xref: /openbsd/libexec/ftpd/logwtmp.c (revision d415bd75)
1 /*	$OpenBSD: logwtmp.c,v 1.14 2021/10/24 21:24:20 deraadt Exp $	*/
2 /*	$NetBSD: logwtmp.c,v 1.4 1995/04/11 02:44:58 cgd Exp $	*/
3 
4 /*
5  * Copyright (c) 1988, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  *
32  */
33 
34 #include <sys/types.h>
35 #include <sys/time.h>
36 #include <sys/stat.h>
37 
38 #include <fcntl.h>
39 #include <utmp.h>
40 #include <unistd.h>
41 #include <stdio.h>
42 #include <string.h>
43 
44 #include <netinet/in.h>
45 
46 #include "monitor.h"
47 #include "extern.h"
48 
49 static int fd = -1;
50 
51 /*
52  * Modified version of logwtmp that holds wtmp file open
53  * after first call, for use with ftp (which may chroot
54  * after login, but before logout).
55  */
56 void
57 ftpdlogwtmp(const char *line, const char *name, const char *host)
58 {
59 	struct timeval tv;
60 	struct stat buf;
61 	struct utmp ut;
62 
63 	if (fd < 0 && (fd = open(_PATH_WTMP, O_WRONLY|O_APPEND)) == -1)
64 		return;
65 	if (fstat(fd, &buf) == 0) {
66 		(void)strncpy(ut.ut_line, line, sizeof(ut.ut_line));
67 		(void)strncpy(ut.ut_name, name, sizeof(ut.ut_name));
68 		(void)strncpy(ut.ut_host, host, sizeof(ut.ut_host));
69 		gettimeofday(&tv, NULL);
70 		ut.ut_time = tv.tv_sec;
71 		if (write(fd, (char *)&ut, sizeof(struct utmp)) !=
72 		    sizeof(struct utmp))
73 			(void)ftruncate(fd, buf.st_size);
74 	}
75 }
76