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Created Oct 4, 2018

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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 "validation.h"
#include "arith_uint256.h"
#include "chainparams.h"
#include "checkpoints.h"
#include "checkqueue.h"
#include "consensus/consensus.h"
#include "consensus/merkle.h"
#include "consensus/validation.h"
#include "hash.h"
#include "init.h"
#include "policy/fees.h"
#include "policy/policy.h"
#include "pow.h"
#include "primitives/block.h"
#include "primitives/transaction.h"
#include "random.h"
#include "script/script.h"
#include "script/sigcache.h"
#include "script/standard.h"
#include "timedata.h"
#include "tinyformat.h"
#include "txdb.h"
#include "txmempool.h"
#include "ui_interface.h"
#include "undo.h"
#include "util.h"
#include "utilmoneystr.h"
#include "utilstrencodings.h"
#include "validationinterface.h"
#include "versionbits.h"
#include "warnings.h"
#include <atomic>
#include <sstream>
#include <boost/algorithm/string/replace.hpp>
#include <boost/algorithm/string/join.hpp>
#include <boost/filesystem.hpp>
#include <boost/filesystem/fstream.hpp>
#include <boost/math/distributions/poisson.hpp>
#include <boost/thread.hpp>
#if defined(NDEBUG)
# error "Litecoin cannot be compiled without assertions."
#endif
/**
* Global state
*/
CCriticalSection cs_main;
BlockMap mapBlockIndex;
CChain chainActive;
CBlockIndex *pindexBestHeader = NULL;
CWaitableCriticalSection csBestBlock;
CConditionVariable cvBlockChange;
int nScriptCheckThreads = 0;
std::atomic_bool fImporting(false);
bool fReindex = false;
bool fTxIndex = false;
bool fHavePruned = false;
bool fPruneMode = false;
bool fIsBareMultisigStd = DEFAULT_PERMIT_BAREMULTISIG;
bool fRequireStandard = true;
bool fCheckBlockIndex = false;
bool fCheckpointsEnabled = DEFAULT_CHECKPOINTS_ENABLED;
size_t nCoinCacheUsage = 5000 * 300;
uint64_t nPruneTarget = 0;
int64_t nMaxTipAge = DEFAULT_MAX_TIP_AGE;
bool fEnableReplacement = DEFAULT_ENABLE_REPLACEMENT;
uint256 hashAssumeValid;
CFeeRate minRelayTxFee = CFeeRate(DEFAULT_MIN_RELAY_TX_FEE);
CAmount maxTxFee = DEFAULT_TRANSACTION_MAXFEE;
CTxMemPool mempool(::minRelayTxFee);
static void CheckBlockIndex(const Consensus::Params& consensusParams);
/** Constant stuff for coinbase transactions we create: */
CScript COINBASE_FLAGS;
const std::string strMessageMagic = "Litecoin Signed Message:\n";
// Internal stuff
namespace {
struct CBlockIndexWorkComparator
{
bool operator()(CBlockIndex *pa, CBlockIndex *pb) const {
// First sort by most total work, ...
if (pa->nChainWork > pb->nChainWork) return false;
if (pa->nChainWork < pb->nChainWork) return true;
// ... then by earliest time received, ...
if (pa->nSequenceId < pb->nSequenceId) return false;
if (pa->nSequenceId > pb->nSequenceId) return true;
// Use pointer address as tie breaker (should only happen with blocks
// loaded from disk, as those all have id 0).
if (pa < pb) return false;
if (pa > pb) return true;
// Identical blocks.
return false;
}
};
CBlockIndex *pindexBestInvalid;
/**
* The set of all CBlockIndex entries with BLOCK_VALID_TRANSACTIONS (for itself and all ancestors) and
* as good as our current tip or better. Entries may be failed, though, and pruning nodes may be
* missing the data for the block.
*/
std::set<CBlockIndex*, CBlockIndexWorkComparator> setBlockIndexCandidates;
/** All pairs A->B, where A (or one of its ancestors) misses transactions, but B has transactions.
* Pruned nodes may have entries where B is missing data.
*/
std::multimap<CBlockIndex*, CBlockIndex*> mapBlocksUnlinked;
CCriticalSection cs_LastBlockFile;
std::vector<CBlockFileInfo> vinfoBlockFile;
int nLastBlockFile = 0;
/** Global flag to indicate we should check to see if there are
* block/undo files that should be deleted. Set on startup
* or if we allocate more file space when we're in prune mode
*/
bool fCheckForPruning = false;
/**
* Every received block is assigned a unique and increasing identifier, so we
* know which one to give priority in case of a fork.
*/
CCriticalSection cs_nBlockSequenceId;
/** Blocks loaded from disk are assigned id 0, so start the counter at 1. */
int32_t nBlockSequenceId = 1;
/** Decreasing counter (used by subsequent preciousblock calls). */
int32_t nBlockReverseSequenceId = -1;
/** chainwork for the last block that preciousblock has been applied to. */
arith_uint256 nLastPreciousChainwork = 0;
/** Dirty block index entries. */
std::set<CBlockIndex*> setDirtyBlockIndex;
/** Dirty block file entries. */
std::set<int> setDirtyFileInfo;
} // anon namespace
/* Use this class to start tracking transactions that are removed from the
* mempool and pass all those transactions through SyncTransaction when the
* object goes out of scope. This is currently only used to call SyncTransaction
* on conflicts removed from the mempool during block connection. Applied in
* ActivateBestChain around ActivateBestStep which in turn calls:
* ConnectTip->removeForBlock->removeConflicts
*/
class MemPoolConflictRemovalTracker
{
private:
std::vector<CTransactionRef> conflictedTxs;
CTxMemPool &pool;
public:
MemPoolConflictRemovalTracker(CTxMemPool &_pool) : pool(_pool) {
pool.NotifyEntryRemoved.connect(boost::bind(&MemPoolConflictRemovalTracker::NotifyEntryRemoved, this, _1, _2));
}
void NotifyEntryRemoved(CTransactionRef txRemoved, MemPoolRemovalReason reason) {
if (reason == MemPoolRemovalReason::CONFLICT) {
conflictedTxs.push_back(txRemoved);
}
}
~MemPoolConflictRemovalTracker() {
pool.NotifyEntryRemoved.disconnect(boost::bind(&MemPoolConflictRemovalTracker::NotifyEntryRemoved, this, _1, _2));
for (const auto& tx : conflictedTxs) {
GetMainSignals().SyncTransaction(*tx, NULL, CMainSignals::SYNC_TRANSACTION_NOT_IN_BLOCK);
}
conflictedTxs.clear();
}
};
CBlockIndex* FindForkInGlobalIndex(const CChain& chain, const CBlockLocator& locator)
{
// Find the first block the caller has in the main chain
BOOST_FOREACH(const uint256& hash, locator.vHave) {
BlockMap::iterator mi = mapBlockIndex.find(hash);
if (mi != mapBlockIndex.end())
{
CBlockIndex* pindex = (*mi).second;
if (chain.Contains(pindex))
return pindex;
if (pindex->GetAncestor(chain.Height()) == chain.Tip()) {
return chain.Tip();
}
}
}
return chain.Genesis();
}
CCoinsViewCache *pcoinsTip = NULL;
CBlockTreeDB *pblocktree = NULL;
enum FlushStateMode {
FLUSH_STATE_NONE,
FLUSH_STATE_IF_NEEDED,
FLUSH_STATE_PERIODIC,
FLUSH_STATE_ALWAYS
};
// See definition for documentation
bool static FlushStateToDisk(CValidationState &state, FlushStateMode mode, int nManualPruneHeight=0);
void FindFilesToPruneManual(std::set<int>& setFilesToPrune, int nManualPruneHeight);
bool IsFinalTx(const CTransaction &tx, int nBlockHeight, int64_t nBlockTime)
{
if (tx.nLockTime == 0)
return true;
if ((int64_t)tx.nLockTime < ((int64_t)tx.nLockTime < LOCKTIME_THRESHOLD ? (int64_t)nBlockHeight : nBlockTime))
return true;
for (const auto& txin : tx.vin) {
if (!(txin.nSequence == CTxIn::SEQUENCE_FINAL))
return false;
}
return true;
}
bool CheckFinalTx(const CTransaction &tx, int flags)
{
AssertLockHeld(cs_main);
// By convention a negative value for flags indicates that the
// current network-enforced consensus rules should be used. In
// a future soft-fork scenario that would mean checking which
// rules would be enforced for the next block and setting the
// appropriate flags. At the present time no soft-forks are
// scheduled, so no flags are set.
flags = std::max(flags, 0);
// CheckFinalTx() uses chainActive.Height()+1 to evaluate
// nLockTime because when IsFinalTx() is called within
// CBlock::AcceptBlock(), the height of the block *being*
// evaluated is what is used. Thus if we want to know if a
// transaction can be part of the *next* block, we need to call
// IsFinalTx() with one more than chainActive.Height().
const int nBlockHeight = chainActive.Height() + 1;
// BIP113 will require that time-locked transactions have nLockTime set to
// less than the median time of the previous block they're contained in.
// When the next block is created its previous block will be the current
// chain tip, so we use that to calculate the median time passed to
// IsFinalTx() if LOCKTIME_MEDIAN_TIME_PAST is set.
const int64_t nBlockTime = (flags & LOCKTIME_MEDIAN_TIME_PAST)
? chainActive.Tip()->GetMedianTimePast()
: GetAdjustedTime();
return IsFinalTx(tx, nBlockHeight, nBlockTime);
}
/**
* Calculates the block height and previous block's median time past at
* which the transaction will be considered final in the context of BIP 68.
* Also removes from the vector of input heights any entries which did not
* correspond to sequence locked inputs as they do not affect the calculation.
*/
static std::pair<int, int64_t> CalculateSequenceLocks(const CTransaction &tx, int flags, std::vector<int>* prevHeights, const CBlockIndex& block)
{
assert(prevHeights->size() == tx.vin.size());
// Will be set to the equivalent height- and time-based nLockTime
// values that would be necessary to satisfy all relative lock-
// time constraints given our view of block chain history.
// The semantics of nLockTime are the last invalid height/time, so
// use -1 to have the effect of any height or time being valid.
int nMinHeight = -1;
int64_t nMinTime = -1;
// tx.nVersion is signed integer so requires cast to unsigned otherwise
// we would be doing a signed comparison and half the range of nVersion
// wouldn't support BIP 68.
bool fEnforceBIP68 = static_cast<uint32_t>(tx.nVersion) >= 2
&& flags & LOCKTIME_VERIFY_SEQUENCE;
// Do not enforce sequence numbers as a relative lock time
// unless we have been instructed to
if (!fEnforceBIP68) {
return std::make_pair(nMinHeight, nMinTime);
}
for (size_t txinIndex = 0; txinIndex < tx.vin.size(); txinIndex++) {
const CTxIn& txin = tx.vin[txinIndex];
// Sequence numbers with the most significant bit set are not
// treated as relative lock-times, nor are they given any
// consensus-enforced meaning at this point.
if (txin.nSequence & CTxIn::SEQUENCE_LOCKTIME_DISABLE_FLAG) {
// The height of this input is not relevant for sequence locks
(*prevHeights)[txinIndex] = 0;
continue;
}
int nCoinHeight = (*prevHeights)[txinIndex];
if (txin.nSequence & CTxIn::SEQUENCE_LOCKTIME_TYPE_FLAG) {
int64_t nCoinTime = block.GetAncestor(std::max(nCoinHeight-1, 0))->GetMedianTimePast();
// NOTE: Subtract 1 to maintain nLockTime semantics
// BIP 68 relative lock times have the semantics of calculating
// the first block or time at which the transaction would be
// valid. When calculating the effective block time or height
// for the entire transaction, we switch to using the
// semantics of nLockTime which is the last invalid block
// time or height. Thus we subtract 1 from the calculated
// time or height.
// Time-based relative lock-times are measured from the
// smallest allowed timestamp of the block containing the
// txout being spent, which is the median time past of the
// block prior.
nMinTime = std::max(nMinTime, nCoinTime + (int64_t)((txin.nSequence & CTxIn::SEQUENCE_LOCKTIME_MASK) << CTxIn::SEQUENCE_LOCKTIME_GRANULARITY) - 1);
} else {
nMinHeight = std::max(nMinHeight, nCoinHeight + (int)(txin.nSequence & CTxIn::SEQUENCE_LOCKTIME_MASK) - 1);
}
}
return std::make_pair(nMinHeight, nMinTime);
}
static bool EvaluateSequenceLocks(const CBlockIndex& block, std::pair<int, int64_t> lockPair)
{
assert(block.pprev);
int64_t nBlockTime = block.pprev->GetMedianTimePast();
if (lockPair.first >= block.nHeight || lockPair.second >= nBlockTime)
return false;
return true;
}
bool SequenceLocks(const CTransaction &tx, int flags, std::vector<int>* prevHeights, const CBlockIndex& block)
{
return EvaluateSequenceLocks(block, CalculateSequenceLocks(tx, flags, prevHeights, block));
}
bool TestLockPointValidity(const LockPoints* lp)
{
AssertLockHeld(cs_main);
assert(lp);
// If there are relative lock times then the maxInputBlock will be set
// If there are no relative lock times, the LockPoints don't depend on the chain
if (lp->maxInputBlock) {
// Check whether chainActive is an extension of the block at which the LockPoints
// calculation was valid. If not LockPoints are no longer valid
if (!chainActive.Contains(lp->maxInputBlock)) {
return false;
}
}
// LockPoints still valid
return true;
}
bool CheckSequenceLocks(const CTransaction &tx, int flags, LockPoints* lp, bool useExistingLockPoints)
{
AssertLockHeld(cs_main);
AssertLockHeld(mempool.cs);
CBlockIndex* tip = chainActive.Tip();
CBlockIndex index;
index.pprev = tip;
// CheckSequenceLocks() uses chainActive.Height()+1 to evaluate
// height based locks because when SequenceLocks() is called within
// ConnectBlock(), the height of the block *being*
// evaluated is what is used.
// Thus if we want to know if a transaction can be part of the
// *next* block, we need to use one more than chainActive.Height()
index.nHeight = tip->nHeight + 1;
std::pair<int, int64_t> lockPair;
if (useExistingLockPoints) {
assert(lp);
lockPair.first = lp->height;
lockPair.second = lp->time;
}
else {
// pcoinsTip contains the UTXO set for chainActive.Tip()
CCoinsViewMemPool viewMemPool(pcoinsTip, mempool);
std::vector<int> prevheights;
prevheights.resize(tx.vin.size());
for (size_t txinIndex = 0; txinIndex < tx.vin.size(); txinIndex++) {
const CTxIn& txin = tx.vin[txinIndex];
CCoins coins;
if (!viewMemPool.GetCoins(txin.prevout.hash, coins)) {
return error("%s: Missing input", __func__);
}
if (coins.nHeight == MEMPOOL_HEIGHT) {
// Assume all mempool transaction confirm in the next block
prevheights[txinIndex] = tip->nHeight + 1;
} else {
prevheights[txinIndex] = coins.nHeight;
}
}
lockPair = CalculateSequenceLocks(tx, flags, &prevheights, index);
if (lp) {
lp->height = lockPair.first;
lp->time = lockPair.second;
// Also store the hash of the block with the highest height of
// all the blocks which have sequence locked prevouts.
// This hash needs to still be on the chain
// for these LockPoint calculations to be valid
// Note: It is impossible to correctly calculate a maxInputBlock
// if any of the sequence locked inputs depend on unconfirmed txs,
// except in the special case where the relative lock time/height
// is 0, which is equivalent to no sequence lock. Since we assume
// input height of tip+1 for mempool txs and test the resulting
// lockPair from CalculateSequenceLocks against tip+1. We know
// EvaluateSequenceLocks will fail if there was a non-zero sequence
// lock on a mempool input, so we can use the return value of
// CheckSequenceLocks to indicate the LockPoints validity
int maxInputHeight = 0;
BOOST_FOREACH(int height, prevheights) {
// Can ignore mempool inputs since we'll fail if they had non-zero locks
if (height != tip->nHeight+1) {
maxInputHeight = std::max(maxInputHeight, height);
}
}
lp->maxInputBlock = tip->GetAncestor(maxInputHeight);
}
}
return EvaluateSequenceLocks(index, lockPair);
}
unsigned int GetLegacySigOpCount(const CTransaction& tx)
{
unsigned int nSigOps = 0;
for (const auto& txin : tx.vin)
{
nSigOps += txin.scriptSig.GetSigOpCount(false);
}
for (const auto& txout : tx.vout)
{
nSigOps += txout.scriptPubKey.GetSigOpCount(false);
}
return nSigOps;
}
unsigned int GetP2SHSigOpCount(const CTransaction& tx, const CCoinsViewCache& inputs)
{
if (tx.IsCoinBase())
return 0;
unsigned int nSigOps = 0;
for (unsigned int i = 0; i < tx.vin.size(); i++)
{
const CTxOut &prevout = inputs.GetOutputFor(tx.vin[i]);
if (prevout.scriptPubKey.IsPayToScriptHash())
nSigOps += prevout.scriptPubKey.GetSigOpCount(tx.vin[i].scriptSig);
}
return nSigOps;
}
int64_t GetTransactionSigOpCost(const CTransaction& tx, const CCoinsViewCache& inputs, int flags)
{
int64_t nSigOps = GetLegacySigOpCount(tx) * WITNESS_SCALE_FACTOR;
if (tx.IsCoinBase())
return nSigOps;
if (flags & SCRIPT_VERIFY_P2SH) {
nSigOps += GetP2SHSigOpCount(tx, inputs) * WITNESS_SCALE_FACTOR;
}
for (unsigned int i = 0; i < tx.vin.size(); i++)
{
const CTxOut &prevout = inputs.GetOutputFor(tx.vin[i]);
nSigOps += CountWitnessSigOps(tx.vin[i].scriptSig, prevout.scriptPubKey, &tx.vin[i].scriptWitness, flags);
}
return nSigOps;
}
bool CheckTransaction(const CTransaction& tx, CValidationState &state, bool fCheckDuplicateInputs)
{
// Basic checks that don't depend on any context
if (tx.vin.empty())
return state.DoS(10, false, REJECT_INVALID, "bad-txns-vin-empty");
if (tx.vout.empty())
return state.DoS(10, false, REJECT_INVALID, "bad-txns-vout-empty");
// Size limits (this doesn't take the witness into account, as that hasn't been checked for malleability)
if (::GetSerializeSize(tx, SER_NETWORK, PROTOCOL_VERSION | SERIALIZE_TRANSACTION_NO_WITNESS) > MAX_BLOCK_BASE_SIZE)
return state.DoS(100, false, REJECT_INVALID, "bad-txns-oversize");
// Check for negative or overflow output values
CAmount nValueOut = 0;
for (const auto& txout : tx.vout)
{
if (txout.nValue < 0)
return state.DoS(100, false, REJECT_INVALID, "bad-txns-vout-negative");
if (txout.nValue > MAX_MONEY)
return state.DoS(100, false, REJECT_INVALID, "bad-txns-vout-toolarge");
nValueOut += txout.nValue;
if (!MoneyRange(nValueOut))
return state.DoS(100, false, REJECT_INVALID, "bad-txns-txouttotal-toolarge");
}
// Check for duplicate inputs - note that this check is slow so we skip it in CheckBlock
if (fCheckDuplicateInputs) {
std::set<COutPoint> vInOutPoints;
for (const auto& txin : tx.vin)
{
if (!vInOutPoints.insert(txin.prevout).second)
return state.DoS(100, false, REJECT_INVALID, "bad-txns-inputs-duplicate");
}
}
if (tx.IsCoinBase())
{
if (tx.vin[0].scriptSig.size() < 2 || tx.vin[0].scriptSig.size() > 100)
return state.DoS(100, false, REJECT_INVALID, "bad-cb-length");
}
else
{
for (const auto& txin : tx.vin)
if (txin.prevout.IsNull())
return state.DoS(10, false, REJECT_INVALID, "bad-txns-prevout-null");
}
return true;
}
void LimitMempoolSize(CTxMemPool& pool, size_t limit, unsigned long age) {
int expired = pool.Expire(GetTime() - age);
if (expired != 0)
LogPrint("mempool", "Expired %i transactions from the memory pool\n", expired);
std::vector<uint256> vNoSpendsRemaining;
pool.TrimToSize(limit, &vNoSpendsRemaining);
BOOST_FOREACH(const uint256& removed, vNoSpendsRemaining)
pcoinsTip->Uncache(removed);
}
/** Convert CValidationState to a human-readable message for logging */
std::string FormatStateMessage(const CValidationState &state)
{
return strprintf("%s%s (code %i)",
state.GetRejectReason(),
state.GetDebugMessage().empty() ? "" : ", "+state.GetDebugMessage(),
state.GetRejectCode());
}
static bool IsCurrentForFeeEstimation()
{
AssertLockHeld(cs_main);
if (IsInitialBlockDownload())
return false;
if (chainActive.Tip()->GetBlockTime() < (GetTime() - MAX_FEE_ESTIMATION_TIP_AGE))
return false;
if (chainActive.Height() < pindexBestHeader->nHeight - 1)
return false;
return true;
}
bool AcceptToMemoryPoolWorker(CTxMemPool& pool, CValidationState& state, const CTransactionRef& ptx, bool fLimitFree,
bool* pfMissingInputs, int64_t nAcceptTime, std::list<CTransactionRef>* plTxnReplaced,
bool fOverrideMempoolLimit, const CAmount& nAbsurdFee, std::vector<uint256>& vHashTxnToUncache)
{
const CTransaction& tx = *ptx;
const uint256 hash = tx.GetHash();
AssertLockHeld(cs_main);
if (pfMissingInputs)
*pfMissingInputs = false;
if (!CheckTransaction(tx, state))
return false; // state filled in by CheckTransaction
// Coinbase is only valid in a block, not as a loose transaction
if (tx.IsCoinBase())
return state.DoS(100, false, REJECT_INVALID, "coinbase");
// Reject transactions with witness before segregated witness activates (override with -prematurewitness)
bool witnessEnabled = IsWitnessEnabled(chainActive.Tip(), Params().GetConsensus());
if (!GetBoolArg("-prematurewitness",false) && tx.HasWitness() && !witnessEnabled) {
return state.DoS(0, false, REJECT_NONSTANDARD, "no-witness-yet", true);
}
// Rather not work on nonstandard transactions (unless -testnet/-regtest)
std::string reason;
if (fRequireStandard && !IsStandardTx(tx, reason, witnessEnabled))
return state.DoS(0, false, REJECT_NONSTANDARD, reason);
// Only accept nLockTime-using transactions that can be mined in the next
// block; we don't want our mempool filled up with transactions that can't
// be mined yet.
if (!CheckFinalTx(tx, STANDARD_LOCKTIME_VERIFY_FLAGS))
return state.DoS(0, false, REJECT_NONSTANDARD, "non-final");
// is it already in the memory pool?
if (pool.exists(hash))
return state.Invalid(false, REJECT_ALREADY_KNOWN, "txn-already-in-mempool");
// Check for conflicts with in-memory transactions
std::set<uint256> setConflicts;
{
LOCK(pool.cs); // protect pool.mapNextTx
BOOST_FOREACH(const CTxIn &txin, tx.vin)
{
auto itConflicting = pool.mapNextTx.find(txin.prevout);
if (itConflicting != pool.mapNextTx.end())
{
const CTransaction *ptxConflicting = itConflicting->second;
if (!setConflicts.count(ptxConflicting->GetHash()))
{
// Allow opt-out of transaction replacement by setting
// nSequence >= maxint-1 on all inputs.
//
// maxint-1 is picked to still allow use of nLockTime by
// non-replaceable transactions. All inputs rather than just one
// is for the sake of multi-party protocols, where we don't
// want a single party to be able to disable replacement.
//
// The opt-out ignores descendants as anyone relying on
// first-seen mempool behavior should be checking all
// unconfirmed ancestors anyway; doing otherwise is hopelessly
// insecure.
bool fReplacementOptOut = true;
if (fEnableReplacement)
{
BOOST_FOREACH(const CTxIn &_txin, ptxConflicting->vin)
{
if (_txin.nSequence < std::numeric_limits<unsigned int>::max()-1)
{
fReplacementOptOut = false;
break;
}
}
}
if (fReplacementOptOut)
return state.Invalid(false, REJECT_CONFLICT, "txn-mempool-conflict");
setConflicts.insert(ptxConflicting->GetHash());
}
}
}
}
{
CCoinsView dummy;
CCoinsViewCache view(&dummy);
CAmount nValueIn = 0;
LockPoints lp;
{
LOCK(pool.cs);
CCoinsViewMemPool viewMemPool(pcoinsTip, pool);
view.SetBackend(viewMemPool);
// do we already have it?
bool fHadTxInCache = pcoinsTip->HaveCoinsInCache(hash);
if (view.HaveCoins(hash)) {
if (!fHadTxInCache)
vHashTxnToUncache.push_back(hash);
return state.Invalid(false, REJECT_ALREADY_KNOWN, "txn-already-known");
}
// do all inputs exist?
// Note that this does not check for the presence of actual outputs (see the next check for that),
// and only helps with filling in pfMissingInputs (to determine missing vs spent).
BOOST_FOREACH(const CTxIn txin, tx.vin) {
if (!pcoinsTip->HaveCoinsInCache(txin.prevout.hash))
vHashTxnToUncache.push_back(txin.prevout.hash);
if (!view.HaveCoins(txin.prevout.hash)) {
if (pfMissingInputs)
*pfMissingInputs = true;
return false; // fMissingInputs and !state.IsInvalid() is used to detect this condition, don't set state.Invalid()
}
}
// are the actual inputs available?
if (!view.HaveInputs(tx))
return state.Invalid(false, REJECT_DUPLICATE, "bad-txns-inputs-spent");
// Bring the best block into scope
view.GetBestBlock();
nValueIn = view.GetValueIn(tx);
// we have all inputs cached now, so switch back to dummy, so we don't need to keep lock on mempool
view.SetBackend(dummy);
// Only accept BIP68 sequence locked transactions that can be mined in the next
// block; we don't want our mempool filled up with transactions that can't
// be mined yet.
// Must keep pool.cs for this unless we change CheckSequenceLocks to take a
// CoinsViewCache instead of create its own
if (!CheckSequenceLocks(tx, STANDARD_LOCKTIME_VERIFY_FLAGS, &lp))
return state.DoS(0, false, REJECT_NONSTANDARD, "non-BIP68-final");
}
// Check for non-standard pay-to-script-hash in inputs
if (fRequireStandard && !AreInputsStandard(tx, view))
return state.Invalid(false, REJECT_NONSTANDARD, "bad-txns-nonstandard-inputs");
// Check for non-standard witness in P2WSH
if (tx.HasWitness() && fRequireStandard && !IsWitnessStandard(tx, view))
return state.DoS(0, false, REJECT_NONSTANDARD, "bad-witness-nonstandard", true);
int64_t nSigOpsCost = GetTransactionSigOpCost(tx, view, STANDARD_SCRIPT_VERIFY_FLAGS);
CAmount nValueOut = tx.GetValueOut();
CAmount nFees = nValueIn-nValueOut;
// nModifiedFees includes any fee deltas from PrioritiseTransaction
CAmount nModifiedFees = nFees;
double nPriorityDummy = 0;
pool.ApplyDeltas(hash, nPriorityDummy, nModifiedFees);
CAmount inChainInputValue;
double dPriority = view.GetPriority(tx, chainActive.Height(), inChainInputValue);
// Keep track of transactions that spend a coinbase, which we re-scan
// during reorgs to ensure COINBASE_MATURITY is still met.
bool fSpendsCoinbase = false;
BOOST_FOREACH(const CTxIn &txin, tx.vin) {
const CCoins *coins = view.AccessCoins(txin.prevout.hash);
if (coins->IsCoinBase()) {
fSpendsCoinbase = true;
break;
}
}
CTxMemPoolEntry entry(ptx, nFees, nAcceptTime, dPriority, chainActive.Height(),
inChainInputValue, fSpendsCoinbase, nSigOpsCost, lp);
unsigned int nSize = entry.GetTxSize();
// Check that the transaction doesn't have an excessive number of
// sigops, making it impossible to mine. Since the coinbase transaction
// itself can contain sigops MAX_STANDARD_TX_SIGOPS is less than
// MAX_BLOCK_SIGOPS; we still consider this an invalid rather than
// merely non-standard transaction.
if (nSigOpsCost > MAX_STANDARD_TX_SIGOPS_COST)
return state.DoS(0, false, REJECT_NONSTANDARD, "bad-txns-too-many-sigops", false,
strprintf("%d", nSigOpsCost));
CAmount mempoolRejectFee = pool.GetMinFee(GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000).GetFee(nSize);
if (mempoolRejectFee > 0 && nModifiedFees < mempoolRejectFee) {
return state.DoS(0, false, REJECT_INSUFFICIENTFEE, "mempool min fee not met", false, strprintf("%d < %d", nFees, mempoolRejectFee));
} else if (GetBoolArg("-relaypriority", DEFAULT_RELAYPRIORITY) && nModifiedFees < ::minRelayTxFee.GetFee(nSize) && !AllowFree(entry.GetPriority(chainActive.Height() + 1))) {
// Require that free transactions have sufficient priority to be mined in the next block.
return state.DoS(0, false, REJECT_INSUFFICIENTFEE, "insufficient priority");
}
// Continuously rate-limit free (really, very-low-fee) transactions
// This mitigates 'penny-flooding' -- sending thousands of free transactions just to
// be annoying or make others' transactions take longer to confirm.
if (fLimitFree && nModifiedFees < ::minRelayTxFee.GetFee(nSize))
{
static CCriticalSection csFreeLimiter;
static double dFreeCount;
static int64_t nLastTime;
int64_t nNow = GetTime();
LOCK(csFreeLimiter);
// Use an exponentially decaying ~10-minute window:
dFreeCount *= pow(1.0 - 1.0/600.0, (double)(nNow - nLastTime));
nLastTime = nNow;
// -limitfreerelay unit is thousand-bytes-per-minute
// At default rate it would take over a month to fill 1GB
if (dFreeCount + nSize >= GetArg("-limitfreerelay", DEFAULT_LIMITFREERELAY) * 10 * 1000)
return state.DoS(0, false, REJECT_INSUFFICIENTFEE, "rate limited free transaction");
LogPrint("mempool", "Rate limit dFreeCount: %g => %g\n", dFreeCount, dFreeCount+nSize);
dFreeCount += nSize;
}
if (nAbsurdFee && nFees > nAbsurdFee)
return state.Invalid(false,
REJECT_HIGHFEE, "absurdly-high-fee",
strprintf("%d > %d", nFees, nAbsurdFee));
// Calculate in-mempool ancestors, up to a limit.
CTxMemPool::setEntries setAncestors;
size_t nLimitAncestors = GetArg("-limitancestorcount", DEFAULT_ANCESTOR_LIMIT);
size_t nLimitAncestorSize = GetArg("-limitancestorsize", DEFAULT_ANCESTOR_SIZE_LIMIT)*1000;
size_t nLimitDescendants = GetArg("-limitdescendantcount", DEFAULT_DESCENDANT_LIMIT);
size_t nLimitDescendantSize = GetArg("-limitdescendantsize", DEFAULT_DESCENDANT_SIZE_LIMIT)*1000;
std::string errString;
if (!pool.CalculateMemPoolAncestors(entry, setAncestors, nLimitAncestors, nLimitAncestorSize, nLimitDescendants, nLimitDescendantSize, errString)) {
return state.DoS(0, false, REJECT_NONSTANDARD, "too-long-mempool-chain", false, errString);
}
// A transaction that spends outputs that would be replaced by it is invalid. Now
// that we have the set of all ancestors we can detect this
// pathological case by making sure setConflicts and setAncestors don't
// intersect.
BOOST_FOREACH(CTxMemPool::txiter ancestorIt, setAncestors)
{
const uint256 &hashAncestor = ancestorIt->GetTx().GetHash();
if (setConflicts.count(hashAncestor))
{
return state.DoS(10, false,
REJECT_INVALID, "bad-txns-spends-conflicting-tx", false,
strprintf("%s spends conflicting transaction %s",
hash.ToString(),
hashAncestor.ToString()));
}
}
// Check if it's economically rational to mine this transaction rather
// than the ones it replaces.
CAmount nConflictingFees = 0;
size_t nConflictingSize = 0;
uint64_t nConflictingCount = 0;
CTxMemPool::setEntries allConflicting;
// If we don't hold the lock allConflicting might be incomplete; the
// subsequent RemoveStaged() and addUnchecked() calls don't guarantee
// mempool consistency for us.
LOCK(pool.cs);
const bool fReplacementTransaction = setConflicts.size();
if (fReplacementTransaction)
{
CFeeRate newFeeRate(nModifiedFees, nSize);
std::set<uint256> setConflictsParents;
const int maxDescendantsToVisit = 100;
CTxMemPool::setEntries setIterConflicting;
BOOST_FOREACH(const uint256 &hashConflicting, setConflicts)
{
CTxMemPool::txiter mi = pool.mapTx.find(hashConflicting);
if (mi == pool.mapTx.end())
continue;
// Save these to avoid repeated lookups
setIterConflicting.insert(mi);
// Don't allow the replacement to reduce the feerate of the
// mempool.
//
// We usually don't want to accept replacements with lower
// feerates than what they replaced as that would lower the
// feerate of the next block. Requiring that the feerate always
// be increased is also an easy-to-reason about way to prevent
// DoS attacks via replacements.
//
// The mining code doesn't (currently) take children into
// account (CPFP) so we only consider the feerates of
// transactions being directly replaced, not their indirect
// descendants. While that does mean high feerate children are
// ignored when deciding whether or not to replace, we do
// require the replacement to pay more overall fees too,
// mitigating most cases.
CFeeRate oldFeeRate(mi->GetModifiedFee(), mi->GetTxSize());
if (newFeeRate <= oldFeeRate)
{
return state.DoS(0, false,
REJECT_INSUFFICIENTFEE, "insufficient fee", false,
strprintf("rejecting replacement %s; new feerate %s <= old feerate %s",
hash.ToString(),
newFeeRate.ToString(),
oldFeeRate.ToString()));
}
BOOST_FOREACH(const CTxIn &txin, mi->GetTx().vin)
{
setConflictsParents.insert(txin.prevout.hash);
}
nConflictingCount += mi->GetCountWithDescendants();
}
// This potentially overestimates the number of actual descendants
// but we just want to be conservative to avoid doing too much
// work.
if (nConflictingCount <= maxDescendantsToVisit) {
// If not too many to replace, then calculate the set of
// transactions that would have to be evicted
BOOST_FOREACH(CTxMemPool::txiter it, setIterConflicting) {
pool.CalculateDescendants(it, allConflicting);
}
BOOST_FOREACH(CTxMemPool::txiter it, allConflicting) {
nConflictingFees += it->GetModifiedFee();
nConflictingSize += it->GetTxSize();
}
} else {
return state.DoS(0, false,
REJECT_NONSTANDARD, "too many potential replacements", false,
strprintf("rejecting replacement %s; too many potential replacements (%d > %d)\n",
hash.ToString(),
nConflictingCount,
maxDescendantsToVisit));
}
for (unsigned int j = 0; j < tx.vin.size(); j++)
{
// We don't want to accept replacements that require low
// feerate junk to be mined first. Ideally we'd keep track of
// the ancestor feerates and make the decision based on that,
// but for now requiring all new inputs to be confirmed works.
if (!setConflictsParents.count(tx.vin[j].prevout.hash))
{
// Rather than check the UTXO set - potentially expensive -
// it's cheaper to just check if the new input refers to a
// tx that's in the mempool.
if (pool.mapTx.find(tx.vin[j].prevout.hash) != pool.mapTx.end())
return state.DoS(0, false,
REJECT_NONSTANDARD, "replacement-adds-unconfirmed", false,
strprintf("replacement %s adds unconfirmed input, idx %d",
hash.ToString(), j));
}
}
// The replacement must pay greater fees than the transactions it
// replaces - if we did the bandwidth used by those conflicting
// transactions would not be paid for.
if (nModifiedFees < nConflictingFees)
{
return state.DoS(0, false,
REJECT_INSUFFICIENTFEE, "insufficient fee", false,
strprintf("rejecting replacement %s, less fees than conflicting txs; %s < %s",
hash.ToString(), FormatMoney(nModifiedFees), FormatMoney(nConflictingFees)));
}
// Finally in addition to paying more fees than the conflicts the
// new transaction must pay for its own bandwidth.
CAmount nDeltaFees = nModifiedFees - nConflictingFees;
if (nDeltaFees < ::incrementalRelayFee.GetFee(nSize))
{
return state.DoS(0, false,
REJECT_INSUFFICIENTFEE, "insufficient fee", false,
strprintf("rejecting replacement %s, not enough additional fees to relay; %s < %s",
hash.ToString(),
FormatMoney(nDeltaFees),
FormatMoney(::incrementalRelayFee.GetFee(nSize))));
}
}
unsigned int scriptVerifyFlags = STANDARD_SCRIPT_VERIFY_FLAGS;
if (!Params().RequireStandard()) {
scriptVerifyFlags = GetArg("-promiscuousmempoolflags", scriptVerifyFlags);
}
// Check against previous transactions
// This is done last to help prevent CPU exhaustion denial-of-service attacks.
PrecomputedTransactionData txdata(tx);
if (!CheckInputs(tx, state, view, true, scriptVerifyFlags, true, txdata)) {
// SCRIPT_VERIFY_CLEANSTACK requires SCRIPT_VERIFY_WITNESS, so we
// need to turn both off, and compare against just turning off CLEANSTACK
// to see if the failure is specifically due to witness validation.
CValidationState stateDummy; // Want reported failures to be from first CheckInputs
if (!tx.HasWitness() && CheckInputs(tx, stateDummy, view, true, scriptVerifyFlags & ~(SCRIPT_VERIFY_WITNESS | SCRIPT_VERIFY_CLEANSTACK), true, txdata) &&
!CheckInputs(tx, stateDummy, view, true, scriptVerifyFlags & ~SCRIPT_VERIFY_CLEANSTACK, true, txdata)) {
// Only the witness is missing, so the transaction itself may be fine.
state.SetCorruptionPossible();
}
return false; // state filled in by CheckInputs
}
// Check again against just the consensus-critical mandatory script
// verification flags, in case of bugs in the standard flags that cause
// transactions to pass as valid when they're actually invalid. For
// instance the STRICTENC flag was incorrectly allowing certain
// CHECKSIG NOT scripts to pass, even though they were invalid.
//
// There is a similar check in CreateNewBlock() to prevent creating
// invalid blocks, however allowing such transactions into the mempool
// can be exploited as a DoS attack.
if (!CheckInputs(tx, state, view, true, MANDATORY_SCRIPT_VERIFY_FLAGS, true, txdata))
{
return error("%s: BUG! PLEASE REPORT THIS! ConnectInputs failed against MANDATORY but not STANDARD flags %s, %s",
__func__, hash.ToString(), FormatStateMessage(state));
}
// Remove conflicting transactions from the mempool
BOOST_FOREACH(const CTxMemPool::txiter it, allConflicting)
{
LogPrint("mempool", "replacing tx %s with %s for %s LTC additional fees, %d delta bytes\n",
it->GetTx().GetHash().ToString(),
hash.ToString(),
FormatMoney(nModifiedFees - nConflictingFees),
(int)nSize - (int)nConflictingSize);
if (plTxnReplaced)
plTxnReplaced->push_back(it->GetSharedTx());
}
pool.RemoveStaged(allConflicting, false, MemPoolRemovalReason::REPLACED);
// This transaction should only count for fee estimation if it isn't a
// BIP 125 replacement transaction (may not be widely supported), the
// node is not behind, and the transaction is not dependent on any other
// transactions in the mempool.
bool validForFeeEstimation = !fReplacementTransaction && IsCurrentForFeeEstimation() && pool.HasNoInputsOf(tx);
// Store transaction in memory
pool.addUnchecked(hash, entry, setAncestors, validForFeeEstimation);
// trim mempool and check if tx was trimmed
if (!fOverrideMempoolLimit) {
LimitMempoolSize(pool, GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000, GetArg("-mempoolexpiry", DEFAULT_MEMPOOL_EXPIRY) * 60 * 60);
if (!pool.exists(hash))
return state.DoS(0, false, REJECT_INSUFFICIENTFEE, "mempool full");
}
}
GetMainSignals().SyncTransaction(tx, NULL, CMainSignals::SYNC_TRANSACTION_NOT_IN_BLOCK);
return true;
}
bool AcceptToMemoryPoolWithTime(CTxMemPool& pool, CValidationState &state, const CTransactionRef &tx, bool fLimitFree,
bool* pfMissingInputs, int64_t nAcceptTime, std::list<CTransactionRef>* plTxnReplaced,
bool fOverrideMempoolLimit, const CAmount nAbsurdFee)
{
std::vector<uint256> vHashTxToUncache;
bool res = AcceptToMemoryPoolWorker(pool, state, tx, fLimitFree, pfMissingInputs, nAcceptTime, plTxnReplaced, fOverrideMempoolLimit, nAbsurdFee, vHashTxToUncache);
if (!res) {
BOOST_FOREACH(const uint256& hashTx, vHashTxToUncache)
pcoinsTip->Uncache(hashTx);
}
// After we've (potentially) uncached entries, ensure our coins cache is still within its size limits
CValidationState stateDummy;
FlushStateToDisk(stateDummy, FLUSH_STATE_PERIODIC);
return res;
}
bool AcceptToMemoryPool(CTxMemPool& pool, CValidationState &state, const CTransactionRef &tx, bool fLimitFree,
bool* pfMissingInputs, std::list<CTransactionRef>* plTxnReplaced,
bool fOverrideMempoolLimit, const CAmount nAbsurdFee)
{
return AcceptToMemoryPoolWithTime(pool, state, tx, fLimitFree, pfMissingInputs, GetTime(), plTxnReplaced, fOverrideMempoolLimit, nAbsurdFee);
}
/** Return transaction in txOut, and if it was found inside a block, its hash is placed in hashBlock */
bool GetTransaction(const uint256 &hash, CTransactionRef &txOut, const Consensus::Params& consensusParams, uint256 &hashBlock, bool fAllowSlow)
{
CBlockIndex *pindexSlow = NULL;
LOCK(cs_main);
CTransactionRef ptx = mempool.get(hash);
if (ptx)
{
txOut = ptx;
return true;
}
if (fTxIndex) {
CDiskTxPos postx;
if (pblocktree->ReadTxIndex(hash, postx)) {
CAutoFile file(OpenBlockFile(postx, true), SER_DISK, CLIENT_VERSION);
if (file.IsNull())
return error("%s: OpenBlockFile failed", __func__);
CBlockHeader header;
try {
file >> header;
fseek(file.Get(), postx.nTxOffset, SEEK_CUR);
file >> txOut;
} catch (const std::exception& e) {
return error("%s: Deserialize or I/O error - %s", __func__, e.what());
}
hashBlock = header.GetHash();
if (txOut->GetHash() != hash)
return error("%s: txid mismatch", __func__);
return true;
}
}
if (fAllowSlow) { // use coin database to locate block that contains transaction, and scan it
int nHeight = -1;
{
const CCoinsViewCache& view = *pcoinsTip;
const CCoins* coins = view.AccessCoins(hash);
if (coins)
nHeight = coins->nHeight;
}
if (nHeight > 0)
pindexSlow = chainActive[nHeight];
}
if (pindexSlow) {
CBlock block;
if (ReadBlockFromDisk(block, pindexSlow, consensusParams)) {
for (const auto& tx : block.vtx) {
if (tx->GetHash() == hash) {
txOut = tx;
hashBlock = pindexSlow->GetBlockHash();
return true;
}
}
}
}
return false;
}
//////////////////////////////////////////////////////////////////////////////
//
// CBlock and CBlockIndex
//
bool WriteBlockToDisk(const CBlock& block, CDiskBlockPos& pos, const CMessageHeader::MessageStartChars& messageStart)
{
// Open history file to append
CAutoFile fileout(OpenBlockFile(pos), SER_DISK, CLIENT_VERSION);
if (fileout.IsNull())
return error("WriteBlockToDisk: OpenBlockFile failed");
// Write index header
unsigned int nSize = GetSerializeSize(fileout, block);
fileout << FLATDATA(messageStart) << nSize;
// Write block
long fileOutPos = ftell(fileout.Get());
if (fileOutPos < 0)
return error("WriteBlockToDisk: ftell failed");
pos.nPos = (unsigned int)fileOutPos;
fileout << block;
return true;
}
bool ReadBlockFromDisk(CBlock& block, const CDiskBlockPos& pos, const Consensus::Params& consensusParams)
{
block.SetNull();
// Open history file to read
CAutoFile filein(OpenBlockFile(pos, true), SER_DISK, CLIENT_VERSION);
if (filein.IsNull())
return error("ReadBlockFromDisk: OpenBlockFile failed for %s", pos.ToString());
// Read block
try {
filein >> block;
}
catch (const std::exception& e) {
return error("%s: Deserialize or I/O error - %s at %s", __func__, e.what(), pos.ToString());
}
// Check the header
if (!CheckProofOfWork(block.GetPoWHash(), block.nBits, consensusParams))
return error("ReadBlockFromDisk: Errors in block header at %s", pos.ToString());
return true;
}
bool ReadBlockFromDisk(CBlock& block, const CBlockIndex* pindex, const Consensus::Params& consensusParams)
{
if (!ReadBlockFromDisk(block, pindex->GetBlockPos(), consensusParams))
return false;
if (block.GetHash() != pindex->GetBlockHash())
return error("ReadBlockFromDisk(CBlock&, CBlockIndex*): GetHash() doesn't match index for %s at %s",
pindex->ToString(), pindex->GetBlockPos().ToString());
return true;
}
CAmount GetBlockSubsidy(int nHeight, const Consensus::Params& consensusParams)
{
int halvings = nHeight / consensusParams.nSubsidyHalvingInterval;
// Force block reward to zero when right shift is undefined.
if (halvings >= 64)
return 0;
CAmount nSubsidy = 50 * COIN;
// Subsidy is cut in half every 210,000 blocks which will occur approximately every 4 years.
nSubsidy >>= halvings;
return nSubsidy;
}
bool IsInitialBlockDownload()
{
const CChainParams& chainParams = Params();
// Once this function has returned false, it must remain false.
static std::atomic<bool> latchToFalse{false};
// Optimization: pre-test latch before taking the lock.
if (latchToFalse.load(std::memory_order_relaxed))
return false;
LOCK(cs_main);
if (latchToFalse.load(std::memory_order_relaxed))
return false;
if (fImporting || fReindex)
return true;
if (chainActive.Tip() == NULL)
return true;
if (chainActive.Tip()->nChainWork < UintToArith256(chainParams.GetConsensus().nMinimumChainWork))
return true;
if (chainActive.Tip()->GetBlockTime() < (GetTime() - nMaxTipAge))
return true;
latchToFalse.store(true, std::memory_order_relaxed);
return false;
}
CBlockIndex *pindexBestForkTip = NULL, *pindexBestForkBase = NULL;
static void AlertNotify(const std::string& strMessage)
{
uiInterface.NotifyAlertChanged();
std::string strCmd = GetArg("-alertnotify", "");
if (strCmd.empty()) return;
// Alert text should be plain ascii coming from a trusted source, but to
// be safe we first strip anything not in safeChars, then add single quotes around
// the whole string before passing it to the shell:
std::string singleQuote("'");
std::string safeStatus = SanitizeString(strMessage);
safeStatus = singleQuote+safeStatus+singleQuote;
boost::replace_all(strCmd, "%s", safeStatus);
boost::thread t(runCommand, strCmd); // thread runs free
}
void CheckForkWarningConditions()
{
AssertLockHeld(cs_main);
// Before we get past initial download, we cannot reliably alert about forks
// (we assume we don't get stuck on a fork before finishing our initial sync)
if (IsInitialBlockDownload())
return;
// If our best fork is no longer within 72 blocks (+/- 12 hours if no one mines it)
// of our head, drop it
if (pindexBestForkTip && chainActive.Height() - pindexBestForkTip->nHeight >= 72)
pindexBestForkTip = NULL;
if (pindexBestForkTip || (pindexBestInvalid && pindexBestInvalid->nChainWork > chainActive.Tip()->nChainWork + (GetBlockProof(*chainActive.Tip()) * 6)))
{
if (!GetfLargeWorkForkFound() && pindexBestForkBase)
{
std::string warning = std::string("'Warning: Large-work fork detected, forking after block ") +
pindexBestForkBase->phashBlock->ToString() + std::string("'");
AlertNotify(warning);
}
if (pindexBestForkTip && pindexBestForkBase)
{
LogPrintf("%s: Warning: Large valid fork found\n forking the chain at height %d (%s)\n lasting to height %d (%s).\nChain state database corruption likely.\n", __func__,
pindexBestForkBase->nHeight, pindexBestForkBase->phashBlock->ToString(),
pindexBestForkTip->nHeight, pindexBestForkTip->phashBlock->ToString());
SetfLargeWorkForkFound(true);
}
else
{
LogPrintf("%s: Warning: Found invalid chain at least ~6 blocks longer than our best chain.\nChain state database corruption likely.\n", __func__);
SetfLargeWorkInvalidChainFound(true);
}
}
else
{
SetfLargeWorkForkFound(false);
SetfLargeWorkInvalidChainFound(false);
}
}
void CheckForkWarningConditionsOnNewFork(CBlockIndex* pindexNewForkTip)
{
AssertLockHeld(cs_main);
// If we are on a fork that is sufficiently large, set a warning flag
CBlockIndex* pfork = pindexNewForkTip;
CBlockIndex* plonger = chainActive.Tip();
while (pfork && pfork != plonger)
{
while (plonger && plonger->nHeight > pfork->nHeight)
plonger = plonger->pprev;
if (pfork == plonger)
break;
pfork = pfork->pprev;
}
// We define a condition where we should warn the user about as a fork of at least 7 blocks
// with a tip within 72 blocks (+/- 12 hours if no one mines it) of ours
// We use 7 blocks rather arbitrarily as it represents just under 10% of sustained network
// hash rate operating on the fork.
// or a chain that is entirely longer than ours and invalid (note that this should be detected by both)
// We define it this way because it allows us to only store the highest fork tip (+ base) which meets
// the 7-block condition and from this always have the most-likely-to-cause-warning fork
if (pfork && (!pindexBestForkTip || (pindexBestForkTip && pindexNewForkTip->nHeight > pindexBestForkTip->nHeight)) &&
pindexNewForkTip->nChainWork - pfork->nChainWork > (GetBlockProof(*pfork) * 7) &&
chainActive.Height() - pindexNewForkTip->nHeight < 72)
{
pindexBestForkTip = pindexNewForkTip;
pindexBestForkBase = pfork;
}
CheckForkWarningConditions();
}
void static InvalidChainFound(CBlockIndex* pindexNew)
{
if (!pindexBestInvalid || pindexNew->nChainWork > pindexBestInvalid->nChainWork)
pindexBestInvalid = pindexNew;
LogPrintf("%s: invalid block=%s height=%d log2_work=%.8g date=%s\n", __func__,
pindexNew->GetBlockHash().ToString(), pindexNew->nHeight,
log(pindexNew->nChainWork.getdouble())/log(2.0), DateTimeStrFormat("%Y-%m-%d %H:%M:%S",
pindexNew->GetBlockTime()));
CBlockIndex *tip = chainActive.Tip();
assert (tip);
LogPrintf("%s: current best=%s height=%d log2_work=%.8g date=%s\n", __func__,
tip->GetBlockHash().ToString(), chainActive.Height(), log(tip->nChainWork.getdouble())/log(2.0),
DateTimeStrFormat("%Y-%m-%d %H:%M:%S", tip->GetBlockTime()));
CheckForkWarningConditions();
}
void static InvalidBlockFound(CBlockIndex *pindex, const CValidationState &state) {
if (!state.CorruptionPossible()) {
pindex->nStatus |= BLOCK_FAILED_VALID;
setDirtyBlockIndex.insert(pindex);
setBlockIndexCandidates.erase(pindex);
InvalidChainFound(pindex);
}
}
void UpdateCoins(const CTransaction& tx, CCoinsViewCache& inputs, CTxUndo &txundo, int nHeight)
{
// mark inputs spent
if (!tx.IsCoinBase()) {
txundo.vprevout.reserve(tx.vin.size());
BOOST_FOREACH(const CTxIn &txin, tx.vin) {
CCoinsModifier coins = inputs.ModifyCoins(txin.prevout.hash);
unsigned nPos = txin.prevout.n;
if (nPos >= coins->vout.size() || coins->vout[nPos].IsNull())
assert(false);
// mark an outpoint spent, and construct undo information
txundo.vprevout.push_back(CTxInUndo(coins->vout[nPos]));
coins->Spend(nPos);
if (coins->vout.size() == 0) {
CTxInUndo& undo = txundo.vprevout.back();
undo.nHeight = coins->nHeight;
undo.fCoinBase = coins->fCoinBase;
undo.nVersion = coins->nVersion;
}
}
}
// add outputs
inputs.ModifyNewCoins(tx.GetHash(), tx.IsCoinBase())->FromTx(tx, nHeight);
}
void UpdateCoins(const CTransaction& tx, CCoinsViewCache& inputs, int nHeight)
{
CTxUndo txundo;
UpdateCoins(tx, inputs, txundo, nHeight);
}
bool CScriptCheck::operator()() {
const CScript &scriptSig = ptxTo->vin[nIn].scriptSig;
const CScriptWitness *witness = &ptxTo->vin[nIn].scriptWitness;
if (!VerifyScript(scriptSig, scriptPubKey, witness, nFlags, CachingTransactionSignatureChecker(ptxTo, nIn, amount, cacheStore, *txdata), &error)) {
return false;
}
return true;
}
int GetSpendHeight(const CCoinsViewCache& inputs)
{
LOCK(cs_main);
CBlockIndex* pindexPrev = mapBlockIndex.find(inputs.GetBestBlock())->second;
return pindexPrev->nHeight + 1;
}
namespace Consensus {
bool CheckTxInputs(const CTransaction& tx, CValidationState& state, const CCoinsViewCache& inputs, int nSpendHeight)
{
// This doesn't trigger the DoS code on purpose; if it did, it would make it easier
// for an attacker to attempt to split the network.
if (!inputs.HaveInputs(tx))
return state.Invalid(false, 0, "", "Inputs unavailable");
CAmount nValueIn = 0;
CAmount nFees = 0;
for (unsigned int i = 0; i < tx.vin.size(); i++)
{
const COutPoint &prevout = tx.vin[i].prevout;
const CCoins *coins = inputs.AccessCoins(prevout.hash);
assert(coins);
// If prev is coinbase, check that it's matured
if (coins->IsCoinBase()) {
if (nSpendHeight - coins->nHeight < COINBASE_MATURITY)
return state.Invalid(false,
REJECT_INVALID, "bad-txns-premature-spend-of-coinbase",
strprintf("tried to spend coinbase at depth %d", nSpendHeight - coins->nHeight));
}
// Check for negative or overflow input values
nValueIn += coins->vout[prevout.n].nValue;
if (!MoneyRange(coins->vout[prevout.n].nValue) || !MoneyRange(nValueIn))
return state.DoS(100, false, REJECT_INVALID, "bad-txns-inputvalues-outofrange");
}
if (nValueIn < tx.GetValueOut())
return state.DoS(100, false, REJECT_INVALID, "bad-txns-in-belowout", false,
strprintf("value in (%s) < value out (%s)", FormatMoney(nValueIn), FormatMoney(tx.GetValueOut())));
// Tally transaction fees
CAmount nTxFee = nValueIn - tx.GetValueOut();
if (nTxFee < 0)
return state.DoS(100, false, REJECT_INVALID, "bad-txns-fee-negative");
nFees += nTxFee;
if (!MoneyRange(nFees))
return state.DoS(100, false, REJECT_INVALID, "bad-txns-fee-outofrange");
return true;
}
}// namespace Consensus
bool CheckInputs(const CTransaction& tx, CValidationState &state, const CCoinsViewCache &inputs, bool fScriptChecks, unsigned int flags, bool cacheStore, PrecomputedTransactionData& txdata, std::vector<CScriptCheck> *pvChecks)
{
if (!tx.IsCoinBase())
{
if (!Consensus::CheckTxInputs(tx, state, inputs, GetSpendHeight(inputs)))
return false;
if (pvChecks)
pvChecks->reserve(tx.vin.size());
// The first loop above does all the inexpensive checks.
// Only if ALL inputs pass do we perform expensive ECDSA signature checks.
// Helps prevent CPU exhaustion attacks.
// Skip script verification when connecting blocks under the
// assumedvalid block. Assuming the assumedvalid block is valid this
// is safe because block merkle hashes are still computed and checked,
// Of course, if an assumed valid block is invalid due to false scriptSigs
// this optimization would allow an invalid chain to be accepted.
if (fScriptChecks) {
for (unsigned int i = 0; i < tx.vin.size(); i++) {
const COutPoint &prevout = tx.vin[i].prevout;
const CCoins* coins = inputs.AccessCoins(prevout.hash);
assert(coins);
// Verify signature
CScriptCheck check(*coins, tx, i, flags, cacheStore, &txdata);
if (pvChecks) {
pvChecks->push_back(CScriptCheck());
check.swap(pvChecks->back());
} else if (!check()) {
if (flags & STANDARD_NOT_MANDATORY_VERIFY_FLAGS) {
// Check whether the failure was caused by a
// non-mandatory script verification check, such as
// non-standard DER encodings or non-null dummy
// arguments; if so, don't trigger DoS protection to
// avoid splitting the network between upgraded and
// non-upgraded nodes.
CScriptCheck check2(*coins, tx, i,
flags & ~STANDARD_NOT_MANDATORY_VERIFY_FLAGS, cacheStore, &txdata);
if (check2())
return state.Invalid(false, REJECT_NONSTANDARD, strprintf("non-mandatory-script-verify-flag (%s)", ScriptErrorString(check.GetScriptError())));
}
// Failures of other flags indicate a transaction that is
// invalid in new blocks, e.g. a invalid P2SH. We DoS ban
// such nodes as they are not following the protocol. That
// said during an upgrade careful thought should be taken
// as to the correct behavior - we may want to continue
// peering with non-upgraded nodes even after soft-fork
// super-majority signaling has occurred.
return state.DoS(100,false, REJECT_INVALID, strprintf("mandatory-script-verify-flag-failed (%s)", ScriptErrorString(check.GetScriptError())));
}
}
}
}
return true;
}
namespace {
bool UndoWriteToDisk(const CBlockUndo& blockundo, CDiskBlockPos& pos, const uint256& hashBlock, const CMessageHeader::MessageStartChars& messageStart)
{
// Open history file to append
CAutoFile fileout(OpenUndoFile(pos), SER_DISK, CLIENT_VERSION);
if (fileout.IsNull())
return error("%s: OpenUndoFile failed", __func__);
// Write index header
unsigned int nSize = GetSerializeSize(fileout, blockundo);
fileout << FLATDATA(messageStart) << nSize;
// Write undo data
long fileOutPos = ftell(fileout.Get());
if (fileOutPos < 0)
return error("%s: ftell failed", __func__);
pos.nPos = (unsigned int)fileOutPos;
fileout << blockundo;
// calculate & write checksum
CHashWriter hasher(SER_GETHASH, PROTOCOL_VERSION);
hasher << hashBlock;
hasher << blockundo;
fileout << hasher.GetHash();
return true;
}
bool UndoReadFromDisk(CBlockUndo& blockundo, const CDiskBlockPos& pos, const uint256& hashBlock)
{
// Open history file to read
CAutoFile filein(OpenUndoFile(pos, true), SER_DISK, CLIENT_VERSION);
if (filein.IsNull())
return error("%s: OpenUndoFile failed", __func__);
// Read block
uint256 hashChecksum;
try {
filein >> blockundo;
filein >> hashChecksum;
}
catch (const std::exception& e) {
return error("%s: Deserialize or I/O error - %s", __func__, e.what());
}
// Verify checksum
CHashWriter hasher(SER_GETHASH, PROTOCOL_VERSION);
hasher << hashBlock;
hasher << blockundo;
if (hashChecksum != hasher.GetHash())
return error("%s: Checksum mismatch", __func__);
return true;
}
/** Abort with a message */
bool AbortNode(const std::string& strMessage, const std::string& userMessage="")
{
SetMiscWarning(strMessage);
LogPrintf("*** %s\n", strMessage);
uiInterface.ThreadSafeMessageBox(
userMessage.empty() ? _("Error: A fatal internal error occurred, see debug.log for details") : userMessage,
"", CClientUIInterface::MSG_ERROR);
StartShutdown();
return false;
}
bool AbortNode(CValidationState& state, const std::string& strMessage, const std::string& userMessage="")
{
AbortNode(strMessage, userMessage);
return state.Error(strMessage);
}
} // anon namespace
/**
* Apply the undo operation of a CTxInUndo to the given chain state.
* @param undo The undo object.
* @param view The coins view to which to apply the changes.
* @param out The out point that corresponds to the tx input.
* @return True on success.
*/
bool ApplyTxInUndo(const CTxInUndo& undo, CCoinsViewCache& view, const COutPoint& out)
{
bool fClean = true;
CCoinsModifier coins = view.ModifyCoins(out.hash);
if (undo.nHeight != 0) {
// undo data contains height: this is the last output of the prevout tx being spent
if (!coins->IsPruned())
fClean = fClean && error("%s: undo data overwriting existing transaction", __func__);
coins->Clear();
coins->fCoinBase = undo.fCoinBase;
coins->nHeight = undo.nHeight;
coins->nVersion = undo.nVersion;
} else {
if (coins->IsPruned())
fClean = fClean && error("%s: undo data adding output to missing transaction", __func__);
}
if (coins->IsAvailable(out.n))
fClean = fClean && error("%s: undo data overwriting existing output", __func__);
if (coins->vout.size() < out.n+1)
coins->vout.resize(out.n+1);
coins->vout[out.n] = undo.txout;
return fClean;
}
bool DisconnectBlock(const CBlock& block, CValidationState& state, const CBlockIndex* pindex, CCoinsViewCache& view, bool* pfClean)
{
assert(pindex->GetBlockHash() == view.GetBestBlock());
if (pfClean)
*pfClean = false;
bool fClean = true;
CBlockUndo blockUndo;
CDiskBlockPos pos = pindex->GetUndoPos();
if (pos.IsNull())
return error("DisconnectBlock(): no undo data available");
if (!UndoReadFromDisk(blockUndo, pos, pindex->pprev->GetBlockHash()))
return error("DisconnectBlock(): failure reading undo data");
if (blockUndo.vtxundo.size() + 1 != block.vtx.size())
return error("DisconnectBlock(): block and undo data inconsistent");
// undo transactions in reverse order
for (int i = block.vtx.size() - 1; i >= 0; i--) {
const CTransaction &tx = *(block.vtx[i]);
uint256 hash = tx.GetHash();
// Check that all outputs are available and match the outputs in the block itself
// exactly.
{
CCoinsModifier outs = view.ModifyCoins(hash);
outs->ClearUnspendable();
CCoins outsBlock(tx, pindex->nHeight);
// The CCoins serialization does not serialize negative numbers.
// No network rules currently depend on the version here, so an inconsistency is harmless
// but it must be corrected before txout nversion ever influences a network rule.
if (outsBlock.nVersion < 0)
outs->nVersion = outsBlock.nVersion;
if (*outs != outsBlock)
fClean = fClean && error("DisconnectBlock(): added transaction mismatch? database corrupted");
// remove outputs
outs->Clear();
}
// restore inputs
if (i > 0) { // not coinbases
const CTxUndo &txundo = blockUndo.vtxundo[i-1];
if (txundo.vprevout.size() != tx.vin.size())
return error("DisconnectBlock(): transaction and undo data inconsistent");
for (unsigned int j = tx.vin.size(); j-- > 0;) {
const COutPoint &out = tx.vin[j].prevout;
const CTxInUndo &undo = txundo.vprevout[j];
if (!ApplyTxInUndo(undo, view, out))
fClean = false;
}
}
}
// move best block pointer to prevout block
view.SetBestBlock(pindex->pprev->GetBlockHash());
if (pfClean) {
*pfClean = fClean;
return true;
}
return fClean;
}
void static FlushBlockFile(bool fFinalize = false)
{
LOCK(cs_LastBlockFile);
CDiskBlockPos posOld(nLastBlockFile, 0);
FILE *fileOld = OpenBlockFile(posOld);
if (fileOld) {
if (fFinalize)
TruncateFile(fileOld, vinfoBlockFile[nLastBlockFile].nSize);
FileCommit(fileOld);
fclose(fileOld);
}
fileOld = OpenUndoFile(posOld);
if (fileOld) {
if (fFinalize)
TruncateFile(fileOld, vinfoBlockFile[nLastBlockFile].nUndoSize);
FileCommit(fileOld);
fclose(fileOld);
}
}
bool FindUndoPos(CValidationState &state, int nFile, CDiskBlockPos &pos, unsigned int nAddSize);
static bool WriteUndoDataForBlock(const CBlockUndo& blockundo, CValidationState& state, CBlockIndex* pindex, const CChainParams& chainparams)
{
// Write undo information to disk
if (pindex->GetUndoPos().IsNull()) {
CDiskBlockPos _pos;
if (!FindUndoPos(state, pindex->nFile, _pos, ::GetSerializeSize(blockundo, SER_DISK, CLIENT_VERSION) + 40))
return error("ConnectBlock(): FindUndoPos failed");
if (!UndoWriteToDisk(blockundo, _pos, pindex->pprev->GetBlockHash(), chainparams.MessageStart()))
return AbortNode(state, "Failed to write undo data");
// update nUndoPos in block index
pindex->nUndoPos = _pos.nPos;
pindex->nStatus |= BLOCK_HAVE_UNDO;
setDirtyBlockIndex.insert(pindex);
}
return true;
}
static CCheckQueue<CScriptCheck> scriptcheckqueue(128);
void ThreadScriptCheck() {
RenameThread("bitcoin-scriptch");
scriptcheckqueue.Thread();
}
// Protected by cs_main
VersionBitsCache versionbitscache;
int32_t ComputeBlockVersion(const CBlockIndex* pindexPrev, const Consensus::Params& params)
{
LOCK(cs_main);
int32_t nVersion = VERSIONBITS_TOP_BITS;
for (int i = 0; i < (int)Consensus::MAX_VERSION_BITS_DEPLOYMENTS; i++) {
ThresholdState state = VersionBitsState(pindexPrev, params, (Consensus::DeploymentPos)i, versionbitscache);
if (state == THRESHOLD_LOCKED_IN || state == THRESHOLD_STARTED) {
nVersion |= VersionBitsMask(params, (Consensus::DeploymentPos)i);
}
}
return nVersion;
}
/**
* Threshold condition checker that triggers when unknown versionbits are seen on the network.
*/
class WarningBitsConditionChecker : public AbstractThresholdConditionChecker
{
private:
int bit;
public:
WarningBitsConditionChecker(int bitIn) : bit(bitIn) {}
int64_t BeginTime(const Consensus::Params& params) const { return 0; }
int64_t EndTime(const Consensus::Params& params) const { return std::numeric_limits<int64_t>::max(); }
int Period(const Consensus::Params& params) const { return params.nMinerConfirmationWindow; }
int Threshold(const Consensus::Params& params) const { return params.nRuleChangeActivationThreshold; }
bool Condition(const CBlockIndex* pindex, const Consensus::Params& params) const
{
return ((pindex->nVersion & VERSIONBITS_TOP_MASK) == VERSIONBITS_TOP_BITS) &&
((pindex->nVersion >> bit) & 1) != 0 &&
((ComputeBlockVersion(pindex->pprev, params) >> bit) & 1) == 0;
}
};
// Protected by cs_main
static ThresholdConditionCache warningcache[VERSIONBITS_NUM_BITS];
static int64_t nTimeCheck = 0;
static int64_t nTimeForks = 0;
static int64_t nTimeVerify = 0;
static int64_t nTimeConnect = 0;
static int64_t nTimeIndex = 0;
static int64_t nTimeCallbacks = 0;
static int64_t nTimeTotal = 0;
bool ConnectBlock(const CBlock& block, CValidationState& state, CBlockIndex* pindex,
CCoinsViewCache& view, const CChainParams& chainparams, bool fJustCheck)
{
AssertLockHeld(cs_main);
int64_t nTimeStart = GetTimeMicros();
// Check it again in case a previous version let a bad block in
if (!CheckBlock(block, state, chainparams.GetConsensus(), !fJustCheck, !fJustCheck))
return error("%s: Consensus::CheckBlock: %s", __func__, FormatStateMessage(state));
// verify that the view's current state corresponds to the previous block
uint256 hashPrevBlock = pindex->pprev == NULL ? uint256() : pindex->pprev->GetBlockHash();
assert(hashPrevBlock == view.GetBestBlock());
// Special case for the genesis block, skipping connection of its transactions
// (its coinbase is unspendable)
if (block.GetHash() == chainparams.GetConsensus().hashGenesisBlock) {
if (!fJustCheck)
view.SetBestBlock(pindex->GetBlockHash());
// return true;
}
bool fScriptChecks = true;
if (!hashAssumeValid.IsNull()) {
// We've been configured with the hash of a block which has been externally verified to have a valid history.
// A suitable default value is included with the software and updated from time to time. Because validity
// relative to a piece of software is an objective fact these defaults can be easily reviewed.
// This setting doesn't force the selection of any particular chain but makes validating some faster by
// effectively caching the result of part of the verification.
BlockMap::const_iterator it = mapBlockIndex.find(hashAssumeValid);
if (it != mapBlockIndex.end()) {
if (it->second->GetAncestor(pindex->nHeight) == pindex &&
pindexBestHeader->GetAncestor(pindex->nHeight) == pindex &&
pindexBestHeader->nChainWork >= UintToArith256(chainparams.GetConsensus().nMinimumChainWork)) {
// This block is a member of the assumed verified chain and an ancestor of the best header.
// The equivalent time check discourages hashpower from extorting the network via DOS attack
// into accepting an invalid block through telling users they must manually set assumevalid.
// Requiring a software change or burying the invalid block, regardless of the setting, makes
// it hard to hide the implication of the demand. This also avoids having release candidates
// that are hardly doing any signature verification at all in testing without having to
// artificially set the default assumed verified block further back.
// The test against nMinimumChainWork prevents the skipping when denied access to any chain at
// least as good as the expected chain.
fScriptChecks = (GetBlockProofEquivalentTime(*pindexBestHeader, *pindex, *pindexBestHeader, chainparams.GetConsensus()) <= 60 * 60 * 24 * 7 * 2);
}
}
}
int64_t nTime1 = GetTimeMicros(); nTimeCheck += nTime1 - nTimeStart;
LogPrint("bench", " - Sanity checks: %.2fms [%.2fs]\n", 0.001 * (nTime1 - nTimeStart), nTimeCheck * 0.000001);
// Do not allow blocks that contain transactions which 'overwrite' older transactions,
// unless those are already completely spent.
// If such overwrites are allowed, coinbases and transactions depending upon those
// can be duplicated to remove the ability to spend the first instance -- even after
// being sent to another address.
// See BIP30 and http://r6.ca/blog/20120206T005236Z.html for more information.
// This logic is not necessary for memory pool transactions, as AcceptToMemoryPool
// already refuses previously-known transaction ids entirely.
// This rule was originally applied to all blocks with a timestamp after March 15, 2012, 0:00 UTC.
// Now that the whole chain is irreversibly beyond that time it is applied to all blocks except the
// two in the chain that violate it. This prevents exploiting the issue against nodes during their
// initial block download.
bool fEnforceBIP30 = true;
//(!pindex->phashBlock) || // Enforce on CreateNewBlock invocations which don't have a hash.
// !((pindex->nHeight==91842 && pindex->GetBlockHash() == uint256S("0x00000000000a4d0a398161ffc163c503763b1f4360639393e0e4c8e300e0caec")) ||
// (pindex->nHeight==91880 && pindex->GetBlockHash() == uint256S("0x00000000000743f190a18c5577a3c2d2a1f610ae9601ac046a38084ccb7cd721")));
// Once BIP34 activated it was not possible to create new duplicate coinbases and thus other than starting
// with the 2 existing duplicate coinbase pairs, not possible to create overwriting txs. But by the
// time BIP34 activated, in each of the existing pairs the duplicate coinbase had overwritten the first
// before the first had been spent. Since those coinbases are sufficiently buried its no longer possible to create further
// duplicate transactions descending from the known pairs either.
// If we're on the known chain at height greater than where BIP34 activated, we can save the db accesses needed for the BIP30 check.
if (block.GetHash() != chainparams.GetConsensus().hashGenesisBlock) {
assert(pindex->pprev);
}
CBlockIndex *pindexBIP34height = pindex->pprev->GetAncestor(chainparams.GetConsensus().BIP34Height);
//Only continue to enforce if we're below BIP34 activation height or the block hash at that height doesn't correspond.
fEnforceBIP30 = fEnforceBIP30 && (!pindexBIP34height || !(pindexBIP34height->GetBlockHash() == chainparams.GetConsensus().BIP34Hash));
if (fEnforceBIP30) {
for (const auto& tx : block.vtx) {
const CCoins* coins = view.AccessCoins(tx->GetHash());
if (coins && !coins->IsPruned())
return state.DoS(100, error("ConnectBlock(): tried to overwrite transaction"),
REJECT_INVALID, "bad-txns-BIP30");
}
}
// BIP16 didn't become active until Oct 1 2012
int64_t nBIP16SwitchTime = 1349049600;
bool fStrictPayToScriptHash = (pindex->GetBlockTime() >= nBIP16SwitchTime);
unsigned int flags = fStrictPayToScriptHash ? SCRIPT_VERIFY_P2SH : SCRIPT_VERIFY_NONE;
// Start enforcing the DERSIG (BIP66) rule
if (pindex->nHeight >= chainparams.GetConsensus().BIP66Height) {
flags |= SCRIPT_VERIFY_DERSIG;
}
// Start enforcing CHECKLOCKTIMEVERIFY (BIP65) rule
if (pindex->nHeight >= chainparams.GetConsensus().BIP65Height) {
flags |= SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY;
}
// Start enforcing BIP68 (sequence locks) and BIP112 (CHECKSEQUENCEVERIFY) using versionbits logic.
int nLockTimeFlags = 0;
if (VersionBitsState(pindex->pprev, chainparams.GetConsensus(), Consensus::DEPLOYMENT_CSV, versionbitscache) == THRESHOLD_ACTIVE) {
flags |= SCRIPT_VERIFY_CHECKSEQUENCEVERIFY;
nLockTimeFlags |= LOCKTIME_VERIFY_SEQUENCE;
}
// Start enforcing WITNESS rules using versionbits logic.
if (IsWitnessEnabled(pindex->pprev, chainparams.GetConsensus())) {
flags |= SCRIPT_VERIFY_WITNESS;
flags |= SCRIPT_VERIFY_NULLDUMMY;
}
int64_t nTime2 = GetTimeMicros(); nTimeForks += nTime2 - nTime1;
LogPrint("bench", " - Fork checks: %.2fms [%.2fs]\n", 0.001 * (nTime2 - nTime1), nTimeForks * 0.000001);
CBlockUndo blockundo;
CCheckQueueControl<CScriptCheck> control(fScriptChecks && nScriptCheckThreads ? &scriptcheckqueue : NULL);
std::vector<int> prevheights;
CAmount nFees = 0;
int nInputs = 0;
int64_t nSigOpsCost = 0;
CDiskTxPos pos(pindex->GetBlockPos(), GetSizeOfCompactSize(block.vtx.size()));
std::vector<std::pair<uint256, CDiskTxPos> > vPos;
vPos.reserve(block.vtx.size());
blockundo.vtxundo.reserve(block.vtx.size() - 1);
std::vector<PrecomputedTransactionData> txdata;
txdata.reserve(block.vtx.size()); // Required so that pointers to individual PrecomputedTransactionData don't get invalidated
for (unsigned int i = 0; i < block.vtx.size(); i++)
{
const CTransaction &tx = *(block.vtx[i]);
nInputs += tx.vin.size();
if (!tx.IsCoinBase())
{
if (!view.HaveInputs(tx))
return state.DoS(100, error("ConnectBlock(): inputs missing/spent"),
REJECT_INVALID, "bad-txns-inputs-missingorspent");
// Check that transaction is BIP68 final
// BIP68 lock checks (as opposed to nLockTime checks) must
// be in ConnectBlock because they require the UTXO set
prevheights.resize(tx.vin.size());
for (size_t j = 0; j < tx.vin.size(); j++) {
prevheights[j] = view.AccessCoins(tx.vin[j].prevout.hash)->nHeight;
}
if (!SequenceLocks(tx, nLockTimeFlags, &prevheights, *pindex)) {
return state.DoS(100, error("%s: contains a non-BIP68-final transaction", __func__),
REJECT_INVALID, "bad-txns-nonfinal");
}
}
// GetTransactionSigOpCost counts 3 types of sigops:
// * legacy (always)
// * p2sh (when P2SH enabled in flags and excludes coinbase)
// * witness (when witness enabled in flags and excludes coinbase)
nSigOpsCost += GetTransactionSigOpCost(tx, view, flags);
if (nSigOpsCost > MAX_BLOCK_SIGOPS_COST)
return state.DoS(100, error("ConnectBlock(): too many sigops"),
REJECT_INVALID, "bad-blk-sigops");
txdata.emplace_back(tx);
if (!tx.IsCoinBase())
{
nFees += view.GetValueIn(tx)-tx.GetValueOut();
std::vector<CScriptCheck> vChecks;
bool fCacheResults = fJustCheck; /* Don't cache results if we're actually connecting blocks (still consult the cache, though) */
if (!CheckInputs(tx, state, view, fScriptChecks, flags, fCacheResults, txdata[i], nScriptCheckThreads ? &vChecks : NULL))
return error("ConnectBlock(): CheckInputs on %s failed with %s",
tx.GetHash().ToString(), FormatStateMessage(state));
control.Add(vChecks);
}
CTxUndo undoDummy;
if (i > 0) {
blockundo.vtxundo.push_back(CTxUndo());
}
UpdateCoins(tx, view, i == 0 ? undoDummy : blockundo.vtxundo.back(), pindex->nHeight);
vPos.push_back(std::make_pair(tx.GetHash(), pos));
pos.nTxOffset += ::GetSerializeSize(tx, SER_DISK, CLIENT_VERSION);
}
int64_t nTime3 = GetTimeMicros(); nTimeConnect += nTime3 - nTime2;
LogPrint("bench", " - Connect %u transactions: %.2fms (%.3fms/tx, %.3fms/txin) [%.2fs]\n", (unsigned)block.vtx.size(), 0.001 * (nTime3 - nTime2), 0.001 * (nTime3 - nTime2) / block.vtx.size(), nInputs <= 1 ? 0 : 0.001 * (nTime3 - nTime2) / (nInputs-1), nTimeConnect * 0.000001);
CAmount blockReward = nFees + GetBlockSubsidy(pindex->nHeight, chainparams.GetConsensus());
if (block.vtx[0]->GetValueOut() > blockReward)
return state.DoS(100,
error("ConnectBlock(): coinbase pays too much (actual=%d vs limit=%d)",
block.vtx[0]->GetValueOut(), blockReward),
REJECT_INVALID, "bad-cb-amount");
if (!control.Wait())
return state.DoS(100, false);
int64_t nTime4 = GetTimeMicros(); nTimeVerify += nTime4 - nTime2;
LogPrint("bench", " - Verify %u txins: %.2fms (%.3fms/txin) [%.2fs]\n", nInputs - 1, 0.001 * (nTime4 - nTime2), nInputs <= 1 ? 0 : 0.001 * (nTime4 - nTime2) / (nInputs-1), nTimeVerify * 0.000001);
if (fJustCheck)
return true;
if (!WriteUndoDataForBlock(blockundo, state, pindex, chainparams))
return false;
// Write undo information to disk
if (pindex->GetUndoPos().IsNull() || !pindex->IsValid(BLOCK_VALID_SCRIPTS))
{
if (pindex->GetUndoPos().IsNull()) {
CDiskBlockPos _pos;
if (!FindUndoPos(state, pindex->nFile, _pos, ::GetSerializeSize(blockundo, SER_DISK, CLIENT_VERSION) + 40))
return error("ConnectBlock(): FindUndoPos failed");
if (!UndoWriteToDisk(blockundo, _pos, pindex->pprev->GetBlockHash(), chainparams.MessageStart()))
return AbortNode(state, "Failed to write undo data");
// update nUndoPos in block index
pindex->nUndoPos = _pos.nPos;
pindex->nStatus |= BLOCK_HAVE_UNDO;
}
pindex->RaiseValidity(BLOCK_VALID_SCRIPTS);
setDirtyBlockIndex.insert(pindex);
}
if (fTxIndex)
if (!pblocktree->WriteTxIndex(vPos))
return AbortNode(state, "Failed to write transaction index");
// add this block to the view's block chain
view.SetBestBlock(pindex->GetBlockHash());
int64_t nTime5 = GetTimeMicros(); nTimeIndex += nTime5 - nTime4;
LogPrint("bench", " - Index writing: %.2fms [%.2fs]\n", 0.001 * (nTime5 - nTime4), nTimeIndex * 0.000001);
// Watch for changes to the previous coinbase transaction.
static uint256 hashPrevBestCoinBase;
GetMainSignals().UpdatedTransaction(hashPrevBestCoinBase);
hashPrevBestCoinBase = block.vtx[0]->GetHash();
int64_t nTime6 = GetTimeMicros(); nTimeCallbacks += nTime6 - nTime5;
LogPrint("bench", " - Callbacks: %.2fms [%.2fs]\n", 0.001 * (nTime6 - nTime5), nTimeCallbacks * 0.000001);
return true;
}
/**
* Update the on-disk chain state.
* The caches and indexes are flushed depending on the mode we're called with
* if they're too large, if it's been a while since the last write,
* or always and in all cases if we're in prune mode and are deleting files.
*/
bool static FlushStateToDisk(CValidationState &state, FlushStateMode mode, int nManualPruneHeight) {
int64_t nMempoolUsage = mempool.DynamicMemoryUsage();
const CChainParams& chainparams = Params();
LOCK2(cs_main, cs_LastBlockFile);
static int64_t nLastWrite = 0;
static int64_t nLastFlush = 0;
static int64_t nLastSetChain = 0;
std::set<int> setFilesToPrune;
bool fFlushForPrune = false;
try {
if (fPruneMode && (fCheckForPruning || nManualPruneHeight > 0) && !fReindex) {
if (nManualPruneHeight > 0) {
FindFilesToPruneManual(setFilesToPrune, nManualPruneHeight);
} else {
FindFilesToPrune(setFilesToPrune, chainparams.PruneAfterHeight());
fCheckForPruning = false;
}
if (!setFilesToPrune.empty()) {
fFlushForPrune = true;
if (!fHavePruned) {
pblocktree->WriteFlag("prunedblockfiles", true);
fHavePruned = true;
}
}
}
int64_t nNow = GetTimeMicros();
// Avoid writing/flushing immediately after startup.
if (nLastWrite == 0) {
nLastWrite = nNow;
}
if (nLastFlush == 0) {
nLastFlush = nNow;
}
if (nLastSetChain == 0) {
nLastSetChain = nNow;
}
int64_t nMempoolSizeMax = GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000;
int64_t cacheSize = pcoinsTip->DynamicMemoryUsage() * DB_PEAK_USAGE_FACTOR;
int64_t nTotalSpace = nCoinCacheUsage + std::max<int64_t>(nMempoolSizeMax - nMempoolUsage, 0);
// The cache is large and we're within 10% and 200 MiB or 50% and 50MiB of the limit, but we have time now (not in the middle of a block processing).
bool fCacheLarge = mode == FLUSH_STATE_PERIODIC && cacheSize > std::min(std::max(nTotalSpace / 2, nTotalSpace - MIN_BLOCK_COINSDB_USAGE * 1024 * 1024),
std::max((9 * nTotalSpace) / 10, nTotalSpace - MAX_BLOCK_COINSDB_USAGE * 1024 * 1024));
// The cache is over the limit, we have to write now.
bool fCacheCritical = mode == FLUSH_STATE_IF_NEEDED && cacheSize > nTotalSpace;
// It's been a while since we wrote the block index to disk. Do this frequently, so we don't need to redownload after a crash.
bool fPeriodicWrite = mode == FLUSH_STATE_PERIODIC && nNow > nLastWrite + (int64_t)DATABASE_WRITE_INTERVAL * 1000000;
// It's been very long since we flushed the cache. Do this infrequently, to optimize cache usage.
bool fPeriodicFlush = mode == FLUSH_STATE_PERIODIC && nNow > nLastFlush + (int64_t)DATABASE_FLUSH_INTERVAL * 1000000;
// Combine all conditions that result in a full cache flush.
bool fDoFullFlush = (mode == FLUSH_STATE_ALWAYS) || fCacheLarge || fCacheCritical || fPeriodicFlush || fFlushForPrune;
// Write blocks and block index to disk.
if (fDoFullFlush || fPeriodicWrite) {
// Depend on nMinDiskSpace to ensure we can write block index
if (!CheckDiskSpace(0))
return state.Error("out of disk space");
// First make sure all block and undo data is flushed to disk.
FlushBlockFile();
// Then update all block file information (which may refer to block and undo files).
{
std::vector<std::pair<int, const CBlockFileInfo*> > vFiles;
vFiles.reserve(setDirtyFileInfo.size());
for (std::set<int>::iterator it = setDirtyFileInfo.begin(); it != setDirtyFileInfo.end(); ) {
vFiles.push_back(std::make_pair(*it, &vinfoBlockFile[*it]));
setDirtyFileInfo.erase(it++);
}
std::vector<const CBlockIndex*> vBlocks;
vBlocks.reserve(setDirtyBlockIndex.size());
for (std::set<CBlockIndex*>::iterator it = setDirtyBlockIndex.begin(); it != setDirtyBlockIndex.end(); ) {
vBlocks.push_back(*it);
setDirtyBlockIndex.erase(it++);
}
if (!pblocktree->WriteBatchSync(vFiles, nLastBlockFile, vBlocks)) {
return AbortNode(state, "Failed to write to block index database");
}
}
// Finally remove any pruned files
if (fFlushForPrune)
UnlinkPrunedFiles(setFilesToPrune);
nLastWrite = nNow;
}
// Flush best chain related state. This can only be done if the blocks / block index write was also done.
if (fDoFullFlush) {
// Typical CCoins structures on disk are around 128 bytes in size.
// Pushing a new one to the database can cause it to be written
// twice (once in the log, and once in the tables). This is already
// an overestimation, as most will delete an existing entry or
// overwrite one. Still, use a conservative safety factor of 2.
if (!CheckDiskSpace(128 * 2 * 2 * pcoinsTip->GetCacheSize()))
return state.Error("out of disk space");
// Flush the chainstate (which may refer to block index entries).
if (!pcoinsTip->Flush())
return AbortNode(state, "Failed to write to coin database");
nLastFlush = nNow;
}
if (fDoFullFlush || ((mode == FLUSH_STATE_ALWAYS || mode == FLUSH_STATE_PERIODIC) && nNow > nLastSetChain + (int64_t)DATABASE_WRITE_INTERVAL * 1000000)) {
// Update best block in wallet (so we can detect restored wallets).
GetMainSignals().SetBestChain(chainActive.GetLocator());
nLastSetChain = nNow;
}
} catch (const std::runtime_error& e) {
return AbortNode(state, std::string("System error while flushing: ") + e.what());
}
return true;
}
void FlushStateToDisk() {
CValidationState state;
FlushStateToDisk(state, FLUSH_STATE_ALWAYS);
}
void PruneAndFlush() {
CValidationState state;
fCheckForPruning = true;
FlushStateToDisk(state, FLUSH_STATE_NONE);
}
/** Update chainActive and related internal data structures. */
void static UpdateTip(CBlockIndex *pindexNew, const CChainParams& chainParams) {
chainActive.SetTip(pindexNew);
// New best block
mempool.AddTransactionsUpdated(1);
cvBlockChange.notify_all();
static bool fWarned = false;
std::vector<std::string> warningMessages;
if (!IsInitialBlockDownload())
{
int nUpgraded = 0;
const CBlockIndex* pindex = chainActive.Tip();
for (int bit = 0; bit < VERSIONBITS_NUM_BITS; bit++) {
WarningBitsConditionChecker checker(bit);
ThresholdState state = checker.GetStateFor(pindex, chainParams.GetConsensus(), warningcache[bit]);
if (state == THRESHOLD_ACTIVE || state == THRESHOLD_LOCKED_IN) {
if (state == THRESHOLD_ACTIVE) {
std::string strWarning = strprintf(_("Warning: unknown new rules activated (versionbit %i)"), bit);
SetMiscWarning(strWarning);
if (!fWarned) {
AlertNotify(strWarning);
fWarned = true;
}
} else {
warningMessages.push_back(strprintf("unknown new rules are about to activate (versionbit %i)", bit));
}
}
}
// Check the version of the last 100 blocks to see if we need to upgrade:
for (int i = 0; i < 100 && pindex != NULL; i++)
{
int32_t nExpectedVersion = ComputeBlockVersion(pindex->pprev, chainParams.GetConsensus());
if (pindex->nVersion > VERSIONBITS_LAST_OLD_BLOCK_VERSION && (pindex->nVersion & ~nExpectedVersion) != 0)
++nUpgraded;
pindex = pindex->pprev;
}
if (nUpgraded > 0)
warningMessages.push_back(strprintf("%d of last 100 blocks have unexpected version", nUpgraded));
if (nUpgraded > 100/2)
{
std::string strWarning = _("Warning: Unknown block versions being mined! It's possible unknown rules are in effect");
// notify GetWarnings(), called by Qt and the JSON-RPC code to warn the user:
SetMiscWarning(strWarning);
if (!fWarned) {
AlertNotify(strWarning);
fWarned = true;
}
}
}
LogPrintf("%s: new best=%s height=%d version=0x%08x log2_work=%.8g tx=%lu date='%s' progress=%f cache=%.1fMiB(%utx)", __func__,
chainActive.Tip()->GetBlockHash().ToString(), chainActive.Height(), chainActive.Tip()->nVersion,
log(chainActive.Tip()->nChainWork.getdouble())/log(2.0), (unsigned long)chainActive.Tip()->nChainTx,
DateTimeStrFormat("%Y-%m-%d %H:%M:%S", chainActive.Tip()->GetBlockTime()),
GuessVerificationProgress(chainParams.TxData(), chainActive.Tip()), pcoinsTip->DynamicMemoryUsage() * (1.0 / (1<<20)), pcoinsTip->GetCacheSize());
if (!warningMessages.empty())
LogPrintf(" warning='%s'", boost::algorithm::join(warningMessages, ", "));
LogPrintf("\n");
}
/** Disconnect chainActive's tip. You probably want to call mempool.removeForReorg and manually re-limit mempool size after this, with cs_main held. */
bool static DisconnectTip(CValidationState& state, const CChainParams& chainparams, bool fBare = false)
{
CBlockIndex *pindexDelete = chainActive.Tip();
assert(pindexDelete);
// Read block from disk.
CBlock block;
if (!ReadBlockFromDisk(block, pindexDelete, chainparams.GetConsensus()))
return AbortNode(state, "Failed to read block");
// Apply the block atomically to the chain state.
int64_t nStart = GetTimeMicros();
{
CCoinsViewCache view(pcoinsTip);
if (!DisconnectBlock(block, state, pindexDelete, view))
return error("DisconnectTip(): DisconnectBlock %s failed", pindexDelete->GetBlockHash().ToString());
bool flushed = view.Flush();
assert(flushed);
}
LogPrint("bench", "- Disconnect block: %.2fms\n", (GetTimeMicros() - nStart) * 0.001);
// Write the chain state to disk, if necessary.
if (!FlushStateToDisk(state, FLUSH_STATE_IF_NEEDED))
return false;
if (!fBare) {
// Resurrect mempool transactions from the disconnected block.
std::vector<uint256> vHashUpdate;
for (const auto& it : block.vtx) {
const CTransaction& tx = *it;
// ignore validation errors in resurrected transactions
CValidationState stateDummy;
if (tx.IsCoinBase() || !AcceptToMemoryPool(mempool, stateDummy, it, false, NULL, NULL, true)) {
mempool.removeRecursive(tx, MemPoolRemovalReason::REORG);
} else if (mempool.exists(tx.GetHash())) {
vHashUpdate.push_back(tx.GetHash());
}
}
// AcceptToMemoryPool/addUnchecked all assume that new mempool entries have
// no in-mempool children, which is generally not true when adding
// previously-confirmed transactions back to the mempool.
// UpdateTransactionsFromBlock finds descendants of any transactions in this
// block that were added back and cleans up the mempool state.
mempool.UpdateTransactionsFromBlock(vHashUpdate);
}
// Update chainActive and related variables.
UpdateTip(pindexDelete->pprev, chainparams);
// Let wallets know transactions went from 1-confirmed to
// 0-confirmed or conflicted:
for (const auto& tx : block.vtx) {
GetMainSignals().SyncTransaction(*tx, pindexDelete->pprev, CMainSignals::SYNC_TRANSACTION_NOT_IN_BLOCK);
}
return true;
}
static int64_t nTimeReadFromDisk = 0;
static int64_t nTimeConnectTotal = 0;
static int64_t nTimeFlush = 0;
static int64_t nTimeChainState = 0;
static int64_t nTimePostConnect = 0;
/**
* Used to track blocks whose transactions were applied to the UTXO state as a
* part of a single ActivateBestChainStep call.
*/
struct ConnectTrace {
std::vector<std::pair<CBlockIndex*, std::shared_ptr<const CBlock> > > blocksConnected;
};
/**
* Connect a new block to chainActive. pblock is either NULL or a pointer to a CBlock
* corresponding to pindexNew, to bypass loading it again from disk.
*
* The block is always added to connectTrace (either after loading from disk or by copying
* pblock) - if that is not intended, care must be taken to remove the last entry in
* blocksConnected in case of failure.
*/
bool static ConnectTip(CValidationState& state, const CChainParams& chainparams, CBlockIndex* pindexNew, const std::shared_ptr<const CBlock>& pblock, ConnectTrace& connectTrace)
{
assert(pindexNew->pprev == chainActive.Tip());
// Read block from disk.
int64_t nTime1 = GetTimeMicros();
if (!pblock) {
std::shared_ptr<CBlock> pblockNew = std::make_shared<CBlock>();
connectTrace.blocksConnected.emplace_back(pindexNew, pblockNew);
if (!ReadBlockFromDisk(*pblockNew, pindexNew, chainparams.GetConsensus()))
return AbortNode(state, "Failed to read block");
} else {
connectTrace.blocksConnected.emplace_back(pindexNew, pblock);
}
const CBlock& blockConnecting = *connectTrace.blocksConnected.back().second;
// Apply the block atomically to the chain state.
int64_t nTime2 = GetTimeMicros(); nTimeReadFromDisk += nTime2 - nTime1;
int64_t nTime3;
LogPrint("bench", " - Load block from disk: %.2fms [%.2fs]\n", (nTime2 - nTime1) * 0.001, nTimeReadFromDisk * 0.000001);
{
CCoinsViewCache view(pcoinsTip);
bool rv = ConnectBlock(blockConnecting, state, pindexNew, view, chainparams);
GetMainSignals().BlockChecked(blockConnecting, state);
if (!rv) {
if (state.IsInvalid())
InvalidBlockFound(pindexNew, state);
return error("ConnectTip(): ConnectBlock %s failed", pindexNew->GetBlockHash().ToString());
}
nTime3 = GetTimeMicros(); nTimeConnectTotal += nTime3 - nTime2;
LogPrint("bench", " - Connect total: %.2fms [%.2fs]\n", (nTime3 - nTime2) * 0.001, nTimeConnectTotal * 0.000001);
bool flushed = view.Flush();
assert(flushed);
}
int64_t nTime4 = GetTimeMicros(); nTimeFlush += nTime4 - nTime3;
LogPrint("bench", " - Flush: %.2fms [%.2fs]\n", (nTime4 - nTime3) * 0.001, nTimeFlush * 0.000001);
// Write the chain state to disk, if necessary.
if (!FlushStateToDisk(state, FLUSH_STATE_IF_NEEDED))
return false;
int64_t nTime5 = GetTimeMicros(); nTimeChainState += nTime5 - nTime4;
LogPrint("bench", " - Writing chainstate: %.2fms [%.2fs]\n", (nTime5 - nTime4) * 0.001, nTimeChainState * 0.000001);
// Remove conflicting transactions from the mempool.;
mempool.removeForBlock(blockConnecting.vtx, pindexNew->nHeight);
// Update chainActive & related variables.
UpdateTip(pindexNew, chainparams);
int64_t nTime6 = GetTimeMicros(); nTimePostConnect += nTime6 - nTime5; nTimeTotal += nTime6 - nTime1;
LogPrint("bench", " - Connect postprocess: %.2fms [%.2fs]\n", (nTime6 - nTime5) * 0.001, nTimePostConnect * 0.000001);
LogPrint("bench", "- Connect block: %.2fms [%.2fs]\n", (nTime6 - nTime1) * 0.001, nTimeTotal * 0.000001);
return true;
}
/**
* Return the tip of the chain with the most work in it, that isn't
* known to be invalid (it's however far from certain to be valid).
*/
static CBlockIndex* FindMostWorkChain() {
do {
CBlockIndex *pindexNew = NULL;
// Find the best candidate header.
{
std::set<CBlockIndex*, CBlockIndexWorkComparator>::reverse_iterator it = setBlockIndexCandidates.rbegin();
if (it == setBlockIndexCandidates.rend())
return NULL;
pindexNew = *it;
}
// Check whether all blocks on the path between the currently active chain and the candidate are valid.
// Just going until the active chain is an optimization, as we know all blocks in it are valid already.
CBlockIndex *pindexTest = pindexNew;
bool fInvalidAncestor = false;
while (pindexTest && !chainActive.Contains(pindexTest)) {
assert(pindexTest->nChainTx || pindexTest->nHeight == 0);
// Pruned nodes may have entries in setBlockIndexCandidates for
// which block files have been deleted. Remove those as candidates
// for the most work chain if we come across them; we can't switch
// to a chain unless we have all the non-active-chain parent blocks.
bool fFailedChain = pindexTest->nStatus & BLOCK_FAILED_MASK;
bool fMissingData = !(pindexTest->nStatus & BLOCK_HAVE_DATA);
if (fFailedChain || fMissingData) {
// Candidate chain is not usable (either invalid or missing data)
if (fFailedChain && (pindexBestInvalid == NULL || pindexNew->nChainWork > pindexBestInvalid->nChainWork))
pindexBestInvalid = pindexNew;
CBlockIndex *pindexFailed = pindexNew;
// Remove the entire chain from the set.
while (pindexTest != pindexFailed) {
if (fFailedChain) {
pindexFailed->nStatus |= BLOCK_FAILED_CHILD;
} else if (fMissingData) {
// If we're missing data, then add back to mapBlocksUnlinked,
// so that if the block arrives in the future we can try adding
// to setBlockIndexCandidates again.
mapBlocksUnlinked.insert(std::make_pair(pindexFailed->pprev, pindexFailed));
}
setBlockIndexCandidates.erase(pindexFailed);
pindexFailed = pindexFailed->pprev;
}
setBlockIndexCandidates.erase(pindexTest);
fInvalidAncestor = true;
break;
}
pindexTest = pindexTest->pprev;
}
if (!fInvalidAncestor)
return pindexNew;
} while(true);
}
/** Delete all entries in setBlockIndexCandidates that are worse than the current tip. */
static void PruneBlockIndexCandidates() {
// Note that we can't delete the current block itself, as we may need to return to it later in case a
// reorganization to a better block fails.
std::set<CBlockIndex*, CBlockIndexWorkComparator>::iterator it = setBlockIndexCandidates.begin();
while (it != setBlockIndexCandidates.end() && setBlockIndexCandidates.value_comp()(*it, chainActive.Tip())) {
setBlockIndexCandidates.erase(it++);
}
// Either the current tip or a successor of it we're working towards is left in setBlockIndexCandidates.
assert(!setBlockIndexCandidates.empty());
}
/**
* Try to make some progress towards making pindexMostWork the active block.
* pblock is either NULL or a pointer to a CBlock corresponding to pindexMostWork.
*/
static bool ActivateBestChainStep(CValidationState& state, const CChainParams& chainparams, CBlockIndex* pindexMostWork, const std::shared_ptr<const CBlock>& pblock, bool& fInvalidFound, ConnectTrace& connectTrace)
{
AssertLockHeld(cs_main);
const CBlockIndex *pindexOldTip = chainActive.Tip();
const CBlockIndex *pindexFork = chainActive.FindFork(pindexMostWork);
// Disconnect active blocks which are no longer in the best chain.
bool fBlocksDisconnected = false;
while (chainActive.Tip() && chainActive.Tip() != pindexFork) {
if (!DisconnectTip(state, chainparams))
return false;
fBlocksDisconnected = true;
}
// Build list of new blocks to connect.
std::vector<CBlockIndex*> vpindexToConnect;
bool fContinue = true;
int nHeight = pindexFork ? pindexFork->nHeight : -1;
while (fContinue && nHeight != pindexMostWork->nHeight) {
// Don't iterate the entire list of potential improvements toward the best tip, as we likely only need
// a few blocks along the way.
int nTargetHeight = std::min(nHeight + 32, pindexMostWork->nHeight);
vpindexToConnect.clear();
vpindexToConnect.reserve(nTargetHeight - nHeight);
CBlockIndex *pindexIter = pindexMostWork->GetAncestor(nTargetHeight);
while (pindexIter && pindexIter->nHeight != nHeight) {
vpindexToConnect.push_back(pindexIter);
pindexIter = pindexIter->pprev;
}
nHeight = nTargetHeight;
// Connect new blocks.
BOOST_REVERSE_FOREACH(CBlockIndex *pindexConnect, vpindexToConnect) {
if (!ConnectTip(state, chainparams, pindexConnect, pindexConnect == pindexMostWork ? pblock : std::shared_ptr<const CBlock>(), connectTrace)) {
if (state.IsInvalid()) {
// The block violates a consensus rule.
if (!state.CorruptionPossible())
InvalidChainFound(vpindexToConnect.back());
state = CValidationState();
fInvalidFound = true;
fContinue = false;
// If we didn't actually connect the block, don't notify listeners about it
connectTrace.blocksConnected.pop_back();
break;
} else {
// A system error occurred (disk space, database error, ...).
return false;
}
} else {
PruneBlockIndexCandidates();
if (!pindexOldTip || chainActive.Tip()->nChainWork > pindexOldTip->nChainWork) {
// We're in a better position than we were. Return temporarily to release the lock.
fContinue = false;
break;
}
}
}
}
if (fBlocksDisconnected) {
mempool.removeForReorg(pcoinsTip, chainActive.Tip()->nHeight + 1, STANDARD_LOCKTIME_VERIFY_FLAGS);
LimitMempoolSize(mempool, GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000, GetArg("-mempoolexpiry", DEFAULT_MEMPOOL_EXPIRY) * 60 * 60);
}
mempool.check(pcoinsTip);
// Callbacks/notifications for a new best chain.
if (fInvalidFound)
CheckForkWarningConditionsOnNewFork(vpindexToConnect.back());
else
CheckForkWarningConditions();
return true;
}
static void NotifyHeaderTip() {
bool fNotify = false;
bool fInitialBlockDownload = false;
static CBlockIndex* pindexHeaderOld = NULL;
CBlockIndex* pindexHeader = NULL;
{
LOCK(cs_main);
pindexHeader = pindexBestHeader;
if (pindexHeader != pindexHeaderOld) {
fNotify = true;
fInitialBlockDownload = IsInitialBlockDownload();
pindexHeaderOld = pindexHeader;
}
}
// Send block tip changed notifications without cs_main
if (fNotify) {
uiInterface.NotifyHeaderTip(fInitialBlockDownload, pindexHeader);
}
}
/**
* Make the best chain active, in multiple steps. The result is either failure
* or an activated best chain. pblock is either NULL or a pointer to a block
* that is already loaded (to avoid loading it again from disk).
*/
bool ActivateBestChain(CValidationState &state, const CChainParams& chainparams, std::shared_ptr<const CBlock> pblock) {
// Note that while we're often called here from ProcessNewBlock, this is
// far from a guarantee. Things in the P2P/RPC will often end up calling
// us in the middle of ProcessNewBlock - do not assume pblock is set
// sanely for performance or correctness!
CBlockIndex *pindexMostWork = NULL;
CBlockIndex *pindexNewTip = NULL;
do {
boost::this_thread::interruption_point();
if (ShutdownRequested())
break;
const CBlockIndex *pindexFork;
ConnectTrace connectTrace;
bool fInitialDownload;
{
LOCK(cs_main);
{ // TODO: Tempoarily ensure that mempool removals are notified before
// connected transactions. This shouldn't matter, but the abandoned
// state of transactions in our wallet is currently cleared when we
// receive another notification and there is a race condition where
// notification of a connected conflict might cause an outside process
// to abandon a transaction and then have it inadvertantly cleared by
// the notification that the conflicted transaction was evicted.
MemPoolConflictRemovalTracker mrt(mempool);
CBlockIndex *pindexOldTip = chainActive.Tip();
if (pindexMostWork == NULL) {
pindexMostWork = FindMostWorkChain();
}
// Whether we have anything to do at all.
if (pindexMostWork == NULL || pindexMostWork == chainActive.Tip())
return true;
bool fInvalidFound = false;
std::shared_ptr<const CBlock> nullBlockPtr;
if (!ActivateBestChainStep(state, chainparams, pindexMostWork, pblock && pblock->GetHash() == pindexMostWork->GetBlockHash() ? pblock : nullBlockPtr, fInvalidFound, connectTrace))
return false;
if (fInvalidFound) {
// Wipe cache, we may need another branch now.
pindexMostWork = NULL;
}
pindexNewTip = chainActive.Tip();
pindexFork = chainActive.FindFork(pindexOldTip);
fInitialDownload = IsInitialBlockDownload();
// throw all transactions though the signal-interface
} // MemPoolConflictRemovalTracker destroyed and conflict evictions are notified
// Transactions in the connnected block are notified
for (const auto& pair : connectTrace.blocksConnected) {
assert(pair.second);
const CBlock& block = *(pair.second);
for (unsigned int i = 0; i < block.vtx.size(); i++)
GetMainSignals().SyncTransaction(*block.vtx[i], pair.first, i);
}
}
// When we reach this point, we switched to a new tip (stored in pindexNewTip).
// Notifications/callbacks that can run without cs_main
// Notify external listeners about the new tip.
GetMainSignals().UpdatedBlockTip(pindexNewTip, pindexFork, fInitialDownload);
// Always notify the UI if a new block tip was connected
if (pindexFork != pindexNewTip) {
uiInterface.NotifyBlockTip(fInitialDownload, pindexNewTip);
}
} while (pindexNewTip != pindexMostWork);
CheckBlockIndex(chainparams.GetConsensus());
// Write changes periodically to disk, after relay.
if (!FlushStateToDisk(state, FLUSH_STATE_PERIODIC)) {
return false;
}
return true;
}
bool PreciousBlock(CValidationState& state, const CChainParams& params, CBlockIndex *pindex)
{
{
LOCK(cs_main);
if (pindex->nChainWork < chainActive.Tip()->nChainWork) {
// Nothing to do, this block is not at the tip.
return true;
}
if (chainActive.Tip()->nChainWork > nLastPreciousChainwork) {
// The chain has been extended since the last call, reset the counter.
nBlockReverseSequenceId = -1;
}
nLastPreciousChainwork = chainActive.Tip()->nChainWork;
setBlockIndexCandidates.erase(pindex);
pindex->nSequenceId = nBlockReverseSequenceId;
if (nBlockReverseSequenceId > std::numeric_limits<int32_t>::min()) {
// We can't keep reducing the counter if somebody really wants to
// call preciousblock 2**31-1 times on the same set of tips...
nBlockReverseSequenceId--;
}
if (pindex->IsValid(BLOCK_VALID_TRANSACTIONS) && pindex->nChainTx) {
setBlockIndexCandidates.insert(pindex);
PruneBlockIndexCandidates();
}
}
return ActivateBestChain(state, params);
}
bool InvalidateBlock(CValidationState& state, const CChainParams& chainparams, CBlockIndex *pindex)
{
AssertLockHeld(cs_main);
// Mark the block itself as invalid.
pindex->nStatus |= BLOCK_FAILED_VALID;
setDirtyBlockIndex.insert(pindex);
setBlockIndexCandidates.erase(pindex);
while (chainActive.Contains(pindex)) {
CBlockIndex *pindexWalk = chainActive.Tip();
pindexWalk->nStatus |= BLOCK_FAILED_CHILD;
setDirtyBlockIndex.insert(pindexWalk);
setBlockIndexCandidates.erase(pindexWalk);
// ActivateBestChain considers blocks already in chainActive
// unconditionally valid already, so force disconnect away from it.
if (!DisconnectTip(state, chainparams)) {
mempool.removeForReorg(pcoinsTip, chainActive.Tip()->nHeight + 1, STANDARD_LOCKTIME_VERIFY_FLAGS);
return false;
}
}
LimitMempoolSize(mempool, GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000, GetArg("-mempoolexpiry", DEFAULT_MEMPOOL_EXPIRY) * 60 * 60);
// The resulting new best tip may not be in setBlockIndexCandidates anymore, so
// add it again.
BlockMap::iterator it = mapBlockIndex.begin();
while (it != mapBlockIndex.end()) {
if (it->second->IsValid(BLOCK_VALID_TRANSACTIONS) && it->second->nChainTx && !setBlockIndexCandidates.value_comp()(it->second, chainActive.Tip())) {
setBlockIndexCandidates.insert(it->second);
}
it++;
}
InvalidChainFound(pindex);
mempool.removeForReorg(pcoinsTip, chainActive.Tip()->nHeight + 1, STANDARD_LOCKTIME_VERIFY_FLAGS);
uiInterface.NotifyBlockTip(IsInitialBlockDownload(), pindex->pprev);
return true;
}
bool ResetBlockFailureFlags(CBlockIndex *pindex) {
AssertLockHeld(cs_main);
int nHeight = pindex->nHeight;
// Remove the invalidity flag from this block and all its descendants.
BlockMap::iterator it = mapBlockIndex.begin();
while (it != mapBlockIndex.end()) {
if (!it->second->IsValid() && it->second->GetAncestor(nHeight) == pindex) {
it->second->nStatus &= ~BLOCK_FAILED_MASK;
setDirtyBlockIndex.insert(it->second);
if (it->second->IsValid(BLOCK_VALID_TRANSACTIONS) && it->second->nChainTx && setBlockIndexCandidates.value_comp()(chainActive.Tip(), it->second)) {
setBlockIndexCandidates.insert(it->second);
}
if (it->second == pindexBestInvalid) {
// Reset invalid block marker if it was pointing to one of those.
pindexBestInvalid = NULL;
}
}
it++;
}
// Remove the invalidity flag from all ancestors too.
while (pindex != NULL) {
if (pindex->nStatus & BLOCK_FAILED_MASK) {
pindex->nStatus &= ~BLOCK_FAILED_MASK;
setDirtyBlockIndex.insert(pindex);
}
pindex = pindex->pprev;
}
return true;
}
CBlockIndex* AddToBlockIndex(const CBlockHeader& block)
{
// Check for duplicate
uint256 hash = block.GetHash();
BlockMap::iterator it = mapBlockIndex.find(hash);
if (it != mapBlockIndex.end())
return it->second;
// Construct new block index object
CBlockIndex* pindexNew = new CBlockIndex(block);
assert(pindexNew);
// We assign the sequence id to blocks only when the full data is available,
// to avoid miners withholding blocks but broadcasting headers, to get a
// competitive advantage.
pindexNew->nSequenceId = 0;
BlockMap::iterator mi = mapBlockIndex.insert(std::make_pair(hash, pindexNew)).first;
pindexNew->phashBlock = &((*mi).first);
BlockMap::iterator miPrev = mapBlockIndex.find(block.hashPrevBlock);
if (miPrev != mapBlockIndex.end())
{
pindexNew->pprev = (*miPrev).second;
pindexNew->nHeight = pindexNew->pprev->nHeight + 1;
pindexNew->BuildSkip();
}
pindexNew->nTimeMax = (pindexNew->pprev ? std::max(pindexNew->pprev->nTimeMax, pindexNew->nTime) : pindexNew->nTime);
pindexNew->nChainWork = (pindexNew->pprev ? pindexNew->pprev->nChainWork : 0) + GetBlockProof(*pindexNew);
pindexNew->RaiseValidity(BLOCK_VALID_TREE);
if (pindexBestHeader == NULL || pindexBestHeader->nChainWork < pindexNew->nChainWork)
pindexBestHeader = pindexNew;
setDirtyBlockIndex.insert(pindexNew);
return pindexNew;
}
/** Mark a block as having its data received and checked (up to BLOCK_VALID_TRANSACTIONS). */
bool ReceivedBlockTransactions(const CBlock &block, CValidationState& state, CBlockIndex *pindexNew, const CDiskBlockPos& pos)
{
pindexNew->nTx = block.vtx.size();
pindexNew->nChainTx = 0;
pindexNew->nFile = pos.nFile;
pindexNew->nDataPos = pos.nPos;
pindexNew->nUndoPos = 0;
pindexNew->nStatus |= BLOCK_HAVE_DATA;
if (IsWitnessEnabled(pindexNew->pprev, Params().GetConsensus())) {
pindexNew->nStatus |= BLOCK_OPT_WITNESS;
}
pindexNew->RaiseValidity(BLOCK_VALID_TRANSACTIONS);
setDirtyBlockIndex.insert(pindexNew);
if (pindexNew->pprev == NULL || pindexNew->pprev->nChainTx) {
// If pindexNew is the genesis block or all parents are BLOCK_VALID_TRANSACTIONS.
std::deque<CBlockIndex*> queue;
queue.push_back(pindexNew);
// Recursively process any descendant blocks that now may be eligible to be connected.
while (!queue.empty()) {
CBlockIndex *pindex = queue.front();
queue.pop_front();
pindex->nChainTx = (pindex->pprev ? pindex->pprev->nChainTx : 0) + pindex->nTx;
{
LOCK(cs_nBlockSequenceId);
pindex->nSequenceId = nBlockSequenceId++;
}
if (chainActive.Tip() == NULL || !setBlockIndexCandidates.value_comp()(pindex, chainActive.Tip())) {
setBlockIndexCandidates.insert(pindex);
}
std::pair<std::multimap<CBlockIndex*, CBlockIndex*>::iterator, std::multimap<CBlockIndex*, CBlockIndex*>::iterator> range = mapBlocksUnlinked.equal_range(pindex);
while (range.first != range.second) {
std::multimap<CBlockIndex*, CBlockIndex*>::iterator it = range.first;
queue.push_back(it->second);
range.first++;
mapBlocksUnlinked.erase(it);
}
}
} else {
if (pindexNew->pprev && pindexNew->pprev->IsValid(BLOCK_VALID_TREE)) {
mapBlocksUnlinked.insert(std::make_pair(pindexNew->pprev, pindexNew));
}
}
return true;
}
bool FindBlockPos(CValidationState &state, CDiskBlockPos &pos, unsigned int nAddSize, unsigned int nHeight, uint64_t nTime, bool fKnown = false)
{
LOCK(cs_LastBlockFile);
unsigned int nFile = fKnown ? pos.nFile : nLastBlockFile;
if (vinfoBlockFile.size() <= nFile) {
vinfoBlockFile.resize(nFile + 1);
}
if (!fKnown) {
while (vinfoBlockFile[nFile].nSize + nAddSize >= MAX_BLOCKFILE_SIZE) {
nFile++;
if (vinfoBlockFile.size() <= nFile) {
vinfoBlockFile.resize(nFile + 1);
}
}
pos.nFile = nFile;
pos.nPos = vinfoBlockFile[nFile].nSize;
}
if ((int)nFile != nLastBlockFile) {
if (!fKnown) {
LogPrintf("Leaving block file %i: %s\n", nLastBlockFile, vinfoBlockFile[nLastBlockFile].ToString());
}
FlushBlockFile(!fKnown);
nLastBlockFile = nFile;
}
vinfoBlockFile[nFile].AddBlock(nHeight, nTime);
if (fKnown)
vinfoBlockFile[nFile].nSize = std::max(pos.nPos + nAddSize, vinfoBlockFile[nFile].nSize);
else
vinfoBlockFile[nFile].nSize += nAddSize;
if (!fKnown) {
unsigned int nOldChunks = (pos.nPos + BLOCKFILE_CHUNK_SIZE - 1) / BLOCKFILE_CHUNK_SIZE;
unsigned int nNewChunks = (vinfoBlockFile[nFile].nSize + BLOCKFILE_CHUNK_SIZE - 1) / BLOCKFILE_CHUNK_SIZE;
if (nNewChunks > nOldChunks) {
if (fPruneMode)
fCheckForPruning = true;
if (CheckDiskSpace(nNewChunks * BLOCKFILE_CHUNK_SIZE - pos.nPos)) {
FILE *file = OpenBlockFile(pos);
if (file) {
LogPrintf("Pre-allocating up to position 0x%x in blk%05u.dat\n", nNewChunks * BLOCKFILE_CHUNK_SIZE, pos.nFile);
AllocateFileRange(file, pos.nPos, nNewChunks * BLOCKFILE_CHUNK_SIZE - pos.nPos);
fclose(file);
}
}
else
return state.Error("out of disk space");
}
}
setDirtyFileInfo.insert(nFile);
return true;
}
bool FindUndoPos(CValidationState &state, int nFile, CDiskBlockPos &pos, unsigned int nAddSize)
{
pos.nFile = nFile;
LOCK(cs_LastBlockFile);
unsigned int nNewSize;
pos.nPos = vinfoBlockFile[nFile].nUndoSize;
nNewSize = vinfoBlockFile[nFile].nUndoSize += nAddSize;
setDirtyFileInfo.insert(nFile);
unsigned int nOldChunks = (pos.nPos + UNDOFILE_CHUNK_SIZE - 1) / UNDOFILE_CHUNK_SIZE;
unsigned int nNewChunks = (nNewSize + UNDOFILE_CHUNK_SIZE - 1) / UNDOFILE_CHUNK_SIZE;
if (nNewChunks > nOldChunks) {
if (fPruneMode)
fCheckForPruning = true;
if (CheckDiskSpace(nNewChunks * UNDOFILE_CHUNK_SIZE - pos.nPos)) {
FILE *file = OpenUndoFile(pos);
if (file) {
LogPrintf("Pre-allocating up to position 0x%x in rev%05u.dat\n", nNewChunks * UNDOFILE_CHUNK_SIZE, pos.nFile);
AllocateFileRange(file, pos.nPos, nNewChunks * UNDOFILE_CHUNK_SIZE - pos.nPos);
fclose(file);
}
}
else
return state.Error("out of disk space");
}
return true;
}
bool CheckBlockHeader(const CBlockHeader& block, CValidationState& state, const Consensus::Params& consensusParams, bool fCheckPOW)
{
// Check proof of work matches claimed amount
if (fCheckPOW && !CheckProofOfWork(block.GetPoWHash(), block.nBits, consensusParams))
return state.DoS(50, false, REJECT_INVALID, "high-hash", false, "proof of work failed");
return true;
}
bool CheckBlock(const CBlock& block, CValidationState& state, const Consensus::Params& consensusParams, bool fCheckPOW, bool fCheckMerkleRoot)
{
// These are checks that are independent of context.
if (block.fChecked)
return true;
// Check that the header is valid (particularly PoW). This is mostly
// redundant with the call in AcceptBlockHeader.
if (!CheckBlockHeader(block, state, consensusParams, fCheckPOW))
return false;
// Check the merkle root.
if (fCheckMerkleRoot) {
bool mutated;
uint256 hashMerkleRoot2 = BlockMerkleRoot(block, &mutated);
if (block.hashMerkleRoot != hashMerkleRoot2)
return state.DoS(100, false, REJECT_INVALID, "bad-txnmrklroot", true, "hashMerkleRoot mismatch");
// Check for merkle tree malleability (CVE-2012-2459): repeating sequences
// of transactions in a block without affecting the merkle root of a block,
// while still invalidating it.
if (mutated)
return state.DoS(100, false, REJECT_INVALID, "bad-txns-duplicate", true, "duplicate transaction");
}
// All potential-corruption validation must be done before we do any
// transaction validation, as otherwise we may mark the header as invalid
// because we receive the wrong transactions for it.
// Note that witness malleability is checked in ContextualCheckBlock, so no
// checks that use witness data may be performed here.
// Size limits
if (block.vtx.empty() || block.vtx.size() > MAX_BLOCK_BASE_SIZE || ::GetSerializeSize(block, SER_NETWORK, PROTOCOL_VERSION | SERIALIZE_TRANSACTION_NO_WITNESS) > MAX_BLOCK_BASE_SIZE)
return state.DoS(100, false, REJECT_INVALID, "bad-blk-length", false, "size limits failed");
// First transaction must be coinbase, the rest must not be
if (block.vtx.empty() || !block.vtx[0]->IsCoinBase())
return state.DoS(100, false, REJECT_INVALID, "bad-cb-missing", false, "first tx is not coinbase");
for (unsigned int i = 1; i < block.vtx.size(); i++)
if (block.vtx[i]->IsCoinBase())
return state.DoS(100, false, REJECT_INVALID, "bad-cb-multiple", false, "more than one coinbase");
// Check transactions
for (const auto& tx : block.vtx)
if (!CheckTransaction(*tx, state, false))
return state.Invalid(false, state.GetRejectCode(), state.GetRejectReason(),
strprintf("Transaction check failed (tx hash %s) %s", tx->GetHash().ToString(), state.GetDebugMessage()));
unsigned int nSigOps = 0;
for (const auto& tx : block.vtx)
{
nSigOps += GetLegacySigOpCount(*tx);
}
if (nSigOps * WITNESS_SCALE_FACTOR > MAX_BLOCK_SIGOPS_COST)
return state.DoS(100, false, REJECT_INVALID, "bad-blk-sigops", false, "out-of-bounds SigOpCount");
if (fCheckPOW && fCheckMerkleRoot)
block.fChecked = true;
return true;
}
static bool CheckIndexAgainstCheckpoint(const CBlockIndex* pindexPrev, CValidationState& state, const CChainParams& chainparams, const uint256& hash)
{
if (*pindexPrev->phashBlock == chainparams.GetConsensus().hashGenesisBlock)
return true;
int nHeight = pindexPrev->nHeight+1;
// Don't accept any forks from the main chain prior to last checkpoint
CBlockIndex* pcheckpoint = Checkpoints::GetLastCheckpoint(chainparams.Checkpoints());
if (pcheckpoint && nHeight < pcheckpoint->nHeight)
return state.DoS(100, error("%s: forked chain older than last checkpoint (height %d)", __func__, nHeight));
return true;
}
bool IsWitnessEnabled(const CBlockIndex* pindexPrev, const Consensus::Params& params)
{
LOCK(cs_main);
return (VersionBitsState(pindexPrev, params, Consensus::DEPLOYMENT_SEGWIT, versionbitscache) == THRESHOLD_ACTIVE);
}
// Compute at which vout of the block's coinbase transaction the witness
// commitment occurs, or -1 if not found.
static int GetWitnessCommitmentIndex(const CBlock& block)
{
int commitpos = -1;
if (!block.vtx.empty()) {
for (size_t o = 0; o < block.vtx[0]->vout.size(); o++) {
if (block.vtx[0]->vout[o].scriptPubKey.size() >= 38 && block.vtx[0]->vout[o].scriptPubKey[0] == OP_RETURN && block.vtx[0]->vout[o].scriptPubKey[1] == 0x24 && block.vtx[0]->vout[o].scriptPubKey[2] == 0xaa && block.vtx[0]->vout[o].scriptPubKey[3] == 0x21 && block.vtx[0]->vout[o].scriptPubKey[4] == 0xa9 && block.vtx[0]->vout[o].scriptPubKey[5] == 0xed) {
commitpos = o;
}
}
}
return commitpos;
}
void UpdateUncommittedBlockStructures(CBlock& block, const CBlockIndex* pindexPrev, const Consensus::Params& consensusParams)
{
int commitpos = GetWitnessCommitmentIndex(block);
static const std::vector<unsigned char> nonce(32, 0x00);
if (commitpos != -1 && IsWitnessEnabled(pindexPrev, consensusParams) && !block.vtx[0]->HasWitness()) {
CMutableTransaction tx(*block.vtx[0]);
tx.vin[0].scriptWitness.stack.resize(1);
tx.vin[0].scriptWitness.stack[0] = nonce;
block.vtx[0] = MakeTransactionRef(std::move(tx));
}
}
std::vector<unsigned char> GenerateCoinbaseCommitment(CBlock& block, const CBlockIndex* pindexPrev, const Consensus::Params& consensusParams)
{
std::vector<unsigned char> commitment;
int commitpos = GetWitnessCommitmentIndex(block);
std::vector<unsigned char> ret(32, 0x00);
if (consensusParams.vDeployments[Consensus::DEPLOYMENT_SEGWIT].nTimeout != 0) {
if (commitpos == -1) {
uint256 witnessroot = BlockWitnessMerkleRoot(block, NULL);
CHash256().Write(witnessroot.begin(), 32).Write(&ret[0], 32).Finalize(witnessroot.begin());
CTxOut out;
out.nValue = 0;
out.scriptPubKey.resize(38);
out.scriptPubKey[0] = OP_RETURN;
out.scriptPubKey[1] = 0x24;
out.scriptPubKey[2] = 0xaa;
out.scriptPubKey[3] = 0x21;
out.scriptPubKey[4] = 0xa9;
out.scriptPubKey[5] = 0xed;
memcpy(&out.scriptPubKey[6], witnessroot.begin(), 32);
commitment = std::vector<unsigned char>(out.scriptPubKey.begin(), out.scriptPubKey.end());
CMutableTransaction tx(*block.vtx[0]);
tx.vout.push_back(out);
block.vtx[0] = MakeTransactionRef(std::move(tx));
}
}
UpdateUncommittedBlockStructures(block, pindexPrev, consensusParams);
return commitment;
}
bool ContextualCheckBlockHeader(const CBlockHeader& block, CValidationState& state, const Consensus::Params& consensusParams, const CBlockIndex* pindexPrev, int64_t nAdjustedTime)
{
const int nHeight = pindexPrev == NULL ? 0 : pindexPrev->nHeight + 1;
// Check proof of work
if (block.nBits != GetNextWorkRequired(pindexPrev, &block, consensusParams))
return state.DoS(100, false, REJECT_INVALID, "bad-diffbits", false, "incorrect proof of work");
// Check timestamp against prev
if (block.GetBlockTime() <= pindexPrev->GetMedianTimePast())
return state.Invalid(false, REJECT_INVALID, "time-too-old", "block's timestamp is too early");
// Check timestamp
if (block.GetBlockTime() > nAdjustedTime + 2 * 60 * 60)
return state.Invalid(false, REJECT_INVALID, "time-too-new", "block timestamp too far in the future");
// Reject outdated version blocks when 95% (75% on testnet) of the network has upgraded:
// check for version 2, 3 and 4 upgrades
if((block.nVersion < 2 && nHeight >= consensusParams.BIP34Height) ||
(block.nVersion < 3 && nHeight >= consensusParams.BIP66Height) ||
(block.nVersion < 4 && nHeight >= consensusParams.BIP65Height))
return state.Invalid(false, REJECT_OBSOLETE, strprintf("bad-version(0x%08x)", block.nVersion),
strprintf("rejected nVersion=0x%08x block", block.nVersion));
if (block.nVersion < VERSIONBITS_TOP_BITS && IsWitnessEnabled(pindexPrev, consensusParams))
return state.Invalid(false, REJECT_OBSOLETE, strprintf("bad-version(0x%08x)", block.nVersion),
strprintf("rejected nVersion=0x%08x block", block.nVersion));
return true;
}
bool ContextualCheckBlock(const CBlock& block, CValidationState& state, const Consensus::Params& consensusParams, const CBlockIndex* pindexPrev)
{
const int nHeight = pindexPrev == NULL ? 0 : pindexPrev->nHeight + 1;
// Start enforcing BIP113 (Median Time Past) using versionbits logic.
int nLockTimeFlags = 0;
if (VersionBitsState(pindexPrev, consensusParams, Consensus::DEPLOYMENT_CSV, versionbitscache) == THRESHOLD_ACTIVE) {
nLockTimeFlags |= LOCKTIME_MEDIAN_TIME_PAST;
}
int64_t nLockTimeCutoff = (nLockTimeFlags & LOCKTIME_MEDIAN_TIME_PAST)
? pindexPrev->GetMedianTimePast()
: block.GetBlockTime();
// Check that all transactions are finalized
for (const auto& tx : block.vtx) {
if (!IsFinalTx(*tx, nHeight, nLockTimeCutoff)) {
return state.DoS(10, false, REJECT_INVALID, "bad-txns-nonfinal", false, "non-final transaction");
}
}
// Enforce rule that the coinbase starts with serialized block height
if (nHeight >= consensusParams.BIP34Height)
{
CScript expect = CScript() << nHeight;
if (block.vtx[0]->vin[0].scriptSig.size() < expect.size() ||
!std::equal(expect.begin(), expect.end(), block.vtx[0]->vin[0].scriptSig.begin())) {
return state.DoS(100, false, REJECT_INVALID, "bad-cb-height", false, "block height mismatch in coinbase");
}
}
// Validation for witness commitments.
// * We compute the witness hash (which is the hash including witnesses) of all the block's transactions, except the
// coinbase (where 0x0000....0000 is used instead).
// * The coinbase scriptWitness is a stack of a single 32-byte vector, containing a witness nonce (unconstrained).
// * We build a merkle tree with all those witness hashes as leaves (similar to the hashMerkleRoot in the block header).
// * There must be at least one output whose scriptPubKey is a single 36-byte push, the first 4 bytes of which are
// {0xaa, 0x21, 0xa9, 0xed}, and the following 32 bytes are SHA256^2(witness root, witness nonce). In case there are
// multiple, the last one is used.
bool fHaveWitness = false;
if (VersionBitsState(pindexPrev, consensusParams, Consensus::DEPLOYMENT_SEGWIT, versionbitscache) == THRESHOLD_ACTIVE) {
int commitpos = GetWitnessCommitmentIndex(block);
if (commitpos != -1) {
bool malleated = false;
uint256 hashWitness = BlockWitnessMerkleRoot(block, &malleated);
// The malleation check is ignored; as the transaction tree itself
// already does not permit it, it is impossible to trigger in the
// witness tree.
if (block.vtx[0]->vin[0].scriptWitness.stack.size() != 1 || block.vtx[0]->vin[0].scriptWitness.stack[0].size() != 32) {
return state.DoS(100, false, REJECT_INVALID, "bad-witness-nonce-size", true, strprintf("%s : invalid witness nonce size", __func__));
}
CHash256().Write(hashWitness.begin(), 32).Write(&block.vtx[0]->vin[0].scriptWitness.stack[0][0], 32).Finalize(hashWitness.begin());
if (memcmp(hashWitness.begin(), &block.vtx[0]->vout[commitpos].scriptPubKey[6], 32)) {
return state.DoS(100, false, REJECT_INVALID, "bad-witness-merkle-match", true, strprintf("%s : witness merkle commitment mismatch", __func__));
}
fHaveWitness = true;
}
}
// No witness data is allowed in blocks that don't commit to witness data, as this would otherwise leave room for spam
if (!fHaveWitness) {
for (size_t i = 0; i < block.vtx.size(); i++) {
if (block.vtx[i]->HasWitness()) {
return state.DoS(100, false, REJECT_INVALID, "unexpected-witness", true, strprintf("%s : unexpected witness data found", __func__));
}
}
}
// After the coinbase witness nonce and commitment are verified,
// we can check if the block weight passes (before we've checked the
// coinbase witness, it would be possible for the weight to be too
// large by filling up the coinbase witness, which doesn't change
// the block hash, so we couldn't mark the block as permanently
// failed).
if (GetBlockWeight(block) > MAX_BLOCK_WEIGHT) {
return state.DoS(100, false, REJECT_INVALID, "bad-blk-weight", false, strprintf("%s : weight limit failed", __func__));
}
return true;
}
static bool AcceptBlockHeader(const CBlockHeader& block, CValidationState& state, const CChainParams& chainparams, CBlockIndex** ppindex)
{
AssertLockHeld(cs_main);
// Check for duplicate
uint256 hash = block.GetHash();
BlockMap::iterator miSelf = mapBlockIndex.find(hash);
CBlockIndex *pindex = NULL;
if (hash != chainparams.GetConsensus().hashGenesisBlock) {
if (miSelf != mapBlockIndex.end()) {
// Block header is already known.
pindex = miSelf->second;
if (ppindex)
*ppindex = pindex;
if (pindex->nStatus & BLOCK_FAILED_MASK)
return state.Invalid(error("%s: block %s is marked invalid", __func__, hash.ToString()), 0, "duplicate");
return true;
}
if (!CheckBlockHeader(block, state, chainparams.GetConsensus()))
return error("%s: Consensus::CheckBlockHeader: %s, %s", __func__, hash.ToString(), FormatStateMessage(state));
// Get prev block index
CBlockIndex* pindexPrev = NULL;
BlockMap::iterator mi = mapBlockIndex.find(block.hashPrevBlock);
if (mi == mapBlockIndex.end())
return state.DoS(10, error("%s: prev block not found", __func__), 0, "bad-prevblk");
pindexPrev = (*mi).second;
if (pindexPrev->nStatus & BLOCK_FAILED_MASK)
return state.DoS(100, error("%s: prev block invalid", __func__), REJECT_INVALID, "bad-prevblk");
assert(pindexPrev);
if (fCheckpointsEnabled && !CheckIndexAgainstCheckpoint(pindexPrev, state, chainparams, hash))
return error("%s: CheckIndexAgainstCheckpoint(): %s", __func__, state.GetRejectReason().c_str());
if (!ContextualCheckBlockHeader(block, state, chainparams.GetConsensus(), pindexPrev, GetAdjustedTime()))
return error("%s: Consensus::ContextualCheckBlockHeader: %s, %s", __func__, hash.ToString(), FormatStateMessage(state));
}
if (pindex == NULL)
pindex = AddToBlockIndex(block);
if (ppindex)
*ppindex = pindex;
CheckBlockIndex(chainparams.GetConsensus());
return true;
}
// Exposed wrapper for AcceptBlockHeader
bool ProcessNewBlockHeaders(const std::vector<CBlockHeader>& headers, CValidationState& state, const CChainParams& chainparams, const CBlockIndex** ppindex)
{
{
LOCK(cs_main);
for (const CBlockHeader& header : headers) {
CBlockIndex *pindex = NULL; // Use a temp pindex instead of ppindex to avoid a const_cast
if (!AcceptBlockHeader(header, state, chainparams, &pindex)) {
return false;
}
if (ppindex) {
*ppindex = pindex;
}
}
}
NotifyHeaderTip();
return true;
}
/** Store block on disk. If dbp is non-NULL, the file is known to already reside on disk */
static bool AcceptBlock(const std::shared_ptr<const CBlock>& pblock, CValidationState& state, const CChainParams& chainparams, CBlockIndex** ppindex, bool fRequested, const CDiskBlockPos* dbp, bool* fNewBlock)
{