Add ContentProvider to access log file from other applications

src/frontends/android/AndroidManifest.xml

@@ -58,6 +58,11 @@
                 <action android:name="org.strongswan.android.logic.CharonVpnService" />
             </intent-filter>
         </service>
+
+        <provider
+            android:name=".data.LogContentProvider"
+            android:authorities="org.strongswan.android.content.log" >
+        </provider>
     </application>
 
 </manifest>

src/frontends/android/src/org/strongswan/android/data/LogContentProvider.java

@@ -0,0 +1,117 @@
+/*
+ * Copyright (C) 2012 Tobias Brunner
+ * Hochschule fuer Technik Rapperswil
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ */
+
+package org.strongswan.android.data;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+
+import org.strongswan.android.logic.CharonVpnService;
+
+import android.content.ContentProvider;
+import android.content.ContentValues;
+import android.database.Cursor;
+import android.database.MatrixCursor;
+import android.net.Uri;
+import android.os.ParcelFileDescriptor;
+import android.provider.OpenableColumns;
+
+public class LogContentProvider extends ContentProvider
+{
+	private static final String AUTHORITY = "org.strongswan.android.content.log";
+	private File mLogFile;
+
+	public LogContentProvider()
+	{
+	}
+
+	@Override
+	public boolean onCreate()
+	{
+		mLogFile = new File(getContext().getFilesDir(), CharonVpnService.LOG_FILE);
+		return true;
+	}
+
+	/**
+	 * The log file can only be accessed by Uris created with this method
+	 * @return null if failed to create the Uri
+	 */
+	public static Uri createContentUri()
+	{
+		Uri uri = Uri.parse("content://"+ AUTHORITY + "/" + CharonVpnService.LOG_FILE);
+		return uri;
+	}
+
+	@Override
+	public String getType(Uri uri)
+	{
+		/* MIME type for our log file */
+		return "text/plain";
+	}
+
+	@Override
+	public Cursor query(Uri uri, String[] projection, String selection,
+						String[] selectionArgs, String sortOrder)
+	{
+		/* this is called by apps to find out the name and size of the file.
+		 * since we only provide a single file this is simple to implement */
+		if (projection == null || projection.length < 1)
+		{
+			return null;
+		}
+		MatrixCursor cursor = new MatrixCursor(projection, 1);
+		if (OpenableColumns.DISPLAY_NAME.equals(cursor.getColumnName(0)))
+		{
+			cursor.newRow().add(CharonVpnService.LOG_FILE);
+		}
+		else if (OpenableColumns.SIZE.equals(cursor.getColumnName(0)))
+		{
+			cursor.newRow().add(mLogFile.length());
+		}
+		else
+		{
+			return null;
+		}
+		return cursor;
+	}
+
+	@Override
+	public ParcelFileDescriptor openFile(Uri uri, String mode) throws FileNotFoundException
+	{
+		return ParcelFileDescriptor.open(mLogFile, ParcelFileDescriptor.MODE_CREATE | ParcelFileDescriptor.MODE_READ_ONLY);
+	}
+
+	@Override
+	public Uri insert(Uri uri, ContentValues values)
+	{
+		/* not supported */
+		return null;
+	}
+
+	@Override
+	public int delete(Uri uri, String selection, String[] selectionArgs)
+	{
+		/* not supported */
+		return 0;
+	}
+
+	@Override
+	public int update(Uri uri, ContentValues values, String selection,
+					  String[] selectionArgs)
+	{
+		/* not supported */
+		return 0;
+	}
+}