| 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 | #include "fuzz_helpers.h" |
| 12 | #include "fuzz_data_producer.h" |
| 13 | |
| 14 | struct FUZZ_dataProducer_s{ |
| 15 | const uint8_t *data; |
| 16 | size_t size; |
| 17 | }; |
| 18 | |
| 19 | FUZZ_dataProducer_t *FUZZ_dataProducer_create(const uint8_t *data, size_t size) { |
| 20 | FUZZ_dataProducer_t *producer = FUZZ_malloc(sizeof(FUZZ_dataProducer_t)); |
| 21 | |
| 22 | producer->data = data; |
| 23 | producer->size = size; |
| 24 | return producer; |
| 25 | } |
| 26 | |
| 27 | void FUZZ_dataProducer_free(FUZZ_dataProducer_t *producer) { free(producer); } |
| 28 | |
| 29 | uint32_t FUZZ_dataProducer_uint32Range(FUZZ_dataProducer_t *producer, uint32_t min, |
| 30 | uint32_t max) { |
| 31 | FUZZ_ASSERT(min <= max); |
| 32 | |
| 33 | uint32_t range = max - min; |
| 34 | uint32_t rolling = range; |
| 35 | uint32_t result = 0; |
| 36 | |
| 37 | while (rolling > 0 && producer->size > 0) { |
| 38 | uint8_t next = *(producer->data + producer->size - 1); |
| 39 | producer->size -= 1; |
| 40 | result = (result << 8) | next; |
| 41 | rolling >>= 8; |
| 42 | } |
| 43 | |
| 44 | if (range == 0xffffffff) { |
| 45 | return result; |
| 46 | } |
| 47 | |
| 48 | return min + result % (range + 1); |
| 49 | } |
| 50 | |
| 51 | uint32_t FUZZ_dataProducer_uint32(FUZZ_dataProducer_t *producer) { |
| 52 | return FUZZ_dataProducer_uint32Range(producer, 0, 0xffffffff); |
| 53 | } |
| 54 | |
| 55 | int32_t FUZZ_dataProducer_int32Range(FUZZ_dataProducer_t *producer, |
| 56 | int32_t min, int32_t max) |
| 57 | { |
| 58 | FUZZ_ASSERT(min <= max); |
| 59 | |
| 60 | if (min < 0) |
| 61 | return (int)FUZZ_dataProducer_uint32Range(producer, 0, max - min) + min; |
| 62 | |
| 63 | return FUZZ_dataProducer_uint32Range(producer, min, max); |
| 64 | } |
| 65 | |
| 66 | size_t FUZZ_dataProducer_remainingBytes(FUZZ_dataProducer_t *producer){ |
| 67 | return producer->size; |
| 68 | } |
| 69 | |
| 70 | void FUZZ_dataProducer_rollBack(FUZZ_dataProducer_t *producer, size_t remainingBytes) |
| 71 | { |
| 72 | FUZZ_ASSERT(remainingBytes >= producer->size); |
| 73 | producer->size = remainingBytes; |
| 74 | } |
| 75 | |
| 76 | int FUZZ_dataProducer_empty(FUZZ_dataProducer_t *producer) { |
| 77 | return producer->size == 0; |
| 78 | } |
| 79 | |
| 80 | size_t FUZZ_dataProducer_contract(FUZZ_dataProducer_t *producer, size_t newSize) |
| 81 | { |
| 82 | newSize = newSize > producer->size ? producer->size : newSize; |
| 83 | |
| 84 | size_t remaining = producer->size - newSize; |
| 85 | producer->data = producer->data + remaining; |
| 86 | producer->size = newSize; |
| 87 | return remaining; |
| 88 | } |
| 89 | |
| 90 | size_t FUZZ_dataProducer_reserveDataPrefix(FUZZ_dataProducer_t *producer) |
| 91 | { |
| 92 | size_t producerSliceSize = FUZZ_dataProducer_uint32Range( |
| 93 | producer, 0, producer->size); |
| 94 | return FUZZ_dataProducer_contract(producer, producerSliceSize); |
| 95 | } |