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Commit 64aee910 authored by Paul McLean's avatar Paul McLean
Browse files

Restrict enumeration of USB Audio Interfaces 

Bug: 136083296
Test: build, flash, connect USB interface, examine logs
Test: No regressions for normal audio playback w/ Presonus, USB-C
Headset.

Note that since this ONLY modifies the interfaces enumerated in the
UsbHost API, it has no effect on normal, framework access to USB Audio.

Change-Id: Ib7d4c83744dfb0961360749c01b008aa9ab9baa2
parent f7f61995

services/usb/java/com/android/server/usb/descriptors/UsbConfigDescriptor.java

+23 −7
Original line number Diff line number Diff line
@@ -41,6 +41,8 @@ public final class UsbConfigDescriptor extends UsbDescriptor { 
                                 //     D4..0 Reserved, set to 0.

    private int mMaxPower;       // 8:1 Maximum Power Consumption in 2mA units



    private boolean mBlockAudio; // leave it off for now. We be replace with a "Developer Option"



    private ArrayList<UsbInterfaceDescriptor> mInterfaceDescriptors =

            new ArrayList<UsbInterfaceDescriptor>();
@@ -77,21 +79,35 @@ public final class UsbConfigDescriptor extends UsbDescriptor { 
        mInterfaceDescriptors.add(interfaceDesc);

    }



    private boolean isAudioInterface(UsbInterfaceDescriptor descriptor) {

        return descriptor.getUsbClass() == UsbDescriptor.CLASSID_AUDIO

                && descriptor.getUsbSubclass() == UsbDescriptor.AUDIO_AUDIOSTREAMING;

    }



    UsbConfiguration toAndroid(UsbDescriptorParser parser) {

        if (UsbDescriptorParser.DEBUG) {

            Log.d(TAG, "  toAndroid()");

        }



        // NOTE - This code running in the server process.

        //TODO (pmclean@) - remove this

//        int pid = android.os.Process.myPid();

//        int uid = android.os.Process.myUid();

//        Log.d(TAG, "  ---- pid:" + pid + " uid:" + uid);



        String name = parser.getDescriptorString(mConfigIndex);

        UsbConfiguration config = new

                UsbConfiguration(mConfigValue, name, mAttribs, mMaxPower);

        UsbInterface[] interfaces = new UsbInterface[mInterfaceDescriptors.size()];

        if (UsbDescriptorParser.DEBUG) {

            Log.d(TAG, "    " + mInterfaceDescriptors.size() + " interfaces.");



        ArrayList<UsbInterface> filteredInterfaces = new ArrayList<UsbInterface>();

        for (UsbInterfaceDescriptor descriptor : mInterfaceDescriptors) {

            if (!mBlockAudio || !isAudioInterface(descriptor)) {

                filteredInterfaces.add(descriptor.toAndroid(parser));

            }

        for (int index = 0; index < mInterfaceDescriptors.size(); index++) {

            interfaces[index] = mInterfaceDescriptors.get(index).toAndroid(parser);

        }

        config.setInterfaces(interfaces);

        UsbInterface[] interfaceArray = new UsbInterface[0];

        interfaceArray = filteredInterfaces.toArray(interfaceArray);

        config.setInterfaces(interfaceArray);

        return config;

    }

services/usb/java/com/android/server/usb/descriptors/UsbDescriptorParser.java

+1 −1
Original line number Diff line number Diff line
@@ -26,7 +26,7 @@ import java.util.ArrayList; 
 */

public final class UsbDescriptorParser {

    private static final String TAG = "UsbDescriptorParser";

    public static final boolean DEBUG = false;

    public static final boolean DEBUG = true;



    private final String mDeviceAddr;

services/usb/java/com/android/server/usb/descriptors/UsbEndpointDescriptor.java

+8 −6
Original line number Diff line number Diff line
@@ -31,7 +31,7 @@ public class UsbEndpointDescriptor extends UsbDescriptor { 
    public static final int MASK_ENDPOINT_ADDRESS = 0b000000000001111;

    public static final int MASK_ENDPOINT_DIRECTION = (byte) 0b0000000010000000;

    public static final int DIRECTION_OUTPUT = 0x0000;

    public static final int DIRECTION_INPUT = (byte) 0x0080;

    public static final int DIRECTION_INPUT = 0x0080;



    public static final int MASK_ATTRIBS_TRANSTYPE = 0b00000011;

    public static final int TRANSTYPE_CONTROL = 0x00;
@@ -85,7 +85,7 @@ public class UsbEndpointDescriptor extends UsbDescriptor { 
    }



    public int getEndpointAddress() {

        return mEndpointAddress;

        return mEndpointAddress & MASK_ENDPOINT_ADDRESS;

    }



    public int getAttributes() {
@@ -108,6 +108,10 @@ public class UsbEndpointDescriptor extends UsbDescriptor { 
        return mSyncAddress;

    }



    public int getDirection() {

        return mEndpointAddress & UsbEndpointDescriptor.MASK_ENDPOINT_DIRECTION;

    }



    /* package */ UsbEndpoint toAndroid(UsbDescriptorParser parser) {

        if (UsbDescriptorParser.DEBUG) {

            Log.d(TAG, "toAndroid() type:"
@@ -137,11 +141,9 @@ public class UsbEndpointDescriptor extends UsbDescriptor { 


        canvas.openList();



        int address = getEndpointAddress();

        canvas.writeListItem("Address: "

                + ReportCanvas.getHexString(address & UsbEndpointDescriptor.MASK_ENDPOINT_ADDRESS)

                + ((address & UsbEndpointDescriptor.MASK_ENDPOINT_DIRECTION)

                == UsbEndpointDescriptor.DIRECTION_OUTPUT ? " [out]" : " [in]"));

                + ReportCanvas.getHexString(getEndpointAddress())

                + (getDirection() == UsbEndpointDescriptor.DIRECTION_OUTPUT ? " [out]" : " [in]"));



        int attributes = getAttributes();

        canvas.openListItem();

services/usb/java/com/android/server/usb/descriptors/UsbInterfaceDescriptor.java

+13 −1
Original line number Diff line number Diff line
@@ -31,7 +31,6 @@ import java.util.ArrayList; 
 */

public class UsbInterfaceDescriptor extends UsbDescriptor {

    private static final String TAG = "UsbInterfaceDescriptor";



    protected int mInterfaceNumber;   // 2:1 Number of Interface

    protected byte mAlternateSetting; // 3:1 Value used to select alternative setting

    protected byte mNumEndpoints;     // 4:1 Number of Endpoints used for this interface
@@ -73,6 +72,19 @@ public class UsbInterfaceDescriptor extends UsbDescriptor { 
        return mNumEndpoints;

    }



    /**

     * @param index Index of desired UsbEndpointDescriptor.

     * @return the UsbEndpointDescriptor descriptor at the specified index, or

     *  null if an invalid index.

     */

    public UsbEndpointDescriptor getEndpointDescriptor(int index) {

        if (index < 0 || index >= mEndpointDescriptors.size()) {

            return null;

        }



        return mEndpointDescriptors.get(index);

    }



    public int getUsbClass() {

        return mUsbClass;

    }