1 /* 2 * Copyright (C) 2018 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.server.util; 18 19 import static android.net.shared.Inet4AddressUtils.intToInet4AddressHTH; 20 21 import java.net.Inet4Address; 22 23 /** 24 * Network constants used by the network stack. 25 */ 26 public final class NetworkStackConstants { 27 28 /** 29 * IPv4 constants. 30 * 31 * See also: 32 * - https://tools.ietf.org/html/rfc791 33 */ 34 public static final int IPV4_ADDR_BITS = 32; 35 public static final int IPV4_MIN_MTU = 68; 36 public static final int IPV4_MAX_MTU = 65_535; 37 38 /** 39 * Ethernet constants. 40 * 41 * See also: 42 * - https://tools.ietf.org/html/rfc894 43 * - https://tools.ietf.org/html/rfc2464 44 * - https://tools.ietf.org/html/rfc7042 45 * - http://www.iana.org/assignments/ethernet-numbers/ethernet-numbers.xhtml 46 * - http://www.iana.org/assignments/ieee-802-numbers/ieee-802-numbers.xhtml 47 */ 48 public static final int ETHER_DST_ADDR_OFFSET = 0; 49 public static final int ETHER_SRC_ADDR_OFFSET = 6; 50 public static final int ETHER_ADDR_LEN = 6; 51 public static final int ETHER_TYPE_OFFSET = 12; 52 public static final int ETHER_TYPE_LENGTH = 2; 53 public static final int ETHER_TYPE_ARP = 0x0806; 54 public static final int ETHER_TYPE_IPV4 = 0x0800; 55 public static final int ETHER_TYPE_IPV6 = 0x86dd; 56 public static final int ETHER_HEADER_LEN = 14; 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_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 constants. 74 * 75 * See also: 76 * - https://tools.ietf.org/html/rfc791 77 */ 78 public static final int IPV4_HEADER_MIN_LEN = 20; 79 public static final int IPV4_IHL_MASK = 0xf; 80 public static final int IPV4_FLAGS_OFFSET = 6; 81 public static final int IPV4_FRAGMENT_MASK = 0x1fff; 82 public static final int IPV4_PROTOCOL_OFFSET = 9; 83 public static final int IPV4_SRC_ADDR_OFFSET = 12; 84 public static final int IPV4_DST_ADDR_OFFSET = 16; 85 public static final int IPV4_ADDR_LEN = 4; 86 public static final Inet4Address IPV4_ADDR_ALL = intToInet4AddressHTH(0xffffffff); 87 public static final Inet4Address IPV4_ADDR_ANY = intToInet4AddressHTH(0x0); 88 89 /** 90 * IPv6 constants. 91 * 92 * See also: 93 * - https://tools.ietf.org/html/rfc2460 94 */ 95 public static final int IPV6_ADDR_LEN = 16; 96 public static final int IPV6_HEADER_LEN = 40; 97 public static final int IPV6_PROTOCOL_OFFSET = 6; 98 public static final int IPV6_SRC_ADDR_OFFSET = 8; 99 public static final int IPV6_DST_ADDR_OFFSET = 24; 100 101 /** 102 * ICMPv6 constants. 103 * 104 * See also: 105 * - https://tools.ietf.org/html/rfc4443 106 * - https://tools.ietf.org/html/rfc4861 107 */ 108 public static final int ICMPV6_HEADER_MIN_LEN = 4; 109 public static final int ICMPV6_ECHO_REPLY_TYPE = 129; 110 public static final int ICMPV6_ECHO_REQUEST_TYPE = 128; 111 public static final int ICMPV6_ROUTER_SOLICITATION = 133; 112 public static final int ICMPV6_ROUTER_ADVERTISEMENT = 134; 113 public static final int ICMPV6_NEIGHBOR_SOLICITATION = 135; 114 public static final int ICMPV6_NEIGHBOR_ADVERTISEMENT = 136; 115 public static final int ICMPV6_ND_OPTION_MIN_LENGTH = 8; 116 public static final int ICMPV6_ND_OPTION_LENGTH_SCALING_FACTOR = 8; 117 public static final int ICMPV6_ND_OPTION_SLLA = 1; 118 public static final int ICMPV6_ND_OPTION_TLLA = 2; 119 public static final int ICMPV6_ND_OPTION_MTU = 5; 120 121 /** 122 * UDP constants. 123 * 124 * See also: 125 * - https://tools.ietf.org/html/rfc768 126 */ 127 public static final int UDP_HEADER_LEN = 8; 128 129 130 /** 131 * DHCP constants. 132 * 133 * See also: 134 * - https://tools.ietf.org/html/rfc2131 135 */ 136 public static final int INFINITE_LEASE = 0xffffffff; 137 public static final int DHCP4_CLIENT_PORT = 68; 138 NetworkStackConstants()139 private NetworkStackConstants() { 140 throw new UnsupportedOperationException("This class is not to be instantiated"); 141 } 142 } 143