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author | Suhas Daftuar <sdaftuar@gmail.com> | 2016-12-14 17:00:06 -0500 |
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committer | Suhas Daftuar <sdaftuar@gmail.com> | 2016-12-14 17:00:06 -0500 |
commit | 4ced31325699dc308571010ce004376d2915cd7e (patch) | |
tree | 75f3191e794c5e9deb1e94ea933a112af40fd113 /src | |
parent | 0a4aa876230c602427aa40b47a84698a3fd28e85 (diff) | |
download | bitcoin-4ced31325699dc308571010ce004376d2915cd7e.tar.xz |
Allow compactblock reconstruction when block is in flight
Diffstat (limited to 'src')
-rw-r--r-- | src/main.cpp | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/src/main.cpp b/src/main.cpp index 191bcff4cc..976e130f1a 100644 --- a/src/main.cpp +++ b/src/main.cpp @@ -5657,6 +5657,11 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv, CBlockHeaderAndShortTxIDs cmpctblock; vRecv >> cmpctblock; + // Keep a CBlock for "optimistic" compactblock reconstructions (see + // below) + CBlock block; + bool fBlockReconstructed = false; + LOCK(cs_main); if (mapBlockIndex.find(cmpctblock.header.hashPrevBlock) == mapBlockIndex.end()) { @@ -5765,6 +5770,23 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv, req.blockhash = pindex->GetBlockHash(); pfrom->PushMessage(NetMsgType::GETBLOCKTXN, req); } + } else { + // This block is either already in flight from a different + // peer, or this peer has too many blocks outstanding to + // download from. + // Optimistically try to reconstruct anyway since we might be + // able to without any round trips. + PartiallyDownloadedBlock tempBlock(&mempool); + ReadStatus status = tempBlock.InitData(cmpctblock); + if (status != READ_STATUS_OK) { + // TODO: don't ignore failures + return true; + } + std::vector<CTransaction> dummy; + status = tempBlock.FillBlock(block, dummy); + if (status == READ_STATUS_OK) { + fBlockReconstructed = true; + } } } else { if (fAlreadyInFlight) { @@ -5785,6 +5807,33 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv, } } + if (fBlockReconstructed) { + // If we got here, we were able to optimistically reconstruct a + // block that is in flight from some other peer. However, this + // cmpctblock may be invalid. In particular, while we've checked + // that the block merkle root commits to the transaction ids, we + // haven't yet checked that tx witnesses are properly committed to + // in the coinbase witness commitment. + // + // ProcessNewBlock will call MarkBlockAsReceived(), which will + // clear any in-flight compact block state that might be present + // from some other peer. We don't want a malleated compact block + // request to interfere with block relay, so we don't want to call + // ProcessNewBlock until we've already checked that the witness + // commitment is correct. + { + LOCK(cs_main); + CValidationState dummy; + if (!ContextualCheckBlock(block, dummy, pindex->pprev)) { + // TODO: could send reject message to peer? + return true; + } + } + CValidationState state; + ProcessNewBlock(state, chainparams, pfrom, &block, true, NULL, false); + // TODO: could send reject message if block is invalid? + } + CheckBlockIndex(chainparams.GetConsensus()); } |