| 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 |