From 6d95cd3e7444ebaaabb64a76783ea3551530f1d7 Mon Sep 17 00:00:00 2001 From: Suhas Daftuar Date: Tue, 8 Feb 2022 17:40:33 -0500 Subject: Move peer state updates from headers message into separate function --- src/net_processing.cpp | 117 +++++++++++++++++++++++++++---------------------- 1 file changed, 64 insertions(+), 53 deletions(-) diff --git a/src/net_processing.cpp b/src/net_processing.cpp index 2be5d5f50d..5f19f8b8ec 100644 --- a/src/net_processing.cpp +++ b/src/net_processing.cpp @@ -571,6 +571,8 @@ private: 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); + /** Update peer state based on received headers message */ + void UpdatePeerStateForReceivedHeaders(CNode& pfrom, const CBlockIndex *pindexLast, bool received_new_header, bool may_have_more_headers); void SendBlockTransactions(CNode& pfrom, Peer& peer, const CBlock& block, const BlockTransactionsRequest& req); @@ -2345,6 +2347,67 @@ void PeerManagerImpl::HeadersDirectFetchBlocks(CNode& pfrom, const CBlockIndex* } } +/** + * Given receipt of headers from a peer ending in pindexLast, along with + * whether that header was new and whether the headers message was full, + * update the state we keep for the peer. + */ +void PeerManagerImpl::UpdatePeerStateForReceivedHeaders(CNode& pfrom, + const CBlockIndex *pindexLast, bool received_new_header, bool may_have_more_headers) +{ + LOCK(cs_main); + CNodeState *nodestate = State(pfrom.GetId()); + if (nodestate->nUnconnectingHeaders > 0) { + LogPrint(BCLog::NET, "peer=%d: resetting nUnconnectingHeaders (%d -> 0)\n", pfrom.GetId(), nodestate->nUnconnectingHeaders); + } + nodestate->nUnconnectingHeaders = 0; + + assert(pindexLast); + UpdateBlockAvailability(pfrom.GetId(), pindexLast->GetBlockHash()); + + // From here, pindexBestKnownBlock should be guaranteed to be non-null, + // because it is set in UpdateBlockAvailability. Some nullptr checks + // are still present, however, as belt-and-suspenders. + + if (received_new_header && pindexLast->nChainWork > m_chainman.ActiveChain().Tip()->nChainWork) { + nodestate->m_last_block_announcement = GetTime(); + } + + // 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() && !may_have_more_headers) { + // If the peer has no more headers to give us, then we know we have + // their tip. + if (nodestate->pindexBestKnownBlock && nodestate->pindexBestKnownBlock->nChainWork < nMinimumChainWork) { + // This peer has too little work on their headers chain to help + // us sync -- disconnect if it is an outbound disconnection + // candidate. + // Note: We compare their tip to nMinimumChainWork (rather than + // m_chainman.ActiveChain().Tip()) because we won't start block download + // until we have a headers chain that has at least + // nMinimumChainWork, even if a peer has a chain past our tip, + // as an anti-DoS measure. + if (pfrom.IsOutboundOrBlockRelayConn()) { + LogPrintf("Disconnecting outbound peer %d -- headers chain has insufficient work\n", pfrom.GetId()); + pfrom.fDisconnect = true; + } + } + } + + // If this is an outbound full-relay peer, check to see if we should protect + // it from the bad/lagging chain logic. + // Note that outbound block-relay peers are excluded from this protection, and + // thus always subject to eviction under the bad/lagging chain logic. + // See ChainSyncTimeoutState. + if (!pfrom.fDisconnect && pfrom.IsFullOutboundConn() && nodestate->pindexBestKnownBlock != nullptr) { + if (m_outbound_peers_with_protect_from_disconnect < MAX_OUTBOUND_PEERS_TO_PROTECT_FROM_DISCONNECT && nodestate->pindexBestKnownBlock->nChainWork >= m_chainman.ActiveChain().Tip()->nChainWork && !nodestate->m_chain_sync.m_protect) { + LogPrint(BCLog::NET, "Protecting outbound peer=%d from eviction\n", pfrom.GetId()); + nodestate->m_chain_sync.m_protect = true; + ++m_outbound_peers_with_protect_from_disconnect; + } + } +} + void PeerManagerImpl::ProcessHeadersMessage(CNode& pfrom, Peer& peer, const std::vector& headers, bool via_compact_block) @@ -2405,59 +2468,7 @@ void PeerManagerImpl::ProcessHeadersMessage(CNode& pfrom, Peer& peer, FetchMoreHeaders(pfrom, pindexLast, peer); } - { - LOCK(cs_main); - CNodeState *nodestate = State(pfrom.GetId()); - if (nodestate->nUnconnectingHeaders > 0) { - LogPrint(BCLog::NET, "peer=%d: resetting nUnconnectingHeaders (%d -> 0)\n", pfrom.GetId(), nodestate->nUnconnectingHeaders); - } - nodestate->nUnconnectingHeaders = 0; - - assert(pindexLast); - UpdateBlockAvailability(pfrom.GetId(), pindexLast->GetBlockHash()); - - // From here, pindexBestKnownBlock should be guaranteed to be non-null, - // because it is set in UpdateBlockAvailability. Some nullptr checks - // are still present, however, as belt-and-suspenders. - - if (received_new_header && pindexLast->nChainWork > m_chainman.ActiveChain().Tip()->nChainWork) { - nodestate->m_last_block_announcement = GetTime(); - } - - // 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) { - // When nCount < MAX_HEADERS_RESULTS, we know we have no more - // headers to fetch from this peer. - if (nodestate->pindexBestKnownBlock && nodestate->pindexBestKnownBlock->nChainWork < nMinimumChainWork) { - // This peer has too little work on their headers chain to help - // us sync -- disconnect if it is an outbound disconnection - // candidate. - // Note: We compare their tip to nMinimumChainWork (rather than - // m_chainman.ActiveChain().Tip()) because we won't start block download - // until we have a headers chain that has at least - // nMinimumChainWork, even if a peer has a chain past our tip, - // as an anti-DoS measure. - if (pfrom.IsOutboundOrBlockRelayConn()) { - LogPrintf("Disconnecting outbound peer %d -- headers chain has insufficient work\n", pfrom.GetId()); - pfrom.fDisconnect = true; - } - } - } - - // If this is an outbound full-relay peer, check to see if we should protect - // it from the bad/lagging chain logic. - // Note that outbound block-relay peers are excluded from this protection, and - // thus always subject to eviction under the bad/lagging chain logic. - // See ChainSyncTimeoutState. - if (!pfrom.fDisconnect && pfrom.IsFullOutboundConn() && nodestate->pindexBestKnownBlock != nullptr) { - if (m_outbound_peers_with_protect_from_disconnect < MAX_OUTBOUND_PEERS_TO_PROTECT_FROM_DISCONNECT && nodestate->pindexBestKnownBlock->nChainWork >= m_chainman.ActiveChain().Tip()->nChainWork && !nodestate->m_chain_sync.m_protect) { - LogPrint(BCLog::NET, "Protecting outbound peer=%d from eviction\n", pfrom.GetId()); - nodestate->m_chain_sync.m_protect = true; - ++m_outbound_peers_with_protect_from_disconnect; - } - } - } + UpdatePeerStateForReceivedHeaders(pfrom, pindexLast, received_new_header, nCount == MAX_HEADERS_RESULTS); // Consider immediately downloading blocks. HeadersDirectFetchBlocks(pfrom, pindexLast); -- cgit v1.2.3