diff options
Diffstat (limited to 'src/net_processing.cpp')
| -rw-r--r-- | src/net_processing.cpp | 892 |
1 files changed, 599 insertions, 293 deletions
diff --git a/src/net_processing.cpp b/src/net_processing.cpp index e09b56a631..dea4b042e6 100644 --- a/src/net_processing.cpp +++ b/src/net_processing.cpp @@ -23,6 +23,7 @@ #include "primitives/transaction.h" #include "random.h" #include "reverse_iterator.h" +#include "scheduler.h" #include "tinyformat.h" #include "txmempool.h" #include "ui_interface.h" @@ -116,6 +117,12 @@ namespace { /** Number of peers from which we're downloading blocks. */ int nPeersWithValidatedDownloads = 0; + /** Number of outbound peers with m_chain_sync.m_protect. */ + int g_outbound_peers_with_protect_from_disconnect = 0; + + /** When our tip was last updated. */ + int64_t g_last_tip_update = 0; + /** Relay map, protected by cs_main. */ typedef std::map<uint256, CTransactionRef> MapRelay; MapRelay mapRelay; @@ -123,11 +130,6 @@ namespace { std::deque<std::pair<int64_t, MapRelay::iterator>> vRelayExpiration; } // namespace -////////////////////////////////////////////////////////////////////////////// -// -// Registration of network node signals. -// - namespace { struct CBlockReject { @@ -198,6 +200,36 @@ struct CNodeState { */ bool fSupportsDesiredCmpctVersion; + /** State used to enforce CHAIN_SYNC_TIMEOUT + * Only in effect for outbound, non-manual connections, with + * m_protect == false + * Algorithm: if a peer's best known block has less work than our tip, + * set a timeout CHAIN_SYNC_TIMEOUT seconds in the future: + * - If at timeout their best known block now has more work than our tip + * when the timeout was set, then either reset the timeout or clear it + * (after comparing against our current tip's work) + * - If at timeout their best known block still has less work than our + * tip did when the timeout was set, then send a getheaders message, + * and set a shorter timeout, HEADERS_RESPONSE_TIME seconds in future. + * If their best known block is still behind when that new timeout is + * reached, disconnect. + */ + struct ChainSyncTimeoutState { + //! A timeout used for checking whether our peer has sufficiently synced + int64_t m_timeout; + //! A header with the work we require on our peer's chain + const CBlockIndex * m_work_header; + //! After timeout is reached, set to true after sending getheaders + bool m_sent_getheaders; + //! Whether this peer is protected from disconnection due to a bad/slow chain + bool m_protect; + }; + + ChainSyncTimeoutState m_chain_sync; + + //! Time of last new block announcement + int64_t m_last_block_announcement; + CNodeState(CAddress addrIn, std::string addrNameIn) : address(addrIn), name(addrNameIn) { fCurrentlyConnected = false; nMisbehavior = 0; @@ -220,6 +252,8 @@ struct CNodeState { fHaveWitness = false; fWantsCmpctWitness = false; fSupportsDesiredCmpctVersion = false; + m_chain_sync = { 0, nullptr, false, false }; + m_last_block_announcement = 0; } }; @@ -244,7 +278,7 @@ void UpdatePreferredDownload(CNode* node, CNodeState* state) nPreferredDownload += state->fPreferredDownload; } -void PushNodeVersion(CNode *pnode, CConnman& connman, int64_t nTime) +void PushNodeVersion(CNode *pnode, CConnman* connman, int64_t nTime) { ServiceFlags nLocalNodeServices = pnode->GetLocalServices(); uint64_t nonce = pnode->GetLocalNonce(); @@ -255,7 +289,7 @@ void PushNodeVersion(CNode *pnode, CConnman& connman, int64_t nTime) CAddress addrYou = (addr.IsRoutable() && !IsProxy(addr) ? addr : CAddress(CService(), addr.nServices)); CAddress addrMe = CAddress(CService(), nLocalNodeServices); - connman.PushMessage(pnode, CNetMsgMaker(INIT_PROTO_VERSION).Make(NetMsgType::VERSION, PROTOCOL_VERSION, (uint64_t)nLocalNodeServices, nTime, addrYou, addrMe, + connman->PushMessage(pnode, CNetMsgMaker(INIT_PROTO_VERSION).Make(NetMsgType::VERSION, PROTOCOL_VERSION, (uint64_t)nLocalNodeServices, nTime, addrYou, addrMe, nonce, strSubVersion, nNodeStartingHeight, ::fRelayTxes)); if (fLogIPs) { @@ -265,49 +299,6 @@ void PushNodeVersion(CNode *pnode, CConnman& connman, int64_t nTime) } } -void InitializeNode(CNode *pnode, CConnman& connman) { - CAddress addr = pnode->addr; - std::string addrName = pnode->GetAddrName(); - NodeId nodeid = pnode->GetId(); - { - LOCK(cs_main); - mapNodeState.emplace_hint(mapNodeState.end(), std::piecewise_construct, std::forward_as_tuple(nodeid), std::forward_as_tuple(addr, std::move(addrName))); - } - if(!pnode->fInbound) - PushNodeVersion(pnode, connman, GetTime()); -} - -void FinalizeNode(NodeId nodeid, bool& fUpdateConnectionTime) { - fUpdateConnectionTime = false; - LOCK(cs_main); - CNodeState *state = State(nodeid); - - if (state->fSyncStarted) - nSyncStarted--; - - if (state->nMisbehavior == 0 && state->fCurrentlyConnected) { - fUpdateConnectionTime = true; - } - - for (const QueuedBlock& entry : state->vBlocksInFlight) { - mapBlocksInFlight.erase(entry.hash); - } - EraseOrphansFor(nodeid); - nPreferredDownload -= state->fPreferredDownload; - nPeersWithValidatedDownloads -= (state->nBlocksInFlightValidHeaders != 0); - assert(nPeersWithValidatedDownloads >= 0); - - mapNodeState.erase(nodeid); - - if (mapNodeState.empty()) { - // Do a consistency check after the last peer is removed. - assert(mapBlocksInFlight.empty()); - assert(nPreferredDownload == 0); - assert(nPeersWithValidatedDownloads == 0); - } - LogPrint(BCLog::NET, "Cleared nodestate for peer=%d\n", nodeid); -} - // Requires cs_main. // Returns a bool indicating whether we requested this block. // Also used if a block was /not/ received and timed out or started with another peer @@ -402,7 +393,7 @@ void UpdateBlockAvailability(NodeId nodeid, const uint256 &hash) { } } -void MaybeSetPeerAsAnnouncingHeaderAndIDs(NodeId nodeid, CConnman& connman) { +void MaybeSetPeerAsAnnouncingHeaderAndIDs(NodeId nodeid, CConnman* connman) { AssertLockHeld(cs_main); CNodeState* nodestate = State(nodeid); if (!nodestate || !nodestate->fSupportsDesiredCmpctVersion) { @@ -417,26 +408,35 @@ void MaybeSetPeerAsAnnouncingHeaderAndIDs(NodeId nodeid, CConnman& connman) { return; } } - connman.ForNode(nodeid, [&connman](CNode* pfrom){ + connman->ForNode(nodeid, [connman](CNode* pfrom){ bool fAnnounceUsingCMPCTBLOCK = false; uint64_t nCMPCTBLOCKVersion = (pfrom->GetLocalServices() & NODE_WITNESS) ? 2 : 1; if (lNodesAnnouncingHeaderAndIDs.size() >= 3) { // As per BIP152, we only get 3 of our peers to announce // blocks using compact encodings. - connman.ForNode(lNodesAnnouncingHeaderAndIDs.front(), [&connman, fAnnounceUsingCMPCTBLOCK, nCMPCTBLOCKVersion](CNode* pnodeStop){ - connman.PushMessage(pnodeStop, CNetMsgMaker(pnodeStop->GetSendVersion()).Make(NetMsgType::SENDCMPCT, fAnnounceUsingCMPCTBLOCK, nCMPCTBLOCKVersion)); + connman->ForNode(lNodesAnnouncingHeaderAndIDs.front(), [connman, fAnnounceUsingCMPCTBLOCK, nCMPCTBLOCKVersion](CNode* pnodeStop){ + connman->PushMessage(pnodeStop, CNetMsgMaker(pnodeStop->GetSendVersion()).Make(NetMsgType::SENDCMPCT, fAnnounceUsingCMPCTBLOCK, nCMPCTBLOCKVersion)); return true; }); lNodesAnnouncingHeaderAndIDs.pop_front(); } fAnnounceUsingCMPCTBLOCK = true; - connman.PushMessage(pfrom, CNetMsgMaker(pfrom->GetSendVersion()).Make(NetMsgType::SENDCMPCT, fAnnounceUsingCMPCTBLOCK, nCMPCTBLOCKVersion)); + connman->PushMessage(pfrom, CNetMsgMaker(pfrom->GetSendVersion()).Make(NetMsgType::SENDCMPCT, fAnnounceUsingCMPCTBLOCK, nCMPCTBLOCKVersion)); lNodesAnnouncingHeaderAndIDs.push_back(pfrom->GetId()); return true; }); } } +bool TipMayBeStale(const Consensus::Params &consensusParams) +{ + AssertLockHeld(cs_main); + if (g_last_tip_update == 0) { + g_last_tip_update = GetTime(); + } + return g_last_tip_update < GetTime() - consensusParams.nPowTargetSpacing * 3 && mapBlocksInFlight.empty(); +} + // Requires cs_main bool CanDirectFetch(const Consensus::Params &consensusParams) { @@ -466,7 +466,7 @@ void FindNextBlocksToDownload(NodeId nodeid, unsigned int count, std::vector<con // Make sure pindexBestKnownBlock is up to date, we'll need it. ProcessBlockAvailability(nodeid); - if (state->pindexBestKnownBlock == nullptr || state->pindexBestKnownBlock->nChainWork < chainActive.Tip()->nChainWork || state->pindexBestKnownBlock->nChainWork < UintToArith256(consensusParams.nMinimumChainWork)) { + if (state->pindexBestKnownBlock == nullptr || state->pindexBestKnownBlock->nChainWork < chainActive.Tip()->nChainWork || state->pindexBestKnownBlock->nChainWork < nMinimumChainWork) { // This peer has nothing interesting. return; } @@ -543,6 +543,69 @@ void FindNextBlocksToDownload(NodeId nodeid, unsigned int count, std::vector<con } // namespace +// This function is used for testing the stale tip eviction logic, see +// DoS_tests.cpp +void UpdateLastBlockAnnounceTime(NodeId node, int64_t time_in_seconds) +{ + LOCK(cs_main); + CNodeState *state = State(node); + if (state) state->m_last_block_announcement = time_in_seconds; +} + +// Returns true for outbound peers, excluding manual connections, feelers, and +// one-shots +bool IsOutboundDisconnectionCandidate(const CNode *node) +{ + return !(node->fInbound || node->m_manual_connection || node->fFeeler || node->fOneShot); +} + +void PeerLogicValidation::InitializeNode(CNode *pnode) { + CAddress addr = pnode->addr; + std::string addrName = pnode->GetAddrName(); + NodeId nodeid = pnode->GetId(); + { + LOCK(cs_main); + mapNodeState.emplace_hint(mapNodeState.end(), std::piecewise_construct, std::forward_as_tuple(nodeid), std::forward_as_tuple(addr, std::move(addrName))); + } + if(!pnode->fInbound) + PushNodeVersion(pnode, connman, GetTime()); +} + +void PeerLogicValidation::FinalizeNode(NodeId nodeid, bool& fUpdateConnectionTime) { + fUpdateConnectionTime = false; + LOCK(cs_main); + CNodeState *state = State(nodeid); + assert(state != nullptr); + + if (state->fSyncStarted) + nSyncStarted--; + + if (state->nMisbehavior == 0 && state->fCurrentlyConnected) { + fUpdateConnectionTime = true; + } + + for (const QueuedBlock& entry : state->vBlocksInFlight) { + mapBlocksInFlight.erase(entry.hash); + } + EraseOrphansFor(nodeid); + nPreferredDownload -= state->fPreferredDownload; + nPeersWithValidatedDownloads -= (state->nBlocksInFlightValidHeaders != 0); + assert(nPeersWithValidatedDownloads >= 0); + g_outbound_peers_with_protect_from_disconnect -= state->m_chain_sync.m_protect; + assert(g_outbound_peers_with_protect_from_disconnect >= 0); + + mapNodeState.erase(nodeid); + + if (mapNodeState.empty()) { + // Do a consistency check after the last peer is removed. + assert(mapBlocksInFlight.empty()); + assert(nPreferredDownload == 0); + assert(nPeersWithValidatedDownloads == 0); + assert(g_outbound_peers_with_protect_from_disconnect == 0); + } + LogPrint(BCLog::NET, "Cleared nodestate for peer=%d\n", nodeid); +} + bool GetNodeStateStats(NodeId nodeid, CNodeStateStats &stats) { LOCK(cs_main); CNodeState *state = State(nodeid); @@ -558,22 +621,6 @@ bool GetNodeStateStats(NodeId nodeid, CNodeStateStats &stats) { return true; } -void RegisterNodeSignals(CNodeSignals& nodeSignals) -{ - nodeSignals.ProcessMessages.connect(&ProcessMessages); - nodeSignals.SendMessages.connect(&SendMessages); - nodeSignals.InitializeNode.connect(&InitializeNode); - nodeSignals.FinalizeNode.connect(&FinalizeNode); -} - -void UnregisterNodeSignals(CNodeSignals& nodeSignals) -{ - nodeSignals.ProcessMessages.disconnect(&ProcessMessages); - nodeSignals.SendMessages.disconnect(&SendMessages); - nodeSignals.InitializeNode.disconnect(&InitializeNode); - nodeSignals.FinalizeNode.disconnect(&FinalizeNode); -} - ////////////////////////////////////////////////////////////////////////////// // // mapOrphanTransactions @@ -725,9 +772,17 @@ void Misbehaving(NodeId pnode, int howmuch) // blockchain -> download logic notification // -PeerLogicValidation::PeerLogicValidation(CConnman* connmanIn) : connman(connmanIn) { +PeerLogicValidation::PeerLogicValidation(CConnman* connmanIn, CScheduler &scheduler) : connman(connmanIn), m_stale_tip_check_time(0) { // Initialize global variables that cannot be constructed at startup. recentRejects.reset(new CRollingBloomFilter(120000, 0.000001)); + + const Consensus::Params& consensusParams = Params().GetConsensus(); + // Stale tip checking and peer eviction are on two different timers, but we + // don't want them to get out of sync due to drift in the scheduler, so we + // combine them in one function and schedule at the quicker (peer-eviction) + // timer. + static_assert(EXTRA_PEER_CHECK_INTERVAL < STALE_CHECK_INTERVAL, "peer eviction timer should be less than stale tip check timer"); + scheduler.scheduleEvery(std::bind(&PeerLogicValidation::CheckForStaleTipAndEvictPeers, this, consensusParams), EXTRA_PEER_CHECK_INTERVAL * 1000); } void PeerLogicValidation::BlockConnected(const std::shared_ptr<const CBlock>& pblock, const CBlockIndex* pindex, const std::vector<CTransactionRef>& vtxConflicted) { @@ -758,6 +813,8 @@ void PeerLogicValidation::BlockConnected(const std::shared_ptr<const CBlock>& pb } LogPrint(BCLog::MEMPOOL, "Erased %d orphan tx included or conflicted by block\n", nErased); } + + g_last_tip_update = GetTime(); } // All of the following cache a recent block, and are protected by cs_most_recent_block @@ -865,7 +922,7 @@ void PeerLogicValidation::BlockChecked(const CBlock& block, const CValidationSta !IsInitialBlockDownload() && mapBlocksInFlight.count(hash) == mapBlocksInFlight.size()) { if (it != mapBlockSource.end()) { - MaybeSetPeerAsAnnouncingHeaderAndIDs(it->second.first, *connman); + MaybeSetPeerAsAnnouncingHeaderAndIDs(it->second.first, connman); } } if (it != mapBlockSource.end()) @@ -910,16 +967,16 @@ bool static AlreadyHave(const CInv& inv) EXCLUSIVE_LOCKS_REQUIRED(cs_main) return true; } -static void RelayTransaction(const CTransaction& tx, CConnman& connman) +static void RelayTransaction(const CTransaction& tx, CConnman* connman) { CInv inv(MSG_TX, tx.GetHash()); - connman.ForEachNode([&inv](CNode* pnode) + connman->ForEachNode([&inv](CNode* pnode) { pnode->PushInventory(inv); }); } -static void RelayAddress(const CAddress& addr, bool fReachable, CConnman& connman) +static void RelayAddress(const CAddress& addr, bool fReachable, CConnman* connman) { unsigned int nRelayNodes = fReachable ? 2 : 1; // limited relaying of addresses outside our network(s) @@ -927,7 +984,7 @@ static void RelayAddress(const CAddress& addr, bool fReachable, CConnman& connma // Use deterministic randomness to send to the same nodes for 24 hours // at a time so the addrKnowns of the chosen nodes prevent repeats uint64_t hashAddr = addr.GetHash(); - const CSipHasher hasher = connman.GetDeterministicRandomizer(RANDOMIZER_ID_ADDRESS_RELAY).Write(hashAddr << 32).Write((GetTime() + hashAddr) / (24*60*60)); + const CSipHasher hasher = connman->GetDeterministicRandomizer(RANDOMIZER_ID_ADDRESS_RELAY).Write(hashAddr << 32).Write((GetTime() + hashAddr) / (24*60*60)); FastRandomContext insecure_rand; std::array<std::pair<uint64_t, CNode*>,2> best{{{0, nullptr}, {0, nullptr}}}; @@ -952,10 +1009,10 @@ static void RelayAddress(const CAddress& addr, bool fReachable, CConnman& connma } }; - connman.ForEachNodeThen(std::move(sortfunc), std::move(pushfunc)); + connman->ForEachNodeThen(std::move(sortfunc), std::move(pushfunc)); } -void static ProcessGetData(CNode* pfrom, const Consensus::Params& consensusParams, CConnman& connman, const std::atomic<bool>& interruptMsgProc) +void static ProcessGetData(CNode* pfrom, const Consensus::Params& consensusParams, CConnman* connman, const std::atomic<bool>& interruptMsgProc) { std::deque<CInv>::iterator it = pfrom->vRecvGetData.begin(); std::vector<CInv> vNotFound; @@ -1017,7 +1074,7 @@ void static ProcessGetData(CNode* pfrom, const Consensus::Params& consensusParam // disconnect node in case we have reached the outbound limit for serving historical blocks // never disconnect whitelisted nodes static const int nOneWeek = 7 * 24 * 60 * 60; // assume > 1 week = historical - if (send && connman.OutboundTargetReached(true) && ( ((pindexBestHeader != nullptr) && (pindexBestHeader->GetBlockTime() - mi->second->GetBlockTime() > nOneWeek)) || inv.type == MSG_FILTERED_BLOCK) && !pfrom->fWhitelisted) + if (send && connman->OutboundTargetReached(true) && ( ((pindexBestHeader != nullptr) && (pindexBestHeader->GetBlockTime() - mi->second->GetBlockTime() > nOneWeek)) || inv.type == MSG_FILTERED_BLOCK) && !pfrom->fWhitelisted) { LogPrint(BCLog::NET, "historical block serving limit reached, disconnect peer=%d\n", pfrom->GetId()); @@ -1040,9 +1097,9 @@ void static ProcessGetData(CNode* pfrom, const Consensus::Params& consensusParam pblock = pblockRead; } if (inv.type == MSG_BLOCK) - connman.PushMessage(pfrom, msgMaker.Make(SERIALIZE_TRANSACTION_NO_WITNESS, NetMsgType::BLOCK, *pblock)); + connman->PushMessage(pfrom, msgMaker.Make(SERIALIZE_TRANSACTION_NO_WITNESS, NetMsgType::BLOCK, *pblock)); else if (inv.type == MSG_WITNESS_BLOCK) - connman.PushMessage(pfrom, msgMaker.Make(NetMsgType::BLOCK, *pblock)); + connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::BLOCK, *pblock)); else if (inv.type == MSG_FILTERED_BLOCK) { bool sendMerkleBlock = false; @@ -1055,7 +1112,7 @@ void static ProcessGetData(CNode* pfrom, const Consensus::Params& consensusParam } } if (sendMerkleBlock) { - connman.PushMessage(pfrom, msgMaker.Make(NetMsgType::MERKLEBLOCK, merkleBlock)); + connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::MERKLEBLOCK, merkleBlock)); // CMerkleBlock just contains hashes, so also push any transactions in the block the client did not see // This avoids hurting performance by pointlessly requiring a round-trip // Note that there is currently no way for a node to request any single transactions we didn't send here - @@ -1064,7 +1121,7 @@ void static ProcessGetData(CNode* pfrom, const Consensus::Params& consensusParam // however we MUST always provide at least what the remote peer needs typedef std::pair<unsigned int, uint256> PairType; for (PairType& pair : merkleBlock.vMatchedTxn) - connman.PushMessage(pfrom, msgMaker.Make(SERIALIZE_TRANSACTION_NO_WITNESS, NetMsgType::TX, *pblock->vtx[pair.first])); + connman->PushMessage(pfrom, msgMaker.Make(SERIALIZE_TRANSACTION_NO_WITNESS, NetMsgType::TX, *pblock->vtx[pair.first])); } // else // no response @@ -1079,13 +1136,13 @@ void static ProcessGetData(CNode* pfrom, const Consensus::Params& consensusParam int nSendFlags = fPeerWantsWitness ? 0 : SERIALIZE_TRANSACTION_NO_WITNESS; if (CanDirectFetch(consensusParams) && mi->second->nHeight >= chainActive.Height() - MAX_CMPCTBLOCK_DEPTH) { if ((fPeerWantsWitness || !fWitnessesPresentInARecentCompactBlock) && a_recent_compact_block && a_recent_compact_block->header.GetHash() == mi->second->GetBlockHash()) { - connman.PushMessage(pfrom, msgMaker.Make(nSendFlags, NetMsgType::CMPCTBLOCK, *a_recent_compact_block)); + connman->PushMessage(pfrom, msgMaker.Make(nSendFlags, NetMsgType::CMPCTBLOCK, *a_recent_compact_block)); } else { CBlockHeaderAndShortTxIDs cmpctblock(*pblock, fPeerWantsWitness); - connman.PushMessage(pfrom, msgMaker.Make(nSendFlags, NetMsgType::CMPCTBLOCK, cmpctblock)); + connman->PushMessage(pfrom, msgMaker.Make(nSendFlags, NetMsgType::CMPCTBLOCK, cmpctblock)); } } else { - connman.PushMessage(pfrom, msgMaker.Make(nSendFlags, NetMsgType::BLOCK, *pblock)); + connman->PushMessage(pfrom, msgMaker.Make(nSendFlags, NetMsgType::BLOCK, *pblock)); } } @@ -1097,7 +1154,7 @@ void static ProcessGetData(CNode* pfrom, const Consensus::Params& consensusParam // wait for other stuff first. std::vector<CInv> vInv; vInv.push_back(CInv(MSG_BLOCK, chainActive.Tip()->GetBlockHash())); - connman.PushMessage(pfrom, msgMaker.Make(NetMsgType::INV, vInv)); + connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::INV, vInv)); pfrom->hashContinue.SetNull(); } } @@ -1109,14 +1166,14 @@ void static ProcessGetData(CNode* pfrom, const Consensus::Params& consensusParam auto mi = mapRelay.find(inv.hash); int nSendFlags = (inv.type == MSG_TX ? SERIALIZE_TRANSACTION_NO_WITNESS : 0); if (mi != mapRelay.end()) { - connman.PushMessage(pfrom, msgMaker.Make(nSendFlags, NetMsgType::TX, *mi->second)); + connman->PushMessage(pfrom, msgMaker.Make(nSendFlags, NetMsgType::TX, *mi->second)); push = true; } else if (pfrom->timeLastMempoolReq) { auto txinfo = mempool.info(inv.hash); // To protect privacy, do not answer getdata using the mempool when // that TX couldn't have been INVed in reply to a MEMPOOL request. if (txinfo.tx && txinfo.nTime <= pfrom->timeLastMempoolReq) { - connman.PushMessage(pfrom, msgMaker.Make(nSendFlags, NetMsgType::TX, *txinfo.tx)); + connman->PushMessage(pfrom, msgMaker.Make(nSendFlags, NetMsgType::TX, *txinfo.tx)); push = true; } } @@ -1143,7 +1200,7 @@ void static ProcessGetData(CNode* pfrom, const Consensus::Params& consensusParam // do that because they want to know about (and store and rebroadcast and // risk analyze) the dependencies of transactions relevant to them, without // having to download the entire memory pool. - connman.PushMessage(pfrom, msgMaker.Make(NetMsgType::NOTFOUND, vNotFound)); + connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::NOTFOUND, vNotFound)); } } @@ -1155,7 +1212,7 @@ uint32_t GetFetchFlags(CNode* pfrom) { return nFetchFlags; } -inline void static SendBlockTransactions(const CBlock& block, const BlockTransactionsRequest& req, CNode* pfrom, CConnman& connman) { +inline void static SendBlockTransactions(const CBlock& block, const BlockTransactionsRequest& req, CNode* pfrom, CConnman* connman) { BlockTransactions resp(req); for (size_t i = 0; i < req.indexes.size(); i++) { if (req.indexes[i] >= block.vtx.size()) { @@ -1169,10 +1226,229 @@ inline void static SendBlockTransactions(const CBlock& block, const BlockTransac LOCK(cs_main); const CNetMsgMaker msgMaker(pfrom->GetSendVersion()); int nSendFlags = State(pfrom->GetId())->fWantsCmpctWitness ? 0 : SERIALIZE_TRANSACTION_NO_WITNESS; - connman.PushMessage(pfrom, msgMaker.Make(nSendFlags, NetMsgType::BLOCKTXN, resp)); + connman->PushMessage(pfrom, msgMaker.Make(nSendFlags, NetMsgType::BLOCKTXN, resp)); } -bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStream& vRecv, int64_t nTimeReceived, const CChainParams& chainparams, CConnman& connman, const std::atomic<bool>& interruptMsgProc) +bool static ProcessHeadersMessage(CNode *pfrom, CConnman *connman, const std::vector<CBlockHeader>& headers, const CChainParams& chainparams, bool punish_duplicate_invalid) +{ + const CNetMsgMaker msgMaker(pfrom->GetSendVersion()); + size_t nCount = headers.size(); + + if (nCount == 0) { + // Nothing interesting. Stop asking this peers for more headers. + return true; + } + + bool received_new_header = false; + const CBlockIndex *pindexLast = nullptr; + { + LOCK(cs_main); + CNodeState *nodestate = State(pfrom->GetId()); + + // If this looks like it could be a block announcement (nCount < + // MAX_BLOCKS_TO_ANNOUNCE), use special logic for handling headers that + // don't connect: + // - Send a getheaders message in response to try to connect the chain. + // - The peer can send up to MAX_UNCONNECTING_HEADERS in a row that + // don't connect before giving DoS points + // - Once a headers message is received that is valid and does connect, + // nUnconnectingHeaders gets reset back to 0. + if (mapBlockIndex.find(headers[0].hashPrevBlock) == mapBlockIndex.end() && nCount < MAX_BLOCKS_TO_ANNOUNCE) { + nodestate->nUnconnectingHeaders++; + connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::GETHEADERS, chainActive.GetLocator(pindexBestHeader), uint256())); + LogPrint(BCLog::NET, "received header %s: missing prev block %s, sending getheaders (%d) to end (peer=%d, nUnconnectingHeaders=%d)\n", + headers[0].GetHash().ToString(), + headers[0].hashPrevBlock.ToString(), + pindexBestHeader->nHeight, + pfrom->GetId(), nodestate->nUnconnectingHeaders); + // Set hashLastUnknownBlock for this peer, so that if we + // eventually get the headers - even from a different peer - + // we can use this peer to download. + UpdateBlockAvailability(pfrom->GetId(), headers.back().GetHash()); + + if (nodestate->nUnconnectingHeaders % MAX_UNCONNECTING_HEADERS == 0) { + Misbehaving(pfrom->GetId(), 20); + } + return true; + } + + uint256 hashLastBlock; + for (const CBlockHeader& header : headers) { + if (!hashLastBlock.IsNull() && header.hashPrevBlock != hashLastBlock) { + Misbehaving(pfrom->GetId(), 20); + return error("non-continuous headers sequence"); + } + hashLastBlock = header.GetHash(); + } + + // If we don't have the last header, then they'll have given us + // something new (if these headers are valid). + if (mapBlockIndex.find(hashLastBlock) == mapBlockIndex.end()) { + received_new_header = true; + } + } + + CValidationState state; + CBlockHeader first_invalid_header; + if (!ProcessNewBlockHeaders(headers, state, chainparams, &pindexLast, &first_invalid_header)) { + int nDoS; + if (state.IsInvalid(nDoS)) { + LOCK(cs_main); + if (nDoS > 0) { + Misbehaving(pfrom->GetId(), nDoS); + } + if (punish_duplicate_invalid && mapBlockIndex.find(first_invalid_header.GetHash()) != mapBlockIndex.end()) { + // Goal: don't allow outbound peers to use up our outbound + // connection slots if they are on incompatible chains. + // + // We ask the caller to set punish_invalid appropriately based + // on the peer and the method of header delivery (compact + // blocks are allowed to be invalid in some circumstances, + // under BIP 152). + // Here, we try to detect the narrow situation that we have a + // valid block header (ie it was valid at the time the header + // was received, and hence stored in mapBlockIndex) but know the + // block is invalid, and that a peer has announced that same + // block as being on its active chain. + // Disconnect the peer in such a situation. + // + // Note: if the header that is invalid was not accepted to our + // mapBlockIndex at all, that may also be grounds for + // disconnecting the peer, as the chain they are on is likely + // to be incompatible. However, there is a circumstance where + // that does not hold: if the header's timestamp is more than + // 2 hours ahead of our current time. In that case, the header + // may become valid in the future, and we don't want to + // disconnect a peer merely for serving us one too-far-ahead + // block header, to prevent an attacker from splitting the + // network by mining a block right at the 2 hour boundary. + // + // TODO: update the DoS logic (or, rather, rewrite the + // DoS-interface between validation and net_processing) so that + // the interface is cleaner, and so that we disconnect on all the + // reasons that a peer's headers chain is incompatible + // with ours (eg block->nVersion softforks, MTP violations, + // etc), and not just the duplicate-invalid case. + pfrom->fDisconnect = true; + } + return error("invalid header received"); + } + } + + { + 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 > chainActive.Tip()->nChainWork) { + 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 chainActive.Tip or pindexBestHeader, continue + // from there instead. + LogPrint(BCLog::NET, "more getheaders (%d) to end to peer=%d (startheight:%d)\n", pindexLast->nHeight, pfrom->GetId(), pfrom->nStartingHeight); + connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::GETHEADERS, chainActive.GetLocator(pindexLast), uint256())); + } + + bool fCanDirectFetch = CanDirectFetch(chainparams.GetConsensus()); + // 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 (fCanDirectFetch && pindexLast->IsValid(BLOCK_VALID_TREE) && chainActive.Tip()->nChainWork <= pindexLast->nChainWork) { + std::vector<const CBlockIndex*> vToFetch; + const CBlockIndex *pindexWalk = pindexLast; + // Calculate all the blocks we'd need to switch to pindexLast, up to a limit. + while (pindexWalk && !chainActive.Contains(pindexWalk) && vToFetch.size() <= MAX_BLOCKS_IN_TRANSIT_PER_PEER) { + if (!(pindexWalk->nStatus & BLOCK_HAVE_DATA) && + !mapBlocksInFlight.count(pindexWalk->GetBlockHash()) && + (!IsWitnessEnabled(pindexWalk->pprev, chainparams.GetConsensus()) || 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 (!chainActive.Contains(pindexWalk)) { + LogPrint(BCLog::NET, "Large reorg, won't direct fetch to %s (%d)\n", + pindexLast->GetBlockHash().ToString(), + pindexLast->nHeight); + } else { + std::vector<CInv> 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())); + MarkBlockAsInFlight(pfrom->GetId(), pindex->GetBlockHash(), 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 (nodestate->fSupportsDesiredCmpctVersion && 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); + } + connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::GETDATA, vGetData)); + } + } + } + // 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 (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 using an outbound slot (unless + // whitelisted or addnode). + // Note: We compare their tip to nMinimumChainWork (rather than + // chainActive.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 (IsOutboundDisconnectionCandidate(pfrom)) { + LogPrintf("Disconnecting outbound peer %d -- headers chain has insufficient work\n", pfrom->GetId()); + pfrom->fDisconnect = true; + } + } + } + + if (!pfrom->fDisconnect && IsOutboundDisconnectionCandidate(pfrom) && nodestate->pindexBestKnownBlock != nullptr) { + // If this is an outbound peer, check to see if we should protect + // it from the bad/lagging chain logic. + if (g_outbound_peers_with_protect_from_disconnect < MAX_OUTBOUND_PEERS_TO_PROTECT_FROM_DISCONNECT && nodestate->pindexBestKnownBlock->nChainWork >= chainActive.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; + ++g_outbound_peers_with_protect_from_disconnect; + } + } + } + + return true; +} + +bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStream& vRecv, int64_t nTimeReceived, const CChainParams& chainparams, CConnman* connman, const std::atomic<bool>& interruptMsgProc) { LogPrint(BCLog::NET, "received: %s (%u bytes) peer=%d\n", SanitizeString(strCommand), vRecv.size(), pfrom->GetId()); if (gArgs.IsArgSet("-dropmessagestest") && GetRand(gArgs.GetArg("-dropmessagestest", 0)) == 0) @@ -1225,7 +1501,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr // Each connection can only send one version message if (pfrom->nVersion != 0) { - connman.PushMessage(pfrom, CNetMsgMaker(INIT_PROTO_VERSION).Make(NetMsgType::REJECT, strCommand, REJECT_DUPLICATE, std::string("Duplicate version message"))); + connman->PushMessage(pfrom, CNetMsgMaker(INIT_PROTO_VERSION).Make(NetMsgType::REJECT, strCommand, REJECT_DUPLICATE, std::string("Duplicate version message"))); LOCK(cs_main); Misbehaving(pfrom->GetId(), 1); return false; @@ -1249,12 +1525,12 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr nServices = ServiceFlags(nServiceInt); if (!pfrom->fInbound) { - connman.SetServices(pfrom->addr, nServices); + connman->SetServices(pfrom->addr, nServices); } if (pfrom->nServicesExpected & ~nServices) { LogPrint(BCLog::NET, "peer=%d does not offer the expected services (%08x offered, %08x expected); disconnecting\n", pfrom->GetId(), nServices, pfrom->nServicesExpected); - connman.PushMessage(pfrom, CNetMsgMaker(INIT_PROTO_VERSION).Make(NetMsgType::REJECT, strCommand, REJECT_NONSTANDARD, + connman->PushMessage(pfrom, CNetMsgMaker(INIT_PROTO_VERSION).Make(NetMsgType::REJECT, strCommand, REJECT_NONSTANDARD, strprintf("Expected to offer services %08x", pfrom->nServicesExpected))); pfrom->fDisconnect = true; return false; @@ -1275,7 +1551,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr { // disconnect from peers older than this proto version LogPrintf("peer=%d using obsolete version %i; disconnecting\n", pfrom->GetId(), nVersion); - connman.PushMessage(pfrom, CNetMsgMaker(INIT_PROTO_VERSION).Make(NetMsgType::REJECT, strCommand, REJECT_OBSOLETE, + connman->PushMessage(pfrom, CNetMsgMaker(INIT_PROTO_VERSION).Make(NetMsgType::REJECT, strCommand, REJECT_OBSOLETE, strprintf("Version must be %d or greater", MIN_PEER_PROTO_VERSION))); pfrom->fDisconnect = true; return false; @@ -1295,7 +1571,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr if (!vRecv.empty()) vRecv >> fRelay; // Disconnect if we connected to ourself - if (pfrom->fInbound && !connman.CheckIncomingNonce(nNonce)) + if (pfrom->fInbound && !connman->CheckIncomingNonce(nNonce)) { LogPrintf("connected to self at %s, disconnecting\n", pfrom->addr.ToString()); pfrom->fDisconnect = true; @@ -1311,7 +1587,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr if (pfrom->fInbound) PushNodeVersion(pfrom, connman, GetAdjustedTime()); - connman.PushMessage(pfrom, CNetMsgMaker(INIT_PROTO_VERSION).Make(NetMsgType::VERACK)); + connman->PushMessage(pfrom, CNetMsgMaker(INIT_PROTO_VERSION).Make(NetMsgType::VERACK)); pfrom->nServices = nServices; pfrom->SetAddrLocal(addrMe); @@ -1362,12 +1638,12 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr } // Get recent addresses - if (pfrom->fOneShot || pfrom->nVersion >= CADDR_TIME_VERSION || connman.GetAddressCount() < 1000) + if (pfrom->fOneShot || pfrom->nVersion >= CADDR_TIME_VERSION || connman->GetAddressCount() < 1000) { - connman.PushMessage(pfrom, CNetMsgMaker(nSendVersion).Make(NetMsgType::GETADDR)); + connman->PushMessage(pfrom, CNetMsgMaker(nSendVersion).Make(NetMsgType::GETADDR)); pfrom->fGetAddr = true; } - connman.MarkAddressGood(pfrom->addr); + connman->MarkAddressGood(pfrom->addr); } std::string remoteAddr; @@ -1386,7 +1662,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr // If the peer is old enough to have the old alert system, send it the final alert. if (pfrom->nVersion <= 70012) { CDataStream finalAlert(ParseHex("60010000000000000000000000ffffff7f00000000ffffff7ffeffff7f01ffffff7f00000000ffffff7f00ffffff7f002f555247454e543a20416c657274206b657920636f6d70726f6d697365642c2075706772616465207265717569726564004630440220653febd6410f470f6bae11cad19c48413becb1ac2c17f908fd0fd53bdc3abd5202206d0e9c96fe88d4a0f01ed9dedae2b6f9e00da94cad0fecaae66ecf689bf71b50"), SER_NETWORK, PROTOCOL_VERSION); - connman.PushMessage(pfrom, CNetMsgMaker(nSendVersion).Make("alert", finalAlert)); + connman->PushMessage(pfrom, CNetMsgMaker(nSendVersion).Make("alert", finalAlert)); } // Feeler connections exist only to verify if address is online. @@ -1424,7 +1700,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr // We send this to non-NODE NETWORK peers as well, because even // non-NODE NETWORK peers can announce blocks (such as pruning // nodes) - connman.PushMessage(pfrom, msgMaker.Make(NetMsgType::SENDHEADERS)); + connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::SENDHEADERS)); } if (pfrom->nVersion >= SHORT_IDS_BLOCKS_VERSION) { // Tell our peer we are willing to provide version 1 or 2 cmpctblocks @@ -1435,9 +1711,9 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr bool fAnnounceUsingCMPCTBLOCK = false; uint64_t nCMPCTBLOCKVersion = 2; if (pfrom->GetLocalServices() & NODE_WITNESS) - connman.PushMessage(pfrom, msgMaker.Make(NetMsgType::SENDCMPCT, fAnnounceUsingCMPCTBLOCK, nCMPCTBLOCKVersion)); + connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::SENDCMPCT, fAnnounceUsingCMPCTBLOCK, nCMPCTBLOCKVersion)); nCMPCTBLOCKVersion = 1; - connman.PushMessage(pfrom, msgMaker.Make(NetMsgType::SENDCMPCT, fAnnounceUsingCMPCTBLOCK, nCMPCTBLOCKVersion)); + connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::SENDCMPCT, fAnnounceUsingCMPCTBLOCK, nCMPCTBLOCKVersion)); } pfrom->fSuccessfullyConnected = true; } @@ -1456,7 +1732,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr vRecv >> vAddr; // Don't want addr from older versions unless seeding - if (pfrom->nVersion < CADDR_TIME_VERSION && connman.GetAddressCount() > 1000) + if (pfrom->nVersion < CADDR_TIME_VERSION && connman->GetAddressCount() > 1000) return true; if (vAddr.size() > 1000) { @@ -1490,7 +1766,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr if (fReachable) vAddrOk.push_back(addr); } - connman.AddNewAddresses(vAddrOk, pfrom->addr, 2 * 60 * 60); + connman->AddNewAddresses(vAddrOk, pfrom->addr, 2 * 60 * 60); if (vAddr.size() < 1000) pfrom->fGetAddr = false; if (pfrom->fOneShot) @@ -1568,7 +1844,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr // fell back to inv we probably have a reorg which we should get the headers for first, // we now only provide a getheaders response here. When we receive the headers, we will // then ask for the blocks we need. - connman.PushMessage(pfrom, msgMaker.Make(NetMsgType::GETHEADERS, chainActive.GetLocator(pindexBestHeader), inv.hash)); + connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::GETHEADERS, chainActive.GetLocator(pindexBestHeader), inv.hash)); LogPrint(BCLog::NET, "getheaders (%d) %s to peer=%d\n", pindexBestHeader->nHeight, inv.hash.ToString(), pfrom->GetId()); } } @@ -1774,7 +2050,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr // will re-announce the new block via headers (or compact blocks again) // in the SendMessages logic. nodestate->pindexBestHeaderSent = pindex ? pindex : chainActive.Tip(); - connman.PushMessage(pfrom, msgMaker.Make(NetMsgType::HEADERS, vHeaders)); + connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::HEADERS, vHeaders)); } @@ -1955,7 +2231,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr pfrom->GetId(), FormatStateMessage(state)); if (state.GetRejectCode() > 0 && state.GetRejectCode() < REJECT_INTERNAL) // Never send AcceptToMemoryPool's internal codes over P2P - connman.PushMessage(pfrom, msgMaker.Make(NetMsgType::REJECT, strCommand, (unsigned char)state.GetRejectCode(), + connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::REJECT, strCommand, (unsigned char)state.GetRejectCode(), state.GetRejectReason().substr(0, MAX_REJECT_MESSAGE_LENGTH), inv.hash)); if (nDoS > 0) { Misbehaving(pfrom->GetId(), nDoS); @@ -1969,15 +2245,21 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr CBlockHeaderAndShortTxIDs cmpctblock; vRecv >> cmpctblock; + bool received_new_header = false; + { LOCK(cs_main); if (mapBlockIndex.find(cmpctblock.header.hashPrevBlock) == mapBlockIndex.end()) { // Doesn't connect (or is genesis), instead of DoSing in AcceptBlockHeader, request deeper headers if (!IsInitialBlockDownload()) - connman.PushMessage(pfrom, msgMaker.Make(NetMsgType::GETHEADERS, chainActive.GetLocator(pindexBestHeader), uint256())); + connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::GETHEADERS, chainActive.GetLocator(pindexBestHeader), uint256())); return true; } + + if (mapBlockIndex.find(cmpctblock.header.GetHash()) == mapBlockIndex.end()) { + received_new_header = true; + } } const CBlockIndex *pindex = nullptr; @@ -2004,7 +2286,6 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr // If we end up treating this as a plain headers message, call that as well // without cs_main. bool fRevertToHeaderProcessing = false; - CDataStream vHeadersMsg(SER_NETWORK, PROTOCOL_VERSION); // Keep a CBlock for "optimistic" compactblock reconstructions (see // below) @@ -2017,6 +2298,14 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr assert(pindex); UpdateBlockAvailability(pfrom->GetId(), pindex->GetBlockHash()); + CNodeState *nodestate = State(pfrom->GetId()); + + // If this was a new header with more work than our tip, update the + // peer's last block announcement time + if (received_new_header && pindex->nChainWork > chainActive.Tip()->nChainWork) { + nodestate->m_last_block_announcement = GetTime(); + } + std::map<uint256, std::pair<NodeId, std::list<QueuedBlock>::iterator> >::iterator blockInFlightIt = mapBlocksInFlight.find(pindex->GetBlockHash()); bool fAlreadyInFlight = blockInFlightIt != mapBlocksInFlight.end(); @@ -2030,7 +2319,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr // so we just grab the block via normal getdata std::vector<CInv> vInv(1); vInv[0] = CInv(MSG_BLOCK | GetFetchFlags(pfrom), cmpctblock.header.GetHash()); - connman.PushMessage(pfrom, msgMaker.Make(NetMsgType::GETDATA, vInv)); + connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::GETDATA, vInv)); } return true; } @@ -2039,8 +2328,6 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr if (!fAlreadyInFlight && !CanDirectFetch(chainparams.GetConsensus())) return true; - CNodeState *nodestate = State(pfrom->GetId()); - if (IsWitnessEnabled(pindex->pprev, chainparams.GetConsensus()) && !nodestate->fSupportsDesiredCmpctVersion) { // Don't bother trying to process compact blocks from v1 peers // after segwit activates. @@ -2074,7 +2361,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr // Duplicate txindexes, the block is now in-flight, so just request it std::vector<CInv> vInv(1); vInv[0] = CInv(MSG_BLOCK | GetFetchFlags(pfrom), cmpctblock.header.GetHash()); - connman.PushMessage(pfrom, msgMaker.Make(NetMsgType::GETDATA, vInv)); + connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::GETDATA, vInv)); return true; } @@ -2091,7 +2378,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr fProcessBLOCKTXN = true; } else { req.blockhash = pindex->GetBlockHash(); - connman.PushMessage(pfrom, msgMaker.Make(NetMsgType::GETBLOCKTXN, req)); + connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::GETBLOCKTXN, req)); } } else { // This block is either already in flight from a different @@ -2117,14 +2404,10 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr // mempool will probably be useless - request the block normally std::vector<CInv> vInv(1); vInv[0] = CInv(MSG_BLOCK | GetFetchFlags(pfrom), cmpctblock.header.GetHash()); - connman.PushMessage(pfrom, msgMaker.Make(NetMsgType::GETDATA, vInv)); + connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::GETDATA, vInv)); return true; } else { // If this was an announce-cmpctblock, we want the same treatment as a header message - // Dirty hack to process as if it were just a headers message (TODO: move message handling into their own functions) - std::vector<CBlock> headers; - headers.push_back(cmpctblock.header); - vHeadersMsg << headers; fRevertToHeaderProcessing = true; } } @@ -2133,8 +2416,14 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr if (fProcessBLOCKTXN) return ProcessMessage(pfrom, NetMsgType::BLOCKTXN, blockTxnMsg, nTimeReceived, chainparams, connman, interruptMsgProc); - if (fRevertToHeaderProcessing) - return ProcessMessage(pfrom, NetMsgType::HEADERS, vHeadersMsg, nTimeReceived, chainparams, connman, interruptMsgProc); + if (fRevertToHeaderProcessing) { + // Headers received from HB compact block peers are permitted to be + // relayed before full validation (see BIP 152), so we don't want to disconnect + // the peer if the header turns out to be for an invalid block. + // Note that if a peer tries to build on an invalid chain, that + // will be detected and the peer will be banned. + return ProcessHeadersMessage(pfrom, connman, {cmpctblock.header}, chainparams, /*punish_duplicate_invalid=*/false); + } if (fBlockReconstructed) { // If we got here, we were able to optimistically reconstruct a @@ -2144,7 +2433,16 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr mapBlockSource.emplace(pblock->GetHash(), std::make_pair(pfrom->GetId(), false)); } bool fNewBlock = false; - ProcessNewBlock(chainparams, pblock, true, &fNewBlock); + // Setting fForceProcessing to true means that we bypass some of + // our anti-DoS protections in AcceptBlock, which filters + // unrequested blocks that might be trying to waste our resources + // (eg disk space). Because we only try to reconstruct blocks when + // we're close to caught up (via the CanDirectFetch() requirement + // above, combined with the behavior of not requesting blocks until + // we have a chain with at least nMinimumChainWork), and we ignore + // compact blocks with less work than our tip, it is safe to treat + // reconstructed compact blocks as having been requested. + ProcessNewBlock(chainparams, pblock, /*fForceProcessing=*/true, &fNewBlock); if (fNewBlock) { pfrom->nLastBlockTime = GetTime(); } else { @@ -2191,7 +2489,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr // Might have collided, fall back to getdata now :( std::vector<CInv> invs; invs.push_back(CInv(MSG_BLOCK | GetFetchFlags(pfrom), resp.blockhash)); - connman.PushMessage(pfrom, msgMaker.Make(NetMsgType::GETDATA, invs)); + connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::GETDATA, invs)); } else { // Block is either okay, or possibly we received // READ_STATUS_CHECKBLOCK_FAILED. @@ -2224,7 +2522,11 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr bool fNewBlock = false; // Since we requested this block (it was in mapBlocksInFlight), force it to be processed, // even if it would not be a candidate for new tip (missing previous block, chain not long enough, etc) - ProcessNewBlock(chainparams, pblock, true, &fNewBlock); + // This bypasses some anti-DoS logic in AcceptBlock (eg to prevent + // disk-space attacks), but this should be safe due to the + // protections in the compact block handler -- see related comment + // in compact block optimistic reconstruction handling. + ProcessNewBlock(chainparams, pblock, /*fForceProcessing=*/true, &fNewBlock); if (fNewBlock) { pfrom->nLastBlockTime = GetTime(); } else { @@ -2252,136 +2554,12 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr ReadCompactSize(vRecv); // ignore tx count; assume it is 0. } - if (nCount == 0) { - // Nothing interesting. Stop asking this peers for more headers. - return true; - } - - const CBlockIndex *pindexLast = nullptr; - { - LOCK(cs_main); - CNodeState *nodestate = State(pfrom->GetId()); - - // If this looks like it could be a block announcement (nCount < - // MAX_BLOCKS_TO_ANNOUNCE), use special logic for handling headers that - // don't connect: - // - Send a getheaders message in response to try to connect the chain. - // - The peer can send up to MAX_UNCONNECTING_HEADERS in a row that - // don't connect before giving DoS points - // - Once a headers message is received that is valid and does connect, - // nUnconnectingHeaders gets reset back to 0. - if (mapBlockIndex.find(headers[0].hashPrevBlock) == mapBlockIndex.end() && nCount < MAX_BLOCKS_TO_ANNOUNCE) { - nodestate->nUnconnectingHeaders++; - connman.PushMessage(pfrom, msgMaker.Make(NetMsgType::GETHEADERS, chainActive.GetLocator(pindexBestHeader), uint256())); - LogPrint(BCLog::NET, "received header %s: missing prev block %s, sending getheaders (%d) to end (peer=%d, nUnconnectingHeaders=%d)\n", - headers[0].GetHash().ToString(), - headers[0].hashPrevBlock.ToString(), - pindexBestHeader->nHeight, - pfrom->GetId(), nodestate->nUnconnectingHeaders); - // Set hashLastUnknownBlock for this peer, so that if we - // eventually get the headers - even from a different peer - - // we can use this peer to download. - UpdateBlockAvailability(pfrom->GetId(), headers.back().GetHash()); - - if (nodestate->nUnconnectingHeaders % MAX_UNCONNECTING_HEADERS == 0) { - Misbehaving(pfrom->GetId(), 20); - } - return true; - } - - uint256 hashLastBlock; - for (const CBlockHeader& header : headers) { - if (!hashLastBlock.IsNull() && header.hashPrevBlock != hashLastBlock) { - Misbehaving(pfrom->GetId(), 20); - return error("non-continuous headers sequence"); - } - hashLastBlock = header.GetHash(); - } - } - - CValidationState state; - if (!ProcessNewBlockHeaders(headers, state, chainparams, &pindexLast)) { - int nDoS; - if (state.IsInvalid(nDoS)) { - if (nDoS > 0) { - LOCK(cs_main); - Misbehaving(pfrom->GetId(), nDoS); - } - return error("invalid header received"); - } - } - - { - 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()); - - 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 chainActive.Tip or pindexBestHeader, continue - // from there instead. - LogPrint(BCLog::NET, "more getheaders (%d) to end to peer=%d (startheight:%d)\n", pindexLast->nHeight, pfrom->GetId(), pfrom->nStartingHeight); - connman.PushMessage(pfrom, msgMaker.Make(NetMsgType::GETHEADERS, chainActive.GetLocator(pindexLast), uint256())); - } - - bool fCanDirectFetch = CanDirectFetch(chainparams.GetConsensus()); - // 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 (fCanDirectFetch && pindexLast->IsValid(BLOCK_VALID_TREE) && chainActive.Tip()->nChainWork <= pindexLast->nChainWork) { - std::vector<const CBlockIndex*> vToFetch; - const CBlockIndex *pindexWalk = pindexLast; - // Calculate all the blocks we'd need to switch to pindexLast, up to a limit. - while (pindexWalk && !chainActive.Contains(pindexWalk) && vToFetch.size() <= MAX_BLOCKS_IN_TRANSIT_PER_PEER) { - if (!(pindexWalk->nStatus & BLOCK_HAVE_DATA) && - !mapBlocksInFlight.count(pindexWalk->GetBlockHash()) && - (!IsWitnessEnabled(pindexWalk->pprev, chainparams.GetConsensus()) || 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 (!chainActive.Contains(pindexWalk)) { - LogPrint(BCLog::NET, "Large reorg, won't direct fetch to %s (%d)\n", - pindexLast->GetBlockHash().ToString(), - pindexLast->nHeight); - } else { - std::vector<CInv> 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())); - MarkBlockAsInFlight(pfrom->GetId(), pindex->GetBlockHash(), 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 (nodestate->fSupportsDesiredCmpctVersion && 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); - } - connman.PushMessage(pfrom, msgMaker.Make(NetMsgType::GETDATA, vGetData)); - } - } - } - } + // Headers received via a HEADERS message should be valid, and reflect + // the chain the peer is on. If we receive a known-invalid header, + // disconnect the peer if it is using one of our outbound connection + // slots. + bool should_punish = !pfrom->fInbound && !pfrom->m_manual_connection; + return ProcessHeadersMessage(pfrom, connman, headers, chainparams, should_punish); } else if (strCommand == NetMsgType::BLOCK && !fImporting && !fReindex) // Ignore blocks received while importing @@ -2391,11 +2569,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr LogPrint(BCLog::NET, "received block %s peer=%d\n", pblock->GetHash().ToString(), pfrom->GetId()); - // Process all blocks from whitelisted peers, even if not requested, - // unless we're still syncing with the network. - // Such an unrequested block may still be processed, subject to the - // conditions in AcceptBlock(). - bool forceProcessing = pfrom->fWhitelisted && !IsInitialBlockDownload(); + bool forceProcessing = false; const uint256 hash(pblock->GetHash()); { LOCK(cs_main); @@ -2438,7 +2612,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr pfrom->fSentAddr = true; pfrom->vAddrToSend.clear(); - std::vector<CAddress> vAddr = connman.GetAddresses(); + std::vector<CAddress> vAddr = connman->GetAddresses(); FastRandomContext insecure_rand; for (const CAddress &addr : vAddr) pfrom->PushAddress(addr, insecure_rand); @@ -2454,7 +2628,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr return true; } - if (connman.OutboundTargetReached(false) && !pfrom->fWhitelisted) + if (connman->OutboundTargetReached(false) && !pfrom->fWhitelisted) { LogPrint(BCLog::NET, "mempool request with bandwidth limit reached, disconnect peer=%d\n", pfrom->GetId()); pfrom->fDisconnect = true; @@ -2483,7 +2657,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr // it, if the remote node sends a ping once per second and this node takes 5 // seconds to respond to each, the 5th ping the remote sends would appear to // return very quickly. - connman.PushMessage(pfrom, msgMaker.Make(NetMsgType::PONG, nonce)); + connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::PONG, nonce)); } } @@ -2629,13 +2803,13 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr return true; } -static bool SendRejectsAndCheckIfBanned(CNode* pnode, CConnman& connman) +static bool SendRejectsAndCheckIfBanned(CNode* pnode, CConnman* connman) { AssertLockHeld(cs_main); CNodeState &state = *State(pnode->GetId()); for (const CBlockReject& reject : state.rejects) { - connman.PushMessage(pnode, CNetMsgMaker(INIT_PROTO_VERSION).Make(NetMsgType::REJECT, (std::string)NetMsgType::BLOCK, reject.chRejectCode, reject.strRejectReason, reject.hashBlock)); + connman->PushMessage(pnode, CNetMsgMaker(INIT_PROTO_VERSION).Make(NetMsgType::REJECT, (std::string)NetMsgType::BLOCK, reject.chRejectCode, reject.strRejectReason, reject.hashBlock)); } state.rejects.clear(); @@ -2643,7 +2817,7 @@ static bool SendRejectsAndCheckIfBanned(CNode* pnode, CConnman& connman) state.fShouldBan = false; if (pnode->fWhitelisted) LogPrintf("Warning: not punishing whitelisted peer %s!\n", pnode->addr.ToString()); - else if (pnode->fAddnode) + else if (pnode->m_manual_connection) LogPrintf("Warning: not punishing addnoded peer %s!\n", pnode->addr.ToString()); else { pnode->fDisconnect = true; @@ -2651,7 +2825,7 @@ static bool SendRejectsAndCheckIfBanned(CNode* pnode, CConnman& connman) LogPrintf("Warning: not banning local peer %s!\n", pnode->addr.ToString()); else { - connman.Ban(pnode->addr, BanReasonNodeMisbehaving); + connman->Ban(pnode->addr, BanReasonNodeMisbehaving); } } return true; @@ -2659,7 +2833,7 @@ static bool SendRejectsAndCheckIfBanned(CNode* pnode, CConnman& connman) return false; } -bool ProcessMessages(CNode* pfrom, CConnman& connman, const std::atomic<bool>& interruptMsgProc) +bool PeerLogicValidation::ProcessMessages(CNode* pfrom, std::atomic<bool>& interruptMsgProc) { const CChainParams& chainparams = Params(); // @@ -2693,7 +2867,7 @@ bool ProcessMessages(CNode* pfrom, CConnman& connman, const std::atomic<bool>& i // Just take one message msgs.splice(msgs.begin(), pfrom->vProcessMsg, pfrom->vProcessMsg.begin()); pfrom->nProcessQueueSize -= msgs.front().vRecv.size() + CMessageHeader::HEADER_SIZE; - pfrom->fPauseRecv = pfrom->nProcessQueueSize > connman.GetReceiveFloodSize(); + pfrom->fPauseRecv = pfrom->nProcessQueueSize > connman->GetReceiveFloodSize(); fMoreWork = !pfrom->vProcessMsg.empty(); } CNetMessage& msg(msgs.front()); @@ -2742,7 +2916,7 @@ bool ProcessMessages(CNode* pfrom, CConnman& connman, const std::atomic<bool>& i } catch (const std::ios_base::failure& e) { - connman.PushMessage(pfrom, CNetMsgMaker(INIT_PROTO_VERSION).Make(NetMsgType::REJECT, strCommand, REJECT_MALFORMED, std::string("error parsing message"))); + connman->PushMessage(pfrom, CNetMsgMaker(INIT_PROTO_VERSION).Make(NetMsgType::REJECT, strCommand, REJECT_MALFORMED, std::string("error parsing message"))); if (strstr(e.what(), "end of data")) { // Allow exceptions from under-length message on vRecv @@ -2779,6 +2953,135 @@ bool ProcessMessages(CNode* pfrom, CConnman& connman, const std::atomic<bool>& i return fMoreWork; } +void PeerLogicValidation::ConsiderEviction(CNode *pto, int64_t time_in_seconds) +{ + AssertLockHeld(cs_main); + + CNodeState &state = *State(pto->GetId()); + const CNetMsgMaker msgMaker(pto->GetSendVersion()); + + if (!state.m_chain_sync.m_protect && IsOutboundDisconnectionCandidate(pto) && state.fSyncStarted) { + // This is an outbound peer subject to disconnection if they don't + // announce a block with as much work as the current tip within + // CHAIN_SYNC_TIMEOUT + HEADERS_RESPONSE_TIME seconds (note: if + // their chain has more work than ours, we should sync to it, + // unless it's invalid, in which case we should find that out and + // disconnect from them elsewhere). + if (state.pindexBestKnownBlock != nullptr && state.pindexBestKnownBlock->nChainWork >= chainActive.Tip()->nChainWork) { + if (state.m_chain_sync.m_timeout != 0) { + state.m_chain_sync.m_timeout = 0; + state.m_chain_sync.m_work_header = nullptr; + state.m_chain_sync.m_sent_getheaders = false; + } + } else if (state.m_chain_sync.m_timeout == 0 || (state.m_chain_sync.m_work_header != nullptr && state.pindexBestKnownBlock != nullptr && state.pindexBestKnownBlock->nChainWork >= state.m_chain_sync.m_work_header->nChainWork)) { + // Our best block known by this peer is behind our tip, and we're either noticing + // that for the first time, OR this peer was able to catch up to some earlier point + // where we checked against our tip. + // Either way, set a new timeout based on current tip. + state.m_chain_sync.m_timeout = time_in_seconds + CHAIN_SYNC_TIMEOUT; + state.m_chain_sync.m_work_header = chainActive.Tip(); + state.m_chain_sync.m_sent_getheaders = false; + } else if (state.m_chain_sync.m_timeout > 0 && time_in_seconds > state.m_chain_sync.m_timeout) { + // No evidence yet that our peer has synced to a chain with work equal to that + // of our tip, when we first detected it was behind. Send a single getheaders + // message to give the peer a chance to update us. + if (state.m_chain_sync.m_sent_getheaders) { + // They've run out of time to catch up! + LogPrintf("Disconnecting outbound peer %d for old chain, best known block = %s\n", pto->GetId(), state.pindexBestKnownBlock != nullptr ? state.pindexBestKnownBlock->GetBlockHash().ToString() : "<none>"); + pto->fDisconnect = true; + } else { + LogPrint(BCLog::NET, "sending getheaders to outbound peer=%d to verify chain work (current best known block:%s, benchmark blockhash: %s)\n", pto->GetId(), state.pindexBestKnownBlock != nullptr ? state.pindexBestKnownBlock->GetBlockHash().ToString() : "<none>", state.m_chain_sync.m_work_header->GetBlockHash().ToString()); + connman->PushMessage(pto, msgMaker.Make(NetMsgType::GETHEADERS, chainActive.GetLocator(state.m_chain_sync.m_work_header->pprev), uint256())); + state.m_chain_sync.m_sent_getheaders = true; + constexpr int64_t HEADERS_RESPONSE_TIME = 120; // 2 minutes + // Bump the timeout to allow a response, which could clear the timeout + // (if the response shows the peer has synced), reset the timeout (if + // the peer syncs to the required work but not to our tip), or result + // in disconnect (if we advance to the timeout and pindexBestKnownBlock + // has not sufficiently progressed) + state.m_chain_sync.m_timeout = time_in_seconds + HEADERS_RESPONSE_TIME; + } + } + } +} + +void PeerLogicValidation::EvictExtraOutboundPeers(int64_t time_in_seconds) +{ + // Check whether we have too many outbound peers + int extra_peers = connman->GetExtraOutboundCount(); + if (extra_peers > 0) { + // If we have more outbound peers than we target, disconnect one. + // Pick the outbound peer that least recently announced + // us a new block, with ties broken by choosing the more recent + // connection (higher node id) + NodeId worst_peer = -1; + int64_t oldest_block_announcement = std::numeric_limits<int64_t>::max(); + + LOCK(cs_main); + + connman->ForEachNode([&](CNode* pnode) { + // Ignore non-outbound peers, or nodes marked for disconnect already + if (!IsOutboundDisconnectionCandidate(pnode) || pnode->fDisconnect) return; + CNodeState *state = State(pnode->GetId()); + if (state == nullptr) return; // shouldn't be possible, but just in case + // Don't evict our protected peers + if (state->m_chain_sync.m_protect) return; + if (state->m_last_block_announcement < oldest_block_announcement || (state->m_last_block_announcement == oldest_block_announcement && pnode->GetId() > worst_peer)) { + worst_peer = pnode->GetId(); + oldest_block_announcement = state->m_last_block_announcement; + } + }); + if (worst_peer != -1) { + bool disconnected = connman->ForNode(worst_peer, [&](CNode *pnode) { + // Only disconnect a peer that has been connected to us for + // some reasonable fraction of our check-frequency, to give + // it time for new information to have arrived. + // Also don't disconnect any peer we're trying to download a + // block from. + CNodeState &state = *State(pnode->GetId()); + if (time_in_seconds - pnode->nTimeConnected > MINIMUM_CONNECT_TIME && state.nBlocksInFlight == 0) { + LogPrint(BCLog::NET, "disconnecting extra outbound peer=%d (last block announcement received at time %d)\n", pnode->GetId(), oldest_block_announcement); + pnode->fDisconnect = true; + return true; + } else { + LogPrint(BCLog::NET, "keeping outbound peer=%d chosen for eviction (connect time: %d, blocks_in_flight: %d)\n", pnode->GetId(), pnode->nTimeConnected, state.nBlocksInFlight); + return false; + } + }); + if (disconnected) { + // If we disconnected an extra peer, that means we successfully + // connected to at least one peer after the last time we + // detected a stale tip. Don't try any more extra peers until + // we next detect a stale tip, to limit the load we put on the + // network from these extra connections. + connman->SetTryNewOutboundPeer(false); + } + } + } +} + +void PeerLogicValidation::CheckForStaleTipAndEvictPeers(const Consensus::Params &consensusParams) +{ + if (connman == nullptr) return; + + int64_t time_in_seconds = GetTime(); + + EvictExtraOutboundPeers(time_in_seconds); + + if (time_in_seconds > m_stale_tip_check_time) { + LOCK(cs_main); + // Check whether our tip is stale, and if so, allow using an extra + // outbound peer + if (TipMayBeStale(consensusParams)) { + LogPrintf("Potential stale tip detected, will try using extra outbound peer (last tip update: %d seconds ago)\n", time_in_seconds - g_last_tip_update); + connman->SetTryNewOutboundPeer(true); + } else if (connman->GetTryNewOutboundPeer()) { + connman->SetTryNewOutboundPeer(false); + } + m_stale_tip_check_time = time_in_seconds + STALE_CHECK_INTERVAL; + } +} + class CompareInvMempoolOrder { CTxMemPool *mp; @@ -2796,7 +3099,7 @@ public: } }; -bool SendMessages(CNode* pto, CConnman& connman, const std::atomic<bool>& interruptMsgProc) +bool PeerLogicValidation::SendMessages(CNode* pto, std::atomic<bool>& interruptMsgProc) { const Consensus::Params& consensusParams = Params().GetConsensus(); { @@ -2828,11 +3131,11 @@ bool SendMessages(CNode* pto, CConnman& connman, const std::atomic<bool>& interr pto->nPingUsecStart = GetTimeMicros(); if (pto->nVersion > BIP0031_VERSION) { pto->nPingNonceSent = nonce; - connman.PushMessage(pto, msgMaker.Make(NetMsgType::PING, nonce)); + connman->PushMessage(pto, msgMaker.Make(NetMsgType::PING, nonce)); } else { // Peer is too old to support ping command with nonce, pong will never arrive. pto->nPingNonceSent = 0; - connman.PushMessage(pto, msgMaker.Make(NetMsgType::PING)); + connman->PushMessage(pto, msgMaker.Make(NetMsgType::PING)); } } @@ -2867,14 +3170,14 @@ bool SendMessages(CNode* pto, CConnman& connman, const std::atomic<bool>& interr // receiver rejects addr messages larger than 1000 if (vAddr.size() >= 1000) { - connman.PushMessage(pto, msgMaker.Make(NetMsgType::ADDR, vAddr)); + connman->PushMessage(pto, msgMaker.Make(NetMsgType::ADDR, vAddr)); vAddr.clear(); } } } pto->vAddrToSend.clear(); if (!vAddr.empty()) - connman.PushMessage(pto, msgMaker.Make(NetMsgType::ADDR, vAddr)); + connman->PushMessage(pto, msgMaker.Make(NetMsgType::ADDR, vAddr)); // we only send the big addr message once if (pto->vAddrToSend.capacity() > 40) pto->vAddrToSend.shrink_to_fit(); @@ -2901,7 +3204,7 @@ bool SendMessages(CNode* pto, CConnman& connman, const std::atomic<bool>& interr if (pindexStart->pprev) pindexStart = pindexStart->pprev; LogPrint(BCLog::NET, "initial getheaders (%d) to peer=%d (startheight:%d)\n", pindexStart->nHeight, pto->GetId(), pto->nStartingHeight); - connman.PushMessage(pto, msgMaker.Make(NetMsgType::GETHEADERS, chainActive.GetLocator(pindexStart), uint256())); + connman->PushMessage(pto, msgMaker.Make(NetMsgType::GETHEADERS, chainActive.GetLocator(pindexStart), uint256())); } } @@ -2910,7 +3213,7 @@ bool SendMessages(CNode* pto, CConnman& connman, const std::atomic<bool>& interr // transactions become unconfirmed and spams other nodes. if (!fReindex && !fImporting && !IsInitialBlockDownload()) { - GetMainSignals().Broadcast(nTimeBestReceived, &connman); + GetMainSignals().Broadcast(nTimeBestReceived, connman); } // @@ -2994,10 +3297,10 @@ bool SendMessages(CNode* pto, CConnman& connman, const std::atomic<bool>& interr LOCK(cs_most_recent_block); if (most_recent_block_hash == pBestIndex->GetBlockHash()) { if (state.fWantsCmpctWitness || !fWitnessesPresentInMostRecentCompactBlock) - connman.PushMessage(pto, msgMaker.Make(nSendFlags, NetMsgType::CMPCTBLOCK, *most_recent_compact_block)); + connman->PushMessage(pto, msgMaker.Make(nSendFlags, NetMsgType::CMPCTBLOCK, *most_recent_compact_block)); else { CBlockHeaderAndShortTxIDs cmpctblock(*most_recent_block, state.fWantsCmpctWitness); - connman.PushMessage(pto, msgMaker.Make(nSendFlags, NetMsgType::CMPCTBLOCK, cmpctblock)); + connman->PushMessage(pto, msgMaker.Make(nSendFlags, NetMsgType::CMPCTBLOCK, cmpctblock)); } fGotBlockFromCache = true; } @@ -3007,7 +3310,7 @@ bool SendMessages(CNode* pto, CConnman& connman, const std::atomic<bool>& interr bool ret = ReadBlockFromDisk(block, pBestIndex, consensusParams); assert(ret); CBlockHeaderAndShortTxIDs cmpctblock(block, state.fWantsCmpctWitness); - connman.PushMessage(pto, msgMaker.Make(nSendFlags, NetMsgType::CMPCTBLOCK, cmpctblock)); + connman->PushMessage(pto, msgMaker.Make(nSendFlags, NetMsgType::CMPCTBLOCK, cmpctblock)); } state.pindexBestHeaderSent = pBestIndex; } else if (state.fPreferHeaders) { @@ -3020,7 +3323,7 @@ bool SendMessages(CNode* pto, CConnman& connman, const std::atomic<bool>& interr LogPrint(BCLog::NET, "%s: sending header %s to peer=%d\n", __func__, vHeaders.front().GetHash().ToString(), pto->GetId()); } - connman.PushMessage(pto, msgMaker.Make(NetMsgType::HEADERS, vHeaders)); + connman->PushMessage(pto, msgMaker.Make(NetMsgType::HEADERS, vHeaders)); state.pindexBestHeaderSent = pBestIndex; } else fRevertToInv = true; @@ -3066,7 +3369,7 @@ bool SendMessages(CNode* pto, CConnman& connman, const std::atomic<bool>& interr for (const uint256& hash : pto->vInventoryBlockToSend) { vInv.push_back(CInv(MSG_BLOCK, hash)); if (vInv.size() == MAX_INV_SZ) { - connman.PushMessage(pto, msgMaker.Make(NetMsgType::INV, vInv)); + connman->PushMessage(pto, msgMaker.Make(NetMsgType::INV, vInv)); vInv.clear(); } } @@ -3112,7 +3415,7 @@ bool SendMessages(CNode* pto, CConnman& connman, const std::atomic<bool>& interr pto->filterInventoryKnown.insert(hash); vInv.push_back(inv); if (vInv.size() == MAX_INV_SZ) { - connman.PushMessage(pto, msgMaker.Make(NetMsgType::INV, vInv)); + connman->PushMessage(pto, msgMaker.Make(NetMsgType::INV, vInv)); vInv.clear(); } } @@ -3178,7 +3481,7 @@ bool SendMessages(CNode* pto, CConnman& connman, const std::atomic<bool>& interr } } if (vInv.size() == MAX_INV_SZ) { - connman.PushMessage(pto, msgMaker.Make(NetMsgType::INV, vInv)); + connman->PushMessage(pto, msgMaker.Make(NetMsgType::INV, vInv)); vInv.clear(); } pto->filterInventoryKnown.insert(hash); @@ -3186,7 +3489,7 @@ bool SendMessages(CNode* pto, CConnman& connman, const std::atomic<bool>& interr } } if (!vInv.empty()) - connman.PushMessage(pto, msgMaker.Make(NetMsgType::INV, vInv)); + connman->PushMessage(pto, msgMaker.Make(NetMsgType::INV, vInv)); // Detect whether we're stalling nNow = GetTimeMicros(); @@ -3245,6 +3548,9 @@ bool SendMessages(CNode* pto, CConnman& connman, const std::atomic<bool>& interr } } + // Check that outbound peers have reasonable chains + // GetTime() is used by this anti-DoS logic so we can test this using mocktime + ConsiderEviction(pto, GetTime()); // // Message: getdata (blocks) @@ -3281,7 +3587,7 @@ bool SendMessages(CNode* pto, CConnman& connman, const std::atomic<bool>& interr vGetData.push_back(inv); if (vGetData.size() >= 1000) { - connman.PushMessage(pto, msgMaker.Make(NetMsgType::GETDATA, vGetData)); + connman->PushMessage(pto, msgMaker.Make(NetMsgType::GETDATA, vGetData)); vGetData.clear(); } } else { @@ -3291,7 +3597,7 @@ bool SendMessages(CNode* pto, CConnman& connman, const std::atomic<bool>& interr pto->mapAskFor.erase(pto->mapAskFor.begin()); } if (!vGetData.empty()) - connman.PushMessage(pto, msgMaker.Make(NetMsgType::GETDATA, vGetData)); + connman->PushMessage(pto, msgMaker.Make(NetMsgType::GETDATA, vGetData)); // // Message: feefilter @@ -3308,7 +3614,7 @@ bool SendMessages(CNode* pto, CConnman& connman, const std::atomic<bool>& interr // We always have a fee filter of at least minRelayTxFee filterToSend = std::max(filterToSend, ::minRelayTxFee.GetFeePerK()); if (filterToSend != pto->lastSentFeeFilter) { - connman.PushMessage(pto, msgMaker.Make(NetMsgType::FEEFILTER, filterToSend)); + connman->PushMessage(pto, msgMaker.Make(NetMsgType::FEEFILTER, filterToSend)); pto->lastSentFeeFilter = filterToSend; } pto->nextSendTimeFeeFilter = PoissonNextSend(timeNow, AVG_FEEFILTER_BROADCAST_INTERVAL); |