xref: /freebsd/usr.bin/last/last.c (revision 953a3198a35204535cc9d450f04da982a4fea59b)
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 <paths.h>
50 #include <signal.h>
51 #include <stdio.h>
52 #include <stdlib.h>
53 #include <string.h>
54 #include <time.h>
55 #include <unistd.h>
56 #include <utmp.h>
57 
58 #define	NO	0				/* false/no */
59 #define	YES	1				/* true/yes */
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 typedef struct ttytab {
74 	long	logout;				/* log out time */
75 	char	tty[UT_LINESIZE + 1];		/* terminal name */
76 	struct ttytab	*next;			/* linked list pointer */
77 } TTY;
78 TTY	*ttylist;				/* head of linked list */
79 
80 static long	currentout,			/* current logout value */
81 		maxrec;				/* records to display */
82 static char	*file = _PATH_WTMP;		/* wtmp file */
83 
84 void	 addarg __P((int, char *));
85 TTY	*addtty __P((char *));
86 void	 hostconv __P((char *));
87 void	 onintr __P((int));
88 char	*ttyconv __P((char *));
89 int	 want __P((struct utmp *, int));
90 void	 wtmp __P((void));
91 
92 int
93 main(argc, argv)
94 	int argc;
95 	char *argv[];
96 {
97 	extern int optind;
98 	extern char *optarg;
99 	int ch;
100 	char *p;
101 
102 	maxrec = -1;
103 	while ((ch = getopt(argc, argv, "0123456789f:h:t:")) != EOF)
104 		switch (ch) {
105 		case '0': case '1': case '2': case '3': case '4':
106 		case '5': case '6': case '7': case '8': case '9':
107 			/*
108 			 * kludge: last was originally designed to take
109 			 * a number after a dash.
110 			 */
111 			if (maxrec == -1) {
112 				p = argv[optind - 1];
113 				if (p[0] == '-' && p[1] == ch && !p[2])
114 					maxrec = atol(++p);
115 				else
116 					maxrec = atol(argv[optind] + 1);
117 				if (!maxrec)
118 					exit(0);
119 			}
120 			break;
121 		case 'f':
122 			file = optarg;
123 			break;
124 		case 'h':
125 			hostconv(optarg);
126 			addarg(HOST_TYPE, optarg);
127 			break;
128 		case 't':
129 			addarg(TTY_TYPE, ttyconv(optarg));
130 			break;
131 		case '?':
132 		default:
133 			(void)fprintf(stderr,
134 	"usage: last [-#] [-f file] [-t tty] [-h hostname] [user ...]\n");
135 			exit(1);
136 		}
137 
138 	if (argc) {
139 		setlinebuf(stdout);
140 		for (argv += optind; *argv; ++argv) {
141 #define	COMPATIBILITY
142 #ifdef	COMPATIBILITY
143 			/* code to allow "last p5" to work */
144 			addarg(TTY_TYPE, ttyconv(*argv));
145 #endif
146 			addarg(USER_TYPE, *argv);
147 		}
148 	}
149 	wtmp();
150 	exit(0);
151 }
152 
153 /*
154  * wtmp --
155  *	read through the wtmp file
156  */
157 void
158 wtmp()
159 {
160 	struct utmp	*bp;			/* current structure */
161 	TTY	*T;				/* tty list entry */
162 	struct stat	stb;			/* stat of file for size */
163 	long	bl, delta;			/* time difference */
164 	int	bytes, wfd;
165 	char	*ct, *crmsg;
166 
167 	if ((wfd = open(file, O_RDONLY, 0)) < 0 || fstat(wfd, &stb) == -1)
168 		err(1, "%s", file);
169 	bl = (stb.st_size + sizeof(buf) - 1) / sizeof(buf);
170 
171 	(void)time(&buf[0].ut_time);
172 	(void)signal(SIGINT, onintr);
173 	(void)signal(SIGQUIT, onintr);
174 
175 	while (--bl >= 0) {
176 		if (lseek(wfd, (off_t)(bl * sizeof(buf)), L_SET) == -1 ||
177 		    (bytes = read(wfd, buf, sizeof(buf))) == -1)
178 			err(1, "%s", file);
179 		for (bp = &buf[bytes / sizeof(buf[0]) - 1]; bp >= buf; --bp) {
180 			/*
181 			 * if the terminal line is '~', the machine stopped.
182 			 * see utmp(5) for more info.
183 			 */
184 			if (bp->ut_line[0] == '~' && !bp->ut_line[1]) {
185 				/* everybody just logged out */
186 				for (T = ttylist; T; T = T->next)
187 					T->logout = -bp->ut_time;
188 				currentout = -bp->ut_time;
189 				crmsg = strncmp(bp->ut_name, "shutdown",
190 				    UT_NAMESIZE) ? "crash" : "shutdown";
191 				if (want(bp, NO)) {
192 					ct = ctime(&bp->ut_time);
193 				printf("%-*.*s  %-*.*s %-*.*s %10.10s %5.5s \n",
194 					    UT_NAMESIZE, UT_NAMESIZE,
195 					    bp->ut_name, UT_LINESIZE,
196 					    UT_LINESIZE, bp->ut_line,
197 					    UT_HOSTSIZE, UT_HOSTSIZE,
198 					    bp->ut_host, ct, ct + 11);
199 					if (maxrec != -1 && !--maxrec)
200 						return;
201 				}
202 				continue;
203 			}
204 			/*
205 			 * if the line is '{' or '|', date got set; see
206 			 * utmp(5) for more info.
207 			 */
208 			if ((bp->ut_line[0] == '{' || bp->ut_line[0] == '|')
209 			    && !bp->ut_line[1]) {
210 				if (want(bp, NO)) {
211 					ct = ctime(&bp->ut_time);
212 				printf("%-*.*s  %-*.*s %-*.*s %10.10s %5.5s \n",
213 				    UT_NAMESIZE, UT_NAMESIZE, bp->ut_name,
214 				    UT_LINESIZE, UT_LINESIZE, bp->ut_line,
215 				    UT_HOSTSIZE, UT_HOSTSIZE, bp->ut_host,
216 				    ct, ct + 11);
217 					if (maxrec && !--maxrec)
218 						return;
219 				}
220 				continue;
221 			}
222 			/* find associated tty */
223 			for (T = ttylist;; T = T->next) {
224 				if (!T) {
225 					/* add new one */
226 					T = addtty(bp->ut_line);
227 					break;
228 				}
229 				if (!strncmp(T->tty, bp->ut_line, UT_LINESIZE))
230 					break;
231 			}
232 			if (bp->ut_name[0] && want(bp, YES)) {
233 				ct = ctime(&bp->ut_time);
234 				printf("%-*.*s  %-*.*s %-*.*s %10.10s %5.5s ",
235 				UT_NAMESIZE, UT_NAMESIZE, bp->ut_name,
236 				UT_LINESIZE, UT_LINESIZE, bp->ut_line,
237 				UT_HOSTSIZE, UT_HOSTSIZE, bp->ut_host,
238 				ct, ct + 11);
239 				if (!T->logout)
240 					puts("  still logged in");
241 				else {
242 					if (T->logout < 0) {
243 						T->logout = -T->logout;
244 						printf("- %s", crmsg);
245 					}
246 					else
247 						printf("- %5.5s",
248 						    ctime(&T->logout)+11);
249 					delta = T->logout - bp->ut_time;
250 					if (delta < 86400)
251 						printf("  (%5.5s)\n",
252 						    asctime(gmtime(&delta))+11);
253 					else
254 						printf(" (%ld+%5.5s)\n",
255 						    delta / 86400,
256 						    asctime(gmtime(&delta))+11);
257 				}
258 				if (maxrec != -1 && !--maxrec)
259 					return;
260 			}
261 			T->logout = bp->ut_time;
262 		}
263 	}
264 	ct = ctime(&buf[0].ut_time);
265 	printf("\nwtmp begins %10.10s %5.5s \n", ct, ct + 11);
266 }
267 
268 /*
269  * want --
270  *	see if want this entry
271  */
272 int
273 want(bp, check)
274 	struct utmp *bp;
275 	int check;
276 {
277 	ARG *step;
278 
279 	if (check)
280 		/*
281 		 * when uucp and ftp log in over a network, the entry in
282 		 * the utmp file is the name plus their process id.  See
283 		 * etc/ftpd.c and usr.bin/uucp/uucpd.c for more information.
284 		 */
285 		if (!strncmp(bp->ut_line, "ftp", sizeof("ftp") - 1))
286 			bp->ut_line[3] = '\0';
287 		else if (!strncmp(bp->ut_line, "uucp", sizeof("uucp") - 1))
288 			bp->ut_line[4] = '\0';
289 	if (!arglist)
290 		return (YES);
291 
292 	for (step = arglist; step; step = step->next)
293 		switch(step->type) {
294 		case HOST_TYPE:
295 			if (!strncasecmp(step->name, bp->ut_host, UT_HOSTSIZE))
296 				return (YES);
297 			break;
298 		case TTY_TYPE:
299 			if (!strncmp(step->name, bp->ut_line, UT_LINESIZE))
300 				return (YES);
301 			break;
302 		case USER_TYPE:
303 			if (!strncmp(step->name, bp->ut_name, UT_NAMESIZE))
304 				return (YES);
305 			break;
306 	}
307 	return (NO);
308 }
309 
310 /*
311  * addarg --
312  *	add an entry to a linked list of arguments
313  */
314 void
315 addarg(type, arg)
316 	int type;
317 	char *arg;
318 {
319 	ARG *cur;
320 
321 	if (!(cur = (ARG *)malloc((u_int)sizeof(ARG))))
322 		err(1, "malloc failure");
323 	cur->next = arglist;
324 	cur->type = type;
325 	cur->name = arg;
326 	arglist = cur;
327 }
328 
329 /*
330  * addtty --
331  *	add an entry to a linked list of ttys
332  */
333 TTY *
334 addtty(ttyname)
335 	char *ttyname;
336 {
337 	TTY *cur;
338 
339 	if (!(cur = (TTY *)malloc((u_int)sizeof(TTY))))
340 		err(1, "malloc failure");
341 	cur->next = ttylist;
342 	cur->logout = currentout;
343 	memmove(cur->tty, ttyname, UT_LINESIZE);
344 	return (ttylist = cur);
345 }
346 
347 /*
348  * hostconv --
349  *	convert the hostname to search pattern; if the supplied host name
350  *	has a domain attached that is the same as the current domain, rip
351  *	off the domain suffix since that's what login(1) does.
352  */
353 void
354 hostconv(arg)
355 	char *arg;
356 {
357 	static int first = 1;
358 	static char *hostdot, name[MAXHOSTNAMELEN];
359 	char *argdot;
360 
361 	if (!(argdot = strchr(arg, '.')))
362 		return;
363 	if (first) {
364 		first = 0;
365 		if (gethostname(name, sizeof(name)))
366 			err(1, "gethostname");
367 		hostdot = strchr(name, '.');
368 	}
369 	if (hostdot && !strcasecmp(hostdot, argdot))
370 		*argdot = '\0';
371 }
372 
373 /*
374  * ttyconv --
375  *	convert tty to correct name.
376  */
377 char *
378 ttyconv(arg)
379 	char *arg;
380 {
381 	char *mval;
382 
383 	/*
384 	 * kludge -- we assume that all tty's end with
385 	 * a two character suffix.
386 	 */
387 	if (strlen(arg) == 2) {
388 		/* either 6 for "ttyxx" or 8 for "console" */
389 		if (!(mval = malloc((u_int)8)))
390 			err(1, "malloc failure");
391 		if (!strcmp(arg, "co"))
392 			(void)strcpy(mval, "console");
393 		else {
394 			(void)strcpy(mval, "tty");
395 			(void)strcpy(mval + 3, arg);
396 		}
397 		return (mval);
398 	}
399 	if (!strncmp(arg, _PATH_DEV, sizeof(_PATH_DEV) - 1))
400 		return (arg + 5);
401 	return (arg);
402 }
403 
404 /*
405  * onintr --
406  *	on interrupt, we inform the user how far we've gotten
407  */
408 void
409 onintr(signo)
410 	int signo;
411 {
412 	char *ct;
413 
414 	ct = ctime(&buf[0].ut_time);
415 	printf("\ninterrupted %10.10s %5.5s \n", ct, ct + 11);
416 	if (signo == SIGINT)
417 		exit(1);
418 	(void)fflush(stdout);			/* fix required for rsh */
419 }
420