1/*
2 * Copyright (C) 2005 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 <binder/Binder.h>
18
19#include <atomic>
20#include <utils/misc.h>
21#include <binder/BpBinder.h>
22#include <binder/IInterface.h>
23#include <binder/IResultReceiver.h>
24#include <binder/Parcel.h>
25
26#include <stdio.h>
27
28namespace android {
29
30// ---------------------------------------------------------------------------
31
32IBinder::IBinder()
33    : RefBase()
34{
35}
36
37IBinder::~IBinder()
38{
39}
40
41// ---------------------------------------------------------------------------
42
43sp<IInterface>  IBinder::queryLocalInterface(const String16& /*descriptor*/)
44{
45    return NULL;
46}
47
48BBinder* IBinder::localBinder()
49{
50    return NULL;
51}
52
53BpBinder* IBinder::remoteBinder()
54{
55    return NULL;
56}
57
58bool IBinder::checkSubclass(const void* /*subclassID*/) const
59{
60    return false;
61}
62
63
64status_t IBinder::shellCommand(const sp<IBinder>& target, int in, int out, int err,
65    Vector<String16>& args, const sp<IResultReceiver>& resultReceiver)
66{
67    Parcel send;
68    Parcel reply;
69    send.writeFileDescriptor(in);
70    send.writeFileDescriptor(out);
71    send.writeFileDescriptor(err);
72    const size_t numArgs = args.size();
73    send.writeInt32(numArgs);
74    for (size_t i = 0; i < numArgs; i++) {
75        send.writeString16(args[i]);
76    }
77    send.writeStrongBinder(resultReceiver != NULL ? IInterface::asBinder(resultReceiver) : NULL);
78    return target->transact(SHELL_COMMAND_TRANSACTION, send, &reply);
79}
80
81// ---------------------------------------------------------------------------
82
83class BBinder::Extras
84{
85public:
86    Mutex mLock;
87    BpBinder::ObjectManager mObjects;
88};
89
90// ---------------------------------------------------------------------------
91
92BBinder::BBinder() : mExtras(nullptr)
93{
94}
95
96bool BBinder::isBinderAlive() const
97{
98    return true;
99}
100
101status_t BBinder::pingBinder()
102{
103    return NO_ERROR;
104}
105
106const String16& BBinder::getInterfaceDescriptor() const
107{
108    // This is a local static rather than a global static,
109    // to avoid static initializer ordering issues.
110    static String16 sEmptyDescriptor;
111    ALOGW("reached BBinder::getInterfaceDescriptor (this=%p)", this);
112    return sEmptyDescriptor;
113}
114
115status_t BBinder::transact(
116    uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags)
117{
118    data.setDataPosition(0);
119
120    status_t err = NO_ERROR;
121    switch (code) {
122        case PING_TRANSACTION:
123            reply->writeInt32(pingBinder());
124            break;
125        default:
126            err = onTransact(code, data, reply, flags);
127            break;
128    }
129
130    if (reply != NULL) {
131        reply->setDataPosition(0);
132    }
133
134    return err;
135}
136
137status_t BBinder::linkToDeath(
138    const sp<DeathRecipient>& /*recipient*/, void* /*cookie*/,
139    uint32_t /*flags*/)
140{
141    return INVALID_OPERATION;
142}
143
144status_t BBinder::unlinkToDeath(
145    const wp<DeathRecipient>& /*recipient*/, void* /*cookie*/,
146    uint32_t /*flags*/, wp<DeathRecipient>* /*outRecipient*/)
147{
148    return INVALID_OPERATION;
149}
150
151status_t BBinder::dump(int /*fd*/, const Vector<String16>& /*args*/)
152{
153    return NO_ERROR;
154}
155
156void BBinder::attachObject(
157    const void* objectID, void* object, void* cleanupCookie,
158    object_cleanup_func func)
159{
160    Extras* e = mExtras.load(std::memory_order_acquire);
161
162    if (!e) {
163        e = new Extras;
164        Extras* expected = nullptr;
165        if (!mExtras.compare_exchange_strong(expected, e,
166                                             std::memory_order_release,
167                                             std::memory_order_acquire)) {
168            delete e;
169            e = expected;  // Filled in by CAS
170        }
171        if (e == 0) return; // out of memory
172    }
173
174    AutoMutex _l(e->mLock);
175    e->mObjects.attach(objectID, object, cleanupCookie, func);
176}
177
178void* BBinder::findObject(const void* objectID) const
179{
180    Extras* e = mExtras.load(std::memory_order_acquire);
181    if (!e) return NULL;
182
183    AutoMutex _l(e->mLock);
184    return e->mObjects.find(objectID);
185}
186
187void BBinder::detachObject(const void* objectID)
188{
189    Extras* e = mExtras.load(std::memory_order_acquire);
190    if (!e) return;
191
192    AutoMutex _l(e->mLock);
193    e->mObjects.detach(objectID);
194}
195
196BBinder* BBinder::localBinder()
197{
198    return this;
199}
200
201BBinder::~BBinder()
202{
203    Extras* e = mExtras.load(std::memory_order_relaxed);
204    if (e) delete e;
205}
206
207
208status_t BBinder::onTransact(
209    uint32_t code, const Parcel& data, Parcel* reply, uint32_t /*flags*/)
210{
211    switch (code) {
212        case INTERFACE_TRANSACTION:
213            reply->writeString16(getInterfaceDescriptor());
214            return NO_ERROR;
215
216        case DUMP_TRANSACTION: {
217            int fd = data.readFileDescriptor();
218            int argc = data.readInt32();
219            Vector<String16> args;
220            for (int i = 0; i < argc && data.dataAvail() > 0; i++) {
221               args.add(data.readString16());
222            }
223            return dump(fd, args);
224        }
225
226        case SHELL_COMMAND_TRANSACTION: {
227            int in = data.readFileDescriptor();
228            int out = data.readFileDescriptor();
229            int err = data.readFileDescriptor();
230            int argc = data.readInt32();
231            Vector<String16> args;
232            for (int i = 0; i < argc && data.dataAvail() > 0; i++) {
233               args.add(data.readString16());
234            }
235            sp<IResultReceiver> resultReceiver = IResultReceiver::asInterface(
236                    data.readStrongBinder());
237
238            // XXX can't add virtuals until binaries are updated.
239            //return shellCommand(in, out, err, args, resultReceiver);
240            if (resultReceiver != NULL) {
241                resultReceiver->send(INVALID_OPERATION);
242            }
243        }
244
245        case SYSPROPS_TRANSACTION: {
246            report_sysprop_change();
247            return NO_ERROR;
248        }
249
250        default:
251            return UNKNOWN_TRANSACTION;
252    }
253}
254
255// ---------------------------------------------------------------------------
256
257enum {
258    // This is used to transfer ownership of the remote binder from
259    // the BpRefBase object holding it (when it is constructed), to the
260    // owner of the BpRefBase object when it first acquires that BpRefBase.
261    kRemoteAcquired = 0x00000001
262};
263
264BpRefBase::BpRefBase(const sp<IBinder>& o)
265    : mRemote(o.get()), mRefs(NULL), mState(0)
266{
267    extendObjectLifetime(OBJECT_LIFETIME_WEAK);
268
269    if (mRemote) {
270        mRemote->incStrong(this);           // Removed on first IncStrong().
271        mRefs = mRemote->createWeak(this);  // Held for our entire lifetime.
272    }
273}
274
275BpRefBase::~BpRefBase()
276{
277    if (mRemote) {
278        if (!(mState.load(std::memory_order_relaxed)&kRemoteAcquired)) {
279            mRemote->decStrong(this);
280        }
281        mRefs->decWeak(this);
282    }
283}
284
285void BpRefBase::onFirstRef()
286{
287    mState.fetch_or(kRemoteAcquired, std::memory_order_relaxed);
288}
289
290void BpRefBase::onLastStrongRef(const void* /*id*/)
291{
292    if (mRemote) {
293        mRemote->decStrong(this);
294    }
295}
296
297bool BpRefBase::onIncStrongAttempted(uint32_t /*flags*/, const void* /*id*/)
298{
299    return mRemote ? mRefs->attemptIncStrong(this) : false;
300}
301
302// ---------------------------------------------------------------------------
303
304}; // namespace android
305