diff --git a/test/functional/p2p_invalid_messages.py b/test/functional/p2p_invalid_messages.py index 001a641bf..73e54d17d 100755 --- a/test/functional/p2p_invalid_messages.py +++ b/test/functional/p2p_invalid_messages.py @@ -1,180 +1,178 @@ #!/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 + 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=320) + 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(" {}".format(self.binary, sys.argv[0])) self.coverage_dir = coverage_dir if extra_conf is not None: append_config(datadir, extra_conf) # Most callers will just need to add extra args to the default list # below. # For those callers that need more flexibility, they can access the # default args using the provided facilities. # Note that common args are set in the config file (see # initialize_datadir) self.extra_args = extra_args self.default_args = [ "-datadir=" + self.datadir, "-logtimemicros", "-debug", "-debugexclude=libevent", "-debugexclude=leveldb", "-uacomment=" + self.name, "-noprinttoconsole", ] if emulator is not None: if not os.path.isfile(emulator): raise FileNotFoundError( "Emulator '{}' could not be found.".format(emulator)) self.emulator = emulator if use_cli and not os.path.isfile(bitcoin_cli): raise FileNotFoundError( "Binary '{}' could not be found.\nTry setting it manually:\n\tBITCOINCLI= {}".format(bitcoin_cli, sys.argv[0])) self.cli = TestNodeCLI(bitcoin_cli, self.datadir, self.emulator) self.use_cli = use_cli self.running = False self.process = None self.rpc_connected = False self.rpc = None self.url = None self.relay_fee_cache = None self.log = logging.getLogger('TestFramework.node{}'.format(i)) # Whether to kill the node when this object goes away self.cleanup_on_exit = True self.p2ps = [] AddressKeyPair = collections.namedtuple( 'AddressKeyPair', ['address', 'key']) PRIV_KEYS = [ # address , privkey AddressKeyPair( 'mjTkW3DjgyZck4KbiRusZsqTgaYTxdSz6z', 'cVpF924EspNh8KjYsfhgY96mmxvT6DgdWiTYMtMjuM74hJaU5psW'), AddressKeyPair( 'msX6jQXvxiNhx3Q62PKeLPrhrqZQdSimTg', 'cUxsWyKyZ9MAQTaAhUQWJmBbSvHMwSmuv59KgxQV7oZQU3PXN3KE'), AddressKeyPair( 'mnonCMyH9TmAsSj3M59DsbH8H63U3RKoFP', 'cTrh7dkEAeJd6b3MRX9bZK8eRmNqVCMH3LSUkE3dSFDyzjU38QxK'), AddressKeyPair( 'mqJupas8Dt2uestQDvV2NH3RU8uZh2dqQR', 'cVuKKa7gbehEQvVq717hYcbE9Dqmq7KEBKqWgWrYBa2CKKrhtRim'), AddressKeyPair( 'msYac7Rvd5ywm6pEmkjyxhbCDKqWsVeYws', 'cQDCBuKcjanpXDpCqacNSjYfxeQj8G6CAtH1Dsk3cXyqLNC4RPuh'), AddressKeyPair( 'n2rnuUnwLgXqf9kk2kjvVm8R5BZK1yxQBi', 'cQakmfPSLSqKHyMFGwAqKHgWUiofJCagVGhiB4KCainaeCSxeyYq'), AddressKeyPair( 'myzuPxRwsf3vvGzEuzPfK9Nf2RfwauwYe6', 'cQMpDLJwA8DBe9NcQbdoSb1BhmFxVjWD5gRyrLZCtpuF9Zi3a9RK'), AddressKeyPair( 'mumwTaMtbxEPUswmLBBN3vM9oGRtGBrys8', 'cSXmRKXVcoouhNNVpcNKFfxsTsToY5pvB9DVsFksF1ENunTzRKsy'), AddressKeyPair( 'mpV7aGShMkJCZgbW7F6iZgrvuPHjZjH9qg', 'cSoXt6tm3pqy43UMabY6eUTmR3eSUYFtB2iNQDGgb3VUnRsQys2k'), AddressKeyPair( 'mq4fBNdckGtvY2mijd9am7DRsbRB4KjUkf', 'cN55daf1HotwBAgAKWVgDcoppmUNDtQSfb7XLutTLeAgVc3u8hik'), AddressKeyPair( 'mpFAHDjX7KregM3rVotdXzQmkbwtbQEnZ6', 'cT7qK7g1wkYEMvKowd2ZrX1E5f6JQ7TM246UfqbCiyF7kZhorpX3'), AddressKeyPair( 'mzRe8QZMfGi58KyWCse2exxEFry2sfF2Y7', 'cPiRWE8KMjTRxH1MWkPerhfoHFn5iHPWVK5aPqjW8NxmdwenFinJ'), ] def get_deterministic_priv_key(self): """Return a deterministic priv key in base58, that only depends on the node's index""" assert len(self.PRIV_KEYS) == MAX_NODES return self.PRIV_KEYS[self.index] - def get_mem_rss(self): - """Get the memory usage (RSS) per `ps`. - - If process is stopped or `ps` is unavailable, return None. - """ - if not (self.running and self.process): - self.log.warning( - "Couldn't get memory usage; process isn't running.") - return None - - try: - return int(subprocess.check_output( - "ps h -o rss {}".format(self.process.pid), - shell=True, stderr=subprocess.DEVNULL).strip()) - - # Catching `Exception` broadly to avoid failing on platforms where ps - # isn't installed or doesn't work as expected, e.g. OpenBSD. - # - # We could later use something like `psutils` to work across platforms. - except Exception: - self.log.exception("Unable to get memory usage") - return None - def _node_msg(self, msg: str) -> str: """Return a modified msg that identifies this node by its index as a debugging aid.""" return "[node {}] {}".format(self.index, msg) def _raise_assertion_error(self, msg: str): """Raise an AssertionError with msg modified to identify this node.""" raise AssertionError(self._node_msg(msg)) def __del__(self): # Ensure that we don't leave any bitcoind processes lying around after # the test ends if self.process and self.cleanup_on_exit: # Should only happen on test failure # Avoid using logger, as that may have already been shutdown when # this destructor is called. print(self._node_msg("Cleaning up leftover process")) self.process.kill() def __getattr__(self, name): """Dispatches any unrecognised messages to the RPC connection or a CLI instance.""" if self.use_cli: return getattr(self.cli, name) else: assert self.rpc is not None, self._node_msg( "Error: RPC not initialized") assert self.rpc_connected, self._node_msg( "Error: No RPC connection") return getattr(self.rpc, name) def clear_default_args(self): self.default_args.clear() def extend_default_args(self, args): self.default_args.extend(args) def remove_default_args(self, args): for rm_arg in args: # Remove all occurrences of rm_arg in self.default_args: # - if the arg is a flag (-flag), then the names must match # - if the arg is a value (-key=value) then the name must starts # with "-key=" (the '"' char is to avoid removing "-key_suffix" # arg is "-key" is the argument to remove). self.default_args = [def_arg for def_arg in self.default_args if rm_arg != def_arg and not def_arg.startswith(rm_arg + '=')] def start(self, extra_args=None, *, stdout=None, stderr=None, **kwargs): """Start the node.""" if extra_args is None: extra_args = self.extra_args # Add a new stdout and stderr file each time bitcoind is started if stderr is None: stderr = tempfile.NamedTemporaryFile( dir=self.stderr_dir, delete=False) if stdout is None: stdout = tempfile.NamedTemporaryFile( dir=self.stdout_dir, delete=False) self.stderr = stderr self.stdout = stdout # Delete any existing cookie file -- if such a file exists (eg due to # unclean shutdown), it will get overwritten anyway by bitcoind, and # potentially interfere with our attempt to authenticate delete_cookie_file(self.datadir, self.chain) # add environment variable LIBC_FATAL_STDERR_=1 so that libc errors are # written to stderr and not the terminal subp_env = dict(os.environ, LIBC_FATAL_STDERR_="1") p_args = [self.binary] + self.default_args + extra_args if self.emulator is not None: p_args = [self.emulator] + p_args self.process = subprocess.Popen( p_args, env=subp_env, stdout=stdout, stderr=stderr, **kwargs) self.running = True self.log.debug("bitcoind started, waiting for RPC to come up") def wait_for_rpc_connection(self): """Sets up an RPC connection to the bitcoind process. Returns False if unable to connect.""" # Poll at a rate of four times per second poll_per_s = 4 for _ in range(poll_per_s * self.rpc_timeout): if self.process.poll() is not None: raise FailedToStartError(self._node_msg( 'bitcoind exited with status {} during initialization'.format(self.process.returncode))) try: rpc = get_rpc_proxy( rpc_url( self.datadir, self.chain, self.host, self.rpc_port), self.index, timeout=self.rpc_timeout, coveragedir=self.coverage_dir) rpc.getblockcount() # If the call to getblockcount() succeeds then the RPC # connection is up self.log.debug("RPC successfully started") if self.use_cli: return self.rpc = rpc self.rpc_connected = True self.url = self.rpc.url return except IOError as e: if e.errno != errno.ECONNREFUSED: # Port not yet open? raise # unknown IO error except JSONRPCException as e: # Initialization phase # -28 RPC in warmup # -342 Service unavailable, RPC server started but is shutting down due to error if e.error['code'] != -28 and e.error['code'] != -342: raise # unknown JSON RPC exception except ValueError as e: # cookie file not found and no rpcuser or rpcassword. bitcoind still starting if "No RPC credentials" not in str(e): raise time.sleep(1.0 / poll_per_s) self._raise_assertion_error("Unable to connect to bitcoind") def generate(self, nblocks, maxtries=1000000): self.log.debug( "TestNode.generate() dispatches `generate` call to `generatetoaddress`") return self.generatetoaddress( nblocks=nblocks, address=self.get_deterministic_priv_key().address, maxtries=maxtries) def get_wallet_rpc(self, wallet_name): if self.use_cli: return self.cli("-rpcwallet={}".format(wallet_name)) else: assert self.rpc is not None, self._node_msg( "Error: RPC not initialized") assert self.rpc_connected, self._node_msg( "Error: RPC not connected") wallet_path = "wallet/{}".format(urllib.parse.quote(wallet_name)) return self.rpc / wallet_path def stop_node(self, expected_stderr='', wait=0): """Stop the node.""" if not self.running: return self.log.debug("Stopping node") try: self.stop(wait=wait) except http.client.CannotSendRequest: self.log.exception("Unable to stop node.") # Check that stderr is as expected self.stderr.seek(0) stderr = self.stderr.read().decode('utf-8').strip() if stderr != expected_stderr: raise AssertionError( "Unexpected stderr {} != {}".format(stderr, expected_stderr)) self.stdout.close() self.stderr.close() del self.p2ps[:] def is_node_stopped(self): """Checks whether the node has stopped. Returns True if the node has stopped. False otherwise. This method is responsible for freeing resources (self.process).""" if not self.running: return True return_code = self.process.poll() if return_code is None: return False # process has stopped. Assert that it didn't return an error code. assert return_code == 0, self._node_msg( "Node returned non-zero exit code ({}) when stopping".format(return_code)) self.running = False self.process = None self.rpc_connected = False self.rpc = None self.log.debug("Node stopped") return True def wait_until_stopped(self, timeout=BITCOIND_PROC_WAIT_TIMEOUT): wait_until(self.is_node_stopped, timeout=timeout) @contextlib.contextmanager def assert_debug_log(self, expected_msgs, unexpected_msgs=None, timeout=2): """Assert that some debug messages are present within some timeout. Unexpected debug messages may be optionally provided to fail a test if they appear before expected messages. Note: expected_msgs must always be non-empty even if the goal is to check for unexpected_msgs. This provides a bounded scenario such that "we expect to reach some target resulting in expected_msgs without seeing unexpected_msgs. Otherwise, we are testing that something never happens, which is fundamentally not robust test logic. """ if not expected_msgs: raise AssertionError("Expected debug messages is empty") if unexpected_msgs is None: unexpected_msgs = [] time_end = time.time() + timeout debug_log = os.path.join(self.datadir, self.chain, 'debug.log') with open(debug_log, encoding='utf-8') as dl: dl.seek(0, 2) prev_size = dl.tell() yield while True: found = True with open(debug_log, encoding='utf-8') as dl: dl.seek(prev_size) log = dl.read() print_log = " - " + "\n - ".join(log.splitlines()) for unexpected_msg in unexpected_msgs: if re.search(re.escape(unexpected_msg), log, flags=re.MULTILINE): self._raise_assertion_error( 'Unexpected message "{}" partially matches log:\n\n{}\n\n'.format( unexpected_msg, print_log)) for expected_msg in expected_msgs: if re.search(re.escape(expected_msg), log, flags=re.MULTILINE) is None: found = False if found: return if time.time() >= time_end: break time.sleep(0.05) self._raise_assertion_error( 'Expected messages "{}" does not partially match log:\n\n{}\n\n'.format( str(expected_msgs), print_log)) - @contextlib.contextmanager - def assert_memory_usage_stable(self, perc_increase_allowed=0.03): - """Context manager that allows the user to assert that a node's memory usage (RSS) - hasn't increased beyond some threshold percentage. - """ - before_memory_usage = self.get_mem_rss() - - yield - - after_memory_usage = self.get_mem_rss() - - if not (before_memory_usage and after_memory_usage): - self.log.warning( - "Unable to detect memory usage (RSS) - skipping memory check.") - return - - perc_increase_memory_usage = 1 - \ - (float(before_memory_usage) / after_memory_usage) - - if perc_increase_memory_usage > perc_increase_allowed: - self._raise_assertion_error( - "Memory usage increased over threshold of {:.3f}% from {} to {} ({:.3f}%)".format( - perc_increase_allowed * 100, before_memory_usage, after_memory_usage, - perc_increase_memory_usage * 100)) - def assert_start_raises_init_error( self, extra_args=None, expected_msg=None, match=ErrorMatch.FULL_TEXT, *args, **kwargs): """Attempt to start the node and expect it to raise an error. extra_args: extra arguments to pass through to bitcoind expected_msg: regex that stderr should match when bitcoind fails Will throw if bitcoind starts without an error. Will throw if an expected_msg is provided and it does not match bitcoind's stdout.""" with tempfile.NamedTemporaryFile(dir=self.stderr_dir, delete=False) as log_stderr, \ tempfile.NamedTemporaryFile(dir=self.stdout_dir, delete=False) as log_stdout: try: self.start(extra_args, stdout=log_stdout, stderr=log_stderr, *args, **kwargs) self.wait_for_rpc_connection() self.stop_node() self.wait_until_stopped() except FailedToStartError as e: self.log.debug('bitcoind failed to start: {}'.format(e)) self.running = False self.process = None # Check stderr for expected message if expected_msg is not None: log_stderr.seek(0) stderr = log_stderr.read().decode('utf-8').strip() if match == ErrorMatch.PARTIAL_REGEX: if re.search(expected_msg, stderr, flags=re.MULTILINE) is None: self._raise_assertion_error( 'Expected message "{}" does not partially match stderr:\n"{}"'.format(expected_msg, stderr)) elif match == ErrorMatch.FULL_REGEX: if re.fullmatch(expected_msg, stderr) is None: self._raise_assertion_error( 'Expected message "{}" does not fully match stderr:\n"{}"'.format(expected_msg, stderr)) elif match == ErrorMatch.FULL_TEXT: if expected_msg != stderr: self._raise_assertion_error( 'Expected message "{}" does not fully match stderr:\n"{}"'.format(expected_msg, stderr)) else: if expected_msg is None: assert_msg = "bitcoind should have exited with an error" else: assert_msg = "bitcoind should have exited with expected error " + expected_msg self._raise_assertion_error(assert_msg) def relay_fee(self, cached=True): if not self.relay_fee_cache or not cached: self.relay_fee_cache = self.getnetworkinfo()["relayfee"] return self.relay_fee_cache def calculate_fee(self, tx): """ Estimate the necessary fees (in sats) for an unsigned CTransaction assuming: - the current relayfee on node - all inputs are compressed-key p2pkh, and will be signed ecdsa or schnorr - all inputs currently unsigned (empty scriptSig) """ billable_size_estimate = tx.billable_size() # Add some padding for signatures / public keys # 107 = length of PUSH(longest_sig = 72 bytes), PUSH(pubkey = 33 bytes) billable_size_estimate += len(tx.vin) * 107 # relay_fee gives a value in BCH per kB. return int(self.relay_fee() / 1000 * billable_size_estimate * COIN) def calculate_fee_from_txid(self, txid): ctx = FromHex(CTransaction(), self.getrawtransaction(txid)) return self.calculate_fee(ctx) def add_p2p_connection(self, p2p_conn, *, wait_for_verack=True, **kwargs): """Add a p2p connection to the node. This method adds the p2p connection to the self.p2ps list and also returns the connection to the caller.""" if 'dstport' not in kwargs: kwargs['dstport'] = p2p_port(self.index) if 'dstaddr' not in kwargs: kwargs['dstaddr'] = '127.0.0.1' p2p_conn.peer_connect(**kwargs)() self.p2ps.append(p2p_conn) if wait_for_verack: p2p_conn.wait_for_verack() return p2p_conn @property def p2p(self): """Return the first p2p connection Convenience property - most tests only use a single p2p connection to each node, so this saves having to write node.p2ps[0] many times.""" assert self.p2ps, self._node_msg("No p2p connection") return self.p2ps[0] def disconnect_p2ps(self): """Close all p2p connections to the node.""" for p in self.p2ps: p.peer_disconnect() del self.p2ps[:] class TestNodeCLIAttr: def __init__(self, cli, command): self.cli = cli self.command = command def __call__(self, *args, **kwargs): return self.cli.send_cli(self.command, *args, **kwargs) def get_request(self, *args, **kwargs): return lambda: self(*args, **kwargs) def arg_to_cli(arg): if isinstance(arg, bool): return str(arg).lower() elif isinstance(arg, dict) or isinstance(arg, list): return json.dumps(arg) else: return str(arg) class TestNodeCLI(): """Interface to bitcoin-cli for an individual node""" def __init__(self, binary, datadir, emulator=None): self.options = [] self.binary = binary self.datadir = datadir self.input = None self.log = logging.getLogger('TestFramework.bitcoincli') self.emulator = emulator def __call__(self, *options, input=None): # TestNodeCLI is callable with bitcoin-cli command-line options cli = TestNodeCLI(self.binary, self.datadir, self.emulator) cli.options = [str(o) for o in options] cli.input = input return cli def __getattr__(self, command): return TestNodeCLIAttr(self, command) def batch(self, requests): results = [] for request in requests: try: results.append(dict(result=request())) except JSONRPCException as e: results.append(dict(error=e)) return results def send_cli(self, command=None, *args, **kwargs): """Run bitcoin-cli command. Deserializes returned string as python object.""" pos_args = [arg_to_cli(arg) for arg in args] named_args = [str(key) + "=" + arg_to_cli(value) for (key, value) in kwargs.items()] assert not ( pos_args and named_args), "Cannot use positional arguments and named arguments in the same bitcoin-cli call" p_args = [self.binary, "-datadir=" + self.datadir] + self.options if named_args: p_args += ["-named"] if command is not None: p_args += [command] p_args += pos_args + named_args if self.emulator is not None: p_args = [self.emulator] + p_args self.log.debug("Running bitcoin-cli command: {}".format(command)) process = subprocess.Popen(p_args, stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE, universal_newlines=True) cli_stdout, cli_stderr = process.communicate(input=self.input) returncode = process.poll() if returncode: match = re.match( r'error code: ([-0-9]+)\nerror message:\n(.*)', cli_stderr) if match: code, message = match.groups() raise JSONRPCException(dict(code=int(code), message=message)) # Ignore cli_stdout, raise with cli_stderr raise subprocess.CalledProcessError( returncode, self.binary, output=cli_stderr) try: return json.loads(cli_stdout, parse_float=decimal.Decimal) except json.JSONDecodeError: return cli_stdout.rstrip("\n")