xref: /freebsd/usr.bin/last/last.c (revision c11e094d96120a2e0e726ed9705ae0ec08db49b6)
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  * $FreeBSD$
34  */
35 
36 #ifndef lint
37 static const char copyright[] =
38 "@(#) Copyright (c) 1987, 1993, 1994\n\
39 	The Regents of the University of California.  All rights reserved.\n";
40 #endif /* not lint */
41 
42 #ifndef lint
43 static const char sccsid[] = "@(#)last.c	8.2 (Berkeley) 4/2/94";
44 #endif /* not lint */
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(argc, argv)
123 	int argc;
124 	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: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 = argv[optind - 1];
144 				if (p[0] == '-' && p[1] == ch && !p[2])
145 					maxrec = atol(++p);
146 				else
147 					maxrec = atol(argv[optind] + 1);
148 				if (!maxrec)
149 					exit(0);
150 			}
151 			break;
152 		case 'd':
153 			snaptime = dateconv(optarg);
154 			break;
155 		case 'f':
156 			file = optarg;
157 			break;
158 		case 'h':
159 			hostconv(optarg);
160 			addarg(HOST_TYPE, optarg);
161 			break;
162 		case 's':
163 			sflag++;	/* Show delta as seconds */
164 			break;
165 		case 't':
166 			addarg(TTY_TYPE, ttyconv(optarg));
167 			break;
168 		case 'w':
169 			width = 8;
170 			break;
171 		case 'y':
172 			yflag++;
173 			break;
174 		case '?':
175 		default:
176 			usage();
177 		}
178 
179 	if (sflag && width == 8) usage();
180 
181 	if (argc) {
182 		setlinebuf(stdout);
183 		for (argv += optind; *argv; ++argv) {
184 #define	COMPATIBILITY
185 #ifdef	COMPATIBILITY
186 			/* code to allow "last p5" to work */
187 			addarg(TTY_TYPE, ttyconv(*argv));
188 #endif
189 			addarg(USER_TYPE, *argv);
190 		}
191 	}
192 	wtmp();
193 	exit(0);
194 }
195 
196 /*
197  * wtmp --
198  *	read through the wtmp file
199  */
200 void
201 wtmp()
202 {
203 	struct utmp	*bp;			/* current structure */
204 	struct stat	stb;			/* stat of file for size */
205 	long	bl;
206 	int	bytes, wfd;
207 	char ct[80];
208 	struct tm *tm;
209 	time_t	t;
210 
211 	LIST_INIT(&ttylist);
212 
213 	if ((wfd = open(file, O_RDONLY, 0)) < 0 || fstat(wfd, &stb) == -1)
214 		err(1, "%s", file);
215 	bl = (stb.st_size + sizeof(buf) - 1) / sizeof(buf);
216 
217 	(void)time(&t);
218 	buf[0].ut_time = _time_to_int(t);
219 	(void)signal(SIGINT, onintr);
220 	(void)signal(SIGQUIT, onintr);
221 
222 	while (--bl >= 0) {
223 		if (lseek(wfd, (off_t)(bl * sizeof(buf)), L_SET) == -1 ||
224 		    (bytes = read(wfd, buf, sizeof(buf))) == -1)
225 			err(1, "%s", file);
226 		for (bp = &buf[bytes / sizeof(buf[0]) - 1]; bp >= buf; --bp)
227 			doentry(bp);
228 	}
229 	t = _int_to_time(buf[0].ut_time);
230 	tm = localtime(&t);
231 	(void) strftime(ct, sizeof(ct), "\nwtmp begins %+\n", tm);
232 	printf("%s", ct);
233 }
234 
235 /*
236  * doentry --
237  *	process a single wtmp entry
238  */
239 void
240 doentry(bp)
241 	struct utmp *bp;
242 {
243 	struct ttytab	*tt, *ttx;		/* ttylist entry */
244 
245 	/*
246 	 * if the terminal line is '~', the machine stopped.
247 	 * see utmp(5) for more info.
248 	 */
249 	if (bp->ut_line[0] == '~' && !bp->ut_line[1]) {
250 		/* everybody just logged out */
251 		for (tt = LIST_FIRST(&ttylist); tt;) {
252 			LIST_REMOVE(tt, list);
253 			ttx = tt;
254 			tt = LIST_NEXT(tt, list);
255 			free(ttx);
256 		}
257 		currentout = -bp->ut_time;
258 		crmsg = strncmp(bp->ut_name, "shutdown", UT_NAMESIZE) ?
259 		    "crash" : "shutdown";
260 		/*
261 		 * if we're in snapshot mode, we want to exit if this
262 		 * shutdown/reboot appears while we we are tracking the
263 		 * active range
264 		 */
265 		if (snaptime && snapfound)
266 			exit(0);
267 		/*
268 		 * don't print shutdown/reboot entries unless flagged for
269 		 */
270 		if (!snaptime && want(bp))
271 			printentry(bp, NULL);
272 		return;
273 	}
274 	/*
275 	 * if the line is '{' or '|', date got set; see
276 	 * utmp(5) for more info.
277 	 */
278 	if ((bp->ut_line[0] == '{' || bp->ut_line[0] == '|') &&
279 	    !bp->ut_line[1]) {
280 		if (want(bp) && !snaptime)
281 			printentry(bp, NULL);
282 		return;
283 	}
284 	/* find associated tty */
285 	LIST_FOREACH(tt, &ttylist, list)
286 	    if (!strncmp(tt->tty, bp->ut_line, UT_LINESIZE))
287 		    break;
288 
289 	if (tt == NULL) {
290 		/* add new one */
291 		tt = malloc(sizeof(struct ttytab));
292 		if (tt == NULL)
293 			errx(1, "malloc failure");
294 		tt->logout = currentout;
295 		strncpy(tt->tty, bp->ut_line, UT_LINESIZE);
296 		LIST_INSERT_HEAD(&ttylist, tt, list);
297 	}
298 
299 	/*
300 	 * print record if not in snapshot mode and wanted
301 	 * or in snapshot mode and in snapshot range
302 	 */
303 	if (bp->ut_name[0] && (want(bp) || (bp->ut_time < snaptime &&
304 	    (tt->logout > snaptime || tt->logout < 1)))) {
305 		snapfound = 1;
306 		/*
307 		 * when uucp and ftp log in over a network, the entry in
308 		 * the utmp file is the name plus their process id.  See
309 		 * etc/ftpd.c and usr.bin/uucp/uucpd.c for more information.
310 		 */
311 		if (!strncmp(bp->ut_line, "ftp", sizeof("ftp") - 1))
312 			bp->ut_line[3] = '\0';
313 		else if (!strncmp(bp->ut_line, "uucp", sizeof("uucp") - 1))
314 			bp->ut_line[4] = '\0';
315 		printentry(bp, tt);
316 	}
317 	tt->logout = bp->ut_time;
318 }
319 
320 /*
321  * printentry --
322  *	output an entry
323  *
324  * If `tt' is non-NULL, use it and `crmsg' to print the logout time or
325  * logout type (crash/shutdown) as appropriate.
326  */
327 void
328 printentry(bp, tt)
329 	struct utmp *bp;
330 	struct ttytab *tt;
331 {
332 	char ct[80];
333 	struct tm *tm;
334 	time_t	delta;				/* time difference */
335 	time_t	t;
336 
337 	if (maxrec != -1 && !maxrec--)
338 		exit(0);
339 	t = _int_to_time(bp->ut_time);
340 	tm = localtime(&t);
341 	(void) strftime(ct, sizeof(ct), d_first ?
342 	    (yflag ? "%a %e %b %Y %R" : "%a %e %b %R") :
343 	    (yflag ? "%a %b %e %Y %R" : "%a %b %e %R"), tm);
344 	printf("%-*.*s %-*.*s %-*.*s %s%c",
345 	    UT_NAMESIZE, UT_NAMESIZE, bp->ut_name,
346 	    UT_LINESIZE, UT_LINESIZE, bp->ut_line,
347 	    UT_HOSTSIZE, UT_HOSTSIZE, bp->ut_host,
348 	    ct, tt == NULL ? '\n' : ' ');
349 	if (tt == NULL)
350 		return;
351 	if (!tt->logout) {
352 		puts("  still logged in");
353 		return;
354 	}
355 	if (tt->logout < 0) {
356 		tt->logout = -tt->logout;
357 		printf("- %s", crmsg);
358 	} else {
359 		tm = localtime(&tt->logout);
360 		(void) strftime(ct, sizeof(ct), "%R", tm);
361 		printf("- %s", ct);
362 	}
363 	delta = tt->logout - bp->ut_time;
364 	if (sflag) {
365 		printf("  (%8ld)\n", (long)delta);
366 	} else {
367 		tm = gmtime(&delta);
368 		(void) strftime(ct, sizeof(ct), width >= 8 ? "%T" : "%R", tm);
369 		if (delta < 86400)
370 			printf("  (%s)\n", ct);
371 		else
372 			printf(" (%ld+%s)\n", (long)delta / 86400, ct);
373 	}
374 }
375 
376 /*
377  * want --
378  *	see if want this entry
379  */
380 int
381 want(bp)
382 	struct utmp *bp;
383 {
384 	ARG *step;
385 
386 	if (snaptime)
387 		return (NO);
388 
389 	if (!arglist)
390 		return (YES);
391 
392 	for (step = arglist; step; step = step->next)
393 		switch(step->type) {
394 		case HOST_TYPE:
395 			if (!strncasecmp(step->name, bp->ut_host, UT_HOSTSIZE))
396 				return (YES);
397 			break;
398 		case TTY_TYPE:
399 			if (!strncmp(step->name, bp->ut_line, UT_LINESIZE))
400 				return (YES);
401 			break;
402 		case USER_TYPE:
403 			if (!strncmp(step->name, bp->ut_name, UT_NAMESIZE))
404 				return (YES);
405 			break;
406 		}
407 	return (NO);
408 }
409 
410 /*
411  * addarg --
412  *	add an entry to a linked list of arguments
413  */
414 void
415 addarg(type, arg)
416 	int type;
417 	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(arg)
437 	char *arg;
438 {
439 	static int first = 1;
440 	static char *hostdot, name[MAXHOSTNAMELEN];
441 	char *argdot;
442 
443 	if (!(argdot = strchr(arg, '.')))
444 		return;
445 	if (first) {
446 		first = 0;
447 		if (gethostname(name, sizeof(name)))
448 			err(1, "gethostname");
449 		hostdot = strchr(name, '.');
450 	}
451 	if (hostdot && !strcasecmp(hostdot, argdot))
452 		*argdot = '\0';
453 }
454 
455 /*
456  * ttyconv --
457  *	convert tty to correct name.
458  */
459 char *
460 ttyconv(arg)
461 	char *arg;
462 {
463 	char *mval;
464 
465 	/*
466 	 * kludge -- we assume that all tty's end with
467 	 * a two character suffix.
468 	 */
469 	if (strlen(arg) == 2) {
470 		/* either 6 for "ttyxx" or 8 for "console" */
471 		if ((mval = malloc(8)) == NULL)
472 			errx(1, "malloc failure");
473 		if (!strcmp(arg, "co"))
474 			(void)strcpy(mval, "console");
475 		else {
476 			(void)strcpy(mval, "tty");
477 			(void)strcpy(mval + 3, arg);
478 		}
479 		return (mval);
480 	}
481 	if (!strncmp(arg, _PATH_DEV, sizeof(_PATH_DEV) - 1))
482 		return (arg + 5);
483 	return (arg);
484 }
485 
486 /*
487  * dateconv --
488  * 	Convert the snapshot time in command line given in the format
489  * 	[[CC]YY]MMDDhhmm[.SS]] to a time_t.
490  * 	Derived from atime_arg1() in usr.bin/touch/touch.c
491  */
492 time_t
493 dateconv(arg)
494         char *arg;
495 {
496         time_t timet;
497         struct tm *t;
498         int yearset;
499         char *p;
500 
501         /* Start with the current time. */
502         if (time(&timet) < 0)
503                 err(1, "time");
504         if ((t = localtime(&timet)) == NULL)
505                 err(1, "localtime");
506 
507         /* [[CC]YY]MMDDhhmm[.SS] */
508         if ((p = strchr(arg, '.')) == NULL)
509                 t->tm_sec = 0; 		/* Seconds defaults to 0. */
510         else {
511                 if (strlen(p + 1) != 2)
512                         goto terr;
513                 *p++ = '\0';
514                 t->tm_sec = ATOI2(p);
515         }
516 
517         yearset = 0;
518         switch (strlen(arg)) {
519         case 12:                	/* CCYYMMDDhhmm */
520                 t->tm_year = ATOI2(arg);
521                 t->tm_year *= 100;
522                 yearset = 1;
523                 /* FALLTHOUGH */
524         case 10:                	/* YYMMDDhhmm */
525                 if (yearset) {
526                         yearset = ATOI2(arg);
527                         t->tm_year += yearset;
528                 } else {
529                         yearset = ATOI2(arg);
530                         if (yearset < 69)
531                                 t->tm_year = yearset + 2000;
532                         else
533                                 t->tm_year = yearset + 1900;
534                 }
535                 t->tm_year -= 1900;     /* Convert to UNIX time. */
536                 /* FALLTHROUGH */
537         case 8:				/* MMDDhhmm */
538                 t->tm_mon = ATOI2(arg);
539                 --t->tm_mon;    	/* Convert from 01-12 to 00-11 */
540                 t->tm_mday = ATOI2(arg);
541                 t->tm_hour = ATOI2(arg);
542                 t->tm_min = ATOI2(arg);
543                 break;
544         case 4:				/* hhmm */
545                 t->tm_hour = ATOI2(arg);
546                 t->tm_min = ATOI2(arg);
547                 break;
548         default:
549                 goto terr;
550         }
551         t->tm_isdst = -1;       	/* Figure out DST. */
552         timet = mktime(t);
553         if (timet == -1)
554 terr:           errx(1,
555         "out of range or illegal time specification: [[CC]YY]MMDDhhmm[.SS]");
556         return timet;
557 }
558 
559 
560 /*
561  * onintr --
562  *	on interrupt, we inform the user how far we've gotten
563  */
564 void
565 onintr(signo)
566 	int signo;
567 {
568 	char ct[80];
569 	struct tm *tm;
570 	time_t t = _int_to_time(buf[0].ut_time);
571 
572 	tm = localtime(&t);
573 	(void) strftime(ct, sizeof(ct),
574 			d_first ? "%a %e %b %R" : "%a %b %e %R",
575 			tm);
576 	printf("\ninterrupted %s\n", ct);
577 	if (signo == SIGINT)
578 		exit(1);
579 	(void)fflush(stdout);			/* fix required for rsh */
580 }
581