Merge #11648: [tests] Add messages.py

1135c79 [tests] Tidy up mininode.py module (John Newbery)
f9cd9b1 [tests] Move test_framework Bitcoin primitives into separate module (John Newbery)

Pull request description:

  Second part of #11518.

  Moves the primitive Bitcoin datastructures and message classes into their own module, and tidies up the mininode.py module.

  - First commit is almost entirely move-only
  - Second commit is mostly move-only, but also does a little tidying.

Tree-SHA512: 5d74802677f1ab788e43188653106a96fffd9ab1fe3aa6a4eb94e5807de5dd5c8ee212296f45e8d16c7e3d95cfc4891677e812b7944bd3ab604e04b3b88aa06e

2 files changed, 1412 insertions, 1383 deletions

diff --git a/test/functional/test_framework/messages.py b/test/functional/test_framework/messages.py
new file mode 100644
index 0000000000..40d02f3ee0
--- /dev/null
+++ b/test/functional/test_framework/messages.py
@@ -0,0 +1,1319 @@
+#!/usr/bin/env python3
+# Copyright (c) 2010 ArtForz -- public domain half-a-node
+# Copyright (c) 2012 Jeff Garzik
+# Copyright (c) 2010-2017 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+"""Bitcoin test framework primitive and message strcutures
+
+CBlock, CTransaction, CBlockHeader, CTxIn, CTxOut, etc....:
+    data structures that should map to corresponding structures in
+    bitcoin/primitives
+
+msg_block, msg_tx, msg_headers, etc.:
+    data structures that represent network messages
+
+ser_*, deser_*: functions that handle serialization/deserialization."""
+from codecs import encode
+import copy
+import hashlib
+from io import BytesIO
+import random
+import socket
+import struct
+import time
+
+from test_framework.siphash import siphash256
+from test_framework.util import hex_str_to_bytes, bytes_to_hex_str, wait_until
+
+MIN_VERSION_SUPPORTED = 60001
+MY_VERSION = 70014  # past bip-31 for ping/pong
+MY_SUBVERSION = b"/python-mininode-tester:0.0.3/"
+MY_RELAY = 1 # from version 70001 onwards, fRelay should be appended to version messages (BIP37)
+
+MAX_INV_SZ = 50000
+MAX_BLOCK_BASE_SIZE = 1000000
+
+COIN = 100000000 # 1 btc in satoshis
+
+NODE_NETWORK = (1 << 0)
+# NODE_GETUTXO = (1 << 1)
+# NODE_BLOOM = (1 << 2)
+NODE_WITNESS = (1 << 3)
+NODE_UNSUPPORTED_SERVICE_BIT_5 = (1 << 5)
+NODE_UNSUPPORTED_SERVICE_BIT_7 = (1 << 7)
+
+# Serialization/deserialization tools
+def sha256(s):
+    return hashlib.new('sha256', s).digest()
+
+def ripemd160(s):
+    return hashlib.new('ripemd160', s).digest()
+
+def hash256(s):
+    return sha256(sha256(s))
+
+def ser_compact_size(l):
+    r = b""
+    if l < 253:
+        r = struct.pack("B", l)
+    elif l < 0x10000:
+        r = struct.pack("<BH", 253, l)
+    elif l < 0x100000000:
+        r = struct.pack("<BI", 254, l)
+    else:
+        r = struct.pack("<BQ", 255, l)
+    return r
+
+def deser_compact_size(f):
+    nit = struct.unpack("<B", f.read(1))[0]
+    if nit == 253:
+        nit = struct.unpack("<H", f.read(2))[0]
+    elif nit == 254:
+        nit = struct.unpack("<I", f.read(4))[0]
+    elif nit == 255:
+        nit = struct.unpack("<Q", f.read(8))[0]
+    return nit
+
+def deser_string(f):
+    nit = deser_compact_size(f)
+    return f.read(nit)
+
+def ser_string(s):
+    return ser_compact_size(len(s)) + s
+
+def deser_uint256(f):
+    r = 0
+    for i in range(8):
+        t = struct.unpack("<I", f.read(4))[0]
+        r += t << (i * 32)
+    return r
+
+
+def ser_uint256(u):
+    rs = b""
+    for i in range(8):
+        rs += struct.pack("<I", u & 0xFFFFFFFF)
+        u >>= 32
+    return rs
+
+
+def uint256_from_str(s):
+    r = 0
+    t = struct.unpack("<IIIIIIII", s[:32])
+    for i in range(8):
+        r += t[i] << (i * 32)
+    return r
+
+
+def uint256_from_compact(c):
+    nbytes = (c >> 24) & 0xFF
+    v = (c & 0xFFFFFF) << (8 * (nbytes - 3))
+    return v
+
+
+def deser_vector(f, c):
+    nit = deser_compact_size(f)
+    r = []
+    for i in range(nit):
+        t = c()
+        t.deserialize(f)
+        r.append(t)
+    return r
+
+
+# ser_function_name: Allow for an alternate serialization function on the
+# entries in the vector (we use this for serializing the vector of transactions
+# for a witness block).
+def ser_vector(l, ser_function_name=None):
+    r = ser_compact_size(len(l))
+    for i in l:
+        if ser_function_name:
+            r += getattr(i, ser_function_name)()
+        else:
+            r += i.serialize()
+    return r
+
+
+def deser_uint256_vector(f):
+    nit = deser_compact_size(f)
+    r = []
+    for i in range(nit):
+        t = deser_uint256(f)
+        r.append(t)
+    return r
+
+
+def ser_uint256_vector(l):
+    r = ser_compact_size(len(l))
+    for i in l:
+        r += ser_uint256(i)
+    return r
+
+
+def deser_string_vector(f):
+    nit = deser_compact_size(f)
+    r = []
+    for i in range(nit):
+        t = deser_string(f)
+        r.append(t)
+    return r
+
+
+def ser_string_vector(l):
+    r = ser_compact_size(len(l))
+    for sv in l:
+        r += ser_string(sv)
+    return r
+
+
+def deser_int_vector(f):
+    nit = deser_compact_size(f)
+    r = []
+    for i in range(nit):
+        t = struct.unpack("<i", f.read(4))[0]
+        r.append(t)
+    return r
+
+
+def ser_int_vector(l):
+    r = ser_compact_size(len(l))
+    for i in l:
+        r += struct.pack("<i", i)
+    return r
+
+# Deserialize from a hex string representation (eg from RPC)
+def FromHex(obj, hex_string):
+    obj.deserialize(BytesIO(hex_str_to_bytes(hex_string)))
+    return obj
+
+# Convert a binary-serializable object to hex (eg for submission via RPC)
+def ToHex(obj):
+    return bytes_to_hex_str(obj.serialize())
+
+# Objects that map to bitcoind objects, which can be serialized/deserialized
+
+class CAddress():
+    def __init__(self):
+        self.nServices = 1
+        self.pchReserved = b"\x00" * 10 + b"\xff" * 2
+        self.ip = "0.0.0.0"
+        self.port = 0
+
+    def deserialize(self, f):
+        self.nServices = struct.unpack("<Q", f.read(8))[0]
+        self.pchReserved = f.read(12)
+        self.ip = socket.inet_ntoa(f.read(4))
+        self.port = struct.unpack(">H", f.read(2))[0]
+
+    def serialize(self):
+        r = b""
+        r += struct.pack("<Q", self.nServices)
+        r += self.pchReserved
+        r += socket.inet_aton(self.ip)
+        r += struct.pack(">H", self.port)
+        return r
+
+    def __repr__(self):
+        return "CAddress(nServices=%i ip=%s port=%i)" % (self.nServices,
+                                                         self.ip, self.port)
+
+MSG_WITNESS_FLAG = 1<<30
+
+class CInv():
+    typemap = {
+        0: "Error",
+        1: "TX",
+        2: "Block",
+        1|MSG_WITNESS_FLAG: "WitnessTx",
+        2|MSG_WITNESS_FLAG : "WitnessBlock",
+        4: "CompactBlock"
+    }
+
+    def __init__(self, t=0, h=0):
+        self.type = t
+        self.hash = h
+
+    def deserialize(self, f):
+        self.type = struct.unpack("<i", f.read(4))[0]
+        self.hash = deser_uint256(f)
+
+    def serialize(self):
+        r = b""
+        r += struct.pack("<i", self.type)
+        r += ser_uint256(self.hash)
+        return r
+
+    def __repr__(self):
+        return "CInv(type=%s hash=%064x)" \
+            % (self.typemap[self.type], self.hash)
+
+
+class CBlockLocator():
+    def __init__(self):
+        self.nVersion = MY_VERSION
+        self.vHave = []
+
+    def deserialize(self, f):
+        self.nVersion = struct.unpack("<i", f.read(4))[0]
+        self.vHave = deser_uint256_vector(f)
+
+    def serialize(self):
+        r = b""
+        r += struct.pack("<i", self.nVersion)
+        r += ser_uint256_vector(self.vHave)
+        return r
+
+    def __repr__(self):
+        return "CBlockLocator(nVersion=%i vHave=%s)" \
+            % (self.nVersion, repr(self.vHave))
+
+
+class COutPoint():
+    def __init__(self, hash=0, n=0):
+        self.hash = hash
+        self.n = n
+
+    def deserialize(self, f):
+        self.hash = deser_uint256(f)
+        self.n = struct.unpack("<I", f.read(4))[0]
+
+    def serialize(self):
+        r = b""
+        r += ser_uint256(self.hash)
+        r += struct.pack("<I", self.n)
+        return r
+
+    def __repr__(self):
+        return "COutPoint(hash=%064x n=%i)" % (self.hash, self.n)
+
+
+class CTxIn():
+    def __init__(self, outpoint=None, scriptSig=b"", nSequence=0):
+        if outpoint is None:
+            self.prevout = COutPoint()
+        else:
+            self.prevout = outpoint
+        self.scriptSig = scriptSig
+        self.nSequence = nSequence
+
+    def deserialize(self, f):
+        self.prevout = COutPoint()
+        self.prevout.deserialize(f)
+        self.scriptSig = deser_string(f)
+        self.nSequence = struct.unpack("<I", f.read(4))[0]
+
+    def serialize(self):
+        r = b""
+        r += self.prevout.serialize()
+        r += ser_string(self.scriptSig)
+        r += struct.pack("<I", self.nSequence)
+        return r
+
+    def __repr__(self):
+        return "CTxIn(prevout=%s scriptSig=%s nSequence=%i)" \
+            % (repr(self.prevout), bytes_to_hex_str(self.scriptSig),
+               self.nSequence)
+
+
+class CTxOut():
+    def __init__(self, nValue=0, scriptPubKey=b""):
+        self.nValue = nValue
+        self.scriptPubKey = scriptPubKey
+
+    def deserialize(self, f):
+        self.nValue = struct.unpack("<q", f.read(8))[0]
+        self.scriptPubKey = deser_string(f)
+
+    def serialize(self):
+        r = b""
+        r += struct.pack("<q", self.nValue)
+        r += ser_string(self.scriptPubKey)
+        return r
+
+    def __repr__(self):
+        return "CTxOut(nValue=%i.%08i scriptPubKey=%s)" \
+            % (self.nValue // COIN, self.nValue % COIN,
+               bytes_to_hex_str(self.scriptPubKey))
+
+
+class CScriptWitness():
+    def __init__(self):
+        # stack is a vector of strings
+        self.stack = []
+
+    def __repr__(self):
+        return "CScriptWitness(%s)" % \
+               (",".join([bytes_to_hex_str(x) for x in self.stack]))
+
+    def is_null(self):
+        if self.stack:
+            return False
+        return True
+
+
+class CTxInWitness():
+    def __init__(self):
+        self.scriptWitness = CScriptWitness()
+
+    def deserialize(self, f):
+        self.scriptWitness.stack = deser_string_vector(f)
+
+    def serialize(self):
+        return ser_string_vector(self.scriptWitness.stack)
+
+    def __repr__(self):
+        return repr(self.scriptWitness)
+
+    def is_null(self):
+        return self.scriptWitness.is_null()
+
+
+class CTxWitness():
+    def __init__(self):
+        self.vtxinwit = []
+
+    def deserialize(self, f):
+        for i in range(len(self.vtxinwit)):
+            self.vtxinwit[i].deserialize(f)
+
+    def serialize(self):
+        r = b""
+        # This is different than the usual vector serialization --
+        # we omit the length of the vector, which is required to be
+        # the same length as the transaction's vin vector.
+        for x in self.vtxinwit:
+            r += x.serialize()
+        return r
+
+    def __repr__(self):
+        return "CTxWitness(%s)" % \
+               (';'.join([repr(x) for x in self.vtxinwit]))
+
+    def is_null(self):
+        for x in self.vtxinwit:
+            if not x.is_null():
+                return False
+        return True
+
+
+class CTransaction():
+    def __init__(self, tx=None):
+        if tx is None:
+            self.nVersion = 1
+            self.vin = []
+            self.vout = []
+            self.wit = CTxWitness()
+            self.nLockTime = 0
+            self.sha256 = None
+            self.hash = None
+        else:
+            self.nVersion = tx.nVersion
+            self.vin = copy.deepcopy(tx.vin)
+            self.vout = copy.deepcopy(tx.vout)
+            self.nLockTime = tx.nLockTime
+            self.sha256 = tx.sha256
+            self.hash = tx.hash
+            self.wit = copy.deepcopy(tx.wit)
+
+    def deserialize(self, f):
+        self.nVersion = struct.unpack("<i", f.read(4))[0]
+        self.vin = deser_vector(f, CTxIn)
+        flags = 0
+        if len(self.vin) == 0:
+            flags = struct.unpack("<B", f.read(1))[0]
+            # Not sure why flags can't be zero, but this
+            # matches the implementation in bitcoind
+            if (flags != 0):
+                self.vin = deser_vector(f, CTxIn)
+                self.vout = deser_vector(f, CTxOut)
+        else:
+            self.vout = deser_vector(f, CTxOut)
+        if flags != 0:
+            self.wit.vtxinwit = [CTxInWitness() for i in range(len(self.vin))]
+            self.wit.deserialize(f)
+        self.nLockTime = struct.unpack("<I", f.read(4))[0]
+        self.sha256 = None
+        self.hash = None
+
+    def serialize_without_witness(self):
+        r = b""
+        r += struct.pack("<i", self.nVersion)
+        r += ser_vector(self.vin)
+        r += ser_vector(self.vout)
+        r += struct.pack("<I", self.nLockTime)
+        return r
+
+    # Only serialize with witness when explicitly called for
+    def serialize_with_witness(self):
+        flags = 0
+        if not self.wit.is_null():
+            flags |= 1
+        r = b""
+        r += struct.pack("<i", self.nVersion)
+        if flags:
+            dummy = []
+            r += ser_vector(dummy)
+            r += struct.pack("<B", flags)
+        r += ser_vector(self.vin)
+        r += ser_vector(self.vout)
+        if flags & 1:
+            if (len(self.wit.vtxinwit) != len(self.vin)):
+                # vtxinwit must have the same length as vin
+                self.wit.vtxinwit = self.wit.vtxinwit[:len(self.vin)]
+                for i in range(len(self.wit.vtxinwit), len(self.vin)):
+                    self.wit.vtxinwit.append(CTxInWitness())
+            r += self.wit.serialize()
+        r += struct.pack("<I", self.nLockTime)
+        return r
+
+    # Regular serialization is without witness -- must explicitly
+    # call serialize_with_witness to include witness data.
+    def serialize(self):
+        return self.serialize_without_witness()
+
+    # Recalculate the txid (transaction hash without witness)
+    def rehash(self):
+        self.sha256 = None
+        self.calc_sha256()
+
+    # We will only cache the serialization without witness in
+    # self.sha256 and self.hash -- those are expected to be the txid.
+    def calc_sha256(self, with_witness=False):
+        if with_witness:
+            # Don't cache the result, just return it
+            return uint256_from_str(hash256(self.serialize_with_witness()))
+
+        if self.sha256 is None:
+            self.sha256 = uint256_from_str(hash256(self.serialize_without_witness()))
+        self.hash = encode(hash256(self.serialize())[::-1], 'hex_codec').decode('ascii')
+
+    def is_valid(self):
+        self.calc_sha256()
+        for tout in self.vout:
+            if tout.nValue < 0 or tout.nValue > 21000000 * COIN:
+                return False
+        return True
+
+    def __repr__(self):
+        return "CTransaction(nVersion=%i vin=%s vout=%s wit=%s nLockTime=%i)" \
+            % (self.nVersion, repr(self.vin), repr(self.vout), repr(self.wit), self.nLockTime)
+
+
+class CBlockHeader():
+    def __init__(self, header=None):
+        if header is None:
+            self.set_null()
+        else:
+            self.nVersion = header.nVersion
+            self.hashPrevBlock = header.hashPrevBlock
+            self.hashMerkleRoot = header.hashMerkleRoot
+            self.nTime = header.nTime
+            self.nBits = header.nBits
+            self.nNonce = header.nNonce
+            self.sha256 = header.sha256
+            self.hash = header.hash
+            self.calc_sha256()
+
+    def set_null(self):
+        self.nVersion = 1
+        self.hashPrevBlock = 0
+        self.hashMerkleRoot = 0
+        self.nTime = 0
+        self.nBits = 0
+        self.nNonce = 0
+        self.sha256 = None
+        self.hash = None
+
+    def deserialize(self, f):
+        self.nVersion = struct.unpack("<i", f.read(4))[0]
+        self.hashPrevBlock = deser_uint256(f)
+        self.hashMerkleRoot = deser_uint256(f)
+        self.nTime = struct.unpack("<I", f.read(4))[0]
+        self.nBits = struct.unpack("<I", f.read(4))[0]
+        self.nNonce = struct.unpack("<I", f.read(4))[0]
+        self.sha256 = None
+        self.hash = None
+
+    def serialize(self):
+        r = b""
+        r += struct.pack("<i", self.nVersion)
+        r += ser_uint256(self.hashPrevBlock)
+        r += ser_uint256(self.hashMerkleRoot)
+        r += struct.pack("<I", self.nTime)
+        r += struct.pack("<I", self.nBits)
+        r += struct.pack("<I", self.nNonce)
+        return r
+
+    def calc_sha256(self):
+        if self.sha256 is None:
+            r = b""
+            r += struct.pack("<i", self.nVersion)
+            r += ser_uint256(self.hashPrevBlock)
+            r += ser_uint256(self.hashMerkleRoot)
+            r += struct.pack("<I", self.nTime)
+            r += struct.pack("<I", self.nBits)
+            r += struct.pack("<I", self.nNonce)
+            self.sha256 = uint256_from_str(hash256(r))
+            self.hash = encode(hash256(r)[::-1], 'hex_codec').decode('ascii')
+
+    def rehash(self):
+        self.sha256 = None
+        self.calc_sha256()
+        return self.sha256
+
+    def __repr__(self):
+        return "CBlockHeader(nVersion=%i hashPrevBlock=%064x hashMerkleRoot=%064x nTime=%s nBits=%08x nNonce=%08x)" \
+            % (self.nVersion, self.hashPrevBlock, self.hashMerkleRoot,
+               time.ctime(self.nTime), self.nBits, self.nNonce)
+
+
+class CBlock(CBlockHeader):
+    def __init__(self, header=None):
+        super(CBlock, self).__init__(header)
+        self.vtx = []
+
+    def deserialize(self, f):
+        super(CBlock, self).deserialize(f)
+        self.vtx = deser_vector(f, CTransaction)
+
+    def serialize(self, with_witness=False):
+        r = b""
+        r += super(CBlock, self).serialize()
+        if with_witness:
+            r += ser_vector(self.vtx, "serialize_with_witness")
+        else:
+            r += ser_vector(self.vtx)
+        return r
+
+    # Calculate the merkle root given a vector of transaction hashes
+    @classmethod
+    def get_merkle_root(cls, hashes):
+        while len(hashes) > 1:
+            newhashes = []
+            for i in range(0, len(hashes), 2):
+                i2 = min(i+1, len(hashes)-1)
+                newhashes.append(hash256(hashes[i] + hashes[i2]))
+            hashes = newhashes
+        return uint256_from_str(hashes[0])
+
+    def calc_merkle_root(self):
+        hashes = []
+        for tx in self.vtx:
+            tx.calc_sha256()
+            hashes.append(ser_uint256(tx.sha256))
+        return self.get_merkle_root(hashes)
+
+    def calc_witness_merkle_root(self):
+        # For witness root purposes, the hash of the
+        # coinbase, with witness, is defined to be 0...0
+        hashes = [ser_uint256(0)]
+
+        for tx in self.vtx[1:]:
+            # Calculate the hashes with witness data
+            hashes.append(ser_uint256(tx.calc_sha256(True)))
+
+        return self.get_merkle_root(hashes)
+
+    def is_valid(self):
+        self.calc_sha256()
+        target = uint256_from_compact(self.nBits)
+        if self.sha256 > target:
+            return False
+        for tx in self.vtx:
+            if not tx.is_valid():
+                return False
+        if self.calc_merkle_root() != self.hashMerkleRoot:
+            return False
+        return True
+
+    def solve(self):
+        self.rehash()
+        target = uint256_from_compact(self.nBits)
+        while self.sha256 > target:
+            self.nNonce += 1
+            self.rehash()
+
+    def __repr__(self):
+        return "CBlock(nVersion=%i hashPrevBlock=%064x hashMerkleRoot=%064x nTime=%s nBits=%08x nNonce=%08x vtx=%s)" \
+            % (self.nVersion, self.hashPrevBlock, self.hashMerkleRoot,
+               time.ctime(self.nTime), self.nBits, self.nNonce, repr(self.vtx))
+
+
+class PrefilledTransaction():
+    def __init__(self, index=0, tx = None):
+        self.index = index
+        self.tx = tx
+
+    def deserialize(self, f):
+        self.index = deser_compact_size(f)
+        self.tx = CTransaction()
+        self.tx.deserialize(f)
+
+    def serialize(self, with_witness=False):
+        r = b""
+        r += ser_compact_size(self.index)
+        if with_witness:
+            r += self.tx.serialize_with_witness()
+        else:
+            r += self.tx.serialize_without_witness()
+        return r
+
+    def serialize_with_witness(self):
+        return self.serialize(with_witness=True)
+
+    def __repr__(self):
+        return "PrefilledTransaction(index=%d, tx=%s)" % (self.index, repr(self.tx))
+
+# This is what we send on the wire, in a cmpctblock message.
+class P2PHeaderAndShortIDs():
+    def __init__(self):
+        self.header = CBlockHeader()
+        self.nonce = 0
+        self.shortids_length = 0
+        self.shortids = []
+        self.prefilled_txn_length = 0
+        self.prefilled_txn = []
+
+    def deserialize(self, f):
+        self.header.deserialize(f)
+        self.nonce = struct.unpack("<Q", f.read(8))[0]
+        self.shortids_length = deser_compact_size(f)
+        for i in range(self.shortids_length):
+            # shortids are defined to be 6 bytes in the spec, so append
+            # two zero bytes and read it in as an 8-byte number
+            self.shortids.append(struct.unpack("<Q", f.read(6) + b'\x00\x00')[0])
+        self.prefilled_txn = deser_vector(f, PrefilledTransaction)
+        self.prefilled_txn_length = len(self.prefilled_txn)
+
+    # When using version 2 compact blocks, we must serialize with_witness.
+    def serialize(self, with_witness=False):
+        r = b""
+        r += self.header.serialize()
+        r += struct.pack("<Q", self.nonce)
+        r += ser_compact_size(self.shortids_length)
+        for x in self.shortids:
+            # We only want the first 6 bytes
+            r += struct.pack("<Q", x)[0:6]
+        if with_witness:
+            r += ser_vector(self.prefilled_txn, "serialize_with_witness")
+        else:
+            r += ser_vector(self.prefilled_txn)
+        return r
+
+    def __repr__(self):
+        return "P2PHeaderAndShortIDs(header=%s, nonce=%d, shortids_length=%d, shortids=%s, prefilled_txn_length=%d, prefilledtxn=%s" % (repr(self.header), self.nonce, self.shortids_length, repr(self.shortids), self.prefilled_txn_length, repr(self.prefilled_txn))
+
+# P2P version of the above that will use witness serialization (for compact
+# block version 2)
+class P2PHeaderAndShortWitnessIDs(P2PHeaderAndShortIDs):
+    def serialize(self):
+        return super(P2PHeaderAndShortWitnessIDs, self).serialize(with_witness=True)
+
+# Calculate the BIP 152-compact blocks shortid for a given transaction hash
+def calculate_shortid(k0, k1, tx_hash):
+    expected_shortid = siphash256(k0, k1, tx_hash)
+    expected_shortid &= 0x0000ffffffffffff
+    return expected_shortid
+
+# This version gets rid of the array lengths, and reinterprets the differential
+# encoding into indices that can be used for lookup.
+class HeaderAndShortIDs():
+    def __init__(self, p2pheaders_and_shortids = None):
+        self.header = CBlockHeader()
+        self.nonce = 0
+        self.shortids = []
+        self.prefilled_txn = []
+        self.use_witness = False
+
+        if p2pheaders_and_shortids != None:
+            self.header = p2pheaders_and_shortids.header
+            self.nonce = p2pheaders_and_shortids.nonce
+            self.shortids = p2pheaders_and_shortids.shortids
+            last_index = -1
+            for x in p2pheaders_and_shortids.prefilled_txn:
+                self.prefilled_txn.append(PrefilledTransaction(x.index + last_index + 1, x.tx))
+                last_index = self.prefilled_txn[-1].index
+
+    def to_p2p(self):
+        if self.use_witness:
+            ret = P2PHeaderAndShortWitnessIDs()
+        else:
+            ret = P2PHeaderAndShortIDs()
+        ret.header = self.header
+        ret.nonce = self.nonce
+        ret.shortids_length = len(self.shortids)
+        ret.shortids = self.shortids
+        ret.prefilled_txn_length = len(self.prefilled_txn)
+        ret.prefilled_txn = []
+        last_index = -1
+        for x in self.prefilled_txn:
+            ret.prefilled_txn.append(PrefilledTransaction(x.index - last_index - 1, x.tx))
+            last_index = x.index
+        return ret
+
+    def get_siphash_keys(self):
+        header_nonce = self.header.serialize()
+        header_nonce += struct.pack("<Q", self.nonce)
+        hash_header_nonce_as_str = sha256(header_nonce)
+        key0 = struct.unpack("<Q", hash_header_nonce_as_str[0:8])[0]
+        key1 = struct.unpack("<Q", hash_header_nonce_as_str[8:16])[0]
+        return [ key0, key1 ]
+
+    # Version 2 compact blocks use wtxid in shortids (rather than txid)
+    def initialize_from_block(self, block, nonce=0, prefill_list = [0], use_witness = False):
+        self.header = CBlockHeader(block)
+        self.nonce = nonce
+        self.prefilled_txn = [ PrefilledTransaction(i, block.vtx[i]) for i in prefill_list ]
+        self.shortids = []
+        self.use_witness = use_witness
+        [k0, k1] = self.get_siphash_keys()
+        for i in range(len(block.vtx)):
+            if i not in prefill_list:
+                tx_hash = block.vtx[i].sha256
+                if use_witness:
+                    tx_hash = block.vtx[i].calc_sha256(with_witness=True)
+                self.shortids.append(calculate_shortid(k0, k1, tx_hash))
+
+    def __repr__(self):
+        return "HeaderAndShortIDs(header=%s, nonce=%d, shortids=%s, prefilledtxn=%s" % (repr(self.header), self.nonce, repr(self.shortids), repr(self.prefilled_txn))
+
+
+class BlockTransactionsRequest():
+
+    def __init__(self, blockhash=0, indexes = None):
+        self.blockhash = blockhash
+        self.indexes = indexes if indexes != None else []
+
+    def deserialize(self, f):
+        self.blockhash = deser_uint256(f)
+        indexes_length = deser_compact_size(f)
+        for i in range(indexes_length):
+            self.indexes.append(deser_compact_size(f))
+
+    def serialize(self):
+        r = b""
+        r += ser_uint256(self.blockhash)
+        r += ser_compact_size(len(self.indexes))
+        for x in self.indexes:
+            r += ser_compact_size(x)
+        return r
+
+    # helper to set the differentially encoded indexes from absolute ones
+    def from_absolute(self, absolute_indexes):
+        self.indexes = []
+        last_index = -1
+        for x in absolute_indexes:
+            self.indexes.append(x-last_index-1)
+            last_index = x
+
+    def to_absolute(self):
+        absolute_indexes = []
+        last_index = -1
+        for x in self.indexes:
+            absolute_indexes.append(x+last_index+1)
+            last_index = absolute_indexes[-1]
+        return absolute_indexes
+
+    def __repr__(self):
+        return "BlockTransactionsRequest(hash=%064x indexes=%s)" % (self.blockhash, repr(self.indexes))
+
+
+class BlockTransactions():
+
+    def __init__(self, blockhash=0, transactions = None):
+        self.blockhash = blockhash
+        self.transactions = transactions if transactions != None else []
+
+    def deserialize(self, f):
+        self.blockhash = deser_uint256(f)
+        self.transactions = deser_vector(f, CTransaction)
+
+    def serialize(self, with_witness=False):
+        r = b""
+        r += ser_uint256(self.blockhash)
+        if with_witness:
+            r += ser_vector(self.transactions, "serialize_with_witness")
+        else:
+            r += ser_vector(self.transactions)
+        return r
+
+    def __repr__(self):
+        return "BlockTransactions(hash=%064x transactions=%s)" % (self.blockhash, repr(self.transactions))
+
+
+# Objects that correspond to messages on the wire
+class msg_version():
+    command = b"version"
+
+    def __init__(self):
+        self.nVersion = MY_VERSION
+        self.nServices = NODE_NETWORK | NODE_WITNESS
+        self.nTime = int(time.time())
+        self.addrTo = CAddress()
+        self.addrFrom = CAddress()
+        self.nNonce = random.getrandbits(64)
+        self.strSubVer = MY_SUBVERSION
+        self.nStartingHeight = -1
+        self.nRelay = MY_RELAY
+
+    def deserialize(self, f):
+        self.nVersion = struct.unpack("<i", f.read(4))[0]
+        if self.nVersion == 10300:
+            self.nVersion = 300
+        self.nServices = struct.unpack("<Q", f.read(8))[0]
+        self.nTime = struct.unpack("<q", f.read(8))[0]
+        self.addrTo = CAddress()
+        self.addrTo.deserialize(f)
+
+        if self.nVersion >= 106:
+            self.addrFrom = CAddress()
+            self.addrFrom.deserialize(f)
+            self.nNonce = struct.unpack("<Q", f.read(8))[0]
+            self.strSubVer = deser_string(f)
+        else:
+            self.addrFrom = None
+            self.nNonce = None
+            self.strSubVer = None
+            self.nStartingHeight = None
+
+        if self.nVersion >= 209:
+            self.nStartingHeight = struct.unpack("<i", f.read(4))[0]
+        else:
+            self.nStartingHeight = None
+
+        if self.nVersion >= 70001:
+            # Relay field is optional for version 70001 onwards
+            try:
+                self.nRelay = struct.unpack("<b", f.read(1))[0]
+            except:
+                self.nRelay = 0
+        else:
+            self.nRelay = 0
+
+    def serialize(self):
+        r = b""
+        r += struct.pack("<i", self.nVersion)
+        r += struct.pack("<Q", self.nServices)
+        r += struct.pack("<q", self.nTime)
+        r += self.addrTo.serialize()
+        r += self.addrFrom.serialize()
+        r += struct.pack("<Q", self.nNonce)
+        r += ser_string(self.strSubVer)
+        r += struct.pack("<i", self.nStartingHeight)
+        r += struct.pack("<b", self.nRelay)
+        return r
+
+    def __repr__(self):
+        return 'msg_version(nVersion=%i nServices=%i nTime=%s addrTo=%s addrFrom=%s nNonce=0x%016X strSubVer=%s nStartingHeight=%i nRelay=%i)' \
+            % (self.nVersion, self.nServices, time.ctime(self.nTime),
+               repr(self.addrTo), repr(self.addrFrom), self.nNonce,
+               self.strSubVer, self.nStartingHeight, self.nRelay)
+
+
+class msg_verack():
+    command = b"verack"
+
+    def __init__(self):
+        pass
+
+    def deserialize(self, f):
+        pass
+
+    def serialize(self):
+        return b""
+
+    def __repr__(self):
+        return "msg_verack()"
+
+
+class msg_addr():
+    command = b"addr"
+
+    def __init__(self):
+        self.addrs = []
+
+    def deserialize(self, f):
+        self.addrs = deser_vector(f, CAddress)
+
+    def serialize(self):
+        return ser_vector(self.addrs)
+
+    def __repr__(self):
+        return "msg_addr(addrs=%s)" % (repr(self.addrs))
+
+
+class msg_inv():
+    command = b"inv"
+
+    def __init__(self, inv=None):
+        if inv is None:
+            self.inv = []
+        else:
+            self.inv = inv
+
+    def deserialize(self, f):
+        self.inv = deser_vector(f, CInv)
+
+    def serialize(self):
+        return ser_vector(self.inv)
+
+    def __repr__(self):
+        return "msg_inv(inv=%s)" % (repr(self.inv))
+
+
+class msg_getdata():
+    command = b"getdata"
+
+    def __init__(self, inv=None):
+        self.inv = inv if inv != None else []
+
+    def deserialize(self, f):
+        self.inv = deser_vector(f, CInv)
+
+    def serialize(self):
+        return ser_vector(self.inv)
+
+    def __repr__(self):
+        return "msg_getdata(inv=%s)" % (repr(self.inv))
+
+
+class msg_getblocks():
+    command = b"getblocks"
+
+    def __init__(self):
+        self.locator = CBlockLocator()
+        self.hashstop = 0
+
+    def deserialize(self, f):
+        self.locator = CBlockLocator()
+        self.locator.deserialize(f)
+        self.hashstop = deser_uint256(f)
+
+    def serialize(self):
+        r = b""
+        r += self.locator.serialize()
+        r += ser_uint256(self.hashstop)
+        return r
+
+    def __repr__(self):
+        return "msg_getblocks(locator=%s hashstop=%064x)" \
+            % (repr(self.locator), self.hashstop)
+
+
+class msg_tx():
+    command = b"tx"
+
+    def __init__(self, tx=CTransaction()):
+        self.tx = tx
+
+    def deserialize(self, f):
+        self.tx.deserialize(f)
+
+    def serialize(self):
+        return self.tx.serialize_without_witness()
+
+    def __repr__(self):
+        return "msg_tx(tx=%s)" % (repr(self.tx))
+
+class msg_witness_tx(msg_tx):
+
+    def serialize(self):
+        return self.tx.serialize_with_witness()
+
+
+class msg_block():
+    command = b"block"
+
+    def __init__(self, block=None):
+        if block is None:
+            self.block = CBlock()
+        else:
+            self.block = block
+
+    def deserialize(self, f):
+        self.block.deserialize(f)
+
+    def serialize(self):
+        return self.block.serialize()
+
+    def __repr__(self):
+        return "msg_block(block=%s)" % (repr(self.block))
+
+# for cases where a user needs tighter control over what is sent over the wire
+# note that the user must supply the name of the command, and the data
+class msg_generic():
+    def __init__(self, command, data=None):
+        self.command = command
+        self.data = data
+
+    def serialize(self):
+        return self.data
+
+    def __repr__(self):
+        return "msg_generic()"
+
+class msg_witness_block(msg_block):
+
+    def serialize(self):
+        r = self.block.serialize(with_witness=True)
+        return r
+
+class msg_getaddr():
+    command = b"getaddr"
+
+    def __init__(self):
+        pass
+
+    def deserialize(self, f):
+        pass
+
+    def serialize(self):
+        return b""
+
+    def __repr__(self):
+        return "msg_getaddr()"
+
+
+class msg_ping():
+    command = b"ping"
+
+    def __init__(self, nonce=0):
+        self.nonce = nonce
+
+    def deserialize(self, f):
+        self.nonce = struct.unpack("<Q", f.read(8))[0]
+
+    def serialize(self):
+        r = b""
+        r += struct.pack("<Q", self.nonce)
+        return r
+
+    def __repr__(self):
+        return "msg_ping(nonce=%08x)" % self.nonce
+
+
+class msg_pong():
+    command = b"pong"
+
+    def __init__(self, nonce=0):
+        self.nonce = nonce
+
+    def deserialize(self, f):
+        self.nonce = struct.unpack("<Q", f.read(8))[0]
+
+    def serialize(self):
+        r = b""
+        r += struct.pack("<Q", self.nonce)
+        return r
+
+    def __repr__(self):
+        return "msg_pong(nonce=%08x)" % self.nonce
+
+
+class msg_mempool():
+    command = b"mempool"
+
+    def __init__(self):
+        pass
+
+    def deserialize(self, f):
+        pass
+
+    def serialize(self):
+        return b""
+
+    def __repr__(self):
+        return "msg_mempool()"
+
+class msg_sendheaders():
+    command = b"sendheaders"
+
+    def __init__(self):
+        pass
+
+    def deserialize(self, f):
+        pass
+
+    def serialize(self):
+        return b""
+
+    def __repr__(self):
+        return "msg_sendheaders()"
+
+
+# getheaders message has
+# number of entries
+# vector of hashes
+# hash_stop (hash of last desired block header, 0 to get as many as possible)
+class msg_getheaders():
+    command = b"getheaders"
+
+    def __init__(self):
+        self.locator = CBlockLocator()
+        self.hashstop = 0
+
+    def deserialize(self, f):
+        self.locator = CBlockLocator()
+        self.locator.deserialize(f)
+        self.hashstop = deser_uint256(f)
+
+    def serialize(self):
+        r = b""
+        r += self.locator.serialize()
+        r += ser_uint256(self.hashstop)
+        return r
+
+    def __repr__(self):
+        return "msg_getheaders(locator=%s, stop=%064x)" \
+            % (repr(self.locator), self.hashstop)
+
+
+# headers message has
+# <count> <vector of block headers>
+class msg_headers():
+    command = b"headers"
+
+    def __init__(self, headers=None):
+        self.headers = headers if headers is not None else []
+
+    def deserialize(self, f):
+        # comment in bitcoind indicates these should be deserialized as blocks
+        blocks = deser_vector(f, CBlock)
+        for x in blocks:
+            self.headers.append(CBlockHeader(x))
+
+    def serialize(self):
+        blocks = [CBlock(x) for x in self.headers]
+        return ser_vector(blocks)
+
+    def __repr__(self):
+        return "msg_headers(headers=%s)" % repr(self.headers)
+
+
+class msg_reject():
+    command = b"reject"
+    REJECT_MALFORMED = 1
+
+    def __init__(self):
+        self.message = b""
+        self.code = 0
+        self.reason = b""
+        self.data = 0
+
+    def deserialize(self, f):
+        self.message = deser_string(f)
+        self.code = struct.unpack("<B", f.read(1))[0]
+        self.reason = deser_string(f)
+        if (self.code != self.REJECT_MALFORMED and
+                (self.message == b"block" or self.message == b"tx")):
+            self.data = deser_uint256(f)
+
+    def serialize(self):
+        r = ser_string(self.message)
+        r += struct.pack("<B", self.code)
+        r += ser_string(self.reason)
+        if (self.code != self.REJECT_MALFORMED and
+                (self.message == b"block" or self.message == b"tx")):
+            r += ser_uint256(self.data)
+        return r
+
+    def __repr__(self):
+        return "msg_reject: %s %d %s [%064x]" \
+            % (self.message, self.code, self.reason, self.data)
+
+class msg_feefilter():
+    command = b"feefilter"
+
+    def __init__(self, feerate=0):
+        self.feerate = feerate
+
+    def deserialize(self, f):
+        self.feerate = struct.unpack("<Q", f.read(8))[0]
+
+    def serialize(self):
+        r = b""
+        r += struct.pack("<Q", self.feerate)
+        return r
+
+    def __repr__(self):
+        return "msg_feefilter(feerate=%08x)" % self.feerate
+
+class msg_sendcmpct():
+    command = b"sendcmpct"
+
+    def __init__(self):
+        self.announce = False
+        self.version = 1
+
+    def deserialize(self, f):
+        self.announce = struct.unpack("<?", f.read(1))[0]
+        self.version = struct.unpack("<Q", f.read(8))[0]
+
+    def serialize(self):
+        r = b""
+        r += struct.pack("<?", self.announce)
+        r += struct.pack("<Q", self.version)
+        return r
+
+    def __repr__(self):
+        return "msg_sendcmpct(announce=%s, version=%lu)" % (self.announce, self.version)
+
+class msg_cmpctblock():
+    command = b"cmpctblock"
+
+    def __init__(self, header_and_shortids = None):
+        self.header_and_shortids = header_and_shortids
+
+    def deserialize(self, f):
+        self.header_and_shortids = P2PHeaderAndShortIDs()
+        self.header_and_shortids.deserialize(f)
+
+    def serialize(self):
+        r = b""
+        r += self.header_and_shortids.serialize()
+        return r
+
+    def __repr__(self):
+        return "msg_cmpctblock(HeaderAndShortIDs=%s)" % repr(self.header_and_shortids)
+
+class msg_getblocktxn():
+    command = b"getblocktxn"
+
+    def __init__(self):
+        self.block_txn_request = None
+
+    def deserialize(self, f):
+        self.block_txn_request = BlockTransactionsRequest()
+        self.block_txn_request.deserialize(f)
+
+    def serialize(self):
+        r = b""
+        r += self.block_txn_request.serialize()
+        return r
+
+    def __repr__(self):
+        return "msg_getblocktxn(block_txn_request=%s)" % (repr(self.block_txn_request))
+
+class msg_blocktxn():
+    command = b"blocktxn"
+
+    def __init__(self):
+        self.block_transactions = BlockTransactions()
+
+    def deserialize(self, f):
+        self.block_transactions.deserialize(f)
+
+    def serialize(self):
+        r = b""
+        r += self.block_transactions.serialize()
+        return r
+
+    def __repr__(self):
+        return "msg_blocktxn(block_transactions=%s)" % (repr(self.block_transactions))
+
+class msg_witness_blocktxn(msg_blocktxn):
+    def serialize(self):
+        r = b""
+        r += self.block_transactions.serialize(with_witness=True)
+        return r
diff --git a/test/functional/test_framework/mininode.py b/test/functional/test_framework/mininode.py
index 24ee09b81c..24c96b5681 100755
--- a/test/functional/test_framework/mininode.py
+++ b/test/functional/test_framework/mininode.py
@@ -12,1337 +12,50 @@ found in the mini-node branch of http://github.com/jgarzik/pynode.
 NodeConn: an object which manages p2p connectivity to a bitcoin node
 NodeConnCB: a base class that describes the interface for receiving
             callbacks with network messages from a NodeConn
-CBlock, CTransaction, CBlockHeader, CTxIn, CTxOut, etc....:
-    data structures that should map to corresponding structures in
-    bitcoin/primitives
-msg_block, msg_tx, msg_headers, etc.:
-    data structures that represent network messages
-ser_*, deser_*: functions that handle serialization/deserialization
 """
-
 import asyncore
-from codecs import encode
 from collections import defaultdict
-import copy
-import hashlib
 from io import BytesIO
 import logging
-import random
 import socket
 import struct
 import sys
 import time
 from threading import RLock, Thread
 
-from test_framework.siphash import siphash256
-from test_framework.util import hex_str_to_bytes, bytes_to_hex_str, wait_until
-
-MIN_VERSION_SUPPORTED = 60001
-MY_VERSION = 70014  # past bip-31 for ping/pong
-MY_SUBVERSION = b"/python-mininode-tester:0.0.3/"
-MY_RELAY = 1 # from version 70001 onwards, fRelay should be appended to version messages (BIP37)
-
-MAX_INV_SZ = 50000
-MAX_BLOCK_BASE_SIZE = 1000000
-
-COIN = 100000000 # 1 btc in satoshis
-
-NODE_NETWORK = (1 << 0)
-# NODE_GETUTXO = (1 << 1)
-# NODE_BLOOM = (1 << 2)
-NODE_WITNESS = (1 << 3)
-NODE_UNSUPPORTED_SERVICE_BIT_5 = (1 << 5)
-NODE_UNSUPPORTED_SERVICE_BIT_7 = (1 << 7)
+from test_framework.messages import *
 
 logger = logging.getLogger("TestFramework.mininode")
 
-# Keep our own socket map for asyncore, so that we can track disconnects
-# ourselves (to workaround an issue with closing an asyncore socket when
-# using select)
-mininode_socket_map = dict()
-
-# One lock for synchronizing all data access between the networking thread (see
-# NetworkThread below) and the thread running the test logic.  For simplicity,
-# NodeConn acquires this lock whenever delivering a message to a NodeConnCB,
-# and whenever adding anything to the send buffer (in send_message()).  This
-# lock should be acquired in the thread running the test logic to synchronize
-# access to any data shared with the NodeConnCB or NodeConn.
-mininode_lock = RLock()
-
-# Serialization/deserialization tools
-def sha256(s):
-    return hashlib.new('sha256', s).digest()
-
-def ripemd160(s):
-    return hashlib.new('ripemd160', s).digest()
-
-def hash256(s):
-    return sha256(sha256(s))
-
-def ser_compact_size(l):
-    r = b""
-    if l < 253:
-        r = struct.pack("B", l)
-    elif l < 0x10000:
-        r = struct.pack("<BH", 253, l)
-    elif l < 0x100000000:
-        r = struct.pack("<BI", 254, l)
-    else:
-        r = struct.pack("<BQ", 255, l)
-    return r
-
-def deser_compact_size(f):
-    nit = struct.unpack("<B", f.read(1))[0]
-    if nit == 253:
-        nit = struct.unpack("<H", f.read(2))[0]
-    elif nit == 254:
-        nit = struct.unpack("<I", f.read(4))[0]
-    elif nit == 255:
-        nit = struct.unpack("<Q", f.read(8))[0]
-    return nit
-
-def deser_string(f):
-    nit = deser_compact_size(f)
-    return f.read(nit)
-
-def ser_string(s):
-    return ser_compact_size(len(s)) + s
-
-def deser_uint256(f):
-    r = 0
-    for i in range(8):
-        t = struct.unpack("<I", f.read(4))[0]
-        r += t << (i * 32)
-    return r
-
-
-def ser_uint256(u):
-    rs = b""
-    for i in range(8):
-        rs += struct.pack("<I", u & 0xFFFFFFFF)
-        u >>= 32
-    return rs
-
-
-def uint256_from_str(s):
-    r = 0
-    t = struct.unpack("<IIIIIIII", s[:32])
-    for i in range(8):
-        r += t[i] << (i * 32)
-    return r
-
-
-def uint256_from_compact(c):
-    nbytes = (c >> 24) & 0xFF
-    v = (c & 0xFFFFFF) << (8 * (nbytes - 3))
-    return v
-
-
-def deser_vector(f, c):
-    nit = deser_compact_size(f)
-    r = []
-    for i in range(nit):
-        t = c()
-        t.deserialize(f)
-        r.append(t)
-    return r
-
-
-# ser_function_name: Allow for an alternate serialization function on the
-# entries in the vector (we use this for serializing the vector of transactions
-# for a witness block).
-def ser_vector(l, ser_function_name=None):
-    r = ser_compact_size(len(l))
-    for i in l:
-        if ser_function_name:
-            r += getattr(i, ser_function_name)()
-        else:
-            r += i.serialize()
-    return r
-
-
-def deser_uint256_vector(f):
-    nit = deser_compact_size(f)
-    r = []
-    for i in range(nit):
-        t = deser_uint256(f)
-        r.append(t)
-    return r
-
-
-def ser_uint256_vector(l):
-    r = ser_compact_size(len(l))
-    for i in l:
-        r += ser_uint256(i)
-    return r
-
-
-def deser_string_vector(f):
-    nit = deser_compact_size(f)
-    r = []
-    for i in range(nit):
-        t = deser_string(f)
-        r.append(t)
-    return r
-
-
-def ser_string_vector(l):
-    r = ser_compact_size(len(l))
-    for sv in l:
-        r += ser_string(sv)
-    return r
-
-
-def deser_int_vector(f):
-    nit = deser_compact_size(f)
-    r = []
-    for i in range(nit):
-        t = struct.unpack("<i", f.read(4))[0]
-        r.append(t)
-    return r
-
-
-def ser_int_vector(l):
-    r = ser_compact_size(len(l))
-    for i in l:
-        r += struct.pack("<i", i)
-    return r
-
-# Deserialize from a hex string representation (eg from RPC)
-def FromHex(obj, hex_string):
-    obj.deserialize(BytesIO(hex_str_to_bytes(hex_string)))
-    return obj
-
-# Convert a binary-serializable object to hex (eg for submission via RPC)
-def ToHex(obj):
-    return bytes_to_hex_str(obj.serialize())
-
-# Objects that map to bitcoind objects, which can be serialized/deserialized
-
-class CAddress():
-    def __init__(self):
-        self.nServices = 1
-        self.pchReserved = b"\x00" * 10 + b"\xff" * 2
-        self.ip = "0.0.0.0"
-        self.port = 0
-
-    def deserialize(self, f):
-        self.nServices = struct.unpack("<Q", f.read(8))[0]
-        self.pchReserved = f.read(12)
-        self.ip = socket.inet_ntoa(f.read(4))
-        self.port = struct.unpack(">H", f.read(2))[0]
-
-    def serialize(self):
-        r = b""
-        r += struct.pack("<Q", self.nServices)
-        r += self.pchReserved
-        r += socket.inet_aton(self.ip)
-        r += struct.pack(">H", self.port)
-        return r
-
-    def __repr__(self):
-        return "CAddress(nServices=%i ip=%s port=%i)" % (self.nServices,
-                                                         self.ip, self.port)
-
-MSG_WITNESS_FLAG = 1<<30
-
-class CInv():
-    typemap = {
-        0: "Error",
-        1: "TX",
-        2: "Block",
-        1|MSG_WITNESS_FLAG: "WitnessTx",
-        2|MSG_WITNESS_FLAG : "WitnessBlock",
-        4: "CompactBlock"
-    }
-
-    def __init__(self, t=0, h=0):
-        self.type = t
-        self.hash = h
-
-    def deserialize(self, f):
-        self.type = struct.unpack("<i", f.read(4))[0]
-        self.hash = deser_uint256(f)
-
-    def serialize(self):
-        r = b""
-        r += struct.pack("<i", self.type)
-        r += ser_uint256(self.hash)
-        return r
-
-    def __repr__(self):
-        return "CInv(type=%s hash=%064x)" \
-            % (self.typemap[self.type], self.hash)
-
-
-class CBlockLocator():
-    def __init__(self):
-        self.nVersion = MY_VERSION
-        self.vHave = []
-
-    def deserialize(self, f):
-        self.nVersion = struct.unpack("<i", f.read(4))[0]
-        self.vHave = deser_uint256_vector(f)
-
-    def serialize(self):
-        r = b""
-        r += struct.pack("<i", self.nVersion)
-        r += ser_uint256_vector(self.vHave)
-        return r
-
-    def __repr__(self):
-        return "CBlockLocator(nVersion=%i vHave=%s)" \
-            % (self.nVersion, repr(self.vHave))
-
-
-class COutPoint():
-    def __init__(self, hash=0, n=0):
-        self.hash = hash
-        self.n = n
-
-    def deserialize(self, f):
-        self.hash = deser_uint256(f)
-        self.n = struct.unpack("<I", f.read(4))[0]
-
-    def serialize(self):
-        r = b""
-        r += ser_uint256(self.hash)
-        r += struct.pack("<I", self.n)
-        return r
-
-    def __repr__(self):
-        return "COutPoint(hash=%064x n=%i)" % (self.hash, self.n)
-
-
-class CTxIn():
-    def __init__(self, outpoint=None, scriptSig=b"", nSequence=0):
-        if outpoint is None:
-            self.prevout = COutPoint()
-        else:
-            self.prevout = outpoint
-        self.scriptSig = scriptSig
-        self.nSequence = nSequence
-
-    def deserialize(self, f):
-        self.prevout = COutPoint()
-        self.prevout.deserialize(f)
-        self.scriptSig = deser_string(f)
-        self.nSequence = struct.unpack("<I", f.read(4))[0]
-
-    def serialize(self):
-        r = b""
-        r += self.prevout.serialize()
-        r += ser_string(self.scriptSig)
-        r += struct.pack("<I", self.nSequence)
-        return r
-
-    def __repr__(self):
-        return "CTxIn(prevout=%s scriptSig=%s nSequence=%i)" \
-            % (repr(self.prevout), bytes_to_hex_str(self.scriptSig),
-               self.nSequence)
-
-
-class CTxOut():
-    def __init__(self, nValue=0, scriptPubKey=b""):
-        self.nValue = nValue
-        self.scriptPubKey = scriptPubKey
-
-    def deserialize(self, f):
-        self.nValue = struct.unpack("<q", f.read(8))[0]
-        self.scriptPubKey = deser_string(f)
-
-    def serialize(self):
-        r = b""
-        r += struct.pack("<q", self.nValue)
-        r += ser_string(self.scriptPubKey)
-        return r
-
-    def __repr__(self):
-        return "CTxOut(nValue=%i.%08i scriptPubKey=%s)" \
-            % (self.nValue // COIN, self.nValue % COIN,
-               bytes_to_hex_str(self.scriptPubKey))
-
-
-class CScriptWitness():
-    def __init__(self):
-        # stack is a vector of strings
-        self.stack = []
-
-    def __repr__(self):
-        return "CScriptWitness(%s)" % \
-               (",".join([bytes_to_hex_str(x) for x in self.stack]))
-
-    def is_null(self):
-        if self.stack:
-            return False
-        return True
-
-
-class CTxInWitness():
-    def __init__(self):
-        self.scriptWitness = CScriptWitness()
-
-    def deserialize(self, f):
-        self.scriptWitness.stack = deser_string_vector(f)
-
-    def serialize(self):
-        return ser_string_vector(self.scriptWitness.stack)
-
-    def __repr__(self):
-        return repr(self.scriptWitness)
-
-    def is_null(self):
-        return self.scriptWitness.is_null()
-
-
-class CTxWitness():
-    def __init__(self):
-        self.vtxinwit = []
-
-    def deserialize(self, f):
-        for i in range(len(self.vtxinwit)):
-            self.vtxinwit[i].deserialize(f)
-
-    def serialize(self):
-        r = b""
-        # This is different than the usual vector serialization --
-        # we omit the length of the vector, which is required to be
-        # the same length as the transaction's vin vector.
-        for x in self.vtxinwit:
-            r += x.serialize()
-        return r
-
-    def __repr__(self):
-        return "CTxWitness(%s)" % \
-               (';'.join([repr(x) for x in self.vtxinwit]))
-
-    def is_null(self):
-        for x in self.vtxinwit:
-            if not x.is_null():
-                return False
-        return True
-
-
-class CTransaction():
-    def __init__(self, tx=None):
-        if tx is None:
-            self.nVersion = 1
-            self.vin = []
-            self.vout = []
-            self.wit = CTxWitness()
-            self.nLockTime = 0
-            self.sha256 = None
-            self.hash = None
-        else:
-            self.nVersion = tx.nVersion
-            self.vin = copy.deepcopy(tx.vin)
-            self.vout = copy.deepcopy(tx.vout)
-            self.nLockTime = tx.nLockTime
-            self.sha256 = tx.sha256
-            self.hash = tx.hash
-            self.wit = copy.deepcopy(tx.wit)
-
-    def deserialize(self, f):
-        self.nVersion = struct.unpack("<i", f.read(4))[0]
-        self.vin = deser_vector(f, CTxIn)
-        flags = 0
-        if len(self.vin) == 0:
-            flags = struct.unpack("<B", f.read(1))[0]
-            # Not sure why flags can't be zero, but this
-            # matches the implementation in bitcoind
-            if (flags != 0):
-                self.vin = deser_vector(f, CTxIn)
-                self.vout = deser_vector(f, CTxOut)
-        else:
-            self.vout = deser_vector(f, CTxOut)
-        if flags != 0:
-            self.wit.vtxinwit = [CTxInWitness() for i in range(len(self.vin))]
-            self.wit.deserialize(f)
-        self.nLockTime = struct.unpack("<I", f.read(4))[0]
-        self.sha256 = None
-        self.hash = None
-
-    def serialize_without_witness(self):
-        r = b""
-        r += struct.pack("<i", self.nVersion)
-        r += ser_vector(self.vin)
-        r += ser_vector(self.vout)
-        r += struct.pack("<I", self.nLockTime)
-        return r
-
-    # Only serialize with witness when explicitly called for
-    def serialize_with_witness(self):
-        flags = 0
-        if not self.wit.is_null():
-            flags |= 1
-        r = b""
-        r += struct.pack("<i", self.nVersion)
-        if flags:
-            dummy = []
-            r += ser_vector(dummy)
-            r += struct.pack("<B", flags)
-        r += ser_vector(self.vin)
-        r += ser_vector(self.vout)
-        if flags & 1:
-            if (len(self.wit.vtxinwit) != len(self.vin)):
-                # vtxinwit must have the same length as vin
-                self.wit.vtxinwit = self.wit.vtxinwit[:len(self.vin)]
-                for i in range(len(self.wit.vtxinwit), len(self.vin)):
-                    self.wit.vtxinwit.append(CTxInWitness())
-            r += self.wit.serialize()
-        r += struct.pack("<I", self.nLockTime)
-        return r
-
-    # Regular serialization is without witness -- must explicitly
-    # call serialize_with_witness to include witness data.
-    def serialize(self):
-        return self.serialize_without_witness()
-
-    # Recalculate the txid (transaction hash without witness)
-    def rehash(self):
-        self.sha256 = None
-        self.calc_sha256()
-
-    # We will only cache the serialization without witness in
-    # self.sha256 and self.hash -- those are expected to be the txid.
-    def calc_sha256(self, with_witness=False):
-        if with_witness:
-            # Don't cache the result, just return it
-            return uint256_from_str(hash256(self.serialize_with_witness()))
-
-        if self.sha256 is None:
-            self.sha256 = uint256_from_str(hash256(self.serialize_without_witness()))
-        self.hash = encode(hash256(self.serialize())[::-1], 'hex_codec').decode('ascii')
-
-    def is_valid(self):
-        self.calc_sha256()
-        for tout in self.vout:
-            if tout.nValue < 0 or tout.nValue > 21000000 * COIN:
-                return False
-        return True
-
-    def __repr__(self):
-        return "CTransaction(nVersion=%i vin=%s vout=%s wit=%s nLockTime=%i)" \
-            % (self.nVersion, repr(self.vin), repr(self.vout), repr(self.wit), self.nLockTime)
-
-
-class CBlockHeader():
-    def __init__(self, header=None):
-        if header is None:
-            self.set_null()
-        else:
-            self.nVersion = header.nVersion
-            self.hashPrevBlock = header.hashPrevBlock
-            self.hashMerkleRoot = header.hashMerkleRoot
-            self.nTime = header.nTime
-            self.nBits = header.nBits
-            self.nNonce = header.nNonce
-            self.sha256 = header.sha256
-            self.hash = header.hash
-            self.calc_sha256()
-
-    def set_null(self):
-        self.nVersion = 1
-        self.hashPrevBlock = 0
-        self.hashMerkleRoot = 0
-        self.nTime = 0
-        self.nBits = 0
-        self.nNonce = 0
-        self.sha256 = None
-        self.hash = None
-
-    def deserialize(self, f):
-        self.nVersion = struct.unpack("<i", f.read(4))[0]
-        self.hashPrevBlock = deser_uint256(f)
-        self.hashMerkleRoot = deser_uint256(f)
-        self.nTime = struct.unpack("<I", f.read(4))[0]
-        self.nBits = struct.unpack("<I", f.read(4))[0]
-        self.nNonce = struct.unpack("<I", f.read(4))[0]
-        self.sha256 = None
-        self.hash = None
-
-    def serialize(self):
-        r = b""
-        r += struct.pack("<i", self.nVersion)
-        r += ser_uint256(self.hashPrevBlock)
-        r += ser_uint256(self.hashMerkleRoot)
-        r += struct.pack("<I", self.nTime)
-        r += struct.pack("<I", self.nBits)
-        r += struct.pack("<I", self.nNonce)
-        return r
-
-    def calc_sha256(self):
-        if self.sha256 is None:
-            r = b""
-            r += struct.pack("<i", self.nVersion)
-            r += ser_uint256(self.hashPrevBlock)
-            r += ser_uint256(self.hashMerkleRoot)
-            r += struct.pack("<I", self.nTime)
-            r += struct.pack("<I", self.nBits)
-            r += struct.pack("<I", self.nNonce)
-            self.sha256 = uint256_from_str(hash256(r))
-            self.hash = encode(hash256(r)[::-1], 'hex_codec').decode('ascii')
-
-    def rehash(self):
-        self.sha256 = None
-        self.calc_sha256()
-        return self.sha256
-
-    def __repr__(self):
-        return "CBlockHeader(nVersion=%i hashPrevBlock=%064x hashMerkleRoot=%064x nTime=%s nBits=%08x nNonce=%08x)" \
-            % (self.nVersion, self.hashPrevBlock, self.hashMerkleRoot,
-               time.ctime(self.nTime), self.nBits, self.nNonce)
-
-
-class CBlock(CBlockHeader):
-    def __init__(self, header=None):
-        super(CBlock, self).__init__(header)
-        self.vtx = []
-
-    def deserialize(self, f):
-        super(CBlock, self).deserialize(f)
-        self.vtx = deser_vector(f, CTransaction)
-
-    def serialize(self, with_witness=False):
-        r = b""
-        r += super(CBlock, self).serialize()
-        if with_witness:
-            r += ser_vector(self.vtx, "serialize_with_witness")
-        else:
-            r += ser_vector(self.vtx)
-        return r
-
-    # Calculate the merkle root given a vector of transaction hashes
-    @classmethod
-    def get_merkle_root(cls, hashes):
-        while len(hashes) > 1:
-            newhashes = []
-            for i in range(0, len(hashes), 2):
-                i2 = min(i+1, len(hashes)-1)
-                newhashes.append(hash256(hashes[i] + hashes[i2]))
-            hashes = newhashes
-        return uint256_from_str(hashes[0])
-
-    def calc_merkle_root(self):
-        hashes = []
-        for tx in self.vtx:
-            tx.calc_sha256()
-            hashes.append(ser_uint256(tx.sha256))
-        return self.get_merkle_root(hashes)
-
-    def calc_witness_merkle_root(self):
-        # For witness root purposes, the hash of the
-        # coinbase, with witness, is defined to be 0...0
-        hashes = [ser_uint256(0)]
-
-        for tx in self.vtx[1:]:
-            # Calculate the hashes with witness data
-            hashes.append(ser_uint256(tx.calc_sha256(True)))
-
-        return self.get_merkle_root(hashes)
-
-    def is_valid(self):
-        self.calc_sha256()
-        target = uint256_from_compact(self.nBits)
-        if self.sha256 > target:
-            return False
-        for tx in self.vtx:
-            if not tx.is_valid():
-                return False
-        if self.calc_merkle_root() != self.hashMerkleRoot:
-            return False
-        return True
-
-    def solve(self):
-        self.rehash()
-        target = uint256_from_compact(self.nBits)
-        while self.sha256 > target:
-            self.nNonce += 1
-            self.rehash()
-
-    def __repr__(self):
-        return "CBlock(nVersion=%i hashPrevBlock=%064x hashMerkleRoot=%064x nTime=%s nBits=%08x nNonce=%08x vtx=%s)" \
-            % (self.nVersion, self.hashPrevBlock, self.hashMerkleRoot,
-               time.ctime(self.nTime), self.nBits, self.nNonce, repr(self.vtx))
-
-
-class PrefilledTransaction():
-    def __init__(self, index=0, tx = None):
-        self.index = index
-        self.tx = tx
-
-    def deserialize(self, f):
-        self.index = deser_compact_size(f)
-        self.tx = CTransaction()
-        self.tx.deserialize(f)
-
-    def serialize(self, with_witness=False):
-        r = b""
-        r += ser_compact_size(self.index)
-        if with_witness:
-            r += self.tx.serialize_with_witness()
-        else:
-            r += self.tx.serialize_without_witness()
-        return r
-
-    def serialize_with_witness(self):
-        return self.serialize(with_witness=True)
-
-    def __repr__(self):
-        return "PrefilledTransaction(index=%d, tx=%s)" % (self.index, repr(self.tx))
-
-# This is what we send on the wire, in a cmpctblock message.
-class P2PHeaderAndShortIDs():
-    def __init__(self):
-        self.header = CBlockHeader()
-        self.nonce = 0
-        self.shortids_length = 0
-        self.shortids = []
-        self.prefilled_txn_length = 0
-        self.prefilled_txn = []
-
-    def deserialize(self, f):
-        self.header.deserialize(f)
-        self.nonce = struct.unpack("<Q", f.read(8))[0]
-        self.shortids_length = deser_compact_size(f)
-        for i in range(self.shortids_length):
-            # shortids are defined to be 6 bytes in the spec, so append
-            # two zero bytes and read it in as an 8-byte number
-            self.shortids.append(struct.unpack("<Q", f.read(6) + b'\x00\x00')[0])
-        self.prefilled_txn = deser_vector(f, PrefilledTransaction)
-        self.prefilled_txn_length = len(self.prefilled_txn)
-
-    # When using version 2 compact blocks, we must serialize with_witness.
-    def serialize(self, with_witness=False):
-        r = b""
-        r += self.header.serialize()
-        r += struct.pack("<Q", self.nonce)
-        r += ser_compact_size(self.shortids_length)
-        for x in self.shortids:
-            # We only want the first 6 bytes
-            r += struct.pack("<Q", x)[0:6]
-        if with_witness:
-            r += ser_vector(self.prefilled_txn, "serialize_with_witness")
-        else:
-            r += ser_vector(self.prefilled_txn)
-        return r
-
-    def __repr__(self):
-        return "P2PHeaderAndShortIDs(header=%s, nonce=%d, shortids_length=%d, shortids=%s, prefilled_txn_length=%d, prefilledtxn=%s" % (repr(self.header), self.nonce, self.shortids_length, repr(self.shortids), self.prefilled_txn_length, repr(self.prefilled_txn))
-
-# P2P version of the above that will use witness serialization (for compact
-# block version 2)
-class P2PHeaderAndShortWitnessIDs(P2PHeaderAndShortIDs):
-    def serialize(self):
-        return super(P2PHeaderAndShortWitnessIDs, self).serialize(with_witness=True)
-
-# Calculate the BIP 152-compact blocks shortid for a given transaction hash
-def calculate_shortid(k0, k1, tx_hash):
-    expected_shortid = siphash256(k0, k1, tx_hash)
-    expected_shortid &= 0x0000ffffffffffff
-    return expected_shortid
-
-# This version gets rid of the array lengths, and reinterprets the differential
-# encoding into indices that can be used for lookup.
-class HeaderAndShortIDs():
-    def __init__(self, p2pheaders_and_shortids = None):
-        self.header = CBlockHeader()
-        self.nonce = 0
-        self.shortids = []
-        self.prefilled_txn = []
-        self.use_witness = False
-
-        if p2pheaders_and_shortids != None:
-            self.header = p2pheaders_and_shortids.header
-            self.nonce = p2pheaders_and_shortids.nonce
-            self.shortids = p2pheaders_and_shortids.shortids
-            last_index = -1
-            for x in p2pheaders_and_shortids.prefilled_txn:
-                self.prefilled_txn.append(PrefilledTransaction(x.index + last_index + 1, x.tx))
-                last_index = self.prefilled_txn[-1].index
-
-    def to_p2p(self):
-        if self.use_witness:
-            ret = P2PHeaderAndShortWitnessIDs()
-        else:
-            ret = P2PHeaderAndShortIDs()
-        ret.header = self.header
-        ret.nonce = self.nonce
-        ret.shortids_length = len(self.shortids)
-        ret.shortids = self.shortids
-        ret.prefilled_txn_length = len(self.prefilled_txn)
-        ret.prefilled_txn = []
-        last_index = -1
-        for x in self.prefilled_txn:
-            ret.prefilled_txn.append(PrefilledTransaction(x.index - last_index - 1, x.tx))
-            last_index = x.index
-        return ret
-
-    def get_siphash_keys(self):
-        header_nonce = self.header.serialize()
-        header_nonce += struct.pack("<Q", self.nonce)
-        hash_header_nonce_as_str = sha256(header_nonce)
-        key0 = struct.unpack("<Q", hash_header_nonce_as_str[0:8])[0]
-        key1 = struct.unpack("<Q", hash_header_nonce_as_str[8:16])[0]
-        return [ key0, key1 ]
-
-    # Version 2 compact blocks use wtxid in shortids (rather than txid)
-    def initialize_from_block(self, block, nonce=0, prefill_list = [0], use_witness = False):
-        self.header = CBlockHeader(block)
-        self.nonce = nonce
-        self.prefilled_txn = [ PrefilledTransaction(i, block.vtx[i]) for i in prefill_list ]
-        self.shortids = []
-        self.use_witness = use_witness
-        [k0, k1] = self.get_siphash_keys()
-        for i in range(len(block.vtx)):
-            if i not in prefill_list:
-                tx_hash = block.vtx[i].sha256
-                if use_witness:
-                    tx_hash = block.vtx[i].calc_sha256(with_witness=True)
-                self.shortids.append(calculate_shortid(k0, k1, tx_hash))
-
-    def __repr__(self):
-        return "HeaderAndShortIDs(header=%s, nonce=%d, shortids=%s, prefilledtxn=%s" % (repr(self.header), self.nonce, repr(self.shortids), repr(self.prefilled_txn))
-
-
-class BlockTransactionsRequest():
-
-    def __init__(self, blockhash=0, indexes = None):
-        self.blockhash = blockhash
-        self.indexes = indexes if indexes != None else []
-
-    def deserialize(self, f):
-        self.blockhash = deser_uint256(f)
-        indexes_length = deser_compact_size(f)
-        for i in range(indexes_length):
-            self.indexes.append(deser_compact_size(f))
-
-    def serialize(self):
-        r = b""
-        r += ser_uint256(self.blockhash)
-        r += ser_compact_size(len(self.indexes))
-        for x in self.indexes:
-            r += ser_compact_size(x)
-        return r
-
-    # helper to set the differentially encoded indexes from absolute ones
-    def from_absolute(self, absolute_indexes):
-        self.indexes = []
-        last_index = -1
-        for x in absolute_indexes:
-            self.indexes.append(x-last_index-1)
-            last_index = x
-
-    def to_absolute(self):
-        absolute_indexes = []
-        last_index = -1
-        for x in self.indexes:
-            absolute_indexes.append(x+last_index+1)
-            last_index = absolute_indexes[-1]
-        return absolute_indexes
-
-    def __repr__(self):
-        return "BlockTransactionsRequest(hash=%064x indexes=%s)" % (self.blockhash, repr(self.indexes))
-
-
-class BlockTransactions():
-
-    def __init__(self, blockhash=0, transactions = None):
-        self.blockhash = blockhash
-        self.transactions = transactions if transactions != None else []
-
-    def deserialize(self, f):
-        self.blockhash = deser_uint256(f)
-        self.transactions = deser_vector(f, CTransaction)
-
-    def serialize(self, with_witness=False):
-        r = b""
-        r += ser_uint256(self.blockhash)
-        if with_witness:
-            r += ser_vector(self.transactions, "serialize_with_witness")
-        else:
-            r += ser_vector(self.transactions)
-        return r
-
-    def __repr__(self):
-        return "BlockTransactions(hash=%064x transactions=%s)" % (self.blockhash, repr(self.transactions))
-
-
-# Objects that correspond to messages on the wire
-class msg_version():
-    command = b"version"
-
-    def __init__(self):
-        self.nVersion = MY_VERSION
-        self.nServices = NODE_NETWORK | NODE_WITNESS
-        self.nTime = int(time.time())
-        self.addrTo = CAddress()
-        self.addrFrom = CAddress()
-        self.nNonce = random.getrandbits(64)
-        self.strSubVer = MY_SUBVERSION
-        self.nStartingHeight = -1
-        self.nRelay = MY_RELAY
-
-    def deserialize(self, f):
-        self.nVersion = struct.unpack("<i", f.read(4))[0]
-        if self.nVersion == 10300:
-            self.nVersion = 300
-        self.nServices = struct.unpack("<Q", f.read(8))[0]
-        self.nTime = struct.unpack("<q", f.read(8))[0]
-        self.addrTo = CAddress()
-        self.addrTo.deserialize(f)
-
-        if self.nVersion >= 106:
-            self.addrFrom = CAddress()
-            self.addrFrom.deserialize(f)
-            self.nNonce = struct.unpack("<Q", f.read(8))[0]
-            self.strSubVer = deser_string(f)
-        else:
-            self.addrFrom = None
-            self.nNonce = None
-            self.strSubVer = None
-            self.nStartingHeight = None
-
-        if self.nVersion >= 209:
-            self.nStartingHeight = struct.unpack("<i", f.read(4))[0]
-        else:
-            self.nStartingHeight = None
-
-        if self.nVersion >= 70001:
-            # Relay field is optional for version 70001 onwards
-            try:
-                self.nRelay = struct.unpack("<b", f.read(1))[0]
-            except:
-                self.nRelay = 0
-        else:
-            self.nRelay = 0
-
-    def serialize(self):
-        r = b""
-        r += struct.pack("<i", self.nVersion)
-        r += struct.pack("<Q", self.nServices)
-        r += struct.pack("<q", self.nTime)
-        r += self.addrTo.serialize()
-        r += self.addrFrom.serialize()
-        r += struct.pack("<Q", self.nNonce)
-        r += ser_string(self.strSubVer)
-        r += struct.pack("<i", self.nStartingHeight)
-        r += struct.pack("<b", self.nRelay)
-        return r
-
-    def __repr__(self):
-        return 'msg_version(nVersion=%i nServices=%i nTime=%s addrTo=%s addrFrom=%s nNonce=0x%016X strSubVer=%s nStartingHeight=%i nRelay=%i)' \
-            % (self.nVersion, self.nServices, time.ctime(self.nTime),
-               repr(self.addrTo), repr(self.addrFrom), self.nNonce,
-               self.strSubVer, self.nStartingHeight, self.nRelay)
-
-
-class msg_verack():
-    command = b"verack"
-
-    def __init__(self):
-        pass
-
-    def deserialize(self, f):
-        pass
-
-    def serialize(self):
-        return b""
-
-    def __repr__(self):
-        return "msg_verack()"
-
-
-class msg_addr():
-    command = b"addr"
-
-    def __init__(self):
-        self.addrs = []
-
-    def deserialize(self, f):
-        self.addrs = deser_vector(f, CAddress)
-
-    def serialize(self):
-        return ser_vector(self.addrs)
-
-    def __repr__(self):
-        return "msg_addr(addrs=%s)" % (repr(self.addrs))
-
-
-class msg_inv():
-    command = b"inv"
-
-    def __init__(self, inv=None):
-        if inv is None:
-            self.inv = []
-        else:
-            self.inv = inv
-
-    def deserialize(self, f):
-        self.inv = deser_vector(f, CInv)
-
-    def serialize(self):
-        return ser_vector(self.inv)
-
-    def __repr__(self):
-        return "msg_inv(inv=%s)" % (repr(self.inv))
-
-
-class msg_getdata():
-    command = b"getdata"
-
-    def __init__(self, inv=None):
-        self.inv = inv if inv != None else []
-
-    def deserialize(self, f):
-        self.inv = deser_vector(f, CInv)
-
-    def serialize(self):
-        return ser_vector(self.inv)
-
-    def __repr__(self):
-        return "msg_getdata(inv=%s)" % (repr(self.inv))
-
-
-class msg_getblocks():
-    command = b"getblocks"
-
-    def __init__(self):
-        self.locator = CBlockLocator()
-        self.hashstop = 0
-
-    def deserialize(self, f):
-        self.locator = CBlockLocator()
-        self.locator.deserialize(f)
-        self.hashstop = deser_uint256(f)
-
-    def serialize(self):
-        r = b""
-        r += self.locator.serialize()
-        r += ser_uint256(self.hashstop)
-        return r
-
-    def __repr__(self):
-        return "msg_getblocks(locator=%s hashstop=%064x)" \
-            % (repr(self.locator), self.hashstop)
-
-
-class msg_tx():
-    command = b"tx"
-
-    def __init__(self, tx=CTransaction()):
-        self.tx = tx
-
-    def deserialize(self, f):
-        self.tx.deserialize(f)
-
-    def serialize(self):
-        return self.tx.serialize_without_witness()
-
-    def __repr__(self):
-        return "msg_tx(tx=%s)" % (repr(self.tx))
-
-class msg_witness_tx(msg_tx):
-
-    def serialize(self):
-        return self.tx.serialize_with_witness()
-
-
-class msg_block():
-    command = b"block"
-
-    def __init__(self, block=None):
-        if block is None:
-            self.block = CBlock()
-        else:
-            self.block = block
-
-    def deserialize(self, f):
-        self.block.deserialize(f)
-
-    def serialize(self):
-        return self.block.serialize()
-
-    def __repr__(self):
-        return "msg_block(block=%s)" % (repr(self.block))
-
-# for cases where a user needs tighter control over what is sent over the wire
-# note that the user must supply the name of the command, and the data
-class msg_generic():
-    def __init__(self, command, data=None):
-        self.command = command
-        self.data = data
-
-    def serialize(self):
-        return self.data
-
-    def __repr__(self):
-        return "msg_generic()"
-
-class msg_witness_block(msg_block):
-
-    def serialize(self):
-        r = self.block.serialize(with_witness=True)
-        return r
-
-class msg_getaddr():
-    command = b"getaddr"
-
-    def __init__(self):
-        pass
-
-    def deserialize(self, f):
-        pass
-
-    def serialize(self):
-        return b""
-
-    def __repr__(self):
-        return "msg_getaddr()"
-
-
-class msg_ping():
-    command = b"ping"
-
-    def __init__(self, nonce=0):
-        self.nonce = nonce
-
-    def deserialize(self, f):
-        self.nonce = struct.unpack("<Q", f.read(8))[0]
-
-    def serialize(self):
-        r = b""
-        r += struct.pack("<Q", self.nonce)
-        return r
-
-    def __repr__(self):
-        return "msg_ping(nonce=%08x)" % self.nonce
-
-
-class msg_pong():
-    command = b"pong"
-
-    def __init__(self, nonce=0):
-        self.nonce = nonce
-
-    def deserialize(self, f):
-        self.nonce = struct.unpack("<Q", f.read(8))[0]
-
-    def serialize(self):
-        r = b""
-        r += struct.pack("<Q", self.nonce)
-        return r
-
-    def __repr__(self):
-        return "msg_pong(nonce=%08x)" % self.nonce
-
-
-class msg_mempool():
-    command = b"mempool"
-
-    def __init__(self):
-        pass
-
-    def deserialize(self, f):
-        pass
-
-    def serialize(self):
-        return b""
-
-    def __repr__(self):
-        return "msg_mempool()"
-
-class msg_sendheaders():
-    command = b"sendheaders"
-
-    def __init__(self):
-        pass
-
-    def deserialize(self, f):
-        pass
-
-    def serialize(self):
-        return b""
-
-    def __repr__(self):
-        return "msg_sendheaders()"
-
-
-# getheaders message has
-# number of entries
-# vector of hashes
-# hash_stop (hash of last desired block header, 0 to get as many as possible)
-class msg_getheaders():
-    command = b"getheaders"
-
-    def __init__(self):
-        self.locator = CBlockLocator()
-        self.hashstop = 0
-
-    def deserialize(self, f):
-        self.locator = CBlockLocator()
-        self.locator.deserialize(f)
-        self.hashstop = deser_uint256(f)
-
-    def serialize(self):
-        r = b""
-        r += self.locator.serialize()
-        r += ser_uint256(self.hashstop)
-        return r
-
-    def __repr__(self):
-        return "msg_getheaders(locator=%s, stop=%064x)" \
-            % (repr(self.locator), self.hashstop)
-
-
-# headers message has
-# <count> <vector of block headers>
-class msg_headers():
-    command = b"headers"
-
-    def __init__(self, headers=None):
-        self.headers = headers if headers is not None else []
-
-    def deserialize(self, f):
-        # comment in bitcoind indicates these should be deserialized as blocks
-        blocks = deser_vector(f, CBlock)
-        for x in blocks:
-            self.headers.append(CBlockHeader(x))
-
-    def serialize(self):
-        blocks = [CBlock(x) for x in self.headers]
-        return ser_vector(blocks)
-
-    def __repr__(self):
-        return "msg_headers(headers=%s)" % repr(self.headers)
-
-
-class msg_reject():
-    command = b"reject"
-    REJECT_MALFORMED = 1
-
-    def __init__(self):
-        self.message = b""
-        self.code = 0
-        self.reason = b""
-        self.data = 0
-
-    def deserialize(self, f):
-        self.message = deser_string(f)
-        self.code = struct.unpack("<B", f.read(1))[0]
-        self.reason = deser_string(f)
-        if (self.code != self.REJECT_MALFORMED and
-                (self.message == b"block" or self.message == b"tx")):
-            self.data = deser_uint256(f)
-
-    def serialize(self):
-        r = ser_string(self.message)
-        r += struct.pack("<B", self.code)
-        r += ser_string(self.reason)
-        if (self.code != self.REJECT_MALFORMED and
-                (self.message == b"block" or self.message == b"tx")):
-            r += ser_uint256(self.data)
-        return r
-
-    def __repr__(self):
-        return "msg_reject: %s %d %s [%064x]" \
-            % (self.message, self.code, self.reason, self.data)
-
-class msg_feefilter():
-    command = b"feefilter"
-
-    def __init__(self, feerate=0):
-        self.feerate = feerate
-
-    def deserialize(self, f):
-        self.feerate = struct.unpack("<Q", f.read(8))[0]
-
-    def serialize(self):
-        r = b""
-        r += struct.pack("<Q", self.feerate)
-        return r
-
-    def __repr__(self):
-        return "msg_feefilter(feerate=%08x)" % self.feerate
-
-class msg_sendcmpct():
-    command = b"sendcmpct"
-
-    def __init__(self):
-        self.announce = False
-        self.version = 1
-
-    def deserialize(self, f):
-        self.announce = struct.unpack("<?", f.read(1))[0]
-        self.version = struct.unpack("<Q", f.read(8))[0]
-
-    def serialize(self):
-        r = b""
-        r += struct.pack("<?", self.announce)
-        r += struct.pack("<Q", self.version)
-        return r
-
-    def __repr__(self):
-        return "msg_sendcmpct(announce=%s, version=%lu)" % (self.announce, self.version)
-
-class msg_cmpctblock():
-    command = b"cmpctblock"
-
-    def __init__(self, header_and_shortids = None):
-        self.header_and_shortids = header_and_shortids
-
-    def deserialize(self, f):
-        self.header_and_shortids = P2PHeaderAndShortIDs()
-        self.header_and_shortids.deserialize(f)
-
-    def serialize(self):
-        r = b""
-        r += self.header_and_shortids.serialize()
-        return r
-
-    def __repr__(self):
-        return "msg_cmpctblock(HeaderAndShortIDs=%s)" % repr(self.header_and_shortids)
-
-class msg_getblocktxn():
-    command = b"getblocktxn"
-
-    def __init__(self):
-        self.block_txn_request = None
-
-    def deserialize(self, f):
-        self.block_txn_request = BlockTransactionsRequest()
-        self.block_txn_request.deserialize(f)
-
-    def serialize(self):
-        r = b""
-        r += self.block_txn_request.serialize()
-        return r
-
-    def __repr__(self):
-        return "msg_getblocktxn(block_txn_request=%s)" % (repr(self.block_txn_request))
-
-class msg_blocktxn():
-    command = b"blocktxn"
-
-    def __init__(self):
-        self.block_transactions = BlockTransactions()
-
-    def deserialize(self, f):
-        self.block_transactions.deserialize(f)
-
-    def serialize(self):
-        r = b""
-        r += self.block_transactions.serialize()
-        return r
-
-    def __repr__(self):
-        return "msg_blocktxn(block_transactions=%s)" % (repr(self.block_transactions))
-
-class msg_witness_blocktxn(msg_blocktxn):
-    def serialize(self):
-        r = b""
-        r += self.block_transactions.serialize(with_witness=True)
-        return r
+MESSAGEMAP = {
+    b"addr": msg_addr,
+    b"block": msg_block,
+    b"blocktxn": msg_blocktxn,
+    b"cmpctblock": msg_cmpctblock,
+    b"feefilter": msg_feefilter,
+    b"getaddr": msg_getaddr,
+    b"getblocks": msg_getblocks,
+    b"getblocktxn": msg_getblocktxn,
+    b"getdata": msg_getdata,
+    b"getheaders": msg_getheaders,
+    b"headers": msg_headers,
+    b"inv": msg_inv,
+    b"mempool": msg_mempool,
+    b"ping": msg_ping,
+    b"pong": msg_pong,
+    b"reject": msg_reject,
+    b"sendcmpct": msg_sendcmpct,
+    b"sendheaders": msg_sendheaders,
+    b"tx": msg_tx,
+    b"verack": msg_verack,
+    b"version": msg_version,
+}
+
+MAGIC_BYTES = {
+    "mainnet": b"\xf9\xbe\xb4\xd9",   # mainnet
+    "testnet3": b"\x0b\x11\x09\x07",  # testnet3
+    "regtest": b"\xfa\xbf\xb5\xda",   # regtest
+}
 
 class NodeConnCB():
     """Callback and helper functions for P2P connection to a bitcoind node.
@@ -1486,34 +199,6 @@ class NodeConn(asyncore.dispatcher):
     """The actual NodeConn class
 
     This class provides an interface for a p2p connection to a specified node."""
-    messagemap = {
-        b"version": msg_version,
-        b"verack": msg_verack,
-        b"addr": msg_addr,
-        b"inv": msg_inv,
-        b"getdata": msg_getdata,
-        b"getblocks": msg_getblocks,
-        b"tx": msg_tx,
-        b"block": msg_block,
-        b"getaddr": msg_getaddr,
-        b"ping": msg_ping,
-        b"pong": msg_pong,
-        b"headers": msg_headers,
-        b"getheaders": msg_getheaders,
-        b"reject": msg_reject,
-        b"mempool": msg_mempool,
-        b"feefilter": msg_feefilter,
-        b"sendheaders": msg_sendheaders,
-        b"sendcmpct": msg_sendcmpct,
-        b"cmpctblock": msg_cmpctblock,
-        b"getblocktxn": msg_getblocktxn,
-        b"blocktxn": msg_blocktxn
-    }
-    MAGIC_BYTES = {
-        "mainnet": b"\xf9\xbe\xb4\xd9",   # mainnet
-        "testnet3": b"\x0b\x11\x09\x07",  # testnet3
-        "regtest": b"\xfa\xbf\xb5\xda",   # regtest
-    }
 
     def __init__(self, dstaddr, dstport, callback, net="regtest", services=NODE_NETWORK|NODE_WITNESS, send_version=True):
         asyncore.dispatcher.__init__(self, map=mininode_socket_map)
@@ -1547,6 +232,8 @@ class NodeConn(asyncore.dispatcher):
         except:
             self.handle_close()
 
+    # Connection and disconnection methods
+
     def handle_connect(self):
         if self.state != "connected":
             logger.debug("Connected & Listening: %s:%d" % (self.dstaddr, self.dstport))
@@ -1564,44 +251,30 @@ class NodeConn(asyncore.dispatcher):
             pass
         self.cb.on_close(self)
 
+    def disconnect_node(self):
+        """ Disconnect the p2p connection.
+
+        Called by the test logic thread. Causes the p2p connection
+        to be disconnected on the next iteration of the asyncore loop."""
+        self.disconnect = True
+
+    # Socket read methods
+
+    def readable(self):
+        return True
+
     def handle_read(self):
         t = self.recv(8192)
         if len(t) > 0:
             self.recvbuf += t
             self.got_data()
 
-    def readable(self):
-        return True
-
-    def writable(self):
-        with mininode_lock:
-            pre_connection = self.state == "connecting"
-            length = len(self.sendbuf)
-        return (length > 0 or pre_connection)
-
-    def handle_write(self):
-        with mininode_lock:
-            # asyncore does not expose socket connection, only the first read/write
-            # event, thus we must check connection manually here to know when we
-            # actually connect
-            if self.state == "connecting":
-                self.handle_connect()
-            if not self.writable():
-                return
-
-            try:
-                sent = self.send(self.sendbuf)
-            except:
-                self.handle_close()
-                return
-            self.sendbuf = self.sendbuf[sent:]
-
     def got_data(self):
         try:
             while True:
                 if len(self.recvbuf) < 4:
                     return
-                if self.recvbuf[:4] != self.MAGIC_BYTES[self.network]:
+                if self.recvbuf[:4] != MAGIC_BYTES[self.network]:
                     raise ValueError("got garbage %s" % repr(self.recvbuf))
                 if len(self.recvbuf) < 4 + 12 + 4 + 4:
                     return
@@ -1616,23 +289,54 @@ class NodeConn(asyncore.dispatcher):
                 if checksum != h[:4]:
                     raise ValueError("got bad checksum " + repr(self.recvbuf))
                 self.recvbuf = self.recvbuf[4+12+4+4+msglen:]
-                if command not in self.messagemap:
+                if command not in MESSAGEMAP:
                     raise ValueError("Received unknown command from %s:%d: '%s' %s" % (self.dstaddr, self.dstport, command, repr(msg)))
                 f = BytesIO(msg)
-                t = self.messagemap[command]()
+                t = MESSAGEMAP[command]()
                 t.deserialize(f)
                 self.got_message(t)
         except Exception as e:
             logger.exception('Error reading message:', repr(e))
             raise
 
+    def got_message(self, message):
+        if self.last_sent + 30 * 60 < time.time():
+            self.send_message(MESSAGEMAP[b'ping']())
+        self._log_message("receive", message)
+        self.cb.deliver(self, message)
+
+    # Socket write methods
+
+    def writable(self):
+        with mininode_lock:
+            pre_connection = self.state == "connecting"
+            length = len(self.sendbuf)
+        return (length > 0 or pre_connection)
+
+    def handle_write(self):
+        with mininode_lock:
+            # asyncore does not expose socket connection, only the first read/write
+            # event, thus we must check connection manually here to know when we
+            # actually connect
+            if self.state == "connecting":
+                self.handle_connect()
+            if not self.writable():
+                return
+
+            try:
+                sent = self.send(self.sendbuf)
+            except:
+                self.handle_close()
+                return
+            self.sendbuf = self.sendbuf[sent:]
+
     def send_message(self, message, pushbuf=False):
         if self.state != "connected" and not pushbuf:
             raise IOError('Not connected, no pushbuf')
         self._log_message("send", message)
         command = message.command
         data = message.serialize()
-        tmsg = self.MAGIC_BYTES[self.network]
+        tmsg = MAGIC_BYTES[self.network]
         tmsg += command
         tmsg += b"\x00" * (12 - len(command))
         tmsg += struct.pack("<I", len(data))
@@ -1651,11 +355,7 @@ class NodeConn(asyncore.dispatcher):
                 self.sendbuf += tmsg
             self.last_sent = time.time()
 
-    def got_message(self, message):
-        if self.last_sent + 30 * 60 < time.time():
-            self.send_message(self.messagemap[b'ping']())
-        self._log_message("receive", message)
-        self.cb.deliver(self, message)
+    # Class utility methods
 
     def _log_message(self, direction, msg):
         if direction == "send":
@@ -1667,9 +367,19 @@ class NodeConn(asyncore.dispatcher):
             log_message += "... (msg truncated)"
         logger.debug(log_message)
 
-    def disconnect_node(self):
-        self.disconnect = True
 
+# Keep our own socket map for asyncore, so that we can track disconnects
+# ourselves (to workaround an issue with closing an asyncore socket when
+# using select)
+mininode_socket_map = dict()
+
+# One lock for synchronizing all data access between the networking thread (see
+# NetworkThread below) and the thread running the test logic.  For simplicity,
+# NodeConn acquires this lock whenever delivering a message to a NodeConnCB,
+# and whenever adding anything to the send buffer (in send_message()).  This
+# lock should be acquired in the thread running the test logic to synchronize
+# access to any data shared with the NodeConnCB or NodeConn.
+mininode_lock = RLock()
 
 class NetworkThread(Thread):
     def run(self):
@@ -1681,6 +391,6 @@ class NetworkThread(Thread):
             for fd, obj in mininode_socket_map.items():
                 if obj.disconnect:
                     disconnected.append(obj)
-            [ obj.handle_close() for obj in disconnected ]
+            [obj.handle_close() for obj in disconnected]
             asyncore.loop(0.1, use_poll=True, map=mininode_socket_map, count=1)
         logger.debug("Network thread closing")