logwtmp.c revision 16433 
1/*
2 * Copyright (c) 1988, 1993
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
35#ifndef lint
36static char sccsid[] = "@(#)logwtmp.c	8.1 (Berkeley) 6/4/93";
37#endif /* not lint */
38
39#include <sys/types.h>
40#include <sys/stat.h>
41#include <netinet/in.h>
42#include <arpa/inet.h>
43
44#include <fcntl.h>
45#include <time.h>
46#include <netdb.h>
47#include <utmp.h>
48#include <unistd.h>
49#include <stdio.h>
50#include <string.h>
51#include "extern.h"
52
53static int fd = -1;
54
55/*
56 * Modified version of logwtmp that holds wtmp file open
57 * after first call, for use with ftp (which may chroot
58 * after login, but before logout).
59 */
60void
61logwtmp(line, name, host)
62	char *line, *name, *host;
63{
64	struct utmp ut;
65	struct stat buf;
66
67	if (strlen(host) > UT_HOSTSIZE) {
68		struct hostent *hp = gethostbyname(host);
69
70		if (hp != NULL) {
71			struct in_addr in;
72
73			memmove(&in, hp->h_addr, sizeof(in));
74			host = inet_ntoa(in);
75		} else
76			host = "invalid hostname";
77	}
78
79	if (fd < 0 && (fd = open(_PATH_WTMP, O_WRONLY|O_APPEND, 0)) < 0)
80		return;
81	if (fstat(fd, &buf) == 0) {
82		(void)strncpy(ut.ut_line, line, sizeof(ut.ut_line));
83		(void)strncpy(ut.ut_name, name, sizeof(ut.ut_name));
84		(void)strncpy(ut.ut_host, host, sizeof(ut.ut_host));
85		(void)time(&ut.ut_time);
86		if (write(fd, (char *)&ut, sizeof(struct utmp)) !=
87		    sizeof(struct utmp))
88			(void)ftruncate(fd, buf.st_size);
89	}
90}
91