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
22namespace fuzzer {
23
24static FILE *OutputFile = stderr;
25
26long 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
33Unit 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
53std::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
59void CopyFileToErr(const std::string &Path) {
60  Printf("%s", FileToString(Path).c_str());
61}
62
63void WriteToFile(const Unit &U, const std::string &Path) {
64  WriteToFile(U.data(), U.size(), Path);
65}
66
67void 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
72void 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
80void 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
99void 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
107std::string DirPlusFile(const std::string &DirPath,
108                        const std::string &FileName) {
109  return DirPath + GetSeparator() + FileName;
110}
111
112void 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
126void CloseStdout() {
127  DiscardOutput(1);
128}
129
130void 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
138void 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
147void 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
154std::string TempPath(const char *Extension) {
155  return DirPlusFile(TmpDir(),
156                     "libFuzzerTemp." + std::to_string(GetPid()) + Extension);
157}
158
159}  // namespace fuzzer
160