[Chromoting] Add a Linux command-line app that can register and start a host.

remoting/host/setup/start_host.cc

Index: remoting/host/setup/start_host.cc
diff --git a/remoting/host/setup/start_host.cc b/remoting/host/setup/start_host.cc
new file mode 100644
index 0000000000000000000000000000000000000000..0a0b6ea5ca4b8013fed85c86a44a7a5bc16e9356
--- /dev/null
+++ b/remoting/host/setup/start_host.cc
@@ -0,0 +1,135 @@
+// 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.
+

[Sergey Ulanov, 2012/10/15 18:25:30]

add comment to describe what this file is for.

[simonmorris, 2012/10/15 20:49:55]

Done.

+#include <iostream>
+#include <stdio.h>
+#include <termios.h>
+
+#include "base/at_exit.h"
+#include "base/command_line.h"
+#include "base/run_loop.h"
+#include "base/threading/thread.h"
+#include "net/url_request/url_request_context_getter.h"
+#include "remoting/host/setup/host_starter.h"
+#include "remoting/host/setup/pin_validator.h"
+#include "remoting/host/url_request_context.h"
+
+using remoting::HostStarter;
+
+// True if the host could not be started.
+bool fail = true;

[Sergey Ulanov, 2012/10/15 18:25:30]

maybe store exit code for consistency with our Me2Me host code. In either case
you need g_ prefix for global variables.

[simonmorris, 2012/10/15 20:49:55]

I'm not sure an exit code would be useful.

Added a g_ prefix.

+
+// The main message loop.
+MessageLoop* message_loop = NULL;

[Sergey Ulanov, 2012/10/15 18:25:30]

g_message_loop

Or maybe put everything in a class - then you wouldn't need any globals.

[simonmorris, 2012/10/15 20:49:55]

Added a g_ prefix.

+
+// Lets us hide the PIN that a user types.
+void SetEcho(bool echo) {
+  termios term;
+  tcgetattr(STDIN_FILENO, &term);
+  if (echo) {
+    term.c_lflag |= ECHO;
+  } else {
+    term.c_lflag &= ~ECHO;
+  }
+  tcsetattr(STDIN_FILENO, TCSANOW, &term);
+}
+
+// Called when the HostStarter has finished.
+void OnDone(HostStarter::Result result) {
+  if (MessageLoop::current() != message_loop) {
+    message_loop->PostTask(FROM_HERE, base::Bind(&OnDone, result));
+    return;
+  }
+  switch (result) {
+    case HostStarter::START_IN_PROGRESS:
+      fprintf(stderr, "Internal error: START_IN_PROGRESS.\n");
+      break;
+    case HostStarter::START_COMPLETE:
+      fail = false;
+      break;
+    case HostStarter::NETWORK_ERROR:
+      fprintf(stderr, "Couldn't start host: network error.\n");
+      break;
+    case HostStarter::OAUTH_ERROR:
+      fprintf(stderr, "Couldn't start host: OAuth error.\n");
+      break;
+    case HostStarter::START_ERROR:
+      fprintf(stderr, "Couldn't start host.\n");
+      break;
+  }
+
+  message_loop->QuitNow();
+}
+
+int main(int argc, char** argv) {
+  // google_apis::GetOAuth2ClientID/Secret need a static CommandLine.
+  CommandLine::Init(argc, argv);
+  const CommandLine* command_line = CommandLine::ForCurrentProcess();
+
+  std::string host_name = command_line->GetSwitchValueASCII("name");
+  std::string host_pin = command_line->GetSwitchValueASCII("pin");
+  std::string auth_code = command_line->GetSwitchValueASCII("code");
+
+  if (host_name.empty() || auth_code.empty()) {

[Sergey Ulanov, 2012/10/15 18:25:30]

Why hostname is a required parameter?

[Sergey Ulanov, 2012/10/15 18:25:30]

It may not always be secure to pass authentication code in command line. Maybe
ask it in the same you ask for PIN.

[simonmorris, 2012/10/15 20:49:55]

For simplicity. The host has to have a name.

If the command line didn't specify a hostname, would it be better to use the OS
hostname, or to ask the user to type one in?

[simonmorris, 2012/10/15 20:49:55]

Done.

+    std::cerr << "Usage: " << argv[0]

[Sergey Ulanov, 2012/10/15 18:25:30]

Here and below - style guide discourages usage of C++ streams for IO - use
[f]printf()/scanf() instead:
http://google-styleguide.googlecode.com/svn/trunk/cppguide.xml?showone=Stream...

[simonmorris, 2012/10/15 20:49:55]

Done.

+              << " -name=<hostname> -code=<auth-code> [-pin=<PIN>]\n";

[Sergey Ulanov, 2012/10/15 18:25:30]

I think it should be --name, --code and --pin

[simonmorris, 2012/10/15 20:49:55]

Done.

+    return 1;
+  }
+
+  if (host_pin.empty()) {
+    std::cout << "Enter a six-digit PIN: ";
+    SetEcho(false);
+    std::cin >> host_pin;
+    SetEcho(true);
+    std::cout << "\n";
+    std::string host_pin_confirm;
+    std::cout << "Enter the same PIN again: ";
+    SetEcho(false);
+    std::cin >> host_pin_confirm;
+    SetEcho(true);
+    std::cout << "\n";
+    if (host_pin != host_pin_confirm) {
+      std::cerr << "You entered different PINs.\n";

[Sergey Ulanov, 2012/10/15 18:25:30]

better UX would be to ask the PIN again instead of quitting here. 

[simonmorris, 2012/10/15 20:49:55]

Done.

+      return 1;
+    }
+  }
+
+  if (!remoting::IsPinValid(host_pin)) {
+    std::cerr << "Please use a PIN consisting of at least six digits.\n";
+    return 1;
+  }
+
+  // This object instance is required by Chrome code (for example,
+  // FilePath, LazyInstance, MessageLoop).
+  base::AtExitManager exit_manager;
+
+  // Provide message loops and threads for the URLRequestContextGetter.
+  message_loop = new MessageLoop(MessageLoop::TYPE_UI);

[Sergey Ulanov, 2012/10/15 18:25:30]

This object is never freed. I think it's more common to allocate MessageLoops on
the stack instead of on the heap:

MessageLoop message_loop;
g_message_loop = &message_loop;

... Run the loop ...

g_message_loop = NULL;

[simonmorris, 2012/10/15 20:49:55]

Done.

+  base::Thread io_thread("IO thread");
+  base::Thread::Options io_thread_options(MessageLoop::TYPE_IO, 0);
+  io_thread.StartWithOptions(io_thread_options);
+
+  // The scope ensures that the URLRequestContextGetter and HostStarter
+  // are destroyed before the IO thread is stopped.

[Sergey Ulanov, 2012/10/15 18:25:30]

nit: Alternatively you could just reset  url_request_context_getter and
host_starter explicitly. IMHO that would make this code more readable, 

[simonmorris, 2012/10/15 20:49:55]

Done.

+  {
+    scoped_refptr<net::URLRequestContextGetter> url_request_context_getter(
+        new remoting::URLRequestContextGetter(
+            message_loop->message_loop_proxy(),
+            io_thread.message_loop_proxy()));
+
+    // Start the host.
+    scoped_ptr<HostStarter> host_starter(
+        HostStarter::Create(url_request_context_getter));
+    host_starter->StartHost(host_name, host_pin, true, auth_code,
+                            base::Bind(&OnDone));
+
+    // Run the message loop until the StartHost completion callback.
+    base::RunLoop run_loop;
+    run_loop.Run();
+  }
+
+  io_thread.Stop();
+
+  return fail ? 1 : 0;
+}