Add new "shell command" feature to Binder objects.

IBinder has a new common interface for sending shell commands
to it.  This can be implemented by system services to provide
a shell interface to the service, without needing to have separate
shell java code.

Also add a new "cmd" command line tool, which invokes the shell
command method on a system service.  This is much like dumpsys,
but for shell commands.

Change-Id: I95dc80c881a28cefb76957ad4d4fd9b3ed9630df
diff --git a/libs/binder/IResultReceiver.cpp b/libs/binder/IResultReceiver.cpp
new file mode 100644
index 0000000..2a22b69
--- /dev/null
+++ b/libs/binder/IResultReceiver.cpp
@@ -0,0 +1,69 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_TAG "ResultReceiver"
+
+#include <binder/IResultReceiver.h>
+
+#include <utils/Log.h>
+#include <binder/Parcel.h>
+#include <utils/String8.h>
+
+#include <private/binder/Static.h>
+
+namespace android {
+
+// ----------------------------------------------------------------------
+
+class BpResultReceiver : public BpInterface<IResultReceiver>
+{
+public:
+    BpResultReceiver(const sp<IBinder>& impl)
+        : BpInterface<IResultReceiver>(impl)
+    {
+    }
+
+    virtual void send(int32_t resultCode) {
+        Parcel data;
+        data.writeInterfaceToken(IResultReceiver::getInterfaceDescriptor());
+        data.writeInt32(resultCode);
+        remote()->transact(OP_SEND, data, NULL, IBinder::FLAG_ONEWAY);
+    }
+};
+
+IMPLEMENT_META_INTERFACE(ResultReceiver, "com.android.internal.os.IResultReceiver");
+
+// ----------------------------------------------------------------------
+
+status_t BnResultReceiver::onTransact(
+    uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags)
+{
+    switch(code) {
+        case OP_SEND: {
+            CHECK_INTERFACE(IResultReceiver, data, reply);
+            int32_t resultCode = data.readInt32();
+            send(resultCode);
+            if (reply != NULL) {
+                reply->writeNoException();
+            }
+            return NO_ERROR;
+        } break;
+        default:
+            return BBinder::onTransact(code, data, reply, flags);
+    }
+}
+
+}; // namespace android