android_os_HwBinder.cpp revision 85d12da977d575a7461867a732084d64488d1502 
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 <JNIHelp.h>
27#include <android/hidl/manager/1.0/IServiceManager.h>
28#include <android/hidl/base/1.0/IBase.h>
29#include <android/hidl/base/1.0/BpHwBase.h>
30#include <android_runtime/AndroidRuntime.h>
31#include <hidl/ServiceManagement.h>
32#include <hidl/Status.h>
33#include <hidl/HidlTransportSupport.h>
34#include <hwbinder/ProcessState.h>
35#include <nativehelper/ScopedLocalRef.h>
36#include <vintf/parse_string.h>
37
38#include "core_jni_helpers.h"
39
40using android::AndroidRuntime;
41using android::hardware::hidl_vec;
42using android::hardware::hidl_string;
43template<typename T>
44using Return = android::hardware::Return<T>;
45
46#define PACKAGE_PATH    "android/os"
47#define CLASS_NAME      "HwBinder"
48#define CLASS_PATH      PACKAGE_PATH "/" CLASS_NAME
49
50namespace android {
51
52static jclass gErrorClass;
53
54static struct fields_t {
55    jfieldID contextID;
56    jmethodID onTransactID;
57} gFields;
58
59// static
60void JHwBinder::InitClass(JNIEnv *env) {
61    ScopedLocalRef<jclass> clazz(
62            env, FindClassOrDie(env, CLASS_PATH));
63
64    gFields.contextID =
65        GetFieldIDOrDie(env, clazz.get(), "mNativeContext", "J");
66
67    gFields.onTransactID =
68        GetMethodIDOrDie(
69                env,
70                clazz.get(),
71                "onTransact",
72                "(IL" PACKAGE_PATH "/HwParcel;L" PACKAGE_PATH "/HwParcel;I)V");
73}
74
75// static
76sp<JHwBinder> JHwBinder::SetNativeContext(
77        JNIEnv *env, jobject thiz, const sp<JHwBinder> &context) {
78    sp<JHwBinder> old =
79        (JHwBinder *)env->GetLongField(thiz, gFields.contextID);
80
81    if (context != NULL) {
82        context->incStrong(NULL /* id */);
83    }
84
85    if (old != NULL) {
86        old->decStrong(NULL /* id */);
87    }
88
89    env->SetLongField(thiz, gFields.contextID, (long)context.get());
90
91    return old;
92}
93
94// static
95sp<JHwBinder> JHwBinder::GetNativeContext(
96        JNIEnv *env, jobject thiz) {
97    return (JHwBinder *)env->GetLongField(thiz, gFields.contextID);
98}
99
100JHwBinder::JHwBinder(JNIEnv *env, jobject thiz) {
101    jclass clazz = env->GetObjectClass(thiz);
102    CHECK(clazz != NULL);
103
104    mClass = (jclass)env->NewGlobalRef(clazz);
105    mObject = env->NewWeakGlobalRef(thiz);
106}
107
108JHwBinder::~JHwBinder() {
109    JNIEnv *env = AndroidRuntime::getJNIEnv();
110
111    env->DeleteWeakGlobalRef(mObject);
112    mObject = NULL;
113
114    env->DeleteGlobalRef(mClass);
115    mClass = NULL;
116}
117
118status_t JHwBinder::onTransact(
119        uint32_t code,
120        const hardware::Parcel &data,
121        hardware::Parcel *reply,
122        uint32_t flags,
123        TransactCallback callback) {
124    JNIEnv *env = AndroidRuntime::getJNIEnv();
125    bool isOneway = (flags & TF_ONE_WAY) != 0;
126    ScopedLocalRef<jobject> replyObj(env, nullptr);
127    sp<JHwParcel> replyContext = nullptr;
128
129    ScopedLocalRef<jobject> requestObj(env, JHwParcel::NewObject(env));
130    JHwParcel::GetNativeContext(env, requestObj.get())->setParcel(
131            const_cast<hardware::Parcel *>(&data), false /* assumeOwnership */);
132
133
134    if (!isOneway) {
135        replyObj.reset(JHwParcel::NewObject(env));
136
137        replyContext = JHwParcel::GetNativeContext(env, replyObj.get());
138
139        replyContext->setParcel(reply, false /* assumeOwnership */);
140        replyContext->setTransactCallback(callback);
141    }
142
143    env->CallVoidMethod(
144            mObject,
145            gFields.onTransactID,
146            code,
147            requestObj.get(),
148            replyObj.get(),
149            flags);
150
151    if (env->ExceptionCheck()) {
152        jthrowable excep = env->ExceptionOccurred();
153        env->ExceptionDescribe();
154
155        if (env->IsInstanceOf(excep, gErrorClass)) {
156            /* It's an error */
157            LOG(ERROR) << "Forcefully exiting";
158            exit(1);
159        } else {
160            env->ExceptionClear();
161            LOG(ERROR) << "Uncaught exception!";
162        }
163
164        env->DeleteLocalRef(excep);
165    }
166
167    status_t err = OK;
168
169    if (!isOneway) {
170        if (!replyContext->wasSent()) {
171            // The implementation never finished the transaction.
172            err = UNKNOWN_ERROR;  // XXX special error code instead?
173
174            reply->setDataPosition(0 /* pos */);
175        }
176
177        // Release all temporary storage now that scatter-gather data
178        // has been consolidated, either by calling the TransactCallback,
179        // if wasSent() == true or clearing the reply parcel (setDataOffset above).
180        replyContext->getStorage()->release(env);
181
182        // We cannot permanently pass ownership of "data" and "reply" over to their
183        // Java object wrappers (we don't own them ourselves).
184        replyContext->setParcel(
185                NULL /* parcel */, false /* assumeOwnership */);
186
187    }
188
189    JHwParcel::GetNativeContext(env, requestObj.get())->setParcel(
190            NULL /* parcel */, false /* assumeOwnership */);
191
192    return err;
193}
194
195}  // namespace android
196
197////////////////////////////////////////////////////////////////////////////////
198
199using namespace android;
200
201static void releaseNativeContext(void *nativeContext) {
202    sp<JHwBinder> binder = (JHwBinder *)nativeContext;
203
204    if (binder != NULL) {
205        binder->decStrong(NULL /* id */);
206    }
207}
208
209static jlong JHwBinder_native_init(JNIEnv *env) {
210    JHwBinder::InitClass(env);
211
212    return reinterpret_cast<jlong>(&releaseNativeContext);
213}
214
215static void JHwBinder_native_setup(JNIEnv *env, jobject thiz) {
216    sp<JHwBinder> context = new JHwBinder(env, thiz);
217
218    JHwBinder::SetNativeContext(env, thiz, context);
219}
220
221static void JHwBinder_native_transact(
222        JNIEnv * /* env */,
223        jobject /* thiz */,
224        jint /* code */,
225        jobject /* requestObj */,
226        jobject /* replyObj */,
227        jint /* flags */) {
228    CHECK(!"Should not be here");
229}
230
231static void JHwBinder_native_registerService(
232        JNIEnv *env,
233        jobject thiz,
234        jstring serviceNameObj) {
235    if (serviceNameObj == NULL) {
236        jniThrowException(env, "java/lang/NullPointerException", NULL);
237        return;
238    }
239
240    const char *serviceName = env->GetStringUTFChars(serviceNameObj, NULL);
241    if (serviceName == NULL) {
242        return;  // XXX exception already pending?
243    }
244
245    sp<hardware::IBinder> binder = JHwBinder::GetNativeContext(env, thiz);
246
247    /* TODO(b/33440494) this is not right */
248    sp<hidl::base::V1_0::IBase> base = new hidl::base::V1_0::BpHwBase(binder);
249
250    auto manager = hardware::defaultServiceManager();
251
252    if (manager == nullptr) {
253        LOG(ERROR) << "Could not get hwservicemanager.";
254        signalExceptionForError(env, UNKNOWN_ERROR, true /* canThrowRemoteException */);
255        return;
256    }
257
258    Return<bool> ret = manager->add(serviceName, base);
259
260    env->ReleaseStringUTFChars(serviceNameObj, serviceName);
261    serviceName = NULL;
262
263    bool ok = ret.isOk() && ret;
264
265    if (ok) {
266        LOG(INFO) << "Starting thread pool.";
267        ::android::hardware::ProcessState::self()->startThreadPool();
268    }
269
270    signalExceptionForError(env, (ok ? OK : UNKNOWN_ERROR), true /* canThrowRemoteException */);
271}
272
273static jobject JHwBinder_native_getService(
274        JNIEnv *env,
275        jclass /* clazzObj */,
276        jstring ifaceNameObj,
277        jstring serviceNameObj) {
278
279    using ::android::vintf::operator<<;
280
281    if (ifaceNameObj == NULL) {
282        jniThrowException(env, "java/lang/NullPointerException", NULL);
283        return NULL;
284    }
285    if (serviceNameObj == NULL) {
286        jniThrowException(env, "java/lang/NullPointerException", NULL);
287        return NULL;
288    }
289
290    auto manager = hardware::defaultServiceManager();
291
292    if (manager == nullptr) {
293        LOG(ERROR) << "Could not get hwservicemanager.";
294        signalExceptionForError(env, UNKNOWN_ERROR, true /* canThrowRemoteException */);
295        return NULL;
296    }
297
298    const char *ifaceNameCStr = env->GetStringUTFChars(ifaceNameObj, NULL);
299    if (ifaceNameCStr == NULL) {
300        return NULL; // XXX exception already pending?
301    }
302    std::string ifaceName(ifaceNameCStr);
303    env->ReleaseStringUTFChars(ifaceNameObj, ifaceNameCStr);
304    ::android::hardware::hidl_string ifaceNameHStr;
305    ifaceNameHStr.setToExternal(ifaceName.c_str(), ifaceName.size());
306
307    const char *serviceNameCStr = env->GetStringUTFChars(serviceNameObj, NULL);
308    if (serviceNameCStr == NULL) {
309        return NULL; // XXX exception already pending?
310    }
311    std::string serviceName(serviceNameCStr);
312    env->ReleaseStringUTFChars(serviceNameObj, serviceNameCStr);
313    ::android::hardware::hidl_string serviceNameHStr;
314    serviceNameHStr.setToExternal(serviceName.c_str(), serviceName.size());
315
316    LOG(INFO) << "Looking for service "
317              << ifaceName
318              << "/"
319              << serviceName;
320
321    ::android::vintf::Transport transport =
322            ::android::hardware::getTransport(ifaceName, serviceName);
323    if (   transport != ::android::vintf::Transport::EMPTY
324        && transport != ::android::vintf::Transport::HWBINDER) {
325        LOG(ERROR) << "service " << ifaceName << " declares transport method "
326                   << transport << " but framework expects "
327                   << ::android::vintf::Transport::HWBINDER;
328        signalExceptionForError(env, UNKNOWN_ERROR, true /* canThrowRemoteException */);
329        return NULL;
330    }
331
332    Return<sp<hidl::base::V1_0::IBase>> ret = manager->get(ifaceNameHStr, serviceNameHStr);
333
334    if (!ret.isOk()) {
335        signalExceptionForError(env, UNKNOWN_ERROR, true /* canThrowRemoteException */);
336        return NULL;
337    }
338
339    sp<hardware::IBinder> service = hardware::toBinder<
340            hidl::base::V1_0::IBase, hidl::base::V1_0::BpHwBase>(ret);
341
342    if (service == NULL) {
343        signalExceptionForError(env, NAME_NOT_FOUND);
344        return NULL;
345    }
346
347    LOG(INFO) << "Starting thread pool.";
348    ::android::hardware::ProcessState::self()->startThreadPool();
349
350    return JHwRemoteBinder::NewObject(env, service);
351}
352
353static JNINativeMethod gMethods[] = {
354    { "native_init", "()J", (void *)JHwBinder_native_init },
355    { "native_setup", "()V", (void *)JHwBinder_native_setup },
356
357    { "transact",
358        "(IL" PACKAGE_PATH "/HwParcel;L" PACKAGE_PATH "/HwParcel;I)V",
359        (void *)JHwBinder_native_transact },
360
361    { "registerService", "(Ljava/lang/String;)V",
362        (void *)JHwBinder_native_registerService },
363
364    { "getService", "(Ljava/lang/String;Ljava/lang/String;)L" PACKAGE_PATH "/IHwBinder;",
365        (void *)JHwBinder_native_getService },
366};
367
368namespace android {
369
370int register_android_os_HwBinder(JNIEnv *env) {
371    jclass errorClass = FindClassOrDie(env, "java/lang/Error");
372    gErrorClass = MakeGlobalRefOrDie(env, errorClass);
373
374    return RegisterMethodsOrDie(env, CLASS_PATH, gMethods, NELEM(gMethods));
375}
376
377}  // namespace android
378