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 59 almhdlr(int sig) 60 { 61 } 62 63 int 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 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