DOS: Respect max per-peer blocks in flight limit

Don't allow immediate inv driven block downloads if
a peer already has MAX_BLOCKS_IN_TRANSIT_PER_PEER
active downloads.  Prevents bogus inv spam from
blowing up block transfer tracking data structures.

Rebased-From: c90770430d
Github-Pull: #5507
This commit is contained in:
Adam Weiss 2014-12-18 18:28:29 -05:00 committed by Wladimir J. van der Laan
parent 15ad0b54fa
commit d10a9015ad
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@ -3641,7 +3641,9 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv,
// doing this will result in the received block being rejected as an orphan in case it is
// not a direct successor.
pfrom->PushMessage("getheaders", chainActive.GetLocator(pindexBestHeader), inv.hash);
if (chainActive.Tip()->GetBlockTime() > GetAdjustedTime() - Params().TargetSpacing() * 20) {
CNodeState *nodestate = State(pfrom->GetId());
if (chainActive.Tip()->GetBlockTime() > GetAdjustedTime() - Params().TargetSpacing() * 20 &&
nodestate->nBlocksInFlight < MAX_BLOCKS_IN_TRANSIT_PER_PEER) {
vToFetch.push_back(inv);
// Mark block as in flight already, even though the actual "getdata" message only goes out
// later (within the same cs_main lock, though).