[HICN-252] Add per-application policy framework to hicn-light forwarder

Change-Id: I0531cd7a7de179581295ae34766c81cd9cf3e172
Signed-off-by: Jordan Augé <jordan.auge+fdio@cisco.com>
Signed-off-by: Mauro Sardara <msardara@cisco.com>
Co-authored-by: Mauro Sardara <msardara@cisco.com>

10 files changed, 256 insertions, 15 deletions

diff --git a/hicn-light/src/hicn/strategies/loadBalancer.c b/hicn-light/src/hicn/strategies/loadBalancer.c
index 6ab26b7ca..b66de217e 100644
--- a/hicn-light/src/hicn/strategies/loadBalancer.c
+++ b/hicn-light/src/hicn/strategies/loadBalancer.c
@@ -36,9 +36,15 @@ static void _strategyLoadBalancer_ReceiveObject(StrategyImpl *strategy,
 static void _strategyLoadBalancer_OnTimeout(StrategyImpl *strategy,
                                             const NumberSet *egressId);
 static NumberSet *_strategyLoadBalancer_LookupNexthop(
-    StrategyImpl *strategy, const Message *interestMessage);
+    StrategyImpl *strategy,
+#ifdef WITH_POLICY
+    NumberSet * nexthops,
+#endif /* WITH_POLICY */
+    const Message *interestMessage);
+#ifndef WITH_POLICY
 static NumberSet *_strategyLoadBalancer_ReturnNexthops(StrategyImpl *strategy);
 static unsigned _strategyLoadBalancer_CountNexthops(StrategyImpl *strategy);
+#endif /* ! WITH_POLICY */
 static void _strategyLoadBalancer_AddNexthop(StrategyImpl *strategy,
                                              unsigned connectionId);
 static void _strategyLoadBalancer_RemoveNexthop(StrategyImpl *strategy,
@@ -51,8 +57,10 @@ static StrategyImpl _template = {
     .receiveObject = &_strategyLoadBalancer_ReceiveObject,
     .onTimeout = &_strategyLoadBalancer_OnTimeout,
     .lookupNexthop = &_strategyLoadBalancer_LookupNexthop,
+#ifndef WITH_POLICY
     .returnNexthops = &_strategyLoadBalancer_ReturnNexthops,
     .countNexthops = &_strategyLoadBalancer_CountNexthops,
+#endif /* ! WITH_POLICY */
     .addNexthop = &_strategyLoadBalancer_AddNexthop,
     .removeNexthop = &_strategyLoadBalancer_RemoveNexthop,
     .destroy = &_strategyLoadBalancer_ImplDestroy,
@@ -63,10 +71,14 @@ struct strategy_load_balancer;
 typedef struct strategy_load_balancer StrategyLoadBalancer;
 
 struct strategy_load_balancer {
+#ifndef WITH_POLICY
   double weights_sum;
+#endif /* ! WITH_POLICY */
   // hash map from connectionId to StrategyNexthopState
   PARCHashMap *strategy_state;
+#ifndef WITH_POLICY
   NumberSet *nexthops;
+#endif /* ! WITH_POLICY */
 };
 
 StrategyImpl *strategyLoadBalancer_Create() {
@@ -75,9 +87,13 @@ StrategyImpl *strategyLoadBalancer_Create() {
   parcAssertNotNull(strategy, "parcMemory_AllocateAndClear(%zu) returned NULL",
                     sizeof(StrategyLoadBalancer));
 
+#ifndef WITH_POLICY
   strategy->weights_sum = 0.0;
+#endif /* ! WITH_POLICY */
   strategy->strategy_state = parcHashMap_Create();
+#ifndef WITH_POLICY
   strategy->nexthops = numberSet_Create();
+#endif /* ! WITH_POLICY */
   srand((unsigned int)time(NULL));
 
   StrategyImpl *impl = parcMemory_AllocateAndClear(sizeof(StrategyImpl));
@@ -99,12 +115,17 @@ strategy_type _strategyLoadBalancer_GetStrategy(StrategyImpl *strategy) {
 static void _update_Stats(StrategyLoadBalancer *strategy,
                           StrategyNexthopState *state, bool inc) {
   const double ALPHA = 0.9;
+#ifdef WITH_POLICY
+  strategyNexthopState_UpdateState(state, inc, ALPHA);
+#else
   double w = strategyNexthopState_GetWeight(state);
   strategy->weights_sum -= w;
   w = strategyNexthopState_UpdateState(state, inc, ALPHA);
   strategy->weights_sum += w;
+#endif /* WITH_POLICY */
 }
 
+#ifndef WITH_POLICY
 static unsigned _select_Nexthop(StrategyLoadBalancer *strategy) {
   double rnd = (double)rand() / (double)RAND_MAX;
   double start_range = 0.0;
@@ -135,6 +156,7 @@ static unsigned _select_Nexthop(StrategyLoadBalancer *strategy) {
   // this!
   return nexthop;
 }
+#endif /* ! WITH_POLICY */
 
 static void _strategyLoadBalancer_ReceiveObject(StrategyImpl *strategy,
                                                 const NumberSet *egressId,
@@ -164,14 +186,47 @@ static void _strategyLoadBalancer_OnTimeout(StrategyImpl *strategy,
 }
 
 static NumberSet *_strategyLoadBalancer_LookupNexthop(
-    StrategyImpl *strategy, const Message *interestMessage) {
+    StrategyImpl *strategy,
+#ifdef WITH_POLICY
+    NumberSet * nexthops,
+#endif /* WITH_POLICY */
+    const Message *interestMessage) {
   StrategyLoadBalancer *lb = (StrategyLoadBalancer *)strategy->context;
+  NumberSet *outList = numberSet_Create();
 
+#ifdef WITH_POLICY
+  /* Compute the sum of weights of potential next hops */
+  double sum = 0;
+  for (unsigned i = 0; i < numberSet_Length(nexthops); i++) {
+    PARCUnsigned *cid = parcUnsigned_Create(numberSet_GetItem(nexthops, i));
+    const StrategyNexthopState *elem =
+        parcHashMap_Get(lb->strategy_state, cid);
+    if (!elem)
+      continue;
+    sum += strategyNexthopState_GetWeight(elem);
+  }
+
+  /* Perform weighted random selection */
+  double distance = (double)rand() * sum / ((double)RAND_MAX + 1);
+
+  for (unsigned i = 0; i < numberSet_Length(nexthops); i++) {
+    PARCUnsigned *cid = parcUnsigned_Create(numberSet_GetItem(nexthops, i));
+    const StrategyNexthopState *state =
+        parcHashMap_Get(lb->strategy_state, cid);
+    if (!state)
+      continue;
+    distance -= strategyNexthopState_GetWeight(state);
+    if (distance < 0) {
+      numberSet_Add(outList, parcUnsigned_GetUnsigned(cid));
+      _update_Stats(lb, (StrategyNexthopState *)state, true);
+      break;
+    }
+  }
+#else
   unsigned in_connection = message_GetIngressConnectionId(interestMessage);
   PARCUnsigned *in = parcUnsigned_Create(in_connection);
 
   unsigned mapSize = (unsigned)parcHashMap_Size(lb->strategy_state);
-  NumberSet *outList = numberSet_Create();
 
   if ((mapSize == 0) ||
       ((mapSize == 1) && parcHashMap_Contains(lb->strategy_state, in))) {
@@ -201,9 +256,12 @@ static NumberSet *_strategyLoadBalancer_LookupNexthop(
   parcUnsigned_Release(&out);
 
   numberSet_Add(outList, out_connection);
+#endif /* WITH_POLICY */
+
   return outList;
 }
 
+#ifndef WITH_POLICY
 static NumberSet *_strategyLoadBalancer_ReturnNexthops(StrategyImpl *strategy) {
   StrategyLoadBalancer *lb = (StrategyLoadBalancer *)strategy->context;
   return lb->nexthops;
@@ -213,10 +271,13 @@ unsigned _strategyLoadBalancer_CountNexthops(StrategyImpl *strategy) {
   StrategyLoadBalancer *lb = (StrategyLoadBalancer *)strategy->context;
   return (unsigned)numberSet_Length(lb->nexthops);
 }
+#endif /* ! WITH_POLICY */
 
 static void _strategyLoadBalancer_resetState(StrategyImpl *strategy) {
   StrategyLoadBalancer *lb = (StrategyLoadBalancer *)strategy->context;
+#ifndef WITH_POLICY
   lb->weights_sum = 0.0;
+#endif/* ! WITH_POLICY */
   PARCIterator *it = parcHashMap_CreateKeyIterator(lb->strategy_state);
 
   while (parcIterator_HasNext(it)) {
@@ -225,7 +286,9 @@ static void _strategyLoadBalancer_resetState(StrategyImpl *strategy) {
         (StrategyNexthopState *)parcHashMap_Get(lb->strategy_state, cid);
 
     strategyNexthopState_Reset(elem);
+#ifndef WITH_POLICY
     lb->weights_sum += strategyNexthopState_GetWeight(elem);
+#endif /* ! WITH_POLICY */
   }
 
   parcIterator_Release(&it);
@@ -241,7 +304,9 @@ static void _strategyLoadBalancer_AddNexthop(StrategyImpl *strategy,
 
   if (!parcHashMap_Contains(lb->strategy_state, cid)) {
     parcHashMap_Put(lb->strategy_state, cid, state);
+#ifndef WITH_POLICY
     numberSet_Add(lb->nexthops, connectionId);
+#endif /* WITH_POLICY */
     _strategyLoadBalancer_resetState(strategy);
   }
 }
@@ -254,7 +319,9 @@ static void _strategyLoadBalancer_RemoveNexthop(StrategyImpl *strategy,
 
   if (parcHashMap_Contains(lb->strategy_state, cid)) {
     parcHashMap_Remove(lb->strategy_state, cid);
+#ifndef WITH_POLICY
     numberSet_Remove(lb->nexthops, connectionId);
+#endif /* WITH_POLICY */
     _strategyLoadBalancer_resetState(strategy);
   }
 
@@ -270,7 +337,9 @@ static void _strategyLoadBalancer_ImplDestroy(StrategyImpl **strategyPtr) {
   StrategyLoadBalancer *strategy = (StrategyLoadBalancer *)impl->context;
 
   parcHashMap_Release(&(strategy->strategy_state));
+#ifndef WITH_POLICY
   numberSet_Release(&(strategy->nexthops));
+#endif /* ! WITH_POLICY */
 
   parcMemory_Deallocate((void **)&strategy);
   parcMemory_Deallocate((void **)&impl);
diff --git a/hicn-light/src/hicn/strategies/loadBalancer.h b/hicn-light/src/hicn/strategies/loadBalancer.h
index d0f4faece..74920768d 100644
--- a/hicn-light/src/hicn/strategies/loadBalancer.h
+++ b/hicn-light/src/hicn/strategies/loadBalancer.h
@@ -23,4 +23,5 @@
 #include <hicn/strategies/strategyImpl.h>
 
 StrategyImpl *strategyLoadBalancer_Create();
+
 #endif  // loadBalancer_h
diff --git a/hicn-light/src/hicn/strategies/loadBalancerWithPD.c b/hicn-light/src/hicn/strategies/loadBalancerWithPD.c
index 58f3b25fc..b0aae4cbb 100644
--- a/hicn-light/src/hicn/strategies/loadBalancerWithPD.c
+++ b/hicn-light/src/hicn/strategies/loadBalancerWithPD.c
@@ -38,11 +38,17 @@ static void _strategyLoadBalancerWithPD_ReceiveObject(
 static void _strategyLoadBalancerWithPD_OnTimeout(StrategyImpl *strategy,
                                                   const NumberSet *egressId);
 static NumberSet *_strategyLoadBalancerWithPD_LookupNexthop(
-    StrategyImpl *strategy, const Message *interestMessage);
+    StrategyImpl *strategy,
+#ifdef WITH_POLICY
+    NumberSet * nexthops,
+#endif
+    const Message *interestMessage);
+#ifndef WITH_POLICY
 static NumberSet *_strategyLoadBalancerWithPD_ReturnNexthops(
     StrategyImpl *strategy);
 static unsigned _strategyLoadBalancerWithPD_CountNexthops(
     StrategyImpl *strategy);
+#endif /* ! WITH_POLICY */
 static void _strategyLoadBalancerWithPD_AddNexthop(StrategyImpl *strategy,
                                                    unsigned connectionId);
 static void _strategyLoadBalancerWithPD_RemoveNexthop(StrategyImpl *strategy,
@@ -56,8 +62,10 @@ static StrategyImpl _template = {
     .receiveObject = &_strategyLoadBalancerWithPD_ReceiveObject,
     .onTimeout = &_strategyLoadBalancerWithPD_OnTimeout,
     .lookupNexthop = &_strategyLoadBalancerWithPD_LookupNexthop,
+#ifndef WITH_POLICY
     .returnNexthops = &_strategyLoadBalancerWithPD_ReturnNexthops,
     .countNexthops = &_strategyLoadBalancerWithPD_CountNexthops,
+#endif /* ! WITH_POLICY */
     .addNexthop = &_strategyLoadBalancerWithPD_AddNexthop,
     .removeNexthop = &_strategyLoadBalancerWithPD_RemoveNexthop,
     .destroy = &_strategyLoadBalancerWithPD_ImplDestroy,
@@ -72,13 +80,19 @@ struct strategy_load_balancer_with_pd {
   unsigned min_delay;
   // hash map from connectionId to StrategyNexthopState
   PARCHashMap *strategy_state;
+#ifndef WITH_POLICY
   NumberSet *nexthops;
-  ConnectionTable *connTable;
+#endif /* ! WITH_POLICY */
+  const ConnectionTable *connTable;
   bool toInit;
   unsigned int fwdPackets;
 };
 
+#ifdef WITH_POLICY
+StrategyImpl *strategyLoadBalancerWithPD_Create(const ConnectionTable *table) {
+#else
 StrategyImpl *strategyLoadBalancerWithPD_Create() {
+#endif /* WITH_POLICY */
   StrategyLoadBalancerWithPD *strategy =
       parcMemory_AllocateAndClear(sizeof(StrategyLoadBalancerWithPD));
   parcAssertNotNull(strategy, "parcMemory_AllocateAndClear(%zu) returned NULL",
@@ -87,7 +101,9 @@ StrategyImpl *strategyLoadBalancerWithPD_Create() {
   strategy->weights_sum = 0.0;
   strategy->min_delay = INT_MAX;
   strategy->strategy_state = parcHashMap_Create();
+#ifndef WITH_POLICY
   strategy->nexthops = numberSet_Create();
+#endif /* ! WITH_POLICY */
   srand((unsigned int)time(NULL));
 
   StrategyImpl *impl = parcMemory_AllocateAndClear(sizeof(StrategyImpl));
@@ -127,6 +143,31 @@ static void _update_Stats(StrategyLoadBalancerWithPD *strategy,
   strategy->weights_sum += w;
 }
 
+#ifdef WITH_POLICY
+static void _sendProbes(StrategyLoadBalancerWithPD *strategy, NumberSet * nexthops) {
+  unsigned size = (unsigned)numberSet_Length(nexthops);
+  for (unsigned i = 0; i < size; i++) {
+    unsigned nhop = numberSet_GetItem(nexthops, i);
+    Connection *conn =
+        (Connection *)connectionTable_FindById(strategy->connTable, nhop);
+    if (!conn)
+        continue;
+
+    connection_Probe(conn);
+    unsigned delay = (unsigned)connection_GetDelay(conn);
+    PARCUnsigned *cid = parcUnsigned_Create(nhop);
+    StrategyNexthopStateWithPD *elem =
+        (StrategyNexthopStateWithPD *)parcHashMap_Get(
+            strategy->strategy_state, cid);
+    strategyNexthopStateWithPD_SetDelay(elem, delay);
+    if (delay < strategy->min_delay && delay != 0) {
+      strategy->min_delay = delay;
+    }
+
+    parcUnsigned_Release(&cid);
+  }
+}
+#else
 static void _sendProbes(StrategyLoadBalancerWithPD *strategy) {
   unsigned size = (unsigned)numberSet_Length(strategy->nexthops);
   for (unsigned i = 0; i < size; i++) {
@@ -149,7 +190,53 @@ static void _sendProbes(StrategyLoadBalancerWithPD *strategy) {
     }
   }
 }
+#endif /* WITH_POLICY */
+
+#ifdef WITH_POLICY
+static unsigned _select_Nexthop(StrategyLoadBalancerWithPD *strategy, NumberSet * nexthops) {
+  strategy->fwdPackets++;
+  if (strategy->toInit || strategy->fwdPackets == PROBE_FREQUENCY) {
+    strategy->toInit = false;
+    strategy->fwdPackets = 0;
+    _sendProbes(strategy, nexthops);
+  }
+  double rnd = (double)rand() / (double)RAND_MAX;
+  double start_range = 0.0;
+
+  PARCIterator *it = parcHashMap_CreateKeyIterator(strategy->strategy_state);
+
+  unsigned nexthop = 100000;
+  while (parcIterator_HasNext(it)) {
+    PARCUnsigned *cid = parcIterator_Next(it);
+    const StrategyNexthopStateWithPD *elem =
+        parcHashMap_Get(strategy->strategy_state, cid);
 
+    double w = strategyNexthopStateWithPD_GetWeight(elem);
+
+    // printf("next = %u .. pi %u avgpi %f w %f avgrtt
+    // %f\n",parcUnsigned_GetUnsigned(cid),
+    // strategyNexthopStateWithPD_GetPI(elem),
+    //        strategyNexthopStateWithPD_GetWeight(elem),
+    //        strategyNexthopStateWithPD_GetWeight(elem),
+    //        strategyNexthopStateWithPD_GetAvgRTT(elem));
+
+    double prob = w / strategy->weights_sum;
+    if ((rnd >= start_range) && (rnd < (start_range + prob))) {
+      nexthop = parcUnsigned_GetUnsigned(cid);
+      break;
+    } else {
+      start_range += prob;
+    }
+  }
+
+  parcIterator_Release(&it);
+
+  // if no face is selected by the algorithm (for example because of a wrong
+  // round in the weights) we may always select the last face here. Double check
+  // this!
+  return nexthop;
+}
+#else
 static unsigned _select_Nexthop(StrategyLoadBalancerWithPD *strategy) {
   strategy->fwdPackets++;
   if (strategy->toInit || strategy->fwdPackets == PROBE_FREQUENCY) {
@@ -193,6 +280,7 @@ static unsigned _select_Nexthop(StrategyLoadBalancerWithPD *strategy) {
   // this!
   return nexthop;
 }
+#endif /* WITH_POLICY */
 
 static void _strategyLoadBalancerWithPD_ReceiveObject(
     StrategyImpl *strategy, const NumberSet *egressId,
@@ -242,7 +330,11 @@ static void _strategyLoadBalancerWithPD_OnTimeout(StrategyImpl *strategy,
 // function never returns NULL. in case we have no output face we need to return
 // an empty NumberSet
 static NumberSet *_strategyLoadBalancerWithPD_LookupNexthop(
-    StrategyImpl *strategy, const Message *interestMessage) {
+    StrategyImpl *strategy,
+#ifdef WITH_POLICY
+    NumberSet * nexthops,
+#endif
+    const Message *interestMessage) {
   StrategyLoadBalancerWithPD *lb =
       (StrategyLoadBalancerWithPD *)strategy->context;
 
@@ -262,7 +354,11 @@ static NumberSet *_strategyLoadBalancerWithPD_LookupNexthop(
 
   unsigned out_connection;
   do {
+#ifdef WITH_POLICY
+    out_connection = _select_Nexthop(lb, nexthops);
+#else
     out_connection = _select_Nexthop(lb);
+#endif /* WITH_POLICY */
   } while (out_connection == in_connection);
 
   PARCUnsigned *out = parcUnsigned_Create(out_connection);
@@ -284,6 +380,7 @@ static NumberSet *_strategyLoadBalancerWithPD_LookupNexthop(
   return outList;
 }
 
+#ifndef WITH_POLICY
 static NumberSet *_strategyLoadBalancerWithPD_ReturnNexthops(
     StrategyImpl *strategy) {
   StrategyLoadBalancerWithPD *lb =
@@ -296,6 +393,7 @@ unsigned _strategyLoadBalancerWithPD_CountNexthops(StrategyImpl *strategy) {
       (StrategyLoadBalancerWithPD *)strategy->context;
   return (unsigned)numberSet_Length(lb->nexthops);
 }
+#endif /* WITH_POLICY */
 
 static void _strategyLoadBalancerWithPD_resetState(StrategyImpl *strategy) {
   StrategyLoadBalancerWithPD *lb =
@@ -328,7 +426,9 @@ static void _strategyLoadBalancerWithPD_AddNexthop(StrategyImpl *strategy,
 
   if (!parcHashMap_Contains(lb->strategy_state, cid)) {
     parcHashMap_Put(lb->strategy_state, cid, state);
+#ifndef WITH_POLICY
     numberSet_Add(lb->nexthops, connectionId);
+#endif /* ! WITH_POLICY */
     _strategyLoadBalancerWithPD_resetState(strategy);
   }
 }
@@ -342,7 +442,9 @@ static void _strategyLoadBalancerWithPD_RemoveNexthop(StrategyImpl *strategy,
 
   if (parcHashMap_Contains(lb->strategy_state, cid)) {
     parcHashMap_Remove(lb->strategy_state, cid);
+#ifndef WITH_POLICY
     numberSet_Remove(lb->nexthops, connectionId);
+#endif /* ! WITH_POLICY */
     _strategyLoadBalancerWithPD_resetState(strategy);
   }
 
@@ -360,7 +462,9 @@ static void _strategyLoadBalancerWithPD_ImplDestroy(
       (StrategyLoadBalancerWithPD *)impl->context;
 
   parcHashMap_Release(&(strategy->strategy_state));
+#ifndef WITH_POLICY
   numberSet_Release(&(strategy->nexthops));
+#endif /* ! WITH_POLICY */
 
   parcMemory_Deallocate((void **)&strategy);
   parcMemory_Deallocate((void **)&impl);
diff --git a/hicn-light/src/hicn/strategies/loadBalancerWithPD.h b/hicn-light/src/hicn/strategies/loadBalancerWithPD.h
index d8a215913..e6c9f8271 100644
--- a/hicn-light/src/hicn/strategies/loadBalancerWithPD.h
+++ b/hicn-light/src/hicn/strategies/loadBalancerWithPD.h
@@ -21,10 +21,15 @@
 #ifndef loadBalancerWithPD_h
 #define loadBalancerWithPD_h
 
-#include <hicn/core/connectionTable.h>
 #include <hicn/strategies/strategyImpl.h>
+#include <hicn/core/connectionTable.h>
 
+#ifdef WITH_POLICY
+StrategyImpl *strategyLoadBalancerWithPD_Create(const ConnectionTable * table);
+#else
 StrategyImpl *strategyLoadBalancerWithPD_Create();
+#endif /* WITH_POLICY */
+
 void strategyLoadBalancerWithPD_SetConnectionTable(StrategyImpl *strategy,
                                                    ConnectionTable *connTable);
 #endif  // loadBalancerWithPD_h
diff --git a/hicn-light/src/hicn/strategies/nexthopState.c b/hicn-light/src/hicn/strategies/nexthopState.c
index 0997193ce..40af14832 100644
--- a/hicn-light/src/hicn/strategies/nexthopState.c
+++ b/hicn-light/src/hicn/strategies/nexthopState.c
@@ -23,6 +23,8 @@
 #include <parc/assert/parc_Assert.h>
 #include <hicn/strategies/nexthopState.h>
 
+#define AVG_PI_THRESHOLD 1e-3
+
 struct strategy_nexthop_state {
   unsigned int pi;
   double avg_pi;
@@ -197,7 +199,11 @@ double strategyNexthopState_UpdateState(StrategyNexthopState *x, bool inc,
     }
   }
   x->avg_pi = (x->avg_pi * alpha) + (x->pi * (1 - alpha));
+#ifdef WITH_POLICY
+  if (x->avg_pi < AVG_PI_THRESHOLD) {
+#else
   if (x->avg_pi == 0.0) {
+#endif /* WITH_POLICY */
     x->avg_pi = 0.1;
   }
   x->weight = 1 / x->avg_pi;
diff --git a/hicn-light/src/hicn/strategies/rnd.c b/hicn-light/src/hicn/strategies/rnd.c
index e2d74036c..637fd90f9 100644
--- a/hicn-light/src/hicn/strategies/rnd.c
+++ b/hicn-light/src/hicn/strategies/rnd.c
@@ -32,9 +32,14 @@ static void _strategyRnd_ReceiveObject(StrategyImpl *strategy,
 static void _strategyRnd_OnTimeout(StrategyImpl *strategy,
                                    const NumberSet *egressId);
 static NumberSet *_strategyRnd_LookupNexthop(StrategyImpl *strategy,
-                                             const Message *interestMessage);
+#ifdef WITH_POLICY
+    NumberSet * nexthops,
+#endif /* WITH_POLICY */
+    const Message *interestMessage);
+#ifndef WITH_POLICY
 static NumberSet *_strategyRnd_ReturnNexthops(StrategyImpl *strategy);
 static unsigned _strategyRnd_CountNexthops(StrategyImpl *strategy);
+#endif /* ! WITH_POLICY */
 static void _strategyRnd_AddNexthop(StrategyImpl *strategy,
                                     unsigned connectionId);
 static void _strategyRnd_RemoveNexthop(StrategyImpl *strategy,
@@ -47,8 +52,10 @@ static StrategyImpl _template = {
     .receiveObject = &_strategyRnd_ReceiveObject,
     .onTimeout = &_strategyRnd_OnTimeout,
     .lookupNexthop = &_strategyRnd_LookupNexthop,
+#ifndef WITH_POLICY
     .returnNexthops = &_strategyRnd_ReturnNexthops,
     .countNexthops = &_strategyRnd_CountNexthops,
+#endif /* ! WITH_POLICY */
     .addNexthop = &_strategyRnd_AddNexthop,
     .removeNexthop = &_strategyRnd_RemoveNexthop,
     .destroy = &_strategyRnd_ImplDestroy,
@@ -59,7 +66,9 @@ struct strategy_rnd;
 typedef struct strategy_rnd StrategyRnd;
 
 struct strategy_rnd {
+#ifndef WITH_POLICY
   NumberSet *nexthops;
+#endif /* ! WITH_POLICY */
 };
 
 StrategyImpl *strategyRnd_Create() {
@@ -67,7 +76,9 @@ StrategyImpl *strategyRnd_Create() {
   parcAssertNotNull(strategy, "parcMemory_AllocateAndClear(%zu) returned NULL",
                     sizeof(StrategyRnd));
 
+#ifndef WITH_POLICY
   strategy->nexthops = numberSet_Create();
+#endif /* ! WITH_POLICY */
   srand((unsigned int)time(NULL));
 
   StrategyImpl *impl = parcMemory_AllocateAndClear(sizeof(StrategyImpl));
@@ -85,6 +96,7 @@ strategy_type _strategyRnd_GetStrategy(StrategyImpl *strategy) {
   return SET_STRATEGY_RANDOM;
 }
 
+#ifndef WITH_POLICY
 static int _select_Nexthop(StrategyRnd *strategy) {
   unsigned len = (unsigned)numberSet_Length(strategy->nexthops);
   if (len == 0) {
@@ -94,6 +106,7 @@ static int _select_Nexthop(StrategyRnd *strategy) {
   int rnd = (rand() % len);
   return numberSet_GetItem(strategy->nexthops, rnd);
 }
+#endif /* ! WITH_POLICY */
 
 static void _strategyRnd_ReceiveObject(StrategyImpl *strategy,
                                        const NumberSet *egressId,
@@ -104,13 +117,22 @@ static void _strategyRnd_OnTimeout(StrategyImpl *strategy,
                                    const NumberSet *egressId) {}
 
 static NumberSet *_strategyRnd_LookupNexthop(StrategyImpl *strategy,
-                                             const Message *interestMessage) {
-  StrategyRnd *srnd = (StrategyRnd *)strategy->context;
+#ifdef WITH_POLICY
+        NumberSet * nexthops,
+#endif /* WITH_POLICY */
+        const Message *interestMessage) {
+  unsigned out_connection;
+  NumberSet *out = numberSet_Create();
+
+#ifdef WITH_POLICY
+  // We return one next hop at random
+  out_connection = numberSet_GetItem(nexthops, rand() % numberSet_Length(nexthops));
 
+#else
+  StrategyRnd *srnd = (StrategyRnd *)strategy->context;
   unsigned in_connection = message_GetIngressConnectionId(interestMessage);
   unsigned nexthopSize = (unsigned)numberSet_Length(srnd->nexthops);
 
-  NumberSet *out = numberSet_Create();
   if ((nexthopSize == 0) ||
       ((nexthopSize == 1) &&
        numberSet_Contains(srnd->nexthops, in_connection))) {
@@ -119,7 +141,6 @@ static NumberSet *_strategyRnd_LookupNexthop(StrategyImpl *strategy,
     return out;
   }
 
-  unsigned out_connection;
   do {
     out_connection = _select_Nexthop(srnd);
   } while (out_connection == in_connection);
@@ -127,11 +148,13 @@ static NumberSet *_strategyRnd_LookupNexthop(StrategyImpl *strategy,
   if (out_connection == -1) {
     return out;
   }
+#endif /* WITH_POLICY */
 
   numberSet_Add(out, out_connection);
   return out;
 }
 
+#ifndef WITH_POLICY
 static NumberSet *_strategyRnd_ReturnNexthops(StrategyImpl *strategy) {
   StrategyRnd *srnd = (StrategyRnd *)strategy->context;
   return srnd->nexthops;
@@ -141,22 +164,27 @@ unsigned _strategyRnd_CountNexthops(StrategyImpl *strategy) {
   StrategyRnd *srnd = (StrategyRnd *)strategy->context;
   return (unsigned)numberSet_Length(srnd->nexthops);
 }
+#endif /* ! WITH_POLICY */
 
 static void _strategyRnd_AddNexthop(StrategyImpl *strategy,
                                     unsigned connectionId) {
+#ifndef WITH_POLICY
   StrategyRnd *srnd = (StrategyRnd *)strategy->context;
   if (!numberSet_Contains(srnd->nexthops, connectionId)) {
     numberSet_Add(srnd->nexthops, connectionId);
   }
+#endif /* ! WITH_POLICY */
 }
 
 static void _strategyRnd_RemoveNexthop(StrategyImpl *strategy,
                                        unsigned connectionId) {
+#ifndef WITH_POLICY
   StrategyRnd *srnd = (StrategyRnd *)strategy->context;
 
   if (numberSet_Contains(srnd->nexthops, connectionId)) {
     numberSet_Remove(srnd->nexthops, connectionId);
   }
+#endif /* ! WITH_POLICY */
 }
 
 static void _strategyRnd_ImplDestroy(StrategyImpl **strategyPtr) {
@@ -167,7 +195,9 @@ static void _strategyRnd_ImplDestroy(StrategyImpl **strategyPtr) {
   StrategyImpl *impl = *strategyPtr;
   StrategyRnd *strategy = (StrategyRnd *)impl->context;
 
+#ifndef WITH_POLICY
   numberSet_Release(&(strategy->nexthops));
+#endif /* ! WITH_POLICY */
 
   parcMemory_Deallocate((void **)&strategy);
   parcMemory_Deallocate((void **)&impl);
diff --git a/hicn-light/src/hicn/strategies/rnd.h b/hicn-light/src/hicn/strategies/rnd.h
index b57b41ccf..78fb34758 100644
--- a/hicn-light/src/hicn/strategies/rnd.h
+++ b/hicn-light/src/hicn/strategies/rnd.h
@@ -23,4 +23,5 @@
 #include <hicn/strategies/strategyImpl.h>
 
 StrategyImpl* strategyRnd_Create();
+
 #endif  // rnd_h
diff --git a/hicn-light/src/hicn/strategies/rndSegment.c b/hicn-light/src/hicn/strategies/rndSegment.c
index d7a5c6aec..93e39ee74 100644
--- a/hicn-light/src/hicn/strategies/rndSegment.c
+++ b/hicn-light/src/hicn/strategies/rndSegment.c
@@ -33,9 +33,15 @@ static void _strategyRndSegment_ReceiveObject(StrategyImpl *strategy,
 static void _strategyRndSegment_OnTimeout(StrategyImpl *strategy,
                                           const NumberSet *egressId);
 static NumberSet *_strategyRndSegment_LookupNexthop(
-    StrategyImpl *strategy, const Message *interestMessage);
+    StrategyImpl *strategy,
+#ifdef WITH_POLICY
+    NumberSet * nexthops,
+#endif /* WITH_POLICY */
+    const Message *interestMessage);
+#ifndef WITH_POLICY
 static NumberSet *_strategyRndSegment_ReturnNexthops(StrategyImpl *strategy);
 static unsigned _strategyRndSegment_CountNexthops(StrategyImpl *strategy);
+#endif /* ! WITH_POLICY */
 static void _strategyRndSegment_AddNexthop(StrategyImpl *strategy,
                                            unsigned connectionId);
 static void _strategyRndSegment_RemoveNexthop(StrategyImpl *strategy,
@@ -48,8 +54,10 @@ static StrategyImpl _template = {
     .receiveObject = &_strategyRndSegment_ReceiveObject,
     .onTimeout = &_strategyRndSegment_OnTimeout,
     .lookupNexthop = &_strategyRndSegment_LookupNexthop,
+#ifndef WITH_POLICY
     .returnNexthops = &_strategyRndSegment_ReturnNexthops,
     .countNexthops = &_strategyRndSegment_CountNexthops,
+#endif /* ! WITH_POLICY */
     .addNexthop = &_strategyRndSegment_AddNexthop,
     .removeNexthop = &_strategyRndSegment_RemoveNexthop,
     .destroy = &_strategyRndSegment_ImplDestroy,
@@ -111,7 +119,11 @@ static void _strategyRndSegment_OnTimeout(StrategyImpl *strategy,
                                           const NumberSet *egressId) {}
 
 static NumberSet *_strategyRndSegment_LookupNexthop(
-    StrategyImpl *strategy, const Message *interestMessage) {
+    StrategyImpl *strategy,
+#ifdef WITH_POLICY
+    NumberSet * nexthops,
+#endif /* WITH_POLICY */
+    const Message *interestMessage) {
   StrategyRndSegment *srnd = (StrategyRndSegment *)strategy->context;
 
   unsigned in_connection = message_GetIngressConnectionId(interestMessage);
@@ -161,6 +173,7 @@ static NumberSet *_strategyRndSegment_LookupNexthop(
   return out;
 }
 
+#ifndef WITH_POLICY
 static NumberSet *_strategyRndSegment_ReturnNexthops(StrategyImpl *strategy) {
   StrategyRndSegment *srnd = (StrategyRndSegment *)strategy->context;
   return srnd->nexthops;
@@ -170,22 +183,27 @@ unsigned _strategyRndSegment_CountNexthops(StrategyImpl *strategy) {
   StrategyRndSegment *srnd = (StrategyRndSegment *)strategy->context;
   return (unsigned)numberSet_Length(srnd->nexthops);
 }
+#endif /* ! WITH_POLICY */
 
 static void _strategyRndSegment_AddNexthop(StrategyImpl *strategy,
                                            unsigned connectionId) {
+#ifndef WITH_POLICY
   StrategyRndSegment *srnd = (StrategyRndSegment *)strategy->context;
   if (!numberSet_Contains(srnd->nexthops, connectionId)) {
     numberSet_Add(srnd->nexthops, connectionId);
   }
+#endif /* ! WITH_POLICY */
 }
 
 static void _strategyRndSegment_RemoveNexthop(StrategyImpl *strategy,
                                               unsigned connectionId) {
+#ifndef WITH_POLICY
   StrategyRndSegment *srnd = (StrategyRndSegment *)strategy->context;
 
   if (numberSet_Contains(srnd->nexthops, connectionId)) {
     numberSet_Remove(srnd->nexthops, connectionId);
   }
+#endif /* ! WITH_POLICY */
 }
 
 static void _strategyRndSegment_ImplDestroy(StrategyImpl **strategyPtr) {
diff --git a/hicn-light/src/hicn/strategies/rndSegment.h b/hicn-light/src/hicn/strategies/rndSegment.h
index 897ccca47..6694f03e5 100644
--- a/hicn-light/src/hicn/strategies/rndSegment.h
+++ b/hicn-light/src/hicn/strategies/rndSegment.h
@@ -23,5 +23,6 @@
 
 #include <hicn/strategies/strategyImpl.h>
 
-StrategyImpl* strategyRndSegment_Create();
+StrategyImpl *strategyRndSegment_Create();
+
 #endif  // rnd_Segment_h
diff --git a/hicn-light/src/hicn/strategies/strategyImpl.h b/hicn-light/src/hicn/strategies/strategyImpl.h
index 2634665eb..d4001194a 100644
--- a/hicn-light/src/hicn/strategies/strategyImpl.h
+++ b/hicn-light/src/hicn/strategies/strategyImpl.h
@@ -55,12 +55,18 @@ struct strategy_impl {
                         const Message *objectMessage, Ticks rtt);
   void (*onTimeout)(StrategyImpl *strategy, const NumberSet *egressId);
   NumberSet *(*lookupNexthop)(StrategyImpl *strategy,
+#ifdef WITH_POLICY
+    NumberSet * nexthops,
+#endif /* WITH_POLICY */
                               const Message *interestMessage);
+#ifndef WITH_POLICY
   NumberSet *(*returnNexthops)(StrategyImpl *strategy);
   unsigned (*countNexthops)(StrategyImpl *strategy);
+#endif /* ! WITH_POLICY */
   void (*addNexthop)(StrategyImpl *strategy, unsigned connectionId);
   void (*removeNexthop)(StrategyImpl *strategy, unsigned connectionId);
   void (*destroy)(StrategyImpl **strategyPtr);
   strategy_type (*getStrategy)(StrategyImpl *strategy);
 };
+
 #endif  // strategyImpl_h