last.c revision 91538 
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 91538 2002-03-01 19:46:20Z 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 int	snapfound = 0;			/* found snapshot entry? */
95static time_t	snaptime;			/* if != 0, we will only
96						 * report users logged in
97						 * at this snapshot time
98						 */
99
100void	 addarg __P((int, char *));
101time_t	 dateconv __P((char *));
102void	 doentry __P((struct utmp *));
103void	 hostconv __P((char *));
104void	 onintr __P((int));
105void	 printentry __P((struct utmp *, struct ttytab *));
106char	*ttyconv __P((char *));
107int	 want __P((struct utmp *));
108void	 usage __P((void));
109void	 wtmp __P((void));
110
111void
112usage(void)
113{
114	(void)fprintf(stderr,
115"usage: last [-#] [-d [[CC]YY][MMDD]hhmm[.SS]] [-f file] [-h hostname]\n"
116"\t[-t tty] [-s|w] [user ...]\n");
117	exit(1);
118}
119
120int
121main(argc, argv)
122	int argc;
123	char *argv[];
124{
125	int ch;
126	char *p;
127
128	(void) setlocale(LC_TIME, "");
129	d_first = (*nl_langinfo(D_MD_ORDER) == 'd');
130
131	maxrec = -1;
132	snaptime = 0;
133	while ((ch = getopt(argc, argv, "0123456789d:f:h:st:w")) != -1)
134		switch (ch) {
135		case '0': case '1': case '2': case '3': case '4':
136		case '5': case '6': case '7': case '8': case '9':
137			/*
138			 * kludge: last was originally designed to take
139			 * a number after a dash.
140			 */
141			if (maxrec == -1) {
142				p = argv[optind - 1];
143				if (p[0] == '-' && p[1] == ch && !p[2])
144					maxrec = atol(++p);
145				else
146					maxrec = atol(argv[optind] + 1);
147				if (!maxrec)
148					exit(0);
149			}
150			break;
151		case 'd':
152			snaptime = dateconv(optarg);
153			break;
154		case 'f':
155			file = optarg;
156			break;
157		case 'h':
158			hostconv(optarg);
159			addarg(HOST_TYPE, optarg);
160			break;
161		case 's':
162			sflag++;	/* Show delta as seconds */
163			break;
164		case 't':
165			addarg(TTY_TYPE, ttyconv(optarg));
166			break;
167		case 'w':
168			width = 8;
169			break;
170		case '?':
171		default:
172			usage();
173		}
174
175	if (sflag && width == 8) usage();
176
177	if (argc) {
178		setlinebuf(stdout);
179		for (argv += optind; *argv; ++argv) {
180#define	COMPATIBILITY
181#ifdef	COMPATIBILITY
182			/* code to allow "last p5" to work */
183			addarg(TTY_TYPE, ttyconv(*argv));
184#endif
185			addarg(USER_TYPE, *argv);
186		}
187	}
188	wtmp();
189	exit(0);
190}
191
192/*
193 * wtmp --
194 *	read through the wtmp file
195 */
196void
197wtmp()
198{
199	struct utmp	*bp;			/* current structure */
200	struct stat	stb;			/* stat of file for size */
201	long	bl;
202	int	bytes, wfd;
203	char ct[80];
204	struct tm *tm;
205	time_t	t;
206
207	LIST_INIT(&ttylist);
208
209	if ((wfd = open(file, O_RDONLY, 0)) < 0 || fstat(wfd, &stb) == -1)
210		err(1, "%s", file);
211	bl = (stb.st_size + sizeof(buf) - 1) / sizeof(buf);
212
213	(void)time(&t);
214	buf[0].ut_time = _time_to_int(t);
215	(void)signal(SIGINT, onintr);
216	(void)signal(SIGQUIT, onintr);
217
218	while (--bl >= 0) {
219		if (lseek(wfd, (off_t)(bl * sizeof(buf)), L_SET) == -1 ||
220		    (bytes = read(wfd, buf, sizeof(buf))) == -1)
221			err(1, "%s", file);
222		for (bp = &buf[bytes / sizeof(buf[0]) - 1]; bp >= buf; --bp)
223			doentry(bp);
224	}
225	t = _int_to_time(buf[0].ut_time);
226	tm = localtime(&t);
227	(void) strftime(ct, sizeof(ct), "\nwtmp begins %+\n", tm);
228	printf("%s", ct);
229}
230
231/*
232 * doentry --
233 *	process a single wtmp entry
234 */
235void
236doentry(bp)
237	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			err(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 */
323void
324printentry(bp, tt)
325	struct utmp *bp;
326	struct ttytab *tt;
327{
328	char ct[80];
329	struct tm *tm;
330	time_t	delta;				/* time difference */
331	time_t	t;
332
333	if (maxrec != -1 && !maxrec--)
334		exit(0);
335	t = _int_to_time(bp->ut_time);
336	tm = localtime(&t);
337	(void) strftime(ct, sizeof(ct), d_first ? "%a %e %b %R" :
338	     "%a %b %e %R", tm);
339	printf("%-*.*s %-*.*s %-*.*s %s%c",
340	    UT_NAMESIZE, UT_NAMESIZE, bp->ut_name,
341	    UT_LINESIZE, UT_LINESIZE, bp->ut_line,
342	    UT_HOSTSIZE, UT_HOSTSIZE, bp->ut_host,
343	    ct, tt == NULL ? '\n' : ' ');
344	if (tt == NULL)
345		return;
346	if (!tt->logout) {
347		puts("  still logged in");
348		return;
349	}
350	if (tt->logout < 0) {
351		tt->logout = -tt->logout;
352		printf("- %s", crmsg);
353	} else {
354		tm = localtime(&tt->logout);
355		(void) strftime(ct, sizeof(ct), "%R", tm);
356		printf("- %s", ct);
357	}
358	delta = tt->logout - bp->ut_time;
359	if (sflag) {
360		printf("  (%8ld)\n", (long)delta);
361	} else {
362		tm = gmtime(&delta);
363		(void) strftime(ct, sizeof(ct), width >= 8 ? "%T" : "%R", tm);
364		if (delta < 86400)
365			printf("  (%s)\n", ct);
366		else
367			printf(" (%ld+%s)\n", (long)delta / 86400, ct);
368	}
369}
370
371/*
372 * want --
373 *	see if want this entry
374 */
375int
376want(bp)
377	struct utmp *bp;
378{
379	ARG *step;
380
381	if (snaptime)
382		return (NO);
383
384	if (!arglist)
385		return (YES);
386
387	for (step = arglist; step; step = step->next)
388		switch(step->type) {
389		case HOST_TYPE:
390			if (!strncasecmp(step->name, bp->ut_host, UT_HOSTSIZE))
391				return (YES);
392			break;
393		case TTY_TYPE:
394			if (!strncmp(step->name, bp->ut_line, UT_LINESIZE))
395				return (YES);
396			break;
397		case USER_TYPE:
398			if (!strncmp(step->name, bp->ut_name, UT_NAMESIZE))
399				return (YES);
400			break;
401		}
402	return (NO);
403}
404
405/*
406 * addarg --
407 *	add an entry to a linked list of arguments
408 */
409void
410addarg(type, arg)
411	int type;
412	char *arg;
413{
414	ARG *cur;
415
416	if (!(cur = (ARG *)malloc((u_int)sizeof(ARG))))
417		err(1, "malloc failure");
418	cur->next = arglist;
419	cur->type = type;
420	cur->name = arg;
421	arglist = cur;
422}
423
424/*
425 * hostconv --
426 *	convert the hostname to search pattern; if the supplied host name
427 *	has a domain attached that is the same as the current domain, rip
428 *	off the domain suffix since that's what login(1) does.
429 */
430void
431hostconv(arg)
432	char *arg;
433{
434	static int first = 1;
435	static char *hostdot, name[MAXHOSTNAMELEN];
436	char *argdot;
437
438	if (!(argdot = strchr(arg, '.')))
439		return;
440	if (first) {
441		first = 0;
442		if (gethostname(name, sizeof(name)))
443			err(1, "gethostname");
444		hostdot = strchr(name, '.');
445	}
446	if (hostdot && !strcasecmp(hostdot, argdot))
447		*argdot = '\0';
448}
449
450/*
451 * ttyconv --
452 *	convert tty to correct name.
453 */
454char *
455ttyconv(arg)
456	char *arg;
457{
458	char *mval;
459
460	/*
461	 * kludge -- we assume that all tty's end with
462	 * a two character suffix.
463	 */
464	if (strlen(arg) == 2) {
465		/* either 6 for "ttyxx" or 8 for "console" */
466		if (!(mval = malloc((u_int)8)))
467			err(1, "malloc failure");
468		if (!strcmp(arg, "co"))
469			(void)strcpy(mval, "console");
470		else {
471			(void)strcpy(mval, "tty");
472			(void)strcpy(mval + 3, arg);
473		}
474		return (mval);
475	}
476	if (!strncmp(arg, _PATH_DEV, sizeof(_PATH_DEV) - 1))
477		return (arg + 5);
478	return (arg);
479}
480
481/*
482 * dateconv --
483 * 	Convert the snapshot time in command line given in the format
484 * 	[[CC]YY]MMDDhhmm[.SS]] to a time_t.
485 * 	Derived from atime_arg1() in usr.bin/touch/touch.c
486 */
487time_t
488dateconv(arg)
489        char *arg;
490{
491        time_t timet;
492        struct tm *t;
493        int yearset;
494        char *p;
495
496        /* Start with the current time. */
497        if (time(&timet) < 0)
498                err(1, "time");
499        if ((t = localtime(&timet)) == NULL)
500                err(1, "localtime");
501
502        /* [[CC]YY]MMDDhhmm[.SS] */
503        if ((p = strchr(arg, '.')) == NULL)
504                t->tm_sec = 0; 		/* Seconds defaults to 0. */
505        else {
506                if (strlen(p + 1) != 2)
507                        goto terr;
508                *p++ = '\0';
509                t->tm_sec = ATOI2(p);
510        }
511
512        yearset = 0;
513        switch (strlen(arg)) {
514        case 12:                	/* CCYYMMDDhhmm */
515                t->tm_year = ATOI2(arg);
516                t->tm_year *= 100;
517                yearset = 1;
518                /* FALLTHOUGH */
519        case 10:                	/* YYMMDDhhmm */
520                if (yearset) {
521                        yearset = ATOI2(arg);
522                        t->tm_year += yearset;
523                } else {
524                        yearset = ATOI2(arg);
525                        if (yearset < 69)
526                                t->tm_year = yearset + 2000;
527                        else
528                                t->tm_year = yearset + 1900;
529                }
530                t->tm_year -= 1900;     /* Convert to UNIX time. */
531                /* FALLTHROUGH */
532        case 8:				/* MMDDhhmm */
533                t->tm_mon = ATOI2(arg);
534                --t->tm_mon;    	/* Convert from 01-12 to 00-11 */
535                t->tm_mday = ATOI2(arg);
536                t->tm_hour = ATOI2(arg);
537                t->tm_min = ATOI2(arg);
538                break;
539        case 4:				/* hhmm */
540                t->tm_hour = ATOI2(arg);
541                t->tm_min = ATOI2(arg);
542                break;
543        default:
544                goto terr;
545        }
546        t->tm_isdst = -1;       	/* Figure out DST. */
547        timet = mktime(t);
548        if (timet == -1)
549terr:           errx(1,
550        "out of range or illegal time specification: [[CC]YY]MMDDhhmm[.SS]");
551        return timet;
552}
553
554
555/*
556 * onintr --
557 *	on interrupt, we inform the user how far we've gotten
558 */
559void
560onintr(signo)
561	int signo;
562{
563	char ct[80];
564	struct tm *tm;
565	time_t t = _int_to_time(buf[0].ut_time);
566
567	tm = localtime(&t);
568	(void) strftime(ct, sizeof(ct),
569			d_first ? "%a %e %b %R" : "%a %b %e %R",
570			tm);
571	printf("\ninterrupted %s\n", ct);
572	if (signo == SIGINT)
573		exit(1);
574	(void)fflush(stdout);			/* fix required for rsh */
575}
576