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// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2020 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#include <net_processing.h>
#include <addrman.h>
#include <banman.h>
#include <blockencodings.h>
#include <chainparams.h>
#include <consensus/validation.h>
#include <hash.h>
#include <validation.h>
#include <merkleblock.h>
#include <netmessagemaker.h>
#include <netbase.h>
#include <policy/fees.h>
#include <policy/policy.h>
#include <primitives/block.h>
#include <primitives/transaction.h>
#include <random.h>
#include <reverse_iterator.h>
#include <scheduler.h>
#include <tinyformat.h>
#include <txmempool.h>
#include <util/system.h>
#include <util/strencodings.h>
#include <memory>
#include <typeinfo>
#if defined(NDEBUG)
# error "Bitcoin cannot be compiled without assertions."
#endif
/** Expiration time for orphan transactions in seconds */
static constexpr int64_t ORPHAN_TX_EXPIRE_TIME = 20 * 60;
/** Minimum time between orphan transactions expire time checks in seconds */
static constexpr int64_t ORPHAN_TX_EXPIRE_INTERVAL = 5 * 60;
/** How long to cache transactions in mapRelay for normal relay */
static constexpr std::chrono::seconds RELAY_TX_CACHE_TIME{15 * 60};
/** Headers download timeout expressed in microseconds
* Timeout = base + per_header * (expected number of headers) */
static constexpr int64_t HEADERS_DOWNLOAD_TIMEOUT_BASE = 15 * 60 * 1000000; // 15 minutes
static constexpr int64_t HEADERS_DOWNLOAD_TIMEOUT_PER_HEADER = 1000; // 1ms/header
/** Protect at least this many outbound peers from disconnection due to slow/
* behind headers chain.
*/
static constexpr int32_t MAX_OUTBOUND_PEERS_TO_PROTECT_FROM_DISCONNECT = 4;
/** Timeout for (unprotected) outbound peers to sync to our chainwork, in seconds */
static constexpr int64_t CHAIN_SYNC_TIMEOUT = 20 * 60; // 20 minutes
/** How frequently to check for stale tips, in seconds */
static constexpr int64_t STALE_CHECK_INTERVAL = 10 * 60; // 10 minutes
/** How frequently to check for extra outbound peers and disconnect, in seconds */
static constexpr int64_t EXTRA_PEER_CHECK_INTERVAL = 45;
/** Minimum time an outbound-peer-eviction candidate must be connected for, in order to evict, in seconds */
static constexpr int64_t MINIMUM_CONNECT_TIME = 30;
/** SHA256("main address relay")[0:8] */
static constexpr uint64_t RANDOMIZER_ID_ADDRESS_RELAY = 0x3cac0035b5866b90ULL;
/// Age after which a stale block will no longer be served if requested as
/// protection against fingerprinting. Set to one month, denominated in seconds.
static constexpr int STALE_RELAY_AGE_LIMIT = 30 * 24 * 60 * 60;
/// Age after which a block is considered historical for purposes of rate
/// limiting block relay. Set to one week, denominated in seconds.
static constexpr int HISTORICAL_BLOCK_AGE = 7 * 24 * 60 * 60;
/** Maximum number of in-flight transactions from a peer */
static constexpr int32_t MAX_PEER_TX_IN_FLIGHT = 100;
/** Maximum number of announced transactions from a peer */
static constexpr int32_t MAX_PEER_TX_ANNOUNCEMENTS = 2 * MAX_INV_SZ;
/** How many microseconds to delay requesting transactions from inbound peers */
static constexpr std::chrono::microseconds INBOUND_PEER_TX_DELAY{std::chrono::seconds{2}};
/** How long to wait (in microseconds) before downloading a transaction from an additional peer */
static constexpr std::chrono::microseconds GETDATA_TX_INTERVAL{std::chrono::seconds{60}};
/** Maximum delay (in microseconds) for transaction requests to avoid biasing some peers over others. */
static constexpr std::chrono::microseconds MAX_GETDATA_RANDOM_DELAY{std::chrono::seconds{2}};
/** How long to wait (in microseconds) before expiring an in-flight getdata request to a peer */
static constexpr std::chrono::microseconds TX_EXPIRY_INTERVAL{GETDATA_TX_INTERVAL * 10};
static_assert(INBOUND_PEER_TX_DELAY >= MAX_GETDATA_RANDOM_DELAY,
"To preserve security, MAX_GETDATA_RANDOM_DELAY should not exceed INBOUND_PEER_DELAY");
/** Limit to avoid sending big packets. Not used in processing incoming GETDATA for compatibility */
static const unsigned int MAX_GETDATA_SZ = 1000;
struct COrphanTx {
// When modifying, adapt the copy of this definition in tests/DoS_tests.
CTransactionRef tx;
NodeId fromPeer;
int64_t nTimeExpire;
size_t list_pos;
};
RecursiveMutex g_cs_orphans;
std::map<uint256, COrphanTx> mapOrphanTransactions GUARDED_BY(g_cs_orphans);
void EraseOrphansFor(NodeId peer);
/** Increase a node's misbehavior score. */
void Misbehaving(NodeId nodeid, int howmuch, const std::string& message="") EXCLUSIVE_LOCKS_REQUIRED(cs_main);
/** Average delay between local address broadcasts in seconds. */
static constexpr unsigned int AVG_LOCAL_ADDRESS_BROADCAST_INTERVAL = 24 * 60 * 60;
/** Average delay between peer address broadcasts in seconds. */
static const unsigned int AVG_ADDRESS_BROADCAST_INTERVAL = 30;
/** Average delay between trickled inventory transmissions in seconds.
* Blocks and whitelisted receivers bypass this, outbound peers get half this delay. */
static const unsigned int INVENTORY_BROADCAST_INTERVAL = 5;
/** Maximum number of inventory items to send per transmission.
* Limits the impact of low-fee transaction floods. */
static constexpr unsigned int INVENTORY_BROADCAST_MAX = 7 * INVENTORY_BROADCAST_INTERVAL;
/** Average delay between feefilter broadcasts in seconds. */
static constexpr unsigned int AVG_FEEFILTER_BROADCAST_INTERVAL = 10 * 60;
/** Maximum feefilter broadcast delay after significant change. */
static constexpr unsigned int MAX_FEEFILTER_CHANGE_DELAY = 5 * 60;
// Internal stuff
namespace {
/** Number of nodes with fSyncStarted. */
int nSyncStarted GUARDED_BY(cs_main) = 0;
/**
* Sources of received blocks, saved to be able punish them when processing
* happens afterwards.
* Set mapBlockSource[hash].second to false if the node should not be
* punished if the block is invalid.
*/
std::map<uint256, std::pair<NodeId, bool>> mapBlockSource GUARDED_BY(cs_main);
/**
* Filter for transactions that were recently rejected by
* AcceptToMemoryPool. These are not rerequested until the chain tip
* changes, at which point the entire filter is reset.
*
* Without this filter we'd be re-requesting txs from each of our peers,
* increasing bandwidth consumption considerably. For instance, with 100
* peers, half of which relay a tx we don't accept, that might be a 50x
* bandwidth increase. A flooding attacker attempting to roll-over the
* filter using minimum-sized, 60byte, transactions might manage to send
* 1000/sec if we have fast peers, so we pick 120,000 to give our peers a
* two minute window to send invs to us.
*
* Decreasing the false positive rate is fairly cheap, so we pick one in a
* million to make it highly unlikely for users to have issues with this
* filter.
*
* Memory used: 1.3 MB
*/
std::unique_ptr<CRollingBloomFilter> recentRejects GUARDED_BY(cs_main);
uint256 hashRecentRejectsChainTip GUARDED_BY(cs_main);
/*
* Filter for transactions that have been recently confirmed.
* We use this to avoid requesting transactions that have already been
* confirnmed.
*/
RecursiveMutex g_cs_recent_confirmed_transactions;
std::unique_ptr<CRollingBloomFilter> g_recent_confirmed_transactions GUARDED_BY(g_cs_recent_confirmed_transactions);
/** Blocks that are in flight, and that are in the queue to be downloaded. */
struct QueuedBlock {
uint256 hash;
const CBlockIndex* pindex; //!< Optional.
bool fValidatedHeaders; //!< Whether this block has validated headers at the time of request.
std::unique_ptr<PartiallyDownloadedBlock> partialBlock; //!< Optional, used for CMPCTBLOCK downloads
};
std::map<uint256, std::pair<NodeId, std::list<QueuedBlock>::iterator> > mapBlocksInFlight GUARDED_BY(cs_main);
/** Stack of nodes which we have set to announce using compact blocks */
std::list<NodeId> lNodesAnnouncingHeaderAndIDs GUARDED_BY(cs_main);
/** Number of preferable block download peers. */
int nPreferredDownload GUARDED_BY(cs_main) = 0;
/** Number of peers from which we're downloading blocks. */
int nPeersWithValidatedDownloads GUARDED_BY(cs_main) = 0;
/** Number of outbound peers with m_chain_sync.m_protect. */
int g_outbound_peers_with_protect_from_disconnect GUARDED_BY(cs_main) = 0;
/** When our tip was last updated. */
std::atomic<int64_t> g_last_tip_update(0);
/** Relay map */
typedef std::map<uint256, CTransactionRef> MapRelay;
MapRelay mapRelay GUARDED_BY(cs_main);
/** Expiration-time ordered list of (expire time, relay map entry) pairs. */
std::deque<std::pair<int64_t, MapRelay::iterator>> vRelayExpiration GUARDED_BY(cs_main);
struct IteratorComparator
{
template<typename I>
bool operator()(const I& a, const I& b) const
{
return &(*a) < &(*b);
}
};
std::map<COutPoint, std::set<std::map<uint256, COrphanTx>::iterator, IteratorComparator>> mapOrphanTransactionsByPrev GUARDED_BY(g_cs_orphans);
std::vector<std::map<uint256, COrphanTx>::iterator> g_orphan_list GUARDED_BY(g_cs_orphans); //! For random eviction
static size_t vExtraTxnForCompactIt GUARDED_BY(g_cs_orphans) = 0;
static std::vector<std::pair<uint256, CTransactionRef>> vExtraTxnForCompact GUARDED_BY(g_cs_orphans);
} // namespace
namespace {
/**
* Maintain validation-specific state about nodes, protected by cs_main, instead
* by CNode's own locks. This simplifies asynchronous operation, where
* processing of incoming data is done after the ProcessMessage call returns,
* and we're no longer holding the node's locks.
*/
struct CNodeState {
//! The peer's address
const CService address;
//! Whether we have a fully established connection.
bool fCurrentlyConnected;
//! Accumulated misbehaviour score for this peer.
int nMisbehavior;
//! Whether this peer should be disconnected and banned (unless whitelisted).
bool fShouldBan;
//! String name of this peer (debugging/logging purposes).
const std::string name;
//! The best known block we know this peer has announced.
const CBlockIndex *pindexBestKnownBlock;
//! The hash of the last unknown block this peer has announced.
uint256 hashLastUnknownBlock;
//! The last full block we both have.
const CBlockIndex *pindexLastCommonBlock;
//! The best header we have sent our peer.
const CBlockIndex *pindexBestHeaderSent;
//! Length of current-streak of unconnecting headers announcements
int nUnconnectingHeaders;
//! Whether we've started headers synchronization with this peer.
bool fSyncStarted;
//! When to potentially disconnect peer for stalling headers download
int64_t nHeadersSyncTimeout;
//! Since when we're stalling block download progress (in microseconds), or 0.
int64_t nStallingSince;
std::list<QueuedBlock> vBlocksInFlight;
//! When the first entry in vBlocksInFlight started downloading. Don't care when vBlocksInFlight is empty.
int64_t nDownloadingSince;
int nBlocksInFlight;
int nBlocksInFlightValidHeaders;
//! Whether we consider this a preferred download peer.
bool fPreferredDownload;
//! Whether this peer wants invs or headers (when possible) for block announcements.
bool fPreferHeaders;
//! Whether this peer wants invs or cmpctblocks (when possible) for block announcements.
bool fPreferHeaderAndIDs;
/**
* Whether this peer will send us cmpctblocks if we request them.
* This is not used to gate request logic, as we really only care about fSupportsDesiredCmpctVersion,
* but is used as a flag to "lock in" the version of compact blocks (fWantsCmpctWitness) we send.
*/
bool fProvidesHeaderAndIDs;
//! Whether this peer can give us witnesses
bool fHaveWitness;
//! Whether this peer wants witnesses in cmpctblocks/blocktxns
bool fWantsCmpctWitness;
/**
* If we've announced NODE_WITNESS to this peer: whether the peer sends witnesses in cmpctblocks/blocktxns,
* otherwise: whether this peer sends non-witnesses in cmpctblocks/blocktxns.
*/
bool fSupportsDesiredCmpctVersion;
/** State used to enforce CHAIN_SYNC_TIMEOUT
* Only in effect for outbound, non-manual, full-relay connections, with
* m_protect == false
* Algorithm: if a peer's best known block has less work than our tip,
* set a timeout CHAIN_SYNC_TIMEOUT seconds in the future:
* - If at timeout their best known block now has more work than our tip
* when the timeout was set, then either reset the timeout or clear it
* (after comparing against our current tip's work)
* - If at timeout their best known block still has less work than our
* tip did when the timeout was set, then send a getheaders message,
* and set a shorter timeout, HEADERS_RESPONSE_TIME seconds in future.
* If their best known block is still behind when that new timeout is
* reached, disconnect.
*/
struct ChainSyncTimeoutState {
//! A timeout used for checking whether our peer has sufficiently synced
int64_t m_timeout;
//! A header with the work we require on our peer's chain
const CBlockIndex * m_work_header;
//! After timeout is reached, set to true after sending getheaders
bool m_sent_getheaders;
//! Whether this peer is protected from disconnection due to a bad/slow chain
bool m_protect;
};
ChainSyncTimeoutState m_chain_sync;
//! Time of last new block announcement
int64_t m_last_block_announcement;
/*
* State associated with transaction download.
*
* Tx download algorithm:
*
* When inv comes in, queue up (process_time, txid) inside the peer's
* CNodeState (m_tx_process_time) as long as m_tx_announced for the peer
* isn't too big (MAX_PEER_TX_ANNOUNCEMENTS).
*
* The process_time for a transaction is set to nNow for outbound peers,
* nNow + 2 seconds for inbound peers. This is the time at which we'll
* consider trying to request the transaction from the peer in
* SendMessages(). The delay for inbound peers is to allow outbound peers
* a chance to announce before we request from inbound peers, to prevent
* an adversary from using inbound connections to blind us to a
* transaction (InvBlock).
*
* When we call SendMessages() for a given peer,
* we will loop over the transactions in m_tx_process_time, looking
* at the transactions whose process_time <= nNow. We'll request each
* such transaction that we don't have already and that hasn't been
* requested from another peer recently, up until we hit the
* MAX_PEER_TX_IN_FLIGHT limit for the peer. Then we'll update
* g_already_asked_for for each requested txid, storing the time of the
* GETDATA request. We use g_already_asked_for to coordinate transaction
* requests amongst our peers.
*
* For transactions that we still need but we have already recently
* requested from some other peer, we'll reinsert (process_time, txid)
* back into the peer's m_tx_process_time at the point in the future at
* which the most recent GETDATA request would time out (ie
* GETDATA_TX_INTERVAL + the request time stored in g_already_asked_for).
* We add an additional delay for inbound peers, again to prefer
* attempting download from outbound peers first.
* We also add an extra small random delay up to 2 seconds
* to avoid biasing some peers over others. (e.g., due to fixed ordering
* of peer processing in ThreadMessageHandler).
*
* When we receive a transaction from a peer, we remove the txid from the
* peer's m_tx_in_flight set and from their recently announced set
* (m_tx_announced). We also clear g_already_asked_for for that entry, so
* that if somehow the transaction is not accepted but also not added to
* the reject filter, then we will eventually redownload from other
* peers.
*/
struct TxDownloadState {
/* Track when to attempt download of announced transactions (process
* time in micros -> txid)
*/
std::multimap<std::chrono::microseconds, uint256> m_tx_process_time;
//! Store all the transactions a peer has recently announced
std::set<uint256> m_tx_announced;
//! Store transactions which were requested by us, with timestamp
std::map<uint256, std::chrono::microseconds> m_tx_in_flight;
//! Periodically check for stuck getdata requests
std::chrono::microseconds m_check_expiry_timer{0};
};
TxDownloadState m_tx_download;
//! Whether this peer is an inbound connection
bool m_is_inbound;
//! Whether this peer is a manual connection
bool m_is_manual_connection;
CNodeState(CAddress addrIn, std::string addrNameIn, bool is_inbound, bool is_manual) :
address(addrIn), name(std::move(addrNameIn)), m_is_inbound(is_inbound),
m_is_manual_connection (is_manual)
{
fCurrentlyConnected = false;
nMisbehavior = 0;
fShouldBan = false;
pindexBestKnownBlock = nullptr;
hashLastUnknownBlock.SetNull();
pindexLastCommonBlock = nullptr;
pindexBestHeaderSent = nullptr;
nUnconnectingHeaders = 0;
fSyncStarted = false;
nHeadersSyncTimeout = 0;
nStallingSince = 0;
nDownloadingSince = 0;
nBlocksInFlight = 0;
nBlocksInFlightValidHeaders = 0;
fPreferredDownload = false;
fPreferHeaders = false;
fPreferHeaderAndIDs = false;
fProvidesHeaderAndIDs = false;
fHaveWitness = false;
fWantsCmpctWitness = false;
fSupportsDesiredCmpctVersion = false;
m_chain_sync = { 0, nullptr, false, false };
m_last_block_announcement = 0;
}
};
// Keeps track of the time (in microseconds) when transactions were requested last time
limitedmap<uint256, std::chrono::microseconds> g_already_asked_for GUARDED_BY(cs_main)(MAX_INV_SZ);
/** Map maintaining per-node state. */
static std::map<NodeId, CNodeState> mapNodeState GUARDED_BY(cs_main);
static CNodeState *State(NodeId pnode) EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
std::map<NodeId, CNodeState>::iterator it = mapNodeState.find(pnode);
if (it == mapNodeState.end())
return nullptr;
return &it->second;
}
static void UpdatePreferredDownload(CNode* node, CNodeState* state) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
{
nPreferredDownload -= state->fPreferredDownload;
// Whether this node should be marked as a preferred download node.
state->fPreferredDownload = (!node->fInbound || node->HasPermission(PF_NOBAN)) && !node->fOneShot && !node->fClient;
nPreferredDownload += state->fPreferredDownload;
}
static void PushNodeVersion(CNode *pnode, CConnman* connman, int64_t nTime)
{
// Note that pnode->GetLocalServices() is a reflection of the local
// services we were offering when the CNode object was created for this
// peer.
ServiceFlags nLocalNodeServices = pnode->GetLocalServices();
uint64_t nonce = pnode->GetLocalNonce();
int nNodeStartingHeight = pnode->GetMyStartingHeight();
NodeId nodeid = pnode->GetId();
CAddress addr = pnode->addr;
CAddress addrYou = (addr.IsRoutable() && !IsProxy(addr) ? addr : CAddress(CService(), addr.nServices));
CAddress addrMe = CAddress(CService(), nLocalNodeServices);
connman->PushMessage(pnode, CNetMsgMaker(INIT_PROTO_VERSION).Make(NetMsgType::VERSION, PROTOCOL_VERSION, (uint64_t)nLocalNodeServices, nTime, addrYou, addrMe,
nonce, strSubVersion, nNodeStartingHeight, ::g_relay_txes && pnode->m_tx_relay != nullptr));
if (fLogIPs) {
LogPrint(BCLog::NET, "send version message: version %d, blocks=%d, us=%s, them=%s, peer=%d\n", PROTOCOL_VERSION, nNodeStartingHeight, addrMe.ToString(), addrYou.ToString(), nodeid);
} else {
LogPrint(BCLog::NET, "send version message: version %d, blocks=%d, us=%s, peer=%d\n", PROTOCOL_VERSION, nNodeStartingHeight, addrMe.ToString(), nodeid);
}
}
// Returns a bool indicating whether we requested this block.
// Also used if a block was /not/ received and timed out or started with another peer
static bool MarkBlockAsReceived(const uint256& hash) EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
std::map<uint256, std::pair<NodeId, std::list<QueuedBlock>::iterator> >::iterator itInFlight = mapBlocksInFlight.find(hash);
if (itInFlight != mapBlocksInFlight.end()) {
CNodeState *state = State(itInFlight->second.first);
assert(state != nullptr);
state->nBlocksInFlightValidHeaders -= itInFlight->second.second->fValidatedHeaders;
if (state->nBlocksInFlightValidHeaders == 0 && itInFlight->second.second->fValidatedHeaders) {
// Last validated block on the queue was received.
nPeersWithValidatedDownloads--;
}
if (state->vBlocksInFlight.begin() == itInFlight->second.second) {
// First block on the queue was received, update the start download time for the next one
state->nDownloadingSince = std::max(state->nDownloadingSince, GetTimeMicros());
}
state->vBlocksInFlight.erase(itInFlight->second.second);
state->nBlocksInFlight--;
state->nStallingSince = 0;
mapBlocksInFlight.erase(itInFlight);
return true;
}
return false;
}
// returns false, still setting pit, if the block was already in flight from the same peer
// pit will only be valid as long as the same cs_main lock is being held
static bool MarkBlockAsInFlight(CTxMemPool& mempool, NodeId nodeid, const uint256& hash, const CBlockIndex* pindex = nullptr, std::list<QueuedBlock>::iterator** pit = nullptr) EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
CNodeState *state = State(nodeid);
assert(state != nullptr);
// Short-circuit most stuff in case it is from the same node
std::map<uint256, std::pair<NodeId, std::list<QueuedBlock>::iterator> >::iterator itInFlight = mapBlocksInFlight.find(hash);
if (itInFlight != mapBlocksInFlight.end() && itInFlight->second.first == nodeid) {
if (pit) {
*pit = &itInFlight->second.second;
}
return false;
}
// Make sure it's not listed somewhere already.
MarkBlockAsReceived(hash);
std::list<QueuedBlock>::iterator it = state->vBlocksInFlight.insert(state->vBlocksInFlight.end(),
{hash, pindex, pindex != nullptr, std::unique_ptr<PartiallyDownloadedBlock>(pit ? new PartiallyDownloadedBlock(&mempool) : nullptr)});
state->nBlocksInFlight++;
state->nBlocksInFlightValidHeaders += it->fValidatedHeaders;
if (state->nBlocksInFlight == 1) {
// We're starting a block download (batch) from this peer.
state->nDownloadingSince = GetTimeMicros();
}
if (state->nBlocksInFlightValidHeaders == 1 && pindex != nullptr) {
nPeersWithValidatedDownloads++;
}
itInFlight = mapBlocksInFlight.insert(std::make_pair(hash, std::make_pair(nodeid, it))).first;
if (pit)
*pit = &itInFlight->second.second;
return true;
}
/** Check whether the last unknown block a peer advertised is not yet known. */
static void ProcessBlockAvailability(NodeId nodeid) EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
CNodeState *state = State(nodeid);
assert(state != nullptr);
if (!state->hashLastUnknownBlock.IsNull()) {
const CBlockIndex* pindex = LookupBlockIndex(state->hashLastUnknownBlock);
if (pindex && pindex->nChainWork > 0) {
if (state->pindexBestKnownBlock == nullptr || pindex->nChainWork >= state->pindexBestKnownBlock->nChainWork) {
state->pindexBestKnownBlock = pindex;
}
state->hashLastUnknownBlock.SetNull();
}
}
}
/** Update tracking information about which blocks a peer is assumed to have. */
static void UpdateBlockAvailability(NodeId nodeid, const uint256 &hash) EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
CNodeState *state = State(nodeid);
assert(state != nullptr);
ProcessBlockAvailability(nodeid);
const CBlockIndex* pindex = LookupBlockIndex(hash);
if (pindex && pindex->nChainWork > 0) {
// An actually better block was announced.
if (state->pindexBestKnownBlock == nullptr || pindex->nChainWork >= state->pindexBestKnownBlock->nChainWork) {
state->pindexBestKnownBlock = pindex;
}
} else {
// An unknown block was announced; just assume that the latest one is the best one.
state->hashLastUnknownBlock = hash;
}
}
/**
* When a peer sends us a valid block, instruct it to announce blocks to us
* using CMPCTBLOCK if possible by adding its nodeid to the end of
* lNodesAnnouncingHeaderAndIDs, and keeping that list under a certain size by
* removing the first element if necessary.
*/
static void MaybeSetPeerAsAnnouncingHeaderAndIDs(NodeId nodeid, CConnman* connman) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
{
AssertLockHeld(cs_main);
CNodeState* nodestate = State(nodeid);
if (!nodestate || !nodestate->fSupportsDesiredCmpctVersion) {
// Never ask from peers who can't provide witnesses.
return;
}
if (nodestate->fProvidesHeaderAndIDs) {
for (std::list<NodeId>::iterator it = lNodesAnnouncingHeaderAndIDs.begin(); it != lNodesAnnouncingHeaderAndIDs.end(); it++) {
if (*it == nodeid) {
lNodesAnnouncingHeaderAndIDs.erase(it);
lNodesAnnouncingHeaderAndIDs.push_back(nodeid);
return;
}
}
connman->ForNode(nodeid, [connman](CNode* pfrom){
AssertLockHeld(cs_main);
uint64_t nCMPCTBLOCKVersion = (pfrom->GetLocalServices() & NODE_WITNESS) ? 2 : 1;
if (lNodesAnnouncingHeaderAndIDs.size() >= 3) {
// As per BIP152, we only get 3 of our peers to announce
// blocks using compact encodings.
connman->ForNode(lNodesAnnouncingHeaderAndIDs.front(), [connman, nCMPCTBLOCKVersion](CNode* pnodeStop){
AssertLockHeld(cs_main);
connman->PushMessage(pnodeStop, CNetMsgMaker(pnodeStop->GetSendVersion()).Make(NetMsgType::SENDCMPCT, /*fAnnounceUsingCMPCTBLOCK=*/false, nCMPCTBLOCKVersion));
return true;
});
lNodesAnnouncingHeaderAndIDs.pop_front();
}
connman->PushMessage(pfrom, CNetMsgMaker(pfrom->GetSendVersion()).Make(NetMsgType::SENDCMPCT, /*fAnnounceUsingCMPCTBLOCK=*/true, nCMPCTBLOCKVersion));
lNodesAnnouncingHeaderAndIDs.push_back(pfrom->GetId());
return true;
});
}
}
static bool TipMayBeStale(const Consensus::Params &consensusParams) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
{
AssertLockHeld(cs_main);
if (g_last_tip_update == 0) {
g_last_tip_update = GetTime();
}
return g_last_tip_update < GetTime() - consensusParams.nPowTargetSpacing * 3 && mapBlocksInFlight.empty();
}
static bool CanDirectFetch(const Consensus::Params &consensusParams) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
{
return ::ChainActive().Tip()->GetBlockTime() > GetAdjustedTime() - consensusParams.nPowTargetSpacing * 20;
}
static bool PeerHasHeader(CNodeState *state, const CBlockIndex *pindex) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
{
if (state->pindexBestKnownBlock && pindex == state->pindexBestKnownBlock->GetAncestor(pindex->nHeight))
return true;
if (state->pindexBestHeaderSent && pindex == state->pindexBestHeaderSent->GetAncestor(pindex->nHeight))
return true;
return false;
}
/** Update pindexLastCommonBlock and add not-in-flight missing successors to vBlocks, until it has
* at most count entries. */
static void FindNextBlocksToDownload(NodeId nodeid, unsigned int count, std::vector<const CBlockIndex*>& vBlocks, NodeId& nodeStaller, const Consensus::Params& consensusParams) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
{
if (count == 0)
return;
vBlocks.reserve(vBlocks.size() + count);
CNodeState *state = State(nodeid);
assert(state != nullptr);
// Make sure pindexBestKnownBlock is up to date, we'll need it.
ProcessBlockAvailability(nodeid);
if (state->pindexBestKnownBlock == nullptr || state->pindexBestKnownBlock->nChainWork < ::ChainActive().Tip()->nChainWork || state->pindexBestKnownBlock->nChainWork < nMinimumChainWork) {
// This peer has nothing interesting.
return;
}
if (state->pindexLastCommonBlock == nullptr) {
// Bootstrap quickly by guessing a parent of our best tip is the forking point.
// Guessing wrong in either direction is not a problem.
state->pindexLastCommonBlock = ::ChainActive()[std::min(state->pindexBestKnownBlock->nHeight, ::ChainActive().Height())];
}
// If the peer reorganized, our previous pindexLastCommonBlock may not be an ancestor
// of its current tip anymore. Go back enough to fix that.
state->pindexLastCommonBlock = LastCommonAncestor(state->pindexLastCommonBlock, state->pindexBestKnownBlock);
if (state->pindexLastCommonBlock == state->pindexBestKnownBlock)
return;
std::vector<const CBlockIndex*> vToFetch;
const CBlockIndex *pindexWalk = state->pindexLastCommonBlock;
// Never fetch further than the best block we know the peer has, or more than BLOCK_DOWNLOAD_WINDOW + 1 beyond the last
// linked block we have in common with this peer. The +1 is so we can detect stalling, namely if we would be able to
// download that next block if the window were 1 larger.
int nWindowEnd = state->pindexLastCommonBlock->nHeight + BLOCK_DOWNLOAD_WINDOW;
int nMaxHeight = std::min<int>(state->pindexBestKnownBlock->nHeight, nWindowEnd + 1);
NodeId waitingfor = -1;
while (pindexWalk->nHeight < nMaxHeight) {
// Read up to 128 (or more, if more blocks than that are needed) successors of pindexWalk (towards
// pindexBestKnownBlock) into vToFetch. We fetch 128, because CBlockIndex::GetAncestor may be as expensive
// as iterating over ~100 CBlockIndex* entries anyway.
int nToFetch = std::min(nMaxHeight - pindexWalk->nHeight, std::max<int>(count - vBlocks.size(), 128));
vToFetch.resize(nToFetch);
pindexWalk = state->pindexBestKnownBlock->GetAncestor(pindexWalk->nHeight + nToFetch);
vToFetch[nToFetch - 1] = pindexWalk;
for (unsigned int i = nToFetch - 1; i > 0; i--) {
vToFetch[i - 1] = vToFetch[i]->pprev;
}
// Iterate over those blocks in vToFetch (in forward direction), adding the ones that
// are not yet downloaded and not in flight to vBlocks. In the meantime, update
// pindexLastCommonBlock as long as all ancestors are already downloaded, or if it's
// already part of our chain (and therefore don't need it even if pruned).
for (const CBlockIndex* pindex : vToFetch) {
if (!pindex->IsValid(BLOCK_VALID_TREE)) {
// We consider the chain that this peer is on invalid.
return;
}
if (!State(nodeid)->fHaveWitness && IsWitnessEnabled(pindex->pprev, consensusParams)) {
// We wouldn't download this block or its descendants from this peer.
return;
}
if (pindex->nStatus & BLOCK_HAVE_DATA || ::ChainActive().Contains(pindex)) {
if (pindex->HaveTxsDownloaded())
state->pindexLastCommonBlock = pindex;
} else if (mapBlocksInFlight.count(pindex->GetBlockHash()) == 0) {
// The block is not already downloaded, and not yet in flight.
if (pindex->nHeight > nWindowEnd) {
// We reached the end of the window.
if (vBlocks.size() == 0 && waitingfor != nodeid) {
// We aren't able to fetch anything, but we would be if the download window was one larger.
nodeStaller = waitingfor;
}
return;
}
vBlocks.push_back(pindex);
if (vBlocks.size() == count) {
return;
}
} else if (waitingfor == -1) {
// This is the first already-in-flight block.
waitingfor = mapBlocksInFlight[pindex->GetBlockHash()].first;
}
}
}
}
void EraseTxRequest(const uint256& txid) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
{
g_already_asked_for.erase(txid);
}
std::chrono::microseconds GetTxRequestTime(const uint256& txid) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
{
auto it = g_already_asked_for.find(txid);
if (it != g_already_asked_for.end()) {
return it->second;
}
return {};
}
void UpdateTxRequestTime(const uint256& txid, std::chrono::microseconds request_time) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
{
auto it = g_already_asked_for.find(txid);
if (it == g_already_asked_for.end()) {
g_already_asked_for.insert(std::make_pair(txid, request_time));
} else {
g_already_asked_for.update(it, request_time);
}
}
std::chrono::microseconds CalculateTxGetDataTime(const uint256& txid, std::chrono::microseconds current_time, bool use_inbound_delay) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
{
std::chrono::microseconds process_time;
const auto last_request_time = GetTxRequestTime(txid);
// First time requesting this tx
if (last_request_time.count() == 0) {
process_time = current_time;
} else {
// Randomize the delay to avoid biasing some peers over others (such as due to
// fixed ordering of peer processing in ThreadMessageHandler)
process_time = last_request_time + GETDATA_TX_INTERVAL + GetRandMicros(MAX_GETDATA_RANDOM_DELAY);
}
// We delay processing announcements from inbound peers
if (use_inbound_delay) process_time += INBOUND_PEER_TX_DELAY;
return process_time;
}
void RequestTx(CNodeState* state, const uint256& txid, std::chrono::microseconds current_time) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
{
CNodeState::TxDownloadState& peer_download_state = state->m_tx_download;
if (peer_download_state.m_tx_announced.size() >= MAX_PEER_TX_ANNOUNCEMENTS ||
peer_download_state.m_tx_process_time.size() >= MAX_PEER_TX_ANNOUNCEMENTS ||
peer_download_state.m_tx_announced.count(txid)) {
// Too many queued announcements from this peer, or we already have
// this announcement
return;
}
peer_download_state.m_tx_announced.insert(txid);
// Calculate the time to try requesting this transaction. Use
// fPreferredDownload as a proxy for outbound peers.
const auto process_time = CalculateTxGetDataTime(txid, current_time, !state->fPreferredDownload);
peer_download_state.m_tx_process_time.emplace(process_time, txid);
}
} // namespace
// This function is used for testing the stale tip eviction logic, see
// denialofservice_tests.cpp
void UpdateLastBlockAnnounceTime(NodeId node, int64_t time_in_seconds)
{
LOCK(cs_main);
CNodeState *state = State(node);
if (state) state->m_last_block_announcement = time_in_seconds;
}
// Returns true for outbound peers, excluding manual connections, feelers, and
// one-shots.
static bool IsOutboundDisconnectionCandidate(const CNode *node)
{
return !(node->fInbound || node->m_manual_connection || node->fFeeler || node->fOneShot);
}
void PeerLogicValidation::InitializeNode(CNode *pnode) {
CAddress addr = pnode->addr;
std::string addrName = pnode->GetAddrName();
NodeId nodeid = pnode->GetId();
{
LOCK(cs_main);
mapNodeState.emplace_hint(mapNodeState.end(), std::piecewise_construct, std::forward_as_tuple(nodeid), std::forward_as_tuple(addr, std::move(addrName), pnode->fInbound, pnode->m_manual_connection));
}
if(!pnode->fInbound)
PushNodeVersion(pnode, connman, GetTime());
}
void PeerLogicValidation::FinalizeNode(NodeId nodeid, bool& fUpdateConnectionTime) {
fUpdateConnectionTime = false;
LOCK(cs_main);
CNodeState *state = State(nodeid);
assert(state != nullptr);
if (state->fSyncStarted)
nSyncStarted--;
if (state->nMisbehavior == 0 && state->fCurrentlyConnected) {
fUpdateConnectionTime = true;
}
for (const QueuedBlock& entry : state->vBlocksInFlight) {
mapBlocksInFlight.erase(entry.hash);
}
EraseOrphansFor(nodeid);
nPreferredDownload -= state->fPreferredDownload;
nPeersWithValidatedDownloads -= (state->nBlocksInFlightValidHeaders != 0);
assert(nPeersWithValidatedDownloads >= 0);
g_outbound_peers_with_protect_from_disconnect -= state->m_chain_sync.m_protect;
assert(g_outbound_peers_with_protect_from_disconnect >= 0);
mapNodeState.erase(nodeid);
if (mapNodeState.empty()) {
// Do a consistency check after the last peer is removed.
assert(mapBlocksInFlight.empty());
assert(nPreferredDownload == 0);
assert(nPeersWithValidatedDownloads == 0);
assert(g_outbound_peers_with_protect_from_disconnect == 0);
}
LogPrint(BCLog::NET, "Cleared nodestate for peer=%d\n", nodeid);
}
bool GetNodeStateStats(NodeId nodeid, CNodeStateStats &stats) {
LOCK(cs_main);
CNodeState *state = State(nodeid);
if (state == nullptr)
return false;
stats.nMisbehavior = state->nMisbehavior;
stats.nSyncHeight = state->pindexBestKnownBlock ? state->pindexBestKnownBlock->nHeight : -1;
stats.nCommonHeight = state->pindexLastCommonBlock ? state->pindexLastCommonBlock->nHeight : -1;
for (const QueuedBlock& queue : state->vBlocksInFlight) {
if (queue.pindex)
stats.vHeightInFlight.push_back(queue.pindex->nHeight);
}
return true;
}
//////////////////////////////////////////////////////////////////////////////
//
// mapOrphanTransactions
//
static void AddToCompactExtraTransactions(const CTransactionRef& tx) EXCLUSIVE_LOCKS_REQUIRED(g_cs_orphans)
{
size_t max_extra_txn = gArgs.GetArg("-blockreconstructionextratxn", DEFAULT_BLOCK_RECONSTRUCTION_EXTRA_TXN);
if (max_extra_txn <= 0)
return;
if (!vExtraTxnForCompact.size())
vExtraTxnForCompact.resize(max_extra_txn);
vExtraTxnForCompact[vExtraTxnForCompactIt] = std::make_pair(tx->GetWitnessHash(), tx);
vExtraTxnForCompactIt = (vExtraTxnForCompactIt + 1) % max_extra_txn;
}
bool AddOrphanTx(const CTransactionRef& tx, NodeId peer) EXCLUSIVE_LOCKS_REQUIRED(g_cs_orphans)
{
const uint256& hash = tx->GetHash();
if (mapOrphanTransactions.count(hash))
return false;
// Ignore big transactions, to avoid a
// send-big-orphans memory exhaustion attack. If a peer has a legitimate
// large transaction with a missing parent then we assume
// it will rebroadcast it later, after the parent transaction(s)
// have been mined or received.
// 100 orphans, each of which is at most 100,000 bytes big is
// at most 10 megabytes of orphans and somewhat more byprev index (in the worst case):
unsigned int sz = GetTransactionWeight(*tx);
if (sz > MAX_STANDARD_TX_WEIGHT)
{
LogPrint(BCLog::MEMPOOL, "ignoring large orphan tx (size: %u, hash: %s)\n", sz, hash.ToString());
return false;
}
auto ret = mapOrphanTransactions.emplace(hash, COrphanTx{tx, peer, GetTime() + ORPHAN_TX_EXPIRE_TIME, g_orphan_list.size()});
assert(ret.second);
g_orphan_list.push_back(ret.first);
for (const CTxIn& txin : tx->vin) {
mapOrphanTransactionsByPrev[txin.prevout].insert(ret.first);
}
AddToCompactExtraTransactions(tx);
LogPrint(BCLog::MEMPOOL, "stored orphan tx %s (mapsz %u outsz %u)\n", hash.ToString(),
mapOrphanTransactions.size(), mapOrphanTransactionsByPrev.size());
return true;
}
int static EraseOrphanTx(uint256 hash) EXCLUSIVE_LOCKS_REQUIRED(g_cs_orphans)
{
std::map<uint256, COrphanTx>::iterator it = mapOrphanTransactions.find(hash);
if (it == mapOrphanTransactions.end())
return 0;
for (const CTxIn& txin : it->second.tx->vin)
{
auto itPrev = mapOrphanTransactionsByPrev.find(txin.prevout);
if (itPrev == mapOrphanTransactionsByPrev.end())
continue;
itPrev->second.erase(it);
if (itPrev->second.empty())
mapOrphanTransactionsByPrev.erase(itPrev);
}
size_t old_pos = it->second.list_pos;
assert(g_orphan_list[old_pos] == it);
if (old_pos + 1 != g_orphan_list.size()) {
// Unless we're deleting the last entry in g_orphan_list, move the last
// entry to the position we're deleting.
auto it_last = g_orphan_list.back();
g_orphan_list[old_pos] = it_last;
it_last->second.list_pos = old_pos;
}
g_orphan_list.pop_back();
mapOrphanTransactions.erase(it);
return 1;
}
void EraseOrphansFor(NodeId peer)
{
LOCK(g_cs_orphans);
int nErased = 0;
std::map<uint256, COrphanTx>::iterator iter = mapOrphanTransactions.begin();
while (iter != mapOrphanTransactions.end())
{
std::map<uint256, COrphanTx>::iterator maybeErase = iter++; // increment to avoid iterator becoming invalid
if (maybeErase->second.fromPeer == peer)
{
nErased += EraseOrphanTx(maybeErase->second.tx->GetHash());
}
}
if (nErased > 0) LogPrint(BCLog::MEMPOOL, "Erased %d orphan tx from peer=%d\n", nErased, peer);
}
unsigned int LimitOrphanTxSize(unsigned int nMaxOrphans)
{
LOCK(g_cs_orphans);
unsigned int nEvicted = 0;
static int64_t nNextSweep;
int64_t nNow = GetTime();
if (nNextSweep <= nNow) {
// Sweep out expired orphan pool entries:
int nErased = 0;
int64_t nMinExpTime = nNow + ORPHAN_TX_EXPIRE_TIME - ORPHAN_TX_EXPIRE_INTERVAL;
std::map<uint256, COrphanTx>::iterator iter = mapOrphanTransactions.begin();
while (iter != mapOrphanTransactions.end())
{
std::map<uint256, COrphanTx>::iterator maybeErase = iter++;
if (maybeErase->second.nTimeExpire <= nNow) {
nErased += EraseOrphanTx(maybeErase->second.tx->GetHash());
} else {
nMinExpTime = std::min(maybeErase->second.nTimeExpire, nMinExpTime);
}
}
// Sweep again 5 minutes after the next entry that expires in order to batch the linear scan.
nNextSweep = nMinExpTime + ORPHAN_TX_EXPIRE_INTERVAL;
if (nErased > 0) LogPrint(BCLog::MEMPOOL, "Erased %d orphan tx due to expiration\n", nErased);
}
FastRandomContext rng;
while (mapOrphanTransactions.size() > nMaxOrphans)
{
// Evict a random orphan:
size_t randompos = rng.randrange(g_orphan_list.size());
EraseOrphanTx(g_orphan_list[randompos]->first);
++nEvicted;
}
return nEvicted;
}
/**
* Mark a misbehaving peer to be banned depending upon the value of `-banscore`.
*/
void Misbehaving(NodeId pnode, int howmuch, const std::string& message) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
{
if (howmuch == 0)
return;
CNodeState *state = State(pnode);
if (state == nullptr)
return;
state->nMisbehavior += howmuch;
int banscore = gArgs.GetArg("-banscore", DEFAULT_BANSCORE_THRESHOLD);
std::string message_prefixed = message.empty() ? "" : (": " + message);
if (state->nMisbehavior >= banscore && state->nMisbehavior - howmuch < banscore)
{
LogPrint(BCLog::NET, "%s: %s peer=%d (%d -> %d) BAN THRESHOLD EXCEEDED%s\n", __func__, state->name, pnode, state->nMisbehavior-howmuch, state->nMisbehavior, message_prefixed);
state->fShouldBan = true;
} else
LogPrint(BCLog::NET, "%s: %s peer=%d (%d -> %d)%s\n", __func__, state->name, pnode, state->nMisbehavior-howmuch, state->nMisbehavior, message_prefixed);
}
/**
* Potentially ban a node based on the contents of a BlockValidationState object
*
* @param[in] via_compact_block this bool is passed in because net_processing should
* punish peers differently depending on whether the data was provided in a compact
* block message or not. If the compact block had a valid header, but contained invalid
* txs, the peer should not be punished. See BIP 152.
*
* @return Returns true if the peer was punished (probably disconnected)
*/
static bool MaybePunishNodeForBlock(NodeId nodeid, const BlockValidationState& state, bool via_compact_block, const std::string& message = "") {
switch (state.GetResult()) {
case BlockValidationResult::BLOCK_RESULT_UNSET:
break;
// The node is providing invalid data:
case BlockValidationResult::BLOCK_CONSENSUS:
case BlockValidationResult::BLOCK_MUTATED:
if (!via_compact_block) {
LOCK(cs_main);
Misbehaving(nodeid, 100, message);
return true;
}
break;
case BlockValidationResult::BLOCK_CACHED_INVALID:
{
LOCK(cs_main);
CNodeState *node_state = State(nodeid);
if (node_state == nullptr) {
break;
}
// Ban outbound (but not inbound) peers if on an invalid chain.
// Exempt HB compact block peers and manual connections.
if (!via_compact_block && !node_state->m_is_inbound && !node_state->m_is_manual_connection) {
Misbehaving(nodeid, 100, message);
return true;
}
break;
}
case BlockValidationResult::BLOCK_INVALID_HEADER:
case BlockValidationResult::BLOCK_CHECKPOINT:
case BlockValidationResult::BLOCK_INVALID_PREV:
{
LOCK(cs_main);
Misbehaving(nodeid, 100, message);
}
return true;
// Conflicting (but not necessarily invalid) data or different policy:
case BlockValidationResult::BLOCK_MISSING_PREV:
{
// TODO: Handle this much more gracefully (10 DoS points is super arbitrary)
LOCK(cs_main);
Misbehaving(nodeid, 10, message);
}
return true;
case BlockValidationResult::BLOCK_RECENT_CONSENSUS_CHANGE:
case BlockValidationResult::BLOCK_TIME_FUTURE:
break;
}
if (message != "") {
LogPrint(BCLog::NET, "peer=%d: %s\n", nodeid, message);
}
return false;
}
/**
* Potentially ban a node based on the contents of a TxValidationState object
*
* @return Returns true if the peer was punished (probably disconnected)
*/
static bool MaybePunishNodeForTx(NodeId nodeid, const TxValidationState& state, const std::string& message = "")
{
switch (state.GetResult()) {
case TxValidationResult::TX_RESULT_UNSET:
break;
// The node is providing invalid data:
case TxValidationResult::TX_CONSENSUS:
{
LOCK(cs_main);
Misbehaving(nodeid, 100, message);
return true;
}
// Conflicting (but not necessarily invalid) data or different policy:
case TxValidationResult::TX_RECENT_CONSENSUS_CHANGE:
case TxValidationResult::TX_NOT_STANDARD:
case TxValidationResult::TX_MISSING_INPUTS:
case TxValidationResult::TX_PREMATURE_SPEND:
case TxValidationResult::TX_WITNESS_MUTATED:
case TxValidationResult::TX_CONFLICT:
case TxValidationResult::TX_MEMPOOL_POLICY:
break;
}
if (message != "") {
LogPrint(BCLog::NET, "peer=%d: %s\n", nodeid, message);
}
return false;
}
//////////////////////////////////////////////////////////////////////////////
//
// blockchain -> download logic notification
//
// To prevent fingerprinting attacks, only send blocks/headers outside of the
// active chain if they are no more than a month older (both in time, and in
// best equivalent proof of work) than the best header chain we know about and
// we fully-validated them at some point.
static bool BlockRequestAllowed(const CBlockIndex* pindex, const Consensus::Params& consensusParams) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
{
AssertLockHeld(cs_main);
if (::ChainActive().Contains(pindex)) return true;
return pindex->IsValid(BLOCK_VALID_SCRIPTS) && (pindexBestHeader != nullptr) &&
(pindexBestHeader->GetBlockTime() - pindex->GetBlockTime() < STALE_RELAY_AGE_LIMIT) &&
(GetBlockProofEquivalentTime(*pindexBestHeader, *pindex, *pindexBestHeader, consensusParams) < STALE_RELAY_AGE_LIMIT);
}
PeerLogicValidation::PeerLogicValidation(CConnman* connmanIn, BanMan* banman, CScheduler& scheduler, CTxMemPool& pool)
: connman(connmanIn),
m_banman(banman),
m_mempool(pool),
m_stale_tip_check_time(0)
{
// Initialize global variables that cannot be constructed at startup.
recentRejects.reset(new CRollingBloomFilter(120000, 0.000001));
// Blocks don't typically have more than 4000 transactions, so this should
// be at least six blocks (~1 hr) worth of transactions that we can store.
// If the number of transactions appearing in a block goes up, or if we are
// seeing getdata requests more than an hour after initial announcement, we
// can increase this number.
// The false positive rate of 1/1M should come out to less than 1
// transaction per day that would be inadvertently ignored (which is the
// same probability that we have in the reject filter).
g_recent_confirmed_transactions.reset(new CRollingBloomFilter(24000, 0.000001));
const Consensus::Params& consensusParams = Params().GetConsensus();
// Stale tip checking and peer eviction are on two different timers, but we
// don't want them to get out of sync due to drift in the scheduler, so we
// combine them in one function and schedule at the quicker (peer-eviction)
// timer.
static_assert(EXTRA_PEER_CHECK_INTERVAL < STALE_CHECK_INTERVAL, "peer eviction timer should be less than stale tip check timer");
scheduler.scheduleEvery([this, consensusParams] { this->CheckForStaleTipAndEvictPeers(consensusParams); }, std::chrono::seconds{EXTRA_PEER_CHECK_INTERVAL});
}
/**
* Evict orphan txn pool entries (EraseOrphanTx) based on a newly connected
* block. Also save the time of the last tip update.
*/
void PeerLogicValidation::BlockConnected(const std::shared_ptr<const CBlock>& pblock, const CBlockIndex* pindex)
{
{
LOCK(g_cs_orphans);
std::vector<uint256> vOrphanErase;
for (const CTransactionRef& ptx : pblock->vtx) {
const CTransaction& tx = *ptx;
// Which orphan pool entries must we evict?
for (const auto& txin : tx.vin) {
auto itByPrev = mapOrphanTransactionsByPrev.find(txin.prevout);
if (itByPrev == mapOrphanTransactionsByPrev.end()) continue;
for (auto mi = itByPrev->second.begin(); mi != itByPrev->second.end(); ++mi) {
const CTransaction& orphanTx = *(*mi)->second.tx;
const uint256& orphanHash = orphanTx.GetHash();
vOrphanErase.push_back(orphanHash);
}
}
}
// Erase orphan transactions included or precluded by this block
if (vOrphanErase.size()) {
int nErased = 0;
for (const uint256& orphanHash : vOrphanErase) {
nErased += EraseOrphanTx(orphanHash);
}
LogPrint(BCLog::MEMPOOL, "Erased %d orphan tx included or conflicted by block\n", nErased);
}
g_last_tip_update = GetTime();
}
{
LOCK(g_cs_recent_confirmed_transactions);
for (const auto& ptx : pblock->vtx) {
g_recent_confirmed_transactions->insert(ptx->GetHash());
}
}
}
void PeerLogicValidation::BlockDisconnected(const std::shared_ptr<const CBlock> &block, const CBlockIndex* pindex)
{
// To avoid relay problems with transactions that were previously
// confirmed, clear our filter of recently confirmed transactions whenever
// there's a reorg.
// This means that in a 1-block reorg (where 1 block is disconnected and
// then another block reconnected), our filter will drop to having only one
// block's worth of transactions in it, but that should be fine, since
// presumably the most common case of relaying a confirmed transaction
// should be just after a new block containing it is found.
LOCK(g_cs_recent_confirmed_transactions);
g_recent_confirmed_transactions->reset();
}
// All of the following cache a recent block, and are protected by cs_most_recent_block
static RecursiveMutex cs_most_recent_block;
static std::shared_ptr<const CBlock> most_recent_block GUARDED_BY(cs_most_recent_block);
static std::shared_ptr<const CBlockHeaderAndShortTxIDs> most_recent_compact_block GUARDED_BY(cs_most_recent_block);
static uint256 most_recent_block_hash GUARDED_BY(cs_most_recent_block);
static bool fWitnessesPresentInMostRecentCompactBlock GUARDED_BY(cs_most_recent_block);
/**
* Maintain state about the best-seen block and fast-announce a compact block
* to compatible peers.
*/
void PeerLogicValidation::NewPoWValidBlock(const CBlockIndex *pindex, const std::shared_ptr<const CBlock>& pblock) {
std::shared_ptr<const CBlockHeaderAndShortTxIDs> pcmpctblock = std::make_shared<const CBlockHeaderAndShortTxIDs> (*pblock, true);
const CNetMsgMaker msgMaker(PROTOCOL_VERSION);
LOCK(cs_main);
static int nHighestFastAnnounce = 0;
if (pindex->nHeight <= nHighestFastAnnounce)
return;
nHighestFastAnnounce = pindex->nHeight;
bool fWitnessEnabled = IsWitnessEnabled(pindex->pprev, Params().GetConsensus());
uint256 hashBlock(pblock->GetHash());
{
LOCK(cs_most_recent_block);
most_recent_block_hash = hashBlock;
most_recent_block = pblock;
most_recent_compact_block = pcmpctblock;
fWitnessesPresentInMostRecentCompactBlock = fWitnessEnabled;
}
connman->ForEachNode([this, &pcmpctblock, pindex, &msgMaker, fWitnessEnabled, &hashBlock](CNode* pnode) {
AssertLockHeld(cs_main);
// TODO: Avoid the repeated-serialization here
if (pnode->nVersion < INVALID_CB_NO_BAN_VERSION || pnode->fDisconnect)
return;
ProcessBlockAvailability(pnode->GetId());
CNodeState &state = *State(pnode->GetId());
// If the peer has, or we announced to them the previous block already,
// but we don't think they have this one, go ahead and announce it
if (state.fPreferHeaderAndIDs && (!fWitnessEnabled || state.fWantsCmpctWitness) &&
!PeerHasHeader(&state, pindex) && PeerHasHeader(&state, pindex->pprev)) {
LogPrint(BCLog::NET, "%s sending header-and-ids %s to peer=%d\n", "PeerLogicValidation::NewPoWValidBlock",
hashBlock.ToString(), pnode->GetId());
connman->PushMessage(pnode, msgMaker.Make(NetMsgType::CMPCTBLOCK, *pcmpctblock));
state.pindexBestHeaderSent = pindex;
}
});
}
/**
* Update our best height and announce any block hashes which weren't previously
* in ::ChainActive() to our peers.
*/
void PeerLogicValidation::UpdatedBlockTip(const CBlockIndex *pindexNew, const CBlockIndex *pindexFork, bool fInitialDownload) {
const int nNewHeight = pindexNew->nHeight;
connman->SetBestHeight(nNewHeight);
SetServiceFlagsIBDCache(!fInitialDownload);
if (!fInitialDownload) {
// Find the hashes of all blocks that weren't previously in the best chain.
std::vector<uint256> vHashes;
const CBlockIndex *pindexToAnnounce = pindexNew;
while (pindexToAnnounce != pindexFork) {
vHashes.push_back(pindexToAnnounce->GetBlockHash());
pindexToAnnounce = pindexToAnnounce->pprev;
if (vHashes.size() == MAX_BLOCKS_TO_ANNOUNCE) {
// Limit announcements in case of a huge reorganization.
// Rely on the peer's synchronization mechanism in that case.
break;
}
}
// Relay inventory, but don't relay old inventory during initial block download.
connman->ForEachNode([nNewHeight, &vHashes](CNode* pnode) {
if (nNewHeight > (pnode->nStartingHeight != -1 ? pnode->nStartingHeight - 2000 : 0)) {
for (const uint256& hash : reverse_iterate(vHashes)) {
pnode->PushBlockHash(hash);
}
}
});
connman->WakeMessageHandler();
}
}
/**
* Handle invalid block rejection and consequent peer banning, maintain which
* peers announce compact blocks.
*/
void PeerLogicValidation::BlockChecked(const CBlock& block, const BlockValidationState& state) {
LOCK(cs_main);
const uint256 hash(block.GetHash());
std::map<uint256, std::pair<NodeId, bool>>::iterator it = mapBlockSource.find(hash);
// If the block failed validation, we know where it came from and we're still connected
// to that peer, maybe punish.
if (state.IsInvalid() &&
it != mapBlockSource.end() &&
State(it->second.first)) {
MaybePunishNodeForBlock(/*nodeid=*/ it->second.first, state, /*via_compact_block=*/ !it->second.second);
}
// Check that:
// 1. The block is valid
// 2. We're not in initial block download
// 3. This is currently the best block we're aware of. We haven't updated
// the tip yet so we have no way to check this directly here. Instead we
// just check that there are currently no other blocks in flight.
else if (state.IsValid() &&
!::ChainstateActive().IsInitialBlockDownload() &&
mapBlocksInFlight.count(hash) == mapBlocksInFlight.size()) {
if (it != mapBlockSource.end()) {
MaybeSetPeerAsAnnouncingHeaderAndIDs(it->second.first, connman);
}
}
if (it != mapBlockSource.end())
mapBlockSource.erase(it);
}
//////////////////////////////////////////////////////////////////////////////
//
// Messages
//
bool static AlreadyHave(const CInv& inv, const CTxMemPool& mempool) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
{
switch (inv.type)
{
case MSG_TX:
case MSG_WITNESS_TX:
{
assert(recentRejects);
if (::ChainActive().Tip()->GetBlockHash() != hashRecentRejectsChainTip)
{
// If the chain tip has changed previously rejected transactions
// might be now valid, e.g. due to a nLockTime'd tx becoming valid,
// or a double-spend. Reset the rejects filter and give those
// txs a second chance.
hashRecentRejectsChainTip = ::ChainActive().Tip()->GetBlockHash();
recentRejects->reset();
}
{
LOCK(g_cs_orphans);
if (mapOrphanTransactions.count(inv.hash)) return true;
}
{
LOCK(g_cs_recent_confirmed_transactions);
if (g_recent_confirmed_transactions->contains(inv.hash)) return true;
}
return recentRejects->contains(inv.hash) ||
mempool.exists(inv.hash);
}
case MSG_BLOCK:
case MSG_WITNESS_BLOCK:
return LookupBlockIndex(inv.hash) != nullptr;
}
// Don't know what it is, just say we already got one
return true;
}
void RelayTransaction(const uint256& txid, const CConnman& connman)
{
CInv inv(MSG_TX, txid);
connman.ForEachNode([&inv](CNode* pnode)
{
pnode->PushInventory(inv);
});
}
static void RelayAddress(const CAddress& addr, bool fReachable, CConnman* connman)
{
unsigned int nRelayNodes = fReachable ? 2 : 1; // limited relaying of addresses outside our network(s)
// Relay to a limited number of other nodes
// Use deterministic randomness to send to the same nodes for 24 hours
// at a time so the m_addr_knowns of the chosen nodes prevent repeats
uint64_t hashAddr = addr.GetHash();
const CSipHasher hasher = connman->GetDeterministicRandomizer(RANDOMIZER_ID_ADDRESS_RELAY).Write(hashAddr << 32).Write((GetTime() + hashAddr) / (24*60*60));
FastRandomContext insecure_rand;
std::array<std::pair<uint64_t, CNode*>,2> best{{{0, nullptr}, {0, nullptr}}};
assert(nRelayNodes <= best.size());
auto sortfunc = [&best, &hasher, nRelayNodes](CNode* pnode) {
if (pnode->nVersion >= CADDR_TIME_VERSION && pnode->IsAddrRelayPeer()) {
uint64_t hashKey = CSipHasher(hasher).Write(pnode->GetId()).Finalize();
for (unsigned int i = 0; i < nRelayNodes; i++) {
if (hashKey > best[i].first) {
std::copy(best.begin() + i, best.begin() + nRelayNodes - 1, best.begin() + i + 1);
best[i] = std::make_pair(hashKey, pnode);
break;
}
}
}
};
auto pushfunc = [&addr, &best, nRelayNodes, &insecure_rand] {
for (unsigned int i = 0; i < nRelayNodes && best[i].first != 0; i++) {
best[i].second->PushAddress(addr, insecure_rand);
}
};
connman->ForEachNodeThen(std::move(sortfunc), std::move(pushfunc));
}
void static ProcessGetBlockData(CNode* pfrom, const CChainParams& chainparams, const CInv& inv, CConnman* connman)
{
bool send = false;
std::shared_ptr<const CBlock> a_recent_block;
std::shared_ptr<const CBlockHeaderAndShortTxIDs> a_recent_compact_block;
bool fWitnessesPresentInARecentCompactBlock;
const Consensus::Params& consensusParams = chainparams.GetConsensus();
{
LOCK(cs_most_recent_block);
a_recent_block = most_recent_block;
a_recent_compact_block = most_recent_compact_block;
fWitnessesPresentInARecentCompactBlock = fWitnessesPresentInMostRecentCompactBlock;
}
bool need_activate_chain = false;
{
LOCK(cs_main);
const CBlockIndex* pindex = LookupBlockIndex(inv.hash);
if (pindex) {
if (pindex->HaveTxsDownloaded() && !pindex->IsValid(BLOCK_VALID_SCRIPTS) &&
pindex->IsValid(BLOCK_VALID_TREE)) {
// If we have the block and all of its parents, but have not yet validated it,
// we might be in the middle of connecting it (ie in the unlock of cs_main
// before ActivateBestChain but after AcceptBlock).
// In this case, we need to run ActivateBestChain prior to checking the relay
// conditions below.
need_activate_chain = true;
}
}
} // release cs_main before calling ActivateBestChain
if (need_activate_chain) {
BlockValidationState state;
if (!ActivateBestChain(state, Params(), a_recent_block)) {
LogPrint(BCLog::NET, "failed to activate chain (%s)\n", state.ToString());
}
}
LOCK(cs_main);
const CBlockIndex* pindex = LookupBlockIndex(inv.hash);
if (pindex) {
send = BlockRequestAllowed(pindex, consensusParams);
if (!send) {
LogPrint(BCLog::NET, "%s: ignoring request from peer=%i for old block that isn't in the main chain\n", __func__, pfrom->GetId());
}
}
const CNetMsgMaker msgMaker(pfrom->GetSendVersion());
// disconnect node in case we have reached the outbound limit for serving historical blocks
// never disconnect whitelisted nodes
if (send && connman->OutboundTargetReached(true) && ( ((pindexBestHeader != nullptr) && (pindexBestHeader->GetBlockTime() - pindex->GetBlockTime() > HISTORICAL_BLOCK_AGE)) || inv.type == MSG_FILTERED_BLOCK) && !pfrom->HasPermission(PF_NOBAN))
{
LogPrint(BCLog::NET, "historical block serving limit reached, disconnect peer=%d\n", pfrom->GetId());
//disconnect node
pfrom->fDisconnect = true;
send = false;
}
// Avoid leaking prune-height by never sending blocks below the NODE_NETWORK_LIMITED threshold
if (send && !pfrom->HasPermission(PF_NOBAN) && (
(((pfrom->GetLocalServices() & NODE_NETWORK_LIMITED) == NODE_NETWORK_LIMITED) && ((pfrom->GetLocalServices() & NODE_NETWORK) != NODE_NETWORK) && (::ChainActive().Tip()->nHeight - pindex->nHeight > (int)NODE_NETWORK_LIMITED_MIN_BLOCKS + 2 /* add two blocks buffer extension for possible races */) )
)) {
LogPrint(BCLog::NET, "Ignore block request below NODE_NETWORK_LIMITED threshold from peer=%d\n", pfrom->GetId());
//disconnect node and prevent it from stalling (would otherwise wait for the missing block)
pfrom->fDisconnect = true;
send = false;
}
// Pruned nodes may have deleted the block, so check whether
// it's available before trying to send.
if (send && (pindex->nStatus & BLOCK_HAVE_DATA))
{
std::shared_ptr<const CBlock> pblock;
if (a_recent_block && a_recent_block->GetHash() == pindex->GetBlockHash()) {
pblock = a_recent_block;
} else if (inv.type == MSG_WITNESS_BLOCK) {
// Fast-path: in this case it is possible to serve the block directly from disk,
// as the network format matches the format on disk
std::vector<uint8_t> block_data;
if (!ReadRawBlockFromDisk(block_data, pindex, chainparams.MessageStart())) {
assert(!"cannot load block from disk");
}
connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::BLOCK, MakeSpan(block_data)));
// Don't set pblock as we've sent the block
} else {
// Send block from disk
std::shared_ptr<CBlock> pblockRead = std::make_shared<CBlock>();
if (!ReadBlockFromDisk(*pblockRead, pindex, consensusParams))
assert(!"cannot load block from disk");
pblock = pblockRead;
}
if (pblock) {
if (inv.type == MSG_BLOCK)
connman->PushMessage(pfrom, msgMaker.Make(SERIALIZE_TRANSACTION_NO_WITNESS, NetMsgType::BLOCK, *pblock));
else if (inv.type == MSG_WITNESS_BLOCK)
connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::BLOCK, *pblock));
else if (inv.type == MSG_FILTERED_BLOCK)
{
bool sendMerkleBlock = false;
CMerkleBlock merkleBlock;
if (pfrom->m_tx_relay != nullptr) {
LOCK(pfrom->m_tx_relay->cs_filter);
if (pfrom->m_tx_relay->pfilter) {
sendMerkleBlock = true;
merkleBlock = CMerkleBlock(*pblock, *pfrom->m_tx_relay->pfilter);
}
}
if (sendMerkleBlock) {
connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::MERKLEBLOCK, merkleBlock));
// CMerkleBlock just contains hashes, so also push any transactions in the block the client did not see
// This avoids hurting performance by pointlessly requiring a round-trip
// Note that there is currently no way for a node to request any single transactions we didn't send here -
// they must either disconnect and retry or request the full block.
// Thus, the protocol spec specified allows for us to provide duplicate txn here,
// however we MUST always provide at least what the remote peer needs
typedef std::pair<unsigned int, uint256> PairType;
for (PairType& pair : merkleBlock.vMatchedTxn)
connman->PushMessage(pfrom, msgMaker.Make(SERIALIZE_TRANSACTION_NO_WITNESS, NetMsgType::TX, *pblock->vtx[pair.first]));
}
// else
// no response
}
else if (inv.type == MSG_CMPCT_BLOCK)
{
// If a peer is asking for old blocks, we're almost guaranteed
// they won't have a useful mempool to match against a compact block,
// and we don't feel like constructing the object for them, so
// instead we respond with the full, non-compact block.
bool fPeerWantsWitness = State(pfrom->GetId())->fWantsCmpctWitness;
int nSendFlags = fPeerWantsWitness ? 0 : SERIALIZE_TRANSACTION_NO_WITNESS;
if (CanDirectFetch(consensusParams) && pindex->nHeight >= ::ChainActive().Height() - MAX_CMPCTBLOCK_DEPTH) {
if ((fPeerWantsWitness || !fWitnessesPresentInARecentCompactBlock) && a_recent_compact_block && a_recent_compact_block->header.GetHash() == pindex->GetBlockHash()) {
connman->PushMessage(pfrom, msgMaker.Make(nSendFlags, NetMsgType::CMPCTBLOCK, *a_recent_compact_block));
} else {
CBlockHeaderAndShortTxIDs cmpctblock(*pblock, fPeerWantsWitness);
connman->PushMessage(pfrom, msgMaker.Make(nSendFlags, NetMsgType::CMPCTBLOCK, cmpctblock));
}
} else {
connman->PushMessage(pfrom, msgMaker.Make(nSendFlags, NetMsgType::BLOCK, *pblock));
}
}
}
// Trigger the peer node to send a getblocks request for the next batch of inventory
if (inv.hash == pfrom->hashContinue)
{
// Bypass PushInventory, this must send even if redundant,
// and we want it right after the last block so they don't
// wait for other stuff first.
std::vector<CInv> vInv;
vInv.push_back(CInv(MSG_BLOCK, ::ChainActive().Tip()->GetBlockHash()));
connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::INV, vInv));
pfrom->hashContinue.SetNull();
}
}
}
void static ProcessGetData(CNode* pfrom, const CChainParams& chainparams, CConnman* connman, const CTxMemPool& mempool, const std::atomic<bool>& interruptMsgProc) LOCKS_EXCLUDED(cs_main)
{
AssertLockNotHeld(cs_main);
std::deque<CInv>::iterator it = pfrom->vRecvGetData.begin();
std::vector<CInv> vNotFound;
const CNetMsgMaker msgMaker(pfrom->GetSendVersion());
// Note that if we receive a getdata for a MSG_TX or MSG_WITNESS_TX from a
// block-relay-only outbound peer, we will stop processing further getdata
// messages from this peer (likely resulting in our peer eventually
// disconnecting us).
if (pfrom->m_tx_relay != nullptr) {
// mempool entries added before this time have likely expired from mapRelay
const std::chrono::seconds longlived_mempool_time = GetTime<std::chrono::seconds>() - RELAY_TX_CACHE_TIME;
const std::chrono::seconds mempool_req = pfrom->m_tx_relay->m_last_mempool_req.load();
LOCK(cs_main);
while (it != pfrom->vRecvGetData.end() && (it->type == MSG_TX || it->type == MSG_WITNESS_TX)) {
if (interruptMsgProc)
return;
// Don't bother if send buffer is too full to respond anyway
if (pfrom->fPauseSend)
break;
const CInv &inv = *it;
it++;
// Send stream from relay memory
bool push = false;
auto mi = mapRelay.find(inv.hash);
int nSendFlags = (inv.type == MSG_TX ? SERIALIZE_TRANSACTION_NO_WITNESS : 0);
if (mi != mapRelay.end()) {
connman->PushMessage(pfrom, msgMaker.Make(nSendFlags, NetMsgType::TX, *mi->second));
push = true;
} else {
auto txinfo = mempool.info(inv.hash);
// To protect privacy, do not answer getdata using the mempool when
// that TX couldn't have been INVed in reply to a MEMPOOL request,
// or when it's too recent to have expired from mapRelay.
if (txinfo.tx && (
(mempool_req.count() && txinfo.m_time <= mempool_req)
|| (txinfo.m_time <= longlived_mempool_time)))
{
connman->PushMessage(pfrom, msgMaker.Make(nSendFlags, NetMsgType::TX, *txinfo.tx));
push = true;
}
}
if (!push) {
vNotFound.push_back(inv);
}
}
} // release cs_main
if (it != pfrom->vRecvGetData.end() && !pfrom->fPauseSend) {
const CInv &inv = *it;
if (inv.type == MSG_BLOCK || inv.type == MSG_FILTERED_BLOCK || inv.type == MSG_CMPCT_BLOCK || inv.type == MSG_WITNESS_BLOCK) {
it++;
ProcessGetBlockData(pfrom, chainparams, inv, connman);
}
}
// Unknown types in the GetData stay in vRecvGetData and block any future
// message from this peer, see vRecvGetData check in ProcessMessages().
// Depending on future p2p changes, we might either drop unknown getdata on
// the floor or disconnect the peer.
pfrom->vRecvGetData.erase(pfrom->vRecvGetData.begin(), it);
if (!vNotFound.empty()) {
// Let the peer know that we didn't find what it asked for, so it doesn't
// have to wait around forever.
// SPV clients care about this message: it's needed when they are
// recursively walking the dependencies of relevant unconfirmed
// transactions. SPV clients want to do that because they want to know
// about (and store and rebroadcast and risk analyze) the dependencies
// of transactions relevant to them, without having to download the
// entire memory pool.
// Also, other nodes can use these messages to automatically request a
// transaction from some other peer that annnounced it, and stop
// waiting for us to respond.
// In normal operation, we often send NOTFOUND messages for parents of
// transactions that we relay; if a peer is missing a parent, they may
// assume we have them and request the parents from us.
connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::NOTFOUND, vNotFound));
}
}
static uint32_t GetFetchFlags(CNode* pfrom) EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
uint32_t nFetchFlags = 0;
if ((pfrom->GetLocalServices() & NODE_WITNESS) && State(pfrom->GetId())->fHaveWitness) {
nFetchFlags |= MSG_WITNESS_FLAG;
}
return nFetchFlags;
}
inline void static SendBlockTransactions(const CBlock& block, const BlockTransactionsRequest& req, CNode* pfrom, CConnman* connman) {
BlockTransactions resp(req);
for (size_t i = 0; i < req.indexes.size(); i++) {
if (req.indexes[i] >= block.vtx.size()) {
LOCK(cs_main);
Misbehaving(pfrom->GetId(), 100, strprintf("Peer %d sent us a getblocktxn with out-of-bounds tx indices", pfrom->GetId()));
return;
}
resp.txn[i] = block.vtx[req.indexes[i]];
}
LOCK(cs_main);
const CNetMsgMaker msgMaker(pfrom->GetSendVersion());
int nSendFlags = State(pfrom->GetId())->fWantsCmpctWitness ? 0 : SERIALIZE_TRANSACTION_NO_WITNESS;
connman->PushMessage(pfrom, msgMaker.Make(nSendFlags, NetMsgType::BLOCKTXN, resp));
}
bool static ProcessHeadersMessage(CNode* pfrom, CConnman* connman, CTxMemPool& mempool, const std::vector<CBlockHeader>& headers, const CChainParams& chainparams, bool via_compact_block)
{
const CNetMsgMaker msgMaker(pfrom->GetSendVersion());
size_t nCount = headers.size();
if (nCount == 0) {
// Nothing interesting. Stop asking this peers for more headers.
return true;
}
bool received_new_header = false;
const CBlockIndex *pindexLast = nullptr;
{
LOCK(cs_main);
CNodeState *nodestate = State(pfrom->GetId());
// If this looks like it could be a block announcement (nCount <
// MAX_BLOCKS_TO_ANNOUNCE), use special logic for handling headers that
// don't connect:
// - Send a getheaders message in response to try to connect the chain.
// - The peer can send up to MAX_UNCONNECTING_HEADERS in a row that
// don't connect before giving DoS points
// - Once a headers message is received that is valid and does connect,
// nUnconnectingHeaders gets reset back to 0.
if (!LookupBlockIndex(headers[0].hashPrevBlock) && nCount < MAX_BLOCKS_TO_ANNOUNCE) {
nodestate->nUnconnectingHeaders++;
connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::GETHEADERS, ::ChainActive().GetLocator(pindexBestHeader), uint256()));
LogPrint(BCLog::NET, "received header %s: missing prev block %s, sending getheaders (%d) to end (peer=%d, nUnconnectingHeaders=%d)\n",
headers[0].GetHash().ToString(),
headers[0].hashPrevBlock.ToString(),
pindexBestHeader->nHeight,
pfrom->GetId(), nodestate->nUnconnectingHeaders);
// Set hashLastUnknownBlock for this peer, so that if we
// eventually get the headers - even from a different peer -
// we can use this peer to download.
UpdateBlockAvailability(pfrom->GetId(), headers.back().GetHash());
if (nodestate->nUnconnectingHeaders % MAX_UNCONNECTING_HEADERS == 0) {
Misbehaving(pfrom->GetId(), 20);
}
return true;
}
uint256 hashLastBlock;
for (const CBlockHeader& header : headers) {
if (!hashLastBlock.IsNull() && header.hashPrevBlock != hashLastBlock) {
Misbehaving(pfrom->GetId(), 20, "non-continuous headers sequence");
return false;
}
hashLastBlock = header.GetHash();
}
// If we don't have the last header, then they'll have given us
// something new (if these headers are valid).
if (!LookupBlockIndex(hashLastBlock)) {
received_new_header = true;
}
}
BlockValidationState state;
if (!ProcessNewBlockHeaders(headers, state, chainparams, &pindexLast)) {
if (state.IsInvalid()) {
MaybePunishNodeForBlock(pfrom->GetId(), state, via_compact_block, "invalid header received");
return false;
}
}
{
LOCK(cs_main);
CNodeState *nodestate = State(pfrom->GetId());
if (nodestate->nUnconnectingHeaders > 0) {
LogPrint(BCLog::NET, "peer=%d: resetting nUnconnectingHeaders (%d -> 0)\n", pfrom->GetId(), nodestate->nUnconnectingHeaders);
}
nodestate->nUnconnectingHeaders = 0;
assert(pindexLast);
UpdateBlockAvailability(pfrom->GetId(), pindexLast->GetBlockHash());
// From here, pindexBestKnownBlock should be guaranteed to be non-null,
// because it is set in UpdateBlockAvailability. Some nullptr checks
// are still present, however, as belt-and-suspenders.
if (received_new_header && pindexLast->nChainWork > ::ChainActive().Tip()->nChainWork) {
nodestate->m_last_block_announcement = GetTime();
}
if (nCount == MAX_HEADERS_RESULTS) {
// Headers message had its maximum size; the peer may have more headers.
// TODO: optimize: if pindexLast is an ancestor of ::ChainActive().Tip or pindexBestHeader, continue
// from there instead.
LogPrint(BCLog::NET, "more getheaders (%d) to end to peer=%d (startheight:%d)\n", pindexLast->nHeight, pfrom->GetId(), pfrom->nStartingHeight);
connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::GETHEADERS, ::ChainActive().GetLocator(pindexLast), uint256()));
}
bool fCanDirectFetch = CanDirectFetch(chainparams.GetConsensus());
// If this set of headers is valid and ends in a block with at least as
// much work as our tip, download as much as possible.
if (fCanDirectFetch && pindexLast->IsValid(BLOCK_VALID_TREE) && ::ChainActive().Tip()->nChainWork <= pindexLast->nChainWork) {
std::vector<const CBlockIndex*> vToFetch;
const CBlockIndex *pindexWalk = pindexLast;
// Calculate all the blocks we'd need to switch to pindexLast, up to a limit.
while (pindexWalk && !::ChainActive().Contains(pindexWalk) && vToFetch.size() <= MAX_BLOCKS_IN_TRANSIT_PER_PEER) {
if (!(pindexWalk->nStatus & BLOCK_HAVE_DATA) &&
!mapBlocksInFlight.count(pindexWalk->GetBlockHash()) &&
(!IsWitnessEnabled(pindexWalk->pprev, chainparams.GetConsensus()) || State(pfrom->GetId())->fHaveWitness)) {
// We don't have this block, and it's not yet in flight.
vToFetch.push_back(pindexWalk);
}
pindexWalk = pindexWalk->pprev;
}
// If pindexWalk still isn't on our main chain, we're looking at a
// very large reorg at a time we think we're close to caught up to
// the main chain -- this shouldn't really happen. Bail out on the
// direct fetch and rely on parallel download instead.
if (!::ChainActive().Contains(pindexWalk)) {
LogPrint(BCLog::NET, "Large reorg, won't direct fetch to %s (%d)\n",
pindexLast->GetBlockHash().ToString(),
pindexLast->nHeight);
} else {
std::vector<CInv> vGetData;
// Download as much as possible, from earliest to latest.
for (const CBlockIndex *pindex : reverse_iterate(vToFetch)) {
if (nodestate->nBlocksInFlight >= MAX_BLOCKS_IN_TRANSIT_PER_PEER) {
// Can't download any more from this peer
break;
}
uint32_t nFetchFlags = GetFetchFlags(pfrom);
vGetData.push_back(CInv(MSG_BLOCK | nFetchFlags, pindex->GetBlockHash()));
MarkBlockAsInFlight(mempool, pfrom->GetId(), pindex->GetBlockHash(), pindex);
LogPrint(BCLog::NET, "Requesting block %s from peer=%d\n",
pindex->GetBlockHash().ToString(), pfrom->GetId());
}
if (vGetData.size() > 1) {
LogPrint(BCLog::NET, "Downloading blocks toward %s (%d) via headers direct fetch\n",
pindexLast->GetBlockHash().ToString(), pindexLast->nHeight);
}
if (vGetData.size() > 0) {
if (nodestate->fSupportsDesiredCmpctVersion && vGetData.size() == 1 && mapBlocksInFlight.size() == 1 && pindexLast->pprev->IsValid(BLOCK_VALID_CHAIN)) {
// In any case, we want to download using a compact block, not a regular one
vGetData[0] = CInv(MSG_CMPCT_BLOCK, vGetData[0].hash);
}
connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::GETDATA, vGetData));
}
}
}
// If we're in IBD, we want outbound peers that will serve us a useful
// chain. Disconnect peers that are on chains with insufficient work.
if (::ChainstateActive().IsInitialBlockDownload() && nCount != MAX_HEADERS_RESULTS) {
// When nCount < MAX_HEADERS_RESULTS, we know we have no more
// headers to fetch from this peer.
if (nodestate->pindexBestKnownBlock && nodestate->pindexBestKnownBlock->nChainWork < nMinimumChainWork) {
// This peer has too little work on their headers chain to help
// us sync -- disconnect if using an outbound slot (unless
// whitelisted or addnode).
// Note: We compare their tip to nMinimumChainWork (rather than
// ::ChainActive().Tip()) because we won't start block download
// until we have a headers chain that has at least
// nMinimumChainWork, even if a peer has a chain past our tip,
// as an anti-DoS measure.
if (IsOutboundDisconnectionCandidate(pfrom)) {
LogPrintf("Disconnecting outbound peer %d -- headers chain has insufficient work\n", pfrom->GetId());
pfrom->fDisconnect = true;
}
}
}
if (!pfrom->fDisconnect && IsOutboundDisconnectionCandidate(pfrom) && nodestate->pindexBestKnownBlock != nullptr && pfrom->m_tx_relay != nullptr) {
// If this is an outbound full-relay peer, check to see if we should protect
// it from the bad/lagging chain logic.
// Note that block-relay-only peers are already implicitly protected, so we
// only consider setting m_protect for the full-relay peers.
if (g_outbound_peers_with_protect_from_disconnect < MAX_OUTBOUND_PEERS_TO_PROTECT_FROM_DISCONNECT && nodestate->pindexBestKnownBlock->nChainWork >= ::ChainActive().Tip()->nChainWork && !nodestate->m_chain_sync.m_protect) {
LogPrint(BCLog::NET, "Protecting outbound peer=%d from eviction\n", pfrom->GetId());
nodestate->m_chain_sync.m_protect = true;
++g_outbound_peers_with_protect_from_disconnect;
}
}
}
return true;
}
void static ProcessOrphanTx(CConnman* connman, CTxMemPool& mempool, std::set<uint256>& orphan_work_set, std::list<CTransactionRef>& removed_txn) EXCLUSIVE_LOCKS_REQUIRED(cs_main, g_cs_orphans)
{
AssertLockHeld(cs_main);
AssertLockHeld(g_cs_orphans);
std::set<NodeId> setMisbehaving;
bool done = false;
while (!done && !orphan_work_set.empty()) {
const uint256 orphanHash = *orphan_work_set.begin();
orphan_work_set.erase(orphan_work_set.begin());
auto orphan_it = mapOrphanTransactions.find(orphanHash);
if (orphan_it == mapOrphanTransactions.end()) continue;
const CTransactionRef porphanTx = orphan_it->second.tx;
const CTransaction& orphanTx = *porphanTx;
NodeId fromPeer = orphan_it->second.fromPeer;
// Use a new TxValidationState because orphans come from different peers (and we call
// MaybePunishNodeForTx based on the source peer from the orphan map, not based on the peer
// that relayed the previous transaction).
TxValidationState orphan_state;
if (setMisbehaving.count(fromPeer)) continue;
if (AcceptToMemoryPool(mempool, orphan_state, porphanTx, &removed_txn, false /* bypass_limits */, 0 /* nAbsurdFee */)) {
LogPrint(BCLog::MEMPOOL, " accepted orphan tx %s\n", orphanHash.ToString());
RelayTransaction(orphanHash, *connman);
for (unsigned int i = 0; i < orphanTx.vout.size(); i++) {
auto it_by_prev = mapOrphanTransactionsByPrev.find(COutPoint(orphanHash, i));
if (it_by_prev != mapOrphanTransactionsByPrev.end()) {
for (const auto& elem : it_by_prev->second) {
orphan_work_set.insert(elem->first);
}
}
}
EraseOrphanTx(orphanHash);
done = true;
} else if (orphan_state.GetResult() != TxValidationResult::TX_MISSING_INPUTS) {
if (orphan_state.IsInvalid()) {
// Punish peer that gave us an invalid orphan tx
if (MaybePunishNodeForTx(fromPeer, orphan_state)) {
setMisbehaving.insert(fromPeer);
}
LogPrint(BCLog::MEMPOOL, " invalid orphan tx %s\n", orphanHash.ToString());
}
// Has inputs but not accepted to mempool
// Probably non-standard or insufficient fee
LogPrint(BCLog::MEMPOOL, " removed orphan tx %s\n", orphanHash.ToString());
if (!orphanTx.HasWitness() && orphan_state.GetResult() != TxValidationResult::TX_WITNESS_MUTATED) {
// Do not use rejection cache for witness transactions or
// witness-stripped transactions, as they can have been malleated.
// See https://github.com/bitcoin/bitcoin/issues/8279 for details.
assert(recentRejects);
recentRejects->insert(orphanHash);
}
EraseOrphanTx(orphanHash);
done = true;
}
mempool.check(&::ChainstateActive().CoinsTip());
}
}
bool ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStream& vRecv, int64_t nTimeReceived, const CChainParams& chainparams, CTxMemPool& mempool, CConnman* connman, BanMan* banman, const std::atomic<bool>& interruptMsgProc)
{
LogPrint(BCLog::NET, "received: %s (%u bytes) peer=%d\n", SanitizeString(strCommand), vRecv.size(), pfrom->GetId());
if (gArgs.IsArgSet("-dropmessagestest") && GetRand(gArgs.GetArg("-dropmessagestest", 0)) == 0)
{
LogPrintf("dropmessagestest DROPPING RECV MESSAGE\n");
return true;
}
if (!(pfrom->GetLocalServices() & NODE_BLOOM) &&
(strCommand == NetMsgType::FILTERLOAD ||
strCommand == NetMsgType::FILTERADD))
{
if (pfrom->nVersion >= NO_BLOOM_VERSION) {
LOCK(cs_main);
Misbehaving(pfrom->GetId(), 100);
return false;
} else {
pfrom->fDisconnect = true;
return false;
}
}
if (strCommand == NetMsgType::VERSION) {
// Each connection can only send one version message
if (pfrom->nVersion != 0)
{
LOCK(cs_main);
Misbehaving(pfrom->GetId(), 1);
return false;
}
int64_t nTime;
CAddress addrMe;
CAddress addrFrom;
uint64_t nNonce = 1;
uint64_t nServiceInt;
ServiceFlags nServices;
int nVersion;
int nSendVersion;
std::string cleanSubVer;
int nStartingHeight = -1;
bool fRelay = true;
vRecv >> nVersion >> nServiceInt >> nTime >> addrMe;
nSendVersion = std::min(nVersion, PROTOCOL_VERSION);
nServices = ServiceFlags(nServiceInt);
if (!pfrom->fInbound)
{
connman->SetServices(pfrom->addr, nServices);
}
if (!pfrom->fInbound && !pfrom->fFeeler && !pfrom->m_manual_connection && !HasAllDesirableServiceFlags(nServices))
{
LogPrint(BCLog::NET, "peer=%d does not offer the expected services (%08x offered, %08x expected); disconnecting\n", pfrom->GetId(), nServices, GetDesirableServiceFlags(nServices));
pfrom->fDisconnect = true;
return false;
}
if (nVersion < MIN_PEER_PROTO_VERSION) {
// disconnect from peers older than this proto version
LogPrint(BCLog::NET, "peer=%d using obsolete version %i; disconnecting\n", pfrom->GetId(), nVersion);
pfrom->fDisconnect = true;
return false;
}
if (!vRecv.empty())
vRecv >> addrFrom >> nNonce;
if (!vRecv.empty()) {
std::string strSubVer;
vRecv >> LIMITED_STRING(strSubVer, MAX_SUBVERSION_LENGTH);
cleanSubVer = SanitizeString(strSubVer);
}
if (!vRecv.empty()) {
vRecv >> nStartingHeight;
}
if (!vRecv.empty())
vRecv >> fRelay;
// Disconnect if we connected to ourself
if (pfrom->fInbound && !connman->CheckIncomingNonce(nNonce))
{
LogPrintf("connected to self at %s, disconnecting\n", pfrom->addr.ToString());
pfrom->fDisconnect = true;
return true;
}
if (pfrom->fInbound && addrMe.IsRoutable())
{
SeenLocal(addrMe);
}
// Be shy and don't send version until we hear
if (pfrom->fInbound)
PushNodeVersion(pfrom, connman, GetAdjustedTime());
connman->PushMessage(pfrom, CNetMsgMaker(INIT_PROTO_VERSION).Make(NetMsgType::VERACK));
pfrom->nServices = nServices;
pfrom->SetAddrLocal(addrMe);
{
LOCK(pfrom->cs_SubVer);
pfrom->cleanSubVer = cleanSubVer;
}
pfrom->nStartingHeight = nStartingHeight;
// set nodes not relaying blocks and tx and not serving (parts) of the historical blockchain as "clients"
pfrom->fClient = (!(nServices & NODE_NETWORK) && !(nServices & NODE_NETWORK_LIMITED));
// set nodes not capable of serving the complete blockchain history as "limited nodes"
pfrom->m_limited_node = (!(nServices & NODE_NETWORK) && (nServices & NODE_NETWORK_LIMITED));
if (pfrom->m_tx_relay != nullptr) {
LOCK(pfrom->m_tx_relay->cs_filter);
pfrom->m_tx_relay->fRelayTxes = fRelay; // set to true after we get the first filter* message
}
// Change version
pfrom->SetSendVersion(nSendVersion);
pfrom->nVersion = nVersion;
if((nServices & NODE_WITNESS))
{
LOCK(cs_main);
State(pfrom->GetId())->fHaveWitness = true;
}
// Potentially mark this peer as a preferred download peer.
{
LOCK(cs_main);
UpdatePreferredDownload(pfrom, State(pfrom->GetId()));
}
if (!pfrom->fInbound && pfrom->IsAddrRelayPeer())
{
// Advertise our address
if (fListen && !::ChainstateActive().IsInitialBlockDownload())
{
CAddress addr = GetLocalAddress(&pfrom->addr, pfrom->GetLocalServices());
FastRandomContext insecure_rand;
if (addr.IsRoutable())
{
LogPrint(BCLog::NET, "ProcessMessages: advertising address %s\n", addr.ToString());
pfrom->PushAddress(addr, insecure_rand);
} else if (IsPeerAddrLocalGood(pfrom)) {
addr.SetIP(addrMe);
LogPrint(BCLog::NET, "ProcessMessages: advertising address %s\n", addr.ToString());
pfrom->PushAddress(addr, insecure_rand);
}
}
// Get recent addresses
if (pfrom->fOneShot || pfrom->nVersion >= CADDR_TIME_VERSION || connman->GetAddressCount() < 1000)
{
connman->PushMessage(pfrom, CNetMsgMaker(nSendVersion).Make(NetMsgType::GETADDR));
pfrom->fGetAddr = true;
}
connman->MarkAddressGood(pfrom->addr);
}
std::string remoteAddr;
if (fLogIPs)
remoteAddr = ", peeraddr=" + pfrom->addr.ToString();
LogPrint(BCLog::NET, "receive version message: %s: version %d, blocks=%d, us=%s, peer=%d%s\n",
cleanSubVer, pfrom->nVersion,
pfrom->nStartingHeight, addrMe.ToString(), pfrom->GetId(),
remoteAddr);
int64_t nTimeOffset = nTime - GetTime();
pfrom->nTimeOffset = nTimeOffset;
AddTimeData(pfrom->addr, nTimeOffset);
// If the peer is old enough to have the old alert system, send it the final alert.
if (pfrom->nVersion <= 70012) {
CDataStream finalAlert(ParseHex("60010000000000000000000000ffffff7f00000000ffffff7ffeffff7f01ffffff7f00000000ffffff7f00ffffff7f002f555247454e543a20416c657274206b657920636f6d70726f6d697365642c2075706772616465207265717569726564004630440220653febd6410f470f6bae11cad19c48413becb1ac2c17f908fd0fd53bdc3abd5202206d0e9c96fe88d4a0f01ed9dedae2b6f9e00da94cad0fecaae66ecf689bf71b50"), SER_NETWORK, PROTOCOL_VERSION);
connman->PushMessage(pfrom, CNetMsgMaker(nSendVersion).Make("alert", finalAlert));
}
// Feeler connections exist only to verify if address is online.
if (pfrom->fFeeler) {
assert(pfrom->fInbound == false);
pfrom->fDisconnect = true;
}
return true;
}
if (pfrom->nVersion == 0) {
// Must have a version message before anything else
LOCK(cs_main);
Misbehaving(pfrom->GetId(), 1);
return false;
}
// At this point, the outgoing message serialization version can't change.
const CNetMsgMaker msgMaker(pfrom->GetSendVersion());
if (strCommand == NetMsgType::VERACK)
{
pfrom->SetRecvVersion(std::min(pfrom->nVersion.load(), PROTOCOL_VERSION));
if (!pfrom->fInbound) {
// Mark this node as currently connected, so we update its timestamp later.
LOCK(cs_main);
State(pfrom->GetId())->fCurrentlyConnected = true;
LogPrintf("New outbound peer connected: version: %d, blocks=%d, peer=%d%s (%s)\n",
pfrom->nVersion.load(), pfrom->nStartingHeight,
pfrom->GetId(), (fLogIPs ? strprintf(", peeraddr=%s", pfrom->addr.ToString()) : ""),
pfrom->m_tx_relay == nullptr ? "block-relay" : "full-relay");
}
if (pfrom->nVersion >= SENDHEADERS_VERSION) {
// Tell our peer we prefer to receive headers rather than inv's
// We send this to non-NODE NETWORK peers as well, because even
// non-NODE NETWORK peers can announce blocks (such as pruning
// nodes)
connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::SENDHEADERS));
}
if (pfrom->nVersion >= SHORT_IDS_BLOCKS_VERSION) {
// Tell our peer we are willing to provide version 1 or 2 cmpctblocks
// However, we do not request new block announcements using
// cmpctblock messages.
// We send this to non-NODE NETWORK peers as well, because
// they may wish to request compact blocks from us
bool fAnnounceUsingCMPCTBLOCK = false;
uint64_t nCMPCTBLOCKVersion = 2;
if (pfrom->GetLocalServices() & NODE_WITNESS)
connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::SENDCMPCT, fAnnounceUsingCMPCTBLOCK, nCMPCTBLOCKVersion));
nCMPCTBLOCKVersion = 1;
connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::SENDCMPCT, fAnnounceUsingCMPCTBLOCK, nCMPCTBLOCKVersion));
}
pfrom->fSuccessfullyConnected = true;
return true;
}
if (!pfrom->fSuccessfullyConnected) {
// Must have a verack message before anything else
LOCK(cs_main);
Misbehaving(pfrom->GetId(), 1);
return false;
}
if (strCommand == NetMsgType::ADDR) {
std::vector<CAddress> vAddr;
vRecv >> vAddr;
// Don't want addr from older versions unless seeding
if (pfrom->nVersion < CADDR_TIME_VERSION && connman->GetAddressCount() > 1000)
return true;
if (!pfrom->IsAddrRelayPeer()) {
return true;
}
if (vAddr.size() > 1000)
{
LOCK(cs_main);
Misbehaving(pfrom->GetId(), 20, strprintf("message addr size() = %u", vAddr.size()));
return false;
}
// Store the new addresses
std::vector<CAddress> vAddrOk;
int64_t nNow = GetAdjustedTime();
int64_t nSince = nNow - 10 * 60;
for (CAddress& addr : vAddr)
{
if (interruptMsgProc)
return true;
// We only bother storing full nodes, though this may include
// things which we would not make an outbound connection to, in
// part because we may make feeler connections to them.
if (!MayHaveUsefulAddressDB(addr.nServices) && !HasAllDesirableServiceFlags(addr.nServices))
continue;
if (addr.nTime <= 100000000 || addr.nTime > nNow + 10 * 60)
addr.nTime = nNow - 5 * 24 * 60 * 60;
pfrom->AddAddressKnown(addr);
if (banman->IsBanned(addr)) continue; // Do not process banned addresses beyond remembering we received them
bool fReachable = IsReachable(addr);
if (addr.nTime > nSince && !pfrom->fGetAddr && vAddr.size() <= 10 && addr.IsRoutable())
{
// Relay to a limited number of other nodes
RelayAddress(addr, fReachable, connman);
}
// Do not store addresses outside our network
if (fReachable)
vAddrOk.push_back(addr);
}
connman->AddNewAddresses(vAddrOk, pfrom->addr, 2 * 60 * 60);
if (vAddr.size() < 1000)
pfrom->fGetAddr = false;
if (pfrom->fOneShot)
pfrom->fDisconnect = true;
return true;
}
if (strCommand == NetMsgType::SENDHEADERS) {
LOCK(cs_main);
State(pfrom->GetId())->fPreferHeaders = true;
return true;
}
if (strCommand == NetMsgType::SENDCMPCT) {
bool fAnnounceUsingCMPCTBLOCK = false;
uint64_t nCMPCTBLOCKVersion = 0;
vRecv >> fAnnounceUsingCMPCTBLOCK >> nCMPCTBLOCKVersion;
if (nCMPCTBLOCKVersion == 1 || ((pfrom->GetLocalServices() & NODE_WITNESS) && nCMPCTBLOCKVersion == 2)) {
LOCK(cs_main);
// fProvidesHeaderAndIDs is used to "lock in" version of compact blocks we send (fWantsCmpctWitness)
if (!State(pfrom->GetId())->fProvidesHeaderAndIDs) {
State(pfrom->GetId())->fProvidesHeaderAndIDs = true;
State(pfrom->GetId())->fWantsCmpctWitness = nCMPCTBLOCKVersion == 2;
}
if (State(pfrom->GetId())->fWantsCmpctWitness == (nCMPCTBLOCKVersion == 2)) // ignore later version announces
State(pfrom->GetId())->fPreferHeaderAndIDs = fAnnounceUsingCMPCTBLOCK;
if (!State(pfrom->GetId())->fSupportsDesiredCmpctVersion) {
if (pfrom->GetLocalServices() & NODE_WITNESS)
State(pfrom->GetId())->fSupportsDesiredCmpctVersion = (nCMPCTBLOCKVersion == 2);
else
State(pfrom->GetId())->fSupportsDesiredCmpctVersion = (nCMPCTBLOCKVersion == 1);
}
}
return true;
}
if (strCommand == NetMsgType::INV) {
std::vector<CInv> vInv;
vRecv >> vInv;
if (vInv.size() > MAX_INV_SZ)
{
LOCK(cs_main);
Misbehaving(pfrom->GetId(), 20, strprintf("message inv size() = %u", vInv.size()));
return false;
}
// We won't accept tx inv's if we're in blocks-only mode, or this is a
// block-relay-only peer
bool fBlocksOnly = !g_relay_txes || (pfrom->m_tx_relay == nullptr);
// Allow whitelisted peers to send data other than blocks in blocks only mode if whitelistrelay is true
if (pfrom->HasPermission(PF_RELAY))
fBlocksOnly = false;
LOCK(cs_main);
uint32_t nFetchFlags = GetFetchFlags(pfrom);
const auto current_time = GetTime<std::chrono::microseconds>();
for (CInv &inv : vInv)
{
if (interruptMsgProc)
return true;
bool fAlreadyHave = AlreadyHave(inv, mempool);
LogPrint(BCLog::NET, "got inv: %s %s peer=%d\n", inv.ToString(), fAlreadyHave ? "have" : "new", pfrom->GetId());
if (inv.type == MSG_TX) {
inv.type |= nFetchFlags;
}
if (inv.type == MSG_BLOCK) {
UpdateBlockAvailability(pfrom->GetId(), inv.hash);
if (!fAlreadyHave && !fImporting && !fReindex && !mapBlocksInFlight.count(inv.hash)) {
// We used to request the full block here, but since headers-announcements are now the
// primary method of announcement on the network, and since, in the case that a node
// fell back to inv we probably have a reorg which we should get the headers for first,
// we now only provide a getheaders response here. When we receive the headers, we will
// then ask for the blocks we need.
connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::GETHEADERS, ::ChainActive().GetLocator(pindexBestHeader), inv.hash));
LogPrint(BCLog::NET, "getheaders (%d) %s to peer=%d\n", pindexBestHeader->nHeight, inv.hash.ToString(), pfrom->GetId());
}
}
else
{
pfrom->AddInventoryKnown(inv);
if (fBlocksOnly) {
LogPrint(BCLog::NET, "transaction (%s) inv sent in violation of protocol, disconnecting peer=%d\n", inv.hash.ToString(), pfrom->GetId());
pfrom->fDisconnect = true;
return true;
} else if (!fAlreadyHave && !fImporting && !fReindex && !::ChainstateActive().IsInitialBlockDownload()) {
RequestTx(State(pfrom->GetId()), inv.hash, current_time);
}
}
}
return true;
}
if (strCommand == NetMsgType::GETDATA) {
std::vector<CInv> vInv;
vRecv >> vInv;
if (vInv.size() > MAX_INV_SZ)
{
LOCK(cs_main);
Misbehaving(pfrom->GetId(), 20, strprintf("message getdata size() = %u", vInv.size()));
return false;
}
LogPrint(BCLog::NET, "received getdata (%u invsz) peer=%d\n", vInv.size(), pfrom->GetId());
if (vInv.size() > 0) {
LogPrint(BCLog::NET, "received getdata for: %s peer=%d\n", vInv[0].ToString(), pfrom->GetId());
}
pfrom->vRecvGetData.insert(pfrom->vRecvGetData.end(), vInv.begin(), vInv.end());
ProcessGetData(pfrom, chainparams, connman, mempool, interruptMsgProc);
return true;
}
if (strCommand == NetMsgType::GETBLOCKS) {
CBlockLocator locator;
uint256 hashStop;
vRecv >> locator >> hashStop;
if (locator.vHave.size() > MAX_LOCATOR_SZ) {
LogPrint(BCLog::NET, "getblocks locator size %lld > %d, disconnect peer=%d\n", locator.vHave.size(), MAX_LOCATOR_SZ, pfrom->GetId());
pfrom->fDisconnect = true;
return true;
}
// We might have announced the currently-being-connected tip using a
// compact block, which resulted in the peer sending a getblocks
// request, which we would otherwise respond to without the new block.
// To avoid this situation we simply verify that we are on our best
// known chain now. This is super overkill, but we handle it better
// for getheaders requests, and there are no known nodes which support
// compact blocks but still use getblocks to request blocks.
{
std::shared_ptr<const CBlock> a_recent_block;
{
LOCK(cs_most_recent_block);
a_recent_block = most_recent_block;
}
BlockValidationState state;
if (!ActivateBestChain(state, Params(), a_recent_block)) {
LogPrint(BCLog::NET, "failed to activate chain (%s)\n", state.ToString());
}
}
LOCK(cs_main);
// Find the last block the caller has in the main chain
const CBlockIndex* pindex = FindForkInGlobalIndex(::ChainActive(), locator);
// Send the rest of the chain
if (pindex)
pindex = ::ChainActive().Next(pindex);
int nLimit = 500;
LogPrint(BCLog::NET, "getblocks %d to %s limit %d from peer=%d\n", (pindex ? pindex->nHeight : -1), hashStop.IsNull() ? "end" : hashStop.ToString(), nLimit, pfrom->GetId());
for (; pindex; pindex = ::ChainActive().Next(pindex))
{
if (pindex->GetBlockHash() == hashStop)
{
LogPrint(BCLog::NET, " getblocks stopping at %d %s\n", pindex->nHeight, pindex->GetBlockHash().ToString());
break;
}
// If pruning, don't inv blocks unless we have on disk and are likely to still have
// for some reasonable time window (1 hour) that block relay might require.
const int nPrunedBlocksLikelyToHave = MIN_BLOCKS_TO_KEEP - 3600 / chainparams.GetConsensus().nPowTargetSpacing;
if (fPruneMode && (!(pindex->nStatus & BLOCK_HAVE_DATA) || pindex->nHeight <= ::ChainActive().Tip()->nHeight - nPrunedBlocksLikelyToHave))
{
LogPrint(BCLog::NET, " getblocks stopping, pruned or too old block at %d %s\n", pindex->nHeight, pindex->GetBlockHash().ToString());
break;
}
pfrom->PushInventory(CInv(MSG_BLOCK, pindex->GetBlockHash()));
if (--nLimit <= 0)
{
// When this block is requested, we'll send an inv that'll
// trigger the peer to getblocks the next batch of inventory.
LogPrint(BCLog::NET, " getblocks stopping at limit %d %s\n", pindex->nHeight, pindex->GetBlockHash().ToString());
pfrom->hashContinue = pindex->GetBlockHash();
break;
}
}
return true;
}
if (strCommand == NetMsgType::GETBLOCKTXN) {
BlockTransactionsRequest req;
vRecv >> req;
std::shared_ptr<const CBlock> recent_block;
{
LOCK(cs_most_recent_block);
if (most_recent_block_hash == req.blockhash)
recent_block = most_recent_block;
// Unlock cs_most_recent_block to avoid cs_main lock inversion
}
if (recent_block) {
SendBlockTransactions(*recent_block, req, pfrom, connman);
return true;
}
LOCK(cs_main);
const CBlockIndex* pindex = LookupBlockIndex(req.blockhash);
if (!pindex || !(pindex->nStatus & BLOCK_HAVE_DATA)) {
LogPrint(BCLog::NET, "Peer %d sent us a getblocktxn for a block we don't have\n", pfrom->GetId());
return true;
}
if (pindex->nHeight < ::ChainActive().Height() - MAX_BLOCKTXN_DEPTH) {
// If an older block is requested (should never happen in practice,
// but can happen in tests) send a block response instead of a
// blocktxn response. Sending a full block response instead of a
// small blocktxn response is preferable in the case where a peer
// might maliciously send lots of getblocktxn requests to trigger
// expensive disk reads, because it will require the peer to
// actually receive all the data read from disk over the network.
LogPrint(BCLog::NET, "Peer %d sent us a getblocktxn for a block > %i deep\n", pfrom->GetId(), MAX_BLOCKTXN_DEPTH);
CInv inv;
inv.type = State(pfrom->GetId())->fWantsCmpctWitness ? MSG_WITNESS_BLOCK : MSG_BLOCK;
inv.hash = req.blockhash;
pfrom->vRecvGetData.push_back(inv);
// The message processing loop will go around again (without pausing) and we'll respond then (without cs_main)
return true;
}
CBlock block;
bool ret = ReadBlockFromDisk(block, pindex, chainparams.GetConsensus());
assert(ret);
SendBlockTransactions(block, req, pfrom, connman);
return true;
}
if (strCommand == NetMsgType::GETHEADERS) {
CBlockLocator locator;
uint256 hashStop;
vRecv >> locator >> hashStop;
if (locator.vHave.size() > MAX_LOCATOR_SZ) {
LogPrint(BCLog::NET, "getheaders locator size %lld > %d, disconnect peer=%d\n", locator.vHave.size(), MAX_LOCATOR_SZ, pfrom->GetId());
pfrom->fDisconnect = true;
return true;
}
LOCK(cs_main);
if (::ChainstateActive().IsInitialBlockDownload() && !pfrom->HasPermission(PF_NOBAN)) {
LogPrint(BCLog::NET, "Ignoring getheaders from peer=%d because node is in initial block download\n", pfrom->GetId());
return true;
}
CNodeState *nodestate = State(pfrom->GetId());
const CBlockIndex* pindex = nullptr;
if (locator.IsNull())
{
// If locator is null, return the hashStop block
pindex = LookupBlockIndex(hashStop);
if (!pindex) {
return true;
}
if (!BlockRequestAllowed(pindex, chainparams.GetConsensus())) {
LogPrint(BCLog::NET, "%s: ignoring request from peer=%i for old block header that isn't in the main chain\n", __func__, pfrom->GetId());
return true;
}
}
else
{
// Find the last block the caller has in the main chain
pindex = FindForkInGlobalIndex(::ChainActive(), locator);
if (pindex)
pindex = ::ChainActive().Next(pindex);
}
// we must use CBlocks, as CBlockHeaders won't include the 0x00 nTx count at the end
std::vector<CBlock> vHeaders;
int nLimit = MAX_HEADERS_RESULTS;
LogPrint(BCLog::NET, "getheaders %d to %s from peer=%d\n", (pindex ? pindex->nHeight : -1), hashStop.IsNull() ? "end" : hashStop.ToString(), pfrom->GetId());
for (; pindex; pindex = ::ChainActive().Next(pindex))
{
vHeaders.push_back(pindex->GetBlockHeader());
if (--nLimit <= 0 || pindex->GetBlockHash() == hashStop)
break;
}
// pindex can be nullptr either if we sent ::ChainActive().Tip() OR
// if our peer has ::ChainActive().Tip() (and thus we are sending an empty
// headers message). In both cases it's safe to update
// pindexBestHeaderSent to be our tip.
//
// It is important that we simply reset the BestHeaderSent value here,
// and not max(BestHeaderSent, newHeaderSent). We might have announced
// the currently-being-connected tip using a compact block, which
// resulted in the peer sending a headers request, which we respond to
// without the new block. By resetting the BestHeaderSent, we ensure we
// will re-announce the new block via headers (or compact blocks again)
// in the SendMessages logic.
nodestate->pindexBestHeaderSent = pindex ? pindex : ::ChainActive().Tip();
connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::HEADERS, vHeaders));
return true;
}
if (strCommand == NetMsgType::TX) {
// Stop processing the transaction early if
// We are in blocks only mode and peer is either not whitelisted or whitelistrelay is off
// or if this peer is supposed to be a block-relay-only peer
if ((!g_relay_txes && !pfrom->HasPermission(PF_RELAY)) || (pfrom->m_tx_relay == nullptr))
{
LogPrint(BCLog::NET, "transaction sent in violation of protocol peer=%d\n", pfrom->GetId());
pfrom->fDisconnect = true;
return true;
}
CTransactionRef ptx;
vRecv >> ptx;
const CTransaction& tx = *ptx;
CInv inv(MSG_TX, tx.GetHash());
pfrom->AddInventoryKnown(inv);
LOCK2(cs_main, g_cs_orphans);
TxValidationState state;
CNodeState* nodestate = State(pfrom->GetId());
nodestate->m_tx_download.m_tx_announced.erase(inv.hash);
nodestate->m_tx_download.m_tx_in_flight.erase(inv.hash);
EraseTxRequest(inv.hash);
std::list<CTransactionRef> lRemovedTxn;
if (!AlreadyHave(inv, mempool) &&
AcceptToMemoryPool(mempool, state, ptx, &lRemovedTxn, false /* bypass_limits */, 0 /* nAbsurdFee */)) {
mempool.check(&::ChainstateActive().CoinsTip());
RelayTransaction(tx.GetHash(), *connman);
for (unsigned int i = 0; i < tx.vout.size(); i++) {
auto it_by_prev = mapOrphanTransactionsByPrev.find(COutPoint(inv.hash, i));
if (it_by_prev != mapOrphanTransactionsByPrev.end()) {
for (const auto& elem : it_by_prev->second) {
pfrom->orphan_work_set.insert(elem->first);
}
}
}
pfrom->nLastTXTime = GetTime();
LogPrint(BCLog::MEMPOOL, "AcceptToMemoryPool: peer=%d: accepted %s (poolsz %u txn, %u kB)\n",
pfrom->GetId(),
tx.GetHash().ToString(),
mempool.size(), mempool.DynamicMemoryUsage() / 1000);
// Recursively process any orphan transactions that depended on this one
ProcessOrphanTx(connman, mempool, pfrom->orphan_work_set, lRemovedTxn);
}
else if (state.GetResult() == TxValidationResult::TX_MISSING_INPUTS)
{
bool fRejectedParents = false; // It may be the case that the orphans parents have all been rejected
for (const CTxIn& txin : tx.vin) {
if (recentRejects->contains(txin.prevout.hash)) {
fRejectedParents = true;
break;
}
}
if (!fRejectedParents) {
uint32_t nFetchFlags = GetFetchFlags(pfrom);
const auto current_time = GetTime<std::chrono::microseconds>();
for (const CTxIn& txin : tx.vin) {
CInv _inv(MSG_TX | nFetchFlags, txin.prevout.hash);
pfrom->AddInventoryKnown(_inv);
if (!AlreadyHave(_inv, mempool)) RequestTx(State(pfrom->GetId()), _inv.hash, current_time);
}
AddOrphanTx(ptx, pfrom->GetId());
// DoS prevention: do not allow mapOrphanTransactions to grow unbounded (see CVE-2012-3789)
unsigned int nMaxOrphanTx = (unsigned int)std::max((int64_t)0, gArgs.GetArg("-maxorphantx", DEFAULT_MAX_ORPHAN_TRANSACTIONS));
unsigned int nEvicted = LimitOrphanTxSize(nMaxOrphanTx);
if (nEvicted > 0) {
LogPrint(BCLog::MEMPOOL, "mapOrphan overflow, removed %u tx\n", nEvicted);
}
} else {
LogPrint(BCLog::MEMPOOL, "not keeping orphan with rejected parents %s\n",tx.GetHash().ToString());
// We will continue to reject this tx since it has rejected
// parents so avoid re-requesting it from other peers.
recentRejects->insert(tx.GetHash());
}
} else {
if (!tx.HasWitness() && state.GetResult() != TxValidationResult::TX_WITNESS_MUTATED) {
// Do not use rejection cache for witness transactions or
// witness-stripped transactions, as they can have been malleated.
// See https://github.com/bitcoin/bitcoin/issues/8279 for details.
assert(recentRejects);
recentRejects->insert(tx.GetHash());
if (RecursiveDynamicUsage(*ptx) < 100000) {
AddToCompactExtraTransactions(ptx);
}
} else if (tx.HasWitness() && RecursiveDynamicUsage(*ptx) < 100000) {
AddToCompactExtraTransactions(ptx);
}
if (pfrom->HasPermission(PF_FORCERELAY)) {
// Always relay transactions received from whitelisted peers, even
// if they were already in the mempool,
// allowing the node to function as a gateway for
// nodes hidden behind it.
if (!mempool.exists(tx.GetHash())) {
LogPrintf("Not relaying non-mempool transaction %s from whitelisted peer=%d\n", tx.GetHash().ToString(), pfrom->GetId());
} else {
LogPrintf("Force relaying tx %s from whitelisted peer=%d\n", tx.GetHash().ToString(), pfrom->GetId());
RelayTransaction(tx.GetHash(), *connman);
}
}
}
for (const CTransactionRef& removedTx : lRemovedTxn)
AddToCompactExtraTransactions(removedTx);
// If a tx has been detected by recentRejects, we will have reached
// this point and the tx will have been ignored. Because we haven't run
// the tx through AcceptToMemoryPool, we won't have computed a DoS
// score for it or determined exactly why we consider it invalid.
//
// This means we won't penalize any peer subsequently relaying a DoSy
// tx (even if we penalized the first peer who gave it to us) because
// we have to account for recentRejects showing false positives. In
// other words, we shouldn't penalize a peer if we aren't *sure* they
// submitted a DoSy tx.
//
// Note that recentRejects doesn't just record DoSy or invalid
// transactions, but any tx not accepted by the mempool, which may be
// due to node policy (vs. consensus). So we can't blanket penalize a
// peer simply for relaying a tx that our recentRejects has caught,
// regardless of false positives.
if (state.IsInvalid())
{
LogPrint(BCLog::MEMPOOLREJ, "%s from peer=%d was not accepted: %s\n", tx.GetHash().ToString(),
pfrom->GetId(),
state.ToString());
MaybePunishNodeForTx(pfrom->GetId(), state);
}
return true;
}
if (strCommand == NetMsgType::CMPCTBLOCK)
{
// Ignore cmpctblock received while importing
if (fImporting || fReindex) {
LogPrint(BCLog::NET, "Unexpected cmpctblock message received from peer %d\n", pfrom->GetId());
return true;
}
CBlockHeaderAndShortTxIDs cmpctblock;
vRecv >> cmpctblock;
bool received_new_header = false;
{
LOCK(cs_main);
if (!LookupBlockIndex(cmpctblock.header.hashPrevBlock)) {
// Doesn't connect (or is genesis), instead of DoSing in AcceptBlockHeader, request deeper headers
if (!::ChainstateActive().IsInitialBlockDownload())
connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::GETHEADERS, ::ChainActive().GetLocator(pindexBestHeader), uint256()));
return true;
}
if (!LookupBlockIndex(cmpctblock.header.GetHash())) {
received_new_header = true;
}
}
const CBlockIndex *pindex = nullptr;
BlockValidationState state;
if (!ProcessNewBlockHeaders({cmpctblock.header}, state, chainparams, &pindex)) {
if (state.IsInvalid()) {
MaybePunishNodeForBlock(pfrom->GetId(), state, /*via_compact_block*/ true, "invalid header via cmpctblock");
return true;
}
}
// When we succeed in decoding a block's txids from a cmpctblock
// message we typically jump to the BLOCKTXN handling code, with a
// dummy (empty) BLOCKTXN message, to re-use the logic there in
// completing processing of the putative block (without cs_main).
bool fProcessBLOCKTXN = false;
CDataStream blockTxnMsg(SER_NETWORK, PROTOCOL_VERSION);
// If we end up treating this as a plain headers message, call that as well
// without cs_main.
bool fRevertToHeaderProcessing = false;
// Keep a CBlock for "optimistic" compactblock reconstructions (see
// below)
std::shared_ptr<CBlock> pblock = std::make_shared<CBlock>();
bool fBlockReconstructed = false;
{
LOCK2(cs_main, g_cs_orphans);
// If AcceptBlockHeader returned true, it set pindex
assert(pindex);
UpdateBlockAvailability(pfrom->GetId(), pindex->GetBlockHash());
CNodeState *nodestate = State(pfrom->GetId());
// If this was a new header with more work than our tip, update the
// peer's last block announcement time
if (received_new_header && pindex->nChainWork > ::ChainActive().Tip()->nChainWork) {
nodestate->m_last_block_announcement = GetTime();
}
std::map<uint256, std::pair<NodeId, std::list<QueuedBlock>::iterator> >::iterator blockInFlightIt = mapBlocksInFlight.find(pindex->GetBlockHash());
bool fAlreadyInFlight = blockInFlightIt != mapBlocksInFlight.end();
if (pindex->nStatus & BLOCK_HAVE_DATA) // Nothing to do here
return true;
if (pindex->nChainWork <= ::ChainActive().Tip()->nChainWork || // We know something better
pindex->nTx != 0) { // We had this block at some point, but pruned it
if (fAlreadyInFlight) {
// We requested this block for some reason, but our mempool will probably be useless
// so we just grab the block via normal getdata
std::vector<CInv> vInv(1);
vInv[0] = CInv(MSG_BLOCK | GetFetchFlags(pfrom), cmpctblock.header.GetHash());
connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::GETDATA, vInv));
}
return true;
}
// If we're not close to tip yet, give up and let parallel block fetch work its magic
if (!fAlreadyInFlight && !CanDirectFetch(chainparams.GetConsensus()))
return true;
if (IsWitnessEnabled(pindex->pprev, chainparams.GetConsensus()) && !nodestate->fSupportsDesiredCmpctVersion) {
// Don't bother trying to process compact blocks from v1 peers
// after segwit activates.
return true;
}
// We want to be a bit conservative just to be extra careful about DoS
// possibilities in compact block processing...
if (pindex->nHeight <= ::ChainActive().Height() + 2) {
if ((!fAlreadyInFlight && nodestate->nBlocksInFlight < MAX_BLOCKS_IN_TRANSIT_PER_PEER) ||
(fAlreadyInFlight && blockInFlightIt->second.first == pfrom->GetId())) {
std::list<QueuedBlock>::iterator* queuedBlockIt = nullptr;
if (!MarkBlockAsInFlight(mempool, pfrom->GetId(), pindex->GetBlockHash(), pindex, &queuedBlockIt)) {
if (!(*queuedBlockIt)->partialBlock)
(*queuedBlockIt)->partialBlock.reset(new PartiallyDownloadedBlock(&mempool));
else {
// The block was already in flight using compact blocks from the same peer
LogPrint(BCLog::NET, "Peer sent us compact block we were already syncing!\n");
return true;
}
}
PartiallyDownloadedBlock& partialBlock = *(*queuedBlockIt)->partialBlock;
ReadStatus status = partialBlock.InitData(cmpctblock, vExtraTxnForCompact);
if (status == READ_STATUS_INVALID) {
MarkBlockAsReceived(pindex->GetBlockHash()); // Reset in-flight state in case of whitelist
Misbehaving(pfrom->GetId(), 100, strprintf("Peer %d sent us invalid compact block\n", pfrom->GetId()));
return true;
} else if (status == READ_STATUS_FAILED) {
// Duplicate txindexes, the block is now in-flight, so just request it
std::vector<CInv> vInv(1);
vInv[0] = CInv(MSG_BLOCK | GetFetchFlags(pfrom), cmpctblock.header.GetHash());
connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::GETDATA, vInv));
return true;
}
BlockTransactionsRequest req;
for (size_t i = 0; i < cmpctblock.BlockTxCount(); i++) {
if (!partialBlock.IsTxAvailable(i))
req.indexes.push_back(i);
}
if (req.indexes.empty()) {
// Dirty hack to jump to BLOCKTXN code (TODO: move message handling into their own functions)
BlockTransactions txn;
txn.blockhash = cmpctblock.header.GetHash();
blockTxnMsg << txn;
fProcessBLOCKTXN = true;
} else {
req.blockhash = pindex->GetBlockHash();
connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::GETBLOCKTXN, req));
}
} else {
// This block is either already in flight from a different
// peer, or this peer has too many blocks outstanding to
// download from.
// Optimistically try to reconstruct anyway since we might be
// able to without any round trips.
PartiallyDownloadedBlock tempBlock(&mempool);
ReadStatus status = tempBlock.InitData(cmpctblock, vExtraTxnForCompact);
if (status != READ_STATUS_OK) {
// TODO: don't ignore failures
return true;
}
std::vector<CTransactionRef> dummy;
status = tempBlock.FillBlock(*pblock, dummy);
if (status == READ_STATUS_OK) {
fBlockReconstructed = true;
}
}
} else {
if (fAlreadyInFlight) {
// We requested this block, but its far into the future, so our
// mempool will probably be useless - request the block normally
std::vector<CInv> vInv(1);
vInv[0] = CInv(MSG_BLOCK | GetFetchFlags(pfrom), cmpctblock.header.GetHash());
connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::GETDATA, vInv));
return true;
} else {
// If this was an announce-cmpctblock, we want the same treatment as a header message
fRevertToHeaderProcessing = true;
}
}
} // cs_main
if (fProcessBLOCKTXN)
return ProcessMessage(pfrom, NetMsgType::BLOCKTXN, blockTxnMsg, nTimeReceived, chainparams, mempool, connman, banman, interruptMsgProc);
if (fRevertToHeaderProcessing) {
// Headers received from HB compact block peers are permitted to be
// relayed before full validation (see BIP 152), so we don't want to disconnect
// the peer if the header turns out to be for an invalid block.
// Note that if a peer tries to build on an invalid chain, that
// will be detected and the peer will be banned.
return ProcessHeadersMessage(pfrom, connman, mempool, {cmpctblock.header}, chainparams, /*via_compact_block=*/true);
}
if (fBlockReconstructed) {
// If we got here, we were able to optimistically reconstruct a
// block that is in flight from some other peer.
{
LOCK(cs_main);
mapBlockSource.emplace(pblock->GetHash(), std::make_pair(pfrom->GetId(), false));
}
bool fNewBlock = false;
// Setting fForceProcessing to true means that we bypass some of
// our anti-DoS protections in AcceptBlock, which filters
// unrequested blocks that might be trying to waste our resources
// (eg disk space). Because we only try to reconstruct blocks when
// we're close to caught up (via the CanDirectFetch() requirement
// above, combined with the behavior of not requesting blocks until
// we have a chain with at least nMinimumChainWork), and we ignore
// compact blocks with less work than our tip, it is safe to treat
// reconstructed compact blocks as having been requested.
ProcessNewBlock(chainparams, pblock, /*fForceProcessing=*/true, &fNewBlock);
if (fNewBlock) {
pfrom->nLastBlockTime = GetTime();
} else {
LOCK(cs_main);
mapBlockSource.erase(pblock->GetHash());
}
LOCK(cs_main); // hold cs_main for CBlockIndex::IsValid()
if (pindex->IsValid(BLOCK_VALID_TRANSACTIONS)) {
// Clear download state for this block, which is in
// process from some other peer. We do this after calling
// ProcessNewBlock so that a malleated cmpctblock announcement
// can't be used to interfere with block relay.
MarkBlockAsReceived(pblock->GetHash());
}
}
return true;
}
if (strCommand == NetMsgType::BLOCKTXN)
{
// Ignore blocktxn received while importing
if (fImporting || fReindex) {
LogPrint(BCLog::NET, "Unexpected blocktxn message received from peer %d\n", pfrom->GetId());
return true;
}
BlockTransactions resp;
vRecv >> resp;
std::shared_ptr<CBlock> pblock = std::make_shared<CBlock>();
bool fBlockRead = false;
{
LOCK(cs_main);
std::map<uint256, std::pair<NodeId, std::list<QueuedBlock>::iterator> >::iterator it = mapBlocksInFlight.find(resp.blockhash);
if (it == mapBlocksInFlight.end() || !it->second.second->partialBlock ||
it->second.first != pfrom->GetId()) {
LogPrint(BCLog::NET, "Peer %d sent us block transactions for block we weren't expecting\n", pfrom->GetId());
return true;
}
PartiallyDownloadedBlock& partialBlock = *it->second.second->partialBlock;
ReadStatus status = partialBlock.FillBlock(*pblock, resp.txn);
if (status == READ_STATUS_INVALID) {
MarkBlockAsReceived(resp.blockhash); // Reset in-flight state in case of whitelist
Misbehaving(pfrom->GetId(), 100, strprintf("Peer %d sent us invalid compact block/non-matching block transactions\n", pfrom->GetId()));
return true;
} else if (status == READ_STATUS_FAILED) {
// Might have collided, fall back to getdata now :(
std::vector<CInv> invs;
invs.push_back(CInv(MSG_BLOCK | GetFetchFlags(pfrom), resp.blockhash));
connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::GETDATA, invs));
} else {
// Block is either okay, or possibly we received
// READ_STATUS_CHECKBLOCK_FAILED.
// Note that CheckBlock can only fail for one of a few reasons:
// 1. bad-proof-of-work (impossible here, because we've already
// accepted the header)
// 2. merkleroot doesn't match the transactions given (already
// caught in FillBlock with READ_STATUS_FAILED, so
// impossible here)
// 3. the block is otherwise invalid (eg invalid coinbase,
// block is too big, too many legacy sigops, etc).
// So if CheckBlock failed, #3 is the only possibility.
// Under BIP 152, we don't DoS-ban unless proof of work is
// invalid (we don't require all the stateless checks to have
// been run). This is handled below, so just treat this as
// though the block was successfully read, and rely on the
// handling in ProcessNewBlock to ensure the block index is
// updated, etc.
MarkBlockAsReceived(resp.blockhash); // it is now an empty pointer
fBlockRead = true;
// mapBlockSource is used for potentially punishing peers and
// updating which peers send us compact blocks, so the race
// between here and cs_main in ProcessNewBlock is fine.
// BIP 152 permits peers to relay compact blocks after validating
// the header only; we should not punish peers if the block turns
// out to be invalid.
mapBlockSource.emplace(resp.blockhash, std::make_pair(pfrom->GetId(), false));
}
} // Don't hold cs_main when we call into ProcessNewBlock
if (fBlockRead) {
bool fNewBlock = false;
// Since we requested this block (it was in mapBlocksInFlight), force it to be processed,
// even if it would not be a candidate for new tip (missing previous block, chain not long enough, etc)
// This bypasses some anti-DoS logic in AcceptBlock (eg to prevent
// disk-space attacks), but this should be safe due to the
// protections in the compact block handler -- see related comment
// in compact block optimistic reconstruction handling.
ProcessNewBlock(chainparams, pblock, /*fForceProcessing=*/true, &fNewBlock);
if (fNewBlock) {
pfrom->nLastBlockTime = GetTime();
} else {
LOCK(cs_main);
mapBlockSource.erase(pblock->GetHash());
}
}
return true;
}
if (strCommand == NetMsgType::HEADERS)
{
// Ignore headers received while importing
if (fImporting || fReindex) {
LogPrint(BCLog::NET, "Unexpected headers message received from peer %d\n", pfrom->GetId());
return true;
}
std::vector<CBlockHeader> headers;
// Bypass the normal CBlock deserialization, as we don't want to risk deserializing 2000 full blocks.
unsigned int nCount = ReadCompactSize(vRecv);
if (nCount > MAX_HEADERS_RESULTS) {
LOCK(cs_main);
Misbehaving(pfrom->GetId(), 20, strprintf("headers message size = %u", nCount));
return false;
}
headers.resize(nCount);
for (unsigned int n = 0; n < nCount; n++) {
vRecv >> headers[n];
ReadCompactSize(vRecv); // ignore tx count; assume it is 0.
}
return ProcessHeadersMessage(pfrom, connman, mempool, headers, chainparams, /*via_compact_block=*/false);
}
if (strCommand == NetMsgType::BLOCK)
{
// Ignore block received while importing
if (fImporting || fReindex) {
LogPrint(BCLog::NET, "Unexpected block message received from peer %d\n", pfrom->GetId());
return true;
}
std::shared_ptr<CBlock> pblock = std::make_shared<CBlock>();
vRecv >> *pblock;
LogPrint(BCLog::NET, "received block %s peer=%d\n", pblock->GetHash().ToString(), pfrom->GetId());
bool forceProcessing = false;
const uint256 hash(pblock->GetHash());
{
LOCK(cs_main);
// Also always process if we requested the block explicitly, as we may
// need it even though it is not a candidate for a new best tip.
forceProcessing |= MarkBlockAsReceived(hash);
// mapBlockSource is only used for punishing peers and setting
// which peers send us compact blocks, so the race between here and
// cs_main in ProcessNewBlock is fine.
mapBlockSource.emplace(hash, std::make_pair(pfrom->GetId(), true));
}
bool fNewBlock = false;
ProcessNewBlock(chainparams, pblock, forceProcessing, &fNewBlock);
if (fNewBlock) {
pfrom->nLastBlockTime = GetTime();
} else {
LOCK(cs_main);
mapBlockSource.erase(pblock->GetHash());
}
return true;
}
if (strCommand == NetMsgType::GETADDR) {
// This asymmetric behavior for inbound and outbound connections was introduced
// to prevent a fingerprinting attack: an attacker can send specific fake addresses
// to users' AddrMan and later request them by sending getaddr messages.
// Making nodes which are behind NAT and can only make outgoing connections ignore
// the getaddr message mitigates the attack.
if (!pfrom->fInbound) {
LogPrint(BCLog::NET, "Ignoring \"getaddr\" from outbound connection. peer=%d\n", pfrom->GetId());
return true;
}
if (!pfrom->IsAddrRelayPeer()) {
LogPrint(BCLog::NET, "Ignoring \"getaddr\" from block-relay-only connection. peer=%d\n", pfrom->GetId());
return true;
}
// Only send one GetAddr response per connection to reduce resource waste
// and discourage addr stamping of INV announcements.
if (pfrom->fSentAddr) {
LogPrint(BCLog::NET, "Ignoring repeated \"getaddr\". peer=%d\n", pfrom->GetId());
return true;
}
pfrom->fSentAddr = true;
pfrom->vAddrToSend.clear();
std::vector<CAddress> vAddr = connman->GetAddresses();
FastRandomContext insecure_rand;
for (const CAddress &addr : vAddr) {
if (!banman->IsBanned(addr)) {
pfrom->PushAddress(addr, insecure_rand);
}
}
return true;
}
if (strCommand == NetMsgType::MEMPOOL) {
if (!(pfrom->GetLocalServices() & NODE_BLOOM) && !pfrom->HasPermission(PF_MEMPOOL))
{
if (!pfrom->HasPermission(PF_NOBAN))
{
LogPrint(BCLog::NET, "mempool request with bloom filters disabled, disconnect peer=%d\n", pfrom->GetId());
pfrom->fDisconnect = true;
}
return true;
}
if (connman->OutboundTargetReached(false) && !pfrom->HasPermission(PF_MEMPOOL))
{
if (!pfrom->HasPermission(PF_NOBAN))
{
LogPrint(BCLog::NET, "mempool request with bandwidth limit reached, disconnect peer=%d\n", pfrom->GetId());
pfrom->fDisconnect = true;
}
return true;
}
if (pfrom->m_tx_relay != nullptr) {
LOCK(pfrom->m_tx_relay->cs_tx_inventory);
pfrom->m_tx_relay->fSendMempool = true;
}
return true;
}
if (strCommand == NetMsgType::PING) {
if (pfrom->nVersion > BIP0031_VERSION)
{
uint64_t nonce = 0;
vRecv >> nonce;
// Echo the message back with the nonce. This allows for two useful features:
//
// 1) A remote node can quickly check if the connection is operational
// 2) Remote nodes can measure the latency of the network thread. If this node
// is overloaded it won't respond to pings quickly and the remote node can
// avoid sending us more work, like chain download requests.
//
// The nonce stops the remote getting confused between different pings: without
// it, if the remote node sends a ping once per second and this node takes 5
// seconds to respond to each, the 5th ping the remote sends would appear to
// return very quickly.
connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::PONG, nonce));
}
return true;
}
if (strCommand == NetMsgType::PONG) {
int64_t pingUsecEnd = nTimeReceived;
uint64_t nonce = 0;
size_t nAvail = vRecv.in_avail();
bool bPingFinished = false;
std::string sProblem;
if (nAvail >= sizeof(nonce)) {
vRecv >> nonce;
// Only process pong message if there is an outstanding ping (old ping without nonce should never pong)
if (pfrom->nPingNonceSent != 0) {
if (nonce == pfrom->nPingNonceSent) {
// Matching pong received, this ping is no longer outstanding
bPingFinished = true;
int64_t pingUsecTime = pingUsecEnd - pfrom->nPingUsecStart;
if (pingUsecTime > 0) {
// Successful ping time measurement, replace previous
pfrom->nPingUsecTime = pingUsecTime;
pfrom->nMinPingUsecTime = std::min(pfrom->nMinPingUsecTime.load(), pingUsecTime);
} else {
// This should never happen
sProblem = "Timing mishap";
}
} else {
// Nonce mismatches are normal when pings are overlapping
sProblem = "Nonce mismatch";
if (nonce == 0) {
// This is most likely a bug in another implementation somewhere; cancel this ping
bPingFinished = true;
sProblem = "Nonce zero";
}
}
} else {
sProblem = "Unsolicited pong without ping";
}
} else {
// This is most likely a bug in another implementation somewhere; cancel this ping
bPingFinished = true;
sProblem = "Short payload";
}
if (!(sProblem.empty())) {
LogPrint(BCLog::NET, "pong peer=%d: %s, %x expected, %x received, %u bytes\n",
pfrom->GetId(),
sProblem,
pfrom->nPingNonceSent,
nonce,
nAvail);
}
if (bPingFinished) {
pfrom->nPingNonceSent = 0;
}
return true;
}
if (strCommand == NetMsgType::FILTERLOAD) {
CBloomFilter filter;
vRecv >> filter;
if (!filter.IsWithinSizeConstraints())
{
// There is no excuse for sending a too-large filter
LOCK(cs_main);
Misbehaving(pfrom->GetId(), 100);
}
else if (pfrom->m_tx_relay != nullptr)
{
LOCK(pfrom->m_tx_relay->cs_filter);
pfrom->m_tx_relay->pfilter.reset(new CBloomFilter(filter));
pfrom->m_tx_relay->pfilter->UpdateEmptyFull();
pfrom->m_tx_relay->fRelayTxes = true;
}
return true;
}
if (strCommand == NetMsgType::FILTERADD) {
std::vector<unsigned char> vData;
vRecv >> vData;
// Nodes must NEVER send a data item > 520 bytes (the max size for a script data object,
// and thus, the maximum size any matched object can have) in a filteradd message
bool bad = false;
if (vData.size() > MAX_SCRIPT_ELEMENT_SIZE) {
bad = true;
} else if (pfrom->m_tx_relay != nullptr) {
LOCK(pfrom->m_tx_relay->cs_filter);
if (pfrom->m_tx_relay->pfilter) {
pfrom->m_tx_relay->pfilter->insert(vData);
} else {
bad = true;
}
}
if (bad) {
LOCK(cs_main);
Misbehaving(pfrom->GetId(), 100);
}
return true;
}
if (strCommand == NetMsgType::FILTERCLEAR) {
if (pfrom->m_tx_relay == nullptr) {
return true;
}
LOCK(pfrom->m_tx_relay->cs_filter);
if (pfrom->GetLocalServices() & NODE_BLOOM) {
pfrom->m_tx_relay->pfilter.reset(new CBloomFilter());
}
pfrom->m_tx_relay->fRelayTxes = true;
return true;
}
if (strCommand == NetMsgType::FEEFILTER) {
CAmount newFeeFilter = 0;
vRecv >> newFeeFilter;
if (MoneyRange(newFeeFilter)) {
if (pfrom->m_tx_relay != nullptr) {
LOCK(pfrom->m_tx_relay->cs_feeFilter);
pfrom->m_tx_relay->minFeeFilter = newFeeFilter;
}
LogPrint(BCLog::NET, "received: feefilter of %s from peer=%d\n", CFeeRate(newFeeFilter).ToString(), pfrom->GetId());
}
return true;
}
if (strCommand == NetMsgType::NOTFOUND) {
// Remove the NOTFOUND transactions from the peer
LOCK(cs_main);
CNodeState *state = State(pfrom->GetId());
std::vector<CInv> vInv;
vRecv >> vInv;
if (vInv.size() <= MAX_PEER_TX_IN_FLIGHT + MAX_BLOCKS_IN_TRANSIT_PER_PEER) {
for (CInv &inv : vInv) {
if (inv.type == MSG_TX || inv.type == MSG_WITNESS_TX) {
// If we receive a NOTFOUND message for a txid we requested, erase
// it from our data structures for this peer.
auto in_flight_it = state->m_tx_download.m_tx_in_flight.find(inv.hash);
if (in_flight_it == state->m_tx_download.m_tx_in_flight.end()) {
// Skip any further work if this is a spurious NOTFOUND
// message.
continue;
}
state->m_tx_download.m_tx_in_flight.erase(in_flight_it);
state->m_tx_download.m_tx_announced.erase(inv.hash);
}
}
}
return true;
}
// Ignore unknown commands for extensibility
LogPrint(BCLog::NET, "Unknown command \"%s\" from peer=%d\n", SanitizeString(strCommand), pfrom->GetId());
return true;
}
bool PeerLogicValidation::CheckIfBanned(CNode* pnode)
{
AssertLockHeld(cs_main);
CNodeState &state = *State(pnode->GetId());
if (state.fShouldBan) {
state.fShouldBan = false;
if (pnode->HasPermission(PF_NOBAN))
LogPrintf("Warning: not punishing whitelisted peer %s!\n", pnode->addr.ToString());
else if (pnode->m_manual_connection)
LogPrintf("Warning: not punishing manually-connected peer %s!\n", pnode->addr.ToString());
else if (pnode->addr.IsLocal()) {
// Disconnect but don't ban _this_ local node
LogPrintf("Warning: disconnecting but not banning local peer %s!\n", pnode->addr.ToString());
pnode->fDisconnect = true;
} else {
// Disconnect and ban all nodes sharing the address
if (m_banman) {
m_banman->Ban(pnode->addr, BanReasonNodeMisbehaving);
}
connman->DisconnectNode(pnode->addr);
}
return true;
}
return false;
}
bool PeerLogicValidation::ProcessMessages(CNode* pfrom, std::atomic<bool>& interruptMsgProc)
{
const CChainParams& chainparams = Params();
//
// Message format
// (4) message start
// (12) command
// (4) size
// (4) checksum
// (x) data
//
bool fMoreWork = false;
if (!pfrom->vRecvGetData.empty())
ProcessGetData(pfrom, chainparams, connman, m_mempool, interruptMsgProc);
if (!pfrom->orphan_work_set.empty()) {
std::list<CTransactionRef> removed_txn;
LOCK2(cs_main, g_cs_orphans);
ProcessOrphanTx(connman, m_mempool, pfrom->orphan_work_set, removed_txn);
for (const CTransactionRef& removedTx : removed_txn) {
AddToCompactExtraTransactions(removedTx);
}
}
if (pfrom->fDisconnect)
return false;
// this maintains the order of responses
// and prevents vRecvGetData to grow unbounded
if (!pfrom->vRecvGetData.empty()) return true;
if (!pfrom->orphan_work_set.empty()) return true;
// Don't bother if send buffer is too full to respond anyway
if (pfrom->fPauseSend)
return false;
std::list<CNetMessage> msgs;
{
LOCK(pfrom->cs_vProcessMsg);
if (pfrom->vProcessMsg.empty())
return false;
// Just take one message
msgs.splice(msgs.begin(), pfrom->vProcessMsg, pfrom->vProcessMsg.begin());
pfrom->nProcessQueueSize -= msgs.front().m_raw_message_size;
pfrom->fPauseRecv = pfrom->nProcessQueueSize > connman->GetReceiveFloodSize();
fMoreWork = !pfrom->vProcessMsg.empty();
}
CNetMessage& msg(msgs.front());
msg.SetVersion(pfrom->GetRecvVersion());
// Check network magic
if (!msg.m_valid_netmagic) {
LogPrint(BCLog::NET, "PROCESSMESSAGE: INVALID MESSAGESTART %s peer=%d\n", SanitizeString(msg.m_command), pfrom->GetId());
pfrom->fDisconnect = true;
return false;
}
// Check header
if (!msg.m_valid_header)
{
LogPrint(BCLog::NET, "PROCESSMESSAGE: ERRORS IN HEADER %s peer=%d\n", SanitizeString(msg.m_command), pfrom->GetId());
return fMoreWork;
}
const std::string& strCommand = msg.m_command;
// Message size
unsigned int nMessageSize = msg.m_message_size;
// Checksum
CDataStream& vRecv = msg.m_recv;
if (!msg.m_valid_checksum)
{
LogPrint(BCLog::NET, "%s(%s, %u bytes): CHECKSUM ERROR peer=%d\n", __func__,
SanitizeString(strCommand), nMessageSize, pfrom->GetId());
return fMoreWork;
}
// Process message
bool fRet = false;
try
{
fRet = ProcessMessage(pfrom, strCommand, vRecv, msg.m_time, chainparams, m_mempool, connman, m_banman, interruptMsgProc);
if (interruptMsgProc)
return false;
if (!pfrom->vRecvGetData.empty())
fMoreWork = true;
} catch (const std::exception& e) {
LogPrint(BCLog::NET, "%s(%s, %u bytes): Exception '%s' (%s) caught\n", __func__, SanitizeString(strCommand), nMessageSize, e.what(), typeid(e).name());
} catch (...) {
LogPrint(BCLog::NET, "%s(%s, %u bytes): Unknown exception caught\n", __func__, SanitizeString(strCommand), nMessageSize);
}
if (!fRet) {
LogPrint(BCLog::NET, "%s(%s, %u bytes) FAILED peer=%d\n", __func__, SanitizeString(strCommand), nMessageSize, pfrom->GetId());
}
LOCK(cs_main);
CheckIfBanned(pfrom);
return fMoreWork;
}
void PeerLogicValidation::ConsiderEviction(CNode *pto, int64_t time_in_seconds)
{
AssertLockHeld(cs_main);
CNodeState &state = *State(pto->GetId());
const CNetMsgMaker msgMaker(pto->GetSendVersion());
if (!state.m_chain_sync.m_protect && IsOutboundDisconnectionCandidate(pto) && state.fSyncStarted) {
// This is an outbound peer subject to disconnection if they don't
// announce a block with as much work as the current tip within
// CHAIN_SYNC_TIMEOUT + HEADERS_RESPONSE_TIME seconds (note: if
// their chain has more work than ours, we should sync to it,
// unless it's invalid, in which case we should find that out and
// disconnect from them elsewhere).
if (state.pindexBestKnownBlock != nullptr && state.pindexBestKnownBlock->nChainWork >= ::ChainActive().Tip()->nChainWork) {
if (state.m_chain_sync.m_timeout != 0) {
state.m_chain_sync.m_timeout = 0;
state.m_chain_sync.m_work_header = nullptr;
state.m_chain_sync.m_sent_getheaders = false;
}
} else if (state.m_chain_sync.m_timeout == 0 || (state.m_chain_sync.m_work_header != nullptr && state.pindexBestKnownBlock != nullptr && state.pindexBestKnownBlock->nChainWork >= state.m_chain_sync.m_work_header->nChainWork)) {
// Our best block known by this peer is behind our tip, and we're either noticing
// that for the first time, OR this peer was able to catch up to some earlier point
// where we checked against our tip.
// Either way, set a new timeout based on current tip.
state.m_chain_sync.m_timeout = time_in_seconds + CHAIN_SYNC_TIMEOUT;
state.m_chain_sync.m_work_header = ::ChainActive().Tip();
state.m_chain_sync.m_sent_getheaders = false;
} else if (state.m_chain_sync.m_timeout > 0 && time_in_seconds > state.m_chain_sync.m_timeout) {
// No evidence yet that our peer has synced to a chain with work equal to that
// of our tip, when we first detected it was behind. Send a single getheaders
// message to give the peer a chance to update us.
if (state.m_chain_sync.m_sent_getheaders) {
// They've run out of time to catch up!
LogPrintf("Disconnecting outbound peer %d for old chain, best known block = %s\n", pto->GetId(), state.pindexBestKnownBlock != nullptr ? state.pindexBestKnownBlock->GetBlockHash().ToString() : "<none>");
pto->fDisconnect = true;
} else {
assert(state.m_chain_sync.m_work_header);
LogPrint(BCLog::NET, "sending getheaders to outbound peer=%d to verify chain work (current best known block:%s, benchmark blockhash: %s)\n", pto->GetId(), state.pindexBestKnownBlock != nullptr ? state.pindexBestKnownBlock->GetBlockHash().ToString() : "<none>", state.m_chain_sync.m_work_header->GetBlockHash().ToString());
connman->PushMessage(pto, msgMaker.Make(NetMsgType::GETHEADERS, ::ChainActive().GetLocator(state.m_chain_sync.m_work_header->pprev), uint256()));
state.m_chain_sync.m_sent_getheaders = true;
constexpr int64_t HEADERS_RESPONSE_TIME = 120; // 2 minutes
// Bump the timeout to allow a response, which could clear the timeout
// (if the response shows the peer has synced), reset the timeout (if
// the peer syncs to the required work but not to our tip), or result
// in disconnect (if we advance to the timeout and pindexBestKnownBlock
// has not sufficiently progressed)
state.m_chain_sync.m_timeout = time_in_seconds + HEADERS_RESPONSE_TIME;
}
}
}
}
void PeerLogicValidation::EvictExtraOutboundPeers(int64_t time_in_seconds)
{
// Check whether we have too many outbound peers
int extra_peers = connman->GetExtraOutboundCount();
if (extra_peers > 0) {
// If we have more outbound peers than we target, disconnect one.
// Pick the outbound peer that least recently announced
// us a new block, with ties broken by choosing the more recent
// connection (higher node id)
NodeId worst_peer = -1;
int64_t oldest_block_announcement = std::numeric_limits<int64_t>::max();
connman->ForEachNode([&](CNode* pnode) {
AssertLockHeld(cs_main);
// Ignore non-outbound peers, or nodes marked for disconnect already
if (!IsOutboundDisconnectionCandidate(pnode) || pnode->fDisconnect) return;
CNodeState *state = State(pnode->GetId());
if (state == nullptr) return; // shouldn't be possible, but just in case
// Don't evict our protected peers
if (state->m_chain_sync.m_protect) return;
// Don't evict our block-relay-only peers.
if (pnode->m_tx_relay == nullptr) return;
if (state->m_last_block_announcement < oldest_block_announcement || (state->m_last_block_announcement == oldest_block_announcement && pnode->GetId() > worst_peer)) {
worst_peer = pnode->GetId();
oldest_block_announcement = state->m_last_block_announcement;
}
});
if (worst_peer != -1) {
bool disconnected = connman->ForNode(worst_peer, [&](CNode *pnode) {
AssertLockHeld(cs_main);
// Only disconnect a peer that has been connected to us for
// some reasonable fraction of our check-frequency, to give
// it time for new information to have arrived.
// Also don't disconnect any peer we're trying to download a
// block from.
CNodeState &state = *State(pnode->GetId());
if (time_in_seconds - pnode->nTimeConnected > MINIMUM_CONNECT_TIME && state.nBlocksInFlight == 0) {
LogPrint(BCLog::NET, "disconnecting extra outbound peer=%d (last block announcement received at time %d)\n", pnode->GetId(), oldest_block_announcement);
pnode->fDisconnect = true;
return true;
} else {
LogPrint(BCLog::NET, "keeping outbound peer=%d chosen for eviction (connect time: %d, blocks_in_flight: %d)\n", pnode->GetId(), pnode->nTimeConnected, state.nBlocksInFlight);
return false;
}
});
if (disconnected) {
// If we disconnected an extra peer, that means we successfully
// connected to at least one peer after the last time we
// detected a stale tip. Don't try any more extra peers until
// we next detect a stale tip, to limit the load we put on the
// network from these extra connections.
connman->SetTryNewOutboundPeer(false);
}
}
}
}
void PeerLogicValidation::CheckForStaleTipAndEvictPeers(const Consensus::Params &consensusParams)
{
LOCK(cs_main);
if (connman == nullptr) return;
int64_t time_in_seconds = GetTime();
EvictExtraOutboundPeers(time_in_seconds);
if (time_in_seconds > m_stale_tip_check_time) {
// Check whether our tip is stale, and if so, allow using an extra
// outbound peer
if (!fImporting && !fReindex && connman->GetNetworkActive() && connman->GetUseAddrmanOutgoing() && TipMayBeStale(consensusParams)) {
LogPrintf("Potential stale tip detected, will try using extra outbound peer (last tip update: %d seconds ago)\n", time_in_seconds - g_last_tip_update);
connman->SetTryNewOutboundPeer(true);
} else if (connman->GetTryNewOutboundPeer()) {
connman->SetTryNewOutboundPeer(false);
}
m_stale_tip_check_time = time_in_seconds + STALE_CHECK_INTERVAL;
}
}
namespace {
class CompareInvMempoolOrder
{
CTxMemPool *mp;
public:
explicit CompareInvMempoolOrder(CTxMemPool *_mempool)
{
mp = _mempool;
}
bool operator()(std::set<uint256>::iterator a, std::set<uint256>::iterator b)
{
/* As std::make_heap produces a max-heap, we want the entries with the
* fewest ancestors/highest fee to sort later. */
return mp->CompareDepthAndScore(*b, *a);
}
};
}
bool PeerLogicValidation::SendMessages(CNode* pto)
{
const Consensus::Params& consensusParams = Params().GetConsensus();
{
// Don't send anything until the version handshake is complete
if (!pto->fSuccessfullyConnected || pto->fDisconnect)
return true;
// If we get here, the outgoing message serialization version is set and can't change.
const CNetMsgMaker msgMaker(pto->GetSendVersion());
//
// Message: ping
//
bool pingSend = false;
if (pto->fPingQueued) {
// RPC ping request by user
pingSend = true;
}
if (pto->nPingNonceSent == 0 && pto->nPingUsecStart + PING_INTERVAL * 1000000 < GetTimeMicros()) {
// Ping automatically sent as a latency probe & keepalive.
pingSend = true;
}
if (pingSend) {
uint64_t nonce = 0;
while (nonce == 0) {
GetRandBytes((unsigned char*)&nonce, sizeof(nonce));
}
pto->fPingQueued = false;
pto->nPingUsecStart = GetTimeMicros();
if (pto->nVersion > BIP0031_VERSION) {
pto->nPingNonceSent = nonce;
connman->PushMessage(pto, msgMaker.Make(NetMsgType::PING, nonce));
} else {
// Peer is too old to support ping command with nonce, pong will never arrive.
pto->nPingNonceSent = 0;
connman->PushMessage(pto, msgMaker.Make(NetMsgType::PING));
}
}
TRY_LOCK(cs_main, lockMain);
if (!lockMain)
return true;
if (CheckIfBanned(pto)) return true;
CNodeState &state = *State(pto->GetId());
// Address refresh broadcast
int64_t nNow = GetTimeMicros();