Files
frameworks_base/services/java/com/android/server/pm/Installer.java
Mårten Kongstad 48d22323ce Runtime resource overlay, iteration 2
Support any number of overlay packages. Support any target package.

UPDATED PACKAGE MATCHING
------------------------
In Runtime resource overlay, iteration 1, only a single overlay package
was considered. Package matching was based on file paths:
/vendor/overlay/system/framework-res.apk corresponded to
/system/framework-res.apk. Introduce a more flexible matching scheme
where any package is an overlay package if its manifest includes

    <overlay targetPackage="com.target.package"/>

For security reasons, an overlay package must fulfill certain criteria
to take effect: see below.

THE IDMAP TOOL AND IDMAP FILES
------------------------------
Idmap files are created by the 'idmap' binary; idmap files must be
present when loading packages. For the Android system, Zygote calls
'idmap' as part of the resource pre-loading. For application packages,
'idmap' is invoked via 'installd' during package installation (similar
to 'dexopt').

UPDATED FLOW
------------
The following is an outline of the start-up sequences for the Android
system and Android apps. Steps marked with '+' are introduced by this
commit.

Zygote initialization
   Initial AssetManager object created
+    idmap --scan creates idmaps for overlays targeting 'android', \
           stores list of overlays in /data/resource-cache/overlays.list
   AssetManager caches framework-res.apk
+  AssetManager caches overlay packages listed in overlays.list

Android boot
   New AssetManager's ResTable acquired
     AssetManager re-uses cached framework-res.apk
+    AssetManager re-uses cached 'android' overlays (if any)

App boot
   ActivityThread prepares AssetManager to load app.apk
+  ActivityThread prepares AssetManager to load app overlays (if any)
   New AssetManager's ResTable acquired as per Android boot

SECURITY
--------
Overlay packages are required to be pre-loaded (in /vendor/overlay).
These packages are trusted by definition. A future iteration of runtime
resource overlay may add support for downloaded overlays, which would
likely require target and overlay signatures match for the overlay to
be trusted.

LOOKUP PRIORITY
---------------
During resource lookup, packages are sequentially queried to provide a
best match, given the constraints of the current configuration. If any
package provide a better match than what has been found so far, it
replaces the previous match. The target package is always queried last.

When loading a package with more than one overlay, the order in which
the overlays are added become significant if several packages overlay
the same resource.

Had downloaded overlays been supported, the install time could have been
used to determine the load order. Regardless, for pre-installed
overlays, the install time is randomly determined by the order in which
the Package Manager locates the packages during initial boot. To support
a well-defined order, pre-installed overlay packages are expected to
define an additional 'priority' attribute in their <overlay> tags:

    <overlay targetPackage="com.target.package" priority="1234"/>

Pre-installed overlays are loaded in order of their priority attributes,
sorted in ascending order.

Assigning the same priority to several overlays targeting the same base
package leads to undefined behaviour. It is the responsibility of the
vendor to avoid this.

The following example shows the ResTable and PackageGroups after loading
an application and two overlays. The resource lookup framework will
query the packages in the order C, B, A.

        +------+------+-     -+------+------+
        | 0x01 |      |  ...  |      | 0x7f |
        +------+------+-     -+------+------+
            |                           |
        "android"                Target package A
                                        |
                       Pre-installed overlay B (priority 1)
                                        |
                       Pre-installed overlay C (priority 2)

Change-Id: If49c963149369b1957f7d2303b3dd27f669ed24e
2014-02-03 11:20:30 +01:00

387 lines
11 KiB
Java

/*
* 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.
*/
package com.android.server.pm;
import android.content.pm.PackageStats;
import android.net.LocalSocket;
import android.net.LocalSocketAddress;
import android.util.Slog;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
public final class Installer {
private static final String TAG = "Installer";
private static final boolean LOCAL_DEBUG = false;
InputStream mIn;
OutputStream mOut;
LocalSocket mSocket;
byte buf[] = new byte[1024];
int buflen = 0;
private boolean connect() {
if (mSocket != null) {
return true;
}
Slog.i(TAG, "connecting...");
try {
mSocket = new LocalSocket();
LocalSocketAddress address = new LocalSocketAddress("installd",
LocalSocketAddress.Namespace.RESERVED);
mSocket.connect(address);
mIn = mSocket.getInputStream();
mOut = mSocket.getOutputStream();
} catch (IOException ex) {
disconnect();
return false;
}
return true;
}
private void disconnect() {
Slog.i(TAG, "disconnecting...");
try {
if (mSocket != null)
mSocket.close();
} catch (IOException ex) {
}
try {
if (mIn != null)
mIn.close();
} catch (IOException ex) {
}
try {
if (mOut != null)
mOut.close();
} catch (IOException ex) {
}
mSocket = null;
mIn = null;
mOut = null;
}
private boolean readBytes(byte buffer[], int len) {
int off = 0, count;
if (len < 0)
return false;
while (off != len) {
try {
count = mIn.read(buffer, off, len - off);
if (count <= 0) {
Slog.e(TAG, "read error " + count);
break;
}
off += count;
} catch (IOException ex) {
Slog.e(TAG, "read exception");
break;
}
}
if (LOCAL_DEBUG) {
Slog.i(TAG, "read " + len + " bytes");
}
if (off == len)
return true;
disconnect();
return false;
}
private boolean readReply() {
int len;
buflen = 0;
if (!readBytes(buf, 2))
return false;
len = (((int) buf[0]) & 0xff) | ((((int) buf[1]) & 0xff) << 8);
if ((len < 1) || (len > 1024)) {
Slog.e(TAG, "invalid reply length (" + len + ")");
disconnect();
return false;
}
if (!readBytes(buf, len))
return false;
buflen = len;
return true;
}
private boolean writeCommand(String _cmd) {
byte[] cmd = _cmd.getBytes();
int len = cmd.length;
if ((len < 1) || (len > 1024))
return false;
buf[0] = (byte) (len & 0xff);
buf[1] = (byte) ((len >> 8) & 0xff);
try {
mOut.write(buf, 0, 2);
mOut.write(cmd, 0, len);
} catch (IOException ex) {
Slog.e(TAG, "write error");
disconnect();
return false;
}
return true;
}
private synchronized String transaction(String cmd) {
if (!connect()) {
Slog.e(TAG, "connection failed");
return "-1";
}
if (!writeCommand(cmd)) {
/*
* If installd died and restarted in the background (unlikely but
* possible) we'll fail on the next write (this one). Try to
* reconnect and write the command one more time before giving up.
*/
Slog.e(TAG, "write command failed? reconnect!");
if (!connect() || !writeCommand(cmd)) {
return "-1";
}
}
if (LOCAL_DEBUG) {
Slog.i(TAG, "send: '" + cmd + "'");
}
if (readReply()) {
String s = new String(buf, 0, buflen);
if (LOCAL_DEBUG) {
Slog.i(TAG, "recv: '" + s + "'");
}
return s;
} else {
if (LOCAL_DEBUG) {
Slog.i(TAG, "fail");
}
return "-1";
}
}
private int execute(String cmd) {
String res = transaction(cmd);
try {
return Integer.parseInt(res);
} catch (NumberFormatException ex) {
return -1;
}
}
public int install(String name, int uid, int gid, String seinfo) {
StringBuilder builder = new StringBuilder("install");
builder.append(' ');
builder.append(name);
builder.append(' ');
builder.append(uid);
builder.append(' ');
builder.append(gid);
builder.append(' ');
builder.append(seinfo != null ? seinfo : "!");
return execute(builder.toString());
}
public int dexopt(String apkPath, int uid, boolean isPublic) {
StringBuilder builder = new StringBuilder("dexopt");
builder.append(' ');
builder.append(apkPath);
builder.append(' ');
builder.append(uid);
builder.append(isPublic ? " 1" : " 0");
return execute(builder.toString());
}
public int idmap(String targetApkPath, String overlayApkPath, int uid) {
StringBuilder builder = new StringBuilder("idmap");
builder.append(' ');
builder.append(targetApkPath);
builder.append(' ');
builder.append(overlayApkPath);
builder.append(' ');
builder.append(uid);
return execute(builder.toString());
}
public int movedex(String srcPath, String dstPath) {
StringBuilder builder = new StringBuilder("movedex");
builder.append(' ');
builder.append(srcPath);
builder.append(' ');
builder.append(dstPath);
return execute(builder.toString());
}
public int rmdex(String codePath) {
StringBuilder builder = new StringBuilder("rmdex");
builder.append(' ');
builder.append(codePath);
return execute(builder.toString());
}
public int remove(String name, int userId) {
StringBuilder builder = new StringBuilder("remove");
builder.append(' ');
builder.append(name);
builder.append(' ');
builder.append(userId);
return execute(builder.toString());
}
public int rename(String oldname, String newname) {
StringBuilder builder = new StringBuilder("rename");
builder.append(' ');
builder.append(oldname);
builder.append(' ');
builder.append(newname);
return execute(builder.toString());
}
public int fixUid(String name, int uid, int gid) {
StringBuilder builder = new StringBuilder("fixuid");
builder.append(' ');
builder.append(name);
builder.append(' ');
builder.append(uid);
builder.append(' ');
builder.append(gid);
return execute(builder.toString());
}
public int deleteCacheFiles(String name, int userId) {
StringBuilder builder = new StringBuilder("rmcache");
builder.append(' ');
builder.append(name);
builder.append(' ');
builder.append(userId);
return execute(builder.toString());
}
public int createUserData(String name, int uid, int userId, String seinfo) {
StringBuilder builder = new StringBuilder("mkuserdata");
builder.append(' ');
builder.append(name);
builder.append(' ');
builder.append(uid);
builder.append(' ');
builder.append(userId);
builder.append(' ');
builder.append(seinfo != null ? seinfo : "!");
return execute(builder.toString());
}
public int removeUserDataDirs(int userId) {
StringBuilder builder = new StringBuilder("rmuser");
builder.append(' ');
builder.append(userId);
return execute(builder.toString());
}
public int clearUserData(String name, int userId) {
StringBuilder builder = new StringBuilder("rmuserdata");
builder.append(' ');
builder.append(name);
builder.append(' ');
builder.append(userId);
return execute(builder.toString());
}
public boolean ping() {
if (execute("ping") < 0) {
return false;
} else {
return true;
}
}
public int freeCache(long freeStorageSize) {
StringBuilder builder = new StringBuilder("freecache");
builder.append(' ');
builder.append(String.valueOf(freeStorageSize));
return execute(builder.toString());
}
public int getSizeInfo(String pkgName, int persona, String apkPath, String libDirPath,
String fwdLockApkPath, String asecPath, PackageStats pStats) {
StringBuilder builder = new StringBuilder("getsize");
builder.append(' ');
builder.append(pkgName);
builder.append(' ');
builder.append(persona);
builder.append(' ');
builder.append(apkPath);
builder.append(' ');
builder.append(libDirPath != null ? libDirPath : "!");
builder.append(' ');
builder.append(fwdLockApkPath != null ? fwdLockApkPath : "!");
builder.append(' ');
builder.append(asecPath != null ? asecPath : "!");
String s = transaction(builder.toString());
String res[] = s.split(" ");
if ((res == null) || (res.length != 5)) {
return -1;
}
try {
pStats.codeSize = Long.parseLong(res[1]);
pStats.dataSize = Long.parseLong(res[2]);
pStats.cacheSize = Long.parseLong(res[3]);
pStats.externalCodeSize = Long.parseLong(res[4]);
return Integer.parseInt(res[0]);
} catch (NumberFormatException e) {
return -1;
}
}
public int moveFiles() {
return execute("movefiles");
}
/**
* Links the native library directory in an application's directory to its
* real location.
*
* @param dataPath data directory where the application is
* @param nativeLibPath target native library path
* @return -1 on error
*/
public int linkNativeLibraryDirectory(String dataPath, String nativeLibPath, int userId) {
if (dataPath == null) {
Slog.e(TAG, "linkNativeLibraryDirectory dataPath is null");
return -1;
} else if (nativeLibPath == null) {
Slog.e(TAG, "linkNativeLibraryDirectory nativeLibPath is null");
return -1;
}
StringBuilder builder = new StringBuilder("linklib ");
builder.append(dataPath);
builder.append(' ');
builder.append(nativeLibPath);
builder.append(' ');
builder.append(userId);
return execute(builder.toString());
}
}