fw: allow strategies to pick outgoing Interest

This commit changes outgoing Interest pipeline and Strategy API,
to give strategies an opportunity to pick an outgoing Interest that
matches the Interest table entry.
No strategy is updated in this commit.

refs #1756

Change-Id: Iffad77ef0078c437070039fca6b24a85df13bda7
diff --git a/daemon/fw/forwarder.cpp b/daemon/fw/forwarder.cpp
index b8bd076..9648e1b 100644
--- a/daemon/fw/forwarder.cpp
+++ b/daemon/fw/forwarder.cpp
@@ -26,7 +26,6 @@
 #include "forwarder.hpp"
 #include "pit-algorithm.hpp"
 #include "core/logger.hpp"
-#include "core/random.hpp"
 #include "strategy.hpp"
 #include "table/cleanup.hpp"
 #include <ndn-cxx/lp/tags.hpp>
@@ -206,8 +205,10 @@
     // chosen NextHop face exists?
     Face* nextHopFace = m_faceTable.get(*nextHopTag);
     if (nextHopFace != nullptr) {
+      NFD_LOG_DEBUG("onContentStoreMiss interest=" << interest.getName() << " nexthop-faceid=" << nextHopFace->getId());
       // go to outgoing Interest pipeline
-      this->onOutgoingInterest(pitEntry, *nextHopFace);
+      // scope control is unnecessary, because privileged app explicitly wants to forward
+      this->onOutgoingInterest(pitEntry, *nextHopFace, interest);
     }
     return;
   }
@@ -234,50 +235,16 @@
 }
 
 void
-Forwarder::onOutgoingInterest(const shared_ptr<pit::Entry>& pitEntry, Face& outFace,
-                              bool wantNewNonce)
+Forwarder::onOutgoingInterest(const shared_ptr<pit::Entry>& pitEntry, Face& outFace, const Interest& interest)
 {
-  if (outFace.getId() == face::INVALID_FACEID) {
-    NFD_LOG_WARN("onOutgoingInterest face=invalid interest=" << pitEntry->getName());
-    return;
-  }
   NFD_LOG_DEBUG("onOutgoingInterest face=" << outFace.getId() <<
                 " interest=" << pitEntry->getName());
 
-  // scope control
-  if (fw::violatesScope(*pitEntry, outFace)) {
-    NFD_LOG_DEBUG("onOutgoingInterest face=" << outFace.getId() <<
-                  " interest=" << pitEntry->getName() << " violates scope");
-    return;
-  }
-
-  // pick Interest
-  // The outgoing Interest picked is the last incoming Interest that does not come from outFace.
-  // If all in-records come from outFace, it's fine to pick that.
-  // This happens when there's only one in-record that comes from outFace.
-  // The legit use is for vehicular network; otherwise, strategy shouldn't send to the sole inFace.
-  pit::InRecordCollection::iterator pickedInRecord = std::max_element(
-    pitEntry->in_begin(), pitEntry->in_end(),
-    [&outFace] (const pit::InRecord& a, const pit::InRecord& b) {
-      bool isOutFaceA = &a.getFace() == &outFace;
-      bool isOutFaceB = &b.getFace() == &outFace;
-      return (isOutFaceA > isOutFaceB) ||
-             (isOutFaceA == isOutFaceB && a.getLastRenewed() < b.getLastRenewed());
-    });
-  BOOST_ASSERT(pickedInRecord != pitEntry->in_end());
-  auto interest = const_pointer_cast<Interest>(pickedInRecord->getInterest().shared_from_this());
-
-  if (wantNewNonce) {
-    interest = make_shared<Interest>(*interest);
-    static std::uniform_int_distribution<uint32_t> dist;
-    interest->setNonce(dist(getGlobalRng()));
-  }
-
   // insert out-record
-  pitEntry->insertOrUpdateOutRecord(outFace, *interest);
+  pitEntry->insertOrUpdateOutRecord(outFace, interest);
 
   // send Interest
-  outFace.sendInterest(*interest);
+  outFace.sendInterest(interest);
   ++m_counters.nOutInterests;
 }