[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, 253 insertions, 0 deletions

diff --git a/libtransport/src/protocols/rtc/rtc_state.h b/libtransport/src/protocols/rtc/rtc_state.h
new file mode 100644
index 000000000..943a0a113
--- /dev/null
+++ b/libtransport/src/protocols/rtc/rtc_state.h
@@ -0,0 +1,253 @@
+/*
+ * Copyright (c) 2017-2021 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.
+ */
+
+#pragma once
+#include <hicn/transport/config.h>
+#include <hicn/transport/core/content_object.h>
+#include <hicn/transport/core/name.h>
+#include <protocols/rtc/probe_handler.h>
+#include <protocols/rtc/rtc_data_path.h>
+
+#include <asio.hpp>
+#include <asio/steady_timer.hpp>
+#include <map>
+#include <set>
+
+namespace transport {
+
+namespace protocol {
+
+namespace rtc {
+
+enum class PacketState : uint8_t { RECEIVED, LOST, UNKNOWN };
+
+class RTCState : std::enable_shared_from_this<RTCState> {
+ public:
+  using DiscoveredRttCallback = std::function<void()>;
+ public:
+  RTCState(ProbeHandler::SendProbeCallback &&rtt_probes_callback,
+           DiscoveredRttCallback &&discovered_rtt_callback,
+           asio::io_service &io_service);
+
+  ~RTCState();
+
+  // packet events
+  void onSendNewInterest(const core::Name *interest_name);
+  void onTimeout(uint32_t seq);
+  void onRetransmission(uint32_t seq);
+  void onDataPacketReceived(const core::ContentObject &content_object,
+                            bool compute_stats);
+  void onNackPacketReceived(const core::ContentObject &nack,
+                            bool compute_stats);
+  void onPacketLost(uint32_t seq);
+  void onPacketRecovered(uint32_t seq);
+  bool onProbePacketReceived(const core::ContentObject &probe);
+
+  // protocol state
+  void onNewRound(double round_len, bool in_sync);
+
+  // main path
+  uint32_t getProducerPath() const {
+    if (mainPathIsValid()) return main_path_->getPathId();
+    return 0;
+  }
+
+  // delay metrics
+  bool isRttDiscovered() const {
+    return init_rtt_;
+  }
+
+  uint64_t getRTT() const {
+    if (mainPathIsValid()) return main_path_->getMinRtt();
+    return 0;
+  }
+  void resetRttStats() {
+    if (mainPathIsValid()) main_path_->clearRtt();
+  }
+
+  double getQueuing() const {
+    if (mainPathIsValid()) return main_path_->getQueuingDealy();
+    return 0.0;
+  }
+  double getIAT() const {
+    if (mainPathIsValid()) return main_path_->getInterArrivalGap();
+    return 0.0;
+  }
+
+  double getJitter() const {
+    if (mainPathIsValid()) return main_path_->getJitter();
+    return 0.0;
+  }
+
+  // pending interests
+  uint64_t getInterestSentTime(uint32_t seq) {
+    auto it = pending_interests_.find(seq);
+    if (it != pending_interests_.end()) return it->second;
+    return 0;
+  }
+  bool isPending(uint32_t seq) {
+    if (pending_interests_.find(seq) != pending_interests_.end()) return true;
+    return false;
+  }
+  uint32_t getPendingInterestNumber() const {
+    return pending_interests_.size();
+  }
+  PacketState isReceivedOrLost(uint32_t seq) {
+    auto it = received_or_lost_packets_.find(seq);
+    if (it != received_or_lost_packets_.end()) return it->second;
+    return PacketState::UNKNOWN;
+  }
+
+  // loss rate
+  double getLossRate() const { return loss_rate_; }
+  double getResidualLossRate() const { return residual_loss_rate_; }
+  uint32_t getHighestSeqReceivedInOrder() const {
+    return highest_seq_received_in_order_;
+  }
+  uint32_t getLostData() const { return packets_lost_; };
+  uint32_t getRecoveredLosses() const { return losses_recovered_; }
+
+  // generic stats
+  uint32_t getReceivedBytesInRound() const { return received_bytes_; }
+  uint32_t getReceivedNacksInRound() const {
+    return received_nacks_last_round_;
+  }
+  uint32_t getSentInterestInRound() const { return sent_interests_last_round_; }
+  uint32_t getSentRtxInRound() const { return sent_rtx_last_round_; }
+
+  // bandwidth/production metrics
+  double getAvailableBw() const { return 0.0; };  // TODO
+  double getProducerRate() const { return production_rate_; }
+  double getReceivedRate() const { return received_rate_; }
+  double getAveragePacketSize() const { return avg_packet_size_; }
+
+  // nacks
+  uint32_t getRoundsWithoutNacks() const { return rounds_without_nacks_; }
+  uint32_t getLastSeqNacked() const { return last_seq_nacked_; }
+
+  // producer state
+  bool isProducerActive() const { return producer_is_active_; }
+
+  // packets from cache
+  double getPacketFromCacheRatio() const { return data_from_cache_rate_; }
+
+  std::map<uint32_t, uint64_t>::iterator getPendingInterestsMapBegin() {
+    return pending_interests_.begin();
+  }
+  std::map<uint32_t, uint64_t>::iterator getPendingInterestsMapEnd() {
+    return pending_interests_.end();
+  }
+
+ private:
+  void initParams();
+
+  // update stats
+  void updateState();
+  void updateReceivedBytes(const core::ContentObject &content_object);
+  void updatePacketSize(const core::ContentObject &content_object);
+  void updatePathStats(const core::ContentObject &content_object, bool is_nack);
+  void updateLossRate();
+
+  void addRecvOrLost(uint32_t seq, PacketState state);
+
+  void setInitRttTimer(uint32_t wait);
+  void checkInitRttTimer();
+
+  bool mainPathIsValid() const {
+    if (main_path_ != nullptr)
+      return true;
+    else
+      return false;
+  }
+
+  // packets counters (total)
+  uint32_t sent_interests_;
+  uint32_t sent_rtx_;
+  uint32_t received_data_;
+  uint32_t received_nacks_;
+  uint32_t received_timeouts_;
+  uint32_t received_probes_;
+
+  // loss counters
+  int32_t packets_lost_;
+  int32_t losses_recovered_;
+  uint32_t first_seq_in_round_;
+  uint32_t highest_seq_received_;
+  uint32_t highest_seq_received_in_order_;
+  uint32_t last_seq_nacked_;  // segment for which we got an oldNack
+  double loss_rate_;
+  double residual_loss_rate_;
+
+  // bw counters
+  uint32_t received_bytes_;
+  double avg_packet_size_;
+  double production_rate_;  // rate communicated by the producer using nacks
+  double received_rate_;    // rate recevied by the consumer
+
+  // nack counter
+  // the bool takes tracks only about the valid nacks (no rtx) and it is used to
+  // switch between the states. Instead received_nacks_last_round_ logs all the
+  // nacks for statistics
+  bool nack_on_last_round_;
+  uint32_t received_nacks_last_round_;
+
+  // packets counter
+  uint32_t received_packets_last_round_;
+  uint32_t received_data_last_round_;
+  uint32_t received_data_from_cache_;
+  double data_from_cache_rate_;
+  uint32_t sent_interests_last_round_;
+  uint32_t sent_rtx_last_round_;
+
+  // round conunters
+  uint32_t rounds_;
+  uint32_t rounds_without_nacks_;
+  uint32_t rounds_without_packets_;
+
+  // init rtt
+  uint64_t first_interest_sent_;
+
+  // producer state
+  bool
+      producer_is_active_;  // the prodcuer is active if we receive some packets
+  uint32_t last_production_seq_; // last production seq received by the producer
+  uint64_t last_prod_update_;  // timestamp of the last packets used to update
+                               // stats from the producer
+
+  // paths stats
+  std::unordered_map<uint32_t, std::shared_ptr<RTCDataPath>> path_table_;
+  std::shared_ptr<RTCDataPath> main_path_;
+
+  // packet received
+  // cache where to store info about the last MAX_CACHED_PACKETS
+  std::map<uint32_t, PacketState> received_or_lost_packets_;
+
+  // pending interests
+  std::map<uint32_t, uint64_t> pending_interests_;
+
+  // probes
+  std::shared_ptr<ProbeHandler> rtt_probes_;
+  bool init_rtt_;
+  std::unique_ptr<asio::steady_timer> init_rtt_timer_;
+
+  // callbacks
+  DiscoveredRttCallback discovered_rtt_callback_;
+};
+
+}  // namespace rtc
+
+}  // namespace protocol
+
+}  // namespace transport