/* * Copyright (C) 2024 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package android.net.apf; /** * The class which declares constants used in ApfFilter and unit tests. */ public final class ApfConstants { private ApfConstants() {} public static final int ETH_HEADER_LEN = 14; public static final int ETH_DEST_ADDR_OFFSET = 0; public static final int ETH_ETHERTYPE_OFFSET = 12; public static final int ETH_TYPE_MIN = 0x0600; public static final int ETH_TYPE_MAX = 0xFFFF; // TODO: Make these offsets relative to end of link-layer header; don't include ETH_HEADER_LEN. public static final int IPV4_TOTAL_LENGTH_OFFSET = ETH_HEADER_LEN + 2; public static final int IPV4_FRAGMENT_OFFSET_OFFSET = ETH_HEADER_LEN + 6; // Endianness is not an issue for this constant because the APF interpreter always operates in // network byte order. public static final int IPV4_FRAGMENT_OFFSET_MASK = 0x1fff; public static final int IPV4_FRAGMENT_MORE_FRAGS_MASK = 0x2000; public static final int IPV4_PROTOCOL_OFFSET = ETH_HEADER_LEN + 9; public static final int IPV4_SRC_ADDR_OFFSET = ETH_HEADER_LEN + 12; public static final int IPV4_DEST_ADDR_OFFSET = ETH_HEADER_LEN + 16; public static final int IPV4_ANY_HOST_ADDRESS = 0; public static final int IPV4_BROADCAST_ADDRESS = -1; // 255.255.255.255 // Traffic class and Flow label are not byte aligned. Luckily we // don't care about either value so we'll consider bytes 1-3 of the // IPv6 header as don't care. public static final int IPV6_FLOW_LABEL_OFFSET = ETH_HEADER_LEN + 1; public static final int IPV6_FLOW_LABEL_LEN = 3; public static final int IPV6_PAYLOAD_LEN_OFFSET = ETH_HEADER_LEN + 4; public static final int IPV6_NEXT_HEADER_OFFSET = ETH_HEADER_LEN + 6; public static final int IPV6_HOP_LIMIT_OFFSET = ETH_HEADER_LEN + 7; public static final int IPV6_SRC_ADDR_OFFSET = ETH_HEADER_LEN + 8; public static final int IPV6_DEST_ADDR_OFFSET = ETH_HEADER_LEN + 24; public static final int IPV6_HEADER_LEN = 40; // The IPv6 all nodes address ff02::1 public static final byte[] IPV6_ALL_NODES_ADDRESS = { (byte) 0xff, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 }; // The IPv6 unspecified address :: public static final byte[] IPV6_UNSPECIFIED_ADDRESS = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}; // The IPv6 solicited nodes multicast address prefix ff02::1:ffXX:X/104 public static final byte[] IPV6_SOLICITED_NODES_PREFIX = { (byte) 0xff, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, (byte) 0xff}; public static final int ICMP6_TYPE_OFFSET = ETH_HEADER_LEN + IPV6_HEADER_LEN; public static final int ICMP6_CODE_OFFSET = ETH_HEADER_LEN + IPV6_HEADER_LEN + 1; public static final int ICMP6_CHECKSUM_OFFSET = ETH_HEADER_LEN + IPV6_HEADER_LEN + 2; public static final int ICMP6_NS_TARGET_IP_OFFSET = ICMP6_TYPE_OFFSET + 8; public static final int ICMP6_NS_OPTION_TYPE_OFFSET = ICMP6_NS_TARGET_IP_OFFSET + 16; public static final int IPPROTO_HOPOPTS = 0; // NOTE: this must be added to the IPv4 header length in MemorySlot.IPV4_HEADER_SIZE public static final int TCP_UDP_SOURCE_PORT_OFFSET = ETH_HEADER_LEN; public static final int TCP_UDP_DESTINATION_PORT_OFFSET = ETH_HEADER_LEN + 2; public static final int UDP_HEADER_LEN = 8; public static final int TCP_HEADER_SIZE_OFFSET = 12; public static final int DHCP_SERVER_PORT = 67; public static final int DHCP_CLIENT_PORT = 68; public static final int ARP_HEADER_OFFSET = ETH_HEADER_LEN; public static final byte[] ARP_IPV4_HEADER = { 0, 1, // Hardware type: Ethernet (1) 8, 0, // Protocol type: IP (0x0800) 6, // Hardware size: 6 4, // Protocol size: 4 }; public static final int ARP_OPCODE_OFFSET = ARP_HEADER_OFFSET + 6; // Opcode: ARP request (0x0001), ARP reply (0x0002) public static final short ARP_OPCODE_REQUEST = 1; public static final short ARP_OPCODE_REPLY = 2; public static final int ARP_SOURCE_IP_ADDRESS_OFFSET = ARP_HEADER_OFFSET + 14; public static final int ARP_TARGET_IP_ADDRESS_OFFSET = ARP_HEADER_OFFSET + 24; // Limit on the Black List size to cap on program usage for this // TODO: Select a proper max length public static final int APF_MAX_ETH_TYPE_BLACK_LIST_LEN = 20; // The ethernet solicited nodes multicast address prefix 33:33:FF:xx:xx:xx public static final byte[] ETH_SOLICITED_NODES_PREFIX = {(byte) 0x33, (byte) 0x33, (byte) 0xff}; public static final byte[] ETH_MULTICAST_IPV6_ALL_NODES_MAC_ADDRESS = { (byte) 0x33, (byte) 0x33, 0, 0, 0, 1}; public static final byte[] ETH_MULTICAST_MDNS_V4_MAC_ADDRESS = {(byte) 0x01, (byte) 0x00, (byte) 0x5e, (byte) 0x00, (byte) 0x00, (byte) 0xfb}; public static final byte[] ETH_MULTICAST_MDNS_V6_MAC_ADDRESS = {(byte) 0x33, (byte) 0x33, (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0xfb}; public static final int MDNS_PORT = 5353; public static final int ECHO_PORT = 7; public static final int DNS_HEADER_LEN = 12; public static final int DNS_QDCOUNT_OFFSET = 4; // NOTE: this must be added to the IPv4 header length in MemorySlot.IPV4_HEADER_SIZE, or the // IPv6 header length. public static final int DHCP_CLIENT_MAC_OFFSET = ETH_HEADER_LEN + UDP_HEADER_LEN + 28; public static final int MDNS_QDCOUNT_OFFSET = ETH_HEADER_LEN + UDP_HEADER_LEN + DNS_QDCOUNT_OFFSET; public static final int MDNS_QNAME_OFFSET = ETH_HEADER_LEN + UDP_HEADER_LEN + DNS_HEADER_LEN; /** * Fixed byte sequence representing the following part of the ARP reply header: * EtherType + HTYPE + PTYPE + HLEN + PLEN + ops reply (0x0002) */ public static final byte[] FIXED_ARP_REPLY_HEADER = new byte[]{0x08, 0x06, 0x00, 0x01, 0x08, 0x00, 0x06, 0x04, 0x00, 0x02}; }