Add new API to scan a given channel set

Create new (hidden) APIs to scan a specified channel set. This is mainly for
location service for now, as doing frequent full scans (including DFS channel)
kills battery.

This set of new APIs contains:
- API to query available channel list for scanning, and DFS channels are marked
- API to scan a specified channel set

Selective scan results are returned in the same way as normal full scan ones.
In order not to intrude full scan results, BSS_FLUSH is NOT performed before a
selective scan. Therefore, selective scan results may contain results that's not
in the given channel set, and post-filtering may be required for location
service use.

Bug: 12610436
Change-Id: Icced18dd9b54f6dd92c0c2874d31518d56af8163

6 files changed, 272 insertions, 4 deletions

diff --git a/wifi/java/android/net/wifi/IWifiManager.aidl b/wifi/java/android/net/wifi/IWifiManager.aidl
index 4a6b1ff..84e933d 100644
--- a/wifi/java/android/net/wifi/IWifiManager.aidl
+++ b/wifi/java/android/net/wifi/IWifiManager.aidl
@@ -20,6 +20,8 @@ import android.net.wifi.BatchedScanResult;
 import android.net.wifi.BatchedScanSettings;
 import android.net.wifi.WifiConfiguration;
 import android.net.wifi.WifiInfo;
+import android.net.wifi.ScanSettings;
+import android.net.wifi.WifiChannel;
 import android.net.wifi.ScanResult;
 import android.net.DhcpInfo;
 
@@ -45,7 +47,9 @@ interface IWifiManager
 
     boolean pingSupplicant();
 
-    void startScan(in WorkSource ws);
+    List<WifiChannel> getChannelList();
+
+    void startScan(in ScanSettings requested, in WorkSource ws);
 
     List<ScanResult> getScanResults(String callingPackage);
 
diff --git a/wifi/java/android/net/wifi/ScanSettings.aidl b/wifi/java/android/net/wifi/ScanSettings.aidl
new file mode 100644
index 0000000..ebd2a39
--- /dev/null
+++ b/wifi/java/android/net/wifi/ScanSettings.aidl
@@ -0,0 +1,19 @@
+/**
+ * Copyright (c) 2014, 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.net.wifi;
+
+parcelable ScanSettings;
diff --git a/wifi/java/android/net/wifi/ScanSettings.java b/wifi/java/android/net/wifi/ScanSettings.java
new file mode 100644
index 0000000..094ce34
--- /dev/null
+++ b/wifi/java/android/net/wifi/ScanSettings.java
@@ -0,0 +1,87 @@
+/*
+ * Copyright (c) 2014, 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.net.wifi;
+
+import android.os.Parcel;
+import android.os.Parcelable;
+
+import java.util.ArrayList;
+import java.util.Collection;
+
+/**
+ * Bundle of customized scan settings
+ *
+ * @see WifiManager#startCustomizedScan
+ *
+ * @hide
+ */
+public class ScanSettings implements Parcelable {
+
+    /** channel set to scan. this can be null or empty, indicating a full scan */
+    public Collection<WifiChannel> channelSet;
+
+    /** public constructor */
+    public ScanSettings() { }
+
+    /** copy constructor */
+    public ScanSettings(ScanSettings source) {
+        if (source.channelSet != null)
+            channelSet = new ArrayList<WifiChannel>(source.channelSet);
+    }
+
+    /** check for validity */
+    public boolean isValid() {
+        for (WifiChannel channel : channelSet)
+            if (!channel.isValid()) return false;
+        return true;
+    }
+
+    /** implement Parcelable interface */
+    @Override
+    public int describeContents() {
+        return 0;
+    }
+
+    /** implement Parcelable interface */
+    @Override
+    public void writeToParcel(Parcel out, int flags) {
+        out.writeInt(channelSet == null ? 0 : channelSet.size());
+        if (channelSet != null)
+            for (WifiChannel channel : channelSet) channel.writeToParcel(out, flags);
+    }
+
+    /** implement Parcelable interface */
+    public static final Parcelable.Creator<ScanSettings> CREATOR =
+            new Parcelable.Creator<ScanSettings>() {
+        @Override
+        public ScanSettings createFromParcel(Parcel in) {
+            ScanSettings settings = new ScanSettings();
+            int size = in.readInt();
+            if (size > 0) {
+                settings.channelSet = new ArrayList<WifiChannel>(size);
+                while (size-- > 0)
+                    settings.channelSet.add(WifiChannel.CREATOR.createFromParcel(in));
+            }
+            return settings;
+        }
+
+        @Override
+        public ScanSettings[] newArray(int size) {
+            return new ScanSettings[size];
+        }
+    };
+}
diff --git a/wifi/java/android/net/wifi/WifiChannel.aidl b/wifi/java/android/net/wifi/WifiChannel.aidl
new file mode 100644
index 0000000..c3d06bd
--- /dev/null
+++ b/wifi/java/android/net/wifi/WifiChannel.aidl
@@ -0,0 +1,19 @@
+/**
+ * Copyright (c) 2014, 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.net.wifi;
+
+parcelable WifiChannel;
diff --git a/wifi/java/android/net/wifi/WifiChannel.java b/wifi/java/android/net/wifi/WifiChannel.java
new file mode 100644
index 0000000..640481e
--- /dev/null
+++ b/wifi/java/android/net/wifi/WifiChannel.java
@@ -0,0 +1,87 @@
+/*
+ * Copyright (c) 2014, 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.net.wifi;
+
+import android.os.Parcel;
+import android.os.Parcelable;
+
+/**
+ * Wifi Channel
+ *
+ * @see ScanSettings
+ *
+ * @hide
+ */
+public class WifiChannel implements Parcelable {
+
+    private static final int MIN_FREQ_MHZ = 2412;
+    private static final int MAX_FREQ_MHZ = 5825;
+
+    private static final int MIN_CHANNEL_NUM = 1;
+    private static final int MAX_CHANNEL_NUM = 196;
+
+    /** frequency */
+    public int freqMHz;
+
+    /** channel number */
+    public int channelNum;
+
+    /** is it a DFS channel? */
+    public boolean isDFS;
+
+    /** public constructor */
+    public WifiChannel() { }
+
+    /** check for validity */
+    public boolean isValid() {
+        if (freqMHz < MIN_FREQ_MHZ || freqMHz > MAX_FREQ_MHZ) return false;
+        if (channelNum < MIN_CHANNEL_NUM || channelNum > MAX_CHANNEL_NUM) return false;
+        return true;
+    }
+
+    /** implement Parcelable interface */
+    @Override
+    public int describeContents() {
+        return 0;
+    }
+
+    /** implement Parcelable interface */
+    @Override
+    public void writeToParcel(Parcel out, int flags) {
+        out.writeInt(freqMHz);
+        out.writeInt(channelNum);
+        out.writeInt(isDFS ? 1 : 0);
+    }
+
+    /** implement Parcelable interface */
+    public static final Parcelable.Creator<WifiChannel> CREATOR =
+            new Parcelable.Creator<WifiChannel>() {
+        @Override
+        public WifiChannel createFromParcel(Parcel in) {
+            WifiChannel channel = new WifiChannel();
+            channel.freqMHz = in.readInt();
+            channel.channelNum = in.readInt();
+            channel.isDFS = in.readInt() != 0;
+            return channel;
+        }
+
+        @Override
+        public WifiChannel[] newArray(int size) {
+            return new WifiChannel[size];
+        }
+    };
+}
diff --git a/wifi/java/android/net/wifi/WifiManager.java b/wifi/java/android/net/wifi/WifiManager.java
index aabe007..0862b7e 100644
--- a/wifi/java/android/net/wifi/WifiManager.java
+++ b/wifi/java/android/net/wifi/WifiManager.java
@@ -20,6 +20,8 @@ import android.annotation.SdkConstant;
 import android.annotation.SdkConstant.SdkConstantType;
 import android.content.Context;
 import android.net.DhcpInfo;
+import android.net.wifi.ScanSettings;
+import android.net.wifi.WifiChannel;
 import android.os.Binder;
 import android.os.IBinder;
 import android.os.Handler;
@@ -763,6 +765,22 @@ public class WifiManager {
     }
 
     /**
+     * Get a list of available channels for customized scan.
+     *
+     * @see {@link WifiChannel}
+     *
+     * @return the channel list, or null if not available
+     * @hide
+     */
+    public List<WifiChannel> getChannelList() {
+        try {
+            return mService.getChannelList();
+        } catch (RemoteException e) {
+            return null;
+        }
+    }
+
+    /**
      * Request a scan for access points. Returns immediately. The availability
      * of the results is made known later by means of an asynchronous event sent
      * on completion of the scan.
@@ -770,8 +788,7 @@ public class WifiManager {
      */
     public boolean startScan() {
         try {
-            final WorkSource workSource = null;
-            mService.startScan(workSource);
+            mService.startScan(null, null);
             return true;
         } catch (RemoteException e) {
             return false;
@@ -781,7 +798,42 @@ public class WifiManager {
     /** @hide */
     public boolean startScan(WorkSource workSource) {
         try {
-            mService.startScan(workSource);
+            mService.startScan(null, workSource);
+            return true;
+        } catch (RemoteException e) {
+            return false;
+        }
+    }
+
+    /**
+     * Request a scan for access points in specified channel list. Each channel is specified by its
+     * frequency in MHz, e.g. "5500" (do NOT include "DFS" even though it is). The availability of
+     * the results is made known later in the same way as {@link #startScan}.
+     *
+     * Note:
+     *
+     * 1. Customized scan is for non-connection purposes, i.e. it won't trigger a wifi connection
+     *    even though it finds some known networks.
+     *
+     * 2. Customized scan result may include access points that is not specified in the channel
+     *    list. An app will need to do frequency filtering if it wants to get pure results for the
+     *    channel list it specified.
+     *
+     * @hide
+     */
+    public boolean startCustomizedScan(ScanSettings requested) {
+        try {
+            mService.startScan(requested, null);
+            return true;
+        } catch (RemoteException e) {
+            return false;
+        }
+    }
+
+    /** @hide */
+    public boolean startCustomizedScan(ScanSettings requested, WorkSource workSource) {
+        try {
+            mService.startScan(requested, workSource);
             return true;
         } catch (RemoteException e) {
             return false;