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