/*
 * Copyright (c) 2008, 2013, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code 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
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package sun.nio.fs;

import java.nio.file.*;
import java.nio.file.attribute.*;
import java.nio.channels.*;
import java.net.URI;
import java.util.concurrent.ExecutorService;
import java.io.*;
import java.util.*;
import java.security.AccessController;
import jdk.internal.misc.Unsafe;
import sun.nio.ch.ThreadPool;
import sun.security.util.SecurityConstants;

import static sun.nio.fs.WindowsNativeDispatcher.*;
import static sun.nio.fs.WindowsSecurity.*;
import static sun.nio.fs.WindowsConstants.*;

public class WindowsFileSystemProvider
    extends AbstractFileSystemProvider
{
    private static final Unsafe unsafe = Unsafe.getUnsafe();

    private static final String USER_DIR = "user.dir";
    private final WindowsFileSystem theFileSystem;

    public WindowsFileSystemProvider() {
        theFileSystem = new WindowsFileSystem(this, System.getProperty(USER_DIR));
    }

    @Override
    public String getScheme() {
        return "file";
    }

    private void checkUri(URI uri) {
        if (!uri.getScheme().equalsIgnoreCase(getScheme()))
            throw new IllegalArgumentException("URI does not match this provider");
        if (uri.getRawAuthority() != null)
            throw new IllegalArgumentException("Authority component present");
        String path = uri.getPath();
        if (path == null)
            throw new IllegalArgumentException("Path component is undefined");
        if (!path.equals("/"))
            throw new IllegalArgumentException("Path component should be '/'");
        if (uri.getRawQuery() != null)
            throw new IllegalArgumentException("Query component present");
        if (uri.getRawFragment() != null)
            throw new IllegalArgumentException("Fragment component present");
    }

    @Override
    public FileSystem newFileSystem(URI uri, Map<String,?> env)
        throws IOException
    {
        checkUri(uri);
        throw new FileSystemAlreadyExistsException();
    }

    @Override
    public final FileSystem getFileSystem(URI uri) {
        checkUri(uri);
        return theFileSystem;
    }

    @Override
    public Path getPath(URI uri) {
        return WindowsUriSupport.fromUri(theFileSystem, uri);
    }

    @Override
    public FileChannel newFileChannel(Path path,
                                      Set<? extends OpenOption> options,
                                      FileAttribute<?>... attrs)
        throws IOException
    {
        if (path == null)
            throw new NullPointerException();
        if (!(path instanceof WindowsPath))
            throw new ProviderMismatchException();
        WindowsPath file = (WindowsPath)path;

        WindowsSecurityDescriptor sd = WindowsSecurityDescriptor.fromAttribute(attrs);
        try {
            return WindowsChannelFactory
                .newFileChannel(file.getPathForWin32Calls(),
                                file.getPathForPermissionCheck(),
                                options,
                                sd.address());
        } catch (WindowsException x) {
            x.rethrowAsIOException(file);
            return null;
        } finally {
            if (sd != null)
                sd.release();
        }
    }

    @Override
    public AsynchronousFileChannel newAsynchronousFileChannel(Path path,
                                                              Set<? extends OpenOption> options,
                                                              ExecutorService executor,
                                                              FileAttribute<?>... attrs)
        throws IOException
    {
        if (path == null)
            throw new NullPointerException();
        if (!(path instanceof WindowsPath))
            throw new ProviderMismatchException();
        WindowsPath file = (WindowsPath)path;
        ThreadPool pool = (executor == null) ? null : ThreadPool.wrap(executor, 0);
        WindowsSecurityDescriptor sd =
            WindowsSecurityDescriptor.fromAttribute(attrs);
        try {
            return WindowsChannelFactory
                .newAsynchronousFileChannel(file.getPathForWin32Calls(),
                                            file.getPathForPermissionCheck(),
                                            options,
                                            sd.address(),
                                            pool);
        } catch (WindowsException x) {
            x.rethrowAsIOException(file);
            return null;
        } finally {
            if (sd != null)
                sd.release();
        }
    }

    @Override
    @SuppressWarnings("unchecked")
    public <V extends FileAttributeView> V
        getFileAttributeView(Path obj, Class<V> view, LinkOption... options)
    {
        WindowsPath file = WindowsPath.toWindowsPath(obj);
        if (view == null)
            throw new NullPointerException();
        boolean followLinks = Util.followLinks(options);
        if (view == BasicFileAttributeView.class)
            return (V) WindowsFileAttributeViews.createBasicView(file, followLinks);
        if (view == DosFileAttributeView.class)
            return (V) WindowsFileAttributeViews.createDosView(file, followLinks);
        if (view == AclFileAttributeView.class)
            return (V) new WindowsAclFileAttributeView(file, followLinks);
        if (view == FileOwnerAttributeView.class)
            return (V) new FileOwnerAttributeViewImpl(
                new WindowsAclFileAttributeView(file, followLinks));
        if (view == UserDefinedFileAttributeView.class)
            return (V) new WindowsUserDefinedFileAttributeView(file, followLinks);
        return (V) null;
    }

    @Override
    @SuppressWarnings("unchecked")
    public <A extends BasicFileAttributes> A readAttributes(Path file,
                                                            Class<A> type,
                                                            LinkOption... options)
        throws IOException
    {
        Class<? extends BasicFileAttributeView> view;
        if (type == BasicFileAttributes.class)
            view = BasicFileAttributeView.class;
        else if (type == DosFileAttributes.class)
            view = DosFileAttributeView.class;
        else if (type == null)
            throw new NullPointerException();
        else
            throw new UnsupportedOperationException();
        return (A) getFileAttributeView(file, view, options).readAttributes();
    }

    @Override
    public DynamicFileAttributeView getFileAttributeView(Path obj, String name, LinkOption... options) {
        WindowsPath file = WindowsPath.toWindowsPath(obj);
        boolean followLinks = Util.followLinks(options);
        if (name.equals("basic"))
            return WindowsFileAttributeViews.createBasicView(file, followLinks);
        if (name.equals("dos"))
            return WindowsFileAttributeViews.createDosView(file, followLinks);
        if (name.equals("acl"))
            return new WindowsAclFileAttributeView(file, followLinks);
        if (name.equals("owner"))
            return new FileOwnerAttributeViewImpl(
                new WindowsAclFileAttributeView(file, followLinks));
        if (name.equals("user"))
            return new WindowsUserDefinedFileAttributeView(file, followLinks);
        return null;
    }

    @Override
    public SeekableByteChannel newByteChannel(Path obj,
                                              Set<? extends OpenOption> options,
                                              FileAttribute<?>... attrs)
         throws IOException
    {
        WindowsPath file = WindowsPath.toWindowsPath(obj);
        WindowsSecurityDescriptor sd =
            WindowsSecurityDescriptor.fromAttribute(attrs);
        try {
            return WindowsChannelFactory
                .newFileChannel(file.getPathForWin32Calls(),
                                file.getPathForPermissionCheck(),
                                options,
                                sd.address());
        } catch (WindowsException x) {
            x.rethrowAsIOException(file);
            return null;  // keep compiler happy
        } finally {
            sd.release();
        }
    }

    @Override
    boolean implDelete(Path obj, boolean failIfNotExists) throws IOException {
        WindowsPath file = WindowsPath.toWindowsPath(obj);
        file.checkDelete();

        WindowsFileAttributes attrs = null;
        try {
             // need to know if file is a directory or junction
             attrs = WindowsFileAttributes.get(file, false);
             if (attrs.isDirectory() || attrs.isDirectoryLink()) {
                RemoveDirectory(file.getPathForWin32Calls());
             } else {
                DeleteFile(file.getPathForWin32Calls());
             }
             return true;
        } catch (WindowsException x) {

            // no-op if file does not exist
            if (!failIfNotExists &&
                (x.lastError() == ERROR_FILE_NOT_FOUND ||
                 x.lastError() == ERROR_PATH_NOT_FOUND)) return false;

            if (attrs != null && attrs.isDirectory()) {
                // ERROR_ALREADY_EXISTS is returned when attempting to delete
                // non-empty directory on SAMBA servers.
                if (x.lastError() == ERROR_DIR_NOT_EMPTY ||
                    x.lastError() == ERROR_ALREADY_EXISTS)
                {
                    throw new DirectoryNotEmptyException(
                        file.getPathForExceptionMessage());
                }
            }
            x.rethrowAsIOException(file);
            return false;
        }
    }

    @Override
    public void copy(Path source, Path target, CopyOption... options)
        throws IOException
    {
        WindowsFileCopy.copy(WindowsPath.toWindowsPath(source),
                             WindowsPath.toWindowsPath(target),
                             options);
    }

    @Override
    public void move(Path source, Path target, CopyOption... options)
        throws IOException
    {
        WindowsFileCopy.move(WindowsPath.toWindowsPath(source),
                             WindowsPath.toWindowsPath(target),
                             options);
    }

    
Checks the file security against desired access.
/** * Checks the file security against desired access. */
private static boolean hasDesiredAccess(WindowsPath file, int rights) throws IOException { // read security descriptor containing ACL (symlinks are followed) boolean hasRights = false; String target = WindowsLinkSupport.getFinalPath(file, true); NativeBuffer aclBuffer = WindowsAclFileAttributeView .getFileSecurity(target, DACL_SECURITY_INFORMATION | OWNER_SECURITY_INFORMATION | GROUP_SECURITY_INFORMATION); try { hasRights = checkAccessMask(aclBuffer.address(), rights, FILE_GENERIC_READ, FILE_GENERIC_WRITE, FILE_GENERIC_EXECUTE, FILE_ALL_ACCESS); } catch (WindowsException exc) { exc.rethrowAsIOException(file); } finally { aclBuffer.release(); } return hasRights; }
Checks if the given file(or directory) exists and is readable.
/** * Checks if the given file(or directory) exists and is readable. */
private void checkReadAccess(WindowsPath file) throws IOException { try { Set<OpenOption> opts = Collections.emptySet(); FileChannel fc = WindowsChannelFactory .newFileChannel(file.getPathForWin32Calls(), file.getPathForPermissionCheck(), opts, 0L); fc.close(); } catch (WindowsException exc) { // Windows errors are very inconsistent when the file is a directory // (ERROR_PATH_NOT_FOUND returned for root directories for example) // so we retry by attempting to open it as a directory. try { new WindowsDirectoryStream(file, null).close(); } catch (IOException ioe) { // translate and throw original exception exc.rethrowAsIOException(file); } } } @Override public void checkAccess(Path obj, AccessMode... modes) throws IOException { WindowsPath file = WindowsPath.toWindowsPath(obj); boolean r = false; boolean w = false; boolean x = false; for (AccessMode mode: modes) { switch (mode) { case READ : r = true; break; case WRITE : w = true; break; case EXECUTE : x = true; break; default: throw new AssertionError("Should not get here"); } } // special-case read access to avoid needing to determine effective // access to file; default if modes not specified if (!w && !x) { checkReadAccess(file); return; } int mask = 0; if (r) { file.checkRead(); mask |= FILE_READ_DATA; } if (w) { file.checkWrite(); mask |= FILE_WRITE_DATA; } if (x) { SecurityManager sm = System.getSecurityManager(); if (sm != null) sm.checkExec(file.getPathForPermissionCheck()); mask |= FILE_EXECUTE; } if (!hasDesiredAccess(file, mask)) throw new AccessDeniedException( file.getPathForExceptionMessage(), null, "Permissions does not allow requested access"); // for write access we need to check if the DOS readonly attribute // and if the volume is read-only if (w) { try { WindowsFileAttributes attrs = WindowsFileAttributes.get(file, true); if (!attrs.isDirectory() && attrs.isReadOnly()) throw new AccessDeniedException( file.getPathForExceptionMessage(), null, "DOS readonly attribute is set"); } catch (WindowsException exc) { exc.rethrowAsIOException(file); } if (WindowsFileStore.create(file).isReadOnly()) { throw new AccessDeniedException( file.getPathForExceptionMessage(), null, "Read-only file system"); } } } @Override public boolean isSameFile(Path obj1, Path obj2) throws IOException { WindowsPath file1 = WindowsPath.toWindowsPath(obj1); if (file1.equals(obj2)) return true; if (obj2 == null) throw new NullPointerException(); if (!(obj2 instanceof WindowsPath)) return false; WindowsPath file2 = (WindowsPath)obj2; // check security manager access to both files file1.checkRead(); file2.checkRead(); // open both files and see if they are the same long h1 = 0L; try { h1 = file1.openForReadAttributeAccess(true); } catch (WindowsException x) { x.rethrowAsIOException(file1); } try { WindowsFileAttributes attrs1 = null; try { attrs1 = WindowsFileAttributes.readAttributes(h1); } catch (WindowsException x) { x.rethrowAsIOException(file1); } long h2 = 0L; try { h2 = file2.openForReadAttributeAccess(true); } catch (WindowsException x) { x.rethrowAsIOException(file2); } try { WindowsFileAttributes attrs2 = null; try { attrs2 = WindowsFileAttributes.readAttributes(h2); } catch (WindowsException x) { x.rethrowAsIOException(file2); } return WindowsFileAttributes.isSameFile(attrs1, attrs2); } finally { CloseHandle(h2); } } finally { CloseHandle(h1); } } @Override public boolean isHidden(Path obj) throws IOException { WindowsPath file = WindowsPath.toWindowsPath(obj); file.checkRead(); WindowsFileAttributes attrs = null; try { attrs = WindowsFileAttributes.get(file, true); } catch (WindowsException x) { x.rethrowAsIOException(file); } // DOS hidden attribute not meaningful when set on directories if (attrs.isDirectory()) return false; return attrs.isHidden(); } @Override public FileStore getFileStore(Path obj) throws IOException { WindowsPath file = WindowsPath.toWindowsPath(obj); SecurityManager sm = System.getSecurityManager(); if (sm != null) { sm.checkPermission(new RuntimePermission("getFileStoreAttributes")); file.checkRead(); } return WindowsFileStore.create(file); } @Override public void createDirectory(Path obj, FileAttribute<?>... attrs) throws IOException { WindowsPath dir = WindowsPath.toWindowsPath(obj); dir.checkWrite(); WindowsSecurityDescriptor sd = WindowsSecurityDescriptor.fromAttribute(attrs); try { CreateDirectory(dir.getPathForWin32Calls(), sd.address()); } catch (WindowsException x) { // convert ERROR_ACCESS_DENIED to FileAlreadyExistsException if we can // verify that the directory exists if (x.lastError() == ERROR_ACCESS_DENIED) { try { if (WindowsFileAttributes.get(dir, false).isDirectory()) throw new FileAlreadyExistsException(dir.toString()); } catch (WindowsException ignore) { } } x.rethrowAsIOException(dir); } finally { sd.release(); } } @Override public DirectoryStream<Path> newDirectoryStream(Path obj, DirectoryStream.Filter<? super Path> filter) throws IOException { WindowsPath dir = WindowsPath.toWindowsPath(obj); dir.checkRead(); if (filter == null) throw new NullPointerException(); return new WindowsDirectoryStream(dir, filter); } @Override public void createSymbolicLink(Path obj1, Path obj2, FileAttribute<?>... attrs) throws IOException { WindowsPath link = WindowsPath.toWindowsPath(obj1); WindowsPath target = WindowsPath.toWindowsPath(obj2); // no attributes allowed if (attrs.length > 0) { WindowsSecurityDescriptor.fromAttribute(attrs); // may throw NPE or UOE throw new UnsupportedOperationException("Initial file attributes" + "not supported when creating symbolic link"); } // permission check SecurityManager sm = System.getSecurityManager(); if (sm != null) { sm.checkPermission(new LinkPermission("symbolic")); link.checkWrite(); } /** * Throw I/O exception for the drive-relative case because Windows * creates a link with the resolved target for this case. */ if (target.type() == WindowsPathType.DRIVE_RELATIVE) { throw new IOException("Cannot create symbolic link to working directory relative target"); } /* * Windows treats symbolic links to directories differently than it * does to other file types. For that reason we need to check if the * target is a directory (or a directory junction). */ WindowsPath resolvedTarget; if (target.type() == WindowsPathType.RELATIVE) { WindowsPath parent = link.getParent(); resolvedTarget = (parent == null) ? target : parent.resolve(target); } else { resolvedTarget = link.resolve(target); } int flags = 0; try { WindowsFileAttributes wattrs = WindowsFileAttributes.get(resolvedTarget, false); if (wattrs.isDirectory() || wattrs.isDirectoryLink()) flags |= SYMBOLIC_LINK_FLAG_DIRECTORY; } catch (WindowsException x) { // unable to access target so assume target is not a directory } // create the link try { CreateSymbolicLink(link.getPathForWin32Calls(), WindowsPath.addPrefixIfNeeded(target.toString()), flags); } catch (WindowsException x) { if (x.lastError() == ERROR_INVALID_REPARSE_DATA) { x.rethrowAsIOException(link, target); } else { x.rethrowAsIOException(link); } } } @Override public void createLink(Path obj1, Path obj2) throws IOException { WindowsPath link = WindowsPath.toWindowsPath(obj1); WindowsPath existing = WindowsPath.toWindowsPath(obj2); // permission check SecurityManager sm = System.getSecurityManager(); if (sm != null) { sm.checkPermission(new LinkPermission("hard")); link.checkWrite(); existing.checkWrite(); } // create hard link try { CreateHardLink(link.getPathForWin32Calls(), existing.getPathForWin32Calls()); } catch (WindowsException x) { x.rethrowAsIOException(link, existing); } } @Override public Path readSymbolicLink(Path obj1) throws IOException { WindowsPath link = WindowsPath.toWindowsPath(obj1); WindowsFileSystem fs = link.getFileSystem(); // permission check SecurityManager sm = System.getSecurityManager(); if (sm != null) { FilePermission perm = new FilePermission(link.getPathForPermissionCheck(), SecurityConstants.FILE_READLINK_ACTION); sm.checkPermission(perm); } String target = WindowsLinkSupport.readLink(link); return WindowsPath.createFromNormalizedPath(fs, target); } }