idasit/dbus_fast/_private/address.py

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2024-12-14 14:55:37 +01:00
import os
import re
from typing import Dict, List, Optional, Tuple
from urllib.parse import unquote
from ..constants import BusType
from ..errors import InvalidAddressError
invalid_address_chars_re = re.compile(r"[^-0-9A-Za-z_/.%]")
str_ = str
def parse_address(address_str: str_) -> List[Tuple[str, Dict[str, str]]]:
"""Parse a dbus address string into a list of addresses."""
addresses: List[Tuple[str, Dict[str, str]]] = []
for address in address_str.split(";"):
if not address:
continue
if address.find(":") == -1:
raise InvalidAddressError("address did not contain a transport")
transport, opt_string = address.split(":", 1)
options: Dict[str, str] = {}
for kv in opt_string.split(","):
if not kv:
continue
if kv.find("=") == -1:
raise InvalidAddressError("address option did not contain a value")
k, v = kv.split("=", 1)
if invalid_address_chars_re.search(v):
raise InvalidAddressError("address contains invalid characters")
# XXX the actual unquote rules are simpler than this
options[k] = unquote(v)
addresses.append((transport, options))
if not addresses:
raise InvalidAddressError(
f'address string contained no addresses: "{address_str}"'
)
return addresses
def get_system_bus_address() -> str:
"""Get the system bus address from the environment or return the default."""
return (
os.environ.get("DBUS_SYSTEM_BUS_ADDRESS")
or "unix:path=/var/run/dbus/system_bus_socket"
)
display_re = re.compile(r".*:([0-9]+)\.?.*")
remove_quotes_re = re.compile(r"""^['"]?(.*?)['"]?$""")
def get_session_bus_address() -> str:
"""Get the session bus address from the environment or return the default."""
dbus_session_bus_address = os.environ.get("DBUS_SESSION_BUS_ADDRESS")
if dbus_session_bus_address:
return dbus_session_bus_address
home = os.environ["HOME"]
if "DISPLAY" not in os.environ:
raise InvalidAddressError(
"DBUS_SESSION_BUS_ADDRESS not set and could not get DISPLAY environment variable to get bus address"
)
display = os.environ["DISPLAY"]
try:
display = display_re.search(display).group(1)
except Exception:
raise InvalidAddressError(
f"DBUS_SESSION_BUS_ADDRESS not set and could not parse DISPLAY environment variable to get bus address: {display}"
)
# XXX: this will block but they're very small files and fs operations
# should be fairly reliable. fix this by passing in an async func to read
# the file for each io backend.
machine_id = None
with open("/var/lib/dbus/machine-id") as f:
machine_id = f.read().rstrip()
dbus_info_file_name = f"{home}/.dbus/session-bus/{machine_id}-{display}"
dbus_info: Optional[str] = None
try:
with open(dbus_info_file_name) as f:
dbus_info = f.read().rstrip()
except Exception:
raise InvalidAddressError(
f"could not open dbus info file: {dbus_info_file_name}"
)
for line in dbus_info.split("\n"):
if line.strip().startswith("DBUS_SESSION_BUS_ADDRESS="):
_, addr = line.split("=", 1)
if not addr:
raise InvalidAddressError(
f"DBUS_SESSION_BUS_ADDRESS variable not set correctly in dbus info file: {dbus_info_file_name}"
)
addr = remove_quotes_re.search(addr).group(1)
return addr
raise InvalidAddressError("could not find dbus session bus address")
def get_bus_address(bus_type: BusType) -> str:
"""Get the address of the bus specified by the bus type."""
if bus_type == BusType.SESSION:
return get_session_bus_address()
if bus_type == BusType.SYSTEM:
return get_system_bus_address()
raise Exception(f"got unknown bus type: {bus_type}")