1/*
2 * Copyright (c) 2014-2020 Pavel Kalvoda <me@pavelkalvoda.com>
3 *
4 * libcbor is free software; you can redistribute it and/or modify
5 * it under the terms of the MIT license. See LICENSE for details.
6 */
7
8#ifndef LIBCBOR_MEMORY_UTILS_H
9#define LIBCBOR_MEMORY_UTILS_H
10
11#include <stdbool.h>
12#include <string.h>
13
14#include "cbor/common.h"
15
16/** Can `a` and `b` be multiplied without overflowing size_t? */
17_CBOR_NODISCARD
18bool _cbor_safe_to_multiply(size_t a, size_t b);
19
20/** Can `a` and `b` be added without overflowing size_t? */
21_CBOR_NODISCARD
22bool _cbor_safe_to_add(size_t a, size_t b);
23
24/** Adds `a` and `b`, propagating zeros and returing 0 on overflow. */
25_CBOR_NODISCARD
26size_t _cbor_safe_signaling_add(size_t a, size_t b);
27
28/** Overflow-proof contiguous array allocation
29 *
30 * @param item_size
31 * @param item_count
32 * @return Region of item_size * item_count bytes, or NULL if the total size
33 * overflows size_t or the underlying allocator failed
34 */
35void* _cbor_alloc_multiple(size_t item_size, size_t item_count);
36
37/** Overflow-proof contiguous array reallocation
38 *
39 * This implements the OpenBSD `reallocarray` functionality.
40 *
41 * @param pointer
42 * @param item_size
43 * @param item_count
44 * @return Realloc'd of item_size * item_count bytes, or NULL if the total size
45 * overflows size_t or the underlying allocator failed
46 */
47void* _cbor_realloc_multiple(void* pointer, size_t item_size,
48                             size_t item_count);
49
50#endif  // LIBCBOR_MEMORY_UTILS_H
51