/*

 * Copyright (c) 2013, 2019, 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.

 *

 * 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 jdk.test.lib;

import java.io.File;

import java.io.IOException;

import java.io.RandomAccessFile;

import java.util.regex.Pattern;

import java.security.AccessController;

import java.security.PrivilegedAction;

import java.security.PrivilegedActionException;

import java.security.PrivilegedExceptionAction;

public class Platform {

    public  static final String vmName      = privilegedGetProperty("java.vm.name");

    public  static final String vmInfo      = privilegedGetProperty("java.vm.info");

    private static final String osVersion   = privilegedGetProperty("os.version");

    private static       int osVersionMajor = -1;

    private static       int osVersionMinor = -1;

    private static final String osName      = privilegedGetProperty("os.name");

    private static final String dataModel   = privilegedGetProperty("sun.arch.data.model");

    private static final String vmVersion   = privilegedGetProperty("java.vm.version");

    private static final String jdkDebug    = privilegedGetProperty("jdk.debug");

    private static final String osArch      = privilegedGetProperty("os.arch");

    private static final String userName    = privilegedGetProperty("user.name");

    private static final String compiler    = privilegedGetProperty("sun.management.compiler");

    private static String privilegedGetProperty(String key) {

        return AccessController.doPrivileged((

                PrivilegedAction<String>) () -> System.getProperty(key));

    }

    public static boolean isClient() {

        return vmName.endsWith(" Client VM");

    }

    public static boolean isServer() {

        return vmName.endsWith(" Server VM");

    }

    public static boolean isGraal() {

        return vmName.endsWith(" Graal VM");

    }

    public static boolean isZero() {

        return vmName.endsWith(" Zero VM");

    }

    public static boolean isMinimal() {

        return vmName.endsWith(" Minimal VM");

    }

    public static boolean isEmbedded() {

        return vmName.contains("Embedded");

    }

    public static boolean isEmulatedClient() {

        return vmInfo.contains(" emulated-client");

    }

    public static boolean isTieredSupported() {

        return compiler.contains("Tiered Compilers");

    }

    public static boolean isInt() {

        return vmInfo.contains("interpreted");

    }

    public static boolean isMixed() {

        return vmInfo.contains("mixed");

    }

    public static boolean isComp() {

        return vmInfo.contains("compiled");

    }

    public static boolean is32bit() {

        return dataModel.equals("32");

    }

    public static boolean is64bit() {

        return dataModel.equals("64");

    }

    public static boolean isAix() {

        return isOs("aix");

    }

    public static boolean isLinux() {

        return isOs("linux");

    }

    public static boolean isOSX() {

        return isOs("mac");

    }

    public static boolean isSolaris() {

        return isOs("sunos");

    }

    public static boolean isWindows() {

        return isOs("win");

    }

    private static boolean isOs(String osname) {

        return osName.toLowerCase().startsWith(osname.toLowerCase());

    }

    public static String getOsName() {

        return osName;

    }

    // Os version support.

    private static void init_version() {

        String[] osVersionTokens = osVersion.split("\\.");

        try {

            if (osVersionTokens.length > 0) {

                osVersionMajor = Integer.parseInt(osVersionTokens[0]);

                if (osVersionTokens.length > 1) {

                    osVersionMinor = Integer.parseInt(osVersionTokens[1]);

                }

            }

        } catch (NumberFormatException e) {

            osVersionMajor = osVersionMinor = 0;

        }

    }

    public static String getOsVersion() {

        return osVersion;

    }

    // Returns major version number from os.version system property.

    // E.g. 5 on Solaris 10 and 3 on SLES 11.3 (for the linux kernel version).

    public static int getOsVersionMajor() {

        if (osVersionMajor == -1) init_version();

        return osVersionMajor;

    }

    // Returns minor version number from os.version system property.

    // E.g. 10 on Solaris 10 and 0 on SLES 11.3 (for the linux kernel version).

    public static int getOsVersionMinor() {

        if (osVersionMinor == -1) init_version();

        return osVersionMinor;

    }

    public static boolean isDebugBuild() {

        return (jdkDebug.toLowerCase().contains("debug"));

    }

    public static boolean isSlowDebugBuild() {

        return (jdkDebug.toLowerCase().equals("slowdebug"));

    }

    public static boolean isFastDebugBuild() {

        return (jdkDebug.toLowerCase().equals("fastdebug"));

    }

    public static String getVMVersion() {

        return vmVersion;

    }

    public static boolean isAArch64() {

        return isArch("aarch64");

    }

    public static boolean isARM() {

        return isArch("arm.*");

    }

    public static boolean isPPC() {

        return isArch("ppc.*");

    }

    // Returns true for IBM z System running linux.

    public static boolean isS390x() {

        return isArch("s390.*") || isArch("s/390.*") || isArch("zArch_64");

    }

    // Returns true for sparc and sparcv9.

    public static boolean isSparc() {

        return isArch("sparc.*");

    }

    public static boolean isX64() {

        // On OSX it's 'x86_64' and on other (Linux, Windows and Solaris) platforms it's 'amd64'

        return isArch("(amd64)|(x86_64)");

    }

    public static boolean isX86() {

        // On Linux it's 'i386', Windows 'x86' without '_64' suffix.

        return isArch("(i386)|(x86(?!_64))");

    }

    public static String getOsArch() {

        return osArch;

    }

    /**

     * Return a boolean for whether SA and jhsdb are ported/available

     * on this platform.

     */

    public static boolean hasSA() {

        if (isAix()) {

            return false; // SA not implemented.

        } else if (isLinux()) {

            if (isS390x() || isARM()) {

                return false; // SA not implemented.

            }

        }

        // Other platforms expected to work:

        return true;

    }

    /**

     * Return a boolean for whether we expect to be able to attach

     * the SA to our own processes on this system.  This requires

     * that SA is ported/available on this platform.

     */

    public static boolean shouldSAAttach() throws IOException {

        if (!hasSA()) return false;

        if (isLinux()) {

            return canPtraceAttachLinux();

        } else if (isOSX()) {

            return canAttachOSX();

        } else {

            // Other platforms expected to work:

            return true;

        }

    }

    /**

     * On Linux, first check the SELinux boolean "deny_ptrace" and return false

     * as we expect to be denied if that is "1".  Then expect permission to attach

     * if we are root, so return true.  Then return false for an expected denial

     * if "ptrace_scope" is 1, and true otherwise.

     */

    private static boolean canPtraceAttachLinux() throws IOException {

        // SELinux deny_ptrace:

        File deny_ptrace = new File("/sys/fs/selinux/booleans/deny_ptrace");

        if (deny_ptrace.exists()) {

            try (RandomAccessFile file = AccessController.doPrivileged(

                    (PrivilegedExceptionAction<RandomAccessFile>) () -> new RandomAccessFile(deny_ptrace, "r"))) {

                if (file.readByte() != '0') {

                    return false;

                }

            } catch (PrivilegedActionException e) {

                @SuppressWarnings("unchecked")

                IOException t = (IOException) e.getException();

                throw t;

            }

        }

        // YAMA enhanced security ptrace_scope:

        // 0 - a process can PTRACE_ATTACH to any other process running under the same uid

        // 1 - restricted ptrace: a process must be a children of the inferior or user is root

        // 2 - only processes with CAP_SYS_PTRACE may use ptrace or user is root

        // 3 - no attach: no processes may use ptrace with PTRACE_ATTACH

        File ptrace_scope = new File("/proc/sys/kernel/yama/ptrace_scope");

        if (ptrace_scope.exists()) {

            try (RandomAccessFile file = AccessController.doPrivileged(

                    (PrivilegedExceptionAction<RandomAccessFile>) () -> new RandomAccessFile(ptrace_scope, "r"))) {

                byte yama_scope = file.readByte();

                if (yama_scope == '3') {

                    return false;

                }

                if (!userName.equals("root") && yama_scope != '0') {

                    return false;

                }

            } catch (PrivilegedActionException e) {

                @SuppressWarnings("unchecked")

                IOException t = (IOException) e.getException();

                throw t;

            }

        }

        // Otherwise expect to be permitted:

        return true;

    }

    /**

     * On OSX, expect permission to attach only if we are root.

     */

    private static boolean canAttachOSX() {

        return userName.equals("root");

    }

    private static boolean isArch(String archnameRE) {

        return Pattern.compile(archnameRE, Pattern.CASE_INSENSITIVE)

                      .matcher(osArch)

                      .matches();

    }

    /**

     * Returns file extension of shared library, e.g. "so" on linux, "dll" on windows.

     * @return file extension

     */

    public static String sharedLibraryExt() {

        if (isWindows()) {

            return "dll";

        } else if (isOSX()) {

            return "dylib";

        } else {

            return "so";

        }

    }

    /*

     * Returns name of system variable containing paths to shared native libraries.

     */

    public static String sharedLibraryPathVariableName() {

        if (isWindows()) {

            return "PATH";

        } else if (isOSX()) {

            return "DYLD_LIBRARY_PATH";

        } else if (isAix()) {

            return "LIBPATH";

        } else {

            return "LD_LIBRARY_PATH";

        }

    }

    public static boolean isDefaultCDSArchiveSupported() {

        return (is64bit()  &&

                isServer() &&

                (isLinux()   ||

                 isOSX()     ||

                 isSolaris() ||

                 isWindows()) &&

                !isZero()    &&

                !isMinimal() &&

                !isAArch64() &&

                !isARM());

    }

    /*

     * This should match the #if condition in ClassListParser::load_class_from_source().

     */

    public static boolean areCustomLoadersSupportedForCDS() {

        return (is64bit() && (isLinux() || isSolaris() || isOSX()));

    }

}