last.c revision 118077 
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 118077 2003-07-27 10:53:28Z tjr $");
45
46#include <sys/param.h>
47#include <sys/stat.h>
48
49#include <err.h>
50#include <errno.h>
51#include <fcntl.h>
52#include <langinfo.h>
53#include <locale.h>
54#include <paths.h>
55#include <signal.h>
56#include <stdio.h>
57#include <stdlib.h>
58#include <string.h>
59#include <time.h>
60#include <unistd.h>
61#include <utmp.h>
62#include <sys/queue.h>
63
64#define	NO	0				/* false/no */
65#define	YES	1				/* true/yes */
66#define	ATOI2(ar)	((ar)[0] - '0') * 10 + ((ar)[1] - '0'); (ar) += 2;
67
68static struct utmp	buf[1024];		/* utmp read buffer */
69
70typedef struct arg {
71	char	*name;				/* argument */
72#define	HOST_TYPE	-2
73#define	TTY_TYPE	-3
74#define	USER_TYPE	-4
75	int	type;				/* type of arg */
76	struct arg	*next;			/* linked list pointer */
77} ARG;
78ARG	*arglist;				/* head of linked list */
79
80LIST_HEAD(ttylisthead, ttytab) ttylist;
81
82struct ttytab {
83	time_t	logout;				/* log out time */
84	char	tty[UT_LINESIZE + 1];		/* terminal name */
85	LIST_ENTRY(ttytab) list;
86};
87
88static const	char *crmsg;			/* cause of last reboot */
89static long	currentout,			/* current logout value */
90		maxrec;				/* records to display */
91static const	char *file = _PATH_WTMP;		/* wtmp file */
92static int	sflag = 0;			/* show delta in seconds */
93static int	width = 5;			/* show seconds in delta */
94static int	yflag;				/* show year */
95static int      d_first;
96static int	snapfound = 0;			/* found snapshot entry? */
97static time_t	snaptime;			/* if != 0, we will only
98						 * report users logged in
99						 * at this snapshot time
100						 */
101
102void	 addarg(int, char *);
103time_t	 dateconv(char *);
104void	 doentry(struct utmp *);
105void	 hostconv(char *);
106void	 onintr(int);
107void	 printentry(struct utmp *, struct ttytab *);
108char	*ttyconv(char *);
109int	 want(struct utmp *);
110void	 usage(void);
111void	 wtmp(void);
112
113void
114usage(void)
115{
116	(void)fprintf(stderr,
117"usage: last [-y] [-d [[CC]YY][MMDD]hhmm[.SS]] [-f file] [-h host]\n"
118"\t[-n maxrec] [-t tty] [-s|w] [user ...]\n");
119	exit(1);
120}
121
122int
123main(int argc, 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:n:st:wy")) != -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 = strchr(argv[optind - 1], ch);
143				if (p == NULL)
144					p = strchr(argv[optind], ch);
145				maxrec = atol(p);
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 'n':
161			errno = 0;
162			maxrec = strtol(optarg, &p, 10);
163			if (p == optarg || *p != '\0' || errno != 0 ||
164			    maxrec <= 0)
165				errx(1, "%s: bad line count", optarg);
166			break;
167		case 's':
168			sflag++;	/* Show delta as seconds */
169			break;
170		case 't':
171			addarg(TTY_TYPE, ttyconv(optarg));
172			break;
173		case 'w':
174			width = 8;
175			break;
176		case 'y':
177			yflag++;
178			break;
179		case '?':
180		default:
181			usage();
182		}
183
184	if (sflag && width == 8) usage();
185
186	if (argc) {
187		setlinebuf(stdout);
188		for (argv += optind; *argv; ++argv) {
189#define	COMPATIBILITY
190#ifdef	COMPATIBILITY
191			/* code to allow "last p5" to work */
192			addarg(TTY_TYPE, ttyconv(*argv));
193#endif
194			addarg(USER_TYPE, *argv);
195		}
196	}
197	wtmp();
198	exit(0);
199}
200
201/*
202 * wtmp --
203 *	read through the wtmp file
204 */
205void
206wtmp(void)
207{
208	struct utmp	*bp;			/* current structure */
209	struct stat	stb;			/* stat of file for size */
210	long	bl;
211	int	bytes, wfd;
212	char ct[80];
213	struct tm *tm;
214	time_t	t;
215
216	LIST_INIT(&ttylist);
217
218	if ((wfd = open(file, O_RDONLY, 0)) < 0 || fstat(wfd, &stb) == -1)
219		err(1, "%s", file);
220	bl = (stb.st_size + sizeof(buf) - 1) / sizeof(buf);
221
222	(void)time(&t);
223	buf[0].ut_time = _time_to_int(t);
224	(void)signal(SIGINT, onintr);
225	(void)signal(SIGQUIT, onintr);
226
227	while (--bl >= 0) {
228		if (lseek(wfd, (off_t)(bl * sizeof(buf)), L_SET) == -1 ||
229		    (bytes = read(wfd, buf, sizeof(buf))) == -1)
230			err(1, "%s", file);
231		for (bp = &buf[bytes / sizeof(buf[0]) - 1]; bp >= buf; --bp)
232			doentry(bp);
233	}
234	t = _int_to_time(buf[0].ut_time);
235	tm = localtime(&t);
236	(void) strftime(ct, sizeof(ct), "\nwtmp begins %+\n", tm);
237	printf("%s", ct);
238}
239
240/*
241 * doentry --
242 *	process a single wtmp entry
243 */
244void
245doentry(struct utmp *bp)
246{
247	struct ttytab	*tt, *ttx;		/* ttylist entry */
248
249	/*
250	 * if the terminal line is '~', the machine stopped.
251	 * see utmp(5) for more info.
252	 */
253	if (bp->ut_line[0] == '~' && !bp->ut_line[1]) {
254		/* everybody just logged out */
255		for (tt = LIST_FIRST(&ttylist); tt;) {
256			LIST_REMOVE(tt, list);
257			ttx = tt;
258			tt = LIST_NEXT(tt, list);
259			free(ttx);
260		}
261		currentout = -bp->ut_time;
262		crmsg = strncmp(bp->ut_name, "shutdown", UT_NAMESIZE) ?
263		    "crash" : "shutdown";
264		/*
265		 * if we're in snapshot mode, we want to exit if this
266		 * shutdown/reboot appears while we we are tracking the
267		 * active range
268		 */
269		if (snaptime && snapfound)
270			exit(0);
271		/*
272		 * don't print shutdown/reboot entries unless flagged for
273		 */
274		if (!snaptime && want(bp))
275			printentry(bp, NULL);
276		return;
277	}
278	/*
279	 * if the line is '{' or '|', date got set; see
280	 * utmp(5) for more info.
281	 */
282	if ((bp->ut_line[0] == '{' || bp->ut_line[0] == '|') &&
283	    !bp->ut_line[1]) {
284		if (want(bp) && !snaptime)
285			printentry(bp, NULL);
286		return;
287	}
288	/* find associated tty */
289	LIST_FOREACH(tt, &ttylist, list)
290	    if (!strncmp(tt->tty, bp->ut_line, UT_LINESIZE))
291		    break;
292
293	if (tt == NULL) {
294		/* add new one */
295		tt = malloc(sizeof(struct ttytab));
296		if (tt == NULL)
297			errx(1, "malloc failure");
298		tt->logout = currentout;
299		strncpy(tt->tty, bp->ut_line, UT_LINESIZE);
300		LIST_INSERT_HEAD(&ttylist, tt, list);
301	}
302
303	/*
304	 * print record if not in snapshot mode and wanted
305	 * or in snapshot mode and in snapshot range
306	 */
307	if (bp->ut_name[0] && (want(bp) || (bp->ut_time < snaptime &&
308	    (tt->logout > snaptime || tt->logout < 1)))) {
309		snapfound = 1;
310		/*
311		 * when uucp and ftp log in over a network, the entry in
312		 * the utmp file is the name plus their process id.  See
313		 * etc/ftpd.c and usr.bin/uucp/uucpd.c for more information.
314		 */
315		if (!strncmp(bp->ut_line, "ftp", sizeof("ftp") - 1))
316			bp->ut_line[3] = '\0';
317		else if (!strncmp(bp->ut_line, "uucp", sizeof("uucp") - 1))
318			bp->ut_line[4] = '\0';
319		printentry(bp, tt);
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(struct utmp *bp, struct ttytab *tt)
333{
334	char ct[80];
335	struct tm *tm;
336	time_t	delta;				/* time difference */
337	time_t	t;
338
339	if (maxrec != -1 && !maxrec--)
340		exit(0);
341	t = _int_to_time(bp->ut_time);
342	tm = localtime(&t);
343	(void) strftime(ct, sizeof(ct), d_first ?
344	    (yflag ? "%a %e %b %Y %R" : "%a %e %b %R") :
345	    (yflag ? "%a %b %e %Y %R" : "%a %b %e %R"), tm);
346	printf("%-*.*s %-*.*s %-*.*s %s%c",
347	    UT_NAMESIZE, UT_NAMESIZE, bp->ut_name,
348	    UT_LINESIZE, UT_LINESIZE, bp->ut_line,
349	    UT_HOSTSIZE, UT_HOSTSIZE, bp->ut_host,
350	    ct, tt == NULL ? '\n' : ' ');
351	if (tt == NULL)
352		return;
353	if (!tt->logout) {
354		puts("  still logged in");
355		return;
356	}
357	if (tt->logout < 0) {
358		tt->logout = -tt->logout;
359		printf("- %s", crmsg);
360	} else {
361		tm = localtime(&tt->logout);
362		(void) strftime(ct, sizeof(ct), "%R", tm);
363		printf("- %s", ct);
364	}
365	delta = tt->logout - bp->ut_time;
366	if (sflag) {
367		printf("  (%8ld)\n", (long)delta);
368	} else {
369		tm = gmtime(&delta);
370		(void) strftime(ct, sizeof(ct), width >= 8 ? "%T" : "%R", tm);
371		if (delta < 86400)
372			printf("  (%s)\n", ct);
373		else
374			printf(" (%ld+%s)\n", (long)delta / 86400, ct);
375	}
376}
377
378/*
379 * want --
380 *	see if want this entry
381 */
382int
383want(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(int type, char *arg)
417{
418	ARG *cur;
419
420	if ((cur = malloc(sizeof(ARG))) == NULL)
421		errx(1, "malloc failure");
422	cur->next = arglist;
423	cur->type = type;
424	cur->name = arg;
425	arglist = cur;
426}
427
428/*
429 * hostconv --
430 *	convert the hostname to search pattern; if the supplied host name
431 *	has a domain attached that is the same as the current domain, rip
432 *	off the domain suffix since that's what login(1) does.
433 */
434void
435hostconv(char *arg)
436{
437	static int first = 1;
438	static char *hostdot, name[MAXHOSTNAMELEN];
439	char *argdot;
440
441	if (!(argdot = strchr(arg, '.')))
442		return;
443	if (first) {
444		first = 0;
445		if (gethostname(name, sizeof(name)))
446			err(1, "gethostname");
447		hostdot = strchr(name, '.');
448	}
449	if (hostdot && !strcasecmp(hostdot, argdot))
450		*argdot = '\0';
451}
452
453/*
454 * ttyconv --
455 *	convert tty to correct name.
456 */
457char *
458ttyconv(char *arg)
459{
460	char *mval;
461
462	/*
463	 * kludge -- we assume that all tty's end with
464	 * a two character suffix.
465	 */
466	if (strlen(arg) == 2) {
467		/* either 6 for "ttyxx" or 8 for "console" */
468		if ((mval = malloc(8)) == NULL)
469			errx(1, "malloc failure");
470		if (!strcmp(arg, "co"))
471			(void)strcpy(mval, "console");
472		else {
473			(void)strcpy(mval, "tty");
474			(void)strcpy(mval + 3, arg);
475		}
476		return (mval);
477	}
478	if (!strncmp(arg, _PATH_DEV, sizeof(_PATH_DEV) - 1))
479		return (arg + 5);
480	return (arg);
481}
482
483/*
484 * dateconv --
485 * 	Convert the snapshot time in command line given in the format
486 * 	[[CC]YY]MMDDhhmm[.SS]] to a time_t.
487 * 	Derived from atime_arg1() in usr.bin/touch/touch.c
488 */
489time_t
490dateconv(char *arg)
491{
492        time_t timet;
493        struct tm *t;
494        int yearset;
495        char *p;
496
497        /* Start with the current time. */
498        if (time(&timet) < 0)
499                err(1, "time");
500        if ((t = localtime(&timet)) == NULL)
501                err(1, "localtime");
502
503        /* [[CC]YY]MMDDhhmm[.SS] */
504        if ((p = strchr(arg, '.')) == NULL)
505                t->tm_sec = 0; 		/* Seconds defaults to 0. */
506        else {
507                if (strlen(p + 1) != 2)
508                        goto terr;
509                *p++ = '\0';
510                t->tm_sec = ATOI2(p);
511        }
512
513        yearset = 0;
514        switch (strlen(arg)) {
515        case 12:                	/* CCYYMMDDhhmm */
516                t->tm_year = ATOI2(arg);
517                t->tm_year *= 100;
518                yearset = 1;
519                /* FALLTHOUGH */
520        case 10:                	/* YYMMDDhhmm */
521                if (yearset) {
522                        yearset = ATOI2(arg);
523                        t->tm_year += yearset;
524                } else {
525                        yearset = ATOI2(arg);
526                        if (yearset < 69)
527                                t->tm_year = yearset + 2000;
528                        else
529                                t->tm_year = yearset + 1900;
530                }
531                t->tm_year -= 1900;     /* Convert to UNIX time. */
532                /* FALLTHROUGH */
533        case 8:				/* MMDDhhmm */
534                t->tm_mon = ATOI2(arg);
535                --t->tm_mon;    	/* Convert from 01-12 to 00-11 */
536                t->tm_mday = ATOI2(arg);
537                t->tm_hour = ATOI2(arg);
538                t->tm_min = ATOI2(arg);
539                break;
540        case 4:				/* hhmm */
541                t->tm_hour = ATOI2(arg);
542                t->tm_min = ATOI2(arg);
543                break;
544        default:
545                goto terr;
546        }
547        t->tm_isdst = -1;       	/* Figure out DST. */
548        timet = mktime(t);
549        if (timet == -1)
550terr:           errx(1,
551        "out of range or illegal time specification: [[CC]YY]MMDDhhmm[.SS]");
552        return timet;
553}
554
555
556/*
557 * onintr --
558 *	on interrupt, we inform the user how far we've gotten
559 */
560void
561onintr(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