From a1ad6046723a9b7bad4760f7fae8bb9139c678cb Mon Sep 17 00:00:00 2001
From: Ashlesh Gawande <agawande@memphis.edu>
Date: Mon, 7 Oct 2019 15:56:11 -0500
Subject: [PATCH] src: schedule sync interest on NoRoute NACK

refs #5012

Change-Id: I671b507c66e1957aae976c859e81591c93dc4d94
---
 src/logic.cpp | 14 +++++++++++++-
 src/logic.hpp | 12 ++++++++++++
 2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/src/logic.cpp b/src/logic.cpp
index 12b6feb..a8cd68e 100644
--- a/src/logic.cpp
+++ b/src/logic.cpp
@@ -368,6 +368,18 @@ Logic::onResetData(const Interest& interest, const Data& data)
   // This should not happened, drop the received data.
 }
 
+void
+Logic::onSyncNack(const Interest& interest, const ndn::lp::Nack& nack)
+{
+  _LOG_DEBUG_ID(">> Logic::onSyncNack");
+  if (nack.getReason() == ndn::lp::NackReason::NO_ROUTE) {
+    auto after = ndn::time::milliseconds(m_reexpressionJitter(m_rng));
+    _LOG_DEBUG_ID("Schedule sync interest after: " << after);
+    m_scheduler.schedule(after, [this] { sendSyncInterest(); });
+  }
+  _LOG_DEBUG_ID("<< Logic::onSyncNack");
+}
+
 void
 Logic::onSyncTimeout(const Interest& interest)
 {
@@ -627,7 +639,7 @@ Logic::sendSyncInterest()
 
   m_pendingSyncInterest = m_face.expressInterest(interest,
                                                  bind(&Logic::onSyncData, this, _1, _2),
-                                                 bind(&Logic::onSyncTimeout, this, _1), // Nack
+                                                 bind(&Logic::onSyncNack, this, _1, _2),
                                                  bind(&Logic::onSyncTimeout, this, _1));
 
   _LOG_DEBUG_ID("Send interest: " << interest.getName());
diff --git a/src/logic.hpp b/src/logic.hpp
index 408e164..b363e9d 100644
--- a/src/logic.hpp
+++ b/src/logic.hpp
@@ -291,6 +291,18 @@ private:
   void
   onResetData(const Interest& interest, const Data& data);
 
+  /**
+   * @brief Callback to handle Sync Interest Nack
+   *
+   * This method checks whether the Nack is of type NoRoute
+   * and schedules a sync interest in m_reexpressionJitter
+   *
+   * @param interest The sync interest for which the Nack happened
+   * @param nack The incoming Nack
+   */
+  void
+  onSyncNack(const Interest& interest, const ndn::lp::Nack& nack);
+
   /**
    * @brief Callback to handle Sync Interest timeout.
    *