1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright 2007 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 26 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */ 27 /* All Rights Reserved */ 28 29 30 #pragma ident "%Z%%M% %I% %E% SMI" 31 32 #include <sys/types.h> 33 #include <sys/sysmacros.h> 34 #include <sys/param.h> 35 #include <sys/systm.h> 36 #include <sys/acct.h> 37 #include <sys/cred.h> 38 #include <sys/user.h> 39 #include <sys/errno.h> 40 #include <sys/file.h> 41 #include <sys/vnode.h> 42 #include <sys/debug.h> 43 #include <sys/proc.h> 44 #include <sys/resource.h> 45 #include <sys/session.h> 46 #include <sys/modctl.h> 47 #include <sys/syscall.h> 48 #include <sys/policy.h> 49 #include <sys/list.h> 50 #include <sys/time.h> 51 #include <sys/msacct.h> 52 #include <sys/zone.h> 53 54 /* 55 * Each zone has its own accounting settings (on or off) and associated 56 * file. The global zone is not special in this aspect; it will only 57 * generate records for processes that ran in the global zone. We could 58 * allow the global zone to record all activity on the system, but there 59 * would be no way of knowing the zone in which the processes executed. 60 * sysacct() is thus virtualized to only act on the caller's zone. 61 */ 62 struct acct_globals { 63 struct acct acctbuf; 64 kmutex_t aclock; 65 struct vnode *acctvp; 66 list_node_t aclink; 67 }; 68 69 /* 70 * We need a list of all accounting settings for all zones, so we can 71 * accurately determine if a file is in use for accounting (possibly by 72 * another zone). 73 */ 74 static zone_key_t acct_zone_key; 75 static list_t acct_list; 76 kmutex_t acct_list_lock; 77 78 static struct sysent acctsysent = { 79 1, 80 SE_NOUNLOAD | SE_ARGC | SE_32RVAL1, 81 sysacct 82 }; 83 84 static struct modlsys modlsys = { 85 &mod_syscallops, "acct(2) syscall", &acctsysent 86 }; 87 88 #ifdef _SYSCALL32_IMPL 89 static struct modlsys modlsys32 = { 90 &mod_syscallops32, "32-bit acct(2) syscall", &acctsysent 91 }; 92 #endif 93 94 static struct modlinkage modlinkage = { 95 MODREV_1, 96 &modlsys, 97 #ifdef _SYSCALL32_IMPL 98 &modlsys32, 99 #endif 100 NULL 101 }; 102 103 /*ARGSUSED*/ 104 static void * 105 acct_init(zoneid_t zoneid) 106 { 107 struct acct_globals *ag; 108 109 ag = kmem_alloc(sizeof (*ag), KM_SLEEP); 110 bzero(&ag->acctbuf, sizeof (ag->acctbuf)); 111 mutex_init(&ag->aclock, NULL, MUTEX_DEFAULT, NULL); 112 ag->acctvp = NULL; 113 114 mutex_enter(&acct_list_lock); 115 list_insert_tail(&acct_list, ag); 116 mutex_exit(&acct_list_lock); 117 return (ag); 118 } 119 120 /* ARGSUSED */ 121 static void 122 acct_shutdown(zoneid_t zoneid, void *arg) 123 { 124 struct acct_globals *ag = arg; 125 126 mutex_enter(&ag->aclock); 127 if (ag->acctvp) { 128 /* 129 * This needs to be done as a shutdown callback, otherwise this 130 * held vnode may cause filesystems to be busy, and the zone 131 * shutdown operation to fail. 132 */ 133 (void) VOP_CLOSE(ag->acctvp, FWRITE, 1, (offset_t)0, kcred); 134 VN_RELE(ag->acctvp); 135 } 136 ag->acctvp = NULL; 137 mutex_exit(&ag->aclock); 138 } 139 140 /*ARGSUSED*/ 141 static void 142 acct_fini(zoneid_t zoneid, void *arg) 143 { 144 struct acct_globals *ag = arg; 145 146 mutex_enter(&acct_list_lock); 147 list_remove(&acct_list, ag); 148 mutex_exit(&acct_list_lock); 149 150 mutex_destroy(&ag->aclock); 151 kmem_free(ag, sizeof (*ag)); 152 } 153 154 int 155 _init(void) 156 { 157 int error; 158 159 mutex_init(&acct_list_lock, NULL, MUTEX_DEFAULT, NULL); 160 list_create(&acct_list, sizeof (struct acct_globals), 161 offsetof(struct acct_globals, aclink)); 162 /* 163 * Using an initializer here wastes a bit of memory for zones that 164 * don't use accounting, but vastly simplifies the locking. 165 */ 166 zone_key_create(&acct_zone_key, acct_init, acct_shutdown, acct_fini); 167 if ((error = mod_install(&modlinkage)) != 0) { 168 (void) zone_key_delete(acct_zone_key); 169 list_destroy(&acct_list); 170 mutex_destroy(&acct_list_lock); 171 } 172 return (error); 173 } 174 175 int 176 _info(struct modinfo *modinfop) 177 { 178 return (mod_info(&modlinkage, modinfop)); 179 } 180 181 /* 182 * acct() is a "weak stub" routine called from exit(). 183 * Once this module has been loaded, we refuse to allow 184 * it to unload - otherwise accounting would quietly 185 * cease. See 1211661. It's possible to make this module 186 * unloadable but it's substantially safer not to bother. 187 */ 188 int 189 _fini(void) 190 { 191 return (EBUSY); 192 } 193 194 /* 195 * See if vp is in use by the accounting system on any zone. This does a deep 196 * comparison of vnodes such that a file and a lofs "shadow" node of it will 197 * appear to be the same. 198 * 199 * If 'compare_vfs' is true, the function will do a comparison of vfs_t's 200 * instead (ie, is the vfs_t on which the vnode resides in use by the 201 * accounting system in any zone). 202 * 203 * Returns 1 if found (in use), 0 otherwise. 204 */ 205 static int 206 acct_find(vnode_t *vp, boolean_t compare_vfs) 207 { 208 struct acct_globals *ag; 209 vnode_t *realvp; 210 211 ASSERT(MUTEX_HELD(&acct_list_lock)); 212 ASSERT(vp != NULL); 213 214 if (VOP_REALVP(vp, &realvp)) 215 realvp = vp; 216 for (ag = list_head(&acct_list); ag != NULL; 217 ag = list_next(&acct_list, ag)) { 218 vnode_t *racctvp; 219 boolean_t found = B_FALSE; 220 221 mutex_enter(&ag->aclock); 222 if (ag->acctvp == NULL) { 223 mutex_exit(&ag->aclock); 224 continue; 225 } 226 if (VOP_REALVP(ag->acctvp, &racctvp)) 227 racctvp = ag->acctvp; 228 if (compare_vfs) { 229 if (racctvp->v_vfsp == realvp->v_vfsp) 230 found = B_TRUE; 231 } else { 232 if (VN_CMP(realvp, racctvp)) 233 found = B_TRUE; 234 } 235 mutex_exit(&ag->aclock); 236 if (found) 237 return (1); 238 } 239 return (0); 240 } 241 242 /* 243 * Returns 1 if the vfs that vnode resides on is in use for the accounting 244 * subsystem, 0 otherwise. 245 */ 246 int 247 acct_fs_in_use(vnode_t *vp) 248 { 249 int found; 250 251 if (vp == NULL) 252 return (0); 253 mutex_enter(&acct_list_lock); 254 found = acct_find(vp, B_TRUE); 255 mutex_exit(&acct_list_lock); 256 return (found); 257 } 258 259 /* 260 * Perform process accounting functions. 261 */ 262 int 263 sysacct(char *fname) 264 { 265 struct acct_globals *ag; 266 struct vnode *vp; 267 int error = 0; 268 269 if (secpolicy_acct(CRED()) != 0) 270 return (set_errno(EPERM)); 271 272 ag = zone_getspecific(acct_zone_key, curproc->p_zone); 273 ASSERT(ag != NULL); 274 275 if (fname == NULL) { 276 /* 277 * Close the file and stop accounting. 278 */ 279 mutex_enter(&ag->aclock); 280 vp = ag->acctvp; 281 ag->acctvp = NULL; 282 mutex_exit(&ag->aclock); 283 if (vp) { 284 error = VOP_CLOSE(vp, FWRITE, 1, (offset_t)0, CRED()); 285 VN_RELE(vp); 286 } 287 return (error == 0 ? 0 : set_errno(error)); 288 } 289 290 /* 291 * Either (a) open a new file and begin accounting -or- (b) 292 * switch accounting from an old to a new file. 293 * 294 * (Open the file without holding aclock in case it 295 * sleeps (holding the lock prevents process exit).) 296 */ 297 if ((error = vn_open(fname, UIO_USERSPACE, FWRITE, 298 0, &vp, (enum create)0, 0)) != 0) { 299 /* SVID compliance */ 300 if (error == EISDIR) 301 error = EACCES; 302 return (set_errno(error)); 303 } 304 305 if (vp->v_type != VREG) { 306 error = EACCES; 307 } else { 308 mutex_enter(&acct_list_lock); 309 if (acct_find(vp, B_FALSE)) { 310 error = EBUSY; 311 } else { 312 mutex_enter(&ag->aclock); 313 if (ag->acctvp) { 314 vnode_t *oldvp; 315 316 /* 317 * close old acctvp, and point acct() 318 * at new file by swapping vp and acctvp 319 */ 320 oldvp = ag->acctvp; 321 ag->acctvp = vp; 322 vp = oldvp; 323 } else { 324 /* 325 * no existing file, start accounting .. 326 */ 327 ag->acctvp = vp; 328 vp = NULL; 329 } 330 mutex_exit(&ag->aclock); 331 } 332 mutex_exit(&acct_list_lock); 333 } 334 335 if (vp) { 336 (void) VOP_CLOSE(vp, FWRITE, 1, (offset_t)0, CRED()); 337 VN_RELE(vp); 338 } 339 return (error == 0 ? 0 : set_errno(error)); 340 } 341 342 /* 343 * Produce a pseudo-floating point representation 344 * with 3 bits base-8 exponent, 13 bits fraction. 345 */ 346 static comp_t 347 acct_compress(ulong_t t) 348 { 349 int exp = 0, round = 0; 350 351 while (t >= 8192) { 352 exp++; 353 round = t & 04; 354 t >>= 3; 355 } 356 if (round) { 357 t++; 358 if (t >= 8192) { 359 t >>= 3; 360 exp++; 361 } 362 } 363 #ifdef _LP64 364 if (exp > 7) { 365 /* prevent wraparound */ 366 t = 8191; 367 exp = 7; 368 } 369 #endif 370 return ((exp << 13) + t); 371 } 372 373 /* 374 * On exit, write a record on the accounting file. 375 */ 376 void 377 acct(char st) 378 { 379 struct vnode *vp; 380 struct cred *cr; 381 struct proc *p; 382 user_t *ua; 383 struct vattr va; 384 ssize_t resid = 0; 385 int error; 386 struct acct_globals *ag; 387 388 ag = zone_getspecific(acct_zone_key, curproc->p_zone); 389 390 mutex_enter(&ag->aclock); 391 if ((vp = ag->acctvp) == NULL) { 392 mutex_exit(&ag->aclock); 393 return; 394 } 395 396 /* 397 * This only gets called from exit after all lwp's have exited so no 398 * cred locking is needed. 399 */ 400 p = curproc; 401 ua = PTOU(p); 402 bcopy(ua->u_comm, ag->acctbuf.ac_comm, sizeof (ag->acctbuf.ac_comm)); 403 ag->acctbuf.ac_btime = ua->u_start.tv_sec; 404 ag->acctbuf.ac_utime = acct_compress(NSEC_TO_TICK(p->p_acct[LMS_USER])); 405 ag->acctbuf.ac_stime = acct_compress( 406 NSEC_TO_TICK(p->p_acct[LMS_SYSTEM] + p->p_acct[LMS_TRAP])); 407 ag->acctbuf.ac_etime = acct_compress(lbolt - ua->u_ticks); 408 ag->acctbuf.ac_mem = acct_compress((ulong_t)ua->u_mem); 409 ag->acctbuf.ac_io = acct_compress((ulong_t)p->p_ru.ioch); 410 ag->acctbuf.ac_rw = acct_compress((ulong_t)(p->p_ru.inblock + 411 p->p_ru.oublock)); 412 cr = CRED(); 413 ag->acctbuf.ac_uid = crgetruid(cr); 414 ag->acctbuf.ac_gid = crgetrgid(cr); 415 (void) cmpldev(&ag->acctbuf.ac_tty, cttydev(p)); 416 ag->acctbuf.ac_stat = st; 417 ag->acctbuf.ac_flag = (ua->u_acflag | AEXPND); 418 419 /* 420 * Save the size. If the write fails, reset the size to avoid 421 * corrupted acct files. 422 * 423 * Large Files: We deliberately prevent accounting files from 424 * exceeding the 2GB limit as none of the accounting commands are 425 * currently large file aware. 426 */ 427 va.va_mask = AT_SIZE; 428 if (VOP_GETATTR(vp, &va, 0, kcred) == 0) { 429 error = vn_rdwr(UIO_WRITE, vp, (caddr_t)&ag->acctbuf, 430 sizeof (ag->acctbuf), 0LL, UIO_SYSSPACE, FAPPEND, 431 (rlim64_t)MAXOFF32_T, kcred, &resid); 432 if (error || resid) 433 (void) VOP_SETATTR(vp, &va, 0, kcred, NULL); 434 } 435 mutex_exit(&ag->aclock); 436 } 437