1 /*
2 * Copyright (C) 2020 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 #include <sstream>
18 #include <string>
19 #include <vector>
20
21 #include <nativehelper/JNIHelp.h>
22 #include "jni.h"
23 #include "core_jni_helpers.h"
24
25 #include "android-base/logging.h"
26 #include "androidfw/PosixUtils.h"
27
28 using ::android::util::ExecuteBinary;
29
30 static jclass g_stringClass = nullptr;
31
createIdmap(JNIEnv * env,jclass,jstring targetPath,jobjectArray overlayPath,jobjectArray policies,jboolean enforceOverlayable)32 static jobjectArray createIdmap(JNIEnv* env, jclass /*clazz*/, jstring targetPath,
33 jobjectArray overlayPath, jobjectArray policies,
34 jboolean enforceOverlayable) {
35 if (access("/system/bin/idmap2", X_OK) == -1) {
36 PLOG(WARNING) << "unable to execute idmap2";
37 return nullptr;
38 }
39
40 const char* targetApkPath = env->GetStringUTFChars(targetPath, NULL /* isCopy */);
41 std::vector<std::string> argv{"/system/bin/idmap2",
42 "create-multiple",
43 "--target-apk-path", targetApkPath,
44 };
45 env->ReleaseStringUTFChars(targetPath, targetApkPath);
46
47 // Add the overlays for which to generate idmap files to the idmap arguments.
48 for (size_t i = 0, count = env->GetArrayLength(overlayPath); i < count; ++i) {
49 jstring element = (jstring) env->GetObjectArrayElement(overlayPath, i);
50 const char* overlayApkPath = env->GetStringUTFChars(element, NULL /* isCopy */);
51 argv.emplace_back("--overlay-apk-path");
52 argv.emplace_back(overlayApkPath);
53 env->ReleaseStringUTFChars(element, overlayApkPath);
54 }
55
56 // Add the policies the overlays fulfill to the idmap arguments.
57 for (size_t i = 0, count = env->GetArrayLength(policies); i < count; ++i) {
58 jstring element = (jstring)env->GetObjectArrayElement(policies, i);
59 const char* policy = env->GetStringUTFChars(element, NULL /* isCopy */);
60 argv.emplace_back("--policy");
61 argv.emplace_back(policy);
62 env->ReleaseStringUTFChars(element, policy);
63 }
64
65 if (!enforceOverlayable) {
66 argv.emplace_back("--ignore-overlayable");
67 }
68
69 auto result = ExecuteBinary(argv);
70 if (!result) {
71 LOG(ERROR) << "failed to execute idmap2";
72 return nullptr;
73 }
74
75 if (result.status != 0) {
76 LOG(ERROR) << "idmap2: " << result.stderr_str;
77 return nullptr;
78 }
79
80 // Return the paths of the idmaps created or updated during the idmap invocation.
81 std::vector<std::string> idmap_paths;
82 std::istringstream input(std::move(result.stdout_str));
83 std::string path;
84 while (std::getline(input, path)) {
85 idmap_paths.push_back(std::move(path));
86 }
87
88 jobjectArray array = env->NewObjectArray(idmap_paths.size(), g_stringClass, nullptr);
89 if (array == nullptr) {
90 return nullptr;
91 }
92 for (size_t i = 0; i < idmap_paths.size(); i++) {
93 const std::string& path = idmap_paths[i];
94 jstring java_string = env->NewStringUTF(path.c_str());
95 if (env->ExceptionCheck()) {
96 return nullptr;
97 }
98 env->SetObjectArrayElement(array, i, java_string);
99 env->DeleteLocalRef(java_string);
100 }
101
102 return array;
103 }
104
105 static const JNINativeMethod g_methods[] = {
106 { "createIdmap",
107 "(Ljava/lang/String;[Ljava/lang/String;[Ljava/lang/String;Z)[Ljava/lang/String;",
108 (void *)createIdmap },
109 };
110
111 static const char* const kOverlayConfigPathName = "com/android/internal/content/om/OverlayConfig";
112
113 namespace android {
114
register_com_android_internal_content_om_OverlayConfig(JNIEnv * env)115 int register_com_android_internal_content_om_OverlayConfig(JNIEnv* env) {
116 jclass stringClass = FindClassOrDie(env, "java/lang/String");
117 g_stringClass = MakeGlobalRefOrDie(env, stringClass);
118
119 return RegisterMethodsOrDie(env, kOverlayConfigPathName, g_methods, NELEM(g_methods));
120 }
121
122 } // namespace android
123