xref: /openbsd-src/lib/libutil/logout.c (revision df69c215c7c66baf660f3f65414fd34796c96152)
1*df69c215Sderaadt /*	$OpenBSD: logout.c,v 1.10 2019/06/28 13:32:43 deraadt Exp $	*/
2df930be7Sderaadt /*
3df930be7Sderaadt  * Copyright (c) 1988, 1993
4df930be7Sderaadt  *	The Regents of the University of California.  All rights reserved.
5df930be7Sderaadt  *
6df930be7Sderaadt  * Redistribution and use in source and binary forms, with or without
7df930be7Sderaadt  * modification, are permitted provided that the following conditions
8df930be7Sderaadt  * are met:
9df930be7Sderaadt  * 1. Redistributions of source code must retain the above copyright
10df930be7Sderaadt  *    notice, this list of conditions and the following disclaimer.
11df930be7Sderaadt  * 2. Redistributions in binary form must reproduce the above copyright
12df930be7Sderaadt  *    notice, this list of conditions and the following disclaimer in the
13df930be7Sderaadt  *    documentation and/or other materials provided with the distribution.
146580fee3Smillert  * 3. Neither the name of the University nor the names of its contributors
15df930be7Sderaadt  *    may be used to endorse or promote products derived from this software
16df930be7Sderaadt  *    without specific prior written permission.
17df930be7Sderaadt  *
18df930be7Sderaadt  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19df930be7Sderaadt  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20df930be7Sderaadt  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21df930be7Sderaadt  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22df930be7Sderaadt  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23df930be7Sderaadt  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24df930be7Sderaadt  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25df930be7Sderaadt  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26df930be7Sderaadt  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27df930be7Sderaadt  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28df930be7Sderaadt  * SUCH DAMAGE.
29df930be7Sderaadt  */
30df930be7Sderaadt 
31df930be7Sderaadt #include <sys/types.h>
32df930be7Sderaadt #include <sys/time.h>
33df930be7Sderaadt 
34df930be7Sderaadt #include <fcntl.h>
35df930be7Sderaadt #include <utmp.h>
36df930be7Sderaadt #include <unistd.h>
37df930be7Sderaadt #include <stdlib.h>
38df930be7Sderaadt #include <string.h>
39ad69070aSdownsj 
40ad69070aSdownsj #include "util.h"
41df930be7Sderaadt 
42df930be7Sderaadt typedef struct utmp UTMP;
43df930be7Sderaadt 
44df930be7Sderaadt int
logout(const char * line)451477552aSderaadt logout(const char *line)
46df930be7Sderaadt {
474b826ba8Sderaadt 	int fd, rval;
48df930be7Sderaadt 	UTMP ut;
49df930be7Sderaadt 
50*df69c215Sderaadt 	if ((fd = open(_PATH_UTMP, O_RDWR|O_CLOEXEC)) == -1)
51df930be7Sderaadt 		return(0);
52df930be7Sderaadt 	rval = 0;
53df930be7Sderaadt 	while (read(fd, &ut, sizeof(UTMP)) == sizeof(UTMP)) {
54df930be7Sderaadt 		if (!ut.ut_name[0] || strncmp(ut.ut_line, line, UT_LINESIZE))
55df930be7Sderaadt 			continue;
5627c829c3Sguenther 		memset(ut.ut_name, 0, UT_NAMESIZE);
5727c829c3Sguenther 		memset(ut.ut_host, 0, UT_HOSTSIZE);
58df930be7Sderaadt 		(void)time(&ut.ut_time);
59fb045e09Smillert 		(void)lseek(fd, -(off_t)sizeof(UTMP), SEEK_CUR);
60df930be7Sderaadt 		(void)write(fd, &ut, sizeof(UTMP));
61df930be7Sderaadt 		rval = 1;
62df930be7Sderaadt 	}
63df930be7Sderaadt 	(void)close(fd);
64df930be7Sderaadt 	return(rval);
65df930be7Sderaadt }
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