6 files changed, 667 insertions, 0 deletions
diff --git a/qa/pull-tester/rpc-tests.sh b/qa/pull-tester/rpc-tests.sh
index 6d57d58755..ae27a94b8d 100755
--- a/qa/pull-tester/rpc-tests.sh
+++ b/qa/pull-tester/rpc-tests.sh
@@ -31,6 +31,7 @@ testScripts=(
     'merkle_blocks.py'
 #    'forknotify.py'
     'maxblocksinflight.py'
+    'invalidblockrequest.py'
 );
 if [ "x${ENABLE_BITCOIND}${ENABLE_UTILS}${ENABLE_WALLET}" = "x111" ]; then
     for (( i = 0; i < ${#testScripts[@]}; i++ ))
diff --git a/qa/rpc-tests/blockstore.py b/qa/rpc-tests/blockstore.py
new file mode 100644
index 0000000000..c57b6df81b
--- /dev/null
+++ b/qa/rpc-tests/blockstore.py
@@ -0,0 +1,127 @@
+# BlockStore: a helper class that keeps a map of blocks and implements
+#             helper functions for responding to getheaders and getdata,
+#             and for constructing a getheaders message
+#
+
+from mininode import *
+import dbm
+
+class BlockStore(object):
+    def __init__(self, datadir):
+        self.blockDB = dbm.open(datadir + "/blocks", 'c')
+        self.currentBlock = 0L
+    
+    def close(self):
+        self.blockDB.close()
+
+    def get(self, blockhash):
+        serialized_block = None
+        try:
+            serialized_block = self.blockDB[repr(blockhash)]
+        except KeyError:
+            return None
+        f = cStringIO.StringIO(serialized_block)
+        ret = CBlock()
+        ret.deserialize(f)
+        ret.calc_sha256()
+        return ret
+
+    # Note: this pulls full blocks out of the database just to retrieve
+    # the headers -- perhaps we could keep a separate data structure
+    # to avoid this overhead.
+    def headers_for(self, locator, hash_stop, current_tip=None):
+        if current_tip is None:
+            current_tip = self.currentBlock
+        current_block = self.get(current_tip)
+        if current_block is None:
+            return None
+
+        response = msg_headers()
+        headersList = [ CBlockHeader(current_block) ]
+        maxheaders = 2000
+        while (headersList[0].sha256 not in locator.vHave):
+            prevBlockHash = headersList[0].hashPrevBlock
+            prevBlock = self.get(prevBlockHash)
+            if prevBlock is not None:
+                headersList.insert(0, CBlockHeader(prevBlock))
+            else:
+                break
+        headersList = headersList[:maxheaders] # truncate if we have too many
+        hashList = [x.sha256 for x in headersList]
+        index = len(headersList)
+        if (hash_stop in hashList):
+            index = hashList.index(hash_stop)+1
+        response.headers = headersList[:index]
+        return response
+
+    def add_block(self, block):
+        block.calc_sha256()
+        try:
+            self.blockDB[repr(block.sha256)] = bytes(block.serialize())
+        except TypeError as e:
+            print "Unexpected error: ", sys.exc_info()[0], e.args
+        self.currentBlock = block.sha256
+
+    def get_blocks(self, inv):
+        responses = []
+        for i in inv:
+            if (i.type == 2): # MSG_BLOCK
+                block = self.get(i.hash)
+                if block is not None:
+                    responses.append(msg_block(block))
+        return responses
+
+    def get_locator(self, current_tip=None):
+        if current_tip is None:
+            current_tip = self.currentBlock
+        r = []
+        counter = 0
+        step = 1
+        lastBlock = self.get(current_tip)
+        while lastBlock is not None:
+            r.append(lastBlock.hashPrevBlock)
+            for i in range(step):
+                lastBlock = self.get(lastBlock.hashPrevBlock)
+                if lastBlock is None:
+                    break
+            counter += 1
+            if counter > 10:
+                step *= 2
+        locator = CBlockLocator()
+        locator.vHave = r
+        return locator
+
+class TxStore(object):
+    def __init__(self, datadir):
+        self.txDB = dbm.open(datadir + "/transactions", 'c')
+
+    def close(self):
+        self.txDB.close()
+
+    def get(self, txhash):
+        serialized_tx = None
+        try:
+            serialized_tx = self.txDB[repr(txhash)]
+        except KeyError:
+            return None
+        f = cStringIO.StringIO(serialized_tx)
+        ret = CTransaction()
+        ret.deserialize(f)
+        ret.calc_sha256()
+        return ret
+
+    def add_transaction(self, tx):
+        tx.calc_sha256()
+        try:
+            self.txDB[repr(tx.sha256)] = bytes(tx.serialize())
+        except TypeError as e:
+            print "Unexpected error: ", sys.exc_info()[0], e.args
+
+    def get_transactions(self, inv):
+        responses = []
+        for i in inv:
+            if (i.type == 1): # MSG_TX
+                tx = self.get(i.hash)
+                if tx is not None:
+                    responses.append(msg_tx(tx))
+        return responses
diff --git a/qa/rpc-tests/blocktools.py b/qa/rpc-tests/blocktools.py
new file mode 100644
index 0000000000..f397fe7cd6
--- /dev/null
+++ b/qa/rpc-tests/blocktools.py
@@ -0,0 +1,65 @@
+# blocktools.py - utilities for manipulating blocks and transactions
+#
+# Distributed under the MIT/X11 software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+#
+
+from mininode import *
+from script import CScript, CScriptOp
+
+# Create a block (with regtest difficulty)
+def create_block(hashprev, coinbase, nTime=None):
+    block = CBlock()
+    if nTime is None:
+        import time
+        block.nTime = int(time.time()+600)
+    else:
+        block.nTime = nTime
+    block.hashPrevBlock = hashprev
+    block.nBits = 0x207fffff # Will break after a difficulty adjustment...
+    block.vtx.append(coinbase)
+    block.hashMerkleRoot = block.calc_merkle_root()
+    block.calc_sha256()
+    return block
+
+def serialize_script_num(value):
+    r = bytearray(0)
+    if value == 0:
+        return r
+    neg = value < 0
+    absvalue = -value if neg else value
+    while (absvalue):
+        r.append(chr(absvalue & 0xff))
+        absvalue >>= 8
+    if r[-1] & 0x80:
+        r.append(0x80 if neg else 0)
+    elif neg:
+        r[-1] |= 0x80
+    return r
+
+counter=1
+# Create an anyone-can-spend coinbase transaction, assuming no miner fees
+def create_coinbase(heightAdjust = 0):
+    global counter
+    coinbase = CTransaction()
+    coinbase.vin.append(CTxIn(COutPoint(0, 0xffffffff), 
+                ser_string(serialize_script_num(counter+heightAdjust)), 0xffffffff))
+    counter += 1
+    coinbaseoutput = CTxOut()
+    coinbaseoutput.nValue = 50*100000000
+    halvings = int((counter+heightAdjust)/150) # regtest
+    coinbaseoutput.nValue >>= halvings
+    coinbaseoutput.scriptPubKey = ""
+    coinbase.vout = [ coinbaseoutput ]
+    coinbase.calc_sha256()
+    return coinbase
+
+# Create a transaction with an anyone-can-spend output, that spends the
+# nth output of prevtx.
+def create_transaction(prevtx, n, sig, value):
+    tx = CTransaction()
+    assert(n < len(prevtx.vout))
+    tx.vin.append(CTxIn(COutPoint(prevtx.sha256, n), sig, 0xffffffff))
+    tx.vout.append(CTxOut(value, ""))
+    tx.calc_sha256()
+    return tx
diff --git a/qa/rpc-tests/comptool.py b/qa/rpc-tests/comptool.py
new file mode 100755
index 0000000000..6125bae51e
--- /dev/null
+++ b/qa/rpc-tests/comptool.py
@@ -0,0 +1,330 @@
+#!/usr/bin/env python2
+#
+# Distributed under the MIT/X11 software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+#
+
+from mininode import *
+from blockstore import BlockStore, TxStore
+from util import p2p_port
+
+'''
+This is a tool for comparing two or more bitcoinds to each other
+using a script provided.
+
+To use, create a class that implements get_tests(), and pass it in
+as the test generator to TestManager.  get_tests() should be a python
+generator that returns TestInstance objects.  See below for definition.
+'''
+
+# TestNode behaves as follows:
+# Configure with a BlockStore and TxStore
+# on_inv: log the message but don't request
+# on_headers: log the chain tip
+# on_pong: update ping response map (for synchronization)
+# on_getheaders: provide headers via BlockStore
+# on_getdata: provide blocks via BlockStore
+
+class TestNode(NodeConnCB):
+
+    def __init__(self, block_store, tx_store):
+        NodeConnCB.__init__(self)
+        self.create_callback_map()
+        self.conn = None
+        self.bestblockhash = None
+        self.block_store = block_store
+        self.block_request_map = {}
+        self.tx_store = tx_store
+        self.tx_request_map = {}
+
+        # When the pingmap is non-empty we're waiting for 
+        # a response
+        self.pingMap = {} 
+        self.lastInv = []
+
+    def add_connection(self, conn):
+        self.conn = conn
+
+    def on_headers(self, conn, message):
+        if len(message.headers) > 0:
+            best_header = message.headers[-1]
+            best_header.calc_sha256()
+            self.bestblockhash = best_header.sha256
+
+    def on_getheaders(self, conn, message):
+        response = self.block_store.headers_for(message.locator, message.hashstop)
+        if response is not None:
+            conn.send_message(response)
+
+    def on_getdata(self, conn, message):
+        [conn.send_message(r) for r in self.block_store.get_blocks(message.inv)]
+        [conn.send_message(r) for r in self.tx_store.get_transactions(message.inv)]
+
+        for i in message.inv:
+            if i.type == 1:
+                self.tx_request_map[i.hash] = True
+            elif i.type == 2:
+                self.block_request_map[i.hash] = True
+
+    def on_inv(self, conn, message):
+        self.lastInv = [x.hash for x in message.inv]
+
+    def on_pong(self, conn, message):
+        try:
+            del self.pingMap[message.nonce]
+        except KeyError:
+            raise AssertionError("Got pong for unknown ping [%s]" % repr(message))
+
+    def send_inv(self, obj):
+        mtype = 2 if isinstance(obj, CBlock) else 1
+        self.conn.send_message(msg_inv([CInv(mtype, obj.sha256)]))
+
+    def send_getheaders(self):
+        # We ask for headers from their last tip.
+        m = msg_getheaders()
+        m.locator = self.block_store.get_locator(self.bestblockhash)
+        self.conn.send_message(m)
+
+    # This assumes BIP31
+    def send_ping(self, nonce):
+        self.pingMap[nonce] = True
+        self.conn.send_message(msg_ping(nonce))
+
+    def received_ping_response(self, nonce):
+        return nonce not in self.pingMap
+
+    def send_mempool(self):
+        self.lastInv = []
+        self.conn.send_message(msg_mempool())
+
+# TestInstance:
+#
+# Instances of these are generated by the test generator, and fed into the
+# comptool.
+#
+# "blocks_and_transactions" should be an array of [obj, True/False/None]:
+#  - obj is either a CBlock or a CTransaction, and 
+#  - the second value indicates whether the object should be accepted
+#    into the blockchain or mempool (for tests where we expect a certain
+#    answer), or "None" if we don't expect a certain answer and are just
+#    comparing the behavior of the nodes being tested.
+# sync_every_block: if True, then each block will be inv'ed, synced, and
+#    nodes will be tested based on the outcome for the block.  If False,
+#    then inv's accumulate until all blocks are processed (or max inv size
+#    is reached) and then sent out in one inv message.  Then the final block
+#    will be synced across all connections, and the outcome of the final 
+#    block will be tested.
+# sync_every_tx: analagous to behavior for sync_every_block, except if outcome
+#    on the final tx is None, then contents of entire mempool are compared
+#    across all connections.  (If outcome of final tx is specified as true
+#    or false, then only the last tx is tested against outcome.)
+
+class TestInstance(object):
+    def __init__(self, objects=[], sync_every_block=True, sync_every_tx=False):
+        self.blocks_and_transactions = objects
+        self.sync_every_block = sync_every_block
+        self.sync_every_tx = sync_every_tx
+
+class TestManager(object):
+
+    def __init__(self, testgen, datadir):
+        self.test_generator = testgen
+        self.connections    = []
+        self.block_store    = BlockStore(datadir)
+        self.tx_store       = TxStore(datadir)
+        self.ping_counter   = 1
+
+    def add_all_connections(self, nodes):
+        for i in range(len(nodes)):
+            # Create a p2p connection to each node
+            self.connections.append(NodeConn('127.0.0.1', p2p_port(i), 
+                        nodes[i], TestNode(self.block_store, self.tx_store)))
+            # Make sure the TestNode (callback class) has a reference to its
+            # associated NodeConn
+            self.connections[-1].cb.add_connection(self.connections[-1])
+
+    def wait_for_verack(self):
+        sleep_time = 0.05
+        max_tries = 10 / sleep_time  # Wait at most 10 seconds
+        while max_tries > 0:
+            done = True
+            for c in self.connections:
+                if c.cb.verack_received is False:
+                    done = False
+                    break
+            if done:
+                break
+            time.sleep(sleep_time)
+
+    def wait_for_pings(self, counter):
+        received_pongs = False
+        while received_pongs is not True:
+            time.sleep(0.05)
+            received_pongs = True
+            for c in self.connections:
+                if c.cb.received_ping_response(counter) is not True:
+                    received_pongs = False
+                    break
+
+    # sync_blocks: Wait for all connections to request the blockhash given
+    # then send get_headers to find out the tip of each node, and synchronize
+    # the response by using a ping (and waiting for pong with same nonce).
+    def sync_blocks(self, blockhash, num_blocks):
+        # Wait for nodes to request block (50ms sleep * 20 tries * num_blocks)
+        max_tries = 20*num_blocks
+        while max_tries > 0:
+            results = [ blockhash in c.cb.block_request_map and
+                        c.cb.block_request_map[blockhash] for c in self.connections ]
+            if False not in results:
+                break
+            time.sleep(0.05)
+            max_tries -= 1
+
+        # --> error if not requested
+        if max_tries == 0:
+            # print [ c.cb.block_request_map for c in self.connections ]
+            raise AssertionError("Not all nodes requested block")
+        # --> Answer request (we did this inline!)
+
+        # Send getheaders message
+        [ c.cb.send_getheaders() for c in self.connections ]
+
+        # Send ping and wait for response -- synchronization hack
+        [ c.cb.send_ping(self.ping_counter) for c in self.connections ]
+        self.wait_for_pings(self.ping_counter)
+        self.ping_counter += 1
+
+    # Analogous to sync_block (see above)
+    def sync_transaction(self, txhash, num_events):
+        # Wait for nodes to request transaction (50ms sleep * 20 tries * num_events)
+        max_tries = 20*num_events
+        while max_tries > 0:
+            results = [ txhash in c.cb.tx_request_map and
+                        c.cb.tx_request_map[txhash] for c in self.connections ]
+            if False not in results:
+                break
+            time.sleep(0.05)
+            max_tries -= 1
+
+        # --> error if not requested
+        if max_tries == 0:
+            # print [ c.cb.tx_request_map for c in self.connections ]
+            raise AssertionError("Not all nodes requested transaction")
+        # --> Answer request (we did this inline!)
+
+        # Get the mempool
+        [ c.cb.send_mempool() for c in self.connections ]
+
+        # Send ping and wait for response -- synchronization hack
+        [ c.cb.send_ping(self.ping_counter) for c in self.connections ]
+        self.wait_for_pings(self.ping_counter)
+        self.ping_counter += 1
+
+        # Sort inv responses from each node
+        [ c.cb.lastInv.sort() for c in self.connections ]
+
+    # Verify that the tip of each connection all agree with each other, and
+    # with the expected outcome (if given)
+    def check_results(self, blockhash, outcome):
+        for c in self.connections:
+            if outcome is None:
+                if c.cb.bestblockhash != self.connections[0].cb.bestblockhash:
+                    return False
+            elif ((c.cb.bestblockhash == blockhash) != outcome):
+                # print c.cb.bestblockhash, blockhash, outcome
+                return False
+        return True
+
+    # Either check that the mempools all agree with each other, or that
+    # txhash's presence in the mempool matches the outcome specified.
+    # This is somewhat of a strange comparison, in that we're either comparing
+    # a particular tx to an outcome, or the entire mempools altogether;
+    # perhaps it would be useful to add the ability to check explicitly that
+    # a particular tx's existence in the mempool is the same across all nodes.
+    def check_mempool(self, txhash, outcome):
+        for c in self.connections:
+            if outcome is None:
+                # Make sure the mempools agree with each other
+                if c.cb.lastInv != self.connections[0].cb.lastInv:
+                    # print c.rpc.getrawmempool()
+                    return False
+            elif ((txhash in c.cb.lastInv) != outcome):
+                # print c.rpc.getrawmempool(), c.cb.lastInv
+                return False
+        return True
+
+    def run(self):
+        # Wait until verack is received
+        self.wait_for_verack()
+
+        test_number = 1
+        for test_instance in self.test_generator.get_tests():
+            # We use these variables to keep track of the last block
+            # and last transaction in the tests, which are used
+            # if we're not syncing on every block or every tx.
+            [ block, block_outcome ] = [ None, None ]
+            [ tx, tx_outcome ] = [ None, None ]
+            invqueue = []
+
+            for b_or_t, outcome in test_instance.blocks_and_transactions:
+                # Determine if we're dealing with a block or tx
+                if isinstance(b_or_t, CBlock):  # Block test runner
+                    block = b_or_t
+                    block_outcome = outcome
+                    # Add to shared block_store, set as current block
+                    self.block_store.add_block(block)
+                    for c in self.connections:
+                        c.cb.block_request_map[block.sha256] = False
+                    # Either send inv's to each node and sync, or add
+                    # to invqueue for later inv'ing.
+                    if (test_instance.sync_every_block):
+                        [ c.cb.send_inv(block) for c in self.connections ]
+                        self.sync_blocks(block.sha256, 1)
+                        if (not self.check_results(block.sha256, outcome)):
+                            raise AssertionError("Test failed at test %d" % test_number)
+                    else:
+                        invqueue.append(CInv(2, block.sha256))
+                else:  # Tx test runner
+                    assert(isinstance(b_or_t, CTransaction))
+                    tx = b_or_t
+                    tx_outcome = outcome
+                    # Add to shared tx store
+                    self.tx_store.add_transaction(tx)
+                    for c in self.connections:
+                        c.cb.tx_request_map[tx.sha256] = False
+                    # Again, either inv to all nodes or save for later
+                    if (test_instance.sync_every_tx):
+                        [ c.cb.send_inv(tx) for c in self.connections ]
+                        self.sync_transaction(tx.sha256, 1)
+                        if (not self.check_mempool(tx.sha256, outcome)):
+                            raise AssertionError("Test failed at test %d" % test_number)
+                    else:
+                        invqueue.append(CInv(1, tx.sha256))
+                # Ensure we're not overflowing the inv queue
+                if len(invqueue) == MAX_INV_SZ:
+                    [ c.sb.send_message(msg_inv(invqueue)) for c in self.connections ]
+                    invqueue = []
+
+            # Do final sync if we weren't syncing on every block or every tx.
+            if (not test_instance.sync_every_block and block is not None):
+                if len(invqueue) > 0:
+                    [ c.send_message(msg_inv(invqueue)) for c in self.connections ]
+                    invqueue = []
+                self.sync_blocks(block.sha256,
+                                 len(test_instance.blocks_and_transactions))
+                if (not self.check_results(block.sha256, block_outcome)):
+                    raise AssertionError("Block test failed at test %d" % test_number)
+            if (not test_instance.sync_every_tx and tx is not None):
+                if len(invqueue) > 0:
+                    [ c.send_message(msg_inv(invqueue)) for c in self.connections ]
+                    invqueue = []
+                self.sync_transaction(tx.sha256, len(test_instance.blocks_and_transactions))
+                if (not self.check_mempool(tx.sha256, tx_outcome)):
+                    raise AssertionError("Mempool test failed at test %d" % test_number)
+
+            print "Test %d: PASS" % test_number, [ c.rpc.getblockcount() for c in self.connections ]
+            test_number += 1
+
+        self.block_store.close()
+        self.tx_store.close()
+        [ c.disconnect_node() for c in self.connections ]
diff --git a/qa/rpc-tests/invalidblockrequest.py b/qa/rpc-tests/invalidblockrequest.py
new file mode 100755
index 0000000000..8b685ed9b2
--- /dev/null
+++ b/qa/rpc-tests/invalidblockrequest.py
@@ -0,0 +1,115 @@
+#!/usr/bin/env python2
+#
+# Distributed under the MIT/X11 software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+#
+
+from test_framework import ComparisonTestFramework
+from util import *
+from comptool import TestManager, TestInstance
+from mininode import *
+from blocktools import *
+import logging
+import copy
+import time
+
+
+'''
+In this test we connect to one node over p2p, and test block requests:
+1) Valid blocks should be requested and become chain tip.
+2) Invalid block with duplicated transaction should be re-requested.
+3) Invalid block with bad coinbase value should be rejected and not
+re-requested.
+'''
+
+# Use the ComparisonTestFramework with 1 node: only use --testbinary.
+class InvalidBlockRequestTest(ComparisonTestFramework):
+
+    ''' Can either run this test as 1 node with expected answers, or two and compare them. 
+        Change the "outcome" variable from each TestInstance object to only do the comparison. '''
+    def __init__(self):
+        self.num_nodes = 1
+
+    def run_test(self):
+        test = TestManager(self, self.options.tmpdir)
+        test.add_all_connections(self.nodes)
+        self.tip = None
+        self.block_time = None
+        NetworkThread().start() # Start up network handling in another thread
+        test.run()
+
+    def get_tests(self):
+        if self.tip is None:
+            self.tip = int ("0x" + self.nodes[0].getbestblockhash() + "L", 0)
+        self.block_time = int(time.time())+1
+
+        '''
+        Create a new block with an anyone-can-spend coinbase
+        '''
+        block = create_block(self.tip, create_coinbase(), self.block_time)
+        self.block_time += 1
+        block.solve()
+        # Save the coinbase for later
+        self.block1 = block
+        self.tip = block.sha256
+        yield TestInstance([[block, True]])
+
+        '''
+        Now we need that block to mature so we can spend the coinbase.
+        '''
+        test = TestInstance(sync_every_block=False)
+        for i in xrange(100):
+            block = create_block(self.tip, create_coinbase(), self.block_time)
+            block.solve()
+            self.tip = block.sha256
+            self.block_time += 1
+            test.blocks_and_transactions.append([block, True])
+        yield test
+
+        '''
+        Now we use merkle-root malleability to generate an invalid block with
+        same blockheader.
+        Manufacture a block with 3 transactions (coinbase, spend of prior
+        coinbase, spend of that spend).  Duplicate the 3rd transaction to 
+        leave merkle root and blockheader unchanged but invalidate the block.
+        '''
+        block2 = create_block(self.tip, create_coinbase(), self.block_time)
+        self.block_time += 1
+
+        # chr(81) is OP_TRUE
+        tx1 = create_transaction(self.block1.vtx[0], 0, chr(81), 50*100000000)
+        tx2 = create_transaction(tx1, 0, chr(81), 50*100000000)
+
+        block2.vtx.extend([tx1, tx2])
+        block2.hashMerkleRoot = block2.calc_merkle_root()
+        block2.rehash()
+        block2.solve()
+        orig_hash = block2.sha256
+        block2_orig = copy.deepcopy(block2)
+
+        # Mutate block 2
+        block2.vtx.append(tx2)
+        assert_equal(block2.hashMerkleRoot, block2.calc_merkle_root())
+        assert_equal(orig_hash, block2.rehash())
+        assert(block2_orig.vtx != block2.vtx)
+
+        self.tip = block2.sha256
+        yield TestInstance([[block2, False], [block2_orig, True]])
+
+        '''
+        Make sure that a totally screwed up block is not valid.
+        '''
+        block3 = create_block(self.tip, create_coinbase(), self.block_time)
+        self.block_time += 1
+        block3.vtx[0].vout[0].nValue = 100*100000000 # Too high!
+        block3.vtx[0].sha256=None
+        block3.vtx[0].calc_sha256()
+        block3.hashMerkleRoot = block3.calc_merkle_root()
+        block3.rehash()
+        block3.solve()
+
+        yield TestInstance([[block3, False]])
+
+
+if __name__ == '__main__':
+    InvalidBlockRequestTest().main()
diff --git a/qa/rpc-tests/test_framework.py b/qa/rpc-tests/test_framework.py
index 4c8a11b821..f61b13dfe6 100755
--- a/qa/rpc-tests/test_framework.py
+++ b/qa/rpc-tests/test_framework.py
@@ -140,3 +140,32 @@ class BitcoinTestFramework(object):
         else:
             print("Failed")
             sys.exit(1)
+
+
+# Test framework for doing p2p comparison testing, which sets up some bitcoind
+# binaries:
+# 1 binary: test binary
+# 2 binaries: 1 test binary, 1 ref binary
+# n>2 binaries: 1 test binary, n-1 ref binaries
+
+class ComparisonTestFramework(BitcoinTestFramework):
+
+    # Can override the num_nodes variable to indicate how many nodes to run.
+    def __init__(self):
+        self.num_nodes = 2
+
+    def add_options(self, parser):
+        parser.add_option("--testbinary", dest="testbinary", default="bitcoind",
+                          help="bitcoind binary to test")
+        parser.add_option("--refbinary", dest="refbinary", default="bitcoind",
+                          help="bitcoind binary to use for reference nodes (if any)")
+
+    def setup_chain(self):
+        print "Initializing test directory "+self.options.tmpdir
+        initialize_chain_clean(self.options.tmpdir, self.num_nodes)
+
+    def setup_network(self):
+        self.nodes = start_nodes(self.num_nodes, self.options.tmpdir,
+                                    extra_args=[['-debug', '-whitelist=127.0.0.1']] * self.num_nodes,
+                                    binary=[self.options.testbinary] +
+                                           [self.options.refbinary]*(self.num_nodes-1))