last.c revision 125856 
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 125856 2004-02-15 21:52:59Z dwmalone $");
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 <timeconv.h>
61#include <unistd.h>
62#include <utmp.h>
63#include <sys/queue.h>
64
65#define	NO	0				/* false/no */
66#define	YES	1				/* true/yes */
67#define	ATOI2(ar)	((ar)[0] - '0') * 10 + ((ar)[1] - '0'); (ar) += 2;
68
69static struct utmp	buf[1024];		/* utmp read buffer */
70
71typedef struct arg {
72	char	*name;				/* argument */
73#define	HOST_TYPE	-2
74#define	TTY_TYPE	-3
75#define	USER_TYPE	-4
76	int	type;				/* type of arg */
77	struct arg	*next;			/* linked list pointer */
78} ARG;
79ARG	*arglist;				/* head of linked list */
80
81LIST_HEAD(ttylisthead, ttytab) ttylist;
82
83struct ttytab {
84	time_t	logout;				/* log out time */
85	char	tty[UT_LINESIZE + 1];		/* terminal name */
86	LIST_ENTRY(ttytab) list;
87};
88
89static const	char *crmsg;			/* cause of last reboot */
90static long	currentout,			/* current logout value */
91		maxrec;				/* records to display */
92static const	char *file = _PATH_WTMP;		/* wtmp file */
93static int	sflag = 0;			/* show delta in seconds */
94static int	width = 5;			/* show seconds in delta */
95static int	yflag;				/* show year */
96static int      d_first;
97static int	snapfound = 0;			/* found snapshot entry? */
98static time_t	snaptime;			/* if != 0, we will only
99						 * report users logged in
100						 * at this snapshot time
101						 */
102
103void	 addarg(int, char *);
104time_t	 dateconv(char *);
105void	 doentry(struct utmp *);
106void	 hostconv(char *);
107void	 onintr(int);
108void	 printentry(struct utmp *, struct ttytab *);
109char	*ttyconv(char *);
110int	 want(struct utmp *);
111void	 usage(void);
112void	 wtmp(void);
113
114void
115usage(void)
116{
117	(void)fprintf(stderr,
118"usage: last [-swy] [-d [[CC]YY][MMDD]hhmm[.SS]] [-f file] [-h host]\n"
119"            [-n maxrec] [-t tty] [user ...]\n");
120	exit(1);
121}
122
123int
124main(int argc, 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:n: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 = strchr(argv[optind - 1], ch);
144				if (p == NULL)
145					p = strchr(argv[optind], ch);
146				maxrec = atol(p);
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 'n':
162			errno = 0;
163			maxrec = strtol(optarg, &p, 10);
164			if (p == optarg || *p != '\0' || errno != 0 ||
165			    maxrec <= 0)
166				errx(1, "%s: bad line count", optarg);
167			break;
168		case 's':
169			sflag++;	/* Show delta as seconds */
170			break;
171		case 't':
172			addarg(TTY_TYPE, ttyconv(optarg));
173			break;
174		case 'w':
175			width = 8;
176			break;
177		case 'y':
178			yflag++;
179			break;
180		case '?':
181		default:
182			usage();
183		}
184
185	if (sflag && width == 8) usage();
186
187	if (argc) {
188		setlinebuf(stdout);
189		for (argv += optind; *argv; ++argv) {
190#define	COMPATIBILITY
191#ifdef	COMPATIBILITY
192			/* code to allow "last p5" to work */
193			addarg(TTY_TYPE, ttyconv(*argv));
194#endif
195			addarg(USER_TYPE, *argv);
196		}
197	}
198	wtmp();
199	exit(0);
200}
201
202/*
203 * wtmp --
204 *	read through the wtmp file
205 */
206void
207wtmp(void)
208{
209	struct utmp	*bp;			/* current structure */
210	struct stat	stb;			/* stat of file for size */
211	long	bl;
212	int	bytes, wfd;
213	char ct[80];
214	struct tm *tm;
215	time_t	t;
216
217	LIST_INIT(&ttylist);
218
219	if ((wfd = open(file, O_RDONLY, 0)) < 0 || fstat(wfd, &stb) == -1)
220		err(1, "%s", file);
221	bl = (stb.st_size + sizeof(buf) - 1) / sizeof(buf);
222
223	(void)time(&t);
224	buf[0].ut_time = _time_to_int(t);
225	(void)signal(SIGINT, onintr);
226	(void)signal(SIGQUIT, onintr);
227
228	while (--bl >= 0) {
229		if (lseek(wfd, (off_t)(bl * sizeof(buf)), L_SET) == -1 ||
230		    (bytes = read(wfd, buf, sizeof(buf))) == -1)
231			err(1, "%s", file);
232		for (bp = &buf[bytes / sizeof(buf[0]) - 1]; bp >= buf; --bp)
233			doentry(bp);
234	}
235	t = _int_to_time(buf[0].ut_time);
236	tm = localtime(&t);
237	(void) strftime(ct, sizeof(ct), "\nwtmp begins %+\n", tm);
238	printf("%s", ct);
239}
240
241/*
242 * doentry --
243 *	process a single wtmp entry
244 */
245void
246doentry(struct utmp *bp)
247{
248	struct ttytab	*tt, *ttx;		/* ttylist entry */
249
250	/*
251	 * if the terminal line is '~', the machine stopped.
252	 * see utmp(5) for more info.
253	 */
254	if (bp->ut_line[0] == '~' && !bp->ut_line[1]) {
255		/* everybody just logged out */
256		for (tt = LIST_FIRST(&ttylist); tt;) {
257			LIST_REMOVE(tt, list);
258			ttx = tt;
259			tt = LIST_NEXT(tt, list);
260			free(ttx);
261		}
262		currentout = -bp->ut_time;
263		crmsg = strncmp(bp->ut_name, "shutdown", UT_NAMESIZE) ?
264		    "crash" : "shutdown";
265		/*
266		 * if we're in snapshot mode, we want to exit if this
267		 * shutdown/reboot appears while we we are tracking the
268		 * active range
269		 */
270		if (snaptime && snapfound)
271			exit(0);
272		/*
273		 * don't print shutdown/reboot entries unless flagged for
274		 */
275		if (!snaptime && want(bp))
276			printentry(bp, NULL);
277		return;
278	}
279	/*
280	 * if the line is '{' or '|', date got set; see
281	 * utmp(5) for more info.
282	 */
283	if ((bp->ut_line[0] == '{' || bp->ut_line[0] == '|') &&
284	    !bp->ut_line[1]) {
285		if (want(bp) && !snaptime)
286			printentry(bp, NULL);
287		return;
288	}
289	/* find associated tty */
290	LIST_FOREACH(tt, &ttylist, list)
291	    if (!strncmp(tt->tty, bp->ut_line, UT_LINESIZE))
292		    break;
293
294	if (tt == NULL) {
295		/* add new one */
296		tt = malloc(sizeof(struct ttytab));
297		if (tt == NULL)
298			errx(1, "malloc failure");
299		tt->logout = currentout;
300		strncpy(tt->tty, bp->ut_line, UT_LINESIZE);
301		LIST_INSERT_HEAD(&ttylist, tt, list);
302	}
303
304	/*
305	 * print record if not in snapshot mode and wanted
306	 * or in snapshot mode and in snapshot range
307	 */
308	if (bp->ut_name[0] && (want(bp) || (bp->ut_time < snaptime &&
309	    (tt->logout > snaptime || tt->logout < 1)))) {
310		snapfound = 1;
311		/*
312		 * when uucp and ftp log in over a network, the entry in
313		 * the utmp file is the name plus their process id.  See
314		 * etc/ftpd.c and usr.bin/uucp/uucpd.c for more information.
315		 */
316		if (!strncmp(bp->ut_line, "ftp", sizeof("ftp") - 1))
317			bp->ut_line[3] = '\0';
318		else if (!strncmp(bp->ut_line, "uucp", sizeof("uucp") - 1))
319			bp->ut_line[4] = '\0';
320		printentry(bp, tt);
321	}
322	tt->logout = bp->ut_time;
323}
324
325/*
326 * printentry --
327 *	output an entry
328 *
329 * If `tt' is non-NULL, use it and `crmsg' to print the logout time or
330 * logout type (crash/shutdown) as appropriate.
331 */
332void
333printentry(struct utmp *bp, struct ttytab *tt)
334{
335	char ct[80];
336	struct tm *tm;
337	time_t	delta;				/* time difference */
338	time_t	t;
339
340	if (maxrec != -1 && !maxrec--)
341		exit(0);
342	t = _int_to_time(bp->ut_time);
343	tm = localtime(&t);
344	(void) strftime(ct, sizeof(ct), d_first ?
345	    (yflag ? "%a %e %b %Y %R" : "%a %e %b %R") :
346	    (yflag ? "%a %b %e %Y %R" : "%a %b %e %R"), tm);
347	printf("%-*.*s %-*.*s %-*.*s %s%c",
348	    UT_NAMESIZE, UT_NAMESIZE, bp->ut_name,
349	    UT_LINESIZE, UT_LINESIZE, bp->ut_line,
350	    UT_HOSTSIZE, UT_HOSTSIZE, bp->ut_host,
351	    ct, tt == NULL ? '\n' : ' ');
352	if (tt == NULL)
353		return;
354	if (!tt->logout) {
355		puts("  still logged in");
356		return;
357	}
358	if (tt->logout < 0) {
359		tt->logout = -tt->logout;
360		printf("- %s", crmsg);
361	} else {
362		tm = localtime(&tt->logout);
363		(void) strftime(ct, sizeof(ct), "%R", tm);
364		printf("- %s", ct);
365	}
366	delta = tt->logout - bp->ut_time;
367	if (sflag) {
368		printf("  (%8ld)\n", (long)delta);
369	} else {
370		tm = gmtime(&delta);
371		(void) strftime(ct, sizeof(ct), width >= 8 ? "%T" : "%R", tm);
372		if (delta < 86400)
373			printf("  (%s)\n", ct);
374		else
375			printf(" (%ld+%s)\n", (long)delta / 86400, ct);
376	}
377}
378
379/*
380 * want --
381 *	see if want this entry
382 */
383int
384want(struct utmp *bp)
385{
386	ARG *step;
387
388	if (snaptime)
389		return (NO);
390
391	if (!arglist)
392		return (YES);
393
394	for (step = arglist; step; step = step->next)
395		switch(step->type) {
396		case HOST_TYPE:
397			if (!strncasecmp(step->name, bp->ut_host, UT_HOSTSIZE))
398				return (YES);
399			break;
400		case TTY_TYPE:
401			if (!strncmp(step->name, bp->ut_line, UT_LINESIZE))
402				return (YES);
403			break;
404		case USER_TYPE:
405			if (!strncmp(step->name, bp->ut_name, UT_NAMESIZE))
406				return (YES);
407			break;
408		}
409	return (NO);
410}
411
412/*
413 * addarg --
414 *	add an entry to a linked list of arguments
415 */
416void
417addarg(int type, 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(char *arg)
437{
438	static int first = 1;
439	static char *hostdot, name[MAXHOSTNAMELEN];
440	char *argdot;
441
442	if (!(argdot = strchr(arg, '.')))
443		return;
444	if (first) {
445		first = 0;
446		if (gethostname(name, sizeof(name)))
447			err(1, "gethostname");
448		hostdot = strchr(name, '.');
449	}
450	if (hostdot && !strcasecmp(hostdot, argdot))
451		*argdot = '\0';
452}
453
454/*
455 * ttyconv --
456 *	convert tty to correct name.
457 */
458char *
459ttyconv(char *arg)
460{
461	char *mval;
462
463	/*
464	 * kludge -- we assume that all tty's end with
465	 * a two character suffix.
466	 */
467	if (strlen(arg) == 2) {
468		/* either 6 for "ttyxx" or 8 for "console" */
469		if ((mval = malloc(8)) == NULL)
470			errx(1, "malloc failure");
471		if (!strcmp(arg, "co"))
472			(void)strcpy(mval, "console");
473		else {
474			(void)strcpy(mval, "tty");
475			(void)strcpy(mval + 3, arg);
476		}
477		return (mval);
478	}
479	if (!strncmp(arg, _PATH_DEV, sizeof(_PATH_DEV) - 1))
480		return (arg + 5);
481	return (arg);
482}
483
484/*
485 * dateconv --
486 * 	Convert the snapshot time in command line given in the format
487 * 	[[CC]YY]MMDDhhmm[.SS]] to a time_t.
488 * 	Derived from atime_arg1() in usr.bin/touch/touch.c
489 */
490time_t
491dateconv(char *arg)
492{
493        time_t timet;
494        struct tm *t;
495        int yearset;
496        char *p;
497
498        /* Start with the current time. */
499        if (time(&timet) < 0)
500                err(1, "time");
501        if ((t = localtime(&timet)) == NULL)
502                err(1, "localtime");
503
504        /* [[CC]YY]MMDDhhmm[.SS] */
505        if ((p = strchr(arg, '.')) == NULL)
506                t->tm_sec = 0; 		/* Seconds defaults to 0. */
507        else {
508                if (strlen(p + 1) != 2)
509                        goto terr;
510                *p++ = '\0';
511                t->tm_sec = ATOI2(p);
512        }
513
514        yearset = 0;
515        switch (strlen(arg)) {
516        case 12:                	/* CCYYMMDDhhmm */
517                t->tm_year = ATOI2(arg);
518                t->tm_year *= 100;
519                yearset = 1;
520                /* FALLTHOUGH */
521        case 10:                	/* YYMMDDhhmm */
522                if (yearset) {
523                        yearset = ATOI2(arg);
524                        t->tm_year += yearset;
525                } else {
526                        yearset = ATOI2(arg);
527                        if (yearset < 69)
528                                t->tm_year = yearset + 2000;
529                        else
530                                t->tm_year = yearset + 1900;
531                }
532                t->tm_year -= 1900;     /* Convert to UNIX time. */
533                /* FALLTHROUGH */
534        case 8:				/* MMDDhhmm */
535                t->tm_mon = ATOI2(arg);
536                --t->tm_mon;    	/* Convert from 01-12 to 00-11 */
537                t->tm_mday = ATOI2(arg);
538                t->tm_hour = ATOI2(arg);
539                t->tm_min = ATOI2(arg);
540                break;
541        case 4:				/* hhmm */
542                t->tm_hour = ATOI2(arg);
543                t->tm_min = ATOI2(arg);
544                break;
545        default:
546                goto terr;
547        }
548        t->tm_isdst = -1;       	/* Figure out DST. */
549        timet = mktime(t);
550        if (timet == -1)
551terr:           errx(1,
552        "out of range or illegal time specification: [[CC]YY]MMDDhhmm[.SS]");
553        return timet;
554}
555
556
557/*
558 * onintr --
559 *	on interrupt, we inform the user how far we've gotten
560 */
561void
562onintr(int signo)
563{
564	char ct[80];
565	struct tm *tm;
566	time_t t = _int_to_time(buf[0].ut_time);
567
568	tm = localtime(&t);
569	(void) strftime(ct, sizeof(ct),
570			d_first ? "%a %e %b %R" : "%a %b %e %R",
571			tm);
572	printf("\ninterrupted %s\n", ct);
573	if (signo == SIGINT)
574		exit(1);
575	(void)fflush(stdout);			/* fix required for rsh */
576}
577