1 // Copyright 2019 Google LLC 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // https://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 // Provides a class to marshall protobufs in and out of the sandbox 16 17 #ifndef SANDBOXED_API_VAR_PROTO_H_ 18 #define SANDBOXED_API_VAR_PROTO_H_ 19 20 #include <cstdint> 21 #include <ctime> 22 #include <memory> 23 #include <string> 24 #include <type_traits> 25 #include <utility> 26 #include <vector> 27 28 #include "absl/base/attributes.h" 29 #include "absl/log/check.h" 30 #include "absl/log/log.h" 31 #include "absl/status/status.h" 32 #include "absl/status/statusor.h" 33 #include "absl/utility/utility.h" 34 #include "google/protobuf/message_lite.h" 35 #include "sandboxed_api/rpcchannel.h" 36 #include "sandboxed_api/util/proto_helper.h" 37 #include "sandboxed_api/util/status_macros.h" 38 #include "sandboxed_api/var_abstract.h" 39 #include "sandboxed_api/var_lenval.h" 40 #include "sandboxed_api/var_type.h" 41 42 namespace sapi::v { 43 44 template <typename T> 45 class Proto : public Var { 46 public: 47 class PrivateToken { 48 private: 49 explicit PrivateToken() = default; 50 friend class Proto; 51 }; 52 53 static_assert(std::is_base_of<google::protobuf::MessageLite, T>::value, 54 "Template argument must be a proto message"); 55 Proto()56 Proto() : wrapped_var_(SerializeProto(T{}).value()) {} 57 Proto(PrivateToken,std::vector<uint8_t> data)58 Proto(PrivateToken, std::vector<uint8_t> data) 59 : wrapped_var_(std::move(data)) {} 60 61 ABSL_DEPRECATED("Use Proto<>::FromMessage() instead") Proto(const T & proto)62 explicit Proto(const T& proto) 63 : wrapped_var_(SerializeProto(proto).value()) {} 64 65 Proto(Proto&& other) = default; 66 Proto& operator=(Proto&& other) = default; 67 FromMessage(const T & proto)68 static absl::StatusOr<Proto<T>> FromMessage(const T& proto) { 69 SAPI_ASSIGN_OR_RETURN(std::vector<uint8_t> len_val, SerializeProto(proto)); 70 return absl::StatusOr<Proto<T>>(absl::in_place, PrivateToken{}, 71 std::move(len_val)); 72 } 73 GetSize()74 size_t GetSize() const final { return wrapped_var_.GetSize(); } GetType()75 Type GetType() const final { return Type::kProto; } GetTypeString()76 std::string GetTypeString() const final { return "Protobuf"; } ToString()77 std::string ToString() const final { return "Protobuf"; } 78 GetRemote()79 void* GetRemote() const override { return wrapped_var_.GetRemote(); } GetLocal()80 void* GetLocal() const override { return wrapped_var_.GetLocal(); } 81 82 // Returns a copy of the stored protobuf object. GetMessage()83 absl::StatusOr<T> GetMessage() const { 84 return DeserializeProto<T>( 85 reinterpret_cast<const char*>(wrapped_var_.GetData()), 86 wrapped_var_.GetDataSize()); 87 } 88 89 ABSL_DEPRECATED("Use GetMessage() instead") GetProtoCopy()90 std::unique_ptr<T> GetProtoCopy() const { 91 if (auto proto = GetMessage(); proto.ok()) { 92 return std::make_unique<T>(*std::move(proto)); 93 } 94 return nullptr; 95 } 96 SetRemote(void *)97 void SetRemote(void* /* remote */) override { 98 // We do not support that much indirection (pointer to a pointer to a 99 // protobuf) as it is unlikely that this is wanted behavior. If you expect 100 // this to work, please get in touch with us. 101 LOG(FATAL) << "SetRemote not supported on protobufs."; 102 } 103 104 protected: 105 // Forward a couple of function calls to the actual var. Allocate(RPCChannel * rpc_channel,bool automatic_free)106 absl::Status Allocate(RPCChannel* rpc_channel, bool automatic_free) override { 107 return wrapped_var_.Allocate(rpc_channel, automatic_free); 108 } 109 Free(RPCChannel * rpc_channel)110 absl::Status Free(RPCChannel* rpc_channel) override { 111 return absl::OkStatus(); 112 } 113 TransferToSandboxee(RPCChannel * rpc_channel,pid_t pid)114 absl::Status TransferToSandboxee(RPCChannel* rpc_channel, 115 pid_t pid) override { 116 return wrapped_var_.TransferToSandboxee(rpc_channel, pid); 117 } 118 TransferFromSandboxee(RPCChannel * rpc_channel,pid_t pid)119 absl::Status TransferFromSandboxee(RPCChannel* rpc_channel, 120 pid_t pid) override { 121 return wrapped_var_.TransferFromSandboxee(rpc_channel, pid); 122 } 123 124 private: 125 // The management of reading/writing the data to the sandboxee is handled by 126 // the LenVal class. 127 LenVal wrapped_var_; 128 }; 129 130 } // namespace sapi::v 131 132 #endif // SANDBOXED_API_VAR_PROTO_H_ 133