rocksdb/env/env_chroot.cc
mrambacher 1a343bc393 Make ChRootEnv, EncryptedEnv, and TimedEnv into FileSystems (#7968)
Summary:
These classes were wraps of Env that provided only extensions to the FileSystem functionality.  Changed the classes to be FileSystems and the wraps to be of the CompositeEnvWrapper.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7968

Reviewed By: anand1976

Differential Revision: D26900253

Pulled By: mrambacher

fbshipit-source-id: 94001d8024a3c54a1c11adadca2bac66c3af2a77
2021-03-15 19:50:11 -07:00

394 lines
16 KiB
C++

// Copyright (c) 2016-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
#if !defined(ROCKSDB_LITE) && !defined(OS_WIN)
#include "env/env_chroot.h"
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <string>
#include <utility>
#include <vector>
#include "env/composite_env_wrapper.h"
#include "rocksdb/file_system.h"
#include "rocksdb/status.h"
namespace ROCKSDB_NAMESPACE {
namespace {
class ChrootFileSystem : public FileSystemWrapper {
public:
ChrootFileSystem(const std::shared_ptr<FileSystem>& base,
const std::string& chroot_dir)
: FileSystemWrapper(base) {
#if defined(OS_AIX)
char resolvedName[PATH_MAX];
char* real_chroot_dir = realpath(chroot_dir.c_str(), resolvedName);
#else
char* real_chroot_dir = realpath(chroot_dir.c_str(), nullptr);
#endif
// chroot_dir must exist so realpath() returns non-nullptr.
assert(real_chroot_dir != nullptr);
chroot_dir_ = real_chroot_dir;
#if !defined(OS_AIX)
free(real_chroot_dir);
#endif
}
const char* Name() const override { return "ChrootFS"; }
Status RegisterDbPaths(const std::vector<std::string>& paths) override {
std::vector<std::string> encoded_paths;
encoded_paths.reserve(paths.size());
for (auto& path : paths) {
auto status_and_enc_path = EncodePathWithNewBasename(path);
if (!status_and_enc_path.first.ok()) {
return status_and_enc_path.first;
}
encoded_paths.emplace_back(status_and_enc_path.second);
}
return FileSystemWrapper::RegisterDbPaths(encoded_paths);
}
Status UnregisterDbPaths(const std::vector<std::string>& paths) override {
std::vector<std::string> encoded_paths;
encoded_paths.reserve(paths.size());
for (auto& path : paths) {
auto status_and_enc_path = EncodePathWithNewBasename(path);
if (!status_and_enc_path.first.ok()) {
return status_and_enc_path.first;
}
encoded_paths.emplace_back(status_and_enc_path.second);
}
return FileSystemWrapper::UnregisterDbPaths(encoded_paths);
}
IOStatus NewSequentialFile(const std::string& fname,
const FileOptions& options,
std::unique_ptr<FSSequentialFile>* result,
IODebugContext* dbg) override {
auto status_and_enc_path = EncodePathWithNewBasename(fname);
if (!status_and_enc_path.first.ok()) {
return status_and_enc_path.first;
}
return FileSystemWrapper::NewSequentialFile(status_and_enc_path.second,
options, result, dbg);
}
IOStatus NewRandomAccessFile(const std::string& fname,
const FileOptions& options,
std::unique_ptr<FSRandomAccessFile>* result,
IODebugContext* dbg) override {
auto status_and_enc_path = EncodePathWithNewBasename(fname);
if (!status_and_enc_path.first.ok()) {
return status_and_enc_path.first;
}
return FileSystemWrapper::NewRandomAccessFile(status_and_enc_path.second,
options, result, dbg);
}
IOStatus NewWritableFile(const std::string& fname, const FileOptions& options,
std::unique_ptr<FSWritableFile>* result,
IODebugContext* dbg) override {
auto status_and_enc_path = EncodePathWithNewBasename(fname);
if (!status_and_enc_path.first.ok()) {
return status_and_enc_path.first;
}
return FileSystemWrapper::NewWritableFile(status_and_enc_path.second,
options, result, dbg);
}
IOStatus ReuseWritableFile(const std::string& fname,
const std::string& old_fname,
const FileOptions& options,
std::unique_ptr<FSWritableFile>* result,
IODebugContext* dbg) override {
auto status_and_enc_path = EncodePathWithNewBasename(fname);
if (!status_and_enc_path.first.ok()) {
return status_and_enc_path.first;
}
auto status_and_old_enc_path = EncodePath(old_fname);
if (!status_and_old_enc_path.first.ok()) {
return status_and_old_enc_path.first;
}
return FileSystemWrapper::ReuseWritableFile(status_and_old_enc_path.second,
status_and_old_enc_path.second,
options, result, dbg);
}
IOStatus NewRandomRWFile(const std::string& fname, const FileOptions& options,
std::unique_ptr<FSRandomRWFile>* result,
IODebugContext* dbg) override {
auto status_and_enc_path = EncodePathWithNewBasename(fname);
if (!status_and_enc_path.first.ok()) {
return status_and_enc_path.first;
}
return FileSystemWrapper::NewRandomRWFile(status_and_enc_path.second,
options, result, dbg);
}
IOStatus NewDirectory(const std::string& dir, const IOOptions& options,
std::unique_ptr<FSDirectory>* result,
IODebugContext* dbg) override {
auto status_and_enc_path = EncodePathWithNewBasename(dir);
if (!status_and_enc_path.first.ok()) {
return status_and_enc_path.first;
}
return FileSystemWrapper::NewDirectory(status_and_enc_path.second, options,
result, dbg);
}
IOStatus FileExists(const std::string& fname, const IOOptions& options,
IODebugContext* dbg) override {
auto status_and_enc_path = EncodePathWithNewBasename(fname);
if (!status_and_enc_path.first.ok()) {
return status_and_enc_path.first;
}
return FileSystemWrapper::FileExists(status_and_enc_path.second, options,
dbg);
}
IOStatus GetChildren(const std::string& dir, const IOOptions& options,
std::vector<std::string>* result,
IODebugContext* dbg) override {
auto status_and_enc_path = EncodePath(dir);
if (!status_and_enc_path.first.ok()) {
return status_and_enc_path.first;
}
return FileSystemWrapper::GetChildren(status_and_enc_path.second, options,
result, dbg);
}
IOStatus GetChildrenFileAttributes(const std::string& dir,
const IOOptions& options,
std::vector<FileAttributes>* result,
IODebugContext* dbg) override {
auto status_and_enc_path = EncodePath(dir);
if (!status_and_enc_path.first.ok()) {
return status_and_enc_path.first;
}
return FileSystemWrapper::GetChildrenFileAttributes(
status_and_enc_path.second, options, result, dbg);
}
IOStatus DeleteFile(const std::string& fname, const IOOptions& options,
IODebugContext* dbg) override {
auto status_and_enc_path = EncodePath(fname);
if (!status_and_enc_path.first.ok()) {
return status_and_enc_path.first;
}
return FileSystemWrapper::DeleteFile(status_and_enc_path.second, options,
dbg);
}
IOStatus CreateDir(const std::string& dirname, const IOOptions& options,
IODebugContext* dbg) override {
auto status_and_enc_path = EncodePathWithNewBasename(dirname);
if (!status_and_enc_path.first.ok()) {
return status_and_enc_path.first;
}
return FileSystemWrapper::CreateDir(status_and_enc_path.second, options,
dbg);
}
IOStatus CreateDirIfMissing(const std::string& dirname,
const IOOptions& options,
IODebugContext* dbg) override {
auto status_and_enc_path = EncodePathWithNewBasename(dirname);
if (!status_and_enc_path.first.ok()) {
return status_and_enc_path.first;
}
return FileSystemWrapper::CreateDirIfMissing(status_and_enc_path.second,
options, dbg);
}
IOStatus DeleteDir(const std::string& dirname, const IOOptions& options,
IODebugContext* dbg) override {
auto status_and_enc_path = EncodePath(dirname);
if (!status_and_enc_path.first.ok()) {
return status_and_enc_path.first;
}
return FileSystemWrapper::DeleteDir(status_and_enc_path.second, options,
dbg);
}
IOStatus GetFileSize(const std::string& fname, const IOOptions& options,
uint64_t* file_size, IODebugContext* dbg) override {
auto status_and_enc_path = EncodePath(fname);
if (!status_and_enc_path.first.ok()) {
return status_and_enc_path.first;
}
return FileSystemWrapper::GetFileSize(status_and_enc_path.second, options,
file_size, dbg);
}
IOStatus GetFileModificationTime(const std::string& fname,
const IOOptions& options,
uint64_t* file_mtime,
IODebugContext* dbg) override {
auto status_and_enc_path = EncodePath(fname);
if (!status_and_enc_path.first.ok()) {
return status_and_enc_path.first;
}
return FileSystemWrapper::GetFileModificationTime(
status_and_enc_path.second, options, file_mtime, dbg);
}
IOStatus RenameFile(const std::string& src, const std::string& dest,
const IOOptions& options, IODebugContext* dbg) override {
auto status_and_src_enc_path = EncodePath(src);
if (!status_and_src_enc_path.first.ok()) {
return status_and_src_enc_path.first;
}
auto status_and_dest_enc_path = EncodePathWithNewBasename(dest);
if (!status_and_dest_enc_path.first.ok()) {
return status_and_dest_enc_path.first;
}
return FileSystemWrapper::RenameFile(status_and_src_enc_path.second,
status_and_dest_enc_path.second,
options, dbg);
}
IOStatus LinkFile(const std::string& src, const std::string& dest,
const IOOptions& options, IODebugContext* dbg) override {
auto status_and_src_enc_path = EncodePath(src);
if (!status_and_src_enc_path.first.ok()) {
return status_and_src_enc_path.first;
}
auto status_and_dest_enc_path = EncodePathWithNewBasename(dest);
if (!status_and_dest_enc_path.first.ok()) {
return status_and_dest_enc_path.first;
}
return FileSystemWrapper::LinkFile(status_and_src_enc_path.second,
status_and_dest_enc_path.second, options,
dbg);
}
IOStatus LockFile(const std::string& fname, const IOOptions& options,
FileLock** lock, IODebugContext* dbg) override {
auto status_and_enc_path = EncodePathWithNewBasename(fname);
if (!status_and_enc_path.first.ok()) {
return status_and_enc_path.first;
}
// FileLock subclasses may store path (e.g., PosixFileLock stores it). We
// can skip stripping the chroot directory from this path because callers
// shouldn't use it.
return FileSystemWrapper::LockFile(status_and_enc_path.second, options,
lock, dbg);
}
IOStatus GetTestDirectory(const IOOptions& options, std::string* path,
IODebugContext* dbg) override {
// Adapted from PosixEnv's implementation since it doesn't provide a way to
// create directory in the chroot.
char buf[256];
snprintf(buf, sizeof(buf), "/rocksdbtest-%d", static_cast<int>(geteuid()));
*path = buf;
// Directory may already exist, so ignore return
return CreateDirIfMissing(*path, options, dbg);
}
IOStatus NewLogger(const std::string& fname, const IOOptions& options,
std::shared_ptr<Logger>* result,
IODebugContext* dbg) override {
auto status_and_enc_path = EncodePathWithNewBasename(fname);
if (!status_and_enc_path.first.ok()) {
return status_and_enc_path.first;
}
return FileSystemWrapper::NewLogger(status_and_enc_path.second, options,
result, dbg);
}
IOStatus GetAbsolutePath(const std::string& db_path, const IOOptions& options,
std::string* output_path,
IODebugContext* dbg) override {
auto status_and_enc_path = EncodePath(db_path);
if (!status_and_enc_path.first.ok()) {
return status_and_enc_path.first;
}
return FileSystemWrapper::GetAbsolutePath(status_and_enc_path.second,
options, output_path, dbg);
}
private:
// Returns status and expanded absolute path including the chroot directory.
// Checks whether the provided path breaks out of the chroot. If it returns
// non-OK status, the returned path should not be used.
std::pair<IOStatus, std::string> EncodePath(const std::string& path) {
if (path.empty() || path[0] != '/') {
return {IOStatus::InvalidArgument(path, "Not an absolute path"), ""};
}
std::pair<IOStatus, std::string> res;
res.second = chroot_dir_ + path;
#if defined(OS_AIX)
char resolvedName[PATH_MAX];
char* normalized_path = realpath(res.second.c_str(), resolvedName);
#else
char* normalized_path = realpath(res.second.c_str(), nullptr);
#endif
if (normalized_path == nullptr) {
res.first = IOStatus::NotFound(res.second, strerror(errno));
} else if (strlen(normalized_path) < chroot_dir_.size() ||
strncmp(normalized_path, chroot_dir_.c_str(),
chroot_dir_.size()) != 0) {
res.first = IOStatus::IOError(res.second,
"Attempted to access path outside chroot");
} else {
res.first = IOStatus::OK();
}
#if !defined(OS_AIX)
free(normalized_path);
#endif
return res;
}
// Similar to EncodePath() except assumes the basename in the path hasn't been
// created yet.
std::pair<IOStatus, std::string> EncodePathWithNewBasename(
const std::string& path) {
if (path.empty() || path[0] != '/') {
return {IOStatus::InvalidArgument(path, "Not an absolute path"), ""};
}
// Basename may be followed by trailing slashes
size_t final_idx = path.find_last_not_of('/');
if (final_idx == std::string::npos) {
// It's only slashes so no basename to extract
return EncodePath(path);
}
// Pull off the basename temporarily since realname(3) (used by
// EncodePath()) requires a path that exists
size_t base_sep = path.rfind('/', final_idx);
auto status_and_enc_path = EncodePath(path.substr(0, base_sep + 1));
status_and_enc_path.second.append(path.substr(base_sep + 1));
return status_and_enc_path;
}
std::string chroot_dir_;
};
} // namespace
std::shared_ptr<FileSystem> NewChrootFileSystem(
const std::shared_ptr<FileSystem>& base, const std::string& chroot_dir) {
return std::make_shared<ChrootFileSystem>(base, chroot_dir);
}
Env* NewChrootEnv(Env* base_env, const std::string& chroot_dir) {
if (!base_env->FileExists(chroot_dir).ok()) {
return nullptr;
}
std::shared_ptr<FileSystem> chroot_fs =
NewChrootFileSystem(base_env->GetFileSystem(), chroot_dir);
return new CompositeEnvWrapper(base_env, chroot_fs);
}
} // namespace ROCKSDB_NAMESPACE
#endif // !defined(ROCKSDB_LITE) && !defined(OS_WIN)