llvm-project/compiler-rt/lib/fuzzer/FuzzerIOPosix.cpp
Matt Morehouse 2392ff093a [libFuzzer] Error and exit if user supplied fuzzer writeable directories don't exist
Currently, libFuzzer will exit with an error message if a non-existent
corpus directory is provided. However, if a user provides a non-existent
directory for the `artifact_prefix`, `exact_artifact_path`, or
`features_dir`, libFuzzer will continue execution but silently fail to
write artifacts/features.

To improve the user experience, this PR adds validation for the existence of
all user supplied directories before executing the main fuzzing loop. If they
don't exist, libFuzzer will exit with an error message.

Patch By: dgg5503

Reviewed By: morehouse

Differential Revision: https://reviews.llvm.org/D84808
2020-08-26 09:27:07 -07:00

181 lines
4.5 KiB
C++

//===- FuzzerIOPosix.cpp - IO utils for Posix. ----------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// IO functions implementation using Posix API.
//===----------------------------------------------------------------------===//
#include "FuzzerPlatform.h"
#if LIBFUZZER_POSIX || LIBFUZZER_FUCHSIA
#include "FuzzerExtFunctions.h"
#include "FuzzerIO.h"
#include <cstdarg>
#include <cstdio>
#include <dirent.h>
#include <fstream>
#include <iterator>
#include <libgen.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
namespace fuzzer {
bool IsFile(const std::string &Path) {
struct stat St;
if (stat(Path.c_str(), &St))
return false;
return S_ISREG(St.st_mode);
}
bool IsDirectory(const std::string &Path) {
struct stat St;
if (stat(Path.c_str(), &St))
return false;
return S_ISDIR(St.st_mode);
}
size_t FileSize(const std::string &Path) {
struct stat St;
if (stat(Path.c_str(), &St))
return 0;
return St.st_size;
}
std::string Basename(const std::string &Path) {
size_t Pos = Path.rfind(GetSeparator());
if (Pos == std::string::npos) return Path;
assert(Pos < Path.size());
return Path.substr(Pos + 1);
}
void ListFilesInDirRecursive(const std::string &Dir, long *Epoch,
Vector<std::string> *V, bool TopDir) {
auto E = GetEpoch(Dir);
if (Epoch)
if (E && *Epoch >= E) return;
DIR *D = opendir(Dir.c_str());
if (!D) {
Printf("%s: %s; exiting\n", strerror(errno), Dir.c_str());
exit(1);
}
while (auto E = readdir(D)) {
std::string Path = DirPlusFile(Dir, E->d_name);
if (E->d_type == DT_REG || E->d_type == DT_LNK ||
(E->d_type == DT_UNKNOWN && IsFile(Path)))
V->push_back(Path);
else if ((E->d_type == DT_DIR ||
(E->d_type == DT_UNKNOWN && IsDirectory(Path))) &&
*E->d_name != '.')
ListFilesInDirRecursive(Path, Epoch, V, false);
}
closedir(D);
if (Epoch && TopDir)
*Epoch = E;
}
void IterateDirRecursive(const std::string &Dir,
void (*DirPreCallback)(const std::string &Dir),
void (*DirPostCallback)(const std::string &Dir),
void (*FileCallback)(const std::string &Dir)) {
DirPreCallback(Dir);
DIR *D = opendir(Dir.c_str());
if (!D) return;
while (auto E = readdir(D)) {
std::string Path = DirPlusFile(Dir, E->d_name);
if (E->d_type == DT_REG || E->d_type == DT_LNK ||
(E->d_type == DT_UNKNOWN && IsFile(Path)))
FileCallback(Path);
else if ((E->d_type == DT_DIR ||
(E->d_type == DT_UNKNOWN && IsDirectory(Path))) &&
*E->d_name != '.')
IterateDirRecursive(Path, DirPreCallback, DirPostCallback, FileCallback);
}
closedir(D);
DirPostCallback(Dir);
}
char GetSeparator() {
return '/';
}
bool IsSeparator(char C) {
return C == '/';
}
FILE* OpenFile(int Fd, const char* Mode) {
return fdopen(Fd, Mode);
}
int CloseFile(int fd) {
return close(fd);
}
int DuplicateFile(int Fd) {
return dup(Fd);
}
void RemoveFile(const std::string &Path) {
unlink(Path.c_str());
}
void RenameFile(const std::string &OldPath, const std::string &NewPath) {
rename(OldPath.c_str(), NewPath.c_str());
}
intptr_t GetHandleFromFd(int fd) {
return static_cast<intptr_t>(fd);
}
std::string DirName(const std::string &FileName) {
char *Tmp = new char[FileName.size() + 1];
memcpy(Tmp, FileName.c_str(), FileName.size() + 1);
std::string Res = dirname(Tmp);
delete [] Tmp;
return Res;
}
std::string TmpDir() {
if (auto Env = getenv("TMPDIR"))
return Env;
return "/tmp";
}
bool IsInterestingCoverageFile(const std::string &FileName) {
if (FileName.find("compiler-rt/lib/") != std::string::npos)
return false; // sanitizer internal.
if (FileName.find("/usr/lib/") != std::string::npos)
return false;
if (FileName.find("/usr/include/") != std::string::npos)
return false;
if (FileName == "<null>")
return false;
return true;
}
void RawPrint(const char *Str) {
write(2, Str, strlen(Str));
}
void MkDir(const std::string &Path) {
mkdir(Path.c_str(), 0700);
}
void RmDir(const std::string &Path) {
rmdir(Path.c_str());
}
const std::string &getDevNull() {
static const std::string devNull = "/dev/null";
return devNull;
}
} // namespace fuzzer
#endif // LIBFUZZER_POSIX