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test/functional/p2p_invalid_messages.py
- This file was added.
Property | Old Value | New Value |
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File Mode | null | 100755 |
#!/usr/bin/env python3 | |||||
# Copyright (c) 2015-2018 The Bitcoin Core developers | |||||
# Distributed under the MIT software license, see the accompanying | |||||
# file COPYING or http://www.opensource.org/licenses/mit-license.php. | |||||
"""Test node responses to invalid network messages.""" | |||||
import struct | |||||
from test_framework import messages | |||||
from test_framework.mininode import P2PDataStore | |||||
from test_framework.test_framework import BitcoinTestFramework | |||||
class msg_unrecognized: | |||||
"""Nonsensical message. Modeled after similar types in test_framework.messages.""" | |||||
command = b'badmsg' | |||||
def __init__(self, str_data): | |||||
self.str_data = str_data.encode() if not isinstance(str_data, bytes) else str_data | |||||
def serialize(self): | |||||
return messages.ser_string(self.str_data) | |||||
def __repr__(self): | |||||
return "{}(data={})".format(self.command, self.str_data) | |||||
class msg_nametoolong(msg_unrecognized): | |||||
command = b'thisnameiswayyyyyyyyytoolong' | |||||
class InvalidMessagesTest(BitcoinTestFramework): | |||||
def set_test_params(self): | |||||
self.num_nodes = 1 | |||||
self.setup_clean_chain = True | |||||
def run_test(self): | |||||
""" | |||||
0. Send a bunch of large (2MB) messages of an unrecognized type. Check to see | |||||
that it isn't an effective DoS against the node. | |||||
1. Send an oversized (2MB+) message and check that we're disconnected. | |||||
2. Send a few messages with an incorrect data size in the header, ensure the | |||||
messages are ignored. | |||||
3. Send an unrecognized message with a command name longer than 12 characters. | |||||
""" | |||||
node = self.nodes[0] | |||||
self.node = node | |||||
node.add_p2p_connection(P2PDataStore()) | |||||
conn2 = node.add_p2p_connection(P2PDataStore()) | |||||
# 2MB, per MAX_PROTOCOL_MESSAGE_LENGTH | |||||
msg_limit = 2 * 1024 * 1024 | |||||
# Account for the 4-byte length prefix | |||||
valid_data_limit = msg_limit - 5 | |||||
# | |||||
# 0. | |||||
# | |||||
# Send as large a message as is valid, ensure we aren't disconnected but | |||||
# also can't exhaust resources. | |||||
# | |||||
msg_at_size = msg_unrecognized("b" * valid_data_limit) | |||||
assert len(msg_at_size.serialize()) == msg_limit | |||||
with node.assert_memory_usage_stable(perc_increase_allowed=0.03): | |||||
self.log.info( | |||||
"Sending a bunch of large, junk messages to test " | |||||
"memory exhaustion. May take a bit...") | |||||
# Run a bunch of times to test for memory exhaustion. | |||||
for _ in range(80): | |||||
node.p2p.send_message(msg_at_size) | |||||
# Check that, even though the node is being hammered by nonsense from one | |||||
# connection, it can still service other peers in a timely way. | |||||
for _ in range(20): | |||||
conn2.sync_with_ping(timeout=2) | |||||
# Peer 1, despite serving up a bunch of nonsense, should still be | |||||
# connected. | |||||
self.log.info("Waiting for node to drop junk messages.") | |||||
node.p2p.sync_with_ping(timeout=30) | |||||
assert node.p2p.is_connected | |||||
# | |||||
# 1. | |||||
# | |||||
# Send an oversized message, ensure we're disconnected. | |||||
# | |||||
msg_over_size = msg_unrecognized("b" * (valid_data_limit + 1)) | |||||
assert len(msg_over_size.serialize()) == (msg_limit + 1) | |||||
with node.assert_debug_log(["Oversized header detected"]): | |||||
# An unknown message type (or *any* message type) over | |||||
# MAX_PROTOCOL_MESSAGE_LENGTH should result in a disconnect. | |||||
node.p2p.send_message(msg_over_size) | |||||
node.p2p.wait_for_disconnect(timeout=4) | |||||
node.disconnect_p2ps() | |||||
conn = node.add_p2p_connection(P2PDataStore()) | |||||
conn.wait_for_verack() | |||||
# | |||||
# 2. | |||||
# | |||||
# Send messages with an incorrect data size in the header. | |||||
# | |||||
actual_size = 100 | |||||
msg = msg_unrecognized("b" * actual_size) | |||||
# TODO: handle larger-than cases. I haven't been able to pin down what | |||||
# behavior to expect. | |||||
for wrong_size in (2, 77, 78, 79): | |||||
self.log.info( | |||||
"Sending a message with incorrect size of {}".format(wrong_size)) | |||||
# Unmodified message should submit okay. | |||||
node.p2p.send_and_ping(msg) | |||||
# A message lying about its data size results in a disconnect when the incorrect | |||||
# data size is less than the actual size. | |||||
# | |||||
# TODO: why does behavior change at 78 bytes? | |||||
# | |||||
node.p2p.send_raw_message( | |||||
self._tweak_msg_data_size( | |||||
msg, wrong_size)) | |||||
# For some reason unknown to me, we sometimes have to push additional data to the | |||||
# peer in order for it to realize a disconnect. | |||||
try: | |||||
node.p2p.send_message(messages.msg_ping(nonce=123123)) | |||||
except IOError: | |||||
pass | |||||
node.p2p.wait_for_disconnect(timeout=10) | |||||
node.disconnect_p2ps() | |||||
node.add_p2p_connection(P2PDataStore()) | |||||
# | |||||
# 3. | |||||
# | |||||
# Send a message with a too-long command name. | |||||
# | |||||
node.p2p.send_message(msg_nametoolong("foobar")) | |||||
node.p2p.wait_for_disconnect(timeout=4) | |||||
# Node is still up. | |||||
conn = node.add_p2p_connection(P2PDataStore()) | |||||
conn.sync_with_ping() | |||||
def _tweak_msg_data_size(self, message, wrong_size): | |||||
""" | |||||
Return a raw message based on another message but with an incorrect data size in | |||||
the message header. | |||||
""" | |||||
raw_msg = self.node.p2p.build_message(message) | |||||
bad_size_bytes = struct.pack("<I", wrong_size) | |||||
num_header_bytes_before_size = 4 + 12 | |||||
# Replace the correct data size in the message with an incorrect one. | |||||
raw_msg_with_wrong_size = ( | |||||
raw_msg[:num_header_bytes_before_size] + | |||||
bad_size_bytes + | |||||
raw_msg[(num_header_bytes_before_size + len(bad_size_bytes)):] | |||||
) | |||||
assert len(raw_msg) == len(raw_msg_with_wrong_size) | |||||
return raw_msg_with_wrong_size | |||||
if __name__ == '__main__': | |||||
InvalidMessagesTest().main() |