Compute idling based on feature flag and node node version

Author: agustinmista

ouroboros-consensus-diffusion/src/ouroboros-consensus-diffusion/Ouroboros/Consensus/NodeKernel.hs

@@ -148,6 +148,7 @@ import Ouroboros.Network.BlockFetch.Decision.Trace
 import Ouroboros.Network.NodeToNode
   ( ConnectionId
   , MiniProtocolParameters (..)
+  , NodeToNodeVersion (..)
   )
 import Ouroboros.Network.PeerSelection.Governor.Types
   ( PublicPeerSelectionState
@@ -274,20 +275,24 @@ mkNodeKernelPeerStates csHandles pcdHandles = do
   pcdPeerStates <- traverse (readTVar . odihState) =<< odihcMap pcdHandles
   pure (NodeKernelPeerState <$> align csPeerStates pcdPeerStates)
 
-nodeKernelPeerIsIdle :: NodeKernelPeerState blk -> Bool
-nodeKernelPeerIsIdle (NodeKernelPeerState these) =
+nodeKernelPeerIsIdle :: Set CardanoFeatureFlag -> NodeKernelPeerState blk -> Bool
+nodeKernelPeerIsIdle featureFlags (NodeKernelPeerState these) =
   case these of
     -- We have both ChainSync and PerasCertDiffusion connections => idle if both are idling
     These csState pcdState -> csIdling csState && odisIdling pcdState
     -- Only a ChainSync connection is available => idle if the ChainSync connection is idling
-    This csState | not peerUsesPeras -> csIdling csState
+    This csState | not perasIsEnabled -> csIdling csState
+    This csState | not (peerUsesPeras csState) -> csIdling csState
     -- We will soon establish a PerasCertDiffusion connection => not idling
     This _ -> False
     -- We will soon establish a ChainSync connection => not idling
     That _ -> False
  where
-  -- TODO: use the Peras feature flag or check negotiated NodeToNode version for the peer
-  peerUsesPeras = False
+  -- Is the Peras feature flag enabled?
+  perasIsEnabled = PerasFlag `elem` featureFlags
+
+  -- Does the peer support the Peras mini-protocol?
+  peerUsesPeras csState = csNodeToNodeVersion csState >= NodeToNodeV_16
 
 initNodeKernel ::
   forall m addrNTN addrNTC blk.
@@ -304,6 +309,7 @@ initNodeKernel
   args@NodeKernelArgs
     { registry
     , cfg
+    , featureFlags
     , tracers
     , chainDB
     , initChainDB
@@ -363,7 +369,7 @@ initNodeKernel
                           -- We don't have an established ChainSync connection with this peer.
                           -- We conservatively assume that its candidate is not better than ours.
                           GSM.WhetherCandidateIsBetter False
-                , GSM.peerIsIdle = nodeKernelPeerIsIdle
+                , GSM.peerIsIdle = nodeKernelPeerIsIdle featureFlags
                 , GSM.durationUntilTooOld =
                     gsmDurationUntilTooOld
                       <&> \wd (_headers, lst) ->