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 } 167
