last.c revision 91536 
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: head/usr.bin/last/last.c 91536 2002-03-01 17:37:06Z iedowse $
34 */
35
36#ifndef lint
37static 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
43static 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
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      d_first;
94static time_t	snaptime;			/* if != 0, we will only
95						 * report users logged in
96						 * at this snapshot time
97						 */
98
99void	 addarg __P((int, char *));
100time_t	 dateconv __P((char *));
101void	 doentry __P((struct utmp *));
102void	 hostconv __P((char *));
103void	 onintr __P((int));
104void	 printentry __P((struct utmp *, struct ttytab *));
105char	*ttyconv __P((char *));
106int	 want __P((struct utmp *));
107void	 usage __P((void));
108void	 wtmp __P((void));
109
110void
111usage(void)
112{
113	(void)fprintf(stderr,
114"usage: last [-#] [-d [[CC]YY][MMDD]hhmm[.SS]] [-f file] [-h hostname]\n"
115"\t[-t tty] [-s|w] [user ...]\n");
116	exit(1);
117}
118
119int
120main(argc, argv)
121	int argc;
122	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:w")) != -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 = argv[optind - 1];
142				if (p[0] == '-' && p[1] == ch && !p[2])
143					maxrec = atol(++p);
144				else
145					maxrec = atol(argv[optind] + 1);
146				if (!maxrec)
147					exit(0);
148			}
149			break;
150		case 'd':
151			snaptime = dateconv(optarg);
152			break;
153		case 'f':
154			file = optarg;
155			break;
156		case 'h':
157			hostconv(optarg);
158			addarg(HOST_TYPE, optarg);
159			break;
160		case 's':
161			sflag++;	/* Show delta as seconds */
162			break;
163		case 't':
164			addarg(TTY_TYPE, ttyconv(optarg));
165			break;
166		case 'w':
167			width = 8;
168			break;
169		case '?':
170		default:
171			usage();
172		}
173
174	if (sflag && width == 8) usage();
175
176	if (argc) {
177		setlinebuf(stdout);
178		for (argv += optind; *argv; ++argv) {
179#define	COMPATIBILITY
180#ifdef	COMPATIBILITY
181			/* code to allow "last p5" to work */
182			addarg(TTY_TYPE, ttyconv(*argv));
183#endif
184			addarg(USER_TYPE, *argv);
185		}
186	}
187	wtmp();
188	exit(0);
189}
190
191/*
192 * wtmp --
193 *	read through the wtmp file
194 */
195void
196wtmp()
197{
198	struct utmp	*bp;			/* current structure */
199	struct stat	stb;			/* stat of file for size */
200	long	bl;
201	int	bytes, wfd;
202	char ct[80];
203	struct tm *tm;
204	time_t	t;
205
206	LIST_INIT(&ttylist);
207
208	if ((wfd = open(file, O_RDONLY, 0)) < 0 || fstat(wfd, &stb) == -1)
209		err(1, "%s", file);
210	bl = (stb.st_size + sizeof(buf) - 1) / sizeof(buf);
211
212	(void)time(&t);
213	buf[0].ut_time = _time_to_int(t);
214	(void)signal(SIGINT, onintr);
215	(void)signal(SIGQUIT, onintr);
216
217	while (--bl >= 0) {
218		if (lseek(wfd, (off_t)(bl * sizeof(buf)), L_SET) == -1 ||
219		    (bytes = read(wfd, buf, sizeof(buf))) == -1)
220			err(1, "%s", file);
221		for (bp = &buf[bytes / sizeof(buf[0]) - 1]; bp >= buf; --bp)
222			doentry(bp);
223	}
224	t = _int_to_time(buf[0].ut_time);
225	tm = localtime(&t);
226	(void) strftime(ct, sizeof(ct), "\nwtmp begins %+\n", tm);
227	printf("%s", ct);
228}
229
230/*
231 * doentry --
232 *	process a single wtmp entry
233 */
234void
235doentry(bp)
236	struct utmp *bp;
237{
238	struct ttytab	*tt, *ttx;		/* ttylist entry */
239	int	 snapfound = 0;			/* found snapshot 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			if (maxrec != -1 && !--maxrec)
269				exit(0);
270		}
271		return;
272	}
273	/*
274	 * if the line is '{' or '|', date got set; see
275	 * utmp(5) for more info.
276	 */
277	if ((bp->ut_line[0] == '{' || bp->ut_line[0] == '|') &&
278	    !bp->ut_line[1]) {
279		if (want(bp) && !snaptime) {
280			printentry(bp, NULL);
281			if (maxrec && !--maxrec)
282				exit(0);
283		}
284		return;
285	}
286	/* find associated tty */
287	LIST_FOREACH(tt, &ttylist, list)
288	    if (!strncmp(tt->tty, bp->ut_line, UT_LINESIZE))
289		    break;
290
291	if (tt == NULL) {
292		/* add new one */
293		tt = malloc(sizeof(struct ttytab));
294		if (tt == NULL)
295			err(1, "malloc failure");
296		tt->logout = currentout;
297		strncpy(tt->tty, bp->ut_line, UT_LINESIZE);
298		LIST_INSERT_HEAD(&ttylist, tt, list);
299	}
300
301	/*
302	 * print record if not in snapshot mode and wanted
303	 * or in snapshot mode and in snapshot range
304	 */
305	if (bp->ut_name[0] && (want(bp) || (bp->ut_time < snaptime &&
306	    (tt->logout > snaptime || tt->logout < 1)))) {
307		snapfound = 1;
308		/*
309		 * when uucp and ftp log in over a network, the entry in
310		 * the utmp file is the name plus their process id.  See
311		 * etc/ftpd.c and usr.bin/uucp/uucpd.c for more information.
312		 */
313		if (!strncmp(bp->ut_line, "ftp", sizeof("ftp") - 1))
314			bp->ut_line[3] = '\0';
315		else if (!strncmp(bp->ut_line, "uucp", sizeof("uucp") - 1))
316			bp->ut_line[4] = '\0';
317		printentry(bp, tt);
318		if (maxrec != -1 && !--maxrec)
319			return;
320	}
321	tt->logout = bp->ut_time;
322}
323
324/*
325 * printentry --
326 *	output an entry
327 *
328 * If `tt' is non-NULL, use it and `crmsg' to print the logout time or
329 * logout type (crash/shutdown) as appropriate.
330 */
331void
332printentry(bp, tt)
333	struct utmp *bp;
334	struct ttytab *tt;
335{
336	char ct[80];
337	struct tm *tm;
338	time_t	delta;				/* time difference */
339	time_t	t;
340
341	t = _int_to_time(bp->ut_time);
342	tm = localtime(&t);
343	(void) strftime(ct, sizeof(ct), d_first ? "%a %e %b %R" :
344	     "%a %b %e %R", tm);
345	printf("%-*.*s %-*.*s %-*.*s %s%c",
346	    UT_NAMESIZE, UT_NAMESIZE, bp->ut_name,
347	    UT_LINESIZE, UT_LINESIZE, bp->ut_line,
348	    UT_HOSTSIZE, UT_HOSTSIZE, bp->ut_host,
349	    ct, tt == NULL ? '\n' : ' ');
350	if (tt == NULL)
351		return;
352	if (!tt->logout) {
353		puts("  still logged in");
354		return;
355	}
356	if (tt->logout < 0) {
357		tt->logout = -tt->logout;
358		printf("- %s", crmsg);
359	} else {
360		tm = localtime(&tt->logout);
361		(void) strftime(ct, sizeof(ct), "%R", tm);
362		printf("- %s", ct);
363	}
364	delta = tt->logout - bp->ut_time;
365	if (sflag) {
366		printf("  (%8ld)\n", (long)delta);
367	} else {
368		tm = gmtime(&delta);
369		(void) strftime(ct, sizeof(ct), width >= 8 ? "%T" : "%R", tm);
370		if (delta < 86400)
371			printf("  (%s)\n", ct);
372		else
373			printf(" (%ld+%s)\n", (long)delta / 86400, ct);
374	}
375}
376
377/*
378 * want --
379 *	see if want this entry
380 */
381int
382want(bp)
383	struct utmp *bp;
384{
385	ARG *step;
386
387	if (snaptime)
388		return (NO);
389
390	if (!arglist)
391		return (YES);
392
393	for (step = arglist; step; step = step->next)
394		switch(step->type) {
395		case HOST_TYPE:
396			if (!strncasecmp(step->name, bp->ut_host, UT_HOSTSIZE))
397				return (YES);
398			break;
399		case TTY_TYPE:
400			if (!strncmp(step->name, bp->ut_line, UT_LINESIZE))
401				return (YES);
402			break;
403		case USER_TYPE:
404			if (!strncmp(step->name, bp->ut_name, UT_NAMESIZE))
405				return (YES);
406			break;
407		}
408	return (NO);
409}
410
411/*
412 * addarg --
413 *	add an entry to a linked list of arguments
414 */
415void
416addarg(type, arg)
417	int type;
418	char *arg;
419{
420	ARG *cur;
421
422	if (!(cur = (ARG *)malloc((u_int)sizeof(ARG))))
423		err(1, "malloc failure");
424	cur->next = arglist;
425	cur->type = type;
426	cur->name = arg;
427	arglist = cur;
428}
429
430/*
431 * hostconv --
432 *	convert the hostname to search pattern; if the supplied host name
433 *	has a domain attached that is the same as the current domain, rip
434 *	off the domain suffix since that's what login(1) does.
435 */
436void
437hostconv(arg)
438	char *arg;
439{
440	static int first = 1;
441	static char *hostdot, name[MAXHOSTNAMELEN];
442	char *argdot;
443
444	if (!(argdot = strchr(arg, '.')))
445		return;
446	if (first) {
447		first = 0;
448		if (gethostname(name, sizeof(name)))
449			err(1, "gethostname");
450		hostdot = strchr(name, '.');
451	}
452	if (hostdot && !strcasecmp(hostdot, argdot))
453		*argdot = '\0';
454}
455
456/*
457 * ttyconv --
458 *	convert tty to correct name.
459 */
460char *
461ttyconv(arg)
462	char *arg;
463{
464	char *mval;
465
466	/*
467	 * kludge -- we assume that all tty's end with
468	 * a two character suffix.
469	 */
470	if (strlen(arg) == 2) {
471		/* either 6 for "ttyxx" or 8 for "console" */
472		if (!(mval = malloc((u_int)8)))
473			err(1, "malloc failure");
474		if (!strcmp(arg, "co"))
475			(void)strcpy(mval, "console");
476		else {
477			(void)strcpy(mval, "tty");
478			(void)strcpy(mval + 3, arg);
479		}
480		return (mval);
481	}
482	if (!strncmp(arg, _PATH_DEV, sizeof(_PATH_DEV) - 1))
483		return (arg + 5);
484	return (arg);
485}
486
487/*
488 * dateconv --
489 * 	Convert the snapshot time in command line given in the format
490 * 	[[CC]YY]MMDDhhmm[.SS]] to a time_t.
491 * 	Derived from atime_arg1() in usr.bin/touch/touch.c
492 */
493time_t
494dateconv(arg)
495        char *arg;
496{
497        time_t timet;
498        struct tm *t;
499        int yearset;
500        char *p;
501
502        /* Start with the current time. */
503        if (time(&timet) < 0)
504                err(1, "time");
505        if ((t = localtime(&timet)) == NULL)
506                err(1, "localtime");
507
508        /* [[CC]YY]MMDDhhmm[.SS] */
509        if ((p = strchr(arg, '.')) == NULL)
510                t->tm_sec = 0; 		/* Seconds defaults to 0. */
511        else {
512                if (strlen(p + 1) != 2)
513                        goto terr;
514                *p++ = '\0';
515                t->tm_sec = ATOI2(p);
516        }
517
518        yearset = 0;
519        switch (strlen(arg)) {
520        case 12:                	/* CCYYMMDDhhmm */
521                t->tm_year = ATOI2(arg);
522                t->tm_year *= 100;
523                yearset = 1;
524                /* FALLTHOUGH */
525        case 10:                	/* YYMMDDhhmm */
526                if (yearset) {
527                        yearset = ATOI2(arg);
528                        t->tm_year += yearset;
529                } else {
530                        yearset = ATOI2(arg);
531                        if (yearset < 69)
532                                t->tm_year = yearset + 2000;
533                        else
534                                t->tm_year = yearset + 1900;
535                }
536                t->tm_year -= 1900;     /* Convert to UNIX time. */
537                /* FALLTHROUGH */
538        case 8:				/* MMDDhhmm */
539                t->tm_mon = ATOI2(arg);
540                --t->tm_mon;    	/* Convert from 01-12 to 00-11 */
541                t->tm_mday = ATOI2(arg);
542                t->tm_hour = ATOI2(arg);
543                t->tm_min = ATOI2(arg);
544                break;
545        case 4:				/* hhmm */
546                t->tm_hour = ATOI2(arg);
547                t->tm_min = ATOI2(arg);
548                break;
549        default:
550                goto terr;
551        }
552        t->tm_isdst = -1;       	/* Figure out DST. */
553        timet = mktime(t);
554        if (timet == -1)
555terr:           errx(1,
556        "out of range or illegal time specification: [[CC]YY]MMDDhhmm[.SS]");
557        return timet;
558}
559
560
561/*
562 * onintr --
563 *	on interrupt, we inform the user how far we've gotten
564 */
565void
566onintr(signo)
567	int signo;
568{
569	char ct[80];
570	struct tm *tm;
571	time_t t = _int_to_time(buf[0].ut_time);
572
573	tm = localtime(&t);
574	(void) strftime(ct, sizeof(ct),
575			d_first ? "%a %e %b %R" : "%a %b %e %R",
576			tm);
577	printf("\ninterrupted %s\n", ct);
578	if (signo == SIGINT)
579		exit(1);
580	(void)fflush(stdout);			/* fix required for rsh */
581}
582