/*
 * Copyright (C) 2017 The Android Open Source Project
 *
 * 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
 *
 *      http://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.
 */

syntax = "proto2";

package perfetto.protos;

message IPCFrame {
  // Client -> Host.
  message BindService {
    optional string service_name = 1;
  }

  // Host -> Client.
  message BindServiceReply {
    message MethodInfo {
      optional uint32 id = 1;
      optional string name = 2;
    }
    optional bool success = 1;
    optional uint32 service_id = 2;
    repeated MethodInfo methods = 3;
  }

  // Client -> Host.
  message InvokeMethod {
    // BindServiceReply.id.
    optional uint32 service_id = 1;

    // BindServiceReply.method.id.
    optional uint32 method_id = 2;

    // Proto-encoded request argument.
    optional bytes args_proto = 3;

    // When true the client specifies that a reply is not needed. The use case
    // is a method with an empty, where the client doesn't care about the
    // success/failure of the method invocation and rather prefers avoiding the
    // IPC roundtrip + context switch associated with the reply.
    optional bool drop_reply = 4;
  }

  // Host -> Client.
  message InvokeMethodReply {
    optional bool success = 1;

    // only for streaming RPCs.
    optional bool has_more = 2;

    // proto-encoded response value.
    optional bytes reply_proto = 3;
  }

  // Host -> Client.
  message RequestError {
    optional string error = 1;
  }

  // Client (relay service) -> Host. This is generated by the relay service to
  // fill the producer identity in the guest. This message is sent to the host
  // service *before* any IPCFrame is from a local producer is relayed. This is
  // accepted only on AF_VSOCK and AF_INET sockets, where we cannot validate the
  // endpoont of the connection. for AF_UNIX sockets, this is ignored and traced
  // uses instead the SO_PEERCRED.
  message SetPeerIdentity {
    // The UID and PID of the producer process.
    optional int32 pid = 1;
    optional int32 uid = 2;

    // The hint for the tracing service to infer the machine ID. This field
    // should satisfy the requriement that different machines should have
    // different values. In practice, this filed contains the Linux kernel
    // boot_id, or a hash of kernel bootup timestamp and uname(2) if boot_id
    // isn't available.
    optional string machine_id_hint = 3;
  }

  // The client is expected to send requests with monotonically increasing
  // request_id. The host will match the request_id sent from the client.
  // In the case of a Streaming response (has_more = true) the host will send
  // several InvokeMethodReply with the same request_id.
  optional uint64 request_id = 2;

  oneof msg {
    BindService msg_bind_service = 3;
    BindServiceReply msg_bind_service_reply = 4;
    InvokeMethod msg_invoke_method = 5;
    InvokeMethodReply msg_invoke_method_reply = 6;
    RequestError msg_request_error = 7;
    SetPeerIdentity set_peer_identity = 8;
  }

  // Used only in unittests to generate a parsable message of arbitrary size.
  repeated bytes data_for_testing = 1;
};
