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1 /*
2  * Copyright (C) 2018 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 <android/binder_ibinder.h>
18 #include <android/binder_ibinder_platform.h>
19 #include <android/binder_libbinder.h>
20 #include "ibinder_internal.h"
21 
22 #include <android/binder_stability.h>
23 #include <android/binder_status.h>
24 #include "parcel_internal.h"
25 #include "status_internal.h"
26 
27 #include <android-base/logging.h>
28 #include <binder/IPCThreadState.h>
29 #include <binder/IResultReceiver.h>
30 #include <private/android_filesystem_config.h>
31 
32 using DeathRecipient = ::android::IBinder::DeathRecipient;
33 
34 using ::android::IBinder;
35 using ::android::IResultReceiver;
36 using ::android::Parcel;
37 using ::android::sp;
38 using ::android::status_t;
39 using ::android::String16;
40 using ::android::String8;
41 using ::android::wp;
42 
43 namespace ABBinderTag {
44 
45 static const void* kId = "ABBinder";
46 static void* kValue = static_cast<void*>(new bool{true});
clean(const void *,void *,void *)47 void clean(const void* /*id*/, void* /*obj*/, void* /*cookie*/){/* do nothing */};
48 
attach(const sp<IBinder> & binder)49 static void attach(const sp<IBinder>& binder) {
50     binder->attachObject(kId, kValue, nullptr /*cookie*/, clean);
51 }
has(const sp<IBinder> & binder)52 static bool has(const sp<IBinder>& binder) {
53     return binder != nullptr && binder->findObject(kId) == kValue;
54 }
55 
56 }  // namespace ABBinderTag
57 
58 namespace ABpBinderTag {
59 
60 static std::mutex gLock;
61 static const void* kId = "ABpBinder";
62 struct Value {
63     wp<ABpBinder> binder;
64 };
clean(const void * id,void * obj,void * cookie)65 void clean(const void* id, void* obj, void* cookie) {
66     CHECK(id == kId) << id << " " << obj << " " << cookie;
67 
68     delete static_cast<Value*>(obj);
69 };
70 
71 }  // namespace ABpBinderTag
72 
AIBinder(const AIBinder_Class * clazz)73 AIBinder::AIBinder(const AIBinder_Class* clazz) : mClazz(clazz) {}
~AIBinder()74 AIBinder::~AIBinder() {}
75 
associateClassInternal(const AIBinder_Class * clazz,const String16 & newDescriptor,bool set)76 std::optional<bool> AIBinder::associateClassInternal(const AIBinder_Class* clazz,
77                                                      const String16& newDescriptor, bool set) {
78     std::lock_guard<std::mutex> lock(mClazzMutex);
79     if (mClazz == clazz) return true;
80 
81     if (mClazz != nullptr) {
82         const String16& currentDescriptor = mClazz->getInterfaceDescriptor();
83         if (newDescriptor == currentDescriptor) {
84             LOG(ERROR) << __func__ << ": Class descriptors '" << currentDescriptor
85                        << "' match during associateClass, but they are different class objects. "
86                           "Class descriptor collision?";
87         } else {
88             LOG(ERROR) << __func__
89                        << ": Class cannot be associated on object which already has a class. "
90                           "Trying to associate to '"
91                        << newDescriptor << "' but already set to '" << currentDescriptor << "'.";
92         }
93 
94         // always a failure because we know mClazz != clazz
95         return false;
96     }
97 
98     if (set) {
99         // if this is a local object, it's not one known to libbinder_ndk
100         mClazz = clazz;
101         return true;
102     }
103 
104     return {};
105 }
106 
associateClass(const AIBinder_Class * clazz)107 bool AIBinder::associateClass(const AIBinder_Class* clazz) {
108     if (clazz == nullptr) return false;
109 
110     const String16& newDescriptor = clazz->getInterfaceDescriptor();
111 
112     auto result = associateClassInternal(clazz, newDescriptor, false);
113     if (result.has_value()) return *result;
114 
115     CHECK(asABpBinder() != nullptr);  // ABBinder always has a descriptor
116 
117     const String16& descriptor = getBinder()->getInterfaceDescriptor();
118     if (descriptor != newDescriptor) {
119         if (getBinder()->isBinderAlive()) {
120             LOG(ERROR) << __func__ << ": Expecting binder to have class '" << newDescriptor
121                        << "' but descriptor is actually '" << descriptor << "'.";
122         } else {
123             // b/155793159
124             LOG(ERROR) << __func__ << ": Cannot associate class '" << newDescriptor
125                        << "' to dead binder.";
126         }
127         return false;
128     }
129 
130     return associateClassInternal(clazz, newDescriptor, true).value();
131 }
132 
ABBinder(const AIBinder_Class * clazz,void * userData)133 ABBinder::ABBinder(const AIBinder_Class* clazz, void* userData)
134     : AIBinder(clazz), BBinder(), mUserData(userData) {
135     CHECK(clazz != nullptr);
136 }
~ABBinder()137 ABBinder::~ABBinder() {
138     getClass()->onDestroy(mUserData);
139 }
140 
getInterfaceDescriptor() const141 const String16& ABBinder::getInterfaceDescriptor() const {
142     return getClass()->getInterfaceDescriptor();
143 }
144 
dump(int fd,const::android::Vector<String16> & args)145 status_t ABBinder::dump(int fd, const ::android::Vector<String16>& args) {
146     AIBinder_onDump onDump = getClass()->onDump;
147 
148     if (onDump == nullptr) {
149         return STATUS_OK;
150     }
151 
152     // technically UINT32_MAX would be okay here, but INT32_MAX is expected since this may be
153     // null in Java
154     if (args.size() > INT32_MAX) {
155         LOG(ERROR) << "ABBinder::dump received too many arguments: " << args.size();
156         return STATUS_BAD_VALUE;
157     }
158 
159     std::vector<String8> utf8Args;  // owns memory of utf8s
160     utf8Args.reserve(args.size());
161     std::vector<const char*> utf8Pointers;  // what can be passed over NDK API
162     utf8Pointers.reserve(args.size());
163 
164     for (size_t i = 0; i < args.size(); i++) {
165         utf8Args.push_back(String8(args[i]));
166         utf8Pointers.push_back(utf8Args[i].c_str());
167     }
168 
169     return onDump(this, fd, utf8Pointers.data(), utf8Pointers.size());
170 }
171 
onTransact(transaction_code_t code,const Parcel & data,Parcel * reply,binder_flags_t flags)172 status_t ABBinder::onTransact(transaction_code_t code, const Parcel& data, Parcel* reply,
173                               binder_flags_t flags) {
174     if (isUserCommand(code)) {
175         if (!data.checkInterface(this)) {
176             return STATUS_BAD_TYPE;
177         }
178 
179         const AParcel in = AParcel::readOnly(this, &data);
180         AParcel out = AParcel(this, reply, false /*owns*/);
181 
182         binder_status_t status = getClass()->onTransact(this, code, &in, &out);
183         return PruneStatusT(status);
184     } else if (code == SHELL_COMMAND_TRANSACTION && getClass()->handleShellCommand != nullptr) {
185         int in = data.readFileDescriptor();
186         int out = data.readFileDescriptor();
187         int err = data.readFileDescriptor();
188 
189         int argc = data.readInt32();
190         std::vector<String8> utf8Args;          // owns memory of utf8s
191         std::vector<const char*> utf8Pointers;  // what can be passed over NDK API
192         for (int i = 0; i < argc && data.dataAvail() > 0; i++) {
193             utf8Args.push_back(String8(data.readString16()));
194             utf8Pointers.push_back(utf8Args[i].c_str());
195         }
196 
197         data.readStrongBinder();  // skip over the IShellCallback
198         sp<IResultReceiver> resultReceiver = IResultReceiver::asInterface(data.readStrongBinder());
199 
200         // Shell commands should only be callable by ADB.
201         uid_t uid = AIBinder_getCallingUid();
202         if (uid != AID_ROOT && uid != AID_SHELL) {
203             if (resultReceiver != nullptr) {
204                 resultReceiver->send(-1);
205             }
206             return STATUS_PERMISSION_DENIED;
207         }
208 
209         // Check that the file descriptors are valid.
210         if (in == STATUS_BAD_TYPE || out == STATUS_BAD_TYPE || err == STATUS_BAD_TYPE) {
211             if (resultReceiver != nullptr) {
212                 resultReceiver->send(-1);
213             }
214             return STATUS_BAD_VALUE;
215         }
216 
217         binder_status_t status = getClass()->handleShellCommand(
218                 this, in, out, err, utf8Pointers.data(), utf8Pointers.size());
219         if (resultReceiver != nullptr) {
220             resultReceiver->send(status);
221         }
222         return status;
223     } else {
224         return BBinder::onTransact(code, data, reply, flags);
225     }
226 }
227 
ABpBinder(const::android::sp<::android::IBinder> & binder)228 ABpBinder::ABpBinder(const ::android::sp<::android::IBinder>& binder)
229     : AIBinder(nullptr /*clazz*/), BpRefBase(binder) {
230     CHECK(binder != nullptr);
231 }
~ABpBinder()232 ABpBinder::~ABpBinder() {}
233 
onLastStrongRef(const void * id)234 void ABpBinder::onLastStrongRef(const void* id) {
235     {
236         std::lock_guard<std::mutex> lock(ABpBinderTag::gLock);
237         // Since ABpBinder is OBJECT_LIFETIME_WEAK, we must remove this weak reference in order for
238         // the ABpBinder to be deleted. Since a strong reference to this ABpBinder object should no
239         // longer be able to exist at the time of this method call, there is no longer a need to
240         // recover it.
241 
242         ABpBinderTag::Value* value =
243                 static_cast<ABpBinderTag::Value*>(remote()->findObject(ABpBinderTag::kId));
244         if (value != nullptr) {
245             value->binder = nullptr;
246         }
247     }
248 
249     BpRefBase::onLastStrongRef(id);
250 }
251 
lookupOrCreateFromBinder(const::android::sp<::android::IBinder> & binder)252 sp<AIBinder> ABpBinder::lookupOrCreateFromBinder(const ::android::sp<::android::IBinder>& binder) {
253     if (binder == nullptr) {
254         return nullptr;
255     }
256     if (ABBinderTag::has(binder)) {
257         return static_cast<ABBinder*>(binder.get());
258     }
259 
260     // The following code ensures that for a given binder object (remote or local), if it is not an
261     // ABBinder then at most one ABpBinder object exists in a given process representing it.
262     std::lock_guard<std::mutex> lock(ABpBinderTag::gLock);
263 
264     ABpBinderTag::Value* value =
265             static_cast<ABpBinderTag::Value*>(binder->findObject(ABpBinderTag::kId));
266     if (value == nullptr) {
267         value = new ABpBinderTag::Value;
268         binder->attachObject(ABpBinderTag::kId, static_cast<void*>(value), nullptr /*cookie*/,
269                              ABpBinderTag::clean);
270     }
271 
272     sp<ABpBinder> ret = value->binder.promote();
273     if (ret == nullptr) {
274         ret = new ABpBinder(binder);
275         value->binder = ret;
276     }
277 
278     return ret;
279 }
280 
281 struct AIBinder_Weak {
282     wp<AIBinder> binder;
283 };
AIBinder_Weak_new(AIBinder * binder)284 AIBinder_Weak* AIBinder_Weak_new(AIBinder* binder) {
285     if (binder == nullptr) {
286         return nullptr;
287     }
288 
289     return new AIBinder_Weak{wp<AIBinder>(binder)};
290 }
AIBinder_Weak_delete(AIBinder_Weak * weakBinder)291 void AIBinder_Weak_delete(AIBinder_Weak* weakBinder) {
292     delete weakBinder;
293 }
AIBinder_Weak_promote(AIBinder_Weak * weakBinder)294 AIBinder* AIBinder_Weak_promote(AIBinder_Weak* weakBinder) {
295     if (weakBinder == nullptr) {
296         return nullptr;
297     }
298 
299     sp<AIBinder> binder = weakBinder->binder.promote();
300     AIBinder_incStrong(binder.get());
301     return binder.get();
302 }
303 
AIBinder_Weak_clone(const AIBinder_Weak * weak)304 AIBinder_Weak* AIBinder_Weak_clone(const AIBinder_Weak* weak) {
305     if (weak == nullptr) {
306         return nullptr;
307     }
308 
309     return new AIBinder_Weak{weak->binder};
310 }
311 
AIBinder_lt(const AIBinder * lhs,const AIBinder * rhs)312 bool AIBinder_lt(const AIBinder* lhs, const AIBinder* rhs) {
313     if (lhs == nullptr || rhs == nullptr) return lhs < rhs;
314 
315     return const_cast<AIBinder*>(lhs)->getBinder() < const_cast<AIBinder*>(rhs)->getBinder();
316 }
317 
AIBinder_Weak_lt(const AIBinder_Weak * lhs,const AIBinder_Weak * rhs)318 bool AIBinder_Weak_lt(const AIBinder_Weak* lhs, const AIBinder_Weak* rhs) {
319     if (lhs == nullptr || rhs == nullptr) return lhs < rhs;
320 
321     return lhs->binder < rhs->binder;
322 }
323 
AIBinder_Class(const char * interfaceDescriptor,AIBinder_Class_onCreate onCreate,AIBinder_Class_onDestroy onDestroy,AIBinder_Class_onTransact onTransact)324 AIBinder_Class::AIBinder_Class(const char* interfaceDescriptor, AIBinder_Class_onCreate onCreate,
325                                AIBinder_Class_onDestroy onDestroy,
326                                AIBinder_Class_onTransact onTransact)
327     : onCreate(onCreate),
328       onDestroy(onDestroy),
329       onTransact(onTransact),
330       mInterfaceDescriptor(interfaceDescriptor),
331       mWideInterfaceDescriptor(interfaceDescriptor) {}
332 
AIBinder_Class_define(const char * interfaceDescriptor,AIBinder_Class_onCreate onCreate,AIBinder_Class_onDestroy onDestroy,AIBinder_Class_onTransact onTransact)333 AIBinder_Class* AIBinder_Class_define(const char* interfaceDescriptor,
334                                       AIBinder_Class_onCreate onCreate,
335                                       AIBinder_Class_onDestroy onDestroy,
336                                       AIBinder_Class_onTransact onTransact) {
337     if (interfaceDescriptor == nullptr || onCreate == nullptr || onDestroy == nullptr ||
338         onTransact == nullptr) {
339         return nullptr;
340     }
341 
342     return new AIBinder_Class(interfaceDescriptor, onCreate, onDestroy, onTransact);
343 }
344 
AIBinder_Class_setOnDump(AIBinder_Class * clazz,AIBinder_onDump onDump)345 void AIBinder_Class_setOnDump(AIBinder_Class* clazz, AIBinder_onDump onDump) {
346     CHECK(clazz != nullptr) << "setOnDump requires non-null clazz";
347 
348     // this is required to be called before instances are instantiated
349     clazz->onDump = onDump;
350 }
351 
AIBinder_Class_setHandleShellCommand(AIBinder_Class * clazz,AIBinder_handleShellCommand handleShellCommand)352 void AIBinder_Class_setHandleShellCommand(AIBinder_Class* clazz,
353                                           AIBinder_handleShellCommand handleShellCommand) {
354     CHECK(clazz != nullptr) << "setHandleShellCommand requires non-null clazz";
355 
356     clazz->handleShellCommand = handleShellCommand;
357 }
358 
AIBinder_Class_getDescriptor(const AIBinder_Class * clazz)359 const char* AIBinder_Class_getDescriptor(const AIBinder_Class* clazz) {
360     CHECK(clazz != nullptr) << "getDescriptor requires non-null clazz";
361 
362     return clazz->getInterfaceDescriptorUtf8();
363 }
364 
binderDied(const wp<IBinder> & who)365 void AIBinder_DeathRecipient::TransferDeathRecipient::binderDied(const wp<IBinder>& who) {
366     CHECK(who == mWho) << who.unsafe_get() << "(" << who.get_refs() << ") vs " << mWho.unsafe_get()
367                        << " (" << mWho.get_refs() << ")";
368 
369     mOnDied(mCookie);
370 
371     sp<AIBinder_DeathRecipient> recipient = mParentRecipient.promote();
372     sp<IBinder> strongWho = who.promote();
373 
374     // otherwise this will be cleaned up later with pruneDeadTransferEntriesLocked
375     if (recipient != nullptr && strongWho != nullptr) {
376         status_t result = recipient->unlinkToDeath(strongWho, mCookie);
377         if (result != ::android::DEAD_OBJECT) {
378             LOG(WARNING) << "Unlinking to dead binder resulted in: " << result;
379         }
380     }
381 
382     mWho = nullptr;
383 }
384 
AIBinder_DeathRecipient(AIBinder_DeathRecipient_onBinderDied onDied)385 AIBinder_DeathRecipient::AIBinder_DeathRecipient(AIBinder_DeathRecipient_onBinderDied onDied)
386     : mOnDied(onDied) {
387     CHECK(onDied != nullptr);
388 }
389 
pruneDeadTransferEntriesLocked()390 void AIBinder_DeathRecipient::pruneDeadTransferEntriesLocked() {
391     mDeathRecipients.erase(std::remove_if(mDeathRecipients.begin(), mDeathRecipients.end(),
392                                           [](const sp<TransferDeathRecipient>& tdr) {
393                                               return tdr->getWho() == nullptr;
394                                           }),
395                            mDeathRecipients.end());
396 }
397 
linkToDeath(const sp<IBinder> & binder,void * cookie)398 binder_status_t AIBinder_DeathRecipient::linkToDeath(const sp<IBinder>& binder, void* cookie) {
399     CHECK(binder != nullptr);
400 
401     std::lock_guard<std::mutex> l(mDeathRecipientsMutex);
402 
403     sp<TransferDeathRecipient> recipient =
404             new TransferDeathRecipient(binder, cookie, this, mOnDied);
405 
406     status_t status = binder->linkToDeath(recipient, cookie, 0 /*flags*/);
407     if (status != STATUS_OK) {
408         return PruneStatusT(status);
409     }
410 
411     mDeathRecipients.push_back(recipient);
412 
413     pruneDeadTransferEntriesLocked();
414     return STATUS_OK;
415 }
416 
unlinkToDeath(const sp<IBinder> & binder,void * cookie)417 binder_status_t AIBinder_DeathRecipient::unlinkToDeath(const sp<IBinder>& binder, void* cookie) {
418     CHECK(binder != nullptr);
419 
420     std::lock_guard<std::mutex> l(mDeathRecipientsMutex);
421 
422     for (auto it = mDeathRecipients.rbegin(); it != mDeathRecipients.rend(); ++it) {
423         sp<TransferDeathRecipient> recipient = *it;
424 
425         if (recipient->getCookie() == cookie && recipient->getWho() == binder) {
426             mDeathRecipients.erase(it.base() - 1);
427 
428             status_t status = binder->unlinkToDeath(recipient, cookie, 0 /*flags*/);
429             if (status != ::android::OK) {
430                 LOG(ERROR) << __func__
431                            << ": removed reference to death recipient but unlink failed.";
432             }
433             return PruneStatusT(status);
434         }
435     }
436 
437     return STATUS_NAME_NOT_FOUND;
438 }
439 
440 // start of C-API methods
441 
AIBinder_new(const AIBinder_Class * clazz,void * args)442 AIBinder* AIBinder_new(const AIBinder_Class* clazz, void* args) {
443     if (clazz == nullptr) {
444         LOG(ERROR) << __func__ << ": Must provide class to construct local binder.";
445         return nullptr;
446     }
447 
448     void* userData = clazz->onCreate(args);
449 
450     sp<AIBinder> ret = new ABBinder(clazz, userData);
451     ABBinderTag::attach(ret->getBinder());
452 
453     AIBinder_incStrong(ret.get());
454     return ret.get();
455 }
456 
AIBinder_isRemote(const AIBinder * binder)457 bool AIBinder_isRemote(const AIBinder* binder) {
458     if (binder == nullptr) {
459         return false;
460     }
461 
462     return binder->isRemote();
463 }
464 
AIBinder_isAlive(const AIBinder * binder)465 bool AIBinder_isAlive(const AIBinder* binder) {
466     if (binder == nullptr) {
467         return false;
468     }
469 
470     return const_cast<AIBinder*>(binder)->getBinder()->isBinderAlive();
471 }
472 
AIBinder_ping(AIBinder * binder)473 binder_status_t AIBinder_ping(AIBinder* binder) {
474     if (binder == nullptr) {
475         return STATUS_UNEXPECTED_NULL;
476     }
477 
478     return PruneStatusT(binder->getBinder()->pingBinder());
479 }
480 
AIBinder_dump(AIBinder * binder,int fd,const char ** args,uint32_t numArgs)481 binder_status_t AIBinder_dump(AIBinder* binder, int fd, const char** args, uint32_t numArgs) {
482     if (binder == nullptr) {
483         return STATUS_UNEXPECTED_NULL;
484     }
485 
486     ABBinder* bBinder = binder->asABBinder();
487     if (bBinder != nullptr) {
488         AIBinder_onDump onDump = binder->getClass()->onDump;
489         if (onDump == nullptr) {
490             return STATUS_OK;
491         }
492         return PruneStatusT(onDump(bBinder, fd, args, numArgs));
493     }
494 
495     ::android::Vector<String16> utf16Args;
496     utf16Args.setCapacity(numArgs);
497     for (uint32_t i = 0; i < numArgs; i++) {
498         utf16Args.push(String16(String8(args[i])));
499     }
500 
501     status_t status = binder->getBinder()->dump(fd, utf16Args);
502     return PruneStatusT(status);
503 }
504 
AIBinder_linkToDeath(AIBinder * binder,AIBinder_DeathRecipient * recipient,void * cookie)505 binder_status_t AIBinder_linkToDeath(AIBinder* binder, AIBinder_DeathRecipient* recipient,
506                                      void* cookie) {
507     if (binder == nullptr || recipient == nullptr) {
508         LOG(ERROR) << __func__ << ": Must provide binder and recipient.";
509         return STATUS_UNEXPECTED_NULL;
510     }
511 
512     // returns binder_status_t
513     return recipient->linkToDeath(binder->getBinder(), cookie);
514 }
515 
AIBinder_unlinkToDeath(AIBinder * binder,AIBinder_DeathRecipient * recipient,void * cookie)516 binder_status_t AIBinder_unlinkToDeath(AIBinder* binder, AIBinder_DeathRecipient* recipient,
517                                        void* cookie) {
518     if (binder == nullptr || recipient == nullptr) {
519         LOG(ERROR) << __func__ << ": Must provide binder and recipient.";
520         return STATUS_UNEXPECTED_NULL;
521     }
522 
523     // returns binder_status_t
524     return recipient->unlinkToDeath(binder->getBinder(), cookie);
525 }
526 
AIBinder_getCallingUid()527 uid_t AIBinder_getCallingUid() {
528     return ::android::IPCThreadState::self()->getCallingUid();
529 }
530 
AIBinder_getCallingPid()531 pid_t AIBinder_getCallingPid() {
532     return ::android::IPCThreadState::self()->getCallingPid();
533 }
534 
AIBinder_incStrong(AIBinder * binder)535 void AIBinder_incStrong(AIBinder* binder) {
536     if (binder == nullptr) {
537         return;
538     }
539 
540     binder->incStrong(nullptr);
541 }
AIBinder_decStrong(AIBinder * binder)542 void AIBinder_decStrong(AIBinder* binder) {
543     if (binder == nullptr) {
544         LOG(ERROR) << __func__ << ": on null binder";
545         return;
546     }
547 
548     binder->decStrong(nullptr);
549 }
AIBinder_debugGetRefCount(AIBinder * binder)550 int32_t AIBinder_debugGetRefCount(AIBinder* binder) {
551     if (binder == nullptr) {
552         LOG(ERROR) << __func__ << ": on null binder";
553         return -1;
554     }
555 
556     return binder->getStrongCount();
557 }
558 
AIBinder_associateClass(AIBinder * binder,const AIBinder_Class * clazz)559 bool AIBinder_associateClass(AIBinder* binder, const AIBinder_Class* clazz) {
560     if (binder == nullptr) {
561         return false;
562     }
563 
564     return binder->associateClass(clazz);
565 }
566 
AIBinder_getClass(AIBinder * binder)567 const AIBinder_Class* AIBinder_getClass(AIBinder* binder) {
568     if (binder == nullptr) {
569         return nullptr;
570     }
571 
572     return binder->getClass();
573 }
574 
AIBinder_getUserData(AIBinder * binder)575 void* AIBinder_getUserData(AIBinder* binder) {
576     if (binder == nullptr) {
577         return nullptr;
578     }
579 
580     ABBinder* bBinder = binder->asABBinder();
581     if (bBinder == nullptr) {
582         return nullptr;
583     }
584 
585     return bBinder->getUserData();
586 }
587 
AIBinder_prepareTransaction(AIBinder * binder,AParcel ** in)588 binder_status_t AIBinder_prepareTransaction(AIBinder* binder, AParcel** in) {
589     if (binder == nullptr || in == nullptr) {
590         LOG(ERROR) << __func__ << ": requires non-null parameters.";
591         return STATUS_UNEXPECTED_NULL;
592     }
593     const AIBinder_Class* clazz = binder->getClass();
594     if (clazz == nullptr) {
595         LOG(ERROR) << __func__
596                    << ": Class must be defined for a remote binder transaction. See "
597                       "AIBinder_associateClass.";
598         return STATUS_INVALID_OPERATION;
599     }
600 
601     *in = new AParcel(binder);
602     (*in)->get()->markForBinder(binder->getBinder());
603 
604     status_t status = (*in)->get()->writeInterfaceToken(clazz->getInterfaceDescriptor());
605     binder_status_t ret = PruneStatusT(status);
606 
607     if (ret != STATUS_OK) {
608         delete *in;
609         *in = nullptr;
610     }
611 
612     return ret;
613 }
614 
DestroyParcel(AParcel ** parcel)615 static void DestroyParcel(AParcel** parcel) {
616     delete *parcel;
617     *parcel = nullptr;
618 }
619 
AIBinder_transact(AIBinder * binder,transaction_code_t code,AParcel ** in,AParcel ** out,binder_flags_t flags)620 binder_status_t AIBinder_transact(AIBinder* binder, transaction_code_t code, AParcel** in,
621                                   AParcel** out, binder_flags_t flags) {
622     if (in == nullptr) {
623         LOG(ERROR) << __func__ << ": requires non-null in parameter";
624         return STATUS_UNEXPECTED_NULL;
625     }
626 
627     using AutoParcelDestroyer = std::unique_ptr<AParcel*, void (*)(AParcel**)>;
628     // This object is the input to the transaction. This function takes ownership of it and deletes
629     // it.
630     AutoParcelDestroyer forIn(in, DestroyParcel);
631 
632     if (!isUserCommand(code)) {
633         LOG(ERROR) << __func__ << ": Only user-defined transactions can be made from the NDK.";
634         return STATUS_UNKNOWN_TRANSACTION;
635     }
636 
637     constexpr binder_flags_t kAllFlags = FLAG_PRIVATE_VENDOR | FLAG_ONEWAY | FLAG_CLEAR_BUF;
638     if ((flags & ~kAllFlags) != 0) {
639         LOG(ERROR) << __func__ << ": Unrecognized flags sent: " << flags;
640         return STATUS_BAD_VALUE;
641     }
642 
643     if (binder == nullptr || *in == nullptr || out == nullptr) {
644         LOG(ERROR) << __func__ << ": requires non-null parameters.";
645         return STATUS_UNEXPECTED_NULL;
646     }
647 
648     if ((*in)->getBinder() != binder) {
649         LOG(ERROR) << __func__ << ": parcel is associated with binder object " << binder
650                    << " but called with " << (*in)->getBinder();
651         return STATUS_BAD_VALUE;
652     }
653 
654     *out = new AParcel(binder);
655 
656     status_t status = binder->getBinder()->transact(code, *(*in)->get(), (*out)->get(), flags);
657     binder_status_t ret = PruneStatusT(status);
658 
659     if (ret != STATUS_OK) {
660         delete *out;
661         *out = nullptr;
662     }
663 
664     return ret;
665 }
666 
AIBinder_DeathRecipient_new(AIBinder_DeathRecipient_onBinderDied onBinderDied)667 AIBinder_DeathRecipient* AIBinder_DeathRecipient_new(
668         AIBinder_DeathRecipient_onBinderDied onBinderDied) {
669     if (onBinderDied == nullptr) {
670         LOG(ERROR) << __func__ << ": requires non-null onBinderDied parameter.";
671         return nullptr;
672     }
673     auto ret = new AIBinder_DeathRecipient(onBinderDied);
674     ret->incStrong(nullptr);
675     return ret;
676 }
677 
AIBinder_DeathRecipient_delete(AIBinder_DeathRecipient * recipient)678 void AIBinder_DeathRecipient_delete(AIBinder_DeathRecipient* recipient) {
679     if (recipient == nullptr) {
680         return;
681     }
682 
683     recipient->decStrong(nullptr);
684 }
685 
AIBinder_getExtension(AIBinder * binder,AIBinder ** outExt)686 binder_status_t AIBinder_getExtension(AIBinder* binder, AIBinder** outExt) {
687     if (binder == nullptr || outExt == nullptr) {
688         if (outExt != nullptr) {
689             *outExt = nullptr;
690         }
691         return STATUS_UNEXPECTED_NULL;
692     }
693 
694     sp<IBinder> ext;
695     status_t res = binder->getBinder()->getExtension(&ext);
696 
697     if (res != android::OK) {
698         *outExt = nullptr;
699         return PruneStatusT(res);
700     }
701 
702     sp<AIBinder> ret = ABpBinder::lookupOrCreateFromBinder(ext);
703     if (ret != nullptr) ret->incStrong(binder);
704 
705     *outExt = ret.get();
706     return STATUS_OK;
707 }
708 
AIBinder_setExtension(AIBinder * binder,AIBinder * ext)709 binder_status_t AIBinder_setExtension(AIBinder* binder, AIBinder* ext) {
710     if (binder == nullptr || ext == nullptr) {
711         return STATUS_UNEXPECTED_NULL;
712     }
713 
714     ABBinder* rawBinder = binder->asABBinder();
715     if (rawBinder == nullptr) {
716         return STATUS_INVALID_OPERATION;
717     }
718 
719     rawBinder->setExtension(ext->getBinder());
720     return STATUS_OK;
721 }
722 
723 // platform methods follow
724 
AIBinder_setRequestingSid(AIBinder * binder,bool requestingSid)725 void AIBinder_setRequestingSid(AIBinder* binder, bool requestingSid) {
726     ABBinder* localBinder = binder->asABBinder();
727     if (localBinder == nullptr) {
728         LOG(FATAL) << "AIBinder_setRequestingSid must be called on a local binder";
729     }
730 
731     localBinder->setRequestingSid(requestingSid);
732 }
733 
AIBinder_getCallingSid()734 const char* AIBinder_getCallingSid() {
735     return ::android::IPCThreadState::self()->getCallingSid();
736 }
737 
AIBinder_toPlatformBinder(AIBinder * binder)738 android::sp<android::IBinder> AIBinder_toPlatformBinder(AIBinder* binder) {
739     if (binder == nullptr) return nullptr;
740     return binder->getBinder();
741 }
742 
AIBinder_fromPlatformBinder(const android::sp<android::IBinder> & binder)743 AIBinder* AIBinder_fromPlatformBinder(const android::sp<android::IBinder>& binder) {
744     sp<AIBinder> ndkBinder = ABpBinder::lookupOrCreateFromBinder(binder);
745     AIBinder_incStrong(ndkBinder.get());
746     return ndkBinder.get();
747 }
748