Encourage developers to connect RFCOMM by UUID instead of Channel.

Hide createRfcommSocket(int channel)
Add createRfcommSocketWithServiceRecord(UUID uuid)

Rename listenUsingRfcomm(String,UUID) -> listenUsingRfcommWithServiceRecord(..)

Now we have a complete API for developers to make peer-peer RFCOMM connections
with hard-coding the limited (30) RFCOMM channels, instead using SDP lookup
of an UUID.

This commit addresses two serious bugs:
- Do not throw IOException on accepting an incoming RFCOMM connection with
  BluetoothSocket. This was a regression from commit 24bb9b8af4ff6915
- Workaround failure of bluez to update SDP cache when channel changes by
  trying to use the same RFCOMM channel on the server every time, instead
  of picking server channels randomly. This is a pretty ugly workaround,
  and we are still trying to fix the caching issue - but with this
  workaround we are at least shippable and apps will work at least until
  they start colliding on the 30 RFCOMM channels.

DrNo: eastham
Bug: 2158900
Joke: What did the digital watch say to his mom? "Look mom no hands."
Change-Id: Ia4879943b83afac06b6f1a3f2391cf1628afce7d

6 files changed, 213 insertions, 48 deletions

diff --git a/core/java/android/bluetooth/BluetoothAdapter.java b/core/java/android/bluetooth/BluetoothAdapter.java
index c6a0619..8ce911d 100644
--- a/core/java/android/bluetooth/BluetoothAdapter.java
+++ b/core/java/android/bluetooth/BluetoothAdapter.java
@@ -31,6 +31,7 @@ import java.util.HashSet;
 import java.util.LinkedList;
 import java.util.Random;
 import java.util.Set;
+import java.util.UUID;
 
 /**
  * Represents the local Bluetooth adapter.
@@ -564,8 +565,16 @@ public final class BluetoothAdapter {
     }
 
     /**
-     * Randomly picks RFCOMM channels until none are left.
+     * Picks RFCOMM channels until none are left.
      * Avoids reserved channels.
+     * Ideally we would pick random channels, but in the current implementation
+     * we start with the channel that is the hash of the UUID, and try every
+     * available channel from there. This means that in most cases a given
+     * uuid will use the same channel. This is a workaround for a Bluez SDP
+     * bug where we are not updating the cache when the channel changes for a
+     * uuid.
+     * TODO: Fix the Bluez SDP caching bug, and go back to random channel
+     * selection
      */
     private static class RfcommChannelPicker {
         private static final int[] RESERVED_RFCOMM_CHANNELS =  new int[] {
@@ -579,7 +588,9 @@ public final class BluetoothAdapter {
 
         private final LinkedList<Integer> mChannels;  // local list of channels left to try
 
-        public RfcommChannelPicker() {
+        private final UUID mUuid;
+
+        public RfcommChannelPicker(UUID uuid) {
             synchronized (RfcommChannelPicker.class) {
                 if (sChannels == null) {
                     // lazy initialization of non-reserved rfcomm channels
@@ -594,13 +605,21 @@ public final class BluetoothAdapter {
                 }
                 mChannels = (LinkedList<Integer>)sChannels.clone();
             }
+            mUuid = uuid;
         }
-        /* Returns next random channel, or -1 if we're out */
+        /* Returns next channel, or -1 if we're out */
         public int nextChannel() {
-            if (mChannels.size() == 0) {
-                return -1;
+            int channel = mUuid.hashCode();  // always pick the same channel to try first
+            Integer channelInt;
+            while (mChannels.size() > 0) {
+                channelInt = new Integer(channel);
+                if (mChannels.remove(channelInt)) {
+                    return channel;
+                }
+                channel = (channel % BluetoothSocket.MAX_RFCOMM_CHANNEL) + 1;
             }
-            return mChannels.remove(sRandom.nextInt(mChannels.size()));
+
+            return -1;
         }
     }
 
@@ -644,6 +663,8 @@ public final class BluetoothAdapter {
      * can use the same UUID to query our SDP server and discover which channel
      * to connect to. This SDP record will be removed when this socket is
      * closed, or if this application closes unexpectedly.
+     * <p>Use {@link BluetoothDevice#createRfcommSocketToServiceRecord} to
+     * connect to this socket from another device using the same {@link UUID}.
      * <p>Requires {@link android.Manifest.permission#BLUETOOTH}
      * @param name service name for SDP record
      * @param uuid uuid for SDP record
@@ -651,9 +672,9 @@ public final class BluetoothAdapter {
      * @throws IOException on error, for example Bluetooth not available, or
      *                     insufficient permissions, or channel in use.
      */
-    public BluetoothServerSocket listenUsingRfcomm(String name, ParcelUuid uuid)
+    public BluetoothServerSocket listenUsingRfcommWithServiceRecord(String name, UUID uuid)
             throws IOException {
-        RfcommChannelPicker picker = new RfcommChannelPicker();
+        RfcommChannelPicker picker = new RfcommChannelPicker(uuid);
 
         BluetoothServerSocket socket;
         int channel;
@@ -687,7 +708,8 @@ public final class BluetoothAdapter {
 
         int handle = -1;
         try {
-            handle = mService.addRfcommServiceRecord(name, uuid, channel, new Binder());
+            handle = mService.addRfcommServiceRecord(name, new ParcelUuid(uuid), channel,
+                    new Binder());
         } catch (RemoteException e) {Log.e(TAG, "", e);}
         if (handle == -1) {
             try {
diff --git a/core/java/android/bluetooth/BluetoothDevice.java b/core/java/android/bluetooth/BluetoothDevice.java
index d5393ed..ce975c2 100644
--- a/core/java/android/bluetooth/BluetoothDevice.java
+++ b/core/java/android/bluetooth/BluetoothDevice.java
@@ -316,21 +316,16 @@ public final class BluetoothDevice implements Parcelable {
      */
     public static final String EXTRA_UUID = "android.bluetooth.device.extra.UUID";
 
-
-    private static IBluetooth sService;  /* Guarenteed constant after first object constructed */
+    /**
+     * Lazy initialization. Guaranteed final after first object constructed, or
+     * getService() called.
+     * TODO: Unify implementation of sService amongst BluetoothFoo API's
+     */
+    private static IBluetooth sService;
 
     private final String mAddress;
 
-    /**
-     * Create a new BluetoothDevice
-     * Bluetooth MAC address must be upper case, such as "00:11:22:33:AA:BB",
-     * and is validated in this constructor.
-     * @param address valid Bluetooth MAC address
-     * @throws RuntimeException Bluetooth is not available on this platform
-     * @throws IllegalArgumentException address is invalid
-     * @hide
-     */
-    /*package*/ BluetoothDevice(String address) {
+    /*package*/ static IBluetooth getService() {
         synchronized (BluetoothDevice.class) {
             if (sService == null) {
                 IBinder b = ServiceManager.getService(Context.BLUETOOTH_SERVICE);
@@ -340,7 +335,20 @@ public final class BluetoothDevice implements Parcelable {
                 sService = IBluetooth.Stub.asInterface(b);
             }
         }
+        return sService;
+    }
 
+    /**
+     * Create a new BluetoothDevice
+     * Bluetooth MAC address must be upper case, such as "00:11:22:33:AA:BB",
+     * and is validated in this constructor.
+     * @param address valid Bluetooth MAC address
+     * @throws RuntimeException Bluetooth is not available on this platform
+     * @throws IllegalArgumentException address is invalid
+     * @hide
+     */
+    /*package*/ BluetoothDevice(String address) {
+        getService();  // ensures sService is initialized
         if (!BluetoothAdapter.checkBluetoothAddress(address)) {
             throw new IllegalArgumentException(address + " is not a valid Bluetooth address");
         }
@@ -551,7 +559,7 @@ public final class BluetoothDevice implements Parcelable {
       */
      public boolean fetchUuidsWithSdp() {
         try {
-            return sService.fetchRemoteUuidsWithSdp(mAddress);
+            return sService.fetchRemoteUuids(mAddress, null, null);
         } catch (RemoteException e) {Log.e(TAG, "", e);}
         return false;
     }
@@ -598,7 +606,7 @@ public final class BluetoothDevice implements Parcelable {
 
     /**
      * Create an RFCOMM {@link BluetoothSocket} ready to start a secure
-     * outgoing connection to this remote device.
+     * outgoing connection to this remote device on given channel.
      * <p>The remote device will be authenticated and communication on this
      * socket will be encrypted.
      * <p>Use {@link BluetoothSocket#connect} to intiate the outgoing
@@ -610,9 +618,34 @@ public final class BluetoothDevice implements Parcelable {
      * @return a RFCOMM BluetoothServerSocket ready for an outgoing connection
      * @throws IOException on error, for example Bluetooth not available, or
      *                     insufficient permissions
+     * @hide
      */
     public BluetoothSocket createRfcommSocket(int channel) throws IOException {
-        return new BluetoothSocket(BluetoothSocket.TYPE_RFCOMM, -1, true, true, this, channel);
+        return new BluetoothSocket(BluetoothSocket.TYPE_RFCOMM, -1, true, true, this, channel,
+                null);
+    }
+
+    /**
+     * Create an RFCOMM {@link BluetoothSocket} ready to start a secure
+     * outgoing connection to this remote device using SDP lookup of uuid.
+     * <p>This is designed to be used with {@link
+     * BluetoothAdapter#listenUsingRfcommWithServiceRecord} for peer-peer
+     * Bluetooth applications.
+     * <p>Use {@link BluetoothSocket#connect} to intiate the outgoing
+     * connection. This will also perform an SDP lookup of the given uuid to
+     * determine which channel to connect to.
+     * <p>The remote device will be authenticated and communication on this
+     * socket will be encrypted.
+     * <p>Requires {@link android.Manifest.permission#BLUETOOTH}
+     *
+     * @param uuid service record uuid to lookup RFCOMM channel
+     * @return a RFCOMM BluetoothServerSocket ready for an outgoing connection
+     * @throws IOException on error, for example Bluetooth not available, or
+     *                     insufficient permissions
+     */
+    public BluetoothSocket createRfcommSocketToServiceRecord(UUID uuid) throws IOException {
+        return new BluetoothSocket(BluetoothSocket.TYPE_RFCOMM, -1, true, true, this, -1,
+                new ParcelUuid(uuid));
     }
 
     /**
@@ -628,7 +661,8 @@ public final class BluetoothDevice implements Parcelable {
      * @hide
      */
     public BluetoothSocket createInsecureRfcommSocket(int port) throws IOException {
-        return new BluetoothSocket(BluetoothSocket.TYPE_RFCOMM, -1, false, false, this, port);
+        return new BluetoothSocket(BluetoothSocket.TYPE_RFCOMM, -1, false, false, this, port,
+                null);
     }
 
     /**
@@ -640,7 +674,7 @@ public final class BluetoothDevice implements Parcelable {
      * @hide
      */
     public BluetoothSocket createScoSocket() throws IOException {
-        return new BluetoothSocket(BluetoothSocket.TYPE_SCO, -1, true, true, this, -1);
+        return new BluetoothSocket(BluetoothSocket.TYPE_SCO, -1, true, true, this, -1, null);
     }
 
     /**
diff --git a/core/java/android/bluetooth/BluetoothServerSocket.java b/core/java/android/bluetooth/BluetoothServerSocket.java
index d126ea4..605bdc1 100644
--- a/core/java/android/bluetooth/BluetoothServerSocket.java
+++ b/core/java/android/bluetooth/BluetoothServerSocket.java
@@ -36,13 +36,13 @@ import java.io.IOException;
  * connection orientated, streaming transport over Bluetooth. It is also known
  * as the Serial Port Profile (SPP).
  *
- * <p>Use {@link BluetoothDevice#createRfcommSocket} to create a new {@link
- * BluetoothSocket} ready for an outgoing connection to a remote
+ * <p>Use {@link BluetoothDevice#createRfcommSocketToServiceRecord} to create
+ * a new {@link BluetoothSocket} ready for an outgoing connection to a remote
  * {@link BluetoothDevice}.
  *
- * <p>Use {@link BluetoothAdapter#listenUsingRfcomm} to create a listening
- * {@link BluetoothServerSocket} ready for incoming connections to the local
- * {@link BluetoothAdapter}.
+ * <p>Use {@link BluetoothAdapter#listenUsingRfcommWithServiceRecord} to
+ * create a listening {@link BluetoothServerSocket} ready for incoming
+ * connections to the local {@link BluetoothAdapter}.
  *
  * <p>{@link BluetoothSocket} and {@link BluetoothServerSocket} are thread
  * safe. In particular, {@link #close} will always immediately abort ongoing
@@ -68,7 +68,7 @@ public final class BluetoothServerSocket implements Closeable {
      */
     /*package*/ BluetoothServerSocket(int type, boolean auth, boolean encrypt, int port)
             throws IOException {
-        mSocket = new BluetoothSocket(type, -1, auth, encrypt, null, port);
+        mSocket = new BluetoothSocket(type, -1, auth, encrypt, null, port, null);
     }
 
     /**
diff --git a/core/java/android/bluetooth/BluetoothSocket.java b/core/java/android/bluetooth/BluetoothSocket.java
index b9e33f3..7e72590 100644
--- a/core/java/android/bluetooth/BluetoothSocket.java
+++ b/core/java/android/bluetooth/BluetoothSocket.java
@@ -16,11 +16,15 @@
 
 package android.bluetooth;
 
+import android.bluetooth.IBluetoothCallback;
+import android.os.ParcelUuid;
+import android.os.RemoteException;
+import android.util.Log;
+
 import java.io.Closeable;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
-
 import java.util.concurrent.locks.ReentrantReadWriteLock;
 
 /**
@@ -38,13 +42,13 @@ import java.util.concurrent.locks.ReentrantReadWriteLock;
  * connection orientated, streaming transport over Bluetooth. It is also known
  * as the Serial Port Profile (SPP).
  *
- * <p>Use {@link BluetoothDevice#createRfcommSocket} to create a new {@link
- * BluetoothSocket} ready for an outgoing connection to a remote
+ * <p>Use {@link BluetoothDevice#createRfcommSocketToServiceRecord} to create
+ * a new {@link BluetoothSocket} ready for an outgoing connection to a remote
  * {@link BluetoothDevice}.
  *
- * <p>Use {@link BluetoothAdapter#listenUsingRfcomm} to create a listening
- * {@link BluetoothServerSocket} ready for incoming connections to the local
- * {@link BluetoothAdapter}.
+ * <p>Use {@link BluetoothAdapter#listenUsingRfcommWithServiceRecord} to
+ * create a listening {@link BluetoothServerSocket} ready for incoming
+ * connections to the local {@link BluetoothAdapter}.
  *
  * <p>{@link BluetoothSocket} and {@link BluetoothServerSocket} are thread
  * safe. In particular, {@link #close} will always immediately abort ongoing
@@ -54,6 +58,8 @@ import java.util.concurrent.locks.ReentrantReadWriteLock;
  * {@link android.Manifest.permission#BLUETOOTH}
  */
 public final class BluetoothSocket implements Closeable {
+    private static final String TAG = "BluetoothSocket";
+
     /** @hide */
     public static final int MAX_RFCOMM_CHANNEL = 30;
 
@@ -66,13 +72,15 @@ public final class BluetoothSocket implements Closeable {
     /*package*/ static final int EADDRINUSE = 98;
 
     private final int mType;  /* one of TYPE_RFCOMM etc */
-    private final int mPort;  /* RFCOMM channel or L2CAP psm */
     private final BluetoothDevice mDevice;    /* remote device */
     private final String mAddress;    /* remote address */
     private final boolean mAuth;
     private final boolean mEncrypt;
     private final BluetoothInputStream mInputStream;
     private final BluetoothOutputStream mOutputStream;
+    private final SdpHelper mSdp;
+
+    private int mPort;  /* RFCOMM channel or L2CAP psm */
 
     /** prevents all native calls after destroyNative() */
     private boolean mClosed;
@@ -91,16 +99,24 @@ public final class BluetoothSocket implements Closeable {
      * @param encrypt require the connection to be encrypted
      * @param device  remote device that this socket can connect to
      * @param port    remote port
+     * @param uuid    SDP uuid
      * @throws IOException On error, for example Bluetooth not available, or
      *                     insufficient priveleges
      */
     /*package*/ BluetoothSocket(int type, int fd, boolean auth, boolean encrypt,
-            BluetoothDevice device, int port) throws IOException {
-        if (type == BluetoothSocket.TYPE_RFCOMM) {
+            BluetoothDevice device, int port, ParcelUuid uuid) throws IOException {
+        if (type == BluetoothSocket.TYPE_RFCOMM && uuid == null && fd == -1) {
             if (port < 1 || port > MAX_RFCOMM_CHANNEL) {
                 throw new IOException("Invalid RFCOMM channel: " + port);
             }
         }
+        if (uuid == null) {
+            mPort = port;
+            mSdp = null;
+        } else {
+            mSdp = new SdpHelper(device, uuid);
+            mPort = -1;
+        }
         mType = type;
         mAuth = auth;
         mEncrypt = encrypt;
@@ -110,7 +126,6 @@ public final class BluetoothSocket implements Closeable {
         } else {
             mAddress = device.getAddress();
         }
-        mPort = port;
         if (fd == -1) {
             initSocketNative();
         } else {
@@ -123,7 +138,7 @@ public final class BluetoothSocket implements Closeable {
     }
 
     /**
-     * Construct a BluetoothSocket from address.
+     * Construct a BluetoothSocket from address. Used by native code.
      * @param type    type of socket
      * @param fd      fd to use for connected socket, or -1 for a new socket
      * @param auth    require the remote device to be authenticated
@@ -135,7 +150,7 @@ public final class BluetoothSocket implements Closeable {
      */
     private BluetoothSocket(int type, int fd, boolean auth, boolean encrypt, String address,
             int port) throws IOException {
-        this(type, fd, auth, encrypt, new BluetoothDevice(address), port);
+        this(type, fd, auth, encrypt, new BluetoothDevice(address), port, null);
     }
 
     /** @hide */
@@ -160,7 +175,12 @@ public final class BluetoothSocket implements Closeable {
         mLock.readLock().lock();
         try {
             if (mClosed) throw new IOException("socket closed");
-            connectNative();
+
+            if (mSdp != null) {
+                mPort = mSdp.doSdp();  // blocks
+            }
+
+            connectNative();  // blocks
         } finally {
             mLock.readLock().unlock();
         }
@@ -176,12 +196,15 @@ public final class BluetoothSocket implements Closeable {
         mLock.readLock().lock();
         try {
             if (mClosed) return;
+            if (mSdp != null) {
+                mSdp.cancel();
+            }
             abortNative();
         } finally {
             mLock.readLock().unlock();
         }
 
-        // all native calls are guarenteed to immediately return after
+        // all native calls are guaranteed to immediately return after
         // abortNative(), so this lock should immediatley acquire
         mLock.writeLock().lock();
         try {
@@ -291,4 +314,62 @@ public final class BluetoothSocket implements Closeable {
      * use strerr to convert to string error.
      */
     /*package*/ native void throwErrnoNative(int errno) throws IOException;
+
+    /**
+     * Helper to perform blocking SDP lookup.
+     */
+    private static class SdpHelper extends IBluetoothCallback.Stub {
+        private final IBluetooth service;
+        private final ParcelUuid uuid;
+        private final BluetoothDevice device;
+        private int channel;
+        private boolean canceled;
+        public SdpHelper(BluetoothDevice device, ParcelUuid uuid) {
+            service = BluetoothDevice.getService();
+            this.device = device;
+            this.uuid = uuid;
+            canceled = false;
+        }
+        /**
+         * Returns the RFCOMM channel for the UUID, or throws IOException
+         * on failure.
+         */
+        public synchronized int doSdp() throws IOException {
+            if (canceled) throw new IOException("Service discovery canceled");
+            channel = -1;
+
+            boolean inProgress = false;
+            try {
+                inProgress = service.fetchRemoteUuids(device.getAddress(), uuid, this);
+            } catch (RemoteException e) {Log.e(TAG, "", e);}
+
+            if (!inProgress) throw new IOException("Unable to start Service Discovery");
+
+            try {
+                /* 12 second timeout as a precaution - onRfcommChannelFound
+                 * should always occur before the timeout */
+                wait(12000);   // block
+
+            } catch (InterruptedException e) {}
+
+            if (canceled) throw new IOException("Service discovery canceled");
+            if (channel < 1) throw new IOException("Service discovery failed");
+
+            return channel;
+        }
+        /** Object cannot be re-used after calling cancel() */
+        public synchronized void cancel() {
+            if (!canceled) {
+                canceled = true;
+                channel = -1;
+                notifyAll();  // unblock
+            }
+        }
+        public synchronized void onRfcommChannelFound(int channel) {
+            if (!canceled) {
+                this.channel = channel;
+                notifyAll();  // unblock
+            }
+        }
+    }
 }
diff --git a/core/java/android/bluetooth/IBluetooth.aidl b/core/java/android/bluetooth/IBluetooth.aidl
index e54abec..7e752af 100644
--- a/core/java/android/bluetooth/IBluetooth.aidl
+++ b/core/java/android/bluetooth/IBluetooth.aidl
@@ -16,6 +16,7 @@
 
 package android.bluetooth;
 
+import android.bluetooth.IBluetoothCallback;
 import android.os.ParcelUuid;
 
 /**
@@ -53,8 +54,8 @@ interface IBluetooth
     String getRemoteName(in String address);
     int getRemoteClass(in String address);
     ParcelUuid[] getRemoteUuids(in String address);
-    boolean fetchRemoteUuidsWithSdp(in String address);
-    int getRemoteServiceChannel(in String address,in ParcelUuid uuid);
+    boolean fetchRemoteUuids(in String address, in ParcelUuid uuid, in IBluetoothCallback callback);
+    int getRemoteServiceChannel(in String address, in ParcelUuid uuid);
 
     boolean setPin(in String address, in byte[] pin);
     boolean setPasskey(in String address, int passkey);
diff --git a/core/java/android/bluetooth/IBluetoothCallback.aidl b/core/java/android/bluetooth/IBluetoothCallback.aidl
new file mode 100644
index 0000000..8edb3f4
--- /dev/null
+++ b/core/java/android/bluetooth/IBluetoothCallback.aidl
@@ -0,0 +1,27 @@
+/*
+ * Copyright (C) 2009, 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.
+ */
+
+package android.bluetooth;
+
+/**
+ * System private API for Bluetooth service callbacks.
+ *
+ * {@hide}
+ */
+interface IBluetoothCallback
+{
+    void onRfcommChannelFound(int channel);
+}