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/*
* Copyright (C) 2015 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 <sys/stat.h>
#include <sys/types.h>
#include <sys/xattr.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
extern "C" int ___fsetxattr(int, const char*, const void*, size_t, int);
int fsetxattr(int fd, const char* name, const void* value, size_t size, int flags) {
int saved_errno = errno;
int result = ___fsetxattr(fd, name, value, size, flags);
if ((result == 0) || (errno != EBADF)) {
return result;
}
// fd could be an O_PATH file descriptor, and the kernel
// may not directly support fsetxattr() on such a file descriptor.
// Use /proc/self/fd instead to emulate this support.
int fd_flag = fcntl(fd, F_GETFL);
if ((fd_flag == -1) || ((fd_flag & O_PATH) == 0)) {
errno = EBADF;
return -1;
}
char buf[40];
snprintf(buf, sizeof(buf), "/proc/self/fd/%d", fd);
errno = saved_errno;
return setxattr(buf, name, value, size, flags);
}
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