[HICN-690] Transport Library Major Refactory

The current patch provides a major refactory of the transportlibrary.
A summary of the different components that underwent major modifications is
reported below.

- Transport protocol updates
The hierarchy of classes has been optimized to have common transport services
across different transport protocols. This can allow to customize a transport
protocol with new features.

- A new real-time communication protocol
The RTC protocol has been optimized in terms of algorithms to reduce
consumer-producer synchronization latency.

- A novel socket API
The API has been reworked to be easier to consumer but also to have a more
efficient integration in L4 proxies.

- Several performance improvements
A large number of performance improvements have been included in
particular to make the entire stack zero-copy and optimize cache miss.

- New memory buffer framework
Memory management has been reworked entirely to provide a more efficient infra
with a richer API. Buffers are now allocated in blocks and a single buffer
holds the memory for (1) the shared_ptr control block, (2) the metadata of the
packet (e.g. name, pointer to other buffers if buffer is chained and relevant
offsets), and (3) the packet itself, as it is sent/received over the network.

- A new slab allocator
Dynamic memory allocation is now managed by a novel slab allocator that is
optimised for packet processing and connection management. Memory is organized
in pools of blocks all of the same size which are used during the processing of
outgoing/incoming packets. When a memory block Is allocated is always taken
from a global pool and when it is deallocated is returned to the pool, thus
avoiding the cost of any heap allocation in the data path.

- New transport connectors
Consumer and producer end-points can communication either using an hicn packet
forwarder or with direct connector based on shared memories or sockets.
The usage of transport connectors typically for unit and funcitonal
testing but may have additional usage.

- Support for FEC/ECC for transport services
FEC/ECC via reed solomon is supported by default and made available to
transport services as a modular component. Reed solomon block codes is a
default FEC model that can be replaced in a modular way by many other
codes including RLNC not avaiable in this distribution.
The current FEC framework support variable size padding and efficiently
makes use of the infra memory buffers to avoid additiona copies.

- Secure transport framework for signature computation and verification
Crypto support is nativelty used in hICN for integrity and authenticity.
Novel support that includes RTC has been implemented and made modular
and reusable acrosso different transport protocols.

- TLS - Transport layer security over hicn
Point to point confidentiality is provided by integrating TLS on top of
hICN reliable and non-reliable transport. The integration is common and
makes a different use of the TLS record.

- MLS - Messaging layer security over hicn
MLS integration on top of hICN is made by using the MLSPP implemetation
open sourced by Cisco. We have included instrumentation tools to deploy
performance and functional tests of groups of end-points.

- Android support
The overall code has been heavily tested in Android environments and
has received heavy lifting to better run natively in recent Android OS.

Co-authored-by: Mauro Sardara <msardara@cisco.com>
Co-authored-by: Michele Papalini <micpapal@cisco.com>
Co-authored-by: Olivier Roques <oroques+fdio@cisco.com>
Co-authored-by: Giulio Grassi <gigrassi@cisco.com>
Change-Id: If477ba2fa686e6f47bdf96307ac60938766aef69
Signed-off-by: Luca Muscariello <muscariello@ieee.org>

1 files changed, 607 insertions, 0 deletions

diff --git a/libtransport/src/protocols/rtc/rtc.cc b/libtransport/src/protocols/rtc/rtc.cc
new file mode 100644
index 000000000..bb95ab686
--- /dev/null
+++ b/libtransport/src/protocols/rtc/rtc.cc
@@ -0,0 +1,607 @@
+/*
+ * Copyright (c) 2017-2019 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <hicn/transport/core/global_object_pool.h>
+#include <hicn/transport/interfaces/socket_consumer.h>
+#include <implementation/socket_consumer.h>
+#include <math.h>
+#include <protocols/rtc/rtc.h>
+#include <protocols/rtc/rtc_consts.h>
+#include <protocols/rtc/rtc_rc_queue.h>
+
+#include <algorithm>
+
+namespace transport {
+
+namespace protocol {
+
+namespace rtc {
+
+using namespace interface;
+
+RTCTransportProtocol::RTCTransportProtocol(
+    implementation::ConsumerSocket *icn_socket)
+    : TransportProtocol(icn_socket, nullptr),
+      DatagramReassembly(icn_socket, this),
+      number_(0) {
+  icn_socket->getSocketOption(PORTAL, portal_);
+  round_timer_ = std::make_unique<asio::steady_timer>(portal_->getIoService());
+  scheduler_timer_ =
+      std::make_unique<asio::steady_timer>(portal_->getIoService());
+}
+
+RTCTransportProtocol::~RTCTransportProtocol() {}
+
+void RTCTransportProtocol::resume() {
+  if (is_running_) return;
+
+  is_running_ = true;
+
+  newRound();
+
+  portal_->runEventsLoop();
+  is_running_ = false;
+}
+
+// private
+void RTCTransportProtocol::initParams() {
+  portal_->setConsumerCallback(this);
+
+  rc_ = std::make_shared<RTCRateControlQueue>();
+  ldr_ = std::make_shared<RTCLossDetectionAndRecovery>(
+      std::bind(&RTCTransportProtocol::sendRtxInterest, this,
+                std::placeholders::_1),
+      portal_->getIoService());
+
+  state_ = std::make_shared<RTCState>(
+      std::bind(&RTCTransportProtocol::sendProbeInterest, this,
+                std::placeholders::_1),
+      std::bind(&RTCTransportProtocol::discoveredRtt, this),
+      portal_->getIoService());
+
+  rc_->setState(state_);
+  // TODO: for the moment we keep the congestion control disabled
+  // rc_->tunrOnRateControl();
+  ldr_->setState(state_);
+
+  // protocol state
+  start_send_interest_ = false;
+  current_state_ = SyncState::catch_up;
+
+  // Cancel timer
+  number_++;
+  round_timer_->cancel();
+  scheduler_timer_->cancel();
+  scheduler_timer_on_ = false;
+
+  // delete all timeouts and future nacks
+  timeouts_or_nacks_.clear();
+
+  // cwin vars
+  current_sync_win_ = INITIAL_WIN;
+  max_sync_win_ = INITIAL_WIN_MAX;
+
+  // names/packets var
+  next_segment_ = 0;
+
+  socket_->setSocketOption(GeneralTransportOptions::INTEREST_LIFETIME,
+                           RTC_INTEREST_LIFETIME);
+}
+
+// private
+void RTCTransportProtocol::reset() {
+  TRANSPORT_LOGD("reset called");
+  initParams();
+  newRound();
+}
+
+void RTCTransportProtocol::inactiveProducer() {
+  // when the producer is inactive we reset the consumer state
+  // cwin vars
+  current_sync_win_ = INITIAL_WIN;
+  max_sync_win_ = INITIAL_WIN_MAX;
+
+  TRANSPORT_LOGD("Current window: %u, max_sync_win_: %u", current_sync_win_,
+                 max_sync_win_);
+
+  // names/packets var
+  next_segment_ = 0;
+
+  ldr_->clear();
+}
+
+void RTCTransportProtocol::newRound() {
+  round_timer_->expires_from_now(std::chrono::milliseconds(ROUND_LEN));
+  // TODO pass weak_ptr here
+  round_timer_->async_wait([this, n{number_}](std::error_code ec) {
+    if (ec) return;
+
+    if (n != number_) {
+      return;
+    }
+
+    // saving counters that will be reset on new round
+    uint32_t sent_retx = state_->getSentRtxInRound();
+    uint32_t received_bytes = state_->getReceivedBytesInRound();
+    uint32_t sent_interest = state_->getSentInterestInRound();
+    uint32_t lost_data = state_->getLostData();
+    uint32_t recovered_losses = state_->getRecoveredLosses();
+    uint32_t received_nacks = state_->getReceivedNacksInRound();
+
+    bool in_sync = (current_state_ == SyncState::in_sync);
+    state_->onNewRound((double)ROUND_LEN, in_sync);
+    rc_->onNewRound((double)ROUND_LEN);
+
+    // update sync state if needed
+    if (current_state_ == SyncState::in_sync) {
+      double cache_rate = state_->getPacketFromCacheRatio();
+      if (cache_rate > MAX_DATA_FROM_CACHE) {
+        current_state_ = SyncState::catch_up;
+      }
+    } else {
+      double target_rate = state_->getProducerRate() * PRODUCTION_RATE_FRACTION;
+      double received_rate = state_->getReceivedRate();
+      uint32_t round_without_nacks = state_->getRoundsWithoutNacks();
+      double cache_ratio = state_->getPacketFromCacheRatio();
+      if (round_without_nacks >= ROUNDS_IN_SYNC_BEFORE_SWITCH &&
+          received_rate >= target_rate && cache_ratio < MAX_DATA_FROM_CACHE) {
+        current_state_ = SyncState::in_sync;
+      }
+    }
+
+    TRANSPORT_LOGD("Calling updateSyncWindow in newRound function");
+    updateSyncWindow();
+
+    sendStatsToApp(sent_retx, received_bytes, sent_interest, lost_data,
+                   recovered_losses, received_nacks);
+    newRound();
+  });
+}
+
+void RTCTransportProtocol::discoveredRtt() {
+  start_send_interest_ = true;
+  ldr_->turnOnRTX();
+  updateSyncWindow();
+}
+
+void RTCTransportProtocol::computeMaxSyncWindow() {
+  double production_rate = state_->getProducerRate();
+  double packet_size = state_->getAveragePacketSize();
+  if (production_rate == 0.0 || packet_size == 0.0) {
+    // the consumer has no info about the producer,
+    // keep the previous maxCWin
+    TRANSPORT_LOGD(
+        "Returning in computeMaxSyncWindow because: prod_rate: %d || "
+        "packet_size: %d",
+        (int)(production_rate == 0.0), (int)(packet_size == 0.0));
+    return;
+  }
+
+  uint32_t lifetime = default_values::interest_lifetime;
+  socket_->getSocketOption(GeneralTransportOptions::INTEREST_LIFETIME,
+                           lifetime);
+  double lifetime_ms = (double)lifetime / MILLI_IN_A_SEC;
+
+
+  max_sync_win_ =
+      (uint32_t)ceil((production_rate * lifetime_ms *
+            INTEREST_LIFETIME_REDUCTION_FACTOR) / packet_size);
+
+  max_sync_win_ = std::min(max_sync_win_, rc_->getCongesionWindow());
+}
+
+void RTCTransportProtocol::updateSyncWindow() {
+  computeMaxSyncWindow();
+
+  if (max_sync_win_ == INITIAL_WIN_MAX) {
+    if (TRANSPORT_EXPECT_FALSE(!state_->isProducerActive())) return;
+
+    current_sync_win_ = INITIAL_WIN;
+    scheduleNextInterests();
+    return;
+  }
+
+  double prod_rate = state_->getProducerRate();
+  double rtt = (double)state_->getRTT() / MILLI_IN_A_SEC;
+  double packet_size = state_->getAveragePacketSize();
+
+  // if some of the info are not available do not update the current win
+  if (prod_rate != 0.0 && rtt != 0.0 && packet_size != 0.0) {
+    current_sync_win_ = (uint32_t)ceil(prod_rate * rtt / packet_size);
+    current_sync_win_ +=
+        ceil(prod_rate * (PRODUCER_BUFFER_MS / MILLI_IN_A_SEC) / packet_size);
+
+    if(current_state_ == SyncState::catch_up) {
+      current_sync_win_ = current_sync_win_ * CATCH_UP_WIN_INCREMENT;
+    }
+
+    current_sync_win_ = std::min(current_sync_win_, max_sync_win_);
+    current_sync_win_ = std::max(current_sync_win_, WIN_MIN);
+  }
+
+  scheduleNextInterests();
+}
+
+void RTCTransportProtocol::decreaseSyncWindow() {
+  // called on future nack
+  // we have a new sample of the production rate, so update max win first
+  computeMaxSyncWindow();
+  current_sync_win_--;
+  current_sync_win_ = std::max(current_sync_win_, WIN_MIN);
+  scheduleNextInterests();
+}
+
+void RTCTransportProtocol::sendInterest(Name *interest_name) {
+  TRANSPORT_LOGD("Sending interest for name %s",
+                 interest_name->toString().c_str());
+
+  auto interest = core::PacketManager<>::getInstance().getPacket<Interest>();
+  interest->setName(*interest_name);
+
+  uint32_t lifetime = default_values::interest_lifetime;
+  socket_->getSocketOption(GeneralTransportOptions::INTEREST_LIFETIME,
+                           lifetime);
+  interest->setLifetime(uint32_t(lifetime));
+
+  if (*on_interest_output_) {
+    (*on_interest_output_)(*socket_->getInterface(), *interest);
+  }
+
+  if (TRANSPORT_EXPECT_FALSE(!is_running_ && !is_first_)) {
+    return;
+  }
+
+  portal_->sendInterest(std::move(interest));
+}
+
+void RTCTransportProtocol::sendRtxInterest(uint32_t seq) {
+  if (!is_running_ && !is_first_) return;
+
+  if(!start_send_interest_) return;
+
+  Name *interest_name = nullptr;
+  socket_->getSocketOption(GeneralTransportOptions::NETWORK_NAME,
+                           &interest_name);
+
+  TRANSPORT_LOGD("send rtx %u", seq);
+  interest_name->setSuffix(seq);
+  sendInterest(interest_name);
+}
+
+void RTCTransportProtocol::sendProbeInterest(uint32_t seq) {
+  if (!is_running_ && !is_first_) return;
+
+  Name *interest_name = nullptr;
+  socket_->getSocketOption(GeneralTransportOptions::NETWORK_NAME,
+                           &interest_name);
+
+  TRANSPORT_LOGD("send probe %u", seq);
+  interest_name->setSuffix(seq);
+  sendInterest(interest_name);
+}
+
+void RTCTransportProtocol::scheduleNextInterests() {
+  TRANSPORT_LOGD("Schedule next interests");
+
+  if (!is_running_ && !is_first_) return;
+
+  if(!start_send_interest_) return; // RTT discovering phase is not finished so
+                                    // do not start to send interests
+
+  if (scheduler_timer_on_) return;  // wait befor send other interests
+
+  if (TRANSPORT_EXPECT_FALSE(!state_->isProducerActive())) {
+    TRANSPORT_LOGD("Inactive producer.");
+    // here we keep seding the same interest until the producer
+    // does not start again
+    if (next_segment_ != 0) {
+      // the producer just become inactive, reset the state
+      inactiveProducer();
+    }
+
+    Name *interest_name = nullptr;
+    socket_->getSocketOption(GeneralTransportOptions::NETWORK_NAME,
+                             &interest_name);
+
+    TRANSPORT_LOGD("send interest %u", next_segment_);
+    interest_name->setSuffix(next_segment_);
+
+    if (portal_->interestIsPending(*interest_name)) {
+      // if interest 0 is already pending we return
+      return;
+    }
+
+    sendInterest(interest_name);
+    state_->onSendNewInterest(interest_name);
+    return;
+  }
+
+  TRANSPORT_LOGD("Pending interest number: %d -- current_sync_win_: %d",
+                 state_->getPendingInterestNumber(), current_sync_win_);
+
+  // skip nacked pacekts
+  if (next_segment_ <= state_->getLastSeqNacked()) {
+    next_segment_ = state_->getLastSeqNacked() + 1;
+  }
+
+  // skipe received packets
+  if (next_segment_ <= state_->getHighestSeqReceivedInOrder()) {
+    next_segment_ = state_->getHighestSeqReceivedInOrder() + 1;
+  }
+
+  uint32_t sent_interests = 0;
+  while ((state_->getPendingInterestNumber() < current_sync_win_) &&
+         (sent_interests < MAX_INTERESTS_IN_BATCH)) {
+    TRANSPORT_LOGD("In while loop. Window size: %u", current_sync_win_);
+    Name *interest_name = nullptr;
+    socket_->getSocketOption(GeneralTransportOptions::NETWORK_NAME,
+                             &interest_name);
+
+    interest_name->setSuffix(next_segment_);
+
+    // send the packet only if:
+    // 1) it is not pending yet (not true for rtx)
+    // 2) the packet is not received or lost
+    // 3) is not in the rtx list
+    if (portal_->interestIsPending(*interest_name) ||
+        state_->isReceivedOrLost(next_segment_) != PacketState::UNKNOWN ||
+        ldr_->isRtx(next_segment_)) {
+      TRANSPORT_LOGD(
+          "skip interest %u because: pending %u, recv %u, rtx %u",
+          next_segment_, (portal_->interestIsPending(*interest_name)),
+          (state_->isReceivedOrLost(next_segment_) != PacketState::UNKNOWN),
+          (ldr_->isRtx(next_segment_)));
+      next_segment_ = (next_segment_ + 1) % MIN_PROBE_SEQ;
+      continue;
+    }
+
+
+    sent_interests++;
+    TRANSPORT_LOGD("send interest %u", next_segment_);
+    sendInterest(interest_name);
+    state_->onSendNewInterest(interest_name);
+
+    next_segment_ = (next_segment_ + 1) % MIN_PROBE_SEQ;
+  }
+
+  if (state_->getPendingInterestNumber() < current_sync_win_) {
+    // we still have space in the window but we already sent a batch of
+    // MAX_INTERESTS_IN_BATCH interest. for the following ones wait one
+    // WAIT_BETWEEN_INTEREST_BATCHES to avoid local packets drop
+
+    scheduler_timer_on_ = true;
+    scheduler_timer_->expires_from_now(
+        std::chrono::microseconds(WAIT_BETWEEN_INTEREST_BATCHES));
+    scheduler_timer_->async_wait([this](std::error_code ec) {
+      if (ec) return;
+      if (!scheduler_timer_on_) return;
+
+      scheduler_timer_on_ = false;
+      scheduleNextInterests();
+    });
+  }
+}
+
+void RTCTransportProtocol::onTimeout(Interest::Ptr &&interest) {
+  uint32_t segment_number = interest->getName().getSuffix();
+
+  TRANSPORT_LOGD("timeout for packet  %u", segment_number);
+
+  if (segment_number >= MIN_PROBE_SEQ) {
+    // this is a timeout on a probe, do nothing
+    return;
+  }
+
+  timeouts_or_nacks_.insert(segment_number);
+
+  if (TRANSPORT_EXPECT_TRUE(state_->isProducerActive()) &&
+      segment_number <= state_->getHighestSeqReceivedInOrder()) {
+    // we retransmit packets only if the producer is active, otherwise we
+    // use timeouts to avoid to send too much traffic
+    //
+    // a timeout is sent using RTX only if it is an old packet. if it is for a
+    // seq number that we didn't reach yet, we send the packet using the normal
+    // schedule next interest
+    TRANSPORT_LOGD("handle timeout for packet  %u using rtx", segment_number);
+    ldr_->onTimeout(segment_number);
+    state_->onTimeout(segment_number);
+    scheduleNextInterests();
+    return;
+  }
+
+  TRANSPORT_LOGD("handle timeout for packet  %u using normal interests",
+                 segment_number);
+
+  if (segment_number < next_segment_) {
+    // this is a timeout for a packet that will be generated in the future but
+    // we are asking for higher sequence numbers. we need to go back like in the
+    // case of future nacks
+    TRANSPORT_LOGD("on timeout next seg = %u, jump to %u",
+                    next_segment_, segment_number);
+    next_segment_ = segment_number;
+  }
+
+  state_->onTimeout(segment_number);
+  scheduleNextInterests();
+}
+
+void RTCTransportProtocol::onNack(const ContentObject &content_object) {
+  struct nack_packet_t *nack =
+      (struct nack_packet_t *)content_object.getPayload()->data();
+  uint32_t production_seg = nack->getProductionSegement();
+  uint32_t nack_segment = content_object.getName().getSuffix();
+  bool is_rtx = ldr_->isRtx(nack_segment);
+
+  // check if the packet got a timeout
+
+  TRANSPORT_LOGD("Nack received %u. Production segment: %u", nack_segment,
+                 production_seg);
+
+  bool compute_stats = true;
+  auto tn_it = timeouts_or_nacks_.find(nack_segment);
+  if (tn_it != timeouts_or_nacks_.end() || is_rtx) {
+    compute_stats = false;
+    // remove packets from timeouts_or_nacks only in case of a past nack
+  }
+
+  state_->onNackPacketReceived(content_object, compute_stats);
+  ldr_->onNackPacketReceived(content_object);
+
+  // both in case of past and future nack we set next_segment_ equal to the
+  // production segment in the nack. In case of past nack we will skip unneded
+  // interest (this is already done in the scheduleNextInterest in any case)
+  // while in case of future nacks we can go back in time and ask again for the
+  // content that generated the nack
+  TRANSPORT_LOGD("on nack next seg = %u, jump to %u",
+                  next_segment_, production_seg);
+  next_segment_ = production_seg;
+
+  if (production_seg > nack_segment) {
+    // remove the nack is it exists
+    if (tn_it != timeouts_or_nacks_.end()) timeouts_or_nacks_.erase(tn_it);
+
+    // the client is asking for content in the past
+    // switch to catch up state and increase the window
+    // this is true only if the packet is not an RTX
+    if (!is_rtx) current_state_ = SyncState::catch_up;
+
+    updateSyncWindow();
+  } else {
+    // if production_seg == nack_segment we consider this a future nack, since
+    // production_seg is not yet created. this may happen in case of low
+    // production rate (e.g. ping at 1pps)
+
+    // if a future nack was also retransmitted add it to the timeout_or_nacks
+    // set
+    if (is_rtx) timeouts_or_nacks_.insert(nack_segment);
+
+    // the client is asking for content in the future
+    // switch to in sync state and decrease the window
+    current_state_ = SyncState::in_sync;
+    decreaseSyncWindow();
+  }
+}
+
+void RTCTransportProtocol::onProbe(const ContentObject &content_object) {
+  bool valid = state_->onProbePacketReceived(content_object);
+  if(!valid) return;
+
+  struct nack_packet_t *probe =
+      (struct nack_packet_t *)content_object.getPayload()->data();
+  uint32_t production_seg = probe->getProductionSegement();
+
+  // as for the nacks set next_segment_
+  TRANSPORT_LOGD("on probe next seg = %u, jump to %u",
+                  next_segment_, production_seg);
+  next_segment_ = production_seg;
+
+  ldr_->onProbePacketReceived(content_object);
+  updateSyncWindow();
+}
+
+void RTCTransportProtocol::onContentObject(Interest &interest,
+                                           ContentObject &content_object) {
+  TRANSPORT_LOGD("Received content object of size: %zu",
+                 content_object.payloadSize());
+  uint32_t payload_size = content_object.payloadSize();
+  uint32_t segment_number = content_object.getName().getSuffix();
+
+  if (segment_number >= MIN_PROBE_SEQ) {
+    TRANSPORT_LOGD("Received probe %u", segment_number);
+    if (*on_content_object_input_) {
+      (*on_content_object_input_)(*socket_->getInterface(), content_object);
+    }
+    onProbe(content_object);
+    return;
+  }
+
+  if (payload_size == NACK_HEADER_SIZE) {
+    TRANSPORT_LOGD("Received nack %u", segment_number);
+    if (*on_content_object_input_) {
+      (*on_content_object_input_)(*socket_->getInterface(), content_object);
+    }
+    onNack(content_object);
+    return;
+  }
+
+  TRANSPORT_LOGD("Received content %u", segment_number);
+
+  rc_->onDataPacketReceived(content_object);
+  bool compute_stats = true;
+  auto tn_it = timeouts_or_nacks_.find(segment_number);
+  if (tn_it != timeouts_or_nacks_.end()) {
+    compute_stats = false;
+    timeouts_or_nacks_.erase(tn_it);
+  }
+  if (ldr_->isRtx(segment_number)) {
+    compute_stats = false;
+  }
+
+  // check if the packet was already received
+  PacketState state = state_->isReceivedOrLost(segment_number);
+  state_->onDataPacketReceived(content_object, compute_stats);
+  ldr_->onDataPacketReceived(content_object);
+
+  // if the stat for this seq number is received do not send the packet to app
+  if (state != PacketState::RECEIVED) {
+    if (*on_content_object_input_) {
+      (*on_content_object_input_)(*socket_->getInterface(), content_object);
+    }
+    reassemble(content_object);
+  } else {
+    TRANSPORT_LOGD("Received duplicated content %u, drop it", segment_number);
+  }
+
+  updateSyncWindow();
+}
+
+void RTCTransportProtocol::sendStatsToApp(
+    uint32_t retx_count, uint32_t received_bytes, uint32_t sent_interests,
+    uint32_t lost_data, uint32_t recovered_losses, uint32_t received_nacks) {
+  if (*stats_summary_) {
+    // Send the stats to the app
+    stats_->updateQueuingDelay(state_->getQueuing());
+
+    // stats_->updateInterestFecTx(0); //todo must be implemented
+    // stats_->updateBytesFecRecv(0); //todo must be implemented
+
+    stats_->updateRetxCount(retx_count);
+    stats_->updateBytesRecv(received_bytes);
+    stats_->updateInterestTx(sent_interests);
+    stats_->updateReceivedNacks(received_nacks);
+
+    stats_->updateAverageWindowSize(current_sync_win_);
+    stats_->updateLossRatio(state_->getLossRate());
+    stats_->updateAverageRtt(state_->getRTT());
+    stats_->updateLostData(lost_data);
+    stats_->updateRecoveredData(recovered_losses);
+    stats_->updateCCState((unsigned int)current_state_ ? 1 : 0);
+    (*stats_summary_)(*socket_->getInterface(), *stats_);
+  }
+}
+
+void RTCTransportProtocol::reassemble(ContentObject &content_object) {
+  auto read_buffer = content_object.getPayload();
+  TRANSPORT_LOGD("Size of payload: %zu", read_buffer->length());
+  read_buffer->trimStart(DATA_HEADER_SIZE);
+  Reassembly::read_buffer_ = std::move(read_buffer);
+  Reassembly::notifyApplication();
+}
+
+}  // end namespace rtc
+
+}  // end namespace protocol
+
+}  // end namespace transport