Jonathan Hart | 20d8e51 | 2014-10-16 11:05:52 -0700 | [diff] [blame] | 1 | package org.onlab.onos.sdnip.bgp; |
| 2 | |
| 3 | import java.util.concurrent.CountDownLatch; |
| 4 | |
| 5 | import org.jboss.netty.buffer.ChannelBuffer; |
| 6 | import org.jboss.netty.channel.Channel; |
| 7 | import org.jboss.netty.channel.ChannelHandlerContext; |
| 8 | import org.jboss.netty.handler.codec.frame.FrameDecoder; |
| 9 | import org.onlab.packet.IpAddress; |
| 10 | |
| 11 | /** |
| 12 | * Class for handling the decoding of the BGP messages at the remote |
| 13 | * BGP peer session. |
| 14 | */ |
| 15 | class TestBgpPeerFrameDecoder extends FrameDecoder { |
| 16 | int remoteBgpVersion; // 1 octet |
| 17 | long remoteAs; // 2 octets |
| 18 | long remoteHoldtime; // 2 octets |
| 19 | IpAddress remoteBgpIdentifier; // 4 octets -> IPv4 address |
| 20 | |
| 21 | final CountDownLatch receivedOpenMessageLatch = new CountDownLatch(1); |
| 22 | final CountDownLatch receivedKeepaliveMessageLatch = new CountDownLatch(1); |
| 23 | |
| 24 | @Override |
| 25 | protected Object decode(ChannelHandlerContext ctx, |
| 26 | Channel channel, |
| 27 | ChannelBuffer buf) throws Exception { |
| 28 | // Test for minimum length of the BGP message |
| 29 | if (buf.readableBytes() < BgpConstants.BGP_HEADER_LENGTH) { |
| 30 | // No enough data received |
| 31 | return null; |
| 32 | } |
| 33 | |
| 34 | // |
| 35 | // Mark the current buffer position in case we haven't received |
| 36 | // the whole message. |
| 37 | // |
| 38 | buf.markReaderIndex(); |
| 39 | |
| 40 | // |
| 41 | // Read and check the BGP message Marker field: it must be all ones |
| 42 | // |
| 43 | byte[] marker = new byte[BgpConstants.BGP_HEADER_MARKER_LENGTH]; |
| 44 | buf.readBytes(marker); |
| 45 | for (int i = 0; i < marker.length; i++) { |
| 46 | if (marker[i] != (byte) 0xff) { |
| 47 | // ERROR: Connection Not Synchronized. Close the channel. |
| 48 | ctx.getChannel().close(); |
| 49 | return null; |
| 50 | } |
| 51 | } |
| 52 | |
| 53 | // |
| 54 | // Read and check the BGP message Length field |
| 55 | // |
| 56 | int length = buf.readUnsignedShort(); |
| 57 | if ((length < BgpConstants.BGP_HEADER_LENGTH) || |
| 58 | (length > BgpConstants.BGP_MESSAGE_MAX_LENGTH)) { |
| 59 | // ERROR: Bad Message Length. Close the channel. |
| 60 | ctx.getChannel().close(); |
| 61 | return null; |
| 62 | } |
| 63 | |
| 64 | // |
| 65 | // Test whether the rest of the message is received: |
| 66 | // So far we have read the Marker (16 octets) and the |
| 67 | // Length (2 octets) fields. |
| 68 | // |
| 69 | int remainingMessageLen = |
| 70 | length - BgpConstants.BGP_HEADER_MARKER_LENGTH - 2; |
| 71 | if (buf.readableBytes() < remainingMessageLen) { |
| 72 | // No enough data received |
| 73 | buf.resetReaderIndex(); |
| 74 | return null; |
| 75 | } |
| 76 | |
| 77 | // |
| 78 | // Read the BGP message Type field, and process based on that type |
| 79 | // |
| 80 | int type = buf.readUnsignedByte(); |
| 81 | remainingMessageLen--; // Adjust after reading the type |
| 82 | ChannelBuffer message = buf.readBytes(remainingMessageLen); |
| 83 | |
| 84 | // |
| 85 | // Process the remaining of the message based on the message type |
| 86 | // |
| 87 | switch (type) { |
| 88 | case BgpConstants.BGP_TYPE_OPEN: |
| 89 | processBgpOpen(ctx, message); |
| 90 | break; |
| 91 | case BgpConstants.BGP_TYPE_UPDATE: |
| 92 | // NOTE: Not used as part of the test, because ONOS does not |
| 93 | // originate UPDATE messages. |
| 94 | break; |
| 95 | case BgpConstants.BGP_TYPE_NOTIFICATION: |
| 96 | // NOTE: Not used as part of the testing (yet) |
| 97 | break; |
| 98 | case BgpConstants.BGP_TYPE_KEEPALIVE: |
| 99 | processBgpKeepalive(ctx, message); |
| 100 | break; |
| 101 | default: |
| 102 | // ERROR: Bad Message Type. Close the channel. |
| 103 | ctx.getChannel().close(); |
| 104 | return null; |
| 105 | } |
| 106 | |
| 107 | return null; |
| 108 | } |
| 109 | |
| 110 | /** |
| 111 | * Processes BGP OPEN message. |
| 112 | * |
| 113 | * @param ctx the Channel Handler Context. |
| 114 | * @param message the message to process. |
| 115 | */ |
| 116 | private void processBgpOpen(ChannelHandlerContext ctx, |
| 117 | ChannelBuffer message) { |
| 118 | int minLength = |
| 119 | BgpConstants.BGP_OPEN_MIN_LENGTH - BgpConstants.BGP_HEADER_LENGTH; |
| 120 | if (message.readableBytes() < minLength) { |
| 121 | // ERROR: Bad Message Length. Close the channel. |
| 122 | ctx.getChannel().close(); |
| 123 | return; |
| 124 | } |
| 125 | |
| 126 | // |
| 127 | // Parse the OPEN message |
| 128 | // |
| 129 | remoteBgpVersion = message.readUnsignedByte(); |
| 130 | remoteAs = message.readUnsignedShort(); |
| 131 | remoteHoldtime = message.readUnsignedShort(); |
| 132 | remoteBgpIdentifier = IpAddress.valueOf((int) message.readUnsignedInt()); |
| 133 | // Optional Parameters |
| 134 | int optParamLen = message.readUnsignedByte(); |
| 135 | if (message.readableBytes() < optParamLen) { |
| 136 | // ERROR: Bad Message Length. Close the channel. |
| 137 | ctx.getChannel().close(); |
| 138 | return; |
| 139 | } |
| 140 | message.readBytes(optParamLen); // NOTE: data ignored |
| 141 | |
| 142 | // BGP OPEN message successfully received |
| 143 | receivedOpenMessageLatch.countDown(); |
| 144 | } |
| 145 | |
| 146 | /** |
| 147 | * Processes BGP KEEPALIVE message. |
| 148 | * |
| 149 | * @param ctx the Channel Handler Context. |
| 150 | * @param message the message to process. |
| 151 | */ |
| 152 | private void processBgpKeepalive(ChannelHandlerContext ctx, |
| 153 | ChannelBuffer message) { |
| 154 | if (message.readableBytes() + BgpConstants.BGP_HEADER_LENGTH != |
| 155 | BgpConstants.BGP_KEEPALIVE_EXPECTED_LENGTH) { |
| 156 | // ERROR: Bad Message Length. Close the channel. |
| 157 | ctx.getChannel().close(); |
| 158 | return; |
| 159 | } |
| 160 | // BGP KEEPALIVE message successfully received |
| 161 | receivedKeepaliveMessageLatch.countDown(); |
| 162 | } |
| 163 | } |