1 /* 2 * Copyright (C) 2017 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 static android.net.netlink.NetlinkConstants.alignedLengthOf; 20 import static android.net.netlink.StructNlAttr.makeNestedType; 21 import static android.net.netlink.StructNlAttr.NLA_HEADERLEN; 22 import static android.net.netlink.StructNlMsgHdr.NLM_F_ACK; 23 import static android.net.netlink.StructNlMsgHdr.NLM_F_DUMP; 24 import static android.net.netlink.StructNlMsgHdr.NLM_F_REPLACE; 25 import static android.net.netlink.StructNlMsgHdr.NLM_F_REQUEST; 26 import static android.net.util.NetworkConstants.IPV4_ADDR_LEN; 27 import static java.nio.ByteOrder.BIG_ENDIAN; 28 29 import android.system.OsConstants; 30 import android.util.Log; 31 import libcore.io.SizeOf; 32 33 import java.net.Inet4Address; 34 import java.net.Inet6Address; 35 import java.net.InetAddress; 36 import java.nio.ByteBuffer; 37 import java.nio.ByteOrder; 38 39 40 /** 41 * A NetlinkMessage subclass for netlink conntrack messages. 42 * 43 * see also: <linux_src>/include/uapi/linux/netfilter/nfnetlink_conntrack.h 44 * 45 * @hide 46 */ 47 public class ConntrackMessage extends NetlinkMessage { 48 public static final int STRUCT_SIZE = StructNlMsgHdr.STRUCT_SIZE + StructNfGenMsg.STRUCT_SIZE; 49 50 public static final short NFNL_SUBSYS_CTNETLINK = 1; 51 public static final short IPCTNL_MSG_CT_NEW = 0; 52 53 // enum ctattr_type 54 public static final short CTA_TUPLE_ORIG = 1; 55 public static final short CTA_TUPLE_REPLY = 2; 56 public static final short CTA_TIMEOUT = 7; 57 58 // enum ctattr_tuple 59 public static final short CTA_TUPLE_IP = 1; 60 public static final short CTA_TUPLE_PROTO = 2; 61 62 // enum ctattr_ip 63 public static final short CTA_IP_V4_SRC = 1; 64 public static final short CTA_IP_V4_DST = 2; 65 66 // enum ctattr_l4proto 67 public static final short CTA_PROTO_NUM = 1; 68 public static final short CTA_PROTO_SRC_PORT = 2; 69 public static final short CTA_PROTO_DST_PORT = 3; 70 71 public static byte[] newIPv4TimeoutUpdateRequest( 72 int proto, Inet4Address src, int sport, Inet4Address dst, int dport, int timeoutSec) { 73 // *** STYLE WARNING *** 74 // 75 // Code below this point uses extra block indentation to highlight the 76 // packing of nested tuple netlink attribute types. 77 final StructNlAttr ctaTupleOrig = new StructNlAttr(CTA_TUPLE_ORIG, 78 new StructNlAttr(CTA_TUPLE_IP, 79 new StructNlAttr(CTA_IP_V4_SRC, src), 80 new StructNlAttr(CTA_IP_V4_DST, dst)), 81 new StructNlAttr(CTA_TUPLE_PROTO, 82 new StructNlAttr(CTA_PROTO_NUM, (byte) proto), 83 new StructNlAttr(CTA_PROTO_SRC_PORT, (short) sport, BIG_ENDIAN), 84 new StructNlAttr(CTA_PROTO_DST_PORT, (short) dport, BIG_ENDIAN))); 85 86 final StructNlAttr ctaTimeout = new StructNlAttr(CTA_TIMEOUT, timeoutSec, BIG_ENDIAN); 87 88 final int payloadLength = ctaTupleOrig.getAlignedLength() + ctaTimeout.getAlignedLength(); 89 final byte[] bytes = new byte[STRUCT_SIZE + payloadLength]; 90 final ByteBuffer byteBuffer = ByteBuffer.wrap(bytes); 91 byteBuffer.order(ByteOrder.nativeOrder()); 92 93 final ConntrackMessage ctmsg = new ConntrackMessage(); 94 ctmsg.mHeader.nlmsg_len = bytes.length; 95 ctmsg.mHeader.nlmsg_type = (NFNL_SUBSYS_CTNETLINK << 8) | IPCTNL_MSG_CT_NEW; 96 ctmsg.mHeader.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK | NLM_F_REPLACE; 97 ctmsg.mHeader.nlmsg_seq = 1; 98 ctmsg.pack(byteBuffer); 99 100 ctaTupleOrig.pack(byteBuffer); 101 ctaTimeout.pack(byteBuffer); 102 103 return bytes; 104 } 105 106 protected StructNfGenMsg mNfGenMsg; 107 108 private ConntrackMessage() { 109 super(new StructNlMsgHdr()); 110 mNfGenMsg = new StructNfGenMsg((byte) OsConstants.AF_INET); 111 } 112 113 public void pack(ByteBuffer byteBuffer) { 114 mHeader.pack(byteBuffer); 115 mNfGenMsg.pack(byteBuffer); 116 } 117 } 118