sandboxed-api/sandboxed_api/sandbox2/mounts.h

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// Copyright 2019 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef SANDBOXED_API_SANDBOX2_MOUNTTREE_H_
#define SANDBOXED_API_SANDBOX2_MOUNTTREE_H_
#include <cstddef>
#include <string>
#include <utility>
#include <vector>
#include "absl/status/status.h"
#include "absl/status/statusor.h"
#include "absl/strings/string_view.h"
#include "sandboxed_api/sandbox2/mount_tree.pb.h"
namespace sandbox2 {
namespace internal {
bool IsSameFile(const std::string& path1, const std::string& path2);
bool IsWritable(const MountTree::Node& node);
bool HasSameTarget(const MountTree::Node& n1, const MountTree::Node& n2);
bool IsEquivalentNode(const MountTree::Node& n1, const MountTree::Node& n2);
} // namespace internal
class Mounts {
public:
Mounts() {
MountTree::Node root;
root.mutable_root_node()->set_writable(false);
*mount_tree_.mutable_node() = root;
}
explicit Mounts(MountTree mount_tree) : mount_tree_(std::move(mount_tree)) {}
Mounts(const Mounts&) = default;
Mounts(Mounts&&) = default;
Mounts& operator=(const Mounts&) = default;
Mounts& operator=(Mounts&&) = default;
absl::Status AddFile(absl::string_view path, bool is_ro = true) {
return AddFileAt(path, path, is_ro);
}
absl::Status AddFileAt(absl::string_view outside, absl::string_view inside,
bool is_ro = true);
absl::Status AddDirectory(absl::string_view path, bool is_ro = true) {
return AddDirectoryAt(path, path, is_ro);
}
absl::Status AddDirectoryAt(absl::string_view outside,
absl::string_view inside, bool is_ro = true);
absl::Status AddMappingsForBinary(const std::string& path,
absl::string_view ld_library_path = {});
absl::Status AddTmpfs(absl::string_view inside, size_t sz);
absl::Status Remove(absl::string_view path);
void CreateMounts(const std::string& root_path) const;
MountTree GetMountTree() const { return mount_tree_; }
void SetRootWritable() {
mount_tree_.mutable_node()->mutable_root_node()->set_writable(true);
}
bool IsRootReadOnly() const {
return mount_tree_.has_node() && mount_tree_.node().has_root_node() &&
!mount_tree_.node().root_node().writable();
}
// Lists the outside and inside entries of the input tree in the output
// parameters, in an ls-like manner. Each entry is traversed in the
// depth-first order. However, the entries on the same level of hierarchy are
// traversed in their natural order in the tree. The elements in the output
// containers match each other pairwise: outside_entries[i] is mounted as
// inside_entries[i]. The elements of inside_entries are prefixed with either
// 'R' (read-only) or 'W' (writable).
void RecursivelyListMounts(std::vector<std::string>* outside_entries,
std::vector<std::string>* inside_entries) const;
absl::StatusOr<std::string> ResolvePath(absl::string_view path) const;
private:
friend class MountTreeTest;
absl::Status Insert(absl::string_view path, const MountTree::Node& node);
MountTree mount_tree_;
};
} // namespace sandbox2
#endif // SANDBOXED_API_SANDBOX2_MOUNTTREE_H_