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
31 #pragma ident "%Z%%M% %I% %E% SMI"
32
33 #include <stdio.h>
34 #include <signal.h>
35 #include <fcntl.h>
36 #include <unistd.h> /* alarm() */
37
38 #define S_WAITTIME 15
39
40 static struct flock flock = {
41 0, /* l_type */
42 0, /* l_whence */
43 0, /* l_start */
44 0, /* l_len */
45 0, /* l_sysid */
46 0 /* l_pid */
47 };
48
49 /*
50 * yplckpwdf() returns a 0 for a successful lock within W_WAITTIME
51 * and -1 otherwise
52 */
53
54 static int fildes = -1;
55 extern char lockfile[];
56
57 /* ARGSUSED */
58 static void
almhdlr(int sig)59 almhdlr(int sig)
60 {
61 }
62
63 int
yplckpwdf()64 yplckpwdf()
65 {
66 int retval;
67 if ((fildes = creat(lockfile, 0600)) == -1)
68 return (-1);
69
70 flock.l_type = F_WRLCK;
71 (void) sigset(SIGALRM, almhdlr);
72 (void) alarm(S_WAITTIME);
73 retval = fcntl(fildes, F_SETLKW, (int)&flock);
74 (void) alarm(0);
75 (void) sigset(SIGALRM, SIG_DFL);
76 return (retval);
77
78 }
79
80 /*
81 * ypulckpwdf() returns 0 for a successful unlock and -1 otherwise
82 */
83 int
ypulckpwdf()84 ypulckpwdf()
85 {
86 if (fildes == -1)
87 return (-1);
88
89 flock.l_type = F_UNLCK;
90 (void) fcntl(fildes, F_SETLK, (int)&flock);
91 (void) close(fildes);
92 fildes = -1;
93 return (0);
94
95 }
96