Introduces mechanism for background rfcomm servers

This change adds a mechanism in the AdapterService which allows it to
register RFCOMM listeners requested by a BluetoothAdapter.
This is so that applications can request the framework to listen for
incoming RFCOMM connections in the background.

Apps can request that the bluetooth manager, via a BluetoothAdapter,
listen on a specific service record, and then transact incoming socket
connections after receiving a notification of availability via a
PendingIntent.

Tag: #feature
Test: Run the CTS Bluetooth Rfcomm Handoff service Test. This requires
two devices.
Bug: 186494155
Ignore-AOSP-First: Need to commit to downstream first in order to
resolve a merge conflict.

Change-Id: Ia0c71969e691e6353f22fe3b7dae4a7500230e03

1 files changed, 32 insertions, 0 deletions

diff --git a/framework/java/android/bluetooth/BluetoothSocket.java b/framework/java/android/bluetooth/BluetoothSocket.java
index 9d58447607..032f9df4f7 100644
--- a/framework/java/android/bluetooth/BluetoothSocket.java
+++ b/framework/java/android/bluetooth/BluetoothSocket.java
@@ -236,6 +236,33 @@ public final class BluetoothSocket implements Closeable {
         mOutputStream = new BluetoothOutputStream(this);
     }
 
+    /**
+     * Creates a BluetoothSocket from a {@link ParcelFileDescriptor}. This is used for when the
+     * underlying mPfd is transferred to a separate process (e.g. over a binder), and the socket
+     * must be reconstructed.
+     * <p>
+     * The socket should already be connected in this case, so {@link #connect()} should not be
+     * called.
+     *
+     * @param pfd is the {@link ParcelFileDescriptor} for an already connected BluetoothSocket
+     * @param device is the remote {@link BluetoothDevice} that this socket is connected to
+     * @param uuid is the service ID that this RFCOMM connection is using
+     * @throws IOException if socket creation fails.
+     */
+    /*package*/ static BluetoothSocket createSocketFromOpenFd(
+            ParcelFileDescriptor pfd, BluetoothDevice device, ParcelUuid uuid) throws IOException {
+        BluetoothSocket bluetoothSocket =
+                new BluetoothSocket(TYPE_RFCOMM, pfd.getFd(), true, true, device, -1, uuid);
+
+        bluetoothSocket.mPfd = pfd;
+        bluetoothSocket.mSocket = new LocalSocket(pfd.getFileDescriptor());
+        bluetoothSocket.mSocketIS = bluetoothSocket.mSocket.getInputStream();
+        bluetoothSocket.mSocketOS = bluetoothSocket.mSocket.getOutputStream();
+        bluetoothSocket.mSocketState = SocketState.CONNECTED;
+
+        return bluetoothSocket;
+    }
+
     private BluetoothSocket(BluetoothSocket s) {
         if (VDBG) Log.d(TAG, "Creating new Private BluetoothSocket of type: " + s.mType);
         mUuid = s.mUuid;
@@ -718,6 +745,11 @@ public final class BluetoothSocket implements Closeable {
         }
     }
 
+    /** @hide */
+    public ParcelFileDescriptor getParcelFileDescriptor() {
+        return mPfd;
+    }
+
     private String convertAddr(final byte[] addr) {
         return String.format(Locale.US, "%02X:%02X:%02X:%02X:%02X:%02X",
                 addr[0], addr[1], addr[2], addr[3], addr[4], addr[5]);