1 /* $OpenBSD: lockspool.c,v 1.11 2005/04/13 02:33:09 deraadt Exp $ */
2
3 /*
4 * Copyright (c) 1998 Theo de Raadt <deraadt@theos.com>
5 * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
6 * 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 *
17 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
18 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
19 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
20 * THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
21 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
22 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
23 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
24 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
25 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
26 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29 #ifndef lint
30 static const char rcsid[] = "$OpenBSD: lockspool.c,v 1.11 2005/04/13 02:33:09 deraadt Exp $";
31 #endif /* not lint */
32
33 #include <sys/signal.h>
34 #include <pwd.h>
35 #include <syslog.h>
36 #include <unistd.h>
37 #include <errno.h>
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include "mail.local.h"
41
42 void unhold(int);
43 void usage(void);
44
45 extern char *__progname;
46
47 int
main(int argc,char * argv[])48 main(int argc, char *argv[])
49 {
50 struct passwd *pw;
51 char *from, c;
52 int holdfd;
53
54 openlog(__progname, LOG_PERROR, LOG_MAIL);
55
56 if (argc != 1 && argc != 2)
57 usage();
58 if (argc == 2 && getuid() != 0)
59 merr(FATAL, "you must be root to lock someone else's spool");
60
61 signal(SIGTERM, unhold);
62 signal(SIGINT, unhold);
63 signal(SIGHUP, unhold);
64 signal(SIGPIPE, unhold);
65
66 if (argc == 2)
67 from = argv[1];
68 else
69 from = getlogin();
70
71 if (from) {
72 pw = getpwnam(from);
73 if (pw == NULL)
74 exit (1);
75 } else {
76 pw = getpwuid(getuid());
77 if (pw)
78 from = pw->pw_name;
79 else
80 exit (1);
81 }
82
83 holdfd = getlock(from, pw);
84 if (holdfd == -1) {
85 write(STDOUT_FILENO, "0\n", 2);
86 exit (1);
87 }
88 write(STDOUT_FILENO, "1\n", 2);
89
90 while (read(STDIN_FILENO, &c, 1) == -1 && errno == EINTR)
91 ;
92 rellock();
93 exit (0);
94 }
95
96 void
unhold(int signo)97 unhold(int signo)
98 {
99
100 rellock();
101 _exit(0);
102 }
103
104 void
usage(void)105 usage(void)
106 {
107
108 merr(FATAL, "usage: %s [username]", __progname);
109 }
110