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// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2014 The Bitcoin developers
// Distributed under the MIT/X11 software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#include "main.h"
#include "addrman.h"
#include "alert.h"
#include "chainparams.h"
#include "checkpoints.h"
#include "checkqueue.h"
#include "init.h"
#include "net.h"
#include "pow.h"
#include "txdb.h"
#include "txmempool.h"
#include "ui_interface.h"
#include "util.h"
#include "utilmoneystr.h"
#include <sstream>
#include <boost/algorithm/string/replace.hpp>
#include <boost/filesystem.hpp>
#include <boost/filesystem/fstream.hpp>
#include <boost/thread.hpp>
using namespace std;
using namespace boost;
#if defined(NDEBUG)
# error "Bitcoin cannot be compiled without assertions."
#endif
//
// Global state
//
CCriticalSection cs_main;
BlockMap mapBlockIndex;
CChain chainActive;
int64_t nTimeBestReceived = 0;
CWaitableCriticalSection csBestBlock;
CConditionVariable cvBlockChange;
int nScriptCheckThreads = 0;
bool fImporting = false;
bool fReindex = false;
bool fTxIndex = false;
bool fIsBareMultisigStd = true;
unsigned int nCoinCacheSize = 5000;
/** Fees smaller than this (in satoshi) are considered zero fee (for relaying and mining) */
CFeeRate minRelayTxFee = CFeeRate(1000);
CTxMemPool mempool(::minRelayTxFee);
struct COrphanBlock {
uint256 hashBlock;
uint256 hashPrev;
vector<unsigned char> vchBlock;
};
map<uint256, COrphanBlock*> mapOrphanBlocks;
multimap<uint256, COrphanBlock*> mapOrphanBlocksByPrev;
struct COrphanTx {
CTransaction tx;
NodeId fromPeer;
};
map<uint256, COrphanTx> mapOrphanTransactions;
map<uint256, set<uint256> > mapOrphanTransactionsByPrev;
void EraseOrphansFor(NodeId peer);
// Constant stuff for coinbase transactions we create:
CScript COINBASE_FLAGS;
const string strMessageMagic = "Bitcoin Signed Message:\n";
// Internal stuff
namespace {
struct CBlockIndexWorkComparator
{
bool operator()(CBlockIndex *pa, CBlockIndex *pb) {
// First sort by most total work, ...
if (pa->nChainWork > pb->nChainWork) return false;
if (pa->nChainWork < pb->nChainWork) return true;
// ... then by earliest time received, ...
if (pa->nSequenceId < pb->nSequenceId) return false;
if (pa->nSequenceId > pb->nSequenceId) return true;
// Use pointer address as tie breaker (should only happen with blocks
// loaded from disk, as those all have id 0).
if (pa < pb) return false;
if (pa > pb) return true;
// Identical blocks.
return false;
}
};
CBlockIndex *pindexBestInvalid;
// The set of all CBlockIndex entries with BLOCK_VALID_TRANSACTIONS or better that are at least
// as good as our current tip. Entries may be failed, though.
set<CBlockIndex*, CBlockIndexWorkComparator> setBlockIndexValid;
CCriticalSection cs_LastBlockFile;
CBlockFileInfo infoLastBlockFile;
int nLastBlockFile = 0;
// Every received block is assigned a unique and increasing identifier, so we
// know which one to give priority in case of a fork.
CCriticalSection cs_nBlockSequenceId;
// Blocks loaded from disk are assigned id 0, so start the counter at 1.
uint32_t nBlockSequenceId = 1;
// Sources of received blocks, to be able to send them reject messages or ban
// them, if processing happens afterwards. Protected by cs_main.
map<uint256, NodeId> mapBlockSource;
// Blocks that are in flight, and that are in the queue to be downloaded.
// Protected by cs_main.
struct QueuedBlock {
uint256 hash;
int64_t nTime; // Time of "getdata" request in microseconds.
int nQueuedBefore; // Number of blocks in flight at the time of request.
};
map<uint256, pair<NodeId, list<QueuedBlock>::iterator> > mapBlocksInFlight;
map<uint256, pair<NodeId, list<uint256>::iterator> > mapBlocksToDownload;
} // anon namespace
//////////////////////////////////////////////////////////////////////////////
//
// dispatching functions
//
// These functions dispatch to one or all registered wallets
namespace {
struct CMainSignals {
// Notifies listeners of updated transaction data (transaction, and optionally the block it is found in.
boost::signals2::signal<void (const CTransaction &, const CBlock *)> SyncTransaction;
// Notifies listeners of an erased transaction (currently disabled, requires transaction replacement).
boost::signals2::signal<void (const uint256 &)> EraseTransaction;
// Notifies listeners of an updated transaction without new data (for now: a coinbase potentially becoming visible).
boost::signals2::signal<void (const uint256 &)> UpdatedTransaction;
// Notifies listeners of a new active block chain.
boost::signals2::signal<void (const CBlockLocator &)> SetBestChain;
// Notifies listeners about an inventory item being seen on the network.
boost::signals2::signal<void (const uint256 &)> Inventory;
// Tells listeners to broadcast their data.
boost::signals2::signal<void ()> Broadcast;
} g_signals;
} // anon namespace
void RegisterWallet(CWalletInterface* pwalletIn) {
g_signals.SyncTransaction.connect(boost::bind(&CWalletInterface::SyncTransaction, pwalletIn, _1, _2));
g_signals.EraseTransaction.connect(boost::bind(&CWalletInterface::EraseFromWallet, pwalletIn, _1));
g_signals.UpdatedTransaction.connect(boost::bind(&CWalletInterface::UpdatedTransaction, pwalletIn, _1));
g_signals.SetBestChain.connect(boost::bind(&CWalletInterface::SetBestChain, pwalletIn, _1));
g_signals.Inventory.connect(boost::bind(&CWalletInterface::Inventory, pwalletIn, _1));
g_signals.Broadcast.connect(boost::bind(&CWalletInterface::ResendWalletTransactions, pwalletIn));
}
void UnregisterWallet(CWalletInterface* pwalletIn) {
g_signals.Broadcast.disconnect(boost::bind(&CWalletInterface::ResendWalletTransactions, pwalletIn));
g_signals.Inventory.disconnect(boost::bind(&CWalletInterface::Inventory, pwalletIn, _1));
g_signals.SetBestChain.disconnect(boost::bind(&CWalletInterface::SetBestChain, pwalletIn, _1));
g_signals.UpdatedTransaction.disconnect(boost::bind(&CWalletInterface::UpdatedTransaction, pwalletIn, _1));
g_signals.EraseTransaction.disconnect(boost::bind(&CWalletInterface::EraseFromWallet, pwalletIn, _1));
g_signals.SyncTransaction.disconnect(boost::bind(&CWalletInterface::SyncTransaction, pwalletIn, _1, _2));
}
void UnregisterAllWallets() {
g_signals.Broadcast.disconnect_all_slots();
g_signals.Inventory.disconnect_all_slots();
g_signals.SetBestChain.disconnect_all_slots();
g_signals.UpdatedTransaction.disconnect_all_slots();
g_signals.EraseTransaction.disconnect_all_slots();
g_signals.SyncTransaction.disconnect_all_slots();
}
void SyncWithWallets(const CTransaction &tx, const CBlock *pblock) {
g_signals.SyncTransaction(tx, pblock);
}
//////////////////////////////////////////////////////////////////////////////
//
// Registration of network node signals.
//
namespace {
struct CBlockReject {
unsigned char chRejectCode;
string strRejectReason;
uint256 hashBlock;
};
// Maintain validation-specific state about nodes, protected by cs_main, instead
// by CNode's own locks. This simplifies asynchronous operation, where
// processing of incoming data is done after the ProcessMessage call returns,
// and we're no longer holding the node's locks.
struct CNodeState {
// Accumulated misbehaviour score for this peer.
int nMisbehavior;
// Whether this peer should be disconnected and banned (unless whitelisted).
bool fShouldBan;
// String name of this peer (debugging/logging purposes).
std::string name;
// List of asynchronously-determined block rejections to notify this peer about.
std::vector<CBlockReject> rejects;
// The best known block we know this peer has announced.
CBlockIndex *pindexBestKnownBlock;
// The hash of the last unknown block this peer has announced.
uint256 hashLastUnknownBlock;
list<QueuedBlock> vBlocksInFlight;
int nBlocksInFlight;
list<uint256> vBlocksToDownload;
int nBlocksToDownload;
int64_t nLastBlockReceive;
int64_t nLastBlockProcess;
CNodeState() {
nMisbehavior = 0;
fShouldBan = false;
pindexBestKnownBlock = NULL;
hashLastUnknownBlock = uint256(0);
nBlocksToDownload = 0;
nBlocksInFlight = 0;
nLastBlockReceive = 0;
nLastBlockProcess = 0;
}
};
// Map maintaining per-node state. Requires cs_main.
map<NodeId, CNodeState> mapNodeState;
// Requires cs_main.
CNodeState *State(NodeId pnode) {
map<NodeId, CNodeState>::iterator it = mapNodeState.find(pnode);
if (it == mapNodeState.end())
return NULL;
return &it->second;
}
int GetHeight()
{
LOCK(cs_main);
return chainActive.Height();
}
void InitializeNode(NodeId nodeid, const CNode *pnode) {
LOCK(cs_main);
CNodeState &state = mapNodeState.insert(std::make_pair(nodeid, CNodeState())).first->second;
state.name = pnode->addrName;
}
void FinalizeNode(NodeId nodeid) {
LOCK(cs_main);
CNodeState *state = State(nodeid);
BOOST_FOREACH(const QueuedBlock& entry, state->vBlocksInFlight)
mapBlocksInFlight.erase(entry.hash);
BOOST_FOREACH(const uint256& hash, state->vBlocksToDownload)
mapBlocksToDownload.erase(hash);
EraseOrphansFor(nodeid);
mapNodeState.erase(nodeid);
}
// Requires cs_main.
void MarkBlockAsReceived(const uint256 &hash, NodeId nodeFrom = -1) {
map<uint256, pair<NodeId, list<uint256>::iterator> >::iterator itToDownload = mapBlocksToDownload.find(hash);
if (itToDownload != mapBlocksToDownload.end()) {
CNodeState *state = State(itToDownload->second.first);
state->vBlocksToDownload.erase(itToDownload->second.second);
state->nBlocksToDownload--;
mapBlocksToDownload.erase(itToDownload);
}
map<uint256, pair<NodeId, list<QueuedBlock>::iterator> >::iterator itInFlight = mapBlocksInFlight.find(hash);
if (itInFlight != mapBlocksInFlight.end()) {
CNodeState *state = State(itInFlight->second.first);
state->vBlocksInFlight.erase(itInFlight->second.second);
state->nBlocksInFlight--;
if (itInFlight->second.first == nodeFrom)
state->nLastBlockReceive = GetTimeMicros();
mapBlocksInFlight.erase(itInFlight);
}
}
// Requires cs_main.
bool AddBlockToQueue(NodeId nodeid, const uint256 &hash) {
if (mapBlocksToDownload.count(hash) || mapBlocksInFlight.count(hash))
return false;
CNodeState *state = State(nodeid);
if (state == NULL)
return false;
list<uint256>::iterator it = state->vBlocksToDownload.insert(state->vBlocksToDownload.end(), hash);
state->nBlocksToDownload++;
if (state->nBlocksToDownload > 5000)
Misbehaving(nodeid, 10);
mapBlocksToDownload[hash] = std::make_pair(nodeid, it);
return true;
}
// Requires cs_main.
void MarkBlockAsInFlight(NodeId nodeid, const uint256 &hash) {
CNodeState *state = State(nodeid);
assert(state != NULL);
// Make sure it's not listed somewhere already.
MarkBlockAsReceived(hash);
QueuedBlock newentry = {hash, GetTimeMicros(), state->nBlocksInFlight};
if (state->nBlocksInFlight == 0)
state->nLastBlockReceive = newentry.nTime; // Reset when a first request is sent.
list<QueuedBlock>::iterator it = state->vBlocksInFlight.insert(state->vBlocksInFlight.end(), newentry);
state->nBlocksInFlight++;
mapBlocksInFlight[hash] = std::make_pair(nodeid, it);
}
/** Check whether the last unknown block a peer advertized is not yet known. */
void ProcessBlockAvailability(NodeId nodeid) {
CNodeState *state = State(nodeid);
assert(state != NULL);
if (state->hashLastUnknownBlock != 0) {
BlockMap::iterator itOld = mapBlockIndex.find(state->hashLastUnknownBlock);
if (itOld != mapBlockIndex.end() && itOld->second->nChainWork > 0) {
if (state->pindexBestKnownBlock == NULL || itOld->second->nChainWork >= state->pindexBestKnownBlock->nChainWork)
state->pindexBestKnownBlock = itOld->second;
state->hashLastUnknownBlock = uint256(0);
}
}
}
/** Update tracking information about which blocks a peer is assumed to have. */
void UpdateBlockAvailability(NodeId nodeid, const uint256 &hash) {
CNodeState *state = State(nodeid);
assert(state != NULL);
ProcessBlockAvailability(nodeid);
BlockMap::iterator it = mapBlockIndex.find(hash);
if (it != mapBlockIndex.end() && it->second->nChainWork > 0) {
// An actually better block was announced.
if (state->pindexBestKnownBlock == NULL || it->second->nChainWork >= state->pindexBestKnownBlock->nChainWork)
state->pindexBestKnownBlock = it->second;
} else {
// An unknown block was announced; just assume that the latest one is the best one.
state->hashLastUnknownBlock = hash;
}
}
} // anon namespace
bool GetNodeStateStats(NodeId nodeid, CNodeStateStats &stats) {
LOCK(cs_main);
CNodeState *state = State(nodeid);
if (state == NULL)
return false;
stats.nMisbehavior = state->nMisbehavior;
stats.nSyncHeight = state->pindexBestKnownBlock ? state->pindexBestKnownBlock->nHeight : -1;
return true;
}
void RegisterNodeSignals(CNodeSignals& nodeSignals)
{
nodeSignals.GetHeight.connect(&GetHeight);
nodeSignals.ProcessMessages.connect(&ProcessMessages);
nodeSignals.SendMessages.connect(&SendMessages);
nodeSignals.InitializeNode.connect(&InitializeNode);
nodeSignals.FinalizeNode.connect(&FinalizeNode);
}
void UnregisterNodeSignals(CNodeSignals& nodeSignals)
{
nodeSignals.GetHeight.disconnect(&GetHeight);
nodeSignals.ProcessMessages.disconnect(&ProcessMessages);
nodeSignals.SendMessages.disconnect(&SendMessages);
nodeSignals.InitializeNode.disconnect(&InitializeNode);
nodeSignals.FinalizeNode.disconnect(&FinalizeNode);
}
CBlockIndex* FindForkInGlobalIndex(const CChain& chain, const CBlockLocator& locator)
{
// Find the first block the caller has in the main chain
BOOST_FOREACH(const uint256& hash, locator.vHave) {
BlockMap::iterator mi = mapBlockIndex.find(hash);
if (mi != mapBlockIndex.end())
{
CBlockIndex* pindex = (*mi).second;
if (chain.Contains(pindex))
return pindex;
}
}
return chain.Genesis();
}
CCoinsViewCache *pcoinsTip = NULL;
CBlockTreeDB *pblocktree = NULL;
//////////////////////////////////////////////////////////////////////////////
//
// mapOrphanTransactions
//
bool AddOrphanTx(const CTransaction& tx, NodeId peer)
{
uint256 hash = tx.GetHash();
if (mapOrphanTransactions.count(hash))
return false;
// Ignore big transactions, to avoid a
// send-big-orphans memory exhaustion attack. If a peer has a legitimate
// large transaction with a missing parent then we assume
// it will rebroadcast it later, after the parent transaction(s)
// have been mined or received.
// 10,000 orphans, each of which is at most 5,000 bytes big is
// at most 500 megabytes of orphans:
unsigned int sz = tx.GetSerializeSize(SER_NETWORK, CTransaction::CURRENT_VERSION);
if (sz > 5000)
{
LogPrint("mempool", "ignoring large orphan tx (size: %u, hash: %s)\n", sz, hash.ToString());
return false;
}
mapOrphanTransactions[hash].tx = tx;
mapOrphanTransactions[hash].fromPeer = peer;
BOOST_FOREACH(const CTxIn& txin, tx.vin)
mapOrphanTransactionsByPrev[txin.prevout.hash].insert(hash);
LogPrint("mempool", "stored orphan tx %s (mapsz %u prevsz %u)\n", hash.ToString(),
mapOrphanTransactions.size(), mapOrphanTransactionsByPrev.size());
return true;
}
void static EraseOrphanTx(uint256 hash)
{
map<uint256, COrphanTx>::iterator it = mapOrphanTransactions.find(hash);
if (it == mapOrphanTransactions.end())
return;
BOOST_FOREACH(const CTxIn& txin, it->second.tx.vin)
{
map<uint256, set<uint256> >::iterator itPrev = mapOrphanTransactionsByPrev.find(txin.prevout.hash);
if (itPrev == mapOrphanTransactionsByPrev.end())
continue;
itPrev->second.erase(hash);
if (itPrev->second.empty())
mapOrphanTransactionsByPrev.erase(itPrev);
}
mapOrphanTransactions.erase(it);
}
void EraseOrphansFor(NodeId peer)
{
int nErased = 0;
map<uint256, COrphanTx>::iterator iter = mapOrphanTransactions.begin();
while (iter != mapOrphanTransactions.end())
{
map<uint256, COrphanTx>::iterator maybeErase = iter++; // increment to avoid iterator becoming invalid
if (maybeErase->second.fromPeer == peer)
{
EraseOrphanTx(maybeErase->second.tx.GetHash());
++nErased;
}
}
if (nErased > 0) LogPrint("mempool", "Erased %d orphan tx from peer %d\n", nErased, peer);
}
unsigned int LimitOrphanTxSize(unsigned int nMaxOrphans)
{
unsigned int nEvicted = 0;
while (mapOrphanTransactions.size() > nMaxOrphans)
{
// Evict a random orphan:
uint256 randomhash = GetRandHash();
map<uint256, COrphanTx>::iterator it = mapOrphanTransactions.lower_bound(randomhash);
if (it == mapOrphanTransactions.end())
it = mapOrphanTransactions.begin();
EraseOrphanTx(it->first);
++nEvicted;
}
return nEvicted;
}
bool IsStandardTx(const CTransaction& tx, string& reason)
{
AssertLockHeld(cs_main);
if (tx.nVersion > CTransaction::CURRENT_VERSION || tx.nVersion < 1) {
reason = "version";
return false;
}
// Treat non-final transactions as non-standard to prevent a specific type
// of double-spend attack, as well as DoS attacks. (if the transaction
// can't be mined, the attacker isn't expending resources broadcasting it)
// Basically we don't want to propagate transactions that can't be included in
// the next block.
//
// However, IsFinalTx() is confusing... Without arguments, it uses
// chainActive.Height() to evaluate nLockTime; when a block is accepted, chainActive.Height()
// is set to the value of nHeight in the block. However, when IsFinalTx()
// is called within CBlock::AcceptBlock(), the height of the block *being*
// evaluated is what is used. Thus if we want to know if a transaction can
// be part of the *next* block, we need to call IsFinalTx() with one more
// than chainActive.Height().
//
// Timestamps on the other hand don't get any special treatment, because we
// can't know what timestamp the next block will have, and there aren't
// timestamp applications where it matters.
if (!IsFinalTx(tx, chainActive.Height() + 1)) {
reason = "non-final";
return false;
}
// Extremely large transactions with lots of inputs can cost the network
// almost as much to process as they cost the sender in fees, because
// computing signature hashes is O(ninputs*txsize). Limiting transactions
// to MAX_STANDARD_TX_SIZE mitigates CPU exhaustion attacks.
unsigned int sz = tx.GetSerializeSize(SER_NETWORK, CTransaction::CURRENT_VERSION);
if (sz >= MAX_STANDARD_TX_SIZE) {
reason = "tx-size";
return false;
}
BOOST_FOREACH(const CTxIn& txin, tx.vin)
{
// Biggest 'standard' txin is a 15-of-15 P2SH multisig with compressed
// keys. (remember the 520 byte limit on redeemScript size) That works
// out to a (15*(33+1))+3=513 byte redeemScript, 513+1+15*(73+1)+3=1627
// bytes of scriptSig, which we round off to 1650 bytes for some minor
// future-proofing. That's also enough to spend a 20-of-20
// CHECKMULTISIG scriptPubKey, though such a scriptPubKey is not
// considered standard)
if (txin.scriptSig.size() > 1650) {
reason = "scriptsig-size";
return false;
}
if (!txin.scriptSig.IsPushOnly()) {
reason = "scriptsig-not-pushonly";
return false;
}
if (!txin.scriptSig.HasCanonicalPushes()) {
reason = "scriptsig-non-canonical-push";
return false;
}
}
unsigned int nDataOut = 0;
txnouttype whichType;
BOOST_FOREACH(const CTxOut& txout, tx.vout) {
if (!::IsStandard(txout.scriptPubKey, whichType)) {
reason = "scriptpubkey";
return false;
}
if (whichType == TX_NULL_DATA)
nDataOut++;
else if ((whichType == TX_MULTISIG) && (!fIsBareMultisigStd)) {
reason = "bare-multisig";
return false;
} else if (txout.IsDust(::minRelayTxFee)) {
reason = "dust";
return false;
}
}
// only one OP_RETURN txout is permitted
if (nDataOut > 1) {
reason = "multi-op-return";
return false;
}
return true;
}
bool IsFinalTx(const CTransaction &tx, int nBlockHeight, int64_t nBlockTime)
{
AssertLockHeld(cs_main);
// Time based nLockTime implemented in 0.1.6
if (tx.nLockTime == 0)
return true;
if (nBlockHeight == 0)
nBlockHeight = chainActive.Height();
if (nBlockTime == 0)
nBlockTime = GetAdjustedTime();
if ((int64_t)tx.nLockTime < ((int64_t)tx.nLockTime < LOCKTIME_THRESHOLD ? (int64_t)nBlockHeight : nBlockTime))
return true;
BOOST_FOREACH(const CTxIn& txin, tx.vin)
if (!txin.IsFinal())
return false;
return true;
}
//
// Check transaction inputs to mitigate two
// potential denial-of-service attacks:
//
// 1. scriptSigs with extra data stuffed into them,
// not consumed by scriptPubKey (or P2SH script)
// 2. P2SH scripts with a crazy number of expensive
// CHECKSIG/CHECKMULTISIG operations
//
bool AreInputsStandard(const CTransaction& tx, const CCoinsViewCache& mapInputs)
{
if (tx.IsCoinBase())
return true; // Coinbases don't use vin normally
for (unsigned int i = 0; i < tx.vin.size(); i++)
{
const CTxOut& prev = mapInputs.GetOutputFor(tx.vin[i]);
vector<vector<unsigned char> > vSolutions;
txnouttype whichType;
// get the scriptPubKey corresponding to this input:
const CScript& prevScript = prev.scriptPubKey;
if (!Solver(prevScript, whichType, vSolutions))
return false;
int nArgsExpected = ScriptSigArgsExpected(whichType, vSolutions);
if (nArgsExpected < 0)
return false;
// Transactions with extra stuff in their scriptSigs are
// non-standard. Note that this EvalScript() call will
// be quick, because if there are any operations
// beside "push data" in the scriptSig
// IsStandard() will have already returned false
// and this method isn't called.
vector<vector<unsigned char> > stack;
if (!EvalScript(stack, tx.vin[i].scriptSig, false, BaseSignatureChecker()))
return false;
if (whichType == TX_SCRIPTHASH)
{
if (stack.empty())
return false;
CScript subscript(stack.back().begin(), stack.back().end());
vector<vector<unsigned char> > vSolutions2;
txnouttype whichType2;
if (Solver(subscript, whichType2, vSolutions2))
{
int tmpExpected = ScriptSigArgsExpected(whichType2, vSolutions2);
if (tmpExpected < 0)
return false;
nArgsExpected += tmpExpected;
}
else
{
// Any other Script with less than 15 sigops OK:
unsigned int sigops = subscript.GetSigOpCount(true);
// ... extra data left on the stack after execution is OK, too:
return (sigops <= MAX_P2SH_SIGOPS);
}
}
if (stack.size() != (unsigned int)nArgsExpected)
return false;
}
return true;
}
unsigned int GetLegacySigOpCount(const CTransaction& tx)
{
unsigned int nSigOps = 0;
BOOST_FOREACH(const CTxIn& txin, tx.vin)
{
nSigOps += txin.scriptSig.GetSigOpCount(false);
}
BOOST_FOREACH(const CTxOut& txout, tx.vout)
{
nSigOps += txout.scriptPubKey.GetSigOpCount(false);
}
return nSigOps;
}
unsigned int GetP2SHSigOpCount(const CTransaction& tx, const CCoinsViewCache& inputs)
{
if (tx.IsCoinBase())
return 0;
unsigned int nSigOps = 0;
for (unsigned int i = 0; i < tx.vin.size(); i++)
{
const CTxOut &prevout = inputs.GetOutputFor(tx.vin[i]);
if (prevout.scriptPubKey.IsPayToScriptHash())
nSigOps += prevout.scriptPubKey.GetSigOpCount(tx.vin[i].scriptSig);
}
return nSigOps;
}
bool CheckTransaction(const CTransaction& tx, CValidationState &state)
{
// Basic checks that don't depend on any context
if (tx.vin.empty())
return state.DoS(10, error("CheckTransaction() : vin empty"),
REJECT_INVALID, "bad-txns-vin-empty");
if (tx.vout.empty())
return state.DoS(10, error("CheckTransaction() : vout empty"),
REJECT_INVALID, "bad-txns-vout-empty");
// Size limits
if (::GetSerializeSize(tx, SER_NETWORK, PROTOCOL_VERSION) > MAX_BLOCK_SIZE)
return state.DoS(100, error("CheckTransaction() : size limits failed"),
REJECT_INVALID, "bad-txns-oversize");
// Check for negative or overflow output values
CAmount nValueOut = 0;
BOOST_FOREACH(const CTxOut& txout, tx.vout)
{
if (txout.nValue < 0)
return state.DoS(100, error("CheckTransaction() : txout.nValue negative"),
REJECT_INVALID, "bad-txns-vout-negative");
if (txout.nValue > MAX_MONEY)
return state.DoS(100, error("CheckTransaction() : txout.nValue too high"),
REJECT_INVALID, "bad-txns-vout-toolarge");
nValueOut += txout.nValue;
if (!MoneyRange(nValueOut))
return state.DoS(100, error("CheckTransaction() : txout total out of range"),
REJECT_INVALID, "bad-txns-txouttotal-toolarge");
}
// Check for duplicate inputs
set<COutPoint> vInOutPoints;
BOOST_FOREACH(const CTxIn& txin, tx.vin)
{
if (vInOutPoints.count(txin.prevout))
return state.DoS(100, error("CheckTransaction() : duplicate inputs"),
REJECT_INVALID, "bad-txns-inputs-duplicate");
vInOutPoints.insert(txin.prevout);
}
if (tx.IsCoinBase())
{
if (tx.vin[0].scriptSig.size() < 2 || tx.vin[0].scriptSig.size() > 100)
return state.DoS(100, error("CheckTransaction() : coinbase script size"),
REJECT_INVALID, "bad-cb-length");
}
else
{
BOOST_FOREACH(const CTxIn& txin, tx.vin)
if (txin.prevout.IsNull())
return state.DoS(10, error("CheckTransaction() : prevout is null"),
REJECT_INVALID, "bad-txns-prevout-null");
}
return true;
}
CAmount GetMinRelayFee(const CTransaction& tx, unsigned int nBytes, bool fAllowFree)
{
{
LOCK(mempool.cs);
uint256 hash = tx.GetHash();
double dPriorityDelta = 0;
CAmount nFeeDelta = 0;
mempool.ApplyDeltas(hash, dPriorityDelta, nFeeDelta);
if (dPriorityDelta > 0 || nFeeDelta > 0)
return 0;
}
CAmount nMinFee = ::minRelayTxFee.GetFee(nBytes);
if (fAllowFree)
{
// There is a free transaction area in blocks created by most miners,
// * If we are relaying we allow transactions up to DEFAULT_BLOCK_PRIORITY_SIZE - 1000
// to be considered to fall into this category. We don't want to encourage sending
// multiple transactions instead of one big transaction to avoid fees.
if (nBytes < (DEFAULT_BLOCK_PRIORITY_SIZE - 1000))
nMinFee = 0;
}
if (!MoneyRange(nMinFee))
nMinFee = MAX_MONEY;
return nMinFee;
}
bool AcceptToMemoryPool(CTxMemPool& pool, CValidationState &state, const CTransaction &tx, bool fLimitFree,
bool* pfMissingInputs, bool fRejectInsaneFee)
{
AssertLockHeld(cs_main);
if (pfMissingInputs)
*pfMissingInputs = false;
if (!CheckTransaction(tx, state))
return error("AcceptToMemoryPool: : CheckTransaction failed");
// Coinbase is only valid in a block, not as a loose transaction
if (tx.IsCoinBase())
return state.DoS(100, error("AcceptToMemoryPool: : coinbase as individual tx"),
REJECT_INVALID, "coinbase");
// Rather not work on nonstandard transactions (unless -testnet/-regtest)
string reason;
if (Params().RequireStandard() && !IsStandardTx(tx, reason))
return state.DoS(0,
error("AcceptToMemoryPool : nonstandard transaction: %s", reason),
REJECT_NONSTANDARD, reason);
// is it already in the memory pool?
uint256 hash = tx.GetHash();
if (pool.exists(hash))
return false;
// Check for conflicts with in-memory transactions
{
LOCK(pool.cs); // protect pool.mapNextTx
for (unsigned int i = 0; i < tx.vin.size(); i++)
{
COutPoint outpoint = tx.vin[i].prevout;
if (pool.mapNextTx.count(outpoint))
{
// Disable replacement feature for now
return false;
}
}
}
{
CCoinsView dummy;
CCoinsViewCache view(dummy);
CAmount nValueIn = 0;
{
LOCK(pool.cs);
CCoinsViewMemPool viewMemPool(*pcoinsTip, pool);
view.SetBackend(viewMemPool);
// do we already have it?
if (view.HaveCoins(hash))
return false;
// do all inputs exist?
// Note that this does not check for the presence of actual outputs (see the next check for that),
// only helps filling in pfMissingInputs (to determine missing vs spent).
BOOST_FOREACH(const CTxIn txin, tx.vin) {
if (!view.HaveCoins(txin.prevout.hash)) {
if (pfMissingInputs)
*pfMissingInputs = true;
return false;
}
}
// are the actual inputs available?
if (!view.HaveInputs(tx))
return state.Invalid(error("AcceptToMemoryPool : inputs already spent"),
REJECT_DUPLICATE, "bad-txns-inputs-spent");
// Bring the best block into scope
view.GetBestBlock();
nValueIn = view.GetValueIn(tx);
// we have all inputs cached now, so switch back to dummy, so we don't need to keep lock on mempool
view.SetBackend(dummy);
}
// Check for non-standard pay-to-script-hash in inputs
if (Params().RequireStandard() && !AreInputsStandard(tx, view))
return error("AcceptToMemoryPool: : nonstandard transaction input");
// Check that the transaction doesn't have an excessive number of
// sigops, making it impossible to mine. Since the coinbase transaction
// itself can contain sigops MAX_TX_SIGOPS is less than
// MAX_BLOCK_SIGOPS; we still consider this an invalid rather than
// merely non-standard transaction.
unsigned int nSigOps = GetLegacySigOpCount(tx);
nSigOps += GetP2SHSigOpCount(tx, view);
if (nSigOps > MAX_TX_SIGOPS)
return state.DoS(0,
error("AcceptToMemoryPool : too many sigops %s, %d > %d",
hash.ToString(), nSigOps, MAX_TX_SIGOPS),
REJECT_NONSTANDARD, "bad-txns-too-many-sigops");
CAmount nValueOut = tx.GetValueOut();
CAmount nFees = nValueIn-nValueOut;
double dPriority = view.GetPriority(tx, chainActive.Height());
CTxMemPoolEntry entry(tx, nFees, GetTime(), dPriority, chainActive.Height());
unsigned int nSize = entry.GetTxSize();
// Don't accept it if it can't get into a block
CAmount txMinFee = GetMinRelayFee(tx, nSize, true);
if (fLimitFree && nFees < txMinFee)
return state.DoS(0, error("AcceptToMemoryPool : not enough fees %s, %d < %d",
hash.ToString(), nFees, txMinFee),
REJECT_INSUFFICIENTFEE, "insufficient fee");
// Continuously rate-limit free (really, very-low-fee)transactions
// This mitigates 'penny-flooding' -- sending thousands of free transactions just to
// be annoying or make others' transactions take longer to confirm.
if (fLimitFree && nFees < ::minRelayTxFee.GetFee(nSize))
{
static CCriticalSection csFreeLimiter;
static double dFreeCount;
static int64_t nLastTime;
int64_t nNow = GetTime();
LOCK(csFreeLimiter);
// Use an exponentially decaying ~10-minute window:
dFreeCount *= pow(1.0 - 1.0/600.0, (double)(nNow - nLastTime));
nLastTime = nNow;
// -limitfreerelay unit is thousand-bytes-per-minute
// At default rate it would take over a month to fill 1GB
if (dFreeCount >= GetArg("-limitfreerelay", 15)*10*1000)
return state.DoS(0, error("AcceptToMemoryPool : free transaction rejected by rate limiter"),
REJECT_INSUFFICIENTFEE, "insufficient priority");
LogPrint("mempool", "Rate limit dFreeCount: %g => %g\n", dFreeCount, dFreeCount+nSize);
dFreeCount += nSize;
}
if (fRejectInsaneFee && nFees > ::minRelayTxFee.GetFee(nSize) * 10000)
return error("AcceptToMemoryPool: : insane fees %s, %d > %d",
hash.ToString(),
nFees, ::minRelayTxFee.GetFee(nSize) * 10000);
// Check against previous transactions
// This is done last to help prevent CPU exhaustion denial-of-service attacks.
if (!CheckInputs(tx, state, view, true, STANDARD_SCRIPT_VERIFY_FLAGS, true))
{
return error("AcceptToMemoryPool: : ConnectInputs failed %s", hash.ToString());
}
// Store transaction in memory
pool.addUnchecked(hash, entry);
}
SyncWithWallets(tx, NULL);
return true;
}
// Return transaction in tx, and if it was found inside a block, its hash is placed in hashBlock
bool GetTransaction(const uint256 &hash, CTransaction &txOut, uint256 &hashBlock, bool fAllowSlow)
{
CBlockIndex *pindexSlow = NULL;
{
LOCK(cs_main);
{
if (mempool.lookup(hash, txOut))
{
return true;
}
}
if (fTxIndex) {
CDiskTxPos postx;
if (pblocktree->ReadTxIndex(hash, postx)) {
CAutoFile file(OpenBlockFile(postx, true), SER_DISK, CLIENT_VERSION);
CBlockHeader header;
try {
file >> header;
fseek(file, postx.nTxOffset, SEEK_CUR);
file >> txOut;
} catch (std::exception &e) {
return error("%s : Deserialize or I/O error - %s", __func__, e.what());
}
hashBlock = header.GetHash();
if (txOut.GetHash() != hash)
return error("%s : txid mismatch", __func__);
return true;
}
}
if (fAllowSlow) { // use coin database to locate block that contains transaction, and scan it
int nHeight = -1;
{
CCoinsViewCache &view = *pcoinsTip;
const CCoins* coins = view.AccessCoins(hash);
if (coins)
nHeight = coins->nHeight;
}
if (nHeight > 0)
pindexSlow = chainActive[nHeight];
}
}
if (pindexSlow) {
CBlock block;
if (ReadBlockFromDisk(block, pindexSlow)) {
BOOST_FOREACH(const CTransaction &tx, block.vtx) {
if (tx.GetHash() == hash) {
txOut = tx;
hashBlock = pindexSlow->GetBlockHash();
return true;
}
}
}
}
return false;
}
//////////////////////////////////////////////////////////////////////////////
//
// CBlock and CBlockIndex
//
bool WriteBlockToDisk(CBlock& block, CDiskBlockPos& pos)
{
// Open history file to append
CAutoFile fileout(OpenBlockFile(pos), SER_DISK, CLIENT_VERSION);
if (!fileout)
return error("WriteBlockToDisk : OpenBlockFile failed");
// Write index header
unsigned int nSize = fileout.GetSerializeSize(block);
fileout << FLATDATA(Params().MessageStart()) << nSize;
// Write block
long fileOutPos = ftell(fileout);
if (fileOutPos < 0)
return error("WriteBlockToDisk : ftell failed");
pos.nPos = (unsigned int)fileOutPos;
fileout << block;
// Flush stdio buffers and commit to disk before returning
fflush(fileout);
if (!IsInitialBlockDownload())
FileCommit(fileout);
return true;
}
bool ReadBlockFromDisk(CBlock& block, const CDiskBlockPos& pos)
{
block.SetNull();
// Open history file to read
CAutoFile filein(OpenBlockFile(pos, true), SER_DISK, CLIENT_VERSION);
if (!filein)
return error("ReadBlockFromDisk : OpenBlockFile failed");
// Read block
try {
filein >> block;
}
catch (std::exception &e) {
return error("%s : Deserialize or I/O error - %s", __func__, e.what());
}
// Check the header
if (!CheckProofOfWork(block.GetHash(), block.nBits))
return error("ReadBlockFromDisk : Errors in block header");
return true;
}
bool ReadBlockFromDisk(CBlock& block, const CBlockIndex* pindex)
{
if (!ReadBlockFromDisk(block, pindex->GetBlockPos()))
return false;
if (block.GetHash() != pindex->GetBlockHash())
return error("ReadBlockFromDisk(CBlock&, CBlockIndex*) : GetHash() doesn't match index");
return true;
}
uint256 static GetOrphanRoot(const uint256& hash)
{
map<uint256, COrphanBlock*>::iterator it = mapOrphanBlocks.find(hash);
if (it == mapOrphanBlocks.end())
return hash;
// Work back to the first block in the orphan chain
do {
map<uint256, COrphanBlock*>::iterator it2 = mapOrphanBlocks.find(it->second->hashPrev);
if (it2 == mapOrphanBlocks.end())
return it->first;
it = it2;
} while(true);
}
// Remove a random orphan block (which does not have any dependent orphans).
void static PruneOrphanBlocks()
{
if (mapOrphanBlocksByPrev.size() <= (size_t)std::max((int64_t)0, GetArg("-maxorphanblocks", DEFAULT_MAX_ORPHAN_BLOCKS)))
return;
// Pick a random orphan block.
int pos = insecure_rand() % mapOrphanBlocksByPrev.size();
std::multimap<uint256, COrphanBlock*>::iterator it = mapOrphanBlocksByPrev.begin();
while (pos--) it++;
// As long as this block has other orphans depending on it, move to one of those successors.
do {
std::multimap<uint256, COrphanBlock*>::iterator it2 = mapOrphanBlocksByPrev.find(it->second->hashBlock);
if (it2 == mapOrphanBlocksByPrev.end())
break;
it = it2;
} while(1);
uint256 hash = it->second->hashBlock;
delete it->second;
mapOrphanBlocksByPrev.erase(it);
mapOrphanBlocks.erase(hash);
}
CAmount GetBlockValue(int nHeight, const CAmount& nFees)
{
int64_t nSubsidy = 50 * COIN;
int halvings = nHeight / Params().SubsidyHalvingInterval();
// Force block reward to zero when right shift is undefined.
if (halvings >= 64)
return nFees;
// Subsidy is cut in half every 210,000 blocks which will occur approximately every 4 years.
nSubsidy >>= halvings;
return nSubsidy + nFees;
}
bool IsInitialBlockDownload()
{
LOCK(cs_main);
if (fImporting || fReindex || chainActive.Height() < Checkpoints::GetTotalBlocksEstimate())
return true;
static int64_t nLastUpdate;
static CBlockIndex* pindexLastBest;
if (chainActive.Tip() != pindexLastBest)
{
pindexLastBest = chainActive.Tip();
nLastUpdate = GetTime();
}
return (GetTime() - nLastUpdate < 10 &&
chainActive.Tip()->GetBlockTime() < GetTime() - 24 * 60 * 60);
}
bool fLargeWorkForkFound = false;
bool fLargeWorkInvalidChainFound = false;
CBlockIndex *pindexBestForkTip = NULL, *pindexBestForkBase = NULL;
void CheckForkWarningConditions()
{
AssertLockHeld(cs_main);
// Before we get past initial download, we cannot reliably alert about forks
// (we assume we don't get stuck on a fork before the last checkpoint)
if (IsInitialBlockDownload())
return;
// If our best fork is no longer within 72 blocks (+/- 12 hours if no one mines it)
// of our head, drop it
if (pindexBestForkTip && chainActive.Height() - pindexBestForkTip->nHeight >= 72)
pindexBestForkTip = NULL;
if (pindexBestForkTip || (pindexBestInvalid && pindexBestInvalid->nChainWork > chainActive.Tip()->nChainWork + (chainActive.Tip()->GetBlockWork() * 6)))
{
if (!fLargeWorkForkFound)
{
std::string strCmd = GetArg("-alertnotify", "");
if (!strCmd.empty())
{
std::string warning = std::string("'Warning: Large-work fork detected, forking after block ") +
pindexBestForkBase->phashBlock->ToString() + std::string("'");
boost::replace_all(strCmd, "%s", warning);
boost::thread t(runCommand, strCmd); // thread runs free
}
}
if (pindexBestForkTip)
{
LogPrintf("CheckForkWarningConditions: Warning: Large valid fork found\n forking the chain at height %d (%s)\n lasting to height %d (%s).\nChain state database corruption likely.\n",
pindexBestForkBase->nHeight, pindexBestForkBase->phashBlock->ToString(),
pindexBestForkTip->nHeight, pindexBestForkTip->phashBlock->ToString());
fLargeWorkForkFound = true;
}
else
{
LogPrintf("CheckForkWarningConditions: Warning: Found invalid chain at least ~6 blocks longer than our best chain.\nChain state database corruption likely.\n");
fLargeWorkInvalidChainFound = true;
}
}
else
{
fLargeWorkForkFound = false;
fLargeWorkInvalidChainFound = false;
}
}
void CheckForkWarningConditionsOnNewFork(CBlockIndex* pindexNewForkTip)
{
AssertLockHeld(cs_main);
// If we are on a fork that is sufficiently large, set a warning flag
CBlockIndex* pfork = pindexNewForkTip;
CBlockIndex* plonger = chainActive.Tip();
while (pfork && pfork != plonger)
{
while (plonger && plonger->nHeight > pfork->nHeight)
plonger = plonger->pprev;
if (pfork == plonger)
break;
pfork = pfork->pprev;
}
// We define a condition which we should warn the user about as a fork of at least 7 blocks
// who's tip is within 72 blocks (+/- 12 hours if no one mines it) of ours
// We use 7 blocks rather arbitrarily as it represents just under 10% of sustained network
// hash rate operating on the fork.
// or a chain that is entirely longer than ours and invalid (note that this should be detected by both)
// We define it this way because it allows us to only store the highest fork tip (+ base) which meets
// the 7-block condition and from this always have the most-likely-to-cause-warning fork
if (pfork && (!pindexBestForkTip || (pindexBestForkTip && pindexNewForkTip->nHeight > pindexBestForkTip->nHeight)) &&
pindexNewForkTip->nChainWork - pfork->nChainWork > (pfork->GetBlockWork() * 7) &&
chainActive.Height() - pindexNewForkTip->nHeight < 72)
{
pindexBestForkTip = pindexNewForkTip;
pindexBestForkBase = pfork;
}
CheckForkWarningConditions();
}
// Requires cs_main.
void Misbehaving(NodeId pnode, int howmuch)
{
if (howmuch == 0)
return;
CNodeState *state = State(pnode);
if (state == NULL)
return;
state->nMisbehavior += howmuch;
int banscore = GetArg("-banscore", 100);
if (state->nMisbehavior >= banscore && state->nMisbehavior - howmuch < banscore)
{
LogPrintf("Misbehaving: %s (%d -> %d) BAN THRESHOLD EXCEEDED\n", state->name, state->nMisbehavior-howmuch, state->nMisbehavior);
state->fShouldBan = true;
} else
LogPrintf("Misbehaving: %s (%d -> %d)\n", state->name, state->nMisbehavior-howmuch, state->nMisbehavior);
}
void static InvalidChainFound(CBlockIndex* pindexNew)
{
if (!pindexBestInvalid || pindexNew->nChainWork > pindexBestInvalid->nChainWork)
pindexBestInvalid = pindexNew;
LogPrintf("InvalidChainFound: invalid block=%s height=%d log2_work=%.8g date=%s\n",
pindexNew->GetBlockHash().ToString(), pindexNew->nHeight,
log(pindexNew->nChainWork.getdouble())/log(2.0), DateTimeStrFormat("%Y-%m-%d %H:%M:%S",
pindexNew->GetBlockTime()));
LogPrintf("InvalidChainFound: current best=%s height=%d log2_work=%.8g date=%s\n",
chainActive.Tip()->GetBlockHash().ToString(), chainActive.Height(), log(chainActive.Tip()->nChainWork.getdouble())/log(2.0),
DateTimeStrFormat("%Y-%m-%d %H:%M:%S", chainActive.Tip()->GetBlockTime()));
CheckForkWarningConditions();
}
void static InvalidBlockFound(CBlockIndex *pindex, const CValidationState &state) {
int nDoS = 0;
if (state.IsInvalid(nDoS)) {
std::map<uint256, NodeId>::iterator it = mapBlockSource.find(pindex->GetBlockHash());
if (it != mapBlockSource.end() && State(it->second)) {
CBlockReject reject = {state.GetRejectCode(), state.GetRejectReason(), pindex->GetBlockHash()};
State(it->second)->rejects.push_back(reject);
if (nDoS > 0)
Misbehaving(it->second, nDoS);
}
}
if (!state.CorruptionPossible()) {
pindex->nStatus |= BLOCK_FAILED_VALID;
pblocktree->WriteBlockIndex(CDiskBlockIndex(pindex));
setBlockIndexValid.erase(pindex);
InvalidChainFound(pindex);
}
}
void UpdateCoins(const CTransaction& tx, CValidationState &state, CCoinsViewCache &inputs, CTxUndo &txundo, int nHeight)
{
bool ret;
// mark inputs spent
if (!tx.IsCoinBase()) {
txundo.vprevout.reserve(tx.vin.size());
for (unsigned int i = 0; i < tx.vin.size(); i++) {
const CTxIn &txin = tx.vin[i];
CCoins &coins = inputs.GetCoins(txin.prevout.hash);
txundo.vprevout.push_back(CTxInUndo());
ret = coins.Spend(txin.prevout, txundo.vprevout.back());
assert(ret);
}
}
// add outputs
ret = inputs.SetCoins(tx.GetHash(), CCoins(tx, nHeight));
assert(ret);
}
bool CScriptCheck::operator()() const {
const CScript &scriptSig = ptxTo->vin[nIn].scriptSig;
if (!VerifyScript(scriptSig, scriptPubKey, nFlags, CachingSignatureChecker(*ptxTo, nIn, cacheStore)))
return error("CScriptCheck() : %s:%d VerifySignature failed", ptxTo->GetHash().ToString(), nIn);
return true;
}
bool CheckInputs(const CTransaction& tx, CValidationState &state, const CCoinsViewCache &inputs, bool fScriptChecks, unsigned int flags, bool cacheStore, std::vector<CScriptCheck> *pvChecks)
{
if (!tx.IsCoinBase())
{
if (pvChecks)
pvChecks->reserve(tx.vin.size());
// This doesn't trigger the DoS code on purpose; if it did, it would make it easier
// for an attacker to attempt to split the network.
if (!inputs.HaveInputs(tx))
return state.Invalid(error("CheckInputs() : %s inputs unavailable", tx.GetHash().ToString()));
// While checking, GetBestBlock() refers to the parent block.
// This is also true for mempool checks.
CBlockIndex *pindexPrev = mapBlockIndex.find(inputs.GetBestBlock())->second;
int nSpendHeight = pindexPrev->nHeight + 1;
CAmount nValueIn = 0;
CAmount nFees = 0;
for (unsigned int i = 0; i < tx.vin.size(); i++)
{
const COutPoint &prevout = tx.vin[i].prevout;
const CCoins *coins = inputs.AccessCoins(prevout.hash);
assert(coins);
// If prev is coinbase, check that it's matured
if (coins->IsCoinBase()) {
if (nSpendHeight - coins->nHeight < COINBASE_MATURITY)
return state.Invalid(
error("CheckInputs() : tried to spend coinbase at depth %d", nSpendHeight - coins->nHeight),
REJECT_INVALID, "bad-txns-premature-spend-of-coinbase");
}
// Check for negative or overflow input values
nValueIn += coins->vout[prevout.n].nValue;
if (!MoneyRange(coins->vout[prevout.n].nValue) || !MoneyRange(nValueIn))
return state.DoS(100, error("CheckInputs() : txin values out of range"),
REJECT_INVALID, "bad-txns-inputvalues-outofrange");
}
if (nValueIn < tx.GetValueOut())
return state.DoS(100, error("CheckInputs() : %s value in (%s) < value out (%s)",
tx.GetHash().ToString(), FormatMoney(nValueIn), FormatMoney(tx.GetValueOut())),
REJECT_INVALID, "bad-txns-in-belowout");
// Tally transaction fees
CAmount nTxFee = nValueIn - tx.GetValueOut();
if (nTxFee < 0)
return state.DoS(100, error("CheckInputs() : %s nTxFee < 0", tx.GetHash().ToString()),
REJECT_INVALID, "bad-txns-fee-negative");
nFees += nTxFee;
if (!MoneyRange(nFees))
return state.DoS(100, error("CheckInputs() : nFees out of range"),
REJECT_INVALID, "bad-txns-fee-outofrange");
// The first loop above does all the inexpensive checks.
// Only if ALL inputs pass do we perform expensive ECDSA signature checks.
// Helps prevent CPU exhaustion attacks.
// Skip ECDSA signature verification when connecting blocks
// before the last block chain checkpoint. This is safe because block merkle hashes are
// still computed and checked, and any change will be caught at the next checkpoint.
if (fScriptChecks) {
for (unsigned int i = 0; i < tx.vin.size(); i++) {
const COutPoint &prevout = tx.vin[i].prevout;
const CCoins* coins = inputs.AccessCoins(prevout.hash);
assert(coins);
// Verify signature
CScriptCheck check(*coins, tx, i, flags, cacheStore);
if (pvChecks) {
pvChecks->push_back(CScriptCheck());
check.swap(pvChecks->back());
} else if (!check()) {
if (flags & STANDARD_NOT_MANDATORY_VERIFY_FLAGS) {
// Check whether the failure was caused by a
// non-mandatory script verification check, such as
// non-standard DER encodings or non-null dummy
// arguments; if so, don't trigger DoS protection to
// avoid splitting the network between upgraded and
// non-upgraded nodes.
CScriptCheck check(*coins, tx, i,
flags & ~STANDARD_NOT_MANDATORY_VERIFY_FLAGS, cacheStore);
if (check())
return state.Invalid(false, REJECT_NONSTANDARD, "non-mandatory-script-verify-flag");
}
// Failures of other flags indicate a transaction that is
// invalid in new blocks, e.g. a invalid P2SH. We DoS ban
// such nodes as they are not following the protocol. That
// said during an upgrade careful thought should be taken
// as to the correct behavior - we may want to continue
// peering with non-upgraded nodes even after a soft-fork
// super-majority vote has passed.
return state.DoS(100,false, REJECT_INVALID, "mandatory-script-verify-flag-failed");
}
}
}
}
return true;
}
bool DisconnectBlock(CBlock& block, CValidationState& state, CBlockIndex* pindex, CCoinsViewCache& view, bool* pfClean)
{
assert(pindex->GetBlockHash() == view.GetBestBlock());
if (pfClean)
*pfClean = false;
bool fClean = true;
CBlockUndo blockUndo;
CDiskBlockPos pos = pindex->GetUndoPos();
if (pos.IsNull())
return error("DisconnectBlock() : no undo data available");
if (!blockUndo.ReadFromDisk(pos, pindex->pprev->GetBlockHash()))
return error("DisconnectBlock() : failure reading undo data");
if (blockUndo.vtxundo.size() + 1 != block.vtx.size())
return error("DisconnectBlock() : block and undo data inconsistent");
// undo transactions in reverse order
for (int i = block.vtx.size() - 1; i >= 0; i--) {
const CTransaction &tx = block.vtx[i];
uint256 hash = tx.GetHash();
// Check that all outputs are available and match the outputs in the block itself
// exactly. Note that transactions with only provably unspendable outputs won't
// have outputs available even in the block itself, so we handle that case
// specially with outsEmpty.
CCoins outsEmpty;
CCoins &outs = view.HaveCoins(hash) ? view.GetCoins(hash) : outsEmpty;
outs.ClearUnspendable();
CCoins outsBlock = CCoins(tx, pindex->nHeight);
// The CCoins serialization does not serialize negative numbers.
// No network rules currently depend on the version here, so an inconsistency is harmless
// but it must be corrected before txout nversion ever influences a network rule.
if (outsBlock.nVersion < 0)
outs.nVersion = outsBlock.nVersion;
if (outs != outsBlock)
fClean = fClean && error("DisconnectBlock() : added transaction mismatch? database corrupted");
// remove outputs
outs = CCoins();
// restore inputs
if (i > 0) { // not coinbases
const CTxUndo &txundo = blockUndo.vtxundo[i-1];
if (txundo.vprevout.size() != tx.vin.size())
return error("DisconnectBlock() : transaction and undo data inconsistent");
for (unsigned int j = tx.vin.size(); j-- > 0;) {
const COutPoint &out = tx.vin[j].prevout;
const CTxInUndo &undo = txundo.vprevout[j];
CCoins coins;
view.GetCoins(out.hash, coins); // this can fail if the prevout was already entirely spent
if (undo.nHeight != 0) {
// undo data contains height: this is the last output of the prevout tx being spent
if (!coins.IsPruned())
fClean = fClean && error("DisconnectBlock() : undo data overwriting existing transaction");
coins = CCoins();
coins.fCoinBase = undo.fCoinBase;
coins.nHeight = undo.nHeight;
coins.nVersion = undo.nVersion;
} else {
if (coins.IsPruned())
fClean = fClean && error("DisconnectBlock() : undo data adding output to missing transaction");
}
if (coins.IsAvailable(out.n))
fClean = fClean && error("DisconnectBlock() : undo data overwriting existing output");
if (coins.vout.size() < out.n+1)
coins.vout.resize(out.n+1);
coins.vout[out.n] = undo.txout;
if (!view.SetCoins(out.hash, coins))
return error("DisconnectBlock() : cannot restore coin inputs");
}
}
}
// move best block pointer to prevout block
view.SetBestBlock(pindex->pprev->GetBlockHash());
if (pfClean) {
*pfClean = fClean;
return true;
} else {
return fClean;
}
}
void static FlushBlockFile(bool fFinalize = false)
{
LOCK(cs_LastBlockFile);
CDiskBlockPos posOld(nLastBlockFile, 0);
FILE *fileOld = OpenBlockFile(posOld);
if (fileOld) {
if (fFinalize)
TruncateFile(fileOld, infoLastBlockFile.nSize);
FileCommit(fileOld);
fclose(fileOld);
}
fileOld = OpenUndoFile(posOld);
if (fileOld) {
if (fFinalize)
TruncateFile(fileOld, infoLastBlockFile.nUndoSize);
FileCommit(fileOld);
fclose(fileOld);
}
}
bool FindUndoPos(CValidationState &state, int nFile, CDiskBlockPos &pos, unsigned int nAddSize);
static CCheckQueue<CScriptCheck> scriptcheckqueue(128);
void ThreadScriptCheck() {
RenameThread("bitcoin-scriptch");
scriptcheckqueue.Thread();
}
static int64_t nTimeVerify = 0;
static int64_t nTimeConnect = 0;
static int64_t nTimeIndex = 0;
static int64_t nTimeCallbacks = 0;
static int64_t nTimeTotal = 0;
bool ConnectBlock(CBlock& block, CValidationState& state, CBlockIndex* pindex, CCoinsViewCache& view, bool fJustCheck)
{
AssertLockHeld(cs_main);
// Check it again in case a previous version let a bad block in
if (!CheckBlock(block, state, !fJustCheck, !fJustCheck))
return false;
// verify that the view's current state corresponds to the previous block
uint256 hashPrevBlock = pindex->pprev == NULL ? uint256(0) : pindex->pprev->GetBlockHash();
assert(hashPrevBlock == view.GetBestBlock());
// Special case for the genesis block, skipping connection of its transactions
// (its coinbase is unspendable)
if (block.GetHash() == Params().HashGenesisBlock()) {
view.SetBestBlock(pindex->GetBlockHash());
return true;
}
bool fScriptChecks = pindex->nHeight >= Checkpoints::GetTotalBlocksEstimate();
// Do not allow blocks that contain transactions which 'overwrite' older transactions,
// unless those are already completely spent.
// If such overwrites are allowed, coinbases and transactions depending upon those
// can be duplicated to remove the ability to spend the first instance -- even after
// being sent to another address.
// See BIP30 and http://r6.ca/blog/20120206T005236Z.html for more information.
// This logic is not necessary for memory pool transactions, as AcceptToMemoryPool
// already refuses previously-known transaction ids entirely.
// This rule was originally applied all blocks whose timestamp was 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 in their
// initial block download.
bool fEnforceBIP30 = (!pindex->phashBlock) || // Enforce on CreateNewBlock invocations which don't have a hash.
!((pindex->nHeight==91842 && pindex->GetBlockHash() == uint256("0x00000000000a4d0a398161ffc163c503763b1f4360639393e0e4c8e300e0caec")) ||
(pindex->nHeight==91880 && pindex->GetBlockHash() == uint256("0x00000000000743f190a18c5577a3c2d2a1f610ae9601ac046a38084ccb7cd721")));
if (fEnforceBIP30) {
BOOST_FOREACH(const CTransaction& tx, block.vtx) {
const CCoins* coins = view.AccessCoins(tx.GetHash());
if (coins && !coins->IsPruned())
return state.DoS(100, error("ConnectBlock() : tried to overwrite transaction"),
REJECT_INVALID, "bad-txns-BIP30");
}
}
// BIP16 didn't become active until Apr 1 2012
int64_t nBIP16SwitchTime = 1333238400;
bool fStrictPayToScriptHash = (pindex->GetBlockTime() >= nBIP16SwitchTime);
unsigned int flags = fStrictPayToScriptHash ? SCRIPT_VERIFY_P2SH : SCRIPT_VERIFY_NONE;
CBlockUndo blockundo;
CCheckQueueControl<CScriptCheck> control(fScriptChecks && nScriptCheckThreads ? &scriptcheckqueue : NULL);
int64_t nTimeStart = GetTimeMicros();
CAmount nFees = 0;
int nInputs = 0;
unsigned int nSigOps = 0;
CDiskTxPos pos(pindex->GetBlockPos(), GetSizeOfCompactSize(block.vtx.size()));
std::vector<std::pair<uint256, CDiskTxPos> > vPos;
vPos.reserve(block.vtx.size());
blockundo.vtxundo.reserve(block.vtx.size() - 1);
for (unsigned int i = 0; i < block.vtx.size(); i++)
{
const CTransaction &tx = block.vtx[i];
nInputs += tx.vin.size();
nSigOps += GetLegacySigOpCount(tx);
if (nSigOps > MAX_BLOCK_SIGOPS)
return state.DoS(100, error("ConnectBlock() : too many sigops"),
REJECT_INVALID, "bad-blk-sigops");
if (!tx.IsCoinBase())
{
if (!view.HaveInputs(tx))
return state.DoS(100, error("ConnectBlock() : inputs missing/spent"),
REJECT_INVALID, "bad-txns-inputs-missingorspent");
if (fStrictPayToScriptHash)
{
// Add in sigops done by pay-to-script-hash inputs;
// this is to prevent a "rogue miner" from creating
// an incredibly-expensive-to-validate block.
nSigOps += GetP2SHSigOpCount(tx, view);
if (nSigOps > MAX_BLOCK_SIGOPS)
return state.DoS(100, error("ConnectBlock() : too many sigops"),
REJECT_INVALID, "bad-blk-sigops");
}
nFees += view.GetValueIn(tx)-tx.GetValueOut();
std::vector<CScriptCheck> vChecks;
if (!CheckInputs(tx, state, view, fScriptChecks, flags, false, nScriptCheckThreads ? &vChecks : NULL))
return false;
control.Add(vChecks);
}
CTxUndo undoDummy;
if (i > 0) {
blockundo.vtxundo.push_back(CTxUndo());
}
UpdateCoins(tx, state, view, i == 0 ? undoDummy : blockundo.vtxundo.back(), pindex->nHeight);
vPos.push_back(std::make_pair(tx.GetHash(), pos));
pos.nTxOffset += ::GetSerializeSize(tx, SER_DISK, CLIENT_VERSION);
}
int64_t nTime1 = GetTimeMicros(); nTimeConnect += nTime1 - nTimeStart;
LogPrint("bench", " - Connect %u transactions: %.2fms (%.3fms/tx, %.3fms/txin) [%.2fs]\n", (unsigned)block.vtx.size(), 0.001 * (nTime1 - nTimeStart), 0.001 * (nTime1 - nTimeStart) / block.vtx.size(), nInputs <= 1 ? 0 : 0.001 * (nTime1 - nTimeStart) / (nInputs-1), nTimeConnect * 0.000001);
if (block.vtx[0].GetValueOut() > GetBlockValue(pindex->nHeight, nFees))
return state.DoS(100,
error("ConnectBlock() : coinbase pays too much (actual=%d vs limit=%d)",
block.vtx[0].GetValueOut(), GetBlockValue(pindex->nHeight, nFees)),
REJECT_INVALID, "bad-cb-amount");
if (!control.Wait())
return state.DoS(100, false);
int64_t nTime2 = GetTimeMicros(); nTimeVerify += nTime2 - nTimeStart;
LogPrint("bench", " - Verify %u txins: %.2fms (%.3fms/txin) [%.2fs]\n", nInputs - 1, 0.001 * (nTime2 - nTimeStart), nInputs <= 1 ? 0 : 0.001 * (nTime2 - nTimeStart) / (nInputs-1), nTimeVerify * 0.000001);
if (fJustCheck)
return true;
// Correct transaction counts.
pindex->nTx = block.vtx.size();
if (pindex->pprev)
pindex->nChainTx = pindex->pprev->nChainTx + block.vtx.size();
// Write undo information to disk
if (pindex->GetUndoPos().IsNull() || !pindex->IsValid(BLOCK_VALID_SCRIPTS))
{
if (pindex->GetUndoPos().IsNull()) {
CDiskBlockPos pos;
if (!FindUndoPos(state, pindex->nFile, pos, ::GetSerializeSize(blockundo, SER_DISK, CLIENT_VERSION) + 40))
return error("ConnectBlock() : FindUndoPos failed");
if (!blockundo.WriteToDisk(pos, pindex->pprev->GetBlockHash()))
return state.Abort("Failed to write undo data");
// update nUndoPos in block index
pindex->nUndoPos = pos.nPos;
pindex->nStatus |= BLOCK_HAVE_UNDO;
}
pindex->RaiseValidity(BLOCK_VALID_SCRIPTS);
CDiskBlockIndex blockindex(pindex);
if (!pblocktree->WriteBlockIndex(blockindex))
return state.Abort("Failed to write block index");
}
if (fTxIndex)
if (!pblocktree->WriteTxIndex(vPos))
return state.Abort("Failed to write transaction index");
// add this block to the view's block chain
bool ret;
ret = view.SetBestBlock(pindex->GetBlockHash());
assert(ret);
int64_t nTime3 = GetTimeMicros(); nTimeIndex += nTime3 - nTime2;
LogPrint("bench", " - Index writing: %.2fms [%.2fs]\n", 0.001 * (nTime3 - nTime2), nTimeIndex * 0.000001);
// Watch for changes to the previous coinbase transaction.
static uint256 hashPrevBestCoinBase;
g_signals.UpdatedTransaction(hashPrevBestCoinBase);
hashPrevBestCoinBase = block.vtx[0].GetHash();
int64_t nTime4 = GetTimeMicros(); nTimeCallbacks += nTime4 - nTime3;
LogPrint("bench", " - Callbacks: %.2fms [%.2fs]\n", 0.001 * (nTime4 - nTime3), nTimeCallbacks * 0.000001);
return true;
}
// Update the on-disk chain state.
bool static WriteChainState(CValidationState &state) {
static int64_t nLastWrite = 0;
if (pcoinsTip->GetCacheSize() > nCoinCacheSize || (!IsInitialBlockDownload() && GetTimeMicros() > nLastWrite + 600*1000000)) {
// Typical CCoins structures on disk are around 100 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(100 * 2 * 2 * pcoinsTip->GetCacheSize()))
return state.Error("out of disk space");
FlushBlockFile();
pblocktree->Sync();
if (!pcoinsTip->Flush())
return state.Abort("Failed to write to coin database");
nLastWrite = GetTimeMicros();
}
return true;
}
// Update chainActive and related internal data structures.
void static UpdateTip(CBlockIndex *pindexNew) {
chainActive.SetTip(pindexNew);
// New best block
nTimeBestReceived = GetTime();
mempool.AddTransactionsUpdated(1);
LogPrintf("UpdateTip: new best=%s height=%d log2_work=%.8g tx=%lu date=%s progress=%f\n",
chainActive.Tip()->GetBlockHash().ToString(), chainActive.Height(), log(chainActive.Tip()->nChainWork.getdouble())/log(2.0), (unsigned long)chainActive.Tip()->nChainTx,
DateTimeStrFormat("%Y-%m-%d %H:%M:%S", chainActive.Tip()->GetBlockTime()),
Checkpoints::GuessVerificationProgress(chainActive.Tip()));
cvBlockChange.notify_all();
// Check the version of the last 100 blocks to see if we need to upgrade:
if (!IsInitialBlockDownload())
{
int nUpgraded = 0;
const CBlockIndex* pindex = chainActive.Tip();
for (int i = 0; i < 100 && pindex != NULL; i++)
{
if (pindex->nVersion > CBlock::CURRENT_VERSION)
++nUpgraded;
pindex = pindex->pprev;
}
if (nUpgraded > 0)
LogPrintf("SetBestChain: %d of last 100 blocks above version %d\n", nUpgraded, (int)CBlock::CURRENT_VERSION);
if (nUpgraded > 100/2)
// strMiscWarning is read by GetWarnings(), called by Qt and the JSON-RPC code to warn the user:
strMiscWarning = _("Warning: This version is obsolete, upgrade required!");
}
}
// Disconnect chainActive's tip.
bool static DisconnectTip(CValidationState &state) {
CBlockIndex *pindexDelete = chainActive.Tip();
assert(pindexDelete);
mempool.check(pcoinsTip);
// Read block from disk.
CBlock block;
if (!ReadBlockFromDisk(block, pindexDelete))
return state.Abort("Failed to read block");
// Apply the block atomically to the chain state.
int64_t nStart = GetTimeMicros();
{
CCoinsViewCache view(*pcoinsTip, true);
if (!DisconnectBlock(block, state, pindexDelete, view))
return error("DisconnectTip() : DisconnectBlock %s failed", pindexDelete->GetBlockHash().ToString());
assert(view.Flush());
}
LogPrint("bench", "- Disconnect block: %.2fms\n", (GetTimeMicros() - nStart) * 0.001);
// Write the chain state to disk, if necessary.
if (!WriteChainState(state))
return false;
// Resurrect mempool transactions from the disconnected block.
BOOST_FOREACH(const CTransaction &tx, block.vtx) {
// ignore validation errors in resurrected transactions
list<CTransaction> removed;
CValidationState stateDummy;
if (!tx.IsCoinBase())
if (!AcceptToMemoryPool(mempool, stateDummy, tx, false, NULL))
mempool.remove(tx, removed, true);
}
mempool.check(pcoinsTip);
// Update chainActive and related variables.
UpdateTip(pindexDelete->pprev);
// Let wallets know transactions went from 1-confirmed to
// 0-confirmed or conflicted:
BOOST_FOREACH(const CTransaction &tx, block.vtx) {
SyncWithWallets(tx, NULL);
}
return true;
}
static int64_t nTimeReadFromDisk = 0;
static int64_t nTimeConnectTotal = 0;
static int64_t nTimeFlush = 0;
static int64_t nTimeChainState = 0;
static int64_t nTimePostConnect = 0;
// Connect a new block to chainActive. pblock is either NULL or a pointer to a CBlock
// corresponding to pindexNew, to bypass loading it again from disk.
bool static ConnectTip(CValidationState &state, CBlockIndex *pindexNew, CBlock *pblock) {
assert(pindexNew->pprev == chainActive.Tip());
mempool.check(pcoinsTip);
// Read block from disk.
int64_t nTime1 = GetTimeMicros();
CBlock block;
if (!pblock) {
if (!ReadBlockFromDisk(block, pindexNew))
return state.Abort("Failed to read block");
pblock = &block;
}
// Apply the block atomically to the chain state.
int64_t nTime2 = GetTimeMicros(); nTimeReadFromDisk += nTime2 - nTime1;
int64_t nTime3;
LogPrint("bench", " - Load block from disk: %.2fms [%.2fs]\n", (nTime2 - nTime1) * 0.001, nTimeReadFromDisk * 0.000001);
{
CCoinsViewCache view(*pcoinsTip, true);
CInv inv(MSG_BLOCK, pindexNew->GetBlockHash());
if (!ConnectBlock(*pblock, state, pindexNew, view)) {
if (state.IsInvalid())
InvalidBlockFound(pindexNew, state);
return error("ConnectTip() : ConnectBlock %s failed", pindexNew->GetBlockHash().ToString());
}
mapBlockSource.erase(inv.hash);
nTime3 = GetTimeMicros(); nTimeConnectTotal += nTime3 - nTime2;
LogPrint("bench", " - Connect total: %.2fms [%.2fs]\n", (nTime3 - nTime2) * 0.001, nTimeConnectTotal * 0.000001);
assert(view.Flush());
}
int64_t nTime4 = GetTimeMicros(); nTimeFlush += nTime4 - nTime3;
LogPrint("bench", " - Flush: %.2fms [%.2fs]\n", (nTime4 - nTime3) * 0.001, nTimeFlush * 0.000001);
// Write the chain state to disk, if necessary.
if (!WriteChainState(state))
return false;
int64_t nTime5 = GetTimeMicros(); nTimeChainState += nTime5 - nTime4;
LogPrint("bench", " - Writing chainstate: %.2fms [%.2fs]\n", (nTime5 - nTime4) * 0.001, nTimeChainState * 0.000001);
// Remove conflicting transactions from the mempool.
list<CTransaction> txConflicted;
mempool.removeForBlock(pblock->vtx, pindexNew->nHeight, txConflicted);
mempool.check(pcoinsTip);
// Update chainActive & related variables.
UpdateTip(pindexNew);
// Tell wallet about transactions that went from mempool
// to conflicted:
BOOST_FOREACH(const CTransaction &tx, txConflicted) {
SyncWithWallets(tx, NULL);
}
// ... and about transactions that got confirmed:
BOOST_FOREACH(const CTransaction &tx, pblock->vtx) {
SyncWithWallets(tx, pblock);
}
// Update best block in wallet (so we can detect restored wallets)
// Emit this signal after the SyncWithWallets signals as the wallet relies on that everything up to this point has been synced
if ((chainActive.Height() % 20160) == 0 || ((chainActive.Height() % 144) == 0 && !IsInitialBlockDownload()))
g_signals.SetBestChain(chainActive.GetLocator());
int64_t nTime6 = GetTimeMicros(); nTimePostConnect += nTime6 - nTime5; nTimeTotal += nTime6 - nTime1;
LogPrint("bench", " - Connect postprocess: %.2fms [%.2fs]\n", (nTime6 - nTime5) * 0.001, nTimePostConnect * 0.000001);
LogPrint("bench", "- Connect block: %.2fms [%.2fs]\n", (nTime6 - nTime1) * 0.001, nTimeTotal * 0.000001);
return true;
}
// Return the tip of the chain with the most work in it, that isn't
// known to be invalid (it's however far from certain to be valid).
static CBlockIndex* FindMostWorkChain() {
do {
CBlockIndex *pindexNew = NULL;
// Find the best candidate header.
{
std::set<CBlockIndex*, CBlockIndexWorkComparator>::reverse_iterator it = setBlockIndexValid.rbegin();
if (it == setBlockIndexValid.rend())
return NULL;
pindexNew = *it;
}
// Check whether all blocks on the path between the currently active chain and the candidate are valid.
// Just going until the active chain is an optimization, as we know all blocks in it are valid already.
CBlockIndex *pindexTest = pindexNew;
bool fInvalidAncestor = false;
while (pindexTest && !chainActive.Contains(pindexTest)) {
if (pindexTest->nStatus & BLOCK_FAILED_MASK) {
// Candidate has an invalid ancestor, remove entire chain from the set.
if (pindexBestInvalid == NULL || pindexNew->nChainWork > pindexBestInvalid->nChainWork)
pindexBestInvalid = pindexNew;
CBlockIndex *pindexFailed = pindexNew;
while (pindexTest != pindexFailed) {
pindexFailed->nStatus |= BLOCK_FAILED_CHILD;
setBlockIndexValid.erase(pindexFailed);
pindexFailed = pindexFailed->pprev;
}
setBlockIndexValid.erase(pindexTest);
fInvalidAncestor = true;
break;
}
pindexTest = pindexTest->pprev;
}
if (!fInvalidAncestor)
return pindexNew;
} while(true);
}
// Try to make some progress towards making pindexMostWork the active block.
// pblock is either NULL or a pointer to a CBlock corresponding to pindexMostWork.
static bool ActivateBestChainStep(CValidationState &state, CBlockIndex *pindexMostWork, CBlock *pblock) {
AssertLockHeld(cs_main);
bool fInvalidFound = false;
const CBlockIndex *pindexOldTip = chainActive.Tip();
const CBlockIndex *pindexFork = chainActive.FindFork(pindexMostWork);
// Disconnect active blocks which are no longer in the best chain.
while (chainActive.Tip() && chainActive.Tip() != pindexFork) {
if (!DisconnectTip(state))
return false;
}
// Build list of new blocks to connect.
std::vector<CBlockIndex*> vpindexToConnect;
vpindexToConnect.reserve(pindexMostWork->nHeight - (pindexFork ? pindexFork->nHeight : -1));
CBlockIndex *pindexIter = pindexMostWork;
while (pindexIter && pindexIter != pindexFork) {
vpindexToConnect.push_back(pindexIter);
pindexIter = pindexIter->pprev;
}
// Connect new blocks.
BOOST_REVERSE_FOREACH(CBlockIndex *pindexConnect, vpindexToConnect) {
if (!ConnectTip(state, pindexConnect, pindexConnect == pindexMostWork ? pblock : NULL)) {
if (state.IsInvalid()) {
// The block violates a consensus rule.
if (!state.CorruptionPossible())
InvalidChainFound(vpindexToConnect.back());
state = CValidationState();
fInvalidFound = true;
break;
} else {
// A system error occurred (disk space, database error, ...).
return false;
}
} else {
// Delete all entries in setBlockIndexValid that are worse than our new current block.
// 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 = setBlockIndexValid.begin();
while (setBlockIndexValid.value_comp()(*it, chainActive.Tip())) {
setBlockIndexValid.erase(it++);
}
// Either the current tip or a successor of it we're working towards is left in setBlockIndexValid.
assert(!setBlockIndexValid.empty());
if (!pindexOldTip || chainActive.Tip()->nChainWork > pindexOldTip->nChainWork) {
// We're in a better position than we were. Return temporarily to release the lock.
break;
}
}
}
// Callbacks/notifications for a new best chain.
if (fInvalidFound)
CheckForkWarningConditionsOnNewFork(vpindexToConnect.back());
else
CheckForkWarningConditions();
if (!pblocktree->Flush())
return state.Abort("Failed to sync block index");
return true;
}
// Make the best chain active, in multiple steps. The result is either failure
// or an activated best chain. pblock is either NULL or a pointer to a block
// that is already loaded (to avoid loading it again from disk).
bool ActivateBestChain(CValidationState &state, CBlock *pblock) {
CBlockIndex *pindexNewTip = NULL;
CBlockIndex *pindexMostWork = NULL;
do {
boost::this_thread::interruption_point();
bool fInitialDownload;
{
LOCK(cs_main);
pindexMostWork = FindMostWorkChain();
// Whether we have anything to do at all.
if (pindexMostWork == NULL || pindexMostWork == chainActive.Tip())
return true;
if (!ActivateBestChainStep(state, pindexMostWork, pblock && pblock->GetHash() == pindexMostWork->GetBlockHash() ? pblock : NULL))
return false;
pindexNewTip = chainActive.Tip();
fInitialDownload = IsInitialBlockDownload();
}
// When we reach this point, we switched to a new tip (stored in pindexNewTip).
// Notifications/callbacks that can run without cs_main
if (!fInitialDownload) {
uint256 hashNewTip = pindexNewTip->GetBlockHash();
// Relay inventory, but don't relay old inventory during initial block download.
int nBlockEstimate = Checkpoints::GetTotalBlocksEstimate();
{
LOCK(cs_vNodes);
BOOST_FOREACH(CNode* pnode, vNodes)
if (chainActive.Height() > (pnode->nStartingHeight != -1 ? pnode->nStartingHeight - 2000 : nBlockEstimate))
pnode->PushInventory(CInv(MSG_BLOCK, hashNewTip));
}
uiInterface.NotifyBlockTip(hashNewTip);
}
} while(pindexMostWork != chainActive.Tip());
return true;
}
CBlockIndex* AddToBlockIndex(CBlockHeader& block)
{
// Check for duplicate
uint256 hash = block.GetHash();
BlockMap::iterator it = mapBlockIndex.find(hash);
if (it != mapBlockIndex.end())
return it->second;
// Construct new block index object
CBlockIndex* pindexNew = new CBlockIndex(block);
assert(pindexNew);
{
LOCK(cs_nBlockSequenceId);
pindexNew->nSequenceId = nBlockSequenceId++;
}
BlockMap::iterator mi = mapBlockIndex.insert(make_pair(hash, pindexNew)).first;
pindexNew->phashBlock = &((*mi).first);
BlockMap::iterator miPrev = mapBlockIndex.find(block.hashPrevBlock);
if (miPrev != mapBlockIndex.end())
{
pindexNew->pprev = (*miPrev).second;
pindexNew->nHeight = pindexNew->pprev->nHeight + 1;
pindexNew->BuildSkip();
}
pindexNew->nChainWork = (pindexNew->pprev ? pindexNew->pprev->nChainWork : 0) + pindexNew->GetBlockWork();
pindexNew->RaiseValidity(BLOCK_VALID_TREE);
return pindexNew;
}
// Mark a block as having its data received and checked (up to BLOCK_VALID_TRANSACTIONS).
bool ReceivedBlockTransactions(const CBlock &block, CValidationState& state, CBlockIndex *pindexNew, const CDiskBlockPos& pos)
{
pindexNew->nTx = block.vtx.size();
if (pindexNew->pprev) {
// Not the genesis block.
if (pindexNew->pprev->nChainTx) {
// This parent's block's total number transactions is known, so compute outs.
pindexNew->nChainTx = pindexNew->pprev->nChainTx + pindexNew->nTx;
} else {
// The total number of transactions isn't known yet.
// We will compute it when the block is connected.
pindexNew->nChainTx = 0;
}
} else {
// Genesis block.
pindexNew->nChainTx = pindexNew->nTx;
}
pindexNew->nFile = pos.nFile;
pindexNew->nDataPos = pos.nPos;
pindexNew->nUndoPos = 0;
pindexNew->nStatus |= BLOCK_HAVE_DATA;
if (pindexNew->RaiseValidity(BLOCK_VALID_TRANSACTIONS))
setBlockIndexValid.insert(pindexNew);
if (!pblocktree->WriteBlockIndex(CDiskBlockIndex(pindexNew)))
return state.Abort("Failed to write block index");
return true;
}
bool FindBlockPos(CValidationState &state, CDiskBlockPos &pos, unsigned int nAddSize, unsigned int nHeight, uint64_t nTime, bool fKnown = false)
{
bool fUpdatedLast = false;
LOCK(cs_LastBlockFile);
if (fKnown) {
if (nLastBlockFile != pos.nFile) {
nLastBlockFile = pos.nFile;
infoLastBlockFile.SetNull();
pblocktree->ReadBlockFileInfo(nLastBlockFile, infoLastBlockFile);
fUpdatedLast = true;
}
} else {
while (infoLastBlockFile.nSize + nAddSize >= MAX_BLOCKFILE_SIZE) {
LogPrintf("Leaving block file %i: %s\n", nLastBlockFile, infoLastBlockFile.ToString());
FlushBlockFile(true);
nLastBlockFile++;
infoLastBlockFile.SetNull();
pblocktree->ReadBlockFileInfo(nLastBlockFile, infoLastBlockFile); // check whether data for the new file somehow already exist; can fail just fine
fUpdatedLast = true;
}
pos.nFile = nLastBlockFile;
pos.nPos = infoLastBlockFile.nSize;
}
infoLastBlockFile.nSize += nAddSize;
infoLastBlockFile.AddBlock(nHeight, nTime);
if (!fKnown) {
unsigned int nOldChunks = (pos.nPos + BLOCKFILE_CHUNK_SIZE - 1) / BLOCKFILE_CHUNK_SIZE;
unsigned int nNewChunks = (infoLastBlockFile.nSize + BLOCKFILE_CHUNK_SIZE - 1) / BLOCKFILE_CHUNK_SIZE;
if (nNewChunks > nOldChunks) {
if (CheckDiskSpace(nNewChunks * BLOCKFILE_CHUNK_SIZE - pos.nPos)) {
FILE *file = OpenBlockFile(pos);
if (file) {
LogPrintf("Pre-allocating up to position 0x%x in blk%05u.dat\n", nNewChunks * BLOCKFILE_CHUNK_SIZE, pos.nFile);
AllocateFileRange(file, pos.nPos, nNewChunks * BLOCKFILE_CHUNK_SIZE - pos.nPos);
fclose(file);
}
}
else
return state.Error("out of disk space");
}
}
if (!pblocktree->WriteBlockFileInfo(nLastBlockFile, infoLastBlockFile))
return state.Abort("Failed to write file info");
if (fUpdatedLast)
pblocktree->WriteLastBlockFile(nLastBlockFile);
return true;
}
bool FindUndoPos(CValidationState &state, int nFile, CDiskBlockPos &pos, unsigned int nAddSize)
{
pos.nFile = nFile;
LOCK(cs_LastBlockFile);
unsigned int nNewSize;
if (nFile == nLastBlockFile) {
pos.nPos = infoLastBlockFile.nUndoSize;
nNewSize = (infoLastBlockFile.nUndoSize += nAddSize);
if (!pblocktree->WriteBlockFileInfo(nLastBlockFile, infoLastBlockFile))
return state.Abort("Failed to write block info");
} else {
CBlockFileInfo info;
if (!pblocktree->ReadBlockFileInfo(nFile, info))
return state.Abort("Failed to read block info");
pos.nPos = info.nUndoSize;
nNewSize = (info.nUndoSize += nAddSize);
if (!pblocktree->WriteBlockFileInfo(nFile, info))
return state.Abort("Failed to write block info");
}
unsigned int nOldChunks = (pos.nPos + UNDOFILE_CHUNK_SIZE - 1) / UNDOFILE_CHUNK_SIZE;
unsigned int nNewChunks = (nNewSize + UNDOFILE_CHUNK_SIZE - 1) / UNDOFILE_CHUNK_SIZE;
if (nNewChunks > nOldChunks) {
if (CheckDiskSpace(nNewChunks * UNDOFILE_CHUNK_SIZE - pos.nPos)) {
FILE *file = OpenUndoFile(pos);
if (file) {
LogPrintf("Pre-allocating up to position 0x%x in rev%05u.dat\n", nNewChunks * UNDOFILE_CHUNK_SIZE, pos.nFile);
AllocateFileRange(file, pos.nPos, nNewChunks * UNDOFILE_CHUNK_SIZE - pos.nPos);
fclose(file);
}
}
else
return state.Error("out of disk space");
}
return true;
}
bool CheckBlockHeader(const CBlockHeader& block, CValidationState& state, bool fCheckPOW)
{
// Check proof of work matches claimed amount
if (fCheckPOW && !CheckProofOfWork(block.GetHash(), block.nBits))
return state.DoS(50, error("CheckBlockHeader() : proof of work failed"),
REJECT_INVALID, "high-hash");
// Check timestamp
if (block.GetBlockTime() > GetAdjustedTime() + 2 * 60 * 60)
return state.Invalid(error("CheckBlockHeader() : block timestamp too far in the future"),
REJECT_INVALID, "time-too-new");
return true;
}
bool CheckBlock(const CBlock& block, CValidationState& state, bool fCheckPOW, bool fCheckMerkleRoot)
{
// These are checks that are independent of context
// that can be verified before saving an orphan block.
if (!CheckBlockHeader(block, state, fCheckPOW))
return false;
// Size limits
if (block.vtx.empty() || block.vtx.size() > MAX_BLOCK_SIZE || ::GetSerializeSize(block, SER_NETWORK, PROTOCOL_VERSION) > MAX_BLOCK_SIZE)
return state.DoS(100, error("CheckBlock() : size limits failed"),
REJECT_INVALID, "bad-blk-length");
// First transaction must be coinbase, the rest must not be
if (block.vtx.empty() || !block.vtx[0].IsCoinBase())
return state.DoS(100, error("CheckBlock() : first tx is not coinbase"),
REJECT_INVALID, "bad-cb-missing");
for (unsigned int i = 1; i < block.vtx.size(); i++)
if (block.vtx[i].IsCoinBase())
return state.DoS(100, error("CheckBlock() : more than one coinbase"),
REJECT_INVALID, "bad-cb-multiple");
// Check transactions
BOOST_FOREACH(const CTransaction& tx, block.vtx)
if (!CheckTransaction(tx, state))
return error("CheckBlock() : CheckTransaction failed");
// 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.
bool mutated;
uint256 hashMerkleRoot2 = block.BuildMerkleTree(&mutated);
if (mutated)
return state.DoS(100, error("CheckBlock() : duplicate transaction"),
REJECT_INVALID, "bad-txns-duplicate", true);
unsigned int nSigOps = 0;
BOOST_FOREACH(const CTransaction& tx, block.vtx)
{
nSigOps += GetLegacySigOpCount(tx);
}
if (nSigOps > MAX_BLOCK_SIGOPS)
return state.DoS(100, error("CheckBlock() : out-of-bounds SigOpCount"),
REJECT_INVALID, "bad-blk-sigops", true);
// Check merkle root
if (fCheckMerkleRoot && block.hashMerkleRoot != hashMerkleRoot2)
return state.DoS(100, error("CheckBlock() : hashMerkleRoot mismatch"),
REJECT_INVALID, "bad-txnmrklroot", true);
return true;
}
bool AcceptBlockHeader(CBlockHeader& block, CValidationState& state, CBlockIndex** ppindex)
{
AssertLockHeld(cs_main);
// Check for duplicate
uint256 hash = block.GetHash();
BlockMap::iterator miSelf = mapBlockIndex.find(hash);
CBlockIndex *pindex = NULL;
if (miSelf != mapBlockIndex.end()) {
pindex = miSelf->second;
if (pindex->nStatus & BLOCK_FAILED_MASK)
return state.Invalid(error("%s : block is marked invalid", __func__), 0, "duplicate");
}
CBlockIndex* pcheckpoint = Checkpoints::GetLastCheckpoint();
if (pcheckpoint && block.hashPrevBlock != (chainActive.Tip() ? chainActive.Tip()->GetBlockHash() : uint256(0)))
{
// Extra checks to prevent "fill up memory by spamming with bogus blocks"
int64_t deltaTime = block.GetBlockTime() - pcheckpoint->GetBlockTime();
if (deltaTime < 0)
{
return state.DoS(100, error("%s : block with timestamp before last checkpoint", __func__),
REJECT_CHECKPOINT, "time-too-old");
}
if (!CheckMinWork(block.nBits, pcheckpoint->nBits, deltaTime))
{
return state.DoS(100, error("%s : block with too little proof-of-work", __func__),
REJECT_INVALID, "bad-diffbits");
}
}
// Get prev block index
CBlockIndex* pindexPrev = NULL;
int nHeight = 0;
if (hash != Params().HashGenesisBlock()) {
BlockMap::iterator mi = mapBlockIndex.find(block.hashPrevBlock);
if (mi == mapBlockIndex.end())
return state.DoS(10, error("%s : prev block not found", __func__), 0, "bad-prevblk");
pindexPrev = (*mi).second;
nHeight = pindexPrev->nHeight+1;
// Check proof of work
if ((!Params().SkipProofOfWorkCheck()) &&
(block.nBits != GetNextWorkRequired(pindexPrev, &block)))
return state.DoS(100, error("%s : incorrect proof of work", __func__),
REJECT_INVALID, "bad-diffbits");
// Check timestamp against prev
if (block.GetBlockTime() <= pindexPrev->GetMedianTimePast())
return state.Invalid(error("%s : block's timestamp is too early", __func__),
REJECT_INVALID, "time-too-old");
// Check that the block chain matches the known block chain up to a checkpoint
if (!Checkpoints::CheckBlock(nHeight, hash))
return state.DoS(100, error("%s : rejected by checkpoint lock-in at %d", __func__, nHeight),
REJECT_CHECKPOINT, "checkpoint mismatch");
// Don't accept any forks from the main chain prior to last checkpoint
CBlockIndex* pcheckpoint = Checkpoints::GetLastCheckpoint();
if (pcheckpoint && nHeight < pcheckpoint->nHeight)
return state.DoS(100, error("%s : forked chain older than last checkpoint (height %d)", __func__, nHeight));
// Reject block.nVersion=1 blocks when 95% (75% on testnet) of the network has upgraded:
if (block.nVersion < 2 &&
CBlockIndex::IsSuperMajority(2, pindexPrev, Params().RejectBlockOutdatedMajority()))
{
return state.Invalid(error("%s : rejected nVersion=1 block", __func__),
REJECT_OBSOLETE, "bad-version");
}
}
if (pindex == NULL)
pindex = AddToBlockIndex(block);
if (ppindex)
*ppindex = pindex;
return true;
}
bool AcceptBlock(CBlock& block, CValidationState& state, CBlockIndex** ppindex, CDiskBlockPos* dbp)
{
AssertLockHeld(cs_main);
CBlockIndex *&pindex = *ppindex;
if (!AcceptBlockHeader(block, state, &pindex))
return false;
if (!CheckBlock(block, state)) {
if (state.IsInvalid() && !state.CorruptionPossible()) {
pindex->nStatus |= BLOCK_FAILED_VALID;
}
return false;
}
int nHeight = pindex->nHeight;
// Check that all transactions are finalized
BOOST_FOREACH(const CTransaction& tx, block.vtx)
if (!IsFinalTx(tx, nHeight, block.GetBlockTime())) {
pindex->nStatus |= BLOCK_FAILED_VALID;
return state.DoS(10, error("AcceptBlock() : contains a non-final transaction"),
REJECT_INVALID, "bad-txns-nonfinal");
}
// Enforce block.nVersion=2 rule that the coinbase starts with serialized block height
// if 750 of the last 1,000 blocks are version 2 or greater (51/100 if testnet):
if (block.nVersion >= 2 &&
CBlockIndex::IsSuperMajority(2, pindex->pprev, Params().EnforceBlockUpgradeMajority()))
{
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())) {
pindex->nStatus |= BLOCK_FAILED_VALID;
return state.DoS(100, error("AcceptBlock() : block height mismatch in coinbase"), REJECT_INVALID, "bad-cb-height");
}
}
// Write block to history file
try {
unsigned int nBlockSize = ::GetSerializeSize(block, SER_DISK, CLIENT_VERSION);
CDiskBlockPos blockPos;
if (dbp != NULL)
blockPos = *dbp;
if (!FindBlockPos(state, blockPos, nBlockSize+8, nHeight, block.GetBlockTime(), dbp != NULL))
return error("AcceptBlock() : FindBlockPos failed");
if (dbp == NULL)
if (!WriteBlockToDisk(block, blockPos))
return state.Abort("Failed to write block");
if (!ReceivedBlockTransactions(block, state, pindex, blockPos))
return error("AcceptBlock() : ReceivedBlockTransactions failed");
} catch(std::runtime_error &e) {
return state.Abort(std::string("System error: ") + e.what());
}
return true;
}
bool CBlockIndex::IsSuperMajority(int minVersion, const CBlockIndex* pstart, unsigned int nRequired)
{
unsigned int nToCheck = Params().ToCheckBlockUpgradeMajority();
unsigned int nFound = 0;
for (unsigned int i = 0; i < nToCheck && nFound < nRequired && pstart != NULL; i++)
{
if (pstart->nVersion >= minVersion)
++nFound;
pstart = pstart->pprev;
}
return (nFound >= nRequired);
}
/** Turn the lowest '1' bit in the binary representation of a number into a '0'. */
int static inline InvertLowestOne(int n) { return n & (n - 1); }
/** Compute what height to jump back to with the CBlockIndex::pskip pointer. */
int static inline GetSkipHeight(int height) {
if (height < 2)
return 0;
// Determine which height to jump back to. Any number strictly lower than height is acceptable,
// but the following expression seems to perform well in simulations (max 110 steps to go back
// up to 2**18 blocks).
return (height & 1) ? InvertLowestOne(InvertLowestOne(height - 1)) + 1 : InvertLowestOne(height);
}
CBlockIndex* CBlockIndex::GetAncestor(int height)
{
if (height > nHeight || height < 0)
return NULL;
CBlockIndex* pindexWalk = this;
int heightWalk = nHeight;
while (heightWalk > height) {
int heightSkip = GetSkipHeight(heightWalk);
int heightSkipPrev = GetSkipHeight(heightWalk - 1);
if (heightSkip == height ||
(heightSkip > height && !(heightSkipPrev < heightSkip - 2 &&
heightSkipPrev >= height))) {
// Only follow pskip if pprev->pskip isn't better than pskip->pprev.
pindexWalk = pindexWalk->pskip;
heightWalk = heightSkip;
} else {
pindexWalk = pindexWalk->pprev;
heightWalk--;
}
}
return pindexWalk;
}
const CBlockIndex* CBlockIndex::GetAncestor(int height) const
{
return const_cast<CBlockIndex*>(this)->GetAncestor(height);
}
void CBlockIndex::BuildSkip()
{
if (pprev)
pskip = pprev->GetAncestor(GetSkipHeight(nHeight));
}
void PushGetBlocks(CNode* pnode, CBlockIndex* pindexBegin, uint256 hashEnd)
{
AssertLockHeld(cs_main);
// Filter out duplicate requests
if (pindexBegin == pnode->pindexLastGetBlocksBegin && hashEnd == pnode->hashLastGetBlocksEnd)
return;
pnode->pindexLastGetBlocksBegin = pindexBegin;
pnode->hashLastGetBlocksEnd = hashEnd;
pnode->PushMessage("getblocks", chainActive.GetLocator(pindexBegin), hashEnd);
}
bool ProcessBlock(CValidationState &state, CNode* pfrom, CBlock* pblock, CDiskBlockPos *dbp)
{
// Check for duplicate
uint256 hash = pblock->GetHash();
{
LOCK(cs_main);
if (mapBlockIndex.count(hash))
return state.Invalid(error("ProcessBlock() : already have block %d %s", mapBlockIndex[hash]->nHeight, hash.ToString()), 0, "duplicate");
if (mapOrphanBlocks.count(hash))
return state.Invalid(error("ProcessBlock() : already have block (orphan) %s", hash.ToString()), 0, "duplicate");
// Preliminary checks
if (!CheckBlock(*pblock, state))
return error("ProcessBlock() : CheckBlock FAILED");
// If we don't already have its previous block (with full data), shunt it off to holding area until we