1 /* 2 * Copyright (C) 2020 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 com.android.net.module.util; 18 19 import android.net.InetAddresses; 20 21 import java.net.Inet4Address; 22 import java.net.Inet6Address; 23 import java.net.InetAddress; 24 import java.net.UnknownHostException; 25 26 /** 27 * Network constants used by the network stack. 28 * @hide 29 */ 30 public final class NetworkStackConstants { 31 32 /** 33 * Ethernet constants. 34 * 35 * See also: 36 * - https://tools.ietf.org/html/rfc894 37 * - https://tools.ietf.org/html/rfc2464 38 * - https://tools.ietf.org/html/rfc7042 39 * - http://www.iana.org/assignments/ethernet-numbers/ethernet-numbers.xhtml 40 * - http://www.iana.org/assignments/ieee-802-numbers/ieee-802-numbers.xhtml 41 */ 42 public static final int ETHER_DST_ADDR_OFFSET = 0; 43 public static final int ETHER_SRC_ADDR_OFFSET = 6; 44 public static final int ETHER_ADDR_LEN = 6; 45 public static final int ETHER_TYPE_OFFSET = 12; 46 public static final int ETHER_TYPE_LENGTH = 2; 47 public static final int ETHER_TYPE_ARP = 0x0806; 48 public static final int ETHER_TYPE_IPV4 = 0x0800; 49 public static final int ETHER_TYPE_IPV6 = 0x86dd; 50 public static final int ETHER_HEADER_LEN = 14; 51 public static final int ETHER_MTU = 1500; 52 public static final byte[] ETHER_BROADCAST = new byte[] { 53 (byte) 0xff, (byte) 0xff, (byte) 0xff, 54 (byte) 0xff, (byte) 0xff, (byte) 0xff, 55 }; 56 57 /** 58 * ARP constants. 59 * 60 * See also: 61 * - https://tools.ietf.org/html/rfc826 62 * - http://www.iana.org/assignments/arp-parameters/arp-parameters.xhtml 63 */ 64 public static final int ARP_PAYLOAD_LEN = 28; // For Ethernet+IPv4. 65 public static final int ARP_ETHER_IPV4_LEN = ARP_PAYLOAD_LEN + ETHER_HEADER_LEN; 66 public static final int ARP_REQUEST = 1; 67 public static final int ARP_REPLY = 2; 68 public static final int ARP_HWTYPE_RESERVED_LO = 0; 69 public static final int ARP_HWTYPE_ETHER = 1; 70 public static final int ARP_HWTYPE_RESERVED_HI = 0xffff; 71 72 /** 73 * IPv4 Address Conflict Detection constants. 74 * 75 * See also: 76 * - https://tools.ietf.org/html/rfc5227 77 */ 78 public static final int IPV4_CONFLICT_PROBE_NUM = 3; 79 public static final int IPV4_CONFLICT_ANNOUNCE_NUM = 2; 80 81 /** 82 * IPv4 constants. 83 * 84 * See also: 85 * - https://tools.ietf.org/html/rfc791 86 */ 87 public static final int IPV4_ADDR_BITS = 32; 88 public static final int IPV4_MIN_MTU = 68; 89 public static final int IPV4_MAX_MTU = 65_535; 90 public static final int IPV4_HEADER_MIN_LEN = 20; 91 public static final int IPV4_IHL_MASK = 0xf; 92 public static final int IPV4_FLAGS_OFFSET = 6; 93 public static final int IPV4_FRAGMENT_MASK = 0x1fff; 94 public static final int IPV4_PROTOCOL_OFFSET = 9; 95 public static final int IPV4_SRC_ADDR_OFFSET = 12; 96 public static final int IPV4_DST_ADDR_OFFSET = 16; 97 public static final int IPV4_ADDR_LEN = 4; 98 public static final Inet4Address IPV4_ADDR_ALL = makeInet4Address( 99 (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff); 100 public static final Inet4Address IPV4_ADDR_ANY = makeInet4Address( 101 (byte) 0, (byte) 0, (byte) 0, (byte) 0); 102 public static final Inet6Address IPV6_ADDR_ANY = makeInet6Address(new byte[]{ 103 (byte) 0, (byte) 0, (byte) 0, (byte) 0, 104 (byte) 0, (byte) 0, (byte) 0, (byte) 0, 105 (byte) 0, (byte) 0, (byte) 0, (byte) 0, 106 (byte) 0, (byte) 0, (byte) 0, (byte) 0 }); 107 /** 108 * IPv6 constants. 109 * 110 * See also: 111 * - https://tools.ietf.org/html/rfc2460 112 */ 113 public static final int IPV6_ADDR_LEN = 16; 114 public static final int IPV6_HEADER_LEN = 40; 115 public static final int IPV6_LEN_OFFSET = 4; 116 public static final int IPV6_PROTOCOL_OFFSET = 6; 117 public static final int IPV6_SRC_ADDR_OFFSET = 8; 118 public static final int IPV6_DST_ADDR_OFFSET = 24; 119 public static final int IPV6_MIN_MTU = 1280; 120 public static final Inet6Address IPV6_ADDR_ALL_NODES_MULTICAST = 121 (Inet6Address) InetAddresses.parseNumericAddress("ff02::1"); 122 public static final Inet6Address IPV6_ADDR_ALL_ROUTERS_MULTICAST = 123 (Inet6Address) InetAddresses.parseNumericAddress("ff02::2"); 124 public static final Inet6Address IPV6_ADDR_ALL_HOSTS_MULTICAST = 125 (Inet6Address) InetAddresses.parseNumericAddress("ff02::3"); 126 127 /** 128 * ICMPv6 constants. 129 * 130 * See also: 131 * - https://tools.ietf.org/html/rfc4443 132 * - https://tools.ietf.org/html/rfc4861 133 */ 134 public static final int ICMPV6_HEADER_MIN_LEN = 4; 135 public static final int ICMPV6_CHECKSUM_OFFSET = 2; 136 public static final int ICMPV6_ECHO_REPLY_TYPE = 129; 137 public static final int ICMPV6_ECHO_REQUEST_TYPE = 128; 138 public static final int ICMPV6_ROUTER_SOLICITATION = 133; 139 public static final int ICMPV6_ROUTER_ADVERTISEMENT = 134; 140 public static final int ICMPV6_NEIGHBOR_SOLICITATION = 135; 141 public static final int ICMPV6_NEIGHBOR_ADVERTISEMENT = 136; 142 public static final int ICMPV6_ND_OPTION_MIN_LENGTH = 8; 143 public static final int ICMPV6_ND_OPTION_LENGTH_SCALING_FACTOR = 8; 144 public static final int ICMPV6_ND_OPTION_SLLA = 1; 145 public static final int ICMPV6_ND_OPTION_TLLA = 2; 146 public static final int ICMPV6_ND_OPTION_PIO = 3; 147 public static final int ICMPV6_ND_OPTION_MTU = 5; 148 public static final int ICMPV6_ND_OPTION_RDNSS = 25; 149 public static final int ICMPV6_ND_OPTION_PREF64 = 38; 150 151 public static final int ICMPV6_RA_HEADER_LEN = 16; 152 153 public static final int NEIGHBOR_ADVERTISEMENT_FLAG_ROUTER = 1 << 31; 154 public static final int NEIGHBOR_ADVERTISEMENT_FLAG_SOLICITED = 1 << 30; 155 public static final int NEIGHBOR_ADVERTISEMENT_FLAG_OVERRIDE = 1 << 29; 156 157 public static final byte ROUTER_ADVERTISEMENT_FLAG_MANAGED_ADDRESS = (byte) (1 << 7); 158 public static final byte ROUTER_ADVERTISEMENT_FLAG_OTHER = (byte) (1 << 6); 159 160 public static final byte PIO_FLAG_ON_LINK = (byte) (1 << 7); 161 public static final byte PIO_FLAG_AUTONOMOUS = (byte) (1 << 6); 162 163 /** 164 * UDP constants. 165 * 166 * See also: 167 * - https://tools.ietf.org/html/rfc768 168 */ 169 public static final int UDP_HEADER_LEN = 8; 170 171 172 /** 173 * DHCP constants. 174 * 175 * See also: 176 * - https://tools.ietf.org/html/rfc2131 177 */ 178 public static final int INFINITE_LEASE = 0xffffffff; 179 public static final int DHCP4_CLIENT_PORT = 68; 180 181 /** 182 * IEEE802.11 standard constants. 183 * 184 * See also: 185 * - https://ieeexplore.ieee.org/document/7786995 186 */ 187 public static final int VENDOR_SPECIFIC_IE_ID = 0xdd; 188 189 190 /** 191 * TrafficStats constants. 192 */ 193 // These tags are used by the network stack to do traffic for its own purposes. Traffic 194 // tagged with these will be counted toward the network stack and must stay inside the 195 // range defined by 196 // {@link android.net.TrafficStats#TAG_NETWORK_STACK_RANGE_START} and 197 // {@link android.net.TrafficStats#TAG_NETWORK_STACK_RANGE_END}. 198 public static final int TAG_SYSTEM_DHCP = 0xFFFFFE01; 199 public static final int TAG_SYSTEM_NEIGHBOR = 0xFFFFFE02; 200 public static final int TAG_SYSTEM_DHCP_SERVER = 0xFFFFFE03; 201 202 // These tags are used by the network stack to do traffic on behalf of apps. Traffic 203 // tagged with these will be counted toward the app on behalf of which the network 204 // stack is doing this traffic. These values must stay inside the range defined by 205 // {@link android.net.TrafficStats#TAG_NETWORK_STACK_IMPERSONATION_RANGE_START} and 206 // {@link android.net.TrafficStats#TAG_NETWORK_STACK_IMPERSONATION_RANGE_END}. 207 public static final int TAG_SYSTEM_PROBE = 0xFFFFFF81; 208 public static final int TAG_SYSTEM_DNS = 0xFFFFFF82; 209 210 // TODO: Move to Inet4AddressUtils 211 // See aosp/1455936: NetworkStackConstants can't depend on it as it causes jarjar-related issues 212 // for users of both the net-utils-device-common and net-utils-framework-common libraries. 213 // Jarjar rule management needs to be simplified for that: b/170445871 214 215 /** 216 * Make an Inet4Address from 4 bytes in network byte order. 217 */ makeInet4Address(byte b1, byte b2, byte b3, byte b4)218 private static Inet4Address makeInet4Address(byte b1, byte b2, byte b3, byte b4) { 219 try { 220 return (Inet4Address) InetAddress.getByAddress(new byte[] { b1, b2, b3, b4 }); 221 } catch (UnknownHostException e) { 222 throw new IllegalArgumentException("addr must be 4 bytes: this should never happen"); 223 } 224 } 225 226 /** 227 * Make an Inet6Address from 16 bytes in network byte order. 228 */ makeInet6Address(byte[] bytes)229 private static Inet6Address makeInet6Address(byte[] bytes) { 230 try { 231 return (Inet6Address) InetAddress.getByAddress(bytes); 232 } catch (UnknownHostException e) { 233 throw new IllegalArgumentException("addr must be 16 bytes: this should never happen"); 234 } 235 } NetworkStackConstants()236 private NetworkStackConstants() { 237 throw new UnsupportedOperationException("This class is not to be instantiated"); 238 } 239 } 240