/*

 * Copyright (c) 2009, 2012, 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

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 */

package sun.nio.ch.sctp;

import java.net.SocketAddress;

import java.net.InetSocketAddress;

import java.net.InetAddress;

import java.io.FileDescriptor;

import java.io.IOException;

import java.util.Collections;

import java.util.Set;

import java.util.HashSet;

import java.nio.channels.SelectionKey;

import java.nio.channels.ClosedChannelException;

import java.nio.channels.NotYetBoundException;

import java.nio.channels.spi.SelectorProvider;

import com.sun.nio.sctp.IllegalUnbindException;

import com.sun.nio.sctp.SctpChannel;

import com.sun.nio.sctp.SctpServerChannel;

import com.sun.nio.sctp.SctpSocketOption;

import com.sun.nio.sctp.SctpStandardSocketOptions;

import sun.nio.ch.DirectBuffer;

import sun.nio.ch.NativeThread;

import sun.nio.ch.IOStatus;

import sun.nio.ch.IOUtil;

import sun.nio.ch.Net;

import sun.nio.ch.PollArrayWrapper;

import sun.nio.ch.SelChImpl;

import sun.nio.ch.SelectionKeyImpl;

import sun.nio.ch.Util;

/**

 * An implementation of SctpServerChannel

 */

public class SctpServerChannelImpl extends SctpServerChannel

    implements SelChImpl

{

    private final FileDescriptor fd;

    private final int fdVal;

    /* IDs of native thread doing accept, for signalling */

    private volatile long thread = 0;

    /* Lock held by thread currently blocked in this channel */

    private final Object lock = new Object();

    /* Lock held by any thread that modifies the state fields declared below

     * DO NOT invoke a blocking I/O operation while holding this lock! */

    private final Object stateLock = new Object();

    private enum ChannelState {

        UNINITIALIZED,

        INUSE,

        KILLPENDING,

        KILLED,

    }

    /* -- The following fields are protected by stateLock -- */

    private ChannelState state = ChannelState.UNINITIALIZED;

    /* Binding: Once bound the port will remain constant. */

    int port = -1;

    private HashSet<InetSocketAddress> localAddresses = new HashSet<InetSocketAddress>();

    /* Has the channel been bound to the wildcard address */

    private boolean wildcard; /* false */

    /* -- End of fields protected by stateLock -- */

    /**

     * Initializes a new instance of this class.

     */

    public SctpServerChannelImpl(SelectorProvider provider)

            throws IOException {

        //TODO: update provider remove public modifier

        super(provider);

        this.fd = SctpNet.socket(true);

        this.fdVal = IOUtil.fdVal(fd);

        this.state = ChannelState.INUSE;

    }

    @Override

    public SctpServerChannel bind(SocketAddress local, int backlog)

            throws IOException {

        synchronized (lock) {

            synchronized (stateLock) {

                if (!isOpen())

                    throw new ClosedChannelException();

                if (isBound())

                    SctpNet.throwAlreadyBoundException();

                InetSocketAddress isa = (local == null) ?

                    new InetSocketAddress(0) : Net.checkAddress(local);

                SecurityManager sm = System.getSecurityManager();

                if (sm != null)

                    sm.checkListen(isa.getPort());

                Net.bind(fd, isa.getAddress(), isa.getPort());

                InetSocketAddress boundIsa = Net.localAddress(fd);

                port = boundIsa.getPort();

                localAddresses.add(isa);

                    if (isa.getAddress().isAnyLocalAddress())

                        wildcard = true;

                SctpNet.listen(fdVal, backlog < 1 ? 50 : backlog);

            }

        }

        return this;

    }

    @Override

    public SctpServerChannel bindAddress(InetAddress address)

            throws IOException {

        return bindUnbindAddress(address, true);

    }

    @Override

    public SctpServerChannel unbindAddress(InetAddress address)

            throws IOException {

        return bindUnbindAddress(address, false);

    }

    private SctpServerChannel bindUnbindAddress(InetAddress address, boolean add)

            throws IOException {

        if (address == null)

            throw new IllegalArgumentException();

        synchronized (lock) {

            synchronized (stateLock) {

                if (!isOpen())

                    throw new ClosedChannelException();

                if (!isBound())

                    throw new NotYetBoundException();

                if (wildcard)

                    throw new IllegalStateException(

                            "Cannot add or remove addresses from a channel that is bound to the wildcard address");

                if (address.isAnyLocalAddress())

                    throw new IllegalArgumentException(

                            "Cannot add or remove the wildcard address");

                if (add) {

                    for (InetSocketAddress addr : localAddresses) {

                        if (addr.getAddress().equals(address)) {

                            SctpNet.throwAlreadyBoundException();

                        }

                    }

                } else { /*removing */

                    /* Verify that there is more than one address

                     * and that address is already bound */

                    if (localAddresses.size() <= 1)

                        throw new IllegalUnbindException("Cannot remove address from a channel with only one address bound");

                    boolean foundAddress = false;

                    for (InetSocketAddress addr : localAddresses) {

                        if (addr.getAddress().equals(address)) {

                            foundAddress = true;

                            break;

                        }

                    }

                    if (!foundAddress )

                        throw new IllegalUnbindException("Cannot remove address from a channel that is not bound to that address");

                }

                SctpNet.bindx(fdVal, new InetAddress[]{address}, port, add);

                /* Update our internal Set to reflect the addition/removal */

                if (add)

                    localAddresses.add(new InetSocketAddress(address, port));

                else {

                    for (InetSocketAddress addr : localAddresses) {

                        if (addr.getAddress().equals(address)) {

                            localAddresses.remove(addr);

                            break;

                        }

                    }

                }

            }

        }

        return this;

    }

    private boolean isBound() {

        synchronized (stateLock) {

            return port == -1 ? false : true;

        }

    }

    private void acceptCleanup() throws IOException {

        synchronized (stateLock) {

            thread = 0;

            if (state == ChannelState.KILLPENDING)

                kill();

        }

    }

    @Override

    public SctpChannel accept() throws IOException {

        synchronized (lock) {

            if (!isOpen())

                throw new ClosedChannelException();

            if (!isBound())

                throw new NotYetBoundException();

            SctpChannel sc = null;

            int n = 0;

            FileDescriptor newfd = new FileDescriptor();

            InetSocketAddress[] isaa = new InetSocketAddress[1];

            try {

                begin();

                if (!isOpen())

                    return null;

                thread = NativeThread.current();

                for (;;) {

                    n = accept0(fd, newfd, isaa);

                    if ((n == IOStatus.INTERRUPTED) && isOpen())

                        continue;

                    break;

                }

            } finally {

                acceptCleanup();

                end(n > 0);

                assert IOStatus.check(n);

            }

            if (n < 1)

                return null;

            IOUtil.configureBlocking(newfd, true);

            InetSocketAddress isa = isaa[0];

            sc = new SctpChannelImpl(provider(), newfd);

            SecurityManager sm = System.getSecurityManager();

            if (sm != null)

                sm.checkAccept(isa.getAddress().getHostAddress(),

                               isa.getPort());

            return sc;

        }

    }

    @Override

    protected void implConfigureBlocking(boolean block) throws IOException {

        IOUtil.configureBlocking(fd, block);

    }

    @Override

    public void implCloseSelectableChannel() throws IOException {

        synchronized (stateLock) {

            SctpNet.preClose(fdVal);

            if (thread != 0)

                NativeThread.signal(thread);

            if (!isRegistered())

                kill();

        }

    }

    @Override

    public void kill() throws IOException {

        synchronized (stateLock) {

            if (state == ChannelState.KILLED)

                return;

            if (state == ChannelState.UNINITIALIZED) {

                state = ChannelState.KILLED;

                return;

            }

            assert !isOpen() && !isRegistered();

            // Postpone the kill if there is a thread in accept

            if (thread == 0) {

                SctpNet.close(fdVal);

                state = ChannelState.KILLED;

            } else {

                state = ChannelState.KILLPENDING;

            }

        }

    }

    @Override

    public FileDescriptor getFD() {

        return fd;

    }

    @Override

    public int getFDVal() {

        return fdVal;

    }

    /**

     * Translates native poll revent ops into a ready operation ops

     */

    private boolean translateReadyOps(int ops, int initialOps,

                                     SelectionKeyImpl sk) {

        int intOps = sk.nioInterestOps();

        int oldOps = sk.nioReadyOps();

        int newOps = initialOps;

            /* This should only happen if this channel is pre-closed while a

             * selection operation is in progress

             * ## Throw an error if this channel has not been pre-closed */

            return false;

        }

            newOps = intOps;

            sk.nioReadyOps(newOps);

            return (newOps & ~oldOps) != 0;

        }

            ((intOps & SelectionKey.OP_ACCEPT) != 0))

                newOps |= SelectionKey.OP_ACCEPT;

        sk.nioReadyOps(newOps);

        return (newOps & ~oldOps) != 0;

    }

    @Override

    public boolean translateAndUpdateReadyOps(int ops, SelectionKeyImpl sk) {

        return translateReadyOps(ops, sk.nioReadyOps(), sk);

    }

    @Override

    public boolean translateAndSetReadyOps(int ops, SelectionKeyImpl sk) {

        return translateReadyOps(ops, 0, sk);

    }

    @Override

    public void translateAndSetInterestOps(int ops, SelectionKeyImpl sk) {

        int newOps = 0;

        /* Translate ops */

        if ((ops & SelectionKey.OP_ACCEPT) != 0)

        /* Place ops into pollfd array */

        sk.selector.putEventOps(sk, newOps);

    }

    @Override

    public <T> SctpServerChannel setOption(SctpSocketOption<T> name, T value)

            throws IOException {

        if (name == null)

            throw new NullPointerException();

        if (!supportedOptions().contains(name))

            throw new UnsupportedOperationException("'" + name + "' not supported");

        synchronized (stateLock) {

            if (!isOpen())

                throw new ClosedChannelException();

            SctpNet.setSocketOption(fdVal, name, value, 0 /*oneToOne*/);

            return this;

        }

    }

    @Override

    @SuppressWarnings("unchecked")

    public <T> T getOption(SctpSocketOption<T> name) throws IOException {

        if (name == null)

            throw new NullPointerException();

        if (!supportedOptions().contains(name))

            throw new UnsupportedOperationException("'" + name + "' not supported");

        synchronized (stateLock) {

            if (!isOpen())

                throw new ClosedChannelException();

            return (T) SctpNet.getSocketOption(fdVal, name, 0 /*oneToOne*/);

        }

    }

    private static class DefaultOptionsHolder {

        static final Set<SctpSocketOption<?>> defaultOptions = defaultOptions();

        private static Set<SctpSocketOption<?>> defaultOptions() {

            HashSet<SctpSocketOption<?>> set = new HashSet<SctpSocketOption<?>>(1);

            set.add(SctpStandardSocketOptions.SCTP_INIT_MAXSTREAMS);

            return Collections.unmodifiableSet(set);

        }

    }

    @Override

    public final Set<SctpSocketOption<?>> supportedOptions() {

        return DefaultOptionsHolder.defaultOptions;

    }

    @Override

    public Set<SocketAddress> getAllLocalAddresses()

            throws IOException {

        synchronized (stateLock) {

            if (!isOpen())

                throw new ClosedChannelException();

            if (!isBound())

                return Collections.emptySet();

            return SctpNet.getLocalAddresses(fdVal);

        }

    }

    /* Native */

    private static native void initIDs();

    private static native int accept0(FileDescriptor ssfd,

        FileDescriptor newfd, InetSocketAddress[] isaa) throws IOException;

    static {

        IOUtil.load();   // loads nio & net native libraries

        java.security.AccessController.doPrivileged(

            new java.security.PrivilegedAction<Void>() {

                public Void run() {

                    System.loadLibrary("sctp");

                    return null;

                }

            });

        initIDs();

    }

}