1/* $NetBSD: lockf.c,v 1.3 2008/04/28 20:22:59 martin Exp $ */ 2/*- 3 * SPDX-License-Identifier: BSD-2-Clause-NetBSD 4 * 5 * Copyright (c) 1997 The NetBSD Foundation, Inc. 6 * All rights reserved. 7 * 8 * This code is derived from software contributed to The NetBSD Foundation 9 * by Klaus Klein. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 30 * POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33#include <sys/cdefs.h> 34__FBSDID("$FreeBSD$"); 35 36#include "namespace.h" 37#include <errno.h> 38#include <fcntl.h> 39#include <unistd.h> 40#include "un-namespace.h" 41#include "libc_private.h" 42 43int 44lockf(int filedes, int function, off_t size) 45{ 46 struct flock fl; 47 int cmd; 48 49 fl.l_start = 0; 50 fl.l_len = size; 51 fl.l_whence = SEEK_CUR; 52 53 switch (function) { 54 case F_ULOCK: 55 cmd = F_SETLK; 56 fl.l_type = F_UNLCK; 57 break; 58 case F_LOCK: 59 cmd = F_SETLKW; 60 fl.l_type = F_WRLCK; 61 break; 62 case F_TLOCK: 63 cmd = F_SETLK; 64 fl.l_type = F_WRLCK; 65 break; 66 case F_TEST: 67 fl.l_type = F_WRLCK; 68 if (((int (*)(int, int, ...)) 69 __libc_interposing[INTERPOS_fcntl])(filedes, F_GETLK, &fl) 70 == -1) 71 return (-1); 72 if (fl.l_type == F_UNLCK || (fl.l_sysid == 0 && 73 fl.l_pid == getpid())) 74 return (0); 75 errno = EAGAIN; 76 return (-1); 77 /* NOTREACHED */ 78 default: 79 errno = EINVAL; 80 return (-1); 81 /* NOTREACHED */ 82 } 83 84 return (((int (*)(int, int, ...)) 85 __libc_interposing[INTERPOS_fcntl])(filedes, cmd, &fl)); 86} 87