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net_processing.cpp
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net_processing.cpp
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// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2016 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 "arith_uint256.h"
#include "blockencodings.h"
#include "chainparams.h"
#include "consensus/validation.h"
#include "hash.h"
#include "init.h"
#include "validation.h"
#include "merkleblock.h"
#include "net.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 "tinyformat.h"
#include "txmempool.h"
#include "ui_interface.h"
#include "util.h"
#include "utilmoneystr.h"
#include "utilstrencodings.h"
#include "validationinterface.h"
#include <boost/thread.hpp>
using namespace std;
#if defined(NDEBUG)
# error "Bitcoin cannot be compiled without assertions."
#endif
int64_t nTimeBestReceived = 0; // Used only to inform the wallet of when we last received a block
struct IteratorComparator
{
template<typename I>
bool operator()(const I& a, const I& b)
{
return &(*a) < &(*b);
}
};
struct COrphanTx {
// When modifying, adapt the copy of this definition in tests/DoS_tests.
CTransactionRef tx;
NodeId fromPeer;
int64_t nTimeExpire;
};
map<uint256, COrphanTx> mapOrphanTransactions GUARDED_BY(cs_main);
map<COutPoint, set<map<uint256, COrphanTx>::iterator, IteratorComparator>> mapOrphanTransactionsByPrev GUARDED_BY(cs_main);
void EraseOrphansFor(NodeId peer) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
static const uint64_t RANDOMIZER_ID_ADDRESS_RELAY = 0x3cac0035b5866b90ULL; // SHA256("main address relay")[0:8]
// Internal stuff
namespace {
/** Number of nodes with fSyncStarted. */
int nSyncStarted = 0;
/**
* Sources of received blocks, saved to be able to send them reject
* messages or ban them when processing happens afterwards. Protected by
* cs_main.
* Set mapBlockSource[hash].second to false if the node should not be
* punished if the block is invalid.
*/
map<uint256, std::pair<NodeId, bool>> mapBlockSource;
/**
* 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. Protected by
* cs_main.
*
* 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;
uint256 hashRecentRejectsChainTip;
/** Blocks that are in flight, and that are in the queue to be downloaded. Protected by cs_main. */
struct QueuedBlock {
uint256 hash;
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
};
map<uint256, pair<NodeId, list<QueuedBlock>::iterator> > mapBlocksInFlight;
/** Stack of nodes which we have set to announce using compact blocks */
list<NodeId> lNodesAnnouncingHeaderAndIDs;
/** Number of preferable block download peers. */
int nPreferredDownload = 0;
/** Number of peers from which we're downloading blocks. */
int nPeersWithValidatedDownloads = 0;
/** Relay map, protected by cs_main. */
typedef std::map<uint256, CTransactionRef> MapRelay;
MapRelay mapRelay;
/** Expiration-time ordered list of (expire time, relay map entry) pairs, protected by cs_main). */
std::deque<std::pair<int64_t, MapRelay::iterator>> vRelayExpiration;
} // anon namespace
//////////////////////////////////////////////////////////////////////////////
//
// Registration of network node signals.
//
namespace {
struct CBlockReject {
unsigned char chRejectCode;
string strRejectReason;
uint256 hashBlock;
};
/**
* 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;
//! List of asynchronously-determined block rejections to notify this peer about.
std::vector<CBlockReject> rejects;
//! The best known block we know this peer has announced.
CBlockIndex *pindexBestKnownBlock;
//! The hash of the last unknown block this peer has announced.
uint256 hashLastUnknownBlock;
//! The last full block we both have.
CBlockIndex *pindexLastCommonBlock;
//! The best header we have sent our peer.
CBlockIndex *pindexBestHeaderSent;
//! Length of current-streak of unconnecting headers announcements
int nUnconnectingHeaders;
//! Whether we've started headers synchronization with this peer.
bool fSyncStarted;
//! Since when we're stalling block download progress (in microseconds), or 0.
int64_t nStallingSince;
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;
CNodeState(CAddress addrIn, std::string addrNameIn) : address(addrIn), name(addrNameIn) {
fCurrentlyConnected = false;
nMisbehavior = 0;
fShouldBan = false;
pindexBestKnownBlock = NULL;
hashLastUnknownBlock.SetNull();
pindexLastCommonBlock = NULL;
pindexBestHeaderSent = NULL;
nUnconnectingHeaders = 0;
fSyncStarted = false;
nStallingSince = 0;
nDownloadingSince = 0;
nBlocksInFlight = 0;
nBlocksInFlightValidHeaders = 0;
fPreferredDownload = false;
fPreferHeaders = false;
fPreferHeaderAndIDs = false;
fProvidesHeaderAndIDs = false;
fHaveWitness = false;
fWantsCmpctWitness = false;
fSupportsDesiredCmpctVersion = false;
}
};
/** Map maintaining per-node state. Requires cs_main. */
map<NodeId, CNodeState> mapNodeState;
// Requires cs_main.
CNodeState *State(NodeId pnode) {
map<NodeId, CNodeState>::iterator it = mapNodeState.find(pnode);
if (it == mapNodeState.end())
return NULL;
return &it->second;
}
void UpdatePreferredDownload(CNode* node, CNodeState* state)
{
nPreferredDownload -= state->fPreferredDownload;
// Whether this node should be marked as a preferred download node.
state->fPreferredDownload = (!node->fInbound || node->fWhitelisted) && !node->fOneShot && !node->fClient;
nPreferredDownload += state->fPreferredDownload;
}
void PushNodeVersion(CNode *pnode, CConnman& connman, int64_t nTime)
{
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, ::fRelayTxes));
if (fLogIPs)
LogPrint("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("net", "send version message: version %d, blocks=%d, us=%s, peer=%d\n", PROTOCOL_VERSION, nNodeStartingHeight, addrMe.ToString(), nodeid);
}
void InitializeNode(CNode *pnode, CConnman& connman) {
CAddress addr = pnode->addr;
std::string addrName = pnode->addrName;
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)));
}
if(!pnode->fInbound)
PushNodeVersion(pnode, connman, GetTime());
}
void FinalizeNode(NodeId nodeid, bool& fUpdateConnectionTime) {
fUpdateConnectionTime = false;
LOCK(cs_main);
CNodeState *state = State(nodeid);
if (state->fSyncStarted)
nSyncStarted--;
if (state->nMisbehavior == 0 && state->fCurrentlyConnected) {
fUpdateConnectionTime = true;
}
BOOST_FOREACH(const QueuedBlock& entry, state->vBlocksInFlight) {
mapBlocksInFlight.erase(entry.hash);
}
EraseOrphansFor(nodeid);
nPreferredDownload -= state->fPreferredDownload;
nPeersWithValidatedDownloads -= (state->nBlocksInFlightValidHeaders != 0);
assert(nPeersWithValidatedDownloads >= 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);
}
}
// Requires cs_main.
// 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
bool MarkBlockAsReceived(const uint256& hash) {
map<uint256, pair<NodeId, list<QueuedBlock>::iterator> >::iterator itInFlight = mapBlocksInFlight.find(hash);
if (itInFlight != mapBlocksInFlight.end()) {
CNodeState *state = State(itInFlight->second.first);
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;
}
// Requires cs_main.
// returns false, still setting pit, if the block was already in flight from the same peer
// pit will only be valid as long as the same cs_main lock is being held
bool MarkBlockAsInFlight(NodeId nodeid, const uint256& hash, const Consensus::Params& consensusParams, CBlockIndex *pindex = NULL, list<QueuedBlock>::iterator **pit = NULL) {
CNodeState *state = State(nodeid);
assert(state != NULL);
// Short-circuit most stuff in case its from the same node
map<uint256, pair<NodeId, list<QueuedBlock>::iterator> >::iterator itInFlight = mapBlocksInFlight.find(hash);
if (itInFlight != mapBlocksInFlight.end() && itInFlight->second.first == nodeid) {
*pit = &itInFlight->second.second;
return false;
}
// Make sure it's not listed somewhere already.
MarkBlockAsReceived(hash);
list<QueuedBlock>::iterator it = state->vBlocksInFlight.insert(state->vBlocksInFlight.end(),
{hash, pindex, pindex != NULL, std::unique_ptr<PartiallyDownloadedBlock>(pit ? new PartiallyDownloadedBlock(&mempool) : NULL)});
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 != NULL) {
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. */
void ProcessBlockAvailability(NodeId nodeid) {
CNodeState *state = State(nodeid);
assert(state != NULL);
if (!state->hashLastUnknownBlock.IsNull()) {
BlockMap::iterator itOld = mapBlockIndex.find(state->hashLastUnknownBlock);
if (itOld != mapBlockIndex.end() && itOld->second->nChainWork > 0) {
if (state->pindexBestKnownBlock == NULL || itOld->second->nChainWork >= state->pindexBestKnownBlock->nChainWork)
state->pindexBestKnownBlock = itOld->second;
state->hashLastUnknownBlock.SetNull();
}
}
}
/** Update tracking information about which blocks a peer is assumed to have. */
void UpdateBlockAvailability(NodeId nodeid, const uint256 &hash) {
CNodeState *state = State(nodeid);
assert(state != NULL);
ProcessBlockAvailability(nodeid);
BlockMap::iterator it = mapBlockIndex.find(hash);
if (it != mapBlockIndex.end() && it->second->nChainWork > 0) {
// An actually better block was announced.
if (state->pindexBestKnownBlock == NULL || it->second->nChainWork >= state->pindexBestKnownBlock->nChainWork)
state->pindexBestKnownBlock = it->second;
} else {
// An unknown block was announced; just assume that the latest one is the best one.
state->hashLastUnknownBlock = hash;
}
}
void MaybeSetPeerAsAnnouncingHeaderAndIDs(const CNodeState* nodestate, CNode* pfrom, CConnman& connman) {
if (!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 == pfrom->GetId()) {
lNodesAnnouncingHeaderAndIDs.erase(it);
lNodesAnnouncingHeaderAndIDs.push_back(pfrom->GetId());
return;
}
}
bool fAnnounceUsingCMPCTBLOCK = false;
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, fAnnounceUsingCMPCTBLOCK, nCMPCTBLOCKVersion](CNode* pnodeStop){
connman.PushMessage(pnodeStop, CNetMsgMaker(pnodeStop->GetSendVersion()).Make(NetMsgType::SENDCMPCT, fAnnounceUsingCMPCTBLOCK, nCMPCTBLOCKVersion));
return true;
});
lNodesAnnouncingHeaderAndIDs.pop_front();
}
fAnnounceUsingCMPCTBLOCK = true;
connman.PushMessage(pfrom, CNetMsgMaker(pfrom->GetSendVersion()).Make(NetMsgType::SENDCMPCT, fAnnounceUsingCMPCTBLOCK, nCMPCTBLOCKVersion));
lNodesAnnouncingHeaderAndIDs.push_back(pfrom->GetId());
}
}
// Requires cs_main
bool CanDirectFetch(const Consensus::Params &consensusParams)
{
return chainActive.Tip()->GetBlockTime() > GetAdjustedTime() - consensusParams.nPowTargetSpacing * 20;
}
// Requires cs_main
bool PeerHasHeader(CNodeState *state, CBlockIndex *pindex)
{
if (state->pindexBestKnownBlock && pindex == state->pindexBestKnownBlock->GetAncestor(pindex->nHeight))
return true;
if (state->pindexBestHeaderSent && pindex == state->pindexBestHeaderSent->GetAncestor(pindex->nHeight))
return true;
return false;
}
/** Find the last common ancestor two blocks have.
* Both pa and pb must be non-NULL. */
CBlockIndex* LastCommonAncestor(CBlockIndex* pa, CBlockIndex* pb) {
if (pa->nHeight > pb->nHeight) {
pa = pa->GetAncestor(pb->nHeight);
} else if (pb->nHeight > pa->nHeight) {
pb = pb->GetAncestor(pa->nHeight);
}
while (pa != pb && pa && pb) {
pa = pa->pprev;
pb = pb->pprev;
}
// Eventually all chain branches meet at the genesis block.
assert(pa == pb);
return pa;
}
/** Update pindexLastCommonBlock and add not-in-flight missing successors to vBlocks, until it has
* at most count entries. */
void FindNextBlocksToDownload(NodeId nodeid, unsigned int count, std::vector<CBlockIndex*>& vBlocks, NodeId& nodeStaller, const Consensus::Params& consensusParams) {
if (count == 0)
return;
vBlocks.reserve(vBlocks.size() + count);
CNodeState *state = State(nodeid);
assert(state != NULL);
// Make sure pindexBestKnownBlock is up to date, we'll need it.
ProcessBlockAvailability(nodeid);
if (state->pindexBestKnownBlock == NULL || state->pindexBestKnownBlock->nChainWork < chainActive.Tip()->nChainWork) {
// This peer has nothing interesting.
return;
}
if (state->pindexLastCommonBlock == NULL) {
// 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<CBlockIndex*> vToFetch;
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 mean time, 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).
BOOST_FOREACH(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->nChainTx)
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;
}
}
}
}
} // anon namespace
bool GetNodeStateStats(NodeId nodeid, CNodeStateStats &stats) {
LOCK(cs_main);
CNodeState *state = State(nodeid);
if (state == NULL)
return false;
stats.nMisbehavior = state->nMisbehavior;
stats.nSyncHeight = state->pindexBestKnownBlock ? state->pindexBestKnownBlock->nHeight : -1;
stats.nCommonHeight = state->pindexLastCommonBlock ? state->pindexLastCommonBlock->nHeight : -1;
BOOST_FOREACH(const QueuedBlock& queue, state->vBlocksInFlight) {
if (queue.pindex)
stats.vHeightInFlight.push_back(queue.pindex->nHeight);
}
return true;
}
void RegisterNodeSignals(CNodeSignals& nodeSignals)
{
nodeSignals.ProcessMessages.connect(&ProcessMessages);
nodeSignals.SendMessages.connect(&SendMessages);
nodeSignals.InitializeNode.connect(&InitializeNode);
nodeSignals.FinalizeNode.connect(&FinalizeNode);
}
void UnregisterNodeSignals(CNodeSignals& nodeSignals)
{
nodeSignals.ProcessMessages.disconnect(&ProcessMessages);
nodeSignals.SendMessages.disconnect(&SendMessages);
nodeSignals.InitializeNode.disconnect(&InitializeNode);
nodeSignals.FinalizeNode.disconnect(&FinalizeNode);
}
//////////////////////////////////////////////////////////////////////////////
//
// mapOrphanTransactions
//
bool AddOrphanTx(const CTransactionRef& tx, NodeId peer) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
{
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 99,999 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("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});
assert(ret.second);
BOOST_FOREACH(const CTxIn& txin, tx->vin) {
mapOrphanTransactionsByPrev[txin.prevout].insert(ret.first);
}
LogPrint("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(cs_main)
{
map<uint256, COrphanTx>::iterator it = mapOrphanTransactions.find(hash);
if (it == mapOrphanTransactions.end())
return 0;
BOOST_FOREACH(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);
}
mapOrphanTransactions.erase(it);
return 1;
}
void EraseOrphansFor(NodeId peer)
{
int nErased = 0;
map<uint256, COrphanTx>::iterator iter = mapOrphanTransactions.begin();
while (iter != mapOrphanTransactions.end())
{
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("mempool", "Erased %d orphan tx from peer %d\n", nErased, peer);
}
unsigned int LimitOrphanTxSize(unsigned int nMaxOrphans) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
{
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;
map<uint256, COrphanTx>::iterator iter = mapOrphanTransactions.begin();
while (iter != mapOrphanTransactions.end())
{
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("mempool", "Erased %d orphan tx due to expiration\n", nErased);
}
while (mapOrphanTransactions.size() > nMaxOrphans)
{
// Evict a random orphan:
uint256 randomhash = GetRandHash();
map<uint256, COrphanTx>::iterator it = mapOrphanTransactions.lower_bound(randomhash);
if (it == mapOrphanTransactions.end())
it = mapOrphanTransactions.begin();
EraseOrphanTx(it->first);
++nEvicted;
}
return nEvicted;
}
// Requires cs_main.
void Misbehaving(NodeId pnode, int howmuch)
{
if (howmuch == 0)
return;
CNodeState *state = State(pnode);
if (state == NULL)
return;
state->nMisbehavior += howmuch;
int banscore = GetArg("-banscore", DEFAULT_BANSCORE_THRESHOLD);
if (state->nMisbehavior >= banscore && state->nMisbehavior - howmuch < banscore)
{
LogPrintf("%s: %s peer=%d (%d -> %d) BAN THRESHOLD EXCEEDED\n", __func__, state->name, pnode, state->nMisbehavior-howmuch, state->nMisbehavior);
state->fShouldBan = true;
} else
LogPrintf("%s: %s peer=%d (%d -> %d)\n", __func__, state->name, pnode, state->nMisbehavior-howmuch, state->nMisbehavior);
}
//////////////////////////////////////////////////////////////////////////////
//
// blockchain -> download logic notification
//
PeerLogicValidation::PeerLogicValidation(CConnman* connmanIn) : connman(connmanIn) {
// Initialize global variables that cannot be constructed at startup.
recentRejects.reset(new CRollingBloomFilter(120000, 0.000001));
}
void PeerLogicValidation::SyncTransaction(const CTransaction& tx, const CBlockIndex* pindex, int nPosInBlock) {
if (nPosInBlock == CMainSignals::SYNC_TRANSACTION_NOT_IN_BLOCK)
return;
LOCK(cs_main);
std::vector<uint256> vOrphanErase;
// Which orphan pool entries must we evict?
for (size_t j = 0; j < tx.vin.size(); j++) {
auto itByPrev = mapOrphanTransactionsByPrev.find(tx.vin[j].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 include or precluded by this block
if (vOrphanErase.size()) {
int nErased = 0;
BOOST_FOREACH(uint256 &orphanHash, vOrphanErase) {
nErased += EraseOrphanTx(orphanHash);
}
LogPrint("mempool", "Erased %d orphan tx included or conflicted by block\n", nErased);
}
}
void PeerLogicValidation::UpdatedBlockTip(const CBlockIndex *pindexNew, const CBlockIndex *pindexFork, bool fInitialDownload) {
const int nNewHeight = pindexNew->nHeight;
connman->SetBestHeight(nNewHeight);
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)) {
BOOST_REVERSE_FOREACH(const uint256& hash, vHashes) {
pnode->PushBlockHash(hash);
}
}
});
}
nTimeBestReceived = GetTime();
}
void PeerLogicValidation::BlockChecked(const CBlock& block, const CValidationState& state) {
LOCK(cs_main);
const uint256 hash(block.GetHash());
std::map<uint256, std::pair<NodeId, bool>>::iterator it = mapBlockSource.find(hash);
int nDoS = 0;
if (state.IsInvalid(nDoS)) {
if (it != mapBlockSource.end() && State(it->second.first)) {
assert (state.GetRejectCode() < REJECT_INTERNAL); // Blocks are never rejected with internal reject codes
CBlockReject reject = {(unsigned char)state.GetRejectCode(), state.GetRejectReason().substr(0, MAX_REJECT_MESSAGE_LENGTH), hash};
State(it->second.first)->rejects.push_back(reject);
if (nDoS > 0 && it->second.second)
Misbehaving(it->second.first, nDoS);
}
}
if (it != mapBlockSource.end())
mapBlockSource.erase(it);
}
//////////////////////////////////////////////////////////////////////////////
//
// Messages
//
bool static AlreadyHave(const CInv& inv) 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();
}
// Use pcoinsTip->HaveCoinsInCache as a quick approximation to exclude
// requesting or processing some txs which have already been included in a block
return recentRejects->contains(inv.hash) ||
mempool.exists(inv.hash) ||
mapOrphanTransactions.count(inv.hash) ||
pcoinsTip->HaveCoinsInCache(inv.hash);
}
case MSG_BLOCK:
case MSG_WITNESS_BLOCK:
return mapBlockIndex.count(inv.hash);
}
// Don't know what it is, just say we already got one
return true;
}
static void RelayTransaction(const CTransaction& tx, CConnman& connman)
{
CInv inv(MSG_TX, tx.GetHash());
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 addrKnowns 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) {
uint64_t hashKey = CSipHasher(hasher).Write(pnode->id).Finalize();
for (unsigned int i = 0; i < nRelayNodes; i++) {
if (hashKey > best[i].first) {
std::copy(best.begin() + i, best.begin() + nRelayNodes - 1, best.begin() + i + 1);
best[i] = std::make_pair(hashKey, 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 ProcessGetData(CNode* pfrom, const Consensus::Params& consensusParams, CConnman& connman)
{
std::deque<CInv>::iterator it = pfrom->vRecvGetData.begin();
unsigned int nMaxSendBufferSize = connman.GetSendBufferSize();
vector<CInv> vNotFound;
CNetMsgMaker msgMaker(pfrom->GetSendVersion());
LOCK(cs_main);
while (it != pfrom->vRecvGetData.end()) {
// Don't bother if send buffer is too full to respond anyway
if (pfrom->nSendSize >= nMaxSendBufferSize)
break;
const CInv &inv = *it;
{
boost::this_thread::interruption_point();
it++;
if (inv.type == MSG_BLOCK || inv.type == MSG_FILTERED_BLOCK || inv.type == MSG_CMPCT_BLOCK || inv.type == MSG_WITNESS_BLOCK)
{
bool send = false;
BlockMap::iterator mi = mapBlockIndex.find(inv.hash);
if (mi != mapBlockIndex.end())
{
if (chainActive.Contains(mi->second)) {
send = true;
} else {
static const int nOneMonth = 30 * 24 * 60 * 60;
// To prevent fingerprinting attacks, only send blocks outside of the active
// chain if they are valid, and no more than a month older (both in time, and in
// best equivalent proof of work) than the best header chain we know about.
send = mi->second->IsValid(BLOCK_VALID_SCRIPTS) && (pindexBestHeader != NULL) &&
(pindexBestHeader->GetBlockTime() - mi->second->GetBlockTime() < nOneMonth) &&
(GetBlockProofEquivalentTime(*pindexBestHeader, *mi->second, *pindexBestHeader, consensusParams) < nOneMonth);
if (!send) {
LogPrintf("%s: ignoring request from peer=%i for old block that isn't in the main chain\n", __func__, pfrom->GetId());
}
}
}
// disconnect node in case we have reached the outbound limit for serving historical blocks
// never disconnect whitelisted nodes
static const int nOneWeek = 7 * 24 * 60 * 60; // assume > 1 week = historical
if (send && connman.OutboundTargetReached(true) && ( ((pindexBestHeader != NULL) && (pindexBestHeader->GetBlockTime() - mi->second->GetBlockTime() > nOneWeek)) || inv.type == MSG_FILTERED_BLOCK) && !pfrom->fWhitelisted)
{
LogPrint("net", "historical block serving limit reached, disconnect peer=%d\n", pfrom->GetId());
//disconnect node
pfrom->fDisconnect = true;
send = false;
}
// Pruned nodes may have deleted the block, so check whether
// it's available before trying to send.
if (send && (mi->second->nStatus & BLOCK_HAVE_DATA))
{
// Send block from disk
CBlock block;
if (!ReadBlockFromDisk(block, (*mi).second, consensusParams))
assert(!"cannot load block from disk");
if (inv.type == MSG_BLOCK)
connman.PushMessage(pfrom, msgMaker.Make(SERIALIZE_TRANSACTION_NO_WITNESS, NetMsgType::BLOCK, block));
else if (inv.type == MSG_WITNESS_BLOCK)
connman.PushMessage(pfrom, msgMaker.Make(NetMsgType::BLOCK, block));
else if (inv.type == MSG_FILTERED_BLOCK)
{
bool sendMerkleBlock = false;
CMerkleBlock merkleBlock;
{
LOCK(pfrom->cs_filter);
if (pfrom->pfilter) {
sendMerkleBlock = true;
merkleBlock = CMerkleBlock(block, *pfrom->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;
BOOST_FOREACH(PairType& pair, merkleBlock.vMatchedTxn)
connman.PushMessage(pfrom, msgMaker.Make(SERIALIZE_TRANSACTION_NO_WITNESS, NetMsgType::TX, *block.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) && mi->second->nHeight >= chainActive.Height() - MAX_CMPCTBLOCK_DEPTH) {
CBlockHeaderAndShortTxIDs cmpctblock(block, fPeerWantsWitness);
connman.PushMessage(pfrom, msgMaker.Make(nSendFlags, NetMsgType::CMPCTBLOCK, cmpctblock));
} else
connman.PushMessage(pfrom, msgMaker.Make(nSendFlags, NetMsgType::BLOCK, block));
}
// 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.
vector<CInv> vInv;
vInv.push_back(CInv(MSG_BLOCK, chainActive.Tip()->GetBlockHash()));
connman.PushMessage(pfrom, msgMaker.Make(NetMsgType::INV, vInv));