GCP2.0 Device: mDNS basics

Socket binding and sending empty announcements

BUG=

Review URL: https://chromiumcodereview.appspot.com/16389002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@204754 0039d316-1c4b-4281-b951-d872f2087c98

5 files changed, 269 insertions, 0 deletions

diff --git a/cloud_print/cloud_print.gyp b/cloud_print/cloud_print.gyp
index b746f41..cf3c543 100644
--- a/cloud_print/cloud_print.gyp
+++ b/cloud_print/cloud_print.gyp
@@ -58,6 +58,7 @@
       'type': 'none',
       'dependencies': [
         'service/service.gyp:*',
+        'gcp20/prototype/gcp20_device.gyp:*',
       ],
       'conditions': [
         ['OS=="win"', {
diff --git a/cloud_print/gcp20/prototype/dns_sd_server.cc b/cloud_print/gcp20/prototype/dns_sd_server.cc
new file mode 100644
index 0000000..0ca8b43
--- /dev/null
+++ b/cloud_print/gcp20/prototype/dns_sd_server.cc
@@ -0,0 +1,137 @@
+// Copyright 2013 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 "cloud_print/gcp20/prototype/dns_sd_server.h"
+
+#include <string.h>
+
+#include "base/basictypes.h"
+#include "net/base/big_endian.h"
+#include "net/base/net_util.h"
+#include "net/dns/dns_protocol.h"
+
+namespace {
+
+const char* kDefaultIpAddressMulticast = "224.0.0.251";
+const uint16 kDefaultPortMulticast = 5353;
+
+// TODO(maksymb): Add possibility to set constants via command line arguments
+const uint32 kDefaultTTL = 60*60;  // in seconds
+
+}  // namespace
+
+DnsSdServer::DnsSdServer() : is_online_(false) {
+  // Do nothing
+}
+
+DnsSdServer::~DnsSdServer() {
+  Shutdown();
+}
+
+bool DnsSdServer::Start() {
+  if (is_online_)
+    return true;
+
+  if (!CreateSocket())
+    return false;
+
+  LOG(INFO) << "DNS server started";
+
+  SendAnnouncement(kDefaultTTL);
+
+  is_online_ = true;
+  return true;
+}
+
+void DnsSdServer::Update() {
+  if (!is_online_)
+    return;
+
+  SendAnnouncement(kDefaultTTL);
+}
+
+void DnsSdServer::Shutdown() {
+  if (!is_online_)
+    return;
+
+  SendAnnouncement(0);  // ttl is 0
+  socket_->Close();
+  is_online_ = false;
+  LOG(INFO) << "DNS server stopped";
+}
+
+void DnsSdServer::ProcessMessages() {
+  NOTIMPLEMENTED();  // implement this
+}
+
+bool DnsSdServer::CreateSocket() {
+  net::IPAddressNumber local_ip_any;
+  bool success = net::ParseIPLiteralToNumber("0.0.0.0", &local_ip_any);
+  DCHECK(success);
+
+  net::IPAddressNumber multicast_dns_ip_address;
+  success = net::ParseIPLiteralToNumber(kDefaultIpAddressMulticast,
+                                        &multicast_dns_ip_address);
+  DCHECK(success);
+
+
+  socket_.reset(new net::UDPSocket(net::DatagramSocket::DEFAULT_BIND,
+                                   net::RandIntCallback(),
+                                   NULL,
+                                   net::NetLog::Source()));
+
+  net::IPEndPoint local_address = net::IPEndPoint(local_ip_any,
+                                                  kDefaultPortMulticast);
+  multicast_address_ = net::IPEndPoint(multicast_dns_ip_address,
+                                       kDefaultPortMulticast);
+
+  socket_->AllowAddressReuse();
+
+  int status = socket_->Bind(local_address);
+  if (status < 0)
+    return false;
+
+  socket_->SetMulticastLoopbackMode(false);
+  status = socket_->JoinGroup(multicast_dns_ip_address);
+
+  if (status < 0)
+    return false;
+
+  DCHECK(socket_->is_connected());
+
+  return true;
+}
+
+bool DnsSdServer::CheckPendingQueries() {
+  NOTIMPLEMENTED();  // implement this
+  return false;
+}
+
+void DoNothing(int /*var*/) {
+  // Do nothing
+}
+
+void DnsSdServer::SendAnnouncement(uint32 ttl) {
+  // Create a message with allocated space for header.
+  // DNS header is temporary empty.
+  scoped_ptr<std::vector<uint8> > message(
+    new std::vector<uint8>(sizeof(net::dns_protocol::Header), 0));  // all is 0
+
+  // TODO(maksymb): Create and implement DnsResponse class
+
+  // Preparing for sending
+  scoped_refptr<net::IOBufferWithSize> buffer =
+    new net::IOBufferWithSize(static_cast<int>(message.get()->size()));
+  memcpy(buffer.get()->data(), message.get()->data(), message.get()->size());
+
+  // Create empty callback (we don't need it at all) and send packet
+  net::CompletionCallback callback = base::Bind(DoNothing);
+  socket_->SendTo(buffer.get(),
+                  buffer.get()->size(),
+                  multicast_address_,
+                  callback);
+
+  LOG(INFO) << "Announcement was sent with TTL: " << ttl;
+}
+
diff --git a/cloud_print/gcp20/prototype/dns_sd_server.h b/cloud_print/gcp20/prototype/dns_sd_server.h
new file mode 100644
index 0000000..9c8ed96
--- /dev/null
+++ b/cloud_print/gcp20/prototype/dns_sd_server.h
@@ -0,0 +1,62 @@
+// Copyright 2013 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.
+
+#ifndef GCP20_PROTOTYPE_DNS_SD_H_
+#define GCP20_PROTOTYPE_DNS_SD_H_
+
+#include <vector>
+
+#include "net/dns/dns_protocol.h"
+#include "net/udp/udp_socket.h"
+
+// Class for sending multicast announcements, receiving queries and answering on
+// them. Client should call |ProccessMessages| periodically to make server work.
+class DnsSdServer {
+ public:
+  // Constructs unstarted server.
+  DnsSdServer();
+
+  // Stops server.
+  ~DnsSdServer();
+
+  // Starts the server. Returns |true| if server works. Also sends
+  // announcement.
+  bool Start();
+
+  // Sends announcement if server works.
+  void Update();
+
+  // Stops server with announcement.
+  void Shutdown();
+
+  // Process pending queries for the server.
+  void ProcessMessages();
+
+  // Returns |true| if server works.
+  bool is_online() { return is_online_; }
+
+ private:
+  // Binds a socket to multicast address. Returns |true| on success.
+  bool CreateSocket();
+
+  // Sends announcement.
+  void SendAnnouncement(uint32 ttl);
+
+  // Returns |true| if server received some questions.
+  bool CheckPendingQueries();
+
+  // Stores |true| if server was started.
+  bool is_online_;
+
+  // Stores socket to multicast address.
+  scoped_ptr<net::UDPSocket> socket_;
+
+  // Stores multicast address end point.
+  net::IPEndPoint multicast_address_;
+
+  DISALLOW_COPY_AND_ASSIGN(DnsSdServer);
+};
+
+#endif  // GCP20_PROTOTYPE_DNS_SD_H_
+
diff --git a/cloud_print/gcp20/prototype/gcp20_device.cc b/cloud_print/gcp20/prototype/gcp20_device.cc
new file mode 100644
index 0000000..f210063
--- /dev/null
+++ b/cloud_print/gcp20/prototype/gcp20_device.cc
@@ -0,0 +1,28 @@
+// Copyright 2013 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 <stdio.h>
+
+#include "base/command_line.h"
+#include "base/logging.h"
+#include "base/threading/platform_thread.h"
+#include "cloud_print/gcp20/prototype/dns_sd_server.h"
+
+int main(int argc, char* argv[]) {
+  CommandLine::Init(argc, argv);
+
+  logging::InitLogging(NULL,
+                       logging::LOG_ONLY_TO_SYSTEM_DEBUG_LOG,
+                       logging::LOCK_LOG_FILE,
+                       logging::APPEND_TO_OLD_LOG_FILE,
+                       logging::DISABLE_DCHECK_FOR_NON_OFFICIAL_RELEASE_BUILDS);
+
+  DnsSdServer dns_sd_server;
+  dns_sd_server.Start();
+  base::PlatformThread::Sleep(base::TimeDelta::FromSeconds(2));
+  dns_sd_server.Shutdown();
+
+  return 0;
+}
+
diff --git a/cloud_print/gcp20/prototype/gcp20_device.gyp b/cloud_print/gcp20/prototype/gcp20_device.gyp
new file mode 100644
index 0000000..7946960
--- /dev/null
+++ b/cloud_print/gcp20/prototype/gcp20_device.gyp
@@ -0,0 +1,41 @@
+# Copyright 2013 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.
+
+{
+  'target_defaults': {
+    'variables': {
+      'chromium_code': 1,
+      'enable_wexit_time_destructors': 1,
+    },
+    'include_dirs': [
+      '<(DEPTH)',
+      # To allow including "version.h"
+      '<(SHARED_INTERMEDIATE_DIR)',
+    ],
+  },
+  'targets': [
+    {
+      'target_name': 'gcp20_device',
+      'type': 'executable',
+      'dependencies': [
+        '<(DEPTH)/base/base.gyp:base',
+        '<(DEPTH)/net/net.gyp:net',
+      ],
+      'sources': [
+        'dns_sd_server.cc',
+        'gcp20_device.cc',
+      ],
+      'msvs_settings': {
+        'VCLinkerTool': {
+          'SubSystem': '1',         # Set /SUBSYSTEM:CONSOLE
+          'AdditionalDependencies': [
+              'secur32.lib',
+              'httpapi.lib',
+              'Ws2_32.lib',
+          ],
+        },
+      },
+    },
+  ],
+}