1 /*- 2 * Copyright (c) 1994 Christopher G. Demetriou 3 * Copyright (c) 1982, 1986, 1989, 1993 4 * The Regents of the University of California. All rights reserved. 5 * (c) UNIX System Laboratories, Inc. 6 * All or some portions of this file are derived from material licensed 7 * to the University of California by American Telephone and Telegraph 8 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 9 * the permission of UNIX System Laboratories, Inc. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the University of 22 * California, Berkeley and its contributors. 23 * 4. Neither the name of the University nor the names of its contributors 24 * may be used to endorse or promote products derived from this software 25 * without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37 * SUCH DAMAGE. 38 * 39 * from: @(#)kern_acct.c 8.1 (Berkeley) 6/14/93 40 * $Id: kern_acct.c,v 1.27 1994/05/24 06:49:14 cgd Exp $ 41 */ 42 43 #include <sys/param.h> 44 #include <sys/proc.h> 45 #include <sys/mount.h> 46 #include <sys/vnode.h> 47 #include <sys/file.h> 48 #include <sys/syslog.h> 49 #include <sys/kernel.h> 50 #include <sys/namei.h> 51 #include <sys/errno.h> 52 #include <sys/acct.h> 53 #include <sys/resourcevar.h> 54 #include <sys/ioctl.h> 55 #include <sys/tty.h> 56 57 /* 58 * The routines implemented in this file are described in: 59 * Leffler, et al.: The Design and Implementation of the 4.3BSD 60 * UNIX Operating System (Addison Welley, 1989) 61 * on pages 62-63. 62 * 63 * Arguably, to simplify accounting operations, this mechanism should 64 * be replaced by one in which an accounting log file (similar to /dev/klog) 65 * is read by a user process, etc. However, that has its own problems. 66 */ 67 68 /* 69 * Internal accounting functions. 70 * The former's operation is described in Leffler, et al., and the latter 71 * was provided by UCB with the 4.4BSD-Lite release 72 */ 73 comp_t encode_comp_t __P((u_long, u_long)); 74 void acctwatch __P((void *)); 75 76 /* 77 * Accounting vnode pointer, and saved vnode pointer. 78 */ 79 struct vnode *acctp; 80 struct vnode *savacctp; 81 82 /* 83 * Values associated with enabling and disabling accounting 84 */ 85 int acctsuspend = 2; /* stop accounting when < 2% free space left */ 86 int acctresume = 4; /* resume when free space risen to > 4% */ 87 int acctchkfreq = 15; /* frequency (in seconds) to check space */ 88 89 /* 90 * Accounting system call. Written based on the specification and 91 * previous implementation done by Mark Tinguely. 92 */ 93 struct acct_args { 94 char *path; 95 }; 96 acct(p, uap, retval) 97 struct proc *p; 98 struct acct_args *uap; 99 int *retval; 100 { 101 struct nameidata nd; 102 int error; 103 104 /* Make sure that the caller is root. */ 105 if (error = suser(p->p_ucred, &p->p_acflag)) 106 return (error); 107 108 /* 109 * If accounting is to be started to a file, open that file for 110 * writing and make sure it's a 'normal'. 111 */ 112 if (uap->path != NULL) { 113 nd.ni_segflg = UIO_USERSPACE; 114 nd.ni_dirp = uap->path; 115 if (error = vn_open(&nd, p, FWRITE, 0)) 116 return (error); 117 VOP_UNLOCK(nd.ni_vp); 118 119 if (nd.ni_vp->v_type != VREG) { 120 vn_close(nd.ni_vp, FWRITE, p->p_ucred, p); 121 return (EACCES); 122 } 123 } 124 125 /* 126 * If accounting was previously enabled, kill the old space-watcher, 127 * close the file, and (if no new file was specified, leave). 128 */ 129 if (acctp != NULLVP || savacctp != NULLVP) { 130 untimeout(acctwatch, NULL); 131 error = vn_close((acctp != NULLVP ? acctp : savacctp), FWRITE, 132 p->p_ucred, p); 133 acctp = savacctp = NULLVP; 134 } 135 if (uap->path == NULL) 136 return (error); 137 138 /* 139 * Save the new accounting file vnode, and schedule the new 140 * free space watcher. 141 */ 142 acctp = nd.ni_vp; 143 acctwatch(NULL); 144 return (error); 145 } 146 147 /* 148 * Write out process accounting information, on process exit. 149 * Data to be written out is specified in Leffler, et al. 150 * and are enumerated below. (They're also noted in the system 151 * "acct.h" header file.) 152 */ 153 acct_process(p) 154 struct proc *p; 155 { 156 struct acct acct; 157 struct rusage *r; 158 struct timeval ut, st, tmp; 159 int s, t; 160 struct vnode *vp; 161 162 /* If accounting isn't enabled, don't bother */ 163 vp = acctp; 164 if (vp == NULLVP) 165 return (0); 166 167 /* 168 * Get process accounting information. 169 */ 170 171 /* (1) The name of the command that ran */ 172 bcopy(p->p_comm, acct.ac_comm, sizeof acct.ac_comm); 173 174 /* (2) The amount of user and system time that was used */ 175 calcru(p, &ut, &st, NULL); 176 acct.ac_utime = encode_comp_t(ut.tv_sec, ut.tv_usec); 177 acct.ac_stime = encode_comp_t(st.tv_sec, st.tv_usec); 178 179 /* (3) The elapsed time the commmand ran (and its starting time) */ 180 acct.ac_btime = p->p_stats->p_start.tv_sec; 181 s = splclock(); 182 tmp = time; 183 splx(s); 184 timevalsub(&tmp, &p->p_stats->p_start); 185 acct.ac_etime = encode_comp_t(tmp.tv_sec, tmp.tv_usec); 186 187 /* (4) The average amount of memory used */ 188 r = &p->p_stats->p_ru; 189 tmp = ut; 190 timevaladd(&tmp, &st); 191 t = tmp.tv_sec * hz + tmp.tv_usec / tick; 192 if (t) 193 acct.ac_mem = (r->ru_ixrss + r->ru_idrss + r->ru_isrss) / t; 194 else 195 acct.ac_mem = 0; 196 197 /* (5) The number of disk I/O 198 acct.ac_io = encode_comp_t(r->ru_inblock + r->ru_oublock, 0); 199 200 /* (6) The UID and GID of the process */ 201 acct.ac_uid = p->p_cred->p_ruid; 202 acct.ac_gid = p->p_cred->p_rgid; 203 204 /* (7) The terminal from which the process was started */ 205 if ((p->p_flag & P_CONTROLT) && p->p_pgrp->pg_session->s_ttyp) 206 acct.ac_tty = p->p_pgrp->pg_session->s_ttyp->t_dev; 207 else 208 acct.ac_tty = NODEV; 209 210 /* (8) The boolean flags that tell how the process terminated, etc. */ 211 acct.ac_flag = p->p_acflag; 212 213 /* 214 * Now, just write the accounting information to the file. 215 */ 216 LEASE_CHECK(vp, p, p->p_ucred, LEASE_WRITE); 217 return (vn_rdwr(UIO_WRITE, vp, (caddr_t)&acct, sizeof (acct), 218 (off_t)0, UIO_SYSSPACE, IO_APPEND|IO_UNIT, p->p_ucred, 219 (int *)0, p)); 220 } 221 222 /* 223 * Encode_comp_t converts from ticks in seconds and microseconds 224 * to ticks in 1/AHZ seconds. The encoding is described in 225 * Leffler, et al., on page 63. 226 */ 227 228 #define MANTSIZE 13 /* 13 bit mantissa. */ 229 #define EXPSIZE 3 /* Base 8 (3 bit) exponent. */ 230 #define MAXFRACT ((1 << MANTSIZE) - 1) /* Maximum fractional value. */ 231 232 comp_t 233 encode_comp_t(s, us) 234 u_long s, us; 235 { 236 int exp, rnd; 237 238 exp = 0; 239 rnd = 0; 240 s *= AHZ; 241 s += us / (1000000 / AHZ); /* Maximize precision. */ 242 243 while (s > MAXFRACT) { 244 rnd = s & (1 << (EXPSIZE - 1)); /* Round up? */ 245 s >>= EXPSIZE; /* Base 8 exponent == 3 bit shift. */ 246 exp++; 247 } 248 249 /* If we need to round up, do it (and handle overflow correctly). */ 250 if (rnd && (++s > MAXFRACT)) { 251 s >>= EXPSIZE; 252 exp++; 253 } 254 255 /* Clean it up and polish it off. */ 256 exp <<= MANTSIZE; /* Shift the exponent into place */ 257 exp += s; /* and add on the mantissa. */ 258 return (exp); 259 } 260 261 /* 262 * Periodically check the file system to see if accounting 263 * should be turned on or off. Beware the case where the vnode 264 * has been vgone()'d out from underneath us, e.g. when the file 265 * system containing the accounting file has been forcibly unmounted. 266 */ 267 /* ARGSUSED */ 268 void 269 acctwatch(a) 270 void *a; 271 { 272 struct statfs sb; 273 274 if (savacctp != NULLVP && savacctp->v_type != VBAD) { 275 (void)VFS_STATFS(savacctp->v_mount, &sb, (struct proc *)0); 276 if (sb.f_bavail > acctresume * sb.f_blocks / 100) { 277 acctp = savacctp; 278 savacctp = NULLVP; 279 log(LOG_NOTICE, "Accounting resumed\n"); 280 } 281 } else if (acctp != NULLVP && acctp->v_type != VBAD) { 282 (void)VFS_STATFS(acctp->v_mount, &sb, (struct proc *)0); 283 if (sb.f_bavail <= acctsuspend * sb.f_blocks / 100) { 284 savacctp = acctp; 285 acctp = NULLVP; 286 log(LOG_NOTICE, "Accounting suspended\n"); 287 } 288 } else 289 return; 290 timeout(acctwatch, NULL, acctchkfreq * hz); 291 } 292