mitmproxy/netlib/utils.py
2016-10-17 18:03:07 +13:00

98 lines
2.4 KiB
Python

import os.path
import re
import importlib
import inspect
def setbit(byte, offset, value):
"""
Set a bit in a byte to 1 if value is truthy, 0 if not.
"""
if value:
return byte | (1 << offset)
else:
return byte & ~(1 << offset)
def getbit(byte, offset):
mask = 1 << offset
return bool(byte & mask)
class BiDi:
"""
A wee utility class for keeping bi-directional mappings, like field
constants in protocols. Names are attributes on the object, dict-like
access maps values to names:
CONST = BiDi(a=1, b=2)
assert CONST.a == 1
assert CONST.get_name(1) == "a"
"""
def __init__(self, **kwargs):
self.names = kwargs
self.values = {}
for k, v in kwargs.items():
self.values[v] = k
if len(self.names) != len(self.values):
raise ValueError("Duplicate values not allowed.")
def __getattr__(self, k):
if k in self.names:
return self.names[k]
raise AttributeError("No such attribute: %s", k)
def get_name(self, n, default=None):
return self.values.get(n, default)
class Data:
def __init__(self, name):
m = importlib.import_module(name)
dirname = os.path.dirname(inspect.getsourcefile(m))
self.dirname = os.path.abspath(dirname)
def push(self, subpath):
"""
Change the data object to a path relative to the module.
"""
self.dirname = os.path.join(self.dirname, subpath)
return self
def path(self, path):
"""
Returns a path to the package data housed at 'path' under this
module.Path can be a path to a file, or to a directory.
This function will raise ValueError if the path does not exist.
"""
fullpath = os.path.join(self.dirname, path)
if not os.path.exists(fullpath):
raise ValueError("dataPath: %s does not exist." % fullpath)
return fullpath
_label_valid = re.compile(b"(?!-)[A-Z\d-]{1,63}(?<!-)$", re.IGNORECASE)
def is_valid_host(host: bytes) -> bool:
"""
Checks if a hostname is valid.
"""
try:
host.decode("idna")
except ValueError:
return False
if len(host) > 255:
return False
if host and host[-1:] == b".":
host = host[:-1]
return all(_label_valid.match(x) for x in host.split(b"."))
def is_valid_port(port):
return 0 <= port <= 65535