config/chroot_local-includes/usr/lib/python3/dist-packages/tailslib/userenv.py

   1 #!/usr/bin/python3
   2 import sys
   3 from functools import lru_cache
   4 import os
   5 from pathlib import Path
   6 import pwd
   7 from typing import Mapping
   8
   9 ENV_VARS_TO_DUMP = [
  10     "DBUS_SESSION_BUS_ADDRESS",
  11     "DISPLAY",
  12     "LANG",
  13     "WAYLAND_DISPLAY",
  14     "XAUTHORITY",
  15     "XDG_RUNTIME_DIR",
  16     "XDG_CURRENT_DESKTOP",
  17 ]
  18
  19 ALLOWED_ENV_VARS = ENV_VARS_TO_DUMP + [
  20     "DESKTOP_STARTUP_ID",
  21     "INHERIT_FD",
  22 ]
  23
  24 USER_ENV_FILE_TEMPLATE = "/run/user/{uid}/user-env"
  25
  26
  27 def user_env_file(uid):
  28     return USER_ENV_FILE_TEMPLATE.format(uid=uid)
  29
  30
  31 def allowed_env(env: Mapping) -> dict:
  32     """
  33     >>> allowed_env({"PATH": "/home/", "LANG": "en"})
  34     {'LANG': 'en'}
  35     """
  36     return {key: value for key, value in env.items() if key in ALLOWED_ENV_VARS}
  37
  38
  39 def read_allowed_env_from_file(envfile: str) -> dict:
  40     env = dict()
  41
  42     for line in Path(envfile).read_text().split('\0'):
  43         if not line:
  44             continue
  45
  46         try:
  47             key, value = line.split("=", 1)
  48         except Exception as e:
  49             print(f"Invalid environment variable: '{line}'", file=sys.stderr)
  50             raise e
  51
  52         env[key] = value
  53
  54     return allowed_env(env)
  55
  56
  57 @lru_cache(maxsize=1)
  58 def read_user_env(user=None) -> dict:
  59     if user is None:
  60         uid = os.geteuid()
  61     else:
  62         uid = pwd.getpwnam(user).pw_uid
  63
  64     return read_allowed_env_from_file(user_env_file(uid))
  65
  66
  67 def user_env_vars(user=None) -> list:
  68     return [f"{key}={value}" for key, value in read_user_env(user).items()]