Ben Gruver | 4efe940 | 2013-04-02 21:18:41 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2013 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 com.android.server.firewall; |
| 18 | |
| 19 | import android.content.ComponentName; |
| 20 | import android.content.Intent; |
Ben Gruver | 4efe940 | 2013-04-02 21:18:41 -0700 | [diff] [blame] | 21 | import android.net.Uri; |
| 22 | import android.os.PatternMatcher; |
| 23 | import org.xmlpull.v1.XmlPullParser; |
| 24 | import org.xmlpull.v1.XmlPullParserException; |
| 25 | |
| 26 | import java.io.IOException; |
| 27 | import java.util.regex.Pattern; |
| 28 | |
| 29 | abstract class StringFilter implements Filter { |
| 30 | private static final String ATTR_EQUALS = "equals"; |
| 31 | private static final String ATTR_STARTS_WITH = "startsWith"; |
| 32 | private static final String ATTR_CONTAINS = "contains"; |
| 33 | private static final String ATTR_PATTERN = "pattern"; |
| 34 | private static final String ATTR_REGEX = "regex"; |
| 35 | private static final String ATTR_IS_NULL = "isNull"; |
| 36 | |
| 37 | private final ValueProvider mValueProvider; |
| 38 | |
| 39 | private StringFilter(ValueProvider valueProvider) { |
| 40 | this.mValueProvider = valueProvider; |
| 41 | } |
| 42 | |
| 43 | /** |
| 44 | * Constructs a new StringFilter based on the string filter attribute on the current |
| 45 | * element, and the given StringValueMatcher. |
| 46 | * |
| 47 | * The current node should contain exactly 1 string filter attribute. E.g. equals, |
| 48 | * contains, etc. Otherwise, an XmlPullParserException will be thrown. |
| 49 | * |
| 50 | * @param parser An XmlPullParser object positioned at an element that should |
| 51 | * contain a string filter attribute |
| 52 | * @return This StringFilter object |
| 53 | */ |
| 54 | public static StringFilter readFromXml(ValueProvider valueProvider, XmlPullParser parser) |
| 55 | throws IOException, XmlPullParserException { |
| 56 | StringFilter filter = null; |
| 57 | |
| 58 | for (int i=0; i<parser.getAttributeCount(); i++) { |
| 59 | StringFilter newFilter = getFilter(valueProvider, parser, i); |
| 60 | if (newFilter != null) { |
| 61 | if (filter != null) { |
| 62 | throw new XmlPullParserException("Multiple string filter attributes found"); |
| 63 | } |
| 64 | filter = newFilter; |
| 65 | } |
| 66 | } |
| 67 | |
| 68 | if (filter == null) { |
| 69 | // if there are no string filter attributes, we default to isNull="false" so that an |
| 70 | // empty filter is equivalent to an existence check |
| 71 | filter = new IsNullFilter(valueProvider, false); |
| 72 | } |
| 73 | |
| 74 | return filter; |
| 75 | } |
| 76 | |
| 77 | private static StringFilter getFilter(ValueProvider valueProvider, XmlPullParser parser, |
| 78 | int attributeIndex) { |
| 79 | String attributeName = parser.getAttributeName(attributeIndex); |
| 80 | |
| 81 | switch (attributeName.charAt(0)) { |
| 82 | case 'e': |
| 83 | if (!attributeName.equals(ATTR_EQUALS)) { |
| 84 | return null; |
| 85 | } |
| 86 | return new EqualsFilter(valueProvider, parser.getAttributeValue(attributeIndex)); |
| 87 | case 'i': |
| 88 | if (!attributeName.equals(ATTR_IS_NULL)) { |
| 89 | return null; |
| 90 | } |
| 91 | return new IsNullFilter(valueProvider, parser.getAttributeValue(attributeIndex)); |
| 92 | case 's': |
| 93 | if (!attributeName.equals(ATTR_STARTS_WITH)) { |
| 94 | return null; |
| 95 | } |
| 96 | return new StartsWithFilter(valueProvider, |
| 97 | parser.getAttributeValue(attributeIndex)); |
| 98 | case 'c': |
| 99 | if (!attributeName.equals(ATTR_CONTAINS)) { |
| 100 | return null; |
| 101 | } |
| 102 | return new ContainsFilter(valueProvider, parser.getAttributeValue(attributeIndex)); |
| 103 | case 'p': |
| 104 | if (!attributeName.equals(ATTR_PATTERN)) { |
| 105 | return null; |
| 106 | } |
| 107 | return new PatternStringFilter(valueProvider, |
| 108 | parser.getAttributeValue(attributeIndex)); |
| 109 | case 'r': |
| 110 | if (!attributeName.equals(ATTR_REGEX)) { |
| 111 | return null; |
| 112 | } |
| 113 | return new RegexFilter(valueProvider, parser.getAttributeValue(attributeIndex)); |
| 114 | } |
| 115 | return null; |
| 116 | } |
| 117 | |
| 118 | protected abstract boolean matchesValue(String value); |
| 119 | |
| 120 | @Override |
Ben Gruver | f5323fe | 2013-07-31 15:09:51 -0700 | [diff] [blame] | 121 | public boolean matches(IntentFirewall ifw, ComponentName resolvedComponent, Intent intent, |
Ben Gruver | 49660c7 | 2013-08-06 19:54:08 -0700 | [diff] [blame] | 122 | int callerUid, int callerPid, String resolvedType, int receivingUid) { |
| 123 | String value = mValueProvider.getValue(resolvedComponent, intent, resolvedType); |
Ben Gruver | 4efe940 | 2013-04-02 21:18:41 -0700 | [diff] [blame] | 124 | return matchesValue(value); |
| 125 | } |
| 126 | |
| 127 | private static abstract class ValueProvider extends FilterFactory { |
| 128 | protected ValueProvider(String tag) { |
| 129 | super(tag); |
| 130 | } |
| 131 | |
| 132 | public Filter newFilter(XmlPullParser parser) |
| 133 | throws IOException, XmlPullParserException { |
| 134 | return StringFilter.readFromXml(this, parser); |
| 135 | } |
| 136 | |
Ben Gruver | f5323fe | 2013-07-31 15:09:51 -0700 | [diff] [blame] | 137 | public abstract String getValue(ComponentName resolvedComponent, Intent intent, |
Ben Gruver | 49660c7 | 2013-08-06 19:54:08 -0700 | [diff] [blame] | 138 | String resolvedType); |
Ben Gruver | 4efe940 | 2013-04-02 21:18:41 -0700 | [diff] [blame] | 139 | } |
| 140 | |
| 141 | private static class EqualsFilter extends StringFilter { |
| 142 | private final String mFilterValue; |
| 143 | |
| 144 | public EqualsFilter(ValueProvider valueProvider, String attrValue) { |
| 145 | super(valueProvider); |
| 146 | mFilterValue = attrValue; |
| 147 | } |
| 148 | |
| 149 | @Override |
| 150 | public boolean matchesValue(String value) { |
| 151 | return value != null && value.equals(mFilterValue); |
| 152 | } |
| 153 | } |
| 154 | |
| 155 | private static class ContainsFilter extends StringFilter { |
| 156 | private final String mFilterValue; |
| 157 | |
| 158 | public ContainsFilter(ValueProvider valueProvider, String attrValue) { |
| 159 | super(valueProvider); |
| 160 | mFilterValue = attrValue; |
| 161 | } |
| 162 | |
| 163 | @Override |
| 164 | public boolean matchesValue(String value) { |
| 165 | return value != null && value.contains(mFilterValue); |
| 166 | } |
| 167 | } |
| 168 | |
| 169 | private static class StartsWithFilter extends StringFilter { |
| 170 | private final String mFilterValue; |
| 171 | |
| 172 | public StartsWithFilter(ValueProvider valueProvider, String attrValue) { |
| 173 | super(valueProvider); |
| 174 | mFilterValue = attrValue; |
| 175 | } |
| 176 | |
| 177 | @Override |
| 178 | public boolean matchesValue(String value) { |
| 179 | return value != null && value.startsWith(mFilterValue); |
| 180 | } |
| 181 | } |
| 182 | |
| 183 | private static class PatternStringFilter extends StringFilter { |
| 184 | private final PatternMatcher mPattern; |
| 185 | |
| 186 | public PatternStringFilter(ValueProvider valueProvider, String attrValue) { |
| 187 | super(valueProvider); |
| 188 | mPattern = new PatternMatcher(attrValue, PatternMatcher.PATTERN_SIMPLE_GLOB); |
| 189 | } |
| 190 | |
| 191 | @Override |
| 192 | public boolean matchesValue(String value) { |
| 193 | return value != null && mPattern.match(value); |
| 194 | } |
| 195 | } |
| 196 | |
| 197 | private static class RegexFilter extends StringFilter { |
| 198 | private final Pattern mPattern; |
| 199 | |
| 200 | public RegexFilter(ValueProvider valueProvider, String attrValue) { |
| 201 | super(valueProvider); |
| 202 | this.mPattern = Pattern.compile(attrValue); |
| 203 | } |
| 204 | |
| 205 | @Override |
| 206 | public boolean matchesValue(String value) { |
| 207 | return value != null && mPattern.matcher(value).matches(); |
| 208 | } |
| 209 | } |
| 210 | |
| 211 | private static class IsNullFilter extends StringFilter { |
| 212 | private final boolean mIsNull; |
| 213 | |
| 214 | public IsNullFilter(ValueProvider valueProvider, String attrValue) { |
| 215 | super(valueProvider); |
| 216 | mIsNull = Boolean.parseBoolean(attrValue); |
| 217 | } |
| 218 | |
| 219 | public IsNullFilter(ValueProvider valueProvider, boolean isNull) { |
| 220 | super(valueProvider); |
| 221 | mIsNull = isNull; |
| 222 | } |
| 223 | |
| 224 | @Override |
| 225 | public boolean matchesValue(String value) { |
| 226 | return (value == null) == mIsNull; |
| 227 | } |
| 228 | } |
| 229 | |
| 230 | public static final ValueProvider COMPONENT = new ValueProvider("component") { |
| 231 | @Override |
Ben Gruver | 49660c7 | 2013-08-06 19:54:08 -0700 | [diff] [blame] | 232 | public String getValue(ComponentName resolvedComponent, Intent intent, |
| 233 | String resolvedType) { |
Ben Gruver | f5323fe | 2013-07-31 15:09:51 -0700 | [diff] [blame] | 234 | if (resolvedComponent != null) { |
| 235 | return resolvedComponent.flattenToString(); |
Ben Gruver | 4efe940 | 2013-04-02 21:18:41 -0700 | [diff] [blame] | 236 | } |
| 237 | return null; |
| 238 | } |
| 239 | }; |
| 240 | |
| 241 | public static final ValueProvider COMPONENT_NAME = new ValueProvider("component-name") { |
| 242 | @Override |
Ben Gruver | 49660c7 | 2013-08-06 19:54:08 -0700 | [diff] [blame] | 243 | public String getValue(ComponentName resolvedComponent, Intent intent, |
| 244 | String resolvedType) { |
Ben Gruver | f5323fe | 2013-07-31 15:09:51 -0700 | [diff] [blame] | 245 | if (resolvedComponent != null) { |
| 246 | return resolvedComponent.getClassName(); |
Ben Gruver | 4efe940 | 2013-04-02 21:18:41 -0700 | [diff] [blame] | 247 | } |
| 248 | return null; |
| 249 | } |
| 250 | }; |
| 251 | |
| 252 | public static final ValueProvider COMPONENT_PACKAGE = new ValueProvider("component-package") { |
| 253 | @Override |
Ben Gruver | 49660c7 | 2013-08-06 19:54:08 -0700 | [diff] [blame] | 254 | public String getValue(ComponentName resolvedComponent, Intent intent, |
| 255 | String resolvedType) { |
Ben Gruver | f5323fe | 2013-07-31 15:09:51 -0700 | [diff] [blame] | 256 | if (resolvedComponent != null) { |
| 257 | return resolvedComponent.getPackageName(); |
Ben Gruver | 4efe940 | 2013-04-02 21:18:41 -0700 | [diff] [blame] | 258 | } |
| 259 | return null; |
| 260 | } |
| 261 | }; |
| 262 | |
Ben Gruver | 4efe940 | 2013-04-02 21:18:41 -0700 | [diff] [blame] | 263 | public static final FilterFactory ACTION = new ValueProvider("action") { |
| 264 | @Override |
Ben Gruver | 49660c7 | 2013-08-06 19:54:08 -0700 | [diff] [blame] | 265 | public String getValue(ComponentName resolvedComponent, Intent intent, |
| 266 | String resolvedType) { |
Ben Gruver | 4efe940 | 2013-04-02 21:18:41 -0700 | [diff] [blame] | 267 | return intent.getAction(); |
| 268 | } |
| 269 | }; |
| 270 | |
| 271 | public static final ValueProvider DATA = new ValueProvider("data") { |
| 272 | @Override |
Ben Gruver | 49660c7 | 2013-08-06 19:54:08 -0700 | [diff] [blame] | 273 | public String getValue(ComponentName resolvedComponent, Intent intent, |
| 274 | String resolvedType) { |
Ben Gruver | 4efe940 | 2013-04-02 21:18:41 -0700 | [diff] [blame] | 275 | Uri data = intent.getData(); |
| 276 | if (data != null) { |
| 277 | return data.toString(); |
| 278 | } |
| 279 | return null; |
| 280 | } |
| 281 | }; |
| 282 | |
| 283 | public static final ValueProvider MIME_TYPE = new ValueProvider("mime-type") { |
| 284 | @Override |
Ben Gruver | 49660c7 | 2013-08-06 19:54:08 -0700 | [diff] [blame] | 285 | public String getValue(ComponentName resolvedComponent, Intent intent, |
| 286 | String resolvedType) { |
Ben Gruver | 4efe940 | 2013-04-02 21:18:41 -0700 | [diff] [blame] | 287 | return resolvedType; |
| 288 | } |
| 289 | }; |
| 290 | |
| 291 | public static final ValueProvider SCHEME = new ValueProvider("scheme") { |
| 292 | @Override |
Ben Gruver | 49660c7 | 2013-08-06 19:54:08 -0700 | [diff] [blame] | 293 | public String getValue(ComponentName resolvedComponent, Intent intent, |
| 294 | String resolvedType) { |
Ben Gruver | 4efe940 | 2013-04-02 21:18:41 -0700 | [diff] [blame] | 295 | Uri data = intent.getData(); |
| 296 | if (data != null) { |
| 297 | return data.getScheme(); |
| 298 | } |
| 299 | return null; |
| 300 | } |
| 301 | }; |
| 302 | |
| 303 | public static final ValueProvider SSP = new ValueProvider("scheme-specific-part") { |
| 304 | @Override |
Ben Gruver | 49660c7 | 2013-08-06 19:54:08 -0700 | [diff] [blame] | 305 | public String getValue(ComponentName resolvedComponent, Intent intent, |
| 306 | String resolvedType) { |
Ben Gruver | 4efe940 | 2013-04-02 21:18:41 -0700 | [diff] [blame] | 307 | Uri data = intent.getData(); |
| 308 | if (data != null) { |
| 309 | return data.getSchemeSpecificPart(); |
| 310 | } |
| 311 | return null; |
| 312 | } |
| 313 | }; |
| 314 | |
| 315 | public static final ValueProvider HOST = new ValueProvider("host") { |
| 316 | @Override |
Ben Gruver | 49660c7 | 2013-08-06 19:54:08 -0700 | [diff] [blame] | 317 | public String getValue(ComponentName resolvedComponent, Intent intent, |
| 318 | String resolvedType) { |
Ben Gruver | 4efe940 | 2013-04-02 21:18:41 -0700 | [diff] [blame] | 319 | Uri data = intent.getData(); |
| 320 | if (data != null) { |
| 321 | return data.getHost(); |
| 322 | } |
| 323 | return null; |
| 324 | } |
| 325 | }; |
| 326 | |
| 327 | public static final ValueProvider PATH = new ValueProvider("path") { |
| 328 | @Override |
Ben Gruver | 49660c7 | 2013-08-06 19:54:08 -0700 | [diff] [blame] | 329 | public String getValue(ComponentName resolvedComponent, Intent intent, |
| 330 | String resolvedType) { |
Ben Gruver | 4efe940 | 2013-04-02 21:18:41 -0700 | [diff] [blame] | 331 | Uri data = intent.getData(); |
| 332 | if (data != null) { |
| 333 | return data.getPath(); |
| 334 | } |
| 335 | return null; |
| 336 | } |
| 337 | }; |
| 338 | } |