1/*
2 * Copyright (c) 1999-2005 Apple Computer, Inc.
3 * Copyright (c) 2006 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 *
| 1/*
2 * Copyright (c) 1999-2005 Apple Computer, Inc.
3 * Copyright (c) 2006 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.c 162176 2006-09-09 10:23:00Z rwatson $
| 30 * $FreeBSD: head/sys/security/audit/audit.c 162380 2006-09-17 17:52:57Z csjp $
|
31 */
32
33#include <sys/param.h>
34#include <sys/condvar.h>
35#include <sys/conf.h>
36#include <sys/file.h>
37#include <sys/filedesc.h>
38#include <sys/fcntl.h>
39#include <sys/ipc.h>
40#include <sys/kernel.h>
41#include <sys/kthread.h>
42#include <sys/malloc.h>
43#include <sys/mount.h>
44#include <sys/namei.h>
45#include <sys/proc.h>
46#include <sys/queue.h>
47#include <sys/socket.h>
48#include <sys/socketvar.h>
49#include <sys/protosw.h>
50#include <sys/domain.h>
51#include <sys/sysproto.h>
52#include <sys/sysent.h>
53#include <sys/systm.h>
54#include <sys/ucred.h>
55#include <sys/uio.h>
56#include <sys/un.h>
57#include <sys/unistd.h>
58#include <sys/vnode.h>
59
60#include <bsm/audit.h>
61#include <bsm/audit_internal.h>
62#include <bsm/audit_kevents.h>
63
64#include <netinet/in.h>
65#include <netinet/in_pcb.h>
66
67#include <security/audit/audit.h>
68#include <security/audit/audit_private.h>
69
70#include <vm/uma.h>
71
72static uma_zone_t audit_record_zone;
73static MALLOC_DEFINE(M_AUDITPROC, "audit_proc", "Audit process storage");
74MALLOC_DEFINE(M_AUDITDATA, "audit_data", "Audit data storage");
75MALLOC_DEFINE(M_AUDITPATH, "audit_path", "Audit path storage");
76MALLOC_DEFINE(M_AUDITTEXT, "audit_text", "Audit text storage");
77
78/*
79 * Audit control settings that are set/read by system calls and are
80 * hence non-static.
81 */
82/*
83 * Define the audit control flags.
84 */
85int audit_enabled;
86int audit_suspended;
87
88/*
89 * Flags controlling behavior in low storage situations. Should we panic if
90 * a write fails? Should we fail stop if we're out of disk space?
91 */
92int audit_panic_on_write_fail;
93int audit_fail_stop;
94int audit_argv;
95int audit_arge;
96
97/*
98 * Are we currently "failing stop" due to out of disk space?
99 */
100int audit_in_failure;
101
102/*
103 * Global audit statistiscs.
104 */
105struct audit_fstat audit_fstat;
106
107/*
108 * Preselection mask for non-attributable events.
109 */
110struct au_mask audit_nae_mask;
111
112/*
113 * Mutex to protect global variables shared between various threads and
114 * processes.
115 */
116struct mtx audit_mtx;
117
118/*
119 * Queue of audit records ready for delivery to disk. We insert new
120 * records at the tail, and remove records from the head. Also,
121 * a count of the number of records used for checking queue depth.
122 * In addition, a counter of records that we have allocated but are
123 * not yet in the queue, which is needed to estimate the total
124 * size of the combined set of records outstanding in the system.
125 */
126struct kaudit_queue audit_q;
127int audit_q_len;
128int audit_pre_q_len;
129
130/*
131 * Audit queue control settings (minimum free, low/high water marks, etc.)
132 */
133struct au_qctrl audit_qctrl;
134
135/*
136 * Condition variable to signal to the worker that it has work to do:
137 * either new records are in the queue, or a log replacement is taking
138 * place.
139 */
140struct cv audit_worker_cv;
141
142/*
143 * Condition variable to flag when crossing the low watermark, meaning that
144 * threads blocked due to hitting the high watermark can wake up and continue
145 * to commit records.
146 */
147struct cv audit_watermark_cv;
148
149/*
150 * Condition variable for auditing threads wait on when in fail-stop mode.
151 * Threads wait on this CV forever (and ever), never seeing the light of
152 * day again.
153 */
154static struct cv audit_fail_cv;
155
156/*
157 * Construct an audit record for the passed thread.
158 */
159static int
160audit_record_ctor(void *mem, int size, void *arg, int flags)
161{
162 struct kaudit_record *ar;
163 struct thread *td;
164
165 KASSERT(sizeof(*ar) == size, ("audit_record_ctor: wrong size"));
166
167 td = arg;
168 ar = mem;
169 bzero(ar, sizeof(*ar));
170 ar->k_ar.ar_magic = AUDIT_RECORD_MAGIC;
171 nanotime(&ar->k_ar.ar_starttime);
172
173 /*
174 * Export the subject credential.
175 */
176 cru2x(td->td_ucred, &ar->k_ar.ar_subj_cred);
177 ar->k_ar.ar_subj_ruid = td->td_ucred->cr_ruid;
178 ar->k_ar.ar_subj_rgid = td->td_ucred->cr_rgid;
179 ar->k_ar.ar_subj_egid = td->td_ucred->cr_groups[0];
180 PROC_LOCK(td->td_proc);
181 ar->k_ar.ar_subj_auid = td->td_proc->p_au->ai_auid;
182 ar->k_ar.ar_subj_asid = td->td_proc->p_au->ai_asid;
183 ar->k_ar.ar_subj_pid = td->td_proc->p_pid;
184 ar->k_ar.ar_subj_amask = td->td_proc->p_au->ai_mask;
185 ar->k_ar.ar_subj_term = td->td_proc->p_au->ai_termid;
186 bcopy(td->td_proc->p_comm, ar->k_ar.ar_subj_comm, MAXCOMLEN);
187 PROC_UNLOCK(td->td_proc);
188
189 return (0);
190}
191
192static void
193audit_record_dtor(void *mem, int size, void *arg)
194{
195 struct kaudit_record *ar;
196
197 KASSERT(sizeof(*ar) == size, ("audit_record_dtor: wrong size"));
198
199 ar = mem;
200 if (ar->k_ar.ar_arg_upath1 != NULL)
201 free(ar->k_ar.ar_arg_upath1, M_AUDITPATH);
202 if (ar->k_ar.ar_arg_upath2 != NULL)
203 free(ar->k_ar.ar_arg_upath2, M_AUDITPATH);
204 if (ar->k_ar.ar_arg_text != NULL)
205 free(ar->k_ar.ar_arg_text, M_AUDITTEXT);
206 if (ar->k_udata != NULL)
207 free(ar->k_udata, M_AUDITDATA);
208 if (ar->k_ar.ar_arg_argv != NULL)
209 free(ar->k_ar.ar_arg_argv, M_AUDITTEXT);
210 if (ar->k_ar.ar_arg_envv != NULL)
211 free(ar->k_ar.ar_arg_envv, M_AUDITTEXT);
212}
213
214/*
215 * Initialize the Audit subsystem: configuration state, work queue,
216 * synchronization primitives, worker thread, and trigger device node. Also
217 * call into the BSM assembly code to initialize it.
218 */
219static void
220audit_init(void)
221{
222
223 printf("Security auditing service present\n");
224 audit_enabled = 0;
225 audit_suspended = 0;
226 audit_panic_on_write_fail = 0;
227 audit_fail_stop = 0;
228 audit_in_failure = 0;
229 audit_argv = 0;
230 audit_arge = 0;
231
232 audit_fstat.af_filesz = 0; /* '0' means unset, unbounded */
233 audit_fstat.af_currsz = 0;
234 audit_nae_mask.am_success = AU_NULL;
235 audit_nae_mask.am_failure = AU_NULL;
236
237 TAILQ_INIT(&audit_q);
238 audit_q_len = 0;
239 audit_pre_q_len = 0;
240 audit_qctrl.aq_hiwater = AQ_HIWATER;
241 audit_qctrl.aq_lowater = AQ_LOWATER;
242 audit_qctrl.aq_bufsz = AQ_BUFSZ;
243 audit_qctrl.aq_minfree = AU_FS_MINFREE;
244
245 mtx_init(&audit_mtx, "audit_mtx", NULL, MTX_DEF);
246 cv_init(&audit_worker_cv, "audit_worker_cv");
247 cv_init(&audit_watermark_cv, "audit_watermark_cv");
248 cv_init(&audit_fail_cv, "audit_fail_cv");
249
250 audit_record_zone = uma_zcreate("audit_record",
251 sizeof(struct kaudit_record), audit_record_ctor,
252 audit_record_dtor, NULL, NULL, UMA_ALIGN_PTR, 0);
253
254 /* Initialize the BSM audit subsystem. */
255 kau_init();
256
257 audit_trigger_init();
258
259 /* Register shutdown handler. */
260 EVENTHANDLER_REGISTER(shutdown_pre_sync, audit_shutdown, NULL,
261 SHUTDOWN_PRI_FIRST);
262
263 /* Start audit worker thread. */
264 audit_worker_init();
265}
266
267SYSINIT(audit_init, SI_SUB_AUDIT, SI_ORDER_FIRST, audit_init, NULL)
268
269/*
270 * Drain the audit queue and close the log at shutdown. Note that this can
271 * be called both from the system shutdown path and also from audit
272 * configuration syscalls, so 'arg' and 'howto' are ignored.
273 */
274void
275audit_shutdown(void *arg, int howto)
276{
277
278 audit_rotate_vnode(NULL, NULL);
279}
280
281/*
282 * Return the current thread's audit record, if any.
283 */
284__inline__ struct kaudit_record *
285currecord(void)
286{
287
288 return (curthread->td_ar);
289}
290
291/*
292 * MPSAFE
293 *
294 * XXXAUDIT: There are a number of races present in the code below due to
295 * release and re-grab of the mutex. The code should be revised to become
296 * slightly less racy.
297 *
298 * XXXAUDIT: Shouldn't there be logic here to sleep waiting on available
299 * pre_q space, suspending the system call until there is room?
300 */
301struct kaudit_record *
302audit_new(int event, struct thread *td)
303{
304 struct kaudit_record *ar;
305 int no_record;
306
307 mtx_lock(&audit_mtx);
308 no_record = (audit_suspended || !audit_enabled);
309 mtx_unlock(&audit_mtx);
310 if (no_record)
311 return (NULL);
312
313 /*
314 * XXX: The number of outstanding uncommitted audit records is
315 * limited to the number of concurrent threads servicing system
316 * calls in the kernel.
317 */
318 ar = uma_zalloc_arg(audit_record_zone, td, M_WAITOK);
319 ar->k_ar.ar_event = event;
320
321 mtx_lock(&audit_mtx);
322 audit_pre_q_len++;
323 mtx_unlock(&audit_mtx);
324
325 return (ar);
326}
327
328void
329audit_free(struct kaudit_record *ar)
330{
331
332 uma_zfree(audit_record_zone, ar);
333}
334
335/*
336 * MPSAFE
337 */
338void
339audit_commit(struct kaudit_record *ar, int error, int retval)
340{
341 au_event_t event;
342 au_class_t class;
343 au_id_t auid;
344 int sorf;
345 struct au_mask *aumask;
346
347 if (ar == NULL)
348 return;
349
350 /*
351 * Decide whether to commit the audit record by checking the
352 * error value from the system call and using the appropriate
353 * audit mask.
354 *
355 * XXXAUDIT: Synchronize access to audit_nae_mask?
356 */
357 if (ar->k_ar.ar_subj_auid == AU_DEFAUDITID)
358 aumask = &audit_nae_mask;
359 else
360 aumask = &ar->k_ar.ar_subj_amask;
361
362 if (error)
363 sorf = AU_PRS_FAILURE;
364 else
365 sorf = AU_PRS_SUCCESS;
366
367 switch(ar->k_ar.ar_event) {
368
369 case AUE_OPEN_RWTC:
370 /* The open syscall always writes a AUE_OPEN_RWTC event; change
371 * it to the proper type of event based on the flags and the
372 * error value.
373 */
374 ar->k_ar.ar_event = flags_and_error_to_openevent(
375 ar->k_ar.ar_arg_fflags, error);
376 break;
377
378 case AUE_SYSCTL:
379 ar->k_ar.ar_event = ctlname_to_sysctlevent(
380 ar->k_ar.ar_arg_ctlname, ar->k_ar.ar_valid_arg);
381 break;
382
383 case AUE_AUDITON:
384 /* Convert the auditon() command to an event */
385 ar->k_ar.ar_event = auditon_command_event(ar->k_ar.ar_arg_cmd);
386 break;
387 }
388
389 auid = ar->k_ar.ar_subj_auid;
390 event = ar->k_ar.ar_event;
391 class = au_event_class(event);
392
393 ar->k_ar_commit |= AR_COMMIT_KERNEL;
394 if (au_preselect(event, class, aumask, sorf) != 0)
395 ar->k_ar_commit |= AR_PRESELECT_TRAIL;
396 if (audit_pipe_preselect(auid, event, class, sorf,
397 ar->k_ar_commit & AR_PRESELECT_TRAIL) != 0)
398 ar->k_ar_commit |= AR_PRESELECT_PIPE;
| 31 */
32
33#include <sys/param.h>
34#include <sys/condvar.h>
35#include <sys/conf.h>
36#include <sys/file.h>
37#include <sys/filedesc.h>
38#include <sys/fcntl.h>
39#include <sys/ipc.h>
40#include <sys/kernel.h>
41#include <sys/kthread.h>
42#include <sys/malloc.h>
43#include <sys/mount.h>
44#include <sys/namei.h>
45#include <sys/proc.h>
46#include <sys/queue.h>
47#include <sys/socket.h>
48#include <sys/socketvar.h>
49#include <sys/protosw.h>
50#include <sys/domain.h>
51#include <sys/sysproto.h>
52#include <sys/sysent.h>
53#include <sys/systm.h>
54#include <sys/ucred.h>
55#include <sys/uio.h>
56#include <sys/un.h>
57#include <sys/unistd.h>
58#include <sys/vnode.h>
59
60#include <bsm/audit.h>
61#include <bsm/audit_internal.h>
62#include <bsm/audit_kevents.h>
63
64#include <netinet/in.h>
65#include <netinet/in_pcb.h>
66
67#include <security/audit/audit.h>
68#include <security/audit/audit_private.h>
69
70#include <vm/uma.h>
71
72static uma_zone_t audit_record_zone;
73static MALLOC_DEFINE(M_AUDITPROC, "audit_proc", "Audit process storage");
74MALLOC_DEFINE(M_AUDITDATA, "audit_data", "Audit data storage");
75MALLOC_DEFINE(M_AUDITPATH, "audit_path", "Audit path storage");
76MALLOC_DEFINE(M_AUDITTEXT, "audit_text", "Audit text storage");
77
78/*
79 * Audit control settings that are set/read by system calls and are
80 * hence non-static.
81 */
82/*
83 * Define the audit control flags.
84 */
85int audit_enabled;
86int audit_suspended;
87
88/*
89 * Flags controlling behavior in low storage situations. Should we panic if
90 * a write fails? Should we fail stop if we're out of disk space?
91 */
92int audit_panic_on_write_fail;
93int audit_fail_stop;
94int audit_argv;
95int audit_arge;
96
97/*
98 * Are we currently "failing stop" due to out of disk space?
99 */
100int audit_in_failure;
101
102/*
103 * Global audit statistiscs.
104 */
105struct audit_fstat audit_fstat;
106
107/*
108 * Preselection mask for non-attributable events.
109 */
110struct au_mask audit_nae_mask;
111
112/*
113 * Mutex to protect global variables shared between various threads and
114 * processes.
115 */
116struct mtx audit_mtx;
117
118/*
119 * Queue of audit records ready for delivery to disk. We insert new
120 * records at the tail, and remove records from the head. Also,
121 * a count of the number of records used for checking queue depth.
122 * In addition, a counter of records that we have allocated but are
123 * not yet in the queue, which is needed to estimate the total
124 * size of the combined set of records outstanding in the system.
125 */
126struct kaudit_queue audit_q;
127int audit_q_len;
128int audit_pre_q_len;
129
130/*
131 * Audit queue control settings (minimum free, low/high water marks, etc.)
132 */
133struct au_qctrl audit_qctrl;
134
135/*
136 * Condition variable to signal to the worker that it has work to do:
137 * either new records are in the queue, or a log replacement is taking
138 * place.
139 */
140struct cv audit_worker_cv;
141
142/*
143 * Condition variable to flag when crossing the low watermark, meaning that
144 * threads blocked due to hitting the high watermark can wake up and continue
145 * to commit records.
146 */
147struct cv audit_watermark_cv;
148
149/*
150 * Condition variable for auditing threads wait on when in fail-stop mode.
151 * Threads wait on this CV forever (and ever), never seeing the light of
152 * day again.
153 */
154static struct cv audit_fail_cv;
155
156/*
157 * Construct an audit record for the passed thread.
158 */
159static int
160audit_record_ctor(void *mem, int size, void *arg, int flags)
161{
162 struct kaudit_record *ar;
163 struct thread *td;
164
165 KASSERT(sizeof(*ar) == size, ("audit_record_ctor: wrong size"));
166
167 td = arg;
168 ar = mem;
169 bzero(ar, sizeof(*ar));
170 ar->k_ar.ar_magic = AUDIT_RECORD_MAGIC;
171 nanotime(&ar->k_ar.ar_starttime);
172
173 /*
174 * Export the subject credential.
175 */
176 cru2x(td->td_ucred, &ar->k_ar.ar_subj_cred);
177 ar->k_ar.ar_subj_ruid = td->td_ucred->cr_ruid;
178 ar->k_ar.ar_subj_rgid = td->td_ucred->cr_rgid;
179 ar->k_ar.ar_subj_egid = td->td_ucred->cr_groups[0];
180 PROC_LOCK(td->td_proc);
181 ar->k_ar.ar_subj_auid = td->td_proc->p_au->ai_auid;
182 ar->k_ar.ar_subj_asid = td->td_proc->p_au->ai_asid;
183 ar->k_ar.ar_subj_pid = td->td_proc->p_pid;
184 ar->k_ar.ar_subj_amask = td->td_proc->p_au->ai_mask;
185 ar->k_ar.ar_subj_term = td->td_proc->p_au->ai_termid;
186 bcopy(td->td_proc->p_comm, ar->k_ar.ar_subj_comm, MAXCOMLEN);
187 PROC_UNLOCK(td->td_proc);
188
189 return (0);
190}
191
192static void
193audit_record_dtor(void *mem, int size, void *arg)
194{
195 struct kaudit_record *ar;
196
197 KASSERT(sizeof(*ar) == size, ("audit_record_dtor: wrong size"));
198
199 ar = mem;
200 if (ar->k_ar.ar_arg_upath1 != NULL)
201 free(ar->k_ar.ar_arg_upath1, M_AUDITPATH);
202 if (ar->k_ar.ar_arg_upath2 != NULL)
203 free(ar->k_ar.ar_arg_upath2, M_AUDITPATH);
204 if (ar->k_ar.ar_arg_text != NULL)
205 free(ar->k_ar.ar_arg_text, M_AUDITTEXT);
206 if (ar->k_udata != NULL)
207 free(ar->k_udata, M_AUDITDATA);
208 if (ar->k_ar.ar_arg_argv != NULL)
209 free(ar->k_ar.ar_arg_argv, M_AUDITTEXT);
210 if (ar->k_ar.ar_arg_envv != NULL)
211 free(ar->k_ar.ar_arg_envv, M_AUDITTEXT);
212}
213
214/*
215 * Initialize the Audit subsystem: configuration state, work queue,
216 * synchronization primitives, worker thread, and trigger device node. Also
217 * call into the BSM assembly code to initialize it.
218 */
219static void
220audit_init(void)
221{
222
223 printf("Security auditing service present\n");
224 audit_enabled = 0;
225 audit_suspended = 0;
226 audit_panic_on_write_fail = 0;
227 audit_fail_stop = 0;
228 audit_in_failure = 0;
229 audit_argv = 0;
230 audit_arge = 0;
231
232 audit_fstat.af_filesz = 0; /* '0' means unset, unbounded */
233 audit_fstat.af_currsz = 0;
234 audit_nae_mask.am_success = AU_NULL;
235 audit_nae_mask.am_failure = AU_NULL;
236
237 TAILQ_INIT(&audit_q);
238 audit_q_len = 0;
239 audit_pre_q_len = 0;
240 audit_qctrl.aq_hiwater = AQ_HIWATER;
241 audit_qctrl.aq_lowater = AQ_LOWATER;
242 audit_qctrl.aq_bufsz = AQ_BUFSZ;
243 audit_qctrl.aq_minfree = AU_FS_MINFREE;
244
245 mtx_init(&audit_mtx, "audit_mtx", NULL, MTX_DEF);
246 cv_init(&audit_worker_cv, "audit_worker_cv");
247 cv_init(&audit_watermark_cv, "audit_watermark_cv");
248 cv_init(&audit_fail_cv, "audit_fail_cv");
249
250 audit_record_zone = uma_zcreate("audit_record",
251 sizeof(struct kaudit_record), audit_record_ctor,
252 audit_record_dtor, NULL, NULL, UMA_ALIGN_PTR, 0);
253
254 /* Initialize the BSM audit subsystem. */
255 kau_init();
256
257 audit_trigger_init();
258
259 /* Register shutdown handler. */
260 EVENTHANDLER_REGISTER(shutdown_pre_sync, audit_shutdown, NULL,
261 SHUTDOWN_PRI_FIRST);
262
263 /* Start audit worker thread. */
264 audit_worker_init();
265}
266
267SYSINIT(audit_init, SI_SUB_AUDIT, SI_ORDER_FIRST, audit_init, NULL)
268
269/*
270 * Drain the audit queue and close the log at shutdown. Note that this can
271 * be called both from the system shutdown path and also from audit
272 * configuration syscalls, so 'arg' and 'howto' are ignored.
273 */
274void
275audit_shutdown(void *arg, int howto)
276{
277
278 audit_rotate_vnode(NULL, NULL);
279}
280
281/*
282 * Return the current thread's audit record, if any.
283 */
284__inline__ struct kaudit_record *
285currecord(void)
286{
287
288 return (curthread->td_ar);
289}
290
291/*
292 * MPSAFE
293 *
294 * XXXAUDIT: There are a number of races present in the code below due to
295 * release and re-grab of the mutex. The code should be revised to become
296 * slightly less racy.
297 *
298 * XXXAUDIT: Shouldn't there be logic here to sleep waiting on available
299 * pre_q space, suspending the system call until there is room?
300 */
301struct kaudit_record *
302audit_new(int event, struct thread *td)
303{
304 struct kaudit_record *ar;
305 int no_record;
306
307 mtx_lock(&audit_mtx);
308 no_record = (audit_suspended || !audit_enabled);
309 mtx_unlock(&audit_mtx);
310 if (no_record)
311 return (NULL);
312
313 /*
314 * XXX: The number of outstanding uncommitted audit records is
315 * limited to the number of concurrent threads servicing system
316 * calls in the kernel.
317 */
318 ar = uma_zalloc_arg(audit_record_zone, td, M_WAITOK);
319 ar->k_ar.ar_event = event;
320
321 mtx_lock(&audit_mtx);
322 audit_pre_q_len++;
323 mtx_unlock(&audit_mtx);
324
325 return (ar);
326}
327
328void
329audit_free(struct kaudit_record *ar)
330{
331
332 uma_zfree(audit_record_zone, ar);
333}
334
335/*
336 * MPSAFE
337 */
338void
339audit_commit(struct kaudit_record *ar, int error, int retval)
340{
341 au_event_t event;
342 au_class_t class;
343 au_id_t auid;
344 int sorf;
345 struct au_mask *aumask;
346
347 if (ar == NULL)
348 return;
349
350 /*
351 * Decide whether to commit the audit record by checking the
352 * error value from the system call and using the appropriate
353 * audit mask.
354 *
355 * XXXAUDIT: Synchronize access to audit_nae_mask?
356 */
357 if (ar->k_ar.ar_subj_auid == AU_DEFAUDITID)
358 aumask = &audit_nae_mask;
359 else
360 aumask = &ar->k_ar.ar_subj_amask;
361
362 if (error)
363 sorf = AU_PRS_FAILURE;
364 else
365 sorf = AU_PRS_SUCCESS;
366
367 switch(ar->k_ar.ar_event) {
368
369 case AUE_OPEN_RWTC:
370 /* The open syscall always writes a AUE_OPEN_RWTC event; change
371 * it to the proper type of event based on the flags and the
372 * error value.
373 */
374 ar->k_ar.ar_event = flags_and_error_to_openevent(
375 ar->k_ar.ar_arg_fflags, error);
376 break;
377
378 case AUE_SYSCTL:
379 ar->k_ar.ar_event = ctlname_to_sysctlevent(
380 ar->k_ar.ar_arg_ctlname, ar->k_ar.ar_valid_arg);
381 break;
382
383 case AUE_AUDITON:
384 /* Convert the auditon() command to an event */
385 ar->k_ar.ar_event = auditon_command_event(ar->k_ar.ar_arg_cmd);
386 break;
387 }
388
389 auid = ar->k_ar.ar_subj_auid;
390 event = ar->k_ar.ar_event;
391 class = au_event_class(event);
392
393 ar->k_ar_commit |= AR_COMMIT_KERNEL;
394 if (au_preselect(event, class, aumask, sorf) != 0)
395 ar->k_ar_commit |= AR_PRESELECT_TRAIL;
396 if (audit_pipe_preselect(auid, event, class, sorf,
397 ar->k_ar_commit & AR_PRESELECT_TRAIL) != 0)
398 ar->k_ar_commit |= AR_PRESELECT_PIPE;
|
399 if ((ar->k_ar_commit & (AR_PRESELECT_TRAIL | AR_PRESELECT_PIPE)) ==
400 0) {
| 399 if ((ar->k_ar_commit & (AR_PRESELECT_TRAIL | AR_PRESELECT_PIPE |
400 AR_PRESELECT_USER_TRAIL | AR_PRESELECT_USER_PIPE)) == 0) {
|
401 mtx_lock(&audit_mtx);
402 audit_pre_q_len--;
403 mtx_unlock(&audit_mtx);
404 audit_free(ar);
405 return;
406 }
407
408 ar->k_ar.ar_errno = error;
409 ar->k_ar.ar_retval = retval;
410
411 /*
412 * We might want to do some system-wide post-filtering
413 * here at some point.
414 */
415
416 /*
417 * Timestamp system call end.
418 */
419 nanotime(&ar->k_ar.ar_endtime);
420
421 mtx_lock(&audit_mtx);
422
423 /*
424 * Note: it could be that some records initiated while audit was
425 * enabled should still be committed?
426 */
427 if (audit_suspended || !audit_enabled) {
428 audit_pre_q_len--;
429 mtx_unlock(&audit_mtx);
430 audit_free(ar);
431 return;
432 }
433
434 /*
435 * Constrain the number of committed audit records based on
436 * the configurable parameter.
437 */
438 while (audit_q_len >= audit_qctrl.aq_hiwater) {
439 AUDIT_PRINTF(("audit_commit: sleeping to wait for "
440 "audit queue to drain below high water mark\n"));
441 cv_wait(&audit_watermark_cv, &audit_mtx);
442 AUDIT_PRINTF(("audit_commit: woke up waiting for "
443 "audit queue draining\n"));
444 }
445
446 TAILQ_INSERT_TAIL(&audit_q, ar, k_q);
447 audit_q_len++;
448 audit_pre_q_len--;
449 cv_signal(&audit_worker_cv);
450 mtx_unlock(&audit_mtx);
451}
452
453/*
454 * audit_syscall_enter() is called on entry to each system call. It is
455 * responsible for deciding whether or not to audit the call (preselection),
456 * and if so, allocating a per-thread audit record. audit_new() will fill in
457 * basic thread/credential properties.
458 */
459void
460audit_syscall_enter(unsigned short code, struct thread *td)
461{
462 struct au_mask *aumask;
463 au_class_t class;
464 au_event_t event;
465 au_id_t auid;
466
467 KASSERT(td->td_ar == NULL, ("audit_syscall_enter: td->td_ar != NULL"));
468
469 /*
470 * In FreeBSD, each ABI has its own system call table, and hence
471 * mapping of system call codes to audit events. Convert the code to
472 * an audit event identifier using the process system call table
473 * reference. In Darwin, there's only one, so we use the global
474 * symbol for the system call table.
475 *
476 * XXXAUDIT: Should we audit that a bad system call was made, and if
477 * so, how?
478 */
479 if (code >= td->td_proc->p_sysent->sv_size)
480 return;
481
482 event = td->td_proc->p_sysent->sv_table[code].sy_auevent;
483 if (event == AUE_NULL)
484 return;
485
486 /*
487 * Check which audit mask to use; either the kernel non-attributable
488 * event mask or the process audit mask.
489 */
490 auid = td->td_proc->p_au->ai_auid;
491 if (auid == AU_DEFAUDITID)
492 aumask = &audit_nae_mask;
493 else
494 aumask = &td->td_proc->p_au->ai_mask;
495
496 /*
497 * Allocate an audit record, if preselection allows it, and store
498 * in the thread for later use.
499 */
500 class = au_event_class(event);
501 if (au_preselect(event, class, aumask, AU_PRS_BOTH)) {
502 /*
503 * If we're out of space and need to suspend unprivileged
504 * processes, do that here rather than trying to allocate
505 * another audit record.
506 *
507 * XXXRW: We might wish to be able to continue here in the
508 * future, if the system recovers. That should be possible
509 * by means of checking the condition in a loop around
510 * cv_wait(). It might be desirable to reevaluate whether an
511 * audit record is still required for this event by
512 * re-calling au_preselect().
513 */
514 if (audit_in_failure && suser(td) != 0) {
515 cv_wait(&audit_fail_cv, &audit_mtx);
516 panic("audit_failing_stop: thread continued");
517 }
518 td->td_ar = audit_new(event, td);
519 } else if (audit_pipe_preselect(auid, event, class, AU_PRS_BOTH, 0))
520 td->td_ar = audit_new(event, td);
521 else
522 td->td_ar = NULL;
523}
524
525/*
526 * audit_syscall_exit() is called from the return of every system call, or in
527 * the event of exit1(), during the execution of exit1(). It is responsible
528 * for committing the audit record, if any, along with return condition.
529 */
530void
531audit_syscall_exit(int error, struct thread *td)
532{
533 int retval;
534
535 /*
536 * Commit the audit record as desired; once we pass the record
537 * into audit_commit(), the memory is owned by the audit
538 * subsystem.
539 * The return value from the system call is stored on the user
540 * thread. If there was an error, the return value is set to -1,
541 * imitating the behavior of the cerror routine.
542 */
543 if (error)
544 retval = -1;
545 else
546 retval = td->td_retval[0];
547
548 audit_commit(td->td_ar, error, retval);
549 if (td->td_ar != NULL)
550 AUDIT_PRINTF(("audit record committed by pid %d\n",
551 td->td_proc->p_pid));
552 td->td_ar = NULL;
553
554}
555
556/*
557 * Allocate storage for a new process (init, or otherwise).
558 */
559void
560audit_proc_alloc(struct proc *p)
561{
562
563 KASSERT(p->p_au == NULL, ("audit_proc_alloc: p->p_au != NULL (%d)",
564 p->p_pid));
565 p->p_au = malloc(sizeof(*(p->p_au)), M_AUDITPROC, M_WAITOK);
566 /* XXXAUDIT: Zero? Slab allocate? */
567 //printf("audit_proc_alloc: pid %d p_au %p\n", p->p_pid, p->p_au);
568}
569
570/*
571 * Allocate storage for a new thread.
572 */
573void
574audit_thread_alloc(struct thread *td)
575{
576
577 td->td_ar = NULL;
578}
579
580/*
581 * Thread destruction.
582 */
583void
584audit_thread_free(struct thread *td)
585{
586
587 KASSERT(td->td_ar == NULL, ("audit_thread_free: td_ar != NULL"));
588}
589
590/*
591 * Initialize the audit information for the a process, presumably the first
592 * process in the system.
593 * XXX It is not clear what the initial values should be for audit ID,
594 * session ID, etc.
595 */
596void
597audit_proc_kproc0(struct proc *p)
598{
599
600 KASSERT(p->p_au != NULL, ("audit_proc_kproc0: p->p_au == NULL (%d)",
601 p->p_pid));
602 //printf("audit_proc_kproc0: pid %d p_au %p\n", p->p_pid, p->p_au);
603 bzero(p->p_au, sizeof(*(p)->p_au));
604}
605
606void
607audit_proc_init(struct proc *p)
608{
609
610 KASSERT(p->p_au != NULL, ("audit_proc_init: p->p_au == NULL (%d)",
611 p->p_pid));
612 //printf("audit_proc_init: pid %d p_au %p\n", p->p_pid, p->p_au);
613 bzero(p->p_au, sizeof(*(p)->p_au));
614 p->p_au->ai_auid = AU_DEFAUDITID;
615}
616
617/*
618 * Copy the audit info from the parent process to the child process when
619 * a fork takes place.
620 */
621void
622audit_proc_fork(struct proc *parent, struct proc *child)
623{
624
625 PROC_LOCK_ASSERT(parent, MA_OWNED);
626 PROC_LOCK_ASSERT(child, MA_OWNED);
627 KASSERT(parent->p_au != NULL,
628 ("audit_proc_fork: parent->p_au == NULL (%d)", parent->p_pid));
629 KASSERT(child->p_au != NULL,
630 ("audit_proc_fork: child->p_au == NULL (%d)", child->p_pid));
631 //printf("audit_proc_fork: parent pid %d p_au %p\n", parent->p_pid,
632 // parent->p_au);
633 //printf("audit_proc_fork: child pid %d p_au %p\n", child->p_pid,
634 // child->p_au);
635 bcopy(parent->p_au, child->p_au, sizeof(*child->p_au));
636 /*
637 * XXXAUDIT: Zero pointers to external memory, or assert they are
638 * zero?
639 */
640}
641
642/*
643 * Free the auditing structure for the process.
644 */
645void
646audit_proc_free(struct proc *p)
647{
648
649 KASSERT(p->p_au != NULL, ("p->p_au == NULL (%d)", p->p_pid));
650 //printf("audit_proc_free: pid %d p_au %p\n", p->p_pid, p->p_au);
651 /*
652 * XXXAUDIT: Assert that external memory pointers are NULL?
653 */
654 free(p->p_au, M_AUDITPROC);
655 p->p_au = NULL;
656}
| 401 mtx_lock(&audit_mtx);
402 audit_pre_q_len--;
403 mtx_unlock(&audit_mtx);
404 audit_free(ar);
405 return;
406 }
407
408 ar->k_ar.ar_errno = error;
409 ar->k_ar.ar_retval = retval;
410
411 /*
412 * We might want to do some system-wide post-filtering
413 * here at some point.
414 */
415
416 /*
417 * Timestamp system call end.
418 */
419 nanotime(&ar->k_ar.ar_endtime);
420
421 mtx_lock(&audit_mtx);
422
423 /*
424 * Note: it could be that some records initiated while audit was
425 * enabled should still be committed?
426 */
427 if (audit_suspended || !audit_enabled) {
428 audit_pre_q_len--;
429 mtx_unlock(&audit_mtx);
430 audit_free(ar);
431 return;
432 }
433
434 /*
435 * Constrain the number of committed audit records based on
436 * the configurable parameter.
437 */
438 while (audit_q_len >= audit_qctrl.aq_hiwater) {
439 AUDIT_PRINTF(("audit_commit: sleeping to wait for "
440 "audit queue to drain below high water mark\n"));
441 cv_wait(&audit_watermark_cv, &audit_mtx);
442 AUDIT_PRINTF(("audit_commit: woke up waiting for "
443 "audit queue draining\n"));
444 }
445
446 TAILQ_INSERT_TAIL(&audit_q, ar, k_q);
447 audit_q_len++;
448 audit_pre_q_len--;
449 cv_signal(&audit_worker_cv);
450 mtx_unlock(&audit_mtx);
451}
452
453/*
454 * audit_syscall_enter() is called on entry to each system call. It is
455 * responsible for deciding whether or not to audit the call (preselection),
456 * and if so, allocating a per-thread audit record. audit_new() will fill in
457 * basic thread/credential properties.
458 */
459void
460audit_syscall_enter(unsigned short code, struct thread *td)
461{
462 struct au_mask *aumask;
463 au_class_t class;
464 au_event_t event;
465 au_id_t auid;
466
467 KASSERT(td->td_ar == NULL, ("audit_syscall_enter: td->td_ar != NULL"));
468
469 /*
470 * In FreeBSD, each ABI has its own system call table, and hence
471 * mapping of system call codes to audit events. Convert the code to
472 * an audit event identifier using the process system call table
473 * reference. In Darwin, there's only one, so we use the global
474 * symbol for the system call table.
475 *
476 * XXXAUDIT: Should we audit that a bad system call was made, and if
477 * so, how?
478 */
479 if (code >= td->td_proc->p_sysent->sv_size)
480 return;
481
482 event = td->td_proc->p_sysent->sv_table[code].sy_auevent;
483 if (event == AUE_NULL)
484 return;
485
486 /*
487 * Check which audit mask to use; either the kernel non-attributable
488 * event mask or the process audit mask.
489 */
490 auid = td->td_proc->p_au->ai_auid;
491 if (auid == AU_DEFAUDITID)
492 aumask = &audit_nae_mask;
493 else
494 aumask = &td->td_proc->p_au->ai_mask;
495
496 /*
497 * Allocate an audit record, if preselection allows it, and store
498 * in the thread for later use.
499 */
500 class = au_event_class(event);
501 if (au_preselect(event, class, aumask, AU_PRS_BOTH)) {
502 /*
503 * If we're out of space and need to suspend unprivileged
504 * processes, do that here rather than trying to allocate
505 * another audit record.
506 *
507 * XXXRW: We might wish to be able to continue here in the
508 * future, if the system recovers. That should be possible
509 * by means of checking the condition in a loop around
510 * cv_wait(). It might be desirable to reevaluate whether an
511 * audit record is still required for this event by
512 * re-calling au_preselect().
513 */
514 if (audit_in_failure && suser(td) != 0) {
515 cv_wait(&audit_fail_cv, &audit_mtx);
516 panic("audit_failing_stop: thread continued");
517 }
518 td->td_ar = audit_new(event, td);
519 } else if (audit_pipe_preselect(auid, event, class, AU_PRS_BOTH, 0))
520 td->td_ar = audit_new(event, td);
521 else
522 td->td_ar = NULL;
523}
524
525/*
526 * audit_syscall_exit() is called from the return of every system call, or in
527 * the event of exit1(), during the execution of exit1(). It is responsible
528 * for committing the audit record, if any, along with return condition.
529 */
530void
531audit_syscall_exit(int error, struct thread *td)
532{
533 int retval;
534
535 /*
536 * Commit the audit record as desired; once we pass the record
537 * into audit_commit(), the memory is owned by the audit
538 * subsystem.
539 * The return value from the system call is stored on the user
540 * thread. If there was an error, the return value is set to -1,
541 * imitating the behavior of the cerror routine.
542 */
543 if (error)
544 retval = -1;
545 else
546 retval = td->td_retval[0];
547
548 audit_commit(td->td_ar, error, retval);
549 if (td->td_ar != NULL)
550 AUDIT_PRINTF(("audit record committed by pid %d\n",
551 td->td_proc->p_pid));
552 td->td_ar = NULL;
553
554}
555
556/*
557 * Allocate storage for a new process (init, or otherwise).
558 */
559void
560audit_proc_alloc(struct proc *p)
561{
562
563 KASSERT(p->p_au == NULL, ("audit_proc_alloc: p->p_au != NULL (%d)",
564 p->p_pid));
565 p->p_au = malloc(sizeof(*(p->p_au)), M_AUDITPROC, M_WAITOK);
566 /* XXXAUDIT: Zero? Slab allocate? */
567 //printf("audit_proc_alloc: pid %d p_au %p\n", p->p_pid, p->p_au);
568}
569
570/*
571 * Allocate storage for a new thread.
572 */
573void
574audit_thread_alloc(struct thread *td)
575{
576
577 td->td_ar = NULL;
578}
579
580/*
581 * Thread destruction.
582 */
583void
584audit_thread_free(struct thread *td)
585{
586
587 KASSERT(td->td_ar == NULL, ("audit_thread_free: td_ar != NULL"));
588}
589
590/*
591 * Initialize the audit information for the a process, presumably the first
592 * process in the system.
593 * XXX It is not clear what the initial values should be for audit ID,
594 * session ID, etc.
595 */
596void
597audit_proc_kproc0(struct proc *p)
598{
599
600 KASSERT(p->p_au != NULL, ("audit_proc_kproc0: p->p_au == NULL (%d)",
601 p->p_pid));
602 //printf("audit_proc_kproc0: pid %d p_au %p\n", p->p_pid, p->p_au);
603 bzero(p->p_au, sizeof(*(p)->p_au));
604}
605
606void
607audit_proc_init(struct proc *p)
608{
609
610 KASSERT(p->p_au != NULL, ("audit_proc_init: p->p_au == NULL (%d)",
611 p->p_pid));
612 //printf("audit_proc_init: pid %d p_au %p\n", p->p_pid, p->p_au);
613 bzero(p->p_au, sizeof(*(p)->p_au));
614 p->p_au->ai_auid = AU_DEFAUDITID;
615}
616
617/*
618 * Copy the audit info from the parent process to the child process when
619 * a fork takes place.
620 */
621void
622audit_proc_fork(struct proc *parent, struct proc *child)
623{
624
625 PROC_LOCK_ASSERT(parent, MA_OWNED);
626 PROC_LOCK_ASSERT(child, MA_OWNED);
627 KASSERT(parent->p_au != NULL,
628 ("audit_proc_fork: parent->p_au == NULL (%d)", parent->p_pid));
629 KASSERT(child->p_au != NULL,
630 ("audit_proc_fork: child->p_au == NULL (%d)", child->p_pid));
631 //printf("audit_proc_fork: parent pid %d p_au %p\n", parent->p_pid,
632 // parent->p_au);
633 //printf("audit_proc_fork: child pid %d p_au %p\n", child->p_pid,
634 // child->p_au);
635 bcopy(parent->p_au, child->p_au, sizeof(*child->p_au));
636 /*
637 * XXXAUDIT: Zero pointers to external memory, or assert they are
638 * zero?
639 */
640}
641
642/*
643 * Free the auditing structure for the process.
644 */
645void
646audit_proc_free(struct proc *p)
647{
648
649 KASSERT(p->p_au != NULL, ("p->p_au == NULL (%d)", p->p_pid));
650 //printf("audit_proc_free: pid %d p_au %p\n", p->p_pid, p->p_au);
651 /*
652 * XXXAUDIT: Assert that external memory pointers are NULL?
653 */
654 free(p->p_au, M_AUDITPROC);
655 p->p_au = NULL;
656}
|