1// This file is distributed under the University of Illinois Open Source
2// License. See LICENSE.TXT for details.
3
4// Simple test for a cutom mutator.
5#include <assert.h>
6#include <cstddef>
7#include <cstdint>
8#include <cstdlib>
9#include <iostream>
10#include <random>
11#include <string.h>
12
13#include "FuzzerInterface.h"
14
15static const char *Separator = "-_^_-";
16static const char *Target = "012-_^_-abc";
17
18static volatile int sink;
19
20extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
21  assert(Data);
22  std::string Str(reinterpret_cast<const char *>(Data), Size);
23
24  // Ensure that two different elements exist in the corpus.
25  if (Size && Data[0] == '0') sink++;
26  if (Size && Data[0] == 'a') sink--;
27
28  if (Str.find(Target) != std::string::npos) {
29    std::cout << "BINGO; Found the target, exiting\n";
30    exit(1);
31  }
32  return 0;
33}
34
35extern "C" size_t LLVMFuzzerCustomCrossOver(const uint8_t *Data1, size_t Size1,
36                                            const uint8_t *Data2, size_t Size2,
37                                            uint8_t *Out, size_t MaxOutSize,
38                                            unsigned int Seed) {
39  static bool Printed;
40  static size_t SeparatorLen = strlen(Separator);
41
42  if (!Printed) {
43    std::cerr << "In LLVMFuzzerCustomCrossover\n";
44    Printed = true;
45  }
46
47  std::mt19937 R(Seed);
48
49  size_t Offset1 = 0;
50  size_t Len1 = R() % (Size1 - Offset1);
51  size_t Offset2 = 0;
52  size_t Len2 = R() % (Size2 - Offset2);
53  size_t Size = Len1 + Len2 + SeparatorLen;
54
55  if (Size > MaxOutSize)
56    return 0;
57
58  memcpy(Out, Data1 + Offset1, Len1);
59  memcpy(Out + Len1, Separator, SeparatorLen);
60  memcpy(Out + Len1 + SeparatorLen, Data2 + Offset2, Len2);
61
62  return Len1 + Len2 + SeparatorLen;
63}
64