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 returning 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