diff options
Diffstat (limited to 'src/net_processing.cpp')
| -rw-r--r-- | src/net_processing.cpp | 271 |
1 files changed, 53 insertions, 218 deletions
diff --git a/src/net_processing.cpp b/src/net_processing.cpp index 951b8a1811..163c9c1f72 100644 --- a/src/net_processing.cpp +++ b/src/net_processing.cpp @@ -72,22 +72,19 @@ static constexpr std::chrono::minutes PING_INTERVAL{2}; static const unsigned int MAX_LOCATOR_SZ = 101; /** The maximum number of entries in an 'inv' protocol message */ static const unsigned int MAX_INV_SZ = 50000; -/** Maximum number of in-flight transactions from a peer */ -static constexpr int32_t MAX_PEER_TX_IN_FLIGHT = 100; +/** Maximum number of in-flight transaction requests from a peer. It is not a hard limit, but the threshold at which + * point the OVERLOADED_PEER_TX_DELAY kicks in. */ +static constexpr int32_t MAX_PEER_TX_REQUEST_IN_FLIGHT = 100; /** Maximum number of announced transactions from a peer */ static constexpr int32_t MAX_PEER_TX_ANNOUNCEMENTS = 2 * MAX_INV_SZ; -/** How many microseconds to delay requesting transactions via txids, if we have wtxid-relaying peers */ -static constexpr std::chrono::microseconds TXID_RELAY_DELAY{std::chrono::seconds{2}}; -/** How many microseconds to delay requesting transactions from inbound peers */ -static constexpr std::chrono::microseconds INBOUND_PEER_TX_DELAY{std::chrono::seconds{2}}; +/** How long to delay requesting transactions via txids, if we have wtxid-relaying peers */ +static constexpr auto TXID_RELAY_DELAY = std::chrono::seconds{2}; +/** How long to delay requesting transactions from non-preferred peers */ +static constexpr auto NONPREF_PEER_TX_DELAY = std::chrono::seconds{2}; +/** How long to delay requesting transactions from overloaded peers (see MAX_PEER_TX_REQUEST_IN_FLIGHT). */ +static constexpr auto OVERLOADED_PEER_TX_DELAY = std::chrono::seconds{2}; /** How long to wait (in microseconds) before downloading a transaction from an additional peer */ static constexpr std::chrono::microseconds GETDATA_TX_INTERVAL{std::chrono::seconds{60}}; -/** Maximum delay (in microseconds) for transaction requests to avoid biasing some peers over others. */ -static constexpr std::chrono::microseconds MAX_GETDATA_RANDOM_DELAY{std::chrono::seconds{2}}; -/** How long to wait (in microseconds) before expiring an in-flight getdata request to a peer */ -static constexpr std::chrono::microseconds TX_EXPIRY_INTERVAL{GETDATA_TX_INTERVAL * 10}; -static_assert(INBOUND_PEER_TX_DELAY >= MAX_GETDATA_RANDOM_DELAY, -"To preserve security, MAX_GETDATA_RANDOM_DELAY should not exceed INBOUND_PEER_DELAY"); /** Limit to avoid sending big packets. Not used in processing incoming GETDATA for compatibility */ static const unsigned int MAX_GETDATA_SZ = 1000; /** Number of blocks that can be requested at any given time from a single peer. */ @@ -375,69 +372,6 @@ struct CNodeState { //! Time of last new block announcement int64_t m_last_block_announcement; - /* - * State associated with transaction download. - * - * Tx download algorithm: - * - * When inv comes in, queue up (process_time, txid) inside the peer's - * CNodeState (m_tx_process_time) as long as m_tx_announced for the peer - * isn't too big (MAX_PEER_TX_ANNOUNCEMENTS). - * - * The process_time for a transaction is set to nNow for outbound peers, - * nNow + 2 seconds for inbound peers. This is the time at which we'll - * consider trying to request the transaction from the peer in - * SendMessages(). The delay for inbound peers is to allow outbound peers - * a chance to announce before we request from inbound peers, to prevent - * an adversary from using inbound connections to blind us to a - * transaction (InvBlock). - * - * When we call SendMessages() for a given peer, - * we will loop over the transactions in m_tx_process_time, looking - * at the transactions whose process_time <= nNow. We'll request each - * such transaction that we don't have already and that hasn't been - * requested from another peer recently, up until we hit the - * MAX_PEER_TX_IN_FLIGHT limit for the peer. Then we'll update - * g_already_asked_for for each requested txid, storing the time of the - * GETDATA request. We use g_already_asked_for to coordinate transaction - * requests amongst our peers. - * - * For transactions that we still need but we have already recently - * requested from some other peer, we'll reinsert (process_time, txid) - * back into the peer's m_tx_process_time at the point in the future at - * which the most recent GETDATA request would time out (ie - * GETDATA_TX_INTERVAL + the request time stored in g_already_asked_for). - * We add an additional delay for inbound peers, again to prefer - * attempting download from outbound peers first. - * We also add an extra small random delay up to 2 seconds - * to avoid biasing some peers over others. (e.g., due to fixed ordering - * of peer processing in ThreadMessageHandler). - * - * When we receive a transaction from a peer, we remove the txid from the - * peer's m_tx_in_flight set and from their recently announced set - * (m_tx_announced). We also clear g_already_asked_for for that entry, so - * that if somehow the transaction is not accepted but also not added to - * the reject filter, then we will eventually redownload from other - * peers. - */ - struct TxDownloadState { - /* Track when to attempt download of announced transactions (process - * time in micros -> txid) - */ - std::multimap<std::chrono::microseconds, GenTxid> m_tx_process_time; - - //! Store all the transactions a peer has recently announced - std::set<uint256> m_tx_announced; - - //! Store transactions which were requested by us, with timestamp - std::map<uint256, std::chrono::microseconds> m_tx_in_flight; - - //! Periodically check for stuck getdata requests - std::chrono::microseconds m_check_expiry_timer{0}; - }; - - TxDownloadState m_tx_download; - //! Whether this peer is an inbound connection bool m_is_inbound; @@ -478,9 +412,6 @@ struct CNodeState { } }; -// Keeps track of the time (in microseconds) when transactions were requested last time -limitedmap<uint256, std::chrono::microseconds> g_already_asked_for GUARDED_BY(cs_main)(MAX_INV_SZ); - /** Map maintaining per-node state. */ static std::map<NodeId, CNodeState> mapNodeState GUARDED_BY(cs_main); @@ -817,73 +748,34 @@ static void FindNextBlocksToDownload(NodeId nodeid, unsigned int count, std::vec } } -void EraseTxRequest(const GenTxid& gtxid) EXCLUSIVE_LOCKS_REQUIRED(cs_main) -{ - g_already_asked_for.erase(gtxid.GetHash()); -} - -std::chrono::microseconds GetTxRequestTime(const GenTxid& gtxid) EXCLUSIVE_LOCKS_REQUIRED(cs_main) -{ - auto it = g_already_asked_for.find(gtxid.GetHash()); - if (it != g_already_asked_for.end()) { - return it->second; - } - return {}; -} - -void UpdateTxRequestTime(const GenTxid& gtxid, std::chrono::microseconds request_time) EXCLUSIVE_LOCKS_REQUIRED(cs_main) -{ - auto it = g_already_asked_for.find(gtxid.GetHash()); - if (it == g_already_asked_for.end()) { - g_already_asked_for.insert(std::make_pair(gtxid.GetHash(), request_time)); - } else { - g_already_asked_for.update(it, request_time); - } -} - -std::chrono::microseconds CalculateTxGetDataTime(const GenTxid& gtxid, std::chrono::microseconds current_time, bool use_inbound_delay, bool use_txid_delay) EXCLUSIVE_LOCKS_REQUIRED(cs_main) -{ - std::chrono::microseconds process_time; - const auto last_request_time = GetTxRequestTime(gtxid); - // First time requesting this tx - if (last_request_time.count() == 0) { - process_time = current_time; - } else { - // Randomize the delay to avoid biasing some peers over others (such as due to - // fixed ordering of peer processing in ThreadMessageHandler) - process_time = last_request_time + GETDATA_TX_INTERVAL + GetRandMicros(MAX_GETDATA_RANDOM_DELAY); - } - - // We delay processing announcements from inbound peers - if (use_inbound_delay) process_time += INBOUND_PEER_TX_DELAY; - - // We delay processing announcements from peers that use txid-relay (instead of wtxid) - if (use_txid_delay) process_time += TXID_RELAY_DELAY; - - return process_time; -} +} // namespace -void RequestTx(CNodeState* state, const GenTxid& gtxid, std::chrono::microseconds current_time) EXCLUSIVE_LOCKS_REQUIRED(cs_main) +void PeerManager::AddTxAnnouncement(const CNode& node, const GenTxid& gtxid, std::chrono::microseconds current_time) { - CNodeState::TxDownloadState& peer_download_state = state->m_tx_download; - if (peer_download_state.m_tx_announced.size() >= MAX_PEER_TX_ANNOUNCEMENTS || - peer_download_state.m_tx_process_time.size() >= MAX_PEER_TX_ANNOUNCEMENTS || - peer_download_state.m_tx_announced.count(gtxid.GetHash())) { - // Too many queued announcements from this peer, or we already have - // this announcement + AssertLockHeld(::cs_main); // For m_txrequest + NodeId nodeid = node.GetId(); + if (m_txrequest.Count(nodeid) >= MAX_PEER_TX_ANNOUNCEMENTS) { + // Too many queued announcements from this peer return; } - peer_download_state.m_tx_announced.insert(gtxid.GetHash()); - - // Calculate the time to try requesting this transaction. Use - // fPreferredDownload as a proxy for outbound peers. - const auto process_time = CalculateTxGetDataTime(gtxid, current_time, !state->fPreferredDownload, !state->m_wtxid_relay && g_wtxid_relay_peers > 0); - - peer_download_state.m_tx_process_time.emplace(process_time, gtxid); + const CNodeState* state = State(nodeid); + + // Decide the TxRequestTracker parameters for this announcement: + // - "preferred": if fPreferredDownload is set (= outbound, or PF_NOBAN permission) + // - "reqtime": current time plus delays for: + // - NONPREF_PEER_TX_DELAY for announcements from non-preferred connections + // - TXID_RELAY_DELAY for announcements from txid peers while wtxid peers are available + // - OVERLOADED_PEER_TX_DELAY for announcements from peers which have at least + // MAX_PEER_TX_REQUEST_IN_FLIGHT requests in flight. + auto delay = std::chrono::microseconds{0}; + const bool preferred = state->fPreferredDownload; + if (!preferred) delay += NONPREF_PEER_TX_DELAY; + if (!state->m_wtxid_relay && g_wtxid_relay_peers > 0) delay += TXID_RELAY_DELAY; + const bool overloaded = m_txrequest.CountInFlight(nodeid) >= MAX_PEER_TX_REQUEST_IN_FLIGHT; + if (overloaded) delay += OVERLOADED_PEER_TX_DELAY; + m_txrequest.ReceivedInv(nodeid, gtxid, preferred, current_time + delay); } -} // namespace - // This function is used for testing the stale tip eviction logic, see // denialofservice_tests.cpp void UpdateLastBlockAnnounceTime(NodeId node, int64_t time_in_seconds) @@ -900,6 +792,7 @@ void PeerManager::InitializeNode(CNode *pnode) { { LOCK(cs_main); mapNodeState.emplace_hint(mapNodeState.end(), std::piecewise_construct, std::forward_as_tuple(nodeid), std::forward_as_tuple(addr, pnode->IsInboundConn(), pnode->IsManualConn())); + assert(m_txrequest.Count(nodeid) == 0); } { PeerRef peer = std::make_shared<Peer>(nodeid); @@ -957,6 +850,7 @@ void PeerManager::FinalizeNode(NodeId nodeid, bool& fUpdateConnectionTime) { mapBlocksInFlight.erase(entry.hash); } EraseOrphansFor(nodeid); + m_txrequest.DisconnectedPeer(nodeid); nPreferredDownload -= state->fPreferredDownload; nPeersWithValidatedDownloads -= (state->nBlocksInFlightValidHeaders != 0); assert(nPeersWithValidatedDownloads >= 0); @@ -974,6 +868,7 @@ void PeerManager::FinalizeNode(NodeId nodeid, bool& fUpdateConnectionTime) { assert(nPeersWithValidatedDownloads == 0); assert(g_outbound_peers_with_protect_from_disconnect == 0); assert(g_wtxid_relay_peers == 0); + assert(m_txrequest.Size() == 0); } LogPrint(BCLog::NET, "Cleared nodestate for peer=%d\n", nodeid); } @@ -2769,7 +2664,7 @@ void PeerManager::ProcessMessage(CNode& pfrom, const std::string& msg_type, CDat pfrom.fDisconnect = true; return; } else if (!fAlreadyHave && !m_chainman.ActiveChainstate().IsInitialBlockDownload()) { - RequestTx(State(pfrom.GetId()), gtxid, current_time); + AddTxAnnouncement(pfrom, gtxid, current_time); } } else { LogPrint(BCLog::NET, "Unknown inv type \"%s\" received from peer=%d\n", inv.ToString(), pfrom.GetId()); @@ -3023,11 +2918,8 @@ void PeerManager::ProcessMessage(CNode& pfrom, const std::string& msg_type, CDat TxValidationState state; - for (const GenTxid& gtxid : {GenTxid(false, txid), GenTxid(true, wtxid)}) { - nodestate->m_tx_download.m_tx_announced.erase(gtxid.GetHash()); - nodestate->m_tx_download.m_tx_in_flight.erase(gtxid.GetHash()); - EraseTxRequest(gtxid); - } + m_txrequest.ReceivedResponse(pfrom.GetId(), txid); + if (tx.HasWitness()) m_txrequest.ReceivedResponse(pfrom.GetId(), wtxid); std::list<CTransactionRef> lRemovedTxn; @@ -3101,7 +2993,7 @@ void PeerManager::ProcessMessage(CNode& pfrom, const std::string& msg_type, CDat // protocol for getting all unconfirmed parents. const GenTxid gtxid{/* is_wtxid=*/false, parent_txid}; pfrom.AddKnownTx(parent_txid); - if (!AlreadyHaveTx(gtxid, m_mempool)) RequestTx(State(pfrom.GetId()), gtxid, current_time); + if (!AlreadyHaveTx(gtxid, m_mempool)) AddTxAnnouncement(pfrom, gtxid, current_time); } AddOrphanTx(ptx, pfrom.GetId()); @@ -3789,24 +3681,15 @@ void PeerManager::ProcessMessage(CNode& pfrom, const std::string& msg_type, CDat } if (msg_type == NetMsgType::NOTFOUND) { - // Remove the NOTFOUND transactions from the peer - LOCK(cs_main); - CNodeState *state = State(pfrom.GetId()); std::vector<CInv> vInv; vRecv >> vInv; - if (vInv.size() <= MAX_PEER_TX_IN_FLIGHT + MAX_BLOCKS_IN_TRANSIT_PER_PEER) { + if (vInv.size() <= MAX_PEER_TX_ANNOUNCEMENTS + MAX_BLOCKS_IN_TRANSIT_PER_PEER) { + LOCK(::cs_main); for (CInv &inv : vInv) { if (inv.IsGenTxMsg()) { - // If we receive a NOTFOUND message for a txid we requested, erase - // it from our data structures for this peer. - auto in_flight_it = state->m_tx_download.m_tx_in_flight.find(inv.hash); - if (in_flight_it == state->m_tx_download.m_tx_in_flight.end()) { - // Skip any further work if this is a spurious NOTFOUND - // message. - continue; - } - state->m_tx_download.m_tx_in_flight.erase(in_flight_it); - state->m_tx_download.m_tx_announced.erase(inv.hash); + // If we receive a NOTFOUND message for a tx we requested, mark the announcement for it as + // completed in TxRequestTracker. + m_txrequest.ReceivedResponse(pfrom.GetId(), inv.hash); } } } @@ -4581,67 +4464,19 @@ bool PeerManager::SendMessages(CNode* pto) // // Message: getdata (non-blocks) // - - // For robustness, expire old requests after a long timeout, so that - // we can resume downloading transactions from a peer even if they - // were unresponsive in the past. - // Eventually we should consider disconnecting peers, but this is - // conservative. - if (state.m_tx_download.m_check_expiry_timer <= current_time) { - for (auto it=state.m_tx_download.m_tx_in_flight.begin(); it != state.m_tx_download.m_tx_in_flight.end();) { - if (it->second <= current_time - TX_EXPIRY_INTERVAL) { - LogPrint(BCLog::NET, "timeout of inflight tx %s from peer=%d\n", it->first.ToString(), pto->GetId()); - state.m_tx_download.m_tx_announced.erase(it->first); - state.m_tx_download.m_tx_in_flight.erase(it++); - } else { - ++it; - } - } - // On average, we do this check every TX_EXPIRY_INTERVAL. Randomize - // so that we're not doing this for all peers at the same time. - state.m_tx_download.m_check_expiry_timer = current_time + TX_EXPIRY_INTERVAL / 2 + GetRandMicros(TX_EXPIRY_INTERVAL); - } - - auto& tx_process_time = state.m_tx_download.m_tx_process_time; - while (!tx_process_time.empty() && tx_process_time.begin()->first <= current_time && state.m_tx_download.m_tx_in_flight.size() < MAX_PEER_TX_IN_FLIGHT) { - const GenTxid gtxid = tx_process_time.begin()->second; - // Erase this entry from tx_process_time (it may be added back for - // processing at a later time, see below) - tx_process_time.erase(tx_process_time.begin()); - CInv inv(gtxid.IsWtxid() ? MSG_WTX : (MSG_TX | GetFetchFlags(*pto)), gtxid.GetHash()); - if (!AlreadyHaveTx(ToGenTxid(inv), m_mempool)) { - // If this transaction was last requested more than 1 minute ago, - // then request. - const auto last_request_time = GetTxRequestTime(gtxid); - if (last_request_time <= current_time - GETDATA_TX_INTERVAL) { - LogPrint(BCLog::NET, "Requesting %s peer=%d\n", inv.ToString(), pto->GetId()); - vGetData.push_back(inv); - if (vGetData.size() >= MAX_GETDATA_SZ) { - m_connman.PushMessage(pto, msgMaker.Make(NetMsgType::GETDATA, vGetData)); - vGetData.clear(); - } - UpdateTxRequestTime(gtxid, current_time); - state.m_tx_download.m_tx_in_flight.emplace(gtxid.GetHash(), current_time); - } else { - // This transaction is in flight from someone else; queue - // up processing to happen after the download times out - // (with a slight delay for inbound peers, to prefer - // requests to outbound peers). - // Don't apply the txid-delay to re-requests of a - // transaction; the heuristic of delaying requests to - // txid-relay peers is to save bandwidth on initial - // announcement of a transaction, and doesn't make sense - // for a followup request if our first peer times out (and - // would open us up to an attacker using inbound - // wtxid-relay to prevent us from requesting transactions - // from outbound txid-relay peers). - const auto next_process_time = CalculateTxGetDataTime(gtxid, current_time, !state.fPreferredDownload, false); - tx_process_time.emplace(next_process_time, gtxid); + for (const GenTxid& gtxid : m_txrequest.GetRequestable(pto->GetId(), current_time)) { + if (!AlreadyHaveTx(gtxid, m_mempool)) { + LogPrint(BCLog::NET, "Requesting %s %s peer=%d\n", gtxid.IsWtxid() ? "wtx" : "tx", + gtxid.GetHash().ToString(), pto->GetId()); + vGetData.emplace_back(gtxid.IsWtxid() ? MSG_WTX : (MSG_TX | GetFetchFlags(*pto)), gtxid.GetHash()); + if (vGetData.size() >= MAX_GETDATA_SZ) { + m_connman.PushMessage(pto, msgMaker.Make(NetMsgType::GETDATA, vGetData)); + vGetData.clear(); } + m_txrequest.RequestedTx(pto->GetId(), gtxid.GetHash(), current_time + GETDATA_TX_INTERVAL); } else { // We have already seen this transaction, no need to download. - state.m_tx_download.m_tx_announced.erase(gtxid.GetHash()); - state.m_tx_download.m_tx_in_flight.erase(gtxid.GetHash()); + m_txrequest.ForgetTxHash(gtxid.GetHash()); } } |