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 import android.net.IpPrefix; 21 22 import java.net.Inet4Address; 23 import java.net.Inet6Address; 24 import java.net.InetAddress; 25 import java.net.UnknownHostException; 26 27 /** 28 * Network constants used by the network stack. 29 * @hide 30 */ 31 public final class NetworkStackConstants { 32 33 /** 34 * Ethernet constants. 35 * 36 * See also: 37 * - https://tools.ietf.org/html/rfc894 38 * - https://tools.ietf.org/html/rfc2464 39 * - https://tools.ietf.org/html/rfc7042 40 * - http://www.iana.org/assignments/ethernet-numbers/ethernet-numbers.xhtml 41 * - http://www.iana.org/assignments/ieee-802-numbers/ieee-802-numbers.xhtml 42 */ 43 public static final int ETHER_DST_ADDR_OFFSET = 0; 44 public static final int ETHER_SRC_ADDR_OFFSET = 6; 45 public static final int ETHER_ADDR_LEN = 6; 46 public static final int ETHER_TYPE_OFFSET = 12; 47 public static final int ETHER_TYPE_LENGTH = 2; 48 public static final int ETHER_TYPE_ARP = 0x0806; 49 public static final int ETHER_TYPE_IPV4 = 0x0800; 50 public static final int ETHER_TYPE_IPV6 = 0x86dd; 51 public static final int ETHER_HEADER_LEN = 14; 52 public static final int ETHER_MTU = 1500; 53 public static final byte[] ETHER_BROADCAST = new byte[] { 54 (byte) 0xff, (byte) 0xff, (byte) 0xff, 55 (byte) 0xff, (byte) 0xff, (byte) 0xff, 56 }; 57 58 /** 59 * ARP constants. 60 * 61 * See also: 62 * - https://tools.ietf.org/html/rfc826 63 * - http://www.iana.org/assignments/arp-parameters/arp-parameters.xhtml 64 */ 65 public static final int ARP_PAYLOAD_LEN = 28; // For Ethernet+IPv4. 66 public static final int ARP_ETHER_IPV4_LEN = ARP_PAYLOAD_LEN + ETHER_HEADER_LEN; 67 public static final int ARP_REQUEST = 1; 68 public static final int ARP_REPLY = 2; 69 public static final int ARP_HWTYPE_RESERVED_LO = 0; 70 public static final int ARP_HWTYPE_ETHER = 1; 71 public static final int ARP_HWTYPE_RESERVED_HI = 0xffff; 72 73 /** 74 * IPv4 Address Conflict Detection constants. 75 * 76 * See also: 77 * - https://tools.ietf.org/html/rfc5227 78 */ 79 public static final int IPV4_CONFLICT_PROBE_NUM = 3; 80 public static final int IPV4_CONFLICT_ANNOUNCE_NUM = 2; 81 82 /** 83 * IPv4 constants. 84 * 85 * See also: 86 * - https://tools.ietf.org/html/rfc791 87 */ 88 public static final int IPV4_ADDR_BITS = 32; 89 public static final int IPV4_MIN_MTU = 68; 90 public static final int IPV4_MAX_MTU = 65_535; 91 public static final int IPV4_HEADER_MIN_LEN = 20; 92 public static final int IPV4_IHL_MASK = 0xf; 93 public static final int IPV4_LENGTH_OFFSET = 2; 94 public static final int IPV4_FLAGS_OFFSET = 6; 95 public static final int IPV4_FRAGMENT_MASK = 0x1fff; 96 public static final int IPV4_PROTOCOL_OFFSET = 9; 97 public static final int IPV4_CHECKSUM_OFFSET = 10; 98 public static final int IPV4_SRC_ADDR_OFFSET = 12; 99 public static final int IPV4_DST_ADDR_OFFSET = 16; 100 public static final int IPV4_ADDR_LEN = 4; 101 public static final int IPV4_FLAG_MF = 0x2000; 102 public static final int IPV4_FLAG_DF = 0x4000; 103 // getSockOpt() for v4 MTU 104 public static final int IP_MTU = 14; 105 public static final Inet4Address IPV4_ADDR_ALL = makeInet4Address( 106 (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff); 107 public static final Inet4Address IPV4_ADDR_ANY = makeInet4Address( 108 (byte) 0, (byte) 0, (byte) 0, (byte) 0); 109 public static final Inet6Address IPV6_ADDR_ANY = makeInet6Address(new byte[]{ 110 (byte) 0, (byte) 0, (byte) 0, (byte) 0, 111 (byte) 0, (byte) 0, (byte) 0, (byte) 0, 112 (byte) 0, (byte) 0, (byte) 0, (byte) 0, 113 (byte) 0, (byte) 0, (byte) 0, (byte) 0 }); 114 115 /** 116 * CLAT constants 117 */ 118 public static final IpPrefix CLAT_PREFIX = new IpPrefix("192.0.0.0/29"); 119 120 /** 121 * IPv6 constants. 122 * 123 * See also: 124 * - https://tools.ietf.org/html/rfc2460 125 */ 126 public static final int IPV6_ADDR_LEN = 16; 127 public static final int IPV6_HEADER_LEN = 40; 128 public static final int IPV6_LEN_OFFSET = 4; 129 public static final int IPV6_PROTOCOL_OFFSET = 6; 130 public static final int IPV6_SRC_ADDR_OFFSET = 8; 131 public static final int IPV6_DST_ADDR_OFFSET = 24; 132 public static final int IPV6_MIN_MTU = 1280; 133 public static final int IPV6_FRAGMENT_HEADER_LEN = 8; 134 public static final int RFC7421_PREFIX_LENGTH = 64; 135 // getSockOpt() for v6 MTU 136 public static final int IPV6_MTU = 24; 137 public static final Inet6Address IPV6_ADDR_ALL_NODES_MULTICAST = 138 (Inet6Address) InetAddresses.parseNumericAddress("ff02::1"); 139 public static final Inet6Address IPV6_ADDR_ALL_ROUTERS_MULTICAST = 140 (Inet6Address) InetAddresses.parseNumericAddress("ff02::2"); 141 public static final Inet6Address IPV6_ADDR_ALL_HOSTS_MULTICAST = 142 (Inet6Address) InetAddresses.parseNumericAddress("ff02::3"); 143 144 /** 145 * ICMP constants. 146 * 147 * See also: 148 * - https://tools.ietf.org/html/rfc792 149 */ 150 public static final int ICMP_CHECKSUM_OFFSET = 2; 151 public static final int ICMP_HEADER_LEN = 8; 152 /** 153 * ICMPv6 constants. 154 * 155 * See also: 156 * - https://tools.ietf.org/html/rfc4191 157 * - https://tools.ietf.org/html/rfc4443 158 * - https://tools.ietf.org/html/rfc4861 159 */ 160 public static final int ICMPV6_HEADER_MIN_LEN = 4; 161 public static final int ICMPV6_CHECKSUM_OFFSET = 2; 162 public static final int ICMPV6_ECHO_REPLY_TYPE = 129; 163 public static final int ICMPV6_ECHO_REQUEST_TYPE = 128; 164 public static final int ICMPV6_ROUTER_SOLICITATION = 133; 165 public static final int ICMPV6_ROUTER_ADVERTISEMENT = 134; 166 public static final int ICMPV6_NEIGHBOR_SOLICITATION = 135; 167 public static final int ICMPV6_NEIGHBOR_ADVERTISEMENT = 136; 168 public static final int ICMPV6_ND_OPTION_MIN_LENGTH = 8; 169 public static final int ICMPV6_ND_OPTION_LENGTH_SCALING_FACTOR = 8; 170 public static final int ICMPV6_ND_OPTION_SLLA = 1; 171 public static final int ICMPV6_ND_OPTION_TLLA = 2; 172 public static final int ICMPV6_ND_OPTION_PIO = 3; 173 public static final int ICMPV6_ND_OPTION_MTU = 5; 174 public static final int ICMPV6_ND_OPTION_RIO = 24; 175 public static final int ICMPV6_ND_OPTION_RDNSS = 25; 176 public static final int ICMPV6_ND_OPTION_PREF64 = 38; 177 178 public static final int ICMPV6_RS_HEADER_LEN = 8; 179 public static final int ICMPV6_RA_HEADER_LEN = 16; 180 public static final int ICMPV6_NS_HEADER_LEN = 24; 181 public static final int ICMPV6_NA_HEADER_LEN = 24; 182 public static final int ICMPV6_ND_OPTION_TLLA_LEN = 8; 183 public static final int ICMPV6_ND_OPTION_SLLA_LEN = 8; 184 185 public static final int NEIGHBOR_ADVERTISEMENT_FLAG_ROUTER = 1 << 31; 186 public static final int NEIGHBOR_ADVERTISEMENT_FLAG_SOLICITED = 1 << 30; 187 public static final int NEIGHBOR_ADVERTISEMENT_FLAG_OVERRIDE = 1 << 29; 188 189 public static final byte ROUTER_ADVERTISEMENT_FLAG_MANAGED_ADDRESS = (byte) (1 << 7); 190 public static final byte ROUTER_ADVERTISEMENT_FLAG_OTHER = (byte) (1 << 6); 191 192 public static final byte PIO_FLAG_ON_LINK = (byte) (1 << 7); 193 public static final byte PIO_FLAG_AUTONOMOUS = (byte) (1 << 6); 194 public static final byte PIO_FLAG_DHCPV6_PD_PREFERRED = (byte) (1 << 4); 195 196 /** 197 * TCP constants. 198 * 199 * See also: 200 * - https://tools.ietf.org/html/rfc793 201 */ 202 public static final int TCP_HEADER_MIN_LEN = 20; 203 public static final int TCP_CHECKSUM_OFFSET = 16; 204 public static final byte TCPHDR_FIN = (byte) (1 << 0); 205 public static final byte TCPHDR_SYN = (byte) (1 << 1); 206 public static final byte TCPHDR_RST = (byte) (1 << 2); 207 public static final byte TCPHDR_PSH = (byte) (1 << 3); 208 public static final byte TCPHDR_ACK = (byte) (1 << 4); 209 public static final byte TCPHDR_URG = (byte) (1 << 5); 210 211 /** 212 * UDP constants. 213 * 214 * See also: 215 * - https://tools.ietf.org/html/rfc768 216 */ 217 public static final int UDP_HEADER_LEN = 8; 218 public static final int UDP_SRCPORT_OFFSET = 0; 219 public static final int UDP_DSTPORT_OFFSET = 2; 220 public static final int UDP_LENGTH_OFFSET = 4; 221 public static final int UDP_CHECKSUM_OFFSET = 6; 222 223 /** 224 * DHCP constants. 225 * 226 * See also: 227 * - https://tools.ietf.org/html/rfc2131 228 */ 229 public static final int INFINITE_LEASE = 0xffffffff; 230 public static final int DHCP4_CLIENT_PORT = 68; 231 // The maximum length of a DHCP packet that can be constructed. 232 public static final int DHCP_MAX_LENGTH = 1500; 233 public static final int DHCP_MAX_OPTION_LEN = 255; 234 235 /** 236 * DHCPv6 constants. 237 * 238 * See also: 239 * - https://datatracker.ietf.org/doc/html/rfc8415 240 * - https://www.iana.org/assignments/dhcpv6-parameters/dhcpv6-parameters.xhtml 241 */ 242 public static final int DHCP6_CLIENT_PORT = 546; 243 public static final int DHCP6_SERVER_PORT = 547; 244 public static final Inet6Address ALL_DHCP_RELAY_AGENTS_AND_SERVERS = 245 (Inet6Address) InetAddresses.parseNumericAddress("ff02::1:2"); 246 public static final int DHCP6_OPTION_IA_ADDR = 5; 247 public static final int DHCP6_OPTION_IA_PD = 25; 248 public static final int DHCP6_OPTION_IAPREFIX = 26; 249 250 /** 251 * DNS constants. 252 * 253 * See also: 254 * - https://datatracker.ietf.org/doc/html/rfc7858#section-3.1 255 */ 256 public static final short DNS_OVER_TLS_PORT = 853; 257 258 /** 259 * IEEE802.11 standard constants. 260 * 261 * See also: 262 * - https://ieeexplore.ieee.org/document/7786995 263 */ 264 public static final int VENDOR_SPECIFIC_IE_ID = 0xdd; 265 266 267 /** 268 * TrafficStats constants. 269 */ 270 // These tags are used by the network stack to do traffic for its own purposes. Traffic 271 // tagged with these will be counted toward the network stack and must stay inside the 272 // range defined by 273 // {@link android.net.TrafficStats#TAG_NETWORK_STACK_RANGE_START} and 274 // {@link android.net.TrafficStats#TAG_NETWORK_STACK_RANGE_END}. 275 public static final int TAG_SYSTEM_DHCP = 0xFFFFFE01; 276 public static final int TAG_SYSTEM_NEIGHBOR = 0xFFFFFE02; 277 public static final int TAG_SYSTEM_DHCP_SERVER = 0xFFFFFE03; 278 279 // These tags are used by the network stack to do traffic on behalf of apps. Traffic 280 // tagged with these will be counted toward the app on behalf of which the network 281 // stack is doing this traffic. These values must stay inside the range defined by 282 // {@link android.net.TrafficStats#TAG_NETWORK_STACK_IMPERSONATION_RANGE_START} and 283 // {@link android.net.TrafficStats#TAG_NETWORK_STACK_IMPERSONATION_RANGE_END}. 284 public static final int TAG_SYSTEM_PROBE = 0xFFFFFF81; 285 public static final int TAG_SYSTEM_DNS = 0xFFFFFF82; 286 287 /** 288 * A test URL used to override configuration settings and overlays for the network validation 289 * HTTPS URL, when set in {@link android.provider.DeviceConfig} configuration. 290 * 291 * <p>This URL will be ignored if the host is not "localhost" (it can only be used to test with 292 * a local test server), and must not be set in production scenarios (as enforced by CTS tests). 293 * 294 * <p>{@link #TEST_URL_EXPIRATION_TIME} must also be set to use this setting. 295 */ 296 public static final String TEST_CAPTIVE_PORTAL_HTTPS_URL = "test_captive_portal_https_url"; 297 /** 298 * A test URL used to override configuration settings and overlays for the network validation 299 * HTTP URL, when set in {@link android.provider.DeviceConfig} configuration. 300 * 301 * <p>This URL will be ignored if the host is not "localhost" (it can only be used to test with 302 * a local test server), and must not be set in production scenarios (as enforced by CTS tests). 303 * 304 * <p>{@link #TEST_URL_EXPIRATION_TIME} must also be set to use this setting. 305 */ 306 public static final String TEST_CAPTIVE_PORTAL_HTTP_URL = "test_captive_portal_http_url"; 307 /** 308 * Expiration time of the test URL, in ms, relative to {@link System#currentTimeMillis()}. 309 * 310 * <p>After this expiration time, test URLs will be ignored. They will also be ignored if 311 * the expiration time is more than 10 minutes in the future, to avoid misconfiguration 312 * following test runs. 313 */ 314 public static final String TEST_URL_EXPIRATION_TIME = "test_url_expiration_time"; 315 316 // TODO: Move to Inet4AddressUtils 317 // See aosp/1455936: NetworkStackConstants can't depend on it as it causes jarjar-related issues 318 // for users of both the net-utils-device-common and net-utils-framework-common libraries. 319 // Jarjar rule management needs to be simplified for that: b/170445871 320 321 /** 322 * Make an Inet4Address from 4 bytes in network byte order. 323 */ makeInet4Address(byte b1, byte b2, byte b3, byte b4)324 private static Inet4Address makeInet4Address(byte b1, byte b2, byte b3, byte b4) { 325 try { 326 return (Inet4Address) InetAddress.getByAddress(new byte[] { b1, b2, b3, b4 }); 327 } catch (UnknownHostException e) { 328 throw new IllegalArgumentException("addr must be 4 bytes: this should never happen"); 329 } 330 } 331 332 /** 333 * Make an Inet6Address from 16 bytes in network byte order. 334 */ makeInet6Address(byte[] bytes)335 private static Inet6Address makeInet6Address(byte[] bytes) { 336 try { 337 return (Inet6Address) InetAddress.getByAddress(bytes); 338 } catch (UnknownHostException e) { 339 throw new IllegalArgumentException("addr must be 16 bytes: this should never happen"); 340 } 341 } NetworkStackConstants()342 private NetworkStackConstants() { 343 throw new UnsupportedOperationException("This class is not to be instantiated"); 344 } 345 } 346