1 //===- FuzzerIO.cpp - IO utils. -------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // IO functions. 9 //===----------------------------------------------------------------------===// 10 11 #include "FuzzerDefs.h" 12 #include "FuzzerExtFunctions.h" 13 #include "FuzzerIO.h" 14 #include "FuzzerUtil.h" 15 #include <algorithm> 16 #include <cstdarg> 17 #include <fstream> 18 #include <iterator> 19 #include <sys/stat.h> 20 #include <sys/types.h> 21 22 namespace fuzzer { 23 24 static FILE *OutputFile = stderr; 25 26 long GetEpoch(const std::string &Path) { 27 struct stat St; 28 if (stat(Path.c_str(), &St)) 29 return 0; // Can't stat, be conservative. 30 return St.st_mtime; 31 } 32 33 Unit FileToVector(const std::string &Path, size_t MaxSize, bool ExitOnError) { 34 std::ifstream T(Path, std::ios::binary); 35 if (ExitOnError && !T) { 36 Printf("No such directory: %s; exiting\n", Path.c_str()); 37 exit(1); 38 } 39 40 T.seekg(0, T.end); 41 auto EndPos = T.tellg(); 42 if (EndPos < 0) return {}; 43 size_t FileLen = EndPos; 44 if (MaxSize) 45 FileLen = std::min(FileLen, MaxSize); 46 47 T.seekg(0, T.beg); 48 Unit Res(FileLen); 49 T.read(reinterpret_cast<char *>(Res.data()), FileLen); 50 return Res; 51 } 52 53 std::string FileToString(const std::string &Path) { 54 std::ifstream T(Path, std::ios::binary); 55 return std::string((std::istreambuf_iterator<char>(T)), 56 std::istreambuf_iterator<char>()); 57 } 58 59 void CopyFileToErr(const std::string &Path) { 60 Printf("%s", FileToString(Path).c_str()); 61 } 62 63 void WriteToFile(const Unit &U, const std::string &Path) { 64 WriteToFile(U.data(), U.size(), Path); 65 } 66 67 void WriteToFile(const std::string &Data, const std::string &Path) { 68 WriteToFile(reinterpret_cast<const uint8_t *>(Data.c_str()), Data.size(), 69 Path); 70 } 71 72 void WriteToFile(const uint8_t *Data, size_t Size, const std::string &Path) { 73 // Use raw C interface because this function may be called from a sig handler. 74 FILE *Out = fopen(Path.c_str(), "wb"); 75 if (!Out) return; 76 fwrite(Data, sizeof(Data[0]), Size, Out); 77 fclose(Out); 78 } 79 80 void ReadDirToVectorOfUnits(const char *Path, Vector<Unit> *V, 81 long *Epoch, size_t MaxSize, bool ExitOnError) { 82 long E = Epoch ? *Epoch : 0; 83 Vector<std::string> Files; 84 ListFilesInDirRecursive(Path, Epoch, &Files, /*TopDir*/true); 85 size_t NumLoaded = 0; 86 for (size_t i = 0; i < Files.size(); i++) { 87 auto &X = Files[i]; 88 if (Epoch && GetEpoch(X) < E) continue; 89 NumLoaded++; 90 if ((NumLoaded & (NumLoaded - 1)) == 0 && NumLoaded >= 1024) 91 Printf("Loaded %zd/%zd files from %s\n", NumLoaded, Files.size(), Path); 92 auto S = FileToVector(X, MaxSize, ExitOnError); 93 if (!S.empty()) 94 V->push_back(S); 95 } 96 } 97 98 99 void GetSizedFilesFromDir(const std::string &Dir, Vector<SizedFile> *V) { 100 Vector<std::string> Files; 101 ListFilesInDirRecursive(Dir, 0, &Files, /*TopDir*/true); 102 for (auto &File : Files) 103 if (size_t Size = FileSize(File)) 104 V->push_back({File, Size}); 105 } 106 107 std::string DirPlusFile(const std::string &DirPath, 108 const std::string &FileName) { 109 return DirPath + GetSeparator() + FileName; 110 } 111 112 void DupAndCloseStderr() { 113 int OutputFd = DuplicateFile(2); 114 if (OutputFd >= 0) { 115 FILE *NewOutputFile = OpenFile(OutputFd, "w"); 116 if (NewOutputFile) { 117 OutputFile = NewOutputFile; 118 if (EF->__sanitizer_set_report_fd) 119 EF->__sanitizer_set_report_fd( 120 reinterpret_cast<void *>(GetHandleFromFd(OutputFd))); 121 DiscardOutput(2); 122 } 123 } 124 } 125 126 void CloseStdout() { 127 DiscardOutput(1); 128 } 129 130 void Printf(const char *Fmt, ...) { 131 va_list ap; 132 va_start(ap, Fmt); 133 vfprintf(OutputFile, Fmt, ap); 134 va_end(ap); 135 fflush(OutputFile); 136 } 137 138 void VPrintf(bool Verbose, const char *Fmt, ...) { 139 if (!Verbose) return; 140 va_list ap; 141 va_start(ap, Fmt); 142 vfprintf(OutputFile, Fmt, ap); 143 va_end(ap); 144 fflush(OutputFile); 145 } 146 147 void RmDirRecursive(const std::string &Dir) { 148 IterateDirRecursive( 149 Dir, [](const std::string &Path) {}, 150 [](const std::string &Path) { RmDir(Path); }, 151 [](const std::string &Path) { RemoveFile(Path); }); 152 } 153 154 std::string TempPath(const char *Prefix, const char *Extension) { 155 return DirPlusFile(TmpDir(), std::string("libFuzzerTemp.") + Prefix + 156 std::to_string(GetPid()) + Extension); 157 } 158 159 } // namespace fuzzer 160