1/*
2 * Copyright (c) 2000-2010 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28/* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
29/*-
30 * Copyright (c) 1982, 1986, 1989, 1993
31 * The Regents of the University of California. All rights reserved.
32 * (c) UNIX System Laboratories, Inc.
33 * All or some portions of this file are derived from material licensed
34 * to the University of California by American Telephone and Telegraph
35 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
36 * the permission of UNIX System Laboratories, Inc.
37 *
38 * Redistribution and use in source and binary forms, with or without
39 * modification, are permitted provided that the following conditions
40 * are met:
41 * 1. Redistributions of source code must retain the above copyright
42 * notice, this list of conditions and the following disclaimer.
43 * 2. Redistributions in binary form must reproduce the above copyright
44 * notice, this list of conditions and the following disclaimer in the
45 * documentation and/or other materials provided with the distribution.
46 * 3. All advertising materials mentioning features or use of this software
47 * must display the following acknowledgement:
48 * This product includes software developed by the University of
49 * California, Berkeley and its contributors.
50 * 4. Neither the name of the University nor the names of its contributors
51 * may be used to endorse or promote products derived from this software
52 * without specific prior written permission.
53 *
54 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
55 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
56 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
57 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
58 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
59 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
60 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
61 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
62 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
63 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
64 * SUCH DAMAGE.
65 *
66 * @(#)kern_acct.c 8.1 (Berkeley) 6/14/93
67 */
68/* HISTORY
69 * 08-May-95 Mac Gillon (mgillon) at NeXT
70 * Purged old history
71 * New version based on 4.4
72 */
73/*
74 * NOTICE: This file was modified by SPARTA, Inc. in 2005 to introduce
75 * support for mandatory and extensible security protections. This notice
76 * is included in support of clause 2.2 (b) of the Apple Public License,
77 * Version 2.0.
78 */
79
80
81#include <sys/param.h>
82#include <sys/proc_internal.h>
83#include <sys/kauth.h>
84#include <sys/mount_internal.h>
85#include <sys/vnode_internal.h>
86#include <sys/file_internal.h>
87#include <sys/syslog.h>
88#include <sys/kernel.h>
89#include <sys/namei.h>
90#include <sys/errno.h>
91#include <sys/acct.h>
92#include <sys/resourcevar.h>
93#include <sys/ioctl.h>
94#include <sys/tty.h>
95#include <sys/sysproto.h>
96#if CONFIG_MACF
97#include <security/mac_framework.h>
98#endif
99
100/*
101 * The routines implemented in this file are described in:
102 * Leffler, et al.: The Design and Implementation of the 4.3BSD
103 * UNIX Operating System (Addison Welley, 1989)
104 * on pages 62-63.
105 *
106 * Arguably, to simplify accounting operations, this mechanism should
107 * be replaced by one in which an accounting log file (similar to /dev/klog)
108 * is read by a user process, etc. However, that has its own problems.
109 */
110
111/*
112 * Internal accounting functions.
113 * The former's operation is described in Leffler, et al., and the latter
114 * was provided by UCB with the 4.4BSD-Lite release
115 */
116comp_t encode_comp_t(uint32_t, uint32_t);
117void acctwatch(void *);
118void acct_init(void);
119
120/*
121 * Accounting vnode pointer, and suspended accounting vnode pointer. States
122 * are as follows:
123 *
124 * acctp suspend_acctp state
125 * ------------- ------------ ------------------------------
126 * NULL NULL Accounting disabled
127 * !NULL NULL Accounting enabled
128 * NULL !NULL Accounting enabled, but suspended
129 * !NULL !NULL <not allowed>
130 */
131struct vnode *acctp;
132struct vnode *suspend_acctp;
133
134/*
135 * Values associated with enabling and disabling accounting
136 */
137int acctsuspend = 2; /* stop accounting when < 2% free space left */
138int acctresume = 4; /* resume when free space risen to > 4% */
139int acctchkfreq = 15; /* frequency (in seconds) to check space */
140
141
142static lck_grp_t *acct_subsys_lck_grp;
143static lck_mtx_t *acct_subsys_mutex;
144
145#define ACCT_SUBSYS_LOCK() lck_mtx_lock(acct_subsys_mutex)
146#define ACCT_SUBSYS_UNLOCK() lck_mtx_unlock(acct_subsys_mutex)
147
148void
149acct_init(void)
150{
151 acct_subsys_lck_grp = lck_grp_alloc_init("acct", NULL);
152 acct_subsys_mutex = lck_mtx_alloc_init(acct_subsys_lck_grp, NULL);
153}
154
155
156/*
157 * Accounting system call. Written based on the specification and
158 * previous implementation done by Mark Tinguely.
159 */
160int
161acct(proc_t p, struct acct_args *uap, __unused int *retval)
162{
163 struct nameidata nd;
164 int error;
165 struct vfs_context *ctx;
166
167 ctx = vfs_context_current();
168
169 /* Make sure that the caller is root. */
170 if ((error = suser(vfs_context_ucred(ctx), &p->p_acflag)))
171 return (error);
172
173 /*
174 * If accounting is to be started to a file, open that file for
175 * writing and make sure it's a 'normal'.
176 */
177 if (uap->path != USER_ADDR_NULL) {
178 NDINIT(&nd, LOOKUP, OP_OPEN, NOFOLLOW, UIO_USERSPACE, uap->path, ctx);
179 if ((error = vn_open(&nd, FWRITE, 0)))
180 return (error);
181#if CONFIG_MACF
182 error = mac_system_check_acct(vfs_context_ucred(ctx), nd.ni_vp);
183 if (error) {
184 vnode_put(nd.ni_vp);
185 vn_close(nd.ni_vp, FWRITE, ctx);
186 return (error);
187 }
188#endif
189 vnode_put(nd.ni_vp);
190
191 if (nd.ni_vp->v_type != VREG) {
192 vn_close(nd.ni_vp, FWRITE, ctx);
193 return (EACCES);
194 }
195 }
196#if CONFIG_MACF
197 else {
198 error = mac_system_check_acct(vfs_context_ucred(ctx), NULL);
199 if (error)
200 return (error);
201 }
202#endif
203
204 /*
205 * If accounting was previously enabled, kill the old space-watcher,
206 * close the file, and (if no new file was specified, leave).
207 */
208 ACCT_SUBSYS_LOCK();
209 if (acctp != NULLVP || suspend_acctp != NULLVP) {
210 untimeout(acctwatch, NULL);
211 error = vn_close((acctp != NULLVP ? acctp : suspend_acctp),
212 FWRITE, vfs_context_current());
213
214 acctp = suspend_acctp = NULLVP;
215 }
216 if (uap->path == USER_ADDR_NULL) {
217 ACCT_SUBSYS_UNLOCK();
218 return (error);
219 }
220
221 /*
222 * Save the new accounting file vnode, and schedule the new
223 * free space watcher.
224 */
225 acctp = nd.ni_vp;
226 ACCT_SUBSYS_UNLOCK();
227
228 acctwatch(NULL);
229 return (error);
230}
231
232/*
233 * Write out process accounting information, on process exit.
234 * Data to be written out is specified in Leffler, et al.
235 * and are enumerated below. (They're also noted in the system
236 * "acct.h" header file.)
237 */
238int
239acct_process(proc_t p)
240{
241 struct acct an_acct;
242 struct rusage rup, *r;
243 struct timeval ut, st, tmp;
244 int t;
245 int error;
246 struct vnode *vp;
247 kauth_cred_t safecred;
248 struct session * sessp;
249 struct tty *tp;
250
251 /* If accounting isn't enabled, don't bother */
252 ACCT_SUBSYS_LOCK();
253 vp = acctp;
254 if (vp == NULLVP) {
255 ACCT_SUBSYS_UNLOCK();
256 return (0);
257 }
258
259 /*
260 * Get process accounting information.
261 */
262
263 /* (1) The name of the command that ran */
264 bcopy(p->p_comm, an_acct.ac_comm, sizeof an_acct.ac_comm);
265
266 /* (2) The amount of user and system time that was used */
267 calcru(p, &ut, &st, NULL);
268 an_acct.ac_utime = encode_comp_t(ut.tv_sec, ut.tv_usec);
269 an_acct.ac_stime = encode_comp_t(st.tv_sec, st.tv_usec);
270
271 /* (3) The elapsed time the commmand ran (and its starting time) */
272 an_acct.ac_btime = p->p_start.tv_sec;
273 microtime(&tmp);
274 timevalsub(&tmp, &p->p_start);
275 an_acct.ac_etime = encode_comp_t(tmp.tv_sec, tmp.tv_usec);
276
277 /* (4) The average amount of memory used */
278 proc_lock(p);
279 rup = p->p_stats->p_ru;
280 proc_unlock(p);
281 r = &rup;
282 tmp = ut;
283 timevaladd(&tmp, &st);
284 t = tmp.tv_sec * hz + tmp.tv_usec / tick;
285 if (t)
286 an_acct.ac_mem = (r->ru_ixrss + r->ru_idrss + r->ru_isrss) / t;
287 else
288 an_acct.ac_mem = 0;
289
290 /* (5) The number of disk I/O operations done */
291 an_acct.ac_io = encode_comp_t(r->ru_inblock + r->ru_oublock, 0);
292
293 /* (6) The UID and GID of the process */
294 safecred = kauth_cred_proc_ref(p);
295
296 an_acct.ac_uid = kauth_cred_getruid(safecred);
297 an_acct.ac_gid = kauth_cred_getrgid(safecred);
298
299 /* (7) The terminal from which the process was started */
300
301 sessp = proc_session(p);
302 if ((p->p_flag & P_CONTROLT) && (sessp != SESSION_NULL) && ((tp = SESSION_TP(sessp)) != TTY_NULL)) {
303 tty_lock(tp);
304 an_acct.ac_tty = tp->t_dev;
305 tty_unlock(tp);
306 }else
307 an_acct.ac_tty = NODEV;
308
309 if (sessp != SESSION_NULL)
310 session_rele(sessp);
311
312 /* (8) The boolean flags that tell how the process terminated, etc. */
313 an_acct.ac_flag = p->p_acflag;
314
315 /*
316 * Now, just write the accounting information to the file.
317 */
318 if ((error = vnode_getwithref(vp)) == 0) {
319 error = vn_rdwr(UIO_WRITE, vp, (caddr_t)&an_acct, sizeof (an_acct),
320 (off_t)0, UIO_SYSSPACE, IO_APPEND|IO_UNIT, safecred,
321 (int *)0, p);
322 vnode_put(vp);
323 }
324
325 kauth_cred_unref(&safecred);
326 ACCT_SUBSYS_UNLOCK();
327
328 return (error);
329}
330
331/*
332 * Encode_comp_t converts from ticks in seconds and microseconds
333 * to ticks in 1/AHZ seconds. The encoding is described in
334 * Leffler, et al., on page 63.
335 */
336
337#define MANTSIZE 13 /* 13 bit mantissa. */
338#define EXPSIZE 3 /* Base 8 (3 bit) exponent. */
339#define MAXFRACT ((1 << MANTSIZE) - 1) /* Maximum fractional value. */
340
341comp_t
342encode_comp_t(uint32_t s, uint32_t us)
343{
344 int exp, rnd;
345
346 exp = 0;
347 rnd = 0;
348 s *= AHZ;
349 s += us / (1000000 / AHZ); /* Maximize precision. */
350
351 while (s > MAXFRACT) {
352 rnd = s & (1 << (EXPSIZE - 1)); /* Round up? */
353 s >>= EXPSIZE; /* Base 8 exponent == 3 bit shift. */
354 exp++;
355 }
356
357 /* If we need to round up, do it (and handle overflow correctly). */
358 if (rnd && (++s > MAXFRACT)) {
359 s >>= EXPSIZE;
360 exp++;
361 }
362
363 /* Clean it up and polish it off. */
364 exp <<= MANTSIZE; /* Shift the exponent into place */
365 exp += s; /* and add on the mantissa. */
366 return (exp);
367}
368
369/*
370 * Periodically check the file system to see if accounting
371 * should be turned on or off. Beware the case where the vnode
372 * has been vgone()'d out from underneath us, e.g. when the file
373 * system containing the accounting file has been forcibly unmounted.
374 */
375/* ARGSUSED */
376void
377acctwatch(__unused void *a)
378{
379 vfs_context_t ctx = vfs_context_current();
380 struct vfs_attr va;
381
382 VFSATTR_INIT(&va);
383 VFSATTR_WANTED(&va, f_blocks);
384 VFSATTR_WANTED(&va, f_bavail);
385
386 ACCT_SUBSYS_LOCK();
387 if (suspend_acctp != NULLVP) {
388 /*
389 * Resuming accounting when accounting is suspended, and the
390 * filesystem containing the suspended accounting file goes
391 * below a low watermark
392 */
393 if (suspend_acctp->v_type == VBAD) {
394 (void) vn_close(suspend_acctp, FWRITE, vfs_context_kernel());
395 suspend_acctp = NULLVP;
396 ACCT_SUBSYS_UNLOCK();
397 return;
398 }
399 (void)vfs_getattr(suspend_acctp->v_mount, &va, ctx);
400 if (va.f_bavail > acctresume * va.f_blocks / 100) {
401 acctp = suspend_acctp;
402 suspend_acctp = NULLVP;
403 log(LOG_NOTICE, "Accounting resumed\n");
404 }
405 } else if (acctp != NULLVP) {
406 /*
407 * Suspending accounting when accounting is currently active,
408 * and the filesystem containing the active accounting file
409 * goes over a high watermark
410 */
411 if (acctp->v_type == VBAD) {
412 (void) vn_close(acctp, FWRITE, vfs_context_kernel());
413 acctp = NULLVP;
414 ACCT_SUBSYS_UNLOCK();
415 return;
416 }
417 (void)vfs_getattr(acctp->v_mount, &va, ctx);
418 if (va.f_bavail <= acctsuspend * va.f_blocks / 100) {
419 suspend_acctp = acctp;
420 acctp = NULLVP;
421 log(LOG_NOTICE, "Accounting suspended\n");
422 }
423 } else {
424 ACCT_SUBSYS_UNLOCK();
425 return;
426 }
427 ACCT_SUBSYS_UNLOCK();
428
429 timeout(acctwatch, NULL, acctchkfreq * hz);
430}
431