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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     // can only attach once
51     CHECK_EQ(nullptr, binder->attachObject(kId, kValue, nullptr /*cookie*/, clean));
52 }
has(const sp<IBinder> & binder)53 static bool has(const sp<IBinder>& binder) {
54     return binder != nullptr && binder->findObject(kId) == kValue;
55 }
56 
57 }  // namespace ABBinderTag
58 
59 namespace ABpBinderTag {
60 
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                        << clazz << " vs " << mClazz << "). 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 
107 // b/175635923 libcxx causes "implicit-conversion" with a string with invalid char
SanitizeString(const String16 & str)108 static std::string SanitizeString(const String16& str) {
109     std::string sanitized{String8(str)};
110     for (auto& c : sanitized) {
111         if (!isprint(c)) {
112             c = '?';
113         }
114     }
115     return sanitized;
116 }
117 
associateClass(const AIBinder_Class * clazz)118 bool AIBinder::associateClass(const AIBinder_Class* clazz) {
119     if (clazz == nullptr) return false;
120 
121     const String16& newDescriptor = clazz->getInterfaceDescriptor();
122 
123     auto result = associateClassInternal(clazz, newDescriptor, false);
124     if (result.has_value()) return *result;
125 
126     CHECK(asABpBinder() != nullptr);  // ABBinder always has a descriptor
127 
128     const String16& descriptor = getBinder()->getInterfaceDescriptor();
129     if (descriptor != newDescriptor) {
130         if (getBinder()->isBinderAlive()) {
131             LOG(ERROR) << __func__ << ": Expecting binder to have class '" << newDescriptor
132                        << "' but descriptor is actually '" << SanitizeString(descriptor) << "'.";
133         } else {
134             // b/155793159
135             LOG(ERROR) << __func__ << ": Cannot associate class '" << newDescriptor
136                        << "' to dead binder.";
137         }
138         return false;
139     }
140 
141     return associateClassInternal(clazz, newDescriptor, true).value();
142 }
143 
ABBinder(const AIBinder_Class * clazz,void * userData)144 ABBinder::ABBinder(const AIBinder_Class* clazz, void* userData)
145     : AIBinder(clazz), BBinder(), mUserData(userData) {
146     CHECK(clazz != nullptr);
147 }
~ABBinder()148 ABBinder::~ABBinder() {
149     getClass()->onDestroy(mUserData);
150 }
151 
getInterfaceDescriptor() const152 const String16& ABBinder::getInterfaceDescriptor() const {
153     return getClass()->getInterfaceDescriptor();
154 }
155 
dump(int fd,const::android::Vector<String16> & args)156 status_t ABBinder::dump(int fd, const ::android::Vector<String16>& args) {
157     AIBinder_onDump onDump = getClass()->onDump;
158 
159     if (onDump == nullptr) {
160         return STATUS_OK;
161     }
162 
163     // technically UINT32_MAX would be okay here, but INT32_MAX is expected since this may be
164     // null in Java
165     if (args.size() > INT32_MAX) {
166         LOG(ERROR) << "ABBinder::dump received too many arguments: " << args.size();
167         return STATUS_BAD_VALUE;
168     }
169 
170     std::vector<String8> utf8Args;  // owns memory of utf8s
171     utf8Args.reserve(args.size());
172     std::vector<const char*> utf8Pointers;  // what can be passed over NDK API
173     utf8Pointers.reserve(args.size());
174 
175     for (size_t i = 0; i < args.size(); i++) {
176         utf8Args.push_back(String8(args[i]));
177         utf8Pointers.push_back(utf8Args[i].c_str());
178     }
179 
180     return onDump(this, fd, utf8Pointers.data(), utf8Pointers.size());
181 }
182 
onTransact(transaction_code_t code,const Parcel & data,Parcel * reply,binder_flags_t flags)183 status_t ABBinder::onTransact(transaction_code_t code, const Parcel& data, Parcel* reply,
184                               binder_flags_t flags) {
185     if (isUserCommand(code)) {
186         if (getClass()->writeHeader && !data.checkInterface(this)) {
187             return STATUS_BAD_TYPE;
188         }
189 
190         const AParcel in = AParcel::readOnly(this, &data);
191         AParcel out = AParcel(this, reply, false /*owns*/);
192 
193         binder_status_t status = getClass()->onTransact(this, code, &in, &out);
194         return PruneStatusT(status);
195     } else if (code == SHELL_COMMAND_TRANSACTION && getClass()->handleShellCommand != nullptr) {
196         int in = data.readFileDescriptor();
197         int out = data.readFileDescriptor();
198         int err = data.readFileDescriptor();
199 
200         int argc = data.readInt32();
201         std::vector<String8> utf8Args;          // owns memory of utf8s
202         std::vector<const char*> utf8Pointers;  // what can be passed over NDK API
203         for (int i = 0; i < argc && data.dataAvail() > 0; i++) {
204             utf8Args.push_back(String8(data.readString16()));
205             utf8Pointers.push_back(utf8Args[i].c_str());
206         }
207 
208         data.readStrongBinder();  // skip over the IShellCallback
209         sp<IResultReceiver> resultReceiver = IResultReceiver::asInterface(data.readStrongBinder());
210 
211         // Shell commands should only be callable by ADB.
212         uid_t uid = AIBinder_getCallingUid();
213         if (uid != AID_ROOT && uid != AID_SHELL) {
214             if (resultReceiver != nullptr) {
215                 resultReceiver->send(-1);
216             }
217             return STATUS_PERMISSION_DENIED;
218         }
219 
220         // Check that the file descriptors are valid.
221         if (in == STATUS_BAD_TYPE || out == STATUS_BAD_TYPE || err == STATUS_BAD_TYPE) {
222             if (resultReceiver != nullptr) {
223                 resultReceiver->send(-1);
224             }
225             return STATUS_BAD_VALUE;
226         }
227 
228         binder_status_t status = getClass()->handleShellCommand(
229                 this, in, out, err, utf8Pointers.data(), utf8Pointers.size());
230         if (resultReceiver != nullptr) {
231             resultReceiver->send(status);
232         }
233         return status;
234     } else {
235         return BBinder::onTransact(code, data, reply, flags);
236     }
237 }
238 
ABpBinder(const::android::sp<::android::IBinder> & binder)239 ABpBinder::ABpBinder(const ::android::sp<::android::IBinder>& binder)
240     : AIBinder(nullptr /*clazz*/), BpRefBase(binder) {
241     CHECK(binder != nullptr);
242 }
~ABpBinder()243 ABpBinder::~ABpBinder() {}
244 
onLastStrongRef(const void * id)245 void ABpBinder::onLastStrongRef(const void* id) {
246     // Since ABpBinder is OBJECT_LIFETIME_WEAK, we must remove this weak reference in order for
247     // the ABpBinder to be deleted. Even though we have no more references on the ABpBinder
248     // (BpRefBase), the remote object may still exist (for instance, if we
249     // receive it from another process, before the ABpBinder is attached).
250 
251     ABpBinderTag::Value* value =
252             static_cast<ABpBinderTag::Value*>(remote()->findObject(ABpBinderTag::kId));
253     CHECK_NE(nullptr, value) << "ABpBinder must always be attached";
254 
255     remote()->withLock([&]() { value->binder = nullptr; });
256 
257     BpRefBase::onLastStrongRef(id);
258 }
259 
lookupOrCreateFromBinder(const::android::sp<::android::IBinder> & binder)260 sp<AIBinder> ABpBinder::lookupOrCreateFromBinder(const ::android::sp<::android::IBinder>& binder) {
261     if (binder == nullptr) {
262         return nullptr;
263     }
264     if (ABBinderTag::has(binder)) {
265         return static_cast<ABBinder*>(binder.get());
266     }
267 
268     // The following code ensures that for a given binder object (remote or local), if it is not an
269     // ABBinder then at most one ABpBinder object exists in a given process representing it.
270 
271     auto* value = static_cast<ABpBinderTag::Value*>(binder->findObject(ABpBinderTag::kId));
272     if (value == nullptr) {
273         value = new ABpBinderTag::Value;
274         auto oldValue = static_cast<ABpBinderTag::Value*>(
275                 binder->attachObject(ABpBinderTag::kId, static_cast<void*>(value),
276                                      nullptr /*cookie*/, ABpBinderTag::clean));
277 
278         // allocated by another thread
279         if (oldValue) {
280             delete value;
281             value = oldValue;
282         }
283     }
284 
285     sp<ABpBinder> ret;
286     binder->withLock([&]() {
287         ret = value->binder.promote();
288         if (ret == nullptr) {
289             ret = sp<ABpBinder>::make(binder);
290             value->binder = ret;
291         }
292     });
293 
294     return ret;
295 }
296 
297 struct AIBinder_Weak {
298     wp<AIBinder> binder;
299 };
AIBinder_Weak_new(AIBinder * binder)300 AIBinder_Weak* AIBinder_Weak_new(AIBinder* binder) {
301     if (binder == nullptr) {
302         return nullptr;
303     }
304 
305     return new AIBinder_Weak{wp<AIBinder>(binder)};
306 }
AIBinder_Weak_delete(AIBinder_Weak * weakBinder)307 void AIBinder_Weak_delete(AIBinder_Weak* weakBinder) {
308     delete weakBinder;
309 }
AIBinder_Weak_promote(AIBinder_Weak * weakBinder)310 AIBinder* AIBinder_Weak_promote(AIBinder_Weak* weakBinder) {
311     if (weakBinder == nullptr) {
312         return nullptr;
313     }
314 
315     sp<AIBinder> binder = weakBinder->binder.promote();
316     AIBinder_incStrong(binder.get());
317     return binder.get();
318 }
319 
AIBinder_Weak_clone(const AIBinder_Weak * weak)320 AIBinder_Weak* AIBinder_Weak_clone(const AIBinder_Weak* weak) {
321     if (weak == nullptr) {
322         return nullptr;
323     }
324 
325     return new AIBinder_Weak{weak->binder};
326 }
327 
AIBinder_lt(const AIBinder * lhs,const AIBinder * rhs)328 bool AIBinder_lt(const AIBinder* lhs, const AIBinder* rhs) {
329     if (lhs == nullptr || rhs == nullptr) return lhs < rhs;
330 
331     return const_cast<AIBinder*>(lhs)->getBinder() < const_cast<AIBinder*>(rhs)->getBinder();
332 }
333 
AIBinder_Weak_lt(const AIBinder_Weak * lhs,const AIBinder_Weak * rhs)334 bool AIBinder_Weak_lt(const AIBinder_Weak* lhs, const AIBinder_Weak* rhs) {
335     if (lhs == nullptr || rhs == nullptr) return lhs < rhs;
336 
337     return lhs->binder < rhs->binder;
338 }
339 
AIBinder_Class(const char * interfaceDescriptor,AIBinder_Class_onCreate onCreate,AIBinder_Class_onDestroy onDestroy,AIBinder_Class_onTransact onTransact)340 AIBinder_Class::AIBinder_Class(const char* interfaceDescriptor, AIBinder_Class_onCreate onCreate,
341                                AIBinder_Class_onDestroy onDestroy,
342                                AIBinder_Class_onTransact onTransact)
343     : onCreate(onCreate),
344       onDestroy(onDestroy),
345       onTransact(onTransact),
346       mInterfaceDescriptor(interfaceDescriptor),
347       mWideInterfaceDescriptor(interfaceDescriptor) {}
348 
AIBinder_Class_define(const char * interfaceDescriptor,AIBinder_Class_onCreate onCreate,AIBinder_Class_onDestroy onDestroy,AIBinder_Class_onTransact onTransact)349 AIBinder_Class* AIBinder_Class_define(const char* interfaceDescriptor,
350                                       AIBinder_Class_onCreate onCreate,
351                                       AIBinder_Class_onDestroy onDestroy,
352                                       AIBinder_Class_onTransact onTransact) {
353     if (interfaceDescriptor == nullptr || onCreate == nullptr || onDestroy == nullptr ||
354         onTransact == nullptr) {
355         return nullptr;
356     }
357 
358     return new AIBinder_Class(interfaceDescriptor, onCreate, onDestroy, onTransact);
359 }
360 
AIBinder_Class_setOnDump(AIBinder_Class * clazz,AIBinder_onDump onDump)361 void AIBinder_Class_setOnDump(AIBinder_Class* clazz, AIBinder_onDump onDump) {
362     CHECK(clazz != nullptr) << "setOnDump requires non-null clazz";
363 
364     // this is required to be called before instances are instantiated
365     clazz->onDump = onDump;
366 }
367 
AIBinder_Class_disableInterfaceTokenHeader(AIBinder_Class * clazz)368 void AIBinder_Class_disableInterfaceTokenHeader(AIBinder_Class* clazz) {
369     CHECK(clazz != nullptr) << "disableInterfaceTokenHeader requires non-null clazz";
370 
371     clazz->writeHeader = false;
372 }
373 
AIBinder_Class_setHandleShellCommand(AIBinder_Class * clazz,AIBinder_handleShellCommand handleShellCommand)374 void AIBinder_Class_setHandleShellCommand(AIBinder_Class* clazz,
375                                           AIBinder_handleShellCommand handleShellCommand) {
376     CHECK(clazz != nullptr) << "setHandleShellCommand requires non-null clazz";
377 
378     clazz->handleShellCommand = handleShellCommand;
379 }
380 
AIBinder_Class_getDescriptor(const AIBinder_Class * clazz)381 const char* AIBinder_Class_getDescriptor(const AIBinder_Class* clazz) {
382     CHECK(clazz != nullptr) << "getDescriptor requires non-null clazz";
383 
384     return clazz->getInterfaceDescriptorUtf8();
385 }
386 
~TransferDeathRecipient()387 AIBinder_DeathRecipient::TransferDeathRecipient::~TransferDeathRecipient() {
388     if (mOnUnlinked != nullptr) {
389         mOnUnlinked(mCookie);
390     }
391 }
392 
binderDied(const wp<IBinder> & who)393 void AIBinder_DeathRecipient::TransferDeathRecipient::binderDied(const wp<IBinder>& who) {
394     CHECK(who == mWho) << who.unsafe_get() << "(" << who.get_refs() << ") vs " << mWho.unsafe_get()
395                        << " (" << mWho.get_refs() << ")";
396 
397     mOnDied(mCookie);
398 
399     sp<AIBinder_DeathRecipient> recipient = mParentRecipient.promote();
400     sp<IBinder> strongWho = who.promote();
401 
402     // otherwise this will be cleaned up later with pruneDeadTransferEntriesLocked
403     if (recipient != nullptr && strongWho != nullptr) {
404         status_t result = recipient->unlinkToDeath(strongWho, mCookie);
405         if (result != ::android::DEAD_OBJECT) {
406             LOG(WARNING) << "Unlinking to dead binder resulted in: " << result;
407         }
408     }
409 
410     mWho = nullptr;
411 }
412 
AIBinder_DeathRecipient(AIBinder_DeathRecipient_onBinderDied onDied)413 AIBinder_DeathRecipient::AIBinder_DeathRecipient(AIBinder_DeathRecipient_onBinderDied onDied)
414     : mOnDied(onDied), mOnUnlinked(nullptr) {
415     CHECK(onDied != nullptr);
416 }
417 
pruneDeadTransferEntriesLocked()418 void AIBinder_DeathRecipient::pruneDeadTransferEntriesLocked() {
419     mDeathRecipients.erase(std::remove_if(mDeathRecipients.begin(), mDeathRecipients.end(),
420                                           [](const sp<TransferDeathRecipient>& tdr) {
421                                               return tdr->getWho() == nullptr;
422                                           }),
423                            mDeathRecipients.end());
424 }
425 
linkToDeath(const sp<IBinder> & binder,void * cookie)426 binder_status_t AIBinder_DeathRecipient::linkToDeath(const sp<IBinder>& binder, void* cookie) {
427     CHECK(binder != nullptr);
428 
429     std::lock_guard<std::mutex> l(mDeathRecipientsMutex);
430 
431     sp<TransferDeathRecipient> recipient =
432             new TransferDeathRecipient(binder, cookie, this, mOnDied, mOnUnlinked);
433 
434     status_t status = binder->linkToDeath(recipient, cookie, 0 /*flags*/);
435     if (status != STATUS_OK) {
436         // When we failed to link, the destructor of TransferDeathRecipient runs here, which
437         // ensures that mOnUnlinked is called before we return with an error from this method.
438         return PruneStatusT(status);
439     }
440 
441     mDeathRecipients.push_back(recipient);
442 
443     pruneDeadTransferEntriesLocked();
444     return STATUS_OK;
445 }
446 
unlinkToDeath(const sp<IBinder> & binder,void * cookie)447 binder_status_t AIBinder_DeathRecipient::unlinkToDeath(const sp<IBinder>& binder, void* cookie) {
448     CHECK(binder != nullptr);
449 
450     std::lock_guard<std::mutex> l(mDeathRecipientsMutex);
451 
452     for (auto it = mDeathRecipients.rbegin(); it != mDeathRecipients.rend(); ++it) {
453         sp<TransferDeathRecipient> recipient = *it;
454 
455         if (recipient->getCookie() == cookie && recipient->getWho() == binder) {
456             mDeathRecipients.erase(it.base() - 1);
457 
458             status_t status = binder->unlinkToDeath(recipient, cookie, 0 /*flags*/);
459             if (status != ::android::OK) {
460                 LOG(ERROR) << __func__
461                            << ": removed reference to death recipient but unlink failed.";
462             }
463             return PruneStatusT(status);
464         }
465     }
466 
467     return STATUS_NAME_NOT_FOUND;
468 }
469 
setOnUnlinked(AIBinder_DeathRecipient_onBinderUnlinked onUnlinked)470 void AIBinder_DeathRecipient::setOnUnlinked(AIBinder_DeathRecipient_onBinderUnlinked onUnlinked) {
471     mOnUnlinked = onUnlinked;
472 }
473 
474 // start of C-API methods
475 
AIBinder_new(const AIBinder_Class * clazz,void * args)476 AIBinder* AIBinder_new(const AIBinder_Class* clazz, void* args) {
477     if (clazz == nullptr) {
478         LOG(ERROR) << __func__ << ": Must provide class to construct local binder.";
479         return nullptr;
480     }
481 
482     void* userData = clazz->onCreate(args);
483 
484     sp<AIBinder> ret = new ABBinder(clazz, userData);
485     ABBinderTag::attach(ret->getBinder());
486 
487     AIBinder_incStrong(ret.get());
488     return ret.get();
489 }
490 
AIBinder_isRemote(const AIBinder * binder)491 bool AIBinder_isRemote(const AIBinder* binder) {
492     if (binder == nullptr) {
493         return false;
494     }
495 
496     return binder->isRemote();
497 }
498 
AIBinder_isAlive(const AIBinder * binder)499 bool AIBinder_isAlive(const AIBinder* binder) {
500     if (binder == nullptr) {
501         return false;
502     }
503 
504     return const_cast<AIBinder*>(binder)->getBinder()->isBinderAlive();
505 }
506 
AIBinder_ping(AIBinder * binder)507 binder_status_t AIBinder_ping(AIBinder* binder) {
508     if (binder == nullptr) {
509         return STATUS_UNEXPECTED_NULL;
510     }
511 
512     return PruneStatusT(binder->getBinder()->pingBinder());
513 }
514 
AIBinder_dump(AIBinder * binder,int fd,const char ** args,uint32_t numArgs)515 binder_status_t AIBinder_dump(AIBinder* binder, int fd, const char** args, uint32_t numArgs) {
516     if (binder == nullptr) {
517         return STATUS_UNEXPECTED_NULL;
518     }
519 
520     ABBinder* bBinder = binder->asABBinder();
521     if (bBinder != nullptr) {
522         AIBinder_onDump onDump = binder->getClass()->onDump;
523         if (onDump == nullptr) {
524             return STATUS_OK;
525         }
526         return PruneStatusT(onDump(bBinder, fd, args, numArgs));
527     }
528 
529     ::android::Vector<String16> utf16Args;
530     utf16Args.setCapacity(numArgs);
531     for (uint32_t i = 0; i < numArgs; i++) {
532         utf16Args.push(String16(String8(args[i])));
533     }
534 
535     status_t status = binder->getBinder()->dump(fd, utf16Args);
536     return PruneStatusT(status);
537 }
538 
AIBinder_linkToDeath(AIBinder * binder,AIBinder_DeathRecipient * recipient,void * cookie)539 binder_status_t AIBinder_linkToDeath(AIBinder* binder, AIBinder_DeathRecipient* recipient,
540                                      void* cookie) {
541     if (binder == nullptr || recipient == nullptr) {
542         LOG(ERROR) << __func__ << ": Must provide binder and recipient.";
543         return STATUS_UNEXPECTED_NULL;
544     }
545 
546     // returns binder_status_t
547     return recipient->linkToDeath(binder->getBinder(), cookie);
548 }
549 
AIBinder_unlinkToDeath(AIBinder * binder,AIBinder_DeathRecipient * recipient,void * cookie)550 binder_status_t AIBinder_unlinkToDeath(AIBinder* binder, AIBinder_DeathRecipient* recipient,
551                                        void* cookie) {
552     if (binder == nullptr || recipient == nullptr) {
553         LOG(ERROR) << __func__ << ": Must provide binder and recipient.";
554         return STATUS_UNEXPECTED_NULL;
555     }
556 
557     // returns binder_status_t
558     return recipient->unlinkToDeath(binder->getBinder(), cookie);
559 }
560 
AIBinder_getCallingUid()561 uid_t AIBinder_getCallingUid() {
562     return ::android::IPCThreadState::self()->getCallingUid();
563 }
564 
AIBinder_getCallingPid()565 pid_t AIBinder_getCallingPid() {
566     return ::android::IPCThreadState::self()->getCallingPid();
567 }
568 
AIBinder_isHandlingTransaction()569 bool AIBinder_isHandlingTransaction() {
570     return ::android::IPCThreadState::self()->getServingStackPointer() != nullptr;
571 }
572 
AIBinder_incStrong(AIBinder * binder)573 void AIBinder_incStrong(AIBinder* binder) {
574     if (binder == nullptr) {
575         return;
576     }
577 
578     binder->incStrong(nullptr);
579 }
AIBinder_decStrong(AIBinder * binder)580 void AIBinder_decStrong(AIBinder* binder) {
581     if (binder == nullptr) {
582         LOG(ERROR) << __func__ << ": on null binder";
583         return;
584     }
585 
586     binder->decStrong(nullptr);
587 }
AIBinder_debugGetRefCount(AIBinder * binder)588 int32_t AIBinder_debugGetRefCount(AIBinder* binder) {
589     if (binder == nullptr) {
590         LOG(ERROR) << __func__ << ": on null binder";
591         return -1;
592     }
593 
594     return binder->getStrongCount();
595 }
596 
AIBinder_associateClass(AIBinder * binder,const AIBinder_Class * clazz)597 bool AIBinder_associateClass(AIBinder* binder, const AIBinder_Class* clazz) {
598     if (binder == nullptr) {
599         return false;
600     }
601 
602     return binder->associateClass(clazz);
603 }
604 
AIBinder_getClass(AIBinder * binder)605 const AIBinder_Class* AIBinder_getClass(AIBinder* binder) {
606     if (binder == nullptr) {
607         return nullptr;
608     }
609 
610     return binder->getClass();
611 }
612 
AIBinder_getUserData(AIBinder * binder)613 void* AIBinder_getUserData(AIBinder* binder) {
614     if (binder == nullptr) {
615         return nullptr;
616     }
617 
618     ABBinder* bBinder = binder->asABBinder();
619     if (bBinder == nullptr) {
620         return nullptr;
621     }
622 
623     return bBinder->getUserData();
624 }
625 
AIBinder_prepareTransaction(AIBinder * binder,AParcel ** in)626 binder_status_t AIBinder_prepareTransaction(AIBinder* binder, AParcel** in) {
627     if (binder == nullptr || in == nullptr) {
628         LOG(ERROR) << __func__ << ": requires non-null parameters.";
629         return STATUS_UNEXPECTED_NULL;
630     }
631     const AIBinder_Class* clazz = binder->getClass();
632     if (clazz == nullptr) {
633         LOG(ERROR) << __func__
634                    << ": Class must be defined for a remote binder transaction. See "
635                       "AIBinder_associateClass.";
636         return STATUS_INVALID_OPERATION;
637     }
638 
639     *in = new AParcel(binder);
640     (*in)->get()->markForBinder(binder->getBinder());
641 
642     status_t status = android::OK;
643     if (clazz->writeHeader) {
644         status = (*in)->get()->writeInterfaceToken(clazz->getInterfaceDescriptor());
645     }
646     binder_status_t ret = PruneStatusT(status);
647 
648     if (ret != STATUS_OK) {
649         delete *in;
650         *in = nullptr;
651     }
652 
653     return ret;
654 }
655 
DestroyParcel(AParcel ** parcel)656 static void DestroyParcel(AParcel** parcel) {
657     delete *parcel;
658     *parcel = nullptr;
659 }
660 
AIBinder_transact(AIBinder * binder,transaction_code_t code,AParcel ** in,AParcel ** out,binder_flags_t flags)661 binder_status_t AIBinder_transact(AIBinder* binder, transaction_code_t code, AParcel** in,
662                                   AParcel** out, binder_flags_t flags) {
663     if (in == nullptr) {
664         LOG(ERROR) << __func__ << ": requires non-null in parameter";
665         return STATUS_UNEXPECTED_NULL;
666     }
667 
668     using AutoParcelDestroyer = std::unique_ptr<AParcel*, void (*)(AParcel**)>;
669     // This object is the input to the transaction. This function takes ownership of it and deletes
670     // it.
671     AutoParcelDestroyer forIn(in, DestroyParcel);
672 
673     if (!isUserCommand(code)) {
674         LOG(ERROR) << __func__ << ": Only user-defined transactions can be made from the NDK.";
675         return STATUS_UNKNOWN_TRANSACTION;
676     }
677 
678     constexpr binder_flags_t kAllFlags = FLAG_PRIVATE_VENDOR | FLAG_ONEWAY | FLAG_CLEAR_BUF;
679     if ((flags & ~kAllFlags) != 0) {
680         LOG(ERROR) << __func__ << ": Unrecognized flags sent: " << flags;
681         return STATUS_BAD_VALUE;
682     }
683 
684     if (binder == nullptr || *in == nullptr || out == nullptr) {
685         LOG(ERROR) << __func__ << ": requires non-null parameters.";
686         return STATUS_UNEXPECTED_NULL;
687     }
688 
689     if ((*in)->getBinder() != binder) {
690         LOG(ERROR) << __func__ << ": parcel is associated with binder object " << binder
691                    << " but called with " << (*in)->getBinder();
692         return STATUS_BAD_VALUE;
693     }
694 
695     *out = new AParcel(binder);
696 
697     status_t status = binder->getBinder()->transact(code, *(*in)->get(), (*out)->get(), flags);
698     binder_status_t ret = PruneStatusT(status);
699 
700     if (ret != STATUS_OK) {
701         delete *out;
702         *out = nullptr;
703     }
704 
705     return ret;
706 }
707 
AIBinder_DeathRecipient_new(AIBinder_DeathRecipient_onBinderDied onBinderDied)708 AIBinder_DeathRecipient* AIBinder_DeathRecipient_new(
709         AIBinder_DeathRecipient_onBinderDied onBinderDied) {
710     if (onBinderDied == nullptr) {
711         LOG(ERROR) << __func__ << ": requires non-null onBinderDied parameter.";
712         return nullptr;
713     }
714     auto ret = new AIBinder_DeathRecipient(onBinderDied);
715     ret->incStrong(nullptr);
716     return ret;
717 }
718 
AIBinder_DeathRecipient_setOnUnlinked(AIBinder_DeathRecipient * recipient,AIBinder_DeathRecipient_onBinderUnlinked onUnlinked)719 void AIBinder_DeathRecipient_setOnUnlinked(AIBinder_DeathRecipient* recipient,
720                                            AIBinder_DeathRecipient_onBinderUnlinked onUnlinked) {
721     if (recipient == nullptr) {
722         return;
723     }
724 
725     recipient->setOnUnlinked(onUnlinked);
726 }
727 
AIBinder_DeathRecipient_delete(AIBinder_DeathRecipient * recipient)728 void AIBinder_DeathRecipient_delete(AIBinder_DeathRecipient* recipient) {
729     if (recipient == nullptr) {
730         return;
731     }
732 
733     recipient->decStrong(nullptr);
734 }
735 
AIBinder_getExtension(AIBinder * binder,AIBinder ** outExt)736 binder_status_t AIBinder_getExtension(AIBinder* binder, AIBinder** outExt) {
737     if (binder == nullptr || outExt == nullptr) {
738         if (outExt != nullptr) {
739             *outExt = nullptr;
740         }
741         return STATUS_UNEXPECTED_NULL;
742     }
743 
744     sp<IBinder> ext;
745     status_t res = binder->getBinder()->getExtension(&ext);
746 
747     if (res != android::OK) {
748         *outExt = nullptr;
749         return PruneStatusT(res);
750     }
751 
752     sp<AIBinder> ret = ABpBinder::lookupOrCreateFromBinder(ext);
753     if (ret != nullptr) ret->incStrong(binder);
754 
755     *outExt = ret.get();
756     return STATUS_OK;
757 }
758 
AIBinder_setExtension(AIBinder * binder,AIBinder * ext)759 binder_status_t AIBinder_setExtension(AIBinder* binder, AIBinder* ext) {
760     if (binder == nullptr || ext == nullptr) {
761         return STATUS_UNEXPECTED_NULL;
762     }
763 
764     ABBinder* rawBinder = binder->asABBinder();
765     if (rawBinder == nullptr) {
766         return STATUS_INVALID_OPERATION;
767     }
768 
769     rawBinder->setExtension(ext->getBinder());
770     return STATUS_OK;
771 }
772 
773 // platform methods follow
774 
AIBinder_setRequestingSid(AIBinder * binder,bool requestingSid)775 void AIBinder_setRequestingSid(AIBinder* binder, bool requestingSid) {
776     ABBinder* localBinder = binder->asABBinder();
777     if (localBinder == nullptr) {
778         LOG(FATAL) << "AIBinder_setRequestingSid must be called on a local binder";
779     }
780 
781     localBinder->setRequestingSid(requestingSid);
782 }
783 
AIBinder_getCallingSid()784 const char* AIBinder_getCallingSid() {
785     return ::android::IPCThreadState::self()->getCallingSid();
786 }
787 
AIBinder_toPlatformBinder(AIBinder * binder)788 android::sp<android::IBinder> AIBinder_toPlatformBinder(AIBinder* binder) {
789     if (binder == nullptr) return nullptr;
790     return binder->getBinder();
791 }
792 
AIBinder_fromPlatformBinder(const android::sp<android::IBinder> & binder)793 AIBinder* AIBinder_fromPlatformBinder(const android::sp<android::IBinder>& binder) {
794     sp<AIBinder> ndkBinder = ABpBinder::lookupOrCreateFromBinder(binder);
795     AIBinder_incStrong(ndkBinder.get());
796     return ndkBinder.get();
797 }
798 
AIBinder_setMinSchedulerPolicy(AIBinder * binder,int policy,int priority)799 void AIBinder_setMinSchedulerPolicy(AIBinder* binder, int policy, int priority) {
800     binder->asABBinder()->setMinSchedulerPolicy(policy, priority);
801 }
802 
AIBinder_setInheritRt(AIBinder * binder,bool inheritRt)803 void AIBinder_setInheritRt(AIBinder* binder, bool inheritRt) {
804     ABBinder* localBinder = binder->asABBinder();
805     if (localBinder == nullptr) {
806         LOG(FATAL) << "AIBinder_setInheritRt must be called on a local binder";
807     }
808 
809     localBinder->setInheritRt(inheritRt);
810 }
811