text: // Copyright (c) 2012 The Chromium Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  #include "chrome/browser/devtools/remote_debugging_server.h"
  
  #include <utility>
  
  #include "base/command_line.h"
  #include "base/lazy_instance.h"
  #include "base/macros.h"
  #include "base/path_service.h"
  #include "base/strings/string_number_conversions.h"
  #include "chrome/browser/browser_process.h"
  #include "chrome/browser/devtools/chrome_devtools_manager_delegate.h"
  #include "chrome/browser/devtools/devtools_window.h"
  #include "chrome/browser/profiles/profile.h"
  #include "chrome/browser/ui/browser.h"
  #include "chrome/browser/ui/browser_list.h"
  #include "chrome/common/chrome_paths.h"
  #include "chrome/common/chrome_switches.h"
  #include "content/public/browser/devtools_agent_host.h"
  #include "content/public/browser/devtools_socket_factory.h"
  #include "content/public/common/content_switches.h"
  #include "net/base/filename_util.h"
  #include "net/base/net_errors.h"
  #include "net/log/net_log_source.h"
  #include "net/socket/tcp_server_socket.h"
  #include "third_party/blink/public/public_buildflags.h"
  #include "ui/base/resource/resource_bundle.h"
  
  namespace {
  
  base::LazyInstance<bool>::Leaky g_tethering_enabled = LAZY_INSTANCE_INITIALIZER;
  
  const uint16_t kMinTetheringPort = 9333;
  const uint16_t kMaxTetheringPort = 9444;
  const int kBackLog = 10;
  
  class TCPServerSocketFactory
      : public content::DevToolsSocketFactory {
   public:
    explicit TCPServerSocketFactory(uint16_t port)
        : port_(port), last_tethering_port_(kMinTetheringPort) {}
  
    TCPServerSocketFactory(const TCPServerSocketFactory&) = delete;
    TCPServerSocketFactory& operator=(const TCPServerSocketFactory&) = delete;
  
   private:
    std::unique_ptr<net::ServerSocket> CreateLocalHostServerSocket(int port) {
      std::unique_ptr<net::ServerSocket> socket(
          new net::TCPServerSocket(nullptr, net::NetLogSource()));
      if (socket->ListenWithAddressAndPort(
              "127.0.0.1", port, kBackLog) == net::OK)
        return socket;
      if (socket->ListenWithAddressAndPort("::1", port, kBackLog) == net::OK)
        return socket;
      return nullptr;
    }
  
    // content::DevToolsSocketFactory.
    std::unique_ptr<net::ServerSocket> CreateForHttpServer() override {
      std::unique_ptr<net::ServerSocket> socket(
          new net::TCPServerSocket(nullptr, net::NetLogSource()));
      return CreateLocalHostServerSocket(port_);
    }
  
    std::unique_ptr<net::ServerSocket> CreateForTethering(
        std::string* name) override {
      if (!g_tethering_enabled.Get())
        return nullptr;
  
      if (last_tethering_port_ == kMaxTetheringPort)
        last_tethering_port_ = kMinTetheringPort;
      uint16_t port = ++last_tethering_port_;
      *name = base::NumberToString(port);
      return CreateLocalHostServerSocket(port);
    }
  
    std::string address_;
    uint16_t port_;
    uint16_t last_tethering_port_;
  };
  
  }  // namespace
  
  // static
  void RemoteDebuggingServer::EnableTetheringForDebug() {
    g_tethering_enabled.Get() = true;
  }
  
  RemoteDebuggingServer::RemoteDebuggingServer() {
    const base::CommandLine& command_line =
        *base::CommandLine::ForCurrentProcess();
    if (command_line.HasSwitch(switches::kRemoteDebuggingPipe)) {
      content::DevToolsAgentHost::StartRemoteDebuggingPipeHandler(
          base::BindOnce(&ChromeDevToolsManagerDelegate::CloseBrowserSoon));
    }
  
    std::string port_str =
        command_line.GetSwitchValueASCII(::switches::kRemoteDebuggingPort);
    int port;
    if (!base::StringToInt(port_str, &port) || port < 0 || port >= 65535)
      return;
  
    base::FilePath output_dir;
    if (!port) {
      // The client requested an ephemeral port. Must write the selected
      // port to a well-known location in the profile directory to
      // bootstrap the connection process.
      bool result = base::PathService::Get(chrome::DIR_USER_DATA, &output_dir);
      DCHECK(result);
    }
  
    base::FilePath debug_frontend_dir;
    if (command_line.HasSwitch(::switches::kCustomDevtoolsFrontend)) {
      GURL custom_devtools_frontend_url(command_line.GetSwitchValueASCII(
          ::switches::kCustomDevtoolsFrontend));
      if (custom_devtools_frontend_url.SchemeIsFile()) {
        net::FileURLToFilePath(custom_devtools_frontend_url, &debug_frontend_dir);
      }
    }
    content::DevToolsAgentHost::StartRemoteDebuggingServer(
        std::make_unique<TCPServerSocketFactory>(port), output_dir,
        debug_frontend_dir);
  }
  
  RemoteDebuggingServer::~RemoteDebuggingServer() {
    // Ensure Profile is alive, because the whole DevTools subsystem
    // accesses it during shutdown.
    DCHECK(g_browser_process->profile_manager());
    content::DevToolsAgentHost::StopRemoteDebuggingServer();
    content::DevToolsAgentHost::StopRemoteDebuggingPipeHandler();
  }
  