github
/
bitcoin
mirror of https://github.com/bitcoin/bitcoin
1
Fork 0
Code Releases Activity
bitcoin/src/validation.cpp

5363 lines
252 KiB
C++
Raw Blame History

// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2022 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 <kernel/coinstats.h>
#include <kernel/mempool_persist.h>
#include <arith_uint256.h>
#include <chain.h>
#include <chainparams.h>
#include <checkqueue.h>
#include <consensus/amount.h>
#include <consensus/consensus.h>
#include <consensus/merkle.h>
#include <consensus/tx_check.h>
#include <consensus/tx_verify.h>
#include <consensus/validation.h>
#include <cuckoocache.h>
#include <flatfile.h>
#include <fs.h>
#include <hash.h>
#include <kernel/mempool_entry.h>
#include <logging.h>
#include <logging/timer.h>
#include <node/blockstorage.h>
#include <node/interface_ui.h>
#include <node/utxo_snapshot.h>
#include <policy/policy.h>
#include <policy/rbf.h>
#include <policy/settings.h>
#include <pow.h>
#include <primitives/block.h>
#include <primitives/transaction.h>
#include <random.h>
#include <reverse_iterator.h>
#include <script/script.h>
#include <script/sigcache.h>
#include <shutdown.h>
#include <signet.h>
#include <tinyformat.h>
#include <txdb.h>
#include <txmempool.h>
#include <uint256.h>
#include <undo.h>
#include <util/check.h> // For NDEBUG compile time check
#include <util/hasher.h>
#include <util/moneystr.h>
#include <util/rbf.h>
#include <util/strencodings.h>
#include <util/system.h>
#include <util/time.h>
#include <util/trace.h>
#include <util/translation.h>
#include <validationinterface.h>
#include <warnings.h>
#include <algorithm>
#include <cassert>
#include <chrono>
#include <deque>
#include <numeric>
#include <optional>
#include <string>
#include <utility>
using kernel::CCoinsStats;
using kernel::CoinStatsHashType;
using kernel::ComputeUTXOStats;
using kernel::LoadMempool;
using fsbridge::FopenFn;
using node::BlockManager;
using node::BlockMap;
using node::CBlockIndexHeightOnlyComparator;
using node::CBlockIndexWorkComparator;
using node::fImporting;
using node::fPruneMode;
using node::fReindex;
using node::ReadBlockFromDisk;
using node::SnapshotMetadata;
using node::UndoReadFromDisk;
using node::UnlinkPrunedFiles;
/** Maximum kilobytes for transactions to store for processing during reorg */
static const unsigned int MAX_DISCONNECTED_TX_POOL_SIZE = 20000;
/** Time to wait between writing blocks/block index to disk. */
static constexpr std::chrono::hours DATABASE_WRITE_INTERVAL{1};
/** Time to wait between flushing chainstate to disk. */
static constexpr std::chrono::hours DATABASE_FLUSH_INTERVAL{24};
/** Maximum age of our tip for us to be considered current for fee estimation */
static constexpr std::chrono::hours MAX_FEE_ESTIMATION_TIP_AGE{3};
const std::vector<std::string> CHECKLEVEL_DOC {
"level 0 reads the blocks from disk",
"level 1 verifies block validity",
"level 2 verifies undo data",
"level 3 checks disconnection of tip blocks",
"level 4 tries to reconnect the blocks",
"each level includes the checks of the previous levels",
};
/** The number of blocks to keep below the deepest prune lock.
* There is nothing special about this number. It is higher than what we
* expect to see in regular mainnet reorgs, but not so high that it would
* noticeably interfere with the pruning mechanism.
* */
static constexpr int PRUNE_LOCK_BUFFER{10};
GlobalMutex g_best_block_mutex;
std::condition_variable g_best_block_cv;
uint256 g_best_block;
const CBlockIndex* Chainstate::FindForkInGlobalIndex(const CBlockLocator& locator) const
{
AssertLockHeld(cs_main);
// Find the latest block common to locator and chain - we expect that
// locator.vHave is sorted descending by height.
for (const uint256& hash : locator.vHave) {
const CBlockIndex* pindex{m_blockman.LookupBlockIndex(hash)};
if (pindex) {
if (m_chain.Contains(pindex)) {
return pindex;
}
if (pindex->GetAncestor(m_chain.Height()) == m_chain.Tip()) {
return m_chain.Tip();
}
}
}
return m_chain.Genesis();
}
bool CheckInputScripts(const CTransaction& tx, TxValidationState& state,
const CCoinsViewCache& inputs, unsigned int flags, bool cacheSigStore,
bool cacheFullScriptStore, PrecomputedTransactionData& txdata,
std::vector<CScriptCheck>* pvChecks = nullptr)
EXCLUSIVE_LOCKS_REQUIRED(cs_main);
bool CheckFinalTxAtTip(const CBlockIndex& active_chain_tip, const CTransaction& tx)
{
AssertLockHeld(cs_main);
// CheckFinalTxAtTip() uses active_chain_tip.Height()+1 to evaluate
// nLockTime because when IsFinalTx() is called within
// 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 active_chain_tip.Height().
const int nBlockHeight = active_chain_tip.nHeight + 1;
// BIP113 requires 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().
const int64_t nBlockTime{active_chain_tip.GetMedianTimePast()};
return IsFinalTx(tx, nBlockHeight, nBlockTime);
}
bool CheckSequenceLocksAtTip(CBlockIndex* tip,
const CCoinsView& coins_view,
const CTransaction& tx,
LockPoints* lp,
bool useExistingLockPoints)
{
assert(tip != nullptr);
CBlockIndex index;
index.pprev = tip;
// CheckSequenceLocksAtTip() uses active_chainstate.m_chain.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 active_chainstate.m_chain.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 {
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];
Coin coin;
if (!coins_view.GetCoin(txin.prevout, coin)) {
return error("%s: Missing input", __func__);
}
if (coin.nHeight == MEMPOOL_HEIGHT) {
// Assume all mempool transaction confirm in the next block
prevheights[txinIndex] = tip->nHeight + 1;
} else {
prevheights[txinIndex] = coin.nHeight;
}
}
lockPair = CalculateSequenceLocks(tx, STANDARD_LOCKTIME_VERIFY_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
// CheckSequenceLocksAtTip to indicate the LockPoints validity
int maxInputHeight = 0;
for (const 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);
}
}
// tip->GetAncestor(maxInputHeight) should never return a nullptr
// because maxInputHeight is always less than the tip height.
// It would, however, be a bad bug to continue execution, since a
// LockPoints object with the maxInputBlock member set to nullptr
// signifies no relative lock time.
lp->maxInputBlock = Assert(tip->GetAncestor(maxInputHeight));
}
}
return EvaluateSequenceLocks(index, lockPair);
}
// Returns the script flags which should be checked for a given block
static unsigned int GetBlockScriptFlags(const CBlockIndex& block_index, const ChainstateManager& chainman);
static void LimitMempoolSize(CTxMemPool& pool, CCoinsViewCache& coins_cache)
EXCLUSIVE_LOCKS_REQUIRED(::cs_main, pool.cs)
{
AssertLockHeld(::cs_main);
AssertLockHeld(pool.cs);
int expired = pool.Expire(GetTime<std::chrono::seconds>() - pool.m_expiry);
if (expired != 0) {
LogPrint(BCLog::MEMPOOL, "Expired %i transactions from the memory pool\n", expired);
}
std::vector<COutPoint> vNoSpendsRemaining;
pool.TrimToSize(pool.m_max_size_bytes, &vNoSpendsRemaining);
for (const COutPoint& removed : vNoSpendsRemaining)
coins_cache.Uncache(removed);
}
static bool IsCurrentForFeeEstimation(Chainstate& active_chainstate) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
{
AssertLockHeld(cs_main);
if (active_chainstate.IsInitialBlockDownload())
return false;
if (active_chainstate.m_chain.Tip()->GetBlockTime() < count_seconds(GetTime<std::chrono::seconds>() - MAX_FEE_ESTIMATION_TIP_AGE))
return false;
if (active_chainstate.m_chain.Height() < active_chainstate.m_chainman.m_best_header->nHeight - 1) {
return false;
}
return true;
}
void Chainstate::MaybeUpdateMempoolForReorg(
DisconnectedBlockTransactions& disconnectpool,
bool fAddToMempool)
{
if (!m_mempool) return;
AssertLockHeld(cs_main);
AssertLockHeld(m_mempool->cs);
std::vector<uint256> vHashUpdate;
// disconnectpool's insertion_order index sorts the entries from
// oldest to newest, but the oldest entry will be the last tx from the
// latest mined block that was disconnected.
// Iterate disconnectpool in reverse, so that we add transactions
// back to the mempool starting with the earliest transaction that had
// been previously seen in a block.
auto it = disconnectpool.queuedTx.get<insertion_order>().rbegin();
while (it != disconnectpool.queuedTx.get<insertion_order>().rend()) {
// ignore validation errors in resurrected transactions
if (!fAddToMempool || (*it)->IsCoinBase() ||
AcceptToMemoryPool(*this, *it, GetTime(),
/*bypass_limits=*/true, /*test_accept=*/false).m_result_type !=
MempoolAcceptResult::ResultType::VALID) {
// If the transaction doesn't make it in to the mempool, remove any
// transactions that depend on it (which would now be orphans).
m_mempool->removeRecursive(**it, MemPoolRemovalReason::REORG);
} else if (m_mempool->exists(GenTxid::Txid((*it)->GetHash()))) {
vHashUpdate.push_back((*it)->GetHash());
}
++it;
}
disconnectpool.queuedTx.clear();
// 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
// the disconnectpool that were added back and cleans up the mempool state.
m_mempool->UpdateTransactionsFromBlock(vHashUpdate);
// Predicate to use for filtering transactions in removeForReorg.
// Checks whether the transaction is still final and, if it spends a coinbase output, mature.
// Also updates valid entries' cached LockPoints if needed.
// If false, the tx is still valid and its lockpoints are updated.
// If true, the tx would be invalid in the next block; remove this entry and all of its descendants.
const auto filter_final_and_mature = [this](CTxMemPool::txiter it)
EXCLUSIVE_LOCKS_REQUIRED(m_mempool->cs, ::cs_main) {
AssertLockHeld(m_mempool->cs);
AssertLockHeld(::cs_main);
const CTransaction& tx = it->GetTx();
// The transaction must be final.
if (!CheckFinalTxAtTip(*Assert(m_chain.Tip()), tx)) return true;
LockPoints lp = it->GetLockPoints();
const bool validLP{TestLockPointValidity(m_chain, lp)};
CCoinsViewMemPool view_mempool(&CoinsTip(), *m_mempool);
// CheckSequenceLocksAtTip checks if the transaction will be final in the next block to be
// created on top of the new chain. We use useExistingLockPoints=false so that, instead of
// using the information in lp (which might now refer to a block that no longer exists in
// the chain), it will update lp to contain LockPoints relevant to the new chain.
if (!CheckSequenceLocksAtTip(m_chain.Tip(), view_mempool, tx, &lp, validLP)) {
// If CheckSequenceLocksAtTip fails, remove the tx and don't depend on the LockPoints.
return true;
} else if (!validLP) {
// If CheckSequenceLocksAtTip succeeded, it also updated the LockPoints.
// Now update the mempool entry lockpoints as well.
m_mempool->mapTx.modify(it, [&lp](CTxMemPoolEntry& e) { e.UpdateLockPoints(lp); });
}
// If the transaction spends any coinbase outputs, it must be mature.
if (it->GetSpendsCoinbase()) {
for (const CTxIn& txin : tx.vin) {
auto it2 = m_mempool->mapTx.find(txin.prevout.hash);
if (it2 != m_mempool->mapTx.end())
continue;
const Coin& coin{CoinsTip().AccessCoin(txin.prevout)};
assert(!coin.IsSpent());
const auto mempool_spend_height{m_chain.Tip()->nHeight + 1};
if (coin.IsCoinBase() && mempool_spend_height - coin.nHeight < COINBASE_MATURITY) {
return true;
}
}
}
// Transaction is still valid and cached LockPoints are updated.
return false;
};
// We also need to remove any now-immature transactions
m_mempool->removeForReorg(m_chain, filter_final_and_mature);
// Re-limit mempool size, in case we added any transactions
LimitMempoolSize(*m_mempool, this->CoinsTip());
}
/**
* Checks to avoid mempool polluting consensus critical paths since cached
* signature and script validity results will be reused if we validate this
* transaction again during block validation.
* */
static bool CheckInputsFromMempoolAndCache(const CTransaction& tx, TxValidationState& state,
const CCoinsViewCache& view, const CTxMemPool& pool,
unsigned int flags, PrecomputedTransactionData& txdata, CCoinsViewCache& coins_tip)
EXCLUSIVE_LOCKS_REQUIRED(cs_main, pool.cs)
{
AssertLockHeld(cs_main);
AssertLockHeld(pool.cs);
assert(!tx.IsCoinBase());
for (const CTxIn& txin : tx.vin) {
const Coin& coin = view.AccessCoin(txin.prevout);
// This coin was checked in PreChecks and MemPoolAccept
// has been holding cs_main since then.
Assume(!coin.IsSpent());
if (coin.IsSpent()) return false;
// If the Coin is available, there are 2 possibilities:
// it is available in our current ChainstateActive UTXO set,
// or it's a UTXO provided by a transaction in our mempool.
// Ensure the scriptPubKeys in Coins from CoinsView are correct.
const CTransactionRef& txFrom = pool.get(txin.prevout.hash);
if (txFrom) {
assert(txFrom->GetHash() == txin.prevout.hash);
assert(txFrom->vout.size() > txin.prevout.n);
assert(txFrom->vout[txin.prevout.n] == coin.out);
} else {
const Coin& coinFromUTXOSet = coins_tip.AccessCoin(txin.prevout);
assert(!coinFromUTXOSet.IsSpent());
assert(coinFromUTXOSet.out == coin.out);
}
}
// Call CheckInputScripts() to cache signature and script validity against current tip consensus rules.
return CheckInputScripts(tx, state, view, flags, /* cacheSigStore= */ true, /* cacheFullScriptStore= */ true, txdata);
}
namespace {
class MemPoolAccept
{
public:
explicit MemPoolAccept(CTxMemPool& mempool, Chainstate& active_chainstate) :
m_pool(mempool),
m_view(&m_dummy),
m_viewmempool(&active_chainstate.CoinsTip(), m_pool),
m_active_chainstate(active_chainstate),
m_limits{m_pool.m_limits}
{
}
// We put the arguments we're handed into a struct, so we can pass them
// around easier.
struct ATMPArgs {
const CChainParams& m_chainparams;
const int64_t m_accept_time;
const bool m_bypass_limits;
/*
* Return any outpoints which were not previously present in the coins
* cache, but were added as a result of validating the tx for mempool
* acceptance. This allows the caller to optionally remove the cache
* additions if the associated transaction ends up being rejected by
* the mempool.
*/
std::vector<COutPoint>& m_coins_to_uncache;
const bool m_test_accept;
/** Whether we allow transactions to replace mempool transactions by BIP125 rules. If false,
* any transaction spending the same inputs as a transaction in the mempool is considered
* a conflict. */
const bool m_allow_replacement;
/** When true, the mempool will not be trimmed when individual transactions are submitted in
* Finalize(). Instead, limits should be enforced at the end to ensure the package is not
* partially submitted.
*/
const bool m_package_submission;
/** When true, use package feerates instead of individual transaction feerates for fee-based
* policies such as mempool min fee and min relay fee.
*/
const bool m_package_feerates;
/** Parameters for single transaction mempool validation. */
static ATMPArgs SingleAccept(const CChainParams& chainparams, int64_t accept_time,
bool bypass_limits, std::vector<COutPoint>& coins_to_uncache,
bool test_accept) {
return ATMPArgs{/* m_chainparams */ chainparams,
/* m_accept_time */ accept_time,
/* m_bypass_limits */ bypass_limits,
/* m_coins_to_uncache */ coins_to_uncache,
/* m_test_accept */ test_accept,
/* m_allow_replacement */ true,
/* m_package_submission */ false,
/* m_package_feerates */ false,
};
}
/** Parameters for test package mempool validation through testmempoolaccept. */
static ATMPArgs PackageTestAccept(const CChainParams& chainparams, int64_t accept_time,
std::vector<COutPoint>& coins_to_uncache) {
return ATMPArgs{/* m_chainparams */ chainparams,
/* m_accept_time */ accept_time,
/* m_bypass_limits */ false,
/* m_coins_to_uncache */ coins_to_uncache,
/* m_test_accept */ true,
/* m_allow_replacement */ false,
/* m_package_submission */ false, // not submitting to mempool
/* m_package_feerates */ false,
};
}
/** Parameters for child-with-unconfirmed-parents package validation. */
static ATMPArgs PackageChildWithParents(const CChainParams& chainparams, int64_t accept_time,
std::vector<COutPoint>& coins_to_uncache) {
return ATMPArgs{/* m_chainparams */ chainparams,
/* m_accept_time */ accept_time,
/* m_bypass_limits */ false,
/* m_coins_to_uncache */ coins_to_uncache,
/* m_test_accept */ false,
/* m_allow_replacement */ false,
/* m_package_submission */ true,
/* m_package_feerates */ true,
};
}
/** Parameters for a single transaction within a package. */
static ATMPArgs SingleInPackageAccept(const ATMPArgs& package_args) {
return ATMPArgs{/* m_chainparams */ package_args.m_chainparams,
/* m_accept_time */ package_args.m_accept_time,
/* m_bypass_limits */ false,
/* m_coins_to_uncache */ package_args.m_coins_to_uncache,
/* m_test_accept */ package_args.m_test_accept,
/* m_allow_replacement */ true,
/* m_package_submission */ false,
/* m_package_feerates */ false, // only 1 transaction
};
}
private:
// Private ctor to avoid exposing details to clients and allowing the possibility of
// mixing up the order of the arguments. Use static functions above instead.
ATMPArgs(const CChainParams& chainparams,
int64_t accept_time,
bool bypass_limits,
std::vector<COutPoint>& coins_to_uncache,
bool test_accept,
bool allow_replacement,
bool package_submission,
bool package_feerates)
: m_chainparams{chainparams},
m_accept_time{accept_time},
m_bypass_limits{bypass_limits},
m_coins_to_uncache{coins_to_uncache},
m_test_accept{test_accept},
m_allow_replacement{allow_replacement},
m_package_submission{package_submission},
m_package_feerates{package_feerates}
{
}
};
// Single transaction acceptance
MempoolAcceptResult AcceptSingleTransaction(const CTransactionRef& ptx, ATMPArgs& args) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
/**
* Multiple transaction acceptance. Transactions may or may not be interdependent, but must not
* conflict with each other, and the transactions cannot already be in the mempool. Parents must
* come before children if any dependencies exist.
*/
PackageMempoolAcceptResult AcceptMultipleTransactions(const std::vector<CTransactionRef>& txns, ATMPArgs& args) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
/**
* Package (more specific than just multiple transactions) acceptance. Package must be a child
* with all of its unconfirmed parents, and topologically sorted.
*/
PackageMempoolAcceptResult AcceptPackage(const Package& package, ATMPArgs& args) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
private:
// All the intermediate state that gets passed between the various levels
// of checking a given transaction.
struct Workspace {
explicit Workspace(const CTransactionRef& ptx) : m_ptx(ptx), m_hash(ptx->GetHash()) {}
/** Txids of mempool transactions that this transaction directly conflicts with. */
std::set<uint256> m_conflicts;
/** Iterators to mempool entries that this transaction directly conflicts with. */
CTxMemPool::setEntries m_iters_conflicting;
/** Iterators to all mempool entries that would be replaced by this transaction, including
* those it directly conflicts with and their descendants. */
CTxMemPool::setEntries m_all_conflicting;
/** All mempool ancestors of this transaction. */
CTxMemPool::setEntries m_ancestors;
/** Mempool entry constructed for this transaction. Constructed in PreChecks() but not
* inserted into the mempool until Finalize(). */
std::unique_ptr<CTxMemPoolEntry> m_entry;
/** Pointers to the transactions that have been removed from the mempool and replaced by
* this transaction, used to return to the MemPoolAccept caller. Only populated if
* validation is successful and the original transactions are removed. */
std::list<CTransactionRef> m_replaced_transactions;
/** Virtual size of the transaction as used by the mempool, calculated using serialized size
* of the transaction and sigops. */
int64_t m_vsize;
/** Fees paid by this transaction: total input amounts subtracted by total output amounts. */
CAmount m_base_fees;
/** Base fees + any fee delta set by the user with prioritisetransaction. */
CAmount m_modified_fees;
/** Total modified fees of all transactions being replaced. */
CAmount m_conflicting_fees{0};
/** Total virtual size of all transactions being replaced. */
size_t m_conflicting_size{0};
/** If we're doing package validation (i.e. m_package_feerates=true), the "effective"
* package feerate of this transaction is the total fees divided by the total size of
* transactions (which may include its ancestors and/or descendants). */
CFeeRate m_package_feerate{0};
const CTransactionRef& m_ptx;
/** Txid. */
const uint256& m_hash;
TxValidationState m_state;
/** A temporary cache containing serialized transaction data for signature verification.
* Reused across PolicyScriptChecks and ConsensusScriptChecks. */
PrecomputedTransactionData m_precomputed_txdata;
};
// Run the policy checks on a given transaction, excluding any script checks.
// Looks up inputs, calculates feerate, considers replacement, evaluates
// package limits, etc. As this function can be invoked for "free" by a peer,
// only tests that are fast should be done here (to avoid CPU DoS).
bool PreChecks(ATMPArgs& args, Workspace& ws) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs);
// Run checks for mempool replace-by-fee.
bool ReplacementChecks(Workspace& ws) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs);
// Enforce package mempool ancestor/descendant limits (distinct from individual
// ancestor/descendant limits done in PreChecks).
bool PackageMempoolChecks(const std::vector<CTransactionRef>& txns,
PackageValidationState& package_state) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs);
// Run the script checks using our policy flags. As this can be slow, we should
// only invoke this on transactions that have otherwise passed policy checks.
bool PolicyScriptChecks(const ATMPArgs& args, Workspace& ws) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs);
// Re-run the script checks, using consensus flags, and try to cache the
// result in the scriptcache. This should be done after
// PolicyScriptChecks(). This requires that all inputs either be in our
// utxo set or in the mempool.
bool ConsensusScriptChecks(const ATMPArgs& args, Workspace& ws) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs);
// Try to add the transaction to the mempool, removing any conflicts first.
// Returns true if the transaction is in the mempool after any size
// limiting is performed, false otherwise.
bool Finalize(const ATMPArgs& args, Workspace& ws) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs);
// Submit all transactions to the mempool and call ConsensusScriptChecks to add to the script
// cache - should only be called after successful validation of all transactions in the package.
// The package may end up partially-submitted after size limiting; returns true if all
// transactions are successfully added to the mempool, false otherwise.
bool SubmitPackage(const ATMPArgs& args, std::vector<Workspace>& workspaces, PackageValidationState& package_state,
std::map<const uint256, const MempoolAcceptResult>& results)
EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs);
// Compare a package's feerate against minimum allowed.
bool CheckFeeRate(size_t package_size, CAmount package_fee, TxValidationState& state) EXCLUSIVE_LOCKS_REQUIRED(::cs_main, m_pool.cs)
{
AssertLockHeld(::cs_main);
AssertLockHeld(m_pool.cs);
CAmount mempoolRejectFee = m_pool.GetMinFee().GetFee(package_size);
if (mempoolRejectFee > 0 && package_fee < mempoolRejectFee) {
return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "mempool min fee not met", strprintf("%d < %d", package_fee, mempoolRejectFee));
}
if (package_fee < m_pool.m_min_relay_feerate.GetFee(package_size)) {
return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "min relay fee not met",
strprintf("%d < %d", package_fee, m_pool.m_min_relay_feerate.GetFee(package_size)));
}
return true;
}
private:
CTxMemPool& m_pool;
CCoinsViewCache m_view;
CCoinsViewMemPool m_viewmempool;
CCoinsView m_dummy;
Chainstate& m_active_chainstate;
CTxMemPool::Limits m_limits;
/** Whether the transaction(s) would replace any mempool transactions. If so, RBF rules apply. */
bool m_rbf{false};
};
bool MemPoolAccept::PreChecks(ATMPArgs& args, Workspace& ws)
{
AssertLockHeld(cs_main);
AssertLockHeld(m_pool.cs);
const CTransactionRef& ptx = ws.m_ptx;
const CTransaction& tx = *ws.m_ptx;
const uint256& hash = ws.m_hash;
// Copy/alias what we need out of args
const int64_t nAcceptTime = args.m_accept_time;
const bool bypass_limits = args.m_bypass_limits;
std::vector<COutPoint>& coins_to_uncache = args.m_coins_to_uncache;
// Alias what we need out of ws
TxValidationState& state = ws.m_state;
std::unique_ptr<CTxMemPoolEntry>& entry = ws.m_entry;
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.Invalid(TxValidationResult::TX_CONSENSUS, "coinbase");
// Rather not work on nonstandard transactions (unless -testnet/-regtest)
std::string reason;
if (m_pool.m_require_standard && !IsStandardTx(tx, m_pool.m_max_datacarrier_bytes, m_pool.m_permit_bare_multisig, m_pool.m_dust_relay_feerate, reason)) {
return state.Invalid(TxValidationResult::TX_NOT_STANDARD, reason);
}
// Transactions smaller than 65 non-witness bytes are not relayed to mitigate CVE-2017-12842.
if (::GetSerializeSize(tx, PROTOCOL_VERSION | SERIALIZE_TRANSACTION_NO_WITNESS) < MIN_STANDARD_TX_NONWITNESS_SIZE)
return state.Invalid(TxValidationResult::TX_NOT_STANDARD, "tx-size-small");
// 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 (!CheckFinalTxAtTip(*Assert(m_active_chainstate.m_chain.Tip()), tx)) {
return state.Invalid(TxValidationResult::TX_PREMATURE_SPEND, "non-final");
}
if (m_pool.exists(GenTxid::Wtxid(tx.GetWitnessHash()))) {
// Exact transaction already exists in the mempool.
return state.Invalid(TxValidationResult::TX_CONFLICT, "txn-already-in-mempool");
} else if (m_pool.exists(GenTxid::Txid(tx.GetHash()))) {
// Transaction with the same non-witness data but different witness (same txid, different
// wtxid) already exists in the mempool.
return state.Invalid(TxValidationResult::TX_CONFLICT, "txn-same-nonwitness-data-in-mempool");
}
// Check for conflicts with in-memory transactions
for (const CTxIn &txin : tx.vin)
{
const CTransaction* ptxConflicting = m_pool.GetConflictTx(txin.prevout);
if (ptxConflicting) {
if (!args.m_allow_replacement) {
// Transaction conflicts with a mempool tx, but we're not allowing replacements.
return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "bip125-replacement-disallowed");
}
if (!ws.m_conflicts.count(ptxConflicting->GetHash()))
{
// Transactions that don't explicitly signal replaceability are
// *not* replaceable with the current logic, even if one of their
// unconfirmed ancestors signals replaceability. This diverges
// from BIP125's inherited signaling description (see CVE-2021-31876).
// Applications relying on first-seen mempool behavior should
// check all unconfirmed ancestors; otherwise an opt-in ancestor
// might be replaced, causing removal of this descendant.
//
// If replaceability signaling is ignored due to node setting,
// replacement is always allowed.
if (!m_pool.m_full_rbf && !SignalsOptInRBF(*ptxConflicting)) {
return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "txn-mempool-conflict");
}
ws.m_conflicts.insert(ptxConflicting->GetHash());
}
}
}
LockPoints lp;
m_view.SetBackend(m_viewmempool);
const CCoinsViewCache& coins_cache = m_active_chainstate.CoinsTip();
// do all inputs exist?
for (const CTxIn& txin : tx.vin) {
if (!coins_cache.HaveCoinInCache(txin.prevout)) {
coins_to_uncache.push_back(txin.prevout);
}
// Note: this call may add txin.prevout to the coins cache
// (coins_cache.cacheCoins) by way of FetchCoin(). It should be removed
// later (via coins_to_uncache) if this tx turns out to be invalid.
if (!m_view.HaveCoin(txin.prevout)) {
// Are inputs missing because we already have the tx?
for (size_t out = 0; out < tx.vout.size(); out++) {
// Optimistically just do efficient check of cache for outputs
if (coins_cache.HaveCoinInCache(COutPoint(hash, out))) {
return state.Invalid(TxValidationResult::TX_CONFLICT, "txn-already-known");
}
}
// Otherwise assume this might be an orphan tx for which we just haven't seen parents yet
return state.Invalid(TxValidationResult::TX_MISSING_INPUTS, "bad-txns-inputs-missingorspent");
}
}
// This is const, but calls into the back end CoinsViews. The CCoinsViewDB at the bottom of the
// hierarchy brings the best block into scope. See CCoinsViewDB::GetBestBlock().
m_view.GetBestBlock();
// we have all inputs cached now, so switch back to dummy (to protect
// against bugs where we pull more inputs from disk that miss being added
// to coins_to_uncache)
m_view.SetBackend(m_dummy);
assert(m_active_chainstate.m_blockman.LookupBlockIndex(m_view.GetBestBlock()) == m_active_chainstate.m_chain.Tip());
// 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.
// Pass in m_view which has all of the relevant inputs cached. Note that, since m_view's
// backend was removed, it no longer pulls coins from the mempool.
if (!CheckSequenceLocksAtTip(m_active_chainstate.m_chain.Tip(), m_view, tx, &lp)) {
return state.Invalid(TxValidationResult::TX_PREMATURE_SPEND, "non-BIP68-final");
}
// The mempool holds txs for the next block, so pass height+1 to CheckTxInputs
if (!Consensus::CheckTxInputs(tx, state, m_view, m_active_chainstate.m_chain.Height() + 1, ws.m_base_fees)) {
return false; // state filled in by CheckTxInputs
}
if (m_pool.m_require_standard && !AreInputsStandard(tx, m_view)) {
return state.Invalid(TxValidationResult::TX_INPUTS_NOT_STANDARD, "bad-txns-nonstandard-inputs");
}
// Check for non-standard witnesses.
if (tx.HasWitness() && m_pool.m_require_standard && !IsWitnessStandard(tx, m_view)) {
return state.Invalid(TxValidationResult::TX_WITNESS_MUTATED, "bad-witness-nonstandard");
}
int64_t nSigOpsCost = GetTransactionSigOpCost(tx, m_view, STANDARD_SCRIPT_VERIFY_FLAGS);
// ws.m_modified_fees includes any fee deltas from PrioritiseTransaction
ws.m_modified_fees = ws.m_base_fees;
m_pool.ApplyDelta(hash, ws.m_modified_fees);
// Keep track of transactions that spend a coinbase, which we re-scan
// during reorgs to ensure COINBASE_MATURITY is still met.
bool fSpendsCoinbase = false;
for (const CTxIn &txin : tx.vin) {
const Coin &coin = m_view.AccessCoin(txin.prevout);
if (coin.IsCoinBase()) {
fSpendsCoinbase = true;
break;
}
}
entry.reset(new CTxMemPoolEntry(ptx, ws.m_base_fees, nAcceptTime, m_active_chainstate.m_chain.Height(),
fSpendsCoinbase, nSigOpsCost, lp));
ws.m_vsize = entry->GetTxSize();
if (nSigOpsCost > MAX_STANDARD_TX_SIGOPS_COST)
return state.Invalid(TxValidationResult::TX_NOT_STANDARD, "bad-txns-too-many-sigops",
strprintf("%d", nSigOpsCost));
// No individual transactions are allowed below the min relay feerate and mempool min feerate except from
// disconnected blocks and transactions in a package. Package transactions will be checked using
// package feerate later.
if (!bypass_limits && !args.m_package_feerates && !CheckFeeRate(ws.m_vsize, ws.m_modified_fees, state)) return false;
ws.m_iters_conflicting = m_pool.GetIterSet(ws.m_conflicts);
// Calculate in-mempool ancestors, up to a limit.
if (ws.m_conflicts.size() == 1) {
// In general, when we receive an RBF transaction with mempool conflicts, we want to know whether we
// would meet the chain limits after the conflicts have been removed. However, there isn't a practical
// way to do this short of calculating the ancestor and descendant sets with an overlay cache of
// changed mempool entries. Due to both implementation and runtime complexity concerns, this isn't
// very realistic, thus we only ensure a limited set of transactions are RBF'able despite mempool
// conflicts here. Importantly, we need to ensure that some transactions which were accepted using
// the below carve-out are able to be RBF'ed, without impacting the security the carve-out provides
// for off-chain contract systems (see link in the comment below).
//
// Specifically, the subset of RBF transactions which we allow despite chain limits are those which
// conflict directly with exactly one other transaction (but may evict children of said transaction),
// and which are not adding any new mempool dependencies. Note that the "no new mempool dependencies"
// check is accomplished later, so we don't bother doing anything about it here, but if our
// policy changes, we may need to move that check to here instead of removing it wholesale.
//
// Such transactions are clearly not merging any existing packages, so we are only concerned with
// ensuring that (a) no package is growing past the package size (not count) limits and (b) we are
// not allowing something to effectively use the (below) carve-out spot when it shouldn't be allowed
// to.
//
// To check these we first check if we meet the RBF criteria, above, and increment the descendant
// limits by the direct conflict and its descendants (as these are recalculated in
// CalculateMempoolAncestors by assuming the new transaction being added is a new descendant, with no
// removals, of each parent's existing dependent set). The ancestor count limits are unmodified (as
// the ancestor limits should be the same for both our new transaction and any conflicts).
// We don't bother incrementing m_limit_descendants by the full removal count as that limit never comes
// into force here (as we're only adding a single transaction).
assert(ws.m_iters_conflicting.size() == 1);
CTxMemPool::txiter conflict = *ws.m_iters_conflicting.begin();
m_limits.descendant_count += 1;
m_limits.descendant_size_vbytes += conflict->GetSizeWithDescendants();
}
auto ancestors{m_pool.CalculateMemPoolAncestors(*entry, m_limits)};
if (!ancestors) {
// If CalculateMemPoolAncestors fails second time, we want the original error string.
// Contracting/payment channels CPFP carve-out:
// If the new transaction is relatively small (up to 40k weight)
// and has at most one ancestor (ie ancestor limit of 2, including
// the new transaction), allow it if its parent has exactly the
// descendant limit descendants.
//
// This allows protocols which rely on distrusting counterparties
// being able to broadcast descendants of an unconfirmed transaction
// to be secure by simply only having two immediately-spendable
// outputs - one for each counterparty. For more info on the uses for
// this, see https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2018-November/016518.html
CTxMemPool::Limits cpfp_carve_out_limits{
.ancestor_count = 2,
.ancestor_size_vbytes = m_limits.ancestor_size_vbytes,
.descendant_count = m_limits.descendant_count + 1,
.descendant_size_vbytes = m_limits.descendant_size_vbytes + EXTRA_DESCENDANT_TX_SIZE_LIMIT,
};
const auto error_message{util::ErrorString(ancestors).original};
if (ws.m_vsize > EXTRA_DESCENDANT_TX_SIZE_LIMIT) {
return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "too-long-mempool-chain", error_message);
}
ancestors = m_pool.CalculateMemPoolAncestors(*entry, cpfp_carve_out_limits);
if (!ancestors) return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "too-long-mempool-chain", error_message);
}
ws.m_ancestors = *ancestors;
// 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 ws.m_conflicts and ws.m_ancestors don't
// intersect.
if (const auto err_string{EntriesAndTxidsDisjoint(ws.m_ancestors, ws.m_conflicts, hash)}) {
// We classify this as a consensus error because a transaction depending on something it
// conflicts with would be inconsistent.
return state.Invalid(TxValidationResult::TX_CONSENSUS, "bad-txns-spends-conflicting-tx", *err_string);
}
m_rbf = !ws.m_conflicts.empty();
return true;
}
bool MemPoolAccept::ReplacementChecks(Workspace& ws)
{
AssertLockHeld(cs_main);
AssertLockHeld(m_pool.cs);
const CTransaction& tx = *ws.m_ptx;
const uint256& hash = ws.m_hash;
TxValidationState& state = ws.m_state;
CFeeRate newFeeRate(ws.m_modified_fees, ws.m_vsize);
// Enforce Rule #6. The replacement transaction must have a higher feerate than its direct conflicts.
// - The motivation for this check is to ensure that the replacement transaction is preferable for
// block-inclusion, compared to what would be removed from the mempool.
// - This logic predates ancestor feerate-based transaction selection, which is why it doesn't
// consider feerates of descendants.
// - Note: Ancestor feerate-based transaction selection has made this comparison insufficient to
// guarantee that this is incentive-compatible for miners, because it is possible for a
// descendant transaction of a direct conflict to pay a higher feerate than the transaction that
// might replace them, under these rules.
if (const auto err_string{PaysMoreThanConflicts(ws.m_iters_conflicting, newFeeRate, hash)}) {
return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "insufficient fee", *err_string);
}
// Calculate all conflicting entries and enforce Rule #5.
if (const auto err_string{GetEntriesForConflicts(tx, m_pool, ws.m_iters_conflicting, ws.m_all_conflicting)}) {
return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY,
"too many potential replacements", *err_string);
}
// Enforce Rule #2.
if (const auto err_string{HasNoNewUnconfirmed(tx, m_pool, ws.m_iters_conflicting)}) {
return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY,
"replacement-adds-unconfirmed", *err_string);
}
// Check if it's economically rational to mine this transaction rather than the ones it
// replaces and pays for its own relay fees. Enforce Rules #3 and #4.
for (CTxMemPool::txiter it : ws.m_all_conflicting) {
ws.m_conflicting_fees += it->GetModifiedFee();
ws.m_conflicting_size += it->GetTxSize();
}
if (const auto err_string{PaysForRBF(ws.m_conflicting_fees, ws.m_modified_fees, ws.m_vsize,
m_pool.m_incremental_relay_feerate, hash)}) {
return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "insufficient fee", *err_string);
}
return true;
}
bool MemPoolAccept::PackageMempoolChecks(const std::vector<CTransactionRef>& txns,
PackageValidationState& package_state)
{
AssertLockHeld(cs_main);
AssertLockHeld(m_pool.cs);
// CheckPackageLimits expects the package transactions to not already be in the mempool.
assert(std::all_of(txns.cbegin(), txns.cend(), [this](const auto& tx)
{ return !m_pool.exists(GenTxid::Txid(tx->GetHash()));}));
std::string err_string;
if (!m_pool.CheckPackageLimits(txns, m_limits, err_string)) {
// This is a package-wide error, separate from an individual transaction error.
return package_state.Invalid(PackageValidationResult::PCKG_POLICY, "package-mempool-limits", err_string);
}
return true;
}
bool MemPoolAccept::PolicyScriptChecks(const ATMPArgs& args, Workspace& ws)
{
AssertLockHeld(cs_main);
AssertLockHeld(m_pool.cs);
const CTransaction& tx = *ws.m_ptx;
TxValidationState& state = ws.m_state;
constexpr unsigned int scriptVerifyFlags = STANDARD_SCRIPT_VERIFY_FLAGS;
// Check input scripts and signatures.
// This is done last to help prevent CPU exhaustion denial-of-service attacks.
if (!CheckInputScripts(tx, state, m_view, scriptVerifyFlags, true, false, ws.m_precomputed_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.
TxValidationState state_dummy; // Want reported failures to be from first CheckInputScripts
if (!tx.HasWitness() && CheckInputScripts(tx, state_dummy, m_view, scriptVerifyFlags & ~(SCRIPT_VERIFY_WITNESS | SCRIPT_VERIFY_CLEANSTACK), true, false, ws.m_precomputed_txdata) &&
!CheckInputScripts(tx, state_dummy, m_view, scriptVerifyFlags & ~SCRIPT_VERIFY_CLEANSTACK, true, false, ws.m_precomputed_txdata)) {
// Only the witness is missing, so the transaction itself may be fine.
state.Invalid(TxValidationResult::TX_WITNESS_STRIPPED,
state.GetRejectReason(), state.GetDebugMessage());
}
return false; // state filled in by CheckInputScripts
}
return true;
}
bool MemPoolAccept::ConsensusScriptChecks(const ATMPArgs& args, Workspace& ws)
{
AssertLockHeld(cs_main);
AssertLockHeld(m_pool.cs);
const CTransaction& tx = *ws.m_ptx;
const uint256& hash = ws.m_hash;
TxValidationState& state = ws.m_state;
// Check again against the current block tip's script verification
// flags to cache our script execution flags. This is, of course,
// useless if the next block has different script flags from the
// previous one, but because the cache tracks script flags for us it
// will auto-invalidate and we'll just have a few blocks of extra
// misses on soft-fork activation.
//
// This is also useful 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 (using TestBlockValidity), however allowing such
// transactions into the mempool can be exploited as a DoS attack.
unsigned int currentBlockScriptVerifyFlags{GetBlockScriptFlags(*m_active_chainstate.m_chain.Tip(), m_active_chainstate.m_chainman)};
if (!CheckInputsFromMempoolAndCache(tx, state, m_view, m_pool, currentBlockScriptVerifyFlags,
ws.m_precomputed_txdata, m_active_chainstate.CoinsTip())) {
LogPrintf("BUG! PLEASE REPORT THIS! CheckInputScripts failed against latest-block but not STANDARD flags %s, %s\n", hash.ToString(), state.ToString());
return Assume(false);
}
return true;
}
bool MemPoolAccept::Finalize(const ATMPArgs& args, Workspace& ws)
{
AssertLockHeld(cs_main);
AssertLockHeld(m_pool.cs);
const CTransaction& tx = *ws.m_ptx;
const uint256& hash = ws.m_hash;
TxValidationState& state = ws.m_state;
const bool bypass_limits = args.m_bypass_limits;
std::unique_ptr<CTxMemPoolEntry>& entry = ws.m_entry;
// Remove conflicting transactions from the mempool
for (CTxMemPool::txiter it : ws.m_all_conflicting)
{
LogPrint(BCLog::MEMPOOL, "replacing tx %s with %s for %s additional fees, %d delta bytes\n",
it->GetTx().GetHash().ToString(),
hash.ToString(),
FormatMoney(ws.m_modified_fees - ws.m_conflicting_fees),
(int)entry->GetTxSize() - (int)ws.m_conflicting_size);
ws.m_replaced_transactions.push_back(it->GetSharedTx());
}
m_pool.RemoveStaged(ws.m_all_conflicting, false, MemPoolRemovalReason::REPLACED);
// This transaction should only count for fee estimation if:
// - it's not being re-added during a reorg which bypasses typical mempool fee limits
// - the node is not behind
// - the transaction is not dependent on any other transactions in the mempool
// - it's not part of a package. Since package relay is not currently supported, this
// transaction has not necessarily been accepted to miners' mempools.
bool validForFeeEstimation = !bypass_limits && !args.m_package_submission && IsCurrentForFeeEstimation(m_active_chainstate) && m_pool.HasNoInputsOf(tx);
// Store transaction in memory
m_pool.addUnchecked(*entry, ws.m_ancestors, validForFeeEstimation);
// trim mempool and check if tx was trimmed
// If we are validating a package, don't trim here because we could evict a previous transaction
// in the package. LimitMempoolSize() should be called at the very end to make sure the mempool
// is still within limits and package submission happens atomically.
if (!args.m_package_submission && !bypass_limits) {
LimitMempoolSize(m_pool, m_active_chainstate.CoinsTip());
if (!m_pool.exists(GenTxid::Txid(hash)))
return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "mempool full");
}
return true;
}
bool MemPoolAccept::SubmitPackage(const ATMPArgs& args, std::vector<Workspace>& workspaces,
PackageValidationState& package_state,
std::map<const uint256, const MempoolAcceptResult>& results)
{
AssertLockHeld(cs_main);
AssertLockHeld(m_pool.cs);
// Sanity check: none of the transactions should be in the mempool, and none of the transactions
// should have a same-txid-different-witness equivalent in the mempool.
assert(std::all_of(workspaces.cbegin(), workspaces.cend(), [this](const auto& ws){
return !m_pool.exists(GenTxid::Txid(ws.m_ptx->GetHash())); }));
bool all_submitted = true;
// ConsensusScriptChecks adds to the script cache and is therefore consensus-critical;
// CheckInputsFromMempoolAndCache asserts that transactions only spend coins available from the
// mempool or UTXO set. Submit each transaction to the mempool immediately after calling
// ConsensusScriptChecks to make the outputs available for subsequent transactions.
for (Workspace& ws : workspaces) {
if (!ConsensusScriptChecks(args, ws)) {
results.emplace(ws.m_ptx->GetWitnessHash(), MempoolAcceptResult::Failure(ws.m_state));
// Since PolicyScriptChecks() passed, this should never fail.
Assume(false);
all_submitted = false;
package_state.Invalid(PackageValidationResult::PCKG_MEMPOOL_ERROR,
strprintf("BUG! PolicyScriptChecks succeeded but ConsensusScriptChecks failed: %s",
ws.m_ptx->GetHash().ToString()));
}
// Re-calculate mempool ancestors to call addUnchecked(). They may have changed since the
// last calculation done in PreChecks, since package ancestors have already been submitted.
{
auto ancestors{m_pool.CalculateMemPoolAncestors(*ws.m_entry, m_limits)};
if(!ancestors) {
results.emplace(ws.m_ptx->GetWitnessHash(), MempoolAcceptResult::Failure(ws.m_state));
// Since PreChecks() and PackageMempoolChecks() both enforce limits, this should never fail.
Assume(false);
all_submitted = false;
package_state.Invalid(PackageValidationResult::PCKG_MEMPOOL_ERROR,
strprintf("BUG! Mempool ancestors or descendants were underestimated: %s",
ws.m_ptx->GetHash().ToString()));
}
ws.m_ancestors = std::move(ancestors).value_or(ws.m_ancestors);
}
// If we call LimitMempoolSize() for each individual Finalize(), the mempool will not take
// the transaction's descendant feerate into account because it hasn't seen them yet. Also,
// we risk evicting a transaction that a subsequent package transaction depends on. Instead,
// allow the mempool to temporarily bypass limits, the maximum package size) while
// submitting transactions individually and then trim at the very end.
if (!Finalize(args, ws)) {
results.emplace(ws.m_ptx->GetWitnessHash(), MempoolAcceptResult::Failure(ws.m_state));
// Since LimitMempoolSize() won't be called, this should never fail.
Assume(false);
all_submitted = false;
package_state.Invalid(PackageValidationResult::PCKG_MEMPOOL_ERROR,
strprintf("BUG! Adding to mempool failed: %s", ws.m_ptx->GetHash().ToString()));
}
}
// It may or may not be the case that all the transactions made it into the mempool. Regardless,
// make sure we haven't exceeded max mempool size.
LimitMempoolSize(m_pool, m_active_chainstate.CoinsTip());
std::vector<uint256> all_package_wtxids;
all_package_wtxids.reserve(workspaces.size());
std::transform(workspaces.cbegin(), workspaces.cend(), std::back_inserter(all_package_wtxids),
[](const auto& ws) { return ws.m_ptx->GetWitnessHash(); });
// Find the wtxids of the transactions that made it into the mempool. Allow partial submission,
// but don't report success unless they all made it into the mempool.
for (Workspace& ws : workspaces) {
const auto effective_feerate = args.m_package_feerates ? ws.m_package_feerate :
CFeeRate{ws.m_modified_fees, static_cast<uint32_t>(ws.m_vsize)};
const auto effective_feerate_wtxids = args.m_package_feerates ? all_package_wtxids :
std::vector<uint256>({ws.m_ptx->GetWitnessHash()});
if (m_pool.exists(GenTxid::Wtxid(ws.m_ptx->GetWitnessHash()))) {
results.emplace(ws.m_ptx->GetWitnessHash(),
MempoolAcceptResult::Success(std::move(ws.m_replaced_transactions), ws.m_vsize,
ws.m_base_fees, effective_feerate, effective_feerate_wtxids));
GetMainSignals().TransactionAddedToMempool(ws.m_ptx, m_pool.GetAndIncrementSequence());
} else {
all_submitted = false;
ws.m_state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "mempool full");
results.emplace(ws.m_ptx->GetWitnessHash(), MempoolAcceptResult::Failure(ws.m_state));
}
}
return all_submitted;
}
MempoolAcceptResult MemPoolAccept::AcceptSingleTransaction(const CTransactionRef& ptx, ATMPArgs& args)
{
AssertLockHeld(cs_main);
LOCK(m_pool.cs); // mempool "read lock" (held through GetMainSignals().TransactionAddedToMempool())
Workspace ws(ptx);
if (!PreChecks(args, ws)) return MempoolAcceptResult::Failure(ws.m_state);
if (m_rbf && !ReplacementChecks(ws)) return MempoolAcceptResult::Failure(ws.m_state);
// Perform the inexpensive checks first and avoid hashing and signature verification unless
// those checks pass, to mitigate CPU exhaustion denial-of-service attacks.
if (!PolicyScriptChecks(args, ws)) return MempoolAcceptResult::Failure(ws.m_state);
if (!ConsensusScriptChecks(args, ws)) return MempoolAcceptResult::Failure(ws.m_state);
const CFeeRate effective_feerate{ws.m_modified_fees, static_cast<uint32_t>(ws.m_vsize)};
const std::vector<uint256> single_wtxid{ws.m_ptx->GetWitnessHash()};
// Tx was accepted, but not added
if (args.m_test_accept) {
return MempoolAcceptResult::Success(std::move(ws.m_replaced_transactions), ws.m_vsize,
ws.m_base_fees, effective_feerate, single_wtxid);
}
if (!Finalize(args, ws)) return MempoolAcceptResult::Failure(ws.m_state);
GetMainSignals().TransactionAddedToMempool(ptx, m_pool.GetAndIncrementSequence());
return MempoolAcceptResult::Success(std::move(ws.m_replaced_transactions), ws.m_vsize, ws.m_base_fees,
effective_feerate, single_wtxid);
}
PackageMempoolAcceptResult MemPoolAccept::AcceptMultipleTransactions(const std::vector<CTransactionRef>& txns, ATMPArgs& args)
{
AssertLockHeld(cs_main);
// These context-free package limits can be done before taking the mempool lock.
PackageValidationState package_state;
if (!CheckPackage(txns, package_state)) return PackageMempoolAcceptResult(package_state, {});
std::vector<Workspace> workspaces{};
workspaces.reserve(txns.size());
std::transform(txns.cbegin(), txns.cend(), std::back_inserter(workspaces),
[](const auto& tx) { return Workspace(tx); });
std::map<const uint256, const MempoolAcceptResult> results;
LOCK(m_pool.cs);
// Do all PreChecks first and fail fast to avoid running expensive script checks when unnecessary.
for (Workspace& ws : workspaces) {
if (!PreChecks(args, ws)) {
package_state.Invalid(PackageValidationResult::PCKG_TX, "transaction failed");
// Exit early to avoid doing pointless work. Update the failed tx result; the rest are unfinished.
results.emplace(ws.m_ptx->GetWitnessHash(), MempoolAcceptResult::Failure(ws.m_state));
return PackageMempoolAcceptResult(package_state, std::move(results));
}
// Make the coins created by this transaction available for subsequent transactions in the
// package to spend. Since we already checked conflicts in the package and we don't allow
// replacements, we don't need to track the coins spent. Note that this logic will need to be
// updated if package replace-by-fee is allowed in the future.
assert(!args.m_allow_replacement);
m_viewmempool.PackageAddTransaction(ws.m_ptx);
}
// Transactions must meet two minimum feerates: the mempool minimum fee and min relay fee.
// For transactions consisting of exactly one child and its parents, it suffices to use the
// package feerate (total modified fees / total virtual size) to check this requirement.
const auto m_total_vsize = std::accumulate(workspaces.cbegin(), workspaces.cend(), int64_t{0},
[](int64_t sum, auto& ws) { return sum + ws.m_vsize; });
const auto m_total_modified_fees = std::accumulate(workspaces.cbegin(), workspaces.cend(), CAmount{0},
[](CAmount sum, auto& ws) { return sum + ws.m_modified_fees; });
const CFeeRate package_feerate(m_total_modified_fees, m_total_vsize);
TxValidationState placeholder_state;
if (args.m_package_feerates &&
!CheckFeeRate(m_total_vsize, m_total_modified_fees, placeholder_state)) {
package_state.Invalid(PackageValidationResult::PCKG_POLICY, "package-fee-too-low");
return PackageMempoolAcceptResult(package_state, {});
}
// Apply package mempool ancestor/descendant limits. Skip if there is only one transaction,
// because it's unnecessary. Also, CPFP carve out can increase the limit for individual
// transactions, but this exemption is not extended to packages in CheckPackageLimits().
std::string err_string;
if (txns.size() > 1 && !PackageMempoolChecks(txns, package_state)) {
return PackageMempoolAcceptResult(package_state, std::move(results));
}
std::vector<uint256> all_package_wtxids;
all_package_wtxids.reserve(workspaces.size());
std::transform(workspaces.cbegin(), workspaces.cend(), std::back_inserter(all_package_wtxids),
[](const auto& ws) { return ws.m_ptx->GetWitnessHash(); });
for (Workspace& ws : workspaces) {
ws.m_package_feerate = package_feerate;
if (!PolicyScriptChecks(args, ws)) {
// Exit early to avoid doing pointless work. Update the failed tx result; the rest are unfinished.
package_state.Invalid(PackageValidationResult::PCKG_TX, "transaction failed");
results.emplace(ws.m_ptx->GetWitnessHash(), MempoolAcceptResult::Failure(ws.m_state));
return PackageMempoolAcceptResult(package_state, std::move(results));
}
if (args.m_test_accept) {
const auto effective_feerate = args.m_package_feerates ? ws.m_package_feerate :
CFeeRate{ws.m_modified_fees, static_cast<uint32_t>(ws.m_vsize)};
const auto effective_feerate_wtxids = args.m_package_feerates ? all_package_wtxids :
std::vector<uint256>{ws.m_ptx->GetWitnessHash()};
results.emplace(ws.m_ptx->GetWitnessHash(),
MempoolAcceptResult::Success(std::move(ws.m_replaced_transactions),
ws.m_vsize, ws.m_base_fees, effective_feerate,
effective_feerate_wtxids));
}
}
if (args.m_test_accept) return PackageMempoolAcceptResult(package_state, std::move(results));
if (!SubmitPackage(args, workspaces, package_state, results)) {
// PackageValidationState filled in by SubmitPackage().
return PackageMempoolAcceptResult(package_state, std::move(results));
}
return PackageMempoolAcceptResult(package_state, std::move(results));
}
PackageMempoolAcceptResult MemPoolAccept::AcceptPackage(const Package& package, ATMPArgs& args)
{
AssertLockHeld(cs_main);
// Used if returning a PackageMempoolAcceptResult directly from this function.
PackageValidationState package_state_quit_early;
// Check that the package is well-formed. If it isn't, we won't try to validate any of the
// transactions and thus won't return any MempoolAcceptResults, just a package-wide error.
// Context-free package checks.
if (!CheckPackage(package, package_state_quit_early)) return PackageMempoolAcceptResult(package_state_quit_early, {});
// All transactions in the package must be a parent of the last transaction. This is just an
// opportunity for us to fail fast on a context-free check without taking the mempool lock.
if (!IsChildWithParents(package)) {
package_state_quit_early.Invalid(PackageValidationResult::PCKG_POLICY, "package-not-child-with-parents");
return PackageMempoolAcceptResult(package_state_quit_early, {});
}
// IsChildWithParents() guarantees the package is > 1 transactions.
assert(package.size() > 1);
// The package must be 1 child with all of its unconfirmed parents. The package is expected to
// be sorted, so the last transaction is the child.
const auto& child = package.back();
std::unordered_set<uint256, SaltedTxidHasher> unconfirmed_parent_txids;
std::transform(package.cbegin(), package.cend() - 1,
std::inserter(unconfirmed_parent_txids, unconfirmed_parent_txids.end()),
[](const auto& tx) { return tx->GetHash(); });
// All child inputs must refer to a preceding package transaction or a confirmed UTXO. The only
// way to verify this is to look up the child's inputs in our current coins view (not including
// mempool), and enforce that all parents not present in the package be available at chain tip.
// Since this check can bring new coins into the coins cache, keep track of these coins and
// uncache them if we don't end up submitting this package to the mempool.
const CCoinsViewCache& coins_tip_cache = m_active_chainstate.CoinsTip();
for (const auto& input : child->vin) {
if (!coins_tip_cache.HaveCoinInCache(input.prevout)) {
args.m_coins_to_uncache.push_back(input.prevout);
}
}
// Using the MemPoolAccept m_view cache allows us to look up these same coins faster later.
// This should be connecting directly to CoinsTip, not to m_viewmempool, because we specifically
// require inputs to be confirmed if they aren't in the package.
m_view.SetBackend(m_active_chainstate.CoinsTip());
const auto package_or_confirmed = [this, &unconfirmed_parent_txids](const auto& input) {
return unconfirmed_parent_txids.count(input.prevout.hash) > 0 || m_view.HaveCoin(input.prevout);
};
if (!std::all_of(child->vin.cbegin(), child->vin.cend(), package_or_confirmed)) {
package_state_quit_early.Invalid(PackageValidationResult::PCKG_POLICY, "package-not-child-with-unconfirmed-parents");
return PackageMempoolAcceptResult(package_state_quit_early, {});
}
// Protect against bugs where we pull more inputs from disk that miss being added to
// coins_to_uncache. The backend will be connected again when needed in PreChecks.
m_view.SetBackend(m_dummy);
LOCK(m_pool.cs);
// Stores final results that won't change
std::map<const uint256, const MempoolAcceptResult> results_final;
// Node operators are free to set their mempool policies however they please, nodes may receive
// transactions in different orders, and malicious counterparties may try to take advantage of
// policy differences to pin or delay propagation of transactions. As such, it's possible for
// some package transaction(s) to already be in the mempool, and we don't want to reject the
// entire package in that case (as that could be a censorship vector). De-duplicate the
// transactions that are already in the mempool, and only call AcceptMultipleTransactions() with
// the new transactions. This ensures we don't double-count transaction counts and sizes when
// checking ancestor/descendant limits, or double-count transaction fees for fee-related policy.
ATMPArgs single_args = ATMPArgs::SingleInPackageAccept(args);
// Results from individual validation. "Nonfinal" because if a transaction fails by itself but
// succeeds later (i.e. when evaluated with a fee-bumping child), the result changes (though not
// reflected in this map). If a transaction fails more than once, we want to return the first
// result, when it was considered on its own. So changes will only be from invalid -> valid.
std::map<uint256, MempoolAcceptResult> individual_results_nonfinal;
bool quit_early{false};
std::vector<CTransactionRef> txns_package_eval;
for (const auto& tx : package) {
const auto& wtxid = tx->GetWitnessHash();
const auto& txid = tx->GetHash();
// There are 3 possibilities: already in mempool, same-txid-diff-wtxid already in mempool,
// or not in mempool. An already confirmed tx is treated as one not in mempool, because all
// we know is that the inputs aren't available.
if (m_pool.exists(GenTxid::Wtxid(wtxid))) {
// Exact transaction already exists in the mempool.
auto iter = m_pool.GetIter(txid);
assert(iter != std::nullopt);
results_final.emplace(wtxid, MempoolAcceptResult::MempoolTx(iter.value()->GetTxSize(), iter.value()->GetFee()));
} else if (m_pool.exists(GenTxid::Txid(txid))) {
// Transaction with the same non-witness data but different witness (same txid,
// different wtxid) already exists in the mempool.
//
// We don't allow replacement transactions right now, so just swap the package
// transaction for the mempool one. Note that we are ignoring the validity of the
// package transaction passed in.
// TODO: allow witness replacement in packages.
auto iter = m_pool.GetIter(txid);
assert(iter != std::nullopt);
// Provide the wtxid of the mempool tx so that the caller can look it up in the mempool.
results_final.emplace(wtxid, MempoolAcceptResult::MempoolTxDifferentWitness(iter.value()->GetTx().GetWitnessHash()));
} else {
// Transaction does not already exist in the mempool.
// Try submitting the transaction on its own.
const auto single_res = AcceptSingleTransaction(tx, single_args);
if (single_res.m_result_type == MempoolAcceptResult::ResultType::VALID) {
// The transaction succeeded on its own and is now in the mempool. Don't include it
// in package validation, because its fees should only be "used" once.
assert(m_pool.exists(GenTxid::Wtxid(wtxid)));
results_final.emplace(wtxid, single_res);
} else if (single_res.m_state.GetResult() != TxValidationResult::TX_MEMPOOL_POLICY &&
single_res.m_state.GetResult() != TxValidationResult::TX_MISSING_INPUTS) {
// Package validation policy only differs from individual policy in its evaluation
// of feerate. For example, if a transaction fails here due to violation of a
// consensus rule, the result will not change when it is submitted as part of a
// package. To minimize the amount of repeated work, unless the transaction fails
// due to feerate or missing inputs (its parent is a previous transaction in the
// package that failed due to feerate), don't run package validation. Note that this
// decision might not make sense if different types of packages are allowed in the
// future. Continue individually validating the rest of the transactions, because
// some of them may still be valid.
quit_early = true;
package_state_quit_early.Invalid(PackageValidationResult::PCKG_TX, "transaction failed");
individual_results_nonfinal.emplace(wtxid, single_res);
} else {
individual_results_nonfinal.emplace(wtxid, single_res);
txns_package_eval.push_back(tx);
}
}
}
// Quit early because package validation won't change the result or the entire package has
// already been submitted.
if (quit_early || txns_package_eval.empty()) {
for (const auto& [wtxid, mempoolaccept_res] : individual_results_nonfinal) {
Assume(results_final.emplace(wtxid, mempoolaccept_res).second);
Assume(mempoolaccept_res.m_result_type == MempoolAcceptResult::ResultType::INVALID);
}
return PackageMempoolAcceptResult(package_state_quit_early, std::move(results_final));
}
// Validate the (deduplicated) transactions as a package. Note that submission_result has its
// own PackageValidationState; package_state_quit_early is unused past this point.
auto submission_result = AcceptMultipleTransactions(txns_package_eval, args);
// Include already-in-mempool transaction results in the final result.
for (const auto& [wtxid, mempoolaccept_res] : results_final) {
Assume(submission_result.m_tx_results.emplace(wtxid, mempoolaccept_res).second);
Assume(mempoolaccept_res.m_result_type != MempoolAcceptResult::ResultType::INVALID);
}
if (submission_result.m_state.GetResult() == PackageValidationResult::PCKG_TX) {
// Package validation failed because one or more transactions failed. Provide a result for
// each transaction; if AcceptMultipleTransactions() didn't return a result for a tx,
// include the previous individual failure reason.
submission_result.m_tx_results.insert(individual_results_nonfinal.cbegin(),
individual_results_nonfinal.cend());
Assume(submission_result.m_tx_results.size() == package.size());
}
return submission_result;
}
} // anon namespace
MempoolAcceptResult AcceptToMemoryPool(Chainstate& active_chainstate, const CTransactionRef& tx,
int64_t accept_time, bool bypass_limits, bool test_accept)
EXCLUSIVE_LOCKS_REQUIRED(::cs_main)
{
AssertLockHeld(::cs_main);
const CChainParams& chainparams{active_chainstate.m_chainman.GetParams()};
assert(active_chainstate.GetMempool() != nullptr);
CTxMemPool& pool{*active_chainstate.GetMempool()};
std::vector<COutPoint> coins_to_uncache;
auto args = MemPoolAccept::ATMPArgs::SingleAccept(chainparams, accept_time, bypass_limits, coins_to_uncache, test_accept);
MempoolAcceptResult result = MemPoolAccept(pool, active_chainstate).AcceptSingleTransaction(tx, args);
if (result.m_result_type != MempoolAcceptResult::ResultType::VALID) {
// Remove coins that were not present in the coins cache before calling
// AcceptSingleTransaction(); this is to prevent memory DoS in case we receive a large
// number of invalid transactions that attempt to overrun the in-memory coins cache
// (`CCoinsViewCache::cacheCoins`).
for (const COutPoint& hashTx : coins_to_uncache)
active_chainstate.CoinsTip().Uncache(hashTx);
}
// After we've (potentially) uncached entries, ensure our coins cache is still within its size limits
BlockValidationState state_dummy;
active_chainstate.FlushStateToDisk(state_dummy, FlushStateMode::PERIODIC);
return result;
}
PackageMempoolAcceptResult ProcessNewPackage(Chainstate& active_chainstate, CTxMemPool& pool,
const Package& package, bool test_accept)
{
AssertLockHeld(cs_main);
assert(!package.empty());
assert(std::all_of(package.cbegin(), package.cend(), [](const auto& tx){return tx != nullptr;}));
std::vector<COutPoint> coins_to_uncache;
const CChainParams& chainparams = active_chainstate.m_chainman.GetParams();
auto result = [&]() EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
AssertLockHeld(cs_main);
if (test_accept) {
auto args = MemPoolAccept::ATMPArgs::PackageTestAccept(chainparams, GetTime(), coins_to_uncache);
return MemPoolAccept(pool, active_chainstate).AcceptMultipleTransactions(package, args);
} else {
auto args = MemPoolAccept::ATMPArgs::PackageChildWithParents(chainparams, GetTime(), coins_to_uncache);
return MemPoolAccept(pool, active_chainstate).AcceptPackage(package, args);
}
}();
// Uncache coins pertaining to transactions that were not submitted to the mempool.
if (test_accept || result.m_state.IsInvalid()) {
for (const COutPoint& hashTx : coins_to_uncache) {
active_chainstate.CoinsTip().Uncache(hashTx);
}
}
// Ensure the coins cache is still within limits.
BlockValidationState state_dummy;
active_chainstate.FlushStateToDisk(state_dummy, FlushStateMode::PERIODIC);
return result;
}
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;
}
CoinsViews::CoinsViews(
fs::path ldb_name,
size_t cache_size_bytes,
bool in_memory,
bool should_wipe) : m_dbview(
gArgs.GetDataDirNet() / ldb_name, cache_size_bytes, in_memory, should_wipe),
m_catcherview(&m_dbview) {}
void CoinsViews::InitCache()
{
AssertLockHeld(::cs_main);
m_cacheview = std::make_unique<CCoinsViewCache>(&m_catcherview);
}
Chainstate::Chainstate(
CTxMemPool* mempool,
BlockManager& blockman,
ChainstateManager& chainman,
std::optional<uint256> from_snapshot_blockhash)
: m_mempool(mempool),
m_blockman(blockman),
m_chainman(chainman),
m_from_snapshot_blockhash(from_snapshot_blockhash) {}
void Chainstate::InitCoinsDB(
size_t cache_size_bytes,
bool in_memory,
bool should_wipe,
fs::path leveldb_name)
{
if (m_from_snapshot_blockhash) {
leveldb_name += node::SNAPSHOT_CHAINSTATE_SUFFIX;
}
m_coins_views = std::make_unique<CoinsViews>(
leveldb_name, cache_size_bytes, in_memory, should_wipe);
}
void Chainstate::InitCoinsCache(size_t cache_size_bytes)
{
AssertLockHeld(::cs_main);
assert(m_coins_views != nullptr);
m_coinstip_cache_size_bytes = cache_size_bytes;
m_coins_views->InitCache();
}
// Note that though this is marked const, we may end up modifying `m_cached_finished_ibd`, which
// is a performance-related implementation detail. This function must be marked
// `const` so that `CValidationInterface` clients (which are given a `const Chainstate*`)
// can call it.
//
bool Chainstate::IsInitialBlockDownload() const
{
// Optimization: pre-test latch before taking the lock.
if (m_cached_finished_ibd.load(std::memory_order_relaxed))
return false;
LOCK(cs_main);
if (m_cached_finished_ibd.load(std::memory_order_relaxed))
return false;
if (fImporting || fReindex)
return true;
if (m_chain.Tip() == nullptr)
return true;
if (m_chain.Tip()->nChainWork < m_chainman.MinimumChainWork()) {
return true;
}
if (m_chain.Tip()->Time() < Now<NodeSeconds>() - m_chainman.m_options.max_tip_age) {
return true;
}
LogPrintf("Leaving InitialBlockDownload (latching to false)\n");
m_cached_finished_ibd.store(true, std::memory_order_relaxed);
return false;
}
static void AlertNotify(const std::string& strMessage)
{
uiInterface.NotifyAlertChanged();
#if HAVE_SYSTEM
std::string strCmd = gArgs.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;
ReplaceAll(strCmd, "%s", safeStatus);
std::thread t(runCommand, strCmd);
t.detach(); // thread runs free
#endif
}
void Chainstate::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 (m_chainman.m_best_invalid && m_chainman.m_best_invalid->nChainWork > m_chain.Tip()->nChainWork + (GetBlockProof(*m_chain.Tip()) * 6)) {
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 {
SetfLargeWorkInvalidChainFound(false);
}
}
// Called both upon regular invalid block discovery *and* InvalidateBlock
void Chainstate::InvalidChainFound(CBlockIndex* pindexNew)
{
AssertLockHeld(cs_main);
if (!m_chainman.m_best_invalid || pindexNew->nChainWork > m_chainman.m_best_invalid->nChainWork) {
m_chainman.m_best_invalid = pindexNew;
}
if (m_chainman.m_best_header != nullptr && m_chainman.m_best_header->GetAncestor(pindexNew->nHeight) == pindexNew) {
m_chainman.m_best_header = m_chain.Tip();
}
LogPrintf("%s: invalid block=%s height=%d log2_work=%f date=%s\n", __func__,
pindexNew->GetBlockHash().ToString(), pindexNew->nHeight,
log(pindexNew->nChainWork.getdouble())/log(2.0), FormatISO8601DateTime(pindexNew->GetBlockTime()));
CBlockIndex *tip = m_chain.Tip();
assert (tip);
LogPrintf("%s: current best=%s height=%d log2_work=%f date=%s\n", __func__,
tip->GetBlockHash().ToString(), m_chain.Height(), log(tip->nChainWork.getdouble())/log(2.0),
FormatISO8601DateTime(tip->GetBlockTime()));
CheckForkWarningConditions();
}
// Same as InvalidChainFound, above, except not called directly from InvalidateBlock,
// which does its own setBlockIndexCandidates management.
void Chainstate::InvalidBlockFound(CBlockIndex* pindex, const BlockValidationState& state)
{
AssertLockHeld(cs_main);
if (state.GetResult() != BlockValidationResult::BLOCK_MUTATED) {
pindex->nStatus |= BLOCK_FAILED_VALID;
m_chainman.m_failed_blocks.insert(pindex);
m_blockman.m_dirty_blockindex.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());
for (const CTxIn &txin : tx.vin) {
txundo.vprevout.emplace_back();
bool is_spent = inputs.SpendCoin(txin.prevout, &txundo.vprevout.back());
assert(is_spent);
}
}
// add outputs
AddCoins(inputs, tx, nHeight);
}
bool CScriptCheck::operator()() {
const CScript &scriptSig = ptxTo->vin[nIn].scriptSig;
const CScriptWitness *witness = &ptxTo->vin[nIn].scriptWitness;
return VerifyScript(scriptSig, m_tx_out.scriptPubKey, witness, nFlags, CachingTransactionSignatureChecker(ptxTo, nIn, m_tx_out.nValue, cacheStore, *txdata), &error);
}
static CuckooCache::cache<uint256, SignatureCacheHasher> g_scriptExecutionCache;
static CSHA256 g_scriptExecutionCacheHasher;
bool InitScriptExecutionCache(size_t max_size_bytes)
{
// Setup the salted hasher
uint256 nonce = GetRandHash();
// We want the nonce to be 64 bytes long to force the hasher to process
// this chunk, which makes later hash computations more efficient. We
// just write our 32-byte entropy twice to fill the 64 bytes.
g_scriptExecutionCacheHasher.Write(nonce.begin(), 32);
g_scriptExecutionCacheHasher.Write(nonce.begin(), 32);
auto setup_results = g_scriptExecutionCache.setup_bytes(max_size_bytes);
if (!setup_results) return false;
const auto [num_elems, approx_size_bytes] = *setup_results;
LogPrintf("Using %zu MiB out of %zu MiB requested for script execution cache, able to store %zu elements\n",
approx_size_bytes >> 20, max_size_bytes >> 20, num_elems);
return true;
}
/**
* Check whether all of this transaction's input scripts succeed.
*
* This involves ECDSA signature checks so can be computationally intensive. This function should
* only be called after the cheap sanity checks in CheckTxInputs passed.
*
* If pvChecks is not nullptr, script checks are pushed onto it instead of being performed inline. Any
* script checks which are not necessary (eg due to script execution cache hits) are, obviously,
* not pushed onto pvChecks/run.
*
* Setting cacheSigStore/cacheFullScriptStore to false will remove elements from the corresponding cache
* which are matched. This is useful for checking blocks where we will likely never need the cache
* entry again.
*
* Note that we may set state.reason to NOT_STANDARD for extra soft-fork flags in flags, block-checking
* callers should probably reset it to CONSENSUS in such cases.
*
* Non-static (and re-declared) in src/test/txvalidationcache_tests.cpp
*/
bool CheckInputScripts(const CTransaction& tx, TxValidationState& state,
const CCoinsViewCache& inputs, unsigned int flags, bool cacheSigStore,
bool cacheFullScriptStore, PrecomputedTransactionData& txdata,
std::vector<CScriptCheck>* pvChecks)
{
if (tx.IsCoinBase()) return true;
if (pvChecks) {
pvChecks->reserve(tx.vin.size());
}
// First check if script executions have been cached with the same
// flags. Note that this assumes that the inputs provided are
// correct (ie that the transaction hash which is in tx's prevouts
// properly commits to the scriptPubKey in the inputs view of that
// transaction).
uint256 hashCacheEntry;
CSHA256 hasher = g_scriptExecutionCacheHasher;
hasher.Write(tx.GetWitnessHash().begin(), 32).Write((unsigned char*)&flags, sizeof(flags)).Finalize(hashCacheEntry.begin());
AssertLockHeld(cs_main); //TODO: Remove this requirement by making CuckooCache not require external locks
if (g_scriptExecutionCache.contains(hashCacheEntry, !cacheFullScriptStore)) {
return true;
}
if (!txdata.m_spent_outputs_ready) {
std::vector<CTxOut> spent_outputs;
spent_outputs.reserve(tx.vin.size());
for (const auto& txin : tx.vin) {
const COutPoint& prevout = txin.prevout;
const Coin& coin = inputs.AccessCoin(prevout);
assert(!coin.IsSpent());
spent_outputs.emplace_back(coin.out);
}
txdata.Init(tx, std::move(spent_outputs));
}
assert(txdata.m_spent_outputs.size() == tx.vin.size());
for (unsigned int i = 0; i < tx.vin.size(); i++) {
// We very carefully only pass in things to CScriptCheck which
// are clearly committed to by tx' witness hash. This provides
// a sanity check that our caching is not introducing consensus
// failures through additional data in, eg, the coins being
// spent being checked as a part of CScriptCheck.
// Verify signature
CScriptCheck check(txdata.m_spent_outputs[i], tx, i, flags, cacheSigStore, &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, ensure we return NOT_STANDARD
// instead of CONSENSUS to avoid downstream users
// splitting the network between upgraded and
// non-upgraded nodes by banning CONSENSUS-failing
// data providers.
CScriptCheck check2(txdata.m_spent_outputs[i], tx, i,
flags & ~STANDARD_NOT_MANDATORY_VERIFY_FLAGS, cacheSigStore, &txdata);
if (check2())
return state.Invalid(TxValidationResult::TX_NOT_STANDARD, strprintf("non-mandatory-script-verify-flag (%s)", ScriptErrorString(check.GetScriptError())));
}
// MANDATORY flag failures correspond to
// TxValidationResult::TX_CONSENSUS. Because CONSENSUS
// failures are the most serious case of validation
// failures, we may need to consider using
// RECENT_CONSENSUS_CHANGE for any script failure that
// could be due to non-upgraded nodes which we may want to
// support, to avoid splitting the network (but this
// depends on the details of how net_processing handles
// such errors).
return state.Invalid(TxValidationResult::TX_CONSENSUS, strprintf("mandatory-script-verify-flag-failed (%s)", ScriptErrorString(check.GetScriptError())));
}
}
if (cacheFullScriptStore && !pvChecks) {
// We executed all of the provided scripts, and were told to
// cache the result. Do so now.
g_scriptExecutionCache.insert(hashCacheEntry);
}
return true;
}
bool AbortNode(BlockValidationState& state, const std::string& strMessage, const bilingual_str& userMessage)
{
AbortNode(strMessage, userMessage);
return state.Error(strMessage);
}
/**
* Restore the UTXO in a Coin at a given COutPoint
* @param undo The Coin to be restored.
* @param view The coins view to which to apply the changes.
* @param out The out point that corresponds to the tx input.
* @return A DisconnectResult as an int
*/
int ApplyTxInUndo(Coin&& undo, CCoinsViewCache& view, const COutPoint& out)
{
bool fClean = true;
if (view.HaveCoin(out)) fClean = false; // overwriting transaction output
if (undo.nHeight == 0) {
// Missing undo metadata (height and coinbase). Older versions included this
// information only in undo records for the last spend of a transactions'
// outputs. This implies that it must be present for some other output of the same tx.
const Coin& alternate = AccessByTxid(view, out.hash);
if (!alternate.IsSpent()) {
undo.nHeight = alternate.nHeight;
undo.fCoinBase = alternate.fCoinBase;
} else {
return DISCONNECT_FAILED; // adding output for transaction without known metadata
}
}
// If the coin already exists as an unspent coin in the cache, then the
// possible_overwrite parameter to AddCoin must be set to true. We have
// already checked whether an unspent coin exists above using HaveCoin, so
// we don't need to guess. When fClean is false, an unspent coin already
// existed and it is an overwrite.
view.AddCoin(out, std::move(undo), !fClean);
return fClean ? DISCONNECT_OK : DISCONNECT_UNCLEAN;
}
/** Undo the effects of this block (with given index) on the UTXO set represented by coins.
* When FAILED is returned, view is left in an indeterminate state. */
DisconnectResult Chainstate::DisconnectBlock(const CBlock& block, const CBlockIndex* pindex, CCoinsViewCache& view)
{
AssertLockHeld(::cs_main);
bool fClean = true;
CBlockUndo blockUndo;
if (!UndoReadFromDisk(blockUndo, pindex)) {
error("DisconnectBlock(): failure reading undo data");
return DISCONNECT_FAILED;
}
if (blockUndo.vtxundo.size() + 1 != block.vtx.size()) {
error("DisconnectBlock(): block and undo data inconsistent");
return DISCONNECT_FAILED;
}
// Ignore blocks that contain transactions which are 'overwritten' by later transactions,
// unless those are already completely spent.
// See https://github.com/bitcoin/bitcoin/issues/22596 for additional information.
// Note: the blocks specified here are different than the ones used in ConnectBlock because DisconnectBlock
// unwinds the blocks in reverse. As a result, the inconsistency is not discovered until the earlier
// blocks with the duplicate coinbase transactions are disconnected.
bool fEnforceBIP30 = !((pindex->nHeight==91722 && pindex->GetBlockHash() == uint256S("0x00000000000271a2dc26e7667f8419f2e15416dc6955e5a6c6cdf3f2574dd08e")) ||
(pindex->nHeight==91812 && pindex->GetBlockHash() == uint256S("0x00000000000af0aed4792b1acee3d966af36cf5def14935db8de83d6f9306f2f")));
// 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();
bool is_coinbase = tx.IsCoinBase();
bool is_bip30_exception = (is_coinbase && !fEnforceBIP30);
// Check that all outputs are available and match the outputs in the block itself
// exactly.
for (size_t o = 0; o < tx.vout.size(); o++) {
if (!tx.vout[o].scriptPubKey.IsUnspendable()) {
COutPoint out(hash, o);
Coin coin;
bool is_spent = view.SpendCoin(out, &coin);
if (!is_spent || tx.vout[o] != coin.out || pindex->nHeight != coin.nHeight || is_coinbase != coin.fCoinBase) {
if (!is_bip30_exception) {
fClean = false; // transaction output mismatch
}
}
}
}
// restore inputs
if (i > 0) { // not coinbases
CTxUndo &txundo = blockUndo.vtxundo[i-1];
if (txundo.vprevout.size() != tx.vin.size()) {
error("DisconnectBlock(): transaction and undo data inconsistent");
return DISCONNECT_FAILED;
}
for (unsigned int j = tx.vin.size(); j > 0;) {
--j;
const COutPoint& out = tx.vin[j].prevout;
int res = ApplyTxInUndo(std::move(txundo.vprevout[j]), view, out);
if (res == DISCONNECT_FAILED) return DISCONNECT_FAILED;
fClean = fClean && res != DISCONNECT_UNCLEAN;
}
// At this point, all of txundo.vprevout should have been moved out.
}
}
// move best block pointer to prevout block
view.SetBestBlock(pindex->pprev->GetBlockHash());
return fClean ? DISCONNECT_OK : DISCONNECT_UNCLEAN;
}
static CCheckQueue<CScriptCheck> scriptcheckqueue(128);
void StartScriptCheckWorkerThreads(int threads_num)
{
scriptcheckqueue.StartWorkerThreads(threads_num);
}
void StopScriptCheckWorkerThreads()
{
scriptcheckqueue.StopWorkerThreads();
}
/**
* Threshold condition checker that triggers when unknown versionbits are seen on the network.
*/
class WarningBitsConditionChecker : public AbstractThresholdConditionChecker
{
private:
const ChainstateManager& m_chainman;
int m_bit;
public:
explicit WarningBitsConditionChecker(const ChainstateManager& chainman, int bit) : m_chainman{chainman}, m_bit(bit) {}
int64_t BeginTime(const Consensus::Params& params) const override { return 0; }
int64_t EndTime(const Consensus::Params& params) const override { return std::numeric_limits<int64_t>::max(); }
int Period(const Consensus::Params& params) const override { return params.nMinerConfirmationWindow; }
int Threshold(const Consensus::Params& params) const override { return params.nRuleChangeActivationThreshold; }
bool Condition(const CBlockIndex* pindex, const Consensus::Params& params) const override
{
return pindex->nHeight >= params.MinBIP9WarningHeight &&
((pindex->nVersion & VERSIONBITS_TOP_MASK) == VERSIONBITS_TOP_BITS) &&
((pindex->nVersion >> m_bit) & 1) != 0 &&
((m_chainman.m_versionbitscache.ComputeBlockVersion(pindex->pprev, params) >> m_bit) & 1) == 0;
}
};
static std::array<ThresholdConditionCache, VERSIONBITS_NUM_BITS> warningcache GUARDED_BY(cs_main);
static unsigned int GetBlockScriptFlags(const CBlockIndex& block_index, const ChainstateManager& chainman)
{
const Consensus::Params& consensusparams = chainman.GetConsensus();
// BIP16 didn't become active until Apr 1 2012 (on mainnet, and
// retroactively applied to testnet)
// However, only one historical block violated the P2SH rules (on both
// mainnet and testnet).
// Similarly, only one historical block violated the TAPROOT rules on
// mainnet.
// For simplicity, always leave P2SH+WITNESS+TAPROOT on except for the two
// violating blocks.
uint32_t flags{SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_WITNESS | SCRIPT_VERIFY_TAPROOT};
const auto it{consensusparams.script_flag_exceptions.find(*Assert(block_index.phashBlock))};
if (it != consensusparams.script_flag_exceptions.end()) {
flags = it->second;
}
// Enforce the DERSIG (BIP66) rule
if (DeploymentActiveAt(block_index, chainman, Consensus::DEPLOYMENT_DERSIG)) {
flags |= SCRIPT_VERIFY_DERSIG;
}
// Enforce CHECKLOCKTIMEVERIFY (BIP65)
if (DeploymentActiveAt(block_index, chainman, Consensus::DEPLOYMENT_CLTV)) {
flags |= SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY;
}
// Enforce CHECKSEQUENCEVERIFY (BIP112)
if (DeploymentActiveAt(block_index, chainman, Consensus::DEPLOYMENT_CSV)) {
flags |= SCRIPT_VERIFY_CHECKSEQUENCEVERIFY;
}
// Enforce BIP147 NULLDUMMY (activated simultaneously with segwit)
if (DeploymentActiveAt(block_index, chainman, Consensus::DEPLOYMENT_SEGWIT)) {
flags |= SCRIPT_VERIFY_NULLDUMMY;
}
return flags;
}
static SteadyClock::duration time_check{};
static SteadyClock::duration time_forks{};
static SteadyClock::duration time_connect{};
static SteadyClock::duration time_verify{};
static SteadyClock::duration time_undo{};
static SteadyClock::duration time_index{};
static SteadyClock::duration time_total{};
static int64_t num_blocks_total = 0;
/** Apply the effects of this block (with given index) on the UTXO set represented by coins.
* Validity checks that depend on the UTXO set are also done; ConnectBlock()
* can fail if those validity checks fail (among other reasons). */
bool Chainstate::ConnectBlock(const CBlock& block, BlockValidationState& state, CBlockIndex* pindex,
CCoinsViewCache& view, bool fJustCheck)
{
AssertLockHeld(cs_main);
assert(pindex);
uint256 block_hash{block.GetHash()};
assert(*pindex->phashBlock == block_hash);
const bool parallel_script_checks{scriptcheckqueue.HasThreads()};
const auto time_start{SteadyClock::now()};
const CChainParams& params{m_chainman.GetParams()};
// Check it again in case a previous version let a bad block in
// NOTE: We don't currently (re-)invoke ContextualCheckBlock() or
// ContextualCheckBlockHeader() here. This means that if we add a new
// consensus rule that is enforced in one of those two functions, then we
// may have let in a block that violates the rule prior to updating the
// software, and we would NOT be enforcing the rule here. Fully solving
// upgrade from one software version to the next after a consensus rule
// change is potentially tricky and issue-specific (see NeedsRedownload()
// for one approach that was used for BIP 141 deployment).
// Also, currently the rule against blocks more than 2 hours in the future
// is enforced in ContextualCheckBlockHeader(); we wouldn't want to
// re-enforce that rule here (at least until we make it impossible for
// m_adjusted_time_callback() to go backward).
if (!CheckBlock(block, state, params.GetConsensus(), !fJustCheck, !fJustCheck)) {
if (state.GetResult() == BlockValidationResult::BLOCK_MUTATED) {
// We don't write down blocks to disk if they may have been
// corrupted, so this should be impossible unless we're having hardware
// problems.
return AbortNode(state, "Corrupt block found indicating potential hardware failure; shutting down");
}
return error("%s: Consensus::CheckBlock: %s", __func__, state.ToString());
}
// verify that the view's current state corresponds to the previous block
uint256 hashPrevBlock = pindex->pprev == nullptr ? uint256() : pindex->pprev->GetBlockHash();
assert(hashPrevBlock == view.GetBestBlock());
num_blocks_total++;
// Special case for the genesis block, skipping connection of its transactions
// (its coinbase is unspendable)
if (block_hash == params.GetConsensus().hashGenesisBlock) {
if (!fJustCheck)
view.SetBestBlock(pindex->GetBlockHash());
return true;
}
bool fScriptChecks = true;
if (!m_chainman.AssumedValidBlock().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{m_blockman.m_block_index.find(m_chainman.AssumedValidBlock())};
if (it != m_blockman.m_block_index.end()) {
if (it->second.GetAncestor(pindex->nHeight) == pindex &&
m_chainman.m_best_header->GetAncestor(pindex->nHeight) == pindex &&
m_chainman.m_best_header->nChainWork >= m_chainman.MinimumChainWork()) {
// This block is a member of the assumed verified chain and an ancestor of the best header.
// Script verification is skipped when connecting blocks under the
// assumevalid block. Assuming the assumevalid 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.
// The equivalent time check discourages hash power 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 the minimum chain work prevents the skipping when denied access to any chain at
// least as good as the expected chain.
fScriptChecks = (GetBlockProofEquivalentTime(*m_chainman.m_best_header, *pindex, *m_chainman.m_best_header, params.GetConsensus()) <= 60 * 60 * 24 * 7 * 2);
}
}
}
const auto time_1{SteadyClock::now()};
time_check += time_1 - time_start;
LogPrint(BCLog::BENCH, " - Sanity checks: %.2fms [%.2fs (%.2fms/blk)]\n",
Ticks<MillisecondsDouble>(time_1 - time_start),
Ticks<SecondsDouble>(time_check),
Ticks<MillisecondsDouble>(time_check) / num_blocks_total);
// 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, CVE-2012-1909, and http://r6.ca/blog/20120206T005236Z.html for more information.
// 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 = !IsBIP30Repeat(*pindex);
// 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 it's 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.
// BIP34 requires that a block at height X (block X) has its coinbase
// scriptSig start with a CScriptNum of X (indicated height X). The above
// logic of no longer requiring BIP30 once BIP34 activates is flawed in the
// case that there is a block X before the BIP34 height of 227,931 which has
// an indicated height Y where Y is greater than X. The coinbase for block
// X would also be a valid coinbase for block Y, which could be a BIP30
// violation. An exhaustive search of all mainnet coinbases before the
// BIP34 height which have an indicated height greater than the block height
// reveals many occurrences. The 3 lowest indicated heights found are
// 209,921, 490,897, and 1,983,702 and thus coinbases for blocks at these 3
// heights would be the first opportunity for BIP30 to be violated.
// The search reveals a great many blocks which have an indicated height
// greater than 1,983,702, so we simply remove the optimization to skip
// BIP30 checking for blocks at height 1,983,702 or higher. Before we reach
// that block in another 25 years or so, we should take advantage of a
// future consensus change to do a new and improved version of BIP34 that
// will actually prevent ever creating any duplicate coinbases in the
// future.
static constexpr int BIP34_IMPLIES_BIP30_LIMIT = 1983702;
// There is no potential to create a duplicate coinbase at block 209,921
// because this is still before the BIP34 height and so explicit BIP30
// checking is still active.
// The final case is block 176,684 which has an indicated height of
// 490,897. Unfortunately, this issue was not discovered until about 2 weeks
// before block 490,897 so there was not much opportunity to address this
// case other than to carefully analyze it and determine it would not be a
// problem. Block 490,897 was, in fact, mined with a different coinbase than
// block 176,684, but it is important to note that even if it hadn't been or
// is remined on an alternate fork with a duplicate coinbase, we would still
// not run into a BIP30 violation. This is because the coinbase for 176,684
// is spent in block 185,956 in transaction
// d4f7fbbf92f4a3014a230b2dc70b8058d02eb36ac06b4a0736d9d60eaa9e8781. This
// spending transaction can't be duplicated because it also spends coinbase
// 0328dd85c331237f18e781d692c92de57649529bd5edf1d01036daea32ffde29. This
// coinbase has an indicated height of over 4.2 billion, and wouldn't be
// duplicatable until that height, and it's currently impossible to create a
// chain that long. Nevertheless we may wish to consider a future soft fork
// which retroactively prevents block 490,897 from creating a duplicate
// coinbase. The two historical BIP30 violations often provide a confusing
// edge case when manipulating the UTXO and it would be simpler not to have
// another edge case to deal with.
// testnet3 has no blocks before the BIP34 height with indicated heights
// post BIP34 before approximately height 486,000,000. After block
// 1,983,702 testnet3 starts doing unnecessary BIP30 checking again.
assert(pindex->pprev);
CBlockIndex* pindexBIP34height = pindex->pprev->GetAncestor(params.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() == params.GetConsensus().BIP34Hash));
// TODO: Remove BIP30 checking from block height 1,983,702 on, once we have a
// consensus change that ensures coinbases at those heights cannot
// duplicate earlier coinbases.
if (fEnforceBIP30 || pindex->nHeight >= BIP34_IMPLIES_BIP30_LIMIT) {
for (const auto& tx : block.vtx) {
for (size_t o = 0; o < tx->vout.size(); o++) {
if (view.HaveCoin(COutPoint(tx->GetHash(), o))) {
LogPrintf("ERROR: ConnectBlock(): tried to overwrite transaction\n");
return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-txns-BIP30");
}
}
}
}
// Enforce BIP68 (sequence locks)
int nLockTimeFlags = 0;
if (DeploymentActiveAt(*pindex, m_chainman, Consensus::DEPLOYMENT_CSV)) {
nLockTimeFlags |= LOCKTIME_VERIFY_SEQUENCE;
}
// Get the script flags for this block
unsigned int flags{GetBlockScriptFlags(*pindex, m_chainman)};
const auto time_2{SteadyClock::now()};
time_forks += time_2 - time_1;
LogPrint(BCLog::BENCH, " - Fork checks: %.2fms [%.2fs (%.2fms/blk)]\n",
Ticks<MillisecondsDouble>(time_2 - time_1),
Ticks<SecondsDouble>(time_forks),
Ticks<MillisecondsDouble>(time_forks) / num_blocks_total);
CBlockUndo blockundo;
// Precomputed transaction data pointers must not be invalidated
// until after `control` has run the script checks (potentially
// in multiple threads). Preallocate the vector size so a new allocation
// doesn't invalidate pointers into the vector, and keep txsdata in scope
// for as long as `control`.
CCheckQueueControl<CScriptCheck> control(fScriptChecks && parallel_script_checks ? &scriptcheckqueue : nullptr);
std::vector<PrecomputedTransactionData> txsdata(block.vtx.size());
std::vector<int> prevheights;
CAmount nFees = 0;
int nInputs = 0;
int64_t nSigOpsCost = 0;
blockundo.vtxundo.reserve(block.vtx.size() - 1);
for (unsigned int i = 0; i < block.vtx.size(); i++)
{
const CTransaction &tx = *(block.vtx[i]);
nInputs += tx.vin.size();
if (!tx.IsCoinBase())
{
CAmount txfee = 0;
TxValidationState tx_state;
if (!Consensus::CheckTxInputs(tx, tx_state, view, pindex->nHeight, txfee)) {
// Any transaction validation failure in ConnectBlock is a block consensus failure
state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
tx_state.GetRejectReason(), tx_state.GetDebugMessage());
return error("%s: Consensus::CheckTxInputs: %s, %s", __func__, tx.GetHash().ToString(), state.ToString());
}
nFees += txfee;
if (!MoneyRange(nFees)) {
LogPrintf("ERROR: %s: accumulated fee in the block out of range.\n", __func__);
return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-txns-accumulated-fee-outofrange");
}
// 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.AccessCoin(tx.vin[j].prevout).nHeight;
}
if (!SequenceLocks(tx, nLockTimeFlags, prevheights, *pindex)) {
LogPrintf("ERROR: %s: contains a non-BIP68-final transaction\n", __func__);
return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "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) {
LogPrintf("ERROR: ConnectBlock(): too many sigops\n");
return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-blk-sigops");
}
if (!tx.IsCoinBase())
{
std::vector<CScriptCheck> vChecks;
bool fCacheResults = fJustCheck; /* Don't cache results if we're actually connecting blocks (still consult the cache, though) */
TxValidationState tx_state;
if (fScriptChecks && !CheckInputScripts(tx, tx_state, view, flags, fCacheResults, fCacheResults, txsdata[i], parallel_script_checks ? &vChecks : nullptr)) {
// Any transaction validation failure in ConnectBlock is a block consensus failure
state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
tx_state.GetRejectReason(), tx_state.GetDebugMessage());
return error("ConnectBlock(): CheckInputScripts on %s failed with %s",
tx.GetHash().ToString(), state.ToString());
}
control.Add(vChecks);
}
CTxUndo undoDummy;
if (i > 0) {
blockundo.vtxundo.push_back(CTxUndo());
}
UpdateCoins(tx, view, i == 0 ? undoDummy : blockundo.vtxundo.back(), pindex->nHeight);
}
const auto time_3{SteadyClock::now()};
time_connect += time_3 - time_2;
LogPrint(BCLog::BENCH, " - Connect %u transactions: %.2fms (%.3fms/tx, %.3fms/txin) [%.2fs (%.2fms/blk)]\n", (unsigned)block.vtx.size(),
Ticks<MillisecondsDouble>(time_3 - time_2), Ticks<MillisecondsDouble>(time_3 - time_2) / block.vtx.size(),
nInputs <= 1 ? 0 : Ticks<MillisecondsDouble>(time_3 - time_2) / (nInputs - 1),
Ticks<SecondsDouble>(time_connect),
Ticks<MillisecondsDouble>(time_connect) / num_blocks_total);
CAmount blockReward = nFees + GetBlockSubsidy(pindex->nHeight, params.GetConsensus());
if (block.vtx[0]->GetValueOut() > blockReward) {
LogPrintf("ERROR: ConnectBlock(): coinbase pays too much (actual=%d vs limit=%d)\n", block.vtx[0]->GetValueOut(), blockReward);
return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-cb-amount");
}
if (!control.Wait()) {
LogPrintf("ERROR: %s: CheckQueue failed\n", __func__);
return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "block-validation-failed");
}
const auto time_4{SteadyClock::now()};
time_verify += time_4 - time_2;
LogPrint(BCLog::BENCH, " - Verify %u txins: %.2fms (%.3fms/txin) [%.2fs (%.2fms/blk)]\n", nInputs - 1,
Ticks<MillisecondsDouble>(time_4 - time_2),
nInputs <= 1 ? 0 : Ticks<MillisecondsDouble>(time_4 - time_2) / (nInputs - 1),
Ticks<SecondsDouble>(time_verify),
Ticks<MillisecondsDouble>(time_verify) / num_blocks_total);
if (fJustCheck)
return true;
if (!m_blockman.WriteUndoDataForBlock(blockundo, state, pindex, params)) {
return false;
}
const auto time_5{SteadyClock::now()};
time_undo += time_5 - time_4;
LogPrint(BCLog::BENCH, " - Write undo data: %.2fms [%.2fs (%.2fms/blk)]\n",
Ticks<MillisecondsDouble>(time_5 - time_4),
Ticks<SecondsDouble>(time_undo),
Ticks<MillisecondsDouble>(time_undo) / num_blocks_total);
if (!pindex->IsValid(BLOCK_VALID_SCRIPTS)) {
pindex->RaiseValidity(BLOCK_VALID_SCRIPTS);
m_blockman.m_dirty_blockindex.insert(pindex);
}
// add this block to the view's block chain
view.SetBestBlock(pindex->GetBlockHash());
const auto time_6{SteadyClock::now()};
time_index += time_6 - time_5;
LogPrint(BCLog::BENCH, " - Index writing: %.2fms [%.2fs (%.2fms/blk)]\n",
Ticks<MillisecondsDouble>(time_6 - time_5),
Ticks<SecondsDouble>(time_index),
Ticks<MillisecondsDouble>(time_index) / num_blocks_total);
TRACE6(validation, block_connected,
block_hash.data(),
pindex->nHeight,
block.vtx.size(),
nInputs,
nSigOpsCost,
time_5 - time_start // in microseconds (µs)
);
return true;
}
CoinsCacheSizeState Chainstate::GetCoinsCacheSizeState()
{
AssertLockHeld(::cs_main);
return this->GetCoinsCacheSizeState(
m_coinstip_cache_size_bytes,
m_mempool ? m_mempool->m_max_size_bytes : 0);
}
CoinsCacheSizeState Chainstate::GetCoinsCacheSizeState(
size_t max_coins_cache_size_bytes,
size_t max_mempool_size_bytes)
{
AssertLockHeld(::cs_main);
const int64_t nMempoolUsage = m_mempool ? m_mempool->DynamicMemoryUsage() : 0;
int64_t cacheSize = CoinsTip().DynamicMemoryUsage();
int64_t nTotalSpace =
max_coins_cache_size_bytes + std::max<int64_t>(int64_t(max_mempool_size_bytes) - nMempoolUsage, 0);
//! No need to periodic flush if at least this much space still available.
static constexpr int64_t MAX_BLOCK_COINSDB_USAGE_BYTES = 10 * 1024 * 1024; // 10MB
int64_t large_threshold =
std::max((9 * nTotalSpace) / 10, nTotalSpace - MAX_BLOCK_COINSDB_USAGE_BYTES);
if (cacheSize > nTotalSpace) {
LogPrintf("Cache size (%s) exceeds total space (%s)\n", cacheSize, nTotalSpace);
return CoinsCacheSizeState::CRITICAL;
} else if (cacheSize > large_threshold) {
return CoinsCacheSizeState::LARGE;
}
return CoinsCacheSizeState::OK;
}
bool Chainstate::FlushStateToDisk(
BlockValidationState &state,
FlushStateMode mode,
int nManualPruneHeight)
{
LOCK(cs_main);
assert(this->CanFlushToDisk());
std::set<int> setFilesToPrune;
bool full_flush_completed = false;
const size_t coins_count = CoinsTip().GetCacheSize();
const size_t coins_mem_usage = CoinsTip().DynamicMemoryUsage();
try {
{
bool fFlushForPrune = false;
bool fDoFullFlush = false;
CoinsCacheSizeState cache_state = GetCoinsCacheSizeState();
LOCK(m_blockman.cs_LastBlockFile);
if (fPruneMode && (m_blockman.m_check_for_pruning || nManualPruneHeight > 0) && !fReindex) {
// make sure we don't prune above any of the prune locks bestblocks
// pruning is height-based
int last_prune{m_chain.Height()}; // last height we can prune
std::optional<std::string> limiting_lock; // prune lock that actually was the limiting factor, only used for logging
for (const auto& prune_lock : m_blockman.m_prune_locks) {
if (prune_lock.second.height_first == std::numeric_limits<int>::max()) continue;
// Remove the buffer and one additional block here to get actual height that is outside of the buffer
const int lock_height{prune_lock.second.height_first - PRUNE_LOCK_BUFFER - 1};
last_prune = std::max(1, std::min(last_prune, lock_height));
if (last_prune == lock_height) {
limiting_lock = prune_lock.first;
}
}
if (limiting_lock) {
LogPrint(BCLog::PRUNE, "%s limited pruning to height %d\n", limiting_lock.value(), last_prune);
}
if (nManualPruneHeight > 0) {
LOG_TIME_MILLIS_WITH_CATEGORY("find files to prune (manual)", BCLog::BENCH);
m_blockman.FindFilesToPruneManual(setFilesToPrune, std::min(last_prune, nManualPruneHeight), m_chain.Height());
} else {
LOG_TIME_MILLIS_WITH_CATEGORY("find files to prune", BCLog::BENCH);
m_blockman.FindFilesToPrune(setFilesToPrune, m_chainman.GetParams().PruneAfterHeight(), m_chain.Height(), last_prune, IsInitialBlockDownload());
m_blockman.m_check_for_pruning = false;
}
if (!setFilesToPrune.empty()) {
fFlushForPrune = true;
if (!m_blockman.m_have_pruned) {
m_blockman.m_block_tree_db->WriteFlag("prunedblockfiles", true);
m_blockman.m_have_pruned = true;
}
}
}
const auto nNow = GetTime<std::chrono::microseconds>();
// Avoid writing/flushing immediately after startup.
if (m_last_write.count() == 0) {
m_last_write = nNow;
}
if (m_last_flush.count() == 0) {
m_last_flush = nNow;
}
// The cache is large and we're within 10% and 10 MiB of the limit, but we have time now (not in the middle of a block processing).
bool fCacheLarge = mode == FlushStateMode::PERIODIC && cache_state >= CoinsCacheSizeState::LARGE;
// The cache is over the limit, we have to write now.
bool fCacheCritical = mode == FlushStateMode::IF_NEEDED && cache_state >= CoinsCacheSizeState::CRITICAL;
// 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 == FlushStateMode::PERIODIC && nNow > m_last_write + DATABASE_WRITE_INTERVAL;
// It's been very long since we flushed the cache. Do this infrequently, to optimize cache usage.
bool fPeriodicFlush = mode == FlushStateMode::PERIODIC && nNow > m_last_flush + DATABASE_FLUSH_INTERVAL;
// Combine all conditions that result in a full cache flush.
fDoFullFlush = (mode == FlushStateMode::ALWAYS) || fCacheLarge || fCacheCritical || fPeriodicFlush || fFlushForPrune;
// Write blocks and block index to disk.
if (fDoFullFlush || fPeriodicWrite) {
// Ensure we can write block index
if (!CheckDiskSpace(gArgs.GetBlocksDirPath())) {
return AbortNode(state, "Disk space is too low!", _("Disk space is too low!"));
}
{
LOG_TIME_MILLIS_WITH_CATEGORY("write block and undo data to disk", BCLog::BENCH);
// First make sure all block and undo data is flushed to disk.
m_blockman.FlushBlockFile();
}
// Then update all block file information (which may refer to block and undo files).
{
LOG_TIME_MILLIS_WITH_CATEGORY("write block index to disk", BCLog::BENCH);
if (!m_blockman.WriteBlockIndexDB()) {
return AbortNode(state, "Failed to write to block index database");
}
}
// Finally remove any pruned files
if (fFlushForPrune) {
LOG_TIME_MILLIS_WITH_CATEGORY("unlink pruned files", BCLog::BENCH);
UnlinkPrunedFiles(setFilesToPrune);
}
m_last_write = nNow;
}
// Flush best chain related state. This can only be done if the blocks / block index write was also done.
if (fDoFullFlush && !CoinsTip().GetBestBlock().IsNull()) {
LOG_TIME_MILLIS_WITH_CATEGORY(strprintf("write coins cache to disk (%d coins, %.2fkB)",
coins_count, coins_mem_usage / 1000), BCLog::BENCH);
// Typical Coin structures on disk are around 48 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(gArgs.GetDataDirNet(), 48 * 2 * 2 * CoinsTip().GetCacheSize())) {
return AbortNode(state, "Disk space is too low!", _("Disk space is too low!"));
}
// Flush the chainstate (which may refer to block index entries).
if (!CoinsTip().Flush())
return AbortNode(state, "Failed to write to coin database");
m_last_flush = nNow;
full_flush_completed = true;
TRACE5(utxocache, flush,
(int64_t)(GetTimeMicros() - nNow.count()), // in microseconds (µs)
(uint32_t)mode,
(uint64_t)coins_count,
(uint64_t)coins_mem_usage,
(bool)fFlushForPrune);
}
}
if (full_flush_completed) {
// Update best block in wallet (so we can detect restored wallets).
GetMainSignals().ChainStateFlushed(m_chain.GetLocator());
}
} catch (const std::runtime_error& e) {
return AbortNode(state, std::string("System error while flushing: ") + e.what());
}
return true;
}
void Chainstate::ForceFlushStateToDisk()
{
BlockValidationState state;
if (!this->FlushStateToDisk(state, FlushStateMode::ALWAYS)) {
LogPrintf("%s: failed to flush state (%s)\n", __func__, state.ToString());
}
}
void Chainstate::PruneAndFlush()
{
BlockValidationState state;
m_blockman.m_check_for_pruning = true;
if (!this->FlushStateToDisk(state, FlushStateMode::NONE)) {
LogPrintf("%s: failed to flush state (%s)\n", __func__, state.ToString());
}
}
static void DoWarning(const bilingual_str& warning)
{
static bool fWarned = false;
SetMiscWarning(warning);
if (!fWarned) {
AlertNotify(warning.original);
fWarned = true;
}
}
/** Private helper function that concatenates warning messages. */
static void AppendWarning(bilingual_str& res, const bilingual_str& warn)
{
if (!res.empty()) res += Untranslated(", ");
res += warn;
}
static void UpdateTipLog(
const CCoinsViewCache& coins_tip,
const CBlockIndex* tip,
const CChainParams& params,
const std::string& func_name,
const std::string& prefix,
const std::string& warning_messages) EXCLUSIVE_LOCKS_REQUIRED(::cs_main)
{
AssertLockHeld(::cs_main);
LogPrintf("%s%s: new best=%s height=%d version=0x%08x log2_work=%f tx=%lu date='%s' progress=%f cache=%.1fMiB(%utxo)%s\n",
prefix, func_name,
tip->GetBlockHash().ToString(), tip->nHeight, tip->nVersion,
log(tip->nChainWork.getdouble()) / log(2.0), (unsigned long)tip->nChainTx,
FormatISO8601DateTime(tip->GetBlockTime()),
GuessVerificationProgress(params.TxData(), tip),
coins_tip.DynamicMemoryUsage() * (1.0 / (1 << 20)),
coins_tip.GetCacheSize(),
!warning_messages.empty() ? strprintf(" warning='%s'", warning_messages) : "");
}
void Chainstate::UpdateTip(const CBlockIndex* pindexNew)
{
AssertLockHeld(::cs_main);
const auto& coins_tip = this->CoinsTip();
const CChainParams& params{m_chainman.GetParams()};
// The remainder of the function isn't relevant if we are not acting on
// the active chainstate, so return if need be.
if (this != &m_chainman.ActiveChainstate()) {
// Only log every so often so that we don't bury log messages at the tip.
constexpr int BACKGROUND_LOG_INTERVAL = 2000;
if (pindexNew->nHeight % BACKGROUND_LOG_INTERVAL == 0) {
UpdateTipLog(coins_tip, pindexNew, params, __func__, "[background validation] ", "");
}
return;
}
// New best block
if (m_mempool) {
m_mempool->AddTransactionsUpdated(1);
}
{
LOCK(g_best_block_mutex);
g_best_block = pindexNew->GetBlockHash();
g_best_block_cv.notify_all();
}
bilingual_str warning_messages;
if (!this->IsInitialBlockDownload()) {
const CBlockIndex* pindex = pindexNew;
for (int bit = 0; bit < VERSIONBITS_NUM_BITS; bit++) {
WarningBitsConditionChecker checker(m_chainman, bit);
ThresholdState state = checker.GetStateFor(pindex, params.GetConsensus(), warningcache.at(bit));
if (state == ThresholdState::ACTIVE || state == ThresholdState::LOCKED_IN) {
const bilingual_str warning = strprintf(_("Unknown new rules activated (versionbit %i)"), bit);
if (state == ThresholdState::ACTIVE) {
DoWarning(warning);
} else {
AppendWarning(warning_messages, warning);
}
}
}
}
UpdateTipLog(coins_tip, pindexNew, params, __func__, "", warning_messages.original);
}
/** Disconnect m_chain's tip.
* After calling, the mempool will be in an inconsistent state, with
* transactions from disconnected blocks being added to disconnectpool. You
* should make the mempool consistent again by calling MaybeUpdateMempoolForReorg.
* with cs_main held.
*
* If disconnectpool is nullptr, then no disconnected transactions are added to
* disconnectpool (note that the caller is responsible for mempool consistency
* in any case).
*/
bool Chainstate::DisconnectTip(BlockValidationState& state, DisconnectedBlockTransactions* disconnectpool)
{
AssertLockHeld(cs_main);
if (m_mempool) AssertLockHeld(m_mempool->cs);
CBlockIndex *pindexDelete = m_chain.Tip();
assert(pindexDelete);
assert(pindexDelete->pprev);
// Read block from disk.
std::shared_ptr<CBlock> pblock = std::make_shared<CBlock>();
CBlock& block = *pblock;
if (!ReadBlockFromDisk(block, pindexDelete, m_chainman.GetConsensus())) {
return error("DisconnectTip(): Failed to read block");
}
// Apply the block atomically to the chain state.
const auto time_start{SteadyClock::now()};
{
CCoinsViewCache view(&CoinsTip());
assert(view.GetBestBlock() == pindexDelete->GetBlockHash());
if (DisconnectBlock(block, pindexDelete, view) != DISCONNECT_OK)
return error("DisconnectTip(): DisconnectBlock %s failed", pindexDelete->GetBlockHash().ToString());
bool flushed = view.Flush();
assert(flushed);
}
LogPrint(BCLog::BENCH, "- Disconnect block: %.2fms\n",
Ticks<MillisecondsDouble>(SteadyClock::now() - time_start));
{
// Prune locks that began at or after the tip should be moved backward so they get a chance to reorg
const int max_height_first{pindexDelete->nHeight - 1};
for (auto& prune_lock : m_blockman.m_prune_locks) {
if (prune_lock.second.height_first <= max_height_first) continue;
prune_lock.second.height_first = max_height_first;
LogPrint(BCLog::PRUNE, "%s prune lock moved back to %d\n", prune_lock.first, max_height_first);
}
}
// Write the chain state to disk, if necessary.
if (!FlushStateToDisk(state, FlushStateMode::IF_NEEDED)) {
return false;
}
if (disconnectpool && m_mempool) {
// Save transactions to re-add to mempool at end of reorg
for (auto it = block.vtx.rbegin(); it != block.vtx.rend(); ++it) {
disconnectpool->addTransaction(*it);
}
while (disconnectpool->DynamicMemoryUsage() > MAX_DISCONNECTED_TX_POOL_SIZE * 1000) {
// Drop the earliest entry, and remove its children from the mempool.
auto it = disconnectpool->queuedTx.get<insertion_order>().begin();
m_mempool->removeRecursive(**it, MemPoolRemovalReason::REORG);
disconnectpool->removeEntry(it);
}
}
m_chain.SetTip(*pindexDelete->pprev);
UpdateTip(pindexDelete->pprev);
// Let wallets know transactions went from 1-confirmed to
// 0-confirmed or conflicted:
GetMainSignals().BlockDisconnected(pblock, pindexDelete);
return true;
}
static SteadyClock::duration time_read_from_disk_total{};
static SteadyClock::duration time_connect_total{};
static SteadyClock::duration time_flush{};
static SteadyClock::duration time_chainstate{};
static SteadyClock::duration time_post_connect{};
struct PerBlockConnectTrace {
CBlockIndex* pindex = nullptr;
std::shared_ptr<const CBlock> pblock;
PerBlockConnectTrace() = default;
};
/**
* Used to track blocks whose transactions were applied to the UTXO state as a
* part of a single ActivateBestChainStep call.
*
* This class is single-use, once you call GetBlocksConnected() you have to throw
* it away and make a new one.
*/
class ConnectTrace {
private:
std::vector<PerBlockConnectTrace> blocksConnected;
public:
explicit ConnectTrace() : blocksConnected(1) {}
void BlockConnected(CBlockIndex* pindex, std::shared_ptr<const CBlock> pblock) {
assert(!blocksConnected.back().pindex);
assert(pindex);
assert(pblock);
blocksConnected.back().pindex = pindex;
blocksConnected.back().pblock = std::move(pblock);
blocksConnected.emplace_back();
}
std::vector<PerBlockConnectTrace>& GetBlocksConnected() {
// We always keep one extra block at the end of our list because
// blocks are added after all the conflicted transactions have
// been filled in. Thus, the last entry should always be an empty
// one waiting for the transactions from the next block. We pop
// the last entry here to make sure the list we return is sane.
assert(!blocksConnected.back().pindex);
blocksConnected.pop_back();
return blocksConnected;
}
};
/**
* Connect a new block to m_chain. pblock is either nullptr or a pointer to a CBlock
* corresponding to pindexNew, to bypass loading it again from disk.
*
* The block is added to connectTrace if connection succeeds.
*/
bool Chainstate::ConnectTip(BlockValidationState& state, CBlockIndex* pindexNew, const std::shared_ptr<const CBlock>& pblock, ConnectTrace& connectTrace, DisconnectedBlockTransactions& disconnectpool)
{
AssertLockHeld(cs_main);
if (m_mempool) AssertLockHeld(m_mempool->cs);
assert(pindexNew->pprev == m_chain.Tip());
// Read block from disk.
const auto time_1{SteadyClock::now()};
std::shared_ptr<const CBlock> pthisBlock;
if (!pblock) {
std::shared_ptr<CBlock> pblockNew = std::make_shared<CBlock>();
if (!ReadBlockFromDisk(*pblockNew, pindexNew, m_chainman.GetConsensus())) {
return AbortNode(state, "Failed to read block");
}
pthisBlock = pblockNew;
} else {
LogPrint(BCLog::BENCH, " - Using cached block\n");
pthisBlock = pblock;
}
const CBlock& blockConnecting = *pthisBlock;
// Apply the block atomically to the chain state.
const auto time_2{SteadyClock::now()};
time_read_from_disk_total += time_2 - time_1;
SteadyClock::time_point time_3;
LogPrint(BCLog::BENCH, " - Load block from disk: %.2fms [%.2fs (%.2fms/blk)]\n",
Ticks<MillisecondsDouble>(time_2 - time_1),
Ticks<SecondsDouble>(time_read_from_disk_total),
Ticks<MillisecondsDouble>(time_read_from_disk_total) / num_blocks_total);
{
CCoinsViewCache view(&CoinsTip());
bool rv = ConnectBlock(blockConnecting, state, pindexNew, view);
GetMainSignals().BlockChecked(blockConnecting, state);
if (!rv) {
if (state.IsInvalid())
InvalidBlockFound(pindexNew, state);
return error("%s: ConnectBlock %s failed, %s", __func__, pindexNew->GetBlockHash().ToString(), state.ToString());
}
time_3 = SteadyClock::now();
time_connect_total += time_3 - time_2;
assert(num_blocks_total > 0);
LogPrint(BCLog::BENCH, " - Connect total: %.2fms [%.2fs (%.2fms/blk)]\n",
Ticks<MillisecondsDouble>(time_3 - time_2),
Ticks<SecondsDouble>(time_connect_total),
Ticks<MillisecondsDouble>(time_connect_total) / num_blocks_total);
bool flushed = view.Flush();
assert(flushed);
}
const auto time_4{SteadyClock::now()};
time_flush += time_4 - time_3;
LogPrint(BCLog::BENCH, " - Flush: %.2fms [%.2fs (%.2fms/blk)]\n",
Ticks<MillisecondsDouble>(time_4 - time_3),
Ticks<SecondsDouble>(time_flush),
Ticks<MillisecondsDouble>(time_flush) / num_blocks_total);
// Write the chain state to disk, if necessary.
if (!FlushStateToDisk(state, FlushStateMode::IF_NEEDED)) {
return false;
}
const auto time_5{SteadyClock::now()};
time_chainstate += time_5 - time_4;
LogPrint(BCLog::BENCH, " - Writing chainstate: %.2fms [%.2fs (%.2fms/blk)]\n",
Ticks<MillisecondsDouble>(time_5 - time_4),
Ticks<SecondsDouble>(time_chainstate),
Ticks<MillisecondsDouble>(time_chainstate) / num_blocks_total);
// Remove conflicting transactions from the mempool.;
if (m_mempool) {
m_mempool->removeForBlock(blockConnecting.vtx, pindexNew->nHeight);
disconnectpool.removeForBlock(blockConnecting.vtx);
}
// Update m_chain & related variables.
m_chain.SetTip(*pindexNew);
UpdateTip(pindexNew);
const auto time_6{SteadyClock::now()};
time_post_connect += time_6 - time_5;
time_total += time_6 - time_1;
LogPrint(BCLog::BENCH, " - Connect postprocess: %.2fms [%.2fs (%.2fms/blk)]\n",
Ticks<MillisecondsDouble>(time_6 - time_5),
Ticks<SecondsDouble>(time_post_connect),
Ticks<MillisecondsDouble>(time_post_connect) / num_blocks_total);
LogPrint(BCLog::BENCH, "- Connect block: %.2fms [%.2fs (%.2fms/blk)]\n",
Ticks<MillisecondsDouble>(time_6 - time_1),
Ticks<SecondsDouble>(time_total),
Ticks<MillisecondsDouble>(time_total) / num_blocks_total);
connectTrace.BlockConnected(pindexNew, std::move(pthisBlock));
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).
*/
CBlockIndex* Chainstate::FindMostWorkChain()
{
AssertLockHeld(::cs_main);
do {
CBlockIndex *pindexNew = nullptr;
// Find the best candidate header.
{
std::set<CBlockIndex*, CBlockIndexWorkComparator>::reverse_iterator it = setBlockIndexCandidates.rbegin();
if (it == setBlockIndexCandidates.rend())
return nullptr;
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 && !m_chain.Contains(pindexTest)) {
assert(pindexTest->HaveTxsDownloaded() || 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 && (m_chainman.m_best_invalid == nullptr || pindexNew->nChainWork > m_chainman.m_best_invalid->nChainWork)) {
m_chainman.m_best_invalid = 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 m_blocks_unlinked,
// so that if the block arrives in the future we can try adding
// to setBlockIndexCandidates again.
m_blockman.m_blocks_unlinked.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. */
void Chainstate::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, m_chain.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 nullptr or a pointer to a CBlock corresponding to pindexMostWork.
*
* @returns true unless a system error occurred
*/
bool Chainstate::ActivateBestChainStep(BlockValidationState& state, CBlockIndex* pindexMostWork, const std::shared_ptr<const CBlock>& pblock, bool& fInvalidFound, ConnectTrace& connectTrace)
{
AssertLockHeld(cs_main);
if (m_mempool) AssertLockHeld(m_mempool->cs);
const CBlockIndex* pindexOldTip = m_chain.Tip();
const CBlockIndex* pindexFork = m_chain.FindFork(pindexMostWork);
// Disconnect active blocks which are no longer in the best chain.
bool fBlocksDisconnected = false;
DisconnectedBlockTransactions disconnectpool;
while (m_chain.Tip() && m_chain.Tip() != pindexFork) {
if (!DisconnectTip(state, &disconnectpool)) {
// This is likely a fatal error, but keep the mempool consistent,
// just in case. Only remove from the mempool in this case.
MaybeUpdateMempoolForReorg(disconnectpool, false);
// If we're unable to disconnect a block during normal operation,
// then that is a failure of our local system -- we should abort
// rather than stay on a less work chain.
AbortNode(state, "Failed to disconnect block; see debug.log for details");
return false;
}
fBlocksDisconnected = true;
}
// Build list of new blocks to connect (in descending height order).
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.
for (CBlockIndex* pindexConnect : reverse_iterate(vpindexToConnect)) {
if (!ConnectTip(state, pindexConnect, pindexConnect == pindexMostWork ? pblock : std::shared_ptr<const CBlock>(), connectTrace, disconnectpool)) {
if (state.IsInvalid()) {
// The block violates a consensus rule.
if (state.GetResult() != BlockValidationResult::BLOCK_MUTATED) {
InvalidChainFound(vpindexToConnect.front());
}
state = BlockValidationState();
fInvalidFound = true;
fContinue = false;
break;
} else {
// A system error occurred (disk space, database error, ...).
// Make the mempool consistent with the current tip, just in case
// any observers try to use it before shutdown.
MaybeUpdateMempoolForReorg(disconnectpool, false);
return false;
}
} else {
PruneBlockIndexCandidates();
if (!pindexOldTip || m_chain.Tip()->nChainWork > pindexOldTip->nChainWork) {
// We're in a better position than we were. Return temporarily to release the lock.
fContinue = false;
break;
}
}
}
}
if (fBlocksDisconnected) {
// If any blocks were disconnected, disconnectpool may be non empty. Add
// any disconnected transactions back to the mempool.
MaybeUpdateMempoolForReorg(disconnectpool, true);
}
if (m_mempool) m_mempool->check(this->CoinsTip(), this->m_chain.Height() + 1);
CheckForkWarningConditions();
return true;
}
static SynchronizationState GetSynchronizationState(bool init)
{
if (!init) return SynchronizationState::POST_INIT;
if (::fReindex) return SynchronizationState::INIT_REINDEX;
return SynchronizationState::INIT_DOWNLOAD;
}
static bool NotifyHeaderTip(Chainstate& chainstate) LOCKS_EXCLUDED(cs_main) {
bool fNotify = false;
bool fInitialBlockDownload = false;
static CBlockIndex* pindexHeaderOld = nullptr;
CBlockIndex* pindexHeader = nullptr;
{
LOCK(cs_main);
pindexHeader = chainstate.m_chainman.m_best_header;
if (pindexHeader != pindexHeaderOld) {
fNotify = true;
fInitialBlockDownload = chainstate.IsInitialBlockDownload();
pindexHeaderOld = pindexHeader;
}
}
// Send block tip changed notifications without cs_main
if (fNotify) {
uiInterface.NotifyHeaderTip(GetSynchronizationState(fInitialBlockDownload), pindexHeader->nHeight, pindexHeader->nTime, false);
}
return fNotify;
}
static void LimitValidationInterfaceQueue() LOCKS_EXCLUDED(cs_main) {
AssertLockNotHeld(cs_main);
if (GetMainSignals().CallbacksPending() > 10) {
SyncWithValidationInterfaceQueue();
}
}
bool Chainstate::ActivateBestChain(BlockValidationState& state, std::shared_ptr<const CBlock> pblock)
{
AssertLockNotHeld(m_chainstate_mutex);
// 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!
AssertLockNotHeld(::cs_main);
// ABC maintains a fair degree of expensive-to-calculate internal state
// because this function periodically releases cs_main so that it does not lock up other threads for too long
// during large connects - and to allow for e.g. the callback queue to drain
// we use m_chainstate_mutex to enforce mutual exclusion so that only one caller may execute this function at a time
LOCK(m_chainstate_mutex);
CBlockIndex *pindexMostWork = nullptr;
CBlockIndex *pindexNewTip = nullptr;
int nStopAtHeight = gArgs.GetIntArg("-stopatheight", DEFAULT_STOPATHEIGHT);
do {
// Block until the validation queue drains. This should largely
// never happen in normal operation, however may happen during
// reindex, causing memory blowup if we run too far ahead.
// Note that if a validationinterface callback ends up calling
// ActivateBestChain this may lead to a deadlock! We should
// probably have a DEBUG_LOCKORDER test for this in the future.
LimitValidationInterfaceQueue();
{
LOCK(cs_main);
// Lock transaction pool for at least as long as it takes for connectTrace to be consumed
LOCK(MempoolMutex());
CBlockIndex* starting_tip = m_chain.Tip();
bool blocks_connected = false;
do {
// We absolutely may not unlock cs_main until we've made forward progress
// (with the exception of shutdown due to hardware issues, low disk space, etc).
ConnectTrace connectTrace; // Destructed before cs_main is unlocked
if (pindexMostWork == nullptr) {
pindexMostWork = FindMostWorkChain();
}
// Whether we have anything to do at all.
if (pindexMostWork == nullptr || pindexMostWork == m_chain.Tip()) {
break;
}
bool fInvalidFound = false;
std::shared_ptr<const CBlock> nullBlockPtr;
if (!ActivateBestChainStep(state, pindexMostWork, pblock && pblock->GetHash() == pindexMostWork->GetBlockHash() ? pblock : nullBlockPtr, fInvalidFound, connectTrace)) {
// A system error occurred
return false;
}
blocks_connected = true;
if (fInvalidFound) {
// Wipe cache, we may need another branch now.
pindexMostWork = nullptr;
}
pindexNewTip = m_chain.Tip();
for (const PerBlockConnectTrace& trace : connectTrace.GetBlocksConnected()) {
assert(trace.pblock && trace.pindex);
GetMainSignals().BlockConnected(trace.pblock, trace.pindex);
}
} while (!m_chain.Tip() || (starting_tip && CBlockIndexWorkComparator()(m_chain.Tip(), starting_tip)));
if (!blocks_connected) return true;
const CBlockIndex* pindexFork = m_chain.FindFork(starting_tip);
bool fInitialDownload = IsInitialBlockDownload();
// Notify external listeners about the new tip.
// Enqueue while holding cs_main to ensure that UpdatedBlockTip is called in the order in which blocks are connected
if (pindexFork != pindexNewTip) {
// Notify ValidationInterface subscribers
GetMainSignals().UpdatedBlockTip(pindexNewTip, pindexFork, fInitialDownload);
// Always notify the UI if a new block tip was connected
uiInterface.NotifyBlockTip(GetSynchronizationState(fInitialDownload), pindexNewTip);
}
}
// When we reach this point, we switched to a new tip (stored in pindexNewTip).
if (nStopAtHeight && pindexNewTip && pindexNewTip->nHeight >= nStopAtHeight) StartShutdown();
// We check shutdown only after giving ActivateBestChainStep a chance to run once so that we
// never shutdown before connecting the genesis block during LoadChainTip(). Previously this
// caused an assert() failure during shutdown in such cases as the UTXO DB flushing checks
// that the best block hash is non-null.
if (ShutdownRequested()) break;
} while (pindexNewTip != pindexMostWork);
CheckBlockIndex();
// Write changes periodically to disk, after relay.
if (!FlushStateToDisk(state, FlushStateMode::PERIODIC)) {
return false;
}
return true;
}
bool Chainstate::PreciousBlock(BlockValidationState& state, CBlockIndex* pindex)
{
AssertLockNotHeld(m_chainstate_mutex);
AssertLockNotHeld(::cs_main);
{
LOCK(cs_main);
if (pindex->nChainWork < m_chain.Tip()->nChainWork) {
// Nothing to do, this block is not at the tip.
return true;
}
if (m_chain.Tip()->nChainWork > nLastPreciousChainwork) {
// The chain has been extended since the last call, reset the counter.
nBlockReverseSequenceId = -1;
}
nLastPreciousChainwork = m_chain.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->HaveTxsDownloaded()) {
setBlockIndexCandidates.insert(pindex);
PruneBlockIndexCandidates();
}
}
return ActivateBestChain(state, std::shared_ptr<const CBlock>());
}
bool Chainstate::InvalidateBlock(BlockValidationState& state, CBlockIndex* pindex)
{
AssertLockNotHeld(m_chainstate_mutex);
AssertLockNotHeld(::cs_main);
// Genesis block can't be invalidated
assert(pindex);
if (pindex->nHeight == 0) return false;
CBlockIndex* to_mark_failed = pindex;
bool pindex_was_in_chain = false;
int disconnected = 0;
// We do not allow ActivateBestChain() to run while InvalidateBlock() is
// running, as that could cause the tip to change while we disconnect
// blocks.
LOCK(m_chainstate_mutex);
// We'll be acquiring and releasing cs_main below, to allow the validation
// callbacks to run. However, we should keep the block index in a
// consistent state as we disconnect blocks -- in particular we need to
// add equal-work blocks to setBlockIndexCandidates as we disconnect.
// To avoid walking the block index repeatedly in search of candidates,
// build a map once so that we can look up candidate blocks by chain
// work as we go.
std::multimap<const arith_uint256, CBlockIndex *> candidate_blocks_by_work;
{
LOCK(cs_main);
for (auto& entry : m_blockman.m_block_index) {
CBlockIndex* candidate = &entry.second;
// We don't need to put anything in our active chain into the
// multimap, because those candidates will be found and considered
// as we disconnect.
// Instead, consider only non-active-chain blocks that have at
// least as much work as where we expect the new tip to end up.
if (!m_chain.Contains(candidate) &&
!CBlockIndexWorkComparator()(candidate, pindex->pprev) &&
candidate->IsValid(BLOCK_VALID_TRANSACTIONS) &&
candidate->HaveTxsDownloaded()) {
candidate_blocks_by_work.insert(std::make_pair(candidate->nChainWork, candidate));
}
}
}
// Disconnect (descendants of) pindex, and mark them invalid.
while (true) {
if (ShutdownRequested()) break;
// Make sure the queue of validation callbacks doesn't grow unboundedly.
LimitValidationInterfaceQueue();
LOCK(cs_main);
// Lock for as long as disconnectpool is in scope to make sure MaybeUpdateMempoolForReorg is
// called after DisconnectTip without unlocking in between
LOCK(MempoolMutex());
if (!m_chain.Contains(pindex)) break;
pindex_was_in_chain = true;
CBlockIndex *invalid_walk_tip = m_chain.Tip();
// ActivateBestChain considers blocks already in m_chain
// unconditionally valid already, so force disconnect away from it.
DisconnectedBlockTransactions disconnectpool;
bool ret = DisconnectTip(state, &disconnectpool);
// DisconnectTip will add transactions to disconnectpool.
// Adjust the mempool to be consistent with the new tip, adding
// transactions back to the mempool if disconnecting was successful,
// and we're not doing a very deep invalidation (in which case
// keeping the mempool up to date is probably futile anyway).
MaybeUpdateMempoolForReorg(disconnectpool, /* fAddToMempool = */ (++disconnected <= 10) && ret);
if (!ret) return false;
assert(invalid_walk_tip->pprev == m_chain.Tip());
// We immediately mark the disconnected blocks as invalid.
// This prevents a case where pruned nodes may fail to invalidateblock
// and be left unable to start as they have no tip candidates (as there
// are no blocks that meet the "have data and are not invalid per
// nStatus" criteria for inclusion in setBlockIndexCandidates).
invalid_walk_tip->nStatus |= BLOCK_FAILED_VALID;
m_blockman.m_dirty_blockindex.insert(invalid_walk_tip);
setBlockIndexCandidates.erase(invalid_walk_tip);
setBlockIndexCandidates.insert(invalid_walk_tip->pprev);
if (invalid_walk_tip->pprev == to_mark_failed && (to_mark_failed->nStatus & BLOCK_FAILED_VALID)) {
// We only want to mark the last disconnected block as BLOCK_FAILED_VALID; its children
// need to be BLOCK_FAILED_CHILD instead.
to_mark_failed->nStatus = (to_mark_failed->nStatus ^ BLOCK_FAILED_VALID) | BLOCK_FAILED_CHILD;
m_blockman.m_dirty_blockindex.insert(to_mark_failed);
}
// Add any equal or more work headers to setBlockIndexCandidates
auto candidate_it = candidate_blocks_by_work.lower_bound(invalid_walk_tip->pprev->nChainWork);
while (candidate_it != candidate_blocks_by_work.end()) {
if (!CBlockIndexWorkComparator()(candidate_it->second, invalid_walk_tip->pprev)) {
setBlockIndexCandidates.insert(candidate_it->second);
candidate_it = candidate_blocks_by_work.erase(candidate_it);
} else {
++candidate_it;
}
}
// Track the last disconnected block, so we can correct its BLOCK_FAILED_CHILD status in future
// iterations, or, if it's the last one, call InvalidChainFound on it.
to_mark_failed = invalid_walk_tip;
}
CheckBlockIndex();
{
LOCK(cs_main);
if (m_chain.Contains(to_mark_failed)) {
// If the to-be-marked invalid block is in the active chain, something is interfering and we can't proceed.
return false;
}
// Mark pindex (or the last disconnected block) as invalid, even when it never was in the main chain
to_mark_failed->nStatus |= BLOCK_FAILED_VALID;
m_blockman.m_dirty_blockindex.insert(to_mark_failed);
setBlockIndexCandidates.erase(to_mark_failed);
m_chainman.m_failed_blocks.insert(to_mark_failed);
// If any new blocks somehow arrived while we were disconnecting
// (above), then the pre-calculation of what should go into
// setBlockIndexCandidates may have missed entries. This would
// technically be an inconsistency in the block index, but if we clean
// it up here, this should be an essentially unobservable error.
// Loop back over all block index entries and add any missing entries
// to setBlockIndexCandidates.
for (auto& [_, block_index] : m_blockman.m_block_index) {
if (block_index.IsValid(BLOCK_VALID_TRANSACTIONS) && block_index.HaveTxsDownloaded() && !setBlockIndexCandidates.value_comp()(&block_index, m_chain.Tip())) {
setBlockIndexCandidates.insert(&block_index);
}
}
InvalidChainFound(to_mark_failed);
}
// Only notify about a new block tip if the active chain was modified.
if (pindex_was_in_chain) {
uiInterface.NotifyBlockTip(GetSynchronizationState(IsInitialBlockDownload()), to_mark_failed->pprev);
}
return true;
}
void Chainstate::ResetBlockFailureFlags(CBlockIndex *pindex) {
AssertLockHeld(cs_main);
int nHeight = pindex->nHeight;
// Remove the invalidity flag from this block and all its descendants.
for (auto& [_, block_index] : m_blockman.m_block_index) {
if (!block_index.IsValid() && block_index.GetAncestor(nHeight) == pindex) {
block_index.nStatus &= ~BLOCK_FAILED_MASK;
m_blockman.m_dirty_blockindex.insert(&block_index);
if (block_index.IsValid(BLOCK_VALID_TRANSACTIONS) && block_index.HaveTxsDownloaded() && setBlockIndexCandidates.value_comp()(m_chain.Tip(), &block_index)) {
setBlockIndexCandidates.insert(&block_index);
}
if (&block_index == m_chainman.m_best_invalid) {
// Reset invalid block marker if it was pointing to one of those.
m_chainman.m_best_invalid = nullptr;
}
m_chainman.m_failed_blocks.erase(&block_index);
}
}
// Remove the invalidity flag from all ancestors too.
while (pindex != nullptr) {
if (pindex->nStatus & BLOCK_FAILED_MASK) {
pindex->nStatus &= ~BLOCK_FAILED_MASK;
m_blockman.m_dirty_blockindex.insert(pindex);
m_chainman.m_failed_blocks.erase(pindex);
}
pindex = pindex->pprev;
}
}
/** Mark a block as having its data received and checked (up to BLOCK_VALID_TRANSACTIONS). */
void Chainstate::ReceivedBlockTransactions(const CBlock& block, CBlockIndex* pindexNew, const FlatFilePos& pos)
{
AssertLockHeld(cs_main);
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 (DeploymentActiveAt(*pindexNew, m_chainman, Consensus::DEPLOYMENT_SEGWIT)) {
pindexNew->nStatus |= BLOCK_OPT_WITNESS;
}
pindexNew->RaiseValidity(BLOCK_VALID_TRANSACTIONS);
m_blockman.m_dirty_blockindex.insert(pindexNew);
if (pindexNew->pprev == nullptr || pindexNew->pprev->HaveTxsDownloaded()) {
// 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;
pindex->nSequenceId = nBlockSequenceId++;
if (m_chain.Tip() == nullptr || !setBlockIndexCandidates.value_comp()(pindex, m_chain.Tip())) {
setBlockIndexCandidates.insert(pindex);
}
std::pair<std::multimap<CBlockIndex*, CBlockIndex*>::iterator, std::multimap<CBlockIndex*, CBlockIndex*>::iterator> range = m_blockman.m_blocks_unlinked.equal_range(pindex);
while (range.first != range.second) {
std::multimap<CBlockIndex*, CBlockIndex*>::iterator it = range.first;
queue.push_back(it->second);
range.first++;
m_blockman.m_blocks_unlinked.erase(it);
}
}
} else {
if (pindexNew->pprev && pindexNew->pprev->IsValid(BLOCK_VALID_TREE)) {
m_blockman.m_blocks_unlinked.insert(std::make_pair(pindexNew->pprev, pindexNew));
}
}
}
static bool CheckBlockHeader(const CBlockHeader& block, BlockValidationState& state, const Consensus::Params& consensusParams, bool fCheckPOW = true)
{
// Check proof of work matches claimed amount
if (fCheckPOW && !CheckProofOfWork(block.GetHash(), block.nBits, consensusParams))
return state.Invalid(BlockValidationResult::BLOCK_INVALID_HEADER, "high-hash", "proof of work failed");
return true;
}
bool CheckBlock(const CBlock& block, BlockValidationState& 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;
// Signet only: check block solution
if (consensusParams.signet_blocks && fCheckPOW && !CheckSignetBlockSolution(block, consensusParams)) {
return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-signet-blksig", "signet block signature validation failure");
}
// Check the merkle root.
if (fCheckMerkleRoot) {
bool mutated;
uint256 hashMerkleRoot2 = BlockMerkleRoot(block, &mutated);
if (block.hashMerkleRoot != hashMerkleRoot2)
return state.Invalid(BlockValidationResult::BLOCK_MUTATED, "bad-txnmrklroot", "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.Invalid(BlockValidationResult::BLOCK_MUTATED, "bad-txns-duplicate", "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() * WITNESS_SCALE_FACTOR > MAX_BLOCK_WEIGHT || ::GetSerializeSize(block, PROTOCOL_VERSION | SERIALIZE_TRANSACTION_NO_WITNESS) * WITNESS_SCALE_FACTOR > MAX_BLOCK_WEIGHT)
return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-blk-length", "size limits failed");
// First transaction must be coinbase, the rest must not be
if (block.vtx.empty() || !block.vtx[0]->IsCoinBase())
return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-cb-missing", "first tx is not coinbase");
for (unsigned int i = 1; i < block.vtx.size(); i++)
if (block.vtx[i]->IsCoinBase())
return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-cb-multiple", "more than one coinbase");
// Check transactions
// Must check for duplicate inputs (see CVE-2018-17144)
for (const auto& tx : block.vtx) {
TxValidationState tx_state;
if (!CheckTransaction(*tx, tx_state)) {
// CheckBlock() does context-free validation checks. The only
// possible failures are consensus failures.
assert(tx_state.GetResult() == TxValidationResult::TX_CONSENSUS);
return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, tx_state.GetRejectReason(),
strprintf("Transaction check failed (tx hash %s) %s", tx->GetHash().ToString(), tx_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.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-blk-sigops", "out-of-bounds SigOpCount");
if (fCheckPOW && fCheckMerkleRoot)
block.fChecked = true;
return true;
}
void ChainstateManager::UpdateUncommittedBlockStructures(CBlock& block, const CBlockIndex* pindexPrev) const
{
int commitpos = GetWitnessCommitmentIndex(block);
static const std::vector<unsigned char> nonce(32, 0x00);
if (commitpos != NO_WITNESS_COMMITMENT && DeploymentActiveAfter(pindexPrev, *this, Consensus::DEPLOYMENT_SEGWIT) && !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> ChainstateManager::GenerateCoinbaseCommitment(CBlock& block, const CBlockIndex* pindexPrev) const
{
std::vector<unsigned char> commitment;
int commitpos = GetWitnessCommitmentIndex(block);
std::vector<unsigned char> ret(32, 0x00);
if (commitpos == NO_WITNESS_COMMITMENT) {
uint256 witnessroot = BlockWitnessMerkleRoot(block, nullptr);
CHash256().Write(witnessroot).Write(ret).Finalize(witnessroot);
CTxOut out;
out.nValue = 0;
out.scriptPubKey.resize(MINIMUM_WITNESS_COMMITMENT);
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);
return commitment;
}
bool HasValidProofOfWork(const std::vector<CBlockHeader>& headers, const Consensus::Params& consensusParams)
{
return std::all_of(headers.cbegin(), headers.cend(),
[&](const auto& header) { return CheckProofOfWork(header.GetHash(), header.nBits, consensusParams);});
}
arith_uint256 CalculateHeadersWork(const std::vector<CBlockHeader>& headers)
{
arith_uint256 total_work{0};
for (const CBlockHeader& header : headers) {
CBlockIndex dummy(header);
total_work += GetBlockProof(dummy);
}
return total_work;
}
/** Context-dependent validity checks.
* By "context", we mean only the previous block headers, but not the UTXO
* set; UTXO-related validity checks are done in ConnectBlock().
* NOTE: This function is not currently invoked by ConnectBlock(), so we
* should consider upgrade issues if we change which consensus rules are
* enforced in this function (eg by adding a new consensus rule). See comment
* in ConnectBlock().
* Note that -reindex-chainstate skips the validation that happens here!
*/
static bool ContextualCheckBlockHeader(const CBlockHeader& block, BlockValidationState& state, BlockManager& blockman, const ChainstateManager& chainman, const CBlockIndex* pindexPrev, NodeClock::time_point now) EXCLUSIVE_LOCKS_REQUIRED(::cs_main)
{
AssertLockHeld(::cs_main);
assert(pindexPrev != nullptr);
const int nHeight = pindexPrev->nHeight + 1;
// Check proof of work
const Consensus::Params& consensusParams = chainman.GetConsensus();
if (block.nBits != GetNextWorkRequired(pindexPrev, &block, consensusParams))
return state.Invalid(BlockValidationResult::BLOCK_INVALID_HEADER, "bad-diffbits", "incorrect proof of work");
// Check against checkpoints
if (chainman.m_options.checkpoints_enabled) {
// Don't accept any forks from the main chain prior to last checkpoint.
// GetLastCheckpoint finds the last checkpoint in MapCheckpoints that's in our
// BlockIndex().
const CBlockIndex* pcheckpoint = blockman.GetLastCheckpoint(chainman.GetParams().Checkpoints());
if (pcheckpoint && nHeight < pcheckpoint->nHeight) {
LogPrintf("ERROR: %s: forked chain older than last checkpoint (height %d)\n", __func__, nHeight);
return state.Invalid(BlockValidationResult::BLOCK_CHECKPOINT, "bad-fork-prior-to-checkpoint");
}
}
// Check timestamp against prev
if (block.GetBlockTime() <= pindexPrev->GetMedianTimePast())
return state.Invalid(BlockValidationResult::BLOCK_INVALID_HEADER, "time-too-old", "block's timestamp is too early");
// Check timestamp
if (block.Time() > now + std::chrono::seconds{MAX_FUTURE_BLOCK_TIME}) {
return state.Invalid(BlockValidationResult::BLOCK_TIME_FUTURE, "time-too-new", "block timestamp too far in the future");
}
// Reject blocks with outdated version
if ((block.nVersion < 2 && DeploymentActiveAfter(pindexPrev, chainman, Consensus::DEPLOYMENT_HEIGHTINCB)) ||
(block.nVersion < 3 && DeploymentActiveAfter(pindexPrev, chainman, Consensus::DEPLOYMENT_DERSIG)) ||
(block.nVersion < 4 && DeploymentActiveAfter(pindexPrev, chainman, Consensus::DEPLOYMENT_CLTV))) {
return state.Invalid(BlockValidationResult::BLOCK_INVALID_HEADER, strprintf("bad-version(0x%08x)", block.nVersion),
strprintf("rejected nVersion=0x%08x block", block.nVersion));
}
return true;
}
/** NOTE: This function is not currently invoked by ConnectBlock(), so we
* should consider upgrade issues if we change which consensus rules are
* enforced in this function (eg by adding a new consensus rule). See comment
* in ConnectBlock().
* Note that -reindex-chainstate skips the validation that happens here!
*/
static bool ContextualCheckBlock(const CBlock& block, BlockValidationState& state, const ChainstateManager& chainman, const CBlockIndex* pindexPrev)
{
const int nHeight = pindexPrev == nullptr ? 0 : pindexPrev->nHeight + 1;
// Enforce BIP113 (Median Time Past).
bool enforce_locktime_median_time_past{false};
if (DeploymentActiveAfter(pindexPrev, chainman, Consensus::DEPLOYMENT_CSV)) {
assert(pindexPrev != nullptr);
enforce_locktime_median_time_past = true;
}
const int64_t nLockTimeCutoff{enforce_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.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-txns-nonfinal", "non-final transaction");
}
}
// Enforce rule that the coinbase starts with serialized block height
if (DeploymentActiveAfter(pindexPrev, chainman, Consensus::DEPLOYMENT_HEIGHTINCB))
{
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.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-cb-height", "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 reserved value (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 reserved value). In case there are
// multiple, the last one is used.
bool fHaveWitness = false;
if (DeploymentActiveAfter(pindexPrev, chainman, Consensus::DEPLOYMENT_SEGWIT)) {
int commitpos = GetWitnessCommitmentIndex(block);
if (commitpos != NO_WITNESS_COMMITMENT) {
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.Invalid(BlockValidationResult::BLOCK_MUTATED, "bad-witness-nonce-size", strprintf("%s : invalid witness reserved value size", __func__));
}
CHash256().Write(hashWitness).Write(block.vtx[0]->vin[0].scriptWitness.stack[0]).Finalize(hashWitness);
if (memcmp(hashWitness.begin(), &block.vtx[0]->vout[commitpos].scriptPubKey[6], 32)) {
return state.Invalid(BlockValidationResult::BLOCK_MUTATED, "bad-witness-merkle-match", 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 (const auto& tx : block.vtx) {
if (tx->HasWitness()) {
return state.Invalid(BlockValidationResult::BLOCK_MUTATED, "unexpected-witness", strprintf("%s : unexpected witness data found", __func__));
}
}
}
// After the coinbase witness reserved value 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.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-blk-weight", strprintf("%s : weight limit failed", __func__));
}
return true;
}
bool ChainstateManager::AcceptBlockHeader(const CBlockHeader& block, BlockValidationState& state, CBlockIndex** ppindex, bool min_pow_checked)
{
AssertLockHeld(cs_main);
// Check for duplicate
uint256 hash = block.GetHash();
BlockMap::iterator miSelf{m_blockman.m_block_index.find(hash)};
if (hash != GetConsensus().hashGenesisBlock) {
if (miSelf != m_blockman.m_block_index.end()) {
// Block header is already known.
CBlockIndex* pindex = &(miSelf->second);
if (ppindex)
*ppindex = pindex;
if (pindex->nStatus & BLOCK_FAILED_MASK) {
LogPrint(BCLog::VALIDATION, "%s: block %s is marked invalid\n", __func__, hash.ToString());
return state.Invalid(BlockValidationResult::BLOCK_CACHED_INVALID, "duplicate");
}
return true;
}
if (!CheckBlockHeader(block, state, GetConsensus())) {
LogPrint(BCLog::VALIDATION, "%s: Consensus::CheckBlockHeader: %s, %s\n", __func__, hash.ToString(), state.ToString());
return false;
}
// Get prev block index
CBlockIndex* pindexPrev = nullptr;
BlockMap::iterator mi{m_blockman.m_block_index.find(block.hashPrevBlock)};
if (mi == m_blockman.m_block_index.end()) {
LogPrint(BCLog::VALIDATION, "header %s has prev block not found: %s\n", hash.ToString(), block.hashPrevBlock.ToString());
return state.Invalid(BlockValidationResult::BLOCK_MISSING_PREV, "prev-blk-not-found");
}
pindexPrev = &((*mi).second);
if (pindexPrev->nStatus & BLOCK_FAILED_MASK) {
LogPrint(BCLog::VALIDATION, "header %s has prev block invalid: %s\n", hash.ToString(), block.hashPrevBlock.ToString());
return state.Invalid(BlockValidationResult::BLOCK_INVALID_PREV, "bad-prevblk");
}
if (!ContextualCheckBlockHeader(block, state, m_blockman, *this, pindexPrev, m_options.adjusted_time_callback())) {
LogPrint(BCLog::VALIDATION, "%s: Consensus::ContextualCheckBlockHeader: %s, %s\n", __func__, hash.ToString(), state.ToString());
return false;
}
/* Determine if this block descends from any block which has been found
* invalid (m_failed_blocks), then mark pindexPrev and any blocks between
* them as failed. For example:
*
* D3
* /
* B2 - C2
* / \
* A D2 - E2 - F2
* \
* B1 - C1 - D1 - E1
*
* In the case that we attempted to reorg from E1 to F2, only to find
* C2 to be invalid, we would mark D2, E2, and F2 as BLOCK_FAILED_CHILD
* but NOT D3 (it was not in any of our candidate sets at the time).
*
* In any case D3 will also be marked as BLOCK_FAILED_CHILD at restart
* in LoadBlockIndex.
*/
if (!pindexPrev->IsValid(BLOCK_VALID_SCRIPTS)) {
// The above does not mean "invalid": it checks if the previous block
// hasn't been validated up to BLOCK_VALID_SCRIPTS. This is a performance
// optimization, in the common case of adding a new block to the tip,
// we don't need to iterate over the failed blocks list.
for (const CBlockIndex* failedit : m_failed_blocks) {
if (pindexPrev->GetAncestor(failedit->nHeight) == failedit) {
assert(failedit->nStatus & BLOCK_FAILED_VALID);
CBlockIndex* invalid_walk = pindexPrev;
while (invalid_walk != failedit) {
invalid_walk->nStatus |= BLOCK_FAILED_CHILD;
m_blockman.m_dirty_blockindex.insert(invalid_walk);
invalid_walk = invalid_walk->pprev;
}
LogPrint(BCLog::VALIDATION, "header %s has prev block invalid: %s\n", hash.ToString(), block.hashPrevBlock.ToString());
return state.Invalid(BlockValidationResult::BLOCK_INVALID_PREV, "bad-prevblk");
}
}
}
}
if (!min_pow_checked) {
LogPrint(BCLog::VALIDATION, "%s: not adding new block header %s, missing anti-dos proof-of-work validation\n", __func__, hash.ToString());
return state.Invalid(BlockValidationResult::BLOCK_HEADER_LOW_WORK, "too-little-chainwork");
}
CBlockIndex* pindex{m_blockman.AddToBlockIndex(block, m_best_header)};
if (ppindex)
*ppindex = pindex;
return true;
}
// Exposed wrapper for AcceptBlockHeader
bool ChainstateManager::ProcessNewBlockHeaders(const std::vector<CBlockHeader>& headers, bool min_pow_checked, BlockValidationState& state, const CBlockIndex** ppindex)
{
AssertLockNotHeld(cs_main);
{
LOCK(cs_main);
for (const CBlockHeader& header : headers) {
CBlockIndex *pindex = nullptr; // Use a temp pindex instead of ppindex to avoid a const_cast
bool accepted{AcceptBlockHeader(header, state, &pindex, min_pow_checked)};
ActiveChainstate().CheckBlockIndex();
if (!accepted) {
return false;
}
if (ppindex) {
*ppindex = pindex;
}
}
}
if (NotifyHeaderTip(ActiveChainstate())) {
if (ActiveChainstate().IsInitialBlockDownload() && ppindex && *ppindex) {
const CBlockIndex& last_accepted{**ppindex};
const int64_t blocks_left{(GetTime() - last_accepted.GetBlockTime()) / GetConsensus().nPowTargetSpacing};
const double progress{100.0 * last_accepted.nHeight / (last_accepted.nHeight + blocks_left)};
LogPrintf("Synchronizing blockheaders, height: %d (~%.2f%%)\n", last_accepted.nHeight, progress);
}
}
return true;
}
void ChainstateManager::ReportHeadersPresync(const arith_uint256& work, int64_t height, int64_t timestamp)
{
AssertLockNotHeld(cs_main);
const auto& chainstate = ActiveChainstate();
{
LOCK(cs_main);
// Don't report headers presync progress if we already have a post-minchainwork header chain.
// This means we lose reporting for potentially legitimate, but unlikely, deep reorgs, but
// prevent attackers that spam low-work headers from filling our logs.
if (m_best_header->nChainWork >= UintToArith256(GetConsensus().nMinimumChainWork)) return;
// Rate limit headers presync updates to 4 per second, as these are not subject to DoS
// protection.
auto now = std::chrono::steady_clock::now();
if (now < m_last_presync_update + std::chrono::milliseconds{250}) return;
m_last_presync_update = now;
}
bool initial_download = chainstate.IsInitialBlockDownload();
uiInterface.NotifyHeaderTip(GetSynchronizationState(initial_download), height, timestamp, /*presync=*/true);
if (initial_download) {
const int64_t blocks_left{(GetTime() - timestamp) / GetConsensus().nPowTargetSpacing};
const double progress{100.0 * height / (height + blocks_left)};
LogPrintf("Pre-synchronizing blockheaders, height: %d (~%.2f%%)\n", height, progress);
}
}
/** Store block on disk. If dbp is non-nullptr, the file is known to already reside on disk */
bool Chainstate::AcceptBlock(const std::shared_ptr<const CBlock>& pblock, BlockValidationState& state, CBlockIndex** ppindex, bool fRequested, const FlatFilePos* dbp, bool* fNewBlock, bool min_pow_checked)
{
const CBlock& block = *pblock;
if (fNewBlock) *fNewBlock = false;
AssertLockHeld(cs_main);
CBlockIndex *pindexDummy = nullptr;
CBlockIndex *&pindex = ppindex ? *ppindex : pindexDummy;
bool accepted_header{m_chainman.AcceptBlockHeader(block, state, &pindex, min_pow_checked)};
CheckBlockIndex();
if (!accepted_header)
return false;
// Try to process all requested blocks that we don't have, but only
// process an unrequested block if it's new and has enough work to
// advance our tip, and isn't too many blocks ahead.
bool fAlreadyHave = pindex->nStatus & BLOCK_HAVE_DATA;
bool fHasMoreOrSameWork = (m_chain.Tip() ? pindex->nChainWork >= m_chain.Tip()->nChainWork : true);
// Blocks that are too out-of-order needlessly limit the effectiveness of
// pruning, because pruning will not delete block files that contain any
// blocks which are too close in height to the tip. Apply this test
// regardless of whether pruning is enabled; it should generally be safe to
// not process unrequested blocks.
bool fTooFarAhead{pindex->nHeight > m_chain.Height() + int(MIN_BLOCKS_TO_KEEP)};
// TODO: Decouple this function from the block download logic by removing fRequested
// This requires some new chain data structure to efficiently look up if a
// block is in a chain leading to a candidate for best tip, despite not
// being such a candidate itself.
// Note that this would break the getblockfrompeer RPC
// TODO: deal better with return value and error conditions for duplicate
// and unrequested blocks.
if (fAlreadyHave) return true;
if (!fRequested) { // If we didn't ask for it:
if (pindex->nTx != 0) return true; // This is a previously-processed block that was pruned
if (!fHasMoreOrSameWork) return true; // Don't process less-work chains
if (fTooFarAhead) return true; // Block height is too high
// Protect against DoS attacks from low-work chains.
// If our tip is behind, a peer could try to send us
// low-work blocks on a fake chain that we would never
// request; don't process these.
if (pindex->nChainWork < m_chainman.MinimumChainWork()) return true;
}
const CChainParams& params{m_chainman.GetParams()};
if (!CheckBlock(block, state, params.GetConsensus()) ||
!ContextualCheckBlock(block, state, m_chainman, pindex->pprev)) {
if (state.IsInvalid() && state.GetResult() != BlockValidationResult::BLOCK_MUTATED) {
pindex->nStatus |= BLOCK_FAILED_VALID;
m_blockman.m_dirty_blockindex.insert(pindex);
}
return error("%s: %s", __func__, state.ToString());
}
// Header is valid/has work, merkle tree and segwit merkle tree are good...RELAY NOW
// (but if it does not build on our best tip, let the SendMessages loop relay it)
if (!IsInitialBlockDownload() && m_chain.Tip() == pindex->pprev)
GetMainSignals().NewPoWValidBlock(pindex, pblock);
// Write block to history file
if (fNewBlock) *fNewBlock = true;
try {
FlatFilePos blockPos{m_blockman.SaveBlockToDisk(block, pindex->nHeight, m_chain, params, dbp)};
if (blockPos.IsNull()) {
state.Error(strprintf("%s: Failed to find position to write new block to disk", __func__));
return false;
}
ReceivedBlockTransactions(block, pindex, blockPos);
} catch (const std::runtime_error& e) {
return AbortNode(state, std::string("System error: ") + e.what());
}
FlushStateToDisk(state, FlushStateMode::NONE);
CheckBlockIndex();
return true;
}
bool ChainstateManager::ProcessNewBlock(const std::shared_ptr<const CBlock>& block, bool force_processing, bool min_pow_checked, bool* new_block)
{
AssertLockNotHeld(cs_main);
{
CBlockIndex *pindex = nullptr;
if (new_block) *new_block = false;
BlockValidationState state;
// CheckBlock() does not support multi-threaded block validation because CBlock::fChecked can cause data race.
// Therefore, the following critical section must include the CheckBlock() call as well.
LOCK(cs_main);
// Skipping AcceptBlock() for CheckBlock() failures means that we will never mark a block as invalid if
// CheckBlock() fails. This is protective against consensus failure if there are any unknown forms of block
// malleability that cause CheckBlock() to fail; see e.g. CVE-2012-2459 and
// https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2019-February/016697.html. Because CheckBlock() is
// not very expensive, the anti-DoS benefits of caching failure (of a definitely-invalid block) are not substantial.
bool ret = CheckBlock(*block, state, GetConsensus());
if (ret) {
// Store to disk
ret = ActiveChainstate().AcceptBlock(block, state, &pindex, force_processing, nullptr, new_block, min_pow_checked);
}
if (!ret) {
GetMainSignals().BlockChecked(*block, state);
return error("%s: AcceptBlock FAILED (%s)", __func__, state.ToString());
}
}
NotifyHeaderTip(ActiveChainstate());
BlockValidationState state; // Only used to report errors, not invalidity - ignore it
if (!ActiveChainstate().ActivateBestChain(state, block)) {
return error("%s: ActivateBestChain failed (%s)", __func__, state.ToString());
}
return true;
}
MempoolAcceptResult ChainstateManager::ProcessTransaction(const CTransactionRef& tx, bool test_accept)
{
AssertLockHeld(cs_main);
Chainstate& active_chainstate = ActiveChainstate();
if (!active_chainstate.GetMempool()) {
TxValidationState state;
state.Invalid(TxValidationResult::TX_NO_MEMPOOL, "no-mempool");
return MempoolAcceptResult::Failure(state);
}
auto result = AcceptToMemoryPool(active_chainstate, tx, GetTime(), /*bypass_limits=*/ false, test_accept);
active_chainstate.GetMempool()->check(active_chainstate.CoinsTip(), active_chainstate.m_chain.Height() + 1);
return result;
}
bool TestBlockValidity(BlockValidationState& state,
const CChainParams& chainparams,
Chainstate& chainstate,
const CBlock& block,
CBlockIndex* pindexPrev,
const std::function<NodeClock::time_point()>& adjusted_time_callback,
bool fCheckPOW,
bool fCheckMerkleRoot)
{
AssertLockHeld(cs_main);
assert(pindexPrev && pindexPrev == chainstate.m_chain.Tip());
CCoinsViewCache viewNew(&chainstate.CoinsTip());
uint256 block_hash(block.GetHash());
CBlockIndex indexDummy(block);
indexDummy.pprev = pindexPrev;
indexDummy.nHeight = pindexPrev->nHeight + 1;
indexDummy.phashBlock = &block_hash;
// NOTE: CheckBlockHeader is called by CheckBlock
if (!ContextualCheckBlockHeader(block, state, chainstate.m_blockman, chainstate.m_chainman, pindexPrev, adjusted_time_callback()))
return error("%s: Consensus::ContextualCheckBlockHeader: %s", __func__, state.ToString());
if (!CheckBlock(block, state, chainparams.GetConsensus(), fCheckPOW, fCheckMerkleRoot))
return error("%s: Consensus::CheckBlock: %s", __func__, state.ToString());
if (!ContextualCheckBlock(block, state, chainstate.m_chainman, pindexPrev))
return error("%s: Consensus::ContextualCheckBlock: %s", __func__, state.ToString());
if (!chainstate.ConnectBlock(block, state, &indexDummy, viewNew, true)) {
return false;
}
assert(state.IsValid());
return true;
}
/* This function is called from the RPC code for pruneblockchain */
void PruneBlockFilesManual(Chainstate& active_chainstate, int nManualPruneHeight)
{
BlockValidationState state;
if (!active_chainstate.FlushStateToDisk(
state, FlushStateMode::NONE, nManualPruneHeight)) {
LogPrintf("%s: failed to flush state (%s)\n", __func__, state.ToString());
}
}
void Chainstate::LoadMempool(const fs::path& load_path, FopenFn mockable_fopen_function)
{
if (!m_mempool) return;
::LoadMempool(*m_mempool, load_path, *this, mockable_fopen_function);
m_mempool->SetLoadTried(!ShutdownRequested());
}
bool Chainstate::LoadChainTip()
{
AssertLockHeld(cs_main);
const CCoinsViewCache& coins_cache = CoinsTip();
assert(!coins_cache.GetBestBlock().IsNull()); // Never called when the coins view is empty
const CBlockIndex* tip = m_chain.Tip();
if (tip && tip->GetBlockHash() == coins_cache.GetBestBlock()) {
return true;
}
// Load pointer to end of best chain
CBlockIndex* pindex = m_blockman.LookupBlockIndex(coins_cache.GetBestBlock());
if (!pindex) {
return false;
}
m_chain.SetTip(*pindex);
PruneBlockIndexCandidates();
tip = m_chain.Tip();
LogPrintf("Loaded best chain: hashBestChain=%s height=%d date=%s progress=%f\n",
tip->GetBlockHash().ToString(),
m_chain.Height(),
FormatISO8601DateTime(tip->GetBlockTime()),
GuessVerificationProgress(m_chainman.GetParams().TxData(), tip));
return true;
}
CVerifyDB::CVerifyDB()
{
uiInterface.ShowProgress(_("Verifying blocks…").translated, 0, false);
}
CVerifyDB::~CVerifyDB()
{
uiInterface.ShowProgress("", 100, false);
}
bool CVerifyDB::VerifyDB(
Chainstate& chainstate,
const Consensus::Params& consensus_params,
CCoinsView& coinsview,
int nCheckLevel, int nCheckDepth)
{
AssertLockHeld(cs_main);
if (chainstate.m_chain.Tip() == nullptr || chainstate.m_chain.Tip()->pprev == nullptr) {
return true;
}
// Verify blocks in the best chain
if (nCheckDepth <= 0 || nCheckDepth > chainstate.m_chain.Height()) {
nCheckDepth = chainstate.m_chain.Height();
}
nCheckLevel = std::max(0, std::min(4, nCheckLevel));
LogPrintf("Verifying last %i blocks at level %i\n", nCheckDepth, nCheckLevel);
CCoinsViewCache coins(&coinsview);
CBlockIndex* pindex;
CBlockIndex* pindexFailure = nullptr;
int nGoodTransactions = 0;
BlockValidationState state;
int reportDone = 0;
LogPrintf("[0%%]..."); /* Continued */
const bool is_snapshot_cs{!chainstate.m_from_snapshot_blockhash};
for (pindex = chainstate.m_chain.Tip(); pindex && pindex->pprev; pindex = pindex->pprev) {
const int percentageDone = std::max(1, std::min(99, (int)(((double)(chainstate.m_chain.Height() - pindex->nHeight)) / (double)nCheckDepth * (nCheckLevel >= 4 ? 50 : 100))));
if (reportDone < percentageDone / 10) {
// report every 10% step
LogPrintf("[%d%%]...", percentageDone); /* Continued */
reportDone = percentageDone / 10;
}
uiInterface.ShowProgress(_("Verifying blocks…").translated, percentageDone, false);
if (pindex->nHeight <= chainstate.m_chain.Height() - nCheckDepth) {
break;
}
if ((fPruneMode || is_snapshot_cs) && !(pindex->nStatus & BLOCK_HAVE_DATA)) {
// If pruning or running under an assumeutxo snapshot, only go
// back as far as we have data.
LogPrintf("VerifyDB(): block verification stopping at height %d (pruning, no data)\n", pindex->nHeight);
break;
}
CBlock block;
// check level 0: read from disk
if (!ReadBlockFromDisk(block, pindex, consensus_params)) {
return error("VerifyDB(): *** ReadBlockFromDisk failed at %d, hash=%s", pindex->nHeight, pindex->GetBlockHash().ToString());
}
// check level 1: verify block validity
if (nCheckLevel >= 1 && !CheckBlock(block, state, consensus_params)) {
return error("%s: *** found bad block at %d, hash=%s (%s)\n", __func__,
pindex->nHeight, pindex->GetBlockHash().ToString(), state.ToString());
}
// check level 2: verify undo validity
if (nCheckLevel >= 2 && pindex) {
CBlockUndo undo;
if (!pindex->GetUndoPos().IsNull()) {
if (!UndoReadFromDisk(undo, pindex)) {
return error("VerifyDB(): *** found bad undo data at %d, hash=%s\n", pindex->nHeight, pindex->GetBlockHash().ToString());
}
}
}
// check level 3: check for inconsistencies during memory-only disconnect of tip blocks
size_t curr_coins_usage = coins.DynamicMemoryUsage() + chainstate.CoinsTip().DynamicMemoryUsage();
if (nCheckLevel >= 3 && curr_coins_usage <= chainstate.m_coinstip_cache_size_bytes) {
assert(coins.GetBestBlock() == pindex->GetBlockHash());
DisconnectResult res = chainstate.DisconnectBlock(block, pindex, coins);
if (res == DISCONNECT_FAILED) {
return error("VerifyDB(): *** irrecoverable inconsistency in block data at %d, hash=%s", pindex->nHeight, pindex->GetBlockHash().ToString());
}
if (res == DISCONNECT_UNCLEAN) {
nGoodTransactions = 0;
pindexFailure = pindex;
} else {
nGoodTransactions += block.vtx.size();
}
}
if (ShutdownRequested()) return true;
}
if (pindexFailure) {
return error("VerifyDB(): *** coin database inconsistencies found (last %i blocks, %i good transactions before that)\n", chainstate.m_chain.Height() - pindexFailure->nHeight + 1, nGoodTransactions);
}
// store block count as we move pindex at check level >= 4
int block_count = chainstate.m_chain.Height() - pindex->nHeight;
// check level 4: try reconnecting blocks
if (nCheckLevel >= 4) {
while (pindex != chainstate.m_chain.Tip()) {
const int percentageDone = std::max(1, std::min(99, 100 - (int)(((double)(chainstate.m_chain.Height() - pindex->nHeight)) / (double)nCheckDepth * 50)));
if (reportDone < percentageDone / 10) {
// report every 10% step
LogPrintf("[%d%%]...", percentageDone); /* Continued */
reportDone = percentageDone / 10;
}
uiInterface.ShowProgress(_("Verifying blocks…").translated, percentageDone, false);
pindex = chainstate.m_chain.Next(pindex);
CBlock block;
if (!ReadBlockFromDisk(block, pindex, consensus_params))
return error("VerifyDB(): *** ReadBlockFromDisk failed at %d, hash=%s", pindex->nHeight, pindex->GetBlockHash().ToString());
if (!chainstate.ConnectBlock(block, state, pindex, coins)) {
return error("VerifyDB(): *** found unconnectable block at %d, hash=%s (%s)", pindex->nHeight, pindex->GetBlockHash().ToString(), state.ToString());
}
if (ShutdownRequested()) return true;
}
}
LogPrintf("[DONE].\n");
LogPrintf("No coin database inconsistencies in last %i blocks (%i transactions)\n", block_count, nGoodTransactions);
return true;
}
/** Apply the effects of a block on the utxo cache, ignoring that it may already have been applied. */
bool Chainstate::RollforwardBlock(const CBlockIndex* pindex, CCoinsViewCache& inputs)
{
AssertLockHeld(cs_main);
// TODO: merge with ConnectBlock
CBlock block;
if (!ReadBlockFromDisk(block, pindex, m_chainman.GetConsensus())) {
return error("ReplayBlock(): ReadBlockFromDisk failed at %d, hash=%s", pindex->nHeight, pindex->GetBlockHash().ToString());
}
for (const CTransactionRef& tx : block.vtx) {
if (!tx->IsCoinBase()) {
for (const CTxIn &txin : tx->vin) {
inputs.SpendCoin(txin.prevout);
}
}
// Pass check = true as every addition may be an overwrite.
AddCoins(inputs, *tx, pindex->nHeight, true);
}
return true;
}
bool Chainstate::ReplayBlocks()
{
LOCK(cs_main);
CCoinsView& db = this->CoinsDB();
CCoinsViewCache cache(&db);
std::vector<uint256> hashHeads = db.GetHeadBlocks();
if (hashHeads.empty()) return true; // We're already in a consistent state.
if (hashHeads.size() != 2) return error("ReplayBlocks(): unknown inconsistent state");
uiInterface.ShowProgress(_("Replaying blocks…").translated, 0, false);
LogPrintf("Replaying blocks\n");
const CBlockIndex* pindexOld = nullptr; // Old tip during the interrupted flush.
const CBlockIndex* pindexNew; // New tip during the interrupted flush.
const CBlockIndex* pindexFork = nullptr; // Latest block common to both the old and the new tip.
if (m_blockman.m_block_index.count(hashHeads[0]) == 0) {
return error("ReplayBlocks(): reorganization to unknown block requested");
}
pindexNew = &(m_blockman.m_block_index[hashHeads[0]]);
if (!hashHeads[1].IsNull()) { // The old tip is allowed to be 0, indicating it's the first flush.
if (m_blockman.m_block_index.count(hashHeads[1]) == 0) {
return error("ReplayBlocks(): reorganization from unknown block requested");
}
pindexOld = &(m_blockman.m_block_index[hashHeads[1]]);
pindexFork = LastCommonAncestor(pindexOld, pindexNew);
assert(pindexFork != nullptr);
}
// Rollback along the old branch.
while (pindexOld != pindexFork) {
if (pindexOld->nHeight > 0) { // Never disconnect the genesis block.
CBlock block;
if (!ReadBlockFromDisk(block, pindexOld, m_chainman.GetConsensus())) {
return error("RollbackBlock(): ReadBlockFromDisk() failed at %d, hash=%s", pindexOld->nHeight, pindexOld->GetBlockHash().ToString());
}
LogPrintf("Rolling back %s (%i)\n", pindexOld->GetBlockHash().ToString(), pindexOld->nHeight);
DisconnectResult res = DisconnectBlock(block, pindexOld, cache);
if (res == DISCONNECT_FAILED) {
return error("RollbackBlock(): DisconnectBlock failed at %d, hash=%s", pindexOld->nHeight, pindexOld->GetBlockHash().ToString());
}
// If DISCONNECT_UNCLEAN is returned, it means a non-existing UTXO was deleted, or an existing UTXO was
// overwritten. It corresponds to cases where the block-to-be-disconnect never had all its operations
// applied to the UTXO set. However, as both writing a UTXO and deleting a UTXO are idempotent operations,
// the result is still a version of the UTXO set with the effects of that block undone.
}
pindexOld = pindexOld->pprev;
}
// Roll forward from the forking point to the new tip.
int nForkHeight = pindexFork ? pindexFork->nHeight : 0;
for (int nHeight = nForkHeight + 1; nHeight <= pindexNew->nHeight; ++nHeight) {
const CBlockIndex& pindex{*Assert(pindexNew->GetAncestor(nHeight))};
LogPrintf("Rolling forward %s (%i)\n", pindex.GetBlockHash().ToString(), nHeight);
uiInterface.ShowProgress(_("Replaying blocks…").translated, (int) ((nHeight - nForkHeight) * 100.0 / (pindexNew->nHeight - nForkHeight)) , false);
if (!RollforwardBlock(&pindex, cache)) return false;
}
cache.SetBestBlock(pindexNew->GetBlockHash());
cache.Flush();
uiInterface.ShowProgress("", 100, false);
return true;
}
bool Chainstate::NeedsRedownload() const
{
AssertLockHeld(cs_main);
// At and above m_params.SegwitHeight, segwit consensus rules must be validated
CBlockIndex* block{m_chain.Tip()};
while (block != nullptr && DeploymentActiveAt(*block, m_chainman, Consensus::DEPLOYMENT_SEGWIT)) {
if (!(block->nStatus & BLOCK_OPT_WITNESS)) {
// block is insufficiently validated for a segwit client
return true;
}
block = block->pprev;
}
return false;
}
void Chainstate::UnloadBlockIndex()
{
AssertLockHeld(::cs_main);
nBlockSequenceId = 1;
setBlockIndexCandidates.clear();
}
bool ChainstateManager::LoadBlockIndex()
{
AssertLockHeld(cs_main);
// Load block index from databases
bool needs_init = fReindex;
if (!fReindex) {
bool ret = m_blockman.LoadBlockIndexDB(GetConsensus());
if (!ret) return false;
std::vector<CBlockIndex*> vSortedByHeight{m_blockman.GetAllBlockIndices()};
std::sort(vSortedByHeight.begin(), vSortedByHeight.end(),
CBlockIndexHeightOnlyComparator());
// Find start of assumed-valid region.
int first_assumed_valid_height = std::numeric_limits<int>::max();
for (const CBlockIndex* block : vSortedByHeight) {
if (block->IsAssumedValid()) {
auto chainstates = GetAll();
// If we encounter an assumed-valid block index entry, ensure that we have
// one chainstate that tolerates assumed-valid entries and another that does
// not (i.e. the background validation chainstate), since assumed-valid
// entries should always be pending validation by a fully-validated chainstate.
auto any_chain = [&](auto fnc) { return std::any_of(chainstates.cbegin(), chainstates.cend(), fnc); };
assert(any_chain([](auto chainstate) { return chainstate->reliesOnAssumedValid(); }));
assert(any_chain([](auto chainstate) { return !chainstate->reliesOnAssumedValid(); }));
first_assumed_valid_height = block->nHeight;
break;
}
}
for (CBlockIndex* pindex : vSortedByHeight) {
if (ShutdownRequested()) return false;
if (pindex->IsAssumedValid() ||
(pindex->IsValid(BLOCK_VALID_TRANSACTIONS) &&
(pindex->HaveTxsDownloaded() || pindex->pprev == nullptr))) {
// Fill each chainstate's block candidate set. Only add assumed-valid
// blocks to the tip candidate set if the chainstate is allowed to rely on
// assumed-valid blocks.
//
// If all setBlockIndexCandidates contained the assumed-valid blocks, the
// background chainstate's ActivateBestChain() call would add assumed-valid
// blocks to the chain (based on how FindMostWorkChain() works). Obviously
// we don't want this since the purpose of the background validation chain
// is to validate assued-valid blocks.
//
// Note: This is considering all blocks whose height is greater or equal to
// the first assumed-valid block to be assumed-valid blocks, and excluding
// them from the background chainstate's setBlockIndexCandidates set. This
// does mean that some blocks which are not technically assumed-valid
// (later blocks on a fork beginning before the first assumed-valid block)
// might not get added to the background chainstate, but this is ok,
// because they will still be attached to the active chainstate if they
// actually contain more work.
//
// Instead of this height-based approach, an earlier attempt was made at
// detecting "holistically" whether the block index under consideration
// relied on an assumed-valid ancestor, but this proved to be too slow to
// be practical.
for (Chainstate* chainstate : GetAll()) {
if (chainstate->reliesOnAssumedValid() ||
pindex->nHeight < first_assumed_valid_height) {
chainstate->setBlockIndexCandidates.insert(pindex);
}
}
}
if (pindex->nStatus & BLOCK_FAILED_MASK && (!m_best_invalid || pindex->nChainWork > m_best_invalid->nChainWork)) {
m_best_invalid = pindex;
}
if (pindex->IsValid(BLOCK_VALID_TREE) && (m_best_header == nullptr || CBlockIndexWorkComparator()(m_best_header, pindex)))
m_best_header = pindex;
}
needs_init = m_blockman.m_block_index.empty();
}
if (needs_init) {
// Everything here is for *new* reindex/DBs. Thus, though
// LoadBlockIndexDB may have set fReindex if we shut down
// mid-reindex previously, we don't check fReindex and
// instead only check it prior to LoadBlockIndexDB to set
// needs_init.
LogPrintf("Initializing databases...\n");
}
return true;
}
bool Chainstate::LoadGenesisBlock()
{
LOCK(cs_main);
const CChainParams& params{m_chainman.GetParams()};
// Check whether we're already initialized by checking for genesis in
// m_blockman.m_block_index. Note that we can't use m_chain here, since it is
// set based on the coins db, not the block index db, which is the only
// thing loaded at this point.
if (m_blockman.m_block_index.count(params.GenesisBlock().GetHash()))
return true;
try {
const CBlock& block = params.GenesisBlock();
FlatFilePos blockPos{m_blockman.SaveBlockToDisk(block, 0, m_chain, params, nullptr)};
if (blockPos.IsNull()) {
return error("%s: writing genesis block to disk failed", __func__);
}
CBlockIndex* pindex = m_blockman.AddToBlockIndex(block, m_chainman.m_best_header);
ReceivedBlockTransactions(block, pindex, blockPos);
} catch (const std::runtime_error& e) {
return error("%s: failed to write genesis block: %s", __func__, e.what());
}
return true;
}
void Chainstate::LoadExternalBlockFile(
FILE* fileIn,
FlatFilePos* dbp,
std::multimap<uint256, FlatFilePos>* blocks_with_unknown_parent)
{
AssertLockNotHeld(m_chainstate_mutex);
// Either both should be specified (-reindex), or neither (-loadblock).
assert(!dbp == !blocks_with_unknown_parent);
const auto start{SteadyClock::now()};
const CChainParams& params{m_chainman.GetParams()};
int nLoaded = 0;
try {
// This takes over fileIn and calls fclose() on it in the CBufferedFile destructor
CBufferedFile blkdat(fileIn, 2*MAX_BLOCK_SERIALIZED_SIZE, MAX_BLOCK_SERIALIZED_SIZE+8, SER_DISK, CLIENT_VERSION);
// nRewind indicates where to resume scanning in case something goes wrong,
// such as a block fails to deserialize.
uint64_t nRewind = blkdat.GetPos();
while (!blkdat.eof()) {
if (ShutdownRequested()) return;
blkdat.SetPos(nRewind);
nRewind++; // start one byte further next time, in case of failure
blkdat.SetLimit(); // remove former limit
unsigned int nSize = 0;
try {
// locate a header
unsigned char buf[CMessageHeader::MESSAGE_START_SIZE];
blkdat.FindByte(params.MessageStart()[0]);
nRewind = blkdat.GetPos() + 1;
blkdat >> buf;
if (memcmp(buf, params.MessageStart(), CMessageHeader::MESSAGE_START_SIZE)) {
continue;
}
// read size
blkdat >> nSize;
if (nSize < 80 || nSize > MAX_BLOCK_SERIALIZED_SIZE)
continue;
} catch (const std::exception&) {
// no valid block header found; don't complain
// (this happens at the end of every blk.dat file)
break;
}
try {
// read block header
const uint64_t nBlockPos{blkdat.GetPos()};
if (dbp)
dbp->nPos = nBlockPos;
blkdat.SetLimit(nBlockPos + nSize);
CBlockHeader header;
blkdat >> header;
const uint256 hash{header.GetHash()};
// Skip the rest of this block (this may read from disk into memory); position to the marker before the
// next block, but it's still possible to rewind to the start of the current block (without a disk read).
nRewind = nBlockPos + nSize;
blkdat.SkipTo(nRewind);
{
LOCK(cs_main);
// detect out of order blocks, and store them for later
if (hash != params.GetConsensus().hashGenesisBlock && !m_blockman.LookupBlockIndex(header.hashPrevBlock)) {
LogPrint(BCLog::REINDEX, "%s: Out of order block %s, parent %s not known\n", __func__, hash.ToString(),
header.hashPrevBlock.ToString());
if (dbp && blocks_with_unknown_parent) {
blocks_with_unknown_parent->emplace(header.hashPrevBlock, *dbp);
}
continue;
}
// process in case the block isn't known yet
const CBlockIndex* pindex = m_blockman.LookupBlockIndex(hash);
if (!pindex || (pindex->nStatus & BLOCK_HAVE_DATA) == 0) {
// This block can be processed immediately; rewind to its start, read and deserialize it.
blkdat.SetPos(nBlockPos);
std::shared_ptr<CBlock> pblock{std::make_shared<CBlock>()};
blkdat >> *pblock;
nRewind = blkdat.GetPos();
BlockValidationState state;
if (AcceptBlock(pblock, state, nullptr, true, dbp, nullptr, true)) {
nLoaded++;
}
if (state.IsError()) {
break;
}
} else if (hash != params.GetConsensus().hashGenesisBlock && pindex->nHeight % 1000 == 0) {
LogPrint(BCLog::REINDEX, "Block Import: already had block %s at height %d\n", hash.ToString(), pindex->nHeight);
}
}
// Activate the genesis block so normal node progress can continue
if (hash == params.GetConsensus().hashGenesisBlock) {
BlockValidationState state;
if (!ActivateBestChain(state, nullptr)) {
break;
}
}
NotifyHeaderTip(*this);
if (!blocks_with_unknown_parent) continue;
// Recursively process earlier encountered successors of this block
std::deque<uint256> queue;
queue.push_back(hash);
while (!queue.empty()) {
uint256 head = queue.front();
queue.pop_front();
auto range = blocks_with_unknown_parent->equal_range(head);
while (range.first != range.second) {
std::multimap<uint256, FlatFilePos>::iterator it = range.first;
std::shared_ptr<CBlock> pblockrecursive = std::make_shared<CBlock>();
if (ReadBlockFromDisk(*pblockrecursive, it->second, params.GetConsensus())) {
LogPrint(BCLog::REINDEX, "%s: Processing out of order child %s of %s\n", __func__, pblockrecursive->GetHash().ToString(),
head.ToString());
LOCK(cs_main);
BlockValidationState dummy;
if (AcceptBlock(pblockrecursive, dummy, nullptr, true, &it->second, nullptr, true)) {
nLoaded++;
queue.push_back(pblockrecursive->GetHash());
}
}
range.first++;
blocks_with_unknown_parent->erase(it);
NotifyHeaderTip(*this);
}
}
} catch (const std::exception& e) {
// historical bugs added extra data to the block files that does not deserialize cleanly.
// commonly this data is between readable blocks, but it does not really matter. such data is not fatal to the import process.
// the code that reads the block files deals with invalid data by simply ignoring it.
// it continues to search for the next {4 byte magic message start bytes + 4 byte length + block} that does deserialize cleanly
// and passes all of the other block validation checks dealing with POW and the merkle root, etc...
// we merely note with this informational log message when unexpected data is encountered.
// we could also be experiencing a storage system read error, or a read of a previous bad write. these are possible, but
// less likely scenarios. we don't have enough information to tell a difference here.
// the reindex process is not the place to attempt to clean and/or compact the block files. if so desired, a studious node operator
// may use knowledge of the fact that the block files are not entirely pristine in order to prepare a set of pristine, and
// perhaps ordered, block files for later reindexing.
LogPrint(BCLog::REINDEX, "%s: unexpected data at file offset 0x%x - %s. continuing\n", __func__, (nRewind - 1), e.what());
}
}
} catch (const std::runtime_error& e) {
AbortNode(std::string("System error: ") + e.what());
}
LogPrintf("Loaded %i blocks from external file in %dms\n", nLoaded, Ticks<std::chrono::milliseconds>(SteadyClock::now() - start));
}
void Chainstate::CheckBlockIndex()
{
if (!m_chainman.ShouldCheckBlockIndex()) {
return;
}
LOCK(cs_main);
// During a reindex, we read the genesis block and call CheckBlockIndex before ActivateBestChain,
// so we have the genesis block in m_blockman.m_block_index but no active chain. (A few of the
// tests when iterating the block tree require that m_chain has been initialized.)
if (m_chain.Height() < 0) {
assert(m_blockman.m_block_index.size() <= 1);
return;
}
// Build forward-pointing map of the entire block tree.
std::multimap<CBlockIndex*,CBlockIndex*> forward;
for (auto& [_, block_index] : m_blockman.m_block_index) {
forward.emplace(block_index.pprev, &block_index);
}
assert(forward.size() == m_blockman.m_block_index.size());
std::pair<std::multimap<CBlockIndex*,CBlockIndex*>::iterator,std::multimap<CBlockIndex*,CBlockIndex*>::iterator> rangeGenesis = forward.equal_range(nullptr);
CBlockIndex *pindex = rangeGenesis.first->second;
rangeGenesis.first++;
assert(rangeGenesis.first == rangeGenesis.second); // There is only one index entry with parent nullptr.
// Iterate over the entire block tree, using depth-first search.
// Along the way, remember whether there are blocks on the path from genesis
// block being explored which are the first to have certain properties.
size_t nNodes = 0;
int nHeight = 0;
CBlockIndex* pindexFirstInvalid = nullptr; // Oldest ancestor of pindex which is invalid.
CBlockIndex* pindexFirstMissing = nullptr; // Oldest ancestor of pindex which does not have BLOCK_HAVE_DATA.
CBlockIndex* pindexFirstNeverProcessed = nullptr; // Oldest ancestor of pindex for which nTx == 0.
CBlockIndex* pindexFirstNotTreeValid = nullptr; // Oldest ancestor of pindex which does not have BLOCK_VALID_TREE (regardless of being valid or not).
CBlockIndex* pindexFirstNotTransactionsValid = nullptr; // Oldest ancestor of pindex which does not have BLOCK_VALID_TRANSACTIONS (regardless of being valid or not).
CBlockIndex* pindexFirstNotChainValid = nullptr; // Oldest ancestor of pindex which does not have BLOCK_VALID_CHAIN (regardless of being valid or not).
CBlockIndex* pindexFirstNotScriptsValid = nullptr; // Oldest ancestor of pindex which does not have BLOCK_VALID_SCRIPTS (regardless of being valid or not).
while (pindex != nullptr) {
nNodes++;
if (pindexFirstInvalid == nullptr && pindex->nStatus & BLOCK_FAILED_VALID) pindexFirstInvalid = pindex;
// Assumed-valid index entries will not have data since we haven't downloaded the
// full block yet.
if (pindexFirstMissing == nullptr && !(pindex->nStatus & BLOCK_HAVE_DATA) && !pindex->IsAssumedValid()) {
pindexFirstMissing = pindex;
}
if (pindexFirstNeverProcessed == nullptr && pindex->nTx == 0) pindexFirstNeverProcessed = pindex;
if (pindex->pprev != nullptr && pindexFirstNotTreeValid == nullptr && (pindex->nStatus & BLOCK_VALID_MASK) < BLOCK_VALID_TREE) pindexFirstNotTreeValid = pindex;
if (pindex->pprev != nullptr && !pindex->IsAssumedValid()) {
// Skip validity flag checks for BLOCK_ASSUMED_VALID index entries, since these
// *_VALID_MASK flags will not be present for index entries we are temporarily assuming
// valid.
if (pindexFirstNotTransactionsValid == nullptr &&
(pindex->nStatus & BLOCK_VALID_MASK) < BLOCK_VALID_TRANSACTIONS) {
pindexFirstNotTransactionsValid = pindex;
}
if (pindexFirstNotChainValid == nullptr &&
(pindex->nStatus & BLOCK_VALID_MASK) < BLOCK_VALID_CHAIN) {
pindexFirstNotChainValid = pindex;
}
if (pindexFirstNotScriptsValid == nullptr &&
(pindex->nStatus & BLOCK_VALID_MASK) < BLOCK_VALID_SCRIPTS) {
pindexFirstNotScriptsValid = pindex;
}
}
// Begin: actual consistency checks.
if (pindex->pprev == nullptr) {
// Genesis block checks.
assert(pindex->GetBlockHash() == m_chainman.GetConsensus().hashGenesisBlock); // Genesis block's hash must match.
assert(pindex == m_chain.Genesis()); // The current active chain's genesis block must be this block.
}
if (!pindex->HaveTxsDownloaded()) assert(pindex->nSequenceId <= 0); // nSequenceId can't be set positive for blocks that aren't linked (negative is used for preciousblock)
// VALID_TRANSACTIONS is equivalent to nTx > 0 for all nodes (whether or not pruning has occurred).
// HAVE_DATA is only equivalent to nTx > 0 (or VALID_TRANSACTIONS) if no pruning has occurred.
// Unless these indexes are assumed valid and pending block download on a
// background chainstate.
if (!m_blockman.m_have_pruned && !pindex->IsAssumedValid()) {
// If we've never pruned, then HAVE_DATA should be equivalent to nTx > 0
assert(!(pindex->nStatus & BLOCK_HAVE_DATA) == (pindex->nTx == 0));
assert(pindexFirstMissing == pindexFirstNeverProcessed);
} else {
// If we have pruned, then we can only say that HAVE_DATA implies nTx > 0
if (pindex->nStatus & BLOCK_HAVE_DATA) assert(pindex->nTx > 0);
}
if (pindex->nStatus & BLOCK_HAVE_UNDO) assert(pindex->nStatus & BLOCK_HAVE_DATA);
if (pindex->IsAssumedValid()) {
// Assumed-valid blocks should have some nTx value.
assert(pindex->nTx > 0);
// Assumed-valid blocks should connect to the main chain.
assert((pindex->nStatus & BLOCK_VALID_MASK) >= BLOCK_VALID_TREE);
} else {
// Otherwise there should only be an nTx value if we have
// actually seen a block's transactions.
assert(((pindex->nStatus & BLOCK_VALID_MASK) >= BLOCK_VALID_TRANSACTIONS) == (pindex->nTx > 0)); // This is pruning-independent.
}
// All parents having had data (at some point) is equivalent to all parents being VALID_TRANSACTIONS, which is equivalent to HaveTxsDownloaded().
assert((pindexFirstNeverProcessed == nullptr) == pindex->HaveTxsDownloaded());
assert((pindexFirstNotTransactionsValid == nullptr) == pindex->HaveTxsDownloaded());
assert(pindex->nHeight == nHeight); // nHeight must be consistent.
assert(pindex->pprev == nullptr || pindex->nChainWork >= pindex->pprev->nChainWork); // For every block except the genesis block, the chainwork must be larger than the parent's.
assert(nHeight < 2 || (pindex->pskip && (pindex->pskip->nHeight < nHeight))); // The pskip pointer must point back for all but the first 2 blocks.
assert(pindexFirstNotTreeValid == nullptr); // All m_blockman.m_block_index entries must at least be TREE valid
if ((pindex->nStatus & BLOCK_VALID_MASK) >= BLOCK_VALID_TREE) assert(pindexFirstNotTreeValid == nullptr); // TREE valid implies all parents are TREE valid
if ((pindex->nStatus & BLOCK_VALID_MASK) >= BLOCK_VALID_CHAIN) assert(pindexFirstNotChainValid == nullptr); // CHAIN valid implies all parents are CHAIN valid
if ((pindex->nStatus & BLOCK_VALID_MASK) >= BLOCK_VALID_SCRIPTS) assert(pindexFirstNotScriptsValid == nullptr); // SCRIPTS valid implies all parents are SCRIPTS valid
if (pindexFirstInvalid == nullptr) {
// Checks for not-invalid blocks.
assert((pindex->nStatus & BLOCK_FAILED_MASK) == 0); // The failed mask cannot be set for blocks without invalid parents.
}
if (!CBlockIndexWorkComparator()(pindex, m_chain.Tip()) && pindexFirstNeverProcessed == nullptr) {
if (pindexFirstInvalid == nullptr) {
const bool is_active = this == &m_chainman.ActiveChainstate();
// If this block sorts at least as good as the current tip and
// is valid and we have all data for its parents, it must be in
// setBlockIndexCandidates. m_chain.Tip() must also be there
// even if some data has been pruned.
//
// Don't perform this check for the background chainstate since
// its setBlockIndexCandidates shouldn't have some entries (i.e. those past the
// snapshot block) which do exist in the block index for the active chainstate.
if (is_active && (pindexFirstMissing == nullptr || pindex == m_chain.Tip())) {
assert(setBlockIndexCandidates.count(pindex));
}
// If some parent is missing, then it could be that this block was in
// setBlockIndexCandidates but had to be removed because of the missing data.
// In this case it must be in m_blocks_unlinked -- see test below.
}
} else { // If this block sorts worse than the current tip or some ancestor's block has never been seen, it cannot be in setBlockIndexCandidates.
assert(setBlockIndexCandidates.count(pindex) == 0);
}
// Check whether this block is in m_blocks_unlinked.
std::pair<std::multimap<CBlockIndex*,CBlockIndex*>::iterator,std::multimap<CBlockIndex*,CBlockIndex*>::iterator> rangeUnlinked = m_blockman.m_blocks_unlinked.equal_range(pindex->pprev);
bool foundInUnlinked = false;
while (rangeUnlinked.first != rangeUnlinked.second) {
assert(rangeUnlinked.first->first == pindex->pprev);
if (rangeUnlinked.first->second == pindex) {
foundInUnlinked = true;
break;
}
rangeUnlinked.first++;
}
if (pindex->pprev && (pindex->nStatus & BLOCK_HAVE_DATA) && pindexFirstNeverProcessed != nullptr && pindexFirstInvalid == nullptr) {
// If this block has block data available, some parent was never received, and has no invalid parents, it must be in m_blocks_unlinked.
assert(foundInUnlinked);
}
if (!(pindex->nStatus & BLOCK_HAVE_DATA)) assert(!foundInUnlinked); // Can't be in m_blocks_unlinked if we don't HAVE_DATA
if (pindexFirstMissing == nullptr) assert(!foundInUnlinked); // We aren't missing data for any parent -- cannot be in m_blocks_unlinked.
if (pindex->pprev && (pindex->nStatus & BLOCK_HAVE_DATA) && pindexFirstNeverProcessed == nullptr && pindexFirstMissing != nullptr) {
// We HAVE_DATA for this block, have received data for all parents at some point, but we're currently missing data for some parent.
assert(m_blockman.m_have_pruned); // We must have pruned.
// This block may have entered m_blocks_unlinked if:
// - it has a descendant that at some point had more work than the
// tip, and
// - we tried switching to that descendant but were missing
// data for some intermediate block between m_chain and the
// tip.
// So if this block is itself better than m_chain.Tip() and it wasn't in
// setBlockIndexCandidates, then it must be in m_blocks_unlinked.
if (!CBlockIndexWorkComparator()(pindex, m_chain.Tip()) && setBlockIndexCandidates.count(pindex) == 0) {
if (pindexFirstInvalid == nullptr) {
assert(foundInUnlinked);
}
}
}
// assert(pindex->GetBlockHash() == pindex->GetBlockHeader().GetHash()); // Perhaps too slow
// End: actual consistency checks.
// Try descending into the first subnode.
std::pair<std::multimap<CBlockIndex*,CBlockIndex*>::iterator,std::multimap<CBlockIndex*,CBlockIndex*>::iterator> range = forward.equal_range(pindex);
if (range.first != range.second) {
// A subnode was found.
pindex = range.first->second;
nHeight++;
continue;
}
// This is a leaf node.
// Move upwards until we reach a node of which we have not yet visited the last child.
while (pindex) {
// We are going to either move to a parent or a sibling of pindex.
// If pindex was the first with a certain property, unset the corresponding variable.
if (pindex == pindexFirstInvalid) pindexFirstInvalid = nullptr;
if (pindex == pindexFirstMissing) pindexFirstMissing = nullptr;
if (pindex == pindexFirstNeverProcessed) pindexFirstNeverProcessed = nullptr;
if (pindex == pindexFirstNotTreeValid) pindexFirstNotTreeValid = nullptr;
if (pindex == pindexFirstNotTransactionsValid) pindexFirstNotTransactionsValid = nullptr;
if (pindex == pindexFirstNotChainValid) pindexFirstNotChainValid = nullptr;
if (pindex == pindexFirstNotScriptsValid) pindexFirstNotScriptsValid = nullptr;
// Find our parent.
CBlockIndex* pindexPar = pindex->pprev;
// Find which child we just visited.
std::pair<std::multimap<CBlockIndex*,CBlockIndex*>::iterator,std::multimap<CBlockIndex*,CBlockIndex*>::iterator> rangePar = forward.equal_range(pindexPar);
while (rangePar.first->second != pindex) {
assert(rangePar.first != rangePar.second); // Our parent must have at least the node we're coming from as child.
rangePar.first++;
}
// Proceed to the next one.
rangePar.first++;
if (rangePar.first != rangePar.second) {
// Move to the sibling.
pindex = rangePar.first->second;
break;
} else {
// Move up further.
pindex = pindexPar;
nHeight--;
continue;
}
}
}
// Check that we actually traversed the entire map.
assert(nNodes == forward.size());
}
std::string Chainstate::ToString()
{
AssertLockHeld(::cs_main);
CBlockIndex* tip = m_chain.Tip();
return strprintf("Chainstate [%s] @ height %d (%s)",
m_from_snapshot_blockhash ? "snapshot" : "ibd",
tip ? tip->nHeight : -1, tip ? tip->GetBlockHash().ToString() : "null");
}
bool Chainstate::ResizeCoinsCaches(size_t coinstip_size, size_t coinsdb_size)
{
AssertLockHeld(::cs_main);
if (coinstip_size == m_coinstip_cache_size_bytes &&
coinsdb_size == m_coinsdb_cache_size_bytes) {
// Cache sizes are unchanged, no need to continue.
return true;
}
size_t old_coinstip_size = m_coinstip_cache_size_bytes;
m_coinstip_cache_size_bytes = coinstip_size;
m_coinsdb_cache_size_bytes = coinsdb_size;
CoinsDB().ResizeCache(coinsdb_size);
LogPrintf("[%s] resized coinsdb cache to %.1f MiB\n",
this->ToString(), coinsdb_size * (1.0 / 1024 / 1024));
LogPrintf("[%s] resized coinstip cache to %.1f MiB\n",
this->ToString(), coinstip_size * (1.0 / 1024 / 1024));
BlockValidationState state;
bool ret;
if (coinstip_size > old_coinstip_size) {
// Likely no need to flush if cache sizes have grown.
ret = FlushStateToDisk(state, FlushStateMode::IF_NEEDED);
} else {
// Otherwise, flush state to disk and deallocate the in-memory coins map.
ret = FlushStateToDisk(state, FlushStateMode::ALWAYS);
CoinsTip().ReallocateCache();
}
return ret;
}
//! Guess how far we are in the verification process at the given block index
//! require cs_main if pindex has not been validated yet (because nChainTx might be unset)
double GuessVerificationProgress(const ChainTxData& data, const CBlockIndex *pindex) {
if (pindex == nullptr)
return 0.0;
int64_t nNow = time(nullptr);
double fTxTotal;
if (pindex->nChainTx <= data.nTxCount) {
fTxTotal = data.nTxCount + (nNow - data.nTime) * data.dTxRate;
} else {
fTxTotal = pindex->nChainTx + (nNow - pindex->GetBlockTime()) * data.dTxRate;
}
return std::min<double>(pindex->nChainTx / fTxTotal, 1.0);
}
std::optional<uint256> ChainstateManager::SnapshotBlockhash() const
{
LOCK(::cs_main);
if (m_active_chainstate && m_active_chainstate->m_from_snapshot_blockhash) {
// If a snapshot chainstate exists, it will always be our active.
return m_active_chainstate->m_from_snapshot_blockhash;
}
return std::nullopt;
}
std::vector<Chainstate*> ChainstateManager::GetAll()
{
LOCK(::cs_main);
std::vector<Chainstate*> out;
if (!IsSnapshotValidated() && m_ibd_chainstate) {
out.push_back(m_ibd_chainstate.get());
}
if (m_snapshot_chainstate) {
out.push_back(m_snapshot_chainstate.get());
}
return out;
}
Chainstate& ChainstateManager::InitializeChainstate(CTxMemPool* mempool)
{
AssertLockHeld(::cs_main);
assert(!m_ibd_chainstate);
assert(!m_active_chainstate);
m_ibd_chainstate = std::make_unique<Chainstate>(mempool, m_blockman, *this);
m_active_chainstate = m_ibd_chainstate.get();
return *m_active_chainstate;
}
const AssumeutxoData* ExpectedAssumeutxo(
const int height, const CChainParams& chainparams)
{
const MapAssumeutxo& valid_assumeutxos_map = chainparams.Assumeutxo();
const auto assumeutxo_found = valid_assumeutxos_map.find(height);
if (assumeutxo_found != valid_assumeutxos_map.end()) {
return &assumeutxo_found->second;
}
return nullptr;
}
static bool DeleteCoinsDBFromDisk(const fs::path db_path, bool is_snapshot)
EXCLUSIVE_LOCKS_REQUIRED(::cs_main)
{
AssertLockHeld(::cs_main);
if (is_snapshot) {
fs::path base_blockhash_path = db_path / node::SNAPSHOT_BLOCKHASH_FILENAME;
if (fs::exists(base_blockhash_path)) {
bool removed = fs::remove(base_blockhash_path);
if (!removed) {
LogPrintf("[snapshot] failed to remove file %s\n",
fs::PathToString(base_blockhash_path));
}
} else {
LogPrintf("[snapshot] snapshot chainstate dir being removed lacks %s file\n",
fs::PathToString(node::SNAPSHOT_BLOCKHASH_FILENAME));
}
}
std::string path_str = fs::PathToString(db_path);
LogPrintf("Removing leveldb dir at %s\n", path_str);
// We have to destruct before this call leveldb::DB in order to release the db
// lock, otherwise `DestroyDB` will fail. See `leveldb::~DBImpl()`.
const bool destroyed = dbwrapper::DestroyDB(path_str, {}).ok();
if (!destroyed) {
LogPrintf("error: leveldb DestroyDB call failed on %s\n", path_str);
}
// Datadir should be removed from filesystem; otherwise initialization may detect
// it on subsequent statups and get confused.
//
// If the base_blockhash_path removal above fails in the case of snapshot
// chainstates, this will return false since leveldb won't remove a non-empty
// directory.
return destroyed && !fs::exists(db_path);
}
bool ChainstateManager::ActivateSnapshot(
AutoFile& coins_file,
const SnapshotMetadata& metadata,
bool in_memory)
{
uint256 base_blockhash = metadata.m_base_blockhash;
if (this->SnapshotBlockhash()) {
LogPrintf("[snapshot] can't activate a snapshot-based chainstate more than once\n");
return false;
}
int64_t current_coinsdb_cache_size{0};
int64_t current_coinstip_cache_size{0};
// Cache percentages to allocate to each chainstate.
//
// These particular percentages don't matter so much since they will only be
// relevant during snapshot activation; caches are rebalanced at the conclusion of
// this function. We want to give (essentially) all available cache capacity to the
// snapshot to aid the bulk load later in this function.
static constexpr double IBD_CACHE_PERC = 0.01;
static constexpr double SNAPSHOT_CACHE_PERC = 0.99;
{
LOCK(::cs_main);
// Resize the coins caches to ensure we're not exceeding memory limits.
//
// Allocate the majority of the cache to the incoming snapshot chainstate, since
// (optimistically) getting to its tip will be the top priority. We'll need to call
// `MaybeRebalanceCaches()` once we're done with this function to ensure
// the right allocation (including the possibility that no snapshot was activated
// and that we should restore the active chainstate caches to their original size).
//
current_coinsdb_cache_size = this->ActiveChainstate().m_coinsdb_cache_size_bytes;
current_coinstip_cache_size = this->ActiveChainstate().m_coinstip_cache_size_bytes;
// Temporarily resize the active coins cache to make room for the newly-created
// snapshot chain.
this->ActiveChainstate().ResizeCoinsCaches(
static_cast<size_t>(current_coinstip_cache_size * IBD_CACHE_PERC),
static_cast<size_t>(current_coinsdb_cache_size * IBD_CACHE_PERC));
}
auto snapshot_chainstate = WITH_LOCK(::cs_main,
return std::make_unique<Chainstate>(
/*mempool=*/nullptr, m_blockman, *this, base_blockhash));
{
LOCK(::cs_main);
snapshot_chainstate->InitCoinsDB(
static_cast<size_t>(current_coinsdb_cache_size * SNAPSHOT_CACHE_PERC),
in_memory, false, "chainstate");
snapshot_chainstate->InitCoinsCache(
static_cast<size_t>(current_coinstip_cache_size * SNAPSHOT_CACHE_PERC));
}
bool snapshot_ok = this->PopulateAndValidateSnapshot(
*snapshot_chainstate, coins_file, metadata);
// If not in-memory, persist the base blockhash for use during subsequent
// initialization.
if (!in_memory) {
LOCK(::cs_main);
if (!node::WriteSnapshotBaseBlockhash(*snapshot_chainstate)) {
snapshot_ok = false;
}
}
if (!snapshot_ok) {
LOCK(::cs_main);
this->MaybeRebalanceCaches();
// PopulateAndValidateSnapshot can return (in error) before the leveldb datadir
// has been created, so only attempt removal if we got that far.
if (auto snapshot_datadir = node::FindSnapshotChainstateDir()) {
// We have to destruct leveldb::DB in order to release the db lock, otherwise
// DestroyDB() (in DeleteCoinsDBFromDisk()) will fail. See `leveldb::~DBImpl()`.
// Destructing the chainstate (and so resetting the coinsviews object) does this.
snapshot_chainstate.reset();
bool removed = DeleteCoinsDBFromDisk(*snapshot_datadir, /*is_snapshot=*/true);
if (!removed) {
AbortNode(strprintf("Failed to remove snapshot chainstate dir (%s). "
"Manually remove it before restarting.\n", fs::PathToString(*snapshot_datadir)));
}
}
return false;
}
{
LOCK(::cs_main);
assert(!m_snapshot_chainstate);
m_snapshot_chainstate.swap(snapshot_chainstate);
const bool chaintip_loaded = m_snapshot_chainstate->LoadChainTip();
assert(chaintip_loaded);
m_active_chainstate = m_snapshot_chainstate.get();
LogPrintf("[snapshot] successfully activated snapshot %s\n", base_blockhash.ToString());
LogPrintf("[snapshot] (%.2f MB)\n",
m_snapshot_chainstate->CoinsTip().DynamicMemoryUsage() / (1000 * 1000));
this->MaybeRebalanceCaches();
}
return true;
}
static void FlushSnapshotToDisk(CCoinsViewCache& coins_cache, bool snapshot_loaded)
{
LOG_TIME_MILLIS_WITH_CATEGORY_MSG_ONCE(
strprintf("%s (%.2f MB)",
snapshot_loaded ? "saving snapshot chainstate" : "flushing coins cache",
coins_cache.DynamicMemoryUsage() / (1000 * 1000)),
BCLog::LogFlags::ALL);
coins_cache.Flush();
}
bool ChainstateManager::PopulateAndValidateSnapshot(
Chainstate& snapshot_chainstate,
AutoFile& coins_file,
const SnapshotMetadata& metadata)
{
// It's okay to release cs_main before we're done using `coins_cache` because we know
// that nothing else will be referencing the newly created snapshot_chainstate yet.
CCoinsViewCache& coins_cache = *WITH_LOCK(::cs_main, return &snapshot_chainstate.CoinsTip());
uint256 base_blockhash = metadata.m_base_blockhash;
CBlockIndex* snapshot_start_block = WITH_LOCK(::cs_main, return m_blockman.LookupBlockIndex(base_blockhash));
if (!snapshot_start_block) {
// Needed for ComputeUTXOStats and ExpectedAssumeutxo to determine the
// height and to avoid a crash when base_blockhash.IsNull()
LogPrintf("[snapshot] Did not find snapshot start blockheader %s\n",
base_blockhash.ToString());
return false;
}
int base_height = snapshot_start_block->nHeight;
auto maybe_au_data = ExpectedAssumeutxo(base_height, GetParams());
if (!maybe_au_data) {
LogPrintf("[snapshot] assumeutxo height in snapshot metadata not recognized " /* Continued */
"(%d) - refusing to load snapshot\n", base_height);
return false;
}
const AssumeutxoData& au_data = *maybe_au_data;
COutPoint outpoint;
Coin coin;
const uint64_t coins_count = metadata.m_coins_count;
uint64_t coins_left = metadata.m_coins_count;
LogPrintf("[snapshot] loading coins from snapshot %s\n", base_blockhash.ToString());
int64_t coins_processed{0};
while (coins_left > 0) {
try {
coins_file >> outpoint;
coins_file >> coin;
} catch (const std::ios_base::failure&) {
LogPrintf("[snapshot] bad snapshot format or truncated snapshot after deserializing %d coins\n",
coins_count - coins_left);
return false;
}
if (coin.nHeight > base_height ||
outpoint.n >= std::numeric_limits<decltype(outpoint.n)>::max() // Avoid integer wrap-around in coinstats.cpp:ApplyHash
) {
LogPrintf("[snapshot] bad snapshot data after deserializing %d coins\n",
coins_count - coins_left);
return false;
}
coins_cache.EmplaceCoinInternalDANGER(std::move(outpoint), std::move(coin));
--coins_left;
++coins_processed;
if (coins_processed % 1000000 == 0) {
LogPrintf("[snapshot] %d coins loaded (%.2f%%, %.2f MB)\n",
coins_processed,
static_cast<float>(coins_processed) * 100 / static_cast<float>(coins_count),
coins_cache.DynamicMemoryUsage() / (1000 * 1000));
}
// Batch write and flush (if we need to) every so often.
//
// If our average Coin size is roughly 41 bytes, checking every 120,000 coins
// means <5MB of memory imprecision.
if (coins_processed % 120000 == 0) {
if (ShutdownRequested()) {
return false;
}
const auto snapshot_cache_state = WITH_LOCK(::cs_main,
return snapshot_chainstate.GetCoinsCacheSizeState());
if (snapshot_cache_state >= CoinsCacheSizeState::CRITICAL) {
// This is a hack - we don't know what the actual best block is, but that
// doesn't matter for the purposes of flushing the cache here. We'll set this
// to its correct value (`base_blockhash`) below after the coins are loaded.
coins_cache.SetBestBlock(GetRandHash());
// No need to acquire cs_main since this chainstate isn't being used yet.
FlushSnapshotToDisk(coins_cache, /*snapshot_loaded=*/false);
}
}
}
// Important that we set this. This and the coins_cache accesses above are
// sort of a layer violation, but either we reach into the innards of
// CCoinsViewCache here or we have to invert some of the Chainstate to
// embed them in a snapshot-activation-specific CCoinsViewCache bulk load
// method.
coins_cache.SetBestBlock(base_blockhash);
bool out_of_coins{false};
try {
coins_file >> outpoint;
} catch (const std::ios_base::failure&) {
// We expect an exception since we should be out of coins.
out_of_coins = true;
}
if (!out_of_coins) {
LogPrintf("[snapshot] bad snapshot - coins left over after deserializing %d coins\n",
coins_count);
return false;
}
LogPrintf("[snapshot] loaded %d (%.2f MB) coins from snapshot %s\n",
coins_count,
coins_cache.DynamicMemoryUsage() / (1000 * 1000),
base_blockhash.ToString());
// No need to acquire cs_main since this chainstate isn't being used yet.
FlushSnapshotToDisk(coins_cache, /*snapshot_loaded=*/true);
assert(coins_cache.GetBestBlock() == base_blockhash);
auto breakpoint_fnc = [] { /* TODO insert breakpoint here? */ };
// As above, okay to immediately release cs_main here since no other context knows
// about the snapshot_chainstate.
CCoinsViewDB* snapshot_coinsdb = WITH_LOCK(::cs_main, return &snapshot_chainstate.CoinsDB());
const std::optional<CCoinsStats> maybe_stats = ComputeUTXOStats(CoinStatsHashType::HASH_SERIALIZED, snapshot_coinsdb, m_blockman, breakpoint_fnc);
if (!maybe_stats.has_value()) {
LogPrintf("[snapshot] failed to generate coins stats\n");
return false;
}
// Assert that the deserialized chainstate contents match the expected assumeutxo value.
if (AssumeutxoHash{maybe_stats->hashSerialized} != au_data.hash_serialized) {
LogPrintf("[snapshot] bad snapshot content hash: expected %s, got %s\n",
au_data.hash_serialized.ToString(), maybe_stats->hashSerialized.ToString());
return false;
}
snapshot_chainstate.m_chain.SetTip(*snapshot_start_block);
// The remainder of this function requires modifying data protected by cs_main.
LOCK(::cs_main);
// Fake various pieces of CBlockIndex state:
CBlockIndex* index = nullptr;
// Don't make any modifications to the genesis block.
// This is especially important because we don't want to erroneously
// apply BLOCK_ASSUMED_VALID to genesis, which would happen if we didn't skip
// it here (since it apparently isn't BLOCK_VALID_SCRIPTS).
constexpr int AFTER_GENESIS_START{1};
for (int i = AFTER_GENESIS_START; i <= snapshot_chainstate.m_chain.Height(); ++i) {
index = snapshot_chainstate.m_chain[i];
// Fake nTx so that LoadBlockIndex() loads assumed-valid CBlockIndex
// entries (among other things)
if (!index->nTx) {
index->nTx = 1;
}
// Fake nChainTx so that GuessVerificationProgress reports accurately
index->nChainTx = index->pprev->nChainTx + index->nTx;
// Mark unvalidated block index entries beneath the snapshot base block as assumed-valid.
if (!index->IsValid(BLOCK_VALID_SCRIPTS)) {
// This flag will be removed once the block is fully validated by a
// background chainstate.
index->nStatus |= BLOCK_ASSUMED_VALID;
}
// Fake BLOCK_OPT_WITNESS so that Chainstate::NeedsRedownload()
// won't ask to rewind the entire assumed-valid chain on startup.
if (DeploymentActiveAt(*index, *this, Consensus::DEPLOYMENT_SEGWIT)) {
index->nStatus |= BLOCK_OPT_WITNESS;
}
m_blockman.m_dirty_blockindex.insert(index);
// Changes to the block index will be flushed to disk after this call
// returns in `ActivateSnapshot()`, when `MaybeRebalanceCaches()` is
// called, since we've added a snapshot chainstate and therefore will
// have to downsize the IBD chainstate, which will result in a call to
// `FlushStateToDisk(ALWAYS)`.
}
assert(index);
index->nChainTx = au_data.nChainTx;
snapshot_chainstate.setBlockIndexCandidates.insert(snapshot_start_block);
LogPrintf("[snapshot] validated snapshot (%.2f MB)\n",
coins_cache.DynamicMemoryUsage() / (1000 * 1000));
return true;
}
Chainstate& ChainstateManager::ActiveChainstate() const
{
LOCK(::cs_main);
assert(m_active_chainstate);
return *m_active_chainstate;
}
bool ChainstateManager::IsSnapshotActive() const
{
LOCK(::cs_main);
return m_snapshot_chainstate && m_active_chainstate == m_snapshot_chainstate.get();
}
void ChainstateManager::MaybeRebalanceCaches()
{
AssertLockHeld(::cs_main);
if (m_ibd_chainstate && !m_snapshot_chainstate) {
LogPrintf("[snapshot] allocating all cache to the IBD chainstate\n");
// Allocate everything to the IBD chainstate.
m_ibd_chainstate->ResizeCoinsCaches(m_total_coinstip_cache, m_total_coinsdb_cache);
}
else if (m_snapshot_chainstate && !m_ibd_chainstate) {
LogPrintf("[snapshot] allocating all cache to the snapshot chainstate\n");
// Allocate everything to the snapshot chainstate.
m_snapshot_chainstate->ResizeCoinsCaches(m_total_coinstip_cache, m_total_coinsdb_cache);
}
else if (m_ibd_chainstate && m_snapshot_chainstate) {
// If both chainstates exist, determine who needs more cache based on IBD status.
//
// Note: shrink caches first so that we don't inadvertently overwhelm available memory.
if (m_snapshot_chainstate->IsInitialBlockDownload()) {
m_ibd_chainstate->ResizeCoinsCaches(
m_total_coinstip_cache * 0.05, m_total_coinsdb_cache * 0.05);
m_snapshot_chainstate->ResizeCoinsCaches(
m_total_coinstip_cache * 0.95, m_total_coinsdb_cache * 0.95);
} else {
m_snapshot_chainstate->ResizeCoinsCaches(
m_total_coinstip_cache * 0.05, m_total_coinsdb_cache * 0.05);
m_ibd_chainstate->ResizeCoinsCaches(
m_total_coinstip_cache * 0.95, m_total_coinsdb_cache * 0.95);
}
}
}
void ChainstateManager::ResetChainstates()
{
m_ibd_chainstate.reset();
m_snapshot_chainstate.reset();
m_active_chainstate = nullptr;
}
/**
* Apply default chain params to nullopt members.
* This helps to avoid coding errors around the accidental use of the compare
* operators that accept nullopt, thus ignoring the intended default value.
*/
static ChainstateManager::Options&& Flatten(ChainstateManager::Options&& opts)
{
if (!opts.check_block_index.has_value()) opts.check_block_index = opts.chainparams.DefaultConsistencyChecks();
if (!opts.minimum_chain_work.has_value()) opts.minimum_chain_work = UintToArith256(opts.chainparams.GetConsensus().nMinimumChainWork);
if (!opts.assumed_valid_block.has_value()) opts.assumed_valid_block = opts.chainparams.GetConsensus().defaultAssumeValid;
Assert(opts.adjusted_time_callback);
return std::move(opts);
}
ChainstateManager::ChainstateManager(Options options) : m_options{Flatten(std::move(options))} {}
ChainstateManager::~ChainstateManager()
{
LOCK(::cs_main);
m_versionbitscache.Clear();
// TODO: The warning cache should probably become non-global
for (auto& i : warningcache) {
i.clear();
}
}
bool ChainstateManager::DetectSnapshotChainstate(CTxMemPool* mempool)
{
assert(!m_snapshot_chainstate);
std::optional<fs::path> path = node::FindSnapshotChainstateDir();
if (!path) {
return false;
}
std::optional<uint256> base_blockhash = node::ReadSnapshotBaseBlockhash(*path);
if (!base_blockhash) {
return false;
}
LogPrintf("[snapshot] detected active snapshot chainstate (%s) - loading\n",
fs::PathToString(*path));
this->ActivateExistingSnapshot(mempool, *base_blockhash);
return true;
}
Chainstate& ChainstateManager::ActivateExistingSnapshot(CTxMemPool* mempool, uint256 base_blockhash)
{
assert(!m_snapshot_chainstate);
m_snapshot_chainstate =
std::make_unique<Chainstate>(mempool, m_blockman, *this, base_blockhash);
LogPrintf("[snapshot] switching active chainstate to %s\n", m_snapshot_chainstate->ToString());
m_active_chainstate = m_snapshot_chainstate.get();
return *m_snapshot_chainstate;
}
bool IsBIP30Repeat(const CBlockIndex& block_index)
{
return (block_index.nHeight==91842 && block_index.GetBlockHash() == uint256S("0x00000000000a4d0a398161ffc163c503763b1f4360639393e0e4c8e300e0caec")) ||
(block_index.nHeight==91880 && block_index.GetBlockHash() == uint256S("0x00000000000743f190a18c5577a3c2d2a1f610ae9601ac046a38084ccb7cd721"));
}
bool IsBIP30Unspendable(const CBlockIndex& block_index)
{
return (block_index.nHeight==91722 && block_index.GetBlockHash() == uint256S("0x00000000000271a2dc26e7667f8419f2e15416dc6955e5a6c6cdf3f2574dd08e")) ||
(block_index.nHeight==91812 && block_index.GetBlockHash() == uint256S("0x00000000000af0aed4792b1acee3d966af36cf5def14935db8de83d6f9306f2f"));
}
View Git Blame Copy Permalink