From 06835112ab5b0714956468a6ae1bae4631a8adc9 Mon Sep 17 00:00:00 2001 From: junyulai Date: Thu, 3 Jan 2019 18:50:15 +0800 Subject: [KA02] internal cleanup and refactor for SocketKeepalive In previous change, the new SocketKeepalive API was exported. But internally, old PacketKeepalive names and structures are still used. This change rename them properly for code consistency and also refactor KeepalivePacketData to support different types of KeepalivePacketData. Bug: 114151147 Test: 1. atest FrameworksNetTests 2. atest FrameworksWifiTests 3. atest FrameworksTelephonyTests Change-Id: Ia9917d12987e91e87e34ffb3f126e7bc7c9c187e Merged-In: Ia9917d12987e91e87e34ffb3f126e7bc7c9c187e --- core/java/android/net/NattKeepalivePacketData.java | 77 ++++++++++++++++++++++ 1 file changed, 77 insertions(+) create mode 100644 core/java/android/net/NattKeepalivePacketData.java (limited to 'core/java/android/net/NattKeepalivePacketData.java') diff --git a/core/java/android/net/NattKeepalivePacketData.java b/core/java/android/net/NattKeepalivePacketData.java new file mode 100644 index 000000000000..dd2b108cdbfd --- /dev/null +++ b/core/java/android/net/NattKeepalivePacketData.java @@ -0,0 +1,77 @@ +/* + * Copyright (C) 2019 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; + +import android.net.SocketKeepalive.InvalidPacketException; +import android.net.util.IpUtils; +import android.system.OsConstants; + +import java.net.Inet4Address; +import java.net.InetAddress; +import java.nio.ByteBuffer; +import java.nio.ByteOrder; + +/** @hide */ +public final class NattKeepalivePacketData extends KeepalivePacketData { + + // This should only be constructed via static factory methods, such as + // nattKeepalivePacket + private NattKeepalivePacketData(InetAddress srcAddress, int srcPort, + InetAddress dstAddress, int dstPort, byte[] data) throws + InvalidPacketException { + super(srcAddress, srcPort, dstAddress, dstPort, data); + } + + /** + * Factory method to create Nat-T keepalive packet structure. + */ + public static NattKeepalivePacketData nattKeepalivePacket( + InetAddress srcAddress, int srcPort, InetAddress dstAddress, int dstPort) + throws InvalidPacketException { + + if (!(srcAddress instanceof Inet4Address) || !(dstAddress instanceof Inet4Address)) { + throw new InvalidPacketException(SocketKeepalive.ERROR_INVALID_IP_ADDRESS); + } + + if (dstPort != NattSocketKeepalive.NATT_PORT) { + throw new InvalidPacketException(SocketKeepalive.ERROR_INVALID_PORT); + } + + int length = IPV4_HEADER_LENGTH + UDP_HEADER_LENGTH + 1; + ByteBuffer buf = ByteBuffer.allocate(length); + buf.order(ByteOrder.BIG_ENDIAN); + buf.putShort((short) 0x4500); // IP version and TOS + buf.putShort((short) length); + buf.putInt(0); // ID, flags, offset + buf.put((byte) 64); // TTL + buf.put((byte) OsConstants.IPPROTO_UDP); + int ipChecksumOffset = buf.position(); + buf.putShort((short) 0); // IP checksum + buf.put(srcAddress.getAddress()); + buf.put(dstAddress.getAddress()); + buf.putShort((short) srcPort); + buf.putShort((short) dstPort); + buf.putShort((short) (length - 20)); // UDP length + int udpChecksumOffset = buf.position(); + buf.putShort((short) 0); // UDP checksum + buf.put((byte) 0xff); // NAT-T keepalive + buf.putShort(ipChecksumOffset, IpUtils.ipChecksum(buf, 0)); + buf.putShort(udpChecksumOffset, IpUtils.udpChecksum(buf, 0, IPV4_HEADER_LENGTH)); + + return new NattKeepalivePacketData(srcAddress, srcPort, dstAddress, dstPort, buf.array()); + } +} -- cgit v1.2.3