diff options
| -rwxr-xr-x | qa/pull-tester/rpc-tests.py | 1 | ||||
| -rw-r--r-- | qa/replace-by-fee/.gitignore | 1 | ||||
| -rw-r--r-- | qa/replace-by-fee/README.md | 13 | ||||
| -rwxr-xr-x | qa/replace-by-fee/rbf-tests.py | 360 | ||||
| -rwxr-xr-x | qa/rpc-tests/replace-by-fee.py | 512 | ||||
| -rw-r--r-- | src/main.cpp | 202 | ||||
| -rw-r--r-- | src/txmempool.h | 9 |
7 files changed, 1089 insertions, 9 deletions
diff --git a/qa/pull-tester/rpc-tests.py b/qa/pull-tester/rpc-tests.py index 7a30db68dd..3d156a2e7b 100755 --- a/qa/pull-tester/rpc-tests.py +++ b/qa/pull-tester/rpc-tests.py @@ -112,6 +112,7 @@ testScriptsExt = [ 'p2p-acceptblock.py', 'mempool_packages.py', 'maxuploadtarget.py', + 'replace-by-fee.py', ] #Enable ZMQ tests diff --git a/qa/replace-by-fee/.gitignore b/qa/replace-by-fee/.gitignore new file mode 100644 index 0000000000..b2c4f4657a --- /dev/null +++ b/qa/replace-by-fee/.gitignore @@ -0,0 +1 @@ +python-bitcoinlib diff --git a/qa/replace-by-fee/README.md b/qa/replace-by-fee/README.md new file mode 100644 index 0000000000..baad86de9a --- /dev/null +++ b/qa/replace-by-fee/README.md @@ -0,0 +1,13 @@ +Replace-by-fee regression tests +=============================== + +First get version v0.5.0 of the python-bitcoinlib library. In this directory +run: + + git clone -n https://github.com/petertodd/python-bitcoinlib + (cd python-bitcoinlib && git checkout 8270bfd9c6ac37907d75db3d8b9152d61c7255cd) + +Then run the tests themselves with a bitcoind available running in regtest +mode: + + ./rbf-tests.py diff --git a/qa/replace-by-fee/rbf-tests.py b/qa/replace-by-fee/rbf-tests.py new file mode 100755 index 0000000000..1ee6c83875 --- /dev/null +++ b/qa/replace-by-fee/rbf-tests.py @@ -0,0 +1,360 @@ +#!/usr/bin/env python3 +# Copyright (c) 2015 The Bitcoin Core developers +# Distributed under the MIT software license, see the accompanying +# file COPYING or http://www.opensource.org/licenses/mit-license.php. + +# +# Test replace-by-fee +# + +import os +import sys + +# Add python-bitcoinlib to module search path, prior to any system-wide +# python-bitcoinlib. +sys.path.insert(0, os.path.join(os.path.dirname(os.path.abspath(__file__)), "python-bitcoinlib")) + +import unittest + +import bitcoin +bitcoin.SelectParams('regtest') + +import bitcoin.rpc + +from bitcoin.core import * +from bitcoin.core.script import * +from bitcoin.wallet import * + +MAX_REPLACEMENT_LIMIT = 100 + +class Test_ReplaceByFee(unittest.TestCase): + proxy = None + + @classmethod + def setUpClass(cls): + if cls.proxy is None: + cls.proxy = bitcoin.rpc.Proxy() + + @classmethod + def mine_mempool(cls): + """Mine until mempool is empty""" + mempool_size = 1 + while mempool_size: + cls.proxy.call('generate', 1) + new_mempool_size = len(cls.proxy.getrawmempool()) + + # It's possible to get stuck in a loop here if the mempool has + # transactions that can't be mined. + assert(new_mempool_size != mempool_size) + mempool_size = new_mempool_size + + @classmethod + def tearDownClass(cls): + # Make sure mining works + cls.mine_mempool() + + def make_txout(self, amount, confirmed=True, scriptPubKey=CScript([1])): + """Create a txout with a given amount and scriptPubKey + + Mines coins as needed. + + confirmed - txouts created will be confirmed in the blockchain; + unconfirmed otherwise. + """ + fee = 1*COIN + while self.proxy.getbalance() < amount + fee: + self.proxy.call('generate', 100) + + addr = P2SHBitcoinAddress.from_redeemScript(CScript([])) + txid = self.proxy.sendtoaddress(addr, amount + fee) + + tx1 = self.proxy.getrawtransaction(txid) + + i = None + for i, txout in enumerate(tx1.vout): + if txout.scriptPubKey == addr.to_scriptPubKey(): + break + assert i is not None + + tx2 = CTransaction([CTxIn(COutPoint(txid, i), CScript([1, CScript([])]), nSequence=0)], + [CTxOut(amount, scriptPubKey)]) + + tx2_txid = self.proxy.sendrawtransaction(tx2, True) + + # If requested, ensure txouts are confirmed. + if confirmed: + self.mine_mempool() + + return COutPoint(tx2_txid, 0) + + def test_simple_doublespend(self): + """Simple doublespend""" + tx0_outpoint = self.make_txout(1.1*COIN) + + tx1a = CTransaction([CTxIn(tx0_outpoint, nSequence=0)], + [CTxOut(1*COIN, CScript([b'a']))]) + tx1a_txid = self.proxy.sendrawtransaction(tx1a, True) + + # Should fail because we haven't changed the fee + tx1b = CTransaction([CTxIn(tx0_outpoint, nSequence=0)], + [CTxOut(1*COIN, CScript([b'b']))]) + + try: + tx1b_txid = self.proxy.sendrawtransaction(tx1b, True) + except bitcoin.rpc.JSONRPCException as exp: + self.assertEqual(exp.error['code'], -26) # insufficient fee + else: + self.fail() + + # Extra 0.1 BTC fee + tx1b = CTransaction([CTxIn(tx0_outpoint, nSequence=0)], + [CTxOut(0.9*COIN, CScript([b'b']))]) + tx1b_txid = self.proxy.sendrawtransaction(tx1b, True) + + # tx1a is in fact replaced + with self.assertRaises(IndexError): + self.proxy.getrawtransaction(tx1a_txid) + + self.assertEqual(tx1b, self.proxy.getrawtransaction(tx1b_txid)) + + def test_doublespend_chain(self): + """Doublespend of a long chain""" + + initial_nValue = 50*COIN + tx0_outpoint = self.make_txout(initial_nValue) + + prevout = tx0_outpoint + remaining_value = initial_nValue + chain_txids = [] + while remaining_value > 10*COIN: + remaining_value -= 1*COIN + tx = CTransaction([CTxIn(prevout, nSequence=0)], + [CTxOut(remaining_value, CScript([1]))]) + txid = self.proxy.sendrawtransaction(tx, True) + chain_txids.append(txid) + prevout = COutPoint(txid, 0) + + # Whether the double-spend is allowed is evaluated by including all + # child fees - 40 BTC - so this attempt is rejected. + dbl_tx = CTransaction([CTxIn(tx0_outpoint, nSequence=0)], + [CTxOut(initial_nValue - 30*COIN, CScript([1]))]) + + try: + self.proxy.sendrawtransaction(dbl_tx, True) + except bitcoin.rpc.JSONRPCException as exp: + self.assertEqual(exp.error['code'], -26) # insufficient fee + else: + self.fail() + + # Accepted with sufficient fee + dbl_tx = CTransaction([CTxIn(tx0_outpoint, nSequence=0)], + [CTxOut(1*COIN, CScript([1]))]) + self.proxy.sendrawtransaction(dbl_tx, True) + + for doublespent_txid in chain_txids: + with self.assertRaises(IndexError): + self.proxy.getrawtransaction(doublespent_txid) + + def test_doublespend_tree(self): + """Doublespend of a big tree of transactions""" + + initial_nValue = 50*COIN + tx0_outpoint = self.make_txout(initial_nValue) + + def branch(prevout, initial_value, max_txs, *, tree_width=5, fee=0.0001*COIN, _total_txs=None): + if _total_txs is None: + _total_txs = [0] + if _total_txs[0] >= max_txs: + return + + txout_value = (initial_value - fee) // tree_width + if txout_value < fee: + return + + vout = [CTxOut(txout_value, CScript([i+1])) + for i in range(tree_width)] + tx = CTransaction([CTxIn(prevout, nSequence=0)], + vout) + + self.assertTrue(len(tx.serialize()) < 100000) + txid = self.proxy.sendrawtransaction(tx, True) + yield tx + _total_txs[0] += 1 + + for i, txout in enumerate(tx.vout): + yield from branch(COutPoint(txid, i), txout_value, + max_txs, + tree_width=tree_width, fee=fee, + _total_txs=_total_txs) + + fee = 0.0001*COIN + n = MAX_REPLACEMENT_LIMIT + tree_txs = list(branch(tx0_outpoint, initial_nValue, n, fee=fee)) + self.assertEqual(len(tree_txs), n) + + # Attempt double-spend, will fail because too little fee paid + dbl_tx = CTransaction([CTxIn(tx0_outpoint, nSequence=0)], + [CTxOut(initial_nValue - fee*n, CScript([1]))]) + try: + self.proxy.sendrawtransaction(dbl_tx, True) + except bitcoin.rpc.JSONRPCException as exp: + self.assertEqual(exp.error['code'], -26) # insufficient fee + else: + self.fail() + + # 1 BTC fee is enough + dbl_tx = CTransaction([CTxIn(tx0_outpoint, nSequence=0)], + [CTxOut(initial_nValue - fee*n - 1*COIN, CScript([1]))]) + self.proxy.sendrawtransaction(dbl_tx, True) + + for tx in tree_txs: + with self.assertRaises(IndexError): + self.proxy.getrawtransaction(tx.GetHash()) + + # Try again, but with more total transactions than the "max txs + # double-spent at once" anti-DoS limit. + for n in (MAX_REPLACEMENT_LIMIT, MAX_REPLACEMENT_LIMIT*2): + fee = 0.0001*COIN + tx0_outpoint = self.make_txout(initial_nValue) + tree_txs = list(branch(tx0_outpoint, initial_nValue, n, fee=fee)) + self.assertEqual(len(tree_txs), n) + + dbl_tx = CTransaction([CTxIn(tx0_outpoint, nSequence=0)], + [CTxOut(initial_nValue - fee*n, CScript([1]))]) + try: + self.proxy.sendrawtransaction(dbl_tx, True) + except bitcoin.rpc.JSONRPCException as exp: + self.assertEqual(exp.error['code'], -26) + else: + self.fail() + + for tx in tree_txs: + self.proxy.getrawtransaction(tx.GetHash()) + + def test_replacement_feeperkb(self): + """Replacement requires fee-per-KB to be higher""" + tx0_outpoint = self.make_txout(1.1*COIN) + + tx1a = CTransaction([CTxIn(tx0_outpoint, nSequence=0)], + [CTxOut(1*COIN, CScript([b'a']))]) + tx1a_txid = self.proxy.sendrawtransaction(tx1a, True) + + # Higher fee, but the fee per KB is much lower, so the replacement is + # rejected. + tx1b = CTransaction([CTxIn(tx0_outpoint, nSequence=0)], + [CTxOut(0.001*COIN, + CScript([b'a'*999000]))]) + + try: + tx1b_txid = self.proxy.sendrawtransaction(tx1b, True) + except bitcoin.rpc.JSONRPCException as exp: + self.assertEqual(exp.error['code'], -26) # insufficient fee + else: + self.fail() + + def test_spends_of_conflicting_outputs(self): + """Replacements that spend conflicting tx outputs are rejected""" + utxo1 = self.make_txout(1.2*COIN) + utxo2 = self.make_txout(3.0*COIN) + + tx1a = CTransaction([CTxIn(utxo1, nSequence=0)], + [CTxOut(1.1*COIN, CScript([b'a']))]) + tx1a_txid = self.proxy.sendrawtransaction(tx1a, True) + + # Direct spend an output of the transaction we're replacing. + tx2 = CTransaction([CTxIn(utxo1, nSequence=0), CTxIn(utxo2, nSequence=0), + CTxIn(COutPoint(tx1a_txid, 0), nSequence=0)], + tx1a.vout) + + try: + tx2_txid = self.proxy.sendrawtransaction(tx2, True) + except bitcoin.rpc.JSONRPCException as exp: + self.assertEqual(exp.error['code'], -26) + else: + self.fail() + + # Spend tx1a's output to test the indirect case. + tx1b = CTransaction([CTxIn(COutPoint(tx1a_txid, 0), nSequence=0)], + [CTxOut(1.0*COIN, CScript([b'a']))]) + tx1b_txid = self.proxy.sendrawtransaction(tx1b, True) + + tx2 = CTransaction([CTxIn(utxo1, nSequence=0), CTxIn(utxo2, nSequence=0), + CTxIn(COutPoint(tx1b_txid, 0))], + tx1a.vout) + + try: + tx2_txid = self.proxy.sendrawtransaction(tx2, True) + except bitcoin.rpc.JSONRPCException as exp: + self.assertEqual(exp.error['code'], -26) + else: + self.fail() + + def test_new_unconfirmed_inputs(self): + """Replacements that add new unconfirmed inputs are rejected""" + confirmed_utxo = self.make_txout(1.1*COIN) + unconfirmed_utxo = self.make_txout(0.1*COIN, False) + + tx1 = CTransaction([CTxIn(confirmed_utxo)], + [CTxOut(1.0*COIN, CScript([b'a']))]) + tx1_txid = self.proxy.sendrawtransaction(tx1, True) + + tx2 = CTransaction([CTxIn(confirmed_utxo), CTxIn(unconfirmed_utxo)], + tx1.vout) + + try: + tx2_txid = self.proxy.sendrawtransaction(tx2, True) + except bitcoin.rpc.JSONRPCException as exp: + self.assertEqual(exp.error['code'], -26) + else: + self.fail() + + def test_too_many_replacements(self): + """Replacements that evict too many transactions are rejected""" + # Try directly replacing more than MAX_REPLACEMENT_LIMIT + # transactions + + # Start by creating a single transaction with many outputs + initial_nValue = 10*COIN + utxo = self.make_txout(initial_nValue) + fee = 0.0001*COIN + split_value = int((initial_nValue-fee)/(MAX_REPLACEMENT_LIMIT+1)) + actual_fee = initial_nValue - split_value*(MAX_REPLACEMENT_LIMIT+1) + + outputs = [] + for i in range(MAX_REPLACEMENT_LIMIT+1): + outputs.append(CTxOut(split_value, CScript([1]))) + + splitting_tx = CTransaction([CTxIn(utxo, nSequence=0)], outputs) + txid = self.proxy.sendrawtransaction(splitting_tx, True) + + # Now spend each of those outputs individually + for i in range(MAX_REPLACEMENT_LIMIT+1): + tx_i = CTransaction([CTxIn(COutPoint(txid, i), nSequence=0)], + [CTxOut(split_value-fee, CScript([b'a']))]) + self.proxy.sendrawtransaction(tx_i, True) + + # Now create doublespend of the whole lot, should fail + # Need a big enough fee to cover all spending transactions and have + # a higher fee rate + double_spend_value = (split_value-100*fee)*(MAX_REPLACEMENT_LIMIT+1) + inputs = [] + for i in range(MAX_REPLACEMENT_LIMIT+1): + inputs.append(CTxIn(COutPoint(txid, i), nSequence=0)) + double_tx = CTransaction(inputs, [CTxOut(double_spend_value, CScript([b'a']))]) + + try: + self.proxy.sendrawtransaction(double_tx, True) + except bitcoin.rpc.JSONRPCException as exp: + self.assertEqual(exp.error['code'], -26) + self.assertEqual("too many potential replacements" in exp.error['message'], True) + else: + self.fail() + + # If we remove an input, it should pass + double_tx = CTransaction(inputs[0:-1], + [CTxOut(double_spend_value, CScript([b'a']))]) + + self.proxy.sendrawtransaction(double_tx, True) + +if __name__ == '__main__': + unittest.main() diff --git a/qa/rpc-tests/replace-by-fee.py b/qa/rpc-tests/replace-by-fee.py new file mode 100755 index 0000000000..537a1ed8d9 --- /dev/null +++ b/qa/rpc-tests/replace-by-fee.py @@ -0,0 +1,512 @@ +#!/usr/bin/env python2 +# Copyright (c) 2014-2015 The Bitcoin Core developers +# Distributed under the MIT software license, see the accompanying +# file COPYING or http://www.opensource.org/licenses/mit-license.php. + +# +# Test replace by fee code +# + +from test_framework.test_framework import BitcoinTestFramework +from test_framework.util import * +from test_framework.script import * +from test_framework.mininode import * +import binascii + +COIN = 100000000 +MAX_REPLACEMENT_LIMIT = 100 + +def satoshi_round(amount): + return Decimal(amount).quantize(Decimal('0.00000001'), rounding=ROUND_DOWN) + +def txToHex(tx): + return binascii.hexlify(tx.serialize()).decode('utf-8') + +def make_utxo(node, amount, confirmed=True, scriptPubKey=CScript([1])): + """Create a txout with a given amount and scriptPubKey + + Mines coins as needed. + + confirmed - txouts created will be confirmed in the blockchain; + unconfirmed otherwise. + """ + fee = 1*COIN + while node.getbalance() < satoshi_round((amount + fee)/COIN): + node.generate(100) + #print (node.getbalance(), amount, fee) + + new_addr = node.getnewaddress() + #print new_addr + txid = node.sendtoaddress(new_addr, satoshi_round((amount+fee)/COIN)) + tx1 = node.getrawtransaction(txid, 1) + txid = int(txid, 16) + i = None + + for i, txout in enumerate(tx1['vout']): + #print i, txout['scriptPubKey']['addresses'] + if txout['scriptPubKey']['addresses'] == [new_addr]: + #print i + break + assert i is not None + + tx2 = CTransaction() + tx2.vin = [CTxIn(COutPoint(txid, i))] + tx2.vout = [CTxOut(amount, scriptPubKey)] + tx2.rehash() + + tx2_hex = binascii.hexlify(tx2.serialize()).decode('utf-8') + #print tx2_hex + + signed_tx = node.signrawtransaction(binascii.hexlify(tx2.serialize()).decode('utf-8')) + + txid = node.sendrawtransaction(signed_tx['hex'], True) + + # If requested, ensure txouts are confirmed. + if confirmed: + while len(node.getrawmempool()): + node.generate(1) + + return COutPoint(int(txid, 16), 0) + +class ReplaceByFeeTest(BitcoinTestFramework): + + def setup_network(self): + self.nodes = [] + self.nodes.append(start_node(0, self.options.tmpdir, ["-maxorphantx=1000", + "-relaypriority=0", "-whitelist=127.0.0.1"])) + self.is_network_split = False + + def run_test(self): + make_utxo(self.nodes[0], 1*COIN) + + print "Running test simple doublespend..." + self.test_simple_doublespend() + + print "Running test doublespend chain..." + self.test_doublespend_chain() + + print "Running test doublespend tree..." + self.test_doublespend_tree() + + print "Running test replacement feeperkb..." + self.test_replacement_feeperkb() + + print "Running test spends of conflicting outputs..." + self.test_spends_of_conflicting_outputs() + + print "Running test new unconfirmed inputs..." + self.test_new_unconfirmed_inputs() + + print "Running test too many replacements..." + self.test_too_many_replacements() + + print "Running test opt-in..." + self.test_opt_in() + + print "Passed\n" + + def test_simple_doublespend(self): + """Simple doublespend""" + tx0_outpoint = make_utxo(self.nodes[0], 1.1*COIN) + + tx1a = CTransaction() + tx1a.vin = [CTxIn(tx0_outpoint, nSequence=0)] + tx1a.vout = [CTxOut(1*COIN, CScript([b'a']))] + tx1a_hex = txToHex(tx1a) + tx1a_txid = self.nodes[0].sendrawtransaction(tx1a_hex, True) + + # Should fail because we haven't changed the fee + tx1b = CTransaction() + tx1b.vin = [CTxIn(tx0_outpoint, nSequence=0)] + tx1b.vout = [CTxOut(1*COIN, CScript([b'b']))] + tx1b_hex = txToHex(tx1b) + + try: + tx1b_txid = self.nodes[0].sendrawtransaction(tx1b_hex, True) + except JSONRPCException as exp: + assert_equal(exp.error['code'], -26) # insufficient fee + else: + assert(False) + + # Extra 0.1 BTC fee + tx1b = CTransaction() + tx1b.vin = [CTxIn(tx0_outpoint, nSequence=0)] + tx1b.vout = [CTxOut(0.9*COIN, CScript([b'b']))] + tx1b_hex = txToHex(tx1b) + tx1b_txid = self.nodes[0].sendrawtransaction(tx1b_hex, True) + + mempool = self.nodes[0].getrawmempool() + + assert (tx1a_txid not in mempool) + assert (tx1b_txid in mempool) + + assert_equal(tx1b_hex, self.nodes[0].getrawtransaction(tx1b_txid)) + + def test_doublespend_chain(self): + """Doublespend of a long chain""" + + initial_nValue = 50*COIN + tx0_outpoint = make_utxo(self.nodes[0], initial_nValue) + + prevout = tx0_outpoint + remaining_value = initial_nValue + chain_txids = [] + while remaining_value > 10*COIN: + remaining_value -= 1*COIN + tx = CTransaction() + tx.vin = [CTxIn(prevout, nSequence=0)] + tx.vout = [CTxOut(remaining_value, CScript([1]))] + tx_hex = txToHex(tx) + txid = self.nodes[0].sendrawtransaction(tx_hex, True) + chain_txids.append(txid) + prevout = COutPoint(int(txid, 16), 0) + + # Whether the double-spend is allowed is evaluated by including all + # child fees - 40 BTC - so this attempt is rejected. + dbl_tx = CTransaction() + dbl_tx.vin = [CTxIn(tx0_outpoint, nSequence=0)] + dbl_tx.vout = [CTxOut(initial_nValue - 30*COIN, CScript([1]))] + dbl_tx_hex = txToHex(dbl_tx) + + try: + self.nodes[0].sendrawtransaction(dbl_tx_hex, True) + except JSONRPCException as exp: + assert_equal(exp.error['code'], -26) # insufficient fee + else: + assert(False) # transaction mistakenly accepted! + + # Accepted with sufficient fee + dbl_tx = CTransaction() + dbl_tx.vin = [CTxIn(tx0_outpoint, nSequence=0)] + dbl_tx.vout = [CTxOut(1*COIN, CScript([1]))] + dbl_tx_hex = txToHex(dbl_tx) + self.nodes[0].sendrawtransaction(dbl_tx_hex, True) + + mempool = self.nodes[0].getrawmempool() + for doublespent_txid in chain_txids: + assert(doublespent_txid not in mempool) + + def test_doublespend_tree(self): + """Doublespend of a big tree of transactions""" + + initial_nValue = 50*COIN + tx0_outpoint = make_utxo(self.nodes[0], initial_nValue) + + def branch(prevout, initial_value, max_txs, tree_width=5, fee=0.0001*COIN, _total_txs=None): + if _total_txs is None: + _total_txs = [0] + if _total_txs[0] >= max_txs: + return + + txout_value = (initial_value - fee) // tree_width + if txout_value < fee: + return + + vout = [CTxOut(txout_value, CScript([i+1])) + for i in range(tree_width)] + tx = CTransaction() + tx.vin = [CTxIn(prevout, nSequence=0)] + tx.vout = vout + tx_hex = txToHex(tx) + + assert(len(tx.serialize()) < 100000) + txid = self.nodes[0].sendrawtransaction(tx_hex, True) + yield tx + _total_txs[0] += 1 + + txid = int(txid, 16) + + for i, txout in enumerate(tx.vout): + for x in branch(COutPoint(txid, i), txout_value, + max_txs, + tree_width=tree_width, fee=fee, + _total_txs=_total_txs): + yield x + + fee = 0.0001*COIN + n = MAX_REPLACEMENT_LIMIT + tree_txs = list(branch(tx0_outpoint, initial_nValue, n, fee=fee)) + assert_equal(len(tree_txs), n) + + # Attempt double-spend, will fail because too little fee paid + dbl_tx = CTransaction() + dbl_tx.vin = [CTxIn(tx0_outpoint, nSequence=0)] + dbl_tx.vout = [CTxOut(initial_nValue - fee*n, CScript([1]))] + dbl_tx_hex = txToHex(dbl_tx) + try: + self.nodes[0].sendrawtransaction(dbl_tx_hex, True) + except JSONRPCException as exp: + assert_equal(exp.error['code'], -26) # insufficient fee + else: + assert(False) + + # 1 BTC fee is enough + dbl_tx = CTransaction() + dbl_tx.vin = [CTxIn(tx0_outpoint, nSequence=0)] + dbl_tx.vout = [CTxOut(initial_nValue - fee*n - 1*COIN, CScript([1]))] + dbl_tx_hex = txToHex(dbl_tx) + self.nodes[0].sendrawtransaction(dbl_tx_hex, True) + + mempool = self.nodes[0].getrawmempool() + + for tx in tree_txs: + tx.rehash() + assert (tx.hash not in mempool) + + # Try again, but with more total transactions than the "max txs + # double-spent at once" anti-DoS limit. + for n in (MAX_REPLACEMENT_LIMIT+1, MAX_REPLACEMENT_LIMIT*2): + fee = 0.0001*COIN + tx0_outpoint = make_utxo(self.nodes[0], initial_nValue) + tree_txs = list(branch(tx0_outpoint, initial_nValue, n, fee=fee)) + assert_equal(len(tree_txs), n) + + dbl_tx = CTransaction() + dbl_tx.vin = [CTxIn(tx0_outpoint, nSequence=0)] + dbl_tx.vout = [CTxOut(initial_nValue - 2*fee*n, CScript([1]))] + dbl_tx_hex = txToHex(dbl_tx) + try: + self.nodes[0].sendrawtransaction(dbl_tx_hex, True) + except JSONRPCException as exp: + assert_equal(exp.error['code'], -26) + assert_equal("too many potential replacements" in exp.error['message'], True) + else: + assert(False) + + for tx in tree_txs: + tx.rehash() + self.nodes[0].getrawtransaction(tx.hash) + + def test_replacement_feeperkb(self): + """Replacement requires fee-per-KB to be higher""" + tx0_outpoint = make_utxo(self.nodes[0], 1.1*COIN) + + tx1a = CTransaction() + tx1a.vin = [CTxIn(tx0_outpoint, nSequence=0)] + tx1a.vout = [CTxOut(1*COIN, CScript([b'a']))] + tx1a_hex = txToHex(tx1a) + tx1a_txid = self.nodes[0].sendrawtransaction(tx1a_hex, True) + + # Higher fee, but the fee per KB is much lower, so the replacement is + # rejected. + tx1b = CTransaction() + tx1b.vin = [CTxIn(tx0_outpoint, nSequence=0)] + tx1b.vout = [CTxOut(0.001*COIN, CScript([b'a'*999000]))] + tx1b_hex = txToHex(tx1b) + + try: + tx1b_txid = self.nodes[0].sendrawtransaction(tx1b_hex, True) + except JSONRPCException as exp: + assert_equal(exp.error['code'], -26) # insufficient fee + else: + assert(False) + + def test_spends_of_conflicting_outputs(self): + """Replacements that spend conflicting tx outputs are rejected""" + utxo1 = make_utxo(self.nodes[0], 1.2*COIN) + utxo2 = make_utxo(self.nodes[0], 3.0*COIN) + + tx1a = CTransaction() + tx1a.vin = [CTxIn(utxo1, nSequence=0)] + tx1a.vout = [CTxOut(1.1*COIN, CScript([b'a']))] + tx1a_hex = txToHex(tx1a) + tx1a_txid = self.nodes[0].sendrawtransaction(tx1a_hex, True) + + tx1a_txid = int(tx1a_txid, 16) + + # Direct spend an output of the transaction we're replacing. + tx2 = CTransaction() + tx2.vin = [CTxIn(utxo1, nSequence=0), CTxIn(utxo2, nSequence=0)] + tx2.vin.append(CTxIn(COutPoint(tx1a_txid, 0), nSequence=0)) + tx2.vout = tx1a.vout + tx2_hex = txToHex(tx2) + + try: + tx2_txid = self.nodes[0].sendrawtransaction(tx2_hex, True) + except JSONRPCException as exp: + assert_equal(exp.error['code'], -26) + else: + assert(False) + + # Spend tx1a's output to test the indirect case. + tx1b = CTransaction() + tx1b.vin = [CTxIn(COutPoint(tx1a_txid, 0), nSequence=0)] + tx1b.vout = [CTxOut(1.0*COIN, CScript([b'a']))] + tx1b_hex = txToHex(tx1b) + tx1b_txid = self.nodes[0].sendrawtransaction(tx1b_hex, True) + tx1b_txid = int(tx1b_txid, 16) + + tx2 = CTransaction() + tx2.vin = [CTxIn(utxo1, nSequence=0), CTxIn(utxo2, nSequence=0), + CTxIn(COutPoint(tx1b_txid, 0))] + tx2.vout = tx1a.vout + tx2_hex = txToHex(tx2) + + try: + tx2_txid = self.nodes[0].sendrawtransaction(tx2_hex, True) + except JSONRPCException as exp: + assert_equal(exp.error['code'], -26) + else: + assert(False) + + def test_new_unconfirmed_inputs(self): + """Replacements that add new unconfirmed inputs are rejected""" + confirmed_utxo = make_utxo(self.nodes[0], 1.1*COIN) + unconfirmed_utxo = make_utxo(self.nodes[0], 0.1*COIN, False) + + tx1 = CTransaction() + tx1.vin = [CTxIn(confirmed_utxo)] + tx1.vout = [CTxOut(1.0*COIN, CScript([b'a']))] + tx1_hex = txToHex(tx1) + tx1_txid = self.nodes[0].sendrawtransaction(tx1_hex, True) + + tx2 = CTransaction() + tx2.vin = [CTxIn(confirmed_utxo), CTxIn(unconfirmed_utxo)] + tx2.vout = tx1.vout + tx2_hex = txToHex(tx2) + + try: + tx2_txid = self.nodes[0].sendrawtransaction(tx2_hex, True) + except JSONRPCException as exp: + assert_equal(exp.error['code'], -26) + else: + assert(False) + + def test_too_many_replacements(self): + """Replacements that evict too many transactions are rejected""" + # Try directly replacing more than MAX_REPLACEMENT_LIMIT + # transactions + + # Start by creating a single transaction with many outputs + initial_nValue = 10*COIN + utxo = make_utxo(self.nodes[0], initial_nValue) + fee = 0.0001*COIN + split_value = int((initial_nValue-fee)/(MAX_REPLACEMENT_LIMIT+1)) + actual_fee = initial_nValue - split_value*(MAX_REPLACEMENT_LIMIT+1) + + outputs = [] + for i in range(MAX_REPLACEMENT_LIMIT+1): + outputs.append(CTxOut(split_value, CScript([1]))) + + splitting_tx = CTransaction() + splitting_tx.vin = [CTxIn(utxo, nSequence=0)] + splitting_tx.vout = outputs + splitting_tx_hex = txToHex(splitting_tx) + + txid = self.nodes[0].sendrawtransaction(splitting_tx_hex, True) + txid = int(txid, 16) + + # Now spend each of those outputs individually + for i in range(MAX_REPLACEMENT_LIMIT+1): + tx_i = CTransaction() + tx_i.vin = [CTxIn(COutPoint(txid, i), nSequence=0)] + tx_i.vout = [CTxOut(split_value-fee, CScript([b'a']))] + tx_i_hex = txToHex(tx_i) + self.nodes[0].sendrawtransaction(tx_i_hex, True) + + # Now create doublespend of the whole lot; should fail. + # Need a big enough fee to cover all spending transactions and have + # a higher fee rate + double_spend_value = (split_value-100*fee)*(MAX_REPLACEMENT_LIMIT+1) + inputs = [] + for i in range(MAX_REPLACEMENT_LIMIT+1): + inputs.append(CTxIn(COutPoint(txid, i), nSequence=0)) + double_tx = CTransaction() + double_tx.vin = inputs + double_tx.vout = [CTxOut(double_spend_value, CScript([b'a']))] + double_tx_hex = txToHex(double_tx) + + try: + self.nodes[0].sendrawtransaction(double_tx_hex, True) + except JSONRPCException as exp: + assert_equal(exp.error['code'], -26) + assert_equal("too many potential replacements" in exp.error['message'], True) + else: + assert(False) + + # If we remove an input, it should pass + double_tx = CTransaction() + double_tx.vin = inputs[0:-1] + double_tx.vout = [CTxOut(double_spend_value, CScript([b'a']))] + double_tx_hex = txToHex(double_tx) + self.nodes[0].sendrawtransaction(double_tx_hex, True) + + def test_opt_in(self): + """ Replacing should only work if orig tx opted in """ + tx0_outpoint = make_utxo(self.nodes[0], 1.1*COIN) + + # Create a non-opting in transaction + tx1a = CTransaction() + tx1a.vin = [CTxIn(tx0_outpoint, nSequence=0xffffffff)] + tx1a.vout = [CTxOut(1*COIN, CScript([b'a']))] + tx1a_hex = txToHex(tx1a) + tx1a_txid = self.nodes[0].sendrawtransaction(tx1a_hex, True) + + # Shouldn't be able to double-spend + tx1b = CTransaction() + tx1b.vin = [CTxIn(tx0_outpoint, nSequence=0)] + tx1b.vout = [CTxOut(0.9*COIN, CScript([b'b']))] + tx1b_hex = txToHex(tx1b) + + try: + tx1b_txid = self.nodes[0].sendrawtransaction(tx1b_hex, True) + except JSONRPCException as exp: + assert_equal(exp.error['code'], -26) + else: + print tx1b_txid + assert(False) + + tx1_outpoint = make_utxo(self.nodes[0], 1.1*COIN) + + # Create a different non-opting in transaction + tx2a = CTransaction() + tx2a.vin = [CTxIn(tx1_outpoint, nSequence=0xfffffffe)] + tx2a.vout = [CTxOut(1*COIN, CScript([b'a']))] + tx2a_hex = txToHex(tx2a) + tx2a_txid = self.nodes[0].sendrawtransaction(tx2a_hex, True) + + # Still shouldn't be able to double-spend + tx2b = CTransaction() + tx2b.vin = [CTxIn(tx1_outpoint, nSequence=0)] + tx2b.vout = [CTxOut(0.9*COIN, CScript([b'b']))] + tx2b_hex = txToHex(tx2b) + + try: + tx2b_txid = self.nodes[0].sendrawtransaction(tx2b_hex, True) + except JSONRPCException as exp: + assert_equal(exp.error['code'], -26) + else: + assert(False) + + # Now create a new transaction that spends from tx1a and tx2a + # opt-in on one of the inputs + # Transaction should be replaceable on either input + + tx1a_txid = int(tx1a_txid, 16) + tx2a_txid = int(tx2a_txid, 16) + + tx3a = CTransaction() + tx3a.vin = [CTxIn(COutPoint(tx1a_txid, 0), nSequence=0xffffffff), + CTxIn(COutPoint(tx2a_txid, 0), nSequence=0xfffffffd)] + tx3a.vout = [CTxOut(0.9*COIN, CScript([b'c'])), CTxOut(0.9*COIN, CScript([b'd']))] + tx3a_hex = txToHex(tx3a) + + self.nodes[0].sendrawtransaction(tx3a_hex, True) + + tx3b = CTransaction() + tx3b.vin = [CTxIn(COutPoint(tx1a_txid, 0), nSequence=0)] + tx3b.vout = [CTxOut(0.5*COIN, CScript([b'e']))] + tx3b_hex = txToHex(tx3b) + + tx3c = CTransaction() + tx3c.vin = [CTxIn(COutPoint(tx2a_txid, 0), nSequence=0)] + tx3c.vout = [CTxOut(0.5*COIN, CScript([b'f']))] + tx3c_hex = txToHex(tx3c) + + self.nodes[0].sendrawtransaction(tx3b_hex, True) + # If tx3b was accepted, tx3c won't look like a replacement, + # but make sure it is accepted anyway + self.nodes[0].sendrawtransaction(tx3c_hex, True) + +if __name__ == '__main__': + ReplaceByFeeTest().main() diff --git a/src/main.cpp b/src/main.cpp index b0b58141a2..e48d0a6d43 100644 --- a/src/main.cpp +++ b/src/main.cpp @@ -832,15 +832,42 @@ bool AcceptToMemoryPool(CTxMemPool& pool, CValidationState &state, const CTransa return state.Invalid(false, REJECT_ALREADY_KNOWN, "txn-already-in-mempool"); // Check for conflicts with in-memory transactions + set<uint256> setConflicts; { LOCK(pool.cs); // protect pool.mapNextTx - for (unsigned int i = 0; i < tx.vin.size(); i++) + BOOST_FOREACH(const CTxIn &txin, tx.vin) { - COutPoint outpoint = tx.vin[i].prevout; - if (pool.mapNextTx.count(outpoint)) + if (pool.mapNextTx.count(txin.prevout)) { - // Disable replacement feature for now - return state.Invalid(false, REJECT_CONFLICT, "txn-mempool-conflict"); + const CTransaction *ptxConflicting = pool.mapNextTx[txin.prevout].ptx; + if (!setConflicts.count(ptxConflicting->GetHash())) + { + // Allow opt-out of transaction replacement by setting + // nSequence >= maxint-1 on all inputs. + // + // maxint-1 is picked to still allow use of nLockTime by + // non-replacable transactions. All inputs rather than just one + // is for the sake of multi-party protocols, where we don't + // want a single party to be able to disable replacement. + // + // The opt-out ignores descendants as anyone relying on + // first-seen mempool behavior should be checking all + // unconfirmed ancestors anyway; doing otherwise is hopelessly + // insecure. + bool fReplacementOptOut = true; + BOOST_FOREACH(const CTxIn &txin, ptxConflicting->vin) + { + if (txin.nSequence < std::numeric_limits<unsigned int>::max()-1) + { + fReplacementOptOut = false; + break; + } + } + if (fReplacementOptOut) + return state.Invalid(false, REJECT_CONFLICT, "txn-mempool-conflict"); + + setConflicts.insert(ptxConflicting->GetHash()); + } } } } @@ -958,6 +985,160 @@ bool AcceptToMemoryPool(CTxMemPool& pool, CValidationState &state, const CTransa return state.DoS(0, false, REJECT_NONSTANDARD, "too-long-mempool-chain", false, errString); } + // A transaction that spends outputs that would be replaced by it is invalid. Now + // that we have the set of all ancestors we can detect this + // pathological case by making sure setConflicts and setAncestors don't + // intersect. + BOOST_FOREACH(CTxMemPool::txiter ancestorIt, setAncestors) + { + const uint256 &hashAncestor = ancestorIt->GetTx().GetHash(); + if (setConflicts.count(hashAncestor)) + { + return state.DoS(10, error("AcceptToMemoryPool: %s spends conflicting transaction %s", + hash.ToString(), + hashAncestor.ToString()), + REJECT_INVALID, "bad-txns-spends-conflicting-tx"); + } + } + + // Check if it's economically rational to mine this transaction rather + // than the ones it replaces. + CAmount nConflictingFees = 0; + size_t nConflictingSize = 0; + uint64_t nConflictingCount = 0; + CTxMemPool::setEntries allConflicting; + + // If we don't hold the lock allConflicting might be incomplete; the + // subsequent RemoveStaged() and addUnchecked() calls don't guarantee + // mempool consistency for us. + LOCK(pool.cs); + if (setConflicts.size()) + { + CFeeRate newFeeRate(nFees, nSize); + set<uint256> setConflictsParents; + const int maxDescendantsToVisit = 100; + CTxMemPool::setEntries setIterConflicting; + BOOST_FOREACH(const uint256 &hashConflicting, setConflicts) + { + CTxMemPool::txiter mi = pool.mapTx.find(hashConflicting); + if (mi == pool.mapTx.end()) + continue; + + // Save these to avoid repeated lookups + setIterConflicting.insert(mi); + + // If this entry is "dirty", then we don't have descendant + // state for this transaction, which means we probably have + // lots of in-mempool descendants. + // Don't allow replacements of dirty transactions, to ensure + // that we don't spend too much time walking descendants. + // This should be rare. + if (mi->IsDirty()) { + return state.DoS(0, + error("AcceptToMemoryPool: rejecting replacement %s; cannot replace tx %s with untracked descendants", + hash.ToString(), + mi->GetTx().GetHash().ToString()), + REJECT_NONSTANDARD, "too many potential replacements"); + } + + // Don't allow the replacement to reduce the feerate of the + // mempool. + // + // We usually don't want to accept replacements with lower + // feerates than what they replaced as that would lower the + // feerate of the next block. Requiring that the feerate always + // be increased is also an easy-to-reason about way to prevent + // DoS attacks via replacements. + // + // The mining code doesn't (currently) take children into + // account (CPFP) so we only consider the feerates of + // transactions being directly replaced, not their indirect + // descendants. While that does mean high feerate children are + // ignored when deciding whether or not to replace, we do + // require the replacement to pay more overall fees too, + // mitigating most cases. + CFeeRate oldFeeRate(mi->GetFee(), mi->GetTxSize()); + if (newFeeRate <= oldFeeRate) + { + return state.DoS(0, + error("AcceptToMemoryPool: rejecting replacement %s; new feerate %s <= old feerate %s", + hash.ToString(), + newFeeRate.ToString(), + oldFeeRate.ToString()), + REJECT_INSUFFICIENTFEE, "insufficient fee"); + } + + BOOST_FOREACH(const CTxIn &txin, mi->GetTx().vin) + { + setConflictsParents.insert(txin.prevout.hash); + } + + nConflictingCount += mi->GetCountWithDescendants(); + } + // This potentially overestimates the number of actual descendants + // but we just want to be conservative to avoid doing too much + // work. + if (nConflictingCount <= maxDescendantsToVisit) { + // If not too many to replace, then calculate the set of + // transactions that would have to be evicted + BOOST_FOREACH(CTxMemPool::txiter it, setIterConflicting) { + pool.CalculateDescendants(it, allConflicting); + } + BOOST_FOREACH(CTxMemPool::txiter it, allConflicting) { + nConflictingFees += it->GetFee(); + nConflictingSize += it->GetTxSize(); + } + } else { + return state.DoS(0, + error("AcceptToMemoryPool: rejecting replacement %s; too many potential replacements (%d > %d)\n", + hash.ToString(), + nConflictingCount, + maxDescendantsToVisit), + REJECT_NONSTANDARD, "too many potential replacements"); + } + + for (unsigned int j = 0; j < tx.vin.size(); j++) + { + // We don't want to accept replacements that require low + // feerate junk to be mined first. Ideally we'd keep track of + // the ancestor feerates and make the decision based on that, + // but for now requiring all new inputs to be confirmed works. + if (!setConflictsParents.count(tx.vin[j].prevout.hash)) + { + // Rather than check the UTXO set - potentially expensive - + // it's cheaper to just check if the new input refers to a + // tx that's in the mempool. + if (pool.mapTx.find(tx.vin[j].prevout.hash) != pool.mapTx.end()) + return state.DoS(0, error("AcceptToMemoryPool: replacement %s adds unconfirmed input, idx %d", + hash.ToString(), j), + REJECT_NONSTANDARD, "replacement-adds-unconfirmed"); + } + } + + // The replacement must pay greater fees than the transactions it + // replaces - if we did the bandwidth used by those conflicting + // transactions would not be paid for. + if (nFees < nConflictingFees) + { + return state.DoS(0, error("AcceptToMemoryPool: rejecting replacement %s, less fees than conflicting txs; %s < %s", + hash.ToString(), FormatMoney(nFees), FormatMoney(nConflictingFees)), + REJECT_INSUFFICIENTFEE, "insufficient fee"); + } + + // Finally in addition to paying more fees than the conflicts the + // new transaction must pay for its own bandwidth. + CAmount nDeltaFees = nFees - nConflictingFees; + if (nDeltaFees < ::minRelayTxFee.GetFee(nSize)) + { + return state.DoS(0, + error("AcceptToMemoryPool: rejecting replacement %s, not enough additional fees to relay; %s < %s", + hash.ToString(), + FormatMoney(nDeltaFees), + FormatMoney(::minRelayTxFee.GetFee(nSize))), + REJECT_INSUFFICIENTFEE, "insufficient fee"); + } + } + // 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)) @@ -978,6 +1159,17 @@ bool AcceptToMemoryPool(CTxMemPool& pool, CValidationState &state, const CTransa __func__, hash.ToString(), FormatStateMessage(state)); } + // Remove conflicting transactions from the mempool + BOOST_FOREACH(const CTxMemPool::txiter it, allConflicting) + { + LogPrint("mempool", "replacing tx %s with %s for %s BTC additional fees, %d delta bytes\n", + it->GetTx().GetHash().ToString(), + hash.ToString(), + FormatMoney(nFees - nConflictingFees), + (int)nSize - (int)nConflictingSize); + } + pool.RemoveStaged(allConflicting); + // Store transaction in memory pool.addUnchecked(hash, entry, setAncestors, !IsInitialBlockDownload()); diff --git a/src/txmempool.h b/src/txmempool.h index 5d8231fb77..7f43120f7f 100644 --- a/src/txmempool.h +++ b/src/txmempool.h @@ -420,6 +420,11 @@ public: */ bool CalculateMemPoolAncestors(const CTxMemPoolEntry &entry, setEntries &setAncestors, uint64_t limitAncestorCount, uint64_t limitAncestorSize, uint64_t limitDescendantCount, uint64_t limitDescendantSize, std::string &errString, bool fSearchForParents = true); + /** Populate setDescendants with all in-mempool descendants of hash. + * Assumes that setDescendants includes all in-mempool descendants of anything + * already in it. */ + void CalculateDescendants(txiter it, setEntries &setDescendants); + /** The minimum fee to get into the mempool, which may itself not be enough * for larger-sized transactions. * The minReasonableRelayFee constructor arg is used to bound the time it @@ -505,10 +510,6 @@ private: void UpdateForRemoveFromMempool(const setEntries &entriesToRemove); /** Sever link between specified transaction and direct children. */ void UpdateChildrenForRemoval(txiter entry); - /** Populate setDescendants with all in-mempool descendants of hash. - * Assumes that setDescendants includes all in-mempool descendants of anything - * already in it. */ - void CalculateDescendants(txiter it, setEntries &setDescendants); /** Before calling removeUnchecked for a given transaction, * UpdateForRemoveFromMempool must be called on the entire (dependent) set |