(dot/parachain): handle view update message network bridge

Over the network through collation and validation protocol, as part of WireMessage we could get a PeerMessage or a ViewUpdate.

ViewUpdate tells us about latest blocks (heads) and finalized number with our peers.

We are supposed to be update our peer data with these views.

This commit, reads ViewUpdate from both collation and validation protocol and handles them inside network bridge by updating our peer data. Later, it sends that view to other subsystems so that each subsystem can update their view too.

Fixes #3864

dot/parachain/network-bridge/events/events.go

@@ -60,6 +60,20 @@ type View struct {
 	FinalizedNumber uint32
 }
 
+func (v View) Equals(v2 View) bool {
+	if v.FinalizedNumber != v.FinalizedNumber {
+		return false
+	}
+
+	for i, head := range v.Heads {
+		if head != v2.Heads[i] {
+			return false
+		}
+	}
+
+	return true
+}
+
 type OurViewChange struct {
 	View View
 }

dot/parachain/network-bridge/receiver.go

@@ -15,6 +15,7 @@ import (
 	events "github.com/ChainSafe/gossamer/dot/parachain/network-bridge/events"
 	networkbridgemessages "github.com/ChainSafe/gossamer/dot/parachain/network-bridge/messages"
 	validationprotocol "github.com/ChainSafe/gossamer/dot/parachain/validation-protocol"
+	"github.com/ChainSafe/gossamer/dot/peerset"
 
 	parachaintypes "github.com/ChainSafe/gossamer/dot/parachain/types"
 
@@ -28,6 +29,8 @@ import (
 
 var logger = log.NewFromGlobal(log.AddContext("pkg", "network-bridge"))
 
+const newMaxHeads = 5
+
 var (
 	ErrFinalizedNumber                       = errors.New("finalized number is greater than or equal to the block number")
 	ErrInvalidStringFormat                   = errors.New("invalid string format for fetched collation info")
@@ -274,7 +277,7 @@ func (nbr *NetworkBridgeReceiver) handleCollationMessage(
 				"failed to cast into view update, expected: *ViewUpdate, got: %T",
 				value)
 		}
-		nbr.handleViewUpdate(*viewUpdate)
+		nbr.handleViewUpdate(sender, *viewUpdate)
 
 	}
 
@@ -320,14 +323,50 @@ func (nbr *NetworkBridgeReceiver) handleValidationMessage(
 				"failed to cast into view update, expected: *ViewUpdate, got: %T",
 				value)
 		}
-		nbr.handleViewUpdate(*viewUpdate)
+		nbr.handleViewUpdate(sender, *viewUpdate)
 	}
 
 	return propagate, nil
 }
 
-func (nbr *NetworkBridgeReceiver) handleViewUpdate(view ViewUpdate) {
+func (nbr *NetworkBridgeReceiver) handleViewUpdate(peer peer.ID, view ViewUpdate) error {
+
+	peerData, ok := nbr.peerData[peer]
+	if !ok {
+		return errors.New("peer not found")
+	}
+	if len(view.Heads) > newMaxHeads || view.FinalizedNumber < peerData.view.FinalizedNumber {
+		nbr.net.ReportPeer(peerset.ReputationChange{
+			Value:  peerset.CostMajor,
+			Reason: "malformed view",
+		}, peer)
+	} else if len(view.Heads) == 0 {
+		nbr.net.ReportPeer(peerset.ReputationChange{
+			Value:  peerset.CostMinor,
+			Reason: "peer sent us empty view",
+		}, peer)
+	} else if events.View(view).Equals(events.View(peerData.view)) {
+		// nothing
+	} else {
+		peerData.view = View(view)
+		nbr.peerData[peer] = peerData
+
+		nbr.SubsystemsToOverseer <- events.Event[collatorprotocolmessages.CollationProtocol]{
+			Inner: events.PeerViewChange{
+				PeerID: peer,
+				View:   events.View(view),
+			},
+		}
 
+		nbr.SubsystemsToOverseer <- events.Event[validationprotocol.ValidationProtocol]{
+			Inner: events.PeerViewChange{
+				PeerID: peer,
+				View:   events.View(view),
+			},
+		}
+	}
+
+	return nil
 }
 
 func (nbr *NetworkBridgeReceiver) ProcessBlockFinalizedSignal(signal parachaintypes.BlockFinalizedSignal) error {