Remi NGUYEN VAN | c1413d0 | 2018-06-06 15:47:07 +0900 | [diff] [blame] | 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 android.net.dhcp; |
| 18 | |
Remi NGUYEN VAN | b0762eb | 2018-08-28 11:06:54 +0900 | [diff] [blame] | 19 | import android.annotation.NonNull; |
Remi NGUYEN VAN | c1413d0 | 2018-06-06 15:47:07 +0900 | [diff] [blame] | 20 | import android.annotation.Nullable; |
| 21 | import android.net.util.FdEventsReader; |
Remi NGUYEN VAN | c1413d0 | 2018-06-06 15:47:07 +0900 | [diff] [blame] | 22 | import android.os.Handler; |
| 23 | import android.system.Os; |
| 24 | |
| 25 | import java.io.FileDescriptor; |
| 26 | import java.net.Inet4Address; |
Remi NGUYEN VAN | c1413d0 | 2018-06-06 15:47:07 +0900 | [diff] [blame] | 27 | import java.net.InetSocketAddress; |
| 28 | |
| 29 | /** |
| 30 | * A {@link FdEventsReader} to receive and parse {@link DhcpPacket}. |
| 31 | * @hide |
| 32 | */ |
| 33 | abstract class DhcpPacketListener extends FdEventsReader<DhcpPacketListener.Payload> { |
| 34 | static final class Payload { |
Remi NGUYEN VAN | 73105e11 | 2018-12-21 16:17:09 +0900 | [diff] [blame] | 35 | protected final byte[] mBytes = new byte[DhcpPacket.MAX_LENGTH]; |
| 36 | protected Inet4Address mSrcAddr; |
| 37 | protected int mSrcPort; |
Remi NGUYEN VAN | c1413d0 | 2018-06-06 15:47:07 +0900 | [diff] [blame] | 38 | } |
| 39 | |
Remi NGUYEN VAN | 73105e11 | 2018-12-21 16:17:09 +0900 | [diff] [blame] | 40 | DhcpPacketListener(@NonNull Handler handler) { |
Remi NGUYEN VAN | c1413d0 | 2018-06-06 15:47:07 +0900 | [diff] [blame] | 41 | super(handler, new Payload()); |
| 42 | } |
| 43 | |
| 44 | @Override |
Remi NGUYEN VAN | b0762eb | 2018-08-28 11:06:54 +0900 | [diff] [blame] | 45 | protected int recvBufSize(@NonNull Payload buffer) { |
Remi NGUYEN VAN | 73105e11 | 2018-12-21 16:17:09 +0900 | [diff] [blame] | 46 | return buffer.mBytes.length; |
Remi NGUYEN VAN | c1413d0 | 2018-06-06 15:47:07 +0900 | [diff] [blame] | 47 | } |
| 48 | |
| 49 | @Override |
Remi NGUYEN VAN | b0762eb | 2018-08-28 11:06:54 +0900 | [diff] [blame] | 50 | protected final void handlePacket(@NonNull Payload recvbuf, int length) { |
Remi NGUYEN VAN | 73105e11 | 2018-12-21 16:17:09 +0900 | [diff] [blame] | 51 | if (recvbuf.mSrcAddr == null) { |
Remi NGUYEN VAN | c1413d0 | 2018-06-06 15:47:07 +0900 | [diff] [blame] | 52 | return; |
| 53 | } |
| 54 | |
| 55 | try { |
Remi NGUYEN VAN | 73105e11 | 2018-12-21 16:17:09 +0900 | [diff] [blame] | 56 | final DhcpPacket packet = DhcpPacket.decodeFullPacket(recvbuf.mBytes, length, |
Remi NGUYEN VAN | c1413d0 | 2018-06-06 15:47:07 +0900 | [diff] [blame] | 57 | DhcpPacket.ENCAP_BOOTP); |
Remi NGUYEN VAN | 73105e11 | 2018-12-21 16:17:09 +0900 | [diff] [blame] | 58 | onReceive(packet, recvbuf.mSrcAddr, recvbuf.mSrcPort); |
Remi NGUYEN VAN | c1413d0 | 2018-06-06 15:47:07 +0900 | [diff] [blame] | 59 | } catch (DhcpPacket.ParseException e) { |
Remi NGUYEN VAN | 73105e11 | 2018-12-21 16:17:09 +0900 | [diff] [blame] | 60 | logParseError(recvbuf.mBytes, length, e); |
Remi NGUYEN VAN | c1413d0 | 2018-06-06 15:47:07 +0900 | [diff] [blame] | 61 | } |
| 62 | } |
| 63 | |
| 64 | @Override |
Remi NGUYEN VAN | b0762eb | 2018-08-28 11:06:54 +0900 | [diff] [blame] | 65 | protected int readPacket(@NonNull FileDescriptor fd, @NonNull Payload packetBuffer) |
| 66 | throws Exception { |
Remi NGUYEN VAN | c1413d0 | 2018-06-06 15:47:07 +0900 | [diff] [blame] | 67 | final InetSocketAddress addr = new InetSocketAddress(); |
| 68 | final int read = Os.recvfrom( |
Remi NGUYEN VAN | 73105e11 | 2018-12-21 16:17:09 +0900 | [diff] [blame] | 69 | fd, packetBuffer.mBytes, 0, packetBuffer.mBytes.length, 0 /* flags */, addr); |
Remi NGUYEN VAN | c1413d0 | 2018-06-06 15:47:07 +0900 | [diff] [blame] | 70 | |
| 71 | // Buffers with null srcAddr will be dropped in handlePacket() |
Remi NGUYEN VAN | 73105e11 | 2018-12-21 16:17:09 +0900 | [diff] [blame] | 72 | packetBuffer.mSrcAddr = inet4AddrOrNull(addr); |
| 73 | packetBuffer.mSrcPort = addr.getPort(); |
Remi NGUYEN VAN | c1413d0 | 2018-06-06 15:47:07 +0900 | [diff] [blame] | 74 | return read; |
| 75 | } |
| 76 | |
| 77 | @Nullable |
Remi NGUYEN VAN | b0762eb | 2018-08-28 11:06:54 +0900 | [diff] [blame] | 78 | private static Inet4Address inet4AddrOrNull(@NonNull InetSocketAddress addr) { |
Remi NGUYEN VAN | c1413d0 | 2018-06-06 15:47:07 +0900 | [diff] [blame] | 79 | return addr.getAddress() instanceof Inet4Address |
| 80 | ? (Inet4Address) addr.getAddress() |
| 81 | : null; |
| 82 | } |
| 83 | |
Remi NGUYEN VAN | b0762eb | 2018-08-28 11:06:54 +0900 | [diff] [blame] | 84 | protected abstract void onReceive(@NonNull DhcpPacket packet, @NonNull Inet4Address srcAddr, |
| 85 | int srcPort); |
| 86 | protected abstract void logParseError(@NonNull byte[] packet, int length, |
| 87 | @NonNull DhcpPacket.ParseException e); |
Remi NGUYEN VAN | c1413d0 | 2018-06-06 15:47:07 +0900 | [diff] [blame] | 88 | } |