summaryrefslogtreecommitdiffstats
path: root/usr.bin/last/last.c
blob: d9877b423bb86e8f6282815067c4d5903be44ba8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
/*
 * Copyright (c) 1987, 1993, 1994
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef lint
static const char copyright[] =
"@(#) Copyright (c) 1987, 1993, 1994\n\
	The Regents of the University of California.  All rights reserved.\n";
#endif /* not lint */

#ifndef lint
static const char sccsid[] = "@(#)last.c	8.2 (Berkeley) 4/2/94";
#endif /* not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include <sys/param.h>
#include <sys/stat.h>

#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <langinfo.h>
#include <locale.h>
#include <paths.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <timeconv.h>
#include <unistd.h>
#include <utmp.h>
#include <sys/queue.h>

#define	NO	0				/* false/no */
#define	YES	1				/* true/yes */
#define	ATOI2(ar)	((ar)[0] - '0') * 10 + ((ar)[1] - '0'); (ar) += 2;

static struct utmp	buf[1024];		/* utmp read buffer */

typedef struct arg {
	char	*name;				/* argument */
#define	HOST_TYPE	-2
#define	TTY_TYPE	-3
#define	USER_TYPE	-4
	int	type;				/* type of arg */
	struct arg	*next;			/* linked list pointer */
} ARG;
ARG	*arglist;				/* head of linked list */

LIST_HEAD(ttylisthead, ttytab) ttylist;

struct ttytab {
	time_t	logout;				/* log out time */
	char	tty[UT_LINESIZE + 1];		/* terminal name */
	LIST_ENTRY(ttytab) list;
};

static const	char *crmsg;			/* cause of last reboot */
static long	currentout,			/* current logout value */
		maxrec;				/* records to display */
static const	char *file = _PATH_WTMP;		/* wtmp file */
static int	sflag = 0;			/* show delta in seconds */
static int	width = 5;			/* show seconds in delta */
static int	yflag;				/* show year */
static int      d_first;
static int	snapfound = 0;			/* found snapshot entry? */
static time_t	snaptime;			/* if != 0, we will only
						 * report users logged in
						 * at this snapshot time
						 */

void	 addarg(int, char *);
time_t	 dateconv(char *);
void	 doentry(struct utmp *);
void	 hostconv(char *);
void	 onintr(int);
void	 printentry(struct utmp *, struct ttytab *);
char	*ttyconv(char *);
int	 want(struct utmp *);
void	 usage(void);
void	 wtmp(void);

void
usage(void)
{
	(void)fprintf(stderr,
"usage: last [-swy] [-d [[CC]YY][MMDD]hhmm[.SS]] [-f file] [-h host]\n"
"            [-n maxrec] [-t tty] [user ...]\n");
	exit(1);
}

int
main(int argc, char *argv[])
{
	int ch;
	char *p;

	(void) setlocale(LC_TIME, "");
	d_first = (*nl_langinfo(D_MD_ORDER) == 'd');

	maxrec = -1;
	snaptime = 0;
	while ((ch = getopt(argc, argv, "0123456789d:f:h:n:st:wy")) != -1)
		switch (ch) {
		case '0': case '1': case '2': case '3': case '4':
		case '5': case '6': case '7': case '8': case '9':
			/*
			 * kludge: last was originally designed to take
			 * a number after a dash.
			 */
			if (maxrec == -1) {
				p = strchr(argv[optind - 1], ch);
				if (p == NULL)
					p = strchr(argv[optind], ch);
				maxrec = atol(p);
				if (!maxrec)
					exit(0);
			}
			break;
		case 'd':
			snaptime = dateconv(optarg);
			break;
		case 'f':
			file = optarg;
			break;
		case 'h':
			hostconv(optarg);
			addarg(HOST_TYPE, optarg);
			break;
		case 'n':
			errno = 0;
			maxrec = strtol(optarg, &p, 10);
			if (p == optarg || *p != '\0' || errno != 0 ||
			    maxrec <= 0)
				errx(1, "%s: bad line count", optarg);
			break;
		case 's':
			sflag++;	/* Show delta as seconds */
			break;
		case 't':
			addarg(TTY_TYPE, ttyconv(optarg));
			break;
		case 'w':
			width = 8;
			break;
		case 'y':
			yflag++;
			break;
		case '?':
		default:
			usage();
		}

	if (sflag && width == 8) usage();

	if (argc) {
		setlinebuf(stdout);
		for (argv += optind; *argv; ++argv) {
#define	COMPATIBILITY
#ifdef	COMPATIBILITY
			/* code to allow "last p5" to work */
			addarg(TTY_TYPE, ttyconv(*argv));
#endif
			addarg(USER_TYPE, *argv);
		}
	}
	wtmp();
	exit(0);
}

/*
 * wtmp --
 *	read through the wtmp file
 */
void
wtmp(void)
{
	struct utmp	*bp;			/* current structure */
	struct stat	stb;			/* stat of file for size */
	long	bl;
	int	bytes, wfd;
	char ct[80];
	struct tm *tm;
	time_t	t;

	LIST_INIT(&ttylist);

	if ((wfd = open(file, O_RDONLY, 0)) < 0 || fstat(wfd, &stb) == -1)
		err(1, "%s", file);
	bl = (stb.st_size + sizeof(buf) - 1) / sizeof(buf);

	(void)time(&t);
	buf[0].ut_time = _time_to_int(t);
	(void)signal(SIGINT, onintr);
	(void)signal(SIGQUIT, onintr);

	while (--bl >= 0) {
		if (lseek(wfd, (off_t)(bl * sizeof(buf)), L_SET) == -1 ||
		    (bytes = read(wfd, buf, sizeof(buf))) == -1)
			err(1, "%s", file);
		for (bp = &buf[bytes / sizeof(buf[0]) - 1]; bp >= buf; --bp)
			doentry(bp);
	}
	t = _int_to_time(buf[0].ut_time);
	tm = localtime(&t);
	(void) strftime(ct, sizeof(ct), "\nwtmp begins %+\n", tm);
	printf("%s", ct);
}

/*
 * doentry --
 *	process a single wtmp entry
 */
void
doentry(struct utmp *bp)
{
	struct ttytab	*tt, *ttx;		/* ttylist entry */

	/*
	 * if the terminal line is '~', the machine stopped.
	 * see utmp(5) for more info.
	 */
	if (bp->ut_line[0] == '~' && !bp->ut_line[1]) {
		/* everybody just logged out */
		for (tt = LIST_FIRST(&ttylist); tt;) {
			LIST_REMOVE(tt, list);
			ttx = tt;
			tt = LIST_NEXT(tt, list);
			free(ttx);
		}
		currentout = -bp->ut_time;
		crmsg = strncmp(bp->ut_name, "shutdown", UT_NAMESIZE) ?
		    "crash" : "shutdown";
		/*
		 * if we're in snapshot mode, we want to exit if this
		 * shutdown/reboot appears while we we are tracking the
		 * active range
		 */
		if (snaptime && snapfound)
			exit(0);
		/*
		 * don't print shutdown/reboot entries unless flagged for
		 */
		if (!snaptime && want(bp))
			printentry(bp, NULL);
		return;
	}
	/*
	 * if the line is '{' or '|', date got set; see
	 * utmp(5) for more info.
	 */
	if ((bp->ut_line[0] == '{' || bp->ut_line[0] == '|') &&
	    !bp->ut_line[1]) {
		if (want(bp) && !snaptime)
			printentry(bp, NULL);
		return;
	}
	/* find associated tty */
	LIST_FOREACH(tt, &ttylist, list)
	    if (!strncmp(tt->tty, bp->ut_line, UT_LINESIZE))
		    break;

	if (tt == NULL) {
		/* add new one */
		tt = malloc(sizeof(struct ttytab));
		if (tt == NULL)
			errx(1, "malloc failure");
		tt->logout = currentout;
		strncpy(tt->tty, bp->ut_line, UT_LINESIZE);
		LIST_INSERT_HEAD(&ttylist, tt, list);
	}

	/*
	 * print record if not in snapshot mode and wanted
	 * or in snapshot mode and in snapshot range
	 */
	if (bp->ut_name[0] && (want(bp) || (bp->ut_time < snaptime &&
	    (tt->logout > snaptime || tt->logout < 1)))) {
		snapfound = 1;
		/*
		 * when uucp and ftp log in over a network, the entry in
		 * the utmp file is the name plus their process id.  See
		 * etc/ftpd.c and usr.bin/uucp/uucpd.c for more information.
		 */
		if (!strncmp(bp->ut_line, "ftp", sizeof("ftp") - 1))
			bp->ut_line[3] = '\0';
		else if (!strncmp(bp->ut_line, "uucp", sizeof("uucp") - 1))
			bp->ut_line[4] = '\0';
		printentry(bp, tt);
	}
	tt->logout = bp->ut_time;
}

/*
 * printentry --
 *	output an entry
 *
 * If `tt' is non-NULL, use it and `crmsg' to print the logout time or
 * logout type (crash/shutdown) as appropriate.
 */
void
printentry(struct utmp *bp, struct ttytab *tt)
{
	char ct[80];
	struct tm *tm;
	time_t	delta;				/* time difference */
	time_t	t;

	if (maxrec != -1 && !maxrec--)
		exit(0);
	t = _int_to_time(bp->ut_time);
	tm = localtime(&t);
	(void) strftime(ct, sizeof(ct), d_first ?
	    (yflag ? "%a %e %b %Y %R" : "%a %e %b %R") :
	    (yflag ? "%a %b %e %Y %R" : "%a %b %e %R"), tm);
	printf("%-*.*s %-*.*s %-*.*s %s%c",
	    UT_NAMESIZE, UT_NAMESIZE, bp->ut_name,
	    UT_LINESIZE, UT_LINESIZE, bp->ut_line,
	    UT_HOSTSIZE, UT_HOSTSIZE, bp->ut_host,
	    ct, tt == NULL ? '\n' : ' ');
	if (tt == NULL)
		return;
	if (!tt->logout) {
		puts("  still logged in");
		return;
	}
	if (tt->logout < 0) {
		tt->logout = -tt->logout;
		printf("- %s", crmsg);
	} else {
		tm = localtime(&tt->logout);
		(void) strftime(ct, sizeof(ct), "%R", tm);
		printf("- %s", ct);
	}
	delta = tt->logout - bp->ut_time;
	if (sflag) {
		printf("  (%8ld)\n", (long)delta);
	} else {
		tm = gmtime(&delta);
		(void) strftime(ct, sizeof(ct), width >= 8 ? "%T" : "%R", tm);
		if (delta < 86400)
			printf("  (%s)\n", ct);
		else
			printf(" (%ld+%s)\n", (long)delta / 86400, ct);
	}
}

/*
 * want --
 *	see if want this entry
 */
int
want(struct utmp *bp)
{
	ARG *step;

	if (snaptime)
		return (NO);

	if (!arglist)
		return (YES);

	for (step = arglist; step; step = step->next)
		switch(step->type) {
		case HOST_TYPE:
			if (!strncasecmp(step->name, bp->ut_host, UT_HOSTSIZE))
				return (YES);
			break;
		case TTY_TYPE:
			if (!strncmp(step->name, bp->ut_line, UT_LINESIZE))
				return (YES);
			break;
		case USER_TYPE:
			if (!strncmp(step->name, bp->ut_name, UT_NAMESIZE))
				return (YES);
			break;
		}
	return (NO);
}

/*
 * addarg --
 *	add an entry to a linked list of arguments
 */
void
addarg(int type, char *arg)
{
	ARG *cur;

	if ((cur = malloc(sizeof(ARG))) == NULL)
		errx(1, "malloc failure");
	cur->next = arglist;
	cur->type = type;
	cur->name = arg;
	arglist = cur;
}

/*
 * hostconv --
 *	convert the hostname to search pattern; if the supplied host name
 *	has a domain attached that is the same as the current domain, rip
 *	off the domain suffix since that's what login(1) does.
 */
void
hostconv(char *arg)
{
	static int first = 1;
	static char *hostdot, name[MAXHOSTNAMELEN];
	char *argdot;

	if (!(argdot = strchr(arg, '.')))
		return;
	if (first) {
		first = 0;
		if (gethostname(name, sizeof(name)))
			err(1, "gethostname");
		hostdot = strchr(name, '.');
	}
	if (hostdot && !strcasecmp(hostdot, argdot))
		*argdot = '\0';
}

/*
 * ttyconv --
 *	convert tty to correct name.
 */
char *
ttyconv(char *arg)
{
	char *mval;

	/*
	 * kludge -- we assume that all tty's end with
	 * a two character suffix.
	 */
	if (strlen(arg) == 2) {
		/* either 6 for "ttyxx" or 8 for "console" */
		if ((mval = malloc(8)) == NULL)
			errx(1, "malloc failure");
		if (!strcmp(arg, "co"))
			(void)strcpy(mval, "console");
		else {
			(void)strcpy(mval, "tty");
			(void)strcpy(mval + 3, arg);
		}
		return (mval);
	}
	if (!strncmp(arg, _PATH_DEV, sizeof(_PATH_DEV) - 1))
		return (arg + 5);
	return (arg);
}

/*
 * dateconv --
 * 	Convert the snapshot time in command line given in the format
 * 	[[CC]YY]MMDDhhmm[.SS]] to a time_t.
 * 	Derived from atime_arg1() in usr.bin/touch/touch.c
 */
time_t
dateconv(char *arg)
{
        time_t timet;
        struct tm *t;
        int yearset;
        char *p;

        /* Start with the current time. */
        if (time(&timet) < 0)
                err(1, "time");
        if ((t = localtime(&timet)) == NULL)
                err(1, "localtime");

        /* [[CC]YY]MMDDhhmm[.SS] */
        if ((p = strchr(arg, '.')) == NULL)
                t->tm_sec = 0; 		/* Seconds defaults to 0. */
        else {
                if (strlen(p + 1) != 2)
                        goto terr;
                *p++ = '\0';
                t->tm_sec = ATOI2(p);
        }

        yearset = 0;
        switch (strlen(arg)) {
        case 12:                	/* CCYYMMDDhhmm */
                t->tm_year = ATOI2(arg);
                t->tm_year *= 100;
                yearset = 1;
                /* FALLTHROUGH */
        case 10:                	/* YYMMDDhhmm */
                if (yearset) {
                        yearset = ATOI2(arg);
                        t->tm_year += yearset;
                } else {
                        yearset = ATOI2(arg);
                        if (yearset < 69)
                                t->tm_year = yearset + 2000;
                        else
                                t->tm_year = yearset + 1900;
                }
                t->tm_year -= 1900;     /* Convert to UNIX time. */
                /* FALLTHROUGH */
        case 8:				/* MMDDhhmm */
                t->tm_mon = ATOI2(arg);
                --t->tm_mon;    	/* Convert from 01-12 to 00-11 */
                t->tm_mday = ATOI2(arg);
                t->tm_hour = ATOI2(arg);
                t->tm_min = ATOI2(arg);
                break;
        case 4:				/* hhmm */
                t->tm_hour = ATOI2(arg);
                t->tm_min = ATOI2(arg);
                break;
        default:
                goto terr;
        }
        t->tm_isdst = -1;       	/* Figure out DST. */
        timet = mktime(t);
        if (timet == -1)
terr:           errx(1,
        "out of range or illegal time specification: [[CC]YY]MMDDhhmm[.SS]");
        return timet;
}


/*
 * onintr --
 *	on interrupt, we inform the user how far we've gotten
 */
void
onintr(int signo)
{
	char ct[80];
	struct tm *tm;
	time_t t = _int_to_time(buf[0].ut_time);

	tm = localtime(&t);
	(void) strftime(ct, sizeof(ct),
			d_first ? "%a %e %b %R" : "%a %b %e %R",
			tm);
	printf("\ninterrupted %s\n", ct);
	if (signo == SIGINT)
		exit(1);
	(void)fflush(stdout);			/* fix required for rsh */
}
OpenPOWER on IntegriCloud