1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License, Version 1.0 only
6 * (the "License"). You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22 /*
23 * Copyright (c) 1996-2001 by Sun Microsystems, Inc.
24 * All rights reserved.
25 */
26
27 /* Copyright (c) 1988 AT&T */
28 /* All Rights Reserved */
29
30 #include <stdio.h>
31 #include <signal.h>
32 #include <fcntl.h>
33 #include <unistd.h> /* alarm() */
34
35 #define S_WAITTIME 15
36
37 static struct flock flock = {
38 0, /* l_type */
39 0, /* l_whence */
40 0, /* l_start */
41 0, /* l_len */
42 0, /* l_sysid */
43 0 /* l_pid */
44 };
45
46 /*
47 * yplckpwdf() returns a 0 for a successful lock within W_WAITTIME
48 * and -1 otherwise
49 */
50
51 static int fildes = -1;
52 extern char lockfile[];
53
54 /* ARGSUSED */
55 static void
almhdlr(int sig)56 almhdlr(int sig)
57 {
58 }
59
60 int
yplckpwdf()61 yplckpwdf()
62 {
63 int retval;
64 if ((fildes = creat(lockfile, 0600)) == -1)
65 return (-1);
66
67 flock.l_type = F_WRLCK;
68 (void) sigset(SIGALRM, almhdlr);
69 (void) alarm(S_WAITTIME);
70 retval = fcntl(fildes, F_SETLKW, (int)&flock);
71 (void) alarm(0);
72 (void) sigset(SIGALRM, SIG_DFL);
73 return (retval);
74
75 }
76
77 /*
78 * ypulckpwdf() returns 0 for a successful unlock and -1 otherwise
79 */
80 int
ypulckpwdf()81 ypulckpwdf()
82 {
83 if (fildes == -1)
84 return (-1);
85
86 flock.l_type = F_UNLCK;
87 (void) fcntl(fildes, F_SETLK, (int)&flock);
88 (void) close(fildes);
89 fildes = -1;
90 return (0);
91
92 }
93