1// Copyright 2014 The Chromium Authors. All rights reserved. 2// Use of this source code is governed by a BSD-style license that can be 3// found in the LICENSE file. 4 5#include "base/command_line.h" 6#include "base/files/file.h" 7#include "base/files/file_util.h" 8#include "base/strings/string_number_conversions.h" 9#include "net/spdy/fuzzing/hpack_fuzz_util.h" 10 11namespace { 12 13// Specifies a file having HPACK header sets. 14const char kFileToParse[] = "file-to-parse"; 15 16// Target file for mutated HPACK header sets. 17const char kFileToWrite[] = "file-to-write"; 18 19// Number of bits to flip per 1,024 bytes of input. 20const char kFlipsPerThousand[] = "flips-per-thousand-bytes"; 21 22} // namespace 23 24using base::StringPiece; 25using net::HpackFuzzUtil; 26using std::string; 27 28// Reads length-prefixed input blocks, applies a bit-flipping mutation to each 29// block, and writes length-prefixed blocks to the output file. While blocks 30// themselves are mutated, the length-prefixes of written blocks are not. 31int main(int argc, char** argv) { 32 base::CommandLine::Init(argc, argv); 33 const base::CommandLine& command_line = 34 *base::CommandLine::ForCurrentProcess(); 35 36 if (!command_line.HasSwitch(kFileToParse) || 37 !command_line.HasSwitch(kFileToWrite) || 38 !command_line.HasSwitch(kFlipsPerThousand)) { 39 LOG(ERROR) << "Usage: " << argv[0] 40 << " --" << kFileToParse << "=/path/to/file.in" 41 << " --" << kFileToWrite << "=/path/to/file.out" 42 << " --" << kFlipsPerThousand << "=10"; 43 return -1; 44 } 45 string file_to_parse = command_line.GetSwitchValueASCII(kFileToParse); 46 string file_to_write = command_line.GetSwitchValueASCII(kFileToWrite); 47 48 int flip_ratio = 0; 49 CHECK(base::StringToInt(command_line.GetSwitchValueASCII(kFlipsPerThousand), 50 &flip_ratio)); 51 52 DVLOG(1) << "Reading input from " << file_to_parse; 53 HpackFuzzUtil::Input input; 54 CHECK(base::ReadFileToString(base::FilePath::FromUTF8Unsafe(file_to_parse), 55 &input.input)); 56 57 DVLOG(1) << "Writing output to " << file_to_write; 58 base::File file_out(base::FilePath::FromUTF8Unsafe(file_to_write), 59 base::File::FLAG_CREATE_ALWAYS | base::File::FLAG_WRITE); 60 CHECK(file_out.IsValid()) << file_out.error_details(); 61 62 DVLOG(1) << "Flipping " << flip_ratio << " bits per 1024 input bytes"; 63 64 size_t block_count = 0; 65 StringPiece block; 66 while (HpackFuzzUtil::NextHeaderBlock(&input, &block)) { 67 HpackFuzzUtil::FlipBits( 68 reinterpret_cast<uint8*>(const_cast<char*>(block.data())), 69 block.size(), 70 flip_ratio); 71 72 string prefix = HpackFuzzUtil::HeaderBlockPrefix(block.size()); 73 74 CHECK_LT(0, file_out.WriteAtCurrentPos(prefix.data(), prefix.size())); 75 CHECK_LT(0, file_out.WriteAtCurrentPos(block.data(), block.size())); 76 ++block_count; 77 } 78 CHECK(file_out.Flush()); 79 DVLOG(1) << "Mutated " << block_count << " blocks."; 80 return 0; 81} 82