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 * @(#)kern_acct.c 8.1 (Berkeley) 6/14/93 40 * $FreeBSD: src/sys/kern/kern_acct.c,v 1.23.2.1 2002/07/24 18:33:55 johan Exp $ 41 * $DragonFly: src/sys/kern/kern_acct.c,v 1.2 2003/06/17 04:28:41 dillon Exp $ 42 */ 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/sysproto.h> 47 #include <sys/proc.h> 48 #include <sys/mount.h> 49 #include <sys/vnode.h> 50 #include <sys/fcntl.h> 51 #include <sys/syslog.h> 52 #include <sys/kernel.h> 53 #include <sys/sysent.h> 54 #include <sys/sysctl.h> 55 #include <sys/namei.h> 56 #include <sys/acct.h> 57 #include <sys/resourcevar.h> 58 #include <sys/tty.h> 59 60 #include <vm/vm_zone.h> 61 62 /* 63 * The routines implemented in this file are described in: 64 * Leffler, et al.: The Design and Implementation of the 4.3BSD 65 * UNIX Operating System (Addison Welley, 1989) 66 * on pages 62-63. 67 * 68 * Arguably, to simplify accounting operations, this mechanism should 69 * be replaced by one in which an accounting log file (similar to /dev/klog) 70 * is read by a user process, etc. However, that has its own problems. 71 */ 72 73 /* 74 * Internal accounting functions. 75 * The former's operation is described in Leffler, et al., and the latter 76 * was provided by UCB with the 4.4BSD-Lite release 77 */ 78 static comp_t encode_comp_t __P((u_long, u_long)); 79 static void acctwatch __P((void *)); 80 81 /* 82 * Accounting callout handle used for periodic scheduling of 83 * acctwatch. 84 */ 85 static struct callout_handle acctwatch_handle 86 = CALLOUT_HANDLE_INITIALIZER(&acctwatch_handle); 87 88 /* 89 * Accounting vnode pointer, and saved vnode pointer. 90 */ 91 static struct vnode *acctp; 92 static struct vnode *savacctp; 93 94 /* 95 * Values associated with enabling and disabling accounting 96 */ 97 static int acctsuspend = 2; /* stop accounting when < 2% free space left */ 98 SYSCTL_INT(_kern, OID_AUTO, acct_suspend, CTLFLAG_RW, 99 &acctsuspend, 0, ""); 100 101 static int acctresume = 4; /* resume when free space risen to > 4% */ 102 SYSCTL_INT(_kern, OID_AUTO, acct_resume, CTLFLAG_RW, 103 &acctresume, 0, ""); 104 105 static int acctchkfreq = 15; /* frequency (in seconds) to check space */ 106 SYSCTL_INT(_kern, OID_AUTO, acct_chkfreq, CTLFLAG_RW, 107 &acctchkfreq, 0, ""); 108 109 /* 110 * Accounting system call. Written based on the specification and 111 * previous implementation done by Mark Tinguely. 112 */ 113 int 114 acct(a1, uap) 115 struct proc *a1; 116 struct acct_args /* { 117 syscallarg(char *) path; 118 } */ *uap; 119 { 120 struct proc *p = curproc; /* XXX */ 121 struct nameidata nd; 122 int error; 123 124 /* Make sure that the caller is root. */ 125 error = suser(p); 126 if (error) 127 return (error); 128 129 /* 130 * If accounting is to be started to a file, open that file for 131 * appending and make sure it's a 'normal'. 132 */ 133 if (SCARG(uap, path) != NULL) { 134 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_USERSPACE, SCARG(uap, path), 135 p); 136 error = vn_open(&nd, FWRITE | O_APPEND, 0); 137 if (error) 138 return (error); 139 NDFREE(&nd, NDF_ONLY_PNBUF); 140 VOP_UNLOCK(nd.ni_vp, 0, p); 141 if (nd.ni_vp->v_type != VREG) { 142 vn_close(nd.ni_vp, FWRITE | O_APPEND, p->p_ucred, p); 143 return (EACCES); 144 } 145 } 146 147 /* 148 * If accounting was previously enabled, kill the old space-watcher, 149 * close the file, and (if no new file was specified, leave). 150 */ 151 if (acctp != NULLVP || savacctp != NULLVP) { 152 untimeout(acctwatch, NULL, acctwatch_handle); 153 error = vn_close((acctp != NULLVP ? acctp : savacctp), 154 FWRITE | O_APPEND, p->p_ucred, p); 155 acctp = savacctp = NULLVP; 156 } 157 if (SCARG(uap, path) == NULL) 158 return (error); 159 160 /* 161 * Save the new accounting file vnode, and schedule the new 162 * free space watcher. 163 */ 164 acctp = nd.ni_vp; 165 acctwatch(NULL); 166 return (error); 167 } 168 169 /* 170 * Write out process accounting information, on process exit. 171 * Data to be written out is specified in Leffler, et al. 172 * and are enumerated below. (They're also noted in the system 173 * "acct.h" header file.) 174 */ 175 176 int 177 acct_process(p) 178 struct proc *p; 179 { 180 struct acct acct; 181 struct rusage *r; 182 struct timeval ut, st, tmp; 183 int t; 184 struct vnode *vp; 185 186 /* If accounting isn't enabled, don't bother */ 187 vp = acctp; 188 if (vp == NULLVP) 189 return (0); 190 191 /* 192 * Get process accounting information. 193 */ 194 195 /* (1) The name of the command that ran */ 196 bcopy(p->p_comm, acct.ac_comm, sizeof acct.ac_comm); 197 198 /* (2) The amount of user and system time that was used */ 199 calcru(p, &ut, &st, NULL); 200 acct.ac_utime = encode_comp_t(ut.tv_sec, ut.tv_usec); 201 acct.ac_stime = encode_comp_t(st.tv_sec, st.tv_usec); 202 203 /* (3) The elapsed time the commmand ran (and its starting time) */ 204 acct.ac_btime = p->p_stats->p_start.tv_sec; 205 microtime(&tmp); 206 timevalsub(&tmp, &p->p_stats->p_start); 207 acct.ac_etime = encode_comp_t(tmp.tv_sec, tmp.tv_usec); 208 209 /* (4) The average amount of memory used */ 210 r = &p->p_stats->p_ru; 211 tmp = ut; 212 timevaladd(&tmp, &st); 213 t = tmp.tv_sec * hz + tmp.tv_usec / tick; 214 if (t) 215 acct.ac_mem = (r->ru_ixrss + r->ru_idrss + r->ru_isrss) / t; 216 else 217 acct.ac_mem = 0; 218 219 /* (5) The number of disk I/O operations done */ 220 acct.ac_io = encode_comp_t(r->ru_inblock + r->ru_oublock, 0); 221 222 /* (6) The UID and GID of the process */ 223 acct.ac_uid = p->p_cred->p_ruid; 224 acct.ac_gid = p->p_cred->p_rgid; 225 226 /* (7) The terminal from which the process was started */ 227 if ((p->p_flag & P_CONTROLT) && p->p_pgrp->pg_session->s_ttyp) 228 acct.ac_tty = dev2udev(p->p_pgrp->pg_session->s_ttyp->t_dev); 229 else 230 acct.ac_tty = NOUDEV; 231 232 /* (8) The boolean flags that tell how the process terminated, etc. */ 233 acct.ac_flag = p->p_acflag; 234 235 /* 236 * Eliminate any file size rlimit. 237 */ 238 if (p->p_limit->p_refcnt > 1 && 239 (p->p_limit->p_lflags & PL_SHAREMOD) == 0) { 240 p->p_limit->p_refcnt--; 241 p->p_limit = limcopy(p->p_limit); 242 } 243 p->p_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY; 244 245 /* 246 * Write the accounting information to the file. 247 */ 248 VOP_LEASE(vp, p, p->p_ucred, LEASE_WRITE); 249 return (vn_rdwr(UIO_WRITE, vp, (caddr_t)&acct, sizeof (acct), 250 (off_t)0, UIO_SYSSPACE, IO_APPEND|IO_UNIT, p->p_ucred, 251 (int *)0, p)); 252 } 253 254 /* 255 * Encode_comp_t converts from ticks in seconds and microseconds 256 * to ticks in 1/AHZ seconds. The encoding is described in 257 * Leffler, et al., on page 63. 258 */ 259 260 #define MANTSIZE 13 /* 13 bit mantissa. */ 261 #define EXPSIZE 3 /* Base 8 (3 bit) exponent. */ 262 #define MAXFRACT ((1 << MANTSIZE) - 1) /* Maximum fractional value. */ 263 264 static comp_t 265 encode_comp_t(s, us) 266 u_long s, us; 267 { 268 int exp, rnd; 269 270 exp = 0; 271 rnd = 0; 272 s *= AHZ; 273 s += us / (1000000 / AHZ); /* Maximize precision. */ 274 275 while (s > MAXFRACT) { 276 rnd = s & (1 << (EXPSIZE - 1)); /* Round up? */ 277 s >>= EXPSIZE; /* Base 8 exponent == 3 bit shift. */ 278 exp++; 279 } 280 281 /* If we need to round up, do it (and handle overflow correctly). */ 282 if (rnd && (++s > MAXFRACT)) { 283 s >>= EXPSIZE; 284 exp++; 285 } 286 287 /* Clean it up and polish it off. */ 288 exp <<= MANTSIZE; /* Shift the exponent into place */ 289 exp += s; /* and add on the mantissa. */ 290 return (exp); 291 } 292 293 /* 294 * Periodically check the file system to see if accounting 295 * should be turned on or off. Beware the case where the vnode 296 * has been vgone()'d out from underneath us, e.g. when the file 297 * system containing the accounting file has been forcibly unmounted. 298 */ 299 /* ARGSUSED */ 300 static void 301 acctwatch(a) 302 void *a; 303 { 304 struct statfs sb; 305 306 if (savacctp != NULLVP) { 307 if (savacctp->v_type == VBAD) { 308 (void) vn_close(savacctp, FWRITE | O_APPEND, NOCRED, 309 NULL); 310 savacctp = NULLVP; 311 return; 312 } 313 (void)VFS_STATFS(savacctp->v_mount, &sb, (struct proc *)0); 314 if (sb.f_bavail > acctresume * sb.f_blocks / 100) { 315 acctp = savacctp; 316 savacctp = NULLVP; 317 log(LOG_NOTICE, "Accounting resumed\n"); 318 } 319 } else { 320 if (acctp == NULLVP) 321 return; 322 if (acctp->v_type == VBAD) { 323 (void) vn_close(acctp, FWRITE | O_APPEND, NOCRED, NULL); 324 acctp = NULLVP; 325 return; 326 } 327 (void)VFS_STATFS(acctp->v_mount, &sb, (struct proc *)0); 328 if (sb.f_bavail <= acctsuspend * sb.f_blocks / 100) { 329 savacctp = acctp; 330 acctp = NULLVP; 331 log(LOG_NOTICE, "Accounting suspended\n"); 332 } 333 } 334 acctwatch_handle = timeout(acctwatch, NULL, acctchkfreq * hz); 335 } 336