From 29c45185223441943ab610e62937a118c7c3a5b2 Mon Sep 17 00:00:00 2001 From: Suhas Daftuar Date: Tue, 8 Feb 2022 17:33:32 -0500 Subject: Move headers-direct-fetch logic into own function --- src/net_processing.cpp | 126 ++++++++++++++++++++++++++++--------------------- 1 file changed, 72 insertions(+), 54 deletions(-) (limited to 'src/net_processing.cpp') diff --git a/src/net_processing.cpp b/src/net_processing.cpp index 795851c491..189556e03e 100644 --- a/src/net_processing.cpp +++ b/src/net_processing.cpp @@ -569,6 +569,8 @@ private: bool CheckHeadersAreContinuous(const std::vector& headers) const; /** Request further headers from this peer from a given block header */ void FetchMoreHeaders(CNode& pfrom, const CBlockIndex *pindexLast, const Peer& peer); + /** Potentially fetch blocks from this peer upon receipt of new headers tip */ + void HeadersDirectFetchBlocks(CNode& pfrom, const CBlockIndex* pindexLast); void SendBlockTransactions(CNode& pfrom, Peer& peer, const CBlock& block, const BlockTransactionsRequest& req); @@ -2276,6 +2278,73 @@ void PeerManagerImpl::FetchMoreHeaders(CNode& pfrom, const CBlockIndex *pindexLa m_connman.PushMessage(&pfrom, msgMaker.Make(NetMsgType::GETHEADERS, m_chainman.ActiveChain().GetLocator(pindexLast), uint256())); } +/* + * Given a new headers tip ending in pindexLast, potentially request blocks towards that tip. + * We require that the given tip have at least as much work as our tip, and for + * our current tip to be "close to synced" (see CanDirectFetch()). + */ +void PeerManagerImpl::HeadersDirectFetchBlocks(CNode& pfrom, const CBlockIndex* pindexLast) +{ + const CNetMsgMaker msgMaker(pfrom.GetCommonVersion()); + + LOCK(cs_main); + CNodeState *nodestate = State(pfrom.GetId()); + + if (CanDirectFetch() && pindexLast->IsValid(BLOCK_VALID_TREE) && m_chainman.ActiveChain().Tip()->nChainWork <= pindexLast->nChainWork) { + + std::vector vToFetch; + const CBlockIndex *pindexWalk = pindexLast; + // Calculate all the blocks we'd need to switch to pindexLast, up to a limit. + while (pindexWalk && !m_chainman.ActiveChain().Contains(pindexWalk) && vToFetch.size() <= MAX_BLOCKS_IN_TRANSIT_PER_PEER) { + if (!(pindexWalk->nStatus & BLOCK_HAVE_DATA) && + !IsBlockRequested(pindexWalk->GetBlockHash()) && + (!DeploymentActiveAt(*pindexWalk, m_chainman, Consensus::DEPLOYMENT_SEGWIT) || State(pfrom.GetId())->fHaveWitness)) { + // We don't have this block, and it's not yet in flight. + vToFetch.push_back(pindexWalk); + } + pindexWalk = pindexWalk->pprev; + } + // If pindexWalk still isn't on our main chain, we're looking at a + // very large reorg at a time we think we're close to caught up to + // the main chain -- this shouldn't really happen. Bail out on the + // direct fetch and rely on parallel download instead. + if (!m_chainman.ActiveChain().Contains(pindexWalk)) { + LogPrint(BCLog::NET, "Large reorg, won't direct fetch to %s (%d)\n", + pindexLast->GetBlockHash().ToString(), + pindexLast->nHeight); + } else { + std::vector vGetData; + // Download as much as possible, from earliest to latest. + for (const CBlockIndex *pindex : reverse_iterate(vToFetch)) { + if (nodestate->nBlocksInFlight >= MAX_BLOCKS_IN_TRANSIT_PER_PEER) { + // Can't download any more from this peer + break; + } + uint32_t nFetchFlags = GetFetchFlags(pfrom); + vGetData.push_back(CInv(MSG_BLOCK | nFetchFlags, pindex->GetBlockHash())); + BlockRequested(pfrom.GetId(), *pindex); + LogPrint(BCLog::NET, "Requesting block %s from peer=%d\n", + pindex->GetBlockHash().ToString(), pfrom.GetId()); + } + if (vGetData.size() > 1) { + LogPrint(BCLog::NET, "Downloading blocks toward %s (%d) via headers direct fetch\n", + pindexLast->GetBlockHash().ToString(), pindexLast->nHeight); + } + if (vGetData.size() > 0) { + if (!m_ignore_incoming_txs && + nodestate->m_provides_cmpctblocks && + vGetData.size() == 1 && + mapBlocksInFlight.size() == 1 && + pindexLast->pprev->IsValid(BLOCK_VALID_CHAIN)) { + // In any case, we want to download using a compact block, not a regular one + vGetData[0] = CInv(MSG_CMPCT_BLOCK, vGetData[0].hash); + } + m_connman.PushMessage(&pfrom, msgMaker.Make(NetMsgType::GETDATA, vGetData)); + } + } + } +} + void PeerManagerImpl::ProcessHeadersMessage(CNode& pfrom, Peer& peer, const std::vector& headers, bool via_compact_block) @@ -2355,60 +2424,9 @@ void PeerManagerImpl::ProcessHeadersMessage(CNode& pfrom, Peer& peer, nodestate->m_last_block_announcement = GetTime(); } - // If this set of headers is valid and ends in a block with at least as - // much work as our tip, download as much as possible. - if (CanDirectFetch() && pindexLast->IsValid(BLOCK_VALID_TREE) && m_chainman.ActiveChain().Tip()->nChainWork <= pindexLast->nChainWork) { - std::vector vToFetch; - const CBlockIndex *pindexWalk = pindexLast; - // Calculate all the blocks we'd need to switch to pindexLast, up to a limit. - while (pindexWalk && !m_chainman.ActiveChain().Contains(pindexWalk) && vToFetch.size() <= MAX_BLOCKS_IN_TRANSIT_PER_PEER) { - if (!(pindexWalk->nStatus & BLOCK_HAVE_DATA) && - !IsBlockRequested(pindexWalk->GetBlockHash()) && - (!DeploymentActiveAt(*pindexWalk, m_chainman, Consensus::DEPLOYMENT_SEGWIT) || State(pfrom.GetId())->fHaveWitness)) { - // We don't have this block, and it's not yet in flight. - vToFetch.push_back(pindexWalk); - } - pindexWalk = pindexWalk->pprev; - } - // If pindexWalk still isn't on our main chain, we're looking at a - // very large reorg at a time we think we're close to caught up to - // the main chain -- this shouldn't really happen. Bail out on the - // direct fetch and rely on parallel download instead. - if (!m_chainman.ActiveChain().Contains(pindexWalk)) { - LogPrint(BCLog::NET, "Large reorg, won't direct fetch to %s (%d)\n", - pindexLast->GetBlockHash().ToString(), - pindexLast->nHeight); - } else { - std::vector vGetData; - // Download as much as possible, from earliest to latest. - for (const CBlockIndex *pindex : reverse_iterate(vToFetch)) { - if (nodestate->nBlocksInFlight >= MAX_BLOCKS_IN_TRANSIT_PER_PEER) { - // Can't download any more from this peer - break; - } - uint32_t nFetchFlags = GetFetchFlags(pfrom); - vGetData.push_back(CInv(MSG_BLOCK | nFetchFlags, pindex->GetBlockHash())); - BlockRequested(pfrom.GetId(), *pindex); - LogPrint(BCLog::NET, "Requesting block %s from peer=%d\n", - pindex->GetBlockHash().ToString(), pfrom.GetId()); - } - if (vGetData.size() > 1) { - LogPrint(BCLog::NET, "Downloading blocks toward %s (%d) via headers direct fetch\n", - pindexLast->GetBlockHash().ToString(), pindexLast->nHeight); - } - if (vGetData.size() > 0) { - if (!m_ignore_incoming_txs && - nodestate->m_provides_cmpctblocks && - vGetData.size() == 1 && - mapBlocksInFlight.size() == 1 && - pindexLast->pprev->IsValid(BLOCK_VALID_CHAIN)) { - // In any case, we want to download using a compact block, not a regular one - vGetData[0] = CInv(MSG_CMPCT_BLOCK, vGetData[0].hash); - } - m_connman.PushMessage(&pfrom, msgMaker.Make(NetMsgType::GETDATA, vGetData)); - } - } - } + // Consider immediately downloading blocks. + HeadersDirectFetchBlocks(pfrom, pindexLast); + // If we're in IBD, we want outbound peers that will serve us a useful // chain. Disconnect peers that are on chains with insufficient work. if (m_chainman.ActiveChainstate().IsInitialBlockDownload() && nCount != MAX_HEADERS_RESULTS) { -- cgit v1.2.3