service/java/com/android/permission/access/permission/UidPermissionPersistence.kt

/*
 * Copyright (C) 2022 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.permission.access.permission

import android.content.pm.PermissionInfo
import android.util.Log
import com.android.modules.utils.BinaryXmlPullParser
import com.android.modules.utils.BinaryXmlSerializer
import com.android.permission.access.SystemState
import com.android.permission.access.collection.* // ktlint-disable no-wildcard-imports
import com.android.permission.access.data.Permission
import com.android.permission.access.util.attribute
import com.android.permission.access.util.attributeInt
import com.android.permission.access.util.attributeIntHex
import com.android.permission.access.util.attributeIntHexWithDefault
import com.android.permission.access.util.attributeInterned
import com.android.permission.access.util.forEachTag
import com.android.permission.access.util.getAttributeIntHexOrDefault
import com.android.permission.access.util.getAttributeIntHexOrThrow
import com.android.permission.access.util.getAttributeIntOrThrow
import com.android.permission.access.util.getAttributeValue
import com.android.permission.access.util.getAttributeValueOrThrow
import com.android.permission.access.util.tag
import com.android.permission.access.util.tagName

class UidPermissionPersistence {
    fun BinaryXmlPullParser.parseSystemState(systemState: SystemState) {
        when (tagName) {
            TAG_PERMISSION_TREES -> parsePermissions(systemState.permissionTrees)
            TAG_PERMISSIONS -> parsePermissions(systemState.permissions)
            else -> {}
        }
    }

    private fun BinaryXmlPullParser.parsePermissions(permissions: IndexedMap<String, Permission>) {
        forEachTag {
            when (val tagName = tagName) {
                TAG_PERMISSION -> parsePermission(permissions)
                else -> Log.w(LOG_TAG, "Ignoring unknown tag $tagName when parsing permissions")
            }
        }
    }

    private fun BinaryXmlPullParser.parsePermission(permissions: IndexedMap<String, Permission>) {
        val name = getAttributeValueOrThrow(ATTR_NAME).intern()
        @Suppress("DEPRECATION")
        val permissionInfo = PermissionInfo().apply {
            this.name = name
            packageName = getAttributeValueOrThrow(ATTR_PACKAGE_NAME).intern()
            protectionLevel = getAttributeIntHexOrThrow(ATTR_PROTECTION_LEVEL)
        }
        val type = getAttributeIntOrThrow(ATTR_TYPE)
        when (type) {
            Permission.TYPE_MANIFEST -> {}
            Permission.TYPE_CONFIG -> {
                Log.w(LOG_TAG, "Ignoring unexpected config permission $name")
                return
            }
            Permission.TYPE_DYNAMIC -> {
                permissionInfo.apply {
                    icon = getAttributeIntHexOrDefault(ATTR_ICON, 0)
                    nonLocalizedLabel = getAttributeValue(ATTR_LABEL)
                }
            }
            else -> {
                Log.w(LOG_TAG, "Ignoring permission $name with unknown type $type")
                return
            }
        }
        val permission = Permission(permissionInfo, false, type, 0)
        permissions[name] = permission
    }

    fun BinaryXmlSerializer.serializeSystemState(systemState: SystemState) {
        serializePermissions(TAG_PERMISSION_TREES, systemState.permissionTrees)
        serializePermissions(TAG_PERMISSIONS, systemState.permissions)
    }

    private fun BinaryXmlSerializer.serializePermissions(
        tagName: String,
        permissions: IndexedMap<String, Permission>
    ) {
        tag(tagName) {
            permissions.forEachValueIndexed { _, it -> serializePermission(it) }
        }
    }

    private fun BinaryXmlSerializer.serializePermission(permission: Permission) {
        val type = permission.type
        when (type) {
            Permission.TYPE_MANIFEST, Permission.TYPE_DYNAMIC -> {}
            Permission.TYPE_CONFIG -> return
            else -> {
                Log.w(LOG_TAG, "Skipping serializing permission $name with unknown type $type")
                return
            }
        }
        tag(TAG_PERMISSION) {
            attributeInterned(ATTR_NAME, permission.name)
            attributeInterned(ATTR_PACKAGE_NAME, permission.packageName)
            attributeIntHex(ATTR_PROTECTION_LEVEL, permission.protectionLevel)
            attributeInt(ATTR_TYPE, type)
            if (type == Permission.TYPE_DYNAMIC) {
                val permissionInfo = permission.permissionInfo
                attributeIntHexWithDefault(ATTR_ICON, permissionInfo.icon, 0)
                permissionInfo.nonLocalizedLabel?.toString()?.let { attribute(ATTR_LABEL, it) }
            }
        }
    }

    companion object {
        private val LOG_TAG = UidPermissionPersistence::class.java.simpleName

        private const val TAG_PERMISSION = "permission"
        private const val TAG_PERMISSION_TREES = "permission-trees"
        private const val TAG_PERMISSIONS = "permissions"

        private const val ATTR_ICON = "icon"
        private const val ATTR_LABEL = "label"
        private const val ATTR_NAME = "name"
        private const val ATTR_PACKAGE_NAME = "packageName"
        private const val ATTR_PROTECTION_LEVEL = "protectionLevel"
        private const val ATTR_TYPE = "type"
    }
}