| /* |
| * Copyright (C) 2015 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 com.android.server.connectivity; |
| |
| import static android.net.NattSocketKeepalive.NATT_PORT; |
| import static android.net.NetworkAgent.CMD_ADD_KEEPALIVE_PACKET_FILTER; |
| import static android.net.NetworkAgent.CMD_REMOVE_KEEPALIVE_PACKET_FILTER; |
| import static android.net.NetworkAgent.CMD_START_SOCKET_KEEPALIVE; |
| import static android.net.NetworkAgent.CMD_STOP_SOCKET_KEEPALIVE; |
| import static android.net.SocketKeepalive.BINDER_DIED; |
| import static android.net.SocketKeepalive.DATA_RECEIVED; |
| import static android.net.SocketKeepalive.ERROR_INVALID_INTERVAL; |
| import static android.net.SocketKeepalive.ERROR_INVALID_IP_ADDRESS; |
| import static android.net.SocketKeepalive.ERROR_INVALID_NETWORK; |
| import static android.net.SocketKeepalive.ERROR_INVALID_SOCKET; |
| import static android.net.SocketKeepalive.MAX_INTERVAL_SEC; |
| import static android.net.SocketKeepalive.MIN_INTERVAL_SEC; |
| import static android.net.SocketKeepalive.NO_KEEPALIVE; |
| import static android.net.SocketKeepalive.SUCCESS; |
| |
| import android.annotation.NonNull; |
| import android.annotation.Nullable; |
| import android.net.ISocketKeepaliveCallback; |
| import android.net.KeepalivePacketData; |
| import android.net.NattKeepalivePacketData; |
| import android.net.NetworkAgent; |
| import android.net.NetworkUtils; |
| import android.net.SocketKeepalive.InvalidPacketException; |
| import android.net.SocketKeepalive.InvalidSocketException; |
| import android.net.TcpKeepalivePacketData; |
| import android.net.TcpKeepalivePacketData.TcpSocketInfo; |
| import android.net.util.IpUtils; |
| import android.os.Binder; |
| import android.os.Handler; |
| import android.os.IBinder; |
| import android.os.Message; |
| import android.os.Process; |
| import android.os.RemoteException; |
| import android.system.ErrnoException; |
| import android.system.Os; |
| import android.util.Log; |
| import android.util.Pair; |
| |
| import com.android.internal.util.HexDump; |
| import com.android.internal.util.IndentingPrintWriter; |
| |
| import java.io.FileDescriptor; |
| import java.net.InetAddress; |
| import java.net.InetSocketAddress; |
| import java.net.SocketAddress; |
| import java.util.ArrayList; |
| import java.util.HashMap; |
| |
| /** |
| * Manages socket keepalive requests. |
| * |
| * Provides methods to stop and start keepalive requests, and keeps track of keepalives across all |
| * networks. This class is tightly coupled to ConnectivityService. It is not thread-safe and its |
| * handle* methods must be called only from the ConnectivityService handler thread. |
| */ |
| public class KeepaliveTracker { |
| |
| private static final String TAG = "KeepaliveTracker"; |
| private static final boolean DBG = false; |
| |
| public static final String PERMISSION = android.Manifest.permission.PACKET_KEEPALIVE_OFFLOAD; |
| |
| /** Keeps track of keepalive requests. */ |
| private final HashMap <NetworkAgentInfo, HashMap<Integer, KeepaliveInfo>> mKeepalives = |
| new HashMap<> (); |
| private final Handler mConnectivityServiceHandler; |
| @NonNull |
| private final TcpKeepaliveController mTcpController; |
| |
| public KeepaliveTracker(Handler handler) { |
| mConnectivityServiceHandler = handler; |
| mTcpController = new TcpKeepaliveController(handler); |
| } |
| |
| /** |
| * Tracks information about a socket keepalive. |
| * |
| * All information about this keepalive is known at construction time except the slot number, |
| * which is only returned when the hardware has successfully started the keepalive. |
| */ |
| class KeepaliveInfo implements IBinder.DeathRecipient { |
| // Bookkeeping data. |
| private final ISocketKeepaliveCallback mCallback; |
| private final int mUid; |
| private final int mPid; |
| private final NetworkAgentInfo mNai; |
| private final int mType; |
| private final FileDescriptor mFd; |
| |
| public static final int TYPE_NATT = 1; |
| public static final int TYPE_TCP = 2; |
| |
| // Keepalive slot. A small integer that identifies this keepalive among the ones handled |
| // by this network. |
| private int mSlot = NO_KEEPALIVE; |
| |
| // Packet data. |
| private final KeepalivePacketData mPacket; |
| private final int mInterval; |
| |
| // Whether the keepalive is started or not. The initial state is NOT_STARTED. |
| private static final int NOT_STARTED = 1; |
| private static final int STARTING = 2; |
| private static final int STARTED = 3; |
| private int mStartedState = NOT_STARTED; |
| |
| KeepaliveInfo(@NonNull ISocketKeepaliveCallback callback, |
| @NonNull NetworkAgentInfo nai, |
| @NonNull KeepalivePacketData packet, |
| int interval, |
| int type, |
| @NonNull FileDescriptor fd) { |
| mCallback = callback; |
| mPid = Binder.getCallingPid(); |
| mUid = Binder.getCallingUid(); |
| |
| mNai = nai; |
| mPacket = packet; |
| mInterval = interval; |
| mType = type; |
| mFd = fd; |
| |
| try { |
| mCallback.asBinder().linkToDeath(this, 0); |
| } catch (RemoteException e) { |
| binderDied(); |
| } |
| } |
| |
| public NetworkAgentInfo getNai() { |
| return mNai; |
| } |
| |
| private String startedStateString(final int state) { |
| switch (state) { |
| case NOT_STARTED : return "NOT_STARTED"; |
| case STARTING : return "STARTING"; |
| case STARTED : return "STARTED"; |
| } |
| throw new IllegalArgumentException("Unknown state"); |
| } |
| |
| public String toString() { |
| return "KeepaliveInfo [" |
| + " network=" + mNai.network |
| + " startedState=" + startedStateString(mStartedState) |
| + " " |
| + IpUtils.addressAndPortToString(mPacket.srcAddress, mPacket.srcPort) |
| + "->" |
| + IpUtils.addressAndPortToString(mPacket.dstAddress, mPacket.dstPort) |
| + " interval=" + mInterval |
| + " uid=" + mUid + " pid=" + mPid |
| + " packetData=" + HexDump.toHexString(mPacket.getPacket()) |
| + " ]"; |
| } |
| |
| /** Called when the application process is killed. */ |
| public void binderDied() { |
| stop(BINDER_DIED); |
| } |
| |
| void unlinkDeathRecipient() { |
| if (mCallback != null) { |
| mCallback.asBinder().unlinkToDeath(this, 0); |
| } |
| } |
| |
| private int checkNetworkConnected() { |
| if (!mNai.networkInfo.isConnectedOrConnecting()) { |
| return ERROR_INVALID_NETWORK; |
| } |
| return SUCCESS; |
| } |
| |
| private int checkSourceAddress() { |
| // Check that we have the source address. |
| for (InetAddress address : mNai.linkProperties.getAddresses()) { |
| if (address.equals(mPacket.srcAddress)) { |
| return SUCCESS; |
| } |
| } |
| return ERROR_INVALID_IP_ADDRESS; |
| } |
| |
| private int checkInterval() { |
| if (mInterval < MIN_INTERVAL_SEC || mInterval > MAX_INTERVAL_SEC) { |
| return ERROR_INVALID_INTERVAL; |
| } |
| return SUCCESS; |
| } |
| |
| private int isValid() { |
| synchronized (mNai) { |
| int error = checkInterval(); |
| if (error == SUCCESS) error = checkNetworkConnected(); |
| if (error == SUCCESS) error = checkSourceAddress(); |
| return error; |
| } |
| } |
| |
| void start(int slot) { |
| mSlot = slot; |
| int error = isValid(); |
| if (error == SUCCESS) { |
| Log.d(TAG, "Starting keepalive " + mSlot + " on " + mNai.name()); |
| switch (mType) { |
| case TYPE_NATT: |
| mNai.asyncChannel |
| .sendMessage(CMD_START_SOCKET_KEEPALIVE, slot, mInterval, mPacket); |
| break; |
| case TYPE_TCP: |
| try { |
| mTcpController.startSocketMonitor(mFd, this, mSlot); |
| } catch (InvalidSocketException e) { |
| handleStopKeepalive(mNai, mSlot, ERROR_INVALID_SOCKET); |
| return; |
| } |
| mNai.asyncChannel |
| .sendMessage(CMD_ADD_KEEPALIVE_PACKET_FILTER, slot, 0 /* Unused */, |
| mPacket); |
| // TODO: check result from apf and notify of failure as needed. |
| mNai.asyncChannel |
| .sendMessage(CMD_START_SOCKET_KEEPALIVE, slot, mInterval, mPacket); |
| break; |
| default: |
| Log.wtf(TAG, "Starting keepalive with unknown type: " + mType); |
| handleStopKeepalive(mNai, mSlot, error); |
| return; |
| } |
| mStartedState = STARTING; |
| } else { |
| handleStopKeepalive(mNai, mSlot, error); |
| return; |
| } |
| } |
| |
| void stop(int reason) { |
| int uid = Binder.getCallingUid(); |
| if (uid != mUid && uid != Process.SYSTEM_UID) { |
| if (DBG) { |
| Log.e(TAG, "Cannot stop unowned keepalive " + mSlot + " on " + mNai.network); |
| } |
| } |
| if (NOT_STARTED != mStartedState) { |
| Log.d(TAG, "Stopping keepalive " + mSlot + " on " + mNai.name()); |
| if (mType == TYPE_NATT) { |
| mNai.asyncChannel.sendMessage(CMD_STOP_SOCKET_KEEPALIVE, mSlot); |
| } else if (mType == TYPE_TCP) { |
| mNai.asyncChannel.sendMessage(CMD_STOP_SOCKET_KEEPALIVE, mSlot); |
| mNai.asyncChannel.sendMessage(CMD_REMOVE_KEEPALIVE_PACKET_FILTER, mSlot); |
| mTcpController.stopSocketMonitor(mSlot); |
| } else { |
| Log.wtf(TAG, "Stopping keepalive with unknown type: " + mType); |
| } |
| } |
| |
| if (reason == SUCCESS) { |
| try { |
| mCallback.onStopped(); |
| } catch (RemoteException e) { |
| Log.w(TAG, "Discarded onStop callback: " + reason); |
| } |
| } else if (reason == DATA_RECEIVED) { |
| try { |
| mCallback.onDataReceived(); |
| } catch (RemoteException e) { |
| Log.w(TAG, "Discarded onDataReceived callback: " + reason); |
| } |
| } else { |
| notifyErrorCallback(mCallback, reason); |
| } |
| |
| unlinkDeathRecipient(); |
| } |
| |
| void onFileDescriptorInitiatedStop(final int socketKeepaliveReason) { |
| handleStopKeepalive(mNai, mSlot, socketKeepaliveReason); |
| } |
| } |
| |
| void notifyErrorCallback(ISocketKeepaliveCallback cb, int error) { |
| if (DBG) Log.w(TAG, "Sending onError(" + error + ") callback"); |
| try { |
| cb.onError(error); |
| } catch (RemoteException e) { |
| Log.w(TAG, "Discarded onError(" + error + ") callback"); |
| } |
| } |
| |
| private int findFirstFreeSlot(NetworkAgentInfo nai) { |
| HashMap networkKeepalives = mKeepalives.get(nai); |
| if (networkKeepalives == null) { |
| networkKeepalives = new HashMap<Integer, KeepaliveInfo>(); |
| mKeepalives.put(nai, networkKeepalives); |
| } |
| |
| // Find the lowest-numbered free slot. Slot numbers start from 1, because that's what two |
| // separate chipset implementations independently came up with. |
| int slot; |
| for (slot = 1; slot <= networkKeepalives.size(); slot++) { |
| if (networkKeepalives.get(slot) == null) { |
| return slot; |
| } |
| } |
| return slot; |
| } |
| |
| public void handleStartKeepalive(Message message) { |
| KeepaliveInfo ki = (KeepaliveInfo) message.obj; |
| NetworkAgentInfo nai = ki.getNai(); |
| int slot = findFirstFreeSlot(nai); |
| mKeepalives.get(nai).put(slot, ki); |
| ki.start(slot); |
| } |
| |
| public void handleStopAllKeepalives(NetworkAgentInfo nai, int reason) { |
| HashMap <Integer, KeepaliveInfo> networkKeepalives = mKeepalives.get(nai); |
| if (networkKeepalives != null) { |
| for (KeepaliveInfo ki : networkKeepalives.values()) { |
| ki.stop(reason); |
| } |
| networkKeepalives.clear(); |
| mKeepalives.remove(nai); |
| } |
| } |
| |
| public void handleStopKeepalive(NetworkAgentInfo nai, int slot, int reason) { |
| String networkName = (nai == null) ? "(null)" : nai.name(); |
| HashMap <Integer, KeepaliveInfo> networkKeepalives = mKeepalives.get(nai); |
| if (networkKeepalives == null) { |
| Log.e(TAG, "Attempt to stop keepalive on nonexistent network " + networkName); |
| return; |
| } |
| KeepaliveInfo ki = networkKeepalives.get(slot); |
| if (ki == null) { |
| Log.e(TAG, "Attempt to stop nonexistent keepalive " + slot + " on " + networkName); |
| return; |
| } |
| ki.stop(reason); |
| Log.d(TAG, "Stopped keepalive " + slot + " on " + networkName); |
| networkKeepalives.remove(slot); |
| if (networkKeepalives.isEmpty()) { |
| mKeepalives.remove(nai); |
| } |
| } |
| |
| public void handleCheckKeepalivesStillValid(NetworkAgentInfo nai) { |
| HashMap <Integer, KeepaliveInfo> networkKeepalives = mKeepalives.get(nai); |
| if (networkKeepalives != null) { |
| ArrayList<Pair<Integer, Integer>> invalidKeepalives = new ArrayList<>(); |
| for (int slot : networkKeepalives.keySet()) { |
| int error = networkKeepalives.get(slot).isValid(); |
| if (error != SUCCESS) { |
| invalidKeepalives.add(Pair.create(slot, error)); |
| } |
| } |
| for (Pair<Integer, Integer> slotAndError: invalidKeepalives) { |
| handleStopKeepalive(nai, slotAndError.first, slotAndError.second); |
| } |
| } |
| } |
| |
| /** Handle keepalive events from lower layer. */ |
| public void handleEventSocketKeepalive(@NonNull NetworkAgentInfo nai, |
| @NonNull Message message) { |
| int slot = message.arg1; |
| int reason = message.arg2; |
| |
| KeepaliveInfo ki = null; |
| try { |
| ki = mKeepalives.get(nai).get(slot); |
| } catch(NullPointerException e) {} |
| if (ki == null) { |
| Log.e(TAG, "Event for unknown keepalive " + slot + " on " + nai.name()); |
| return; |
| } |
| |
| // This can be called in a number of situations : |
| // - startedState is STARTING. |
| // - reason is SUCCESS => go to STARTED. |
| // - reason isn't SUCCESS => it's an error starting. Go to NOT_STARTED and stop keepalive. |
| // - startedState is STARTED. |
| // - reason is SUCCESS => it's a success stopping. Go to NOT_STARTED and stop keepalive. |
| // - reason isn't SUCCESS => it's an error in exec. Go to NOT_STARTED and stop keepalive. |
| // The control is not supposed to ever come here if the state is NOT_STARTED. This is |
| // because in NOT_STARTED state, the code will switch to STARTING before sending messages |
| // to start, and the only way to NOT_STARTED is this function, through the edges outlined |
| // above : in all cases, keepalive gets stopped and can't restart without going into |
| // STARTING as messages are ordered. This also depends on the hardware processing the |
| // messages in order. |
| // TODO : clarify this code and get rid of mStartedState. Using a StateMachine is an |
| // option. |
| if (reason == SUCCESS && KeepaliveInfo.STARTING == ki.mStartedState) { |
| // Keepalive successfully started. |
| if (DBG) Log.d(TAG, "Started keepalive " + slot + " on " + nai.name()); |
| ki.mStartedState = KeepaliveInfo.STARTED; |
| try { |
| ki.mCallback.onStarted(slot); |
| } catch (RemoteException e) { |
| Log.w(TAG, "Discarded onStarted(" + slot + ") callback"); |
| } |
| } else { |
| // Keepalive successfully stopped, or error. |
| ki.mStartedState = KeepaliveInfo.NOT_STARTED; |
| if (reason == SUCCESS) { |
| // The message indicated success stopping : don't call handleStopKeepalive. |
| if (DBG) Log.d(TAG, "Successfully stopped keepalive " + slot + " on " + nai.name()); |
| } else { |
| // The message indicated some error trying to start or during the course of |
| // keepalive : do call handleStopKeepalive. |
| handleStopKeepalive(nai, slot, reason); |
| if (DBG) Log.d(TAG, "Keepalive " + slot + " on " + nai.name() + " error " + reason); |
| } |
| } |
| } |
| |
| /** |
| * Called when requesting that keepalives be started on a IPsec NAT-T socket. See |
| * {@link android.net.SocketKeepalive}. |
| **/ |
| public void startNattKeepalive(@Nullable NetworkAgentInfo nai, |
| int intervalSeconds, |
| @NonNull ISocketKeepaliveCallback cb, |
| @NonNull String srcAddrString, |
| int srcPort, |
| @NonNull String dstAddrString, |
| int dstPort) { |
| if (nai == null) { |
| notifyErrorCallback(cb, ERROR_INVALID_NETWORK); |
| return; |
| } |
| |
| InetAddress srcAddress, dstAddress; |
| try { |
| srcAddress = NetworkUtils.numericToInetAddress(srcAddrString); |
| dstAddress = NetworkUtils.numericToInetAddress(dstAddrString); |
| } catch (IllegalArgumentException e) { |
| notifyErrorCallback(cb, ERROR_INVALID_IP_ADDRESS); |
| return; |
| } |
| |
| KeepalivePacketData packet; |
| try { |
| packet = NattKeepalivePacketData.nattKeepalivePacket( |
| srcAddress, srcPort, dstAddress, NATT_PORT); |
| } catch (InvalidPacketException e) { |
| notifyErrorCallback(cb, e.error); |
| return; |
| } |
| KeepaliveInfo ki = new KeepaliveInfo(cb, nai, packet, intervalSeconds, |
| KeepaliveInfo.TYPE_NATT, null); |
| Log.d(TAG, "Created keepalive: " + ki.toString()); |
| mConnectivityServiceHandler.obtainMessage( |
| NetworkAgent.CMD_START_SOCKET_KEEPALIVE, ki).sendToTarget(); |
| } |
| |
| /** |
| * Called by ConnectivityService to start TCP keepalive on a file descriptor. |
| * |
| * In order to offload keepalive for application correctly, sequence number, ack number and |
| * other fields are needed to form the keepalive packet. Thus, this function synchronously |
| * puts the socket into repair mode to get the necessary information. After the socket has been |
| * put into repair mode, the application cannot access the socket until reverted to normal. |
| * |
| * See {@link android.net.SocketKeepalive}. |
| **/ |
| public void startTcpKeepalive(@Nullable NetworkAgentInfo nai, |
| @NonNull FileDescriptor fd, |
| int intervalSeconds, |
| @NonNull ISocketKeepaliveCallback cb) { |
| if (nai == null) { |
| notifyErrorCallback(cb, ERROR_INVALID_NETWORK); |
| return; |
| } |
| |
| TcpKeepalivePacketData packet = null; |
| try { |
| TcpSocketInfo tsi = TcpKeepaliveController.switchToRepairMode(fd); |
| packet = TcpKeepalivePacketData.tcpKeepalivePacket(tsi); |
| } catch (InvalidPacketException | InvalidSocketException e) { |
| try { |
| TcpKeepaliveController.switchOutOfRepairMode(fd); |
| } catch (ErrnoException e1) { |
| Log.e(TAG, "Couldn't move fd out of repair mode after failure to start keepalive"); |
| } |
| notifyErrorCallback(cb, e.error); |
| return; |
| } |
| KeepaliveInfo ki = new KeepaliveInfo(cb, nai, packet, intervalSeconds, |
| KeepaliveInfo.TYPE_TCP, fd); |
| Log.d(TAG, "Created keepalive: " + ki.toString()); |
| mConnectivityServiceHandler.obtainMessage(CMD_START_SOCKET_KEEPALIVE, ki).sendToTarget(); |
| } |
| |
| /** |
| * Called when requesting that keepalives be started on a IPsec NAT-T socket. This function is |
| * identical to {@link #startNattKeepalive}, but also takes a {@code resourceId}, which is the |
| * resource index bound to the {@link UdpEncapsulationSocket} when creating by |
| * {@link com.android.server.IpSecService} to verify whether the given |
| * {@link UdpEncapsulationSocket} is legitimate. |
| **/ |
| public void startNattKeepalive(@Nullable NetworkAgentInfo nai, |
| @Nullable FileDescriptor fd, |
| int resourceId, |
| int intervalSeconds, |
| @NonNull ISocketKeepaliveCallback cb, |
| @NonNull String srcAddrString, |
| @NonNull String dstAddrString, |
| int dstPort) { |
| // Ensure that the socket is created by IpSecService. |
| if (!isNattKeepaliveSocketValid(fd, resourceId)) { |
| notifyErrorCallback(cb, ERROR_INVALID_SOCKET); |
| } |
| |
| // Get src port to adopt old API. |
| int srcPort = 0; |
| try { |
| final SocketAddress srcSockAddr = Os.getsockname(fd); |
| srcPort = ((InetSocketAddress) srcSockAddr).getPort(); |
| } catch (ErrnoException e) { |
| notifyErrorCallback(cb, ERROR_INVALID_SOCKET); |
| } |
| |
| // Forward request to old API. |
| startNattKeepalive(nai, intervalSeconds, cb, srcAddrString, srcPort, |
| dstAddrString, dstPort); |
| } |
| |
| /** |
| * Verify if the IPsec NAT-T file descriptor and resource Id hold for IPsec keepalive is valid. |
| **/ |
| public static boolean isNattKeepaliveSocketValid(@Nullable FileDescriptor fd, int resourceId) { |
| // TODO: 1. confirm whether the fd is called from system api or created by IpSecService. |
| // 2. If the fd is created from the system api, check that it's bounded. And |
| // call dup to keep the fd open. |
| // 3. If the fd is created from IpSecService, check if the resource ID is valid. And |
| // hold the resource needed in IpSecService. |
| if (null == fd) { |
| return false; |
| } |
| return true; |
| } |
| |
| public void dump(IndentingPrintWriter pw) { |
| pw.println("Socket keepalives:"); |
| pw.increaseIndent(); |
| for (NetworkAgentInfo nai : mKeepalives.keySet()) { |
| pw.println(nai.name()); |
| pw.increaseIndent(); |
| for (int slot : mKeepalives.get(nai).keySet()) { |
| KeepaliveInfo ki = mKeepalives.get(nai).get(slot); |
| pw.println(slot + ": " + ki.toString()); |
| } |
| pw.decreaseIndent(); |
| } |
| pw.decreaseIndent(); |
| } |
| } |
