前言：最近工作涉及到platform.xml的修改，其中涉及的条目还是挺多的，就着周末有时间梳理一下。
扩展阅读：
1.doze模式： https://developer.android.com/training/monitoring-device-state/doze-standby?hl=zh-cn
2. https://blog.csdn.net/licaomengRICE/article/details/48735957
1. platform.xml存放位置
platform.xml其实是将aosp中的配置文件直接拷贝到手机目录中1.1 手机存放位置
如下所示，手机中所存放的位置是位于/system/etc/permissions下
1.2 aosp中位置
在aosp中是放在framework/base/data/etc/下的
2. platform.xml内容
摘自小米mix 2:
<?xml version="1.0" encoding="utf-8"?>
<!-- Copyright (C) 2008 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.
-->
<!-- This file is used to define the mappings between lower-level system
user and group IDs and the higher-level permission names managed
by the platform.
Be VERY careful when editing this file! Mistakes made here can open
big security holes.
-->
<permissions>
<!-- ================================================================== -->
<!-- ================================================================== -->
<!-- ================================================================== -->
<!-- The following tags are associating low-level group IDs with
permission names. By specifying such a mapping, you are saying
that any application process granted the given permission will
also be running with the given group ID attached to its process,
so it can perform any filesystem (read, write, execute) operations
allowed for that group. -->
<permission name="android.permission.BLUETOOTH_ADMIN" >
<group gid="net_bt_admin" />
</permission>
<permission name="android.permission.BLUETOOTH" >
<group gid="net_bt" />
</permission>
<permission name="android.permission.BLUETOOTH_STACK" >
<group gid="bluetooth" />
<group gid="wakelock" />
</permission>
<permission name="android.permission.NET_TUNNELING" >
<group gid="vpn" />
</permission>
<permission name="android.permission.INTERNET" >
<group gid="inet" />
</permission>
<permission name="android.permission.READ_LOGS" >
<group gid="log" />
</permission>
<permission name="android.permission.WRITE_MEDIA_STORAGE" >
<group gid="media_rw" />
<group gid="sdcard_rw" />
</permission>
<permission name="android.permission.ACCESS_MTP" >
<group gid="mtp" />
</permission>
<permission name="android.permission.NET_ADMIN" >
<group gid="net_admin" />
</permission>
<!-- The group that /cache belongs to, linked to the permission
set on the applications that can access /cache -->
<permission name="android.permission.ACCESS_CACHE_FILESYSTEM" >
<group gid="cache" />
</permission>
<!-- RW permissions to any system resources owned by group 'diag'.
This is for carrier and manufacture diagnostics tools that must be
installable from the framework. Be careful. -->
<permission name="android.permission.DIAGNOSTIC" >
<group gid="input" />
<group gid="diag" />
</permission>
<!-- Group that can read detailed network usage statistics -->
<permission name="android.permission.READ_NETWORK_USAGE_HISTORY">
<group gid="net_bw_stats" />
</permission>
<!-- Group that can modify how network statistics are accounted -->
<permission name="android.permission.MODIFY_NETWORK_ACCOUNTING">
<group gid="net_bw_acct" />
</permission>
<permission name="android.permission.LOOP_RADIO" >
<group gid="loop_radio" />
</permission>
<!-- Hotword training apps sometimes need a GID to talk with low-level
hardware; give them audio for now until full HAL support is added. -->
<permission name="android.permission.MANAGE_VOICE_KEYPHRASES">
<group gid="audio" />
</permission>
<permission name="android.permission.ACCESS_FM_RADIO" >
<!-- /dev/fm is gid media, not audio -->
<group gid="media" />
</permission>
<!-- These are permissions that were mapped to gids but we need
to keep them here until an upgrade from L to the current
version is to be supported. These permissions are built-in
and in L were not stored in packages.xml as a result if they
are not defined here while parsing packages.xml we would
ignore these permissions being granted to apps and not
propagate the granted state. From N we are storing the
built-in permissions in packages.xml as the saved storage
is negligible (one tag with the permission) compared to
the fragility as one can remove a built-in permission which
no longer needs to be mapped to gids and break grant propagation. -->
<permission name="android.permission.READ_EXTERNAL_STORAGE" />
<permission name="android.permission.WRITE_EXTERNAL_STORAGE" />
<!-- ================================================================== -->
<!-- ================================================================== -->
<!-- ================================================================== -->
<!-- The following tags are assigning high-level permissions to specific
user IDs. These are used to allow specific core system users to
perform the given operations with the higher-level framework. For
example, we give a wide variety of permissions to the shell user
since that is the user the adb shell runs under and developers and
others should have a fairly open environment in which to
interact with the system. -->
<assign-permission name="android.permission.MODIFY_AUDIO_SETTINGS" uid="media" />
<assign-permission name="android.permission.ACCESS_SURFACE_FLINGER" uid="media" />
<assign-permission name="android.permission.WAKE_LOCK" uid="media" />
<assign-permission name="android.permission.UPDATE_DEVICE_STATS" uid="media" />
<assign-permission name="android.permission.UPDATE_APP_OPS_STATS" uid="media" />
<assign-permission name="android.permission.GET_PROCESS_STATE_AND_OOM_SCORE" uid="media" />
<assign-permission name="android.permission.MODIFY_AUDIO_SETTINGS" uid="audioserver" />
<assign-permission name="android.permission.ACCESS_SURFACE_FLINGER" uid="audioserver" />
<assign-permission name="android.permission.WAKE_LOCK" uid="audioserver" />
<assign-permission name="android.permission.UPDATE_DEVICE_STATS" uid="audioserver" />
<assign-permission name="android.permission.UPDATE_APP_OPS_STATS" uid="audioserver" />
<assign-permission name="android.permission.MODIFY_AUDIO_SETTINGS" uid="cameraserver" />
<assign-permission name="android.permission.ACCESS_SURFACE_FLINGER" uid="cameraserver" />
<assign-permission name="android.permission.WAKE_LOCK" uid="cameraserver" />
<assign-permission name="android.permission.UPDATE_DEVICE_STATS" uid="cameraserver" />
<assign-permission name="android.permission.UPDATE_APP_OPS_STATS" uid="cameraserver" />
<assign-permission name="android.permission.GET_PROCESS_STATE_AND_OOM_SCORE" uid="cameraserver" />
<assign-permission name="android.permission.ACCESS_SURFACE_FLINGER" uid="graphics" />
<!-- MIUI ADD -->
<!-- for bootaudio setVolumeIndex-->
<assign-permission name="android.permission.MODIFY_AUDIO_SETTINGS" uid="graphics" />
<!-- This is a list of all the libraries available for application
code to link against. -->
<library name="android.test.runner"
file="/system/framework/android.test.runner.jar" />
<library name="javax.obex"
file="/system/framework/javax.obex.jar" />
<library name="org.apache.http.legacy"
file="/system/framework/org.apache.http.legacy.jar" />
<!-- These are the standard packages that are white-listed to always have internet
access while in power save mode, even if they aren't in the foreground. -->
<allow-in-power-save package="com.android.providers.downloads" />
<!-- These are the standard packages that are white-listed to always have internet
access while in data mode, even if they aren't in the foreground. -->
<allow-in-data-usage-save package="com.android.providers.downloads" />
<!-- This is a core platform component that needs to freely run in the background -->
<allow-in-power-save package="com.android.cellbroadcastreceiver" />
<allow-in-power-save package="com.android.shell" />
<!-- These are the packages that are white-listed to be able to run as system user -->
<system-user-whitelisted-app package="com.android.settings" />
<!-- These are the packages that shouldn't run as system user -->
<system-user-blacklisted-app package="com.android.wallpaper.livepicker" />
</permissions>3. platform.xml内容梳理
关键tag:
- <permission>
- <assign-permission>
- <library>
- <allow-in-power-save>
- <allow-in-data-usage-save>
- <system-user-whitelisted-app>
- <system-user-blacklisted-app>
3.1 警告部分
说明这个文件是处理普通用户和系统权限之间映射的，如果擅自改动，会造成大的安全漏洞。
<!-- This file is used to define the mappings between lower-level system
user and group IDs and the higher-level permission names managed
by the platform.
Be VERY careful when editing this file! Mistakes made here can open
big security holes.
-->3.2 权限映射
<permission>将低等级的groups id和权限名称相关联。通过指定这样的映射，表明了一个授予了给定权限的应用进程将附带这所给的group id运行，因此它可以执行这个群组所允许的读写和执行操作。
<!-- The following tags are associating low-level group IDs with
permission names. By specifying such a mapping, you are saying
that any application process granted the given permission will
also be running with the given group ID attached to its process,
so it can perform any filesystem (read, write, execute) operations
allowed for that group. -->
<permission name="android.permission.BLUETOOTH_ADMIN" >
<group gid="net_bt_admin" />
</permission>有个例外：
<!-- These are permissions that were mapped to gids but we need
to keep them here until an upgrade from L to the current
version is to be supported. These permissions are built-in
and in L were not stored in packages.xml as a result if they
are not defined here while parsing packages.xml we would
ignore these permissions being granted to apps and not
propagate the granted state. From N we are storing the
built-in permissions in packages.xml as the saved storage
is negligible (one tag with the permission) compared to
the fragility as one can remove a built-in permission which
no longer needs to be mapped to gids and break grant propagation. -->
<permission name="android.permission.READ_EXTERNAL_STORAGE" />
<permission name="android.permission.WRITE_EXTERNAL_STORAGE" />3.3 分配权限
<assign-permission>:有些用户比较特殊，它们是系统核心用户，Android会分配特定的高级权限来允许它们来完成一些高级的操作。比如，shell用户有很多权限，这是因为开发者需要比较开放的环境来和system进行交互。
shell用户的权限有时候需要adb root/adb remount才能享受，对应的需要userdebug或者root版本，user版本下shell命令还是有所限制的。
<!-- The following tags are assigning high-level permissions to specific
user IDs. These are used to allow specific core system users to
perform the given operations with the higher-level framework. For
example, we give a wide variety of permissions to the shell user
since that is the user the adb shell runs under and developers and
others should have a fairly open environment in which to
interact with the system. -->
<assign-permission name="android.permission.MODIFY_AUDIO_SETTINGS" uid="media" />
<assign-permission name="android.permission.ACCESS_SURFACE_FLINGER" uid="media" />3.4 库
<library>:应用可以链接到的库，可以理解为应用可以调用到的jar？
<!-- This is a list of all the libraries available for application
code to link against. -->
<library name="android.test.runner"
file="/system/framework/android.test.runner.jar" />
<library name="javax.obex"
file="/system/framework/javax.obex.jar" />
<library name="org.apache.http.legacy"
file="/system/framework/org.apache.http.legacy.jar" />3.5 省电优化白名单
<allow-in-power-save>: 这个对应于手机中的省电优化设置，用这个tag配置在这张表中就代表该应用不受省电优化显示，可以在后台访问网络。对应应用在原生设置中的电源菜单也是灰显，不可设置优化的。
<!-- These are the standard packages that are white-listed to always have internet
access while in power save mode, even if they aren't in the foreground. -->
<allow-in-power-save package="com.android.providers.downloads" /><!-- This is a core platform component that needs to freely run in the background -->
<allow-in-power-save package="com.android.cellbroadcastreceiver" />
<allow-in-power-save package="com.android.shell" />这个tag也和doze mode有些关系
可以使用命令查看：adb shell dumpsys deviceidle whitelist
chiron:/system/etc/permissions $ dumpsys deviceidle whitelist
system-excidle,com.android.providers.downloads,10012
system-excidle,com.qualcomm.qti.telephonyservice,1001
system-excidle,com.qualcomm.qti.radioconfiginterface,1001
system-excidle,com.android.cellbroadcastreceiver,10007
system-excidle,com.qualcomm.qti.ims,1001
system-excidle,com.android.shell,2000
system,com.android.providers.downloads,10012
system,com.qualcomm.qti.telephonyservice,1001
system,com.qualcomm.qti.radioconfiginterface,1001
system,com.android.cellbroadcastreceiver,10007
system,com.qualcomm.qti.ims,1001
system,com.android.shell,2000
user,com.android.cts.priv.ctsshim,10009
user,com.qualcomm.qti.auth.sampleextauthservice,10077
user,com.miui.contentextension,10113
user,com.unionpay.tsmservice.mi,10086
3.6 数据白名单
<!-- These are the standard packages that are white-listed to always have internet
access while in data mode, even if they aren't in the foreground. -->
<allow-in-data-usage-save package="com.android.providers.downloads" />3.7 系统应用白名单
<!-- These are the packages that are white-listed to be able to run as system user -->
<system-user-whitelisted-app package="com.android.settings" />设置是系统应用，可以看它的AndroidManifest.xml：
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:androidprv="http://schemas.android.com/apk/prv/res/android"
package="com.android.settings"
coreApp="true"
android:sharedUserId="android.uid.system">3.8 系统应用黑名单
<!-- These are the packages that shouldn't run as system user -->
<system-user-blacklisted-app package="com.android.wallpaper.livepicker" />4. platform.xml对应的解析代码
xml肯定是需要解析才能用的，/frameworks/core/java/com/android/server/SystemConfig.java 这个SystemConfig就是来解析platform.xml，然后供一个个系统接口用作返回值的依据。
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;
boolean allowPrivappPermissions = (permissionFlag & ALLOW_PRIVAPP_PERMISSIONS) != 0;
boolean allowApiWhitelisting = (permissionFlag & ALLOW_HIDDENAPI_WHITELISTING) != 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 ("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 ("allow-unthrottled-location".equals(name) && allowAll) {
String pkgname = parser.getAttributeValue(null, "package");
if (pkgname == null) {
Slog.w(TAG, "<allow-unthrottled-location> without package in "
+ permFile + " at " + parser.getPositionDescription());
} else {
mAllowUnthrottledLocation.add(pkgname);
}
XmlUtils.skipCurrentTag(parser);
continue;
} else if ("allow-implicit-broadcast".equals(name) && allowAll) {
String action = parser.getAttributeValue(null, "action");
if (action == null) {
Slog.w(TAG, "<allow-implicit-broadcast> without action in " + permFile
+ " at " + parser.getPositionDescription());
} else {
mAllowImplicitBroadcasts.add(action);
}
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 if ("privapp-permissions".equals(name) && allowPrivappPermissions) {
readPrivAppPermissions(parser);
} else if ("hidden-api-whitelisted-app".equals(name) && allowApiWhitelisting) {
String pkgname = parser.getAttributeValue(null, "package");
if (pkgname == null) {
Slog.w(TAG, "<hidden-api-whitelisted-app> without package in " + permFile
+ " at " + parser.getPositionDescription());
} else {
mHiddenApiPackageWhitelist.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);
}
if (ActivityManager.isLowRamDeviceStatic()) {
addFeature(PackageManager.FEATURE_RAM_LOW, 0);
} else {
addFeature(PackageManager.FEATURE_RAM_NORMAL, 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);
}
}5. 总结
整篇博客其实对platform.xml的分析还是比较肤浅的，<allow-in-power-save>了解的稍微好一点，后续接着对应的系统调用看下配置各项属性真正的作用才算真正的对这个xml有所了解吧。