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1 //===- FuzzerMutate.h - Internal header for the Fuzzer ----------*- C++ -* ===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 // fuzzer::MutationDispatcher
10 //===----------------------------------------------------------------------===//
11 
12 #ifndef LLVM_FUZZER_MUTATE_H
13 #define LLVM_FUZZER_MUTATE_H
14 
15 #include "FuzzerDefs.h"
16 #include "FuzzerDictionary.h"
17 #include "FuzzerRandom.h"
18 
19 namespace fuzzer {
20 
21 class MutationDispatcher {
22 public:
23   MutationDispatcher(Random &Rand, const FuzzingOptions &Options);
~MutationDispatcher()24   ~MutationDispatcher() {}
25   /// Indicate that we are about to start a new sequence of mutations.
26   void StartMutationSequence();
27   /// Print the current sequence of mutations.
28   void PrintMutationSequence();
29   /// Indicate that the current sequence of mutations was successfull.
30   void RecordSuccessfulMutationSequence();
31   /// Mutates data by invoking user-provided mutator.
32   size_t Mutate_Custom(uint8_t *Data, size_t Size, size_t MaxSize);
33   /// Mutates data by invoking user-provided crossover.
34   size_t Mutate_CustomCrossOver(uint8_t *Data, size_t Size, size_t MaxSize);
35   /// Mutates data by shuffling bytes.
36   size_t Mutate_ShuffleBytes(uint8_t *Data, size_t Size, size_t MaxSize);
37   /// Mutates data by erasing bytes.
38   size_t Mutate_EraseBytes(uint8_t *Data, size_t Size, size_t MaxSize);
39   /// Mutates data by inserting a byte.
40   size_t Mutate_InsertByte(uint8_t *Data, size_t Size, size_t MaxSize);
41   /// Mutates data by inserting several repeated bytes.
42   size_t Mutate_InsertRepeatedBytes(uint8_t *Data, size_t Size, size_t MaxSize);
43   /// Mutates data by chanding one byte.
44   size_t Mutate_ChangeByte(uint8_t *Data, size_t Size, size_t MaxSize);
45   /// Mutates data by chanding one bit.
46   size_t Mutate_ChangeBit(uint8_t *Data, size_t Size, size_t MaxSize);
47   /// Mutates data by copying/inserting a part of data into a different place.
48   size_t Mutate_CopyPart(uint8_t *Data, size_t Size, size_t MaxSize);
49 
50   /// Mutates data by adding a word from the manual dictionary.
51   size_t Mutate_AddWordFromManualDictionary(uint8_t *Data, size_t Size,
52                                             size_t MaxSize);
53 
54   /// Mutates data by adding a word from the temporary automatic dictionary.
55   size_t Mutate_AddWordFromTemporaryAutoDictionary(uint8_t *Data, size_t Size,
56                                                    size_t MaxSize);
57 
58   /// Mutates data by adding a word from the TORC.
59   size_t Mutate_AddWordFromTORC(uint8_t *Data, size_t Size, size_t MaxSize);
60 
61   /// Mutates data by adding a word from the persistent automatic dictionary.
62   size_t Mutate_AddWordFromPersistentAutoDictionary(uint8_t *Data, size_t Size,
63                                                     size_t MaxSize);
64 
65   /// Tries to find an ASCII integer in Data, changes it to another ASCII int.
66   size_t Mutate_ChangeASCIIInteger(uint8_t *Data, size_t Size, size_t MaxSize);
67   /// Change a 1-, 2-, 4-, or 8-byte integer in interesting ways.
68   size_t Mutate_ChangeBinaryInteger(uint8_t *Data, size_t Size, size_t MaxSize);
69 
70   /// CrossOver Data with some other element of the corpus.
71   size_t Mutate_CrossOver(uint8_t *Data, size_t Size, size_t MaxSize);
72 
73   /// Applies one of the configured mutations.
74   /// Returns the new size of data which could be up to MaxSize.
75   size_t Mutate(uint8_t *Data, size_t Size, size_t MaxSize);
76   /// Applies one of the default mutations. Provided as a service
77   /// to mutation authors.
78   size_t DefaultMutate(uint8_t *Data, size_t Size, size_t MaxSize);
79 
80   /// Creates a cross-over of two pieces of Data, returns its size.
81   size_t CrossOver(const uint8_t *Data1, size_t Size1, const uint8_t *Data2,
82                    size_t Size2, uint8_t *Out, size_t MaxOutSize);
83 
84   void AddWordToManualDictionary(const Word &W);
85 
86   void AddWordToAutoDictionary(DictionaryEntry DE);
87   void ClearAutoDictionary();
88   void PrintRecommendedDictionary();
89 
SetCorpus(const InputCorpus * Corpus)90   void SetCorpus(const InputCorpus *Corpus) { this->Corpus = Corpus; }
91 
GetRand()92   Random &GetRand() { return Rand; }
93 
94 private:
95 
96   struct Mutator {
97     size_t (MutationDispatcher::*Fn)(uint8_t *Data, size_t Size, size_t Max);
98     const char *Name;
99   };
100 
101   size_t AddWordFromDictionary(Dictionary &D, uint8_t *Data, size_t Size,
102                                size_t MaxSize);
103   size_t MutateImpl(uint8_t *Data, size_t Size, size_t MaxSize,
104                     const std::vector<Mutator> &Mutators);
105 
106   size_t InsertPartOf(const uint8_t *From, size_t FromSize, uint8_t *To,
107                       size_t ToSize, size_t MaxToSize);
108   size_t CopyPartOf(const uint8_t *From, size_t FromSize, uint8_t *To,
109                     size_t ToSize);
110   size_t ApplyDictionaryEntry(uint8_t *Data, size_t Size, size_t MaxSize,
111                               DictionaryEntry &DE);
112 
113   template <class T>
114   DictionaryEntry MakeDictionaryEntryFromCMP(T Arg1, T Arg2,
115                                              const uint8_t *Data, size_t Size);
116 
117   Random &Rand;
118   const FuzzingOptions &Options;
119 
120   // Dictionary provided by the user via -dict=DICT_FILE.
121   Dictionary ManualDictionary;
122   // Temporary dictionary modified by the fuzzer itself,
123   // recreated periodically.
124   Dictionary TempAutoDictionary;
125   // Persistent dictionary modified by the fuzzer, consists of
126   // entries that led to successfull discoveries in the past mutations.
127   Dictionary PersistentAutoDictionary;
128 
129   std::vector<Mutator> CurrentMutatorSequence;
130   std::vector<DictionaryEntry *> CurrentDictionaryEntrySequence;
131 
132   static const size_t kCmpDictionaryEntriesDequeSize = 16;
133   DictionaryEntry CmpDictionaryEntriesDeque[kCmpDictionaryEntriesDequeSize];
134   size_t CmpDictionaryEntriesDequeIdx = 0;
135 
136   const InputCorpus *Corpus = nullptr;
137   std::vector<uint8_t> MutateInPlaceHere;
138 
139   std::vector<Mutator> Mutators;
140   std::vector<Mutator> DefaultMutators;
141 };
142 
143 }  // namespace fuzzer
144 
145 #endif  // LLVM_FUZZER_MUTATE_H
146