/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*      Copyright (c) 1988 AT&T */
/*        All Rights Reserved   */

#include <sys/feature_tests.h>

#if !defined(_LP64) && _FILE_OFFSET_BITS == 64
#define __lockf         __lockf64
#endif

#include "lint.h"
#include <sys/types.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>

int
__lockf(int fildes, int function, off_t size)
{
        struct flock l;
        int rv;

        l.l_whence = 1;
        if (size < 0) {
                l.l_start = size;
                l.l_len = -size;
        } else {
                l.l_start = (off_t)0;
                l.l_len = size;
        }
        switch (function) {
        case F_ULOCK:
                l.l_type = F_UNLCK;
                rv = fcntl(fildes, F_SETLK, &l);
                break;
        case F_LOCK:
                l.l_type = F_WRLCK;
                rv = fcntl(fildes, F_SETLKW, &l);
                break;
        case F_TLOCK:
                l.l_type = F_WRLCK;
                rv = fcntl(fildes, F_SETLK, &l);
                break;
        case F_TEST:
                l.l_type = F_WRLCK;
                rv = fcntl(fildes, F_GETLK, &l);
                if (rv != -1) {
                        if (l.l_type == F_UNLCK)
                                return (0);
                        else {
                                errno = EAGAIN;
                                return (-1);
                        }
                }
                break;
        default:
                errno = EINVAL;
                return (-1);
        }
        if (rv < 0) {
                switch (errno) {
                case EMFILE:
                case ENOSPC:
                case ENOLCK:
                        /*
                         * A deadlock error is given if we run out of resources,
                         * in compliance with /usr/group standards.
                         */
                        errno = EDEADLK;
                        break;
                default:
                        break;
                }
        }
        return (rv);
}