/*
* Copyright (C) 2014 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.server;
import static com.android.internal.util.ArrayUtils.appendInt;
import android.app.ActivityManager;
import android.content.ComponentName;
import android.content.pm.FeatureInfo;
import android.content.pm.PackageManager;
import android.content.pm.Signature;
import android.os.Environment;
import android.os.Process;
import android.os.storage.StorageManager;
import android.os.SystemProperties;
import android.util.ArrayMap;
import android.util.ArraySet;
import android.util.Slog;
import android.util.SparseArray;
import android.util.Xml;
import com.android.internal.util.XmlUtils;
import libcore.io.IoUtils;
import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
/**
* Loads global system configuration info.
*/
public class SystemConfig {
static final String TAG = "SystemConfig";
static SystemConfig sInstance;
// permission flag, determines which types of configuration are allowed to be read
private static final int ALLOW_FEATURES = 0x01;
private static final int ALLOW_LIBS = 0x02;
private static final int ALLOW_PERMISSIONS = 0x04;
private static final int ALLOW_APP_CONFIGS = 0x08;
private static final int ALLOW_ALL = ~0;
// Group-ids that are given to all packages as read from etc/permissions/*.xml.
int[] mGlobalGids;
// These are the built-in uid -> permission mappings that were read from the
// system configuration files.
final SparseArray<ArraySet<String>> mSystemPermissions = new SparseArray<>();
// These are the built-in shared libraries that were read from the
// system configuration files. Keys are the library names; strings are the
// paths to the libraries.
final ArrayMap<String, String> mSharedLibraries = new ArrayMap<>();
// These are the features this devices supports that were read from the
// system configuration files.
final ArrayMap<String, FeatureInfo> mAvailableFeatures = new ArrayMap<>();
// These are the features which this device doesn't support; the OEM
// partition uses these to opt-out of features from the system image.
final ArraySet<String> mUnavailableFeatures = new ArraySet<>();
public static final class PermissionEntry {
public final String name;
public int[] gids;
public boolean perUser;
PermissionEntry(String name, boolean perUser) {
this.name = name;
this.perUser = perUser;
}
}
// These are the permission -> gid mappings that were read from the
// system configuration files.
final ArrayMap<String, PermissionEntry> mPermissions = new ArrayMap<>();
// These are the packages that are white-listed to be able to run in the
// background while in power save mode (but not whitelisted from device idle modes),
// as read from the configuration files.
final ArraySet<String> mAllowInPowerSaveExceptIdle = new ArraySet<>();
// These are the packages that are white-listed to be able to run in the
// background while in power save mode, as read from the configuration files.
final ArraySet<String> mAllowInPowerSave = new ArraySet<>();
// These are the packages that are white-listed to be able to run in the
// background while in data-usage save mode, as read from the configuration files.
final ArraySet<String> mAllowInDataUsageSave = new ArraySet<>();
// These are the package names of apps which should be in the 'always'
// URL-handling state upon factory reset.
final ArraySet<String> mLinkedApps = new ArraySet<>();
// These are the packages that are whitelisted to be able to run as system user
final ArraySet<String> mSystemUserWhitelistedApps = new ArraySet<>();
// These are the packages that should not run under system user
final ArraySet<String> mSystemUserBlacklistedApps = new ArraySet<>();
// These are the components that are enabled by default as VR mode listener services.
final ArraySet<ComponentName> mDefaultVrComponents = new ArraySet<>();
// These are the permitted backup transport service components
final ArraySet<ComponentName> mBackupTransportWhitelist = new ArraySet<>();
final ArrayMap<Signature, ArraySet<String>> mSignatureAllowances
= new ArrayMap<Signature, ArraySet<String>>();
// These are the packages of carrier-associated apps which should be disabled until used until
// a SIM is inserted which grants carrier privileges to that carrier app.
final ArrayMap<String, List<String>> mDisabledUntilUsedPreinstalledCarrierAssociatedApps =
new ArrayMap<>();
public static SystemConfig getInstance() {
synchronized (SystemConfig.class) {
if (sInstance == null) {
sInstance = new SystemConfig();
}
return sInstance;
}
}
public int[] getGlobalGids() {
return mGlobalGids;
}
public SparseArray<ArraySet<String>> getSystemPermissions() {
return mSystemPermissions;
}
public ArrayMap<String, String> getSharedLibraries() {
return mSharedLibraries;
}
public ArrayMap<String, FeatureInfo> getAvailableFeatures() {
return mAvailableFeatures;
}
public ArrayMap<String, PermissionEntry> getPermissions() {
return mPermissions;
}
public ArraySet<String> getAllowInPowerSaveExceptIdle() {
return mAllowInPowerSaveExceptIdle;
}
public ArraySet<String> getAllowInPowerSave() {
return mAllowInPowerSave;
}
public ArraySet<String> getAllowInDataUsageSave() {
return mAllowInDataUsageSave;
}
public ArraySet<String> getLinkedApps() {
return mLinkedApps;
}
public ArraySet<String> getSystemUserWhitelistedApps() {
return mSystemUserWhitelistedApps;
}
public ArraySet<String> getSystemUserBlacklistedApps() {
return mSystemUserBlacklistedApps;
}
public ArraySet<ComponentName> getDefaultVrComponents() {
return mDefaultVrComponents;
}
public ArraySet<ComponentName> getBackupTransportWhitelist() {
return mBackupTransportWhitelist;
}
public ArrayMap<Signature, ArraySet<String>> getSignatureAllowances() {
return mSignatureAllowances;
}
public ArrayMap<String, List<String>> getDisabledUntilUsedPreinstalledCarrierAssociatedApps() {
return mDisabledUntilUsedPreinstalledCarrierAssociatedApps;
}
SystemConfig() {
// Read configuration from system
readPermissions(Environment.buildPath(
Environment.getRootDirectory(), "etc", "sysconfig"), ALLOW_ALL);
// Read configuration from the old permissions dir
readPermissions(Environment.buildPath(
Environment.getRootDirectory(), "etc", "permissions"), ALLOW_ALL);
// Allow ODM to customize system configs around libs, features and apps
int odmPermissionFlag = ALLOW_LIBS | ALLOW_FEATURES | ALLOW_APP_CONFIGS;
readPermissions(Environment.buildPath(
Environment.getOdmDirectory(), "etc", "sysconfig"), odmPermissionFlag);
readPermissions(Environment.buildPath(
Environment.getOdmDirectory(), "etc", "permissions"), odmPermissionFlag);
// Only allow OEM to customize features
readPermissions(Environment.buildPath(
Environment.getOemDirectory(), "etc", "sysconfig"), ALLOW_FEATURES);
readPermissions(Environment.buildPath(
Environment.getOemDirectory(), "etc", "permissions"), ALLOW_FEATURES);
//Remove vulkan specific features
if (SystemProperties.getBoolean("persist.graphics.vulkan.disable", false)) {
removeFeature(PackageManager.FEATURE_VULKAN_HARDWARE_LEVEL);
removeFeature(PackageManager.FEATURE_VULKAN_HARDWARE_VERSION);
}
}
void readPermissions(File libraryDir, int permissionFlag) {
// Read permissions from given directory.
if (!libraryDir.exists() || !libraryDir.isDirectory()) {
if (permissionFlag == ALLOW_ALL) {
Slog.w(TAG, "No directory " + libraryDir + ", skipping");
}
return;
}
if (!libraryDir.canRead()) {
Slog.w(TAG, "Directory " + libraryDir + " cannot be read");
return;
}
// Iterate over the files in the directory and scan .xml files
File platformFile = null;
for (File f : libraryDir.listFiles()) {
// We'll read platform.xml last
if (f.getPath().endsWith("etc/permissions/platform.xml")) {
platformFile = f;
continue;
}
if (!f.getPath().endsWith(".xml")) {
Slog.i(TAG, "Non-xml file " + f + " in " + libraryDir + " directory, ignoring");
continue;
}
if (!f.canRead()) {
Slog.w(TAG, "Permissions library file " + f + " cannot be read");
continue;
}
readPermissionsFromXml(f, permissionFlag);
}
// Read platform permissions last so it will take precedence
if (platformFile != null) {
readPermissionsFromXml(platformFile, permissionFlag);
}
}
private void readPermissionsFromXml(File permFile, int permissionFlag) {
FileReader permReader = null;
try {
permReader = new FileReader(permFile);
} catch (FileNotFoundException e) {
Slog.w(TAG, "Couldn't find or open permissions file " + permFile);
return;
}
final boolean lowRam = ActivityManager.isLowRamDeviceStatic();
try {
XmlPullParser parser = Xml.newPullParser();
parser.setInput(permReader);
int type;
while ((type=parser.next()) != parser.START_TAG
&& type != parser.END_DOCUMENT) {
;
}
if (type != parser.START_TAG) {
throw new XmlPullParserException("No start tag found");
}
if (!parser.getName().equals("permissions") && !parser.getName().equals("config")) {
throw new XmlPullParserException("Unexpected start tag in " + permFile
+ ": found " + parser.getName() + ", expected 'permissions' or 'config'");
}
boolean allowAll = permissionFlag == ALLOW_ALL;
boolean allowLibs = (permissionFlag & ALLOW_LIBS) != 0;
boolean allowFeatures = (permissionFlag & ALLOW_FEATURES) != 0;
boolean allowPermissions = (permissionFlag & ALLOW_PERMISSIONS) != 0;
boolean allowAppConfigs = (permissionFlag & ALLOW_APP_CONFIGS) != 0;
while (true) {
XmlUtils.nextElement(parser);
if (parser.getEventType() == XmlPullParser.END_DOCUMENT) {
break;
}
String name = parser.getName();
if ("group".equals(name) && allowAll) {
String gidStr = parser.getAttributeValue(null, "gid");
if (gidStr != null) {
int gid = android.os.Process.getGidForName(gidStr);
mGlobalGids = appendInt(mGlobalGids, gid);
} else {
Slog.w(TAG, "<group> without gid in " + permFile + " at "
+ parser.getPositionDescription());
}
XmlUtils.skipCurrentTag(parser);
continue;
} else if ("allow-permission".equals(name)) {
String perm = parser.getAttributeValue(null, "name");
if (perm == null) {
Slog.w(TAG,
"<allow-permission> without name at "
+ parser.getPositionDescription());
XmlUtils.skipCurrentTag(parser);
continue;
}
String signature = parser.getAttributeValue(null, "signature");
if (signature == null) {
Slog.w(TAG,
"<allow-permission> without signature at "
+ parser.getPositionDescription());
XmlUtils.skipCurrentTag(parser);
continue;
}
Signature sig = null;
try {
sig = new Signature(signature);
} catch (IllegalArgumentException e) {
// sig will be null so we will log it below
}
if (sig != null) {
ArraySet<String> perms = mSignatureAllowances.get(sig);
if (perms == null) {
perms = new ArraySet<String>();
mSignatureAllowances.put(sig, perms);
}
perms.add(perm);
} else {
Slog.w(TAG,
"<allow-permission> with bad signature at "
+ parser.getPositionDescription());
}
XmlUtils.skipCurrentTag(parser);
} else if ("permission".equals(name) && allowPermissions) {
String perm = parser.getAttributeValue(null, "name");
if (perm == null) {
Slog.w(TAG, "<permission> without name in " + permFile + " at "
+ parser.getPositionDescription());
XmlUtils.skipCurrentTag(parser);
continue;
}
perm = perm.intern();
readPermission(parser, perm);
} else if ("assign-permission".equals(name) && allowPermissions) {
String perm = parser.getAttributeValue(null, "name");
if (perm == null) {
Slog.w(TAG, "<assign-permission> without name in " + permFile + " at "
+ parser.getPositionDescription());
XmlUtils.skipCurrentTag(parser);
continue;
}
String uidStr = parser.getAttributeValue(null, "uid");
if (uidStr == null) {
Slog.w(TAG, "<assign-permission> without uid in " + permFile + " at "
+ parser.getPositionDescription());
XmlUtils.skipCurrentTag(parser);
continue;
}
int uid = Process.getUidForName(uidStr);
if (uid < 0) {
Slog.w(TAG, "<assign-permission> with unknown uid \""
+ uidStr + " in " + permFile + " at "
+ parser.getPositionDescription());
XmlUtils.skipCurrentTag(parser);
continue;
}
perm = perm.intern();
ArraySet<String> perms = mSystemPermissions.get(uid);
if (perms == null) {
perms = new ArraySet<String>();
mSystemPermissions.put(uid, perms);
}
perms.add(perm);
XmlUtils.skipCurrentTag(parser);
} else if ("library".equals(name) && allowLibs) {
String lname = parser.getAttributeValue(null, "name");
String lfile = parser.getAttributeValue(null, "file");
if (lname == null) {
Slog.w(TAG, "<library> without name in " + permFile + " at "
+ parser.getPositionDescription());
} else if (lfile == null) {
Slog.w(TAG, "<library> without file in " + permFile + " at "
+ parser.getPositionDescription());
} else {
//Log.i(TAG, "Got library " + lname + " in " + lfile);
mSharedLibraries.put(lname, lfile);
}
XmlUtils.skipCurrentTag(parser);
continue;
} else if ("feature".equals(name) && allowFeatures) {
String fname = parser.getAttributeValue(null, "name");
int fversion = XmlUtils.readIntAttribute(parser, "version", 0);
boolean allowed;
if (!lowRam) {
allowed = true;
} else {
String notLowRam = parser.getAttributeValue(null, "notLowRam");
allowed = !"true".equals(notLowRam);
}
if (fname == null) {
Slog.w(TAG, "<feature> without name in " + permFile + " at "
+ parser.getPositionDescription());
} else if (allowed) {
addFeature(fname, fversion);
}
XmlUtils.skipCurrentTag(parser);
continue;
} else if ("unavailable-feature".equals(name) && allowFeatures) {
String fname = parser.getAttributeValue(null, "name");
if (fname == null) {
Slog.w(TAG, "<unavailable-feature> without name in " + permFile + " at "
+ parser.getPositionDescription());
} else {
mUnavailableFeatures.add(fname);
}
XmlUtils.skipCurrentTag(parser);
continue;
} else if ("allow-in-power-save-except-idle".equals(name) && allowAll) {
String pkgname = parser.getAttributeValue(null, "package");
if (pkgname == null) {
Slog.w(TAG, "<allow-in-power-save-except-idle> without package in "
+ permFile + " at " + parser.getPositionDescription());
} else {
mAllowInPowerSaveExceptIdle.add(pkgname);
}
XmlUtils.skipCurrentTag(parser);
continue;
} else if ("allow-in-power-save".equals(name) && allowAll) {
String pkgname = parser.getAttributeValue(null, "package");
if (pkgname == null) {
Slog.w(TAG, "<allow-in-power-save> without package in " + permFile + " at "
+ parser.getPositionDescription());
} else {
mAllowInPowerSave.add(pkgname);
}
XmlUtils.skipCurrentTag(parser);
continue;
} else if ("allow-in-data-usage-save".equals(name) && allowAll) {
String pkgname = parser.getAttributeValue(null, "package");
if (pkgname == null) {
Slog.w(TAG, "<allow-in-data-usage-save> without package in " + permFile
+ " at " + parser.getPositionDescription());
} else {
mAllowInDataUsageSave.add(pkgname);
}
XmlUtils.skipCurrentTag(parser);
continue;
} else if ("app-link".equals(name) && allowAppConfigs) {
String pkgname = parser.getAttributeValue(null, "package");
if (pkgname == null) {
Slog.w(TAG, "<app-link> without package in " + permFile + " at "
+ parser.getPositionDescription());
} else {
mLinkedApps.add(pkgname);
}
XmlUtils.skipCurrentTag(parser);
} else if ("system-user-whitelisted-app".equals(name) && allowAppConfigs) {
String pkgname = parser.getAttributeValue(null, "package");
if (pkgname == null) {
Slog.w(TAG, "<system-user-whitelisted-app> without package in " + permFile
+ " at " + parser.getPositionDescription());
} else {
mSystemUserWhitelistedApps.add(pkgname);
}
XmlUtils.skipCurrentTag(parser);
} else if ("system-user-blacklisted-app".equals(name) && allowAppConfigs) {
String pkgname = parser.getAttributeValue(null, "package");
if (pkgname == null) {
Slog.w(TAG, "<system-user-blacklisted-app without package in " + permFile
+ " at " + parser.getPositionDescription());
} else {
mSystemUserBlacklistedApps.add(pkgname);
}
XmlUtils.skipCurrentTag(parser);
} else if ("default-enabled-vr-app".equals(name) && allowAppConfigs) {
String pkgname = parser.getAttributeValue(null, "package");
String clsname = parser.getAttributeValue(null, "class");
if (pkgname == null) {
Slog.w(TAG, "<default-enabled-vr-app without package in " + permFile
+ " at " + parser.getPositionDescription());
} else if (clsname == null) {
Slog.w(TAG, "<default-enabled-vr-app without class in " + permFile
+ " at " + parser.getPositionDescription());
} else {
mDefaultVrComponents.add(new ComponentName(pkgname, clsname));
}
XmlUtils.skipCurrentTag(parser);
} else if ("backup-transport-whitelisted-service".equals(name) && allowFeatures) {
String serviceName = parser.getAttributeValue(null, "service");
if (serviceName == null) {
Slog.w(TAG, "<backup-transport-whitelisted-service> without service in "
+ permFile + " at " + parser.getPositionDescription());
} else {
ComponentName cn = ComponentName.unflattenFromString(serviceName);
if (cn == null) {
Slog.w(TAG,
"<backup-transport-whitelisted-service> with invalid service name "
+ serviceName + " in "+ permFile
+ " at " + parser.getPositionDescription());
} else {
mBackupTransportWhitelist.add(cn);
}
}
XmlUtils.skipCurrentTag(parser);
} else if ("disabled-until-used-preinstalled-carrier-associated-app".equals(name)
&& allowAppConfigs) {
String pkgname = parser.getAttributeValue(null, "package");
String carrierPkgname = parser.getAttributeValue(null, "carrierAppPackage");
if (pkgname == null || carrierPkgname == null) {
Slog.w(TAG, "<disabled-until-used-preinstalled-carrier-associated-app"
+ " without package or carrierAppPackage in " + permFile + " at "
+ parser.getPositionDescription());
} else {
List<String> associatedPkgs =
mDisabledUntilUsedPreinstalledCarrierAssociatedApps.get(
carrierPkgname);
if (associatedPkgs == null) {
associatedPkgs = new ArrayList<>();
mDisabledUntilUsedPreinstalledCarrierAssociatedApps.put(
carrierPkgname, associatedPkgs);
}
associatedPkgs.add(pkgname);
}
XmlUtils.skipCurrentTag(parser);
} else {
XmlUtils.skipCurrentTag(parser);
continue;
}
}
} catch (XmlPullParserException e) {
Slog.w(TAG, "Got exception parsing permissions.", e);
} catch (IOException e) {
Slog.w(TAG, "Got exception parsing permissions.", e);
} finally {
IoUtils.closeQuietly(permReader);
}
// Some devices can be field-converted to FBE, so offer to splice in
// those features if not already defined by the static config
if (StorageManager.isFileEncryptedNativeOnly()) {
addFeature(PackageManager.FEATURE_FILE_BASED_ENCRYPTION, 0);
addFeature(PackageManager.FEATURE_SECURELY_REMOVES_USERS, 0);
}
for (String featureName : mUnavailableFeatures) {
removeFeature(featureName);
}
}
private void addFeature(String name, int version) {
FeatureInfo fi = mAvailableFeatures.get(name);
if (fi == null) {
fi = new FeatureInfo();
fi.name = name;
fi.version = version;
mAvailableFeatures.put(name, fi);
} else {
fi.version = Math.max(fi.version, version);
}
}
private void removeFeature(String name) {
if (mAvailableFeatures.remove(name) != null) {
Slog.d(TAG, "Removed unavailable feature " + name);
}
}
void readPermission(XmlPullParser parser, String name)
throws IOException, XmlPullParserException {
if (mPermissions.containsKey(name)) {
throw new IllegalStateException("Duplicate permission definition for " + name);
}
final boolean perUser = XmlUtils.readBooleanAttribute(parser, "perUser", false);
final PermissionEntry perm = new PermissionEntry(name, perUser);
mPermissions.put(name, perm);
int outerDepth = parser.getDepth();
int type;
while ((type=parser.next()) != XmlPullParser.END_DOCUMENT
&& (type != XmlPullParser.END_TAG
|| parser.getDepth() > outerDepth)) {
if (type == XmlPullParser.END_TAG
|| type == XmlPullParser.TEXT) {
continue;
}
String tagName = parser.getName();
if ("group".equals(tagName)) {
String gidStr = parser.getAttributeValue(null, "gid");
if (gidStr != null) {
int gid = Process.getGidForName(gidStr);
perm.gids = appendInt(perm.gids, gid);
} else {
Slog.w(TAG, "<group> without gid at "
+ parser.getPositionDescription());
}
}
XmlUtils.skipCurrentTag(parser);
}
}
}