net_processing.cpp
1 // Copyright (c) 2009-2010 Satoshi Nakamoto 2 // Copyright (c) 2009-present The Bitcoin Core developers 3 // Distributed under the MIT software license, see the accompanying 4 // file COPYING or http://www.opensource.org/licenses/mit-license.php. 5 6 #include <net_processing.h> 7 8 #include <addrman.h> 9 #include <arith_uint256.h> 10 #include <banman.h> 11 #include <blockencodings.h> 12 #include <blockfilter.h> 13 #include <chain.h> 14 #include <chainparams.h> 15 #include <common/bloom.h> 16 #include <consensus/amount.h> 17 #include <consensus/params.h> 18 #include <consensus/validation.h> 19 #include <core_memusage.h> 20 #include <crypto/siphash.h> 21 #include <deploymentstatus.h> 22 #include <flatfile.h> 23 #include <headerssync.h> 24 #include <index/blockfilterindex.h> 25 #include <kernel/chain.h> 26 #include <logging.h> 27 #include <merkleblock.h> 28 #include <net.h> 29 #include <net_permissions.h> 30 #include <netaddress.h> 31 #include <netbase.h> 32 #include <netmessagemaker.h> 33 #include <node/blockstorage.h> 34 #include <node/connection_types.h> 35 #include <node/protocol_version.h> 36 #include <node/timeoffsets.h> 37 #include <node/txdownloadman.h> 38 #include <node/txorphanage.h> 39 #include <node/txreconciliation.h> 40 #include <node/warnings.h> 41 #include <policy/feerate.h> 42 #include <policy/fees/block_policy_estimator.h> 43 #include <policy/packages.h> 44 #include <policy/policy.h> 45 #include <primitives/block.h> 46 #include <primitives/transaction.h> 47 #include <protocol.h> 48 #include <random.h> 49 #include <scheduler.h> 50 #include <script/script.h> 51 #include <serialize.h> 52 #include <span.h> 53 #include <streams.h> 54 #include <sync.h> 55 #include <tinyformat.h> 56 #include <txmempool.h> 57 #include <uint256.h> 58 #include <util/check.h> 59 #include <util/strencodings.h> 60 #include <util/time.h> 61 #include <util/trace.h> 62 #include <validation.h> 63 64 #include <algorithm> 65 #include <array> 66 #include <atomic> 67 #include <compare> 68 #include <cstddef> 69 #include <deque> 70 #include <exception> 71 #include <functional> 72 #include <future> 73 #include <initializer_list> 74 #include <iterator> 75 #include <limits> 76 #include <list> 77 #include <map> 78 #include <memory> 79 #include <optional> 80 #include <queue> 81 #include <ranges> 82 #include <ratio> 83 #include <set> 84 #include <span> 85 #include <typeinfo> 86 #include <utility> 87 88 using namespace util::hex_literals; 89 90 TRACEPOINT_SEMAPHORE(net, inbound_message); 91 TRACEPOINT_SEMAPHORE(net, misbehaving_connection); 92 93 /** Headers download timeout. 94 * Timeout = base + per_header * (expected number of headers) */ 95 static constexpr auto HEADERS_DOWNLOAD_TIMEOUT_BASE = 15min; 96 static constexpr auto HEADERS_DOWNLOAD_TIMEOUT_PER_HEADER = 1ms; 97 /** How long to wait for a peer to respond to a getheaders request */ 98 static constexpr auto HEADERS_RESPONSE_TIME{2min}; 99 /** Protect at least this many outbound peers from disconnection due to slow/ 100 * behind headers chain. 101 */ 102 static constexpr int32_t MAX_OUTBOUND_PEERS_TO_PROTECT_FROM_DISCONNECT = 4; 103 /** Timeout for (unprotected) outbound peers to sync to our chainwork */ 104 static constexpr auto CHAIN_SYNC_TIMEOUT{20min}; 105 /** How frequently to check for stale tips */ 106 static constexpr auto STALE_CHECK_INTERVAL{10min}; 107 /** How frequently to check for extra outbound peers and disconnect */ 108 static constexpr auto EXTRA_PEER_CHECK_INTERVAL{45s}; 109 /** Minimum time an outbound-peer-eviction candidate must be connected for, in order to evict */ 110 static constexpr auto MINIMUM_CONNECT_TIME{30s}; 111 /** SHA256("main address relay")[0:8] */ 112 static constexpr uint64_t RANDOMIZER_ID_ADDRESS_RELAY = 0x3cac0035b5866b90ULL; 113 /// Age after which a stale block will no longer be served if requested as 114 /// protection against fingerprinting. Set to one month, denominated in seconds. 115 static constexpr int STALE_RELAY_AGE_LIMIT = 30 * 24 * 60 * 60; 116 /// Age after which a block is considered historical for purposes of rate 117 /// limiting block relay. Set to one week, denominated in seconds. 118 static constexpr int HISTORICAL_BLOCK_AGE = 7 * 24 * 60 * 60; 119 /** Time between pings automatically sent out for latency probing and keepalive */ 120 static constexpr auto PING_INTERVAL{2min}; 121 /** The maximum number of entries in a locator */ 122 static const unsigned int MAX_LOCATOR_SZ = 101; 123 /** The maximum number of entries in an 'inv' protocol message */ 124 static const unsigned int MAX_INV_SZ = 50000; 125 /** Limit to avoid sending big packets. Not used in processing incoming GETDATA for compatibility */ 126 static const unsigned int MAX_GETDATA_SZ = 1000; 127 /** Number of blocks that can be requested at any given time from a single peer. */ 128 static const int MAX_BLOCKS_IN_TRANSIT_PER_PEER = 16; 129 /** Default time during which a peer must stall block download progress before being disconnected. 130 * the actual timeout is increased temporarily if peers are disconnected for hitting the timeout */ 131 static constexpr auto BLOCK_STALLING_TIMEOUT_DEFAULT{2s}; 132 /** Maximum timeout for stalling block download. */ 133 static constexpr auto BLOCK_STALLING_TIMEOUT_MAX{64s}; 134 /** Maximum depth of blocks we're willing to serve as compact blocks to peers 135 * when requested. For older blocks, a regular BLOCK response will be sent. */ 136 static const int MAX_CMPCTBLOCK_DEPTH = 5; 137 /** Maximum depth of blocks we're willing to respond to GETBLOCKTXN requests for. */ 138 static const int MAX_BLOCKTXN_DEPTH = 10; 139 static_assert(MAX_BLOCKTXN_DEPTH <= MIN_BLOCKS_TO_KEEP, "MAX_BLOCKTXN_DEPTH too high"); 140 /** Size of the "block download window": how far ahead of our current height do we fetch? 141 * Larger windows tolerate larger download speed differences between peer, but increase the potential 142 * degree of disordering of blocks on disk (which make reindexing and pruning harder). We'll probably 143 * want to make this a per-peer adaptive value at some point. */ 144 static const unsigned int BLOCK_DOWNLOAD_WINDOW = 1024; 145 /** Block download timeout base, expressed in multiples of the block interval (i.e. 10 min) */ 146 static constexpr double BLOCK_DOWNLOAD_TIMEOUT_BASE = 1; 147 /** Additional block download timeout per parallel downloading peer (i.e. 5 min) */ 148 static constexpr double BLOCK_DOWNLOAD_TIMEOUT_PER_PEER = 0.5; 149 /** Maximum number of headers to announce when relaying blocks with headers message.*/ 150 static const unsigned int MAX_BLOCKS_TO_ANNOUNCE = 8; 151 /** Minimum blocks required to signal NODE_NETWORK_LIMITED */ 152 static const unsigned int NODE_NETWORK_LIMITED_MIN_BLOCKS = 288; 153 /** Window, in blocks, for connecting to NODE_NETWORK_LIMITED peers */ 154 static const unsigned int NODE_NETWORK_LIMITED_ALLOW_CONN_BLOCKS = 144; 155 /** Average delay between local address broadcasts */ 156 static constexpr auto AVG_LOCAL_ADDRESS_BROADCAST_INTERVAL{24h}; 157 /** Average delay between peer address broadcasts */ 158 static constexpr auto AVG_ADDRESS_BROADCAST_INTERVAL{30s}; 159 /** Delay between rotating the peers we relay a particular address to */ 160 static constexpr auto ROTATE_ADDR_RELAY_DEST_INTERVAL{24h}; 161 /** Average delay between trickled inventory transmissions for inbound peers. 162 * Blocks and peers with NetPermissionFlags::NoBan permission bypass this. */ 163 static constexpr auto INBOUND_INVENTORY_BROADCAST_INTERVAL{5s}; 164 /** Average delay between trickled inventory transmissions for outbound peers. 165 * Use a smaller delay as there is less privacy concern for them. 166 * Blocks and peers with NetPermissionFlags::NoBan permission bypass this. */ 167 static constexpr auto OUTBOUND_INVENTORY_BROADCAST_INTERVAL{2s}; 168 /** Maximum rate of inventory items to send per second. 169 * Limits the impact of low-fee transaction floods. */ 170 static constexpr unsigned int INVENTORY_BROADCAST_PER_SECOND{14}; 171 /** Target number of tx inventory items to send per transmission. */ 172 static constexpr unsigned int INVENTORY_BROADCAST_TARGET = INVENTORY_BROADCAST_PER_SECOND * count_seconds(INBOUND_INVENTORY_BROADCAST_INTERVAL); 173 /** Maximum number of inventory items to send per transmission. */ 174 static constexpr unsigned int INVENTORY_BROADCAST_MAX = 1000; 175 static_assert(INVENTORY_BROADCAST_MAX >= INVENTORY_BROADCAST_TARGET, "INVENTORY_BROADCAST_MAX too low"); 176 static_assert(INVENTORY_BROADCAST_MAX <= node::MAX_PEER_TX_ANNOUNCEMENTS, "INVENTORY_BROADCAST_MAX too high"); 177 /** Average delay between feefilter broadcasts in seconds. */ 178 static constexpr auto AVG_FEEFILTER_BROADCAST_INTERVAL{10min}; 179 /** Maximum feefilter broadcast delay after significant change. */ 180 static constexpr auto MAX_FEEFILTER_CHANGE_DELAY{5min}; 181 /** Maximum number of compact filters that may be requested with one getcfilters. See BIP 157. */ 182 static constexpr uint32_t MAX_GETCFILTERS_SIZE = 1000; 183 /** Maximum number of cf hashes that may be requested with one getcfheaders. See BIP 157. */ 184 static constexpr uint32_t MAX_GETCFHEADERS_SIZE = 2000; 185 /** the maximum percentage of addresses from our addrman to return in response to a getaddr message. */ 186 static constexpr size_t MAX_PCT_ADDR_TO_SEND = 23; 187 /** The maximum number of address records permitted in an ADDR message. */ 188 static constexpr size_t MAX_ADDR_TO_SEND{1000}; 189 /** The maximum rate of address records we're willing to process on average. Can be bypassed using 190 * the NetPermissionFlags::Addr permission. */ 191 static constexpr double MAX_ADDR_RATE_PER_SECOND{0.1}; 192 /** The soft limit of the address processing token bucket (the regular MAX_ADDR_RATE_PER_SECOND 193 * based increments won't go above this, but the MAX_ADDR_TO_SEND increment following GETADDR 194 * is exempt from this limit). */ 195 static constexpr size_t MAX_ADDR_PROCESSING_TOKEN_BUCKET{MAX_ADDR_TO_SEND}; 196 /** The compactblocks version we support. See BIP 152. */ 197 static constexpr uint64_t CMPCTBLOCKS_VERSION{2}; 198 199 // Internal stuff 200 namespace { 201 /** Blocks that are in flight, and that are in the queue to be downloaded. */ 202 struct QueuedBlock { 203 /** BlockIndex. We must have this since we only request blocks when we've already validated the header. */ 204 const CBlockIndex* pindex; 205 /** Optional, used for CMPCTBLOCK downloads */ 206 std::unique_ptr<PartiallyDownloadedBlock> partialBlock; 207 }; 208 209 /** 210 * Data structure for an individual peer. This struct is not protected by 211 * cs_main since it does not contain validation-critical data. 212 * 213 * Memory is owned by shared pointers and this object is destructed when 214 * the refcount drops to zero. 215 * 216 * Mutexes inside this struct must not be held when locking m_peer_mutex. 217 * 218 * TODO: move most members from CNodeState to this structure. 219 * TODO: move remaining application-layer data members from CNode to this structure. 220 */ 221 struct Peer { 222 /** Same id as the CNode object for this peer */ 223 const NodeId m_id{0}; 224 225 /** Services we offered to this peer. 226 * 227 * This is supplied by CConnman during peer initialization. It's const 228 * because there is no protocol defined for renegotiating services 229 * initially offered to a peer. The set of local services we offer should 230 * not change after initialization. 231 * 232 * An interesting example of this is NODE_NETWORK and initial block 233 * download: a node which starts up from scratch doesn't have any blocks 234 * to serve, but still advertises NODE_NETWORK because it will eventually 235 * fulfill this role after IBD completes. P2P code is written in such a 236 * way that it can gracefully handle peers who don't make good on their 237 * service advertisements. */ 238 const ServiceFlags m_our_services; 239 /** Services this peer offered to us. */ 240 std::atomic<ServiceFlags> m_their_services{NODE_NONE}; 241 242 //! Whether this peer is an inbound connection 243 const bool m_is_inbound; 244 245 /** Protects misbehavior data members */ 246 Mutex m_misbehavior_mutex; 247 /** Whether this peer should be disconnected and marked as discouraged (unless it has NetPermissionFlags::NoBan permission). */ 248 bool m_should_discourage GUARDED_BY(m_misbehavior_mutex){false}; 249 250 /** Protects block inventory data members */ 251 Mutex m_block_inv_mutex; 252 /** List of blocks that we'll announce via an `inv` message. 253 * There is no final sorting before sending, as they are always sent 254 * immediately and in the order requested. */ 255 std::vector<uint256> m_blocks_for_inv_relay GUARDED_BY(m_block_inv_mutex); 256 /** Unfiltered list of blocks that we'd like to announce via a `headers` 257 * message. If we can't announce via a `headers` message, we'll fall back to 258 * announcing via `inv`. */ 259 std::vector<uint256> m_blocks_for_headers_relay GUARDED_BY(m_block_inv_mutex); 260 /** The final block hash that we sent in an `inv` message to this peer. 261 * When the peer requests this block, we send an `inv` message to trigger 262 * the peer to request the next sequence of block hashes. 263 * Most peers use headers-first syncing, which doesn't use this mechanism */ 264 uint256 m_continuation_block GUARDED_BY(m_block_inv_mutex) {}; 265 266 /** Set to true once initial VERSION message was sent (only relevant for outbound peers). */ 267 bool m_outbound_version_message_sent GUARDED_BY(NetEventsInterface::g_msgproc_mutex){false}; 268 269 /** This peer's reported block height when we connected */ 270 std::atomic<int> m_starting_height{-1}; 271 272 /** The pong reply we're expecting, or 0 if no pong expected. */ 273 std::atomic<uint64_t> m_ping_nonce_sent{0}; 274 /** When the last ping was sent, or 0 if no ping was ever sent */ 275 std::atomic<std::chrono::microseconds> m_ping_start{0us}; 276 /** Whether a ping has been requested by the user */ 277 std::atomic<bool> m_ping_queued{false}; 278 279 /** Whether this peer relays txs via wtxid */ 280 std::atomic<bool> m_wtxid_relay{false}; 281 /** The feerate in the most recent BIP133 `feefilter` message sent to the peer. 282 * It is *not* a p2p protocol violation for the peer to send us 283 * transactions with a lower fee rate than this. See BIP133. */ 284 CAmount m_fee_filter_sent GUARDED_BY(NetEventsInterface::g_msgproc_mutex){0}; 285 /** Timestamp after which we will send the next BIP133 `feefilter` message 286 * to the peer. */ 287 std::chrono::microseconds m_next_send_feefilter GUARDED_BY(NetEventsInterface::g_msgproc_mutex){0}; 288 289 struct TxRelay { 290 mutable RecursiveMutex m_bloom_filter_mutex; 291 /** Whether we relay transactions to this peer. */ 292 bool m_relay_txs GUARDED_BY(m_bloom_filter_mutex){false}; 293 /** A bloom filter for which transactions to announce to the peer. See BIP37. */ 294 std::unique_ptr<CBloomFilter> m_bloom_filter PT_GUARDED_BY(m_bloom_filter_mutex) GUARDED_BY(m_bloom_filter_mutex){nullptr}; 295 296 mutable RecursiveMutex m_tx_inventory_mutex; 297 /** A filter of all the (w)txids that the peer has announced to 298 * us or we have announced to the peer. We use this to avoid announcing 299 * the same (w)txid to a peer that already has the transaction. */ 300 CRollingBloomFilter m_tx_inventory_known_filter GUARDED_BY(m_tx_inventory_mutex){50000, 0.000001}; 301 /** Set of wtxids we still have to announce. For non-wtxid-relay peers, 302 * we retrieve the txid from the corresponding mempool transaction when 303 * constructing the `inv` message. We use the mempool to sort transactions 304 * in dependency order before relay, so this does not have to be sorted. */ 305 std::set<Wtxid> m_tx_inventory_to_send GUARDED_BY(m_tx_inventory_mutex); 306 /** Whether the peer has requested us to send our complete mempool. Only 307 * permitted if the peer has NetPermissionFlags::Mempool or we advertise 308 * NODE_BLOOM. See BIP35. */ 309 bool m_send_mempool GUARDED_BY(m_tx_inventory_mutex){false}; 310 /** The next time after which we will send an `inv` message containing 311 * transaction announcements to this peer. */ 312 std::chrono::microseconds m_next_inv_send_time GUARDED_BY(m_tx_inventory_mutex){0}; 313 /** The mempool sequence num at which we sent the last `inv` message to this peer. 314 * Can relay txs with lower sequence numbers than this (see CTxMempool::info_for_relay). */ 315 uint64_t m_last_inv_sequence GUARDED_BY(m_tx_inventory_mutex){1}; 316 317 /** Minimum fee rate with which to filter transaction announcements to this node. See BIP133. */ 318 std::atomic<CAmount> m_fee_filter_received{0}; 319 }; 320 321 /* Initializes a TxRelay struct for this peer. Can be called at most once for a peer. */ 322 TxRelay* SetTxRelay() EXCLUSIVE_LOCKS_REQUIRED(!m_tx_relay_mutex) 323 { 324 LOCK(m_tx_relay_mutex); 325 Assume(!m_tx_relay); 326 m_tx_relay = std::make_unique<Peer::TxRelay>(); 327 return m_tx_relay.get(); 328 }; 329 330 TxRelay* GetTxRelay() EXCLUSIVE_LOCKS_REQUIRED(!m_tx_relay_mutex) 331 { 332 return WITH_LOCK(m_tx_relay_mutex, return m_tx_relay.get()); 333 }; 334 335 /** A vector of addresses to send to the peer, limited to MAX_ADDR_TO_SEND. */ 336 std::vector<CAddress> m_addrs_to_send GUARDED_BY(NetEventsInterface::g_msgproc_mutex); 337 /** Probabilistic filter to track recent addr messages relayed with this 338 * peer. Used to avoid relaying redundant addresses to this peer. 339 * 340 * We initialize this filter for outbound peers (other than 341 * block-relay-only connections) or when an inbound peer sends us an 342 * address related message (ADDR, ADDRV2, GETADDR). 343 * 344 * Presence of this filter must correlate with m_addr_relay_enabled. 345 **/ 346 std::unique_ptr<CRollingBloomFilter> m_addr_known GUARDED_BY(NetEventsInterface::g_msgproc_mutex); 347 /** Whether we are participating in address relay with this connection. 348 * 349 * We set this bool to true for outbound peers (other than 350 * block-relay-only connections), or when an inbound peer sends us an 351 * address related message (ADDR, ADDRV2, GETADDR). 352 * 353 * We use this bool to decide whether a peer is eligible for gossiping 354 * addr messages. This avoids relaying to peers that are unlikely to 355 * forward them, effectively blackholing self announcements. Reasons 356 * peers might support addr relay on the link include that they connected 357 * to us as a block-relay-only peer or they are a light client. 358 * 359 * This field must correlate with whether m_addr_known has been 360 * initialized.*/ 361 std::atomic_bool m_addr_relay_enabled{false}; 362 /** Whether a getaddr request to this peer is outstanding. */ 363 bool m_getaddr_sent GUARDED_BY(NetEventsInterface::g_msgproc_mutex){false}; 364 /** Guards address sending timers. */ 365 mutable Mutex m_addr_send_times_mutex; 366 /** Time point to send the next ADDR message to this peer. */ 367 std::chrono::microseconds m_next_addr_send GUARDED_BY(m_addr_send_times_mutex){0}; 368 /** Time point to possibly re-announce our local address to this peer. */ 369 std::chrono::microseconds m_next_local_addr_send GUARDED_BY(m_addr_send_times_mutex){0}; 370 /** Whether the peer has signaled support for receiving ADDRv2 (BIP155) 371 * messages, indicating a preference to receive ADDRv2 instead of ADDR ones. */ 372 std::atomic_bool m_wants_addrv2{false}; 373 /** Whether this peer has already sent us a getaddr message. */ 374 bool m_getaddr_recvd GUARDED_BY(NetEventsInterface::g_msgproc_mutex){false}; 375 /** Number of addresses that can be processed from this peer. Start at 1 to 376 * permit self-announcement. */ 377 double m_addr_token_bucket GUARDED_BY(NetEventsInterface::g_msgproc_mutex){1.0}; 378 /** When m_addr_token_bucket was last updated */ 379 std::chrono::microseconds m_addr_token_timestamp GUARDED_BY(NetEventsInterface::g_msgproc_mutex){GetTime<std::chrono::microseconds>()}; 380 /** Total number of addresses that were dropped due to rate limiting. */ 381 std::atomic<uint64_t> m_addr_rate_limited{0}; 382 /** Total number of addresses that were processed (excludes rate-limited ones). */ 383 std::atomic<uint64_t> m_addr_processed{0}; 384 385 /** Whether we've sent this peer a getheaders in response to an inv prior to initial-headers-sync completing */ 386 bool m_inv_triggered_getheaders_before_sync GUARDED_BY(NetEventsInterface::g_msgproc_mutex){false}; 387 388 /** Protects m_getdata_requests **/ 389 Mutex m_getdata_requests_mutex; 390 /** Work queue of items requested by this peer **/ 391 std::deque<CInv> m_getdata_requests GUARDED_BY(m_getdata_requests_mutex); 392 393 /** Time of the last getheaders message to this peer */ 394 NodeClock::time_point m_last_getheaders_timestamp GUARDED_BY(NetEventsInterface::g_msgproc_mutex){}; 395 396 /** Protects m_headers_sync **/ 397 Mutex m_headers_sync_mutex; 398 /** Headers-sync state for this peer (eg for initial sync, or syncing large 399 * reorgs) **/ 400 std::unique_ptr<HeadersSyncState> m_headers_sync PT_GUARDED_BY(m_headers_sync_mutex) GUARDED_BY(m_headers_sync_mutex) {}; 401 402 /** Whether we've sent our peer a sendheaders message. **/ 403 std::atomic<bool> m_sent_sendheaders{false}; 404 405 /** When to potentially disconnect peer for stalling headers download */ 406 std::chrono::microseconds m_headers_sync_timeout GUARDED_BY(NetEventsInterface::g_msgproc_mutex){0us}; 407 408 /** Whether this peer wants invs or headers (when possible) for block announcements */ 409 bool m_prefers_headers GUARDED_BY(NetEventsInterface::g_msgproc_mutex){false}; 410 411 /** Time offset computed during the version handshake based on the 412 * timestamp the peer sent in the version message. */ 413 std::atomic<std::chrono::seconds> m_time_offset{0s}; 414 415 explicit Peer(NodeId id, ServiceFlags our_services, bool is_inbound) 416 : m_id{id} 417 , m_our_services{our_services} 418 , m_is_inbound{is_inbound} 419 {} 420 421 private: 422 mutable Mutex m_tx_relay_mutex; 423 424 /** Transaction relay data. May be a nullptr. */ 425 std::unique_ptr<TxRelay> m_tx_relay GUARDED_BY(m_tx_relay_mutex); 426 }; 427 428 using PeerRef = std::shared_ptr<Peer>; 429 430 /** 431 * Maintain validation-specific state about nodes, protected by cs_main, instead 432 * by CNode's own locks. This simplifies asynchronous operation, where 433 * processing of incoming data is done after the ProcessMessage call returns, 434 * and we're no longer holding the node's locks. 435 */ 436 struct CNodeState { 437 //! The best known block we know this peer has announced. 438 const CBlockIndex* pindexBestKnownBlock{nullptr}; 439 //! The hash of the last unknown block this peer has announced. 440 uint256 hashLastUnknownBlock{}; 441 //! The last full block we both have. 442 const CBlockIndex* pindexLastCommonBlock{nullptr}; 443 //! The best header we have sent our peer. 444 const CBlockIndex* pindexBestHeaderSent{nullptr}; 445 //! Whether we've started headers synchronization with this peer. 446 bool fSyncStarted{false}; 447 //! Since when we're stalling block download progress (in microseconds), or 0. 448 std::chrono::microseconds m_stalling_since{0us}; 449 std::list<QueuedBlock> vBlocksInFlight; 450 //! When the first entry in vBlocksInFlight started downloading. Don't care when vBlocksInFlight is empty. 451 std::chrono::microseconds m_downloading_since{0us}; 452 //! Whether we consider this a preferred download peer. 453 bool fPreferredDownload{false}; 454 /** Whether this peer wants invs or cmpctblocks (when possible) for block announcements. */ 455 bool m_requested_hb_cmpctblocks{false}; 456 /** Whether this peer will send us cmpctblocks if we request them. */ 457 bool m_provides_cmpctblocks{false}; 458 459 /** State used to enforce CHAIN_SYNC_TIMEOUT and EXTRA_PEER_CHECK_INTERVAL logic. 460 * 461 * Both are only in effect for outbound, non-manual, non-protected connections. 462 * Any peer protected (m_protect = true) is not chosen for eviction. A peer is 463 * marked as protected if all of these are true: 464 * - its connection type is IsBlockOnlyConn() == false 465 * - it gave us a valid connecting header 466 * - we haven't reached MAX_OUTBOUND_PEERS_TO_PROTECT_FROM_DISCONNECT yet 467 * - its chain tip has at least as much work as ours 468 * 469 * CHAIN_SYNC_TIMEOUT: if a peer's best known block has less work than our tip, 470 * set a timeout CHAIN_SYNC_TIMEOUT in the future: 471 * - If at timeout their best known block now has more work than our tip 472 * when the timeout was set, then either reset the timeout or clear it 473 * (after comparing against our current tip's work) 474 * - If at timeout their best known block still has less work than our 475 * tip did when the timeout was set, then send a getheaders message, 476 * and set a shorter timeout, HEADERS_RESPONSE_TIME seconds in future. 477 * If their best known block is still behind when that new timeout is 478 * reached, disconnect. 479 * 480 * EXTRA_PEER_CHECK_INTERVAL: after each interval, if we have too many outbound peers, 481 * drop the outbound one that least recently announced us a new block. 482 */ 483 struct ChainSyncTimeoutState { 484 //! A timeout used for checking whether our peer has sufficiently synced 485 std::chrono::seconds m_timeout{0s}; 486 //! A header with the work we require on our peer's chain 487 const CBlockIndex* m_work_header{nullptr}; 488 //! After timeout is reached, set to true after sending getheaders 489 bool m_sent_getheaders{false}; 490 //! Whether this peer is protected from disconnection due to a bad/slow chain 491 bool m_protect{false}; 492 }; 493 494 ChainSyncTimeoutState m_chain_sync; 495 496 //! Time of last new block announcement 497 int64_t m_last_block_announcement{0}; 498 }; 499 500 class PeerManagerImpl final : public PeerManager 501 { 502 public: 503 PeerManagerImpl(CConnman& connman, AddrMan& addrman, 504 BanMan* banman, ChainstateManager& chainman, 505 CTxMemPool& pool, node::Warnings& warnings, Options opts); 506 507 /** Overridden from CValidationInterface. */ 508 void ActiveTipChange(const CBlockIndex& new_tip, bool) override 509 EXCLUSIVE_LOCKS_REQUIRED(!m_tx_download_mutex); 510 void BlockConnected(ChainstateRole role, const std::shared_ptr<const CBlock>& pblock, const CBlockIndex* pindexConnected) override 511 EXCLUSIVE_LOCKS_REQUIRED(!m_tx_download_mutex); 512 void BlockDisconnected(const std::shared_ptr<const CBlock> &block, const CBlockIndex* pindex) override 513 EXCLUSIVE_LOCKS_REQUIRED(!m_tx_download_mutex); 514 void UpdatedBlockTip(const CBlockIndex *pindexNew, const CBlockIndex *pindexFork, bool fInitialDownload) override 515 EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex); 516 void BlockChecked(const std::shared_ptr<const CBlock>& block, const BlockValidationState& state) override 517 EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex); 518 void NewPoWValidBlock(const CBlockIndex *pindex, const std::shared_ptr<const CBlock>& pblock) override 519 EXCLUSIVE_LOCKS_REQUIRED(!m_most_recent_block_mutex); 520 521 /** Implement NetEventsInterface */ 522 void InitializeNode(const CNode& node, ServiceFlags our_services) override EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex, !m_tx_download_mutex); 523 void FinalizeNode(const CNode& node) override EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex, !m_headers_presync_mutex, !m_tx_download_mutex); 524 bool HasAllDesirableServiceFlags(ServiceFlags services) const override; 525 bool ProcessMessages(CNode* pfrom, std::atomic<bool>& interrupt) override 526 EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex, !m_most_recent_block_mutex, !m_headers_presync_mutex, g_msgproc_mutex, !m_tx_download_mutex); 527 bool SendMessages(CNode* pto) override 528 EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex, !m_most_recent_block_mutex, g_msgproc_mutex, !m_tx_download_mutex); 529 530 /** Implement PeerManager */ 531 void StartScheduledTasks(CScheduler& scheduler) override; 532 void CheckForStaleTipAndEvictPeers() override; 533 std::optional<std::string> FetchBlock(NodeId peer_id, const CBlockIndex& block_index) override 534 EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex); 535 bool GetNodeStateStats(NodeId nodeid, CNodeStateStats& stats) const override EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex); 536 std::vector<node::TxOrphanage::OrphanInfo> GetOrphanTransactions() override EXCLUSIVE_LOCKS_REQUIRED(!m_tx_download_mutex); 537 PeerManagerInfo GetInfo() const override EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex); 538 void SendPings() override EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex); 539 void RelayTransaction(const Txid& txid, const Wtxid& wtxid) override EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex); 540 void SetBestBlock(int height, std::chrono::seconds time) override 541 { 542 m_best_height = height; 543 m_best_block_time = time; 544 }; 545 void UnitTestMisbehaving(NodeId peer_id) override EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex) { Misbehaving(*Assert(GetPeerRef(peer_id)), ""); }; 546 void ProcessMessage(CNode& pfrom, const std::string& msg_type, DataStream& vRecv, 547 const std::chrono::microseconds time_received, const std::atomic<bool>& interruptMsgProc) override 548 EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex, !m_most_recent_block_mutex, !m_headers_presync_mutex, g_msgproc_mutex, !m_tx_download_mutex); 549 void UpdateLastBlockAnnounceTime(NodeId node, int64_t time_in_seconds) override; 550 ServiceFlags GetDesirableServiceFlags(ServiceFlags services) const override; 551 552 private: 553 /** Consider evicting an outbound peer based on the amount of time they've been behind our tip */ 554 void ConsiderEviction(CNode& pto, Peer& peer, std::chrono::seconds time_in_seconds) EXCLUSIVE_LOCKS_REQUIRED(cs_main, g_msgproc_mutex); 555 556 /** If we have extra outbound peers, try to disconnect the one with the oldest block announcement */ 557 void EvictExtraOutboundPeers(std::chrono::seconds now) EXCLUSIVE_LOCKS_REQUIRED(cs_main); 558 559 /** Retrieve unbroadcast transactions from the mempool and reattempt sending to peers */ 560 void ReattemptInitialBroadcast(CScheduler& scheduler) EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex); 561 562 /** Get a shared pointer to the Peer object. 563 * May return an empty shared_ptr if the Peer object can't be found. */ 564 PeerRef GetPeerRef(NodeId id) const EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex); 565 566 /** Get a shared pointer to the Peer object and remove it from m_peer_map. 567 * May return an empty shared_ptr if the Peer object can't be found. */ 568 PeerRef RemovePeer(NodeId id) EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex); 569 570 /** Mark a peer as misbehaving, which will cause it to be disconnected and its 571 * address discouraged. */ 572 void Misbehaving(Peer& peer, const std::string& message); 573 574 /** 575 * Potentially mark a node discouraged based on the contents of a BlockValidationState object 576 * 577 * @param[in] via_compact_block this bool is passed in because net_processing should 578 * punish peers differently depending on whether the data was provided in a compact 579 * block message or not. If the compact block had a valid header, but contained invalid 580 * txs, the peer should not be punished. See BIP 152. 581 */ 582 void MaybePunishNodeForBlock(NodeId nodeid, const BlockValidationState& state, 583 bool via_compact_block, const std::string& message = "") 584 EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex); 585 586 /** Maybe disconnect a peer and discourage future connections from its address. 587 * 588 * @param[in] pnode The node to check. 589 * @param[in] peer The peer object to check. 590 * @return True if the peer was marked for disconnection in this function 591 */ 592 bool MaybeDiscourageAndDisconnect(CNode& pnode, Peer& peer); 593 594 /** Handle a transaction whose result was not MempoolAcceptResult::ResultType::VALID. 595 * @param[in] first_time_failure Whether we should consider inserting into vExtraTxnForCompact, adding 596 * a new orphan to resolve, or looking for a package to submit. 597 * Set to true for transactions just received over p2p. 598 * Set to false if the tx has already been rejected before, 599 * e.g. is already in the orphanage, to avoid adding duplicate entries. 600 * Updates m_txrequest, m_lazy_recent_rejects, m_lazy_recent_rejects_reconsiderable, m_orphanage, and vExtraTxnForCompact. 601 * 602 * @returns a PackageToValidate if this transaction has a reconsiderable failure and an eligible package was found, 603 * or std::nullopt otherwise. 604 */ 605 std::optional<node::PackageToValidate> ProcessInvalidTx(NodeId nodeid, const CTransactionRef& tx, const TxValidationState& result, 606 bool first_time_failure) 607 EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex, g_msgproc_mutex, m_tx_download_mutex); 608 609 /** Handle a transaction whose result was MempoolAcceptResult::ResultType::VALID. 610 * Updates m_txrequest, m_orphanage, and vExtraTxnForCompact. Also queues the tx for relay. */ 611 void ProcessValidTx(NodeId nodeid, const CTransactionRef& tx, const std::list<CTransactionRef>& replaced_transactions) 612 EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex, g_msgproc_mutex, m_tx_download_mutex); 613 614 /** Handle the results of package validation: calls ProcessValidTx and ProcessInvalidTx for 615 * individual transactions, and caches rejection for the package as a group. 616 */ 617 void ProcessPackageResult(const node::PackageToValidate& package_to_validate, const PackageMempoolAcceptResult& package_result) 618 EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex, g_msgproc_mutex, m_tx_download_mutex); 619 620 /** 621 * Reconsider orphan transactions after a parent has been accepted to the mempool. 622 * 623 * @peer[in] peer The peer whose orphan transactions we will reconsider. Generally only 624 * one orphan will be reconsidered on each call of this function. If an 625 * accepted orphan has orphaned children, those will need to be 626 * reconsidered, creating more work, possibly for other peers. 627 * @return True if meaningful work was done (an orphan was accepted/rejected). 628 * If no meaningful work was done, then the work set for this peer 629 * will be empty. 630 */ 631 bool ProcessOrphanTx(Peer& peer) 632 EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex, g_msgproc_mutex, !m_tx_download_mutex); 633 634 /** Process a single headers message from a peer. 635 * 636 * @param[in] pfrom CNode of the peer 637 * @param[in] peer The peer sending us the headers 638 * @param[in] headers The headers received. Note that this may be modified within ProcessHeadersMessage. 639 * @param[in] via_compact_block Whether this header came in via compact block handling. 640 */ 641 void ProcessHeadersMessage(CNode& pfrom, Peer& peer, 642 std::vector<CBlockHeader>&& headers, 643 bool via_compact_block) 644 EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex, !m_headers_presync_mutex, g_msgproc_mutex); 645 /** Various helpers for headers processing, invoked by ProcessHeadersMessage() */ 646 /** Return true if headers are continuous and have valid proof-of-work (DoS points assigned on failure) */ 647 bool CheckHeadersPoW(const std::vector<CBlockHeader>& headers, const Consensus::Params& consensusParams, Peer& peer); 648 /** Calculate an anti-DoS work threshold for headers chains */ 649 arith_uint256 GetAntiDoSWorkThreshold(); 650 /** Deal with state tracking and headers sync for peers that send 651 * non-connecting headers (this can happen due to BIP 130 headers 652 * announcements for blocks interacting with the 2hr (MAX_FUTURE_BLOCK_TIME) rule). */ 653 void HandleUnconnectingHeaders(CNode& pfrom, Peer& peer, const std::vector<CBlockHeader>& headers) EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex); 654 /** Return true if the headers connect to each other, false otherwise */ 655 bool CheckHeadersAreContinuous(const std::vector<CBlockHeader>& headers) const; 656 /** Try to continue a low-work headers sync that has already begun. 657 * Assumes the caller has already verified the headers connect, and has 658 * checked that each header satisfies the proof-of-work target included in 659 * the header. 660 * @param[in] peer The peer we're syncing with. 661 * @param[in] pfrom CNode of the peer 662 * @param[in,out] headers The headers to be processed. 663 * @return True if the passed in headers were successfully processed 664 * as the continuation of a low-work headers sync in progress; 665 * false otherwise. 666 * If false, the passed in headers will be returned back to 667 * the caller. 668 * If true, the returned headers may be empty, indicating 669 * there is no more work for the caller to do; or the headers 670 * may be populated with entries that have passed anti-DoS 671 * checks (and therefore may be validated for block index 672 * acceptance by the caller). 673 */ 674 bool IsContinuationOfLowWorkHeadersSync(Peer& peer, CNode& pfrom, 675 std::vector<CBlockHeader>& headers) 676 EXCLUSIVE_LOCKS_REQUIRED(peer.m_headers_sync_mutex, !m_headers_presync_mutex, g_msgproc_mutex); 677 /** Check work on a headers chain to be processed, and if insufficient, 678 * initiate our anti-DoS headers sync mechanism. 679 * 680 * @param[in] peer The peer whose headers we're processing. 681 * @param[in] pfrom CNode of the peer 682 * @param[in] chain_start_header Where these headers connect in our index. 683 * @param[in,out] headers The headers to be processed. 684 * 685 * @return True if chain was low work (headers will be empty after 686 * calling); false otherwise. 687 */ 688 bool TryLowWorkHeadersSync(Peer& peer, CNode& pfrom, 689 const CBlockIndex* chain_start_header, 690 std::vector<CBlockHeader>& headers) 691 EXCLUSIVE_LOCKS_REQUIRED(!peer.m_headers_sync_mutex, !m_peer_mutex, !m_headers_presync_mutex, g_msgproc_mutex); 692 693 /** Return true if the given header is an ancestor of 694 * m_chainman.m_best_header or our current tip */ 695 bool IsAncestorOfBestHeaderOrTip(const CBlockIndex* header) EXCLUSIVE_LOCKS_REQUIRED(cs_main); 696 697 /** Request further headers from this peer with a given locator. 698 * We don't issue a getheaders message if we have a recent one outstanding. 699 * This returns true if a getheaders is actually sent, and false otherwise. 700 */ 701 bool MaybeSendGetHeaders(CNode& pfrom, const CBlockLocator& locator, Peer& peer) EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex); 702 /** Potentially fetch blocks from this peer upon receipt of a new headers tip */ 703 void HeadersDirectFetchBlocks(CNode& pfrom, const Peer& peer, const CBlockIndex& last_header); 704 /** Update peer state based on received headers message */ 705 void UpdatePeerStateForReceivedHeaders(CNode& pfrom, Peer& peer, const CBlockIndex& last_header, bool received_new_header, bool may_have_more_headers) 706 EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex); 707 708 void SendBlockTransactions(CNode& pfrom, Peer& peer, const CBlock& block, const BlockTransactionsRequest& req); 709 710 /** Send a message to a peer */ 711 void PushMessage(CNode& node, CSerializedNetMsg&& msg) const { m_connman.PushMessage(&node, std::move(msg)); } 712 template <typename... Args> 713 void MakeAndPushMessage(CNode& node, std::string msg_type, Args&&... args) const 714 { 715 m_connman.PushMessage(&node, NetMsg::Make(std::move(msg_type), std::forward<Args>(args)...)); 716 } 717 718 /** Send a version message to a peer */ 719 void PushNodeVersion(CNode& pnode, const Peer& peer); 720 721 /** Send a ping message every PING_INTERVAL or if requested via RPC. May 722 * mark the peer to be disconnected if a ping has timed out. 723 * We use mockable time for ping timeouts, so setmocktime may cause pings 724 * to time out. */ 725 void MaybeSendPing(CNode& node_to, Peer& peer, std::chrono::microseconds now); 726 727 /** Send `addr` messages on a regular schedule. */ 728 void MaybeSendAddr(CNode& node, Peer& peer, std::chrono::microseconds current_time) EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex); 729 730 /** Send a single `sendheaders` message, after we have completed headers sync with a peer. */ 731 void MaybeSendSendHeaders(CNode& node, Peer& peer) EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex); 732 733 /** Relay (gossip) an address to a few randomly chosen nodes. 734 * 735 * @param[in] originator The id of the peer that sent us the address. We don't want to relay it back. 736 * @param[in] addr Address to relay. 737 * @param[in] fReachable Whether the address' network is reachable. We relay unreachable 738 * addresses less. 739 */ 740 void RelayAddress(NodeId originator, const CAddress& addr, bool fReachable) EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex, g_msgproc_mutex); 741 742 /** Send `feefilter` message. */ 743 void MaybeSendFeefilter(CNode& node, Peer& peer, std::chrono::microseconds current_time) EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex); 744 745 FastRandomContext m_rng GUARDED_BY(NetEventsInterface::g_msgproc_mutex); 746 747 FeeFilterRounder m_fee_filter_rounder GUARDED_BY(NetEventsInterface::g_msgproc_mutex); 748 749 const CChainParams& m_chainparams; 750 CConnman& m_connman; 751 AddrMan& m_addrman; 752 /** Pointer to this node's banman. May be nullptr - check existence before dereferencing. */ 753 BanMan* const m_banman; 754 ChainstateManager& m_chainman; 755 CTxMemPool& m_mempool; 756 757 /** Synchronizes tx download including TxRequestTracker, rejection filters, and TxOrphanage. 758 * Lock invariants: 759 * - A txhash (txid or wtxid) in m_txrequest is not also in m_orphanage. 760 * - A txhash (txid or wtxid) in m_txrequest is not also in m_lazy_recent_rejects. 761 * - A txhash (txid or wtxid) in m_txrequest is not also in m_lazy_recent_rejects_reconsiderable. 762 * - A txhash (txid or wtxid) in m_txrequest is not also in m_lazy_recent_confirmed_transactions. 763 * - Each data structure's limits hold (m_orphanage max size, m_txrequest per-peer limits, etc). 764 */ 765 Mutex m_tx_download_mutex ACQUIRED_BEFORE(m_mempool.cs); 766 node::TxDownloadManager m_txdownloadman GUARDED_BY(m_tx_download_mutex); 767 768 std::unique_ptr<TxReconciliationTracker> m_txreconciliation; 769 770 /** The height of the best chain */ 771 std::atomic<int> m_best_height{-1}; 772 /** The time of the best chain tip block */ 773 std::atomic<std::chrono::seconds> m_best_block_time{0s}; 774 775 /** Next time to check for stale tip */ 776 std::chrono::seconds m_stale_tip_check_time GUARDED_BY(cs_main){0s}; 777 778 node::Warnings& m_warnings; 779 TimeOffsets m_outbound_time_offsets{m_warnings}; 780 781 const Options m_opts; 782 783 bool RejectIncomingTxs(const CNode& peer) const; 784 785 /** Whether we've completed initial sync yet, for determining when to turn 786 * on extra block-relay-only peers. */ 787 bool m_initial_sync_finished GUARDED_BY(cs_main){false}; 788 789 /** Protects m_peer_map. This mutex must not be locked while holding a lock 790 * on any of the mutexes inside a Peer object. */ 791 mutable Mutex m_peer_mutex; 792 /** 793 * Map of all Peer objects, keyed by peer id. This map is protected 794 * by the m_peer_mutex. Once a shared pointer reference is 795 * taken, the lock may be released. Individual fields are protected by 796 * their own locks. 797 */ 798 std::map<NodeId, PeerRef> m_peer_map GUARDED_BY(m_peer_mutex); 799 800 /** Map maintaining per-node state. */ 801 std::map<NodeId, CNodeState> m_node_states GUARDED_BY(cs_main); 802 803 /** Get a pointer to a const CNodeState, used when not mutating the CNodeState object. */ 804 const CNodeState* State(NodeId pnode) const EXCLUSIVE_LOCKS_REQUIRED(cs_main); 805 /** Get a pointer to a mutable CNodeState. */ 806 CNodeState* State(NodeId pnode) EXCLUSIVE_LOCKS_REQUIRED(cs_main); 807 808 uint32_t GetFetchFlags(const Peer& peer) const; 809 810 std::map<uint64_t, std::chrono::microseconds> m_next_inv_to_inbounds_per_network_key GUARDED_BY(g_msgproc_mutex); 811 812 /** Number of nodes with fSyncStarted. */ 813 int nSyncStarted GUARDED_BY(cs_main) = 0; 814 815 /** Hash of the last block we received via INV */ 816 uint256 m_last_block_inv_triggering_headers_sync GUARDED_BY(g_msgproc_mutex){}; 817 818 /** 819 * Sources of received blocks, saved to be able punish them when processing 820 * happens afterwards. 821 * Set mapBlockSource[hash].second to false if the node should not be 822 * punished if the block is invalid. 823 */ 824 std::map<uint256, std::pair<NodeId, bool>> mapBlockSource GUARDED_BY(cs_main); 825 826 /** Number of peers with wtxid relay. */ 827 std::atomic<int> m_wtxid_relay_peers{0}; 828 829 /** Number of outbound peers with m_chain_sync.m_protect. */ 830 int m_outbound_peers_with_protect_from_disconnect GUARDED_BY(cs_main) = 0; 831 832 /** Number of preferable block download peers. */ 833 int m_num_preferred_download_peers GUARDED_BY(cs_main){0}; 834 835 /** Stalling timeout for blocks in IBD */ 836 std::atomic<std::chrono::seconds> m_block_stalling_timeout{BLOCK_STALLING_TIMEOUT_DEFAULT}; 837 838 /** 839 * For sending `inv`s to inbound peers, we use a single (exponentially 840 * distributed) timer for all peers with the same network key. If we used a separate timer for each 841 * peer, a spy node could make multiple inbound connections to us to 842 * accurately determine when we received a transaction (and potentially 843 * determine the transaction's origin). Each network key has its own timer 844 * to make fingerprinting harder. */ 845 std::chrono::microseconds NextInvToInbounds(std::chrono::microseconds now, 846 std::chrono::seconds average_interval, 847 uint64_t network_key) EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex); 848 849 850 // All of the following cache a recent block, and are protected by m_most_recent_block_mutex 851 Mutex m_most_recent_block_mutex; 852 std::shared_ptr<const CBlock> m_most_recent_block GUARDED_BY(m_most_recent_block_mutex); 853 std::shared_ptr<const CBlockHeaderAndShortTxIDs> m_most_recent_compact_block GUARDED_BY(m_most_recent_block_mutex); 854 uint256 m_most_recent_block_hash GUARDED_BY(m_most_recent_block_mutex); 855 std::unique_ptr<const std::map<GenTxid, CTransactionRef>> m_most_recent_block_txs GUARDED_BY(m_most_recent_block_mutex); 856 857 // Data about the low-work headers synchronization, aggregated from all peers' HeadersSyncStates. 858 /** Mutex guarding the other m_headers_presync_* variables. */ 859 Mutex m_headers_presync_mutex; 860 /** A type to represent statistics about a peer's low-work headers sync. 861 * 862 * - The first field is the total verified amount of work in that synchronization. 863 * - The second is: 864 * - nullopt: the sync is in REDOWNLOAD phase (phase 2). 865 * - {height, timestamp}: the sync has the specified tip height and block timestamp (phase 1). 866 */ 867 using HeadersPresyncStats = std::pair<arith_uint256, std::optional<std::pair<int64_t, uint32_t>>>; 868 /** Statistics for all peers in low-work headers sync. */ 869 std::map<NodeId, HeadersPresyncStats> m_headers_presync_stats GUARDED_BY(m_headers_presync_mutex) {}; 870 /** The peer with the most-work entry in m_headers_presync_stats. */ 871 NodeId m_headers_presync_bestpeer GUARDED_BY(m_headers_presync_mutex) {-1}; 872 /** The m_headers_presync_stats improved, and needs signalling. */ 873 std::atomic_bool m_headers_presync_should_signal{false}; 874 875 /** Height of the highest block announced using BIP 152 high-bandwidth mode. */ 876 int m_highest_fast_announce GUARDED_BY(::cs_main){0}; 877 878 /** Have we requested this block from a peer */ 879 bool IsBlockRequested(const uint256& hash) EXCLUSIVE_LOCKS_REQUIRED(cs_main); 880 881 /** Have we requested this block from an outbound peer */ 882 bool IsBlockRequestedFromOutbound(const uint256& hash) EXCLUSIVE_LOCKS_REQUIRED(cs_main, !m_peer_mutex); 883 884 /** Remove this block from our tracked requested blocks. Called if: 885 * - the block has been received from a peer 886 * - the request for the block has timed out 887 * If "from_peer" is specified, then only remove the block if it is in 888 * flight from that peer (to avoid one peer's network traffic from 889 * affecting another's state). 890 */ 891 void RemoveBlockRequest(const uint256& hash, std::optional<NodeId> from_peer) EXCLUSIVE_LOCKS_REQUIRED(cs_main); 892 893 /* Mark a block as in flight 894 * Returns false, still setting pit, if the block was already in flight from the same peer 895 * pit will only be valid as long as the same cs_main lock is being held 896 */ 897 bool BlockRequested(NodeId nodeid, const CBlockIndex& block, std::list<QueuedBlock>::iterator** pit = nullptr) EXCLUSIVE_LOCKS_REQUIRED(cs_main); 898 899 bool TipMayBeStale() EXCLUSIVE_LOCKS_REQUIRED(cs_main); 900 901 /** Update pindexLastCommonBlock and add not-in-flight missing successors to vBlocks, until it has 902 * at most count entries. 903 */ 904 void FindNextBlocksToDownload(const Peer& peer, unsigned int count, std::vector<const CBlockIndex*>& vBlocks, NodeId& nodeStaller) EXCLUSIVE_LOCKS_REQUIRED(cs_main); 905 906 /** Request blocks for the background chainstate, if one is in use. */ 907 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); 908 909 /** 910 * \brief Find next blocks to download from a peer after a starting block. 911 * 912 * \param vBlocks Vector of blocks to download which will be appended to. 913 * \param peer Peer which blocks will be downloaded from. 914 * \param state Pointer to the state of the peer. 915 * \param pindexWalk Pointer to the starting block to add to vBlocks. 916 * \param count Maximum number of blocks to allow in vBlocks. No more 917 * blocks will be added if it reaches this size. 918 * \param nWindowEnd Maximum height of blocks to allow in vBlocks. No 919 * blocks will be added above this height. 920 * \param activeChain Optional pointer to a chain to compare against. If 921 * provided, any next blocks which are already contained 922 * in this chain will not be appended to vBlocks, but 923 * instead will be used to update the 924 * state->pindexLastCommonBlock pointer. 925 * \param nodeStaller Optional pointer to a NodeId variable that will receive 926 * the ID of another peer that might be causing this peer 927 * to stall. This is set to the ID of the peer which 928 * first requested the first in-flight block in the 929 * download window. It is only set if vBlocks is empty at 930 * the end of this function call and if increasing 931 * nWindowEnd by 1 would cause it to be non-empty (which 932 * indicates the download might be stalled because every 933 * block in the window is in flight and no other peer is 934 * trying to download the next block). 935 */ 936 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); 937 938 /* Multimap used to preserve insertion order */ 939 typedef std::multimap<uint256, std::pair<NodeId, std::list<QueuedBlock>::iterator>> BlockDownloadMap; 940 BlockDownloadMap mapBlocksInFlight GUARDED_BY(cs_main); 941 942 /** When our tip was last updated. */ 943 std::atomic<std::chrono::seconds> m_last_tip_update{0s}; 944 945 /** Determine whether or not a peer can request a transaction, and return it (or nullptr if not found or not allowed). */ 946 CTransactionRef FindTxForGetData(const Peer::TxRelay& tx_relay, const GenTxid& gtxid) 947 EXCLUSIVE_LOCKS_REQUIRED(!m_most_recent_block_mutex, !tx_relay.m_tx_inventory_mutex); 948 949 void ProcessGetData(CNode& pfrom, Peer& peer, const std::atomic<bool>& interruptMsgProc) 950 EXCLUSIVE_LOCKS_REQUIRED(!m_most_recent_block_mutex, peer.m_getdata_requests_mutex, NetEventsInterface::g_msgproc_mutex) 951 LOCKS_EXCLUDED(::cs_main); 952 953 /** Process a new block. Perform any post-processing housekeeping */ 954 void ProcessBlock(CNode& node, const std::shared_ptr<const CBlock>& block, bool force_processing, bool min_pow_checked); 955 956 /** Process compact block txns */ 957 void ProcessCompactBlockTxns(CNode& pfrom, Peer& peer, const BlockTransactions& block_transactions) 958 EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex, !m_most_recent_block_mutex); 959 960 /** 961 * When a peer sends us a valid block, instruct it to announce blocks to us 962 * using CMPCTBLOCK if possible by adding its nodeid to the end of 963 * lNodesAnnouncingHeaderAndIDs, and keeping that list under a certain size by 964 * removing the first element if necessary. 965 */ 966 void MaybeSetPeerAsAnnouncingHeaderAndIDs(NodeId nodeid) EXCLUSIVE_LOCKS_REQUIRED(cs_main, !m_peer_mutex); 967 968 /** Stack of nodes which we have set to announce using compact blocks */ 969 std::list<NodeId> lNodesAnnouncingHeaderAndIDs GUARDED_BY(cs_main); 970 971 /** Number of peers from which we're downloading blocks. */ 972 int m_peers_downloading_from GUARDED_BY(cs_main) = 0; 973 974 void AddToCompactExtraTransactions(const CTransactionRef& tx) EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex); 975 976 /** Orphan/conflicted/etc transactions that are kept for compact block reconstruction. 977 * The last -blockreconstructionextratxn/DEFAULT_BLOCK_RECONSTRUCTION_EXTRA_TXN of 978 * these are kept in a ring buffer */ 979 std::vector<std::pair<Wtxid, CTransactionRef>> vExtraTxnForCompact GUARDED_BY(g_msgproc_mutex); 980 /** Offset into vExtraTxnForCompact to insert the next tx */ 981 size_t vExtraTxnForCompactIt GUARDED_BY(g_msgproc_mutex) = 0; 982 983 /** Check whether the last unknown block a peer advertised is not yet known. */ 984 void ProcessBlockAvailability(NodeId nodeid) EXCLUSIVE_LOCKS_REQUIRED(cs_main); 985 /** Update tracking information about which blocks a peer is assumed to have. */ 986 void UpdateBlockAvailability(NodeId nodeid, const uint256& hash) EXCLUSIVE_LOCKS_REQUIRED(cs_main); 987 bool CanDirectFetch() EXCLUSIVE_LOCKS_REQUIRED(cs_main); 988 989 /** 990 * Estimates the distance, in blocks, between the best-known block and the network chain tip. 991 * Utilizes the best-block time and the chainparams blocks spacing to approximate it. 992 */ 993 int64_t ApproximateBestBlockDepth() const; 994 995 /** 996 * To prevent fingerprinting attacks, only send blocks/headers outside of 997 * the active chain if they are no more than a month older (both in time, 998 * and in best equivalent proof of work) than the best header chain we know 999 * about and we fully-validated them at some point. 1000 */ 1001 bool BlockRequestAllowed(const CBlockIndex* pindex) EXCLUSIVE_LOCKS_REQUIRED(cs_main); 1002 bool AlreadyHaveBlock(const uint256& block_hash) EXCLUSIVE_LOCKS_REQUIRED(cs_main); 1003 void ProcessGetBlockData(CNode& pfrom, Peer& peer, const CInv& inv) 1004 EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex, !m_most_recent_block_mutex); 1005 1006 /** 1007 * Validation logic for compact filters request handling. 1008 * 1009 * May disconnect from the peer in the case of a bad request. 1010 * 1011 * @param[in] node The node that we received the request from 1012 * @param[in] peer The peer that we received the request from 1013 * @param[in] filter_type The filter type the request is for. Must be basic filters. 1014 * @param[in] start_height The start height for the request 1015 * @param[in] stop_hash The stop_hash for the request 1016 * @param[in] max_height_diff The maximum number of items permitted to request, as specified in BIP 157 1017 * @param[out] stop_index The CBlockIndex for the stop_hash block, if the request can be serviced. 1018 * @param[out] filter_index The filter index, if the request can be serviced. 1019 * @return True if the request can be serviced. 1020 */ 1021 bool PrepareBlockFilterRequest(CNode& node, Peer& peer, 1022 BlockFilterType filter_type, uint32_t start_height, 1023 const uint256& stop_hash, uint32_t max_height_diff, 1024 const CBlockIndex*& stop_index, 1025 BlockFilterIndex*& filter_index); 1026 1027 /** 1028 * Handle a cfilters request. 1029 * 1030 * May disconnect from the peer in the case of a bad request. 1031 * 1032 * @param[in] node The node that we received the request from 1033 * @param[in] peer The peer that we received the request from 1034 * @param[in] vRecv The raw message received 1035 */ 1036 void ProcessGetCFilters(CNode& node, Peer& peer, DataStream& vRecv); 1037 1038 /** 1039 * Handle a cfheaders request. 1040 * 1041 * May disconnect from the peer in the case of a bad request. 1042 * 1043 * @param[in] node The node that we received the request from 1044 * @param[in] peer The peer that we received the request from 1045 * @param[in] vRecv The raw message received 1046 */ 1047 void ProcessGetCFHeaders(CNode& node, Peer& peer, DataStream& vRecv); 1048 1049 /** 1050 * Handle a getcfcheckpt request. 1051 * 1052 * May disconnect from the peer in the case of a bad request. 1053 * 1054 * @param[in] node The node that we received the request from 1055 * @param[in] peer The peer that we received the request from 1056 * @param[in] vRecv The raw message received 1057 */ 1058 void ProcessGetCFCheckPt(CNode& node, Peer& peer, DataStream& vRecv); 1059 1060 /** Checks if address relay is permitted with peer. If needed, initializes 1061 * the m_addr_known bloom filter and sets m_addr_relay_enabled to true. 1062 * 1063 * @return True if address relay is enabled with peer 1064 * False if address relay is disallowed 1065 */ 1066 bool SetupAddressRelay(const CNode& node, Peer& peer) EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex); 1067 1068 void AddAddressKnown(Peer& peer, const CAddress& addr) EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex); 1069 void PushAddress(Peer& peer, const CAddress& addr) EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex); 1070 1071 void LogBlockHeader(const CBlockIndex& index, const CNode& peer, bool via_compact_block); 1072 }; 1073 1074 const CNodeState* PeerManagerImpl::State(NodeId pnode) const 1075 { 1076 std::map<NodeId, CNodeState>::const_iterator it = m_node_states.find(pnode); 1077 if (it == m_node_states.end()) 1078 return nullptr; 1079 return &it->second; 1080 } 1081 1082 CNodeState* PeerManagerImpl::State(NodeId pnode) 1083 { 1084 return const_cast<CNodeState*>(std::as_const(*this).State(pnode)); 1085 } 1086 1087 /** 1088 * Whether the peer supports the address. For example, a peer that does not 1089 * implement BIP155 cannot receive Tor v3 addresses because it requires 1090 * ADDRv2 (BIP155) encoding. 1091 */ 1092 static bool IsAddrCompatible(const Peer& peer, const CAddress& addr) 1093 { 1094 return peer.m_wants_addrv2 || addr.IsAddrV1Compatible(); 1095 } 1096 1097 void PeerManagerImpl::AddAddressKnown(Peer& peer, const CAddress& addr) 1098 { 1099 assert(peer.m_addr_known); 1100 peer.m_addr_known->insert(addr.GetKey()); 1101 } 1102 1103 void PeerManagerImpl::PushAddress(Peer& peer, const CAddress& addr) 1104 { 1105 // Known checking here is only to save space from duplicates. 1106 // Before sending, we'll filter it again for known addresses that were 1107 // added after addresses were pushed. 1108 assert(peer.m_addr_known); 1109 if (addr.IsValid() && !peer.m_addr_known->contains(addr.GetKey()) && IsAddrCompatible(peer, addr)) { 1110 if (peer.m_addrs_to_send.size() >= MAX_ADDR_TO_SEND) { 1111 peer.m_addrs_to_send[m_rng.randrange(peer.m_addrs_to_send.size())] = addr; 1112 } else { 1113 peer.m_addrs_to_send.push_back(addr); 1114 } 1115 } 1116 } 1117 1118 static void AddKnownTx(Peer& peer, const uint256& hash) 1119 { 1120 auto tx_relay = peer.GetTxRelay(); 1121 if (!tx_relay) return; 1122 1123 LOCK(tx_relay->m_tx_inventory_mutex); 1124 tx_relay->m_tx_inventory_known_filter.insert(hash); 1125 } 1126 1127 /** Whether this peer can serve us blocks. */ 1128 static bool CanServeBlocks(const Peer& peer) 1129 { 1130 return peer.m_their_services & (NODE_NETWORK|NODE_NETWORK_LIMITED); 1131 } 1132 1133 /** Whether this peer can only serve limited recent blocks (e.g. because 1134 * it prunes old blocks) */ 1135 static bool IsLimitedPeer(const Peer& peer) 1136 { 1137 return (!(peer.m_their_services & NODE_NETWORK) && 1138 (peer.m_their_services & NODE_NETWORK_LIMITED)); 1139 } 1140 1141 /** Whether this peer can serve us witness data */ 1142 static bool CanServeWitnesses(const Peer& peer) 1143 { 1144 return peer.m_their_services & NODE_WITNESS; 1145 } 1146 1147 std::chrono::microseconds PeerManagerImpl::NextInvToInbounds(std::chrono::microseconds now, 1148 std::chrono::seconds average_interval, 1149 uint64_t network_key) 1150 { 1151 auto [it, inserted] = m_next_inv_to_inbounds_per_network_key.try_emplace(network_key, 0us); 1152 auto& timer{it->second}; 1153 if (timer < now) { 1154 timer = now + m_rng.rand_exp_duration(average_interval); 1155 } 1156 return timer; 1157 } 1158 1159 bool PeerManagerImpl::IsBlockRequested(const uint256& hash) 1160 { 1161 return mapBlocksInFlight.count(hash); 1162 } 1163 1164 bool PeerManagerImpl::IsBlockRequestedFromOutbound(const uint256& hash) 1165 { 1166 for (auto range = mapBlocksInFlight.equal_range(hash); range.first != range.second; range.first++) { 1167 auto [nodeid, block_it] = range.first->second; 1168 PeerRef peer{GetPeerRef(nodeid)}; 1169 if (peer && !peer->m_is_inbound) return true; 1170 } 1171 1172 return false; 1173 } 1174 1175 void PeerManagerImpl::RemoveBlockRequest(const uint256& hash, std::optional<NodeId> from_peer) 1176 { 1177 auto range = mapBlocksInFlight.equal_range(hash); 1178 if (range.first == range.second) { 1179 // Block was not requested from any peer 1180 return; 1181 } 1182 1183 // We should not have requested too many of this block 1184 Assume(mapBlocksInFlight.count(hash) <= MAX_CMPCTBLOCKS_INFLIGHT_PER_BLOCK); 1185 1186 while (range.first != range.second) { 1187 const auto& [node_id, list_it]{range.first->second}; 1188 1189 if (from_peer && *from_peer != node_id) { 1190 range.first++; 1191 continue; 1192 } 1193 1194 CNodeState& state = *Assert(State(node_id)); 1195 1196 if (state.vBlocksInFlight.begin() == list_it) { 1197 // First block on the queue was received, update the start download time for the next one 1198 state.m_downloading_since = std::max(state.m_downloading_since, GetTime<std::chrono::microseconds>()); 1199 } 1200 state.vBlocksInFlight.erase(list_it); 1201 1202 if (state.vBlocksInFlight.empty()) { 1203 // Last validated block on the queue for this peer was received. 1204 m_peers_downloading_from--; 1205 } 1206 state.m_stalling_since = 0us; 1207 1208 range.first = mapBlocksInFlight.erase(range.first); 1209 } 1210 } 1211 1212 bool PeerManagerImpl::BlockRequested(NodeId nodeid, const CBlockIndex& block, std::list<QueuedBlock>::iterator** pit) 1213 { 1214 const uint256& hash{block.GetBlockHash()}; 1215 1216 CNodeState *state = State(nodeid); 1217 assert(state != nullptr); 1218 1219 Assume(mapBlocksInFlight.count(hash) <= MAX_CMPCTBLOCKS_INFLIGHT_PER_BLOCK); 1220 1221 // Short-circuit most stuff in case it is from the same node 1222 for (auto range = mapBlocksInFlight.equal_range(hash); range.first != range.second; range.first++) { 1223 if (range.first->second.first == nodeid) { 1224 if (pit) { 1225 *pit = &range.first->second.second; 1226 } 1227 return false; 1228 } 1229 } 1230 1231 // Make sure it's not being fetched already from same peer. 1232 RemoveBlockRequest(hash, nodeid); 1233 1234 std::list<QueuedBlock>::iterator it = state->vBlocksInFlight.insert(state->vBlocksInFlight.end(), 1235 {&block, std::unique_ptr<PartiallyDownloadedBlock>(pit ? new PartiallyDownloadedBlock(&m_mempool) : nullptr)}); 1236 if (state->vBlocksInFlight.size() == 1) { 1237 // We're starting a block download (batch) from this peer. 1238 state->m_downloading_since = GetTime<std::chrono::microseconds>(); 1239 m_peers_downloading_from++; 1240 } 1241 auto itInFlight = mapBlocksInFlight.insert(std::make_pair(hash, std::make_pair(nodeid, it))); 1242 if (pit) { 1243 *pit = &itInFlight->second.second; 1244 } 1245 return true; 1246 } 1247 1248 void PeerManagerImpl::MaybeSetPeerAsAnnouncingHeaderAndIDs(NodeId nodeid) 1249 { 1250 AssertLockHeld(cs_main); 1251 1252 // When in -blocksonly mode, never request high-bandwidth mode from peers. Our 1253 // mempool will not contain the transactions necessary to reconstruct the 1254 // compact block. 1255 if (m_opts.ignore_incoming_txs) return; 1256 1257 CNodeState* nodestate = State(nodeid); 1258 PeerRef peer{GetPeerRef(nodeid)}; 1259 if (!nodestate || !nodestate->m_provides_cmpctblocks) { 1260 // Don't request compact blocks if the peer has not signalled support 1261 return; 1262 } 1263 1264 int num_outbound_hb_peers = 0; 1265 for (std::list<NodeId>::iterator it = lNodesAnnouncingHeaderAndIDs.begin(); it != lNodesAnnouncingHeaderAndIDs.end(); it++) { 1266 if (*it == nodeid) { 1267 lNodesAnnouncingHeaderAndIDs.erase(it); 1268 lNodesAnnouncingHeaderAndIDs.push_back(nodeid); 1269 return; 1270 } 1271 PeerRef peer_ref{GetPeerRef(*it)}; 1272 if (peer_ref && !peer_ref->m_is_inbound) ++num_outbound_hb_peers; 1273 } 1274 if (peer && peer->m_is_inbound) { 1275 // If we're adding an inbound HB peer, make sure we're not removing 1276 // our last outbound HB peer in the process. 1277 if (lNodesAnnouncingHeaderAndIDs.size() >= 3 && num_outbound_hb_peers == 1) { 1278 PeerRef remove_peer{GetPeerRef(lNodesAnnouncingHeaderAndIDs.front())}; 1279 if (remove_peer && !remove_peer->m_is_inbound) { 1280 // Put the HB outbound peer in the second slot, so that it 1281 // doesn't get removed. 1282 std::swap(lNodesAnnouncingHeaderAndIDs.front(), *std::next(lNodesAnnouncingHeaderAndIDs.begin())); 1283 } 1284 } 1285 } 1286 m_connman.ForNode(nodeid, [this](CNode* pfrom) EXCLUSIVE_LOCKS_REQUIRED(::cs_main) { 1287 AssertLockHeld(::cs_main); 1288 if (lNodesAnnouncingHeaderAndIDs.size() >= 3) { 1289 // As per BIP152, we only get 3 of our peers to announce 1290 // blocks using compact encodings. 1291 m_connman.ForNode(lNodesAnnouncingHeaderAndIDs.front(), [this](CNode* pnodeStop){ 1292 MakeAndPushMessage(*pnodeStop, NetMsgType::SENDCMPCT, /*high_bandwidth=*/false, /*version=*/CMPCTBLOCKS_VERSION); 1293 // save BIP152 bandwidth state: we select peer to be low-bandwidth 1294 pnodeStop->m_bip152_highbandwidth_to = false; 1295 return true; 1296 }); 1297 lNodesAnnouncingHeaderAndIDs.pop_front(); 1298 } 1299 MakeAndPushMessage(*pfrom, NetMsgType::SENDCMPCT, /*high_bandwidth=*/true, /*version=*/CMPCTBLOCKS_VERSION); 1300 // save BIP152 bandwidth state: we select peer to be high-bandwidth 1301 pfrom->m_bip152_highbandwidth_to = true; 1302 lNodesAnnouncingHeaderAndIDs.push_back(pfrom->GetId()); 1303 return true; 1304 }); 1305 } 1306 1307 bool PeerManagerImpl::TipMayBeStale() 1308 { 1309 AssertLockHeld(cs_main); 1310 const Consensus::Params& consensusParams = m_chainparams.GetConsensus(); 1311 if (m_last_tip_update.load() == 0s) { 1312 m_last_tip_update = GetTime<std::chrono::seconds>(); 1313 } 1314 return m_last_tip_update.load() < GetTime<std::chrono::seconds>() - std::chrono::seconds{consensusParams.nPowTargetSpacing * 3} && mapBlocksInFlight.empty(); 1315 } 1316 1317 int64_t PeerManagerImpl::ApproximateBestBlockDepth() const 1318 { 1319 return (GetTime<std::chrono::seconds>() - m_best_block_time.load()).count() / m_chainparams.GetConsensus().nPowTargetSpacing; 1320 } 1321 1322 bool PeerManagerImpl::CanDirectFetch() 1323 { 1324 return m_chainman.ActiveChain().Tip()->Time() > NodeClock::now() - m_chainparams.GetConsensus().PowTargetSpacing() * 20; 1325 } 1326 1327 static bool PeerHasHeader(CNodeState *state, const CBlockIndex *pindex) EXCLUSIVE_LOCKS_REQUIRED(cs_main) 1328 { 1329 if (state->pindexBestKnownBlock && pindex == state->pindexBestKnownBlock->GetAncestor(pindex->nHeight)) 1330 return true; 1331 if (state->pindexBestHeaderSent && pindex == state->pindexBestHeaderSent->GetAncestor(pindex->nHeight)) 1332 return true; 1333 return false; 1334 } 1335 1336 void PeerManagerImpl::ProcessBlockAvailability(NodeId nodeid) { 1337 CNodeState *state = State(nodeid); 1338 assert(state != nullptr); 1339 1340 if (!state->hashLastUnknownBlock.IsNull()) { 1341 const CBlockIndex* pindex = m_chainman.m_blockman.LookupBlockIndex(state->hashLastUnknownBlock); 1342 if (pindex && pindex->nChainWork > 0) { 1343 if (state->pindexBestKnownBlock == nullptr || pindex->nChainWork >= state->pindexBestKnownBlock->nChainWork) { 1344 state->pindexBestKnownBlock = pindex; 1345 } 1346 state->hashLastUnknownBlock.SetNull(); 1347 } 1348 } 1349 } 1350 1351 void PeerManagerImpl::UpdateBlockAvailability(NodeId nodeid, const uint256 &hash) { 1352 CNodeState *state = State(nodeid); 1353 assert(state != nullptr); 1354 1355 ProcessBlockAvailability(nodeid); 1356 1357 const CBlockIndex* pindex = m_chainman.m_blockman.LookupBlockIndex(hash); 1358 if (pindex && pindex->nChainWork > 0) { 1359 // An actually better block was announced. 1360 if (state->pindexBestKnownBlock == nullptr || pindex->nChainWork >= state->pindexBestKnownBlock->nChainWork) { 1361 state->pindexBestKnownBlock = pindex; 1362 } 1363 } else { 1364 // An unknown block was announced; just assume that the latest one is the best one. 1365 state->hashLastUnknownBlock = hash; 1366 } 1367 } 1368 1369 // Logic for calculating which blocks to download from a given peer, given our current tip. 1370 void PeerManagerImpl::FindNextBlocksToDownload(const Peer& peer, unsigned int count, std::vector<const CBlockIndex*>& vBlocks, NodeId& nodeStaller) 1371 { 1372 if (count == 0) 1373 return; 1374 1375 vBlocks.reserve(vBlocks.size() + count); 1376 CNodeState *state = State(peer.m_id); 1377 assert(state != nullptr); 1378 1379 // Make sure pindexBestKnownBlock is up to date, we'll need it. 1380 ProcessBlockAvailability(peer.m_id); 1381 1382 if (state->pindexBestKnownBlock == nullptr || state->pindexBestKnownBlock->nChainWork < m_chainman.ActiveChain().Tip()->nChainWork || state->pindexBestKnownBlock->nChainWork < m_chainman.MinimumChainWork()) { 1383 // This peer has nothing interesting. 1384 return; 1385 } 1386 1387 // When we sync with AssumeUtxo and discover the snapshot is not in the peer's best chain, abort: 1388 // We can't reorg to this chain due to missing undo data until the background sync has finished, 1389 // so downloading blocks from it would be futile. 1390 const CBlockIndex* snap_base{m_chainman.GetSnapshotBaseBlock()}; 1391 if (snap_base && state->pindexBestKnownBlock->GetAncestor(snap_base->nHeight) != snap_base) { 1392 LogDebug(BCLog::NET, "Not downloading blocks from peer=%d, which doesn't have the snapshot block in its best chain.\n", peer.m_id); 1393 return; 1394 } 1395 1396 // Determine the forking point between the peer's chain and our chain: 1397 // pindexLastCommonBlock is required to be an ancestor of pindexBestKnownBlock, and will be used as a starting point. 1398 // It is being set to the fork point between the peer's best known block and the current tip, unless it is already set to 1399 // an ancestor with more work than the fork point. 1400 auto fork_point = LastCommonAncestor(state->pindexBestKnownBlock, m_chainman.ActiveTip()); 1401 if (state->pindexLastCommonBlock == nullptr || 1402 fork_point->nChainWork > state->pindexLastCommonBlock->nChainWork || 1403 state->pindexBestKnownBlock->GetAncestor(state->pindexLastCommonBlock->nHeight) != state->pindexLastCommonBlock) { 1404 state->pindexLastCommonBlock = fork_point; 1405 } 1406 if (state->pindexLastCommonBlock == state->pindexBestKnownBlock) 1407 return; 1408 1409 const CBlockIndex *pindexWalk = state->pindexLastCommonBlock; 1410 // Never fetch further than the best block we know the peer has, or more than BLOCK_DOWNLOAD_WINDOW + 1 beyond the last 1411 // linked block we have in common with this peer. The +1 is so we can detect stalling, namely if we would be able to 1412 // download that next block if the window were 1 larger. 1413 int nWindowEnd = state->pindexLastCommonBlock->nHeight + BLOCK_DOWNLOAD_WINDOW; 1414 1415 FindNextBlocks(vBlocks, peer, state, pindexWalk, count, nWindowEnd, &m_chainman.ActiveChain(), &nodeStaller); 1416 } 1417 1418 void PeerManagerImpl::TryDownloadingHistoricalBlocks(const Peer& peer, unsigned int count, std::vector<const CBlockIndex*>& vBlocks, const CBlockIndex *from_tip, const CBlockIndex* target_block) 1419 { 1420 Assert(from_tip); 1421 Assert(target_block); 1422 1423 if (vBlocks.size() >= count) { 1424 return; 1425 } 1426 1427 vBlocks.reserve(count); 1428 CNodeState *state = Assert(State(peer.m_id)); 1429 1430 if (state->pindexBestKnownBlock == nullptr || state->pindexBestKnownBlock->GetAncestor(target_block->nHeight) != target_block) { 1431 // This peer can't provide us the complete series of blocks leading up to the 1432 // assumeutxo snapshot base. 1433 // 1434 // Presumably this peer's chain has less work than our ActiveChain()'s tip, or else we 1435 // will eventually crash when we try to reorg to it. Let other logic 1436 // deal with whether we disconnect this peer. 1437 // 1438 // TODO at some point in the future, we might choose to request what blocks 1439 // this peer does have from the historical chain, despite it not having a 1440 // complete history beneath the snapshot base. 1441 return; 1442 } 1443 1444 FindNextBlocks(vBlocks, peer, state, from_tip, count, std::min<int>(from_tip->nHeight + BLOCK_DOWNLOAD_WINDOW, target_block->nHeight)); 1445 } 1446 1447 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) 1448 { 1449 std::vector<const CBlockIndex*> vToFetch; 1450 int nMaxHeight = std::min<int>(state->pindexBestKnownBlock->nHeight, nWindowEnd + 1); 1451 bool is_limited_peer = IsLimitedPeer(peer); 1452 NodeId waitingfor = -1; 1453 while (pindexWalk->nHeight < nMaxHeight) { 1454 // Read up to 128 (or more, if more blocks than that are needed) successors of pindexWalk (towards 1455 // pindexBestKnownBlock) into vToFetch. We fetch 128, because CBlockIndex::GetAncestor may be as expensive 1456 // as iterating over ~100 CBlockIndex* entries anyway. 1457 int nToFetch = std::min(nMaxHeight - pindexWalk->nHeight, std::max<int>(count - vBlocks.size(), 128)); 1458 vToFetch.resize(nToFetch); 1459 pindexWalk = state->pindexBestKnownBlock->GetAncestor(pindexWalk->nHeight + nToFetch); 1460 vToFetch[nToFetch - 1] = pindexWalk; 1461 for (unsigned int i = nToFetch - 1; i > 0; i--) { 1462 vToFetch[i - 1] = vToFetch[i]->pprev; 1463 } 1464 1465 // Iterate over those blocks in vToFetch (in forward direction), adding the ones that 1466 // are not yet downloaded and not in flight to vBlocks. In the meantime, update 1467 // pindexLastCommonBlock as long as all ancestors are already downloaded, or if it's 1468 // already part of our chain (and therefore don't need it even if pruned). 1469 for (const CBlockIndex* pindex : vToFetch) { 1470 if (!pindex->IsValid(BLOCK_VALID_TREE)) { 1471 // We consider the chain that this peer is on invalid. 1472 return; 1473 } 1474 1475 if (!CanServeWitnesses(peer) && DeploymentActiveAt(*pindex, m_chainman, Consensus::DEPLOYMENT_SEGWIT)) { 1476 // We wouldn't download this block or its descendants from this peer. 1477 return; 1478 } 1479 1480 if (pindex->nStatus & BLOCK_HAVE_DATA || (activeChain && activeChain->Contains(pindex))) { 1481 if (activeChain && pindex->HaveNumChainTxs()) { 1482 state->pindexLastCommonBlock = pindex; 1483 } 1484 continue; 1485 } 1486 1487 // Is block in-flight? 1488 if (IsBlockRequested(pindex->GetBlockHash())) { 1489 if (waitingfor == -1) { 1490 // This is the first already-in-flight block. 1491 waitingfor = mapBlocksInFlight.lower_bound(pindex->GetBlockHash())->second.first; 1492 } 1493 continue; 1494 } 1495 1496 // The block is not already downloaded, and not yet in flight. 1497 if (pindex->nHeight > nWindowEnd) { 1498 // We reached the end of the window. 1499 if (vBlocks.size() == 0 && waitingfor != peer.m_id) { 1500 // We aren't able to fetch anything, but we would be if the download window was one larger. 1501 if (nodeStaller) *nodeStaller = waitingfor; 1502 } 1503 return; 1504 } 1505 1506 // Don't request blocks that go further than what limited peers can provide 1507 if (is_limited_peer && (state->pindexBestKnownBlock->nHeight - pindex->nHeight >= static_cast<int>(NODE_NETWORK_LIMITED_MIN_BLOCKS) - 2 /* two blocks buffer for possible races */)) { 1508 continue; 1509 } 1510 1511 vBlocks.push_back(pindex); 1512 if (vBlocks.size() == count) { 1513 return; 1514 } 1515 } 1516 } 1517 } 1518 1519 } // namespace 1520 1521 void PeerManagerImpl::PushNodeVersion(CNode& pnode, const Peer& peer) 1522 { 1523 uint64_t my_services{peer.m_our_services}; 1524 const int64_t nTime{count_seconds(GetTime<std::chrono::seconds>())}; 1525 uint64_t nonce = pnode.GetLocalNonce(); 1526 const int nNodeStartingHeight{m_best_height}; 1527 NodeId nodeid = pnode.GetId(); 1528 CAddress addr = pnode.addr; 1529 1530 CService addr_you = addr.IsRoutable() && !IsProxy(addr) && addr.IsAddrV1Compatible() ? addr : CService(); 1531 uint64_t your_services{addr.nServices}; 1532 1533 const bool tx_relay{!RejectIncomingTxs(pnode)}; 1534 MakeAndPushMessage(pnode, NetMsgType::VERSION, PROTOCOL_VERSION, my_services, nTime, 1535 your_services, CNetAddr::V1(addr_you), // Together the pre-version-31402 serialization of CAddress "addrYou" (without nTime) 1536 my_services, CNetAddr::V1(CService{}), // Together the pre-version-31402 serialization of CAddress "addrMe" (without nTime) 1537 nonce, strSubVersion, nNodeStartingHeight, tx_relay); 1538 1539 if (fLogIPs) { 1540 LogDebug(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); 1541 } else { 1542 LogDebug(BCLog::NET, "send version message: version %d, blocks=%d, txrelay=%d, peer=%d\n", PROTOCOL_VERSION, nNodeStartingHeight, tx_relay, nodeid); 1543 } 1544 } 1545 1546 void PeerManagerImpl::UpdateLastBlockAnnounceTime(NodeId node, int64_t time_in_seconds) 1547 { 1548 LOCK(cs_main); 1549 CNodeState *state = State(node); 1550 if (state) state->m_last_block_announcement = time_in_seconds; 1551 } 1552 1553 void PeerManagerImpl::InitializeNode(const CNode& node, ServiceFlags our_services) 1554 { 1555 NodeId nodeid = node.GetId(); 1556 { 1557 LOCK(cs_main); // For m_node_states 1558 m_node_states.try_emplace(m_node_states.end(), nodeid); 1559 } 1560 WITH_LOCK(m_tx_download_mutex, m_txdownloadman.CheckIsEmpty(nodeid)); 1561 1562 if (NetPermissions::HasFlag(node.m_permission_flags, NetPermissionFlags::BloomFilter)) { 1563 our_services = static_cast<ServiceFlags>(our_services | NODE_BLOOM); 1564 } 1565 1566 PeerRef peer = std::make_shared<Peer>(nodeid, our_services, node.IsInboundConn()); 1567 { 1568 LOCK(m_peer_mutex); 1569 m_peer_map.emplace_hint(m_peer_map.end(), nodeid, peer); 1570 } 1571 } 1572 1573 void PeerManagerImpl::ReattemptInitialBroadcast(CScheduler& scheduler) 1574 { 1575 std::set<Txid> unbroadcast_txids = m_mempool.GetUnbroadcastTxs(); 1576 1577 for (const auto& txid : unbroadcast_txids) { 1578 CTransactionRef tx = m_mempool.get(txid); 1579 1580 if (tx != nullptr) { 1581 RelayTransaction(txid, tx->GetWitnessHash()); 1582 } else { 1583 m_mempool.RemoveUnbroadcastTx(txid, true); 1584 } 1585 } 1586 1587 // Schedule next run for 10-15 minutes in the future. 1588 // We add randomness on every cycle to avoid the possibility of P2P fingerprinting. 1589 const auto delta = 10min + FastRandomContext().randrange<std::chrono::milliseconds>(5min); 1590 scheduler.scheduleFromNow([&] { ReattemptInitialBroadcast(scheduler); }, delta); 1591 } 1592 1593 void PeerManagerImpl::FinalizeNode(const CNode& node) 1594 { 1595 NodeId nodeid = node.GetId(); 1596 { 1597 LOCK(cs_main); 1598 { 1599 // We remove the PeerRef from g_peer_map here, but we don't always 1600 // destruct the Peer. Sometimes another thread is still holding a 1601 // PeerRef, so the refcount is >= 1. Be careful not to do any 1602 // processing here that assumes Peer won't be changed before it's 1603 // destructed. 1604 PeerRef peer = RemovePeer(nodeid); 1605 assert(peer != nullptr); 1606 m_wtxid_relay_peers -= peer->m_wtxid_relay; 1607 assert(m_wtxid_relay_peers >= 0); 1608 } 1609 CNodeState *state = State(nodeid); 1610 assert(state != nullptr); 1611 1612 if (state->fSyncStarted) 1613 nSyncStarted--; 1614 1615 for (const QueuedBlock& entry : state->vBlocksInFlight) { 1616 auto range = mapBlocksInFlight.equal_range(entry.pindex->GetBlockHash()); 1617 while (range.first != range.second) { 1618 auto [node_id, list_it] = range.first->second; 1619 if (node_id != nodeid) { 1620 range.first++; 1621 } else { 1622 range.first = mapBlocksInFlight.erase(range.first); 1623 } 1624 } 1625 } 1626 { 1627 LOCK(m_tx_download_mutex); 1628 m_txdownloadman.DisconnectedPeer(nodeid); 1629 } 1630 if (m_txreconciliation) m_txreconciliation->ForgetPeer(nodeid); 1631 m_num_preferred_download_peers -= state->fPreferredDownload; 1632 m_peers_downloading_from -= (!state->vBlocksInFlight.empty()); 1633 assert(m_peers_downloading_from >= 0); 1634 m_outbound_peers_with_protect_from_disconnect -= state->m_chain_sync.m_protect; 1635 assert(m_outbound_peers_with_protect_from_disconnect >= 0); 1636 1637 m_node_states.erase(nodeid); 1638 1639 if (m_node_states.empty()) { 1640 // Do a consistency check after the last peer is removed. 1641 assert(mapBlocksInFlight.empty()); 1642 assert(m_num_preferred_download_peers == 0); 1643 assert(m_peers_downloading_from == 0); 1644 assert(m_outbound_peers_with_protect_from_disconnect == 0); 1645 assert(m_wtxid_relay_peers == 0); 1646 WITH_LOCK(m_tx_download_mutex, m_txdownloadman.CheckIsEmpty()); 1647 } 1648 } // cs_main 1649 if (node.fSuccessfullyConnected && 1650 !node.IsBlockOnlyConn() && !node.IsInboundConn()) { 1651 // Only change visible addrman state for full outbound peers. We don't 1652 // call Connected() for feeler connections since they don't have 1653 // fSuccessfullyConnected set. 1654 m_addrman.Connected(node.addr); 1655 } 1656 { 1657 LOCK(m_headers_presync_mutex); 1658 m_headers_presync_stats.erase(nodeid); 1659 } 1660 LogDebug(BCLog::NET, "Cleared nodestate for peer=%d\n", nodeid); 1661 } 1662 1663 bool PeerManagerImpl::HasAllDesirableServiceFlags(ServiceFlags services) const 1664 { 1665 // Shortcut for (services & GetDesirableServiceFlags(services)) == GetDesirableServiceFlags(services) 1666 return !(GetDesirableServiceFlags(services) & (~services)); 1667 } 1668 1669 ServiceFlags PeerManagerImpl::GetDesirableServiceFlags(ServiceFlags services) const 1670 { 1671 if (services & NODE_NETWORK_LIMITED) { 1672 // Limited peers are desirable when we are close to the tip. 1673 if (ApproximateBestBlockDepth() < NODE_NETWORK_LIMITED_ALLOW_CONN_BLOCKS) { 1674 return ServiceFlags(NODE_NETWORK_LIMITED | NODE_WITNESS); 1675 } 1676 } 1677 return ServiceFlags(NODE_NETWORK | NODE_WITNESS); 1678 } 1679 1680 PeerRef PeerManagerImpl::GetPeerRef(NodeId id) const 1681 { 1682 LOCK(m_peer_mutex); 1683 auto it = m_peer_map.find(id); 1684 return it != m_peer_map.end() ? it->second : nullptr; 1685 } 1686 1687 PeerRef PeerManagerImpl::RemovePeer(NodeId id) 1688 { 1689 PeerRef ret; 1690 LOCK(m_peer_mutex); 1691 auto it = m_peer_map.find(id); 1692 if (it != m_peer_map.end()) { 1693 ret = std::move(it->second); 1694 m_peer_map.erase(it); 1695 } 1696 return ret; 1697 } 1698 1699 bool PeerManagerImpl::GetNodeStateStats(NodeId nodeid, CNodeStateStats& stats) const 1700 { 1701 { 1702 LOCK(cs_main); 1703 const CNodeState* state = State(nodeid); 1704 if (state == nullptr) 1705 return false; 1706 stats.nSyncHeight = state->pindexBestKnownBlock ? state->pindexBestKnownBlock->nHeight : -1; 1707 stats.nCommonHeight = state->pindexLastCommonBlock ? state->pindexLastCommonBlock->nHeight : -1; 1708 for (const QueuedBlock& queue : state->vBlocksInFlight) { 1709 if (queue.pindex) 1710 stats.vHeightInFlight.push_back(queue.pindex->nHeight); 1711 } 1712 } 1713 1714 PeerRef peer = GetPeerRef(nodeid); 1715 if (peer == nullptr) return false; 1716 stats.their_services = peer->m_their_services; 1717 stats.m_starting_height = peer->m_starting_height; 1718 // It is common for nodes with good ping times to suddenly become lagged, 1719 // due to a new block arriving or other large transfer. 1720 // Merely reporting pingtime might fool the caller into thinking the node was still responsive, 1721 // since pingtime does not update until the ping is complete, which might take a while. 1722 // So, if a ping is taking an unusually long time in flight, 1723 // the caller can immediately detect that this is happening. 1724 auto ping_wait{0us}; 1725 if ((0 != peer->m_ping_nonce_sent) && (0 != peer->m_ping_start.load().count())) { 1726 ping_wait = GetTime<std::chrono::microseconds>() - peer->m_ping_start.load(); 1727 } 1728 1729 if (auto tx_relay = peer->GetTxRelay(); tx_relay != nullptr) { 1730 stats.m_relay_txs = WITH_LOCK(tx_relay->m_bloom_filter_mutex, return tx_relay->m_relay_txs); 1731 stats.m_fee_filter_received = tx_relay->m_fee_filter_received.load(); 1732 LOCK(tx_relay->m_tx_inventory_mutex); 1733 stats.m_last_inv_seq = tx_relay->m_last_inv_sequence; 1734 stats.m_inv_to_send = tx_relay->m_tx_inventory_to_send.size(); 1735 } else { 1736 stats.m_relay_txs = false; 1737 stats.m_fee_filter_received = 0; 1738 stats.m_inv_to_send = 0; 1739 } 1740 1741 stats.m_ping_wait = ping_wait; 1742 stats.m_addr_processed = peer->m_addr_processed.load(); 1743 stats.m_addr_rate_limited = peer->m_addr_rate_limited.load(); 1744 stats.m_addr_relay_enabled = peer->m_addr_relay_enabled.load(); 1745 { 1746 LOCK(peer->m_headers_sync_mutex); 1747 if (peer->m_headers_sync) { 1748 stats.presync_height = peer->m_headers_sync->GetPresyncHeight(); 1749 } 1750 } 1751 stats.time_offset = peer->m_time_offset; 1752 1753 return true; 1754 } 1755 1756 std::vector<node::TxOrphanage::OrphanInfo> PeerManagerImpl::GetOrphanTransactions() 1757 { 1758 LOCK(m_tx_download_mutex); 1759 return m_txdownloadman.GetOrphanTransactions(); 1760 } 1761 1762 PeerManagerInfo PeerManagerImpl::GetInfo() const 1763 { 1764 return PeerManagerInfo{ 1765 .median_outbound_time_offset = m_outbound_time_offsets.Median(), 1766 .ignores_incoming_txs = m_opts.ignore_incoming_txs, 1767 }; 1768 } 1769 1770 void PeerManagerImpl::AddToCompactExtraTransactions(const CTransactionRef& tx) 1771 { 1772 if (m_opts.max_extra_txs <= 0) 1773 return; 1774 if (!vExtraTxnForCompact.size()) 1775 vExtraTxnForCompact.resize(m_opts.max_extra_txs); 1776 vExtraTxnForCompact[vExtraTxnForCompactIt] = std::make_pair(tx->GetWitnessHash(), tx); 1777 vExtraTxnForCompactIt = (vExtraTxnForCompactIt + 1) % m_opts.max_extra_txs; 1778 } 1779 1780 void PeerManagerImpl::Misbehaving(Peer& peer, const std::string& message) 1781 { 1782 LOCK(peer.m_misbehavior_mutex); 1783 1784 const std::string message_prefixed = message.empty() ? "" : (": " + message); 1785 peer.m_should_discourage = true; 1786 LogDebug(BCLog::NET, "Misbehaving: peer=%d%s\n", peer.m_id, message_prefixed); 1787 TRACEPOINT(net, misbehaving_connection, 1788 peer.m_id, 1789 message.c_str() 1790 ); 1791 } 1792 1793 void PeerManagerImpl::MaybePunishNodeForBlock(NodeId nodeid, const BlockValidationState& state, 1794 bool via_compact_block, const std::string& message) 1795 { 1796 PeerRef peer{GetPeerRef(nodeid)}; 1797 switch (state.GetResult()) { 1798 case BlockValidationResult::BLOCK_RESULT_UNSET: 1799 break; 1800 case BlockValidationResult::BLOCK_HEADER_LOW_WORK: 1801 // We didn't try to process the block because the header chain may have 1802 // too little work. 1803 break; 1804 // The node is providing invalid data: 1805 case BlockValidationResult::BLOCK_CONSENSUS: 1806 case BlockValidationResult::BLOCK_MUTATED: 1807 if (!via_compact_block) { 1808 if (peer) Misbehaving(*peer, message); 1809 return; 1810 } 1811 break; 1812 case BlockValidationResult::BLOCK_CACHED_INVALID: 1813 { 1814 // Discourage outbound (but not inbound) peers if on an invalid chain. 1815 // Exempt HB compact block peers. Manual connections are always protected from discouragement. 1816 if (peer && !via_compact_block && !peer->m_is_inbound) { 1817 if (peer) Misbehaving(*peer, message); 1818 return; 1819 } 1820 break; 1821 } 1822 case BlockValidationResult::BLOCK_INVALID_HEADER: 1823 case BlockValidationResult::BLOCK_INVALID_PREV: 1824 if (peer) Misbehaving(*peer, message); 1825 return; 1826 // Conflicting (but not necessarily invalid) data or different policy: 1827 case BlockValidationResult::BLOCK_MISSING_PREV: 1828 if (peer) Misbehaving(*peer, message); 1829 return; 1830 case BlockValidationResult::BLOCK_TIME_FUTURE: 1831 break; 1832 } 1833 if (message != "") { 1834 LogDebug(BCLog::NET, "peer=%d: %s\n", nodeid, message); 1835 } 1836 } 1837 1838 bool PeerManagerImpl::BlockRequestAllowed(const CBlockIndex* pindex) 1839 { 1840 AssertLockHeld(cs_main); 1841 if (m_chainman.ActiveChain().Contains(pindex)) return true; 1842 return pindex->IsValid(BLOCK_VALID_SCRIPTS) && (m_chainman.m_best_header != nullptr) && 1843 (m_chainman.m_best_header->GetBlockTime() - pindex->GetBlockTime() < STALE_RELAY_AGE_LIMIT) && 1844 (GetBlockProofEquivalentTime(*m_chainman.m_best_header, *pindex, *m_chainman.m_best_header, m_chainparams.GetConsensus()) < STALE_RELAY_AGE_LIMIT); 1845 } 1846 1847 std::optional<std::string> PeerManagerImpl::FetchBlock(NodeId peer_id, const CBlockIndex& block_index) 1848 { 1849 if (m_chainman.m_blockman.LoadingBlocks()) return "Loading blocks ..."; 1850 1851 // Ensure this peer exists and hasn't been disconnected 1852 PeerRef peer = GetPeerRef(peer_id); 1853 if (peer == nullptr) return "Peer does not exist"; 1854 1855 // Ignore pre-segwit peers 1856 if (!CanServeWitnesses(*peer)) return "Pre-SegWit peer"; 1857 1858 LOCK(cs_main); 1859 1860 // Forget about all prior requests 1861 RemoveBlockRequest(block_index.GetBlockHash(), std::nullopt); 1862 1863 // Mark block as in-flight 1864 if (!BlockRequested(peer_id, block_index)) return "Already requested from this peer"; 1865 1866 // Construct message to request the block 1867 const uint256& hash{block_index.GetBlockHash()}; 1868 std::vector<CInv> invs{CInv(MSG_BLOCK | MSG_WITNESS_FLAG, hash)}; 1869 1870 // Send block request message to the peer 1871 bool success = m_connman.ForNode(peer_id, [this, &invs](CNode* node) { 1872 this->MakeAndPushMessage(*node, NetMsgType::GETDATA, invs); 1873 return true; 1874 }); 1875 1876 if (!success) return "Peer not fully connected"; 1877 1878 LogDebug(BCLog::NET, "Requesting block %s from peer=%d\n", 1879 hash.ToString(), peer_id); 1880 return std::nullopt; 1881 } 1882 1883 std::unique_ptr<PeerManager> PeerManager::make(CConnman& connman, AddrMan& addrman, 1884 BanMan* banman, ChainstateManager& chainman, 1885 CTxMemPool& pool, node::Warnings& warnings, Options opts) 1886 { 1887 return std::make_unique<PeerManagerImpl>(connman, addrman, banman, chainman, pool, warnings, opts); 1888 } 1889 1890 PeerManagerImpl::PeerManagerImpl(CConnman& connman, AddrMan& addrman, 1891 BanMan* banman, ChainstateManager& chainman, 1892 CTxMemPool& pool, node::Warnings& warnings, Options opts) 1893 : m_rng{opts.deterministic_rng}, 1894 m_fee_filter_rounder{CFeeRate{DEFAULT_MIN_RELAY_TX_FEE}, m_rng}, 1895 m_chainparams(chainman.GetParams()), 1896 m_connman(connman), 1897 m_addrman(addrman), 1898 m_banman(banman), 1899 m_chainman(chainman), 1900 m_mempool(pool), 1901 m_txdownloadman(node::TxDownloadOptions{pool, m_rng, opts.deterministic_rng}), 1902 m_warnings{warnings}, 1903 m_opts{opts} 1904 { 1905 // While Erlay support is incomplete, it must be enabled explicitly via -txreconciliation. 1906 // This argument can go away after Erlay support is complete. 1907 if (opts.reconcile_txs) { 1908 m_txreconciliation = std::make_unique<TxReconciliationTracker>(TXRECONCILIATION_VERSION); 1909 } 1910 } 1911 1912 void PeerManagerImpl::StartScheduledTasks(CScheduler& scheduler) 1913 { 1914 // Stale tip checking and peer eviction are on two different timers, but we 1915 // don't want them to get out of sync due to drift in the scheduler, so we 1916 // combine them in one function and schedule at the quicker (peer-eviction) 1917 // timer. 1918 static_assert(EXTRA_PEER_CHECK_INTERVAL < STALE_CHECK_INTERVAL, "peer eviction timer should be less than stale tip check timer"); 1919 scheduler.scheduleEvery([this] { this->CheckForStaleTipAndEvictPeers(); }, std::chrono::seconds{EXTRA_PEER_CHECK_INTERVAL}); 1920 1921 // schedule next run for 10-15 minutes in the future 1922 const auto delta = 10min + FastRandomContext().randrange<std::chrono::milliseconds>(5min); 1923 scheduler.scheduleFromNow([&] { ReattemptInitialBroadcast(scheduler); }, delta); 1924 } 1925 1926 void PeerManagerImpl::ActiveTipChange(const CBlockIndex& new_tip, bool is_ibd) 1927 { 1928 // Ensure mempool mutex was released, otherwise deadlock may occur if another thread holding 1929 // m_tx_download_mutex waits on the mempool mutex. 1930 AssertLockNotHeld(m_mempool.cs); 1931 AssertLockNotHeld(m_tx_download_mutex); 1932 1933 if (!is_ibd) { 1934 LOCK(m_tx_download_mutex); 1935 // If the chain tip has changed, previously rejected transactions might now be valid, e.g. due 1936 // to a timelock. Reset the rejection filters to give those transactions another chance if we 1937 // see them again. 1938 m_txdownloadman.ActiveTipChange(); 1939 } 1940 } 1941 1942 /** 1943 * Evict orphan txn pool entries based on a newly connected 1944 * block, remember the recently confirmed transactions, and delete tracked 1945 * announcements for them. Also save the time of the last tip update and 1946 * possibly reduce dynamic block stalling timeout. 1947 */ 1948 void PeerManagerImpl::BlockConnected( 1949 ChainstateRole role, 1950 const std::shared_ptr<const CBlock>& pblock, 1951 const CBlockIndex* pindex) 1952 { 1953 // Update this for all chainstate roles so that we don't mistakenly see peers 1954 // helping us do background IBD as having a stale tip. 1955 m_last_tip_update = GetTime<std::chrono::seconds>(); 1956 1957 // In case the dynamic timeout was doubled once or more, reduce it slowly back to its default value 1958 auto stalling_timeout = m_block_stalling_timeout.load(); 1959 Assume(stalling_timeout >= BLOCK_STALLING_TIMEOUT_DEFAULT); 1960 if (stalling_timeout != BLOCK_STALLING_TIMEOUT_DEFAULT) { 1961 const auto new_timeout = std::max(std::chrono::duration_cast<std::chrono::seconds>(stalling_timeout * 0.85), BLOCK_STALLING_TIMEOUT_DEFAULT); 1962 if (m_block_stalling_timeout.compare_exchange_strong(stalling_timeout, new_timeout)) { 1963 LogDebug(BCLog::NET, "Decreased stalling timeout to %d seconds\n", count_seconds(new_timeout)); 1964 } 1965 } 1966 1967 // The following task can be skipped since we don't maintain a mempool for 1968 // the ibd/background chainstate. 1969 if (role == ChainstateRole::BACKGROUND) { 1970 return; 1971 } 1972 LOCK(m_tx_download_mutex); 1973 m_txdownloadman.BlockConnected(pblock); 1974 } 1975 1976 void PeerManagerImpl::BlockDisconnected(const std::shared_ptr<const CBlock> &block, const CBlockIndex* pindex) 1977 { 1978 LOCK(m_tx_download_mutex); 1979 m_txdownloadman.BlockDisconnected(); 1980 } 1981 1982 /** 1983 * Maintain state about the best-seen block and fast-announce a compact block 1984 * to compatible peers. 1985 */ 1986 void PeerManagerImpl::NewPoWValidBlock(const CBlockIndex *pindex, const std::shared_ptr<const CBlock>& pblock) 1987 { 1988 auto pcmpctblock = std::make_shared<const CBlockHeaderAndShortTxIDs>(*pblock, FastRandomContext().rand64()); 1989 1990 LOCK(cs_main); 1991 1992 if (pindex->nHeight <= m_highest_fast_announce) 1993 return; 1994 m_highest_fast_announce = pindex->nHeight; 1995 1996 if (!DeploymentActiveAt(*pindex, m_chainman, Consensus::DEPLOYMENT_SEGWIT)) return; 1997 1998 uint256 hashBlock(pblock->GetHash()); 1999 const std::shared_future<CSerializedNetMsg> lazy_ser{ 2000 std::async(std::launch::deferred, [&] { return NetMsg::Make(NetMsgType::CMPCTBLOCK, *pcmpctblock); })}; 2001 2002 { 2003 auto most_recent_block_txs = std::make_unique<std::map<GenTxid, CTransactionRef>>(); 2004 for (const auto& tx : pblock->vtx) { 2005 most_recent_block_txs->emplace(tx->GetHash(), tx); 2006 most_recent_block_txs->emplace(tx->GetWitnessHash(), tx); 2007 } 2008 2009 LOCK(m_most_recent_block_mutex); 2010 m_most_recent_block_hash = hashBlock; 2011 m_most_recent_block = pblock; 2012 m_most_recent_compact_block = pcmpctblock; 2013 m_most_recent_block_txs = std::move(most_recent_block_txs); 2014 } 2015 2016 m_connman.ForEachNode([this, pindex, &lazy_ser, &hashBlock](CNode* pnode) EXCLUSIVE_LOCKS_REQUIRED(::cs_main) { 2017 AssertLockHeld(::cs_main); 2018 2019 if (pnode->GetCommonVersion() < INVALID_CB_NO_BAN_VERSION || pnode->fDisconnect) 2020 return; 2021 ProcessBlockAvailability(pnode->GetId()); 2022 CNodeState &state = *State(pnode->GetId()); 2023 // If the peer has, or we announced to them the previous block already, 2024 // but we don't think they have this one, go ahead and announce it 2025 if (state.m_requested_hb_cmpctblocks && !PeerHasHeader(&state, pindex) && PeerHasHeader(&state, pindex->pprev)) { 2026 2027 LogDebug(BCLog::NET, "%s sending header-and-ids %s to peer=%d\n", "PeerManager::NewPoWValidBlock", 2028 hashBlock.ToString(), pnode->GetId()); 2029 2030 const CSerializedNetMsg& ser_cmpctblock{lazy_ser.get()}; 2031 PushMessage(*pnode, ser_cmpctblock.Copy()); 2032 state.pindexBestHeaderSent = pindex; 2033 } 2034 }); 2035 } 2036 2037 /** 2038 * Update our best height and announce any block hashes which weren't previously 2039 * in m_chainman.ActiveChain() to our peers. 2040 */ 2041 void PeerManagerImpl::UpdatedBlockTip(const CBlockIndex *pindexNew, const CBlockIndex *pindexFork, bool fInitialDownload) 2042 { 2043 SetBestBlock(pindexNew->nHeight, std::chrono::seconds{pindexNew->GetBlockTime()}); 2044 2045 // Don't relay inventory during initial block download. 2046 if (fInitialDownload) return; 2047 2048 // Find the hashes of all blocks that weren't previously in the best chain. 2049 std::vector<uint256> vHashes; 2050 const CBlockIndex *pindexToAnnounce = pindexNew; 2051 while (pindexToAnnounce != pindexFork) { 2052 vHashes.push_back(pindexToAnnounce->GetBlockHash()); 2053 pindexToAnnounce = pindexToAnnounce->pprev; 2054 if (vHashes.size() == MAX_BLOCKS_TO_ANNOUNCE) { 2055 // Limit announcements in case of a huge reorganization. 2056 // Rely on the peer's synchronization mechanism in that case. 2057 break; 2058 } 2059 } 2060 2061 { 2062 LOCK(m_peer_mutex); 2063 for (auto& it : m_peer_map) { 2064 Peer& peer = *it.second; 2065 LOCK(peer.m_block_inv_mutex); 2066 for (const uint256& hash : vHashes | std::views::reverse) { 2067 peer.m_blocks_for_headers_relay.push_back(hash); 2068 } 2069 } 2070 } 2071 2072 m_connman.WakeMessageHandler(); 2073 } 2074 2075 /** 2076 * Handle invalid block rejection and consequent peer discouragement, maintain which 2077 * peers announce compact blocks. 2078 */ 2079 void PeerManagerImpl::BlockChecked(const std::shared_ptr<const CBlock>& block, const BlockValidationState& state) 2080 { 2081 LOCK(cs_main); 2082 2083 const uint256 hash(block->GetHash()); 2084 std::map<uint256, std::pair<NodeId, bool>>::iterator it = mapBlockSource.find(hash); 2085 2086 // If the block failed validation, we know where it came from and we're still connected 2087 // to that peer, maybe punish. 2088 if (state.IsInvalid() && 2089 it != mapBlockSource.end() && 2090 State(it->second.first)) { 2091 MaybePunishNodeForBlock(/*nodeid=*/ it->second.first, state, /*via_compact_block=*/ !it->second.second); 2092 } 2093 // Check that: 2094 // 1. The block is valid 2095 // 2. We're not in initial block download 2096 // 3. This is currently the best block we're aware of. We haven't updated 2097 // the tip yet so we have no way to check this directly here. Instead we 2098 // just check that there are currently no other blocks in flight. 2099 else if (state.IsValid() && 2100 !m_chainman.IsInitialBlockDownload() && 2101 mapBlocksInFlight.count(hash) == mapBlocksInFlight.size()) { 2102 if (it != mapBlockSource.end()) { 2103 MaybeSetPeerAsAnnouncingHeaderAndIDs(it->second.first); 2104 } 2105 } 2106 if (it != mapBlockSource.end()) 2107 mapBlockSource.erase(it); 2108 } 2109 2110 ////////////////////////////////////////////////////////////////////////////// 2111 // 2112 // Messages 2113 // 2114 2115 bool PeerManagerImpl::AlreadyHaveBlock(const uint256& block_hash) 2116 { 2117 return m_chainman.m_blockman.LookupBlockIndex(block_hash) != nullptr; 2118 } 2119 2120 void PeerManagerImpl::SendPings() 2121 { 2122 LOCK(m_peer_mutex); 2123 for(auto& it : m_peer_map) it.second->m_ping_queued = true; 2124 } 2125 2126 void PeerManagerImpl::RelayTransaction(const Txid& txid, const Wtxid& wtxid) 2127 { 2128 LOCK(m_peer_mutex); 2129 for(auto& it : m_peer_map) { 2130 Peer& peer = *it.second; 2131 auto tx_relay = peer.GetTxRelay(); 2132 if (!tx_relay) continue; 2133 2134 LOCK(tx_relay->m_tx_inventory_mutex); 2135 // Only queue transactions for announcement once the version handshake 2136 // is completed. The time of arrival for these transactions is 2137 // otherwise at risk of leaking to a spy, if the spy is able to 2138 // distinguish transactions received during the handshake from the rest 2139 // in the announcement. 2140 if (tx_relay->m_next_inv_send_time == 0s) continue; 2141 2142 const uint256& hash{peer.m_wtxid_relay ? wtxid.ToUint256() : txid.ToUint256()}; 2143 if (!tx_relay->m_tx_inventory_known_filter.contains(hash)) { 2144 tx_relay->m_tx_inventory_to_send.insert(wtxid); 2145 } 2146 } 2147 } 2148 2149 void PeerManagerImpl::RelayAddress(NodeId originator, 2150 const CAddress& addr, 2151 bool fReachable) 2152 { 2153 // We choose the same nodes within a given 24h window (if the list of connected 2154 // nodes does not change) and we don't relay to nodes that already know an 2155 // address. So within 24h we will likely relay a given address once. This is to 2156 // prevent a peer from unjustly giving their address better propagation by sending 2157 // it to us repeatedly. 2158 2159 if (!fReachable && !addr.IsRelayable()) return; 2160 2161 // Relay to a limited number of other nodes 2162 // Use deterministic randomness to send to the same nodes for 24 hours 2163 // at a time so the m_addr_knowns of the chosen nodes prevent repeats 2164 const uint64_t hash_addr{CServiceHash(0, 0)(addr)}; 2165 const auto current_time{GetTime<std::chrono::seconds>()}; 2166 // Adding address hash makes exact rotation time different per address, while preserving periodicity. 2167 const uint64_t time_addr{(static_cast<uint64_t>(count_seconds(current_time)) + hash_addr) / count_seconds(ROTATE_ADDR_RELAY_DEST_INTERVAL)}; 2168 const CSipHasher hasher{m_connman.GetDeterministicRandomizer(RANDOMIZER_ID_ADDRESS_RELAY) 2169 .Write(hash_addr) 2170 .Write(time_addr)}; 2171 2172 // Relay reachable addresses to 2 peers. Unreachable addresses are relayed randomly to 1 or 2 peers. 2173 unsigned int nRelayNodes = (fReachable || (hasher.Finalize() & 1)) ? 2 : 1; 2174 2175 std::array<std::pair<uint64_t, Peer*>, 2> best{{{0, nullptr}, {0, nullptr}}}; 2176 assert(nRelayNodes <= best.size()); 2177 2178 LOCK(m_peer_mutex); 2179 2180 for (auto& [id, peer] : m_peer_map) { 2181 if (peer->m_addr_relay_enabled && id != originator && IsAddrCompatible(*peer, addr)) { 2182 uint64_t hashKey = CSipHasher(hasher).Write(id).Finalize(); 2183 for (unsigned int i = 0; i < nRelayNodes; i++) { 2184 if (hashKey > best[i].first) { 2185 std::copy(best.begin() + i, best.begin() + nRelayNodes - 1, best.begin() + i + 1); 2186 best[i] = std::make_pair(hashKey, peer.get()); 2187 break; 2188 } 2189 } 2190 } 2191 }; 2192 2193 for (unsigned int i = 0; i < nRelayNodes && best[i].first != 0; i++) { 2194 PushAddress(*best[i].second, addr); 2195 } 2196 } 2197 2198 void PeerManagerImpl::ProcessGetBlockData(CNode& pfrom, Peer& peer, const CInv& inv) 2199 { 2200 std::shared_ptr<const CBlock> a_recent_block; 2201 std::shared_ptr<const CBlockHeaderAndShortTxIDs> a_recent_compact_block; 2202 { 2203 LOCK(m_most_recent_block_mutex); 2204 a_recent_block = m_most_recent_block; 2205 a_recent_compact_block = m_most_recent_compact_block; 2206 } 2207 2208 bool need_activate_chain = false; 2209 { 2210 LOCK(cs_main); 2211 const CBlockIndex* pindex = m_chainman.m_blockman.LookupBlockIndex(inv.hash); 2212 if (pindex) { 2213 if (pindex->HaveNumChainTxs() && !pindex->IsValid(BLOCK_VALID_SCRIPTS) && 2214 pindex->IsValid(BLOCK_VALID_TREE)) { 2215 // If we have the block and all of its parents, but have not yet validated it, 2216 // we might be in the middle of connecting it (ie in the unlock of cs_main 2217 // before ActivateBestChain but after AcceptBlock). 2218 // In this case, we need to run ActivateBestChain prior to checking the relay 2219 // conditions below. 2220 need_activate_chain = true; 2221 } 2222 } 2223 } // release cs_main before calling ActivateBestChain 2224 if (need_activate_chain) { 2225 BlockValidationState state; 2226 if (!m_chainman.ActiveChainstate().ActivateBestChain(state, a_recent_block)) { 2227 LogDebug(BCLog::NET, "failed to activate chain (%s)\n", state.ToString()); 2228 } 2229 } 2230 2231 const CBlockIndex* pindex{nullptr}; 2232 const CBlockIndex* tip{nullptr}; 2233 bool can_direct_fetch{false}; 2234 FlatFilePos block_pos{}; 2235 { 2236 LOCK(cs_main); 2237 pindex = m_chainman.m_blockman.LookupBlockIndex(inv.hash); 2238 if (!pindex) { 2239 return; 2240 } 2241 if (!BlockRequestAllowed(pindex)) { 2242 LogDebug(BCLog::NET, "%s: ignoring request from peer=%i for old block that isn't in the main chain\n", __func__, pfrom.GetId()); 2243 return; 2244 } 2245 // disconnect node in case we have reached the outbound limit for serving historical blocks 2246 if (m_connman.OutboundTargetReached(true) && 2247 (((m_chainman.m_best_header != nullptr) && (m_chainman.m_best_header->GetBlockTime() - pindex->GetBlockTime() > HISTORICAL_BLOCK_AGE)) || inv.IsMsgFilteredBlk()) && 2248 !pfrom.HasPermission(NetPermissionFlags::Download) // nodes with the download permission may exceed target 2249 ) { 2250 LogDebug(BCLog::NET, "historical block serving limit reached, %s\n", pfrom.DisconnectMsg(fLogIPs)); 2251 pfrom.fDisconnect = true; 2252 return; 2253 } 2254 tip = m_chainman.ActiveChain().Tip(); 2255 // Avoid leaking prune-height by never sending blocks below the NODE_NETWORK_LIMITED threshold 2256 if (!pfrom.HasPermission(NetPermissionFlags::NoBan) && ( 2257 (((peer.m_our_services & NODE_NETWORK_LIMITED) == NODE_NETWORK_LIMITED) && ((peer.m_our_services & NODE_NETWORK) != NODE_NETWORK) && (tip->nHeight - pindex->nHeight > (int)NODE_NETWORK_LIMITED_MIN_BLOCKS + 2 /* add two blocks buffer extension for possible races */) ) 2258 )) { 2259 LogDebug(BCLog::NET, "Ignore block request below NODE_NETWORK_LIMITED threshold, %s\n", pfrom.DisconnectMsg(fLogIPs)); 2260 //disconnect node and prevent it from stalling (would otherwise wait for the missing block) 2261 pfrom.fDisconnect = true; 2262 return; 2263 } 2264 // Pruned nodes may have deleted the block, so check whether 2265 // it's available before trying to send. 2266 if (!(pindex->nStatus & BLOCK_HAVE_DATA)) { 2267 return; 2268 } 2269 can_direct_fetch = CanDirectFetch(); 2270 block_pos = pindex->GetBlockPos(); 2271 } 2272 2273 std::shared_ptr<const CBlock> pblock; 2274 if (a_recent_block && a_recent_block->GetHash() == inv.hash) { 2275 pblock = a_recent_block; 2276 } else if (inv.IsMsgWitnessBlk()) { 2277 // Fast-path: in this case it is possible to serve the block directly from disk, 2278 // as the network format matches the format on disk 2279 std::vector<std::byte> block_data; 2280 if (!m_chainman.m_blockman.ReadRawBlock(block_data, block_pos)) { 2281 if (WITH_LOCK(m_chainman.GetMutex(), return m_chainman.m_blockman.IsBlockPruned(*pindex))) { 2282 LogDebug(BCLog::NET, "Block was pruned before it could be read, %s\n", pfrom.DisconnectMsg(fLogIPs)); 2283 } else { 2284 LogError("Cannot load block from disk, %s\n", pfrom.DisconnectMsg(fLogIPs)); 2285 } 2286 pfrom.fDisconnect = true; 2287 return; 2288 } 2289 MakeAndPushMessage(pfrom, NetMsgType::BLOCK, std::span{block_data}); 2290 // Don't set pblock as we've sent the block 2291 } else { 2292 // Send block from disk 2293 std::shared_ptr<CBlock> pblockRead = std::make_shared<CBlock>(); 2294 if (!m_chainman.m_blockman.ReadBlock(*pblockRead, block_pos, inv.hash)) { 2295 if (WITH_LOCK(m_chainman.GetMutex(), return m_chainman.m_blockman.IsBlockPruned(*pindex))) { 2296 LogDebug(BCLog::NET, "Block was pruned before it could be read, %s\n", pfrom.DisconnectMsg(fLogIPs)); 2297 } else { 2298 LogError("Cannot load block from disk, %s\n", pfrom.DisconnectMsg(fLogIPs)); 2299 } 2300 pfrom.fDisconnect = true; 2301 return; 2302 } 2303 pblock = pblockRead; 2304 } 2305 if (pblock) { 2306 if (inv.IsMsgBlk()) { 2307 MakeAndPushMessage(pfrom, NetMsgType::BLOCK, TX_NO_WITNESS(*pblock)); 2308 } else if (inv.IsMsgWitnessBlk()) { 2309 MakeAndPushMessage(pfrom, NetMsgType::BLOCK, TX_WITH_WITNESS(*pblock)); 2310 } else if (inv.IsMsgFilteredBlk()) { 2311 bool sendMerkleBlock = false; 2312 CMerkleBlock merkleBlock; 2313 if (auto tx_relay = peer.GetTxRelay(); tx_relay != nullptr) { 2314 LOCK(tx_relay->m_bloom_filter_mutex); 2315 if (tx_relay->m_bloom_filter) { 2316 sendMerkleBlock = true; 2317 merkleBlock = CMerkleBlock(*pblock, *tx_relay->m_bloom_filter); 2318 } 2319 } 2320 if (sendMerkleBlock) { 2321 MakeAndPushMessage(pfrom, NetMsgType::MERKLEBLOCK, merkleBlock); 2322 // CMerkleBlock just contains hashes, so also push any transactions in the block the client did not see 2323 // This avoids hurting performance by pointlessly requiring a round-trip 2324 // Note that there is currently no way for a node to request any single transactions we didn't send here - 2325 // they must either disconnect and retry or request the full block. 2326 // Thus, the protocol spec specified allows for us to provide duplicate txn here, 2327 // however we MUST always provide at least what the remote peer needs 2328 for (const auto& [tx_idx, _] : merkleBlock.vMatchedTxn) 2329 MakeAndPushMessage(pfrom, NetMsgType::TX, TX_NO_WITNESS(*pblock->vtx[tx_idx])); 2330 } 2331 // else 2332 // no response 2333 } else if (inv.IsMsgCmpctBlk()) { 2334 // If a peer is asking for old blocks, we're almost guaranteed 2335 // they won't have a useful mempool to match against a compact block, 2336 // and we don't feel like constructing the object for them, so 2337 // instead we respond with the full, non-compact block. 2338 if (can_direct_fetch && pindex->nHeight >= tip->nHeight - MAX_CMPCTBLOCK_DEPTH) { 2339 if (a_recent_compact_block && a_recent_compact_block->header.GetHash() == inv.hash) { 2340 MakeAndPushMessage(pfrom, NetMsgType::CMPCTBLOCK, *a_recent_compact_block); 2341 } else { 2342 CBlockHeaderAndShortTxIDs cmpctblock{*pblock, m_rng.rand64()}; 2343 MakeAndPushMessage(pfrom, NetMsgType::CMPCTBLOCK, cmpctblock); 2344 } 2345 } else { 2346 MakeAndPushMessage(pfrom, NetMsgType::BLOCK, TX_WITH_WITNESS(*pblock)); 2347 } 2348 } 2349 } 2350 2351 { 2352 LOCK(peer.m_block_inv_mutex); 2353 // Trigger the peer node to send a getblocks request for the next batch of inventory 2354 if (inv.hash == peer.m_continuation_block) { 2355 // Send immediately. This must send even if redundant, 2356 // and we want it right after the last block so they don't 2357 // wait for other stuff first. 2358 std::vector<CInv> vInv; 2359 vInv.emplace_back(MSG_BLOCK, tip->GetBlockHash()); 2360 MakeAndPushMessage(pfrom, NetMsgType::INV, vInv); 2361 peer.m_continuation_block.SetNull(); 2362 } 2363 } 2364 } 2365 2366 CTransactionRef PeerManagerImpl::FindTxForGetData(const Peer::TxRelay& tx_relay, const GenTxid& gtxid) 2367 { 2368 // If a tx was in the mempool prior to the last INV for this peer, permit the request. 2369 auto txinfo{std::visit( 2370 [&](const auto& id) { 2371 return m_mempool.info_for_relay(id, WITH_LOCK(tx_relay.m_tx_inventory_mutex, return tx_relay.m_last_inv_sequence)); 2372 }, 2373 gtxid)}; 2374 if (txinfo.tx) { 2375 return std::move(txinfo.tx); 2376 } 2377 2378 // Or it might be from the most recent block 2379 { 2380 LOCK(m_most_recent_block_mutex); 2381 if (m_most_recent_block_txs != nullptr) { 2382 auto it = m_most_recent_block_txs->find(gtxid); 2383 if (it != m_most_recent_block_txs->end()) return it->second; 2384 } 2385 } 2386 2387 return {}; 2388 } 2389 2390 void PeerManagerImpl::ProcessGetData(CNode& pfrom, Peer& peer, const std::atomic<bool>& interruptMsgProc) 2391 { 2392 AssertLockNotHeld(cs_main); 2393 2394 auto tx_relay = peer.GetTxRelay(); 2395 2396 std::deque<CInv>::iterator it = peer.m_getdata_requests.begin(); 2397 std::vector<CInv> vNotFound; 2398 2399 // Process as many TX items from the front of the getdata queue as 2400 // possible, since they're common and it's efficient to batch process 2401 // them. 2402 while (it != peer.m_getdata_requests.end() && it->IsGenTxMsg()) { 2403 if (interruptMsgProc) return; 2404 // The send buffer provides backpressure. If there's no space in 2405 // the buffer, pause processing until the next call. 2406 if (pfrom.fPauseSend) break; 2407 2408 const CInv &inv = *it++; 2409 2410 if (tx_relay == nullptr) { 2411 // Ignore GETDATA requests for transactions from block-relay-only 2412 // peers and peers that asked us not to announce transactions. 2413 continue; 2414 } 2415 2416 if (auto tx{FindTxForGetData(*tx_relay, ToGenTxid(inv))}) { 2417 // WTX and WITNESS_TX imply we serialize with witness 2418 const auto maybe_with_witness = (inv.IsMsgTx() ? TX_NO_WITNESS : TX_WITH_WITNESS); 2419 MakeAndPushMessage(pfrom, NetMsgType::TX, maybe_with_witness(*tx)); 2420 m_mempool.RemoveUnbroadcastTx(tx->GetHash()); 2421 } else { 2422 vNotFound.push_back(inv); 2423 } 2424 } 2425 2426 // Only process one BLOCK item per call, since they're uncommon and can be 2427 // expensive to process. 2428 if (it != peer.m_getdata_requests.end() && !pfrom.fPauseSend) { 2429 const CInv &inv = *it++; 2430 if (inv.IsGenBlkMsg()) { 2431 ProcessGetBlockData(pfrom, peer, inv); 2432 } 2433 // else: If the first item on the queue is an unknown type, we erase it 2434 // and continue processing the queue on the next call. 2435 // NOTE: previously we wouldn't do so and the peer sending us a malformed GETDATA could 2436 // result in never making progress and this thread using 100% allocated CPU. See 2437 // https://bitcoincore.org/en/2024/07/03/disclose-getdata-cpu. 2438 } 2439 2440 peer.m_getdata_requests.erase(peer.m_getdata_requests.begin(), it); 2441 2442 if (!vNotFound.empty()) { 2443 // Let the peer know that we didn't find what it asked for, so it doesn't 2444 // have to wait around forever. 2445 // SPV clients care about this message: it's needed when they are 2446 // recursively walking the dependencies of relevant unconfirmed 2447 // transactions. SPV clients want to do that because they want to know 2448 // about (and store and rebroadcast and risk analyze) the dependencies 2449 // of transactions relevant to them, without having to download the 2450 // entire memory pool. 2451 // Also, other nodes can use these messages to automatically request a 2452 // transaction from some other peer that announced it, and stop 2453 // waiting for us to respond. 2454 // In normal operation, we often send NOTFOUND messages for parents of 2455 // transactions that we relay; if a peer is missing a parent, they may 2456 // assume we have them and request the parents from us. 2457 MakeAndPushMessage(pfrom, NetMsgType::NOTFOUND, vNotFound); 2458 } 2459 } 2460 2461 uint32_t PeerManagerImpl::GetFetchFlags(const Peer& peer) const 2462 { 2463 uint32_t nFetchFlags = 0; 2464 if (CanServeWitnesses(peer)) { 2465 nFetchFlags |= MSG_WITNESS_FLAG; 2466 } 2467 return nFetchFlags; 2468 } 2469 2470 void PeerManagerImpl::SendBlockTransactions(CNode& pfrom, Peer& peer, const CBlock& block, const BlockTransactionsRequest& req) 2471 { 2472 BlockTransactions resp(req); 2473 unsigned int tx_requested_size = 0; 2474 for (size_t i = 0; i < req.indexes.size(); i++) { 2475 if (req.indexes[i] >= block.vtx.size()) { 2476 Misbehaving(peer, "getblocktxn with out-of-bounds tx indices"); 2477 return; 2478 } 2479 resp.txn[i] = block.vtx[req.indexes[i]]; 2480 tx_requested_size += resp.txn[i]->GetTotalSize(); 2481 } 2482 2483 LogDebug(BCLog::CMPCTBLOCK, "Peer %d sent us a GETBLOCKTXN for block %s, sending a BLOCKTXN with %u txns. (%u bytes)\n", pfrom.GetId(), block.GetHash().ToString(), resp.txn.size(), tx_requested_size); 2484 MakeAndPushMessage(pfrom, NetMsgType::BLOCKTXN, resp); 2485 } 2486 2487 bool PeerManagerImpl::CheckHeadersPoW(const std::vector<CBlockHeader>& headers, const Consensus::Params& consensusParams, Peer& peer) 2488 { 2489 // Do these headers have proof-of-work matching what's claimed? 2490 if (!HasValidProofOfWork(headers, consensusParams)) { 2491 Misbehaving(peer, "header with invalid proof of work"); 2492 return false; 2493 } 2494 2495 // Are these headers connected to each other? 2496 if (!CheckHeadersAreContinuous(headers)) { 2497 Misbehaving(peer, "non-continuous headers sequence"); 2498 return false; 2499 } 2500 return true; 2501 } 2502 2503 arith_uint256 PeerManagerImpl::GetAntiDoSWorkThreshold() 2504 { 2505 arith_uint256 near_chaintip_work = 0; 2506 LOCK(cs_main); 2507 if (m_chainman.ActiveChain().Tip() != nullptr) { 2508 const CBlockIndex *tip = m_chainman.ActiveChain().Tip(); 2509 // Use a 144 block buffer, so that we'll accept headers that fork from 2510 // near our tip. 2511 near_chaintip_work = tip->nChainWork - std::min<arith_uint256>(144*GetBlockProof(*tip), tip->nChainWork); 2512 } 2513 return std::max(near_chaintip_work, m_chainman.MinimumChainWork()); 2514 } 2515 2516 /** 2517 * Special handling for unconnecting headers that might be part of a block 2518 * announcement. 2519 * 2520 * We'll send a getheaders message in response to try to connect the chain. 2521 */ 2522 void PeerManagerImpl::HandleUnconnectingHeaders(CNode& pfrom, Peer& peer, 2523 const std::vector<CBlockHeader>& headers) 2524 { 2525 // Try to fill in the missing headers. 2526 const CBlockIndex* best_header{WITH_LOCK(cs_main, return m_chainman.m_best_header)}; 2527 if (MaybeSendGetHeaders(pfrom, GetLocator(best_header), peer)) { 2528 LogDebug(BCLog::NET, "received header %s: missing prev block %s, sending getheaders (%d) to end (peer=%d)\n", 2529 headers[0].GetHash().ToString(), 2530 headers[0].hashPrevBlock.ToString(), 2531 best_header->nHeight, 2532 pfrom.GetId()); 2533 } 2534 2535 // Set hashLastUnknownBlock for this peer, so that if we 2536 // eventually get the headers - even from a different peer - 2537 // we can use this peer to download. 2538 WITH_LOCK(cs_main, UpdateBlockAvailability(pfrom.GetId(), headers.back().GetHash())); 2539 } 2540 2541 bool PeerManagerImpl::CheckHeadersAreContinuous(const std::vector<CBlockHeader>& headers) const 2542 { 2543 uint256 hashLastBlock; 2544 for (const CBlockHeader& header : headers) { 2545 if (!hashLastBlock.IsNull() && header.hashPrevBlock != hashLastBlock) { 2546 return false; 2547 } 2548 hashLastBlock = header.GetHash(); 2549 } 2550 return true; 2551 } 2552 2553 bool PeerManagerImpl::IsContinuationOfLowWorkHeadersSync(Peer& peer, CNode& pfrom, std::vector<CBlockHeader>& headers) 2554 { 2555 if (peer.m_headers_sync) { 2556 auto result = peer.m_headers_sync->ProcessNextHeaders(headers, headers.size() == m_opts.max_headers_result); 2557 // If it is a valid continuation, we should treat the existing getheaders request as responded to. 2558 if (result.success) peer.m_last_getheaders_timestamp = {}; 2559 if (result.request_more) { 2560 auto locator = peer.m_headers_sync->NextHeadersRequestLocator(); 2561 // If we were instructed to ask for a locator, it should not be empty. 2562 Assume(!locator.vHave.empty()); 2563 // We can only be instructed to request more if processing was successful. 2564 Assume(result.success); 2565 if (!locator.vHave.empty()) { 2566 // It should be impossible for the getheaders request to fail, 2567 // because we just cleared the last getheaders timestamp. 2568 bool sent_getheaders = MaybeSendGetHeaders(pfrom, locator, peer); 2569 Assume(sent_getheaders); 2570 LogDebug(BCLog::NET, "more getheaders (from %s) to peer=%d\n", 2571 locator.vHave.front().ToString(), pfrom.GetId()); 2572 } 2573 } 2574 2575 if (peer.m_headers_sync->GetState() == HeadersSyncState::State::FINAL) { 2576 peer.m_headers_sync.reset(nullptr); 2577 2578 // Delete this peer's entry in m_headers_presync_stats. 2579 // If this is m_headers_presync_bestpeer, it will be replaced later 2580 // by the next peer that triggers the else{} branch below. 2581 LOCK(m_headers_presync_mutex); 2582 m_headers_presync_stats.erase(pfrom.GetId()); 2583 } else { 2584 // Build statistics for this peer's sync. 2585 HeadersPresyncStats stats; 2586 stats.first = peer.m_headers_sync->GetPresyncWork(); 2587 if (peer.m_headers_sync->GetState() == HeadersSyncState::State::PRESYNC) { 2588 stats.second = {peer.m_headers_sync->GetPresyncHeight(), 2589 peer.m_headers_sync->GetPresyncTime()}; 2590 } 2591 2592 // Update statistics in stats. 2593 LOCK(m_headers_presync_mutex); 2594 m_headers_presync_stats[pfrom.GetId()] = stats; 2595 auto best_it = m_headers_presync_stats.find(m_headers_presync_bestpeer); 2596 bool best_updated = false; 2597 if (best_it == m_headers_presync_stats.end()) { 2598 // If the cached best peer is outdated, iterate over all remaining ones (including 2599 // newly updated one) to find the best one. 2600 NodeId peer_best{-1}; 2601 const HeadersPresyncStats* stat_best{nullptr}; 2602 for (const auto& [peer, stat] : m_headers_presync_stats) { 2603 if (!stat_best || stat > *stat_best) { 2604 peer_best = peer; 2605 stat_best = &stat; 2606 } 2607 } 2608 m_headers_presync_bestpeer = peer_best; 2609 best_updated = (peer_best == pfrom.GetId()); 2610 } else if (best_it->first == pfrom.GetId() || stats > best_it->second) { 2611 // pfrom was and remains the best peer, or pfrom just became best. 2612 m_headers_presync_bestpeer = pfrom.GetId(); 2613 best_updated = true; 2614 } 2615 if (best_updated && stats.second.has_value()) { 2616 // If the best peer updated, and it is in its first phase, signal. 2617 m_headers_presync_should_signal = true; 2618 } 2619 } 2620 2621 if (result.success) { 2622 // We only overwrite the headers passed in if processing was 2623 // successful. 2624 headers.swap(result.pow_validated_headers); 2625 } 2626 2627 return result.success; 2628 } 2629 // Either we didn't have a sync in progress, or something went wrong 2630 // processing these headers, or we are returning headers to the caller to 2631 // process. 2632 return false; 2633 } 2634 2635 bool PeerManagerImpl::TryLowWorkHeadersSync(Peer& peer, CNode& pfrom, const CBlockIndex* chain_start_header, std::vector<CBlockHeader>& headers) 2636 { 2637 // Calculate the claimed total work on this chain. 2638 arith_uint256 total_work = chain_start_header->nChainWork + CalculateClaimedHeadersWork(headers); 2639 2640 // Our dynamic anti-DoS threshold (minimum work required on a headers chain 2641 // before we'll store it) 2642 arith_uint256 minimum_chain_work = GetAntiDoSWorkThreshold(); 2643 2644 // Avoid DoS via low-difficulty-headers by only processing if the headers 2645 // are part of a chain with sufficient work. 2646 if (total_work < minimum_chain_work) { 2647 // Only try to sync with this peer if their headers message was full; 2648 // otherwise they don't have more headers after this so no point in 2649 // trying to sync their too-little-work chain. 2650 if (headers.size() == m_opts.max_headers_result) { 2651 // Note: we could advance to the last header in this set that is 2652 // known to us, rather than starting at the first header (which we 2653 // may already have); however this is unlikely to matter much since 2654 // ProcessHeadersMessage() already handles the case where all 2655 // headers in a received message are already known and are 2656 // ancestors of m_best_header or chainActive.Tip(), by skipping 2657 // this logic in that case. So even if the first header in this set 2658 // of headers is known, some header in this set must be new, so 2659 // advancing to the first unknown header would be a small effect. 2660 LOCK(peer.m_headers_sync_mutex); 2661 peer.m_headers_sync.reset(new HeadersSyncState(peer.m_id, m_chainparams.GetConsensus(), 2662 m_chainparams.HeadersSync(), chain_start_header, minimum_chain_work)); 2663 2664 // Now a HeadersSyncState object for tracking this synchronization 2665 // is created, process the headers using it as normal. Failures are 2666 // handled inside of IsContinuationOfLowWorkHeadersSync. 2667 (void)IsContinuationOfLowWorkHeadersSync(peer, pfrom, headers); 2668 } else { 2669 LogDebug(BCLog::NET, "Ignoring low-work chain (height=%u) from peer=%d\n", chain_start_header->nHeight + headers.size(), pfrom.GetId()); 2670 } 2671 2672 // The peer has not yet given us a chain that meets our work threshold, 2673 // so we want to prevent further processing of the headers in any case. 2674 headers = {}; 2675 return true; 2676 } 2677 2678 return false; 2679 } 2680 2681 bool PeerManagerImpl::IsAncestorOfBestHeaderOrTip(const CBlockIndex* header) 2682 { 2683 if (header == nullptr) { 2684 return false; 2685 } else if (m_chainman.m_best_header != nullptr && header == m_chainman.m_best_header->GetAncestor(header->nHeight)) { 2686 return true; 2687 } else if (m_chainman.ActiveChain().Contains(header)) { 2688 return true; 2689 } 2690 return false; 2691 } 2692 2693 bool PeerManagerImpl::MaybeSendGetHeaders(CNode& pfrom, const CBlockLocator& locator, Peer& peer) 2694 { 2695 const auto current_time = NodeClock::now(); 2696 2697 // Only allow a new getheaders message to go out if we don't have a recent 2698 // one already in-flight 2699 if (current_time - peer.m_last_getheaders_timestamp > HEADERS_RESPONSE_TIME) { 2700 MakeAndPushMessage(pfrom, NetMsgType::GETHEADERS, locator, uint256()); 2701 peer.m_last_getheaders_timestamp = current_time; 2702 return true; 2703 } 2704 return false; 2705 } 2706 2707 /* 2708 * Given a new headers tip ending in last_header, potentially request blocks towards that tip. 2709 * We require that the given tip have at least as much work as our tip, and for 2710 * our current tip to be "close to synced" (see CanDirectFetch()). 2711 */ 2712 void PeerManagerImpl::HeadersDirectFetchBlocks(CNode& pfrom, const Peer& peer, const CBlockIndex& last_header) 2713 { 2714 LOCK(cs_main); 2715 CNodeState *nodestate = State(pfrom.GetId()); 2716 2717 if (CanDirectFetch() && last_header.IsValid(BLOCK_VALID_TREE) && m_chainman.ActiveChain().Tip()->nChainWork <= last_header.nChainWork) { 2718 std::vector<const CBlockIndex*> vToFetch; 2719 const CBlockIndex* pindexWalk{&last_header}; 2720 // Calculate all the blocks we'd need to switch to last_header, up to a limit. 2721 while (pindexWalk && !m_chainman.ActiveChain().Contains(pindexWalk) && vToFetch.size() <= MAX_BLOCKS_IN_TRANSIT_PER_PEER) { 2722 if (!(pindexWalk->nStatus & BLOCK_HAVE_DATA) && 2723 !IsBlockRequested(pindexWalk->GetBlockHash()) && 2724 (!DeploymentActiveAt(*pindexWalk, m_chainman, Consensus::DEPLOYMENT_SEGWIT) || CanServeWitnesses(peer))) { 2725 // We don't have this block, and it's not yet in flight. 2726 vToFetch.push_back(pindexWalk); 2727 } 2728 pindexWalk = pindexWalk->pprev; 2729 } 2730 // If pindexWalk still isn't on our main chain, we're looking at a 2731 // very large reorg at a time we think we're close to caught up to 2732 // the main chain -- this shouldn't really happen. Bail out on the 2733 // direct fetch and rely on parallel download instead. 2734 if (!m_chainman.ActiveChain().Contains(pindexWalk)) { 2735 LogDebug(BCLog::NET, "Large reorg, won't direct fetch to %s (%d)\n", 2736 last_header.GetBlockHash().ToString(), 2737 last_header.nHeight); 2738 } else { 2739 std::vector<CInv> vGetData; 2740 // Download as much as possible, from earliest to latest. 2741 for (const CBlockIndex* pindex : vToFetch | std::views::reverse) { 2742 if (nodestate->vBlocksInFlight.size() >= MAX_BLOCKS_IN_TRANSIT_PER_PEER) { 2743 // Can't download any more from this peer 2744 break; 2745 } 2746 uint32_t nFetchFlags = GetFetchFlags(peer); 2747 vGetData.emplace_back(MSG_BLOCK | nFetchFlags, pindex->GetBlockHash()); 2748 BlockRequested(pfrom.GetId(), *pindex); 2749 LogDebug(BCLog::NET, "Requesting block %s from peer=%d\n", 2750 pindex->GetBlockHash().ToString(), pfrom.GetId()); 2751 } 2752 if (vGetData.size() > 1) { 2753 LogDebug(BCLog::NET, "Downloading blocks toward %s (%d) via headers direct fetch\n", 2754 last_header.GetBlockHash().ToString(), 2755 last_header.nHeight); 2756 } 2757 if (vGetData.size() > 0) { 2758 if (!m_opts.ignore_incoming_txs && 2759 nodestate->m_provides_cmpctblocks && 2760 vGetData.size() == 1 && 2761 mapBlocksInFlight.size() == 1 && 2762 last_header.pprev->IsValid(BLOCK_VALID_CHAIN)) { 2763 // In any case, we want to download using a compact block, not a regular one 2764 vGetData[0] = CInv(MSG_CMPCT_BLOCK, vGetData[0].hash); 2765 } 2766 MakeAndPushMessage(pfrom, NetMsgType::GETDATA, vGetData); 2767 } 2768 } 2769 } 2770 } 2771 2772 /** 2773 * Given receipt of headers from a peer ending in last_header, along with 2774 * whether that header was new and whether the headers message was full, 2775 * update the state we keep for the peer. 2776 */ 2777 void PeerManagerImpl::UpdatePeerStateForReceivedHeaders(CNode& pfrom, Peer& peer, 2778 const CBlockIndex& last_header, bool received_new_header, bool may_have_more_headers) 2779 { 2780 LOCK(cs_main); 2781 CNodeState *nodestate = State(pfrom.GetId()); 2782 2783 UpdateBlockAvailability(pfrom.GetId(), last_header.GetBlockHash()); 2784 2785 // From here, pindexBestKnownBlock should be guaranteed to be non-null, 2786 // because it is set in UpdateBlockAvailability. Some nullptr checks 2787 // are still present, however, as belt-and-suspenders. 2788 2789 if (received_new_header && last_header.nChainWork > m_chainman.ActiveChain().Tip()->nChainWork) { 2790 nodestate->m_last_block_announcement = GetTime(); 2791 } 2792 2793 // If we're in IBD, we want outbound peers that will serve us a useful 2794 // chain. Disconnect peers that are on chains with insufficient work. 2795 if (m_chainman.IsInitialBlockDownload() && !may_have_more_headers) { 2796 // If the peer has no more headers to give us, then we know we have 2797 // their tip. 2798 if (nodestate->pindexBestKnownBlock && nodestate->pindexBestKnownBlock->nChainWork < m_chainman.MinimumChainWork()) { 2799 // This peer has too little work on their headers chain to help 2800 // us sync -- disconnect if it is an outbound disconnection 2801 // candidate. 2802 // Note: We compare their tip to the minimum chain work (rather than 2803 // m_chainman.ActiveChain().Tip()) because we won't start block download 2804 // until we have a headers chain that has at least 2805 // the minimum chain work, even if a peer has a chain past our tip, 2806 // as an anti-DoS measure. 2807 if (pfrom.IsOutboundOrBlockRelayConn()) { 2808 LogInfo("outbound peer headers chain has insufficient work, %s\n", pfrom.DisconnectMsg(fLogIPs)); 2809 pfrom.fDisconnect = true; 2810 } 2811 } 2812 } 2813 2814 // If this is an outbound full-relay peer, check to see if we should protect 2815 // it from the bad/lagging chain logic. 2816 // Note that outbound block-relay peers are excluded from this protection, and 2817 // thus always subject to eviction under the bad/lagging chain logic. 2818 // See ChainSyncTimeoutState. 2819 if (!pfrom.fDisconnect && pfrom.IsFullOutboundConn() && nodestate->pindexBestKnownBlock != nullptr) { 2820 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) { 2821 LogDebug(BCLog::NET, "Protecting outbound peer=%d from eviction\n", pfrom.GetId()); 2822 nodestate->m_chain_sync.m_protect = true; 2823 ++m_outbound_peers_with_protect_from_disconnect; 2824 } 2825 } 2826 } 2827 2828 void PeerManagerImpl::ProcessHeadersMessage(CNode& pfrom, Peer& peer, 2829 std::vector<CBlockHeader>&& headers, 2830 bool via_compact_block) 2831 { 2832 size_t nCount = headers.size(); 2833 2834 if (nCount == 0) { 2835 // Nothing interesting. Stop asking this peers for more headers. 2836 // If we were in the middle of headers sync, receiving an empty headers 2837 // message suggests that the peer suddenly has nothing to give us 2838 // (perhaps it reorged to our chain). Clear download state for this peer. 2839 LOCK(peer.m_headers_sync_mutex); 2840 if (peer.m_headers_sync) { 2841 peer.m_headers_sync.reset(nullptr); 2842 LOCK(m_headers_presync_mutex); 2843 m_headers_presync_stats.erase(pfrom.GetId()); 2844 } 2845 // A headers message with no headers cannot be an announcement, so assume 2846 // it is a response to our last getheaders request, if there is one. 2847 peer.m_last_getheaders_timestamp = {}; 2848 return; 2849 } 2850 2851 // Before we do any processing, make sure these pass basic sanity checks. 2852 // We'll rely on headers having valid proof-of-work further down, as an 2853 // anti-DoS criteria (note: this check is required before passing any 2854 // headers into HeadersSyncState). 2855 if (!CheckHeadersPoW(headers, m_chainparams.GetConsensus(), peer)) { 2856 // Misbehaving() calls are handled within CheckHeadersPoW(), so we can 2857 // just return. (Note that even if a header is announced via compact 2858 // block, the header itself should be valid, so this type of error can 2859 // always be punished.) 2860 return; 2861 } 2862 2863 const CBlockIndex *pindexLast = nullptr; 2864 2865 // We'll set already_validated_work to true if these headers are 2866 // successfully processed as part of a low-work headers sync in progress 2867 // (either in PRESYNC or REDOWNLOAD phase). 2868 // If true, this will mean that any headers returned to us (ie during 2869 // REDOWNLOAD) can be validated without further anti-DoS checks. 2870 bool already_validated_work = false; 2871 2872 // If we're in the middle of headers sync, let it do its magic. 2873 bool have_headers_sync = false; 2874 { 2875 LOCK(peer.m_headers_sync_mutex); 2876 2877 already_validated_work = IsContinuationOfLowWorkHeadersSync(peer, pfrom, headers); 2878 2879 // The headers we passed in may have been: 2880 // - untouched, perhaps if no headers-sync was in progress, or some 2881 // failure occurred 2882 // - erased, such as if the headers were successfully processed and no 2883 // additional headers processing needs to take place (such as if we 2884 // are still in PRESYNC) 2885 // - replaced with headers that are now ready for validation, such as 2886 // during the REDOWNLOAD phase of a low-work headers sync. 2887 // So just check whether we still have headers that we need to process, 2888 // or not. 2889 if (headers.empty()) { 2890 return; 2891 } 2892 2893 have_headers_sync = !!peer.m_headers_sync; 2894 } 2895 2896 // Do these headers connect to something in our block index? 2897 const CBlockIndex *chain_start_header{WITH_LOCK(::cs_main, return m_chainman.m_blockman.LookupBlockIndex(headers[0].hashPrevBlock))}; 2898 bool headers_connect_blockindex{chain_start_header != nullptr}; 2899 2900 if (!headers_connect_blockindex) { 2901 // This could be a BIP 130 block announcement, use 2902 // special logic for handling headers that don't connect, as this 2903 // could be benign. 2904 HandleUnconnectingHeaders(pfrom, peer, headers); 2905 return; 2906 } 2907 2908 // If headers connect, assume that this is in response to any outstanding getheaders 2909 // request we may have sent, and clear out the time of our last request. Non-connecting 2910 // headers cannot be a response to a getheaders request. 2911 peer.m_last_getheaders_timestamp = {}; 2912 2913 // If the headers we received are already in memory and an ancestor of 2914 // m_best_header or our tip, skip anti-DoS checks. These headers will not 2915 // use any more memory (and we are not leaking information that could be 2916 // used to fingerprint us). 2917 const CBlockIndex *last_received_header{nullptr}; 2918 { 2919 LOCK(cs_main); 2920 last_received_header = m_chainman.m_blockman.LookupBlockIndex(headers.back().GetHash()); 2921 if (IsAncestorOfBestHeaderOrTip(last_received_header)) { 2922 already_validated_work = true; 2923 } 2924 } 2925 2926 // If our peer has NetPermissionFlags::NoBan privileges, then bypass our 2927 // anti-DoS logic (this saves bandwidth when we connect to a trusted peer 2928 // on startup). 2929 if (pfrom.HasPermission(NetPermissionFlags::NoBan)) { 2930 already_validated_work = true; 2931 } 2932 2933 // At this point, the headers connect to something in our block index. 2934 // Do anti-DoS checks to determine if we should process or store for later 2935 // processing. 2936 if (!already_validated_work && TryLowWorkHeadersSync(peer, pfrom, 2937 chain_start_header, headers)) { 2938 // If we successfully started a low-work headers sync, then there 2939 // should be no headers to process any further. 2940 Assume(headers.empty()); 2941 return; 2942 } 2943 2944 // At this point, we have a set of headers with sufficient work on them 2945 // which can be processed. 2946 2947 // If we don't have the last header, then this peer will have given us 2948 // something new (if these headers are valid). 2949 bool received_new_header{last_received_header == nullptr}; 2950 2951 // Now process all the headers. 2952 BlockValidationState state; 2953 const bool processed{m_chainman.ProcessNewBlockHeaders(headers, 2954 /*min_pow_checked=*/true, 2955 state, &pindexLast)}; 2956 if (!processed) { 2957 if (state.IsInvalid()) { 2958 MaybePunishNodeForBlock(pfrom.GetId(), state, via_compact_block, "invalid header received"); 2959 return; 2960 } 2961 } 2962 assert(pindexLast); 2963 2964 if (processed && received_new_header) { 2965 LogBlockHeader(*pindexLast, pfrom, /*via_compact_block=*/false); 2966 } 2967 2968 // Consider fetching more headers if we are not using our headers-sync mechanism. 2969 if (nCount == m_opts.max_headers_result && !have_headers_sync) { 2970 // Headers message had its maximum size; the peer may have more headers. 2971 if (MaybeSendGetHeaders(pfrom, GetLocator(pindexLast), peer)) { 2972 LogDebug(BCLog::NET, "more getheaders (%d) to end to peer=%d (startheight:%d)\n", 2973 pindexLast->nHeight, pfrom.GetId(), peer.m_starting_height); 2974 } 2975 } 2976 2977 UpdatePeerStateForReceivedHeaders(pfrom, peer, *pindexLast, received_new_header, nCount == m_opts.max_headers_result); 2978 2979 // Consider immediately downloading blocks. 2980 HeadersDirectFetchBlocks(pfrom, peer, *pindexLast); 2981 2982 return; 2983 } 2984 2985 std::optional<node::PackageToValidate> PeerManagerImpl::ProcessInvalidTx(NodeId nodeid, const CTransactionRef& ptx, const TxValidationState& state, 2986 bool first_time_failure) 2987 { 2988 AssertLockNotHeld(m_peer_mutex); 2989 AssertLockHeld(g_msgproc_mutex); 2990 AssertLockHeld(m_tx_download_mutex); 2991 2992 PeerRef peer{GetPeerRef(nodeid)}; 2993 2994 LogDebug(BCLog::MEMPOOLREJ, "%s (wtxid=%s) from peer=%d was not accepted: %s\n", 2995 ptx->GetHash().ToString(), 2996 ptx->GetWitnessHash().ToString(), 2997 nodeid, 2998 state.ToString()); 2999 3000 const auto& [add_extra_compact_tx, unique_parents, package_to_validate] = m_txdownloadman.MempoolRejectedTx(ptx, state, nodeid, first_time_failure); 3001 3002 if (add_extra_compact_tx && RecursiveDynamicUsage(*ptx) < 100000) { 3003 AddToCompactExtraTransactions(ptx); 3004 } 3005 for (const Txid& parent_txid : unique_parents) { 3006 if (peer) AddKnownTx(*peer, parent_txid.ToUint256()); 3007 } 3008 3009 return package_to_validate; 3010 } 3011 3012 void PeerManagerImpl::ProcessValidTx(NodeId nodeid, const CTransactionRef& tx, const std::list<CTransactionRef>& replaced_transactions) 3013 { 3014 AssertLockNotHeld(m_peer_mutex); 3015 AssertLockHeld(g_msgproc_mutex); 3016 AssertLockHeld(m_tx_download_mutex); 3017 3018 m_txdownloadman.MempoolAcceptedTx(tx); 3019 3020 LogDebug(BCLog::MEMPOOL, "AcceptToMemoryPool: peer=%d: accepted %s (wtxid=%s) (poolsz %u txn, %u kB)\n", 3021 nodeid, 3022 tx->GetHash().ToString(), 3023 tx->GetWitnessHash().ToString(), 3024 m_mempool.size(), m_mempool.DynamicMemoryUsage() / 1000); 3025 3026 RelayTransaction(tx->GetHash(), tx->GetWitnessHash()); 3027 3028 for (const CTransactionRef& removedTx : replaced_transactions) { 3029 AddToCompactExtraTransactions(removedTx); 3030 } 3031 } 3032 3033 void PeerManagerImpl::ProcessPackageResult(const node::PackageToValidate& package_to_validate, const PackageMempoolAcceptResult& package_result) 3034 { 3035 AssertLockNotHeld(m_peer_mutex); 3036 AssertLockHeld(g_msgproc_mutex); 3037 AssertLockHeld(m_tx_download_mutex); 3038 3039 const auto& package = package_to_validate.m_txns; 3040 const auto& senders = package_to_validate.m_senders; 3041 3042 if (package_result.m_state.IsInvalid()) { 3043 m_txdownloadman.MempoolRejectedPackage(package); 3044 } 3045 // We currently only expect to process 1-parent-1-child packages. Remove if this changes. 3046 if (!Assume(package.size() == 2)) return; 3047 3048 // Iterate backwards to erase in-package descendants from the orphanage before they become 3049 // relevant in AddChildrenToWorkSet. 3050 auto package_iter = package.rbegin(); 3051 auto senders_iter = senders.rbegin(); 3052 while (package_iter != package.rend()) { 3053 const auto& tx = *package_iter; 3054 const NodeId nodeid = *senders_iter; 3055 const auto it_result{package_result.m_tx_results.find(tx->GetWitnessHash())}; 3056 3057 // It is not guaranteed that a result exists for every transaction. 3058 if (it_result != package_result.m_tx_results.end()) { 3059 const auto& tx_result = it_result->second; 3060 switch (tx_result.m_result_type) { 3061 case MempoolAcceptResult::ResultType::VALID: 3062 { 3063 ProcessValidTx(nodeid, tx, tx_result.m_replaced_transactions); 3064 break; 3065 } 3066 case MempoolAcceptResult::ResultType::INVALID: 3067 case MempoolAcceptResult::ResultType::DIFFERENT_WITNESS: 3068 { 3069 // Don't add to vExtraTxnForCompact, as these transactions should have already been 3070 // added there when added to the orphanage or rejected for TX_RECONSIDERABLE. 3071 // This should be updated if package submission is ever used for transactions 3072 // that haven't already been validated before. 3073 ProcessInvalidTx(nodeid, tx, tx_result.m_state, /*first_time_failure=*/false); 3074 break; 3075 } 3076 case MempoolAcceptResult::ResultType::MEMPOOL_ENTRY: 3077 { 3078 // AlreadyHaveTx() should be catching transactions that are already in mempool. 3079 Assume(false); 3080 break; 3081 } 3082 } 3083 } 3084 package_iter++; 3085 senders_iter++; 3086 } 3087 } 3088 3089 // NOTE: the orphan processing used to be uninterruptible and quadratic, which could allow a peer to stall the node for 3090 // hours with specially crafted transactions. See https://bitcoincore.org/en/2024/07/03/disclose-orphan-dos. 3091 bool PeerManagerImpl::ProcessOrphanTx(Peer& peer) 3092 { 3093 AssertLockHeld(g_msgproc_mutex); 3094 LOCK2(::cs_main, m_tx_download_mutex); 3095 3096 CTransactionRef porphanTx = nullptr; 3097 3098 while (CTransactionRef porphanTx = m_txdownloadman.GetTxToReconsider(peer.m_id)) { 3099 const MempoolAcceptResult result = m_chainman.ProcessTransaction(porphanTx); 3100 const TxValidationState& state = result.m_state; 3101 const Txid& orphanHash = porphanTx->GetHash(); 3102 const Wtxid& orphan_wtxid = porphanTx->GetWitnessHash(); 3103 3104 if (result.m_result_type == MempoolAcceptResult::ResultType::VALID) { 3105 LogDebug(BCLog::TXPACKAGES, " accepted orphan tx %s (wtxid=%s)\n", orphanHash.ToString(), orphan_wtxid.ToString()); 3106 ProcessValidTx(peer.m_id, porphanTx, result.m_replaced_transactions); 3107 return true; 3108 } else if (state.GetResult() != TxValidationResult::TX_MISSING_INPUTS) { 3109 LogDebug(BCLog::TXPACKAGES, " invalid orphan tx %s (wtxid=%s) from peer=%d. %s\n", 3110 orphanHash.ToString(), 3111 orphan_wtxid.ToString(), 3112 peer.m_id, 3113 state.ToString()); 3114 3115 if (Assume(state.IsInvalid() && 3116 state.GetResult() != TxValidationResult::TX_UNKNOWN && 3117 state.GetResult() != TxValidationResult::TX_NO_MEMPOOL && 3118 state.GetResult() != TxValidationResult::TX_RESULT_UNSET)) { 3119 ProcessInvalidTx(peer.m_id, porphanTx, state, /*first_time_failure=*/false); 3120 } 3121 return true; 3122 } 3123 } 3124 3125 return false; 3126 } 3127 3128 bool PeerManagerImpl::PrepareBlockFilterRequest(CNode& node, Peer& peer, 3129 BlockFilterType filter_type, uint32_t start_height, 3130 const uint256& stop_hash, uint32_t max_height_diff, 3131 const CBlockIndex*& stop_index, 3132 BlockFilterIndex*& filter_index) 3133 { 3134 const bool supported_filter_type = 3135 (filter_type == BlockFilterType::BASIC && 3136 (peer.m_our_services & NODE_COMPACT_FILTERS)); 3137 if (!supported_filter_type) { 3138 LogDebug(BCLog::NET, "peer requested unsupported block filter type: %d, %s\n", 3139 static_cast<uint8_t>(filter_type), node.DisconnectMsg(fLogIPs)); 3140 node.fDisconnect = true; 3141 return false; 3142 } 3143 3144 { 3145 LOCK(cs_main); 3146 stop_index = m_chainman.m_blockman.LookupBlockIndex(stop_hash); 3147 3148 // Check that the stop block exists and the peer would be allowed to fetch it. 3149 if (!stop_index || !BlockRequestAllowed(stop_index)) { 3150 LogDebug(BCLog::NET, "peer requested invalid block hash: %s, %s\n", 3151 stop_hash.ToString(), node.DisconnectMsg(fLogIPs)); 3152 node.fDisconnect = true; 3153 return false; 3154 } 3155 } 3156 3157 uint32_t stop_height = stop_index->nHeight; 3158 if (start_height > stop_height) { 3159 LogDebug(BCLog::NET, "peer sent invalid getcfilters/getcfheaders with " 3160 "start height %d and stop height %d, %s\n", 3161 start_height, stop_height, node.DisconnectMsg(fLogIPs)); 3162 node.fDisconnect = true; 3163 return false; 3164 } 3165 if (stop_height - start_height >= max_height_diff) { 3166 LogDebug(BCLog::NET, "peer requested too many cfilters/cfheaders: %d / %d, %s\n", 3167 stop_height - start_height + 1, max_height_diff, node.DisconnectMsg(fLogIPs)); 3168 node.fDisconnect = true; 3169 return false; 3170 } 3171 3172 filter_index = GetBlockFilterIndex(filter_type); 3173 if (!filter_index) { 3174 LogDebug(BCLog::NET, "Filter index for supported type %s not found\n", BlockFilterTypeName(filter_type)); 3175 return false; 3176 } 3177 3178 return true; 3179 } 3180 3181 void PeerManagerImpl::ProcessGetCFilters(CNode& node, Peer& peer, DataStream& vRecv) 3182 { 3183 uint8_t filter_type_ser; 3184 uint32_t start_height; 3185 uint256 stop_hash; 3186 3187 vRecv >> filter_type_ser >> start_height >> stop_hash; 3188 3189 const BlockFilterType filter_type = static_cast<BlockFilterType>(filter_type_ser); 3190 3191 const CBlockIndex* stop_index; 3192 BlockFilterIndex* filter_index; 3193 if (!PrepareBlockFilterRequest(node, peer, filter_type, start_height, stop_hash, 3194 MAX_GETCFILTERS_SIZE, stop_index, filter_index)) { 3195 return; 3196 } 3197 3198 std::vector<BlockFilter> filters; 3199 if (!filter_index->LookupFilterRange(start_height, stop_index, filters)) { 3200 LogDebug(BCLog::NET, "Failed to find block filter in index: filter_type=%s, start_height=%d, stop_hash=%s\n", 3201 BlockFilterTypeName(filter_type), start_height, stop_hash.ToString()); 3202 return; 3203 } 3204 3205 for (const auto& filter : filters) { 3206 MakeAndPushMessage(node, NetMsgType::CFILTER, filter); 3207 } 3208 } 3209 3210 void PeerManagerImpl::ProcessGetCFHeaders(CNode& node, Peer& peer, DataStream& vRecv) 3211 { 3212 uint8_t filter_type_ser; 3213 uint32_t start_height; 3214 uint256 stop_hash; 3215 3216 vRecv >> filter_type_ser >> start_height >> stop_hash; 3217 3218 const BlockFilterType filter_type = static_cast<BlockFilterType>(filter_type_ser); 3219 3220 const CBlockIndex* stop_index; 3221 BlockFilterIndex* filter_index; 3222 if (!PrepareBlockFilterRequest(node, peer, filter_type, start_height, stop_hash, 3223 MAX_GETCFHEADERS_SIZE, stop_index, filter_index)) { 3224 return; 3225 } 3226 3227 uint256 prev_header; 3228 if (start_height > 0) { 3229 const CBlockIndex* const prev_block = 3230 stop_index->GetAncestor(static_cast<int>(start_height - 1)); 3231 if (!filter_index->LookupFilterHeader(prev_block, prev_header)) { 3232 LogDebug(BCLog::NET, "Failed to find block filter header in index: filter_type=%s, block_hash=%s\n", 3233 BlockFilterTypeName(filter_type), prev_block->GetBlockHash().ToString()); 3234 return; 3235 } 3236 } 3237 3238 std::vector<uint256> filter_hashes; 3239 if (!filter_index->LookupFilterHashRange(start_height, stop_index, filter_hashes)) { 3240 LogDebug(BCLog::NET, "Failed to find block filter hashes in index: filter_type=%s, start_height=%d, stop_hash=%s\n", 3241 BlockFilterTypeName(filter_type), start_height, stop_hash.ToString()); 3242 return; 3243 } 3244 3245 MakeAndPushMessage(node, NetMsgType::CFHEADERS, 3246 filter_type_ser, 3247 stop_index->GetBlockHash(), 3248 prev_header, 3249 filter_hashes); 3250 } 3251 3252 void PeerManagerImpl::ProcessGetCFCheckPt(CNode& node, Peer& peer, DataStream& vRecv) 3253 { 3254 uint8_t filter_type_ser; 3255 uint256 stop_hash; 3256 3257 vRecv >> filter_type_ser >> stop_hash; 3258 3259 const BlockFilterType filter_type = static_cast<BlockFilterType>(filter_type_ser); 3260 3261 const CBlockIndex* stop_index; 3262 BlockFilterIndex* filter_index; 3263 if (!PrepareBlockFilterRequest(node, peer, filter_type, /*start_height=*/0, stop_hash, 3264 /*max_height_diff=*/std::numeric_limits<uint32_t>::max(), 3265 stop_index, filter_index)) { 3266 return; 3267 } 3268 3269 std::vector<uint256> headers(stop_index->nHeight / CFCHECKPT_INTERVAL); 3270 3271 // Populate headers. 3272 const CBlockIndex* block_index = stop_index; 3273 for (int i = headers.size() - 1; i >= 0; i--) { 3274 int height = (i + 1) * CFCHECKPT_INTERVAL; 3275 block_index = block_index->GetAncestor(height); 3276 3277 if (!filter_index->LookupFilterHeader(block_index, headers[i])) { 3278 LogDebug(BCLog::NET, "Failed to find block filter header in index: filter_type=%s, block_hash=%s\n", 3279 BlockFilterTypeName(filter_type), block_index->GetBlockHash().ToString()); 3280 return; 3281 } 3282 } 3283 3284 MakeAndPushMessage(node, NetMsgType::CFCHECKPT, 3285 filter_type_ser, 3286 stop_index->GetBlockHash(), 3287 headers); 3288 } 3289 3290 void PeerManagerImpl::ProcessBlock(CNode& node, const std::shared_ptr<const CBlock>& block, bool force_processing, bool min_pow_checked) 3291 { 3292 bool new_block{false}; 3293 m_chainman.ProcessNewBlock(block, force_processing, min_pow_checked, &new_block); 3294 if (new_block) { 3295 node.m_last_block_time = GetTime<std::chrono::seconds>(); 3296 // In case this block came from a different peer than we requested 3297 // from, we can erase the block request now anyway (as we just stored 3298 // this block to disk). 3299 LOCK(cs_main); 3300 RemoveBlockRequest(block->GetHash(), std::nullopt); 3301 } else { 3302 LOCK(cs_main); 3303 mapBlockSource.erase(block->GetHash()); 3304 } 3305 } 3306 3307 void PeerManagerImpl::ProcessCompactBlockTxns(CNode& pfrom, Peer& peer, const BlockTransactions& block_transactions) 3308 { 3309 std::shared_ptr<CBlock> pblock = std::make_shared<CBlock>(); 3310 bool fBlockRead{false}; 3311 { 3312 LOCK(cs_main); 3313 3314 auto range_flight = mapBlocksInFlight.equal_range(block_transactions.blockhash); 3315 size_t already_in_flight = std::distance(range_flight.first, range_flight.second); 3316 bool requested_block_from_this_peer{false}; 3317 3318 // Multimap ensures ordering of outstanding requests. It's either empty or first in line. 3319 bool first_in_flight = already_in_flight == 0 || (range_flight.first->second.first == pfrom.GetId()); 3320 3321 while (range_flight.first != range_flight.second) { 3322 auto [node_id, block_it] = range_flight.first->second; 3323 if (node_id == pfrom.GetId() && block_it->partialBlock) { 3324 requested_block_from_this_peer = true; 3325 break; 3326 } 3327 range_flight.first++; 3328 } 3329 3330 if (!requested_block_from_this_peer) { 3331 LogDebug(BCLog::NET, "Peer %d sent us block transactions for block we weren't expecting\n", pfrom.GetId()); 3332 return; 3333 } 3334 3335 PartiallyDownloadedBlock& partialBlock = *range_flight.first->second.second->partialBlock; 3336 3337 if (partialBlock.header.IsNull()) { 3338 // It is possible for the header to be empty if a previous call to FillBlock wiped the header, but left 3339 // the PartiallyDownloadedBlock pointer around (i.e. did not call RemoveBlockRequest). In this case, we 3340 // should not call LookupBlockIndex below. 3341 RemoveBlockRequest(block_transactions.blockhash, pfrom.GetId()); 3342 Misbehaving(peer, "previous compact block reconstruction attempt failed"); 3343 LogDebug(BCLog::NET, "Peer %d sent compact block transactions multiple times", pfrom.GetId()); 3344 return; 3345 } 3346 3347 // We should not have gotten this far in compact block processing unless it's attached to a known header 3348 const CBlockIndex* prev_block{Assume(m_chainman.m_blockman.LookupBlockIndex(partialBlock.header.hashPrevBlock))}; 3349 ReadStatus status = partialBlock.FillBlock(*pblock, block_transactions.txn, 3350 /*segwit_active=*/DeploymentActiveAfter(prev_block, m_chainman, Consensus::DEPLOYMENT_SEGWIT)); 3351 if (status == READ_STATUS_INVALID) { 3352 RemoveBlockRequest(block_transactions.blockhash, pfrom.GetId()); // Reset in-flight state in case Misbehaving does not result in a disconnect 3353 Misbehaving(peer, "invalid compact block/non-matching block transactions"); 3354 return; 3355 } else if (status == READ_STATUS_FAILED) { 3356 if (first_in_flight) { 3357 // Might have collided, fall back to getdata now :( 3358 // We keep the failed partialBlock to disallow processing another compact block announcement from the same 3359 // peer for the same block. We let the full block download below continue under the same m_downloading_since 3360 // timer. 3361 std::vector<CInv> invs; 3362 invs.emplace_back(MSG_BLOCK | GetFetchFlags(peer), block_transactions.blockhash); 3363 MakeAndPushMessage(pfrom, NetMsgType::GETDATA, invs); 3364 } else { 3365 RemoveBlockRequest(block_transactions.blockhash, pfrom.GetId()); 3366 LogDebug(BCLog::NET, "Peer %d sent us a compact block but it failed to reconstruct, waiting on first download to complete\n", pfrom.GetId()); 3367 return; 3368 } 3369 } else { 3370 // Block is okay for further processing 3371 RemoveBlockRequest(block_transactions.blockhash, pfrom.GetId()); // it is now an empty pointer 3372 fBlockRead = true; 3373 // mapBlockSource is used for potentially punishing peers and 3374 // updating which peers send us compact blocks, so the race 3375 // between here and cs_main in ProcessNewBlock is fine. 3376 // BIP 152 permits peers to relay compact blocks after validating 3377 // the header only; we should not punish peers if the block turns 3378 // out to be invalid. 3379 mapBlockSource.emplace(block_transactions.blockhash, std::make_pair(pfrom.GetId(), false)); 3380 } 3381 } // Don't hold cs_main when we call into ProcessNewBlock 3382 if (fBlockRead) { 3383 // Since we requested this block (it was in mapBlocksInFlight), force it to be processed, 3384 // even if it would not be a candidate for new tip (missing previous block, chain not long enough, etc) 3385 // This bypasses some anti-DoS logic in AcceptBlock (eg to prevent 3386 // disk-space attacks), but this should be safe due to the 3387 // protections in the compact block handler -- see related comment 3388 // in compact block optimistic reconstruction handling. 3389 ProcessBlock(pfrom, pblock, /*force_processing=*/true, /*min_pow_checked=*/true); 3390 } 3391 return; 3392 } 3393 3394 void PeerManagerImpl::LogBlockHeader(const CBlockIndex& index, const CNode& peer, bool via_compact_block) { 3395 // To prevent log spam, this function should only be called after it was determined that a 3396 // header is both new and valid. 3397 // 3398 // These messages are valuable for detecting potential selfish mining behavior; 3399 // if multiple displacing headers are seen near simultaneously across many 3400 // nodes in the network, this might be an indication of selfish mining. 3401 // In addition it can be used to identify peers which send us a header, but 3402 // don't followup with a complete and valid (compact) block. 3403 // Having this log by default when not in IBD ensures broad availability of 3404 // this data in case investigation is merited. 3405 const auto msg = strprintf( 3406 "Saw new %sheader hash=%s height=%d peer=%d%s", 3407 via_compact_block ? "cmpctblock " : "", 3408 index.GetBlockHash().ToString(), 3409 index.nHeight, 3410 peer.GetId(), 3411 peer.LogIP(fLogIPs) 3412 ); 3413 if (m_chainman.IsInitialBlockDownload()) { 3414 LogDebug(BCLog::VALIDATION, "%s", msg); 3415 } else { 3416 LogInfo("%s", msg); 3417 } 3418 } 3419 3420 void PeerManagerImpl::ProcessMessage(CNode& pfrom, const std::string& msg_type, DataStream& vRecv, 3421 const std::chrono::microseconds time_received, 3422 const std::atomic<bool>& interruptMsgProc) 3423 { 3424 AssertLockHeld(g_msgproc_mutex); 3425 3426 LogDebug(BCLog::NET, "received: %s (%u bytes) peer=%d\n", SanitizeString(msg_type), vRecv.size(), pfrom.GetId()); 3427 3428 PeerRef peer = GetPeerRef(pfrom.GetId()); 3429 if (peer == nullptr) return; 3430 3431 if (msg_type == NetMsgType::VERSION) { 3432 if (pfrom.nVersion != 0) { 3433 LogDebug(BCLog::NET, "redundant version message from peer=%d\n", pfrom.GetId()); 3434 return; 3435 } 3436 3437 int64_t nTime; 3438 CService addrMe; 3439 uint64_t nNonce = 1; 3440 ServiceFlags nServices; 3441 int nVersion; 3442 std::string cleanSubVer; 3443 int starting_height = -1; 3444 bool fRelay = true; 3445 3446 vRecv >> nVersion >> Using<CustomUintFormatter<8>>(nServices) >> nTime; 3447 if (nTime < 0) { 3448 nTime = 0; 3449 } 3450 vRecv.ignore(8); // Ignore the addrMe service bits sent by the peer 3451 vRecv >> CNetAddr::V1(addrMe); 3452 if (!pfrom.IsInboundConn()) 3453 { 3454 // Overwrites potentially existing services. In contrast to this, 3455 // unvalidated services received via gossip relay in ADDR/ADDRV2 3456 // messages are only ever added but cannot replace existing ones. 3457 m_addrman.SetServices(pfrom.addr, nServices); 3458 } 3459 if (pfrom.ExpectServicesFromConn() && !HasAllDesirableServiceFlags(nServices)) 3460 { 3461 LogDebug(BCLog::NET, "peer does not offer the expected services (%08x offered, %08x expected), %s\n", 3462 nServices, 3463 GetDesirableServiceFlags(nServices), 3464 pfrom.DisconnectMsg(fLogIPs)); 3465 pfrom.fDisconnect = true; 3466 return; 3467 } 3468 3469 if (nVersion < MIN_PEER_PROTO_VERSION) { 3470 // disconnect from peers older than this proto version 3471 LogDebug(BCLog::NET, "peer using obsolete version %i, %s\n", nVersion, pfrom.DisconnectMsg(fLogIPs)); 3472 pfrom.fDisconnect = true; 3473 return; 3474 } 3475 3476 if (!vRecv.empty()) { 3477 // The version message includes information about the sending node which we don't use: 3478 // - 8 bytes (service bits) 3479 // - 16 bytes (ipv6 address) 3480 // - 2 bytes (port) 3481 vRecv.ignore(26); 3482 vRecv >> nNonce; 3483 } 3484 if (!vRecv.empty()) { 3485 std::string strSubVer; 3486 vRecv >> LIMITED_STRING(strSubVer, MAX_SUBVERSION_LENGTH); 3487 cleanSubVer = SanitizeString(strSubVer); 3488 } 3489 if (!vRecv.empty()) { 3490 vRecv >> starting_height; 3491 } 3492 if (!vRecv.empty()) 3493 vRecv >> fRelay; 3494 // Disconnect if we connected to ourself 3495 if (pfrom.IsInboundConn() && !m_connman.CheckIncomingNonce(nNonce)) 3496 { 3497 LogPrintf("connected to self at %s, disconnecting\n", pfrom.addr.ToStringAddrPort()); 3498 pfrom.fDisconnect = true; 3499 return; 3500 } 3501 3502 if (pfrom.IsInboundConn() && addrMe.IsRoutable()) 3503 { 3504 SeenLocal(addrMe); 3505 } 3506 3507 // Inbound peers send us their version message when they connect. 3508 // We send our version message in response. 3509 if (pfrom.IsInboundConn()) { 3510 PushNodeVersion(pfrom, *peer); 3511 } 3512 3513 // Change version 3514 const int greatest_common_version = std::min(nVersion, PROTOCOL_VERSION); 3515 pfrom.SetCommonVersion(greatest_common_version); 3516 pfrom.nVersion = nVersion; 3517 3518 if (greatest_common_version >= WTXID_RELAY_VERSION) { 3519 MakeAndPushMessage(pfrom, NetMsgType::WTXIDRELAY); 3520 } 3521 3522 // Signal ADDRv2 support (BIP155). 3523 if (greatest_common_version >= 70016) { 3524 // BIP155 defines addrv2 and sendaddrv2 for all protocol versions, but some 3525 // implementations reject messages they don't know. As a courtesy, don't send 3526 // it to nodes with a version before 70016, as no software is known to support 3527 // BIP155 that doesn't announce at least that protocol version number. 3528 MakeAndPushMessage(pfrom, NetMsgType::SENDADDRV2); 3529 } 3530 3531 pfrom.m_has_all_wanted_services = HasAllDesirableServiceFlags(nServices); 3532 peer->m_their_services = nServices; 3533 pfrom.SetAddrLocal(addrMe); 3534 { 3535 LOCK(pfrom.m_subver_mutex); 3536 pfrom.cleanSubVer = cleanSubVer; 3537 } 3538 peer->m_starting_height = starting_height; 3539 3540 // Only initialize the Peer::TxRelay m_relay_txs data structure if: 3541 // - this isn't an outbound block-relay-only connection, and 3542 // - this isn't an outbound feeler connection, and 3543 // - fRelay=true (the peer wishes to receive transaction announcements) 3544 // or we're offering NODE_BLOOM to this peer. NODE_BLOOM means that 3545 // the peer may turn on transaction relay later. 3546 if (!pfrom.IsBlockOnlyConn() && 3547 !pfrom.IsFeelerConn() && 3548 (fRelay || (peer->m_our_services & NODE_BLOOM))) { 3549 auto* const tx_relay = peer->SetTxRelay(); 3550 { 3551 LOCK(tx_relay->m_bloom_filter_mutex); 3552 tx_relay->m_relay_txs = fRelay; // set to true after we get the first filter* message 3553 } 3554 if (fRelay) pfrom.m_relays_txs = true; 3555 } 3556 3557 if (greatest_common_version >= WTXID_RELAY_VERSION && m_txreconciliation) { 3558 // Per BIP-330, we announce txreconciliation support if: 3559 // - protocol version per the peer's VERSION message supports WTXID_RELAY; 3560 // - transaction relay is supported per the peer's VERSION message 3561 // - this is not a block-relay-only connection and not a feeler 3562 // - this is not an addr fetch connection; 3563 // - we are not in -blocksonly mode. 3564 const auto* tx_relay = peer->GetTxRelay(); 3565 if (tx_relay && WITH_LOCK(tx_relay->m_bloom_filter_mutex, return tx_relay->m_relay_txs) && 3566 !pfrom.IsAddrFetchConn() && !m_opts.ignore_incoming_txs) { 3567 const uint64_t recon_salt = m_txreconciliation->PreRegisterPeer(pfrom.GetId()); 3568 MakeAndPushMessage(pfrom, NetMsgType::SENDTXRCNCL, 3569 TXRECONCILIATION_VERSION, recon_salt); 3570 } 3571 } 3572 3573 MakeAndPushMessage(pfrom, NetMsgType::VERACK); 3574 3575 // Potentially mark this peer as a preferred download peer. 3576 { 3577 LOCK(cs_main); 3578 CNodeState* state = State(pfrom.GetId()); 3579 state->fPreferredDownload = (!pfrom.IsInboundConn() || pfrom.HasPermission(NetPermissionFlags::NoBan)) && !pfrom.IsAddrFetchConn() && CanServeBlocks(*peer); 3580 m_num_preferred_download_peers += state->fPreferredDownload; 3581 } 3582 3583 // Attempt to initialize address relay for outbound peers and use result 3584 // to decide whether to send GETADDR, so that we don't send it to 3585 // inbound or outbound block-relay-only peers. 3586 bool send_getaddr{false}; 3587 if (!pfrom.IsInboundConn()) { 3588 send_getaddr = SetupAddressRelay(pfrom, *peer); 3589 } 3590 if (send_getaddr) { 3591 // Do a one-time address fetch to help populate/update our addrman. 3592 // If we're starting up for the first time, our addrman may be pretty 3593 // empty, so this mechanism is important to help us connect to the network. 3594 // We skip this for block-relay-only peers. We want to avoid 3595 // potentially leaking addr information and we do not want to 3596 // indicate to the peer that we will participate in addr relay. 3597 MakeAndPushMessage(pfrom, NetMsgType::GETADDR); 3598 peer->m_getaddr_sent = true; 3599 // When requesting a getaddr, accept an additional MAX_ADDR_TO_SEND addresses in response 3600 // (bypassing the MAX_ADDR_PROCESSING_TOKEN_BUCKET limit). 3601 peer->m_addr_token_bucket += MAX_ADDR_TO_SEND; 3602 } 3603 3604 if (!pfrom.IsInboundConn()) { 3605 // For non-inbound connections, we update the addrman to record 3606 // connection success so that addrman will have an up-to-date 3607 // notion of which peers are online and available. 3608 // 3609 // While we strive to not leak information about block-relay-only 3610 // connections via the addrman, not moving an address to the tried 3611 // table is also potentially detrimental because new-table entries 3612 // are subject to eviction in the event of addrman collisions. We 3613 // mitigate the information-leak by never calling 3614 // AddrMan::Connected() on block-relay-only peers; see 3615 // FinalizeNode(). 3616 // 3617 // This moves an address from New to Tried table in Addrman, 3618 // resolves tried-table collisions, etc. 3619 m_addrman.Good(pfrom.addr); 3620 } 3621 3622 const auto mapped_as{m_connman.GetMappedAS(pfrom.addr)}; 3623 LogDebug(BCLog::NET, "receive version message: %s: version %d, blocks=%d, us=%s, txrelay=%d, peer=%d%s%s\n", 3624 cleanSubVer, pfrom.nVersion, 3625 peer->m_starting_height, addrMe.ToStringAddrPort(), fRelay, pfrom.GetId(), 3626 pfrom.LogIP(fLogIPs), (mapped_as ? strprintf(", mapped_as=%d", mapped_as) : "")); 3627 3628 peer->m_time_offset = NodeSeconds{std::chrono::seconds{nTime}} - Now<NodeSeconds>(); 3629 if (!pfrom.IsInboundConn()) { 3630 // Don't use timedata samples from inbound peers to make it 3631 // harder for others to create false warnings about our clock being out of sync. 3632 m_outbound_time_offsets.Add(peer->m_time_offset); 3633 m_outbound_time_offsets.WarnIfOutOfSync(); 3634 } 3635 3636 // If the peer is old enough to have the old alert system, send it the final alert. 3637 if (greatest_common_version <= 70012) { 3638 constexpr auto finalAlert{"60010000000000000000000000ffffff7f00000000ffffff7ffeffff7f01ffffff7f00000000ffffff7f00ffffff7f002f555247454e543a20416c657274206b657920636f6d70726f6d697365642c2075706772616465207265717569726564004630440220653febd6410f470f6bae11cad19c48413becb1ac2c17f908fd0fd53bdc3abd5202206d0e9c96fe88d4a0f01ed9dedae2b6f9e00da94cad0fecaae66ecf689bf71b50"_hex}; 3639 MakeAndPushMessage(pfrom, "alert", finalAlert); 3640 } 3641 3642 // Feeler connections exist only to verify if address is online. 3643 if (pfrom.IsFeelerConn()) { 3644 LogDebug(BCLog::NET, "feeler connection completed, %s\n", pfrom.DisconnectMsg(fLogIPs)); 3645 pfrom.fDisconnect = true; 3646 } 3647 return; 3648 } 3649 3650 if (pfrom.nVersion == 0) { 3651 // Must have a version message before anything else 3652 LogDebug(BCLog::NET, "non-version message before version handshake. Message \"%s\" from peer=%d\n", SanitizeString(msg_type), pfrom.GetId()); 3653 return; 3654 } 3655 3656 if (msg_type == NetMsgType::VERACK) { 3657 if (pfrom.fSuccessfullyConnected) { 3658 LogDebug(BCLog::NET, "ignoring redundant verack message from peer=%d\n", pfrom.GetId()); 3659 return; 3660 } 3661 3662 // Log successful connections unconditionally for outbound, but not for inbound as those 3663 // can be triggered by an attacker at high rate. 3664 if (!pfrom.IsInboundConn() || LogAcceptCategory(BCLog::NET, BCLog::Level::Debug)) { 3665 const auto mapped_as{m_connman.GetMappedAS(pfrom.addr)}; 3666 LogPrintf("New %s %s peer connected: version: %d, blocks=%d, peer=%d%s%s\n", 3667 pfrom.ConnectionTypeAsString(), 3668 TransportTypeAsString(pfrom.m_transport->GetInfo().transport_type), 3669 pfrom.nVersion.load(), peer->m_starting_height, 3670 pfrom.GetId(), pfrom.LogIP(fLogIPs), 3671 (mapped_as ? strprintf(", mapped_as=%d", mapped_as) : "")); 3672 } 3673 3674 if (pfrom.GetCommonVersion() >= SHORT_IDS_BLOCKS_VERSION) { 3675 // Tell our peer we are willing to provide version 2 cmpctblocks. 3676 // However, we do not request new block announcements using 3677 // cmpctblock messages. 3678 // We send this to non-NODE NETWORK peers as well, because 3679 // they may wish to request compact blocks from us 3680 MakeAndPushMessage(pfrom, NetMsgType::SENDCMPCT, /*high_bandwidth=*/false, /*version=*/CMPCTBLOCKS_VERSION); 3681 } 3682 3683 if (m_txreconciliation) { 3684 if (!peer->m_wtxid_relay || !m_txreconciliation->IsPeerRegistered(pfrom.GetId())) { 3685 // We could have optimistically pre-registered/registered the peer. In that case, 3686 // we should forget about the reconciliation state here if this wasn't followed 3687 // by WTXIDRELAY (since WTXIDRELAY can't be announced later). 3688 m_txreconciliation->ForgetPeer(pfrom.GetId()); 3689 } 3690 } 3691 3692 if (auto tx_relay = peer->GetTxRelay()) { 3693 // `TxRelay::m_tx_inventory_to_send` must be empty before the 3694 // version handshake is completed as 3695 // `TxRelay::m_next_inv_send_time` is first initialised in 3696 // `SendMessages` after the verack is received. Any transactions 3697 // received during the version handshake would otherwise 3698 // immediately be advertised without random delay, potentially 3699 // leaking the time of arrival to a spy. 3700 Assume(WITH_LOCK( 3701 tx_relay->m_tx_inventory_mutex, 3702 return tx_relay->m_tx_inventory_to_send.empty() && 3703 tx_relay->m_next_inv_send_time == 0s)); 3704 } 3705 3706 { 3707 LOCK2(::cs_main, m_tx_download_mutex); 3708 const CNodeState* state = State(pfrom.GetId()); 3709 m_txdownloadman.ConnectedPeer(pfrom.GetId(), node::TxDownloadConnectionInfo { 3710 .m_preferred = state->fPreferredDownload, 3711 .m_relay_permissions = pfrom.HasPermission(NetPermissionFlags::Relay), 3712 .m_wtxid_relay = peer->m_wtxid_relay, 3713 }); 3714 } 3715 3716 pfrom.fSuccessfullyConnected = true; 3717 return; 3718 } 3719 3720 if (msg_type == NetMsgType::SENDHEADERS) { 3721 peer->m_prefers_headers = true; 3722 return; 3723 } 3724 3725 if (msg_type == NetMsgType::SENDCMPCT) { 3726 bool sendcmpct_hb{false}; 3727 uint64_t sendcmpct_version{0}; 3728 vRecv >> sendcmpct_hb >> sendcmpct_version; 3729 3730 // Only support compact block relay with witnesses 3731 if (sendcmpct_version != CMPCTBLOCKS_VERSION) return; 3732 3733 LOCK(cs_main); 3734 CNodeState* nodestate = State(pfrom.GetId()); 3735 nodestate->m_provides_cmpctblocks = true; 3736 nodestate->m_requested_hb_cmpctblocks = sendcmpct_hb; 3737 // save whether peer selects us as BIP152 high-bandwidth peer 3738 // (receiving sendcmpct(1) signals high-bandwidth, sendcmpct(0) low-bandwidth) 3739 pfrom.m_bip152_highbandwidth_from = sendcmpct_hb; 3740 return; 3741 } 3742 3743 // BIP339 defines feature negotiation of wtxidrelay, which must happen between 3744 // VERSION and VERACK to avoid relay problems from switching after a connection is up. 3745 if (msg_type == NetMsgType::WTXIDRELAY) { 3746 if (pfrom.fSuccessfullyConnected) { 3747 // Disconnect peers that send a wtxidrelay message after VERACK. 3748 LogDebug(BCLog::NET, "wtxidrelay received after verack, %s\n", pfrom.DisconnectMsg(fLogIPs)); 3749 pfrom.fDisconnect = true; 3750 return; 3751 } 3752 if (pfrom.GetCommonVersion() >= WTXID_RELAY_VERSION) { 3753 if (!peer->m_wtxid_relay) { 3754 peer->m_wtxid_relay = true; 3755 m_wtxid_relay_peers++; 3756 } else { 3757 LogDebug(BCLog::NET, "ignoring duplicate wtxidrelay from peer=%d\n", pfrom.GetId()); 3758 } 3759 } else { 3760 LogDebug(BCLog::NET, "ignoring wtxidrelay due to old common version=%d from peer=%d\n", pfrom.GetCommonVersion(), pfrom.GetId()); 3761 } 3762 return; 3763 } 3764 3765 // BIP155 defines feature negotiation of addrv2 and sendaddrv2, which must happen 3766 // between VERSION and VERACK. 3767 if (msg_type == NetMsgType::SENDADDRV2) { 3768 if (pfrom.fSuccessfullyConnected) { 3769 // Disconnect peers that send a SENDADDRV2 message after VERACK. 3770 LogDebug(BCLog::NET, "sendaddrv2 received after verack, %s\n", pfrom.DisconnectMsg(fLogIPs)); 3771 pfrom.fDisconnect = true; 3772 return; 3773 } 3774 peer->m_wants_addrv2 = true; 3775 return; 3776 } 3777 3778 // Received from a peer demonstrating readiness to announce transactions via reconciliations. 3779 // This feature negotiation must happen between VERSION and VERACK to avoid relay problems 3780 // from switching announcement protocols after the connection is up. 3781 if (msg_type == NetMsgType::SENDTXRCNCL) { 3782 if (!m_txreconciliation) { 3783 LogDebug(BCLog::NET, "sendtxrcncl from peer=%d ignored, as our node does not have txreconciliation enabled\n", pfrom.GetId()); 3784 return; 3785 } 3786 3787 if (pfrom.fSuccessfullyConnected) { 3788 LogDebug(BCLog::NET, "sendtxrcncl received after verack, %s\n", pfrom.DisconnectMsg(fLogIPs)); 3789 pfrom.fDisconnect = true; 3790 return; 3791 } 3792 3793 // Peer must not offer us reconciliations if we specified no tx relay support in VERSION. 3794 if (RejectIncomingTxs(pfrom)) { 3795 LogDebug(BCLog::NET, "sendtxrcncl received to which we indicated no tx relay, %s\n", pfrom.DisconnectMsg(fLogIPs)); 3796 pfrom.fDisconnect = true; 3797 return; 3798 } 3799 3800 // Peer must not offer us reconciliations if they specified no tx relay support in VERSION. 3801 // This flag might also be false in other cases, but the RejectIncomingTxs check above 3802 // eliminates them, so that this flag fully represents what we are looking for. 3803 const auto* tx_relay = peer->GetTxRelay(); 3804 if (!tx_relay || !WITH_LOCK(tx_relay->m_bloom_filter_mutex, return tx_relay->m_relay_txs)) { 3805 LogDebug(BCLog::NET, "sendtxrcncl received which indicated no tx relay to us, %s\n", pfrom.DisconnectMsg(fLogIPs)); 3806 pfrom.fDisconnect = true; 3807 return; 3808 } 3809 3810 uint32_t peer_txreconcl_version; 3811 uint64_t remote_salt; 3812 vRecv >> peer_txreconcl_version >> remote_salt; 3813 3814 const ReconciliationRegisterResult result = m_txreconciliation->RegisterPeer(pfrom.GetId(), pfrom.IsInboundConn(), 3815 peer_txreconcl_version, remote_salt); 3816 switch (result) { 3817 case ReconciliationRegisterResult::NOT_FOUND: 3818 LogDebug(BCLog::NET, "Ignore unexpected txreconciliation signal from peer=%d\n", pfrom.GetId()); 3819 break; 3820 case ReconciliationRegisterResult::SUCCESS: 3821 break; 3822 case ReconciliationRegisterResult::ALREADY_REGISTERED: 3823 LogDebug(BCLog::NET, "txreconciliation protocol violation (sendtxrcncl received from already registered peer), %s\n", pfrom.DisconnectMsg(fLogIPs)); 3824 pfrom.fDisconnect = true; 3825 return; 3826 case ReconciliationRegisterResult::PROTOCOL_VIOLATION: 3827 LogDebug(BCLog::NET, "txreconciliation protocol violation, %s\n", pfrom.DisconnectMsg(fLogIPs)); 3828 pfrom.fDisconnect = true; 3829 return; 3830 } 3831 return; 3832 } 3833 3834 if (!pfrom.fSuccessfullyConnected) { 3835 LogDebug(BCLog::NET, "Unsupported message \"%s\" prior to verack from peer=%d\n", SanitizeString(msg_type), pfrom.GetId()); 3836 return; 3837 } 3838 3839 if (msg_type == NetMsgType::ADDR || msg_type == NetMsgType::ADDRV2) { 3840 const auto ser_params{ 3841 msg_type == NetMsgType::ADDRV2 ? 3842 // Set V2 param so that the CNetAddr and CAddress 3843 // unserialize methods know that an address in v2 format is coming. 3844 CAddress::V2_NETWORK : 3845 CAddress::V1_NETWORK, 3846 }; 3847 3848 std::vector<CAddress> vAddr; 3849 3850 vRecv >> ser_params(vAddr); 3851 3852 if (!SetupAddressRelay(pfrom, *peer)) { 3853 LogDebug(BCLog::NET, "ignoring %s message from %s peer=%d\n", msg_type, pfrom.ConnectionTypeAsString(), pfrom.GetId()); 3854 return; 3855 } 3856 3857 if (vAddr.size() > MAX_ADDR_TO_SEND) 3858 { 3859 Misbehaving(*peer, strprintf("%s message size = %u", msg_type, vAddr.size())); 3860 return; 3861 } 3862 3863 // Store the new addresses 3864 std::vector<CAddress> vAddrOk; 3865 const auto current_a_time{Now<NodeSeconds>()}; 3866 3867 // Update/increment addr rate limiting bucket. 3868 const auto current_time{GetTime<std::chrono::microseconds>()}; 3869 if (peer->m_addr_token_bucket < MAX_ADDR_PROCESSING_TOKEN_BUCKET) { 3870 // Don't increment bucket if it's already full 3871 const auto time_diff = std::max(current_time - peer->m_addr_token_timestamp, 0us); 3872 const double increment = Ticks<SecondsDouble>(time_diff) * MAX_ADDR_RATE_PER_SECOND; 3873 peer->m_addr_token_bucket = std::min<double>(peer->m_addr_token_bucket + increment, MAX_ADDR_PROCESSING_TOKEN_BUCKET); 3874 } 3875 peer->m_addr_token_timestamp = current_time; 3876 3877 const bool rate_limited = !pfrom.HasPermission(NetPermissionFlags::Addr); 3878 uint64_t num_proc = 0; 3879 uint64_t num_rate_limit = 0; 3880 std::shuffle(vAddr.begin(), vAddr.end(), m_rng); 3881 for (CAddress& addr : vAddr) 3882 { 3883 if (interruptMsgProc) 3884 return; 3885 3886 // Apply rate limiting. 3887 if (peer->m_addr_token_bucket < 1.0) { 3888 if (rate_limited) { 3889 ++num_rate_limit; 3890 continue; 3891 } 3892 } else { 3893 peer->m_addr_token_bucket -= 1.0; 3894 } 3895 // We only bother storing full nodes, though this may include 3896 // things which we would not make an outbound connection to, in 3897 // part because we may make feeler connections to them. 3898 if (!MayHaveUsefulAddressDB(addr.nServices) && !HasAllDesirableServiceFlags(addr.nServices)) 3899 continue; 3900 3901 if (addr.nTime <= NodeSeconds{100000000s} || addr.nTime > current_a_time + 10min) { 3902 addr.nTime = current_a_time - 5 * 24h; 3903 } 3904 AddAddressKnown(*peer, addr); 3905 if (m_banman && (m_banman->IsDiscouraged(addr) || m_banman->IsBanned(addr))) { 3906 // Do not process banned/discouraged addresses beyond remembering we received them 3907 continue; 3908 } 3909 ++num_proc; 3910 const bool reachable{g_reachable_nets.Contains(addr)}; 3911 if (addr.nTime > current_a_time - 10min && !peer->m_getaddr_sent && vAddr.size() <= 10 && addr.IsRoutable()) { 3912 // Relay to a limited number of other nodes 3913 RelayAddress(pfrom.GetId(), addr, reachable); 3914 } 3915 // Do not store addresses outside our network 3916 if (reachable) { 3917 vAddrOk.push_back(addr); 3918 } 3919 } 3920 peer->m_addr_processed += num_proc; 3921 peer->m_addr_rate_limited += num_rate_limit; 3922 LogDebug(BCLog::NET, "Received addr: %u addresses (%u processed, %u rate-limited) from peer=%d\n", 3923 vAddr.size(), num_proc, num_rate_limit, pfrom.GetId()); 3924 3925 m_addrman.Add(vAddrOk, pfrom.addr, 2h); 3926 if (vAddr.size() < 1000) peer->m_getaddr_sent = false; 3927 3928 // AddrFetch: Require multiple addresses to avoid disconnecting on self-announcements 3929 if (pfrom.IsAddrFetchConn() && vAddr.size() > 1) { 3930 LogDebug(BCLog::NET, "addrfetch connection completed, %s\n", pfrom.DisconnectMsg(fLogIPs)); 3931 pfrom.fDisconnect = true; 3932 } 3933 return; 3934 } 3935 3936 if (msg_type == NetMsgType::INV) { 3937 std::vector<CInv> vInv; 3938 vRecv >> vInv; 3939 if (vInv.size() > MAX_INV_SZ) 3940 { 3941 Misbehaving(*peer, strprintf("inv message size = %u", vInv.size())); 3942 return; 3943 } 3944 3945 const bool reject_tx_invs{RejectIncomingTxs(pfrom)}; 3946 3947 LOCK2(cs_main, m_tx_download_mutex); 3948 3949 const auto current_time{GetTime<std::chrono::microseconds>()}; 3950 uint256* best_block{nullptr}; 3951 3952 for (CInv& inv : vInv) { 3953 if (interruptMsgProc) return; 3954 3955 // Ignore INVs that don't match wtxidrelay setting. 3956 // Note that orphan parent fetching always uses MSG_TX GETDATAs regardless of the wtxidrelay setting. 3957 // This is fine as no INV messages are involved in that process. 3958 if (peer->m_wtxid_relay) { 3959 if (inv.IsMsgTx()) continue; 3960 } else { 3961 if (inv.IsMsgWtx()) continue; 3962 } 3963 3964 if (inv.IsMsgBlk()) { 3965 const bool fAlreadyHave = AlreadyHaveBlock(inv.hash); 3966 LogDebug(BCLog::NET, "got inv: %s %s peer=%d\n", inv.ToString(), fAlreadyHave ? "have" : "new", pfrom.GetId()); 3967 3968 UpdateBlockAvailability(pfrom.GetId(), inv.hash); 3969 if (!fAlreadyHave && !m_chainman.m_blockman.LoadingBlocks() && !IsBlockRequested(inv.hash)) { 3970 // Headers-first is the primary method of announcement on 3971 // the network. If a node fell back to sending blocks by 3972 // inv, it may be for a re-org, or because we haven't 3973 // completed initial headers sync. The final block hash 3974 // provided should be the highest, so send a getheaders and 3975 // then fetch the blocks we need to catch up. 3976 best_block = &inv.hash; 3977 } 3978 } else if (inv.IsGenTxMsg()) { 3979 if (reject_tx_invs) { 3980 LogDebug(BCLog::NET, "transaction (%s) inv sent in violation of protocol, %s\n", inv.hash.ToString(), pfrom.DisconnectMsg(fLogIPs)); 3981 pfrom.fDisconnect = true; 3982 return; 3983 } 3984 const GenTxid gtxid = ToGenTxid(inv); 3985 AddKnownTx(*peer, inv.hash); 3986 3987 if (!m_chainman.IsInitialBlockDownload()) { 3988 const bool fAlreadyHave{m_txdownloadman.AddTxAnnouncement(pfrom.GetId(), gtxid, current_time)}; 3989 LogDebug(BCLog::NET, "got inv: %s %s peer=%d\n", inv.ToString(), fAlreadyHave ? "have" : "new", pfrom.GetId()); 3990 } 3991 } else { 3992 LogDebug(BCLog::NET, "Unknown inv type \"%s\" received from peer=%d\n", inv.ToString(), pfrom.GetId()); 3993 } 3994 } 3995 3996 if (best_block != nullptr) { 3997 // If we haven't started initial headers-sync with this peer, then 3998 // consider sending a getheaders now. On initial startup, there's a 3999 // reliability vs bandwidth tradeoff, where we are only trying to do 4000 // initial headers sync with one peer at a time, with a long 4001 // timeout (at which point, if the sync hasn't completed, we will 4002 // disconnect the peer and then choose another). In the meantime, 4003 // as new blocks are found, we are willing to add one new peer per 4004 // block to sync with as well, to sync quicker in the case where 4005 // our initial peer is unresponsive (but less bandwidth than we'd 4006 // use if we turned on sync with all peers). 4007 CNodeState& state{*Assert(State(pfrom.GetId()))}; 4008 if (state.fSyncStarted || (!peer->m_inv_triggered_getheaders_before_sync && *best_block != m_last_block_inv_triggering_headers_sync)) { 4009 if (MaybeSendGetHeaders(pfrom, GetLocator(m_chainman.m_best_header), *peer)) { 4010 LogDebug(BCLog::NET, "getheaders (%d) %s to peer=%d\n", 4011 m_chainman.m_best_header->nHeight, best_block->ToString(), 4012 pfrom.GetId()); 4013 } 4014 if (!state.fSyncStarted) { 4015 peer->m_inv_triggered_getheaders_before_sync = true; 4016 // Update the last block hash that triggered a new headers 4017 // sync, so that we don't turn on headers sync with more 4018 // than 1 new peer every new block. 4019 m_last_block_inv_triggering_headers_sync = *best_block; 4020 } 4021 } 4022 } 4023 4024 return; 4025 } 4026 4027 if (msg_type == NetMsgType::GETDATA) { 4028 std::vector<CInv> vInv; 4029 vRecv >> vInv; 4030 if (vInv.size() > MAX_INV_SZ) 4031 { 4032 Misbehaving(*peer, strprintf("getdata message size = %u", vInv.size())); 4033 return; 4034 } 4035 4036 LogDebug(BCLog::NET, "received getdata (%u invsz) peer=%d\n", vInv.size(), pfrom.GetId()); 4037 4038 if (vInv.size() > 0) { 4039 LogDebug(BCLog::NET, "received getdata for: %s peer=%d\n", vInv[0].ToString(), pfrom.GetId()); 4040 } 4041 4042 { 4043 LOCK(peer->m_getdata_requests_mutex); 4044 peer->m_getdata_requests.insert(peer->m_getdata_requests.end(), vInv.begin(), vInv.end()); 4045 ProcessGetData(pfrom, *peer, interruptMsgProc); 4046 } 4047 4048 return; 4049 } 4050 4051 if (msg_type == NetMsgType::GETBLOCKS) { 4052 CBlockLocator locator; 4053 uint256 hashStop; 4054 vRecv >> locator >> hashStop; 4055 4056 if (locator.vHave.size() > MAX_LOCATOR_SZ) { 4057 LogDebug(BCLog::NET, "getblocks locator size %lld > %d, %s\n", locator.vHave.size(), MAX_LOCATOR_SZ, pfrom.DisconnectMsg(fLogIPs)); 4058 pfrom.fDisconnect = true; 4059 return; 4060 } 4061 4062 // We might have announced the currently-being-connected tip using a 4063 // compact block, which resulted in the peer sending a getblocks 4064 // request, which we would otherwise respond to without the new block. 4065 // To avoid this situation we simply verify that we are on our best 4066 // known chain now. This is super overkill, but we handle it better 4067 // for getheaders requests, and there are no known nodes which support 4068 // compact blocks but still use getblocks to request blocks. 4069 { 4070 std::shared_ptr<const CBlock> a_recent_block; 4071 { 4072 LOCK(m_most_recent_block_mutex); 4073 a_recent_block = m_most_recent_block; 4074 } 4075 BlockValidationState state; 4076 if (!m_chainman.ActiveChainstate().ActivateBestChain(state, a_recent_block)) { 4077 LogDebug(BCLog::NET, "failed to activate chain (%s)\n", state.ToString()); 4078 } 4079 } 4080 4081 LOCK(cs_main); 4082 4083 // Find the last block the caller has in the main chain 4084 const CBlockIndex* pindex = m_chainman.ActiveChainstate().FindForkInGlobalIndex(locator); 4085 4086 // Send the rest of the chain 4087 if (pindex) 4088 pindex = m_chainman.ActiveChain().Next(pindex); 4089 int nLimit = 500; 4090 LogDebug(BCLog::NET, "getblocks %d to %s limit %d from peer=%d\n", (pindex ? pindex->nHeight : -1), hashStop.IsNull() ? "end" : hashStop.ToString(), nLimit, pfrom.GetId()); 4091 for (; pindex; pindex = m_chainman.ActiveChain().Next(pindex)) 4092 { 4093 if (pindex->GetBlockHash() == hashStop) 4094 { 4095 LogDebug(BCLog::NET, " getblocks stopping at %d %s\n", pindex->nHeight, pindex->GetBlockHash().ToString()); 4096 break; 4097 } 4098 // If pruning, don't inv blocks unless we have on disk and are likely to still have 4099 // for some reasonable time window (1 hour) that block relay might require. 4100 const int nPrunedBlocksLikelyToHave = MIN_BLOCKS_TO_KEEP - 3600 / m_chainparams.GetConsensus().nPowTargetSpacing; 4101 if (m_chainman.m_blockman.IsPruneMode() && (!(pindex->nStatus & BLOCK_HAVE_DATA) || pindex->nHeight <= m_chainman.ActiveChain().Tip()->nHeight - nPrunedBlocksLikelyToHave)) { 4102 LogDebug(BCLog::NET, " getblocks stopping, pruned or too old block at %d %s\n", pindex->nHeight, pindex->GetBlockHash().ToString()); 4103 break; 4104 } 4105 WITH_LOCK(peer->m_block_inv_mutex, peer->m_blocks_for_inv_relay.push_back(pindex->GetBlockHash())); 4106 if (--nLimit <= 0) { 4107 // When this block is requested, we'll send an inv that'll 4108 // trigger the peer to getblocks the next batch of inventory. 4109 LogDebug(BCLog::NET, " getblocks stopping at limit %d %s\n", pindex->nHeight, pindex->GetBlockHash().ToString()); 4110 WITH_LOCK(peer->m_block_inv_mutex, {peer->m_continuation_block = pindex->GetBlockHash();}); 4111 break; 4112 } 4113 } 4114 return; 4115 } 4116 4117 if (msg_type == NetMsgType::GETBLOCKTXN) { 4118 BlockTransactionsRequest req; 4119 vRecv >> req; 4120 // Verify differential encoding invariant: indexes must be strictly increasing 4121 // DifferenceFormatter should guarantee this property during deserialization 4122 for (size_t i = 1; i < req.indexes.size(); ++i) { 4123 Assume(req.indexes[i] > req.indexes[i-1]); 4124 } 4125 4126 std::shared_ptr<const CBlock> recent_block; 4127 { 4128 LOCK(m_most_recent_block_mutex); 4129 if (m_most_recent_block_hash == req.blockhash) 4130 recent_block = m_most_recent_block; 4131 // Unlock m_most_recent_block_mutex to avoid cs_main lock inversion 4132 } 4133 if (recent_block) { 4134 SendBlockTransactions(pfrom, *peer, *recent_block, req); 4135 return; 4136 } 4137 4138 FlatFilePos block_pos{}; 4139 { 4140 LOCK(cs_main); 4141 4142 const CBlockIndex* pindex = m_chainman.m_blockman.LookupBlockIndex(req.blockhash); 4143 if (!pindex || !(pindex->nStatus & BLOCK_HAVE_DATA)) { 4144 LogDebug(BCLog::NET, "Peer %d sent us a getblocktxn for a block we don't have\n", pfrom.GetId()); 4145 return; 4146 } 4147 4148 if (pindex->nHeight >= m_chainman.ActiveChain().Height() - MAX_BLOCKTXN_DEPTH) { 4149 block_pos = pindex->GetBlockPos(); 4150 } 4151 } 4152 4153 if (!block_pos.IsNull()) { 4154 CBlock block; 4155 const bool ret{m_chainman.m_blockman.ReadBlock(block, block_pos, req.blockhash)}; 4156 // If height is above MAX_BLOCKTXN_DEPTH then this block cannot get 4157 // pruned after we release cs_main above, so this read should never fail. 4158 assert(ret); 4159 4160 SendBlockTransactions(pfrom, *peer, block, req); 4161 return; 4162 } 4163 4164 // If an older block is requested (should never happen in practice, 4165 // but can happen in tests) send a block response instead of a 4166 // blocktxn response. Sending a full block response instead of a 4167 // small blocktxn response is preferable in the case where a peer 4168 // might maliciously send lots of getblocktxn requests to trigger 4169 // expensive disk reads, because it will require the peer to 4170 // actually receive all the data read from disk over the network. 4171 LogDebug(BCLog::NET, "Peer %d sent us a getblocktxn for a block > %i deep\n", pfrom.GetId(), MAX_BLOCKTXN_DEPTH); 4172 CInv inv{MSG_WITNESS_BLOCK, req.blockhash}; 4173 WITH_LOCK(peer->m_getdata_requests_mutex, peer->m_getdata_requests.push_back(inv)); 4174 // The message processing loop will go around again (without pausing) and we'll respond then 4175 return; 4176 } 4177 4178 if (msg_type == NetMsgType::GETHEADERS) { 4179 CBlockLocator locator; 4180 uint256 hashStop; 4181 vRecv >> locator >> hashStop; 4182 4183 if (locator.vHave.size() > MAX_LOCATOR_SZ) { 4184 LogDebug(BCLog::NET, "getheaders locator size %lld > %d, %s\n", locator.vHave.size(), MAX_LOCATOR_SZ, pfrom.DisconnectMsg(fLogIPs)); 4185 pfrom.fDisconnect = true; 4186 return; 4187 } 4188 4189 if (m_chainman.m_blockman.LoadingBlocks()) { 4190 LogDebug(BCLog::NET, "Ignoring getheaders from peer=%d while importing/reindexing\n", pfrom.GetId()); 4191 return; 4192 } 4193 4194 LOCK(cs_main); 4195 4196 // Don't serve headers from our active chain until our chainwork is at least 4197 // the minimum chain work. This prevents us from starting a low-work headers 4198 // sync that will inevitably be aborted by our peer. 4199 if (m_chainman.ActiveTip() == nullptr || 4200 (m_chainman.ActiveTip()->nChainWork < m_chainman.MinimumChainWork() && !pfrom.HasPermission(NetPermissionFlags::Download))) { 4201 LogDebug(BCLog::NET, "Ignoring getheaders from peer=%d because active chain has too little work; sending empty response\n", pfrom.GetId()); 4202 // Just respond with an empty headers message, to tell the peer to 4203 // go away but not treat us as unresponsive. 4204 MakeAndPushMessage(pfrom, NetMsgType::HEADERS, std::vector<CBlockHeader>()); 4205 return; 4206 } 4207 4208 CNodeState *nodestate = State(pfrom.GetId()); 4209 const CBlockIndex* pindex = nullptr; 4210 if (locator.IsNull()) 4211 { 4212 // If locator is null, return the hashStop block 4213 pindex = m_chainman.m_blockman.LookupBlockIndex(hashStop); 4214 if (!pindex) { 4215 return; 4216 } 4217 4218 if (!BlockRequestAllowed(pindex)) { 4219 LogDebug(BCLog::NET, "%s: ignoring request from peer=%i for old block header that isn't in the main chain\n", __func__, pfrom.GetId()); 4220 return; 4221 } 4222 } 4223 else 4224 { 4225 // Find the last block the caller has in the main chain 4226 pindex = m_chainman.ActiveChainstate().FindForkInGlobalIndex(locator); 4227 if (pindex) 4228 pindex = m_chainman.ActiveChain().Next(pindex); 4229 } 4230 4231 // we must use CBlocks, as CBlockHeaders won't include the 0x00 nTx count at the end 4232 std::vector<CBlock> vHeaders; 4233 int nLimit = m_opts.max_headers_result; 4234 LogDebug(BCLog::NET, "getheaders %d to %s from peer=%d\n", (pindex ? pindex->nHeight : -1), hashStop.IsNull() ? "end" : hashStop.ToString(), pfrom.GetId()); 4235 for (; pindex; pindex = m_chainman.ActiveChain().Next(pindex)) 4236 { 4237 vHeaders.emplace_back(pindex->GetBlockHeader()); 4238 if (--nLimit <= 0 || pindex->GetBlockHash() == hashStop) 4239 break; 4240 } 4241 // pindex can be nullptr either if we sent m_chainman.ActiveChain().Tip() OR 4242 // if our peer has m_chainman.ActiveChain().Tip() (and thus we are sending an empty 4243 // headers message). In both cases it's safe to update 4244 // pindexBestHeaderSent to be our tip. 4245 // 4246 // It is important that we simply reset the BestHeaderSent value here, 4247 // and not max(BestHeaderSent, newHeaderSent). We might have announced 4248 // the currently-being-connected tip using a compact block, which 4249 // resulted in the peer sending a headers request, which we respond to 4250 // without the new block. By resetting the BestHeaderSent, we ensure we 4251 // will re-announce the new block via headers (or compact blocks again) 4252 // in the SendMessages logic. 4253 nodestate->pindexBestHeaderSent = pindex ? pindex : m_chainman.ActiveChain().Tip(); 4254 MakeAndPushMessage(pfrom, NetMsgType::HEADERS, TX_WITH_WITNESS(vHeaders)); 4255 return; 4256 } 4257 4258 if (msg_type == NetMsgType::TX) { 4259 if (RejectIncomingTxs(pfrom)) { 4260 LogDebug(BCLog::NET, "transaction sent in violation of protocol, %s", pfrom.DisconnectMsg(fLogIPs)); 4261 pfrom.fDisconnect = true; 4262 return; 4263 } 4264 4265 // Stop processing the transaction early if we are still in IBD since we don't 4266 // have enough information to validate it yet. Sending unsolicited transactions 4267 // is not considered a protocol violation, so don't punish the peer. 4268 if (m_chainman.IsInitialBlockDownload()) return; 4269 4270 CTransactionRef ptx; 4271 vRecv >> TX_WITH_WITNESS(ptx); 4272 4273 const Txid& txid = ptx->GetHash(); 4274 const Wtxid& wtxid = ptx->GetWitnessHash(); 4275 4276 const uint256& hash = peer->m_wtxid_relay ? wtxid.ToUint256() : txid.ToUint256(); 4277 AddKnownTx(*peer, hash); 4278 4279 LOCK2(cs_main, m_tx_download_mutex); 4280 4281 const auto& [should_validate, package_to_validate] = m_txdownloadman.ReceivedTx(pfrom.GetId(), ptx); 4282 if (!should_validate) { 4283 if (pfrom.HasPermission(NetPermissionFlags::ForceRelay)) { 4284 // Always relay transactions received from peers with forcerelay 4285 // permission, even if they were already in the mempool, allowing 4286 // the node to function as a gateway for nodes hidden behind it. 4287 if (!m_mempool.exists(txid)) { 4288 LogPrintf("Not relaying non-mempool transaction %s (wtxid=%s) from forcerelay peer=%d\n", 4289 txid.ToString(), wtxid.ToString(), pfrom.GetId()); 4290 } else { 4291 LogPrintf("Force relaying tx %s (wtxid=%s) from peer=%d\n", 4292 txid.ToString(), wtxid.ToString(), pfrom.GetId()); 4293 RelayTransaction(txid, wtxid); 4294 } 4295 } 4296 4297 if (package_to_validate) { 4298 const auto package_result{ProcessNewPackage(m_chainman.ActiveChainstate(), m_mempool, package_to_validate->m_txns, /*test_accept=*/false, /*client_maxfeerate=*/std::nullopt)}; 4299 LogDebug(BCLog::TXPACKAGES, "package evaluation for %s: %s\n", package_to_validate->ToString(), 4300 package_result.m_state.IsValid() ? "package accepted" : "package rejected"); 4301 ProcessPackageResult(package_to_validate.value(), package_result); 4302 } 4303 return; 4304 } 4305 4306 // ReceivedTx should not be telling us to validate the tx and a package. 4307 Assume(!package_to_validate.has_value()); 4308 4309 const MempoolAcceptResult result = m_chainman.ProcessTransaction(ptx); 4310 const TxValidationState& state = result.m_state; 4311 4312 if (result.m_result_type == MempoolAcceptResult::ResultType::VALID) { 4313 ProcessValidTx(pfrom.GetId(), ptx, result.m_replaced_transactions); 4314 pfrom.m_last_tx_time = GetTime<std::chrono::seconds>(); 4315 } 4316 if (state.IsInvalid()) { 4317 if (auto package_to_validate{ProcessInvalidTx(pfrom.GetId(), ptx, state, /*first_time_failure=*/true)}) { 4318 const auto package_result{ProcessNewPackage(m_chainman.ActiveChainstate(), m_mempool, package_to_validate->m_txns, /*test_accept=*/false, /*client_maxfeerate=*/std::nullopt)}; 4319 LogDebug(BCLog::TXPACKAGES, "package evaluation for %s: %s\n", package_to_validate->ToString(), 4320 package_result.m_state.IsValid() ? "package accepted" : "package rejected"); 4321 ProcessPackageResult(package_to_validate.value(), package_result); 4322 } 4323 } 4324 4325 return; 4326 } 4327 4328 if (msg_type == NetMsgType::CMPCTBLOCK) 4329 { 4330 // Ignore cmpctblock received while importing 4331 if (m_chainman.m_blockman.LoadingBlocks()) { 4332 LogDebug(BCLog::NET, "Unexpected cmpctblock message received from peer %d\n", pfrom.GetId()); 4333 return; 4334 } 4335 4336 CBlockHeaderAndShortTxIDs cmpctblock; 4337 vRecv >> cmpctblock; 4338 4339 bool received_new_header = false; 4340 const auto blockhash = cmpctblock.header.GetHash(); 4341 4342 { 4343 LOCK(cs_main); 4344 4345 const CBlockIndex* prev_block = m_chainman.m_blockman.LookupBlockIndex(cmpctblock.header.hashPrevBlock); 4346 if (!prev_block) { 4347 // Doesn't connect (or is genesis), instead of DoSing in AcceptBlockHeader, request deeper headers 4348 if (!m_chainman.IsInitialBlockDownload()) { 4349 MaybeSendGetHeaders(pfrom, GetLocator(m_chainman.m_best_header), *peer); 4350 } 4351 return; 4352 } else if (prev_block->nChainWork + CalculateClaimedHeadersWork({{cmpctblock.header}}) < GetAntiDoSWorkThreshold()) { 4353 // If we get a low-work header in a compact block, we can ignore it. 4354 LogDebug(BCLog::NET, "Ignoring low-work compact block from peer %d\n", pfrom.GetId()); 4355 return; 4356 } 4357 4358 if (!m_chainman.m_blockman.LookupBlockIndex(blockhash)) { 4359 received_new_header = true; 4360 } 4361 } 4362 4363 const CBlockIndex *pindex = nullptr; 4364 BlockValidationState state; 4365 if (!m_chainman.ProcessNewBlockHeaders({{cmpctblock.header}}, /*min_pow_checked=*/true, state, &pindex)) { 4366 if (state.IsInvalid()) { 4367 MaybePunishNodeForBlock(pfrom.GetId(), state, /*via_compact_block=*/true, "invalid header via cmpctblock"); 4368 return; 4369 } 4370 } 4371 4372 // If AcceptBlockHeader returned true, it set pindex 4373 Assert(pindex); 4374 if (received_new_header) { 4375 LogBlockHeader(*pindex, pfrom, /*via_compact_block=*/true); 4376 } 4377 4378 bool fProcessBLOCKTXN = false; 4379 4380 // If we end up treating this as a plain headers message, call that as well 4381 // without cs_main. 4382 bool fRevertToHeaderProcessing = false; 4383 4384 // Keep a CBlock for "optimistic" compactblock reconstructions (see 4385 // below) 4386 std::shared_ptr<CBlock> pblock = std::make_shared<CBlock>(); 4387 bool fBlockReconstructed = false; 4388 4389 { 4390 LOCK(cs_main); 4391 UpdateBlockAvailability(pfrom.GetId(), pindex->GetBlockHash()); 4392 4393 CNodeState *nodestate = State(pfrom.GetId()); 4394 4395 // If this was a new header with more work than our tip, update the 4396 // peer's last block announcement time 4397 if (received_new_header && pindex->nChainWork > m_chainman.ActiveChain().Tip()->nChainWork) { 4398 nodestate->m_last_block_announcement = GetTime(); 4399 } 4400 4401 if (pindex->nStatus & BLOCK_HAVE_DATA) // Nothing to do here 4402 return; 4403 4404 auto range_flight = mapBlocksInFlight.equal_range(pindex->GetBlockHash()); 4405 size_t already_in_flight = std::distance(range_flight.first, range_flight.second); 4406 bool requested_block_from_this_peer{false}; 4407 4408 // Multimap ensures ordering of outstanding requests. It's either empty or first in line. 4409 bool first_in_flight = already_in_flight == 0 || (range_flight.first->second.first == pfrom.GetId()); 4410 4411 while (range_flight.first != range_flight.second) { 4412 if (range_flight.first->second.first == pfrom.GetId()) { 4413 requested_block_from_this_peer = true; 4414 break; 4415 } 4416 range_flight.first++; 4417 } 4418 4419 if (pindex->nChainWork <= m_chainman.ActiveChain().Tip()->nChainWork || // We know something better 4420 pindex->nTx != 0) { // We had this block at some point, but pruned it 4421 if (requested_block_from_this_peer) { 4422 // We requested this block for some reason, but our mempool will probably be useless 4423 // so we just grab the block via normal getdata 4424 std::vector<CInv> vInv(1); 4425 vInv[0] = CInv(MSG_BLOCK | GetFetchFlags(*peer), blockhash); 4426 MakeAndPushMessage(pfrom, NetMsgType::GETDATA, vInv); 4427 } 4428 return; 4429 } 4430 4431 // If we're not close to tip yet, give up and let parallel block fetch work its magic 4432 if (!already_in_flight && !CanDirectFetch()) { 4433 return; 4434 } 4435 4436 // We want to be a bit conservative just to be extra careful about DoS 4437 // possibilities in compact block processing... 4438 if (pindex->nHeight <= m_chainman.ActiveChain().Height() + 2) { 4439 if ((already_in_flight < MAX_CMPCTBLOCKS_INFLIGHT_PER_BLOCK && nodestate->vBlocksInFlight.size() < MAX_BLOCKS_IN_TRANSIT_PER_PEER) || 4440 requested_block_from_this_peer) { 4441 std::list<QueuedBlock>::iterator* queuedBlockIt = nullptr; 4442 if (!BlockRequested(pfrom.GetId(), *pindex, &queuedBlockIt)) { 4443 if (!(*queuedBlockIt)->partialBlock) 4444 (*queuedBlockIt)->partialBlock.reset(new PartiallyDownloadedBlock(&m_mempool)); 4445 else { 4446 // The block was already in flight using compact blocks from the same peer 4447 LogDebug(BCLog::NET, "Peer sent us compact block we were already syncing!\n"); 4448 return; 4449 } 4450 } 4451 4452 PartiallyDownloadedBlock& partialBlock = *(*queuedBlockIt)->partialBlock; 4453 ReadStatus status = partialBlock.InitData(cmpctblock, vExtraTxnForCompact); 4454 if (status == READ_STATUS_INVALID) { 4455 RemoveBlockRequest(pindex->GetBlockHash(), pfrom.GetId()); // Reset in-flight state in case Misbehaving does not result in a disconnect 4456 Misbehaving(*peer, "invalid compact block"); 4457 return; 4458 } else if (status == READ_STATUS_FAILED) { 4459 if (first_in_flight) { 4460 // Duplicate txindexes, the block is now in-flight, so just request it 4461 std::vector<CInv> vInv(1); 4462 vInv[0] = CInv(MSG_BLOCK | GetFetchFlags(*peer), blockhash); 4463 MakeAndPushMessage(pfrom, NetMsgType::GETDATA, vInv); 4464 } else { 4465 // Give up for this peer and wait for other peer(s) 4466 RemoveBlockRequest(pindex->GetBlockHash(), pfrom.GetId()); 4467 } 4468 return; 4469 } 4470 4471 BlockTransactionsRequest req; 4472 for (size_t i = 0; i < cmpctblock.BlockTxCount(); i++) { 4473 if (!partialBlock.IsTxAvailable(i)) 4474 req.indexes.push_back(i); 4475 } 4476 if (req.indexes.empty()) { 4477 fProcessBLOCKTXN = true; 4478 } else if (first_in_flight) { 4479 // We will try to round-trip any compact blocks we get on failure, 4480 // as long as it's first... 4481 req.blockhash = pindex->GetBlockHash(); 4482 MakeAndPushMessage(pfrom, NetMsgType::GETBLOCKTXN, req); 4483 } else if (pfrom.m_bip152_highbandwidth_to && 4484 (!pfrom.IsInboundConn() || 4485 IsBlockRequestedFromOutbound(blockhash) || 4486 already_in_flight < MAX_CMPCTBLOCKS_INFLIGHT_PER_BLOCK - 1)) { 4487 // ... or it's a hb relay peer and: 4488 // - peer is outbound, or 4489 // - we already have an outbound attempt in flight(so we'll take what we can get), or 4490 // - it's not the final parallel download slot (which we may reserve for first outbound) 4491 req.blockhash = pindex->GetBlockHash(); 4492 MakeAndPushMessage(pfrom, NetMsgType::GETBLOCKTXN, req); 4493 } else { 4494 // Give up for this peer and wait for other peer(s) 4495 RemoveBlockRequest(pindex->GetBlockHash(), pfrom.GetId()); 4496 } 4497 } else { 4498 // This block is either already in flight from a different 4499 // peer, or this peer has too many blocks outstanding to 4500 // download from. 4501 // Optimistically try to reconstruct anyway since we might be 4502 // able to without any round trips. 4503 PartiallyDownloadedBlock tempBlock(&m_mempool); 4504 ReadStatus status = tempBlock.InitData(cmpctblock, vExtraTxnForCompact); 4505 if (status != READ_STATUS_OK) { 4506 // TODO: don't ignore failures 4507 return; 4508 } 4509 std::vector<CTransactionRef> dummy; 4510 const CBlockIndex* prev_block{Assume(m_chainman.m_blockman.LookupBlockIndex(cmpctblock.header.hashPrevBlock))}; 4511 status = tempBlock.FillBlock(*pblock, dummy, 4512 /*segwit_active=*/DeploymentActiveAfter(prev_block, m_chainman, Consensus::DEPLOYMENT_SEGWIT)); 4513 if (status == READ_STATUS_OK) { 4514 fBlockReconstructed = true; 4515 } 4516 } 4517 } else { 4518 if (requested_block_from_this_peer) { 4519 // We requested this block, but its far into the future, so our 4520 // mempool will probably be useless - request the block normally 4521 std::vector<CInv> vInv(1); 4522 vInv[0] = CInv(MSG_BLOCK | GetFetchFlags(*peer), blockhash); 4523 MakeAndPushMessage(pfrom, NetMsgType::GETDATA, vInv); 4524 return; 4525 } else { 4526 // If this was an announce-cmpctblock, we want the same treatment as a header message 4527 fRevertToHeaderProcessing = true; 4528 } 4529 } 4530 } // cs_main 4531 4532 if (fProcessBLOCKTXN) { 4533 BlockTransactions txn; 4534 txn.blockhash = blockhash; 4535 return ProcessCompactBlockTxns(pfrom, *peer, txn); 4536 } 4537 4538 if (fRevertToHeaderProcessing) { 4539 // Headers received from HB compact block peers are permitted to be 4540 // relayed before full validation (see BIP 152), so we don't want to disconnect 4541 // the peer if the header turns out to be for an invalid block. 4542 // Note that if a peer tries to build on an invalid chain, that 4543 // will be detected and the peer will be disconnected/discouraged. 4544 return ProcessHeadersMessage(pfrom, *peer, {cmpctblock.header}, /*via_compact_block=*/true); 4545 } 4546 4547 if (fBlockReconstructed) { 4548 // If we got here, we were able to optimistically reconstruct a 4549 // block that is in flight from some other peer. 4550 { 4551 LOCK(cs_main); 4552 mapBlockSource.emplace(pblock->GetHash(), std::make_pair(pfrom.GetId(), false)); 4553 } 4554 // Setting force_processing to true means that we bypass some of 4555 // our anti-DoS protections in AcceptBlock, which filters 4556 // unrequested blocks that might be trying to waste our resources 4557 // (eg disk space). Because we only try to reconstruct blocks when 4558 // we're close to caught up (via the CanDirectFetch() requirement 4559 // above, combined with the behavior of not requesting blocks until 4560 // we have a chain with at least the minimum chain work), and we ignore 4561 // compact blocks with less work than our tip, it is safe to treat 4562 // reconstructed compact blocks as having been requested. 4563 ProcessBlock(pfrom, pblock, /*force_processing=*/true, /*min_pow_checked=*/true); 4564 LOCK(cs_main); // hold cs_main for CBlockIndex::IsValid() 4565 if (pindex->IsValid(BLOCK_VALID_TRANSACTIONS)) { 4566 // Clear download state for this block, which is in 4567 // process from some other peer. We do this after calling 4568 // ProcessNewBlock so that a malleated cmpctblock announcement 4569 // can't be used to interfere with block relay. 4570 RemoveBlockRequest(pblock->GetHash(), std::nullopt); 4571 } 4572 } 4573 return; 4574 } 4575 4576 if (msg_type == NetMsgType::BLOCKTXN) 4577 { 4578 // Ignore blocktxn received while importing 4579 if (m_chainman.m_blockman.LoadingBlocks()) { 4580 LogDebug(BCLog::NET, "Unexpected blocktxn message received from peer %d\n", pfrom.GetId()); 4581 return; 4582 } 4583 4584 BlockTransactions resp; 4585 vRecv >> resp; 4586 4587 return ProcessCompactBlockTxns(pfrom, *peer, resp); 4588 } 4589 4590 if (msg_type == NetMsgType::HEADERS) 4591 { 4592 // Ignore headers received while importing 4593 if (m_chainman.m_blockman.LoadingBlocks()) { 4594 LogDebug(BCLog::NET, "Unexpected headers message received from peer %d\n", pfrom.GetId()); 4595 return; 4596 } 4597 4598 std::vector<CBlockHeader> headers; 4599 4600 // Bypass the normal CBlock deserialization, as we don't want to risk deserializing 2000 full blocks. 4601 unsigned int nCount = ReadCompactSize(vRecv); 4602 if (nCount > m_opts.max_headers_result) { 4603 Misbehaving(*peer, strprintf("headers message size = %u", nCount)); 4604 return; 4605 } 4606 headers.resize(nCount); 4607 for (unsigned int n = 0; n < nCount; n++) { 4608 vRecv >> headers[n]; 4609 ReadCompactSize(vRecv); // ignore tx count; assume it is 0. 4610 } 4611 4612 ProcessHeadersMessage(pfrom, *peer, std::move(headers), /*via_compact_block=*/false); 4613 4614 // Check if the headers presync progress needs to be reported to validation. 4615 // This needs to be done without holding the m_headers_presync_mutex lock. 4616 if (m_headers_presync_should_signal.exchange(false)) { 4617 HeadersPresyncStats stats; 4618 { 4619 LOCK(m_headers_presync_mutex); 4620 auto it = m_headers_presync_stats.find(m_headers_presync_bestpeer); 4621 if (it != m_headers_presync_stats.end()) stats = it->second; 4622 } 4623 if (stats.second) { 4624 m_chainman.ReportHeadersPresync(stats.first, stats.second->first, stats.second->second); 4625 } 4626 } 4627 4628 return; 4629 } 4630 4631 if (msg_type == NetMsgType::BLOCK) 4632 { 4633 // Ignore block received while importing 4634 if (m_chainman.m_blockman.LoadingBlocks()) { 4635 LogDebug(BCLog::NET, "Unexpected block message received from peer %d\n", pfrom.GetId()); 4636 return; 4637 } 4638 4639 std::shared_ptr<CBlock> pblock = std::make_shared<CBlock>(); 4640 vRecv >> TX_WITH_WITNESS(*pblock); 4641 4642 LogDebug(BCLog::NET, "received block %s peer=%d\n", pblock->GetHash().ToString(), pfrom.GetId()); 4643 4644 const CBlockIndex* prev_block{WITH_LOCK(m_chainman.GetMutex(), return m_chainman.m_blockman.LookupBlockIndex(pblock->hashPrevBlock))}; 4645 4646 // Check for possible mutation if it connects to something we know so we can check for DEPLOYMENT_SEGWIT being active 4647 if (prev_block && IsBlockMutated(/*block=*/*pblock, 4648 /*check_witness_root=*/DeploymentActiveAfter(prev_block, m_chainman, Consensus::DEPLOYMENT_SEGWIT))) { 4649 LogDebug(BCLog::NET, "Received mutated block from peer=%d\n", peer->m_id); 4650 Misbehaving(*peer, "mutated block"); 4651 WITH_LOCK(cs_main, RemoveBlockRequest(pblock->GetHash(), peer->m_id)); 4652 return; 4653 } 4654 4655 bool forceProcessing = false; 4656 const uint256 hash(pblock->GetHash()); 4657 bool min_pow_checked = false; 4658 { 4659 LOCK(cs_main); 4660 // Always process the block if we requested it, since we may 4661 // need it even when it's not a candidate for a new best tip. 4662 forceProcessing = IsBlockRequested(hash); 4663 RemoveBlockRequest(hash, pfrom.GetId()); 4664 // mapBlockSource is only used for punishing peers and setting 4665 // which peers send us compact blocks, so the race between here and 4666 // cs_main in ProcessNewBlock is fine. 4667 mapBlockSource.emplace(hash, std::make_pair(pfrom.GetId(), true)); 4668 4669 // Check claimed work on this block against our anti-dos thresholds. 4670 if (prev_block && prev_block->nChainWork + CalculateClaimedHeadersWork({{pblock->GetBlockHeader()}}) >= GetAntiDoSWorkThreshold()) { 4671 min_pow_checked = true; 4672 } 4673 } 4674 ProcessBlock(pfrom, pblock, forceProcessing, min_pow_checked); 4675 return; 4676 } 4677 4678 if (msg_type == NetMsgType::GETADDR) { 4679 // This asymmetric behavior for inbound and outbound connections was introduced 4680 // to prevent a fingerprinting attack: an attacker can send specific fake addresses 4681 // to users' AddrMan and later request them by sending getaddr messages. 4682 // Making nodes which are behind NAT and can only make outgoing connections ignore 4683 // the getaddr message mitigates the attack. 4684 if (!pfrom.IsInboundConn()) { 4685 LogDebug(BCLog::NET, "Ignoring \"getaddr\" from %s connection. peer=%d\n", pfrom.ConnectionTypeAsString(), pfrom.GetId()); 4686 return; 4687 } 4688 4689 // Since this must be an inbound connection, SetupAddressRelay will 4690 // never fail. 4691 Assume(SetupAddressRelay(pfrom, *peer)); 4692 4693 // Only send one GetAddr response per connection to reduce resource waste 4694 // and discourage addr stamping of INV announcements. 4695 if (peer->m_getaddr_recvd) { 4696 LogDebug(BCLog::NET, "Ignoring repeated \"getaddr\". peer=%d\n", pfrom.GetId()); 4697 return; 4698 } 4699 peer->m_getaddr_recvd = true; 4700 4701 peer->m_addrs_to_send.clear(); 4702 std::vector<CAddress> vAddr; 4703 if (pfrom.HasPermission(NetPermissionFlags::Addr)) { 4704 vAddr = m_connman.GetAddressesUnsafe(MAX_ADDR_TO_SEND, MAX_PCT_ADDR_TO_SEND, /*network=*/std::nullopt); 4705 } else { 4706 vAddr = m_connman.GetAddresses(pfrom, MAX_ADDR_TO_SEND, MAX_PCT_ADDR_TO_SEND); 4707 } 4708 for (const CAddress &addr : vAddr) { 4709 PushAddress(*peer, addr); 4710 } 4711 return; 4712 } 4713 4714 if (msg_type == NetMsgType::MEMPOOL) { 4715 // Only process received mempool messages if we advertise NODE_BLOOM 4716 // or if the peer has mempool permissions. 4717 if (!(peer->m_our_services & NODE_BLOOM) && !pfrom.HasPermission(NetPermissionFlags::Mempool)) 4718 { 4719 if (!pfrom.HasPermission(NetPermissionFlags::NoBan)) 4720 { 4721 LogDebug(BCLog::NET, "mempool request with bloom filters disabled, %s\n", pfrom.DisconnectMsg(fLogIPs)); 4722 pfrom.fDisconnect = true; 4723 } 4724 return; 4725 } 4726 4727 if (m_connman.OutboundTargetReached(false) && !pfrom.HasPermission(NetPermissionFlags::Mempool)) 4728 { 4729 if (!pfrom.HasPermission(NetPermissionFlags::NoBan)) 4730 { 4731 LogDebug(BCLog::NET, "mempool request with bandwidth limit reached, %s\n", pfrom.DisconnectMsg(fLogIPs)); 4732 pfrom.fDisconnect = true; 4733 } 4734 return; 4735 } 4736 4737 if (auto tx_relay = peer->GetTxRelay(); tx_relay != nullptr) { 4738 LOCK(tx_relay->m_tx_inventory_mutex); 4739 tx_relay->m_send_mempool = true; 4740 } 4741 return; 4742 } 4743 4744 if (msg_type == NetMsgType::PING) { 4745 if (pfrom.GetCommonVersion() > BIP0031_VERSION) { 4746 uint64_t nonce = 0; 4747 vRecv >> nonce; 4748 // Echo the message back with the nonce. This allows for two useful features: 4749 // 4750 // 1) A remote node can quickly check if the connection is operational 4751 // 2) Remote nodes can measure the latency of the network thread. If this node 4752 // is overloaded it won't respond to pings quickly and the remote node can 4753 // avoid sending us more work, like chain download requests. 4754 // 4755 // The nonce stops the remote getting confused between different pings: without 4756 // it, if the remote node sends a ping once per second and this node takes 5 4757 // seconds to respond to each, the 5th ping the remote sends would appear to 4758 // return very quickly. 4759 MakeAndPushMessage(pfrom, NetMsgType::PONG, nonce); 4760 } 4761 return; 4762 } 4763 4764 if (msg_type == NetMsgType::PONG) { 4765 const auto ping_end = time_received; 4766 uint64_t nonce = 0; 4767 size_t nAvail = vRecv.in_avail(); 4768 bool bPingFinished = false; 4769 std::string sProblem; 4770 4771 if (nAvail >= sizeof(nonce)) { 4772 vRecv >> nonce; 4773 4774 // Only process pong message if there is an outstanding ping (old ping without nonce should never pong) 4775 if (peer->m_ping_nonce_sent != 0) { 4776 if (nonce == peer->m_ping_nonce_sent) { 4777 // Matching pong received, this ping is no longer outstanding 4778 bPingFinished = true; 4779 const auto ping_time = ping_end - peer->m_ping_start.load(); 4780 if (ping_time.count() >= 0) { 4781 // Let connman know about this successful ping-pong 4782 pfrom.PongReceived(ping_time); 4783 } else { 4784 // This should never happen 4785 sProblem = "Timing mishap"; 4786 } 4787 } else { 4788 // Nonce mismatches are normal when pings are overlapping 4789 sProblem = "Nonce mismatch"; 4790 if (nonce == 0) { 4791 // This is most likely a bug in another implementation somewhere; cancel this ping 4792 bPingFinished = true; 4793 sProblem = "Nonce zero"; 4794 } 4795 } 4796 } else { 4797 sProblem = "Unsolicited pong without ping"; 4798 } 4799 } else { 4800 // This is most likely a bug in another implementation somewhere; cancel this ping 4801 bPingFinished = true; 4802 sProblem = "Short payload"; 4803 } 4804 4805 if (!(sProblem.empty())) { 4806 LogDebug(BCLog::NET, "pong peer=%d: %s, %x expected, %x received, %u bytes\n", 4807 pfrom.GetId(), 4808 sProblem, 4809 peer->m_ping_nonce_sent, 4810 nonce, 4811 nAvail); 4812 } 4813 if (bPingFinished) { 4814 peer->m_ping_nonce_sent = 0; 4815 } 4816 return; 4817 } 4818 4819 if (msg_type == NetMsgType::FILTERLOAD) { 4820 if (!(peer->m_our_services & NODE_BLOOM)) { 4821 LogDebug(BCLog::NET, "filterload received despite not offering bloom services, %s\n", pfrom.DisconnectMsg(fLogIPs)); 4822 pfrom.fDisconnect = true; 4823 return; 4824 } 4825 CBloomFilter filter; 4826 vRecv >> filter; 4827 4828 if (!filter.IsWithinSizeConstraints()) 4829 { 4830 // There is no excuse for sending a too-large filter 4831 Misbehaving(*peer, "too-large bloom filter"); 4832 } else if (auto tx_relay = peer->GetTxRelay(); tx_relay != nullptr) { 4833 { 4834 LOCK(tx_relay->m_bloom_filter_mutex); 4835 tx_relay->m_bloom_filter.reset(new CBloomFilter(filter)); 4836 tx_relay->m_relay_txs = true; 4837 } 4838 pfrom.m_bloom_filter_loaded = true; 4839 pfrom.m_relays_txs = true; 4840 } 4841 return; 4842 } 4843 4844 if (msg_type == NetMsgType::FILTERADD) { 4845 if (!(peer->m_our_services & NODE_BLOOM)) { 4846 LogDebug(BCLog::NET, "filteradd received despite not offering bloom services, %s\n", pfrom.DisconnectMsg(fLogIPs)); 4847 pfrom.fDisconnect = true; 4848 return; 4849 } 4850 std::vector<unsigned char> vData; 4851 vRecv >> vData; 4852 4853 // Nodes must NEVER send a data item > MAX_SCRIPT_ELEMENT_SIZE bytes (the max size for a script data object, 4854 // and thus, the maximum size any matched object can have) in a filteradd message 4855 bool bad = false; 4856 if (vData.size() > MAX_SCRIPT_ELEMENT_SIZE) { 4857 bad = true; 4858 } else if (auto tx_relay = peer->GetTxRelay(); tx_relay != nullptr) { 4859 LOCK(tx_relay->m_bloom_filter_mutex); 4860 if (tx_relay->m_bloom_filter) { 4861 tx_relay->m_bloom_filter->insert(vData); 4862 } else { 4863 bad = true; 4864 } 4865 } 4866 if (bad) { 4867 Misbehaving(*peer, "bad filteradd message"); 4868 } 4869 return; 4870 } 4871 4872 if (msg_type == NetMsgType::FILTERCLEAR) { 4873 if (!(peer->m_our_services & NODE_BLOOM)) { 4874 LogDebug(BCLog::NET, "filterclear received despite not offering bloom services, %s\n", pfrom.DisconnectMsg(fLogIPs)); 4875 pfrom.fDisconnect = true; 4876 return; 4877 } 4878 auto tx_relay = peer->GetTxRelay(); 4879 if (!tx_relay) return; 4880 4881 { 4882 LOCK(tx_relay->m_bloom_filter_mutex); 4883 tx_relay->m_bloom_filter = nullptr; 4884 tx_relay->m_relay_txs = true; 4885 } 4886 pfrom.m_bloom_filter_loaded = false; 4887 pfrom.m_relays_txs = true; 4888 return; 4889 } 4890 4891 if (msg_type == NetMsgType::FEEFILTER) { 4892 CAmount newFeeFilter = 0; 4893 vRecv >> newFeeFilter; 4894 if (MoneyRange(newFeeFilter)) { 4895 if (auto tx_relay = peer->GetTxRelay(); tx_relay != nullptr) { 4896 tx_relay->m_fee_filter_received = newFeeFilter; 4897 } 4898 LogDebug(BCLog::NET, "received: feefilter of %s from peer=%d\n", CFeeRate(newFeeFilter).ToString(), pfrom.GetId()); 4899 } 4900 return; 4901 } 4902 4903 if (msg_type == NetMsgType::GETCFILTERS) { 4904 ProcessGetCFilters(pfrom, *peer, vRecv); 4905 return; 4906 } 4907 4908 if (msg_type == NetMsgType::GETCFHEADERS) { 4909 ProcessGetCFHeaders(pfrom, *peer, vRecv); 4910 return; 4911 } 4912 4913 if (msg_type == NetMsgType::GETCFCHECKPT) { 4914 ProcessGetCFCheckPt(pfrom, *peer, vRecv); 4915 return; 4916 } 4917 4918 if (msg_type == NetMsgType::NOTFOUND) { 4919 std::vector<CInv> vInv; 4920 vRecv >> vInv; 4921 std::vector<GenTxid> tx_invs; 4922 if (vInv.size() <= node::MAX_PEER_TX_ANNOUNCEMENTS + MAX_BLOCKS_IN_TRANSIT_PER_PEER) { 4923 for (CInv &inv : vInv) { 4924 if (inv.IsGenTxMsg()) { 4925 tx_invs.emplace_back(ToGenTxid(inv)); 4926 } 4927 } 4928 } 4929 LOCK(m_tx_download_mutex); 4930 m_txdownloadman.ReceivedNotFound(pfrom.GetId(), tx_invs); 4931 return; 4932 } 4933 4934 // Ignore unknown commands for extensibility 4935 LogDebug(BCLog::NET, "Unknown command \"%s\" from peer=%d\n", SanitizeString(msg_type), pfrom.GetId()); 4936 return; 4937 } 4938 4939 bool PeerManagerImpl::MaybeDiscourageAndDisconnect(CNode& pnode, Peer& peer) 4940 { 4941 { 4942 LOCK(peer.m_misbehavior_mutex); 4943 4944 // There's nothing to do if the m_should_discourage flag isn't set 4945 if (!peer.m_should_discourage) return false; 4946 4947 peer.m_should_discourage = false; 4948 } // peer.m_misbehavior_mutex 4949 4950 if (pnode.HasPermission(NetPermissionFlags::NoBan)) { 4951 // We never disconnect or discourage peers for bad behavior if they have NetPermissionFlags::NoBan permission 4952 LogWarning("Not punishing noban peer %d!", peer.m_id); 4953 return false; 4954 } 4955 4956 if (pnode.IsManualConn()) { 4957 // We never disconnect or discourage manual peers for bad behavior 4958 LogWarning("Not punishing manually connected peer %d!", peer.m_id); 4959 return false; 4960 } 4961 4962 if (pnode.addr.IsLocal()) { 4963 // We disconnect local peers for bad behavior but don't discourage (since that would discourage 4964 // all peers on the same local address) 4965 LogDebug(BCLog::NET, "Warning: disconnecting but not discouraging %s peer %d!\n", 4966 pnode.m_inbound_onion ? "inbound onion" : "local", peer.m_id); 4967 pnode.fDisconnect = true; 4968 return true; 4969 } 4970 4971 // Normal case: Disconnect the peer and discourage all nodes sharing the address 4972 LogDebug(BCLog::NET, "Disconnecting and discouraging peer %d!\n", peer.m_id); 4973 if (m_banman) m_banman->Discourage(pnode.addr); 4974 m_connman.DisconnectNode(pnode.addr); 4975 return true; 4976 } 4977 4978 bool PeerManagerImpl::ProcessMessages(CNode* pfrom, std::atomic<bool>& interruptMsgProc) 4979 { 4980 AssertLockNotHeld(m_tx_download_mutex); 4981 AssertLockHeld(g_msgproc_mutex); 4982 4983 PeerRef peer = GetPeerRef(pfrom->GetId()); 4984 if (peer == nullptr) return false; 4985 4986 // For outbound connections, ensure that the initial VERSION message 4987 // has been sent first before processing any incoming messages 4988 if (!pfrom->IsInboundConn() && !peer->m_outbound_version_message_sent) return false; 4989 4990 { 4991 LOCK(peer->m_getdata_requests_mutex); 4992 if (!peer->m_getdata_requests.empty()) { 4993 ProcessGetData(*pfrom, *peer, interruptMsgProc); 4994 } 4995 } 4996 4997 const bool processed_orphan = ProcessOrphanTx(*peer); 4998 4999 if (pfrom->fDisconnect) 5000 return false; 5001 5002 if (processed_orphan) return true; 5003 5004 // this maintains the order of responses 5005 // and prevents m_getdata_requests to grow unbounded 5006 { 5007 LOCK(peer->m_getdata_requests_mutex); 5008 if (!peer->m_getdata_requests.empty()) return true; 5009 } 5010 5011 // Don't bother if send buffer is too full to respond anyway 5012 if (pfrom->fPauseSend) return false; 5013 5014 auto poll_result{pfrom->PollMessage()}; 5015 if (!poll_result) { 5016 // No message to process 5017 return false; 5018 } 5019 5020 CNetMessage& msg{poll_result->first}; 5021 bool fMoreWork = poll_result->second; 5022 5023 TRACEPOINT(net, inbound_message, 5024 pfrom->GetId(), 5025 pfrom->m_addr_name.c_str(), 5026 pfrom->ConnectionTypeAsString().c_str(), 5027 msg.m_type.c_str(), 5028 msg.m_recv.size(), 5029 msg.m_recv.data() 5030 ); 5031 5032 if (m_opts.capture_messages) { 5033 CaptureMessage(pfrom->addr, msg.m_type, MakeUCharSpan(msg.m_recv), /*is_incoming=*/true); 5034 } 5035 5036 try { 5037 ProcessMessage(*pfrom, msg.m_type, msg.m_recv, msg.m_time, interruptMsgProc); 5038 if (interruptMsgProc) return false; 5039 { 5040 LOCK(peer->m_getdata_requests_mutex); 5041 if (!peer->m_getdata_requests.empty()) fMoreWork = true; 5042 } 5043 // Does this peer has an orphan ready to reconsider? 5044 // (Note: we may have provided a parent for an orphan provided 5045 // by another peer that was already processed; in that case, 5046 // the extra work may not be noticed, possibly resulting in an 5047 // unnecessary 100ms delay) 5048 LOCK(m_tx_download_mutex); 5049 if (m_txdownloadman.HaveMoreWork(peer->m_id)) fMoreWork = true; 5050 } catch (const std::exception& e) { 5051 LogDebug(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()); 5052 } catch (...) { 5053 LogDebug(BCLog::NET, "%s(%s, %u bytes): Unknown exception caught\n", __func__, SanitizeString(msg.m_type), msg.m_message_size); 5054 } 5055 5056 return fMoreWork; 5057 } 5058 5059 void PeerManagerImpl::ConsiderEviction(CNode& pto, Peer& peer, std::chrono::seconds time_in_seconds) 5060 { 5061 AssertLockHeld(cs_main); 5062 5063 CNodeState &state = *State(pto.GetId()); 5064 5065 if (!state.m_chain_sync.m_protect && pto.IsOutboundOrBlockRelayConn() && state.fSyncStarted) { 5066 // This is an outbound peer subject to disconnection if they don't 5067 // announce a block with as much work as the current tip within 5068 // CHAIN_SYNC_TIMEOUT + HEADERS_RESPONSE_TIME seconds (note: if 5069 // their chain has more work than ours, we should sync to it, 5070 // unless it's invalid, in which case we should find that out and 5071 // disconnect from them elsewhere). 5072 if (state.pindexBestKnownBlock != nullptr && state.pindexBestKnownBlock->nChainWork >= m_chainman.ActiveChain().Tip()->nChainWork) { 5073 // The outbound peer has sent us a block with at least as much work as our current tip, so reset the timeout if it was set 5074 if (state.m_chain_sync.m_timeout != 0s) { 5075 state.m_chain_sync.m_timeout = 0s; 5076 state.m_chain_sync.m_work_header = nullptr; 5077 state.m_chain_sync.m_sent_getheaders = false; 5078 } 5079 } 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)) { 5080 // At this point we know that the outbound peer has either never sent us a block/header or they have, but its tip is behind ours 5081 // AND 5082 // we are noticing this for the first time (m_timeout is 0) 5083 // OR we noticed this at some point within the last CHAIN_SYNC_TIMEOUT + HEADERS_RESPONSE_TIME seconds and set a timeout 5084 // for them, they caught up to our tip at the time of setting the timer but not to our current one (we've also advanced). 5085 // Either way, set a new timeout based on our current tip. 5086 state.m_chain_sync.m_timeout = time_in_seconds + CHAIN_SYNC_TIMEOUT; 5087 state.m_chain_sync.m_work_header = m_chainman.ActiveChain().Tip(); 5088 state.m_chain_sync.m_sent_getheaders = false; 5089 } else if (state.m_chain_sync.m_timeout > 0s && time_in_seconds > state.m_chain_sync.m_timeout) { 5090 // No evidence yet that our peer has synced to a chain with work equal to that 5091 // of our tip, when we first detected it was behind. Send a single getheaders 5092 // message to give the peer a chance to update us. 5093 if (state.m_chain_sync.m_sent_getheaders) { 5094 // They've run out of time to catch up! 5095 LogInfo("Outbound peer has old chain, best known block = %s, %s\n", state.pindexBestKnownBlock != nullptr ? state.pindexBestKnownBlock->GetBlockHash().ToString() : "<none>", pto.DisconnectMsg(fLogIPs)); 5096 pto.fDisconnect = true; 5097 } else { 5098 assert(state.m_chain_sync.m_work_header); 5099 // Here, we assume that the getheaders message goes out, 5100 // because it'll either go out or be skipped because of a 5101 // getheaders in-flight already, in which case the peer should 5102 // still respond to us with a sufficiently high work chain tip. 5103 MaybeSendGetHeaders(pto, 5104 GetLocator(state.m_chain_sync.m_work_header->pprev), 5105 peer); 5106 LogDebug(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()); 5107 state.m_chain_sync.m_sent_getheaders = true; 5108 // Bump the timeout to allow a response, which could clear the timeout 5109 // (if the response shows the peer has synced), reset the timeout (if 5110 // the peer syncs to the required work but not to our tip), or result 5111 // in disconnect (if we advance to the timeout and pindexBestKnownBlock 5112 // has not sufficiently progressed) 5113 state.m_chain_sync.m_timeout = time_in_seconds + HEADERS_RESPONSE_TIME; 5114 } 5115 } 5116 } 5117 } 5118 5119 void PeerManagerImpl::EvictExtraOutboundPeers(std::chrono::seconds now) 5120 { 5121 // If we have any extra block-relay-only peers, disconnect the youngest unless 5122 // it's given us a block -- in which case, compare with the second-youngest, and 5123 // out of those two, disconnect the peer who least recently gave us a block. 5124 // The youngest block-relay-only peer would be the extra peer we connected 5125 // to temporarily in order to sync our tip; see net.cpp. 5126 // Note that we use higher nodeid as a measure for most recent connection. 5127 if (m_connman.GetExtraBlockRelayCount() > 0) { 5128 std::pair<NodeId, std::chrono::seconds> youngest_peer{-1, 0}, next_youngest_peer{-1, 0}; 5129 5130 m_connman.ForEachNode([&](CNode* pnode) { 5131 if (!pnode->IsBlockOnlyConn() || pnode->fDisconnect) return; 5132 if (pnode->GetId() > youngest_peer.first) { 5133 next_youngest_peer = youngest_peer; 5134 youngest_peer.first = pnode->GetId(); 5135 youngest_peer.second = pnode->m_last_block_time; 5136 } 5137 }); 5138 NodeId to_disconnect = youngest_peer.first; 5139 if (youngest_peer.second > next_youngest_peer.second) { 5140 // Our newest block-relay-only peer gave us a block more recently; 5141 // disconnect our second youngest. 5142 to_disconnect = next_youngest_peer.first; 5143 } 5144 m_connman.ForNode(to_disconnect, [&](CNode* pnode) EXCLUSIVE_LOCKS_REQUIRED(::cs_main) { 5145 AssertLockHeld(::cs_main); 5146 // Make sure we're not getting a block right now, and that 5147 // we've been connected long enough for this eviction to happen 5148 // at all. 5149 // Note that we only request blocks from a peer if we learn of a 5150 // valid headers chain with at least as much work as our tip. 5151 CNodeState *node_state = State(pnode->GetId()); 5152 if (node_state == nullptr || 5153 (now - pnode->m_connected >= MINIMUM_CONNECT_TIME && node_state->vBlocksInFlight.empty())) { 5154 pnode->fDisconnect = true; 5155 LogDebug(BCLog::NET, "disconnecting extra block-relay-only peer=%d (last block received at time %d)\n", 5156 pnode->GetId(), count_seconds(pnode->m_last_block_time)); 5157 return true; 5158 } else { 5159 LogDebug(BCLog::NET, "keeping block-relay-only peer=%d chosen for eviction (connect time: %d, blocks_in_flight: %d)\n", 5160 pnode->GetId(), count_seconds(pnode->m_connected), node_state->vBlocksInFlight.size()); 5161 } 5162 return false; 5163 }); 5164 } 5165 5166 // Check whether we have too many outbound-full-relay peers 5167 if (m_connman.GetExtraFullOutboundCount() > 0) { 5168 // If we have more outbound-full-relay peers than we target, disconnect one. 5169 // Pick the outbound-full-relay peer that least recently announced 5170 // us a new block, with ties broken by choosing the more recent 5171 // connection (higher node id) 5172 // Protect peers from eviction if we don't have another connection 5173 // to their network, counting both outbound-full-relay and manual peers. 5174 NodeId worst_peer = -1; 5175 int64_t oldest_block_announcement = std::numeric_limits<int64_t>::max(); 5176 5177 m_connman.ForEachNode([&](CNode* pnode) EXCLUSIVE_LOCKS_REQUIRED(::cs_main, m_connman.GetNodesMutex()) { 5178 AssertLockHeld(::cs_main); 5179 5180 // Only consider outbound-full-relay peers that are not already 5181 // marked for disconnection 5182 if (!pnode->IsFullOutboundConn() || pnode->fDisconnect) return; 5183 CNodeState *state = State(pnode->GetId()); 5184 if (state == nullptr) return; // shouldn't be possible, but just in case 5185 // Don't evict our protected peers 5186 if (state->m_chain_sync.m_protect) return; 5187 // If this is the only connection on a particular network that is 5188 // OUTBOUND_FULL_RELAY or MANUAL, protect it. 5189 if (!m_connman.MultipleManualOrFullOutboundConns(pnode->addr.GetNetwork())) return; 5190 if (state->m_last_block_announcement < oldest_block_announcement || (state->m_last_block_announcement == oldest_block_announcement && pnode->GetId() > worst_peer)) { 5191 worst_peer = pnode->GetId(); 5192 oldest_block_announcement = state->m_last_block_announcement; 5193 } 5194 }); 5195 if (worst_peer != -1) { 5196 bool disconnected = m_connman.ForNode(worst_peer, [&](CNode* pnode) EXCLUSIVE_LOCKS_REQUIRED(::cs_main) { 5197 AssertLockHeld(::cs_main); 5198 5199 // Only disconnect a peer that has been connected to us for 5200 // some reasonable fraction of our check-frequency, to give 5201 // it time for new information to have arrived. 5202 // Also don't disconnect any peer we're trying to download a 5203 // block from. 5204 CNodeState &state = *State(pnode->GetId()); 5205 if (now - pnode->m_connected > MINIMUM_CONNECT_TIME && state.vBlocksInFlight.empty()) { 5206 LogDebug(BCLog::NET, "disconnecting extra outbound peer=%d (last block announcement received at time %d)\n", pnode->GetId(), oldest_block_announcement); 5207 pnode->fDisconnect = true; 5208 return true; 5209 } else { 5210 LogDebug(BCLog::NET, "keeping outbound peer=%d chosen for eviction (connect time: %d, blocks_in_flight: %d)\n", 5211 pnode->GetId(), count_seconds(pnode->m_connected), state.vBlocksInFlight.size()); 5212 return false; 5213 } 5214 }); 5215 if (disconnected) { 5216 // If we disconnected an extra peer, that means we successfully 5217 // connected to at least one peer after the last time we 5218 // detected a stale tip. Don't try any more extra peers until 5219 // we next detect a stale tip, to limit the load we put on the 5220 // network from these extra connections. 5221 m_connman.SetTryNewOutboundPeer(false); 5222 } 5223 } 5224 } 5225 } 5226 5227 void PeerManagerImpl::CheckForStaleTipAndEvictPeers() 5228 { 5229 LOCK(cs_main); 5230 5231 auto now{GetTime<std::chrono::seconds>()}; 5232 5233 EvictExtraOutboundPeers(now); 5234 5235 if (now > m_stale_tip_check_time) { 5236 // Check whether our tip is stale, and if so, allow using an extra 5237 // outbound peer 5238 if (!m_chainman.m_blockman.LoadingBlocks() && m_connman.GetNetworkActive() && m_connman.GetUseAddrmanOutgoing() && TipMayBeStale()) { 5239 LogPrintf("Potential stale tip detected, will try using extra outbound peer (last tip update: %d seconds ago)\n", 5240 count_seconds(now - m_last_tip_update.load())); 5241 m_connman.SetTryNewOutboundPeer(true); 5242 } else if (m_connman.GetTryNewOutboundPeer()) { 5243 m_connman.SetTryNewOutboundPeer(false); 5244 } 5245 m_stale_tip_check_time = now + STALE_CHECK_INTERVAL; 5246 } 5247 5248 if (!m_initial_sync_finished && CanDirectFetch()) { 5249 m_connman.StartExtraBlockRelayPeers(); 5250 m_initial_sync_finished = true; 5251 } 5252 } 5253 5254 void PeerManagerImpl::MaybeSendPing(CNode& node_to, Peer& peer, std::chrono::microseconds now) 5255 { 5256 if (m_connman.ShouldRunInactivityChecks(node_to, std::chrono::duration_cast<std::chrono::seconds>(now)) && 5257 peer.m_ping_nonce_sent && 5258 now > peer.m_ping_start.load() + TIMEOUT_INTERVAL) 5259 { 5260 // The ping timeout is using mocktime. To disable the check during 5261 // testing, increase -peertimeout. 5262 LogDebug(BCLog::NET, "ping timeout: %fs, %s", 0.000001 * count_microseconds(now - peer.m_ping_start.load()), node_to.DisconnectMsg(fLogIPs)); 5263 node_to.fDisconnect = true; 5264 return; 5265 } 5266 5267 bool pingSend = false; 5268 5269 if (peer.m_ping_queued) { 5270 // RPC ping request by user 5271 pingSend = true; 5272 } 5273 5274 if (peer.m_ping_nonce_sent == 0 && now > peer.m_ping_start.load() + PING_INTERVAL) { 5275 // Ping automatically sent as a latency probe & keepalive. 5276 pingSend = true; 5277 } 5278 5279 if (pingSend) { 5280 uint64_t nonce; 5281 do { 5282 nonce = FastRandomContext().rand64(); 5283 } while (nonce == 0); 5284 peer.m_ping_queued = false; 5285 peer.m_ping_start = now; 5286 if (node_to.GetCommonVersion() > BIP0031_VERSION) { 5287 peer.m_ping_nonce_sent = nonce; 5288 MakeAndPushMessage(node_to, NetMsgType::PING, nonce); 5289 } else { 5290 // Peer is too old to support ping command with nonce, pong will never arrive. 5291 peer.m_ping_nonce_sent = 0; 5292 MakeAndPushMessage(node_to, NetMsgType::PING); 5293 } 5294 } 5295 } 5296 5297 void PeerManagerImpl::MaybeSendAddr(CNode& node, Peer& peer, std::chrono::microseconds current_time) 5298 { 5299 // Nothing to do for non-address-relay peers 5300 if (!peer.m_addr_relay_enabled) return; 5301 5302 LOCK(peer.m_addr_send_times_mutex); 5303 // Periodically advertise our local address to the peer. 5304 if (fListen && !m_chainman.IsInitialBlockDownload() && 5305 peer.m_next_local_addr_send < current_time) { 5306 // If we've sent before, clear the bloom filter for the peer, so that our 5307 // self-announcement will actually go out. 5308 // This might be unnecessary if the bloom filter has already rolled 5309 // over since our last self-announcement, but there is only a small 5310 // bandwidth cost that we can incur by doing this (which happens 5311 // once a day on average). 5312 if (peer.m_next_local_addr_send != 0us) { 5313 peer.m_addr_known->reset(); 5314 } 5315 if (std::optional<CService> local_service = GetLocalAddrForPeer(node)) { 5316 CAddress local_addr{*local_service, peer.m_our_services, Now<NodeSeconds>()}; 5317 PushAddress(peer, local_addr); 5318 } 5319 peer.m_next_local_addr_send = current_time + m_rng.rand_exp_duration(AVG_LOCAL_ADDRESS_BROADCAST_INTERVAL); 5320 } 5321 5322 // We sent an `addr` message to this peer recently. Nothing more to do. 5323 if (current_time <= peer.m_next_addr_send) return; 5324 5325 peer.m_next_addr_send = current_time + m_rng.rand_exp_duration(AVG_ADDRESS_BROADCAST_INTERVAL); 5326 5327 if (!Assume(peer.m_addrs_to_send.size() <= MAX_ADDR_TO_SEND)) { 5328 // Should be impossible since we always check size before adding to 5329 // m_addrs_to_send. Recover by trimming the vector. 5330 peer.m_addrs_to_send.resize(MAX_ADDR_TO_SEND); 5331 } 5332 5333 // Remove addr records that the peer already knows about, and add new 5334 // addrs to the m_addr_known filter on the same pass. 5335 auto addr_already_known = [&peer](const CAddress& addr) EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex) { 5336 bool ret = peer.m_addr_known->contains(addr.GetKey()); 5337 if (!ret) peer.m_addr_known->insert(addr.GetKey()); 5338 return ret; 5339 }; 5340 peer.m_addrs_to_send.erase(std::remove_if(peer.m_addrs_to_send.begin(), peer.m_addrs_to_send.end(), addr_already_known), 5341 peer.m_addrs_to_send.end()); 5342 5343 // No addr messages to send 5344 if (peer.m_addrs_to_send.empty()) return; 5345 5346 if (peer.m_wants_addrv2) { 5347 MakeAndPushMessage(node, NetMsgType::ADDRV2, CAddress::V2_NETWORK(peer.m_addrs_to_send)); 5348 } else { 5349 MakeAndPushMessage(node, NetMsgType::ADDR, CAddress::V1_NETWORK(peer.m_addrs_to_send)); 5350 } 5351 peer.m_addrs_to_send.clear(); 5352 5353 // we only send the big addr message once 5354 if (peer.m_addrs_to_send.capacity() > 40) { 5355 peer.m_addrs_to_send.shrink_to_fit(); 5356 } 5357 } 5358 5359 void PeerManagerImpl::MaybeSendSendHeaders(CNode& node, Peer& peer) 5360 { 5361 // Delay sending SENDHEADERS (BIP 130) until we're done with an 5362 // initial-headers-sync with this peer. Receiving headers announcements for 5363 // new blocks while trying to sync their headers chain is problematic, 5364 // because of the state tracking done. 5365 if (!peer.m_sent_sendheaders && node.GetCommonVersion() >= SENDHEADERS_VERSION) { 5366 LOCK(cs_main); 5367 CNodeState &state = *State(node.GetId()); 5368 if (state.pindexBestKnownBlock != nullptr && 5369 state.pindexBestKnownBlock->nChainWork > m_chainman.MinimumChainWork()) { 5370 // Tell our peer we prefer to receive headers rather than inv's 5371 // We send this to non-NODE NETWORK peers as well, because even 5372 // non-NODE NETWORK peers can announce blocks (such as pruning 5373 // nodes) 5374 MakeAndPushMessage(node, NetMsgType::SENDHEADERS); 5375 peer.m_sent_sendheaders = true; 5376 } 5377 } 5378 } 5379 5380 void PeerManagerImpl::MaybeSendFeefilter(CNode& pto, Peer& peer, std::chrono::microseconds current_time) 5381 { 5382 if (m_opts.ignore_incoming_txs) return; 5383 if (pto.GetCommonVersion() < FEEFILTER_VERSION) return; 5384 // peers with the forcerelay permission should not filter txs to us 5385 if (pto.HasPermission(NetPermissionFlags::ForceRelay)) return; 5386 // Don't send feefilter messages to outbound block-relay-only peers since they should never announce 5387 // transactions to us, regardless of feefilter state. 5388 if (pto.IsBlockOnlyConn()) return; 5389 5390 CAmount currentFilter = m_mempool.GetMinFee().GetFeePerK(); 5391 5392 if (m_chainman.IsInitialBlockDownload()) { 5393 // Received tx-inv messages are discarded when the active 5394 // chainstate is in IBD, so tell the peer to not send them. 5395 currentFilter = MAX_MONEY; 5396 } else { 5397 static const CAmount MAX_FILTER{m_fee_filter_rounder.round(MAX_MONEY)}; 5398 if (peer.m_fee_filter_sent == MAX_FILTER) { 5399 // Send the current filter if we sent MAX_FILTER previously 5400 // and made it out of IBD. 5401 peer.m_next_send_feefilter = 0us; 5402 } 5403 } 5404 if (current_time > peer.m_next_send_feefilter) { 5405 CAmount filterToSend = m_fee_filter_rounder.round(currentFilter); 5406 // We always have a fee filter of at least the min relay fee 5407 filterToSend = std::max(filterToSend, m_mempool.m_opts.min_relay_feerate.GetFeePerK()); 5408 if (filterToSend != peer.m_fee_filter_sent) { 5409 MakeAndPushMessage(pto, NetMsgType::FEEFILTER, filterToSend); 5410 peer.m_fee_filter_sent = filterToSend; 5411 } 5412 peer.m_next_send_feefilter = current_time + m_rng.rand_exp_duration(AVG_FEEFILTER_BROADCAST_INTERVAL); 5413 } 5414 // If the fee filter has changed substantially and it's still more than MAX_FEEFILTER_CHANGE_DELAY 5415 // until scheduled broadcast, then move the broadcast to within MAX_FEEFILTER_CHANGE_DELAY. 5416 else if (current_time + MAX_FEEFILTER_CHANGE_DELAY < peer.m_next_send_feefilter && 5417 (currentFilter < 3 * peer.m_fee_filter_sent / 4 || currentFilter > 4 * peer.m_fee_filter_sent / 3)) { 5418 peer.m_next_send_feefilter = current_time + m_rng.randrange<std::chrono::microseconds>(MAX_FEEFILTER_CHANGE_DELAY); 5419 } 5420 } 5421 5422 namespace { 5423 class CompareInvMempoolOrder 5424 { 5425 const CTxMemPool* m_mempool; 5426 public: 5427 explicit CompareInvMempoolOrder(CTxMemPool* mempool) : m_mempool{mempool} {} 5428 5429 bool operator()(std::set<Wtxid>::iterator a, std::set<Wtxid>::iterator b) 5430 { 5431 /* As std::make_heap produces a max-heap, we want the entries with the 5432 * higher mining score to sort later. */ 5433 return m_mempool->CompareMiningScoreWithTopology(*b, *a); 5434 } 5435 }; 5436 } // namespace 5437 5438 bool PeerManagerImpl::RejectIncomingTxs(const CNode& peer) const 5439 { 5440 // block-relay-only peers may never send txs to us 5441 if (peer.IsBlockOnlyConn()) return true; 5442 if (peer.IsFeelerConn()) return true; 5443 // In -blocksonly mode, peers need the 'relay' permission to send txs to us 5444 if (m_opts.ignore_incoming_txs && !peer.HasPermission(NetPermissionFlags::Relay)) return true; 5445 return false; 5446 } 5447 5448 bool PeerManagerImpl::SetupAddressRelay(const CNode& node, Peer& peer) 5449 { 5450 // We don't participate in addr relay with outbound block-relay-only 5451 // connections to prevent providing adversaries with the additional 5452 // information of addr traffic to infer the link. 5453 if (node.IsBlockOnlyConn()) return false; 5454 5455 if (!peer.m_addr_relay_enabled.exchange(true)) { 5456 // During version message processing (non-block-relay-only outbound peers) 5457 // or on first addr-related message we have received (inbound peers), initialize 5458 // m_addr_known. 5459 peer.m_addr_known = std::make_unique<CRollingBloomFilter>(5000, 0.001); 5460 } 5461 5462 return true; 5463 } 5464 5465 bool PeerManagerImpl::SendMessages(CNode* pto) 5466 { 5467 AssertLockNotHeld(m_tx_download_mutex); 5468 AssertLockHeld(g_msgproc_mutex); 5469 5470 PeerRef peer = GetPeerRef(pto->GetId()); 5471 if (!peer) return false; 5472 const Consensus::Params& consensusParams = m_chainparams.GetConsensus(); 5473 5474 // We must call MaybeDiscourageAndDisconnect first, to ensure that we'll 5475 // disconnect misbehaving peers even before the version handshake is complete. 5476 if (MaybeDiscourageAndDisconnect(*pto, *peer)) return true; 5477 5478 // Initiate version handshake for outbound connections 5479 if (!pto->IsInboundConn() && !peer->m_outbound_version_message_sent) { 5480 PushNodeVersion(*pto, *peer); 5481 peer->m_outbound_version_message_sent = true; 5482 } 5483 5484 // Don't send anything until the version handshake is complete 5485 if (!pto->fSuccessfullyConnected || pto->fDisconnect) 5486 return true; 5487 5488 const auto current_time{GetTime<std::chrono::microseconds>()}; 5489 5490 if (pto->IsAddrFetchConn() && current_time - pto->m_connected > 10 * AVG_ADDRESS_BROADCAST_INTERVAL) { 5491 LogDebug(BCLog::NET, "addrfetch connection timeout, %s\n", pto->DisconnectMsg(fLogIPs)); 5492 pto->fDisconnect = true; 5493 return true; 5494 } 5495 5496 MaybeSendPing(*pto, *peer, current_time); 5497 5498 // MaybeSendPing may have marked peer for disconnection 5499 if (pto->fDisconnect) return true; 5500 5501 MaybeSendAddr(*pto, *peer, current_time); 5502 5503 MaybeSendSendHeaders(*pto, *peer); 5504 5505 { 5506 LOCK(cs_main); 5507 5508 CNodeState &state = *State(pto->GetId()); 5509 5510 // Start block sync 5511 if (m_chainman.m_best_header == nullptr) { 5512 m_chainman.m_best_header = m_chainman.ActiveChain().Tip(); 5513 } 5514 5515 // Determine whether we might try initial headers sync or parallel 5516 // block download from this peer -- this mostly affects behavior while 5517 // in IBD (once out of IBD, we sync from all peers). 5518 bool sync_blocks_and_headers_from_peer = false; 5519 if (state.fPreferredDownload) { 5520 sync_blocks_and_headers_from_peer = true; 5521 } else if (CanServeBlocks(*peer) && !pto->IsAddrFetchConn()) { 5522 // Typically this is an inbound peer. If we don't have any outbound 5523 // peers, or if we aren't downloading any blocks from such peers, 5524 // then allow block downloads from this peer, too. 5525 // We prefer downloading blocks from outbound peers to avoid 5526 // putting undue load on (say) some home user who is just making 5527 // outbound connections to the network, but if our only source of 5528 // the latest blocks is from an inbound peer, we have to be sure to 5529 // eventually download it (and not just wait indefinitely for an 5530 // outbound peer to have it). 5531 if (m_num_preferred_download_peers == 0 || mapBlocksInFlight.empty()) { 5532 sync_blocks_and_headers_from_peer = true; 5533 } 5534 } 5535 5536 if (!state.fSyncStarted && CanServeBlocks(*peer) && !m_chainman.m_blockman.LoadingBlocks()) { 5537 // Only actively request headers from a single peer, unless we're close to today. 5538 if ((nSyncStarted == 0 && sync_blocks_and_headers_from_peer) || m_chainman.m_best_header->Time() > NodeClock::now() - 24h) { 5539 const CBlockIndex* pindexStart = m_chainman.m_best_header; 5540 /* If possible, start at the block preceding the currently 5541 best known header. This ensures that we always get a 5542 non-empty list of headers back as long as the peer 5543 is up-to-date. With a non-empty response, we can initialise 5544 the peer's known best block. This wouldn't be possible 5545 if we requested starting at m_chainman.m_best_header and 5546 got back an empty response. */ 5547 if (pindexStart->pprev) 5548 pindexStart = pindexStart->pprev; 5549 if (MaybeSendGetHeaders(*pto, GetLocator(pindexStart), *peer)) { 5550 LogDebug(BCLog::NET, "initial getheaders (%d) to peer=%d (startheight:%d)\n", pindexStart->nHeight, pto->GetId(), peer->m_starting_height); 5551 5552 state.fSyncStarted = true; 5553 peer->m_headers_sync_timeout = current_time + HEADERS_DOWNLOAD_TIMEOUT_BASE + 5554 ( 5555 // Convert HEADERS_DOWNLOAD_TIMEOUT_PER_HEADER to microseconds before scaling 5556 // to maintain precision 5557 std::chrono::microseconds{HEADERS_DOWNLOAD_TIMEOUT_PER_HEADER} * 5558 Ticks<std::chrono::seconds>(NodeClock::now() - m_chainman.m_best_header->Time()) / consensusParams.nPowTargetSpacing 5559 ); 5560 nSyncStarted++; 5561 } 5562 } 5563 } 5564 5565 // 5566 // Try sending block announcements via headers 5567 // 5568 { 5569 // If we have no more than MAX_BLOCKS_TO_ANNOUNCE in our 5570 // list of block hashes we're relaying, and our peer wants 5571 // headers announcements, then find the first header 5572 // not yet known to our peer but would connect, and send. 5573 // If no header would connect, or if we have too many 5574 // blocks, or if the peer doesn't want headers, just 5575 // add all to the inv queue. 5576 LOCK(peer->m_block_inv_mutex); 5577 std::vector<CBlock> vHeaders; 5578 bool fRevertToInv = ((!peer->m_prefers_headers && 5579 (!state.m_requested_hb_cmpctblocks || peer->m_blocks_for_headers_relay.size() > 1)) || 5580 peer->m_blocks_for_headers_relay.size() > MAX_BLOCKS_TO_ANNOUNCE); 5581 const CBlockIndex *pBestIndex = nullptr; // last header queued for delivery 5582 ProcessBlockAvailability(pto->GetId()); // ensure pindexBestKnownBlock is up-to-date 5583 5584 if (!fRevertToInv) { 5585 bool fFoundStartingHeader = false; 5586 // Try to find first header that our peer doesn't have, and 5587 // then send all headers past that one. If we come across any 5588 // headers that aren't on m_chainman.ActiveChain(), give up. 5589 for (const uint256& hash : peer->m_blocks_for_headers_relay) { 5590 const CBlockIndex* pindex = m_chainman.m_blockman.LookupBlockIndex(hash); 5591 assert(pindex); 5592 if (m_chainman.ActiveChain()[pindex->nHeight] != pindex) { 5593 // Bail out if we reorged away from this block 5594 fRevertToInv = true; 5595 break; 5596 } 5597 if (pBestIndex != nullptr && pindex->pprev != pBestIndex) { 5598 // This means that the list of blocks to announce don't 5599 // connect to each other. 5600 // This shouldn't really be possible to hit during 5601 // regular operation (because reorgs should take us to 5602 // a chain that has some block not on the prior chain, 5603 // which should be caught by the prior check), but one 5604 // way this could happen is by using invalidateblock / 5605 // reconsiderblock repeatedly on the tip, causing it to 5606 // be added multiple times to m_blocks_for_headers_relay. 5607 // Robustly deal with this rare situation by reverting 5608 // to an inv. 5609 fRevertToInv = true; 5610 break; 5611 } 5612 pBestIndex = pindex; 5613 if (fFoundStartingHeader) { 5614 // add this to the headers message 5615 vHeaders.emplace_back(pindex->GetBlockHeader()); 5616 } else if (PeerHasHeader(&state, pindex)) { 5617 continue; // keep looking for the first new block 5618 } else if (pindex->pprev == nullptr || PeerHasHeader(&state, pindex->pprev)) { 5619 // Peer doesn't have this header but they do have the prior one. 5620 // Start sending headers. 5621 fFoundStartingHeader = true; 5622 vHeaders.emplace_back(pindex->GetBlockHeader()); 5623 } else { 5624 // Peer doesn't have this header or the prior one -- nothing will 5625 // connect, so bail out. 5626 fRevertToInv = true; 5627 break; 5628 } 5629 } 5630 } 5631 if (!fRevertToInv && !vHeaders.empty()) { 5632 if (vHeaders.size() == 1 && state.m_requested_hb_cmpctblocks) { 5633 // We only send up to 1 block as header-and-ids, as otherwise 5634 // probably means we're doing an initial-ish-sync or they're slow 5635 LogDebug(BCLog::NET, "%s sending header-and-ids %s to peer=%d\n", __func__, 5636 vHeaders.front().GetHash().ToString(), pto->GetId()); 5637 5638 std::optional<CSerializedNetMsg> cached_cmpctblock_msg; 5639 { 5640 LOCK(m_most_recent_block_mutex); 5641 if (m_most_recent_block_hash == pBestIndex->GetBlockHash()) { 5642 cached_cmpctblock_msg = NetMsg::Make(NetMsgType::CMPCTBLOCK, *m_most_recent_compact_block); 5643 } 5644 } 5645 if (cached_cmpctblock_msg.has_value()) { 5646 PushMessage(*pto, std::move(cached_cmpctblock_msg.value())); 5647 } else { 5648 CBlock block; 5649 const bool ret{m_chainman.m_blockman.ReadBlock(block, *pBestIndex)}; 5650 assert(ret); 5651 CBlockHeaderAndShortTxIDs cmpctblock{block, m_rng.rand64()}; 5652 MakeAndPushMessage(*pto, NetMsgType::CMPCTBLOCK, cmpctblock); 5653 } 5654 state.pindexBestHeaderSent = pBestIndex; 5655 } else if (peer->m_prefers_headers) { 5656 if (vHeaders.size() > 1) { 5657 LogDebug(BCLog::NET, "%s: %u headers, range (%s, %s), to peer=%d\n", __func__, 5658 vHeaders.size(), 5659 vHeaders.front().GetHash().ToString(), 5660 vHeaders.back().GetHash().ToString(), pto->GetId()); 5661 } else { 5662 LogDebug(BCLog::NET, "%s: sending header %s to peer=%d\n", __func__, 5663 vHeaders.front().GetHash().ToString(), pto->GetId()); 5664 } 5665 MakeAndPushMessage(*pto, NetMsgType::HEADERS, TX_WITH_WITNESS(vHeaders)); 5666 state.pindexBestHeaderSent = pBestIndex; 5667 } else 5668 fRevertToInv = true; 5669 } 5670 if (fRevertToInv) { 5671 // If falling back to using an inv, just try to inv the tip. 5672 // The last entry in m_blocks_for_headers_relay was our tip at some point 5673 // in the past. 5674 if (!peer->m_blocks_for_headers_relay.empty()) { 5675 const uint256& hashToAnnounce = peer->m_blocks_for_headers_relay.back(); 5676 const CBlockIndex* pindex = m_chainman.m_blockman.LookupBlockIndex(hashToAnnounce); 5677 assert(pindex); 5678 5679 // Warn if we're announcing a block that is not on the main chain. 5680 // This should be very rare and could be optimized out. 5681 // Just log for now. 5682 if (m_chainman.ActiveChain()[pindex->nHeight] != pindex) { 5683 LogDebug(BCLog::NET, "Announcing block %s not on main chain (tip=%s)\n", 5684 hashToAnnounce.ToString(), m_chainman.ActiveChain().Tip()->GetBlockHash().ToString()); 5685 } 5686 5687 // If the peer's chain has this block, don't inv it back. 5688 if (!PeerHasHeader(&state, pindex)) { 5689 peer->m_blocks_for_inv_relay.push_back(hashToAnnounce); 5690 LogDebug(BCLog::NET, "%s: sending inv peer=%d hash=%s\n", __func__, 5691 pto->GetId(), hashToAnnounce.ToString()); 5692 } 5693 } 5694 } 5695 peer->m_blocks_for_headers_relay.clear(); 5696 } 5697 5698 // 5699 // Message: inventory 5700 // 5701 std::vector<CInv> vInv; 5702 { 5703 LOCK(peer->m_block_inv_mutex); 5704 vInv.reserve(std::max<size_t>(peer->m_blocks_for_inv_relay.size(), INVENTORY_BROADCAST_TARGET)); 5705 5706 // Add blocks 5707 for (const uint256& hash : peer->m_blocks_for_inv_relay) { 5708 vInv.emplace_back(MSG_BLOCK, hash); 5709 if (vInv.size() == MAX_INV_SZ) { 5710 MakeAndPushMessage(*pto, NetMsgType::INV, vInv); 5711 vInv.clear(); 5712 } 5713 } 5714 peer->m_blocks_for_inv_relay.clear(); 5715 } 5716 5717 if (auto tx_relay = peer->GetTxRelay(); tx_relay != nullptr) { 5718 LOCK(tx_relay->m_tx_inventory_mutex); 5719 // Check whether periodic sends should happen 5720 bool fSendTrickle = pto->HasPermission(NetPermissionFlags::NoBan); 5721 if (tx_relay->m_next_inv_send_time < current_time) { 5722 fSendTrickle = true; 5723 if (pto->IsInboundConn()) { 5724 tx_relay->m_next_inv_send_time = NextInvToInbounds(current_time, INBOUND_INVENTORY_BROADCAST_INTERVAL, pto->m_network_key); 5725 } else { 5726 tx_relay->m_next_inv_send_time = current_time + m_rng.rand_exp_duration(OUTBOUND_INVENTORY_BROADCAST_INTERVAL); 5727 } 5728 } 5729 5730 // Time to send but the peer has requested we not relay transactions. 5731 if (fSendTrickle) { 5732 LOCK(tx_relay->m_bloom_filter_mutex); 5733 if (!tx_relay->m_relay_txs) tx_relay->m_tx_inventory_to_send.clear(); 5734 } 5735 5736 // Respond to BIP35 mempool requests 5737 if (fSendTrickle && tx_relay->m_send_mempool) { 5738 auto vtxinfo = m_mempool.infoAll(); 5739 tx_relay->m_send_mempool = false; 5740 const CFeeRate filterrate{tx_relay->m_fee_filter_received.load()}; 5741 5742 LOCK(tx_relay->m_bloom_filter_mutex); 5743 5744 for (const auto& txinfo : vtxinfo) { 5745 const Txid& txid{txinfo.tx->GetHash()}; 5746 const Wtxid& wtxid{txinfo.tx->GetWitnessHash()}; 5747 const auto inv = peer->m_wtxid_relay ? 5748 CInv{MSG_WTX, wtxid.ToUint256()} : 5749 CInv{MSG_TX, txid.ToUint256()}; 5750 tx_relay->m_tx_inventory_to_send.erase(wtxid); 5751 5752 // Don't send transactions that peers will not put into their mempool 5753 if (txinfo.fee < filterrate.GetFee(txinfo.vsize)) { 5754 continue; 5755 } 5756 if (tx_relay->m_bloom_filter) { 5757 if (!tx_relay->m_bloom_filter->IsRelevantAndUpdate(*txinfo.tx)) continue; 5758 } 5759 tx_relay->m_tx_inventory_known_filter.insert(inv.hash); 5760 vInv.push_back(inv); 5761 if (vInv.size() == MAX_INV_SZ) { 5762 MakeAndPushMessage(*pto, NetMsgType::INV, vInv); 5763 vInv.clear(); 5764 } 5765 } 5766 } 5767 5768 // Determine transactions to relay 5769 if (fSendTrickle) { 5770 // Produce a vector with all candidates for sending 5771 std::vector<std::set<Wtxid>::iterator> vInvTx; 5772 vInvTx.reserve(tx_relay->m_tx_inventory_to_send.size()); 5773 for (std::set<Wtxid>::iterator it = tx_relay->m_tx_inventory_to_send.begin(); it != tx_relay->m_tx_inventory_to_send.end(); it++) { 5774 vInvTx.push_back(it); 5775 } 5776 const CFeeRate filterrate{tx_relay->m_fee_filter_received.load()}; 5777 // Topologically and fee-rate sort the inventory we send for privacy and priority reasons. 5778 // A heap is used so that not all items need sorting if only a few are being sent. 5779 CompareInvMempoolOrder compareInvMempoolOrder(&m_mempool); 5780 std::make_heap(vInvTx.begin(), vInvTx.end(), compareInvMempoolOrder); 5781 // No reason to drain out at many times the network's capacity, 5782 // especially since we have many peers and some will draw much shorter delays. 5783 unsigned int nRelayedTransactions = 0; 5784 LOCK(tx_relay->m_bloom_filter_mutex); 5785 size_t broadcast_max{INVENTORY_BROADCAST_TARGET + (tx_relay->m_tx_inventory_to_send.size()/1000)*5}; 5786 broadcast_max = std::min<size_t>(INVENTORY_BROADCAST_MAX, broadcast_max); 5787 while (!vInvTx.empty() && nRelayedTransactions < broadcast_max) { 5788 // Fetch the top element from the heap 5789 std::pop_heap(vInvTx.begin(), vInvTx.end(), compareInvMempoolOrder); 5790 std::set<Wtxid>::iterator it = vInvTx.back(); 5791 vInvTx.pop_back(); 5792 auto wtxid = *it; 5793 // Remove it from the to-be-sent set 5794 tx_relay->m_tx_inventory_to_send.erase(it); 5795 // Not in the mempool anymore? don't bother sending it. 5796 auto txinfo = m_mempool.info(wtxid); 5797 if (!txinfo.tx) { 5798 continue; 5799 } 5800 // `TxRelay::m_tx_inventory_known_filter` contains either txids or wtxids 5801 // depending on whether our peer supports wtxid-relay. Therefore, first 5802 // construct the inv and then use its hash for the filter check. 5803 const auto inv = peer->m_wtxid_relay ? 5804 CInv{MSG_WTX, wtxid.ToUint256()} : 5805 CInv{MSG_TX, txinfo.tx->GetHash().ToUint256()}; 5806 // Check if not in the filter already 5807 if (tx_relay->m_tx_inventory_known_filter.contains(inv.hash)) { 5808 continue; 5809 } 5810 // Peer told you to not send transactions at that feerate? Don't bother sending it. 5811 if (txinfo.fee < filterrate.GetFee(txinfo.vsize)) { 5812 continue; 5813 } 5814 if (tx_relay->m_bloom_filter && !tx_relay->m_bloom_filter->IsRelevantAndUpdate(*txinfo.tx)) continue; 5815 // Send 5816 vInv.push_back(inv); 5817 nRelayedTransactions++; 5818 if (vInv.size() == MAX_INV_SZ) { 5819 MakeAndPushMessage(*pto, NetMsgType::INV, vInv); 5820 vInv.clear(); 5821 } 5822 tx_relay->m_tx_inventory_known_filter.insert(inv.hash); 5823 } 5824 5825 // Ensure we'll respond to GETDATA requests for anything we've just announced 5826 LOCK(m_mempool.cs); 5827 tx_relay->m_last_inv_sequence = m_mempool.GetSequence(); 5828 } 5829 } 5830 if (!vInv.empty()) 5831 MakeAndPushMessage(*pto, NetMsgType::INV, vInv); 5832 5833 // Detect whether we're stalling 5834 auto stalling_timeout = m_block_stalling_timeout.load(); 5835 if (state.m_stalling_since.count() && state.m_stalling_since < current_time - stalling_timeout) { 5836 // Stalling only triggers when the block download window cannot move. During normal steady state, 5837 // the download window should be much larger than the to-be-downloaded set of blocks, so disconnection 5838 // should only happen during initial block download. 5839 LogInfo("Peer is stalling block download, %s\n", pto->DisconnectMsg(fLogIPs)); 5840 pto->fDisconnect = true; 5841 // Increase timeout for the next peer so that we don't disconnect multiple peers if our own 5842 // bandwidth is insufficient. 5843 const auto new_timeout = std::min(2 * stalling_timeout, BLOCK_STALLING_TIMEOUT_MAX); 5844 if (stalling_timeout != new_timeout && m_block_stalling_timeout.compare_exchange_strong(stalling_timeout, new_timeout)) { 5845 LogDebug(BCLog::NET, "Increased stalling timeout temporarily to %d seconds\n", count_seconds(new_timeout)); 5846 } 5847 return true; 5848 } 5849 // In case there is a block that has been in flight from this peer for block_interval * (1 + 0.5 * N) 5850 // (with N the number of peers from which we're downloading validated blocks), disconnect due to timeout. 5851 // We compensate for other peers to prevent killing off peers due to our own downstream link 5852 // being saturated. We only count validated in-flight blocks so peers can't advertise non-existing block hashes 5853 // to unreasonably increase our timeout. 5854 if (state.vBlocksInFlight.size() > 0) { 5855 QueuedBlock &queuedBlock = state.vBlocksInFlight.front(); 5856 int nOtherPeersWithValidatedDownloads = m_peers_downloading_from - 1; 5857 if (current_time > state.m_downloading_since + std::chrono::seconds{consensusParams.nPowTargetSpacing} * (BLOCK_DOWNLOAD_TIMEOUT_BASE + BLOCK_DOWNLOAD_TIMEOUT_PER_PEER * nOtherPeersWithValidatedDownloads)) { 5858 LogInfo("Timeout downloading block %s, %s\n", queuedBlock.pindex->GetBlockHash().ToString(), pto->DisconnectMsg(fLogIPs)); 5859 pto->fDisconnect = true; 5860 return true; 5861 } 5862 } 5863 // Check for headers sync timeouts 5864 if (state.fSyncStarted && peer->m_headers_sync_timeout < std::chrono::microseconds::max()) { 5865 // Detect whether this is a stalling initial-headers-sync peer 5866 if (m_chainman.m_best_header->Time() <= NodeClock::now() - 24h) { 5867 if (current_time > peer->m_headers_sync_timeout && nSyncStarted == 1 && (m_num_preferred_download_peers - state.fPreferredDownload >= 1)) { 5868 // Disconnect a peer (without NetPermissionFlags::NoBan permission) if it is our only sync peer, 5869 // and we have others we could be using instead. 5870 // Note: If all our peers are inbound, then we won't 5871 // disconnect our sync peer for stalling; we have bigger 5872 // problems if we can't get any outbound peers. 5873 if (!pto->HasPermission(NetPermissionFlags::NoBan)) { 5874 LogInfo("Timeout downloading headers, %s\n", pto->DisconnectMsg(fLogIPs)); 5875 pto->fDisconnect = true; 5876 return true; 5877 } else { 5878 LogInfo("Timeout downloading headers from noban peer, not %s\n", pto->DisconnectMsg(fLogIPs)); 5879 // Reset the headers sync state so that we have a 5880 // chance to try downloading from a different peer. 5881 // Note: this will also result in at least one more 5882 // getheaders message to be sent to 5883 // this peer (eventually). 5884 state.fSyncStarted = false; 5885 nSyncStarted--; 5886 peer->m_headers_sync_timeout = 0us; 5887 } 5888 } 5889 } else { 5890 // After we've caught up once, reset the timeout so we can't trigger 5891 // disconnect later. 5892 peer->m_headers_sync_timeout = std::chrono::microseconds::max(); 5893 } 5894 } 5895 5896 // Check that outbound peers have reasonable chains 5897 // GetTime() is used by this anti-DoS logic so we can test this using mocktime 5898 ConsiderEviction(*pto, *peer, GetTime<std::chrono::seconds>()); 5899 5900 // 5901 // Message: getdata (blocks) 5902 // 5903 std::vector<CInv> vGetData; 5904 if (CanServeBlocks(*peer) && ((sync_blocks_and_headers_from_peer && !IsLimitedPeer(*peer)) || !m_chainman.IsInitialBlockDownload()) && state.vBlocksInFlight.size() < MAX_BLOCKS_IN_TRANSIT_PER_PEER) { 5905 std::vector<const CBlockIndex*> vToDownload; 5906 NodeId staller = -1; 5907 auto get_inflight_budget = [&state]() { 5908 return std::max(0, MAX_BLOCKS_IN_TRANSIT_PER_PEER - static_cast<int>(state.vBlocksInFlight.size())); 5909 }; 5910 5911 // If a snapshot chainstate is in use, we want to find its next blocks 5912 // before the background chainstate to prioritize getting to network tip. 5913 FindNextBlocksToDownload(*peer, get_inflight_budget(), vToDownload, staller); 5914 if (m_chainman.BackgroundSyncInProgress() && !IsLimitedPeer(*peer)) { 5915 // If the background tip is not an ancestor of the snapshot block, 5916 // we need to start requesting blocks from their last common ancestor. 5917 const CBlockIndex *from_tip = LastCommonAncestor(m_chainman.GetBackgroundSyncTip(), m_chainman.GetSnapshotBaseBlock()); 5918 TryDownloadingHistoricalBlocks( 5919 *peer, 5920 get_inflight_budget(), 5921 vToDownload, from_tip, 5922 Assert(m_chainman.GetSnapshotBaseBlock())); 5923 } 5924 for (const CBlockIndex *pindex : vToDownload) { 5925 uint32_t nFetchFlags = GetFetchFlags(*peer); 5926 vGetData.emplace_back(MSG_BLOCK | nFetchFlags, pindex->GetBlockHash()); 5927 BlockRequested(pto->GetId(), *pindex); 5928 LogDebug(BCLog::NET, "Requesting block %s (%d) peer=%d\n", pindex->GetBlockHash().ToString(), 5929 pindex->nHeight, pto->GetId()); 5930 } 5931 if (state.vBlocksInFlight.empty() && staller != -1) { 5932 if (State(staller)->m_stalling_since == 0us) { 5933 State(staller)->m_stalling_since = current_time; 5934 LogDebug(BCLog::NET, "Stall started peer=%d\n", staller); 5935 } 5936 } 5937 } 5938 5939 // 5940 // Message: getdata (transactions) 5941 // 5942 { 5943 LOCK(m_tx_download_mutex); 5944 for (const GenTxid& gtxid : m_txdownloadman.GetRequestsToSend(pto->GetId(), current_time)) { 5945 vGetData.emplace_back(gtxid.IsWtxid() ? MSG_WTX : (MSG_TX | GetFetchFlags(*peer)), gtxid.ToUint256()); 5946 if (vGetData.size() >= MAX_GETDATA_SZ) { 5947 MakeAndPushMessage(*pto, NetMsgType::GETDATA, vGetData); 5948 vGetData.clear(); 5949 } 5950 } 5951 } 5952 5953 if (!vGetData.empty()) 5954 MakeAndPushMessage(*pto, NetMsgType::GETDATA, vGetData); 5955 } // release cs_main 5956 MaybeSendFeefilter(*pto, *peer, current_time); 5957 return true; 5958 }