termux · xalexalex · Oct 6, 2019 · Oct 6, 2019
diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
@@ -34,6 +34,7 @@
     <uses-feature android:name="android.hardware.microphone" android:required="false" />
     <uses-feature android:name="android.hardware.telephony" android:required="false" />
     <uses-feature android:name="android.hardware.wifi" android:required="false" />
+    <uses-feature android:name="android.hardware.usb.host" android:required="false" />
 
     <!-- This permission is not used, but a permission is needed on the sharedfiles contentprovider,
          which will always use FLAG_GRANT_READ_URI_PERMISSION. -->

diff --git a/app/src/main/java/com/termux/api/TermuxApiReceiver.java b/app/src/main/java/com/termux/api/TermuxApiReceiver.java
@@ -174,6 +174,9 @@ private void doWork(Context context, Intent intent) {
             case "Torch":
                 TorchAPI.onReceive(this, context, intent);
                 break;
+            case "Usb":
+                UsbAPI.onReceive(this, context, intent);
+                break;
             case "Vibrate":
                 VibrateAPI.onReceive(this, context, intent);
                 break;

diff --git a/app/src/main/java/com/termux/api/UsbAPI.java b/app/src/main/java/com/termux/api/UsbAPI.java
@@ -0,0 +1,165 @@
+package com.termux.api;
+
+import android.app.PendingIntent;
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+import android.hardware.usb.UsbDevice;
+import android.hardware.usb.UsbDeviceConnection;
+import android.hardware.usb.UsbManager;
+import android.os.Looper;
+import android.util.JsonWriter;
+import android.util.SparseArray;
+
+import com.termux.api.util.ResultReturner;
+
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.util.Iterator;
+import java.util.HashMap;
+
+import androidx.annotation.NonNull;
+
+public class UsbAPI {
+
+    private static SparseArray<UsbDeviceConnection> openDevices = new SparseArray<>();
+
+    static void onReceive(final TermuxApiReceiver apiReceiver, final Context context, final Intent intent) {
+        UsbDevice device;
+        String action = intent.getAction();
+        if (action == null) {
+            ResultReturner.returnData(apiReceiver, intent, out -> out.append("Missing action\n"));
+        } else {
+            switch (action) {
+                case "list":
+                    ResultReturner.returnData(apiReceiver, intent, new ResultReturner.ResultJsonWriter() {
+                        @Override
+                        public void writeJson(JsonWriter out) throws Exception {
+                            listDevices(context, out);
+                        }
+                    });
+                    break;
+                case "permission":
+                    device = getDevice(apiReceiver, context, intent);
+                    if (device == null) return;
+                    ResultReturner.returnData(apiReceiver, intent, out -> {
+                        boolean result = getPermission(device, context, intent);
+                        out.append(result ? "yes\n" : "no\n");
+                    });
+                    break;
+                case "open":
+                    device = getDevice(apiReceiver, context, intent);
+                    if (device == null) return;
+                    ResultReturner.returnData(apiReceiver, intent, new ResultReturner.WithAncillaryFd() {
+                                @Override
+                                public void writeResult(PrintWriter out) {
+                                    if (getPermission(device, context, intent)) {
+                                        int result = open(device, context);
+                                        if (result < 0) {
+                                            out.append("Failed to open device\n");
+                                        } else {
+                                            this.setFd(result);
+                                            out.append("@"); // has to be non-empty
+                                        }
+                                    } else out.append("No permission\n");
+                                }
+                            });
+
+                    break;
+                default:
+                    ResultReturner.returnData(apiReceiver, intent, out -> out.append("Invalid action\n"));
+            }
+        }
+
+    }
+
+    private static void listDevices(final Context context, JsonWriter out) throws IOException {
+        final UsbManager usbManager = (UsbManager) context.getSystemService(Context.USB_SERVICE);
+        HashMap<String, UsbDevice> deviceList = usbManager.getDeviceList();
+        Iterator<String> deviceIterator = deviceList.keySet().iterator();
+        out.beginArray();
+        while (deviceIterator.hasNext()) {
+            out.value(deviceIterator.next());
+        }
+        out.endArray();
+    }
+
+    private static UsbDevice getDevice(final TermuxApiReceiver apiReceiver, final Context context, final Intent intent) {
+        String deviceName = intent.getStringExtra("device");
+        final UsbManager usbManager = (UsbManager) context.getSystemService(Context.USB_SERVICE);
+        HashMap<String, UsbDevice> deviceList = usbManager.getDeviceList();
+        UsbDevice device = deviceList.get(deviceName);
+        if (device == null) {
+            ResultReturner.returnData(apiReceiver, intent, out -> out.append("No such device\n"));
+        }
+        return device;
+    }
+
+    private static boolean hasPermission(final @NonNull UsbDevice device, final Context context) {
+        final UsbManager usbManager = (UsbManager) context.getSystemService(Context.USB_SERVICE);
+        return usbManager.hasPermission(device);
+    }
+
+    private static boolean requestPermission(final @NonNull UsbDevice device, final Context context) {
+        Looper.prepare();
+        Looper looper = Looper.myLooper();
+        final boolean[] result = new boolean[1];
+
+        final String ACTION_USB_PERMISSION = "com.termux.api.USB_PERMISSION";
+        final BroadcastReceiver usbReceiver = new BroadcastReceiver() {
+            @Override
+            public void onReceive(final Context usbContext, final Intent usbIntent) {
+                String action = usbIntent.getAction();
+                if (ACTION_USB_PERMISSION.equals(action)) {
+                    synchronized (this) {
+                        UsbDevice device = usbIntent.getParcelableExtra(UsbManager.EXTRA_DEVICE);
+                        if (usbIntent.getBooleanExtra(UsbManager.EXTRA_PERMISSION_GRANTED, false)) {
+                            if (device != null) {
+                                result[0] = true;
+                                if (looper != null) looper.quit();
+                            }
+                        } else {
+                            result[0] = false;
+                            if (looper != null) looper.quit();
+                        }
+                    }
+
+                }
+            }
+        };
+
+        final UsbManager usbManager = (UsbManager) context.getSystemService(Context.USB_SERVICE);
+        PendingIntent permissionIntent = PendingIntent.getBroadcast(context, 0,
+                new Intent(ACTION_USB_PERMISSION), 0);
+        IntentFilter filter = new IntentFilter(ACTION_USB_PERMISSION);
+        context.getApplicationContext().registerReceiver(usbReceiver, filter);
+        usbManager.requestPermission(device, permissionIntent);
+        Looper.loop();
+        return result[0];
+    }
+
+    private static boolean getPermission(final @NonNull UsbDevice device, final Context context, final Intent intent) {
+        boolean request = intent.getBooleanExtra("request", false);
+        if(request) {
+            return requestPermission(device, context);
+        } else {
+            return hasPermission(device, context);
+        }
+    }
+
+    private static int open(final @NonNull UsbDevice device, final Context context) {
+        final UsbManager usbManager = (UsbManager) context.getSystemService(Context.USB_SERVICE);
+        UsbDeviceConnection connection = usbManager.openDevice(device);
+        if (connection == null)
+            return -2;
+        int fd = connection.getFileDescriptor();
+        if (fd == -1) {
+            connection.close();
+            return -1;
+        }
+        openDevices.put(fd, connection);
+        return fd;
+    }
+
+}
diff --git a/app/src/main/java/com/termux/api/util/ResultReturner.java b/app/src/main/java/com/termux/api/util/ResultReturner.java
@@ -7,9 +7,11 @@
 import android.content.Intent;
 import android.net.LocalSocket;
 import android.net.LocalSocketAddress;
+import android.os.ParcelFileDescriptor;
 import android.util.JsonWriter;
 
 import java.io.ByteArrayOutputStream;
+import java.io.FileDescriptor;
 import java.io.InputStream;
 import java.io.PrintWriter;
 import java.nio.charset.StandardCharsets;
@@ -66,6 +68,18 @@ public final void setInput(InputStream inputStream) throws Exception {
         }
     }
 
+    public static abstract class WithAncillaryFd implements ResultWriter {
+        private int fd = -1;
+
+        public final void setFd(int newFd) {
+            fd = newFd;
+        }
+
+        public final int getFd() {
+            return fd;
+        }
+    }
+
     public static abstract class ResultJsonWriter implements ResultWriter {
         @Override
         public final void writeResult(PrintWriter out) throws Exception {
@@ -102,6 +116,7 @@ public static void returnData(Object context, final Intent intent, final ResultW
 
         final Runnable runnable = () -> {
             try {
+                final ParcelFileDescriptor[] pfds = { null };
                 try (LocalSocket outputSocket = new LocalSocket()) {
                     String outputSocketAdress = intent.getStringExtra(SOCKET_OUTPUT_EXTRA);
                     outputSocket.connect(new LocalSocketAddress(outputSocketAdress));
@@ -117,9 +132,20 @@ public static void returnData(Object context, final Intent intent, final ResultW
                             } else {
                                 resultWriter.writeResult(writer);
                             }
+                            if(resultWriter instanceof WithAncillaryFd) {
+                                int fd = ((WithAncillaryFd) resultWriter).getFd();
+                                if (fd >= 0) {
+                                    pfds[0] = ParcelFileDescriptor.adoptFd(fd);
+                                    FileDescriptor[] fds = { pfds[0].getFileDescriptor() };
+                                    outputSocket.setFileDescriptorsForSend(fds);
+                                }
+                            }
                         }
                     }
                 }
+                if(pfds[0] != null) {
+                    pfds[0].close();
+                }
 
                 if (asyncResult != null) {
                     asyncResult.setResultCode(0);