Beispiel #1
0
// Ingest puts a tx into the DB atomically.  This can result in a
// gain, a loss, or no result.  Gain or loss in satoshis is returned.
func (ts *TxStore) Ingest(tx *wire.MsgTx, height int32) (uint32, error) {
	var hits uint32
	var err error
	var nUtxoBytes [][]byte

	// tx has been OK'd by SPV; check tx sanity
	utilTx := btcutil.NewTx(tx) // convert for validation
	// checks basic stuff like there are inputs and ouputs
	err = blockchain.CheckTransactionSanity(utilTx)
	if err != nil {
		return hits, err
	}
	// note that you can't check signatures; this is SPV.
	// 0 conf SPV means pretty much nothing.  Anyone can say anything.

	spentOPs := make([][]byte, len(tx.TxIn))
	// before entering into db, serialize all inputs of the ingested tx
	for i, txin := range tx.TxIn {
		spentOPs[i], err = outPointToBytes(&txin.PreviousOutPoint)
		if err != nil {
			return hits, err
		}
	}

	// go through txouts, and then go through addresses to match

	// generate PKscripts for all addresses
	wPKscripts := make([][]byte, len(ts.Adrs))
	aPKscripts := make([][]byte, len(ts.Adrs))

	for i, _ := range ts.Adrs {
		// iterate through all our addresses
		// convert regular address to witness address.  (split adrs later)
		wa, err := btcutil.NewAddressWitnessPubKeyHash(
			ts.Adrs[i].PkhAdr.ScriptAddress(), ts.Param)
		if err != nil {
			return hits, err
		}

		wPKscripts[i], err = txscript.PayToAddrScript(wa)
		if err != nil {
			return hits, err
		}
		aPKscripts[i], err = txscript.PayToAddrScript(ts.Adrs[i].PkhAdr)
		if err != nil {
			return hits, err
		}
	}

	cachedSha := tx.TxSha()
	// iterate through all outputs of this tx, see if we gain
	for i, out := range tx.TxOut {
		for j, ascr := range aPKscripts {
			// detect p2wpkh
			witBool := false
			if bytes.Equal(out.PkScript, wPKscripts[j]) {
				witBool = true
			}
			if bytes.Equal(out.PkScript, ascr) || witBool { // new utxo found
				var newu Utxo // create new utxo and copy into it
				newu.AtHeight = height
				newu.KeyIdx = ts.Adrs[j].KeyIdx
				newu.Value = out.Value
				newu.IsWit = witBool // copy witness version from pkscript
				var newop wire.OutPoint
				newop.Hash = cachedSha
				newop.Index = uint32(i)
				newu.Op = newop
				b, err := newu.ToBytes()
				if err != nil {
					return hits, err
				}
				nUtxoBytes = append(nUtxoBytes, b)
				hits++
				break // txos can match only 1 script
			}
		}
	}

	err = ts.StateDB.Update(func(btx *bolt.Tx) error {
		// get all 4 buckets
		duf := btx.Bucket(BKTUtxos)
		//		sta := btx.Bucket(BKTState)
		old := btx.Bucket(BKTStxos)
		txns := btx.Bucket(BKTTxns)
		if duf == nil || old == nil || txns == nil {
			return fmt.Errorf("error: db not initialized")
		}

		// iterate through duffel bag and look for matches
		// this makes us lose money, which is regrettable, but we need to know.
		for _, nOP := range spentOPs {
			v := duf.Get(nOP)
			if v != nil {
				hits++
				// do all this just to figure out value we lost
				x := make([]byte, len(nOP)+len(v))
				copy(x, nOP)
				copy(x[len(nOP):], v)
				lostTxo, err := UtxoFromBytes(x)
				if err != nil {
					return err
				}

				// after marking for deletion, save stxo to old bucket
				var st Stxo               // generate spent txo
				st.Utxo = lostTxo         // assign outpoint
				st.SpendHeight = height   // spent at height
				st.SpendTxid = cachedSha  // spent by txid
				stxb, err := st.ToBytes() // serialize
				if err != nil {
					return err
				}
				err = old.Put(nOP, stxb) // write nOP:v outpoint:stxo bytes
				if err != nil {
					return err
				}

				err = duf.Delete(nOP)
				if err != nil {
					return err
				}
			}
		}

		// done losing utxos, next gain utxos
		// next add all new utxos to db, this is quick as the work is above
		for _, ub := range nUtxoBytes {
			err = duf.Put(ub[:36], ub[36:])
			if err != nil {
				return err
			}
		}

		// if hits is nonzero it's a relevant tx and we should store it
		var buf bytes.Buffer
		tx.Serialize(&buf)
		err = txns.Put(cachedSha.Bytes(), buf.Bytes())
		if err != nil {
			return err
		}

		return nil
	})
	return hits, err
}
Beispiel #2
0
// maybeAcceptTransaction is the internal function which implements the public
// MaybeAcceptTransaction.  See the comment for MaybeAcceptTransaction for
// more details.
//
// This function MUST be called with the mempool lock held (for writes).
func (mp *TxPool) maybeAcceptTransaction(tx *btcutil.Tx, isNew, rateLimit, rejectDupOrphans bool) ([]*chainhash.Hash, *TxDesc, error) {
	txHash := tx.Hash()

	// Don't accept the transaction if it already exists in the pool.  This
	// applies to orphan transactions as well when the reject duplicate
	// orphans flag is set.  This check is intended to be a quick check to
	// weed out duplicates.
	if mp.isTransactionInPool(txHash) || (rejectDupOrphans &&
		mp.isOrphanInPool(txHash)) {

		str := fmt.Sprintf("already have transaction %v", txHash)
		return nil, nil, txRuleError(wire.RejectDuplicate, str)
	}

	// Perform preliminary sanity checks on the transaction.  This makes
	// use of blockchain which contains the invariant rules for what
	// transactions are allowed into blocks.
	err := blockchain.CheckTransactionSanity(tx)
	if err != nil {
		if cerr, ok := err.(blockchain.RuleError); ok {
			return nil, nil, chainRuleError(cerr)
		}
		return nil, nil, err
	}

	// A standalone transaction must not be a coinbase transaction.
	if blockchain.IsCoinBase(tx) {
		str := fmt.Sprintf("transaction %v is an individual coinbase",
			txHash)
		return nil, nil, txRuleError(wire.RejectInvalid, str)
	}

	// Don't accept transactions with a lock time after the maximum int32
	// value for now.  This is an artifact of older bitcoind clients which
	// treated this field as an int32 and would treat anything larger
	// incorrectly (as negative).
	if tx.MsgTx().LockTime > math.MaxInt32 {
		str := fmt.Sprintf("transaction %v has a lock time after "+
			"2038 which is not accepted yet", txHash)
		return nil, nil, txRuleError(wire.RejectNonstandard, str)
	}

	// Get the current height of the main chain.  A standalone transaction
	// will be mined into the next block at best, so its height is at least
	// one more than the current height.
	bestHeight := mp.cfg.BestHeight()
	nextBlockHeight := bestHeight + 1

	medianTimePast := mp.cfg.MedianTimePast()

	// Don't allow non-standard transactions if the network parameters
	// forbid their acceptance.
	if !mp.cfg.Policy.AcceptNonStd {
		err = checkTransactionStandard(tx, nextBlockHeight,
			medianTimePast, mp.cfg.Policy.MinRelayTxFee,
			mp.cfg.Policy.MaxTxVersion)
		if err != nil {
			// Attempt to extract a reject code from the error so
			// it can be retained.  When not possible, fall back to
			// a non standard error.
			rejectCode, found := extractRejectCode(err)
			if !found {
				rejectCode = wire.RejectNonstandard
			}
			str := fmt.Sprintf("transaction %v is not standard: %v",
				txHash, err)
			return nil, nil, txRuleError(rejectCode, str)
		}
	}

	// The transaction may not use any of the same outputs as other
	// transactions already in the pool as that would ultimately result in a
	// double spend.  This check is intended to be quick and therefore only
	// detects double spends within the transaction pool itself.  The
	// transaction could still be double spending coins from the main chain
	// at this point.  There is a more in-depth check that happens later
	// after fetching the referenced transaction inputs from the main chain
	// which examines the actual spend data and prevents double spends.
	err = mp.checkPoolDoubleSpend(tx)
	if err != nil {
		return nil, nil, err
	}

	// Fetch all of the unspent transaction outputs referenced by the inputs
	// to this transaction.  This function also attempts to fetch the
	// transaction itself to be used for detecting a duplicate transaction
	// without needing to do a separate lookup.
	utxoView, err := mp.fetchInputUtxos(tx)
	if err != nil {
		if cerr, ok := err.(blockchain.RuleError); ok {
			return nil, nil, chainRuleError(cerr)
		}
		return nil, nil, err
	}

	// Don't allow the transaction if it exists in the main chain and is not
	// not already fully spent.
	txEntry := utxoView.LookupEntry(txHash)
	if txEntry != nil && !txEntry.IsFullySpent() {
		return nil, nil, txRuleError(wire.RejectDuplicate,
			"transaction already exists")
	}
	delete(utxoView.Entries(), *txHash)

	// Transaction is an orphan if any of the referenced input transactions
	// don't exist.  Adding orphans to the orphan pool is not handled by
	// this function, and the caller should use maybeAddOrphan if this
	// behavior is desired.
	var missingParents []*chainhash.Hash
	for originHash, entry := range utxoView.Entries() {
		if entry == nil || entry.IsFullySpent() {
			// Must make a copy of the hash here since the iterator
			// is replaced and taking its address directly would
			// result in all of the entries pointing to the same
			// memory location and thus all be the final hash.
			hashCopy := originHash
			missingParents = append(missingParents, &hashCopy)
		}
	}
	if len(missingParents) > 0 {
		return missingParents, nil, nil
	}

	// Don't allow the transaction into the mempool unless its sequence
	// lock is active, meaning that it'll be allowed into the next block
	// with respect to its defined relative lock times.
	sequenceLock, err := mp.cfg.CalcSequenceLock(tx, utxoView)
	if err != nil {
		if cerr, ok := err.(blockchain.RuleError); ok {
			return nil, nil, chainRuleError(cerr)
		}
		return nil, nil, err
	}
	if !blockchain.SequenceLockActive(sequenceLock, nextBlockHeight,
		medianTimePast) {
		return nil, nil, txRuleError(wire.RejectNonstandard,
			"transaction's sequence locks on inputs not met")
	}

	// Perform several checks on the transaction inputs using the invariant
	// rules in blockchain for what transactions are allowed into blocks.
	// Also returns the fees associated with the transaction which will be
	// used later.
	txFee, err := blockchain.CheckTransactionInputs(tx, nextBlockHeight,
		utxoView, mp.cfg.ChainParams)
	if err != nil {
		if cerr, ok := err.(blockchain.RuleError); ok {
			return nil, nil, chainRuleError(cerr)
		}
		return nil, nil, err
	}

	// Don't allow transactions with non-standard inputs if the network
	// parameters forbid their acceptance.
	if !mp.cfg.Policy.AcceptNonStd {
		err := checkInputsStandard(tx, utxoView)
		if err != nil {
			// Attempt to extract a reject code from the error so
			// it can be retained.  When not possible, fall back to
			// a non standard error.
			rejectCode, found := extractRejectCode(err)
			if !found {
				rejectCode = wire.RejectNonstandard
			}
			str := fmt.Sprintf("transaction %v has a non-standard "+
				"input: %v", txHash, err)
			return nil, nil, txRuleError(rejectCode, str)
		}
	}

	// NOTE: if you modify this code to accept non-standard transactions,
	// you should add code here to check that the transaction does a
	// reasonable number of ECDSA signature verifications.

	// Don't allow transactions with an excessive number of signature
	// operations which would result in making it impossible to mine.  Since
	// the coinbase address itself can contain signature operations, the
	// maximum allowed signature operations per transaction is less than
	// the maximum allowed signature operations per block.
	// TODO(roasbeef): last bool should be conditional on segwit activation
	sigOpCost, err := blockchain.GetSigOpCost(tx, false, utxoView, true, true)
	if err != nil {
		if cerr, ok := err.(blockchain.RuleError); ok {
			return nil, nil, chainRuleError(cerr)
		}
		return nil, nil, err
	}
	if sigOpCost > mp.cfg.Policy.MaxSigOpCostPerTx {
		str := fmt.Sprintf("transaction %v sigop cost is too high: %d > %d",
			txHash, sigOpCost, maxStandardSigOpsCost)
		return nil, nil, txRuleError(wire.RejectNonstandard, str)
	}

	// Don't allow transactions with fees too low to get into a mined block.
	//
	// Most miners allow a free transaction area in blocks they mine to go
	// alongside the area used for high-priority transactions as well as
	// transactions with fees.  A transaction size of up to 1000 bytes is
	// considered safe to go into this section.  Further, the minimum fee
	// calculated below on its own would encourage several small
	// transactions to avoid fees rather than one single larger transaction
	// which is more desirable.  Therefore, as long as the size of the
	// transaction does not exceeed 1000 less than the reserved space for
	// high-priority transactions, don't require a fee for it.
	serializedSize := blockchain.GetTxVirtualSize(tx)
	minFee := calcMinRequiredTxRelayFee(serializedSize,
		mp.cfg.Policy.MinRelayTxFee)
	if serializedSize >= (DefaultBlockPrioritySize-1000) && txFee < minFee {
		str := fmt.Sprintf("transaction %v has %d fees which is under "+
			"the required amount of %d", txHash, txFee,
			minFee)
		return nil, nil, txRuleError(wire.RejectInsufficientFee, str)
	}

	// Require that free transactions have sufficient priority to be mined
	// in the next block.  Transactions which are being added back to the
	// memory pool from blocks that have been disconnected during a reorg
	// are exempted.
	if isNew && !mp.cfg.Policy.DisableRelayPriority && txFee < minFee {
		currentPriority := mining.CalcPriority(tx.MsgTx(), utxoView,
			nextBlockHeight)
		if currentPriority <= mining.MinHighPriority {
			str := fmt.Sprintf("transaction %v has insufficient "+
				"priority (%g <= %g)", txHash,
				currentPriority, mining.MinHighPriority)
			return nil, nil, txRuleError(wire.RejectInsufficientFee, str)
		}
	}

	// Free-to-relay transactions are rate limited here to prevent
	// penny-flooding with tiny transactions as a form of attack.
	if rateLimit && txFee < minFee {
		nowUnix := time.Now().Unix()
		// Decay passed data with an exponentially decaying ~10 minute
		// window - matches bitcoind handling.
		mp.pennyTotal *= math.Pow(1.0-1.0/600.0,
			float64(nowUnix-mp.lastPennyUnix))
		mp.lastPennyUnix = nowUnix

		// Are we still over the limit?
		if mp.pennyTotal >= mp.cfg.Policy.FreeTxRelayLimit*10*1000 {
			str := fmt.Sprintf("transaction %v has been rejected "+
				"by the rate limiter due to low fees", txHash)
			return nil, nil, txRuleError(wire.RejectInsufficientFee, str)
		}
		oldTotal := mp.pennyTotal

		mp.pennyTotal += float64(serializedSize)
		log.Tracef("rate limit: curTotal %v, nextTotal: %v, "+
			"limit %v", oldTotal, mp.pennyTotal,
			mp.cfg.Policy.FreeTxRelayLimit*10*1000)
	}

	// Verify crypto signatures for each input and reject the transaction if
	// any don't verify.
	err = blockchain.ValidateTransactionScripts(tx, utxoView,
		txscript.StandardVerifyFlags, mp.cfg.SigCache,
		mp.cfg.HashCache)
	if err != nil {
		if cerr, ok := err.(blockchain.RuleError); ok {
			return nil, nil, chainRuleError(cerr)
		}
		return nil, nil, err
	}

	// Add to transaction pool.
	txD := mp.addTransaction(utxoView, tx, bestHeight, txFee)

	log.Debugf("Accepted transaction %v (pool size: %v)", txHash,
		len(mp.pool))

	return nil, txD, nil
}