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Diffstat (limited to 'src/net_processing.cpp')
| -rw-r--r-- | src/net_processing.cpp | 5118 |
1 files changed, 5118 insertions, 0 deletions
diff --git a/src/net_processing.cpp b/src/net_processing.cpp new file mode 100644 index 0000000000..cb0e8c88f8 --- /dev/null +++ b/src/net_processing.cpp @@ -0,0 +1,5118 @@ +// Copyright (c) 2009-2010 Satoshi Nakamoto +// Copyright (c) 2009-2021 The Bitcoin Core developers +// 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 <banman.h> +#include <blockencodings.h> +#include <blockfilter.h> +#include <chainparams.h> +#include <consensus/amount.h> +#include <consensus/validation.h> +#include <deploymentstatus.h> +#include <hash.h> +#include <index/blockfilterindex.h> +#include <merkleblock.h> +#include <netbase.h> +#include <netmessagemaker.h> +#include <node/blockstorage.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 <streams.h> +#include <sync.h> +#include <tinyformat.h> +#include <txmempool.h> +#include <txorphanage.h> +#include <txrequest.h> +#include <util/check.h> // For NDEBUG compile time check +#include <util/strencodings.h> +#include <util/system.h> +#include <util/trace.h> +#include <validation.h> + +#include <algorithm> +#include <atomic> +#include <chrono> +#include <future> +#include <memory> +#include <optional> +#include <typeinfo> + +using node::ReadBlockFromDisk; +using node::ReadRawBlockFromDisk; +using node::fImporting; +using node::fPruneMode; +using node::fReindex; + +/** How long to cache transactions in mapRelay for normal relay */ +static constexpr auto RELAY_TX_CACHE_TIME = 15min; +/** How long a transaction has to be in the mempool before it can unconditionally be relayed (even when not in mapRelay). */ +static constexpr auto UNCONDITIONAL_RELAY_DELAY = 2min; +/** Headers download timeout. + * Timeout = base + per_header * (expected number of headers) */ +static constexpr auto HEADERS_DOWNLOAD_TIMEOUT_BASE = 15min; +static constexpr auto HEADERS_DOWNLOAD_TIMEOUT_PER_HEADER = 1ms; +/** Protect at least this many outbound peers from disconnection due to slow/ + * behind headers chain. + */ +static constexpr int32_t MAX_OUTBOUND_PEERS_TO_PROTECT_FROM_DISCONNECT = 4; +/** Timeout for (unprotected) outbound peers to sync to our chainwork */ +static constexpr auto CHAIN_SYNC_TIMEOUT{20min}; +/** How frequently to check for stale tips */ +static constexpr auto STALE_CHECK_INTERVAL{10min}; +/** How frequently to check for extra outbound peers and disconnect */ +static constexpr auto EXTRA_PEER_CHECK_INTERVAL{45s}; +/** Minimum time an outbound-peer-eviction candidate must be connected for, in order to evict */ +static constexpr auto MINIMUM_CONNECT_TIME{30s}; +/** SHA256("main address relay")[0:8] */ +static constexpr uint64_t RANDOMIZER_ID_ADDRESS_RELAY = 0x3cac0035b5866b90ULL; +/// 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 constexpr 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 constexpr int HISTORICAL_BLOCK_AGE = 7 * 24 * 60 * 60; +/** Time between pings automatically sent out for latency probing and keepalive */ +static constexpr auto PING_INTERVAL{2min}; +/** The maximum number of entries in a locator */ +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 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 transactions to consider for requesting, per peer. It provides a reasonable DoS limit to + * per-peer memory usage spent on announcements, while covering peers continuously sending INVs at the maximum + * rate (by our own policy, see INVENTORY_BROADCAST_PER_SECOND) for several minutes, while not receiving + * the actual transaction (from any peer) in response to requests for them. */ +static constexpr int32_t MAX_PEER_TX_ANNOUNCEMENTS = 5000; +/** How long to delay requesting transactions via txids, if we have wtxid-relaying peers */ +static constexpr auto TXID_RELAY_DELAY{2s}; +/** How long to delay requesting transactions from non-preferred peers */ +static constexpr auto NONPREF_PEER_TX_DELAY{2s}; +/** How long to delay requesting transactions from overloaded peers (see MAX_PEER_TX_REQUEST_IN_FLIGHT). */ +static constexpr auto OVERLOADED_PEER_TX_DELAY{2s}; +/** How long to wait before downloading a transaction from an additional peer */ +static constexpr auto GETDATA_TX_INTERVAL{60s}; +/** 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. */ +static const int MAX_BLOCKS_IN_TRANSIT_PER_PEER = 16; +/** Time during which a peer must stall block download progress before being disconnected. */ +static constexpr auto BLOCK_STALLING_TIMEOUT{2s}; +/** Number of headers sent in one getheaders result. We rely on the assumption that if a peer sends + * less than this number, we reached its tip. Changing this value is a protocol upgrade. */ +static const unsigned int MAX_HEADERS_RESULTS = 2000; +/** Maximum depth of blocks we're willing to serve as compact blocks to peers + * when requested. For older blocks, a regular BLOCK response will be sent. */ +static const int MAX_CMPCTBLOCK_DEPTH = 5; +/** Maximum depth of blocks we're willing to respond to GETBLOCKTXN requests for. */ +static const int MAX_BLOCKTXN_DEPTH = 10; +/** Size of the "block download window": how far ahead of our current height do we fetch? + * Larger windows tolerate larger download speed differences between peer, but increase the potential + * degree of disordering of blocks on disk (which make reindexing and pruning harder). We'll probably + * want to make this a per-peer adaptive value at some point. */ +static const unsigned int BLOCK_DOWNLOAD_WINDOW = 1024; +/** Block download timeout base, expressed in multiples of the block interval (i.e. 10 min) */ +static constexpr double BLOCK_DOWNLOAD_TIMEOUT_BASE = 1; +/** Additional block download timeout per parallel downloading peer (i.e. 5 min) */ +static constexpr double BLOCK_DOWNLOAD_TIMEOUT_PER_PEER = 0.5; +/** Maximum number of headers to announce when relaying blocks with headers message.*/ +static const unsigned int MAX_BLOCKS_TO_ANNOUNCE = 8; +/** Maximum number of unconnecting headers announcements before DoS score */ +static const int MAX_UNCONNECTING_HEADERS = 10; +/** Minimum blocks required to signal NODE_NETWORK_LIMITED */ +static const unsigned int NODE_NETWORK_LIMITED_MIN_BLOCKS = 288; +/** Average delay between local address broadcasts */ +static constexpr auto AVG_LOCAL_ADDRESS_BROADCAST_INTERVAL{24h}; +/** Average delay between peer address broadcasts */ +static constexpr auto AVG_ADDRESS_BROADCAST_INTERVAL{30s}; +/** Delay between rotating the peers we relay a particular address to */ +static constexpr auto ROTATE_ADDR_RELAY_DEST_INTERVAL{24h}; +/** Average delay between trickled inventory transmissions for inbound peers. + * Blocks and peers with NetPermissionFlags::NoBan permission bypass this. */ +static constexpr auto INBOUND_INVENTORY_BROADCAST_INTERVAL{5s}; +/** Average delay between trickled inventory transmissions for outbound peers. + * Use a smaller delay as there is less privacy concern for them. + * Blocks and peers with NetPermissionFlags::NoBan permission bypass this. */ +static constexpr auto OUTBOUND_INVENTORY_BROADCAST_INTERVAL{2s}; +/** Maximum rate of inventory items to send per second. + * Limits the impact of low-fee transaction floods. */ +static constexpr unsigned int INVENTORY_BROADCAST_PER_SECOND = 7; +/** Maximum number of inventory items to send per transmission. */ +static constexpr unsigned int INVENTORY_BROADCAST_MAX = INVENTORY_BROADCAST_PER_SECOND * count_seconds(INBOUND_INVENTORY_BROADCAST_INTERVAL); +/** The number of most recently announced transactions a peer can request. */ +static constexpr unsigned int INVENTORY_MAX_RECENT_RELAY = 3500; +/** Verify that INVENTORY_MAX_RECENT_RELAY is enough to cache everything typically + * relayed before unconditional relay from the mempool kicks in. This is only a + * lower bound, and it should be larger to account for higher inv rate to outbound + * peers, and random variations in the broadcast mechanism. */ +static_assert(INVENTORY_MAX_RECENT_RELAY >= INVENTORY_BROADCAST_PER_SECOND * UNCONDITIONAL_RELAY_DELAY / std::chrono::seconds{1}, "INVENTORY_RELAY_MAX too low"); +/** Average delay between feefilter broadcasts in seconds. */ +static constexpr auto AVG_FEEFILTER_BROADCAST_INTERVAL{10min}; +/** Maximum feefilter broadcast delay after significant change. */ +static constexpr auto MAX_FEEFILTER_CHANGE_DELAY{5min}; +/** Maximum number of compact filters that may be requested with one getcfilters. See BIP 157. */ +static constexpr uint32_t MAX_GETCFILTERS_SIZE = 1000; +/** Maximum number of cf hashes that may be requested with one getcfheaders. See BIP 157. */ +static constexpr uint32_t MAX_GETCFHEADERS_SIZE = 2000; +/** the maximum percentage of addresses from our addrman to return in response to a getaddr message. */ +static constexpr size_t MAX_PCT_ADDR_TO_SEND = 23; +/** The maximum number of address records permitted in an ADDR message. */ +static constexpr size_t MAX_ADDR_TO_SEND{1000}; +/** The maximum rate of address records we're willing to process on average. Can be bypassed using + * the NetPermissionFlags::Addr permission. */ +static constexpr double MAX_ADDR_RATE_PER_SECOND{0.1}; +/** The soft limit of the address processing token bucket (the regular MAX_ADDR_RATE_PER_SECOND + * based increments won't go above this, but the MAX_ADDR_TO_SEND increment following GETADDR + * is exempt from this limit). */ +static constexpr size_t MAX_ADDR_PROCESSING_TOKEN_BUCKET{MAX_ADDR_TO_SEND}; + +// Internal stuff +namespace { +/** Blocks that are in flight, and that are in the queue to be downloaded. */ +struct QueuedBlock { + /** BlockIndex. We must have this since we only request blocks when we've already validated the header. */ + const CBlockIndex* pindex; + /** Optional, used for CMPCTBLOCK downloads */ + std::unique_ptr<PartiallyDownloadedBlock> partialBlock; +}; + +/** + * Data structure for an individual peer. This struct is not protected by + * cs_main since it does not contain validation-critical data. + * + * Memory is owned by shared pointers and this object is destructed when + * the refcount drops to zero. + * + * Mutexes inside this struct must not be held when locking m_peer_mutex. + * + * TODO: move most members from CNodeState to this structure. + * TODO: move remaining application-layer data members from CNode to this structure. + */ +struct Peer { + /** Same id as the CNode object for this peer */ + const NodeId m_id{0}; + + /** Protects misbehavior data members */ + Mutex m_misbehavior_mutex; + /** Accumulated misbehavior score for this peer */ + int m_misbehavior_score GUARDED_BY(m_misbehavior_mutex){0}; + /** Whether this peer should be disconnected and marked as discouraged (unless it has NetPermissionFlags::NoBan permission). */ + bool m_should_discourage GUARDED_BY(m_misbehavior_mutex){false}; + + /** Protects block inventory data members */ + Mutex m_block_inv_mutex; + /** List of blocks that we'll announce via an `inv` message. + * There is no final sorting before sending, as they are always sent + * immediately and in the order requested. */ + std::vector<uint256> m_blocks_for_inv_relay GUARDED_BY(m_block_inv_mutex); + /** Unfiltered list of blocks that we'd like to announce via a `headers` + * message. If we can't announce via a `headers` message, we'll fall back to + * announcing via `inv`. */ + std::vector<uint256> m_blocks_for_headers_relay GUARDED_BY(m_block_inv_mutex); + /** The final block hash that we sent in an `inv` message to this peer. + * When the peer requests this block, we send an `inv` message to trigger + * the peer to request the next sequence of block hashes. + * Most peers use headers-first syncing, which doesn't use this mechanism */ + uint256 m_continuation_block GUARDED_BY(m_block_inv_mutex) {}; + + /** This peer's reported block height when we connected */ + std::atomic<int> m_starting_height{-1}; + + /** The pong reply we're expecting, or 0 if no pong expected. */ + std::atomic<uint64_t> m_ping_nonce_sent{0}; + /** When the last ping was sent, or 0 if no ping was ever sent */ + std::atomic<std::chrono::microseconds> m_ping_start{0us}; + /** Whether a ping has been requested by the user */ + std::atomic<bool> m_ping_queued{false}; + + /** Whether this peer relays txs via wtxid */ + std::atomic<bool> m_wtxid_relay{false}; + + struct TxRelay { + mutable RecursiveMutex m_bloom_filter_mutex; + // We use m_relay_txs for two purposes - + // a) it allows us to not relay tx invs before receiving the peer's version message + // b) the peer may tell us in its version message that we should not relay tx invs + // unless it loads a bloom filter. + bool m_relay_txs GUARDED_BY(m_bloom_filter_mutex){false}; + std::unique_ptr<CBloomFilter> m_bloom_filter PT_GUARDED_BY(m_bloom_filter_mutex) GUARDED_BY(m_bloom_filter_mutex){nullptr}; + + mutable RecursiveMutex m_tx_inventory_mutex; + CRollingBloomFilter m_tx_inventory_known_filter GUARDED_BY(m_tx_inventory_mutex){50000, 0.000001}; + // Set of transaction ids we still have to announce. + // They are sorted by the mempool before relay, so the order is not important. + std::set<uint256> m_tx_inventory_to_send; + // Used for BIP35 mempool sending + bool m_send_mempool GUARDED_BY(m_tx_inventory_mutex){false}; + // Last time a "MEMPOOL" request was serviced. + std::atomic<std::chrono::seconds> m_last_mempool_req{0s}; + std::chrono::microseconds m_next_inv_send_time{0}; + + /** Minimum fee rate with which to filter inv's to this node */ + std::atomic<CAmount> m_fee_filter_received{0}; + CAmount m_fee_filter_sent{0}; + std::chrono::microseconds m_next_send_feefilter{0}; + }; + + /** Transaction relay data. Will be a nullptr if we're not relaying + * transactions with this peer (e.g. if it's a block-relay-only peer) */ + std::unique_ptr<TxRelay> m_tx_relay; + + /** A vector of addresses to send to the peer, limited to MAX_ADDR_TO_SEND. */ + std::vector<CAddress> m_addrs_to_send; + /** Probabilistic filter to track recent addr messages relayed with this + * peer. Used to avoid relaying redundant addresses to this peer. + * + * We initialize this filter for outbound peers (other than + * block-relay-only connections) or when an inbound peer sends us an + * address related message (ADDR, ADDRV2, GETADDR). + * + * Presence of this filter must correlate with m_addr_relay_enabled. + **/ + std::unique_ptr<CRollingBloomFilter> m_addr_known; + /** Whether we are participating in address relay with this connection. + * + * We set this bool to true for outbound peers (other than + * block-relay-only connections), or when an inbound peer sends us an + * address related message (ADDR, ADDRV2, GETADDR). + * + * We use this bool to decide whether a peer is eligible for gossiping + * addr messages. This avoids relaying to peers that are unlikely to + * forward them, effectively blackholing self announcements. Reasons + * peers might support addr relay on the link include that they connected + * to us as a block-relay-only peer or they are a light client. + * + * This field must correlate with whether m_addr_known has been + * initialized.*/ + std::atomic_bool m_addr_relay_enabled{false}; + /** Whether a getaddr request to this peer is outstanding. */ + bool m_getaddr_sent{false}; + /** Guards address sending timers. */ + mutable Mutex m_addr_send_times_mutex; + /** Time point to send the next ADDR message to this peer. */ + std::chrono::microseconds m_next_addr_send GUARDED_BY(m_addr_send_times_mutex){0}; + /** Time point to possibly re-announce our local address to this peer. */ + std::chrono::microseconds m_next_local_addr_send GUARDED_BY(m_addr_send_times_mutex){0}; + /** Whether the peer has signaled support for receiving ADDRv2 (BIP155) + * messages, indicating a preference to receive ADDRv2 instead of ADDR ones. */ + std::atomic_bool m_wants_addrv2{false}; + /** Whether this peer has already sent us a getaddr message. */ + bool m_getaddr_recvd{false}; + /** Number of addresses that can be processed from this peer. Start at 1 to + * permit self-announcement. */ + double m_addr_token_bucket{1.0}; + /** When m_addr_token_bucket was last updated */ + std::chrono::microseconds m_addr_token_timestamp{GetTime<std::chrono::microseconds>()}; + /** Total number of addresses that were dropped due to rate limiting. */ + std::atomic<uint64_t> m_addr_rate_limited{0}; + /** Total number of addresses that were processed (excludes rate-limited ones). */ + std::atomic<uint64_t> m_addr_processed{0}; + + /** Set of txids to reconsider once their parent transactions have been accepted **/ + std::set<uint256> m_orphan_work_set GUARDED_BY(g_cs_orphans); + + /** Protects m_getdata_requests **/ + Mutex m_getdata_requests_mutex; + /** Work queue of items requested by this peer **/ + std::deque<CInv> m_getdata_requests GUARDED_BY(m_getdata_requests_mutex); + + explicit Peer(NodeId id, bool tx_relay) + : m_id(id) + , m_tx_relay(tx_relay ? std::make_unique<TxRelay>() : nullptr) + {} +}; + +using PeerRef = std::shared_ptr<Peer>; + +/** + * Maintain validation-specific state about nodes, protected by cs_main, instead + * by CNode's own locks. This simplifies asynchronous operation, where + * processing of incoming data is done after the ProcessMessage call returns, + * and we're no longer holding the node's locks. + */ +struct CNodeState { + //! The best known block we know this peer has announced. + const CBlockIndex* pindexBestKnownBlock{nullptr}; + //! The hash of the last unknown block this peer has announced. + uint256 hashLastUnknownBlock{}; + //! The last full block we both have. + const CBlockIndex* pindexLastCommonBlock{nullptr}; + //! The best header we have sent our peer. + const CBlockIndex* pindexBestHeaderSent{nullptr}; + //! Length of current-streak of unconnecting headers announcements + int nUnconnectingHeaders{0}; + //! Whether we've started headers synchronization with this peer. + bool fSyncStarted{false}; + //! When to potentially disconnect peer for stalling headers download + std::chrono::microseconds m_headers_sync_timeout{0us}; + //! Since when we're stalling block download progress (in microseconds), or 0. + std::chrono::microseconds m_stalling_since{0us}; + std::list<QueuedBlock> vBlocksInFlight; + //! When the first entry in vBlocksInFlight started downloading. Don't care when vBlocksInFlight is empty. + std::chrono::microseconds m_downloading_since{0us}; + int nBlocksInFlight{0}; + //! Whether we consider this a preferred download peer. + bool fPreferredDownload{false}; + //! Whether this peer wants invs or headers (when possible) for block announcements. + bool fPreferHeaders{false}; + //! Whether this peer wants invs or cmpctblocks (when possible) for block announcements. + bool fPreferHeaderAndIDs{false}; + /** + * Whether this peer will send us cmpctblocks if we request them. + * This is not used to gate request logic, as we really only care about fSupportsDesiredCmpctVersion, + * but is used as a flag to "lock in" the version of compact blocks (fWantsCmpctWitness) we send. + */ + bool fProvidesHeaderAndIDs{false}; + //! Whether this peer can give us witnesses + bool fHaveWitness{false}; + //! Whether this peer wants witnesses in cmpctblocks/blocktxns + bool fWantsCmpctWitness{false}; + /** + * If we've announced NODE_WITNESS to this peer: whether the peer sends witnesses in cmpctblocks/blocktxns, + * otherwise: whether this peer sends non-witnesses in cmpctblocks/blocktxns. + */ + bool fSupportsDesiredCmpctVersion{false}; + + /** State used to enforce CHAIN_SYNC_TIMEOUT and EXTRA_PEER_CHECK_INTERVAL logic. + * + * Both are only in effect for outbound, non-manual, non-protected connections. + * Any peer protected (m_protect = true) is not chosen for eviction. A peer is + * marked as protected if all of these are true: + * - its connection type is IsBlockOnlyConn() == false + * - it gave us a valid connecting header + * - we haven't reached MAX_OUTBOUND_PEERS_TO_PROTECT_FROM_DISCONNECT yet + * - its chain tip has at least as much work as ours + * + * CHAIN_SYNC_TIMEOUT: if a peer's best known block has less work than our tip, + * set a timeout CHAIN_SYNC_TIMEOUT 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. + * + * EXTRA_PEER_CHECK_INTERVAL: after each interval, if we have too many outbound peers, + * drop the outbound one that least recently announced us a new block. + */ + struct ChainSyncTimeoutState { + //! A timeout used for checking whether our peer has sufficiently synced + std::chrono::seconds m_timeout{0s}; + //! A header with the work we require on our peer's chain + const CBlockIndex* m_work_header{nullptr}; + //! After timeout is reached, set to true after sending getheaders + bool m_sent_getheaders{false}; + //! Whether this peer is protected from disconnection due to a bad/slow chain + bool m_protect{false}; + }; + + ChainSyncTimeoutState m_chain_sync; + + //! Time of last new block announcement + int64_t m_last_block_announcement{0}; + + //! Whether this peer is an inbound connection + const bool m_is_inbound; + + //! A rolling bloom filter of all announced tx CInvs to this peer. + CRollingBloomFilter m_recently_announced_invs = CRollingBloomFilter{INVENTORY_MAX_RECENT_RELAY, 0.000001}; + + CNodeState(bool is_inbound) : m_is_inbound(is_inbound) {} +}; + +class PeerManagerImpl final : public PeerManager +{ +public: + PeerManagerImpl(const CChainParams& chainparams, CConnman& connman, AddrMan& addrman, + BanMan* banman, ChainstateManager& chainman, + CTxMemPool& pool, bool ignore_incoming_txs); + + /** Overridden from CValidationInterface. */ + void BlockConnected(const std::shared_ptr<const CBlock>& pblock, const CBlockIndex* pindexConnected) override; + void BlockDisconnected(const std::shared_ptr<const CBlock> &block, const CBlockIndex* pindex) override; + void UpdatedBlockTip(const CBlockIndex *pindexNew, const CBlockIndex *pindexFork, bool fInitialDownload) override; + void BlockChecked(const CBlock& block, const BlockValidationState& state) override; + void NewPoWValidBlock(const CBlockIndex *pindex, const std::shared_ptr<const CBlock>& pblock) override; + + /** Implement NetEventsInterface */ + void InitializeNode(CNode* pnode) override; + void FinalizeNode(const CNode& node) override; + bool ProcessMessages(CNode* pfrom, std::atomic<bool>& interrupt) override; + bool SendMessages(CNode* pto) override EXCLUSIVE_LOCKS_REQUIRED(pto->cs_sendProcessing); + + /** Implement PeerManager */ + void StartScheduledTasks(CScheduler& scheduler) override; + void CheckForStaleTipAndEvictPeers() override; + std::optional<std::string> FetchBlock(NodeId peer_id, const CBlockIndex& block_index) override; + bool GetNodeStateStats(NodeId nodeid, CNodeStateStats& stats) const override; + bool IgnoresIncomingTxs() override { return m_ignore_incoming_txs; } + void SendPings() override; + void RelayTransaction(const uint256& txid, const uint256& wtxid) override; + void SetBestHeight(int height) override { m_best_height = height; }; + void Misbehaving(const NodeId pnode, const int howmuch, const std::string& message) override; + void ProcessMessage(CNode& pfrom, const std::string& msg_type, CDataStream& vRecv, + const std::chrono::microseconds time_received, const std::atomic<bool>& interruptMsgProc) override; + void UpdateLastBlockAnnounceTime(NodeId node, int64_t time_in_seconds) override; + +private: + /** Consider evicting an outbound peer based on the amount of time they've been behind our tip */ + void ConsiderEviction(CNode& pto, std::chrono::seconds time_in_seconds) EXCLUSIVE_LOCKS_REQUIRED(cs_main); + + /** If we have extra outbound peers, try to disconnect the one with the oldest block announcement */ + void EvictExtraOutboundPeers(std::chrono::seconds now) EXCLUSIVE_LOCKS_REQUIRED(cs_main); + + /** Retrieve unbroadcast transactions from the mempool and reattempt sending to peers */ + void ReattemptInitialBroadcast(CScheduler& scheduler); + + /** Get a shared pointer to the Peer object. + * May return an empty shared_ptr if the Peer object can't be found. */ + PeerRef GetPeerRef(NodeId id) const; + + /** Get a shared pointer to the Peer object and remove it from m_peer_map. + * May return an empty shared_ptr if the Peer object can't be found. */ + PeerRef RemovePeer(NodeId id); + + /** + * Potentially mark a node discouraged based on the contents of a BlockValidationState object + * + * @param[in] via_compact_block this bool is passed in because net_processing should + * punish peers differently depending on whether the data was provided in a compact + * block message or not. If the compact block had a valid header, but contained invalid + * txs, the peer should not be punished. See BIP 152. + * + * @return Returns true if the peer was punished (probably disconnected) + */ + bool MaybePunishNodeForBlock(NodeId nodeid, const BlockValidationState& state, + bool via_compact_block, const std::string& message = ""); + + /** + * Potentially disconnect and discourage a node based on the contents of a TxValidationState object + * + * @return Returns true if the peer was punished (probably disconnected) + */ + bool MaybePunishNodeForTx(NodeId nodeid, const TxValidationState& state, const std::string& message = ""); + + /** Maybe disconnect a peer and discourage future connections from its address. + * + * @param[in] pnode The node to check. + * @param[in] peer The peer object to check. + * @return True if the peer was marked for disconnection in this function + */ + bool MaybeDiscourageAndDisconnect(CNode& pnode, Peer& peer); + + void ProcessOrphanTx(std::set<uint256>& orphan_work_set) EXCLUSIVE_LOCKS_REQUIRED(cs_main, g_cs_orphans); + /** Process a single headers message from a peer. */ + void ProcessHeadersMessage(CNode& pfrom, const Peer& peer, + const std::vector<CBlockHeader>& headers, + bool via_compact_block); + + void SendBlockTransactions(CNode& pfrom, const CBlock& block, const BlockTransactionsRequest& req); + + /** Register with TxRequestTracker that an INV has been received from a + * peer. The announcement parameters are decided in PeerManager and then + * passed to TxRequestTracker. */ + void AddTxAnnouncement(const CNode& node, const GenTxid& gtxid, std::chrono::microseconds current_time) + EXCLUSIVE_LOCKS_REQUIRED(::cs_main); + + /** Send a version message to a peer */ + void PushNodeVersion(CNode& pnode, const Peer& peer); + + /** Send a ping message every PING_INTERVAL or if requested via RPC. May + * mark the peer to be disconnected if a ping has timed out. + * We use mockable time for ping timeouts, so setmocktime may cause pings + * to time out. */ + void MaybeSendPing(CNode& node_to, Peer& peer, std::chrono::microseconds now); + + /** Send `addr` messages on a regular schedule. */ + void MaybeSendAddr(CNode& node, Peer& peer, std::chrono::microseconds current_time); + + /** Relay (gossip) an address to a few randomly chosen nodes. + * + * @param[in] originator The id of the peer that sent us the address. We don't want to relay it back. + * @param[in] addr Address to relay. + * @param[in] fReachable Whether the address' network is reachable. We relay unreachable + * addresses less. + */ + void RelayAddress(NodeId originator, const CAddress& addr, bool fReachable); + + /** Send `feefilter` message. */ + void MaybeSendFeefilter(CNode& node, Peer& peer, std::chrono::microseconds current_time); + + const CChainParams& m_chainparams; + CConnman& m_connman; + AddrMan& m_addrman; + /** Pointer to this node's banman. May be nullptr - check existence before dereferencing. */ + BanMan* const m_banman; + ChainstateManager& m_chainman; + CTxMemPool& m_mempool; + TxRequestTracker m_txrequest GUARDED_BY(::cs_main); + + /** The height of the best chain */ + std::atomic<int> m_best_height{-1}; + + /** Next time to check for stale tip */ + std::chrono::seconds m_stale_tip_check_time{0s}; + + /** Whether this node is running in blocks only mode */ + const bool m_ignore_incoming_txs; + + /** Whether we've completed initial sync yet, for determining when to turn + * on extra block-relay-only peers. */ + bool m_initial_sync_finished{false}; + + /** Protects m_peer_map. This mutex must not be locked while holding a lock + * on any of the mutexes inside a Peer object. */ + mutable Mutex m_peer_mutex; + /** + * Map of all Peer objects, keyed by peer id. This map is protected + * by the m_peer_mutex. Once a shared pointer reference is + * taken, the lock may be released. Individual fields are protected by + * their own locks. + */ + std::map<NodeId, PeerRef> m_peer_map GUARDED_BY(m_peer_mutex); + + /** Map maintaining per-node state. */ + std::map<NodeId, CNodeState> m_node_states GUARDED_BY(cs_main); + + /** Get a pointer to a const CNodeState, used when not mutating the CNodeState object. */ + const CNodeState* State(NodeId pnode) const EXCLUSIVE_LOCKS_REQUIRED(cs_main); + /** Get a pointer to a mutable CNodeState. */ + CNodeState* State(NodeId pnode) EXCLUSIVE_LOCKS_REQUIRED(cs_main); + + uint32_t GetFetchFlags(const CNode& pfrom) const EXCLUSIVE_LOCKS_REQUIRED(cs_main); + + std::atomic<std::chrono::microseconds> m_next_inv_to_inbounds{0us}; + + /** Number of nodes with fSyncStarted. */ + int nSyncStarted GUARDED_BY(cs_main) = 0; + + /** + * Sources of received blocks, saved to be able punish them when processing + * happens afterwards. + * Set mapBlockSource[hash].second to false if the node should not be + * punished if the block is invalid. + */ + std::map<uint256, std::pair<NodeId, bool>> mapBlockSource GUARDED_BY(cs_main); + + /** Number of peers with wtxid relay. */ + std::atomic<int> m_wtxid_relay_peers{0}; + + /** Number of outbound peers with m_chain_sync.m_protect. */ + int m_outbound_peers_with_protect_from_disconnect GUARDED_BY(cs_main) = 0; + + /** Number of preferable block download peers. */ + int m_num_preferred_download_peers GUARDED_BY(cs_main){0}; + + bool AlreadyHaveTx(const GenTxid& gtxid) EXCLUSIVE_LOCKS_REQUIRED(cs_main); + + /** + * Filter for transactions that were recently rejected by the mempool. + * These are not rerequested until the chain tip changes, at which point + * the entire filter is reset. + * + * Without this filter we'd be re-requesting txs from each of our peers, + * increasing bandwidth consumption considerably. For instance, with 100 + * peers, half of which relay a tx we don't accept, that might be a 50x + * bandwidth increase. A flooding attacker attempting to roll-over the + * filter using minimum-sized, 60byte, transactions might manage to send + * 1000/sec if we have fast peers, so we pick 120,000 to give our peers a + * two minute window to send invs to us. + * + * Decreasing the false positive rate is fairly cheap, so we pick one in a + * million to make it highly unlikely for users to have issues with this + * filter. + * + * We typically only add wtxids to this filter. For non-segwit + * transactions, the txid == wtxid, so this only prevents us from + * re-downloading non-segwit transactions when communicating with + * non-wtxidrelay peers -- which is important for avoiding malleation + * attacks that could otherwise interfere with transaction relay from + * non-wtxidrelay peers. For communicating with wtxidrelay peers, having + * the reject filter store wtxids is exactly what we want to avoid + * redownload of a rejected transaction. + * + * In cases where we can tell that a segwit transaction will fail + * validation no matter the witness, we may add the txid of such + * transaction to the filter as well. This can be helpful when + * communicating with txid-relay peers or if we were to otherwise fetch a + * transaction via txid (eg in our orphan handling). + * + * Memory used: 1.3 MB + */ + CRollingBloomFilter m_recent_rejects GUARDED_BY(::cs_main){120'000, 0.000'001}; + uint256 hashRecentRejectsChainTip GUARDED_BY(cs_main); + + /* + * Filter for transactions that have been recently confirmed. + * We use this to avoid requesting transactions that have already been + * confirnmed. + * + * Blocks don't typically have more than 4000 transactions, so this should + * be at least six blocks (~1 hr) worth of transactions that we can store, + * inserting both a txid and wtxid for every observed transaction. + * If the number of transactions appearing in a block goes up, or if we are + * seeing getdata requests more than an hour after initial announcement, we + * can increase this number. + * The false positive rate of 1/1M should come out to less than 1 + * transaction per day that would be inadvertently ignored (which is the + * same probability that we have in the reject filter). + */ + Mutex m_recent_confirmed_transactions_mutex; + CRollingBloomFilter m_recent_confirmed_transactions GUARDED_BY(m_recent_confirmed_transactions_mutex){48'000, 0.000'001}; + + /** + * For sending `inv`s to inbound peers, we use a single (exponentially + * distributed) timer for all peers. If we used a separate timer for each + * peer, a spy node could make multiple inbound connections to us to + * accurately determine when we received the transaction (and potentially + * determine the transaction's origin). */ + std::chrono::microseconds NextInvToInbounds(std::chrono::microseconds now, + std::chrono::seconds average_interval); + + + // All of the following cache a recent block, and are protected by m_most_recent_block_mutex + RecursiveMutex m_most_recent_block_mutex; + std::shared_ptr<const CBlock> m_most_recent_block GUARDED_BY(m_most_recent_block_mutex); + std::shared_ptr<const CBlockHeaderAndShortTxIDs> m_most_recent_compact_block GUARDED_BY(m_most_recent_block_mutex); + uint256 m_most_recent_block_hash GUARDED_BY(m_most_recent_block_mutex); + bool m_most_recent_compact_block_has_witnesses GUARDED_BY(m_most_recent_block_mutex){false}; + + /** Height of the highest block announced using BIP 152 high-bandwidth mode. */ + int m_highest_fast_announce{0}; + + /** Have we requested this block from a peer */ + bool IsBlockRequested(const uint256& hash) EXCLUSIVE_LOCKS_REQUIRED(cs_main); + + /** Remove this block from our tracked requested blocks. Called if: + * - the block has been received from a peer + * - the request for the block has timed out + */ + void RemoveBlockRequest(const uint256& hash) EXCLUSIVE_LOCKS_REQUIRED(cs_main); + + /* Mark a block as in flight + * 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 BlockRequested(NodeId nodeid, const CBlockIndex& block, std::list<QueuedBlock>::iterator** pit = nullptr) EXCLUSIVE_LOCKS_REQUIRED(cs_main); + + bool TipMayBeStale() EXCLUSIVE_LOCKS_REQUIRED(cs_main); + + /** Update pindexLastCommonBlock and add not-in-flight missing successors to vBlocks, until it has + * at most count entries. + */ + void FindNextBlocksToDownload(NodeId nodeid, unsigned int count, std::vector<const CBlockIndex*>& vBlocks, NodeId& nodeStaller) EXCLUSIVE_LOCKS_REQUIRED(cs_main); + + std::map<uint256, std::pair<NodeId, std::list<QueuedBlock>::iterator> > mapBlocksInFlight GUARDED_BY(cs_main); + + /** When our tip was last updated. */ + std::atomic<std::chrono::seconds> m_last_tip_update{0s}; + + /** Determine whether or not a peer can request a transaction, and return it (or nullptr if not found or not allowed). */ + CTransactionRef FindTxForGetData(const CNode& peer, const GenTxid& gtxid, const std::chrono::seconds mempool_req, const std::chrono::seconds now) LOCKS_EXCLUDED(cs_main); + + void ProcessGetData(CNode& pfrom, Peer& peer, const std::atomic<bool>& interruptMsgProc) EXCLUSIVE_LOCKS_REQUIRED(peer.m_getdata_requests_mutex) LOCKS_EXCLUDED(::cs_main); + + /** Process a new block. Perform any post-processing housekeeping */ + void ProcessBlock(CNode& node, const std::shared_ptr<const CBlock>& block, bool force_processing); + + /** Relay map (txid or wtxid -> CTransactionRef) */ + typedef std::map<uint256, CTransactionRef> MapRelay; + MapRelay mapRelay GUARDED_BY(cs_main); + /** Expiration-time ordered list of (expire time, relay map entry) pairs. */ + std::deque<std::pair<std::chrono::microseconds, MapRelay::iterator>> g_relay_expiration GUARDED_BY(cs_main); + + /** + * When a peer sends us a valid block, instruct it to announce blocks to us + * using CMPCTBLOCK if possible by adding its nodeid to the end of + * lNodesAnnouncingHeaderAndIDs, and keeping that list under a certain size by + * removing the first element if necessary. + */ + void MaybeSetPeerAsAnnouncingHeaderAndIDs(NodeId nodeid) EXCLUSIVE_LOCKS_REQUIRED(cs_main); + + /** Stack of nodes which we have set to announce using compact blocks */ + std::list<NodeId> lNodesAnnouncingHeaderAndIDs GUARDED_BY(cs_main); + + /** Number of peers from which we're downloading blocks. */ + int m_peers_downloading_from GUARDED_BY(cs_main) = 0; + + /** Storage for orphan information */ + TxOrphanage m_orphanage; + + void AddToCompactExtraTransactions(const CTransactionRef& tx) EXCLUSIVE_LOCKS_REQUIRED(g_cs_orphans); + + /** Orphan/conflicted/etc transactions that are kept for compact block reconstruction. + * The last -blockreconstructionextratxn/DEFAULT_BLOCK_RECONSTRUCTION_EXTRA_TXN of + * these are kept in a ring buffer */ + std::vector<std::pair<uint256, CTransactionRef>> vExtraTxnForCompact GUARDED_BY(g_cs_orphans); + /** Offset into vExtraTxnForCompact to insert the next tx */ + size_t vExtraTxnForCompactIt GUARDED_BY(g_cs_orphans) = 0; + + /** Check whether the last unknown block a peer advertised is not yet known. */ + void ProcessBlockAvailability(NodeId nodeid) EXCLUSIVE_LOCKS_REQUIRED(cs_main); + /** Update tracking information about which blocks a peer is assumed to have. */ + void UpdateBlockAvailability(NodeId nodeid, const uint256& hash) EXCLUSIVE_LOCKS_REQUIRED(cs_main); + bool CanDirectFetch() EXCLUSIVE_LOCKS_REQUIRED(cs_main); + + /** + * 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. + */ + bool BlockRequestAllowed(const CBlockIndex* pindex) EXCLUSIVE_LOCKS_REQUIRED(cs_main); + bool AlreadyHaveBlock(const uint256& block_hash) EXCLUSIVE_LOCKS_REQUIRED(cs_main); + void ProcessGetBlockData(CNode& pfrom, Peer& peer, const CInv& inv); + + /** + * Validation logic for compact filters request handling. + * + * May disconnect from the peer in the case of a bad request. + * + * @param[in] peer The peer that we received the request from + * @param[in] filter_type The filter type the request is for. Must be basic filters. + * @param[in] start_height The start height for the request + * @param[in] stop_hash The stop_hash for the request + * @param[in] max_height_diff The maximum number of items permitted to request, as specified in BIP 157 + * @param[out] stop_index The CBlockIndex for the stop_hash block, if the request can be serviced. + * @param[out] filter_index The filter index, if the request can be serviced. + * @return True if the request can be serviced. + */ + bool PrepareBlockFilterRequest(CNode& peer, + BlockFilterType filter_type, uint32_t start_height, + const uint256& stop_hash, uint32_t max_height_diff, + const CBlockIndex*& stop_index, + BlockFilterIndex*& filter_index); + + /** + * Handle a cfilters request. + * + * May disconnect from the peer in the case of a bad request. + * + * @param[in] peer The peer that we received the request from + * @param[in] vRecv The raw message received + */ + void ProcessGetCFilters(CNode& peer, CDataStream& vRecv); + + /** + * Handle a cfheaders request. + * + * May disconnect from the peer in the case of a bad request. + * + * @param[in] peer The peer that we received the request from + * @param[in] vRecv The raw message received + */ + void ProcessGetCFHeaders(CNode& peer, CDataStream& vRecv); + + /** + * Handle a getcfcheckpt request. + * + * May disconnect from the peer in the case of a bad request. + * + * @param[in] peer The peer that we received the request from + * @param[in] vRecv The raw message received + */ + void ProcessGetCFCheckPt(CNode& peer, CDataStream& vRecv); + + /** Checks if address relay is permitted with peer. If needed, initializes + * the m_addr_known bloom filter and sets m_addr_relay_enabled to true. + * + * @return True if address relay is enabled with peer + * False if address relay is disallowed + */ + bool SetupAddressRelay(const CNode& node, Peer& peer); +}; + +const CNodeState* PeerManagerImpl::State(NodeId pnode) const EXCLUSIVE_LOCKS_REQUIRED(cs_main) +{ + std::map<NodeId, CNodeState>::const_iterator it = m_node_states.find(pnode); + if (it == m_node_states.end()) + return nullptr; + return &it->second; +} + +CNodeState* PeerManagerImpl::State(NodeId pnode) EXCLUSIVE_LOCKS_REQUIRED(cs_main) +{ + return const_cast<CNodeState*>(std::as_const(*this).State(pnode)); +} + +/** + * Whether the peer supports the address. For example, a peer that does not + * implement BIP155 cannot receive Tor v3 addresses because it requires + * ADDRv2 (BIP155) encoding. + */ +static bool IsAddrCompatible(const Peer& peer, const CAddress& addr) +{ + return peer.m_wants_addrv2 || addr.IsAddrV1Compatible(); +} + +static void AddAddressKnown(Peer& peer, const CAddress& addr) +{ + assert(peer.m_addr_known); + peer.m_addr_known->insert(addr.GetKey()); +} + +static void PushAddress(Peer& peer, const CAddress& addr, FastRandomContext& insecure_rand) +{ + // Known checking here is only to save space from duplicates. + // Before sending, we'll filter it again for known addresses that were + // added after addresses were pushed. + assert(peer.m_addr_known); + if (addr.IsValid() && !peer.m_addr_known->contains(addr.GetKey()) && IsAddrCompatible(peer, addr)) { + if (peer.m_addrs_to_send.size() >= MAX_ADDR_TO_SEND) { + peer.m_addrs_to_send[insecure_rand.randrange(peer.m_addrs_to_send.size())] = addr; + } else { + peer.m_addrs_to_send.push_back(addr); + } + } +} + +static void AddKnownTx(Peer& peer, const uint256& hash) +{ + if (peer.m_tx_relay != nullptr) { + LOCK(peer.m_tx_relay->m_tx_inventory_mutex); + peer.m_tx_relay->m_tx_inventory_known_filter.insert(hash); + } +} + +std::chrono::microseconds PeerManagerImpl::NextInvToInbounds(std::chrono::microseconds now, + std::chrono::seconds average_interval) +{ + if (m_next_inv_to_inbounds.load() < now) { + // If this function were called from multiple threads simultaneously + // it would possible that both update the next send variable, and return a different result to their caller. + // This is not possible in practice as only the net processing thread invokes this function. + m_next_inv_to_inbounds = GetExponentialRand(now, average_interval); + } + return m_next_inv_to_inbounds; +} + +bool PeerManagerImpl::IsBlockRequested(const uint256& hash) +{ + return mapBlocksInFlight.find(hash) != mapBlocksInFlight.end(); +} + +void PeerManagerImpl::RemoveBlockRequest(const uint256& hash) +{ + auto it = mapBlocksInFlight.find(hash); + if (it == mapBlocksInFlight.end()) { + // Block was not requested + return; + } + + auto [node_id, list_it] = it->second; + CNodeState *state = State(node_id); + assert(state != nullptr); + + if (state->vBlocksInFlight.begin() == list_it) { + // First block on the queue was received, update the start download time for the next one + state->m_downloading_since = std::max(state->m_downloading_since, GetTime<std::chrono::microseconds>()); + } + state->vBlocksInFlight.erase(list_it); + + state->nBlocksInFlight--; + if (state->nBlocksInFlight == 0) { + // Last validated block on the queue was received. + m_peers_downloading_from--; + } + state->m_stalling_since = 0us; + mapBlocksInFlight.erase(it); +} + +bool PeerManagerImpl::BlockRequested(NodeId nodeid, const CBlockIndex& block, std::list<QueuedBlock>::iterator** pit) +{ + const uint256& hash{block.GetBlockHash()}; + + CNodeState *state = State(nodeid); + assert(state != nullptr); + + // Short-circuit most stuff in case it is from the same node + std::map<uint256, std::pair<NodeId, std::list<QueuedBlock>::iterator> >::iterator itInFlight = mapBlocksInFlight.find(hash); + if (itInFlight != mapBlocksInFlight.end() && itInFlight->second.first == nodeid) { + if (pit) { + *pit = &itInFlight->second.second; + } + return false; + } + + // Make sure it's not listed somewhere already. + RemoveBlockRequest(hash); + + std::list<QueuedBlock>::iterator it = state->vBlocksInFlight.insert(state->vBlocksInFlight.end(), + {&block, std::unique_ptr<PartiallyDownloadedBlock>(pit ? new PartiallyDownloadedBlock(&m_mempool) : nullptr)}); + state->nBlocksInFlight++; + if (state->nBlocksInFlight == 1) { + // We're starting a block download (batch) from this peer. + state->m_downloading_since = GetTime<std::chrono::microseconds>(); + m_peers_downloading_from++; + } + itInFlight = mapBlocksInFlight.insert(std::make_pair(hash, std::make_pair(nodeid, it))).first; + if (pit) { + *pit = &itInFlight->second.second; + } + return true; +} + +void PeerManagerImpl::MaybeSetPeerAsAnnouncingHeaderAndIDs(NodeId nodeid) +{ + AssertLockHeld(cs_main); + + // Never request high-bandwidth mode from peers if we're blocks-only. Our + // mempool will not contain the transactions necessary to reconstruct the + // compact block. + if (m_ignore_incoming_txs) return; + + CNodeState* nodestate = State(nodeid); + if (!nodestate || !nodestate->fSupportsDesiredCmpctVersion) { + // Never ask from peers who can't provide witnesses. + return; + } + if (nodestate->fProvidesHeaderAndIDs) { + int num_outbound_hb_peers = 0; + for (std::list<NodeId>::iterator it = lNodesAnnouncingHeaderAndIDs.begin(); it != lNodesAnnouncingHeaderAndIDs.end(); it++) { + if (*it == nodeid) { + lNodesAnnouncingHeaderAndIDs.erase(it); + lNodesAnnouncingHeaderAndIDs.push_back(nodeid); + return; + } + CNodeState *state = State(*it); + if (state != nullptr && !state->m_is_inbound) ++num_outbound_hb_peers; + } + if (nodestate->m_is_inbound) { + // If we're adding an inbound HB peer, make sure we're not removing + // our last outbound HB peer in the process. + if (lNodesAnnouncingHeaderAndIDs.size() >= 3 && num_outbound_hb_peers == 1) { + CNodeState *remove_node = State(lNodesAnnouncingHeaderAndIDs.front()); + if (remove_node != nullptr && !remove_node->m_is_inbound) { + // Put the HB outbound peer in the second slot, so that it + // doesn't get removed. + std::swap(lNodesAnnouncingHeaderAndIDs.front(), *std::next(lNodesAnnouncingHeaderAndIDs.begin())); + } + } + } + m_connman.ForNode(nodeid, [this](CNode* pfrom) EXCLUSIVE_LOCKS_REQUIRED(::cs_main) { + AssertLockHeld(::cs_main); + uint64_t nCMPCTBLOCKVersion = 2; + if (lNodesAnnouncingHeaderAndIDs.size() >= 3) { + // As per BIP152, we only get 3 of our peers to announce + // blocks using compact encodings. + m_connman.ForNode(lNodesAnnouncingHeaderAndIDs.front(), [this, nCMPCTBLOCKVersion](CNode* pnodeStop){ + m_connman.PushMessage(pnodeStop, CNetMsgMaker(pnodeStop->GetCommonVersion()).Make(NetMsgType::SENDCMPCT, /*fAnnounceUsingCMPCTBLOCK=*/false, nCMPCTBLOCKVersion)); + // save BIP152 bandwidth state: we select peer to be low-bandwidth + pnodeStop->m_bip152_highbandwidth_to = false; + return true; + }); + lNodesAnnouncingHeaderAndIDs.pop_front(); + } + m_connman.PushMessage(pfrom, CNetMsgMaker(pfrom->GetCommonVersion()).Make(NetMsgType::SENDCMPCT, /*fAnnounceUsingCMPCTBLOCK=*/true, nCMPCTBLOCKVersion)); + // save BIP152 bandwidth state: we select peer to be high-bandwidth + pfrom->m_bip152_highbandwidth_to = true; + lNodesAnnouncingHeaderAndIDs.push_back(pfrom->GetId()); + return true; + }); + } +} + +bool PeerManagerImpl::TipMayBeStale() +{ + AssertLockHeld(cs_main); + const Consensus::Params& consensusParams = m_chainparams.GetConsensus(); + if (m_last_tip_update.load() == 0s) { + m_last_tip_update = GetTime<std::chrono::seconds>(); + } + return m_last_tip_update.load() < GetTime<std::chrono::seconds>() - std::chrono::seconds{consensusParams.nPowTargetSpacing * 3} && mapBlocksInFlight.empty(); +} + +bool PeerManagerImpl::CanDirectFetch() +{ + return m_chainman.ActiveChain().Tip()->GetBlockTime() > GetAdjustedTime() - m_chainparams.GetConsensus().nPowTargetSpacing * 20; +} + +static bool PeerHasHeader(CNodeState *state, const CBlockIndex *pindex) EXCLUSIVE_LOCKS_REQUIRED(cs_main) +{ + if (state->pindexBestKnownBlock && pindex == state->pindexBestKnownBlock->GetAncestor(pindex->nHeight)) + return true; + if (state->pindexBestHeaderSent && pindex == state->pindexBestHeaderSent->GetAncestor(pindex->nHeight)) + return true; + return false; +} + +void PeerManagerImpl::ProcessBlockAvailability(NodeId nodeid) { + CNodeState *state = State(nodeid); + assert(state != nullptr); + + if (!state->hashLastUnknownBlock.IsNull()) { + const CBlockIndex* pindex = m_chainman.m_blockman.LookupBlockIndex(state->hashLastUnknownBlock); + if (pindex && pindex->nChainWork > 0) { + if (state->pindexBestKnownBlock == nullptr || pindex->nChainWork >= state->pindexBestKnownBlock->nChainWork) { + state->pindexBestKnownBlock = pindex; + } + state->hashLastUnknownBlock.SetNull(); + } + } +} + +void PeerManagerImpl::UpdateBlockAvailability(NodeId nodeid, const uint256 &hash) { + CNodeState *state = State(nodeid); + assert(state != nullptr); + + ProcessBlockAvailability(nodeid); + + const CBlockIndex* pindex = m_chainman.m_blockman.LookupBlockIndex(hash); + if (pindex && pindex->nChainWork > 0) { + // An actually better block was announced. + if (state->pindexBestKnownBlock == nullptr || pindex->nChainWork >= state->pindexBestKnownBlock->nChainWork) { + state->pindexBestKnownBlock = pindex; + } + } else { + // An unknown block was announced; just assume that the latest one is the best one. + state->hashLastUnknownBlock = hash; + } +} + +void PeerManagerImpl::FindNextBlocksToDownload(NodeId nodeid, unsigned int count, std::vector<const CBlockIndex*>& vBlocks, NodeId& nodeStaller) +{ + if (count == 0) + return; + + vBlocks.reserve(vBlocks.size() + count); + CNodeState *state = State(nodeid); + assert(state != nullptr); + + // Make sure pindexBestKnownBlock is up to date, we'll need it. + ProcessBlockAvailability(nodeid); + + if (state->pindexBestKnownBlock == nullptr || state->pindexBestKnownBlock->nChainWork < m_chainman.ActiveChain().Tip()->nChainWork || state->pindexBestKnownBlock->nChainWork < nMinimumChainWork) { + // This peer has nothing interesting. + return; + } + + 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 = m_chainman.ActiveChain()[std::min(state->pindexBestKnownBlock->nHeight, m_chainman.ActiveChain().Height())]; + } + + // If the peer reorganized, our previous pindexLastCommonBlock may not be an ancestor + // of its current tip anymore. Go back enough to fix that. + state->pindexLastCommonBlock = LastCommonAncestor(state->pindexLastCommonBlock, state->pindexBestKnownBlock); + if (state->pindexLastCommonBlock == state->pindexBestKnownBlock) + return; + + const Consensus::Params& consensusParams = m_chainparams.GetConsensus(); + std::vector<const CBlockIndex*> vToFetch; + const CBlockIndex *pindexWalk = state->pindexLastCommonBlock; + // Never fetch further than the best block we know the peer has, or more than BLOCK_DOWNLOAD_WINDOW + 1 beyond the last + // linked block we have in common with this peer. The +1 is so we can detect stalling, namely if we would be able to + // download that next block if the window were 1 larger. + int nWindowEnd = state->pindexLastCommonBlock->nHeight + BLOCK_DOWNLOAD_WINDOW; + int nMaxHeight = std::min<int>(state->pindexBestKnownBlock->nHeight, nWindowEnd + 1); + NodeId waitingfor = -1; + while (pindexWalk->nHeight < nMaxHeight) { + // Read up to 128 (or more, if more blocks than that are needed) successors of pindexWalk (towards + // pindexBestKnownBlock) into vToFetch. We fetch 128, because CBlockIndex::GetAncestor may be as expensive + // as iterating over ~100 CBlockIndex* entries anyway. + int nToFetch = std::min(nMaxHeight - pindexWalk->nHeight, std::max<int>(count - vBlocks.size(), 128)); + vToFetch.resize(nToFetch); + pindexWalk = state->pindexBestKnownBlock->GetAncestor(pindexWalk->nHeight + nToFetch); + vToFetch[nToFetch - 1] = pindexWalk; + for (unsigned int i = nToFetch - 1; i > 0; i--) { + vToFetch[i - 1] = vToFetch[i]->pprev; + } + + // Iterate over those blocks in vToFetch (in forward direction), adding the ones that + // are not yet downloaded and not in flight to vBlocks. In the meantime, update + // pindexLastCommonBlock as long as all ancestors are already downloaded, or if it's + // already part of our chain (and therefore don't need it even if pruned). + for (const CBlockIndex* pindex : vToFetch) { + if (!pindex->IsValid(BLOCK_VALID_TREE)) { + // We consider the chain that this peer is on invalid. + return; + } + if (!State(nodeid)->fHaveWitness && DeploymentActiveAt(*pindex, consensusParams, Consensus::DEPLOYMENT_SEGWIT)) { + // We wouldn't download this block or its descendants from this peer. + return; + } + if (pindex->nStatus & BLOCK_HAVE_DATA || m_chainman.ActiveChain().Contains(pindex)) { + if (pindex->HaveTxsDownloaded()) + state->pindexLastCommonBlock = pindex; + } else if (!IsBlockRequested(pindex->GetBlockHash())) { + // The block is not already downloaded, and not yet in flight. + if (pindex->nHeight > nWindowEnd) { + // We reached the end of the window. + if (vBlocks.size() == 0 && waitingfor != nodeid) { + // We aren't able to fetch anything, but we would be if the download window was one larger. + nodeStaller = waitingfor; + } + return; + } + vBlocks.push_back(pindex); + if (vBlocks.size() == count) { + return; + } + } else if (waitingfor == -1) { + // This is the first already-in-flight block. + waitingfor = mapBlocksInFlight[pindex->GetBlockHash()].first; + } + } + } +} + +} // namespace + +void PeerManagerImpl::PushNodeVersion(CNode& pnode, const Peer& peer) +{ + // Note that pnode->GetLocalServices() is a reflection of the local + // services we were offering when the CNode object was created for this + // peer. + uint64_t my_services{pnode.GetLocalServices()}; + const int64_t nTime{count_seconds(GetTime<std::chrono::seconds>())}; + uint64_t nonce = pnode.GetLocalNonce(); + const int nNodeStartingHeight{m_best_height}; + NodeId nodeid = pnode.GetId(); + CAddress addr = pnode.addr; + + CService addr_you = addr.IsRoutable() && !IsProxy(addr) && addr.IsAddrV1Compatible() ? addr : CService(); + uint64_t your_services{addr.nServices}; + + const bool tx_relay = !m_ignore_incoming_txs && peer.m_tx_relay != nullptr && !pnode.IsFeelerConn(); + m_connman.PushMessage(&pnode, CNetMsgMaker(INIT_PROTO_VERSION).Make(NetMsgType::VERSION, PROTOCOL_VERSION, my_services, nTime, + your_services, addr_you, // Together the pre-version-31402 serialization of CAddress "addrYou" (without nTime) + my_services, CService(), // Together the pre-version-31402 serialization of CAddress "addrMe" (without nTime) + nonce, strSubVersion, nNodeStartingHeight, tx_relay)); + + if (fLogIPs) { + LogPrint(BCLog::NET, "send version message: version %d, blocks=%d, them=%s, txrelay=%d, peer=%d\n", PROTOCOL_VERSION, nNodeStartingHeight, addr_you.ToString(), tx_relay, nodeid); + } else { + LogPrint(BCLog::NET, "send version message: version %d, blocks=%d, txrelay=%d, peer=%d\n", PROTOCOL_VERSION, nNodeStartingHeight, tx_relay, nodeid); + } +} + +void PeerManagerImpl::AddTxAnnouncement(const CNode& node, const GenTxid& gtxid, std::chrono::microseconds current_time) +{ + AssertLockHeld(::cs_main); // For m_txrequest + NodeId nodeid = node.GetId(); + if (!node.HasPermission(NetPermissionFlags::Relay) && m_txrequest.Count(nodeid) >= MAX_PEER_TX_ANNOUNCEMENTS) { + // Too many queued announcements from this peer + return; + } + const CNodeState* state = State(nodeid); + + // Decide the TxRequestTracker parameters for this announcement: + // - "preferred": if fPreferredDownload is set (= outbound, or NetPermissionFlags::NoBan permission) + // - "reqtime": current time plus delays for: + // - NONPREF_PEER_TX_DELAY for announcements from non-preferred connections + // - TXID_RELAY_DELAY for txid announcements 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 (and don't have NetPermissionFlags::Relay). + auto delay{0us}; + const bool preferred = state->fPreferredDownload; + if (!preferred) delay += NONPREF_PEER_TX_DELAY; + if (!gtxid.IsWtxid() && m_wtxid_relay_peers > 0) delay += TXID_RELAY_DELAY; + const bool overloaded = !node.HasPermission(NetPermissionFlags::Relay) && + 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); +} + +void PeerManagerImpl::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; +} + +void PeerManagerImpl::InitializeNode(CNode *pnode) +{ + NodeId nodeid = pnode->GetId(); + { + LOCK(cs_main); + m_node_states.emplace_hint(m_node_states.end(), std::piecewise_construct, std::forward_as_tuple(nodeid), std::forward_as_tuple(pnode->IsInboundConn())); + assert(m_txrequest.Count(nodeid) == 0); + } + PeerRef peer = std::make_shared<Peer>(nodeid, /*tx_relay=*/ !pnode->IsBlockOnlyConn()); + { + LOCK(m_peer_mutex); + m_peer_map.emplace_hint(m_peer_map.end(), nodeid, peer); + } + if (!pnode->IsInboundConn()) { + PushNodeVersion(*pnode, *peer); + } +} + +void PeerManagerImpl::ReattemptInitialBroadcast(CScheduler& scheduler) +{ + std::set<uint256> unbroadcast_txids = m_mempool.GetUnbroadcastTxs(); + + for (const auto& txid : unbroadcast_txids) { + CTransactionRef tx = m_mempool.get(txid); + + if (tx != nullptr) { + RelayTransaction(txid, tx->GetWitnessHash()); + } else { + m_mempool.RemoveUnbroadcastTx(txid, true); + } + } + + // Schedule next run for 10-15 minutes in the future. + // We add randomness on every cycle to avoid the possibility of P2P fingerprinting. + const std::chrono::milliseconds delta = 10min + GetRandMillis(5min); + scheduler.scheduleFromNow([&] { ReattemptInitialBroadcast(scheduler); }, delta); +} + +void PeerManagerImpl::FinalizeNode(const CNode& node) +{ + NodeId nodeid = node.GetId(); + int misbehavior{0}; + { + LOCK(cs_main); + { + // We remove the PeerRef from g_peer_map here, but we don't always + // destruct the Peer. Sometimes another thread is still holding a + // PeerRef, so the refcount is >= 1. Be careful not to do any + // processing here that assumes Peer won't be changed before it's + // destructed. + PeerRef peer = RemovePeer(nodeid); + assert(peer != nullptr); + misbehavior = WITH_LOCK(peer->m_misbehavior_mutex, return peer->m_misbehavior_score); + m_wtxid_relay_peers -= peer->m_wtxid_relay; + assert(m_wtxid_relay_peers >= 0); + } + CNodeState *state = State(nodeid); + assert(state != nullptr); + + if (state->fSyncStarted) + nSyncStarted--; + + for (const QueuedBlock& entry : state->vBlocksInFlight) { + mapBlocksInFlight.erase(entry.pindex->GetBlockHash()); + } + WITH_LOCK(g_cs_orphans, m_orphanage.EraseForPeer(nodeid)); + m_txrequest.DisconnectedPeer(nodeid); + m_num_preferred_download_peers -= state->fPreferredDownload; + m_peers_downloading_from -= (state->nBlocksInFlight != 0); + assert(m_peers_downloading_from >= 0); + m_outbound_peers_with_protect_from_disconnect -= state->m_chain_sync.m_protect; + assert(m_outbound_peers_with_protect_from_disconnect >= 0); + + m_node_states.erase(nodeid); + + if (m_node_states.empty()) { + // Do a consistency check after the last peer is removed. + assert(mapBlocksInFlight.empty()); + assert(m_num_preferred_download_peers == 0); + assert(m_peers_downloading_from == 0); + assert(m_outbound_peers_with_protect_from_disconnect == 0); + assert(m_wtxid_relay_peers == 0); + assert(m_txrequest.Size() == 0); + assert(m_orphanage.Size() == 0); + } + } // cs_main + if (node.fSuccessfullyConnected && misbehavior == 0 && + !node.IsBlockOnlyConn() && !node.IsInboundConn()) { + // Only change visible addrman state for full outbound peers. We don't + // call Connected() for feeler connections since they don't have + // fSuccessfullyConnected set. + m_addrman.Connected(node.addr); + } + LogPrint(BCLog::NET, "Cleared nodestate for peer=%d\n", nodeid); +} + +PeerRef PeerManagerImpl::GetPeerRef(NodeId id) const +{ + LOCK(m_peer_mutex); + auto it = m_peer_map.find(id); + return it != m_peer_map.end() ? it->second : nullptr; +} + +PeerRef PeerManagerImpl::RemovePeer(NodeId id) +{ + PeerRef ret; + LOCK(m_peer_mutex); + auto it = m_peer_map.find(id); + if (it != m_peer_map.end()) { + ret = std::move(it->second); + m_peer_map.erase(it); + } + return ret; +} + +bool PeerManagerImpl::GetNodeStateStats(NodeId nodeid, CNodeStateStats& stats) const +{ + { + LOCK(cs_main); + const CNodeState* state = State(nodeid); + if (state == nullptr) + return false; + stats.nSyncHeight = state->pindexBestKnownBlock ? state->pindexBestKnownBlock->nHeight : -1; + stats.nCommonHeight = state->pindexLastCommonBlock ? state->pindexLastCommonBlock->nHeight : -1; + for (const QueuedBlock& queue : state->vBlocksInFlight) { + if (queue.pindex) + stats.vHeightInFlight.push_back(queue.pindex->nHeight); + } + } + + PeerRef peer = GetPeerRef(nodeid); + if (peer == nullptr) return false; + stats.m_starting_height = peer->m_starting_height; + // It is common for nodes with good ping times to suddenly become lagged, + // due to a new block arriving or other large transfer. + // Merely reporting pingtime might fool the caller into thinking the node was still responsive, + // since pingtime does not update until the ping is complete, which might take a while. + // So, if a ping is taking an unusually long time in flight, + // the caller can immediately detect that this is happening. + auto ping_wait{0us}; + if ((0 != peer->m_ping_nonce_sent) && (0 != peer->m_ping_start.load().count())) { + ping_wait = GetTime<std::chrono::microseconds>() - peer->m_ping_start.load(); + } + + if (peer->m_tx_relay != nullptr) { + stats.m_relay_txs = WITH_LOCK(peer->m_tx_relay->m_bloom_filter_mutex, return peer->m_tx_relay->m_relay_txs); + stats.m_fee_filter_received = peer->m_tx_relay->m_fee_filter_received.load(); + } else { + stats.m_relay_txs = false; + stats.m_fee_filter_received = 0; + } + + stats.m_ping_wait = ping_wait; + stats.m_addr_processed = peer->m_addr_processed.load(); + stats.m_addr_rate_limited = peer->m_addr_rate_limited.load(); + stats.m_addr_relay_enabled = peer->m_addr_relay_enabled.load(); + + return true; +} + +void PeerManagerImpl::AddToCompactExtraTransactions(const CTransactionRef& tx) +{ + size_t max_extra_txn = gArgs.GetIntArg("-blockreconstructionextratxn", DEFAULT_BLOCK_RECONSTRUCTION_EXTRA_TXN); + if (max_extra_txn <= 0) + return; + if (!vExtraTxnForCompact.size()) + vExtraTxnForCompact.resize(max_extra_txn); + vExtraTxnForCompact[vExtraTxnForCompactIt] = std::make_pair(tx->GetWitnessHash(), tx); + vExtraTxnForCompactIt = (vExtraTxnForCompactIt + 1) % max_extra_txn; +} + +void PeerManagerImpl::Misbehaving(const NodeId pnode, const int howmuch, const std::string& message) +{ + assert(howmuch > 0); + + PeerRef peer = GetPeerRef(pnode); + if (peer == nullptr) return; + + LOCK(peer->m_misbehavior_mutex); + const int score_before{peer->m_misbehavior_score}; + peer->m_misbehavior_score += howmuch; + const int score_now{peer->m_misbehavior_score}; + + const std::string message_prefixed = message.empty() ? "" : (": " + message); + std::string warning; + + if (score_now >= DISCOURAGEMENT_THRESHOLD && score_before < DISCOURAGEMENT_THRESHOLD) { + warning = " DISCOURAGE THRESHOLD EXCEEDED"; + peer->m_should_discourage = true; + } + + LogPrint(BCLog::NET, "Misbehaving: peer=%d (%d -> %d)%s%s\n", + pnode, score_before, score_now, warning, message_prefixed); +} + +bool PeerManagerImpl::MaybePunishNodeForBlock(NodeId nodeid, const BlockValidationState& state, + bool via_compact_block, const std::string& message) +{ + switch (state.GetResult()) { + case BlockValidationResult::BLOCK_RESULT_UNSET: + break; + // The node is providing invalid data: + case BlockValidationResult::BLOCK_CONSENSUS: + case BlockValidationResult::BLOCK_MUTATED: + if (!via_compact_block) { + Misbehaving(nodeid, 100, message); + return true; + } + break; + case BlockValidationResult::BLOCK_CACHED_INVALID: + { + LOCK(cs_main); + CNodeState *node_state = State(nodeid); + if (node_state == nullptr) { + break; + } + + // Discourage outbound (but not inbound) peers if on an invalid chain. + // Exempt HB compact block peers. Manual connections are always protected from discouragement. + if (!via_compact_block && !node_state->m_is_inbound) { + Misbehaving(nodeid, 100, message); + return true; + } + break; + } + case BlockValidationResult::BLOCK_INVALID_HEADER: + case BlockValidationResult::BLOCK_CHECKPOINT: + case BlockValidationResult::BLOCK_INVALID_PREV: + Misbehaving(nodeid, 100, message); + return true; + // Conflicting (but not necessarily invalid) data or different policy: + case BlockValidationResult::BLOCK_MISSING_PREV: + // TODO: Handle this much more gracefully (10 DoS points is super arbitrary) + Misbehaving(nodeid, 10, message); + return true; + case BlockValidationResult::BLOCK_RECENT_CONSENSUS_CHANGE: + case BlockValidationResult::BLOCK_TIME_FUTURE: + break; + } + if (message != "") { + LogPrint(BCLog::NET, "peer=%d: %s\n", nodeid, message); + } + return false; +} + +bool PeerManagerImpl::MaybePunishNodeForTx(NodeId nodeid, const TxValidationState& state, const std::string& message) +{ + switch (state.GetResult()) { + case TxValidationResult::TX_RESULT_UNSET: + break; + // The node is providing invalid data: + case TxValidationResult::TX_CONSENSUS: + Misbehaving(nodeid, 100, message); + return true; + // Conflicting (but not necessarily invalid) data or different policy: + case TxValidationResult::TX_RECENT_CONSENSUS_CHANGE: + case TxValidationResult::TX_INPUTS_NOT_STANDARD: + case TxValidationResult::TX_NOT_STANDARD: + case TxValidationResult::TX_MISSING_INPUTS: + case TxValidationResult::TX_PREMATURE_SPEND: + case TxValidationResult::TX_WITNESS_MUTATED: + case TxValidationResult::TX_WITNESS_STRIPPED: + case TxValidationResult::TX_CONFLICT: + case TxValidationResult::TX_MEMPOOL_POLICY: + case TxValidationResult::TX_NO_MEMPOOL: + break; + } + if (message != "") { + LogPrint(BCLog::NET, "peer=%d: %s\n", nodeid, message); + } + return false; +} + +bool PeerManagerImpl::BlockRequestAllowed(const CBlockIndex* pindex) +{ + AssertLockHeld(cs_main); + if (m_chainman.ActiveChain().Contains(pindex)) return true; + return pindex->IsValid(BLOCK_VALID_SCRIPTS) && (m_chainman.m_best_header != nullptr) && + (m_chainman.m_best_header->GetBlockTime() - pindex->GetBlockTime() < STALE_RELAY_AGE_LIMIT) && + (GetBlockProofEquivalentTime(*m_chainman.m_best_header, *pindex, *m_chainman.m_best_header, m_chainparams.GetConsensus()) < STALE_RELAY_AGE_LIMIT); +} + +std::optional<std::string> PeerManagerImpl::FetchBlock(NodeId peer_id, const CBlockIndex& block_index) +{ + if (fImporting) return "Importing..."; + if (fReindex) return "Reindexing..."; + + LOCK(cs_main); + // Ensure this peer exists and hasn't been disconnected + CNodeState* state = State(peer_id); + if (state == nullptr) return "Peer does not exist"; + // Ignore pre-segwit peers + if (!state->fHaveWitness) return "Pre-SegWit peer"; + + // Mark block as in-flight unless it already is (for this peer). + // If a block was already in-flight for a different peer, its BLOCKTXN + // response will be dropped. + if (!BlockRequested(peer_id, block_index)) return "Already requested from this peer"; + + // Construct message to request the block + const uint256& hash{block_index.GetBlockHash()}; + std::vector<CInv> invs{CInv(MSG_BLOCK | MSG_WITNESS_FLAG, hash)}; + + // Send block request message to the peer + bool success = m_connman.ForNode(peer_id, [this, &invs](CNode* node) { + const CNetMsgMaker msgMaker(node->GetCommonVersion()); + this->m_connman.PushMessage(node, msgMaker.Make(NetMsgType::GETDATA, invs)); + return true; + }); + + if (!success) return "Peer not fully connected"; + + LogPrint(BCLog::NET, "Requesting block %s from peer=%d\n", + hash.ToString(), peer_id); + return std::nullopt; +} + +std::unique_ptr<PeerManager> PeerManager::make(const CChainParams& chainparams, CConnman& connman, AddrMan& addrman, + BanMan* banman, ChainstateManager& chainman, + CTxMemPool& pool, bool ignore_incoming_txs) +{ + return std::make_unique<PeerManagerImpl>(chainparams, connman, addrman, banman, chainman, pool, ignore_incoming_txs); +} + +PeerManagerImpl::PeerManagerImpl(const CChainParams& chainparams, CConnman& connman, AddrMan& addrman, + BanMan* banman, ChainstateManager& chainman, + CTxMemPool& pool, bool ignore_incoming_txs) + : m_chainparams(chainparams), + m_connman(connman), + m_addrman(addrman), + m_banman(banman), + m_chainman(chainman), + m_mempool(pool), + m_ignore_incoming_txs(ignore_incoming_txs) +{ +} + +void PeerManagerImpl::StartScheduledTasks(CScheduler& scheduler) +{ + // 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([this] { this->CheckForStaleTipAndEvictPeers(); }, std::chrono::seconds{EXTRA_PEER_CHECK_INTERVAL}); + + // schedule next run for 10-15 minutes in the future + const std::chrono::milliseconds delta = 10min + GetRandMillis(5min); + scheduler.scheduleFromNow([&] { ReattemptInitialBroadcast(scheduler); }, delta); +} + +/** + * Evict orphan txn pool entries based on a newly connected + * block, remember the recently confirmed transactions, and delete tracked + * announcements for them. Also save the time of the last tip update. + */ +void PeerManagerImpl::BlockConnected(const std::shared_ptr<const CBlock>& pblock, const CBlockIndex* pindex) +{ + m_orphanage.EraseForBlock(*pblock); + m_last_tip_update = GetTime<std::chrono::seconds>(); + + { + LOCK(m_recent_confirmed_transactions_mutex); + for (const auto& ptx : pblock->vtx) { + m_recent_confirmed_transactions.insert(ptx->GetHash()); + if (ptx->GetHash() != ptx->GetWitnessHash()) { + m_recent_confirmed_transactions.insert(ptx->GetWitnessHash()); + } + } + } + { + LOCK(cs_main); + for (const auto& ptx : pblock->vtx) { + m_txrequest.ForgetTxHash(ptx->GetHash()); + m_txrequest.ForgetTxHash(ptx->GetWitnessHash()); + } + } +} + +void PeerManagerImpl::BlockDisconnected(const std::shared_ptr<const CBlock> &block, const CBlockIndex* pindex) +{ + // To avoid relay problems with transactions that were previously + // confirmed, clear our filter of recently confirmed transactions whenever + // there's a reorg. + // This means that in a 1-block reorg (where 1 block is disconnected and + // then another block reconnected), our filter will drop to having only one + // block's worth of transactions in it, but that should be fine, since + // presumably the most common case of relaying a confirmed transaction + // should be just after a new block containing it is found. + LOCK(m_recent_confirmed_transactions_mutex); + m_recent_confirmed_transactions.reset(); +} + +/** + * Maintain state about the best-seen block and fast-announce a compact block + * to compatible peers. + */ +void PeerManagerImpl::NewPoWValidBlock(const CBlockIndex *pindex, const std::shared_ptr<const CBlock>& pblock) +{ + std::shared_ptr<const CBlockHeaderAndShortTxIDs> pcmpctblock = std::make_shared<const CBlockHeaderAndShortTxIDs> (*pblock, true); + const CNetMsgMaker msgMaker(PROTOCOL_VERSION); + + LOCK(cs_main); + + if (pindex->nHeight <= m_highest_fast_announce) + return; + m_highest_fast_announce = pindex->nHeight; + + bool fWitnessEnabled = DeploymentActiveAt(*pindex, m_chainparams.GetConsensus(), Consensus::DEPLOYMENT_SEGWIT); + uint256 hashBlock(pblock->GetHash()); + const std::shared_future<CSerializedNetMsg> lazy_ser{ + std::async(std::launch::deferred, [&] { return msgMaker.Make(NetMsgType::CMPCTBLOCK, *pcmpctblock); })}; + + { + LOCK(m_most_recent_block_mutex); + m_most_recent_block_hash = hashBlock; + m_most_recent_block = pblock; + m_most_recent_compact_block = pcmpctblock; + m_most_recent_compact_block_has_witnesses = fWitnessEnabled; + } + + m_connman.ForEachNode([this, pindex, fWitnessEnabled, &lazy_ser, &hashBlock](CNode* pnode) EXCLUSIVE_LOCKS_REQUIRED(::cs_main) { + AssertLockHeld(::cs_main); + + if (pnode->GetCommonVersion() < INVALID_CB_NO_BAN_VERSION || pnode->fDisconnect) + return; + ProcessBlockAvailability(pnode->GetId()); + CNodeState &state = *State(pnode->GetId()); + // If the peer has, or we announced to them the previous block already, + // but we don't think they have this one, go ahead and announce it + if (state.fPreferHeaderAndIDs && (!fWitnessEnabled || state.fWantsCmpctWitness) && + !PeerHasHeader(&state, pindex) && PeerHasHeader(&state, pindex->pprev)) { + + LogPrint(BCLog::NET, "%s sending header-and-ids %s to peer=%d\n", "PeerManager::NewPoWValidBlock", + hashBlock.ToString(), pnode->GetId()); + + const CSerializedNetMsg& ser_cmpctblock{lazy_ser.get()}; + m_connman.PushMessage(pnode, ser_cmpctblock.Copy()); + state.pindexBestHeaderSent = pindex; + } + }); +} + +/** + * Update our best height and announce any block hashes which weren't previously + * in m_chainman.ActiveChain() to our peers. + */ +void PeerManagerImpl::UpdatedBlockTip(const CBlockIndex *pindexNew, const CBlockIndex *pindexFork, bool fInitialDownload) +{ + SetBestHeight(pindexNew->nHeight); + SetServiceFlagsIBDCache(!fInitialDownload); + + // Don't relay inventory during initial block download. + if (fInitialDownload) return; + + // Find the hashes of all blocks that weren't previously in the best chain. + std::vector<uint256> vHashes; + const CBlockIndex *pindexToAnnounce = pindexNew; + while (pindexToAnnounce != pindexFork) { + vHashes.push_back(pindexToAnnounce->GetBlockHash()); + pindexToAnnounce = pindexToAnnounce->pprev; + if (vHashes.size() == MAX_BLOCKS_TO_ANNOUNCE) { + // Limit announcements in case of a huge reorganization. + // Rely on the peer's synchronization mechanism in that case. + break; + } + } + + { + LOCK(m_peer_mutex); + for (auto& it : m_peer_map) { + Peer& peer = *it.second; + LOCK(peer.m_block_inv_mutex); + for (const uint256& hash : reverse_iterate(vHashes)) { + peer.m_blocks_for_headers_relay.push_back(hash); + } + } + } + + m_connman.WakeMessageHandler(); +} + +/** + * Handle invalid block rejection and consequent peer discouragement, maintain which + * peers announce compact blocks. + */ +void PeerManagerImpl::BlockChecked(const CBlock& block, const BlockValidationState& state) +{ + LOCK(cs_main); + + const uint256 hash(block.GetHash()); + std::map<uint256, std::pair<NodeId, bool>>::iterator it = mapBlockSource.find(hash); + + // If the block failed validation, we know where it came from and we're still connected + // to that peer, maybe punish. + if (state.IsInvalid() && + it != mapBlockSource.end() && + State(it->second.first)) { + MaybePunishNodeForBlock(/*nodeid=*/ it->second.first, state, /*via_compact_block=*/ !it->second.second); + } + // Check that: + // 1. The block is valid + // 2. We're not in initial block download + // 3. This is currently the best block we're aware of. We haven't updated + // the tip yet so we have no way to check this directly here. Instead we + // just check that there are currently no other blocks in flight. + else if (state.IsValid() && + !m_chainman.ActiveChainstate().IsInitialBlockDownload() && + mapBlocksInFlight.count(hash) == mapBlocksInFlight.size()) { + if (it != mapBlockSource.end()) { + MaybeSetPeerAsAnnouncingHeaderAndIDs(it->second.first); + } + } + if (it != mapBlockSource.end()) + mapBlockSource.erase(it); +} + +////////////////////////////////////////////////////////////////////////////// +// +// Messages +// + + +bool PeerManagerImpl::AlreadyHaveTx(const GenTxid& gtxid) +{ + if (m_chainman.ActiveChain().Tip()->GetBlockHash() != hashRecentRejectsChainTip) { + // If the chain tip has changed previously rejected transactions + // might be now valid, e.g. due to a nLockTime'd tx becoming valid, + // or a double-spend. Reset the rejects filter and give those + // txs a second chance. + hashRecentRejectsChainTip = m_chainman.ActiveChain().Tip()->GetBlockHash(); + m_recent_rejects.reset(); + } + + const uint256& hash = gtxid.GetHash(); + + if (m_orphanage.HaveTx(gtxid)) return true; + + { + LOCK(m_recent_confirmed_transactions_mutex); + if (m_recent_confirmed_transactions.contains(hash)) return true; + } + + return m_recent_rejects.contains(hash) || m_mempool.exists(gtxid); +} + +bool PeerManagerImpl::AlreadyHaveBlock(const uint256& block_hash) +{ + return m_chainman.m_blockman.LookupBlockIndex(block_hash) != nullptr; +} + +void PeerManagerImpl::SendPings() +{ + LOCK(m_peer_mutex); + for(auto& it : m_peer_map) it.second->m_ping_queued = true; +} + +void PeerManagerImpl::RelayTransaction(const uint256& txid, const uint256& wtxid) +{ + LOCK(m_peer_mutex); + for(auto& it : m_peer_map) { + Peer& peer = *it.second; + if (!peer.m_tx_relay) continue; + + const uint256& hash{peer.m_wtxid_relay ? wtxid : txid}; + LOCK(peer.m_tx_relay->m_tx_inventory_mutex); + if (!peer.m_tx_relay->m_tx_inventory_known_filter.contains(hash)) { + peer.m_tx_relay->m_tx_inventory_to_send.insert(hash); + } + }; +} + +void PeerManagerImpl::RelayAddress(NodeId originator, + const CAddress& addr, + bool fReachable) +{ + // We choose the same nodes within a given 24h window (if the list of connected + // nodes does not change) and we don't relay to nodes that already know an + // address. So within 24h we will likely relay a given address once. This is to + // prevent a peer from unjustly giving their address better propagation by sending + // it to us repeatedly. + + if (!fReachable && !addr.IsRelayable()) return; + + // Relay to a limited number of other nodes + // Use deterministic randomness to send to the same nodes for 24 hours + // at a time so the m_addr_knowns of the chosen nodes prevent repeats + const uint64_t hash_addr{CServiceHash(0, 0)(addr)}; + const auto current_time{GetTime<std::chrono::seconds>()}; + // Adding address hash makes exact rotation time different per address, while preserving periodicity. + const uint64_t time_addr{(static_cast<uint64_t>(count_seconds(current_time)) + hash_addr) / count_seconds(ROTATE_ADDR_RELAY_DEST_INTERVAL)}; + const CSipHasher hasher{m_connman.GetDeterministicRandomizer(RANDOMIZER_ID_ADDRESS_RELAY) + .Write(hash_addr) + .Write(time_addr)}; + FastRandomContext insecure_rand; + + // Relay reachable addresses to 2 peers. Unreachable addresses are relayed randomly to 1 or 2 peers. + unsigned int nRelayNodes = (fReachable || (hasher.Finalize() & 1)) ? 2 : 1; + + std::array<std::pair<uint64_t, Peer*>, 2> best{{{0, nullptr}, {0, nullptr}}}; + assert(nRelayNodes <= best.size()); + + LOCK(m_peer_mutex); + + for (auto& [id, peer] : m_peer_map) { + if (peer->m_addr_relay_enabled && id != originator && IsAddrCompatible(*peer, addr)) { + uint64_t hashKey = CSipHasher(hasher).Write(id).Finalize(); + for (unsigned int i = 0; i < nRelayNodes; i++) { + if (hashKey > best[i].first) { + std::copy(best.begin() + i, best.begin() + nRelayNodes - 1, best.begin() + i + 1); + best[i] = std::make_pair(hashKey, peer.get()); + break; + } + } + } + }; + + for (unsigned int i = 0; i < nRelayNodes && best[i].first != 0; i++) { + PushAddress(*best[i].second, addr, insecure_rand); + } +} + +void PeerManagerImpl::ProcessGetBlockData(CNode& pfrom, Peer& peer, const CInv& inv) +{ + std::shared_ptr<const CBlock> a_recent_block; + std::shared_ptr<const CBlockHeaderAndShortTxIDs> a_recent_compact_block; + bool fWitnessesPresentInARecentCompactBlock; + { + LOCK(m_most_recent_block_mutex); + a_recent_block = m_most_recent_block; + a_recent_compact_block = m_most_recent_compact_block; + fWitnessesPresentInARecentCompactBlock = m_most_recent_compact_block_has_witnesses; + } + + bool need_activate_chain = false; + { + LOCK(cs_main); + const CBlockIndex* pindex = m_chainman.m_blockman.LookupBlockIndex(inv.hash); + if (pindex) { + if (pindex->HaveTxsDownloaded() && !pindex->IsValid(BLOCK_VALID_SCRIPTS) && + pindex->IsValid(BLOCK_VALID_TREE)) { + // If we have the block and all of its parents, but have not yet validated it, + // we might be in the middle of connecting it (ie in the unlock of cs_main + // before ActivateBestChain but after AcceptBlock). + // In this case, we need to run ActivateBestChain prior to checking the relay + // conditions below. + need_activate_chain = true; + } + } + } // release cs_main before calling ActivateBestChain + if (need_activate_chain) { + BlockValidationState state; + if (!m_chainman.ActiveChainstate().ActivateBestChain(state, a_recent_block)) { + LogPrint(BCLog::NET, "failed to activate chain (%s)\n", state.ToString()); + } + } + + LOCK(cs_main); + const CBlockIndex* pindex = m_chainman.m_blockman.LookupBlockIndex(inv.hash); + if (!pindex) { + return; + } + if (!BlockRequestAllowed(pindex)) { + LogPrint(BCLog::NET, "%s: ignoring request from peer=%i for old block that isn't in the main chain\n", __func__, pfrom.GetId()); + return; + } + const CNetMsgMaker msgMaker(pfrom.GetCommonVersion()); + // disconnect node in case we have reached the outbound limit for serving historical blocks + if (m_connman.OutboundTargetReached(true) && + (((m_chainman.m_best_header != nullptr) && (m_chainman.m_best_header->GetBlockTime() - pindex->GetBlockTime() > HISTORICAL_BLOCK_AGE)) || inv.IsMsgFilteredBlk()) && + !pfrom.HasPermission(NetPermissionFlags::Download) // nodes with the download permission may exceed target + ) { + LogPrint(BCLog::NET, "historical block serving limit reached, disconnect peer=%d\n", pfrom.GetId()); + pfrom.fDisconnect = true; + return; + } + // Avoid leaking prune-height by never sending blocks below the NODE_NETWORK_LIMITED threshold + if (!pfrom.HasPermission(NetPermissionFlags::NoBan) && ( + (((pfrom.GetLocalServices() & NODE_NETWORK_LIMITED) == NODE_NETWORK_LIMITED) && ((pfrom.GetLocalServices() & NODE_NETWORK) != NODE_NETWORK) && (m_chainman.ActiveChain().Tip()->nHeight - pindex->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, disconnect peer=%d\n", pfrom.GetId()); + //disconnect node and prevent it from stalling (would otherwise wait for the missing block) + pfrom.fDisconnect = true; + return; + } + // Pruned nodes may have deleted the block, so check whether + // it's available before trying to send. + if (!(pindex->nStatus & BLOCK_HAVE_DATA)) { + return; + } + std::shared_ptr<const CBlock> pblock; + if (a_recent_block && a_recent_block->GetHash() == pindex->GetBlockHash()) { + pblock = a_recent_block; + } else if (inv.IsMsgWitnessBlk()) { + // Fast-path: in this case it is possible to serve the block directly from disk, + // as the network format matches the format on disk + std::vector<uint8_t> block_data; + if (!ReadRawBlockFromDisk(block_data, pindex->GetBlockPos(), m_chainparams.MessageStart())) { + assert(!"cannot load block from disk"); + } + m_connman.PushMessage(&pfrom, msgMaker.Make(NetMsgType::BLOCK, Span{block_data})); + // Don't set pblock as we've sent the block + } else { + // Send block from disk + std::shared_ptr<CBlock> pblockRead = std::make_shared<CBlock>(); + if (!ReadBlockFromDisk(*pblockRead, pindex, m_chainparams.GetConsensus())) { + assert(!"cannot load block from disk"); + } + pblock = pblockRead; + } + if (pblock) { + if (inv.IsMsgBlk()) { + m_connman.PushMessage(&pfrom, msgMaker.Make(SERIALIZE_TRANSACTION_NO_WITNESS, NetMsgType::BLOCK, *pblock)); + } else if (inv.IsMsgWitnessBlk()) { + m_connman.PushMessage(&pfrom, msgMaker.Make(NetMsgType::BLOCK, *pblock)); + } else if (inv.IsMsgFilteredBlk()) { + bool sendMerkleBlock = false; + CMerkleBlock merkleBlock; + if (peer.m_tx_relay != nullptr) { + LOCK(peer.m_tx_relay->m_bloom_filter_mutex); + if (peer.m_tx_relay->m_bloom_filter) { + sendMerkleBlock = true; + merkleBlock = CMerkleBlock(*pblock, *peer.m_tx_relay->m_bloom_filter); + } + } + if (sendMerkleBlock) { + m_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 - + // they must either disconnect and retry or request the full block. + // Thus, the protocol spec specified allows for us to provide duplicate txn here, + // however we MUST always provide at least what the remote peer needs + typedef std::pair<unsigned int, uint256> PairType; + for (PairType& pair : merkleBlock.vMatchedTxn) + m_connman.PushMessage(&pfrom, msgMaker.Make(SERIALIZE_TRANSACTION_NO_WITNESS, NetMsgType::TX, *pblock->vtx[pair.first])); + } + // else + // no response + } else if (inv.IsMsgCmpctBlk()) { + // If a peer is asking for old blocks, we're almost guaranteed + // they won't have a useful mempool to match against a compact block, + // and we don't feel like constructing the object for them, so + // instead we respond with the full, non-compact block. + bool fPeerWantsWitness = State(pfrom.GetId())->fWantsCmpctWitness; + int nSendFlags = fPeerWantsWitness ? 0 : SERIALIZE_TRANSACTION_NO_WITNESS; + if (CanDirectFetch() && pindex->nHeight >= m_chainman.ActiveChain().Height() - MAX_CMPCTBLOCK_DEPTH) { + if ((fPeerWantsWitness || !fWitnessesPresentInARecentCompactBlock) && a_recent_compact_block && a_recent_compact_block->header.GetHash() == pindex->GetBlockHash()) { + m_connman.PushMessage(&pfrom, msgMaker.Make(nSendFlags, NetMsgType::CMPCTBLOCK, *a_recent_compact_block)); + } else { + CBlockHeaderAndShortTxIDs cmpctblock(*pblock, fPeerWantsWitness); + m_connman.PushMessage(&pfrom, msgMaker.Make(nSendFlags, NetMsgType::CMPCTBLOCK, cmpctblock)); + } + } else { + m_connman.PushMessage(&pfrom, msgMaker.Make(nSendFlags, NetMsgType::BLOCK, *pblock)); + } + } + } + + { + LOCK(peer.m_block_inv_mutex); + // Trigger the peer node to send a getblocks request for the next batch of inventory + if (inv.hash == peer.m_continuation_block) { + // Send immediately. This must send even if redundant, + // and we want it right after the last block so they don't + // wait for other stuff first. + std::vector<CInv> vInv; + vInv.push_back(CInv(MSG_BLOCK, m_chainman.ActiveChain().Tip()->GetBlockHash())); + m_connman.PushMessage(&pfrom, msgMaker.Make(NetMsgType::INV, vInv)); + peer.m_continuation_block.SetNull(); + } + } +} + +CTransactionRef PeerManagerImpl::FindTxForGetData(const CNode& peer, const GenTxid& gtxid, const std::chrono::seconds mempool_req, const std::chrono::seconds now) +{ + auto txinfo = m_mempool.info(gtxid); + if (txinfo.tx) { + // If a TX could have been INVed in reply to a MEMPOOL request, + // or is older than UNCONDITIONAL_RELAY_DELAY, permit the request + // unconditionally. + if ((mempool_req.count() && txinfo.m_time <= mempool_req) || txinfo.m_time <= now - UNCONDITIONAL_RELAY_DELAY) { + return std::move(txinfo.tx); + } + } + + { + LOCK(cs_main); + // Otherwise, the transaction must have been announced recently. + if (State(peer.GetId())->m_recently_announced_invs.contains(gtxid.GetHash())) { + // If it was, it can be relayed from either the mempool... + if (txinfo.tx) return std::move(txinfo.tx); + // ... or the relay pool. + auto mi = mapRelay.find(gtxid.GetHash()); + if (mi != mapRelay.end()) return mi->second; + } + } + + return {}; +} + +void PeerManagerImpl::ProcessGetData(CNode& pfrom, Peer& peer, const std::atomic<bool>& interruptMsgProc) +{ + AssertLockNotHeld(cs_main); + + std::deque<CInv>::iterator it = peer.m_getdata_requests.begin(); + std::vector<CInv> vNotFound; + const CNetMsgMaker msgMaker(pfrom.GetCommonVersion()); + + const auto now{GetTime<std::chrono::seconds>()}; + // Get last mempool request time + const auto mempool_req = peer.m_tx_relay != nullptr ? peer.m_tx_relay->m_last_mempool_req.load() : std::chrono::seconds::min(); + + // Process as many TX items from the front of the getdata queue as + // possible, since they're common and it's efficient to batch process + // them. + while (it != peer.m_getdata_requests.end() && it->IsGenTxMsg()) { + if (interruptMsgProc) return; + // The send buffer provides backpressure. If there's no space in + // the buffer, pause processing until the next call. + if (pfrom.fPauseSend) break; + + const CInv &inv = *it++; + + if (peer.m_tx_relay == nullptr) { + // Ignore GETDATA requests for transactions from blocks-only peers. + continue; + } + + CTransactionRef tx = FindTxForGetData(pfrom, ToGenTxid(inv), mempool_req, now); + if (tx) { + // WTX and WITNESS_TX imply we serialize with witness + int nSendFlags = (inv.IsMsgTx() ? SERIALIZE_TRANSACTION_NO_WITNESS : 0); + m_connman.PushMessage(&pfrom, msgMaker.Make(nSendFlags, NetMsgType::TX, *tx)); + m_mempool.RemoveUnbroadcastTx(tx->GetHash()); + // As we're going to send tx, make sure its unconfirmed parents are made requestable. + std::vector<uint256> parent_ids_to_add; + { + LOCK(m_mempool.cs); + auto txiter = m_mempool.GetIter(tx->GetHash()); + if (txiter) { + const CTxMemPoolEntry::Parents& parents = (*txiter)->GetMemPoolParentsConst(); + parent_ids_to_add.reserve(parents.size()); + for (const CTxMemPoolEntry& parent : parents) { + if (parent.GetTime() > now - UNCONDITIONAL_RELAY_DELAY) { + parent_ids_to_add.push_back(parent.GetTx().GetHash()); + } + } + } + } + for (const uint256& parent_txid : parent_ids_to_add) { + // Relaying a transaction with a recent but unconfirmed parent. + if (WITH_LOCK(peer.m_tx_relay->m_tx_inventory_mutex, return !peer.m_tx_relay->m_tx_inventory_known_filter.contains(parent_txid))) { + LOCK(cs_main); + State(pfrom.GetId())->m_recently_announced_invs.insert(parent_txid); + } + } + } else { + vNotFound.push_back(inv); + } + } + + // Only process one BLOCK item per call, since they're uncommon and can be + // expensive to process. + if (it != peer.m_getdata_requests.end() && !pfrom.fPauseSend) { + const CInv &inv = *it++; + if (inv.IsGenBlkMsg()) { + ProcessGetBlockData(pfrom, peer, inv); + } + // else: If the first item on the queue is an unknown type, we erase it + // and continue processing the queue on the next call. + } + + peer.m_getdata_requests.erase(peer.m_getdata_requests.begin(), it); + + if (!vNotFound.empty()) { + // Let the peer know that we didn't find what it asked for, so it doesn't + // have to wait around forever. + // SPV clients care about this message: it's needed when they are + // recursively walking the dependencies of relevant unconfirmed + // transactions. SPV clients want to 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. + // Also, other nodes can use these messages to automatically request a + // transaction from some other peer that annnounced it, and stop + // waiting for us to respond. + // In normal operation, we often send NOTFOUND messages for parents of + // transactions that we relay; if a peer is missing a parent, they may + // assume we have them and request the parents from us. + m_connman.PushMessage(&pfrom, msgMaker.Make(NetMsgType::NOTFOUND, vNotFound)); + } +} + +uint32_t PeerManagerImpl::GetFetchFlags(const CNode& pfrom) const EXCLUSIVE_LOCKS_REQUIRED(cs_main) +{ + uint32_t nFetchFlags = 0; + if (State(pfrom.GetId())->fHaveWitness) { + nFetchFlags |= MSG_WITNESS_FLAG; + } + return nFetchFlags; +} + +void PeerManagerImpl::SendBlockTransactions(CNode& pfrom, const CBlock& block, const BlockTransactionsRequest& req) +{ + BlockTransactions resp(req); + for (size_t i = 0; i < req.indexes.size(); i++) { + if (req.indexes[i] >= block.vtx.size()) { + Misbehaving(pfrom.GetId(), 100, "getblocktxn with out-of-bounds tx indices"); + return; + } + resp.txn[i] = block.vtx[req.indexes[i]]; + } + LOCK(cs_main); + const CNetMsgMaker msgMaker(pfrom.GetCommonVersion()); + int nSendFlags = State(pfrom.GetId())->fWantsCmpctWitness ? 0 : SERIALIZE_TRANSACTION_NO_WITNESS; + m_connman.PushMessage(&pfrom, msgMaker.Make(nSendFlags, NetMsgType::BLOCKTXN, resp)); +} + +void PeerManagerImpl::ProcessHeadersMessage(CNode& pfrom, const Peer& peer, + const std::vector<CBlockHeader>& headers, + bool via_compact_block) +{ + const CNetMsgMaker msgMaker(pfrom.GetCommonVersion()); + size_t nCount = headers.size(); + + if (nCount == 0) { + // Nothing interesting. Stop asking this peers for more headers. + return; + } + + 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 (!m_chainman.m_blockman.LookupBlockIndex(headers[0].hashPrevBlock) && nCount < MAX_BLOCKS_TO_ANNOUNCE) { + nodestate->nUnconnectingHeaders++; + m_connman.PushMessage(&pfrom, msgMaker.Make(NetMsgType::GETHEADERS, m_chainman.ActiveChain().GetLocator(m_chainman.m_best_header), 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(), + m_chainman.m_best_header->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, strprintf("%d non-connecting headers", nodestate->nUnconnectingHeaders)); + } + return; + } + + uint256 hashLastBlock; + for (const CBlockHeader& header : headers) { + if (!hashLastBlock.IsNull() && header.hashPrevBlock != hashLastBlock) { + Misbehaving(pfrom.GetId(), 20, "non-continuous headers sequence"); + return; + } + 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 (!m_chainman.m_blockman.LookupBlockIndex(hashLastBlock)) { + received_new_header = true; + } + } + + BlockValidationState state; + if (!m_chainman.ProcessNewBlockHeaders(headers, state, m_chainparams, &pindexLast)) { + if (state.IsInvalid()) { + MaybePunishNodeForBlock(pfrom.GetId(), state, via_compact_block, "invalid header received"); + return; + } + } + + { + LOCK(cs_main); + CNodeState *nodestate = State(pfrom.GetId()); + if (nodestate->nUnconnectingHeaders > 0) { + LogPrint(BCLog::NET, "peer=%d: resetting nUnconnectingHeaders (%d -> 0)\n", pfrom.GetId(), nodestate->nUnconnectingHeaders); + } + nodestate->nUnconnectingHeaders = 0; + + assert(pindexLast); + UpdateBlockAvailability(pfrom.GetId(), pindexLast->GetBlockHash()); + + // From here, pindexBestKnownBlock should be guaranteed to be non-null, + // because it is set in UpdateBlockAvailability. Some nullptr checks + // are still present, however, as belt-and-suspenders. + + if (received_new_header && pindexLast->nChainWork > m_chainman.ActiveChain().Tip()->nChainWork) { + nodestate->m_last_block_announcement = GetTime(); + } + + if (nCount == MAX_HEADERS_RESULTS) { + // Headers message had its maximum size; the peer may have more headers. + // TODO: optimize: if pindexLast is an ancestor of m_chainman.ActiveChain().Tip or m_chainman.m_best_header, continue + // from there instead. + LogPrint(BCLog::NET, "more getheaders (%d) to end to peer=%d (startheight:%d)\n", + pindexLast->nHeight, pfrom.GetId(), peer.m_starting_height); + m_connman.PushMessage(&pfrom, msgMaker.Make(NetMsgType::GETHEADERS, m_chainman.ActiveChain().GetLocator(pindexLast), uint256())); + } + + // If this set of headers is valid and ends in a block with at least as + // much work as our tip, download as much as possible. + if (CanDirectFetch() && pindexLast->IsValid(BLOCK_VALID_TREE) && m_chainman.ActiveChain().Tip()->nChainWork <= pindexLast->nChainWork) { + 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 && !m_chainman.ActiveChain().Contains(pindexWalk) && vToFetch.size() <= MAX_BLOCKS_IN_TRANSIT_PER_PEER) { + if (!(pindexWalk->nStatus & BLOCK_HAVE_DATA) && + !IsBlockRequested(pindexWalk->GetBlockHash()) && + (!DeploymentActiveAt(*pindexWalk, m_chainparams.GetConsensus(), Consensus::DEPLOYMENT_SEGWIT) || 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 (!m_chainman.ActiveChain().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())); + BlockRequested(pfrom.GetId(), *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 (!m_ignore_incoming_txs && + 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); + } + m_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 (m_chainman.ActiveChainstate().IsInitialBlockDownload() && nCount != MAX_HEADERS_RESULTS) { + // When nCount < MAX_HEADERS_RESULTS, we know we have no more + // headers to fetch from this peer. + if (nodestate->pindexBestKnownBlock && nodestate->pindexBestKnownBlock->nChainWork < nMinimumChainWork) { + // This peer has too little work on their headers chain to help + // us sync -- disconnect if it is an outbound disconnection + // candidate. + // Note: We compare their tip to nMinimumChainWork (rather than + // m_chainman.ActiveChain().Tip()) because we won't start block download + // until we have a headers chain that has at least + // nMinimumChainWork, even if a peer has a chain past our tip, + // as an anti-DoS measure. + if (pfrom.IsOutboundOrBlockRelayConn()) { + LogPrintf("Disconnecting outbound peer %d -- headers chain has insufficient work\n", pfrom.GetId()); + pfrom.fDisconnect = true; + } + } + } + + // If this is an outbound full-relay peer, check to see if we should protect + // it from the bad/lagging chain logic. + // Note that outbound block-relay peers are excluded from this protection, and + // thus always subject to eviction under the bad/lagging chain logic. + // See ChainSyncTimeoutState. + if (!pfrom.fDisconnect && pfrom.IsFullOutboundConn() && nodestate->pindexBestKnownBlock != nullptr) { + if (m_outbound_peers_with_protect_from_disconnect < MAX_OUTBOUND_PEERS_TO_PROTECT_FROM_DISCONNECT && nodestate->pindexBestKnownBlock->nChainWork >= m_chainman.ActiveChain().Tip()->nChainWork && !nodestate->m_chain_sync.m_protect) { + LogPrint(BCLog::NET, "Protecting outbound peer=%d from eviction\n", pfrom.GetId()); + nodestate->m_chain_sync.m_protect = true; + ++m_outbound_peers_with_protect_from_disconnect; + } + } + } + + return; +} + +/** + * Reconsider orphan transactions after a parent has been accepted to the mempool. + * + * @param[in,out] orphan_work_set The set of orphan transactions to reconsider. Generally only one + * orphan will be reconsidered on each call of this function. This set + * may be added to if accepting an orphan causes its children to be + * reconsidered. + */ +void PeerManagerImpl::ProcessOrphanTx(std::set<uint256>& orphan_work_set) +{ + AssertLockHeld(cs_main); + AssertLockHeld(g_cs_orphans); + + while (!orphan_work_set.empty()) { + const uint256 orphanHash = *orphan_work_set.begin(); + orphan_work_set.erase(orphan_work_set.begin()); + + const auto [porphanTx, from_peer] = m_orphanage.GetTx(orphanHash); + if (porphanTx == nullptr) continue; + + const MempoolAcceptResult result = m_chainman.ProcessTransaction(porphanTx); + const TxValidationState& state = result.m_state; + + if (result.m_result_type == MempoolAcceptResult::ResultType::VALID) { + LogPrint(BCLog::MEMPOOL, " accepted orphan tx %s\n", orphanHash.ToString()); + RelayTransaction(orphanHash, porphanTx->GetWitnessHash()); + m_orphanage.AddChildrenToWorkSet(*porphanTx, orphan_work_set); + m_orphanage.EraseTx(orphanHash); + for (const CTransactionRef& removedTx : result.m_replaced_transactions.value()) { + AddToCompactExtraTransactions(removedTx); + } + break; + } else if (state.GetResult() != TxValidationResult::TX_MISSING_INPUTS) { + if (state.IsInvalid()) { + LogPrint(BCLog::MEMPOOL, " invalid orphan tx %s from peer=%d. %s\n", + orphanHash.ToString(), + from_peer, + state.ToString()); + // Maybe punish peer that gave us an invalid orphan tx + MaybePunishNodeForTx(from_peer, state); + } + // Has inputs but not accepted to mempool + // Probably non-standard or insufficient fee + LogPrint(BCLog::MEMPOOL, " removed orphan tx %s\n", orphanHash.ToString()); + if (state.GetResult() != TxValidationResult::TX_WITNESS_STRIPPED) { + // We can add the wtxid of this transaction to our reject filter. + // Do not add txids of witness transactions or witness-stripped + // transactions to the filter, as they can have been malleated; + // adding such txids to the reject filter would potentially + // interfere with relay of valid transactions from peers that + // do not support wtxid-based relay. See + // https://github.com/bitcoin/bitcoin/issues/8279 for details. + // We can remove this restriction (and always add wtxids to + // the filter even for witness stripped transactions) once + // wtxid-based relay is broadly deployed. + // See also comments in https://github.com/bitcoin/bitcoin/pull/18044#discussion_r443419034 + // for concerns around weakening security of unupgraded nodes + // if we start doing this too early. + m_recent_rejects.insert(porphanTx->GetWitnessHash()); + // If the transaction failed for TX_INPUTS_NOT_STANDARD, + // then we know that the witness was irrelevant to the policy + // failure, since this check depends only on the txid + // (the scriptPubKey being spent is covered by the txid). + // Add the txid to the reject filter to prevent repeated + // processing of this transaction in the event that child + // transactions are later received (resulting in + // parent-fetching by txid via the orphan-handling logic). + if (state.GetResult() == TxValidationResult::TX_INPUTS_NOT_STANDARD && porphanTx->GetWitnessHash() != porphanTx->GetHash()) { + // We only add the txid if it differs from the wtxid, to + // avoid wasting entries in the rolling bloom filter. + m_recent_rejects.insert(porphanTx->GetHash()); + } + } + m_orphanage.EraseTx(orphanHash); + break; + } + } +} + +bool PeerManagerImpl::PrepareBlockFilterRequest(CNode& peer, + BlockFilterType filter_type, uint32_t start_height, + const uint256& stop_hash, uint32_t max_height_diff, + const CBlockIndex*& stop_index, + BlockFilterIndex*& filter_index) +{ + const bool supported_filter_type = + (filter_type == BlockFilterType::BASIC && + (peer.GetLocalServices() & NODE_COMPACT_FILTERS)); + if (!supported_filter_type) { + LogPrint(BCLog::NET, "peer %d requested unsupported block filter type: %d\n", + peer.GetId(), static_cast<uint8_t>(filter_type)); + peer.fDisconnect = true; + return false; + } + + { + LOCK(cs_main); + stop_index = m_chainman.m_blockman.LookupBlockIndex(stop_hash); + + // Check that the stop block exists and the peer would be allowed to fetch it. + if (!stop_index || !BlockRequestAllowed(stop_index)) { + LogPrint(BCLog::NET, "peer %d requested invalid block hash: %s\n", + peer.GetId(), stop_hash.ToString()); + peer.fDisconnect = true; + return false; + } + } + + uint32_t stop_height = stop_index->nHeight; + if (start_height > stop_height) { + LogPrint(BCLog::NET, "peer %d sent invalid getcfilters/getcfheaders with " /* Continued */ + "start height %d and stop height %d\n", + peer.GetId(), start_height, stop_height); + peer.fDisconnect = true; + return false; + } + if (stop_height - start_height >= max_height_diff) { + LogPrint(BCLog::NET, "peer %d requested too many cfilters/cfheaders: %d / %d\n", + peer.GetId(), stop_height - start_height + 1, max_height_diff); + peer.fDisconnect = true; + return false; + } + + filter_index = GetBlockFilterIndex(filter_type); + if (!filter_index) { + LogPrint(BCLog::NET, "Filter index for supported type %s not found\n", BlockFilterTypeName(filter_type)); + return false; + } + + return true; +} + +void PeerManagerImpl::ProcessGetCFilters(CNode& peer, CDataStream& vRecv) +{ + uint8_t filter_type_ser; + uint32_t start_height; + uint256 stop_hash; + + vRecv >> filter_type_ser >> start_height >> stop_hash; + + const BlockFilterType filter_type = static_cast<BlockFilterType>(filter_type_ser); + + const CBlockIndex* stop_index; + BlockFilterIndex* filter_index; + if (!PrepareBlockFilterRequest(peer, filter_type, start_height, stop_hash, + MAX_GETCFILTERS_SIZE, stop_index, filter_index)) { + return; + } + + std::vector<BlockFilter> filters; + if (!filter_index->LookupFilterRange(start_height, stop_index, filters)) { + LogPrint(BCLog::NET, "Failed to find block filter in index: filter_type=%s, start_height=%d, stop_hash=%s\n", + BlockFilterTypeName(filter_type), start_height, stop_hash.ToString()); + return; + } + + for (const auto& filter : filters) { + CSerializedNetMsg msg = CNetMsgMaker(peer.GetCommonVersion()) + .Make(NetMsgType::CFILTER, filter); + m_connman.PushMessage(&peer, std::move(msg)); + } +} + +void PeerManagerImpl::ProcessGetCFHeaders(CNode& peer, CDataStream& vRecv) +{ + uint8_t filter_type_ser; + uint32_t start_height; + uint256 stop_hash; + + vRecv >> filter_type_ser >> start_height >> stop_hash; + + const BlockFilterType filter_type = static_cast<BlockFilterType>(filter_type_ser); + + const CBlockIndex* stop_index; + BlockFilterIndex* filter_index; + if (!PrepareBlockFilterRequest(peer, filter_type, start_height, stop_hash, + MAX_GETCFHEADERS_SIZE, stop_index, filter_index)) { + return; + } + + uint256 prev_header; + if (start_height > 0) { + const CBlockIndex* const prev_block = + stop_index->GetAncestor(static_cast<int>(start_height - 1)); + if (!filter_index->LookupFilterHeader(prev_block, prev_header)) { + LogPrint(BCLog::NET, "Failed to find block filter header in index: filter_type=%s, block_hash=%s\n", + BlockFilterTypeName(filter_type), prev_block->GetBlockHash().ToString()); + return; + } + } + + std::vector<uint256> filter_hashes; + if (!filter_index->LookupFilterHashRange(start_height, stop_index, filter_hashes)) { + LogPrint(BCLog::NET, "Failed to find block filter hashes in index: filter_type=%s, start_height=%d, stop_hash=%s\n", + BlockFilterTypeName(filter_type), start_height, stop_hash.ToString()); + return; + } + + CSerializedNetMsg msg = CNetMsgMaker(peer.GetCommonVersion()) + .Make(NetMsgType::CFHEADERS, + filter_type_ser, + stop_index->GetBlockHash(), + prev_header, + filter_hashes); + m_connman.PushMessage(&peer, std::move(msg)); +} + +void PeerManagerImpl::ProcessGetCFCheckPt(CNode& peer, CDataStream& vRecv) +{ + uint8_t filter_type_ser; + uint256 stop_hash; + + vRecv >> filter_type_ser >> stop_hash; + + const BlockFilterType filter_type = static_cast<BlockFilterType>(filter_type_ser); + + const CBlockIndex* stop_index; + BlockFilterIndex* filter_index; + if (!PrepareBlockFilterRequest(peer, filter_type, /*start_height=*/0, stop_hash, + /*max_height_diff=*/std::numeric_limits<uint32_t>::max(), + stop_index, filter_index)) { + return; + } + + std::vector<uint256> headers(stop_index->nHeight / CFCHECKPT_INTERVAL); + + // Populate headers. + const CBlockIndex* block_index = stop_index; + for (int i = headers.size() - 1; i >= 0; i--) { + int height = (i + 1) * CFCHECKPT_INTERVAL; + block_index = block_index->GetAncestor(height); + + if (!filter_index->LookupFilterHeader(block_index, headers[i])) { + LogPrint(BCLog::NET, "Failed to find block filter header in index: filter_type=%s, block_hash=%s\n", + BlockFilterTypeName(filter_type), block_index->GetBlockHash().ToString()); + return; + } + } + + CSerializedNetMsg msg = CNetMsgMaker(peer.GetCommonVersion()) + .Make(NetMsgType::CFCHECKPT, + filter_type_ser, + stop_index->GetBlockHash(), + headers); + m_connman.PushMessage(&peer, std::move(msg)); +} + +void PeerManagerImpl::ProcessBlock(CNode& node, const std::shared_ptr<const CBlock>& block, bool force_processing) +{ + bool new_block{false}; + m_chainman.ProcessNewBlock(m_chainparams, block, force_processing, &new_block); + if (new_block) { + node.m_last_block_time = GetTime<std::chrono::seconds>(); + } else { + LOCK(cs_main); + mapBlockSource.erase(block->GetHash()); + } +} + +void PeerManagerImpl::ProcessMessage(CNode& pfrom, const std::string& msg_type, CDataStream& vRecv, + const std::chrono::microseconds time_received, + const std::atomic<bool>& interruptMsgProc) +{ + LogPrint(BCLog::NET, "received: %s (%u bytes) peer=%d\n", SanitizeString(msg_type), vRecv.size(), pfrom.GetId()); + + PeerRef peer = GetPeerRef(pfrom.GetId()); + if (peer == nullptr) return; + + if (msg_type == NetMsgType::VERSION) { + if (pfrom.nVersion != 0) { + LogPrint(BCLog::NET, "redundant version message from peer=%d\n", pfrom.GetId()); + return; + } + + int64_t nTime; + CService addrMe; + uint64_t nNonce = 1; + ServiceFlags nServices; + int nVersion; + std::string cleanSubVer; + int starting_height = -1; + bool fRelay = true; + + vRecv >> nVersion >> Using<CustomUintFormatter<8>>(nServices) >> nTime; + if (nTime < 0) { + nTime = 0; + } + vRecv.ignore(8); // Ignore the addrMe service bits sent by the peer + vRecv >> addrMe; + if (!pfrom.IsInboundConn()) + { + m_addrman.SetServices(pfrom.addr, nServices); + } + if (pfrom.ExpectServicesFromConn() && !HasAllDesirableServiceFlags(nServices)) + { + LogPrint(BCLog::NET, "peer=%d does not offer the expected services (%08x offered, %08x expected); disconnecting\n", pfrom.GetId(), nServices, GetDesirableServiceFlags(nServices)); + pfrom.fDisconnect = true; + return; + } + + if (nVersion < MIN_PEER_PROTO_VERSION) { + // disconnect from peers older than this proto version + LogPrint(BCLog::NET, "peer=%d using obsolete version %i; disconnecting\n", pfrom.GetId(), nVersion); + pfrom.fDisconnect = true; + return; + } + + if (!vRecv.empty()) { + // The version message includes information about the sending node which we don't use: + // - 8 bytes (service bits) + // - 16 bytes (ipv6 address) + // - 2 bytes (port) + vRecv.ignore(26); + vRecv >> nNonce; + } + if (!vRecv.empty()) { + std::string strSubVer; + vRecv >> LIMITED_STRING(strSubVer, MAX_SUBVERSION_LENGTH); + cleanSubVer = SanitizeString(strSubVer); + } + if (!vRecv.empty()) { + vRecv >> starting_height; + } + if (!vRecv.empty()) + vRecv >> fRelay; + // Disconnect if we connected to ourself + if (pfrom.IsInboundConn() && !m_connman.CheckIncomingNonce(nNonce)) + { + LogPrintf("connected to self at %s, disconnecting\n", pfrom.addr.ToString()); + pfrom.fDisconnect = true; + return; + } + + if (pfrom.IsInboundConn() && addrMe.IsRoutable()) + { + SeenLocal(addrMe); + } + + // Inbound peers send us their version message when they connect. + // We send our version message in response. + if (pfrom.IsInboundConn()) { + PushNodeVersion(pfrom, *peer); + } + + // Change version + const int greatest_common_version = std::min(nVersion, PROTOCOL_VERSION); + pfrom.SetCommonVersion(greatest_common_version); + pfrom.nVersion = nVersion; + + const CNetMsgMaker msg_maker(greatest_common_version); + + if (greatest_common_version >= WTXID_RELAY_VERSION) { + m_connman.PushMessage(&pfrom, msg_maker.Make(NetMsgType::WTXIDRELAY)); + } + + // Signal ADDRv2 support (BIP155). + if (greatest_common_version >= 70016) { + // BIP155 defines addrv2 and sendaddrv2 for all protocol versions, but some + // implementations reject messages they don't know. As a courtesy, don't send + // it to nodes with a version before 70016, as no software is known to support + // BIP155 that doesn't announce at least that protocol version number. + m_connman.PushMessage(&pfrom, msg_maker.Make(NetMsgType::SENDADDRV2)); + } + + m_connman.PushMessage(&pfrom, msg_maker.Make(NetMsgType::VERACK)); + + pfrom.nServices = nServices; + pfrom.SetAddrLocal(addrMe); + { + LOCK(pfrom.m_subver_mutex); + pfrom.cleanSubVer = cleanSubVer; + } + peer->m_starting_height = starting_height; + + // set nodes not relaying blocks and tx and not serving (parts) of the historical blockchain as "clients" + pfrom.fClient = (!(nServices & NODE_NETWORK) && !(nServices & NODE_NETWORK_LIMITED)); + + // set nodes not capable of serving the complete blockchain history as "limited nodes" + pfrom.m_limited_node = (!(nServices & NODE_NETWORK) && (nServices & NODE_NETWORK_LIMITED)); + + if (peer->m_tx_relay != nullptr) { + { + LOCK(peer->m_tx_relay->m_bloom_filter_mutex); + peer->m_tx_relay->m_relay_txs = fRelay; // set to true after we get the first filter* message + } + if (fRelay) pfrom.m_relays_txs = true; + } + + if((nServices & NODE_WITNESS)) + { + LOCK(cs_main); + State(pfrom.GetId())->fHaveWitness = true; + } + + // Potentially mark this peer as a preferred download peer. + { + LOCK(cs_main); + CNodeState* state = State(pfrom.GetId()); + state->fPreferredDownload = (!pfrom.IsInboundConn() || pfrom.HasPermission(NetPermissionFlags::NoBan)) && !pfrom.IsAddrFetchConn() && !pfrom.fClient; + m_num_preferred_download_peers += state->fPreferredDownload; + } + + // Self advertisement & GETADDR logic + if (!pfrom.IsInboundConn() && SetupAddressRelay(pfrom, *peer)) { + // For outbound peers, we try to relay our address (so that other + // nodes can try to find us more quickly, as we have no guarantee + // that an outbound peer is even aware of how to reach us) and do a + // one-time address fetch (to help populate/update our addrman). If + // we're starting up for the first time, our addrman may be pretty + // empty and no one will know who we are, so these mechanisms are + // important to help us connect to the network. + // + // We skip this for block-relay-only peers. We want to avoid + // potentially leaking addr information and we do not want to + // indicate to the peer that we will participate in addr relay. + if (fListen && !m_chainman.ActiveChainstate().IsInitialBlockDownload()) + { + CAddress addr = GetLocalAddress(&pfrom.addr, pfrom.GetLocalServices()); + FastRandomContext insecure_rand; + if (addr.IsRoutable()) + { + LogPrint(BCLog::NET, "ProcessMessages: advertising address %s\n", addr.ToString()); + PushAddress(*peer, addr, insecure_rand); + } else if (IsPeerAddrLocalGood(&pfrom)) { + // Override just the address with whatever the peer sees us as. + // Leave the port in addr as it was returned by GetLocalAddress() + // above, as this is an outbound connection and the peer cannot + // observe our listening port. + addr.SetIP(addrMe); + LogPrint(BCLog::NET, "ProcessMessages: advertising address %s\n", addr.ToString()); + PushAddress(*peer, addr, insecure_rand); + } + } + + // Get recent addresses + m_connman.PushMessage(&pfrom, CNetMsgMaker(greatest_common_version).Make(NetMsgType::GETADDR)); + peer->m_getaddr_sent = true; + // When requesting a getaddr, accept an additional MAX_ADDR_TO_SEND addresses in response + // (bypassing the MAX_ADDR_PROCESSING_TOKEN_BUCKET limit). + peer->m_addr_token_bucket += MAX_ADDR_TO_SEND; + } + + if (!pfrom.IsInboundConn()) { + // For non-inbound connections, we update the addrman to record + // connection success so that addrman will have an up-to-date + // notion of which peers are online and available. + // + // While we strive to not leak information about block-relay-only + // connections via the addrman, not moving an address to the tried + // table is also potentially detrimental because new-table entries + // are subject to eviction in the event of addrman collisions. We + // mitigate the information-leak by never calling + // AddrMan::Connected() on block-relay-only peers; see + // FinalizeNode(). + // + // This moves an address from New to Tried table in Addrman, + // resolves tried-table collisions, etc. + m_addrman.Good(pfrom.addr); + } + + std::string remoteAddr; + if (fLogIPs) + remoteAddr = ", peeraddr=" + pfrom.addr.ToString(); + + LogPrint(BCLog::NET, "receive version message: %s: version %d, blocks=%d, us=%s, txrelay=%d, peer=%d%s\n", + cleanSubVer, pfrom.nVersion, + peer->m_starting_height, addrMe.ToString(), fRelay, pfrom.GetId(), + remoteAddr); + + int64_t nTimeOffset = nTime - GetTime(); + pfrom.nTimeOffset = nTimeOffset; + if (!pfrom.IsInboundConn()) { + // Don't use timedata samples from inbound peers to make it + // harder for others to tamper with our adjusted time. + AddTimeData(pfrom.addr, nTimeOffset); + } + + // If the peer is old enough to have the old alert system, send it the final alert. + if (greatest_common_version <= 70012) { + CDataStream finalAlert(ParseHex("60010000000000000000000000ffffff7f00000000ffffff7ffeffff7f01ffffff7f00000000ffffff7f00ffffff7f002f555247454e543a20416c657274206b657920636f6d70726f6d697365642c2075706772616465207265717569726564004630440220653febd6410f470f6bae11cad19c48413becb1ac2c17f908fd0fd53bdc3abd5202206d0e9c96fe88d4a0f01ed9dedae2b6f9e00da94cad0fecaae66ecf689bf71b50"), SER_NETWORK, PROTOCOL_VERSION); + m_connman.PushMessage(&pfrom, CNetMsgMaker(greatest_common_version).Make("alert", finalAlert)); + } + + // Feeler connections exist only to verify if address is online. + if (pfrom.IsFeelerConn()) { + LogPrint(BCLog::NET, "feeler connection completed peer=%d; disconnecting\n", pfrom.GetId()); + pfrom.fDisconnect = true; + } + return; + } + + if (pfrom.nVersion == 0) { + // Must have a version message before anything else + LogPrint(BCLog::NET, "non-version message before version handshake. Message \"%s\" from peer=%d\n", SanitizeString(msg_type), pfrom.GetId()); + return; + } + + // At this point, the outgoing message serialization version can't change. + const CNetMsgMaker msgMaker(pfrom.GetCommonVersion()); + + if (msg_type == NetMsgType::VERACK) { + if (pfrom.fSuccessfullyConnected) { + LogPrint(BCLog::NET, "ignoring redundant verack message from peer=%d\n", pfrom.GetId()); + return; + } + + if (!pfrom.IsInboundConn()) { + LogPrintf("New outbound peer connected: version: %d, blocks=%d, peer=%d%s (%s)\n", + pfrom.nVersion.load(), peer->m_starting_height, + pfrom.GetId(), (fLogIPs ? strprintf(", peeraddr=%s", pfrom.addr.ToString()) : ""), + pfrom.ConnectionTypeAsString()); + } + + if (pfrom.GetCommonVersion() >= SENDHEADERS_VERSION) { + // Tell our peer we prefer to receive headers rather than inv's + // We send this to non-NODE NETWORK peers as well, because even + // non-NODE NETWORK peers can announce blocks (such as pruning + // nodes) + m_connman.PushMessage(&pfrom, msgMaker.Make(NetMsgType::SENDHEADERS)); + } + if (pfrom.GetCommonVersion() >= SHORT_IDS_BLOCKS_VERSION) { + // Tell our peer we are willing to provide version 1 or 2 cmpctblocks + // However, we do not request new block announcements using + // cmpctblock messages. + // We send this to non-NODE NETWORK peers as well, because + // they may wish to request compact blocks from us + bool fAnnounceUsingCMPCTBLOCK = false; + uint64_t nCMPCTBLOCKVersion = 2; + m_connman.PushMessage(&pfrom, msgMaker.Make(NetMsgType::SENDCMPCT, fAnnounceUsingCMPCTBLOCK, nCMPCTBLOCKVersion)); + nCMPCTBLOCKVersion = 1; + m_connman.PushMessage(&pfrom, msgMaker.Make(NetMsgType::SENDCMPCT, fAnnounceUsingCMPCTBLOCK, nCMPCTBLOCKVersion)); + } + pfrom.fSuccessfullyConnected = true; + return; + } + + if (msg_type == NetMsgType::SENDHEADERS) { + LOCK(cs_main); + State(pfrom.GetId())->fPreferHeaders = true; + return; + } + + if (msg_type == NetMsgType::SENDCMPCT) { + bool fAnnounceUsingCMPCTBLOCK = false; + uint64_t nCMPCTBLOCKVersion = 0; + vRecv >> fAnnounceUsingCMPCTBLOCK >> nCMPCTBLOCKVersion; + if (nCMPCTBLOCKVersion == 1 || nCMPCTBLOCKVersion == 2) { + LOCK(cs_main); + // fProvidesHeaderAndIDs is used to "lock in" version of compact blocks we send (fWantsCmpctWitness) + if (!State(pfrom.GetId())->fProvidesHeaderAndIDs) { + State(pfrom.GetId())->fProvidesHeaderAndIDs = true; + State(pfrom.GetId())->fWantsCmpctWitness = nCMPCTBLOCKVersion == 2; + } + if (State(pfrom.GetId())->fWantsCmpctWitness == (nCMPCTBLOCKVersion == 2)) { // ignore later version announces + State(pfrom.GetId())->fPreferHeaderAndIDs = fAnnounceUsingCMPCTBLOCK; + // save whether peer selects us as BIP152 high-bandwidth peer + // (receiving sendcmpct(1) signals high-bandwidth, sendcmpct(0) low-bandwidth) + pfrom.m_bip152_highbandwidth_from = fAnnounceUsingCMPCTBLOCK; + } + if (!State(pfrom.GetId())->fSupportsDesiredCmpctVersion) { + State(pfrom.GetId())->fSupportsDesiredCmpctVersion = (nCMPCTBLOCKVersion == 2); + } + } + return; + } + + // BIP339 defines feature negotiation of wtxidrelay, which must happen between + // VERSION and VERACK to avoid relay problems from switching after a connection is up. + if (msg_type == NetMsgType::WTXIDRELAY) { + if (pfrom.fSuccessfullyConnected) { + // Disconnect peers that send a wtxidrelay message after VERACK. + LogPrint(BCLog::NET, "wtxidrelay received after verack from peer=%d; disconnecting\n", pfrom.GetId()); + pfrom.fDisconnect = true; + return; + } + if (pfrom.GetCommonVersion() >= WTXID_RELAY_VERSION) { + if (!peer->m_wtxid_relay) { + peer->m_wtxid_relay = true; + m_wtxid_relay_peers++; + } else { + LogPrint(BCLog::NET, "ignoring duplicate wtxidrelay from peer=%d\n", pfrom.GetId()); + } + } else { + LogPrint(BCLog::NET, "ignoring wtxidrelay due to old common version=%d from peer=%d\n", pfrom.GetCommonVersion(), pfrom.GetId()); + } + return; + } + + // BIP155 defines feature negotiation of addrv2 and sendaddrv2, which must happen + // between VERSION and VERACK. + if (msg_type == NetMsgType::SENDADDRV2) { + if (pfrom.fSuccessfullyConnected) { + // Disconnect peers that send a SENDADDRV2 message after VERACK. + LogPrint(BCLog::NET, "sendaddrv2 received after verack from peer=%d; disconnecting\n", pfrom.GetId()); + pfrom.fDisconnect = true; + return; + } + peer->m_wants_addrv2 = true; + return; + } + + if (!pfrom.fSuccessfullyConnected) { + LogPrint(BCLog::NET, "Unsupported message \"%s\" prior to verack from peer=%d\n", SanitizeString(msg_type), pfrom.GetId()); + return; + } + + if (msg_type == NetMsgType::ADDR || msg_type == NetMsgType::ADDRV2) { + int stream_version = vRecv.GetVersion(); + if (msg_type == NetMsgType::ADDRV2) { + // Add ADDRV2_FORMAT to the version so that the CNetAddr and CAddress + // unserialize methods know that an address in v2 format is coming. + stream_version |= ADDRV2_FORMAT; + } + + OverrideStream<CDataStream> s(&vRecv, vRecv.GetType(), stream_version); + std::vector<CAddress> vAddr; + + s >> vAddr; + + if (!SetupAddressRelay(pfrom, *peer)) { + LogPrint(BCLog::NET, "ignoring %s message from %s peer=%d\n", msg_type, pfrom.ConnectionTypeAsString(), pfrom.GetId()); + return; + } + + if (vAddr.size() > MAX_ADDR_TO_SEND) + { + Misbehaving(pfrom.GetId(), 20, strprintf("%s message size = %u", msg_type, vAddr.size())); + return; + } + + // Store the new addresses + std::vector<CAddress> vAddrOk; + int64_t nNow = GetAdjustedTime(); + int64_t nSince = nNow - 10 * 60; + + // Update/increment addr rate limiting bucket. + const auto current_time{GetTime<std::chrono::microseconds>()}; + if (peer->m_addr_token_bucket < MAX_ADDR_PROCESSING_TOKEN_BUCKET) { + // Don't increment bucket if it's already full + const auto time_diff = std::max(current_time - peer->m_addr_token_timestamp, 0us); + const double increment = CountSecondsDouble(time_diff) * MAX_ADDR_RATE_PER_SECOND; + peer->m_addr_token_bucket = std::min<double>(peer->m_addr_token_bucket + increment, MAX_ADDR_PROCESSING_TOKEN_BUCKET); + } + peer->m_addr_token_timestamp = current_time; + + const bool rate_limited = !pfrom.HasPermission(NetPermissionFlags::Addr); + uint64_t num_proc = 0; + uint64_t num_rate_limit = 0; + Shuffle(vAddr.begin(), vAddr.end(), FastRandomContext()); + for (CAddress& addr : vAddr) + { + if (interruptMsgProc) + return; + + // Apply rate limiting. + if (peer->m_addr_token_bucket < 1.0) { + if (rate_limited) { + ++num_rate_limit; + continue; + } + } else { + peer->m_addr_token_bucket -= 1.0; + } + // 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) && !HasAllDesirableServiceFlags(addr.nServices)) + continue; + + if (addr.nTime <= 100000000 || addr.nTime > nNow + 10 * 60) + addr.nTime = nNow - 5 * 24 * 60 * 60; + AddAddressKnown(*peer, addr); + if (m_banman && (m_banman->IsDiscouraged(addr) || m_banman->IsBanned(addr))) { + // Do not process banned/discouraged addresses beyond remembering we received them + continue; + } + ++num_proc; + bool fReachable = IsReachable(addr); + if (addr.nTime > nSince && !peer->m_getaddr_sent && vAddr.size() <= 10 && addr.IsRoutable()) { + // Relay to a limited number of other nodes + RelayAddress(pfrom.GetId(), addr, fReachable); + } + // Do not store addresses outside our network + if (fReachable) + vAddrOk.push_back(addr); + } + peer->m_addr_processed += num_proc; + peer->m_addr_rate_limited += num_rate_limit; + LogPrint(BCLog::NET, "Received addr: %u addresses (%u processed, %u rate-limited) from peer=%d\n", + vAddr.size(), num_proc, num_rate_limit, pfrom.GetId()); + + m_addrman.Add(vAddrOk, pfrom.addr, 2 * 60 * 60); + if (vAddr.size() < 1000) peer->m_getaddr_sent = false; + + // AddrFetch: Require multiple addresses to avoid disconnecting on self-announcements + if (pfrom.IsAddrFetchConn() && vAddr.size() > 1) { + LogPrint(BCLog::NET, "addrfetch connection completed peer=%d; disconnecting\n", pfrom.GetId()); + pfrom.fDisconnect = true; + } + return; + } + + if (msg_type == NetMsgType::INV) { + std::vector<CInv> vInv; + vRecv >> vInv; + if (vInv.size() > MAX_INV_SZ) + { + Misbehaving(pfrom.GetId(), 20, strprintf("inv message size = %u", vInv.size())); + return; + } + + // Reject tx INVs when the -blocksonly setting is enabled, or this is a + // block-relay-only peer + bool reject_tx_invs{m_ignore_incoming_txs || (peer->m_tx_relay == nullptr)}; + + // Allow peers with relay permission to send data other than blocks in blocks only mode + if (pfrom.HasPermission(NetPermissionFlags::Relay)) { + reject_tx_invs = false; + } + + LOCK(cs_main); + + const auto current_time{GetTime<std::chrono::microseconds>()}; + uint256* best_block{nullptr}; + + for (CInv& inv : vInv) { + if (interruptMsgProc) return; + + // Ignore INVs that don't match wtxidrelay setting. + // Note that orphan parent fetching always uses MSG_TX GETDATAs regardless of the wtxidrelay setting. + // This is fine as no INV messages are involved in that process. + if (peer->m_wtxid_relay) { + if (inv.IsMsgTx()) continue; + } else { + if (inv.IsMsgWtx()) continue; + } + + if (inv.IsMsgBlk()) { + const bool fAlreadyHave = AlreadyHaveBlock(inv.hash); + LogPrint(BCLog::NET, "got inv: %s %s peer=%d\n", inv.ToString(), fAlreadyHave ? "have" : "new", pfrom.GetId()); + + UpdateBlockAvailability(pfrom.GetId(), inv.hash); + if (!fAlreadyHave && !fImporting && !fReindex && !IsBlockRequested(inv.hash)) { + // Headers-first is the primary method of announcement on + // the network. If a node fell back to sending blocks by inv, + // it's probably for a re-org. The final block hash + // provided should be the highest, so send a getheaders and + // then fetch the blocks we need to catch up. + best_block = &inv.hash; + } + } else if (inv.IsGenTxMsg()) { + if (reject_tx_invs) { + LogPrint(BCLog::NET, "transaction (%s) inv sent in violation of protocol, disconnecting peer=%d\n", inv.hash.ToString(), pfrom.GetId()); + pfrom.fDisconnect = true; + return; + } + const GenTxid gtxid = ToGenTxid(inv); + const bool fAlreadyHave = AlreadyHaveTx(gtxid); + LogPrint(BCLog::NET, "got inv: %s %s peer=%d\n", inv.ToString(), fAlreadyHave ? "have" : "new", pfrom.GetId()); + + AddKnownTx(*peer, inv.hash); + if (!fAlreadyHave && !m_chainman.ActiveChainstate().IsInitialBlockDownload()) { + AddTxAnnouncement(pfrom, gtxid, current_time); + } + } else { + LogPrint(BCLog::NET, "Unknown inv type \"%s\" received from peer=%d\n", inv.ToString(), pfrom.GetId()); + } + } + + if (best_block != nullptr) { + m_connman.PushMessage(&pfrom, msgMaker.Make(NetMsgType::GETHEADERS, m_chainman.ActiveChain().GetLocator(m_chainman.m_best_header), *best_block)); + LogPrint(BCLog::NET, "getheaders (%d) %s to peer=%d\n", m_chainman.m_best_header->nHeight, best_block->ToString(), pfrom.GetId()); + } + + return; + } + + if (msg_type == NetMsgType::GETDATA) { + std::vector<CInv> vInv; + vRecv >> vInv; + if (vInv.size() > MAX_INV_SZ) + { + Misbehaving(pfrom.GetId(), 20, strprintf("getdata message size = %u", vInv.size())); + return; + } + + LogPrint(BCLog::NET, "received getdata (%u invsz) peer=%d\n", vInv.size(), pfrom.GetId()); + + if (vInv.size() > 0) { + LogPrint(BCLog::NET, "received getdata for: %s peer=%d\n", vInv[0].ToString(), pfrom.GetId()); + } + + { + LOCK(peer->m_getdata_requests_mutex); + peer->m_getdata_requests.insert(peer->m_getdata_requests.end(), vInv.begin(), vInv.end()); + ProcessGetData(pfrom, *peer, interruptMsgProc); + } + + return; + } + + if (msg_type == NetMsgType::GETBLOCKS) { + CBlockLocator locator; + uint256 hashStop; + vRecv >> locator >> hashStop; + + if (locator.vHave.size() > MAX_LOCATOR_SZ) { + LogPrint(BCLog::NET, "getblocks locator size %lld > %d, disconnect peer=%d\n", locator.vHave.size(), MAX_LOCATOR_SZ, pfrom.GetId()); + pfrom.fDisconnect = true; + return; + } + + // We might have announced the currently-being-connected tip using a + // compact block, which resulted in the peer sending a getblocks + // request, which we would otherwise respond to without the new block. + // To avoid this situation we simply verify that we are on our best + // known chain now. This is super overkill, but we handle it better + // for getheaders requests, and there are no known nodes which support + // compact blocks but still use getblocks to request blocks. + { + std::shared_ptr<const CBlock> a_recent_block; + { + LOCK(m_most_recent_block_mutex); + a_recent_block = m_most_recent_block; + } + BlockValidationState state; + if (!m_chainman.ActiveChainstate().ActivateBestChain(state, a_recent_block)) { + LogPrint(BCLog::NET, "failed to activate chain (%s)\n", state.ToString()); + } + } + + LOCK(cs_main); + + // Find the last block the caller has in the main chain + const CBlockIndex* pindex = m_chainman.ActiveChainstate().FindForkInGlobalIndex(locator); + + // Send the rest of the chain + if (pindex) + pindex = m_chainman.ActiveChain().Next(pindex); + int nLimit = 500; + LogPrint(BCLog::NET, "getblocks %d to %s limit %d from peer=%d\n", (pindex ? pindex->nHeight : -1), hashStop.IsNull() ? "end" : hashStop.ToString(), nLimit, pfrom.GetId()); + for (; pindex; pindex = m_chainman.ActiveChain().Next(pindex)) + { + if (pindex->GetBlockHash() == hashStop) + { + LogPrint(BCLog::NET, " getblocks stopping at %d %s\n", pindex->nHeight, pindex->GetBlockHash().ToString()); + break; + } + // If pruning, don't inv blocks unless we have on disk and are likely to still have + // for some reasonable time window (1 hour) that block relay might require. + const int nPrunedBlocksLikelyToHave = MIN_BLOCKS_TO_KEEP - 3600 / m_chainparams.GetConsensus().nPowTargetSpacing; + if (fPruneMode && (!(pindex->nStatus & BLOCK_HAVE_DATA) || pindex->nHeight <= m_chainman.ActiveChain().Tip()->nHeight - nPrunedBlocksLikelyToHave)) + { + LogPrint(BCLog::NET, " getblocks stopping, pruned or too old block at %d %s\n", pindex->nHeight, pindex->GetBlockHash().ToString()); + break; + } + WITH_LOCK(peer->m_block_inv_mutex, peer->m_blocks_for_inv_relay.push_back(pindex->GetBlockHash())); + if (--nLimit <= 0) { + // When this block is requested, we'll send an inv that'll + // trigger the peer to getblocks the next batch of inventory. + LogPrint(BCLog::NET, " getblocks stopping at limit %d %s\n", pindex->nHeight, pindex->GetBlockHash().ToString()); + WITH_LOCK(peer->m_block_inv_mutex, {peer->m_continuation_block = pindex->GetBlockHash();}); + break; + } + } + return; + } + + if (msg_type == NetMsgType::GETBLOCKTXN) { + BlockTransactionsRequest req; + vRecv >> req; + + std::shared_ptr<const CBlock> recent_block; + { + LOCK(m_most_recent_block_mutex); + if (m_most_recent_block_hash == req.blockhash) + recent_block = m_most_recent_block; + // Unlock m_most_recent_block_mutex to avoid cs_main lock inversion + } + if (recent_block) { + SendBlockTransactions(pfrom, *recent_block, req); + return; + } + + { + LOCK(cs_main); + + const CBlockIndex* pindex = m_chainman.m_blockman.LookupBlockIndex(req.blockhash); + if (!pindex || !(pindex->nStatus & BLOCK_HAVE_DATA)) { + LogPrint(BCLog::NET, "Peer %d sent us a getblocktxn for a block we don't have\n", pfrom.GetId()); + return; + } + + if (pindex->nHeight >= m_chainman.ActiveChain().Height() - MAX_BLOCKTXN_DEPTH) { + CBlock block; + bool ret = ReadBlockFromDisk(block, pindex, m_chainparams.GetConsensus()); + assert(ret); + + SendBlockTransactions(pfrom, block, req); + return; + } + } + + // If an older block is requested (should never happen in practice, + // but can happen in tests) send a block response instead of a + // blocktxn response. Sending a full block response instead of a + // small blocktxn response is preferable in the case where a peer + // might maliciously send lots of getblocktxn requests to trigger + // expensive disk reads, because it will require the peer to + // actually receive all the data read from disk over the network. + LogPrint(BCLog::NET, "Peer %d sent us a getblocktxn for a block > %i deep\n", pfrom.GetId(), MAX_BLOCKTXN_DEPTH); + CInv inv; + WITH_LOCK(cs_main, inv.type = State(pfrom.GetId())->fWantsCmpctWitness ? MSG_WITNESS_BLOCK : MSG_BLOCK); + inv.hash = req.blockhash; + WITH_LOCK(peer->m_getdata_requests_mutex, peer->m_getdata_requests.push_back(inv)); + // The message processing loop will go around again (without pausing) and we'll respond then + return; + } + + if (msg_type == NetMsgType::GETHEADERS) { + CBlockLocator locator; + uint256 hashStop; + vRecv >> locator >> hashStop; + + if (locator.vHave.size() > MAX_LOCATOR_SZ) { + LogPrint(BCLog::NET, "getheaders locator size %lld > %d, disconnect peer=%d\n", locator.vHave.size(), MAX_LOCATOR_SZ, pfrom.GetId()); + pfrom.fDisconnect = true; + return; + } + + LOCK(cs_main); + if (m_chainman.ActiveChainstate().IsInitialBlockDownload() && !pfrom.HasPermission(NetPermissionFlags::Download)) { + LogPrint(BCLog::NET, "Ignoring getheaders from peer=%d because node is in initial block download\n", pfrom.GetId()); + return; + } + + CNodeState *nodestate = State(pfrom.GetId()); + const CBlockIndex* pindex = nullptr; + if (locator.IsNull()) + { + // If locator is null, return the hashStop block + pindex = m_chainman.m_blockman.LookupBlockIndex(hashStop); + if (!pindex) { + return; + } + + if (!BlockRequestAllowed(pindex)) { + 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; + } + } + else + { + // Find the last block the caller has in the main chain + pindex = m_chainman.ActiveChainstate().FindForkInGlobalIndex(locator); + if (pindex) + pindex = m_chainman.ActiveChain().Next(pindex); + } + + // we must use CBlocks, as CBlockHeaders won't include the 0x00 nTx count at the end + std::vector<CBlock> vHeaders; + int nLimit = MAX_HEADERS_RESULTS; + LogPrint(BCLog::NET, "getheaders %d to %s from peer=%d\n", (pindex ? pindex->nHeight : -1), hashStop.IsNull() ? "end" : hashStop.ToString(), pfrom.GetId()); + for (; pindex; pindex = m_chainman.ActiveChain().Next(pindex)) + { + vHeaders.push_back(pindex->GetBlockHeader()); + if (--nLimit <= 0 || pindex->GetBlockHash() == hashStop) + break; + } + // pindex can be nullptr either if we sent m_chainman.ActiveChain().Tip() OR + // if our peer has m_chainman.ActiveChain().Tip() (and thus we are sending an empty + // headers message). In both cases it's safe to update + // pindexBestHeaderSent to be our tip. + // + // It is important that we simply reset the BestHeaderSent value here, + // and not max(BestHeaderSent, newHeaderSent). We might have announced + // the currently-being-connected tip using a compact block, which + // resulted in the peer sending a headers request, which we respond to + // without the new block. By resetting the BestHeaderSent, we ensure we + // will re-announce the new block via headers (or compact blocks again) + // in the SendMessages logic. + nodestate->pindexBestHeaderSent = pindex ? pindex : m_chainman.ActiveChain().Tip(); + m_connman.PushMessage(&pfrom, msgMaker.Make(NetMsgType::HEADERS, vHeaders)); + return; + } + + if (msg_type == NetMsgType::TX) { + // Stop processing the transaction early if + // 1) We are in blocks only mode and peer has no relay permission + // 2) This peer is a block-relay-only peer + if ((m_ignore_incoming_txs && !pfrom.HasPermission(NetPermissionFlags::Relay)) || (peer->m_tx_relay == nullptr)) { + LogPrint(BCLog::NET, "transaction sent in violation of protocol peer=%d\n", pfrom.GetId()); + pfrom.fDisconnect = true; + return; + } + + // Stop processing the transaction early if we are still in IBD since we don't + // have enough information to validate it yet. Sending unsolicited transactions + // is not considered a protocol violation, so don't punish the peer. + if (m_chainman.ActiveChainstate().IsInitialBlockDownload()) return; + + CTransactionRef ptx; + vRecv >> ptx; + const CTransaction& tx = *ptx; + + const uint256& txid = ptx->GetHash(); + const uint256& wtxid = ptx->GetWitnessHash(); + + const uint256& hash = peer->m_wtxid_relay ? wtxid : txid; + AddKnownTx(*peer, hash); + if (peer->m_wtxid_relay && txid != wtxid) { + // Insert txid into m_tx_inventory_known_filter, even for + // wtxidrelay peers. This prevents re-adding of + // unconfirmed parents to the recently_announced + // filter, when a child tx is requested. See + // ProcessGetData(). + AddKnownTx(*peer, txid); + } + + LOCK2(cs_main, g_cs_orphans); + + m_txrequest.ReceivedResponse(pfrom.GetId(), txid); + if (tx.HasWitness()) m_txrequest.ReceivedResponse(pfrom.GetId(), wtxid); + + // We do the AlreadyHaveTx() check using wtxid, rather than txid - in the + // absence of witness malleation, this is strictly better, because the + // recent rejects filter may contain the wtxid but rarely contains + // the txid of a segwit transaction that has been rejected. + // In the presence of witness malleation, it's possible that by only + // doing the check with wtxid, we could overlook a transaction which + // was confirmed with a different witness, or exists in our mempool + // with a different witness, but this has limited downside: + // mempool validation does its own lookup of whether we have the txid + // already; and an adversary can already relay us old transactions + // (older than our recency filter) if trying to DoS us, without any need + // for witness malleation. + if (AlreadyHaveTx(GenTxid::Wtxid(wtxid))) { + if (pfrom.HasPermission(NetPermissionFlags::ForceRelay)) { + // Always relay transactions received from peers with forcerelay + // permission, even if they were already in the mempool, allowing + // the node to function as a gateway for nodes hidden behind it. + if (!m_mempool.exists(GenTxid::Txid(tx.GetHash()))) { + LogPrintf("Not relaying non-mempool transaction %s from forcerelay peer=%d\n", tx.GetHash().ToString(), pfrom.GetId()); + } else { + LogPrintf("Force relaying tx %s from peer=%d\n", tx.GetHash().ToString(), pfrom.GetId()); + RelayTransaction(tx.GetHash(), tx.GetWitnessHash()); + } + } + return; + } + + const MempoolAcceptResult result = m_chainman.ProcessTransaction(ptx); + const TxValidationState& state = result.m_state; + + if (result.m_result_type == MempoolAcceptResult::ResultType::VALID) { + // As this version of the transaction was acceptable, we can forget about any + // requests for it. + m_txrequest.ForgetTxHash(tx.GetHash()); + m_txrequest.ForgetTxHash(tx.GetWitnessHash()); + RelayTransaction(tx.GetHash(), tx.GetWitnessHash()); + m_orphanage.AddChildrenToWorkSet(tx, peer->m_orphan_work_set); + + pfrom.m_last_tx_time = GetTime<std::chrono::seconds>(); + + LogPrint(BCLog::MEMPOOL, "AcceptToMemoryPool: peer=%d: accepted %s (poolsz %u txn, %u kB)\n", + pfrom.GetId(), + tx.GetHash().ToString(), + m_mempool.size(), m_mempool.DynamicMemoryUsage() / 1000); + + for (const CTransactionRef& removedTx : result.m_replaced_transactions.value()) { + AddToCompactExtraTransactions(removedTx); + } + + // Recursively process any orphan transactions that depended on this one + ProcessOrphanTx(peer->m_orphan_work_set); + } + else if (state.GetResult() == TxValidationResult::TX_MISSING_INPUTS) + { + bool fRejectedParents = false; // It may be the case that the orphans parents have all been rejected + + // Deduplicate parent txids, so that we don't have to loop over + // the same parent txid more than once down below. + std::vector<uint256> unique_parents; + unique_parents.reserve(tx.vin.size()); + for (const CTxIn& txin : tx.vin) { + // We start with all parents, and then remove duplicates below. + unique_parents.push_back(txin.prevout.hash); + } + std::sort(unique_parents.begin(), unique_parents.end()); + unique_parents.erase(std::unique(unique_parents.begin(), unique_parents.end()), unique_parents.end()); + for (const uint256& parent_txid : unique_parents) { + if (m_recent_rejects.contains(parent_txid)) { + fRejectedParents = true; + break; + } + } + if (!fRejectedParents) { + const auto current_time{GetTime<std::chrono::microseconds>()}; + + for (const uint256& parent_txid : unique_parents) { + // Here, we only have the txid (and not wtxid) of the + // inputs, so we only request in txid mode, even for + // wtxidrelay peers. + // Eventually we should replace this with an improved + // protocol for getting all unconfirmed parents. + const auto gtxid{GenTxid::Txid(parent_txid)}; + AddKnownTx(*peer, parent_txid); + if (!AlreadyHaveTx(gtxid)) AddTxAnnouncement(pfrom, gtxid, current_time); + } + + if (m_orphanage.AddTx(ptx, pfrom.GetId())) { + AddToCompactExtraTransactions(ptx); + } + + // Once added to the orphan pool, a tx is considered AlreadyHave, and we shouldn't request it anymore. + m_txrequest.ForgetTxHash(tx.GetHash()); + m_txrequest.ForgetTxHash(tx.GetWitnessHash()); + + // DoS prevention: do not allow m_orphanage to grow unbounded (see CVE-2012-3789) + unsigned int nMaxOrphanTx = (unsigned int)std::max((int64_t)0, gArgs.GetIntArg("-maxorphantx", DEFAULT_MAX_ORPHAN_TRANSACTIONS)); + unsigned int nEvicted = m_orphanage.LimitOrphans(nMaxOrphanTx); + if (nEvicted > 0) { + LogPrint(BCLog::MEMPOOL, "orphanage overflow, removed %u tx\n", nEvicted); + } + } else { + LogPrint(BCLog::MEMPOOL, "not keeping orphan with rejected parents %s\n",tx.GetHash().ToString()); + // We will continue to reject this tx since it has rejected + // parents so avoid re-requesting it from other peers. + // Here we add both the txid and the wtxid, as we know that + // regardless of what witness is provided, we will not accept + // this, so we don't need to allow for redownload of this txid + // from any of our non-wtxidrelay peers. + m_recent_rejects.insert(tx.GetHash()); + m_recent_rejects.insert(tx.GetWitnessHash()); + m_txrequest.ForgetTxHash(tx.GetHash()); + m_txrequest.ForgetTxHash(tx.GetWitnessHash()); + } + } else { + if (state.GetResult() != TxValidationResult::TX_WITNESS_STRIPPED) { + // We can add the wtxid of this transaction to our reject filter. + // Do not add txids of witness transactions or witness-stripped + // transactions to the filter, as they can have been malleated; + // adding such txids to the reject filter would potentially + // interfere with relay of valid transactions from peers that + // do not support wtxid-based relay. See + // https://github.com/bitcoin/bitcoin/issues/8279 for details. + // We can remove this restriction (and always add wtxids to + // the filter even for witness stripped transactions) once + // wtxid-based relay is broadly deployed. + // See also comments in https://github.com/bitcoin/bitcoin/pull/18044#discussion_r443419034 + // for concerns around weakening security of unupgraded nodes + // if we start doing this too early. + m_recent_rejects.insert(tx.GetWitnessHash()); + m_txrequest.ForgetTxHash(tx.GetWitnessHash()); + // If the transaction failed for TX_INPUTS_NOT_STANDARD, + // then we know that the witness was irrelevant to the policy + // failure, since this check depends only on the txid + // (the scriptPubKey being spent is covered by the txid). + // Add the txid to the reject filter to prevent repeated + // processing of this transaction in the event that child + // transactions are later received (resulting in + // parent-fetching by txid via the orphan-handling logic). + if (state.GetResult() == TxValidationResult::TX_INPUTS_NOT_STANDARD && tx.GetWitnessHash() != tx.GetHash()) { + m_recent_rejects.insert(tx.GetHash()); + m_txrequest.ForgetTxHash(tx.GetHash()); + } + if (RecursiveDynamicUsage(*ptx) < 100000) { + AddToCompactExtraTransactions(ptx); + } + } + } + + // If a tx has been detected by m_recent_rejects, we will have reached + // this point and the tx will have been ignored. Because we haven't + // submitted the tx to our mempool, we won't have computed a DoS + // score for it or determined exactly why we consider it invalid. + // + // This means we won't penalize any peer subsequently relaying a DoSy + // tx (even if we penalized the first peer who gave it to us) because + // we have to account for m_recent_rejects showing false positives. In + // other words, we shouldn't penalize a peer if we aren't *sure* they + // submitted a DoSy tx. + // + // Note that m_recent_rejects doesn't just record DoSy or invalid + // transactions, but any tx not accepted by the mempool, which may be + // due to node policy (vs. consensus). So we can't blanket penalize a + // peer simply for relaying a tx that our m_recent_rejects has caught, + // regardless of false positives. + + if (state.IsInvalid()) { + LogPrint(BCLog::MEMPOOLREJ, "%s from peer=%d was not accepted: %s\n", tx.GetHash().ToString(), + pfrom.GetId(), + state.ToString()); + MaybePunishNodeForTx(pfrom.GetId(), state); + } + return; + } + + if (msg_type == NetMsgType::CMPCTBLOCK) + { + // Ignore cmpctblock received while importing + if (fImporting || fReindex) { + LogPrint(BCLog::NET, "Unexpected cmpctblock message received from peer %d\n", pfrom.GetId()); + return; + } + + CBlockHeaderAndShortTxIDs cmpctblock; + vRecv >> cmpctblock; + + bool received_new_header = false; + + { + LOCK(cs_main); + + if (!m_chainman.m_blockman.LookupBlockIndex(cmpctblock.header.hashPrevBlock)) { + // Doesn't connect (or is genesis), instead of DoSing in AcceptBlockHeader, request deeper headers + if (!m_chainman.ActiveChainstate().IsInitialBlockDownload()) + m_connman.PushMessage(&pfrom, msgMaker.Make(NetMsgType::GETHEADERS, m_chainman.ActiveChain().GetLocator(m_chainman.m_best_header), uint256())); + return; + } + + if (!m_chainman.m_blockman.LookupBlockIndex(cmpctblock.header.GetHash())) { + received_new_header = true; + } + } + + const CBlockIndex *pindex = nullptr; + BlockValidationState state; + if (!m_chainman.ProcessNewBlockHeaders({cmpctblock.header}, state, m_chainparams, &pindex)) { + if (state.IsInvalid()) { + MaybePunishNodeForBlock(pfrom.GetId(), state, /*via_compact_block=*/true, "invalid header via cmpctblock"); + return; + } + } + + // When we succeed in decoding a block's txids from a cmpctblock + // message we typically jump to the BLOCKTXN handling code, with a + // dummy (empty) BLOCKTXN message, to re-use the logic there in + // completing processing of the putative block (without cs_main). + bool fProcessBLOCKTXN = false; + CDataStream blockTxnMsg(SER_NETWORK, PROTOCOL_VERSION); + + // If we end up treating this as a plain headers message, call that as well + // without cs_main. + bool fRevertToHeaderProcessing = false; + + // Keep a CBlock for "optimistic" compactblock reconstructions (see + // below) + std::shared_ptr<CBlock> pblock = std::make_shared<CBlock>(); + bool fBlockReconstructed = false; + + { + LOCK2(cs_main, g_cs_orphans); + // If AcceptBlockHeader returned true, it set pindex + 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 > m_chainman.ActiveChain().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(); + + if (pindex->nStatus & BLOCK_HAVE_DATA) // Nothing to do here + return; + + if (pindex->nChainWork <= m_chainman.ActiveChain().Tip()->nChainWork || // We know something better + pindex->nTx != 0) { // We had this block at some point, but pruned it + if (fAlreadyInFlight) { + // We requested this block for some reason, but our mempool will probably be useless + // so we just grab the block via normal getdata + std::vector<CInv> vInv(1); + vInv[0] = CInv(MSG_BLOCK | GetFetchFlags(pfrom), cmpctblock.header.GetHash()); + m_connman.PushMessage(&pfrom, msgMaker.Make(NetMsgType::GETDATA, vInv)); + } + return; + } + + // If we're not close to tip yet, give up and let parallel block fetch work its magic + if (!fAlreadyInFlight && !CanDirectFetch()) { + return; + } + + if (DeploymentActiveAt(*pindex, m_chainparams.GetConsensus(), Consensus::DEPLOYMENT_SEGWIT) && !nodestate->fSupportsDesiredCmpctVersion) { + // Don't bother trying to process compact blocks from v1 peers + // after segwit activates. + return; + } + + // We want to be a bit conservative just to be extra careful about DoS + // possibilities in compact block processing... + if (pindex->nHeight <= m_chainman.ActiveChain().Height() + 2) { + if ((!fAlreadyInFlight && nodestate->nBlocksInFlight < MAX_BLOCKS_IN_TRANSIT_PER_PEER) || + (fAlreadyInFlight && blockInFlightIt->second.first == pfrom.GetId())) { + std::list<QueuedBlock>::iterator* queuedBlockIt = nullptr; + if (!BlockRequested(pfrom.GetId(), *pindex, &queuedBlockIt)) { + if (!(*queuedBlockIt)->partialBlock) + (*queuedBlockIt)->partialBlock.reset(new PartiallyDownloadedBlock(&m_mempool)); + else { + // The block was already in flight using compact blocks from the same peer + LogPrint(BCLog::NET, "Peer sent us compact block we were already syncing!\n"); + return; + } + } + + PartiallyDownloadedBlock& partialBlock = *(*queuedBlockIt)->partialBlock; + ReadStatus status = partialBlock.InitData(cmpctblock, vExtraTxnForCompact); + if (status == READ_STATUS_INVALID) { + RemoveBlockRequest(pindex->GetBlockHash()); // Reset in-flight state in case Misbehaving does not result in a disconnect + Misbehaving(pfrom.GetId(), 100, "invalid compact block"); + return; + } else if (status == READ_STATUS_FAILED) { + // 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()); + m_connman.PushMessage(&pfrom, msgMaker.Make(NetMsgType::GETDATA, vInv)); + return; + } + + BlockTransactionsRequest req; + for (size_t i = 0; i < cmpctblock.BlockTxCount(); i++) { + if (!partialBlock.IsTxAvailable(i)) + req.indexes.push_back(i); + } + if (req.indexes.empty()) { + // Dirty hack to jump to BLOCKTXN code (TODO: move message handling into their own functions) + BlockTransactions txn; + txn.blockhash = cmpctblock.header.GetHash(); + blockTxnMsg << txn; + fProcessBLOCKTXN = true; + } else { + req.blockhash = pindex->GetBlockHash(); + m_connman.PushMessage(&pfrom, msgMaker.Make(NetMsgType::GETBLOCKTXN, req)); + } + } else { + // This block is either already in flight from a different + // peer, or this peer has too many blocks outstanding to + // download from. + // Optimistically try to reconstruct anyway since we might be + // able to without any round trips. + PartiallyDownloadedBlock tempBlock(&m_mempool); + ReadStatus status = tempBlock.InitData(cmpctblock, vExtraTxnForCompact); + if (status != READ_STATUS_OK) { + // TODO: don't ignore failures + return; + } + std::vector<CTransactionRef> dummy; + status = tempBlock.FillBlock(*pblock, dummy); + if (status == READ_STATUS_OK) { + fBlockReconstructed = true; + } + } + } else { + if (fAlreadyInFlight) { + // We requested this block, but its far into the future, so our + // mempool will probably be useless - request the block normally + std::vector<CInv> vInv(1); + vInv[0] = CInv(MSG_BLOCK | GetFetchFlags(pfrom), cmpctblock.header.GetHash()); + m_connman.PushMessage(&pfrom, msgMaker.Make(NetMsgType::GETDATA, vInv)); + return; + } else { + // If this was an announce-cmpctblock, we want the same treatment as a header message + fRevertToHeaderProcessing = true; + } + } + } // cs_main + + if (fProcessBLOCKTXN) { + return ProcessMessage(pfrom, NetMsgType::BLOCKTXN, blockTxnMsg, time_received, 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 disconnected/discouraged. + return ProcessHeadersMessage(pfrom, *peer, {cmpctblock.header}, /*via_compact_block=*/true); + } + + if (fBlockReconstructed) { + // If we got here, we were able to optimistically reconstruct a + // block that is in flight from some other peer. + { + LOCK(cs_main); + mapBlockSource.emplace(pblock->GetHash(), std::make_pair(pfrom.GetId(), false)); + } + // Setting force_processing 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. + ProcessBlock(pfrom, pblock, /*force_processing=*/true); + LOCK(cs_main); // hold cs_main for CBlockIndex::IsValid() + if (pindex->IsValid(BLOCK_VALID_TRANSACTIONS)) { + // Clear download state for this block, which is in + // process from some other peer. We do this after calling + // ProcessNewBlock so that a malleated cmpctblock announcement + // can't be used to interfere with block relay. + RemoveBlockRequest(pblock->GetHash()); + } + } + return; + } + + if (msg_type == NetMsgType::BLOCKTXN) + { + // Ignore blocktxn received while importing + if (fImporting || fReindex) { + LogPrint(BCLog::NET, "Unexpected blocktxn message received from peer %d\n", pfrom.GetId()); + return; + } + + BlockTransactions resp; + vRecv >> resp; + + std::shared_ptr<CBlock> pblock = std::make_shared<CBlock>(); + bool fBlockRead = false; + { + LOCK(cs_main); + + std::map<uint256, std::pair<NodeId, std::list<QueuedBlock>::iterator> >::iterator it = mapBlocksInFlight.find(resp.blockhash); + if (it == mapBlocksInFlight.end() || !it->second.second->partialBlock || + it->second.first != pfrom.GetId()) { + LogPrint(BCLog::NET, "Peer %d sent us block transactions for block we weren't expecting\n", pfrom.GetId()); + return; + } + + PartiallyDownloadedBlock& partialBlock = *it->second.second->partialBlock; + ReadStatus status = partialBlock.FillBlock(*pblock, resp.txn); + if (status == READ_STATUS_INVALID) { + RemoveBlockRequest(resp.blockhash); // Reset in-flight state in case Misbehaving does not result in a disconnect + Misbehaving(pfrom.GetId(), 100, "invalid compact block/non-matching block transactions"); + return; + } else if (status == READ_STATUS_FAILED) { + // Might have collided, fall back to getdata now :( + std::vector<CInv> invs; + invs.push_back(CInv(MSG_BLOCK | GetFetchFlags(pfrom), resp.blockhash)); + m_connman.PushMessage(&pfrom, msgMaker.Make(NetMsgType::GETDATA, invs)); + } else { + // Block is either okay, or possibly we received + // READ_STATUS_CHECKBLOCK_FAILED. + // Note that CheckBlock can only fail for one of a few reasons: + // 1. bad-proof-of-work (impossible here, because we've already + // accepted the header) + // 2. merkleroot doesn't match the transactions given (already + // caught in FillBlock with READ_STATUS_FAILED, so + // impossible here) + // 3. the block is otherwise invalid (eg invalid coinbase, + // block is too big, too many legacy sigops, etc). + // So if CheckBlock failed, #3 is the only possibility. + // Under BIP 152, we don't discourage the peer unless proof of work is + // invalid (we don't require all the stateless checks to have + // been run). This is handled below, so just treat this as + // though the block was successfully read, and rely on the + // handling in ProcessNewBlock to ensure the block index is + // updated, etc. + RemoveBlockRequest(resp.blockhash); // it is now an empty pointer + fBlockRead = true; + // mapBlockSource is used for potentially punishing peers and + // updating which peers send us compact blocks, so the race + // between here and cs_main in ProcessNewBlock is fine. + // BIP 152 permits peers to relay compact blocks after validating + // the header only; we should not punish peers if the block turns + // out to be invalid. + mapBlockSource.emplace(resp.blockhash, std::make_pair(pfrom.GetId(), false)); + } + } // Don't hold cs_main when we call into ProcessNewBlock + if (fBlockRead) { + // 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) + // 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. + ProcessBlock(pfrom, pblock, /*force_processing=*/true); + } + return; + } + + if (msg_type == NetMsgType::HEADERS) + { + // Ignore headers received while importing + if (fImporting || fReindex) { + LogPrint(BCLog::NET, "Unexpected headers message received from peer %d\n", pfrom.GetId()); + return; + } + + std::vector<CBlockHeader> headers; + + // Bypass the normal CBlock deserialization, as we don't want to risk deserializing 2000 full blocks. + unsigned int nCount = ReadCompactSize(vRecv); + if (nCount > MAX_HEADERS_RESULTS) { + Misbehaving(pfrom.GetId(), 20, strprintf("headers message size = %u", nCount)); + return; + } + headers.resize(nCount); + for (unsigned int n = 0; n < nCount; n++) { + vRecv >> headers[n]; + ReadCompactSize(vRecv); // ignore tx count; assume it is 0. + } + + return ProcessHeadersMessage(pfrom, *peer, headers, /*via_compact_block=*/false); + } + + if (msg_type == NetMsgType::BLOCK) + { + // Ignore block received while importing + if (fImporting || fReindex) { + LogPrint(BCLog::NET, "Unexpected block message received from peer %d\n", pfrom.GetId()); + return; + } + + std::shared_ptr<CBlock> pblock = std::make_shared<CBlock>(); + vRecv >> *pblock; + + LogPrint(BCLog::NET, "received block %s peer=%d\n", pblock->GetHash().ToString(), pfrom.GetId()); + + bool forceProcessing = false; + const uint256 hash(pblock->GetHash()); + { + LOCK(cs_main); + // Always process the block if we requested it, since we may + // need it even when it's not a candidate for a new best tip. + forceProcessing = IsBlockRequested(hash); + RemoveBlockRequest(hash); + // mapBlockSource is only used for punishing peers and setting + // which peers send us compact blocks, so the race between here and + // cs_main in ProcessNewBlock is fine. + mapBlockSource.emplace(hash, std::make_pair(pfrom.GetId(), true)); + } + ProcessBlock(pfrom, pblock, forceProcessing); + return; + } + + if (msg_type == NetMsgType::GETADDR) { + // This asymmetric behavior for inbound and outbound connections was introduced + // to prevent a fingerprinting attack: an attacker can send specific fake addresses + // to users' AddrMan and later request them by sending getaddr messages. + // Making nodes which are behind NAT and can only make outgoing connections ignore + // the getaddr message mitigates the attack. + if (!pfrom.IsInboundConn()) { + LogPrint(BCLog::NET, "Ignoring \"getaddr\" from %s connection. peer=%d\n", pfrom.ConnectionTypeAsString(), pfrom.GetId()); + return; + } + + // Since this must be an inbound connection, SetupAddressRelay will + // never fail. + Assume(SetupAddressRelay(pfrom, *peer)); + + // Only send one GetAddr response per connection to reduce resource waste + // and discourage addr stamping of INV announcements. + if (peer->m_getaddr_recvd) { + LogPrint(BCLog::NET, "Ignoring repeated \"getaddr\". peer=%d\n", pfrom.GetId()); + return; + } + peer->m_getaddr_recvd = true; + + peer->m_addrs_to_send.clear(); + std::vector<CAddress> vAddr; + if (pfrom.HasPermission(NetPermissionFlags::Addr)) { + vAddr = m_connman.GetAddresses(MAX_ADDR_TO_SEND, MAX_PCT_ADDR_TO_SEND, /*network=*/std::nullopt); + } else { + vAddr = m_connman.GetAddresses(pfrom, MAX_ADDR_TO_SEND, MAX_PCT_ADDR_TO_SEND); + } + FastRandomContext insecure_rand; + for (const CAddress &addr : vAddr) { + PushAddress(*peer, addr, insecure_rand); + } + return; + } + + if (msg_type == NetMsgType::MEMPOOL) { + if (!(pfrom.GetLocalServices() & NODE_BLOOM) && !pfrom.HasPermission(NetPermissionFlags::Mempool)) + { + if (!pfrom.HasPermission(NetPermissionFlags::NoBan)) + { + LogPrint(BCLog::NET, "mempool request with bloom filters disabled, disconnect peer=%d\n", pfrom.GetId()); + pfrom.fDisconnect = true; + } + return; + } + + if (m_connman.OutboundTargetReached(false) && !pfrom.HasPermission(NetPermissionFlags::Mempool)) + { + if (!pfrom.HasPermission(NetPermissionFlags::NoBan)) + { + LogPrint(BCLog::NET, "mempool request with bandwidth limit reached, disconnect peer=%d\n", pfrom.GetId()); + pfrom.fDisconnect = true; + } + return; + } + + if (peer->m_tx_relay != nullptr) { + LOCK(peer->m_tx_relay->m_tx_inventory_mutex); + peer->m_tx_relay->m_send_mempool = true; + } + return; + } + + if (msg_type == NetMsgType::PING) { + if (pfrom.GetCommonVersion() > BIP0031_VERSION) { + uint64_t nonce = 0; + vRecv >> nonce; + // Echo the message back with the nonce. This allows for two useful features: + // + // 1) A remote node can quickly check if the connection is operational + // 2) Remote nodes can measure the latency of the network thread. If this node + // is overloaded it won't respond to pings quickly and the remote node can + // avoid sending us more work, like chain download requests. + // + // The nonce stops the remote getting confused between different pings: without + // 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. + m_connman.PushMessage(&pfrom, msgMaker.Make(NetMsgType::PONG, nonce)); + } + return; + } + + if (msg_type == NetMsgType::PONG) { + const auto ping_end = time_received; + uint64_t nonce = 0; + size_t nAvail = vRecv.in_avail(); + bool bPingFinished = false; + std::string sProblem; + + if (nAvail >= sizeof(nonce)) { + vRecv >> nonce; + + // Only process pong message if there is an outstanding ping (old ping without nonce should never pong) + if (peer->m_ping_nonce_sent != 0) { + if (nonce == peer->m_ping_nonce_sent) { + // Matching pong received, this ping is no longer outstanding + bPingFinished = true; + const auto ping_time = ping_end - peer->m_ping_start.load(); + if (ping_time.count() >= 0) { + // Let connman know about this successful ping-pong + pfrom.PongReceived(ping_time); + } else { + // This should never happen + sProblem = "Timing mishap"; + } + } else { + // Nonce mismatches are normal when pings are overlapping + sProblem = "Nonce mismatch"; + if (nonce == 0) { + // This is most likely a bug in another implementation somewhere; cancel this ping + bPingFinished = true; + sProblem = "Nonce zero"; + } + } + } else { + sProblem = "Unsolicited pong without ping"; + } + } else { + // This is most likely a bug in another implementation somewhere; cancel this ping + bPingFinished = true; + sProblem = "Short payload"; + } + + if (!(sProblem.empty())) { + LogPrint(BCLog::NET, "pong peer=%d: %s, %x expected, %x received, %u bytes\n", + pfrom.GetId(), + sProblem, + peer->m_ping_nonce_sent, + nonce, + nAvail); + } + if (bPingFinished) { + peer->m_ping_nonce_sent = 0; + } + return; + } + + if (msg_type == NetMsgType::FILTERLOAD) { + if (!(pfrom.GetLocalServices() & NODE_BLOOM)) { + LogPrint(BCLog::NET, "filterload received despite not offering bloom services from peer=%d; disconnecting\n", pfrom.GetId()); + pfrom.fDisconnect = true; + return; + } + CBloomFilter filter; + vRecv >> filter; + + if (!filter.IsWithinSizeConstraints()) + { + // There is no excuse for sending a too-large filter + Misbehaving(pfrom.GetId(), 100, "too-large bloom filter"); + } + else if (peer->m_tx_relay != nullptr) + { + { + LOCK(peer->m_tx_relay->m_bloom_filter_mutex); + peer->m_tx_relay->m_bloom_filter.reset(new CBloomFilter(filter)); + peer->m_tx_relay->m_relay_txs = true; + } + pfrom.m_bloom_filter_loaded = true; + pfrom.m_relays_txs = true; + } + return; + } + + if (msg_type == NetMsgType::FILTERADD) { + if (!(pfrom.GetLocalServices() & NODE_BLOOM)) { + LogPrint(BCLog::NET, "filteradd received despite not offering bloom services from peer=%d; disconnecting\n", pfrom.GetId()); + pfrom.fDisconnect = true; + return; + } + std::vector<unsigned char> vData; + vRecv >> vData; + + // Nodes must NEVER send a data item > 520 bytes (the max size for a script data object, + // and thus, the maximum size any matched object can have) in a filteradd message + bool bad = false; + if (vData.size() > MAX_SCRIPT_ELEMENT_SIZE) { + bad = true; + } else if (peer->m_tx_relay != nullptr) { + LOCK(peer->m_tx_relay->m_bloom_filter_mutex); + if (peer->m_tx_relay->m_bloom_filter) { + peer->m_tx_relay->m_bloom_filter->insert(vData); + } else { + bad = true; + } + } + if (bad) { + Misbehaving(pfrom.GetId(), 100, "bad filteradd message"); + } + return; + } + + if (msg_type == NetMsgType::FILTERCLEAR) { + if (!(pfrom.GetLocalServices() & NODE_BLOOM)) { + LogPrint(BCLog::NET, "filterclear received despite not offering bloom services from peer=%d; disconnecting\n", pfrom.GetId()); + pfrom.fDisconnect = true; + return; + } + if (peer->m_tx_relay == nullptr) { + return; + } + + { + LOCK(peer->m_tx_relay->m_bloom_filter_mutex); + peer->m_tx_relay->m_bloom_filter = nullptr; + peer->m_tx_relay->m_relay_txs = true; + } + pfrom.m_bloom_filter_loaded = false; + pfrom.m_relays_txs = true; + return; + } + + if (msg_type == NetMsgType::FEEFILTER) { + CAmount newFeeFilter = 0; + vRecv >> newFeeFilter; + if (MoneyRange(newFeeFilter)) { + if (peer->m_tx_relay != nullptr) { + peer->m_tx_relay->m_fee_filter_received = newFeeFilter; + } + LogPrint(BCLog::NET, "received: feefilter of %s from peer=%d\n", CFeeRate(newFeeFilter).ToString(), pfrom.GetId()); + } + return; + } + + if (msg_type == NetMsgType::GETCFILTERS) { + ProcessGetCFilters(pfrom, vRecv); + return; + } + + if (msg_type == NetMsgType::GETCFHEADERS) { + ProcessGetCFHeaders(pfrom, vRecv); + return; + } + + if (msg_type == NetMsgType::GETCFCHECKPT) { + ProcessGetCFCheckPt(pfrom, vRecv); + return; + } + + if (msg_type == NetMsgType::NOTFOUND) { + std::vector<CInv> vInv; + vRecv >> vInv; + 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 tx we requested, mark the announcement for it as + // completed in TxRequestTracker. + m_txrequest.ReceivedResponse(pfrom.GetId(), inv.hash); + } + } + } + return; + } + + // Ignore unknown commands for extensibility + LogPrint(BCLog::NET, "Unknown command \"%s\" from peer=%d\n", SanitizeString(msg_type), pfrom.GetId()); + return; +} + +bool PeerManagerImpl::MaybeDiscourageAndDisconnect(CNode& pnode, Peer& peer) +{ + { + LOCK(peer.m_misbehavior_mutex); + + // There's nothing to do if the m_should_discourage flag isn't set + if (!peer.m_should_discourage) return false; + + peer.m_should_discourage = false; + } // peer.m_misbehavior_mutex + + if (pnode.HasPermission(NetPermissionFlags::NoBan)) { + // We never disconnect or discourage peers for bad behavior if they have NetPermissionFlags::NoBan permission + LogPrintf("Warning: not punishing noban peer %d!\n", peer.m_id); + return false; + } + + if (pnode.IsManualConn()) { + // We never disconnect or discourage manual peers for bad behavior + LogPrintf("Warning: not punishing manually connected peer %d!\n", peer.m_id); + return false; + } + + if (pnode.addr.IsLocal()) { + // We disconnect local peers for bad behavior but don't discourage (since that would discourage + // all peers on the same local address) + LogPrint(BCLog::NET, "Warning: disconnecting but not discouraging %s peer %d!\n", + pnode.m_inbound_onion ? "inbound onion" : "local", peer.m_id); + pnode.fDisconnect = true; + return true; + } + + // Normal case: Disconnect the peer and discourage all nodes sharing the address + LogPrint(BCLog::NET, "Disconnecting and discouraging peer %d!\n", peer.m_id); + if (m_banman) m_banman->Discourage(pnode.addr); + m_connman.DisconnectNode(pnode.addr); + return true; +} + +bool PeerManagerImpl::ProcessMessages(CNode* pfrom, std::atomic<bool>& interruptMsgProc) +{ + bool fMoreWork = false; + + PeerRef peer = GetPeerRef(pfrom->GetId()); + if (peer == nullptr) return false; + + { + LOCK(peer->m_getdata_requests_mutex); + if (!peer->m_getdata_requests.empty()) { + ProcessGetData(*pfrom, *peer, interruptMsgProc); + } + } + + { + LOCK2(cs_main, g_cs_orphans); + if (!peer->m_orphan_work_set.empty()) { + ProcessOrphanTx(peer->m_orphan_work_set); + } + } + + if (pfrom->fDisconnect) + return false; + + // this maintains the order of responses + // and prevents m_getdata_requests to grow unbounded + { + LOCK(peer->m_getdata_requests_mutex); + if (!peer->m_getdata_requests.empty()) return true; + } + + { + LOCK(g_cs_orphans); + if (!peer->m_orphan_work_set.empty()) return true; + } + + // Don't bother if send buffer is too full to respond anyway + if (pfrom->fPauseSend) return false; + + std::list<CNetMessage> msgs; + { + LOCK(pfrom->cs_vProcessMsg); + if (pfrom->vProcessMsg.empty()) return false; + // Just take one message + msgs.splice(msgs.begin(), pfrom->vProcessMsg, pfrom->vProcessMsg.begin()); + pfrom->nProcessQueueSize -= msgs.front().m_raw_message_size; + pfrom->fPauseRecv = pfrom->nProcessQueueSize > m_connman.GetReceiveFloodSize(); + fMoreWork = !pfrom->vProcessMsg.empty(); + } + CNetMessage& msg(msgs.front()); + + TRACE6(net, inbound_message, + pfrom->GetId(), + pfrom->m_addr_name.c_str(), + pfrom->ConnectionTypeAsString().c_str(), + msg.m_type.c_str(), + msg.m_recv.size(), + msg.m_recv.data() + ); + + if (gArgs.GetBoolArg("-capturemessages", false)) { + CaptureMessage(pfrom->addr, msg.m_type, MakeUCharSpan(msg.m_recv), /*is_incoming=*/true); + } + + msg.SetVersion(pfrom->GetCommonVersion()); + + try { + ProcessMessage(*pfrom, msg.m_type, msg.m_recv, msg.m_time, interruptMsgProc); + if (interruptMsgProc) return false; + { + LOCK(peer->m_getdata_requests_mutex); + if (!peer->m_getdata_requests.empty()) fMoreWork = true; + } + } catch (const std::exception& e) { + LogPrint(BCLog::NET, "%s(%s, %u bytes): Exception '%s' (%s) caught\n", __func__, SanitizeString(msg.m_type), msg.m_message_size, e.what(), typeid(e).name()); + } catch (...) { + LogPrint(BCLog::NET, "%s(%s, %u bytes): Unknown exception caught\n", __func__, SanitizeString(msg.m_type), msg.m_message_size); + } + + return fMoreWork; +} + +void PeerManagerImpl::ConsiderEviction(CNode& pto, std::chrono::seconds time_in_seconds) +{ + AssertLockHeld(cs_main); + + CNodeState &state = *State(pto.GetId()); + const CNetMsgMaker msgMaker(pto.GetCommonVersion()); + + if (!state.m_chain_sync.m_protect && pto.IsOutboundOrBlockRelayConn() && 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 >= m_chainman.ActiveChain().Tip()->nChainWork) { + if (state.m_chain_sync.m_timeout != 0s) { + state.m_chain_sync.m_timeout = 0s; + state.m_chain_sync.m_work_header = nullptr; + state.m_chain_sync.m_sent_getheaders = false; + } + } else if (state.m_chain_sync.m_timeout == 0s || (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 = m_chainman.ActiveChain().Tip(); + state.m_chain_sync.m_sent_getheaders = false; + } else if (state.m_chain_sync.m_timeout > 0s && 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()); + m_connman.PushMessage(&pto, msgMaker.Make(NetMsgType::GETHEADERS, m_chainman.ActiveChain().GetLocator(state.m_chain_sync.m_work_header->pprev), uint256())); + state.m_chain_sync.m_sent_getheaders = true; + constexpr auto HEADERS_RESPONSE_TIME{2min}; + // 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 PeerManagerImpl::EvictExtraOutboundPeers(std::chrono::seconds now) +{ + // If we have any extra block-relay-only peers, disconnect the youngest unless + // it's given us a block -- in which case, compare with the second-youngest, and + // out of those two, disconnect the peer who least recently gave us a block. + // The youngest block-relay-only peer would be the extra peer we connected + // to temporarily in order to sync our tip; see net.cpp. + // Note that we use higher nodeid as a measure for most recent connection. + if (m_connman.GetExtraBlockRelayCount() > 0) { + std::pair<NodeId, std::chrono::seconds> youngest_peer{-1, 0}, next_youngest_peer{-1, 0}; + + m_connman.ForEachNode([&](CNode* pnode) { + if (!pnode->IsBlockOnlyConn() || pnode->fDisconnect) return; + if (pnode->GetId() > youngest_peer.first) { + next_youngest_peer = youngest_peer; + youngest_peer.first = pnode->GetId(); + youngest_peer.second = pnode->m_last_block_time; + } + }); + NodeId to_disconnect = youngest_peer.first; + if (youngest_peer.second > next_youngest_peer.second) { + // Our newest block-relay-only peer gave us a block more recently; + // disconnect our second youngest. + to_disconnect = next_youngest_peer.first; + } + m_connman.ForNode(to_disconnect, [&](CNode* pnode) EXCLUSIVE_LOCKS_REQUIRED(::cs_main) { + AssertLockHeld(::cs_main); + // Make sure we're not getting a block right now, and that + // we've been connected long enough for this eviction to happen + // at all. + // Note that we only request blocks from a peer if we learn of a + // valid headers chain with at least as much work as our tip. + CNodeState *node_state = State(pnode->GetId()); + if (node_state == nullptr || + (now - pnode->m_connected >= MINIMUM_CONNECT_TIME && node_state->nBlocksInFlight == 0)) { + pnode->fDisconnect = true; + LogPrint(BCLog::NET, "disconnecting extra block-relay-only peer=%d (last block received at time %d)\n", + pnode->GetId(), count_seconds(pnode->m_last_block_time)); + return true; + } else { + LogPrint(BCLog::NET, "keeping block-relay-only peer=%d chosen for eviction (connect time: %d, blocks_in_flight: %d)\n", + pnode->GetId(), count_seconds(pnode->m_connected), node_state->nBlocksInFlight); + } + return false; + }); + } + + // Check whether we have too many outbound-full-relay peers + if (m_connman.GetExtraFullOutboundCount() > 0) { + // If we have more outbound-full-relay peers than we target, disconnect one. + // Pick the outbound-full-relay 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(); + + m_connman.ForEachNode([&](CNode* pnode) EXCLUSIVE_LOCKS_REQUIRED(::cs_main) { + AssertLockHeld(::cs_main); + + // Only consider outbound-full-relay peers that are not already + // marked for disconnection + if (!pnode->IsFullOutboundConn() || 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 = m_connman.ForNode(worst_peer, [&](CNode* pnode) EXCLUSIVE_LOCKS_REQUIRED(::cs_main) { + AssertLockHeld(::cs_main); + + // 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 (now - pnode->m_connected > 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(), count_seconds(pnode->m_connected), 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. + m_connman.SetTryNewOutboundPeer(false); + } + } + } +} + +void PeerManagerImpl::CheckForStaleTipAndEvictPeers() +{ + LOCK(cs_main); + + auto now{GetTime<std::chrono::seconds>()}; + + EvictExtraOutboundPeers(now); + + if (now > m_stale_tip_check_time) { + // Check whether our tip is stale, and if so, allow using an extra + // outbound peer + if (!fImporting && !fReindex && m_connman.GetNetworkActive() && m_connman.GetUseAddrmanOutgoing() && TipMayBeStale()) { + LogPrintf("Potential stale tip detected, will try using extra outbound peer (last tip update: %d seconds ago)\n", + count_seconds(now - m_last_tip_update.load())); + m_connman.SetTryNewOutboundPeer(true); + } else if (m_connman.GetTryNewOutboundPeer()) { + m_connman.SetTryNewOutboundPeer(false); + } + m_stale_tip_check_time = now + STALE_CHECK_INTERVAL; + } + + if (!m_initial_sync_finished && CanDirectFetch()) { + m_connman.StartExtraBlockRelayPeers(); + m_initial_sync_finished = true; + } +} + +void PeerManagerImpl::MaybeSendPing(CNode& node_to, Peer& peer, std::chrono::microseconds now) +{ + if (m_connman.ShouldRunInactivityChecks(node_to, std::chrono::duration_cast<std::chrono::seconds>(now)) && + peer.m_ping_nonce_sent && + now > peer.m_ping_start.load() + TIMEOUT_INTERVAL) + { + // The ping timeout is using mocktime. To disable the check during + // testing, increase -peertimeout. + LogPrint(BCLog::NET, "ping timeout: %fs peer=%d\n", 0.000001 * count_microseconds(now - peer.m_ping_start.load()), peer.m_id); + node_to.fDisconnect = true; + return; + } + + const CNetMsgMaker msgMaker(node_to.GetCommonVersion()); + bool pingSend = false; + + if (peer.m_ping_queued) { + // RPC ping request by user + pingSend = true; + } + + if (peer.m_ping_nonce_sent == 0 && now > peer.m_ping_start.load() + PING_INTERVAL) { + // Ping automatically sent as a latency probe & keepalive. + pingSend = true; + } + + if (pingSend) { + uint64_t nonce; + do { + nonce = GetRand<uint64_t>(); + } while (nonce == 0); + peer.m_ping_queued = false; + peer.m_ping_start = now; + if (node_to.GetCommonVersion() > BIP0031_VERSION) { + peer.m_ping_nonce_sent = nonce; + m_connman.PushMessage(&node_to, msgMaker.Make(NetMsgType::PING, nonce)); + } else { + // Peer is too old to support ping command with nonce, pong will never arrive. + peer.m_ping_nonce_sent = 0; + m_connman.PushMessage(&node_to, msgMaker.Make(NetMsgType::PING)); + } + } +} + +void PeerManagerImpl::MaybeSendAddr(CNode& node, Peer& peer, std::chrono::microseconds current_time) +{ + // Nothing to do for non-address-relay peers + if (!peer.m_addr_relay_enabled) return; + + LOCK(peer.m_addr_send_times_mutex); + // Periodically advertise our local address to the peer. + if (fListen && !m_chainman.ActiveChainstate().IsInitialBlockDownload() && + peer.m_next_local_addr_send < current_time) { + // If we've sent before, clear the bloom filter for the peer, so that our + // self-announcement will actually go out. + // This might be unnecessary if the bloom filter has already rolled + // over since our last self-announcement, but there is only a small + // bandwidth cost that we can incur by doing this (which happens + // once a day on average). + if (peer.m_next_local_addr_send != 0us) { + peer.m_addr_known->reset(); + } + if (std::optional<CAddress> local_addr = GetLocalAddrForPeer(&node)) { + FastRandomContext insecure_rand; + PushAddress(peer, *local_addr, insecure_rand); + } + peer.m_next_local_addr_send = GetExponentialRand(current_time, AVG_LOCAL_ADDRESS_BROADCAST_INTERVAL); + } + + // We sent an `addr` message to this peer recently. Nothing more to do. + if (current_time <= peer.m_next_addr_send) return; + + peer.m_next_addr_send = GetExponentialRand(current_time, AVG_ADDRESS_BROADCAST_INTERVAL); + + if (!Assume(peer.m_addrs_to_send.size() <= MAX_ADDR_TO_SEND)) { + // Should be impossible since we always check size before adding to + // m_addrs_to_send. Recover by trimming the vector. + peer.m_addrs_to_send.resize(MAX_ADDR_TO_SEND); + } + + // Remove addr records that the peer already knows about, and add new + // addrs to the m_addr_known filter on the same pass. + auto addr_already_known = [&peer](const CAddress& addr) { + bool ret = peer.m_addr_known->contains(addr.GetKey()); + if (!ret) peer.m_addr_known->insert(addr.GetKey()); + return ret; + }; + peer.m_addrs_to_send.erase(std::remove_if(peer.m_addrs_to_send.begin(), peer.m_addrs_to_send.end(), addr_already_known), + peer.m_addrs_to_send.end()); + + // No addr messages to send + if (peer.m_addrs_to_send.empty()) return; + + const char* msg_type; + int make_flags; + if (peer.m_wants_addrv2) { + msg_type = NetMsgType::ADDRV2; + make_flags = ADDRV2_FORMAT; + } else { + msg_type = NetMsgType::ADDR; + make_flags = 0; + } + m_connman.PushMessage(&node, CNetMsgMaker(node.GetCommonVersion()).Make(make_flags, msg_type, peer.m_addrs_to_send)); + peer.m_addrs_to_send.clear(); + + // we only send the big addr message once + if (peer.m_addrs_to_send.capacity() > 40) { + peer.m_addrs_to_send.shrink_to_fit(); + } +} + +void PeerManagerImpl::MaybeSendFeefilter(CNode& pto, Peer& peer, std::chrono::microseconds current_time) +{ + if (m_ignore_incoming_txs) return; + if (!peer.m_tx_relay) return; + if (pto.GetCommonVersion() < FEEFILTER_VERSION) return; + // peers with the forcerelay permission should not filter txs to us + if (pto.HasPermission(NetPermissionFlags::ForceRelay)) return; + + CAmount currentFilter = m_mempool.GetMinFee(gArgs.GetIntArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000).GetFeePerK(); + static FeeFilterRounder g_filter_rounder{CFeeRate{DEFAULT_MIN_RELAY_TX_FEE}}; + + if (m_chainman.ActiveChainstate().IsInitialBlockDownload()) { + // Received tx-inv messages are discarded when the active + // chainstate is in IBD, so tell the peer to not send them. + currentFilter = MAX_MONEY; + } else { + static const CAmount MAX_FILTER{g_filter_rounder.round(MAX_MONEY)}; + if (peer.m_tx_relay->m_fee_filter_sent == MAX_FILTER) { + // Send the current filter if we sent MAX_FILTER previously + // and made it out of IBD. + peer.m_tx_relay->m_next_send_feefilter = 0us; + } + } + if (current_time > peer.m_tx_relay->m_next_send_feefilter) { + CAmount filterToSend = g_filter_rounder.round(currentFilter); + // We always have a fee filter of at least minRelayTxFee + filterToSend = std::max(filterToSend, ::minRelayTxFee.GetFeePerK()); + if (filterToSend != peer.m_tx_relay->m_fee_filter_sent) { + m_connman.PushMessage(&pto, CNetMsgMaker(pto.GetCommonVersion()).Make(NetMsgType::FEEFILTER, filterToSend)); + peer.m_tx_relay->m_fee_filter_sent = filterToSend; + } + peer.m_tx_relay->m_next_send_feefilter = GetExponentialRand(current_time, AVG_FEEFILTER_BROADCAST_INTERVAL); + } + // If the fee filter has changed substantially and it's still more than MAX_FEEFILTER_CHANGE_DELAY + // until scheduled broadcast, then move the broadcast to within MAX_FEEFILTER_CHANGE_DELAY. + else if (current_time + MAX_FEEFILTER_CHANGE_DELAY < peer.m_tx_relay->m_next_send_feefilter && + (currentFilter < 3 * peer.m_tx_relay->m_fee_filter_sent / 4 || currentFilter > 4 * peer.m_tx_relay->m_fee_filter_sent / 3)) { + peer.m_tx_relay->m_next_send_feefilter = current_time + GetRandomDuration<std::chrono::microseconds>(MAX_FEEFILTER_CHANGE_DELAY); + } +} + +namespace { +class CompareInvMempoolOrder +{ + CTxMemPool *mp; + bool m_wtxid_relay; +public: + explicit CompareInvMempoolOrder(CTxMemPool *_mempool, bool use_wtxid) + { + mp = _mempool; + m_wtxid_relay = use_wtxid; + } + + bool operator()(std::set<uint256>::iterator a, std::set<uint256>::iterator b) + { + /* As std::make_heap produces a max-heap, we want the entries with the + * fewest ancestors/highest fee to sort later. */ + return mp->CompareDepthAndScore(*b, *a, m_wtxid_relay); + } +}; +} + +bool PeerManagerImpl::SetupAddressRelay(const CNode& node, Peer& peer) +{ + // We don't participate in addr relay with outbound block-relay-only + // connections to prevent providing adversaries with the additional + // information of addr traffic to infer the link. + if (node.IsBlockOnlyConn()) return false; + + if (!peer.m_addr_relay_enabled.exchange(true)) { + // First addr message we have received from the peer, initialize + // m_addr_known + peer.m_addr_known = std::make_unique<CRollingBloomFilter>(5000, 0.001); + } + + return true; +} + +bool PeerManagerImpl::SendMessages(CNode* pto) +{ + PeerRef peer = GetPeerRef(pto->GetId()); + if (!peer) return false; + const Consensus::Params& consensusParams = m_chainparams.GetConsensus(); + + // We must call MaybeDiscourageAndDisconnect first, to ensure that we'll + // disconnect misbehaving peers even before the version handshake is complete. + if (MaybeDiscourageAndDisconnect(*pto, *peer)) return true; + + // Don't send anything until the version handshake is complete + if (!pto->fSuccessfullyConnected || pto->fDisconnect) + return true; + + // If we get here, the outgoing message serialization version is set and can't change. + const CNetMsgMaker msgMaker(pto->GetCommonVersion()); + + const auto current_time{GetTime<std::chrono::microseconds>()}; + + if (pto->IsAddrFetchConn() && current_time - pto->m_connected > 10 * AVG_ADDRESS_BROADCAST_INTERVAL) { + LogPrint(BCLog::NET, "addrfetch connection timeout; disconnecting peer=%d\n", pto->GetId()); + pto->fDisconnect = true; + return true; + } + + MaybeSendPing(*pto, *peer, current_time); + + // MaybeSendPing may have marked peer for disconnection + if (pto->fDisconnect) return true; + + MaybeSendAddr(*pto, *peer, current_time); + + { + LOCK(cs_main); + + CNodeState &state = *State(pto->GetId()); + + // Start block sync + if (m_chainman.m_best_header == nullptr) { + m_chainman.m_best_header = m_chainman.ActiveChain().Tip(); + } + bool fFetch = state.fPreferredDownload || (m_num_preferred_download_peers == 0 && !pto->fClient && !pto->IsAddrFetchConn()); // 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) { + // Only actively request headers from a single peer, unless we're close to today. + if ((nSyncStarted == 0 && fFetch) || m_chainman.m_best_header->GetBlockTime() > GetAdjustedTime() - 24 * 60 * 60) { + state.fSyncStarted = true; + state.m_headers_sync_timeout = current_time + HEADERS_DOWNLOAD_TIMEOUT_BASE + + ( + // Convert HEADERS_DOWNLOAD_TIMEOUT_PER_HEADER to microseconds before scaling + // to maintain precision + std::chrono::microseconds{HEADERS_DOWNLOAD_TIMEOUT_PER_HEADER} * + (GetAdjustedTime() - m_chainman.m_best_header->GetBlockTime()) / consensusParams.nPowTargetSpacing + ); + nSyncStarted++; + const CBlockIndex* pindexStart = m_chainman.m_best_header; + /* If possible, start at the block preceding the currently + best known header. This ensures that we always get a + non-empty list of headers back as long as the peer + is up-to-date. With a non-empty response, we can initialise + the peer's known best block. This wouldn't be possible + if we requested starting at m_chainman.m_best_header and + got back an empty response. */ + if (pindexStart->pprev) + pindexStart = pindexStart->pprev; + LogPrint(BCLog::NET, "initial getheaders (%d) to peer=%d (startheight:%d)\n", pindexStart->nHeight, pto->GetId(), peer->m_starting_height); + m_connman.PushMessage(pto, msgMaker.Make(NetMsgType::GETHEADERS, m_chainman.ActiveChain().GetLocator(pindexStart), uint256())); + } + } + + // + // Try sending block announcements via headers + // + { + // If we have less than MAX_BLOCKS_TO_ANNOUNCE in our + // list of block hashes we're relaying, and our peer wants + // headers announcements, then find the first header + // not yet known to our peer but would connect, and send. + // If no header would connect, or if we have too many + // blocks, or if the peer doesn't want headers, just + // add all to the inv queue. + LOCK(peer->m_block_inv_mutex); + std::vector<CBlock> vHeaders; + bool fRevertToInv = ((!state.fPreferHeaders && + (!state.fPreferHeaderAndIDs || peer->m_blocks_for_headers_relay.size() > 1)) || + peer->m_blocks_for_headers_relay.size() > MAX_BLOCKS_TO_ANNOUNCE); + const CBlockIndex *pBestIndex = nullptr; // last header queued for delivery + ProcessBlockAvailability(pto->GetId()); // ensure pindexBestKnownBlock is up-to-date + + if (!fRevertToInv) { + bool fFoundStartingHeader = false; + // Try to find first header that our peer doesn't have, and + // then send all headers past that one. If we come across any + // headers that aren't on m_chainman.ActiveChain(), give up. + for (const uint256& hash : peer->m_blocks_for_headers_relay) { + const CBlockIndex* pindex = m_chainman.m_blockman.LookupBlockIndex(hash); + assert(pindex); + if (m_chainman.ActiveChain()[pindex->nHeight] != pindex) { + // Bail out if we reorged away from this block + fRevertToInv = true; + break; + } + 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 + // regular operation (because reorgs should take us to + // a chain that has some block not on the prior chain, + // which should be caught by the prior check), but one + // way this could happen is by using invalidateblock / + // reconsiderblock repeatedly on the tip, causing it to + // be added multiple times to m_blocks_for_headers_relay. + // Robustly deal with this rare situation by reverting + // to an inv. + fRevertToInv = true; + break; + } + pBestIndex = pindex; + if (fFoundStartingHeader) { + // add this to the headers message + vHeaders.push_back(pindex->GetBlockHeader()); + } else if (PeerHasHeader(&state, pindex)) { + continue; // keep looking for the first new block + } 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; + vHeaders.push_back(pindex->GetBlockHeader()); + } else { + // Peer doesn't have this header or the prior one -- nothing will + // connect, so bail out. + fRevertToInv = true; + break; + } + } + } + if (!fRevertToInv && !vHeaders.empty()) { + if (vHeaders.size() == 1 && state.fPreferHeaderAndIDs) { + // We only send up to 1 block as header-and-ids, as otherwise + // probably means we're doing an initial-ish-sync or they're slow + LogPrint(BCLog::NET, "%s sending header-and-ids %s to peer=%d\n", __func__, + vHeaders.front().GetHash().ToString(), pto->GetId()); + + int nSendFlags = state.fWantsCmpctWitness ? 0 : SERIALIZE_TRANSACTION_NO_WITNESS; + + bool fGotBlockFromCache = false; + { + LOCK(m_most_recent_block_mutex); + if (m_most_recent_block_hash == pBestIndex->GetBlockHash()) { + if (state.fWantsCmpctWitness || !m_most_recent_compact_block_has_witnesses) + m_connman.PushMessage(pto, msgMaker.Make(nSendFlags, NetMsgType::CMPCTBLOCK, *m_most_recent_compact_block)); + else { + CBlockHeaderAndShortTxIDs cmpctblock(*m_most_recent_block, state.fWantsCmpctWitness); + m_connman.PushMessage(pto, msgMaker.Make(nSendFlags, NetMsgType::CMPCTBLOCK, cmpctblock)); + } + fGotBlockFromCache = true; + } + } + if (!fGotBlockFromCache) { + CBlock block; + bool ret = ReadBlockFromDisk(block, pBestIndex, consensusParams); + assert(ret); + CBlockHeaderAndShortTxIDs cmpctblock(block, state.fWantsCmpctWitness); + m_connman.PushMessage(pto, msgMaker.Make(nSendFlags, NetMsgType::CMPCTBLOCK, cmpctblock)); + } + state.pindexBestHeaderSent = pBestIndex; + } else if (state.fPreferHeaders) { + if (vHeaders.size() > 1) { + LogPrint(BCLog::NET, "%s: %u headers, range (%s, %s), to peer=%d\n", __func__, + vHeaders.size(), + vHeaders.front().GetHash().ToString(), + vHeaders.back().GetHash().ToString(), pto->GetId()); + } else { + LogPrint(BCLog::NET, "%s: sending header %s to peer=%d\n", __func__, + vHeaders.front().GetHash().ToString(), pto->GetId()); + } + m_connman.PushMessage(pto, msgMaker.Make(NetMsgType::HEADERS, vHeaders)); + state.pindexBestHeaderSent = pBestIndex; + } else + fRevertToInv = true; + } + if (fRevertToInv) { + // If falling back to using an inv, just try to inv the tip. + // The last entry in m_blocks_for_headers_relay was our tip at some point + // in the past. + if (!peer->m_blocks_for_headers_relay.empty()) { + const uint256& hashToAnnounce = peer->m_blocks_for_headers_relay.back(); + const CBlockIndex* pindex = m_chainman.m_blockman.LookupBlockIndex(hashToAnnounce); + assert(pindex); + + // Warn if we're announcing a block that is not on the main chain. + // This should be very rare and could be optimized out. + // Just log for now. + if (m_chainman.ActiveChain()[pindex->nHeight] != pindex) { + LogPrint(BCLog::NET, "Announcing block %s not on main chain (tip=%s)\n", + hashToAnnounce.ToString(), m_chainman.ActiveChain().Tip()->GetBlockHash().ToString()); + } + + // If the peer's chain has this block, don't inv it back. + if (!PeerHasHeader(&state, pindex)) { + peer->m_blocks_for_inv_relay.push_back(hashToAnnounce); + LogPrint(BCLog::NET, "%s: sending inv peer=%d hash=%s\n", __func__, + pto->GetId(), hashToAnnounce.ToString()); + } + } + } + peer->m_blocks_for_headers_relay.clear(); + } + + // + // Message: inventory + // + std::vector<CInv> vInv; + { + LOCK(peer->m_block_inv_mutex); + vInv.reserve(std::max<size_t>(peer->m_blocks_for_inv_relay.size(), INVENTORY_BROADCAST_MAX)); + + // Add blocks + for (const uint256& hash : peer->m_blocks_for_inv_relay) { + vInv.push_back(CInv(MSG_BLOCK, hash)); + if (vInv.size() == MAX_INV_SZ) { + m_connman.PushMessage(pto, msgMaker.Make(NetMsgType::INV, vInv)); + vInv.clear(); + } + } + peer->m_blocks_for_inv_relay.clear(); + } + + if (peer->m_tx_relay != nullptr) { + LOCK(peer->m_tx_relay->m_tx_inventory_mutex); + // Check whether periodic sends should happen + bool fSendTrickle = pto->HasPermission(NetPermissionFlags::NoBan); + if (peer->m_tx_relay->m_next_inv_send_time < current_time) { + fSendTrickle = true; + if (pto->IsInboundConn()) { + peer->m_tx_relay->m_next_inv_send_time = NextInvToInbounds(current_time, INBOUND_INVENTORY_BROADCAST_INTERVAL); + } else { + peer->m_tx_relay->m_next_inv_send_time = GetExponentialRand(current_time, OUTBOUND_INVENTORY_BROADCAST_INTERVAL); + } + } + + // Time to send but the peer has requested we not relay transactions. + if (fSendTrickle) { + LOCK(peer->m_tx_relay->m_bloom_filter_mutex); + if (!peer->m_tx_relay->m_relay_txs) peer->m_tx_relay->m_tx_inventory_to_send.clear(); + } + + // Respond to BIP35 mempool requests + if (fSendTrickle && peer->m_tx_relay->m_send_mempool) { + auto vtxinfo = m_mempool.infoAll(); + peer->m_tx_relay->m_send_mempool = false; + const CFeeRate filterrate{peer->m_tx_relay->m_fee_filter_received.load()}; + + LOCK(peer->m_tx_relay->m_bloom_filter_mutex); + + for (const auto& txinfo : vtxinfo) { + const uint256& hash = peer->m_wtxid_relay ? txinfo.tx->GetWitnessHash() : txinfo.tx->GetHash(); + CInv inv(peer->m_wtxid_relay ? MSG_WTX : MSG_TX, hash); + peer->m_tx_relay->m_tx_inventory_to_send.erase(hash); + // Don't send transactions that peers will not put into their mempool + if (txinfo.fee < filterrate.GetFee(txinfo.vsize)) { + continue; + } + if (peer->m_tx_relay->m_bloom_filter) { + if (!peer->m_tx_relay->m_bloom_filter->IsRelevantAndUpdate(*txinfo.tx)) continue; + } + peer->m_tx_relay->m_tx_inventory_known_filter.insert(hash); + // Responses to MEMPOOL requests bypass the m_recently_announced_invs filter. + vInv.push_back(inv); + if (vInv.size() == MAX_INV_SZ) { + m_connman.PushMessage(pto, msgMaker.Make(NetMsgType::INV, vInv)); + vInv.clear(); + } + } + peer->m_tx_relay->m_last_mempool_req = std::chrono::duration_cast<std::chrono::seconds>(current_time); + } + + // Determine transactions to relay + if (fSendTrickle) { + // Produce a vector with all candidates for sending + std::vector<std::set<uint256>::iterator> vInvTx; + vInvTx.reserve(peer->m_tx_relay->m_tx_inventory_to_send.size()); + for (std::set<uint256>::iterator it = peer->m_tx_relay->m_tx_inventory_to_send.begin(); it != peer->m_tx_relay->m_tx_inventory_to_send.end(); it++) { + vInvTx.push_back(it); + } + const CFeeRate filterrate{peer->m_tx_relay->m_fee_filter_received.load()}; + // Topologically and fee-rate sort the inventory we send for privacy and priority reasons. + // A heap is used so that not all items need sorting if only a few are being sent. + CompareInvMempoolOrder compareInvMempoolOrder(&m_mempool, peer->m_wtxid_relay); + std::make_heap(vInvTx.begin(), vInvTx.end(), compareInvMempoolOrder); + // No reason to drain out at many times the network's capacity, + // especially since we have many peers and some will draw much shorter delays. + unsigned int nRelayedTransactions = 0; + LOCK(peer->m_tx_relay->m_bloom_filter_mutex); + while (!vInvTx.empty() && nRelayedTransactions < INVENTORY_BROADCAST_MAX) { + // Fetch the top element from the heap + std::pop_heap(vInvTx.begin(), vInvTx.end(), compareInvMempoolOrder); + std::set<uint256>::iterator it = vInvTx.back(); + vInvTx.pop_back(); + uint256 hash = *it; + CInv inv(peer->m_wtxid_relay ? MSG_WTX : MSG_TX, hash); + // Remove it from the to-be-sent set + peer->m_tx_relay->m_tx_inventory_to_send.erase(it); + // Check if not in the filter already + if (peer->m_tx_relay->m_tx_inventory_known_filter.contains(hash)) { + continue; + } + // Not in the mempool anymore? don't bother sending it. + auto txinfo = m_mempool.info(ToGenTxid(inv)); + if (!txinfo.tx) { + continue; + } + auto txid = txinfo.tx->GetHash(); + auto wtxid = txinfo.tx->GetWitnessHash(); + // Peer told you to not send transactions at that feerate? Don't bother sending it. + if (txinfo.fee < filterrate.GetFee(txinfo.vsize)) { + continue; + } + if (peer->m_tx_relay->m_bloom_filter && !peer->m_tx_relay->m_bloom_filter->IsRelevantAndUpdate(*txinfo.tx)) continue; + // Send + State(pto->GetId())->m_recently_announced_invs.insert(hash); + vInv.push_back(inv); + nRelayedTransactions++; + { + // Expire old relay messages + while (!g_relay_expiration.empty() && g_relay_expiration.front().first < current_time) + { + mapRelay.erase(g_relay_expiration.front().second); + g_relay_expiration.pop_front(); + } + + auto ret = mapRelay.emplace(txid, std::move(txinfo.tx)); + if (ret.second) { + g_relay_expiration.emplace_back(current_time + RELAY_TX_CACHE_TIME, ret.first); + } + // Add wtxid-based lookup into mapRelay as well, so that peers can request by wtxid + auto ret2 = mapRelay.emplace(wtxid, ret.first->second); + if (ret2.second) { + g_relay_expiration.emplace_back(current_time + RELAY_TX_CACHE_TIME, ret2.first); + } + } + if (vInv.size() == MAX_INV_SZ) { + m_connman.PushMessage(pto, msgMaker.Make(NetMsgType::INV, vInv)); + vInv.clear(); + } + peer->m_tx_relay->m_tx_inventory_known_filter.insert(hash); + if (hash != txid) { + // Insert txid into m_tx_inventory_known_filter, even for + // wtxidrelay peers. This prevents re-adding of + // unconfirmed parents to the recently_announced + // filter, when a child tx is requested. See + // ProcessGetData(). + peer->m_tx_relay->m_tx_inventory_known_filter.insert(txid); + } + } + } + } + if (!vInv.empty()) + m_connman.PushMessage(pto, msgMaker.Make(NetMsgType::INV, vInv)); + + // Detect whether we're stalling + if (state.m_stalling_since.count() && state.m_stalling_since < current_time - BLOCK_STALLING_TIMEOUT) { + // Stalling only triggers when the block download window cannot move. During normal steady state, + // the download window should be much larger than the to-be-downloaded set of blocks, so disconnection + // should only happen during initial block download. + LogPrintf("Peer=%d is stalling block download, disconnecting\n", pto->GetId()); + pto->fDisconnect = true; + return true; + } + // In case there is a block that has been in flight from this peer for block_interval * (1 + 0.5 * N) + // (with N the number of peers from which we're downloading validated blocks), disconnect due to timeout. + // We compensate for other peers to prevent killing off peers due to our own downstream link + // being saturated. We only count validated in-flight blocks so peers can't advertise non-existing block hashes + // to unreasonably increase our timeout. + if (state.vBlocksInFlight.size() > 0) { + QueuedBlock &queuedBlock = state.vBlocksInFlight.front(); + int nOtherPeersWithValidatedDownloads = m_peers_downloading_from - 1; + if (current_time > state.m_downloading_since + std::chrono::seconds{consensusParams.nPowTargetSpacing} * (BLOCK_DOWNLOAD_TIMEOUT_BASE + BLOCK_DOWNLOAD_TIMEOUT_PER_PEER * nOtherPeersWithValidatedDownloads)) { + LogPrintf("Timeout downloading block %s from peer=%d, disconnecting\n", queuedBlock.pindex->GetBlockHash().ToString(), pto->GetId()); + pto->fDisconnect = true; + return true; + } + } + // Check for headers sync timeouts + if (state.fSyncStarted && state.m_headers_sync_timeout < std::chrono::microseconds::max()) { + // Detect whether this is a stalling initial-headers-sync peer + if (m_chainman.m_best_header->GetBlockTime() <= GetAdjustedTime() - 24 * 60 * 60) { + if (current_time > state.m_headers_sync_timeout && nSyncStarted == 1 && (m_num_preferred_download_peers - state.fPreferredDownload >= 1)) { + // Disconnect a peer (without NetPermissionFlags::NoBan permission) if it is our only sync peer, + // and we have others we could be using instead. + // Note: If all our peers are inbound, then we won't + // disconnect our sync peer for stalling; we have bigger + // problems if we can't get any outbound peers. + if (!pto->HasPermission(NetPermissionFlags::NoBan)) { + LogPrintf("Timeout downloading headers from peer=%d, disconnecting\n", pto->GetId()); + pto->fDisconnect = true; + return true; + } else { + LogPrintf("Timeout downloading headers from noban peer=%d, not disconnecting\n", pto->GetId()); + // Reset the headers sync state so that we have a + // chance to try downloading from a different peer. + // Note: this will also result in at least one more + // getheaders message to be sent to + // this peer (eventually). + state.fSyncStarted = false; + nSyncStarted--; + state.m_headers_sync_timeout = 0us; + } + } + } else { + // After we've caught up once, reset the timeout so we can't trigger + // disconnect later. + state.m_headers_sync_timeout = std::chrono::microseconds::max(); + } + } + + // 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<std::chrono::seconds>()); + + // + // Message: getdata (blocks) + // + std::vector<CInv> vGetData; + if (!pto->fClient && ((fFetch && !pto->m_limited_node) || !m_chainman.ActiveChainstate().IsInitialBlockDownload()) && state.nBlocksInFlight < MAX_BLOCKS_IN_TRANSIT_PER_PEER) { + std::vector<const CBlockIndex*> vToDownload; + NodeId staller = -1; + FindNextBlocksToDownload(pto->GetId(), MAX_BLOCKS_IN_TRANSIT_PER_PEER - state.nBlocksInFlight, vToDownload, staller); + for (const CBlockIndex *pindex : vToDownload) { + uint32_t nFetchFlags = GetFetchFlags(*pto); + vGetData.push_back(CInv(MSG_BLOCK | nFetchFlags, pindex->GetBlockHash())); + BlockRequested(pto->GetId(), *pindex); + LogPrint(BCLog::NET, "Requesting block %s (%d) peer=%d\n", pindex->GetBlockHash().ToString(), + pindex->nHeight, pto->GetId()); + } + if (state.nBlocksInFlight == 0 && staller != -1) { + if (State(staller)->m_stalling_since == 0us) { + State(staller)->m_stalling_since = current_time; + LogPrint(BCLog::NET, "Stall started peer=%d\n", staller); + } + } + } + + // + // Message: getdata (transactions) + // + std::vector<std::pair<NodeId, GenTxid>> expired; + auto requestable = m_txrequest.GetRequestable(pto->GetId(), current_time, &expired); + for (const auto& entry : expired) { + LogPrint(BCLog::NET, "timeout of inflight %s %s from peer=%d\n", entry.second.IsWtxid() ? "wtx" : "tx", + entry.second.GetHash().ToString(), entry.first); + } + for (const GenTxid& gtxid : requestable) { + if (!AlreadyHaveTx(gtxid)) { + 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. This is just a belt-and-suspenders, as + // this should already be called whenever a transaction becomes AlreadyHaveTx(). + m_txrequest.ForgetTxHash(gtxid.GetHash()); + } + } + + + if (!vGetData.empty()) + m_connman.PushMessage(pto, msgMaker.Make(NetMsgType::GETDATA, vGetData)); + } // release cs_main + MaybeSendFeefilter(*pto, *peer, current_time); + return true; +} |