sandboxed-api/sandboxed_api/var_proto.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.
// Provides a class to marshall protobufs in and out of the sandbox
#ifndef SANDBOXED_API_VAR_PROTO_H_
#define SANDBOXED_API_VAR_PROTO_H_
#include <cinttypes>
#include <cstdint>
#include <ctime>
#include <memory>
#include <string>
#include <type_traits>
#include <utility>
#include <vector>
#include "absl/base/attributes.h"
#include "absl/base/macros.h"
#include "absl/log/log.h"
#include "absl/status/status.h"
#include "absl/status/statusor.h"
#include "absl/utility/utility.h"
#include "sandboxed_api/proto_helper.h"
#include "sandboxed_api/util/status_macros.h"
#include "sandboxed_api/var_lenval.h"
#include "sandboxed_api/var_ptr.h"
namespace sapi::v {
template <typename T>
class Proto : public Var {
public:
class PrivateToken {
private:
explicit PrivateToken() = default;
friend class Proto;
};
static_assert(std::is_base_of<google::protobuf::MessageLite, T>::value,
"Template argument must be a proto message");
Proto(PrivateToken, std::vector<uint8_t> data)
: wrapped_var_(std::move(data)) {}
ABSL_DEPRECATED("Use Proto<>::FromMessage() instead")
explicit Proto(const T& proto)
: wrapped_var_(SerializeProto(proto).value()) {}
static absl::StatusOr<Proto<T>> FromMessage(const T& proto) {
SAPI_ASSIGN_OR_RETURN(std::vector<uint8_t> len_val, SerializeProto(proto));
return absl::StatusOr<Proto<T>>(absl::in_place, PrivateToken{},
std::move(len_val));
}
size_t GetSize() const final { return wrapped_var_.GetSize(); }
Type GetType() const final { return Type::kProto; }
std::string GetTypeString() const final { return "Protobuf"; }
std::string ToString() const final { return "Protobuf"; }
void* GetRemote() const override { return wrapped_var_.GetRemote(); }
void* GetLocal() const override { return wrapped_var_.GetLocal(); }
// Returns a copy of the stored protobuf object.
absl::StatusOr<T> GetMessage() const {
return DeserializeProto<T>(
reinterpret_cast<const char*>(wrapped_var_.GetData()),
wrapped_var_.GetDataSize());
}
ABSL_DEPRECATED("Use GetMessage() instead")
std::unique_ptr<T> GetProtoCopy() const {
if (auto proto = GetMessage(); proto.ok()) {
return std::make_unique<T>(*std::move(proto));
}
return nullptr;
}
void SetRemote(void* /* remote */) override {
// We do not support that much indirection (pointer to a pointer to a
// protobuf) as it is unlikely that this is wanted behavior. If you expect
// this to work, please get in touch with us.
LOG(FATAL) << "SetRemote not supported on protobufs.";
}
protected:
// Forward a couple of function calls to the actual var.
absl::Status Allocate(RPCChannel* rpc_channel, bool automatic_free) override {
return wrapped_var_.Allocate(rpc_channel, automatic_free);
}
absl::Status Free(RPCChannel* rpc_channel) override {
return absl::OkStatus();
}
absl::Status TransferToSandboxee(RPCChannel* rpc_channel,
pid_t pid) override {
return wrapped_var_.TransferToSandboxee(rpc_channel, pid);
}
absl::Status TransferFromSandboxee(RPCChannel* rpc_channel,
pid_t pid) override {
return wrapped_var_.TransferFromSandboxee(rpc_channel, pid);
}
private:
// The management of reading/writing the data to the sandboxee is handled by
// the LenVal class.
LenVal wrapped_var_;
};
} // namespace sapi::v
#endif // SANDBOXED_API_VAR_PROTO_H_