| /* |
| * Copyright (C) 2016 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.ip; |
| |
| import static android.net.util.SocketUtils.makePacketSocketAddress; |
| import static android.system.OsConstants.AF_PACKET; |
| import static android.system.OsConstants.ARPHRD_ETHER; |
| import static android.system.OsConstants.ETH_P_ALL; |
| import static android.system.OsConstants.SOCK_RAW; |
| |
| import android.net.NetworkUtils; |
| import android.net.util.ConnectivityPacketSummary; |
| import android.net.util.InterfaceParams; |
| import android.net.util.PacketReader; |
| import android.os.Handler; |
| import android.system.ErrnoException; |
| import android.system.Os; |
| import android.text.TextUtils; |
| import android.util.LocalLog; |
| import android.util.Log; |
| |
| import libcore.util.HexEncoding; |
| |
| import java.io.FileDescriptor; |
| import java.io.IOException; |
| |
| |
| /** |
| * Critical connectivity packet tracking daemon. |
| * |
| * Tracks ARP, DHCPv4, and IPv6 RS/RA/NS/NA packets. |
| * |
| * This class's constructor, start() and stop() methods must only be called |
| * from the same thread on which the passed in |log| is accessed. |
| * |
| * Log lines include a hexdump of the packet, which can be decoded via: |
| * |
| * echo -n H3XSTR1NG | sed -e 's/\([0-9A-F][0-9A-F]\)/\1 /g' -e 's/^/000000 /' |
| * | text2pcap - - |
| * | tcpdump -n -vv -e -r - |
| * |
| * @hide |
| */ |
| public class ConnectivityPacketTracker { |
| private static final String TAG = ConnectivityPacketTracker.class.getSimpleName(); |
| private static final boolean DBG = false; |
| private static final String MARK_START = "--- START ---"; |
| private static final String MARK_STOP = "--- STOP ---"; |
| private static final String MARK_NAMED_START = "--- START (%s) ---"; |
| private static final String MARK_NAMED_STOP = "--- STOP (%s) ---"; |
| |
| private final String mTag; |
| private final LocalLog mLog; |
| private final PacketReader mPacketListener; |
| private boolean mRunning; |
| private String mDisplayName; |
| |
| public ConnectivityPacketTracker(Handler h, InterfaceParams ifParams, LocalLog log) { |
| if (ifParams == null) throw new IllegalArgumentException("null InterfaceParams"); |
| |
| mTag = TAG + "." + ifParams.name; |
| mLog = log; |
| mPacketListener = new PacketListener(h, ifParams); |
| } |
| |
| public void start(String displayName) { |
| mRunning = true; |
| mDisplayName = displayName; |
| mPacketListener.start(); |
| } |
| |
| public void stop() { |
| mPacketListener.stop(); |
| mRunning = false; |
| mDisplayName = null; |
| } |
| |
| private final class PacketListener extends PacketReader { |
| private final InterfaceParams mInterface; |
| |
| PacketListener(Handler h, InterfaceParams ifParams) { |
| super(h, ifParams.defaultMtu); |
| mInterface = ifParams; |
| } |
| |
| @Override |
| protected FileDescriptor createFd() { |
| FileDescriptor s = null; |
| try { |
| s = Os.socket(AF_PACKET, SOCK_RAW, 0); |
| NetworkUtils.attachControlPacketFilter(s, ARPHRD_ETHER); |
| Os.bind(s, makePacketSocketAddress((short) ETH_P_ALL, mInterface.index)); |
| } catch (ErrnoException | IOException e) { |
| logError("Failed to create packet tracking socket: ", e); |
| closeFd(s); |
| return null; |
| } |
| return s; |
| } |
| |
| @Override |
| protected void handlePacket(byte[] recvbuf, int length) { |
| final String summary = ConnectivityPacketSummary.summarize( |
| mInterface.macAddr, recvbuf, length); |
| if (summary == null) return; |
| |
| if (DBG) Log.d(mTag, summary); |
| addLogEntry(summary + |
| "\n[" + new String(HexEncoding.encode(recvbuf, 0, length)) + "]"); |
| } |
| |
| @Override |
| protected void onStart() { |
| final String msg = TextUtils.isEmpty(mDisplayName) |
| ? MARK_START |
| : String.format(MARK_NAMED_START, mDisplayName); |
| mLog.log(msg); |
| } |
| |
| @Override |
| protected void onStop() { |
| String msg = TextUtils.isEmpty(mDisplayName) |
| ? MARK_STOP |
| : String.format(MARK_NAMED_STOP, mDisplayName); |
| if (!mRunning) msg += " (packet listener stopped unexpectedly)"; |
| mLog.log(msg); |
| } |
| |
| @Override |
| protected void logError(String msg, Exception e) { |
| Log.e(mTag, msg, e); |
| addLogEntry(msg + e); |
| } |
| |
| private void addLogEntry(String entry) { |
| mLog.log(entry); |
| } |
| } |
| } |