// 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 "google_apis/gcm/engine/mcs_client.h"
#include "base/basictypes.h"
#include "base/message_loop/message_loop.h"
#include "base/strings/string_number_conversions.h"
#include "google_apis/gcm/base/mcs_util.h"
#include "google_apis/gcm/base/socket_stream.h"
#include "google_apis/gcm/engine/connection_factory.h"
#include "google_apis/gcm/engine/rmq_store.h"
using namespace google::protobuf::io;
namespace gcm {
namespace {
typedef scoped_ptr<google::protobuf::MessageLite> MCSProto;
// TODO(zea): get these values from MCS settings.
const int64 kHeartbeatDefaultSeconds = 60 * 15; // 15 minutes.
// The category of messages intended for the GCM client itself from MCS.
const char kMCSCategory[] = "com.google.android.gsf.gtalkservice";
// The from field for messages originating in the GCM client.
const char kGCMFromField[] = "gcm@android.com";
// MCS status message types.
const char kIdleNotification[] = "IdleNotification";
// TODO(zea): consume the following message types:
// const char kAlwaysShowOnIdle[] = "ShowAwayOnIdle";
// const char kPowerNotification[] = "PowerNotification";
// const char kDataActiveNotification[] = "DataActiveNotification";
// The number of unacked messages to allow before sending a stream ack.
// Applies to both incoming and outgoing messages.
// TODO(zea): make this server configurable.
const int kUnackedMessageBeforeStreamAck = 10;
// The global maximum number of pending messages to have in the send queue.
const size_t kMaxSendQueueSize = 10 * 1024;
// The maximum message size that can be sent to the server.
const int kMaxMessageBytes = 4 * 1024; // 4KB, like the server.
// Helper for converting a proto persistent id list to a vector of strings.
bool BuildPersistentIdListFromProto(const google::protobuf::string& bytes,
std::vector<std::string>* id_list) {
mcs_proto::SelectiveAck selective_ack;
if (!selective_ack.ParseFromString(bytes))
return false;
std::vector<std::string> new_list;
for (int i = 0; i < selective_ack.id_size(); ++i) {
DCHECK(!selective_ack.id(i).empty());
new_list.push_back(selective_ack.id(i));
}
id_list->swap(new_list);
return true;
}
} // namespace
struct ReliablePacketInfo {
ReliablePacketInfo();
~ReliablePacketInfo();
// The stream id with which the message was sent.
uint32 stream_id;
// If reliable delivery was requested, the persistent id of the message.
std::string persistent_id;
// The type of message itself (for easier lookup).
uint8 tag;
// The protobuf of the message itself.
MCSProto protobuf;
};
ReliablePacketInfo::ReliablePacketInfo()
: stream_id(0), tag(0) {
}
ReliablePacketInfo::~ReliablePacketInfo() {}
MCSClient::MCSClient(
const base::FilePath& rmq_path,
ConnectionFactory* connection_factory,
scoped_refptr<base::SequencedTaskRunner> blocking_task_runner)
: state_(UNINITIALIZED),
android_id_(0),
security_token_(0),
connection_factory_(connection_factory),
connection_handler_(NULL),
last_device_to_server_stream_id_received_(0),
last_server_to_device_stream_id_received_(0),
stream_id_out_(0),
stream_id_in_(0),
rmq_store_(rmq_path, blocking_task_runner),
heartbeat_interval_(
base::TimeDelta::FromSeconds(kHeartbeatDefaultSeconds)),
heartbeat_timer_(true, true),
blocking_task_runner_(blocking_task_runner),
weak_ptr_factory_(this) {
}
MCSClient::~MCSClient() {
}
void MCSClient::Initialize(
const InitializationCompleteCallback& initialization_callback,
const OnMessageReceivedCallback& message_received_callback,
const OnMessageSentCallback& message_sent_callback) {
DCHECK_EQ(state_, UNINITIALIZED);
initialization_callback_ = initialization_callback;
message_received_callback_ = message_received_callback;
message_sent_callback_ = message_sent_callback;
state_ = LOADING;
rmq_store_.Load(base::Bind(&MCSClient::OnRMQLoadFinished,
weak_ptr_factory_.GetWeakPtr()));
connection_factory_->Initialize(
base::Bind(&MCSClient::ResetStateAndBuildLoginRequest,
weak_ptr_factory_.GetWeakPtr()),
base::Bind(&MCSClient::HandlePacketFromWire,
weak_ptr_factory_.GetWeakPtr()),
base::Bind(&MCSClient::MaybeSendMessage,
weak_ptr_factory_.GetWeakPtr()));
connection_handler_ = connection_factory_->GetConnectionHandler();
}
void MCSClient::Login(uint64 android_id, uint64 security_token) {
DCHECK_EQ(state_, LOADED);
if (android_id != android_id_ && security_token != security_token_) {
DCHECK(android_id);
DCHECK(security_token);
DCHECK(restored_unackeds_server_ids_.empty());
android_id_ = android_id;
security_token_ = security_token;
rmq_store_.SetDeviceCredentials(android_id_,
security_token_,
base::Bind(&MCSClient::OnRMQUpdateFinished,
weak_ptr_factory_.GetWeakPtr()));
}
state_ = CONNECTING;
connection_factory_->Connect();
}
void MCSClient::SendMessage(const MCSMessage& message, bool use_rmq) {
DCHECK_EQ(state_, CONNECTED);
if (to_send_.size() > kMaxSendQueueSize) {
base::MessageLoop::current()->PostTask(
FROM_HERE,
base::Bind(message_sent_callback_, "Message queue full."));
return;
}
if (message.size() > kMaxMessageBytes) {
base::MessageLoop::current()->PostTask(
FROM_HERE,
base::Bind(message_sent_callback_, "Message too large."));
return;
}
ReliablePacketInfo* packet_info = new ReliablePacketInfo();
packet_info->protobuf = message.CloneProtobuf();
if (use_rmq) {
PersistentId persistent_id = GetNextPersistentId();
DVLOG(1) << "Setting persistent id to " << persistent_id;
packet_info->persistent_id = persistent_id;
SetPersistentId(persistent_id,
packet_info->protobuf.get());
rmq_store_.AddOutgoingMessage(persistent_id,
MCSMessage(message.tag(),
*(packet_info->protobuf)),
base::Bind(&MCSClient::OnRMQUpdateFinished,
weak_ptr_factory_.GetWeakPtr()));
} else {
// Check that there is an active connection to the endpoint.
if (!connection_handler_->CanSendMessage()) {
base::MessageLoop::current()->PostTask(
FROM_HERE,
base::Bind(message_sent_callback_, "Unable to reach endpoint"));
return;
}
}
to_send_.push_back(make_linked_ptr(packet_info));
MaybeSendMessage();
}
void MCSClient::Destroy() {
rmq_store_.Destroy(base::Bind(&MCSClient::OnRMQUpdateFinished,
weak_ptr_factory_.GetWeakPtr()));
}
void MCSClient::ResetStateAndBuildLoginRequest(
mcs_proto::LoginRequest* request) {
DCHECK(android_id_);
DCHECK(security_token_);
stream_id_in_ = 0;
stream_id_out_ = 1;
last_device_to_server_stream_id_received_ = 0;
last_server_to_device_stream_id_received_ = 0;
// TODO(zea): expire all messages older than their TTL.
// Add any pending acknowledgments to the list of ids.
for (StreamIdToPersistentIdMap::const_iterator iter =
unacked_server_ids_.begin();
iter != unacked_server_ids_.end(); ++iter) {
restored_unackeds_server_ids_.push_back(iter->second);
}
unacked_server_ids_.clear();
// Any acknowledged server ids which have not been confirmed by the server
// are treated like unacknowledged ids.
for (std::map<StreamId, PersistentIdList>::const_iterator iter =
acked_server_ids_.begin();
iter != acked_server_ids_.end(); ++iter) {
restored_unackeds_server_ids_.insert(restored_unackeds_server_ids_.end(),
iter->second.begin(),
iter->second.end());
}
acked_server_ids_.clear();
// Then build the request, consuming all pending acknowledgments.
request->Swap(BuildLoginRequest(android_id_, security_token_).get());
for (PersistentIdList::const_iterator iter =
restored_unackeds_server_ids_.begin();
iter != restored_unackeds_server_ids_.end(); ++iter) {
request->add_received_persistent_id(*iter);
}
acked_server_ids_[stream_id_out_] = restored_unackeds_server_ids_;
restored_unackeds_server_ids_.clear();
// Push all unacknowledged messages to front of send queue. No need to save
// to RMQ, as all messages that reach this point should already have been
// saved as necessary.
while (!to_resend_.empty()) {
to_send_.push_front(to_resend_.back());
to_resend_.pop_back();
}
DVLOG(1) << "Resetting state, with " << request->received_persistent_id_size()
<< " incoming acks pending, and " << to_send_.size()
<< " pending outgoing messages.";
heartbeat_timer_.Stop();
state_ = CONNECTING;
}
void MCSClient::SendHeartbeat() {
SendMessage(MCSMessage(kHeartbeatPingTag, mcs_proto::HeartbeatPing()),
false);
}
void MCSClient::OnRMQLoadFinished(const RMQStore::LoadResult& result) {
if (!result.success) {
state_ = UNINITIALIZED;
LOG(ERROR) << "Failed to load/create RMQ state. Not connecting.";
initialization_callback_.Run(false, 0, 0);
return;
}
state_ = LOADED;
stream_id_out_ = 1; // Login request is hardcoded to id 1.
if (result.device_android_id == 0 || result.device_security_token == 0) {
DVLOG(1) << "No device credentials found, assuming new client.";
initialization_callback_.Run(true, 0, 0);
return;
}
android_id_ = result.device_android_id;
security_token_ = result.device_security_token;
DVLOG(1) << "RMQ Load finished with " << result.incoming_messages.size()
<< " incoming acks pending and " << result.outgoing_messages.size()
<< " outgoing messages pending.";
restored_unackeds_server_ids_ = result.incoming_messages;
// First go through and order the outgoing messages by recency.
std::map<uint64, google::protobuf::MessageLite*> ordered_messages;
for (std::map<PersistentId, google::protobuf::MessageLite*>::const_iterator
iter = result.outgoing_messages.begin();
iter != result.outgoing_messages.end(); ++iter) {
uint64 timestamp = 0;
if (!base::StringToUint64(iter->first, ×tamp)) {
LOG(ERROR) << "Invalid restored message.";
return;
}
ordered_messages[timestamp] = iter->second;
}
// Now go through and add the outgoing messages to the send queue in their
// appropriate order (oldest at front, most recent at back).
for (std::map<uint64, google::protobuf::MessageLite*>::const_iterator
iter = ordered_messages.begin();
iter != ordered_messages.end(); ++iter) {
ReliablePacketInfo* packet_info = new ReliablePacketInfo();
packet_info->protobuf.reset(iter->second);
packet_info->persistent_id = base::Uint64ToString(iter->first);
to_send_.push_back(make_linked_ptr(packet_info));
}
initialization_callback_.Run(true, android_id_, security_token_);
}
void MCSClient::OnRMQUpdateFinished(bool success) {
LOG_IF(ERROR, !success) << "RMQ Update failed!";
// TODO(zea): Rebuild the store from scratch in case of persistence failure?
}
void MCSClient::MaybeSendMessage() {
if (to_send_.empty())
return;
if (!connection_handler_->CanSendMessage())
return;
// TODO(zea): drop messages older than their TTL.
DVLOG(1) << "Pending output message found, sending.";
MCSPacketInternal packet = to_send_.front();
to_send_.pop_front();
if (!packet->persistent_id.empty())
to_resend_.push_back(packet);
SendPacketToWire(packet.get());
}
void MCSClient::SendPacketToWire(ReliablePacketInfo* packet_info) {
// Reset the heartbeat interval.
heartbeat_timer_.Reset();
packet_info->stream_id = ++stream_id_out_;
DVLOG(1) << "Sending packet of type " << packet_info->protobuf->GetTypeName();
// Set the proper last received stream id to acknowledge received server
// packets.
DVLOG(1) << "Setting last stream id received to "
<< stream_id_in_;
SetLastStreamIdReceived(stream_id_in_,
packet_info->protobuf.get());
if (stream_id_in_ != last_server_to_device_stream_id_received_) {
last_server_to_device_stream_id_received_ = stream_id_in_;
// Mark all acknowledged server messages as such. Note: they're not dropped,
// as it may be that they'll need to be re-acked if this message doesn't
// make it.
PersistentIdList persistent_id_list;
for (StreamIdToPersistentIdMap::const_iterator iter =
unacked_server_ids_.begin();
iter != unacked_server_ids_.end(); ++iter) {
DCHECK_LE(iter->first, last_server_to_device_stream_id_received_);
persistent_id_list.push_back(iter->second);
}
unacked_server_ids_.clear();
acked_server_ids_[stream_id_out_] = persistent_id_list;
}
connection_handler_->SendMessage(*packet_info->protobuf);
}
void MCSClient::HandleMCSDataMesssage(
scoped_ptr<google::protobuf::MessageLite> protobuf) {
mcs_proto::DataMessageStanza* data_message =
reinterpret_cast<mcs_proto::DataMessageStanza*>(protobuf.get());
// TODO(zea): implement a proper status manager rather than hardcoding these
// values.
scoped_ptr<mcs_proto::DataMessageStanza> response(
new mcs_proto::DataMessageStanza());
response->set_from(kGCMFromField);
bool send = false;
for (int i = 0; i < data_message->app_data_size(); ++i) {
const mcs_proto::AppData& app_data = data_message->app_data(i);
if (app_data.key() == kIdleNotification) {
// Tell the MCS server the client is not idle.
send = true;
mcs_proto::AppData data;
data.set_key(kIdleNotification);
data.set_value("false");
response->add_app_data()->CopyFrom(data);
response->set_category(kMCSCategory);
}
}
if (send) {
SendMessage(
MCSMessage(kDataMessageStanzaTag,
response.PassAs<const google::protobuf::MessageLite>()),
false);
}
}
void MCSClient::HandlePacketFromWire(
scoped_ptr<google::protobuf::MessageLite> protobuf) {
if (!protobuf.get())
return;
uint8 tag = GetMCSProtoTag(*protobuf);
PersistentId persistent_id = GetPersistentId(*protobuf);
StreamId last_stream_id_received = GetLastStreamIdReceived(*protobuf);
if (last_stream_id_received != 0) {
last_device_to_server_stream_id_received_ = last_stream_id_received;
// Process device to server messages that have now been acknowledged by the
// server. Because messages are stored in order, just pop off all that have
// a stream id lower than server's last received stream id.
HandleStreamAck(last_stream_id_received);
// Process server_to_device_messages that the server now knows were
// acknowledged. Again, they're in order, so just keep going until the
// stream id is reached.
StreamIdList acked_stream_ids_to_remove;
for (std::map<StreamId, PersistentIdList>::iterator iter =
acked_server_ids_.begin();
iter != acked_server_ids_.end() &&
iter->first <= last_stream_id_received; ++iter) {
acked_stream_ids_to_remove.push_back(iter->first);
}
for (StreamIdList::iterator iter = acked_stream_ids_to_remove.begin();
iter != acked_stream_ids_to_remove.end(); ++iter) {
acked_server_ids_.erase(*iter);
}
}
++stream_id_in_;
if (!persistent_id.empty()) {
unacked_server_ids_[stream_id_in_] = persistent_id;
rmq_store_.AddIncomingMessage(persistent_id,
base::Bind(&MCSClient::OnRMQUpdateFinished,
weak_ptr_factory_.GetWeakPtr()));
}
DVLOG(1) << "Received message of type " << protobuf->GetTypeName()
<< " with persistent id "
<< (persistent_id.empty() ? "NULL" : persistent_id)
<< ", stream id " << stream_id_in_ << " and last stream id received "
<< last_stream_id_received;
if (unacked_server_ids_.size() > 0 &&
unacked_server_ids_.size() % kUnackedMessageBeforeStreamAck == 0) {
SendMessage(MCSMessage(kIqStanzaTag,
BuildStreamAck().
PassAs<const google::protobuf::MessageLite>()),
false);
}
switch (tag) {
case kLoginResponseTag: {
mcs_proto::LoginResponse* login_response =
reinterpret_cast<mcs_proto::LoginResponse*>(protobuf.get());
DVLOG(1) << "Received login response:";
DVLOG(1) << " Id: " << login_response->id();
DVLOG(1) << " Timestamp: " << login_response->server_timestamp();
if (login_response->has_error()) {
state_ = UNINITIALIZED;
DVLOG(1) << " Error code: " << login_response->error().code();
DVLOG(1) << " Error message: " << login_response->error().message();
initialization_callback_.Run(false, 0, 0);
return;
}
state_ = CONNECTED;
stream_id_in_ = 1; // To account for the login response.
DCHECK_EQ(1U, stream_id_out_);
// Pass the login response on up.
base::MessageLoop::current()->PostTask(
FROM_HERE,
base::Bind(message_received_callback_,
MCSMessage(tag,
protobuf.PassAs<
const google::protobuf::MessageLite>())));
// If there are pending messages, attempt to send one.
if (!to_send_.empty()) {
base::MessageLoop::current()->PostTask(
FROM_HERE,
base::Bind(&MCSClient::MaybeSendMessage,
weak_ptr_factory_.GetWeakPtr()));
}
heartbeat_timer_.Start(FROM_HERE,
heartbeat_interval_,
base::Bind(&MCSClient::SendHeartbeat,
weak_ptr_factory_.GetWeakPtr()));
return;
}
case kHeartbeatPingTag:
DCHECK_GE(stream_id_in_, 1U);
DVLOG(1) << "Received heartbeat ping, sending ack.";
SendMessage(
MCSMessage(kHeartbeatAckTag, mcs_proto::HeartbeatAck()), false);
return;
case kHeartbeatAckTag:
DCHECK_GE(stream_id_in_, 1U);
DVLOG(1) << "Received heartbeat ack.";
// TODO(zea): add logic to reconnect if no ack received within a certain
// timeout (with backoff).
return;
case kCloseTag:
LOG(ERROR) << "Received close command, closing connection.";
state_ = UNINITIALIZED;
initialization_callback_.Run(false, 0, 0);
// TODO(zea): should this happen in non-error cases? Reconnect?
return;
case kIqStanzaTag: {
DCHECK_GE(stream_id_in_, 1U);
mcs_proto::IqStanza* iq_stanza =
reinterpret_cast<mcs_proto::IqStanza*>(protobuf.get());
const mcs_proto::Extension& iq_extension = iq_stanza->extension();
switch (iq_extension.id()) {
case kSelectiveAck: {
PersistentIdList acked_ids;
if (BuildPersistentIdListFromProto(iq_extension.data(),
&acked_ids)) {
HandleSelectiveAck(acked_ids);
}
return;
}
case kStreamAck:
// Do nothing. The last received stream id is always processed if it's
// present.
return;
default:
LOG(WARNING) << "Received invalid iq stanza extension "
<< iq_extension.id();
return;
}
}
case kDataMessageStanzaTag: {
DCHECK_GE(stream_id_in_, 1U);
mcs_proto::DataMessageStanza* data_message =
reinterpret_cast<mcs_proto::DataMessageStanza*>(protobuf.get());
if (data_message->category() == kMCSCategory) {
HandleMCSDataMesssage(protobuf.Pass());
return;
}
DCHECK(protobuf.get());
base::MessageLoop::current()->PostTask(
FROM_HERE,
base::Bind(message_received_callback_,
MCSMessage(tag,
protobuf.PassAs<
const google::protobuf::MessageLite>())));
return;
}
default:
LOG(ERROR) << "Received unexpected message of type "
<< static_cast<int>(tag);
return;
}
}
void MCSClient::HandleStreamAck(StreamId last_stream_id_received) {
PersistentIdList acked_outgoing_persistent_ids;
StreamIdList acked_outgoing_stream_ids;
while (!to_resend_.empty() &&
to_resend_.front()->stream_id <= last_stream_id_received) {
const MCSPacketInternal& outgoing_packet = to_resend_.front();
acked_outgoing_persistent_ids.push_back(outgoing_packet->persistent_id);
acked_outgoing_stream_ids.push_back(outgoing_packet->stream_id);
to_resend_.pop_front();
}
DVLOG(1) << "Server acked " << acked_outgoing_persistent_ids.size()
<< " outgoing messages, " << to_resend_.size()
<< " remaining unacked";
rmq_store_.RemoveOutgoingMessages(acked_outgoing_persistent_ids,
base::Bind(&MCSClient::OnRMQUpdateFinished,
weak_ptr_factory_.GetWeakPtr()));
HandleServerConfirmedReceipt(last_stream_id_received);
}
void MCSClient::HandleSelectiveAck(const PersistentIdList& id_list) {
// First check the to_resend_ queue. Acknowledgments should always happen
// in the order they were sent, so if messages are present they should match
// the acknowledge list.
PersistentIdList::const_iterator iter = id_list.begin();
for (; iter != id_list.end() && !to_resend_.empty(); ++iter) {
const MCSPacketInternal& outgoing_packet = to_resend_.front();
DCHECK_EQ(outgoing_packet->persistent_id, *iter);
// No need to re-acknowledge any server messages this message already
// acknowledged.
StreamId device_stream_id = outgoing_packet->stream_id;
HandleServerConfirmedReceipt(device_stream_id);
to_resend_.pop_front();
}
// If the acknowledged ids aren't all there, they might be in the to_send_
// queue (typically when a StreamAck confirms messages as part of a login
// response).
for (; iter != id_list.end() && !to_send_.empty(); ++iter) {
const MCSPacketInternal& outgoing_packet = to_send_.front();
DCHECK_EQ(outgoing_packet->persistent_id, *iter);
// No need to re-acknowledge any server messages this message already
// acknowledged.
StreamId device_stream_id = outgoing_packet->stream_id;
HandleServerConfirmedReceipt(device_stream_id);
to_send_.pop_front();
}
DCHECK(iter == id_list.end());
DVLOG(1) << "Server acked " << id_list.size()
<< " messages, " << to_resend_.size() << " remaining unacked.";
rmq_store_.RemoveOutgoingMessages(id_list,
base::Bind(&MCSClient::OnRMQUpdateFinished,
weak_ptr_factory_.GetWeakPtr()));
// Resend any remaining outgoing messages, as they were not received by the
// server.
DVLOG(1) << "Resending " << to_resend_.size() << " messages.";
while (!to_resend_.empty()) {
to_send_.push_front(to_resend_.back());
to_resend_.pop_back();
}
}
void MCSClient::HandleServerConfirmedReceipt(StreamId device_stream_id) {
// TODO(zea): use a message id the sender understands.
base::MessageLoop::current()->PostTask(
FROM_HERE,
base::Bind(message_sent_callback_,
"Message " + base::UintToString(device_stream_id) + " sent."));
PersistentIdList acked_incoming_ids;
for (std::map<StreamId, PersistentIdList>::iterator iter =
acked_server_ids_.begin();
iter != acked_server_ids_.end() &&
iter->first <= device_stream_id;) {
acked_incoming_ids.insert(acked_incoming_ids.end(),
iter->second.begin(),
iter->second.end());
acked_server_ids_.erase(iter++);
}
DVLOG(1) << "Server confirmed receipt of " << acked_incoming_ids.size()
<< " acknowledged server messages.";
rmq_store_.RemoveIncomingMessages(acked_incoming_ids,
base::Bind(&MCSClient::OnRMQUpdateFinished,
weak_ptr_factory_.GetWeakPtr()));
}
MCSClient::PersistentId MCSClient::GetNextPersistentId() {
return base::Uint64ToString(base::TimeTicks::Now().ToInternalValue());
}
} // namespace gcm