policy.cpp File Reference

#include <policy/policy.h>
#include <validation.h>
#include <coins.h>
#include <tinyformat.h>
#include <util.h>
#include <utilstrencodings.h>

Include dependency graph for policy.cpp:

Go to the source code of this file.

Functions
CAmount	GetDustThreshold (const CTxOut &txout, const CFeeRate &dustRelayFeeIn)
bool	IsDust (const CTxOut &txout, const CFeeRate &dustRelayFeeIn)
bool	IsStandard (const CScript &scriptPubKey, txnouttype &whichType)
bool	IsStandardTx (const CTransaction &tx, std::string &reason)
	Check for standard transaction types. More...
bool	AreInputsStandard (const CTransaction &tx, const CCoinsViewCache &mapInputs)
	Check transaction inputs to mitigate two potential denial-of-service attacks: More...

Variables
CFeeRate	incrementalRelayFee = CFeeRate(DEFAULT_INCREMENTAL_RELAY_FEE)
CFeeRate	dustRelayFee = CFeeRate(DUST_RELAY_TX_FEE)

Function Documentation

AreInputsStandard()

bool AreInputsStandard	(	const CTransaction &	tx,
		const CCoinsViewCache &	mapInputs
	)

Check transaction inputs to mitigate two potential denial-of-service attacks:

Check for standard transaction types.

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

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

Definition at line 142 of file policy.cpp.

References CCoinsViewCache::AccessCoin(), EvalScript(), CTransaction::IsCoinBase(), MAX_P2SH_SIGOPS, Coin::out, SCRIPT_VERIFY_NONE, CTxOut::scriptPubKey, SIGVERSION_BASE, Solver(), TX_SCRIPTHASH, and CTransaction::vin.

Referenced by AcceptToMemoryPoolWorker(), and CCoinsCaching().

GetDustThreshold()

CAmount GetDustThreshold	(	const CTxOut &	txout,
		const CFeeRate &	dustRelayFeeIn
	)

Definition at line 17 of file policy.cpp.

References CFeeRate::GetFee(), GetSerializeSize(), CScript::IsUnspendable(), CTxOut::scriptPubKey, and SER_DISK.

Referenced by IsDust().

IsDust()

bool IsDust	(	const CTxOut &	txout,
		const CFeeRate &	dustRelayFeeIn
	)

Definition at line 35 of file policy.cpp.

References GetDustThreshold(), and CTxOut::nValue.

Referenced by CWallet::CreateTransaction(), CTransactionBuilder::IsDust(), GUIUtil::isDust(), IsStandardTx(), PaymentServer::processPaymentRequest(), and CoinControlDialog::updateLabels().

IsStandard()

bool IsStandard	(	const CScript &	scriptPubKey,
		txnouttype &	whichType
	)

Definition at line 40 of file policy.cpp.

References fAcceptDatacarrier, nMaxDatacarrierBytes, prevector< N, T, Size, Diff >::size(), Solver(), TX_MULTISIG, TX_NONSTANDARD, and TX_NULL_DATA.

Referenced by IsStandardTx().

IsStandardTx()

bool IsStandardTx	(	const CTransaction &	tx,
		std::string &	reason
	)

Check for standard transaction types.

Returns

True if all outputs (scriptPubKeys) use only standard transaction forms

Definition at line 62 of file policy.cpp.

References CTransaction::CURRENT_VERSION, dustRelayFee, fIsBareMultisigStd, GetSerializeSize(), IsDust(), CScript::IsPushOnly(), IsStandard(), MAX_STANDARD_TX_SIZE, CTransaction::MAX_STANDARD_VERSION, CTransaction::nVersion, FeeCalculation::reason, CTxOut::scriptPubKey, CTxIn::scriptSig, SER_NETWORK, prevector< N, T, Size, Diff >::size(), TX_MULTISIG, TX_NULL_DATA, CTransaction::vin, and CTransaction::vout.

Referenced by AcceptToMemoryPoolWorker().

Variable Documentation

dustRelayFee

CFeeRate dustRelayFee = CFeeRate(DUST_RELAY_TX_FEE)

Definition at line 177 of file policy.cpp.

Referenced by AppInitParameterInteraction(), CWallet::CreateTransaction(), GetDiscardRate(), GUIUtil::isDust(), IsStandardTx(), PaymentServer::processPaymentRequest(), and CoinControlDialog::updateLabels().

incrementalRelayFee

CFeeRate incrementalRelayFee = CFeeRate(DEFAULT_INCREMENTAL_RELAY_FEE)

Definition at line 176 of file policy.cpp.

Referenced by AppInitParameterInteraction(), CTxMemPool::GetMinFee(), getnetworkinfo(), and CTxMemPool::TrimToSize().