Adding DataProducer class to produce and encrypt data packets.

Change-Id: I147164a1517f1f6f24536959bc572a6d777c15b0
refs: #3016
diff --git a/src/producer-db.cpp b/src/producer-db.cpp
new file mode 100644
index 0000000..c748953
--- /dev/null
+++ b/src/producer-db.cpp
@@ -0,0 +1,151 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2014-2015,  Regents of the University of California
+ *
+ * This file is part of ndn-group-encrypt (Group-based Encryption Protocol for NDN).
+ * See AUTHORS.md for complete list of ndn-group-encrypt authors and contributors.
+ *
+ * ndn-group-encrypt is free software: you can redistribute it and/or modify it under the terms
+ * of the GNU General Public License as published by the Free Software Foundation,
+ * either version 3 of the License, or (at your option) any later version.
+ *
+ * ndn-group-encrypt is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+ * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+ * PURPOSE.  See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * ndn-group-encrypt, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @author Prashanth Swaminathan <prashanthsw@gmail.com>
+ */
+
+#include "producer-db.hpp"
+
+#include <sqlite3.h>
+#include <boost/filesystem.hpp>
+#include <ndn-cxx/util/sqlite3-statement.hpp>
+#include <ndn-cxx/security/identity-certificate.hpp>
+
+namespace ndn {
+namespace gep {
+
+using util::Sqlite3Statement;
+using time::system_clock;
+
+static const std::string INITIALIZATION =
+  "CREATE TABLE IF NOT EXISTS                         \n"
+  "  contentkeys(                                     \n"
+  "    rowId            INTEGER PRIMARY KEY,          \n"
+  "    timeslot         INTEGER,                      \n"
+  "    key              BLOB NOT NULL                 \n"
+  "  );                                               \n"
+  "CREATE UNIQUE INDEX IF NOT EXISTS                  \n"
+  "   timeslotIndex ON contentkeys(timeslot);         \n";
+
+class ProducerDB::Impl
+{
+public:
+  Impl(const std::string& dbPath)
+  {
+    // open Database
+
+    int result = sqlite3_open_v2(dbPath.c_str(), &m_database,
+                                 SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE,
+#ifdef NDN_CXX_DISABLE_SQLITE3_FS_LOCKING
+                                 "unix-dotfile"
+#else
+                                 nullptr
+#endif
+                                 );
+
+    if (result != SQLITE_OK)
+      BOOST_THROW_EXCEPTION(Error("Producer DB cannot be opened/created: " + dbPath));
+
+    // enable foreign key
+    sqlite3_exec(m_database, "PRAGMA foreign_keys = ON", nullptr, nullptr, nullptr);
+
+    // initialize database specific tables
+    char* errorMessage = nullptr;
+    result = sqlite3_exec(m_database, INITIALIZATION.c_str(), nullptr, nullptr, &errorMessage);
+    if (result != SQLITE_OK && errorMessage != nullptr) {
+      sqlite3_free(errorMessage);
+      BOOST_THROW_EXCEPTION(Error("Producer DB cannot be initialized"));
+    }
+  }
+
+  ~Impl()
+  {
+    sqlite3_close(m_database);
+  }
+
+public:
+  sqlite3* m_database;
+};
+
+ProducerDB::ProducerDB(const std::string& dbPath)
+  : m_impl(new Impl(dbPath))
+{
+}
+
+ProducerDB::~ProducerDB() = default;
+
+static int32_t
+getFixedTimeslot(const system_clock::TimePoint& timeslot) {
+  return (time::toUnixTimestamp(timeslot)).count() / 3600000;
+}
+
+bool
+ProducerDB::hasContentKey(const system_clock::TimePoint& timeslot) const
+{
+  int32_t fixedTimeslot = getFixedTimeslot(timeslot);
+  Sqlite3Statement statement(m_impl->m_database,
+                             "SELECT key FROM contentkeys where timeslot=?");
+  statement.bind(1, fixedTimeslot);
+  return (statement.step() == SQLITE_ROW);
+}
+
+
+Buffer
+ProducerDB::getContentKey(const system_clock::TimePoint& timeslot) const
+{
+  int32_t fixedTimeslot = getFixedTimeslot(timeslot);
+  Sqlite3Statement statement(m_impl->m_database,
+                             "SELECT key FROM contentkeys where timeslot=?");
+  statement.bind(1, fixedTimeslot);
+
+  Buffer result;
+  if (statement.step() == SQLITE_ROW) {
+    result = Buffer(statement.getBlob(0), statement.getSize(0));
+  }
+  else {
+    BOOST_THROW_EXCEPTION(Error("Cannot get the key from database"));
+  }
+  return result;
+}
+
+void
+ProducerDB::addContentKey(const system_clock::TimePoint& timeslot, const Buffer& key)
+{
+  // BOOST_ASSERT(key.length() != 0);
+  int32_t fixedTimeslot = getFixedTimeslot(timeslot);
+  Sqlite3Statement statement(m_impl->m_database,
+                             "INSERT INTO contentkeys (timeslot, key)\
+                              values (?, ?)");
+  statement.bind(1, fixedTimeslot);
+  statement.bind(2, key.buf(), key.size(), SQLITE_TRANSIENT);
+  if (statement.step() != SQLITE_DONE)
+    BOOST_THROW_EXCEPTION(Error("Cannot add the key to database"));
+}
+
+void
+ProducerDB::deleteContentKey(const system_clock::TimePoint& timeslot)
+{
+  int32_t fixedTimeslot = getFixedTimeslot(timeslot);
+  Sqlite3Statement statement(m_impl->m_database,
+                             "DELETE FROM contentkeys WHERE timeslot=?");
+  statement.bind(1, fixedTimeslot);
+  statement.step();
+}
+
+} // namespace gep
+} // namespace ndn
diff --git a/src/producer-db.hpp b/src/producer-db.hpp
new file mode 100644
index 0000000..4a10d3f
--- /dev/null
+++ b/src/producer-db.hpp
@@ -0,0 +1,89 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2014-2015,  Regents of the University of California
+ *
+ * This file is part of ndn-group-encrypt (Group-based Encryption Protocol for NDN).
+ * See AUTHORS.md for complete list of ndn-group-encrypt authors and contributors.
+ *
+ * ndn-group-encrypt is free software: you can redistribute it and/or modify it under the terms
+ * of the GNU General Public License as published by the Free Software Foundation,
+ * either version 3 of the License, or (at your option) any later version.
+ *
+ * ndn-group-encrypt is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+ * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+ * PURPOSE.  See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * ndn-group-encrypt, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @author Prashanth Swaminathan <prashanthsw@gmail.com>
+ */
+
+#ifndef NDN_GEP_PRODUCER_DB_HPP
+#define NDN_GEP_PRODUCER_DB_HPP
+
+#include "common.hpp"
+
+namespace ndn {
+namespace gep {
+
+/**
+ * @brief ProducerDB is a class to manage the database of data producer.
+ * It contains one table that maps timeslots (to the nearest hour) to the
+ * content key created for that timeslot.
+ */
+class ProducerDB
+{
+public:
+  class Error : public std::runtime_error
+  {
+  public:
+    explicit
+    Error(const std::string& what)
+      : std::runtime_error(what)
+    {
+    }
+  };
+
+public:
+  explicit
+  ProducerDB(const std::string& dbPath);
+
+  ~ProducerDB();
+
+public:
+  /**
+   * @brief Check if content key exists for the hour covering @p timeslot
+   */
+  bool
+  hasContentKey(const time::system_clock::TimePoint& timeslot) const;
+
+  /**
+   * @brief Get content key for the hour covering @p timeslot
+   * @throws Error if the key does not exist
+   */
+  Buffer
+  getContentKey(const time::system_clock::TimePoint& timeslot) const;
+
+  /**
+   * @brief Add @p key as the content key for the hour covering @p timeslot
+   * @throws Error if a key for the same hour already exists
+   */
+  void
+  addContentKey(const time::system_clock::TimePoint& timeslot, const Buffer& key);
+
+  /**
+   * @brief Delete content key for the hour covering @p timeslot
+   */
+  void
+  deleteContentKey(const time::system_clock::TimePoint& timeslot);
+
+private:
+  class Impl;
+  unique_ptr<Impl> m_impl;
+};
+
+} // namespace gep
+} // namespace ndn
+
+#endif // NDN_GEP_PRODUCER_DB_HPP
diff --git a/src/producer.cpp b/src/producer.cpp
new file mode 100644
index 0000000..f112fa6
--- /dev/null
+++ b/src/producer.cpp
@@ -0,0 +1,241 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2014-2015,  Regents of the University of California
+ *
+ * This file is part of ndn-group-encrypt (Group-based Encryption Protocol for NDN).
+ * See AUTHORS.md for complete list of ndn-group-encrypt authors and contributors.
+ *
+ * ndn-group-encrypt is free software: you can redistribute it and/or modify it under the terms
+ * of the GNU General Public License as published by the Free Software Foundation,
+ * either version 3 of the License, or (at your option) any later version.
+ *
+ * ndn-group-encrypt is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+ * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+ * PURPOSE.  See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * ndn-group-encrypt, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @author Prashanth Swaminathan <prashanthsw@gmail.com>
+ */
+
+#include "producer.hpp"
+#include "random-number-generator.hpp"
+#include "algo/encryptor.hpp"
+#include "algo/aes.hpp"
+
+namespace ndn {
+namespace gep {
+
+using time::system_clock;
+
+static const int startTs = -2;
+static const int endTs = -1;
+
+/**
+  @brief Method to round the provided @p timeslot to the nearest whole
+  hour, so that we can store content keys uniformly (by start of the hour).
+*/
+static const system_clock::TimePoint
+getRoundedTimeslot(const system_clock::TimePoint& timeslot) {
+  return time::fromUnixTimestamp(
+    (time::toUnixTimestamp(timeslot) / 3600000) * 3600000);
+}
+
+Producer::Producer(const Name& prefix, const Name& dataType,
+                   Face& face, const std::string& dbPath, uint8_t repeatAttempts)
+  : m_face(face),
+    m_db(dbPath),
+    m_maxRepeatAttempts(repeatAttempts)
+{
+  Name fixedPrefix = prefix;
+  Name fixedDataType = dataType;
+  KeyInfo keyInfo;
+  /**
+    Fill m_ekeyInfo vector with all permutations of dataType, including the 'E-KEY'
+    component of the name. This will be used in DataProducer::createContentKey to
+    send interests without reconstructing names every time.
+  */
+  fixedPrefix.append(NAME_COMPONENT_READ);
+  while (!fixedDataType.empty()) {
+    Name nodeName = fixedPrefix;
+    nodeName.append(fixedDataType);
+    nodeName.append(NAME_COMPONENT_E_KEY);
+
+    m_ekeyInfo[nodeName] = keyInfo;
+    fixedDataType = fixedDataType.getPrefix(-1);
+  }
+  fixedPrefix.append(dataType);
+  m_namespace = prefix;
+  m_namespace.append(NAME_COMPONENT_SAMPLE);
+  m_namespace.append(dataType);
+}
+
+Name
+Producer::createContentKey(const system_clock::TimePoint& timeslot,
+                           const ProducerEKeyCallback& callback)
+{
+  const system_clock::TimePoint hourSlot = getRoundedTimeslot(timeslot);
+
+  // Create content key name.
+  Name contentKeyName = m_namespace;
+  contentKeyName.append(NAME_COMPONENT_C_KEY);
+  contentKeyName.append(time::toIsoString(hourSlot));
+
+  Buffer contentKeyBits;
+  if (m_db.hasContentKey(timeslot)) {
+    contentKeyBits = m_db.getContentKey(timeslot);
+    return contentKeyName;
+  }
+
+  RandomNumberGenerator rng;
+  AesKeyParams aesParams(128);
+  contentKeyBits = algo::Aes::generateKey(rng, aesParams).getKeyBits();
+  m_db.addContentKey(timeslot, contentKeyBits);
+
+  uint64_t timeCount = toUnixTimestamp(timeslot).count();
+  m_keyRequests.insert({timeCount, KeyRequest(m_ekeyInfo.size())});
+  KeyRequest& keyRequest = m_keyRequests.at(timeCount);
+
+  Exclude timeRange;
+  timeRange.excludeAfter(name::Component(time::toIsoString(timeslot)));
+  // Send interests for all nodes in tree.
+  std::unordered_map<Name, KeyInfo>::iterator it;
+  for (it = m_ekeyInfo.begin(); it != m_ekeyInfo.end(); ++it) {
+    const KeyInfo& keyInfo = it->second;
+    keyRequest.repeatAttempts.insert({it->first, 0});
+    if (timeslot < keyInfo.beginTimeslot || timeslot >= keyInfo.endTimeslot) {
+      sendKeyInterest(it->first, timeslot, keyRequest, callback, timeRange);
+    }
+    else {
+      Name eKeyName(it->first);
+      eKeyName.append(time::toIsoString(keyInfo.beginTimeslot));
+      eKeyName.append(time::toIsoString(keyInfo.endTimeslot));
+      encryptContentKey(keyRequest, keyInfo.keyBits, eKeyName, timeslot, callback);
+    }
+  }
+
+  return contentKeyName;
+}
+
+void
+Producer::produce(Data& data, const system_clock::TimePoint& timeslot,
+                  const uint8_t* content, size_t contentLen)
+{
+  Buffer contentKey;
+
+  Name contentKeyName = createContentKey(timeslot, nullptr);
+  contentKey = m_db.getContentKey(timeslot);
+
+  Name dataName = m_namespace;
+  dataName.append(time::toIsoString(getRoundedTimeslot(timeslot)));
+
+  data.setName(dataName);
+  algo::EncryptParams params(tlv::AlgorithmAesCbc, 16);
+  algo::encryptData(data, content, contentLen, contentKeyName,
+                    contentKey.buf(), contentKey.size(), params);
+  m_keychain.sign(data);
+}
+
+void
+Producer::sendKeyInterest(const Name& name, const system_clock::TimePoint& timeslot,
+                          KeyRequest& keyRequest,
+                          const ProducerEKeyCallback& callback,
+                          const Exclude& timeRange)
+{
+  auto onkey = std::bind(&Producer::handleCoveringKey, this, _1, _2,
+                         std::cref(timeslot), std::ref(keyRequest), callback);
+  auto timeout = std::bind(&Producer::handleTimeout, this, _1,
+                           std::cref(timeslot), std::ref(keyRequest), callback);
+
+  Selectors selector;
+  selector.setExclude(timeRange);
+  selector.setChildSelector(1);
+
+  Interest keyInterest(name);
+  keyInterest.setSelectors(selector);
+
+  m_face.expressInterest(keyInterest, onkey, timeout);
+}
+
+void
+Producer::encryptContentKey(KeyRequest& keyRequest, const Buffer& encryptionKey,
+                            const Name& eKeyName,
+                            const system_clock::TimePoint& timeslot,
+                            const ProducerEKeyCallback& callback)
+{
+  Name keyName = m_namespace;
+  keyName.append(NAME_COMPONENT_C_KEY);
+  keyName.append(time::toIsoString(getRoundedTimeslot(timeslot)));
+
+  Buffer contentKey = m_db.getContentKey(timeslot);
+
+  Data cKeyData;
+  cKeyData.setName(keyName);
+  algo::EncryptParams params(tlv::AlgorithmRsaOaep);
+  algo::encryptData(cKeyData, contentKey.buf(), contentKey.size(), eKeyName,
+                    encryptionKey.buf(), encryptionKey.size(), params);
+  m_keychain.sign(cKeyData);
+  keyRequest.encryptedKeys.push_back(cKeyData);
+
+  keyRequest.interestCount--;
+  if (keyRequest.interestCount == 0 && callback) {
+    callback(keyRequest.encryptedKeys);
+    m_keyRequests.erase(toUnixTimestamp(timeslot).count());
+  }
+}
+
+void
+Producer::handleCoveringKey(const Interest& interest, Data& data,
+                            const system_clock::TimePoint& timeslot,
+                            KeyRequest& keyRequest,
+                            const ProducerEKeyCallback& callback)
+{
+  Name interestName = interest.getName();
+  Name keyName = data.getName();
+
+  system_clock::TimePoint begin = time::fromIsoString(keyName.get(startTs).toUri());
+  system_clock::TimePoint end = time::fromIsoString(keyName.get(endTs).toUri());
+
+  if (timeslot >= end) {
+    Exclude timeRange = interest.getSelectors().getExclude();
+    timeRange.excludeBefore(keyName.get(startTs));
+    keyRequest.repeatAttempts[interestName] = 0;
+    sendKeyInterest(interestName, timeslot, keyRequest, callback, timeRange);
+    return;
+  }
+
+  const Block keyBlock = data.getContent();
+  Buffer encryptionKey(keyBlock.value(), keyBlock.value_size());
+  m_ekeyInfo[interestName].beginTimeslot = begin;
+  m_ekeyInfo[interestName].endTimeslot = end;
+  m_ekeyInfo[interestName].keyBits = encryptionKey;
+
+  encryptContentKey(keyRequest, encryptionKey, keyName, timeslot, callback);
+}
+
+void
+Producer::handleTimeout(const Interest& interest,
+                        const system_clock::TimePoint& timeslot,
+                        KeyRequest& keyRequest,
+                        const ProducerEKeyCallback& callback)
+{
+  Name interestName = interest.getName();
+
+  if (keyRequest.repeatAttempts[interestName] < m_maxRepeatAttempts) {
+    keyRequest.repeatAttempts[interestName]++;
+    sendKeyInterest(interestName, timeslot, keyRequest, callback,
+                    interest.getSelectors().getExclude());
+  }
+  else {
+    keyRequest.interestCount--;
+  }
+
+  if (keyRequest.interestCount == 0 && callback) {
+    callback(keyRequest.encryptedKeys);
+    m_keyRequests.erase(toUnixTimestamp(timeslot).count());
+  }
+}
+
+} // namespace gep
+} // namespace ndn
\ No newline at end of file
diff --git a/src/producer.hpp b/src/producer.hpp
new file mode 100644
index 0000000..c3cd14e
--- /dev/null
+++ b/src/producer.hpp
@@ -0,0 +1,150 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2014-2015,  Regents of the University of California
+ *
+ * This file is part of ndn-group-encrypt (Group-based Encryption Protocol for NDN).
+ * See AUTHORS.md for complete list of ndn-group-encrypt authors and contributors.
+ *
+ * ndn-group-encrypt is free software: you can redistribute it and/or modify it under the terms
+ * of the GNU General Public License as published by the Free Software Foundation,
+ * either version 3 of the License, or (at your option) any later version.
+ *
+ * ndn-group-encrypt is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+ * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+ * PURPOSE.  See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * ndn-group-encrypt, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @author Prashanth Swaminathan <prashanthsw@gmail.com>
+ */
+
+#ifndef NDN_GEP_PRODUCER_HPP
+#define NDN_GEP_PRODUCER_HPP
+
+#include "producer-db.hpp"
+
+#include <ndn-cxx/security/key-chain.hpp>
+#include <ndn-cxx/face.hpp>
+
+namespace ndn {
+namespace gep {
+
+// @brief Callback returns vector of Data contains content keys encrypted by E-KEYS
+typedef function<void(const std::vector<Data>&)> ProducerEKeyCallback;
+
+/**
+ * @brief Manage content key and data encryption
+ */
+class Producer
+{
+public:
+  struct KeyInfo {
+    time::system_clock::TimePoint beginTimeslot;
+    time::system_clock::TimePoint endTimeslot;
+    Buffer keyBits;
+  };
+
+  struct KeyRequest {
+    KeyRequest(size_t interests)
+    : interestCount(interests)
+    {}
+    size_t interestCount;
+    std::unordered_map<Name, size_t> repeatAttempts;
+    std::vector<Data> encryptedKeys;
+  };
+
+public:
+  /**
+   * @brief Construct a producer
+   *
+   * A producer can produce data with a naming convention:
+   *   /<@p prefix>/SAMPLES/<@p dataType>/[timestamp]
+   *
+   * The produced data packet is encrypted with a content key,
+   * which is stored in a database at @p dbPath.
+   *
+   * A producer also need to produce data containing content key
+   * encrypted with E-KEYs. A producer can retrieve E-KEYs through
+   * @p face, and will re-try for at most @p repeatAttemps times when
+   * E-KEY retrieval fails.
+   */
+  Producer(const Name& prefix, const Name& dataType,
+           Face& face, const std::string& dbPath, uint8_t repeatAttempts = 3);
+
+  /**
+   * @brief Create content key
+   *
+   * This method will first check if the content key exists. For existing
+   * content key, the method will return content key name directly.
+   * If the key does not exist, the method will create one and encrypt
+   * it using corresponding E-KEY. The encrypted content keys will be
+   * passed back through @p callback.
+   */
+  Name
+  createContentKey(const time::system_clock::TimePoint& timeslot,
+                   const ProducerEKeyCallback& callback);
+
+  /**
+   * @brief Produce an data packet encrypted using corresponding content key
+   *
+   * This method encrypts @p content with a content key covering
+   * @p timeslot, and set @p data with the encrypted content and
+   * appropriate data name.
+   */
+  void
+  produce(Data& data, const time::system_clock::TimePoint& timeslot,
+          const uint8_t* content, size_t contentLen);
+
+private:
+
+  /**
+   * @brief Sends interest through face with necessary callbacks
+   *        Uses @p exclude to limit interest if specified
+   */
+  void
+  sendKeyInterest(const Name& name, const time::system_clock::TimePoint& timeslot,
+                  KeyRequest& keyRequest, const ProducerEKeyCallback& callback,
+                  const Exclude& timeRange = Exclude());
+
+  /**
+   * @brief Updates state in @p keyRequest on timeout
+   */
+  void
+  handleTimeout(const Interest& interest,
+                const time::system_clock::TimePoint& timeslot,
+                KeyRequest& keyRequest, const ProducerEKeyCallback& callback);
+
+  /**
+   * @brief Checks that encryption key contained in @p data fits @p timeslot
+   *        Sends refined interest if required
+   */
+  void
+  handleCoveringKey(const Interest& interest, Data& data,
+                    const time::system_clock::TimePoint& timeslot,
+                    KeyRequest& keyRequest, const ProducerEKeyCallback& callback);
+
+  /**
+   * @brief Encrypts content key for @p timeslot with @p encryptionKey
+   *        Fires @p callback if no more interests to process
+   */
+  void
+  encryptContentKey(KeyRequest& keyRequest, const Buffer& encryptionKey,
+                    const Name& eKeyName,
+                    const time::system_clock::TimePoint& timeslot,
+                    const ProducerEKeyCallback& callback);
+
+private:
+  Face& m_face;
+  Name m_namespace;
+  KeyChain m_keychain;
+  std::unordered_map<Name, KeyInfo> m_ekeyInfo;
+  std::unordered_map<uint64_t, KeyRequest> m_keyRequests;
+  ProducerDB m_db;
+  uint8_t m_maxRepeatAttempts;
+};
+
+} // namespace gep
+} // namespace ndn
+
+#endif // NDN_GEP_PRODUCER_HPP