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1c79356b 1/*
91447636 2 * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
1c79356b
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3 *
4 * @APPLE_LICENSE_HEADER_START@
5 *
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6 * The contents of this file constitute Original Code as defined in and
7 * are subject to the Apple Public Source License Version 1.1 (the
8 * "License"). You may not use this file except in compliance with the
9 * License. Please obtain a copy of the License at
10 * http://www.apple.com/publicsource and read it before using this file.
1c79356b 11 *
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12 * This Original Code and all software distributed under the License are
13 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
1c79356b
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14 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
15 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
e5568f75
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16 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
17 * License for the specific language governing rights and limitations
18 * under the License.
1c79356b
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19 *
20 * @APPLE_LICENSE_HEADER_END@
21 */
22/* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
23/*-
24 * Copyright (c) 1982, 1986, 1989, 1993
25 * The Regents of the University of California. All rights reserved.
26 * (c) UNIX System Laboratories, Inc.
27 * All or some portions of this file are derived from material licensed
28 * to the University of California by American Telephone and Telegraph
29 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
30 * the permission of UNIX System Laboratories, Inc.
31 *
32 * Redistribution and use in source and binary forms, with or without
33 * modification, are permitted provided that the following conditions
34 * are met:
35 * 1. Redistributions of source code must retain the above copyright
36 * notice, this list of conditions and the following disclaimer.
37 * 2. Redistributions in binary form must reproduce the above copyright
38 * notice, this list of conditions and the following disclaimer in the
39 * documentation and/or other materials provided with the distribution.
40 * 3. All advertising materials mentioning features or use of this software
41 * must display the following acknowledgement:
42 * This product includes software developed by the University of
43 * California, Berkeley and its contributors.
44 * 4. Neither the name of the University nor the names of its contributors
45 * may be used to endorse or promote products derived from this software
46 * without specific prior written permission.
47 *
48 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
49 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
50 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
51 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
52 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
53 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
54 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
55 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
56 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
57 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
58 * SUCH DAMAGE.
59 *
60 * @(#)kern_acct.c 8.1 (Berkeley) 6/14/93
61 */
62/* HISTORY
63 * 08-May-95 Mac Gillon (mgillon) at NeXT
64 * Purged old history
65 * New version based on 4.4
66 */
67
68
69#include <sys/param.h>
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70#include <sys/proc_internal.h>
71#include <sys/kauth.h>
72#include <sys/mount_internal.h>
73#include <sys/vnode_internal.h>
74#include <sys/file_internal.h>
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75#include <sys/syslog.h>
76#include <sys/kernel.h>
77#include <sys/namei.h>
78#include <sys/errno.h>
79#include <sys/acct.h>
80#include <sys/resourcevar.h>
81#include <sys/ioctl.h>
82#include <sys/tty.h>
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83#include <sys/sysproto.h>
84#include <machine/spl.h>
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85
86/*
87 * The routines implemented in this file are described in:
88 * Leffler, et al.: The Design and Implementation of the 4.3BSD
89 * UNIX Operating System (Addison Welley, 1989)
90 * on pages 62-63.
91 *
92 * Arguably, to simplify accounting operations, this mechanism should
93 * be replaced by one in which an accounting log file (similar to /dev/klog)
94 * is read by a user process, etc. However, that has its own problems.
95 */
96
97/*
98 * Internal accounting functions.
99 * The former's operation is described in Leffler, et al., and the latter
100 * was provided by UCB with the 4.4BSD-Lite release
101 */
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102comp_t encode_comp_t(u_long, u_long);
103void acctwatch(void *);
104void acctwatch_funnel(void *);
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105
106/*
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107 * Accounting vnode pointer, and suspended accounting vnode pointer. States
108 * are as follows:
109 *
110 * acctp suspend_acctp state
111 * ------------- ------------ ------------------------------
112 * NULL NULL Accounting disabled
113 * !NULL NULL Accounting enabled
114 * NULL !NULL Accounting enabled, but suspended
115 * !NULL !NULL <not allowed>
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116 */
117struct vnode *acctp;
91447636 118struct vnode *suspend_acctp;
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119
120/*
121 * Values associated with enabling and disabling accounting
122 */
123int acctsuspend = 2; /* stop accounting when < 2% free space left */
124int acctresume = 4; /* resume when free space risen to > 4% */
125int acctchkfreq = 15; /* frequency (in seconds) to check space */
126
127/*
128 * Accounting system call. Written based on the specification and
129 * previous implementation done by Mark Tinguely.
130 */
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131int
132acct(struct proc *p, struct acct_args *uap, __unused int *retval)
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133{
134 struct nameidata nd;
135 int error;
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136 struct vfs_context context;
137
138 context.vc_proc = p;
139 context.vc_ucred = kauth_cred_get();
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140
141 /* Make sure that the caller is root. */
91447636 142 if ((error = suser(kauth_cred_get(), &p->p_acflag)))
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143 return (error);
144
145 /*
146 * If accounting is to be started to a file, open that file for
147 * writing and make sure it's a 'normal'.
148 */
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149 if (uap->path != USER_ADDR_NULL) {
150 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_USERSPACE, uap->path, &context);
151 if ((error = vn_open(&nd, FWRITE, 0)))
1c79356b 152 return (error);
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153 vnode_put(nd.ni_vp);
154
1c79356b 155 if (nd.ni_vp->v_type != VREG) {
91447636 156 vn_close(nd.ni_vp, FWRITE, kauth_cred_get(), p);
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157 return (EACCES);
158 }
159 }
160
161 /*
162 * If accounting was previously enabled, kill the old space-watcher,
163 * close the file, and (if no new file was specified, leave).
164 */
91447636 165 if (acctp != NULLVP || suspend_acctp != NULLVP) {
1c79356b 166 untimeout(acctwatch_funnel, NULL);
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167 error = vn_close((acctp != NULLVP ? acctp : suspend_acctp), FWRITE,
168 kauth_cred_get(), p);
169
170 acctp = suspend_acctp = NULLVP;
1c79356b 171 }
91447636 172 if (uap->path == USER_ADDR_NULL)
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173 return (error);
174
175 /*
176 * Save the new accounting file vnode, and schedule the new
177 * free space watcher.
178 */
179 acctp = nd.ni_vp;
180 acctwatch(NULL);
181 return (error);
182}
183
184/*
185 * Write out process accounting information, on process exit.
186 * Data to be written out is specified in Leffler, et al.
187 * and are enumerated below. (They're also noted in the system
188 * "acct.h" header file.)
189 */
91447636 190int
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191acct_process(p)
192 struct proc *p;
193{
91447636 194 struct acct an_acct;
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195 struct rusage *r;
196 struct timeval ut, st, tmp;
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197 int t;
198 int error;
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199 struct vnode *vp;
200
201 /* If accounting isn't enabled, don't bother */
202 vp = acctp;
203 if (vp == NULLVP)
204 return (0);
205
206 /*
207 * Get process accounting information.
208 */
209
210 /* (1) The name of the command that ran */
91447636 211 bcopy(p->p_comm, an_acct.ac_comm, sizeof an_acct.ac_comm);
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212
213 /* (2) The amount of user and system time that was used */
214 calcru(p, &ut, &st, NULL);
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215 an_acct.ac_utime = encode_comp_t(ut.tv_sec, ut.tv_usec);
216 an_acct.ac_stime = encode_comp_t(st.tv_sec, st.tv_usec);
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217
218 /* (3) The elapsed time the commmand ran (and its starting time) */
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219 an_acct.ac_btime = p->p_stats->p_start.tv_sec;
220 microtime(&tmp);
1c79356b 221 timevalsub(&tmp, &p->p_stats->p_start);
91447636 222 an_acct.ac_etime = encode_comp_t(tmp.tv_sec, tmp.tv_usec);
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223
224 /* (4) The average amount of memory used */
225 r = &p->p_stats->p_ru;
226 tmp = ut;
227 timevaladd(&tmp, &st);
228 t = tmp.tv_sec * hz + tmp.tv_usec / tick;
229 if (t)
91447636 230 an_acct.ac_mem = (r->ru_ixrss + r->ru_idrss + r->ru_isrss) / t;
1c79356b 231 else
91447636 232 an_acct.ac_mem = 0;
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233
234 /* (5) The number of disk I/O operations done */
91447636 235 an_acct.ac_io = encode_comp_t(r->ru_inblock + r->ru_oublock, 0);
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236
237 /* (6) The UID and GID of the process */
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238 an_acct.ac_uid = p->p_ucred->cr_ruid;
239 an_acct.ac_gid = p->p_ucred->cr_rgid;
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240
241 /* (7) The terminal from which the process was started */
242 if ((p->p_flag & P_CONTROLT) && p->p_pgrp->pg_session->s_ttyp)
91447636 243 an_acct.ac_tty = p->p_pgrp->pg_session->s_ttyp->t_dev;
1c79356b 244 else
91447636 245 an_acct.ac_tty = NODEV;
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246
247 /* (8) The boolean flags that tell how the process terminated, etc. */
91447636 248 an_acct.ac_flag = p->p_acflag;
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249
250 /*
251 * Now, just write the accounting information to the file.
252 */
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253 if ((error = vnode_getwithref(vp)) == 0) {
254 error = vn_rdwr(UIO_WRITE, vp, (caddr_t)&an_acct, sizeof (an_acct),
255 (off_t)0, UIO_SYSSPACE32, IO_APPEND|IO_UNIT, p->p_ucred,
256 (int *)0, p);
257 vnode_put(vp);
258 }
259 return (error);
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260}
261
262/*
263 * Encode_comp_t converts from ticks in seconds and microseconds
264 * to ticks in 1/AHZ seconds. The encoding is described in
265 * Leffler, et al., on page 63.
266 */
267
268#define MANTSIZE 13 /* 13 bit mantissa. */
269#define EXPSIZE 3 /* Base 8 (3 bit) exponent. */
270#define MAXFRACT ((1 << MANTSIZE) - 1) /* Maximum fractional value. */
271
272comp_t
273encode_comp_t(s, us)
274 u_long s, us;
275{
276 int exp, rnd;
277
278 exp = 0;
279 rnd = 0;
280 s *= AHZ;
281 s += us / (1000000 / AHZ); /* Maximize precision. */
282
283 while (s > MAXFRACT) {
284 rnd = s & (1 << (EXPSIZE - 1)); /* Round up? */
285 s >>= EXPSIZE; /* Base 8 exponent == 3 bit shift. */
286 exp++;
287 }
288
289 /* If we need to round up, do it (and handle overflow correctly). */
290 if (rnd && (++s > MAXFRACT)) {
291 s >>= EXPSIZE;
292 exp++;
293 }
294
295 /* Clean it up and polish it off. */
296 exp <<= MANTSIZE; /* Shift the exponent into place */
297 exp += s; /* and add on the mantissa. */
298 return (exp);
299}
300
301void
302acctwatch_funnel(a)
303 void *a;
304{
305 thread_funnel_set(kernel_flock, TRUE);
306 acctwatch(a);
307 thread_funnel_set(kernel_flock, FALSE);
308}
309
310
311/*
312 * Periodically check the file system to see if accounting
313 * should be turned on or off. Beware the case where the vnode
314 * has been vgone()'d out from underneath us, e.g. when the file
315 * system containing the accounting file has been forcibly unmounted.
316 */
317/* ARGSUSED */
318void
91447636 319acctwatch(__unused void *a)
1c79356b 320{
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321 struct vfs_context context;
322 struct vfs_attr va;
323
324 VFSATTR_INIT(&va);
325 VFSATTR_WANTED(&va, f_blocks);
326 VFSATTR_WANTED(&va, f_bavail);
327 context.vc_proc = current_proc();
328 context.vc_ucred = kauth_cred_get();
329
330 if (suspend_acctp != NULLVP) {
331 /*
332 * Resuming accounting when accounting is suspended, and the
333 * filesystem containing the suspended accounting file goes
334 * below a low watermark
335 */
336 if (suspend_acctp->v_type == VBAD) {
337 (void) vn_close(suspend_acctp, FWRITE, NOCRED, NULL);
338 suspend_acctp = NULLVP;
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339 return;
340 }
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341 (void)vfs_getattr(suspend_acctp->v_mount, &va, &context);
342 if (va.f_bavail > acctresume * va.f_blocks / 100) {
343 acctp = suspend_acctp;
344 suspend_acctp = NULLVP;
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345 log(LOG_NOTICE, "Accounting resumed\n");
346 }
347 } else if (acctp != NULLVP) {
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348 /*
349 * Suspending accounting when accounting is currently active,
350 * and the filesystem containing the active accounting file
351 * goes over a high watermark
352 */
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353 if (acctp->v_type == VBAD) {
354 (void) vn_close(acctp, FWRITE, NOCRED, NULL);
355 acctp = NULLVP;
356 return;
357 }
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358 (void)vfs_getattr(acctp->v_mount, &va, &context);
359 if (va.f_bavail <= acctsuspend * va.f_blocks / 100) {
360 suspend_acctp = acctp;
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361 acctp = NULLVP;
362 log(LOG_NOTICE, "Accounting suspended\n");
363 }
364 } else {
365 return;
366 }
367
368 timeout(acctwatch_funnel, NULL, acctchkfreq * hz);
369}