gems-kernel/source/THIRDPARTY/xnu/bsd/kern/kern_acct.c
2024-06-03 11:29:39 -05:00

420 lines
13 KiB
C

/*
* Copyright (c) 2000-2010 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. The rights granted to you under the License
* may not be used to create, or enable the creation or redistribution of,
* unlawful or unlicensed copies of an Apple operating system, or to
* circumvent, violate, or enable the circumvention or violation of, any
* terms of an Apple operating system software license agreement.
*
* Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
/* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
/*-
* Copyright (c) 1982, 1986, 1989, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)kern_acct.c 8.1 (Berkeley) 6/14/93
*/
/* HISTORY
* 08-May-95 Mac Gillon (mgillon) at NeXT
* Purged old history
* New version based on 4.4
*/
/*
* NOTICE: This file was modified by SPARTA, Inc. in 2005 to introduce
* support for mandatory and extensible security protections. This notice
* is included in support of clause 2.2 (b) of the Apple Public License,
* Version 2.0.
*/
#include <sys/param.h>
#include <sys/proc_internal.h>
#include <sys/kauth.h>
#include <sys/mount_internal.h>
#include <sys/vnode_internal.h>
#include <sys/file_internal.h>
#include <sys/syslog.h>
#include <sys/kernel.h>
#include <sys/namei.h>
#include <sys/errno.h>
#include <sys/acct.h>
#include <sys/resourcevar.h>
#include <sys/ioctl.h>
#include <sys/tty.h>
#include <sys/sysproto.h>
#if CONFIG_MACF
#include <security/mac_framework.h>
#endif
/*
* The routines implemented in this file are described in:
* Leffler, et al.: The Design and Implementation of the 4.3BSD
* UNIX Operating System (Addison Welley, 1989)
* on pages 62-63.
*
* Arguably, to simplify accounting operations, this mechanism should
* be replaced by one in which an accounting log file (similar to /dev/klog)
* is read by a user process, etc. However, that has its own problems.
*/
/*
* Internal accounting functions.
* The former's operation is described in Leffler, et al., and the latter
* was provided by UCB with the 4.4BSD-Lite release
*/
comp_t encode_comp_t(uint32_t, uint32_t);
void acctwatch(void *);
/*
* Accounting vnode pointer, and suspended accounting vnode pointer. States
* are as follows:
*
* acctp suspend_acctp state
* ------------- ------------ ------------------------------
* NULL NULL Accounting disabled
* !NULL NULL Accounting enabled
* NULL !NULL Accounting enabled, but suspended
* !NULL !NULL <not allowed>
*/
struct vnode *acctp;
struct vnode *suspend_acctp;
/*
* Values associated with enabling and disabling accounting
*/
int acctsuspend = 2; /* stop accounting when < 2% free space left */
int acctresume = 4; /* resume when free space risen to > 4% */
int acctchkfreq = 15; /* frequency (in seconds) to check space */
static LCK_GRP_DECLARE(acct_subsys_lck_grp, "acct");
static LCK_MTX_DECLARE(acct_subsys_mutex, &acct_subsys_lck_grp);
#define ACCT_SUBSYS_LOCK() lck_mtx_lock(&acct_subsys_mutex)
#define ACCT_SUBSYS_UNLOCK() lck_mtx_unlock(&acct_subsys_mutex)
/*
* Accounting system call. Written based on the specification and
* previous implementation done by Mark Tinguely.
*/
int
acct(proc_t p, struct acct_args *uap, __unused int *retval)
{
struct nameidata nd;
int error;
struct vfs_context *ctx;
ctx = vfs_context_current();
/* Make sure that the caller is root. */
if ((error = suser(vfs_context_ucred(ctx), &p->p_acflag))) {
return error;
}
/*
* If accounting is to be started to a file, open that file for
* writing and make sure it's a 'normal'.
*/
if (uap->path != USER_ADDR_NULL) {
NDINIT(&nd, LOOKUP, OP_OPEN, NOFOLLOW, UIO_USERSPACE, uap->path, ctx);
if ((error = vn_open(&nd, FWRITE, 0))) {
return error;
}
#if CONFIG_MACF
error = mac_system_check_acct(vfs_context_ucred(ctx), nd.ni_vp);
if (error) {
vnode_put(nd.ni_vp);
vn_close(nd.ni_vp, FWRITE, ctx);
return error;
}
#endif
vnode_put(nd.ni_vp);
if (nd.ni_vp->v_type != VREG) {
vn_close(nd.ni_vp, FWRITE, ctx);
return EACCES;
}
}
#if CONFIG_MACF
else {
error = mac_system_check_acct(vfs_context_ucred(ctx), NULL);
if (error) {
return error;
}
}
#endif
/*
* If accounting was previously enabled, kill the old space-watcher,
* close the file, and (if no new file was specified, leave).
*/
ACCT_SUBSYS_LOCK();
if (acctp != NULLVP || suspend_acctp != NULLVP) {
untimeout(acctwatch, NULL);
error = vn_close((acctp != NULLVP ? acctp : suspend_acctp),
FWRITE, vfs_context_current());
acctp = suspend_acctp = NULLVP;
}
if (uap->path == USER_ADDR_NULL) {
ACCT_SUBSYS_UNLOCK();
return error;
}
/*
* Save the new accounting file vnode, and schedule the new
* free space watcher.
*/
acctp = nd.ni_vp;
ACCT_SUBSYS_UNLOCK();
acctwatch(NULL);
return error;
}
/*
* Write out process accounting information, on process exit.
* Data to be written out is specified in Leffler, et al.
* and are enumerated below. (They're also noted in the system
* "acct.h" header file.)
*/
int
acct_process(proc_t p)
{
struct acct an_acct;
struct rusage rup, *r;
struct timeval ut, st, tmp;
int t;
int error;
struct vnode *vp;
kauth_cred_t safecred;
struct pgrp *pg;
/* If accounting isn't enabled, don't bother */
ACCT_SUBSYS_LOCK();
vp = acctp;
if (vp == NULLVP) {
ACCT_SUBSYS_UNLOCK();
return 0;
}
/*
* Get process accounting information.
*/
/* (1) The name of the command that ran */
bcopy(p->p_comm, an_acct.ac_comm, sizeof an_acct.ac_comm);
/* (2) The amount of user and system time that was used */
calcru(p, &ut, &st, NULL);
an_acct.ac_utime = encode_comp_t((uint32_t)ut.tv_sec, ut.tv_usec);
an_acct.ac_stime = encode_comp_t((uint32_t)st.tv_sec, st.tv_usec);
/* (3) The elapsed time the commmand ran (and its starting time) */
an_acct.ac_btime = (u_int32_t)p->p_start.tv_sec;
microtime(&tmp);
timevalsub(&tmp, &p->p_start);
an_acct.ac_etime = encode_comp_t((uint32_t)tmp.tv_sec, tmp.tv_usec);
/* (4) The average amount of memory used */
proc_lock(p);
rup = p->p_stats->p_ru;
proc_unlock(p);
r = &rup;
tmp = ut;
timevaladd(&tmp, &st);
t = (int)(tmp.tv_sec * hz + tmp.tv_usec / tick);
if (t) {
an_acct.ac_mem = (u_int16_t)((r->ru_ixrss + r->ru_idrss + r->ru_isrss) / t);
} else {
an_acct.ac_mem = 0;
}
/* (5) The number of disk I/O operations done */
an_acct.ac_io = encode_comp_t((uint32_t)(r->ru_inblock + r->ru_oublock), 0);
/* (6) The UID and GID of the process */
safecred = kauth_cred_proc_ref(p);
an_acct.ac_uid = kauth_cred_getruid(safecred);
an_acct.ac_gid = kauth_cred_getrgid(safecred);
/* (7) The terminal from which the process was started */
an_acct.ac_tty = NODEV;
if ((p->p_flag & P_CONTROLT) && (pg = proc_pgrp(p, NULL))) {
an_acct.ac_tty = os_atomic_load(&pg->pg_session->s_ttydev, relaxed);
pgrp_rele(pg);
}
/* (8) The boolean flags that tell how the process terminated, etc. */
an_acct.ac_flag = (u_int8_t)p->p_acflag;
/*
* Now, just write the accounting information to the file.
*/
if ((error = vnode_getwithref(vp)) == 0) {
error = vn_rdwr(UIO_WRITE, vp, (caddr_t)&an_acct, sizeof(an_acct),
(off_t)0, UIO_SYSSPACE, IO_APPEND | IO_UNIT, safecred,
(int *)0, p);
vnode_put(vp);
}
kauth_cred_unref(&safecred);
ACCT_SUBSYS_UNLOCK();
return error;
}
/*
* Encode_comp_t converts from ticks in seconds and microseconds
* to ticks in 1/AHZ seconds. The encoding is described in
* Leffler, et al., on page 63.
*/
#define MANTSIZE 13 /* 13 bit mantissa. */
#define EXPSIZE 3 /* Base 8 (3 bit) exponent. */
#define MAXFRACT ((1 << MANTSIZE) - 1) /* Maximum fractional value. */
comp_t
encode_comp_t(uint32_t s, uint32_t us)
{
int exp, rnd;
exp = 0;
rnd = 0;
s *= AHZ;
s += us / (1000000 / AHZ); /* Maximize precision. */
while (s > MAXFRACT) {
rnd = s & (1 << (EXPSIZE - 1)); /* Round up? */
s >>= EXPSIZE; /* Base 8 exponent == 3 bit shift. */
exp++;
}
/* If we need to round up, do it (and handle overflow correctly). */
if (rnd && (++s > MAXFRACT)) {
s >>= EXPSIZE;
exp++;
}
/* Clean it up and polish it off. */
exp <<= MANTSIZE; /* Shift the exponent into place */
exp += s; /* and add on the mantissa. */
return (comp_t)exp;
}
/*
* Periodically check the file system to see if accounting
* should be turned on or off. Beware the case where the vnode
* has been vgone()'d out from underneath us, e.g. when the file
* system containing the accounting file has been forcibly unmounted.
*/
/* ARGSUSED */
void
acctwatch(__unused void *a)
{
vfs_context_t ctx = vfs_context_current();
struct vfs_attr va;
VFSATTR_INIT(&va);
VFSATTR_WANTED(&va, f_blocks);
VFSATTR_WANTED(&va, f_bavail);
ACCT_SUBSYS_LOCK();
if (suspend_acctp != NULLVP) {
/*
* Resuming accounting when accounting is suspended, and the
* filesystem containing the suspended accounting file goes
* below a low watermark
*/
if (suspend_acctp->v_type == VBAD) {
(void) vn_close(suspend_acctp, FWRITE, vfs_context_kernel());
suspend_acctp = NULLVP;
ACCT_SUBSYS_UNLOCK();
return;
}
(void)vfs_getattr(suspend_acctp->v_mount, &va, ctx);
if (va.f_bavail > acctresume * va.f_blocks / 100) {
acctp = suspend_acctp;
suspend_acctp = NULLVP;
log(LOG_NOTICE, "Accounting resumed\n");
}
} else if (acctp != NULLVP) {
/*
* Suspending accounting when accounting is currently active,
* and the filesystem containing the active accounting file
* goes over a high watermark
*/
if (acctp->v_type == VBAD) {
(void) vn_close(acctp, FWRITE, vfs_context_kernel());
acctp = NULLVP;
ACCT_SUBSYS_UNLOCK();
return;
}
(void)vfs_getattr(acctp->v_mount, &va, ctx);
if (va.f_bavail <= acctsuspend * va.f_blocks / 100) {
suspend_acctp = acctp;
acctp = NULLVP;
log(LOG_NOTICE, "Accounting suspended\n");
}
} else {
ACCT_SUBSYS_UNLOCK();
return;
}
ACCT_SUBSYS_UNLOCK();
timeout(acctwatch, NULL, acctchkfreq * hz);
}