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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
#if defined(HAVE_CONFIG_H)
#include "config/bitcoin-config.h"
#include "chain.h"
#include "chainparams.h"
#include "coins.h"
#include "core.h"
#include "net.h"
#include "pow.h"
#include "script/script.h"
#include "script/sigcache.h"
#include "script/standard.h"
#include "sync.h"
#include "txmempool.h"
#include "uint256.h"
#include <algorithm>
#include <exception>
#include <map>
#include <set>
#include <stdint.h>
#include <string>
#include <utility>
#include <vector>
#include <boost/unordered_map.hpp>
class CBlockIndex;
class CBloomFilter;
class CInv;
/** The maximum allowed size for a serialized block, in bytes (network rule) */
static const unsigned int MAX_BLOCK_SIZE = 1000000;
/** Default for -blockmaxsize and -blockminsize, which control the range of sizes the mining code will create **/
static const unsigned int DEFAULT_BLOCK_MAX_SIZE = 750000;
static const unsigned int DEFAULT_BLOCK_MIN_SIZE = 0;
/** Default for -blockprioritysize, maximum space for zero/low-fee transactions **/
static const unsigned int DEFAULT_BLOCK_PRIORITY_SIZE = 50000;
/** The maximum size for transactions we're willing to relay/mine */
static const unsigned int MAX_STANDARD_TX_SIZE = 100000;
/** The maximum allowed number of signature check operations in a block (network rule) */
static const unsigned int MAX_BLOCK_SIGOPS = MAX_BLOCK_SIZE/50;
/** Maxiumum number of signature check operations in an IsStandard() P2SH script */
static const unsigned int MAX_P2SH_SIGOPS = 15;
/** The maximum number of sigops we're willing to relay/mine in a single tx */
static const unsigned int MAX_TX_SIGOPS = MAX_BLOCK_SIGOPS/5;
/** Default for -maxorphantx, maximum number of orphan transactions kept in memory */
static const unsigned int DEFAULT_MAX_ORPHAN_TRANSACTIONS = 100;
/** Default for -maxorphanblocks, maximum number of orphan blocks kept in memory */
static const unsigned int DEFAULT_MAX_ORPHAN_BLOCKS = 750;
/** The maximum size of a blk?????.dat file (since 0.8) */
static const unsigned int MAX_BLOCKFILE_SIZE = 0x8000000; // 128 MiB
/** The pre-allocation chunk size for blk?????.dat files (since 0.8) */
static const unsigned int BLOCKFILE_CHUNK_SIZE = 0x1000000; // 16 MiB
/** The pre-allocation chunk size for rev?????.dat files (since 0.8) */
static const unsigned int UNDOFILE_CHUNK_SIZE = 0x100000; // 1 MiB
/** Coinbase transaction outputs can only be spent after this number of new blocks (network rule) */
static const int COINBASE_MATURITY = 100;
/** Threshold for nLockTime: below this value it is interpreted as block number, otherwise as UNIX timestamp. */
static const unsigned int LOCKTIME_THRESHOLD = 500000000; // Tue Nov 5 00:53:20 1985 UTC
/** Maximum number of script-checking threads allowed */
static const int MAX_SCRIPTCHECK_THREADS = 16;
/** -par default (number of script-checking threads, 0 = auto) */
/** Number of blocks that can be requested at any given time from a single peer. */
static const int MAX_BLOCKS_IN_TRANSIT_PER_PEER = 128;
/** Timeout in seconds before considering a block download peer unresponsive. */
static const unsigned int BLOCK_DOWNLOAD_TIMEOUT = 60;
/** "reject" message codes **/
static const unsigned char REJECT_MALFORMED = 0x01;
static const unsigned char REJECT_INVALID = 0x10;
static const unsigned char REJECT_OBSOLETE = 0x11;
static const unsigned char REJECT_DUPLICATE = 0x12;
static const unsigned char REJECT_NONSTANDARD = 0x40;
static const unsigned char REJECT_DUST = 0x41;
static const unsigned char REJECT_INSUFFICIENTFEE = 0x42;
static const unsigned char REJECT_CHECKPOINT = 0x43;
struct BlockHasher
size_t operator()(const uint256& hash) const { return hash.GetLow64(); }
extern CScript COINBASE_FLAGS;
extern CCriticalSection cs_main;
extern CTxMemPool mempool;
typedef boost::unordered_map<uint256, CBlockIndex*, BlockHasher> BlockMap;
extern BlockMap mapBlockIndex;
extern uint64_t nLastBlockTx;
extern uint64_t nLastBlockSize;
extern const std::string strMessageMagic;
extern int64_t nTimeBestReceived;
extern CWaitableCriticalSection csBestBlock;
extern CConditionVariable cvBlockChange;
extern bool fImporting;
extern bool fReindex;
extern int nScriptCheckThreads;
extern bool fTxIndex;
extern bool fIsBareMultisigStd;
extern unsigned int nCoinCacheSize;
extern CFeeRate minRelayTxFee;
// Minimum disk space required - used in CheckDiskSpace()
static const uint64_t nMinDiskSpace = 52428800;
class CBlockTreeDB;
class CTxUndo;
class CScriptCheck;
class CValidationState;
class CWalletInterface;
struct CNodeStateStats;
struct CBlockTemplate;
/** Register a wallet to receive updates from core */
void RegisterWallet(CWalletInterface* pwalletIn);
/** Unregister a wallet from core */
void UnregisterWallet(CWalletInterface* pwalletIn);
/** Unregister all wallets from core */
void UnregisterAllWallets();
/** Push an updated transaction to all registered wallets */
void SyncWithWallets(const CTransaction& tx, const CBlock* pblock = NULL);
/** Register with a network node to receive its signals */
void RegisterNodeSignals(CNodeSignals& nodeSignals);
/** Unregister a network node */
void UnregisterNodeSignals(CNodeSignals& nodeSignals);
void PushGetBlocks(CNode* pnode, CBlockIndex* pindexBegin, uint256 hashEnd);
/** Process an incoming block */
bool ProcessBlock(CValidationState &state, CNode* pfrom, CBlock* pblock, CDiskBlockPos *dbp = NULL);
/** Check whether enough disk space is available for an incoming block */
bool CheckDiskSpace(uint64_t nAdditionalBytes = 0);
/** Open a block file (blk?????.dat) */
FILE* OpenBlockFile(const CDiskBlockPos &pos, bool fReadOnly = false);
/** Open an undo file (rev?????.dat) */
FILE* OpenUndoFile(const CDiskBlockPos &pos, bool fReadOnly = false);
/** Translation to a filesystem path */
boost::filesystem::path GetBlockPosFilename(const CDiskBlockPos &pos, const char *prefix);
/** Import blocks from an external file */
bool LoadExternalBlockFile(FILE* fileIn, CDiskBlockPos *dbp = NULL);
/** Initialize a new block tree database + block data on disk */
bool InitBlockIndex();
/** Load the block tree and coins database from disk */
bool LoadBlockIndex();
/** Unload database information */
void UnloadBlockIndex();
/** Print the loaded block tree */
void PrintBlockTree();
/** Process protocol messages received from a given node */
bool ProcessMessages(CNode* pfrom);
/** Send queued protocol messages to be sent to a give node */
bool SendMessages(CNode* pto, bool fSendTrickle);
/** Run an instance of the script checking thread */
void ThreadScriptCheck();
/** Check whether we are doing an initial block download (synchronizing from disk or network) */
bool IsInitialBlockDownload();
/** Format a string that describes several potential problems detected by the core */
std::string GetWarnings(std::string strFor);
/** Retrieve a transaction (from memory pool, or from disk, if possible) */
bool GetTransaction(const uint256 &hash, CTransaction &tx, uint256 &hashBlock, bool fAllowSlow = false);
/** Find the best known block, and make it the tip of the block chain */
bool ActivateBestChain(CValidationState &state, CBlock *pblock = NULL);
CAmount GetBlockValue(int nHeight, const CAmount& nFees);
/** Create a new block index entry for a given block hash */
CBlockIndex * InsertBlockIndex(uint256 hash);
/** Abort with a message */
bool AbortNode(const std::string &msg, const std::string &userMessage="");
/** Get statistics from node state */
bool GetNodeStateStats(NodeId nodeid, CNodeStateStats &stats);
/** Increase a node's misbehavior score. */
void Misbehaving(NodeId nodeid, int howmuch);
/** (try to) add transaction to memory pool **/
bool AcceptToMemoryPool(CTxMemPool& pool, CValidationState &state, const CTransaction &tx, bool fLimitFree,
bool* pfMissingInputs, bool fRejectInsaneFee=false);
struct CNodeStateStats {
int nMisbehavior;
int nSyncHeight;
struct CDiskTxPos : public CDiskBlockPos
unsigned int nTxOffset; // after header
template <typename Stream, typename Operation>
inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
CDiskTxPos(const CDiskBlockPos &blockIn, unsigned int nTxOffsetIn) : CDiskBlockPos(blockIn.nFile, blockIn.nPos), nTxOffset(nTxOffsetIn) {
CDiskTxPos() {
void SetNull() {
nTxOffset = 0;
CAmount GetMinRelayFee(const CTransaction& tx, unsigned int nBytes, bool fAllowFree);
// Check transaction inputs, and make sure any
// pay-to-script-hash transactions are evaluating IsStandard scripts
// Why bother? To avoid denial-of-service attacks; an attacker
// can submit a standard HASH... OP_EQUAL transaction,
// which will get accepted into blocks. The redemption
// script can be anything; an attacker could use a very
// expensive-to-check-upon-redemption script like:
// DUP CHECKSIG DROP ... repeated 100 times... OP_1
/** Check for standard transaction types
@param[in] mapInputs Map of previous transactions that have outputs we're spending
@return True if all inputs (scriptSigs) use only standard transaction forms
bool AreInputsStandard(const CTransaction& tx, const CCoinsViewCache& mapInputs);
/** Count ECDSA signature operations the old-fashioned (pre-0.6) way
@return number of sigops this transaction's outputs will produce when spent
@see CTransaction::FetchInputs
unsigned int GetLegacySigOpCount(const CTransaction& tx);
/** Count ECDSA signature operations in pay-to-script-hash inputs.
@param[in] mapInputs Map of previous transactions that have outputs we're spending
@return maximum number of sigops required to validate this transaction's inputs
@see CTransaction::FetchInputs
unsigned int GetP2SHSigOpCount(const CTransaction& tx, const CCoinsViewCache& mapInputs);
// Check whether all inputs of this transaction are valid (no double spends, scripts & sigs, amounts)
// This does not modify the UTXO set. If pvChecks is not NULL, script checks are pushed onto it
// instead of being performed inline.
bool CheckInputs(const CTransaction& tx, CValidationState &state, const CCoinsViewCache &view, bool fScriptChecks,
unsigned int flags, bool cacheStore, std::vector<CScriptCheck> *pvChecks = NULL);
// Apply the effects of this transaction on the UTXO set represented by view
void UpdateCoins(const CTransaction& tx, CValidationState &state, CCoinsViewCache &inputs, CTxUndo &txundo, int nHeight);
// Context-independent validity checks
bool CheckTransaction(const CTransaction& tx, CValidationState& state);
/** Check for standard transaction types
@return True if all outputs (scriptPubKeys) use only standard transaction forms
bool IsStandardTx(const CTransaction& tx, std::string& reason);
bool IsFinalTx(const CTransaction &tx, int nBlockHeight = 0, int64_t nBlockTime = 0);
/** Undo information for a CBlock */
class CBlockUndo
std::vector<CTxUndo> vtxundo; // for all but the coinbase
template <typename Stream, typename Operation>
inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
bool WriteToDisk(CDiskBlockPos &pos, const uint256 &hashBlock);
bool ReadFromDisk(const CDiskBlockPos &pos, const uint256 &hashBlock);
/** Closure representing one script verification
* Note that this stores references to the spending transaction */
class CScriptCheck
CScript scriptPubKey;
const CTransaction *ptxTo;
unsigned int nIn;
unsigned int nFlags;
bool cacheStore;
CScriptCheck(): ptxTo(0), nIn(0), nFlags(0), cacheStore(false) {}
CScriptCheck(const CCoins& txFromIn, const CTransaction& txToIn, unsigned int nInIn, unsigned int nFlagsIn, bool cacheIn) :
ptxTo(&txToIn), nIn(nInIn), nFlags(nFlagsIn), cacheStore(cacheIn) { }
bool operator()() const;
void swap(CScriptCheck &check) {
std::swap(ptxTo, check.ptxTo);
std::swap(nIn, check.nIn);
std::swap(nFlags, check.nFlags);
std::swap(cacheStore, check.cacheStore);
/** Data structure that represents a partial merkle tree.
* It respresents a subset of the txid's of a known block, in a way that
* allows recovery of the list of txid's and the merkle root, in an
* authenticated way.
* The encoding works as follows: we traverse the tree in depth-first order,
* storing a bit for each traversed node, signifying whether the node is the
* parent of at least one matched leaf txid (or a matched txid itself). In
* case we are at the leaf level, or this bit is 0, its merkle node hash is
* stored, and its children are not explorer further. Otherwise, no hash is
* stored, but we recurse into both (or the only) child branch. During
* decoding, the same depth-first traversal is performed, consuming bits and
* hashes as they written during encoding.
* The serialization is fixed and provides a hard guarantee about the
* encoded size:
* SIZE <= 10 + ceil(32.25*N)
* Where N represents the number of leaf nodes of the partial tree. N itself
* is bounded by:
* N <= total_transactions
* N <= 1 + matched_transactions*tree_height
* The serialization format:
* - uint32 total_transactions (4 bytes)
* - varint number of hashes (1-3 bytes)
* - uint256[] hashes in depth-first order (<= 32*N bytes)
* - varint number of bytes of flag bits (1-3 bytes)
* - byte[] flag bits, packed per 8 in a byte, least significant bit first (<= 2*N-1 bits)
* The size constraints follow from this.
class CPartialMerkleTree
// the total number of transactions in the block
unsigned int nTransactions;
// node-is-parent-of-matched-txid bits
std::vector<bool> vBits;
// txids and internal hashes
std::vector<uint256> vHash;
// flag set when encountering invalid data
bool fBad;
// helper function to efficiently calculate the number of nodes at given height in the merkle tree
unsigned int CalcTreeWidth(int height) {
return (nTransactions+(1 << height)-1) >> height;
// calculate the hash of a node in the merkle tree (at leaf level: the txid's themself)
uint256 CalcHash(int height, unsigned int pos, const std::vector<uint256> &vTxid);
// recursive function that traverses tree nodes, storing the data as bits and hashes
void TraverseAndBuild(int height, unsigned int pos, const std::vector<uint256> &vTxid, const std::vector<bool> &vMatch);
// recursive function that traverses tree nodes, consuming the bits and hashes produced by TraverseAndBuild.
// it returns the hash of the respective node.
uint256 TraverseAndExtract(int height, unsigned int pos, unsigned int &nBitsUsed, unsigned int &nHashUsed, std::vector<uint256> &vMatch);
// serialization implementation
template <typename Stream, typename Operation>
inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
std::vector<unsigned char> vBytes;
if (ser_action.ForRead()) {
CPartialMerkleTree &us = *(const_cast<CPartialMerkleTree*>(this));
us.vBits.resize(vBytes.size() * 8);
for (unsigned int p = 0; p < us.vBits.size(); p++)
us.vBits[p] = (vBytes[p / 8] & (1 << (p % 8))) != 0;
us.fBad = false;
} else {
for (unsigned int p = 0; p < vBits.size(); p++)
vBytes[p / 8] |= vBits[p] << (p % 8);
// Construct a partial merkle tree from a list of transaction id's, and a mask that selects a subset of them
CPartialMerkleTree(const std::vector<uint256> &vTxid, const std::vector<bool> &vMatch);
// extract the matching txid's represented by this partial merkle tree.
// returns the merkle root, or 0 in case of failure
uint256 ExtractMatches(std::vector<uint256> &vMatch);
/** Functions for disk access for blocks */
bool WriteBlockToDisk(CBlock& block, CDiskBlockPos& pos);
bool ReadBlockFromDisk(CBlock& block, const CDiskBlockPos& pos);
bool ReadBlockFromDisk(CBlock& block, const CBlockIndex* pindex);
/** Functions for validating blocks and updating the block tree */
/** Undo the effects of this block (with given index) on the UTXO set represented by coins.
* In case pfClean is provided, operation will try to be tolerant about errors, and *pfClean
* will be true if no problems were found. Otherwise, the return value will be false in case
* of problems. Note that in any case, coins may be modified. */
bool DisconnectBlock(CBlock& block, CValidationState& state, CBlockIndex* pindex, CCoinsViewCache& coins, bool* pfClean = NULL);
// Apply the effects of this block (with given index) on the UTXO set represented by coins
bool ConnectBlock(CBlock& block, CValidationState& state, CBlockIndex* pindex, CCoinsViewCache& coins, bool fJustCheck = false);
// Add this block to the block index, and if necessary, switch the active block chain to this
bool AddToBlockIndex(CBlock& block, CValidationState& state, const CDiskBlockPos& pos);
// Context-independent validity checks
bool CheckBlockHeader(const CBlockHeader& block, CValidationState& state, bool fCheckPOW = true);
bool CheckBlock(const CBlock& block, CValidationState& state, bool fCheckPOW = true, bool fCheckMerkleRoot = true);
// Store block on disk
// if dbp is provided, the file is known to already reside on disk
bool AcceptBlock(CBlock& block, CValidationState& state, CBlockIndex **pindex, CDiskBlockPos* dbp = NULL);
bool AcceptBlockHeader(CBlockHeader& block, CValidationState& state, CBlockIndex **ppindex= NULL);
class CBlockFileInfo
unsigned int nBlocks; // number of blocks stored in file
unsigned int nSize; // number of used bytes of block file
unsigned int nUndoSize; // number of used bytes in the undo file
unsigned int nHeightFirst; // lowest height of block in file
unsigned int nHeightLast; // highest height of block in file
uint64_t nTimeFirst; // earliest time of block in file
uint64_t nTimeLast; // latest time of block in file
template <typename Stream, typename Operation>
inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
void SetNull() {
nBlocks = 0;
nSize = 0;
nUndoSize = 0;
nHeightFirst = 0;
nHeightLast = 0;
nTimeFirst = 0;
nTimeLast = 0;
CBlockFileInfo() {
std::string ToString() const;
// update statistics (does not update nSize)
void AddBlock(unsigned int nHeightIn, uint64_t nTimeIn) {
if (nBlocks==0 || nHeightFirst > nHeightIn)
nHeightFirst = nHeightIn;
if (nBlocks==0 || nTimeFirst > nTimeIn)
nTimeFirst = nTimeIn;
if (nHeightIn > nHeightLast)
nHeightLast = nHeightIn;
if (nTimeIn > nTimeLast)
nTimeLast = nTimeIn;
/** Capture information about block/transaction validation */
class CValidationState {
enum mode_state {
MODE_VALID, // everything ok
MODE_INVALID, // network rule violation (DoS value may be set)
MODE_ERROR, // run-time error
} mode;
int nDoS;
std::string strRejectReason;
unsigned char chRejectCode;
bool corruptionPossible;
CValidationState() : mode(MODE_VALID), nDoS(0), chRejectCode(0), corruptionPossible(false) {}
bool DoS(int level, bool ret = false,
unsigned char chRejectCodeIn=0, std::string strRejectReasonIn="",
bool corruptionIn=false) {
chRejectCode = chRejectCodeIn;
strRejectReason = strRejectReasonIn;
corruptionPossible = corruptionIn;
if (mode == MODE_ERROR)
return ret;
nDoS += level;
return ret;
bool Invalid(bool ret = false,
unsigned char _chRejectCode=0, std::string _strRejectReason="") {
return DoS(0, ret, _chRejectCode, _strRejectReason);
bool Error(std::string strRejectReasonIn="") {
if (mode == MODE_VALID)
strRejectReason = strRejectReasonIn;
mode = MODE_ERROR;
return false;
bool Abort(const std::string &msg) {
return Error(msg);
bool IsValid() const {
return mode == MODE_VALID;
bool IsInvalid() const {
return mode == MODE_INVALID;
bool IsError() const {
return mode == MODE_ERROR;
bool IsInvalid(int &nDoSOut) const {
if (IsInvalid()) {
nDoSOut = nDoS;
return true;
return false;
bool CorruptionPossible() const {
return corruptionPossible;
unsigned char GetRejectCode() const { return chRejectCode; }
std::string GetRejectReason() const { return strRejectReason; }
/** RAII wrapper for VerifyDB: Verify consistency of the block and coin databases */
class CVerifyDB {
bool VerifyDB(CCoinsView *coinsview, int nCheckLevel, int nCheckDepth);
/** Find the last common block between the parameter chain and a locator. */
CBlockIndex* FindForkInGlobalIndex(const CChain& chain, const CBlockLocator& locator);
/** The currently-connected chain of blocks. */
extern CChain chainActive;
/** Global variable that points to the active CCoinsView (protected by cs_main) */
extern CCoinsViewCache *pcoinsTip;
/** Global variable that points to the active block tree (protected by cs_main) */
extern CBlockTreeDB *pblocktree;
struct CBlockTemplate
CBlock block;
std::vector<CAmount> vTxFees;
std::vector<int64_t> vTxSigOps;
/** Used to relay blocks as header + vector<merkle branch>
* to filtered nodes.
class CMerkleBlock
// Public only for unit testing
CBlockHeader header;
CPartialMerkleTree txn;
// Public only for unit testing and relay testing
// (not relayed)
std::vector<std::pair<unsigned int, uint256> > vMatchedTxn;
// Create from a CBlock, filtering transactions according to filter
// Note that this will call IsRelevantAndUpdate on the filter for each transaction,
// thus the filter will likely be modified.
CMerkleBlock(const CBlock& block, CBloomFilter& filter);
template <typename Stream, typename Operation>
inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
class CWalletInterface {
virtual void SyncTransaction(const CTransaction &tx, const CBlock *pblock) =0;
virtual void EraseFromWallet(const uint256 &hash) =0;
virtual void SetBestChain(const CBlockLocator &locator) =0;
virtual void UpdatedTransaction(const uint256 &hash) =0;
virtual void Inventory(const uint256 &hash) =0;
virtual void ResendWalletTransactions() =0;
friend void ::RegisterWallet(CWalletInterface*);
friend void ::UnregisterWallet(CWalletInterface*);
friend void ::UnregisterAllWallets();
#endif // BITCOIN_MAIN_H