self-learning-strategy.cpp
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1 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
2 /*
3  * Copyright (c) 2014-2019, Regents of the University of California,
4  * Arizona Board of Regents,
5  * Colorado State University,
6  * University Pierre & Marie Curie, Sorbonne University,
7  * Washington University in St. Louis,
8  * Beijing Institute of Technology,
9  * The University of Memphis.
10  *
11  * This file is part of NFD (Named Data Networking Forwarding Daemon).
12  * See AUTHORS.md for complete list of NFD authors and contributors.
13  *
14  * NFD is free software: you can redistribute it and/or modify it under the terms
15  * of the GNU General Public License as published by the Free Software Foundation,
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20  * PURPOSE. See the GNU General Public License for more details.
21  *
22  * You should have received a copy of the GNU General Public License along with
23  * NFD, e.g., in COPYING.md file. If not, see <http://www.gnu.org/licenses/>.
24  */
25 
27 #include "algorithm.hpp"
28 
29 #include "common/global.hpp"
30 #include "common/logger.hpp"
31 #include "rib/service.hpp"
32 
33 #include <ndn-cxx/lp/empty-value.hpp>
34 #include <ndn-cxx/lp/prefix-announcement-header.hpp>
35 #include <ndn-cxx/lp/tags.hpp>
36 
37 #include <boost/range/adaptor/reversed.hpp>
38 
39 namespace nfd {
40 namespace fw {
41 
42 NFD_LOG_INIT(SelfLearningStrategy);
43 NFD_REGISTER_STRATEGY(SelfLearningStrategy);
44 
45 const time::milliseconds SelfLearningStrategy::ROUTE_RENEW_LIFETIME(10_min);
46 
48  : Strategy(forwarder)
49 {
51  if (!parsed.parameters.empty()) {
52  NDN_THROW(std::invalid_argument("SelfLearningStrategy does not accept parameters"));
53  }
54  if (parsed.version && *parsed.version != getStrategyName()[-1].toVersion()) {
55  NDN_THROW(std::invalid_argument(
56  "SelfLearningStrategy does not support version " + to_string(*parsed.version)));
57  }
59 }
60 
61 const Name&
63 {
64  static Name strategyName("/localhost/nfd/strategy/self-learning/%FD%01");
65  return strategyName;
66 }
67 
68 void
69 SelfLearningStrategy::afterReceiveInterest(const FaceEndpoint& ingress, const Interest& interest,
70  const shared_ptr<pit::Entry>& pitEntry)
71 {
72  const fib::Entry& fibEntry = this->lookupFib(*pitEntry);
73  const fib::NextHopList& nexthops = fibEntry.getNextHops();
74 
75  bool isNonDiscovery = interest.getTag<lp::NonDiscoveryTag>() != nullptr;
76  auto inRecordInfo = pitEntry->getInRecord(ingress.face)->insertStrategyInfo<InRecordInfo>().first;
77  if (isNonDiscovery) { // "non-discovery" Interest
78  inRecordInfo->isNonDiscoveryInterest = true;
79  if (nexthops.empty()) { // return NACK if no matching FIB entry exists
80  NFD_LOG_DEBUG("NACK non-discovery Interest=" << interest << " from=" << ingress << " noNextHop");
81  lp::NackHeader nackHeader;
82  nackHeader.setReason(lp::NackReason::NO_ROUTE);
83  this->sendNack(pitEntry, ingress, nackHeader);
84  this->rejectPendingInterest(pitEntry);
85  }
86  else { // multicast it if matching FIB entry exists
87  multicastInterest(interest, ingress.face, pitEntry, nexthops);
88  }
89  }
90  else { // "discovery" Interest
91  inRecordInfo->isNonDiscoveryInterest = false;
92  if (nexthops.empty()) { // broadcast it if no matching FIB entry exists
93  broadcastInterest(interest, ingress.face, pitEntry);
94  }
95  else { // multicast it with "non-discovery" mark if matching FIB entry exists
96  interest.setTag(make_shared<lp::NonDiscoveryTag>(lp::EmptyValue{}));
97  multicastInterest(interest, ingress.face, pitEntry, nexthops);
98  }
99  }
100 }
101 
102 void
103 SelfLearningStrategy::afterReceiveData(const shared_ptr<pit::Entry>& pitEntry,
104  const FaceEndpoint& ingress, const Data& data)
105 {
106  auto outRecord = pitEntry->getOutRecord(ingress.face);
107  if (outRecord == pitEntry->out_end()) {
108  NFD_LOG_DEBUG("Data " << data.getName() << " from=" << ingress << " no out-record");
109  return;
110  }
111 
112  OutRecordInfo* outRecordInfo = outRecord->getStrategyInfo<OutRecordInfo>();
113  if (outRecordInfo && outRecordInfo->isNonDiscoveryInterest) { // outgoing Interest was non-discovery
114  if (!needPrefixAnn(pitEntry)) { // no need to attach a PA (common cases)
115  sendDataToAll(pitEntry, ingress, data);
116  }
117  else { // needs a PA (to respond discovery Interest)
118  asyncProcessData(pitEntry, ingress.face, data);
119  }
120  }
121  else { // outgoing Interest was discovery
122  auto paTag = data.getTag<lp::PrefixAnnouncementTag>();
123  if (paTag != nullptr) {
124  addRoute(pitEntry, ingress.face, data, *paTag->get().getPrefixAnn());
125  }
126  else { // Data contains no PrefixAnnouncement, upstreams do not support self-learning
127  }
128  sendDataToAll(pitEntry, ingress, data);
129  }
130 }
131 
132 void
133 SelfLearningStrategy::afterReceiveNack(const FaceEndpoint& ingress, const lp::Nack& nack,
134  const shared_ptr<pit::Entry>& pitEntry)
135 {
136  NFD_LOG_DEBUG("Nack for " << nack.getInterest() << " from=" << ingress
137  << " reason=" << nack.getReason());
138  if (nack.getReason() == lp::NackReason::NO_ROUTE) { // remove FIB entries
139  BOOST_ASSERT(this->lookupFib(*pitEntry).hasNextHops());
140  NFD_LOG_DEBUG("Send NACK to all downstreams");
141  this->sendNacks(pitEntry, nack.getHeader());
142  renewRoute(nack.getInterest().getName(), ingress.face.getId(), 0_ms);
143  }
144 }
145 
146 void
147 SelfLearningStrategy::broadcastInterest(const Interest& interest, const Face& inFace,
148  const shared_ptr<pit::Entry>& pitEntry)
149 {
150  for (auto& outFace : this->getFaceTable() | boost::adaptors::reversed) {
151  if ((outFace.getId() == inFace.getId() && outFace.getLinkType() != ndn::nfd::LINK_TYPE_AD_HOC) ||
152  wouldViolateScope(inFace, interest, outFace) || outFace.getScope() == ndn::nfd::FACE_SCOPE_LOCAL) {
153  continue;
154  }
155  this->sendInterest(pitEntry, FaceEndpoint(outFace, 0), interest);
156  pitEntry->getOutRecord(outFace)->insertStrategyInfo<OutRecordInfo>().first->isNonDiscoveryInterest = false;
157  NFD_LOG_DEBUG("send discovery Interest=" << interest << " from="
158  << inFace.getId() << " to=" << outFace.getId());
159  }
160 }
161 
162 void
163 SelfLearningStrategy::multicastInterest(const Interest& interest, const Face& inFace,
164  const shared_ptr<pit::Entry>& pitEntry,
165  const fib::NextHopList& nexthops)
166 {
167  for (const auto& nexthop : nexthops) {
168  Face& outFace = nexthop.getFace();
169  if ((outFace.getId() == inFace.getId() && outFace.getLinkType() != ndn::nfd::LINK_TYPE_AD_HOC) ||
170  wouldViolateScope(inFace, interest, outFace)) {
171  continue;
172  }
173  this->sendInterest(pitEntry, FaceEndpoint(outFace, 0), interest);
174  pitEntry->getOutRecord(outFace)->insertStrategyInfo<OutRecordInfo>().first->isNonDiscoveryInterest = true;
175  NFD_LOG_DEBUG("send non-discovery Interest=" << interest << " from="
176  << inFace.getId() << " to=" << outFace.getId());
177  }
178 }
179 
180 void
181 SelfLearningStrategy::asyncProcessData(const shared_ptr<pit::Entry>& pitEntry, const Face& inFace, const Data& data)
182 {
183  // Given that this processing is asynchronous, the PIT entry's expiry timer is extended first
184  // to ensure that the entry will not be removed before the whole processing is finished
185  // (the PIT entry's expiry timer was set to 0 before dispatching)
186  this->setExpiryTimer(pitEntry, 1_s);
187 
188  runOnRibIoService([pitEntryWeak = weak_ptr<pit::Entry>{pitEntry}, inFaceId = inFace.getId(), data, this] {
189  rib::Service::get().getRibManager().slFindAnn(data.getName(),
190  [pitEntryWeak, inFaceId, data, this] (optional<ndn::PrefixAnnouncement> paOpt) {
191  if (paOpt) {
192  runOnMainIoService([pitEntryWeak, inFaceId, data, pa = std::move(*paOpt), this] {
193  auto pitEntry = pitEntryWeak.lock();
194  auto inFace = this->getFace(inFaceId);
195  if (pitEntry && inFace) {
196  NFD_LOG_DEBUG("found PrefixAnnouncement=" << pa.getAnnouncedName());
197  data.setTag(make_shared<lp::PrefixAnnouncementTag>(lp::PrefixAnnouncementHeader(pa)));
198  this->sendDataToAll(pitEntry, FaceEndpoint(*inFace, 0), data);
199  this->setExpiryTimer(pitEntry, 0_ms);
200  }
201  else {
202  NFD_LOG_DEBUG("PIT entry or Face no longer exists");
203  }
204  });
205  }
206  });
207  });
208 }
209 
210 bool
211 SelfLearningStrategy::needPrefixAnn(const shared_ptr<pit::Entry>& pitEntry)
212 {
213  bool hasDiscoveryInterest = false;
214  bool directToConsumer = true;
215 
216  auto now = time::steady_clock::now();
217  for (const auto& inRecord : pitEntry->getInRecords()) {
218  if (inRecord.getExpiry() > now) {
219  InRecordInfo* inRecordInfo = inRecord.getStrategyInfo<InRecordInfo>();
220  if (inRecordInfo && !inRecordInfo->isNonDiscoveryInterest) {
221  hasDiscoveryInterest = true;
222  }
223  if (inRecord.getFace().getScope() != ndn::nfd::FACE_SCOPE_LOCAL) {
224  directToConsumer = false;
225  }
226  }
227  }
228  return hasDiscoveryInterest && !directToConsumer;
229 }
230 
231 void
232 SelfLearningStrategy::addRoute(const shared_ptr<pit::Entry>& pitEntry, const Face& inFace,
233  const Data& data, const ndn::PrefixAnnouncement& pa)
234 {
235  runOnRibIoService([pitEntryWeak = weak_ptr<pit::Entry>{pitEntry}, inFaceId = inFace.getId(), data, pa] {
236  rib::Service::get().getRibManager().slAnnounce(pa, inFaceId, ROUTE_RENEW_LIFETIME,
238  NFD_LOG_DEBUG("Add route via PrefixAnnouncement with result=" << res);
239  });
240  });
241 }
242 
243 void
244 SelfLearningStrategy::renewRoute(const Name& name, FaceId inFaceId, time::milliseconds maxLifetime)
245 {
246  // renew route with PA or ignore PA (if route has no PA)
247  runOnRibIoService([name, inFaceId, maxLifetime] {
248  rib::Service::get().getRibManager().slRenew(name, inFaceId, maxLifetime,
250  NFD_LOG_DEBUG("Renew route with result=" << res);
251  });
252  });
253 }
254 
255 } // namespace fw
256 } // namespace nfd
Main class of NFD&#39;s forwarding engine.
Definition: forwarder.hpp:51
void setInstanceName(const Name &name)
set strategy instance name
Definition: strategy.hpp:382
static Service & get()
Get a reference to the only instance of this class.
Definition: service.cpp:139
const FaceTable & getFaceTable() const
Definition: strategy.hpp:345
RibManager & getRibManager()
Definition: service.hpp:90
void afterReceiveData(const shared_ptr< pit::Entry > &pitEntry, const FaceEndpoint &ingress, const Data &data) override
trigger after Data is received
void slAnnounce(const ndn::PrefixAnnouncement &pa, uint64_t faceId, time::milliseconds maxLifetime, const SlAnnounceCallback &cb)
Insert a route by prefix announcement from self-learning strategy.
void runOnRibIoService(const std::function< void()> &f)
Run a function on the RIB io_service instance.
Definition: global.cpp:95
void sendNack(const shared_ptr< pit::Entry > &pitEntry, const FaceEndpoint &egress, const lp::NackHeader &header)
send Nack to egress
Definition: strategy.hpp:302
represents a FIB entry
Definition: fib-entry.hpp:53
void sendDataToAll(const shared_ptr< pit::Entry > &pitEntry, const FaceEndpoint &ingress, const Data &data)
send data to all matched and qualified face-endpoint pairs
Definition: strategy.cpp:242
static Name makeInstanceName(const Name &input, const Name &strategyName)
construct a strategy instance name
Definition: strategy.cpp:134
void slRenew(const Name &name, uint64_t faceId, time::milliseconds maxLifetime, const SlAnnounceCallback &cb)
Renew a route created by prefix announcement from self-learning strategy.
void runOnMainIoService(const std::function< void()> &f)
Run a function on the main io_service instance.
Definition: global.cpp:89
void sendInterest(const shared_ptr< pit::Entry > &pitEntry, const FaceEndpoint &egress, const Interest &interest)
send Interest to egress
Definition: strategy.cpp:197
Represents a face-endpoint pair in the forwarder.
Copyright (c) 2014-2015, Regents of the University of California, Arizona Board of Regents...
Definition: algorithm.hpp:32
void setExpiryTimer(const shared_ptr< pit::Entry > &pitEntry, time::milliseconds duration)
Schedule the PIT entry to be erased after duration.
Definition: strategy.hpp:321
Represents a collection of nexthops.
Definition: fib-entry.hpp:39
PartialName parameters
parameter components
Definition: strategy.hpp:355
represents a forwarding strategy
Definition: strategy.hpp:37
This file contains common algorithms used by forwarding strategies.
void slFindAnn(const Name &name, const SlFindAnnCallback &cb) const
Retrieve an outgoing prefix announcement for self-learning strategy.
#define NFD_LOG_DEBUG
Definition: logger.hpp:38
#define NFD_LOG_INIT(name)
Definition: logger.hpp:31
static ParsedInstanceName parseInstanceName(const Name &input)
parse a strategy instance name
Definition: strategy.cpp:123
void afterReceiveNack(const FaceEndpoint &ingress, const lp::Nack &nack, const shared_ptr< pit::Entry > &pitEntry) override
trigger after Nack is received
void afterReceiveInterest(const FaceEndpoint &ingress, const Interest &interest, const shared_ptr< pit::Entry > &pitEntry) override
trigger after Interest is received
SelfLearningStrategy(Forwarder &forwarder, const Name &name=getStrategyName())
NFD_REGISTER_STRATEGY(SelfLearningStrategy)
void sendNacks(const shared_ptr< pit::Entry > &pitEntry, const lp::NackHeader &header, std::initializer_list< FaceEndpoint > exceptFaceEndpoints={})
send Nack to every face-endpoint pair that has an in-record, except those in exceptFaceEndpoints ...
Definition: strategy.cpp:265
bool wouldViolateScope(const Face &inFace, const Interest &interest, const Face &outFace)
determine whether forwarding the Interest in pitEntry to outFace would violate scope ...
Definition: algorithm.cpp:32
const NextHopList & getNextHops() const
Definition: fib-entry.hpp:66
uint64_t FaceId
Identifies a face.
Definition: face-common.hpp:44
Face * getFace(FaceId id) const
Definition: strategy.hpp:339
void rejectPendingInterest(const shared_ptr< pit::Entry > &pitEntry)
schedule the PIT entry for immediate deletion
Definition: strategy.hpp:289
const fib::Entry & lookupFib(const pit::Entry &pitEntry) const
performs a FIB lookup, considering Link object if present
Definition: strategy.cpp:288
bool hasNextHops() const
Definition: fib-entry.hpp:74
optional< uint64_t > version
whether strategyName contains a version component
Definition: strategy.hpp:354