1 /* 2 * Copyright (c) 2016-2020, Facebook, Inc. 3 * All rights reserved. 4 * 5 * This source code is licensed under both the BSD-style license (found in the 6 * LICENSE file in the root directory of this source tree) and the GPLv2 (found 7 * in the COPYING file in the root directory of this source tree). 8 * You may select, at your option, one of the above-listed licenses. 9 */ 10 11 /** 12 * Helper APIs for generating random data from input data stream. 13 The producer reads bytes from the end of the input and appends them together 14 to generate a random number in the requested range. If it runs out of input 15 data, it will keep returning the same value (min) over and over again. 16 17 */ 18 19 #ifndef FUZZ_DATA_PRODUCER_H 20 #define FUZZ_DATA_PRODUCER_H 21 22 #include <stddef.h> 23 #include <stdint.h> 24 #include <stdio.h> 25 #include <stdlib.h> 26 27 #include "fuzz_helpers.h" 28 29 /* Struct used for maintaining the state of the data */ 30 typedef struct FUZZ_dataProducer_s FUZZ_dataProducer_t; 31 32 /* Returns a data producer state struct. Use for producer initialization. */ 33 FUZZ_dataProducer_t *FUZZ_dataProducer_create(const uint8_t *data, size_t size); 34 35 /* Frees the data producer */ 36 void FUZZ_dataProducer_free(FUZZ_dataProducer_t *producer); 37 38 /* Returns value between [min, max] */ 39 uint32_t FUZZ_dataProducer_uint32Range(FUZZ_dataProducer_t *producer, uint32_t min, 40 uint32_t max); 41 42 /* Returns a uint32 value */ 43 uint32_t FUZZ_dataProducer_uint32(FUZZ_dataProducer_t *producer); 44 45 /* Returns a signed value between [min, max] */ 46 int32_t FUZZ_dataProducer_int32Range(FUZZ_dataProducer_t *producer, 47 int32_t min, int32_t max); 48 49 /* Returns the size of the remaining bytes of data in the producer */ 50 size_t FUZZ_dataProducer_remainingBytes(FUZZ_dataProducer_t *producer); 51 52 /* Returns true if the data producer is out of bytes */ 53 int FUZZ_dataProducer_empty(FUZZ_dataProducer_t *producer); 54 55 /* Restricts the producer to only the last newSize bytes of data. 56 If newSize > current data size, nothing happens. Returns the number of bytes 57 the producer won't use anymore, after contracting. */ 58 size_t FUZZ_dataProducer_contract(FUZZ_dataProducer_t *producer, size_t newSize); 59 60 /* Restricts the producer to use only the last X bytes of data, where X is 61 a random number in the interval [0, data_size]. Returns the size of the 62 remaining data the producer won't use anymore (the prefix). */ 63 size_t FUZZ_dataProducer_reserveDataPrefix(FUZZ_dataProducer_t *producer); 64 #endif // FUZZ_DATA_PRODUCER_H 65