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bitcoin/src/net_processing.cpp

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// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2022 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 <headerssync.h>
#include <index/blockfilterindex.h>
#include <kernel/chain.h>
#include <kernel/mempool_entry.h>
#include <logging.h>
#include <merkleblock.h>
#include <netbase.h>
#include <netmessagemaker.h>
#include <node/blockstorage.h>
#include <node/timeoffsets.h>
#include <node/txreconciliation.h>
#include <policy/fees.h>
#include <policy/policy.h>
#include <policy/settings.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>
#include <util/strencodings.h>
#include <util/time.h>
#include <util/trace.h>
#include <validation.h>
#include <algorithm>
#include <atomic>
#include <future>
#include <memory>
#include <optional>
#include <typeinfo>
#include <utility>
/** 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;
/** How long to wait for a peer to respond to a getheaders request */
static constexpr auto HEADERS_RESPONSE_TIME{2min};
/** 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;
/** Default time during which a peer must stall block download progress before being disconnected.
* the actual timeout is increased temporarily if peers are disconnected for hitting the timeout */
static constexpr auto BLOCK_STALLING_TIMEOUT_DEFAULT{2s};
/** Maximum timeout for stalling block download. */
static constexpr auto BLOCK_STALLING_TIMEOUT_MAX{64s};
/** 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_NUM_UNCONNECTING_HEADERS_MSGS = 10;
/** Minimum blocks required to signal NODE_NETWORK_LIMITED */
static const unsigned int NODE_NETWORK_LIMITED_MIN_BLOCKS = 288;
/** Window, in blocks, for connecting to NODE_NETWORK_LIMITED peers */
static const unsigned int NODE_NETWORK_LIMITED_ALLOW_CONN_BLOCKS = 144;
/** 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;
/** Target number of tx inventory items to send per transmission. */
static constexpr unsigned int INVENTORY_BROADCAST_TARGET = INVENTORY_BROADCAST_PER_SECOND * count_seconds(INBOUND_INVENTORY_BROADCAST_INTERVAL);
/** Maximum number of inventory items to send per transmission. */
static constexpr unsigned int INVENTORY_BROADCAST_MAX = 1000;
static_assert(INVENTORY_BROADCAST_MAX >= INVENTORY_BROADCAST_TARGET, "INVENTORY_BROADCAST_MAX too low");
static_assert(INVENTORY_BROADCAST_MAX <= MAX_PEER_TX_ANNOUNCEMENTS, "INVENTORY_BROADCAST_MAX too high");
/** 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};
/** The compactblocks version we support. See BIP 152. */
static constexpr uint64_t CMPCTBLOCKS_VERSION{2};
// 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};
/** Services we offered to this peer.
*
* This is supplied by CConnman during peer initialization. It's const
* because there is no protocol defined for renegotiating services
* initially offered to a peer. The set of local services we offer should
* not change after initialization.
*
* An interesting example of this is NODE_NETWORK and initial block
* download: a node which starts up from scratch doesn't have any blocks
* to serve, but still advertises NODE_NETWORK because it will eventually
* fulfill this role after IBD completes. P2P code is written in such a
* way that it can gracefully handle peers who don't make good on their
* service advertisements. */
const ServiceFlags m_our_services;
/** Services this peer offered to us. */
std::atomic<ServiceFlags> m_their_services{NODE_NONE};
/** 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};
/** The feerate in the most recent BIP133 `feefilter` message sent to the peer.
* It is *not* a p2p protocol violation for the peer to send us
* transactions with a lower fee rate than this. See BIP133. */
CAmount m_fee_filter_sent GUARDED_BY(NetEventsInterface::g_msgproc_mutex){0};
/** Timestamp after which we will send the next BIP133 `feefilter` message
* to the peer. */
std::chrono::microseconds m_next_send_feefilter GUARDED_BY(NetEventsInterface::g_msgproc_mutex){0};
struct TxRelay {
mutable RecursiveMutex m_bloom_filter_mutex;
/** Whether we relay transactions to this peer. */
bool m_relay_txs GUARDED_BY(m_bloom_filter_mutex){false};
/** A bloom filter for which transactions to announce to the peer. See BIP37. */
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;
/** A filter of all the (w)txids that the peer has announced to
* us or we have announced to the peer. We use this to avoid announcing
* the same (w)txid to a peer that already has the transaction. */
CRollingBloomFilter m_tx_inventory_known_filter GUARDED_BY(m_tx_inventory_mutex){50000, 0.000001};
/** Set of transaction ids we still have to announce (txid for
* non-wtxid-relay peers, wtxid for wtxid-relay peers). We use the
* mempool to sort transactions in dependency order before relay, so
* this does not have to be sorted. */
std::set<uint256> m_tx_inventory_to_send GUARDED_BY(m_tx_inventory_mutex);
/** Whether the peer has requested us to send our complete mempool. Only
* permitted if the peer has NetPermissionFlags::Mempool or we advertise
* NODE_BLOOM. See BIP35. */
bool m_send_mempool GUARDED_BY(m_tx_inventory_mutex){false};
/** The next time after which we will send an `inv` message containing
* transaction announcements to this peer. */
std::chrono::microseconds m_next_inv_send_time GUARDED_BY(m_tx_inventory_mutex){0};
/** The mempool sequence num at which we sent the last `inv` message to this peer.
* Can relay txs with lower sequence numbers than this (see CTxMempool::info_for_relay). */
uint64_t m_last_inv_sequence GUARDED_BY(NetEventsInterface::g_msgproc_mutex){1};
/** Minimum fee rate with which to filter transaction announcements to this node. See BIP133. */
std::atomic<CAmount> m_fee_filter_received{0};
};
/* Initializes a TxRelay struct for this peer. Can be called at most once for a peer. */
TxRelay* SetTxRelay() EXCLUSIVE_LOCKS_REQUIRED(!m_tx_relay_mutex)
{
LOCK(m_tx_relay_mutex);
Assume(!m_tx_relay);
m_tx_relay = std::make_unique<Peer::TxRelay>();
return m_tx_relay.get();
};
TxRelay* GetTxRelay() EXCLUSIVE_LOCKS_REQUIRED(!m_tx_relay_mutex)
{
return WITH_LOCK(m_tx_relay_mutex, return m_tx_relay.get());
};
/** A vector of addresses to send to the peer, limited to MAX_ADDR_TO_SEND. */
std::vector<CAddress> m_addrs_to_send GUARDED_BY(NetEventsInterface::g_msgproc_mutex);
/** 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 GUARDED_BY(NetEventsInterface::g_msgproc_mutex);
/** 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 GUARDED_BY(NetEventsInterface::g_msgproc_mutex){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 GUARDED_BY(NetEventsInterface::g_msgproc_mutex){false};
/** Number of addresses that can be processed from this peer. Start at 1 to
* permit self-announcement. */
double m_addr_token_bucket GUARDED_BY(NetEventsInterface::g_msgproc_mutex){1.0};
/** When m_addr_token_bucket was last updated */
std::chrono::microseconds m_addr_token_timestamp GUARDED_BY(NetEventsInterface::g_msgproc_mutex){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};
/** Whether we've sent this peer a getheaders in response to an inv prior to initial-headers-sync completing */
bool m_inv_triggered_getheaders_before_sync GUARDED_BY(NetEventsInterface::g_msgproc_mutex){false};
/** 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);
/** Time of the last getheaders message to this peer */
NodeClock::time_point m_last_getheaders_timestamp GUARDED_BY(NetEventsInterface::g_msgproc_mutex){};
/** Protects m_headers_sync **/
Mutex m_headers_sync_mutex;
/** Headers-sync state for this peer (eg for initial sync, or syncing large
* reorgs) **/
std::unique_ptr<HeadersSyncState> m_headers_sync PT_GUARDED_BY(m_headers_sync_mutex) GUARDED_BY(m_headers_sync_mutex) {};
/** Whether we've sent our peer a sendheaders message. **/
std::atomic<bool> m_sent_sendheaders{false};
/** Length of current-streak of unconnecting headers announcements */
int m_num_unconnecting_headers_msgs GUARDED_BY(NetEventsInterface::g_msgproc_mutex){0};
/** When to potentially disconnect peer for stalling headers download */
std::chrono::microseconds m_headers_sync_timeout GUARDED_BY(NetEventsInterface::g_msgproc_mutex){0us};
/** Whether this peer wants invs or headers (when possible) for block announcements */
bool m_prefers_headers GUARDED_BY(NetEventsInterface::g_msgproc_mutex){false};
/** Time offset computed during the version handshake based on the
* timestamp the peer sent in the version message. */
std::atomic<std::chrono::seconds> m_time_offset{0s};
explicit Peer(NodeId id, ServiceFlags our_services)
: m_id{id}
, m_our_services{our_services}
{}
private:
mutable Mutex m_tx_relay_mutex;
/** Transaction relay data. May be a nullptr. */
std::unique_ptr<TxRelay> m_tx_relay GUARDED_BY(m_tx_relay_mutex);
};
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};
//! Whether we've started headers synchronization with this peer.
bool fSyncStarted{false};
//! 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};
//! Whether we consider this a preferred download peer.
bool fPreferredDownload{false};
/** Whether this peer wants invs or cmpctblocks (when possible) for block announcements. */
bool m_requested_hb_cmpctblocks{false};
/** Whether this peer will send us cmpctblocks if we request them. */
bool m_provides_cmpctblocks{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;
CNodeState(bool is_inbound) : m_is_inbound(is_inbound) {}
};
class PeerManagerImpl final : public PeerManager
{
public:
PeerManagerImpl(CConnman& connman, AddrMan& addrman,
BanMan* banman, ChainstateManager& chainman,
CTxMemPool& pool, Options opts);
/** Overridden from CValidationInterface. */
void BlockConnected(ChainstateRole role, const std::shared_ptr<const CBlock>& pblock, const CBlockIndex* pindexConnected) override
EXCLUSIVE_LOCKS_REQUIRED(!m_recent_confirmed_transactions_mutex);
void BlockDisconnected(const std::shared_ptr<const CBlock> &block, const CBlockIndex* pindex) override
EXCLUSIVE_LOCKS_REQUIRED(!m_recent_confirmed_transactions_mutex);
void UpdatedBlockTip(const CBlockIndex *pindexNew, const CBlockIndex *pindexFork, bool fInitialDownload) override
EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
void BlockChecked(const CBlock& block, const BlockValidationState& state) override
EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
void NewPoWValidBlock(const CBlockIndex *pindex, const std::shared_ptr<const CBlock>& pblock) override
EXCLUSIVE_LOCKS_REQUIRED(!m_most_recent_block_mutex);
/** Implement NetEventsInterface */
void InitializeNode(CNode& node, ServiceFlags our_services) override EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
void FinalizeNode(const CNode& node) override EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex, !m_headers_presync_mutex);
bool HasAllDesirableServiceFlags(ServiceFlags services) const override;
bool ProcessMessages(CNode* pfrom, std::atomic<bool>& interrupt) override
EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex, !m_recent_confirmed_transactions_mutex, !m_most_recent_block_mutex, !m_headers_presync_mutex, g_msgproc_mutex);
bool SendMessages(CNode* pto) override
EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex, !m_recent_confirmed_transactions_mutex, !m_most_recent_block_mutex, g_msgproc_mutex);
/** Implement PeerManager */
void StartScheduledTasks(CScheduler& scheduler) override;
void CheckForStaleTipAndEvictPeers() override;
std::optional<std::string> FetchBlock(NodeId peer_id, const CBlockIndex& block_index) override
EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
bool GetNodeStateStats(NodeId nodeid, CNodeStateStats& stats) const override EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
PeerManagerInfo GetInfo() const override EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
void SendPings() override EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
void RelayTransaction(const uint256& txid, const uint256& wtxid) override EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
void SetBestBlock(int height, std::chrono::seconds time) override
{
m_best_height = height;
m_best_block_time = time;
};
void UnitTestMisbehaving(NodeId peer_id, int howmuch) override EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex) { Misbehaving(*Assert(GetPeerRef(peer_id)), howmuch, ""); };
void ProcessMessage(CNode& pfrom, const std::string& msg_type, DataStream& vRecv,
const std::chrono::microseconds time_received, const std::atomic<bool>& interruptMsgProc) override
EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex, !m_recent_confirmed_transactions_mutex, !m_most_recent_block_mutex, !m_headers_presync_mutex, g_msgproc_mutex);
void UpdateLastBlockAnnounceTime(NodeId node, int64_t time_in_seconds) override;
ServiceFlags GetDesirableServiceFlags(ServiceFlags services) const override;
private:
/** Consider evicting an outbound peer based on the amount of time they've been behind our tip */
void ConsiderEviction(CNode& pto, Peer& peer, std::chrono::seconds time_in_seconds) EXCLUSIVE_LOCKS_REQUIRED(cs_main, g_msgproc_mutex);
/** 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) EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
/** 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 EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
/** 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) EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
/**
* Increment peer's misbehavior score. If the new value >= DISCOURAGEMENT_THRESHOLD, mark the node
* to be discouraged, meaning the peer might be disconnected and added to the discouragement filter.
*/
void Misbehaving(Peer& peer, int howmuch, const std::string& message);
/**
* 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 = "")
EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
/**
* 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)
EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
/** 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);
/** Handle a transaction whose result was not MempoolAcceptResult::ResultType::VALID.
* @param[in] maybe_add_extra_compact_tx Whether this tx should be added to vExtraTxnForCompact.
* Set to false if the tx has already been rejected before,
* e.g. is an orphan, to avoid adding duplicate entries.
* Updates m_txrequest, m_recent_rejects, m_recent_rejects_reconsiderable, m_orphanage, and vExtraTxnForCompact. */
void ProcessInvalidTx(NodeId nodeid, const CTransactionRef& tx, const TxValidationState& result,
bool maybe_add_extra_compact_tx)
EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex, g_msgproc_mutex, cs_main);
/** Handle a transaction whose result was MempoolAcceptResult::ResultType::VALID.
* Updates m_txrequest, m_orphanage, and vExtraTxnForCompact. Also queues the tx for relay. */
void ProcessValidTx(NodeId nodeid, const CTransactionRef& tx, const std::list<CTransactionRef>& replaced_transactions)
EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex, g_msgproc_mutex, cs_main);
struct PackageToValidate {
const Package m_txns;
const std::vector<NodeId> m_senders;
/** Construct a 1-parent-1-child package. */
explicit PackageToValidate(const CTransactionRef& parent,
const CTransactionRef& child,
NodeId parent_sender,
NodeId child_sender) :
m_txns{parent, child},
m_senders {parent_sender, child_sender}
{}
std::string ToString() const {
Assume(m_txns.size() == 2);
return strprintf("parent %s (wtxid=%s, sender=%d) + child %s (wtxid=%s, sender=%d)",
m_txns.front()->GetHash().ToString(),
m_txns.front()->GetWitnessHash().ToString(),
m_senders.front(),
m_txns.back()->GetHash().ToString(),
m_txns.back()->GetWitnessHash().ToString(),
m_senders.back());
}
};
/** Handle the results of package validation: calls ProcessValidTx and ProcessInvalidTx for
* individual transactions, and caches rejection for the package as a group.
*/
void ProcessPackageResult(const PackageToValidate& package_to_validate, const PackageMempoolAcceptResult& package_result)
EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex, g_msgproc_mutex, cs_main);
/** Look for a child of this transaction in the orphanage to form a 1-parent-1-child package,
* skipping any combinations that have already been tried. Return the resulting package along with
* the senders of its respective transactions, or std::nullopt if no package is found. */
std::optional<PackageToValidate> Find1P1CPackage(const CTransactionRef& ptx, NodeId nodeid)
EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex, g_msgproc_mutex, cs_main);
/**
* Reconsider orphan transactions after a parent has been accepted to the mempool.
*
* @peer[in] peer The peer whose orphan transactions we will reconsider. Generally only
* one orphan will be reconsidered on each call of this function. If an
* accepted orphan has orphaned children, those will need to be
* reconsidered, creating more work, possibly for other peers.
* @return True if meaningful work was done (an orphan was accepted/rejected).
* If no meaningful work was done, then the work set for this peer
* will be empty.
*/
bool ProcessOrphanTx(Peer& peer)
EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex, g_msgproc_mutex);
/** Process a single headers message from a peer.
*
* @param[in] pfrom CNode of the peer
* @param[in] peer The peer sending us the headers
* @param[in] headers The headers received. Note that this may be modified within ProcessHeadersMessage.
* @param[in] via_compact_block Whether this header came in via compact block handling.
*/
void ProcessHeadersMessage(CNode& pfrom, Peer& peer,
std::vector<CBlockHeader>&& headers,
bool via_compact_block)
EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex, !m_headers_presync_mutex, g_msgproc_mutex);
/** Various helpers for headers processing, invoked by ProcessHeadersMessage() */
/** Return true if headers are continuous and have valid proof-of-work (DoS points assigned on failure) */
bool CheckHeadersPoW(const std::vector<CBlockHeader>& headers, const Consensus::Params& consensusParams, Peer& peer);
/** Calculate an anti-DoS work threshold for headers chains */
arith_uint256 GetAntiDoSWorkThreshold();
/** Deal with state tracking and headers sync for peers that send the
* occasional non-connecting header (this can happen due to BIP 130 headers
* announcements for blocks interacting with the 2hr (MAX_FUTURE_BLOCK_TIME) rule). */
void HandleFewUnconnectingHeaders(CNode& pfrom, Peer& peer, const std::vector<CBlockHeader>& headers) EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex);
/** Return true if the headers connect to each other, false otherwise */
bool CheckHeadersAreContinuous(const std::vector<CBlockHeader>& headers) const;
/** Try to continue a low-work headers sync that has already begun.
* Assumes the caller has already verified the headers connect, and has
* checked that each header satisfies the proof-of-work target included in
* the header.
* @param[in] peer The peer we're syncing with.
* @param[in] pfrom CNode of the peer
* @param[in,out] headers The headers to be processed.
* @return True if the passed in headers were successfully processed
* as the continuation of a low-work headers sync in progress;
* false otherwise.
* If false, the passed in headers will be returned back to
* the caller.
* If true, the returned headers may be empty, indicating
* there is no more work for the caller to do; or the headers
* may be populated with entries that have passed anti-DoS
* checks (and therefore may be validated for block index
* acceptance by the caller).
*/
bool IsContinuationOfLowWorkHeadersSync(Peer& peer, CNode& pfrom,
std::vector<CBlockHeader>& headers)
EXCLUSIVE_LOCKS_REQUIRED(peer.m_headers_sync_mutex, !m_headers_presync_mutex, g_msgproc_mutex);
/** Check work on a headers chain to be processed, and if insufficient,
* initiate our anti-DoS headers sync mechanism.
*
* @param[in] peer The peer whose headers we're processing.
* @param[in] pfrom CNode of the peer
* @param[in] chain_start_header Where these headers connect in our index.
* @param[in,out] headers The headers to be processed.
*
* @return True if chain was low work (headers will be empty after
* calling); false otherwise.
*/
bool TryLowWorkHeadersSync(Peer& peer, CNode& pfrom,
const CBlockIndex* chain_start_header,
std::vector<CBlockHeader>& headers)
EXCLUSIVE_LOCKS_REQUIRED(!peer.m_headers_sync_mutex, !m_peer_mutex, !m_headers_presync_mutex, g_msgproc_mutex);
/** Return true if the given header is an ancestor of
* m_chainman.m_best_header or our current tip */
bool IsAncestorOfBestHeaderOrTip(const CBlockIndex* header) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
/** Request further headers from this peer with a given locator.
* We don't issue a getheaders message if we have a recent one outstanding.
* This returns true if a getheaders is actually sent, and false otherwise.
*/
bool MaybeSendGetHeaders(CNode& pfrom, const CBlockLocator& locator, Peer& peer) EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex);
/** Potentially fetch blocks from this peer upon receipt of a new headers tip */
void HeadersDirectFetchBlocks(CNode& pfrom, const Peer& peer, const CBlockIndex& last_header);
/** Update peer state based on received headers message */
void UpdatePeerStateForReceivedHeaders(CNode& pfrom, Peer& peer, const CBlockIndex& last_header, bool received_new_header, bool may_have_more_headers)
EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex);
void SendBlockTransactions(CNode& pfrom, Peer& peer, 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 message to a peer */
void PushMessage(CNode& node, CSerializedNetMsg&& msg) const { m_connman.PushMessage(&node, std::move(msg)); }
template <typename... Args>
void MakeAndPushMessage(CNode& node, std::string msg_type, Args&&... args) const
{
m_connman.PushMessage(&node, NetMsg::Make(std::move(msg_type), std::forward<Args>(args)...));
}
/** 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) EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex);
/** Send a single `sendheaders` message, after we have completed headers sync with a peer. */
void MaybeSendSendHeaders(CNode& node, Peer& peer) EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex);
/** 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) EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex, g_msgproc_mutex);
/** Send `feefilter` message. */
void MaybeSendFeefilter(CNode& node, Peer& peer, std::chrono::microseconds current_time) EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex);
FastRandomContext m_rng GUARDED_BY(NetEventsInterface::g_msgproc_mutex);
FeeFilterRounder m_fee_filter_rounder GUARDED_BY(NetEventsInterface::g_msgproc_mutex);
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);
std::unique_ptr<TxReconciliationTracker> m_txreconciliation;
/** The height of the best chain */
std::atomic<int> m_best_height{-1};
/** The time of the best chain tip block */
std::atomic<std::chrono::seconds> m_best_block_time{0s};
/** Next time to check for stale tip */
std::chrono::seconds m_stale_tip_check_time GUARDED_BY(cs_main){0s};
TimeOffsets m_outbound_time_offsets;
const Options m_opts;
bool RejectIncomingTxs(const CNode& peer) const;
/** Whether we've completed initial sync yet, for determining when to turn
* on extra block-relay-only peers. */
bool m_initial_sync_finished GUARDED_BY(cs_main){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 Peer& peer) const;
std::atomic<std::chrono::microseconds> m_next_inv_to_inbounds{0us};
/** Number of nodes with fSyncStarted. */
int nSyncStarted GUARDED_BY(cs_main) = 0;
/** Hash of the last block we received via INV */
uint256 m_last_block_inv_triggering_headers_sync GUARDED_BY(g_msgproc_mutex){};
/**
* 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};
/** Stalling timeout for blocks in IBD */
std::atomic<std::chrono::seconds> m_block_stalling_timeout{BLOCK_STALLING_TIMEOUT_DEFAULT};
/** Check whether we already have this gtxid in:
* - mempool
* - orphanage
* - m_recent_rejects
* - m_recent_rejects_reconsiderable (if include_reconsiderable = true)
* - m_recent_confirmed_transactions
* Also responsible for resetting m_recent_rejects and m_recent_rejects_reconsiderable if the
* chain tip has changed.
* */
bool AlreadyHaveTx(const GenTxid& gtxid, bool include_reconsiderable)
EXCLUSIVE_LOCKS_REQUIRED(cs_main, !m_recent_confirmed_transactions_mutex);
/**
* 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};
/** Block hash of chain tip the last time we reset m_recent_rejects and
* m_recent_rejects_reconsiderable. */
uint256 hashRecentRejectsChainTip GUARDED_BY(cs_main);
/**
* Filter for:
* (1) wtxids of transactions that were recently rejected by the mempool but are
* eligible for reconsideration if submitted with other transactions.
* (2) packages (see GetPackageHash) we have already rejected before and should not retry.
*
* Similar to m_recent_rejects, this filter is used to save bandwidth when e.g. all of our peers
* have larger mempools and thus lower minimum feerates than us.
*
* When a transaction's error is TxValidationResult::TX_RECONSIDERABLE (in a package or by
* itself), add its wtxid to this filter. When a package fails for any reason, add the combined
* hash to this filter.
*
* Upon receiving an announcement for a transaction, if it exists in this filter, do not
* download the txdata. When considering packages, if it exists in this filter, drop it.
*
* Reset this filter when the chain tip changes.
*
* Parameters are picked to be the same as m_recent_rejects, with the same rationale.
*/
CRollingBloomFilter m_recent_rejects_reconsiderable GUARDED_BY(::cs_main){120'000, 0.000'001};
/*
* 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
Mutex 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);
std::unique_ptr<const std::map<uint256, CTransactionRef>> m_most_recent_block_txs GUARDED_BY(m_most_recent_block_mutex);
// Data about the low-work headers synchronization, aggregated from all peers' HeadersSyncStates.
/** Mutex guarding the other m_headers_presync_* variables. */
Mutex m_headers_presync_mutex;
/** A type to represent statistics about a peer's low-work headers sync.
*
* - The first field is the total verified amount of work in that synchronization.
* - The second is:
* - nullopt: the sync is in REDOWNLOAD phase (phase 2).
* - {height, timestamp}: the sync has the specified tip height and block timestamp (phase 1).
*/
using HeadersPresyncStats = std::pair<arith_uint256, std::optional<std::pair<int64_t, uint32_t>>>;
/** Statistics for all peers in low-work headers sync. */
std::map<NodeId, HeadersPresyncStats> m_headers_presync_stats GUARDED_BY(m_headers_presync_mutex) {};
/** The peer with the most-work entry in m_headers_presync_stats. */
NodeId m_headers_presync_bestpeer GUARDED_BY(m_headers_presync_mutex) {-1};
/** The m_headers_presync_stats improved, and needs signalling. */
std::atomic_bool m_headers_presync_should_signal{false};
/** Height of the highest block announced using BIP 152 high-bandwidth mode. */
int m_highest_fast_announce GUARDED_BY(::cs_main){0};
/** Have we requested this block from a peer */
bool IsBlockRequested(const uint256& hash) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
/** Have we requested this block from an outbound peer */
bool IsBlockRequestedFromOutbound(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
* If "from_peer" is specified, then only remove the block if it is in
* flight from that peer (to avoid one peer's network traffic from
* affecting another's state).
*/
void RemoveBlockRequest(const uint256& hash, std::optional<NodeId> from_peer) 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(const Peer& peer, unsigned int count, std::vector<const CBlockIndex*>& vBlocks, NodeId& nodeStaller) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
/** Request blocks for the background chainstate, if one is in use. */
void TryDownloadingHistoricalBlocks(const Peer& peer, unsigned int count, std::vector<const CBlockIndex*>& vBlocks, const CBlockIndex* from_tip, const CBlockIndex* target_block) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
/**
* \brief Find next blocks to download from a peer after a starting block.
*
* \param vBlocks Vector of blocks to download which will be appended to.
* \param peer Peer which blocks will be downloaded from.
* \param state Pointer to the state of the peer.
* \param pindexWalk Pointer to the starting block to add to vBlocks.
* \param count Maximum number of blocks to allow in vBlocks. No more
* blocks will be added if it reaches this size.
* \param nWindowEnd Maximum height of blocks to allow in vBlocks. No
* blocks will be added above this height.
* \param activeChain Optional pointer to a chain to compare against. If
* provided, any next blocks which are already contained
* in this chain will not be appended to vBlocks, but
* instead will be used to update the
* state->pindexLastCommonBlock pointer.
* \param nodeStaller Optional pointer to a NodeId variable that will receive
* the ID of another peer that might be causing this peer
* to stall. This is set to the ID of the peer which
* first requested the first in-flight block in the
* download window. It is only set if vBlocks is empty at
* the end of this function call and if increasing
* nWindowEnd by 1 would cause it to be non-empty (which
* indicates the download might be stalled because every
* block in the window is in flight and no other peer is
* trying to download the next block).
*/
void FindNextBlocks(std::vector<const CBlockIndex*>& vBlocks, const Peer& peer, CNodeState *state, const CBlockIndex *pindexWalk, unsigned int count, int nWindowEnd, const CChain* activeChain=nullptr, NodeId* nodeStaller=nullptr) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
/* Multimap used to preserve insertion order */
typedef std::multimap<uint256, std::pair<NodeId, std::list<QueuedBlock>::iterator>> BlockDownloadMap;
BlockDownloadMap 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 Peer::TxRelay& tx_relay, const GenTxid& gtxid)
EXCLUSIVE_LOCKS_REQUIRED(!m_most_recent_block_mutex, NetEventsInterface::g_msgproc_mutex);
void ProcessGetData(CNode& pfrom, Peer& peer, const std::atomic<bool>& interruptMsgProc)
EXCLUSIVE_LOCKS_REQUIRED(!m_most_recent_block_mutex, peer.m_getdata_requests_mutex, NetEventsInterface::g_msgproc_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, bool min_pow_checked);
/** Process compact block txns */
void ProcessCompactBlockTxns(CNode& pfrom, Peer& peer, const BlockTransactions& block_transactions)
EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex, !m_most_recent_block_mutex);
/**
* 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_msgproc_mutex);
/** 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<CTransactionRef> vExtraTxnForCompact GUARDED_BY(g_msgproc_mutex);
/** Offset into vExtraTxnForCompact to insert the next tx */
size_t vExtraTxnForCompactIt GUARDED_BY(g_msgproc_mutex) = 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);
/**
* Estimates the distance, in blocks, between the best-known block and the network chain tip.
* Utilizes the best-block time and the chainparams blocks spacing to approximate it.
*/
int64_t ApproximateBestBlockDepth() const;
/**
* 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)
EXCLUSIVE_LOCKS_REQUIRED(!m_most_recent_block_mutex);
/**
* Validation logic for compact filters request handling.
*
* May disconnect from the peer in the case of a bad request.
*
* @param[in] node The node that we received the request from
* @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& node, Peer& 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] node The node that we received the request from
* @param[in] peer The peer that we received the request from
* @param[in] vRecv The raw message received
*/
void ProcessGetCFilters(CNode& node, Peer& peer, DataStream& vRecv);
/**
* Handle a cfheaders request.
*
* May disconnect from the peer in the case of a bad request.
*
* @param[in] node The node that we received the request from
* @param[in] peer The peer that we received the request from
* @param[in] vRecv The raw message received
*/
void ProcessGetCFHeaders(CNode& node, Peer& peer, DataStream& vRecv);
/**
* Handle a getcfcheckpt request.
*
* May disconnect from the peer in the case of a bad request.
*
* @param[in] node The node that we received the request from
* @param[in] peer The peer that we received the request from
* @param[in] vRecv The raw message received
*/
void ProcessGetCFCheckPt(CNode& node, Peer& peer, DataStream& 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) EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex);
void AddAddressKnown(Peer& peer, const CAddress& addr) EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex);
void PushAddress(Peer& peer, const CAddress& addr) EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex);
};
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();
}
void PeerManagerImpl::AddAddressKnown(Peer& peer, const CAddress& addr)
{
assert(peer.m_addr_known);
peer.m_addr_known->insert(addr.GetKey());
}
void PeerManagerImpl::PushAddress(Peer& peer, const CAddress& addr)
{
// 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[m_rng.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)
{
auto tx_relay = peer.GetTxRelay();
if (!tx_relay) return;
LOCK(tx_relay->m_tx_inventory_mutex);
tx_relay->m_tx_inventory_known_filter.insert(hash);
}
/** Whether this peer can serve us blocks. */
static bool CanServeBlocks(const Peer& peer)
{
return peer.m_their_services & (NODE_NETWORK|NODE_NETWORK_LIMITED);
}
/** Whether this peer can only serve limited recent blocks (e.g. because
* it prunes old blocks) */
static bool IsLimitedPeer(const Peer& peer)
{
return (!(peer.m_their_services & NODE_NETWORK) &&
(peer.m_their_services & NODE_NETWORK_LIMITED));
}
/** Whether this peer can serve us witness data */
static bool CanServeWitnesses(const Peer& peer)
{
return peer.m_their_services & NODE_WITNESS;
}
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.count(hash);
}
bool PeerManagerImpl::IsBlockRequestedFromOutbound(const uint256& hash)
{
for (auto range = mapBlocksInFlight.equal_range(hash); range.first != range.second; range.first++) {
auto [nodeid, block_it] = range.first->second;
CNodeState& nodestate = *Assert(State(nodeid));
if (!nodestate.m_is_inbound) return true;
}
return false;
}
void PeerManagerImpl::RemoveBlockRequest(const uint256& hash, std::optional<NodeId> from_peer)
{
auto range = mapBlocksInFlight.equal_range(hash);
if (range.first == range.second) {
// Block was not requested from any peer
return;
}
// We should not have requested too many of this block
Assume(mapBlocksInFlight.count(hash) <= MAX_CMPCTBLOCKS_INFLIGHT_PER_BLOCK);
while (range.first != range.second) {
auto [node_id, list_it] = range.first->second;
if (from_peer && *from_peer != node_id) {
range.first++;
continue;
}
CNodeState& state = *Assert(State(node_id));
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);
if (state.vBlocksInFlight.empty()) {
// Last validated block on the queue for this peer was received.
m_peers_downloading_from--;
}
state.m_stalling_since = 0us;
range.first = mapBlocksInFlight.erase(range.first);
}
}
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);
Assume(mapBlocksInFlight.count(hash) <= MAX_CMPCTBLOCKS_INFLIGHT_PER_BLOCK);
// Short-circuit most stuff in case it is from the same node
for (auto range = mapBlocksInFlight.equal_range(hash); range.first != range.second; range.first++) {
if (range.first->second.first == nodeid) {
if (pit) {
*pit = &range.first->second.second;
}
return false;
}
}
// Make sure it's not being fetched already from same peer.
RemoveBlockRequest(hash, nodeid);
std::list<QueuedBlock>::iterator it = state->vBlocksInFlight.insert(state->vBlocksInFlight.end(),
{&block, std::unique_ptr<PartiallyDownloadedBlock>(pit ? new PartiallyDownloadedBlock(&m_mempool) : nullptr)});
if (state->vBlocksInFlight.size() == 1) {
// We're starting a block download (batch) from this peer.
state->m_downloading_since = GetTime<std::chrono::microseconds>();
m_peers_downloading_from++;
}
auto itInFlight = mapBlocksInFlight.insert(std::make_pair(hash, std::make_pair(nodeid, it)));
if (pit) {
*pit = &itInFlight->second.second;
}
return true;
}
void PeerManagerImpl::MaybeSetPeerAsAnnouncingHeaderAndIDs(NodeId nodeid)
{
AssertLockHeld(cs_main);
// When in -blocksonly mode, never request high-bandwidth mode from peers. Our
// mempool will not contain the transactions necessary to reconstruct the
// compact block.
if (m_opts.ignore_incoming_txs) return;
CNodeState* nodestate = State(nodeid);
if (!nodestate || !nodestate->m_provides_cmpctblocks) {
// Don't request compact blocks if the peer has not signalled support
return;
}
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);
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](CNode* pnodeStop){
MakeAndPushMessage(*pnodeStop, NetMsgType::SENDCMPCT, /*high_bandwidth=*/false, /*version=*/CMPCTBLOCKS_VERSION);
// save BIP152 bandwidth state: we select peer to be low-bandwidth
pnodeStop->m_bip152_highbandwidth_to = false;
return true;
});
lNodesAnnouncingHeaderAndIDs.pop_front();
}
MakeAndPushMessage(*pfrom, NetMsgType::SENDCMPCT, /*high_bandwidth=*/true, /*version=*/CMPCTBLOCKS_VERSION);
// 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();
}
int64_t PeerManagerImpl::ApproximateBestBlockDepth() const
{
return (GetTime<std::chrono::seconds>() - m_best_block_time.load()).count() / m_chainparams.GetConsensus().nPowTargetSpacing;
}
bool PeerManagerImpl::CanDirectFetch()
{
return m_chainman.ActiveChain().Tip()->Time() > NodeClock::now() - m_chainparams.GetConsensus().PowTargetSpacing() * 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;
}
}
// Logic for calculating which blocks to download from a given peer, given our current tip.
void PeerManagerImpl::FindNextBlocksToDownload(const Peer& peer, unsigned int count, std::vector<const CBlockIndex*>& vBlocks, NodeId& nodeStaller)
{
if (count == 0)
return;
vBlocks.reserve(vBlocks.size() + count);
CNodeState *state = State(peer.m_id);
assert(state != nullptr);
// Make sure pindexBestKnownBlock is up to date, we'll need it.
ProcessBlockAvailability(peer.m_id);
if (state->pindexBestKnownBlock == nullptr || state->pindexBestKnownBlock->nChainWork < m_chainman.ActiveChain().Tip()->nChainWork || state->pindexBestKnownBlock->nChainWork < m_chainman.MinimumChainWork()) {
// 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 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;
FindNextBlocks(vBlocks, peer, state, pindexWalk, count, nWindowEnd, &m_chainman.ActiveChain(), &nodeStaller);
}
void PeerManagerImpl::TryDownloadingHistoricalBlocks(const Peer& peer, unsigned int count, std::vector<const CBlockIndex*>& vBlocks, const CBlockIndex *from_tip, const CBlockIndex* target_block)
{
Assert(from_tip);
Assert(target_block);
if (vBlocks.size() >= count) {
return;
}
vBlocks.reserve(count);
CNodeState *state = Assert(State(peer.m_id));
if (state->pindexBestKnownBlock == nullptr || state->pindexBestKnownBlock->GetAncestor(target_block->nHeight) != target_block) {
// This peer can't provide us the complete series of blocks leading up to the
// assumeutxo snapshot base.
//
// Presumably this peer's chain has less work than our ActiveChain()'s tip, or else we
// will eventually crash when we try to reorg to it. Let other logic
// deal with whether we disconnect this peer.
//
// TODO at some point in the future, we might choose to request what blocks
// this peer does have from the historical chain, despite it not having a
// complete history beneath the snapshot base.
return;
}
FindNextBlocks(vBlocks, peer, state, from_tip, count, std::min<int>(from_tip->nHeight + BLOCK_DOWNLOAD_WINDOW, target_block->nHeight));
}
void PeerManagerImpl::FindNextBlocks(std::vector<const CBlockIndex*>& vBlocks, const Peer& peer, CNodeState *state, const CBlockIndex *pindexWalk, unsigned int count, int nWindowEnd, const CChain* activeChain, NodeId* nodeStaller)
{
std::vector<const CBlockIndex*> vToFetch;
int nMaxHeight = std::min<int>(state->pindexBestKnownBlock->nHeight, nWindowEnd + 1);
bool is_limited_peer = IsLimitedPeer(peer);
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 (!CanServeWitnesses(peer) && DeploymentActiveAt(*pindex, m_chainman, Consensus::DEPLOYMENT_SEGWIT)) {
// We wouldn't download this block or its descendants from this peer.
return;
}
if (pindex->nStatus & BLOCK_HAVE_DATA || (activeChain && activeChain->Contains(pindex))) {
if (activeChain && pindex->HaveNumChainTxs()) {
state->pindexLastCommonBlock = pindex;
}
continue;
}
// Is block in-flight?
if (IsBlockRequested(pindex->GetBlockHash())) {
if (waitingfor == -1) {
// This is the first already-in-flight block.
waitingfor = mapBlocksInFlight.lower_bound(pindex->GetBlockHash())->second.first;
}
continue;
}
// 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 != peer.m_id) {
// We aren't able to fetch anything, but we would be if the download window was one larger.
if (nodeStaller) *nodeStaller = waitingfor;
}
return;
}
// Don't request blocks that go further than what limited peers can provide
if (is_limited_peer && (state->pindexBestKnownBlock->nHeight - pindex->nHeight >= static_cast<int>(NODE_NETWORK_LIMITED_MIN_BLOCKS) - 2 /* two blocks buffer for possible races */)) {
continue;
}
vBlocks.push_back(pindex);
if (vBlocks.size() == count) {
return;
}
}
}
}
} // namespace
void PeerManagerImpl::PushNodeVersion(CNode& pnode, const Peer& peer)
{
uint64_t my_services{peer.m_our_services};
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{!RejectIncomingTxs(pnode)};
MakeAndPushMessage(pnode, NetMsgType::VERSION, PROTOCOL_VERSION, my_services, nTime,
your_services, CNetAddr::V1(addr_you), // Together the pre-version-31402 serialization of CAddress "addrYou" (without nTime)
my_services, CNetAddr::V1(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.ToStringAddrPort(), 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& node, ServiceFlags our_services)
{
NodeId nodeid = node.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(node.IsInboundConn()));
assert(m_txrequest.Count(nodeid) == 0);
}
if (NetPermissions::HasFlag(node.m_permission_flags, NetPermissionFlags::BloomFilter)) {
our_services = static_cast<ServiceFlags>(our_services | NODE_BLOOM);
}
PeerRef peer = std::make_shared<Peer>(nodeid, our_services);
{
LOCK(m_peer_mutex);
m_peer_map.emplace_hint(m_peer_map.end(), nodeid, peer);
}
if (!node.IsInboundConn()) {
PushNodeVersion(node, *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) {
auto range = mapBlocksInFlight.equal_range(entry.pindex->GetBlockHash());
while (range.first != range.second) {
auto [node_id, list_it] = range.first->second;
if (node_id != nodeid) {
range.first++;
} else {
range.first = mapBlocksInFlight.erase(range.first);
}
}
}
m_orphanage.EraseForPeer(nodeid);
m_txrequest.DisconnectedPeer(nodeid);
if (m_txreconciliation) m_txreconciliation->ForgetPeer(nodeid);
m_num_preferred_download_peers -= state->fPreferredDownload;
m_peers_downloading_from -= (!state->vBlocksInFlight.empty());
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);
}
{
LOCK(m_headers_presync_mutex);
m_headers_presync_stats.erase(nodeid);
}
LogPrint(BCLog::NET, "Cleared nodestate for peer=%d\n", nodeid);
}
bool PeerManagerImpl::HasAllDesirableServiceFlags(ServiceFlags services) const
{
// Shortcut for (services & GetDesirableServiceFlags(services)) == GetDesirableServiceFlags(services)
return !(GetDesirableServiceFlags(services) & (~services));
}
ServiceFlags PeerManagerImpl::GetDesirableServiceFlags(ServiceFlags services) const
{
if (services & NODE_NETWORK_LIMITED) {
// Limited peers are desirable when we are close to the tip.
if (ApproximateBestBlockDepth() < NODE_NETWORK_LIMITED_ALLOW_CONN_BLOCKS) {
return ServiceFlags(NODE_NETWORK_LIMITED | NODE_WITNESS);
}
}
return ServiceFlags(NODE_NETWORK | NODE_WITNESS);
}
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.their_services = peer->m_their_services;
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 (auto tx_relay = peer->GetTxRelay(); tx_relay != nullptr) {
stats.m_relay_txs = WITH_LOCK(tx_relay->m_bloom_filter_mutex, return tx_relay->m_relay_txs);
stats.m_fee_filter_received = 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();
{
LOCK(peer->m_headers_sync_mutex);
if (peer->m_headers_sync) {
stats.presync_height = peer->m_headers_sync->GetPresyncHeight();
}
}
stats.time_offset = peer->m_time_offset;
return true;
}
PeerManagerInfo PeerManagerImpl::GetInfo() const
{
return PeerManagerInfo{
.median_outbound_time_offset = m_outbound_time_offsets.Median(),
.ignores_incoming_txs = m_opts.ignore_incoming_txs,
};
}
void PeerManagerImpl::AddToCompactExtraTransactions(const CTransactionRef& tx)
{
if (m_opts.max_extra_txs <= 0)
return;
if (!vExtraTxnForCompact.size())
vExtraTxnForCompact.resize(m_opts.max_extra_txs);
vExtraTxnForCompact[vExtraTxnForCompactIt] = tx;
vExtraTxnForCompactIt = (vExtraTxnForCompactIt + 1) % m_opts.max_extra_txs;
}
void PeerManagerImpl::Misbehaving(Peer& peer, int howmuch, const std::string& message)
{
assert(howmuch > 0);
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",
peer.m_id, score_before, score_now, warning, message_prefixed);
}
bool PeerManagerImpl::MaybePunishNodeForBlock(NodeId nodeid, const BlockValidationState& state,
bool via_compact_block, const std::string& message)
{
PeerRef peer{GetPeerRef(nodeid)};
switch (state.GetResult()) {
case BlockValidationResult::BLOCK_RESULT_UNSET:
break;
case BlockValidationResult::BLOCK_HEADER_LOW_WORK:
// We didn't try to process the block because the header chain may have
// too little work.
break;
// The node is providing invalid data:
case BlockValidationResult::BLOCK_CONSENSUS:
case BlockValidationResult::BLOCK_MUTATED:
if (!via_compact_block) {
if (peer) Misbehaving(*peer, 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) {
if (peer) Misbehaving(*peer, 100, message);
return true;
}
break;
}
case BlockValidationResult::BLOCK_INVALID_HEADER:
case BlockValidationResult::BLOCK_CHECKPOINT:
case BlockValidationResult::BLOCK_INVALID_PREV:
if (peer) Misbehaving(*peer, 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)
if (peer) Misbehaving(*peer, 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)
{
PeerRef peer{GetPeerRef(nodeid)};
switch (state.GetResult()) {
case TxValidationResult::TX_RESULT_UNSET:
break;
// The node is providing invalid data:
case TxValidationResult::TX_CONSENSUS:
if (peer) Misbehaving(*peer, 100, "");
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:
case TxValidationResult::TX_RECONSIDERABLE:
case TxValidationResult::TX_UNKNOWN:
break;
}
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 (m_chainman.m_blockman.LoadingBlocks()) return "Loading blocks ...";
// Ensure this peer exists and hasn't been disconnected
PeerRef peer = GetPeerRef(peer_id);
if (peer == nullptr) return "Peer does not exist";
// Ignore pre-segwit peers
if (!CanServeWitnesses(*peer)) return "Pre-SegWit peer";
LOCK(cs_main);
// Forget about all prior requests
RemoveBlockRequest(block_index.GetBlockHash(), std::nullopt);
// Mark block as in-flight
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) {
this->MakeAndPushMessage(*node, 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(CConnman& connman, AddrMan& addrman,
BanMan* banman, ChainstateManager& chainman,
CTxMemPool& pool, Options opts)
{
return std::make_unique<PeerManagerImpl>(connman, addrman, banman, chainman, pool, opts);
}
PeerManagerImpl::PeerManagerImpl(CConnman& connman, AddrMan& addrman,
BanMan* banman, ChainstateManager& chainman,
CTxMemPool& pool, Options opts)
: m_rng{opts.deterministic_rng},
m_fee_filter_rounder{CFeeRate{DEFAULT_MIN_RELAY_TX_FEE}, m_rng},
m_chainparams(chainman.GetParams()),
m_connman(connman),
m_addrman(addrman),
m_banman(banman),
m_chainman(chainman),
m_mempool(pool),
m_opts{opts}
{
// While Erlay support is incomplete, it must be enabled explicitly via -txreconciliation.
// This argument can go away after Erlay support is complete.
if (opts.reconcile_txs) {
m_txreconciliation = std::make_unique<TxReconciliationTracker>(TXRECONCILIATION_VERSION);
}
}
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 and
* possibly reduce dynamic block stalling timeout.
*/
void PeerManagerImpl::BlockConnected(
ChainstateRole role,
const std::shared_ptr<const CBlock>& pblock,
const CBlockIndex* pindex)
{
// Update this for all chainstate roles so that we don't mistakenly see peers
// helping us do background IBD as having a stale tip.
m_last_tip_update = GetTime<std::chrono::seconds>();
// In case the dynamic timeout was doubled once or more, reduce it slowly back to its default value
auto stalling_timeout = m_block_stalling_timeout.load();
Assume(stalling_timeout >= BLOCK_STALLING_TIMEOUT_DEFAULT);
if (stalling_timeout != BLOCK_STALLING_TIMEOUT_DEFAULT) {
const auto new_timeout = std::max(std::chrono::duration_cast<std::chrono::seconds>(stalling_timeout * 0.85), BLOCK_STALLING_TIMEOUT_DEFAULT);
if (m_block_stalling_timeout.compare_exchange_strong(stalling_timeout, new_timeout)) {
LogPrint(BCLog::NET, "Decreased stalling timeout to %d seconds\n", count_seconds(new_timeout));
}
}
// The following task can be skipped since we don't maintain a mempool for
// the ibd/background chainstate.
if (role == ChainstateRole::BACKGROUND) {
return;
}
m_orphanage.EraseForBlock(*pblock);
{
LOCK(m_recent_confirmed_transactions_mutex);
for (const auto& ptx : pblock->vtx) {
m_recent_confirmed_transactions.insert(ptx->GetHash().ToUint256());
if (ptx->HasWitness()) {
m_recent_confirmed_transactions.insert(ptx->GetWitnessHash().ToUint256());
}
}
}
{
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)
{
auto pcmpctblock = std::make_shared<const CBlockHeaderAndShortTxIDs>(*pblock);
LOCK(cs_main);
if (pindex->nHeight <= m_highest_fast_announce)
return;
m_highest_fast_announce = pindex->nHeight;
if (!DeploymentActiveAt(*pindex, m_chainman, Consensus::DEPLOYMENT_SEGWIT)) return;
uint256 hashBlock(pblock->GetHash());
const std::shared_future<CSerializedNetMsg> lazy_ser{
std::async(std::launch::deferred, [&] { return NetMsg::Make(NetMsgType::CMPCTBLOCK, *pcmpctblock); })};
{
auto most_recent_block_txs = std::make_unique<std::map<uint256, CTransactionRef>>();
for (const auto& tx : pblock->vtx) {
most_recent_block_txs->emplace(tx->GetHash(), tx);
most_recent_block_txs->emplace(tx->GetWitnessHash(), tx);
}
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_block_txs = std::move(most_recent_block_txs);
}
m_connman.ForEachNode([this, pindex, &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.m_requested_hb_cmpctblocks && !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()};
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)
{
SetBestBlock(pindexNew->nHeight, std::chrono::seconds{pindexNew->GetBlockTime()});
// 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.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, bool include_reconsiderable)
{
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();
m_recent_rejects_reconsiderable.reset();
}
const uint256& hash = gtxid.GetHash();
if (m_orphanage.HaveTx(gtxid)) return true;
if (include_reconsiderable && m_recent_rejects_reconsiderable.contains(hash)) 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;
auto tx_relay = peer.GetTxRelay();
if (!tx_relay) continue;
LOCK(tx_relay->m_tx_inventory_mutex);
// Only queue transactions for announcement once the version handshake
// is completed. The time of arrival for these transactions is
// otherwise at risk of leaking to a spy, if the spy is able to
// distinguish transactions received during the handshake from the rest
// in the announcement.
if (tx_relay->m_next_inv_send_time == 0s) continue;
const uint256& hash{peer.m_wtxid_relay ? wtxid : txid};
if (!tx_relay->m_tx_inventory_known_filter.contains(hash)) {
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)};
// 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);
}
}
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;
{
LOCK(m_most_recent_block_mutex);
a_recent_block = m_most_recent_block;
a_recent_compact_block = m_most_recent_compact_block;
}
bool need_activate_chain = false;
{
LOCK(cs_main);
const CBlockIndex* pindex = m_chainman.m_blockman.LookupBlockIndex(inv.hash);
if (pindex) {
if (pindex->HaveNumChainTxs() && !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;
}
// 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) && (
(((peer.m_our_services & NODE_NETWORK_LIMITED) == NODE_NETWORK_LIMITED) && ((peer.m_our_services & 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 (!m_chainman.m_blockman.ReadRawBlockFromDisk(block_data, pindex->GetBlockPos())) {
assert(!"cannot load block from disk");
}
MakeAndPushMessage(pfrom, 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 (!m_chainman.m_blockman.ReadBlockFromDisk(*pblockRead, *pindex)) {
assert(!"cannot load block from disk");
}
pblock = pblockRead;
}
if (pblock) {
if (inv.IsMsgBlk()) {
MakeAndPushMessage(pfrom, NetMsgType::BLOCK, TX_NO_WITNESS(*pblock));
} else if (inv.IsMsgWitnessBlk()) {
MakeAndPushMessage(pfrom, NetMsgType::BLOCK, TX_WITH_WITNESS(*pblock));
} else if (inv.IsMsgFilteredBlk()) {
bool sendMerkleBlock = false;
CMerkleBlock merkleBlock;
if (auto tx_relay = peer.GetTxRelay(); tx_relay != nullptr) {
LOCK(tx_relay->m_bloom_filter_mutex);
if (tx_relay->m_bloom_filter) {
sendMerkleBlock = true;
merkleBlock = CMerkleBlock(*pblock, *tx_relay->m_bloom_filter);
}
}
if (sendMerkleBlock) {
MakeAndPushMessage(pfrom, 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)
MakeAndPushMessage(pfrom, NetMsgType::TX, TX_NO_WITNESS(*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.
if (CanDirectFetch() && pindex->nHeight >= m_chainman.ActiveChain().Height() - MAX_CMPCTBLOCK_DEPTH) {
if (a_recent_compact_block && a_recent_compact_block->header.GetHash() == pindex->GetBlockHash()) {
MakeAndPushMessage(pfrom, NetMsgType::CMPCTBLOCK, *a_recent_compact_block);
} else {
CBlockHeaderAndShortTxIDs cmpctblock{*pblock};
MakeAndPushMessage(pfrom, NetMsgType::CMPCTBLOCK, cmpctblock);
}
} else {
MakeAndPushMessage(pfrom, NetMsgType::BLOCK, TX_WITH_WITNESS(*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.emplace_back(MSG_BLOCK, m_chainman.ActiveChain().Tip()->GetBlockHash());
MakeAndPushMessage(pfrom, NetMsgType::INV, vInv);
peer.m_continuation_block.SetNull();
}
}
}
CTransactionRef PeerManagerImpl::FindTxForGetData(const Peer::TxRelay& tx_relay, const GenTxid& gtxid)
{
// If a tx was in the mempool prior to the last INV for this peer, permit the request.
auto txinfo = m_mempool.info_for_relay(gtxid, tx_relay.m_last_inv_sequence);
if (txinfo.tx) {
return std::move(txinfo.tx);
}
// Or it might be from the most recent block
{
LOCK(m_most_recent_block_mutex);
if (m_most_recent_block_txs != nullptr) {
auto it = m_most_recent_block_txs->find(gtxid.GetHash());
if (it != m_most_recent_block_txs->end()) return it->second;
}
}
return {};
}
void PeerManagerImpl::ProcessGetData(CNode& pfrom, Peer& peer, const std::atomic<bool>& interruptMsgProc)
{
AssertLockNotHeld(cs_main);
auto tx_relay = peer.GetTxRelay();
std::deque<CInv>::iterator it = peer.m_getdata_requests.begin();
std::vector<CInv> vNotFound;
// 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 (tx_relay == nullptr) {
// Ignore GETDATA requests for transactions from block-relay-only
// peers and peers that asked us not to announce transactions.
continue;
}
CTransactionRef tx = FindTxForGetData(*tx_relay, ToGenTxid(inv));
if (tx) {
// WTX and WITNESS_TX imply we serialize with witness
const auto maybe_with_witness = (inv.IsMsgTx() ? TX_NO_WITNESS : TX_WITH_WITNESS);
MakeAndPushMessage(pfrom, NetMsgType::TX, maybe_with_witness(*tx));
m_mempool.RemoveUnbroadcastTx(tx->GetHash());
} 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 announced 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.
MakeAndPushMessage(pfrom, NetMsgType::NOTFOUND, vNotFound);
}
}
uint32_t PeerManagerImpl::GetFetchFlags(const Peer& peer) const
{
uint32_t nFetchFlags = 0;
if (CanServeWitnesses(peer)) {
nFetchFlags |= MSG_WITNESS_FLAG;
}
return nFetchFlags;
}
void PeerManagerImpl::SendBlockTransactions(CNode& pfrom, Peer& peer, 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(peer, 100, "getblocktxn with out-of-bounds tx indices");
return;
}
resp.txn[i] = block.vtx[req.indexes[i]];
}
MakeAndPushMessage(pfrom, NetMsgType::BLOCKTXN, resp);
}
bool PeerManagerImpl::CheckHeadersPoW(const std::vector<CBlockHeader>& headers, const Consensus::Params& consensusParams, Peer& peer)
{
// Do these headers have proof-of-work matching what's claimed?
if (!HasValidProofOfWork(headers, consensusParams)) {
Misbehaving(peer, 100, "header with invalid proof of work");
return false;
}
// Are these headers connected to each other?
if (!CheckHeadersAreContinuous(headers)) {
Misbehaving(peer, 20, "non-continuous headers sequence");
return false;
}
return true;
}
arith_uint256 PeerManagerImpl::GetAntiDoSWorkThreshold()
{
arith_uint256 near_chaintip_work = 0;
LOCK(cs_main);
if (m_chainman.ActiveChain().Tip() != nullptr) {
const CBlockIndex *tip = m_chainman.ActiveChain().Tip();
// Use a 144 block buffer, so that we'll accept headers that fork from
// near our tip.
near_chaintip_work = tip->nChainWork - std::min<arith_uint256>(144*GetBlockProof(*tip), tip->nChainWork);
}
return std::max(near_chaintip_work, m_chainman.MinimumChainWork());
}
/**
* Special handling for unconnecting headers that might be part of a block
* announcement.
*
* We'll send a getheaders message in response to try to connect the chain.
*
* The peer can send up to MAX_NUM_UNCONNECTING_HEADERS_MSGS in a row that
* don't connect before given DoS points.
*
* Once a headers message is received that is valid and does connect,
* m_num_unconnecting_headers_msgs gets reset back to 0.
*/
void PeerManagerImpl::HandleFewUnconnectingHeaders(CNode& pfrom, Peer& peer,
const std::vector<CBlockHeader>& headers)
{
peer.m_num_unconnecting_headers_msgs++;
// Try to fill in the missing headers.
const CBlockIndex* best_header{WITH_LOCK(cs_main, return m_chainman.m_best_header)};
if (MaybeSendGetHeaders(pfrom, GetLocator(best_header), peer)) {
LogPrint(BCLog::NET, "received header %s: missing prev block %s, sending getheaders (%d) to end (peer=%d, m_num_unconnecting_headers_msgs=%d)\n",
headers[0].GetHash().ToString(),
headers[0].hashPrevBlock.ToString(),
best_header->nHeight,
pfrom.GetId(), peer.m_num_unconnecting_headers_msgs);
}
// 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.
WITH_LOCK(cs_main, UpdateBlockAvailability(pfrom.GetId(), headers.back().GetHash()));
// The peer may just be broken, so periodically assign DoS points if this
// condition persists.
if (peer.m_num_unconnecting_headers_msgs % MAX_NUM_UNCONNECTING_HEADERS_MSGS == 0) {
Misbehaving(peer, 20, strprintf("%d non-connecting headers", peer.m_num_unconnecting_headers_msgs));
}
}
bool PeerManagerImpl::CheckHeadersAreContinuous(const std::vector<CBlockHeader>& headers) const
{
uint256 hashLastBlock;
for (const CBlockHeader& header : headers) {
if (!hashLastBlock.IsNull() && header.hashPrevBlock != hashLastBlock) {
return false;
}
hashLastBlock = header.GetHash();
}
return true;
}
bool PeerManagerImpl::IsContinuationOfLowWorkHeadersSync(Peer& peer, CNode& pfrom, std::vector<CBlockHeader>& headers)
{
if (peer.m_headers_sync) {
auto result = peer.m_headers_sync->ProcessNextHeaders(headers, headers.size() == MAX_HEADERS_RESULTS);
if (result.request_more) {
auto locator = peer.m_headers_sync->NextHeadersRequestLocator();
// If we were instructed to ask for a locator, it should not be empty.
Assume(!locator.vHave.empty());
if (!locator.vHave.empty()) {
// It should be impossible for the getheaders request to fail,
// because we should have cleared the last getheaders timestamp
// when processing the headers that triggered this call. But
// it may be possible to bypass this via compactblock
// processing, so check the result before logging just to be
// safe.
bool sent_getheaders = MaybeSendGetHeaders(pfrom, locator, peer);
if (sent_getheaders) {
LogPrint(BCLog::NET, "more getheaders (from %s) to peer=%d\n",
locator.vHave.front().ToString(), pfrom.GetId());
} else {
LogPrint(BCLog::NET, "error sending next getheaders (from %s) to continue sync with peer=%d\n",
locator.vHave.front().ToString(), pfrom.GetId());
}
}
}
if (peer.m_headers_sync->GetState() == HeadersSyncState::State::FINAL) {
peer.m_headers_sync.reset(nullptr);
// Delete this peer's entry in m_headers_presync_stats.
// If this is m_headers_presync_bestpeer, it will be replaced later
// by the next peer that triggers the else{} branch below.
LOCK(m_headers_presync_mutex);
m_headers_presync_stats.erase(pfrom.GetId());
} else {
// Build statistics for this peer's sync.
HeadersPresyncStats stats;
stats.first = peer.m_headers_sync->GetPresyncWork();
if (peer.m_headers_sync->GetState() == HeadersSyncState::State::PRESYNC) {
stats.second = {peer.m_headers_sync->GetPresyncHeight(),
peer.m_headers_sync->GetPresyncTime()};
}
// Update statistics in stats.
LOCK(m_headers_presync_mutex);
m_headers_presync_stats[pfrom.GetId()] = stats;
auto best_it = m_headers_presync_stats.find(m_headers_presync_bestpeer);
bool best_updated = false;
if (best_it == m_headers_presync_stats.end()) {
// If the cached best peer is outdated, iterate over all remaining ones (including
// newly updated one) to find the best one.
NodeId peer_best{-1};
const HeadersPresyncStats* stat_best{nullptr};
for (const auto& [peer, stat] : m_headers_presync_stats) {
if (!stat_best || stat > *stat_best) {
peer_best = peer;
stat_best = &stat;
}
}
m_headers_presync_bestpeer = peer_best;
best_updated = (peer_best == pfrom.GetId());
} else if (best_it->first == pfrom.GetId() || stats > best_it->second) {
// pfrom was and remains the best peer, or pfrom just became best.
m_headers_presync_bestpeer = pfrom.GetId();
best_updated = true;
}
if (best_updated && stats.second.has_value()) {
// If the best peer updated, and it is in its first phase, signal.
m_headers_presync_should_signal = true;
}
}
if (result.success) {
// We only overwrite the headers passed in if processing was
// successful.
headers.swap(result.pow_validated_headers);
}
return result.success;
}
// Either we didn't have a sync in progress, or something went wrong
// processing these headers, or we are returning headers to the caller to
// process.
return false;
}
bool PeerManagerImpl::TryLowWorkHeadersSync(Peer& peer, CNode& pfrom, const CBlockIndex* chain_start_header, std::vector<CBlockHeader>& headers)
{
// Calculate the claimed total work on this chain.
arith_uint256 total_work = chain_start_header->nChainWork + CalculateClaimedHeadersWork(headers);
// Our dynamic anti-DoS threshold (minimum work required on a headers chain
// before we'll store it)
arith_uint256 minimum_chain_work = GetAntiDoSWorkThreshold();
// Avoid DoS via low-difficulty-headers by only processing if the headers
// are part of a chain with sufficient work.
if (total_work < minimum_chain_work) {
// Only try to sync with this peer if their headers message was full;
// otherwise they don't have more headers after this so no point in
// trying to sync their too-little-work chain.
if (headers.size() == MAX_HEADERS_RESULTS) {
// Note: we could advance to the last header in this set that is
// known to us, rather than starting at the first header (which we
// may already have); however this is unlikely to matter much since
// ProcessHeadersMessage() already handles the case where all
// headers in a received message are already known and are
// ancestors of m_best_header or chainActive.Tip(), by skipping
// this logic in that case. So even if the first header in this set
// of headers is known, some header in this set must be new, so
// advancing to the first unknown header would be a small effect.
LOCK(peer.m_headers_sync_mutex);
peer.m_headers_sync.reset(new HeadersSyncState(peer.m_id, m_chainparams.GetConsensus(),
chain_start_header, minimum_chain_work));
// Now a HeadersSyncState object for tracking this synchronization
// is created, process the headers using it as normal. Failures are
// handled inside of IsContinuationOfLowWorkHeadersSync.
(void)IsContinuationOfLowWorkHeadersSync(peer, pfrom, headers);
} else {
LogPrint(BCLog::NET, "Ignoring low-work chain (height=%u) from peer=%d\n", chain_start_header->nHeight + headers.size(), pfrom.GetId());
}
// The peer has not yet given us a chain that meets our work threshold,
// so we want to prevent further processing of the headers in any case.
headers = {};
return true;
}
return false;
}
bool PeerManagerImpl::IsAncestorOfBestHeaderOrTip(const CBlockIndex* header)
{
if (header == nullptr) {
return false;
} else if (m_chainman.m_best_header != nullptr && header == m_chainman.m_best_header->GetAncestor(header->nHeight)) {
return true;
} else if (m_chainman.ActiveChain().Contains(header)) {
return true;
}
return false;
}
bool PeerManagerImpl::MaybeSendGetHeaders(CNode& pfrom, const CBlockLocator& locator, Peer& peer)
{
const auto current_time = NodeClock::now();
// Only allow a new getheaders message to go out if we don't have a recent
// one already in-flight
if (current_time - peer.m_last_getheaders_timestamp > HEADERS_RESPONSE_TIME) {
MakeAndPushMessage(pfrom, NetMsgType::GETHEADERS, locator, uint256());
peer.m_last_getheaders_timestamp = current_time;
return true;
}
return false;
}
/*
* Given a new headers tip ending in last_header, potentially request blocks towards that tip.
* We require that the given tip have at least as much work as our tip, and for
* our current tip to be "close to synced" (see CanDirectFetch()).
*/
void PeerManagerImpl::HeadersDirectFetchBlocks(CNode& pfrom, const Peer& peer, const CBlockIndex& last_header)
{
LOCK(cs_main);
CNodeState *nodestate = State(pfrom.GetId());
if (CanDirectFetch() && last_header.IsValid(BLOCK_VALID_TREE) && m_chainman.ActiveChain().Tip()->nChainWork <= last_header.nChainWork) {
std::vector<const CBlockIndex*> vToFetch;
const CBlockIndex* pindexWalk{&last_header};
// Calculate all the blocks we'd need to switch to last_header, 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_chainman, Consensus::DEPLOYMENT_SEGWIT) || CanServeWitnesses(peer))) {
// 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",
last_header.GetBlockHash().ToString(),
last_header.nHeight);
} else {
std::vector<CInv> vGetData;
// Download as much as possible, from earliest to latest.
for (const CBlockIndex *pindex : reverse_iterate(vToFetch)) {
if (nodestate->vBlocksInFlight.size() >= MAX_BLOCKS_IN_TRANSIT_PER_PEER) {
// Can't download any more from this peer
break;
}
uint32_t nFetchFlags = GetFetchFlags(peer);
vGetData.emplace_back(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",
last_header.GetBlockHash().ToString(),
last_header.nHeight);
}
if (vGetData.size() > 0) {
if (!m_opts.ignore_incoming_txs &&
nodestate->m_provides_cmpctblocks &&
vGetData.size() == 1 &&
mapBlocksInFlight.size() == 1 &&
last_header.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);
}
MakeAndPushMessage(pfrom, NetMsgType::GETDATA, vGetData);
}
}
}
}
/**
* Given receipt of headers from a peer ending in last_header, along with
* whether that header was new and whether the headers message was full,
* update the state we keep for the peer.
*/
void PeerManagerImpl::UpdatePeerStateForReceivedHeaders(CNode& pfrom, Peer& peer,
const CBlockIndex& last_header, bool received_new_header, bool may_have_more_headers)
{
if (peer.m_num_unconnecting_headers_msgs > 0) {
LogPrint(BCLog::NET, "peer=%d: resetting m_num_unconnecting_headers_msgs (%d -> 0)\n", pfrom.GetId(), peer.m_num_unconnecting_headers_msgs);
}
peer.m_num_unconnecting_headers_msgs = 0;
LOCK(cs_main);
CNodeState *nodestate = State(pfrom.GetId());
UpdateBlockAvailability(pfrom.GetId(), last_header.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 && last_header.nChainWork > m_chainman.ActiveChain().Tip()->nChainWork) {
nodestate->m_last_block_announcement = GetTime();
}
// 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.IsInitialBlockDownload() && !may_have_more_headers) {
// If the peer has no more headers to give us, then we know we have
// their tip.
if (nodestate->pindexBestKnownBlock && nodestate->pindexBestKnownBlock->nChainWork < m_chainman.MinimumChainWork()) {
// 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 the minimum chain work (rather than
// m_chainman.ActiveChain().Tip()) because we won't start block download
// until we have a headers chain that has at least
// the minimum chain work, 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;
}
}
}
void PeerManagerImpl::ProcessHeadersMessage(CNode& pfrom, Peer& peer,
std::vector<CBlockHeader>&& headers,
bool via_compact_block)
{
size_t nCount = headers.size();
if (nCount == 0) {
// Nothing interesting. Stop asking this peers for more headers.
// If we were in the middle of headers sync, receiving an empty headers
// message suggests that the peer suddenly has nothing to give us
// (perhaps it reorged to our chain). Clear download state for this peer.
LOCK(peer.m_headers_sync_mutex);
if (peer.m_headers_sync) {
peer.m_headers_sync.reset(nullptr);
LOCK(m_headers_presync_mutex);
m_headers_presync_stats.erase(pfrom.GetId());
}
return;
}
// Before we do any processing, make sure these pass basic sanity checks.
// We'll rely on headers having valid proof-of-work further down, as an
// anti-DoS criteria (note: this check is required before passing any
// headers into HeadersSyncState).
if (!CheckHeadersPoW(headers, m_chainparams.GetConsensus(), peer)) {
// Misbehaving() calls are handled within CheckHeadersPoW(), so we can
// just return. (Note that even if a header is announced via compact
// block, the header itself should be valid, so this type of error can
// always be punished.)
return;
}
const CBlockIndex *pindexLast = nullptr;
// We'll set already_validated_work to true if these headers are
// successfully processed as part of a low-work headers sync in progress
// (either in PRESYNC or REDOWNLOAD phase).
// If true, this will mean that any headers returned to us (ie during
// REDOWNLOAD) can be validated without further anti-DoS checks.
bool already_validated_work = false;
// If we're in the middle of headers sync, let it do its magic.
bool have_headers_sync = false;
{
LOCK(peer.m_headers_sync_mutex);
already_validated_work = IsContinuationOfLowWorkHeadersSync(peer, pfrom, headers);
// The headers we passed in may have been:
// - untouched, perhaps if no headers-sync was in progress, or some
// failure occurred
// - erased, such as if the headers were successfully processed and no
// additional headers processing needs to take place (such as if we
// are still in PRESYNC)
// - replaced with headers that are now ready for validation, such as
// during the REDOWNLOAD phase of a low-work headers sync.
// So just check whether we still have headers that we need to process,
// or not.
if (headers.empty()) {
return;
}
have_headers_sync = !!peer.m_headers_sync;
}
// Do these headers connect to something in our block index?
const CBlockIndex *chain_start_header{WITH_LOCK(::cs_main, return m_chainman.m_blockman.LookupBlockIndex(headers[0].hashPrevBlock))};
bool headers_connect_blockindex{chain_start_header != nullptr};
if (!headers_connect_blockindex) {
if (nCount <= MAX_BLOCKS_TO_ANNOUNCE) {
// If this looks like it could be a BIP 130 block announcement, use
// special logic for handling headers that don't connect, as this
// could be benign.
HandleFewUnconnectingHeaders(pfrom, peer, headers);
} else {
Misbehaving(peer, 10, "invalid header received");
}
return;
}
// If the headers we received are already in memory and an ancestor of
// m_best_header or our tip, skip anti-DoS checks. These headers will not
// use any more memory (and we are not leaking information that could be
// used to fingerprint us).
const CBlockIndex *last_received_header{nullptr};
{
LOCK(cs_main);
last_received_header = m_chainman.m_blockman.LookupBlockIndex(headers.back().GetHash());
if (IsAncestorOfBestHeaderOrTip(last_received_header)) {
already_validated_work = true;
}
}
// If our peer has NetPermissionFlags::NoBan privileges, then bypass our
// anti-DoS logic (this saves bandwidth when we connect to a trusted peer
// on startup).
if (pfrom.HasPermission(NetPermissionFlags::NoBan)) {
already_validated_work = true;
}
// At this point, the headers connect to something in our block index.
// Do anti-DoS checks to determine if we should process or store for later
// processing.
if (!already_validated_work && TryLowWorkHeadersSync(peer, pfrom,
chain_start_header, headers)) {
// If we successfully started a low-work headers sync, then there
// should be no headers to process any further.
Assume(headers.empty());
return;
}
// At this point, we have a set of headers with sufficient work on them
// which can be processed.
// If we don't have the last header, then this peer will have given us
// something new (if these headers are valid).
bool received_new_header{last_received_header == nullptr};
// Now process all the headers.
BlockValidationState state;
if (!m_chainman.ProcessNewBlockHeaders(headers, /*min_pow_checked=*/true, state, &pindexLast)) {
if (state.IsInvalid()) {
MaybePunishNodeForBlock(pfrom.GetId(), state, via_compact_block, "invalid header received");
return;
}
}
assert(pindexLast);
// Consider fetching more headers if we are not using our headers-sync mechanism.
if (nCount == MAX_HEADERS_RESULTS && !have_headers_sync) {
// Headers message had its maximum size; the peer may have more headers.
if (MaybeSendGetHeaders(pfrom, GetLocator(pindexLast), peer)) {
LogPrint(BCLog::NET, "more getheaders (%d) to end to peer=%d (startheight:%d)\n",
pindexLast->nHeight, pfrom.GetId(), peer.m_starting_height);
}
}
UpdatePeerStateForReceivedHeaders(pfrom, peer, *pindexLast, received_new_header, nCount == MAX_HEADERS_RESULTS);
// Consider immediately downloading blocks.
HeadersDirectFetchBlocks(pfrom, peer, *pindexLast);
return;
}
void PeerManagerImpl::ProcessInvalidTx(NodeId nodeid, const CTransactionRef& ptx, const TxValidationState& state,
bool maybe_add_extra_compact_tx)
{
AssertLockNotHeld(m_peer_mutex);
AssertLockHeld(g_msgproc_mutex);
AssertLockHeld(cs_main);
LogDebug(BCLog::MEMPOOLREJ, "%s (wtxid=%s) from peer=%d was not accepted: %s\n",
ptx->GetHash().ToString(),
ptx->GetWitnessHash().ToString(),
nodeid,
state.ToString());
if (state.GetResult() == TxValidationResult::TX_MISSING_INPUTS) {
return;
} 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.
if (state.GetResult() == TxValidationResult::TX_RECONSIDERABLE) {
// If the result is TX_RECONSIDERABLE, add it to m_recent_rejects_reconsiderable
// because we should not download or submit this transaction by itself again, but may
// submit it as part of a package later.
m_recent_rejects_reconsiderable.insert(ptx->GetWitnessHash().ToUint256());
} else {
m_recent_rejects.insert(ptx->GetWitnessHash().ToUint256());
}
m_txrequest.ForgetTxHash(ptx->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).
// We only add the txid if it differs from the wtxid, to avoid wasting entries in the
// rolling bloom filter.
if (state.GetResult() == TxValidationResult::TX_INPUTS_NOT_STANDARD && ptx->HasWitness()) {
m_recent_rejects.insert(ptx->GetHash().ToUint256());
m_txrequest.ForgetTxHash(ptx->GetHash());
}
if (maybe_add_extra_compact_tx && RecursiveDynamicUsage(*ptx) < 100000) {
AddToCompactExtraTransactions(ptx);
}
}
MaybePunishNodeForTx(nodeid, state);
// If the tx failed in ProcessOrphanTx, it should be removed from the orphanage unless the
// tx was still missing inputs. If the tx was not in the orphanage, EraseTx does nothing and returns 0.
if (Assume(state.GetResult() != TxValidationResult::TX_MISSING_INPUTS) && m_orphanage.EraseTx(ptx->GetHash()) > 0) {
LogDebug(BCLog::TXPACKAGES, " removed orphan tx %s (wtxid=%s)\n", ptx->GetHash().ToString(), ptx->GetWitnessHash().ToString());
}
}
void PeerManagerImpl::ProcessValidTx(NodeId nodeid, const CTransactionRef& tx, const std::list<CTransactionRef>& replaced_transactions)
{
AssertLockNotHeld(m_peer_mutex);
AssertLockHeld(g_msgproc_mutex);
AssertLockHeld(cs_main);
// As this version of the transaction was acceptable, we can forget about any requests for it.
// No-op if the tx is not in txrequest.
m_txrequest.ForgetTxHash(tx->GetHash());
m_txrequest.ForgetTxHash(tx->GetWitnessHash());
m_orphanage.AddChildrenToWorkSet(*tx);
// If it came from the orphanage, remove it. No-op if the tx is not in txorphanage.
m_orphanage.EraseTx(tx->GetHash());
LogDebug(BCLog::MEMPOOL, "AcceptToMemoryPool: peer=%d: accepted %s (wtxid=%s) (poolsz %u txn, %u kB)\n",
nodeid,
tx->GetHash().ToString(),
tx->GetWitnessHash().ToString(),
m_mempool.size(), m_mempool.DynamicMemoryUsage() / 1000);
RelayTransaction(tx->GetHash(), tx->GetWitnessHash());
for (const CTransactionRef& removedTx : replaced_transactions) {
AddToCompactExtraTransactions(removedTx);
}
}
void PeerManagerImpl::ProcessPackageResult(const PackageToValidate& package_to_validate, const PackageMempoolAcceptResult& package_result)
{
AssertLockNotHeld(m_peer_mutex);
AssertLockHeld(g_msgproc_mutex);
AssertLockHeld(cs_main);
const auto& package = package_to_validate.m_txns;
const auto& senders = package_to_validate.m_senders;
if (package_result.m_state.IsInvalid()) {
m_recent_rejects_reconsiderable.insert(GetPackageHash(package));
}
// We currently only expect to process 1-parent-1-child packages. Remove if this changes.
if (!Assume(package.size() == 2)) return;
// Iterate backwards to erase in-package descendants from the orphanage before they become
// relevant in AddChildrenToWorkSet.
auto package_iter = package.rbegin();
auto senders_iter = senders.rbegin();
while (package_iter != package.rend()) {
const auto& tx = *package_iter;
const NodeId nodeid = *senders_iter;
const auto it_result{package_result.m_tx_results.find(tx->GetWitnessHash())};
// It is not guaranteed that a result exists for every transaction.
if (it_result != package_result.m_tx_results.end()) {
const auto& tx_result = it_result->second;
switch (tx_result.m_result_type) {
case MempoolAcceptResult::ResultType::VALID:
{
ProcessValidTx(nodeid, tx, tx_result.m_replaced_transactions);
break;
}
case MempoolAcceptResult::ResultType::INVALID:
case MempoolAcceptResult::ResultType::DIFFERENT_WITNESS:
{
// Don't add to vExtraTxnForCompact, as these transactions should have already been
// added there when added to the orphanage or rejected for TX_RECONSIDERABLE.
// This should be updated if package submission is ever used for transactions
// that haven't already been validated before.
ProcessInvalidTx(nodeid, tx, tx_result.m_state, /*maybe_add_extra_compact_tx=*/false);
break;
}
case MempoolAcceptResult::ResultType::MEMPOOL_ENTRY:
{
// AlreadyHaveTx() should be catching transactions that are already in mempool.
Assume(false);
break;
}
}
}
package_iter++;
senders_iter++;
}
}
std::optional<PeerManagerImpl::PackageToValidate> PeerManagerImpl::Find1P1CPackage(const CTransactionRef& ptx, NodeId nodeid)
{
AssertLockNotHeld(m_peer_mutex);
AssertLockHeld(g_msgproc_mutex);
AssertLockHeld(cs_main);
const auto& parent_wtxid{ptx->GetWitnessHash()};
Assume(m_recent_rejects_reconsiderable.contains(parent_wtxid.ToUint256()));
// Prefer children from this peer. This helps prevent censorship attempts in which an attacker
// sends lots of fake children for the parent, and we (unluckily) keep selecting the fake
// children instead of the real one provided by the honest peer.
const auto cpfp_candidates_same_peer{m_orphanage.GetChildrenFromSamePeer(ptx, nodeid)};
// These children should be sorted from newest to oldest. In the (probably uncommon) case
// of children that replace each other, this helps us accept the highest feerate (probably the
// most recent) one efficiently.
for (const auto& child : cpfp_candidates_same_peer) {
Package maybe_cpfp_package{ptx, child};
if (!m_recent_rejects_reconsiderable.contains(GetPackageHash(maybe_cpfp_package))) {
return PeerManagerImpl::PackageToValidate{ptx, child, nodeid, nodeid};
}
}
// If no suitable candidate from the same peer is found, also try children that were provided by
// a different peer. This is useful because sometimes multiple peers announce both transactions
// to us, and we happen to download them from different peers (we wouldn't have known that these
// 2 transactions are related). We still want to find 1p1c packages then.
//
// If we start tracking all announcers of orphans, we can restrict this logic to parent + child
// pairs in which both were provided by the same peer, i.e. delete this step.
const auto cpfp_candidates_different_peer{m_orphanage.GetChildrenFromDifferentPeer(ptx, nodeid)};
// Find the first 1p1c that hasn't already been rejected. We randomize the order to not
// create a bias that attackers can use to delay package acceptance.
//
// Create a random permutation of the indices.
std::vector<size_t> tx_indices(cpfp_candidates_different_peer.size());
std::iota(tx_indices.begin(), tx_indices.end(), 0);
Shuffle(tx_indices.begin(), tx_indices.end(), m_rng);
for (const auto index : tx_indices) {
// If we already tried a package and failed for any reason, the combined hash was
// cached in m_recent_rejects_reconsiderable.
const auto [child_tx, child_sender] = cpfp_candidates_different_peer.at(index);
Package maybe_cpfp_package{ptx, child_tx};
if (!m_recent_rejects_reconsiderable.contains(GetPackageHash(maybe_cpfp_package))) {
return PeerManagerImpl::PackageToValidate{ptx, child_tx, nodeid, child_sender};
}
}
return std::nullopt;
}
bool PeerManagerImpl::ProcessOrphanTx(Peer& peer)
{
AssertLockHeld(g_msgproc_mutex);
LOCK(cs_main);
CTransactionRef porphanTx = nullptr;
while (CTransactionRef porphanTx = m_orphanage.GetTxToReconsider(peer.m_id)) {
const MempoolAcceptResult result = m_chainman.ProcessTransaction(porphanTx);
const TxValidationState& state = result.m_state;
const Txid& orphanHash = porphanTx->GetHash();
const Wtxid& orphan_wtxid = porphanTx->GetWitnessHash();
if (result.m_result_type == MempoolAcceptResult::ResultType::VALID) {
LogPrint(BCLog::TXPACKAGES, " accepted orphan tx %s (wtxid=%s)\n", orphanHash.ToString(), orphan_wtxid.ToString());
ProcessValidTx(peer.m_id, porphanTx, result.m_replaced_transactions);
return true;
} else if (state.GetResult() != TxValidationResult::TX_MISSING_INPUTS) {
LogPrint(BCLog::TXPACKAGES, " invalid orphan tx %s (wtxid=%s) from peer=%d. %s\n",
orphanHash.ToString(),
orphan_wtxid.ToString(),
peer.m_id,
state.ToString());
if (Assume(state.IsInvalid() &&
state.GetResult() != TxValidationResult::TX_UNKNOWN &&
state.GetResult() != TxValidationResult::TX_NO_MEMPOOL &&
state.GetResult() != TxValidationResult::TX_RESULT_UNSET)) {
ProcessInvalidTx(peer.m_id, porphanTx, state, /*maybe_add_extra_compact_tx=*/false);
}
return true;
}
}
return false;
}
bool PeerManagerImpl::PrepareBlockFilterRequest(CNode& node, Peer& 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.m_our_services & NODE_COMPACT_FILTERS));
if (!supported_filter_type) {
LogPrint(BCLog::NET, "peer %d requested unsupported block filter type: %d\n",
node.GetId(), static_cast<uint8_t>(filter_type));
node.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",
node.GetId(), stop_hash.ToString());
node.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 "
"start height %d and stop height %d\n",
node.GetId(), start_height, stop_height);
node.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",
node.GetId(), stop_height - start_height + 1, max_height_diff);
node.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& node, Peer& peer, DataStream& 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(node, 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) {
MakeAndPushMessage(node, NetMsgType::CFILTER, filter);
}
}
void PeerManagerImpl::ProcessGetCFHeaders(CNode& node, Peer& peer, DataStream& 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(node, 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;
}
MakeAndPushMessage(node, NetMsgType::CFHEADERS,
filter_type_ser,
stop_index->GetBlockHash(),
prev_header,
filter_hashes);
}
void PeerManagerImpl::ProcessGetCFCheckPt(CNode& node, Peer& peer, DataStream& 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(node, 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;
}
}
MakeAndPushMessage(node, NetMsgType::CFCHECKPT,
filter_type_ser,
stop_index->GetBlockHash(),
headers);
}
void PeerManagerImpl::ProcessBlock(CNode& node, const std::shared_ptr<const CBlock>& block, bool force_processing, bool min_pow_checked)
{
bool new_block{false};
m_chainman.ProcessNewBlock(block, force_processing, min_pow_checked, &new_block);
if (new_block) {
node.m_last_block_time = GetTime<std::chrono::seconds>();
// In case this block came from a different peer than we requested
// from, we can erase the block request now anyway (as we just stored
// this block to disk).
LOCK(cs_main);
RemoveBlockRequest(block->GetHash(), std::nullopt);
} else {
LOCK(cs_main);
mapBlockSource.erase(block->GetHash());
}
}
void PeerManagerImpl::ProcessCompactBlockTxns(CNode& pfrom, Peer& peer, const BlockTransactions& block_transactions)
{
std::shared_ptr<CBlock> pblock = std::make_shared<CBlock>();
bool fBlockRead{false};
{
LOCK(cs_main);
auto range_flight = mapBlocksInFlight.equal_range(block_transactions.blockhash);
size_t already_in_flight = std::distance(range_flight.first, range_flight.second);
bool requested_block_from_this_peer{false};
// Multimap ensures ordering of outstanding requests. It's either empty or first in line.
bool first_in_flight = already_in_flight == 0 || (range_flight.first->second.first == pfrom.GetId());
while (range_flight.first != range_flight.second) {
auto [node_id, block_it] = range_flight.first->second;
if (node_id == pfrom.GetId() && block_it->partialBlock) {
requested_block_from_this_peer = true;
break;
}
range_flight.first++;
}
if (!requested_block_from_this_peer) {
LogPrint(BCLog::NET, "Peer %d sent us block transactions for block we weren't expecting\n", pfrom.GetId());
return;
}
PartiallyDownloadedBlock& partialBlock = *range_flight.first->second.second->partialBlock;
ReadStatus status = partialBlock.FillBlock(*pblock, block_transactions.txn);
if (status == READ_STATUS_INVALID) {
RemoveBlockRequest(block_transactions.blockhash, pfrom.GetId()); // Reset in-flight state in case Misbehaving does not result in a disconnect
Misbehaving(peer, 100, "invalid compact block/non-matching block transactions");
return;
} else if (status == READ_STATUS_FAILED) {
if (first_in_flight) {
// Might have collided, fall back to getdata now :(
std::vector<CInv> invs;
invs.emplace_back(MSG_BLOCK | GetFetchFlags(peer), block_transactions.blockhash);
MakeAndPushMessage(pfrom, NetMsgType::GETDATA, invs);
} else {
RemoveBlockRequest(block_transactions.blockhash, pfrom.GetId());
LogPrint(BCLog::NET, "Peer %d sent us a compact block but it failed to reconstruct, waiting on first download to complete\n", pfrom.GetId());
return;
}
} 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(block_transactions.blockhash, pfrom.GetId()); // 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(block_transactions.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, /*min_pow_checked=*/true);
}
return;
}
void PeerManagerImpl::ProcessMessage(CNode& pfrom, const std::string& msg_type, DataStream& vRecv,
const std::chrono::microseconds time_received,
const std::atomic<bool>& interruptMsgProc)
{
AssertLockHeld(g_msgproc_mutex);
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 >> CNetAddr::V1(addrMe);
if (!pfrom.IsInboundConn())
{
// Overwrites potentially existing services. In contrast to this,
// unvalidated services received via gossip relay in ADDR/ADDRV2
// messages are only ever added but cannot replace existing ones.
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.ToStringAddrPort());
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;
if (greatest_common_version >= WTXID_RELAY_VERSION) {
MakeAndPushMessage(pfrom, 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.
MakeAndPushMessage(pfrom, NetMsgType::SENDADDRV2);
}
pfrom.m_has_all_wanted_services = HasAllDesirableServiceFlags(nServices);
peer->m_their_services = nServices;
pfrom.SetAddrLocal(addrMe);
{
LOCK(pfrom.m_subver_mutex);
pfrom.cleanSubVer = cleanSubVer;
}
peer->m_starting_height = starting_height;
// Only initialize the Peer::TxRelay m_relay_txs data structure if:
// - this isn't an outbound block-relay-only connection, and
// - this isn't an outbound feeler connection, and
// - fRelay=true (the peer wishes to receive transaction announcements)
// or we're offering NODE_BLOOM to this peer. NODE_BLOOM means that
// the peer may turn on transaction relay later.
if (!pfrom.IsBlockOnlyConn() &&
!pfrom.IsFeelerConn() &&
(fRelay || (peer->m_our_services & NODE_BLOOM))) {
auto* const tx_relay = peer->SetTxRelay();
{
LOCK(tx_relay->m_bloom_filter_mutex);
tx_relay->m_relay_txs = fRelay; // set to true after we get the first filter* message
}
if (fRelay) pfrom.m_relays_txs = true;
}
if (greatest_common_version >= WTXID_RELAY_VERSION && m_txreconciliation) {
// Per BIP-330, we announce txreconciliation support if:
// - protocol version per the peer's VERSION message supports WTXID_RELAY;
// - transaction relay is supported per the peer's VERSION message
// - this is not a block-relay-only connection and not a feeler
// - this is not an addr fetch connection;
// - we are not in -blocksonly mode.
const auto* tx_relay = peer->GetTxRelay();
if (tx_relay && WITH_LOCK(tx_relay->m_bloom_filter_mutex, return tx_relay->m_relay_txs) &&
!pfrom.IsAddrFetchConn() && !m_opts.ignore_incoming_txs) {
const uint64_t recon_salt = m_txreconciliation->PreRegisterPeer(pfrom.GetId());
MakeAndPushMessage(pfrom, NetMsgType::SENDTXRCNCL,
TXRECONCILIATION_VERSION, recon_salt);
}
}
MakeAndPushMessage(pfrom, NetMsgType::VERACK);
// 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() && CanServeBlocks(*peer);
m_num_preferred_download_peers += state->fPreferredDownload;
}
// Attempt to initialize address relay for outbound peers and use result
// to decide whether to send GETADDR, so that we don't send it to
// inbound or outbound block-relay-only peers.
bool send_getaddr{false};
if (!pfrom.IsInboundConn()) {
send_getaddr = SetupAddressRelay(pfrom, *peer);
}
if (send_getaddr) {
// 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, so this mechanism is 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.
MakeAndPushMessage(pfrom, 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.ToStringAddrPort();
const auto mapped_as{m_connman.GetMappedAS(pfrom.addr)};
LogPrint(BCLog::NET, "receive version message: %s: version %d, blocks=%d, us=%s, txrelay=%d, peer=%d%s%s\n",
cleanSubVer, pfrom.nVersion,
peer->m_starting_height, addrMe.ToStringAddrPort(), fRelay, pfrom.GetId(),
remoteAddr, (mapped_as ? strprintf(", mapped_as=%d", mapped_as) : ""));
peer->m_time_offset = NodeSeconds{std::chrono::seconds{nTime}} - Now<NodeSeconds>();
if (!pfrom.IsInboundConn()) {
// Don't use timedata samples from inbound peers to make it
// harder for others to create false warnings about our clock being out of sync.
m_outbound_time_offsets.Add(peer->m_time_offset);
m_outbound_time_offsets.WarnIfOutOfSync();
}
// If the peer is old enough to have the old alert system, send it the final alert.
if (greatest_common_version <= 70012) {
const auto finalAlert{ParseHex("60010000000000000000000000ffffff7f00000000ffffff7ffeffff7f01ffffff7f00000000ffffff7f00ffffff7f002f555247454e543a20416c657274206b657920636f6d70726f6d697365642c2075706772616465207265717569726564004630440220653febd6410f470f6bae11cad19c48413becb1ac2c17f908fd0fd53bdc3abd5202206d0e9c96fe88d4a0f01ed9dedae2b6f9e00da94cad0fecaae66ecf689bf71b50")};
MakeAndPushMessage(pfrom, "alert", Span{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;
}
if (msg_type == NetMsgType::VERACK) {
if (pfrom.fSuccessfullyConnected) {
LogPrint(BCLog::NET, "ignoring redundant verack message from peer=%d\n", pfrom.GetId());
return;
}
// Log successful connections unconditionally for outbound, but not for inbound as those
// can be triggered by an attacker at high rate.
if (!pfrom.IsInboundConn() || LogAcceptCategory(BCLog::NET, BCLog::Level::Debug)) {
const auto mapped_as{m_connman.GetMappedAS(pfrom.addr)};
LogPrintf("New %s %s peer connected: version: %d, blocks=%d, peer=%d%s%s\n",
pfrom.ConnectionTypeAsString(),
TransportTypeAsString(pfrom.m_transport->GetInfo().transport_type),
pfrom.nVersion.load(), peer->m_starting_height,
pfrom.GetId(), (fLogIPs ? strprintf(", peeraddr=%s", pfrom.addr.ToStringAddrPort()) : ""),
(mapped_as ? strprintf(", mapped_as=%d", mapped_as) : ""));
}
if (pfrom.GetCommonVersion() >= SHORT_IDS_BLOCKS_VERSION) {
// Tell our peer we are willing to provide version 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
MakeAndPushMessage(pfrom, NetMsgType::SENDCMPCT, /*high_bandwidth=*/false, /*version=*/CMPCTBLOCKS_VERSION);
}
if (m_txreconciliation) {
if (!peer->m_wtxid_relay || !m_txreconciliation->IsPeerRegistered(pfrom.GetId())) {
// We could have optimistically pre-registered/registered the peer. In that case,
// we should forget about the reconciliation state here if this wasn't followed
// by WTXIDRELAY (since WTXIDRELAY can't be announced later).
m_txreconciliation->ForgetPeer(pfrom.GetId());
}
}
if (auto tx_relay = peer->GetTxRelay()) {
// `TxRelay::m_tx_inventory_to_send` must be empty before the
// version handshake is completed as
// `TxRelay::m_next_inv_send_time` is first initialised in
// `SendMessages` after the verack is received. Any transactions
// received during the version handshake would otherwise
// immediately be advertised without random delay, potentially
// leaking the time of arrival to a spy.
Assume(WITH_LOCK(
tx_relay->m_tx_inventory_mutex,
return tx_relay->m_tx_inventory_to_send.empty() &&
tx_relay->m_next_inv_send_time == 0s));
}
pfrom.fSuccessfullyConnected = true;
return;
}
if (msg_type == NetMsgType::SENDHEADERS) {
peer->m_prefers_headers = true;
return;
}
if (msg_type == NetMsgType::SENDCMPCT) {
bool sendcmpct_hb{false};
uint64_t sendcmpct_version{0};
vRecv >> sendcmpct_hb >> sendcmpct_version;
// Only support compact block relay with witnesses
if (sendcmpct_version != CMPCTBLOCKS_VERSION) return;
LOCK(cs_main);
CNodeState* nodestate = State(pfrom.GetId());
nodestate->m_provides_cmpctblocks = true;
nodestate->m_requested_hb_cmpctblocks = sendcmpct_hb;
// 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 = sendcmpct_hb;
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;
}
// Received from a peer demonstrating readiness to announce transactions via reconciliations.
// This feature negotiation must happen between VERSION and VERACK to avoid relay problems
// from switching announcement protocols after the connection is up.
if (msg_type == NetMsgType::SENDTXRCNCL) {
if (!m_txreconciliation) {
LogPrintLevel(BCLog::NET, BCLog::Level::Debug, "sendtxrcncl from peer=%d ignored, as our node does not have txreconciliation enabled\n", pfrom.GetId());
return;
}
if (pfrom.fSuccessfullyConnected) {
LogPrintLevel(BCLog::NET, BCLog::Level::Debug, "sendtxrcncl received after verack from peer=%d; disconnecting\n", pfrom.GetId());
pfrom.fDisconnect = true;
return;
}
// Peer must not offer us reconciliations if we specified no tx relay support in VERSION.
if (RejectIncomingTxs(pfrom)) {
LogPrintLevel(BCLog::NET, BCLog::Level::Debug, "sendtxrcncl received from peer=%d to which we indicated no tx relay; disconnecting\n", pfrom.GetId());
pfrom.fDisconnect = true;
return;
}
// Peer must not offer us reconciliations if they specified no tx relay support in VERSION.
// This flag might also be false in other cases, but the RejectIncomingTxs check above
// eliminates them, so that this flag fully represents what we are looking for.
const auto* tx_relay = peer->GetTxRelay();
if (!tx_relay || !WITH_LOCK(tx_relay->m_bloom_filter_mutex, return tx_relay->m_relay_txs)) {
LogPrintLevel(BCLog::NET, BCLog::Level::Debug, "sendtxrcncl received from peer=%d which indicated no tx relay to us; disconnecting\n", pfrom.GetId());
pfrom.fDisconnect = true;
return;
}
uint32_t peer_txreconcl_version;
uint64_t remote_salt;
vRecv >> peer_txreconcl_version >> remote_salt;
const ReconciliationRegisterResult result = m_txreconciliation->RegisterPeer(pfrom.GetId(), pfrom.IsInboundConn(),
peer_txreconcl_version, remote_salt);
switch (result) {
case ReconciliationRegisterResult::NOT_FOUND:
LogPrintLevel(BCLog::NET, BCLog::Level::Debug, "Ignore unexpected txreconciliation signal from peer=%d\n", pfrom.GetId());
break;
case ReconciliationRegisterResult::SUCCESS:
break;
case ReconciliationRegisterResult::ALREADY_REGISTERED:
LogPrintLevel(BCLog::NET, BCLog::Level::Debug, "txreconciliation protocol violation from peer=%d (sendtxrcncl received from already registered peer); disconnecting\n", pfrom.GetId());
pfrom.fDisconnect = true;
return;
case ReconciliationRegisterResult::PROTOCOL_VIOLATION:
LogPrintLevel(BCLog::NET, BCLog::Level::Debug, "txreconciliation protocol violation from peer=%d; disconnecting\n", pfrom.GetId());
pfrom.fDisconnect = true;
return;
}
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) {
const auto ser_params{
msg_type == NetMsgType::ADDRV2 ?
// Set V2 param so that the CNetAddr and CAddress
// unserialize methods know that an address in v2 format is coming.
CAddress::V2_NETWORK :
CAddress::V1_NETWORK,
};
std::vector<CAddress> vAddr;
vRecv >> ser_params(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(*peer, 20, strprintf("%s message size = %u", msg_type, vAddr.size()));
return;
}
// Store the new addresses
std::vector<CAddress> vAddrOk;
const auto current_a_time{Now<NodeSeconds>()};
// 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 = Ticks<SecondsDouble>(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(), m_rng);
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 <= NodeSeconds{100000000s} || addr.nTime > current_a_time + 10min) {
addr.nTime = current_a_time - 5 * 24h;
}
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;
const bool reachable{g_reachable_nets.Contains(addr)};
if (addr.nTime > current_a_time - 10min && !peer->m_getaddr_sent && vAddr.size() <= 10 && addr.IsRoutable()) {
// Relay to a limited number of other nodes
RelayAddress(pfrom.GetId(), addr, reachable);
}
// Do not store addresses outside our network
if (reachable) {
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, 2h);
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(*peer, 20, strprintf("inv message size = %u", vInv.size()));
return;
}
const bool reject_tx_invs{RejectIncomingTxs(pfrom)};
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 && !m_chainman.m_blockman.LoadingBlocks() && !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 may be for a re-org, or because we haven't
// completed initial headers sync. 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, /*include_reconsiderable=*/true);
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.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) {
// If we haven't started initial headers-sync with this peer, then
// consider sending a getheaders now. On initial startup, there's a
// reliability vs bandwidth tradeoff, where we are only trying to do
// initial headers sync with one peer at a time, with a long
// timeout (at which point, if the sync hasn't completed, we will
// disconnect the peer and then choose another). In the meantime,
// as new blocks are found, we are willing to add one new peer per
// block to sync with as well, to sync quicker in the case where
// our initial peer is unresponsive (but less bandwidth than we'd
// use if we turned on sync with all peers).
CNodeState& state{*Assert(State(pfrom.GetId()))};
if (state.fSyncStarted || (!peer->m_inv_triggered_getheaders_before_sync && *best_block != m_last_block_inv_triggering_headers_sync)) {
if (MaybeSendGetHeaders(pfrom, GetLocator(m_chainman.m_best_header), *peer)) {
LogPrint(BCLog::NET, "getheaders (%d) %s to peer=%d\n",
m_chainman.m_best_header->nHeight, best_block->ToString(),
pfrom.GetId());
}
if (!state.fSyncStarted) {
peer->m_inv_triggered_getheaders_before_sync = true;
// Update the last block hash that triggered a new headers
// sync, so that we don't turn on headers sync with more
// than 1 new peer every new block.
m_last_block_inv_triggering_headers_sync = *best_block;
}
}
}
return;
}
if (msg_type == NetMsgType::GETDATA) {
std::vector<CInv> vInv;
vRecv >> vInv;
if (vInv.size() > MAX_INV_SZ)
{
Misbehaving(*peer, 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 (m_chainman.m_blockman.IsPruneMode() && (!(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, *peer, *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;
const bool ret{m_chainman.m_blockman.ReadBlockFromDisk(block, *pindex)};
assert(ret);
SendBlockTransactions(pfrom, *peer, 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{MSG_WITNESS_BLOCK, 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;
}
if (m_chainman.m_blockman.LoadingBlocks()) {
LogPrint(BCLog::NET, "Ignoring getheaders from peer=%d while importing/reindexing\n", pfrom.GetId());
return;
}
LOCK(cs_main);
// Note that if we were to be on a chain that forks from the checkpointed
// chain, then serving those headers to a peer that has seen the
// checkpointed chain would cause that peer to disconnect us. Requiring
// that our chainwork exceed the minimum chain work is a protection against
// being fed a bogus chain when we started up for the first time and
// getting partitioned off the honest network for serving that chain to
// others.
if (m_chainman.ActiveTip() == nullptr ||
(m_chainman.ActiveTip()->nChainWork < m_chainman.MinimumChainWork() && !pfrom.HasPermission(NetPermissionFlags::Download))) {
LogPrint(BCLog::NET, "Ignoring getheaders from peer=%d because active chain has too little work; sending empty response\n", pfrom.GetId());
// Just respond with an empty headers message, to tell the peer to
// go away but not treat us as unresponsive.
MakeAndPushMessage(pfrom, NetMsgType::HEADERS, std::vector<CBlockHeader>());
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.emplace_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();
MakeAndPushMessage(pfrom, NetMsgType::HEADERS, TX_WITH_WITNESS(vHeaders));
return;
}
if (msg_type == NetMsgType::TX) {
if (RejectIncomingTxs(pfrom)) {
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.IsInitialBlockDownload()) return;
CTransactionRef ptx;
vRecv >> TX_WITH_WITNESS(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);
LOCK(cs_main);
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), /*include_reconsiderable=*/true)) {
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 (wtxid=%s) from forcerelay peer=%d\n",
tx.GetHash().ToString(), tx.GetWitnessHash().ToString(), pfrom.GetId());
} else {
LogPrintf("Force relaying tx %s (wtxid=%s) from peer=%d\n",
tx.GetHash().ToString(), tx.GetWitnessHash().ToString(), pfrom.GetId());
RelayTransaction(tx.GetHash(), tx.GetWitnessHash());
}
}
if (m_recent_rejects_reconsiderable.contains(wtxid)) {
// When a transaction is already in m_recent_rejects_reconsiderable, we shouldn't submit
// it by itself again. However, look for a matching child in the orphanage, as it is
// possible that they succeed as a package.
LogPrint(BCLog::TXPACKAGES, "found tx %s (wtxid=%s) in reconsiderable rejects, looking for child in orphanage\n",
txid.ToString(), wtxid.ToString());
if (auto package_to_validate{Find1P1CPackage(ptx, pfrom.GetId())}) {
const auto package_result{ProcessNewPackage(m_chainman.ActiveChainstate(), m_mempool, package_to_validate->m_txns, /*test_accept=*/false, /*client_maxfeerate=*/std::nullopt)};
LogDebug(BCLog::TXPACKAGES, "package evaluation for %s: %s\n", package_to_validate->ToString(),
package_result.m_state.IsValid() ? "package accepted" : "package rejected");
ProcessPackageResult(package_to_validate.value(), package_result);
}
}
// If a tx is detected by m_recent_rejects it is 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.
return;
}
const MempoolAcceptResult result = m_chainman.ProcessTransaction(ptx);
const TxValidationState& state = result.m_state;
if (result.m_result_type == MempoolAcceptResult::ResultType::VALID) {
ProcessValidTx(pfrom.GetId(), ptx, result.m_replaced_transactions);
pfrom.m_last_tx_time = GetTime<std::chrono::seconds>();
}
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());
// Distinguish between parents in m_recent_rejects and m_recent_rejects_reconsiderable.
// We can tolerate having up to 1 parent in m_recent_rejects_reconsiderable since we
// submit 1p1c packages. However, fail immediately if any are in m_recent_rejects.
std::optional<uint256> rejected_parent_reconsiderable;
for (const uint256& parent_txid : unique_parents) {
if (m_recent_rejects.contains(parent_txid)) {
fRejectedParents = true;
break;
} else if (m_recent_rejects_reconsiderable.contains(parent_txid) && !m_mempool.exists(GenTxid::Txid(parent_txid))) {
// More than 1 parent in m_recent_rejects_reconsiderable: 1p1c will not be
// sufficient to accept this package, so just give up here.
if (rejected_parent_reconsiderable.has_value()) {
fRejectedParents = true;
break;
}
rejected_parent_reconsiderable = parent_txid;
}
}
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);
// Exclude m_recent_rejects_reconsiderable: the missing parent may have been
// previously rejected for being too low feerate. This orphan might CPFP it.
if (!AlreadyHaveTx(gtxid, /*include_reconsiderable=*/false)) 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)
m_orphanage.LimitOrphans(m_opts.max_orphan_txs, m_rng);
} else {
LogPrint(BCLog::MEMPOOL, "not keeping orphan with rejected parents %s (wtxid=%s)\n",
tx.GetHash().ToString(),
tx.GetWitnessHash().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().ToUint256());
m_recent_rejects.insert(tx.GetWitnessHash().ToUint256());
m_txrequest.ForgetTxHash(tx.GetHash());
m_txrequest.ForgetTxHash(tx.GetWitnessHash());
}
}
if (state.IsInvalid()) {
ProcessInvalidTx(pfrom.GetId(), ptx, state, /*maybe_add_extra_compact_tx=*/true);
}
// When a transaction fails for TX_RECONSIDERABLE, look for a matching child in the
// orphanage, as it is possible that they succeed as a package.
if (state.GetResult() == TxValidationResult::TX_RECONSIDERABLE) {
LogPrint(BCLog::TXPACKAGES, "tx %s (wtxid=%s) failed but reconsiderable, looking for child in orphanage\n",
txid.ToString(), wtxid.ToString());
if (auto package_to_validate{Find1P1CPackage(ptx, pfrom.GetId())}) {
const auto package_result{ProcessNewPackage(m_chainman.ActiveChainstate(), m_mempool, package_to_validate->m_txns, /*test_accept=*/false, /*client_maxfeerate=*/std::nullopt)};
LogDebug(BCLog::TXPACKAGES, "package evaluation for %s: %s\n", package_to_validate->ToString(),
package_result.m_state.IsValid() ? "package accepted" : "package rejected");
ProcessPackageResult(package_to_validate.value(), package_result);
}
}
return;
}
if (msg_type == NetMsgType::CMPCTBLOCK)
{
// Ignore cmpctblock received while importing
if (m_chainman.m_blockman.LoadingBlocks()) {
LogPrint(BCLog::NET, "Unexpected cmpctblock message received from peer %d\n", pfrom.GetId());
return;
}
CBlockHeaderAndShortTxIDs cmpctblock;
vRecv >> cmpctblock;
bool received_new_header = false;
const auto blockhash = cmpctblock.header.GetHash();
{
LOCK(cs_main);
const CBlockIndex* prev_block = m_chainman.m_blockman.LookupBlockIndex(cmpctblock.header.hashPrevBlock);
if (!prev_block) {
// Doesn't connect (or is genesis), instead of DoSing in AcceptBlockHeader, request deeper headers
if (!m_chainman.IsInitialBlockDownload()) {
MaybeSendGetHeaders(pfrom, GetLocator(m_chainman.m_best_header), *peer);
}
return;
} else if (prev_block->nChainWork + CalculateClaimedHeadersWork({cmpctblock.header}) < GetAntiDoSWorkThreshold()) {
// If we get a low-work header in a compact block, we can ignore it.
LogPrint(BCLog::NET, "Ignoring low-work compact block from peer %d\n", pfrom.GetId());
return;
}
if (!m_chainman.m_blockman.LookupBlockIndex(blockhash)) {
received_new_header = true;
}
}
const CBlockIndex *pindex = nullptr;
BlockValidationState state;
if (!m_chainman.ProcessNewBlockHeaders({cmpctblock.header}, /*min_pow_checked=*/true, state, &pindex)) {
if (state.IsInvalid()) {
MaybePunishNodeForBlock(pfrom.GetId(), state, /*via_compact_block=*/true, "invalid header via cmpctblock");
return;
}
}
if (received_new_header) {
LogInfo("Saw new cmpctblock header hash=%s peer=%d\n",
blockhash.ToString(), pfrom.GetId());
}
bool fProcessBLOCKTXN = false;
// 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;
{
LOCK(cs_main);
// 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();
}
if (pindex->nStatus & BLOCK_HAVE_DATA) // Nothing to do here
return;
auto range_flight = mapBlocksInFlight.equal_range(pindex->GetBlockHash());
size_t already_in_flight = std::distance(range_flight.first, range_flight.second);
bool requested_block_from_this_peer{false};
// Multimap ensures ordering of outstanding requests. It's either empty or first in line.
bool first_in_flight = already_in_flight == 0 || (range_flight.first->second.first == pfrom.GetId());
while (range_flight.first != range_flight.second) {
if (range_flight.first->second.first == pfrom.GetId()) {
requested_block_from_this_peer = true;
break;
}
range_flight.first++;
}
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 (requested_block_from_this_peer) {
// 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(*peer), blockhash);
MakeAndPushMessage(pfrom, NetMsgType::GETDATA, vInv);
}
return;
}
// If we're not close to tip yet, give up and let parallel block fetch work its magic
if (!already_in_flight && !CanDirectFetch()) {
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 ((already_in_flight < MAX_CMPCTBLOCKS_INFLIGHT_PER_BLOCK && nodestate->vBlocksInFlight.size() < MAX_BLOCKS_IN_TRANSIT_PER_PEER) ||
requested_block_from_this_peer) {
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(), pfrom.GetId()); // Reset in-flight state in case Misbehaving does not result in a disconnect
Misbehaving(*peer, 100, "invalid compact block");
return;
} else if (status == READ_STATUS_FAILED) {
if (first_in_flight) {
// Duplicate txindexes, the block is now in-flight, so just request it
std::vector<CInv> vInv(1);
vInv[0] = CInv(MSG_BLOCK | GetFetchFlags(*peer), blockhash);
MakeAndPushMessage(pfrom, NetMsgType::GETDATA, vInv);
} else {
// Give up for this peer and wait for other peer(s)
RemoveBlockRequest(pindex->GetBlockHash(), pfrom.GetId());
}
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()) {
fProcessBLOCKTXN = true;
} else if (first_in_flight) {
// We will try to round-trip any compact blocks we get on failure,
// as long as it's first...
req.blockhash = pindex->GetBlockHash();
MakeAndPushMessage(pfrom, NetMsgType::GETBLOCKTXN, req);
} else if (pfrom.m_bip152_highbandwidth_to &&
(!pfrom.IsInboundConn() ||
IsBlockRequestedFromOutbound(blockhash) ||
already_in_flight < MAX_CMPCTBLOCKS_INFLIGHT_PER_BLOCK - 1)) {
// ... or it's a hb relay peer and:
// - peer is outbound, or
// - we already have an outbound attempt in flight(so we'll take what we can get), or
// - it's not the final parallel download slot (which we may reserve for first outbound)
req.blockhash = pindex->GetBlockHash();
MakeAndPushMessage(pfrom, NetMsgType::GETBLOCKTXN, req);
} else {
// Give up for this peer and wait for other peer(s)
RemoveBlockRequest(pindex->GetBlockHash(), pfrom.GetId());
}
} 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 (requested_block_from_this_peer) {
// 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(*peer), blockhash);
MakeAndPushMessage(pfrom, 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) {
BlockTransactions txn;
txn.blockhash = blockhash;
return ProcessCompactBlockTxns(pfrom, *peer, txn);
}
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 the minimum chain work), 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, /*min_pow_checked=*/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(), std::nullopt);
}
}
return;
}
if (msg_type == NetMsgType::BLOCKTXN)
{
// Ignore blocktxn received while importing
if (m_chainman.m_blockman.LoadingBlocks()) {
LogPrint(BCLog::NET, "Unexpected blocktxn message received from peer %d\n", pfrom.GetId());
return;
}
BlockTransactions resp;
vRecv >> resp;
return ProcessCompactBlockTxns(pfrom, *peer, resp);
}
if (msg_type == NetMsgType::HEADERS)
{
// Ignore headers received while importing
if (m_chainman.m_blockman.LoadingBlocks()) {
LogPrint(BCLog::NET, "Unexpected headers message received from peer %d\n", pfrom.GetId());
return;
}
// Assume that this is in response to any outstanding getheaders
// request we may have sent, and clear out the time of our last request
peer->m_last_getheaders_timestamp = {};
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(*peer, 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.
}
ProcessHeadersMessage(pfrom, *peer, std::move(headers), /*via_compact_block=*/false);
// Check if the headers presync progress needs to be reported to validation.
// This needs to be done without holding the m_headers_presync_mutex lock.
if (m_headers_presync_should_signal.exchange(false)) {
HeadersPresyncStats stats;
{
LOCK(m_headers_presync_mutex);
auto it = m_headers_presync_stats.find(m_headers_presync_bestpeer);
if (it != m_headers_presync_stats.end()) stats = it->second;
}
if (stats.second) {
m_chainman.ReportHeadersPresync(stats.first, stats.second->first, stats.second->second);
}
}
return;
}
if (msg_type == NetMsgType::BLOCK)
{
// Ignore block received while importing
if (m_chainman.m_blockman.LoadingBlocks()) {
LogPrint(BCLog::NET, "Unexpected block message received from peer %d\n", pfrom.GetId());
return;
}
std::shared_ptr<CBlock> pblock = std::make_shared<CBlock>();
vRecv >> TX_WITH_WITNESS(*pblock);
LogPrint(BCLog::NET, "received block %s peer=%d\n", pblock->GetHash().ToString(), pfrom.GetId());
const CBlockIndex* prev_block{WITH_LOCK(m_chainman.GetMutex(), return m_chainman.m_blockman.LookupBlockIndex(pblock->hashPrevBlock))};
// Check for possible mutation if it connects to something we know so we can check for DEPLOYMENT_SEGWIT being active
if (prev_block && IsBlockMutated(/*block=*/*pblock,
/*check_witness_root=*/DeploymentActiveAfter(prev_block, m_chainman, Consensus::DEPLOYMENT_SEGWIT))) {
LogDebug(BCLog::NET, "Received mutated block from peer=%d\n", peer->m_id);
Misbehaving(*peer, 100, "mutated block");
WITH_LOCK(cs_main, RemoveBlockRequest(pblock->GetHash(), peer->m_id));
return;
}
bool forceProcessing = false;
const uint256 hash(pblock->GetHash());
bool min_pow_checked = false;
{
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, pfrom.GetId());
// 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));
// Check claimed work on this block against our anti-dos thresholds.
if (prev_block && prev_block->nChainWork + CalculateClaimedHeadersWork({pblock->GetBlockHeader()}) >= GetAntiDoSWorkThreshold()) {
min_pow_checked = true;
}
}
ProcessBlock(pfrom, pblock, forceProcessing, min_pow_checked);
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);
}
for (const CAddress &addr : vAddr) {
PushAddress(*peer, addr);
}
return;
}
if (msg_type == NetMsgType::MEMPOOL) {
// Only process received mempool messages if we advertise NODE_BLOOM
// or if the peer has mempool permissions.
if (!(peer->m_our_services & 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 (auto tx_relay = peer->GetTxRelay(); tx_relay != nullptr) {
LOCK(tx_relay->m_tx_inventory_mutex);
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.
MakeAndPushMessage(pfrom, 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 (!(peer->m_our_services & 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(*peer, 100, "too-large bloom filter");
} else if (auto tx_relay = peer->GetTxRelay(); tx_relay != nullptr) {
{
LOCK(tx_relay->m_bloom_filter_mutex);
tx_relay->m_bloom_filter.reset(new CBloomFilter(filter));
tx_relay->m_relay_txs = true;
}
pfrom.m_bloom_filter_loaded = true;
pfrom.m_relays_txs = true;
}
return;
}
if (msg_type == NetMsgType::FILTERADD) {
if (!(peer->m_our_services & 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 > MAX_SCRIPT_ELEMENT_SIZE 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 (auto tx_relay = peer->GetTxRelay(); tx_relay != nullptr) {
LOCK(tx_relay->m_bloom_filter_mutex);
if (tx_relay->m_bloom_filter) {
tx_relay->m_bloom_filter->insert(vData);
} else {
bad = true;
}
}
if (bad) {
Misbehaving(*peer, 100, "bad filteradd message");
}
return;
}
if (msg_type == NetMsgType::FILTERCLEAR) {
if (!(peer->m_our_services & NODE_BLOOM)) {
LogPrint(BCLog::NET, "filterclear received despite not offering bloom services from peer=%d; disconnecting\n", pfrom.GetId());
pfrom.fDisconnect = true;
return;
}
auto tx_relay = peer->GetTxRelay();
if (!tx_relay) return;
{
LOCK(tx_relay->m_bloom_filter_mutex);
tx_relay->m_bloom_filter = nullptr;
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 (auto tx_relay = peer->GetTxRelay(); tx_relay != nullptr) {
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, *peer, vRecv);
return;
}
if (msg_type == NetMsgType::GETCFHEADERS) {
ProcessGetCFHeaders(pfrom, *peer, vRecv);
return;
}
if (msg_type == NetMsgType::GETCFCHECKPT) {
ProcessGetCFCheckPt(pfrom, *peer, 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)
{
AssertLockHeld(g_msgproc_mutex);
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);
}
}
const bool processed_orphan = ProcessOrphanTx(*peer);
if (pfrom->fDisconnect)
return false;
if (processed_orphan) return true;
// 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;
}
// Don't bother if send buffer is too full to respond anyway
if (pfrom->fPauseSend) return false;
auto poll_result{pfrom->PollMessage()};
if (!poll_result) {
// No message to process
return false;
}
CNetMessage& msg{poll_result->first};
bool fMoreWork = poll_result->second;
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 (m_opts.capture_messages) {
CaptureMessage(pfrom->addr, msg.m_type, MakeUCharSpan(msg.m_recv), /*is_incoming=*/true);
}
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;
}
// Does this peer has an orphan ready to reconsider?
// (Note: we may have provided a parent for an orphan provided
// by another peer that was already processed; in that case,
// the extra work may not be noticed, possibly resulting in an
// unnecessary 100ms delay)
if (m_orphanage.HaveTxToReconsider(peer->m_id)) 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, Peer& peer, std::chrono::seconds time_in_seconds)
{
AssertLockHeld(cs_main);
CNodeState &state = *State(pto.GetId());
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);
// Here, we assume that the getheaders message goes out,
// because it'll either go out or be skipped because of a
// getheaders in-flight already, in which case the peer should
// still respond to us with a sufficiently high work chain tip.
MaybeSendGetHeaders(pto,
GetLocator(state.m_chain_sync.m_work_header->pprev),
peer);
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());
state.m_chain_sync.m_sent_getheaders = true;
// 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->vBlocksInFlight.empty())) {
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->vBlocksInFlight.size());
}
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)
// Protect peers from eviction if we don't have another connection
// to their network, counting both outbound-full-relay and manual peers.
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, m_connman.GetNodesMutex()) {
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 this is the only connection on a particular network that is
// OUTBOUND_FULL_RELAY or MANUAL, protect it.
if (!m_connman.MultipleManualOrFullOutboundConns(pnode->addr.GetNetwork())) 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.vBlocksInFlight.empty()) {
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.vBlocksInFlight.size());
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 (!m_chainman.m_blockman.LoadingBlocks() && 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;
}
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;
MakeAndPushMessage(node_to, NetMsgType::PING, nonce);
} else {
// Peer is too old to support ping command with nonce, pong will never arrive.
peer.m_ping_nonce_sent = 0;
MakeAndPushMessage(node_to, 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.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<CService> local_service = GetLocalAddrForPeer(node)) {
CAddress local_addr{*local_service, peer.m_our_services, Now<NodeSeconds>()};
PushAddress(peer, local_addr);
}
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) EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex) {
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;
if (peer.m_wants_addrv2) {
MakeAndPushMessage(node, NetMsgType::ADDRV2, CAddress::V2_NETWORK(peer.m_addrs_to_send));
} else {
MakeAndPushMessage(node, NetMsgType::ADDR, CAddress::V1_NETWORK(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::MaybeSendSendHeaders(CNode& node, Peer& peer)
{
// Delay sending SENDHEADERS (BIP 130) until we're done with an
// initial-headers-sync with this peer. Receiving headers announcements for
// new blocks while trying to sync their headers chain is problematic,
// because of the state tracking done.
if (!peer.m_sent_sendheaders && node.GetCommonVersion() >= SENDHEADERS_VERSION) {
LOCK(cs_main);
CNodeState &state = *State(node.GetId());
if (state.pindexBestKnownBlock != nullptr &&
state.pindexBestKnownBlock->nChainWork > m_chainman.MinimumChainWork()) {
// 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)
MakeAndPushMessage(node, NetMsgType::SENDHEADERS);
peer.m_sent_sendheaders = true;
}
}
}
void PeerManagerImpl::MaybeSendFeefilter(CNode& pto, Peer& peer, std::chrono::microseconds current_time)
{
if (m_opts.ignore_incoming_txs) return;
if (pto.GetCommonVersion() < FEEFILTER_VERSION) return;
// peers with the forcerelay permission should not filter txs to us
if (pto.HasPermission(NetPermissionFlags::ForceRelay)) return;
// Don't send feefilter messages to outbound block-relay-only peers since they should never announce
// transactions to us, regardless of feefilter state.
if (pto.IsBlockOnlyConn()) return;
CAmount currentFilter = m_mempool.GetMinFee().GetFeePerK();
if (m_chainman.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{m_fee_filter_rounder.round(MAX_MONEY)};
if (peer.m_fee_filter_sent == MAX_FILTER) {
// Send the current filter if we sent MAX_FILTER previously
// and made it out of IBD.
peer.m_next_send_feefilter = 0us;
}
}
if (current_time > peer.m_next_send_feefilter) {
CAmount filterToSend = m_fee_filter_rounder.round(currentFilter);
// We always have a fee filter of at least the min relay fee
filterToSend = std::max(filterToSend, m_mempool.m_min_relay_feerate.GetFeePerK());
if (filterToSend != peer.m_fee_filter_sent) {
MakeAndPushMessage(pto, NetMsgType::FEEFILTER, filterToSend);
peer.m_fee_filter_sent = filterToSend;
}
peer.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_next_send_feefilter &&
(currentFilter < 3 * peer.m_fee_filter_sent / 4 || currentFilter > 4 * peer.m_fee_filter_sent / 3)) {
peer.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);
}
};
} // namespace
bool PeerManagerImpl::RejectIncomingTxs(const CNode& peer) const
{
// block-relay-only peers may never send txs to us
if (peer.IsBlockOnlyConn()) return true;
if (peer.IsFeelerConn()) return true;
// In -blocksonly mode, peers need the 'relay' permission to send txs to us
if (m_opts.ignore_incoming_txs && !peer.HasPermission(NetPermissionFlags::Relay)) return true;
return false;
}
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)) {
// During version message processing (non-block-relay-only outbound peers)
// or on first addr-related message we have received (inbound peers), initialize
// m_addr_known.
peer.m_addr_known = std::make_unique<CRollingBloomFilter>(5000, 0.001);
}
return true;
}
bool PeerManagerImpl::SendMessages(CNode* pto)
{
AssertLockHeld(g_msgproc_mutex);
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;
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);
MaybeSendSendHeaders(*pto, *peer);
{
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();
}
// Determine whether we might try initial headers sync or parallel
// block download from this peer -- this mostly affects behavior while
// in IBD (once out of IBD, we sync from all peers).
bool sync_blocks_and_headers_from_peer = false;
if (state.fPreferredDownload) {
sync_blocks_and_headers_from_peer = true;
} else if (CanServeBlocks(*peer) && !pto->IsAddrFetchConn()) {
// Typically this is an inbound peer. If we don't have any outbound
// peers, or if we aren't downloading any blocks from such peers,
// then allow block downloads from this peer, too.
// We prefer downloading blocks from outbound peers to avoid
// putting undue load on (say) some home user who is just making
// outbound connections to the network, but if our only source of
// the latest blocks is from an inbound peer, we have to be sure to
// eventually download it (and not just wait indefinitely for an
// outbound peer to have it).
if (m_num_preferred_download_peers == 0 || mapBlocksInFlight.empty()) {
sync_blocks_and_headers_from_peer = true;
}
}
if (!state.fSyncStarted && CanServeBlocks(*peer) && !m_chainman.m_blockman.LoadingBlocks()) {
// Only actively request headers from a single peer, unless we're close to today.
if ((nSyncStarted == 0 && sync_blocks_and_headers_from_peer) || m_chainman.m_best_header->Time() > NodeClock::now() - 24h) {
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;
if (MaybeSendGetHeaders(*pto, GetLocator(pindexStart), *peer)) {
LogPrint(BCLog::NET, "initial getheaders (%d) to peer=%d (startheight:%d)\n", pindexStart->nHeight, pto->GetId(), peer->m_starting_height);
state.fSyncStarted = true;
peer->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} *
Ticks<std::chrono::seconds>(NodeClock::now() - m_chainman.m_best_header->Time()) / consensusParams.nPowTargetSpacing
);
nSyncStarted++;
}
}
}
//
// Try sending block announcements via headers
//
{
// If we have no more 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 = ((!peer->m_prefers_headers &&
(!state.m_requested_hb_cmpctblocks || 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.emplace_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.emplace_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.m_requested_hb_cmpctblocks) {
// 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());
std::optional<CSerializedNetMsg> cached_cmpctblock_msg;
{
LOCK(m_most_recent_block_mutex);
if (m_most_recent_block_hash == pBestIndex->GetBlockHash()) {
cached_cmpctblock_msg = NetMsg::Make(NetMsgType::CMPCTBLOCK, *m_most_recent_compact_block);
}
}
if (cached_cmpctblock_msg.has_value()) {
PushMessage(*pto, std::move(cached_cmpctblock_msg.value()));
} else {
CBlock block;
const bool ret{m_chainman.m_blockman.ReadBlockFromDisk(block, *pBestIndex)};
assert(ret);
CBlockHeaderAndShortTxIDs cmpctblock{block};
MakeAndPushMessage(*pto, NetMsgType::CMPCTBLOCK, cmpctblock);
}
state.pindexBestHeaderSent = pBestIndex;
} else if (peer->m_prefers_headers) {
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());
}
MakeAndPushMessage(*pto, NetMsgType::HEADERS, TX_WITH_WITNESS(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_TARGET));
// Add blocks
for (const uint256& hash : peer->m_blocks_for_inv_relay) {
vInv.emplace_back(MSG_BLOCK, hash);
if (vInv.size() == MAX_INV_SZ) {
MakeAndPushMessage(*pto, NetMsgType::INV, vInv);
vInv.clear();
}
}
peer->m_blocks_for_inv_relay.clear();
}
if (auto tx_relay = peer->GetTxRelay(); tx_relay != nullptr) {
LOCK(tx_relay->m_tx_inventory_mutex);
// Check whether periodic sends should happen
bool fSendTrickle = pto->HasPermission(NetPermissionFlags::NoBan);
if (tx_relay->m_next_inv_send_time < current_time) {
fSendTrickle = true;
if (pto->IsInboundConn()) {
tx_relay->m_next_inv_send_time = NextInvToInbounds(current_time, INBOUND_INVENTORY_BROADCAST_INTERVAL);
} else {
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(tx_relay->m_bloom_filter_mutex);
if (!tx_relay->m_relay_txs) tx_relay->m_tx_inventory_to_send.clear();
}
// Respond to BIP35 mempool requests
if (fSendTrickle && tx_relay->m_send_mempool) {
auto vtxinfo = m_mempool.infoAll();
tx_relay->m_send_mempool = false;
const CFeeRate filterrate{tx_relay->m_fee_filter_received.load()};
LOCK(tx_relay->m_bloom_filter_mutex);
for (const auto& txinfo : vtxinfo) {
CInv inv{
peer->m_wtxid_relay ? MSG_WTX : MSG_TX,
peer->m_wtxid_relay ?
txinfo.tx->GetWitnessHash().ToUint256() :
txinfo.tx->GetHash().ToUint256(),
};
tx_relay->m_tx_inventory_to_send.erase(inv.hash);
// Don't send transactions that peers will not put into their mempool
if (txinfo.fee < filterrate.GetFee(txinfo.vsize)) {
continue;
}
if (tx_relay->m_bloom_filter) {
if (!tx_relay->m_bloom_filter->IsRelevantAndUpdate(*txinfo.tx)) continue;
}
tx_relay->m_tx_inventory_known_filter.insert(inv.hash);
vInv.push_back(inv);
if (vInv.size() == MAX_INV_SZ) {
MakeAndPushMessage(*pto, NetMsgType::INV, vInv);
vInv.clear();
}
}
}
// Determine transactions to relay
if (fSendTrickle) {
// Produce a vector with all candidates for sending
std::vector<std::set<uint256>::iterator> vInvTx;
vInvTx.reserve(tx_relay->m_tx_inventory_to_send.size());
for (std::set<uint256>::iterator it = tx_relay->m_tx_inventory_to_send.begin(); it != tx_relay->m_tx_inventory_to_send.end(); it++) {
vInvTx.push_back(it);
}
const CFeeRate filterrate{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(tx_relay->m_bloom_filter_mutex);
size_t broadcast_max{INVENTORY_BROADCAST_TARGET + (tx_relay->m_tx_inventory_to_send.size()/1000)*5};
broadcast_max = std::min<size_t>(INVENTORY_BROADCAST_MAX, broadcast_max);
while (!vInvTx.empty() && nRelayedTransactions < 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
tx_relay->m_tx_inventory_to_send.erase(it);
// Check if not in the filter already
if (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;
}
// Peer told you to not send transactions at that feerate? Don't bother sending it.
if (txinfo.fee < filterrate.GetFee(txinfo.vsize)) {
continue;
}
if (tx_relay->m_bloom_filter && !tx_relay->m_bloom_filter->IsRelevantAndUpdate(*txinfo.tx)) continue;
// Send
vInv.push_back(inv);
nRelayedTransactions++;
if (vInv.size() == MAX_INV_SZ) {
MakeAndPushMessage(*pto, NetMsgType::INV, vInv);
vInv.clear();
}
tx_relay->m_tx_inventory_known_filter.insert(hash);
}
// Ensure we'll respond to GETDATA requests for anything we've just announced
LOCK(m_mempool.cs);
tx_relay->m_last_inv_sequence = m_mempool.GetSequence();
}
}
if (!vInv.empty())
MakeAndPushMessage(*pto, NetMsgType::INV, vInv);
// Detect whether we're stalling
auto stalling_timeout = m_block_stalling_timeout.load();
if (state.m_stalling_since.count() && state.m_stalling_since < current_time - 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%s is stalling block download, disconnecting\n", pto->GetId(), fLogIPs ? strprintf(" peeraddr=%s", pto->addr.ToStringAddrPort()) : "");
pto->fDisconnect = true;
// Increase timeout for the next peer so that we don't disconnect multiple peers if our own
// bandwidth is insufficient.
const auto new_timeout = std::min(2 * stalling_timeout, BLOCK_STALLING_TIMEOUT_MAX);
if (stalling_timeout != new_timeout && m_block_stalling_timeout.compare_exchange_strong(stalling_timeout, new_timeout)) {
LogPrint(BCLog::NET, "Increased stalling timeout temporarily to %d seconds\n", count_seconds(new_timeout));
}
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%s, disconnecting\n", queuedBlock.pindex->GetBlockHash().ToString(), pto->GetId(), fLogIPs ? strprintf(" peeraddr=%s", pto->addr.ToStringAddrPort()) : "");
pto->fDisconnect = true;
return true;
}
}
// Check for headers sync timeouts
if (state.fSyncStarted && peer->m_headers_sync_timeout < std::chrono::microseconds::max()) {
// Detect whether this is a stalling initial-headers-sync peer
if (m_chainman.m_best_header->Time() <= NodeClock::now() - 24h) {
if (current_time > peer->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%s, disconnecting\n", pto->GetId(), fLogIPs ? strprintf(" peeraddr=%s", pto->addr.ToStringAddrPort()) : "");
pto->fDisconnect = true;
return true;
} else {
LogPrintf("Timeout downloading headers from noban peer=%d%s, not disconnecting\n", pto->GetId(), fLogIPs ? strprintf(" peeraddr=%s", pto->addr.ToStringAddrPort()) : "");
// 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--;
peer->m_headers_sync_timeout = 0us;
}
}
} else {
// After we've caught up once, reset the timeout so we can't trigger
// disconnect later.
peer->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, *peer, GetTime<std::chrono::seconds>());
//
// Message: getdata (blocks)
//
std::vector<CInv> vGetData;
if (CanServeBlocks(*peer) && ((sync_blocks_and_headers_from_peer && !IsLimitedPeer(*peer)) || !m_chainman.IsInitialBlockDownload()) && state.vBlocksInFlight.size() < MAX_BLOCKS_IN_TRANSIT_PER_PEER) {
std::vector<const CBlockIndex*> vToDownload;
NodeId staller = -1;
auto get_inflight_budget = [&state]() {
return std::max(0, MAX_BLOCKS_IN_TRANSIT_PER_PEER - static_cast<int>(state.vBlocksInFlight.size()));
};
// If a snapshot chainstate is in use, we want to find its next blocks
// before the background chainstate to prioritize getting to network tip.
FindNextBlocksToDownload(*peer, get_inflight_budget(), vToDownload, staller);
if (m_chainman.BackgroundSyncInProgress() && !IsLimitedPeer(*peer)) {
TryDownloadingHistoricalBlocks(
*peer,
get_inflight_budget(),
vToDownload, m_chainman.GetBackgroundSyncTip(),
Assert(m_chainman.GetSnapshotBaseBlock()));
}
for (const CBlockIndex *pindex : vToDownload) {
uint32_t nFetchFlags = GetFetchFlags(*peer);
vGetData.emplace_back(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.vBlocksInFlight.empty() && 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) {
// Exclude m_recent_rejects_reconsiderable: we may be requesting a missing parent
// that was previously rejected for being too low feerate.
if (!AlreadyHaveTx(gtxid, /*include_reconsiderable=*/false)) {
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(*peer)), gtxid.GetHash());
if (vGetData.size() >= MAX_GETDATA_SZ) {
MakeAndPushMessage(*pto, 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())
MakeAndPushMessage(*pto, NetMsgType::GETDATA, vGetData);
} // release cs_main
MaybeSendFeefilter(*pto, *peer, current_time);
return true;
}
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