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/*
* Copyright (C) 2016 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>
#include <string.h>
int lockf64(int fd, int cmd, off64_t length) {
// Translate POSIX lockf into fcntl.
struct flock64 fl;
memset(&fl, 0, sizeof(fl));
fl.l_whence = SEEK_CUR;
fl.l_start = 0;
fl.l_len = length;
if (cmd == F_ULOCK) {
fl.l_type = F_UNLCK;
cmd = F_SETLK64;
return fcntl(fd, F_SETLK64, &fl);
}
if (cmd == F_LOCK) {
fl.l_type = F_WRLCK;
return fcntl(fd, F_SETLKW64, &fl);
}
if (cmd == F_TLOCK) {
fl.l_type = F_WRLCK;
return fcntl(fd, F_SETLK64, &fl);
}
if (cmd == F_TEST) {
fl.l_type = F_RDLCK;
if (fcntl(fd, F_GETLK64, &fl) == -1) return -1;
if (fl.l_type == F_UNLCK || fl.l_pid == getpid()) return 0;
errno = EACCES;
return -1;
}
errno = EINVAL;
return -1;
}
int lockf(int fd, int cmd, off_t length) {
return lockf64(fd, cmd, length);
}
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