@Override
public ParcelFileDescriptor openDocument(
String documentId, String mode, CancellationSignal signal) throws FileNotFoundException {
final File file = getFileForDocId(documentId);
final File visibleFile = getFileForDocId(documentId, true);
final int pfdMode = ParcelFileDescriptor.parseMode(mode);
if (pfdMode == ParcelFileDescriptor.MODE_READ_ONLY || visibleFile == null) {
return ParcelFileDescriptor.open(file, pfdMode);
} else {
try {
// When finished writing, kick off media scanner
return ParcelFileDescriptor.open(
file,
pfdMode,
mHandler,
new OnCloseListener() {
@Override
public void onClose(IOException e) {
final Intent intent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
intent.setData(Uri.fromFile(visibleFile));
getContext().sendBroadcast(intent);
}
});
} catch (IOException e) {
throw new FileNotFoundException("Failed to open for writing: " + e);
}
}
}
@NonNull
private ParcelFileDescriptor safeOpenFileHelper(@NonNull Uri uri, @NonNull String mode)
throws FileNotFoundException {
Cursor c = query(uri, new String[] {"_data"}, null, null, null);
int count = (c != null) ? c.getCount() : 0;
if (count != 1) {
// If there is not exactly one result, throw an appropriate
// exception.
if (c != null) {
c.close();
}
if (count == 0) {
throw new FileNotFoundException("No entry for " + uri);
}
throw new FileNotFoundException("Multiple items at " + uri);
}
c.moveToFirst();
int i = c.getColumnIndex("_data");
String path = (i >= 0 ? c.getString(i) : null);
c.close();
if (path == null) {
throw new FileNotFoundException("Column _data not found.");
}
File filePath = new File(path);
try {
// The MmsProvider shouldn't open a file that isn't MMS data, so we verify that the
// _data path actually points to MMS data. That safeguards ourselves from callers who
// inserted or updated a URI (more specifically the _data column) with disallowed paths.
// TODO(afurtado): provide a more robust mechanism to avoid disallowed _data paths to
// be inserted/updated in the first place, including via SQL injection.
if (!filePath
.getCanonicalPath()
.startsWith(getContext().getDir(PARTS_DIR_NAME, 0).getCanonicalPath())) {
Log.e(
TAG,
"openFile: path "
+ filePath.getCanonicalPath()
+ " does not start with "
+ getContext().getDir(PARTS_DIR_NAME, 0).getCanonicalPath());
// Don't care return value
return null;
}
} catch (IOException e) {
Log.e(TAG, "openFile: create path failed " + e, e);
return null;
}
int modeBits = ParcelFileDescriptor.parseMode(mode);
return ParcelFileDescriptor.open(filePath, modeBits);
}