export: use content resolver on android Q+

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

app/src/main/java/com/wireguard/android/preference/LogExporterPreference.java

@@ -8,22 +8,21 @@ package com.wireguard.android.preference;
 import android.Manifest;
 import android.content.Context;
 import android.content.pm.PackageManager;
-import android.os.Environment;
 import androidx.annotation.Nullable;
 import com.google.android.material.snackbar.Snackbar;
 import androidx.preference.Preference;
+
 import android.util.AttributeSet;
 import android.util.Log;
 
 import com.wireguard.android.Application;
 import com.wireguard.android.R;
+import com.wireguard.android.util.DownloadsFileSaver;
+import com.wireguard.android.util.DownloadsFileSaver.DownloadsFile;
 import com.wireguard.android.util.ErrorMessages;
 import com.wireguard.android.util.FragmentUtils;
 
 import java.io.BufferedReader;
-import java.io.File;
-import java.io.FileOutputStream;
-import java.io.IOException;
 import java.io.InputStreamReader;
 
 /**
@@ -41,36 +40,33 @@ public class LogExporterPreference extends Preference {
 
     private void exportLog() {
         Application.getAsyncWorker().supplyAsync(() -> {
-            final File path = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS);
-            final File file = new File(path, "wireguard-log.txt");
-            if (!path.isDirectory() && !path.mkdirs())
-                throw new IOException(
-                        getContext().getString(R.string.create_output_dir_error));
-
-            /* We would like to simply run `builder.redirectOutput(file);`, but this is API 26.
-             * Instead we have to do this dance, since logcat appends.
-             */
-            new FileOutputStream(file).close();
-
+            DownloadsFile outputFile = DownloadsFileSaver.save(getContext(), "wireguard-log.txt", "text/plain", true);
             try {
                 final Process process = Runtime.getRuntime().exec(new String[]{
-                        "logcat", "-b", "all", "-d", "-v", "threadtime", "-f", file.getAbsolutePath(), "*:V"});
-                if (process.waitFor() != 0) {
-                    try (final BufferedReader reader = new BufferedReader(new InputStreamReader(process.getErrorStream()))) {
+                        "logcat", "-b", "all", "-d", "-v", "threadtime", "*:V"});
+                try (final BufferedReader stdout = new BufferedReader(new InputStreamReader(process.getInputStream()));
+                     final BufferedReader stderr = new BufferedReader(new InputStreamReader(process.getErrorStream())))
+                {
+                    String line;
+                    while ((line = stdout.readLine()) != null) {
+                        outputFile.getOutputStream().write(line.getBytes());
+                        outputFile.getOutputStream().write('\n');
+                    }
+                    outputFile.getOutputStream().close();
+                    stdout.close();
+                    if (process.waitFor() != 0) {
                         final StringBuilder errors = new StringBuilder();
-                        errors.append("Unable to run logcat: ");
-                        String line;
-                        while ((line = reader.readLine()) != null)
+                        errors.append(R.string.logcat_error);
+                        while ((line = stderr.readLine()) != null)
                             errors.append(line);
                         throw new Exception(errors.toString());
                     }
                 }
             } catch (final Exception e) {
-                // noinspection ResultOfMethodCallIgnored
-                file.delete();
+                outputFile.delete();
                 throw e;
             }
-            return file.getAbsolutePath();
+            return outputFile.getFileName();
         }).whenComplete(this::exportLogComplete);
     }
 

app/src/main/java/com/wireguard/android/preference/ZipExporterPreference.java

@@ -8,7 +8,6 @@ package com.wireguard.android.preference;
 import android.Manifest;
 import android.content.Context;
 import android.content.pm.PackageManager;
-import android.os.Environment;
 import androidx.annotation.Nullable;
 import com.google.android.material.snackbar.Snackbar;
 import androidx.preference.Preference;
@@ -18,13 +17,12 @@ import android.util.Log;
 import com.wireguard.android.Application;
 import com.wireguard.android.R;
 import com.wireguard.android.model.Tunnel;
+import com.wireguard.android.util.DownloadsFileSaver;
+import com.wireguard.android.util.DownloadsFileSaver.DownloadsFile;
 import com.wireguard.android.util.ErrorMessages;
 import com.wireguard.android.util.FragmentUtils;
 import com.wireguard.config.Config;
 
-import java.io.File;
-import java.io.FileOutputStream;
-import java.io.IOException;
 import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.List;
@@ -63,12 +61,8 @@ public class ZipExporterPreference extends Preference {
                 .whenComplete((ignored1, exception) -> Application.getAsyncWorker().supplyAsync(() -> {
                     if (exception != null)
                         throw exception;
-                    final File path = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS);
-                    final File file = new File(path, "wireguard-export.zip");
-                    if (!path.isDirectory() && !path.mkdirs())
-                        throw new IOException(
-                                getContext().getString(R.string.create_output_dir_error));
-                    try (ZipOutputStream zip = new ZipOutputStream(new FileOutputStream(file))) {
+                    DownloadsFile outputFile = DownloadsFileSaver.save(getContext(), "wireguard-export.zip", "application/zip", true);
+                    try (ZipOutputStream zip = new ZipOutputStream(outputFile.getOutputStream())) {
                         for (int i = 0; i < futureConfigs.size(); ++i) {
                             zip.putNextEntry(new ZipEntry(tunnels.get(i).getName() + ".conf"));
                             zip.write(futureConfigs.get(i).getNow(null).
@@ -76,11 +70,10 @@ public class ZipExporterPreference extends Preference {
                         }
                         zip.closeEntry();
                     } catch (final Exception e) {
-                        // noinspection ResultOfMethodCallIgnored
-                        file.delete();
+                        outputFile.delete();
                         throw e;
                     }
-                    return file.getAbsolutePath();
+                    return outputFile.getFileName();
                 }).whenComplete(this::exportZipComplete));
     }
 

app/src/main/java/com/wireguard/android/util/DownloadsFileSaver.java

@@ -0,0 +1,96 @@
+/*
+ * Copyright © 2019 WireGuard LLC. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package com.wireguard.android.util;
+
+import android.content.ContentResolver;
+import android.content.ContentValues;
+import android.content.Context;
+import android.database.Cursor;
+import android.net.Uri;
+import android.os.Build;
+import android.os.Environment;
+import android.provider.MediaStore;
+import android.provider.MediaStore.MediaColumns;
+
+import com.wireguard.android.R;
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+
+public class DownloadsFileSaver {
+
+    public static class DownloadsFile {
+        private Context context;
+        private OutputStream outputStream;
+        private String fileName;
+        private Uri uri;
+
+        private DownloadsFile(final Context context, final OutputStream outputStream, final String fileName, final Uri uri) {
+            this.context = context;
+            this.outputStream = outputStream;
+            this.fileName = fileName;
+            this.uri = uri;
+        }
+
+        public OutputStream getOutputStream() { return outputStream; }
+        public String getFileName() { return fileName; }
+
+        public void delete() {
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q)
+                context.getContentResolver().delete(uri, null, null);
+            else
+                new File(fileName).delete();
+        }
+    }
+
+    public static DownloadsFile save(final Context context, final String name, final String mimeType, final boolean overwriteExisting) throws Exception {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
+            final ContentResolver contentResolver = context.getContentResolver();
+            if (overwriteExisting)
+                contentResolver.delete(MediaStore.Downloads.EXTERNAL_CONTENT_URI, String.format("%s = ?", MediaColumns.DISPLAY_NAME), new String[]{name});
+            final ContentValues contentValues = new ContentValues();
+            contentValues.put(MediaColumns.DISPLAY_NAME, name);
+            contentValues.put(MediaColumns.MIME_TYPE, mimeType);
+            final Uri contentUri = contentResolver.insert(MediaStore.Downloads.EXTERNAL_CONTENT_URI, contentValues);
+            if (contentUri == null)
+                throw new IOException(context.getString(R.string.create_downloads_file_error));
+            final OutputStream contentStream = contentResolver.openOutputStream(contentUri);
+            if (contentStream == null)
+                throw new IOException(context.getString(R.string.create_downloads_file_error));
+            Cursor cursor = contentResolver.query(contentUri, new String[]{MediaColumns.DATA}, null, null, null);
+            String path = null;
+            if (cursor != null) {
+                try {
+                    if (cursor.moveToFirst())
+                        path = cursor.getString(0);
+                } finally {
+                    cursor.close();
+                }
+            }
+            if (path == null) {
+                path = "Download/";
+                cursor = contentResolver.query(contentUri, new String[]{MediaColumns.DISPLAY_NAME}, null, null, null);
+                if (cursor != null) {
+                    try {
+                        if (cursor.moveToFirst())
+                            path += cursor.getString(0);
+                    } finally {
+                        cursor.close();
+                    }
+                }
+            }
+            return new DownloadsFile(context, contentStream, path, contentUri);
+        } else {
+            final File path = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS);
+            final File file = new File(path, name);
+            if (!path.isDirectory() && !path.mkdirs())
+                throw new IOException(context.getString(R.string.create_output_dir_error));
+            return new DownloadsFile(context, new FileOutputStream(file), file.getAbsolutePath(), null);
+        }
+    }
+}

app/src/main/java/com/wireguard/config/InetAddresses.java

@@ -46,7 +46,7 @@ public final class InetAddresses {
         if (address.isEmpty())
             throw new ParseException(InetAddress.class, address, "Empty address");
         try {
-            if (Build.VERSION.SDK_INT < 29)
+            if (Build.VERSION.SDK_INT < Build.VERSION_CODES.Q)
                 return (InetAddress) getParserMethod().invoke(null, address);
             else
                 return android.net.InetAddresses.parseNumericAddress(address);

app/src/main/res/values/strings.xml

@@ -59,6 +59,7 @@
     <string name="create_from_file">Create from file or archive</string>
     <string name="create_from_qr_code">Create from QR code</string>
     <string name="create_output_dir_error">Cannot create output directory</string>
+    <string name="create_downloads_file_error">Cannot create file in downloads directory</string>
     <string name="create_temp_dir_error">Cannot create local temporary directory</string>
     <string name="create_tunnel">Create Tunnel</string>
     <string name="dark_theme_summary_off">Currently using light (day) theme</string>
@@ -96,6 +97,7 @@
     <string name="log_export_success">Saved to “%s”</string>
     <string name="log_export_summary">Log file will be saved to downloads folder</string>
     <string name="log_export_title">Export log file</string>
+    <string name="logcat_error">Unable to run logcat: </string>
     <string name="module_version_error">Unable to determine kernel module version</string>
     <string name="mtu">MTU</string>
     <string name="multiple_tunnels_error">Only one userspace tunnel can run at a time</string>