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 (c) 1992, 2010, Oracle and/or its affiliates. All rights reserved.
23 */
24
25 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
26 /* All Rights Reserved */
27
28
29 #include <sys/types.h>
30 #include <sys/sysmacros.h>
31 #include <sys/param.h>
32 #include <sys/systm.h>
33 #include <sys/acct.h>
34 #include <sys/cred.h>
35 #include <sys/user.h>
36 #include <sys/errno.h>
37 #include <sys/file.h>
38 #include <sys/vnode.h>
39 #include <sys/debug.h>
40 #include <sys/proc.h>
41 #include <sys/resource.h>
42 #include <sys/session.h>
43 #include <sys/modctl.h>
44 #include <sys/syscall.h>
45 #include <sys/policy.h>
46 #include <sys/list.h>
47 #include <sys/time.h>
48 #include <sys/msacct.h>
49 #include <sys/zone.h>
50
51 /*
52 * Each zone has its own accounting settings (on or off) and associated
53 * file. The global zone is not special in this aspect; it will only
54 * generate records for processes that ran in the global zone. We could
55 * allow the global zone to record all activity on the system, but there
56 * would be no way of knowing the zone in which the processes executed.
57 * sysacct() is thus virtualized to only act on the caller's zone.
58 */
59 struct acct_globals {
60 struct acct acctbuf;
61 kmutex_t aclock;
62 struct vnode *acctvp;
63 list_node_t aclink;
64 };
65
66 /*
67 * We need a list of all accounting settings for all zones, so we can
68 * accurately determine if a file is in use for accounting (possibly by
69 * another zone).
70 */
71 static zone_key_t acct_zone_key;
72 static list_t acct_list;
73 kmutex_t acct_list_lock;
74
75 static struct sysent acctsysent = {
76 1,
77 SE_NOUNLOAD | SE_ARGC | SE_32RVAL1,
78 sysacct
79 };
80
81 static struct modlsys modlsys = {
82 &mod_syscallops, "acct(2) syscall", &acctsysent
83 };
84
85 #ifdef _SYSCALL32_IMPL
86 static struct modlsys modlsys32 = {
87 &mod_syscallops32, "32-bit acct(2) syscall", &acctsysent
88 };
89 #endif
90
91 static struct modlinkage modlinkage = {
92 MODREV_1,
93 &modlsys,
94 #ifdef _SYSCALL32_IMPL
95 &modlsys32,
96 #endif
97 NULL
98 };
99
100 /*ARGSUSED*/
101 static void *
102 acct_init(zoneid_t zoneid)
103 {
104 struct acct_globals *ag;
105
106 ag = kmem_alloc(sizeof (*ag), KM_SLEEP);
107 bzero(&ag->acctbuf, sizeof (ag->acctbuf));
108 mutex_init(&ag->aclock, NULL, MUTEX_DEFAULT, NULL);
109 ag->acctvp = NULL;
110
111 mutex_enter(&acct_list_lock);
112 list_insert_tail(&acct_list, ag);
113 mutex_exit(&acct_list_lock);
114 return (ag);
115 }
116
117 /* ARGSUSED */
118 static void
119 acct_shutdown(zoneid_t zoneid, void *arg)
120 {
121 struct acct_globals *ag = arg;
122
123 mutex_enter(&ag->aclock);
124 if (ag->acctvp) {
125 /*
126 * This needs to be done as a shutdown callback, otherwise this
127 * held vnode may cause filesystems to be busy, and the zone
128 * shutdown operation to fail.
129 */
130 (void) VOP_CLOSE(ag->acctvp, FWRITE, 1, (offset_t)0, kcred,
131 NULL);
132 VN_RELE(ag->acctvp);
133 }
134 ag->acctvp = NULL;
135 mutex_exit(&ag->aclock);
136 }
137
138 /*ARGSUSED*/
139 static void
140 acct_fini(zoneid_t zoneid, void *arg)
141 {
142 struct acct_globals *ag = arg;
143
144 mutex_enter(&acct_list_lock);
145 list_remove(&acct_list, ag);
146 mutex_exit(&acct_list_lock);
147
148 mutex_destroy(&ag->aclock);
149 kmem_free(ag, sizeof (*ag));
150 }
151
152 int
153 _init(void)
154 {
155 int error;
156
157 mutex_init(&acct_list_lock, NULL, MUTEX_DEFAULT, NULL);
158 list_create(&acct_list, sizeof (struct acct_globals),
159 offsetof(struct acct_globals, aclink));
160 /*
161 * Using an initializer here wastes a bit of memory for zones that
162 * don't use accounting, but vastly simplifies the locking.
163 */
164 zone_key_create(&acct_zone_key, acct_init, acct_shutdown, acct_fini);
165 if ((error = mod_install(&modlinkage)) != 0) {
166 (void) zone_key_delete(acct_zone_key);
167 list_destroy(&acct_list);
168 mutex_destroy(&acct_list_lock);
169 }
170 return (error);
171 }
172
173 int
174 _info(struct modinfo *modinfop)
175 {
176 return (mod_info(&modlinkage, modinfop));
177 }
178
179 /*
180 * acct() is a "weak stub" routine called from exit().
181 * Once this module has been loaded, we refuse to allow
182 * it to unload - otherwise accounting would quietly
183 * cease. See 1211661. It's possible to make this module
184 * unloadable but it's substantially safer not to bother.
185 */
186 int
187 _fini(void)
188 {
189 return (EBUSY);
190 }
191
192 /*
193 * See if vp is in use by the accounting system on any zone. This does a deep
194 * comparison of vnodes such that a file and a lofs "shadow" node of it will
195 * appear to be the same.
196 *
197 * If 'compare_vfs' is true, the function will do a comparison of vfs_t's
198 * instead (ie, is the vfs_t on which the vnode resides in use by the
199 * accounting system in any zone).
200 *
201 * Returns 1 if found (in use), 0 otherwise.
202 */
203 static int
204 acct_find(vnode_t *vp, boolean_t compare_vfs)
205 {
206 struct acct_globals *ag;
207 vnode_t *realvp;
208
209 ASSERT(MUTEX_HELD(&acct_list_lock));
210 ASSERT(vp != NULL);
211
212 if (VOP_REALVP(vp, &realvp, NULL))
213 realvp = vp;
214 for (ag = list_head(&acct_list); ag != NULL;
215 ag = list_next(&acct_list, ag)) {
216 vnode_t *racctvp;
217 boolean_t found = B_FALSE;
218
219 mutex_enter(&ag->aclock);
220 if (ag->acctvp == NULL) {
221 mutex_exit(&ag->aclock);
222 continue;
223 }
224 if (VOP_REALVP(ag->acctvp, &racctvp, NULL))
225 racctvp = ag->acctvp;
226 if (compare_vfs) {
227 if (racctvp->v_vfsp == realvp->v_vfsp)
228 found = B_TRUE;
229 } else {
230 if (VN_CMP(realvp, racctvp))
231 found = B_TRUE;
232 }
233 mutex_exit(&ag->aclock);
234 if (found)
235 return (1);
236 }
237 return (0);
238 }
239
240 /*
241 * Returns 1 if the vfs that vnode resides on is in use for the accounting
242 * subsystem, 0 otherwise.
243 */
244 int
245 acct_fs_in_use(vnode_t *vp)
246 {
247 int found;
248
249 if (vp == NULL)
250 return (0);
251 mutex_enter(&acct_list_lock);
252 found = acct_find(vp, B_TRUE);
253 mutex_exit(&acct_list_lock);
254 return (found);
255 }
256
257 /*
258 * Perform process accounting functions.
259 */
260 int
261 sysacct(char *fname)
262 {
263 struct acct_globals *ag;
264 struct vnode *vp;
265 int error = 0;
266
267 if (secpolicy_acct(CRED()) != 0)
268 return (set_errno(EPERM));
269
270 ag = zone_getspecific(acct_zone_key, curproc->p_zone);
271 ASSERT(ag != NULL);
272
273 if (fname == NULL) {
274 /*
275 * Close the file and stop accounting.
276 */
277 mutex_enter(&ag->aclock);
278 vp = ag->acctvp;
279 ag->acctvp = NULL;
280 mutex_exit(&ag->aclock);
281 if (vp) {
282 error = VOP_CLOSE(vp, FWRITE, 1, (offset_t)0, CRED(),
283 NULL);
284 VN_RELE(vp);
285 }
286 return (error == 0 ? 0 : set_errno(error));
287 }
288
289 /*
290 * Either (a) open a new file and begin accounting -or- (b)
291 * switch accounting from an old to a new file.
292 *
293 * (Open the file without holding aclock in case it
294 * sleeps (holding the lock prevents process exit).)
295 */
296 if ((error = vn_open(fname, UIO_USERSPACE, FWRITE,
297 0, &vp, (enum create)0, 0)) != 0) {
298 /* SVID compliance */
299 if (error == EISDIR)
300 error = EACCES;
301 return (set_errno(error));
302 }
303
304 if (vp->v_type != VREG) {
305 error = EACCES;
306 } else {
307 mutex_enter(&acct_list_lock);
308 if (acct_find(vp, B_FALSE)) {
309 error = EBUSY;
310 } else {
311 mutex_enter(&ag->aclock);
312 if (ag->acctvp) {
313 vnode_t *oldvp;
314
315 /*
316 * close old acctvp, and point acct()
317 * at new file by swapping vp and acctvp
318 */
319 oldvp = ag->acctvp;
320 ag->acctvp = vp;
321 vp = oldvp;
322 } else {
323 /*
324 * no existing file, start accounting ..
325 */
326 ag->acctvp = vp;
327 vp = NULL;
328 }
329 mutex_exit(&ag->aclock);
330 }
331 mutex_exit(&acct_list_lock);
332 }
333
334 if (vp) {
335 (void) VOP_CLOSE(vp, FWRITE, 1, (offset_t)0, CRED(), NULL);
336 VN_RELE(vp);
337 }
338 return (error == 0 ? 0 : set_errno(error));
339 }
340
341 /*
342 * Produce a pseudo-floating point representation
343 * with 3 bits base-8 exponent, 13 bits fraction.
344 */
345 static comp_t
346 acct_compress(ulong_t t)
347 {
348 int exp = 0, round = 0;
349
350 while (t >= 8192) {
351 exp++;
352 round = t & 04;
353 t >>= 3;
354 }
355 if (round) {
356 t++;
357 if (t >= 8192) {
358 t >>= 3;
359 exp++;
360 }
361 }
362 #ifdef _LP64
363 if (exp > 7) {
364 /* prevent wraparound */
365 t = 8191;
366 exp = 7;
367 }
368 #endif
369 return ((exp << 13) + t);
370 }
371
372 /*
373 * On exit, write a record on the accounting file.
374 */
375 void
376 acct(char st)
377 {
378 struct vnode *vp;
379 struct cred *cr;
380 struct proc *p;
381 user_t *ua;
382 struct vattr va;
383 ssize_t resid = 0;
384 int error;
385 struct acct_globals *ag;
386
387 /*
388 * If sysacct module is loaded when zone is in down state then
389 * the following function can return NULL.
390 */
391 ag = zone_getspecific(acct_zone_key, curproc->p_zone);
392 if (ag == NULL)
393 return;
394
395 mutex_enter(&ag->aclock);
396 if ((vp = ag->acctvp) == NULL) {
397 mutex_exit(&ag->aclock);
398 return;
399 }
400
401 /*
402 * This only gets called from exit after all lwp's have exited so no
403 * cred locking is needed.
404 */
405 p = curproc;
406 ua = PTOU(p);
407 bcopy(ua->u_comm, ag->acctbuf.ac_comm, sizeof (ag->acctbuf.ac_comm));
408 ag->acctbuf.ac_btime = ua->u_start.tv_sec;
409 ag->acctbuf.ac_utime = acct_compress(NSEC_TO_TICK(p->p_acct[LMS_USER]));
410 ag->acctbuf.ac_stime = acct_compress(
411 NSEC_TO_TICK(p->p_acct[LMS_SYSTEM] + p->p_acct[LMS_TRAP]));
412 ag->acctbuf.ac_etime = acct_compress(ddi_get_lbolt() - ua->u_ticks);
413 ag->acctbuf.ac_mem = acct_compress((ulong_t)ua->u_mem);
414 ag->acctbuf.ac_io = acct_compress((ulong_t)p->p_ru.ioch);
415 ag->acctbuf.ac_rw = acct_compress((ulong_t)(p->p_ru.inblock +
416 p->p_ru.oublock));
417 cr = CRED();
418 ag->acctbuf.ac_uid = crgetruid(cr);
419 ag->acctbuf.ac_gid = crgetrgid(cr);
420 (void) cmpldev(&ag->acctbuf.ac_tty, cttydev(p));
421 ag->acctbuf.ac_stat = st;
422 ag->acctbuf.ac_flag = (ua->u_acflag | AEXPND);
423
424 /*
425 * Save the size. If the write fails, reset the size to avoid
426 * corrupted acct files.
427 *
428 * Large Files: We deliberately prevent accounting files from
429 * exceeding the 2GB limit as none of the accounting commands are
430 * currently large file aware.
431 */
432 va.va_mask = AT_SIZE;
433 if (VOP_GETATTR(vp, &va, 0, kcred, NULL) == 0) {
434 error = vn_rdwr(UIO_WRITE, vp, (caddr_t)&ag->acctbuf,
435 sizeof (ag->acctbuf), 0LL, UIO_SYSSPACE, FAPPEND,
436 (rlim64_t)MAXOFF32_T, kcred, &resid);
437 if (error || resid)
438 (void) VOP_SETATTR(vp, &va, 0, kcred, NULL);
439 }
440 mutex_exit(&ag->aclock);
441 }