commit a194c456520b13779d00b313e0e969ba9a030525
author Steven Moreland <smoreland@google.com> Mon Mar 04 16:47:07 2019 -0800
committer Steven Moreland <smoreland@google.com> Tue Mar 05 10:30:04 2019 -0800
tree 932b9198a7bc13f4bb560a1534dfec9a04123cb3
parent e953b04799fbb3ba54431daac49b232b3c30038f

libbinder_ndk: support dump

At the NDK layer:
AIBinder_Class_setOnDump (to implement dump)
AIBinder_dump (to call dump)

At the AIDL layer:
ICInterface::dump(...) to implement and call dump

Bug: 125733384
Test: atest android.binder.cts
Change-Id: I0873ad574bb7a8b9d645c7301fdfa0797e62c834

libs/binder/ndk/ibinder.cpp

diff --git a/libs/binder/ndk/ibinder.cpp b/libs/binder/ndk/ibinder.cpp
index f9c8c8a..bdbc0d3 100644
--- a/libs/binder/ndk/ibinder.cpp
+++ b/libs/binder/ndk/ibinder.cpp
@@ -31,6 +31,7 @@
 using ::android::sp;
 using ::android::status_t;
 using ::android::String16;
+using ::android::String8;
 using ::android::wp;
 
 namespace ABBinderTag {
@@ -67,8 +68,6 @@
 AIBinder::~AIBinder() {}
 
 bool AIBinder::associateClass(const AIBinder_Class* clazz) {
-    using ::android::String8;
-
     if (clazz == nullptr) return false;
     if (mClazz == clazz) return true;
 
@@ -119,6 +118,33 @@
     return getClass()->getInterfaceDescriptor();
 }
 
+status_t ABBinder::dump(int fd, const ::android::Vector<String16>& args) {
+    AIBinder_onDump onDump = getClass()->onDump;
+
+    if (onDump == nullptr) {
+        return STATUS_OK;
+    }
+
+    // technically UINT32_MAX would be okay here, but INT32_MAX is expected since this may be
+    // null in Java
+    if (args.size() > INT32_MAX) {
+        LOG(ERROR) << "ABBinder::dump received too many arguments: " << args.size();
+        return STATUS_BAD_VALUE;
+    }
+
+    std::vector<String8> utf8Args;  // owns memory of utf8s
+    utf8Args.reserve(args.size());
+    std::vector<const char*> utf8Pointers;  // what can be passed over NDK API
+    utf8Pointers.reserve(args.size());
+
+    for (size_t i = 0; i < args.size(); i++) {
+        utf8Args.push_back(String8(args[i]));
+        utf8Pointers.push_back(utf8Args[i].c_str());
+    }
+
+    return onDump(this, fd, utf8Pointers.data(), utf8Pointers.size());
+}
+
 status_t ABBinder::onTransact(transaction_code_t code, const Parcel& data, Parcel* reply,
                               binder_flags_t flags) {
     if (isUserCommand(code)) {
@@ -232,6 +258,13 @@
     return new AIBinder_Class(interfaceDescriptor, onCreate, onDestroy, onTransact);
 }
 
+void AIBinder_Class_setOnDump(AIBinder_Class* clazz, AIBinder_onDump onDump) {
+    CHECK(clazz != nullptr) << "setOnDump requires non-null clazz";
+
+    // this is required to be called before instances are instantiated
+    clazz->onDump = onDump;
+}
+
 void AIBinder_DeathRecipient::TransferDeathRecipient::binderDied(const wp<IBinder>& who) {
     CHECK(who == mWho);
 
@@ -325,6 +358,30 @@
     return PruneStatusT(binder->getBinder()->pingBinder());
 }
 
+binder_status_t AIBinder_dump(AIBinder* binder, int fd, const char** args, uint32_t numArgs) {
+    if (binder == nullptr) {
+        return STATUS_UNEXPECTED_NULL;
+    }
+
+    ABBinder* bBinder = binder->asABBinder();
+    if (bBinder != nullptr) {
+        AIBinder_onDump onDump = binder->getClass()->onDump;
+        if (onDump == nullptr) {
+            return STATUS_OK;
+        }
+        return PruneStatusT(onDump(bBinder, fd, args, numArgs));
+    }
+
+    ::android::Vector<String16> utf16Args;
+    utf16Args.setCapacity(numArgs);
+    for (uint32_t i = 0; i < numArgs; i++) {
+        utf16Args.push(String16(String8(args[i])));
+    }
+
+    status_t status = binder->getBinder()->dump(fd, utf16Args);
+    return PruneStatusT(status);
+}
+
 binder_status_t AIBinder_linkToDeath(AIBinder* binder, AIBinder_DeathRecipient* recipient,
                                      void* cookie) {
     if (binder == nullptr || recipient == nullptr) {