, struct auditctl_args *uap)
775 {
776 	struct nameidata nd;
777 	struct ucred *cred;
778 	struct vnode *vp;
779 	int error = 0;
780 	int flags;
781 
782 	if (jailed(td->td_ucred))
783 		return (ENOSYS);
784 	error = priv_check(td, PRIV_AUDIT_CONTROL);
785 	if (error)
786 		return (error);
787 
788 	vp = NULL;
789 	cred = NULL;
790 
791 	/*
792 	 * If a path is specified, open the replacement vnode, perform
793 	 * validity checks, and grab another reference to the current
794 	 * credential.
795 	 *
796 	 * On Darwin, a NULL path argument is also used to disable audit.
797 	 */
798 	if (uap->path == NULL)
799 		return (EINVAL);
800 
801 	NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1, UIO_USERSPACE,
802 	    uap->path);
803 	flags = AUDIT_OPEN_FLAGS;
804 	error = vn_open(&nd, &flags, 0, NULL);
805 	if (error)
806 		return (error);
807 	vp = nd.ni_vp;
808 #ifdef MAC
809 	error = mac_system_check_auditctl(td->td_ucred, vp);
810 	VOP_UNLOCK(vp);
811 	if (error) {
812 		vn_close(vp, AUDIT_CLOSE_FLAGS, td->td_ucred, td);
813 		return (error);
814 	}
815 #else
816 	VOP_UNLOCK(vp);
817 #endif
818 	NDFREE_PNBUF(&nd);
819 	if (vp->v_type != VREG) {
820 		vn_close(vp, AUDIT_CLOSE_FLAGS, td->td_ucred, td);
821 		return (EINVAL);
822 	}
823 	cred = td->td_ucred;
824 	crhold(cred);
825 
826 	/*
827 	 * XXXAUDIT: Should audit_trail_suspended actually be cleared by
828 	 * audit_worker?
829 	 */
830 	audit_trail_suspended = 0;
831 	audit_syscalls_enabled_update();
832 
833 	audit_rotate_vnode(cred, vp);
834 
835 	return (error);
836 }
837 
838 #else /* !AUDIT */
839 
840 int
841 sys_audit(struct thread *td, struct audit_args *uap)
842 {
843 
844 	return (ENOSYS);
845 }
846 
847 int
848 sys_auditon(struct thread *td, struct auditon_args *uap)
849 {
850 
851 	return (ENOSYS);
852 }
853 
854 int
855 sys_getauid(struct thread *td, struct getauid_args *uap)
856 {
857 
858 	return (ENOSYS);
859 }
860 
861 int
862 sys_setauid(struct thread *td, struct setauid_args *uap)
863 {
864 
865 	return (ENOSYS);
866 }
867 
868 int
869 sys_getaudit(struct thread *td, struct getaudit_args *uap)
870 {
871 
872 	return (ENOSYS);
873 }
874 
875 int
876 sys_setaudit(struct thread *td, struct setaudit_args *uap)
877 {
878 
879 	return (ENOSYS);
880 }
881 
882 int
883 sys_getaudit_addr(struct thread *td, struct getaudit_addr_args *uap)
884 {
885 
886 	return (ENOSYS);
887 }
888 
889 int
890 sys_setaudit_addr(struct thread *td, struct setaudit_addr_args *uap)
891 {
892 
893 	return (ENOSYS);
894 }
895 
896 int
897 sys_auditctl(struct thread *td, struct auditctl_args *uap)
898 {
899 
900 	return (ENOSYS);
901 }
902 #endif /* AUDIT */
903