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_worker.c 159265 2006-06-05 14:09:59Z rwatson $
| 30 * $FreeBSD: head/sys/security/audit/audit_worker.c 159269 2006-06-05 14:48:17Z rwatson $
|
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
72/*
73 * Worker thread that will schedule disk I/O, etc.
74 */
75static struct proc *audit_thread;
76
77/*
78 * When an audit log is rotated, the actual rotation must be performed by the
79 * audit worker thread, as it may have outstanding writes on the current
80 * audit log. audit_replacement_vp holds the vnode replacing the current
81 * vnode. We can't let more than one replacement occur at a time, so if more
82 * than one thread requests a replacement, only one can have the replacement
83 * "in progress" at any given moment. If a thread tries to replace the audit
84 * vnode and discovers a replacement is already in progress (i.e.,
85 * audit_replacement_flag != 0), then it will sleep on audit_replacement_cv
86 * waiting its turn to perform a replacement. When a replacement is
87 * completed, this cv is signalled by the worker thread so a waiting thread
88 * can start another replacement. We also store a credential to perform
89 * audit log write operations with.
90 *
91 * The current credential and vnode are thread-local to audit_worker.
92 */
93static struct cv audit_replacement_cv;
94
95static int audit_replacement_flag;
96static struct vnode *audit_replacement_vp;
97static struct ucred *audit_replacement_cred;
98
99/*
100 * Flags related to Kernel->user-space communication.
101 */
102static int audit_file_rotate_wait;
103
104/*
105 * XXXAUDIT: Should adjust comments below to make it clear that we get to
106 * this point only if we believe we have storage, so not having space here is
107 * a violation of invariants derived from administrative procedures. I.e.,
108 * someone else has written to the audit partition, leaving less space than
109 * we accounted for.
110 */
111static int
112audit_record_write(struct vnode *vp, struct ucred *cred, struct thread *td,
113 void *data, size_t len)
114{
115 int ret;
116 long temp;
117 struct vattr vattr;
118 struct statfs *mnt_stat = &vp->v_mount->mnt_stat;
119 int vfslocked;
120
121 if (vp == NULL)
122 return (0);
123
124 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
125
126 /*
127 * First, gather statistics on the audit log file and file system so
128 * that we know how we're doing on space. In both cases, if we're
129 * unable to perform the operation, we drop the record and return.
130 * However, this is arguably an assertion failure.
131 * XXX Need a FreeBSD equivalent.
132 */
133 ret = VFS_STATFS(vp->v_mount, mnt_stat, td);
134 if (ret)
135 goto out;
136
137 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
138 ret = VOP_GETATTR(vp, &vattr, cred, td);
139 VOP_UNLOCK(vp, 0, td);
140 if (ret)
141 goto out;
142
143 /* update the global stats struct */
144 audit_fstat.af_currsz = vattr.va_size;
145
146 /*
147 * XXX Need to decide what to do if the trigger to the audit daemon
148 * fails.
149 */
150
151 /*
152 * If we fall below minimum free blocks (hard limit), tell the audit
153 * daemon to force a rotation off of the file system. We also stop
154 * writing, which means this audit record is probably lost. If we
155 * fall below the minimum percent free blocks (soft limit), then
156 * kindly suggest to the audit daemon to do something.
157 */
158 if (mnt_stat->f_bfree < AUDIT_HARD_LIMIT_FREE_BLOCKS) {
159 (void)send_trigger(AUDIT_TRIGGER_NO_SPACE);
160 /*
161 * Hopefully userspace did something about all the previous
162 * triggers that were sent prior to this critical condition.
163 * If fail-stop is set, then we're done; goodnight Gracie.
164 */
165 if (audit_fail_stop)
166 panic("Audit log space exhausted and fail-stop set.");
167 else {
168 audit_suspended = 1;
169 ret = ENOSPC;
170 goto out;
171 }
172 } else
173 /*
174 * Send a message to the audit daemon that disk space is
175 * getting low.
176 *
177 * XXXAUDIT: Check math and block size calculation here.
178 */
179 if (audit_qctrl.aq_minfree != 0) {
180 temp = mnt_stat->f_blocks / (100 /
181 audit_qctrl.aq_minfree);
182 if (mnt_stat->f_bfree < temp)
183 (void)send_trigger(AUDIT_TRIGGER_LOW_SPACE);
184 }
185
186 /*
187 * Check if the current log file is full; if so, call for a log
188 * rotate. This is not an exact comparison; we may write some records
189 * over the limit. If that's not acceptable, then add a fudge factor
190 * here.
191 */
192 if ((audit_fstat.af_filesz != 0) &&
193 (audit_file_rotate_wait == 0) &&
194 (vattr.va_size >= audit_fstat.af_filesz)) {
195 audit_file_rotate_wait = 1;
196 (void)send_trigger(AUDIT_TRIGGER_OPEN_NEW);
197 }
198
199 /*
200 * If the estimated amount of audit data in the audit event queue
201 * (plus records allocated but not yet queued) has reached the amount
202 * of free space on the disk, then we need to go into an audit fail
203 * stop state, in which we do not permit the allocation/committing of
204 * any new audit records. We continue to process packets but don't
205 * allow any activities that might generate new records. In the
206 * future, we might want to detect when space is available again and
207 * allow operation to continue, but this behavior is sufficient to
208 * meet fail stop requirements in CAPP.
209 */
210 if (audit_fail_stop &&
211 (unsigned long)
212 ((audit_q_len + audit_pre_q_len + 1) * MAX_AUDIT_RECORD_SIZE) /
213 mnt_stat->f_bsize >= (unsigned long)(mnt_stat->f_bfree)) {
214 printf("audit_record_write: free space below size of audit "
215 "queue, failing stop\n");
216 audit_in_failure = 1;
217 }
218
219 ret = vn_rdwr(UIO_WRITE, vp, data, len, (off_t)0, UIO_SYSSPACE,
220 IO_APPEND|IO_UNIT, cred, NULL, NULL, td);
221
222out:
223 /*
224 * When we're done processing the current record, we have to check to
225 * see if we're in a failure mode, and if so, whether this was the
226 * last record left to be drained. If we're done draining, then we
227 * fsync the vnode and panic.
228 */
229 if (audit_in_failure && audit_q_len == 0 && audit_pre_q_len == 0) {
230 VOP_LOCK(vp, LK_DRAIN | LK_INTERLOCK, td);
231 (void)VOP_FSYNC(vp, MNT_WAIT, td);
232 VOP_UNLOCK(vp, 0, td);
233 panic("Audit store overflow; record queue drained.");
234 }
235
236 VFS_UNLOCK_GIANT(vfslocked);
237
238 return (ret);
239}
240
241/*
242 * If an appropriate signal has been received rotate the audit log based on
243 * the global replacement variables. Signal consumers as needed that the
244 * rotation has taken place.
245 *
246 * XXXRW: The global variables and CVs used to signal the audit_worker to
247 * perform a rotation are essentially a message queue of depth 1. It would
248 * be much nicer to actually use a message queue.
249 */
250static void
251audit_worker_rotate(struct ucred **audit_credp, struct vnode **audit_vpp,
252 struct thread *audit_td)
253{
254 int do_replacement_signal, vfslocked;
255 struct ucred *old_cred;
256 struct vnode *old_vp;
257
258 mtx_assert(&audit_mtx, MA_OWNED);
259
260 do_replacement_signal = 0;
261 while (audit_replacement_flag != 0) {
262 old_cred = *audit_credp;
263 old_vp = *audit_vpp;
264 *audit_credp = audit_replacement_cred;
265 *audit_vpp = audit_replacement_vp;
266 audit_replacement_cred = NULL;
267 audit_replacement_vp = NULL;
268 audit_replacement_flag = 0;
269
270 audit_enabled = (*audit_vpp != NULL);
271
272 /*
273 * XXX: What to do about write failures here?
274 */
275 if (old_vp != NULL) {
276 AUDIT_PRINTF(("Closing old audit file\n"));
277 mtx_unlock(&audit_mtx);
278 vfslocked = VFS_LOCK_GIANT(old_vp->v_mount);
279 vn_close(old_vp, AUDIT_CLOSE_FLAGS, old_cred,
280 audit_td);
281 VFS_UNLOCK_GIANT(vfslocked);
282 crfree(old_cred);
283 mtx_lock(&audit_mtx);
284 old_cred = NULL;
285 old_vp = NULL;
286 AUDIT_PRINTF(("Audit file closed\n"));
287 }
288 if (*audit_vpp != NULL) {
289 AUDIT_PRINTF(("Opening new audit file\n"));
290 }
291 do_replacement_signal = 1;
292 }
293
294 /*
295 * Signal that replacement have occurred to wake up and
296 * start any other replacements started in parallel. We can
297 * continue about our business in the mean time. We
298 * broadcast so that both new replacements can be inserted,
299 * but also so that the source(s) of replacement can return
300 * successfully.
301 */
302 if (do_replacement_signal)
303 cv_broadcast(&audit_replacement_cv);
304}
305
306/*
307 * Given a kernel audit record, process as required. Kernel audit records
308 * are converted to one, or possibly two, BSM records, depending on whether
309 * there is a user audit record present also. Kernel records need be
310 * converted to BSM before they can be written out. Both types will be
311 * written to disk, and audit pipes.
312 */
313static void
314audit_worker_process_record(struct vnode *audit_vp, struct ucred *audit_cred,
315 struct thread *audit_td, struct kaudit_record *ar)
316{
317 struct au_record *bsm;
| 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
72/*
73 * Worker thread that will schedule disk I/O, etc.
74 */
75static struct proc *audit_thread;
76
77/*
78 * When an audit log is rotated, the actual rotation must be performed by the
79 * audit worker thread, as it may have outstanding writes on the current
80 * audit log. audit_replacement_vp holds the vnode replacing the current
81 * vnode. We can't let more than one replacement occur at a time, so if more
82 * than one thread requests a replacement, only one can have the replacement
83 * "in progress" at any given moment. If a thread tries to replace the audit
84 * vnode and discovers a replacement is already in progress (i.e.,
85 * audit_replacement_flag != 0), then it will sleep on audit_replacement_cv
86 * waiting its turn to perform a replacement. When a replacement is
87 * completed, this cv is signalled by the worker thread so a waiting thread
88 * can start another replacement. We also store a credential to perform
89 * audit log write operations with.
90 *
91 * The current credential and vnode are thread-local to audit_worker.
92 */
93static struct cv audit_replacement_cv;
94
95static int audit_replacement_flag;
96static struct vnode *audit_replacement_vp;
97static struct ucred *audit_replacement_cred;
98
99/*
100 * Flags related to Kernel->user-space communication.
101 */
102static int audit_file_rotate_wait;
103
104/*
105 * XXXAUDIT: Should adjust comments below to make it clear that we get to
106 * this point only if we believe we have storage, so not having space here is
107 * a violation of invariants derived from administrative procedures. I.e.,
108 * someone else has written to the audit partition, leaving less space than
109 * we accounted for.
110 */
111static int
112audit_record_write(struct vnode *vp, struct ucred *cred, struct thread *td,
113 void *data, size_t len)
114{
115 int ret;
116 long temp;
117 struct vattr vattr;
118 struct statfs *mnt_stat = &vp->v_mount->mnt_stat;
119 int vfslocked;
120
121 if (vp == NULL)
122 return (0);
123
124 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
125
126 /*
127 * First, gather statistics on the audit log file and file system so
128 * that we know how we're doing on space. In both cases, if we're
129 * unable to perform the operation, we drop the record and return.
130 * However, this is arguably an assertion failure.
131 * XXX Need a FreeBSD equivalent.
132 */
133 ret = VFS_STATFS(vp->v_mount, mnt_stat, td);
134 if (ret)
135 goto out;
136
137 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
138 ret = VOP_GETATTR(vp, &vattr, cred, td);
139 VOP_UNLOCK(vp, 0, td);
140 if (ret)
141 goto out;
142
143 /* update the global stats struct */
144 audit_fstat.af_currsz = vattr.va_size;
145
146 /*
147 * XXX Need to decide what to do if the trigger to the audit daemon
148 * fails.
149 */
150
151 /*
152 * If we fall below minimum free blocks (hard limit), tell the audit
153 * daemon to force a rotation off of the file system. We also stop
154 * writing, which means this audit record is probably lost. If we
155 * fall below the minimum percent free blocks (soft limit), then
156 * kindly suggest to the audit daemon to do something.
157 */
158 if (mnt_stat->f_bfree < AUDIT_HARD_LIMIT_FREE_BLOCKS) {
159 (void)send_trigger(AUDIT_TRIGGER_NO_SPACE);
160 /*
161 * Hopefully userspace did something about all the previous
162 * triggers that were sent prior to this critical condition.
163 * If fail-stop is set, then we're done; goodnight Gracie.
164 */
165 if (audit_fail_stop)
166 panic("Audit log space exhausted and fail-stop set.");
167 else {
168 audit_suspended = 1;
169 ret = ENOSPC;
170 goto out;
171 }
172 } else
173 /*
174 * Send a message to the audit daemon that disk space is
175 * getting low.
176 *
177 * XXXAUDIT: Check math and block size calculation here.
178 */
179 if (audit_qctrl.aq_minfree != 0) {
180 temp = mnt_stat->f_blocks / (100 /
181 audit_qctrl.aq_minfree);
182 if (mnt_stat->f_bfree < temp)
183 (void)send_trigger(AUDIT_TRIGGER_LOW_SPACE);
184 }
185
186 /*
187 * Check if the current log file is full; if so, call for a log
188 * rotate. This is not an exact comparison; we may write some records
189 * over the limit. If that's not acceptable, then add a fudge factor
190 * here.
191 */
192 if ((audit_fstat.af_filesz != 0) &&
193 (audit_file_rotate_wait == 0) &&
194 (vattr.va_size >= audit_fstat.af_filesz)) {
195 audit_file_rotate_wait = 1;
196 (void)send_trigger(AUDIT_TRIGGER_OPEN_NEW);
197 }
198
199 /*
200 * If the estimated amount of audit data in the audit event queue
201 * (plus records allocated but not yet queued) has reached the amount
202 * of free space on the disk, then we need to go into an audit fail
203 * stop state, in which we do not permit the allocation/committing of
204 * any new audit records. We continue to process packets but don't
205 * allow any activities that might generate new records. In the
206 * future, we might want to detect when space is available again and
207 * allow operation to continue, but this behavior is sufficient to
208 * meet fail stop requirements in CAPP.
209 */
210 if (audit_fail_stop &&
211 (unsigned long)
212 ((audit_q_len + audit_pre_q_len + 1) * MAX_AUDIT_RECORD_SIZE) /
213 mnt_stat->f_bsize >= (unsigned long)(mnt_stat->f_bfree)) {
214 printf("audit_record_write: free space below size of audit "
215 "queue, failing stop\n");
216 audit_in_failure = 1;
217 }
218
219 ret = vn_rdwr(UIO_WRITE, vp, data, len, (off_t)0, UIO_SYSSPACE,
220 IO_APPEND|IO_UNIT, cred, NULL, NULL, td);
221
222out:
223 /*
224 * When we're done processing the current record, we have to check to
225 * see if we're in a failure mode, and if so, whether this was the
226 * last record left to be drained. If we're done draining, then we
227 * fsync the vnode and panic.
228 */
229 if (audit_in_failure && audit_q_len == 0 && audit_pre_q_len == 0) {
230 VOP_LOCK(vp, LK_DRAIN | LK_INTERLOCK, td);
231 (void)VOP_FSYNC(vp, MNT_WAIT, td);
232 VOP_UNLOCK(vp, 0, td);
233 panic("Audit store overflow; record queue drained.");
234 }
235
236 VFS_UNLOCK_GIANT(vfslocked);
237
238 return (ret);
239}
240
241/*
242 * If an appropriate signal has been received rotate the audit log based on
243 * the global replacement variables. Signal consumers as needed that the
244 * rotation has taken place.
245 *
246 * XXXRW: The global variables and CVs used to signal the audit_worker to
247 * perform a rotation are essentially a message queue of depth 1. It would
248 * be much nicer to actually use a message queue.
249 */
250static void
251audit_worker_rotate(struct ucred **audit_credp, struct vnode **audit_vpp,
252 struct thread *audit_td)
253{
254 int do_replacement_signal, vfslocked;
255 struct ucred *old_cred;
256 struct vnode *old_vp;
257
258 mtx_assert(&audit_mtx, MA_OWNED);
259
260 do_replacement_signal = 0;
261 while (audit_replacement_flag != 0) {
262 old_cred = *audit_credp;
263 old_vp = *audit_vpp;
264 *audit_credp = audit_replacement_cred;
265 *audit_vpp = audit_replacement_vp;
266 audit_replacement_cred = NULL;
267 audit_replacement_vp = NULL;
268 audit_replacement_flag = 0;
269
270 audit_enabled = (*audit_vpp != NULL);
271
272 /*
273 * XXX: What to do about write failures here?
274 */
275 if (old_vp != NULL) {
276 AUDIT_PRINTF(("Closing old audit file\n"));
277 mtx_unlock(&audit_mtx);
278 vfslocked = VFS_LOCK_GIANT(old_vp->v_mount);
279 vn_close(old_vp, AUDIT_CLOSE_FLAGS, old_cred,
280 audit_td);
281 VFS_UNLOCK_GIANT(vfslocked);
282 crfree(old_cred);
283 mtx_lock(&audit_mtx);
284 old_cred = NULL;
285 old_vp = NULL;
286 AUDIT_PRINTF(("Audit file closed\n"));
287 }
288 if (*audit_vpp != NULL) {
289 AUDIT_PRINTF(("Opening new audit file\n"));
290 }
291 do_replacement_signal = 1;
292 }
293
294 /*
295 * Signal that replacement have occurred to wake up and
296 * start any other replacements started in parallel. We can
297 * continue about our business in the mean time. We
298 * broadcast so that both new replacements can be inserted,
299 * but also so that the source(s) of replacement can return
300 * successfully.
301 */
302 if (do_replacement_signal)
303 cv_broadcast(&audit_replacement_cv);
304}
305
306/*
307 * Given a kernel audit record, process as required. Kernel audit records
308 * are converted to one, or possibly two, BSM records, depending on whether
309 * there is a user audit record present also. Kernel records need be
310 * converted to BSM before they can be written out. Both types will be
311 * written to disk, and audit pipes.
312 */
313static void
314audit_worker_process_record(struct vnode *audit_vp, struct ucred *audit_cred,
315 struct thread *audit_td, struct kaudit_record *ar)
316{
317 struct au_record *bsm;
|
| 318 au_class_t class;
319 au_event_t event;
|
318 int error, ret;
| 320 int error, ret;
|
| 321 au_id_t auid;
322 int sorf;
|
319
| 323
|
320 if (ar->k_ar_commit & AR_COMMIT_USER) {
| 324 if ((ar->k_ar_commit & AR_COMMIT_USER) &&
325 (ar->k_ar_commit & AR_PRESELECT_TRAIL)) {
|
321 error = audit_record_write(audit_vp, audit_cred, audit_td,
322 ar->k_udata, ar->k_ulen);
323 if (error && audit_panic_on_write_fail)
324 panic("audit_worker: write error %d\n", error);
325 else if (error)
326 printf("audit_worker: write error %d\n", error);
| 326 error = audit_record_write(audit_vp, audit_cred, audit_td,
327 ar->k_udata, ar->k_ulen);
328 if (error && audit_panic_on_write_fail)
329 panic("audit_worker: write error %d\n", error);
330 else if (error)
331 printf("audit_worker: write error %d\n", error);
|
327 audit_pipe_submit(ar->k_udata, ar->k_ulen);
| |
328 }
| 332 }
|
| 333 if ((ar->k_ar_commit & AR_COMMIT_USER) &&
334 (ar->k_ar_commit & AR_PRESELECT_PIPE))
335 audit_pipe_submit_user(ar->k_udata, ar->k_ulen);
|
329
| 336
|
330 if (ar->k_ar_commit & AR_COMMIT_KERNEL) {
331 ret = kaudit_to_bsm(ar, &bsm);
332 switch (ret) {
333 case BSM_NOAUDIT:
334 break;
| 337 if (!(ar->k_ar_commit & AR_COMMIT_KERNEL))
338 return;
|
335
| 339
|
336 case BSM_FAILURE:
337 printf("audit_worker_process_record: BSM_FAILURE\n");
338 break;
| 340 auid = ar->k_ar.ar_subj_auid;
341 event = ar->k_ar.ar_event;
342 class = au_event_class(event);
343 if (ar->k_ar.ar_errno == 0)
344 sorf = AU_PRS_SUCCESS;
345 else
346 sorf = AU_PRS_FAILURE;
|
339
| 347
|
340 case BSM_SUCCESS:
341 error = audit_record_write(audit_vp, audit_cred,
342 audit_td, bsm->data, bsm->len);
343 if (error && audit_panic_on_write_fail)
344 panic("audit_worker: write error %d\n",
345 error);
346 else if (error)
347 printf("audit_worker: write error %d\n",
348 error);
349 audit_pipe_submit(bsm->data, bsm->len);
350 kau_free(bsm);
351 break;
| 348 ret = kaudit_to_bsm(ar, &bsm);
349 switch (ret) {
350 case BSM_NOAUDIT:
351 return;
|
352
| 352
|
353 default:
354 panic("kaudit_to_bsm returned %d", ret);
355 }
| 353 case BSM_FAILURE:
354 printf("audit_worker_process_record: BSM_FAILURE\n");
355 return;
356
357 case BSM_SUCCESS:
358 break;
359
360 default:
361 panic("kaudit_to_bsm returned %d", ret);
|
356 }
| 362 }
|
| 363
364 if (ar->k_ar_commit & AR_PRESELECT_TRAIL) {
365 error = audit_record_write(audit_vp, audit_cred,
366 audit_td, bsm->data, bsm->len);
367 if (error && audit_panic_on_write_fail)
368 panic("audit_worker: write error %d\n",
369 error);
370 else if (error)
371 printf("audit_worker: write error %d\n",
372 error);
373 }
374 if (ar->k_ar_commit & AR_PRESELECT_PIPE)
375 audit_pipe_submit(auid, event, class, sorf,
376 ar->k_ar_commit & AR_PRESELECT_TRAIL, bsm->data,
377 bsm->len);
378 kau_free(bsm);
|
357}
358
359/*
360 * The audit_worker thread is responsible for watching the event queue,
361 * dequeueing records, converting them to BSM format, and committing them to
362 * disk. In order to minimize lock thrashing, records are dequeued in sets
363 * to a thread-local work queue. In addition, the audit_work performs the
364 * actual exchange of audit log vnode pointer, as audit_vp is a thread-local
365 * variable.
366 */
367static void
368audit_worker(void *arg)
369{
370 struct kaudit_queue ar_worklist;
371 struct kaudit_record *ar;
372 struct ucred *audit_cred;
373 struct thread *audit_td;
374 struct vnode *audit_vp;
375 int lowater_signal;
376
377 AUDIT_PRINTF(("audit_worker starting\n"));
378
379 /*
380 * These are thread-local variables requiring no synchronization.
381 */
382 TAILQ_INIT(&ar_worklist);
383 audit_cred = NULL;
384 audit_td = curthread;
385 audit_vp = NULL;
386
387 mtx_lock(&audit_mtx);
388 while (1) {
389 mtx_assert(&audit_mtx, MA_OWNED);
390
391 /*
392 * Wait for record or rotation events.
393 */
394 while (!audit_replacement_flag && TAILQ_EMPTY(&audit_q)) {
395 AUDIT_PRINTF(("audit_worker waiting\n"));
396 cv_wait(&audit_worker_cv, &audit_mtx);
397 AUDIT_PRINTF(("audit_worker woken up\n"));
398 AUDIT_PRINTF(("audit_worker: new vp = %p; value of "
399 "flag %d\n", audit_replacement_vp,
400 audit_replacement_flag));
401 }
402
403 /*
404 * First priority: replace the audit log target if requested.
405 */
406 audit_worker_rotate(&audit_cred, &audit_vp, audit_td);
407
408 /*
409 * If there are records in the global audit record queue,
410 * transfer them to a thread-local queue and process them
411 * one by one. If we cross the low watermark threshold,
412 * signal any waiting processes that they may wake up and
413 * continue generating records.
414 */
415 lowater_signal = 0;
416 while ((ar = TAILQ_FIRST(&audit_q))) {
417 TAILQ_REMOVE(&audit_q, ar, k_q);
418 audit_q_len--;
419 if (audit_q_len == audit_qctrl.aq_lowater)
420 lowater_signal++;
421 TAILQ_INSERT_TAIL(&ar_worklist, ar, k_q);
422 }
423 if (lowater_signal)
424 cv_broadcast(&audit_watermark_cv);
425
426 mtx_unlock(&audit_mtx);
427 while ((ar = TAILQ_FIRST(&ar_worklist))) {
428 TAILQ_REMOVE(&ar_worklist, ar, k_q);
429 audit_worker_process_record(audit_vp, audit_cred,
430 audit_td, ar);
431 audit_free(ar);
432 }
433 mtx_lock(&audit_mtx);
434 }
435}
436
437/*
438 * audit_rotate_vnode() is called by a user or kernel thread to configure or
439 * de-configure auditing on a vnode. The arguments are the replacement
440 * credential and vnode to substitute for the current credential and vnode,
441 * if any. If either is set to NULL, both should be NULL, and this is used
442 * to indicate that audit is being disabled. The real work is done in the
443 * audit_worker thread, but audit_rotate_vnode() waits synchronously for that
444 * to complete.
445 *
446 * The vnode should be referenced and opened by the caller. The credential
447 * should be referenced. audit_rotate_vnode() will own both references as of
448 * this call, so the caller should not release either.
449 *
450 * XXXAUDIT: Review synchronize communication logic. Really, this is a
451 * message queue of depth 1.
452 *
453 * XXXAUDIT: Enhance the comments below to indicate that we are basically
454 * acquiring ownership of the communications queue, inserting our message,
455 * and waiting for an acknowledgement.
456 */
457void
458audit_rotate_vnode(struct ucred *cred, struct vnode *vp)
459{
460
461 /*
462 * If other parallel log replacements have been requested, we wait
463 * until they've finished before continuing.
464 */
465 mtx_lock(&audit_mtx);
466 while (audit_replacement_flag != 0) {
467 AUDIT_PRINTF(("audit_rotate_vnode: sleeping to wait for "
468 "flag\n"));
469 cv_wait(&audit_replacement_cv, &audit_mtx);
470 AUDIT_PRINTF(("audit_rotate_vnode: woken up (flag %d)\n",
471 audit_replacement_flag));
472 }
473 audit_replacement_cred = cred;
474 audit_replacement_flag = 1;
475 audit_replacement_vp = vp;
476
477 /*
478 * Wake up the audit worker to perform the exchange once we
479 * release the mutex.
480 */
481 cv_signal(&audit_worker_cv);
482
483 /*
484 * Wait for the audit_worker to broadcast that a replacement has
485 * taken place; we know that once this has happened, our vnode
486 * has been replaced in, so we can return successfully.
487 */
488 AUDIT_PRINTF(("audit_rotate_vnode: waiting for news of "
489 "replacement\n"));
490 cv_wait(&audit_replacement_cv, &audit_mtx);
491 AUDIT_PRINTF(("audit_rotate_vnode: change acknowledged by "
492 "audit_worker (flag " "now %d)\n", audit_replacement_flag));
493 mtx_unlock(&audit_mtx);
494
495 audit_file_rotate_wait = 0; /* We can now request another rotation */
496}
497
498void
499audit_worker_init(void)
500{
501 int error;
502
503 cv_init(&audit_replacement_cv, "audit_replacement_cv");
504 error = kthread_create(audit_worker, NULL, &audit_thread, RFHIGHPID,
505 0, "audit_worker");
506 if (error)
507 panic("audit_worker_init: kthread_create returned %d", error);
508}
| 379}
380
381/*
382 * The audit_worker thread is responsible for watching the event queue,
383 * dequeueing records, converting them to BSM format, and committing them to
384 * disk. In order to minimize lock thrashing, records are dequeued in sets
385 * to a thread-local work queue. In addition, the audit_work performs the
386 * actual exchange of audit log vnode pointer, as audit_vp is a thread-local
387 * variable.
388 */
389static void
390audit_worker(void *arg)
391{
392 struct kaudit_queue ar_worklist;
393 struct kaudit_record *ar;
394 struct ucred *audit_cred;
395 struct thread *audit_td;
396 struct vnode *audit_vp;
397 int lowater_signal;
398
399 AUDIT_PRINTF(("audit_worker starting\n"));
400
401 /*
402 * These are thread-local variables requiring no synchronization.
403 */
404 TAILQ_INIT(&ar_worklist);
405 audit_cred = NULL;
406 audit_td = curthread;
407 audit_vp = NULL;
408
409 mtx_lock(&audit_mtx);
410 while (1) {
411 mtx_assert(&audit_mtx, MA_OWNED);
412
413 /*
414 * Wait for record or rotation events.
415 */
416 while (!audit_replacement_flag && TAILQ_EMPTY(&audit_q)) {
417 AUDIT_PRINTF(("audit_worker waiting\n"));
418 cv_wait(&audit_worker_cv, &audit_mtx);
419 AUDIT_PRINTF(("audit_worker woken up\n"));
420 AUDIT_PRINTF(("audit_worker: new vp = %p; value of "
421 "flag %d\n", audit_replacement_vp,
422 audit_replacement_flag));
423 }
424
425 /*
426 * First priority: replace the audit log target if requested.
427 */
428 audit_worker_rotate(&audit_cred, &audit_vp, audit_td);
429
430 /*
431 * If there are records in the global audit record queue,
432 * transfer them to a thread-local queue and process them
433 * one by one. If we cross the low watermark threshold,
434 * signal any waiting processes that they may wake up and
435 * continue generating records.
436 */
437 lowater_signal = 0;
438 while ((ar = TAILQ_FIRST(&audit_q))) {
439 TAILQ_REMOVE(&audit_q, ar, k_q);
440 audit_q_len--;
441 if (audit_q_len == audit_qctrl.aq_lowater)
442 lowater_signal++;
443 TAILQ_INSERT_TAIL(&ar_worklist, ar, k_q);
444 }
445 if (lowater_signal)
446 cv_broadcast(&audit_watermark_cv);
447
448 mtx_unlock(&audit_mtx);
449 while ((ar = TAILQ_FIRST(&ar_worklist))) {
450 TAILQ_REMOVE(&ar_worklist, ar, k_q);
451 audit_worker_process_record(audit_vp, audit_cred,
452 audit_td, ar);
453 audit_free(ar);
454 }
455 mtx_lock(&audit_mtx);
456 }
457}
458
459/*
460 * audit_rotate_vnode() is called by a user or kernel thread to configure or
461 * de-configure auditing on a vnode. The arguments are the replacement
462 * credential and vnode to substitute for the current credential and vnode,
463 * if any. If either is set to NULL, both should be NULL, and this is used
464 * to indicate that audit is being disabled. The real work is done in the
465 * audit_worker thread, but audit_rotate_vnode() waits synchronously for that
466 * to complete.
467 *
468 * The vnode should be referenced and opened by the caller. The credential
469 * should be referenced. audit_rotate_vnode() will own both references as of
470 * this call, so the caller should not release either.
471 *
472 * XXXAUDIT: Review synchronize communication logic. Really, this is a
473 * message queue of depth 1.
474 *
475 * XXXAUDIT: Enhance the comments below to indicate that we are basically
476 * acquiring ownership of the communications queue, inserting our message,
477 * and waiting for an acknowledgement.
478 */
479void
480audit_rotate_vnode(struct ucred *cred, struct vnode *vp)
481{
482
483 /*
484 * If other parallel log replacements have been requested, we wait
485 * until they've finished before continuing.
486 */
487 mtx_lock(&audit_mtx);
488 while (audit_replacement_flag != 0) {
489 AUDIT_PRINTF(("audit_rotate_vnode: sleeping to wait for "
490 "flag\n"));
491 cv_wait(&audit_replacement_cv, &audit_mtx);
492 AUDIT_PRINTF(("audit_rotate_vnode: woken up (flag %d)\n",
493 audit_replacement_flag));
494 }
495 audit_replacement_cred = cred;
496 audit_replacement_flag = 1;
497 audit_replacement_vp = vp;
498
499 /*
500 * Wake up the audit worker to perform the exchange once we
501 * release the mutex.
502 */
503 cv_signal(&audit_worker_cv);
504
505 /*
506 * Wait for the audit_worker to broadcast that a replacement has
507 * taken place; we know that once this has happened, our vnode
508 * has been replaced in, so we can return successfully.
509 */
510 AUDIT_PRINTF(("audit_rotate_vnode: waiting for news of "
511 "replacement\n"));
512 cv_wait(&audit_replacement_cv, &audit_mtx);
513 AUDIT_PRINTF(("audit_rotate_vnode: change acknowledged by "
514 "audit_worker (flag " "now %d)\n", audit_replacement_flag));
515 mtx_unlock(&audit_mtx);
516
517 audit_file_rotate_wait = 0; /* We can now request another rotation */
518}
519
520void
521audit_worker_init(void)
522{
523 int error;
524
525 cv_init(&audit_replacement_cv, "audit_replacement_cv");
526 error = kthread_create(audit_worker, NULL, &audit_thread, RFHIGHPID,
527 0, "audit_worker");
528 if (error)
529 panic("audit_worker_init: kthread_create returned %d", error);
530}
|