Erik Kline | 6193aa3 | 2015-01-20 12:28:26 +0900 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright (C) 2015 The Android Open Source Project |
| 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 android.net.netlink; |
| 18 | |
| 19 | import android.net.netlink.StructNdaCacheInfo; |
| 20 | import android.net.netlink.StructNdMsg; |
| 21 | import android.net.netlink.StructNlAttr; |
| 22 | import android.net.netlink.StructNlMsgHdr; |
| 23 | import android.net.netlink.NetlinkMessage; |
| 24 | import android.util.Log; |
| 25 | |
| 26 | import java.net.InetAddress; |
| 27 | import java.nio.ByteBuffer; |
| 28 | import java.nio.ByteOrder; |
| 29 | |
| 30 | |
| 31 | /** |
| 32 | * A NetlinkMessage subclass for netlink error messages. |
| 33 | * |
| 34 | * see also: <linux_src>/include/uapi/linux/neighbour.h |
| 35 | * |
| 36 | * @hide |
| 37 | */ |
| 38 | public class RtNetlinkNeighborMessage extends NetlinkMessage { |
| 39 | public static final short NDA_UNSPEC = 0; |
| 40 | public static final short NDA_DST = 1; |
| 41 | public static final short NDA_LLADDR = 2; |
| 42 | public static final short NDA_CACHEINFO = 3; |
| 43 | public static final short NDA_PROBES = 4; |
| 44 | public static final short NDA_VLAN = 5; |
| 45 | public static final short NDA_PORT = 6; |
| 46 | public static final short NDA_VNI = 7; |
| 47 | public static final short NDA_IFINDEX = 8; |
| 48 | public static final short NDA_MASTER = 9; |
| 49 | |
| 50 | private static StructNlAttr findNextAttrOfType(short attrType, ByteBuffer byteBuffer) { |
| 51 | while (byteBuffer != null && byteBuffer.remaining() > 0) { |
| 52 | final StructNlAttr nlAttr = StructNlAttr.peek(byteBuffer); |
| 53 | if (nlAttr == null) { |
| 54 | break; |
| 55 | } |
| 56 | if (nlAttr.nla_type == attrType) { |
| 57 | return StructNlAttr.parse(byteBuffer); |
| 58 | } |
| 59 | if (byteBuffer.remaining() < nlAttr.getAlignedLength()) { |
| 60 | break; |
| 61 | } |
| 62 | byteBuffer.position(byteBuffer.position() + nlAttr.getAlignedLength()); |
| 63 | } |
| 64 | return null; |
| 65 | } |
| 66 | |
| 67 | public static RtNetlinkNeighborMessage parse(StructNlMsgHdr header, ByteBuffer byteBuffer) { |
| 68 | final RtNetlinkNeighborMessage neighMsg = new RtNetlinkNeighborMessage(header); |
| 69 | |
| 70 | neighMsg.mNdmsg = StructNdMsg.parse(byteBuffer); |
| 71 | if (neighMsg.mNdmsg == null) { |
| 72 | return null; |
| 73 | } |
| 74 | |
| 75 | // Some of these are message-type dependent, and not always present. |
| 76 | final int baseOffset = byteBuffer.position(); |
| 77 | StructNlAttr nlAttr = findNextAttrOfType(NDA_DST, byteBuffer); |
| 78 | if (nlAttr != null) { |
| 79 | neighMsg.mDestination = nlAttr.getValueAsInetAddress(); |
| 80 | } |
| 81 | |
| 82 | byteBuffer.position(baseOffset); |
| 83 | nlAttr = findNextAttrOfType(NDA_LLADDR, byteBuffer); |
| 84 | if (nlAttr != null) { |
| 85 | neighMsg.mLinkLayerAddr = nlAttr.nla_value; |
| 86 | } |
| 87 | |
| 88 | byteBuffer.position(baseOffset); |
| 89 | nlAttr = findNextAttrOfType(NDA_PROBES, byteBuffer); |
| 90 | if (nlAttr != null) { |
| 91 | neighMsg.mNumProbes = nlAttr.getValueAsInt(0); |
| 92 | } |
| 93 | |
| 94 | byteBuffer.position(baseOffset); |
| 95 | nlAttr = findNextAttrOfType(NDA_CACHEINFO, byteBuffer); |
| 96 | if (nlAttr != null) { |
| 97 | neighMsg.mCacheInfo = StructNdaCacheInfo.parse(nlAttr.getValueAsByteBuffer()); |
| 98 | } |
| 99 | |
| 100 | final int kMinConsumed = StructNlMsgHdr.STRUCT_SIZE + StructNdMsg.STRUCT_SIZE; |
| 101 | final int kAdditionalSpace = NetlinkConstants.alignedLengthOf( |
| 102 | neighMsg.mHeader.nlmsg_len - kMinConsumed); |
| 103 | if (byteBuffer.remaining() < kAdditionalSpace) { |
| 104 | byteBuffer.position(byteBuffer.limit()); |
| 105 | } else { |
| 106 | byteBuffer.position(baseOffset + kAdditionalSpace); |
| 107 | } |
| 108 | |
| 109 | return neighMsg; |
| 110 | } |
| 111 | |
| 112 | /** |
| 113 | * A convenience method to create an RTM_GETNEIGH request message. |
| 114 | */ |
| 115 | public static byte[] newGetNeighborsRequest(int seqNo) { |
| 116 | final int length = StructNlMsgHdr.STRUCT_SIZE + StructNdMsg.STRUCT_SIZE; |
| 117 | final byte[] bytes = new byte[length]; |
| 118 | final ByteBuffer byteBuffer = ByteBuffer.wrap(bytes); |
| 119 | byteBuffer.order(ByteOrder.nativeOrder()); |
| 120 | |
| 121 | final StructNlMsgHdr nlmsghdr = new StructNlMsgHdr(); |
| 122 | nlmsghdr.nlmsg_len = length; |
| 123 | nlmsghdr.nlmsg_type = NetlinkConstants.RTM_GETNEIGH; |
| 124 | nlmsghdr.nlmsg_flags = StructNlMsgHdr.NLM_F_REQUEST|StructNlMsgHdr.NLM_F_DUMP; |
| 125 | nlmsghdr.nlmsg_seq = seqNo; |
| 126 | nlmsghdr.pack(byteBuffer); |
| 127 | |
| 128 | final StructNdMsg ndmsg = new StructNdMsg(); |
| 129 | ndmsg.pack(byteBuffer); |
| 130 | |
| 131 | return bytes; |
| 132 | } |
| 133 | |
| 134 | private StructNdMsg mNdmsg; |
| 135 | private InetAddress mDestination; |
| 136 | private byte[] mLinkLayerAddr; |
| 137 | private int mNumProbes; |
| 138 | private StructNdaCacheInfo mCacheInfo; |
| 139 | |
| 140 | private RtNetlinkNeighborMessage(StructNlMsgHdr header) { |
| 141 | super(header); |
| 142 | mNdmsg = null; |
| 143 | mDestination = null; |
| 144 | mLinkLayerAddr = null; |
| 145 | mNumProbes = 0; |
| 146 | mCacheInfo = null; |
| 147 | } |
| 148 | |
| 149 | public StructNdMsg getNdHeader() { |
| 150 | return mNdmsg; |
| 151 | } |
| 152 | |
| 153 | public InetAddress getDestination() { |
| 154 | return mDestination; |
| 155 | } |
| 156 | |
| 157 | public byte[] getLinkLayerAddress() { |
| 158 | return mLinkLayerAddr; |
| 159 | } |
| 160 | |
| 161 | public int getProbes() { |
| 162 | return mNumProbes; |
| 163 | } |
| 164 | |
| 165 | public StructNdaCacheInfo getCacheInfo() { |
| 166 | return mCacheInfo; |
| 167 | } |
| 168 | |
| 169 | @Override |
| 170 | public String toString() { |
| 171 | final String ipLiteral = (mDestination == null) ? "" : mDestination.getHostAddress(); |
| 172 | return "RtNetlinkNeighborMessage{ " |
| 173 | + "nlmsghdr{" + (mHeader == null ? "" : mHeader.toString()) + "}, " |
| 174 | + "ndmsg{" + (mNdmsg == null ? "" : mNdmsg.toString()) + "}, " |
| 175 | + "destination{" + ipLiteral + "} " |
| 176 | + "linklayeraddr{" + NetlinkConstants.hexify(mLinkLayerAddr) + "} " |
| 177 | + "probes{" + mNumProbes + "} " |
| 178 | + "cacheinfo{" + (mCacheInfo == null ? "" : mCacheInfo.toString()) + "} " |
| 179 | + "}"; |
| 180 | } |
| 181 | } |