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Reject replacements that add new unconfirmed inputs

tags/v0.15.1
Peter Todd 5 years ago
parent
commit
b272ecfdb3
2 changed files with 59 additions and 4 deletions
  1. 35
    4
      qa/replace-by-fee/rbf-tests.py
  2. 24
    0
      src/main.cpp

+ 35
- 4
qa/replace-by-fee/rbf-tests.py View File

@@ -35,11 +35,11 @@ class Test_ReplaceByFee(unittest.TestCase):
cls.proxy = bitcoin.rpc.Proxy()

@classmethod
def tearDownClass(cls):
# Make sure mining works
def mine_mempool(cls):
"""Mine until mempool is empty"""
mempool_size = 1
while mempool_size:
cls.proxy.call('generate',1)
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
@@ -47,10 +47,18 @@ class Test_ReplaceByFee(unittest.TestCase):
assert(new_mempool_size != mempool_size)
mempool_size = new_mempool_size

def make_txout(self, amount, scriptPubKey=CScript([1])):
@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:
@@ -72,6 +80,10 @@ class Test_ReplaceByFee(unittest.TestCase):

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):
@@ -276,5 +288,24 @@ class Test_ReplaceByFee(unittest.TestCase):
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()

if __name__ == '__main__':
unittest.main()

+ 24
- 0
src/main.cpp View File

@@ -1009,6 +1009,7 @@ bool AcceptToMemoryPool(CTxMemPool& pool, CValidationState &state, const CTransa
LOCK(pool.cs);

CFeeRate newFeeRate(nFees, nSize);
set<uint256> setConflictsParents;
BOOST_FOREACH(const uint256 hashConflicting, setConflicts)
{
CTxMemPool::txiter mi = pool.mapTx.find(hashConflicting);
@@ -1042,6 +1043,11 @@ bool AcceptToMemoryPool(CTxMemPool& pool, CValidationState &state, const CTransa
REJECT_INSUFFICIENTFEE, "insufficient fee");
}

BOOST_FOREACH(const CTxIn &txin, mi->GetTx().vin)
{
setConflictsParents.insert(txin.prevout.hash);
}

// For efficiency we simply sum up the pre-calculated
// fees/size-with-descendants values from the mempool package
// tracking; this does mean the pathological case of diamond tx
@@ -1050,6 +1056,24 @@ bool AcceptToMemoryPool(CTxMemPool& pool, CValidationState &state, const CTransa
nConflictingSize += mi->GetSizeWithDescendants();
}

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.

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