Current File : //lib/python3/dist-packages/mitmproxy/command.py
"""
This module manages and invokes typed commands.
"""
import functools
import inspect
import sys
import textwrap
import types
import typing
import mitmproxy.types
from mitmproxy import exceptions, command_lexer
from mitmproxy.command_lexer import unquote
def verify_arg_signature(f: typing.Callable, args: typing.Iterable[typing.Any], kwargs: dict) -> None:
sig = inspect.signature(f)
try:
sig.bind(*args, **kwargs)
except TypeError as v:
raise exceptions.CommandError("command argument mismatch: %s" % v.args[0])
def typename(t: type) -> str:
"""
Translates a type to an explanatory string.
"""
if t == inspect._empty: # type: ignore
raise exceptions.CommandError("missing type annotation")
to = mitmproxy.types.CommandTypes.get(t, None)
if not to:
raise exceptions.CommandError("unsupported type: %s" % getattr(t, "__name__", t))
return to.display
def _empty_as_none(x: typing.Any) -> typing.Any:
if x == inspect.Signature.empty:
return None
return x
class CommandParameter(typing.NamedTuple):
name: str
type: typing.Type
kind: inspect._ParameterKind = inspect.Parameter.POSITIONAL_OR_KEYWORD
def __str__(self):
if self.kind is inspect.Parameter.VAR_POSITIONAL:
return f"*{self.name}"
else:
return self.name
class Command:
name: str
manager: "CommandManager"
signature: inspect.Signature
help: typing.Optional[str]
def __init__(self, manager: "CommandManager", name: str, func: typing.Callable) -> None:
self.name = name
self.manager = manager
self.func = func
self.signature = inspect.signature(self.func)
if func.__doc__:
txt = func.__doc__.strip()
self.help = "\n".join(textwrap.wrap(txt))
else:
self.help = None
# This fails with a CommandException if types are invalid
for name, parameter in self.signature.parameters.items():
t = parameter.annotation
if not mitmproxy.types.CommandTypes.get(parameter.annotation, None):
raise exceptions.CommandError(f"Argument {name} has an unknown type ({_empty_as_none(t)}) in {func}.")
if self.return_type and not mitmproxy.types.CommandTypes.get(self.return_type, None):
raise exceptions.CommandError(f"Return type has an unknown type ({self.return_type}) in {func}.")
@property
def return_type(self) -> typing.Optional[typing.Type]:
return _empty_as_none(self.signature.return_annotation)
@property
def parameters(self) -> typing.List[CommandParameter]:
"""Returns a list of CommandParameters."""
ret = []
for name, param in self.signature.parameters.items():
ret.append(CommandParameter(name, param.annotation, param.kind))
return ret
def signature_help(self) -> str:
params = " ".join(str(param) for param in self.parameters)
if self.return_type:
ret = f" -> {typename(self.return_type)}"
else:
ret = ""
return f"{self.name} {params}{ret}"
def prepare_args(self, args: typing.Sequence[str]) -> inspect.BoundArguments:
try:
bound_arguments = self.signature.bind(*args)
except TypeError:
expected = f'Expected: {str(self.signature.parameters)}'
received = f'Received: {str(args)}'
raise exceptions.CommandError(f"Command argument mismatch: \n {expected}\n {received}")
for name, value in bound_arguments.arguments.items():
convert_to = self.signature.parameters[name].annotation
bound_arguments.arguments[name] = parsearg(self.manager, value, convert_to)
bound_arguments.apply_defaults()
return bound_arguments
def call(self, args: typing.Sequence[str]) -> typing.Any:
"""
Call the command with a list of arguments. At this point, all
arguments are strings.
"""
bound_args = self.prepare_args(args)
ret = self.func(*bound_args.args, **bound_args.kwargs)
if ret is None and self.return_type is None:
return
typ = mitmproxy.types.CommandTypes.get(self.return_type)
assert typ
if not typ.is_valid(self.manager, typ, ret):
raise exceptions.CommandError(
f"{self.name} returned unexpected data - expected {typ.display}"
)
return ret
class ParseResult(typing.NamedTuple):
value: str
type: typing.Type
valid: bool
class CommandManager:
commands: typing.Dict[str, Command]
def __init__(self, master):
self.master = master
self.commands = {}
def collect_commands(self, addon):
for i in dir(addon):
if not i.startswith("__"):
o = getattr(addon, i)
try:
# hasattr is not enough, see https://github.com/mitmproxy/mitmproxy/issues/3794
is_command = isinstance(getattr(o, "command_name", None), str)
except Exception:
pass # getattr may raise if o implements __getattr__.
else:
if is_command:
try:
self.add(o.command_name, o)
except exceptions.CommandError as e:
self.master.log.warn(
f"Could not load command {o.command_name}: {e}"
)
def add(self, path: str, func: typing.Callable):
self.commands[path] = Command(self, path, func)
@functools.lru_cache(maxsize=128)
def parse_partial(
self,
cmdstr: str
) -> typing.Tuple[typing.Sequence[ParseResult], typing.Sequence[CommandParameter]]:
"""
Parse a possibly partial command. Return a sequence of ParseResults and a sequence of remainder type help items.
"""
parts: typing.List[str] = command_lexer.expr.parseString(cmdstr, parseAll=True)
parsed: typing.List[ParseResult] = []
next_params: typing.List[CommandParameter] = [
CommandParameter("", mitmproxy.types.Cmd),
CommandParameter("", mitmproxy.types.CmdArgs),
]
expected: typing.Optional[CommandParameter] = None
for part in parts:
if part.isspace():
parsed.append(
ParseResult(
value=part,
type=mitmproxy.types.Space,
valid=True,
)
)
continue
if expected and expected.kind is inspect.Parameter.VAR_POSITIONAL:
assert not next_params
elif next_params:
expected = next_params.pop(0)
else:
expected = CommandParameter("", mitmproxy.types.Unknown)
arg_is_known_command = (
expected.type == mitmproxy.types.Cmd and part in self.commands
)
arg_is_unknown_command = (
expected.type == mitmproxy.types.Cmd and part not in self.commands
)
command_args_following = (
next_params and next_params[0].type == mitmproxy.types.CmdArgs
)
if arg_is_known_command and command_args_following:
next_params = self.commands[part].parameters + next_params[1:]
if arg_is_unknown_command and command_args_following:
next_params.pop(0)
to = mitmproxy.types.CommandTypes.get(expected.type, None)
valid = False
if to:
try:
to.parse(self, expected.type, part)
except exceptions.TypeError:
valid = False
else:
valid = True
parsed.append(
ParseResult(
value=part,
type=expected.type,
valid=valid,
)
)
return parsed, next_params
def call(self, command_name: str, *args: typing.Sequence[typing.Any]) -> typing.Any:
"""
Call a command with native arguments. May raise CommandError.
"""
if command_name not in self.commands:
raise exceptions.CommandError("Unknown command: %s" % command_name)
return self.commands[command_name].func(*args)
def call_strings(self, command_name: str, args: typing.Sequence[str]) -> typing.Any:
"""
Call a command using a list of string arguments. May raise CommandError.
"""
if command_name not in self.commands:
raise exceptions.CommandError("Unknown command: %s" % command_name)
return self.commands[command_name].call(args)
def execute(self, cmdstr: str) -> typing.Any:
"""
Execute a command string. May raise CommandError.
"""
parts, _ = self.parse_partial(cmdstr)
if not parts:
raise exceptions.CommandError(f"Invalid command: {cmdstr!r}")
command_name, *args = [
unquote(part.value)
for part in parts
if part.type != mitmproxy.types.Space
]
return self.call_strings(command_name, args)
def dump(self, out=sys.stdout) -> None:
cmds = list(self.commands.values())
cmds.sort(key=lambda x: x.signature_help())
for c in cmds:
for hl in (c.help or "").splitlines():
print("# " + hl, file=out)
print(c.signature_help(), file=out)
print(file=out)
def parsearg(manager: CommandManager, spec: str, argtype: type) -> typing.Any:
"""
Convert a string to a argument to the appropriate type.
"""
t = mitmproxy.types.CommandTypes.get(argtype, None)
if not t:
raise exceptions.CommandError(f"Unsupported argument type: {argtype}")
try:
return t.parse(manager, argtype, spec)
except exceptions.TypeError as e:
raise exceptions.CommandError(str(e)) from e
def command(name: typing.Optional[str] = None):
def decorator(function):
@functools.wraps(function)
def wrapper(*args, **kwargs):
verify_arg_signature(function, args, kwargs)
return function(*args, **kwargs)
wrapper.__dict__["command_name"] = name or function.__name__.replace("_", ".")
return wrapper
return decorator
def argument(name, type):
"""
Set the type of a command argument at runtime. This is useful for more
specific types such as mitmproxy.types.Choice, which we cannot annotate
directly as mypy does not like that.
"""
def decorator(f: types.FunctionType) -> types.FunctionType:
assert name in f.__annotations__
f.__annotations__[name] = type
return f
return decorator
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