android_os_HwBinder.cpp revision 2cf5a3f46ce5697e50c6b582354ba08b11d93815 
1/*
2 * Copyright (C) 2016 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_NDEBUG 0
18#define LOG_TAG "android_os_HwBinder"
19#include <android-base/logging.h>
20
21#include "android_os_HwBinder.h"
22
23#include "android_os_HwParcel.h"
24#include "android_os_HwRemoteBinder.h"
25
26#include <cstring>
27
28#include <JNIHelp.h>
29#include <android/hidl/manager/1.0/IServiceManager.h>
30#include <android/hidl/base/1.0/IBase.h>
31#include <android/hidl/base/1.0/BpHwBase.h>
32#include <android_runtime/AndroidRuntime.h>
33#include <hidl/ServiceManagement.h>
34#include <hidl/Status.h>
35#include <hidl/HidlTransportSupport.h>
36#include <hwbinder/ProcessState.h>
37#include <nativehelper/ScopedLocalRef.h>
38#include <vintf/parse_string.h>
39
40#include "core_jni_helpers.h"
41
42using android::AndroidRuntime;
43using android::hardware::hidl_vec;
44using android::hardware::hidl_string;
45template<typename T>
46using Return = android::hardware::Return<T>;
47
48#define PACKAGE_PATH    "android/os"
49#define CLASS_NAME      "HwBinder"
50#define CLASS_PATH      PACKAGE_PATH "/" CLASS_NAME
51
52namespace android {
53
54static jclass gErrorClass;
55
56static struct fields_t {
57    jfieldID contextID;
58    jmethodID onTransactID;
59} gFields;
60
61// static
62void JHwBinder::InitClass(JNIEnv *env) {
63    ScopedLocalRef<jclass> clazz(
64            env, FindClassOrDie(env, CLASS_PATH));
65
66    gFields.contextID =
67        GetFieldIDOrDie(env, clazz.get(), "mNativeContext", "J");
68
69    gFields.onTransactID =
70        GetMethodIDOrDie(
71                env,
72                clazz.get(),
73                "onTransact",
74                "(IL" PACKAGE_PATH "/HwParcel;L" PACKAGE_PATH "/HwParcel;I)V");
75}
76
77// static
78sp<JHwBinder> JHwBinder::SetNativeContext(
79        JNIEnv *env, jobject thiz, const sp<JHwBinder> &context) {
80    sp<JHwBinder> old =
81        (JHwBinder *)env->GetLongField(thiz, gFields.contextID);
82
83    if (context != NULL) {
84        context->incStrong(NULL /* id */);
85    }
86
87    if (old != NULL) {
88        old->decStrong(NULL /* id */);
89    }
90
91    env->SetLongField(thiz, gFields.contextID, (long)context.get());
92
93    return old;
94}
95
96// static
97sp<JHwBinder> JHwBinder::GetNativeContext(
98        JNIEnv *env, jobject thiz) {
99    return (JHwBinder *)env->GetLongField(thiz, gFields.contextID);
100}
101
102JHwBinder::JHwBinder(JNIEnv *env, jobject thiz) {
103    jclass clazz = env->GetObjectClass(thiz);
104    CHECK(clazz != NULL);
105
106    mClass = (jclass)env->NewGlobalRef(clazz);
107    mObject = env->NewWeakGlobalRef(thiz);
108}
109
110JHwBinder::~JHwBinder() {
111    JNIEnv *env = AndroidRuntime::getJNIEnv();
112
113    env->DeleteWeakGlobalRef(mObject);
114    mObject = NULL;
115
116    env->DeleteGlobalRef(mClass);
117    mClass = NULL;
118}
119
120status_t JHwBinder::onTransact(
121        uint32_t code,
122        const hardware::Parcel &data,
123        hardware::Parcel *reply,
124        uint32_t flags,
125        TransactCallback callback) {
126    JNIEnv *env = AndroidRuntime::getJNIEnv();
127    bool isOneway = (flags & TF_ONE_WAY) != 0;
128    ScopedLocalRef<jobject> replyObj(env, nullptr);
129    sp<JHwParcel> replyContext = nullptr;
130
131    ScopedLocalRef<jobject> requestObj(env, JHwParcel::NewObject(env));
132    JHwParcel::GetNativeContext(env, requestObj.get())->setParcel(
133            const_cast<hardware::Parcel *>(&data), false /* assumeOwnership */);
134
135
136    if (!isOneway) {
137        replyObj.reset(JHwParcel::NewObject(env));
138
139        replyContext = JHwParcel::GetNativeContext(env, replyObj.get());
140
141        replyContext->setParcel(reply, false /* assumeOwnership */);
142        replyContext->setTransactCallback(callback);
143    }
144
145    env->CallVoidMethod(
146            mObject,
147            gFields.onTransactID,
148            code,
149            requestObj.get(),
150            replyObj.get(),
151            flags);
152
153    if (env->ExceptionCheck()) {
154        jthrowable excep = env->ExceptionOccurred();
155        env->ExceptionDescribe();
156        env->ExceptionClear();
157
158        // It is illegal to call IsInstanceOf if there is a pending exception.
159        // Attempting to do so results in a JniAbort which crashes the entire process.
160        if (env->IsInstanceOf(excep, gErrorClass)) {
161            /* It's an error */
162            LOG(ERROR) << "Forcefully exiting";
163            exit(1);
164        } else {
165            LOG(ERROR) << "Uncaught exception!";
166        }
167
168        env->DeleteLocalRef(excep);
169    }
170
171    status_t err = OK;
172
173    if (!isOneway) {
174        if (!replyContext->wasSent()) {
175            // The implementation never finished the transaction.
176            err = UNKNOWN_ERROR;  // XXX special error code instead?
177
178            reply->setDataPosition(0 /* pos */);
179        }
180
181        // Release all temporary storage now that scatter-gather data
182        // has been consolidated, either by calling the TransactCallback,
183        // if wasSent() == true or clearing the reply parcel (setDataOffset above).
184        replyContext->getStorage()->release(env);
185
186        // We cannot permanently pass ownership of "data" and "reply" over to their
187        // Java object wrappers (we don't own them ourselves).
188        replyContext->setParcel(
189                NULL /* parcel */, false /* assumeOwnership */);
190
191    }
192
193    JHwParcel::GetNativeContext(env, requestObj.get())->setParcel(
194            NULL /* parcel */, false /* assumeOwnership */);
195
196    return err;
197}
198
199}  // namespace android
200
201////////////////////////////////////////////////////////////////////////////////
202
203using namespace android;
204
205static void releaseNativeContext(void *nativeContext) {
206    sp<JHwBinder> binder = (JHwBinder *)nativeContext;
207
208    if (binder != NULL) {
209        binder->decStrong(NULL /* id */);
210    }
211}
212
213static jlong JHwBinder_native_init(JNIEnv *env) {
214    JHwBinder::InitClass(env);
215
216    return reinterpret_cast<jlong>(&releaseNativeContext);
217}
218
219static void JHwBinder_native_setup(JNIEnv *env, jobject thiz) {
220    sp<JHwBinder> context = new JHwBinder(env, thiz);
221
222    JHwBinder::SetNativeContext(env, thiz, context);
223}
224
225static void JHwBinder_native_transact(
226        JNIEnv * /* env */,
227        jobject /* thiz */,
228        jint /* code */,
229        jobject /* requestObj */,
230        jobject /* replyObj */,
231        jint /* flags */) {
232    CHECK(!"Should not be here");
233}
234
235static void JHwBinder_native_registerService(
236        JNIEnv *env,
237        jobject thiz,
238        jstring serviceNameObj) {
239    if (serviceNameObj == NULL) {
240        jniThrowException(env, "java/lang/NullPointerException", NULL);
241        return;
242    }
243
244    const char *serviceName = env->GetStringUTFChars(serviceNameObj, NULL);
245    if (serviceName == NULL) {
246        return;  // XXX exception already pending?
247    }
248
249    sp<hardware::IBinder> binder = JHwBinder::GetNativeContext(env, thiz);
250
251    /* TODO(b/33440494) this is not right */
252    sp<hidl::base::V1_0::IBase> base = new hidl::base::V1_0::BpHwBase(binder);
253
254    auto manager = hardware::defaultServiceManager();
255
256    if (manager == nullptr) {
257        LOG(ERROR) << "Could not get hwservicemanager.";
258        signalExceptionForError(env, UNKNOWN_ERROR, true /* canThrowRemoteException */);
259        return;
260    }
261
262    Return<bool> ret = manager->add(serviceName, base);
263
264    env->ReleaseStringUTFChars(serviceNameObj, serviceName);
265    serviceName = NULL;
266
267    bool ok = ret.isOk() && ret;
268
269    if (ok) {
270        LOG(INFO) << "Starting thread pool.";
271        ::android::hardware::ProcessState::self()->startThreadPool();
272    }
273
274    signalExceptionForError(env, (ok ? OK : UNKNOWN_ERROR), true /* canThrowRemoteException */);
275}
276
277static jobject JHwBinder_native_getService(
278        JNIEnv *env,
279        jclass /* clazzObj */,
280        jstring ifaceNameObj,
281        jstring serviceNameObj) {
282
283    using ::android::hidl::base::V1_0::IBase;
284    using ::android::hidl::manager::V1_0::IServiceManager;
285
286    if (ifaceNameObj == NULL) {
287        jniThrowException(env, "java/lang/NullPointerException", NULL);
288        return NULL;
289    }
290    if (serviceNameObj == NULL) {
291        jniThrowException(env, "java/lang/NullPointerException", NULL);
292        return NULL;
293    }
294
295    auto manager = hardware::defaultServiceManager();
296
297    if (manager == nullptr) {
298        LOG(ERROR) << "Could not get hwservicemanager.";
299        signalExceptionForError(env, UNKNOWN_ERROR, true /* canThrowRemoteException */);
300        return NULL;
301    }
302
303    const char *ifaceNameCStr = env->GetStringUTFChars(ifaceNameObj, NULL);
304    if (ifaceNameCStr == NULL) {
305        return NULL; // XXX exception already pending?
306    }
307    std::string ifaceName(ifaceNameCStr);
308    env->ReleaseStringUTFChars(ifaceNameObj, ifaceNameCStr);
309    ::android::hardware::hidl_string ifaceNameHStr;
310    ifaceNameHStr.setToExternal(ifaceName.c_str(), ifaceName.size());
311
312    const char *serviceNameCStr = env->GetStringUTFChars(serviceNameObj, NULL);
313    if (serviceNameCStr == NULL) {
314        return NULL; // XXX exception already pending?
315    }
316    std::string serviceName(serviceNameCStr);
317    env->ReleaseStringUTFChars(serviceNameObj, serviceNameCStr);
318    ::android::hardware::hidl_string serviceNameHStr;
319    serviceNameHStr.setToExternal(serviceName.c_str(), serviceName.size());
320
321    LOG(INFO) << "Looking for service "
322              << ifaceName
323              << "/"
324              << serviceName;
325
326    Return<IServiceManager::Transport> transportRet =
327            manager->getTransport(ifaceNameHStr, serviceNameHStr);
328
329    if (!transportRet.isOk()) {
330        signalExceptionForError(env, UNKNOWN_ERROR, true /* canThrowRemoteException */);
331        return NULL;
332    }
333
334    IServiceManager::Transport transport = transportRet;
335
336#ifdef __ANDROID_TREBLE__
337#ifdef __ANDROID_DEBUGGABLE__
338    const char* testingOverride = std::getenv("TREBLE_TESTING_OVERRIDE");
339    const bool vintfLegacy = (transport == IServiceManager::Transport::EMPTY)
340            && testingOverride && !strcmp(testingOverride, "true");
341#else // __ANDROID_TREBLE__ but not __ANDROID_DEBUGGABLE__
342    const bool vintfLegacy = false;
343#endif // __ANDROID_DEBUGGABLE__
344#else // not __ANDROID_TREBLE__
345    const bool vintfLegacy = (transport == IServiceManager::Transport::EMPTY);
346#endif // __ANDROID_TREBLE__";
347
348    if (transport != IServiceManager::Transport::HWBINDER && !vintfLegacy) {
349        LOG(ERROR) << "service " << ifaceName << " declares transport method "
350                   << toString(transport) << " but framework expects hwbinder.";
351        signalExceptionForError(env, UNKNOWN_ERROR, true /* canThrowRemoteException */);
352        return NULL;
353    }
354
355    Return<sp<hidl::base::V1_0::IBase>> ret = manager->get(ifaceNameHStr, serviceNameHStr);
356
357    if (!ret.isOk()) {
358        signalExceptionForError(env, UNKNOWN_ERROR, true /* canThrowRemoteException */);
359        return NULL;
360    }
361
362    sp<hardware::IBinder> service = hardware::toBinder<
363            hidl::base::V1_0::IBase, hidl::base::V1_0::BpHwBase>(ret);
364
365    if (service == NULL) {
366        signalExceptionForError(env, NAME_NOT_FOUND);
367        return NULL;
368    }
369
370    LOG(INFO) << "Starting thread pool.";
371    ::android::hardware::ProcessState::self()->startThreadPool();
372
373    return JHwRemoteBinder::NewObject(env, service);
374}
375
376static JNINativeMethod gMethods[] = {
377    { "native_init", "()J", (void *)JHwBinder_native_init },
378    { "native_setup", "()V", (void *)JHwBinder_native_setup },
379
380    { "transact",
381        "(IL" PACKAGE_PATH "/HwParcel;L" PACKAGE_PATH "/HwParcel;I)V",
382        (void *)JHwBinder_native_transact },
383
384    { "registerService", "(Ljava/lang/String;)V",
385        (void *)JHwBinder_native_registerService },
386
387    { "getService", "(Ljava/lang/String;Ljava/lang/String;)L" PACKAGE_PATH "/IHwBinder;",
388        (void *)JHwBinder_native_getService },
389};
390
391namespace android {
392
393int register_android_os_HwBinder(JNIEnv *env) {
394    jclass errorClass = FindClassOrDie(env, "java/lang/Error");
395    gErrorClass = MakeGlobalRefOrDie(env, errorClass);
396
397    return RegisterMethodsOrDie(env, CLASS_PATH, gMethods, NELEM(gMethods));
398}
399
400}  // namespace android
401