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1c79356b 1/*
6d2010ae 2 * Copyright (c) 2000-2010 Apple Inc. All rights reserved.
5d5c5d0d 3 *
2d21ac55 4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
1c79356b 5 *
2d21ac55
A
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.
8f6c56a5 14 *
2d21ac55
A
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
8f6c56a5
A
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
2d21ac55
A
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.
8f6c56a5 25 *
2d21ac55 26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
1c79356b
A
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 */
2d21ac55
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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 */
1c79356b
A
79
80
81#include <sys/param.h>
91447636
A
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>
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A
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>
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95#include <sys/sysproto.h>
96#include <machine/spl.h>
2d21ac55
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97#if CONFIG_MACF
98#include <security/mac_framework.h>
99#endif
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100
101/*
102 * The routines implemented in this file are described in:
103 * Leffler, et al.: The Design and Implementation of the 4.3BSD
104 * UNIX Operating System (Addison Welley, 1989)
105 * on pages 62-63.
106 *
107 * Arguably, to simplify accounting operations, this mechanism should
108 * be replaced by one in which an accounting log file (similar to /dev/klog)
109 * is read by a user process, etc. However, that has its own problems.
110 */
111
112/*
113 * Internal accounting functions.
114 * The former's operation is described in Leffler, et al., and the latter
115 * was provided by UCB with the 4.4BSD-Lite release
116 */
b0d623f7 117comp_t encode_comp_t(uint32_t, uint32_t);
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118void acctwatch(void *);
119void acctwatch_funnel(void *);
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120
121/*
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122 * Accounting vnode pointer, and suspended accounting vnode pointer. States
123 * are as follows:
124 *
125 * acctp suspend_acctp state
126 * ------------- ------------ ------------------------------
127 * NULL NULL Accounting disabled
128 * !NULL NULL Accounting enabled
129 * NULL !NULL Accounting enabled, but suspended
130 * !NULL !NULL <not allowed>
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131 */
132struct vnode *acctp;
91447636 133struct vnode *suspend_acctp;
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134
135/*
136 * Values associated with enabling and disabling accounting
137 */
138int acctsuspend = 2; /* stop accounting when < 2% free space left */
139int acctresume = 4; /* resume when free space risen to > 4% */
140int acctchkfreq = 15; /* frequency (in seconds) to check space */
141
142/*
143 * Accounting system call. Written based on the specification and
144 * previous implementation done by Mark Tinguely.
145 */
91447636 146int
2d21ac55 147acct(proc_t p, struct acct_args *uap, __unused int *retval)
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148{
149 struct nameidata nd;
150 int error;
2d21ac55 151 struct vfs_context *ctx;
91447636 152
2d21ac55 153 ctx = vfs_context_current();
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154
155 /* Make sure that the caller is root. */
2d21ac55 156 if ((error = suser(vfs_context_ucred(ctx), &p->p_acflag)))
1c79356b
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157 return (error);
158
159 /*
160 * If accounting is to be started to a file, open that file for
161 * writing and make sure it's a 'normal'.
162 */
91447636 163 if (uap->path != USER_ADDR_NULL) {
6d2010ae 164 NDINIT(&nd, LOOKUP, OP_OPEN, NOFOLLOW, UIO_USERSPACE, uap->path, ctx);
91447636 165 if ((error = vn_open(&nd, FWRITE, 0)))
1c79356b 166 return (error);
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167#if CONFIG_MACF
168 error = mac_system_check_acct(vfs_context_ucred(ctx), nd.ni_vp);
169 if (error) {
170 vnode_put(nd.ni_vp);
171 vn_close(nd.ni_vp, FWRITE, ctx);
172 return (error);
173 }
174#endif
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175 vnode_put(nd.ni_vp);
176
1c79356b 177 if (nd.ni_vp->v_type != VREG) {
2d21ac55 178 vn_close(nd.ni_vp, FWRITE, ctx);
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179 return (EACCES);
180 }
181 }
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182#if CONFIG_MACF
183 else {
184 error = mac_system_check_acct(vfs_context_ucred(ctx), NULL);
185 if (error)
186 return (error);
187 }
188#endif
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189
190 /*
191 * If accounting was previously enabled, kill the old space-watcher,
192 * close the file, and (if no new file was specified, leave).
193 */
91447636 194 if (acctp != NULLVP || suspend_acctp != NULLVP) {
1c79356b 195 untimeout(acctwatch_funnel, NULL);
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196 error = vn_close((acctp != NULLVP ? acctp : suspend_acctp),
197 FWRITE, vfs_context_current());
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198
199 acctp = suspend_acctp = NULLVP;
1c79356b 200 }
91447636 201 if (uap->path == USER_ADDR_NULL)
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202 return (error);
203
204 /*
205 * Save the new accounting file vnode, and schedule the new
206 * free space watcher.
207 */
208 acctp = nd.ni_vp;
209 acctwatch(NULL);
210 return (error);
211}
212
213/*
214 * Write out process accounting information, on process exit.
215 * Data to be written out is specified in Leffler, et al.
216 * and are enumerated below. (They're also noted in the system
217 * "acct.h" header file.)
218 */
91447636 219int
2d21ac55 220acct_process(proc_t p)
1c79356b 221{
91447636 222 struct acct an_acct;
2d21ac55 223 struct rusage rup, *r;
1c79356b 224 struct timeval ut, st, tmp;
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225 int t;
226 int error;
1c79356b 227 struct vnode *vp;
0c530ab8 228 kauth_cred_t safecred;
2d21ac55 229 struct session * sessp;
b0d623f7 230 struct tty *tp;
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231
232 /* If accounting isn't enabled, don't bother */
233 vp = acctp;
234 if (vp == NULLVP)
235 return (0);
236
237 /*
238 * Get process accounting information.
239 */
240
241 /* (1) The name of the command that ran */
91447636 242 bcopy(p->p_comm, an_acct.ac_comm, sizeof an_acct.ac_comm);
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243
244 /* (2) The amount of user and system time that was used */
245 calcru(p, &ut, &st, NULL);
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246 an_acct.ac_utime = encode_comp_t(ut.tv_sec, ut.tv_usec);
247 an_acct.ac_stime = encode_comp_t(st.tv_sec, st.tv_usec);
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248
249 /* (3) The elapsed time the commmand ran (and its starting time) */
2d21ac55 250 an_acct.ac_btime = p->p_start.tv_sec;
91447636 251 microtime(&tmp);
2d21ac55 252 timevalsub(&tmp, &p->p_start);
91447636 253 an_acct.ac_etime = encode_comp_t(tmp.tv_sec, tmp.tv_usec);
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254
255 /* (4) The average amount of memory used */
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256 proc_lock(p);
257 rup = p->p_stats->p_ru;
258 proc_unlock(p);
259 r = &rup;
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260 tmp = ut;
261 timevaladd(&tmp, &st);
262 t = tmp.tv_sec * hz + tmp.tv_usec / tick;
263 if (t)
91447636 264 an_acct.ac_mem = (r->ru_ixrss + r->ru_idrss + r->ru_isrss) / t;
1c79356b 265 else
91447636 266 an_acct.ac_mem = 0;
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267
268 /* (5) The number of disk I/O operations done */
91447636 269 an_acct.ac_io = encode_comp_t(r->ru_inblock + r->ru_oublock, 0);
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270
271 /* (6) The UID and GID of the process */
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272 safecred = kauth_cred_proc_ref(p);
273
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274 an_acct.ac_uid = kauth_cred_getruid(safecred);
275 an_acct.ac_gid = kauth_cred_getrgid(safecred);
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276
277 /* (7) The terminal from which the process was started */
2d21ac55
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278
279 sessp = proc_session(p);
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280 if ((p->p_flag & P_CONTROLT) && (sessp != SESSION_NULL) && ((tp = SESSION_TP(sessp)) != TTY_NULL)) {
281 tty_lock(tp);
282 an_acct.ac_tty = tp->t_dev;
283 tty_unlock(tp);
2d21ac55 284 }else
91447636 285 an_acct.ac_tty = NODEV;
1c79356b 286
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287 if (sessp != SESSION_NULL)
288 session_rele(sessp);
289
1c79356b 290 /* (8) The boolean flags that tell how the process terminated, etc. */
91447636 291 an_acct.ac_flag = p->p_acflag;
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292
293 /*
294 * Now, just write the accounting information to the file.
295 */
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296 if ((error = vnode_getwithref(vp)) == 0) {
297 error = vn_rdwr(UIO_WRITE, vp, (caddr_t)&an_acct, sizeof (an_acct),
b0d623f7 298 (off_t)0, UIO_SYSSPACE, IO_APPEND|IO_UNIT, safecred,
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299 (int *)0, p);
300 vnode_put(vp);
301 }
2d21ac55 302
0c530ab8 303 kauth_cred_unref(&safecred);
91447636 304 return (error);
1c79356b
A
305}
306
307/*
308 * Encode_comp_t converts from ticks in seconds and microseconds
309 * to ticks in 1/AHZ seconds. The encoding is described in
310 * Leffler, et al., on page 63.
311 */
312
313#define MANTSIZE 13 /* 13 bit mantissa. */
314#define EXPSIZE 3 /* Base 8 (3 bit) exponent. */
315#define MAXFRACT ((1 << MANTSIZE) - 1) /* Maximum fractional value. */
316
317comp_t
b0d623f7 318encode_comp_t(uint32_t s, uint32_t us)
1c79356b
A
319{
320 int exp, rnd;
321
322 exp = 0;
323 rnd = 0;
324 s *= AHZ;
325 s += us / (1000000 / AHZ); /* Maximize precision. */
326
327 while (s > MAXFRACT) {
328 rnd = s & (1 << (EXPSIZE - 1)); /* Round up? */
329 s >>= EXPSIZE; /* Base 8 exponent == 3 bit shift. */
330 exp++;
331 }
332
333 /* If we need to round up, do it (and handle overflow correctly). */
334 if (rnd && (++s > MAXFRACT)) {
335 s >>= EXPSIZE;
336 exp++;
337 }
338
339 /* Clean it up and polish it off. */
340 exp <<= MANTSIZE; /* Shift the exponent into place */
341 exp += s; /* and add on the mantissa. */
342 return (exp);
343}
344
b0d623f7 345/* XXX The acctwatch() thread need to be protected by a mutex instead. */
1c79356b 346void
2d21ac55 347acctwatch_funnel(void *a)
1c79356b
A
348{
349 thread_funnel_set(kernel_flock, TRUE);
350 acctwatch(a);
351 thread_funnel_set(kernel_flock, FALSE);
352}
353
354
355/*
356 * Periodically check the file system to see if accounting
357 * should be turned on or off. Beware the case where the vnode
358 * has been vgone()'d out from underneath us, e.g. when the file
359 * system containing the accounting file has been forcibly unmounted.
360 */
361/* ARGSUSED */
362void
91447636 363acctwatch(__unused void *a)
1c79356b 364{
2d21ac55 365 vfs_context_t ctx = vfs_context_current();
91447636
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366 struct vfs_attr va;
367
368 VFSATTR_INIT(&va);
369 VFSATTR_WANTED(&va, f_blocks);
370 VFSATTR_WANTED(&va, f_bavail);
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371
372 if (suspend_acctp != NULLVP) {
373 /*
374 * Resuming accounting when accounting is suspended, and the
375 * filesystem containing the suspended accounting file goes
376 * below a low watermark
377 */
378 if (suspend_acctp->v_type == VBAD) {
2d21ac55 379 (void) vn_close(suspend_acctp, FWRITE, vfs_context_kernel());
91447636 380 suspend_acctp = NULLVP;
1c79356b
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381 return;
382 }
2d21ac55 383 (void)vfs_getattr(suspend_acctp->v_mount, &va, ctx);
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384 if (va.f_bavail > acctresume * va.f_blocks / 100) {
385 acctp = suspend_acctp;
386 suspend_acctp = NULLVP;
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387 log(LOG_NOTICE, "Accounting resumed\n");
388 }
389 } else if (acctp != NULLVP) {
91447636
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390 /*
391 * Suspending accounting when accounting is currently active,
392 * and the filesystem containing the active accounting file
393 * goes over a high watermark
394 */
1c79356b 395 if (acctp->v_type == VBAD) {
2d21ac55 396 (void) vn_close(acctp, FWRITE, vfs_context_kernel());
1c79356b
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397 acctp = NULLVP;
398 return;
399 }
2d21ac55 400 (void)vfs_getattr(acctp->v_mount, &va, ctx);
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401 if (va.f_bavail <= acctsuspend * va.f_blocks / 100) {
402 suspend_acctp = acctp;
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403 acctp = NULLVP;
404 log(LOG_NOTICE, "Accounting suspended\n");
405 }
406 } else {
407 return;
408 }
409
410 timeout(acctwatch_funnel, NULL, acctchkfreq * hz);
411}