kern_acct.c revision 69286
1193323Sed/*- 2193323Sed * Copyright (c) 1994 Christopher G. Demetriou 3193323Sed * Copyright (c) 1982, 1986, 1989, 1993 4193323Sed * The Regents of the University of California. All rights reserved. 5193323Sed * (c) UNIX System Laboratories, Inc. 6193323Sed * All or some portions of this file are derived from material licensed 7193323Sed * to the University of California by American Telephone and Telegraph 8193323Sed * Co. or Unix System Laboratories, Inc. and are reproduced herein with 9193323Sed * the permission of UNIX System Laboratories, Inc. 10193323Sed * 11193323Sed * Redistribution and use in source and binary forms, with or without 12193323Sed * modification, are permitted provided that the following conditions 13193323Sed * are met: 14193323Sed * 1. Redistributions of source code must retain the above copyright 15193323Sed * notice, this list of conditions and the following disclaimer. 16193323Sed * 2. Redistributions in binary form must reproduce the above copyright 17193323Sed * notice, this list of conditions and the following disclaimer in the 18193323Sed * documentation and/or other materials provided with the distribution. 19193323Sed * 3. All advertising materials mentioning features or use of this software 20193323Sed * must display the following acknowledgement: 21193323Sed * This product includes software developed by the University of 22193323Sed * California, Berkeley and its contributors. 23193323Sed * 4. Neither the name of the University nor the names of its contributors 24193323Sed * may be used to endorse or promote products derived from this software 25193323Sed * without specific prior written permission. 26193323Sed * 27198090Srdivacky * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 28193323Sed * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 29193323Sed * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 30193323Sed * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 31193323Sed * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 32198090Srdivacky * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 33193323Sed * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34193323Sed * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35193323Sed * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36193323Sed * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37193323Sed * SUCH DAMAGE. 38193323Sed * 39193323Sed * @(#)kern_acct.c 8.1 (Berkeley) 6/14/93 40193323Sed * $FreeBSD: head/sys/kern/kern_acct.c 69286 2000-11-27 22:52:31Z jake $ 41193323Sed */ 42193323Sed 43193323Sed#include <sys/param.h> 44193323Sed#include <sys/systm.h> 45193323Sed#include <sys/sysproto.h> 46193323Sed#include <sys/proc.h> 47193323Sed#include <sys/mount.h> 48193323Sed#include <sys/vnode.h> 49202878Srdivacky#include <sys/fcntl.h> 50202878Srdivacky#include <sys/syslog.h> 51202878Srdivacky#include <sys/kernel.h> 52202878Srdivacky#include <sys/sysent.h> 53202878Srdivacky#include <sys/sysctl.h> 54193323Sed#include <sys/namei.h> 55193323Sed#include <sys/acct.h> 56193323Sed#include <sys/resourcevar.h> 57193323Sed#include <sys/tty.h> 58193323Sed 59193323Sed 60198892Srdivacky/* 61193323Sed * The routines implemented in this file are described in: 62193323Sed * Leffler, et al.: The Design and Implementation of the 4.3BSD 63193323Sed * UNIX Operating System (Addison Welley, 1989) 64193323Sed * on pages 62-63. 65193323Sed * 66193323Sed * Arguably, to simplify accounting operations, this mechanism should 67193323Sed * be replaced by one in which an accounting log file (similar to /dev/klog) 68193323Sed * is read by a user process, etc. However, that has its own problems. 69193323Sed */ 70193323Sed 71193323Sed/* 72193323Sed * Internal accounting functions. 73193323Sed * The former's operation is described in Leffler, et al., and the latter 74193323Sed * was provided by UCB with the 4.4BSD-Lite release 75193323Sed */ 76193323Sedstatic comp_t encode_comp_t __P((u_long, u_long)); 77193323Sedstatic void acctwatch __P((void *)); 78193323Sed 79193323Sed/* 80193323Sed * Accounting callout used for periodic scheduling of acctwatch. 81193323Sed */ 82193323Sedstatic struct callout acctwatch_callout; 83193323Sed 84193323Sed/* 85193323Sed * Accounting vnode pointer, and saved vnode pointer. 86193323Sed */ 87193323Sedstatic struct vnode *acctp; 88193323Sedstatic struct vnode *savacctp; 89193323Sed 90193323Sed/* 91193323Sed * Values associated with enabling and disabling accounting 92193323Sed */ 93193323Sedstatic int acctsuspend = 2; /* stop accounting when < 2% free space left */ 94193323SedSYSCTL_INT(_kern, OID_AUTO, acct_suspend, CTLFLAG_RW, 95193323Sed &acctsuspend, 0, "percentage of free disk space below which accounting stops"); 96193323Sed 97193323Sedstatic int acctresume = 4; /* resume when free space risen to > 4% */ 98193323SedSYSCTL_INT(_kern, OID_AUTO, acct_resume, CTLFLAG_RW, 99193323Sed &acctresume, 0, "percentage of free disk space above which accounting resumes"); 100193323Sed 101193323Sedstatic int acctchkfreq = 15; /* frequency (in seconds) to check space */ 102193323SedSYSCTL_INT(_kern, OID_AUTO, acct_chkfreq, CTLFLAG_RW, 103193323Sed &acctchkfreq, 0, "frequency for checking the free space"); 104193323Sed 105193323Sed/* 106193323Sed * Accounting system call. Written based on the specification and 107193323Sed * previous implementation done by Mark Tinguely. 108193323Sed */ 109193323Sedint 110193323Sedacct(a1, uap) 111193323Sed struct proc *a1; 112193323Sed struct acct_args /* { 113193323Sed syscallarg(char *) path; 114193323Sed } */ *uap; 115193323Sed{ 116193323Sed struct proc *p = curproc; /* XXX */ 117193323Sed struct nameidata nd; 118193323Sed int error, flags; 119193323Sed 120193323Sed /* Make sure that the caller is root. */ 121193323Sed error = suser(p); 122193323Sed if (error) 123193323Sed return (error); 124193323Sed 125193323Sed /* 126193323Sed * If accounting is to be started to a file, open that file for 127193323Sed * writing and make sure it's a 'normal'. 128193323Sed */ 129193323Sed if (SCARG(uap, path) != NULL) { 130193323Sed NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_USERSPACE, SCARG(uap, path), 131193323Sed p); 132193323Sed flags = FWRITE; 133193323Sed error = vn_open(&nd, &flags, 0); 134193323Sed if (error) 135193323Sed return (error); 136193323Sed NDFREE(&nd, NDF_ONLY_PNBUF); 137193323Sed VOP_UNLOCK(nd.ni_vp, 0, p); 138193323Sed if (nd.ni_vp->v_type != VREG) { 139193323Sed vn_close(nd.ni_vp, FWRITE, p->p_ucred, p); 140193323Sed return (EACCES); 141193323Sed } 142193323Sed } 143193323Sed 144193323Sed /* 145193323Sed * If accounting was previously enabled, kill the old space-watcher, 146193323Sed * close the file, and (if no new file was specified, leave). 147193323Sed */ 148193323Sed if (acctp != NULLVP || savacctp != NULLVP) { 149193323Sed callout_stop(&acctwatch_callout); 150193323Sed error = vn_close((acctp != NULLVP ? acctp : savacctp), FWRITE, 151193323Sed p->p_ucred, p); 152193323Sed acctp = savacctp = NULLVP; 153193323Sed } 154193323Sed if (SCARG(uap, path) == NULL) 155193323Sed return (error); 156193323Sed 157193323Sed /* 158193323Sed * Save the new accounting file vnode, and schedule the new 159193323Sed * free space watcher. 160193323Sed */ 161193323Sed acctp = nd.ni_vp; 162193323Sed callout_init(&acctwatch_callout, 0); 163193323Sed acctwatch(NULL); 164193323Sed return (error); 165193323Sed} 166193323Sed 167193323Sed/* 168193323Sed * Write out process accounting information, on process exit. 169193323Sed * Data to be written out is specified in Leffler, et al. 170193323Sed * and are enumerated below. (They're also noted in the system 171193323Sed * "acct.h" header file.) 172202375Srdivacky */ 173193323Sed 174193323Sedint 175193323Sedacct_process(p) 176193323Sed struct proc *p; 177193323Sed{ 178193323Sed struct acct acct; 179198090Srdivacky struct rusage *r; 180193323Sed struct timeval ut, st, tmp; 181193323Sed int t; 182193323Sed struct vnode *vp; 183193323Sed 184193323Sed /* If accounting isn't enabled, don't bother */ 185193323Sed vp = acctp; 186193323Sed if (vp == NULLVP) 187193323Sed return (0); 188193323Sed 189193323Sed /* 190193323Sed * Get process accounting information. 191193323Sed */ 192193323Sed 193193323Sed /* (1) The name of the command that ran */ 194193323Sed bcopy(p->p_comm, acct.ac_comm, sizeof acct.ac_comm); 195193323Sed 196193323Sed /* (2) The amount of user and system time that was used */ 197193323Sed calcru(p, &ut, &st, NULL); 198193323Sed acct.ac_utime = encode_comp_t(ut.tv_sec, ut.tv_usec); 199193323Sed acct.ac_stime = encode_comp_t(st.tv_sec, st.tv_usec); 200193323Sed 201193323Sed /* (3) The elapsed time the commmand ran (and its starting time) */ 202193323Sed acct.ac_btime = p->p_stats->p_start.tv_sec; 203193323Sed microtime(&tmp); 204198090Srdivacky timevalsub(&tmp, &p->p_stats->p_start); 205193323Sed acct.ac_etime = encode_comp_t(tmp.tv_sec, tmp.tv_usec); 206198090Srdivacky 207202375Srdivacky /* (4) The average amount of memory used */ 208193323Sed r = &p->p_stats->p_ru; 209202375Srdivacky tmp = ut; 210198090Srdivacky timevaladd(&tmp, &st); 211193323Sed t = tmp.tv_sec * hz + tmp.tv_usec / tick; 212193323Sed if (t) 213198090Srdivacky acct.ac_mem = (r->ru_ixrss + r->ru_idrss + r->ru_isrss) / t; 214198090Srdivacky else 215193323Sed acct.ac_mem = 0; 216193323Sed 217193323Sed /* (5) The number of disk I/O operations done */ 218193323Sed acct.ac_io = encode_comp_t(r->ru_inblock + r->ru_oublock, 0); 219193323Sed 220193323Sed /* (6) The UID and GID of the process */ 221193323Sed acct.ac_uid = p->p_cred->p_ruid; 222193323Sed acct.ac_gid = p->p_cred->p_rgid; 223193323Sed 224193323Sed /* (7) The terminal from which the process was started */ 225193323Sed if ((p->p_flag & P_CONTROLT) && p->p_pgrp->pg_session->s_ttyp) 226193323Sed acct.ac_tty = dev2udev(p->p_pgrp->pg_session->s_ttyp->t_dev); 227193323Sed else 228193323Sed acct.ac_tty = NOUDEV; 229193323Sed 230193323Sed /* (8) The boolean flags that tell how the process terminated, etc. */ 231193323Sed acct.ac_flag = p->p_acflag; 232193323Sed 233193323Sed /* 234193323Sed * Eliminate any file size rlimit. 235193323Sed */ 236193323Sed if (p->p_limit->p_refcnt > 1 && 237193323Sed (p->p_limit->p_lflags & PL_SHAREMOD) == 0) { 238193323Sed p->p_limit->p_refcnt--; 239193323Sed p->p_limit = limcopy(p->p_limit); 240193323Sed } 241193323Sed p->p_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY; 242193323Sed 243193323Sed /* 244193323Sed * Write the accounting information to the file. 245193323Sed */ 246202375Srdivacky VOP_LEASE(vp, p, p->p_ucred, LEASE_WRITE); 247193323Sed return (vn_rdwr(UIO_WRITE, vp, (caddr_t)&acct, sizeof (acct), 248193323Sed (off_t)0, UIO_SYSSPACE, IO_APPEND|IO_UNIT, p->p_ucred, 249193323Sed (int *)0, p)); 250193323Sed} 251193323Sed 252193323Sed/* 253193323Sed * Encode_comp_t converts from ticks in seconds and microseconds 254193323Sed * to ticks in 1/AHZ seconds. The encoding is described in 255193323Sed * Leffler, et al., on page 63. 256193323Sed */ 257193323Sed 258193323Sed#define MANTSIZE 13 /* 13 bit mantissa. */ 259193323Sed#define EXPSIZE 3 /* Base 8 (3 bit) exponent. */ 260193323Sed#define MAXFRACT ((1 << MANTSIZE) - 1) /* Maximum fractional value. */ 261193323Sed 262193323Sedstatic comp_t 263193323Sedencode_comp_t(s, us) 264193323Sed u_long s, us; 265193323Sed{ 266193323Sed int exp, rnd; 267193323Sed 268193323Sed exp = 0; 269193323Sed rnd = 0; 270193323Sed s *= AHZ; 271193323Sed s += us / (1000000 / AHZ); /* Maximize precision. */ 272193323Sed 273193323Sed while (s > MAXFRACT) { 274193323Sed rnd = s & (1 << (EXPSIZE - 1)); /* Round up? */ 275193323Sed s >>= EXPSIZE; /* Base 8 exponent == 3 bit shift. */ 276193323Sed exp++; 277193323Sed } 278193323Sed 279193323Sed /* If we need to round up, do it (and handle overflow correctly). */ 280193323Sed if (rnd && (++s > MAXFRACT)) { 281193323Sed s >>= EXPSIZE; 282193323Sed exp++; 283193323Sed } 284193323Sed 285198090Srdivacky /* Clean it up and polish it off. */ 286193323Sed exp <<= MANTSIZE; /* Shift the exponent into place */ 287193323Sed exp += s; /* and add on the mantissa. */ 288193323Sed return (exp); 289193323Sed} 290193323Sed 291193323Sed/* 292202375Srdivacky * Periodically check the file system to see if accounting 293193323Sed * should be turned on or off. Beware the case where the vnode 294193323Sed * has been vgone()'d out from underneath us, e.g. when the file 295193323Sed * system containing the accounting file has been forcibly unmounted. 296193323Sed */ 297193323Sed/* ARGSUSED */ 298193323Sedstatic void 299193323Sedacctwatch(a) 300193323Sed void *a; 301193323Sed{ 302193323Sed struct statfs sb; 303193323Sed 304193323Sed if (savacctp != NULLVP) { 305193323Sed if (savacctp->v_type == VBAD) { 306193323Sed (void) vn_close(savacctp, FWRITE, NOCRED, NULL); 307193323Sed savacctp = NULLVP; 308193323Sed return; 309193323Sed } 310193323Sed (void)VFS_STATFS(savacctp->v_mount, &sb, (struct proc *)0); 311193323Sed if (sb.f_bavail > acctresume * sb.f_blocks / 100) { 312193323Sed acctp = savacctp; 313193323Sed savacctp = NULLVP; 314193323Sed log(LOG_NOTICE, "Accounting resumed\n"); 315193323Sed } 316193323Sed } else { 317193323Sed if (acctp == NULLVP) 318193323Sed return; 319193323Sed if (acctp->v_type == VBAD) { 320193323Sed (void) vn_close(acctp, FWRITE, NOCRED, NULL); 321193323Sed acctp = NULLVP; 322193323Sed return; 323193323Sed } 324193323Sed (void)VFS_STATFS(acctp->v_mount, &sb, (struct proc *)0); 325193323Sed if (sb.f_bavail <= acctsuspend * sb.f_blocks / 100) { 326193323Sed savacctp = acctp; 327193323Sed acctp = NULLVP; 328193323Sed log(LOG_NOTICE, "Accounting suspended\n"); 329193323Sed } 330193323Sed } 331193323Sed callout_reset(&acctwatch_callout, acctchkfreq * hz, acctwatch, NULL); 332193323Sed} 333193323Sed