xref: /freebsd/usr.bin/last/last.c (revision 1b6c76a2fe091c74f08427e6c870851025a9cf67)
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  * $FreeBSD$
34  */
35 
36 #ifndef lint
37 static 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
43 static 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 
67 static struct utmp	buf[1024];		/* utmp read buffer */
68 
69 typedef 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;
77 ARG	*arglist;				/* head of linked list */
78 
79 LIST_HEAD(ttylisthead, ttytab) ttylist;
80 
81 struct ttytab {
82 	time_t	logout;				/* log out time */
83 	char	tty[UT_LINESIZE + 1];		/* terminal name */
84 	LIST_ENTRY(ttytab) list;
85 };
86 
87 static long	currentout,			/* current logout value */
88 		maxrec;				/* records to display */
89 static const	char *file = _PATH_WTMP;		/* wtmp file */
90 static int	sflag = 0;			/* show delta in seconds */
91 static int	width = 5;			/* show seconds in delta */
92 static int      d_first;
93 static time_t	snaptime;			/* if != 0, we will only
94 						 * report users logged in
95 						 * at this snapshot time
96 						 */
97 
98 void	 addarg __P((int, char *));
99 time_t	 dateconv __P((char *));
100 void	 hostconv __P((char *));
101 void	 onintr __P((int));
102 char	*ttyconv __P((char *));
103 int	 want __P((struct utmp *));
104 void	 usage __P((void));
105 void	 wtmp __P((void));
106 
107 void
108 usage(void)
109 {
110 	(void)fprintf(stderr,
111 	"usage: last [-#] [-f file] [-h hostname] [-t tty] [-s|w] [user ...]\n");
112 	exit(1);
113 }
114 
115 int
116 main(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  */
191 void
192 wtmp()
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  */
372 int
373 want(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  */
406 void
407 addarg(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  */
427 void
428 hostconv(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  */
451 char *
452 ttyconv(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  */
484 time_t
485 dateconv(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)
546 terr:           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  */
556 void
557 onintr(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