Jonathan Hart | 3930f63 | 2015-10-19 12:12:51 -0700 | [diff] [blame] | 1 | /* |
Jonathan Hart | f4bd048 | 2017-01-27 15:11:18 -0800 | [diff] [blame] | 2 | * Copyright 2017-present Open Networking Laboratory |
Jonathan Hart | 3930f63 | 2015-10-19 12:12:51 -0700 | [diff] [blame] | 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | package org.onosproject.routing.fpm.protocol; |
| 18 | |
| 19 | import com.google.common.base.MoreObjects; |
| 20 | import org.onlab.packet.DeserializationException; |
| 21 | |
| 22 | import java.nio.ByteBuffer; |
| 23 | |
| 24 | import static org.onlab.packet.PacketUtils.checkInput; |
| 25 | |
| 26 | /** |
| 27 | * Netlink header. |
| 28 | * <p> |
| 29 | * Taken from struct nlmsghdr in linux/netlink.h |
| 30 | * </p> |
| 31 | */ |
| 32 | public final class Netlink { |
| 33 | |
| 34 | public static final int NETLINK_HEADER_LENGTH = 16; |
| 35 | |
| 36 | private final long length; |
| 37 | private final NetlinkMessageType type; |
| 38 | private final int flags; |
| 39 | private final long sequence; |
| 40 | private final long processPortId; |
| 41 | |
| 42 | private final RtNetlink rtNetlink; |
| 43 | |
| 44 | /** |
| 45 | * Class constructor. |
| 46 | * |
| 47 | * @param length message length |
| 48 | * @param type type |
| 49 | * @param flags flags |
| 50 | * @param sequence sequence number |
| 51 | * @param processPortId port ID |
| 52 | * @param rtNetlink netlink routing message |
| 53 | */ |
| 54 | private Netlink(long length, NetlinkMessageType type, int flags, long sequence, |
| 55 | long processPortId, RtNetlink rtNetlink) { |
| 56 | this.length = length; |
| 57 | this.type = type; |
| 58 | this.flags = flags; |
| 59 | this.sequence = sequence; |
| 60 | this.processPortId = processPortId; |
| 61 | this.rtNetlink = rtNetlink; |
| 62 | } |
| 63 | |
| 64 | /** |
| 65 | * Returns the message length. |
| 66 | * |
| 67 | * @return length |
| 68 | */ |
| 69 | public long length() { |
| 70 | return length; |
| 71 | } |
| 72 | |
| 73 | /** |
| 74 | * Returns the message type. |
| 75 | * |
| 76 | * @return message type |
| 77 | */ |
| 78 | public NetlinkMessageType type() { |
| 79 | return type; |
| 80 | } |
| 81 | |
| 82 | /** |
| 83 | * Returns the flags. |
| 84 | * |
| 85 | * @return flags |
| 86 | */ |
| 87 | public int flags() { |
| 88 | return flags; |
| 89 | } |
| 90 | |
| 91 | /** |
| 92 | * Returns the sequence number. |
| 93 | * |
| 94 | * @return sequence number |
| 95 | */ |
| 96 | public long sequence() { |
| 97 | return sequence; |
| 98 | } |
| 99 | |
| 100 | /** |
| 101 | * Returns the port ID. |
| 102 | * |
| 103 | * @return port ID |
| 104 | */ |
| 105 | public long processPortId() { |
| 106 | return processPortId; |
| 107 | } |
| 108 | |
| 109 | /** |
| 110 | * Returns the netlink routing message. |
| 111 | * |
| 112 | * @return netlink routing message |
| 113 | */ |
| 114 | public RtNetlink rtNetlink() { |
| 115 | return rtNetlink; |
| 116 | } |
| 117 | |
| 118 | @Override |
| 119 | public String toString() { |
| 120 | return MoreObjects.toStringHelper(getClass()) |
| 121 | .add("length", length) |
| 122 | .add("type", type) |
| 123 | .add("flags", flags) |
| 124 | .add("sequence", sequence) |
| 125 | .add("processPortId", processPortId) |
| 126 | .add("rtNetlink", rtNetlink) |
| 127 | .toString(); |
| 128 | } |
| 129 | |
| 130 | /** |
| 131 | * Decodes a netlink header from an input buffer. |
| 132 | * |
| 133 | * @param buffer input buffer |
| 134 | * @param start starting position the netlink header |
| 135 | * @param length length of the message |
| 136 | * @return netlink header |
| 137 | * @throws DeserializationException if a netlink header could not be |
| 138 | * decoded from the input buffer |
| 139 | */ |
| 140 | public static Netlink decode(byte[] buffer, int start, int length) throws |
| 141 | DeserializationException { |
| 142 | checkInput(buffer, start, length, NETLINK_HEADER_LENGTH); |
| 143 | |
| 144 | ByteBuffer bb = ByteBuffer.wrap(buffer, start, length); |
| 145 | |
| 146 | long messageLength = Integer.reverseBytes(bb.getInt()); |
| 147 | int type = Short.reverseBytes(bb.getShort()); |
| 148 | int flags = Short.reverseBytes(bb.getShort()); |
| 149 | long sequence = Integer.reverseBytes(bb.getInt()); |
| 150 | long processPortId = Integer.reverseBytes(bb.getInt()); |
| 151 | |
| 152 | NetlinkMessageType messageType = NetlinkMessageType.get(type); |
| 153 | if (messageType == null) { |
| 154 | throw new DeserializationException( |
| 155 | "Unsupported Netlink message type: " + type); |
| 156 | } |
| 157 | |
| 158 | // Netlink messages from Quagga's FPM protocol are always in the |
| 159 | // netlink route family (family 0). |
| 160 | RtNetlink rtNetlink = RtNetlink.decode(buffer, bb.position(), |
| 161 | bb.limit() - bb.position()); |
| 162 | |
| 163 | return new Netlink(messageLength, |
| 164 | messageType, |
| 165 | flags, |
| 166 | sequence, |
| 167 | processPortId, |
| 168 | rtNetlink); |
| 169 | } |
| 170 | |
| 171 | } |