utils.h

/* fuse-overlayfs: Overlay Filesystem in Userspace

   Copyright (C) 2019 Red Hat Inc.

   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef UTILS_H
#define UTILS_H

#ifndef _GNU_SOURCE
#  define _GNU_SOURCE
#endif

#include <config.h>
#include <dirent.h>
#include <fcntl.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <unistd.h>
#include "fuse-overlayfs.h"

#define XATTR_OVERRIDE_STAT "user.fuseoverlayfs.override_stat"
#define XATTR_PRIVILEGED_OVERRIDE_STAT "security.fuseoverlayfs.override_stat"
#define XATTR_OVERRIDE_CONTAINERS_STAT "user.containers.override_stat"

void cleanup_freep (void *p);
void cleanup_filep (FILE **f);
void cleanup_closep (void *p);
void cleanup_dirp (DIR **p);

int file_exists_at (int dirfd, const char *pathname);

int strconcat3 (char *dest, size_t size, const char *s1, const char *s2, const char *s3);
int open_fd_or_get_path (struct ovl_layer *l, const char *path, char *out, int *fd, int flags);

#define cleanup_file __attribute__ ((cleanup (cleanup_filep)))
#define cleanup_free __attribute__ ((cleanup (cleanup_freep)))
#define cleanup_close __attribute__ ((cleanup (cleanup_closep)))
#define cleanup_dir __attribute__ ((cleanup (cleanup_dirp)))

#define LIKELY(x) __builtin_expect ((x), 1)
#define UNLIKELY(x) __builtin_expect ((x), 0)

#ifdef HAVE_STATX
void statx_to_stat (struct statx *stx, struct stat *st);
#endif

int safe_openat (int dirfd, const char *pathname, int flags, mode_t mode);

int override_mode (struct ovl_layer *l, int fd, const char *abs_path, const char *path, struct stat *st);

#endif