1/*	$OpenBSD: logout.c,v 1.10 2019/06/28 13:32:43 deraadt Exp $	*/
2/*
3 * Copyright (c) 1988, 1993
4 *	The Regents of the University of California.  All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 * 3. Neither the name of the University nor the names of its contributors
15 *    may be used to endorse or promote products derived from this software
16 *    without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31#include <sys/types.h>
32#include <sys/time.h>
33
34#include <fcntl.h>
35#include <utmp.h>
36#include <unistd.h>
37#include <stdlib.h>
38#include <string.h>
39
40#include "util.h"
41
42typedef struct utmp UTMP;
43
44int
45logout(const char *line)
46{
47	int fd, rval;
48	UTMP ut;
49
50	if ((fd = open(_PATH_UTMP, O_RDWR|O_CLOEXEC)) == -1)
51		return(0);
52	rval = 0;
53	while (read(fd, &ut, sizeof(UTMP)) == sizeof(UTMP)) {
54		if (!ut.ut_name[0] || strncmp(ut.ut_line, line, UT_LINESIZE))
55			continue;
56		memset(ut.ut_name, 0, UT_NAMESIZE);
57		memset(ut.ut_host, 0, UT_HOSTSIZE);
58		(void)time(&ut.ut_time);
59		(void)lseek(fd, -(off_t)sizeof(UTMP), SEEK_CUR);
60		(void)write(fd, &ut, sizeof(UTMP));
61		rval = 1;
62	}
63	(void)close(fd);
64	return(rval);
65}
66