xref: /freebsd/usr.bin/last/last.c (revision 1669d8afc64812c8d2d1d147ae1fd42ff441e1b1)
1 /*
2  * Copyright (c) 1987, 1993, 1994
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #ifndef lint
35 static const char copyright[] =
36 "@(#) Copyright (c) 1987, 1993, 1994\n\
37 	The Regents of the University of California.  All rights reserved.\n";
38 #endif /* not lint */
39 
40 #ifndef lint
41 static const char sccsid[] = "@(#)last.c	8.2 (Berkeley) 4/2/94";
42 #endif /* not lint */
43 #include <sys/cdefs.h>
44 __FBSDID("$FreeBSD$");
45 
46 #include <sys/param.h>
47 #include <sys/stat.h>
48 
49 #include <err.h>
50 #include <errno.h>
51 #include <fcntl.h>
52 #include <langinfo.h>
53 #include <locale.h>
54 #include <paths.h>
55 #include <signal.h>
56 #include <stdio.h>
57 #include <stdlib.h>
58 #include <string.h>
59 #include <time.h>
60 #include <timeconv.h>
61 #include <unistd.h>
62 #include <utmp.h>
63 #include <sys/queue.h>
64 
65 #define	NO	0				/* false/no */
66 #define	YES	1				/* true/yes */
67 #define	ATOI2(ar)	((ar)[0] - '0') * 10 + ((ar)[1] - '0'); (ar) += 2;
68 
69 static struct utmp	buf[1024];		/* utmp read buffer */
70 
71 typedef struct arg {
72 	char	*name;				/* argument */
73 #define	HOST_TYPE	-2
74 #define	TTY_TYPE	-3
75 #define	USER_TYPE	-4
76 	int	type;				/* type of arg */
77 	struct arg	*next;			/* linked list pointer */
78 } ARG;
79 ARG	*arglist;				/* head of linked list */
80 
81 LIST_HEAD(ttylisthead, ttytab) ttylist;
82 
83 struct ttytab {
84 	time_t	logout;				/* log out time */
85 	char	tty[UT_LINESIZE + 1];		/* terminal name */
86 	LIST_ENTRY(ttytab) list;
87 };
88 
89 static const	char *crmsg;			/* cause of last reboot */
90 static long	currentout,			/* current logout value */
91 		maxrec;				/* records to display */
92 static const	char *file = _PATH_WTMP;		/* wtmp file */
93 static int	sflag = 0;			/* show delta in seconds */
94 static int	width = 5;			/* show seconds in delta */
95 static int	yflag;				/* show year */
96 static int      d_first;
97 static int	snapfound = 0;			/* found snapshot entry? */
98 static time_t	snaptime;			/* if != 0, we will only
99 						 * report users logged in
100 						 * at this snapshot time
101 						 */
102 
103 void	 addarg(int, char *);
104 time_t	 dateconv(char *);
105 void	 doentry(struct utmp *);
106 void	 hostconv(char *);
107 void	 onintr(int);
108 void	 printentry(struct utmp *, struct ttytab *);
109 char	*ttyconv(char *);
110 int	 want(struct utmp *);
111 void	 usage(void);
112 void	 wtmp(void);
113 
114 void
115 usage(void)
116 {
117 	(void)fprintf(stderr,
118 "usage: last [-swy] [-d [[CC]YY][MMDD]hhmm[.SS]] [-f file] [-h host]\n"
119 "            [-n maxrec] [-t tty] [user ...]\n");
120 	exit(1);
121 }
122 
123 int
124 main(int argc, char *argv[])
125 {
126 	int ch;
127 	char *p;
128 
129 	(void) setlocale(LC_TIME, "");
130 	d_first = (*nl_langinfo(D_MD_ORDER) == 'd');
131 
132 	maxrec = -1;
133 	snaptime = 0;
134 	while ((ch = getopt(argc, argv, "0123456789d:f:h:n:st:wy")) != -1)
135 		switch (ch) {
136 		case '0': case '1': case '2': case '3': case '4':
137 		case '5': case '6': case '7': case '8': case '9':
138 			/*
139 			 * kludge: last was originally designed to take
140 			 * a number after a dash.
141 			 */
142 			if (maxrec == -1) {
143 				p = strchr(argv[optind - 1], ch);
144 				if (p == NULL)
145 					p = strchr(argv[optind], ch);
146 				maxrec = atol(p);
147 				if (!maxrec)
148 					exit(0);
149 			}
150 			break;
151 		case 'd':
152 			snaptime = dateconv(optarg);
153 			break;
154 		case 'f':
155 			file = optarg;
156 			break;
157 		case 'h':
158 			hostconv(optarg);
159 			addarg(HOST_TYPE, optarg);
160 			break;
161 		case 'n':
162 			errno = 0;
163 			maxrec = strtol(optarg, &p, 10);
164 			if (p == optarg || *p != '\0' || errno != 0 ||
165 			    maxrec <= 0)
166 				errx(1, "%s: bad line count", optarg);
167 			break;
168 		case 's':
169 			sflag++;	/* Show delta as seconds */
170 			break;
171 		case 't':
172 			addarg(TTY_TYPE, ttyconv(optarg));
173 			break;
174 		case 'w':
175 			width = 8;
176 			break;
177 		case 'y':
178 			yflag++;
179 			break;
180 		case '?':
181 		default:
182 			usage();
183 		}
184 
185 	if (sflag && width == 8) usage();
186 
187 	if (argc) {
188 		setlinebuf(stdout);
189 		for (argv += optind; *argv; ++argv) {
190 #define	COMPATIBILITY
191 #ifdef	COMPATIBILITY
192 			/* code to allow "last p5" to work */
193 			addarg(TTY_TYPE, ttyconv(*argv));
194 #endif
195 			addarg(USER_TYPE, *argv);
196 		}
197 	}
198 	wtmp();
199 	exit(0);
200 }
201 
202 /*
203  * wtmp --
204  *	read through the wtmp file
205  */
206 void
207 wtmp(void)
208 {
209 	struct utmp	*bp;			/* current structure */
210 	struct stat	stb;			/* stat of file for size */
211 	long	bl;
212 	int	bytes, wfd;
213 	char ct[80];
214 	struct tm *tm;
215 	time_t	t;
216 
217 	LIST_INIT(&ttylist);
218 
219 	if ((wfd = open(file, O_RDONLY, 0)) < 0 || fstat(wfd, &stb) == -1)
220 		err(1, "%s", file);
221 	bl = (stb.st_size + sizeof(buf) - 1) / sizeof(buf);
222 
223 	(void)time(&t);
224 	buf[0].ut_time = _time_to_int(t);
225 	(void)signal(SIGINT, onintr);
226 	(void)signal(SIGQUIT, onintr);
227 
228 	while (--bl >= 0) {
229 		if (lseek(wfd, (off_t)(bl * sizeof(buf)), L_SET) == -1 ||
230 		    (bytes = read(wfd, buf, sizeof(buf))) == -1)
231 			err(1, "%s", file);
232 		for (bp = &buf[bytes / sizeof(buf[0]) - 1]; bp >= buf; --bp)
233 			doentry(bp);
234 	}
235 	t = _int_to_time(buf[0].ut_time);
236 	tm = localtime(&t);
237 	(void) strftime(ct, sizeof(ct), "\nwtmp begins %+\n", tm);
238 	printf("%s", ct);
239 }
240 
241 /*
242  * doentry --
243  *	process a single wtmp entry
244  */
245 void
246 doentry(struct utmp *bp)
247 {
248 	struct ttytab	*tt, *ttx;		/* ttylist entry */
249 
250 	/*
251 	 * if the terminal line is '~', the machine stopped.
252 	 * see utmp(5) for more info.
253 	 */
254 	if (bp->ut_line[0] == '~' && !bp->ut_line[1]) {
255 		/* everybody just logged out */
256 		for (tt = LIST_FIRST(&ttylist); tt;) {
257 			LIST_REMOVE(tt, list);
258 			ttx = tt;
259 			tt = LIST_NEXT(tt, list);
260 			free(ttx);
261 		}
262 		currentout = -bp->ut_time;
263 		crmsg = strncmp(bp->ut_name, "shutdown", UT_NAMESIZE) ?
264 		    "crash" : "shutdown";
265 		/*
266 		 * if we're in snapshot mode, we want to exit if this
267 		 * shutdown/reboot appears while we we are tracking the
268 		 * active range
269 		 */
270 		if (snaptime && snapfound)
271 			exit(0);
272 		/*
273 		 * don't print shutdown/reboot entries unless flagged for
274 		 */
275 		if (!snaptime && want(bp))
276 			printentry(bp, NULL);
277 		return;
278 	}
279 	/*
280 	 * if the line is '{' or '|', date got set; see
281 	 * utmp(5) for more info.
282 	 */
283 	if ((bp->ut_line[0] == '{' || bp->ut_line[0] == '|') &&
284 	    !bp->ut_line[1]) {
285 		if (want(bp) && !snaptime)
286 			printentry(bp, NULL);
287 		return;
288 	}
289 	/* find associated tty */
290 	LIST_FOREACH(tt, &ttylist, list)
291 	    if (!strncmp(tt->tty, bp->ut_line, UT_LINESIZE))
292 		    break;
293 
294 	if (tt == NULL) {
295 		/* add new one */
296 		tt = malloc(sizeof(struct ttytab));
297 		if (tt == NULL)
298 			errx(1, "malloc failure");
299 		tt->logout = currentout;
300 		strncpy(tt->tty, bp->ut_line, UT_LINESIZE);
301 		LIST_INSERT_HEAD(&ttylist, tt, list);
302 	}
303 
304 	/*
305 	 * print record if not in snapshot mode and wanted
306 	 * or in snapshot mode and in snapshot range
307 	 */
308 	if (bp->ut_name[0] && (want(bp) || (bp->ut_time < snaptime &&
309 	    (tt->logout > snaptime || tt->logout < 1)))) {
310 		snapfound = 1;
311 		/*
312 		 * when uucp and ftp log in over a network, the entry in
313 		 * the utmp file is the name plus their process id.  See
314 		 * etc/ftpd.c and usr.bin/uucp/uucpd.c for more information.
315 		 */
316 		if (!strncmp(bp->ut_line, "ftp", sizeof("ftp") - 1))
317 			bp->ut_line[3] = '\0';
318 		else if (!strncmp(bp->ut_line, "uucp", sizeof("uucp") - 1))
319 			bp->ut_line[4] = '\0';
320 		printentry(bp, tt);
321 	}
322 	tt->logout = bp->ut_time;
323 }
324 
325 /*
326  * printentry --
327  *	output an entry
328  *
329  * If `tt' is non-NULL, use it and `crmsg' to print the logout time or
330  * logout type (crash/shutdown) as appropriate.
331  */
332 void
333 printentry(struct utmp *bp, struct ttytab *tt)
334 {
335 	char ct[80];
336 	struct tm *tm;
337 	time_t	delta;				/* time difference */
338 	time_t	t;
339 
340 	if (maxrec != -1 && !maxrec--)
341 		exit(0);
342 	t = _int_to_time(bp->ut_time);
343 	tm = localtime(&t);
344 	(void) strftime(ct, sizeof(ct), d_first ?
345 	    (yflag ? "%a %e %b %Y %R" : "%a %e %b %R") :
346 	    (yflag ? "%a %b %e %Y %R" : "%a %b %e %R"), tm);
347 	printf("%-*.*s %-*.*s %-*.*s %s%c",
348 	    UT_NAMESIZE, UT_NAMESIZE, bp->ut_name,
349 	    UT_LINESIZE, UT_LINESIZE, bp->ut_line,
350 	    UT_HOSTSIZE, UT_HOSTSIZE, bp->ut_host,
351 	    ct, tt == NULL ? '\n' : ' ');
352 	if (tt == NULL)
353 		return;
354 	if (!tt->logout) {
355 		puts("  still logged in");
356 		return;
357 	}
358 	if (tt->logout < 0) {
359 		tt->logout = -tt->logout;
360 		printf("- %s", crmsg);
361 	} else {
362 		tm = localtime(&tt->logout);
363 		(void) strftime(ct, sizeof(ct), "%R", tm);
364 		printf("- %s", ct);
365 	}
366 	delta = tt->logout - bp->ut_time;
367 	if (sflag) {
368 		printf("  (%8ld)\n", (long)delta);
369 	} else {
370 		tm = gmtime(&delta);
371 		(void) strftime(ct, sizeof(ct), width >= 8 ? "%T" : "%R", tm);
372 		if (delta < 86400)
373 			printf("  (%s)\n", ct);
374 		else
375 			printf(" (%ld+%s)\n", (long)delta / 86400, ct);
376 	}
377 }
378 
379 /*
380  * want --
381  *	see if want this entry
382  */
383 int
384 want(struct utmp *bp)
385 {
386 	ARG *step;
387 
388 	if (snaptime)
389 		return (NO);
390 
391 	if (!arglist)
392 		return (YES);
393 
394 	for (step = arglist; step; step = step->next)
395 		switch(step->type) {
396 		case HOST_TYPE:
397 			if (!strncasecmp(step->name, bp->ut_host, UT_HOSTSIZE))
398 				return (YES);
399 			break;
400 		case TTY_TYPE:
401 			if (!strncmp(step->name, bp->ut_line, UT_LINESIZE))
402 				return (YES);
403 			break;
404 		case USER_TYPE:
405 			if (!strncmp(step->name, bp->ut_name, UT_NAMESIZE))
406 				return (YES);
407 			break;
408 		}
409 	return (NO);
410 }
411 
412 /*
413  * addarg --
414  *	add an entry to a linked list of arguments
415  */
416 void
417 addarg(int type, char *arg)
418 {
419 	ARG *cur;
420 
421 	if ((cur = malloc(sizeof(ARG))) == NULL)
422 		errx(1, "malloc failure");
423 	cur->next = arglist;
424 	cur->type = type;
425 	cur->name = arg;
426 	arglist = cur;
427 }
428 
429 /*
430  * hostconv --
431  *	convert the hostname to search pattern; if the supplied host name
432  *	has a domain attached that is the same as the current domain, rip
433  *	off the domain suffix since that's what login(1) does.
434  */
435 void
436 hostconv(char *arg)
437 {
438 	static int first = 1;
439 	static char *hostdot, name[MAXHOSTNAMELEN];
440 	char *argdot;
441 
442 	if (!(argdot = strchr(arg, '.')))
443 		return;
444 	if (first) {
445 		first = 0;
446 		if (gethostname(name, sizeof(name)))
447 			err(1, "gethostname");
448 		hostdot = strchr(name, '.');
449 	}
450 	if (hostdot && !strcasecmp(hostdot, argdot))
451 		*argdot = '\0';
452 }
453 
454 /*
455  * ttyconv --
456  *	convert tty to correct name.
457  */
458 char *
459 ttyconv(char *arg)
460 {
461 	char *mval;
462 
463 	/*
464 	 * kludge -- we assume that all tty's end with
465 	 * a two character suffix.
466 	 */
467 	if (strlen(arg) == 2) {
468 		/* either 6 for "ttyxx" or 8 for "console" */
469 		if ((mval = malloc(8)) == NULL)
470 			errx(1, "malloc failure");
471 		if (!strcmp(arg, "co"))
472 			(void)strcpy(mval, "console");
473 		else {
474 			(void)strcpy(mval, "tty");
475 			(void)strcpy(mval + 3, arg);
476 		}
477 		return (mval);
478 	}
479 	if (!strncmp(arg, _PATH_DEV, sizeof(_PATH_DEV) - 1))
480 		return (arg + 5);
481 	return (arg);
482 }
483 
484 /*
485  * dateconv --
486  * 	Convert the snapshot time in command line given in the format
487  * 	[[CC]YY]MMDDhhmm[.SS]] to a time_t.
488  * 	Derived from atime_arg1() in usr.bin/touch/touch.c
489  */
490 time_t
491 dateconv(char *arg)
492 {
493         time_t timet;
494         struct tm *t;
495         int yearset;
496         char *p;
497 
498         /* Start with the current time. */
499         if (time(&timet) < 0)
500                 err(1, "time");
501         if ((t = localtime(&timet)) == NULL)
502                 err(1, "localtime");
503 
504         /* [[CC]YY]MMDDhhmm[.SS] */
505         if ((p = strchr(arg, '.')) == NULL)
506                 t->tm_sec = 0; 		/* Seconds defaults to 0. */
507         else {
508                 if (strlen(p + 1) != 2)
509                         goto terr;
510                 *p++ = '\0';
511                 t->tm_sec = ATOI2(p);
512         }
513 
514         yearset = 0;
515         switch (strlen(arg)) {
516         case 12:                	/* CCYYMMDDhhmm */
517                 t->tm_year = ATOI2(arg);
518                 t->tm_year *= 100;
519                 yearset = 1;
520                 /* FALLTHROUGH */
521         case 10:                	/* YYMMDDhhmm */
522                 if (yearset) {
523                         yearset = ATOI2(arg);
524                         t->tm_year += yearset;
525                 } else {
526                         yearset = ATOI2(arg);
527                         if (yearset < 69)
528                                 t->tm_year = yearset + 2000;
529                         else
530                                 t->tm_year = yearset + 1900;
531                 }
532                 t->tm_year -= 1900;     /* Convert to UNIX time. */
533                 /* FALLTHROUGH */
534         case 8:				/* MMDDhhmm */
535                 t->tm_mon = ATOI2(arg);
536                 --t->tm_mon;    	/* Convert from 01-12 to 00-11 */
537                 t->tm_mday = ATOI2(arg);
538                 t->tm_hour = ATOI2(arg);
539                 t->tm_min = ATOI2(arg);
540                 break;
541         case 4:				/* hhmm */
542                 t->tm_hour = ATOI2(arg);
543                 t->tm_min = ATOI2(arg);
544                 break;
545         default:
546                 goto terr;
547         }
548         t->tm_isdst = -1;       	/* Figure out DST. */
549         timet = mktime(t);
550         if (timet == -1)
551 terr:           errx(1,
552         "out of range or illegal time specification: [[CC]YY]MMDDhhmm[.SS]");
553         return timet;
554 }
555 
556 
557 /*
558  * onintr --
559  *	on interrupt, we inform the user how far we've gotten
560  */
561 void
562 onintr(int signo)
563 {
564 	char ct[80];
565 	struct tm *tm;
566 	time_t t = _int_to_time(buf[0].ut_time);
567 
568 	tm = localtime(&t);
569 	(void) strftime(ct, sizeof(ct),
570 			d_first ? "%a %e %b %R" : "%a %b %e %R",
571 			tm);
572 	printf("\ninterrupted %s\n", ct);
573 	if (signo == SIGINT)
574 		exit(1);
575 	(void)fflush(stdout);			/* fix required for rsh */
576 }
577