xref: /netbsd-src/libexec/ftpd/logutmp.c (revision 21e37cc72a480a47828990a439cde7ac9ffaf0c6)
1 /*
2  * Portions 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. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 /*
31  * Portions Copyright (c) 1996, Jason Downs.  All rights reserved.
32  *
33  * Redistribution and use in source and binary forms, with or without
34  * modification, are permitted provided that the following conditions
35  * are met:
36  * 1. Redistributions of source code must retain the above copyright
37  *    notice, this list of conditions and the following disclaimer.
38  * 2. Redistributions in binary form must reproduce the above copyright
39  *    notice, this list of conditions and the following disclaimer in the
40  *    documentation and/or other materials provided with the distribution.
41  *
42  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS
43  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
44  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
45  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT,
46  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
47  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
48  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
49  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
50  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
51  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
52  * SUCH DAMAGE.
53  */
54 
55 #include <sys/types.h>
56 #include <sys/param.h>
57 
58 #include <fcntl.h>
59 #include <setjmp.h>
60 #include <stdio.h>
61 #include <stdlib.h>
62 #include <string.h>
63 #include <ttyent.h>
64 #include <unistd.h>
65 #include <utmp.h>
66 #ifdef SUPPORT_UTMPX
67 #include <utmpx.h>
68 #endif
69 #include <util.h>
70 
71 #include "extern.h"
72 
73 typedef struct utmp UTMP;
74 
75 static int fd = -1;
76 static int topslot = -1;
77 
78 /*
79  * Special versions of login()/logout() which hold the utmp file open,
80  * for use with ftpd.
81  */
82 
83 void
84 ftpd_login(const struct utmp *ut)
85 {
86 	UTMP ubuf;
87 
88 	/*
89 	 * First, loop through /etc/ttys, if needed, to initialize the
90 	 * top of the tty slots, since ftpd has no tty.
91 	 */
92 	if (topslot < 0) {
93 		topslot = 0;
94 		while (getttyent() != (struct ttyent *)NULL)
95 			topslot++;
96 	}
97 	if ((topslot < 0) || ((fd < 0)
98 	    && (fd = open(_PATH_UTMP, O_RDWR|O_CREAT, 0644)) < 0))
99 		return;
100 
101 	/*
102 	 * Now find a slot that's not in use...
103 	 */
104 	(void)lseek(fd, (off_t)(topslot * sizeof(UTMP)), SEEK_SET);
105 
106 	while (1) {
107 		if (read(fd, &ubuf, sizeof(UTMP)) == sizeof(UTMP)) {
108 			if (!ubuf.ut_name[0]) {
109 				(void)lseek(fd, -(off_t)sizeof(UTMP), SEEK_CUR);
110 				break;
111 			}
112 			topslot++;
113 		} else {
114 			(void)lseek(fd, (off_t)(topslot * sizeof(UTMP)),
115 			    SEEK_SET);
116 			break;
117 		}
118 	}
119 
120 	(void)write(fd, ut, sizeof(UTMP));
121 }
122 
123 int
124 ftpd_logout(const char *line)
125 {
126 	UTMP ut;
127 	int rval;
128 
129 	rval = 0;
130 	if (fd < 0)
131 		return(rval);
132 
133 	(void)lseek(fd, 0, SEEK_SET);
134 
135 	while (read(fd, &ut, sizeof(UTMP)) == sizeof(UTMP)) {
136 		if (!ut.ut_name[0]
137 		    || strncmp(ut.ut_line, line, UT_LINESIZE))
138 			continue;
139 		memset(ut.ut_name, 0, UT_NAMESIZE);
140 		memset(ut.ut_host, 0, UT_HOSTSIZE);
141 		(void)time(&ut.ut_time);
142 		(void)lseek(fd, -(off_t)sizeof(UTMP), SEEK_CUR);
143 		(void)write(fd, &ut, sizeof(UTMP));
144 		rval = 1;
145 	}
146 	return(rval);
147 }
148 
149 #ifdef SUPPORT_UTMPX
150 /*
151  * special version of loginx which updates utmpx only.
152  */
153 void
154 ftpd_loginx(const struct utmpx *ut)
155 {
156 	(void)pututxline(ut);
157 }
158 #endif
159