src/components/copresence/handlers/gcm_handler.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "components/copresence/handlers/gcm_handler.h"
   6
   7 #include "base/base64.h"
   8 #include "base/bind.h"
   9 #include "base/logging.h"
  10 #include "base/strings/string_util.h"
  11 #include "components/copresence/handlers/directive_handler.h"
  12 #include "components/copresence/proto/push_message.pb.h"
  13 #include "components/gcm_driver/gcm_driver.h"
  14
  15 using gcm::GCMClient;
  16
  17 namespace {
  18
  19 // TODO(ckehoe): Move this to a common library.
  20 bool Base64Decode(std::string data, std::string* out) {
  21   // Convert from URL-safe.
  22   base::ReplaceChars(data, "-", "+", &data);
  23   base::ReplaceChars(data, "_", "/", &data);
  24
  25   // Add padding if needed.
  26   while (data.size() % 4)
  27     data.push_back('=');
  28
  29   // Decode.
  30   return base::Base64Decode(data, out);
  31 }
  32
  33 }  // namespace
  34
  35 namespace copresence {
  36
  37 const char GCMHandler::kCopresenceAppId[] =
  38     "com.google.android.gms.location.copresence";
  39 const char GCMHandler::kCopresenceSenderId[] = "745476177629";
  40 const char GCMHandler::kGcmMessageKey[] = "PUSH_MESSAGE";
  41
  42
  43 // Public functions.
  44
  45 GCMHandler::GCMHandler(gcm::GCMDriver* gcm_driver,
  46                        DirectiveHandler* directive_handler)
  47     : driver_(gcm_driver),
  48       directive_handler_(directive_handler),
  49       registration_callback_(base::Bind(&GCMHandler::RegistrationComplete,
  50                                         AsWeakPtr())) {
  51   DCHECK(driver_);
  52   DCHECK(directive_handler_);
  53
  54   driver_->AddAppHandler(kCopresenceAppId, this);
  55   driver_->Register(kCopresenceAppId,
  56                     std::vector<std::string>(1, kCopresenceSenderId),
  57                     registration_callback_);
  58 }
  59
  60 GCMHandler::~GCMHandler() {
  61   if (driver_)
  62     driver_->RemoveAppHandler(kCopresenceAppId);
  63 }
  64
  65 void GCMHandler::GetGcmId(const RegistrationCallback& callback) {
  66   if (gcm_id_.empty()) {
  67     pending_id_requests_.push_back(callback);
  68   } else {
  69     callback.Run(gcm_id_);
  70   }
  71 }
  72
  73 void GCMHandler::ShutdownHandler() {
  74   // The GCMDriver is going away. Make sure we don't try to contact it.
  75   driver_ = nullptr;
  76 }
  77
  78 void GCMHandler::OnMessage(const std::string& app_id,
  79                            const GCMClient::IncomingMessage& message) {
  80   DCHECK_EQ(kCopresenceAppId, app_id);
  81   DVLOG(2) << "Incoming GCM message";
  82
  83   const auto& content = message.data.find(kGcmMessageKey);
  84   if (content == message.data.end()) {
  85     LOG(ERROR) << "GCM message missing data key";
  86     return;
  87   }
  88
  89   std::string serialized_message;
  90   if (!Base64Decode(content->second, &serialized_message)) {
  91     LOG(ERROR) << "Couldn't decode GCM message";
  92     return;
  93   }
  94
  95   PushMessage push_message;
  96   if (!push_message.ParseFromString(serialized_message)) {
  97     LOG(ERROR) << "GCM message contained invalid proto";
  98     return;
  99   }
 100
 101   if (push_message.type() != PushMessage::REPORT) {
 102     DVLOG(2) << "Discarding non-report GCM message";
 103     return;
 104   }
 105
 106   DVLOG(3) << "Processing " << push_message.report().directive_size()
 107            << " directive(s) from GCM message";
 108   for (const Directive& directive : push_message.report().directive())
 109     directive_handler_->AddDirective(directive);
 110
 111   int message_count = push_message.report().subscribed_message_size();
 112   LOG_IF(WARNING, message_count > 0)
 113       << "Discarding " << message_count << " copresence messages sent via GCM";
 114 }
 115
 116 void GCMHandler::OnMessagesDeleted(const std::string& app_id) {
 117   DCHECK_EQ(kCopresenceAppId, app_id);
 118   DVLOG(2) << "GCM message overflow reported";
 119 }
 120
 121 void GCMHandler::OnSendError(
 122     const std::string& /* app_id */,
 123     const GCMClient::SendErrorDetails& /* send_error_details */) {
 124   NOTREACHED() << "Copresence clients should not be sending GCM messages";
 125 }
 126
 127 void GCMHandler::OnSendAcknowledged(const std::string& /* app_id */,
 128                                     const std::string& /* message_id */) {
 129   NOTREACHED() << "Copresence clients should not be sending GCM messages";
 130 }
 131
 132 bool GCMHandler::CanHandle(const std::string& app_id) const {
 133   return app_id == kCopresenceAppId;
 134 }
 135
 136
 137 // Private functions.
 138
 139 void GCMHandler::RegistrationComplete(const std::string& registration_id,
 140                                       GCMClient::Result result) {
 141   if (result == GCMClient::SUCCESS) {
 142     DVLOG(2) << "GCM registration successful. ID: " << registration_id;
 143     gcm_id_ = registration_id;
 144   } else {
 145     LOG(ERROR) << "GCM registration failed with error " << result;
 146   }
 147
 148   for (const RegistrationCallback& callback : pending_id_requests_) {
 149     callback.Run(result == GCMClient::SUCCESS ?
 150         registration_id : std::string());
 151   }
 152   pending_id_requests_.clear();
 153 }
 154
 155 }  // namespace copresence