1//===- FuzzerInterface.h - Interface header for the Fuzzer ------*- C++ -* ===// 2// 3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4// See https://llvm.org/LICENSE.txt for license information. 5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6// 7//===----------------------------------------------------------------------===// 8// Define the interface between libFuzzer and the library being tested. 9//===----------------------------------------------------------------------===// 10 11// NOTE: the libFuzzer interface is thin and in the majority of cases 12// you should not include this file into your target. In 95% of cases 13// all you need is to define the following function in your file: 14// extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size); 15 16// WARNING: keep the interface in C. 17 18#ifndef LLVM_FUZZER_INTERFACE_H 19#define LLVM_FUZZER_INTERFACE_H 20 21#include <stddef.h> 22#include <stdint.h> 23 24#ifdef __cplusplus 25extern "C" { 26#endif // __cplusplus 27 28// Define FUZZER_INTERFACE_VISIBILITY to set default visibility in a way that 29// doesn't break MSVC. 30#if defined(_WIN32) 31#define FUZZER_INTERFACE_VISIBILITY __declspec(dllexport) 32#else 33#define FUZZER_INTERFACE_VISIBILITY __attribute__((visibility("default"))) 34#endif 35 36// Mandatory user-provided target function. 37// Executes the code under test with [Data, Data+Size) as the input. 38// libFuzzer will invoke this function *many* times with different inputs. 39// Must return 0. 40FUZZER_INTERFACE_VISIBILITY int 41LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size); 42 43// Optional user-provided initialization function. 44// If provided, this function will be called by libFuzzer once at startup. 45// It may read and modify argc/argv. 46// Must return 0. 47FUZZER_INTERFACE_VISIBILITY int LLVMFuzzerInitialize(int *argc, char ***argv); 48 49// Optional user-provided custom mutator. 50// Mutates raw data in [Data, Data+Size) inplace. 51// Returns the new size, which is not greater than MaxSize. 52// Given the same Seed produces the same mutation. 53FUZZER_INTERFACE_VISIBILITY size_t 54LLVMFuzzerCustomMutator(uint8_t *Data, size_t Size, size_t MaxSize, 55 unsigned int Seed); 56 57// Optional user-provided custom cross-over function. 58// Combines pieces of Data1 & Data2 together into Out. 59// Returns the new size, which is not greater than MaxOutSize. 60// Should produce the same mutation given the same Seed. 61FUZZER_INTERFACE_VISIBILITY size_t 62LLVMFuzzerCustomCrossOver(const uint8_t *Data1, size_t Size1, 63 const uint8_t *Data2, size_t Size2, uint8_t *Out, 64 size_t MaxOutSize, unsigned int Seed); 65 66// Experimental, may go away in future. 67// libFuzzer-provided function to be used inside LLVMFuzzerCustomMutator. 68// Mutates raw data in [Data, Data+Size) inplace. 69// Returns the new size, which is not greater than MaxSize. 70FUZZER_INTERFACE_VISIBILITY size_t 71LLVMFuzzerMutate(uint8_t *Data, size_t Size, size_t MaxSize); 72 73#undef FUZZER_INTERFACE_VISIBILITY 74 75#ifdef __cplusplus 76} // extern "C" 77#endif // __cplusplus 78 79#endif // LLVM_FUZZER_INTERFACE_H 80