/*

 * Copyright (c) 2005, 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.tools.attach;

import com.sun.tools.attach.VirtualMachine;

import com.sun.tools.attach.VirtualMachineDescriptor;

import com.sun.tools.attach.AttachNotSupportedException;

import java.util.ArrayList;

import java.util.List;

import java.io.IOException;

import java.net.InetAddress;

import java.net.UnknownHostException;

public class WindowsAttachProvider extends HotSpotAttachProvider {

    public WindowsAttachProvider() {

        String os = System.getProperty("os.name");

        if (os.startsWith("Windows 9") || os.equals("Windows Me")) {

            throw new RuntimeException(

                "This provider is not supported on this version of Windows");

        }

        String arch = System.getProperty("os.arch");

        if (!arch.equals("x86") && !arch.equals("amd64")) {

            throw new RuntimeException(

                "This provider is not supported on this processor architecture");

        }

    }

    public String name() {

        return "sun";

    }

    public String type() {

        return "windows";

    }

    public VirtualMachine attachVirtualMachine(String vmid)

        throws AttachNotSupportedException, IOException

    {

        checkAttachPermission();

        // AttachNotSupportedException will be thrown if the target VM can be determined

        // to be not attachable.

        testAttachable(vmid);

        return new WindowsVirtualMachine(this, vmid);

    }

    public List<VirtualMachineDescriptor> listVirtualMachines() {

        // If the temporary file system is secure then we use the default

        // implementation, otherwise we create a list of Windows processes.

        if (isTempPathSecure()) {

            return super.listVirtualMachines();

        } else {

            return listJavaProcesses();

        }

    }

    /**

     * Returns true if the temporary file system supports security

     */

    private static boolean isTempPathSecure() {

        if (!wasTempPathChecked) {

            synchronized (WindowsAttachProvider.class) {

                if (!wasTempPathChecked) {

                    // get the value of TMP/TEMP, ignoring UNC, and paths that

                    // aren't absolute

                    String temp = tempPath();

                    if ((temp != null) && (temp.length() >= 3) &&

                        (temp.charAt(1) == ':') && (temp.charAt(2) == '\\'))

                    {

                        // check if the volume supports security

                        long flags = volumeFlags(temp.substring(0, 3));

                        isTempPathSecure = ((flags & FS_PERSISTENT_ACLS) != 0);

                    }

                    wasTempPathChecked = true;

                }

            }

        }

        return isTempPathSecure;

    }

    // flag to indicate persistent ACLs are supported

    private static final long FS_PERSISTENT_ACLS = 0x8L;

    // indicates if we've checked the temporary file system

    private static volatile boolean wasTempPathChecked;

    // indicates if the temporary file system is secure (only valid when

    // wasTempPathChecked is true)

    private static boolean isTempPathSecure;

    // returns the value of TMP/TEMP

    private static native String tempPath();

    // returns the flags for the given volume

    private static native long volumeFlags(String volume);

    /**

     * Returns a list of virtual machine descriptors derived from an enumeration

     * of the process list.

     */

    private List<VirtualMachineDescriptor> listJavaProcesses() {

        // ensure that process status helper is loaded (psapi.dll)

        if (!isProcessStatusHelperInitialized) {

            synchronized (WindowsAttachProvider.class) {

                if (!isProcessStatusHelperInitialized) {

                    initializeProcessStatusHelper();

                    isProcessStatusHelperInitialized = true;

                }

            }

        }

        ArrayList<VirtualMachineDescriptor> list =

            new ArrayList<VirtualMachineDescriptor>();

        // Use localhost in the display name

        String host = "localhost";

        try {

            host = InetAddress.getLocalHost().getHostName();

        } catch (UnknownHostException uhe) {

            // ignore

        }

        // Enumerate all processes.

        // For those processes that have loaded a library named "jvm.dll"

        // then we attempt to attach. If we succeed then we have a 6.0+ VM.

        int processes[] = new int[1024];

        int count = enumProcesses(processes, processes.length);

        for (int i=0; i<count; i++) {

            if (isLibraryLoadedByProcess("jvm.dll", processes[i])) {

                String pid = Integer.toString(processes[i]);

                try {

                    new WindowsVirtualMachine(this, pid).detach();

                    // FIXME - for now we don't have an appropriate display

                    // name so we use pid@hostname

                    String name = pid + "@" + host;

                    list.add(new HotSpotVirtualMachineDescriptor(this, pid, name));

                } catch (AttachNotSupportedException x) {

                } catch (IOException ioe) {

                }

            }

        }

        return list;

    }

    // indicates if psapi.dll has been initialized

    private static volatile boolean isProcessStatusHelperInitialized;

    // loads psapi

    private static native void initializeProcessStatusHelper();

    // enumerates processes using psapi's EnumProcesses

    private static native int enumProcesses(int[] processes, int max);

    // indicates if a library of a given name has been loaded by a process

    private static native boolean isLibraryLoadedByProcess(String library,

                                                           int processId);

    // native functions in this library

    static {

        System.loadLibrary("attach");

    }

}