tests/honeynode/2.2.1/netconf-netty-util/src/main/java/org/opendaylight/netconf/nettyutil/handler/NetconfXMLToHelloMessageDecoder.java

   1 /*
   2  * Copyright (c) 2014 Cisco Systems, Inc. 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.nettyutil.handler;
   9
  10 import com.google.common.annotations.VisibleForTesting;
  11 import com.google.common.base.Preconditions;
  12 import com.google.common.collect.ImmutableList;
  13 import com.google.common.collect.Lists;
  14 import io.netty.buffer.ByteBuf;
  15 import io.netty.buffer.ByteBufUtil;
  16 import io.netty.channel.ChannelHandlerContext;
  17 import io.netty.handler.codec.ByteToMessageDecoder;
  18 import java.io.ByteArrayInputStream;
  19 import java.io.IOException;
  20 import java.nio.ByteBuffer;
  21 import java.nio.charset.StandardCharsets;
  22 import java.util.Arrays;
  23 import java.util.List;
  24 import org.opendaylight.controller.config.util.xml.XmlUtil;
  25 import org.opendaylight.netconf.api.NetconfDocumentedException;
  26 import org.opendaylight.netconf.api.NetconfMessage;
  27 import org.opendaylight.netconf.api.messages.NetconfHelloMessage;
  28 import org.opendaylight.netconf.api.messages.NetconfHelloMessageAdditionalHeader;
  29 import org.slf4j.Logger;
  30 import org.slf4j.LoggerFactory;
  31 import org.w3c.dom.Document;
  32 import org.xml.sax.SAXException;
  33
  34 /**
  35  * Customized NetconfXMLToMessageDecoder that reads additional header with
  36  * session metadata from
  37  * {@link NetconfHelloMessage}*
  38  * This handler should be replaced in pipeline by regular message handler as last step of negotiation.
  39  * It serves as a message barrier and halts all non-hello netconf messages.
  40  * Netconf messages after hello should be processed once the negotiation succeeded.
  41  *
  42  */
  43 public final class NetconfXMLToHelloMessageDecoder extends ByteToMessageDecoder {
  44     private static final Logger LOG = LoggerFactory.getLogger(NetconfXMLToHelloMessageDecoder.class);
  45
  46     private static final List<byte[]> POSSIBLE_ENDS = ImmutableList.of(
  47             new byte[] { ']', '\n' },
  48             new byte[] { ']', '\r', '\n' });
  49     private static final List<byte[]> POSSIBLE_STARTS = ImmutableList.of(
  50             new byte[] { '[' },
  51             new byte[] { '\r', '\n', '[' },
  52             new byte[] { '\n', '[' });
  53
  54     // State variables do not have to by synchronized
  55     // Netty uses always the same (1) thread per pipeline
  56     // We use instance of this per pipeline
  57     private final List<NetconfMessage> nonHelloMessages = Lists.newArrayList();
  58     private boolean helloReceived = false;
  59
  60     @Override
  61     @VisibleForTesting
  62     public void decode(final ChannelHandlerContext ctx, final ByteBuf in, final List<Object> out)
  63             throws IOException, SAXException, NetconfDocumentedException {
  64         if (in.readableBytes() == 0) {
  65             LOG.debug("No more content in incoming buffer.");
  66             return;
  67         }
  68
  69         in.markReaderIndex();
  70         try {
  71             if (LOG.isTraceEnabled()) {
  72                 LOG.trace("Received to decode: {}", ByteBufUtil.hexDump(in));
  73             }
  74
  75             byte[] bytes = new byte[in.readableBytes()];
  76             in.readBytes(bytes);
  77
  78             logMessage(bytes);
  79
  80             // Extract bytes containing header with additional metadata
  81             String additionalHeader = null;
  82             if (startsWithAdditionalHeader(bytes)) {
  83                 // Auth information containing username, ip address... extracted for monitoring
  84                 int endOfAuthHeader = getAdditionalHeaderEndIndex(bytes);
  85                 if (endOfAuthHeader > -1) {
  86                     byte[] additionalHeaderBytes = Arrays.copyOfRange(bytes, 0, endOfAuthHeader);
  87                     additionalHeader = additionalHeaderToString(additionalHeaderBytes);
  88                     bytes = Arrays.copyOfRange(bytes, endOfAuthHeader, bytes.length);
  89                 }
  90             }
  91
  92             Document doc = XmlUtil.readXmlToDocument(new ByteArrayInputStream(bytes));
  93
  94             final NetconfMessage message = getNetconfMessage(additionalHeader, doc);
  95             if (message instanceof NetconfHelloMessage) {
  96                 Preconditions.checkState(helloReceived == false,
  97                         "Multiple hello messages received, unexpected hello: %s", message);
  98                 out.add(message);
  99                 helloReceived = true;
 100             // Non hello message, suspend the message and insert into cache
 101             } else {
 102                 Preconditions.checkState(helloReceived, "Hello message not received, instead received: %s", message);
 103                 LOG.debug("Netconf message received during negotiation, caching {}", message);
 104                 nonHelloMessages.add(message);
 105             }
 106         } finally {
 107             in.discardReadBytes();
 108         }
 109     }
 110
 111     private static NetconfMessage getNetconfMessage(final String additionalHeader, final Document doc)
 112             throws NetconfDocumentedException {
 113         NetconfMessage msg = new NetconfMessage(doc);
 114         if (NetconfHelloMessage.isHelloMessage(msg)) {
 115             if (additionalHeader != null) {
 116                 return new NetconfHelloMessage(doc, NetconfHelloMessageAdditionalHeader.fromString(additionalHeader));
 117             } else {
 118                 return new NetconfHelloMessage(doc);
 119             }
 120         }
 121
 122         return msg;
 123     }
 124
 125     private static int getAdditionalHeaderEndIndex(final byte[] bytes) {
 126         for (byte[] possibleEnd : POSSIBLE_ENDS) {
 127             int idx = findByteSequence(bytes, possibleEnd);
 128
 129             if (idx != -1) {
 130                 return idx + possibleEnd.length;
 131             }
 132         }
 133
 134         return -1;
 135     }
 136
 137     private static int findByteSequence(final byte[] bytes, final byte[] sequence) {
 138         if (bytes.length < sequence.length) {
 139             throw new IllegalArgumentException("Sequence to be found is longer than the given byte array.");
 140         }
 141         if (bytes.length == sequence.length) {
 142             if (Arrays.equals(bytes, sequence)) {
 143                 return 0;
 144             } else {
 145                 return -1;
 146             }
 147         }
 148         int index = 0;
 149         for (int i = 0; i < bytes.length; i++) {
 150             if (bytes[i] == sequence[index]) {
 151                 index++;
 152                 if (index == sequence.length) {
 153                     return i - index + 1;
 154                 }
 155             } else {
 156                 index = 0;
 157             }
 158         }
 159         return -1;
 160     }
 161
 162     private static void logMessage(final byte[] bytes) {
 163         if (LOG.isDebugEnabled()) {
 164             String string = StandardCharsets.UTF_8.decode(ByteBuffer.wrap(bytes)).toString();
 165             LOG.debug("Parsing message \n{}", string);
 166         }
 167     }
 168
 169     private static boolean startsWithAdditionalHeader(final byte[] bytes) {
 170         for (byte[] possibleStart : POSSIBLE_STARTS) {
 171             int index = 0;
 172             for (byte b : possibleStart) {
 173                 if (bytes[index++] != b) {
 174                     break;
 175                 }
 176
 177                 if (index == possibleStart.length) {
 178                     return true;
 179                 }
 180             }
 181         }
 182
 183         return false;
 184     }
 185
 186     private static String additionalHeaderToString(final byte[] bytes) {
 187         return StandardCharsets.UTF_8.decode(ByteBuffer.wrap(bytes)).toString();
 188     }
 189
 190     /**
 191      * Get netconf messages received during negotiation.
 192      *
 193      * @return Collection of NetconfMessages that were not hello, but were received during negotiation.
 194      */
 195     public Iterable<NetconfMessage> getPostHelloNetconfMessages() {
 196         return nonHelloMessages;
 197     }
 198 }