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