1 /* $OpenBSD: kern_acct.c,v 1.9 2000/05/05 08:38:23 art Exp $ */ 2 /* $NetBSD: kern_acct.c,v 1.42 1996/02/04 02:15:12 christos Exp $ */ 3 4 /*- 5 * Copyright (c) 1994 Christopher G. Demetriou 6 * Copyright (c) 1982, 1986, 1989, 1993 7 * The Regents of the University of California. All rights reserved. 8 * (c) UNIX System Laboratories, Inc. 9 * All or some portions of this file are derived from material licensed 10 * to the University of California by American Telephone and Telegraph 11 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 12 * the permission of UNIX System Laboratories, Inc. 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions 16 * are met: 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 2. Redistributions in binary form must reproduce the above copyright 20 * notice, this list of conditions and the following disclaimer in the 21 * documentation and/or other materials provided with the distribution. 22 * 3. All advertising materials mentioning features or use of this software 23 * must display the following acknowledgement: 24 * This product includes software developed by the University of 25 * California, Berkeley and its contributors. 26 * 4. Neither the name of the University nor the names of its contributors 27 * may be used to endorse or promote products derived from this software 28 * without specific prior written permission. 29 * 30 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 31 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 32 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 33 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 34 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 35 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 36 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 37 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 38 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 39 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 40 * SUCH DAMAGE. 41 * 42 * @(#)kern_acct.c 8.1 (Berkeley) 6/14/93 43 */ 44 45 #include <sys/param.h> 46 #include <sys/systm.h> 47 #include <sys/proc.h> 48 #include <sys/mount.h> 49 #include <sys/vnode.h> 50 #include <sys/file.h> 51 #include <sys/syslog.h> 52 #include <sys/kernel.h> 53 #include <sys/namei.h> 54 #include <sys/errno.h> 55 #include <sys/acct.h> 56 #include <sys/resourcevar.h> 57 #include <sys/ioctl.h> 58 #include <sys/tty.h> 59 #include <sys/timeout.h> 60 61 #include <sys/syscallargs.h> 62 63 /* 64 * The routines implemented in this file are described in: 65 * Leffler, et al.: The Design and Implementation of the 4.3BSD 66 * UNIX Operating System (Addison Welley, 1989) 67 * on pages 62-63. 68 * 69 * Arguably, to simplify accounting operations, this mechanism should 70 * be replaced by one in which an accounting log file (similar to /dev/klog) 71 * is read by a user process, etc. However, that has its own problems. 72 */ 73 74 /* 75 * Internal accounting functions. 76 * The former's operation is described in Leffler, et al., and the latter 77 * was provided by UCB with the 4.4BSD-Lite release 78 */ 79 comp_t encode_comp_t __P((u_long, u_long)); 80 void acctwatch __P((void *)); 81 82 /* 83 * Accounting vnode pointer, and saved vnode pointer. 84 */ 85 struct vnode *acctp; 86 struct vnode *savacctp; 87 88 /* 89 * Values associated with enabling and disabling accounting 90 */ 91 int acctsuspend = 2; /* stop accounting when < 2% free space left */ 92 int acctresume = 4; /* resume when free space risen to > 4% */ 93 int acctchkfreq = 15; /* frequency (in seconds) to check space */ 94 95 /* 96 * Accounting system call. Written based on the specification and 97 * previous implementation done by Mark Tinguely. 98 */ 99 int 100 sys_acct(p, v, retval) 101 struct proc *p; 102 void *v; 103 register_t *retval; 104 { 105 struct sys_acct_args /* { 106 syscallarg(char *) path; 107 } */ *uap = v; 108 struct nameidata nd; 109 int error; 110 static struct timeout acct_timeout; 111 112 /* Make sure that the caller is root. */ 113 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 114 return (error); 115 116 /* 117 * If accounting is to be started to a file, open that file for 118 * writing and make sure it's a 'normal'. 119 */ 120 if (SCARG(uap, path) != NULL) { 121 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_USERSPACE, SCARG(uap, path), 122 p); 123 if ((error = vn_open(&nd, FWRITE|O_APPEND, 0)) != 0) 124 return (error); 125 VOP_UNLOCK(nd.ni_vp, 0, p); 126 if (nd.ni_vp->v_type != VREG) { 127 vn_close(nd.ni_vp, FWRITE, p->p_ucred, p); 128 return (EACCES); 129 } 130 } 131 132 /* 133 * If accounting was previously enabled, kill the old space-watcher, 134 * close the file, and (if no new file was specified, leave). 135 */ 136 if (acctp != NULLVP || savacctp != NULLVP) { 137 timeout_del(&acct_timeout); 138 error = vn_close((acctp != NULLVP ? acctp : savacctp), FWRITE, 139 p->p_ucred, p); 140 acctp = savacctp = NULLVP; 141 } 142 if (SCARG(uap, path) == NULL) 143 return (error); 144 145 /* 146 * Save the new accounting file vnode, and schedule the new 147 * free space watcher. 148 */ 149 acctp = nd.ni_vp; 150 if (!timeout_initialized(&acct_timeout)) 151 timeout_set(&acct_timeout, acctwatch, &acct_timeout); 152 acctwatch(&acct_timeout); 153 return (error); 154 } 155 156 /* 157 * Write out process accounting information, on process exit. 158 * Data to be written out is specified in Leffler, et al. 159 * and are enumerated below. (They're also noted in the system 160 * "acct.h" header file.) 161 */ 162 int 163 acct_process(p) 164 struct proc *p; 165 { 166 struct acct acct; 167 struct rusage *r; 168 struct timeval ut, st, tmp; 169 int s, t; 170 struct vnode *vp; 171 struct plimit *oplim = NULL; 172 int error; 173 174 /* If accounting isn't enabled, don't bother */ 175 vp = acctp; 176 if (vp == NULLVP) 177 return (0); 178 179 /* 180 * Raise the file limit so that accounting can't be stopped by the 181 * user. (XXX - we should think about the cpu limit too). 182 */ 183 if (p->p_limit->p_refcnt > 1) { 184 oplim = p->p_limit; 185 p->p_limit = limcopy(p->p_limit); 186 } 187 p->p_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY; 188 189 /* 190 * Get process accounting information. 191 */ 192 193 /* (1) The name of the command that ran */ 194 bcopy(p->p_comm, acct.ac_comm, sizeof acct.ac_comm); 195 196 /* (2) The amount of user and system time that was used */ 197 calcru(p, &ut, &st, NULL); 198 acct.ac_utime = encode_comp_t(ut.tv_sec, ut.tv_usec); 199 acct.ac_stime = encode_comp_t(st.tv_sec, st.tv_usec); 200 201 /* (3) The elapsed time the commmand ran (and its starting time) */ 202 acct.ac_btime = p->p_stats->p_start.tv_sec; 203 s = splclock(); 204 timersub(&time, &p->p_stats->p_start, &tmp); 205 splx(s); 206 acct.ac_etime = encode_comp_t(tmp.tv_sec, tmp.tv_usec); 207 208 /* (4) The average amount of memory used */ 209 r = &p->p_stats->p_ru; 210 timeradd(&ut, &st, &tmp); 211 t = tmp.tv_sec * hz + tmp.tv_usec / tick; 212 if (t) 213 acct.ac_mem = (r->ru_ixrss + r->ru_idrss + r->ru_isrss) / t; 214 else 215 acct.ac_mem = 0; 216 217 /* (5) The number of disk I/O operations done */ 218 acct.ac_io = encode_comp_t(r->ru_inblock + r->ru_oublock, 0); 219 220 /* (6) The UID and GID of the process */ 221 acct.ac_uid = p->p_cred->p_ruid; 222 acct.ac_gid = p->p_cred->p_rgid; 223 224 /* (7) The terminal from which the process was started */ 225 if ((p->p_flag & P_CONTROLT) && p->p_pgrp->pg_session->s_ttyp) 226 acct.ac_tty = p->p_pgrp->pg_session->s_ttyp->t_dev; 227 else 228 acct.ac_tty = NODEV; 229 230 /* (8) The boolean flags that tell how the process terminated, etc. */ 231 acct.ac_flag = p->p_acflag; 232 233 /* 234 * Now, just write the accounting information to the file. 235 */ 236 VOP_LEASE(vp, p, p->p_ucred, LEASE_WRITE); 237 error = vn_rdwr(UIO_WRITE, vp, (caddr_t)&acct, sizeof (acct), 238 (off_t)0, UIO_SYSSPACE, IO_APPEND|IO_UNIT, p->p_ucred, NULL, p); 239 240 if (oplim) { 241 limfree(p->p_limit); 242 p->p_limit = oplim; 243 } 244 245 return error; 246 } 247 248 /* 249 * Encode_comp_t converts from ticks in seconds and microseconds 250 * to ticks in 1/AHZ seconds. The encoding is described in 251 * Leffler, et al., on page 63. 252 */ 253 254 #define MANTSIZE 13 /* 13 bit mantissa. */ 255 #define EXPSIZE 3 /* Base 8 (3 bit) exponent. */ 256 #define MAXFRACT ((1 << MANTSIZE) - 1) /* Maximum fractional value. */ 257 258 comp_t 259 encode_comp_t(s, us) 260 u_long s, us; 261 { 262 int exp, rnd; 263 264 exp = 0; 265 rnd = 0; 266 s *= AHZ; 267 s += us / (1000000 / AHZ); /* Maximize precision. */ 268 269 while (s > MAXFRACT) { 270 rnd = s & (1 << (EXPSIZE - 1)); /* Round up? */ 271 s >>= EXPSIZE; /* Base 8 exponent == 3 bit shift. */ 272 exp++; 273 } 274 275 /* If we need to round up, do it (and handle overflow correctly). */ 276 if (rnd && (++s > MAXFRACT)) { 277 s >>= EXPSIZE; 278 exp++; 279 } 280 281 /* Clean it up and polish it off. */ 282 exp <<= MANTSIZE; /* Shift the exponent into place */ 283 exp += s; /* and add on the mantissa. */ 284 return (exp); 285 } 286 287 /* 288 * Periodically check the file system to see if accounting 289 * should be turned on or off. Beware the case where the vnode 290 * has been vgone()'d out from underneath us, e.g. when the file 291 * system containing the accounting file has been forcibly unmounted. 292 */ 293 /* ARGSUSED */ 294 void 295 acctwatch(arg) 296 void *arg; 297 { 298 struct timeout *to = (struct timeout *)arg; 299 struct statfs sb; 300 301 if (savacctp != NULLVP) { 302 if (savacctp->v_type == VBAD) { 303 (void) vn_close(savacctp, FWRITE, NOCRED, NULL); 304 savacctp = NULLVP; 305 return; 306 } 307 (void)VFS_STATFS(savacctp->v_mount, &sb, (struct proc *)0); 308 if (sb.f_bavail > acctresume * sb.f_blocks / 100) { 309 acctp = savacctp; 310 savacctp = NULLVP; 311 log(LOG_NOTICE, "Accounting resumed\n"); 312 } 313 } else if (acctp != NULLVP) { 314 if (acctp->v_type == VBAD) { 315 (void) vn_close(acctp, FWRITE, NOCRED, NULL); 316 acctp = NULLVP; 317 return; 318 } 319 (void)VFS_STATFS(acctp->v_mount, &sb, (struct proc *)0); 320 if (sb.f_bavail <= acctsuspend * sb.f_blocks / 100) { 321 savacctp = acctp; 322 acctp = NULLVP; 323 log(LOG_NOTICE, "Accounting suspended\n"); 324 } 325 } else 326 return; 327 timeout_add(to, acctchkfreq * hz); 328 } 329