private void OnChangeViewReceived(ExtensiblePayload payload, ChangeView message)
{
if (message.NewViewNumber <= context.ViewNumber)
{
OnRecoveryRequestReceived(payload, message);
}
if (context.CommitSent)
{
return;
}
var expectedView = context.GetMessage <ChangeView>(context.ChangeViewPayloads[message.ValidatorIndex])?.NewViewNumber ?? 0;
if (message.NewViewNumber <= expectedView)
{
return;
}
Log($"{nameof(OnChangeViewReceived)}: height={message.BlockIndex} view={message.ViewNumber} index={message.ValidatorIndex} nv={message.NewViewNumber} reason={message.Reason}");
context.ChangeViewPayloads[message.ValidatorIndex] = payload;
CheckExpectedView(message.NewViewNumber);
}
private void OnChangeViewReceived(ConsensusPayload payload, ChangeView message)
{
if (message.NewViewNumber <= context.ViewNumber)
{
OnRecoveryRequestReceived(payload);
}
if (context.CommitSent())
{
return;
}
var expectedView = context.ChangeViewPayloads[payload.ValidatorIndex]?.GetDeserializedMessage <ChangeView>().NewViewNumber ?? (byte)0;
if (message.NewViewNumber <= expectedView)
{
return;
}
Log($"{nameof(OnChangeViewReceived)}: height={payload.BlockIndex} view={message.ViewNumber} index={payload.ValidatorIndex} nv={message.NewViewNumber}");
context.ChangeViewPayloads[payload.ValidatorIndex] = payload;
CheckExpectedView(message.NewViewNumber);
}
private void CheckExpectedView(byte viewNumber)
{
if (context.ViewNumber >= viewNumber)
{
return;
}
// if there are `M` change view payloads with NewViewNumber greater than viewNumber, then, it is safe to move
if (context.ChangeViewPayloads.Count(p => p != null && p.GetDeserializedMessage <ChangeView>().NewViewNumber >= viewNumber) >= context.M)
{
if (!context.WatchOnly)
{
ChangeView message = context.ChangeViewPayloads[context.MyIndex]?.GetDeserializedMessage <ChangeView>();
// Communicate the network about my agreement to move to `viewNumber`
// if my last change view payload, `message`, has NewViewNumber lower than current view to change
if (message is null || message.NewViewNumber < viewNumber)
{
localNode.Tell(new LocalNode.SendDirectly {
Inventory = context.MakeChangeView(ChangeViewReason.ChangeAgreement)
});
}
}
InitializeConsensus(viewNumber);
}
}
private void OnChangeViewReceived(ConsensusPayload payload, ChangeView message)
{
// We keep track of the payload hashes received in this block, and don't respond with recovery
// in response to the same payload that we already responded to previously.
// ChangeView messages include a Timestamp when the change view is sent, thus if a node restarts
// and issues a change view for the same view, it will have a different hash and will correctly respond
// again; however replay attacks of the ChangeView message from arbitrary nodes will not trigger an
// additional recovery message response.
if (!knownHashes.Add(payload.Hash))
{
return;
}
if (message.NewViewNumber <= context.ViewNumber)
{
if (context.WatchOnly())
{
return;
}
if (!context.CommitSent())
{
bool shouldSendRecovery = false;
// Limit recovery to be sent from, at least, `f` nodes when the request is from a lower view number.
int allowedRecoveryNodeCount = context.F();
for (int i = 0; i < allowedRecoveryNodeCount; i++)
{
var eligibleResponders = context.Validators.Length - 1;
var chosenIndex = (payload.ValidatorIndex + i + message.NewViewNumber) % eligibleResponders;
if (chosenIndex >= payload.ValidatorIndex)
{
chosenIndex++;
}
if (chosenIndex != context.MyIndex)
{
continue;
}
shouldSendRecovery = true;
break;
}
if (!shouldSendRecovery)
{
return;
}
}
Log($"send recovery from view: {message.ViewNumber} to view: {context.ViewNumber}");
localNode.Tell(new LocalNode.SendDirectly {
Inventory = context.MakeRecoveryMessage()
});
}
if (context.CommitSent())
{
return;
}
var expectedView = context.ChangeViewPayloads[payload.ValidatorIndex]?.GetDeserializedMessage <ChangeView>().NewViewNumber ?? (byte)0;
if (message.NewViewNumber <= expectedView)
{
return;
}
Log($"{nameof(OnChangeViewReceived)}: height={payload.BlockIndex} view={message.ViewNumber} index={payload.ValidatorIndex} nv={message.NewViewNumber}");
context.ChangeViewPayloads[payload.ValidatorIndex] = payload;
CheckExpectedView(message.NewViewNumber);
}
