xref: /freebsd/usr.bin/last/last.c (revision 6780ab54325a71e7e70112b11657973edde8655e)
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 <fcntl.h>
51 #include <langinfo.h>
52 #include <locale.h>
53 #include <paths.h>
54 #include <signal.h>
55 #include <stdio.h>
56 #include <stdlib.h>
57 #include <string.h>
58 #include <time.h>
59 #include <unistd.h>
60 #include <utmp.h>
61 #include <sys/queue.h>
62 
63 #define	NO	0				/* false/no */
64 #define	YES	1				/* true/yes */
65 #define	ATOI2(ar)	((ar)[0] - '0') * 10 + ((ar)[1] - '0'); (ar) += 2;
66 
67 static struct utmp	buf[1024];		/* utmp read buffer */
68 
69 typedef struct arg {
70 	char	*name;				/* argument */
71 #define	HOST_TYPE	-2
72 #define	TTY_TYPE	-3
73 #define	USER_TYPE	-4
74 	int	type;				/* type of arg */
75 	struct arg	*next;			/* linked list pointer */
76 } ARG;
77 ARG	*arglist;				/* head of linked list */
78 
79 LIST_HEAD(ttylisthead, ttytab) ttylist;
80 
81 struct ttytab {
82 	time_t	logout;				/* log out time */
83 	char	tty[UT_LINESIZE + 1];		/* terminal name */
84 	LIST_ENTRY(ttytab) list;
85 };
86 
87 static const	char *crmsg;			/* cause of last reboot */
88 static long	currentout,			/* current logout value */
89 		maxrec;				/* records to display */
90 static const	char *file = _PATH_WTMP;		/* wtmp file */
91 static int	sflag = 0;			/* show delta in seconds */
92 static int	width = 5;			/* show seconds in delta */
93 static int	yflag;				/* show year */
94 static int      d_first;
95 static int	snapfound = 0;			/* found snapshot entry? */
96 static time_t	snaptime;			/* if != 0, we will only
97 						 * report users logged in
98 						 * at this snapshot time
99 						 */
100 
101 void	 addarg(int, char *);
102 time_t	 dateconv(char *);
103 void	 doentry(struct utmp *);
104 void	 hostconv(char *);
105 void	 onintr(int);
106 void	 printentry(struct utmp *, struct ttytab *);
107 char	*ttyconv(char *);
108 int	 want(struct utmp *);
109 void	 usage(void);
110 void	 wtmp(void);
111 
112 void
113 usage(void)
114 {
115 	(void)fprintf(stderr,
116 "usage: last [-#] [-y] [-d [[CC]YY][MMDD]hhmm[.SS]] [-f file] [-h host]\n"
117 "\t[-t tty] [-s|w] [user ...]\n");
118 	exit(1);
119 }
120 
121 int
122 main(int argc, char *argv[])
123 {
124 	int ch;
125 	char *p;
126 
127 	(void) setlocale(LC_TIME, "");
128 	d_first = (*nl_langinfo(D_MD_ORDER) == 'd');
129 
130 	maxrec = -1;
131 	snaptime = 0;
132 	while ((ch = getopt(argc, argv, "0123456789d:f:h:st:wy")) != -1)
133 		switch (ch) {
134 		case '0': case '1': case '2': case '3': case '4':
135 		case '5': case '6': case '7': case '8': case '9':
136 			/*
137 			 * kludge: last was originally designed to take
138 			 * a number after a dash.
139 			 */
140 			if (maxrec == -1) {
141 				p = strchr(argv[optind - 1], ch);
142 				if (p == NULL)
143 					p = strchr(argv[optind], ch);
144 				maxrec = atol(p);
145 				if (!maxrec)
146 					exit(0);
147 			}
148 			break;
149 		case 'd':
150 			snaptime = dateconv(optarg);
151 			break;
152 		case 'f':
153 			file = optarg;
154 			break;
155 		case 'h':
156 			hostconv(optarg);
157 			addarg(HOST_TYPE, optarg);
158 			break;
159 		case 's':
160 			sflag++;	/* Show delta as seconds */
161 			break;
162 		case 't':
163 			addarg(TTY_TYPE, ttyconv(optarg));
164 			break;
165 		case 'w':
166 			width = 8;
167 			break;
168 		case 'y':
169 			yflag++;
170 			break;
171 		case '?':
172 		default:
173 			usage();
174 		}
175 
176 	if (sflag && width == 8) usage();
177 
178 	if (argc) {
179 		setlinebuf(stdout);
180 		for (argv += optind; *argv; ++argv) {
181 #define	COMPATIBILITY
182 #ifdef	COMPATIBILITY
183 			/* code to allow "last p5" to work */
184 			addarg(TTY_TYPE, ttyconv(*argv));
185 #endif
186 			addarg(USER_TYPE, *argv);
187 		}
188 	}
189 	wtmp();
190 	exit(0);
191 }
192 
193 /*
194  * wtmp --
195  *	read through the wtmp file
196  */
197 void
198 wtmp(void)
199 {
200 	struct utmp	*bp;			/* current structure */
201 	struct stat	stb;			/* stat of file for size */
202 	long	bl;
203 	int	bytes, wfd;
204 	char ct[80];
205 	struct tm *tm;
206 	time_t	t;
207 
208 	LIST_INIT(&ttylist);
209 
210 	if ((wfd = open(file, O_RDONLY, 0)) < 0 || fstat(wfd, &stb) == -1)
211 		err(1, "%s", file);
212 	bl = (stb.st_size + sizeof(buf) - 1) / sizeof(buf);
213 
214 	(void)time(&t);
215 	buf[0].ut_time = _time_to_int(t);
216 	(void)signal(SIGINT, onintr);
217 	(void)signal(SIGQUIT, onintr);
218 
219 	while (--bl >= 0) {
220 		if (lseek(wfd, (off_t)(bl * sizeof(buf)), L_SET) == -1 ||
221 		    (bytes = read(wfd, buf, sizeof(buf))) == -1)
222 			err(1, "%s", file);
223 		for (bp = &buf[bytes / sizeof(buf[0]) - 1]; bp >= buf; --bp)
224 			doentry(bp);
225 	}
226 	t = _int_to_time(buf[0].ut_time);
227 	tm = localtime(&t);
228 	(void) strftime(ct, sizeof(ct), "\nwtmp begins %+\n", tm);
229 	printf("%s", ct);
230 }
231 
232 /*
233  * doentry --
234  *	process a single wtmp entry
235  */
236 void
237 doentry(struct utmp *bp)
238 {
239 	struct ttytab	*tt, *ttx;		/* ttylist entry */
240 
241 	/*
242 	 * if the terminal line is '~', the machine stopped.
243 	 * see utmp(5) for more info.
244 	 */
245 	if (bp->ut_line[0] == '~' && !bp->ut_line[1]) {
246 		/* everybody just logged out */
247 		for (tt = LIST_FIRST(&ttylist); tt;) {
248 			LIST_REMOVE(tt, list);
249 			ttx = tt;
250 			tt = LIST_NEXT(tt, list);
251 			free(ttx);
252 		}
253 		currentout = -bp->ut_time;
254 		crmsg = strncmp(bp->ut_name, "shutdown", UT_NAMESIZE) ?
255 		    "crash" : "shutdown";
256 		/*
257 		 * if we're in snapshot mode, we want to exit if this
258 		 * shutdown/reboot appears while we we are tracking the
259 		 * active range
260 		 */
261 		if (snaptime && snapfound)
262 			exit(0);
263 		/*
264 		 * don't print shutdown/reboot entries unless flagged for
265 		 */
266 		if (!snaptime && want(bp))
267 			printentry(bp, NULL);
268 		return;
269 	}
270 	/*
271 	 * if the line is '{' or '|', date got set; see
272 	 * utmp(5) for more info.
273 	 */
274 	if ((bp->ut_line[0] == '{' || bp->ut_line[0] == '|') &&
275 	    !bp->ut_line[1]) {
276 		if (want(bp) && !snaptime)
277 			printentry(bp, NULL);
278 		return;
279 	}
280 	/* find associated tty */
281 	LIST_FOREACH(tt, &ttylist, list)
282 	    if (!strncmp(tt->tty, bp->ut_line, UT_LINESIZE))
283 		    break;
284 
285 	if (tt == NULL) {
286 		/* add new one */
287 		tt = malloc(sizeof(struct ttytab));
288 		if (tt == NULL)
289 			errx(1, "malloc failure");
290 		tt->logout = currentout;
291 		strncpy(tt->tty, bp->ut_line, UT_LINESIZE);
292 		LIST_INSERT_HEAD(&ttylist, tt, list);
293 	}
294 
295 	/*
296 	 * print record if not in snapshot mode and wanted
297 	 * or in snapshot mode and in snapshot range
298 	 */
299 	if (bp->ut_name[0] && (want(bp) || (bp->ut_time < snaptime &&
300 	    (tt->logout > snaptime || tt->logout < 1)))) {
301 		snapfound = 1;
302 		/*
303 		 * when uucp and ftp log in over a network, the entry in
304 		 * the utmp file is the name plus their process id.  See
305 		 * etc/ftpd.c and usr.bin/uucp/uucpd.c for more information.
306 		 */
307 		if (!strncmp(bp->ut_line, "ftp", sizeof("ftp") - 1))
308 			bp->ut_line[3] = '\0';
309 		else if (!strncmp(bp->ut_line, "uucp", sizeof("uucp") - 1))
310 			bp->ut_line[4] = '\0';
311 		printentry(bp, tt);
312 	}
313 	tt->logout = bp->ut_time;
314 }
315 
316 /*
317  * printentry --
318  *	output an entry
319  *
320  * If `tt' is non-NULL, use it and `crmsg' to print the logout time or
321  * logout type (crash/shutdown) as appropriate.
322  */
323 void
324 printentry(struct utmp *bp, struct ttytab *tt)
325 {
326 	char ct[80];
327 	struct tm *tm;
328 	time_t	delta;				/* time difference */
329 	time_t	t;
330 
331 	if (maxrec != -1 && !maxrec--)
332 		exit(0);
333 	t = _int_to_time(bp->ut_time);
334 	tm = localtime(&t);
335 	(void) strftime(ct, sizeof(ct), d_first ?
336 	    (yflag ? "%a %e %b %Y %R" : "%a %e %b %R") :
337 	    (yflag ? "%a %b %e %Y %R" : "%a %b %e %R"), tm);
338 	printf("%-*.*s %-*.*s %-*.*s %s%c",
339 	    UT_NAMESIZE, UT_NAMESIZE, bp->ut_name,
340 	    UT_LINESIZE, UT_LINESIZE, bp->ut_line,
341 	    UT_HOSTSIZE, UT_HOSTSIZE, bp->ut_host,
342 	    ct, tt == NULL ? '\n' : ' ');
343 	if (tt == NULL)
344 		return;
345 	if (!tt->logout) {
346 		puts("  still logged in");
347 		return;
348 	}
349 	if (tt->logout < 0) {
350 		tt->logout = -tt->logout;
351 		printf("- %s", crmsg);
352 	} else {
353 		tm = localtime(&tt->logout);
354 		(void) strftime(ct, sizeof(ct), "%R", tm);
355 		printf("- %s", ct);
356 	}
357 	delta = tt->logout - bp->ut_time;
358 	if (sflag) {
359 		printf("  (%8ld)\n", (long)delta);
360 	} else {
361 		tm = gmtime(&delta);
362 		(void) strftime(ct, sizeof(ct), width >= 8 ? "%T" : "%R", tm);
363 		if (delta < 86400)
364 			printf("  (%s)\n", ct);
365 		else
366 			printf(" (%ld+%s)\n", (long)delta / 86400, ct);
367 	}
368 }
369 
370 /*
371  * want --
372  *	see if want this entry
373  */
374 int
375 want(struct utmp *bp)
376 {
377 	ARG *step;
378 
379 	if (snaptime)
380 		return (NO);
381 
382 	if (!arglist)
383 		return (YES);
384 
385 	for (step = arglist; step; step = step->next)
386 		switch(step->type) {
387 		case HOST_TYPE:
388 			if (!strncasecmp(step->name, bp->ut_host, UT_HOSTSIZE))
389 				return (YES);
390 			break;
391 		case TTY_TYPE:
392 			if (!strncmp(step->name, bp->ut_line, UT_LINESIZE))
393 				return (YES);
394 			break;
395 		case USER_TYPE:
396 			if (!strncmp(step->name, bp->ut_name, UT_NAMESIZE))
397 				return (YES);
398 			break;
399 		}
400 	return (NO);
401 }
402 
403 /*
404  * addarg --
405  *	add an entry to a linked list of arguments
406  */
407 void
408 addarg(int type, char *arg)
409 {
410 	ARG *cur;
411 
412 	if ((cur = malloc(sizeof(ARG))) == NULL)
413 		errx(1, "malloc failure");
414 	cur->next = arglist;
415 	cur->type = type;
416 	cur->name = arg;
417 	arglist = cur;
418 }
419 
420 /*
421  * hostconv --
422  *	convert the hostname to search pattern; if the supplied host name
423  *	has a domain attached that is the same as the current domain, rip
424  *	off the domain suffix since that's what login(1) does.
425  */
426 void
427 hostconv(char *arg)
428 {
429 	static int first = 1;
430 	static char *hostdot, name[MAXHOSTNAMELEN];
431 	char *argdot;
432 
433 	if (!(argdot = strchr(arg, '.')))
434 		return;
435 	if (first) {
436 		first = 0;
437 		if (gethostname(name, sizeof(name)))
438 			err(1, "gethostname");
439 		hostdot = strchr(name, '.');
440 	}
441 	if (hostdot && !strcasecmp(hostdot, argdot))
442 		*argdot = '\0';
443 }
444 
445 /*
446  * ttyconv --
447  *	convert tty to correct name.
448  */
449 char *
450 ttyconv(char *arg)
451 {
452 	char *mval;
453 
454 	/*
455 	 * kludge -- we assume that all tty's end with
456 	 * a two character suffix.
457 	 */
458 	if (strlen(arg) == 2) {
459 		/* either 6 for "ttyxx" or 8 for "console" */
460 		if ((mval = malloc(8)) == NULL)
461 			errx(1, "malloc failure");
462 		if (!strcmp(arg, "co"))
463 			(void)strcpy(mval, "console");
464 		else {
465 			(void)strcpy(mval, "tty");
466 			(void)strcpy(mval + 3, arg);
467 		}
468 		return (mval);
469 	}
470 	if (!strncmp(arg, _PATH_DEV, sizeof(_PATH_DEV) - 1))
471 		return (arg + 5);
472 	return (arg);
473 }
474 
475 /*
476  * dateconv --
477  * 	Convert the snapshot time in command line given in the format
478  * 	[[CC]YY]MMDDhhmm[.SS]] to a time_t.
479  * 	Derived from atime_arg1() in usr.bin/touch/touch.c
480  */
481 time_t
482 dateconv(char *arg)
483 {
484         time_t timet;
485         struct tm *t;
486         int yearset;
487         char *p;
488 
489         /* Start with the current time. */
490         if (time(&timet) < 0)
491                 err(1, "time");
492         if ((t = localtime(&timet)) == NULL)
493                 err(1, "localtime");
494 
495         /* [[CC]YY]MMDDhhmm[.SS] */
496         if ((p = strchr(arg, '.')) == NULL)
497                 t->tm_sec = 0; 		/* Seconds defaults to 0. */
498         else {
499                 if (strlen(p + 1) != 2)
500                         goto terr;
501                 *p++ = '\0';
502                 t->tm_sec = ATOI2(p);
503         }
504 
505         yearset = 0;
506         switch (strlen(arg)) {
507         case 12:                	/* CCYYMMDDhhmm */
508                 t->tm_year = ATOI2(arg);
509                 t->tm_year *= 100;
510                 yearset = 1;
511                 /* FALLTHOUGH */
512         case 10:                	/* YYMMDDhhmm */
513                 if (yearset) {
514                         yearset = ATOI2(arg);
515                         t->tm_year += yearset;
516                 } else {
517                         yearset = ATOI2(arg);
518                         if (yearset < 69)
519                                 t->tm_year = yearset + 2000;
520                         else
521                                 t->tm_year = yearset + 1900;
522                 }
523                 t->tm_year -= 1900;     /* Convert to UNIX time. */
524                 /* FALLTHROUGH */
525         case 8:				/* MMDDhhmm */
526                 t->tm_mon = ATOI2(arg);
527                 --t->tm_mon;    	/* Convert from 01-12 to 00-11 */
528                 t->tm_mday = ATOI2(arg);
529                 t->tm_hour = ATOI2(arg);
530                 t->tm_min = ATOI2(arg);
531                 break;
532         case 4:				/* hhmm */
533                 t->tm_hour = ATOI2(arg);
534                 t->tm_min = ATOI2(arg);
535                 break;
536         default:
537                 goto terr;
538         }
539         t->tm_isdst = -1;       	/* Figure out DST. */
540         timet = mktime(t);
541         if (timet == -1)
542 terr:           errx(1,
543         "out of range or illegal time specification: [[CC]YY]MMDDhhmm[.SS]");
544         return timet;
545 }
546 
547 
548 /*
549  * onintr --
550  *	on interrupt, we inform the user how far we've gotten
551  */
552 void
553 onintr(int signo)
554 {
555 	char ct[80];
556 	struct tm *tm;
557 	time_t t = _int_to_time(buf[0].ut_time);
558 
559 	tm = localtime(&t);
560 	(void) strftime(ct, sizeof(ct),
561 			d_first ? "%a %e %b %R" : "%a %b %e %R",
562 			tm);
563 	printf("\ninterrupted %s\n", ct);
564 	if (signo == SIGINT)
565 		exit(1);
566 	(void)fflush(stdout);			/* fix required for rsh */
567 }
568