xref: /dragonfly/usr.bin/last/last.c (revision c9f721c2)
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: src/usr.bin/last/last.c,v 1.10.6.11 2002/11/02 23:00:26 mux Exp $
34  * $DragonFly: src/usr.bin/last/last.c,v 1.5 2004/09/14 00:13:36 drhodus Exp $
35  *
36  * @(#) Copyright (c) 1987, 1993, 1994 The Regents of the University of California.  All rights reserved.
37  * @(#)last.c	8.2 (Berkeley) 4/2/94
38  */
39 
40 #include <sys/param.h>
41 #include <sys/stat.h>
42 
43 #include <err.h>
44 #include <fcntl.h>
45 #include <langinfo.h>
46 #include <locale.h>
47 #include <paths.h>
48 #include <signal.h>
49 #include <stdio.h>
50 #include <stdlib.h>
51 #include <string.h>
52 #include <time.h>
53 #include <unistd.h>
54 #include <utmp.h>
55 #include <sys/queue.h>
56 
57 #define	NO	0				/* false/no */
58 #define	YES	1				/* true/yes */
59 #define	ATOI2(ar)	((ar)[0] - '0') * 10 + ((ar)[1] - '0'); (ar) += 2;
60 
61 static struct utmp	buf[1024];		/* utmp read buffer */
62 
63 typedef struct arg {
64 	char	*name;				/* argument */
65 #define	HOST_TYPE	-2
66 #define	TTY_TYPE	-3
67 #define	USER_TYPE	-4
68 	int	type;				/* type of arg */
69 	struct arg	*next;			/* linked list pointer */
70 } ARG;
71 ARG	*arglist;				/* head of linked list */
72 
73 LIST_HEAD(ttylisthead, ttytab) ttylist;
74 
75 struct ttytab {
76 	time_t	logout;				/* log out time */
77 	char	tty[UT_LINESIZE + 1];		/* terminal name */
78 	LIST_ENTRY(ttytab) list;
79 };
80 
81 static const	char *crmsg;			/* cause of last reboot */
82 static long	currentout,			/* current logout value */
83 		maxrec;				/* records to display */
84 static const	char *file = _PATH_WTMP;		/* wtmp file */
85 static int	sflag = 0;			/* show delta in seconds */
86 static int	width = 5;			/* show seconds in delta */
87 static int	yflag;				/* show year */
88 static int      d_first;
89 static int	snapfound = 0;			/* found snapshot entry? */
90 static time_t	snaptime;			/* if != 0, we will only
91 						 * report users logged in
92 						 * at this snapshot time
93 						 */
94 
95 int	 main(int, char *[]);
96 void	 addarg(int, char *);
97 time_t	 dateconv(char *);
98 void	 doentry(struct utmp *);
99 void	 hostconv(char *);
100 void	 onintr(int);
101 void	 printentry(struct utmp *, struct ttytab *);
102 char	*ttyconv(char *);
103 char	*ttyconv(char *);
104 int	 want(struct utmp *);
105 void	 usage(void);
106 void	 wtmp(void);
107 
108 void
109 usage(void)
110 {
111 	(void)fprintf(stderr,
112 "usage: last [-#] [-y] [-d [[CC]YY][MMDD]hhmm[.SS]] [-f file] [-h host]\n"
113 "\t[-t tty] [-s|w] [user ...]\n");
114 	exit(1);
115 }
116 
117 int
118 main(int argc, 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:wy")) != -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 = strchr(argv[optind - 1], ch);
138 				if (p == NULL)
139 					p = strchr(argv[optind], ch);
140 				maxrec = atol(p);
141 				if (!maxrec)
142 					exit(0);
143 			}
144 			break;
145 		case 'd':
146 			snaptime = dateconv(optarg);
147 			break;
148 		case 'f':
149 			file = optarg;
150 			break;
151 		case 'h':
152 			hostconv(optarg);
153 			addarg(HOST_TYPE, optarg);
154 			break;
155 		case 's':
156 			sflag++;	/* Show delta as seconds */
157 			break;
158 		case 't':
159 			addarg(TTY_TYPE, ttyconv(optarg));
160 			break;
161 		case 'w':
162 			width = 8;
163 			break;
164 		case 'y':
165 			yflag++;
166 			break;
167 		case '?':
168 		default:
169 			usage();
170 		}
171 
172 	if (sflag && width == 8) usage();
173 
174 	if (argc) {
175 		setlinebuf(stdout);
176 		for (argv += optind; *argv; ++argv) {
177 #define	COMPATIBILITY
178 #ifdef	COMPATIBILITY
179 			/* code to allow "last p5" to work */
180 			addarg(TTY_TYPE, ttyconv(*argv));
181 #endif
182 			addarg(USER_TYPE, *argv);
183 		}
184 	}
185 	wtmp();
186 	exit(0);
187 }
188 
189 /*
190  * wtmp --
191  *	read through the wtmp file
192  */
193 void
194 wtmp(void)
195 {
196 	struct utmp	*bp;			/* current structure */
197 	struct stat	stb;			/* stat of file for size */
198 	long	bl;
199 	int	bytes, wfd;
200 	char ct[80];
201 	struct tm *tm;
202 
203 	LIST_INIT(&ttylist);
204 
205 	if ((wfd = open(file, O_RDONLY, 0)) < 0 || fstat(wfd, &stb) == -1)
206 		err(1, "%s", file);
207 	bl = (stb.st_size + sizeof(buf) - 1) / sizeof(buf);
208 
209 	(void)time(&buf[0].ut_time);
210 	(void)signal(SIGINT, onintr);
211 	(void)signal(SIGQUIT, onintr);
212 
213 	while (--bl >= 0) {
214 		if (lseek(wfd, (off_t)(bl * sizeof(buf)), L_SET) == -1 ||
215 		    (bytes = read(wfd, buf, sizeof(buf))) == -1)
216 			err(1, "%s", file);
217 		for (bp = &buf[bytes / sizeof(buf[0]) - 1]; bp >= buf; --bp)
218 			doentry(bp);
219 	}
220 	tm = localtime(&buf[0].ut_time);
221 	(void) strftime(ct, sizeof(ct), "\nwtmp begins %+\n", tm);
222 	printf("%s", ct);
223 }
224 
225 /*
226  * doentry --
227  *	process a single wtmp entry
228  */
229 void
230 doentry(struct utmp *bp)
231 {
232 	struct ttytab	*tt, *ttx;		/* ttylist entry */
233 
234 	/*
235 	 * if the terminal line is '~', the machine stopped.
236 	 * see utmp(5) for more info.
237 	 */
238 	if (bp->ut_line[0] == '~' && !bp->ut_line[1]) {
239 		/* everybody just logged out */
240 		for (tt = LIST_FIRST(&ttylist); tt;) {
241 			LIST_REMOVE(tt, list);
242 			ttx = tt;
243 			tt = LIST_NEXT(tt, list);
244 			free(ttx);
245 		}
246 		currentout = -bp->ut_time;
247 		crmsg = strncmp(bp->ut_name, "shutdown", UT_NAMESIZE) ?
248 		    "crash" : "shutdown";
249 		/*
250 		 * if we're in snapshot mode, we want to exit if this
251 		 * shutdown/reboot appears while we we are tracking the
252 		 * active range
253 		 */
254 		if (snaptime && snapfound)
255 			exit(0);
256 		/*
257 		 * don't print shutdown/reboot entries unless flagged for
258 		 */
259 		if (!snaptime && want(bp))
260 			printentry(bp, NULL);
261 		return;
262 	}
263 	/*
264 	 * if the line is '{' or '|', date got set; see
265 	 * utmp(5) for more info.
266 	 */
267 	if ((bp->ut_line[0] == '{' || bp->ut_line[0] == '|') &&
268 	    !bp->ut_line[1]) {
269 		if (want(bp) && !snaptime)
270 			printentry(bp, NULL);
271 		return;
272 	}
273 	/* find associated tty */
274 	LIST_FOREACH(tt, &ttylist, list)
275 	    if (!strncmp(tt->tty, bp->ut_line, UT_LINESIZE))
276 		    break;
277 
278 	if (tt == NULL) {
279 		/* add new one */
280 		tt = malloc(sizeof(struct ttytab));
281 		if (tt == NULL)
282 			err(1, "malloc failure");
283 		tt->logout = currentout;
284 		strncpy(tt->tty, bp->ut_line, UT_LINESIZE);
285 		LIST_INSERT_HEAD(&ttylist, tt, list);
286 	}
287 
288 	/*
289 	 * print record if not in snapshot mode and wanted
290 	 * or in snapshot mode and in snapshot range
291 	 */
292 	if (bp->ut_name[0] && (want(bp) || (bp->ut_time < snaptime &&
293 	    (tt->logout > snaptime || tt->logout < 1)))) {
294 		snapfound = 1;
295 		/*
296 		 * when uucp and ftp log in over a network, the entry in
297 		 * the utmp file is the name plus their process id.  See
298 		 * etc/ftpd.c and usr.bin/uucp/uucpd.c for more information.
299 		 */
300 		if (!strncmp(bp->ut_line, "ftp", sizeof("ftp") - 1))
301 			bp->ut_line[3] = '\0';
302 		else if (!strncmp(bp->ut_line, "uucp", sizeof("uucp") - 1))
303 			bp->ut_line[4] = '\0';
304 		printentry(bp, tt);
305 	}
306 	tt->logout = bp->ut_time;
307 }
308 
309 /*
310  * printentry --
311  *	output an entry
312  *
313  * If `tt' is non-NULL, use it and `crmsg' to print the logout time or
314  * logout type (crash/shutdown) as appropriate.
315  */
316 void
317 printentry(struct utmp *bp, struct ttytab *tt)
318 {
319 	char ct[80];
320 	struct tm *tm;
321 	time_t	delta;				/* time difference */
322 
323 	if (maxrec != -1 && !maxrec--)
324 		exit(0);
325 	tm = localtime(&bp->ut_time);
326 	(void) strftime(ct, sizeof(ct), d_first ?
327 	    (yflag ? "%a %e %b %Y %R" : "%a %e %b %R") :
328 	    (yflag ? "%a %b %e %Y %R" : "%a %b %e %R"), tm);
329 	printf("%-*.*s %-*.*s %-*.*s %s%c",
330 	    UT_NAMESIZE, UT_NAMESIZE, bp->ut_name,
331 	    UT_LINESIZE, UT_LINESIZE, bp->ut_line,
332 	    UT_HOSTSIZE, UT_HOSTSIZE, bp->ut_host,
333 	    ct, tt == NULL ? '\n' : ' ');
334 	if (tt == NULL)
335 		return;
336 	if (!tt->logout) {
337 		puts("  still logged in");
338 		return;
339 	}
340 	if (tt->logout < 0) {
341 		tt->logout = -tt->logout;
342 		printf("- %s", crmsg);
343 	} else {
344 		tm = localtime(&tt->logout);
345 		(void) strftime(ct, sizeof(ct), "%R", tm);
346 		printf("- %s", ct);
347 	}
348 	delta = tt->logout - bp->ut_time;
349 	if (sflag) {
350 		printf("  (%8ld)\n", (long)delta);
351 	} else {
352 		tm = gmtime(&delta);
353 		(void) strftime(ct, sizeof(ct), width >= 8 ? "%T" : "%R", tm);
354 		if (delta < 86400)
355 			printf("  (%s)\n", ct);
356 		else
357 			printf(" (%ld+%s)\n", (long)delta / 86400, ct);
358 	}
359 }
360 
361 /*
362  * want --
363  *	see if want this entry
364  */
365 int
366 want(struct utmp *bp)
367 {
368 	ARG *step;
369 
370 	if (snaptime)
371 		return (NO);
372 
373 	if (!arglist)
374 		return (YES);
375 
376 	for (step = arglist; step; step = step->next)
377 		switch(step->type) {
378 		case HOST_TYPE:
379 			if (!strncasecmp(step->name, bp->ut_host, UT_HOSTSIZE))
380 				return (YES);
381 			break;
382 		case TTY_TYPE:
383 			if (!strncmp(step->name, bp->ut_line, UT_LINESIZE))
384 				return (YES);
385 			break;
386 		case USER_TYPE:
387 			if (!strncmp(step->name, bp->ut_name, UT_NAMESIZE))
388 				return (YES);
389 			break;
390 		}
391 	return (NO);
392 }
393 
394 /*
395  * addarg --
396  *	add an entry to a linked list of arguments
397  */
398 void
399 addarg(int type, char *arg)
400 {
401 	ARG *cur;
402 
403 	if (!(cur = (ARG *)malloc((u_int)sizeof(ARG))))
404 		err(1, "malloc failure");
405 	cur->next = arglist;
406 	cur->type = type;
407 	cur->name = arg;
408 	arglist = cur;
409 }
410 
411 /*
412  * hostconv --
413  *	convert the hostname to search pattern; if the supplied host name
414  *	has a domain attached that is the same as the current domain, rip
415  *	off the domain suffix since that's what login(1) does.
416  */
417 void
418 hostconv(char *arg)
419 {
420 	static int first = 1;
421 	static char *hostdot, name[MAXHOSTNAMELEN];
422 	char *argdot;
423 
424 	if (!(argdot = strchr(arg, '.')))
425 		return;
426 	if (first) {
427 		first = 0;
428 		if (gethostname(name, sizeof(name)))
429 			err(1, "gethostname");
430 		hostdot = strchr(name, '.');
431 	}
432 	if (hostdot && !strcasecmp(hostdot, argdot))
433 		*argdot = '\0';
434 }
435 
436 /*
437  * ttyconv --
438  *	convert tty to correct name.
439  */
440 char *
441 ttyconv(char *arg)
442 {
443 	char *mval;
444 
445 	/*
446 	 * kludge -- we assume that all tty's end with
447 	 * a two character suffix.
448 	 */
449 	if (strlen(arg) == 2) {
450 		/* either 6 for "ttyxx" or 8 for "console" */
451 		if (!(mval = malloc((u_int)8)))
452 			err(1, "malloc failure");
453 		if (!strcmp(arg, "co"))
454 			(void)strcpy(mval, "console");
455 		else {
456 			(void)strcpy(mval, "tty");
457 			(void)strcpy(mval + 3, arg);
458 		}
459 		return (mval);
460 	}
461 	if (!strncmp(arg, _PATH_DEV, sizeof(_PATH_DEV) - 1))
462 		return (arg + 5);
463 	return (arg);
464 }
465 
466 /*
467  * dateconv --
468  * 	Convert the snapshot time in command line given in the format
469  * 	[[CC]YY]MMDDhhmm[.SS]] to a time_t.
470  * 	Derived from atime_arg1() in usr.bin/touch/touch.c
471  */
472 time_t
473 dateconv(char *arg)
474 {
475         time_t timet;
476         struct tm *t;
477         int yearset;
478         char *p;
479 
480         /* Start with the current time. */
481         if (time(&timet) < 0)
482                 err(1, "time");
483         if ((t = localtime(&timet)) == NULL)
484                 err(1, "localtime");
485 
486         /* [[CC]YY]MMDDhhmm[.SS] */
487         if ((p = strchr(arg, '.')) == NULL)
488                 t->tm_sec = 0; 		/* Seconds defaults to 0. */
489         else {
490                 if (strlen(p + 1) != 2)
491                         goto terr;
492                 *p++ = '\0';
493                 t->tm_sec = ATOI2(p);
494         }
495 
496         yearset = 0;
497         switch (strlen(arg)) {
498         case 12:                	/* CCYYMMDDhhmm */
499                 t->tm_year = ATOI2(arg);
500                 t->tm_year *= 100;
501                 yearset = 1;
502                 /* FALLTHROUGH */
503         case 10:                	/* YYMMDDhhmm */
504                 if (yearset) {
505                         yearset = ATOI2(arg);
506                         t->tm_year += yearset;
507                 } else {
508                         yearset = ATOI2(arg);
509                         if (yearset < 69)
510                                 t->tm_year = yearset + 2000;
511                         else
512                                 t->tm_year = yearset + 1900;
513                 }
514                 t->tm_year -= 1900;     /* Convert to UNIX time. */
515                 /* FALLTHROUGH */
516         case 8:				/* MMDDhhmm */
517                 t->tm_mon = ATOI2(arg);
518                 --t->tm_mon;    	/* Convert from 01-12 to 00-11 */
519                 t->tm_mday = ATOI2(arg);
520                 t->tm_hour = ATOI2(arg);
521                 t->tm_min = ATOI2(arg);
522                 break;
523         case 4:				/* hhmm */
524                 t->tm_hour = ATOI2(arg);
525                 t->tm_min = ATOI2(arg);
526                 break;
527         default:
528                 goto terr;
529         }
530         t->tm_isdst = -1;       	/* Figure out DST. */
531         timet = mktime(t);
532         if (timet == -1)
533 terr:           errx(1,
534         "out of range or illegal time specification: [[CC]YY]MMDDhhmm[.SS]");
535         return timet;
536 }
537 
538 
539 /*
540  * onintr --
541  *	on interrupt, we inform the user how far we've gotten
542  */
543 void
544 onintr(int signo)
545 {
546 	char ct[80];
547 	struct tm *tm;
548 
549 	tm = localtime(&buf[0].ut_time);
550 	(void) strftime(ct, sizeof(ct),
551 			d_first ? "%a %e %b %R" : "%a %b %e %R",
552 			tm);
553 	printf("\ninterrupted %s\n", ct);
554 	if (signo == SIGINT)
555 		exit(1);
556 	(void)fflush(stdout);			/* fix required for rsh */
557 }
558