NS-3 based Named Data Networking (NDN) simulator
ndnSIM 2.5: NDN, CCN, CCNx, content centric networks
API Documentation
best-route-strategy.cpp
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1 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
2 /*
3  * Copyright (c) 2014-2021, 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 
26 #include "best-route-strategy.hpp"
27 #include "algorithm.hpp"
28 #include "common/logger.hpp"
29 
30 namespace nfd {
31 namespace fw {
32 
35 
36 const time::milliseconds BestRouteStrategy::RETX_SUPPRESSION_INITIAL(10);
38 
40  : Strategy(forwarder)
41  , ProcessNackTraits(this)
42  , m_retxSuppression(RETX_SUPPRESSION_INITIAL,
43  RetxSuppressionExponential::DEFAULT_MULTIPLIER,
44  RETX_SUPPRESSION_MAX)
45 {
47  if (!parsed.parameters.empty()) {
48  NDN_THROW(std::invalid_argument("BestRouteStrategy does not accept parameters"));
49  }
50  if (parsed.version && *parsed.version != getStrategyName()[-1].toVersion()) {
51  NDN_THROW(std::invalid_argument(
52  "BestRouteStrategy does not support version " + to_string(*parsed.version)));
53  }
55 }
56 
57 const Name&
59 {
60  static const auto strategyName = Name("/localhost/nfd/strategy/best-route").appendVersion(5);
61  return strategyName;
62 }
63 
64 void
66  const shared_ptr<pit::Entry>& pitEntry)
67 {
69  if (suppression == RetxSuppressionResult::SUPPRESS) {
70  NFD_LOG_DEBUG(interest << " from=" << ingress << " suppressed");
71  return;
72  }
73 
74  const fib::Entry& fibEntry = this->lookupFib(*pitEntry);
75  const fib::NextHopList& nexthops = fibEntry.getNextHops();
76  auto it = nexthops.end();
77 
78  if (suppression == RetxSuppressionResult::NEW) {
79  // forward to nexthop with lowest cost except downstream
80  it = std::find_if(nexthops.begin(), nexthops.end(), [&] (const auto& nexthop) {
81  return isNextHopEligible(ingress.face, interest, nexthop, pitEntry);
82  });
83 
84  if (it == nexthops.end()) {
85  NFD_LOG_DEBUG(interest << " from=" << ingress << " noNextHop");
86 
87  lp::NackHeader nackHeader;
88  nackHeader.setReason(lp::NackReason::NO_ROUTE);
89  this->sendNack(nackHeader, ingress.face, pitEntry);
90  this->rejectPendingInterest(pitEntry);
91  return;
92  }
93 
94  Face& outFace = it->getFace();
95  NFD_LOG_DEBUG(interest << " from=" << ingress << " newPitEntry-to=" << outFace.getId());
96  this->sendInterest(interest, outFace, pitEntry);
97  return;
98  }
99 
100  // find an unused upstream with lowest cost except downstream
101  it = std::find_if(nexthops.begin(), nexthops.end(),
102  [&, now = time::steady_clock::now()] (const auto& nexthop) {
103  return isNextHopEligible(ingress.face, interest, nexthop, pitEntry, true, now);
104  });
105 
106  if (it != nexthops.end()) {
107  Face& outFace = it->getFace();
108  this->sendInterest(interest, outFace, pitEntry);
109  NFD_LOG_DEBUG(interest << " from=" << ingress << " retransmit-unused-to=" << outFace.getId());
110  return;
111  }
112 
113  // find an eligible upstream that is used earliest
114  it = findEligibleNextHopWithEarliestOutRecord(ingress.face, interest, nexthops, pitEntry);
115  if (it == nexthops.end()) {
116  NFD_LOG_DEBUG(interest << " from=" << ingress << " retransmitNoNextHop");
117  }
118  else {
119  Face& outFace = it->getFace();
120  this->sendInterest(interest, outFace, pitEntry);
121  NFD_LOG_DEBUG(interest << " from=" << ingress << " retransmit-retry-to=" << outFace.getId());
122  }
123 }
124 
125 void
127  const shared_ptr<pit::Entry>& pitEntry)
128 {
129  this->processNack(nack, ingress.face, pitEntry);
130 }
131 
132 } // namespace fw
133 } // namespace nfd
static const time::milliseconds RETX_SUPPRESSION_MAX
static ParsedInstanceName parseInstanceName(const Name &input)
Parse a strategy instance name.
Definition: strategy.cpp:123
#define NFD_LOG_INIT(name)
Definition: logger.hpp:31
std::string to_string(const T &val)
Definition: backports.hpp:86
NackHeader & setReason(NackReason reason)
set reason code
Represents a face-endpoint pair in the forwarder.
represents a FIB entry
Definition: fib-entry.hpp:53
PartialName parameters
parameter components
Definition: strategy.hpp:390
static time_point now() noexcept
Definition: time.cpp:80
fib::NextHopList::const_iterator findEligibleNextHopWithEarliestOutRecord(const Face &inFace, const Interest &interest, const fib::NextHopList &nexthops, const shared_ptr< pit::Entry > &pitEntry)
pick an eligible NextHop with earliest out-record
Definition: algorithm.cpp:109
Main class of NFD&#39;s forwarding engine.
Definition: forwarder.hpp:53
Interest is retransmission and should be suppressed.
void setInstanceName(const Name &name)
Set strategy instance name.
Definition: strategy.hpp:417
Represents an Interest packet.
Definition: interest.hpp:48
BestRouteStrategy(Forwarder &forwarder, const Name &name=getStrategyName())
Represents a collection of nexthops.
Definition: fib-entry.hpp:39
NFD_VIRTUAL_WITH_TESTS void rejectPendingInterest(const shared_ptr< pit::Entry > &pitEntry)
Schedule the PIT entry for immediate deletion.
Definition: strategy.hpp:319
represents a Network Nack
Definition: nack.hpp:38
#define NDN_THROW(e)
Definition: exception.hpp:61
static const Name & getStrategyName()
ndn Face
Definition: face-impl.hpp:42
void afterReceiveInterest(const Interest &interest, const FaceEndpoint &ingress, const shared_ptr< pit::Entry > &pitEntry) override
Trigger after an Interest is received.
void processNack(const lp::Nack &nack, const Face &inFace, const shared_ptr< pit::Entry > &pitEntry)
Copyright (c) 2011-2015 Regents of the University of California.
Definition: ndn-common.hpp:39
Interest is new (not a retransmission)
#define NFD_LOG_DEBUG
Definition: logger.hpp:38
RetxSuppressionExponential m_retxSuppression
NFD_REGISTER_STRATEGY(AccessStrategy)
Represents an absolute name.
Definition: name.hpp:41
NFD_VIRTUAL_WITH_TESTS bool sendNack(const lp::NackHeader &header, Face &egress, const shared_ptr< pit::Entry > &pitEntry)
Send a Nack packet.
Definition: strategy.hpp:335
Represents a forwarding strategy.
Definition: strategy.hpp:38
optional< uint64_t > version
whether strategyName contains a version component
Definition: strategy.hpp:389
This file contains common algorithms used by forwarding strategies.
void afterReceiveNack(const lp::Nack &nack, const FaceEndpoint &ingress, const shared_ptr< pit::Entry > &pitEntry) override
Trigger after a Nack is received.
const fib::Entry & lookupFib(const pit::Entry &pitEntry) const
Performs a FIB lookup, considering Link object if present.
Definition: strategy.cpp:331
bool isNextHopEligible(const Face &inFace, const Interest &interest, const fib::NextHop &nexthop, const shared_ptr< pit::Entry > &pitEntry, bool wantUnused, time::steady_clock::time_point now)
Definition: algorithm.cpp:131
static Name makeInstanceName(const Name &input, const Name &strategyName)
Construct a strategy instance name.
Definition: strategy.cpp:134
const NextHopList & getNextHops() const
Definition: fib-entry.hpp:66
NFD_VIRTUAL_WITH_TESTS pit::OutRecord * sendInterest(const Interest &interest, Face &egress, const shared_ptr< pit::Entry > &pitEntry)
Send an Interest packet.
Definition: strategy.cpp:237
a retransmission suppression decision algorithm that suppresses retransmissions using exponential bac...
represents a Network NACK header
Definition: nack-header.hpp:57
RetxSuppressionResult decidePerPitEntry(pit::Entry &pitEntry)
determines whether Interest is a retransmission per pit entry and if so, whether it shall be forwarde...
boost::chrono::milliseconds milliseconds
Definition: time.hpp:48