src/traced_relay/relay_service_main.cc

/*
 * Copyright (C) 2023 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.
 */

#include "perfetto/ext/base/file_utils.h"
#include "perfetto/ext/base/getopt.h"
#include "perfetto/ext/base/string_utils.h"
#include "perfetto/ext/base/unix_task_runner.h"
#include "perfetto/ext/base/version.h"
#include "perfetto/ext/base/watchdog.h"
#include "perfetto/ext/traced/traced.h"
#include "perfetto/tracing/default_socket.h"
#include "src/traced_relay/relay_service.h"

namespace perfetto {
namespace {
void PrintUsage(const char* prog_name) {
  fprintf(stderr, R"(
Usage: %s [option] ...
Options and arguments
    --background : Exits immediately and continues running in the background
    --version : print the version number and exit.
    --set-socket-permissions <permissions> : sets group ownership and permission
        mode bits of the listening socket.
        <permissions> format: <prod_group>:<prod_mode>,
        where <prod_group> is the group name for chgrp the listening socket,
        <prod_mode> is the mode bits (e.g. 0660) for chmod the producer socket,

Example:
    %s --set-socket-permissions traced-producer:0660 starts the service and sets
    the group ownership of the listening socket to "traced-producer". The
    listening socket is chmod with 0660 (rw-rw----) mode bits. )",
          prog_name, prog_name);
}

}  // namespace

static int RelayServiceMain(int argc, char** argv) {
  enum LongOption {
    OPT_VERSION = 1000,
    OPT_SET_SOCKET_PERMISSIONS = 1001,
    OPT_BACKGROUND,
  };

  bool background = false;

  static const option long_options[] = {
      {"background", no_argument, nullptr, OPT_BACKGROUND},
      {"version", no_argument, nullptr, OPT_VERSION},
      {"set-socket-permissions", required_argument, nullptr,
       OPT_SET_SOCKET_PERMISSIONS},
      {nullptr, 0, nullptr, 0}};

  std::string listen_socket_group, consumer_socket_group,
      listen_socket_mode_bits, consumer_socket_mode;

  for (;;) {
    int option = getopt_long(argc, argv, "", long_options, nullptr);
    if (option == -1)
      break;
    switch (option) {
      case OPT_BACKGROUND:
        background = true;
        break;
      case OPT_VERSION:
        printf("%s\n", base::GetVersionString());
        return 0;
      case OPT_SET_SOCKET_PERMISSIONS: {
        // Check that the socket permission argument is well formed.
        auto parts = perfetto::base::SplitString(std::string(optarg), ":");
        PERFETTO_CHECK(parts.size() == 2);
        PERFETTO_CHECK(
            std::all_of(parts.cbegin(), parts.cend(),
                        [](const std::string& part) { return !part.empty(); }));
        listen_socket_group = parts[0];
        listen_socket_mode_bits = parts[1];
        break;
      }
      default:
        PrintUsage(argv[0]);
        return 1;
    }
  }

  if (background) {
    base::Daemonize([] { return 0; });
  }

  auto listen_socket = GetProducerSocket();
  remove(listen_socket);
  if (!listen_socket_group.empty()) {
    auto status = base::SetFilePermissions(listen_socket, listen_socket_group,
                                           listen_socket_mode_bits);
    if (!status.ok()) {
      PERFETTO_ELOG("Failed to set socket permissions: %s", status.c_message());
      return 1;
    }
  }

  base::UnixTaskRunner task_runner;
  auto svc = std::make_unique<RelayService>(&task_runner);
  svc->Start(listen_socket, GetRelaySocket());

  // Set the CPU limit and start the watchdog running. The memory limit will
  // be set inside the service code as it relies on the size of buffers.
  // The CPU limit is the generic one defined in watchdog.h.
  base::Watchdog* watchdog = base::Watchdog::GetInstance();
  watchdog->SetCpuLimit(base::kWatchdogDefaultCpuLimit,
                        base::kWatchdogDefaultCpuWindow);
  watchdog->Start();

  PERFETTO_ILOG("Started traced_relay, listening on %s, forwarding to %s",
                GetProducerSocket(), GetRelaySocket());

  task_runner.Run();
  return 0;
}
}  // namespace perfetto

int main(int argc, char** argv) {
  return perfetto::RelayServiceMain(argc, argv);
}