#!/bin/sh
# Copyright 2018 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

# Run apk-cache-cleaner with minijail0.
# 656360 is an Android system UID/GID

set -e

# See src/platform2/arc/setup/arc_setup.cc for more info about these values.
SYSTEM_UID="656360"
SYSTEM_GID="656360"

APK_CACHE_PATH=/mnt/stateful_partition/unencrypted/apkcache
if [ ! -d "${APK_CACHE_PATH}" ]; then
  # If the APK cache directory does not exist, there's nothing to clean.
  exit 0
fi

# Bind cache directory as writable. Add /var directory to follow /etc/localtime.
# Enter new pid and cgroup namespaces. Setting no new privileges.
# Restrict caps to 0. Entering new mount namespace, new UTS namespace,
# new IPC namespace and new network namespace.
exec minijail0 --profile minimalistic-mountns \
  -k 'none,/mnt,tmpfs,MS_NODEV|MS_NOEXEC|MS_NOSUID,mode=755,size=64k' \
  -b "${APK_CACHE_PATH},,1" \
  -k 'none,/var,tmpfs,MS_NODEV|MS_NOEXEC|MS_NOSUID,mode=755,size=64k' \
  -b /var/lib/timezone \
  -p -N -n -c 0 -v -r --uts -l -e \
  -S /usr/share/policy/apk-cache-cleaner-seccomp.policy \
  -u "${SYSTEM_UID}" -g "${SYSTEM_GID}" -- /usr/sbin/apk-cache-cleaner