xref: /freebsd/sys/kern/kern_acct.c (revision bb92cd7bcd16f3f36cdbda18d8193619892715fb)
1df8bae1dSRodney W. Grimes /*-
2df57947fSPedro F. Giffuni  * SPDX-License-Identifier: BSD-4-Clause
3df57947fSPedro F. Giffuni  *
4df8bae1dSRodney W. Grimes  * Copyright (c) 1982, 1986, 1989, 1993
5df8bae1dSRodney W. Grimes  *	The Regents of the University of California.  All rights reserved.
6df8bae1dSRodney W. Grimes  * (c) UNIX System Laboratories, Inc.
7fcdc50ebSRobert Watson  * Copyright (c) 2005 Robert N. M. Watson
8fcdc50ebSRobert Watson  * All rights reserved.
9fcdc50ebSRobert Watson  *
10df8bae1dSRodney W. Grimes  * All or some portions of this file are derived from material licensed
11df8bae1dSRodney W. Grimes  * to the University of California by American Telephone and Telegraph
12df8bae1dSRodney W. Grimes  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
13df8bae1dSRodney W. Grimes  * the permission of UNIX System Laboratories, Inc.
14df8bae1dSRodney W. Grimes  *
15fcdc50ebSRobert Watson  * Redistribution and use in source and binary forms, with or without
16fcdc50ebSRobert Watson  * modification, are permitted provided that the following conditions
17fcdc50ebSRobert Watson  * are met:
18fcdc50ebSRobert Watson  * 1. Redistributions of source code must retain the above copyright
19fcdc50ebSRobert Watson  *    notice, this list of conditions and the following disclaimer.
20fcdc50ebSRobert Watson  * 2. Redistributions in binary form must reproduce the above copyright
21fcdc50ebSRobert Watson  *    notice, this list of conditions and the following disclaimer in the
22fcdc50ebSRobert Watson  *    documentation and/or other materials provided with the distribution.
2369a28758SEd Maste  * 3. Neither the name of the University nor the names of its contributors
24fcdc50ebSRobert Watson  *    may be used to endorse or promote products derived from this software
25fcdc50ebSRobert Watson  *    without specific prior written permission.
26fcdc50ebSRobert Watson  *
27fcdc50ebSRobert Watson  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28fcdc50ebSRobert Watson  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29fcdc50ebSRobert Watson  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30fcdc50ebSRobert Watson  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31fcdc50ebSRobert Watson  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32fcdc50ebSRobert Watson  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33fcdc50ebSRobert Watson  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34fcdc50ebSRobert Watson  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35fcdc50ebSRobert Watson  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36fcdc50ebSRobert Watson  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37fcdc50ebSRobert Watson  * SUCH DAMAGE.
38fcdc50ebSRobert Watson  *
3971909edeSRobert Watson  * Copyright (c) 1994 Christopher G. Demetriou
4071909edeSRobert Watson  *
41df8bae1dSRodney W. Grimes  * Redistribution and use in source and binary forms, with or without
42df8bae1dSRodney W. Grimes  * modification, are permitted provided that the following conditions
43df8bae1dSRodney W. Grimes  * are met:
44df8bae1dSRodney W. Grimes  * 1. Redistributions of source code must retain the above copyright
45df8bae1dSRodney W. Grimes  *    notice, this list of conditions and the following disclaimer.
46df8bae1dSRodney W. Grimes  * 2. Redistributions in binary form must reproduce the above copyright
47df8bae1dSRodney W. Grimes  *    notice, this list of conditions and the following disclaimer in the
48df8bae1dSRodney W. Grimes  *    documentation and/or other materials provided with the distribution.
49df8bae1dSRodney W. Grimes  * 3. All advertising materials mentioning features or use of this software
50df8bae1dSRodney W. Grimes  *    must display the following acknowledgement:
51df8bae1dSRodney W. Grimes  *	This product includes software developed by the University of
52df8bae1dSRodney W. Grimes  *	California, Berkeley and its contributors.
53df8bae1dSRodney W. Grimes  * 4. Neither the name of the University nor the names of its contributors
54df8bae1dSRodney W. Grimes  *    may be used to endorse or promote products derived from this software
55df8bae1dSRodney W. Grimes  *    without specific prior written permission.
56df8bae1dSRodney W. Grimes  *
57df8bae1dSRodney W. Grimes  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
58df8bae1dSRodney W. Grimes  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
59df8bae1dSRodney W. Grimes  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
60df8bae1dSRodney W. Grimes  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
61df8bae1dSRodney W. Grimes  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
62df8bae1dSRodney W. Grimes  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
63df8bae1dSRodney W. Grimes  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
64df8bae1dSRodney W. Grimes  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
65df8bae1dSRodney W. Grimes  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
66df8bae1dSRodney W. Grimes  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
67df8bae1dSRodney W. Grimes  * SUCH DAMAGE.
68df8bae1dSRodney W. Grimes  *
69c7d893deSDavid Greenman  *	@(#)kern_acct.c	8.1 (Berkeley) 6/14/93
70df8bae1dSRodney W. Grimes  */
71df8bae1dSRodney W. Grimes 
72677b542eSDavid E. O'Brien #include <sys/cdefs.h>
73677b542eSDavid E. O'Brien __FBSDID("$FreeBSD$");
74677b542eSDavid E. O'Brien 
75df8bae1dSRodney W. Grimes #include <sys/param.h>
760ad076d5SBruce Evans #include <sys/systm.h>
77b0864d13SJohn Baldwin #include <sys/acct.h>
78b0864d13SJohn Baldwin #include <sys/fcntl.h>
79b0864d13SJohn Baldwin #include <sys/kernel.h>
80505a1493SJohn Baldwin #include <sys/kthread.h>
8172de1b37SDiomidis Spinellis #include <sys/limits.h>
82fb919e4dSMark Murray #include <sys/lock.h>
832f304845SKonstantin Belousov #include <sys/malloc.h>
84df8bae1dSRodney W. Grimes #include <sys/mount.h>
85b0864d13SJohn Baldwin #include <sys/mutex.h>
86c7d893deSDavid Greenman #include <sys/namei.h>
87acd3428bSRobert Watson #include <sys/priv.h>
88b0864d13SJohn Baldwin #include <sys/proc.h>
89c7d893deSDavid Greenman #include <sys/resourcevar.h>
90505a1493SJohn Baldwin #include <sys/sched.h>
91b0864d13SJohn Baldwin #include <sys/sx.h>
92b0864d13SJohn Baldwin #include <sys/sysctl.h>
93b0864d13SJohn Baldwin #include <sys/sysent.h>
94b0864d13SJohn Baldwin #include <sys/syslog.h>
95b0864d13SJohn Baldwin #include <sys/sysproto.h>
96c7d893deSDavid Greenman #include <sys/tty.h>
97b0864d13SJohn Baldwin #include <sys/vnode.h>
98df8bae1dSRodney W. Grimes 
99aed55708SRobert Watson #include <security/mac/mac_framework.h>
100aed55708SRobert Watson 
10169921123SKonstantin Belousov _Static_assert(sizeof(struct acctv3) - offsetof(struct acctv3, ac_trailer) ==
10269921123SKonstantin Belousov     sizeof(struct acctv2) - offsetof(struct acctv2, ac_trailer), "trailer");
10369921123SKonstantin Belousov _Static_assert(sizeof(struct acctv3) - offsetof(struct acctv3, ac_len2) ==
10469921123SKonstantin Belousov     sizeof(struct acctv2) - offsetof(struct acctv2, ac_len2), "len2");
10569921123SKonstantin Belousov 
106df8bae1dSRodney W. Grimes /*
107c7d893deSDavid Greenman  * The routines implemented in this file are described in:
108c7d893deSDavid Greenman  *      Leffler, et al.: The Design and Implementation of the 4.3BSD
109c7d893deSDavid Greenman  *	    UNIX Operating System (Addison Welley, 1989)
110c7d893deSDavid Greenman  * on pages 62-63.
111fdbe5babSDiomidis Spinellis  * On May 2007 the historic 3 bits base 8 exponent, 13 bit fraction
112fdbe5babSDiomidis Spinellis  * compt_t representation described in the above reference was replaced
113fdbe5babSDiomidis Spinellis  * with that of IEEE-754 floats.
114c7d893deSDavid Greenman  *
115c7d893deSDavid Greenman  * Arguably, to simplify accounting operations, this mechanism should
116c7d893deSDavid Greenman  * be replaced by one in which an accounting log file (similar to /dev/klog)
117c7d893deSDavid Greenman  * is read by a user process, etc.  However, that has its own problems.
118df8bae1dSRodney W. Grimes  */
119df8bae1dSRodney W. Grimes 
120fdbe5babSDiomidis Spinellis /* Floating point definitions from <float.h>. */
121fdbe5babSDiomidis Spinellis #define FLT_MANT_DIG    24              /* p */
122fdbe5babSDiomidis Spinellis #define FLT_MAX_EXP     128             /* emax */
123fdbe5babSDiomidis Spinellis 
124df8bae1dSRodney W. Grimes /*
125c7d893deSDavid Greenman  * Internal accounting functions.
126c7d893deSDavid Greenman  * The former's operation is described in Leffler, et al., and the latter
127c7d893deSDavid Greenman  * was provided by UCB with the 4.4BSD-Lite release
128df8bae1dSRodney W. Grimes  */
129fdbe5babSDiomidis Spinellis static uint32_t	encode_timeval(struct timeval);
130fdbe5babSDiomidis Spinellis static uint32_t	encode_long(long);
131505a1493SJohn Baldwin static void	acctwatch(void);
132505a1493SJohn Baldwin static void	acct_thread(void *);
133b8cb2346SJohn Baldwin static int	acct_disable(struct thread *, int);
134ab36c067SJustin T. Gibbs 
135ab36c067SJustin T. Gibbs /*
1365b606744SJohan Karlsson  * Accounting vnode pointer, saved vnode pointer, and flags for each.
13771909edeSRobert Watson  * acct_sx protects against changes to the active vnode and credentials
13871909edeSRobert Watson  * while accounting records are being committed to disk.
139c7d893deSDavid Greenman  */
140101581b0SRobert Watson static int		 acct_configured;
14171909edeSRobert Watson static int		 acct_suspended;
14271909edeSRobert Watson static struct vnode	*acct_vp;
14371909edeSRobert Watson static struct ucred	*acct_cred;
14471909edeSRobert Watson static int		 acct_flags;
14571909edeSRobert Watson static struct sx	 acct_sx;
146df8bae1dSRodney W. Grimes 
14771909edeSRobert Watson SX_SYSINIT(acct, &acct_sx, "acct_sx");
1484f39d5d5SAndrew R. Reiter 
149df8bae1dSRodney W. Grimes /*
150505a1493SJohn Baldwin  * State of the accounting kthread.
151505a1493SJohn Baldwin  */
152505a1493SJohn Baldwin static int		 acct_state;
153505a1493SJohn Baldwin 
154505a1493SJohn Baldwin #define	ACCT_RUNNING	1	/* Accounting kthread is running. */
155505a1493SJohn Baldwin #define	ACCT_EXITREQ	2	/* Accounting kthread should exit. */
156505a1493SJohn Baldwin 
157505a1493SJohn Baldwin /*
158df8bae1dSRodney W. Grimes  * Values associated with enabling and disabling accounting
159df8bae1dSRodney W. Grimes  */
16087b6de2bSPoul-Henning Kamp static int acctsuspend = 2;	/* stop accounting when < 2% free space left */
16187b6de2bSPoul-Henning Kamp SYSCTL_INT(_kern, OID_AUTO, acct_suspend, CTLFLAG_RW,
16247fdd692SNeil Blakey-Milner 	&acctsuspend, 0, "percentage of free disk space below which accounting stops");
16387b6de2bSPoul-Henning Kamp 
16487b6de2bSPoul-Henning Kamp static int acctresume = 4;	/* resume when free space risen to > 4% */
16587b6de2bSPoul-Henning Kamp SYSCTL_INT(_kern, OID_AUTO, acct_resume, CTLFLAG_RW,
16647fdd692SNeil Blakey-Milner 	&acctresume, 0, "percentage of free disk space above which accounting resumes");
16787b6de2bSPoul-Henning Kamp 
16887b6de2bSPoul-Henning Kamp static int acctchkfreq = 15;	/* frequency (in seconds) to check space */
169222fdf4bSJohn Baldwin 
170222fdf4bSJohn Baldwin static int
171222fdf4bSJohn Baldwin sysctl_acct_chkfreq(SYSCTL_HANDLER_ARGS)
172222fdf4bSJohn Baldwin {
173222fdf4bSJohn Baldwin 	int error, value;
174222fdf4bSJohn Baldwin 
175222fdf4bSJohn Baldwin 	/* Write out the old value. */
176222fdf4bSJohn Baldwin 	error = SYSCTL_OUT(req, &acctchkfreq, sizeof(int));
177222fdf4bSJohn Baldwin 	if (error || req->newptr == NULL)
178222fdf4bSJohn Baldwin 		return (error);
179222fdf4bSJohn Baldwin 
180222fdf4bSJohn Baldwin 	/* Read in and verify the new value. */
181222fdf4bSJohn Baldwin 	error = SYSCTL_IN(req, &value, sizeof(int));
182222fdf4bSJohn Baldwin 	if (error)
183222fdf4bSJohn Baldwin 		return (error);
184222fdf4bSJohn Baldwin 	if (value <= 0)
185222fdf4bSJohn Baldwin 		return (EINVAL);
186222fdf4bSJohn Baldwin 	acctchkfreq = value;
187222fdf4bSJohn Baldwin 	return (0);
188222fdf4bSJohn Baldwin }
1897029da5cSPawel Biernacki SYSCTL_PROC(_kern, OID_AUTO, acct_chkfreq,
190fe27f1dbSAlexander Motin     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, &acctchkfreq, 0,
1917029da5cSPawel Biernacki     sysctl_acct_chkfreq, "I",
192222fdf4bSJohn Baldwin     "frequency for checking the free space");
193df8bae1dSRodney W. Grimes 
194101581b0SRobert Watson SYSCTL_INT(_kern, OID_AUTO, acct_configured, CTLFLAG_RD, &acct_configured, 0,
195101581b0SRobert Watson 	"Accounting configured or not");
196101581b0SRobert Watson 
19771909edeSRobert Watson SYSCTL_INT(_kern, OID_AUTO, acct_suspended, CTLFLAG_RD, &acct_suspended, 0,
19871909edeSRobert Watson 	"Accounting suspended or not");
19971909edeSRobert Watson 
200df8bae1dSRodney W. Grimes /*
2010c14ff0eSRobert Watson  * Accounting system call.  Written based on the specification and previous
2020c14ff0eSRobert Watson  * implementation done by Mark Tinguely.
203df8bae1dSRodney W. Grimes  */
204c7d893deSDavid Greenman int
2058451d0ddSKip Macy sys_acct(struct thread *td, struct acct_args *uap)
206c7d893deSDavid Greenman {
207c7d893deSDavid Greenman 	struct nameidata nd;
2089bb84c23SKonstantin Belousov 	int error, flags, replacing;
209c7d893deSDavid Greenman 
210acd3428bSRobert Watson 	error = priv_check(td, PRIV_ACCT);
211797f2d22SPoul-Henning Kamp 	if (error)
21216e7bc7bSJohn Baldwin 		return (error);
213c7d893deSDavid Greenman 
214c7d893deSDavid Greenman 	/*
215c7d893deSDavid Greenman 	 * If accounting is to be started to a file, open that file for
21611178ee4SJohn Baldwin 	 * appending and make sure it's a 'normal'.
217c7d893deSDavid Greenman 	 */
218d1e405c5SAlfred Perlstein 	if (uap->path != NULL) {
2197e1d3eefSMateusz Guzik 		NDINIT(&nd, LOOKUP, NOFOLLOW | AUDITVNODE1, UIO_USERSPACE,
2207e1d3eefSMateusz Guzik 		    uap->path);
22192da2e76SJohan Karlsson 		flags = FWRITE | O_APPEND;
2229e223287SKonstantin Belousov 		error = vn_open(&nd, &flags, 0, NULL);
223797f2d22SPoul-Henning Kamp 		if (error)
22411178ee4SJohn Baldwin 			return (error);
225*bb92cd7bSMateusz Guzik 		NDFREE_PNBUF(&nd);
226e5e820fdSRobert Watson #ifdef MAC
22730d239bcSRobert Watson 		error = mac_system_check_acct(td->td_ucred, nd.ni_vp);
228e5e820fdSRobert Watson 		if (error) {
229b249ce48SMateusz Guzik 			VOP_UNLOCK(nd.ni_vp);
230e5e820fdSRobert Watson 			vn_close(nd.ni_vp, flags, td->td_ucred, td);
23111178ee4SJohn Baldwin 			return (error);
232e5e820fdSRobert Watson 		}
233e5e820fdSRobert Watson #endif
234b249ce48SMateusz Guzik 		VOP_UNLOCK(nd.ni_vp);
235c7d893deSDavid Greenman 		if (nd.ni_vp->v_type != VREG) {
2365b606744SJohan Karlsson 			vn_close(nd.ni_vp, flags, td->td_ucred, td);
23711178ee4SJohn Baldwin 			return (EACCES);
238c7d893deSDavid Greenman 		}
239e5e820fdSRobert Watson #ifdef MAC
240e5e820fdSRobert Watson 	} else {
24130d239bcSRobert Watson 		error = mac_system_check_acct(td->td_ucred, NULL);
242e5e820fdSRobert Watson 		if (error)
24311178ee4SJohn Baldwin 			return (error);
244e5e820fdSRobert Watson #endif
245c7d893deSDavid Greenman 	}
246c7d893deSDavid Greenman 
24771909edeSRobert Watson 	/*
24871909edeSRobert Watson 	 * Disallow concurrent access to the accounting vnode while we swap
24971909edeSRobert Watson 	 * it out, in order to prevent access after close.
25071909edeSRobert Watson 	 */
25171909edeSRobert Watson 	sx_xlock(&acct_sx);
25201e3f3aeSBruce Evans 
253c7d893deSDavid Greenman 	/*
254b8cb2346SJohn Baldwin 	 * Don't log spurious disable/enable messages if we are
255b8cb2346SJohn Baldwin 	 * switching from one accounting file to another due to log
256b8cb2346SJohn Baldwin 	 * rotation.
257b8cb2346SJohn Baldwin 	 */
258b8cb2346SJohn Baldwin 	replacing = (acct_vp != NULL && uap->path != NULL);
259b8cb2346SJohn Baldwin 
260b8cb2346SJohn Baldwin 	/*
261c7d893deSDavid Greenman 	 * If accounting was previously enabled, kill the old space-watcher,
26271909edeSRobert Watson 	 * close the file, and (if no new file was specified, leave).  Reset
26371909edeSRobert Watson 	 * the suspended state regardless of whether accounting remains
26471909edeSRobert Watson 	 * enabled.
265c7d893deSDavid Greenman 	 */
26671909edeSRobert Watson 	acct_suspended = 0;
2675050aa86SKonstantin Belousov 	if (acct_vp != NULL)
268b8cb2346SJohn Baldwin 		error = acct_disable(td, !replacing);
269d1e405c5SAlfred Perlstein 	if (uap->path == NULL) {
270505a1493SJohn Baldwin 		if (acct_state & ACCT_RUNNING) {
271505a1493SJohn Baldwin 			acct_state |= ACCT_EXITREQ;
272505a1493SJohn Baldwin 			wakeup(&acct_state);
273505a1493SJohn Baldwin 		}
27471909edeSRobert Watson 		sx_xunlock(&acct_sx);
27511178ee4SJohn Baldwin 		return (error);
276b4dcc46aSAndrew R. Reiter 	}
277c7d893deSDavid Greenman 
278c7d893deSDavid Greenman 	/*
279c7d893deSDavid Greenman 	 * Save the new accounting file vnode, and schedule the new
280c7d893deSDavid Greenman 	 * free space watcher.
281c7d893deSDavid Greenman 	 */
28271909edeSRobert Watson 	acct_vp = nd.ni_vp;
28371909edeSRobert Watson 	acct_cred = crhold(td->td_ucred);
28471909edeSRobert Watson 	acct_flags = flags;
285505a1493SJohn Baldwin 	if (acct_state & ACCT_RUNNING)
286505a1493SJohn Baldwin 		acct_state &= ~ACCT_EXITREQ;
287505a1493SJohn Baldwin 	else {
288505a1493SJohn Baldwin 		/*
289505a1493SJohn Baldwin 		 * Try to start up an accounting kthread.  We may start more
290505a1493SJohn Baldwin 		 * than one, but if so the extras will commit suicide as
291505a1493SJohn Baldwin 		 * soon as they start up.
292505a1493SJohn Baldwin 		 */
2933745c395SJulian Elischer 		error = kproc_create(acct_thread, NULL, NULL, 0, 0,
294505a1493SJohn Baldwin 		    "accounting");
295505a1493SJohn Baldwin 		if (error) {
2964a3c4f41SMateusz Guzik 			(void) acct_disable(td, 0);
297505a1493SJohn Baldwin 			sx_xunlock(&acct_sx);
298505a1493SJohn Baldwin 			log(LOG_NOTICE, "Unable to start accounting thread\n");
29911178ee4SJohn Baldwin 			return (error);
300505a1493SJohn Baldwin 		}
301505a1493SJohn Baldwin 	}
302101581b0SRobert Watson 	acct_configured = 1;
30371909edeSRobert Watson 	sx_xunlock(&acct_sx);
304b8cb2346SJohn Baldwin 	if (!replacing)
30548719ca7SBosko Milekic 		log(LOG_NOTICE, "Accounting enabled\n");
306c7d893deSDavid Greenman 	return (error);
307c7d893deSDavid Greenman }
308c7d893deSDavid Greenman 
309c7d893deSDavid Greenman /*
310505a1493SJohn Baldwin  * Disable currently in-progress accounting by closing the vnode, dropping
311505a1493SJohn Baldwin  * our reference to the credential, and clearing the vnode's flags.
312505a1493SJohn Baldwin  */
313505a1493SJohn Baldwin static int
314b8cb2346SJohn Baldwin acct_disable(struct thread *td, int logging)
315505a1493SJohn Baldwin {
316505a1493SJohn Baldwin 	int error;
317505a1493SJohn Baldwin 
318505a1493SJohn Baldwin 	sx_assert(&acct_sx, SX_XLOCKED);
319505a1493SJohn Baldwin 	error = vn_close(acct_vp, acct_flags, acct_cred, td);
320505a1493SJohn Baldwin 	crfree(acct_cred);
321101581b0SRobert Watson 	acct_configured = 0;
322505a1493SJohn Baldwin 	acct_vp = NULL;
323505a1493SJohn Baldwin 	acct_cred = NULL;
324505a1493SJohn Baldwin 	acct_flags = 0;
325b8cb2346SJohn Baldwin 	if (logging)
326505a1493SJohn Baldwin 		log(LOG_NOTICE, "Accounting disabled\n");
327505a1493SJohn Baldwin 	return (error);
328505a1493SJohn Baldwin }
329505a1493SJohn Baldwin 
330505a1493SJohn Baldwin /*
331c7d893deSDavid Greenman  * Write out process accounting information, on process exit.
332c7d893deSDavid Greenman  * Data to be written out is specified in Leffler, et al.
333c7d893deSDavid Greenman  * and are enumerated below.  (They're also noted in the system
334c7d893deSDavid Greenman  * "acct.h" header file.)
335c7d893deSDavid Greenman  */
336c7d893deSDavid Greenman int
33771909edeSRobert Watson acct_process(struct thread *td)
338c7d893deSDavid Greenman {
33969921123SKonstantin Belousov 	struct acctv3 acct;
340c7d893deSDavid Greenman 	struct timeval ut, st, tmp;
34101e3f3aeSBruce Evans 	struct proc *p;
3421c4bcd05SJeff Roberson 	struct rusage ru;
3435050aa86SKonstantin Belousov 	int t, ret;
3444f39d5d5SAndrew R. Reiter 
3452b05b557SRobert Watson 	/*
3462b05b557SRobert Watson 	 * Lockless check of accounting condition before doing the hard
3472b05b557SRobert Watson 	 * work.
3482b05b557SRobert Watson 	 */
34971909edeSRobert Watson 	if (acct_vp == NULL || acct_suspended)
3502b05b557SRobert Watson 		return (0);
3512b05b557SRobert Watson 
35290959dd1SMark Johnston 	memset(&acct, 0, sizeof(acct));
35390959dd1SMark Johnston 
35471909edeSRobert Watson 	sx_slock(&acct_sx);
355c7d893deSDavid Greenman 
3562b05b557SRobert Watson 	/*
3572b05b557SRobert Watson 	 * If accounting isn't enabled, don't bother.  Have to check again
3582b05b557SRobert Watson 	 * once we own the lock in case we raced with disabling of accounting
3592b05b557SRobert Watson 	 * by another thread.
3602b05b557SRobert Watson 	 */
36171909edeSRobert Watson 	if (acct_vp == NULL || acct_suspended) {
36271909edeSRobert Watson 		sx_sunlock(&acct_sx);
363c7d893deSDavid Greenman 		return (0);
3644f39d5d5SAndrew R. Reiter 	}
365c7d893deSDavid Greenman 
36601e3f3aeSBruce Evans 	p = td->td_proc;
3679bb84c23SKonstantin Belousov 	td->td_pflags2 |= TDP2_ACCT;
36801e3f3aeSBruce Evans 
369c7d893deSDavid Greenman 	/*
370c7d893deSDavid Greenman 	 * Get process accounting information.
371c7d893deSDavid Greenman 	 */
372c7d893deSDavid Greenman 
37340572ab3SEd Schouten 	sx_slock(&proctree_lock);
3747e653dbdSJohn Baldwin 	PROC_LOCK(p);
37540572ab3SEd Schouten 
37640572ab3SEd Schouten 	/* (1) The terminal from which the process was started */
37740572ab3SEd Schouten 	if ((p->p_flag & P_CONTROLT) && p->p_pgrp->pg_session->s_ttyp)
37840572ab3SEd Schouten 		acct.ac_tty = tty_udev(p->p_pgrp->pg_session->s_ttyp);
37940572ab3SEd Schouten 	else
38040572ab3SEd Schouten 		acct.ac_tty = NODEV;
38140572ab3SEd Schouten 	sx_sunlock(&proctree_lock);
38240572ab3SEd Schouten 
38340572ab3SEd Schouten 	/* (2) The name of the command that ran */
384c7d893deSDavid Greenman 	bcopy(p->p_comm, acct.ac_comm, sizeof acct.ac_comm);
385c7d893deSDavid Greenman 
38640572ab3SEd Schouten 	/* (3) The amount of user and system time that was used */
387a1fe14bcSAttilio Rao 	rufetchcalc(p, &ru, &ut, &st);
388fdbe5babSDiomidis Spinellis 	acct.ac_utime = encode_timeval(ut);
389fdbe5babSDiomidis Spinellis 	acct.ac_stime = encode_timeval(st);
390c7d893deSDavid Greenman 
39140572ab3SEd Schouten 	/* (4) The elapsed time the command ran (and its starting time) */
392584b675eSKonstantin Belousov 	getboottime(&tmp);
39387ccef7bSDag-Erling Smørgrav 	timevaladd(&tmp, &p->p_stats->p_start);
39487ccef7bSDag-Erling Smørgrav 	acct.ac_btime = tmp.tv_sec;
39587ccef7bSDag-Erling Smørgrav 	microuptime(&tmp);
396c7d893deSDavid Greenman 	timevalsub(&tmp, &p->p_stats->p_start);
397fdbe5babSDiomidis Spinellis 	acct.ac_etime = encode_timeval(tmp);
398c7d893deSDavid Greenman 
39940572ab3SEd Schouten 	/* (5) The average amount of memory used */
400c7d893deSDavid Greenman 	tmp = ut;
401c7d893deSDavid Greenman 	timevaladd(&tmp, &st);
402fdbe5babSDiomidis Spinellis 	/* Convert tmp (i.e. u + s) into hz units to match ru_i*. */
403c7d893deSDavid Greenman 	t = tmp.tv_sec * hz + tmp.tv_usec / tick;
404c7d893deSDavid Greenman 	if (t)
4051c4bcd05SJeff Roberson 		acct.ac_mem = encode_long((ru.ru_ixrss + ru.ru_idrss +
4061c4bcd05SJeff Roberson 		    + ru.ru_isrss) / t);
407c7d893deSDavid Greenman 	else
408c7d893deSDavid Greenman 		acct.ac_mem = 0;
409c7d893deSDavid Greenman 
41040572ab3SEd Schouten 	/* (6) The number of disk I/O operations done */
4111c4bcd05SJeff Roberson 	acct.ac_io = encode_long(ru.ru_inblock + ru.ru_oublock);
412c7d893deSDavid Greenman 
41340572ab3SEd Schouten 	/* (7) The UID and GID of the process */
414b1fc0ec1SRobert Watson 	acct.ac_uid = p->p_ucred->cr_ruid;
415b1fc0ec1SRobert Watson 	acct.ac_gid = p->p_ucred->cr_rgid;
416c7d893deSDavid Greenman 
417c7d893deSDavid Greenman 	/* (8) The boolean flags that tell how the process terminated, etc. */
418fdbe5babSDiomidis Spinellis 	acct.ac_flagx = p->p_acflag;
419c7d893deSDavid Greenman 
4209bb84c23SKonstantin Belousov 	PROC_UNLOCK(p);
4219bb84c23SKonstantin Belousov 
422fdbe5babSDiomidis Spinellis 	/* Setup ancillary structure fields. */
423fdbe5babSDiomidis Spinellis 	acct.ac_flagx |= ANVER;
424fdbe5babSDiomidis Spinellis 	acct.ac_zero = 0;
42569921123SKonstantin Belousov 	acct.ac_version = 3;
426fdbe5babSDiomidis Spinellis 	acct.ac_len = acct.ac_len2 = sizeof(acct);
427fdbe5babSDiomidis Spinellis 
428c7d893deSDavid Greenman 	/*
42901e3f3aeSBruce Evans 	 * Write the accounting information to the file.
43001e3f3aeSBruce Evans 	 */
43171909edeSRobert Watson 	ret = vn_rdwr(UIO_WRITE, acct_vp, (caddr_t)&acct, sizeof (acct),
43271909edeSRobert Watson 	    (off_t)0, UIO_SYSSPACE, IO_APPEND|IO_UNIT, acct_cred, NOCRED,
43301ed1748SKonstantin Belousov 	    NULL, td);
43471909edeSRobert Watson 	sx_sunlock(&acct_sx);
4359bb84c23SKonstantin Belousov 	td->td_pflags2 &= ~TDP2_ACCT;
4364f39d5d5SAndrew R. Reiter 	return (ret);
437c7d893deSDavid Greenman }
438c7d893deSDavid Greenman 
439fdbe5babSDiomidis Spinellis /* FLOAT_CONVERSION_START (Regression testing; don't remove this line.) */
440fdbe5babSDiomidis Spinellis 
441fdbe5babSDiomidis Spinellis /* Convert timevals and longs into IEEE-754 bit patterns. */
442fdbe5babSDiomidis Spinellis 
443fdbe5babSDiomidis Spinellis /* Mantissa mask (MSB is implied, so subtract 1). */
444fdbe5babSDiomidis Spinellis #define MANT_MASK ((1 << (FLT_MANT_DIG - 1)) - 1)
445fdbe5babSDiomidis Spinellis 
446c7d893deSDavid Greenman /*
447fdbe5babSDiomidis Spinellis  * We calculate integer values to a precision of approximately
448fdbe5babSDiomidis Spinellis  * 28 bits.
449fdbe5babSDiomidis Spinellis  * This is high-enough precision to fill the 24 float bits
450fdbe5babSDiomidis Spinellis  * and low-enough to avoid overflowing the 32 int bits.
451c7d893deSDavid Greenman  */
452fdbe5babSDiomidis Spinellis #define CALC_BITS 28
453c7d893deSDavid Greenman 
454fdbe5babSDiomidis Spinellis /* log_2(1000000). */
455fdbe5babSDiomidis Spinellis #define LOG2_1M 20
456c7d893deSDavid Greenman 
457fdbe5babSDiomidis Spinellis /*
458fdbe5babSDiomidis Spinellis  * Convert the elements of a timeval into a 32-bit word holding
459fdbe5babSDiomidis Spinellis  * the bits of a IEEE-754 float.
460fdbe5babSDiomidis Spinellis  * The float value represents the timeval's value in microsecond units.
461fdbe5babSDiomidis Spinellis  */
462fdbe5babSDiomidis Spinellis static uint32_t
463fdbe5babSDiomidis Spinellis encode_timeval(struct timeval tv)
464c7d893deSDavid Greenman {
465fdbe5babSDiomidis Spinellis 	int log2_s;
466d75a7880SEnji Cooper 	int val, exp;	/* Unnormalized value and exponent */
467d75a7880SEnji Cooper 	int norm_exp;	/* Normalized exponent */
468fdbe5babSDiomidis Spinellis 	int shift;
469c7d893deSDavid Greenman 
470fdbe5babSDiomidis Spinellis 	/*
471fdbe5babSDiomidis Spinellis 	 * First calculate value and exponent to about CALC_BITS precision.
472fdbe5babSDiomidis Spinellis 	 * Note that the following conditionals have been ordered so that
473fdbe5babSDiomidis Spinellis 	 * the most common cases appear first.
474fdbe5babSDiomidis Spinellis 	 */
475fdbe5babSDiomidis Spinellis 	if (tv.tv_sec == 0) {
476fdbe5babSDiomidis Spinellis 		if (tv.tv_usec == 0)
477fdbe5babSDiomidis Spinellis 			return (0);
478d75a7880SEnji Cooper 		exp = 0;
479fdbe5babSDiomidis Spinellis 		val = tv.tv_usec;
480fdbe5babSDiomidis Spinellis 	} else {
481fdbe5babSDiomidis Spinellis 		/*
482fdbe5babSDiomidis Spinellis 		 * Calculate the value to a precision of approximately
483fdbe5babSDiomidis Spinellis 		 * CALC_BITS.
484fdbe5babSDiomidis Spinellis 		 */
485fdbe5babSDiomidis Spinellis 		log2_s = fls(tv.tv_sec) - 1;
486fdbe5babSDiomidis Spinellis 		if (log2_s + LOG2_1M < CALC_BITS) {
487d75a7880SEnji Cooper 			exp = 0;
488fdbe5babSDiomidis Spinellis 			val = 1000000 * tv.tv_sec + tv.tv_usec;
489fdbe5babSDiomidis Spinellis 		} else {
490d75a7880SEnji Cooper 			exp = log2_s + LOG2_1M - CALC_BITS;
49160ae52f7SEd Schouten 			val = (unsigned int)(((uint64_t)1000000 * tv.tv_sec +
492d75a7880SEnji Cooper 			    tv.tv_usec) >> exp);
493fdbe5babSDiomidis Spinellis 		}
494fdbe5babSDiomidis Spinellis 	}
495fdbe5babSDiomidis Spinellis 	/* Now normalize and pack the value into an IEEE-754 float. */
496d75a7880SEnji Cooper 	norm_exp = fls(val) - 1;
497d75a7880SEnji Cooper 	shift = FLT_MANT_DIG - norm_exp - 1;
498fdbe5babSDiomidis Spinellis #ifdef ACCT_DEBUG
499fdbe5babSDiomidis Spinellis 	printf("val=%d exp=%d shift=%d log2(val)=%d\n",
500d75a7880SEnji Cooper 	    val, exp, shift, norm_exp);
501d75a7880SEnji Cooper 	printf("exp=%x mant=%x\n", FLT_MAX_EXP - 1 + exp + norm_exp,
502fdbe5babSDiomidis Spinellis 	    ((shift > 0 ? (val << shift) : (val >> -shift)) & MANT_MASK));
503fdbe5babSDiomidis Spinellis #endif
504d75a7880SEnji Cooper 	return (((FLT_MAX_EXP - 1 + exp + norm_exp) << (FLT_MANT_DIG - 1)) |
505fdbe5babSDiomidis Spinellis 	    ((shift > 0 ? val << shift : val >> -shift) & MANT_MASK));
506c7d893deSDavid Greenman }
507c7d893deSDavid Greenman 
508fdbe5babSDiomidis Spinellis /*
509fdbe5babSDiomidis Spinellis  * Convert a non-negative long value into the bit pattern of
510fdbe5babSDiomidis Spinellis  * an IEEE-754 float value.
511fdbe5babSDiomidis Spinellis  */
512fdbe5babSDiomidis Spinellis static uint32_t
513fdbe5babSDiomidis Spinellis encode_long(long val)
514fdbe5babSDiomidis Spinellis {
515d75a7880SEnji Cooper 	int norm_exp;	/* Normalized exponent */
516fdbe5babSDiomidis Spinellis 	int shift;
517fdbe5babSDiomidis Spinellis 
518fdbe5babSDiomidis Spinellis 	if (val == 0)
519fdbe5babSDiomidis Spinellis 		return (0);
52072de1b37SDiomidis Spinellis 	if (val < 0) {
52172de1b37SDiomidis Spinellis 		log(LOG_NOTICE,
522d5b6981eSDiomidis Spinellis 		    "encode_long: negative value %ld in accounting record\n",
52372de1b37SDiomidis Spinellis 		    val);
52472de1b37SDiomidis Spinellis 		val = LONG_MAX;
52572de1b37SDiomidis Spinellis 	}
526d75a7880SEnji Cooper 	norm_exp = fls(val) - 1;
527d75a7880SEnji Cooper 	shift = FLT_MANT_DIG - norm_exp - 1;
528fdbe5babSDiomidis Spinellis #ifdef ACCT_DEBUG
529fdbe5babSDiomidis Spinellis 	printf("val=%d shift=%d log2(val)=%d\n",
530d75a7880SEnji Cooper 	    val, shift, norm_exp);
531d75a7880SEnji Cooper 	printf("exp=%x mant=%x\n", FLT_MAX_EXP - 1 + exp + norm_exp,
532fdbe5babSDiomidis Spinellis 	    ((shift > 0 ? (val << shift) : (val >> -shift)) & MANT_MASK));
533fdbe5babSDiomidis Spinellis #endif
534d75a7880SEnji Cooper 	return (((FLT_MAX_EXP - 1 + norm_exp) << (FLT_MANT_DIG - 1)) |
535fdbe5babSDiomidis Spinellis 	    ((shift > 0 ? val << shift : val >> -shift) & MANT_MASK));
536c7d893deSDavid Greenman }
537c7d893deSDavid Greenman 
538fdbe5babSDiomidis Spinellis /* FLOAT_CONVERSION_END (Regression testing; don't remove this line.) */
539c7d893deSDavid Greenman 
540c7d893deSDavid Greenman /*
541c7d893deSDavid Greenman  * Periodically check the filesystem to see if accounting
542c7d893deSDavid Greenman  * should be turned on or off.  Beware the case where the vnode
543c7d893deSDavid Greenman  * has been vgone()'d out from underneath us, e.g. when the file
544c7d893deSDavid Greenman  * system containing the accounting file has been forcibly unmounted.
545c7d893deSDavid Greenman  */
546df8bae1dSRodney W. Grimes /* ARGSUSED */
54787b6de2bSPoul-Henning Kamp static void
548505a1493SJohn Baldwin acctwatch(void)
549df8bae1dSRodney W. Grimes {
5502f304845SKonstantin Belousov 	struct statfs *sp;
551df8bae1dSRodney W. Grimes 
552505a1493SJohn Baldwin 	sx_assert(&acct_sx, SX_XLOCKED);
553505a1493SJohn Baldwin 
554505a1493SJohn Baldwin 	/*
555505a1493SJohn Baldwin 	 * If accounting was disabled before our kthread was scheduled,
556505a1493SJohn Baldwin 	 * then acct_vp might be NULL.  If so, just ask our kthread to
557505a1493SJohn Baldwin 	 * exit and return.
558505a1493SJohn Baldwin 	 */
559505a1493SJohn Baldwin 	if (acct_vp == NULL) {
560505a1493SJohn Baldwin 		acct_state |= ACCT_EXITREQ;
561c7d893deSDavid Greenman 		return;
562c7d893deSDavid Greenman 	}
563505a1493SJohn Baldwin 
564505a1493SJohn Baldwin 	/*
565505a1493SJohn Baldwin 	 * If our vnode is no longer valid, tear it down and signal the
566505a1493SJohn Baldwin 	 * accounting thread to die.
567505a1493SJohn Baldwin 	 */
568505a1493SJohn Baldwin 	if (acct_vp->v_type == VBAD) {
569b8cb2346SJohn Baldwin 		(void) acct_disable(NULL, 1);
570505a1493SJohn Baldwin 		acct_state |= ACCT_EXITREQ;
571505a1493SJohn Baldwin 		return;
572505a1493SJohn Baldwin 	}
573505a1493SJohn Baldwin 
57471909edeSRobert Watson 	/*
57571909edeSRobert Watson 	 * Stopping here is better than continuing, maybe it will be VBAD
57671909edeSRobert Watson 	 * next time around.
57771909edeSRobert Watson 	 */
5782f304845SKonstantin Belousov 	sp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
5792f304845SKonstantin Belousov 	if (VFS_STATFS(acct_vp->v_mount, sp) < 0) {
5802f304845SKonstantin Belousov 		free(sp, M_STATFS);
58171909edeSRobert Watson 		return;
5822f304845SKonstantin Belousov 	}
58371909edeSRobert Watson 	if (acct_suspended) {
5842f304845SKonstantin Belousov 		if (sp->f_bavail > (int64_t)(acctresume * sp->f_blocks /
58571909edeSRobert Watson 		    100)) {
58671909edeSRobert Watson 			acct_suspended = 0;
587df8bae1dSRodney W. Grimes 			log(LOG_NOTICE, "Accounting resumed\n");
588df8bae1dSRodney W. Grimes 		}
589996c772fSJohn Dyson 	} else {
5902f304845SKonstantin Belousov 		if (sp->f_bavail <= (int64_t)(acctsuspend * sp->f_blocks /
59171909edeSRobert Watson 		    100)) {
59271909edeSRobert Watson 			acct_suspended = 1;
593df8bae1dSRodney W. Grimes 			log(LOG_NOTICE, "Accounting suspended\n");
594df8bae1dSRodney W. Grimes 		}
595996c772fSJohn Dyson 	}
5962f304845SKonstantin Belousov 	free(sp, M_STATFS);
597505a1493SJohn Baldwin }
598505a1493SJohn Baldwin 
599505a1493SJohn Baldwin /*
600505a1493SJohn Baldwin  * The main loop for the dedicated kernel thread that periodically calls
601505a1493SJohn Baldwin  * acctwatch().
602505a1493SJohn Baldwin  */
603505a1493SJohn Baldwin static void
604505a1493SJohn Baldwin acct_thread(void *dummy)
605505a1493SJohn Baldwin {
606505a1493SJohn Baldwin 	u_char pri;
607505a1493SJohn Baldwin 
608505a1493SJohn Baldwin 	/* This is a low-priority kernel thread. */
609505a1493SJohn Baldwin 	pri = PRI_MAX_KERN;
610982d11f8SJeff Roberson 	thread_lock(curthread);
611505a1493SJohn Baldwin 	sched_prio(curthread, pri);
612982d11f8SJeff Roberson 	thread_unlock(curthread);
613505a1493SJohn Baldwin 
614505a1493SJohn Baldwin 	/* If another accounting kthread is already running, just die. */
615505a1493SJohn Baldwin 	sx_xlock(&acct_sx);
616505a1493SJohn Baldwin 	if (acct_state & ACCT_RUNNING) {
61771909edeSRobert Watson 		sx_xunlock(&acct_sx);
6183745c395SJulian Elischer 		kproc_exit(0);
619505a1493SJohn Baldwin 	}
620505a1493SJohn Baldwin 	acct_state |= ACCT_RUNNING;
621505a1493SJohn Baldwin 
622505a1493SJohn Baldwin 	/* Loop until we are asked to exit. */
623505a1493SJohn Baldwin 	while (!(acct_state & ACCT_EXITREQ)) {
624505a1493SJohn Baldwin 		/* Perform our periodic checks. */
625505a1493SJohn Baldwin 		acctwatch();
626505a1493SJohn Baldwin 
627505a1493SJohn Baldwin 		/*
628505a1493SJohn Baldwin 		 * We check this flag again before sleeping since the
629505a1493SJohn Baldwin 		 * acctwatch() might have shut down accounting and asked us
630505a1493SJohn Baldwin 		 * to exit.
631505a1493SJohn Baldwin 		 */
632505a1493SJohn Baldwin 		if (!(acct_state & ACCT_EXITREQ)) {
6336caa5f40SJohn Baldwin 			sx_sleep(&acct_state, &acct_sx, 0, "-",
6346caa5f40SJohn Baldwin 			    acctchkfreq * hz);
635505a1493SJohn Baldwin 		}
636505a1493SJohn Baldwin 	}
637505a1493SJohn Baldwin 
638505a1493SJohn Baldwin 	/*
639505a1493SJohn Baldwin 	 * Acknowledge the exit request and shutdown.  We clear both the
640505a1493SJohn Baldwin 	 * exit request and running flags.
641505a1493SJohn Baldwin 	 */
642505a1493SJohn Baldwin 	acct_state = 0;
643505a1493SJohn Baldwin 	sx_xunlock(&acct_sx);
6443745c395SJulian Elischer 	kproc_exit(0);
645df8bae1dSRodney W. Grimes }
646