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
  28 final class NetconfSubsystem extends AbstractCommandSupport
  29         implements AsyncCommand, ChannelSessionAware, ChannelDataReceiver {
  30     // FIXME: NETCONF-1106: do not use EmbeddedChannel here!
  31     private final EmbeddedChannel innerChannel = new EmbeddedChannel();
  32     private final ServerChannelInitializer channelInitializer;
  33
  34     NetconfSubsystem(final String name, final ServerChannelInitializer channelInitializer) {
  35         super(name, null);
  36         this.channelInitializer = requireNonNull(channelInitializer);
  37     }
  38
  39     @Override
  40     public void run() {
  41         // not used
  42     }
  43
  44     @Override
  45     public void setIoInputStream(final IoInputStream in) {
  46         // not used
  47     }
  48
  49     @Override
  50     public void setIoErrorStream(final IoOutputStream err) {
  51         // not used
  52     }
  53
  54     @Override
  55     public void setIoOutputStream(final IoOutputStream out) {
  56         /*
  57          * While NETCONF protocol handlers are designed to operate over Netty channel, the inner channel is used to
  58          * serve NETCONF over SSH.
  59          */
  60         // outbound packet handler, adding fist means it will be invoked last because of flow direction
  61         innerChannel.pipeline().addFirst(new NetconfSubsystemOutboundChannelHandler(out));
  62
  63         // inner channel termination handler
  64         innerChannel.pipeline().addLast(
  65             new ChannelInboundHandlerAdapter() {
  66                 @Override
  67                 public void channelInactive(final ChannelHandlerContext ctx) {
  68                     onExit(0);
  69                 }
  70             });
  71
  72         // NETCONF protocol handlers
  73         channelInitializer.initialize(innerChannel, GlobalEventExecutor.INSTANCE.newPromise());
  74         // trigger negotiation flow
  75         innerChannel.pipeline().fireChannelActive();
  76         // set additional info for upcoming netconf session
  77         innerChannel.writeInbound(Unpooled.wrappedBuffer(getHelloAdditionalMessageBytes()));
  78     }
  79
  80     @Override
  81     public void setChannelSession(final ChannelSession channelSession) {
  82         /*
  83          * Inbound packets handler
  84          * NOTE: The channel data receiver require to be set within current method, so it could be handled
  85          * with subsequent logic of ChannelSession#prepareChannelCommand() where this method is executed from.
  86          */
  87         channelSession.setDataReceiver(this);
  88     }
  89
  90     @Override
  91     public int data(final ChannelSession channel, final byte[] buf, final int start, final int len) {
  92         // Do not propagate empty invocations
  93         if (len != 0) {
  94             innerChannel.writeInbound(Unpooled.copiedBuffer(buf, start, len));
  95         }
  96         return len;
  97     }
  98
  99     @Override
 100     public void close() {
 101         innerChannel.close();
 102     }
 103
 104     @Override
 105     protected void onExit(final int exitValue, final String exitMessage) {
 106         super.onExit(exitValue, exitMessage);
 107         innerChannel.close();
 108     }
 109
 110     private byte[] getHelloAdditionalMessageBytes() {
 111         final var session = getServerSession();
 112         final var address = (InetSocketAddress) session.getClientAddress();
 113         return new NetconfHelloMessageAdditionalHeader(session.getUsername(), address.getAddress().getHostAddress(),
 114             String.valueOf(address.getPort()), "ssh", "client")
 115             .toFormattedString().getBytes(StandardCharsets.UTF_8);
 116     }
 117 }