compiler-rt/lib/fuzzer/FuzzerIO.cpp

   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 AppendToFile(const std::string &Data, const std::string &Path) {
  81   AppendToFile(reinterpret_cast<const uint8_t *>(Data.data()), Data.size(),
  82                Path);
  83 }
  84
  85 void AppendToFile(const uint8_t *Data, size_t Size, const std::string &Path) {
  86   FILE *Out = fopen(Path.c_str(), "a");
  87   if (!Out)
  88     return;
  89   fwrite(Data, sizeof(Data[0]), Size, Out);
  90   fclose(Out);
  91 }
  92
  93 void ReadDirToVectorOfUnits(const char *Path, Vector<Unit> *V,
  94                             long *Epoch, size_t MaxSize, bool ExitOnError) {
  95   long E = Epoch ? *Epoch : 0;
  96   Vector<std::string> Files;
  97   ListFilesInDirRecursive(Path, Epoch, &Files, /*TopDir*/true);
  98   size_t NumLoaded = 0;
  99   for (size_t i = 0; i < Files.size(); i++) {
 100     auto &X = Files[i];
 101     if (Epoch && GetEpoch(X) < E) continue;
 102     NumLoaded++;
 103     if ((NumLoaded & (NumLoaded - 1)) == 0 && NumLoaded >= 1024)
 104       Printf("Loaded %zd/%zd files from %s\n", NumLoaded, Files.size(), Path);
 105     auto S = FileToVector(X, MaxSize, ExitOnError);
 106     if (!S.empty())
 107       V->push_back(S);
 108   }
 109 }
 110
 111
 112 void GetSizedFilesFromDir(const std::string &Dir, Vector<SizedFile> *V) {
 113   Vector<std::string> Files;
 114   ListFilesInDirRecursive(Dir, 0, &Files, /*TopDir*/true);
 115   for (auto &File : Files)
 116     if (size_t Size = FileSize(File))
 117       V->push_back({File, Size});
 118 }
 119
 120 std::string DirPlusFile(const std::string &DirPath,
 121                         const std::string &FileName) {
 122   return DirPath + GetSeparator() + FileName;
 123 }
 124
 125 void DupAndCloseStderr() {
 126   int OutputFd = DuplicateFile(2);
 127   if (OutputFd >= 0) {
 128     FILE *NewOutputFile = OpenFile(OutputFd, "w");
 129     if (NewOutputFile) {
 130       OutputFile = NewOutputFile;
 131       if (EF->__sanitizer_set_report_fd)
 132         EF->__sanitizer_set_report_fd(
 133             reinterpret_cast<void *>(GetHandleFromFd(OutputFd)));
 134       DiscardOutput(2);
 135     }
 136   }
 137 }
 138
 139 void CloseStdout() {
 140   DiscardOutput(1);
 141 }
 142
 143 void Printf(const char *Fmt, ...) {
 144   va_list ap;
 145   va_start(ap, Fmt);
 146   vfprintf(OutputFile, Fmt, ap);
 147   va_end(ap);
 148   fflush(OutputFile);
 149 }
 150
 151 void VPrintf(bool Verbose, const char *Fmt, ...) {
 152   if (!Verbose) return;
 153   va_list ap;
 154   va_start(ap, Fmt);
 155   vfprintf(OutputFile, Fmt, ap);
 156   va_end(ap);
 157   fflush(OutputFile);
 158 }
 159
 160 static bool MkDirRecursiveInner(const std::string &Leaf) {
 161   // Prevent chance of potential infinite recursion
 162   if (Leaf == ".")
 163     return true;
 164
 165   const std::string &Dir = DirName(Leaf);
 166
 167   if (IsDirectory(Dir)) {
 168     MkDir(Leaf);
 169     return IsDirectory(Leaf);
 170   }
 171
 172   bool ret = MkDirRecursiveInner(Dir);
 173   if (!ret) {
 174     // Give up early if a previous MkDir failed
 175     return ret;
 176   }
 177
 178   MkDir(Leaf);
 179   return IsDirectory(Leaf);
 180 }
 181
 182 bool MkDirRecursive(const std::string &Dir) {
 183   if (Dir.empty())
 184     return false;
 185
 186   if (IsDirectory(Dir))
 187     return true;
 188
 189   return MkDirRecursiveInner(Dir);
 190 }
 191
 192 void RmDirRecursive(const std::string &Dir) {
 193   IterateDirRecursive(
 194       Dir, [](const std::string &Path) {},
 195       [](const std::string &Path) { RmDir(Path); },
 196       [](const std::string &Path) { RemoveFile(Path); });
 197 }
 198
 199 std::string TempPath(const char *Prefix, const char *Extension) {
 200   return DirPlusFile(TmpDir(), std::string("libFuzzerTemp.") + Prefix +
 201                                    std::to_string(GetPid()) + Extension);
 202 }
 203
 204 }  // namespace fuzzer