diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/net_processing.cpp | 36 |
1 files changed, 27 insertions, 9 deletions
diff --git a/src/net_processing.cpp b/src/net_processing.cpp index 75e76d28cc..795851c491 100644 --- a/src/net_processing.cpp +++ b/src/net_processing.cpp @@ -567,6 +567,8 @@ private: void HandleFewUnconnectingHeaders(CNode& pfrom, Peer& peer, const std::vector<CBlockHeader>& headers); /** Return true if the headers connect to each other, false otherwise */ bool CheckHeadersAreContinuous(const std::vector<CBlockHeader>& headers) const; + /** Request further headers from this peer from a given block header */ + void FetchMoreHeaders(CNode& pfrom, const CBlockIndex *pindexLast, const Peer& peer); void SendBlockTransactions(CNode& pfrom, Peer& peer, const CBlock& block, const BlockTransactionsRequest& req); @@ -2255,6 +2257,25 @@ bool PeerManagerImpl::CheckHeadersAreContinuous(const std::vector<CBlockHeader>& return true; } +/* + * Continue fetching headers from a given point. + * pindexLast should be the last header we learned from a peer in their prior + * headers message. + * + * This is used for headers sync with a peer; even if pindexLast is an ancestor + * of a known chain (such as our tip) we don't yet know where the peer's chain + * might fork from what we know, so we continue exactly from where the peer + * left off. + */ +void PeerManagerImpl::FetchMoreHeaders(CNode& pfrom, const CBlockIndex *pindexLast, const Peer& peer) +{ + const CNetMsgMaker msgMaker(pfrom.GetCommonVersion()); + + LogPrint(BCLog::NET, "more getheaders (%d) to end to peer=%d (startheight:%d)\n", + pindexLast->nHeight, pfrom.GetId(), peer.m_starting_height); + m_connman.PushMessage(&pfrom, msgMaker.Make(NetMsgType::GETHEADERS, m_chainman.ActiveChain().GetLocator(pindexLast), uint256())); +} + void PeerManagerImpl::ProcessHeadersMessage(CNode& pfrom, Peer& peer, const std::vector<CBlockHeader>& headers, bool via_compact_block) @@ -2309,6 +2330,12 @@ void PeerManagerImpl::ProcessHeadersMessage(CNode& pfrom, Peer& peer, } } + // Consider fetching more headers. + if (nCount == MAX_HEADERS_RESULTS) { + // Headers message had its maximum size; the peer may have more headers. + FetchMoreHeaders(pfrom, pindexLast, peer); + } + { LOCK(cs_main); CNodeState *nodestate = State(pfrom.GetId()); @@ -2328,15 +2355,6 @@ void PeerManagerImpl::ProcessHeadersMessage(CNode& pfrom, Peer& peer, nodestate->m_last_block_announcement = GetTime(); } - if (nCount == MAX_HEADERS_RESULTS) { - // Headers message had its maximum size; the peer may have more headers. - // TODO: optimize: if pindexLast is an ancestor of m_chainman.ActiveChain().Tip or m_chainman.m_best_header, continue - // from there instead. - LogPrint(BCLog::NET, "more getheaders (%d) to end to peer=%d (startheight:%d)\n", - pindexLast->nHeight, pfrom.GetId(), peer.m_starting_height); - m_connman.PushMessage(&pfrom, msgMaker.Make(NetMsgType::GETHEADERS, m_chainman.ActiveChain().GetLocator(pindexLast), uint256())); - } - // 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) { |