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

400 lines
13 KiB
C++

//===- FuzzerInternal.h - Internal 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 main class fuzzer::Fuzzer and most functions.
//===----------------------------------------------------------------------===//
#ifndef LLVM_FUZZER_INTERNAL_H
#define LLVM_FUZZER_INTERNAL_H
#include <algorithm>
#include <cassert>
#include <chrono>
#include <climits>
#include <cstddef>
#include <cstdlib>
#include <random>
#include <string.h>
#include <string>
#include <unordered_set>
#include <vector>
#include "FuzzerInterface.h"
namespace fuzzer {
using namespace std::chrono;
typedef std::vector<uint8_t> Unit;
// A simple POD sized array of bytes.
template <size_t kMaxSize> class FixedWord {
public:
FixedWord() {}
FixedWord(const uint8_t *B, uint8_t S) { Set(B, S); }
void Set(const uint8_t *B, uint8_t S) {
assert(S <= kMaxSize);
memcpy(Data, B, S);
Size = S;
}
bool operator==(const FixedWord<kMaxSize> &w) const {
return Size == w.Size && 0 == memcmp(Data, w.Data, Size);
}
bool operator<(const FixedWord<kMaxSize> &w) const {
if (Size != w.Size)
return Size < w.Size;
return memcmp(Data, w.Data, Size) < 0;
}
static size_t GetMaxSize() { return kMaxSize; }
const uint8_t *data() const { return Data; }
uint8_t size() const { return Size; }
private:
uint8_t Size = 0;
uint8_t Data[kMaxSize];
};
typedef FixedWord<27> Word; // 28 bytes.
bool IsFile(const std::string &Path);
std::string FileToString(const std::string &Path);
Unit FileToVector(const std::string &Path, size_t MaxSize = 0);
void ReadDirToVectorOfUnits(const char *Path, std::vector<Unit> *V,
long *Epoch, size_t MaxSize);
void WriteToFile(const Unit &U, const std::string &Path);
void CopyFileToErr(const std::string &Path);
// Returns "Dir/FileName" or equivalent for the current OS.
std::string DirPlusFile(const std::string &DirPath,
const std::string &FileName);
void Printf(const char *Fmt, ...);
void PrintHexArray(const Unit &U, const char *PrintAfter = "");
void PrintHexArray(const uint8_t *Data, size_t Size,
const char *PrintAfter = "");
void PrintASCII(const uint8_t *Data, size_t Size, const char *PrintAfter = "");
void PrintASCII(const Unit &U, const char *PrintAfter = "");
void PrintASCII(const Word &W, const char *PrintAfter = "");
std::string Hash(const Unit &U);
void SetTimer(int Seconds);
std::string Base64(const Unit &U);
int ExecuteCommand(const std::string &Command);
// Private copy of SHA1 implementation.
static const int kSHA1NumBytes = 20;
// Computes SHA1 hash of 'Len' bytes in 'Data', writes kSHA1NumBytes to 'Out'.
void ComputeSHA1(const uint8_t *Data, size_t Len, uint8_t *Out);
// Changes U to contain only ASCII (isprint+isspace) characters.
// Returns true iff U has been changed.
bool ToASCII(uint8_t *Data, size_t Size);
bool IsASCII(const Unit &U);
int NumberOfCpuCores();
int GetPid();
class Random {
public:
Random(unsigned int seed) : R(seed) {}
size_t Rand() { return R(); }
size_t RandBool() { return Rand() % 2; }
size_t operator()(size_t n) { return n ? Rand() % n : 0; }
std::mt19937 &Get_mt19937() { return R; }
private:
std::mt19937 R;
};
// Dictionary.
// Parses one dictionary entry.
// If successfull, write the enty to Unit and returns true,
// otherwise returns false.
bool ParseOneDictionaryEntry(const std::string &Str, Unit *U);
// Parses the dictionary file, fills Units, returns true iff all lines
// were parsed succesfully.
bool ParseDictionaryFile(const std::string &Text, std::vector<Unit> *Units);
class DictionaryEntry {
public:
DictionaryEntry() {}
DictionaryEntry(Word W) : W(W) {}
DictionaryEntry(Word W, size_t PositionHint) : W(W), PositionHint(PositionHint) {}
const Word &GetW() const { return W; }
bool HasPositionHint() const { return PositionHint != std::numeric_limits<size_t>::max(); }
size_t GetPositionHint() const {
assert(HasPositionHint());
return PositionHint;
}
void IncUseCount() { UseCount++; }
void IncSuccessCount() { SuccessCount++; }
size_t GetUseCount() const { return UseCount; }
size_t GetSuccessCount() const {return SuccessCount; }
private:
Word W;
size_t PositionHint = std::numeric_limits<size_t>::max();
size_t UseCount = 0;
size_t SuccessCount = 0;
};
class Dictionary {
public:
static const size_t kMaxDictSize = 1 << 14;
bool ContainsWord(const Word &W) const {
return std::any_of(begin(), end(), [&](const DictionaryEntry &DE) {
return DE.GetW() == W;
});
}
const DictionaryEntry *begin() const { return &DE[0]; }
const DictionaryEntry *end() const { return begin() + Size; }
DictionaryEntry & operator[] (size_t Idx) {
assert(Idx < Size);
return DE[Idx];
}
void push_back(DictionaryEntry DE) {
if (Size < kMaxDictSize)
this->DE[Size++] = DE;
}
void clear() { Size = 0; }
bool empty() const { return Size == 0; }
size_t size() const { return Size; }
private:
DictionaryEntry DE[kMaxDictSize];
size_t Size = 0;
};
class MutationDispatcher {
public:
MutationDispatcher(Random &Rand) : Rand(Rand) {}
~MutationDispatcher() {}
/// Indicate that we are about to start a new sequence of mutations.
void StartMutationSequence();
/// Print the current sequence of mutations.
void PrintMutationSequence();
/// Indicate that the current sequence of mutations was successfull.
void RecordSuccessfulMutationSequence();
/// Mutates data by shuffling bytes.
size_t Mutate_ShuffleBytes(uint8_t *Data, size_t Size, size_t MaxSize);
/// Mutates data by erasing a byte.
size_t Mutate_EraseByte(uint8_t *Data, size_t Size, size_t MaxSize);
/// Mutates data by inserting a byte.
size_t Mutate_InsertByte(uint8_t *Data, size_t Size, size_t MaxSize);
/// Mutates data by chanding one byte.
size_t Mutate_ChangeByte(uint8_t *Data, size_t Size, size_t MaxSize);
/// Mutates data by chanding one bit.
size_t Mutate_ChangeBit(uint8_t *Data, size_t Size, size_t MaxSize);
/// Mutates data by adding a word from the manual dictionary.
size_t Mutate_AddWordFromManualDictionary(uint8_t *Data, size_t Size,
size_t MaxSize);
/// Mutates data by adding a word from the temporary automatic dictionary.
size_t Mutate_AddWordFromTemporaryAutoDictionary(uint8_t *Data, size_t Size,
size_t MaxSize);
/// Mutates data by adding a word from the persistent automatic dictionary.
size_t Mutate_AddWordFromPersistentAutoDictionary(uint8_t *Data, size_t Size,
size_t MaxSize);
/// Tries to find an ASCII integer in Data, changes it to another ASCII int.
size_t Mutate_ChangeASCIIInteger(uint8_t *Data, size_t Size, size_t MaxSize);
/// CrossOver Data with some other element of the corpus.
size_t Mutate_CrossOver(uint8_t *Data, size_t Size, size_t MaxSize);
/// Applies one of the above mutations.
/// Returns the new size of data which could be up to MaxSize.
size_t Mutate(uint8_t *Data, size_t Size, size_t MaxSize);
/// Creates a cross-over of two pieces of Data, returns its size.
size_t CrossOver(const uint8_t *Data1, size_t Size1, const uint8_t *Data2,
size_t Size2, uint8_t *Out, size_t MaxOutSize);
void AddWordToManualDictionary(const Word &W);
void AddWordToAutoDictionary(const Word &W, size_t PositionHint);
void ClearAutoDictionary();
void PrintRecommendedDictionary();
void SetCorpus(const std::vector<Unit> *Corpus) { this->Corpus = Corpus; }
Random &GetRand() { return Rand; }
private:
struct Mutator {
size_t (MutationDispatcher::*Fn)(uint8_t *Data, size_t Size, size_t Max);
const char *Name;
};
size_t AddWordFromDictionary(Dictionary &D, uint8_t *Data, size_t Size,
size_t MaxSize);
Random &Rand;
// Dictionary provided by the user via -dict=DICT_FILE.
Dictionary ManualDictionary;
// Temporary dictionary modified by the fuzzer itself,
// recreated periodically.
Dictionary TempAutoDictionary;
// Persistent dictionary modified by the fuzzer, consists of
// entries that led to successfull discoveries in the past mutations.
Dictionary PersistentAutoDictionary;
std::vector<Mutator> CurrentMutatorSequence;
std::vector<DictionaryEntry *> CurrentDictionaryEntrySequence;
const std::vector<Unit> *Corpus = nullptr;
std::vector<uint8_t> MutateInPlaceHere;
static Mutator Mutators[];
};
class Fuzzer {
public:
struct FuzzingOptions {
int Verbosity = 1;
int MaxLen = 0;
int UnitTimeoutSec = 300;
bool AbortOnTimeout = false;
int TimeoutExitCode = 77;
int MaxTotalTimeSec = 0;
bool DoCrossOver = true;
int MutateDepth = 5;
bool ExitOnFirst = false;
bool UseCounters = false;
bool UseIndirCalls = true;
bool UseTraces = false;
bool UseMemcmp = true;
bool UseFullCoverageSet = false;
bool Reload = true;
bool ShuffleAtStartUp = true;
int PreferSmallDuringInitialShuffle = -1;
size_t MaxNumberOfRuns = ULONG_MAX;
int SyncTimeout = 600;
int ReportSlowUnits = 10;
bool OnlyASCII = false;
std::string OutputCorpus;
std::string SyncCommand;
std::string ArtifactPrefix = "./";
std::string ExactArtifactPath;
bool SaveArtifacts = true;
bool PrintNEW = true; // Print a status line when new units are found;
bool OutputCSV = false;
bool PrintNewCovPcs = false;
};
Fuzzer(UserCallback CB, MutationDispatcher &MD, FuzzingOptions Options);
void AddToCorpus(const Unit &U) {
Corpus.push_back(U);
UpdateCorpusDistribution();
}
size_t ChooseUnitIdxToMutate();
const Unit &ChooseUnitToMutate() { return Corpus[ChooseUnitIdxToMutate()]; };
void Loop();
void Drill();
void ShuffleAndMinimize();
void InitializeTraceState();
void AssignTaintLabels(uint8_t *Data, size_t Size);
size_t CorpusSize() const { return Corpus.size(); }
void ReadDir(const std::string &Path, long *Epoch, size_t MaxSize) {
Printf("Loading corpus: %s\n", Path.c_str());
ReadDirToVectorOfUnits(Path.c_str(), &Corpus, Epoch, MaxSize);
}
void RereadOutputCorpus();
// Save the current corpus to OutputCorpus.
void SaveCorpus();
size_t secondsSinceProcessStartUp() {
return duration_cast<seconds>(system_clock::now() - ProcessStartTime)
.count();
}
size_t getTotalNumberOfRuns() { return TotalNumberOfRuns; }
static void StaticAlarmCallback();
void ExecuteCallback(const uint8_t *Data, size_t Size);
// Merge Corpora[1:] into Corpora[0].
void Merge(const std::vector<std::string> &Corpora);
MutationDispatcher &GetMD() { return MD; }
private:
void AlarmCallback();
void MutateAndTestOne();
void ReportNewCoverage(const Unit &U);
bool RunOne(const uint8_t *Data, size_t Size);
bool RunOne(const Unit &U) { return RunOne(U.data(), U.size()); }
void RunOneAndUpdateCorpus(uint8_t *Data, size_t Size);
void WriteToOutputCorpus(const Unit &U);
void WriteUnitToFileWithPrefix(const Unit &U, const char *Prefix);
void PrintStats(const char *Where, const char *End = "\n");
void PrintStatusForNewUnit(const Unit &U);
// Updates the probability distribution for the units in the corpus.
// Must be called whenever the corpus or unit weights are changed.
void UpdateCorpusDistribution();
void SyncCorpus();
size_t RecordBlockCoverage();
size_t RecordCallerCalleeCoverage();
void PrepareCoverageBeforeRun();
bool CheckCoverageAfterRun();
// Trace-based fuzzing: we run a unit with some kind of tracing
// enabled and record potentially useful mutations. Then
// We apply these mutations one by one to the unit and run it again.
// Start tracing; forget all previously proposed mutations.
void StartTraceRecording();
// Stop tracing.
void StopTraceRecording();
void SetDeathCallback();
static void StaticDeathCallback();
void DeathCallback();
uint8_t *CurrentUnitData;
size_t CurrentUnitSize;
size_t TotalNumberOfRuns = 0;
size_t TotalNumberOfExecutedTraceBasedMutations = 0;
std::vector<Unit> Corpus;
std::unordered_set<std::string> UnitHashesAddedToCorpus;
// For UseCounters
std::vector<uint8_t> CounterBitmap;
size_t TotalBits() { // Slow. Call it only for printing stats.
size_t Res = 0;
for (auto x : CounterBitmap)
Res += __builtin_popcount(x);
return Res;
}
std::vector<uint8_t> MutateInPlaceHere;
std::piecewise_constant_distribution<double> CorpusDistribution;
UserCallback CB;
MutationDispatcher &MD;
FuzzingOptions Options;
system_clock::time_point ProcessStartTime = system_clock::now();
system_clock::time_point LastExternalSync = system_clock::now();
system_clock::time_point UnitStartTime;
long TimeOfLongestUnitInSeconds = 0;
long EpochOfLastReadOfOutputCorpus = 0;
size_t LastRecordedBlockCoverage = 0;
size_t LastRecordedCallerCalleeCoverage = 0;
size_t LastCoveragePcBufferLen = 0;
};
}; // namespace fuzzer
#endif // LLVM_FUZZER_INTERNAL_H