diff options
Diffstat (limited to 'src/net_processing.cpp')
| -rw-r--r-- | src/net_processing.cpp | 1163 |
1 files changed, 762 insertions, 401 deletions
diff --git a/src/net_processing.cpp b/src/net_processing.cpp index 4d832f3711..99b96a988a 100644 --- a/src/net_processing.cpp +++ b/src/net_processing.cpp @@ -3,32 +3,34 @@ // Distributed under the MIT software license, see the accompanying // file COPYING or http://www.opensource.org/licenses/mit-license.php. -#include "net_processing.h" - -#include "addrman.h" -#include "arith_uint256.h" -#include "blockencodings.h" -#include "chainparams.h" -#include "consensus/validation.h" -#include "hash.h" -#include "init.h" -#include "validation.h" -#include "merkleblock.h" -#include "net.h" -#include "netmessagemaker.h" -#include "netbase.h" -#include "policy/fees.h" -#include "policy/policy.h" -#include "primitives/block.h" -#include "primitives/transaction.h" -#include "random.h" -#include "tinyformat.h" -#include "txmempool.h" -#include "ui_interface.h" -#include "util.h" -#include "utilmoneystr.h" -#include "utilstrencodings.h" -#include "validationinterface.h" +#include <net_processing.h> + +#include <addrman.h> +#include <arith_uint256.h> +#include <blockencodings.h> +#include <chainparams.h> +#include <consensus/validation.h> +#include <hash.h> +#include <init.h> +#include <validation.h> +#include <merkleblock.h> +#include <net.h> +#include <netmessagemaker.h> +#include <netbase.h> +#include <policy/fees.h> +#include <policy/policy.h> +#include <primitives/block.h> +#include <primitives/transaction.h> +#include <random.h> +#include <reverse_iterator.h> +#include <scheduler.h> +#include <tinyformat.h> +#include <txmempool.h> +#include <ui_interface.h> +#include <util.h> +#include <utilmoneystr.h> +#include <utilstrencodings.h> +#include <validationinterface.h> #if defined(NDEBUG) # error "Bitcoin cannot be compiled without assertions." @@ -60,6 +62,14 @@ static std::vector<std::pair<uint256, CTransactionRef>> vExtraTxnForCompact GUAR static const uint64_t RANDOMIZER_ID_ADDRESS_RELAY = 0x3cac0035b5866b90ULL; // SHA256("main address relay")[0:8] +/// Age after which a stale block will no longer be served if requested as +/// protection against fingerprinting. Set to one month, denominated in seconds. +static const int STALE_RELAY_AGE_LIMIT = 30 * 24 * 60 * 60; + +/// Age after which a block is considered historical for purposes of rate +/// limiting block relay. Set to one week, denominated in seconds. +static const int HISTORICAL_BLOCK_AGE = 7 * 24 * 60 * 60; + // Internal stuff namespace { /** Number of nodes with fSyncStarted. */ @@ -115,6 +125,12 @@ 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; @@ -122,11 +138,6 @@ namespace { std::deque<std::pair<int64_t, MapRelay::iterator>> vRelayExpiration; } // namespace -////////////////////////////////////////////////////////////////////////////// -// -// Registration of network node signals. -// - namespace { struct CBlockReject { @@ -197,14 +208,44 @@ 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; fShouldBan = false; - pindexBestKnownBlock = NULL; + pindexBestKnownBlock = nullptr; hashLastUnknownBlock.SetNull(); - pindexLastCommonBlock = NULL; - pindexBestHeaderSent = NULL; + pindexLastCommonBlock = nullptr; + pindexBestHeaderSent = nullptr; nUnconnectingHeaders = 0; fSyncStarted = false; nHeadersSyncTimeout = 0; @@ -219,6 +260,8 @@ struct CNodeState { fHaveWitness = false; fWantsCmpctWitness = false; fSupportsDesiredCmpctVersion = false; + m_chain_sync = { 0, nullptr, false, false }; + m_last_block_announcement = 0; } }; @@ -229,7 +272,7 @@ std::map<NodeId, CNodeState> mapNodeState; CNodeState *State(NodeId pnode) { std::map<NodeId, CNodeState>::iterator it = mapNodeState.find(pnode); if (it == mapNodeState.end()) - return NULL; + return nullptr; return &it->second; } @@ -243,7 +286,7 @@ 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(); @@ -254,7 +297,7 @@ 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) { @@ -264,49 +307,6 @@ 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 @@ -314,6 +314,7 @@ bool MarkBlockAsReceived(const uint256& hash) { std::map<uint256, std::pair<NodeId, std::list<QueuedBlock>::iterator> >::iterator itInFlight = mapBlocksInFlight.find(hash); if (itInFlight != mapBlocksInFlight.end()) { CNodeState *state = State(itInFlight->second.first); + assert(state != nullptr); state->nBlocksInFlightValidHeaders -= itInFlight->second.second->fValidatedHeaders; if (state->nBlocksInFlightValidHeaders == 0 && itInFlight->second.second->fValidatedHeaders) { // Last validated block on the queue was received. @@ -335,9 +336,9 @@ bool MarkBlockAsReceived(const uint256& hash) { // Requires cs_main. // returns false, still setting pit, if the block was already in flight from the same peer // pit will only be valid as long as the same cs_main lock is being held -bool MarkBlockAsInFlight(NodeId nodeid, const uint256& hash, const CBlockIndex* pindex = NULL, std::list<QueuedBlock>::iterator** pit = NULL) { +bool MarkBlockAsInFlight(NodeId nodeid, const uint256& hash, const CBlockIndex* pindex = nullptr, std::list<QueuedBlock>::iterator** pit = nullptr) { CNodeState *state = State(nodeid); - assert(state != NULL); + assert(state != nullptr); // Short-circuit most stuff in case its from the same node std::map<uint256, std::pair<NodeId, std::list<QueuedBlock>::iterator> >::iterator itInFlight = mapBlocksInFlight.find(hash); @@ -352,14 +353,14 @@ bool MarkBlockAsInFlight(NodeId nodeid, const uint256& hash, const CBlockIndex* MarkBlockAsReceived(hash); std::list<QueuedBlock>::iterator it = state->vBlocksInFlight.insert(state->vBlocksInFlight.end(), - {hash, pindex, pindex != NULL, std::unique_ptr<PartiallyDownloadedBlock>(pit ? new PartiallyDownloadedBlock(&mempool) : NULL)}); + {hash, pindex, pindex != nullptr, std::unique_ptr<PartiallyDownloadedBlock>(pit ? new PartiallyDownloadedBlock(&mempool) : nullptr)}); state->nBlocksInFlight++; state->nBlocksInFlightValidHeaders += it->fValidatedHeaders; if (state->nBlocksInFlight == 1) { // We're starting a block download (batch) from this peer. state->nDownloadingSince = GetTimeMicros(); } - if (state->nBlocksInFlightValidHeaders == 1 && pindex != NULL) { + if (state->nBlocksInFlightValidHeaders == 1 && pindex != nullptr) { nPeersWithValidatedDownloads++; } itInFlight = mapBlocksInFlight.insert(std::make_pair(hash, std::make_pair(nodeid, it))).first; @@ -371,12 +372,12 @@ bool MarkBlockAsInFlight(NodeId nodeid, const uint256& hash, const CBlockIndex* /** Check whether the last unknown block a peer advertised is not yet known. */ void ProcessBlockAvailability(NodeId nodeid) { CNodeState *state = State(nodeid); - assert(state != NULL); + assert(state != nullptr); if (!state->hashLastUnknownBlock.IsNull()) { BlockMap::iterator itOld = mapBlockIndex.find(state->hashLastUnknownBlock); if (itOld != mapBlockIndex.end() && itOld->second->nChainWork > 0) { - if (state->pindexBestKnownBlock == NULL || itOld->second->nChainWork >= state->pindexBestKnownBlock->nChainWork) + if (state->pindexBestKnownBlock == nullptr || itOld->second->nChainWork >= state->pindexBestKnownBlock->nChainWork) state->pindexBestKnownBlock = itOld->second; state->hashLastUnknownBlock.SetNull(); } @@ -386,14 +387,14 @@ void ProcessBlockAvailability(NodeId nodeid) { /** Update tracking information about which blocks a peer is assumed to have. */ void UpdateBlockAvailability(NodeId nodeid, const uint256 &hash) { CNodeState *state = State(nodeid); - assert(state != NULL); + assert(state != nullptr); ProcessBlockAvailability(nodeid); BlockMap::iterator it = mapBlockIndex.find(hash); if (it != mapBlockIndex.end() && it->second->nChainWork > 0) { // An actually better block was announced. - if (state->pindexBestKnownBlock == NULL || it->second->nChainWork >= state->pindexBestKnownBlock->nChainWork) + if (state->pindexBestKnownBlock == nullptr || it->second->nChainWork >= state->pindexBestKnownBlock->nChainWork) state->pindexBestKnownBlock = it->second; } else { // An unknown block was announced; just assume that the latest one is the best one. @@ -401,7 +402,7 @@ 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) { @@ -416,26 +417,33 @@ void MaybeSetPeerAsAnnouncingHeaderAndIDs(NodeId nodeid, CConnman& connman) { return; } } - connman.ForNode(nodeid, [&connman](CNode* pfrom){ - bool fAnnounceUsingCMPCTBLOCK = false; + connman->ForNode(nodeid, [connman](CNode* pfrom){ 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, nCMPCTBLOCKVersion](CNode* pnodeStop){ + connman->PushMessage(pnodeStop, CNetMsgMaker(pnodeStop->GetSendVersion()).Make(NetMsgType::SENDCMPCT, /*fAnnounceUsingCMPCTBLOCK=*/false, 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=*/true, 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) { @@ -460,17 +468,17 @@ void FindNextBlocksToDownload(NodeId nodeid, unsigned int count, std::vector<con vBlocks.reserve(vBlocks.size() + count); CNodeState *state = State(nodeid); - assert(state != NULL); + assert(state != nullptr); // Make sure pindexBestKnownBlock is up to date, we'll need it. ProcessBlockAvailability(nodeid); - if (state->pindexBestKnownBlock == NULL || 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; } - if (state->pindexLastCommonBlock == NULL) { + if (state->pindexLastCommonBlock == nullptr) { // Bootstrap quickly by guessing a parent of our best tip is the forking point. // Guessing wrong in either direction is not a problem. state->pindexLastCommonBlock = chainActive[std::min(state->pindexBestKnownBlock->nHeight, chainActive.Height())]; @@ -542,10 +550,73 @@ 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); - if (state == NULL) + if (state == nullptr) return false; stats.nMisbehavior = state->nMisbehavior; stats.nSyncHeight = state->pindexBestKnownBlock ? state->pindexBestKnownBlock->nHeight : -1; @@ -557,30 +628,14 @@ 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 // -void AddToCompactExtraTransactions(const CTransactionRef& tx) +void AddToCompactExtraTransactions(const CTransactionRef& tx) EXCLUSIVE_LOCKS_REQUIRED(cs_main) { - size_t max_extra_txn = GetArg("-blockreconstructionextratxn", DEFAULT_BLOCK_RECONSTRUCTION_EXTRA_TXN); + size_t max_extra_txn = gArgs.GetArg("-blockreconstructionextratxn", DEFAULT_BLOCK_RECONSTRUCTION_EXTRA_TXN); if (max_extra_txn <= 0) return; if (!vExtraTxnForCompact.size()) @@ -699,11 +754,11 @@ void Misbehaving(NodeId pnode, int howmuch) return; CNodeState *state = State(pnode); - if (state == NULL) + if (state == nullptr) return; state->nMisbehavior += howmuch; - int banscore = GetArg("-banscore", DEFAULT_BANSCORE_THRESHOLD); + int banscore = gArgs.GetArg("-banscore", DEFAULT_BANSCORE_THRESHOLD); if (state->nMisbehavior >= banscore && state->nMisbehavior - howmuch < banscore) { LogPrintf("%s: %s peer=%d (%d -> %d) BAN THRESHOLD EXCEEDED\n", __func__, state->name, pnode, state->nMisbehavior-howmuch, state->nMisbehavior); @@ -724,9 +779,30 @@ void Misbehaving(NodeId pnode, int howmuch) // blockchain -> download logic notification // -PeerLogicValidation::PeerLogicValidation(CConnman* connmanIn) : connman(connmanIn) { +// To prevent fingerprinting attacks, only send blocks/headers outside of the +// active chain if they are no more than a month older (both in time, and in +// best equivalent proof of work) than the best header chain we know about and +// we fully-validated them at some point. +static bool BlockRequestAllowed(const CBlockIndex* pindex, const Consensus::Params& consensusParams) +{ + AssertLockHeld(cs_main); + if (chainActive.Contains(pindex)) return true; + return pindex->IsValid(BLOCK_VALID_SCRIPTS) && (pindexBestHeader != nullptr) && + (pindexBestHeader->GetBlockTime() - pindex->GetBlockTime() < STALE_RELAY_AGE_LIMIT) && + (GetBlockProofEquivalentTime(*pindexBestHeader, *pindex, *pindexBestHeader, consensusParams) < STALE_RELAY_AGE_LIMIT); +} + +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) { @@ -757,6 +833,8 @@ 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 @@ -827,7 +905,7 @@ void PeerLogicValidation::UpdatedBlockTip(const CBlockIndex *pindexNew, const CB // Relay inventory, but don't relay old inventory during initial block download. connman->ForEachNode([nNewHeight, &vHashes](CNode* pnode) { if (nNewHeight > (pnode->nStartingHeight != -1 ? pnode->nStartingHeight - 2000 : 0)) { - BOOST_REVERSE_FOREACH(const uint256& hash, vHashes) { + for (const uint256& hash : reverse_iterate(vHashes)) { pnode->PushBlockHash(hash); } } @@ -864,7 +942,7 @@ 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()) @@ -909,16 +987,16 @@ 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) @@ -926,7 +1004,7 @@ 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}}}; @@ -951,10 +1029,10 @@ 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; @@ -998,25 +1076,14 @@ void static ProcessGetData(CNode* pfrom, const Consensus::Params& consensusParam CValidationState dummy; ActivateBestChain(dummy, Params(), a_recent_block); } - if (chainActive.Contains(mi->second)) { - send = true; - } else { - static const int nOneMonth = 30 * 24 * 60 * 60; - // To prevent fingerprinting attacks, only send blocks outside of the active - // chain if they are valid, and no more than a month older (both in time, and in - // best equivalent proof of work) than the best header chain we know about. - send = mi->second->IsValid(BLOCK_VALID_SCRIPTS) && (pindexBestHeader != NULL) && - (pindexBestHeader->GetBlockTime() - mi->second->GetBlockTime() < nOneMonth) && - (GetBlockProofEquivalentTime(*pindexBestHeader, *mi->second, *pindexBestHeader, consensusParams) < nOneMonth); - if (!send) { - LogPrintf("%s: ignoring request from peer=%i for old block that isn't in the main chain\n", __func__, pfrom->GetId()); - } + send = BlockRequestAllowed(mi->second, consensusParams); + if (!send) { + LogPrint(BCLog::NET, "%s: ignoring request from peer=%i for old block that isn't in the main chain\n", __func__, pfrom->GetId()); } } // 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 != NULL) && (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() > HISTORICAL_BLOCK_AGE)) || inv.type == MSG_FILTERED_BLOCK) && !pfrom->fWhitelisted) { LogPrint(BCLog::NET, "historical block serving limit reached, disconnect peer=%d\n", pfrom->GetId()); @@ -1024,6 +1091,16 @@ void static ProcessGetData(CNode* pfrom, const Consensus::Params& consensusParam pfrom->fDisconnect = true; send = false; } + // Avoid leaking prune-height by never sending blocks below the NODE_NETWORK_LIMITED threshold + if (send && !pfrom->fWhitelisted && ( + (((pfrom->GetLocalServices() & NODE_NETWORK_LIMITED) == NODE_NETWORK_LIMITED) && ((pfrom->GetLocalServices() & NODE_NETWORK) != NODE_NETWORK) && (chainActive.Tip()->nHeight - mi->second->nHeight > (int)NODE_NETWORK_LIMITED_MIN_BLOCKS + 2 /* add two blocks buffer extension for possible races */) ) + )) { + LogPrint(BCLog::NET, "Ignore block request below NODE_NETWORK_LIMITED threshold from peer=%d\n", pfrom->GetId()); + + //disconnect node and prevent it from stalling (would otherwise wait for the missing block) + pfrom->fDisconnect = true; + send = false; + } // Pruned nodes may have deleted the block, so check whether // it's available before trying to send. if (send && (mi->second->nStatus & BLOCK_HAVE_DATA)) @@ -1039,9 +1116,9 @@ 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; @@ -1054,7 +1131,7 @@ 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 - @@ -1063,7 +1140,7 @@ 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 @@ -1078,13 +1155,13 @@ 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)); } } @@ -1096,7 +1173,7 @@ 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(); } } @@ -1108,14 +1185,14 @@ 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; } } @@ -1142,7 +1219,7 @@ 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)); } } @@ -1154,7 +1231,7 @@ 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()) { @@ -1168,13 +1245,232 @@ 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 (IsArgSet("-dropmessagestest") && GetRand(GetArg("-dropmessagestest", 0)) == 0) + if (gArgs.IsArgSet("-dropmessagestest") && GetRand(gArgs.GetArg("-dropmessagestest", 0)) == 0) { LogPrintf("dropmessagestest DROPPING RECV MESSAGE\n"); return true; @@ -1224,7 +1520,7 @@ 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; @@ -1248,22 +1544,33 @@ 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) + if (!pfrom->fInbound && !pfrom->fFeeler && !pfrom->m_manual_connection && !HasAllDesirableServiceFlags(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, - strprintf("Expected to offer services %08x", pfrom->nServicesExpected))); + LogPrint(BCLog::NET, "peer=%d does not offer the expected services (%08x offered, %08x expected); disconnecting\n", pfrom->GetId(), nServices, GetDesirableServiceFlags(nServices)); + connman->PushMessage(pfrom, CNetMsgMaker(INIT_PROTO_VERSION).Make(NetMsgType::REJECT, strCommand, REJECT_NONSTANDARD, + strprintf("Expected to offer services %08x", GetDesirableServiceFlags(nServices)))); pfrom->fDisconnect = true; return false; } + if (nServices & ((1 << 7) | (1 << 5))) { + if (GetTime() < 1533096000) { + // Immediately disconnect peers that use service bits 6 or 8 until August 1st, 2018 + // These bits have been used as a flag to indicate that a node is running incompatible + // consensus rules instead of changing the network magic, so we're stuck disconnecting + // based on these service bits, at least for a while. + pfrom->fDisconnect = true; + return false; + } + } + if (nVersion < MIN_PEER_PROTO_VERSION) { // 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, + LogPrint(BCLog::NET, "peer=%d using obsolete version %i; disconnecting\n", pfrom->GetId(), nVersion); + 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; @@ -1283,7 +1590,7 @@ 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; @@ -1299,7 +1606,7 @@ 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); @@ -1350,19 +1657,19 @@ 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; if (fLogIPs) remoteAddr = ", peeraddr=" + pfrom->addr.ToString(); - LogPrintf("receive version message: %s: version %d, blocks=%d, us=%s, peer=%d%s\n", + LogPrint(BCLog::NET, "receive version message: %s: version %d, blocks=%d, us=%s, peer=%d%s\n", cleanSubVer, pfrom->nVersion, pfrom->nStartingHeight, addrMe.ToString(), pfrom->GetId(), remoteAddr); @@ -1374,7 +1681,7 @@ 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. @@ -1405,6 +1712,9 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr // Mark this node as currently connected, so we update its timestamp later. LOCK(cs_main); State(pfrom->GetId())->fCurrentlyConnected = true; + LogPrintf("New outbound peer connected: version: %d, blocks=%d, peer=%d%s\n", + pfrom->nVersion.load(), pfrom->nStartingHeight, pfrom->GetId(), + (fLogIPs ? strprintf(", peeraddr=%s", pfrom->addr.ToString()) : "")); } if (pfrom->nVersion >= SENDHEADERS_VERSION) { @@ -1412,7 +1722,7 @@ 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 @@ -1423,9 +1733,9 @@ 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; } @@ -1444,7 +1754,7 @@ 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) { @@ -1462,7 +1772,10 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr if (interruptMsgProc) return true; - if ((addr.nServices & REQUIRED_SERVICES) != REQUIRED_SERVICES) + // We only bother storing full nodes, though this may include + // things which we would not make an outbound connection to, in + // part because we may make feeler connections to them. + if (!MayHaveUsefulAddressDB(addr.nServices)) continue; if (addr.nTime <= 100000000 || addr.nTime > nNow + 10 * 60) @@ -1478,7 +1791,7 @@ 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) @@ -1529,7 +1842,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr bool fBlocksOnly = !fRelayTxes; // Allow whitelisted peers to send data other than blocks in blocks only mode if whitelistrelay is true - if (pfrom->fWhitelisted && GetBoolArg("-whitelistrelay", DEFAULT_WHITELISTRELAY)) + if (pfrom->fWhitelisted && gArgs.GetBoolArg("-whitelistrelay", DEFAULT_WHITELISTRELAY)) fBlocksOnly = false; LOCK(cs_main); @@ -1556,7 +1869,7 @@ 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()); } } @@ -1680,7 +1993,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr BlockMap::iterator it = mapBlockIndex.find(req.blockhash); if (it == mapBlockIndex.end() || !(it->second->nStatus & BLOCK_HAVE_DATA)) { - LogPrintf("Peer %d sent us a getblocktxn for a block we don't have", pfrom->GetId()); + LogPrint(BCLog::NET, "Peer %d sent us a getblocktxn for a block we don't have", pfrom->GetId()); return true; } @@ -1722,7 +2035,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr } CNodeState *nodestate = State(pfrom->GetId()); - const CBlockIndex* pindex = NULL; + const CBlockIndex* pindex = nullptr; if (locator.IsNull()) { // If locator is null, return the hashStop block @@ -1730,6 +2043,11 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr if (mi == mapBlockIndex.end()) return true; pindex = (*mi).second; + + if (!BlockRequestAllowed(pindex, chainparams.GetConsensus())) { + LogPrint(BCLog::NET, "%s: ignoring request from peer=%i for old block header that isn't in the main chain\n", __func__, pfrom->GetId()); + return true; + } } else { @@ -1749,7 +2067,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr if (--nLimit <= 0 || pindex->GetBlockHash() == hashStop) break; } - // pindex can be NULL either if we sent chainActive.Tip() OR + // pindex can be nullptr either if we sent chainActive.Tip() OR // if our peer has chainActive.Tip() (and thus we are sending an empty // headers message). In both cases it's safe to update // pindexBestHeaderSent to be our tip. @@ -1762,7 +2080,7 @@ 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)); } @@ -1770,7 +2088,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr { // Stop processing the transaction early if // We are in blocks only mode and peer is either not whitelisted or whitelistrelay is off - if (!fRelayTxes && (!pfrom->fWhitelisted || !GetBoolArg("-whitelistrelay", DEFAULT_WHITELISTRELAY))) + if (!fRelayTxes && (!pfrom->fWhitelisted || !gArgs.GetBoolArg("-whitelistrelay", DEFAULT_WHITELISTRELAY))) { LogPrint(BCLog::NET, "transaction sent in violation of protocol peer=%d\n", pfrom->GetId()); return true; @@ -1795,8 +2113,9 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr std::list<CTransactionRef> lRemovedTxn; - if (!AlreadyHave(inv) && AcceptToMemoryPool(mempool, state, ptx, true, &fMissingInputs, &lRemovedTxn)) { - mempool.check(pcoinsTip); + if (!AlreadyHave(inv) && + AcceptToMemoryPool(mempool, state, ptx, &fMissingInputs, &lRemovedTxn, false /* bypass_limits */, 0 /* nAbsurdFee */)) { + mempool.check(pcoinsTip.get()); RelayTransaction(tx, connman); for (unsigned int i = 0; i < tx.vout.size(); i++) { vWorkQueue.emplace_back(inv.hash, i); @@ -1833,7 +2152,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr if (setMisbehaving.count(fromPeer)) continue; - if (AcceptToMemoryPool(mempool, stateDummy, porphanTx, true, &fMissingInputs2, &lRemovedTxn)) { + if (AcceptToMemoryPool(mempool, stateDummy, porphanTx, &fMissingInputs2, &lRemovedTxn, false /* bypass_limits */, 0 /* nAbsurdFee */)) { LogPrint(BCLog::MEMPOOL, " accepted orphan tx %s\n", orphanHash.ToString()); RelayTransaction(orphanTx, connman); for (unsigned int i = 0; i < orphanTx.vout.size(); i++) { @@ -1863,7 +2182,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr recentRejects->insert(orphanHash); } } - mempool.check(pcoinsTip); + mempool.check(pcoinsTip.get()); } } @@ -1889,7 +2208,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr AddOrphanTx(ptx, pfrom->GetId()); // DoS prevention: do not allow mapOrphanTransactions to grow unbounded - unsigned int nMaxOrphanTx = (unsigned int)std::max((int64_t)0, GetArg("-maxorphantx", DEFAULT_MAX_ORPHAN_TRANSACTIONS)); + unsigned int nMaxOrphanTx = (unsigned int)std::max((int64_t)0, gArgs.GetArg("-maxorphantx", DEFAULT_MAX_ORPHAN_TRANSACTIONS)); unsigned int nEvicted = LimitOrphanTxSize(nMaxOrphanTx); if (nEvicted > 0) { LogPrint(BCLog::MEMPOOL, "mapOrphan overflow, removed %u tx\n", nEvicted); @@ -1914,7 +2233,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr AddToCompactExtraTransactions(ptx); } - if (pfrom->fWhitelisted && GetBoolArg("-whitelistforcerelay", DEFAULT_WHITELISTFORCERELAY)) { + if (pfrom->fWhitelisted && gArgs.GetBoolArg("-whitelistforcerelay", DEFAULT_WHITELISTFORCERELAY)) { // Always relay transactions received from whitelisted peers, even // if they were already in the mempool or rejected from it due // to policy, allowing the node to function as a gateway for @@ -1943,7 +2262,7 @@ 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); @@ -1957,27 +2276,35 @@ 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 = NULL; + const CBlockIndex *pindex = nullptr; CValidationState state; if (!ProcessNewBlockHeaders({cmpctblock.header}, state, chainparams, &pindex)) { int nDoS; if (state.IsInvalid(nDoS)) { if (nDoS > 0) { + LogPrintf("Peer %d sent us invalid header via cmpctblock\n", pfrom->GetId()); LOCK(cs_main); Misbehaving(pfrom->GetId(), nDoS); + } else { + LogPrint(BCLog::NET, "Peer %d sent us invalid header via cmpctblock\n", pfrom->GetId()); } - LogPrintf("Peer %d sent us invalid header via cmpctblock\n", pfrom->GetId()); return true; } } @@ -1992,7 +2319,6 @@ 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) @@ -2005,6 +2331,14 @@ 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(); @@ -2018,7 +2352,7 @@ 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; } @@ -2027,8 +2361,6 @@ 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. @@ -2040,7 +2372,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr if (pindex->nHeight <= chainActive.Height() + 2) { if ((!fAlreadyInFlight && nodestate->nBlocksInFlight < MAX_BLOCKS_IN_TRANSIT_PER_PEER) || (fAlreadyInFlight && blockInFlightIt->second.first == pfrom->GetId())) { - std::list<QueuedBlock>::iterator* queuedBlockIt = NULL; + std::list<QueuedBlock>::iterator* queuedBlockIt = nullptr; if (!MarkBlockAsInFlight(pfrom->GetId(), pindex->GetBlockHash(), pindex, &queuedBlockIt)) { if (!(*queuedBlockIt)->partialBlock) (*queuedBlockIt)->partialBlock.reset(new PartiallyDownloadedBlock(&mempool)); @@ -2062,7 +2394,7 @@ 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; } @@ -2079,7 +2411,7 @@ 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 @@ -2105,14 +2437,10 @@ 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; } } @@ -2121,8 +2449,14 @@ 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 @@ -2132,10 +2466,22 @@ 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); - if (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 { + LOCK(cs_main); + mapBlockSource.erase(pblock->GetHash()); + } LOCK(cs_main); // hold cs_main for CBlockIndex::IsValid() if (pindex->IsValid(BLOCK_VALID_TRANSACTIONS)) { // Clear download state for this block, which is in @@ -2176,7 +2522,7 @@ 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. @@ -2209,9 +2555,17 @@ 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); - if (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 { + LOCK(cs_main); + mapBlockSource.erase(pblock->GetHash()); + } } } @@ -2233,136 +2587,12 @@ 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 = NULL; - { - 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. - BOOST_REVERSE_FOREACH(const CBlockIndex *pindex, 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 @@ -2372,11 +2602,7 @@ 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); @@ -2389,8 +2615,12 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr } bool fNewBlock = false; ProcessNewBlock(chainparams, pblock, forceProcessing, &fNewBlock); - if (fNewBlock) + if (fNewBlock) { pfrom->nLastBlockTime = GetTime(); + } else { + LOCK(cs_main); + mapBlockSource.erase(pblock->GetHash()); + } } @@ -2415,7 +2645,7 @@ 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); @@ -2431,7 +2661,7 @@ 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; @@ -2460,7 +2690,7 @@ 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)); } } @@ -2536,8 +2766,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr else { LOCK(pfrom->cs_filter); - delete pfrom->pfilter; - pfrom->pfilter = new CBloomFilter(filter); + pfrom->pfilter.reset(new CBloomFilter(filter)); pfrom->pfilter->UpdateEmptyFull(); pfrom->fRelayTxes = true; } @@ -2573,8 +2802,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr { LOCK(pfrom->cs_filter); if (pfrom->GetLocalServices() & NODE_BLOOM) { - delete pfrom->pfilter; - pfrom->pfilter = new CBloomFilter(); + pfrom->pfilter.reset(new CBloomFilter()); } pfrom->fRelayTxes = true; } @@ -2606,13 +2834,13 @@ 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(); @@ -2620,15 +2848,15 @@ 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) - LogPrintf("Warning: not punishing addnoded peer %s!\n", pnode->addr.ToString()); + else if (pnode->m_manual_connection) + LogPrintf("Warning: not punishing manually-connected peer %s!\n", pnode->addr.ToString()); else { pnode->fDisconnect = true; if (pnode->addr.IsLocal()) LogPrintf("Warning: not banning local peer %s!\n", pnode->addr.ToString()); else { - connman.Ban(pnode->addr, BanReasonNodeMisbehaving); + connman->Ban(pnode->addr, BanReasonNodeMisbehaving); } } return true; @@ -2636,7 +2864,7 @@ 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(); // @@ -2670,7 +2898,7 @@ 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()); @@ -2678,7 +2906,7 @@ bool ProcessMessages(CNode* pfrom, CConnman& connman, const std::atomic<bool>& i msg.SetVersion(pfrom->GetRecvVersion()); // Scan for message start if (memcmp(msg.hdr.pchMessageStart, chainparams.MessageStart(), CMessageHeader::MESSAGE_START_SIZE) != 0) { - LogPrintf("PROCESSMESSAGE: INVALID MESSAGESTART %s peer=%d\n", SanitizeString(msg.hdr.GetCommand()), pfrom->GetId()); + LogPrint(BCLog::NET, "PROCESSMESSAGE: INVALID MESSAGESTART %s peer=%d\n", SanitizeString(msg.hdr.GetCommand()), pfrom->GetId()); pfrom->fDisconnect = true; return false; } @@ -2687,7 +2915,7 @@ bool ProcessMessages(CNode* pfrom, CConnman& connman, const std::atomic<bool>& i CMessageHeader& hdr = msg.hdr; if (!hdr.IsValid(chainparams.MessageStart())) { - LogPrintf("PROCESSMESSAGE: ERRORS IN HEADER %s peer=%d\n", SanitizeString(hdr.GetCommand()), pfrom->GetId()); + LogPrint(BCLog::NET, "PROCESSMESSAGE: ERRORS IN HEADER %s peer=%d\n", SanitizeString(hdr.GetCommand()), pfrom->GetId()); return fMoreWork; } std::string strCommand = hdr.GetCommand(); @@ -2700,7 +2928,7 @@ bool ProcessMessages(CNode* pfrom, CConnman& connman, const std::atomic<bool>& i const uint256& hash = msg.GetMessageHash(); if (memcmp(hash.begin(), hdr.pchChecksum, CMessageHeader::CHECKSUM_SIZE) != 0) { - LogPrintf("%s(%s, %u bytes): CHECKSUM ERROR expected %s was %s\n", __func__, + LogPrint(BCLog::NET, "%s(%s, %u bytes): CHECKSUM ERROR expected %s was %s\n", __func__, SanitizeString(strCommand), nMessageSize, HexStr(hash.begin(), hash.begin()+CMessageHeader::CHECKSUM_SIZE), HexStr(hdr.pchChecksum, hdr.pchChecksum+CMessageHeader::CHECKSUM_SIZE)); @@ -2719,21 +2947,21 @@ 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 - LogPrintf("%s(%s, %u bytes): Exception '%s' caught, normally caused by a message being shorter than its stated length\n", __func__, SanitizeString(strCommand), nMessageSize, e.what()); + LogPrint(BCLog::NET, "%s(%s, %u bytes): Exception '%s' caught, normally caused by a message being shorter than its stated length\n", __func__, SanitizeString(strCommand), nMessageSize, e.what()); } else if (strstr(e.what(), "size too large")) { // Allow exceptions from over-long size - LogPrintf("%s(%s, %u bytes): Exception '%s' caught\n", __func__, SanitizeString(strCommand), nMessageSize, e.what()); + LogPrint(BCLog::NET, "%s(%s, %u bytes): Exception '%s' caught\n", __func__, SanitizeString(strCommand), nMessageSize, e.what()); } else if (strstr(e.what(), "non-canonical ReadCompactSize()")) { // Allow exceptions from non-canonical encoding - LogPrintf("%s(%s, %u bytes): Exception '%s' caught\n", __func__, SanitizeString(strCommand), nMessageSize, e.what()); + LogPrint(BCLog::NET, "%s(%s, %u bytes): Exception '%s' caught\n", __func__, SanitizeString(strCommand), nMessageSize, e.what()); } else { @@ -2743,11 +2971,11 @@ bool ProcessMessages(CNode* pfrom, CConnman& connman, const std::atomic<bool>& i catch (const std::exception& e) { PrintExceptionContinue(&e, "ProcessMessages()"); } catch (...) { - PrintExceptionContinue(NULL, "ProcessMessages()"); + PrintExceptionContinue(nullptr, "ProcessMessages()"); } if (!fRet) { - LogPrintf("%s(%s, %u bytes) FAILED peer=%d\n", __func__, SanitizeString(strCommand), nMessageSize, pfrom->GetId()); + LogPrint(BCLog::NET, "%s(%s, %u bytes) FAILED peer=%d\n", __func__, SanitizeString(strCommand), nMessageSize, pfrom->GetId()); } LOCK(cs_main); @@ -2756,11 +2984,141 @@ 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 { + assert(state.m_chain_sync.m_work_header); + 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; public: - CompareInvMempoolOrder(CTxMemPool *_mempool) + explicit CompareInvMempoolOrder(CTxMemPool *_mempool) { mp = _mempool; } @@ -2773,7 +3131,7 @@ 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(); { @@ -2805,11 +3163,11 @@ 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)); } } @@ -2844,21 +3202,21 @@ 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(); } // Start block sync - if (pindexBestHeader == NULL) + if (pindexBestHeader == nullptr) pindexBestHeader = chainActive.Tip(); bool fFetch = state.fPreferredDownload || (nPreferredDownload == 0 && !pto->fClient && !pto->fOneShot); // Download if this is a nice peer, or we have no nice peers and this one might do. if (!state.fSyncStarted && !pto->fClient && !fImporting && !fReindex) { @@ -2878,7 +3236,7 @@ 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())); } } @@ -2887,7 +3245,7 @@ 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); } // @@ -2906,7 +3264,7 @@ bool SendMessages(CNode* pto, CConnman& connman, const std::atomic<bool>& interr bool fRevertToInv = ((!state.fPreferHeaders && (!state.fPreferHeaderAndIDs || pto->vBlockHashesToAnnounce.size() > 1)) || pto->vBlockHashesToAnnounce.size() > MAX_BLOCKS_TO_ANNOUNCE); - const CBlockIndex *pBestIndex = NULL; // last header queued for delivery + const CBlockIndex *pBestIndex = nullptr; // last header queued for delivery ProcessBlockAvailability(pto->GetId()); // ensure pindexBestKnownBlock is up-to-date if (!fRevertToInv) { @@ -2923,7 +3281,7 @@ bool SendMessages(CNode* pto, CConnman& connman, const std::atomic<bool>& interr fRevertToInv = true; break; } - if (pBestIndex != NULL && pindex->pprev != pBestIndex) { + if (pBestIndex != nullptr && pindex->pprev != pBestIndex) { // This means that the list of blocks to announce don't // connect to each other. // This shouldn't really be possible to hit during @@ -2944,7 +3302,7 @@ bool SendMessages(CNode* pto, CConnman& connman, const std::atomic<bool>& interr vHeaders.push_back(pindex->GetBlockHeader()); } else if (PeerHasHeader(&state, pindex)) { continue; // keep looking for the first new block - } else if (pindex->pprev == NULL || PeerHasHeader(&state, pindex->pprev)) { + } else if (pindex->pprev == nullptr || PeerHasHeader(&state, pindex->pprev)) { // Peer doesn't have this header but they do have the prior one. // Start sending headers. fFoundStartingHeader = true; @@ -2971,10 +3329,10 @@ 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; } @@ -2984,7 +3342,7 @@ 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) { @@ -2997,7 +3355,7 @@ 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; @@ -3043,7 +3401,7 @@ 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(); } } @@ -3089,7 +3447,7 @@ 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(); } } @@ -3155,7 +3513,7 @@ 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); @@ -3163,7 +3521,7 @@ 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(); @@ -3222,6 +3580,9 @@ 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) @@ -3258,7 +3619,7 @@ 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 { @@ -3268,15 +3629,15 @@ 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 // // We don't want white listed peers to filter txs to us if we have -whitelistforcerelay - if (pto->nVersion >= FEEFILTER_VERSION && GetBoolArg("-feefilter", DEFAULT_FEEFILTER) && - !(pto->fWhitelisted && GetBoolArg("-whitelistforcerelay", DEFAULT_WHITELISTFORCERELAY))) { - CAmount currentFilter = mempool.GetMinFee(GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000).GetFeePerK(); + if (pto->nVersion >= FEEFILTER_VERSION && gArgs.GetBoolArg("-feefilter", DEFAULT_FEEFILTER) && + !(pto->fWhitelisted && gArgs.GetBoolArg("-whitelistforcerelay", DEFAULT_WHITELISTFORCERELAY))) { + CAmount currentFilter = mempool.GetMinFee(gArgs.GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000).GetFeePerK(); int64_t timeNow = GetTimeMicros(); if (timeNow > pto->nextSendTimeFeeFilter) { static CFeeRate default_feerate(DEFAULT_MIN_RELAY_TX_FEE); @@ -3285,7 +3646,7 @@ 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); |