last.c revision 78201 
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 78201 2001-06-14 04:55:26Z dd $
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 long	currentout,			/* current logout value */
88		maxrec;				/* records to display */
89static const	char *file = _PATH_WTMP;		/* wtmp file */
90static int	sflag = 0;			/* show delta in seconds */
91static int	width = 5;			/* show seconds in delta */
92static int      d_first;
93static time_t	snaptime;			/* if != 0, we will only
94						 * report users logged in
95						 * at this snapshot time
96						 */
97
98void	 addarg __P((int, char *));
99time_t	 dateconv __P((char *));
100void	 hostconv __P((char *));
101void	 onintr __P((int));
102char	*ttyconv __P((char *));
103int	 want __P((struct utmp *));
104void	 usage __P((void));
105void	 wtmp __P((void));
106
107void
108usage(void)
109{
110	(void)fprintf(stderr,
111	"usage: last [-#] [-f file] [-h hostname] [-t tty] [-s|w] [user ...]\n");
112	exit(1);
113}
114
115int
116main(argc, argv)
117	int argc;
118	char *argv[];
119{
120	int ch;
121	char *p;
122
123	(void) setlocale(LC_TIME, "");
124	d_first = (*nl_langinfo(D_MD_ORDER) == 'd');
125
126	maxrec = -1;
127	snaptime = 0;
128	while ((ch = getopt(argc, argv, "0123456789d:f:h:st:w")) != -1)
129		switch (ch) {
130		case '0': case '1': case '2': case '3': case '4':
131		case '5': case '6': case '7': case '8': case '9':
132			/*
133			 * kludge: last was originally designed to take
134			 * a number after a dash.
135			 */
136			if (maxrec == -1) {
137				p = argv[optind - 1];
138				if (p[0] == '-' && p[1] == ch && !p[2])
139					maxrec = atol(++p);
140				else
141					maxrec = atol(argv[optind] + 1);
142				if (!maxrec)
143					exit(0);
144			}
145			break;
146		case 'd':
147			snaptime = dateconv(optarg);
148			break;
149		case 'f':
150			file = optarg;
151			break;
152		case 'h':
153			hostconv(optarg);
154			addarg(HOST_TYPE, optarg);
155			break;
156		case 's':
157			sflag++;	/* Show delta as seconds */
158			break;
159		case 't':
160			addarg(TTY_TYPE, ttyconv(optarg));
161			break;
162		case 'w':
163			width = 8;
164			break;
165		case '?':
166		default:
167			usage();
168		}
169
170	if (sflag && width == 8) usage();
171
172	if (argc) {
173		setlinebuf(stdout);
174		for (argv += optind; *argv; ++argv) {
175#define	COMPATIBILITY
176#ifdef	COMPATIBILITY
177			/* code to allow "last p5" to work */
178			addarg(TTY_TYPE, ttyconv(*argv));
179#endif
180			addarg(USER_TYPE, *argv);
181		}
182	}
183	wtmp();
184	exit(0);
185}
186
187/*
188 * wtmp --
189 *	read through the wtmp file
190 */
191void
192wtmp()
193{
194	struct utmp	*bp;			/* current structure */
195	struct ttytab	*tt, *ttx;		/* ttylist entry */
196	struct stat	stb;			/* stat of file for size */
197	long	bl;
198	time_t	delta;				/* time difference */
199	int	bytes, wfd;
200	const	char *crmsg;
201	char ct[80];
202	struct tm *tm;
203	int	 snapfound = 0;			/* found snapshot entry? */
204
205	LIST_INIT(&ttylist);
206
207	if ((wfd = open(file, O_RDONLY, 0)) < 0 || fstat(wfd, &stb) == -1)
208		err(1, "%s", file);
209	bl = (stb.st_size + sizeof(buf) - 1) / sizeof(buf);
210
211	(void)time(&buf[0].ut_time);
212	(void)signal(SIGINT, onintr);
213	(void)signal(SIGQUIT, onintr);
214
215	while (--bl >= 0) {
216		if (lseek(wfd, (off_t)(bl * sizeof(buf)), L_SET) == -1 ||
217		    (bytes = read(wfd, buf, sizeof(buf))) == -1)
218			err(1, "%s", file);
219		for (bp = &buf[bytes / sizeof(buf[0]) - 1]; bp >= buf; --bp) {
220			/*
221			 * if the terminal line is '~', the machine stopped.
222			 * see utmp(5) for more info.
223			 */
224			if (bp->ut_line[0] == '~' && !bp->ut_line[1]) {
225				/* everybody just logged out */
226				for (tt = LIST_FIRST(&ttylist); tt;) {
227					LIST_REMOVE(tt, list);
228					ttx = tt;
229					tt = LIST_NEXT(tt, list);
230					free(ttx);
231				}
232				currentout = -bp->ut_time;
233				crmsg = strncmp(bp->ut_name, "shutdown",
234				    UT_NAMESIZE) ? "crash" : "shutdown";
235				/*
236				 * if we're in snapshot mode, we want to
237				 * exit if this shutdown/reboot appears
238				 * while we we are tracking the active
239				 * range
240				 */
241				if (snaptime && snapfound)
242					return;
243				/*
244				 * don't print shutdown/reboot entries
245				 * unless flagged for
246				 */
247				if (!snaptime && want(bp)) {
248					tm = localtime(&bp->ut_time);
249					(void) strftime(ct, sizeof(ct),
250						     d_first ? "%a %e %b %R" :
251							       "%a %b %e %R",
252						     tm);
253					printf("%-*.*s %-*.*s %-*.*s %s\n",
254					    UT_NAMESIZE, UT_NAMESIZE,
255					    bp->ut_name, UT_LINESIZE,
256					    UT_LINESIZE, bp->ut_line,
257					    UT_HOSTSIZE, UT_HOSTSIZE,
258					    bp->ut_host, ct);
259					if (maxrec != -1 && !--maxrec)
260						return;
261				}
262				continue;
263			}
264			/*
265			 * if the line is '{' or '|', date got set; see
266			 * utmp(5) for more info.
267			 */
268			if ((bp->ut_line[0] == '{' || bp->ut_line[0] == '|')
269			    && !bp->ut_line[1]) {
270				if (want(bp) && !snaptime) {
271					tm = localtime(&bp->ut_time);
272					(void) strftime(ct, sizeof(ct),
273						     d_first ? "%a %e %b %R" :
274							       "%a %b %e %R",
275						     tm);
276					printf("%-*.*s %-*.*s %-*.*s %s\n",
277					    UT_NAMESIZE, UT_NAMESIZE, bp->ut_name,
278					    UT_LINESIZE, UT_LINESIZE, bp->ut_line,
279					    UT_HOSTSIZE, UT_HOSTSIZE, bp->ut_host,
280					    ct);
281					if (maxrec && !--maxrec)
282						return;
283				}
284				continue;
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) ||
306			    (bp->ut_time < snaptime &&
307				(tt->logout > snaptime || tt->logout < 1)))) {
308				snapfound = 1;
309				/*
310				 * when uucp and ftp log in over a network, the entry in
311				 * the utmp file is the name plus their process id.  See
312				 * etc/ftpd.c and usr.bin/uucp/uucpd.c for more information.
313				 */
314				if (!strncmp(bp->ut_line, "ftp", sizeof("ftp") - 1))
315					bp->ut_line[3] = '\0';
316				else if (!strncmp(bp->ut_line, "uucp", sizeof("uucp") - 1))
317					bp->ut_line[4] = '\0';
318				tm = localtime(&bp->ut_time);
319				(void) strftime(ct, sizeof(ct),
320				    d_first ? "%a %e %b %R" :
321				    "%a %b %e %R",
322				    tm);
323				printf("%-*.*s %-*.*s %-*.*s %s ",
324				    UT_NAMESIZE, UT_NAMESIZE, bp->ut_name,
325				    UT_LINESIZE, UT_LINESIZE, bp->ut_line,
326				    UT_HOSTSIZE, UT_HOSTSIZE, bp->ut_host,
327				    ct);
328				if (!tt->logout)
329					puts("  still logged in");
330				else {
331					if (tt->logout < 0) {
332						tt->logout = -tt->logout;
333						printf("- %s", crmsg);
334					}
335					else {
336						tm = localtime(&tt->logout);
337						(void) strftime(ct, sizeof(ct), "%R", tm);
338						printf("- %s", ct);
339					}
340					delta = tt->logout - bp->ut_time;
341					if ( sflag ) {
342						printf("  (%8ld)\n",
343						    (long)delta);
344					} else {
345						tm = gmtime(&delta);
346						(void) strftime(ct, sizeof(ct),
347						    width >= 8 ? "%T" : "%R",
348						    tm);
349						if (delta < 86400)
350							printf("  (%s)\n", ct);
351						else
352							printf(" (%ld+%s)\n",
353							    (long)delta /
354							    86400, ct);
355					}
356				}
357				if (maxrec != -1 && !--maxrec)
358					return;
359			}
360			tt->logout = bp->ut_time;
361		}
362	}
363	tm = localtime(&buf[0].ut_time);
364	(void) strftime(ct, sizeof(ct), "\nwtmp begins %+\n", tm);
365	printf("%s", ct);
366}
367
368/*
369 * want --
370 *	see if want this entry
371 */
372int
373want(bp)
374	struct utmp *bp;
375{
376	ARG *step;
377
378	if (snaptime)
379		return (NO);
380
381	if (!arglist)
382		return (YES);
383
384	for (step = arglist; step; step = step->next)
385		switch(step->type) {
386		case HOST_TYPE:
387			if (!strncasecmp(step->name, bp->ut_host, UT_HOSTSIZE))
388				return (YES);
389			break;
390		case TTY_TYPE:
391			if (!strncmp(step->name, bp->ut_line, UT_LINESIZE))
392				return (YES);
393			break;
394		case USER_TYPE:
395			if (!strncmp(step->name, bp->ut_name, UT_NAMESIZE))
396				return (YES);
397			break;
398	}
399	return (NO);
400}
401
402/*
403 * addarg --
404 *	add an entry to a linked list of arguments
405 */
406void
407addarg(type, arg)
408	int type;
409	char *arg;
410{
411	ARG *cur;
412
413	if (!(cur = (ARG *)malloc((u_int)sizeof(ARG))))
414		err(1, "malloc failure");
415	cur->next = arglist;
416	cur->type = type;
417	cur->name = arg;
418	arglist = cur;
419}
420
421/*
422 * hostconv --
423 *	convert the hostname to search pattern; if the supplied host name
424 *	has a domain attached that is the same as the current domain, rip
425 *	off the domain suffix since that's what login(1) does.
426 */
427void
428hostconv(arg)
429	char *arg;
430{
431	static int first = 1;
432	static char *hostdot, name[MAXHOSTNAMELEN];
433	char *argdot;
434
435	if (!(argdot = strchr(arg, '.')))
436		return;
437	if (first) {
438		first = 0;
439		if (gethostname(name, sizeof(name)))
440			err(1, "gethostname");
441		hostdot = strchr(name, '.');
442	}
443	if (hostdot && !strcasecmp(hostdot, argdot))
444		*argdot = '\0';
445}
446
447/*
448 * ttyconv --
449 *	convert tty to correct name.
450 */
451char *
452ttyconv(arg)
453	char *arg;
454{
455	char *mval;
456
457	/*
458	 * kludge -- we assume that all tty's end with
459	 * a two character suffix.
460	 */
461	if (strlen(arg) == 2) {
462		/* either 6 for "ttyxx" or 8 for "console" */
463		if (!(mval = malloc((u_int)8)))
464			err(1, "malloc failure");
465		if (!strcmp(arg, "co"))
466			(void)strcpy(mval, "console");
467		else {
468			(void)strcpy(mval, "tty");
469			(void)strcpy(mval + 3, arg);
470		}
471		return (mval);
472	}
473	if (!strncmp(arg, _PATH_DEV, sizeof(_PATH_DEV) - 1))
474		return (arg + 5);
475	return (arg);
476}
477
478/*
479 * dateconv --
480 * 	Convert the snapshot time in command line given in the format
481 * 	[[CC]YY]MMDDhhmm[.SS]] to a time_t.
482 * 	Derived from atime_arg1() in usr.bin/touch/touch.c
483 */
484time_t
485dateconv(arg)
486        char *arg;
487{
488        time_t timet;
489        struct tm *t;
490        int yearset;
491        char *p;
492
493        /* Start with the current time. */
494        if (time(&timet) < 0)
495                err(1, "time");
496        if ((t = localtime(&timet)) == NULL)
497                err(1, "localtime");
498
499        /* [[CC]YY]MMDDhhmm[.SS] */
500        if ((p = strchr(arg, '.')) == NULL)
501                t->tm_sec = 0; 		/* Seconds defaults to 0. */
502        else {
503                if (strlen(p + 1) != 2)
504                        goto terr;
505                *p++ = '\0';
506                t->tm_sec = ATOI2(p);
507        }
508
509        yearset = 0;
510        switch (strlen(arg)) {
511        case 12:                	/* CCYYMMDDhhmm */
512                t->tm_year = ATOI2(arg);
513                t->tm_year *= 100;
514                yearset = 1;
515                /* FALLTHOUGH */
516        case 10:                	/* YYMMDDhhmm */
517                if (yearset) {
518                        yearset = ATOI2(arg);
519                        t->tm_year += yearset;
520                } else {
521                        yearset = ATOI2(arg);
522                        if (yearset < 69)
523                                t->tm_year = yearset + 2000;
524                        else
525                                t->tm_year = yearset + 1900;
526                }
527                t->tm_year -= 1900;     /* Convert to UNIX time. */
528                /* FALLTHROUGH */
529        case 8:				/* MMDDhhmm */
530                t->tm_mon = ATOI2(arg);
531                --t->tm_mon;    	/* Convert from 01-12 to 00-11 */
532                t->tm_mday = ATOI2(arg);
533                t->tm_hour = ATOI2(arg);
534                t->tm_min = ATOI2(arg);
535                break;
536        case 4:				/* hhmm */
537                t->tm_hour = ATOI2(arg);
538                t->tm_min = ATOI2(arg);
539                break;
540        default:
541                goto terr;
542        }
543        t->tm_isdst = -1;       	/* Figure out DST. */
544        timet = mktime(t);
545        if (timet == -1)
546terr:           errx(1,
547        "out of range or illegal time specification: [[CC]YY]MMDDhhmm[.SS]");
548        return timet;
549}
550
551
552/*
553 * onintr --
554 *	on interrupt, we inform the user how far we've gotten
555 */
556void
557onintr(signo)
558	int signo;
559{
560	char ct[80];
561	struct tm *tm;
562
563	tm = localtime(&buf[0].ut_time);
564	(void) strftime(ct, sizeof(ct),
565			d_first ? "%a %e %b %R" : "%a %b %e %R",
566			tm);
567	printf("\ninterrupted %s\n", ct);
568	if (signo == SIGINT)
569		exit(1);
570	(void)fflush(stdout);			/* fix required for rsh */
571}
572