xref: /titanic_41/usr/src/cmd/svc/startd/utmpx.c (revision 59ac0c1669407488b67ae9e273667a340dccc611)
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, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 /*
30  * utmpx.c - utmpx utility routines
31  *
32  * Since svc.startd(1M) places utmpx records for its launched instances, it must
33  * also mark them as dead once completed.
34  */
35 
36 #include <sys/stat.h>
37 #include <sys/types.h>
38 #include <sys/wait.h>
39 #include <sys/stat.h>
40 #include <errno.h>
41 #include <pthread.h>
42 #include <sac.h>
43 #include <string.h>
44 #include <strings.h>
45 #include <time.h>
46 #include <unistd.h>
47 #include <utmpx.h>
48 #include <fcntl.h>
49 
50 #include "startd.h"
51 
52 static const char rlevels[] = { 'S', '0', '1', '2', '3', '4', '5', '6', 0 };
53 static int n_prev[] = { 0, 0, 0, 0, 0, 0, 0, 0 };
54 
55 static pthread_mutex_t utmpx_lock;
56 static int utmpx_truncated = 0;
57 
58 #define	USEC_PER_MSEC	1000
59 
60 int
61 utmpx_mark_init(pid_t pid, char *prefix)
62 {
63 	struct utmpx ut, *oldu;
64 	int tmplen;
65 	int ret;
66 
67 	while (st->st_initial && !utmpx_truncated)
68 		(void) usleep(200 * USEC_PER_MSEC);
69 
70 	/*
71 	 * Clean out any preexisting records for this PID, as they must be
72 	 * inaccurate.
73 	 */
74 	utmpx_mark_dead(pid, 0, B_TRUE);
75 
76 	/*
77 	 * Construct a new record with the appropriate prefix.
78 	 */
79 	(void) memset(&ut, 0, sizeof (ut));
80 	(void) strncpy(ut.ut_user, ".startd", sizeof (ut.ut_user));
81 	ut.ut_pid = pid;
82 
83 	ut.ut_id[0] = ut.ut_id[1] = ut.ut_id[2] = ut.ut_id[3] = (char)SC_WILDC;
84 
85 	for (ret = 0; ret < strlen(prefix); ret++)
86 		ut.ut_id[ret] = prefix[ret];
87 
88 	ut.ut_type = INIT_PROCESS;
89 	(void) time(&ut.ut_tv.tv_sec);
90 
91 	for (;;) {
92 		MUTEX_LOCK(&utmpx_lock);
93 		setutxent();
94 
95 		if ((oldu = getutxid(&ut)) != NULL) {
96 			/*
97 			 * Copy in the old "line" and "host" fields.
98 			 */
99 			bcopy(oldu->ut_line, ut.ut_line, sizeof (ut.ut_line));
100 			bcopy(oldu->ut_host, ut.ut_host, sizeof (ut.ut_host));
101 			ut.ut_syslen = (tmplen = strlen(ut.ut_host)) ?
102 			    min(tmplen + 1, sizeof (ut.ut_host)) : 0;
103 		}
104 
105 		if (makeutx(&ut) != NULL)
106 			break;
107 
108 		if (errno != EROFS)
109 			log_framework(LOG_WARNING,
110 			    "makeutx failed, retrying: %s\n", strerror(errno));
111 
112 		MUTEX_UNLOCK(&utmpx_lock);
113 
114 		(void) sleep(1);
115 	}
116 
117 	updwtmpx(WTMPX_FILE, &ut);
118 
119 	endutxent();
120 	MUTEX_UNLOCK(&utmpx_lock);
121 
122 	return (ret);
123 }
124 
125 void
126 utmpx_mark_dead(pid_t pid, int status, boolean_t blocking)
127 {
128 	struct utmpx *up;
129 	int logged = 0;
130 
131 	for (;;) {
132 		int found = 0;
133 
134 		MUTEX_LOCK(&utmpx_lock);
135 		setutxent();
136 
137 		while (up = getutxent()) {
138 			if (up->ut_pid == pid) {
139 				found = 1;
140 
141 				if (up->ut_type == DEAD_PROCESS) {
142 					/*
143 					 * Cleaned up elsewhere.
144 					 */
145 					endutxent();
146 					MUTEX_UNLOCK(&utmpx_lock);
147 					return;
148 				}
149 
150 				up->ut_type = DEAD_PROCESS;
151 				up->ut_exit.e_termination = WTERMSIG(status);
152 				up->ut_exit.e_exit = WEXITSTATUS(status);
153 				(void) time(&up->ut_tv.tv_sec);
154 
155 				if (pututxline(up) != NULL) {
156 					/*
157 					 * Now attempt to add to the end of the
158 					 * wtmp and wtmpx files.  Do not create
159 					 * if they don't already exist.
160 					 */
161 					updwtmpx(WTMPX_FILE, up);
162 					endutxent();
163 					MUTEX_UNLOCK(&utmpx_lock);
164 
165 					return;
166 				}
167 			}
168 		}
169 
170 		endutxent();
171 		MUTEX_UNLOCK(&utmpx_lock);
172 
173 		if (!found || !blocking)
174 			return;
175 
176 		if (!logged) {
177 			log_framework(LOG_INFO, "retrying utmpx_dead on PID "
178 			    "%ld\n", pid);
179 			logged++;
180 		}
181 
182 		(void) sleep(1);
183 	}
184 }
185 
186 static void
187 utmpx_check()
188 {
189 	struct stat sb;
190 
191 	if (stat(_UTMPX_FILE, &sb) == 0 &&
192 	    sb.st_mode != (S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH))
193 		(void) chmod(_UTMPX_FILE, S_IRUSR | S_IWUSR | S_IRGRP |
194 		    S_IROTH);
195 
196 	if (stat(_WTMPX_FILE, &sb) == 0 &&
197 	    sb.st_mode != (S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH))
198 		(void) chmod(_WTMPX_FILE, S_IRUSR | S_IWUSR | S_IRGRP |
199 		    S_IROTH);
200 }
201 
202 /*
203  * Retrieve the runlevel utmpx entry if there is one; used to recover
204  * state when svc.startd is restarted.
205  */
206 char
207 utmpx_get_runlevel(void)
208 {
209 	struct utmpx *up;
210 	char rl = '\0';
211 
212 	MUTEX_LOCK(&utmpx_lock);
213 	setutxent();
214 
215 	while (up = getutxent()) {
216 		if (up->ut_type == RUN_LVL &&
217 		    sscanf(up->ut_line, RUNLVL_MSG, &rl) == 1)
218 			break;
219 	}
220 	endutxent();
221 	MUTEX_UNLOCK(&utmpx_lock);
222 
223 	return (rl);
224 }
225 
226 void
227 utmpx_set_runlevel(char runlevel, char oldrl, boolean_t do_bump)
228 {
229 	struct utmpx u;
230 	struct utmpx *oup;
231 	size_t tmplen;
232 	int i;
233 
234 	if (runlevel == 's')
235 		runlevel = 'S';
236 	if (oldrl == 's')
237 		oldrl = 'S';
238 
239 	bzero(&u, sizeof (struct utmpx));
240 
241 	u.ut_id[0] = u.ut_id[1] = u.ut_id[2] = u.ut_id[3] = '\0';
242 	u.ut_pid = 0;
243 	u.ut_type = RUN_LVL;
244 
245 	(void) time(&u.ut_tv.tv_sec);
246 
247 	MUTEX_LOCK(&utmpx_lock);
248 	setutxent();
249 
250 	if ((oup = getutxid(&u)) != NULL) {
251 		bcopy(oup->ut_host, u.ut_host, sizeof (u.ut_host));
252 		bcopy(oup->ut_line, u.ut_line, sizeof (u.ut_line));
253 		bcopy(oup->ut_user, u.ut_user, sizeof (u.ut_user));
254 
255 		tmplen = strlen(u.ut_host);
256 		if (tmplen)
257 			u.ut_syslen = min(tmplen + 1, sizeof (u.ut_host));
258 		else
259 			u.ut_syslen =  0;
260 	}
261 
262 	if (oldrl != '\0')
263 		u.ut_exit.e_exit = oldrl;
264 	else if (oup != NULL)
265 		u.ut_exit.e_exit = oup->ut_exit.e_termination;
266 	else
267 		u.ut_exit.e_exit = '0';
268 
269 	u.ut_exit.e_termination = runlevel;
270 
271 	for (i = 0; rlevels[i] != '\0'; ++i) {
272 		if (rlevels[i] == runlevel)
273 			break;
274 	}
275 
276 	u.ut_pid = n_prev[i];
277 
278 	if (do_bump) {
279 		for (i = 0; rlevels[i] != '\0'; ++i) {
280 			if (rlevels[i] == u.ut_exit.e_exit)
281 				break;
282 		}
283 
284 		++n_prev[i];
285 	}
286 
287 	(void) sprintf(u.ut_line, RUNLVL_MSG, runlevel);
288 
289 	if (pututxline(&u) == NULL) {
290 		endutxent();
291 		MUTEX_UNLOCK(&utmpx_lock);
292 
293 		return;
294 	}
295 
296 	updwtmpx(WTMPX_FILE, &u);
297 
298 	endutxent();
299 	MUTEX_UNLOCK(&utmpx_lock);
300 
301 	utmpx_check();
302 }
303 
304 static void
305 utmpx_write_entry(short type, const char *msg, time_t tstamp)
306 {
307 	struct utmpx u;
308 	struct utmpx *oup;
309 	size_t tmplen;
310 
311 	bzero(&u, sizeof (struct utmpx));
312 
313 	u.ut_id[0] = u.ut_id[1] = u.ut_id[2] = u.ut_id[3] = '\0';
314 	u.ut_pid = 0;
315 
316 	u.ut_exit.e_termination = WTERMSIG(0);
317 	u.ut_exit.e_exit = WEXITSTATUS(0);
318 	u.ut_type = type;
319 	u.ut_tv.tv_sec = tstamp;
320 
321 	MUTEX_LOCK(&utmpx_lock);
322 	setutxent();
323 
324 	if ((oup = getutxid(&u)) != NULL) {
325 		bcopy(oup->ut_user, u.ut_user, sizeof (u.ut_user));
326 		bcopy(oup->ut_line, u.ut_line, sizeof (u.ut_line));
327 		bcopy(oup->ut_host, u.ut_host, sizeof (u.ut_host));
328 
329 		tmplen = strlen(u.ut_host);
330 		if (tmplen)
331 			u.ut_syslen = min(tmplen + 1, sizeof (u.ut_host));
332 		else
333 			u.ut_syslen =  0;
334 	}
335 
336 	(void) sprintf(u.ut_line, "%.12s", msg);
337 
338 	if (pututxline(&u) == NULL) {
339 		endutxent();
340 		MUTEX_UNLOCK(&utmpx_lock);
341 
342 		return;
343 	}
344 
345 	updwtmpx(WTMPX_FILE, &u);
346 
347 	endutxent();
348 	MUTEX_UNLOCK(&utmpx_lock);
349 
350 	utmpx_check();
351 }
352 
353 void
354 utmpx_write_boottime(void)
355 {
356 	time_t tstamp;
357 	struct stat stbuf;
358 
359 	/*
360 	 * The DOWN_TIME record tracks when the OS became unavailable
361 	 * during the previous boot.  We stat(2) WTMPX and check its
362 	 * attributes to determine when (and how) the OS became
363 	 * unavailable.  If the file is empty, skip writing a DOWN_TIME
364 	 * record.  Otherwise, check the access and modify times and
365 	 * use whichever is latest as the time that the OS became
366 	 * unavailable.  If st_atime is latest, the instance crashed or
367 	 * the machine lost power.  If st_mtime is latest, the shutdown
368 	 * was controlled.
369 	 */
370 	if (stat(WTMPX_FILE, &stbuf) == 0 && stbuf.st_size != 0) {
371 		tstamp = (stbuf.st_atime >= stbuf.st_mtime) ?
372 		    stbuf.st_atime : stbuf.st_mtime;
373 		utmpx_write_entry(DOWN_TIME, DOWN_MSG, tstamp);
374 	}
375 
376 	/*
377 	 * The boot time (or start time, for a non-global zone) is retrieved in
378 	 * log_init().
379 	 */
380 	tstamp = st->st_start_time.tv_sec;
381 
382 	utmpx_write_entry(BOOT_TIME, BOOT_MSG, tstamp);
383 }
384 
385 /*
386  * void utmpx_clear_old(void)
387  *   At boot and only at boot, truncate the utmpx file.
388  *
389  */
390 void
391 utmpx_clear_old(void)
392 {
393 	int fd;
394 	mode_t mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH;
395 
396 	if (!st->st_initial || utmpx_truncated)
397 		return;
398 
399 	MUTEX_LOCK(&utmpx_lock);
400 
401 	if ((fd = open(_UTMPX_FILE,
402 	    O_WRONLY | O_CREAT | O_TRUNC, mode)) != -1) {
403 		(void) fchmod(fd, mode); /* force mode regardless of umask() */
404 		(void) fchown(fd, 0, 2); /* force owner to root/bin */
405 		(void) close(fd);
406 	} else {
407 		log_framework(LOG_NOTICE, "Unable to create %s: %s\n",
408 		    _UTMPX_FILE, strerror(errno));
409 	}
410 
411 	utmpx_truncated = 1;
412 
413 	MUTEX_UNLOCK(&utmpx_lock);
414 }
415 
416 void
417 utmpx_init()
418 {
419 	(void) pthread_mutex_init(&utmpx_lock, &mutex_attrs);
420 }
421