Rahul Ravikumar | 0533600 | 2019-10-14 15:04:32 -0700 | [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.NetlinkConstants; |
| 20 | import android.system.OsConstants; |
| 21 | import java.nio.ByteBuffer; |
| 22 | |
| 23 | |
| 24 | /** |
| 25 | * struct ndmsg |
| 26 | * |
| 27 | * see: <linux_src>/include/uapi/linux/neighbour.h |
| 28 | * |
| 29 | * @hide |
| 30 | */ |
| 31 | public class StructNdMsg { |
| 32 | // Already aligned. |
| 33 | public static final int STRUCT_SIZE = 12; |
| 34 | |
| 35 | // Neighbor Cache Entry States |
| 36 | public static final short NUD_NONE = 0x00; |
| 37 | public static final short NUD_INCOMPLETE = 0x01; |
| 38 | public static final short NUD_REACHABLE = 0x02; |
| 39 | public static final short NUD_STALE = 0x04; |
| 40 | public static final short NUD_DELAY = 0x08; |
| 41 | public static final short NUD_PROBE = 0x10; |
| 42 | public static final short NUD_FAILED = 0x20; |
| 43 | public static final short NUD_NOARP = 0x40; |
| 44 | public static final short NUD_PERMANENT = 0x80; |
| 45 | |
| 46 | public static String stringForNudState(short nudState) { |
| 47 | switch (nudState) { |
| 48 | case NUD_NONE: return "NUD_NONE"; |
| 49 | case NUD_INCOMPLETE: return "NUD_INCOMPLETE"; |
| 50 | case NUD_REACHABLE: return "NUD_REACHABLE"; |
| 51 | case NUD_STALE: return "NUD_STALE"; |
| 52 | case NUD_DELAY: return "NUD_DELAY"; |
| 53 | case NUD_PROBE: return "NUD_PROBE"; |
| 54 | case NUD_FAILED: return "NUD_FAILED"; |
| 55 | case NUD_NOARP: return "NUD_NOARP"; |
| 56 | case NUD_PERMANENT: return "NUD_PERMANENT"; |
| 57 | default: |
| 58 | return "unknown NUD state: " + String.valueOf(nudState); |
| 59 | } |
| 60 | } |
| 61 | |
| 62 | public static boolean isNudStateConnected(short nudState) { |
| 63 | return ((nudState & (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE)) != 0); |
| 64 | } |
| 65 | |
| 66 | public static boolean isNudStateValid(short nudState) { |
| 67 | return (isNudStateConnected(nudState) || |
| 68 | ((nudState & (NUD_PROBE|NUD_STALE|NUD_DELAY)) != 0)); |
| 69 | } |
| 70 | |
| 71 | // Neighbor Cache Entry Flags |
| 72 | public static byte NTF_USE = (byte) 0x01; |
| 73 | public static byte NTF_SELF = (byte) 0x02; |
| 74 | public static byte NTF_MASTER = (byte) 0x04; |
| 75 | public static byte NTF_PROXY = (byte) 0x08; |
| 76 | public static byte NTF_ROUTER = (byte) 0x80; |
| 77 | |
| 78 | public static String stringForNudFlags(byte flags) { |
| 79 | final StringBuilder sb = new StringBuilder(); |
| 80 | if ((flags & NTF_USE) != 0) { |
| 81 | sb.append("NTF_USE"); |
| 82 | } |
| 83 | if ((flags & NTF_SELF) != 0) { |
| 84 | if (sb.length() > 0) { sb.append("|"); } |
| 85 | sb.append("NTF_SELF"); |
| 86 | } |
| 87 | if ((flags & NTF_MASTER) != 0) { |
| 88 | if (sb.length() > 0) { sb.append("|"); } |
| 89 | sb.append("NTF_MASTER"); |
| 90 | } |
| 91 | if ((flags & NTF_PROXY) != 0) { |
| 92 | if (sb.length() > 0) { sb.append("|"); |
| 93 | } |
| 94 | sb.append("NTF_PROXY"); } |
| 95 | if ((flags & NTF_ROUTER) != 0) { |
| 96 | if (sb.length() > 0) { sb.append("|"); } |
| 97 | sb.append("NTF_ROUTER"); |
| 98 | } |
| 99 | return sb.toString(); |
| 100 | } |
| 101 | |
| 102 | private static boolean hasAvailableSpace(ByteBuffer byteBuffer) { |
| 103 | return byteBuffer != null && byteBuffer.remaining() >= STRUCT_SIZE; |
| 104 | } |
| 105 | |
| 106 | public static StructNdMsg parse(ByteBuffer byteBuffer) { |
| 107 | if (!hasAvailableSpace(byteBuffer)) { return null; } |
| 108 | |
| 109 | // The ByteOrder must have already been set by the caller. In most |
| 110 | // cases ByteOrder.nativeOrder() is correct, with the possible |
| 111 | // exception of usage within unittests. |
| 112 | final StructNdMsg struct = new StructNdMsg(); |
| 113 | struct.ndm_family = byteBuffer.get(); |
| 114 | final byte pad1 = byteBuffer.get(); |
| 115 | final short pad2 = byteBuffer.getShort(); |
| 116 | struct.ndm_ifindex = byteBuffer.getInt(); |
| 117 | struct.ndm_state = byteBuffer.getShort(); |
| 118 | struct.ndm_flags = byteBuffer.get(); |
| 119 | struct.ndm_type = byteBuffer.get(); |
| 120 | return struct; |
| 121 | } |
| 122 | |
| 123 | public byte ndm_family; |
| 124 | public int ndm_ifindex; |
| 125 | public short ndm_state; |
| 126 | public byte ndm_flags; |
| 127 | public byte ndm_type; |
| 128 | |
| 129 | public StructNdMsg() { |
| 130 | ndm_family = (byte) OsConstants.AF_UNSPEC; |
| 131 | } |
| 132 | |
| 133 | public void pack(ByteBuffer byteBuffer) { |
| 134 | // The ByteOrder must have already been set by the caller. In most |
| 135 | // cases ByteOrder.nativeOrder() is correct, with the exception |
| 136 | // of usage within unittests. |
| 137 | byteBuffer.put(ndm_family); |
| 138 | byteBuffer.put((byte) 0); // pad1 |
| 139 | byteBuffer.putShort((short) 0); // pad2 |
| 140 | byteBuffer.putInt(ndm_ifindex); |
| 141 | byteBuffer.putShort(ndm_state); |
| 142 | byteBuffer.put(ndm_flags); |
| 143 | byteBuffer.put(ndm_type); |
| 144 | } |
| 145 | |
| 146 | public boolean nudConnected() { |
| 147 | return isNudStateConnected(ndm_state); |
| 148 | } |
| 149 | |
| 150 | public boolean nudValid() { |
| 151 | return isNudStateValid(ndm_state); |
| 152 | } |
| 153 | |
| 154 | @Override |
| 155 | public String toString() { |
| 156 | final String stateStr = "" + ndm_state + " (" + stringForNudState(ndm_state) + ")"; |
| 157 | final String flagsStr = "" + ndm_flags + " (" + stringForNudFlags(ndm_flags) + ")"; |
| 158 | return "StructNdMsg{ " |
| 159 | + "family{" + NetlinkConstants.stringForAddressFamily((int) ndm_family) + "}, " |
| 160 | + "ifindex{" + ndm_ifindex + "}, " |
| 161 | + "state{" + stateStr + "}, " |
| 162 | + "flags{" + flagsStr + "}, " |
| 163 | + "type{" + ndm_type + "} " |
| 164 | + "}"; |
| 165 | } |
| 166 | } |