rocksdb/env/env_chroot.cc

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)