// Copyright 2017 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

syntax = "proto3";

option cc_enable_arenas = true;
option optimize_for = LITE_RUNTIME;

package vm_tools.vsh;

// Indicates the status of a connection.
enum ConnectionStatus {
  // Connection status is unknown.
  UNKNOWN = 0;
  // Connection was set up successfully. Server and client may now exchange
  // messages.
  READY = 1;
  // The server's target program has exited. The server will immediately close
  // the connection, and the client is expected to exit after its cleanup.
  EXITED = 2;
  // A fatal error was encountered. The connection will be closed.
  FAILED = 3;
}

// Request to set up a connection to a container. This must be the first
// message sent to the server from the client.
message SetupConnectionRequest {
  // Target container. "vm_shell" is a special value to get a VM shell.
  string target = 1;
  // User to execute the target program.
  string user = 2;
  // Map of environment variables to forward.
  map<string, string> env = 3;
  // Deprecated. Target command. Empty indicates a login shell.
  string command = 4;
  // Argv of the target program to run. Empty indicates a login shell.
  repeated string argv = 5;
  // Initial window size (rows) of the pty.
  int32 window_rows = 6;
  // Initial window size (cols) of the pty.
  int32 window_cols = 7;
  // True if using a noninteractive client and a pty should not be allocated.
  // The logic here is inverted to keep backwards compatibility with the
  // current behavior (always allocate a pty).
  bool nopty = 8;
  // Optional: directory to set for current working directory.
  string cwd = 9;
  // Optional: use /proc/<cwd_pid>/cwd for current working directory.
  int32 cwd_pid = 10;
}

// Response to a SetupConnectionRequest.
message SetupConnectionResponse {
  // Status of the connection.
  ConnectionStatus status = 1;
  // Short description of any error encountered when setting up the
  // connection.
  string description = 2;
  // Process ID of new shell.
  int32 pid = 3;
}

// A message that indicates to either the server or the client a change
// in connection status.
message ConnectionStatusMessage {
  // New connection status. If the connection status is changed to anything
  // except READY, the recipient must shut down.
  ConnectionStatus status = 1;
  // Short description of any error that triggered the status change.
  string description = 2;
  // Return code of the command, if any.
  sint32 code = 3;
}

// Type of stdio stream that is being sent.
enum StdioStream {
  // The stream is invalid.
  INVALID_STREAM = 0;
  // This is a stdin stream, flowing from client to server.
  STDIN_STREAM = 1;
  // This is a stdout stream, flowing from server to client.
  STDOUT_STREAM = 2;
  // This is a stderr stream, flowing from server to client.
  STDERR_STREAM = 3;
}

// DataMessages encapsulate stdio to be forwarded between the server and client.
message DataMessage {
  // Type of stream in this message.
  StdioStream stream = 1;
  // Data to be forwarded.
  bytes data = 2;
}

// Indicates that the server should resize its pseudoterminal to the given
// dimensions. Sent by the client in response to SIGWINCH.
message WindowResizeMessage {
  // New number of rows for the tty.
  int32 rows = 1;
  // New number of cols for the tty.
  int32 cols = 2;
}

// Encapsulates a POSIX signal to be sent to the target program.
enum Signal {
  SIGNAL_UNKNOWN = 0;
  SIGNAL_HUP = 1;
  SIGNAL_INT = 2;
  SIGNAL_QUIT = 3;
  SIGNAL_TERM = 15;
}

// Wrapper message for all messages that can be sent to the host/client.
message HostMessage {
  oneof msg {
    DataMessage data_message = 1;
    ConnectionStatusMessage status_message = 2;
  }
}

// Wrapper message for all messages that can be sent to the guest/server.
message GuestMessage {
  oneof msg {
    DataMessage data_message = 1;
    ConnectionStatusMessage status_message = 2;
    WindowResizeMessage resize_message = 3;
    Signal signal = 4;
  }
}