last.c revision 99112 
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
35static 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
41static const char sccsid[] = "@(#)last.c	8.2 (Berkeley) 4/2/94";
42#endif /* not lint */
43#include <sys/cdefs.h>
44__FBSDID("$FreeBSD: head/usr.bin/last/last.c 99112 2002-06-30 05:25:07Z obrien $");
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
67static struct utmp	buf[1024];		/* utmp read buffer */
68
69typedef 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;
77ARG	*arglist;				/* head of linked list */
78
79LIST_HEAD(ttylisthead, ttytab) ttylist;
80
81struct ttytab {
82	time_t	logout;				/* log out time */
83	char	tty[UT_LINESIZE + 1];		/* terminal name */
84	LIST_ENTRY(ttytab) list;
85};
86
87static const	char *crmsg;			/* cause of last reboot */
88static long	currentout,			/* current logout value */
89		maxrec;				/* records to display */
90static const	char *file = _PATH_WTMP;		/* wtmp file */
91static int	sflag = 0;			/* show delta in seconds */
92static int	width = 5;			/* show seconds in delta */
93static int	yflag;				/* show year */
94static int      d_first;
95static int	snapfound = 0;			/* found snapshot entry? */
96static time_t	snaptime;			/* if != 0, we will only
97						 * report users logged in
98						 * at this snapshot time
99						 */
100
101void	 addarg(int, char *);
102time_t	 dateconv(char *);
103void	 doentry(struct utmp *);
104void	 hostconv(char *);
105void	 onintr(int);
106void	 printentry(struct utmp *, struct ttytab *);
107char	*ttyconv(char *);
108int	 want(struct utmp *);
109void	 usage(void);
110void	 wtmp(void);
111
112void
113usage(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
121int
122main(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 */
200void
201wtmp()
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 */
239void
240doentry(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 */
327void
328printentry(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 */
380int
381want(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 */
414void
415addarg(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 */
435void
436hostconv(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 */
459char *
460ttyconv(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 */
492time_t
493dateconv(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)
554terr:           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 */
564void
565onintr(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