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
18 bool _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
22 bool _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
26 size_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  */
35 void* _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  */
47 void* _cbor_realloc_multiple(void* pointer, size_t item_size,
48                              size_t item_count);
49 
50 #endif  // LIBCBOR_MEMORY_UTILS_H
51