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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 "reverse_iterator.h"
#include "tinyformat.h"
#include "txmempool.h"
#include "ui_interface.h"
#include "util.h"
#include "utilmoneystr.h"
#include "utilstrencodings.h"
#include "validationinterface.h"
#if defined(NDEBUG)
# error "Bitcoin cannot be compiled without assertions."
#endif
std::atomic<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;
};
std::map<uint256, COrphanTx> mapOrphanTransactions GUARDED_BY(cs_main);
std::map<COutPoint, std::set<std::map<uint256, COrphanTx>::iterator, IteratorComparator>> mapOrphanTransactionsByPrev GUARDED_BY(cs_main);
void EraseOrphansFor(NodeId peer) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
static size_t vExtraTxnForCompactIt = 0;
static std::vector<std::pair<uint256, CTransactionRef>> vExtraTxnForCompact GUARDED_BY(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.
*/
std::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;
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;
/** Stack of nodes which we have set to announce using compact blocks */
std::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;
} // namespace
namespace {
struct CBlockReject {
unsigned char chRejectCode;
std::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.
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;
CNodeState(CAddress addrIn, std::string addrNameIn) : address(addrIn), name(addrNameIn) {
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;
}
};
/** Map maintaining per-node state. Requires cs_main. */
std::map<NodeId, CNodeState> mapNodeState;
// Requires cs_main.
CNodeState *State(NodeId pnode) {
std::map<NodeId, CNodeState>::iterator it = mapNodeState.find(pnode);
if (it == mapNodeState.end())
return nullptr;
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(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);
}
}
// 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) {
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);
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 CBlockIndex* pindex = nullptr, std::list<QueuedBlock>::iterator** pit = nullptr) {
CNodeState *state = State(nodeid);
assert(state != nullptr);
// Short-circuit most stuff in case its 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. */
void ProcessBlockAvailability(NodeId nodeid) {
CNodeState *state = State(nodeid);
assert(state != nullptr);
if (!state->hashLastUnknownBlock.IsNull()) {
BlockMap::iterator itOld = mapBlockIndex.find(state->hashLastUnknownBlock);
if (itOld != mapBlockIndex.end() && itOld->second->nChainWork > 0) {
if (state->pindexBestKnownBlock == nullptr || 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 != nullptr);
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 == nullptr || 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(NodeId nodeid, CConnman* connman) {
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){
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());
return true;
});
}
}
// Requires cs_main
bool CanDirectFetch(const Consensus::Params &consensusParams)
{
return chainActive.Tip()->GetBlockTime() > GetAdjustedTime() - consensusParams.nPowTargetSpacing * 20;
}
// Requires cs_main
bool PeerHasHeader(CNodeState *state, const 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;
}
/** 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<const CBlockIndex*>& vBlocks, NodeId& nodeStaller, const Consensus::Params& consensusParams) {
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 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).
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->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;
}
}
}
}
} // namespace
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)));
}
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);
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);
}
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
//
void AddToCompactExtraTransactions(const CTransactionRef& tx)
{
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(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(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});
assert(ret.second);
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(cs_main)
{
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);
}
mapOrphanTransactions.erase(it);
return 1;
}
void EraseOrphansFor(NodeId peer)
{
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) 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;
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);
}
while (mapOrphanTransactions.size() > nMaxOrphans)
{
// Evict a random orphan:
uint256 randomhash = GetRandHash();
std::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 == nullptr)
return;
state->nMisbehavior += howmuch;
int banscore = gArgs.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::BlockConnected(const std::shared_ptr<const CBlock>& pblock, const CBlockIndex* pindex, const std::vector<CTransactionRef>& vtxConflicted) {
LOCK(cs_main);
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 include or precluded by this block
if (vOrphanErase.size()) {
int nErased = 0;
for (uint256 &orphanHash : vOrphanErase) {
nErased += EraseOrphanTx(orphanHash);
}
LogPrint(BCLog::MEMPOOL, "Erased %d orphan tx included or conflicted by block\n", nErased);
}
}
// All of the following cache a recent block, and are protected by cs_most_recent_block
static CCriticalSection cs_most_recent_block;
static std::shared_ptr<const CBlock> most_recent_block;
static std::shared_ptr<const CBlockHeaderAndShortTxIDs> most_recent_compact_block;
static uint256 most_recent_block_hash;
static bool fWitnessesPresentInMostRecentCompactBlock;
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) {
// 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;
}
});
}
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)) {
for (const uint256& hash : reverse_iterate(vHashes)) {
pnode->PushBlockHash(hash);
}
}
});
connman->WakeMessageHandler();
}
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)) {
// Don't send reject message with code 0 or an internal reject code.
if (it != mapBlockSource.end() && State(it->second.first) && state.GetRejectCode() > 0 && state.GetRejectCode() < REJECT_INTERNAL) {
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);
}
}
// 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() &&
!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) 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();
}
return recentRejects->contains(inv.hash) ||
mempool.exists(inv.hash) ||
mapOrphanTransactions.count(inv.hash) ||
pcoinsTip->HaveCoinInCache(COutPoint(inv.hash, 0)) || // Best effort: only try output 0 and 1
pcoinsTip->HaveCoinInCache(COutPoint(inv.hash, 1));
}
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->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 ProcessGetData(CNode* pfrom, const Consensus::Params& consensusParams, CConnman* connman, const std::atomic<bool>& interruptMsgProc)
{
std::deque<CInv>::iterator it = pfrom->vRecvGetData.begin();
std::vector<CInv> vNotFound;
const 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->fPauseSend)
break;
const CInv &inv = *it;
{
if (interruptMsgProc)
return;
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);
std::shared_ptr<const CBlock> a_recent_block;
std::shared_ptr<const CBlockHeaderAndShortTxIDs> a_recent_compact_block;
bool fWitnessesPresentInARecentCompactBlock;
{
LOCK(cs_most_recent_block);
a_recent_block = most_recent_block;
a_recent_compact_block = most_recent_compact_block;
fWitnessesPresentInARecentCompactBlock = fWitnessesPresentInMostRecentCompactBlock;
}
if (mi != mapBlockIndex.end())
{
if (mi->second->nChainTx && !mi->second->IsValid(BLOCK_VALID_SCRIPTS) &&
mi->second->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.
CValidationState dummy;
ActivateBestChain(dummy, Params(), a_recent_block);
}
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 != nullptr) &&
(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 != nullptr) && (pindexBestHeader->GetBlockTime() - mi->second->GetBlockTime() > nOneWeek)) || inv.type == MSG_FILTERED_BLOCK) && !pfrom->fWhitelisted)
{
LogPrint(BCLog::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))
{
std::shared_ptr<const CBlock> pblock;
if (a_recent_block && a_recent_block->GetHash() == (*mi).second->GetBlockHash()) {
pblock = a_recent_block;
} else {
// Send block from disk
std::shared_ptr<CBlock> pblockRead = std::make_shared<CBlock>();
if (!ReadBlockFromDisk(*pblockRead, (*mi).second, consensusParams))
assert(!"cannot load block from disk");
pblock = pblockRead;
}
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;
{
LOCK(pfrom->cs_filter);
if (pfrom->pfilter) {
sendMerkleBlock = true;
merkleBlock = CMerkleBlock(*pblock, *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;
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) && mi->second->nHeight >= chainActive.Height() - MAX_CMPCTBLOCK_DEPTH) {
if ((fPeerWantsWitness || !fWitnessesPresentInARecentCompactBlock) && a_recent_compact_block && a_recent_compact_block->header.GetHash() == mi->second->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();
}
}
}
else if (inv.type == MSG_TX || inv.type == MSG_WITNESS_TX)
{
// 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 if (pfrom->timeLastMempoolReq) {
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.
if (txinfo.tx && txinfo.nTime <= pfrom->timeLastMempoolReq) {
connman->PushMessage(pfrom, msgMaker.Make(nSendFlags, NetMsgType::TX, *txinfo.tx));
push = true;
}
}
if (!push) {
vNotFound.push_back(inv);
}
}
// Track requests for our stuff.
GetMainSignals().Inventory(inv.hash);
if (inv.type == MSG_BLOCK || inv.type == MSG_FILTERED_BLOCK || inv.type == MSG_CMPCT_BLOCK || inv.type == MSG_WITNESS_BLOCK)
break;
}
}
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. Currently only SPV clients actually 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.
connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::NOTFOUND, vNotFound));
}
}
uint32_t GetFetchFlags(CNode* pfrom) {
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);
LogPrintf("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 ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStream& vRecv, int64_t nTimeReceived, const CChainParams& chainparams, CConnman* connman, 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::REJECT)
{
if (LogAcceptCategory(BCLog::NET)) {
try {
std::string strMsg; unsigned char ccode; std::string strReason;
vRecv >> LIMITED_STRING(strMsg, CMessageHeader::COMMAND_SIZE) >> ccode >> LIMITED_STRING(strReason, MAX_REJECT_MESSAGE_LENGTH);
std::ostringstream ss;
ss << strMsg << " code " << itostr(ccode) << ": " << strReason;
if (strMsg == NetMsgType::BLOCK || strMsg == NetMsgType::TX)
{
uint256 hash;
vRecv >> hash;
ss << ": hash " << hash.ToString();
}
LogPrint(BCLog::NET, "Reject %s\n", SanitizeString(ss.str()));
} catch (const std::ios_base::failure&) {
// Avoid feedback loops by preventing reject messages from triggering a new reject message.
LogPrint(BCLog::NET, "Unparseable reject message received\n");
}
}
}
else if (strCommand == NetMsgType::VERSION)
{
// Each connection can only send one version message
if (pfrom->nVersion != 0)
{
connman->PushMessage(pfrom, CNetMsgMaker(INIT_PROTO_VERSION).Make(NetMsgType::REJECT, strCommand, REJECT_DUPLICATE, std::string("Duplicate version message")));
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 strSubVer;
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->nServicesExpected & ~nServices)
{
LogPrint(BCLog::NET, "peer=%d does not offer the expected services (%08x offered, %08x expected); disconnecting\n", pfrom->GetId(), nServices, pfrom->nServicesExpected);
connman->PushMessage(pfrom, CNetMsgMaker(INIT_PROTO_VERSION).Make(NetMsgType::REJECT, strCommand, REJECT_NONSTANDARD,
strprintf("Expected to offer services %08x", pfrom->nServicesExpected)));
pfrom->fDisconnect = true;
return false;
}
if (nServices & ((1 << 7) | (1 << 5))) {
if (GetTime() < 1533096000) {
// Immediately disconnect peers that use service bits 6 or 8 until August 1st, 2018
// These bits have been used as a flag to indicate that a node is running incompatible
// consensus rules instead of changing the network magic, so we're stuck disconnecting
// based on these service bits, at least for a while.
pfrom->fDisconnect = true;
return false;
}
}
if (nVersion < MIN_PEER_PROTO_VERSION)
{
// disconnect from peers older than this proto version
LogPrintf("peer=%d using obsolete version %i; disconnecting\n", pfrom->GetId(), nVersion);
connman->PushMessage(pfrom, CNetMsgMaker(INIT_PROTO_VERSION).Make(NetMsgType::REJECT, strCommand, REJECT_OBSOLETE,
strprintf("Version must be %d or greater", MIN_PEER_PROTO_VERSION)));
pfrom->fDisconnect = true;
return false;
}
if (nVersion == 10300)
nVersion = 300;
if (!vRecv.empty())
vRecv >> addrFrom >> nNonce;
if (!vRecv.empty()) {
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->strSubVer = strSubVer;
pfrom->cleanSubVer = cleanSubVer;
}
pfrom->nStartingHeight = nStartingHeight;
pfrom->fClient = !(nServices & NODE_NETWORK);
{
LOCK(pfrom->cs_filter);
pfrom->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)
{
// Advertise our address
if (fListen && !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();
LogPrintf("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;
}
else 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;
}
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;
}
else if (!pfrom->fSuccessfullyConnected)
{
// Must have a verack message before anything else
LOCK(cs_main);
Misbehaving(pfrom->GetId(), 1);
return false;
}
else 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 (vAddr.size() > 1000)
{
LOCK(cs_main);
Misbehaving(pfrom->GetId(), 20);
return error("message addr size() = %u", vAddr.size());
}
// 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;
if ((addr.nServices & REQUIRED_SERVICES) != REQUIRED_SERVICES)
continue;
if (addr.nTime <= 100000000 || addr.nTime > nNow + 10 * 60)
addr.nTime = nNow - 5 * 24 * 60 * 60;
pfrom->AddAddressKnown(addr);
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;
}
else if (strCommand == NetMsgType::SENDHEADERS)
{
LOCK(cs_main);
State(pfrom->GetId())->fPreferHeaders = true;
}
else 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);
}
}
}
else if (strCommand == NetMsgType::INV)
{
std::vector<CInv> vInv;
vRecv >> vInv;
if (vInv.size() > MAX_INV_SZ)
{
LOCK(cs_main);
Misbehaving(pfrom->GetId(), 20);
return error("message inv size() = %u", vInv.size());
}
bool fBlocksOnly = !fRelayTxes;
// Allow whitelisted peers to send data other than blocks in blocks only mode if whitelistrelay is true
if (pfrom->fWhitelisted && gArgs.GetBoolArg("-whitelistrelay", DEFAULT_WHITELISTRELAY))
fBlocksOnly = false;
LOCK(cs_main);
uint32_t nFetchFlags = GetFetchFlags(pfrom);
for (CInv &inv : vInv)
{
if (interruptMsgProc)
return true;
bool fAlreadyHave = AlreadyHave(inv);
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 peer=%d\n", inv.hash.ToString(), pfrom->GetId());
} else if (!fAlreadyHave && !fImporting && !fReindex && !IsInitialBlockDownload()) {
pfrom->AskFor(inv);
}
}
// Track requests for our stuff
GetMainSignals().Inventory(inv.hash);
}
}
else if (strCommand == NetMsgType::GETDATA)
{
std::vector<CInv> vInv;
vRecv >> vInv;
if (vInv.size() > MAX_INV_SZ)
{
LOCK(cs_main);
Misbehaving(pfrom->GetId(), 20);
return error("message getdata size() = %u", vInv.size());
}
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.GetConsensus(), connman, interruptMsgProc);
}
else if (strCommand == NetMsgType::GETBLOCKS)
{
CBlockLocator locator;
uint256 hashStop;
vRecv >> locator >> hashStop;
// 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;
}
CValidationState dummy;
ActivateBestChain(dummy, Params(), a_recent_block);
}
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;
}
}
}
else 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);
BlockMap::iterator it = mapBlockIndex.find(req.blockhash);
if (it == mapBlockIndex.end() || !(it->second->nStatus & BLOCK_HAVE_DATA)) {
LogPrintf("Peer %d sent us a getblocktxn for a block we don't have", pfrom->GetId());
return true;
}
if (it->second->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", 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);
ProcessGetData(pfrom, chainparams.GetConsensus(), connman, interruptMsgProc);
return true;
}
CBlock block;
bool ret = ReadBlockFromDisk(block, it->second, chainparams.GetConsensus());
assert(ret);
SendBlockTransactions(block, req, pfrom, connman);
}
else if (strCommand == NetMsgType::GETHEADERS)
{
CBlockLocator locator;
uint256 hashStop;
vRecv >> locator >> hashStop;
LOCK(cs_main);
if (IsInitialBlockDownload() && !pfrom->fWhitelisted) {
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
BlockMap::iterator mi = mapBlockIndex.find(hashStop);
if (mi == mapBlockIndex.end())
return true;
pindex = (*mi).second;
}
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));
}
else 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
if (!fRelayTxes && (!pfrom->fWhitelisted || !gArgs.GetBoolArg("-whitelistrelay", DEFAULT_WHITELISTRELAY)))
{
LogPrint(BCLog::NET, "transaction sent in violation of protocol peer=%d\n", pfrom->GetId());
return true;
}
std::deque<COutPoint> vWorkQueue;
std::vector<uint256> vEraseQueue;
CTransactionRef ptx;
vRecv >> ptx;
const CTransaction& tx = *ptx;
CInv inv(MSG_TX, tx.GetHash());
pfrom->AddInventoryKnown(inv);
LOCK(cs_main);
bool fMissingInputs = false;
CValidationState state;
pfrom->setAskFor.erase(inv.hash);
mapAlreadyAskedFor.erase(inv.hash);
std::list<CTransactionRef> lRemovedTxn;
if (!AlreadyHave(inv) && AcceptToMemoryPool(mempool, state, ptx, true, &fMissingInputs, &lRemovedTxn)) {
mempool.check(pcoinsTip);
RelayTransaction(tx, connman);
for (unsigned int i = 0; i < tx.vout.size(); i++) {
vWorkQueue.emplace_back(inv.hash, i);
}
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
std::set<NodeId> setMisbehaving;
while (!vWorkQueue.empty()) {
auto itByPrev = mapOrphanTransactionsByPrev.find(vWorkQueue.front());
vWorkQueue.pop_front();
if (itByPrev == mapOrphanTransactionsByPrev.end())
continue;
for (auto mi = itByPrev->second.begin();
mi != itByPrev->second.end();
++mi)
{
const CTransactionRef& porphanTx = (*mi)->second.tx;
const CTransaction& orphanTx = *porphanTx;
const uint256& orphanHash = orphanTx.GetHash();
NodeId fromPeer = (*mi)->second.fromPeer;
bool fMissingInputs2 = false;
// Use a dummy CValidationState so someone can't setup nodes to counter-DoS based on orphan
// resolution (that is, feeding people an invalid transaction based on LegitTxX in order to get
// anyone relaying LegitTxX banned)
CValidationState stateDummy;
if (setMisbehaving.count(fromPeer))
continue;
if (AcceptToMemoryPool(mempool, stateDummy, porphanTx, true, &fMissingInputs2, &lRemovedTxn)) {
LogPrint(BCLog::MEMPOOL, " accepted orphan tx %s\n", orphanHash.ToString());
RelayTransaction(orphanTx, connman);
for (unsigned int i = 0; i < orphanTx.vout.size(); i++) {
vWorkQueue.emplace_back(orphanHash, i);
}
vEraseQueue.push_back(orphanHash);
}
else if (!fMissingInputs2)
{
int nDos = 0;
if (stateDummy.IsInvalid(nDos) && nDos > 0)
{
// Punish peer that gave us an invalid orphan tx
Misbehaving(fromPeer, nDos);
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());
vEraseQueue.push_back(orphanHash);
if (!orphanTx.HasWitness() && !stateDummy.CorruptionPossible()) {
// 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);
}
}
mempool.check(pcoinsTip);
}
}
for (uint256 hash : vEraseQueue)
EraseOrphanTx(hash);
}
else if (fMissingInputs)
{
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);
for (const CTxIn& txin : tx.vin) {
CInv _inv(MSG_TX | nFetchFlags, txin.prevout.hash);
pfrom->AddInventoryKnown(_inv);
if (!AlreadyHave(_inv)) pfrom->AskFor(_inv);
}
AddOrphanTx(ptx, pfrom->GetId());
// DoS prevention: do not allow mapOrphanTransactions to grow unbounded
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.CorruptionPossible()) {
// 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->fWhitelisted && gArgs.GetBoolArg("-whitelistforcerelay", DEFAULT_WHITELISTFORCERELAY)) {
// Always relay transactions received from whitelisted peers, even
// if they were already in the mempool or rejected from it due
// to policy, allowing the node to function as a gateway for
// nodes hidden behind it.
//
// Never relay transactions that we would assign a non-zero DoS
// score for, as we expect peers to do the same with us in that
// case.
int nDoS = 0;
if (!state.IsInvalid(nDoS) || nDoS == 0) {
LogPrintf("Force relaying tx %s from whitelisted peer=%d\n", tx.GetHash().ToString(), pfrom->GetId());
RelayTransaction(tx, connman);
} else {
LogPrintf("Not relaying invalid transaction %s from whitelisted peer=%d (%s)\n", tx.GetHash().ToString(), pfrom->GetId(), FormatStateMessage(state));
}
}
}
for (const CTransactionRef& removedTx : lRemovedTxn)
AddToCompactExtraTransactions(removedTx);
int nDoS = 0;
if (state.IsInvalid(nDoS))
{
LogPrint(BCLog::MEMPOOLREJ, "%s from peer=%d was not accepted: %s\n", tx.GetHash().ToString(),
pfrom->GetId(),
FormatStateMessage(state));
if (state.GetRejectCode() > 0 && state.GetRejectCode() < REJECT_INTERNAL) // Never send AcceptToMemoryPool's internal codes over P2P
connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::REJECT, strCommand, (unsigned char)state.GetRejectCode(),
state.GetRejectReason().substr(0, MAX_REJECT_MESSAGE_LENGTH), inv.hash));
if (nDoS > 0) {
Misbehaving(pfrom->GetId(), nDoS);
}
}
}
else if (strCommand == NetMsgType::CMPCTBLOCK && !fImporting && !fReindex) // Ignore blocks received while importing
{
CBlockHeaderAndShortTxIDs cmpctblock;
vRecv >> cmpctblock;
{
LOCK(cs_main);
if (mapBlockIndex.find(cmpctblock.header.hashPrevBlock) == mapBlockIndex.end()) {
// Doesn't connect (or is genesis), instead of DoSing in AcceptBlockHeader, request deeper headers
if (!IsInitialBlockDownload())
connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::GETHEADERS, chainActive.GetLocator(pindexBestHeader), uint256()));
return true;
}
}
const CBlockIndex *pindex = nullptr;
CValidationState state;
if (!ProcessNewBlockHeaders({cmpctblock.header}, state, chainparams, &pindex)) {
int nDoS;
if (state.IsInvalid(nDoS)) {
if (nDoS > 0) {
LOCK(cs_main);
Misbehaving(pfrom->GetId(), nDoS);
}
LogPrintf("Peer %d sent us invalid header via cmpctblock\n", pfrom->GetId());
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;
CDataStream vHeadersMsg(SER_NETWORK, PROTOCOL_VERSION);
// Keep a CBlock for "optimistic" compactblock reconstructions (see
// below)
std::shared_ptr<CBlock> pblock = std::make_shared<CBlock>();
bool fBlockReconstructed = false;
{
LOCK(cs_main);
// If AcceptBlockHeader returned true, it set pindex
assert(pindex);
UpdateBlockAvailability(pfrom->GetId(), pindex->GetBlockHash());
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;
CNodeState *nodestate = State(pfrom->GetId());
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(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);
LogPrintf("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
// Dirty hack to process as if it were just a headers message (TODO: move message handling into their own functions)
std::vector<CBlock> headers;
headers.push_back(cmpctblock.header);
vHeadersMsg << headers;
fRevertToHeaderProcessing = true;
}
}
} // cs_main
if (fProcessBLOCKTXN)
return ProcessMessage(pfrom, NetMsgType::BLOCKTXN, blockTxnMsg, nTimeReceived, chainparams, connman, interruptMsgProc);
if (fRevertToHeaderProcessing)
return ProcessMessage(pfrom, NetMsgType::HEADERS, vHeadersMsg, nTimeReceived, chainparams, connman, interruptMsgProc);
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());
}
}
}
else if (strCommand == NetMsgType::BLOCKTXN && !fImporting && !fReindex) // Ignore blocks received while importing
{
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);
LogPrintf("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, reject messages go out, etc.
MarkBlockAsReceived(resp.blockhash); // it is now an empty pointer
fBlockRead = true;
// mapBlockSource is only used for sending reject messages and DoS scores,
// 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());
}
}
}
else if (strCommand == NetMsgType::HEADERS && !fImporting && !fReindex) // Ignore headers received while importing
{
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);
return error("headers message size = %u", nCount);
}
headers.resize(nCount);
for (unsigned int n = 0; n < nCount; n++) {
vRecv >> headers[n];
ReadCompactSize(vRecv); // ignore tx count; assume it is 0.
}
if (nCount == 0) {
// Nothing interesting. Stop asking this peers for more headers.
return true;
}
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 (mapBlockIndex.find(headers[0].hashPrevBlock) == mapBlockIndex.end() && 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);
return error("non-continuous headers sequence");
}
hashLastBlock = header.GetHash();
}
}
CValidationState state;
if (!ProcessNewBlockHeaders(headers, state, chainparams, &pindexLast)) {
int nDoS;
if (state.IsInvalid(nDoS)) {
if (nDoS > 0) {
LOCK(cs_main);
Misbehaving(pfrom->GetId(), nDoS);
}
return error("invalid header received");
}
}
{
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());
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(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 (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,
if (!(pfrom->fInbound || pfrom->fWhitelisted || pfrom->m_manual_connection)) {
pfrom->fDisconnect = true;
}
}
}
}
}
else if (strCommand == NetMsgType::BLOCK && !fImporting && !fReindex) // Ignore blocks received while importing
{
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());