1 // Copyright (c) 2009-2010 Satoshi Nakamoto
2 // Copyright (c) 2009-2022 The Limenka 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 <banman.h>
10 #include <blockencodings.h>
11 #include <blockfilter.h>
12 #include <chainparams.h>
13 #include <common/args.h>
14 #include <consensus/amount.h>
15 #include <consensus/validation.h>
16 #include <deploymentstatus.h>
17 #include <hash.h>
18 #include <headerssync.h>
19 #include <index/blockfilterindex.h>
20 #include <kernel/chain.h>
21 #include <kernel/mempool_entry.h>
22 #include <logging.h>
23 #include <merkleblock.h>
24 #include <netbase.h>
25 #include <netmessagemaker.h>
26 #include <node/blockstorage.h>
27 #include <node/timeoffsets.h>
28 #include <node/txdownloadman.h>
29 #include <node/txreconciliation.h>
30 #include <node/warnings.h>
31 #include <policy/fees.h>
32 #include <policy/policy.h>
33 #include <policy/settings.h>
34 #include <primitives/block.h>
35 #include <primitives/transaction.h>
36 #include <random.h>
37 #include <scheduler.h>
38 #include <streams.h>
39 #include <sync.h>
40 #include <tinyformat.h>
41 #include <txmempool.h>
42 #include <txorphanage.h>
43 #include <txrequest.h>
44 #include <util/check.h>
45 #include <util/strencodings.h>
46 #include <util/time.h>
47 #include <util/trace.h>
48 #include <validation.h>
49 50 #include <algorithm>
51 #include <atomic>
52 #include <future>
53 #include <memory>
54 #include <optional>
55 #include <ranges>
56 #include <typeinfo>
57 #include <utility>
58 59 using namespace util::hex_literals;
60 61 TRACEPOINT_SEMAPHORE(net, inbound_message);
62 TRACEPOINT_SEMAPHORE(net, misbehaving_connection);
63 64 /** Headers download timeout.
65 * Timeout = base + per_header * (expected number of headers) */
66 static constexpr auto HEADERS_DOWNLOAD_TIMEOUT_BASE = 15min;
67 static constexpr auto HEADERS_DOWNLOAD_TIMEOUT_PER_HEADER = 1ms;
68 /** How long to wait for a peer to respond to a getheaders request */
69 static constexpr auto HEADERS_RESPONSE_TIME{2min};
70 /** Protect at least this many outbound peers from disconnection due to slow/
71 * behind headers chain.
72 */
73 static constexpr int32_t MAX_OUTBOUND_PEERS_TO_PROTECT_FROM_DISCONNECT = 4;
74 /** Timeout for (unprotected) outbound peers to sync to our chainwork */
75 static constexpr auto CHAIN_SYNC_TIMEOUT{20min};
76 /** How frequently to check for stale tips */
77 static constexpr auto STALE_CHECK_INTERVAL{10min};
78 /** How frequently to check for extra outbound peers and disconnect */
79 static constexpr auto EXTRA_PEER_CHECK_INTERVAL{45s};
80 /** Minimum time an outbound-peer-eviction candidate must be connected for, in order to evict */
81 static constexpr auto MINIMUM_CONNECT_TIME{30s};
82 /** SHA256("main address relay")[0:8] */
83 static constexpr uint64_t RANDOMIZER_ID_ADDRESS_RELAY = 0x3cac0035b5866b90ULL;
84 /// Age after which a stale block will no longer be served if requested as
85 /// protection against fingerprinting. Set to one month, denominated in seconds.
86 static constexpr int STALE_RELAY_AGE_LIMIT = 30 * 24 * 60 * 60;
87 /// Age after which a block is considered historical for purposes of rate
88 /// limiting block relay. Set to one week, denominated in seconds.
89 static constexpr int HISTORICAL_BLOCK_AGE = 7 * 24 * 60 * 60;
90 /** Time between pings automatically sent out for latency probing and keepalive */
91 static constexpr auto PING_INTERVAL{2min};
92 /** The maximum number of entries in a locator */
93 static const unsigned int MAX_LOCATOR_SZ = 101;
94 /** The maximum number of entries in an 'inv' protocol message */
95 static const unsigned int MAX_INV_SZ = 50000;
96 /** Limit to avoid sending big packets. Not used in processing incoming GETDATA for compatibility */
97 static const unsigned int MAX_GETDATA_SZ = 1000;
98 /** Number of blocks that can be requested at any given time from a single peer. */
99 static const int MAX_BLOCKS_IN_TRANSIT_PER_PEER = 16;
100 /** Default time during which a peer must stall block download progress before being disconnected.
101 * the actual timeout is increased temporarily if peers are disconnected for hitting the timeout */
102 static constexpr auto BLOCK_STALLING_TIMEOUT_DEFAULT{2s};
103 /** Maximum timeout for stalling block download. */
104 static constexpr auto BLOCK_STALLING_TIMEOUT_MAX{64s};
105 /** Maximum depth of blocks we're willing to serve as compact blocks to peers
106 * when requested. For older blocks, a regular BLOCK response will be sent. */
107 static const int MAX_CMPCTBLOCK_DEPTH = 5;
108 /** Maximum depth of blocks we're willing to respond to GETBLOCKTXN requests for. */
109 static const int MAX_BLOCKTXN_DEPTH = 10;
110 static_assert(MAX_BLOCKTXN_DEPTH <= MIN_BLOCKS_TO_KEEP, "MAX_BLOCKTXN_DEPTH too high");
111 /** Size of the "block download window": how far ahead of our current height do we fetch?
112 * Larger windows tolerate larger download speed differences between peer, but increase the potential
113 * degree of disordering of blocks on disk (which make reindexing and pruning harder). We'll probably
114 * want to make this a per-peer adaptive value at some point. */
115 static const unsigned int BLOCK_DOWNLOAD_WINDOW = 1024;
116 /** Block download timeout base, expressed in multiples of the block interval (i.e. 10 min) */
117 static constexpr double BLOCK_DOWNLOAD_TIMEOUT_BASE = 1;
118 /** Additional block download timeout per parallel downloading peer (i.e. 5 min) */
119 static constexpr double BLOCK_DOWNLOAD_TIMEOUT_PER_PEER = 0.5;
120 /** Maximum number of headers to announce when relaying blocks with headers message.*/
121 static const unsigned int MAX_BLOCKS_TO_ANNOUNCE = 8;
122 /** Minimum blocks required to signal NODE_NETWORK_LIMITED */
123 static const unsigned int NODE_NETWORK_LIMITED_MIN_BLOCKS = 288;
124 /** Window, in blocks, for connecting to NODE_NETWORK_LIMITED peers */
125 static const unsigned int NODE_NETWORK_LIMITED_ALLOW_CONN_BLOCKS = 144;
126 /** Average delay between local address broadcasts */
127 static constexpr auto AVG_LOCAL_ADDRESS_BROADCAST_INTERVAL{24h};
128 /** Average delay between peer address broadcasts */
129 static constexpr auto AVG_ADDRESS_BROADCAST_INTERVAL{30s};
130 /** Delay between rotating the peers we relay a particular address to */
131 static constexpr auto ROTATE_ADDR_RELAY_DEST_INTERVAL{24h};
132 /** Average delay between trickled inventory transmissions for inbound peers.
133 * Blocks and peers with NetPermissionFlags::NoBan permission bypass this. */
134 static constexpr auto INBOUND_INVENTORY_BROADCAST_INTERVAL{5s};
135 /** Average delay between trickled inventory transmissions for outbound peers.
136 * Use a smaller delay as there is less privacy concern for them.
137 * Blocks and peers with NetPermissionFlags::NoBan permission bypass this. */
138 static constexpr auto OUTBOUND_INVENTORY_BROADCAST_INTERVAL{2s};
139 /** Maximum rate of inventory items to send per second.
140 * Limits the impact of low-fee transaction floods. */
141 static constexpr unsigned int INVENTORY_BROADCAST_PER_SECOND{14};
142 /** Target number of tx inventory items to send per transmission. */
143 static constexpr unsigned int INVENTORY_BROADCAST_TARGET = INVENTORY_BROADCAST_PER_SECOND * count_seconds(INBOUND_INVENTORY_BROADCAST_INTERVAL);
144 /** Maximum number of inventory items to send per transmission. */
145 static constexpr unsigned int INVENTORY_BROADCAST_MAX = 1000;
146 static_assert(INVENTORY_BROADCAST_MAX >= INVENTORY_BROADCAST_TARGET, "INVENTORY_BROADCAST_MAX too low");
147 static_assert(INVENTORY_BROADCAST_MAX <= node::MAX_PEER_TX_ANNOUNCEMENTS, "INVENTORY_BROADCAST_MAX too high");
148 /** Average delay between feefilter broadcasts in seconds. */
149 static constexpr auto AVG_FEEFILTER_BROADCAST_INTERVAL{10min};
150 /** Maximum feefilter broadcast delay after significant change. */
151 static constexpr auto MAX_FEEFILTER_CHANGE_DELAY{5min};
152 /** Maximum number of compact filters that may be requested with one getcfilters. See BIP 157. */
153 static constexpr uint32_t MAX_GETCFILTERS_SIZE = 1000;
154 /** Maximum number of cf hashes that may be requested with one getcfheaders. See BIP 157. */
155 static constexpr uint32_t MAX_GETCFHEADERS_SIZE = 2000;
156 /** the maximum percentage of addresses from our addrman to return in response to a getaddr message. */
157 static constexpr size_t MAX_PCT_ADDR_TO_SEND = 23;
158 /** The maximum number of address records permitted in an ADDR message. */
159 static constexpr size_t MAX_ADDR_TO_SEND{1000};
160 /** The maximum rate of address records we're willing to process on average. Can be bypassed using
161 * the NetPermissionFlags::Addr permission. */
162 static constexpr double MAX_ADDR_RATE_PER_SECOND{0.1};
163 /** The soft limit of the address processing token bucket (the regular MAX_ADDR_RATE_PER_SECOND
164 * based increments won't go above this, but the MAX_ADDR_TO_SEND increment following GETADDR
165 * is exempt from this limit). */
166 static constexpr size_t MAX_ADDR_PROCESSING_TOKEN_BUCKET{MAX_ADDR_TO_SEND};
167 /** The compactblocks version we support. See BIP 152. */
168 static constexpr uint64_t CMPCTBLOCKS_VERSION{2};
169 170 // Internal stuff
171 namespace {
172 /** Blocks that are in flight, and that are in the queue to be downloaded. */
173 struct QueuedBlock {
174 /** BlockIndex. We must have this since we only request blocks when we've already validated the header. */
175 const CBlockIndex* pindex;
176 /** Optional, used for CMPCTBLOCK downloads */
177 std::unique_ptr<PartiallyDownloadedBlock> partialBlock;
178 };
179 180 /**
181 * Data structure for an individual peer. This struct is not protected by
182 * cs_main since it does not contain validation-critical data.
183 *
184 * Memory is owned by shared pointers and this object is destructed when
185 * the refcount drops to zero.
186 *
187 * Mutexes inside this struct must not be held when locking m_peer_mutex.
188 *
189 * TODO: move most members from CNodeState to this structure.
190 * TODO: move remaining application-layer data members from CNode to this structure.
191 */
192 struct Peer {
193 /** Same id as the CNode object for this peer */
194 const NodeId m_id{0};
195 196 /** Services we offered to this peer.
197 *
198 * This is supplied by CConnman during peer initialization. It's const
199 * because there is no protocol defined for renegotiating services
200 * initially offered to a peer. The set of local services we offer should
201 * not change after initialization.
202 *
203 * An interesting example of this is NODE_NETWORK and initial block
204 * download: a node which starts up from scratch doesn't have any blocks
205 * to serve, but still advertises NODE_NETWORK because it will eventually
206 * fulfill this role after IBD completes. P2P code is written in such a
207 * way that it can gracefully handle peers who don't make good on their
208 * service advertisements. */
209 const ServiceFlags m_our_services;
210 /** Services this peer offered to us. */
211 std::atomic<ServiceFlags> m_their_services{NODE_NONE};
212 213 //! Whether this peer is an inbound connection
214 const bool m_is_inbound;
215 216 /** Protects misbehavior data members */
217 Mutex m_misbehavior_mutex;
218 /** Whether this peer should be disconnected and marked as discouraged (unless it has NetPermissionFlags::NoBan permission). */
219 bool m_should_discourage GUARDED_BY(m_misbehavior_mutex){false};
220 221 /** Protects block inventory data members */
222 Mutex m_block_inv_mutex;
223 /** List of blocks that we'll announce via an `inv` message.
224 * There is no final sorting before sending, as they are always sent
225 * immediately and in the order requested. */
226 std::vector<uint256> m_blocks_for_inv_relay GUARDED_BY(m_block_inv_mutex);
227 /** Unfiltered list of blocks that we'd like to announce via a `headers`
228 * message. If we can't announce via a `headers` message, we'll fall back to
229 * announcing via `inv`. */
230 std::vector<uint256> m_blocks_for_headers_relay GUARDED_BY(m_block_inv_mutex);
231 /** The final block hash that we sent in an `inv` message to this peer.
232 * When the peer requests this block, we send an `inv` message to trigger
233 * the peer to request the next sequence of block hashes.
234 * Most peers use headers-first syncing, which doesn't use this mechanism */
235 uint256 m_continuation_block GUARDED_BY(m_block_inv_mutex) {};
236 237 /** Set to true once initial VERSION message was sent (only relevant for outbound peers). */
238 bool m_outbound_version_message_sent GUARDED_BY(NetEventsInterface::g_msgproc_mutex){false};
239 240 /** This peer's reported block height when we connected */
241 std::atomic<int> m_starting_height{-1};
242 243 /** The pong reply we're expecting, or 0 if no pong expected. */
244 std::atomic<uint64_t> m_ping_nonce_sent{0};
245 /** When the last ping was sent, or 0 if no ping was ever sent */
246 std::atomic<std::chrono::microseconds> m_ping_start{0us};
247 /** Whether a ping has been requested by the user */
248 std::atomic<bool> m_ping_queued{false};
249 250 /** Whether this peer relays txs via wtxid */
251 std::atomic<bool> m_wtxid_relay{false};
252 /** The feerate in the most recent BIP133 `feefilter` message sent to the peer.
253 * It is *not* a p2p protocol violation for the peer to send us
254 * transactions with a lower fee rate than this. See BIP133. */
255 CAmount m_fee_filter_sent GUARDED_BY(NetEventsInterface::g_msgproc_mutex){0};
256 /** Timestamp after which we will send the next BIP133 `feefilter` message
257 * to the peer. */
258 std::chrono::microseconds m_next_send_feefilter GUARDED_BY(NetEventsInterface::g_msgproc_mutex){0};
259 260 struct TxRelay {
261 mutable RecursiveMutex m_bloom_filter_mutex;
262 /** Whether we relay transactions to this peer. */
263 bool m_relay_txs GUARDED_BY(m_bloom_filter_mutex){false};
264 /** A bloom filter for which transactions to announce to the peer. See BIP37. */
265 std::unique_ptr<CBloomFilter> m_bloom_filter PT_GUARDED_BY(m_bloom_filter_mutex) GUARDED_BY(m_bloom_filter_mutex){nullptr};
266 267 mutable RecursiveMutex m_tx_inventory_mutex;
268 /** A filter of all the (w)txids that the peer has announced to
269 * us or we have announced to the peer. We use this to avoid announcing
270 * the same (w)txid to a peer that already has the transaction. */
271 CRollingBloomFilter m_tx_inventory_known_filter GUARDED_BY(m_tx_inventory_mutex){50000, 0.000001};
272 /** Set of transaction ids we still have to announce (txid for
273 * non-wtxid-relay peers, wtxid for wtxid-relay peers). We use the
274 * mempool to sort transactions in dependency order before relay, so
275 * this does not have to be sorted. */
276 std::set<uint256> m_tx_inventory_to_send GUARDED_BY(m_tx_inventory_mutex);
277 /** Whether the peer has requested us to send our complete mempool. Only
278 * permitted if the peer has NetPermissionFlags::Mempool or we advertise
279 * NODE_BLOOM. See BIP35. */
280 bool m_send_mempool GUARDED_BY(m_tx_inventory_mutex){false};
281 /** The next time after which we will send an `inv` message containing
282 * transaction announcements to this peer. */
283 std::chrono::microseconds m_next_inv_send_time GUARDED_BY(m_tx_inventory_mutex){0};
284 /** The mempool sequence num at which we sent the last `inv` message to this peer.
285 * Can relay txs with lower sequence numbers than this (see CTxMempool::info_for_relay). */
286 uint64_t m_last_inv_sequence GUARDED_BY(NetEventsInterface::g_msgproc_mutex){1};
287 288 /** Minimum fee rate with which to filter transaction announcements to this node. See BIP133. */
289 std::atomic<CAmount> m_fee_filter_received{0};
290 };
291 292 /* Initializes a TxRelay struct for this peer. Can be called at most once for a peer. */
293 TxRelay* SetTxRelay() EXCLUSIVE_LOCKS_REQUIRED(!m_tx_relay_mutex)
294 {
295 LOCK(m_tx_relay_mutex);
296 Assume(!m_tx_relay);
297 m_tx_relay = std::make_unique<Peer::TxRelay>();
298 return m_tx_relay.get();
299 };
300 301 TxRelay* GetTxRelay() EXCLUSIVE_LOCKS_REQUIRED(!m_tx_relay_mutex)
302 {
303 return WITH_LOCK(m_tx_relay_mutex, return m_tx_relay.get());
304 };
305 306 /** A vector of addresses to send to the peer, limited to MAX_ADDR_TO_SEND. */
307 std::vector<CAddress> m_addrs_to_send GUARDED_BY(NetEventsInterface::g_msgproc_mutex);
308 /** Probabilistic filter to track recent addr messages relayed with this
309 * peer. Used to avoid relaying redundant addresses to this peer.
310 *
311 * We initialize this filter for outbound peers (other than
312 * block-relay-only connections) or when an inbound peer sends us an
313 * address related message (ADDR, ADDRV2, GETADDR).
314 *
315 * Presence of this filter must correlate with m_addr_relay_enabled.
316 **/
317 std::unique_ptr<CRollingBloomFilter> m_addr_known GUARDED_BY(NetEventsInterface::g_msgproc_mutex);
318 /** Whether we are participating in address relay with this connection.
319 *
320 * We set this bool to true for outbound peers (other than
321 * block-relay-only connections), or when an inbound peer sends us an
322 * address related message (ADDR, ADDRV2, GETADDR).
323 *
324 * We use this bool to decide whether a peer is eligible for gossiping
325 * addr messages. This avoids relaying to peers that are unlikely to
326 * forward them, effectively blackholing self announcements. Reasons
327 * peers might support addr relay on the link include that they connected
328 * to us as a block-relay-only peer or they are a light client.
329 *
330 * This field must correlate with whether m_addr_known has been
331 * initialized.*/
332 std::atomic_bool m_addr_relay_enabled{false};
333 /** Whether a getaddr request to this peer is outstanding. */
334 bool m_getaddr_sent GUARDED_BY(NetEventsInterface::g_msgproc_mutex){false};
335 /** Guards address sending timers. */
336 mutable Mutex m_addr_send_times_mutex;
337 /** Time point to send the next ADDR message to this peer. */
338 std::chrono::microseconds m_next_addr_send GUARDED_BY(m_addr_send_times_mutex){0};
339 /** Time point to possibly re-announce our local address to this peer. */
340 std::chrono::microseconds m_next_local_addr_send GUARDED_BY(m_addr_send_times_mutex){0};
341 /** Whether the peer has signaled support for receiving ADDRv2 (BIP155)
342 * messages, indicating a preference to receive ADDRv2 instead of ADDR ones. */
343 std::atomic_bool m_wants_addrv2{false};
344 /** Whether this peer has already sent us a getaddr message. */
345 bool m_getaddr_recvd GUARDED_BY(NetEventsInterface::g_msgproc_mutex){false};
346 /** Number of addresses that can be processed from this peer. Start at 1 to
347 * permit self-announcement. */
348 double m_addr_token_bucket GUARDED_BY(NetEventsInterface::g_msgproc_mutex){1.0};
349 /** When m_addr_token_bucket was last updated */
350 std::chrono::microseconds m_addr_token_timestamp GUARDED_BY(NetEventsInterface::g_msgproc_mutex){GetTime<std::chrono::microseconds>()};
351 /** Total number of addresses that were dropped due to rate limiting. */
352 std::atomic<uint64_t> m_addr_rate_limited{0};
353 /** Total number of addresses that were processed (excludes rate-limited ones). */
354 std::atomic<uint64_t> m_addr_processed{0};
355 356 /** Whether we've sent this peer a getheaders in response to an inv prior to initial-headers-sync completing */
357 bool m_inv_triggered_getheaders_before_sync GUARDED_BY(NetEventsInterface::g_msgproc_mutex){false};
358 359 /** Protects m_getdata_requests **/
360 Mutex m_getdata_requests_mutex;
361 /** Work queue of items requested by this peer **/
362 std::deque<CInv> m_getdata_requests GUARDED_BY(m_getdata_requests_mutex);
363 364 /** Time of the last getheaders message to this peer */
365 NodeClock::time_point m_last_getheaders_timestamp GUARDED_BY(NetEventsInterface::g_msgproc_mutex){};
366 367 /** Protects m_headers_sync **/
368 Mutex m_headers_sync_mutex;
369 /** Headers-sync state for this peer (eg for initial sync, or syncing large
370 * reorgs) **/
371 std::unique_ptr<HeadersSyncState> m_headers_sync PT_GUARDED_BY(m_headers_sync_mutex) GUARDED_BY(m_headers_sync_mutex) {};
372 373 /** Whether we've sent our peer a sendheaders message. **/
374 std::atomic<bool> m_sent_sendheaders{false};
375 376 /** When to potentially disconnect peer for stalling headers download */
377 std::chrono::microseconds m_headers_sync_timeout GUARDED_BY(NetEventsInterface::g_msgproc_mutex){0us};
378 379 /** Whether this peer wants invs or headers (when possible) for block announcements */
380 bool m_prefers_headers GUARDED_BY(NetEventsInterface::g_msgproc_mutex){false};
381 382 /** Time offset computed during the version handshake based on the
383 * timestamp the peer sent in the version message. */
384 std::atomic<std::chrono::seconds> m_time_offset{0s};
385 386 /** Number of consecutive deserialization failures from this peer.
387 * Used to detect and disconnect peers sending malformed messages. */
388 uint32_t m_deserialization_failures GUARDED_BY(NetEventsInterface::g_msgproc_mutex){0};
389 390 explicit Peer(NodeId id, ServiceFlags our_services, bool is_inbound)
391 : m_id{id}
392 , m_our_services{our_services}
393 , m_is_inbound{is_inbound}
394 {}
395 396 private:
397 mutable Mutex m_tx_relay_mutex;
398 399 /** Transaction relay data. May be a nullptr. */
400 std::unique_ptr<TxRelay> m_tx_relay GUARDED_BY(m_tx_relay_mutex);
401 };
402 403 using PeerRef = std::shared_ptr<Peer>;
404 405 /**
406 * Maintain validation-specific state about nodes, protected by cs_main, instead
407 * by CNode's own locks. This simplifies asynchronous operation, where
408 * processing of incoming data is done after the ProcessMessage call returns,
409 * and we're no longer holding the node's locks.
410 */
411 struct CNodeState {
412 //! The best known block we know this peer has announced.
413 const CBlockIndex* pindexBestKnownBlock{nullptr};
414 //! The hash of the last unknown block this peer has announced.
415 uint256 hashLastUnknownBlock{};
416 //! The last full block we both have.
417 const CBlockIndex* pindexLastCommonBlock{nullptr};
418 //! The best header we have sent our peer.
419 const CBlockIndex* pindexBestHeaderSent{nullptr};
420 //! Whether we've started headers synchronization with this peer.
421 bool fSyncStarted{false};
422 //! Since when we're stalling block download progress (in microseconds), or 0.
423 std::chrono::microseconds m_stalling_since{0us};
424 std::list<QueuedBlock> vBlocksInFlight;
425 //! When the first entry in vBlocksInFlight started downloading. Don't care when vBlocksInFlight is empty.
426 std::chrono::microseconds m_downloading_since{0us};
427 //! Whether we consider this a preferred download peer.
428 bool fPreferredDownload{false};
429 /** Whether this peer wants invs or cmpctblocks (when possible) for block announcements. */
430 bool m_requested_hb_cmpctblocks{false};
431 /** Whether this peer will send us cmpctblocks if we request them. */
432 bool m_provides_cmpctblocks{false};
433 434 /** State used to enforce CHAIN_SYNC_TIMEOUT and EXTRA_PEER_CHECK_INTERVAL logic.
435 *
436 * Both are only in effect for outbound, non-manual, non-protected connections.
437 * Any peer protected (m_protect = true) is not chosen for eviction. A peer is
438 * marked as protected if all of these are true:
439 * - its connection type is IsBlockOnlyConn() == false
440 * - it gave us a valid connecting header
441 * - we haven't reached MAX_OUTBOUND_PEERS_TO_PROTECT_FROM_DISCONNECT yet
442 * - its chain tip has at least as much work as ours
443 *
444 * CHAIN_SYNC_TIMEOUT: if a peer's best known block has less work than our tip,
445 * set a timeout CHAIN_SYNC_TIMEOUT in the future:
446 * - If at timeout their best known block now has more work than our tip
447 * when the timeout was set, then either reset the timeout or clear it
448 * (after comparing against our current tip's work)
449 * - If at timeout their best known block still has less work than our
450 * tip did when the timeout was set, then send a getheaders message,
451 * and set a shorter timeout, HEADERS_RESPONSE_TIME seconds in future.
452 * If their best known block is still behind when that new timeout is
453 * reached, disconnect.
454 *
455 * EXTRA_PEER_CHECK_INTERVAL: after each interval, if we have too many outbound peers,
456 * drop the outbound one that least recently announced us a new block.
457 */
458 struct ChainSyncTimeoutState {
459 //! A timeout used for checking whether our peer has sufficiently synced
460 std::chrono::seconds m_timeout{0s};
461 //! A header with the work we require on our peer's chain
462 const CBlockIndex* m_work_header{nullptr};
463 //! After timeout is reached, set to true after sending getheaders
464 bool m_sent_getheaders{false};
465 //! Whether this peer is protected from disconnection due to a bad/slow chain
466 bool m_protect{false};
467 };
468 469 ChainSyncTimeoutState m_chain_sync;
470 471 //! Time of last new block announcement
472 int64_t m_last_block_announcement{0};
473 };
474 475 class PeerManagerImpl final : public PeerManager
476 {
477 public:
478 PeerManagerImpl(CConnman& connman, AddrMan& addrman,
479 BanMan* banman, ChainstateManager& chainman,
480 CTxMemPool& pool, node::Warnings& warnings, Options opts);
481 482 /** Overridden from CValidationInterface. */
483 void ActiveTipChange(const CBlockIndex& new_tip, bool) override
484 EXCLUSIVE_LOCKS_REQUIRED(!m_tx_download_mutex);
485 void BlockConnected(ChainstateRole role, const std::shared_ptr<const CBlock>& pblock, const CBlockIndex* pindexConnected) override
486 EXCLUSIVE_LOCKS_REQUIRED(!m_tx_download_mutex);
487 void BlockDisconnected(const std::shared_ptr<const CBlock> &block, const CBlockIndex* pindex) override
488 EXCLUSIVE_LOCKS_REQUIRED(!m_tx_download_mutex);
489 void UpdatedBlockTip(const CBlockIndex *pindexNew, const CBlockIndex *pindexFork, bool fInitialDownload) override
490 EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
491 void BlockChecked(const CBlock& block, const BlockValidationState& state) override
492 EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
493 void NewPoWValidBlock(const CBlockIndex *pindex, const std::shared_ptr<const CBlock>& pblock) override
494 EXCLUSIVE_LOCKS_REQUIRED(!m_most_recent_block_mutex);
495 496 /** Implement NetEventsInterface */
497 void InitializeNode(const CNode& node, ServiceFlags our_services) override EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex, !m_tx_download_mutex);
498 void FinalizeNode(const CNode& node) override EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex, !m_headers_presync_mutex, !m_tx_download_mutex);
499 bool HasAllDesirableServiceFlags(ServiceFlags services) const override;
500 bool ProcessMessages(CNode* pfrom, std::atomic<bool>& interrupt) override
501 EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex, !m_most_recent_block_mutex, !m_headers_presync_mutex, g_msgproc_mutex, !m_tx_download_mutex);
502 bool SendMessages(CNode* pto) override
503 EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex, !m_most_recent_block_mutex, g_msgproc_mutex, !m_tx_download_mutex);
504 505 /** Implement PeerManager */
506 void StartScheduledTasks(CScheduler& scheduler) override;
507 void CheckForStaleTipAndEvictPeers() override;
508 std::optional<std::string> FetchBlock(NodeId peer_id, const uint256& hash, const CBlockIndex* block_index) override
509 EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
510 bool GetNodeStateStats(NodeId nodeid, CNodeStateStats& stats) const override EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
511 std::vector<TxOrphanage::OrphanTxBase> GetOrphanTransactions() override EXCLUSIVE_LOCKS_REQUIRED(!m_tx_download_mutex);
512 PeerManagerInfo GetInfo() const override EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
513 void LimitOrphanTxSize(uint32_t nMaxOrphans) override EXCLUSIVE_LOCKS_REQUIRED(!m_tx_download_mutex);
514 void SendPings() override EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
515 void RelayTransaction(const uint256& txid, const uint256& wtxid) override EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
516 void SetBestBlock(int height, std::chrono::seconds time) override
517 {
518 m_best_height = height;
519 m_best_block_time = time;
520 };
521 void UnitTestMisbehaving(NodeId peer_id) override EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex) { Misbehaving(*Assert(GetPeerRef(peer_id)), ""); };
522 void ProcessMessage(CNode& pfrom, const std::string& msg_type, DataStream& vRecv,
523 const std::chrono::microseconds time_received, const std::atomic<bool>& interruptMsgProc) override
524 EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex, !m_most_recent_block_mutex, !m_headers_presync_mutex, g_msgproc_mutex, !m_tx_download_mutex);
525 void UpdateLastBlockAnnounceTime(NodeId node, int64_t time_in_seconds) override;
526 ServiceFlags GetDesirableServiceFlags(ServiceFlags services) const override;
527 int GetNumberOfPeersWithValidatedDownloads() const override EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
528 529 private:
530 /** Consider evicting an outbound peer based on the amount of time they've been behind our tip */
531 void ConsiderEviction(CNode& pto, Peer& peer, std::chrono::seconds time_in_seconds) EXCLUSIVE_LOCKS_REQUIRED(cs_main, g_msgproc_mutex);
532 533 /** If we have extra outbound peers, try to disconnect the one with the oldest block announcement */
534 void EvictExtraOutboundPeers(std::chrono::seconds now) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
535 536 /** Retrieve unbroadcast transactions from the mempool and reattempt sending to peers */
537 void ReattemptInitialBroadcast(CScheduler& scheduler) EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
538 539 /** Get a shared pointer to the Peer object.
540 * May return an empty shared_ptr if the Peer object can't be found. */
541 PeerRef GetPeerRef(NodeId id) const EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
542 543 /** Get a shared pointer to the Peer object and remove it from m_peer_map.
544 * May return an empty shared_ptr if the Peer object can't be found. */
545 PeerRef RemovePeer(NodeId id) EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
546 547 /** Mark a peer as misbehaving, which will cause it to be disconnected and its
548 * address discouraged. */
549 void Misbehaving(Peer& peer, const std::string& message);
550 551 /**
552 * Potentially mark a node discouraged based on the contents of a BlockValidationState object
553 *
554 * @param[in] via_compact_block this bool is passed in because net_processing should
555 * punish peers differently depending on whether the data was provided in a compact
556 * block message or not. If the compact block had a valid header, but contained invalid
557 * txs, the peer should not be punished. See BIP 152.
558 */
559 void MaybePunishNodeForBlock(NodeId nodeid, const BlockValidationState& state,
560 bool via_compact_block, const std::string& message = "")
561 EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
562 563 /** Maybe disconnect a peer and discourage future connections from its address.
564 *
565 * @param[in] pnode The node to check.
566 * @param[in] peer The peer object to check.
567 * @return True if the peer was marked for disconnection in this function
568 */
569 bool MaybeDiscourageAndDisconnect(CNode& pnode, Peer& peer);
570 571 /** Handle a transaction whose result was not MempoolAcceptResult::ResultType::VALID.
572 * @param[in] first_time_failure Whether we should consider inserting into vExtraTxnForCompact, adding
573 * a new orphan to resolve, or looking for a package to submit.
574 * Set to true for transactions just received over p2p.
575 * Set to false if the tx has already been rejected before,
576 * e.g. is already in the orphanage, to avoid adding duplicate entries.
577 * Updates m_txrequest, m_lazy_recent_rejects, m_lazy_recent_rejects_reconsiderable, m_orphanage, and vExtraTxnForCompact.
578 *
579 * @returns a PackageToValidate if this transaction has a reconsiderable failure and an eligible package was found,
580 * or std::nullopt otherwise.
581 */
582 std::optional<node::PackageToValidate> ProcessInvalidTx(NodeId nodeid, const CTransactionRef& tx, const TxValidationState& result,
583 bool first_time_failure)
584 EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex, g_msgproc_mutex, m_tx_download_mutex);
585 586 /** Handle a transaction whose result was MempoolAcceptResult::ResultType::VALID.
587 * Updates m_txrequest, m_orphanage, and vExtraTxnForCompact. Also queues the tx for relay. */
588 void ProcessValidTx(NodeId nodeid, const CTransactionRef& tx, const std::list<CTransactionRef>& replaced_transactions)
589 EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex, g_msgproc_mutex, m_tx_download_mutex);
590 591 /** Handle the results of package validation: calls ProcessValidTx and ProcessInvalidTx for
592 * individual transactions, and caches rejection for the package as a group.
593 */
594 void ProcessPackageResult(const node::PackageToValidate& package_to_validate, const PackageMempoolAcceptResult& package_result)
595 EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex, g_msgproc_mutex, m_tx_download_mutex);
596 597 /**
598 * Reconsider orphan transactions after a parent has been accepted to the mempool.
599 *
600 * @peer[in] peer The peer whose orphan transactions we will reconsider. Generally only
601 * one orphan will be reconsidered on each call of this function. If an
602 * accepted orphan has orphaned children, those will need to be
603 * reconsidered, creating more work, possibly for other peers.
604 * @return True if meaningful work was done (an orphan was accepted/rejected).
605 * If no meaningful work was done, then the work set for this peer
606 * will be empty.
607 */
608 bool ProcessOrphanTx(Peer& peer)
609 EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex, g_msgproc_mutex, !m_tx_download_mutex);
610 611 /** Process a single headers message from a peer.
612 *
613 * @param[in] pfrom CNode of the peer
614 * @param[in] peer The peer sending us the headers
615 * @param[in] headers The headers received. Note that this may be modified within ProcessHeadersMessage.
616 * @param[in] via_compact_block Whether this header came in via compact block handling.
617 */
618 void ProcessHeadersMessage(CNode& pfrom, Peer& peer,
619 std::vector<CBlockHeader>&& headers,
620 bool via_compact_block)
621 EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex, !m_headers_presync_mutex, g_msgproc_mutex);
622 /** Various helpers for headers processing, invoked by ProcessHeadersMessage() */
623 /** Return true if headers are continuous and have valid proof-of-work (DoS points assigned on failure) */
624 bool CheckHeadersPoW(const std::vector<CBlockHeader>& headers, const Consensus::Params& consensusParams, Peer& peer);
625 /** Calculate an anti-DoS work threshold for headers chains */
626 arith_uint256 GetAntiDoSWorkThreshold();
627 /** Deal with state tracking and headers sync for peers that send
628 * non-connecting headers (this can happen due to BIP 130 headers
629 * announcements for blocks interacting with the 2hr (MAX_FUTURE_BLOCK_TIME) rule). */
630 void HandleUnconnectingHeaders(CNode& pfrom, Peer& peer, const std::vector<CBlockHeader>& headers) EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex);
631 /** Return true if the headers connect to each other, false otherwise */
632 bool CheckHeadersAreContinuous(const std::vector<CBlockHeader>& headers) const;
633 /** Try to continue a low-work headers sync that has already begun.
634 * Assumes the caller has already verified the headers connect, and has
635 * checked that each header satisfies the proof-of-work target included in
636 * the header.
637 * @param[in] peer The peer we're syncing with.
638 * @param[in] pfrom CNode of the peer
639 * @param[in,out] headers The headers to be processed.
640 * @return True if the passed in headers were successfully processed
641 * as the continuation of a low-work headers sync in progress;
642 * false otherwise.
643 * If false, the passed in headers will be returned back to
644 * the caller.
645 * If true, the returned headers may be empty, indicating
646 * there is no more work for the caller to do; or the headers
647 * may be populated with entries that have passed anti-DoS
648 * checks (and therefore may be validated for block index
649 * acceptance by the caller).
650 */
651 bool IsContinuationOfLowWorkHeadersSync(Peer& peer, CNode& pfrom,
652 std::vector<CBlockHeader>& headers)
653 EXCLUSIVE_LOCKS_REQUIRED(peer.m_headers_sync_mutex, !m_headers_presync_mutex, g_msgproc_mutex);
654 /** Check work on a headers chain to be processed, and if insufficient,
655 * initiate our anti-DoS headers sync mechanism.
656 *
657 * @param[in] peer The peer whose headers we're processing.
658 * @param[in] pfrom CNode of the peer
659 * @param[in] chain_start_header Where these headers connect in our index.
660 * @param[in,out] headers The headers to be processed.
661 *
662 * @return True if chain was low work (headers will be empty after
663 * calling); false otherwise.
664 */
665 bool TryLowWorkHeadersSync(Peer& peer, CNode& pfrom,
666 const CBlockIndex* chain_start_header,
667 std::vector<CBlockHeader>& headers)
668 EXCLUSIVE_LOCKS_REQUIRED(!peer.m_headers_sync_mutex, !m_peer_mutex, !m_headers_presync_mutex, g_msgproc_mutex);
669 670 /** Return true if the given header is an ancestor of
671 * m_chainman.m_best_header or our current tip */
672 bool IsAncestorOfBestHeaderOrTip(const CBlockIndex* header) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
673 674 /** Request further headers from this peer with a given locator.
675 * We don't issue a getheaders message if we have a recent one outstanding.
676 * This returns true if a getheaders is actually sent, and false otherwise.
677 */
678 bool MaybeSendGetHeaders(CNode& pfrom, const CBlockLocator& locator, Peer& peer) EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex);
679 /** Potentially fetch blocks from this peer upon receipt of a new headers tip */
680 void HeadersDirectFetchBlocks(CNode& pfrom, const Peer& peer, const CBlockIndex& last_header);
681 /** Update peer state based on received headers message */
682 void UpdatePeerStateForReceivedHeaders(CNode& pfrom, Peer& peer, const CBlockIndex& last_header, bool received_new_header, bool may_have_more_headers)
683 EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex);
684 685 void SendBlockTransactions(CNode& pfrom, Peer& peer, const CBlock& block, const BlockTransactionsRequest& req);
686 687 /** Send a message to a peer */
688 void PushMessage(CNode& node, CSerializedNetMsg&& msg) const { m_connman.PushMessage(&node, std::move(msg)); }
689 template <typename... Args>
690 void MakeAndPushMessage(CNode& node, std::string msg_type, Args&&... args) const
691 {
692 m_connman.PushMessage(&node, NetMsg::Make(std::move(msg_type), std::forward<Args>(args)...));
693 }
694 695 /** Send a version message to a peer */
696 void PushNodeVersion(CNode& pnode, const Peer& peer);
697 698 /** Send a ping message every PING_INTERVAL or if requested via RPC. May
699 * mark the peer to be disconnected if a ping has timed out.
700 * We use mockable time for ping timeouts, so setmocktime may cause pings
701 * to time out. */
702 void MaybeSendPing(CNode& node_to, Peer& peer, std::chrono::microseconds now);
703 704 /** Send `addr` messages on a regular schedule. */
705 void MaybeSendAddr(CNode& node, Peer& peer, std::chrono::microseconds current_time) EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex);
706 707 /** Send a single `sendheaders` message, after we have completed headers sync with a peer. */
708 void MaybeSendSendHeaders(CNode& node, Peer& peer) EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex);
709 710 /** Relay (gossip) an address to a few randomly chosen nodes.
711 *
712 * @param[in] originator The id of the peer that sent us the address. We don't want to relay it back.
713 * @param[in] addr Address to relay.
714 * @param[in] fReachable Whether the address' network is reachable. We relay unreachable
715 * addresses less.
716 */
717 void RelayAddress(NodeId originator, const CAddress& addr, bool fReachable) EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex, g_msgproc_mutex);
718 719 /** Send `feefilter` message. */
720 void MaybeSendFeefilter(CNode& node, Peer& peer, std::chrono::microseconds current_time) EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex);
721 722 FastRandomContext m_rng GUARDED_BY(NetEventsInterface::g_msgproc_mutex);
723 724 FeeFilterRounder m_fee_filter_rounder GUARDED_BY(NetEventsInterface::g_msgproc_mutex);
725 726 const CChainParams& m_chainparams;
727 CConnman& m_connman;
728 AddrMan& m_addrman;
729 /** Pointer to this node's banman. May be nullptr - check existence before dereferencing. */
730 BanMan* const m_banman;
731 ChainstateManager& m_chainman;
732 CTxMemPool& m_mempool;
733 734 /** Synchronizes tx download including TxRequestTracker, rejection filters, and TxOrphanage.
735 * Lock invariants:
736 * - A txhash (txid or wtxid) in m_txrequest is not also in m_orphanage.
737 * - A txhash (txid or wtxid) in m_txrequest is not also in m_lazy_recent_rejects.
738 * - A txhash (txid or wtxid) in m_txrequest is not also in m_lazy_recent_rejects_reconsiderable.
739 * - A txhash (txid or wtxid) in m_txrequest is not also in m_lazy_recent_confirmed_transactions.
740 * - Each data structure's limits hold (m_orphanage max size, m_txrequest per-peer limits, etc).
741 */
742 Mutex m_tx_download_mutex ACQUIRED_BEFORE(m_mempool.cs);
743 node::TxDownloadManager m_txdownloadman GUARDED_BY(m_tx_download_mutex);
744 745 std::unique_ptr<TxReconciliationTracker> m_txreconciliation;
746 747 /** The height of the best chain */
748 std::atomic<int> m_best_height{-1};
749 /** The time of the best chain tip block */
750 std::atomic<std::chrono::seconds> m_best_block_time{0s};
751 752 /** Next time to check for stale tip */
753 std::chrono::seconds m_stale_tip_check_time GUARDED_BY(cs_main){0s};
754 755 node::Warnings& m_warnings;
756 TimeOffsets m_outbound_time_offsets{m_warnings};
757 758 const Options m_opts;
759 760 bool RejectIncomingTxs(const CNode& peer) const;
761 762 /** Whether we've completed initial sync yet, for determining when to turn
763 * on extra block-relay-only peers. */
764 bool m_initial_sync_finished GUARDED_BY(cs_main){false};
765 766 /** Protects m_peer_map. This mutex must not be locked while holding a lock
767 * on any of the mutexes inside a Peer object. */
768 mutable Mutex m_peer_mutex;
769 /**
770 * Map of all Peer objects, keyed by peer id. This map is protected
771 * by the m_peer_mutex. Once a shared pointer reference is
772 * taken, the lock may be released. Individual fields are protected by
773 * their own locks.
774 */
775 std::map<NodeId, PeerRef> m_peer_map GUARDED_BY(m_peer_mutex);
776 777 /** Map maintaining per-node state. */
778 std::map<NodeId, CNodeState> m_node_states GUARDED_BY(cs_main);
779 780 /** Get a pointer to a const CNodeState, used when not mutating the CNodeState object. */
781 const CNodeState* State(NodeId pnode) const EXCLUSIVE_LOCKS_REQUIRED(cs_main);
782 /** Get a pointer to a mutable CNodeState. */
783 CNodeState* State(NodeId pnode) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
784 785 uint32_t GetFetchFlags(const Peer& peer) const;
786 787 std::map<uint64_t, std::chrono::microseconds> m_next_inv_to_inbounds_per_network_key GUARDED_BY(g_msgproc_mutex);
788 789 /** Number of nodes with fSyncStarted. */
790 int nSyncStarted GUARDED_BY(cs_main) = 0;
791 792 /** Hash of the last block we received via INV */
793 uint256 m_last_block_inv_triggering_headers_sync GUARDED_BY(g_msgproc_mutex){};
794 795 /**
796 * Sources of received blocks, saved to be able punish them when processing
797 * happens afterwards.
798 * Set mapBlockSource[hash].second to false if the node should not be
799 * punished if the block is invalid.
800 */
801 std::map<uint256, std::pair<NodeId, bool>> mapBlockSource GUARDED_BY(cs_main);
802 803 /** Number of peers with wtxid relay. */
804 std::atomic<int> m_wtxid_relay_peers{0};
805 806 /** Number of outbound peers without NODE_REDUCED_DATA (BIP-110). Limited to 2. */
807 std::atomic<unsigned int> m_num_non_bip110_outbound{0};
808 809 /** Number of outbound peers with m_chain_sync.m_protect. */
810 int m_outbound_peers_with_protect_from_disconnect GUARDED_BY(cs_main) = 0;
811 812 /** Number of preferable block download peers. */
813 int m_num_preferred_download_peers GUARDED_BY(cs_main){0};
814 815 /** Stalling timeout for blocks in IBD */
816 std::atomic<std::chrono::seconds> m_block_stalling_timeout{BLOCK_STALLING_TIMEOUT_DEFAULT};
817 818 /**
819 * For sending `inv`s to inbound peers, we use a single (exponentially
820 * distributed) timer for all peers with the same network key. If we used a separate timer for each
821 * peer, a spy node could make multiple inbound connections to us to
822 * accurately determine when we received a transaction (and potentially
823 * determine the transaction's origin). Each network key has its own timer
824 * to make fingerprinting harder. */
825 std::chrono::microseconds NextInvToInbounds(std::chrono::microseconds now,
826 std::chrono::seconds average_interval,
827 uint64_t network_key) EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex);
828 829 830 // All of the following cache a recent block, and are protected by m_most_recent_block_mutex
831 Mutex m_most_recent_block_mutex;
832 std::shared_ptr<const CBlock> m_most_recent_block GUARDED_BY(m_most_recent_block_mutex);
833 std::shared_ptr<const CBlockHeaderAndShortTxIDs> m_most_recent_compact_block GUARDED_BY(m_most_recent_block_mutex);
834 uint256 m_most_recent_block_hash GUARDED_BY(m_most_recent_block_mutex);
835 std::unique_ptr<const std::map<uint256, CTransactionRef>> m_most_recent_block_txs GUARDED_BY(m_most_recent_block_mutex);
836 837 // Data about the low-work headers synchronization, aggregated from all peers' HeadersSyncStates.
838 /** Mutex guarding the other m_headers_presync_* variables. */
839 Mutex m_headers_presync_mutex;
840 /** A type to represent statistics about a peer's low-work headers sync.
841 *
842 * - The first field is the total verified amount of work in that synchronization.
843 * - The second is:
844 * - nullopt: the sync is in REDOWNLOAD phase (phase 2).
845 * - {height, timestamp}: the sync has the specified tip height and block timestamp (phase 1).
846 */
847 using HeadersPresyncStats = std::pair<arith_uint256, std::optional<std::pair<int64_t, uint32_t>>>;
848 /** Statistics for all peers in low-work headers sync. */
849 std::map<NodeId, HeadersPresyncStats> m_headers_presync_stats GUARDED_BY(m_headers_presync_mutex) {};
850 /** The peer with the most-work entry in m_headers_presync_stats. */
851 NodeId m_headers_presync_bestpeer GUARDED_BY(m_headers_presync_mutex) {-1};
852 /** The m_headers_presync_stats improved, and needs signalling. */
853 std::atomic_bool m_headers_presync_should_signal{false};
854 855 /** Height of the highest block announced using BIP 152 high-bandwidth mode. */
856 int m_highest_fast_announce GUARDED_BY(::cs_main){0};
857 858 /** Have we requested this block from a peer */
859 bool IsBlockRequested(const uint256& hash) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
860 861 /** Have we requested this block from an outbound peer */
862 bool IsBlockRequestedFromOutbound(const uint256& hash) EXCLUSIVE_LOCKS_REQUIRED(cs_main, !m_peer_mutex);
863 864 /** Have we requested this block from a specific peer */
865 bool IsBlockRequestedFromPeer(const uint256& hash, NodeId peer) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
866 867 /** Remove this block from our tracked requested blocks. Called if:
868 * - the block has been received from a peer
869 * - the request for the block has timed out
870 * If "from_peer" is specified, then only remove the block if it is in
871 * flight from that peer (to avoid one peer's network traffic from
872 * affecting another's state).
873 */
874 void RemoveBlockRequest(const uint256& hash, std::optional<NodeId> from_peer) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
875 876 /* Mark a block as in flight
877 * Returns false, still setting pit, if the block was already in flight from the same peer
878 * pit will only be valid as long as the same cs_main lock is being held
879 */
880 bool BlockRequested(NodeId nodeid, const CBlockIndex& block, std::list<QueuedBlock>::iterator** pit = nullptr) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
881 882 bool TipMayBeStale() EXCLUSIVE_LOCKS_REQUIRED(cs_main);
883 884 /** Update pindexLastCommonBlock and add not-in-flight missing successors to vBlocks, until it has
885 * at most count entries.
886 */
887 void FindNextBlocksToDownload(const Peer& peer, unsigned int count, std::vector<const CBlockIndex*>& vBlocks, NodeId& nodeStaller) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
888 889 /** Request blocks for the background chainstate, if one is in use. */
890 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);
891 892 /**
893 * \brief Find next blocks to download from a peer after a starting block.
894 *
895 * \param vBlocks Vector of blocks to download which will be appended to.
896 * \param peer Peer which blocks will be downloaded from.
897 * \param state Pointer to the state of the peer.
898 * \param pindexWalk Pointer to the starting block to add to vBlocks.
899 * \param count Maximum number of blocks to allow in vBlocks. No more
900 * blocks will be added if it reaches this size.
901 * \param nWindowEnd Maximum height of blocks to allow in vBlocks. No
902 * blocks will be added above this height.
903 * \param activeChain Optional pointer to a chain to compare against. If
904 * provided, any next blocks which are already contained
905 * in this chain will not be appended to vBlocks, but
906 * instead will be used to update the
907 * state->pindexLastCommonBlock pointer.
908 * \param nodeStaller Optional pointer to a NodeId variable that will receive
909 * the ID of another peer that might be causing this peer
910 * to stall. This is set to the ID of the peer which
911 * first requested the first in-flight block in the
912 * download window. It is only set if vBlocks is empty at
913 * the end of this function call and if increasing
914 * nWindowEnd by 1 would cause it to be non-empty (which
915 * indicates the download might be stalled because every
916 * block in the window is in flight and no other peer is
917 * trying to download the next block).
918 */
919 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);
920 921 /* Multimap used to preserve insertion order */
922 typedef std::multimap<uint256, std::pair<NodeId, std::list<QueuedBlock>::iterator>> BlockDownloadMap;
923 BlockDownloadMap mapBlocksInFlight GUARDED_BY(cs_main);
924 925 /** When our tip was last updated. */
926 std::atomic<std::chrono::seconds> m_last_tip_update{0s};
927 928 /** Determine whether or not a peer can request a transaction, and return it (or nullptr if not found or not allowed). */
929 CTransactionRef FindTxForGetData(const Peer::TxRelay& tx_relay, const GenTxid& gtxid)
930 EXCLUSIVE_LOCKS_REQUIRED(!m_most_recent_block_mutex, NetEventsInterface::g_msgproc_mutex);
931 932 void ProcessGetData(CNode& pfrom, Peer& peer, const std::atomic<bool>& interruptMsgProc)
933 EXCLUSIVE_LOCKS_REQUIRED(!m_most_recent_block_mutex, peer.m_getdata_requests_mutex, NetEventsInterface::g_msgproc_mutex)
934 LOCKS_EXCLUDED(::cs_main);
935 936 /** Process a new block. Perform any post-processing housekeeping */
937 void ProcessBlock(CNode& node, const std::shared_ptr<const CBlock>& block, bool force_processing, bool min_pow_checked);
938 939 /** Process compact block txns */
940 void ProcessCompactBlockTxns(CNode& pfrom, Peer& peer, const BlockTransactions& block_transactions)
941 EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex, !m_most_recent_block_mutex);
942 943 /**
944 * When a peer sends us a valid block, instruct it to announce blocks to us
945 * using CMPCTBLOCK if possible by adding its nodeid to the end of
946 * lNodesAnnouncingHeaderAndIDs, and keeping that list under a certain size by
947 * removing the first element if necessary.
948 */
949 void MaybeSetPeerAsAnnouncingHeaderAndIDs(NodeId nodeid) EXCLUSIVE_LOCKS_REQUIRED(cs_main, !m_peer_mutex);
950 951 /** Stack of nodes which we have set to announce using compact blocks */
952 std::list<NodeId> lNodesAnnouncingHeaderAndIDs GUARDED_BY(cs_main);
953 954 /** Number of peers from which we're downloading blocks. */
955 int m_peers_downloading_from GUARDED_BY(cs_main) = 0;
956 957 void AddToCompactExtraTransactions(const CTransactionRef& tx, size_t tx_dynamic_usage) EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex);
958 959 /** Orphan/conflicted/etc transactions that are kept for compact block reconstruction.
960 * The last -blockreconstructionextratxn/DEFAULT_BLOCK_RECONSTRUCTION_EXTRA_TXN of
961 * these are kept in a ring buffer */
962 std::vector<CTransactionRef> vExtraTxnForCompact GUARDED_BY(g_msgproc_mutex);
963 /** Offset into vExtraTxnForCompact to insert the next tx */
964 size_t vExtraTxnForCompactIt GUARDED_BY(g_msgproc_mutex) = 0;
965 size_t blockreconstructionextratxn_memusage{0};
966 967 /** Check whether the last unknown block a peer advertised is not yet known. */
968 void ProcessBlockAvailability(NodeId nodeid) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
969 /** Update tracking information about which blocks a peer is assumed to have. */
970 void UpdateBlockAvailability(NodeId nodeid, const uint256& hash) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
971 bool CanDirectFetch() EXCLUSIVE_LOCKS_REQUIRED(cs_main);
972 973 /**
974 * Estimates the distance, in blocks, between the best-known block and the network chain tip.
975 * Utilizes the best-block time and the chainparams blocks spacing to approximate it.
976 */
977 int64_t ApproximateBestBlockDepth() const;
978 979 /**
980 * To prevent fingerprinting attacks, only send blocks/headers outside of
981 * the active chain if they are no more than a month older (both in time,
982 * and in best equivalent proof of work) than the best header chain we know
983 * about and we fully-validated them at some point.
984 */
985 bool BlockRequestAllowed(const CBlockIndex* pindex) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
986 bool AlreadyHaveBlock(const uint256& block_hash) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
987 void ProcessGetBlockData(CNode& pfrom, Peer& peer, const CInv& inv)
988 EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex, !m_most_recent_block_mutex);
989 990 /**
991 * Validation logic for compact filters request handling.
992 *
993 * May disconnect from the peer in the case of a bad request.
994 *
995 * @param[in] node The node that we received the request from
996 * @param[in] peer The peer that we received the request from
997 * @param[in] filter_type The filter type the request is for. Must be basic filters.
998 * @param[in] start_height The start height for the request
999 * @param[in] stop_hash The stop_hash for the request
1000 * @param[in] max_height_diff The maximum number of items permitted to request, as specified in BIP 157
1001 * @param[out] stop_index The CBlockIndex for the stop_hash block, if the request can be serviced.
1002 * @param[out] filter_index The filter index, if the request can be serviced.
1003 * @return True if the request can be serviced.
1004 */
1005 bool PrepareBlockFilterRequest(CNode& node, Peer& peer,
1006 BlockFilterType filter_type, uint32_t start_height,
1007 const uint256& stop_hash, uint32_t max_height_diff,
1008 const CBlockIndex*& stop_index,
1009 BlockFilterIndex*& filter_index);
1010 1011 /**
1012 * Handle a cfilters request.
1013 *
1014 * May disconnect from the peer in the case of a bad request.
1015 *
1016 * @param[in] node The node that we received the request from
1017 * @param[in] peer The peer that we received the request from
1018 * @param[in] vRecv The raw message received
1019 */
1020 void ProcessGetCFilters(CNode& node, Peer& peer, DataStream& vRecv);
1021 1022 /**
1023 * Handle a cfheaders request.
1024 *
1025 * May disconnect from the peer in the case of a bad request.
1026 *
1027 * @param[in] node The node that we received the request from
1028 * @param[in] peer The peer that we received the request from
1029 * @param[in] vRecv The raw message received
1030 */
1031 void ProcessGetCFHeaders(CNode& node, Peer& peer, DataStream& vRecv);
1032 1033 /**
1034 * Handle a getcfcheckpt request.
1035 *
1036 * May disconnect from the peer in the case of a bad request.
1037 *
1038 * @param[in] node The node that we received the request from
1039 * @param[in] peer The peer that we received the request from
1040 * @param[in] vRecv The raw message received
1041 */
1042 void ProcessGetCFCheckPt(CNode& node, Peer& peer, DataStream& vRecv);
1043 1044 /** Checks if address relay is permitted with peer. If needed, initializes
1045 * the m_addr_known bloom filter and sets m_addr_relay_enabled to true.
1046 *
1047 * @return True if address relay is enabled with peer
1048 * False if address relay is disallowed
1049 */
1050 bool SetupAddressRelay(const CNode& node, Peer& peer) EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex);
1051 1052 void AddAddressKnown(Peer& peer, const CAddress& addr) EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex);
1053 void PushAddress(Peer& peer, const CAddress& addr) EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex);
1054 };
1055 1056 const CNodeState* PeerManagerImpl::State(NodeId pnode) const
1057 {
1058 std::map<NodeId, CNodeState>::const_iterator it = m_node_states.find(pnode);
1059 if (it == m_node_states.end())
1060 return nullptr;
1061 return &it->second;
1062 }
1063 1064 CNodeState* PeerManagerImpl::State(NodeId pnode)
1065 {
1066 return const_cast<CNodeState*>(std::as_const(*this).State(pnode));
1067 }
1068 1069 /**
1070 * Whether the peer supports the address. For example, a peer that does not
1071 * implement BIP155 cannot receive Tor v3 addresses because it requires
1072 * ADDRv2 (BIP155) encoding.
1073 */
1074 static bool IsAddrCompatible(const Peer& peer, const CAddress& addr)
1075 {
1076 return peer.m_wants_addrv2 || addr.IsAddrV1Compatible();
1077 }
1078 1079 void PeerManagerImpl::AddAddressKnown(Peer& peer, const CAddress& addr)
1080 {
1081 assert(peer.m_addr_known);
1082 peer.m_addr_known->insert(addr.GetKey());
1083 }
1084 1085 void PeerManagerImpl::PushAddress(Peer& peer, const CAddress& addr)
1086 {
1087 // Known checking here is only to save space from duplicates.
1088 // Before sending, we'll filter it again for known addresses that were
1089 // added after addresses were pushed.
1090 assert(peer.m_addr_known);
1091 if (addr.IsValid() && !peer.m_addr_known->contains(addr.GetKey()) && IsAddrCompatible(peer, addr)) {
1092 if (peer.m_addrs_to_send.size() >= MAX_ADDR_TO_SEND) {
1093 peer.m_addrs_to_send[m_rng.randrange(peer.m_addrs_to_send.size())] = addr;
1094 } else {
1095 peer.m_addrs_to_send.push_back(addr);
1096 }
1097 }
1098 }
1099 1100 static void AddKnownTx(Peer& peer, const uint256& hash)
1101 {
1102 auto tx_relay = peer.GetTxRelay();
1103 if (!tx_relay) return;
1104 1105 LOCK(tx_relay->m_tx_inventory_mutex);
1106 tx_relay->m_tx_inventory_known_filter.insert(hash);
1107 }
1108 1109 /** Whether this peer can serve us blocks. */
1110 static bool CanServeBlocks(const Peer& peer)
1111 {
1112 return peer.m_their_services & (NODE_NETWORK|NODE_NETWORK_LIMITED);
1113 }
1114 1115 /** Whether this peer can only serve limited recent blocks (e.g. because
1116 * it prunes old blocks) */
1117 static bool IsLimitedPeer(const Peer& peer)
1118 {
1119 return (!(peer.m_their_services & NODE_NETWORK) &&
1120 (peer.m_their_services & NODE_NETWORK_LIMITED));
1121 }
1122 1123 /** Whether this peer can serve us witness data */
1124 static bool CanServeWitnesses(const Peer& peer)
1125 {
1126 return peer.m_their_services & NODE_WITNESS;
1127 }
1128 1129 std::chrono::microseconds PeerManagerImpl::NextInvToInbounds(std::chrono::microseconds now,
1130 std::chrono::seconds average_interval,
1131 uint64_t network_key)
1132 {
1133 auto [it, inserted] = m_next_inv_to_inbounds_per_network_key.try_emplace(network_key, 0us);
1134 auto& timer{it->second};
1135 if (timer < now) {
1136 timer = now + m_rng.rand_exp_duration(average_interval);
1137 }
1138 return timer;
1139 }
1140 1141 bool PeerManagerImpl::IsBlockRequested(const uint256& hash)
1142 {
1143 return mapBlocksInFlight.count(hash);
1144 }
1145 1146 bool PeerManagerImpl::IsBlockRequestedFromOutbound(const uint256& hash)
1147 {
1148 for (auto range = mapBlocksInFlight.equal_range(hash); range.first != range.second; range.first++) {
1149 auto [nodeid, block_it] = range.first->second;
1150 PeerRef peer{GetPeerRef(nodeid)};
1151 if (peer && !peer->m_is_inbound) return true;
1152 }
1153 1154 return false;
1155 }
1156 1157 bool PeerManagerImpl::IsBlockRequestedFromPeer(const uint256& hash, NodeId peer)
1158 {
1159 for (auto range = mapBlocksInFlight.equal_range(hash); range.first != range.second; range.first++) {
1160 auto [nodeid, block_it] = range.first->second;
1161 if (nodeid == peer) return true;
1162 }
1163 1164 return false;
1165 }
1166 1167 void PeerManagerImpl::RemoveBlockRequest(const uint256& hash, std::optional<NodeId> from_peer)
1168 {
1169 auto range = mapBlocksInFlight.equal_range(hash);
1170 if (range.first == range.second) {
1171 // Block was not requested from any peer
1172 return;
1173 }
1174 1175 // We should not have requested too many of this block
1176 Assume(mapBlocksInFlight.count(hash) <= MAX_CMPCTBLOCKS_INFLIGHT_PER_BLOCK);
1177 1178 while (range.first != range.second) {
1179 auto [node_id, list_it] = range.first->second;
1180 1181 if (from_peer && *from_peer != node_id) {
1182 range.first++;
1183 continue;
1184 }
1185 1186 CNodeState& state = *Assert(State(node_id));
1187 1188 if (state.vBlocksInFlight.begin() == list_it) {
1189 // First block on the queue was received, update the start download time for the next one
1190 state.m_downloading_since = std::max(state.m_downloading_since, GetTime<std::chrono::microseconds>());
1191 }
1192 state.vBlocksInFlight.erase(list_it);
1193 1194 if (state.vBlocksInFlight.empty()) {
1195 // Last validated block on the queue for this peer was received.
1196 m_peers_downloading_from--;
1197 }
1198 state.m_stalling_since = 0us;
1199 1200 range.first = mapBlocksInFlight.erase(range.first);
1201 }
1202 }
1203 1204 bool PeerManagerImpl::BlockRequested(NodeId nodeid, const CBlockIndex& block, std::list<QueuedBlock>::iterator** pit)
1205 {
1206 const uint256& hash{block.GetBlockHash()};
1207 1208 CNodeState *state = State(nodeid);
1209 assert(state != nullptr);
1210 1211 Assume(mapBlocksInFlight.count(hash) <= MAX_CMPCTBLOCKS_INFLIGHT_PER_BLOCK);
1212 1213 // Short-circuit most stuff in case it is from the same node
1214 for (auto range = mapBlocksInFlight.equal_range(hash); range.first != range.second; range.first++) {
1215 if (range.first->second.first == nodeid) {
1216 if (pit) {
1217 *pit = &range.first->second.second;
1218 }
1219 return false;
1220 }
1221 }
1222 1223 // Make sure it's not being fetched already from same peer.
1224 RemoveBlockRequest(hash, nodeid);
1225 1226 std::list<QueuedBlock>::iterator it = state->vBlocksInFlight.insert(state->vBlocksInFlight.end(),
1227 {&block, std::unique_ptr<PartiallyDownloadedBlock>(pit ? new PartiallyDownloadedBlock(&m_mempool) : nullptr)});
1228 if (state->vBlocksInFlight.size() == 1) {
1229 // We're starting a block download (batch) from this peer.
1230 state->m_downloading_since = GetTime<std::chrono::microseconds>();
1231 m_peers_downloading_from++;
1232 }
1233 auto itInFlight = mapBlocksInFlight.insert(std::make_pair(hash, std::make_pair(nodeid, it)));
1234 if (pit) {
1235 *pit = &itInFlight->second.second;
1236 }
1237 return true;
1238 }
1239 1240 void PeerManagerImpl::MaybeSetPeerAsAnnouncingHeaderAndIDs(NodeId nodeid)
1241 {
1242 AssertLockHeld(cs_main);
1243 1244 // When in -blocksonly mode, never request high-bandwidth mode from peers. Our
1245 // mempool will not contain the transactions necessary to reconstruct the
1246 // compact block.
1247 if (m_opts.ignore_incoming_txs) return;
1248 1249 CNodeState* nodestate = State(nodeid);
1250 PeerRef peer{GetPeerRef(nodeid)};
1251 if (!nodestate || !nodestate->m_provides_cmpctblocks) {
1252 // Don't request compact blocks if the peer has not signalled support
1253 return;
1254 }
1255 1256 int num_outbound_hb_peers = 0;
1257 for (std::list<NodeId>::iterator it = lNodesAnnouncingHeaderAndIDs.begin(); it != lNodesAnnouncingHeaderAndIDs.end(); it++) {
1258 if (*it == nodeid) {
1259 lNodesAnnouncingHeaderAndIDs.erase(it);
1260 lNodesAnnouncingHeaderAndIDs.push_back(nodeid);
1261 return;
1262 }
1263 PeerRef peer_ref{GetPeerRef(*it)};
1264 if (peer_ref && !peer_ref->m_is_inbound) ++num_outbound_hb_peers;
1265 }
1266 if (peer && peer->m_is_inbound) {
1267 // If we're adding an inbound HB peer, make sure we're not removing
1268 // our last outbound HB peer in the process.
1269 if (lNodesAnnouncingHeaderAndIDs.size() >= 3 && num_outbound_hb_peers == 1) {
1270 PeerRef remove_peer{GetPeerRef(lNodesAnnouncingHeaderAndIDs.front())};
1271 if (remove_peer && !remove_peer->m_is_inbound) {
1272 // Put the HB outbound peer in the second slot, so that it
1273 // doesn't get removed.
1274 std::swap(lNodesAnnouncingHeaderAndIDs.front(), *std::next(lNodesAnnouncingHeaderAndIDs.begin()));
1275 }
1276 }
1277 }
1278 m_connman.ForNode(nodeid, [this](CNode* pfrom) EXCLUSIVE_LOCKS_REQUIRED(::cs_main) {
1279 AssertLockHeld(::cs_main);
1280 if (lNodesAnnouncingHeaderAndIDs.size() >= 3) {
1281 // As per BIP152, we only get 3 of our peers to announce
1282 // blocks using compact encodings.
1283 m_connman.ForNode(lNodesAnnouncingHeaderAndIDs.front(), [this](CNode* pnodeStop){
1284 MakeAndPushMessage(*pnodeStop, NetMsgType::SENDCMPCT, /*high_bandwidth=*/false, /*version=*/CMPCTBLOCKS_VERSION);
1285 // save BIP152 bandwidth state: we select peer to be low-bandwidth
1286 pnodeStop->m_bip152_highbandwidth_to = false;
1287 return true;
1288 });
1289 lNodesAnnouncingHeaderAndIDs.pop_front();
1290 }
1291 MakeAndPushMessage(*pfrom, NetMsgType::SENDCMPCT, /*high_bandwidth=*/true, /*version=*/CMPCTBLOCKS_VERSION);
1292 // save BIP152 bandwidth state: we select peer to be high-bandwidth
1293 pfrom->m_bip152_highbandwidth_to = true;
1294 lNodesAnnouncingHeaderAndIDs.push_back(pfrom->GetId());
1295 return true;
1296 });
1297 }
1298 1299 bool PeerManagerImpl::TipMayBeStale()
1300 {
1301 AssertLockHeld(cs_main);
1302 const Consensus::Params& consensusParams = m_chainparams.GetConsensus();
1303 if (m_last_tip_update.load() == 0s) {
1304 m_last_tip_update = GetTime<std::chrono::seconds>();
1305 }
1306 return m_last_tip_update.load() < GetTime<std::chrono::seconds>() - std::chrono::seconds{consensusParams.nPowTargetSpacing * 3} && mapBlocksInFlight.empty();
1307 }
1308 1309 int64_t PeerManagerImpl::ApproximateBestBlockDepth() const
1310 {
1311 return (GetTime<std::chrono::seconds>() - m_best_block_time.load()).count() / m_chainparams.GetConsensus().nPowTargetSpacing;
1312 }
1313 1314 bool PeerManagerImpl::CanDirectFetch()
1315 {
1316 return m_chainman.ActiveChain().Tip()->Time() > NodeClock::now() - m_chainparams.GetConsensus().PowTargetSpacing() * 20;
1317 }
1318 1319 static bool PeerHasHeader(CNodeState *state, const CBlockIndex *pindex) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
1320 {
1321 if (state->pindexBestKnownBlock && pindex == state->pindexBestKnownBlock->GetAncestor(pindex->nHeight))
1322 return true;
1323 if (state->pindexBestHeaderSent && pindex == state->pindexBestHeaderSent->GetAncestor(pindex->nHeight))
1324 return true;
1325 return false;
1326 }
1327 1328 void PeerManagerImpl::ProcessBlockAvailability(NodeId nodeid) {
1329 CNodeState *state = State(nodeid);
1330 assert(state != nullptr);
1331 1332 if (!state->hashLastUnknownBlock.IsNull()) {
1333 const CBlockIndex* pindex = m_chainman.m_blockman.LookupBlockIndex(state->hashLastUnknownBlock);
1334 if (pindex && pindex->nChainWork > 0) {
1335 if (state->pindexBestKnownBlock == nullptr || pindex->nChainWork >= state->pindexBestKnownBlock->nChainWork) {
1336 state->pindexBestKnownBlock = pindex;
1337 }
1338 state->hashLastUnknownBlock.SetNull();
1339 }
1340 }
1341 }
1342 1343 void PeerManagerImpl::UpdateBlockAvailability(NodeId nodeid, const uint256 &hash) {
1344 CNodeState *state = State(nodeid);
1345 assert(state != nullptr);
1346 1347 ProcessBlockAvailability(nodeid);
1348 1349 const CBlockIndex* pindex = m_chainman.m_blockman.LookupBlockIndex(hash);
1350 if (pindex && pindex->nChainWork > 0) {
1351 // An actually better block was announced.
1352 if (state->pindexBestKnownBlock == nullptr || pindex->nChainWork >= state->pindexBestKnownBlock->nChainWork) {
1353 state->pindexBestKnownBlock = pindex;
1354 }
1355 } else {
1356 // An unknown block was announced; just assume that the latest one is the best one.
1357 state->hashLastUnknownBlock = hash;
1358 }
1359 }
1360 1361 // Logic for calculating which blocks to download from a given peer, given our current tip.
1362 void PeerManagerImpl::FindNextBlocksToDownload(const Peer& peer, unsigned int count, std::vector<const CBlockIndex*>& vBlocks, NodeId& nodeStaller)
1363 {
1364 if (count == 0)
1365 return;
1366 1367 vBlocks.reserve(vBlocks.size() + count);
1368 CNodeState *state = State(peer.m_id);
1369 assert(state != nullptr);
1370 1371 // Make sure pindexBestKnownBlock is up to date, we'll need it.
1372 ProcessBlockAvailability(peer.m_id);
1373 1374 if (state->pindexBestKnownBlock == nullptr || state->pindexBestKnownBlock->nChainWork < m_chainman.ActiveChain().Tip()->nChainWork || state->pindexBestKnownBlock->nChainWork < m_chainman.MinimumChainWork()) {
1375 // This peer has nothing interesting.
1376 return;
1377 }
1378 1379 // When we sync with AssumeUtxo and discover the snapshot is not in the peer's best chain, abort:
1380 // We can't reorg to this chain due to missing undo data until the background sync has finished,
1381 // so downloading blocks from it would be futile.
1382 const CBlockIndex* snap_base{m_chainman.GetSnapshotBaseBlock()};
1383 if (snap_base && state->pindexBestKnownBlock->GetAncestor(snap_base->nHeight) != snap_base) {
1384 LogDebug(BCLog::NET, "Not downloading blocks from peer=%d, which doesn't have the snapshot block in its best chain.\n", peer.m_id);
1385 return;
1386 }
1387 1388 // Bootstrap quickly by guessing a parent of our best tip is the forking point.
1389 // Guessing wrong in either direction is not a problem.
1390 // Also reset pindexLastCommonBlock after a snapshot was loaded, so that blocks after the snapshot will be prioritised for download.
1391 if (state->pindexLastCommonBlock == nullptr ||
1392 (snap_base && state->pindexLastCommonBlock->nHeight < snap_base->nHeight)) {
1393 state->pindexLastCommonBlock = m_chainman.ActiveChain()[std::min(state->pindexBestKnownBlock->nHeight, m_chainman.ActiveChain().Height())];
1394 }
1395 1396 // If the peer reorganized, our previous pindexLastCommonBlock may not be an ancestor
1397 // of its current tip anymore. Go back enough to fix that.
1398 state->pindexLastCommonBlock = LastCommonAncestor(state->pindexLastCommonBlock, state->pindexBestKnownBlock);
1399 if (state->pindexLastCommonBlock == state->pindexBestKnownBlock)
1400 return;
1401 1402 const CBlockIndex *pindexWalk = state->pindexLastCommonBlock;
1403 // Never fetch further than the best block we know the peer has, or more than BLOCK_DOWNLOAD_WINDOW + 1 beyond the last
1404 // linked block we have in common with this peer. The +1 is so we can detect stalling, namely if we would be able to
1405 // download that next block if the window were 1 larger.
1406 int nWindowEnd = state->pindexLastCommonBlock->nHeight + BLOCK_DOWNLOAD_WINDOW;
1407 1408 FindNextBlocks(vBlocks, peer, state, pindexWalk, count, nWindowEnd, &m_chainman.ActiveChain(), &nodeStaller);
1409 }
1410 1411 void PeerManagerImpl::TryDownloadingHistoricalBlocks(const Peer& peer, unsigned int count, std::vector<const CBlockIndex*>& vBlocks, const CBlockIndex *from_tip, const CBlockIndex* target_block)
1412 {
1413 Assert(from_tip);
1414 Assert(target_block);
1415 1416 if (vBlocks.size() >= count) {
1417 return;
1418 }
1419 1420 vBlocks.reserve(count);
1421 CNodeState *state = Assert(State(peer.m_id));
1422 1423 if (state->pindexBestKnownBlock == nullptr || state->pindexBestKnownBlock->GetAncestor(target_block->nHeight) != target_block) {
1424 // This peer can't provide us the complete series of blocks leading up to the
1425 // assumeutxo snapshot base.
1426 //
1427 // Presumably this peer's chain has less work than our ActiveChain()'s tip, or else we
1428 // will eventually crash when we try to reorg to it. Let other logic
1429 // deal with whether we disconnect this peer.
1430 //
1431 // TODO at some point in the future, we might choose to request what blocks
1432 // this peer does have from the historical chain, despite it not having a
1433 // complete history beneath the snapshot base.
1434 return;
1435 }
1436 1437 FindNextBlocks(vBlocks, peer, state, from_tip, count, std::min<int>(from_tip->nHeight + BLOCK_DOWNLOAD_WINDOW, target_block->nHeight));
1438 }
1439 1440 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)
1441 {
1442 std::vector<const CBlockIndex*> vToFetch;
1443 int nMaxHeight = std::min<int>(state->pindexBestKnownBlock->nHeight, nWindowEnd + 1);
1444 bool is_limited_peer = IsLimitedPeer(peer);
1445 NodeId waitingfor = -1;
1446 while (pindexWalk->nHeight < nMaxHeight) {
1447 // Read up to 128 (or more, if more blocks than that are needed) successors of pindexWalk (towards
1448 // pindexBestKnownBlock) into vToFetch. We fetch 128, because CBlockIndex::GetAncestor may be as expensive
1449 // as iterating over ~100 CBlockIndex* entries anyway.
1450 int nToFetch = std::min(nMaxHeight - pindexWalk->nHeight, std::max<int>(count - vBlocks.size(), 128));
1451 vToFetch.resize(nToFetch);
1452 pindexWalk = state->pindexBestKnownBlock->GetAncestor(pindexWalk->nHeight + nToFetch);
1453 vToFetch[nToFetch - 1] = pindexWalk;
1454 for (unsigned int i = nToFetch - 1; i > 0; i--) {
1455 vToFetch[i - 1] = vToFetch[i]->pprev;
1456 }
1457 1458 // Iterate over those blocks in vToFetch (in forward direction), adding the ones that
1459 // are not yet downloaded and not in flight to vBlocks. In the meantime, update
1460 // pindexLastCommonBlock as long as all ancestors are already downloaded, or if it's
1461 // already part of our chain (and therefore don't need it even if pruned).
1462 for (const CBlockIndex* pindex : vToFetch) {
1463 if (!pindex->IsValid(BLOCK_VALID_TREE)) {
1464 // We consider the chain that this peer is on invalid.
1465 return;
1466 }
1467 1468 if (!CanServeWitnesses(peer) && DeploymentActiveAt(*pindex, m_chainman, Consensus::DEPLOYMENT_SEGWIT)) {
1469 // We wouldn't download this block or its descendants from this peer.
1470 return;
1471 }
1472 1473 if (pindex->nStatus & BLOCK_HAVE_DATA || (activeChain && activeChain->Contains(pindex))) {
1474 if (activeChain && pindex->HaveNumChainTxs()) {
1475 state->pindexLastCommonBlock = pindex;
1476 }
1477 continue;
1478 }
1479 1480 // Is block in-flight?
1481 if (IsBlockRequested(pindex->GetBlockHash())) {
1482 if (waitingfor == -1) {
1483 // This is the first already-in-flight block.
1484 waitingfor = mapBlocksInFlight.lower_bound(pindex->GetBlockHash())->second.first;
1485 }
1486 continue;
1487 }
1488 1489 // The block is not already downloaded, and not yet in flight.
1490 if (pindex->nHeight > nWindowEnd) {
1491 // We reached the end of the window.
1492 if (vBlocks.size() == 0 && waitingfor != peer.m_id) {
1493 // We aren't able to fetch anything, but we would be if the download window was one larger.
1494 if (nodeStaller) *nodeStaller = waitingfor;
1495 }
1496 return;
1497 }
1498 1499 // Don't request blocks that go further than what limited peers can provide
1500 if (is_limited_peer && (state->pindexBestKnownBlock->nHeight - pindex->nHeight >= static_cast<int>(NODE_NETWORK_LIMITED_MIN_BLOCKS) - 2 /* two blocks buffer for possible races */)) {
1501 continue;
1502 }
1503 1504 vBlocks.push_back(pindex);
1505 if (vBlocks.size() == count) {
1506 return;
1507 }
1508 }
1509 }
1510 }
1511 1512 } // namespace
1513 1514 void PeerManagerImpl::PushNodeVersion(CNode& pnode, const Peer& peer)
1515 {
1516 uint64_t my_services{peer.m_our_services};
1517 const int64_t nTime{count_seconds(GetTime<std::chrono::seconds>())};
1518 uint64_t nonce = pnode.GetLocalNonce();
1519 const int nNodeStartingHeight{m_best_height};
1520 NodeId nodeid = pnode.GetId();
1521 CAddress addr = pnode.addr;
1522 1523 CService addr_you = addr.IsRoutable() && !IsProxy(addr) && addr.IsAddrV1Compatible() ? addr : CService();
1524 uint64_t your_services{addr.nServices};
1525 1526 const bool tx_relay{!RejectIncomingTxs(pnode)};
1527 MakeAndPushMessage(pnode, NetMsgType::VERSION, PROTOCOL_VERSION, my_services, nTime,
1528 your_services, CNetAddr::V1(addr_you), // Together the pre-version-31402 serialization of CAddress "addrYou" (without nTime)
1529 my_services, CNetAddr::V1(CService{}), // Together the pre-version-31402 serialization of CAddress "addrMe" (without nTime)
1530 nonce, strSubVersion, nNodeStartingHeight, tx_relay);
1531 1532 if (fLogIPs) {
1533 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);
1534 } else {
1535 LogDebug(BCLog::NET, "send version message: version %d, blocks=%d, txrelay=%d, peer=%d\n", PROTOCOL_VERSION, nNodeStartingHeight, tx_relay, nodeid);
1536 }
1537 }
1538 1539 void PeerManagerImpl::UpdateLastBlockAnnounceTime(NodeId node, int64_t time_in_seconds)
1540 {
1541 LOCK(cs_main);
1542 CNodeState *state = State(node);
1543 if (state) state->m_last_block_announcement = time_in_seconds;
1544 }
1545 1546 void PeerManagerImpl::InitializeNode(const CNode& node, ServiceFlags our_services)
1547 {
1548 NodeId nodeid = node.GetId();
1549 {
1550 LOCK(cs_main); // For m_node_states
1551 m_node_states.try_emplace(m_node_states.end(), nodeid);
1552 }
1553 WITH_LOCK(m_tx_download_mutex, m_txdownloadman.CheckIsEmpty(nodeid));
1554 1555 if (NetPermissions::HasFlag(node.m_permission_flags, NetPermissionFlags::BloomFilter)) {
1556 our_services = static_cast<ServiceFlags>(our_services | NODE_BLOOM);
1557 }
1558 if (NetPermissions::HasFlag(node.m_permission_flags, NetPermissionFlags::BlockFilters)) {
1559 our_services = static_cast<ServiceFlags>(our_services | NODE_COMPACT_FILTERS);
1560 }
1561 1562 PeerRef peer = std::make_shared<Peer>(nodeid, our_services, node.IsInboundConn());
1563 {
1564 LOCK(m_peer_mutex);
1565 m_peer_map.emplace_hint(m_peer_map.end(), nodeid, peer);
1566 }
1567 }
1568 1569 void PeerManagerImpl::ReattemptInitialBroadcast(CScheduler& scheduler)
1570 {
1571 std::set<uint256> unbroadcast_txids = m_mempool.GetUnbroadcastTxs();
1572 1573 for (const auto& txid : unbroadcast_txids) {
1574 CTransactionRef tx = m_mempool.get(txid);
1575 1576 if (tx != nullptr) {
1577 RelayTransaction(txid, tx->GetWitnessHash());
1578 } else {
1579 m_mempool.RemoveUnbroadcastTx(txid, true);
1580 }
1581 }
1582 1583 // Schedule next run for 10-15 minutes in the future.
1584 // We add randomness on every cycle to avoid the possibility of P2P fingerprinting.
1585 const auto delta = 10min + FastRandomContext().randrange<std::chrono::milliseconds>(5min);
1586 scheduler.scheduleFromNow([&] { ReattemptInitialBroadcast(scheduler); }, delta);
1587 }
1588 1589 void PeerManagerImpl::FinalizeNode(const CNode& node)
1590 {
1591 NodeId nodeid = node.GetId();
1592 {
1593 LOCK(cs_main);
1594 {
1595 // We remove the PeerRef from g_peer_map here, but we don't always
1596 // destruct the Peer. Sometimes another thread is still holding a
1597 // PeerRef, so the refcount is >= 1. Be careful not to do any
1598 // processing here that assumes Peer won't be changed before it's
1599 // destructed.
1600 PeerRef peer = RemovePeer(nodeid);
1601 assert(peer != nullptr);
1602 m_wtxid_relay_peers -= peer->m_wtxid_relay;
1603 assert(m_wtxid_relay_peers >= 0);
1604 // Decrement non-BIP110 counter if this was a non-BIP110 outbound peer
1605 if (node.m_is_non_bip110_outbound) {
1606 assert(m_num_non_bip110_outbound > 0);
1607 --m_num_non_bip110_outbound;
1608 }
1609 }
1610 CNodeState *state = State(nodeid);
1611 assert(state != nullptr);
1612 1613 if (state->fSyncStarted)
1614 nSyncStarted--;
1615 1616 for (const QueuedBlock& entry : state->vBlocksInFlight) {
1617 auto range = mapBlocksInFlight.equal_range(entry.pindex->GetBlockHash());
1618 while (range.first != range.second) {
1619 auto [node_id, list_it] = range.first->second;
1620 if (node_id != nodeid) {
1621 range.first++;
1622 } else {
1623 range.first = mapBlocksInFlight.erase(range.first);
1624 }
1625 }
1626 }
1627 {
1628 LOCK(m_tx_download_mutex);
1629 m_txdownloadman.DisconnectedPeer(nodeid);
1630 }
1631 if (m_txreconciliation) m_txreconciliation->ForgetPeer(nodeid);
1632 m_num_preferred_download_peers -= state->fPreferredDownload;
1633 m_peers_downloading_from -= (!state->vBlocksInFlight.empty());
1634 assert(m_peers_downloading_from >= 0);
1635 m_outbound_peers_with_protect_from_disconnect -= state->m_chain_sync.m_protect;
1636 assert(m_outbound_peers_with_protect_from_disconnect >= 0);
1637 1638 m_node_states.erase(nodeid);
1639 1640 if (m_node_states.empty()) {
1641 // Do a consistency check after the last peer is removed.
1642 assert(mapBlocksInFlight.empty());
1643 assert(m_num_preferred_download_peers == 0);
1644 assert(m_peers_downloading_from == 0);
1645 assert(m_outbound_peers_with_protect_from_disconnect == 0);
1646 assert(m_wtxid_relay_peers == 0);
1647 WITH_LOCK(m_tx_download_mutex, m_txdownloadman.CheckIsEmpty());
1648 }
1649 } // cs_main
1650 if (node.fSuccessfullyConnected &&
1651 !node.IsBlockOnlyConn() && !node.IsInboundConn()) {
1652 // Only change visible addrman state for full outbound peers. We don't
1653 // call Connected() for feeler connections since they don't have
1654 // fSuccessfullyConnected set.
1655 m_addrman.Connected(node.addr);
1656 }
1657 {
1658 LOCK(m_headers_presync_mutex);
1659 m_headers_presync_stats.erase(nodeid);
1660 }
1661 LogDebug(BCLog::NET, "Cleared nodestate for peer=%d\n", nodeid);
1662 }
1663 1664 bool PeerManagerImpl::HasAllDesirableServiceFlags(ServiceFlags services) const
1665 {
1666 // Shortcut for (services & GetDesirableServiceFlags(services)) == GetDesirableServiceFlags(services)
1667 return !(GetDesirableServiceFlags(services) & (~services));
1668 }
1669 1670 ServiceFlags PeerManagerImpl::GetDesirableServiceFlags(ServiceFlags services) const
1671 {
1672 if (services & NODE_NETWORK_LIMITED) {
1673 // Limited peers are desirable when we are close to the tip.
1674 if (ApproximateBestBlockDepth() < NODE_NETWORK_LIMITED_ALLOW_CONN_BLOCKS) {
1675 return ServiceFlags(NODE_NETWORK_LIMITED | NODE_WITNESS);
1676 }
1677 }
1678 return ServiceFlags(NODE_NETWORK | NODE_WITNESS);
1679 }
1680 1681 PeerRef PeerManagerImpl::GetPeerRef(NodeId id) const
1682 {
1683 LOCK(m_peer_mutex);
1684 auto it = m_peer_map.find(id);
1685 return it != m_peer_map.end() ? it->second : nullptr;
1686 }
1687 1688 PeerRef PeerManagerImpl::RemovePeer(NodeId id)
1689 {
1690 PeerRef ret;
1691 LOCK(m_peer_mutex);
1692 auto it = m_peer_map.find(id);
1693 if (it != m_peer_map.end()) {
1694 ret = std::move(it->second);
1695 m_peer_map.erase(it);
1696 }
1697 return ret;
1698 }
1699 1700 int PeerManagerImpl::GetNumberOfPeersWithValidatedDownloads() const
1701 {
1702 AssertLockHeld(m_chainman.GetMutex());
1703 return m_peers_downloading_from;
1704 }
1705 1706 bool PeerManagerImpl::GetNodeStateStats(NodeId nodeid, CNodeStateStats& stats) const
1707 {
1708 {
1709 LOCK(cs_main);
1710 const CNodeState* state = State(nodeid);
1711 if (state == nullptr)
1712 return false;
1713 stats.nSyncHeight = state->pindexBestKnownBlock ? state->pindexBestKnownBlock->nHeight : -1;
1714 stats.nCommonHeight = state->pindexLastCommonBlock ? state->pindexLastCommonBlock->nHeight : -1;
1715 for (const QueuedBlock& queue : state->vBlocksInFlight) {
1716 if (queue.pindex)
1717 stats.vHeightInFlight.push_back(queue.pindex->nHeight);
1718 }
1719 stats.m_last_block_announcement = NodeSeconds{std::chrono::seconds{state->m_last_block_announcement}};
1720 }
1721 1722 PeerRef peer = GetPeerRef(nodeid);
1723 if (peer == nullptr) return false;
1724 stats.their_services = peer->m_their_services;
1725 stats.m_starting_height = peer->m_starting_height;
1726 // It is common for nodes with good ping times to suddenly become lagged,
1727 // due to a new block arriving or other large transfer.
1728 // Merely reporting pingtime might fool the caller into thinking the node was still responsive,
1729 // since pingtime does not update until the ping is complete, which might take a while.
1730 // So, if a ping is taking an unusually long time in flight,
1731 // the caller can immediately detect that this is happening.
1732 auto ping_wait{0us};
1733 if ((0 != peer->m_ping_nonce_sent) && (0 != peer->m_ping_start.load().count())) {
1734 ping_wait = GetTime<std::chrono::microseconds>() - peer->m_ping_start.load();
1735 }
1736 1737 if (auto tx_relay = peer->GetTxRelay(); tx_relay != nullptr) {
1738 stats.m_relay_txs = WITH_LOCK(tx_relay->m_bloom_filter_mutex, return tx_relay->m_relay_txs);
1739 stats.m_fee_filter_received = tx_relay->m_fee_filter_received.load();
1740 } else {
1741 stats.m_relay_txs = false;
1742 stats.m_fee_filter_received = 0;
1743 }
1744 1745 stats.m_ping_wait = ping_wait;
1746 stats.m_addr_processed = peer->m_addr_processed.load();
1747 stats.m_addr_rate_limited = peer->m_addr_rate_limited.load();
1748 stats.m_addr_relay_enabled = peer->m_addr_relay_enabled.load();
1749 {
1750 LOCK(peer->m_headers_sync_mutex);
1751 if (peer->m_headers_sync) {
1752 stats.presync_height = peer->m_headers_sync->GetPresyncHeight();
1753 }
1754 }
1755 stats.time_offset = peer->m_time_offset;
1756 stats.m_misbehavior_score = WITH_LOCK(peer->m_misbehavior_mutex, return peer->m_should_discourage) ? 100 : 0;
1757 1758 return true;
1759 }
1760 1761 std::vector<TxOrphanage::OrphanTxBase> PeerManagerImpl::GetOrphanTransactions()
1762 {
1763 LOCK(m_tx_download_mutex);
1764 return m_txdownloadman.GetOrphanTransactions();
1765 }
1766 1767 PeerManagerInfo PeerManagerImpl::GetInfo() const
1768 {
1769 return PeerManagerInfo{
1770 .median_outbound_time_offset = m_outbound_time_offsets.Median(),
1771 .ignores_incoming_txs = m_opts.ignore_incoming_txs,
1772 };
1773 }
1774 1775 void PeerManagerImpl::LimitOrphanTxSize(uint32_t nMaxOrphans)
1776 {
1777 LOCK(g_msgproc_mutex);
1778 LOCK2(cs_main, m_tx_download_mutex);
1779 m_txdownloadman.SetMaxOrphanTxs(nMaxOrphans);
1780 }
1781 1782 void PeerManagerImpl::AddToCompactExtraTransactions(const CTransactionRef& tx, const size_t tx_dynamic_usage)
1783 {
1784 if (m_opts.max_extra_txs <= 0)
1785 return;
1786 if (!vExtraTxnForCompact.size())
1787 vExtraTxnForCompact.resize(m_opts.max_extra_txs);
1788 1789 {
1790 auto& entry = vExtraTxnForCompact[vExtraTxnForCompactIt];
1791 if (entry) blockreconstructionextratxn_memusage -= RecursiveDynamicUsage(*entry);
1792 entry = tx;
1793 blockreconstructionextratxn_memusage += tx_dynamic_usage;
1794 }
1795 vExtraTxnForCompactIt = (vExtraTxnForCompactIt + 1) % m_opts.max_extra_txs;
1796 1797 while (blockreconstructionextratxn_memusage > m_opts.max_extra_txs_size) {
1798 auto& entry = vExtraTxnForCompact[vExtraTxnForCompactIt];
1799 if (entry) blockreconstructionextratxn_memusage -= RecursiveDynamicUsage(*entry);
1800 entry.reset();
1801 vExtraTxnForCompactIt = (vExtraTxnForCompactIt + 1) % m_opts.max_extra_txs;
1802 }
1803 }
1804 1805 void PeerManagerImpl::Misbehaving(Peer& peer, const std::string& message)
1806 {
1807 LOCK(peer.m_misbehavior_mutex);
1808 1809 const std::string message_prefixed = message.empty() ? "" : (": " + message);
1810 peer.m_should_discourage = true;
1811 LogDebug(BCLog::NET, "Misbehaving: peer=%d%s\n", peer.m_id, message_prefixed);
1812 TRACEPOINT(net, misbehaving_connection,
1813 peer.m_id,
1814 message.c_str()
1815 );
1816 }
1817 1818 static void HandleDoSPunishment(CConnman& connman, NodeId node_id, const int nDoS, const char * const what_is_it) {
1819 // We never actually DoS ban for invalid blocks, merely disconnect nodes if we're relying on them as a primary node
1820 const std::string msg = strprintf("peer=%d got DoS score %d on invalid %s", node_id, nDoS, what_is_it);
1821 connman.ForNode(node_id, [msg](CNode* node) {
1822 if (node->PunishInvalidBlocks()) {
1823 LogDebug(BCLog::NET, "%s; simply disconnecting\n", msg);
1824 node->fDisconnect = true;
1825 } else {
1826 LogDebug(BCLog::NET, "%s; tolerating\n", msg);
1827 }
1828 return true;
1829 });
1830 }
1831 1832 void PeerManagerImpl::MaybePunishNodeForBlock(NodeId nodeid, const BlockValidationState& state,
1833 bool via_compact_block, const std::string& message)
1834 {
1835 switch (state.GetResult()) {
1836 case BlockValidationResult::BLOCK_RESULT_UNSET:
1837 break;
1838 case BlockValidationResult::BLOCK_HEADER_LOW_WORK:
1839 // We didn't try to process the block because the header chain may have
1840 // too little work.
1841 break;
1842 // The node is providing invalid data:
1843 case BlockValidationResult::BLOCK_CONSENSUS:
1844 case BlockValidationResult::BLOCK_MUTATED:
1845 if (!via_compact_block) {
1846 HandleDoSPunishment(m_connman, nodeid, 100, "block");
1847 return;
1848 }
1849 break;
1850 case BlockValidationResult::BLOCK_CACHED_INVALID:
1851 {
1852 // Discourage outbound (but not inbound) peers if on an invalid chain.
1853 // Exempt HB compact block peers. Manual connections are always protected from discouragement.
1854 if (!via_compact_block) {
1855 HandleDoSPunishment(m_connman, nodeid, 100, "block");
1856 return;
1857 }
1858 break;
1859 }
1860 case BlockValidationResult::BLOCK_INVALID_HEADER:
1861 case BlockValidationResult::BLOCK_CHECKPOINT:
1862 case BlockValidationResult::BLOCK_INVALID_PREV:
1863 HandleDoSPunishment(m_connman, nodeid, 100, "block header");
1864 return;
1865 // Conflicting (but not necessarily invalid) data or different policy:
1866 case BlockValidationResult::BLOCK_MISSING_PREV:
1867 HandleDoSPunishment(m_connman, nodeid, 100, "block header");
1868 return;
1869 case BlockValidationResult::BLOCK_TIME_FUTURE:
1870 break;
1871 }
1872 if (message != "") {
1873 LogDebug(BCLog::NET, "peer=%d: %s\n", nodeid, message);
1874 }
1875 }
1876 1877 bool PeerManagerImpl::BlockRequestAllowed(const CBlockIndex* pindex)
1878 {
1879 AssertLockHeld(cs_main);
1880 if (m_chainman.ActiveChain().Contains(pindex)) return true;
1881 return pindex->IsValid(BLOCK_VALID_SCRIPTS) && (m_chainman.m_best_header != nullptr) &&
1882 (m_chainman.m_best_header->GetBlockTime() - pindex->GetBlockTime() < STALE_RELAY_AGE_LIMIT) &&
1883 (GetBlockProofEquivalentTime(*m_chainman.m_best_header, *pindex, *m_chainman.m_best_header, m_chainparams.GetConsensus()) < STALE_RELAY_AGE_LIMIT);
1884 }
1885 1886 std::optional<std::string> PeerManagerImpl::FetchBlock(NodeId peer_id, const uint256& hash, const CBlockIndex* block_index)
1887 {
1888 if (m_chainman.m_blockman.LoadingBlocks()) return "Loading blocks ...";
1889 1890 // Ensure this peer exists and hasn't been disconnected
1891 PeerRef peer = GetPeerRef(peer_id);
1892 if (peer == nullptr) return "Peer does not exist";
1893 1894 // Ignore pre-segwit peers
1895 if (!CanServeWitnesses(*peer)) return "Pre-SegWit peer";
1896 1897 LOCK(cs_main);
1898 1899 if (IsBlockRequestedFromPeer(hash, peer_id)) return "Already requested from this peer";
1900 1901 // Mark block as in-flight unless we don't have the header.
1902 if (block_index != nullptr) {
1903 // Forget about all prior requests
1904 RemoveBlockRequest(hash, std::nullopt);
1905 1906 // Mark block as in-flight
1907 Assume(BlockRequested(peer_id, *block_index));
1908 }
1909 1910 // Construct message to request the block
1911 std::vector<CInv> invs{CInv(MSG_BLOCK | MSG_WITNESS_FLAG, hash)};
1912 1913 // Send block request message to the peer
1914 bool success = m_connman.ForNode(peer_id, [this, &invs](CNode* node) {
1915 this->MakeAndPushMessage(*node, NetMsgType::GETDATA, invs);
1916 return true;
1917 });
1918 1919 if (!success) return "Peer not fully connected";
1920 1921 LogDebug(BCLog::NET, "Requesting block %s from peer=%d\n",
1922 hash.ToString(), peer_id);
1923 return std::nullopt;
1924 }
1925 1926 std::optional<std::string> PeerManager::FetchBlock(NodeId peer_id, const CBlockIndex& block_index)
1927 {
1928 const uint256& hash{block_index.GetBlockHash()};
1929 return FetchBlock(peer_id, hash, &block_index);
1930 }
1931 1932 std::unique_ptr<PeerManager> PeerManager::make(CConnman& connman, AddrMan& addrman,
1933 BanMan* banman, ChainstateManager& chainman,
1934 CTxMemPool& pool, node::Warnings& warnings, Options opts)
1935 {
1936 return std::make_unique<PeerManagerImpl>(connman, addrman, banman, chainman, pool, warnings, opts);
1937 }
1938 1939 static_assert(CORE_INCREMENTAL_RELAY_FEE < DEFAULT_INCREMENTAL_RELAY_FEE, "Trinary logic for m_fee_filter_rounder is based on assumption that CORE_INCREMENTAL_RELAY_FEE is less than DEFAULT_INCREMENTAL_RELAY_FEE");
1940 PeerManagerImpl::PeerManagerImpl(CConnman& connman, AddrMan& addrman,
1941 BanMan* banman, ChainstateManager& chainman,
1942 CTxMemPool& pool, node::Warnings& warnings, Options opts)
1943 : m_rng{opts.deterministic_rng},
1944 m_fee_filter_rounder{CFeeRate{pool.m_opts.incremental_relay_feerate.GetFeePerK() < DEFAULT_INCREMENTAL_RELAY_FEE ? CORE_INCREMENTAL_RELAY_FEE : DEFAULT_INCREMENTAL_RELAY_FEE}, m_rng},
1945 m_chainparams(chainman.GetParams()),
1946 m_connman(connman),
1947 m_addrman(addrman),
1948 m_banman(banman),
1949 m_chainman(chainman),
1950 m_mempool(pool),
1951 m_txdownloadman(node::TxDownloadOptions{pool, m_rng, opts.max_orphan_txs, opts.deterministic_rng}),
1952 m_warnings{warnings},
1953 m_opts{opts}
1954 {
1955 // While Erlay support is incomplete, it must be enabled explicitly via -txreconciliation.
1956 // This argument can go away after Erlay support is complete.
1957 if (opts.reconcile_txs) {
1958 m_txreconciliation = std::make_unique<TxReconciliationTracker>(TXRECONCILIATION_VERSION);
1959 }
1960 }
1961 1962 void PeerManagerImpl::StartScheduledTasks(CScheduler& scheduler)
1963 {
1964 // Stale tip checking and peer eviction are on two different timers, but we
1965 // don't want them to get out of sync due to drift in the scheduler, so we
1966 // combine them in one function and schedule at the quicker (peer-eviction)
1967 // timer.
1968 static_assert(EXTRA_PEER_CHECK_INTERVAL < STALE_CHECK_INTERVAL, "peer eviction timer should be less than stale tip check timer");
1969 scheduler.scheduleEvery([this] { this->CheckForStaleTipAndEvictPeers(); }, std::chrono::seconds{EXTRA_PEER_CHECK_INTERVAL});
1970 1971 // schedule next run for 10-15 minutes in the future
1972 const auto delta = 10min + FastRandomContext().randrange<std::chrono::milliseconds>(5min);
1973 scheduler.scheduleFromNow([&] { ReattemptInitialBroadcast(scheduler); }, delta);
1974 }
1975 1976 void PeerManagerImpl::ActiveTipChange(const CBlockIndex& new_tip, bool is_ibd)
1977 {
1978 // Ensure mempool mutex was released, otherwise deadlock may occur if another thread holding
1979 // m_tx_download_mutex waits on the mempool mutex.
1980 AssertLockNotHeld(m_mempool.cs);
1981 AssertLockNotHeld(m_tx_download_mutex);
1982 1983 if (!is_ibd) {
1984 LOCK(m_tx_download_mutex);
1985 // If the chain tip has changed, previously rejected transactions might now be valid, e.g. due
1986 // to a timelock. Reset the rejection filters to give those transactions another chance if we
1987 // see them again.
1988 m_txdownloadman.ActiveTipChange();
1989 }
1990 }
1991 1992 /**
1993 * Evict orphan txn pool entries based on a newly connected
1994 * block, remember the recently confirmed transactions, and delete tracked
1995 * announcements for them. Also save the time of the last tip update and
1996 * possibly reduce dynamic block stalling timeout.
1997 */
1998 void PeerManagerImpl::BlockConnected(
1999 ChainstateRole role,
2000 const std::shared_ptr<const CBlock>& pblock,
2001 const CBlockIndex* pindex)
2002 {
2003 // Update this for all chainstate roles so that we don't mistakenly see peers
2004 // helping us do background IBD as having a stale tip.
2005 m_last_tip_update = GetTime<std::chrono::seconds>();
2006 2007 // In case the dynamic timeout was doubled once or more, reduce it slowly back to its default value
2008 auto stalling_timeout = m_block_stalling_timeout.load();
2009 Assume(stalling_timeout >= BLOCK_STALLING_TIMEOUT_DEFAULT);
2010 if (stalling_timeout != BLOCK_STALLING_TIMEOUT_DEFAULT) {
2011 const auto new_timeout = std::max(std::chrono::duration_cast<std::chrono::seconds>(stalling_timeout * 0.85), BLOCK_STALLING_TIMEOUT_DEFAULT);
2012 if (m_block_stalling_timeout.compare_exchange_strong(stalling_timeout, new_timeout)) {
2013 LogDebug(BCLog::NET, "Decreased stalling timeout to %d seconds\n", count_seconds(new_timeout));
2014 }
2015 }
2016 2017 // The following task can be skipped since we don't maintain a mempool for
2018 // the ibd/background chainstate.
2019 if (role == ChainstateRole::BACKGROUND) {
2020 return;
2021 }
2022 LOCK(m_tx_download_mutex);
2023 m_txdownloadman.BlockConnected(pblock);
2024 }
2025 2026 void PeerManagerImpl::BlockDisconnected(const std::shared_ptr<const CBlock> &block, const CBlockIndex* pindex)
2027 {
2028 LOCK(m_tx_download_mutex);
2029 m_txdownloadman.BlockDisconnected();
2030 }
2031 2032 /**
2033 * Maintain state about the best-seen block and fast-announce a compact block
2034 * to compatible peers.
2035 */
2036 void PeerManagerImpl::NewPoWValidBlock(const CBlockIndex *pindex, const std::shared_ptr<const CBlock>& pblock)
2037 {
2038 auto pcmpctblock = std::make_shared<const CBlockHeaderAndShortTxIDs>(*pblock, FastRandomContext().rand64());
2039 2040 LOCK(cs_main);
2041 2042 if (pindex->nHeight <= m_highest_fast_announce)
2043 return;
2044 m_highest_fast_announce = pindex->nHeight;
2045 2046 if (!DeploymentActiveAt(*pindex, m_chainman, Consensus::DEPLOYMENT_SEGWIT)) return;
2047 2048 uint256 hashBlock(pblock->GetHash());
2049 const std::shared_future<CSerializedNetMsg> lazy_ser{
2050 std::async(std::launch::deferred, [&] { return NetMsg::Make(NetMsgType::CMPCTBLOCK, *pcmpctblock); })};
2051 2052 {
2053 auto most_recent_block_txs = std::make_unique<std::map<uint256, CTransactionRef>>();
2054 for (const auto& tx : pblock->vtx) {
2055 most_recent_block_txs->emplace(tx->GetHash(), tx);
2056 most_recent_block_txs->emplace(tx->GetWitnessHash(), tx);
2057 }
2058 2059 LOCK(m_most_recent_block_mutex);
2060 m_most_recent_block_hash = hashBlock;
2061 m_most_recent_block = pblock;
2062 m_most_recent_compact_block = pcmpctblock;
2063 m_most_recent_block_txs = std::move(most_recent_block_txs);
2064 }
2065 2066 m_connman.ForEachNode([this, pindex, &lazy_ser, &hashBlock](CNode* pnode) EXCLUSIVE_LOCKS_REQUIRED(::cs_main) {
2067 AssertLockHeld(::cs_main);
2068 2069 if (pnode->GetCommonVersion() < INVALID_CB_NO_BAN_VERSION || pnode->fDisconnect)
2070 return;
2071 ProcessBlockAvailability(pnode->GetId());
2072 CNodeState &state = *State(pnode->GetId());
2073 // If the peer has, or we announced to them the previous block already,
2074 // but we don't think they have this one, go ahead and announce it
2075 if (state.m_requested_hb_cmpctblocks && !PeerHasHeader(&state, pindex) && PeerHasHeader(&state, pindex->pprev)) {
2076 2077 LogDebug(BCLog::NET, "%s sending header-and-ids %s to peer=%d\n", "PeerManager::NewPoWValidBlock",
2078 hashBlock.ToString(), pnode->GetId());
2079 2080 const CSerializedNetMsg& ser_cmpctblock{lazy_ser.get()};
2081 PushMessage(*pnode, ser_cmpctblock.Copy());
2082 state.pindexBestHeaderSent = pindex;
2083 }
2084 });
2085 }
2086 2087 /**
2088 * Update our best height and announce any block hashes which weren't previously
2089 * in m_chainman.ActiveChain() to our peers.
2090 */
2091 void PeerManagerImpl::UpdatedBlockTip(const CBlockIndex *pindexNew, const CBlockIndex *pindexFork, bool fInitialDownload)
2092 {
2093 SetBestBlock(pindexNew->nHeight, std::chrono::seconds{pindexNew->GetBlockTime()});
2094 2095 // Don't relay inventory during initial block download.
2096 if (fInitialDownload) return;
2097 2098 // Find the hashes of all blocks that weren't previously in the best chain.
2099 std::vector<uint256> vHashes;
2100 const CBlockIndex *pindexToAnnounce = pindexNew;
2101 while (pindexToAnnounce != pindexFork) {
2102 vHashes.push_back(pindexToAnnounce->GetBlockHash());
2103 pindexToAnnounce = pindexToAnnounce->pprev;
2104 if (vHashes.size() == MAX_BLOCKS_TO_ANNOUNCE) {
2105 // Limit announcements in case of a huge reorganization.
2106 // Rely on the peer's synchronization mechanism in that case.
2107 break;
2108 }
2109 }
2110 2111 {
2112 LOCK(m_peer_mutex);
2113 for (auto& it : m_peer_map) {
2114 Peer& peer = *it.second;
2115 LOCK(peer.m_block_inv_mutex);
2116 for (const uint256& hash : vHashes | std::views::reverse) {
2117 peer.m_blocks_for_headers_relay.push_back(hash);
2118 }
2119 }
2120 }
2121 2122 m_connman.WakeMessageHandler();
2123 }
2124 2125 /**
2126 * Handle invalid block rejection and consequent peer discouragement, maintain which
2127 * peers announce compact blocks.
2128 */
2129 void PeerManagerImpl::BlockChecked(const CBlock& block, const BlockValidationState& state)
2130 {
2131 LOCK(cs_main);
2132 2133 const uint256 hash(block.GetHash());
2134 std::map<uint256, std::pair<NodeId, bool>>::iterator it = mapBlockSource.find(hash);
2135 2136 // If the block failed validation, we know where it came from and we're still connected
2137 // to that peer, maybe punish.
2138 if (state.IsInvalid() &&
2139 it != mapBlockSource.end() &&
2140 State(it->second.first)) {
2141 MaybePunishNodeForBlock(/*nodeid=*/ it->second.first, state, /*via_compact_block=*/ !it->second.second);
2142 }
2143 // Check that:
2144 // 1. The block is valid
2145 // 2. We're not in initial block download
2146 // 3. This is currently the best block we're aware of. We haven't updated
2147 // the tip yet so we have no way to check this directly here. Instead we
2148 // just check that there are currently no other blocks in flight.
2149 else if (state.IsValid() &&
2150 !m_chainman.IsInitialBlockDownload() &&
2151 mapBlocksInFlight.count(hash) == mapBlocksInFlight.size()) {
2152 if (it != mapBlockSource.end()) {
2153 MaybeSetPeerAsAnnouncingHeaderAndIDs(it->second.first);
2154 }
2155 }
2156 if (it != mapBlockSource.end())
2157 mapBlockSource.erase(it);
2158 }
2159 2160 //////////////////////////////////////////////////////////////////////////////
2161 //
2162 // Messages
2163 //
2164 2165 bool PeerManagerImpl::AlreadyHaveBlock(const uint256& block_hash)
2166 {
2167 return m_chainman.m_blockman.LookupBlockIndex(block_hash) != nullptr;
2168 }
2169 2170 void PeerManagerImpl::SendPings()
2171 {
2172 LOCK(m_peer_mutex);
2173 for(auto& it : m_peer_map) it.second->m_ping_queued = true;
2174 }
2175 2176 void PeerManagerImpl::RelayTransaction(const uint256& txid, const uint256& wtxid)
2177 {
2178 LOCK(m_peer_mutex);
2179 for(auto& it : m_peer_map) {
2180 Peer& peer = *it.second;
2181 auto tx_relay = peer.GetTxRelay();
2182 if (!tx_relay) continue;
2183 2184 LOCK(tx_relay->m_tx_inventory_mutex);
2185 // Only queue transactions for announcement once the version handshake
2186 // is completed. The time of arrival for these transactions is
2187 // otherwise at risk of leaking to a spy, if the spy is able to
2188 // distinguish transactions received during the handshake from the rest
2189 // in the announcement.
2190 if (tx_relay->m_next_inv_send_time == 0s) continue;
2191 2192 const uint256& hash{peer.m_wtxid_relay ? wtxid : txid};
2193 if (!tx_relay->m_tx_inventory_known_filter.contains(hash)) {
2194 tx_relay->m_tx_inventory_to_send.insert(hash);
2195 }
2196 };
2197 }
2198 2199 void PeerManagerImpl::RelayAddress(NodeId originator,
2200 const CAddress& addr,
2201 bool fReachable)
2202 {
2203 // We choose the same nodes within a given 24h window (if the list of connected
2204 // nodes does not change) and we don't relay to nodes that already know an
2205 // address. So within 24h we will likely relay a given address once. This is to
2206 // prevent a peer from unjustly giving their address better propagation by sending
2207 // it to us repeatedly.
2208 2209 if (!fReachable && !addr.IsRelayable()) return;
2210 2211 // Relay to a limited number of other nodes
2212 // Use deterministic randomness to send to the same nodes for 24 hours
2213 // at a time so the m_addr_knowns of the chosen nodes prevent repeats
2214 const uint64_t hash_addr{CServiceHash(0, 0)(addr)};
2215 const auto current_time{GetTime<std::chrono::seconds>()};
2216 // Adding address hash makes exact rotation time different per address, while preserving periodicity.
2217 const uint64_t time_addr{(static_cast<uint64_t>(count_seconds(current_time)) + hash_addr) / count_seconds(ROTATE_ADDR_RELAY_DEST_INTERVAL)};
2218 const CSipHasher hasher{m_connman.GetDeterministicRandomizer(RANDOMIZER_ID_ADDRESS_RELAY)
2219 .Write(hash_addr)
2220 .Write(time_addr)};
2221 2222 // Relay reachable addresses to 2 peers. Unreachable addresses are relayed randomly to 1 or 2 peers.
2223 unsigned int nRelayNodes = (fReachable || (hasher.Finalize() & 1)) ? 2 : 1;
2224 2225 std::array<std::pair<uint64_t, Peer*>, 2> best{{{0, nullptr}, {0, nullptr}}};
2226 assert(nRelayNodes <= best.size());
2227 2228 LOCK(m_peer_mutex);
2229 2230 for (auto& [id, peer] : m_peer_map) {
2231 if (peer->m_addr_relay_enabled && id != originator && IsAddrCompatible(*peer, addr)) {
2232 uint64_t hashKey = CSipHasher(hasher).Write(id).Finalize();
2233 for (unsigned int i = 0; i < nRelayNodes; i++) {
2234 if (hashKey > best[i].first) {
2235 std::copy(best.begin() + i, best.begin() + nRelayNodes - 1, best.begin() + i + 1);
2236 best[i] = std::make_pair(hashKey, peer.get());
2237 break;
2238 }
2239 }
2240 }
2241 };
2242 2243 for (unsigned int i = 0; i < nRelayNodes && best[i].first != 0; i++) {
2244 PushAddress(*best[i].second, addr);
2245 }
2246 }
2247 2248 void PeerManagerImpl::ProcessGetBlockData(CNode& pfrom, Peer& peer, const CInv& inv)
2249 {
2250 std::shared_ptr<const CBlock> a_recent_block;
2251 std::shared_ptr<const CBlockHeaderAndShortTxIDs> a_recent_compact_block;
2252 {
2253 LOCK(m_most_recent_block_mutex);
2254 a_recent_block = m_most_recent_block;
2255 a_recent_compact_block = m_most_recent_compact_block;
2256 }
2257 2258 bool need_activate_chain = false;
2259 {
2260 LOCK(cs_main);
2261 const CBlockIndex* pindex = m_chainman.m_blockman.LookupBlockIndex(inv.hash);
2262 if (pindex) {
2263 if (pindex->HaveNumChainTxs() && !pindex->IsValid(BLOCK_VALID_SCRIPTS) &&
2264 pindex->IsValid(BLOCK_VALID_TREE)) {
2265 // If we have the block and all of its parents, but have not yet validated it,
2266 // we might be in the middle of connecting it (ie in the unlock of cs_main
2267 // before ActivateBestChain but after AcceptBlock).
2268 // In this case, we need to run ActivateBestChain prior to checking the relay
2269 // conditions below.
2270 need_activate_chain = true;
2271 }
2272 }
2273 } // release cs_main before calling ActivateBestChain
2274 if (need_activate_chain) {
2275 BlockValidationState state;
2276 if (!m_chainman.ActiveChainstate().ActivateBestChain(state, a_recent_block)) {
2277 LogDebug(BCLog::NET, "failed to activate chain (%s)\n", state.ToString());
2278 }
2279 }
2280 2281 const CBlockIndex* pindex{nullptr};
2282 const CBlockIndex* tip{nullptr};
2283 bool can_direct_fetch{false};
2284 FlatFilePos block_pos{};
2285 {
2286 LOCK(cs_main);
2287 pindex = m_chainman.m_blockman.LookupBlockIndex(inv.hash);
2288 if (!pindex) {
2289 return;
2290 }
2291 if (!BlockRequestAllowed(pindex)) {
2292 LogDebug(BCLog::NET, "%s: ignoring request from peer=%i for old block that isn't in the main chain\n", __func__, pfrom.GetId());
2293 return;
2294 }
2295 // disconnect node in case we have reached the outbound limit for serving historical blocks
2296 if (m_connman.OutboundTargetReached(true) &&
2297 (((m_chainman.m_best_header != nullptr) && (m_chainman.m_best_header->GetBlockTime() - pindex->GetBlockTime() > HISTORICAL_BLOCK_AGE)) || inv.IsMsgFilteredBlk() || inv.IsMsgFilteredWitnessBlk()) &&
2298 !pfrom.HasPermission(NetPermissionFlags::Download) // nodes with the download permission may exceed target
2299 ) {
2300 LogDebug(BCLog::NET, "historical block serving limit reached, %s\n", pfrom.DisconnectMsg(fLogIPs));
2301 pfrom.fDisconnect = true;
2302 return;
2303 }
2304 tip = m_chainman.ActiveChain().Tip();
2305 // Avoid leaking prune-height by never sending blocks below the NODE_NETWORK_LIMITED threshold
2306 if (!pfrom.HasPermission(NetPermissionFlags::NoBan) && (
2307 (((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 */) )
2308 )) {
2309 LogDebug(BCLog::NET, "Ignore block request below NODE_NETWORK_LIMITED threshold, %s\n", pfrom.DisconnectMsg(fLogIPs));
2310 //disconnect node and prevent it from stalling (would otherwise wait for the missing block)
2311 pfrom.fDisconnect = true;
2312 return;
2313 }
2314 // Pruned nodes may have deleted the block, so check whether
2315 // it's available before trying to send.
2316 if (!(pindex->nStatus & BLOCK_HAVE_DATA)) {
2317 return;
2318 }
2319 can_direct_fetch = CanDirectFetch();
2320 block_pos = pindex->GetBlockPos();
2321 }
2322 2323 std::shared_ptr<const CBlock> pblock;
2324 if (a_recent_block && a_recent_block->GetHash() == pindex->GetBlockHash()) {
2325 pblock = a_recent_block;
2326 } else if (inv.IsMsgWitnessBlk()) {
2327 // Fast-path: in this case it is possible to serve the block directly from disk,
2328 // as the network format matches the format on disk
2329 std::vector<uint8_t> block_data;
2330 if (!m_chainman.m_blockman.ReadRawBlock(block_data, block_pos, /*lowprio=*/true)) {
2331 if (WITH_LOCK(m_chainman.GetMutex(), return m_chainman.m_blockman.IsBlockPruned(*pindex))) {
2332 LogDebug(BCLog::NET, "Block was pruned before it could be read, %s\n", pfrom.DisconnectMsg(fLogIPs));
2333 } else {
2334 LogError("Cannot load block from disk, %s\n", pfrom.DisconnectMsg(fLogIPs));
2335 }
2336 pfrom.fDisconnect = true;
2337 return;
2338 }
2339 MakeAndPushMessage(pfrom, NetMsgType::BLOCK, Span{block_data});
2340 // Don't set pblock as we've sent the block
2341 } else {
2342 // Send block from disk
2343 std::shared_ptr<CBlock> pblockRead = std::make_shared<CBlock>();
2344 if (!m_chainman.m_blockman.ReadBlock(*pblockRead, block_pos, /*expected_hash=*/ inv.hash, /*lowprio=*/true)) {
2345 if (WITH_LOCK(m_chainman.GetMutex(), return m_chainman.m_blockman.IsBlockPruned(*pindex))) {
2346 LogDebug(BCLog::NET, "Block was pruned before it could be read, %s\n", pfrom.DisconnectMsg(fLogIPs));
2347 } else {
2348 LogError("Cannot load block from disk, %s\n", pfrom.DisconnectMsg(fLogIPs));
2349 }
2350 pfrom.fDisconnect = true;
2351 return;
2352 }
2353 pblock = pblockRead;
2354 }
2355 if (pblock) {
2356 if (inv.IsMsgBlk()) {
2357 MakeAndPushMessage(pfrom, NetMsgType::BLOCK, TX_NO_WITNESS(*pblock));
2358 } else if (inv.IsMsgWitnessBlk()) {
2359 MakeAndPushMessage(pfrom, NetMsgType::BLOCK, TX_WITH_WITNESS(*pblock));
2360 } else if (inv.IsMsgFilteredBlk() || inv.IsMsgFilteredWitnessBlk()) {
2361 bool sendMerkleBlock = false;
2362 CMerkleBlock merkleBlock;
2363 if (auto tx_relay = peer.GetTxRelay(); tx_relay != nullptr) {
2364 LOCK(tx_relay->m_bloom_filter_mutex);
2365 if (tx_relay->m_bloom_filter) {
2366 sendMerkleBlock = true;
2367 merkleBlock = CMerkleBlock(*pblock, *tx_relay->m_bloom_filter);
2368 }
2369 }
2370 if (sendMerkleBlock) {
2371 MakeAndPushMessage(pfrom, NetMsgType::MERKLEBLOCK, merkleBlock);
2372 // CMerkleBlock just contains hashes, so also push any transactions in the block the client did not see
2373 // This avoids hurting performance by pointlessly requiring a round-trip
2374 // Note that there is currently no way for a node to request any single transactions we didn't send here -
2375 // they must either disconnect and retry or request the full block.
2376 // Thus, the protocol spec specified allows for us to provide duplicate txn here,
2377 // however we MUST always provide at least what the remote peer needs
2378 const auto maybe_with_witness = (inv.IsMsgFilteredWitnessBlk() ? TX_WITH_WITNESS : TX_NO_WITNESS);
2379 typedef std::pair<unsigned int, uint256> PairType;
2380 for (PairType& pair : merkleBlock.vMatchedTxn)
2381 MakeAndPushMessage(pfrom, NetMsgType::TX, maybe_with_witness(*pblock->vtx[pair.first]));
2382 }
2383 // else
2384 // no response
2385 } else if (inv.IsMsgCmpctBlk()) {
2386 // If a peer is asking for old blocks, we're almost guaranteed
2387 // they won't have a useful mempool to match against a compact block,
2388 // and we don't feel like constructing the object for them, so
2389 // instead we respond with the full, non-compact block.
2390 if (can_direct_fetch && pindex->nHeight >= tip->nHeight - MAX_CMPCTBLOCK_DEPTH) {
2391 if (a_recent_compact_block && a_recent_compact_block->header.GetHash() == pindex->GetBlockHash()) {
2392 MakeAndPushMessage(pfrom, NetMsgType::CMPCTBLOCK, *a_recent_compact_block);
2393 } else {
2394 CBlockHeaderAndShortTxIDs cmpctblock{*pblock, m_rng.rand64()};
2395 MakeAndPushMessage(pfrom, NetMsgType::CMPCTBLOCK, cmpctblock);
2396 }
2397 } else {
2398 MakeAndPushMessage(pfrom, NetMsgType::BLOCK, TX_WITH_WITNESS(*pblock));
2399 }
2400 }
2401 }
2402 2403 {
2404 LOCK(peer.m_block_inv_mutex);
2405 // Trigger the peer node to send a getblocks request for the next batch of inventory
2406 if (inv.hash == peer.m_continuation_block) {
2407 // Send immediately. This must send even if redundant,
2408 // and we want it right after the last block so they don't
2409 // wait for other stuff first.
2410 std::vector<CInv> vInv;
2411 vInv.emplace_back(MSG_BLOCK, tip->GetBlockHash());
2412 MakeAndPushMessage(pfrom, NetMsgType::INV, vInv);
2413 peer.m_continuation_block.SetNull();
2414 }
2415 }
2416 }
2417 2418 CTransactionRef PeerManagerImpl::FindTxForGetData(const Peer::TxRelay& tx_relay, const GenTxid& gtxid)
2419 {
2420 // If a tx was in the mempool prior to the last INV for this peer, permit the request.
2421 auto txinfo = m_mempool.info_for_relay(gtxid, tx_relay.m_last_inv_sequence);
2422 if (txinfo.tx) {
2423 return std::move(txinfo.tx);
2424 }
2425 2426 // Or it might be from the most recent block
2427 {
2428 LOCK(m_most_recent_block_mutex);
2429 if (m_most_recent_block_txs != nullptr) {
2430 auto it = m_most_recent_block_txs->find(gtxid.GetHash());
2431 if (it != m_most_recent_block_txs->end()) return it->second;
2432 }
2433 }
2434 2435 return {};
2436 }
2437 2438 void PeerManagerImpl::ProcessGetData(CNode& pfrom, Peer& peer, const std::atomic<bool>& interruptMsgProc)
2439 {
2440 AssertLockNotHeld(cs_main);
2441 2442 auto tx_relay = peer.GetTxRelay();
2443 2444 std::deque<CInv>::iterator it = peer.m_getdata_requests.begin();
2445 std::vector<CInv> vNotFound;
2446 2447 // Process as many TX items from the front of the getdata queue as
2448 // possible, since they're common and it's efficient to batch process
2449 // them.
2450 while (it != peer.m_getdata_requests.end() && it->IsGenTxMsg()) {
2451 if (interruptMsgProc) return;
2452 // The send buffer provides backpressure. If there's no space in
2453 // the buffer, pause processing until the next call.
2454 if (pfrom.fPauseSend) break;
2455 2456 const CInv &inv = *it++;
2457 2458 if (tx_relay == nullptr) {
2459 // Ignore GETDATA requests for transactions from block-relay-only
2460 // peers and peers that asked us not to announce transactions.
2461 continue;
2462 }
2463 2464 CTransactionRef tx = FindTxForGetData(*tx_relay, ToGenTxid(inv));
2465 if (tx) {
2466 // WTX and WITNESS_TX imply we serialize with witness
2467 const auto maybe_with_witness = (inv.IsMsgTx() ? TX_NO_WITNESS : TX_WITH_WITNESS);
2468 MakeAndPushMessage(pfrom, NetMsgType::TX, maybe_with_witness(*tx));
2469 m_mempool.RemoveUnbroadcastTx(tx->GetHash());
2470 } else {
2471 vNotFound.push_back(inv);
2472 }
2473 }
2474 2475 // Only process one BLOCK item per call, since they're uncommon and can be
2476 // expensive to process.
2477 if (it != peer.m_getdata_requests.end() && !pfrom.fPauseSend) {
2478 const CInv &inv = *it++;
2479 if (inv.IsGenBlkMsg()) {
2480 ProcessGetBlockData(pfrom, peer, inv);
2481 }
2482 // else: If the first item on the queue is an unknown type, we erase it
2483 // and continue processing the queue on the next call.
2484 }
2485 2486 peer.m_getdata_requests.erase(peer.m_getdata_requests.begin(), it);
2487 2488 if (!vNotFound.empty()) {
2489 // Let the peer know that we didn't find what it asked for, so it doesn't
2490 // have to wait around forever.
2491 // SPV clients care about this message: it's needed when they are
2492 // recursively walking the dependencies of relevant unconfirmed
2493 // transactions. SPV clients want to do that because they want to know
2494 // about (and store and rebroadcast and risk analyze) the dependencies
2495 // of transactions relevant to them, without having to download the
2496 // entire memory pool.
2497 // Also, other nodes can use these messages to automatically request a
2498 // transaction from some other peer that announced it, and stop
2499 // waiting for us to respond.
2500 // In normal operation, we often send NOTFOUND messages for parents of
2501 // transactions that we relay; if a peer is missing a parent, they may
2502 // assume we have them and request the parents from us.
2503 MakeAndPushMessage(pfrom, NetMsgType::NOTFOUND, vNotFound);
2504 }
2505 }
2506 2507 uint32_t PeerManagerImpl::GetFetchFlags(const Peer& peer) const
2508 {
2509 uint32_t nFetchFlags = 0;
2510 if (CanServeWitnesses(peer)) {
2511 nFetchFlags |= MSG_WITNESS_FLAG;
2512 }
2513 return nFetchFlags;
2514 }
2515 2516 void PeerManagerImpl::SendBlockTransactions(CNode& pfrom, Peer& peer, const CBlock& block, const BlockTransactionsRequest& req)
2517 {
2518 BlockTransactions resp(req);
2519 for (size_t i = 0; i < req.indexes.size(); i++) {
2520 if (req.indexes[i] >= block.vtx.size()) {
2521 Misbehaving(peer, "getblocktxn with out-of-bounds tx indices");
2522 return;
2523 }
2524 resp.txn[i] = block.vtx[req.indexes[i]];
2525 }
2526 2527 MakeAndPushMessage(pfrom, NetMsgType::BLOCKTXN, resp);
2528 }
2529 2530 bool PeerManagerImpl::CheckHeadersPoW(const std::vector<CBlockHeader>& headers, const Consensus::Params& consensusParams, Peer& peer)
2531 {
2532 // Do these headers have proof-of-work matching what's claimed?
2533 if (!HasValidProofOfWork(headers, consensusParams)) {
2534 Misbehaving(peer, "header with invalid proof of work");
2535 return false;
2536 }
2537 2538 // Are these headers connected to each other?
2539 if (!CheckHeadersAreContinuous(headers)) {
2540 Misbehaving(peer, "non-continuous headers sequence");
2541 return false;
2542 }
2543 return true;
2544 }
2545 2546 arith_uint256 PeerManagerImpl::GetAntiDoSWorkThreshold()
2547 {
2548 arith_uint256 near_chaintip_work = 0;
2549 LOCK(cs_main);
2550 if (m_chainman.ActiveChain().Tip() != nullptr) {
2551 const CBlockIndex *tip = m_chainman.ActiveChain().Tip();
2552 // Use a 144 block buffer, so that we'll accept headers that fork from
2553 // near our tip.
2554 near_chaintip_work = tip->nChainWork - std::min<arith_uint256>(144*GetBlockProof(*tip), tip->nChainWork);
2555 }
2556 return std::max(near_chaintip_work, m_chainman.MinimumChainWork());
2557 }
2558 2559 /**
2560 * Special handling for unconnecting headers that might be part of a block
2561 * announcement.
2562 *
2563 * We'll send a getheaders message in response to try to connect the chain.
2564 */
2565 void PeerManagerImpl::HandleUnconnectingHeaders(CNode& pfrom, Peer& peer,
2566 const std::vector<CBlockHeader>& headers)
2567 {
2568 // Try to fill in the missing headers.
2569 const CBlockIndex* best_header{WITH_LOCK(cs_main, return m_chainman.m_best_header)};
2570 if (MaybeSendGetHeaders(pfrom, GetLocator(best_header), peer)) {
2571 LogDebug(BCLog::NET, "received header %s: missing prev block %s, sending getheaders (%d) to end (peer=%d)\n",
2572 headers[0].GetHash().ToString(),
2573 headers[0].hashPrevBlock.ToString(),
2574 best_header->nHeight,
2575 pfrom.GetId());
2576 }
2577 2578 // Set hashLastUnknownBlock for this peer, so that if we
2579 // eventually get the headers - even from a different peer -
2580 // we can use this peer to download.
2581 WITH_LOCK(cs_main, UpdateBlockAvailability(pfrom.GetId(), headers.back().GetHash()));
2582 2583 if (pfrom.PunishInvalidBlocks()) {
2584 pfrom.fDisconnect = true;
2585 }
2586 }
2587 2588 bool PeerManagerImpl::CheckHeadersAreContinuous(const std::vector<CBlockHeader>& headers) const
2589 {
2590 uint256 hashLastBlock;
2591 for (const CBlockHeader& header : headers) {
2592 if (!hashLastBlock.IsNull() && header.hashPrevBlock != hashLastBlock) {
2593 return false;
2594 }
2595 hashLastBlock = header.GetHash();
2596 }
2597 return true;
2598 }
2599 2600 bool PeerManagerImpl::IsContinuationOfLowWorkHeadersSync(Peer& peer, CNode& pfrom, std::vector<CBlockHeader>& headers)
2601 {
2602 if (peer.m_headers_sync) {
2603 auto result = peer.m_headers_sync->ProcessNextHeaders(headers, headers.size() == m_opts.max_headers_result);
2604 // If it is a valid continuation, we should treat the existing getheaders request as responded to.
2605 if (result.success) peer.m_last_getheaders_timestamp = {};
2606 if (result.request_more) {
2607 auto locator = peer.m_headers_sync->NextHeadersRequestLocator();
2608 // If we were instructed to ask for a locator, it should not be empty.
2609 Assume(!locator.vHave.empty());
2610 // We can only be instructed to request more if processing was successful.
2611 Assume(result.success);
2612 if (!locator.vHave.empty()) {
2613 // It should be impossible for the getheaders request to fail,
2614 // because we just cleared the last getheaders timestamp.
2615 bool sent_getheaders = MaybeSendGetHeaders(pfrom, locator, peer);
2616 Assume(sent_getheaders);
2617 LogDebug(BCLog::NET, "more getheaders (from %s) to peer=%d\n",
2618 locator.vHave.front().ToString(), pfrom.GetId());
2619 }
2620 }
2621 2622 if (peer.m_headers_sync->GetState() == HeadersSyncState::State::FINAL) {
2623 peer.m_headers_sync.reset(nullptr);
2624 2625 // Delete this peer's entry in m_headers_presync_stats.
2626 // If this is m_headers_presync_bestpeer, it will be replaced later
2627 // by the next peer that triggers the else{} branch below.
2628 LOCK(m_headers_presync_mutex);
2629 m_headers_presync_stats.erase(pfrom.GetId());
2630 } else {
2631 // Build statistics for this peer's sync.
2632 HeadersPresyncStats stats;
2633 stats.first = peer.m_headers_sync->GetPresyncWork();
2634 if (peer.m_headers_sync->GetState() == HeadersSyncState::State::PRESYNC) {
2635 stats.second = {peer.m_headers_sync->GetPresyncHeight(),
2636 peer.m_headers_sync->GetPresyncTime()};
2637 }
2638 2639 // Update statistics in stats.
2640 LOCK(m_headers_presync_mutex);
2641 m_headers_presync_stats[pfrom.GetId()] = stats;
2642 auto best_it = m_headers_presync_stats.find(m_headers_presync_bestpeer);
2643 bool best_updated = false;
2644 if (best_it == m_headers_presync_stats.end()) {
2645 // If the cached best peer is outdated, iterate over all remaining ones (including
2646 // newly updated one) to find the best one.
2647 NodeId peer_best{-1};
2648 const HeadersPresyncStats* stat_best{nullptr};
2649 for (const auto& [peer, stat] : m_headers_presync_stats) {
2650 if (!stat_best || stat > *stat_best) {
2651 peer_best = peer;
2652 stat_best = &stat;
2653 }
2654 }
2655 m_headers_presync_bestpeer = peer_best;
2656 best_updated = (peer_best == pfrom.GetId());
2657 } else if (best_it->first == pfrom.GetId() || stats > best_it->second) {
2658 // pfrom was and remains the best peer, or pfrom just became best.
2659 m_headers_presync_bestpeer = pfrom.GetId();
2660 best_updated = true;
2661 }
2662 if (best_updated && stats.second.has_value()) {
2663 // If the best peer updated, and it is in its first phase, signal.
2664 m_headers_presync_should_signal = true;
2665 }
2666 }
2667 2668 if (result.success) {
2669 // We only overwrite the headers passed in if processing was
2670 // successful.
2671 headers.swap(result.pow_validated_headers);
2672 }
2673 2674 return result.success;
2675 }
2676 // Either we didn't have a sync in progress, or something went wrong
2677 // processing these headers, or we are returning headers to the caller to
2678 // process.
2679 return false;
2680 }
2681 2682 bool PeerManagerImpl::TryLowWorkHeadersSync(Peer& peer, CNode& pfrom, const CBlockIndex* chain_start_header, std::vector<CBlockHeader>& headers)
2683 {
2684 // Calculate the claimed total work on this chain.
2685 arith_uint256 total_work = chain_start_header->nChainWork + CalculateClaimedHeadersWork(headers);
2686 2687 // Our dynamic anti-DoS threshold (minimum work required on a headers chain
2688 // before we'll store it)
2689 arith_uint256 minimum_chain_work = GetAntiDoSWorkThreshold();
2690 2691 // Avoid DoS via low-difficulty-headers by only processing if the headers
2692 // are part of a chain with sufficient work.
2693 if (total_work < minimum_chain_work) {
2694 // Only try to sync with this peer if their headers message was full;
2695 // otherwise they don't have more headers after this so no point in
2696 // trying to sync their too-little-work chain.
2697 if (headers.size() == m_opts.max_headers_result) {
2698 // Note: we could advance to the last header in this set that is
2699 // known to us, rather than starting at the first header (which we
2700 // may already have); however this is unlikely to matter much since
2701 // ProcessHeadersMessage() already handles the case where all
2702 // headers in a received message are already known and are
2703 // ancestors of m_best_header or chainActive.Tip(), by skipping
2704 // this logic in that case. So even if the first header in this set
2705 // of headers is known, some header in this set must be new, so
2706 // advancing to the first unknown header would be a small effect.
2707 LOCK(peer.m_headers_sync_mutex);
2708 peer.m_headers_sync.reset(new HeadersSyncState(peer.m_id, m_chainparams.GetConsensus(),
2709 chain_start_header, minimum_chain_work));
2710 2711 // Now a HeadersSyncState object for tracking this synchronization
2712 // is created, process the headers using it as normal. Failures are
2713 // handled inside of IsContinuationOfLowWorkHeadersSync.
2714 (void)IsContinuationOfLowWorkHeadersSync(peer, pfrom, headers);
2715 } else {
2716 LogDebug(BCLog::NET, "Ignoring low-work chain (height=%u) from peer=%d\n", chain_start_header->nHeight + headers.size(), pfrom.GetId());
2717 }
2718 2719 // The peer has not yet given us a chain that meets our work threshold,
2720 // so we want to prevent further processing of the headers in any case.
2721 headers = {};
2722 return true;
2723 }
2724 2725 return false;
2726 }
2727 2728 bool PeerManagerImpl::IsAncestorOfBestHeaderOrTip(const CBlockIndex* header)
2729 {
2730 if (header == nullptr) {
2731 return false;
2732 } else if (m_chainman.m_best_header != nullptr && header == m_chainman.m_best_header->GetAncestor(header->nHeight)) {
2733 return true;
2734 } else if (m_chainman.ActiveChain().Contains(header)) {
2735 return true;
2736 }
2737 return false;
2738 }
2739 2740 bool PeerManagerImpl::MaybeSendGetHeaders(CNode& pfrom, const CBlockLocator& locator, Peer& peer)
2741 {
2742 const auto current_time = NodeClock::now();
2743 2744 // Only allow a new getheaders message to go out if we don't have a recent
2745 // one already in-flight
2746 if (current_time - peer.m_last_getheaders_timestamp > HEADERS_RESPONSE_TIME) {
2747 MakeAndPushMessage(pfrom, NetMsgType::GETHEADERS, locator, uint256());
2748 peer.m_last_getheaders_timestamp = current_time;
2749 return true;
2750 }
2751 return false;
2752 }
2753 2754 /*
2755 * Given a new headers tip ending in last_header, potentially request blocks towards that tip.
2756 * We require that the given tip have at least as much work as our tip, and for
2757 * our current tip to be "close to synced" (see CanDirectFetch()).
2758 */
2759 void PeerManagerImpl::HeadersDirectFetchBlocks(CNode& pfrom, const Peer& peer, const CBlockIndex& last_header)
2760 {
2761 LOCK(cs_main);
2762 CNodeState *nodestate = State(pfrom.GetId());
2763 2764 if (CanDirectFetch() && last_header.IsValid(BLOCK_VALID_TREE) && m_chainman.ActiveChain().Tip()->nChainWork <= last_header.nChainWork) {
2765 std::vector<const CBlockIndex*> vToFetch;
2766 const CBlockIndex* pindexWalk{&last_header};
2767 // Calculate all the blocks we'd need to switch to last_header, up to a limit.
2768 while (pindexWalk && !m_chainman.ActiveChain().Contains(pindexWalk) && vToFetch.size() <= MAX_BLOCKS_IN_TRANSIT_PER_PEER) {
2769 if (!(pindexWalk->nStatus & BLOCK_HAVE_DATA) &&
2770 !IsBlockRequested(pindexWalk->GetBlockHash()) &&
2771 (!DeploymentActiveAt(*pindexWalk, m_chainman, Consensus::DEPLOYMENT_SEGWIT) || CanServeWitnesses(peer))) {
2772 // We don't have this block, and it's not yet in flight.
2773 vToFetch.push_back(pindexWalk);
2774 }
2775 pindexWalk = pindexWalk->pprev;
2776 }
2777 // If pindexWalk still isn't on our main chain, we're looking at a
2778 // very large reorg at a time we think we're close to caught up to
2779 // the main chain -- this shouldn't really happen. Bail out on the
2780 // direct fetch and rely on parallel download instead.
2781 if (!m_chainman.ActiveChain().Contains(pindexWalk)) {
2782 LogDebug(BCLog::NET, "Large reorg, won't direct fetch to %s (%d)\n",
2783 last_header.GetBlockHash().ToString(),
2784 last_header.nHeight);
2785 } else {
2786 std::vector<CInv> vGetData;
2787 // Download as much as possible, from earliest to latest.
2788 for (const CBlockIndex* pindex : vToFetch | std::views::reverse) {
2789 if (nodestate->vBlocksInFlight.size() >= MAX_BLOCKS_IN_TRANSIT_PER_PEER) {
2790 // Can't download any more from this peer
2791 break;
2792 }
2793 uint32_t nFetchFlags = GetFetchFlags(peer);
2794 vGetData.emplace_back(MSG_BLOCK | nFetchFlags, pindex->GetBlockHash());
2795 BlockRequested(pfrom.GetId(), *pindex);
2796 LogDebug(BCLog::NET, "Requesting block %s from peer=%d\n",
2797 pindex->GetBlockHash().ToString(), pfrom.GetId());
2798 }
2799 if (vGetData.size() > 1) {
2800 LogDebug(BCLog::NET, "Downloading blocks toward %s (%d) via headers direct fetch\n",
2801 last_header.GetBlockHash().ToString(),
2802 last_header.nHeight);
2803 }
2804 if (vGetData.size() > 0) {
2805 if (!m_opts.ignore_incoming_txs &&
2806 nodestate->m_provides_cmpctblocks &&
2807 vGetData.size() == 1 &&
2808 mapBlocksInFlight.size() == 1 &&
2809 last_header.pprev->IsValid(BLOCK_VALID_CHAIN)) {
2810 // In any case, we want to download using a compact block, not a regular one
2811 vGetData[0] = CInv(MSG_CMPCT_BLOCK, vGetData[0].hash);
2812 }
2813 MakeAndPushMessage(pfrom, NetMsgType::GETDATA, vGetData);
2814 }
2815 }
2816 }
2817 }
2818 2819 /**
2820 * Given receipt of headers from a peer ending in last_header, along with
2821 * whether that header was new and whether the headers message was full,
2822 * update the state we keep for the peer.
2823 */
2824 void PeerManagerImpl::UpdatePeerStateForReceivedHeaders(CNode& pfrom, Peer& peer,
2825 const CBlockIndex& last_header, bool received_new_header, bool may_have_more_headers)
2826 {
2827 LOCK(cs_main);
2828 CNodeState *nodestate = State(pfrom.GetId());
2829 2830 UpdateBlockAvailability(pfrom.GetId(), last_header.GetBlockHash());
2831 2832 // From here, pindexBestKnownBlock should be guaranteed to be non-null,
2833 // because it is set in UpdateBlockAvailability. Some nullptr checks
2834 // are still present, however, as belt-and-suspenders.
2835 2836 if (received_new_header && last_header.nChainWork > m_chainman.ActiveChain().Tip()->nChainWork) {
2837 nodestate->m_last_block_announcement = GetTime();
2838 }
2839 2840 // If we're in IBD, we want outbound peers that will serve us a useful
2841 // chain. Disconnect peers that are on chains with insufficient work.
2842 if (m_chainman.IsInitialBlockDownload() && !may_have_more_headers) {
2843 // If the peer has no more headers to give us, then we know we have
2844 // their tip.
2845 if (nodestate->pindexBestKnownBlock && nodestate->pindexBestKnownBlock->nChainWork < m_chainman.MinimumChainWork()) {
2846 // This peer has too little work on their headers chain to help
2847 // us sync -- disconnect if it is an outbound disconnection
2848 // candidate.
2849 // Note: We compare their tip to the minimum chain work (rather than
2850 // m_chainman.ActiveChain().Tip()) because we won't start block download
2851 // until we have a headers chain that has at least
2852 // the minimum chain work, even if a peer has a chain past our tip,
2853 // as an anti-DoS measure.
2854 if (pfrom.IsOutboundOrBlockRelayConn()) {
2855 LogInfo("outbound peer headers chain has insufficient work, %s\n", pfrom.DisconnectMsg(fLogIPs));
2856 pfrom.fDisconnect = true;
2857 }
2858 }
2859 }
2860 2861 // If this is an outbound full-relay peer, check to see if we should protect
2862 // it from the bad/lagging chain logic.
2863 // Note that outbound block-relay peers are excluded from this protection, and
2864 // thus always subject to eviction under the bad/lagging chain logic.
2865 // See ChainSyncTimeoutState.
2866 if (!pfrom.fDisconnect && pfrom.IsFullOutboundConn() && nodestate->pindexBestKnownBlock != nullptr) {
2867 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) {
2868 LogDebug(BCLog::NET, "Protecting outbound peer=%d from eviction\n", pfrom.GetId());
2869 nodestate->m_chain_sync.m_protect = true;
2870 ++m_outbound_peers_with_protect_from_disconnect;
2871 }
2872 }
2873 }
2874 2875 void PeerManagerImpl::ProcessHeadersMessage(CNode& pfrom, Peer& peer,
2876 std::vector<CBlockHeader>&& headers,
2877 bool via_compact_block)
2878 {
2879 size_t nCount = headers.size();
2880 2881 if (nCount == 0) {
2882 // Nothing interesting. Stop asking this peers for more headers.
2883 // If we were in the middle of headers sync, receiving an empty headers
2884 // message suggests that the peer suddenly has nothing to give us
2885 // (perhaps it reorged to our chain). Clear download state for this peer.
2886 LOCK(peer.m_headers_sync_mutex);
2887 if (peer.m_headers_sync) {
2888 peer.m_headers_sync.reset(nullptr);
2889 LOCK(m_headers_presync_mutex);
2890 m_headers_presync_stats.erase(pfrom.GetId());
2891 }
2892 // A headers message with no headers cannot be an announcement, so assume
2893 // it is a response to our last getheaders request, if there is one.
2894 peer.m_last_getheaders_timestamp = {};
2895 return;
2896 }
2897 2898 // Before we do any processing, make sure these pass basic sanity checks.
2899 // We'll rely on headers having valid proof-of-work further down, as an
2900 // anti-DoS criteria (note: this check is required before passing any
2901 // headers into HeadersSyncState).
2902 if (!CheckHeadersPoW(headers, m_chainparams.GetConsensus(), peer)) {
2903 // Misbehaving() calls are handled within CheckHeadersPoW(), so we can
2904 // just return. (Note that even if a header is announced via compact
2905 // block, the header itself should be valid, so this type of error can
2906 // always be punished.)
2907 return;
2908 }
2909 2910 const CBlockIndex *pindexLast = nullptr;
2911 2912 // We'll set already_validated_work to true if these headers are
2913 // successfully processed as part of a low-work headers sync in progress
2914 // (either in PRESYNC or REDOWNLOAD phase).
2915 // If true, this will mean that any headers returned to us (ie during
2916 // REDOWNLOAD) can be validated without further anti-DoS checks.
2917 bool already_validated_work = false;
2918 2919 // If we're in the middle of headers sync, let it do its magic.
2920 bool have_headers_sync = false;
2921 {
2922 LOCK(peer.m_headers_sync_mutex);
2923 2924 already_validated_work = IsContinuationOfLowWorkHeadersSync(peer, pfrom, headers);
2925 2926 // The headers we passed in may have been:
2927 // - untouched, perhaps if no headers-sync was in progress, or some
2928 // failure occurred
2929 // - erased, such as if the headers were successfully processed and no
2930 // additional headers processing needs to take place (such as if we
2931 // are still in PRESYNC)
2932 // - replaced with headers that are now ready for validation, such as
2933 // during the REDOWNLOAD phase of a low-work headers sync.
2934 // So just check whether we still have headers that we need to process,
2935 // or not.
2936 if (headers.empty()) {
2937 return;
2938 }
2939 2940 have_headers_sync = !!peer.m_headers_sync;
2941 }
2942 2943 // Do these headers connect to something in our block index?
2944 const CBlockIndex *chain_start_header{WITH_LOCK(::cs_main, return m_chainman.m_blockman.LookupBlockIndex(headers[0].hashPrevBlock))};
2945 bool headers_connect_blockindex{chain_start_header != nullptr};
2946 2947 if (!headers_connect_blockindex) {
2948 // This could be a BIP 130 block announcement, use
2949 // special logic for handling headers that don't connect, as this
2950 // could be benign.
2951 HandleUnconnectingHeaders(pfrom, peer, headers);
2952 return;
2953 }
2954 2955 // If headers connect, assume that this is in response to any outstanding getheaders
2956 // request we may have sent, and clear out the time of our last request. Non-connecting
2957 // headers cannot be a response to a getheaders request.
2958 peer.m_last_getheaders_timestamp = {};
2959 2960 // If the headers we received are already in memory and an ancestor of
2961 // m_best_header or our tip, skip anti-DoS checks. These headers will not
2962 // use any more memory (and we are not leaking information that could be
2963 // used to fingerprint us).
2964 const CBlockIndex *last_received_header{nullptr};
2965 {
2966 LOCK(cs_main);
2967 last_received_header = m_chainman.m_blockman.LookupBlockIndex(headers.back().GetHash());
2968 if (IsAncestorOfBestHeaderOrTip(last_received_header)) {
2969 already_validated_work = true;
2970 }
2971 }
2972 2973 // If our peer has NetPermissionFlags::NoBan privileges, then bypass our
2974 // anti-DoS logic (this saves bandwidth when we connect to a trusted peer
2975 // on startup).
2976 if (pfrom.HasPermission(NetPermissionFlags::NoBan)) {
2977 already_validated_work = true;
2978 }
2979 2980 // At this point, the headers connect to something in our block index.
2981 // Do anti-DoS checks to determine if we should process or store for later
2982 // processing.
2983 if (!already_validated_work && TryLowWorkHeadersSync(peer, pfrom,
2984 chain_start_header, headers)) {
2985 // If we successfully started a low-work headers sync, then there
2986 // should be no headers to process any further.
2987 Assume(headers.empty());
2988 return;
2989 }
2990 2991 // At this point, we have a set of headers with sufficient work on them
2992 // which can be processed.
2993 2994 // If we don't have the last header, then this peer will have given us
2995 // something new (if these headers are valid).
2996 bool received_new_header{last_received_header == nullptr};
2997 2998 // Now process all the headers.
2999 BlockValidationState state;
3000 if (!m_chainman.ProcessNewBlockHeaders(headers, /*min_pow_checked=*/true, state, &pindexLast)) {
3001 if (state.IsInvalid()) {
3002 MaybePunishNodeForBlock(pfrom.GetId(), state, via_compact_block, "invalid header received");
3003 return;
3004 }
3005 }
3006 assert(pindexLast);
3007 3008 // Consider fetching more headers if we are not using our headers-sync mechanism.
3009 if (nCount == m_opts.max_headers_result && !have_headers_sync) {
3010 // Headers message had its maximum size; the peer may have more headers.
3011 if (MaybeSendGetHeaders(pfrom, GetLocator(pindexLast), peer)) {
3012 LogDebug(BCLog::NET, "more getheaders (%d) to end to peer=%d (startheight:%d)\n",
3013 pindexLast->nHeight, pfrom.GetId(), peer.m_starting_height);
3014 }
3015 }
3016 3017 UpdatePeerStateForReceivedHeaders(pfrom, peer, *pindexLast, received_new_header, nCount == m_opts.max_headers_result);
3018 3019 // Consider immediately downloading blocks.
3020 HeadersDirectFetchBlocks(pfrom, peer, *pindexLast);
3021 3022 return;
3023 }
3024 3025 std::optional<node::PackageToValidate> PeerManagerImpl::ProcessInvalidTx(NodeId nodeid, const CTransactionRef& ptx, const TxValidationState& state,
3026 bool first_time_failure)
3027 {
3028 AssertLockNotHeld(m_peer_mutex);
3029 AssertLockHeld(g_msgproc_mutex);
3030 AssertLockHeld(m_tx_download_mutex);
3031 3032 PeerRef peer{GetPeerRef(nodeid)};
3033 3034 LogDebug(BCLog::MEMPOOLREJ, "%s (wtxid=%s) from peer=%d was not accepted: %s\n",
3035 ptx->GetHash().ToString(),
3036 ptx->GetWitnessHash().ToString(),
3037 nodeid,
3038 state.ToString());
3039 3040 const auto& [add_extra_compact_tx, unique_parents, package_to_validate] = m_txdownloadman.MempoolRejectedTx(ptx, state, nodeid, first_time_failure);
3041 3042 const size_t tx_dynamic_usage{RecursiveDynamicUsage(*ptx)};
3043 if (add_extra_compact_tx && tx_dynamic_usage < BLOCK_RECONSTRUCTION_EXTRA_TXN_PER_TXN_SIZE_LIMIT) {
3044 AddToCompactExtraTransactions(ptx, tx_dynamic_usage);
3045 }
3046 for (const Txid& parent_txid : unique_parents) {
3047 if (peer) AddKnownTx(*peer, parent_txid);
3048 }
3049 3050 return package_to_validate;
3051 }
3052 3053 void PeerManagerImpl::ProcessValidTx(NodeId nodeid, const CTransactionRef& tx, const std::list<CTransactionRef>& replaced_transactions)
3054 {
3055 AssertLockNotHeld(m_peer_mutex);
3056 AssertLockHeld(g_msgproc_mutex);
3057 AssertLockHeld(m_tx_download_mutex);
3058 3059 m_txdownloadman.MempoolAcceptedTx(tx);
3060 3061 LogDebug(BCLog::MEMPOOL, "AcceptToMemoryPool: peer=%d: accepted %s (wtxid=%s) (poolsz %u txn, %u kB)\n",
3062 nodeid,
3063 tx->GetHash().ToString(),
3064 tx->GetWitnessHash().ToString(),
3065 m_mempool.size(), m_mempool.DynamicMemoryUsage() / 1000);
3066 3067 RelayTransaction(tx->GetHash(), tx->GetWitnessHash());
3068 3069 for (const CTransactionRef& removedTx : replaced_transactions) {
3070 const size_t tx_dynamic_usage{RecursiveDynamicUsage(*removedTx)};
3071 AddToCompactExtraTransactions(removedTx, tx_dynamic_usage);
3072 }
3073 }
3074 3075 void PeerManagerImpl::ProcessPackageResult(const node::PackageToValidate& package_to_validate, const PackageMempoolAcceptResult& package_result)
3076 {
3077 AssertLockNotHeld(m_peer_mutex);
3078 AssertLockHeld(g_msgproc_mutex);
3079 AssertLockHeld(m_tx_download_mutex);
3080 3081 const auto& package = package_to_validate.m_txns;
3082 const auto& senders = package_to_validate.m_senders;
3083 3084 if (package_result.m_state.IsInvalid()) {
3085 m_txdownloadman.MempoolRejectedPackage(package);
3086 }
3087 // We currently only expect to process 1-parent-1-child packages. Remove if this changes.
3088 if (!Assume(package.size() == 2)) return;
3089 3090 // Iterate backwards to erase in-package descendants from the orphanage before they become
3091 // relevant in AddChildrenToWorkSet.
3092 auto package_iter = package.rbegin();
3093 auto senders_iter = senders.rbegin();
3094 while (package_iter != package.rend()) {
3095 const auto& tx = *package_iter;
3096 const NodeId nodeid = *senders_iter;
3097 const auto it_result{package_result.m_tx_results.find(tx->GetWitnessHash())};
3098 3099 // It is not guaranteed that a result exists for every transaction.
3100 if (it_result != package_result.m_tx_results.end()) {
3101 const auto& tx_result = it_result->second;
3102 switch (tx_result.m_result_type) {
3103 case MempoolAcceptResult::ResultType::VALID:
3104 {
3105 ProcessValidTx(nodeid, tx, tx_result.m_replaced_transactions);
3106 break;
3107 }
3108 case MempoolAcceptResult::ResultType::INVALID:
3109 case MempoolAcceptResult::ResultType::DIFFERENT_WITNESS:
3110 {
3111 // Don't add to vExtraTxnForCompact, as these transactions should have already been
3112 // added there when added to the orphanage or rejected for TX_RECONSIDERABLE.
3113 // This should be updated if package submission is ever used for transactions
3114 // that haven't already been validated before.
3115 ProcessInvalidTx(nodeid, tx, tx_result.m_state, /*first_time_failure=*/false);
3116 break;
3117 }
3118 case MempoolAcceptResult::ResultType::MEMPOOL_ENTRY:
3119 {
3120 // AlreadyHaveTx() should be catching transactions that are already in mempool.
3121 Assume(false);
3122 break;
3123 }
3124 }
3125 }
3126 package_iter++;
3127 senders_iter++;
3128 }
3129 }
3130 3131 bool PeerManagerImpl::ProcessOrphanTx(Peer& peer)
3132 {
3133 AssertLockHeld(g_msgproc_mutex);
3134 LOCK2(::cs_main, m_tx_download_mutex);
3135 3136 CTransactionRef porphanTx = nullptr;
3137 3138 while (CTransactionRef porphanTx = m_txdownloadman.GetTxToReconsider(peer.m_id)) {
3139 const MempoolAcceptResult result = m_chainman.ProcessTransaction(porphanTx);
3140 const TxValidationState& state = result.m_state;
3141 const Txid& orphanHash = porphanTx->GetHash();
3142 const Wtxid& orphan_wtxid = porphanTx->GetWitnessHash();
3143 3144 if (result.m_result_type == MempoolAcceptResult::ResultType::VALID) {
3145 LogDebug(BCLog::TXPACKAGES, " accepted orphan tx %s (wtxid=%s)\n", orphanHash.ToString(), orphan_wtxid.ToString());
3146 ProcessValidTx(peer.m_id, porphanTx, result.m_replaced_transactions);
3147 return true;
3148 } else if (state.GetResult() != TxValidationResult::TX_MISSING_INPUTS) {
3149 LogDebug(BCLog::TXPACKAGES, " invalid orphan tx %s (wtxid=%s) from peer=%d. %s\n",
3150 orphanHash.ToString(),
3151 orphan_wtxid.ToString(),
3152 peer.m_id,
3153 state.ToString());
3154 3155 if (Assume(state.IsInvalid() &&
3156 state.GetResult() != TxValidationResult::TX_UNKNOWN &&
3157 state.GetResult() != TxValidationResult::TX_NO_MEMPOOL &&
3158 state.GetResult() != TxValidationResult::TX_RESULT_UNSET)) {
3159 ProcessInvalidTx(peer.m_id, porphanTx, state, /*first_time_failure=*/false);
3160 }
3161 return true;
3162 }
3163 }
3164 3165 return false;
3166 }
3167 3168 bool PeerManagerImpl::PrepareBlockFilterRequest(CNode& node, Peer& peer,
3169 BlockFilterType filter_type, uint32_t start_height,
3170 const uint256& stop_hash, uint32_t max_height_diff,
3171 const CBlockIndex*& stop_index,
3172 BlockFilterIndex*& filter_index)
3173 {
3174 const bool supported_filter_type =
3175 (filter_type == BlockFilterType::BASIC &&
3176 (peer.m_our_services & NODE_COMPACT_FILTERS));
3177 if (!supported_filter_type) {
3178 LogDebug(BCLog::NET, "peer requested unsupported block filter type: %d, %s\n",
3179 static_cast<uint8_t>(filter_type), node.DisconnectMsg(fLogIPs));
3180 node.fDisconnect = true;
3181 return false;
3182 }
3183 3184 {
3185 LOCK(cs_main);
3186 stop_index = m_chainman.m_blockman.LookupBlockIndex(stop_hash);
3187 3188 // Check that the stop block exists and the peer would be allowed to fetch it.
3189 if (!stop_index || !BlockRequestAllowed(stop_index)) {
3190 LogDebug(BCLog::NET, "peer requested invalid block hash: %s, %s\n",
3191 stop_hash.ToString(), node.DisconnectMsg(fLogIPs));
3192 node.fDisconnect = true;
3193 return false;
3194 }
3195 }
3196 3197 uint32_t stop_height = stop_index->nHeight;
3198 if (start_height > stop_height) {
3199 LogDebug(BCLog::NET, "peer sent invalid getcfilters/getcfheaders with "
3200 "start height %d and stop height %d, %s\n",
3201 start_height, stop_height, node.DisconnectMsg(fLogIPs));
3202 node.fDisconnect = true;
3203 return false;
3204 }
3205 if (stop_height - start_height >= max_height_diff) {
3206 LogDebug(BCLog::NET, "peer requested too many cfilters/cfheaders: %d / %d, %s\n",
3207 stop_height - start_height + 1, max_height_diff, node.DisconnectMsg(fLogIPs));
3208 node.fDisconnect = true;
3209 return false;
3210 }
3211 3212 filter_index = GetBlockFilterIndex(filter_type);
3213 if (!filter_index) {
3214 LogDebug(BCLog::NET, "Filter index for supported type %s not found\n", BlockFilterTypeName(filter_type));
3215 return false;
3216 }
3217 3218 return true;
3219 }
3220 3221 void PeerManagerImpl::ProcessGetCFilters(CNode& node, Peer& peer, DataStream& vRecv)
3222 {
3223 uint8_t filter_type_ser;
3224 uint32_t start_height;
3225 uint256 stop_hash;
3226 3227 vRecv >> filter_type_ser >> start_height >> stop_hash;
3228 3229 const BlockFilterType filter_type = static_cast<BlockFilterType>(filter_type_ser);
3230 3231 const CBlockIndex* stop_index;
3232 BlockFilterIndex* filter_index;
3233 if (!PrepareBlockFilterRequest(node, peer, filter_type, start_height, stop_hash,
3234 MAX_GETCFILTERS_SIZE, stop_index, filter_index)) {
3235 return;
3236 }
3237 3238 std::vector<BlockFilter> filters;
3239 if (!filter_index->LookupFilterRange(start_height, stop_index, filters)) {
3240 LogDebug(BCLog::NET, "Failed to find block filter 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 for (const auto& filter : filters) {
3246 MakeAndPushMessage(node, NetMsgType::CFILTER, filter);
3247 }
3248 }
3249 3250 void PeerManagerImpl::ProcessGetCFHeaders(CNode& node, Peer& peer, DataStream& vRecv)
3251 {
3252 uint8_t filter_type_ser;
3253 uint32_t start_height;
3254 uint256 stop_hash;
3255 3256 vRecv >> filter_type_ser >> start_height >> stop_hash;
3257 3258 const BlockFilterType filter_type = static_cast<BlockFilterType>(filter_type_ser);
3259 3260 const CBlockIndex* stop_index;
3261 BlockFilterIndex* filter_index;
3262 if (!PrepareBlockFilterRequest(node, peer, filter_type, start_height, stop_hash,
3263 MAX_GETCFHEADERS_SIZE, stop_index, filter_index)) {
3264 return;
3265 }
3266 3267 uint256 prev_header;
3268 if (start_height > 0) {
3269 const CBlockIndex* const prev_block =
3270 stop_index->GetAncestor(static_cast<int>(start_height - 1));
3271 if (!filter_index->LookupFilterHeader(prev_block, prev_header)) {
3272 LogDebug(BCLog::NET, "Failed to find block filter header in index: filter_type=%s, block_hash=%s\n",
3273 BlockFilterTypeName(filter_type), prev_block->GetBlockHash().ToString());
3274 return;
3275 }
3276 }
3277 3278 std::vector<uint256> filter_hashes;
3279 if (!filter_index->LookupFilterHashRange(start_height, stop_index, filter_hashes)) {
3280 LogDebug(BCLog::NET, "Failed to find block filter hashes in index: filter_type=%s, start_height=%d, stop_hash=%s\n",
3281 BlockFilterTypeName(filter_type), start_height, stop_hash.ToString());
3282 return;
3283 }
3284 3285 MakeAndPushMessage(node, NetMsgType::CFHEADERS,
3286 filter_type_ser,
3287 stop_index->GetBlockHash(),
3288 prev_header,
3289 filter_hashes);
3290 }
3291 3292 void PeerManagerImpl::ProcessGetCFCheckPt(CNode& node, Peer& peer, DataStream& vRecv)
3293 {
3294 uint8_t filter_type_ser;
3295 uint256 stop_hash;
3296 3297 vRecv >> filter_type_ser >> stop_hash;
3298 3299 const BlockFilterType filter_type = static_cast<BlockFilterType>(filter_type_ser);
3300 3301 const CBlockIndex* stop_index;
3302 BlockFilterIndex* filter_index;
3303 if (!PrepareBlockFilterRequest(node, peer, filter_type, /*start_height=*/0, stop_hash,
3304 /*max_height_diff=*/std::numeric_limits<uint32_t>::max(),
3305 stop_index, filter_index)) {
3306 return;
3307 }
3308 3309 std::vector<uint256> headers(stop_index->nHeight / CFCHECKPT_INTERVAL);
3310 3311 // Populate headers.
3312 const CBlockIndex* block_index = stop_index;
3313 for (int i = headers.size() - 1; i >= 0; i--) {
3314 int height = (i + 1) * CFCHECKPT_INTERVAL;
3315 block_index = block_index->GetAncestor(height);
3316 3317 if (!filter_index->LookupFilterHeader(block_index, headers[i])) {
3318 LogDebug(BCLog::NET, "Failed to find block filter header in index: filter_type=%s, block_hash=%s\n",
3319 BlockFilterTypeName(filter_type), block_index->GetBlockHash().ToString());
3320 return;
3321 }
3322 }
3323 3324 MakeAndPushMessage(node, NetMsgType::CFCHECKPT,
3325 filter_type_ser,
3326 stop_index->GetBlockHash(),
3327 headers);
3328 }
3329 3330 void PeerManagerImpl::ProcessBlock(CNode& node, const std::shared_ptr<const CBlock>& block, bool force_processing, bool min_pow_checked)
3331 {
3332 bool new_block{false};
3333 m_chainman.ProcessNewBlock(block, force_processing, min_pow_checked, &new_block);
3334 if (new_block) {
3335 node.m_last_block_time = GetTime<std::chrono::seconds>();
3336 // In case this block came from a different peer than we requested
3337 // from, we can erase the block request now anyway (as we just stored
3338 // this block to disk).
3339 LOCK(cs_main);
3340 RemoveBlockRequest(block->GetHash(), std::nullopt);
3341 } else {
3342 LOCK(cs_main);
3343 mapBlockSource.erase(block->GetHash());
3344 }
3345 }
3346 3347 void PeerManagerImpl::ProcessCompactBlockTxns(CNode& pfrom, Peer& peer, const BlockTransactions& block_transactions)
3348 {
3349 std::shared_ptr<CBlock> pblock = std::make_shared<CBlock>();
3350 bool fBlockRead{false};
3351 {
3352 LOCK(cs_main);
3353 3354 auto range_flight = mapBlocksInFlight.equal_range(block_transactions.blockhash);
3355 size_t already_in_flight = std::distance(range_flight.first, range_flight.second);
3356 bool requested_block_from_this_peer{false};
3357 3358 // Multimap ensures ordering of outstanding requests. It's either empty or first in line.
3359 bool first_in_flight = already_in_flight == 0 || (range_flight.first->second.first == pfrom.GetId());
3360 3361 while (range_flight.first != range_flight.second) {
3362 auto [node_id, block_it] = range_flight.first->second;
3363 if (node_id == pfrom.GetId() && block_it->partialBlock) {
3364 requested_block_from_this_peer = true;
3365 break;
3366 }
3367 range_flight.first++;
3368 }
3369 3370 if (!requested_block_from_this_peer) {
3371 LogDebug(BCLog::NET, "Peer %d sent us block transactions for block we weren't expecting\n", pfrom.GetId());
3372 return;
3373 }
3374 3375 PartiallyDownloadedBlock& partialBlock = *range_flight.first->second.second->partialBlock;
3376 3377 if (partialBlock.header.IsNull()) {
3378 // It is possible for the header to be empty if a previous call to FillBlock wiped the header, but left
3379 // the PartiallyDownloadedBlock pointer around (i.e. did not call RemoveBlockRequest). In this case, we
3380 // should not call LookupBlockIndex below.
3381 RemoveBlockRequest(block_transactions.blockhash, pfrom.GetId());
3382 Misbehaving(peer, "previous compact block reconstruction attempt failed");
3383 LogDebug(BCLog::NET, "Peer %d sent compact block transactions multiple times", pfrom.GetId());
3384 return;
3385 }
3386 3387 // We should not have gotten this far in compact block processing unless it's attached to a known header
3388 const CBlockIndex* prev_block{Assume(m_chainman.m_blockman.LookupBlockIndex(partialBlock.header.hashPrevBlock))};
3389 ReadStatus status = partialBlock.FillBlock(*pblock, block_transactions.txn,
3390 /*segwit_active=*/DeploymentActiveAfter(prev_block, m_chainman, Consensus::DEPLOYMENT_SEGWIT));
3391 if (status == READ_STATUS_INVALID) {
3392 RemoveBlockRequest(block_transactions.blockhash, pfrom.GetId()); // Reset in-flight state in case Misbehaving does not result in a disconnect
3393 Misbehaving(peer, "invalid compact block/non-matching block transactions");
3394 return;
3395 } else if (status == READ_STATUS_FAILED) {
3396 if (first_in_flight) {
3397 // Might have collided, fall back to getdata now :(
3398 // We keep the failed partialBlock to disallow processing another compact block announcement from the same
3399 // peer for the same block. We let the full block download below continue under the same m_downloading_since
3400 // timer.
3401 std::vector<CInv> invs;
3402 invs.emplace_back(MSG_BLOCK | GetFetchFlags(peer), block_transactions.blockhash);
3403 MakeAndPushMessage(pfrom, NetMsgType::GETDATA, invs);
3404 } else {
3405 RemoveBlockRequest(block_transactions.blockhash, pfrom.GetId());
3406 LogDebug(BCLog::NET, "Peer %d sent us a compact block but it failed to reconstruct, waiting on first download to complete\n", pfrom.GetId());
3407 return;
3408 }
3409 } else {
3410 // Block is okay for further processing
3411 RemoveBlockRequest(block_transactions.blockhash, pfrom.GetId()); // it is now an empty pointer
3412 fBlockRead = true;
3413 // mapBlockSource is used for potentially punishing peers and
3414 // updating which peers send us compact blocks, so the race
3415 // between here and cs_main in ProcessNewBlock is fine.
3416 // BIP 152 permits peers to relay compact blocks after validating
3417 // the header only; we should not punish peers if the block turns
3418 // out to be invalid.
3419 mapBlockSource.emplace(block_transactions.blockhash, std::make_pair(pfrom.GetId(), false));
3420 }
3421 } // Don't hold cs_main when we call into ProcessNewBlock
3422 if (fBlockRead) {
3423 // Since we requested this block (it was in mapBlocksInFlight), force it to be processed,
3424 // even if it would not be a candidate for new tip (missing previous block, chain not long enough, etc)
3425 // This bypasses some anti-DoS logic in AcceptBlock (eg to prevent
3426 // disk-space attacks), but this should be safe due to the
3427 // protections in the compact block handler -- see related comment
3428 // in compact block optimistic reconstruction handling.
3429 ProcessBlock(pfrom, pblock, /*force_processing=*/true, /*min_pow_checked=*/true);
3430 }
3431 return;
3432 }
3433 3434 void PeerManagerImpl::ProcessMessage(CNode& pfrom, const std::string& msg_type, DataStream& vRecv,
3435 const std::chrono::microseconds time_received,
3436 const std::atomic<bool>& interruptMsgProc)
3437 {
3438 AssertLockHeld(g_msgproc_mutex);
3439 3440 LogDebug(BCLog::NET, "received: %s (%u bytes) peer=%d\n", SanitizeString(msg_type), vRecv.size(), pfrom.GetId());
3441 3442 PeerRef peer = GetPeerRef(pfrom.GetId());
3443 if (peer == nullptr) return;
3444 3445 if (msg_type == NetMsgType::VERSION) {
3446 if (pfrom.nVersion != 0) {
3447 LogDebug(BCLog::NET, "redundant version message from peer=%d\n", pfrom.GetId());
3448 return;
3449 }
3450 3451 int64_t nTime;
3452 CService addrMe;
3453 uint64_t nNonce = 1;
3454 ServiceFlags nServices;
3455 int nVersion;
3456 std::string cleanSubVer;
3457 int starting_height = -1;
3458 bool fRelay = true;
3459 3460 vRecv >> nVersion >> Using<CustomUintFormatter<8>>(nServices) >> nTime;
3461 if (nTime < 0) {
3462 nTime = 0;
3463 }
3464 vRecv.ignore(8); // Ignore the addrMe service bits sent by the peer
3465 vRecv >> CNetAddr::V1(addrMe);
3466 if (!pfrom.IsInboundConn())
3467 {
3468 // Overwrites potentially existing services. In contrast to this,
3469 // unvalidated services received via gossip relay in ADDR/ADDRV2
3470 // messages are only ever added but cannot replace existing ones.
3471 m_addrman.SetServices(pfrom.addr, nServices);
3472 }
3473 if (pfrom.ExpectServicesFromConn() && !HasAllDesirableServiceFlags(nServices))
3474 {
3475 LogDebug(BCLog::NET, "peer does not offer the expected services (%08x offered, %08x expected), %s\n",
3476 nServices,
3477 GetDesirableServiceFlags(nServices),
3478 pfrom.DisconnectMsg(fLogIPs));
3479 pfrom.fDisconnect = true;
3480 return;
3481 }
3482 3483 if (nVersion < MIN_PEER_PROTO_VERSION) {
3484 // disconnect from peers older than this proto version
3485 LogDebug(BCLog::NET, "peer using obsolete version %i, %s\n", nVersion, pfrom.DisconnectMsg(fLogIPs));
3486 pfrom.fDisconnect = true;
3487 return;
3488 }
3489 3490 if (!vRecv.empty()) {
3491 // The version message includes information about the sending node which we don't use:
3492 // - 8 bytes (service bits)
3493 // - 16 bytes (ipv6 address)
3494 // - 2 bytes (port)
3495 vRecv.ignore(26);
3496 vRecv >> nNonce;
3497 }
3498 if (!vRecv.empty()) {
3499 std::string strSubVer;
3500 vRecv >> LIMITED_STRING(strSubVer, MAX_SUBVERSION_LENGTH);
3501 cleanSubVer = SanitizeString(strSubVer, SAFE_CHARS_PRINTABLE);
3502 }
3503 if (!vRecv.empty()) {
3504 vRecv >> starting_height;
3505 }
3506 if (!vRecv.empty())
3507 vRecv >> fRelay;
3508 // Disconnect if we connected to ourself
3509 if (pfrom.IsInboundConn() && !m_connman.CheckIncomingNonce(nNonce))
3510 {
3511 LogPrintf("connected to self at %s, disconnecting\n", pfrom.addr.ToStringAddrPort());
3512 pfrom.fDisconnect = true;
3513 return;
3514 }
3515 3516 if (pfrom.IsInboundConn() && addrMe.IsRoutable())
3517 {
3518 SeenLocal(addrMe);
3519 }
3520 3521 // Inbound peers send us their version message when they connect.
3522 // We send our version message in response.
3523 if (pfrom.IsInboundConn()) {
3524 PushNodeVersion(pfrom, *peer);
3525 }
3526 3527 // Change version
3528 const int greatest_common_version = std::min(nVersion, PROTOCOL_VERSION);
3529 pfrom.SetCommonVersion(greatest_common_version);
3530 {
3531 LOCK(pfrom.m_subver_mutex);
3532 pfrom.cleanSubVer = cleanSubVer;
3533 }
3534 pfrom.nVersion = nVersion;
3535 3536 if (greatest_common_version >= WTXID_RELAY_VERSION) {
3537 MakeAndPushMessage(pfrom, NetMsgType::WTXIDRELAY);
3538 }
3539 3540 // Signal ADDRv2 support (BIP155).
3541 if (greatest_common_version >= 70016) {
3542 // BIP155 defines addrv2 and sendaddrv2 for all protocol versions, but some
3543 // implementations reject messages they don't know. As a courtesy, don't send
3544 // it to nodes with a version before 70016, as no software is known to support
3545 // BIP155 that doesn't announce at least that protocol version number.
3546 MakeAndPushMessage(pfrom, NetMsgType::SENDADDRV2);
3547 }
3548 3549 pfrom.m_has_all_wanted_services = HasAllDesirableServiceFlags(nServices);
3550 // BIP-110: Allow up to 2 non-BIP110 outbound peers.
3551 if (pfrom.ExpectServicesFromConn() && !(nServices & NODE_REDUCED_DATA)) {
3552 if (m_num_non_bip110_outbound >= m_opts.maxstaleoutbound) {
3553 LogDebug(BCLog::NET, "peer lacks NODE_REDUCED_DATA and already have %u non-BIP110 outbound peers (limit %u), %s\n",
3554 m_num_non_bip110_outbound,
3555 m_opts.maxstaleoutbound,
3556 pfrom.DisconnectMsg(fLogIPs));
3557 pfrom.fDisconnect = true;
3558 return;
3559 }
3560 ++m_num_non_bip110_outbound;
3561 pfrom.m_is_non_bip110_outbound = true;
3562 LogDebug(BCLog::NET, "connected to non-BIP110 outbound peer (%u/%u), %s\n",
3563 m_num_non_bip110_outbound.load(),
3564 m_opts.maxstaleoutbound,
3565 pfrom.ConnectionTypeAsString());
3566 }
3567 peer->m_their_services = nServices;
3568 pfrom.SetAddrLocal(addrMe);
3569 peer->m_starting_height = starting_height;
3570 3571 // Only initialize the Peer::TxRelay m_relay_txs data structure if:
3572 // - this isn't an outbound block-relay-only connection, and
3573 // - this isn't an outbound feeler connection, and
3574 // - fRelay=true (the peer wishes to receive transaction announcements)
3575 // or we're offering NODE_BLOOM to this peer. NODE_BLOOM means that
3576 // the peer may turn on transaction relay later.
3577 if (!pfrom.IsBlockOnlyConn() &&
3578 !pfrom.IsFeelerConn() &&
3579 (fRelay || (peer->m_our_services & NODE_BLOOM))) {
3580 auto* const tx_relay = peer->SetTxRelay();
3581 {
3582 LOCK(tx_relay->m_bloom_filter_mutex);
3583 tx_relay->m_relay_txs = fRelay; // set to true after we get the first filter* message
3584 }
3585 if (fRelay) pfrom.m_relays_txs = true;
3586 }
3587 3588 if (greatest_common_version >= WTXID_RELAY_VERSION && m_txreconciliation) {
3589 // Per BIP-330, we announce txreconciliation support if:
3590 // - protocol version per the peer's VERSION message supports WTXID_RELAY;
3591 // - transaction relay is supported per the peer's VERSION message
3592 // - this is not a block-relay-only connection and not a feeler
3593 // - this is not an addr fetch connection;
3594 // - we are not in -blocksonly mode.
3595 const auto* tx_relay = peer->GetTxRelay();
3596 if (tx_relay && WITH_LOCK(tx_relay->m_bloom_filter_mutex, return tx_relay->m_relay_txs) &&
3597 !pfrom.IsAddrFetchConn() && !m_opts.ignore_incoming_txs) {
3598 const uint64_t recon_salt = m_txreconciliation->PreRegisterPeer(pfrom.GetId());
3599 MakeAndPushMessage(pfrom, NetMsgType::SENDTXRCNCL,
3600 TXRECONCILIATION_VERSION, recon_salt);
3601 }
3602 }
3603 3604 MakeAndPushMessage(pfrom, NetMsgType::VERACK);
3605 3606 // Potentially mark this peer as a preferred download peer.
3607 {
3608 LOCK(cs_main);
3609 CNodeState* state = State(pfrom.GetId());
3610 state->fPreferredDownload = (!pfrom.IsInboundConn() || pfrom.HasPermission(NetPermissionFlags::NoBan)) && !pfrom.IsAddrFetchConn() && CanServeBlocks(*peer);
3611 m_num_preferred_download_peers += state->fPreferredDownload;
3612 }
3613 3614 // Attempt to initialize address relay for outbound peers and use result
3615 // to decide whether to send GETADDR, so that we don't send it to
3616 // inbound or outbound block-relay-only peers.
3617 bool send_getaddr{false};
3618 if (!pfrom.IsInboundConn()) {
3619 send_getaddr = SetupAddressRelay(pfrom, *peer);
3620 }
3621 if (send_getaddr) {
3622 // Do a one-time address fetch to help populate/update our addrman.
3623 // If we're starting up for the first time, our addrman may be pretty
3624 // empty, so this mechanism is important to help us connect to the network.
3625 // We skip this for block-relay-only peers. We want to avoid
3626 // potentially leaking addr information and we do not want to
3627 // indicate to the peer that we will participate in addr relay.
3628 MakeAndPushMessage(pfrom, NetMsgType::GETADDR);
3629 peer->m_getaddr_sent = true;
3630 // When requesting a getaddr, accept an additional MAX_ADDR_TO_SEND addresses in response
3631 // (bypassing the MAX_ADDR_PROCESSING_TOKEN_BUCKET limit).
3632 peer->m_addr_token_bucket += MAX_ADDR_TO_SEND;
3633 }
3634 3635 if (!pfrom.IsInboundConn()) {
3636 // For non-inbound connections, we update the addrman to record
3637 // connection success so that addrman will have an up-to-date
3638 // notion of which peers are online and available.
3639 //
3640 // While we strive to not leak information about block-relay-only
3641 // connections via the addrman, not moving an address to the tried
3642 // table is also potentially detrimental because new-table entries
3643 // are subject to eviction in the event of addrman collisions. We
3644 // mitigate the information-leak by never calling
3645 // AddrMan::Connected() on block-relay-only peers; see
3646 // FinalizeNode().
3647 //
3648 // This moves an address from New to Tried table in Addrman,
3649 // resolves tried-table collisions, etc.
3650 m_addrman.Good(pfrom.addr);
3651 }
3652 3653 const auto mapped_as{m_connman.GetMappedAS(pfrom.addr)};
3654 LogDebug(BCLog::NET, "receive version message: %s: version %d, blocks=%d, us=%s, txrelay=%d, peer=%d%s%s%s\n",
3655 SanitizeString(cleanSubVer, SAFE_CHARS_DEFAULT, true), pfrom.nVersion,
3656 peer->m_starting_height, addrMe.ToStringAddrPort(), fRelay, pfrom.GetId(),
3657 fLogIPs ? "," : "", pfrom.LogIP(fLogIPs),
3658 (mapped_as ? strprintf(", mapped_as=%d", mapped_as) : ""));
3659 3660 peer->m_time_offset = NodeSeconds{std::chrono::seconds{nTime}} - Now<NodeSeconds>();
3661 if (!pfrom.IsInboundConn()) {
3662 // Don't use timedata samples from inbound peers to make it
3663 // harder for others to create false warnings about our clock being out of sync.
3664 m_outbound_time_offsets.Add(peer->m_time_offset);
3665 m_outbound_time_offsets.WarnIfOutOfSync();
3666 }
3667 3668 // If the peer is old enough to have the old alert system, send it the final alert.
3669 if (greatest_common_version <= 70012) {
3670 constexpr auto finalAlert{"60010000000000000000000000ffffff7f00000000ffffff7ffeffff7f01ffffff7f00000000ffffff7f00ffffff7f002f555247454e543a20416c657274206b657920636f6d70726f6d697365642c2075706772616465207265717569726564004630440220653febd6410f470f6bae11cad19c48413becb1ac2c17f908fd0fd53bdc3abd5202206d0e9c96fe88d4a0f01ed9dedae2b6f9e00da94cad0fecaae66ecf689bf71b50"_hex};
3671 MakeAndPushMessage(pfrom, "alert", finalAlert);
3672 }
3673 3674 // Feeler connections exist only to verify if address is online.
3675 if (pfrom.IsFeelerConn()) {
3676 LogDebug(BCLog::NET, "feeler connection completed, %s\n", pfrom.DisconnectMsg(fLogIPs));
3677 pfrom.fDisconnect = true;
3678 }
3679 return;
3680 }
3681 3682 if (pfrom.nVersion == 0) {
3683 // Must have a version message before anything else
3684 LogDebug(BCLog::NET, "non-version message before version handshake. Message \"%s\" from peer=%d\n", SanitizeString(msg_type), pfrom.GetId());
3685 return;
3686 }
3687 3688 if (msg_type == NetMsgType::VERACK) {
3689 if (pfrom.fSuccessfullyConnected) {
3690 LogDebug(BCLog::NET, "ignoring redundant verack message from peer=%d\n", pfrom.GetId());
3691 return;
3692 }
3693 3694 // Log successful connections unconditionally for outbound, but not for inbound as those
3695 // can be triggered by an attacker at high rate.
3696 if (!pfrom.IsInboundConn() || LogAcceptCategory(BCLog::NET, BCLog::Level::Debug)) {
3697 const auto mapped_as{m_connman.GetMappedAS(pfrom.addr)};
3698 LogPrintf("New %s %s peer connected: version: %d, blocks=%d, peer=%d%s%s%s\n",
3699 pfrom.ConnectionTypeAsString(),
3700 TransportTypeAsString(pfrom.m_transport->GetInfo().transport_type),
3701 pfrom.nVersion.load(), peer->m_starting_height,
3702 pfrom.GetId(),
3703 fLogIPs ? "," : "", pfrom.LogIP(fLogIPs),
3704 (mapped_as ? strprintf(", mapped_as=%d", mapped_as) : ""));
3705 }
3706 3707 if (pfrom.GetCommonVersion() >= SHORT_IDS_BLOCKS_VERSION) {
3708 // Tell our peer we are willing to provide version 2 cmpctblocks.
3709 // However, we do not request new block announcements using
3710 // cmpctblock messages.
3711 // We send this to non-NODE NETWORK peers as well, because
3712 // they may wish to request compact blocks from us
3713 MakeAndPushMessage(pfrom, NetMsgType::SENDCMPCT, /*high_bandwidth=*/false, /*version=*/CMPCTBLOCKS_VERSION);
3714 }
3715 3716 if (m_txreconciliation) {
3717 if (!peer->m_wtxid_relay || !m_txreconciliation->IsPeerRegistered(pfrom.GetId())) {
3718 // We could have optimistically pre-registered/registered the peer. In that case,
3719 // we should forget about the reconciliation state here if this wasn't followed
3720 // by WTXIDRELAY (since WTXIDRELAY can't be announced later).
3721 m_txreconciliation->ForgetPeer(pfrom.GetId());
3722 }
3723 }
3724 3725 if (auto tx_relay = peer->GetTxRelay()) {
3726 // `TxRelay::m_tx_inventory_to_send` must be empty before the
3727 // version handshake is completed as
3728 // `TxRelay::m_next_inv_send_time` is first initialised in
3729 // `SendMessages` after the verack is received. Any transactions
3730 // received during the version handshake would otherwise
3731 // immediately be advertised without random delay, potentially
3732 // leaking the time of arrival to a spy.
3733 Assume(WITH_LOCK(
3734 tx_relay->m_tx_inventory_mutex,
3735 return tx_relay->m_tx_inventory_to_send.empty() &&
3736 tx_relay->m_next_inv_send_time == 0s));
3737 }
3738 3739 {
3740 LOCK2(::cs_main, m_tx_download_mutex);
3741 const CNodeState* state = State(pfrom.GetId());
3742 m_txdownloadman.ConnectedPeer(pfrom.GetId(), node::TxDownloadConnectionInfo {
3743 .m_preferred = state->fPreferredDownload,
3744 .m_relay_permissions = pfrom.HasPermission(NetPermissionFlags::Relay),
3745 .m_wtxid_relay = peer->m_wtxid_relay,
3746 });
3747 }
3748 3749 pfrom.fSuccessfullyConnected = true;
3750 return;
3751 }
3752 3753 if (msg_type == NetMsgType::SENDHEADERS) {
3754 peer->m_prefers_headers = true;
3755 return;
3756 }
3757 3758 if (msg_type == NetMsgType::SENDCMPCT) {
3759 bool sendcmpct_hb{false};
3760 uint64_t sendcmpct_version{0};
3761 vRecv >> sendcmpct_hb >> sendcmpct_version;
3762 3763 // Only support compact block relay with witnesses
3764 if (sendcmpct_version != CMPCTBLOCKS_VERSION) return;
3765 3766 LOCK(cs_main);
3767 CNodeState* nodestate = State(pfrom.GetId());
3768 nodestate->m_provides_cmpctblocks = true;
3769 nodestate->m_requested_hb_cmpctblocks = sendcmpct_hb;
3770 // save whether peer selects us as BIP152 high-bandwidth peer
3771 // (receiving sendcmpct(1) signals high-bandwidth, sendcmpct(0) low-bandwidth)
3772 pfrom.m_bip152_highbandwidth_from = sendcmpct_hb;
3773 return;
3774 }
3775 3776 // BIP339 defines feature negotiation of wtxidrelay, which must happen between
3777 // VERSION and VERACK to avoid relay problems from switching after a connection is up.
3778 if (msg_type == NetMsgType::WTXIDRELAY) {
3779 if (pfrom.fSuccessfullyConnected) {
3780 // Disconnect peers that send a wtxidrelay message after VERACK.
3781 LogDebug(BCLog::NET, "wtxidrelay received after verack, %s\n", pfrom.DisconnectMsg(fLogIPs));
3782 pfrom.fDisconnect = true;
3783 return;
3784 }
3785 if (pfrom.GetCommonVersion() >= WTXID_RELAY_VERSION) {
3786 if (!peer->m_wtxid_relay) {
3787 peer->m_wtxid_relay = true;
3788 m_wtxid_relay_peers++;
3789 } else {
3790 LogDebug(BCLog::NET, "ignoring duplicate wtxidrelay from peer=%d\n", pfrom.GetId());
3791 }
3792 } else {
3793 LogDebug(BCLog::NET, "ignoring wtxidrelay due to old common version=%d from peer=%d\n", pfrom.GetCommonVersion(), pfrom.GetId());
3794 }
3795 return;
3796 }
3797 3798 // BIP155 defines feature negotiation of addrv2 and sendaddrv2, which must happen
3799 // between VERSION and VERACK.
3800 if (msg_type == NetMsgType::SENDADDRV2) {
3801 if (pfrom.fSuccessfullyConnected) {
3802 // Disconnect peers that send a SENDADDRV2 message after VERACK.
3803 LogDebug(BCLog::NET, "sendaddrv2 received after verack, %s\n", pfrom.DisconnectMsg(fLogIPs));
3804 pfrom.fDisconnect = true;
3805 return;
3806 }
3807 peer->m_wants_addrv2 = true;
3808 return;
3809 }
3810 3811 // Received from a peer demonstrating readiness to announce transactions via reconciliations.
3812 // This feature negotiation must happen between VERSION and VERACK to avoid relay problems
3813 // from switching announcement protocols after the connection is up.
3814 if (msg_type == NetMsgType::SENDTXRCNCL) {
3815 if (!m_txreconciliation) {
3816 LogDebug(BCLog::NET, "sendtxrcncl from peer=%d ignored, as our node does not have txreconciliation enabled\n", pfrom.GetId());
3817 return;
3818 }
3819 3820 if (pfrom.fSuccessfullyConnected) {
3821 LogDebug(BCLog::NET, "sendtxrcncl received after verack, %s\n", pfrom.DisconnectMsg(fLogIPs));
3822 pfrom.fDisconnect = true;
3823 return;
3824 }
3825 3826 // Peer must not offer us reconciliations if we specified no tx relay support in VERSION.
3827 if (RejectIncomingTxs(pfrom)) {
3828 LogDebug(BCLog::NET, "sendtxrcncl received to which we indicated no tx relay, %s\n", pfrom.DisconnectMsg(fLogIPs));
3829 pfrom.fDisconnect = true;
3830 return;
3831 }
3832 3833 // Peer must not offer us reconciliations if they specified no tx relay support in VERSION.
3834 // This flag might also be false in other cases, but the RejectIncomingTxs check above
3835 // eliminates them, so that this flag fully represents what we are looking for.
3836 const auto* tx_relay = peer->GetTxRelay();
3837 if (!tx_relay || !WITH_LOCK(tx_relay->m_bloom_filter_mutex, return tx_relay->m_relay_txs)) {
3838 LogDebug(BCLog::NET, "sendtxrcncl received which indicated no tx relay to us, %s\n", pfrom.DisconnectMsg(fLogIPs));
3839 pfrom.fDisconnect = true;
3840 return;
3841 }
3842 3843 uint32_t peer_txreconcl_version;
3844 uint64_t remote_salt;
3845 vRecv >> peer_txreconcl_version >> remote_salt;
3846 3847 const ReconciliationRegisterResult result = m_txreconciliation->RegisterPeer(pfrom.GetId(), pfrom.IsInboundConn(),
3848 peer_txreconcl_version, remote_salt);
3849 switch (result) {
3850 case ReconciliationRegisterResult::NOT_FOUND:
3851 LogDebug(BCLog::NET, "Ignore unexpected txreconciliation signal from peer=%d\n", pfrom.GetId());
3852 break;
3853 case ReconciliationRegisterResult::SUCCESS:
3854 break;
3855 case ReconciliationRegisterResult::ALREADY_REGISTERED:
3856 LogDebug(BCLog::NET, "txreconciliation protocol violation (sendtxrcncl received from already registered peer), %s\n", pfrom.DisconnectMsg(fLogIPs));
3857 pfrom.fDisconnect = true;
3858 return;
3859 case ReconciliationRegisterResult::PROTOCOL_VIOLATION:
3860 LogDebug(BCLog::NET, "txreconciliation protocol violation, %s\n", pfrom.DisconnectMsg(fLogIPs));
3861 pfrom.fDisconnect = true;
3862 return;
3863 }
3864 return;
3865 }
3866 3867 if (!pfrom.fSuccessfullyConnected) {
3868 LogDebug(BCLog::NET, "Unsupported message \"%s\" prior to verack from peer=%d\n", SanitizeString(msg_type), pfrom.GetId());
3869 return;
3870 }
3871 3872 if (msg_type == NetMsgType::ADDR || msg_type == NetMsgType::ADDRV2) {
3873 const auto ser_params{
3874 msg_type == NetMsgType::ADDRV2 ?
3875 // Set V2 param so that the CNetAddr and CAddress
3876 // unserialize methods know that an address in v2 format is coming.
3877 CAddress::V2_NETWORK :
3878 CAddress::V1_NETWORK,
3879 };
3880 3881 unsigned int nCount = ReadCompactSize(vRecv);
3882 if (nCount > MAX_ADDR_TO_SEND) {
3883 Misbehaving(*peer, strprintf("%s message size = %u", msg_type, nCount));
3884 return;
3885 }
3886 3887 std::vector<CAddress> vAddr;
3888 vAddr.resize(nCount);
3889 3890 for (unsigned int n = 0; n < nCount; n++) {
3891 vRecv >> ser_params(vAddr[n]);
3892 }
3893 3894 if (!SetupAddressRelay(pfrom, *peer)) {
3895 LogDebug(BCLog::NET, "ignoring %s message from %s peer=%d\n", msg_type, pfrom.ConnectionTypeAsString(), pfrom.GetId());
3896 return;
3897 }
3898 3899 // Store the new addresses
3900 std::vector<CAddress> vAddrOk;
3901 const auto current_a_time{Now<NodeSeconds>()};
3902 3903 // Update/increment addr rate limiting bucket.
3904 const auto current_time{GetTime<std::chrono::microseconds>()};
3905 if (peer->m_addr_token_bucket < MAX_ADDR_PROCESSING_TOKEN_BUCKET) {
3906 // Don't increment bucket if it's already full
3907 const auto time_diff = std::max(current_time - peer->m_addr_token_timestamp, 0us);
3908 const double increment = Ticks<SecondsDouble>(time_diff) * MAX_ADDR_RATE_PER_SECOND;
3909 peer->m_addr_token_bucket = std::min<double>(peer->m_addr_token_bucket + increment, MAX_ADDR_PROCESSING_TOKEN_BUCKET);
3910 }
3911 peer->m_addr_token_timestamp = current_time;
3912 3913 const bool rate_limited = !pfrom.HasPermission(NetPermissionFlags::Addr);
3914 uint64_t num_proc = 0;
3915 uint64_t num_rate_limit = 0;
3916 std::shuffle(vAddr.begin(), vAddr.end(), m_rng);
3917 for (CAddress& addr : vAddr)
3918 {
3919 if (interruptMsgProc)
3920 return;
3921 3922 // Apply rate limiting.
3923 if (peer->m_addr_token_bucket < 1.0) {
3924 if (rate_limited) {
3925 ++num_rate_limit;
3926 continue;
3927 }
3928 } else {
3929 peer->m_addr_token_bucket -= 1.0;
3930 }
3931 // We only bother storing full nodes, though this may include
3932 // things which we would not make an outbound connection to, in
3933 // part because we may make feeler connections to them.
3934 if (!MayHaveUsefulAddressDB(addr.nServices) && !HasAllDesirableServiceFlags(addr.nServices))
3935 continue;
3936 3937 if (addr.nTime <= NodeSeconds{100000000s} || addr.nTime > current_a_time + 10min) {
3938 addr.nTime = current_a_time - 5 * 24h;
3939 }
3940 AddAddressKnown(*peer, addr);
3941 if (m_banman && (m_banman->IsDiscouraged(addr) || m_banman->IsBanned(addr))) {
3942 // Do not process banned/discouraged addresses beyond remembering we received them
3943 continue;
3944 }
3945 ++num_proc;
3946 const bool reachable{g_reachable_nets.Contains(addr)};
3947 if (addr.nTime > current_a_time - 10min && !peer->m_getaddr_sent && vAddr.size() <= 10 && addr.IsRoutable()) {
3948 // Relay to a limited number of other nodes
3949 RelayAddress(pfrom.GetId(), addr, reachable);
3950 }
3951 // Do not store addresses outside our network
3952 if (reachable) {
3953 vAddrOk.push_back(addr);
3954 }
3955 }
3956 peer->m_addr_processed += num_proc;
3957 peer->m_addr_rate_limited += num_rate_limit;
3958 LogDebug(BCLog::NET, "Received addr: %u addresses (%u processed, %u rate-limited) from peer=%d\n",
3959 vAddr.size(), num_proc, num_rate_limit, pfrom.GetId());
3960 3961 m_addrman.Add(vAddrOk, pfrom.addr, 2h);
3962 if (vAddr.size() < 1000) peer->m_getaddr_sent = false;
3963 3964 // AddrFetch: Require multiple addresses to avoid disconnecting on self-announcements
3965 if (pfrom.IsAddrFetchConn() && vAddr.size() > 1) {
3966 LogDebug(BCLog::NET, "addrfetch connection completed, %s\n", pfrom.DisconnectMsg(fLogIPs));
3967 pfrom.fDisconnect = true;
3968 }
3969 return;
3970 }
3971 3972 if (msg_type == NetMsgType::INV) {
3973 unsigned int nCount = ReadCompactSize(vRecv);
3974 if (nCount > MAX_INV_SZ) {
3975 Misbehaving(*peer, strprintf("inv message size = %u", nCount));
3976 return;
3977 }
3978 std::vector<CInv> vInv;
3979 vInv.resize(nCount);
3980 for (unsigned int n = 0; n < nCount; n++) {
3981 vRecv >> vInv[n];
3982 }
3983 3984 const bool reject_tx_invs{RejectIncomingTxs(pfrom)};
3985 3986 LOCK2(cs_main, m_tx_download_mutex);
3987 3988 const auto current_time{GetTime<std::chrono::microseconds>()};
3989 uint256* best_block{nullptr};
3990 3991 for (CInv& inv : vInv) {
3992 if (interruptMsgProc) return;
3993 3994 // Ignore INVs that don't match wtxidrelay setting.
3995 // Note that orphan parent fetching always uses MSG_TX GETDATAs regardless of the wtxidrelay setting.
3996 // This is fine as no INV messages are involved in that process.
3997 if (peer->m_wtxid_relay) {
3998 if (inv.IsMsgTx()) continue;
3999 } else {
4000 if (inv.IsMsgWtx()) continue;
4001 }
4002 4003 if (inv.IsMsgBlk()) {
4004 const bool fAlreadyHave = AlreadyHaveBlock(inv.hash);
4005 LogDebug(BCLog::NET, "got inv: %s %s peer=%d\n", inv.ToString(), fAlreadyHave ? "have" : "new", pfrom.GetId());
4006 4007 UpdateBlockAvailability(pfrom.GetId(), inv.hash);
4008 if (!fAlreadyHave && !m_chainman.m_blockman.LoadingBlocks() && !IsBlockRequested(inv.hash)) {
4009 // Headers-first is the primary method of announcement on
4010 // the network. If a node fell back to sending blocks by
4011 // inv, it may be for a re-org, or because we haven't
4012 // completed initial headers sync. The final block hash
4013 // provided should be the highest, so send a getheaders and
4014 // then fetch the blocks we need to catch up.
4015 best_block = &inv.hash;
4016 }
4017 } else if (inv.IsGenTxMsg()) {
4018 if (reject_tx_invs) {
4019 LogDebug(BCLog::NET, "transaction (%s) inv sent in violation of protocol, %s\n", inv.hash.ToString(), pfrom.DisconnectMsg(fLogIPs));
4020 pfrom.fDisconnect = true;
4021 return;
4022 }
4023 const GenTxid gtxid = ToGenTxid(inv);
4024 AddKnownTx(*peer, inv.hash);
4025 4026 if (!m_chainman.IsInitialBlockDownload()) {
4027 const bool fAlreadyHave{m_txdownloadman.AddTxAnnouncement(pfrom.GetId(), gtxid, current_time)};
4028 LogDebug(BCLog::NET, "got inv: %s %s peer=%d\n", inv.ToString(), fAlreadyHave ? "have" : "new", pfrom.GetId());
4029 }
4030 } else {
4031 LogDebug(BCLog::NET, "Unknown inv type \"%s\" received from peer=%d\n", inv.ToString(), pfrom.GetId());
4032 }
4033 }
4034 4035 if (best_block != nullptr) {
4036 // If we haven't started initial headers-sync with this peer, then
4037 // consider sending a getheaders now. On initial startup, there's a
4038 // reliability vs bandwidth tradeoff, where we are only trying to do
4039 // initial headers sync with one peer at a time, with a long
4040 // timeout (at which point, if the sync hasn't completed, we will
4041 // disconnect the peer and then choose another). In the meantime,
4042 // as new blocks are found, we are willing to add one new peer per
4043 // block to sync with as well, to sync quicker in the case where
4044 // our initial peer is unresponsive (but less bandwidth than we'd
4045 // use if we turned on sync with all peers).
4046 CNodeState& state{*Assert(State(pfrom.GetId()))};
4047 if (state.fSyncStarted || (!peer->m_inv_triggered_getheaders_before_sync && *best_block != m_last_block_inv_triggering_headers_sync)) {
4048 if (MaybeSendGetHeaders(pfrom, GetLocator(m_chainman.m_best_header), *peer)) {
4049 LogDebug(BCLog::NET, "getheaders (%d) %s to peer=%d\n",
4050 m_chainman.m_best_header->nHeight, best_block->ToString(),
4051 pfrom.GetId());
4052 }
4053 if (!state.fSyncStarted) {
4054 peer->m_inv_triggered_getheaders_before_sync = true;
4055 // Update the last block hash that triggered a new headers
4056 // sync, so that we don't turn on headers sync with more
4057 // than 1 new peer every new block.
4058 m_last_block_inv_triggering_headers_sync = *best_block;
4059 }
4060 }
4061 }
4062 4063 return;
4064 }
4065 4066 if (msg_type == NetMsgType::GETDATA) {
4067 unsigned int nCount = ReadCompactSize(vRecv);
4068 if (nCount > MAX_INV_SZ) {
4069 Misbehaving(*peer, strprintf("getdata message size = %u", nCount));
4070 return;
4071 }
4072 std::vector<CInv> vInv;
4073 vInv.resize(nCount);
4074 for (unsigned int n = 0; n < nCount; n++) {
4075 vRecv >> vInv[n];
4076 }
4077 4078 LogDebug(BCLog::NET, "received getdata (%u invsz) peer=%d\n", vInv.size(), pfrom.GetId());
4079 4080 if (vInv.size() > 0) {
4081 LogDebug(BCLog::NET, "received getdata for: %s peer=%d\n", vInv[0].ToString(), pfrom.GetId());
4082 }
4083 4084 {
4085 LOCK(peer->m_getdata_requests_mutex);
4086 peer->m_getdata_requests.insert(peer->m_getdata_requests.end(), vInv.begin(), vInv.end());
4087 ProcessGetData(pfrom, *peer, interruptMsgProc);
4088 }
4089 4090 return;
4091 }
4092 4093 if (msg_type == NetMsgType::GETBLOCKS) {
4094 CBlockLocator locator;
4095 uint256 hashStop;
4096 vRecv >> locator >> hashStop;
4097 4098 if (locator.vHave.size() > MAX_LOCATOR_SZ) {
4099 LogDebug(BCLog::NET, "getblocks locator size %lld > %d, %s\n", locator.vHave.size(), MAX_LOCATOR_SZ, pfrom.DisconnectMsg(fLogIPs));
4100 pfrom.fDisconnect = true;
4101 return;
4102 }
4103 4104 // We might have announced the currently-being-connected tip using a
4105 // compact block, which resulted in the peer sending a getblocks
4106 // request, which we would otherwise respond to without the new block.
4107 // To avoid this situation we simply verify that we are on our best
4108 // known chain now. This is super overkill, but we handle it better
4109 // for getheaders requests, and there are no known nodes which support
4110 // compact blocks but still use getblocks to request blocks.
4111 {
4112 std::shared_ptr<const CBlock> a_recent_block;
4113 {
4114 LOCK(m_most_recent_block_mutex);
4115 a_recent_block = m_most_recent_block;
4116 }
4117 BlockValidationState state;
4118 if (!m_chainman.ActiveChainstate().ActivateBestChain(state, a_recent_block)) {
4119 LogDebug(BCLog::NET, "failed to activate chain (%s)\n", state.ToString());
4120 }
4121 }
4122 4123 LOCK(cs_main);
4124 4125 // Find the last block the caller has in the main chain
4126 const CBlockIndex* pindex = m_chainman.ActiveChainstate().FindForkInGlobalIndex(locator);
4127 4128 // Send the rest of the chain
4129 if (pindex)
4130 pindex = m_chainman.ActiveChain().Next(pindex);
4131 int nLimit = 500;
4132 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());
4133 for (; pindex; pindex = m_chainman.ActiveChain().Next(pindex))
4134 {
4135 if (pindex->GetBlockHash() == hashStop)
4136 {
4137 LogDebug(BCLog::NET, " getblocks stopping at %d %s\n", pindex->nHeight, pindex->GetBlockHash().ToString());
4138 break;
4139 }
4140 // If pruning, don't inv blocks unless we have on disk and are likely to still have
4141 // for some reasonable time window (1 hour) that block relay might require.
4142 const int nPrunedBlocksLikelyToHave = MIN_BLOCKS_TO_KEEP - 3600 / m_chainparams.GetConsensus().nPowTargetSpacing;
4143 if (m_chainman.m_blockman.IsPruneMode() && (!(pindex->nStatus & BLOCK_HAVE_DATA) || pindex->nHeight <= m_chainman.ActiveChain().Tip()->nHeight - nPrunedBlocksLikelyToHave)) {
4144 LogDebug(BCLog::NET, " getblocks stopping, pruned or too old block at %d %s\n", pindex->nHeight, pindex->GetBlockHash().ToString());
4145 break;
4146 }
4147 WITH_LOCK(peer->m_block_inv_mutex, peer->m_blocks_for_inv_relay.push_back(pindex->GetBlockHash()));
4148 if (--nLimit <= 0) {
4149 // When this block is requested, we'll send an inv that'll
4150 // trigger the peer to getblocks the next batch of inventory.
4151 LogDebug(BCLog::NET, " getblocks stopping at limit %d %s\n", pindex->nHeight, pindex->GetBlockHash().ToString());
4152 WITH_LOCK(peer->m_block_inv_mutex, {peer->m_continuation_block = pindex->GetBlockHash();});
4153 break;
4154 }
4155 }
4156 return;
4157 }
4158 4159 if (msg_type == NetMsgType::GETBLOCKTXN) {
4160 BlockTransactionsRequest req;
4161 vRecv >> req;
4162 4163 std::shared_ptr<const CBlock> recent_block;
4164 {
4165 LOCK(m_most_recent_block_mutex);
4166 if (m_most_recent_block_hash == req.blockhash)
4167 recent_block = m_most_recent_block;
4168 // Unlock m_most_recent_block_mutex to avoid cs_main lock inversion
4169 }
4170 if (recent_block) {
4171 SendBlockTransactions(pfrom, *peer, *recent_block, req);
4172 return;
4173 }
4174 4175 FlatFilePos block_pos{};
4176 {
4177 LOCK(cs_main);
4178 4179 const CBlockIndex* pindex = m_chainman.m_blockman.LookupBlockIndex(req.blockhash);
4180 if (!pindex || !(pindex->nStatus & BLOCK_HAVE_DATA)) {
4181 LogDebug(BCLog::NET, "Peer %d sent us a getblocktxn for a block we don't have\n", pfrom.GetId());
4182 return;
4183 }
4184 4185 if (pindex->nHeight >= m_chainman.ActiveChain().Height() - MAX_BLOCKTXN_DEPTH) {
4186 block_pos = pindex->GetBlockPos();
4187 }
4188 }
4189 4190 if (!block_pos.IsNull()) {
4191 CBlock block;
4192 const bool ret{m_chainman.m_blockman.ReadBlock(block, block_pos, /*expected_hash=*/ req.blockhash, /*lowprio=*/true)};
4193 // If height is above MAX_BLOCKTXN_DEPTH then this block cannot get
4194 // pruned after we release cs_main above, so this read should never fail.
4195 assert(ret);
4196 4197 SendBlockTransactions(pfrom, *peer, block, req);
4198 return;
4199 }
4200 4201 // If an older block is requested (should never happen in practice,
4202 // but can happen in tests) send a block response instead of a
4203 // blocktxn response. Sending a full block response instead of a
4204 // small blocktxn response is preferable in the case where a peer
4205 // might maliciously send lots of getblocktxn requests to trigger
4206 // expensive disk reads, because it will require the peer to
4207 // actually receive all the data read from disk over the network.
4208 LogDebug(BCLog::NET, "Peer %d sent us a getblocktxn for a block > %i deep\n", pfrom.GetId(), MAX_BLOCKTXN_DEPTH);
4209 CInv inv{MSG_WITNESS_BLOCK, req.blockhash};
4210 WITH_LOCK(peer->m_getdata_requests_mutex, peer->m_getdata_requests.push_back(inv));
4211 // The message processing loop will go around again (without pausing) and we'll respond then
4212 return;
4213 }
4214 4215 if (msg_type == NetMsgType::GETHEADERS) {
4216 CBlockLocator locator;
4217 uint256 hashStop;
4218 vRecv >> locator >> hashStop;
4219 4220 if (locator.vHave.size() > MAX_LOCATOR_SZ) {
4221 LogDebug(BCLog::NET, "getheaders locator size %lld > %d, %s\n", locator.vHave.size(), MAX_LOCATOR_SZ, pfrom.DisconnectMsg(fLogIPs));
4222 pfrom.fDisconnect = true;
4223 return;
4224 }
4225 4226 if (m_chainman.m_blockman.LoadingBlocks()) {
4227 LogDebug(BCLog::NET, "Ignoring getheaders from peer=%d while importing/reindexing\n", pfrom.GetId());
4228 return;
4229 }
4230 4231 LOCK(cs_main);
4232 4233 // Note that if we were to be on a chain that forks from the checkpointed
4234 // chain, then serving those headers to a peer that has seen the
4235 // checkpointed chain would cause that peer to disconnect us. Requiring
4236 // that our chainwork exceed the minimum chain work is a protection against
4237 // being fed a bogus chain when we started up for the first time and
4238 // getting partitioned off the honest network for serving that chain to
4239 // others.
4240 if (m_chainman.ActiveTip() == nullptr ||
4241 (m_chainman.ActiveTip()->nChainWork < m_chainman.MinimumChainWork() && !pfrom.HasPermission(NetPermissionFlags::Download))) {
4242 LogDebug(BCLog::NET, "Ignoring getheaders from peer=%d because active chain has too little work; sending empty response\n", pfrom.GetId());
4243 // Just respond with an empty headers message, to tell the peer to
4244 // go away but not treat us as unresponsive.
4245 MakeAndPushMessage(pfrom, NetMsgType::HEADERS, std::vector<CBlockHeader>());
4246 return;
4247 }
4248 4249 CNodeState *nodestate = State(pfrom.GetId());
4250 const CBlockIndex* pindex = nullptr;
4251 if (locator.IsNull())
4252 {
4253 // If locator is null, return the hashStop block
4254 pindex = m_chainman.m_blockman.LookupBlockIndex(hashStop);
4255 if (!pindex) {
4256 return;
4257 }
4258 4259 if (!BlockRequestAllowed(pindex)) {
4260 LogDebug(BCLog::NET, "%s: ignoring request from peer=%i for old block header that isn't in the main chain\n", __func__, pfrom.GetId());
4261 return;
4262 }
4263 }
4264 else
4265 {
4266 // Find the last block the caller has in the main chain
4267 pindex = m_chainman.ActiveChainstate().FindForkInGlobalIndex(locator);
4268 if (pindex)
4269 pindex = m_chainman.ActiveChain().Next(pindex);
4270 }
4271 4272 // we must use CBlocks, as CBlockHeaders won't include the 0x00 nTx count at the end
4273 std::vector<CBlock> vHeaders;
4274 int nLimit = m_opts.max_headers_result;
4275 LogDebug(BCLog::NET, "getheaders %d to %s from peer=%d\n", (pindex ? pindex->nHeight : -1), hashStop.IsNull() ? "end" : hashStop.ToString(), pfrom.GetId());
4276 for (; pindex; pindex = m_chainman.ActiveChain().Next(pindex))
4277 {
4278 vHeaders.emplace_back(pindex->GetBlockHeader());
4279 if (--nLimit <= 0 || pindex->GetBlockHash() == hashStop)
4280 break;
4281 }
4282 // pindex can be nullptr either if we sent m_chainman.ActiveChain().Tip() OR
4283 // if our peer has m_chainman.ActiveChain().Tip() (and thus we are sending an empty
4284 // headers message). In both cases it's safe to update
4285 // pindexBestHeaderSent to be our tip.
4286 //
4287 // It is important that we simply reset the BestHeaderSent value here,
4288 // and not max(BestHeaderSent, newHeaderSent). We might have announced
4289 // the currently-being-connected tip using a compact block, which
4290 // resulted in the peer sending a headers request, which we respond to
4291 // without the new block. By resetting the BestHeaderSent, we ensure we
4292 // will re-announce the new block via headers (or compact blocks again)
4293 // in the SendMessages logic.
4294 nodestate->pindexBestHeaderSent = pindex ? pindex : m_chainman.ActiveChain().Tip();
4295 MakeAndPushMessage(pfrom, NetMsgType::HEADERS, TX_WITH_WITNESS(vHeaders));
4296 return;
4297 }
4298 4299 if (msg_type == NetMsgType::TX) {
4300 if (RejectIncomingTxs(pfrom)) {
4301 LogDebug(BCLog::NET, "transaction sent in violation of protocol, %s", pfrom.DisconnectMsg(fLogIPs));
4302 pfrom.fDisconnect = true;
4303 return;
4304 }
4305 4306 // Stop processing the transaction early if we are still in IBD since we don't
4307 // have enough information to validate it yet. Sending unsolicited transactions
4308 // is not considered a protocol violation, so don't punish the peer.
4309 if (m_chainman.IsInitialBlockDownload()) return;
4310 4311 CTransactionRef ptx;
4312 vRecv >> TX_WITH_WITNESS(ptx);
4313 const CTransaction& tx = *ptx;
4314 4315 const uint256& txid = ptx->GetHash();
4316 const uint256& wtxid = ptx->GetWitnessHash();
4317 4318 const uint256& hash = peer->m_wtxid_relay ? wtxid : txid;
4319 AddKnownTx(*peer, hash);
4320 4321 LOCK2(cs_main, m_tx_download_mutex);
4322 4323 const auto& [should_validate, package_to_validate] = m_txdownloadman.ReceivedTx(pfrom.GetId(), ptx);
4324 if (!should_validate) {
4325 if (pfrom.HasPermission(NetPermissionFlags::ForceRelay)) {
4326 // Always relay transactions received from peers with forcerelay
4327 // permission, even if they were already in the mempool, allowing
4328 // the node to function as a gateway for nodes hidden behind it.
4329 if (!m_mempool.exists(GenTxid::Txid(tx.GetHash()))) {
4330 LogPrintf("Not relaying non-mempool transaction %s (wtxid=%s) from forcerelay peer=%d\n",
4331 tx.GetHash().ToString(), tx.GetWitnessHash().ToString(), pfrom.GetId());
4332 } else {
4333 LogPrintf("Force relaying tx %s (wtxid=%s) from peer=%d\n",
4334 tx.GetHash().ToString(), tx.GetWitnessHash().ToString(), pfrom.GetId());
4335 RelayTransaction(tx.GetHash(), tx.GetWitnessHash());
4336 }
4337 }
4338 4339 if (package_to_validate) {
4340 const auto package_result{ProcessNewPackage(m_chainman.ActiveChainstate(), m_mempool, package_to_validate->m_txns, /*test_accept=*/false, /*client_maxfeerate=*/std::nullopt)};
4341 LogDebug(BCLog::TXPACKAGES, "package evaluation for %s: %s\n", package_to_validate->ToString(),
4342 package_result.m_state.IsValid() ? "package accepted" : "package rejected");
4343 ProcessPackageResult(package_to_validate.value(), package_result);
4344 }
4345 return;
4346 }
4347 4348 // ReceivedTx should not be telling us to validate the tx and a package.
4349 Assume(!package_to_validate.has_value());
4350 4351 const MempoolAcceptResult result = m_chainman.ProcessTransaction(ptx);
4352 const TxValidationState& state = result.m_state;
4353 4354 if (result.m_result_type == MempoolAcceptResult::ResultType::VALID) {
4355 ProcessValidTx(pfrom.GetId(), ptx, result.m_replaced_transactions);
4356 pfrom.m_last_tx_time = GetTime<std::chrono::seconds>();
4357 }
4358 if (state.IsInvalid()) {
4359 if (auto package_to_validate{ProcessInvalidTx(pfrom.GetId(), ptx, state, /*first_time_failure=*/true)}) {
4360 const auto package_result{ProcessNewPackage(m_chainman.ActiveChainstate(), m_mempool, package_to_validate->m_txns, /*test_accept=*/false, /*client_maxfeerate=*/std::nullopt)};
4361 LogDebug(BCLog::TXPACKAGES, "package evaluation for %s: %s\n", package_to_validate->ToString(),
4362 package_result.m_state.IsValid() ? "package accepted" : "package rejected");
4363 ProcessPackageResult(package_to_validate.value(), package_result);
4364 }
4365 }
4366 4367 return;
4368 }
4369 4370 if (msg_type == NetMsgType::CMPCTBLOCK)
4371 {
4372 // Ignore cmpctblock received while importing
4373 if (m_chainman.m_blockman.LoadingBlocks()) {
4374 LogDebug(BCLog::NET, "Unexpected cmpctblock message received from peer %d\n", pfrom.GetId());
4375 return;
4376 }
4377 4378 CBlockHeaderAndShortTxIDs cmpctblock;
4379 vRecv >> cmpctblock;
4380 4381 bool received_new_header = false;
4382 const auto blockhash = cmpctblock.header.GetHash();
4383 4384 {
4385 LOCK(cs_main);
4386 4387 const CBlockIndex* prev_block = m_chainman.m_blockman.LookupBlockIndex(cmpctblock.header.hashPrevBlock);
4388 if (!prev_block) {
4389 // Doesn't connect (or is genesis), instead of DoSing in AcceptBlockHeader, request deeper headers
4390 if (!m_chainman.IsInitialBlockDownload()) {
4391 MaybeSendGetHeaders(pfrom, GetLocator(m_chainman.m_best_header), *peer);
4392 }
4393 return;
4394 } else if (prev_block->nChainWork + CalculateClaimedHeadersWork({{cmpctblock.header}}) < GetAntiDoSWorkThreshold()) {
4395 // If we get a low-work header in a compact block, we can ignore it.
4396 LogDebug(BCLog::NET, "Ignoring low-work compact block from peer %d\n", pfrom.GetId());
4397 return;
4398 }
4399 4400 if (!m_chainman.m_blockman.LookupBlockIndex(blockhash)) {
4401 received_new_header = true;
4402 }
4403 }
4404 4405 const CBlockIndex *pindex = nullptr;
4406 BlockValidationState state;
4407 if (!m_chainman.ProcessNewBlockHeaders({{cmpctblock.header}}, /*min_pow_checked=*/true, state, &pindex)) {
4408 if (state.IsInvalid()) {
4409 MaybePunishNodeForBlock(pfrom.GetId(), state, /*via_compact_block=*/true, "invalid header via cmpctblock");
4410 return;
4411 }
4412 }
4413 4414 if (received_new_header) {
4415 LogInfo("Saw new cmpctblock header hash=%s peer=%d\n",
4416 blockhash.ToString(), pfrom.GetId());
4417 }
4418 4419 bool fProcessBLOCKTXN = false;
4420 4421 // If we end up treating this as a plain headers message, call that as well
4422 // without cs_main.
4423 bool fRevertToHeaderProcessing = false;
4424 4425 // Keep a CBlock for "optimistic" compactblock reconstructions (see
4426 // below)
4427 std::shared_ptr<CBlock> pblock = std::make_shared<CBlock>();
4428 bool fBlockReconstructed = false;
4429 4430 {
4431 LOCK(cs_main);
4432 // If AcceptBlockHeader returned true, it set pindex
4433 assert(pindex);
4434 UpdateBlockAvailability(pfrom.GetId(), pindex->GetBlockHash());
4435 4436 CNodeState *nodestate = State(pfrom.GetId());
4437 4438 // If this was a new header with more work than our tip, update the
4439 // peer's last block announcement time
4440 if (received_new_header && pindex->nChainWork > m_chainman.ActiveChain().Tip()->nChainWork) {
4441 nodestate->m_last_block_announcement = GetTime();
4442 }
4443 4444 if (pindex->nStatus & BLOCK_HAVE_DATA) // Nothing to do here
4445 return;
4446 4447 auto range_flight = mapBlocksInFlight.equal_range(pindex->GetBlockHash());
4448 size_t already_in_flight = std::distance(range_flight.first, range_flight.second);
4449 bool requested_block_from_this_peer{false};
4450 4451 // Multimap ensures ordering of outstanding requests. It's either empty or first in line.
4452 bool first_in_flight = already_in_flight == 0 || (range_flight.first->second.first == pfrom.GetId());
4453 4454 while (range_flight.first != range_flight.second) {
4455 if (range_flight.first->second.first == pfrom.GetId()) {
4456 requested_block_from_this_peer = true;
4457 break;
4458 }
4459 range_flight.first++;
4460 }
4461 4462 if (pindex->nChainWork <= m_chainman.ActiveChain().Tip()->nChainWork || // We know something better
4463 pindex->nTx != 0) { // We had this block at some point, but pruned it
4464 if (requested_block_from_this_peer) {
4465 // We requested this block for some reason, but our mempool will probably be useless
4466 // so we just grab the block via normal getdata
4467 std::vector<CInv> vInv(1);
4468 vInv[0] = CInv(MSG_BLOCK | GetFetchFlags(*peer), blockhash);
4469 MakeAndPushMessage(pfrom, NetMsgType::GETDATA, vInv);
4470 }
4471 return;
4472 }
4473 4474 // If we're not close to tip yet, give up and let parallel block fetch work its magic
4475 if (!already_in_flight && !CanDirectFetch()) {
4476 return;
4477 }
4478 4479 // We want to be a bit conservative just to be extra careful about DoS
4480 // possibilities in compact block processing...
4481 if (pindex->nHeight <= m_chainman.ActiveChain().Height() + 2) {
4482 if ((already_in_flight < MAX_CMPCTBLOCKS_INFLIGHT_PER_BLOCK && nodestate->vBlocksInFlight.size() < MAX_BLOCKS_IN_TRANSIT_PER_PEER) ||
4483 requested_block_from_this_peer) {
4484 std::list<QueuedBlock>::iterator* queuedBlockIt = nullptr;
4485 if (!BlockRequested(pfrom.GetId(), *pindex, &queuedBlockIt)) {
4486 if (!(*queuedBlockIt)->partialBlock)
4487 (*queuedBlockIt)->partialBlock.reset(new PartiallyDownloadedBlock(&m_mempool));
4488 else {
4489 // The block was already in flight using compact blocks from the same peer
4490 LogDebug(BCLog::NET, "Peer sent us compact block we were already syncing!\n");
4491 return;
4492 }
4493 }
4494 4495 PartiallyDownloadedBlock& partialBlock = *(*queuedBlockIt)->partialBlock;
4496 ReadStatus status = partialBlock.InitData(cmpctblock, vExtraTxnForCompact);
4497 if (status == READ_STATUS_INVALID) {
4498 RemoveBlockRequest(pindex->GetBlockHash(), pfrom.GetId()); // Reset in-flight state in case Misbehaving does not result in a disconnect
4499 Misbehaving(*peer, "invalid compact block");
4500 return;
4501 } else if (status == READ_STATUS_FAILED) {
4502 if (first_in_flight) {
4503 // Duplicate txindexes, the block is now in-flight, so just request it
4504 std::vector<CInv> vInv(1);
4505 vInv[0] = CInv(MSG_BLOCK | GetFetchFlags(*peer), blockhash);
4506 MakeAndPushMessage(pfrom, NetMsgType::GETDATA, vInv);
4507 } else {
4508 // Give up for this peer and wait for other peer(s)
4509 RemoveBlockRequest(pindex->GetBlockHash(), pfrom.GetId());
4510 }
4511 return;
4512 }
4513 4514 BlockTransactionsRequest req;
4515 for (size_t i = 0; i < cmpctblock.BlockTxCount(); i++) {
4516 if (!partialBlock.IsTxAvailable(i))
4517 req.indexes.push_back(i);
4518 }
4519 if (req.indexes.empty()) {
4520 fProcessBLOCKTXN = true;
4521 } else if (first_in_flight) {
4522 // We will try to round-trip any compact blocks we get on failure,
4523 // as long as it's first...
4524 req.blockhash = pindex->GetBlockHash();
4525 MakeAndPushMessage(pfrom, NetMsgType::GETBLOCKTXN, req);
4526 } else if (pfrom.m_bip152_highbandwidth_to &&
4527 (!pfrom.IsInboundConn() ||
4528 IsBlockRequestedFromOutbound(blockhash) ||
4529 already_in_flight < MAX_CMPCTBLOCKS_INFLIGHT_PER_BLOCK - 1)) {
4530 // ... or it's a hb relay peer and:
4531 // - peer is outbound, or
4532 // - we already have an outbound attempt in flight(so we'll take what we can get), or
4533 // - it's not the final parallel download slot (which we may reserve for first outbound)
4534 req.blockhash = pindex->GetBlockHash();
4535 MakeAndPushMessage(pfrom, NetMsgType::GETBLOCKTXN, req);
4536 } else {
4537 // Give up for this peer and wait for other peer(s)
4538 RemoveBlockRequest(pindex->GetBlockHash(), pfrom.GetId());
4539 }
4540 } else {
4541 // This block is either already in flight from a different
4542 // peer, or this peer has too many blocks outstanding to
4543 // download from.
4544 // Optimistically try to reconstruct anyway since we might be
4545 // able to without any round trips.
4546 PartiallyDownloadedBlock tempBlock(&m_mempool);
4547 ReadStatus status = tempBlock.InitData(cmpctblock, vExtraTxnForCompact);
4548 if (status != READ_STATUS_OK) {
4549 // TODO: don't ignore failures
4550 return;
4551 }
4552 std::vector<CTransactionRef> dummy;
4553 const CBlockIndex* prev_block{Assume(m_chainman.m_blockman.LookupBlockIndex(cmpctblock.header.hashPrevBlock))};
4554 status = tempBlock.FillBlock(*pblock, dummy,
4555 /*segwit_active=*/DeploymentActiveAfter(prev_block, m_chainman, Consensus::DEPLOYMENT_SEGWIT));
4556 if (status == READ_STATUS_OK) {
4557 fBlockReconstructed = true;
4558 }
4559 }
4560 } else {
4561 if (requested_block_from_this_peer) {
4562 // We requested this block, but its far into the future, so our
4563 // mempool will probably be useless - request the block normally
4564 std::vector<CInv> vInv(1);
4565 vInv[0] = CInv(MSG_BLOCK | GetFetchFlags(*peer), blockhash);
4566 MakeAndPushMessage(pfrom, NetMsgType::GETDATA, vInv);
4567 return;
4568 } else {
4569 // If this was an announce-cmpctblock, we want the same treatment as a header message
4570 fRevertToHeaderProcessing = true;
4571 }
4572 }
4573 } // cs_main
4574 4575 if (fProcessBLOCKTXN) {
4576 BlockTransactions txn;
4577 txn.blockhash = blockhash;
4578 return ProcessCompactBlockTxns(pfrom, *peer, txn);
4579 }
4580 4581 if (fRevertToHeaderProcessing) {
4582 // Headers received from HB compact block peers are permitted to be
4583 // relayed before full validation (see BIP 152), so we don't want to disconnect
4584 // the peer if the header turns out to be for an invalid block.
4585 // Note that if a peer tries to build on an invalid chain, that
4586 // will be detected and the peer will be disconnected/discouraged.
4587 return ProcessHeadersMessage(pfrom, *peer, {cmpctblock.header}, /*via_compact_block=*/true);
4588 }
4589 4590 if (fBlockReconstructed) {
4591 // If we got here, we were able to optimistically reconstruct a
4592 // block that is in flight from some other peer.
4593 {
4594 LOCK(cs_main);
4595 mapBlockSource.emplace(pblock->GetHash(), std::make_pair(pfrom.GetId(), false));
4596 }
4597 // Setting force_processing to true means that we bypass some of
4598 // our anti-DoS protections in AcceptBlock, which filters
4599 // unrequested blocks that might be trying to waste our resources
4600 // (eg disk space). Because we only try to reconstruct blocks when
4601 // we're close to caught up (via the CanDirectFetch() requirement
4602 // above, combined with the behavior of not requesting blocks until
4603 // we have a chain with at least the minimum chain work), and we ignore
4604 // compact blocks with less work than our tip, it is safe to treat
4605 // reconstructed compact blocks as having been requested.
4606 ProcessBlock(pfrom, pblock, /*force_processing=*/true, /*min_pow_checked=*/true);
4607 LOCK(cs_main); // hold cs_main for CBlockIndex::IsValid()
4608 if (pindex->IsValid(BLOCK_VALID_TRANSACTIONS)) {
4609 // Clear download state for this block, which is in
4610 // process from some other peer. We do this after calling
4611 // ProcessNewBlock so that a malleated cmpctblock announcement
4612 // can't be used to interfere with block relay.
4613 RemoveBlockRequest(pblock->GetHash(), std::nullopt);
4614 }
4615 }
4616 return;
4617 }
4618 4619 if (msg_type == NetMsgType::BLOCKTXN)
4620 {
4621 // Ignore blocktxn received while importing
4622 if (m_chainman.m_blockman.LoadingBlocks()) {
4623 LogDebug(BCLog::NET, "Unexpected blocktxn message received from peer %d\n", pfrom.GetId());
4624 return;
4625 }
4626 4627 BlockTransactions resp;
4628 vRecv >> resp;
4629 4630 return ProcessCompactBlockTxns(pfrom, *peer, resp);
4631 }
4632 4633 if (msg_type == NetMsgType::HEADERS)
4634 {
4635 // Ignore headers received while importing
4636 if (m_chainman.m_blockman.LoadingBlocks()) {
4637 LogDebug(BCLog::NET, "Unexpected headers message received from peer %d\n", pfrom.GetId());
4638 return;
4639 }
4640 4641 std::vector<CBlockHeader> headers;
4642 4643 // Bypass the normal CBlock deserialization, as we don't want to risk deserializing 2000 full blocks.
4644 unsigned int nCount = ReadCompactSize(vRecv);
4645 if (nCount > m_opts.max_headers_result) {
4646 Misbehaving(*peer, strprintf("headers message size = %u", nCount));
4647 return;
4648 }
4649 headers.resize(nCount);
4650 for (unsigned int n = 0; n < nCount; n++) {
4651 vRecv >> headers[n];
4652 ReadCompactSize(vRecv); // ignore tx count; assume it is 0.
4653 }
4654 4655 ProcessHeadersMessage(pfrom, *peer, std::move(headers), /*via_compact_block=*/false);
4656 4657 // Check if the headers presync progress needs to be reported to validation.
4658 // This needs to be done without holding the m_headers_presync_mutex lock.
4659 if (m_headers_presync_should_signal.exchange(false)) {
4660 HeadersPresyncStats stats;
4661 {
4662 LOCK(m_headers_presync_mutex);
4663 auto it = m_headers_presync_stats.find(m_headers_presync_bestpeer);
4664 if (it != m_headers_presync_stats.end()) stats = it->second;
4665 }
4666 if (stats.second) {
4667 m_chainman.ReportHeadersPresync(stats.first, stats.second->first, stats.second->second);
4668 }
4669 }
4670 4671 return;
4672 }
4673 4674 if (msg_type == NetMsgType::BLOCK)
4675 {
4676 // Ignore block received while importing
4677 if (m_chainman.m_blockman.LoadingBlocks()) {
4678 LogDebug(BCLog::NET, "Unexpected block message received from peer %d\n", pfrom.GetId());
4679 return;
4680 }
4681 4682 std::shared_ptr<CBlock> pblock = std::make_shared<CBlock>();
4683 vRecv >> TX_WITH_WITNESS(*pblock);
4684 4685 LogDebug(BCLog::NET, "received block %s peer=%d\n", pblock->GetHash().ToString(), pfrom.GetId());
4686 4687 const CBlockIndex* prev_block{WITH_LOCK(m_chainman.GetMutex(), return m_chainman.m_blockman.LookupBlockIndex(pblock->hashPrevBlock))};
4688 4689 // Check for possible mutation if it connects to something we know so we can check for DEPLOYMENT_SEGWIT being active.
4690 // The fork chain always expects the witness commitment (its blocks
4691 // carry witness data from the very first fork block, long before the
4692 // inherited mainnet SEGWIT height would be "active"), so the receipt
4693 // check must mirror ContextualCheckBlock's segwit_expected.
4694 const bool check_witness_root = DeploymentActiveAfter(prev_block, m_chainman, Consensus::DEPLOYMENT_SEGWIT)
4695 || IsForkActive(prev_block, m_chainman.GetParams().GetConsensus());
4696 if (prev_block && IsBlockMutated(/*block=*/*pblock, check_witness_root)) {
4697 LogDebug(BCLog::NET, "Received mutated block from peer=%d\n", peer->m_id);
4698 Misbehaving(*peer, "mutated block");
4699 WITH_LOCK(cs_main, RemoveBlockRequest(pblock->GetHash(), peer->m_id));
4700 return;
4701 }
4702 4703 bool forceProcessing = false;
4704 const uint256 hash(pblock->GetHash());
4705 bool min_pow_checked = false;
4706 {
4707 LOCK(cs_main);
4708 // Always process the block if we requested it, since we may
4709 // need it even when it's not a candidate for a new best tip.
4710 forceProcessing = IsBlockRequested(hash);
4711 RemoveBlockRequest(hash, pfrom.GetId());
4712 // mapBlockSource is only used for punishing peers and setting
4713 // which peers send us compact blocks, so the race between here and
4714 // cs_main in ProcessNewBlock is fine.
4715 mapBlockSource.emplace(hash, std::make_pair(pfrom.GetId(), true));
4716 4717 // Check claimed work on this block against our anti-dos thresholds.
4718 if (prev_block && prev_block->nChainWork + CalculateClaimedHeadersWork({{pblock->GetBlockHeader()}}) >= GetAntiDoSWorkThreshold()) {
4719 min_pow_checked = true;
4720 }
4721 }
4722 ProcessBlock(pfrom, pblock, forceProcessing, min_pow_checked);
4723 return;
4724 }
4725 4726 if (msg_type == NetMsgType::GETADDR) {
4727 // This asymmetric behavior for inbound and outbound connections was introduced
4728 // to prevent a fingerprinting attack: an attacker can send specific fake addresses
4729 // to users' AddrMan and later request them by sending getaddr messages.
4730 // Making nodes which are behind NAT and can only make outgoing connections ignore
4731 // the getaddr message mitigates the attack.
4732 if (!pfrom.IsInboundConn()) {
4733 LogDebug(BCLog::NET, "Ignoring \"getaddr\" from %s connection. peer=%d\n", pfrom.ConnectionTypeAsString(), pfrom.GetId());
4734 return;
4735 }
4736 4737 // Since this must be an inbound connection, SetupAddressRelay will
4738 // never fail.
4739 Assume(SetupAddressRelay(pfrom, *peer));
4740 4741 // Only send one GetAddr response per connection to reduce resource waste
4742 // and discourage addr stamping of INV announcements.
4743 if (peer->m_getaddr_recvd) {
4744 LogDebug(BCLog::NET, "Ignoring repeated \"getaddr\". peer=%d\n", pfrom.GetId());
4745 return;
4746 }
4747 peer->m_getaddr_recvd = true;
4748 4749 peer->m_addrs_to_send.clear();
4750 std::vector<CAddress> vAddr;
4751 if (pfrom.HasPermission(NetPermissionFlags::Addr)) {
4752 vAddr = m_connman.GetAddresses(MAX_ADDR_TO_SEND, MAX_PCT_ADDR_TO_SEND, /*network=*/std::nullopt);
4753 } else {
4754 vAddr = m_connman.GetAddresses(pfrom, MAX_ADDR_TO_SEND, MAX_PCT_ADDR_TO_SEND);
4755 }
4756 for (const CAddress &addr : vAddr) {
4757 PushAddress(*peer, addr);
4758 }
4759 return;
4760 }
4761 4762 if (msg_type == NetMsgType::MEMPOOL) {
4763 // Only process received mempool messages if we advertise NODE_BLOOM
4764 // or if the peer has mempool permissions.
4765 if (!(peer->m_our_services & NODE_BLOOM) && !pfrom.HasPermission(NetPermissionFlags::Mempool))
4766 {
4767 if (!pfrom.HasPermission(NetPermissionFlags::NoBan))
4768 {
4769 LogDebug(BCLog::NET, "mempool request with bloom filters disabled, %s\n", pfrom.DisconnectMsg(fLogIPs));
4770 pfrom.fDisconnect = true;
4771 }
4772 return;
4773 }
4774 4775 if (m_connman.OutboundTargetReached(false) && !pfrom.HasPermission(NetPermissionFlags::Mempool))
4776 {
4777 if (!pfrom.HasPermission(NetPermissionFlags::NoBan))
4778 {
4779 LogDebug(BCLog::NET, "mempool request with bandwidth limit reached, %s\n", pfrom.DisconnectMsg(fLogIPs));
4780 pfrom.fDisconnect = true;
4781 }
4782 return;
4783 }
4784 4785 if (auto tx_relay = peer->GetTxRelay(); tx_relay != nullptr) {
4786 LOCK(tx_relay->m_tx_inventory_mutex);
4787 tx_relay->m_send_mempool = true;
4788 }
4789 return;
4790 }
4791 4792 if (msg_type == NetMsgType::PING) {
4793 if (pfrom.GetCommonVersion() > BIP0031_VERSION) {
4794 uint64_t nonce = 0;
4795 vRecv >> nonce;
4796 // Echo the message back with the nonce. This allows for two useful features:
4797 //
4798 // 1) A remote node can quickly check if the connection is operational
4799 // 2) Remote nodes can measure the latency of the network thread. If this node
4800 // is overloaded it won't respond to pings quickly and the remote node can
4801 // avoid sending us more work, like chain download requests.
4802 //
4803 // The nonce stops the remote getting confused between different pings: without
4804 // it, if the remote node sends a ping once per second and this node takes 5
4805 // seconds to respond to each, the 5th ping the remote sends would appear to
4806 // return very quickly.
4807 MakeAndPushMessage(pfrom, NetMsgType::PONG, nonce);
4808 }
4809 return;
4810 }
4811 4812 if (msg_type == NetMsgType::PONG) {
4813 const auto ping_end = time_received;
4814 uint64_t nonce = 0;
4815 size_t nAvail = vRecv.in_avail();
4816 bool bPingFinished = false;
4817 std::string sProblem;
4818 4819 if (nAvail >= sizeof(nonce)) {
4820 vRecv >> nonce;
4821 4822 // Only process pong message if there is an outstanding ping (old ping without nonce should never pong)
4823 if (peer->m_ping_nonce_sent != 0) {
4824 if (nonce == peer->m_ping_nonce_sent) {
4825 // Matching pong received, this ping is no longer outstanding
4826 bPingFinished = true;
4827 const auto ping_time = ping_end - peer->m_ping_start.load();
4828 if (ping_time.count() >= 0) {
4829 // Let connman know about this successful ping-pong
4830 pfrom.PongReceived(ping_time);
4831 } else {
4832 // This should never happen
4833 sProblem = "Timing mishap";
4834 }
4835 } else {
4836 // Nonce mismatches are normal when pings are overlapping
4837 sProblem = "Nonce mismatch";
4838 if (nonce == 0) {
4839 // This is most likely a bug in another implementation somewhere; cancel this ping
4840 bPingFinished = true;
4841 sProblem = "Nonce zero";
4842 }
4843 }
4844 } else {
4845 sProblem = "Unsolicited pong without ping";
4846 }
4847 } else {
4848 // This is most likely a bug in another implementation somewhere; cancel this ping
4849 bPingFinished = true;
4850 sProblem = "Short payload";
4851 }
4852 4853 if (!(sProblem.empty())) {
4854 LogDebug(BCLog::NET, "pong peer=%d: %s, %x expected, %x received, %u bytes\n",
4855 pfrom.GetId(),
4856 sProblem,
4857 peer->m_ping_nonce_sent,
4858 nonce,
4859 nAvail);
4860 }
4861 if (bPingFinished) {
4862 peer->m_ping_nonce_sent = 0;
4863 }
4864 return;
4865 }
4866 4867 if (msg_type == NetMsgType::FILTERLOAD) {
4868 if (!(peer->m_our_services & NODE_BLOOM)) {
4869 LogDebug(BCLog::NET, "filterload received despite not offering bloom services, %s\n", pfrom.DisconnectMsg(fLogIPs));
4870 pfrom.fDisconnect = true;
4871 return;
4872 }
4873 CBloomFilter filter;
4874 vRecv >> filter;
4875 4876 if (!filter.IsWithinSizeConstraints())
4877 {
4878 // There is no excuse for sending a too-large filter
4879 Misbehaving(*peer, "too-large bloom filter");
4880 } else if (auto tx_relay = peer->GetTxRelay(); tx_relay != nullptr) {
4881 {
4882 LOCK(tx_relay->m_bloom_filter_mutex);
4883 tx_relay->m_bloom_filter.reset(new CBloomFilter(filter));
4884 tx_relay->m_relay_txs = true;
4885 }
4886 pfrom.m_bloom_filter_loaded = true;
4887 pfrom.m_relays_txs = true;
4888 }
4889 return;
4890 }
4891 4892 if (msg_type == NetMsgType::FILTERADD) {
4893 if (!(peer->m_our_services & NODE_BLOOM)) {
4894 LogDebug(BCLog::NET, "filteradd received despite not offering bloom services, %s\n", pfrom.DisconnectMsg(fLogIPs));
4895 pfrom.fDisconnect = true;
4896 return;
4897 }
4898 std::vector<unsigned char> vData;
4899 vRecv >> vData;
4900 4901 // Nodes must NEVER send a data item > MAX_SCRIPT_ELEMENT_SIZE bytes (the max size for a script data object,
4902 // and thus, the maximum size any matched object can have) in a filteradd message
4903 bool bad = false;
4904 if (vData.size() > MAX_SCRIPT_ELEMENT_SIZE) {
4905 bad = true;
4906 } else if (auto tx_relay = peer->GetTxRelay(); tx_relay != nullptr) {
4907 LOCK(tx_relay->m_bloom_filter_mutex);
4908 if (tx_relay->m_bloom_filter) {
4909 tx_relay->m_bloom_filter->insert(vData);
4910 } else {
4911 bad = true;
4912 }
4913 }
4914 if (bad) {
4915 Misbehaving(*peer, "bad filteradd message");
4916 }
4917 return;
4918 }
4919 4920 if (msg_type == NetMsgType::FILTERCLEAR) {
4921 if (!(peer->m_our_services & NODE_BLOOM)) {
4922 LogDebug(BCLog::NET, "filterclear received despite not offering bloom services, %s\n", pfrom.DisconnectMsg(fLogIPs));
4923 pfrom.fDisconnect = true;
4924 return;
4925 }
4926 auto tx_relay = peer->GetTxRelay();
4927 if (!tx_relay) return;
4928 4929 {
4930 LOCK(tx_relay->m_bloom_filter_mutex);
4931 tx_relay->m_bloom_filter = nullptr;
4932 tx_relay->m_relay_txs = true;
4933 }
4934 pfrom.m_bloom_filter_loaded = false;
4935 pfrom.m_relays_txs = true;
4936 return;
4937 }
4938 4939 if (msg_type == NetMsgType::FEEFILTER) {
4940 CAmount newFeeFilter = 0;
4941 vRecv >> newFeeFilter;
4942 if (MoneyRange(newFeeFilter)) {
4943 if (auto tx_relay = peer->GetTxRelay(); tx_relay != nullptr) {
4944 tx_relay->m_fee_filter_received = newFeeFilter;
4945 }
4946 LogDebug(BCLog::NET, "received: feefilter of %s from peer=%d\n", CFeeRate(newFeeFilter).ToString(), pfrom.GetId());
4947 }
4948 return;
4949 }
4950 4951 if (msg_type == NetMsgType::GETCFILTERS) {
4952 ProcessGetCFilters(pfrom, *peer, vRecv);
4953 return;
4954 }
4955 4956 if (msg_type == NetMsgType::GETCFHEADERS) {
4957 ProcessGetCFHeaders(pfrom, *peer, vRecv);
4958 return;
4959 }
4960 4961 if (msg_type == NetMsgType::GETCFCHECKPT) {
4962 ProcessGetCFCheckPt(pfrom, *peer, vRecv);
4963 return;
4964 }
4965 4966 if (msg_type == NetMsgType::NOTFOUND) {
4967 unsigned int nCount = ReadCompactSize(vRecv);
4968 static constexpr unsigned int MAX_NOTFOUND_SZ = node::MAX_PEER_TX_ANNOUNCEMENTS + MAX_BLOCKS_IN_TRANSIT_PER_PEER;
4969 if (nCount > MAX_NOTFOUND_SZ) {
4970 Misbehaving(*peer, strprintf("notfound message size = %u", nCount));
4971 return;
4972 }
4973 std::vector<CInv> vInv;
4974 vInv.resize(nCount);
4975 for (unsigned int n = 0; n < nCount; n++) {
4976 vRecv >> vInv[n];
4977 }
4978 std::vector<uint256> tx_invs;
4979 for (CInv &inv : vInv) {
4980 if (inv.IsGenTxMsg()) {
4981 tx_invs.emplace_back(inv.hash);
4982 }
4983 }
4984 LOCK(m_tx_download_mutex);
4985 m_txdownloadman.ReceivedNotFound(pfrom.GetId(), tx_invs);
4986 return;
4987 }
4988 4989 // Ignore unknown commands for extensibility
4990 LogDebug(BCLog::NET, "Unknown command \"%s\" from peer=%d\n", SanitizeString(msg_type), pfrom.GetId());
4991 return;
4992 }
4993 4994 bool PeerManagerImpl::MaybeDiscourageAndDisconnect(CNode& pnode, Peer& peer)
4995 {
4996 {
4997 LOCK(peer.m_misbehavior_mutex);
4998 4999 // There's nothing to do if the m_should_discourage flag isn't set
5000 if (!peer.m_should_discourage) return false;
5001 5002 peer.m_should_discourage = false;
5003 } // peer.m_misbehavior_mutex
5004 5005 if (pnode.HasPermission(NetPermissionFlags::NoBan)) {
5006 // We never disconnect or discourage peers for bad behavior if they have NetPermissionFlags::NoBan permission
5007 LogWarning("Not punishing noban peer %d!", peer.m_id);
5008 return false;
5009 }
5010 5011 if (pnode.IsManualConn()) {
5012 // We never disconnect or discourage manual peers for bad behavior
5013 LogWarning("Not punishing manually connected peer %d!", peer.m_id);
5014 return false;
5015 }
5016 5017 if (pnode.addr.IsLocal()) {
5018 // We disconnect local peers for bad behavior but don't discourage (since that would discourage
5019 // all peers on the same local address)
5020 LogDebug(BCLog::NET, "Warning: disconnecting but not discouraging %s peer %d!\n",
5021 pnode.m_inbound_onion ? "inbound onion" : "local", peer.m_id);
5022 pnode.fDisconnect = true;
5023 return true;
5024 }
5025 5026 // Normal case: Disconnect the peer and discourage all nodes sharing the address
5027 LogDebug(BCLog::NET, "Disconnecting and discouraging peer %d!\n", peer.m_id);
5028 if (m_banman) m_banman->Discourage(pnode.addr);
5029 m_connman.DisconnectNode(pnode.addr);
5030 return true;
5031 }
5032 5033 bool PeerManagerImpl::ProcessMessages(CNode* pfrom, std::atomic<bool>& interruptMsgProc)
5034 {
5035 AssertLockNotHeld(m_tx_download_mutex);
5036 AssertLockHeld(g_msgproc_mutex);
5037 5038 PeerRef peer = GetPeerRef(pfrom->GetId());
5039 if (peer == nullptr) return false;
5040 5041 // For outbound connections, ensure that the initial VERSION message
5042 // has been sent first before processing any incoming messages
5043 if (!pfrom->IsInboundConn() && !peer->m_outbound_version_message_sent) return false;
5044 5045 {
5046 LOCK(peer->m_getdata_requests_mutex);
5047 if (!peer->m_getdata_requests.empty()) {
5048 ProcessGetData(*pfrom, *peer, interruptMsgProc);
5049 }
5050 }
5051 5052 const bool processed_orphan = ProcessOrphanTx(*peer);
5053 5054 if (pfrom->fDisconnect)
5055 return false;
5056 5057 if (processed_orphan) return true;
5058 5059 // this maintains the order of responses
5060 // and prevents m_getdata_requests to grow unbounded
5061 {
5062 LOCK(peer->m_getdata_requests_mutex);
5063 if (!peer->m_getdata_requests.empty()) return true;
5064 }
5065 5066 // Don't bother if send buffer is too full to respond anyway
5067 if (pfrom->fPauseSend) return false;
5068 5069 auto poll_result{pfrom->PollMessage()};
5070 if (!poll_result) {
5071 // No message to process
5072 return false;
5073 }
5074 5075 CNetMessage& msg{poll_result->first};
5076 bool fMoreWork = poll_result->second;
5077 5078 TRACEPOINT(net, inbound_message,
5079 pfrom->GetId(),
5080 pfrom->m_addr_name.c_str(),
5081 pfrom->ConnectionTypeAsString().c_str(),
5082 msg.m_type.c_str(),
5083 msg.m_recv.size(),
5084 msg.m_recv.data()
5085 );
5086 5087 if (m_opts.capture_messages) {
5088 CaptureMessage(pfrom->addr, msg.m_type, MakeUCharSpan(msg.m_recv), /*is_incoming=*/true);
5089 }
5090 5091 try {
5092 ProcessMessage(*pfrom, msg.m_type, msg.m_recv, msg.m_time, interruptMsgProc);
5093 if (interruptMsgProc) return false;
5094 {
5095 LOCK(peer->m_getdata_requests_mutex);
5096 if (!peer->m_getdata_requests.empty()) fMoreWork = true;
5097 }
5098 // Does this peer has an orphan ready to reconsider?
5099 // (Note: we may have provided a parent for an orphan provided
5100 // by another peer that was already processed; in that case,
5101 // the extra work may not be noticed, possibly resulting in an
5102 // unnecessary 100ms delay)
5103 LOCK(m_tx_download_mutex);
5104 if (m_txdownloadman.HaveMoreWork(peer->m_id)) fMoreWork = true;
5105 peer->m_deserialization_failures = 0;
5106 } catch (const std::exception& e) {
5107 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());
5108 peer->m_deserialization_failures++;
5109 if (peer->m_deserialization_failures >= 5) {
5110 LogWarning("disconnecting peer=%d after %u deserialization failures\n", pfrom->GetId(), peer->m_deserialization_failures);
5111 pfrom->fDisconnect = true;
5112 }
5113 } catch (...) {
5114 LogDebug(BCLog::NET, "%s(%s, %u bytes): Unknown exception caught\n", __func__, SanitizeString(msg.m_type), msg.m_message_size);
5115 peer->m_deserialization_failures++;
5116 if (peer->m_deserialization_failures >= 5) {
5117 LogWarning("disconnecting peer=%d after %u deserialization failures\n", pfrom->GetId(), peer->m_deserialization_failures);
5118 pfrom->fDisconnect = true;
5119 }
5120 }
5121 5122 return fMoreWork;
5123 }
5124 5125 void PeerManagerImpl::ConsiderEviction(CNode& pto, Peer& peer, std::chrono::seconds time_in_seconds)
5126 {
5127 AssertLockHeld(cs_main);
5128 5129 CNodeState &state = *State(pto.GetId());
5130 5131 if (!state.m_chain_sync.m_protect && pto.IsOutboundOrBlockRelayConn() && state.fSyncStarted) {
5132 // This is an outbound peer subject to disconnection if they don't
5133 // announce a block with as much work as the current tip within
5134 // CHAIN_SYNC_TIMEOUT + HEADERS_RESPONSE_TIME seconds (note: if
5135 // their chain has more work than ours, we should sync to it,
5136 // unless it's invalid, in which case we should find that out and
5137 // disconnect from them elsewhere).
5138 if (state.pindexBestKnownBlock != nullptr && state.pindexBestKnownBlock->nChainWork >= m_chainman.ActiveChain().Tip()->nChainWork) {
5139 // 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
5140 if (state.m_chain_sync.m_timeout != 0s) {
5141 state.m_chain_sync.m_timeout = 0s;
5142 state.m_chain_sync.m_work_header = nullptr;
5143 state.m_chain_sync.m_sent_getheaders = false;
5144 }
5145 } 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)) {
5146 // 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
5147 // AND
5148 // we are noticing this for the first time (m_timeout is 0)
5149 // OR we noticed this at some point within the last CHAIN_SYNC_TIMEOUT + HEADERS_RESPONSE_TIME seconds and set a timeout
5150 // 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).
5151 // Either way, set a new timeout based on our current tip.
5152 state.m_chain_sync.m_timeout = time_in_seconds + CHAIN_SYNC_TIMEOUT;
5153 state.m_chain_sync.m_work_header = m_chainman.ActiveChain().Tip();
5154 state.m_chain_sync.m_sent_getheaders = false;
5155 } else if (state.m_chain_sync.m_timeout > 0s && time_in_seconds > state.m_chain_sync.m_timeout) {
5156 // No evidence yet that our peer has synced to a chain with work equal to that
5157 // of our tip, when we first detected it was behind. Send a single getheaders
5158 // message to give the peer a chance to update us.
5159 if (state.m_chain_sync.m_sent_getheaders) {
5160 // They've run out of time to catch up!
5161 LogInfo("Outbound peer has old chain, best known block = %s, %s\n", state.pindexBestKnownBlock != nullptr ? state.pindexBestKnownBlock->GetBlockHash().ToString() : "<none>", pto.DisconnectMsg(fLogIPs));
5162 pto.fDisconnect = true;
5163 } else {
5164 assert(state.m_chain_sync.m_work_header);
5165 // Here, we assume that the getheaders message goes out,
5166 // because it'll either go out or be skipped because of a
5167 // getheaders in-flight already, in which case the peer should
5168 // still respond to us with a sufficiently high work chain tip.
5169 MaybeSendGetHeaders(pto,
5170 GetLocator(state.m_chain_sync.m_work_header->pprev),
5171 peer);
5172 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());
5173 state.m_chain_sync.m_sent_getheaders = true;
5174 // Bump the timeout to allow a response, which could clear the timeout
5175 // (if the response shows the peer has synced), reset the timeout (if
5176 // the peer syncs to the required work but not to our tip), or result
5177 // in disconnect (if we advance to the timeout and pindexBestKnownBlock
5178 // has not sufficiently progressed)
5179 state.m_chain_sync.m_timeout = time_in_seconds + HEADERS_RESPONSE_TIME;
5180 }
5181 }
5182 }
5183 }
5184 5185 void PeerManagerImpl::EvictExtraOutboundPeers(std::chrono::seconds now)
5186 {
5187 // If we have any extra block-relay-only peers, disconnect the youngest unless
5188 // it's given us a block -- in which case, compare with the second-youngest, and
5189 // out of those two, disconnect the peer who least recently gave us a block.
5190 // The youngest block-relay-only peer would be the extra peer we connected
5191 // to temporarily in order to sync our tip; see net.cpp.
5192 // Note that we use higher nodeid as a measure for most recent connection.
5193 if (m_connman.GetExtraBlockRelayCount() > 0) {
5194 std::pair<NodeId, std::chrono::seconds> youngest_peer{-1, 0}, next_youngest_peer{-1, 0};
5195 5196 m_connman.ForEachNode([&](CNode* pnode) {
5197 if (!pnode->IsBlockOnlyConn() || pnode->fDisconnect) return;
5198 if (pnode->GetId() > youngest_peer.first) {
5199 next_youngest_peer = youngest_peer;
5200 youngest_peer.first = pnode->GetId();
5201 youngest_peer.second = pnode->m_last_block_time;
5202 }
5203 });
5204 NodeId to_disconnect = youngest_peer.first;
5205 if (youngest_peer.second > next_youngest_peer.second) {
5206 // Our newest block-relay-only peer gave us a block more recently;
5207 // disconnect our second youngest.
5208 to_disconnect = next_youngest_peer.first;
5209 }
5210 m_connman.ForNode(to_disconnect, [&](CNode* pnode) EXCLUSIVE_LOCKS_REQUIRED(::cs_main) {
5211 AssertLockHeld(::cs_main);
5212 // Make sure we're not getting a block right now, and that
5213 // we've been connected long enough for this eviction to happen
5214 // at all.
5215 // Note that we only request blocks from a peer if we learn of a
5216 // valid headers chain with at least as much work as our tip.
5217 CNodeState *node_state = State(pnode->GetId());
5218 if (node_state == nullptr ||
5219 (now - pnode->m_connected >= MINIMUM_CONNECT_TIME && node_state->vBlocksInFlight.empty())) {
5220 pnode->fDisconnect = true;
5221 LogDebug(BCLog::NET, "disconnecting extra block-relay-only peer=%d (last block received at time %d)\n",
5222 pnode->GetId(), count_seconds(pnode->m_last_block_time));
5223 return true;
5224 } else {
5225 LogDebug(BCLog::NET, "keeping block-relay-only peer=%d chosen for eviction (connect time: %d, blocks_in_flight: %d)\n",
5226 pnode->GetId(), count_seconds(pnode->m_connected), node_state->vBlocksInFlight.size());
5227 }
5228 return false;
5229 });
5230 }
5231 5232 // Check whether we have too many outbound-full-relay peers
5233 if (m_connman.GetExtraFullOutboundCount() > 0) {
5234 // If we have more outbound-full-relay peers than we target, disconnect one.
5235 // Pick the outbound-full-relay peer that least recently announced
5236 // us a new block, with ties broken by choosing the more recent
5237 // connection (higher node id)
5238 // Protect peers from eviction if we don't have another connection
5239 // to their network, counting both outbound-full-relay and manual peers.
5240 NodeId worst_peer = -1;
5241 int64_t oldest_block_announcement = std::numeric_limits<int64_t>::max();
5242 5243 m_connman.ForEachNode([&](CNode* pnode) EXCLUSIVE_LOCKS_REQUIRED(::cs_main, m_connman.GetNodesMutex()) {
5244 AssertLockHeld(::cs_main);
5245 5246 // Only consider outbound-full-relay peers that are not already
5247 // marked for disconnection
5248 if (!pnode->IsFullOutboundConn() || pnode->fDisconnect) return;
5249 CNodeState *state = State(pnode->GetId());
5250 if (state == nullptr) return; // shouldn't be possible, but just in case
5251 // Don't evict our protected peers
5252 if (state->m_chain_sync.m_protect) return;
5253 // If this is the only connection on a particular network that is
5254 // OUTBOUND_FULL_RELAY or MANUAL, protect it.
5255 if (!m_connman.MultipleManualOrFullOutboundConns(pnode->addr.GetNetwork())) return;
5256 if (state->m_last_block_announcement < oldest_block_announcement || (state->m_last_block_announcement == oldest_block_announcement && pnode->GetId() > worst_peer)) {
5257 worst_peer = pnode->GetId();
5258 oldest_block_announcement = state->m_last_block_announcement;
5259 }
5260 });
5261 if (worst_peer != -1) {
5262 bool disconnected = m_connman.ForNode(worst_peer, [&](CNode* pnode) EXCLUSIVE_LOCKS_REQUIRED(::cs_main) {
5263 AssertLockHeld(::cs_main);
5264 5265 // Only disconnect a peer that has been connected to us for
5266 // some reasonable fraction of our check-frequency, to give
5267 // it time for new information to have arrived.
5268 // Also don't disconnect any peer we're trying to download a
5269 // block from.
5270 CNodeState &state = *State(pnode->GetId());
5271 if (now - pnode->m_connected > MINIMUM_CONNECT_TIME && state.vBlocksInFlight.empty()) {
5272 LogDebug(BCLog::NET, "disconnecting extra outbound peer=%d (last block announcement received at time %d)\n", pnode->GetId(), oldest_block_announcement);
5273 pnode->fDisconnect = true;
5274 return true;
5275 } else {
5276 LogDebug(BCLog::NET, "keeping outbound peer=%d chosen for eviction (connect time: %d, blocks_in_flight: %d)\n",
5277 pnode->GetId(), count_seconds(pnode->m_connected), state.vBlocksInFlight.size());
5278 return false;
5279 }
5280 });
5281 if (disconnected) {
5282 // If we disconnected an extra peer, that means we successfully
5283 // connected to at least one peer after the last time we
5284 // detected a stale tip. Don't try any more extra peers until
5285 // we next detect a stale tip, to limit the load we put on the
5286 // network from these extra connections.
5287 m_connman.SetTryNewOutboundPeer(false);
5288 }
5289 }
5290 }
5291 }
5292 5293 void PeerManagerImpl::CheckForStaleTipAndEvictPeers()
5294 {
5295 LOCK(cs_main);
5296 5297 auto now{GetTime<std::chrono::seconds>()};
5298 5299 EvictExtraOutboundPeers(now);
5300 5301 if (now > m_stale_tip_check_time) {
5302 // Check whether our tip is stale, and if so, allow using an extra
5303 // outbound peer
5304 if (!m_chainman.m_blockman.LoadingBlocks() && m_connman.GetNetworkActive() && m_connman.GetUseAddrmanOutgoing() && TipMayBeStale()) {
5305 LogPrintf("Potential stale tip detected, will try using extra outbound peer (last tip update: %d seconds ago)\n",
5306 count_seconds(now - m_last_tip_update.load()));
5307 m_connman.SetTryNewOutboundPeer(true);
5308 } else if (m_connman.GetTryNewOutboundPeer()) {
5309 m_connman.SetTryNewOutboundPeer(false);
5310 }
5311 m_stale_tip_check_time = now + STALE_CHECK_INTERVAL;
5312 }
5313 5314 if (!m_initial_sync_finished && CanDirectFetch()) {
5315 m_connman.StartExtraBlockRelayPeers();
5316 m_initial_sync_finished = true;
5317 }
5318 }
5319 5320 void PeerManagerImpl::MaybeSendPing(CNode& node_to, Peer& peer, std::chrono::microseconds now)
5321 {
5322 if (m_connman.ShouldRunInactivityChecks(node_to, std::chrono::duration_cast<std::chrono::seconds>(now)) &&
5323 peer.m_ping_nonce_sent &&
5324 now > peer.m_ping_start.load() + TIMEOUT_INTERVAL)
5325 {
5326 // The ping timeout is using mocktime. To disable the check during
5327 // testing, increase -peertimeout.
5328 LogDebug(BCLog::NET, "ping timeout: %fs, %s", 0.000001 * count_microseconds(now - peer.m_ping_start.load()), node_to.DisconnectMsg(fLogIPs));
5329 node_to.fDisconnect = true;
5330 return;
5331 }
5332 5333 bool pingSend = false;
5334 5335 if (peer.m_ping_queued) {
5336 // RPC ping request by user
5337 pingSend = true;
5338 }
5339 5340 if (peer.m_ping_nonce_sent == 0 && now > peer.m_ping_start.load() + PING_INTERVAL) {
5341 // Ping automatically sent as a latency probe & keepalive.
5342 pingSend = true;
5343 }
5344 5345 if (pingSend) {
5346 uint64_t nonce;
5347 do {
5348 nonce = FastRandomContext().rand64();
5349 } while (nonce == 0);
5350 peer.m_ping_queued = false;
5351 peer.m_ping_start = now;
5352 if (node_to.GetCommonVersion() > BIP0031_VERSION) {
5353 peer.m_ping_nonce_sent = nonce;
5354 MakeAndPushMessage(node_to, NetMsgType::PING, nonce);
5355 } else {
5356 // Peer is too old to support ping command with nonce, pong will never arrive.
5357 peer.m_ping_nonce_sent = 0;
5358 MakeAndPushMessage(node_to, NetMsgType::PING);
5359 }
5360 }
5361 }
5362 5363 void PeerManagerImpl::MaybeSendAddr(CNode& node, Peer& peer, std::chrono::microseconds current_time)
5364 {
5365 // Nothing to do for non-address-relay peers
5366 if (!peer.m_addr_relay_enabled) return;
5367 5368 LOCK(peer.m_addr_send_times_mutex);
5369 // Periodically advertise our local address to the peer.
5370 if (fListen && !m_chainman.IsInitialBlockDownload() &&
5371 peer.m_next_local_addr_send < current_time) {
5372 // If we've sent before, clear the bloom filter for the peer, so that our
5373 // self-announcement will actually go out.
5374 // This might be unnecessary if the bloom filter has already rolled
5375 // over since our last self-announcement, but there is only a small
5376 // bandwidth cost that we can incur by doing this (which happens
5377 // once a day on average).
5378 if (peer.m_next_local_addr_send != 0us) {
5379 peer.m_addr_known->reset();
5380 }
5381 if (std::optional<CService> local_service = GetLocalAddrForPeer(node)) {
5382 CAddress local_addr{*local_service, peer.m_our_services, Now<NodeSeconds>()};
5383 PushAddress(peer, local_addr);
5384 }
5385 peer.m_next_local_addr_send = current_time + m_rng.rand_exp_duration(AVG_LOCAL_ADDRESS_BROADCAST_INTERVAL);
5386 }
5387 5388 // We sent an `addr` message to this peer recently. Nothing more to do.
5389 if (current_time <= peer.m_next_addr_send) return;
5390 5391 peer.m_next_addr_send = current_time + m_rng.rand_exp_duration(AVG_ADDRESS_BROADCAST_INTERVAL);
5392 5393 if (!Assume(peer.m_addrs_to_send.size() <= MAX_ADDR_TO_SEND)) {
5394 // Should be impossible since we always check size before adding to
5395 // m_addrs_to_send. Recover by trimming the vector.
5396 peer.m_addrs_to_send.resize(MAX_ADDR_TO_SEND);
5397 }
5398 5399 // Remove addr records that the peer already knows about, and add new
5400 // addrs to the m_addr_known filter on the same pass.
5401 auto addr_already_known = [&peer](const CAddress& addr) EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex) {
5402 bool ret = peer.m_addr_known->contains(addr.GetKey());
5403 if (!ret) peer.m_addr_known->insert(addr.GetKey());
5404 return ret;
5405 };
5406 peer.m_addrs_to_send.erase(std::remove_if(peer.m_addrs_to_send.begin(), peer.m_addrs_to_send.end(), addr_already_known),
5407 peer.m_addrs_to_send.end());
5408 5409 // No addr messages to send
5410 if (peer.m_addrs_to_send.empty()) return;
5411 5412 if (peer.m_wants_addrv2) {
5413 MakeAndPushMessage(node, NetMsgType::ADDRV2, CAddress::V2_NETWORK(peer.m_addrs_to_send));
5414 } else {
5415 MakeAndPushMessage(node, NetMsgType::ADDR, CAddress::V1_NETWORK(peer.m_addrs_to_send));
5416 }
5417 peer.m_addrs_to_send.clear();
5418 5419 // we only send the big addr message once
5420 if (peer.m_addrs_to_send.capacity() > 40) {
5421 peer.m_addrs_to_send.shrink_to_fit();
5422 }
5423 }
5424 5425 void PeerManagerImpl::MaybeSendSendHeaders(CNode& node, Peer& peer)
5426 {
5427 // Delay sending SENDHEADERS (BIP 130) until we're done with an
5428 // initial-headers-sync with this peer. Receiving headers announcements for
5429 // new blocks while trying to sync their headers chain is problematic,
5430 // because of the state tracking done.
5431 if (!peer.m_sent_sendheaders && node.GetCommonVersion() >= SENDHEADERS_VERSION) {
5432 LOCK(cs_main);
5433 CNodeState &state = *State(node.GetId());
5434 if (state.pindexBestKnownBlock != nullptr &&
5435 state.pindexBestKnownBlock->nChainWork > m_chainman.MinimumChainWork()) {
5436 // Tell our peer we prefer to receive headers rather than inv's
5437 // We send this to non-NODE NETWORK peers as well, because even
5438 // non-NODE NETWORK peers can announce blocks (such as pruning
5439 // nodes)
5440 MakeAndPushMessage(node, NetMsgType::SENDHEADERS);
5441 peer.m_sent_sendheaders = true;
5442 }
5443 }
5444 }
5445 5446 void PeerManagerImpl::MaybeSendFeefilter(CNode& pto, Peer& peer, std::chrono::microseconds current_time)
5447 {
5448 if (m_opts.ignore_incoming_txs) return;
5449 if (pto.GetCommonVersion() < FEEFILTER_VERSION) return;
5450 if (!gArgs.GetBoolArg("-feefilter", DEFAULT_FEEFILTER)) return;
5451 // peers with the forcerelay permission should not filter txs to us
5452 if (pto.HasPermission(NetPermissionFlags::ForceRelay)) return;
5453 // Don't send feefilter messages to outbound block-relay-only peers since they should never announce
5454 // transactions to us, regardless of feefilter state.
5455 if (pto.IsBlockOnlyConn()) return;
5456 5457 CAmount currentFilter = m_mempool.GetMinFee().GetFeePerK();
5458 5459 if (m_chainman.IsInitialBlockDownload()) {
5460 // Received tx-inv messages are discarded when the active
5461 // chainstate is in IBD, so tell the peer to not send them.
5462 currentFilter = MAX_MONEY;
5463 } else {
5464 static const CAmount MAX_FILTER{m_fee_filter_rounder.round(MAX_MONEY)};
5465 if (peer.m_fee_filter_sent == MAX_FILTER) {
5466 // Send the current filter if we sent MAX_FILTER previously
5467 // and made it out of IBD.
5468 peer.m_next_send_feefilter = 0us;
5469 }
5470 }
5471 if (current_time > peer.m_next_send_feefilter) {
5472 CAmount filterToSend = m_fee_filter_rounder.round(currentFilter);
5473 // We always have a fee filter of at least the min relay fee
5474 filterToSend = std::max(filterToSend, m_mempool.m_opts.min_relay_feerate.GetFeePerK());
5475 if (filterToSend != peer.m_fee_filter_sent) {
5476 MakeAndPushMessage(pto, NetMsgType::FEEFILTER, filterToSend);
5477 peer.m_fee_filter_sent = filterToSend;
5478 }
5479 peer.m_next_send_feefilter = current_time + m_rng.rand_exp_duration(AVG_FEEFILTER_BROADCAST_INTERVAL);
5480 }
5481 // If the fee filter has changed substantially and it's still more than MAX_FEEFILTER_CHANGE_DELAY
5482 // until scheduled broadcast, then move the broadcast to within MAX_FEEFILTER_CHANGE_DELAY.
5483 else if (current_time + MAX_FEEFILTER_CHANGE_DELAY < peer.m_next_send_feefilter &&
5484 (currentFilter < 3 * peer.m_fee_filter_sent / 4 || currentFilter > 4 * peer.m_fee_filter_sent / 3)) {
5485 peer.m_next_send_feefilter = current_time + m_rng.randrange<std::chrono::microseconds>(MAX_FEEFILTER_CHANGE_DELAY);
5486 }
5487 }
5488 5489 namespace {
5490 class CompareInvMempoolOrder
5491 {
5492 CTxMemPool* mp;
5493 bool m_wtxid_relay;
5494 public:
5495 explicit CompareInvMempoolOrder(CTxMemPool *_mempool, bool use_wtxid)
5496 {
5497 mp = _mempool;
5498 m_wtxid_relay = use_wtxid;
5499 }
5500 5501 bool operator()(std::set<uint256>::iterator a, std::set<uint256>::iterator b)
5502 {
5503 /* As std::make_heap produces a max-heap, we want the entries with the
5504 * fewest ancestors/highest fee to sort later. */
5505 return mp->CompareDepthAndScore(*b, *a, m_wtxid_relay);
5506 }
5507 };
5508 } // namespace
5509 5510 bool PeerManagerImpl::RejectIncomingTxs(const CNode& peer) const
5511 {
5512 // block-relay-only peers may never send txs to us
5513 if (peer.IsBlockOnlyConn()) return true;
5514 if (peer.IsFeelerConn()) return true;
5515 // In -blocksonly mode, peers need the 'relay' permission to send txs to us
5516 if (m_opts.ignore_incoming_txs && !peer.HasPermission(NetPermissionFlags::Relay)) return true;
5517 return false;
5518 }
5519 5520 bool PeerManagerImpl::SetupAddressRelay(const CNode& node, Peer& peer)
5521 {
5522 // We don't participate in addr relay with outbound block-relay-only
5523 // connections to prevent providing adversaries with the additional
5524 // information of addr traffic to infer the link.
5525 if (node.IsBlockOnlyConn()) return false;
5526 5527 if (!peer.m_addr_relay_enabled.exchange(true)) {
5528 // During version message processing (non-block-relay-only outbound peers)
5529 // or on first addr-related message we have received (inbound peers), initialize
5530 // m_addr_known.
5531 peer.m_addr_known = std::make_unique<CRollingBloomFilter>(5000, 0.001);
5532 }
5533 5534 return true;
5535 }
5536 5537 bool PeerManagerImpl::SendMessages(CNode* pto)
5538 {
5539 AssertLockNotHeld(m_tx_download_mutex);
5540 AssertLockHeld(g_msgproc_mutex);
5541 5542 PeerRef peer = GetPeerRef(pto->GetId());
5543 if (!peer) return false;
5544 const Consensus::Params& consensusParams = m_chainparams.GetConsensus();
5545 5546 // We must call MaybeDiscourageAndDisconnect first, to ensure that we'll
5547 // disconnect misbehaving peers even before the version handshake is complete.
5548 if (MaybeDiscourageAndDisconnect(*pto, *peer)) return true;
5549 5550 // Initiate version handshake for outbound connections
5551 if (!pto->IsInboundConn() && !peer->m_outbound_version_message_sent) {
5552 PushNodeVersion(*pto, *peer);
5553 peer->m_outbound_version_message_sent = true;
5554 }
5555 5556 // Don't send anything until the version handshake is complete
5557 if (!pto->fSuccessfullyConnected || pto->fDisconnect)
5558 return true;
5559 5560 const auto current_time{GetTime<std::chrono::microseconds>()};
5561 5562 if (pto->IsAddrFetchConn() && current_time - pto->m_connected > 10 * AVG_ADDRESS_BROADCAST_INTERVAL) {
5563 LogDebug(BCLog::NET, "addrfetch connection timeout, %s\n", pto->DisconnectMsg(fLogIPs));
5564 pto->fDisconnect = true;
5565 return true;
5566 }
5567 5568 MaybeSendPing(*pto, *peer, current_time);
5569 5570 // MaybeSendPing may have marked peer for disconnection
5571 if (pto->fDisconnect) return true;
5572 5573 MaybeSendAddr(*pto, *peer, current_time);
5574 5575 MaybeSendSendHeaders(*pto, *peer);
5576 5577 {
5578 LOCK(cs_main);
5579 5580 CNodeState &state = *State(pto->GetId());
5581 5582 // Start block sync
5583 if (m_chainman.m_best_header == nullptr) {
5584 m_chainman.m_best_header = m_chainman.ActiveChain().Tip();
5585 }
5586 5587 // Determine whether we might try initial headers sync or parallel
5588 // block download from this peer -- this mostly affects behavior while
5589 // in IBD (once out of IBD, we sync from all peers).
5590 bool sync_blocks_and_headers_from_peer = false;
5591 if (state.fPreferredDownload) {
5592 sync_blocks_and_headers_from_peer = true;
5593 } else if (CanServeBlocks(*peer) && !pto->IsAddrFetchConn()) {
5594 // Typically this is an inbound peer. If we don't have any outbound
5595 // peers, or if we aren't downloading any blocks from such peers,
5596 // then allow block downloads from this peer, too.
5597 // We prefer downloading blocks from outbound peers to avoid
5598 // putting undue load on (say) some home user who is just making
5599 // outbound connections to the network, but if our only source of
5600 // the latest blocks is from an inbound peer, we have to be sure to
5601 // eventually download it (and not just wait indefinitely for an
5602 // outbound peer to have it).
5603 if (m_num_preferred_download_peers == 0 || mapBlocksInFlight.empty()) {
5604 sync_blocks_and_headers_from_peer = true;
5605 }
5606 }
5607 5608 if (!state.fSyncStarted && CanServeBlocks(*peer) && !m_chainman.m_blockman.LoadingBlocks()) {
5609 // Only actively request headers from a single peer, unless we're close to today.
5610 if ((nSyncStarted == 0 && sync_blocks_and_headers_from_peer) || m_chainman.m_best_header->Time() > NodeClock::now() - 24h) {
5611 const CBlockIndex* pindexStart = m_chainman.m_best_header;
5612 /* If possible, start at the block preceding the currently
5613 best known header. This ensures that we always get a
5614 non-empty list of headers back as long as the peer
5615 is up-to-date. With a non-empty response, we can initialise
5616 the peer's known best block. This wouldn't be possible
5617 if we requested starting at m_chainman.m_best_header and
5618 got back an empty response. */
5619 if (pindexStart->pprev)
5620 pindexStart = pindexStart->pprev;
5621 if (MaybeSendGetHeaders(*pto, GetLocator(pindexStart), *peer)) {
5622 LogDebug(BCLog::NET, "initial getheaders (%d) to peer=%d (startheight:%d)\n", pindexStart->nHeight, pto->GetId(), peer->m_starting_height);
5623 5624 state.fSyncStarted = true;
5625 peer->m_headers_sync_timeout = current_time + HEADERS_DOWNLOAD_TIMEOUT_BASE +
5626 (
5627 // Convert HEADERS_DOWNLOAD_TIMEOUT_PER_HEADER to microseconds before scaling
5628 // to maintain precision
5629 std::chrono::microseconds{HEADERS_DOWNLOAD_TIMEOUT_PER_HEADER} *
5630 Ticks<std::chrono::seconds>(NodeClock::now() - m_chainman.m_best_header->Time()) / consensusParams.nPowTargetSpacing
5631 );
5632 nSyncStarted++;
5633 }
5634 }
5635 }
5636 5637 //
5638 // Try sending block announcements via headers
5639 //
5640 {
5641 // If we have no more than MAX_BLOCKS_TO_ANNOUNCE in our
5642 // list of block hashes we're relaying, and our peer wants
5643 // headers announcements, then find the first header
5644 // not yet known to our peer but would connect, and send.
5645 // If no header would connect, or if we have too many
5646 // blocks, or if the peer doesn't want headers, just
5647 // add all to the inv queue.
5648 LOCK(peer->m_block_inv_mutex);
5649 std::vector<CBlock> vHeaders;
5650 bool fRevertToInv = ((!peer->m_prefers_headers &&
5651 (!state.m_requested_hb_cmpctblocks || peer->m_blocks_for_headers_relay.size() > 1)) ||
5652 peer->m_blocks_for_headers_relay.size() > MAX_BLOCKS_TO_ANNOUNCE);
5653 const CBlockIndex *pBestIndex = nullptr; // last header queued for delivery
5654 ProcessBlockAvailability(pto->GetId()); // ensure pindexBestKnownBlock is up-to-date
5655 5656 if (!fRevertToInv) {
5657 bool fFoundStartingHeader = false;
5658 // Try to find first header that our peer doesn't have, and
5659 // then send all headers past that one. If we come across any
5660 // headers that aren't on m_chainman.ActiveChain(), give up.
5661 for (const uint256& hash : peer->m_blocks_for_headers_relay) {
5662 const CBlockIndex* pindex = m_chainman.m_blockman.LookupBlockIndex(hash);
5663 assert(pindex);
5664 if (m_chainman.ActiveChain()[pindex->nHeight] != pindex) {
5665 // Bail out if we reorged away from this block
5666 fRevertToInv = true;
5667 break;
5668 }
5669 if (pBestIndex != nullptr && pindex->pprev != pBestIndex) {
5670 // This means that the list of blocks to announce don't
5671 // connect to each other.
5672 // This shouldn't really be possible to hit during
5673 // regular operation (because reorgs should take us to
5674 // a chain that has some block not on the prior chain,
5675 // which should be caught by the prior check), but one
5676 // way this could happen is by using invalidateblock /
5677 // reconsiderblock repeatedly on the tip, causing it to
5678 // be added multiple times to m_blocks_for_headers_relay.
5679 // Robustly deal with this rare situation by reverting
5680 // to an inv.
5681 fRevertToInv = true;
5682 break;
5683 }
5684 pBestIndex = pindex;
5685 if (fFoundStartingHeader) {
5686 // add this to the headers message
5687 vHeaders.emplace_back(pindex->GetBlockHeader());
5688 } else if (PeerHasHeader(&state, pindex)) {
5689 continue; // keep looking for the first new block
5690 } else if (pindex->pprev == nullptr || PeerHasHeader(&state, pindex->pprev)) {
5691 // Peer doesn't have this header but they do have the prior one.
5692 // Start sending headers.
5693 fFoundStartingHeader = true;
5694 vHeaders.emplace_back(pindex->GetBlockHeader());
5695 } else {
5696 // Peer doesn't have this header or the prior one -- nothing will
5697 // connect, so bail out.
5698 fRevertToInv = true;
5699 break;
5700 }
5701 }
5702 }
5703 if (!fRevertToInv && !vHeaders.empty()) {
5704 if (vHeaders.size() == 1 && state.m_requested_hb_cmpctblocks) {
5705 // We only send up to 1 block as header-and-ids, as otherwise
5706 // probably means we're doing an initial-ish-sync or they're slow
5707 LogDebug(BCLog::NET, "%s sending header-and-ids %s to peer=%d\n", __func__,
5708 vHeaders.front().GetHash().ToString(), pto->GetId());
5709 5710 std::optional<CSerializedNetMsg> cached_cmpctblock_msg;
5711 {
5712 LOCK(m_most_recent_block_mutex);
5713 if (m_most_recent_block_hash == pBestIndex->GetBlockHash()) {
5714 cached_cmpctblock_msg = NetMsg::Make(NetMsgType::CMPCTBLOCK, *m_most_recent_compact_block);
5715 }
5716 }
5717 if (cached_cmpctblock_msg.has_value()) {
5718 PushMessage(*pto, std::move(cached_cmpctblock_msg.value()));
5719 } else {
5720 CBlock block;
5721 const bool ret{m_chainman.m_blockman.ReadBlock(block, *pBestIndex, /*lowprio=*/true)};
5722 assert(ret);
5723 CBlockHeaderAndShortTxIDs cmpctblock{block, m_rng.rand64()};
5724 MakeAndPushMessage(*pto, NetMsgType::CMPCTBLOCK, cmpctblock);
5725 }
5726 state.pindexBestHeaderSent = pBestIndex;
5727 } else if (peer->m_prefers_headers) {
5728 if (vHeaders.size() > 1) {
5729 LogDebug(BCLog::NET, "%s: %u headers, range (%s, %s), to peer=%d\n", __func__,
5730 vHeaders.size(),
5731 vHeaders.front().GetHash().ToString(),
5732 vHeaders.back().GetHash().ToString(), pto->GetId());
5733 } else {
5734 LogDebug(BCLog::NET, "%s: sending header %s to peer=%d\n", __func__,
5735 vHeaders.front().GetHash().ToString(), pto->GetId());
5736 }
5737 MakeAndPushMessage(*pto, NetMsgType::HEADERS, TX_WITH_WITNESS(vHeaders));
5738 state.pindexBestHeaderSent = pBestIndex;
5739 } else
5740 fRevertToInv = true;
5741 }
5742 if (fRevertToInv) {
5743 // If falling back to using an inv, just try to inv the tip.
5744 // The last entry in m_blocks_for_headers_relay was our tip at some point
5745 // in the past.
5746 if (!peer->m_blocks_for_headers_relay.empty()) {
5747 const uint256& hashToAnnounce = peer->m_blocks_for_headers_relay.back();
5748 const CBlockIndex* pindex = m_chainman.m_blockman.LookupBlockIndex(hashToAnnounce);
5749 assert(pindex);
5750 5751 // Warn if we're announcing a block that is not on the main chain.
5752 // This should be very rare and could be optimized out.
5753 // Just log for now.
5754 if (m_chainman.ActiveChain()[pindex->nHeight] != pindex) {
5755 LogDebug(BCLog::NET, "Announcing block %s not on main chain (tip=%s)\n",
5756 hashToAnnounce.ToString(), m_chainman.ActiveChain().Tip()->GetBlockHash().ToString());
5757 }
5758 5759 // If the peer's chain has this block, don't inv it back.
5760 if (!PeerHasHeader(&state, pindex)) {
5761 peer->m_blocks_for_inv_relay.push_back(hashToAnnounce);
5762 LogDebug(BCLog::NET, "%s: sending inv peer=%d hash=%s\n", __func__,
5763 pto->GetId(), hashToAnnounce.ToString());
5764 }
5765 }
5766 }
5767 peer->m_blocks_for_headers_relay.clear();
5768 }
5769 5770 //
5771 // Message: inventory
5772 //
5773 std::vector<CInv> vInv;
5774 {
5775 LOCK(peer->m_block_inv_mutex);
5776 vInv.reserve(std::max<size_t>(peer->m_blocks_for_inv_relay.size(), INVENTORY_BROADCAST_TARGET));
5777 5778 // Add blocks
5779 for (const uint256& hash : peer->m_blocks_for_inv_relay) {
5780 vInv.emplace_back(MSG_BLOCK, hash);
5781 if (vInv.size() == MAX_INV_SZ) {
5782 MakeAndPushMessage(*pto, NetMsgType::INV, vInv);
5783 vInv.clear();
5784 }
5785 }
5786 peer->m_blocks_for_inv_relay.clear();
5787 }
5788 5789 if (auto tx_relay = peer->GetTxRelay(); tx_relay != nullptr) {
5790 LOCK(tx_relay->m_tx_inventory_mutex);
5791 // Check whether periodic sends should happen
5792 bool fSendTrickle = pto->HasPermission(NetPermissionFlags::NoBan);
5793 if (tx_relay->m_next_inv_send_time < current_time) {
5794 fSendTrickle = true;
5795 if (pto->IsInboundConn()) {
5796 tx_relay->m_next_inv_send_time = NextInvToInbounds(current_time, INBOUND_INVENTORY_BROADCAST_INTERVAL, pto->m_network_key);
5797 } else {
5798 tx_relay->m_next_inv_send_time = current_time + m_rng.rand_exp_duration(OUTBOUND_INVENTORY_BROADCAST_INTERVAL);
5799 }
5800 }
5801 5802 // Time to send but the peer has requested we not relay transactions.
5803 if (fSendTrickle) {
5804 LOCK(tx_relay->m_bloom_filter_mutex);
5805 if (!tx_relay->m_relay_txs) tx_relay->m_tx_inventory_to_send.clear();
5806 }
5807 5808 // Respond to BIP35 mempool requests
5809 if (fSendTrickle && tx_relay->m_send_mempool) {
5810 auto vtxinfo = m_mempool.infoAll();
5811 tx_relay->m_send_mempool = false;
5812 const CFeeRate filterrate{tx_relay->m_fee_filter_received.load()};
5813 5814 LOCK(tx_relay->m_bloom_filter_mutex);
5815 5816 for (const auto& txinfo : vtxinfo) {
5817 CInv inv{
5818 peer->m_wtxid_relay ? MSG_WTX : MSG_TX,
5819 peer->m_wtxid_relay ?
5820 txinfo.tx->GetWitnessHash().ToUint256() :
5821 txinfo.tx->GetHash().ToUint256(),
5822 };
5823 tx_relay->m_tx_inventory_to_send.erase(inv.hash);
5824 5825 // Don't send transactions that peers will not put into their mempool
5826 if (txinfo.fee < filterrate.GetFee(txinfo.vsize)) {
5827 continue;
5828 }
5829 if (tx_relay->m_bloom_filter) {
5830 if (!tx_relay->m_bloom_filter->IsRelevantAndUpdate(*txinfo.tx)) continue;
5831 }
5832 tx_relay->m_tx_inventory_known_filter.insert(inv.hash);
5833 vInv.push_back(inv);
5834 if (vInv.size() == MAX_INV_SZ) {
5835 MakeAndPushMessage(*pto, NetMsgType::INV, vInv);
5836 vInv.clear();
5837 }
5838 }
5839 }
5840 5841 // Determine transactions to relay
5842 if (fSendTrickle) {
5843 // Produce a vector with all candidates for sending
5844 std::vector<std::set<uint256>::iterator> vInvTx;
5845 vInvTx.reserve(tx_relay->m_tx_inventory_to_send.size());
5846 for (std::set<uint256>::iterator it = tx_relay->m_tx_inventory_to_send.begin(); it != tx_relay->m_tx_inventory_to_send.end(); it++) {
5847 vInvTx.push_back(it);
5848 }
5849 const CFeeRate filterrate{tx_relay->m_fee_filter_received.load()};
5850 // Topologically and fee-rate sort the inventory we send for privacy and priority reasons.
5851 // A heap is used so that not all items need sorting if only a few are being sent.
5852 CompareInvMempoolOrder compareInvMempoolOrder(&m_mempool, peer->m_wtxid_relay);
5853 std::make_heap(vInvTx.begin(), vInvTx.end(), compareInvMempoolOrder);
5854 // No reason to drain out at many times the network's capacity,
5855 // especially since we have many peers and some will draw much shorter delays.
5856 unsigned int nRelayedTransactions = 0;
5857 LOCK(tx_relay->m_bloom_filter_mutex);
5858 size_t broadcast_max{INVENTORY_BROADCAST_TARGET + (tx_relay->m_tx_inventory_to_send.size()/1000)*5};
5859 broadcast_max = std::min<size_t>(INVENTORY_BROADCAST_MAX, broadcast_max);
5860 while (!vInvTx.empty() && nRelayedTransactions < broadcast_max) {
5861 // Fetch the top element from the heap
5862 std::pop_heap(vInvTx.begin(), vInvTx.end(), compareInvMempoolOrder);
5863 std::set<uint256>::iterator it = vInvTx.back();
5864 vInvTx.pop_back();
5865 uint256 hash = *it;
5866 CInv inv(peer->m_wtxid_relay ? MSG_WTX : MSG_TX, hash);
5867 // Remove it from the to-be-sent set
5868 tx_relay->m_tx_inventory_to_send.erase(it);
5869 // Check if not in the filter already
5870 if (tx_relay->m_tx_inventory_known_filter.contains(hash)) {
5871 continue;
5872 }
5873 // Not in the mempool anymore? don't bother sending it.
5874 auto txinfo = m_mempool.info(ToGenTxid(inv));
5875 if (!txinfo.tx) {
5876 continue;
5877 }
5878 // Peer told you to not send transactions at that feerate? Don't bother sending it.
5879 if (txinfo.fee < filterrate.GetFee(txinfo.vsize)) {
5880 continue;
5881 }
5882 if (tx_relay->m_bloom_filter && !tx_relay->m_bloom_filter->IsRelevantAndUpdate(*txinfo.tx)) continue;
5883 // Send
5884 vInv.push_back(inv);
5885 nRelayedTransactions++;
5886 if (vInv.size() == MAX_INV_SZ) {
5887 MakeAndPushMessage(*pto, NetMsgType::INV, vInv);
5888 vInv.clear();
5889 }
5890 tx_relay->m_tx_inventory_known_filter.insert(hash);
5891 }
5892 5893 // Ensure we'll respond to GETDATA requests for anything we've just announced
5894 LOCK(m_mempool.cs);
5895 tx_relay->m_last_inv_sequence = m_mempool.GetSequence();
5896 }
5897 }
5898 if (!vInv.empty())
5899 MakeAndPushMessage(*pto, NetMsgType::INV, vInv);
5900 5901 // Detect whether we're stalling
5902 auto stalling_timeout = m_block_stalling_timeout.load();
5903 if (state.m_stalling_since.count() && state.m_stalling_since < current_time - stalling_timeout) {
5904 // Stalling only triggers when the block download window cannot move. During normal steady state,
5905 // the download window should be much larger than the to-be-downloaded set of blocks, so disconnection
5906 // should only happen during initial block download.
5907 LogInfo("Peer is stalling block download, %s\n", pto->DisconnectMsg(fLogIPs));
5908 pto->fDisconnect = true;
5909 // Increase timeout for the next peer so that we don't disconnect multiple peers if our own
5910 // bandwidth is insufficient.
5911 const auto new_timeout = std::min(2 * stalling_timeout, BLOCK_STALLING_TIMEOUT_MAX);
5912 if (stalling_timeout != new_timeout && m_block_stalling_timeout.compare_exchange_strong(stalling_timeout, new_timeout)) {
5913 LogDebug(BCLog::NET, "Increased stalling timeout temporarily to %d seconds\n", count_seconds(new_timeout));
5914 }
5915 return true;
5916 }
5917 // In case there is a block that has been in flight from this peer for block_interval * (1 + 0.5 * N)
5918 // (with N the number of peers from which we're downloading validated blocks), disconnect due to timeout.
5919 // We compensate for other peers to prevent killing off peers due to our own downstream link
5920 // being saturated. We only count validated in-flight blocks so peers can't advertise non-existing block hashes
5921 // to unreasonably increase our timeout.
5922 if (state.vBlocksInFlight.size() > 0) {
5923 QueuedBlock &queuedBlock = state.vBlocksInFlight.front();
5924 int nOtherPeersWithValidatedDownloads = m_peers_downloading_from - 1;
5925 if (current_time > state.m_downloading_since + std::chrono::seconds{consensusParams.nPowTargetSpacing} * (BLOCK_DOWNLOAD_TIMEOUT_BASE + BLOCK_DOWNLOAD_TIMEOUT_PER_PEER * nOtherPeersWithValidatedDownloads)) {
5926 LogInfo("Timeout downloading block %s, %s\n", queuedBlock.pindex->GetBlockHash().ToString(), pto->DisconnectMsg(fLogIPs));
5927 pto->fDisconnect = true;
5928 return true;
5929 }
5930 }
5931 // Check for headers sync timeouts
5932 if (state.fSyncStarted && peer->m_headers_sync_timeout < std::chrono::microseconds::max()) {
5933 // Detect whether this is a stalling initial-headers-sync peer
5934 if (m_chainman.m_best_header->Time() <= NodeClock::now() - 24h) {
5935 if (current_time > peer->m_headers_sync_timeout && nSyncStarted == 1 && (m_num_preferred_download_peers - state.fPreferredDownload >= 1)) {
5936 // Disconnect a peer (without NetPermissionFlags::NoBan permission) if it is our only sync peer,
5937 // and we have others we could be using instead.
5938 // Note: If all our peers are inbound, then we won't
5939 // disconnect our sync peer for stalling; we have bigger
5940 // problems if we can't get any outbound peers.
5941 if (!pto->HasPermission(NetPermissionFlags::NoBan)) {
5942 LogInfo("Timeout downloading headers, %s\n", pto->DisconnectMsg(fLogIPs));
5943 pto->fDisconnect = true;
5944 return true;
5945 } else {
5946 LogInfo("Timeout downloading headers from noban peer, not %s\n", pto->DisconnectMsg(fLogIPs));
5947 // Reset the headers sync state so that we have a
5948 // chance to try downloading from a different peer.
5949 // Note: this will also result in at least one more
5950 // getheaders message to be sent to
5951 // this peer (eventually).
5952 state.fSyncStarted = false;
5953 nSyncStarted--;
5954 peer->m_headers_sync_timeout = 0us;
5955 }
5956 }
5957 } else {
5958 // After we've caught up once, reset the timeout so we can't trigger
5959 // disconnect later.
5960 peer->m_headers_sync_timeout = std::chrono::microseconds::max();
5961 }
5962 }
5963 5964 // Check that outbound peers have reasonable chains
5965 // GetTime() is used by this anti-DoS logic so we can test this using mocktime
5966 ConsiderEviction(*pto, *peer, GetTime<std::chrono::seconds>());
5967 5968 //
5969 // Message: getdata (blocks)
5970 //
5971 std::vector<CInv> vGetData;
5972 if (CanServeBlocks(*peer) && ((sync_blocks_and_headers_from_peer && !IsLimitedPeer(*peer)) || !m_chainman.IsInitialBlockDownload()) && state.vBlocksInFlight.size() < MAX_BLOCKS_IN_TRANSIT_PER_PEER) {
5973 std::vector<const CBlockIndex*> vToDownload;
5974 NodeId staller = -1;
5975 auto get_inflight_budget = [&state]() {
5976 return std::max(0, MAX_BLOCKS_IN_TRANSIT_PER_PEER - static_cast<int>(state.vBlocksInFlight.size()));
5977 };
5978 5979 // If a snapshot chainstate is in use, we want to find its next blocks
5980 // before the background chainstate to prioritize getting to network tip.
5981 FindNextBlocksToDownload(*peer, get_inflight_budget(), vToDownload, staller);
5982 if (m_chainman.BackgroundSyncInProgress() && !IsLimitedPeer(*peer)) {
5983 // If the background tip is not an ancestor of the snapshot block,
5984 // we need to start requesting blocks from their last common ancestor.
5985 const CBlockIndex *from_tip = LastCommonAncestor(m_chainman.GetBackgroundSyncTip(), m_chainman.GetSnapshotBaseBlock());
5986 TryDownloadingHistoricalBlocks(
5987 *peer,
5988 get_inflight_budget(),
5989 vToDownload, from_tip,
5990 Assert(m_chainman.GetSnapshotBaseBlock()));
5991 }
5992 for (const CBlockIndex *pindex : vToDownload) {
5993 uint32_t nFetchFlags = GetFetchFlags(*peer);
5994 vGetData.emplace_back(MSG_BLOCK | nFetchFlags, pindex->GetBlockHash());
5995 BlockRequested(pto->GetId(), *pindex);
5996 LogDebug(BCLog::NET, "Requesting block %s (%d) peer=%d\n", pindex->GetBlockHash().ToString(),
5997 pindex->nHeight, pto->GetId());
5998 }
5999 if (state.vBlocksInFlight.empty() && staller != -1) {
6000 if (State(staller)->m_stalling_since == 0us) {
6001 State(staller)->m_stalling_since = current_time;
6002 LogDebug(BCLog::NET, "Stall started peer=%d\n", staller);
6003 }
6004 }
6005 }
6006 6007 //
6008 // Message: getdata (transactions)
6009 //
6010 {
6011 LOCK(m_tx_download_mutex);
6012 for (const GenTxid& gtxid : m_txdownloadman.GetRequestsToSend(pto->GetId(), current_time)) {
6013 vGetData.emplace_back(gtxid.IsWtxid() ? MSG_WTX : (MSG_TX | GetFetchFlags(*peer)), gtxid.GetHash());
6014 if (vGetData.size() >= MAX_GETDATA_SZ) {
6015 MakeAndPushMessage(*pto, NetMsgType::GETDATA, vGetData);
6016 vGetData.clear();
6017 }
6018 }
6019 }
6020 6021 if (!vGetData.empty())
6022 MakeAndPushMessage(*pto, NetMsgType::GETDATA, vGetData);
6023 } // release cs_main
6024 MaybeSendFeefilter(*pto, *peer, current_time);
6025 return true;
6026 }
6027