fa37b2f613
[ IPv6TetheringCoordinator ]
- Send CMD_IPV6_TETHER_UPDATE to all TetherInterfaceStateMachines.
This results in some spurious noop messages, but currently
the coordinator does not maintain state about which downstream interaces
are serving IPv6 and which are not. Until it does maintain such state
it does not know to notify only the affected interfaces about a loss of
IPv6 upstream
[ IPv6TetheringInterfaceServices ]
- De-dup incoming IPv6-only LinkProperties to avoid spurious updates
to the RA daemon.
- Keep track of new prefixes/dns and newly deprecated prefixes/dns
on each update.
- Set and remove local_network routes based on new and newly
deprecated prefixes.
- Set and remove local DNS server IP addresses based on new
and newly deprecated DNS servers. Update dnsmasq via netd
accordingly.
- Pass newly deprecated and new information to the RA daemon.
[ RouterAdvertisementDaemon ]
- Receive newly deprecated prefixes/DNS and update local tracking
data structures accordingly.
- Properly send urgent final deprecation RAs, and then cease all
transmissions.
Bug: 30298058
Change-Id: Idc821603fa93bff1a821d1180d4135bc70e4a08d
717 lines
27 KiB
Java
717 lines
27 KiB
Java
/*
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* Copyright (C) 2016 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package android.net.ip;
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import static android.system.OsConstants.*;
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import android.net.IpPrefix;
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import android.net.LinkAddress;
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import android.net.LinkProperties;
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import android.net.NetworkUtils;
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import android.system.ErrnoException;
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import android.system.Os;
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import android.system.StructGroupReq;
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import android.system.StructTimeval;
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import android.util.Log;
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import com.android.internal.annotations.GuardedBy;
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import libcore.io.IoBridge;
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import libcore.util.HexEncoding;
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import java.io.FileDescriptor;
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import java.io.InterruptedIOException;
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import java.io.IOException;
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import java.net.Inet6Address;
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import java.net.InetAddress;
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import java.net.InetSocketAddress;
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import java.net.SocketException;
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import java.net.UnknownHostException;
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import java.nio.BufferOverflowException;
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import java.nio.ByteBuffer;
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import java.nio.ByteOrder;
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import java.util.ArrayList;
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import java.util.HashMap;
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import java.util.HashSet;
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import java.util.Iterator;
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import java.util.Map;
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import java.util.Random;
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import java.util.Set;
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import java.util.concurrent.atomic.AtomicInteger;
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/**
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* Basic IPv6 Router Advertisement Daemon.
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*
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* TODO:
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*
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* - Rewrite using Handler (and friends) so that AlarmManager can deliver
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* "kick" messages when it's time to send a multicast RA.
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*
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* @hide
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*/
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public class RouterAdvertisementDaemon {
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private static final String TAG = RouterAdvertisementDaemon.class.getSimpleName();
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private static final byte ICMPV6_ND_ROUTER_SOLICIT = asByte(133);
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private static final byte ICMPV6_ND_ROUTER_ADVERT = asByte(134);
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private static final int IPV6_MIN_MTU = 1280;
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private static final int MIN_RA_HEADER_SIZE = 16;
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// Summary of various timers and lifetimes.
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private static final int MIN_RTR_ADV_INTERVAL_SEC = 300;
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private static final int MAX_RTR_ADV_INTERVAL_SEC = 600;
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// In general, router, prefix, and DNS lifetimes are all advised to be
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// greater than or equal to 3 * MAX_RTR_ADV_INTERVAL. Here, we double
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// that to allow for multicast packet loss.
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//
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// This MAX_RTR_ADV_INTERVAL_SEC and DEFAULT_LIFETIME are also consistent
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// with the https://tools.ietf.org/html/rfc7772#section-4 discussion of
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// "approximately 7 RAs per hour".
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private static final int DEFAULT_LIFETIME = 6 * MAX_RTR_ADV_INTERVAL_SEC;
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// From https://tools.ietf.org/html/rfc4861#section-10 .
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private static final int MIN_DELAY_BETWEEN_RAS_SEC = 3;
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// Both initial and final RAs, but also for changes in RA contents.
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// From https://tools.ietf.org/html/rfc4861#section-10 .
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private static final int MAX_URGENT_RTR_ADVERTISEMENTS = 5;
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private static final int DAY_IN_SECONDS = 86_400;
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private static final byte[] ALL_NODES = new byte[] {
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(byte) 0xff, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
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};
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private final String mIfName;
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private final int mIfIndex;
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private final byte[] mHwAddr;
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private final InetSocketAddress mAllNodes;
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// This lock is to protect the RA from being updated while being
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// transmitted on another thread (multicast or unicast).
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//
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// TODO: This should be handled with a more RCU-like approach.
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private final Object mLock = new Object();
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@GuardedBy("mLock")
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private final byte[] mRA = new byte[IPV6_MIN_MTU];
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@GuardedBy("mLock")
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private int mRaLength;
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@GuardedBy("mLock")
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private final DeprecatedInfoTracker mDeprecatedInfoTracker;
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@GuardedBy("mLock")
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private RaParams mRaParams;
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private volatile FileDescriptor mSocket;
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private volatile MulticastTransmitter mMulticastTransmitter;
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private volatile UnicastResponder mUnicastResponder;
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public static class RaParams {
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public boolean hasDefaultRoute;
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public int mtu;
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public HashSet<IpPrefix> prefixes;
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public HashSet<Inet6Address> dnses;
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public RaParams() {
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hasDefaultRoute = false;
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mtu = IPV6_MIN_MTU;
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prefixes = new HashSet<IpPrefix>();
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dnses = new HashSet<Inet6Address>();
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}
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public RaParams(RaParams other) {
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hasDefaultRoute = other.hasDefaultRoute;
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mtu = other.mtu;
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prefixes = (HashSet) other.prefixes.clone();
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dnses = (HashSet) other.dnses.clone();
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}
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// Returns the subset of RA parameters that become deprecated when
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// moving from announcing oldRa to announcing newRa.
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//
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// Currently only tracks differences in |prefixes| and |dnses|.
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public static RaParams getDeprecatedRaParams(RaParams oldRa, RaParams newRa) {
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RaParams newlyDeprecated = new RaParams();
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if (oldRa != null) {
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for (IpPrefix ipp : oldRa.prefixes) {
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if (newRa == null || !newRa.prefixes.contains(ipp)) {
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newlyDeprecated.prefixes.add(ipp);
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}
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}
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for (Inet6Address dns : oldRa.dnses) {
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if (newRa == null || !newRa.dnses.contains(dns)) {
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newlyDeprecated.dnses.add(dns);
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}
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}
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}
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return newlyDeprecated;
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}
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}
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private static class DeprecatedInfoTracker {
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private final HashMap<IpPrefix, Integer> mPrefixes = new HashMap<>();
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private final HashMap<Inet6Address, Integer> mDnses = new HashMap<>();
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Set<IpPrefix> getPrefixes() { return mPrefixes.keySet(); }
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void putPrefixes(Set<IpPrefix> prefixes) {
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for (IpPrefix ipp : prefixes) {
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mPrefixes.put(ipp, MAX_URGENT_RTR_ADVERTISEMENTS);
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}
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}
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void removePrefixes(Set<IpPrefix> prefixes) {
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for (IpPrefix ipp : prefixes) {
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mPrefixes.remove(ipp);
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}
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}
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Set<Inet6Address> getDnses() { return mDnses.keySet(); }
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void putDnses(Set<Inet6Address> dnses) {
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for (Inet6Address dns : dnses) {
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mDnses.put(dns, MAX_URGENT_RTR_ADVERTISEMENTS);
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}
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}
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void removeDnses(Set<Inet6Address> dnses) {
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for (Inet6Address dns : dnses) {
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mDnses.remove(dns);
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}
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}
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boolean isEmpty() { return mPrefixes.isEmpty() && mDnses.isEmpty(); }
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private boolean decrementCounters() {
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boolean removed = decrementCounter(mPrefixes);
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removed |= decrementCounter(mDnses);
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return removed;
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}
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private <T> boolean decrementCounter(HashMap<T, Integer> map) {
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boolean removed = false;
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for (Iterator<Map.Entry<T, Integer>> it = map.entrySet().iterator();
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it.hasNext();) {
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Map.Entry<T, Integer> kv = it.next();
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if (kv.getValue() == 0) {
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it.remove();
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removed = true;
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} else {
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kv.setValue(kv.getValue() - 1);
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}
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}
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return removed;
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}
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}
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public RouterAdvertisementDaemon(String ifname, int ifindex, byte[] hwaddr) {
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mIfName = ifname;
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mIfIndex = ifindex;
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mHwAddr = hwaddr;
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mAllNodes = new InetSocketAddress(getAllNodesForScopeId(mIfIndex), 0);
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mDeprecatedInfoTracker = new DeprecatedInfoTracker();
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}
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public void buildNewRa(RaParams deprecatedParams, RaParams newParams) {
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synchronized (mLock) {
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if (deprecatedParams != null) {
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mDeprecatedInfoTracker.putPrefixes(deprecatedParams.prefixes);
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mDeprecatedInfoTracker.putDnses(deprecatedParams.dnses);
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}
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if (newParams != null) {
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// Process information that is no longer deprecated.
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mDeprecatedInfoTracker.removePrefixes(newParams.prefixes);
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mDeprecatedInfoTracker.removeDnses(newParams.dnses);
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}
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mRaParams = newParams;
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assembleRaLocked();
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}
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maybeNotifyMulticastTransmitter();
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}
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public boolean start() {
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if (!createSocket()) {
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return false;
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}
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mMulticastTransmitter = new MulticastTransmitter();
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mMulticastTransmitter.start();
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mUnicastResponder = new UnicastResponder();
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mUnicastResponder.start();
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return true;
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}
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public void stop() {
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closeSocket();
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mMulticastTransmitter = null;
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mUnicastResponder = null;
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}
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private void assembleRaLocked() {
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final ByteBuffer ra = ByteBuffer.wrap(mRA);
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ra.order(ByteOrder.BIG_ENDIAN);
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boolean shouldSendRA = false;
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try {
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putHeader(ra, mRaParams != null && mRaParams.hasDefaultRoute);
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putSlla(ra, mHwAddr);
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mRaLength = ra.position();
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// https://tools.ietf.org/html/rfc5175#section-4 says:
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//
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// "MUST NOT be added to a Router Advertisement message
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// if no flags in the option are set."
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//
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// putExpandedFlagsOption(ra);
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if (mRaParams != null) {
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putMtu(ra, mRaParams.mtu);
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mRaLength = ra.position();
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for (IpPrefix ipp : mRaParams.prefixes) {
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putPio(ra, ipp, DEFAULT_LIFETIME, DEFAULT_LIFETIME);
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mRaLength = ra.position();
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shouldSendRA = true;
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}
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if (mRaParams.dnses.size() > 0) {
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putRdnss(ra, mRaParams.dnses, DEFAULT_LIFETIME);
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mRaLength = ra.position();
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shouldSendRA = true;
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}
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}
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for (IpPrefix ipp : mDeprecatedInfoTracker.getPrefixes()) {
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putPio(ra, ipp, 0, 0);
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mRaLength = ra.position();
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shouldSendRA = true;
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}
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final Set<Inet6Address> deprecatedDnses = mDeprecatedInfoTracker.getDnses();
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if (!deprecatedDnses.isEmpty()) {
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putRdnss(ra, deprecatedDnses, 0);
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mRaLength = ra.position();
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shouldSendRA = true;
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}
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} catch (BufferOverflowException e) {
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// The packet up to mRaLength is valid, since it has been updated
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// progressively as the RA was built. Log an error, and continue
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// on as best as possible.
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Log.e(TAG, "Could not construct new RA: " + e);
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}
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// We have nothing worth announcing; indicate as much to maybeSendRA().
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if (!shouldSendRA) {
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mRaLength = 0;
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}
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}
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private void maybeNotifyMulticastTransmitter() {
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final MulticastTransmitter m = mMulticastTransmitter;
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if (m != null) {
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m.hup();
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}
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}
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private static Inet6Address getAllNodesForScopeId(int scopeId) {
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try {
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return Inet6Address.getByAddress("ff02::1", ALL_NODES, scopeId);
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} catch (UnknownHostException uhe) {
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Log.wtf(TAG, "Failed to construct ff02::1 InetAddress: " + uhe);
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return null;
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}
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}
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private static byte asByte(int value) { return (byte) value; }
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private static short asShort(int value) { return (short) value; }
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private static void putHeader(ByteBuffer ra, boolean hasDefaultRoute) {
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/**
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Router Advertisement Message Format
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0 1 2 3
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0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Type | Code | Checksum |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Cur Hop Limit |M|O|H|Prf|P|R|R| Router Lifetime |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Reachable Time |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Retrans Timer |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Options ...
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+-+-+-+-+-+-+-+-+-+-+-+-
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*/
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final byte DEFAULT_HOPLIMIT = 64;
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ra.put(ICMPV6_ND_ROUTER_ADVERT)
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.put(asByte(0))
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.putShort(asShort(0))
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.put(DEFAULT_HOPLIMIT)
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// RFC 4191 "high" preference, iff. advertising a default route.
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.put(hasDefaultRoute ? asByte(0x08) : asByte(0))
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.putShort(hasDefaultRoute ? asShort(DEFAULT_LIFETIME) : asShort(0))
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.putInt(0)
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.putInt(0);
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}
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private static void putSlla(ByteBuffer ra, byte[] slla) {
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/**
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Source/Target Link-layer Address
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0 1 2 3
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0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Type | Length | Link-Layer Address ...
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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*/
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if (slla == null || slla.length != 6) {
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// Only IEEE 802.3 6-byte addresses are supported.
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return;
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}
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final byte ND_OPTION_SLLA = 1;
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final byte SLLA_NUM_8OCTETS = 1;
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ra.put(ND_OPTION_SLLA)
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.put(SLLA_NUM_8OCTETS)
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.put(slla);
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}
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private static void putExpandedFlagsOption(ByteBuffer ra) {
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/**
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Router Advertisement Expanded Flags Option
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0 1 2 3
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0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Type | Length | Bit fields available ..
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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... for assignment |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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*/
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final byte ND_OPTION_EFO = 26;
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final byte EFO_NUM_8OCTETS = 1;
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ra.put(ND_OPTION_EFO)
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.put(EFO_NUM_8OCTETS)
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.putShort(asShort(0))
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.putInt(0);
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}
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private static void putMtu(ByteBuffer ra, int mtu) {
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/**
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MTU
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0 1 2 3
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0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Type | Length | Reserved |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| MTU |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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*/
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final byte ND_OPTION_MTU = 5;
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final byte MTU_NUM_8OCTETS = 1;
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ra.put(ND_OPTION_MTU)
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.put(MTU_NUM_8OCTETS)
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.putShort(asShort(0))
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.putInt((mtu < IPV6_MIN_MTU) ? IPV6_MIN_MTU : mtu);
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}
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private static void putPio(ByteBuffer ra, IpPrefix ipp,
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int validTime, int preferredTime) {
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/**
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Prefix Information
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0 1 2 3
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0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Type | Length | Prefix Length |L|A| Reserved1 |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Valid Lifetime |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Preferred Lifetime |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Reserved2 |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| |
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+ +
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| |
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+ Prefix +
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+ +
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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*/
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final int prefixLength = ipp.getPrefixLength();
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if (prefixLength != 64) {
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return;
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}
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final byte ND_OPTION_PIO = 3;
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final byte PIO_NUM_8OCTETS = 4;
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if (validTime < 0) validTime = 0;
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if (preferredTime < 0) preferredTime = 0;
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if (preferredTime > validTime) preferredTime = validTime;
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final byte[] addr = ipp.getAddress().getAddress();
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ra.put(ND_OPTION_PIO)
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.put(PIO_NUM_8OCTETS)
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.put(asByte(prefixLength))
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.put(asByte(0xc0)) /* L & A set */
|
|
.putInt(validTime)
|
|
.putInt(preferredTime)
|
|
.putInt(0)
|
|
.put(addr);
|
|
}
|
|
|
|
private static void putRio(ByteBuffer ra, IpPrefix ipp) {
|
|
/**
|
|
Route Information Option
|
|
|
|
0 1 2 3
|
|
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
| Type | Length | Prefix Length |Resvd|Prf|Resvd|
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
| Route Lifetime |
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
| Prefix (Variable Length) |
|
|
. .
|
|
. .
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
*/
|
|
final int prefixLength = ipp.getPrefixLength();
|
|
if (prefixLength > 64) {
|
|
return;
|
|
}
|
|
final byte ND_OPTION_RIO = 24;
|
|
final byte RIO_NUM_8OCTETS = asByte(
|
|
(prefixLength == 0) ? 1 : (prefixLength <= 8) ? 2 : 3);
|
|
|
|
final byte[] addr = ipp.getAddress().getAddress();
|
|
ra.put(ND_OPTION_RIO)
|
|
.put(RIO_NUM_8OCTETS)
|
|
.put(asByte(prefixLength))
|
|
.put(asByte(0x18))
|
|
.putInt(DEFAULT_LIFETIME);
|
|
|
|
// Rely upon an IpPrefix's address being properly zeroed.
|
|
if (prefixLength > 0) {
|
|
ra.put(addr, 0, (prefixLength <= 64) ? 8 : 16);
|
|
}
|
|
}
|
|
|
|
private static void putRdnss(ByteBuffer ra, Set<Inet6Address> dnses, int lifetime) {
|
|
/**
|
|
Recursive DNS Server (RDNSS) Option
|
|
|
|
0 1 2 3
|
|
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
| Type | Length | Reserved |
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
| Lifetime |
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
| |
|
|
: Addresses of IPv6 Recursive DNS Servers :
|
|
| |
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
*/
|
|
|
|
final byte ND_OPTION_RDNSS = 25;
|
|
final byte RDNSS_NUM_8OCTETS = asByte(dnses.size() * 2 + 1);
|
|
ra.put(ND_OPTION_RDNSS)
|
|
.put(RDNSS_NUM_8OCTETS)
|
|
.putShort(asShort(0))
|
|
.putInt(lifetime);
|
|
|
|
for (Inet6Address dns : dnses) {
|
|
// NOTE: If the full of list DNS servers doesn't fit in the packet,
|
|
// this code will cause a buffer overflow and the RA won't include
|
|
// include this instance of the option at all.
|
|
//
|
|
// TODO: Consider looking at ra.remaining() to determine how many
|
|
// DNS servers will fit, and adding only those.
|
|
ra.put(dns.getAddress());
|
|
}
|
|
}
|
|
|
|
private boolean createSocket() {
|
|
final int SEND_TIMEOUT_MS = 300;
|
|
|
|
try {
|
|
mSocket = Os.socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6);
|
|
// Setting SNDTIMEO is purely for defensive purposes.
|
|
Os.setsockoptTimeval(
|
|
mSocket, SOL_SOCKET, SO_SNDTIMEO, StructTimeval.fromMillis(SEND_TIMEOUT_MS));
|
|
Os.setsockoptIfreq(mSocket, SOL_SOCKET, SO_BINDTODEVICE, mIfName);
|
|
NetworkUtils.protectFromVpn(mSocket);
|
|
NetworkUtils.setupRaSocket(mSocket, mIfIndex);
|
|
} catch (ErrnoException | IOException e) {
|
|
Log.e(TAG, "Failed to create RA daemon socket: " + e);
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
private void closeSocket() {
|
|
if (mSocket != null) {
|
|
try {
|
|
IoBridge.closeAndSignalBlockedThreads(mSocket);
|
|
} catch (IOException ignored) {}
|
|
}
|
|
mSocket = null;
|
|
}
|
|
|
|
private boolean isSocketValid() {
|
|
final FileDescriptor s = mSocket;
|
|
return (s != null) && s.valid();
|
|
}
|
|
|
|
private boolean isSuitableDestination(InetSocketAddress dest) {
|
|
if (mAllNodes.equals(dest)) {
|
|
return true;
|
|
}
|
|
|
|
final InetAddress destip = dest.getAddress();
|
|
return (destip instanceof Inet6Address) &&
|
|
destip.isLinkLocalAddress() &&
|
|
(((Inet6Address) destip).getScopeId() == mIfIndex);
|
|
}
|
|
|
|
private void maybeSendRA(InetSocketAddress dest) {
|
|
if (dest == null || !isSuitableDestination(dest)) {
|
|
dest = mAllNodes;
|
|
}
|
|
|
|
try {
|
|
synchronized (mLock) {
|
|
if (mRaLength < MIN_RA_HEADER_SIZE) {
|
|
// No actual RA to send.
|
|
return;
|
|
}
|
|
Os.sendto(mSocket, mRA, 0, mRaLength, 0, dest);
|
|
}
|
|
Log.d(TAG, "RA sendto " + dest.getAddress().getHostAddress());
|
|
} catch (ErrnoException | SocketException e) {
|
|
if (isSocketValid()) {
|
|
Log.e(TAG, "sendto error: " + e);
|
|
}
|
|
}
|
|
}
|
|
|
|
private final class UnicastResponder extends Thread {
|
|
private final InetSocketAddress solicitor = new InetSocketAddress();
|
|
// The recycled buffer for receiving Router Solicitations from clients.
|
|
// If the RS is larger than IPV6_MIN_MTU the packets are truncated.
|
|
// This is fine since currently only byte 0 is examined anyway.
|
|
private final byte mSolication[] = new byte[IPV6_MIN_MTU];
|
|
|
|
@Override
|
|
public void run() {
|
|
while (isSocketValid()) {
|
|
try {
|
|
// Blocking receive.
|
|
final int rval = Os.recvfrom(
|
|
mSocket, mSolication, 0, mSolication.length, 0, solicitor);
|
|
// Do the least possible amount of validation.
|
|
if (rval < 1 || mSolication[0] != ICMPV6_ND_ROUTER_SOLICIT) {
|
|
continue;
|
|
}
|
|
} catch (ErrnoException | SocketException e) {
|
|
if (isSocketValid()) {
|
|
Log.e(TAG, "recvfrom error: " + e);
|
|
}
|
|
continue;
|
|
}
|
|
|
|
maybeSendRA(solicitor);
|
|
}
|
|
}
|
|
}
|
|
|
|
// TODO: Consider moving this to run on a provided Looper as a Handler,
|
|
// with WakeupMessage-style messages providing the timer driven input.
|
|
private final class MulticastTransmitter extends Thread {
|
|
private final Random mRandom = new Random();
|
|
private final AtomicInteger mUrgentAnnouncements = new AtomicInteger(0);
|
|
|
|
@Override
|
|
public void run() {
|
|
while (isSocketValid()) {
|
|
try {
|
|
Thread.sleep(getNextMulticastTransmitDelayMs());
|
|
} catch (InterruptedException ignored) {
|
|
// Stop sleeping, immediately send an RA, and continue.
|
|
}
|
|
|
|
maybeSendRA(mAllNodes);
|
|
synchronized (mLock) {
|
|
if (mDeprecatedInfoTracker.decrementCounters()) {
|
|
// At least one deprecated PIO has been removed;
|
|
// reassemble the RA.
|
|
assembleRaLocked();
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
public void hup() {
|
|
// Set to one fewer that the desired number, because as soon as
|
|
// the thread interrupt is processed we immediately send an RA
|
|
// and mUrgentAnnouncements is not examined until the subsequent
|
|
// sleep interval computation (i.e. this way we send 3 and not 4).
|
|
mUrgentAnnouncements.set(MAX_URGENT_RTR_ADVERTISEMENTS - 1);
|
|
interrupt();
|
|
}
|
|
|
|
private int getNextMulticastTransmitDelaySec() {
|
|
boolean deprecationInProgress = false;
|
|
synchronized (mLock) {
|
|
if (mRaLength < MIN_RA_HEADER_SIZE) {
|
|
// No actual RA to send; just sleep for 1 day.
|
|
return DAY_IN_SECONDS;
|
|
}
|
|
deprecationInProgress = !mDeprecatedInfoTracker.isEmpty();
|
|
}
|
|
|
|
final int urgentPending = mUrgentAnnouncements.getAndDecrement();
|
|
if ((urgentPending > 0) || deprecationInProgress) {
|
|
return MIN_DELAY_BETWEEN_RAS_SEC;
|
|
}
|
|
|
|
return MIN_RTR_ADV_INTERVAL_SEC + mRandom.nextInt(
|
|
MAX_RTR_ADV_INTERVAL_SEC - MIN_RTR_ADV_INTERVAL_SEC);
|
|
}
|
|
|
|
private long getNextMulticastTransmitDelayMs() {
|
|
return 1000 * (long) getNextMulticastTransmitDelaySec();
|
|
}
|
|
}
|
|
}
|