Files
community-plugins/ruh-vpn/backend/service/tun_binary.py
T
0733efd186 Add umedbazarov/ruh-vpn: VPN/proxy manager for sing-box (#304)
* Add umedbazarov/ruh-vpn: VPN/proxy manager for sing-box

New community plugin: bar widget, panel, service and control-center
shortcut for managing SSH, VLESS, VMess, Shadowsocks and SOCKS5
connections through sing-box, with routing presets, custom rules,
system-proxy/TUN modes and a kill switch. The bundled Python backend
serves a loopback control API protected by a per-launch bearer token.

* Address review: sanitize kill-switch ruleset, scope TUN capability, fix mux error path, disclose DNS

- kill switch: only pre-resolved, canonicalized literal IPs enter the nft
  ruleset; domains are resolved first and anything unparseable is dropped,
  so subscription-supplied addresses can no longer inject nft syntax
- TUN: CAP_NET_ADMIN is granted to a plugin-private copy of sing-box in a
  0700 directory instead of the shared system binary; the copy is refreshed
  (clearing the cap) when the system binary changes, and the legacy grant
  on the shared binary is removed in the same polkit prompt
- fix NameError in the mux startup failure path (undefined mux_name) that
  hid the log tail and skipped teardown
- README: disclose plain-UDP DNS endpoints (8.8.8.8 via tunnel, 223.5.5.5
  direct in rules mode) alongside the TUN DoH endpoint

---------

Co-authored-by: Umedjon Bazarov <170195993+UmedjonBA@users.noreply.github.com>
2026-08-09 21:03:02 -04:00

49 lines
1.6 KiB
Python

"""Private copy of the sing-box binary used only for TUN mode.
CAP_NET_ADMIN is granted to a plugin-private copy under DATA_DIR/bin (a 0700
directory) instead of the shared system binary, so the privilege never
extends to other users or to sing-box invocations outside this plugin.
When the system binary changes, the copy is rewritten from scratch; a fresh
file starts with no capabilities, so a stale copy never keeps the grant
across sing-box upgrades.
"""
from __future__ import annotations
import os
import shutil
from pathlib import Path
from backend.paths import DATA_DIR, ensure_private_dir
BIN_DIR = DATA_DIR / "bin"
TUN_BIN = BIN_DIR / "sing-box-tun"
def source_binary(singbox_bin: str) -> str:
# setcap/getcap act on the real file, not a symlink (NixOS wraps binaries
# in store symlinks, and setcap on the link fails).
return os.path.realpath(singbox_bin)
def ensure_copy(singbox_bin: str) -> tuple[str, bool]:
"""Make sure the private copy exists and matches the system binary.
Returns (path to the copy, True if the copy was (re)created). Callers must
treat a recreated copy as having no capabilities.
"""
src = Path(source_binary(singbox_bin))
ensure_private_dir(BIN_DIR)
st_src = src.stat()
if TUN_BIN.exists():
st_dst = TUN_BIN.stat()
if st_dst.st_size == st_src.st_size and st_dst.st_mtime == st_src.st_mtime:
return str(TUN_BIN), False
# copy2 preserves mtime, which the staleness check above relies on
tmp = TUN_BIN.with_name(TUN_BIN.name + ".tmp")
shutil.copy2(src, tmp)
tmp.chmod(0o700)
os.replace(tmp, TUN_BIN)
return str(TUN_BIN), True