summaryrefslogtreecommitdiff
path: root/include/util/util.h
blob: a1330672b1585772ac9943c396fcd70fac572c5f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
/* SPDX-License-Identifier: LGPL-3.0-or-later */
/*
 * util.h
 *
 * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
 */
#ifndef UTIL_H
#define UTIL_H

#include "config.h"
#include "sqfs/predef.h"

#include <stdint.h>
#include <stddef.h>

#include "compat.h"

#define container_of(ptr, type, member) \
	((type *)((char *)ptr - offsetof(type, member)))

/*
  Helper for allocating data structures with flexible array members.

  'base_size' is the size of the struct itself, 'item_size' the size of a
  single array element and 'nmemb' the number of elements.

  Iternally checks for arithmetic overflows when allocating the combined thing.
 */
SQFS_INTERNAL
void *alloc_flex(size_t base_size, size_t item_size, size_t nmemb);

/* Basically the same as calloc, but *ALWAYS* does overflow checking */
SQFS_INTERNAL
void *alloc_array(size_t item_size, size_t nmemb);

/*
  Convert back to forward slashed, remove all preceeding and trailing slashes,
  collapse all sequences of slashes, remove all path components that are '.'
  and returns failure state if one of the path components is '..'.

  Returns 0 on success.
*/
SQFS_INTERNAL int canonicalize_name(char *filename);

#endif /* UTIL_H */