protocol/netconf-server/src/main/java/org/opendaylight/netconf/server/NetconfSubsystem.java

   1 /*
   2  * Copyright (c) 2023 PANTHEON.tech, s.r.o. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8 package org.opendaylight.netconf.server;
   9
  10 import static java.util.Objects.requireNonNull;
  11
  12 import io.netty.buffer.Unpooled;
  13 import io.netty.channel.ChannelHandlerContext;
  14 import io.netty.channel.ChannelInboundHandlerAdapter;
  15 import io.netty.channel.embedded.EmbeddedChannel;
  16 import io.netty.util.concurrent.GlobalEventExecutor;
  17 import java.net.InetSocketAddress;
  18 import java.nio.charset.StandardCharsets;
  19 import org.opendaylight.netconf.api.messages.NetconfHelloMessageAdditionalHeader;
  20 import org.opendaylight.netconf.shaded.sshd.common.io.IoInputStream;
  21 import org.opendaylight.netconf.shaded.sshd.common.io.IoOutputStream;
  22 import org.opendaylight.netconf.shaded.sshd.server.channel.ChannelDataReceiver;
  23 import org.opendaylight.netconf.shaded.sshd.server.channel.ChannelSession;
  24 import org.opendaylight.netconf.shaded.sshd.server.channel.ChannelSessionAware;
  25 import org.opendaylight.netconf.shaded.sshd.server.command.AbstractCommandSupport;
  26 import org.opendaylight.netconf.shaded.sshd.server.command.AsyncCommand;
  27 import org.opendaylight.netconf.transport.ssh.OutboundChannelHandler;
  28
  29 final class NetconfSubsystem extends AbstractCommandSupport
  30         implements AsyncCommand, ChannelSessionAware, ChannelDataReceiver {
  31     // FIXME: NETCONF-1106: do not use EmbeddedChannel here!
  32     private final EmbeddedChannel innerChannel = new EmbeddedChannel();
  33     private final ServerChannelInitializer channelInitializer;
  34
  35     NetconfSubsystem(final String name, final ServerChannelInitializer channelInitializer) {
  36         super(name, null);
  37         this.channelInitializer = requireNonNull(channelInitializer);
  38     }
  39
  40     @Override
  41     public void run() {
  42         // not used
  43     }
  44
  45     @Override
  46     public void setIoInputStream(final IoInputStream in) {
  47         // not used
  48     }
  49
  50     @Override
  51     public void setIoErrorStream(final IoOutputStream err) {
  52         // not used
  53     }
  54
  55     @Override
  56     public void setIoOutputStream(final IoOutputStream out) {
  57         /*
  58          * While NETCONF protocol handlers are designed to operate over Netty channel, the inner channel is used to
  59          * serve NETCONF over SSH.
  60          */
  61         // outbound packet handler, adding fist means it will be invoked last because of flow direction
  62         innerChannel.pipeline().addFirst(new OutboundChannelHandler(out));
  63
  64         // inner channel termination handler
  65         innerChannel.pipeline().addLast(
  66             new ChannelInboundHandlerAdapter() {
  67                 @Override
  68                 public void channelInactive(final ChannelHandlerContext ctx) {
  69                     onExit(0);
  70                 }
  71             });
  72
  73         // NETCONF protocol handlers
  74         channelInitializer.initialize(innerChannel, GlobalEventExecutor.INSTANCE.newPromise());
  75         // trigger negotiation flow
  76         innerChannel.pipeline().fireChannelActive();
  77         // set additional info for upcoming netconf session
  78         innerChannel.writeInbound(Unpooled.wrappedBuffer(getHelloAdditionalMessageBytes()));
  79     }
  80
  81     @Override
  82     public void setChannelSession(final ChannelSession channelSession) {
  83         /*
  84          * Inbound packets handler
  85          * NOTE: The channel data receiver require to be set within current method, so it could be handled
  86          * with subsequent logic of ChannelSession#prepareChannelCommand() where this method is executed from.
  87          */
  88         channelSession.setDataReceiver(this);
  89     }
  90
  91     @Override
  92     public int data(final ChannelSession channel, final byte[] buf, final int start, final int len) {
  93         // Do not propagate empty invocations
  94         if (len != 0) {
  95             innerChannel.writeInbound(Unpooled.copiedBuffer(buf, start, len));
  96         }
  97         return len;
  98     }
  99
 100     @Override
 101     public void close() {
 102         innerChannel.close();
 103     }
 104
 105     @Override
 106     protected void onExit(final int exitValue, final String exitMessage) {
 107         super.onExit(exitValue, exitMessage);
 108         innerChannel.close();
 109     }
 110
 111     private byte[] getHelloAdditionalMessageBytes() {
 112         final var session = getServerSession();
 113         final var address = (InetSocketAddress) session.getClientAddress();
 114         return new NetconfHelloMessageAdditionalHeader(session.getUsername(), address.getAddress().getHostAddress(),
 115             String.valueOf(address.getPort()), "ssh", "client")
 116             .toFormattedString().getBytes(StandardCharsets.UTF_8);
 117     }
 118 }