llvm-project/llvm/lib/Fuzzer/FuzzerInterface.h

156 lines
4.6 KiB
C++

//===- FuzzerInterface.h - Interface header for the Fuzzer ------*- C++ -* ===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// Define the interface between the Fuzzer and the library being tested.
//===----------------------------------------------------------------------===//
// WARNING: keep the interface free of STL or any other header-based C++ lib,
// to avoid bad interactions between the code used in the fuzzer and
// the code used in the target function.
#ifndef LLVM_FUZZER_INTERFACE_H
#define LLVM_FUZZER_INTERFACE_H
#include <limits>
#include <cstddef>
#include <cstdint>
#include <vector>
#include <string>
namespace fuzzer {
/// Returns an int 0. Values other than zero are reserved for future.
typedef int (*UserCallback)(const uint8_t *Data, size_t Size);
/** Simple C-like interface with a single user-supplied callback.
Usage:
#\code
#include "FuzzerInterface.h"
int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
DoStuffWithData(Data, Size);
return 0;
}
// Optional.
// Define this only if you need to read/modify argc/argv at startup
// and you are using libFuzzer's main().
// Must return 0.
int LLVMFuzzerInitialize(int *argc, char ***argv) {
ReadAndMaybeModify(argc, argv);
return 0;
}
// Implement your own main() or use the one from FuzzerMain.cpp.
int main(int argc, char **argv) {
InitializeMeIfNeeded();
return fuzzer::FuzzerDriver(argc, argv, LLVMFuzzerTestOneInput);
}
#\endcode
*/
int FuzzerDriver(int argc, char **argv, UserCallback Callback);
class FuzzerRandomBase {
public:
FuzzerRandomBase(){}
virtual ~FuzzerRandomBase(){};
virtual void ResetSeed(unsigned int seed) = 0;
// Return a random number.
virtual size_t Rand() = 0;
// Return a random number in range [0,n).
size_t operator()(size_t n) { return n ? Rand() % n : 0; }
bool RandBool() { return Rand() % 2; }
};
// Using libc's stand/rand.
class FuzzerRandomLibc : public FuzzerRandomBase {
public:
FuzzerRandomLibc(unsigned int seed) { ResetSeed(seed); }
void ResetSeed(unsigned int seed) override;
~FuzzerRandomLibc() override {};
size_t Rand() override;
};
// Using std::mt19937
class FuzzerRandom_mt19937 : public FuzzerRandomBase {
public:
FuzzerRandom_mt19937(unsigned int seed) { ResetSeed(seed); }
void ResetSeed(unsigned int seed) override;
~FuzzerRandom_mt19937() override;
size_t Rand() override;
private:
struct Impl;
Impl *R = nullptr;
};
// For backward compatibility only, deprecated.
size_t Mutate(uint8_t *Data, size_t Size, size_t MaxSize,
FuzzerRandomBase &Rand);
class MutationDispatcher;
/** An abstract class that allows to use user-supplied mutators with libFuzzer.
Usage:
#\code
#include "FuzzerInterface.h"
class MyFuzzer : public fuzzer::UserSuppliedFuzzer {
public:
MyFuzzer(fuzzer::FuzzerRandomBase *Rand);
// Must define the target function.
int TargetFunction(...) { ...; return 0; }
// Optionally define the mutator.
size_t Mutate(...) { ... }
// Optionally define the CrossOver method.
size_t CrossOver(...) { ... }
};
int main(int argc, char **argv) {
MyFuzzer F;
fuzzer::FuzzerDriver(argc, argv, F);
}
#\endcode
*/
class UserSuppliedFuzzer {
public:
UserSuppliedFuzzer(FuzzerRandomBase *Rand);
/// Executes the target function on 'Size' bytes of 'Data'.
virtual int TargetFunction(const uint8_t *Data, size_t Size) = 0;
/// Mutates 'Size' bytes of data in 'Data' inplace into up to 'MaxSize' bytes,
/// returns the new size of the data, which should be positive.
virtual size_t Mutate(uint8_t *Data, size_t Size, size_t MaxSize);
/// Crosses 'Data1' and 'Data2', writes up to 'MaxOutSize' bytes into Out,
/// returns the number of bytes written, which should be positive.
virtual size_t CrossOver(const uint8_t *Data1, size_t Size1,
const uint8_t *Data2, size_t Size2,
uint8_t *Out, size_t MaxOutSize);
virtual ~UserSuppliedFuzzer();
FuzzerRandomBase &GetRand() { return *Rand; }
MutationDispatcher &GetMD() { return *MD; }
private:
bool OwnRand = false;
FuzzerRandomBase *Rand;
MutationDispatcher *MD;
};
/// Runs the fuzzing with the UserSuppliedFuzzer.
int FuzzerDriver(int argc, char **argv, UserSuppliedFuzzer &USF);
/// More C++-ish interface.
int FuzzerDriver(const std::vector<std::string> &Args, UserSuppliedFuzzer &USF);
int FuzzerDriver(const std::vector<std::string> &Args, UserCallback Callback);
} // namespace fuzzer
#endif // LLVM_FUZZER_INTERFACE_H