FrameBridge 0.3.1 community source release

source/expanded/framebridge_expanded/uninstall.py

@@ -0,0 +1,146 @@
+"""Stop only this package's managed user services before Debian removal."""
+from pathlib import Path
+import hashlib
+import os
+import pwd
+import re
+import shlex
+import stat
+import subprocess
+import sys
+
+MODULE_ROOT = "/usr/lib/framebridge-expanded/expanded"
+UNIT_NAME = re.compile(r"framebridge-autostart-[0-9a-f]{16}\.service\Z")
+
+
+def managed_unit(path, uid):
+    """Inspect a bounded owned regular file; never execute user configuration."""
+    if not UNIT_NAME.fullmatch(path.name):
+        return False
+    try:
+        fd = os.open(path, os.O_RDONLY | os.O_NOFOLLOW | os.O_NONBLOCK)
+        try:
+            info = os.fstat(fd)
+            if not stat.S_ISREG(info.st_mode) or info.st_uid != uid or info.st_size > 16384:
+                return False
+            raw = os.read(fd, 16385)
+        finally:
+            os.close(fd)
+        lines = raw.decode("utf-8").splitlines()
+        if not lines or lines[0] != "# FrameBridge managed autostart v1":
+            return False
+        if lines.count('Environment="PYTHONPATH=' + MODULE_ROOT + '"') != 1:
+            return False
+        starts = [line[10:] for line in lines if line.startswith("ExecStart=")]
+        if len(starts) != 1:
+            return False
+        args = shlex.split(starts[0])
+        if len(args) != 7 or args[0] not in {"/usr/bin/python3", "/usr/bin/python3.13"}:
+            return False
+        if args[1:6] != ["-B", "-m", "framebridge_expanded.autostart", "_run", "--state"]:
+            return False
+        state = args[6].replace("%%", "%").replace("$$", "$")
+        if not state.startswith("/") or any(ord(c) < 32 for c in state):
+            return False
+        expected = "framebridge-autostart-" + hashlib.sha256(state.encode()).hexdigest()[:16] + ".service"
+        return path.name == expected
+    except (OSError, UnicodeError, ValueError):
+        return False
+
+
+def cleanup_user(home=None, *, run=None, bus_available=None):
+    run = run or subprocess.run
+    home = Path(home) if home is not None else Path.home()
+    uid = os.getuid()
+    directory = home / ".config/systemd/user"
+    if not directory.is_dir():
+        return 0
+    units = sorted(p.name for p in directory.glob("framebridge-autostart-*.service") if managed_unit(p, uid))
+    if not units:
+        return 0
+    runtime = Path("/run/user") / str(uid)
+    if bus_available is None:
+        try:
+            bus_available = stat.S_ISSOCK((runtime / "bus").stat().st_mode)
+        except OSError:
+            bus_available = False
+    env = {"HOME": str(home), "PATH": "/usr/bin:/bin", "LANG": "C.UTF-8", "XDG_CONFIG_HOME": str(home / ".config"), "XDG_RUNTIME_DIR": str(runtime), "DBUS_SESSION_BUS_ADDRESS": "unix:path=" + str(runtime / "bus")}
+    failure = False
+    if bus_available:
+        try:
+            result = run(["/usr/bin/systemctl", "--user", "stop", *units], env=env, capture_output=True, timeout=35)
+            if result.returncode:
+                current = run(["/usr/bin/systemctl", "--user", "show", *units, "--property=ActiveState", "--value"], env=env, capture_output=True, timeout=5)
+                values = current.stdout.decode().split() if isinstance(current.stdout, bytes) else current.stdout.split()
+                failure = current.returncode != 0 or len(values) != len(units) or any(value not in {"inactive", "failed"} for value in values)
+        except (OSError, subprocess.TimeoutExpired):
+            failure = True
+        try:
+            result = run(["/usr/bin/systemctl", "--user", "--no-reload", "disable", *units], env=env, capture_output=True, timeout=10)
+            failure = result.returncode != 0 or failure
+        except (OSError, subprocess.TimeoutExpired):
+            failure = True
+    # Remove only enablement symlinks targeting these exact managed files.
+    # This also works offline: systemctl can delegate file operations to a live
+    # user manager with a different environment, and no bus exists at all for
+    # an offline owner. Never delete profile data, ciphertext, or unit files.
+    for group in directory.iterdir():
+        if not group.name.endswith((".wants", ".requires")) or group.is_symlink() or not group.is_dir():
+            continue
+        for name in units:
+            link = group / name
+            if link.is_symlink():
+                try:
+                    if link.resolve() == (directory / name).resolve():
+                        link.unlink()
+                except OSError:
+                    failure = True
+    if bus_available:
+        try:
+            run(["/usr/bin/systemctl", "--user", "daemon-reload"], env=env, capture_output=True, timeout=3)
+        except (OSError, subprocess.TimeoutExpired):
+            pass  # Units are stopped/disabled; an owner may have just logged out.
+    if failure:
+        raise RuntimeError("A managed FrameBridge service could not be stopped or disabled.")
+    return len(units)
+
+
+def cleanup_all_users(*, run=None, accounts=None):
+    if os.getuid() != 0:
+        raise RuntimeError("Package service cleanup requires the normal package manager's root context.")
+    run = run or subprocess.run
+    accounts = pwd.getpwall() if accounts is None else accounts
+    seen = set()
+    failed = False
+    for account in accounts:
+        identity = (account.pw_uid, account.pw_dir)
+        if identity in seen or account.pw_uid == 65534 or not account.pw_dir.startswith("/") or account.pw_dir in {"/", "/nonexistent", "/dev/null"}:
+            continue
+        seen.add(identity)
+        command = ["/usr/sbin/runuser", "-u", account.pw_name, "--", "/usr/bin/env", "-i", "HOME=" + account.pw_dir, "USER=" + account.pw_name, "LOGNAME=" + account.pw_name, "PATH=/usr/bin:/bin", "LANG=C.UTF-8", "/usr/bin/python3", "-I", "-S", str(Path(__file__).resolve()), "--user"]
+        try:
+            result = run(command, capture_output=True, timeout=55)
+            failed = result.returncode != 0 or failed
+        except (OSError, subprocess.TimeoutExpired):
+            failed = True
+    if failed:
+        raise RuntimeError("Some FrameBridge services could not be stopped; package removal was paused.")
+
+
+def main(argv=None):
+    args = list(sys.argv[1:] if argv is None else argv)
+    try:
+        if args == ["--all-users"]:
+            cleanup_all_users()
+        elif args == ["--user"]:
+            cleanup_user()
+        else:
+            return 2
+        return 0
+    except (OSError, RuntimeError, subprocess.TimeoutExpired):
+        print("FrameBridge service cleanup did not complete. Package data was retained.", file=sys.stderr)
+        return 1
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())