/*
* Copyright (C) 2010 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.email;
import com.android.email.activity.setup.AccountSettingsUtils.Provider;
import com.android.emailcommon.Logging;
import android.content.Context;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageManager.NameNotFoundException;
import android.os.Bundle;
import android.util.Log;
import java.lang.reflect.Method;
/**
* A bridge class to the email vendor policy apk.
*
* <p>Email vendor policy is a system apk named "com.android.email.helper". When exists, it must
* contain a class called "com.android.email.policy.EmailPolicy" with a static public method
* <code>Bundle getPolicy(String, Bundle)</code>, which serves vendor specific configurations.
*
* <p>A vendor policy apk is optional. The email application will operate properly when none is
* found.
*/
public class VendorPolicyLoader {
private static final String POLICY_PACKAGE = "com.android.email.policy";
private static final String POLICY_CLASS = POLICY_PACKAGE + ".EmailPolicy";
private static final String GET_POLICY_METHOD = "getPolicy";
private static final Class<?>[] ARGS = new Class<?>[] {String.class, Bundle.class};
// call keys and i/o bundle keys
// when there is only one parameter or return value, use call key
private static final String USE_ALTERNATE_EXCHANGE_STRINGS = "useAlternateExchangeStrings";
private static final String GET_IMAP_ID = "getImapId";
private static final String GET_IMAP_ID_USER = "getImapId.user";
private static final String GET_IMAP_ID_HOST = "getImapId.host";
private static final String GET_IMAP_ID_CAPA = "getImapId.capabilities";
private static final String FIND_PROVIDER = "findProvider";
private static final String FIND_PROVIDER_IN_URI = "findProvider.inUri";
private static final String FIND_PROVIDER_IN_USER = "findProvider.inUser";
private static final String FIND_PROVIDER_OUT_URI = "findProvider.outUri";
private static final String FIND_PROVIDER_OUT_USER = "findProvider.outUser";
private static final String FIND_PROVIDER_NOTE = "findProvider.note";
/** Singleton instance */
private static VendorPolicyLoader sInstance;
private final Method mPolicyMethod;
public static VendorPolicyLoader getInstance(Context context) {
if (sInstance == null) {
// It's okay to instantiate VendorPolicyLoader multiple times. No need to synchronize.
sInstance = new VendorPolicyLoader(context);
}
return sInstance;
}
/**
* For testing only.
*
* Replaces the instance with a new instance that loads a specified class.
*/
public static void injectPolicyForTest(Context context, String apkPackageName, Class<?> clazz) {
String name = clazz.getName();
Log.d(Logging.LOG_TAG, String.format("Using policy: package=%s name=%s",
apkPackageName, name));
sInstance = new VendorPolicyLoader(context, apkPackageName, name, true);
}
/**
* For testing only.
*
* Clear the instance so that the next {@link #getInstance} call will return a regular,
* non-injected instance.
*/
public static void clearInstanceForTest() {
sInstance = null;
}
private VendorPolicyLoader(Context context) {
this(context, POLICY_PACKAGE, POLICY_CLASS, false);
}
/**
* Constructor for testing, where we need to use an alternate package/class name, and skip
* the system apk check.
*/
/* package */ VendorPolicyLoader(Context context, String apkPackageName, String className,
boolean allowNonSystemApk) {
if (!allowNonSystemApk && !isSystemPackage(context, apkPackageName)) {
mPolicyMethod = null;
return;
}
Class<?> clazz = null;
Method method = null;
try {
final Context policyContext = context.createPackageContext(apkPackageName,
Context.CONTEXT_IGNORE_SECURITY | Context.CONTEXT_INCLUDE_CODE);
final ClassLoader classLoader = policyContext.getClassLoader();
clazz = classLoader.loadClass(className);
method = clazz.getMethod(GET_POLICY_METHOD, ARGS);
} catch (NameNotFoundException ignore) {
// Package not found -- it's okay - there's no policy .apk found, which is OK
} catch (ClassNotFoundException e) {
// Class not found -- probably not OK, but let's not crash here
Log.w(Logging.LOG_TAG, "VendorPolicyLoader: " + e);
} catch (NoSuchMethodException e) {
// Method not found -- probably not OK, but let's not crash here
Log.w(Logging.LOG_TAG, "VendorPolicyLoader: " + e);
}
mPolicyMethod = method;
}
// Not private for testing
/* package */ static boolean isSystemPackage(Context context, String packageName) {
try {
ApplicationInfo ai = context.getPackageManager().getApplicationInfo(packageName, 0);
return (ai.flags & ApplicationInfo.FLAG_SYSTEM) != 0;
} catch (NameNotFoundException e) {
return false; // Package not found.
}
}
/**
* Calls the getPolicy method in the policy apk, if one exists. This method never returns null;
* It returns an empty {@link Bundle} when there is no policy apk (or even if the inner
* getPolicy returns null).
*/
// Not private for testing
/* package */ Bundle getPolicy(String policy, Bundle args) {
Bundle ret = null;
if (mPolicyMethod != null) {
try {
ret = (Bundle) mPolicyMethod.invoke(null, policy, args);
} catch (Exception e) {
Log.w(Logging.LOG_TAG, "VendorPolicyLoader", e);
}
}
return (ret != null) ? ret : Bundle.EMPTY;
}
/**
* Returns true if alternate exchange descriptive text is required.
*
* Vendor function:
* Select: USE_ALTERNATE_EXCHANGE_STRINGS
* Params: none
* Result: USE_ALTERNATE_EXCHANGE_STRINGS (boolean)
*/
public boolean useAlternateExchangeStrings() {
return getPolicy(USE_ALTERNATE_EXCHANGE_STRINGS, null)
.getBoolean(USE_ALTERNATE_EXCHANGE_STRINGS, false);
}
/**
* Returns additional key/value pairs for the IMAP ID string.
*
* Vendor function:
* Select: GET_IMAP_ID
* Params: GET_IMAP_ID_USER (String)
* GET_IMAP_ID_HOST (String)
* GET_IMAP_ID_CAPABILITIES (String)
* Result: GET_IMAP_ID (String)
*
* @param userName the server that is being contacted (e.g. "imap.server.com")
* @param host the server that is being contacted (e.g. "imap.server.com")
* @param capabilities reported capabilities, if known. null is OK
* @return zero or more key/value pairs, quoted and delimited by spaces. If there is
* nothing to add, return null.
*/
public String getImapIdValues(String userName, String host, String capabilities) {
Bundle params = new Bundle();
params.putString(GET_IMAP_ID_USER, userName);
params.putString(GET_IMAP_ID_HOST, host);
params.putString(GET_IMAP_ID_CAPA, capabilities);
String result = getPolicy(GET_IMAP_ID, params).getString(GET_IMAP_ID);
return result;
}
/**
* Returns provider setup information for a given email address
*
* Vendor function:
* Select: FIND_PROVIDER
* Param: FIND_PROVIDER (String)
* Result: FIND_PROVIDER_IN_URI
* FIND_PROVIDER_IN_USER
* FIND_PROVIDER_OUT_URI
* FIND_PROVIDER_OUT_USER
* FIND_PROVIDER_NOTE (optional - null is OK)
*
* Note, if we get this far, we expect "correct" results from the policy method. But throwing
* checked exceptions requires a bunch of upstream changes, so we're going to catch them here
* and add logging. Other exceptions may escape here (such as null pointers) to fail fast.
*
* @param domain The domain portion of the user's email address
* @return suitable Provider definition, or null if no match found
*/
public Provider findProviderForDomain(String domain) {
Bundle params = new Bundle();
params.putString(FIND_PROVIDER, domain);
Bundle out = getPolicy(FIND_PROVIDER, params);
if (out != null && !out.isEmpty()) {
Provider p = new Provider();
p.id = null;
p.label = null;
p.domain = domain;
p.incomingUriTemplate = out.getString(FIND_PROVIDER_IN_URI);
p.incomingUsernameTemplate = out.getString(FIND_PROVIDER_IN_USER);
p.outgoingUriTemplate = out.getString(FIND_PROVIDER_OUT_URI);
p.outgoingUsernameTemplate = out.getString(FIND_PROVIDER_OUT_USER);
p.note = out.getString(FIND_PROVIDER_NOTE);
return p;
}
return null;
}
}