1/*
2 * Copyright (C) 2011 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#define LOG_TAG "FullBackup_native"
18#include <sys/stat.h>
19
20#include <utils/Log.h>
21#include <utils/String8.h>
22
23#include "JNIHelp.h"
24#include <android_runtime/AndroidRuntime.h>
25
26#include <androidfw/BackupHelpers.h>
27
28#include "core_jni_helpers.h"
29
30#include <string.h>
31
32namespace android
33{
34
35// android.app.backup.FullBackupDataOutput
36static struct {
37    jfieldID mData;         // type android.app.backup.BackupDataOutput
38    jmethodID addSize;
39} sFullBackupDataOutput;
40
41// android.app.backup.BackupDataOutput
42static struct {
43    // This is actually a native pointer to the underlying BackupDataWriter instance
44    jfieldID mBackupWriter;
45} sBackupDataOutput;
46
47/*
48 * Write files to the given output.  This implementation does *not* create
49 * a standalone archive suitable for restore on its own.  In particular, the identification of
50 * the application's name etc is not in-band here; it's assumed that the calling code has
51 * taken care of supplying that information previously in the output stream.
52 *
53 * The file format is 'tar's, with special semantics applied by use of a "fake" directory
54 * hierarchy within the tar stream:
55 *
56 * apps/packagename/a/Filename.apk - this is an actual application binary, which will be
57 *   installed on the target device at restore time.  These need to appear first in the tar
58 *   stream.
59 * apps/packagename/obb/[relpath] - OBB containers belonging the app
60 * apps/packagename/r/[relpath] - these are files at the root of the app's data tree
61 * apps/packagename/f/[relpath] - this is a file within the app's getFilesDir() tree, stored
62 *   at [relpath] relative to the top of that tree.
63 * apps/packagename/db/[relpath] - as with "files" but for the getDatabasePath() tree
64 * apps/packagename/sp/[relpath] - as with "files" but for the getSharedPrefsFile() tree
65 * apps/packagename/c/[relpath] - as with "files" but for the getCacheDir() tree
66 *
67 * and for the shared storage hierarchy:
68 *
69 * shared/[relpaths] - files belonging in the device's shared storage location.  This will
70 *    *not* include .obb files; those are saved with their owning apps.
71 *
72 * This method writes one file data block.  'domain' is the name of the appropriate pseudo-
73 * directory to be applied for this file; 'linkdomain' is the pseudo-dir for a relative
74 * symlink's antecedent.
75 *
76 * packagename: the package name to use as the top level directory tag
77 * domain:      which semantic name the file is to be stored under (a, r, f, db, etc)
78 * linkdomain:  where a symlink points for purposes of rewriting; current unused
79 * rootpath:    prefix to be snipped from full path when encoding in tar
80 * path:        absolute path to the file to be saved
81 * dataOutput:  the FullBackupDataOutput object that we're saving into
82 */
83static jint backupToTar(JNIEnv* env, jobject clazz, jstring packageNameObj,
84        jstring domainObj, jstring linkdomain,
85        jstring rootpathObj, jstring pathObj, jobject dataOutputObj) {
86    // Extract the various strings, allowing for null object pointers
87    const char* packagenamechars = (packageNameObj) ? env->GetStringUTFChars(packageNameObj, NULL) : NULL;
88    const char* rootchars = (rootpathObj) ? env->GetStringUTFChars(rootpathObj, NULL) : NULL;
89    const char* pathchars = (pathObj) ? env->GetStringUTFChars(pathObj, NULL) : NULL;
90    const char* domainchars = (domainObj) ? env->GetStringUTFChars(domainObj, NULL) : NULL;
91
92    String8 packageName(packagenamechars ? packagenamechars : "");
93    String8 rootpath(rootchars ? rootchars : "");
94    String8 path(pathchars ? pathchars : "");
95    String8 domain(domainchars ? domainchars : "");
96
97    if (domainchars) env->ReleaseStringUTFChars(domainObj, domainchars);
98    if (pathchars) env->ReleaseStringUTFChars(pathObj, pathchars);
99    if (rootchars) env->ReleaseStringUTFChars(rootpathObj, rootchars);
100    if (packagenamechars) env->ReleaseStringUTFChars(packageNameObj, packagenamechars);
101
102    // Extract the data output fd.  'writer' ends up NULL in the measure-only case.
103    jobject bdo = env->GetObjectField(dataOutputObj, sFullBackupDataOutput.mData);
104    BackupDataWriter* writer = (bdo != NULL)
105            ? (BackupDataWriter*) env->GetLongField(bdo, sBackupDataOutput.mBackupWriter)
106            : NULL;
107
108    if (path.length() < rootpath.length()) {
109        ALOGE("file path [%s] shorter than root path [%s]",
110                path.string(), rootpath.string());
111        return (jint) -1;
112    }
113
114    off_t tarSize = 0;
115    jint err = write_tarfile(packageName, domain, rootpath, path, &tarSize, writer);
116    if (!err) {
117        //ALOGI("measured [%s] at %lld", path.string(), (long long) tarSize);
118        env->CallVoidMethod(dataOutputObj, sFullBackupDataOutput.addSize, (jlong) tarSize);
119    }
120
121    return err;
122}
123
124static const JNINativeMethod g_methods[] = {
125    { "backupToTar",
126            "(Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;Landroid/app/backup/FullBackupDataOutput;)I",
127            (void*)backupToTar },
128};
129
130int register_android_app_backup_FullBackup(JNIEnv* env)
131{
132    jclass fbdoClazz = FindClassOrDie(env, "android/app/backup/FullBackupDataOutput");
133    sFullBackupDataOutput.mData = GetFieldIDOrDie(env, fbdoClazz, "mData", "Landroid/app/backup/BackupDataOutput;");
134    sFullBackupDataOutput.addSize = GetMethodIDOrDie(env, fbdoClazz, "addSize", "(J)V");
135
136    jclass bdoClazz = FindClassOrDie(env, "android/app/backup/BackupDataOutput");
137    sBackupDataOutput.mBackupWriter = GetFieldIDOrDie(env, bdoClazz, "mBackupWriter", "J");
138
139    return RegisterMethodsOrDie(env, "android/app/backup/FullBackup", g_methods, NELEM(g_methods));
140}
141
142}
143