sys/kern/kern_acct.c

/*
 * Copyright (c) 1982, 1986, 1989 Regents of the University of California.
 * All rights reserved.
 *
 * 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.
 *
 *      from: @(#)kern_acct.c   7.18 (Berkeley) 5/11/91
 *      $Id: kern_acct.c,v 1.4 1993/10/19 01:07:21 nate Exp $
 */

#include "param.h"
#include "systm.h"
#include "namei.h"
#include "resourcevar.h"
#include "proc.h"
#include "ioctl.h"
#include "termios.h"
#include "tty.h"
#include "vnode.h"
#include "mount.h"
#include "kernel.h"
#include "file.h"
#include "acct.h"
#include "syslog.h"

#include "vm/vm.h"
#include "vm/vm_param.h"

/*
 * 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% */
struct  timeval chk = { 15, 0 };/* frequency to check space for accounting */
struct  vnode *acctp = NULL;    /* file to which to do accounting */
struct  vnode *savacctp = NULL; /* file to which to do accounting when space */

/*
 * Enable or disable process accounting.
 *
 * If a non-null filename is given, that file is used to store accounting
 * records on process exit. If a null filename is given process accounting
 * is suspended. If accounting is enabled, the system checks the amount
 * of freespace on the filesystem at timeval intervals. If the amount of
 * freespace is below acctsuspend percent, accounting is suspended. If
 * accounting has been suspended, and freespace rises above acctresume,
 * accounting is resumed.
 */

/* Mark Tinguely (tinguely@plains.NoDak.edu) 8/10/93 */

struct sysacct_args {
        char    *fname;
};

/* ARGSUSED */
sysacct(p, uap, retval)
        struct proc *p;
        struct sysacct_args *uap;
        int *retval;
{

        register struct nameidata *ndp;
        struct nameidata nd;
        struct vattr attr;
        int rv, acctwatch();

        if (p->p_ucred->cr_uid != 0)
                return(EPERM);          /* must be root */

        /*
         * Step 1. turn off accounting (if on). exit if fname is nil
         */

        rv = 0;                         /* just in case nothing is open */
        if (acctp != NULL) {
                rv = vn_close(acctp, FWRITE, p->p_ucred, p);
                untimeout(acctwatch, (caddr_t) &chk);   /* turn off disk check */
                acctp = NULL;
        }
        else if (savacctp != NULL ) {
                rv = vn_close(savacctp, FWRITE, p->p_ucred, p);
                untimeout(acctwatch, (caddr_t) &chk);   /* turn off disk check */
                savacctp = NULL;
        }

        if (uap->fname == NULL)         /* accounting stopping complete */
                return(rv);

        /*
         * Step 2. open accounting filename for writing.
         */

        nd.ni_segflg = UIO_USERSPACE;
        nd.ni_dirp = uap->fname;

        /* is it there? */
        if (rv = vn_open(&nd, p, FWRITE, 0))
                return (rv);

        /* Step 2. Check the attributes on accounting file */
        rv = VOP_GETATTR(nd.ni_vp, &attr, p->p_ucred, p);
        if (rv)
                goto acct_fail;

        /* is filesystem writable, do I have permission to write and is
         * a regular file?
         */
        if (nd.ni_vp->v_mount->mnt_flag & MNT_RDONLY) {
                rv = EROFS;     /* to be consistant with man page */
                goto acct_fail;
        }

        if ((VOP_ACCESS(nd.ni_vp, VWRITE, p->p_ucred, p)) ||
            (attr.va_type != VREG)) {
                rv = EACCES;    /* permission denied error */
                goto acct_fail;
        }

        /* Step 3. Save the accounting file vnode, schedule freespace watch. */

        acctp  = nd.ni_vp;
        savacctp = NULL;
        acctwatch(&chk);                /* look for full system */
        VOP_UNLOCK(acctp);
        return(0);              /* end successfully */

acct_fail:

        vn_close(nd.ni_vp, FWRITE, p->p_ucred, p);
        return(rv);
}

/*
 * Periodically check the file system to see if accounting
 * should be turned on or off.
 */
acctwatch(resettime)
        struct timeval *resettime;
{
        struct statfs sb;

        if (savacctp) {
                (void)VFS_STATFS(savacctp->v_mount, &sb, (struct proc *)0);
                if (sb.f_bavail > acctresume * sb.f_blocks / 100) {
                        acctp = savacctp;
                        savacctp = NULL;
                        log(LOG_NOTICE, "Accounting resumed\n");
                        return;
                }
        }
        if (acctp == NULL)
                return;
        (void)VFS_STATFS(acctp->v_mount, &sb, (struct proc *)0);
        if (sb.f_bavail <= acctsuspend * sb.f_blocks / 100) {
                savacctp = acctp;
                acctp = NULL;
                log(LOG_NOTICE, "Accounting suspended\n");
        }
        timeout(acctwatch, (caddr_t)resettime, hzto(resettime));
}

/*
 * This routine calculates an accounting record for a process and,
 * if accounting is enabled, writes it to the accounting file.
 */

/* Mark Tinguely (tinguely@plains.NoDak.edu) 8/10/93 */

acct(p)
        register struct proc *p;
{

        struct acct acct;
        struct rusage *r;
        int rv;
        long i;
        u_int cnt;
        char *c;
        comp_t int2comp();


        if (acctp == NULL)      /* accounting not turned on */
                return;

        /* Step 1. Get command name (remove path if necessary) */

        strncpy(acct.ac_comm, p->p_comm, sizeof(acct.ac_comm));

        /* Step 2. Get rest of information */

        acct.ac_utime = int2comp((unsigned) p->p_utime.tv_sec * 1000000 + p->p_utime.tv_usec);
        acct.ac_stime = int2comp((unsigned) p->p_stime.tv_sec * 1000000 + p->p_stime.tv_usec);
        acct.ac_btime = p->p_stats->p_start.tv_sec;
                        /* elapse time = current - start */
        i = (time.tv_sec - p->p_stats->p_start.tv_sec) * 1000000 +
            (time.tv_usec - p->p_stats->p_start.tv_usec);
        acct.ac_etime = int2comp((unsigned) i);

        acct.ac_uid = p->p_cred->p_ruid;
        acct.ac_gid = p->p_cred->p_rgid;

        r = &p->p_stats->p_ru;
        if (i = (p->p_utime.tv_sec + p->p_stime.tv_sec) * hz +
                (p->p_utime.tv_usec + p->p_stime.tv_usec) / tick)
                acct.ac_mem = (r->ru_ixrss + r->ru_idrss + r->ru_isrss) / i;
        else
                acct.ac_mem = 0;
        acct.ac_io = int2comp((unsigned) (r->ru_inblock + r->ru_oublock) * 1000000);

        if ((p->p_flag & SCTTY) && p->p_pgrp->pg_session->s_ttyp)
                acct.ac_tty = p->p_pgrp->pg_session->s_ttyp->t_dev;
        else
                acct.ac_tty = NODEV;
        acct.ac_flag = p->p_acflag;

        /* Step 3. Write record to file */


        rv = vn_rdwr(UIO_WRITE, acctp, (caddr_t) &acct, sizeof (acct),
            (off_t)0, UIO_SYSSPACE, IO_APPEND|IO_UNIT, p->p_ucred, (int *) NULL,
            p);
}

/*  int2comp converts from ticks in a microsecond to ticks in 1/AHZ second
 *
 * comp_t is a psuedo-floating point number with 13 bits of
 * mantissa and 3 bits of base 8 exponent and has resolution
 * of 1/AHZ seconds.
 *
 * notice I already converted the incoming values into microseconds
 * I need to convert back into AHZ ticks.
 */

/* Mark Tinguely (tinguely@plains.NoDak.edu) 8/10/93 */


#define RES 13
#define EXP 3
#define MAXFRACT 1<<RES

comp_t
int2comp(mantissa)
unsigned int mantissa;
{
        comp_t exp=0;

        mantissa = mantissa * AHZ / 1000000;    /* convert back to AHZ ticks */
        while (mantissa > MAXFRACT) {
                mantissa >>= EXP;       /* base 8 exponent */
                exp++;
        }
        exp <<= RES;            /* move the exponent */
        exp += mantissa;        /* add on the manissa */
        return (exp);
}