xref: /netbsd-src/libexec/ftpd/logutmp.c (revision d710132b4b8ce7f7cccaaf660cb16aa16b4077a0)
1 /*
2  * Portions Copyright (c) 1988, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  * Portions Copyright (c) 1996, Jason Downs.  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. All advertising materials mentioning features or use of this software
15  *    must display the following acknowledgement:
16  *	This product includes software developed by the University of
17  *	California, Berkeley and its contributors.
18  * 4. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #include <sys/types.h>
36 #include <sys/param.h>
37 
38 #include <fcntl.h>
39 #include <setjmp.h>
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <string.h>
43 #include <ttyent.h>
44 #include <unistd.h>
45 #include <utmp.h>
46 #include <util.h>
47 
48 #include "extern.h"
49 
50 typedef struct utmp UTMP;
51 
52 static int fd = -1;
53 static int topslot = -1;
54 
55 /*
56  * Special versions of login()/logout() which hold the utmp file open,
57  * for use with ftpd.
58  */
59 
60 void
61 ftpd_login(const struct utmp *ut)
62 {
63 	UTMP ubuf;
64 
65 	/*
66 	 * First, loop through /etc/ttys, if needed, to initialize the
67 	 * top of the tty slots, since ftpd has no tty.
68 	 */
69 	if (topslot < 0) {
70 		topslot = 0;
71 		while (getttyent() != (struct ttyent *)NULL)
72 			topslot++;
73 	}
74 	if ((topslot < 0) || ((fd < 0)
75 	    && (fd = open(_PATH_UTMP, O_RDWR|O_CREAT, 0644)) < 0))
76 		return;
77 
78 	/*
79 	 * Now find a slot that's not in use...
80 	 */
81 	(void)lseek(fd, (off_t)(topslot * sizeof(UTMP)), SEEK_SET);
82 
83 	while (1) {
84 		if (read(fd, &ubuf, sizeof(UTMP)) == sizeof(UTMP)) {
85 			if (!ubuf.ut_name[0]) {
86 				(void)lseek(fd, -(off_t)sizeof(UTMP), SEEK_CUR);
87 				break;
88 			}
89 			topslot++;
90 		} else {
91 			(void)lseek(fd, (off_t)(topslot * sizeof(UTMP)),
92 			    SEEK_SET);
93 			break;
94 		}
95 	}
96 
97 	(void)write(fd, ut, sizeof(UTMP));
98 }
99 
100 int
101 ftpd_logout(const char *line)
102 {
103 	UTMP ut;
104 	int rval;
105 
106 	rval = 0;
107 	if (fd < 0)
108 		return(rval);
109 
110 	(void)lseek(fd, 0, SEEK_SET);
111 
112 	while (read(fd, &ut, sizeof(UTMP)) == sizeof(UTMP)) {
113 		if (!ut.ut_name[0]
114 		    || strncmp(ut.ut_line, line, UT_LINESIZE))
115 			continue;
116 		memset(ut.ut_name, 0, UT_NAMESIZE);
117 		memset(ut.ut_host, 0, UT_HOSTSIZE);
118 		(void)time(&ut.ut_time);
119 		(void)lseek(fd, -(off_t)sizeof(UTMP), SEEK_CUR);
120 		(void)write(fd, &ut, sizeof(UTMP));
121 		rval = 1;
122 	}
123 	return(rval);
124 }
125