/*

 * Copyright (c) 2018, 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.net.util;

import java.io.IOException;

import java.lang.reflect.Constructor;

import java.net.InetSocketAddress;

import java.security.AccessController;

import java.security.PrivilegedAction;

import java.security.Security;

public final class SocketExceptions {

    private SocketExceptions() {}

    /**

     * Security or system property which specifies categories of

     * (potentially sensitive) information that may be included

     * in exception text. This class only defines one category:

     * "hostInfo" which represents the hostname and port number

     * of the remote peer relating to a socket exception.

     * The property value is a comma separated list of

     * case insignificant category names.

     */

    private static final String enhancedTextPropname = "jdk.includeInExceptions";

    private static final boolean enhancedExceptionText = initTextProp();

    private static boolean initTextProp() {

        return AccessController.doPrivileged(new PrivilegedAction<Boolean>() {

            public Boolean run() {

                String val = System.getProperty(enhancedTextPropname);

                if (val == null) {

                    val = Security.getProperty(enhancedTextPropname);

                    if (val == null)

                        return false;

                }

                String[] tokens = val.split(",");

                for (String token : tokens) {

                    if (token.equalsIgnoreCase("hostinfo"))

                        return true;

                }

                return false;

            }

        });

    }

    /**

     * Utility which takes an exception and returns either the same exception

     * or a new exception of the same type with the same stack trace

     * and detail message enhanced with addressing information from the

     * given InetSocketAddress.

     *

     * If the system/security property "jdk.net.enhanceExceptionText" is not

     * set or is false, then the original exception is returned.

     *

     * Only specific IOException subtypes are supported.

     */

    public static IOException of(IOException e, InetSocketAddress address) {

        if (!enhancedExceptionText || address == null)

            return e;

        int port = address.getPort();

        String host = address.getHostString();

        StringBuilder sb = new StringBuilder();

        sb.append(e.getMessage());

        sb.append(": ");

        sb.append(host);

        sb.append(':');

        sb.append(Integer.toString(port));

        String enhancedMsg = sb.toString();

        return create(e, enhancedMsg);

    }

    // return a new instance of the same type with the given detail

    // msg, or if the type doesn't support detail msgs, return given

    // instance.

    private static IOException create(IOException e, String msg) {

        return AccessController.doPrivileged(new PrivilegedAction<IOException>() {

            public IOException run() {

                try {

                    Class<?> clazz = e.getClass();

                    Constructor<?> ctor = clazz.getConstructor(String.class);

                    IOException e1 = (IOException)(ctor.newInstance(msg));

                    e1.setStackTrace(e.getStackTrace());

                    return e1;

                } catch (Exception e0) {

                    // Some eg AsynchronousCloseException have no detail msg

                    return e;

                }

            }

        });

    }

}