Auto merge of #2342 - bitcartel:1081__mempoolpatch, r=str4d

Add ability for node to reject tx from mempool by number of tx inputs

Implement short-term solution described in #2343 so that users can respond promptly to critical short-term problems caused by quadratic validation scaling, such as the getblocktemplate latency, block propagation latency, and mempool size inflation issues described in #2333.

qa/pull-tester/rpc-tests.sh

@@ -26,6 +26,7 @@ testScripts=(
     'rest.py'
     'mempool_spendcoinbase.py'
     'mempool_coinbase_spends.py'
+    'mempool_tx_input_limit.py'
     'httpbasics.py'
     'zapwallettxes.py'
     'proxy_test.py'

qa/rpc-tests/mempool_tx_input_limit.py

@@ -0,0 +1,152 @@
+#!/usr/bin/env python2
+# Copyright (c) 2017 The Zcash developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+from test_framework.test_framework import BitcoinTestFramework
+from test_framework.util import *
+import os
+import shutil
+from time import sleep
+
+# Test -mempooltxinputlimit
+class MempoolTxInputLimitTest(BitcoinTestFramework):
+
+    alert_filename = None  # Set by setup_network
+
+    def setup_network(self):
+        args = ["-checkmempool", "-debug=mempool", "-mempooltxinputlimit=2"]
+        self.nodes = []
+        self.nodes.append(start_node(0, self.options.tmpdir, args))
+        self.nodes.append(start_node(1, self.options.tmpdir, args))
+        connect_nodes(self.nodes[1], 0)
+        self.is_network_split = False
+        self.sync_all
+
+    def setup_chain(self):
+        print "Initializing test directory "+self.options.tmpdir
+        initialize_chain_clean(self.options.tmpdir, 2)
+
+    def call_z_sendmany(self, from_addr, to_addr, amount):
+        recipients = []
+        recipients.append({"address": to_addr, "amount": amount})
+        myopid = self.nodes[0].z_sendmany(from_addr, recipients)
+        return self.wait_and_assert_operationid_status(myopid)
+
+    def wait_and_assert_operationid_status(self, myopid, in_status='success', in_errormsg=None):
+        print('waiting for async operation {}'.format(myopid))
+        opids = []
+        opids.append(myopid)
+        timeout = 300
+        status = None
+        errormsg = None
+        txid = None
+        for x in xrange(1, timeout):
+            results = self.nodes[0].z_getoperationresult(opids)
+            if len(results)==0:
+                sleep(1)
+            else:
+                status = results[0]["status"]
+                if status == "failed":
+                    errormsg = results[0]['error']['message']
+                elif status == "success":
+                    txid = results[0]['result']['txid']
+                break
+        print('...returned status: {}'.format(status))
+        assert_equal(in_status, status)
+        if errormsg is not None:
+            assert(in_errormsg is not None)
+            assert_equal(in_errormsg in errormsg, True)
+            print('...returned error: {}'.format(errormsg))
+        return txid
+
+    def run_test(self):
+        start_count = self.nodes[0].getblockcount()
+
+        self.nodes[0].generate(100)
+        self.sync_all()
+        # Mine three blocks. After this, nodes[0] blocks
+        # 1, 2, and 3 are spend-able.
+        self.nodes[1].generate(3)
+        self.sync_all()
+
+        # Check 1: z_sendmany is limited by -mempooltxinputlimit
+
+        # Add zaddr to node 0
+        node0_zaddr = self.nodes[0].z_getnewaddress()
+
+        # Send three inputs from node 0 taddr to zaddr to get out of coinbase
+        node0_taddr = self.nodes[0].getnewaddress();
+        recipients = []
+        recipients.append({"address":node0_zaddr, "amount":Decimal('30.0')-Decimal('0.0001')}) # utxo amount less fee
+        myopid = self.nodes[0].z_sendmany(node0_taddr, recipients)
+
+        opids = []
+        opids.append(myopid)
+
+        # Spend should fail due to -mempooltxinputlimit
+        timeout = 120
+        status = None
+        for x in xrange(1, timeout):
+            results = self.nodes[0].z_getoperationresult(opids)
+            if len(results)==0:
+                sleep(1)
+            else:
+                status = results[0]["status"]
+                msg = results[0]["error"]["message"]
+                assert_equal("failed", status)
+                assert_equal("Too many transparent inputs 3 > limit 2", msg)
+                break
+
+        # Mempool should be empty.
+        assert_equal(set(self.nodes[0].getrawmempool()), set())
+
+        # Reduce amount to only use two inputs
+        spend_zaddr_amount = Decimal('20.0') - Decimal('0.0001')
+        spend_zaddr_id = self.call_z_sendmany(node0_taddr, node0_zaddr, spend_zaddr_amount) # utxo amount less fee
+        self.sync_all()
+
+        # Spend should be in the mempool
+        assert_equal(set(self.nodes[0].getrawmempool()), set([ spend_zaddr_id ]))
+
+        self.nodes[0].generate(1)
+        self.sync_all()
+
+        # mempool should be empty.
+        assert_equal(set(self.nodes[0].getrawmempool()), set())
+
+        # Check 2: sendfrom is limited by -mempooltxinputlimit
+        node1_taddr = self.nodes[1].getnewaddress();
+        recipients = []
+        spend_taddr_amount = spend_zaddr_amount - Decimal('0.0001')
+        spend_taddr_output = Decimal('8')
+
+        # Create three outputs
+        recipients.append({"address":self.nodes[1].getnewaddress(), "amount": spend_taddr_output})
+        recipients.append({"address":self.nodes[1].getnewaddress(), "amount": spend_taddr_output})
+        recipients.append({"address":self.nodes[1].getnewaddress(), "amount": spend_taddr_amount - spend_taddr_output - spend_taddr_output})
+
+        myopid = self.nodes[0].z_sendmany(node0_zaddr, recipients)
+        self.wait_and_assert_operationid_status(myopid)
+        self.nodes[1].generate(1)
+        self.sync_all()
+
+        # Should use three UTXOs and fail
+        try:
+            self.nodes[1].sendfrom("", node0_taddr, spend_taddr_amount - Decimal('1'))
+            assert(False)
+        except JSONRPCException,e:
+            msg = e.error['message']
+            assert_equal("Too many transparent inputs 3 > limit 2", msg)
+
+        # mempool should be empty.
+        assert_equal(set(self.nodes[1].getrawmempool()), set())
+
+        # Should use two UTXOs and succeed
+        spend_taddr_id2 = self.nodes[1].sendfrom("", node0_taddr, spend_taddr_output + spend_taddr_output - Decimal('1'))
+
+        # Spend should be in the mempool
+        assert_equal(set(self.nodes[1].getrawmempool()), set([ spend_taddr_id2 ]))
+
+if __name__ == '__main__':
+    MempoolTxInputLimitTest().main()