xref: /freebsd/usr.bin/last/last.c (revision 952d112864d8008aa87278a30a539d888a8493cd)
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
35 static 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
41 static char sccsid[] = "@(#)last.c	8.2 (Berkeley) 4/2/94";
42 #endif /* not lint */
43 
44 #include <sys/param.h>
45 #include <sys/stat.h>
46 
47 #include <err.h>
48 #include <fcntl.h>
49 #include <locale.h>
50 #include <paths.h>
51 #include <signal.h>
52 #include <stdio.h>
53 #include <stdlib.h>
54 #include <string.h>
55 #include <time.h>
56 #include <unistd.h>
57 #include <utmp.h>
58 #include <sys/queue.h>
59 
60 #define	NO	0				/* false/no */
61 #define	YES	1				/* true/yes */
62 
63 static struct utmp	buf[1024];		/* utmp read buffer */
64 
65 typedef struct arg {
66 	char	*name;				/* argument */
67 #define	HOST_TYPE	-2
68 #define	TTY_TYPE	-3
69 #define	USER_TYPE	-4
70 	int	type;				/* type of arg */
71 	struct arg	*next;			/* linked list pointer */
72 } ARG;
73 ARG	*arglist;				/* head of linked list */
74 
75 LIST_HEAD(ttylisthead, ttytab) ttylist;
76 
77 struct ttytab {
78 	long	logout;				/* log out time */
79 	char	tty[UT_LINESIZE + 1];		/* terminal name */
80 	LIST_ENTRY(ttytab) list;
81 };
82 
83 static long	currentout,			/* current logout value */
84 		maxrec;				/* records to display */
85 static char	*file = _PATH_WTMP;		/* wtmp file */
86 
87 void	 addarg __P((int, char *));
88 void	 hostconv __P((char *));
89 void	 onintr __P((int));
90 char	*ttyconv __P((char *));
91 int	 want __P((struct utmp *));
92 void	 wtmp __P((void));
93 
94 int
95 main(argc, argv)
96 	int argc;
97 	char *argv[];
98 {
99 	extern int optind;
100 	extern char *optarg;
101 	int ch;
102 	char *p;
103 
104 	(void) setlocale(LC_TIME, "");
105 
106 	maxrec = -1;
107 	while ((ch = getopt(argc, argv, "0123456789f:h:t:")) != -1)
108 		switch (ch) {
109 		case '0': case '1': case '2': case '3': case '4':
110 		case '5': case '6': case '7': case '8': case '9':
111 			/*
112 			 * kludge: last was originally designed to take
113 			 * a number after a dash.
114 			 */
115 			if (maxrec == -1) {
116 				p = argv[optind - 1];
117 				if (p[0] == '-' && p[1] == ch && !p[2])
118 					maxrec = atol(++p);
119 				else
120 					maxrec = atol(argv[optind] + 1);
121 				if (!maxrec)
122 					exit(0);
123 			}
124 			break;
125 		case 'f':
126 			file = optarg;
127 			break;
128 		case 'h':
129 			hostconv(optarg);
130 			addarg(HOST_TYPE, optarg);
131 			break;
132 		case 't':
133 			addarg(TTY_TYPE, ttyconv(optarg));
134 			break;
135 		case '?':
136 		default:
137 			(void)fprintf(stderr,
138 	"usage: last [-#] [-f file] [-t tty] [-h hostname] [user ...]\n");
139 			exit(1);
140 		}
141 
142 	if (argc) {
143 		setlinebuf(stdout);
144 		for (argv += optind; *argv; ++argv) {
145 #define	COMPATIBILITY
146 #ifdef	COMPATIBILITY
147 			/* code to allow "last p5" to work */
148 			addarg(TTY_TYPE, ttyconv(*argv));
149 #endif
150 			addarg(USER_TYPE, *argv);
151 		}
152 	}
153 	wtmp();
154 	exit(0);
155 }
156 
157 /*
158  * wtmp --
159  *	read through the wtmp file
160  */
161 void
162 wtmp()
163 {
164 	struct utmp	*bp;			/* current structure */
165 	struct ttytab	*tt, *ttx;		/* ttylist entry */
166 	struct stat	stb;			/* stat of file for size */
167 	long	bl, delta;			/* time difference */
168 	int	bytes, wfd;
169 	char    *crmsg;
170 	char ct[80];
171 	struct tm *tm;
172 
173 	LIST_INIT(&ttylist);
174 
175 	if ((wfd = open(file, O_RDONLY, 0)) < 0 || fstat(wfd, &stb) == -1)
176 		err(1, "%s", file);
177 	bl = (stb.st_size + sizeof(buf) - 1) / sizeof(buf);
178 
179 	(void)time(&buf[0].ut_time);
180 	(void)signal(SIGINT, onintr);
181 	(void)signal(SIGQUIT, onintr);
182 
183 	while (--bl >= 0) {
184 		if (lseek(wfd, (off_t)(bl * sizeof(buf)), L_SET) == -1 ||
185 		    (bytes = read(wfd, buf, sizeof(buf))) == -1)
186 			err(1, "%s", file);
187 		for (bp = &buf[bytes / sizeof(buf[0]) - 1]; bp >= buf; --bp) {
188 			/*
189 			 * if the terminal line is '~', the machine stopped.
190 			 * see utmp(5) for more info.
191 			 */
192 			if (bp->ut_line[0] == '~' && !bp->ut_line[1]) {
193 				/* everybody just logged out */
194 				for (tt = ttylist.lh_first; tt;) {
195 					LIST_REMOVE(tt, list);
196 					ttx = tt;
197 					tt = tt->list.le_next;
198 					free(ttx);
199 				}
200 				currentout = -bp->ut_time;
201 				crmsg = strncmp(bp->ut_name, "shutdown",
202 				    UT_NAMESIZE) ? "crash" : "shutdown";
203 				if (want(bp)) {
204 					tm = localtime(&bp->ut_time);
205 					(void) strftime(ct, sizeof(ct), "%c", tm);
206 					printf("%-*.*s %-*.*s %-*.*s %10.10s %5.5s \n",
207 					    UT_NAMESIZE, UT_NAMESIZE,
208 					    bp->ut_name, UT_LINESIZE,
209 					    UT_LINESIZE, bp->ut_line,
210 					    UT_HOSTSIZE, UT_HOSTSIZE,
211 					    bp->ut_host, ct, ct + 11);
212 					if (maxrec != -1 && !--maxrec)
213 						return;
214 				}
215 				continue;
216 			}
217 			/*
218 			 * if the line is '{' or '|', date got set; see
219 			 * utmp(5) for more info.
220 			 */
221 			if ((bp->ut_line[0] == '{' || bp->ut_line[0] == '|')
222 			    && !bp->ut_line[1]) {
223 				if (want(bp)) {
224 					tm = localtime(&bp->ut_time);
225 					(void) strftime(ct, sizeof(ct), "%c", tm);
226 					printf("%-*.*s %-*.*s %-*.*s %10.10s %5.5s \n",
227 					    UT_NAMESIZE, UT_NAMESIZE, bp->ut_name,
228 					    UT_LINESIZE, UT_LINESIZE, bp->ut_line,
229 					    UT_HOSTSIZE, UT_HOSTSIZE, bp->ut_host,
230 					    ct, ct + 11);
231 					if (maxrec && !--maxrec)
232 						return;
233 				}
234 				continue;
235 			}
236 			if (bp->ut_name[0] == '\0' || want(bp)) {
237 				/* find associated tty */
238 				for (tt = ttylist.lh_first; ; tt = tt->list.le_next) {
239 					if (tt == NULL) {
240 						/* add new one */
241 						tt = malloc(sizeof(struct ttytab));
242 						if (tt == NULL)
243 							err(1, "malloc failure");
244 						tt->logout = currentout;
245 						strncpy(tt->tty, bp->ut_line, UT_LINESIZE);
246 						LIST_INSERT_HEAD(&ttylist, tt, list);
247 						break;
248 					}
249 					if (!strncmp(tt->tty, bp->ut_line, UT_LINESIZE))
250 						break;
251 				}
252 				if (bp->ut_name[0]) {
253 					/*
254 					 * when uucp and ftp log in over a network, the entry in
255 					 * the utmp file is the name plus their process id.  See
256 					 * etc/ftpd.c and usr.bin/uucp/uucpd.c for more information.
257 					 */
258 					if (!strncmp(bp->ut_line, "ftp", sizeof("ftp") - 1))
259 						bp->ut_line[3] = '\0';
260 					else if (!strncmp(bp->ut_line, "uucp", sizeof("uucp") - 1))
261 						bp->ut_line[4] = '\0';
262 					tm = localtime(&bp->ut_time);
263 					(void) strftime(ct, sizeof(ct), "%c", tm);
264 					printf("%-*.*s %-*.*s %-*.*s %10.10s %5.5s ",
265 					    UT_NAMESIZE, UT_NAMESIZE, bp->ut_name,
266 					    UT_LINESIZE, UT_LINESIZE, bp->ut_line,
267 					    UT_HOSTSIZE, UT_HOSTSIZE, bp->ut_host,
268 					    ct, ct + 11);
269 					if (!tt->logout)
270 						puts("  still logged in");
271 					else {
272 						if (tt->logout < 0) {
273 							tt->logout = -tt->logout;
274 							printf("- %s", crmsg);
275 						}
276 						else {
277 							tm = localtime(&tt->logout);
278 							(void) strftime(ct, sizeof(ct), "%c", tm);
279 							printf("- %5.5s", ct + 11);
280 						}
281 						delta = tt->logout - bp->ut_time;
282 						tm = gmtime(&delta);
283 						(void) strftime(ct, sizeof(ct), "%c", tm);
284 						if (delta < 86400)
285 							printf("  (%5.5s)\n", ct + 11);
286 						else
287 							printf(" (%ld+%5.5s)\n",
288 							    delta / 86400, ct + 11);
289 					}
290 					LIST_REMOVE(tt, list);
291 					free(tt);
292 					if (maxrec != -1 && !--maxrec)
293 						return;
294 				} else {
295 					tt->logout = bp->ut_time;
296 				}
297 			}
298 		}
299 	}
300 	tm = localtime(&buf[0].ut_time);
301 	(void) strftime(ct, sizeof(ct), "%c", tm);
302 	printf("\nwtmp begins %10.10s %5.5s \n", ct, ct + 11);
303 }
304 
305 /*
306  * want --
307  *	see if want this entry
308  */
309 int
310 want(bp)
311 	struct utmp *bp;
312 {
313 	ARG *step;
314 
315 	if (!arglist)
316 		return (YES);
317 
318 	for (step = arglist; step; step = step->next)
319 		switch(step->type) {
320 		case HOST_TYPE:
321 			if (!strncasecmp(step->name, bp->ut_host, UT_HOSTSIZE))
322 				return (YES);
323 			break;
324 		case TTY_TYPE:
325 			if (!strncmp(step->name, bp->ut_line, UT_LINESIZE))
326 				return (YES);
327 			break;
328 		case USER_TYPE:
329 			if (!strncmp(step->name, bp->ut_name, UT_NAMESIZE))
330 				return (YES);
331 			break;
332 	}
333 	return (NO);
334 }
335 
336 /*
337  * addarg --
338  *	add an entry to a linked list of arguments
339  */
340 void
341 addarg(type, arg)
342 	int type;
343 	char *arg;
344 {
345 	ARG *cur;
346 
347 	if (!(cur = (ARG *)malloc((u_int)sizeof(ARG))))
348 		err(1, "malloc failure");
349 	cur->next = arglist;
350 	cur->type = type;
351 	cur->name = arg;
352 	arglist = cur;
353 }
354 
355 /*
356  * hostconv --
357  *	convert the hostname to search pattern; if the supplied host name
358  *	has a domain attached that is the same as the current domain, rip
359  *	off the domain suffix since that's what login(1) does.
360  */
361 void
362 hostconv(arg)
363 	char *arg;
364 {
365 	static int first = 1;
366 	static char *hostdot, name[MAXHOSTNAMELEN];
367 	char *argdot;
368 
369 	if (!(argdot = strchr(arg, '.')))
370 		return;
371 	if (first) {
372 		first = 0;
373 		if (gethostname(name, sizeof(name)))
374 			err(1, "gethostname");
375 		hostdot = strchr(name, '.');
376 	}
377 	if (hostdot && !strcasecmp(hostdot, argdot))
378 		*argdot = '\0';
379 }
380 
381 /*
382  * ttyconv --
383  *	convert tty to correct name.
384  */
385 char *
386 ttyconv(arg)
387 	char *arg;
388 {
389 	char *mval;
390 
391 	/*
392 	 * kludge -- we assume that all tty's end with
393 	 * a two character suffix.
394 	 */
395 	if (strlen(arg) == 2) {
396 		/* either 6 for "ttyxx" or 8 for "console" */
397 		if (!(mval = malloc((u_int)8)))
398 			err(1, "malloc failure");
399 		if (!strcmp(arg, "co"))
400 			(void)strcpy(mval, "console");
401 		else {
402 			(void)strcpy(mval, "tty");
403 			(void)strcpy(mval + 3, arg);
404 		}
405 		return (mval);
406 	}
407 	if (!strncmp(arg, _PATH_DEV, sizeof(_PATH_DEV) - 1))
408 		return (arg + 5);
409 	return (arg);
410 }
411 
412 /*
413  * onintr --
414  *	on interrupt, we inform the user how far we've gotten
415  */
416 void
417 onintr(signo)
418 	int signo;
419 {
420 	char ct[80];
421 	struct tm *tm;
422 
423 	tm = localtime(&buf[0].ut_time);
424 	(void) strftime(ct, sizeof(ct), "%c", tm);
425 	printf("\ninterrupted %10.10s %5.5s \n", ct, ct + 11);
426 	if (signo == SIGINT)
427 		exit(1);
428 	(void)fflush(stdout);			/* fix required for rsh */
429 }
430