dcashman | 6456007 | 2013-11-06 11:38:25 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2014 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | package android.security.cts; |
| 18 | |
| 19 | import android.util.Xml; |
| 20 | |
| 21 | import com.google.common.collect.HashMultimap; |
| 22 | import com.google.common.collect.Multimap; |
| 23 | import org.xmlpull.v1.XmlPullParser; |
| 24 | import org.xmlpull.v1.XmlPullParserException; |
| 25 | |
| 26 | import java.io.InputStream; |
| 27 | import java.io.IOException; |
| 28 | import java.util.ArrayList; |
| 29 | import java.util.List; |
| 30 | import java.util.HashMap; |
| 31 | |
| 32 | |
| 33 | /** |
| 34 | * A class for generating representations of SELinux avc rules parsed from an xml file. |
| 35 | */ |
| 36 | public class SELinuxPolicyRule { |
| 37 | public final List<String> source_types; |
| 38 | public final List<String> target_types; |
| 39 | public final Multimap<String, String> obj_classes; |
| 40 | public final String name; |
| 41 | public final String type; |
| 42 | |
| 43 | private SELinuxPolicyRule(List<String> source_types, List<String> target_types, |
| 44 | Multimap<String, String> obj_classes, String name, String type) { |
| 45 | this.source_types = source_types; |
| 46 | this.target_types = target_types; |
| 47 | this.obj_classes = obj_classes; |
| 48 | this.name = name; |
| 49 | this.type = type; |
| 50 | } |
| 51 | |
| 52 | public static SELinuxPolicyRule readRule(XmlPullParser xpp) throws IOException, XmlPullParserException { |
| 53 | List<String> source_types = new ArrayList<String>(); |
| 54 | List<String> target_types = new ArrayList<String>(); |
| 55 | Multimap<String, String> obj_classes = HashMultimap.create(); |
| 56 | xpp.require(XmlPullParser.START_TAG, null, "avc_rule"); |
| 57 | String ruleName = xpp.getAttributeValue(null, "name"); |
| 58 | String ruleType = xpp.getAttributeValue(null, "type"); |
| 59 | while (xpp.next() != XmlPullParser.END_TAG) { |
| 60 | if (xpp.getEventType() != XmlPullParser.START_TAG) { |
| 61 | continue; |
| 62 | } |
| 63 | String name = xpp.getName(); |
| 64 | if (name.equals("type")) { |
| 65 | if (xpp.getAttributeValue(null, "type").equals("source")) { |
| 66 | source_types.add(readType(xpp)); |
| 67 | } else if (xpp.getAttributeValue(null, "type").equals("target")) { |
| 68 | target_types.add(readType(xpp)); |
| 69 | } else { |
| 70 | skip(xpp); |
| 71 | } |
| 72 | } else if (name.equals("obj_class")) { |
| 73 | String obj_name = xpp.getAttributeValue(null, "name"); |
| 74 | List<String> perms = readObjClass(xpp); |
| 75 | obj_classes.putAll(obj_name, perms); |
| 76 | } else { |
| 77 | skip(xpp); |
| 78 | } |
| 79 | } |
| 80 | return new SELinuxPolicyRule(source_types, target_types, obj_classes, ruleName, ruleType); |
| 81 | } |
| 82 | |
| 83 | public static List<SELinuxPolicyRule> readRulesFile(InputStream in) throws IOException, XmlPullParserException { |
| 84 | List<SELinuxPolicyRule> rules = new ArrayList<SELinuxPolicyRule>(); |
| 85 | XmlPullParser xpp = Xml.newPullParser(); |
| 86 | xpp.setInput(in, null); |
| 87 | xpp.nextTag(); |
| 88 | xpp.require(XmlPullParser.START_TAG, null, "SELinux_AVC_Rules"); |
| 89 | |
| 90 | /* read rules */ |
| 91 | while (xpp.next() != XmlPullParser.END_TAG) { |
| 92 | if (xpp.getEventType() != XmlPullParser.START_TAG) { |
| 93 | continue; |
| 94 | } |
| 95 | String name = xpp.getName(); |
| 96 | if (name.equals("avc_rule")) { |
| 97 | SELinuxPolicyRule r = readRule(xpp); |
| 98 | rules.add(r); |
| 99 | } else { |
| 100 | skip(xpp); |
| 101 | } |
| 102 | } |
| 103 | return rules; |
| 104 | } |
| 105 | |
| 106 | private static List<String> readObjClass(XmlPullParser xpp) throws IOException, XmlPullParserException { |
| 107 | List<String> perms = new ArrayList<String>(); |
| 108 | xpp.require(XmlPullParser.START_TAG, null, "obj_class"); |
| 109 | while (xpp.next() != XmlPullParser.END_TAG) { |
| 110 | if (xpp.getEventType() != XmlPullParser.START_TAG) { |
| 111 | continue; |
| 112 | } |
| 113 | String name = xpp.getName(); |
| 114 | if (name.equals("permission")) { |
| 115 | perms.add(readPermission(xpp)); |
| 116 | } else { |
| 117 | skip(xpp); |
| 118 | } |
| 119 | } |
| 120 | return perms; |
| 121 | } |
| 122 | |
| 123 | private static String readType(XmlPullParser xpp) throws IOException, XmlPullParserException { |
| 124 | xpp.require(XmlPullParser.START_TAG, null, "type"); |
| 125 | String type = readText(xpp); |
| 126 | xpp.require(XmlPullParser.END_TAG, null, "type"); |
| 127 | return type; |
| 128 | } |
| 129 | |
| 130 | private static String readPermission(XmlPullParser xpp) throws IOException, XmlPullParserException { |
| 131 | xpp.require(XmlPullParser.START_TAG, null, "permission"); |
| 132 | String permission = readText(xpp); |
| 133 | xpp.require(XmlPullParser.END_TAG, null, "permission"); |
| 134 | return permission; |
| 135 | } |
| 136 | |
| 137 | private static String readText(XmlPullParser xpp) throws IOException, XmlPullParserException { |
| 138 | String result = ""; |
| 139 | if (xpp.next() == XmlPullParser.TEXT) { |
| 140 | result = xpp.getText(); |
| 141 | xpp.nextTag(); |
| 142 | } |
| 143 | return result; |
| 144 | } |
| 145 | |
| 146 | public static void skip(XmlPullParser xpp) throws XmlPullParserException, IOException { |
| 147 | if (xpp.getEventType() != XmlPullParser.START_TAG) { |
| 148 | throw new IllegalStateException(); |
| 149 | } |
| 150 | int depth = 1; |
| 151 | while (depth != 0) { |
| 152 | switch (xpp.next()) { |
| 153 | case XmlPullParser.END_TAG: |
| 154 | depth--; |
| 155 | break; |
| 156 | case XmlPullParser.START_TAG: |
| 157 | depth++; |
| 158 | break; |
| 159 | } |
| 160 | } |
| 161 | } |
| 162 | } |