void Intercept(IncomingMessage message, Action act)
{
var inv = message.Message.Payload as InvPayload;
if (inv != null)
{
if (inv.Inventory.Any(i => ((i.Type & InventoryType.MSG_BLOCK) != 0) && !Chain.Contains(i.Hash)))
{
_Refresh.Dispose(); //No need of periodical refresh, the peer is notifying us
if (AutoSync)
{
TrySync();
}
}
}
// == GetHeadersPayload ==
// represents our height from the peer's point of view
// it is sent from the peer on first connect, in response to Inv(Block)
// or in response to HeaderPayload until an empty array is returned
// this payload notifies peers of our current best validated height
// use the ChainState.HighestValidatedPoW property (not Chain.Tip)
// if the peer is behind/equal to our best height an empty array is sent back
// Ignoring getheaders from peers because node is in initial block download
var getheaders = message.Message.Payload as GetHeadersPayload;
if (getheaders != null && CanRespondToGetHeaders &&
(!this.SharedState.IsInitialBlockDownload ||
this.AttachedNode.Behavior <ConnectionManagerBehavior>().Whitelisted)) // if not in IBD whitelisted won't be checked
{
HeadersPayload headers = new HeadersPayload();
var highestPow = SharedState.HighestValidatedPoW;
highestPow = Chain.GetBlock(highestPow.HashBlock);
var fork = Chain.FindFork(getheaders.BlockLocators);
if (fork != null)
{
if (highestPow == null || fork.Height > highestPow.Height)
{
fork = null; //fork not yet validated
}
if (fork != null)
{
foreach (var header in Chain.EnumerateToTip(fork).Skip(1))
{
if (header.Height > highestPow.Height)
{
break;
}
headers.Headers.Add(header.Header);
if (header.HashBlock == getheaders.HashStop || headers.Headers.Count == 2000)
{
break;
}
}
}
}
AttachedNode.SendMessageAsync(headers);
}
// == HeadersPayload ==
// represents the peers height from our point view
// this updates the pending tip parameter which is the
// peers current best validated height
// if the peer's height is higher Chain.Tip is updated to have
// the most PoW header
// is sent in response to GetHeadersPayload or is solicited by the
// peer when a new block is validated (and not in IBD)
var newheaders = message.Message.Payload as HeadersPayload;
var pendingTipBefore = GetPendingTipOrChainTip();
if (newheaders != null && CanSync)
{
// TODO: implement MAX_HEADERS_RESULTS in NBitcoin.HeadersPayload
var tip = GetPendingTipOrChainTip();
foreach (var header in newheaders.Headers)
{
var prev = tip.FindAncestorOrSelf(header.HashPrevBlock);
if (prev == null)
{
break;
}
tip = new ChainedBlock(header, header.GetHash(), prev);
var validated = Chain.GetBlock(tip.HashBlock) != null || tip.Validate(AttachedNode.Network);
validated &= !SharedState.IsMarkedInvalid(tip.HashBlock);
if (!validated)
{
invalidHeaderReceived = true;
break;
}
_PendingTip = tip;
}
if (_PendingTip.ChainWork > Chain.Tip.ChainWork)
{
Chain.SetTip(_PendingTip);
}
var chainedPendingTip = Chain.GetBlock(_PendingTip.HashBlock);
if (chainedPendingTip != null)
{
_PendingTip = chainedPendingTip; //This allows garbage collection to collect the duplicated pendingtip and ancestors
}
if (newheaders.Headers.Count != 0 && pendingTipBefore.HashBlock != GetPendingTipOrChainTip().HashBlock)
{
TrySync();
}
Interlocked.Decrement(ref _SynchingCount);
}
act();
}
void Intercept(IncomingMessage message, Action act)
{
var inv = message.Message.Payload as InvPayload;
if (inv != null)
{
if (inv.Inventory.Any(i => ((i.Type & InventoryType.MSG_BLOCK) != 0) && !Chain.Contains(i.Hash)))
{
_Refresh.Dispose(); //No need of periodical refresh, the peer is notifying us
if (AutoSync)
{
TrySync();
}
}
}
var getheaders = message.Message.Payload as GetHeadersPayload;
if (getheaders != null && CanRespondToGetHeaders && !StripHeader)
{
HeadersPayload headers = new HeadersPayload();
var highestPow = SharedState.HighestValidatedPoW;
highestPow = highestPow == null ? null : Chain.GetBlock(highestPow.HashBlock);
var fork = Chain.FindFork(getheaders.BlockLocators);
if (fork != null)
{
if (highestPow != null && fork.Height > highestPow.Height)
{
fork = null; //fork not yet validated
}
if (fork != null)
{
foreach (var header in Chain.EnumerateToTip(fork).Skip(1))
{
if (highestPow != null && header.Height > highestPow.Height)
{
break;
}
headers.Headers.Add(header.Header);
if (header.HashBlock == getheaders.HashStop || headers.Headers.Count == 2000)
{
break;
}
}
}
}
AttachedNode.SendMessageAsync(headers);
}
var newheaders = message.Message.Payload as HeadersPayload;
var pendingTipBefore = GetPendingTipOrChainTip();
if (newheaders != null && CanSync)
{
var tip = GetPendingTipOrChainTip();
foreach (var header in newheaders.Headers)
{
var prev = tip.FindAncestorOrSelf(header.HashPrevBlock);
if (prev == null)
{
break;
}
tip = new ChainedBlock(header, header.GetHash(), prev);
var validated = Chain.GetBlock(tip.HashBlock) != null || (SkipPoWCheck || tip.Validate(AttachedNode.Network));
validated &= !SharedState.IsMarkedInvalid(tip.HashBlock);
if (!validated)
{
invalidHeaderReceived = true;
break;
}
_PendingTip = tip;
}
bool isHigherBlock = false;
if (SkipPoWCheck)
{
isHigherBlock = _PendingTip.Height > Chain.Tip.Height;
}
else
{
isHigherBlock = _PendingTip.GetChainWork(true) > Chain.Tip.GetChainWork(true);
}
if (isHigherBlock)
{
Chain.SetTip(_PendingTip);
if (StripHeader)
{
_PendingTip.StripHeader();
}
}
var chainedPendingTip = Chain.GetBlock(_PendingTip.HashBlock);
if (chainedPendingTip != null)
{
_PendingTip = chainedPendingTip; //This allows garbage collection to collect the duplicated pendingtip and ancestors
}
if (newheaders.Headers.Count != 0 && pendingTipBefore.HashBlock != GetPendingTipOrChainTip().HashBlock)
{
TrySync();
}
Interlocked.Decrement(ref _SynchingCount);
}
act();
}