1 /* 2 * Copyright (c) Meta Platforms, Inc. and affiliates. 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 28 /* Struct used for maintaining the state of the data */ 29 typedef struct FUZZ_dataProducer_s FUZZ_dataProducer_t; 30 31 /* Returns a data producer state struct. Use for producer initialization. */ 32 FUZZ_dataProducer_t *FUZZ_dataProducer_create(const uint8_t *data, size_t size); 33 34 /* Frees the data producer */ 35 void FUZZ_dataProducer_free(FUZZ_dataProducer_t *producer); 36 37 /* Returns value between [min, max] */ 38 uint32_t FUZZ_dataProducer_uint32Range(FUZZ_dataProducer_t *producer, uint32_t min, 39 uint32_t max); 40 41 /* Returns a uint32 value */ 42 uint32_t FUZZ_dataProducer_uint32(FUZZ_dataProducer_t *producer); 43 44 /* Returns a signed value between [min, max] */ 45 int32_t FUZZ_dataProducer_int32Range(FUZZ_dataProducer_t *producer, 46 int32_t min, int32_t max); 47 48 /* Returns the size of the remaining bytes of data in the producer */ 49 size_t FUZZ_dataProducer_remainingBytes(FUZZ_dataProducer_t *producer); 50 51 /* Rolls back the data producer state to have remainingBytes remaining */ 52 void FUZZ_dataProducer_rollBack(FUZZ_dataProducer_t *producer, size_t remainingBytes); 53 54 /* Returns true if the data producer is out of bytes */ 55 int FUZZ_dataProducer_empty(FUZZ_dataProducer_t *producer); 56 57 /* Restricts the producer to only the last newSize bytes of data. 58 If newSize > current data size, nothing happens. Returns the number of bytes 59 the producer won't use anymore, after contracting. */ 60 size_t FUZZ_dataProducer_contract(FUZZ_dataProducer_t *producer, size_t newSize); 61 62 /* Restricts the producer to use only the last X bytes of data, where X is 63 a random number in the interval [0, data_size]. Returns the size of the 64 remaining data the producer won't use anymore (the prefix). */ 65 size_t FUZZ_dataProducer_reserveDataPrefix(FUZZ_dataProducer_t *producer); 66 #endif // FUZZ_DATA_PRODUCER_H 67